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141.
Christopher M. Harris Anna M. Ericsson Maria A. Argiriadi Claude Barberis David W. Borhani Andrew Burchat David J. Calderwood George A. Cunha Richard W. Dixon Kristine E. Frank Eric F. Johnson Joanne Kamens Silvia Kwak Biqin Li Kelly D. Mullen Denise C. Perron Lu Wang Neil Wishart Xiaoyun Wu Xiaolei Zhang Robert V. Talanian 《Bioorganic & medicinal chemistry letters》2010,20(1):334-337
We describe structure-based optimization of a series of novel 2,4-diaminopyrimidine MK2 inhibitors. Co-crystal structures (see accompanying Letter) demonstrated a unique inhibitor binding mode. Resulting inhibitors had IC50 values as low as 19 nM and moderate selectivity against a kinase panel. Compounds 15, 31a, and 31b inhibit TNFα production in peripheral human monocytes. 相似文献
142.
Ricardo Z. Lorenzon Carlos E.L. Cunha Marcelo F. Marcondes Maria A. Juliano Luiz R. Travassos Adriana K. Carmona 《Archives of biochemistry and biophysics》2010,500(2):131-136
Oligopeptidase A (OpdA) belongs to the M3A subfamily of bacterial peptidases with catalytic and structural properties similar to mammalian thimet-oligopeptidase (TOP) and neurolysin (NEL). The three enzymes have four conserved Tyr residues on a flexible loop in close proximity to the catalytic site. In OpdA, the flexible loop is formed by residues 600-614 (600SHIFAGGYAAGYYSY614). Modeling studies indicated that in OpdA the Tyr607 residue might be involved in the recognition of the substrate with a key role in catalysis. Two mutants were constructed replacing Tyr607 by Phe (Y607F) or Ala (Y607A) and the influence of the site-directed mutagenesis in the catalytic process was examined. The hydrolysis of Abz-GXSPFRQ-EDDnp derivatives (Abz = ortho-aminobenzoic acid; EDDnp N-[2,4-dinitrophenyl]-ethylenediamine; X = different amino acids) was studied to compare the activities of wild-type OpdA (OpdA WT) and those of Y607F and Y607A mutants The results indicated that OpdA WT cleaved all the peptides only on the X-S bond whereas the Y607F and Y607A mutants were able to hydrolyze both the X-S and the P-F bonds. The kinetic parameters showed the importance of Tyr607 in OpdA catalytic activity as its substitution promoted a decrease in the kcat/Km value of about 100-fold with Y607F mutant and 1000-fold with Y607A. Both mutations, however, did not affect protein folding as indicated by CD and intrinsic fluorescence analysis. Our results indicate that the OpdA Tyr607 residue plays an important role in the enzyme-substrate interaction and in the hydrolytic activity. 相似文献
143.
144.
Maciel-de-Freitas R Marques WA Peres RC Cunha SP de Oliveira RL 《Memórias do Instituto Oswaldo Cruz》2007,102(4):489-496
Seasonal variation in container productivity and infestation levels by Aedes aegypti were evaluated in two areas with distinct levels of urbanization degrees in Rio de Janeiro, a slum and a suburban neighborhood. The four most productive containers can generate up to 90% of total pupae. Large and open-mouthed containers, such as water tanks and metal drums, located outdoors were the most productive in both areas, with up to 47.49% of total Ae. aegypti pupae collected in the shaded sites in the suburban area. Water-tanks were identified as key containers in both areas during both the dry and rainy seasons. Container productivity varied according to seasons and urbanization degree. However, the mean number of pupae per house was higher in the suburban area, but not varied between seasons within each area (P > 0.05). High infestation indexes were observed for both localities, with a house index of 20.5-21.14 in the suburban and of 9.56-11.22 in the urban area. This report gives potential support to a more focused and cost-effective Ae. aegypti control in Rio de Janeiro. 相似文献
145.
Bacterial density and productivity were investigated along four salinity gradients within the estuary Ria de Aveiro. Bacterial
variables and environmental parameters were measured at three to four stations spanning the entire salinity gradient of the
four channels. The rather high variation in bacterial productivity (0.16–7.6 μg C L−1 h−1) along the profiles of salinity indicates that bacterial activity shows a reactive behavior to environmental changing. Bacterial
density (0.5–11.2 × 109 cells L−1) with a comparative smaller variation showed a more conservative behavior, mainly reflecting the phytoplankton distribution.
Contrary to expectation, minimal values of bacterial productivity were not observed in November–December but in June. In fact,
in November–December, the deep zone near the mouth showed the highest values of bacterial activity. At the upper stations,
the highest values were observed in October. The relatively high values of bacterial production during the cold rainy season
suggest that allochthonous substrates leached out from the surroundings by rain controlled the distribution of bacterial activity
in the estuarine system. The substantial decrease in salinity during the rainy season negatively affected bacterial productivity,
namely in the marine zone, where water column was highly stratified. Salinity seems to play an indirect role in the regulation
of estuarine bacteria because there are different bacterial communities adapted to a wide salinity range. 相似文献
146.
Gelfuso EA Cunha AO Mortari MR Liberato JL Paraventi KH Beleboni RO Coutinho-Netto J Lopes NP dos Santos WF 《Life sciences》2007,80(6):566-572
The aims of the present study were to investigate the anticonvulsant activity and behavioral toxicity of FrPbAII using freely moving Wistar rats. Moreover, the effectiveness of this compound against chemical convulsants was compared to that of the inhibitor of the GABAergic uptake, nipecotic acid. Our results show that FrPbAII was effective against seizures induced by the i.c.v. injection of pilocarpine (ED(50) = 0.05 microg/animal), picrotoxin (ED(50) = 0.02 microg/animal), kainic acid (ED(50) = 0.2 microg/animal) and the systemic administration of PTZ (ED(50) = 0.03 microg/animal). The anticonvulsant effect of FrPbAII differed from that of nipecotic acid in potency, as the doses needed to block the seizures were more than 10 folds lower. Toxicity assays revealed that in the rotarod, the toxic dose of the FrPbAII is 1.33 microg/animal, and the therapeutic indexes were calculated for each convulsant. Furthermore, the spontaneous locomotor activity of treated animals was not altered when compared to control animals but differed from the animals treated with nipecotic acid. Still, FrPbAII did not induce changes in any of the behavioral parameters analyzed. Finally, when tested for cognitive impairments in the Morris water maze, the i.c.v. injection of FrPbAII did not alter escape latencies of treated animals. These findings indicate that the novel GABA uptake inhibitor is a potent anticonvulsant with mild side-effects when administered to Wistar rats. 相似文献
147.
A novel method for regenerating biosensors has been developed in which the highly specific detection of nucleic acid sequences is carried out using molecular padlock probe (MPP) technology and surface-associated rolling circle amplification (RCA). This technique has a low occurrence of false positive results when compared to polymerase chain reaction, and is an isothermal reaction, which is advantageous in systems requiring low power consumption such as remote field sensing applications. Gold-sputtered 96-well polystyrene microplates and a fluorescent label were used to explore the detection limits of the surface-associated RCA technique, specificity for different MPP, conditions for regeneration of the biomolecular sensing surface, and reproducibility of measurements on regenerated surfaces. The technique was used to create highly selective biomolecular surfaces capable of discriminating between DNA oligonucleotides with sequences identical to RNA from infectious salmon anemia (ISA) and infectious hematopoietic necrosis (IHN) virus. As little as 0.6 fmol of circularized MPP was detectable with this fluorimetric assay. The sensing layers could be reused for at least four cycles of amplification using thermal denaturation, with less than 33% decrease in RCA response over time. Because the nucleic acid product of the test is attached to a surface during amplification, the technique is directly applicable to a variety of existing sensing platforms, including acoustic wave and optical devices. 相似文献
148.
Effectiveness of sulfur with Acidithiobacillus and gypsum in chemical attributes of a Brazilian sodic soil 总被引:1,自引:1,他引:0
N. P. Stamford M. R. Ribeiro K. P. V. Cunha A. D. S. Freitas C. E. R. S. Santos S. H. L. Dias 《World journal of microbiology & biotechnology》2007,23(10):1433-1439
Gypsum and sulfur have been used as amendments for application in sodic and saline sodic soils, although gypsum is not effective
in soil pH reduction. In this study the combined effects of elemental sulfur inoculated with Acidithiobacillus (S*) and gypsum (G) in chemical attributes of a Brazilian solodic soil was evaluated. The treatments consisted in addition
of S* and G in various levels (0, 0.8, 1.6, 2.4, and 3.2 t ha−1) and different mixing proportions (100:0, 75:25, 50:50, 25:75, and 100:0), acting during 15, 30, and 45 days. Sulfur inoculated
with Acidithiobacillus (S*) markedly reduced soil pH in the leaching solution, especially when applied in the highest levels. Gypsum or sulfur applied
individually was not satisfactory for soil reclamation. At 15 days of incubation Na+, Ca2+, and Mg2+ showed higher values in the leaching solution, and a marked decrease was observed in the leaching solution at 30 days. Reduction
in soil electrical conductivity and in exchangeable Na+, Ca2+, and Mg2+ was observed and in a general way best results were achieved with S* : G in the ratio 50:50, using 2.4 and 3.2 t ha−1. Sulfur with Acidithiobacillus was more effective than gypsum in decreasing soil pH, and sulfur applied with gypsum in the proportion 50:50 showed the best
results in relation to exchangeable sodium and electrical conductivity and showed values below those used for classification
as sodic soils. 相似文献
149.
Amarildo Emanuel Correia Jordão Bruno Cogliati Bernard Ernesto Jensch-Junior Leandro Nogueira Pressinotti Osório Miguel Parra Francisco Javier Hernandez-Blazquez José Roberto Machado Cunha da Silva 《Polar Biology》2007,30(3):387-390
The Notothenia coriiceps liver is commonly infected with parasites, reducing the hepatic mass and inducing the regeneration. In order to better understand
the effect of nutrient influx on hepatic regeneration at 0°C, a usual mammal hepatotrophic factor (HF) solution was injected
into ten fish (HF group), while ten fish were injected with saline solution (control), twice a day, for 15 days. The liver
and carcass weight were measured, and samples were obtained for histological studies. The HF group presented a higher liver/carcass
weight (62.5%) than control group. This increase in liver mass was due mainly to hepatocytes hypertrophy, including nuclear
size increase and cytoplasmic inclusions of glycogen. Hyperplasia is also observed, although to a lesser extent. The hepatic
reaction to HF in Antarctic fish was here demonstrated for the first time, helping to understand the liver response to seasonal
nutrient. 相似文献
150.
Scalon Cunha LC Andrade e Silva ML Cardoso Furtado NA Vinhólis AH Gomes Martins CH da Silva Filho AA Cunha WR 《Zeitschrift für Naturforschung. C, Journal of biosciences》2007,62(9-10):668-672
Triterpene acids (ursolic, oleanoic, gypsogenic, and sumaresinolic acids) isolated from Miconia species, along with a mixture of ursolic and oleanolic acids and a mixture of maslinic and 2-a-hydroxyursolic acids, as well as ursolic acid derivatives were evaluated against the following microorganisms: Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, Streptococcus salivarius, Streptococcus sobrinus, and Enterococcus faecalis, which are potentially responsible for the formation of dental caries in humans. The microdilution method was used for the determination of the minimum inhibitory concentration (MIC) during the evaluation of the antibacterial activity. All the isolated compounds, mixtures, and semi-synthetic derivatives displayed activity against all the tested bacteria, showing that they are promising antiplaque and anticaries agents. Ursolic and oleanolic acids displayed the most intense antibacterial effect, with MIC values ranging from 30 microg/mL to 80 microg/mL. The MIC values of ursolic acid derivatives, as well as those obtained for the mixture of ursolic and oleanolic acids showed that these compounds do not have higher antibacterial activity when compared with the activity observed with either ursolic acid or oleanolic acid alone. With regard to the structure-activity relationship of triterpene acids and derivatives, it is suggested that both hydroxy and carboxy groups present in the triterpenes are important for their antibacterial activity against oral pathogens. 相似文献