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排序方式: 共有693条查询结果,搜索用时 15 毫秒
81.
Islam MR Jimenez T Pelham C Rodova M Puri S Magenheimer BS Maser RL Widmann C Calvet JP 《The Journal of biological chemistry》2010,285(50):38818-38831
82.
We have previously shown that GAA trinucleotide repeats have undergone significant expansion in the human genome. Here we present the analysis of the length distribution of all 10 nonredundant trinucleotide repeat motifs in 20 complete eukaryotic genomes (6 mammalian, 2 nonmammalian vertebrates, 4 arthropods, 4 fungi, and 1 each of nematode, amoebozoa, alveolate, and plant), which showed that the abundance of large expansions of GAA trinucleotide repeats is specific to mammals. Analysis of human-chimpanzee-gorilla orthologs revealed that loci with large expansions are species-specific and have occurred after divergence from the common ancestor. PCR analysis of human controls revealed large expansions at multiple human (GAA)(30+) loci; nine loci showed expanded alleles containing >65 triplets, analogous to disease-causing expansions in Friedreich ataxia, including two that are in introns of genes of unknown function. The abundance of long GAA trinucleotide repeat tracts in mammalian genomes represents a significant mutation potential and source of interindividual variability. 相似文献
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Ali S Banerjee S Logna F Bao B Philip PA Korc M Sarkar FH 《Journal of cellular physiology》2012,227(10):3373-3380
Human pancreatic cancer (PC) is an aggressive disease, which has been recapitulated in transgenic animal model that provides unique opportunity for mechanistic understanding of disease progression and also for testing the efficacy of novel therapeutics. Emerging evidence suggests deregulated expression of microRNAs (miRNAs) in human PC, and thus we investigated the expression of miRNAs in pancreas tissues obtained from transgenic mouse models of K-Ras (K), Pdx1-Cre (C), K-Ras;Pdx1-Cre (KC), and K-Ras;Pdx1-Cre;INK4a/Arf (KCI), initially from pooled RNA samples using miRNA profiling, and further confirmed in individual specimens by quantitative RT-PCR. We found over-expression of miR-21, miR-221, miR-27a, miR-27b, and miR-155, and down-regulation of miR-216a, miR-216b, miR-217, and miR-146a expression in tumors derived from KC and KCI mouse model, which was consistent with data from KCI-derived RInk-1 cells. Mechanistic investigations revealed a significant induction of EGFR, K-Ras, and MT1-MMP protein expression in tissues from both KC and KCI mouse compared to tissues from K or C, and these results were consistent with similar findings in RInk-1 cells compared to human MIAPaCa-2 cells. Furthermore, miR-155 knock-down in RInk-1 cells resulted in the inhibition of cell growth and colony formation consistent with down-regulation of EGFR, MT1-MMP, and K-Ras expression. In addition, miR-216b which target Ras, and forced re-expression of miR-216b in RInk-1 cells showed inhibition of cell proliferation and colony formation, which was correlated with reduced expression of Ras, EGFR, and MT1-MMP. These findings suggest that these models would be useful for preclinical evaluation of novel miRNA-targeted agents for designing personalized therapy for PC. 相似文献
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Savita Rani Sanjeev Kumar Syed Mudassir Jeelani Raghbir Chand Gupta Santosh Kumari 《Plant Systematics and Evolution》2012,298(2):485-497
At present 14 species of Potentilla L. have been cytologically worked out from different geographical areas of Kashmir and Himachal Pradesh in the Western Himalayas.
New chromosome numbers in nine species—Potentilla argyrophylla (n = 14), P. atrosanguinea (n = 7, 14), P. desertorum (n = 7), P. gerardiana (n = 14), P. indica (n = 14), P. micropetala (n = 14), P. nepalensis (n = 14), P. sibbaldia (n = 14) and P. thomsonii (n = 7)—have been reported on a worldwide basis for the first time. Additional chromosomal races of polyploid cytotypes for
P. argyrophylla (n = 28) and P. desertorum (n = 14) along with a diploid cytotype for P. micropetala (n = 7) plus diploid cytotypes for the five species as P. fulgens (n = 7), P. gelida (n = 7), P. kleiniana (n = 7), P. sibbaldia (n = 7) and P. sundaica (n = 7) as well as a tetraploid cytotype for P. fruticosa (n = 14) all have been cytologically worked out from India for the first time. The course of meiosis varies from normal to abnormal
in different populations of the majority of the species, such as P. argyrophylla, P. atrosanguinea, P. desertorum, P. fruticosa, P. fulgens, P. gelida, P. indica, P. nepalensis, P. sibbaldia and P. sundaica, except for normal meiosis observed in P. gerardiana, P. kleiniana, P. micropetala and P. thomsonii. The anomalous taxa are marked with meiotic abnormalities in the form of cytomixis, chromosomal stickiness, unoriented bivalents,
formation of laggards and bridges resulting in abnormal microsporogenesis, and production of heterogenous-sized fertile pollen
grains along with reduced pollen fertility. All the taxa with normal meiotic courses show nearly one hundred percent pollen
fertility. 相似文献
89.
S Sahu K Ray MS Yogendra Kumar S Gupta H Kauser S Kumar K Mishra U Panjwani 《Phytomedicine》2012,19(10):924-929
The present study was performed to investigate the effects of Valeriana wallichi (VW) aqueous root extract on sleep-wake profile and level of brain monoamines on Sprague-Dawley rats. Electrodes and transmitters were implanted to record EEG and EMG in freely moving condition and the changes were recorded telemetrically after oral administration of VW in the doses of 100, 200 and 300 mg/kg body weight. Sleep latency was decreased and duration of non-rapid eye movement (NREM) sleep was increased in a dose dependent manner. A significant decrease of sleep latency and duration of wakefulness were observed with VW at doses of 200 and 300 mg/kg. Duration of NREM sleep as well as duration of total sleep was increased significantly after treatment with VW at the doses of 200 and 300 mg/kg. VW also increased EEG slow wave activity during NREM sleep at the doses of 200 and 300 mg/kg. Level of norepinephrine (NE), dopamine (DA), dihydroxyphenylacetic acid (DOPAC), serotonin (5-HT) and hydroxy indole acetic acid (HIAA) were measured in frontal cortex and brain stem after VW treatment at the dose of 200mg/kg. NE and 5HT level were decreased significantly in both frontal cortex and brain stem. DA and HIAA level significantly decreased only in cortex. DOPAC level was not changed in any brain region studied. In conclusion it can be said that VW water extract has a sleep quality improving effect which may be dependent upon levels of monoamines in cortex and brainstem. 相似文献
90.
Simonin J Vernekar SK Thompson AJ Hothersall JD Connolly CN Lummis SC Lochner M 《Bioorganic & medicinal chemistry letters》2012,22(2):1151-1155
The synthesis, photophysical and biological characterization of a small library of fluorescent 5-HT(3) receptor ligands is described. Several of these novel granisetron conjugates have high quantum yields and show high affinity for the human 5-HT(3)AR. 相似文献