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91.
We have previously demonstrated that the exposure of mouse microvascular endothelium (MME) to tumor necrosis factor-alpha (TNF) led to the increased binding of mouse mastocytoma cells (P815) to endothelial monolayers (Bereta et al., in press). In the current study we examined the possible involvement of protein kinases in TNF signal transduction in the endothelial cells. PKA does not appear to play a role in the potentiation of binding by TNF. We found that the TNF-generated signal is inhibited by H-7 and sangivamycin, but not by staurosporine. TNF did not cause translocation of PKC to the cell membrane and its effect could not be completely mimicked by PMA nor by PMA in the presence of calcium-raising agents. Thus, we concluded that the "classical" PKC pathway is not completely responsible for TNF signalling in this system. We also found that staurosporine itself strongly enhanced adhesion of tumor cells to endothelium, utilizing a mechanism distinct from that of TNF. Although the data provide evidence for the role of kinases in the effect of TNF on binding of tumor cells to MME, this role appears to be a complex one. 相似文献
92.
Henrika G. M. Tiedink Laura H. J. De Haan Wim M. F. Jongen Jan H. Koeman 《Cell biology and toxicology》1991,7(4):371-386
4-chloro-methoxyindole is a naturally occurring compound in Vicia faba which can easily react with nitrite to form a N-nitroso compound. In this in vitro study, the potential genotoxic effects of nitrosated 4-chloro-6-methoxyindole and its structural analogue 4-chloroindole were evaluated for the first time by using both Salmonella and Chinese hamster V79 cells. Additionally, the inhibition of gap junctional intercellular communication in V79 cells by these compounds was determined; this is a validated parameter for tumor-promoting activity. Most assays were also performed with nitrosated indole-3-acetonitrile, a naturally occurring compound in brassicas. Both nitrosated chloroindoles were highly mutagenic to Salmonella typhimurium TA100 without the need of exogenous metabolic activation and were potent inducers of Sister Chromatid Exchanges. Nitrosated indole-3-acetonitrile generated the same effects, although at much higher concentrations. Equivocal results were obtained for the nitrosated chloroindoles in a forward mutation assay using the hypoxanthine guaninephosphoribosyltransferase locus. All nitrosated indole compounds significantly inhibited gap junctional intercellular communication. These results indicate that nitrosated chloroindoles and nitrosated indole-3-acetonitrile should be considered as mutagens and agents with potential tumor-promoting capacity.Abbreviations BrdU
5-bromo-2-deoxyuridine
- 4Cl
4-chloroindole
- 4C6MI
4-chloro-6-methoxy-indole
- DMSO
dimethyl sulfoxide
- EBSS
Earle's balanced salt solution
- EMS
ethyl methanesulfonate
- GJIC
gap junctional intercellular communication
- HBSS
Hanks balanced salt solution
- HGPRT
hypoxanthine guaninephosphoribosyl transferase
- I3A
indole-3-acetonitrile
- MNNG
1-methyl-1-nitroso-3-nitroguanidine
- NOC
N-nitroso compounds
- NQO
4-nitroquinolone-N-oxide
- SCE
sister chromatid exchange
- 6TG
6-thioguanine
- TPA
12-O-tetradecanoylphorbol-13-acetate 相似文献
93.
The circular dichroism (CD) spectrum of tumor necrosis factor-α has been measured into the vacuum UV to 168 nm. Analysis of the CD for secondary structure is in good agreement with X-ray diffraction results, but the analysis is somewhat unstable. Adding the CD of this protein together with its X-ray determined secondary structure to the basis set should improve subsequent analyses of CD spectra for other all-β proteins. 相似文献
94.
Clinical studies with TNF 总被引:4,自引:0,他引:4
95.
96.
The effect of implantation of Ehrlich ascites tumor (EAT) cells of creatine distribution was investigated. It was also studied how depletion of creatine by feeding creatine-analogue β-guanidinopropionic acid (β-GPA) affects the growth of EAT cells in mice. Enhanced mobilization of creatine from host tissues to EAT cells against a greater concentration gradient was observed. The creatine (but not creatinine) level in blood plasma was lowered to 22% of the normal value by β-GPA feeding alone and assimilation of 14C-creatine into EAT cells was inhibited. The growth of EAT cells was significantly reduced and the duration of survival of mice after implantation of EAT cells was extended when the creatine concentration was decreased. A decrease in daily food consumption and the degree of muscle atrophy after implantation of EAT cells was less in β-GPA than control groups. In the creatine-depleted mice, the rate of increase in total EAT cell number and the volume of abdominal ascites were approximately half of the control values, and more dead EAT cells were observed. These results suggest that supplementation of β-GPA inhibits creatine transfer to EAT cells and reduces the growth of cancer cells. 相似文献
97.
Kiyoshi Ohkawa Takashi Hatano Naoko Takizawa Kazue Shinmoto Kyosuke Yamada Makoto Matsuda Koji Takada Yutaka Tsukada 《In vitro cellular & developmental biology. Animal》1992,28(6):449-454
Summary A human yolk sac tumor cell line, TG1, which was established from a testicular yolk sac tumor, was found to replicate continuously
in a chemically defined medium supplemented with Na2SeO3 (ISRPMI). TG1 produced several plasma proteins and growth factors: albumin, alpha-fetoprotein (AFP), ferritin, carcinoembryonic
antigen, beta-2-microglobulin, polyamine, neuron specific enolase, tissue polypeptide antigen, transferrin (Tf), epidermal
growth factor, and platelet derived growth factor. By analysis of lectin (LcHA)-affinity electrophoresis, to examine the microheterogeneity
of carbohydrate chains of synthetic glycoproteins, TG1 cells cultured with ISRPMI produced only LcHA reactive Tf and AFP based
on core fucose attached to asparagine-linkedN-acetylglucosamine residues instead of LcHA-nonreactive Tf and AFP produced by TG1 cells cultured with fetal bovine serum
(FBS)-containing medium.α1-6 Fucosyltransferase activity was significantly greater in the TG1 cells cultured with ISRPMI (39.9±1.5 pmol · h−1 · mg−1 protein) than cultured with FBS-containing media (18.2±1.2 pmol · h−1 · mg−1 protein). These results have indicated that the selective increase ofα1-6 fucosyltransferase occurred when the cells were cultured with the FBS-free synthetic media. 相似文献
98.
99.
Jason Yang Raphael Guzman James Richards S. Nandi 《In vitro cellular & developmental biology. Plant》1980,16(6):502-506
Summary Mammary tumor epithelial cells from BALB/cfC3H mice were dispersely embedded inside the collagen gels in Ham's F-12 medium
containing horse serum. A sustained cell growth leading to a 5- to 10-fold increase in cell number over initial level was
observed in less than 2 weeks. The extent of this growth was found to be dependent on serum concentration. However, addition
of various protein and steroid hormones, both singly and in combination, to low-serum-containing medium failed to achieve
a comparable level of growth to that promoted by higher serum concentration. Mammary tumor cells can now be consistently propagated
in primary culture.
This investigation was supported by Grants CA05388 and CA09041 awarded by the National Cancer Institute, Department of Health,
Education and Welfare, and by cancer research funds of the University of California. 相似文献
100.
Asynchronous 9L cells were separated into relatively homogeneously-sized populations using centrifugal elutriation with both
a conventional collection method and a long collection method. A substantial increase in the homogeneity of the volume distributions
and in the degree of synchrony of the separated fractions was obtained using the long collection method. Autoradiographic
data indicated that fractions containing ≥97% G1 cells, ≥80% S cells, and 70–75% G2 cells could be routinely recovered with this procedure. Recovery in these fractions varied from 5 to 8% of the total number
of cells elutriated. The colony forming efficiency (CFE) of cells from fractions representing each phase of the cell cycle
was a constant 60–70%, which was comparable to the 60–80% usually found for asynchronous 9L cells. The percentage of cells
in the G1, S, and G2 phases in the elutriated fractions was more accurately determined from the volume distribution than from computer fits of
the DNA histogram obtained from flow cytometry. In general, the degree of synchrony was related to the coefficient of variation
(CV) of the volume distributions of the elutriated fractions. The CV was about 14% for all elutriated fractions. When the
≥97% G1 population was allowed to progress to S and G2, the CVs were about 17 and 20.2%, respectively. Thus, the best nonperturbing method for obtaining synchronous 9L cells in
the S or G2 phases was direct elutriation with the long collection method. 相似文献