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131.

The effect of irrigation intervals was studied on physiological, morphological, and antioxidant traits of two marigold (Calendula officinalis L.) cultivars in Karaj, Iran, in a split-plot experiment based on a randomized complete block design with three replications. The experimental treatments included irrigation at three levels of I1 (irrigation interval of 3 days), I2 (irrigation interval of 5 days), and I3 (irrigation interval of 7 days) as the main plot and cultivar at two levels of V1 (cv. ‘sparse petal’) and V2 (cv. ‘compact petal’) as the sub-plot. The results based on the comparison of the means showed that the increase in irrigation interval from 3 to 7 days decreased the leaf area index, crop growth rate, relative growth rate, and net assimilation rate by 73.53, 85.76, 93.47, and 94.81%, respectively. It also decreased the flower yield, plant height, flower number, and leaf number by 71.92, 41.84, 99.31, and 58.67%, respectively. The interaction between irrigation and cultivar revealed that I3V1 had the highest total phenol content (3013.59 g gallic acid 100 g?1 tissue) and antioxidant capacity (60.8%). It can be inferred that the treatment of I1 and cv. ‘compact petal’ give the best results for flower yield and physiological and morphological traits, and the treatment of I3 and both cultivars provide the best results for antioxidant traits in the climatic conditions of the Karaj region.

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132.
Sodium-dependent, high-affinity glutamate transport is generally assumed to limit the toxicity of glutamate in vivo and in vitro, but there is very little direct evidence to support this hypothesis. In the present study, the effects of the specific uptake inhibitor l -trans-pyrrolidine-2,4-dicarboxylate on the toxicity and clearance of glutamate were examined in hippocampal neuronal cultures. At a concentration that was not toxic by itself, l -trans-pyrrolidine-2,4-dicarboxylate increased the toxicity of glutamate approximately fivefold and slowed the clearance of glutamate from the extracellular space. This toxicity was almost completely blocked by the N-methyl-d -aspartate receptor antagonist, d -2-amino-5-phosphonopentanoate. These studies provide direct evidence that sodium-dependent, high-affinity glutamate transport limits glutamate toxicity in vitro.  相似文献   
133.
The behavior of the acetamido (and benzamido) ambident, nucleophilic group under methylation with methyl iodide and silver oxide has been studied for several 2-acetamido-2-deoxy-D-glucose derivatives. When silver perchlorate was added, alkylation occurred at the oxygen atom, giving methyl imidates that were labile in acidic medium. Benzyl 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranoside was converted into N-(benzyl 3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranoside-2-yl) methyl acetimidate (83%), which was subsequently hydrolyzed quantitatively in acidic medium into the corresponding amine salt. Similar results were obtained with benzyl 3,4,6-tri-O-acetyl-2-benzamido-2-deoxy-β-d-glucopyranoside, methyl 2-acetamido-2-deoxy-3,4,6-tri-O-methyl-β-D-glucopyranoside, and benzyl 2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranoside. Under Kuhn's methylation conditions (methyl iodide-silver oxide-N,N-dimethylformamide), alkylation of the just mentioned derivatives occurred at both oxygen and nitrogen atoms.  相似文献   
134.
135.
The structure and conformation of the synthetic pentasaccharide Gal(beta 1-4){Fuc(alpha 1-3)}GlcNAc(beta 1-3)Gal(beta 1-4)Glc-beta OMe of the Lewis(X) family has been determined by NMR spectroscopy in dimethyl sulfoxide and methanol. In these solvents, the binding constants with calcium have been evaluated as 9.5 and 29.6 M-1, respectively. Study of the interaction sites has been achieved through the use of paramagnetic divalent cations and distance triangulation methods. Two regions have been found, the first one in the vicinity of the fucose unit, the second one closer to the lactose part.  相似文献   
136.
Exaggerated secondary sexual characteristics are apparently costly and seem to defy natural selection. This conundrum promoted the theory of sexual selection. Accordingly, exaggerated secondary sexual characteristics might be ornaments on which female choice is based and/or armaments used during male–male competition. Males of many cichlid fish species, including the adaptive radiation of Nicaraguan Midas cichlids, develop a highly exaggerated nuchal hump, which is thought to be a sexually selected trait. To test this hypothesis, we conducted a series of behavioral assays in F2 hybrids obtained from crossing a species with a relatively small hump and one with an exaggerated hump. Mate‐choice experiments showed a clear female preference for males with large humps. In an open‐choice experiment with limited territories, couples including large humped males were more successful in acquiring these territories. Therefore, nuchal humps appear to serve dual functions as an ornament for attracting mates and as an armament for direct contest with rivals. Although being beneficial in terms of sexual selection, this trait also imposes fitness costs on males possessing disproportionally large nuchal humps since they exhibit decreased endurance and increased energetic costs when swimming. We conclude that these costs illustrate trade‐offs associated with large hump size between sexual and natural selection, which causes the latter to limit further exaggeration of this spectacular male trait.  相似文献   
137.
Background:Decitabine is a potent anticancer hypomethylating agent and changes the gene expression through the gene''s promoter demethylation and also independently from DNA demethylation. So, the present study was designed to distinguish whether Decitabine, in addition to inhibitory effects on DNA methyltransferase, can change HDAC3 and HDAC7 mRNA expression in NALM-6 and HL-60 cancer cell lines.Methods:HL-60, NALM-6, and normal cells were cultured, and the Decitabine treatment dose was obtained (1 µM) through the MTT assay. Finally, HDAC3 and HDAC7 mRNA expression were measured by Real-Time PCR in HL-60 and NALM-6 cancerous cells before and after treatment. Furthermore, HDAC3 and HDAC7 mRNA expression in untreated HL-60 and NALM-6 cancerous cells were compared to normal cells.Results:Our results revealed that the expression of HDAC3 and HDAC7 in HL-60 and NALM-6 cells increases as compared to normal cells. After treatment of HL-60 and NALM-6 cells with Decitabine, HDAC3, and HDAC7 mRNA expression were decreased significantly.Conclusion:Our data confirmed that the effects of Decitabine are not limited to direct hypomethylation of DNMTs, but it can indirectly affect other epigenetic factors, such as HDACs activity, through converging pathways.Key Words: Decitabine, HDAC3, HDAC7, HL-60, NALM-6  相似文献   
138.
139.
Rhinoviruses are the most common infectious agents of humans. They are the principal etiologic agents of afebrile viral upper-respiratory-tract infections (the common cold). Human rhinoviruses (HRVs) comprise a genus within the family Picornaviridae. There are >100 serotypically distinct members of this genus. In order to better understand their phylogenetic relationship, the nucleotide sequence for the major surface protein of the virus capsid, VP1, was determined for all known HRV serotypes and one untyped isolate (HRV-Hanks). Phylogenetic analysis of deduced amino acid sequence data support previous studies subdividing the genus into two species containing all but one HRV serotype (HRV-87). Seventy-five HRV serotypes and HRV-Hanks belong to species HRV-A, and twenty-five HRV serotypes belong to species HRV-B. Located within VP1 is a hydrophobic pocket into which small-molecule antiviral compounds such as pleconaril bind and inhibit functions associated with the virus capsid. Analyses of the amino acids that constitute this pocket indicate that the sequence correlates strongly with virus susceptibility to pleconaril inhibition. Further, amino acid changes observed in reduced susceptibility variant viruses recovered from patients enrolled in clinical trials with pleconaril were distinct from those that confer natural phenotypic resistance to the drug. These observations suggest that it is possible to differentiate rhinoviruses naturally resistant to capsid function inhibitors from those that emerge from susceptible virus populations as a result of antiviral drug selection pressure based on sequence analysis of the drug-binding pocket.  相似文献   
140.
This paper describes an efficient synthesis of the beta-2-trimethylsilylethyl glycoside of lacto-N-fucoheptaose based on a highly stereo- and regioselective glycosylation between a Lewis(x) trisaccharidic donor and a tetraol tetrasaccharidic acceptor. The title compound was characterized by high-resolution NMR spectroscopy.  相似文献   
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