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排序方式: 共有422条查询结果,搜索用时 171 毫秒
1.
Dr. Vinod Khatri Dr. Badri Parshad Prof. Ashok K. Prasad Dr. Sumati Bhatia 《European journal of organic chemistry》2023,26(9):e202201360
In the last decades, various efforts have been made to synthesize optimal glycotripods for targeting trimeric glycoproteins like asialoglycoprotein receptor, hemagglutinin, and langerin. All these trimeric glycoproteins have sugar binding pockets which are highly selective for a particular carbohydrate ligand. Optimized glycotripods are high affinity binders and have been used for delivering drugs or even applied as drug candidates. The selection of the tripodal base scaffold together with the length and flexibility of the linker between the scaffold and sugar residue, as important design parameters are discussed in this review. 相似文献
2.
Bruno Voigt Twinkle Bhatia Julia Hesselbarth Dr. Monika Baumann Prof. Dr. Carla Schmidt Dr. Maria Ott Prof. Dr. Jochen Balbach 《Chemphyschem》2023,24(19):e202300439
Nucleation and growth of amyloid fibrils were found to only occur in supersaturated solutions above a critical concentration (ccrit). The biophysical meaning of ccrit remained mostly obscure, since typical low values of ccrit in the sub-μM range hamper investigations of potential oligomeric states and their structure. Here, we investigate the parathyroid hormone PTH84 as an example of a functional amyloid fibril forming peptide with a comparably high ccrit of 67±21 μM. We describe a complex concentration dependent prenucleation ensemble of oligomers of different sizes and secondary structure compositions and highlight the occurrence of a trimer and tetramer at ccrit as possible precursors for primary fibril nucleation. Furthermore, the soluble state found in equilibrium with fibrils adopts to the prenucleation state present at ccrit. Our study sheds light onto early events of amyloid formation directly related to the critical concentration and underlines oligomer formation as a key feature of fibril nucleation. Our results contribute to a deeper understanding of the determinants of supersaturated peptide solutions. In the current study we present a biophysical approach to investigate ccrit of amyloid fibril formation of PTH84 in terms of secondary structure, cluster size and residue resolved intermolecular interactions during oligomer formation. Throughout the investigated range of concentrations (1 μM to 500 μM) we found different states of oligomerization with varying ability to contribute to primary fibril nucleation and with a concentration dependent equilibrium. In this context, we identified the previously described ccrit of PTH84 to mark a minimum concentration for the formation of homo-trimers/tetramers. These investigations allowed us to characterize molecular interactions of various oligomeric states that are further converted into elongation competent fibril nuclei during the lag phase of a functional amyloid forming peptide. 相似文献
3.
Dr. Mostakim SK Dr. Soumitra Barman Shounik Paul Ratnadip De Dr. S. S. Sreejith Dr. Helge Reinsch Dr. Maciej Grzywa Dr. Norbert Stock Prof. Dr. Dirk Volkmer Dr. Shyam Biswas Prof. Dr. Soumyajit Roy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(12):4098-4107
A Zr-based metal-organic framework has been synthesized and employed as a catalyst for photochemical carbon dioxide reduction coupled with water oxidation. The catalyst shows significant carbon dioxide reduction property with concomitant water oxidation. The catalyst has broad visible light as well as UV light absorption property, which is further confirmed from electronic absorption spectroscopy. Formic acid was the only reduced product from carbon dioxide with a turn-over frequency (TOF) of 0.69 h−1 in addition to oxygen, which was produced with a TOF of 0.54 h−1. No external photosensitizer is used and the ligand itself acts as the light harvester. The efficient and selective photochemical carbon dioxide reduction to formic acid with concomitant water oxidation using Zr-based MOF as catalyst is thus demonstrated here. 相似文献
4.
Erika Fiset Jun-Seok Bae Thomas E Rufford Suresh Bhatia Gao Qing Lu Denisa Hulicova-Jurcakova 《Journal of Solid State Electrochemistry》2014,18(3):703-711
High surface area silicon carbide-derived carbons (Si-CDCs) synthesized by chlorination of beta silicon carbide (βSiC) with two different particle sizes (6 μm and 50 nm) show different porosities with graphitic structure. Transmission electron microscopy, Raman spectroscopy and argon (Ar) and carbon dioxide (CO2) sorption analyses are used to examine the textural properties of the Si-CDCs. The results show that the particle size of the precursor affects the surface area and porosity of carbons. Furthermore, an additional heat treatment of the Si-CDC with 50-nm particle size for 24 h at 1,000 °C results in a collapse of the pore structure and reduces the surface area. The capacitive behaviours are investigated in H2SO4 and in tetraethyl ammonium tetrafluoroborate (TEABF4)/acetonitrile (AN). The electrochemical performance of the Si-CDCs is influenced by the particle size, surface area, pore volume and pore size distribution. The Si-CDCs exhibit capacitances in 1 M H2SO4 of up to 179 F g?1 and very stable charge–discharge performance over 5,000 cycles. This study shows the crucial importance of ultramicropores less than 1 nm combined with nanosized particles for achieving high capacitance in aqueous electrolyte. Moreover, the graphitic degree at the surface of the Si-CDCs enhances considerably the rate capability and stability in both electrolytes. 相似文献
5.
6.
Yunusa Umar Sahar Abdalla SK Manirul Haque Guillermo Salgado Moran Abdurrahman Ishaq Wilson Cardona Villada Jorge Dagnino Leone Marta Bunster 《中国化学会会志》2020,67(1):62-71
The optimized molecular structures, harmonic vibrational wavenumbers, and the corresponding vibrational assignments of (1S,2S)-tramadol and (1R,2R)-tramadol are computationally examined using the B3LYP density functional theory method together with the standard 6–311++G(d,p) and def2-TVZP basis sets. The optimized structures show that phenolic rings of both 1R,2R and 1S,2S tramadol adopt planar geometry, which are slightly distorted due to the substitution at the meta-position; and the six-membered cyclohexane adopts a slightly distorted chair conformation. The 1S,2S enantiomer is energetically more favorable than 1R,2R with the energy differences of 1.32 and 1.03 kcal/mol obtained at B3LYP/6–311++G(d,p) and B3LYP/Def2-TVZP levels, respectively. The analysis of the binding pocket in the silico molecular docking with the m-opioid receptor shows that it originated two clusters with the 1S,2S enantiomer and one cluster with the 1R,2R enantiomer of tramadol. The results point to a more stable complex of the m-opioid receptor with the 1R,2R enantiomer of tramadol. 相似文献
7.
Salwa Meredith Hashim Abdul Rahman Mohamed Subhash Bhatia 《Journal of Sol-Gel Science and Technology》2011,59(3):505-512
Perovskite-type La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF6428) thin-film membrane prepared by modified Pechini sol–gel process, was successfully deposited on porous support
of similar composition using dip-coating method. Fine grain and crack-free film with perovskite structure was obtained at
sintering temperature of 800 °C and dwelling time of 60 min. The cross-sectional image indicated that LSCF6428 thin-film membrane
coated on the porous support showed excellent adhesion to the support with uniform thickness. The minimum dense layer thickness
obtained by dip-coating method was around 0.5 μm. It was found that the oxygen permeability of the supported thin film was
lower than that of the perovskite support, which indicated that the pores of the support were reduced by thin-film deposition
on the support surface. The reduction in the pore size led to the more selective permeation mechanism contributes to the overall
permeation. Successful deposition of LSCF6428 thin-film membrane on porous support can be considered as a promising technique
for the preparation of oxygen separation membrane. 相似文献
8.
Laura Sinatra Jan J. Bandolik Dr. Martin Roatsch Melf Sönnichsen Dr. Clara T. Schoeder Dr. Alexandra Hamacher Andrea Schöler Prof. Dr. Arndt Borkhardt Prof. Dr. Jens Meiler Dr. Sanil Bhatia Prof. Dr. Matthias U. Kassack Prof. Dr. Finn K. Hansen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(50):22681-22687
9.
In this paper generalized type-I, generalized quasi type-I, generalized pseudo type-I and other related functions over cones
are defined for a vector minimization problem. Sufficient optimality conditions are studied for this problem using Clarke’s
generalized gradients. A Mond-Weir type dual is formulated and weak and strong duality results are established. 相似文献
10.