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51.
Jun Ruan Wenbo Zhang Hang Zhang Yun Chen Fawad Ur Rehman Hui Jiang Steffen Strehle Alberto Pasquarelli Xuemei Wang 《中国化学快报》2018,29(6):919-921
The new boron-doped nanocrystalline diamond microelectrode arrays (BNCD-MEAs) with 16 channels were designed to detect biological signals from some activated cancer cells. Upon recordings of the released H2O2 from cancer cells stimulated by ascorbic acid (AA), it can readily detect the reactive oxygen species (ROS) released from target cells, which will be helpful for the cancer cell recognition and also beneficial for further studying the cause of relevant disease. 相似文献
52.
Boris Orel Robi Ješe Aljaž Vilčnik Urška LavrenčIč Štangar 《Journal of Sol-Gel Science and Technology》2005,34(3):251-265
The aim of this study was, at first, to re-consider the IR spectra of methyltriethoxysilane (MTEOS) catalysed with HCl (hydrolysis) and to compare them with IR spectra of MTEOS catalysed with trifluoroacetic acid (TFAcOH). TFAcOH as a strong carboxylic acid performs non-hydrolytic sol-gel process based on the condensation between the alkoxide and the acid function, liberating ester molecules (solvolysis). We assessed from the time-dependent IR attenuated reflection spectroscopic (IR ATR) measurements the solvolysis and hydrolysis reactions, formation of the oligomeric species and final condensation products. Additional evidence for the formation of these species was obtained from the spectra of films dip-coated from sols aged to different extent. The results of the IR spectral analysis showed that the structure of both xerogels consisted of irregular Tn (n = 8, 10, 12) cube-like species bridged via the ladder-like oligomers (in the case of MTEOS/TFAcOH) and open-chain trisiloxane species (for MTEOS/HCl). 29Si NMR spectra of MTEOS/TFAcOH showed only signals of T3 while MTEOS/HCl spectra showed beside T3 also T2 signals, in agreement with IR spectra results. From the XRD peaks at low Bragg angles (∼ 9–10°) we inferred that both xerogels consisted of nanocrystalline CH3-SiO3/2 species. In addition, the surface energy values of the films deposited from the corresponding sols were measured and the dispersive and polar portions correlated with the spectral features noted in the films. 相似文献
53.
N. A. Andriyanova L. A. Smirnova Yu. D. Semchikov K. V. Kir’yanov N. V. Zaborshchikova V. F. Ur’yash N. V. Vostokov 《Polymer Science Series A》2006,48(5):483-488
Cyanoethyl chitosan derivatives with various substitution degrees have been synthesized by the nucleophilic addition of acrylonitrile to the functional groups of chitosan. The process proceeds under homogeneous conditions without any catalyst at various pH values and reagent concentrations in the temperature range of 273–333 K. The formation of cyanoethyl chitosans is established by a gain in the weight of chitosan, a change in its content of nitrogen, and the appearance of an absorption band at 2250 cm?1 in the IR spectrum which corresponds to the stretching vibrations of a-C≡N group. It has been shown that the most efficient addition of acrylonitrile occurs at 273 K and pH 5.5. Cyanoethyl chitosan samples show better mechanical parameters and are characterized by a lower ordering than the parent chitosan. 相似文献
54.
Ur?ka L. ?tangar Boris Orel Neva Gro?elj Patrick Judeinstein Franco Decker Panagiotis Lianos 《Monatshefte für Chemie / Chemical Monthly》2001,18(10):103-112
A hybrid silicon precursor (ICS-PPG) obtained by reaction of 3-isocyanatopropyltriethoxy silane with poly-(propyleneglycol)-bis-(2-aminopropyl ether) was recognized as a potential host for various salts and molecular species. It has been used for electrochromic, gasochromic, photovoltaic, and fuel cell applications. This focuses on proton conducting gels (PWA/ICS-PPG, SiWA/ICS-PPG, and W-PTA/ICS-PPG) obtained after the incorporation of polyoxometalates in the ICS-PPG host. IR spectroscopic measurements are used to reveal the entrapment, the aggregation, and the interactions of W-PTA, PWA, or SiWA with the sol-gel derived network. The proton conductivity of the composites, measured using impedance spectroscopy, increases with increasing concentration of the polyoxometalates from 10−6 to 10−3 S/cm. 相似文献
55.
56.
Duan Ni Jiacheng Wei Xinheng He Ashfaq Ur Rehman Xinyi Li Yuran Qiu Jun Pu Shaoyong Lu Jian Zhang 《Chemical science》2021,12(1):464
Allostery, which is one of the most direct and efficient methods to fine-tune protein functions, has gained increasing recognition in drug discovery. However, there are several challenges associated with the identification of allosteric sites, which is the fundamental cornerstone of drug design. Previous studies on allosteric site predictions have focused on communication signals propagating from the allosteric sites to the orthosteric sites. However, recent biochemical studies have revealed that allosteric coupling is bidirectional and that orthosteric perturbations can modulate allosteric sites through reversed allosteric communication. Here, we proposed a new framework for the prediction of allosteric sites based on reversed allosteric communication using a combination of computational and experimental strategies (molecular dynamics simulations, Markov state models, and site-directed mutagenesis). The desirable performance of our approach was demonstrated by predicting the known allosteric site of the small molecule MDL-801 in nicotinamide dinucleotide (NAD+)-dependent protein lysine deacetylase sirtuin 6 (Sirt6). A potential novel cryptic allosteric site located around the L116, R119, and S120 residues within the dynamic ensemble of Sirt6 was identified. The allosteric effect of the predicted site was further quantified and validated using both computational and experimental approaches. This study proposed a state-of-the-art computational pipeline for detecting allosteric sites based on reversed allosteric communication. This method enabled the identification of a previously uncharacterized potential cryptic allosteric site on Sirt6, which provides a starting point for allosteric drug design that can aid the identification of candidate pockets in other therapeutic targets.Using reversed allosteric communication, we performed MD simulations, MSMs, and mutagenesis experiments, to discover allosteric sites. It reproduced the known allosteric site for MDL-801 on Sirt6 and uncovered a novel cryptic allosteric Pocket X. 相似文献
57.
Muhammad Abdul Hamid Ejaz Ur Rehman Muhammad Fuzail Riffat Naheed Amin-Uddin Ahmed 《Journal of Radioanalytical and Nuclear Chemistry》1995,190(1):37-50
The oxidation-reduction reaction between U(VI) and Ti(III) in HCl solution was studied spectrophotometrically. The reaction is second-order at all concentrations of reactants, HCl, ferrous chloride and mannitol used in this work. In 5M HCl the rate constantk increases with increasing Ti(III) concentration, whereas it decreases with increasing U(VI) concentration, with increasing HCl concentration from 1.00M to 7.17M and increases thereafter from 7.17M to 11.79M. The addition of mannitol causes a consistent decrease in the rate of reaction, whereas ferrous chloride has no effect. The activation energy for this oxidation-reduction reaction was 47.90±0.11 kJ·mol–1. The values of H
, G
and S
were 45.40±0.11 kJ·mol–1, 72.50±0.17 kJ·mol–1 and –91.10±0.22J·k–1·mol–1, respectively. The mode of reaction is discussed in the light of kinetic results. 相似文献
58.
V. Rizzi G. Viesti D. Bazzacco A. Algora-Pineda D. Appelbe G. de Angelis N. Belcari M. Cinausero M. De Poli T.E. Drake A. Gadea A. Galindo-Uribarri N. Gelli D. Fabris E. Farnea E. Fioretto W. Krolas T. Kroll F. Lucarelli S. Lunardi M. Lunardon T. Martinez R. Menegazzo B.K. Nayak G. Nebbia D.R. Napoli B. Nyakó C. Petrache Zs. Podolyák G. Prete C. Rossi Alvarez A. Samant P. Spolaore C. Ur K. Zuber 《The European Physical Journal A - Hadrons and Nuclei》2000,7(3):299-301
The ridge structure with ΔEγ=±30 keV, observed in the past in coincidence with protons emitted in the reaction 187 MeV 37Cl +120Sn and attributed to an hyperdeformed nuclear shape in 152Dy, has been studied in a new experiment performed with the EUROBALL III array. The ridge is now observed in coincidence with
transitions in the yrast superdeformed band of 152Dy but no discrete rotational bands have been identified.
Received: 7 February 2000 相似文献
59.
Zs. Podolyák P. G. Bizzeti A. M. Bizzeti-Sona S. Lunardi D. Bazzacco A. Dewald A. Algora G. de Angelis M. De Poli E. Farnea A. Gadea D. R. Kasemann T. Klug Th. Kröll S. Lenzi D. R. Napoli C. M. Petrache R. Peusquens C. Rossi Alvarez T. Martinez C. A. Ur 《The European Physical Journal A - Hadrons and Nuclei》2000,8(2):147-151
The lifetime and the -decay to the 0+ ground state of the lowest 3- state in 148Gd has been determined. The reduced strength B(E3, 3-
0+)=41 (6) W.u. agrees well with the theoretical value from empirical shell model calculations and can be directly compared
with the 12+
9- two-octupole-phonon one-octupole-phonon strength obtained in the same Recoil Distance Method lifetime measurement. The results of our search
for a three octupole-phonon state built on the state is also reported.
Received: 7 March 2000 / Accepted: 12 May 2000 相似文献
60.
Urška L. Štangar Boris Orel Neva Grošelj Patrick Judeinstein Franco Decker Panagiotis Lianos 《Monatshefte für Chemie / Chemical Monthly》2001,132(1):103-112
Summary. A hybrid silicon precursor (ICS-PPG) obtained by reaction of 3-isocyanatopropyltriethoxy silane with poly-(propyleneglycol)-bis-(2-aminopropyl ether) was recognized as a potential host for various salts and molecular species. It has been used for electrochromic,
gasochromic, photovoltaic, and fuel cell applications. This focuses on proton conducting gels (PWA/ICS-PPG, SiWA/ICS-PPG, and W-PTA/ICS-PPG) obtained after the incorporation of polyoxometalates in the ICS-PPG host. IR spectroscopic measurements are used to reveal the entrapment, the aggregation, and the interactions of W-PTA, PWA, or SiWA with the sol-gel derived network. The proton conductivity of the composites, measured using impedance spectroscopy, increases
with increasing concentration of the polyoxometalates from 10−6 to 10−3 S/cm.
Received June 23, 2000. Accepted (revised) September 18, 2000 相似文献