| 37141. |
- Momeni, Naghi, et al.
(författare)
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A novel blood-based biomarker for detection of autism spectrum disorders
- 2012
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Ingår i: Translational Psychiatry. - : Nature Publishing Group. - 2158-3188. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Autism Spectrum Disorders (ASD) are classified as neurological developmental disorders. Several studies have been carried out to find a candidate biomarker linked to development of these disorders, but up to date no reliable biomarker is available. Mass spectrometry techniques have been used for protein profiling of blood plasma of children with such disorders in order to identify proteins/peptides which may be used as biomarkers for detection of the disorders. Three differentially expressed peptides with mass charged (m/z) values of 2,020 ± 1, 1,864 ± 1, and 1,978 ± 1 Da in heparin plasma of children with ASD which were significantly changed as compared to the peptide pattern of the non-ASD control group are reported here. This novel set of biomarkers allows for a reliable blood based diagnostic tool that may be used in diagnosis and potentially, in prognosis of ASD.
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| 37142. |
- Momenzadeh, H., et al.
(författare)
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Reactive dye removal from wastewater using a chitosan nanodispersion
- 2011
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Ingår i: Desalination. - : Elsevier BV. - 0011-9164. ; 271:0011-9164, s. 225-230
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Tidskriftsartikel (refereegranskat)abstract
- Adsorption of an azo reactive dye, C.I. Reactive Red 120 (RR120), from aqueous solution on chitosan and on a chitosan nanodispersion has been studied. The nanodispersion was prepared using a mixture of chitosan and sodium tripolyphosphate. The results showed that the adsorption of RR120 on dissolved chitosan and on the chitosan nanodispersion was affected significantly by initial dye concentration, sorbent amount, temperature, pH and ionic strength of the solution. Maximum dye removal for both adsorbents was at a pH of 4-5 and the adsorption of the reactive dye on both dissolved chitosan and the nanodispersion gave good fit to the Langmuir isotherm model. The adsorption capacity of the nanodispersion was around 910mgg-1, much higher than of dissolved chitosan, which was 51mgg-1. The adsorption of the dye on the chitosan nanodispersion reached equilibrium much faster than on dissolved chitosan. The kinetics of the adsorption correlated well with the pseudo-second order model.
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| 37143. |
- Mondal, Arobendo, et al.
(författare)
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Large-Scale Computation of Nuclear Magnetic Resonance Shifts for Paramagnetic Solids Using CP2K
- 2018
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Ingår i: Journal of Chemical Theory and Computation. - : American Chemical Society (ACS). - 1549-9618 .- 1549-9626. ; 14:1, s. 377-394
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Tidskriftsartikel (refereegranskat)abstract
- Large-scale computations of nuclear magnetic resonance (NMR) shifts for extended paramagnetic solids (pNMR) are reported using the highly efficient Gaussian-augmented plane-wave implementation of the CP2K code. Combining hyperfine couplings obtained with hybrid functionals with g-tensors and orbital shieldings computed using gradient-corrected functionals, contact, pseudocontact, and orbital-shift contributions to pNMR shifts are accessible. Due to the efficient and highly parallel performance of CP2K, a wide variety of materials with large unit cells can be studied with extended Gaussian basis sets. Validation of various approaches for the different contributions to pNMR shifts is done first for molecules in a large supercell in comparison with typical quantum-chemical codes. This is then extended to a detailed study of g-tensors for extended solid transition-metal fluorides and for a series of complex lithium vanadium phosphates. Finally, lithium pNMR shifts are computed for Li3V2(PO4)(3), for which detailed experimental data are available. This has allowed an in-depth study of different approaches (e.g., full periodic versus incremental cluster computations of g-tensors and different functionals and basis sets for hyperfine computations) as well as a thorough analysis of the different contributions to the pNMR shifts. This study paves the way for a more-widespread computational treatment of NMR shifts for paramagnetic materials.
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| 37144. |
- Mone, Mariza, 1992
(författare)
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Colors of Life and Optoelectronics: Zinc Porphyrins for Light-Emitting Electrochemical Cells and Organic Photodetectors
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The field of organic optoelectronics constitutes an interdisciplinary field that covers chemistry, physics, materials science and biology. The technological promises of the organic materials over their inorganic counterparts include a lower production cost and the feasibility to be processed through solution-based techniques on large-area and/or flexible substrates. Among organic optoelectronic devices, two technologies are discussed in this thesis. Those are light emitting electrochemical cells (LECs) and photomultiplication (PM) type organic photodetectors (OPDs). The LEC is a light emitting technology that has attracted a lot of scientific interest due to its simple device architecture and fabrication. A category of LECs that is of high interest, are those LECs consisting of materials emitting near-infrared (NIR) light. This specific field is highly alluring, due to the unique applications NIR light can generate in a wide range of fields from medicine to optical communications. However, organic NIR emitters are inherently of lower efficiency when compared to other wavelengths, thus posing a challenge in material design. Hereof, an attempt was made in the context of this work to design and synthesize emitters that will produce light in the deep NIR region and in a functional LEC. The problem of high aggregation of NIR emitters was tackled by blending with appropriate host materials. On the other side, PM type OPDs aim in sensing and not in the production of light. The characteristic of this special category of OPDs is the possibility of enhancing the received weak signal without the need of external components in the device, like photomultiplier tubes. However, since this specific field is not mature yet, there is not adequate knowledge in material design. Thus, there is a need in discovering the materials that will lead to photomultiplication enabling the construction of more efficient devices in the future. In order to achieve all the accomplishments that will be discussed in this thesis, there was a category of molecules that was the heart of all studies. These molecules, often called as colors of life, due to their importance in many processes occurring in nature were porphyrins. Porphyrins are highly versatile motifs and were the tools that led both into production of deep NIR light but also into improving the detection of weak light.
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| 37145. |
- Mongkolpichayarak, Isara, et al.
(författare)
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Cr/MCM-22 catalyst for the synthesis of levulinic acid from green hydrothermolysis of renewable biomass resources
- 2022
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Ingår i: Journal of Catalysis. - : Elsevier BV. - 0021-9517 .- 1090-2694. ; 405, s. 373-384
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Tidskriftsartikel (refereegranskat)abstract
- The novel Cr-loaded MCM-22 zeolite (Cr/MCM-22) was successfully synthesized, fully characterized, and applied as a heterogeneous catalyst for the transformation of biomass-derived materials (glucose, sucrose, cellulose, starch, agricultural residues, and other municipal wastes) into levulinic acid via hydrothermolysis. The novel Cr/MCM-22 gives higher yields of levulinic acid compared to other reported catalysts. Specifically, Cr/MCM-22 produced 73.2% levulinic acid yield from glucose at relatively high concentrations (solvent:biomass 20:1). For starting materials with higher structural complexity, pretreatment was required to maintain a high yield of levulinic acid. The novel catalyst was studied and compared to other related catalysts. The high efficiency is attributed to the synergistic effect induced by confinement control of the microporous material as well as Lewis and Brønsted acid sites of Cr/MCM-22. A reaction mechanism including all reaction steps has been proposed. The Cr/MCM-22 was successfully recycled three times.
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| 37146. |
- Montanari, Celine, et al.
(författare)
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Transparent Wood for Thermal Energy Storage and Reversible Optical Transmittance
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 11:22, s. 20465-20472
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Tidskriftsartikel (refereegranskat)abstract
- Functional load-bearing materials based on phase-change materials (PCMs) are under rapid development for thermal energy storage (TES) applications. Mesoporous structures are ideal carriers for PCMs and guarantee shape stability during the thermal cycle. In this study, we introduce transparent wood (TW) as a TES system. A shape-stabilized PCM based on polyethylene glycol is encapsulated into a delignified wood substrate, and the TW obtained is fully characterized; also in terms of nano- and mesoscale structures. Transparent wood for thermal energy storage (TW-TES) combines large latent heat (similar to 76 J g(-1)) with switchable optical transparency. During the heating process, optical transmittance increases by 6% and reaches 68% for 1.5 mm thick TW-TES. Characterization of the thermal energy regulation performance shows that the prepared TW-TES composite is superior to normal glass because of the combination of good heat-storage and thermal insulation properties. This makes TW-TES composites interesting candidates for applications in energy-saving buildings.
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| 37147. |
- Montañez, Maria I., et al.
(författare)
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Bifunctional Dendronized Cellulose Surfaces as Biosensors
- 2011
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 12:6, s. 2114-2125
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Tidskriftsartikel (refereegranskat)abstract
- Well-defined dendronized cellulose substrates displaying multiple representations of dual-functionality were constructed by taking advantage of the efficiency of the click reaction combined with traditional anhydride chemistry. First, activated cellulose surfaces were decorated with several generations of dendrons, and their peripheral reactive groups were subsequently reacted with a trifunctional orthogonal monomer. The generated substrate tool box was successfully explored by accurately tuning the surface function using a versatile orthogonal dual postfunctionalization approach. In general, the reactions were monitored by using a click-dye reagent or a quartz crystal microbalance (QCM) technique, and the resulting surfaces were well-characterized using XPS, and contact angle measurements. Utilizing this approach two different surfaces have been obtained; that is, triethylenglycol oligomers and amoxicillin molecules were efficiently introduced to the dendritic surface. As a second example, mannose-decorated hydroxyl functional surfaces illustrated their potential as biosensors by multivalent detection of lectin protein at concentration as low as 5 nM.
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| 37148. |
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| 37149. |
- Montesinos-Magraner, Marc, et al.
(författare)
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General Cyclopropane Assembly by Enantioselective Transfer of a Redox-Active Carbene to Aliphatic Olefins
- 2019
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 58:18, s. 5930-5935
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Tidskriftsartikel (refereegranskat)abstract
- Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates, and reagents, even when targeting similar compounds. This approach slows down discovery and limits available chemical space. Introduced herein is a practical and versatile diazocompound and its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. The redox-active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect allowed the asymmetric cyclopropanation of various olefins, including unfunctionalized aliphatic alkenes, that enables the three-step total synthesis of (-)-dictyoptereneA. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally differentiated diazocompounds are viable and advantageous equivalents of single-carbon chirons.
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| 37150. |
- Monti, Susanna, et al.
(författare)
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Characterization of the adsorption dynamics of trisodium citrate on gold in water solution
- 2017
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Ingår i: RSC Advances. - : ROYAL SOC CHEMISTRY. - 2046-2069. ; 7:78, s. 49655-49663
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Tidskriftsartikel (refereegranskat)abstract
- Molecular dynamics simulations (MDs) based on a reactive force field (ReaxFF) are carried out to investigate typical adsorption modes of trisodium citrate (CIT) on gold nanoparticles (AuNPs). All possible configurations of CIT on a model AuNP in solution are identified and the stabilizing role played by the adsorbate on the AuNP structure is disclosed by analyzing protonation state, dynamics and interactions of the molecules with the surrounding environment. A realistic scenario is created by sampling extensively the conformational space of citrate and by validating the simulation results against data extracted from the literature. Carboxyl moieties are found in contact with the gold substrate through one or both oxygens and Na+ ions are present in the adsorbed citrate layer. Citrate binding is relatively strong and its action as a chelator stabilizes surface reconstructions. The molecules have the tendency to self-assemble and form a stable cover, which is reinforced by adatoms. All the results are in perfect agreement with experimental observations and theoretical data.
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