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991.
Craig A. Grapperhaus Majda Kreso Gretchen A. Burkhardt Julianna V.F. Roddy Mark S. Mashuta 《Inorganica chimica acta》2005,358(1):123-130
Alkylation of bis(2-aminoethanethiolato)nickel(II) (1) with alkylating agents containing pendant donor groups has been investigated. Reaction with 2-bromoethylamine is strictly sulfur-centered yielding (2-[(2-aminoethyl)thio]ethaneamine)nickel(II)bromide, [(DAES)2Ni]Br2 (2), which was isolated as a lilac solid. Addition of chloroacetamide yields the sulfur- and nitrogen-alkylated product (2-[(2-aminoethyl)thio]acetamide)nickel(II)chloride, (AETA)NiCl2 (3a), as a green solid. Recrystallization from water/acetone yields 3a as single crystals along with single crystals of [(AETA)NiCl(OH2)]Cl (3b). The strictly S-alkylated product (2-[(2-amino-2-oxoethyl)thio]acetamide)nickel(II)iodide, [(AOTA)2Ni]I2 (4), is obtained upon reaction of 1 with iodoacetamide. A pathway is proposed consistent with the observed leaving group effect on the site of alkylation. The X-ray structures of 3a, 3b, and 4 are reported and the hydrogen-bonding network is described. 相似文献
992.
993.
The preparation and characterization of organolithium O,C,O-pincer compound [2,6-(tBuOCH2)2C6H3]-Li (1) is described. The X-ray diffraction techniques revealed the dimeric structure of 1 consisting of two lithium atoms Li(1) and Li(2) and two monoanionic chelating aryl ligands in the solid state, where each lithium atom is coordinated by two oxygen atoms of two different ligands. The NMR spectroscopy and cryoscopy measurements established monomer-dimer equilibrium of 1 in concentrated solutions of non-coordinated solvents, while the diluted solutions of 1 consist of monomer only. 相似文献
994.
Steffen Pospiech 《Inorganica chimica acta》2011,374(1):566-571
The ditopic tris(2-mercaptoimidazol-1-yl)borate ligand K2[(mtEt)3B-B(mtEt)3] cannot be prepared from B2(NMe2)4/4 HmtEt/2 KmtEt, because the stable intramolecular diadduct (mtEt)B(μ-mtEt)2B(mtEt) is generated instead (HmtEt = 2-mercapto-1-ethylimidazole). Introduction of a meta- or para-phenylene spacer between the two boron atoms precludes the 2-mercaptoimidazol-1-yl groups from adopting a bridging position so that the potassium salts K2[(mtEt)3B-(m-C6H4)-B(mtEt)3] and K2[(mtEt)3B-(p-C6H4)-B(mtEt)3] become readily accessible. These ligands react with [(p-cym)RuCl2]2 to give the dinuclear RuII complexes [(p-cym)Ru(mtEt)3B-(m-C6H4)-B(mtEt)3Ru(p-cym)]Cl2 and [(p-cym)Ru(mtEt)3B-(p-C6H4)-B(mtEt)3Ru(p-cym)]Cl2 (p-cym = p-cymene). After the exchange of the Cl− counterions for [PF6]−, both complexes have been crystallized and structurally characterized by X-ray diffraction. 相似文献
995.
Synthesis and Characterization of the Hemi‐Salen Ligands and Their Triboron Complexes: Spectroscopy and Examination of Anticancer Properties 下载免费PDF全文
《化学与生物多样性》2018,15(1)
The synthesis, spectroscopic properties, and in vitro cytotoxicity activity of a series of various salen‐based triboron complexes have been designed and prepared from hemi‐salen ( L 1 H 3 – L 4 H 3 ) ligands and BF3·Et2O or BPh3 under simple reaction conditions. The hemi‐salen ( L 1 H 3 – L 4 H 3 ) ligands and their BF2 or BPh2 chelating triboron complexes were characterized by means of NMR (1H, 13C, 19F, and 11B) spectra, FT‐IR spectra, UV/VIS spectra, fluorescence spectra, mass spectra, melting point, as well as elemental analysis. The triboron [L (1 – 4) (BF 2 ) 3 ] and [L (1 – 4) (BPh 2 ) 3 ] complexes were investigated for their absorption and emission properties, and these complexes are also good chelates towards boron(III) fragments such as BF2 or BPh2 quantum yield in solution reaching up to 38%. The hemi‐salen ( L 1 H 3 – L 4 H 3 ) ligands and their BF2 or BPh2 chelating triboron complexes were tested for the in vitro anticancer activity against various cancer and normal cells (HeLa, DLD‐1, ECC‐1, PC‐3, PNT‐1A, and CRL‐4010), and it was found that the cell viability of cancer cells was decreased while most of the healthy cells could still be viable. Also, the cytotoxicity studies showed that anticancer activity of hemi‐salen ( L 1 H 3 – L 4 H 3 ) ligands is higher than that of triboron [L (1 – 4) (BF 2 ) 3 ] and [L (1 – 4) ( BP h 2 ) 3 ] complexes. The hemi‐salen ( L 1 H 3 – L 4 H 3 ) ligands showing the strongest cytotoxic effect in PC ‐3 cells were found to exhibit anticancer activity with apoptosis by increasing the level of ROS in the PC ‐3 cells. 相似文献
996.
INTroDUCTIONP-, E- and L-selectin are C-type lectins in-volved in the binding of circulating leukocytes tovarious target cellsll, 2]. The interaction(s) be-tween the selectins and the target cells is mediatedby oligosaccharide structures conjugated to specificligand molecules expressed on the taxget cell sur-faces. These ligand molecules may be recognized byone, two or all three of the selectins[1-31. AlthoughaVailable data suggest that the interaction(s) be-tween the selectins and their… 相似文献
997.
The DNA-binding protein from stationary phase (Dps) protein family plays an important role in protecting microorganisms from oxidative and nutritional stresses. In silico analysis of the promoter region of alr3808, a dpsA homologue from the cyanobacterium Nostoc sp. PCC7120 shows putative iron-boxes with high homology with those recognized by FurA (ferric uptake regulator). Evidence for the modulation of dpsA by FurA was obtained using in vitro and in vivo approaches. SELEX linked to PCR was used to identify PdpsA as a FurA target. Concurrently, EMSA assays showed high affinity of FurA for the dpsA promoter region. DpsA expression analysis in an insertional mutant of the alr1690-αfurA message (that exhibited an increased expression of FurA) showed a reduced synthesis of DpsA. These studies suggest that FurA plays a significant role in the regulation of the DpsA. 相似文献
998.
The structural chemistry of dihalogenopalladium(II) and platinum(II) complexes of 2-organochalcogenomethylpyridine ligands is described. Complexes with a methyl group in the 6-position of the pyridyl ring, 6-MepyCH2ER, form dimeric complexes [trans-PdX2(μ-6-MepyCH2SePh-N,Se)]2 (X = Br (1), I (2)) or mononuclear complexes trans-PdI2(6-MepyCH2SR-N)2 (R = Me (5), Ph (6)). Absence of a 6-methyl substituent results in the bidentate configuration observed for PdI2(pyCH2SePh-N,Se) (3) and PdI2(4-MepyCH2SMe-N,S) (4). Related platinum(II) complexes are mononuclear including PtCl2(6-MepyCH2SPh-N,S) (8) as an analogue of trimeric [trans-PdCl2(μ-6-MepyCH2SPh-N,S)]3. Differences between palladium and platinum appear to result from a combination of steric and electronic factors. 相似文献
999.
Jaykant Vora Shivani Patel Sonam Sinha Sonal Sharma Anshu Srivastava Mahesh Chhabria 《Journal of biomolecular structure & dynamics》2019,37(12):3150-3161
The transmission of mosquito-borne Chikungunya virus (CHIKV) has large epidemics worldwide. Till date, there are neither anti-viral drugs nor vaccines available for the treatment of Chikungunya. Accumulated evidences suggest that some natural compounds i.e., Epigallocatechin gallate, Harringtonine, Apigenin, Chrysin, Silybin, etc. have the capability to inhibit CHIKV replication in vitro. Natural compounds are known to possess less or no side effects. Therefore, natural compound in its purified or crude extracts form could be the preeminent and safe mode of therapies for Chikungunya. Wet lab screening and identification of natural compounds against Chikungunya targets is a time consuming and expensive exercise. In the present study, we used in silico techniques like receptor-ligand docking, Molecular dynamic (MD), Three Dimensional Quantitative Structure Activity Relation (3D-QSAR) and ADME properties to screen out potential compounds. Aim of the study is to identify potential lead/s from natural sources using in silico techniques that can be developed as a drug like molecule against Chikungunya infection and replication. Three softwares were used for molecular docking studies. Potential ligands selected by docking studies were subsequently subjected 3D-QSAR studies to predict biological activity. Based on docking scores and pIC50 value, potential anti-Chikungunya compounds were identified. Best docked receptor-ligands were also subjected to MD for more accurate estimation. Lipinski’s rule and ADME studies of the identified compounds were also studied to assess their drug likeness properties. Results of in silico findings, led to identification of few best fit compounds of natural origin against targets of Chikungunya virus which may lead to discovery of new drugs for Chikungunya.
Communicated by Ramaswamy H. Sarma 相似文献
1000.
目的:探讨甲氨蝶呤治疗急性淋巴细胞白血病的疗效及对患者B淋巴细胞刺激因子(BAFF)、增殖诱导配体(APRIL)的影响。方法:选择2016年8月至2018年9月我院收治的急性淋巴细胞白血病患者50例进行研究,以随机数表法分为观察组(n=26)和对照组(n=24)。对照组给予化疗治疗,观察组采用甲氨蝶呤治疗。比较两组患者的临床疗效、BAFF、APRIL、CD4~+、CD8~+、CD4~+/CD8~+水平变化情况及不良反应发生情况。结果:治疗后,观察组总有效率84.62%显著高于对照58.33%,差异显著(P0.05);治疗前,两组BAFF、APRIL水平无显著差异(P0.05);治疗后,两组BAFF、APRIL水平均显著下降,且观察组低于对照组(P0.05);治疗前,两组T淋巴细胞亚群水平无显著差异(P0.05);治疗后,两组T淋巴细胞亚群水平均显著改善,且观察组CD4~+、CD4~+/CD8~+高于对照组,CD8~+低于对照组(P0.05);两组患者不良反应发生情况均无统计学意义(P0.05)。结论:在急性淋巴细胞白血病患者中应用甲氨蝶呤效果显著,可有效改善患者BAFF、APRIL水平。 相似文献