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排序方式: 共有126条查询结果,搜索用时 46 毫秒
41.
Ziad Omran 《Molecules (Basel, Switzerland)》2021,26(11)
Monoacylglycerol lipase (MAGL) is a key enzyme in the human endocannabinoid system. It is also the main enzyme responsible for the conversion of 2-arachidonoyl glycerol (2-AG) to arachidonic acid (AA), a precursor of prostaglandin synthesis. The inhibition of MAGL activity would be beneficial for the treatment of a wide range of diseases, such as inflammation, neurodegeneration, metabolic disorders and cancer. Here, the author reports the pharmacological evaluation of new disulfiram derivatives as potent inhibitors of MAGL. These analogues displayed high inhibition selectivity over fatty acid amide hydrolase (FAAH), another endocannabinoid-hydrolyzing enzyme. In particular, compound 2i inhibited MAGL in the low micromolar range. However, it did not show any inhibitory activity against FAAH. 相似文献
42.
Manoj Kumar Yadav Akhilendra Kumar Maurya Gunjan Rajput Krishna Kumar Manar Manjula Vinayak Michael G. B. Drew 《Journal of Coordination Chemistry》2017,70(4):565-583
New planar trans-copper(II) β-dithioester complexes, [Cu(L)2] (L = methyl-3-hydroxy-(3-pyridyl)-2-propenedithioate (L1 in 1), methyl-3-hydroxy-(2-naphthyl)-2-propenedithioate (L2 in 2), methyl-3-hydroxy-3-(p-methoxyphenyl)-2-propenedithioate (L3 in 3), methyl-3-hydroxy-3-(p-fluorophenyl)-2-propenedithioate (L4 in 4), and methyl-3-hydroxy-3-(p-bromophenyl)-2-propenedithioate (L5 in 5)), have been synthesized and characterized by elemental (C, H, N and S) analysis, ESI-MS, IR, and UV-vis spectra. The structures of HL3 and its corresponding complex 3 have been determined by X-ray crystallography. Electrochemical behavior of all complexes has been studied by cyclic voltammetry. All five planar complexes show efficient DNA-binding and DNA (PBR322)-cleavage in a concentration-dependent manner (1 > 3 > 5 > 2 > 4). Cleavage efficiency is enhanced in the presence of H2O2 as well as ascorbic acid. However, the order of increased efficiency of Cu(II) chelates differs in the presence of H2O2 as 4 > 1 > 2 > 3 > 5. Among these complexes, the pyridyl- and methoxy-functionalized 1 and 3 have shown higher self-activating capability in DNA-cleavage. All complexes show significant variation in IC50 on MCF-7 cell line. Additionally, treatment with the complexes gradually increases apoptotic cell death in dose-dependent manner in RAW 264.7 cell line. These findings highlight potential cancer protective nature of these complexes. 相似文献
43.
For a prime p, we consider some natural classes of matrices over a finite field Fp of p elements, such as matrices of given rank or with characteristic polynomial having irreducible divisors of prescribed degrees. We demonstrate two different techniques which allow us to show that the number of such matrices in each of these classes and also with components in a given subinterval [-H, H] [-(p - 1)/2, (p - 1)/2] is asymptotically close to the expected value. 相似文献
44.
M. MerabetD. Rached R. Khenata S. BenaliaB. Abidri N. BettaharS. Bin Omran 《Physica B: Condensed Matter》2011,406(17):3247-3255
An accurate ab initio full potential linear muffin-tin orbital method has been used to investigate the structural, electronic and optical properties of BP, BAs and their (BP)n/(BAs)n superlattices (SLs). The exchange-correlation potential is treated with the local density approximation of Perdew and Wang (LDA-PW). The calculated structural properties of BP and BAs compounds are in good agreement with available experimental and theoretical data. It is found that BP, BAs and their alloys exhibit an indirect fundamental band gap. The fundamental band gap decreases with increasing the number of monolayer n. The optical properties show that the static dielectric constant significantly decreases in superlattices compared to their binary compounds. 相似文献
45.
Second derivative spectrophotometry was applied to determine the binding constant (K) between codeine phosphate (COD) and bovine serum albumin (BSA) at simulated physiological conditions (37.00?°C and pH = 7.4). The second derivative spectra of COD in buffer solutions containing various amounts of BSA showed derivative isosbestic points. The residual background signals derived from incomplete suppression of BSA signals can be entirely eliminated in the second derivative spectra indicating that BSA has spectrophotometrically one kind of binding site for COD. The fractions of COD bound to BSA were calculated from the derivative intensity differences (??D values) of COD before and after the addition of BSA. Scatchard plot calculation suggested that the binding of COD to BSA can be explained by a partition-like non-specific binding model. The binding constant (K) was calculated from ??D values according to the non-specific binding model by a nonlinear least-squares method. K values were almost constant for all of the COD concentrations studied with good reproducibility. The fractions predicted by the K values were in good agreement with the observed values. The results indicate the usefulness of the derivative method in drug?Calbumin binding studies without the need for prior separation procedures which may disturb the equilibrium states of the samples solutions. 相似文献
46.
Manar M. Arafeh Ebrahim Saeedian Moghadam Sirin A. I. Adham Raphael Stoll Raid J. Abdel-Jalil 《Molecules (Basel, Switzerland)》2021,26(14)
A novel series of 2-(aryldiazenyl)-3-methyl-1H-benzo[g]indole derivatives (3a–f) were prepared through the cyclization of the corresponding arylamidrazones, employing polyphosphoric acid (PPA) as a cyclizing agent. All of the compounds (3a–f) were characterized using 1H NMR, 13C NMR, MS, elemental analysis, and melting point techniques. The synthesized compounds were evaluated for cytotoxic activity against diverse human cancer cell lines by the National Cancer Institute. While all of the screened compounds were found to be cytotoxic at a 10 µM concentration, two of them (2c) and (3c) were subjected to five dose screens and showed a significant cytotoxicity and selectivity. 相似文献
47.
48.
Omran AA 《Chemical & pharmaceutical bulletin》2005,53(11):1498-1501
A rapid, sensitive and selective spectrophotometric method has been developed for the quantitative determination of dapsone (DAP) and metoclopramide hydrochloride (MCP) in both pure and dosage forms. Individual and simultaneous methods are based on the diazo coupling reaction of these drugs with benzoylacetone (BAC) in alkaline medium. The resulting azo dyes exhibit maximum absorption at 437 and 411 nm with a molar absorptivity of 4.14x10(4) and 2.97x10(4) l mol-1 cm-1 for DAP and MCP, respectively. Simultaneous determination of DAP and MCP was developed utilizing first-order digital derivative spectrophotometry. All variables have been optimized. No interferences were observed from drug excipients and the validity of the methods was tested against reference methods. 相似文献
49.
Gamal M. S. El Shafei Christine A. Philip Zinab A. Omran 《Journal of Thermal Analysis and Calorimetry》1997,48(2):373-383
N2 adsorption at 77 K was used to follow the change in the pore structure of silica (mesoporous) produced on heating at 300 and 600?C in the presence of different contents of mechanically mixed ZnO (15–85 mol%). Heating of pure silica at 300?C caused pore narrowing. This proceeded differently in the presence of ZnO, the pore system being split into two ranges of limited sizes. The pore widening effect upon heating silica at 600?C was greatly reduced upon the addition of ZnO, to the extent of the evolution of some micropores at low levels of ZnO. At both heating temperatures, the composition 30% ZnO represented a transient state through the flux of pore system change. The IR spectra indicated that at this composition the silica particles are more oblate. The pore structure variations due to heating at the examined temperatures correlated with the solid-state reactions that take place at 1000?C, where the spinel Zn2SiO4 is detected. 相似文献
50.
Ivan I. StoikovOmran A. Omran Svetlana E. SolovievaShamil K. Latypov Konstantin M. EnikeevAidar T. Gubaidullin Igor S. Antipin Alexander I. Konovalov 《Tetrahedron》2003,59(9):1469-1476
The three conformations of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis[(benzoyl)methoxy]-2,8,14,20-tetrathiacalix[4]arene 1: cone, partial cone and 1,3-alternate, were prepared by the treatment of 5,11,17,23-tetra-tert-butyl-2,8,14,20-tetrathiacalix[4]arene-25,26,27,28-tetraol (TCA) with α-bromo acetophenone in the presence of appropriate alkali carbonate M2CO3 (M=Na, K, Cs) as base catalyst in acetonitrile. Structure of the conformers were established by 1H NMR, 1H-1H COSY, 1D NOE, 2D ROESY and X-ray experiments. The alkali cation binding selectivity of the obtained macrocycles was investigated by the ion-pair extraction method. 相似文献