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  • 251.
    Dabrowski, Patrik
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013).
    Rening av rökgaskondensat i ett fjärrvärmeverk: Återanvändning av rökgaskondensat som spädvatten2017Independent thesis Basic level (university diploma), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    Arvika Fjärrvärme AB is manufacturing and distributing district heating to around 300 customers in Arvika. Heat production consists of a BFB boiler fed with GROT fuel (branches and peaks) and delivers a maximum power of 30 MW. In order to operate the plant, an average of 60 m3 of water per day is consumed from the urban water network. The water consumption is divided between water treatment, sooting and process cooling.

    In the processes, sulfur is dosed to obtain a more complete combustion of the hazardous flue gases that can occur. This is a result of previous thesis made for Arvika fjärrvärme. GROT is a fuel that contains high levels of moisture, which means that a high amount of condensate is formed during combustion, averaging 100 m3 per day. At present, condensate is sufficient to meet the condensate limit values ​​to be flushed into the drain. This is achieved by sand filtration and pH neutralization.

    Today, Arvika heat production is equipped with a purification stage for the feed water consisting of a softening filter and membrane filtration. This creates good conditions for cleaning the condensate and recirculating it in the process. Questions for this study are which hazardous substances the condensate can contain and how the condensate composition affected due to sulfur dosage. In addition, Arvika fjärrvärme wants to find out whether the purified condensate can replace the use of the urban water and, finally, if the condensate can be purified and used as feed water in the process.

    The execution of the work was based on a full-scale attempt in two operating cases of 9 and 18 MW. The tank collecting all condensate after purification in the sand filter and pH neutralization was coupled to the feed water purification stage. Thus, the condensate was pumped and purified in the softening filter and membrane filter. Assay substrates were collected before and after purification of the condensate.

    In addition to the topics that Arvika investigates, high levels of alkalinity were found in the condensate. The sulfur dosage that Arvika technology works with can be the cause of the high concentrations of sulphate. However, it appears that both the sulfate and alkalinity were purified in the membrane filter.

    The amount of condensate formed cannot completely replace the entire water requirement, but definitely large parts. The condensate can be used as feed water based on the retention rate for all substances. However, it appears that two substances, chloride and sulphate can create problems for the membrane filter. To investigate this, the condensate should be tested over a longer period of time to see the affect the chloride as well as the sulphate in the long run.

    Fulltekst (pdf)
    fulltext
  • 252.
    Dahlin, Sandra
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Processteknologi.
    Deactivation of emission control catalysts for heavy-duty vehicles: Impact of biofuel and lube oil-derived contaminants2020Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Catalytic emission control is used to reduce the negative impact of pollutants from diesel exhausts on our health and on the environment. For a heavy-duty truck, such a system consists of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and an ammonia slip catalyst (ASC). Due to greenhouse-gas induced global warming, it is necessary to decrease the emissions of such gases. Two strategies for this reduction are: 1) to produce engines that are more fuel efficient, 2) to use sustainably produced renewable fuels such as biodiesel and HVO. However, both these strategies may pose additional challenges for the emission control system: a colder exhaust due to the higher fuel-efficiency requires the use of highly active catalysts; catalyst deactivation related to impurities in biofuels, which requires very robust catalysts.   The objective of this thesis was to study the impact of biofuel as well as lubrication oil-related contaminants on the performance of emission control catalysts (DOC and SCR catalysts) for heavy-duty diesel engines. The main focus has been on the low-temperature performance of V2O5-WO3/TiO2 (VWTi) and Cu-SSZ-13 SCR catalysts.    Results from the project have shown that both Cu-SSZ-13 and VWTi catalysts capture and can be deactivated by phosphorus (P), while only the Cu-SSZ-13 is deactivated by sulfur (S). The degree of the P-related deactivation depends on the concentration in the catalyst, which depends on content of P in the exhaust and the exposure time, as well as the type of catalyst. S-deactivation of Cu-SSZ-13 is observed at low temperatures, where un-poisoned Cu-SSZ-13 are significantly more active than VWTi catalysts. As a contrast, the VWTi-performance can even be improved by sulfur; but alkali metals are severe poisons to VWTi catalysts. Partial performance-recovery of S-poisoned Cu-SSZ-13 can be obtained by exposing it to sulfur-free exhausts at elevated temperatures. The use of an upstream DOC, providing fast SCR conditions to the SCR catalyst, considerably improves the low-temperature performance of the VWTi, as well as sulfur-poisoned Cu-SSZ-13 catalysts. An upstream DOC also protects the SCR catalysts from phosphorus deactivation, as it can trap large amounts of P. However, if too much phosphorus is captured by the DOC, severe deactivation of this catalyst results, which lowers the overall performance of the exhaust treatment system.  Insights from this project will guide the development of robust exhaust treatment systems for various applications. Additionally, it could aid in developing more durable emission control catalysts.

    Fulltekst (pdf)
    Sandra Dahlin PhD thesis
  • 253.
    Dai, Junxi
    et al.
    Guangzhou Univ, Peoples R China.
    Huang, Zhongyi
    Guangzhou Univ, Peoples R China.
    Zhang, Hongguo
    Guangzhou Univ, Guangzhou Univ Linkoping Univ Res Ctr Urban Sustai, Guangzhou 510006, Peoples R China; Guangzhou Univ, Peoples R China.
    Shi, Huihui
    Guangzhou Univ, Peoples R China.
    Arulmani, Samuel Raj Babu
    Guangzhou Univ, Peoples R China.
    Liu, Xianjie
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Huang, Lei
    Guangzhou Univ, Peoples R China.
    Yan, Jia
    Guangzhou Univ, Peoples R China.
    Xiao, Tangfu
    Guangzhou Univ, Peoples R China.
    Promoted Sb removal with hydrogen production in microbial electrolysis cell by ZIF-67-derived modified sulfate-reducing bacteria bio-cathode2023Inngår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 856, artikkel-id 158839Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Bio-cathode Microbial electrolysis cell (MEC) has been widely discovered for heavy metals removal and hydrogen production. However, low electron transfer efficiency and heavy metal toxicity limit MEC treatment efficiency. In this study, ZIF-67 was introduced to modify Sulfate-reducing bacteria (SRB) bio-cathode to enhance the bioreduction of sulfate and Antimony (Sb) with hydrogen production in the MEC. ZIF-67 modified bio-cathode was developed from a bio-anode microbial fuel cell (MFC) by operating with an applied voltage of 0.8 V to reverse the polarity. Cyclic voltammetry, linear sweep voltammetry and electrochemical impedance were done to confirm the performance of the ZIF67 modified SRB bio-cathode. The synergy reduction of sulfate and Sb was accomplished by sulfide metal precipitation reaction from SRB itself. Maximum sulfate reduction rate approached 93.37 % and Sb removal efficiency could reach 92 %, which relies on the amount of sulfide concentration generated by sulfate reduction reaction, with 0.923 +/- 0.04 m(3) H-2/m(3) of hydrogen before adding Sb and 0.857 m(3) H-2/m(3) of hydrogen after adding Sb. The hydrogen was mainly produced in this system and the result of gas chromatography (GC) indicated that 73.27 % of hydrogen was produced. Meanwhile the precipitates were analyzed by X-ray diffraction and X-ray photoelectron spectroscopy to confirm Sb2S3 was generated from Sb (V).

  • 254.
    Damas, Giane
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Ivashchenko, Dmitri
    Rivalta, Ivan
    Araujo, Carlos Moyses
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Carbon Dioxide  Reduction Mechanism on Ru-based Electrocatalysts: Insights from First-principles TheoryManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Solar fuel production through the so-called artificial photosynthesis has attracted a great deal of attention to the development of a new world energy matrix that is renewable and environmentally friendly. This process basically comprises the absorption of sunlight energy by an appropriate photocatalyst that is active for carbon dioxide conversion into organic fuels. Commonly, an electrocatalyst can be coupled to the system for later improvement of the photocatalytic efficiency and selectivity. In this work, we have undertaken a thorough investigation of the redox reaction mechanism of Ru-based electrocatalysts by means of density functional theory (DFT) methods under the experimental conditions that have been previously reported. More specifically, we have studied the electrochemistry and catalytic activity of the coordination complex [Ru(bpy)2(CO)2]2+. Our theoretical assessment support the following catalytic cycle: (i) [Ru(bpy)2(CO)2]2+ is transformed into [Ru(bpy)2(CO)]0 upon the two-electron reduction and CO release; (ii) [Ru(bpy)2(CO)]0 is protonated to form the hydride complex [Ru(bpy)2(CO)H]+; (iii) CO2 is activated by the hydride complex through an electrophilic addition to form the intermediate [Ru(bpy)2(CO)(OCHO)]+, with the formation of C-H bond; (iv) the resulting formate ligand ion is then released in solution; and, finally, (iv) CO ligand is reattached to the complex to recover the initial complex [Ru(bpy)2(CO)2]2+.  

    Fulltekst (pdf)
    Carbon Dioxide Reduction Mechanism on Ru-based Electrocatalysts
    Fulltekst (pdf)
    Supporting Information
  • 255.
    Damas, Giane
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori. Uppsala Univ, Dept Phys & Astron, Mat Theory Div, Box 530, S-75121 Uppsala, Sweden.;Linköping Univ, Dept Phys Chem & Biol, S-58183 Linköping, Sweden..
    Ivashchenko, Dmytro A.
    Univ Lyon 1, Univ Lyon, Ens Lyon, Lab Chim,UMR 5182,CNRS, Lyon, France..
    Rivalta, Ivan
    Univ Lyon 1, Univ Lyon, Ens Lyon, Lab Chim,UMR 5182,CNRS, Lyon, France.;Univ Bologna, Dipartimento Chim Ind Toso Montanari, Bologna, Italy..
    Araujo, Moyses
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori. Uppsala Univ, Dept Phys & Astron, Mat Theory Div, Box 530, S-75121 Uppsala, Sweden.;Karlstad Univ, Dept Engn & Phys, S-65188 Karlstad, Sweden..
    Carbon dioxide reduction mechanism on Ru-based electrocatalysts [Ru(bpy)(2)(CO)(2)](2+): insights from first-principles theory2021Inngår i: Sustainable Energy & Fuels, E-ISSN 2398-4902, Vol. 5, nr 23, s. 6066-6076Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Solar fuel production through the so-called artificial photosynthesis has attracted a great deal of attention to the development of a new world energy matrix that is renewable and environmentally friendly. This process is characterized by light absorption with enough photon energy to generate conduction electrons, which drive the carbon dioxide reduction to produce organic fuels. It is also common to couple Ru-complex electrocatalysts to form a more efficient and selective hybrid system for this application. In this work, we have undertaken a thorough investigation of the redox reaction mechanism of Ru-based electrocatalysts by means of density functional theory (DFT) methods under the experimental conditions that have been previously reported. More specifically, we have studied the electrochemistry and catalytic activity of the [Ru(bpy)(2)(CO)(2)](2+) coordination complex. Our theoretical assessment supports the following catalytic cycle: (i) [Ru(bpy)(2)(CO)(2)](2+) is transformed into [Ru(bpy)(2)(CO)](0) upon two-electron reduction and CO release; (ii) [Ru(bpy)(2)(CO)](0) is protonated to form the [Ru(bpy)(2)(CO)H](+) hydride complex; (iii) CO2 is activated by the hydride complex through an electrophilic addition to form the [Ru(bpy)(2)(CO)(OCHO)](+) intermediate; (iv) the resulting formic acid ligand is released in solution; and, finally, (v) the CO ligand is reattached to the complex to recover the initial [Ru(bpy)(2)(CO)(2)](2+) catalyst.

    Fulltekst (pdf)
    FULLTEXT01
  • 256.
    Damas, Giane
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    von Kieseritzky, Fredrik
    Arubedo AB.
    Hellberg, Jonas
    Arubedo AB.
    Marchiori, Cleber
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Araujo, Carlos Moyses
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Symmetric Small-Molecules With Acceptor-Donor-Acceptor Architecture for Efficient Visible-Light Driven Hydrogen Production: Optical and Thermodynamic Aspects2019Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, nr 51, s. 30799-30808Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Small-molecules (SM) have attracted a great deal of attention in the field of solar energy conversion due to their unique propertiescompared to polymers, such as well-defined molecular weight and lack of regio-isomeric impurities. Furthermore, these materials can be synthesized in a variety of configurational architectures, representing an opportunity for tailoring chemical and optical properties that could lead to a better photocatalytic efficiency for hydrogen generation. Here, we evaluate by means of density functional theory (DFT) and time-dependent DFT methods a set of small-molecules with A-D-A architecture (A-acceptor; D- donor) based on well-known building blocks like thiophene (T), cyclopentadithiophene (CPT) and benzothiadiazole (BT) as potential candidates for photocatalytic hydrogen evolution reaction (HER). We also propose i) the replacement of the thiophene unit by 3,4-ethylenedioxythiophene (EDOT) to form with CPT unit an extended donor core ii) an additional acceptor unit, the 1,3,4-thiadiazole (Tz), in the extremities and iii) insertion of the difluoromethoxy (DFM) as substituent in the BT unit. Our outcomes reveal that these materials have a broad absorption spectrum with λ= 318-719 nm, being the most intense absorption peak originated from an electronic transition with charge-transfer nature, as the spatial distribution of LUMO is concentrated on the acceptor units for all materials. Moreover, these small-molecules not only present catalytic power or thermodynamic driving force to carry out the chemical reactions involved in the process of hydrogen production, but can be coupled in cooperative photocatalytic systems to promote intramolecular charge transfer that is expected to boost the overall photocatalytic efficiency of these materials.

  • 257.
    Damas, Giane
    et al.
    Uppsala universitet.
    von Kieseritzky, Fredrik
    Arubedo AB.
    Hellberg, Jonas
    Arubedo AB.
    Marchiori, Cleber
    Uppsala universitet.
    Araujo, Carlos Moyses
    Uppsala universitet.
    Symmetric Small-Molecules With Acceptor-Donor-Acceptor Architecture for Efficient Visible-Light Driven Hydrogen Production: Optical and Thermodynamic Aspects2019Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, nr 51, s. 30799-30808Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Small-molecules (SM) have attracted a great deal of attention in the field of solar energy conversion due to their unique propertiescompared to polymers, such as well-defined molecular weight and lack of regio-isomeric impurities. Furthermore, these materials can be synthesized in a variety of configurational architectures, representing an opportunity for tailoring chemical and optical properties that could lead to a better photocatalytic efficiency for hydrogen generation. Here, we evaluate by means of density functional theory (DFT) and time-dependent DFT methods a set of small-molecules with A-D-A architecture (A-acceptor; D- donor) based on well-known building blocks like thiophene (T), cyclopentadithiophene (CPT) and benzothiadiazole (BT) as potential candidates for photocatalytic hydrogen evolution reaction (HER). We also propose i) the replacement of the thiophene unit by 3,4-ethylenedioxythiophene (EDOT) to form with CPT unit an extended donor core ii) an additional acceptor unit, the 1,3,4-thiadiazole (Tz), in the extremities and iii) insertion of the difluoromethoxy (DFM) as substituent in the BT unit. Our outcomes reveal that these materials have a broad absorption spectrum with λ= 318-719 nm, being the most intense absorption peak originated from an electronic transition with charge-transfer nature, as the spatial distribution of LUMO is concentrated on the acceptor units for all materials. Moreover, these small-molecules not only present catalytic power or thermodynamic driving force to carry out the chemical reactions involved in the process of hydrogen production, but can be coupled in cooperative photocatalytic systems to promote intramolecular charge transfer that is expected to boost the overall photocatalytic efficiency of these materials.

  • 258.
    Danielsson, Annie
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Magnesiumrika livsmedel och effekt av dietärt och supplementärt magnesium på muskelstyrka och relativ muskelmassa hos individer över medelåldern2020Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Muskelstyrka och muskelmassa avtar med stigande ålder och är associerat med mortalitet, svaghet, osteoporos, fall och frakturer. Hos yngre individer har magnesiumtillskott signifikant ökat muskelstyrka. Det rekommenderade dagliga intaget (RDI) av magnesium enligt Nordiska näringsrekommendationer (NNR) är lägre än rekommendationen av U.S Food and Nutrition Board (FNB). Syftet med detta litteraturarbete var att studera publicerad litteratur inom ämnet magnesium och muskler med avsikt att undersöka ifall ett ökat magnesiumintag hos individer över medelåldern påverkar muskelstyrka och relativ muskelmassa samt undersöka vilka livsmedel som ur ett ekonomiskt perspektiv kan konsumeras för att bidra till att NNR´s RDI uppnås. Litteratursökning identifierade sex artiklar som var relevanta för frågeställningen ”Kan en högre dos magnesium öka muskelstyrka?”. Samma artiklar användes för ytterligare en frågeställning; ”Kan en högre dos magnesium förbättra relativ muskelmassa?”. Litteratursökning för den andra frågeställningen identifierade inte fler artiklar som var relevanta för frågeställningen. För den tredje frågeställningen ”Vilka livsmedel kan med fördel ur ett ekonomiskt perspektiv bidra till ett högre intag av magnesium?” användes information från Livsmedelsverkets livsmedelsdatabas och medelvärdet av tre livsmedelsbutikers jämförelsepriser. Sammanställningen av den forskning som finns visade att en kost som uppnår NNR´s dagsrekommendation främjar muskelstyrka men det gjorde inte ett högre intag av magnesium via kosttillskott. Ett ökat intag av både dietärt och supplementärt magnesium observerades främja relativ muskelmassa men det verkar som att dietärt magnesium har högre biotillgänglighet än magnesium i kosttillskott. De mest ekonomiska livsmedlen som kan konsumeras för att bidra till en högre dos magnesium i kosten var fullkornsprodukter som frukostflingor, pasta och hårt bröd.

    Fulltekst (pdf)
    fulltext
  • 259.
    Danyliv, Iryna
    et al.
    Lviv Polytech Natl Univ, Ukraine.
    Ivaniuk, Khrystyna
    Lviv Polytech Natl Univ, Ukraine.
    Danyliv, Yan
    Lviv Polytech Natl Univ, Ukraine.
    Helzhynskyy, Igor
    Lviv Polytech Natl Univ, Ukraine.
    Andruleviciene, Viktorija
    Kaunas Univ Technol, Lithuania.
    Volyniuk, Dmytro
    Kaunas Univ Technol, Lithuania.
    Stakhira, Pavlo
    Lviv Polytech Natl Univ, Ukraine.
    Baryshnikov, Glib
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten. Bohdan Khmelnytsky Natl Univ, Ukraine.
    Grazulevicius, Juozas V.
    Kaunas Univ Technol, Lithuania.
    Derivatives of 2-Pyridone Exhibiting Hot-Exciton TADF for Sky-Blue and White OLEDs2023Inngår i: ACS APPLIED ELECTRONIC MATERIALS, ISSN 2637-6113, Vol. 5, nr 8, s. 4174-4186Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Development of emissivematerials for utilization inorganic light-emittingdiodes (OLEDs) remains a highly relevant research field. One of themost important aspects in the development of efficient emitters forOLEDs is the efficiency of triplet-to-singlet exciton conversion.There are many concepts proposed for the transformation of tripletexcitons to singlet excitons, among which thermally activated delayedfluorescence (TADF) is the most efficient and widespread. One of thevariations of the TADF concept is the hot exciton approach accordingto which the process of exciton relaxation into the lowest energyelectronic state (internal conversion as usual) is slower than intersystemcrossing between high-lying singlets and triplets. In this paper,we present the donor-acceptor materials based on 2-pyridoneacceptor coupled to the different donor moieties through the phenyllinker demonstrating good performance as components of sky-blue, green-yellow,and white OLEDs. Despite relatively low photoluminescence quantumyields, the compound containing 9,9-dimethyl-9,10-dihydroacridinedonor demonstrated very good efficiency in sky-blue OLED with thesingle emissive layer, which showed an external quantum efficiency(EQE) of 3.7%. It also forms a green-yellow-emitting exciplex with4,4 & PRIME;,4 & DPRIME;-tris[phenyl(m-tolyl)amino]triphenylamine.The corresponding OLED showed an EQE of 6.9%. The white OLED combiningboth exciplex and single emitter layers demonstrated an EQE of 9.8%together with excellent current and power efficiencies of 16.1 cdA(-1) and 6.9 lm W-1, respectively.Quantum-chemical calculations together with the analysis of photoluminescencedecay curves confirm the ability of all of the studied compounds toexhibit TADF through the hot exciton pathway, but the limiting factorreducing the efficiency of OLEDs is the low photoluminescence quantumyields caused mainly by nonradiative intersystem crossing dominatingover the radiative fluorescence pathway.

    Fulltekst (pdf)
    fulltext
  • 260.
    Das, Biswanath
    et al.
    Univ New South Wales, Sch Chem, Sydney, NSW 2052, Australia.
    Thapper, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Ott, Sascha
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Colbran, Stephen B.
    Univ New South Wales, Sch Chem, Sydney, NSW 2052, Australia.
    Structural features of molecular electrocatalysts in multi-electron redox processes for renewable energy: recent advances2019Inngår i: Sustainable Energy & Fuels, E-ISSN 2398-4902, Vol. 3, nr 9, s. 2159-2175Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Understanding the structural features of molecular electrocatalysts for carbon dioxide reduction and water oxidation is essential for manufacturing next generation catalysts for renewable energy. We will discuss the crucial structural motifs of those catalysts that have shown novel characteristics in recent years in terms of electrocatalytic efficacy (high TON, TOF and low overpotential), product selectivity and mechanisms. Both inorganic and organic homogeneous catalysts are scrutinized in this review. We will also highlight electrocatalysts with dual activity (i.e. they are able to catalyze both water oxidation and CO2 reduction) as an interesting prospect from the point of view of a single catalyst electrolyzer: a possible design for future easy-to-manufacture effective electrolyzers. This discussion will enrich the overall knowledge on the electrocatalyst design, an important step towards the development of efficient catalysts with cutting edge designs for a renewable energy future and practical applications.

  • 261. Davoodi, A
    et al.
    Pan, Jinshan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Norgren, S.
    Integration of scanning electrochemical microscopy and atomic force microscopy for in-situ investigation of localized corrosion2005Inngår i: Proc. 16th International Corrosion Congress, Beijing, Sept. 19-24, 2005, 2005, s. 19-19Konferansepaper (Annet vitenskapelig)
  • 262. Dax, Daniel
    et al.
    Chavez Bastidas, Maria Soledad
    Teixeira Mendonca, Regis
    Sanchez Poblete, Julio Antonio
    Xu, Chunlin
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. Abo Akad Univ, Finland.
    Willfor, Stefan
    Synthesis of novel cationic hydrogels from spruce O-acetyl galactoglucomannan for metal ion removal2014Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, s. 226-CELL-Artikkel i tidsskrift (Annet vitenskapelig)
  • 263.
    Deguchi, Shigeru
    et al.
    Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, Yokosuka 237-0061, Japan.
    Shimoshige, Hirokazu
    Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, Yokosuka 237-0061, Japan.
    Tsudome, Mikiko
    Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, Yokosuka 237-0061, Japan.
    Mukai, Sada-atsu
    Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, Yokosuka 237-0061, Japan.
    Corkery, Robert W.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Ito, Susumu
    Department of Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Nishihra, Okinawa 903-0213, Japan.
    Horikoshi, Koki
    Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, Yokosuka 237-0061, Japan.
    Microbial growth at hyperaccelerations up to 403,627 x g2011Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 108, nr 19, s. 7997-8002Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    It is well known that prokaryotic life can withstand extremes of temperature, pH, pressure, and radiation. Little is known about the proliferation of prokaryotic life under conditions of hyperacceleration attributable to extreme gravity, however. We found that living organisms can be surprisingly proliferative during hyperacceleration. In tests reported here, a variety of microorganisms, including Gram-negative Escherichia coli, Paracoccus denitrificans, and Shewanella amazonensis; Gram-positive Lactobacillus delbrueckii; and eukaryotic Saccharomyces cerevisiae, were cultured while being subjected to hyperaccelerative conditions. We observed and quantified robust cellular growth in these cultures across a wide range of hyperacceleration values. Most notably, the organisms P. denitrificans and E. coli were able to proliferate even at 403,627 × g. Analysis shows that the small size of prokaryotic cells is essential for their proliferation under conditions of hyperacceleration. Our results indicate that microorganisms cannot only survive during hyperacceleration but can display such robust proliferative behavior that the habitability of extraterrestrial environments must not be limited by gravity.

  • 264.
    Delekta, Szymon Sollami
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik, Integrerade komponenter och kretsar.
    Smith, Anderson David
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik.
    Li, Jiantong
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik, Integrerade komponenter och kretsar.
    Östling, Mikael
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik, Integrerade komponenter och kretsar.
    Inkjet printed highly transparent and flexible graphene micro-supercapacitors2017Inngår i: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, nr 21, s. 6998-7005Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Modern energy storage devices for portable and wearable technologies must fulfill a number of requirements, such as small size, flexibility, thinness, reliability, transparency, manufacturing simplicity and performance, in order to be competitive in an ever expanding market. To this end, a comprehensive inkjet printing process is developed for the scalable and low-cost fabrication of transparent and flexible micro-supercapacitors. These solid-state devices, with printed thin films of graphene flakes as interdigitated electrodes, exhibit excellent performance versus transparency (ranging from a single-electrode areal capacitance of 16 mu F cm(-2) at transmittance of 90% to a capacitance of 99 mu F cm(-2) at transmittance of 71%). Also, transparent and flexible devices are fabricated, showing negligible capacitance degradation during bending. The ease of manufacturing coupled with their great capacitive properties opens up new potential applications for energy storage devices ranging from portable solar cells to wearable sensors.

  • 265. Devesse, Laurence
    et al.
    Smirnova, Irina
    Lönneborg, Rosa
    Stockholm University, Sweden.
    Kapp, Ulrike
    Brzezinski, Peter
    Leonard, Gordon A.
    Dian, Cyril
    Crystal structures of DntR inducer binding domains in complex with salicylate offer insights into the activation of LysR-type transcriptional regulators2011Inngår i: Molecular Microbiology, ISSN 0950-382X, E-ISSN 1365-2958, Vol. 81, nr 2, s. 354-367Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Activation of LysR-type transcription factors (LTTRs) is thought to result from conformational changes that occur when inducer molecules bind to their Inducer Binding Domains (IBDs). However, the exact nature of these changes remains to be fully elucidated. We present the crystal structures of two truncated constructs of the LTTR DntR in their apo-forms and in complex with its natural inducer molecule, salicylate. These provide a fuller picture of the conformational changes that can occur in LTTR IBDs and offer insights that may be relevant when considering the mechanism of activation of LTTRs. Two of the crystal structures show that DntR IBDs can bind up to two inducer molecules. The full extent of conformational changes observed is achieved only when inducer molecules are bound in both binding sites identified. Point mutations disrupting the putative secondary binding site produce DntR variants with a reduced response to salicylate in a whole cell system, suggesting that this site is functionally relevant.

  • 266.
    Dey, Subhamoy
    et al.
    Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India.
    Guchhait, Kartik Chandra
    Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India.
    Jana, Debarati
    Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India.
    Majumder, Suparna
    Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India.
    Patra, Anuttam
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Panda, Amiya Kumar
    Department of Chemistry, Vidyasagar University, Midnapore, West Bengal, India; Sadhu Ram Chand Murmu University of Jhargram, Jhargram, West Bengal, India.
    Ghosh, Chandradipa
    Department of Human Physiology, Vidyasagar University, Midnapore, West Bengal, India.
    Biosynthesis of Lantibiotics2023Inngår i: Lantibiotics as Alternative Therapeutics / [ed] Sanket Joshi, Rajiv Kar, Dibyajit Lahiri, Moupriya Nag, Academic Press, 2023, 1, s. 43-63Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    In the last few decades, the prevalence of multidrug resistance and importunate virulence in bacteria emerged as one of the serious concerns in health-care system. Lantibiotics, the well-conserved antimicrobial peptides predominantly rich in atypical sulfur-containing amino acids, lanthionine (Lan), and 3-methyl-lanthionine (MeLan), synthesized ribosomally from bacterial cells and modified posttranslationally, have drawn considerable interest in the therapeutic management of infectious diseases because of their effectiveness against multidrug-resistant bacteria. So far studied, the other reasons remain their potency, broad-spectrum nature, and negligible cytotoxicity. The biosynthesis of the lantibiotics involves two major steps, the modification of precursor peptides and their proteolytic activation. The gene cluster constituting the biosynthetic machinery codes essentially for the prepeptide and modification enzymes besides the proteases, ATP-binding cassette transporters, immunity factors, and regulatory proteins required as accessory factors. Herein, in this chapter a comprehensive discussion has been made on the biosynthesis of lantibiotics, which may be noteworthy in biomedical science for technology advancement.

  • 267.
    Diaz-Morales, Oscar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Impurity as a virtue2020Inngår i: NATURE ENERGY, ISSN 2058-7546, Vol. 5, nr 3, s. 193-194Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Understanding the activity and stability of oxygen-evolving anodes is crucial for developing better water splitting electrolysers. Researchers now show the importance of interactions between iron and hydr(oxy)oxide hosts in dynamically-stable electrocatalysts that balance dissolution and deposition of iron present in the electrolyte.

  • 268.
    Dickhut, Rebecca
    et al.
    Virginia Institute for Marine Science, USA.
    Cincinelli, Alessandra
    Università degli Studi di Firenze, Italien.
    Cochran, Michel
    Virginia Institute for Marine Science, USA.
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Aerosol-Mediated Transport and Deposition of Brominated Diphenyl Ethers to Antarctica2012Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, nr 6, s. 3135-3140Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Brominated diphenyl ethers (BDE47, 99, 100, and 209) were measured in air, snow and sea ice throughout western Antarctica between 2001 and 2007. BDEs in Antarctic air were predominantly associated with aerosols and were low compared to those in remote regions of the northern hemisphere, except in Marguerite Bay following the fire at Rothera research station in Sept 2001, indicating that this event was a local source of BDE209 to the Antarctic environment. Aerosol BDE47/100 reflects a mixture of commercial pentaBDE products; however, BDE99/100 is suggestive of photodegradation of BDE99 during long-range atmospheric transport (LRAT) in the austral summer. BDEs in snow were lower than predicted based on snow scavenging of aerosols indicating that atmospheric deposition events may be episodic. BDE47, -99, and -100 significantly declined in Antarctic sea ice between 2001 and 2007; however, BDE209 did not decline in Antarctic sea ice over the same time period. Significant losses of BDE99 and -100 from sea ice were recorded over a 19 day period in spring 2001 demonstrating that seasonal ice processes result in the preferential loss of some BDEs. BDE47/100 and BDE99/100 in sea ice samples reflect commercial pentaBDE products, suggesting that photodegradation of BDE99 is minimal during LRAT in the austral winter.

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  • 269. Diment, Daryna
    et al.
    Tkachenko, Oleg
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för materialvetenskap, Nanoteknologi och funktionella material.
    Schlee, Philipp
    Kohlhuber, Nadine
    Potthast, Antje
    Budnyak, Tetyana M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för materialvetenskap, Nanoteknologi och funktionella material.
    Rigo, Davide
    Balakshin, Mikhail
    Study toward a More Reliable Approach to Elucidate the Lignin Structure–Property–Performance Correlation2024Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 25, nr 1, s. 200-212Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The correlation between lignin structure, its properties, and performance is crucial for lignin engineering in high-value products. Currently, a widespread approach is to compare lignins which differ by more than one parameter (i.e., Kraft vs organosolv vs lignosulfonates) in various applications by attributing the changes in their properties/performance specifically to a certain variable (i.e., phenolic −OH groups). Herein, we suggest a novel approach to overcome this issue by changing only one variable at a time while keeping all others constant before investigating the lignin properties/performance. Indulin AT (Ind-AT), a softwood Kraft lignin, was chosen as the model substrate for this study. Selective (analytical) lignin modifications were used to mask/convert specific functionalities, such as aliphatic (AliphOH) including benzylic −OH (BenzOH) and phenolic −OH (PhOH) groups, carboxyl groups (−COOH) and carbonyl groups (CO) via methylation, acetylation, and reduction. The selectivity and completeness of the reactions were verified by comprehensive NMR analysis (31P and 2D HSQC) of the modified preparations together with state-of-the-art molar mass (MM) characterization. Methylene blue (MB) adsorption, antioxidant activity, and glass transition temperature (Tg) were used to demonstrate and compare the properties/performance of the obtained modified lignins. We found that the contribution of different functionalities in the adsorption of MB follows the trend BenzOH > −COOH > AlipOH > PhOH. Noteworthy, benzylic −OH contributes ca. 3 and 2.3 times more than phenolic and aliphatic −OH, respectively. An 11% and 17% increase of Tg was observed with respect to the unmodified Indulin by methylating benzylic −OH groups and through reduction, respectively, while full acetylation/methylation of aliphatic and phenolic −OH groups resulted in lower Tg. nRSI experiments revealed that phenolic −OH play a crucial role in increasing the antioxidant activity of lignin, while both aliphatic −OH groups and −COOHs possess a detrimental effect, most likely due to H-bonding. Overall, for the first time, we provide here a reliable approach for the engineering of lignin-based products in high value applications by disclosing the role of specific lignin functionalities.

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  • 270. Ding, Xin
    et al.
    Gao, Yan
    Zhang, Linlin
    Yu, Ze
    Liu, Jianhui
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Artificial photosynthesis: A two-electrode photoelectrochemical cell for light driven water oxidation with molecular components2014Inngår i: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 149, s. 337-340Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An efficient two-electrode molecular PEC was assembled, in which a photoanode was constructed using a co-adsorbed method with a molecular photosensitizer (PS) 1 and a molecular catalyst 2 on TiO2-sintered FTO electrode (TiO2(1 + 2)). Without applied bias against a reference electrode, the system achieves remarkable photocurrent densities and carries out light driven water oxidation as evidenced by Clark electrode measurements in solution. A photocurrent density of 70 mA/cm(2) has been obtained within 10 s illumination time, and a TON of about 220 was obtained with a maximum turnover frequency (TOF) of ca. 4 min(-1) within the initial 5 minutes illumination duration.

  • 271. Dingemans, Milou M L
    et al.
    de Groot, Aart
    van Kleef, Regina G D M
    Bergman, Åke
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK), Avdelningen för miljökemi.
    van den Berg, Martin
    Vijverberg, Henk P M
    Westerink, Remco H S
    Hydroxylation increases the neurotoxic potential of BDE-47 to affect exocytosis and calcium homeostasis in PC12 cells.2008Inngår i: Journal of Environmental Health Perspectives, ISSN 0091-6765, E-ISSN 1552-9924, Vol. 116, nr 5, s. 637-43Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Oxidative metabolism, resulting in the formation of hydroxylated polybrominated diphenyl ether (PBDE) metabolites, may enhance the neurotoxic potential of brominated flame retardants. OBJECTIVE: Our objective was to investigate the effects of a hydroxylated metabolite of 2,2',4,4'-tetra-bromodiphenyl ether (BDE-47; 6-OH-BDE-47) on changes in the intracellular Ca2+ concentration ([Ca2+]i) and vesicular catecholamine release in PC12 cells. METHODS: We measured vesicular catecholamine release and [Ca2+]i using amperometry and imaging of the fluorescent Ca2+-sensitive dye Fura-2, respectively. RESULTS: Acute exposure of PC12 cells to 6-OH-BDE-47 (5 microM) induced vesicular catecholamine release. Catecholamine release coincided with a transient increase in [Ca2+]i, which was observed shortly after the onset of exposure to 6-OH-BDE-47 (120 microM). An additional late increase in [Ca2+]i was often observed at > or =1 microM 6-OH-BDE-47. The initial transient increase was absent in cells exposed to the parent compound BDE-47, whereas the late increase was observed only at 20 microM. Using the mitochondrial uncoupler carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP) and thapsigargin to empty intracellular Ca2+ stores, we found that the initial increase originates from emptying of the endoplasmic reticulum and consequent influx of extracellular Ca2+, whereas the late increase originates primarily from mitochondria. CONCLUSION: The hydroxylated metabolite 6-OH-BDE-47 is more potent in disturbing Ca2+ homeostasis and neurotransmitter release than the parent compound BDE-47. The present findings indicate that bioactivation by oxidative metabolism adds considerably to the neurotoxic potential of PBDEs. Additionally, based on the observed mechanism of action, a cumulative neurotoxic effect of PBDEs and ortho-substituted polychlorinated biphenyls on [Ca2+]i cannot be ruled out.

  • 272.
    Dobrota, Ana S.
    et al.
    Univ Belgrade, Fac Phys Chem, Belgrade 11158, Serbia..
    Pasti, Igor A.
    Univ Belgrade, Fac Phys Chem, Belgrade 11158, Serbia..
    Skorodumova, Natalia V.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori. KTH Royal Inst Technol, Sch Ind Engn & Management, Dept Mat Sci & Engn, Multiscale Mat Modelling Grp, S-10044 Stockholm, Sweden.;Uppsala Univ, Dept Phys & Astron, S-75120 Uppsala, Sweden..
    Oxidized graphene as an electrode material for rechargeable metal-ion batteries - a DFT point of view2015Inngår i: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 176, s. 1092-1099Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In line with a growing interest in the use of graphene-based materials for energy storage applications and active research in the field of rechargeable metal-ion batteries we have performed a DFT based computational study of alkali metal atoms (Li, Na and K) interaction with an oxidized graphene. The presence of oxygen surface groups (epoxy and hydroxyl) alters the chemisorption properties of graphene. In particular, we observe that the epoxy groups are redox active and enhance the alkali metal adsorption energies by a factor of 2 or more. When an alkali metal atom interacts with hydroxyl-graphene the formation of metal-hydroxide is observed. In addition to a potential boost of metal ion storage capability, oxygen functional groups also prevent the precipitation of the metal phase. By simulating lithiation/de-lithiation process on epoxy-graphenes, it was concluded that the oxidized graphene can undergo structural changes during battery operation. Our results suggest that the content and the type of oxygen surface groups should be carefully tailored to maximize the performance of metal-ion batteries. This is mainly related to the control of the oxidation level in order to provide enough active centers for metal ion storage while preserving sufficient electrical conductivity.

  • 273.
    Doe, Maofeng
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Flerskalig materialmodellering.
    Persson, Clas
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Flerskalig materialmodellering. Department of Physics, University of Oslo, Norway .
    Analysis of the Semi local States in ZnO-InN Compounds2014Inngår i: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 14, nr 10, s. 4937-4943Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    ZnO alloys are extensively explored for the developments of optoelectronics. In this work we analyze the rather unconventional type of ZnO-based compound ZnOX (ZnO)(1y)Xy with X = InN. The compound forms alloy with ZnO and/or assembles cluster structures in the ZnO host. Importantly, this type of alloy benefits from being isovalent which implies a more stable crystalline structure, and at the same time it benefits from the oxynitride anion-alloying that alters the optoelectronic properties. Theoretical studies reveal that incorporating InN in ZnO strongly narrows the fundamental band gap energy Eg. For example, the (ZnO)(0.875)(InN)(0.125) alloy has the gap energy E-g = 2.20 eV = E-g(ZnO) 1.14 eV. The origin of this effect is a hybridization of the anion N 2p-like and O 2p-like orbitals. Intriguingly, the presence of InN nanoclusters enhances this effect and narrows the gap further, and moreover, the nanostructured configurations show more disperse energy distribution of the hybridized anion states compared with the random alloy. Nanoclustering affects the ZnO host more compared to structures with more random distribution of the InN dimers. On the basis of the different characters of the alloys and the nanostructures, we conclude that fine-tuned synthesizing of the (ZnO)(1-y)(InN)(y) alloys can be beneficial for a variety of novel nanosystems for optoelectronic and photoelectrochemical applications.

  • 274.
    dos Reis, Glaydson Simões
    et al.
    Department of Forest Biomaterials and Technology, Biomass Technology Centre, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Larsson, Sylvia H.
    Department of Forest Biomaterials and Technology, Biomass Technology Centre, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Mathieu, Manon
    IMT Mines Albi-Carmaux, Albi, France.
    Thyrel, Mikael
    Department of Forest Biomaterials and Technology, Biomass Technology Centre, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Ngoc Pham, Tung
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. The University of Da-Nang, University of Science and Technology, Da Nang, Vietnam.
    Application of design of experiments (DoE) for optimised production of micro- and mesoporous Norway spruce bark activated carbons2023Inngår i: Biomass Conversion and Biorefinery, ISSN 2190-6815, E-ISSN 2190-6823, Vol. 13, nr 11, s. 10113-10131Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work, Norway spruce (Picea abies (Karst) L.) bark was employed as a precursor to prepare activated carbon using zinc chloride (ZnCl2) as a chemical activator. The purpose of this study was to determine optimal activated carbon (AC) preparation variables by the response surface methodology using a Box–Behnken design (BBD) to obtain AC with high specific surface area (SBET), mesopore surface area (SMESO), and micropore surface area (SMICR). Variables and levels used in the design were pyrolysis temperature (700, 800, and 900 °C), holding time (1, 2, and 3 h), and bark/ZnCl2 impregnation ratio (1, 1.5, and 2). The optimal conditions for achieving the highest SBET were as follows: a pyrolysis temperature of 700 °C, a holding time of 1 h, and a spruce bark/ZnCl2 ratio of 1.5, which yielded an SBET value of 1374 m2 g−1. For maximised mesopore area, the optimal condition was at a pyrolysis temperature of 700 °C, a holding time of 2 h, and a bark/ZnCl2 ratio of 2, which yielded a SMESO area of 1311 m2 g−1, where mesopores (SMESO%) comprised 97.4% of total SBET. Correspondingly, for micropore formation, the highest micropore area was found at a pyrolysis temperature of 800 °C, a holding time of 3 h, and a bark/ZnCl2 ratio of 2, corresponding to 1117 m2 g−1, with 94.3% of the total SBET consisting of micropores (SMICRO%). The bark/ZnCl2 ratio and pyrolysis temperature had the strongest impact on the SBET, while the interaction between temperature and bark/ZnCl2 ratio was the most significant factor for SMESO. For the SMICRO, holding time was the most important factor. In general, the spruce bark AC showed predominantly mesoporous structures. All activated carbons had high carbon and low ash contents. Chemical characterisation indicated that the ACs presented disordered carbon structures with oxygen functional groups on the ACs’ surfaces. Well-developed porosity and a large surface area combined with favourable chemical composition render the activated carbons from Norway spruce bark with interesting physicochemical properties. The ACs were successfully tested to adsorb sodium diclofenac from aqueous solutions showing to be attractive products to use as adsorbents to tackle polluted waters. Graphical abstract: [Figure not available: see fulltext.].

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  • 275.
    Dracheva, Elena
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Norinder, Ulf
    Department of Computer and Systems Sciences, Stockholm University, Kista, Sweden.
    Rydén, Patrik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för matematik och matematisk statistik.
    Engelhardt, Josefin
    Department of Environmental Science, Stockholm University, Stockholm, Sweden.
    Weiss, Jana M.
    Department of Environmental Science, Stockholm University, Stockholm, Sweden.
    Andersson, Patrik L.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    In Silico Identification of Potential Thyroid Hormone System Disruptors among Chemicals in Human Serum and Chemicals with a High Exposure Index2022Inngår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 56, nr 12, s. 8363-8372Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Data on toxic effects are at large missing the prevailing understanding of the risks of industrial chemicals. Thyroid hormone (TH) system disruption includes interferences of the life cycle of the thyroid hormones and may occur in various organs. In the current study, high-throughput screening data available for 14 putative molecular initiating events of adverse outcome pathways, related to disruption of the TH system, were used to develop 19 in silico models for identification of potential thyroid hormone system-disrupting chemicals. The conformal prediction framework with the underlying Random Forest was used as a wrapper for the models allowing for setting the desired confidence level and controlling the error rate of predictions. The trained models were then applied to two different databases: (i) an in-house database comprising xenobiotics identified in human blood and ii) currently used chemicals registered in the Swedish Product Register, which have been predicted to have a high exposure index to consumers. The application of these models showed that among currently used chemicals, fewer were overall predicted as active compared to chemicals identified in human blood. Chemicals of specific concern for TH disruption were identified from both databases based on their predicted activity.

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  • 276. Duan, Dongban
    et al.
    Han, Yi
    Tu, Zhiyu
    Guo, Haoxuan
    Zhang, Zizhu
    Shi, Yaxin
    Li, Jiyuan
    Sun, Qi
    Chen, Junyi
    Li, Zhu
    Liu, Tong
    Cui, Daqing
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK). China Institute of Atomic Energy, China.
    Liu, Zhibo
    Gadolinium Neutron Capture Reaction-Induced Nucleodynamic Therapy Potentiates Antitumor Immunity2023Inngår i: CCS Chemistry, ISSN 2096-5745, Vol. 5, nr 11, s. 2589-2602Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A nuclear reaction-induced dynamic therapy, denoted as nucleodynamic therapy (NDT), has been invented that triggers immunogenic cell death and successfully treats metastatic tumors due to its unexpected abscopal effect. Gadolinium neutron capture therapy (GdNCT) is binary radiotherapy based on a localized nuclear reaction that produces high-energy radiations (e.g., Auger electrons, γ-rays, etc.) in cancer cells when 157Gd is irradiated with thermal neutrons. Yet, its clinical application has been postponed due to the poor ability of Auger electrons and γ-rays to kill cells. Here, we engineered a 157Gd-porphyrin framework that synergizes GdNCT and dynamic therapy to efficiently produce both •OH and immunogenic 1O2 in cancer cells, thereby provoking a strong antitumor immune response. This study unveils the fact and mechanism that NDT heats tumor immunity. Another unexpected finding is that the Auger electron can be the most effective energy-transfer medium for radiation-induced activation of nanomedicines because its nanoscale trajectory perfectly matches the size of nanomaterials. In mouse tumor models, NDT causes nearly complete regression of both primary and distant tumor grafts. Thus, this 157Gd-porphyrin framework radioenhancer endows GdNCT with the exotic function of triggering dynamic therapy; its application may expand in clinics as a new radiotherapy modality that utilizes GdNCT to provoke whole-body antitumor immune response for treating metastases, which are responsible for 90% of all cancer deaths. 

  • 277. Duan, Sai
    et al.
    Xu, Xin
    Luo, Yi
    Hermansson, Kersti
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Tian, Zhong-Qun
    Thermal effects on electronic properties of CO/Pt(111) in water2013Inngår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 15, nr 32, s. 13619-13627Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Structure and adsorption energy of carbon monoxide molecules adsorbed on the Pt(111) surfaces with various CO coverages in water as well as work function of the whole systems at room temperature of 298 K were studied by means of a hybrid method that combines classical molecular dynamics and density functional theory. We found that when the coverage of CO is around half monolayer, i.e. 50%, there is no obvious peak of the oxygen density profile appearing in the first water layer. This result reveals that, in this case, the external force applied to water molecules from the CO/Pt(111) surface almost vanishes as a result of the competitive adsorption between CO and water molecules on the Pt(111) surface. This coverage is also the critical point of the wetting/non-wetting conditions for the CO/Pt(111) surface. Averaged work function and adsorption energy from current simulations are consistent with those of previous studies, which show that thermal average is required for direct comparisons between theoretical predictions and experimental measurements. Meanwhile, the statistical behaviors of work function and adsorption energy at room temperature have also been calculated. The standard errors of the calculated work function for the water-CO/Pt(111) interfaces are around 0.6 eV at all CO coverages, while the standard error decreases from 1.29 to 0.05 eV as the CO coverage increases from 4% to 100% for the calculated adsorption energy. Moreover, the critical points for these electronic properties are the same as those for the wetting/non-wetting conditions. These findings provide a better understanding about the interfacial structure under specific adsorption conditions, which can have important applications on the structure of electric double layers and therefore offer a useful perspective for the design of the electrochemical catalysts.

  • 278.
    Dubocq, Florian
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Optimizing nontarget workflows for identification of organic contaminants in various matrices2020Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Since year 2000, production of chemicals around the world has more than doubled. Chemicals are used in many and diverse applications in our everyday life and even if their properties are useful, some can have a negative impact on environment and humans. It is thus important to monitor these chemicals to better understand their impact on the environment and human health.

    In this thesis, nontarget analysis (NTA) was used to detect and identify organic compounds in various environmental and health relevant matrices such as fish, indoor dust, aqueous film-forming foams (AFFFs) and fire emissions. The aim was to optimize the workflow by extracting relevant chemical information from the analysed matrix and mitigate bias in reported results. Tests were thus performed to optimize sample preparation for fish and dust samples as well as processing data from high-resolution mass spectrometry analysis of dust, AFFFs and fire emissions.

    Statistical analysis such as analysis of variance (ANOVA) with the help of hierarchical cluster analysis (HCA) enabled the detection of outliers in dust, AFFFs, and gas and soot from fire emissions. Mass defect (MD) plot analysis further enabled the detection of various relevant compounds according to their functional groups and structural properties. The nontarget analysis workflow was supported by target and suspect screening analysis to confirm the efficiency of the optimized overall workflow. Various classes of compounds could be detected and tentatively identified such as flame retardants, liquid crystal monomers or bisphenols in dust samples, organofluorine and fluorine-free surfactants in AFFFs, and flame retardants and hydrocarbons in gas and soot samples .Quality controls were also performed to assess the performance of the optimized workflow.

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  • 279.
    Dubocq, Florian
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bæringsdóttir, Bergdís Björk
    Örebro University, Örebro, Sweden.
    Wang, Thanh
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kärrman, Anna
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Comparing extraction methods for comprehensive screening of organic micropollutants in fish using gas chromatography coupled to high-resolution mass spectrometryManuskript (preprint) (Annet vitenskapelig)
  • 280.
    Dubocq, Florian
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kärrman, Anna
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Gustavsson, Jakob
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Wang, Thanh
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Comprehensive chemical characterization of indoor dust by target, suspect screening and nontarget analysis using liquid chromatography and gas chromatography coupled with high resolution mass spectrometryManuskript (preprint) (Annet vitenskapelig)
  • 281. Duch, J.
    et al.
    Kubisiak, P.
    Adolfsson, Karin H.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Golda-Cepa, M.
    Kotarba, A.
    Work function modifications of graphite surface via oxygen plasma treatment2017Inngår i: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 419, s. 439-446Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The surface modification of graphite by oxygen plasma was investigated experimentally (X-ray diffraction, nanoparticle tracking analysis, laser desorption ionization mass spectrometry, thermogravimetry, water contact angle) and by molecular modelling (Density Functional Theory). Generation of surface functional groups (mainly –OHsurf) leads to substantial changes in electrodonor properties and wettability gauged by work function and water contact angle, respectively. The invoked modifications were analyzed in terms of Helmholtz model taking into account the theoretically determined surface dipole moment of graphite—OHsurf system (μ = 2.71 D) and experimentally measured work function increase (from 0.75 to 1.02 eV) to determine the –OH surface coverage (from 0.70 to 1.03 × 1014 groups cm−2). Since the plasma treatment was confined to the surface, the high thermal stability of the graphite material was preserved as revealed by the thermogravimetric analysis. The obtained results provide a suitable quantitative background for tuning the key operating parameters of carbon electrodes: electronic properties, interaction with water and thermal stability.

  • 282.
    Duner, Gunnar
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Iruthayaraj, Joseph
    Daasbjerg, Kim
    Pedersen, Steen Uttrup
    Thormann, Esben
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Dédinaité, Andra
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Attractive double-layer forces and charge regulation upon interaction between electrografted amine layers and silica2012Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 385, s. 225-234Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Amine functionalities have been introduced on glassy carbon surfaces through electrografting of 4-(2-aminoethyl)benzenediazonium tetrafluoroborate. The grafted layers were characterized by ellipsometry and by nanomechanical mapping in air and aqueous solutions using the atomic force microscopy Peak-Force QNM mode. The layer was found to be 2.5 nm thick with low roughness, comparable to that of the glassy carbon substrate. However, small semi-spherical features were observed in the topographical image, indicating a clustering of the grafted amine compound. The nanomechanical mapping also demonstrated some swelling of the layer in water and pointed toward an important contribution of electrostatic interactions for the tip-surface adhesion. The forces between an aminated glassy carbon surface and a mu m-sized silica particle in aqueous solutions were measured at different ionic strength and pH-values. The results demonstrate that an attractive double-layer force predominates at large separations, and that the surface charge densities increase as the separation between the surfaces decreases. The degree of charge regulation on the aminated glassy carbon is significant. The relatively low surface charge density of the aminated glassy carbon is attributed to significant incorporation of counterions in the water-rich grafted layer.

  • 283. Durmus, Z.
    et al.
    Baykal, A.
    Sozeri, H.
    Toprak, Muhammet S.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Materialfysik, Funktionella material, FNM.
    Preparation of PVP (Polyvinyl Pyrrolidone)/Ba-Sr hexaferrites via gel to crystalline method2012Inngår i: Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry, ISSN 1553-3174, Vol. 42, nr 10, s. 1390-1397Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ba-M- and Sr-M-type hexagonal ferrites have been prepared via a sol-gel route, and the effects of adding different amounts of polyvinyl pyrrolidone (PVP) into the sol solutions. The average crystallite, size, D and σ, was obtained as for Z13 = 22 ± 2 nm and Z13-2 = 16 ± 3 nm and for Z16 = 18 ± 7 nm and Z16-2 = 17 ± 5 nm by XRD. FT-IR and TG analysis were used to prove the presence of PVP on BaFe12O19 and SrFe12O19. Based on the TGA curves the mass losses of the samples are assessed as follows: Z13 ̃15%, Z13-2 ̃25%, Z16 ̃5%, and Z16-2 ̃10%.

  • 284.
    Díaz-Cruz, José Manuel
    et al.
    Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, E08028, Barcelona, Spain Water Research Institute (IdRA) of the University of Barcelona, Barcelona, Spain.
    Serrano, Nuria
    Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, E08028, Barcelona, Spain Water Research Institute (IdRA) of the University of Barcelona, Barcelona, Spain.
    Pérez Ràfols, Clara
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi. Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, E08028, Barcelona, Spain.
    Ariño, Cristina
    Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, E08028, Barcelona, Spain Water Research Institute (IdRA) of the University of Barcelona, Barcelona, Spain.
    Esteban, Miquel
    Department of Chemical Engineering and Analytical Chemistry, University of Barcelona, Martí i Franquès 1-11, E08028, Barcelona, Spain Water Research Institute (IdRA) of the University of Barcelona, Barcelona, Spain.
    Electroanalysis from the past to the twenty-first century: challenges and perspectives2020Inngår i: Journal of Solid State Electrochemistry, ISSN 1432-8488, E-ISSN 1433-0768, Vol. 24, nr 11-12, s. 2653-2661Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A personal mini-review is presented on the history of electroanalysis and on their present achievements and future challenges. The manuscript is written from the subjective view of two generations of electroanalytical chemists that have witnessed for many years the evolution of this discipline.

  • 285.
    Dürr, Robin N.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi. Université Paris-Saclay.
    Process for preparing a membrane electrode assembly2021Patent (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    Processes for manufacturing membrane electrode assemblies for use in electrochemical cells are disclosed. The processes comprise the steps of: depositing a layer of a liquid composition capable of being solidified by freezing onto an electrode, cooling the electrode with the deposited layer of liquid composition to a temperature at or below the freezing temperature of the liquid composition thereby forming an electrode coated with a solidified layer of theliquid composition, arranging the electrode on a surface of a membrane, and heating the electrode and membrane arrangement for a pre-determined period of time wherein the heating is done above the freezing temperature of the liquid composition and preferably not higher than a glass transition temperature of the membrane.

    Fulltekst (pdf)
    fulltext
  • 286. Ecco, L. G.
    et al.
    Li, Jing
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Fedel, M.
    Deflorian, F.
    Pan, Jinshan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    EIS and in situ AFM study of barrier property and stability of waterborne and solventborne clear coats2014Inngår i: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 77, nr 3, s. 600-608Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Various processes can occur when paints are in contact with moisture, such as ingress of water and aggressive ions into the coating. As a consequence, the microstructure and properties of the paints can be affected. The present study combines electrochemical impedance spectroscopy (EIS) and in situ atomic force microscopy (AFM) to investigate the barrier property of waterborne and solventborne coatings on mild steel, paying particular attention to the occurrences in the first 24 h after contact between the coating surface and electrolyte. The sequential in situ AFM images revealed that changes on the order of hundreds of nanometres at the coating surface have occurred shortly after the exposure to the electrolytes. EIS observations for the clear waterborne alkyd coating revealed a rise in the |Z|0.015Hz and a decrease in the coating capacitance after a few hours of exposure. Evidences that water uptake caused swelling of the coating and promoted the closure/blockage of pores were given by means of in situ AFM. The solventborne alkyd emulsion has demonstrated lower reactivity to the presence of the electrolyte and a correlation between the coating resistance and defects/pores evolution is suggested.

  • 287.
    Edberg, Alexandra
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    Monitoring Kraft Recovery Boiler Fouling by Multivariate Data Analysis2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This work deals with fouling in the recovery boiler at Montes del Plata, Uruguay. Multivariate data analysis has been used to analyze the large amount of data that was available in order to investigate how different parameters affect the fouling problems. Principal Component Analysis (PCA) and Partial Least Square Projection (PLS) have in this work been used. PCA has been used to compare average values between time periods with high and low fouling problems while PLS has been used to study the correlation structures between the variables and consequently give an indication of which parameters that might be changed to improve the availability of the boiler. The results show that this recovery boiler tends to have problems with fouling that might depend on the distribution of air, the black liquor pressure or the dry solid content of the black liquor. The results also show that multivariate data analysis is a powerful tool for analyzing these types of fouling problems. 

    Fulltekst (pdf)
    fulltext
  • 288.
    Edlund, Ulrica
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Albertsson, Ann-Christine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Hemicellulose-rich materials derived from wood pre-hydrolysis2014Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, s. 199-CELL-Artikkel i tidsskrift (Annet vitenskapelig)
  • 289.
    Ehlin, Sarah
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Hur påverkar lösligt β-glukan GI-värdet?: Analys av vetebaserat bröd2020Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The work was done in collaboration with Lantmännen's research foundation to produce a new and health-promoting bread. The dietary fiber beta-glucan was added to bread at a sufficiently high content to have positive health effects on blood cholesterol and blood sugar levels. The bread should also have a high sensory quality. In this project the effects of addition of beta-glucan on the theoretical GI (glycemic index) and GL (glycemic load) were investigated. An in vitro analysis was used, and the GL was calculated from the GI. These analyses were carried out on both freeze-dried bread and fresh bread containing different concentrations of beta-glucan. A sensory analysis was also done to see if there was any difference between the control bread and the bread containing the beta-glucan. The purpose of the work was to investigate how the theoretical GI value and the theoretical GL value are affected by two different preparations of beta-glucan (with concentration of 32% respectively 75% beta-glucan) in bread with end concentrations of 0.2 and 2.0 % beta-glucan of the total quantity of flour. The result indicates that there is significant effect on GI and GL of beta-glucan in wheat-based bread. Between the reference bread and the 0.2% bread of the freeze-dried bread, a significant difference was seen with a p-value of 0.048 in a paired t-test. It also was a significant difference between the reference bread and the 2.0% bread with a pvalue of 0.014 in a paired t-test. The GI values were calculated to 65 and 63 respectively for 0.2 and 2.0% beta glucan for the freeze-dried bread. The GI value for the fresh bread were calculated to 68 and 52 respectively for 0.2 and 2.0% beta glucan. The GL-values for the fresh-bread were calculated to 79 and 60 respectively for 0.2 and 2.0% beta glucan. The GL-values for the freeze-dried bread were calculated to 38 and 37 respectively for 0.2 and 2.0% beta glucan. A significant difference was seen between the reference bread and thefresh bread containing 2% added betaglucan (p-value = 0.002using t-test). The fresh bread with 0.2% added betaglucan had at about the same GI value as the reference bread and a significant difference could not be seen (p = 0.7642).

    In other studies, whole grain flour and a dietary fiber content of 15-45 g / serving have been shown to have an effect on the GI and GL values. The desired result is to have attenuated effects on blood sugar levels in the blood after food intake and thus be able to achieve prerequisites for blood sugar claims. To achieve the desired effect a whole-wheat flour should be used to raise the dietary fiber content and reduce the proportion of wheat flour and glucose available.

    Fulltekst (pdf)
    Hur påverkar lösligt β-glukan GI-värdet?
  • 290.
    Ejaz, Syeda Abida
    et al.
    Islamia Univ Bahawalpur, Pakistan.
    Aziz, Mubashir
    Islamia Univ Bahawalpur, Pakistan.
    Ahmed, Aftab
    Islamia Univ Bahawalpur, Pakistan.
    Alotaibi, Saqer S. S.
    Taif Univ, Saudi Arabia.
    Albogami, Sarah M. M.
    Taif Univ, Saudi Arabia.
    Siddique, Farhan
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten. Bahauddian Zakariya Univ, Pakistan.
    Batiha, Gaber El-Saber
    Damanhour Univ, Egypt.
    New Insight into the Pharmacological Importance of Atropine as the Potential Inhibitor of AKR1B1 via Detailed Computational Investigations: DFTs, ADMET, Molecular Docking, and Molecular Dynamics Studies2023Inngår i: Applied Biochemistry and Biotechnology, ISSN 0273-2289, E-ISSN 1559-0291, Vol. 195, nr 8, s. 5136-5157Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this research is to investigate the quantum geometric properties and chemical reactivity of atropine, a pharmaceutically active tropane alkaloid. Using density functional theory (DFT) computations with the B3LYP/SVP functional theory basis set, the most stable geometry of atropine was determined. Additionally, a variety of energetic molecular parameters were calculated, such as the optimized energy, atomic charges, dipole moment, frontier molecular orbital energies, HOMO-LUMO energy gap, molecular electrostatic potential, chemical reactivity descriptors, and molecular polarizability. To determine atropines inhibitory potential, molecular docking was used to analyze ligand interactions within the active pockets of aldo-keto reductase (AKR1B1 and AKR1B10). The results of these studies showed that atropine has greater inhibitory action against AKR1B1 than AKR1B10, which was further validated through molecular dynamic simulations by analyzing root mean square deviation (RMSD) and root mean square fluctuations (RMSF). The results of the molecular docking simulation were supplemented with simulation data, and the ADMET characteristics were also determined to predict the drug likeness of a potential compound. In conclusion, the research suggests that atropine has potential as an inhibitor of AKR1B1 and could be used as a parent compound for the synthesis of more potent leads for the treatment of colon cancer associated with the sudden expression of AKR1B1.

  • 291.
    Ejenstam, Lina
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Polymer och fiber. KTH Royal Institute of Technology, Sweden.
    Swerin, Agne
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik. KTH Royal Institute of Technology, Sweden.
    Claesson, Per M.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik. KTH Royal Institute of Technology, Sweden.
    Toward superhydrophobic polydimethylsiloxane−silica particle coatings2016Inngår i: Journal of Dispersion Science and Technology, ISSN 0193-2691, E-ISSN 1532-2351, Vol. 37, nr 9, s. 1375-1383Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hydrophobized silica nanoparticles of different sizes, from 16 to 500 nm, were used to impart roughness to a hydrophobic polydimethylsiloxane (PDMS) coating with the aim of obtaining superhydrophobic properties. The particle silanization process and the curing process of the PDMS coating were optimized to increase the contact angle (CA) of the particle containing coating. The evaluation of the coatings, by means of water CA measurements and scanning electron microscopy imaging, shows that superhydrophobicity in the adhesive rose state was achieved using combinations of two differently sized particles, with an excess of the small 16 nm ones. Superhydrophobicity in the lotus state was obtained when the filler concentration of 16 nm particles was 40 wt%, but under such conditions the coating was found to partially crack, which is detrimental in barrier applications. The preference for the rose wetting state can be explained by the round shape of the particles, which promotes the superhydrophobic rose wetting state over that of the superhydrophobic lotus state.

  • 292.
    Ejenstam, Lina
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap. SP Technical Research Institute of Sweden.
    Swerin, Agne
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap. SP Technical Research Institute of Sweden.
    Claesson, Per M.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap. SP Technical Research Institute of Sweden.
    Towards superhydrophobic polydimethylsiloxane-silica particle coatings2016Inngår i: Journal of Dispersion Science and Technology, ISSN 0193-2691, E-ISSN 1532-2351, Vol. 37, nr 9, s. 1375-1383Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hydrophobized silica nanoparticles of different sizes, from 16 to 500 nm, were used to impart roughness to a hydrophobic polydimethylsiloxane (PDMS) coating with the aim of obtaining superhydrophobic properties. The particle silanization process and the curing process of the PDMS coating were optimized to increase the contact angle of the particle containing coating. The evaluation of the coatings, by means of water contact angle measurements and scanning electron microscopy imaging, show that superhydrophobicity in the adhesive rose state was achieved using combinations of two differently sized particles, with an excess of the small 16 nm ones. Superhydrophobicity in the Lotus state was obtained when the filler concentration of 16 nm particles was 40 wt%, but under such conditions the coating was found to partially crack, which is detrimental in barrier applications. The preference for the rose wetting state can be explained by the round shape of the particles, which promotes the superhydrophobic rose wetting state over that of the superhydrophobic Lotus state.

  • 293. Eketjäll, Susanna
    et al.
    Jeppsson, Fredrik
    CNS and Pain iMed, AstraZeneca, Södertälje, Sweden; Operations Global Quality, AstraZeneca, Södertälje, Sweden.
    Cebers, Gvido
    AZD3293: A Novel, Orally Active BACE1 Inhibitor with High Potency and Permeability and Markedly Slow Off-Rate Kinetics2016Inngår i: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 50, nr 4, s. 1109-1123Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A growing body of pathological, biomarker, genetic, and mechanistic data suggests that amyloid accumulation, as a result of changes in production, processing, and/or clearance of brain amyloid-beta peptide (A beta) concentrations, plays a key role in the pathogenesis of Alzheimer's disease (AD). Beta-secretase 1 (BACE1) mediates the first step in the processing of amyloid-beta protein precursor (A beta PP) to A beta peptides, with the soluble N terminal fragment of A beta PP (sA beta PP beta) as a direct product, and BACE1 inhibition is an attractive target for therapeutic intervention to reduce the production of A beta. Here, we report the in vitro and in vivo pharmacological profile of AZD3293, a potent, highly permeable, orally active, blood-brain barrier (BBB) penetrating, BACE1 inhibitor with unique slow off-rate kinetics. The in vitro potency of AZD3293 was demonstrated in several cellular models, including primary cortical neurons. In vivo in mice, guinea pigs, and dogs, AZD3293 displayed significant dose-and time-dependent reductions in plasma, cerebrospinal fluid, and brain concentrations of A beta(40), A beta(42), and sA beta PP beta. The in vitro potency of AZD3293 in mouse and guinea pig primary cortical neuronal cells was correlated to the in vivo potency expressed as free AZD3293 concentrations in mouse and guinea pig brains. In mice and dogs, the slow off-rate from BACE1 may have translated into a prolongation of the observed effect beyond the turnover rate of A beta. The preclinical data strongly support the clinical development of AZD3293, and patients with AD are currently being recruited into a combined Phase 2/3 study to test the disease-modifying properties of AZD3293.

  • 294. Eketjäll, Susanna
    et al.
    Jeppsson, Fredrik
    Innovative Medicines AstraZeneca, CNS & Pain, Södertälje, Sweden.
    Fälting, Johanna
    AZ-4217: A High Potency BACE Inhibitor Displaying Acute Central Efficacy in Different In Vivo Models and Reduced Amyloid Deposition in Tg2576 Mice2013Inngår i: Journal of Neuroscience, ISSN 0270-6474, E-ISSN 1529-2401, Vol. 33, nr 24, s. 10075-10084Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A beta, the product of APP (amyloid precursor protein), has been implicated in the pathophysiology of Alzheimer's disease (AD). beta-Site APP cleaving enzyme1 (BACE1) is the enzyme initiating the processing of the APP to A beta peptides. Small molecule BACE1 inhibitors are expected to decrease A beta-peptide generation and thereby reduce amyloid plaque formation in the brain, a neuropathological hallmark of AD. BACE1 inhibition thus addresses a key mechanism in AD and its potential as a therapeutic target is currently being addressed in clinical studies. Here, we report the discovery and the pharmacokinetic and pharmacodynamic properties of BACE1 inhibitor AZ-4217, a high potency compound (IC50 160 pM in human SH-SY5Y cells) with an excellent in vivo efficacy. Central efficacy of BACE1 inhibition was observed after a single dose in C57BL/6 mice, guinea pigs, and in an APP transgenic mouse model of cerebral amyloidosis (Tg2576). Furthermore, we demonstrate that in a 1 month treatment paradigm BACE1 inhibition of A beta production does lower amyloid deposition in 12-month-old Tg2576 mice. These results strongly support BACE1 inhibition as concretely impacting amyloid deposition and therefore potentially an important approach for therapeutic intervention in AD.

  • 295.
    Ekner, Holly
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Dreij, Kristian
    Sadiktsis, Ioannis
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Determination of polycyclic aromatic hydrocarbons in commercial olive oils by HPLC/GC/MS – Occurrence, composition and sources2022Inngår i: Food Control, ISSN 0956-7135, E-ISSN 1873-7129, Vol. 132, artikkel-id 108528Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Polycyclic aromatic hydrocarbons (PAHs) are a large class of organic compounds produced from incomplete combustion. Many PAHs are mutagenic and some are carcinogenic and pose a health risk to humans. Dietary intake of PAHs is a major route of exposure, where fats and edible oils are important contributors to overall dietary PAH exposure. Composed of hundreds of individual compounds as a complex mixture, only 16 PAHs are typically monitored in food and the environment.

    In this present study we analyzed 16 commercial olive oil samples from different countries of origin and type (virgin or refined oil) for their content of 45 PAHs using a high-performance liquid chromatograph coupled to a gas chromatograph with a mass spectrometric detector. The content of the 45 PAHs varied between 9.17–94.7 μg/kg (median: 30.1 μg/kg) in the different olive oil samples. Only one sample didn't meet the regulatory threshold levels for PAHs.

    The compositional profile of PAHs across the olive oil samples showed a high abundance of PAHs of lower molecular weights, and a large contribution of alkylated PAHs regardless of olive oil type. Direct contact with diesel exhaust emissions from mechanical harvesters has previously shown to affect PAH levels in olive oils. Using diagnostic PAH ratios, biomass/coal combustion and/or petroleum/fossil fuel combustion were indicated as important sources. Source apportionment by positive matrix factorization revealed diesel exhaust emission and biomass combustion as the two major sources of PAHs followed by traffic emissions. This suggests that air quality may have a considerable impact on pollution levels in olive oils and thus indirectly affect dietary exposure.

  • 296. Ekvall, Mikael T.
    et al.
    Hedberg, Jonas
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Wallinder, Inger Odnevall
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Hansson, Lars-Anders
    Cedervall, Tommy
    Long-term effects of tungsten carbide (WC) nanoparticles in pelagic and benthic aquatic ecosystems2018Inngår i: Nanotoxicology, ISSN 1743-5390, E-ISSN 1743-5404, Vol. 12, nr 1, s. 79-89Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    As the production and usage of nanomaterials are increasing so are the concerns related to the release of the material into nature. Tungsten carbide (WC) is widely used for its hard metal properties, although its use, in for instance tyre studs, may result in nano-sized particles ending up in nature. Here, we evaluate the potential long-term exposure effects of WC nanoparticles on a pelagic (Daphnia magna) and a benthic (Asellus aquaticus) organism. No long-term effects were observed in the benthic system with respect to population dynamics or ecosystem services. However, long-term exposure of D. magna resulted in increased time to first reproduction and, if the particles were resuspended, strong effects on survival and reproductive output. Hence, the considerable differences in acute vs. long-term exposure studies revealed here emphasize the need for more long-term studies if we are to understand the effects of nanoparticles in natural systems.

  • 297.
    EL Andaloussi, Samir
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi.
    Lehto, Taavi
    Laboratory of Molecular Biotechnology, Institute of Technology, Tartu University, Tartu, Estonia.
    Lundin, Per
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi.
    Langel, Ülo
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi.
    Application of PepFect peptides for the delivery of splice-correcting oligonucleotides2011Inngår i: Cell-penetrating peptides: Methods and Protocols, New York: Humana Press, 2011, s. 361-373Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    One oligonucleotide-based approach that appear very promising for the treatment of different genetic disorders are based on so-called splice-correcting oligonucleotides (SCOs) that are exploited to manipulate splicing patterns. In order to increase the bioavailability, cell-penetrating peptides (CPPs) have readily been covalently conjugated to SCOs to facilitate cellular internalization. While being a successful strategy for the delivery of uncharged oligonucleotides (ONs), it is extremely difficult to generate covalent conjugates between commonly used negatively charged ON analogs and cationic CPPs. Furthermore, high concentrations of ONs in the micromolar range are often needed to obtain biological responses, most likely as a result of endosomal entrapment of material. Therefore, exploring other vectorization methods using CPPs with endosomolytic properties are highly desired. A method of using stearyl modified CPP (i.e., TP10) analogs, named PepFect3 and PepFect4, are being described for the transfection of antisense SCOs using a simple one-step co-incubation procedure. These peptides form complexes with SCOs and efficiently promote cellular uptake by facilitating endosomal escape. This chapter describes the methods of how to form and characterize these nanoparticles and the cellular assay used to address the delivery.

  • 298.
    EL Andaloussi, Samir
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi.
    Said Hassane, Fatouma
    Université Montpellier, Motpellier, France.
    Boisguerin, Prisca
    Université Montpellier, Motpellier, France.
    Sillard, Rannar
    University of Tartu, Institute of Technology, Tartu, Estonia.
    Langel, Ülo
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för neurokemi.
    Lebleu, Bernard
    Université Montpellier, Motpellier, France.
    Cell-penetrating peptides-based strategies for the delivery of splice redirecting antisense oligonucleotides2011Inngår i: Therapeutic Oligonucleotides: Methods and Protocols / [ed] John Goodchild, New York: Humana Press, 2011, s. 75-89Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Progress in our understanding of the molecular pathogenesis of human malignancies has provided therapeutic targets amenable to oligonucleotide (ON)-based strategies. Antisense ON-mediated splicing regulation in particular offers promising prospects since the majority of human genes undergo alternative splicing and since splicing defects have been found in many diseases. However, their implementation has been hampered so far by the poor bioavailability of nucleic acids-based drugs. Cell-penetrating peptides (CPPs) now appear as promising non-viral delivery vector for non-permeant biomolecules. We describe here new CPPs allowing the delivery of splice redirecting steric-block ON using either chemical conjugation or non-covalent complexation. We also describe a convenient and robust splice redirecting assay which allows the quantitative assessment of ON nuclear delivery.

  • 299. Elbourne, Aaron
    et al.
    Sweeney, James
    Webber, Grant B.
    Wanless, Erica J.
    Warr, Gregory G.
    Rutland, Mark W.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Atkin, Rob
    Adsorbed and near-surface structure of ionic liquids determines nanoscale friction2013Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 49, nr 60, s. 6797-6799Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Surface-adsorbed and near-surface ion layer structure controls nanotribology in the silica-propylammonium nitrate (PAN)-mica system. Atomic Force Microscopy (AFM) imaging and normal force curves reveal that the normal load dictates the number of interfacial ion layers and the lateral layer structure. Shear force measurements show the lubricity of the interface changes with the number, and lateral structure, of the confined ion layer(s).

  • 300.
    Elmgren, Maja
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Fysikalisk kemi.
    Ho, Felix M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Åkesson, Eva
    Uppsala universitet, Universitetsförvaltningen.
    Schmid, Siegbert
    University of Sydney, School of Chemistry.
    Towns, Marcy
    Purdue University, Department of Chemistry.
    Comparison and Evaluation of Learning Outcomes from an International Perspective: Development of a Best-Practice Process2015Inngår i: Journal of Chemical Education, ISSN 0021-9584, E-ISSN 1938-1328, Vol. 92, nr 3, s. 427-432Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Chemistry education focused on learning outcomes is increasingly practiced, providing new opportunities for international comparisons. The interest in intended learning outcomes and constructive alignment has grown in many parts of the world due to both research in higher education and political decisions. In an International Union of Pure and Applied Chemistry (IUPAC) project, we have developed a method of using critical evaluation of learning outcomes and descriptors at international, national, and institutional levels to enhance learner-centered chemistry education. This method is process-focused, aimed at learning by sharing and comparing practices around the world. Three overarching documents for the chemistry bachelor from the USA, Europe and Australia were compared. The differences were found to be more in style than in content. A tool for self-analysis was constructed to evaluate how learning outcomes for courses and modules are linked to each other and to learning outcomes for educational programs and how the expected learning outcomes can be aligned with learning activities and assessment. We conclude that the method can be used to elucidate the correspondence between learning outcomes at different levels, and the constructive alignment between learning outcomes, learning activities and assessment. The process gives new perspectives and shared knowledge. Chemistry education may need to be different depending on local considerations, and awareness of these differences is of value for further development.

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