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  • 1167801.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Alecrim, Viviane
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Forsberg, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Thermally reduced kaolin-graphene oxide nanocomposites for gas sensing2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, p. Art. no. 7676-Article in journal (Refereed)
    Abstract [en]

    Highly sensitive graphene-based gas sensors can be made using large-area single layer graphene, but the cost of large-area pure graphene is high, making the simpler reduced graphene oxide (rGO) an attractive alternative. To use rGO for gas sensing, however, require a high active surface area and slightly different approach is needed. Here, we report on a simple method to produce kaolin-graphene oxide (GO) nanocomposites and an application of this nanocomposite as a gas sensor. The nanocomposite was made by binding the GO flakes to kaolin with the help of 3-Aminopropyltriethoxysilane (APTES). The GO flakes in the nanocomposite were contacting neighboring GO flakes as observed by electron microscopy. After thermal annealing, the nanocomposite become conductive as showed by sheet resistance measurements. Based on the conductance changes of the nanocomposite films, electrical gas sensing devices were made for detecting NH3 and HNO3. These devices had a higher sensitivity than thermally annealed multilayer GO films. This kaolin-GO nanocomposite might be useful in applications that require a low-cost material with large conductive surface area including the demonstrated gas sensors.

  • 1167802.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Andersson, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edlund, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Edström, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edvardsson, Sverker
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Forsberg, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Johansson, Niklas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Karlsson, Kristoffer
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nilsson, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Norgren, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Olsen, Martin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Uesaka, Tetsu
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Öhlund, Thomas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Soap-film coating: High-speed deposition of multilayer nanofilms2013In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 3, p. Art. no. 1477-Article in journal (Refereed)
    Abstract [en]

    The coating of thin films is applied in numerous fields and many methods are employed for the deposition of these films. Some coating techniques may deposit films at high speed; for example, ordinary printing paper is coated with micrometre-thick layers of clay at a speed of tens of meters per second. However, to coat nanometre thin films at high speed, vacuum techniques are typically required, which increases the complexity of the process. Here, we report a simple wet chemical method for the high-speed coating of films with thicknesses at the nanometre level. This soap-film coating technique is based on forcing a substrate through a soap film that contains nanomaterials. Molecules and nanomaterials can be deposited at a thickness ranging from less than a monolayer to several layers at speeds up to meters per second. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology.

  • 1167803.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edström, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edvardsson, Sverker
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Forsberg, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Johansson, Niklas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Kalsson, Kristoffer
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nilsson, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Olsen, Martin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Öhlund, Thomas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    High-speed deposition of multilayer nanofilms using soap-film coating2013Conference paper (Refereed)
    Abstract [en]

    High-speed deposition of multilayer nanofilms using soap-film coating

    Renyun Zhang, Henrik A. Andersson, Mattias Andersson, Britta Andres, Per Edström, Sverker Edvardsson, Sven Forsberg, Magnus Hummelgård, Niklas Johansson, Kristoffer Karlsson, Hans-Erik Nilsson, Martin Olsen, Tetsu Uesaka, Thomas Öhlund & Håkan Olin

    Department of Applied Science and Design, Mid Sweden University, SE-85170 Sundsvall, Sweden

    Email: renyun.zhang@miun.se or hakan.olin@miun.se

    Coating1 of thin films is of importance for making functionalized surfaces with applications in many fields from electronics to consumer packaging. To decrease the cost, large scale roll-to-roll2 coating techniques are usually done at high speed, for example, ordinary printing paper is coated at a speed of tens of meters per second by depositing micrometer thick layers of clay. However, nanometer thin films are harder to coat at high speed by wet-chemical methods, requiring special roll-to-roll vacuum techniques3 with the cost of higher complexity.

    Here, we report a simple wet chemical method for high-speed coating of films down to molecular thicknesses, called soap-film coating (SFC)4. The technique is based on forcing a substrate through a soap film that contains nanomaterials. In the simplest laboratory version, the films can be deposited by a hand-coating procedure set up in a couple of minutes. The method is quite general molecules or nanomaterials or sub-micrometer materials (Figure 1) with thicknesses ranging from less than a monolayer to several layers at speeds up to meters per second. The applications of soap-film coating is quite wide an we will show solar cells, electrochromic devices, optical nanoparticle crystals, and nano-film devices. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology.

    Fig. 1. Soap film coating of nanoparticles, layered materials, nanowires, and molecules. a sub-monolayer 240 nm silica nanoparticle (scale bar 2 µm) b monolayer c double layer. d monolayer gold nanoparticles. e single layer TiO2 nanoparticles. f sub-monolayer polystyrene (scale 2 µm), g monolayer of polystyrene. h triple-layer of polystyrene. i monolayer of Ferritin.  j AFM image of <1.5 layer GO film (3 µm x 2 µm). k clay on glass (scale 2 µm). l SFC coated nanocellulose. m Absorbance spectra Rhodamine B on a glass slide. AFM of SDS layers n (2 µm x 1.5 µm) and o (20 µm x 15 µm).

    References

    1. Tracton, A. A. Coating Technology Handbook (CRC Press, Boca Raton, 2006).

    2. Ohring, M. Materials science of thin films. (Academic press., 2001).

    3. Charles, B. Vacuum deposition onto webs, films and foils. (William Andrew, 2011).

    Zhang, R. Y., Andersson, H. A., Andersson, M., Andres, B., Edström, P., Edvardsson, S., Forsberg, S., Hummelgård, M., Johansson, N., Karlsson, K., Nilsson, H.-E., Olsen, M., Uesaka, T., Öhlund, T., Olin H. Soap film coating: High-speed deposition of multilayer nanofilms. Submitted.

  • 1167804.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olsen, Martin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edvardsson, Sverker
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nilsson, Hans-Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Piezoelectric gated ZnO nanowire diode studied by in situ TEM probing2014In: Nano Energy, ISSN 2211-2855, Vol. 3, p. 10-15Article in journal (Refereed)
    Abstract [en]

    The piezoelectricity of ZnO nanowires has shown rising interests during the last few years and fields such as piezotronics and piezophotonics are emerging with a number of applications and devices. One such device is the piezoelectric gated ZnO nanowire diode, where the p–n junction is replaced by a dynamically created potential barrier created simply by bending the otherwise homogeneously doped nanowire. To further study this type of diode we used in situ transmission electron microscope (TEM) probing, where one electrode was fixed at the end of a ZnO nanowire and another moveable electrode was used both for bending and contacting the wire. Thereby we were able to further characterise this diode and found that the diode characteristics depended on whether the contact was made to the stretched (p-type) surface or to the compressed (n-type) surface of the wire. When the neutral line of the wire contacted, between the stretched and the compressed side, the I–V characteristics were independent on the current direction. The performance of the diodes upon different bending intensity showed a rectifying ratio up to the high value of 60:1. The diode ideality factor was found to be about 5. Moreover, the reverse breakdown voltages of the diode were measured and a local but permanent damage to the diode action was found when the voltage went over the reverse breakdown voltage. 

  • 1167805.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Carlsson, Fredrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Edman, Mattias
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Jonsson, Bengt-Gunnar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Escherichia coli Bacteria Develop Adaptive Resistance to Antibacterial ZnO Nanoparticles2018In: Advanced Biosystem, ISSN 2366-7478, Vol. 2, no 5, article id 1800019Article in journal (Refereed)
    Abstract [en]

    Antibacterial agents based on nanoparticles (NPs) have many important applications, e.g., for the textile industry, surface disinfection, wound dressing, water treatment, and food preservation. Because of their prevalent use it is important to understand whether bacteria could develop resistance to such antibacterial NPs similarly to the resistance that bacteria are known to develop to antibiotics. Here, it is reported that Escherichia coli(E. coli) develops adaptive resistance to antibacterial ZnO NPs after several days' exposure to the NPs. But, in contrast to antibiotics‐resistance, the observed resistance to ZnO NPs is not stable—after several days without exposure to the NPs, the bacteria regain their sensitivity to the NPs' antibacterial properties. Based on the analyses it is suggested that the observed resistance is caused by changes in the shape of the bacteria and the expressions of membrane proteins. The findings provide insights into the response of bacteria to antibacterial NPs, which is important to elucidate for designing and evaluating the risk of applications based on antibacterial NPs.

  • 1167806.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Engholm, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Recent Progress on the Fabrication and Properties of Silver Nanowire-Based Transparent Electrodes2018In: Nanomaterials, ISSN 2079-4991, Vol. 8, no 8, article id 628Article in journal (Refereed)
    Abstract [en]

    Transparent electrodes (TEs) made of metallic nanowires, such as Ag, Au, Cu, and Ni, are attracting increasing attention for several reasons: (1) they can act as a substitute for tin oxide-based TEs such as indium-tin oxide (ITO) and fluorine-doped tin oxide (FTO); (2) various methods exist for fabricating such TEs such as filtration, spraying, and Meyer bar coating; (3) greater compatibility with different substrates can be achieved due to the variety of fabrication methods; and (4) extra functions in addition to serving as electrodes, such as catalytic abilities, can be obtained due to the metals of which the TEs are composed. There are a large number of applications for TEs, ranging from electronics and sensors to biomedical devices. This short review is a summary of recent progress, mainly over the past five years, on silver nanowire-based TEs. The focus of the review is on theory development, mechanical, chemical, and thermal stability as well as optical properties. The many applications of TEs are outside the scope of this review.

  • 1167807.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Engholm, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Örtegren, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    High-performance transparent and flexible electrodes made by flash-light sintering of gold nanoparticles2018In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 1, no 12, p. 7191-7198Article in journal (Refereed)
    Abstract [en]

    Metallic nanowire-based transparent electrodes (TEs) are potential alternatives to indium tin oxide (ITO). To achieve a high performance [sheet resistance (Rs) < 100 Ω/sq, transmittance (T%) > 90%], the nanowires must have a high length-to-diameter (L/D) ratio to minimize the number of wire-to-wire junctions. Attempts to produce TEs with gold nanowires have been made, and the results reveal difficulties in achieving the requirements. A successful strategy involves creating templated gold nanonetworks through multiple procedures. Here, we present a simple and efficient method that uses flash-light sintering of a gold nanonetwork film into gold TEs (Rs: 82.9 Ω/sq, T %: 91.79%) on a thin polycarbonate film (25 μm). The produced gold TEs have excellent mechanical, electrical, optical, and chemical stabilities. Mechanisms of the formation of gold nanonetworks and the effect of flash-light have been analyzed. Our findings provide a scalable process for producing transparent and flexible gold electrodes with a total processing time of less than 8 min without the use of heating, vacuum processing, and organic chemicals and without any material loss. This is possible because all the gold nanoparticles have been aggregated and filtrated on the filter membranes. The area density of gold is 0.094 g/m2 leading low material costs, which is very competitive with the price of commercial TEs.

  • 1167808.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Dvorsek, D
    Jozef Stefan Institute, Slovenia and Mo6, Ljubljana, Slovenia.
    Mihailovic, D
    Jozef Stefan Institute, Slovenia and Mo6, Ljubljana, Slovenia.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Mo6S3I6-Au composites: Synthesis, Conductance, and Applications2010In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 348, no 2, p. 299-302Article in journal (Refereed)
    Abstract [en]

    A single-step, premixing method was used to directly deposit gold nanoparticles on Mo6S3I6 (MSI) molecular wire bundles. Gold nanoparticles with different sizes and densities were coated on the MSI by changing the concentration of the gold containing salt, HAuCl4. TEM, SEM, and EDX characterization showed deposition of gold nanoparticles on the MSI nanowire surface. The electrical resistance of these MSI-Au composites was more than 100 times lower than that for pure MSI, and was mainly dependent on the density of the deposited gold nanoparticles. Furthermore, we immobilized thiol group-labeled oligonucleotide on the composites and then hybridized with a fully matched sequence. The resistance of the MSI-Au composites increased during the thiol step, while it decreased by hybridizing, due to the conductance difference between single- and double-stranded DNA chains. These results indicate that this new kind of MSI-Au composite could be used as a platform for different applications, including biosensors.

  • 1167809.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Forsberg, Viviane
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Engholm, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Öhlund, Thomas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olsen, Martin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Örtegren, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Photoconductivity of acid exfoliated and flash-light-processed MoS2 films2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 3296Article in journal (Refereed)
    Abstract [en]

    MoS2 has been studied intensively during recent years as a semiconducting material in several fields, including optoelectronics, for applications such as solar cells and phototransistors. The photoresponse mechanisms of MoS2 have been discussed but are not fully understood, especially the phenomenon in which the photocurrent slowly increases. Here, we report on a study of the photoresponse flash-light-processed MoS2 films of different thicknesses and areas. The photoresponse of such films under different light intensities and bias voltages was measured, showing significant current changes with a quick response followed by a slow one upon exposure to pulsed light. Our in-depth study suggested that the slow response was due to the photothermal effect that heats the MoS2; this hypothesis was supported by the resistivity change at different temperatures. The results obtained from MoS2 films with various thicknesses indicated that the minority-carrier diffusion length was 1.36 mu m. This study explained the mechanism of the slow response of the MoS2 film and determined the effective thickness of MoS2 for a photoresponse to occur. The method used here for fabricating MoS2 films could be used for fabricating optoelectronic devices due to its simplicity.

  • 1167810.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lv, Gang
    N China Elect Power Univ, Dept Math & Phys, Baoding 071003, Peoples R China.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Real time monitoring of the drug release of rhodamine B on graphene oxide2011In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 49, no 4, p. 1126-1132Article in journal (Refereed)
    Abstract [en]

    A real time method for monitoring the drug load and release on graphene oxide (GO) in a cuvette is reported using rhodamine B (RB) as a model for a drug. The mechanisms of the release of RB at different pH were investigated, by monitoring the time dependency of the accumulative drug release. In vitro real time experimental results indicated that RB could be loaded on GO with a capacity of 0.5 mg/mg. The drug release of RB was pH sensitive as observed at pH 7.4 and pH 4.5 PBS solutions. The higher pH values lead to weaker hydrophobic force and hydrogen bonds, and thus higher release rate. The ionic strength also influenced the release of RB, as shown from the different release rates between PBS solutions and double distilled water. These results indicated a case II transport process at pH 7.4 and an anomalous diffusion process at pH 4.5 and in water. The method described here allows real time detection of the drug release rate, in contrast to common dialysis analysis. This method also points to other real time detections in biomedical investigations.

  • 1167811.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    A facile one-step method for synthesising a parallelogram-shaped single-crystalline ZnO nanosheet2014In: Materials Science and Engineering: B, ISSN 0921-5107, Vol. 184, p. 1-6Article in journal (Refereed)
    Abstract [en]

    ZnO nanosheets are found to be useful in many fields such as sensors and electronics. Non-uniform- shaped ZnO nanosheets are synthesised using several methods; moreover, uniformly shaped ones are less studied. Here, we report on a simple one-step method to synthesise parallelogram-shaped single- crystalline ZnO nanosheets. By controlling the reaction of Zn(NO3 )2 and hexamethylenetetramine (HMT) in ethanol, average 30 nm-thick nanosheets with a high aspect ratio of 1:100 were obtained. The par- allelogram angles were between 97◦ and 99◦. Transmission electron microscopy (TEM) diffraction and X-ray diffraction (XRD) showed that the nanosheets were wurtzite-structured single-crystalline ZnO. Moreover, a growth mechanism of these parallelogram nanosheets is suggested based on the experi- mental results. These results suggest a new simple solution process to synthesise uniformly shaped ZnO nanosheets allowing large-scale production to be employed. 

  • 1167812.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Carbon nanocages grown by gold templating2010In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 48, no 2, p. 424-430Article in journal (Refereed)
    Abstract [en]

    A method for growing carbon cages using gold nanoparticles as templates is reported. Gold nanoparticles were deposited on carbon nanotubes (CNTs). The nanocages were grown on the gold particles by electrical Joule heating of the CNT. The gold was subsequently evaporated, leaving the cages intact. A special in-situ TEM-holder equipped with a small scanning tunneling microscope was used as an electrical probe to drive current through the CNT, while the TEM was used for imaging of the entire growth process. The method might provide a general way for making carbon structures limited only by the shapes allowed by the fabrication methods of the gold nanostructures.

  • 1167813.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Carbon nanocages templated by gold nanostructures2010In: Vacuum Electron Sources Conference and Nanocarbon (IVESC), 2010 8th International, IEEE conference proceedings, 2010, p. 469-469Conference paper (Refereed)
    Abstract [en]

    Summary form only given. Hollow nanocages are useful in many applications including catalyst support, batteries and drug delivery. Several systems have been pursued to produce nanocages, but for carbon, studied cages are mainly smaller ones, like fullerenes. Attempts to make larger carbon nanocages are more limited, resulting in foam-like structures with relatively thick walls or by methods that do not easily get controllable sizes. For applications of nanocages there are needs for methods that allow carbon cages to be fabricated with determined size and shape. Here, we report on a new method to grow large carbon cages, using gold nanoparticles on carbon nanotubes as templates (Figure 1). The experiments were done inside a TEM using a special in-situ holder, called TEMSTM, with movable electrical probes, allowing a detailed observation and control of the entire process. The cages were grown on the nanoparticles under electrical Joule heating and the gold were subsequently evaporated, leaving the cages intact. The templating gold nanoparticles could be made in different sizes allowing size adjustments of the resulting carbon nanocages. The obtained cages may have wide applications including drug delivery and hydrogen storage.

  • 1167814.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Graphite-carbon nanotube flexible electrodes for dye-sensitized solar cells2014Conference paper (Refereed)
    Abstract [en]

    Dye-sensitized solar cell (DSSC) is a low cost and efficient way to transform solar radiation to electricity. Indium tin oxide (ITO) and fluorine doped tin oxide (FTO) coated glass are two kinds of transparent electrodes that are mostly used to fabricate DSSCs. However, these two kinds electrodes lack flexibility, limiting their development. [1] Flexible electrodes are desired in DSSC because of they are lightweight, low cost and ro田l-to-roll compatible. There are attempts to replace both [1] or one [2] of the two electrodes in DSSC. However, the efficiencies are relatively low. Here we reported a simple method to fabricate graphite-carbon nanotube (G-CNT) composited flexible electrode for using as counter electrode in DSSC. The electrodes are simple fabricated by reverse filtration and flash sintering, leading to highly flexible (360 °C) and conductive (sheet resistance, 100 Ohm/sq) electrodes that can be used as both catalyzer and current collector. The energy conversion efficiency of such electrode based DSSC can reach 2.02% with fill factor of 0.56 (Figure 1).

     

    Figure 1. Photograph of the G-CNT composited flexible electrode, and the J-V characterization of the fabricated DSSC.

     

     

    References:

     

    [1]    W. Wang, Q. Zhang, H. Li, G. W. Wu, D. C. Zou, D. P. Yu, Adv. Funct. Mater. 2012, 22, 2775-2782.

    [2]    B. Wang, L. L. Kerr, Sol. Energy Mater. Sol. Cells. 2011, 95, 2531-2535.

  • 1167815.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Large area porous gold films deposited by evaporation-induced colloidal crystal growth2009In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 340, no 1, p. 58-61Article in journal (Refereed)
    Abstract [en]

    Films that are nanostructured in two- or three-dimensions, such as porous ones, are made by several methods including templated growth and self-assembly. Here, we report on a new method that is based on evaporation-induced growth of nanoparticle gold films on a water surface. The film growth was done in a similar way to the well-known evaporation-induced colloidal crystal growth method, but in contrast, we did not directly deposit the film on a solid substrate. The films were instead created on top of a water surface. After the growth process, the films were deposited directly on substrates by a simple pick-up procedure. The deposited porous gold films were uniform with a thickness of 100 nm and had a sheet resistance of 100 Ω/sq. There are several advantages with our method, including simplicity of the protocol, large film area, flexibility in the choice of substrate to be coated, and the ability for multilayer coatings. The latter points to opportunities for fabrication of multilayer 3D porous structure, which may have wide applications in sensors and electrochemical determinations.

  • 1167816.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Simple and efficient gold nanoparticles deposition on carbon nanotubes with controllable particle sizes2009In: Materials Science & Engineering: B. Solid-state Materials for Advanced Technology, ISSN 0921-5107, E-ISSN 1873-4944, Vol. 158, no 1-3, p. 48-52Article in journal (Refereed)
    Abstract [en]

    There are important applications of multiwalled carbon nanotubes (MWCNT) with deposited nanoparticles and several methods exist for synthesizing these nanocomposites. However, a simpler and more efficient method is desired in many cases. Here, we introduce a method where MWCNT were pre-mixed with sodium citrate, and using ultrasonication, shells of sodium citrate were formed on the nanotubes. These functionalized MWCNTs served as substrates for gold nanoparticle growth. When HAuCl4 was added to the reaction system, Au3+ was directly reduced at the surface of the MWCNT and gold nanoparticles were assembled along the MWCNT. Transmission electron microscopy (TEM) demonstrated that the density of the gold nanoparticle coating process depended on the amount of the carbon nanotubes when the sodium citrate concentration was keep unchanged. In addition, by controlling the concentration of sodium citrate and HAuCl4, the size of gold nanoparticles could be controlled. Scanning electron microscope (SEM), energy dispersive X-ray (EDX), and UV–vis were also used to characterize the MWCNT–Au nanocomposites. Compared with other methods, the procedure described here required only water solutions and there are no needs for high temperature steps, surfactants or organic solvents, resulting in a simple and fast method for efficient gold nanoparticle decoration of carbon nanotubes.

  • 1167817.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Simple Fabrication of Gold Nanobelts and Patterns2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 1, p. Art. no. e30469-Article in journal (Refereed)
    Abstract [en]

    Gold nanobelts are of interest in several areas; however, there are only few methods available to produce these belts. We report here on a simple evaporation induced self-assembly (EISA) method to produce porous gold nanobelts with dimensions that scale across nanometer (thickness ~80 nm) and micrometer (width ~20 μm), to decimeter (length ~0.15 m). The gold nanobelts are well packed on the beaker wall and can be easily made to float on the surface of the solution for depositing onto other substrates. Microscopy showed that gold nanobelts had a different structure on the two sides of the belt; the density of gold nanowires on one side was greater than on the other side. Electrical measurements showed that these nanobelts were sensitive to compressive or tensile forces, indicating a potential use as a strain sensor. The patterned nanobelts were further used as a template to grow ZnO nanowires for potential use in applications such as piezo-electronics. © 2012 Zhang et al.

  • 1167818.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Simple Synthesis of Clay-Gold Nanocomposites with Tunable Color2010In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 26, no 8, p. 5823-5828Article in journal (Refereed)
    Abstract [en]

    Clay-based nanocomposites have been studied for several decades, mainly focusing on clay-polymer nanocomposites. Here, we report on a simple wet chemical method to synthesize clay-APTES-Au (CAAu) nanocomposites, where 3-aminopropyltriethoxysilane (APTES) acts as the linkage. The silane terminal of APTES formed bonds with the clay surface, while the other -NH(2) terminal bonds to gold nanoparticles. The color of clay changed when these CAAu nanocomposites were formed. By changing the size of the gold nanoparticles, the color of CAAu could be adjusted, simply by changing process parameters. TEM characterization of the synthesized nanocomposites showed an even distribution of gold nanoparticles on the clay surfaces. The nanocomposites were stable in strong acid and high concentration of salt conditions, while strong basic solution like NaOH could slightly influence the status of the gold nanoparticles due to the rupture of the Si-O-Si bonds between APTES and clay. To demonstrate the potential for label free sensing application of CAAu nanocomposites, we made hybrids of clay-APTES-Au-HD-Au (CAAuHAu), where hexamethylene diamine (HD) served as links between CAAu nanocomposites and the gold nanoparticles. The color of the composites changed from red to blue, when the hybrids were formed. Moreover, hemoglobin was loaded on the CAAu nanocomposites, which can potentially be used as a biosensor. These synthesized nanocomposites may combine the catalytic properties of clay and the well-known excellent properties of gold nanoparticles, such as the ability to anchor biological and chemical molecules. Furthermore, the color change of CAAu, when the CAAuHAu hybrids were observed, suggests the applications of these nanocomposites in biochemical and chemical sensing.

  • 1167819.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Single layer porous gold films grown at different temperatures2010In: Physica. B, Condensed matter, ISSN 0921-4526, E-ISSN 1873-2135, Vol. 405, no 21, p. 4517-4522Article in journal (Refereed)
    Abstract [en]

    Large area porous gold films can be used in several areas including electrochemical electrodes, as an essential component in sensors, or as a conducting material in electronics. Here, we report on evaporation induced crystal growth of large area porous gold films at 20, 40 and 60 °C. The gold films were grown on liquid surface at 20 °C, while the films were grown on the wall of beakers when temperature increased to 40 and 60 °C. The porous gold films consisted of a dense network of gold nanowires as characterized by TEM and SEM. TEM diffraction results indicated that higher temperature formed larger crystallites of gold wires. An in situ TEM imaging of the coalescence of gold nanoparticles mimicked the process of the growth of these porous films, and a plotting of the coalescence time and the neck radius showed a diffusion process. The densities of these gold films were also characterized by transmittance, and the results showed film grown at 20 °C had the highest density, while the film grown at 60 °C had the lowest consistent with SEM and TEM characterization. Electrical measurements of these gold films showed that the most conductive films were the ones grown at 40 °C. The conductivities of the gold films were related to the amount of contamination, density and the diameter of the gold nanowires in the films. In addition, a gold film/gold nanoparticle hybrid was made, which showed a 10% decrease in transmittance during hybridization, pointing to applications as chemical and biological sensors. © 2010 Elsevier B.V. All rights reserved.

  • 1167820.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Size and concentration controlled growth of porous gold nanofilm2012In: Physica status solidi. A, Applied research, ISSN 0031-8965, E-ISSN 1521-396X, Vol. 209, no 3, p. 519-523Article in journal (Refereed)
    Abstract [en]

    At an air/water interface, diffusion-limited aggregation (DLA) of gold nanoparticles can form porous gold thin films. This porous film roughly consists of a network of irregular nanowires. For this air–water system, external parameters like temperature are well studied, while the influence of internal parameters, e.g., the size and concentration of the nanoparticles, have not been studied in detail. Here, we report on the growth of porous gold nanofilms for different nanoparticle sizes and concentrations to get a relationship between the morphology of the films and the internal parameters. The gold nanoparticles were synthesized by reducing HAuCl4 using sodium citrate. Transmission electron microscopy (TEM) characterization

    showed a linear relation between the formed gold nanowires and the concentration of HAuCl4 if the concentration of sodium citrate is unchanged. A linear dependency was also found between the wire diameter and the gold nanoparticle concen- tration, and between the wire diameter and volume fraction of the nanoparticles. The electrical resistance of the films was measured, showing a linear relation between resistance and the inverse of the cross-sectional area of the nanowires. This study shows the relation between the morphology and resistance of the grown porous films and the controllable internal parameters that will be useful in further exploration of this thin-film growth method.

  • 1167821.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olsen, Martin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Örtegren, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nanogenerator made of ZnO nanosheet networks2017In: Semiconductor Science and Technology, ISSN 0268-1242, E-ISSN 1361-6641, Vol. 32, no 5, article id 054002Article in journal (Refereed)
    Abstract [en]

    The piezoelectricity of nanomaterials attracts a great deal of attention due to its broad application, including the harvesting of ambient mechanical energy to power small electronics devices. We report here a simple method to fabricate piezoelectric nanogenerators consisting of networks of ZnO nanosheets grown on aluminum (Al) foils, where the Al acts as both a substrate for growth and as an electrode contacting the ZnO network. A second, top electrode was tapped, rolled, or rubbed against the ZnO to generate piezoelectricity. This second electrode was either a copper foil or fluorine doped tin oxide (FTO) glass. A piezo voltage of up to 0.924 V was detected during rolling and 6 μA was the highest current observed when rubbing the ZnO film with a FTO glass. Due to its simplicity, this nanogenerator fabrication method has the potential to be scaled up for the industrial production of piezoelectric energy harvesting devices.

  • 1167822.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Örtegren, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olsen, Martin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Interaction of the human body with triboelectric nanogenerators2019In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 57, p. 279-292Article in journal (Refereed)
    Abstract [en]

    The use of triboelectric nanogenerators (TENGs) is a new technique for energy harvesting at both small and large scales. Almost all types of mechanical energy can be harvested with TENGs by using four modes of operation that cover almost all mechanical motions. The interactions of the human body with TENGs range from energy harvesting, motion sensing, and biomedical applications to human-computer communications. Different types of TENGs have been developed to directly or indirectly involve the human body. This review will summarize the recent advances in the interaction of the human body with TENGs.

  • 1167823.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Örtegren, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olsen, Martin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Yang, Ya
    CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P. R. China.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Human body constituted triboelectric nanogenerators as energy harvesters, code transmitters and motion sensors2018In: ACS Applied Energy Materials, ISSN 2574-0962, Vol. 1, no 6, p. 2955-2960Article in journal (Refereed)
    Abstract [en]

    Human skin is a dielectric material that can be used as a triboelectric material for harvesting energy from body motions. The output power of such a human skin-based triboelectric nanogenerator (TENG) is relatively low. Here, we assembled high-output human body constituted TENGs (H-TENGs) by taking advantage of the unique electrical properties of the human body, such as high skin impedance, low tissue resistance, body capacitance, and conductivity. The output of a H-TENG can reach 30 W/m2, which is enough to drive small electronic devices, such as a timer or a calculator. The unique feature of the H-TENG is that it can perform the four fundamental modes of TENGs, which has not been reported elsewhere. Such a feature allows the H-TENG to act as a code transmitter to send light and electrical signals, such as Morse code. H-TENGs also benefit the development of high-performance, self-powered body motion sensors. Our findings suggest new strategies for harvesting energy from human body motions, as well as new types of motion sensors and signal senders.

  • 1167824.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Örtegren, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Yang, Ya
    Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, PR China; University of Chinese Academy of Science, Beijing, PR China.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Balliu, Enkeleda
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Blomquist, Nicklas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Engholm, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Olsen, Martin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Wang, Zhong Lin
    Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, PR China; University of Chinese Academy of Science, Beijing, PR China; Georgia Institute of Technology, Atlanta, GA, USA.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Sensing body motions based on charges generated on the body2019In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 63, article id 103842Article in journal (Refereed)
    Abstract [en]

    The sensing of body motions is of great importance in areas such as healthcare, rehabilitation, and human-computer interactions. Different methods have been developed based on visual or electrical signals. However, such signals are acquired by external devices and are not intrinsic signals that are created on the body. Here, we report a new universal body motion sensor (UBS) to detect motions based on the intrinsic contact electrification (CE) of the skin or electrical induction (EI) of the body. The CE or EI generates charges on the body, leading to potential differences between the body and ground that can be measured to identify different body motions, such as motions of the head, arms, fingers, waist, legs, feet and toes. Proof-of-concept experiments have demonstrated that the UBS can be used to monitor the conditions of people with Parkinson's disease (PD) and to quantitatively monitor the recovery of those with a leg injury, suggesting great potential for healthcare applications.

  • 1167825.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Carbon nanomaterials as drug carriers: Real time drug release investigation2012In: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 32, no 5, p. 1247-1252Article in journal (Refereed)
    Abstract [en]

    The use of carbon nanomaterials in biomedical applications and the cytotoxicity of these materials have been areas of great interest during the last decade. In vitro drug load and release, as well as in vivo animal tests, have been carried out using carbon nanomaterials. However, no comparison studies on the drug load and the release of different carbon nanomaterials have been reported. Here, we report on a real time investigation of the drug release of carbon black (CB) nanoparticles, carbon nanotubes (CNTs) and graphene oxide (GO), using rhodamine B (RB) as a model of drug. The binding of RB to the nanomaterials were characterized by FTIR and UV-vis. The mass loading capacities of these nanomaterials were also studied, showing that GO had the highest capacity. The real time drug release experiment indicated different accumulative release modes of these nanomaterials at different pH values, due to their different binding modes with RB, which is also discussed as being the reason for the mechanism differences. Moreover, the comparison of the drug release capacity of CNT-RB and f-CNT-RB (functionalized-CNT-RB) indicated an influence of hydrogen bonds in both drug loading and release, as the hydrogen bonds increased the loading capacity of the carbon nanotube after acid treatment and changed the drug release mechanism at pH 7.4. Thus, here we identified the drug release modes of the different carbon nanomaterials. The results of the influence of functional groups and hydrogen bonds point also out a potential way of controlling the drug release behavior of carbon nanomaterials by surface modification. © 2012 Elsevier B.V. All rights reserved.

  • 1167826.
    Zhang, RenYun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Gold-carbon nanotube nanocomposites - synthesis and applications2011In: International Journal of Biomedical Nanoscience and Nanotechnology, ISSN 1756-0799, Vol. 2, no 2, p. 112-135Article, review/survey (Refereed)
    Abstract [en]

    Nanocomposites are combinations of nanomaterials with other molecules or nanoscaled materials, such as nanoparticles or nanotubes. In general, these novel nanocomposites have different physical and chemical properties from the constituent particles or wires, and will thus allow new kinds of applications. Among these nanocomposites, gold-carbon nanotube (Au-CNT) composites are of particular interests, due to their easy fabrication protocols and broad potential applications. Au-CNT nanocomposites commonly refer to gold nanoparticles deposited on carbon nanotubes. To obtain Au-CNT nanocomposites, different methods have been developed, including direct and linked deposition of gold nanoparticles on CNT. Au-CNT nanocomposites combine the excellent physical and chemical properties of both gold nanoparticles and carbon nanotubes. The easy modification surface of gold nanoparticle and the excellent conductivity of carbon nanotube as well the high surface area, point towards a broad range of applications, such as biosensing, gas sensing, and electrochemistry. This paper reviews the recent progress of different kinds of Au-CNT nanocomposites and their synthesis and applications.

  • 1167827.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Magnetic Nanoparticles in Biomedical Applications2011In: OMICS: Biomedical Perspectives and Applications / [ed] Debmalya Barh, Kenneth Blum, Margaret A. Madigan, CRC Press, 2011, 1Chapter in book (Refereed)
  • 1167828.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Porous Gold Films: A Short Review on Recent Progress2014In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 7, p. 3834-3854Article, review/survey (Refereed)
    Abstract [en]

    Porous gold films have attracted increasing interest over the last ten years due to the unique properties of high specific surface area and electrical conductivity combined with chemical stability and ability to alter the surface chemistry. Several methods have been developed to synthesize porous gold films such as de-alloying, templating, electrochemical, and self-assembling. These porous gold films are used in diverse fields, for example, as electrochemical and Raman sensors or for chemical catalysis. Here, we provide a short review on the progress of porous gold films over the past ten years, including the synthesis and applications of such films.

  • 1167829.
    Zhang, Renyun
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Örtegren, Jonas
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Hummelgård, Magnus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Olsen, Martin
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, Henrik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Electronics Design.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Harvesting triboelectricity from the human body using non-electrode triboelectric nanogenerators2018In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 45, p. 298-303Article in journal (Refereed)
    Abstract [en]

    Triboelectrification has been known and discussed since antiquity. Triboelectrification occurs in the human body due to friction between human skin and other materials such as clothing. However, charges on the body have not been harvested to power small electronics. Here, we report for the first time that the electricity generated on the human body due to triboelectrification can be measured and harvested using human body-based non-electrode triboelectric nanogenerators (H-TENGs). The H-TENGs can have an output of up to 3.3 W/m(2) and can spontaneously harvest energy from several people. The functions of the human body in the H-TENGs are analyzed and experimentally proven to be those of a triboelectric material, conductor and capacitor. Our results demonstrate that the triboelectricity generated on a human body can be harvested using H-TENGs and provide scientific insights into body functions that will promote further studies of TENGs.

  • 1167830.
    Zhang, Ri-Chao
    et al.
    Zhejiang University, Peoples R China; Queens University of Belfast, North Ireland; University of Ulster, North Ireland.
    Sun, Dan
    Queens University of Belfast, North Ireland.
    Lu, Ai
    China Academic Engn Phys, Peoples R China.
    Askari Ghotbabadi, Sadegh
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, Faculty of Science & Engineering.
    Macias-Montero, Manuel
    University of Ulster, North Ireland.
    Joseph, Paul
    Victoria University, Australia.
    Dixon, Dorian
    University of Ulster, North Ireland.
    Ostrikov, Kostya
    Queensland University of Technology, Australia; CSIRO, Australia.
    Maguire, Paul
    University of Ulster, North Ireland.
    Mariotti, Davide
    University of Ulster, North Ireland.
    Microplasma Processed Ultrathin Boron Nitride Nanosheets for Polymer Nanocomposites with Enhanced Thermal Transport Performance2016In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 8, no 21, p. 13567-13572Article in journal (Refereed)
    Abstract [en]

    This Research Article reports on the enhancement of the thermal transport properties of nanocomposite materials containing hexagonal boron nitride in poly(vinyl alcohol) through room-temperature atmospheric pressure direct-current microplasma processing. Results show that the microplasma treatment leads to exfoliation of the hexagonal boron nitride in isopropyl alcohol, reducing the number of stacks from amp;gt;30 to a few or single layers. The thermal diffusivity of the resulting nanocomposites reaches 8.5 mm(2) s(-1) times greater than blank poly(vinyl alcohol) and twice that of nanocomposites containing nonplasma treated boron nitride nanosheets. From TEM analysis, we observe much less aggregation Of the nanosheets after plasma processing along with indications of an amorphous carbon interfacial layer, which may contribute to stable dispersion of boron nitride nanosheets in the resulting plasma treated colloids.

  • 1167831.
    Zhang, Ri-Chao
    et al.
    East China Jiaotong University, Peoples R China; Queens University, North Ireland; University of Ulster, North Ireland; University of Loughborough, England.
    Sun, Dan
    Queens University, North Ireland.
    Zhang, Ruirui
    East China Jiaotong University, Peoples R China; Queens University, North Ireland; University of Ulster, North Ireland; University of Loughborough, England.
    Lin, Wen-Feng
    University of Loughborough, England.
    Macias-Montero, Manuel
    University of Ulster, North Ireland.
    Patel, Jenish
    Marwadi Educ Fdn Grp Institute, India.
    Askari Ghotbabadi, Sadegh
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, Faculty of Science & Engineering.
    McDonald, Calum
    University of Ulster, North Ireland.
    Mariotti, Davide
    University of Ulster, North Ireland.
    Maguire, Paul
    University of Ulster, North Ireland.
    Gold nanoparticle-polymer nanocomposites synthesized by room temperature atmospheric pressure plasma and their potential for fuel cell electrocatalytic application2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 46682Article in journal (Refereed)
    Abstract [en]

    Conductive polymers have been increasingly used as fuel cell catalyst support due to their electrical conductivity, large surface areas and stability. The incorporation of metal nanoparticles into a polymer matrix can effectively increase the specific surface area of these materials and hence improve the catalytic efficiency. In this work, a nanoparticle loaded conductive polymer nanocomposite was obtained by a one-step synthesis approach based on room temperature direct current plasmaliquid interaction. Gold nanoparticles were directly synthesized from HAuCl4 precursor in poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS). The resulting AuNPs/PEDOT: PSS nanocomposites were subsequently characterized under a practical alkaline direct ethanol fuel cell operation condition for its potential application as an electrocatalyst. Results show that AuNPs sizes within the PEDOT: PSS matrix are dependent on the plasma treatment time and precursor concentration, which in turn affect the nanocomposites electrical conductivity and their catalytic performance. Under certain synthesis conditions, unique nanoscale AuNPs/PEDOT: PSS core-shell structures could also be produced, indicating the interaction at the AuNPs/polymer interface. The enhanced catalytic activity shown by AuNPs/PEDOT: PSS has been attributed to the effective electron transfer and reactive species diffusion through the porous polymer network, as well as the synergistic interfacial interaction at the metal/polymer and metal/metal interfaces.

  • 1167832.
    Zhang, Rong
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Chemistry, Department of Biochemistry.
    New approaches to concentration, desalting and separation of biopolymers in capillary electrophoresis1997Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the first part of the thesis five new on-tube methods for concentration and desalting ofampholytes, such as peptides and proteins, are described in Papers I and II. The methods arebased on the fact that electrophoretic migration velocities decrease upon a decrease in theabsolute value of the zeta potential of a solute and the pore size of the electrophoresis mediumand upon an increase in the cross section of the electrophoresis chamber, the viscosity and theelectrical conductivity of the electrophoresis medium. A combination of displacementelectrophoresis and a hydrodynamic counter flow is also utilized to create a stationary zone inwhich the sample solute can be concentrated continuously. Paper III describes an on-tubedesalting technique for IEF, which is based on an automatic substitution of the salts in thesample with an ampholyte solution in a short focusing pre-step. A simple off-tubeconcentration and desalting method using a hollow fiber is described in Paper IV, which isbased on the transport of water by evaporation or the Donnan effect out of the fiber throughthe pores in its wall and has the advantage that solute adsorption is negligible. The method canbe used not only for macromolecules but also for low-molecular-weight compounds.

    The second part of thesis consists of two publications about HPCE in the presence ofadditives. In Paper V liposomes were used as a pseudostationary phase in CZE. The decreasein the mobility of an analyte owing to the presence of liposomes reflected interaction betweenanalytes and liposomes. Paper VI deals with the shifts in mobilities of peptides and proteinswhen buffers are supplemented with β-cyclodextrin sulfate and 6-amino β-cyclodextrin. A newdefinition of resolution of two very adjacent peaks, without knowing peak widths, is suggested.

    Studies of crystals of lysozyme and MBP by HPCE were presented in the last part of thethesis (Paper VII), which show that HPCE can be used to shed some light on the question whysome protein crystals afford low resolution upon X-ray diffraction.

  • 1167833. Zhang, Rong
    et al.
    Cho, Hae Yun
    Kim, Hyun Sic
    Ma, Young Gerl
    Osaki, Tsukasa
    Kawabata, Shun-ichiro
    Söderhäll, Kenneth
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Physiology and Developmental Biology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Physiology and Developmental Biology, Comparative Physiology. jämförande fysiologi.
    Lee, Bok Luel
    Characterization and properties of a 1,3-beta-D-glucan pattern recognition protein of Tenebrio molitor larvae that is specifically degraded by serine protease during prophenoloxidase activation.2003In: J Biol Chem, ISSN 0021-9258, Vol. 278, no 43, p. 42072-9Article in journal (Refereed)
  • 1167834. Zhang, Rong guang
    et al.
    Andersson, C Evalena
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Savchenko, Alexei
    Skarina, Tatiana
    Evdokimova, Elena
    Beasley, Steven
    Arrowsmith, Cheryl H
    Edwards, Aled M
    Joachimiak, Andrzej
    Mowbray, Sherry L
    Structure of Escherichia coli ribose-5-phosphate isomerase: a ubiquitous enzyme of the pentose phosphate pathway and the Calvin cycle2003In: Structure, ISSN 0969-2126, E-ISSN 1878-4186, Vol. 11, no 1, p. 31-42Article in journal (Refereed)
    Abstract [en]

    Ribose-5-phosphate isomerase A (RpiA; EC 5.3.1.6) interconverts ribose-5-phosphate and ribulose-5-phosphate. This enzyme plays essential roles in carbohydrate anabolism and catabolism; it is ubiquitous and highly conserved. The structure of RpiA from Escherichia coli was solved by multiwavelength anomalous diffraction (MAD) phasing, and refined to 1.5 A resolution (R factor 22.4%, R(free) 23.7%). RpiA exhibits an alpha/beta/(alpha/beta)/beta/alpha fold, some portions of which are similar to proteins of the alcohol dehydrogenase family. The two subunits of the dimer in the asymmetric unit have different conformations, representing the opening/closing of a cleft. Active site residues were identified in the cleft using sequence conservation, as well as the structure of a complex with the inhibitor arabinose-5-phosphate at 1.25 A resolution. A mechanism for acid-base catalysis is proposed.

  • 1167835.
    Zhang, Rong
    et al.
    Univ Bonn, Inst Human Genet, Bonn, Germany.;Univ Bonn, Dept Genom, Life & Brain Ctr, Bonn, Germany..
    Knapp, Michael
    Univ Bonn, Inst Med Biometry Informat & Epidemiol, Bonn, Germany..
    Suzuki, Kentaro
    Wakayama Med Univ, Inst Adv Med, Dev Genet, Wakayama, Japan..
    Kajioka, Daiki
    Wakayama Med Univ, Inst Adv Med, Dev Genet, Wakayama, Japan..
    Schmidt, Johanna M.
    Univ Bonn, Inst Human Genet, Bonn, Germany.;Univ Bonn, Inst Anat, Bonn, Germany..
    Winkler, Jonas
    Univ Bonn, Inst Anat, Bonn, Germany..
    Yilmaz, Oeznur
    Univ Bonn, Inst Anat, Bonn, Germany..
    Pleschka, Michael
    Univ Bonn, Inst Anat, Bonn, Germany..
    Cao, Jia
    Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden..
    Kockum, Christina Clementson
    Univ Lund Hosp, Dept Pediat Surg, Lund, Sweden..
    Barker, Gillian
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health, Paediatric Surgery.
    Holmdahl, Gundela
    Queen Silvias Childrens Hosp, Dept Pediat Surg, Gothenburg, Sweden..
    Beaman, Glenda
    Univ Manchester, Ctr Genom Med, Manchester M13 9PL, Lancs, England..
    Keene, David
    Woolf, Adrian S.
    Univ Manchester, Manchester Acad Hlth Sci, Inst Human Dev, Manchester M13 9PL, Lancs, England.;Royal Manchester Childrens Hosp, Manchester, Lancs, England..
    Cervellione, Raimondo M.
    Cent Manchester Univ Hosp NHS Fdn Trust, Royal Manchester Childrens Hosp, Paediat Urol, Manchester, Lancs, England..
    Cheng, Wei
    Capital Inst Pediat, Dept Pediat Surg, Beijing, Peoples R China.;Monash Univ, Fac Med Nursing & Hlth Sci, Southern Med Sch, Dept Paediat, Clayton, Vic, Australia.;Monash Univ, Fac Med Nursing & Hlth Sci, Southern Med Sch, Dept Surg, Clayton, Vic, Australia.;Beijing United Family Hosp, Dept Surg, Beijing, Peoples R China..
    Wilkins, Simon
    Cabrini Monash Univ, Cabrini Hosp, Dept Surg, Melbourne, Vic, Australia.;Monash Univ, Sch Publ Hlth & Prevent Med, Dept Epidemiol & Prevent Med, Clayton, Vic 3800, Australia..
    Gearhart, John P.
    Johns Hopkins Sch Med, Div Pediat Urol, Baltimore, MD USA..
    Sirchia, Fabio
    Univ Torino, Citta Salute & Sci Univ Hosp, Dept Med Sci, Turin, Italy.;Univ Torino, Citta Salute & Sci Univ Hosp, Med Genet Unit, Turin, Italy..
    Di Grazia, Massimo
    IRCCS Burlo Garofalo, Inst Maternal & Child Hlth, Trieste, Italy..
    Ebert, Anne-Karolin
    Univ Hosp Ulm, Dept Urol & Pediat Urol, Ulm, Germany..
    Roesch, Wolfgang
    St Hedwig Hosp Barmherzige Bruder, Dept Pediat Urol, Regensburg, Germany..
    Ellinger, Joerg
    Univ Hosp Bonn, Dept Urol, Bonn, Germany..
    Jenetzky, Ekkehart
    German Canc Res Ctr, Div Clin Epidemiol & Aging Res, Heidelberg, Germany.;Johannes Gutenberg Univ Mainz, Dept Child & Adolescent Psychiat & Psychotherapy, Mainz, Germany..
    Zwink, Nadine
    German Canc Res Ctr, Div Clin Epidemiol & Aging Res, Heidelberg, Germany..
    Feitz, Wout F.
    Radboud Univ Nijmegen, Med Ctr, Pediat Urol Ctr, Dept Urol, Nijmegen, Netherlands..
    Marcelis, Carlo
    Radboud Univ Nijmegen, Med Ctr, Dept Genet, Nijmegen, Netherlands..
    Schumacher, Johannes
    Univ Bonn, Inst Human Genet, Bonn, Germany..
    Martinon-Torres, Federico
    Hosp Clin Univ Santiago, Translat Pediat & Infect Dis, Santiago De Compostela, Spain.;Inst Invest Sanitaria Santiago Santiago, GENVIP Res Grp Www Genvip Org, Galicia, Spain..
    Hibberd, Martin Lloyd
    Genome Inst Singapore, Singapore, Singapore..
    Khor, Chiea Chuen
    Univ Calif Davis, Med Ctr, Dept Pediat, Div Genom Med, Sacramento, CA 95817 USA..
    Heilmann-Heimbach, Stefanie
    Univ Bonn, Inst Human Genet, Bonn, Germany.;Univ Bonn, Dept Genom, Life & Brain Ctr, Bonn, Germany..
    Barth, Sandra
    Univ Bonn, Inst Human Genet, Bonn, Germany.;Univ Bonn, Dept Genom, Life & Brain Ctr, Bonn, Germany..
    Boyadjiev, Simeon A.
    Univ Calif Davis, Med Ctr, Dept Pediat, Div Genom Med, Sacramento, CA 95817 USA..
    Brusco, Alfredo
    Univ Torino, Citta Salute & Sci Univ Hosp, Dept Med Sci, Turin, Italy.;Univ Torino, Citta Salute & Sci Univ Hosp, Med Genet Unit, Turin, Italy..
    Ludwig, Michael
    Univ Bonn, Dept Clin Chem & Clin Pharmacol, Bonn, Germany..
    Newman, William
    Univ Manchester, Ctr Genom Med, Manchester M13 9PL, Lancs, England..
    Nordenskjold, Agneta
    Karolinska Univ Hosp, Astrid Lindgren Children Hosp, Pediat Surg, Stockholm, Sweden..
    Yamada, Gen
    Wakayama Med Univ, Inst Adv Med, Dev Genet, Wakayama, Japan..
    Odermatt, Benjamin
    Univ Bonn, Inst Anat, Bonn, Germany..
    Reutter, Heiko
    Univ Bonn, Inst Human Genet, Bonn, Germany.;Childrens Hosp, Dept Neonatol & Pediat Intens Care, Bonn, Germany.;Univ Bonn, Bonn, Germany..
    ISL1 is a major susceptibility gene for classic bladder exstrophy and a regulator of urinary tract development2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 42170Article in journal (Refereed)
    Abstract [en]

    Previously genome-wide association methods in patients with classic bladder exstrophy (CBE) found association with ISL1, a master control gene expressed in pericloacal mesenchyme. This study sought to further explore the genetics in a larger set of patients following-up on the most promising genomic regions previously reported. Genotypes of 12 markers obtained from 268 CBE patients of Australian, British, German Italian, Spanish and Swedish origin and 1,354 ethnically matched controls and from 92 CBE case-parent trios from North America were analysed. Only marker rs6874700 at the ISL1 locus showed association (p = 2.22 x 10(-08)). A meta-analysis of rs6874700 of our previous and present study showed a p value of 9.2 x 10(-19). Developmental biology models were used to clarify the location of ISL1 activity in the forming urinary tract. Genetic lineage analysis of Isl1-expressing cells by the lineage tracer mouse model showed Isl1-expressing cells in the urinary tract of mouse embryos at E10.5 and distributed in the bladder at E15.5. Expression of isl1 in zebrafish larvae staged 48 hpf was detected in a small region of the developing pronephros. Our study supports ISL1 as a major susceptibility gene for CBE and as a regulator of urinary tract development.

  • 1167836. Zhang, Rong-guang
    et al.
    Andersson, C. Evalena
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Savchenko, Alexei
    Skarina, Tatiana
    Evdokimova, Elena
    Beasley, Steven
    Arrowsmith, Cheryl H.
    Edwards, Aled M.
    Joachimiak, Andrzej
    Mowbray, Sherry L.
    Structure of Escherichia coli Ribose 5-phosphate Isomerase: A Ubiquitous Enzyme of the Pentose Phosphate Pathway and the Calvin Cycle2003In: Structure, Vol. 11, no 1, p. 31-42Article in journal (Refereed)
  • 1167837. Zhang, Rong-Guang
    et al.
    Andersson, C Evalena
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Skarina, Tatiana
    Evdokimova, Elena
    Edwards, Aled M
    Joachimiak, Andrzej
    Savchenko, Alexei
    Mowbray, Sherry L
    The 2.2 A resolution structure of RpiB/AlsB from Escherichia coli illustrates a new approach to the ribose-5-phosphate isomerase reaction2003In: Journal of Molecular Biology, ISSN 0022-2836, E-ISSN 1089-8638, Vol. 332, no 5Article in journal (Refereed)
    Abstract [en]

    Ribose-5-phosphate isomerases (EC 5.3.1.6) interconvert ribose 5-phosphate and ribulose 5-phosphate. This reaction permits the synthesis of ribose from other sugars, as well as the recycling of sugars from nucleotide breakdown. Two unrelated types of enzyme can catalyze the reaction. The most common, RpiA, is present in almost all organisms (including Escherichia coli), and is highly conserved. The second type, RpiB, is present in some bacterial and eukaryotic species and is well conserved. In E.coli, RpiB is sometimes referred to as AlsB, because it can take part in the metabolism of the rare sugar, allose, as well as the much more common ribose sugars. We report here the structure of RpiB/AlsB from E.coli, solved by multi-wavelength anomalous diffraction (MAD) phasing, and refined to 2.2A resolution. RpiB is the first structure to be solved from pfam02502 (the RpiB/LacAB family). It exhibits a Rossmann-type alphabetaalpha-sandwich fold that is common to many nucleotide-binding proteins, as well as other proteins with different functions. This structure is quite distinct from that of the previously solved RpiA; although both are, to some extent, based on the Rossmann fold, their tertiary and quaternary structures are very different. The four molecules in the RpiB asymmetric unit represent a dimer of dimers. Active-site residues were identified at the interface between the subunits, such that each active site has contributions from both subunits. Kinetic studies indicate that RpiB is nearly as efficient as RpiA, despite its completely different catalytic machinery. The sequence and structural results further suggest that the two homologous components of LacAB (galactose-6-phosphate isomerase) will compose a bi-functional enzyme; the second activity is unknown.

  • 1167838. Zhang, Rong-guang
    et al.
    Andersson, C. Evalena
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Skarina, Tatiana
    Evdokimova, Elena
    Edwards, Aled M.
    Joachimiak, Andrzej
    Savchenko, Alexei
    Mowbray, Sherry L.
    The 2.2 Å Resolution Structure of RpiB/AlsB from Escherichia coli Illutrates a New Approach to the Ribose 5-phosphate Isomerase Reaction2003In: Journal of Molecular Biology, Vol. 332, no 5, p. 1083-1094Article in journal (Refereed)
  • 1167839.
    Zhang, Ronglin
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology.
    Complex System Optimization: Subtask of Interactive Service Supporting System in Modern Service Industry2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report is a work description and summary for complex system optimization which is a sub-task of interactive service supporting system in modern service industry.

    There are seven parts in total of the report. The first part is project introduction. It introduces the origin and general background of the project. The second part is a summary of pre-study work, including the pros and cons of existing approaches and techniques to be used in the project. The third part is the system design. It not only gives functional requirements, indicates runtime environment, but also describes in detail the system architecture and several basic but important design ideas. The fourth part is the system implementation. The final system release is also given in the end of this part. Afterwards is conclusion part which sums up the whole work. In the end, there are abbreviations list and references for this report.

  • 1167840. Zhang, Rongwei
    et al.
    Ewalds-Kvist, Béatrice Marianne
    Stockholm University, Faculty of Social Sciences, Department of Psychology. University of Turku, Finland.
    Li, Dan
    Jiang, Jun
    Chinese Students' Satisfaction with Life Relative to Psychological Capital and Mediated by Purpose in Life2019In: Current Psychology, ISSN 1046-1310, E-ISSN 1936-4733, Vol. 38, no 1, p. 260-271Article in journal (Refereed)
    Abstract [en]

    Altogether 700 college students aged 18 to 24years (M=20.81, SD=1.29) originating from six universities in China participated in this study. The current aim was to find out whether a student's sense of purpose in life mediated the relationship between his/her psychological capital (PsyCap) comprising hope, generalized self-efficacy, resilience, optimism (HERO; Luthans and Youssef-Morgan. Annual Review of Organizational Psychology and Organizational Behavior, 4, 339-366, 2017) and satisfaction with life. Furthermore, it was asked which factor contributes more to students' satisfaction with life, PsyCap or purpose in life? Thus, apprentices completed the Adult Dispositional Hope Scale (Snyder et al. Journal of Personality and Social Psychology, 60(4), 570-585, 1991), General Self-Efficacy Scale (Schwarzer and Jerusalem. Causal and Control Beliefs, 1, 35-37, 1995), Resilience Scale (Wagnild and Young. Journal of Nursing Measurement, 1(2), 165-17847, 1993), Life Orientation Test-Revised (Scheier et al. Journal of Personality and Social Psychology, 67(6), 1063-1078, 1994) along with the completion of the Purpose in Life Test (Crumbaugh and Maholick. Journal of Clinical Psychology, 20(2), 200-207, 1964) and Satisfaction with life scale (Diener et al. Journal of Personality Assessment, 49(1), 71-75, 1985). The results disclosed grade differences in PsyCap elements. Moreover, positive and significant correlations between any of two variables were found, thus allowing for further analysis. Structural equation modeling revealed that students' satisfaction with life was directly predicted by PsyCap per se as well as indirectly projected by means of the construct purpose in life. Based on the present assessment, PsyCap contributed more to students' satisfaction with life than their experienced purpose in life.

  • 1167841. Zhang, Rongwei
    et al.
    Li, Dan
    Chen, Fei
    Ewalds-Kvist, Béatrice
    Stockholm University, Faculty of Social Sciences, Department of Psychology, Biological psychology. Turku University, Finland.
    Liu, Shihong
    Interparental Conflict Relative to Suicidal Ideation in Chinese Adolescents: The Roles of Coping Strategies and Meaning in Life2017In: Frontiers in Psychology, ISSN 1664-1078, E-ISSN 1664-1078, Vol. 8, p. 1-7, article id 1010Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to explore the paths between interparental conflict and Chinese adolescents' suicidal ideation. Altogether 931 adolescents (Mage = 17.84, SD = 0.77, females = 531) completed the Dyadic Consensus Scale, Self-Report Coping Scale, Meaning in Life Questionnaire, and Positive and Negative Suicide Ideation questionnaires. Mediation analyses were conducted, focusing on the relations between interparental conflict and suicidal ideation along with coping styles and a sense of meaning in life. The results showed that interparental conflict indirectly predicted adolescents' suicidal ideation via three mediators: coping-approach strategies, presence of meaning, and the joint serial effects of coping-approach strategies and presence of meaning in Chinese adolescents. In addition, boys were more likely to be at risk for suicidal ideation than girls, so were 10th graders compared to 11th graders. These findings supported a combined distress-to-meaninglessness line of thinking along with the use of coping-approach strategies to depress self-harm ideation. Generally, interparental conflict should be kept out of youngsters' immediate vicinity as a preventive measure of suicidal ideation.

  • 1167842.
    Zhang, Ru Bo
    et al.
    Beijing Intitute of Technology.
    Eriksson, Leif A.
    Örebro University, School of Science and Technology.
    Distinct Hydroxy-Radical-Induced Damage of 3-Uridine Monophosphate in RNA: A Theoretical Study2009In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 15, no 10, p. 2394-2402Article in journal (Refereed)
    Abstract [en]

    Cutting ties: Strand scission and base release in hydroxy-radical adducts of 3-uridine monophosphate (UMP) have been explored by using density functional theory. The presence of the ribose 2-OH group and the resultant formation of low-barrier hydrogen bonds with oxygen atoms of the 3-phosphate linkage are highly important for hydrogen transfer and the subsequent bond-breakage reactions (see picture).RNA strand scission and base release in 3-uridine monophosphate (UMP), induced by OH radical addition to uracil, is studied at the DFT B3LYP/6-31+G(d,p) level in the gas phase and in solution. In particular, the mechanism of hydrogen-atom transfer subsequent to radical formation, from C2 on the sugar to the C6 site on the base, is explored. The barriers of (C2-)H2a abstraction by the C6 radical site range from 11.2 to 20.0 kcal mol-1 in the gas phase and 14.1 to 21.0 kcal mol-1 in aqueous solution, indicating that the local surrounding governs the hydrogen-abstraction reaction in a stereoselective way. The calculated N1C1 (N1-glycosidic bond) and -phosphate bond strengths show that homolytic and heterolytic bond-breaking processes are largely favored in each case, respectively. The barrier for -phosphate bond rupture is approximately 3.2-4.0 kcal mol-1 and is preferred by 8-12 kcal mol-1 over N1-glycosidic bond cleavage in both the gas phase and solution. The -phosphate bond-rupture reactions are exothermal in the gas phase and solution, whereas N1C1 bond-rupture reactions require both solvation and thermal corrections at 298 K to be energetically favored. The presence of the ribose 2-OH group and its formation of low-barrier hydrogen bonds with oxygen atoms of the 3-phosphate linkage are highly important for hydrogen transfer and the subsequent bond-breakage reactions.

  • 1167843. Zhang, Ru bo
    et al.
    Eriksson, Leif A.
    Örebro University, Department of Natural Sciences.
    Effects of OH radical addition on proton transfer in the guanine-cytosine base pair2007In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 111, no 23, p. 6571-6576Article in journal (Refereed)
    Abstract [en]

    Double proton transfer (PT) reactions in guanine-cytosine OH radical adducts are studied by the hybrid density functional B3LYP approach. Concerted and stepwise proton-transfer processes are explored between N1(H) on guanine (G) and N3 on cytosine (C), and between N4(H) on C and O6 on G. All systems except GC6OH display a concerted mechanism. 8OHGC has the highest dissociation energy and is 1.2 kcal/mol more stable than the nonradical GC base pair. The origin of the interactions are investigated through the estimation of intrinsic acid-basic properties of the *OH-X monomer (X = G or C). Solvent effects play a significant role in reducing the dissociation energy. The reactions including *OH-C adducts have significantly lower PT barriers than both the nonradical GC pair and the *OH-G adducts. All reactions are endothermic, with the GC6OH --> GC6OHPT reaction has the lowest reaction energy (4.6 kcal/mol). In accordance with earlier results, the estimated NBO charges show that the G moiety carries a slight negative charge (and C a corresponding positive one) in each adduct. The formation of a partial ion pair may be a potential factor leading to the PT reactions being thermodynamically unfavored.

  • 1167844.
    Zhang, Ru Bo
    et al.
    Sch Sci, Inst Chem Phys, Beijing Inst Technol, Beijing, Peoples R China.
    Eriksson, Leif A.
    Örebro University, School of Science and Technology. Sch Chem, Natl Univ Ireland, Galway, Ireland.
    Theoretical study on conformational preferences of ribose in 2-thiouridine-the role of the 2 ' OH group2010In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 12, no 15, p. 3690-3697Article in journal (Refereed)
    Abstract [en]

    Conformational changes in ribose are well-known to play a significant role in biomolecular identification. The mechanism of selectivity towards C3'-endo conformation (conformer b) in ribose of 2-thiouridine has been studied using DFT (B3LYP) and MP2 methodology, together with 6-31+G(d,p) basis set. The polarity of the C2S2 bond is enhanced due to the orientation of H2' towards the S2 atoms, which leads to a difference in the corresponding bond lengths, the atomic charges and the vO2'H2' stretch vibrations in all the conformers. NBO analysis shows that charge transfer mainly occurs in the C2N3 and C2S2 orbitals. The higher stability of conformer b is attributed to its larger orbital interaction energies within the 2-thiouracil base, and total orbital interaction energies of conformer b. Our conclusion is that the distant electrostatic rather than hydrogen bonding effects between 2'OH and the S2 atoms play the dominant role in the orbital interaction, and enhance the selectivity towards the C3'-endo conformation of ribose.

  • 1167845. Zhang, Ru Bo
    et al.
    Gao, Feng xin
    Eriksson, Leif A.
    Örebro University, Department of Natural Sciences.
    Radical-induced damage in 3'dTMP: Insights into a mechanism for DNA strand cleavage2007In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 3, no 3, p. 803-810Article in journal (Refereed)
    Abstract [en]

    DNA strand scission and base release in 3‘dTMP, induced by H and OH radical addition to thymine, is studied at the DFT B3LYP/6-31+G(d,p) level in the gas phase and in solution. In particular the mechanism of H atom transfer subsequent to radical formation, from C2‘ on the sugar to the C6 site on the base, is explored. Bulk solvation is found to lower the barrier by up to 5 kcal mol-1 and the reaction energy by up to 12 kcal mol-1 for the hydroxyl radical adducts. The strengths of the N1−C1‘(N1-glycosidic bond) and C3‘−O(P) bonds are calculated, showing that homolytic bond breaking processes are largely favored in both cases. The barrier for C3‘−O(P) bond rupture is approximately 18.2 kcal mol-1, and its breakage is preferred by 10−15 kcal mol-1 over that of N1-glycosidic bond cleavage in both the gas phase and solvents, which is consistent with the changes in C3‘−O(P) and N1−C1‘ bond lengths during the H transfer reactions. Mulliken spin densities, NPA charges, and vertical electron affinities are calculated to clarify the reactive properties of the intramolecular H-transfer radicals.

  • 1167846. Zhang, Ru Bo
    et al.
    Zhang, Ke
    Eriksson, Leif A.
    Örebro University, Department of Natural Sciences.
    Theoretical studies of damage to 3'-uridine monophosphate induced by electron attachment2008In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 14, no 9, p. 2850-2856Article in journal (Refereed)
    Abstract [en]

    Low-energy electrons (LEE) are well known to induce nucleic acid damage. However, the damage mechanisms related to charge state and structural features remain to be explored in detail. In the present work, we have investigated the N1-glycosidic and C3'-O(P) bond ruptures of 3'-UMP (UMP=uridine monophosphate) and the protonated form 3'-UMPH with -1 and zero charge, respectively, based on hybrid density functional theory (DFT) B3 LYP together with the 6-31+G(d,p) basis set. The glycosidic bond breakage reactions of the 3'UMP and 3'UMPH electron adducts are exothermic in both cases, with barrier heights of 19-20 kcal mol(-1) upon inclusion of bulk solvation. The effects of the charge state on the phosphate group are marginal, but the C2'-OH group destabilizes the transition structure of glycosidic bond rupture of 3'-UMPH in the gas phase by approximately 5.0 kcal mol(-1). This is in contrast with the C3'-O(P) bond ruptures induced by LEE in which the charge state on the phosphate influences the barrier heights and reaction energies considerably. The barrier towards C3'-O(P) bond dissociation in the 3'UMP electron adduct is higher in the gas phase than the one corresponding to glycosidic bond rupture and is dramatically influenced by the C2'-OH group and bulk salvation, which decreases the barrier to 14.7 kcal mol(-1). For the C3'-O(P) bond rupture of the 3'UMPH electron adduct, the reaction is exothermic and the barrier is even lower, 8.2 kcal mol(-1), which is in agreement with recent results for 3'-dTMPH and 5'-dTMPH (dTMPH=deoxythymidine monophosphate). Both the Mulliken atomic charges and unpaired-spin distribution play significant roles in the reactions

  • 1167847.
    Zhang, Rui
    et al.
    University of Passau.
    Freund, Martin
    University of Passau.
    Amft, Oliver
    University of Passau.
    Cheng, Jingyuan
    DFKI.
    Zhou, Bo
    DFKI.
    Lukowicz, Paul
    DFKI.
    Seoane, Fernando
    KTH, School of Technology and Health (STH). Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Chabrecek, Peter
    Sefar AG.
    A generic sensor fabric for multi-modal swallowing sensing in regular upper-body shirts2016In: Proceedings of the 2016 ACM International Symposium on Wearable Computers, ACM Digital Library, 2016, p. 46-47Conference paper (Refereed)
    Abstract [en]

    We investigate a generic fabric material as basis for resistive pressure and bio-impedance sensors and apply the fabric in a shirt collar for swallowing spotting. A pilot study confirmed the signal performance of both sensor types.

  • 1167848.
    Zhang, Rui
    et al.
    University of Passau.
    Freund, Martin
    University of Passau.
    Amft, Oliver
    University of Passau.
    Cheng, Jingyuan
    DFKI.
    Zhou, Bo
    DFKI.
    Lukowicz, Paul
    DFKI.
    Seoane, Fernando
    University of Borås, Faculty of Textiles, Engineering and Business. KTH-School of Technology and Health.
    Chabrecek, Peter
    Sefar AG.
    A Generic Sensor Fabric for Multi-modal Swallowing Sensing in Regular Upper-body Shirts2016In: Proceedings of the 2016 ACM International Symposium on Wearable Computers, HEIDELBERG: ACM Digital Library , 2016, p. 46-47Conference paper (Refereed)
    Abstract [en]

    We investigate a generic fabric material as basis for resistive pressure and bio-impedance sensors and apply the fabric in a shirt collar for swallowing spotting. A pilot study confirmed the signal performance of both sensor types.

  • 1167849.
    Zhang, Rui Liang
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Rask, Lukas
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Storskalig svensk textilåtervinning: Aktuella problem och rekommendationer för framtiden2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The textile industry is facing new challenges as a result of increasing global textile consumptionand the increasing volume of waste. Due to the resource-intensive and environmentallyhazardous production of cotton, expectations are increasing to meet future demand for textileproducts with less resource-intensive and more environmentally friendly alternatives. Todaywe lack a large-scale Swedish textile recycling and the increased amount of textile waste canbe handled by means of circular economy. By scaling up a chemical recycling process withoutmajor material losses more sustainable alternatives to cotton can be obtained while managingthe waste efficiently. The recycling process converts cotton into dissolving pulp (a type oftextile pulp) for viscose production. Thus, we will during this project investigate the problemsthat exist and give our recommendations to implement such a textile recycling for Swedishtextile flows on a larger scale, viewed from a resource efficiency and environmentalperspective.We have made a qualitative study with emphasis on literature studies. Additional interviewshave been conducted to identify and map out various steps in the recycling process. In addition,the development of the textile industry has been analyzed. Based on this analysis, conclusionshave been drawn about how the future situation may be for cellulose-based textiles. Collection,sorting, mechanical and chemical recycling have been identified as main components in therecycling process and our conclusion is that they need to be developed simultaneously for aresource efficient and environmentally friendly textile recycling. The purpose is to avoiddifferent bottlenecks in the recycling process. A circular economy could therefore be achieved.Based on our analysis, a conclusion can be drawn that the textile industry is changing itscharacter and is becoming more chemically intensive, similar to a biorefinery, where allresidues are used.

  • 1167850. Zhang, Rui
    et al.
    Mao, Huahai
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Halli, Petteri
    Taskinen, Pekka
    Experimental phase stability investigation of compounds and thermodynamic assessment of the BaO–SiO2 binary system2016In: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 51, no 10, p. 4984-4995Article in journal (Refereed)
    Abstract [en]

    Phase equilibria were experimentally investigated at 1173 and 1523 K at the BaO-rich region in the BaO–SiO2 system. The phase assemblages were characterized by X-ray diffraction and scanning electron microscopy with energy dispersive X-ray analysis. Substitutional solution model and associate model were employed to describe the liquid phase. Two sets of self-consistent thermodynamic parameters were derived based on the obtained experimental results and literature data. Phase diagrams and thermodynamic properties were calculated using the thermodynamic parameters acquired. All the calculated results were compared with the experimental data in the present work and literature. Some new experimental studies of the melting behavior of the phase Ba3SiO5 and liquidus at the SiO2-rich corner are recommended to get a better fit for this system.

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