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排序方式: 共有763条查询结果,搜索用时 31 毫秒
31.
Sin JI Kim JJ Arnold RL Shroff KE McCallus D Pachuk C McElhiney SP Wolf MW Pompa-de Bruin SJ Higgins TJ Ciccarelli RB Weiner DB 《Journal of immunology (Baltimore, Md. : 1950)》1999,162(5):2912-2921
IL-12 has been shown to enhance cellular immunity in vitro and in vivo. Recent reports have suggested that combining DNA vaccine approach with immune stimulatory molecules delivered as genes may significantly enhance Ag-specific immune responses in vivo. In particular, IL-12 molecules could constitute an important addition to a herpes vaccine by amplifying specific immune responses. Here we investigate the utility of IL-12 cDNA as an adjuvant for a herpes simplex virus-2 (HSV-2) DNA vaccine in a mouse challenge model. Direct i.m. injection of IL-12 cDNA induced activation of resting immune cells in vivo. Furthermore, coinjection with IL-12 cDNA and gD DNA vaccine inhibited both systemic gD-specific Ab and local Ab levels compared with gD plasmid vaccination alone. In contrast, Th cell proliferative responses and secretion of cytokines (IL-2 and IFN-gamma) and chemokines (RANTES and macrophage inflammatory protein-1alpha) were significantly increased by IL-12 coinjection. However, the production of cytokines (IL-4 and IL-10) and chemokine (MCP-1) was inhibited by IL-12 coinjection. IL-12 coinjection with a gD DNA vaccine showed significantly better protection from lethal HSV-2 challenge compared with gD DNA vaccination alone in both inbred and outbred mice. This enhanced protection appears to be mediated by CD4+ T cells, as determined by in vivo CD4+ T cell deletion. Thus, IL-12 cDNA as a DNA vaccine adjuvant drives Ag-specific Th1 type CD4+ T cell responses that result in reduced HSV-2-derived morbidity as well as mortality. 相似文献
32.
Estrogen has a profound impact on human physiology and affects numerous genes. The classical estrogen reaction is mediated by its receptors (ERs), which bind to the estrogen response elements (EREs) in target gene's promoter region. Due to tedious and expensive experiments, a limited number of human genes are functionally well characterized. It is still unclear how many and which human genes respond to estrogen treatment. We propose a simple, economic, yet effective computational method to predict a subclass of estrogen responsive genes. Our method relies on the similarity of ERE frames across different promoters in the human genome. Matching ERE frames of a test set of 60 known estrogen responsive genes to the collection of over 18,000 human promoters, we obtained 604 candidate genes. Evaluating our result by comparison with the published microarray data and literature, we found that more than half (53.6%, 324/604) of predicted candidate genes are responsive to estrogen. We believe this method can significantly reduce the number of testing potential estrogen target genes and provide functional clues for annotating part of genes that lack functional information. 相似文献
33.
Proteome analysis of rice blast fungus (Magnaporthe grisea) proteome during appressorium formation 总被引:1,自引:0,他引:1
We used two-dimensional gel electrophoresis (2-DE) to identify the proteins that are induced in the rice blast fungus Magnaporthe grisea during appressorium formation. Proteins were extracted from conidia that had germinated on hydrophilic glass plates or from germinated and appressoria-forming conidia on leaf wax-coated hydrophobic glass plates after 4, 8, and 12 h of incubation. Differentially expressed protein spots during appressorium formation were confirmed from gels after 2-DE analysis where proteins had been labeled with (35)S methionine and stained with silver. Internal amino acid sequencing identified five proteins among several proteins induced during appressorium formation. Two denoted as M. grisea proteasome homolgues (MgP1 and MgP5) were 20S proteasome alpha subunits. The remaining three were scytalone dehydratase (SCD), and serine carboxypeptidase Y (CPY). None of the five have been reported previously in the rice blast fungus apart from SCD. We further investigated the role the alpha subunit of 20S proteasome plays in appressorium formation. We confirmed by Western blot analysis that MgP5 is highly expressed during appressorium formation and found that it is also markedly induced by nitrogen- and carbon-starvation, in particular by the former. These observations suggest that the 20S proteasome may be involved in remobilizing storage proteins, which then help to build the appressorium. Thus, fungal proteome analysis may provide important clues about developmental changes such as the generation of the appressorium. 相似文献
34.
Prediction of human response to drugs or chemicals is difficult as a result of the complexity of living organisms. We describe an in vitro model that can realistically and inexpensively study the adsorption, distribution, metabolism, elimination, and potential toxicity (ADMET) of chemicals. A microscale cell culture analog (microCCA) is a physical replica of the physiologically based pharmacokinetics (PBPK) model. Such a microfabricated device consists of a fluidic network of channels to mimic the circulatory system and chambers containing cultured mammalian cells representing key functions of animal "organ" systems. This paper describes the application of a two-cell system, four-chamber microCCA ("lung"-"liver"-"other tissue"-"fat") device for proof-of-concept study using naphthalene as a model toxicant. Naphthalene is converted into reactive metabolites (i.e., 1,2-naphthalenediol and 1,2-naphthoquinone) in the "liver" compartment, which then circulate to the "lung" depleting glutathione (GSH) in lung cells. Such microfabricated in vitro devices are potential human surrogates for testing chemicals and pharmaceutics for toxicity and efficacy. 相似文献
35.
36.
A rapid biosensor chip assay for measuring of telomerase activity using surface plasmon resonance 总被引:2,自引:0,他引:2 下载免费PDF全文
Maesawa C Inaba T Sato H Iijima S Ishida K Terashima M Sato R Suzuki M Yashima A Ogasawara S Oikawa H Sato N Saito K Masuda T 《Nucleic acids research》2003,31(2):e4-E4
Considerable interest has been focused on telomerase because of its potential use in assays for cancer diagnosis, and for anti-telomerase drugs as a strategy for cancer chemotherapy. A number of assays based on the polymerase chain reaction (PCR) have been developed for evaluation of telomerase activity. To overcome the disadvantages of the conventional telomerase assay [telomeric repeat amplification protocol (TRAP)] related to PCR artifacts and troublesome post-PCR procedures, we have developed a telomeric repeat elongation (TRE) assay which directly measures telomerase activity as the telomeric elongation rate by biosensor technology using surface plasmon resonance (SPR). 5′-Biotinylated oligomers containing telomeric repeats were immobilized on streptavidin-pretreated dextran sensor surfaces in situ using the BIACORE apparatus. Subsequently, the oligomers associated with the telomerase extracts were elongated in the BIACORE apparatus. The rate of TRE was calculated by measuring the SPR signals. We examined elongation rates by the TRE assay in 18 cancer and three normal human fibroblast cell lines, and 12 human primary carcinomas and matching normal tissues. The elongation rates increased in a concentration- and time-dependent manner. Those of cancer cells were two to 10 times higher than fibroblast cell lines and normal tissues. Telomerase activities and its inhibitory effects of anti-telomerase agents as measured by both the TRE and TRAP assays showed a good correlation. Our assay allows precise quantitative comparison of a wide range of human cells from somatic cells to carcinoma cells. TRE assay is suitable for practical use in the assessment of telomerase activity in preclinical and clinical trials of telomerase-based therapies, because of its reproducibility, rapidity and simplicity. 相似文献
37.
Gene and protein expression in the epididymis of infertile c-ros receptor tyrosine kinase-deficient mice 总被引:2,自引:0,他引:2
Cooper TG Wagenfeld A Cornwall GA Hsia N Chu ST Orgebin-Crist MC Drevet J Vernet P Avram C Nieschlag E Yeung CH 《Biology of reproduction》2003,69(5):1750-1762
Transgenic male mice bearing inactive mutations of the receptor tyrosine kinase c-ros lack the initial segment of the epididymis and are infertile. Several techniques were applied to determine differences in gene expression in the epididymal caput of heterozygous fertile (HET) and infertile homozygous knockout (KO) males that may explain the infertility. Complementary DNA arrays, gene chips, Northern and Western blots, and immunohistochemistry indicated that some proteins were downregulated, including the initial segment/proximal caput-specific genes c-ros, cystatin-related epididymal-spermatogenic (CRES), and lipocalin mouse epididymal protein 17 (MEP17), whereas other caput-enriched genes (glutathione peroxidase 5, a disintegrin and metalloproteinase [ADAM7], bone morphogenetic proteins 7 and 8a, A-raf, CCAAT/enhancer binding protein beta, PEA3) were unchanged. Genes normally absent from the initial segment (gamma-glutamyltranspeptidase, prostaglandin D2 synthetase, alkaline phosphatase) were expressed in the undifferentiated proximal caput of the KO. More distally, lipocalin 2 (24p3), CRISP1 (formerly MEP7), PEBP (MEP9), and mE-RABP (MEP10) were unchanged in expression. Immunohistochemistry and Western blots confirmed the absence of CRES in epididymal tissue and fluid and the continued presence of CRES in spermatozoa of the KO mouse. The glutamate transporters EAAC1 (EAAT3) and EAAT5 were downregulated and upregulated, respectively. The genes of over 70 transporters, channels, and pores were detected in the caput epididymidis, but in the KO, only three were downregulated and six upregulated. The changes in these genes could affect sperm function by modifying the composition of epididymal fluid and explain the infertility of the KO males. These genes may be targets for a posttesticular contraceptive. 相似文献
38.
The hitherto unknown (-)- and (+)-1-benzylcyclohexan-1,2-diamine hydrochlorides 4a. HCl and 4b. HCl were synthesized by means of diastereoselective alpha-iminoamine rearrangement with subsequent imine reduction and hydrogenolysis. The relative trans-configuration as well as the absolute (1S,2R) and (1R,2S) configurations of 4a and 4b, respectively, were elucidated on the basis of an X-ray analysis of 3b. HCl. The enantiomeric excess (ee) values of the title compounds (>99%) were determined by chiral HPLC on a Chirex (D) Penicillamine column. 相似文献
39.
Gemmell NJ Sin FY 《BioEssays : news and reviews in molecular, cellular and developmental biology》2002,24(3):275-279
The human Y chromosome contains very low levels of nucleotide variation. It has been variously hypothesized that this invariance reflects historic reductions in the human male population, a very recent common ancestry, a slow rate of molecular evolution, an inability to evolve adaptively, or frequent selective sweeps acting on genes borne on the Y chromosome. We propose an alternative theory in which human Y chromosome evolution is driven by mutations in the maternally inherited mitochondrial genome, which impair male fertility and ultimately lead to a reduction in the effective population size (N(e)) and consequently the variability of the Y chromosome. 相似文献
40.
The lytic cycle of Epstein-Barr virus is associated with decreased expression of cell surface major histocompatibility complex class I and class II molecules 下载免费PDF全文
Human herpesviruses utilize an impressive range of strategies to evade the immune system during their lytic replicative cycle, including reducing the expression of cell surface major histocompatibility complex (MHC) and immunostimulatory molecules required for recognition and lysis by virus-specific cytotoxic T cells. Study of possible immune evasion strategies by Epstein-Barr virus (EBV) in lytically infected cells has been hampered by the lack of an appropriate permissive culture model. Using two-color immunofluorescence staining of cell surface antigens and EBV-encoded lytic cycle antigens, we examined EBV-transformed B-cell lines in which a small subpopulation of cells had spontaneously entered the lytic cycle. Cells in the lytic cycle showed a four- to fivefold decrease in cell surface expression of MHC class I molecules relative to that in latently infected cells. Expression of MHC class II molecules, CD40, and CD54 was reduced by 40 to 50% on cells in the lytic cycle, while no decrease was observed in cell surface expression of CD19, CD80, and CD86. Downregulation of MHC class I expression was found to be an early-lytic-cycle event, since it was observed when progress through late lytic cycle was blocked by treatment with acyclovir. The immediate-early transactivator of the EBV lytic cycle, BZLF1, did not directly affect expression of MHC class I molecules. However, BZLF1 completely inhibited the upregulation of MHC class I expression mediated by the EBV cell-transforming protein, LMP1. This novel function of BZLF1 elucidates the paradox of how MHC class I expression can be downregulated when LMP1, which upregulates MHC class I expression in latent infection, remains expressed in the lytic cycle. 相似文献