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51.
Kaushik Ghosh Nidhi Tyagi Pramod Kumar Udai P. Singh Nidhi Goel 《Journal of inorganic biochemistry》2010,104(1):9-18
A new family of tridentate ligands PhimpH (2-((2-phenyl-2-(pyridin-2-yl)hydazono)methyl)phenol), N-PhimpH (2-((2-phenyl-2-(pyridin-2-yl)hydrazono)methyl)napthalen-1-ol), Me-PhimpH (2-(1-(2-phenyl-2-(pyridine-2-yl)hydrazono)ethyl)phenol) have been synthesized and characterized. The ligands PhimpH and N-PhimpH after deprotonation react with manganese(II) and manganese(III) starting materials affording [Mn(Phimp)2] (1), [Mn(Phimp)2](ClO4) (2), [Mn(N-Phimp)2] (3), [Mn(N-Phimp)2](ClO4) (4). Complexes [Mn(Phimp)2] (1) and [Mn(N-Phimp)2] (3) convert to [Mn(Phimp)2]+ (cation of 2) and [Mn(N-Phimp)2]+ (cation of 4) respectively upon oxidation. Ligand Me-PhimpH stabilized only manganese(III) centre resulting [Mn(Me-Phimp)2](ClO4) (5). The molecular structures of [Mn(Phimp)2], 1 and [Mn(Phimp)2](ClO4), 2 were determined by single crystal X-ray diffraction. X-ray crystal structures of 1 and 2 have revealed the presence of distorted octahedral MnN4O2 coordination sphere having meridionally spanning ligands. Electrochemical studies for the complexes showed Mn(II)/Mn(III), (E1/2 = 0.14-0.40 V) and Mn(III)/Mn(IV), (E1/2 = 0.80-1.06 V) couples vs. Ag/AgCl. The redox properties were exploited to examine superoxide dismutase (SOD) activity using Mn(II)/Mn(III) couple. The complexes 1, 2, 4 and 5 have been revealed to catalyze effectively the dismutation of superoxide () in xanthine-xanthine oxidase-nitro blue tetrazolium assay and IC50 values were found to be 0.29, 0.39, 1.12 and 0.76 μM respectively. DNA interaction studies with complex 2 showed binding of DNA in a non-intercalative pathway. Complexes 1, 2 and 4 exhibited nuclease activity in presence of H2O2 and inhibition of activity was noted in presence of KI. 相似文献
52.
Jagmohan S. Negi Pramod Singh Geeta J. Nee Pant Mohan S. Maniyari Rawat H. K. Pandey 《Biological trace element research》2010,135(1-3):275-282
The present study was carried out to determine the accumulation and variation of trace elements in roots and leaves of Asparagus racemosus collected from four different altitudes in Uttarakhand, India, by atomic absorption spectroscopy. The metals investigated were Zn, Cu, Mn, Fe, Co, Na, K, Ca, and Li. The concentration level of Fe was found to be highest at an altitude of 2,250 m, whereas the level of Cu was lowest. The maximum concentrations of Zn, Cu, Mn, Fe, Co, Na, K, Ca, and Li were found to be 165.0?±?3.2, 34.0?±?0.5, 84.0?±?0.7, 2,040.0?±?0.3, 122.0?±?1.5, 745.0?±?0.3, 13,260.0?±?3.5, 6,153.0?±?1.6, and 58.0?±?3.8 mg/kg, respectively. 相似文献
53.
Jagmohan S. Negi Pramod Singh Geeta J. nee Pant Mohan S. Maniyari Rawat 《Biological trace element research》2010,138(1-3):300-306
Variations of micro- and macrominerals concentration in Swertia speciosa were determined by atomic absorption spectroscopy. The mineral elements showed significant changes in roots and leaves collected from different altitudes. Among all the elements, highest concentration (more than 2,000 mg/kg) of Ca and K were recorded in S. speciosa and the concentration of other elements analyzed in the study decreased in the order Fe>Na>Zn>Co>Li>Cu>Mn. 相似文献
54.
A synthetic progestin Nestorone® is being developed for female-contraception. This study was conducted to determine the distribution, metabolism, and excretion of tritium-labeled Nestorone (3H Nestorone) in adult female rats. Rats were injected subcutaneously (S.C.) with a single dose of 400 μCi 3H Nestorone/kg BW. Its distribution and concentrations in blood, plasma and other tissues were determined at defined times. The excreta were examined for elimination of 3H Nestorone. Radioactivity in all samples was analyzed by liquid scintillation counter. Metabolite profiling was performed by HPLC and LC/MS analysis of the plasma, urine, and feces samples. Following subcutaneous injection of 3H Nestorone, the mean peak concentrations of radioactivity (Cmax) in the blood and plasma were 58.1 and 95.5 ng equiv. 3H Nestorone/g, respectively, at 2-h postdose (Tmax). Thereafter, the concentration of drug steadily declined through 96-h postdose with a terminal elimination half-life (t1/2) of 15.6 h. 3H Nestorone-derived radioactivity was widely distributed in most tissues by 0.5 h and attained a mean maximal concentration by 2-h postdose. Approximately, 81.4% and 7.62% of the administered dose was excreted via feces and urine, respectively. In vivo metabolism of 3H Nestorone resulted into a total of 19 metabolites. Among them, two metabolites viz., 17α-deacetyl-Nestorone (M9) and 4,5-dihydro-17α-deacetyl-Nestorone (M19) were identified by HPLC and LC/MS analysis. Metabolite profiling of plasma samples showed that most of the circulating radioactivity was associated with unchanged parent drug, and M19. The M19 was a major metabolite in the profiled urine and feces samples. Presence of large proportion of drug/drug-related material in feces suggested that the biliary excretion is a main elimination route of 3H Nestorone. The distribution, metabolism, and excretion profiles of 3H Nestorone obtained in this study provide a fairly good insight about its fate in women. 相似文献
55.
Ashish V. Tendulkar Babatunde Ogunnaike Pramod P. Wangikar 《Journal of biosciences》2007,32(1):899-908
The classical approaches for protein structure prediction rely either on homology of the protein sequence with a template structure or on ab initio calculations for energy minimization. These methods suffer from disadvantages such as the lack of availability of homologous template structures or intractably large conformational search space, respectively. The recently proposed fragment library based approaches first predict the local structures, which can be used in conjunction with the classical approaches of protein structure prediction. The accuracy of the predictions is dependent on the quality of the fragment library. In this work, we have constructed a library of local conformation classes purely based on geometric similarity. The local conformations are represented using Geometric Invariants, properties that remain unchanged under transformations such as translation and rotation, followed by dimension reduction via principal component analysis. The local conformations are then modeled as a mixture of Gaussian probability distribution functions (PDF). Each one of the Gaussian PDF’s corresponds to a conformational class with the centroid representing the average structure of that class. We find 46 classes when we use an octapeptide as a unit of local conformation. The protein 3-D structure can now be described as a sequence of local conformational classes. Further, it was of interest to see whether the local conformations can be predicted from the amino acid sequences. To that end, we have analyzed the correlation between sequence features and the conformational classes. 相似文献
56.
Hydrogen-bonding interactions of steroid-based cyclic and acyclic receptors containing 2,6-bis(acylamino)pyridine with uracil derivatives were studied in CDCl(3). Acyclic receptors show better binding behaviour as compared to cholaphanes with uracil derivatives. 相似文献
57.
Gholap AR Toti KS Shirazi F Kumari R Bhat MK Deshpande MV Srinivasan KV 《Bioorganic & medicinal chemistry》2007,15(21):6705-6715
A series of 2-amino-5-oxo-4-phenyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile and various analogues have been synthesized in excellent isolated yields starting from various arylidenemalononitrile and 3-amino-2-cyclohexen-1-one in 1-propanol as solvent at reflux temperature in the absence of any added catalyst. All the synthesized compounds were evaluated for their antifungal activity. The relationship between functional group variation and biological activity of the evaluated compounds is discussed in the article. 相似文献
58.
Brassinin is a plant defense metabolite with antimicrobial activity produced de novo by a variety of Brassica species in response to stress, that is, a phytoalexin. The inhibition of brassinin oxidase (BO), a brassinin-detoxifying enzyme produced by the phytopathogenic fungus Leptosphaeria maculans, is a target in our continuing search for novel crop protection agents. To probe the substrate specificity of BO, in particular the mechanism of the detoxification step, several analogues of brassinin, including functional group isosteres ((mono/dithio)carbamate, urea, and thiourea) and homologue methyl tryptaminedithiocarbamate, were investigated using fungal cultures and purified BO. It was concluded that the essential structural features of substrates of BO were: (i) an -NH at the (mono/dithio)carbamate, urea or thiourea group; (ii) a methylene bridge between indole and the functional group; (iii) a methyl or ethyl group attached to the thiol moiety of the (mono/di)thiocarbamate group. A general stepwise pathway for the oxidation of brassinin was proposed that accounts for the structural requirements of detoxification of brassinin analogues in L. maculans. All compounds that were BO substrates appeared to be oxidized in mycelial cultures to aldehydes, except for the two most polar compounds N'-(3-indolylmethyl)-N'-methylurea and methyl N'-(3-indolylmethyl)carbamate. The substrate specificity of BO suggests that selective inhibitors can be designed for the potential control of L. maculans. 相似文献
59.
Muhammad Yasir Asghar Melissa Magnusson Kati Kemppainen Pramod Sukumaran Christoffer L?f Ilari Pulli Veronica Kalhori Kid T?rnquist 《The Journal of biological chemistry》2015,290(26):16116-16131
The identity of calcium channels in the thyroid is unclear. In human follicular thyroid ML-1 cancer cells, sphingolipid sphingosine 1-phosphate (S1P), through S1P receptors 1 and 3 (S1P1/S1P3), and VEGF receptor 2 (VEGFR2) stimulates migration. We show that human thyroid cells express several forms of transient receptor potential canonical (TRPC) channels, including TRPC1. In TRPC1 knockdown (TRPC1-KD) ML-1 cells, the basal and S1P-evoked invasion and migration was attenuated. Furthermore, the expression of S1P3 and VEGFR2 was significantly down-regulated. Transfecting wild-type ML-1 cells with a nonconducting TRPC1 mutant decreased S1P3 and VEGFR2 expression. In TRPC1-KD cells, receptor-operated calcium entry was decreased. To investigate whether the decreased receptor expression was due to attenuated calcium entry, cells were incubated with the calcium chelator BAPTA-AM (1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid). In these cells, and in cells where calmodulin and calmodulin-dependent kinase were blocked pharmacologically, S1P3 and VEGFR2 expression was decreased. In TRPC1-KD cells, both hypoxia-inducible factor 1α expression and the secretion and activity of MMP2 and MMP9 were attenuated, and proliferation was decreased in TRPC1-KD cells. This was due to a prolonged G1 phase of the cell cycle, a significant increase in the expression of the cyclin-dependent kinase inhibitors p21 and p27, and a decrease in the expression of cyclin D2, cyclin D3, and CDK6. Transfecting TRPC1 to TRPC1-KD cells rescued receptor expression, migration, and proliferation. Thus, the expression of S1P3 and VEGFR2 is mediated by a calcium-dependent mechanism. TRPC1 has a crucial role in this process. This regulation is important for the invasion, migration, and proliferation of thyroid cancer cells. 相似文献
60.
Mukund A. Prabhu Narayanan Namboodiri Srinivas Prasad BV S.P. Abhilash Anees Thajudeen Kumar V.K. Ajith 《Indian pacing and electrophysiology journal》2015,15(6):286-290