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  • 2851.
    Zhao, Ke
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Ferrighi, Lara
    Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø.
    Frediani, Luca
    Centre for Theoretical and Computational Chemistry, Department of Chemistry, University of Tromsø.
    Wang, Chuan-Kui
    College of Physics and Electronics, Shandong Normal University, Jinan .
    Luo, Yi
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Solvent effects on two-photon absorption of dialkylamino substituted distyrylbenzene chromophore2007Ingår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 126, nr 20Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Solvent effects on the two-photon absorption of a symmetrical diamino substituted distyrylbenzene chromophore have been studied using the density functional response theory in combination with the polarizable continuum model. It is shown that the dielectric medium has a rather small effect both on the bond length alternation and on the one-photon absorption spectrum, but it affects significantly the two-photon absorption cross section. It is found that both one- and two-photon absorptions are extremely sensitive to the planarity of the molecule, and the absorption intensity can be dramatically reduced by the conformation distortion. It has led to the conclusion that the experimentally observed anomalous solvent effect on the two-photon absorption of dialkylamino substituted distyrylbenzene chromophores cannot be attributed to the intrinsic properties of a single molecule and its interaction with solvents.

  • 2852.
    Zhao, Ke
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Liu, Ji-Cai
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Wang, Chuan-Kui
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Luo, Yi
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Modulation of supercontinuum generation and formation of an attosecond pulse from a generalized two-level medium2007Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics, ISSN 0953-4075, E-ISSN 1361-6455, Vol. 40, s. 1523-1534Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The propagation of ultrashort pulses in a generalized two- level system, consisting of permanent dipole moments, is simulated by solving the full Maxwell - Bloch equations. Special attention has been paid to the supercontinuum generation of spectra and the formation of attosecond ( as) pulses. It is found that the supercontinuum generation is strongly modulated by both area and width of the pulse, resulting from the interference between the splitting pulses in the time domain and the implication of the time - energy uncertainty relation. The effect of the permanent dipole moment on the supercontinuum generation is discussed in detail. Calculations show that a well- shaped 132 as pulse can be generated from a 2 fs incoming pulse under the condition where the permanent dipole moment difference between two levels is equal to the transition dipole moment between them. Influences of carrier- envelope phase and time- dependent ionization on the spectral and temporal evolution of the ultrashort pulses are also discussed at length.

  • 2853.
    Zhao, Ke
    et al.
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Wang, Chuan-Kui
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi.
    Luo, Yi
    Shandong Normal Univ, Coll Phys & Elect, Jinan.
    Two-photon absorbation activities of interating dipolar chromophores: a DFT study.Manuskript (preprint) (Övrigt vetenskapligt)
  • 2854.
    Zhao, Ning-Wei
    KTH, Skolan för bioteknologi (BIO).
    Recent Progress in the Methods of Genome Sequencing2010Ingår i: Brazilian archives of biology and technology, ISSN 1516-8913, E-ISSN 1678-4324, Vol. 53, nr 2, s. 319-325Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Genome sequencing is a very important tool for the development of genetic diagnosis, drugs of gene engineering, pharmacogenetics, etc. As the HGP comes into people's ears, there is an emerging need for the genome sequencing. During the recent years, there are two different traditional strategies available for this target: shotgun sequencing and hierarchical sequencing. Besides these, many efforts are pursuing new ideas to facilitate fast and cost-effective genome sequencing, including 454 GS system, polony sequencing, single molecular array, nanopore sequencing, with each having different unique characteristics, but remains to be fully developed.

  • 2855.
    Zhao, Ning-Wei
    et al.
    KTH, Skolan för bioteknologi (BIO).
    Yao, Jin-Ting
    Characterization and sequence identification of angiotensin II by a novel method involving ultra-fast liquid chromatography assay coupled with matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight five tandem mass spectrometry analysis2010Ingår i: European journal of mass spectrometry, ISSN 1469-0667, E-ISSN 1751-6838, Vol. 16, nr 6, s. 663-671Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-throughput proteomics aims to investigate dynamically changing proteins expressed by a full organism, specific tissue or cellular compartment under certain conditions. High-sensitivity mass spectrometry has gradually become a significant tool for characterizing peptides. Here, we analyzed angiotensin II using ultra-fast liquid chromatography (UFLC) coupled with matrix-assisted laser desoprtion/ionization time-of-flight mass spectrometry (MALDI-ToF MS5). First, we applied UFLC in isolating and collecting the angiotensin II, and then Axima-Resonance (MALDI-QIT-ToF MS5) was adopted, which enables collision-induced dissociation-MS5 analysis for fine structural characterization of angiotensin II. Resultant MS, MS2, MS3 and MS4 spectra of interested [M+H](+) ions selected as precursor ions yielded detailed information about the sites of fragmentation as well as the amino acid sequence for angiotensin II; meanwhile, the average deviation between theoretical mass and actually measured mass from MS to MS5 spectra was only 0.32 Da. It indicated that Axima-Resonance was capable of analysing the peptide sequence accurately and providing the corresponding fragmentation information thoroughly, thus suggesting a potential strategy involving UFLC assay coupled with MALDI-QIT-ToF MS5 analysis for high-throughput proteomics studies in the future.

  • 2856.
    Zhou, Xiaojian
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Sain, Mohini
    Centre for Biocomposites and Biomaterials Processing, University of Toronto, University of Toronto, Centre for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto.
    Oksman, Kristiina
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Semi-rigid biopolyurethane foams based on palm-oil polyol and reinforced with cellulose nanocrystals2016Ingår i: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 83, s. 56-62Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, water-blown biopolyurethane (BPU) foams based on palm oil were developed and cellulose nanocrystals (CNC) were incorporated to improve the mechanical properties of the foams. In addition, the foams were compared with petroleum polyurethane (PPU) foam. The foam properties and cellular morphology were characterized. The obtained results revealed that a low-density, semi-rigid BPU foam was prepared using a new formulation. CNC as an additive significantly improved the compressive strength from 54 to 117 kPa. Additionally, cyclic compression tests indicated that the addition of CNC increased the rigidity, leading to decreased deformation resilience. The dimensional stability of BPU foams was increased with increasing CNC concentration for both heating and freezing conditions.Therefore, the developed BPU nanocomposite foams are expected to have great potential as core material in composite sandwich panels as well as in other construction materials.

  • 2857.
    Zhou, Xiaojian
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Sethi, Jatin
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Geng, Shiyu
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Berglund, Linn
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Frisk, Nikolina
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Aitomäki, Yvonne
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Sain, Mohini
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Oksman, Kristiina
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Dispersion and reinforcing effect of carrot nanofibers on biopolyurethane foams2016Ingår i: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 110, s. 526-531Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, carrot nanofibers (CNF) were used to enhance the performance of biobased castor oil polyol polyurethane nanocomposite foams. A method of dispersing CNF in the polyol was developed and the foam characteristics and CNF reinforcing effect were studied. Co-solvent-assisted mixing resulted in well-dispersed CNF in the polyol, and foams with 0.25, 0.5 and 1 phr CNF content were prepared. The reinforced nanocomposite foams displayed a narrow cell size distribution and the compressive strength and modulus were significantly elevated and the best compressive strength and modulus were reached with 0.5 phr CNF. Similarly, the modulus of the solid material was also significantly increased based on theoretical calculations. When comparing the foam performance, compressive strength and stiffness as a function of the density, the nanocomposite foams performs as commercial rigid PU foam with a closed cell structure. These results are very promising and we believe that these foams are excellent core materials for lightweight sandwich composites.

  • 2858.
    Zhu, Chuantao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Dobryden, Illia
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Ryden, Jens
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Öberg, Sven
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Holmgren, Allan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Mathew, Aji P.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Adsorption Behavior of Cellulose and Its Derivatives toward Ag(I) in Aqueous Medium: An AFM, Spectroscopic, and DFT Study2015Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 31, nr 45, s. 12390-12400Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to develop a fundamental understanding of the adsorption behavior of metal ions on cellulose surfaces using experimental techniques supported by computational modeling, taking Ag(I) as an example. Force interactions among three types of cellulose microspheres (native cellulose and its derivatives with sulfate and phosphate groups) and the silica surface in AgNO3 solution were studied with atomic force microscopy (AFM) using the colloidal probe technique. The adhesion force between phosphate cellulose microspheres (PCM) and the silica surface in the aqueous AgNO3 medium increased significantly with increasing pH while the adhesion force slightly decreased for sulfate cellulose microspheres (SCM), and no clear adhesion force was observed for native cellulose microspheres (CM). The stronger adhesion enhancement for the PCM system is mainly attributed to the electrostatic attraction between Ag(I) and the negative silica surface. The observed force trends were in good agreement with the measured zeta potentials. The scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) analyses confirmed the presence of silver on the surface of cellulose microspheres after adsorption. This study showed that PCM with a high content of phosphate groups exhibited a larger amount of adsorbed Ag(I) than CM and SCM and possible clustering of Ag(I) to nanoparticles. The presence of the phosphate group and a wavenumber shift of the P−OH vibration caused by the adsorption of silver ions on the phosphate groups were further confirmed with computational studies using density functional theory (DFT), which gives support to the above findings regarding the adsorption and clustering of Ag(I) on the cellulose surface decorated with phosphate groups as well as IR spectra.

  • 2859.
    Zhu, Chuantao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Mathew, Aji P.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Morphology and surface interactions studies of nanocellulose using Atomic Force Microscopy2015Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    Force interactions between native cellulose microsphere (CM), sulfate cellulose microsphere (SCM), phosphate cellulose microsphere (PCM) and glass substrate under the effect of silver ions in the model solution were investigated using atomic force microscopy (AFM). The special interest was the influence of Ag+ ions and pH on the interaction between the probe and glass substrate. The probe was functionalized with above three types of cellulose microspheres by gluing method using contact mode with AFM. Functionalized probe and glass substrate were immersed in aqueous Ag+ solutions (50mg/L) at various pH value (4.25, 5.07, 5.62 and 6.63). Zeta potential studies showed negatively charged surfaces for CM, SCM, PCM and silica powders in model Ag+ solutions. The analysis revealed a decrease of adhesion force for CM and SCM system but an increase of adhesion force for PCM system with the increase of pH. The possible mechanism of the interaction under the effects of Ag+ ions, pH, and functional group contents as well as the shape of the cellulose microspheres was discussed. The SEM and SEM-EDS analysis confirmed the presence of silver ions on the surface of the cellulose microspheres after adsorption and force measurements.

  • 2860.
    Zhu, Chuantao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Mathew, Aji p.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Dobryden, Illia
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Adsorption behavior of cellulose and its derivatives for Ag+ in aqueous medium: An AFM and spectroscopy study2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cellulose particles in micro and nano scales has shown excellent potential to adsorb water pollutants such as dyes, pesticides, bacteria and virus, and a wide range of heavy metal ions, including Ag(Ⅰ), U(Ⅱ), Fe(Ⅲ), Cu(Ⅱ), Ni(Ⅱ), Cr(Ⅲ) and Zn(Ⅱ) 1, 2. However, mechanisms of adsorption and desorption the contaminants to/from cellulose micro or nano particles are largely unknown. The aim of the study was to develop fundamental understanding about the interaction and adsorption behavior of silver ions on cellulose surfaces using colloidal probe and spectroscopy techniques. Force interactions between three types of cellulose microspheres viz. native cellulose microspheres (CM), sulfate cellulose microspheres (SCM), phosphate cellulose microspheres (PCM) and silica surface in AgNO3 solution were studied with atomic force microscopy (AFM). The AFM results were further elaborated by extensive spectroscopy investigations.

  • 2861.
    Zhu, Chuantao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Materials and Environmental Chemistry, Stockholm University.
    Soldatov, Alexander
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Mathew, Aji
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Materials and Environmental Chemistry, Stockholm University.
    Advanced microscopy and spectroscopy reveal the adsorption and clustering of Cu(II) onto TEMPO-oxidized cellulose nanofibers2017Ingår i: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, nr 22, s. 7419-7428Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    TEMPO (2,2,6,6-tetramethylpiperidine-1-oxylradical)-mediated oxidation nanofibers (TOCNF), as a biocompatible and bioactive material, have opened up a new application of nanocellulose for the removal of water contaminants. This development demands extremely sensitive and accurate methods to understand the surface interactions between water pollutants and TOCNF. In this report, we investigated the adsorption of metal ions on TOCNF surfaces using experimental techniques atthe nano and molecular scales with Cu(II) as the target pollutant in both aqueous and dry forms. Imaging with in situ atomic force microscopy (AFM), together with a study of the physiochemical properties of TOCNF caused by adsorption with Cu(II) in liquid, were conducted using the PeakForce Quantitative NanoMechanics (PF-QNM) mode at the nano scale. The average adhesion force between the tip and the target single TOCNF almost tripled after adsorption with Cu(II) from 50 pN to 140 pN. The stiffness of the TOCNF was also enhanced because the Cu(II) bound to the carboxylate groups and hardened the fiber. AFM topography, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) mapping and X-ray photoelectron spectroscopy (XPS) indicated that the TOCNF were covered by copper nanolayers and/or nanoparticles after adsorption. The changes in the molecular structure caused by the adsorption were demonstrated by Raman and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). This methodology will be of great assistance to gain qualitative and quantitative information on the adsorption process and interaction between charged entities in aqueous medium.

  • 2862.
    Zhu, Youjian
    et al.
    School of Energy and Power Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450002, People’s Republic of China.
    Piotrowska, Patrycja
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    van Eyk, Philip Joseph
    School of Chemical Engineering, University of Adelaide, Adelaide, South Australia 5005, Australia.
    Boström, Dan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Wu, Xuehong
    School of Energy and Power Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450002, People’s Republic of China.
    Boman, Christoffer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik, Energiteknik och termisk processkemi.
    Broström, Markus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Zhang, Jun
    School of Energy and Power Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan 450002, People’s Republic of China.
    Kwong, Chi Wai
    School of Chemical Engineering, University of Adelaide, Adelaide, South Australia 5005, Australia.
    Wang, Dingbiao
    School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, Henan 450001, People’s Republic of China.
    Cole, Andrew J
    MACRO, the Centre for Macroalgal Resources and Biotechnology, James Cook University, Townsville, Queensland 4811, Australia.
    de Nys, Rocky
    MACRO, the Centre for Macroalgal Resources and Biotechnology, James Cook University, Townsville, Queensland 4811, Australia.
    Gentili, Francesco G.
    Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences (SLU), 901 83 Umeå, Sweden.
    Ashman, Peter J.
    School of Chemical Engineering, University of Adelaide, Adelaide, South Australia 5005, Australia.
    Fluidized bed co-gasification of algae and wood pellets: gas yields and bed agglomeration analysis2016Ingår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 30, nr 3, s. 1800-1809Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Algae utilization in energy production has gained increasing attention as a result of its characteristics, such as high productivity, rapid growth rate, and flexible cultivation environment. In this paper, three species of algae, including a fresh water macroalgae, Oedogonium sp., a saltwater macroalgae, Derbersia tenuissima, and a microalgae species, Scenedesmus sp., were studied to explore the potential of using smaller amounts of algae fuels in blends with traditional woody biomasses in the gasification processes. Co-gasification of 10 wt % algae and 90 wt % Swedish wood pellets was performed in a fluidized bed reactor. The effects of algae addition on the syngas yield and carbon conversion rate were investigated. The addition of 10 wt % algae in wood increased the CO, H2, and CH4 yields by 3–20, 6–31, and 9–20%, respectively. At the same time, it decreased the CO2 yield by 3–18%. The carbon conversion rates were slightly increased with the addition of 10 wt % macroalgae in wood, but the microalgae addition resulted in a decrease of the carbon conversion rate by 8%. Meanwhile, the collected fly ash and bed material samples were analyzed using scanning electron microscopy combined with an energy-dispersive X-ray detector (SEM–EDX) and X-ray diffraction (XRD) technique. The fly ashes of wood/marcoalgae tests showed a higher Na content with lower Si and Ca contents compared to the wood test. The gasification tests were scheduled to last 4 h; however, only wood and wood/Derbersia gasification experiments were carried out without significant operational problems. The gasification of 10 wt % Oedogonium N+ and Oedogonium N– led to defluidization of the bed in less than 1 h, and the wood/Scenedesmus (WD/SA) test was stopped after 1.8 h as a result of severe agglomeration. It was found that the algae addition had a remarkable influence on the characteristics and compositions of the coating layer. The coating layer formation and bed agglomeration mechanism of wood/macroalgae was initiated by the reaction of alkali compounds with the bed particles to form low-temperature melting silicates (inner layer). For the WD/SA test, the agglomeration was influenced by both the composition of the original algae fuel as well as the external mineral contaminations. In summary, the operational problems experienced during the co-gasification tests of different algae–wood mixtures were assigned to the specific ash compositions of the different fuel mixtures. This showed the need for countermeasures, specifically to balance the high alkali content, to reach stable operation in a fluidized bed gasifier.

  • 2863. Zhu, Youjian
    et al.
    van Eyk, Philip J.
    Boman, Christoffer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Broström, Markus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Kirtania, Kawnish
    Piotrowska, Patrycja
    Boström, Dan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    de Nys, Rocky
    Bhattacharya, Sankar
    Gentili, Francesco G.
    Ashman, Peter J.
    Preliminary understanding on the ash behavior of algae during co-gasification in an entrained flow reactor2018Ingår i: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 175, s. 26-34Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Algae are considered as a promising alternative fuel to produce energy due to its advantages such as high production yield, short growth cycle and flexible growing environment. Unfortunately, ash-related issues restrict its thermochemical utilization due to the high ash content and especially the high alkali metal concentration. In this paper, the gasification performance and ash behavior were experimentally analysed for three macro- and micro-algal species. Clear differences in the proximate and ultimate compositions were found between the cultivated algae used in this study and macroalgae (seaweed) harvested from the marine environments. Algal biomass generally contained higher Na and P contents than lignocellulosic biomass. Microalgae also had a relatively high mineral content due to the impurities in the harvesting process which included centrifugal pumping followed by sedimentation. Co-gasification of 20 wt% algae with softwood was investigated using an entrained flow reactor. The addition of both macroalgal species Derbersia tenuissima and Oedogonium to softwood had a limited influence on the gas yields and carbon conversion. On the other hand, the addition of the microalgal species Scenedesmus significantly decreased the main gas yields and carbon conversion. Moreover, the addition of algae clearly changed the residual ash composition of the base fuel. Finally, a preliminary understanding of the ash behavior of the tested algae blends was obtained through the analysis of the fuel ashes and the collected residual ashes. Fouling and corrosion were presumably occurred during the co-gasification of wood/macroalgae blends in view of the high alkali metal content. Microalga Scenedesmus had a high mineral content which could potentially capture the alkali metal in the ash and mitigate fouling when gasified with softwood. The growing environment and harvesting method were found to be significantly affecting the ash behavior implying the need for careful consideration regarding co-gasification process.

  • 2864.
    Zieba, Agata
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Ponten, Fredrik
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Uhlen, Mathias
    KTH Royal Inst Technol, Sci Life Lab, Stockholm, Sweden..
    Landegren, Ulf
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för immunologi, genetik och patologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    In situ protein detection with enhanced specificity using DNA-conjugated antibodies and proximity ligation2018Ingår i: Modern Pathology, ISSN 0893-3952, E-ISSN 1530-0285, Vol. 31, nr 2, s. 253-263Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Antibodies are important tools in anatomical pathology and research, but the quality of in situ protein detection by immunohistochemistry greatly depends on the choice of antibodies and the abundance of the targeted proteins. Many antibodies used in scientific research do not meet requirements for specificity and sensitivity. Accordingly, methods that improve antibody performance and produce quantitative data can greatly advance both scientific investigations and clinical diagnostics based on protein expression and in situ localization. We demonstrate here protocols for antibody labeling that allow specific protein detection in tissues via bright-field in situ proximity ligation assays, where each protein molecule must be recognized by two antibodies. We further demonstrate that single polyclonal antibodies or purified serum preparations can be used for these dual recognition assays. The requirement for protein recognition by pairs of antibody conjugates can significantly improve specificity of protein detection over single-binder assays.

  • 2865.
    Zimmermann, Tanja
    et al.
    Swiss Federal Laboratories for Materials Testing and Research (EMPA).
    Tingaut, P.
    Eyholzer, Christian
    Richter, Klaus
    Applications of nanofibrillated cellulose in polymer composites2012Konferensbidrag (Refereegranskat)
  • 2866. Zirk, Katrin
    et al.
    Langel, Ülo
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi. University of Tartu, Estonia.
    Vectorization of splice-correcting oligonucleotides with cell-penetrating peptides2013Ingår i: Chimica oggi, ISSN 0392-839X, E-ISSN 1973-8250, Vol. 31, nr 2, s. 12-15Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Personalized medicine approaches based on different gene therapy settings have gained much attention lately. In order to enforce successful gene therapy, genetic material needs to be delivered into cells. Nucleic acids and their analogues are unable to do so and thus require assistance to reach their site of action residing in the cytoplasm or nucleus. Here we give a short review on recent advancements in cell-penetrating peptide mediated delivery of splice-correcting oligonucleotides. We report on different cell-penetrating peptides applied for vectorization of splice-correcting oligonucleotides using both covalent conjugation and non-covalent nanoparticle formation approach. While covalent conjugation has gained extensive interest, there have also been great advances in non-covalent complex formation.

  • 2867.
    Åberg, Katarina
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Pommer, Linda
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Nordin, Anders
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Syngas production by combined biomass gasification and in situ biogas reforming2015Ingår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 29, nr 6, s. 3725-3731Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For small- to medium-sized streams of biogas (methane) produced at a biorefinery site where cost-efficient reforming by traditional methods are unavailable, combined biomass gasification and methane reforming could facilitate co-conversion and increase the H-2/CO ratio in the syngas from the gasification plant. In the present work, co-gasification of biomass with CH4 was evaluated by means of a parametric chemical equilibrium study for both wood/CH4 and black liquor/CH4 feedstocks and bench-scale fluidized-bed gasification experiments for a wood/peat/CH4 fuel mixture. The parametric study indicated that high-temperature, and steam and oxygen addition all facilitate a high conversion rate, i.e., methane reforming. Evaluating the influence of the gasification temperature on CH4 reforming and increasing the H-2/CO ratio experimentally demonstrated that high temperatures are required for efficient co-conversion.

  • 2868.
    Åhlin, Mikaela
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för biologisk grundutbildning.
    Mapping the binding site of the Hof1p SH3 domain in the Bnr1p FH1 domain2014Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The unusual syndrome Wiskott-Aldrich Syndrome has been found to be linked to a mutation in a gene expressing the Wiskott-Aldrich Syndrome protein (WASp). Due to the conservation of certain mechanisms and the homologous proteins from lower to higher eukaryotes, yeast has been used to study the molecular mechanisms that underlie diseases in humans. The yeast WASp homologue, Las17p (Local Anaexthetic Sentivie 17) and the yeast homologye Vrpp of its (i.e. human WASp) partner protein known as WIP (WASp-interacting protein), have been studied with the intention to investigate the phenotypes that arise in cells deficient in Vrp1p. A protein-protein interaction is believed to occur in the absence of Vrp1p, the interaction between the SH3 domain of the yeast F-Bar protein Hof1p and the FH1 domain of the yeast formin protein Bnr1p. This interaction is thought to have pathological effects, such as inhibition of cell proliferation and other phenotypes.

    This study has been conducted in an attempt to map the binding site of Hof1p SH3 domain in the Bnr1p FH1 domain more specifically, based on previous studies suggesting that Fragment 1(755-905) of Bnr1p Full Interacting Fragment(755-1375), including the proline- rich FH1 domain, interacts with Hof1p SH3 domain in cells deficient in Vrp1p. Both Hof1p and Bnr1p are involved in the cytokinesis stagemof the yeast cell cycle. The hypothesis implies that the excessive interaction of Hof1p SH3 domain and Bnr1p FH1 domain may interrupt the cytokinesis, which thereby can lead to the growth of defects.

    There was no finding of binding site within the Bnr1p FH1 domain for the Hof1p SH3 domain during this study. This can be due to various reason as explained later. Even though, this study has cast some doubts on previously conducted studies.

  • 2869.
    Åkerlund, Elin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Development of polymer based composite filaments for 3D printing2019Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The relatively new and still growing field of 3D-printing has opened up the possibilities to manufacture patient-specific medical devices with high geometrical accuracy in a precise and quick manner. Additionally, biocompatible materials are a demand for all medical applications while biodegradability is of importance when developing scaffolds for tissue growth for instance. With respect to this, this project consisted of developing biocompatible and bioresorbable polymer blend and composite filaments, for fused deposition modeling (FDM) printing. Poly(lactic acid) (PLA) and polycaprolactone (PCL) were used as supporting polymer matrix while hydroxyapatite (HA), a calcium phosphate with similar chemical composition to the mineral phase of human bone, was added to the composites to enhance the biological activity. PLA and PCL content was varied between 90–70 wt% and 10-30 wt%, respectively, while the HA content was 15 wt% in all composites. All materials were characterized in terms of mechanical properties, thermal stability, chemical composition and morphology. An accelerated degradation study of the materials was also executed in order to investigate the degradation behavior as well as the impact of the degradation on the above mentioned properties. The results showed that all processed materials exhibited higher mechanical properties compared to the human trabecular bone, even after degradation with a mass loss of around 30% for the polymer blends and 60% for the composites. It was also apparent that the mineral accelerated the polymer degradation significantly, which can be advantageous for injuries with faster healing time, requiring only support for a shorter time period.

  • 2870.
    Östrand, Therese
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Analysis of CHS, MEB5.2, PDX1.3 and PR-5 expression in Arabidopsis thaliana ecotypes during UV-B irradiation.2010Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
  • 2871.
    Özdemir, Gonca
    Växjö universitet, Fakulteten för matematik/naturvetenskap/teknik, Institutionen för teknik och design.
    Optimering av biogasproduktion från gödsel2009Självständigt arbete på grundnivå (kandidatexamen), 30 poäng / 45 hpStudentuppsats (Examensarbete)
    Abstract [en]

                          In this study, the bioconversion of manure and silage to biogas by an anaerobic digestion process in batch reactors was studied. Biogas is a valuable alternative energy source, mainly in rural areas. The main aim for the environment is to use biogas as a fuel instead of crude oil or natural gas. In this study, two different parameters were studied to observe the changes in methane productivity. The first three reactors were shaken once per week and the following three reactors were shaken 5 times per week. The results showed that mixing has no major effect on the methane production yield. In the second six reactors a mixture of 1% and 3% silage was added and the results were recorded. When the data from the reactors with just manure was compared to the reactors with 1% and 3% silage, it was seen that the silage increased the production rate and total gas produced. The process stabilization took a long time for digestion with the 3% silage possibly caused by release of too much fatty acids.

  • 2872.
    New EU criteria for endocrine disrupters: Consequences for the food chain2018Bok (Övrigt vetenskapligt)
    Abstract [en]

    Endocrine disruptors (EDs) are substances that adversely affect hormone function. The effects by EDs are thought to depend on both dose and timing of exposure, especially during foetal development. The upcoming EU regulation on identification of EDs, application biocides and pesticides, will have an impact on all actors of the food chain. The consequences of a ban of EDs in foods were discussed in a Nordic workshop (Uppsala, 29-30 Nov 2016) where risk assessors and managers from Nordic food authorities, industry, trade associations, consumer organizations and researchers were represented. It was recognized by all participants that a ban was particularly challenging for the production chain since there are few viable alternatives. A harmonized EU legislation based on scientific risk assessment was preferred compared to national specific legislation as it treats all the actors equally.

  • 2873.
    Jonsson, Magnus (Författare till förord, introducerande material, etc.)
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Centrum för forskning om inbyggda system (CERES).
    Widén, Kristian (Författare till förord, introducerande material, etc.)
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Centrum för innovations-, entreprenörskaps- och lärandeforskning (CIEL), Sustainability, Innovation and Management in Building (SIMB).
    Profile Area Smart Cities and Communities: 2019 Annual Report2020Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 2874. Oksman, Kristiina (Redaktör)
    Wood based composites: Proceedings from Nordic research course at Lövånger 22-27 March 19921992Rapport (Övrigt vetenskapligt)
55565758 2851 - 2874 av 2874
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