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41.
42.
Shibaji Ghosh Nellore Bhanu Chandar Kalyanashis Jana Bishwajit Ganguly 《Journal of computer-aided molecular design》2017,31(8):729-742
Inhibition of acetylcholinesterase (AChE) with organophosphorus compounds has a detrimental effect on human life. Oxime K203 seems to be one of the promising reactivators for tabun-inhibited AChE than (K027, K127, and K628). These reactivators differ only in the linker units between the two pyridinium rings. The conformational analyses performed with quantum chemical RHF/6-31G* level for K027, K127, K203 and K628 showed that the minimum energy conformers have different orientations of the active and peripheral pyridinium rings for these reactivator molecules. K203 with (–CH2–CH=CH–CH2–) linker unit possesses more open conformation compared to the other reactivators. Such orientation of K203 experiences favorable interaction with the surrounding residues of catalytic anionic site (CAS) and peripheral anionic site (PAS) of tabun-inhibited AChE. From the steered molecular dynamics simulations, it has been observed that the oxygen atom of the oxime group of K203 reactivator approaches nearest to the P-atom of the SUN203 (3.75 Å) at lower time scales (less than ~1000 ps) as compared to the other reactivators. K203 experiences less number of hydrophobic interaction with the PAS residues which is suggested to be an important factor for the efficient reactivation process. In addition, K203 crates large number of H-bonding with CAS residues SUN203, Phe295, Tyr337, Phe338 and His447. K203 barely changes its conformation during the SMD simulation process and hence the energy penalty to adopt any other conformation is minimal in this case as compared to the other reactivators. The molecular mechanics and Poisson–Boltzmann surface area binding energies obtained for the interaction of K203 inside the gorge of tabun inhibited AChE is substantially higher (?290.2 kcal/mol) than the corresponding K628 reactivator (?260.4 kcal/mol), which also possess unsaturated aromatic linker unit. 相似文献
43.
S. Caleb Noble Chandar D. Sangeetha M. N. Arumugham 《Journal of solution chemistry》2011,40(4):608-620
Abstract The critical micelle concentrations (CMC) of three metallosurfactant Schiff base cobalt(III) complexes of the type
[Co(trien)(C19H30NO)]Cl2,[Co(trien) (C23H38NO)]Cl2 and [Co(trien)(C25H42NO)]Cl2, where trien = triethylenetetramine, have been studied in n-alcohol and in formamide at different temperatures by the electrical conductivity method. CMCs have also been measured as
a function of percentage concentration of alcohol in the mixed solvents with formamide. Specific conductivity data (at 303–323 K)
served for the evaluation of the temperature-dependent CMC and thermodynamic parameters such as the standard Gibbs energy
changes (DG°mic)\Delta G^{\circ}_{\mathrm{mic}}), enthalpy changes (DH°mic)\Delta H^{\circ}_{\mathrm{mic}}), and entropy changes (DS°mic)\Delta S^{\circ}_{\mathrm{mic}}) of micelle formation. It is suggested that addition of an alcohol leads to increased penetration of formamide into the micellar
interface, the extent depending on the alcohol’s chain length. The results have been discussed in terms of the solvophobic
interaction, dielectric constant of the medium, the chain length of the alcohol, and the surfactant in the solvent mixture. 相似文献
44.
N. H. Ahabchane E. M. Essassi J. Bellan L. Lopez L. Lamandé 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):175-192
Abstract De nouveaux macrocycles de structures variées, renfermant une ou deux unités pyrazolylbenzimidazoles au sein d'une cha[icaron]ne polyéthylèneglyco1 ont été préparés par condensation, en catalyse par transfert de phase solide-liquide, de la 1-[3(5)-phénylpyrazol-5(3)-yl] benzimidazole-2-thione 1 avec le dichlorotétraéthylèneglycol 4 d'une part, et du 1,8(1,11)bis-[1-[3(5)-phtnylpyrazol-5(3)-yl] benzimidazol-2-yl]mercapto tri (tétra) glycol 9(10) avec les dichloropolyéthylèneglycols 3 et 4, d'autre part. 相似文献
45.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Aguilo E Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Ancu LS Andeen T Anderson S Andrieu B Anzelc MS Arnoud Y Arov M Arthaud M Askew A Asman B Jesus AC Atramentov O Autermann C Avila C Ay C Badaud F Baden A Bagby L Baldin B Bandurin DV Banerjee P Banerjee S Barberis E Barfuss AF Bargassa P Baringer P Barreto J Bartlett JF Bassler U Bauer D Beale S Bean A Begalli M Begel M Belanger-Champagne C Bellantoni L 《Physical review letters》2007,99(13):131801
Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles' decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino (g), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410 pb(-1) of pp collisions at square root(s) = 1.96 TeV collected with the D0 detector during Run II of the Fermilab Tevatron collider are analyzed in search of such "stopped gluinos" decaying into a gluon and a neutralino (chi(1)(0)). Limits are placed on the (gluino cross section) x (probability to stop) x [BR(g --> g chi(1)(0))] as a function of the gluino and chi(1)(0) masses, for gluino lifetimes from 30 micros-100 h. 相似文献
46.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Aguilo E Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Ancu LS Andeen T Anderson S Andrieu B Anzelc MS Arnoud Y Arov M Arthaud M Askew A Asman B Assis Jesus AC Atramentov O Autermann C Avila C Ay C Badaud F Baden A Bagby L Baldin B Bandurin DV Banerjee S Banerjee P Barberis E Barfuss AF Bargassa P Baringer P Barreto J Bartlett JF Bassler U Bauer D Beale S Bean A Begalli M Begel M Belanger-Champagne C 《Physical review letters》2007,99(5):052001
We report the first direct observation of the strange b baryon Xi(b)- (Xi(b)+). We reconstruct the decay Xi(b)- -->J/psiXi-, with J/psi-->mu+mu-, and Xi--->Lambdapi--->ppi-pi- in pp collisions at square root of s =1.96 TeV. Using 1.3 fb(-1) of data collected by the D0 detector, we observe 15.2 +/- 4.4(stat)(-0.4)(+1.9)(syst) Xi(b)- candidates at a mass of 5.774 +/- 0.011(stat) +/- 0.015(syst) GeV. The significance of the observed signal is 5.5 sigma, equivalent to a probability of 3.3 x 10(-8) of it arising from a background fluctuation. Normalizing to the decay Lambda(b)-->J/psiLambda, we measure the relative rate sigma(Xi(b-) x B(Xi)b})- -->J/psiXi-)/sigma(Lambda(b)) x B(Lambda(b)-->J/psiLambda) = 0.28+/-0.09(stat)(-0.08)(+0.09)(syst). 相似文献
47.
S. V. Baryshnikova E. V. Bellan A. I. Poddel’skii I. V. Smolyaninov N. T. Berberova G. A. Abakumov 《Doklady Chemistry》2017,474(1):101-104
A new mixed-ligand tin(IV) complex 2 derived from 3,6-di-tert-butyl-o-benzoquinone and ferrocenylaldimine phenol 1 has been prepared and characterized by different physicochemical methods (IR, 1HNMR, and 119Sn NMR spectroscopies). Electrochemical transformations of complex 2 have been studied by cyclic voltammetry. Catecholate and ferrocenyl groups have been found to take part in the redox transformations. Chemical oxidation of complex 2 with silver triflate in a dichloromethane solution has been studied. Formation of monocationic complex 2 + has been detected by EPR spectroscopy. The catecholate ligand has been found to be the primary redox center subjected to oxidation. 相似文献
48.
BaTiO3 nanoparticles prepared by wet chemical method were thermally grown onto well cleaned glass substrates under the vacuum of 2 × 10−5 Torr, using 12A4 Hind Hivac coating unit. An Al–BaTiO3–Al sandwich structure has been used for electrical conduction properties in the temperature range 303–423 K. The composition of nanoparticles and thin films were identified by EDS spectrum. The structural studies have been performed by the X-ray diffraction (XRD) technique. The X-ray analysis showed that the nano particle has a tetragonal structure and deposited films at a lower thickness amorphous in nature, whereas the crystallinity increases with increase of thickness. In the DC conduction studies, the current–voltage characteristics of the films showed ohmic conduction in the low voltage region. In the higher voltage region, a space charge limited conduction (SCLC) takes place due to the presence of the trapping level. The activation energy was estimated and the values found to decrease with increasing applied voltage. The zero field value of the activation energy is found to be 0.31 eV. The free carrier mobility, carrier density and trap density values were calculated and reported in this paper. 相似文献
49.
50.
Bellan PM 《Physical review letters》1985,54(13):1381-1384