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281.
Casey Schlenker Smita Menon C. Martin Lawrence Valérie Copié 《Biomolecular NMR assignments》2009,3(2):219-222
Crenarchaeal viruses are commonly found in hyperthermal acidic environments such as those of Yellowstone National Park. These
remarkable viruses not only exhibit unusual morphologies, but also display extreme genetic diversity. However, little is known
about crenarchaeal viral life cycles, virus–host interactions, and their adaptation to hyperthermophilic environments. In
an effort to better understand the functions of crenarchaeal viruses and the proteins encoded by their genomes, we have undertaken
detailed structural and functional studies of gene products encoded in the open reading frames of Sulfolobus spindle-shaped virus ragged hills. Herein, we report (15N, 13C, 1H) resonance assignments of backbone and side chain atoms of a 19.1 kDa homodimeric E73 protein of SSVRH. 相似文献
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Replication has become the gold standard for assessing statistical results from genome-wide association studies. Unfortunately this replication requirement may cause real genetic effects to be missed. A real result can fail to replicate for numerous reasons including inadequate sample size or variability in phenotype definitions across independent samples. In genome-wide association studies the allele frequencies of polymorphisms may differ due to sampling error or population differences. We hypothesize that some statistically significant independent genetic effects may fail to replicate in an independent dataset when allele frequencies differ and the functional polymorphism interacts with one or more other functional polymorphisms. To test this hypothesis, we designed a simulation study in which case-control status was determined by two interacting polymorphisms with heritabilities ranging from 0.025 to 0.4 with replication sample sizes ranging from 400 to 1600 individuals. We show that the power to replicate the statistically significant independent main effect of one polymorphism can drop dramatically with a change of allele frequency of less than 0.1 at a second interacting polymorphism. We also show that differences in allele frequency can result in a reversal of allelic effects where a protective allele becomes a risk factor in replication studies. These results suggest that failure to replicate an independent genetic effect may provide important clues about the complexity of the underlying genetic architecture. We recommend that polymorphisms that fail to replicate be checked for interactions with other polymorphisms, particularly when samples are collected from groups with distinct ethnic backgrounds or different geographic regions. 相似文献
285.
Huiqing Zhan Jan M. Spitsbergen Wei Qing Yi Lian Wu Thomas A. Paul James W. Casey Guor Muor Her Zhiyuan Gong 《Marine biotechnology (New York, N.Y.)》2010,12(6):640-649
A retrovirus homologue gene of cellular cyclin D
1
, walleye dermal sarcoma virus rv-cyclin gene (orf A or rv-cyclin), was expressed in the livers of zebrafish under the control of liver fatty acid-binding protein (lfabp) promoter. To prevent possible fatality caused by overexpression of the oncogene, the GAL4/upstream activation sequence (GAL4/UAS)
system was used to maintain the transgenic lines. Thus, both GAL4-activator [Tg(lfabp:GAL4)] and UAS-effector [Tg(UAS:rvcyclin)] lines were generated, and the rv-cyclin gene was activated in the liver after crossing these two lines. Since no obvious neoplasia phenotypes were observed in the
double-transgenic line, cancer susceptibility of the transgenic fish expressing rv-cyclin was tested by carcinogen treatment. Unexpectedly, transgenic fish expressing rv-cyclin gene (rvcyclin+) were more resistant to the carcinogen than siblings not expressing this gene (rvcyclin–). Lower incidences
of multiple and malignant liver tumors were observed in rvcyclin+ than in rvcyclin– fish, and the liver tumors in the rvcyclin+
group appeared later and were less malignant. These results suggest that expression of rv-cyclin protects the fish liver from carcinogen damage and delays onset of malignancy. These findings indicate that transgenic fish
models are powerful systems for investigating mechanisms of inhibition and regression of liver tumors. 相似文献
286.
Background
The task of recognizing and identifying species names in biomedical literature has recently been regarded as critical for a number of applications in text and data mining, including gene name recognition, species-specific document retrieval, and semantic enrichment of biomedical articles. 相似文献287.
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Boardman JD Blalock CL Corley RP Stallings MC Domingue BW Mcqueen MB Crowley TJ Hewitt JK Lu Y Field SH 《Biodemography and social biology》2010,56(2):123-136
This article combines social and genetic epidemiology to examine the influence of self-reported ethnicity on body mass index (BMI) among a sample of adolescents and young adults. We use genetic information from more than 5,000 single nucleotide polymorphisms in combination with principal components analysis to characterize population ancestry of individuals in this study. We show that non-Hispanic white and Mexican-American respondents differ significantly with respect to BMI and differ on the first principal component from the genetic data. This first component is positively associated with BMI and accounts for roughly 3% of the genetic variance in our sample. However, after controlling for this genetic measure, the observed ethnic differences in BMI remain large and statistically significant. This study demonstrates a parsimonious method to adjust for genetic differences among individual respondents that may contribute to observed differences in outcomes. In this case, adjusting for genetic background has no bearing on the influence of self-identified ethnicity. 相似文献
290.
Talbot HK Rock MT Johnson C Tussey L Kavita U Shanker A Shaw AR Taylor DN 《PloS one》2010,5(12):e14442