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91.
92.
Infections with the parasitic helminth, Nippostrongylus brasiliensis, cause changes in rat small intestinal goblet cell mucin, particularly in the peripheral sugar residues of oligosaccharide. These changes may correlate with expulsion. In this study, we examined changes in mucin oligosaccharides caused by primary infection and reinfection with N. brasiliensis, using two monoclonal antibodies, HCM31 and PGM34, that react with sialomucin and sulfomucin, respectively. Enzyme-linked immunosorbent assay of jejunal mucins showed that the relative reactivity of mucins with HCM31, but not PGM34, increased up to 16 days after primary infection and 6 days after reinfection, the times when the worms were expelled from the rats. Immunohistochemical studies confirmed that goblet cells stained with HCM31 greatly increased at the time of worm expulsion. These results indicate that the marked increase observed in HCM31-reactive sialomucins may be related to expulsion of the worms. 相似文献
93.
Hideki Shiba Tsuyoshi Fujita Naomi Doi Shigeo Nakamura Keiji Nakanishi Toshinobu Takemoto Takamune Hino Mitsuhide Noshiro Takeshi Kawamoto Hidemi Kurihara Yukio Kato 《Journal of cellular physiology》1998,174(2):194-205
The purpose of this study is to differentiate roles of several growth factors and cytokines in proliferation and differentiation of pulp cells during development and repair. In human pulp cell cultures, laminin and type I collagen levels per cell remained almost constant during the whole culture period (22 days). On the other hand, secreted protein, acidic and rich in cysteine (SPARC/osteonectin) and alkaline phosphatase (ALPase) levels markedly increased after the cultures reached confluence. Laminin and type I collagen, as well as fibronectin, stimulated the spreading of pulp cells within 1 h. Adding transforming growth factor-β (TGF-β) decreased laminin and ALPase levels, whereas it increased SPARC and fibronectin levels 3- to 10-fold. Western and Northern blots showed that TGF-β enhanced SPARC synthesis at the protein and mRNA levels. Basic fibroblast growth factor (bFGF) decreased type I collagen, laminin, SPARC, and ALPase levels without changing the fibronectin level. Platelet-derived growth factor (PDGF) selectively decreased laminin, SPARC, and ALPase levels. Epidermal growth factor (EGF) also decreased SPARC and ALPase levels. Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) decreased type I collagen and laminin levels, and abolished SPARC and ALPase syntheses. Of these peptides, bFGF and PDGF showed the greatest stimulation of [3H]thymidine incorporation into DNA. TGF-β, EGF, and TNF-α had less effect on DNA synthesis, whereas IL-1β inhibited DNA synthesis. These findings demonstrated that TGF-β, bFGF, EGF, PDGF, TNF-α, and IL-1β have characteristically different patterns of actions on DNA, laminin, type I collagen, fibronectin, ALPase, and SPARC syntheses by pulp cells. J. Cell. Physiol. 174:194–205, 1998. © 1998 Wiley-Liss, Inc. 相似文献
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Stable isotopic structure of aquatic ecosystems 总被引:1,自引:0,他引:1
Isotopic, biogeochemical and ecological structure can provide a new dimension for understanding material flows, and the simultaneous
function and structure of an ecosystem. Distributions ofδ
13C andδ
15N for biogenic substances in the Nanakita river estuary involving Gamo lagoon in Japan were investigated to construct isotope
biogeochemical and ecological structure for assessing fate and transfer of organic matter, and food web structure. The isotopic
framework of the ecosystem was successfully described in aδ
15N–δ
13C map. In this estuary the variations of isotope ratios of biogenic substances were clearly explained by the mixing of land-derived
organic matter, and marine-derived organic matter.
A trophic-level effect of15N enrichment was clearly observed. Organisms were classified into three groups depending upon the contribution of land-derived
organic matter in a food chain. Almost all biota except mollusca in the lagoon depend on organic matter of marine origin.
The contributions of both land and marine organic matter were comparable for mollusca in the lagoon. 相似文献
98.
Growth inhibition and induction of differentiation and apoptosis mediated by sodium butyrate in caco-2 cells with algal glycolipids 总被引:2,自引:0,他引:2
Hossain Z Kurihara H Hosokawa M Takahashi K 《In vitro cellular & developmental biology. Animal》2005,41(5-6):154-159
Summary Glycolipids should have potential effects as antitumor agents. However, very few studies have examined this property of digalactosyl
diacylglycerol (DGDG) and sulfoquinovosyl diacylglycerol (SQDG) on colon cancer cells. Cell viability was determined every
24 h with sodium 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2, 4-disulfophenyl)-2H-tetrazolium dye reduction assay up to 72 h. Alkaline phosphatase activity was measured for assessing cell differentiation.
Apoptosis was tested with enzyme-linked immunosorbent assay analysis. Growth of Caco-2 cells was inhibited apparently at 48
h after addition of SQDG and at 72 h with DGDG. Alkaline phosphatase activity of Caco-2 cells obviously increased in combination
with DGDG or SQDG and sodium butyrate (NaBT) at 72 h, indicating that DGDG and SQDG enhanced cell differentiation induced
with NaBT. An increased enrichment factor was found when the cell was treated in combination with DGDG or SQDG and NaBT. These
results strongly suggest that DGDG and SQDG should be considered as the leading compounds of potentially useful colon cancer
chemotherapy agents when NaBT is combined. 相似文献
99.
100.
Hepatocyte transplantation is considered a potential treatment for liver diseases and a bridge for patients awaiting liver transplantation, but its application has been hampered by a limited supply of hepatocytes. Embryonic stem (ES) cells established from early mouse and human embryos are pluripotent, and proliferate indefinitely in an undifferentiated state in vitro. Since differentiation from ES cells seems to recapitulate early embryonic development, if hepatocytes could be efficiently generated in vitro, ES cells might become a source of transplantable hepatocytes for cell replacement therapy. Hepatocytes have been generated from ES cells in vitro, and the hepatocytes differentiated from ES cells have been found to express many hepatocyte-related genes and perform hepatic functions. However, it remains unclear whether the hepatocytes differentiated from ES cells are derived from definitive endoderm or primitive endoderm. Because visceral endoderm, which expresses many hepatocyte-related genes, is derived from primitive endoderm and is fated to form extraembryonic yolk sac tissues, not to form hepatocytes, ES cells must be directed to a definitive endoderm lineage in vitro. This article discusses the differentiation of ES cells into hepatocytes in vitro in comparison with early embryogenesis, and describes the efficacy of ES cell-derived hepatocyte transplantation. 相似文献