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51.
Mg2+ at micromolar concentrations greatly enhanced [3H]N-(1-(2-thienyl)cyclohexyl)-3,4-piperidine ([3H]TCP) binding to well-washed rat cortical membranes, whereas [3H]TCP binding was inhibited by Mg2+ at concentrations higher than 1 mM. In the presence of either L-glutamate (10 microM) or glycine (10 microM), 30 microM Mg2+ caused further stimulation of [3H]TCP binding, suggesting that a high-affinity site for Mg2+ is distinct from the glutamate or glycine binding site. These findings indicate that Mg2+ acts on at least two different recognition sites, e.g. a novel high-affinity site for Mg2+ which stimulates [3H]TCP binding and the Mg2+ recognition site located within the ion channel. 相似文献
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The effects of so-called antistress music tapes on reduction of mental stress were examined using Cox and Mackay's SACL, Japanese edition (J-SACL). Fifty-two subjects were exposed to experimentally induced stressful situations and the J-SACL was administered before and after this stress exposure. The results indicated that: (1) music tapes in general could reduce both the stress and arousal factors of the J-SACL; (2) however, differential effects in stress reduction of antistress music tapes were not demonstrated; (3) stress-reducing effects were more prominent in stress than in arousal factors. 相似文献
54.
Tado M Abe T Hatta T Ishikawa M Nakada S Yokota T Takaku H 《Antiviral chemistry & chemotherapy》2001,12(6):353-358
We have shown previously that the 5'-capped short phosphodiester RNA fragments, Cap decoy, (Gm 12 nt) are potent inhibitors of influenza virus RNA polymerase gene expression. Here we investigate the modified capped RNA derivative containing phosphorothioate oligonucleotides (Cap decoy) as a potential influenza virus RNA polymerase inhibitor. The modified 5'-capped short phosphorothioate RNA fragments (Gms 12-15 nt) with the 5'-capped structure (m7GpppGm) were synthesized by T7 RNA polymerase. The 5'-capped short RNA fragments (Gms 12-15 nt) were encapsulated in liposome particulates and tested for their inhibitory effects on influenza virus RNA polymerase gene expression in the clone 76 cells. The 12-15 nt long Gms RNA fragments showed highly inhibitory effects. By contrast, the inhibitory effects of the 13 nt long short RNA fragments (Gm 13 nt) were considerably less in comparison with the 5'-capped short phosphorothioate RNA fragments (Gms 12-15 nt). In particular, the various Gms RNA chain lengths showed no significant differences in the inhibition of influenza virus RNA polymerase gene expression. Furthermore, the capped RNA with a phosphorothioate backbone was resistant to nuclease activity. These phosphorothioate RNA fragments exhibited higher inhibitory activity than the 5'-capped short RNA fragments (Gm 12 nt). These decoys may prove to be useful in anti-influenza virus therapeutics. 相似文献
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Hatta E Maruyama R Marshall SJ Imamura M Levi R 《The Journal of pharmacology and experimental therapeutics》1999,288(3):919-927
We previously reported that bradykinin (BK; 1-1000 nM) facilitates norepinephrine (NE) release from cardiac sympathetic nerves. Because BK production increases in myocardial ischemia, endogenous BK could foster NE release and associated arrhythmias. We tested this hypothesis in guinea pig and human myocardial ischemia models. BK administration (100 nM) markedly enhanced exocytotic and carrier-mediated NE overflow from guinea pig hearts subjected to 10- and 20-min ischemia/reperfusion, respectively. Ventricular fibrillation invariably occurred after 20-min global ischemia; BK prolonged its duration 3-fold. The BK B2 receptor antagonist HOE140 (30 nM) blocked the effects of BK, whereas the B1 receptor antagonist des-Arg9-Leu8-BK (1 microM; i.e., 2.5 x pA2) did not. When serine proteinase inhibitors (500 KIU/ml aprotinin and 100 microg/ml soybean trypsin inhibitor) were used to prevent the formation of endogenous BK, NE overflow and reperfusion arrhythmias were diminished. In contrast, when kininase I and II inhibitors (DL-2-mercaptomethyl-3-guanidinoethylthiopropanoic acid and enalaprilat, each 1 microM) were used to prevent the degradation of endogenous BK, NE overflow and reperfusion arrhythmias were enhanced. B2 receptor blockade abolished these effects but was ineffective if kininases were not inhibited. B2 receptor stimulation, by either exogenous or endogenous BK, also markedly enhanced carrier-mediated NE release in the human myocardial ischemia model; conversely, inhibition of BK biosynthesis diminished ischemic NE release. Because atherosclerotic heart disease impairs endothelial BK production, in myocardial ischemia BK could accumulate at sympathetic nerve endings, thus augmenting exocytotic and carrier-mediated NE release and favoring coronary vasoconstriction and arrhythmias. 相似文献
58.
Tomoko Hatta Yasunari Fujinaga Masumi Kadoya Hitoshi Ueda Hiroaki Murayama Masahiro Kurozumi Kazuhiko Ueda Michiharu Komatsu Tadanobu Nagaya Satoru Joshita Ryo Kodama Eiji Tanaka Tsuyoshi Uehara Kenji Sano Naoki Tanaka 《Journal of gastroenterology》2010,45(12):1263-1271
Background
To assess the degree of hepatic fat content, simple and noninvasive methods with high objectivity and reproducibility are required. Magnetic resonance imaging (MRI) is one such candidate, although its accuracy remains unclear. We aimed to validate an MRI method for quantifying hepatic fat content by calibrating MRI reading with a phantom and comparing MRI measurements in human subjects with estimates of liver fat content in liver biopsy specimens.Methods
The MRI method was performed by a combination of MRI calibration using a phantom and double-echo chemical shift gradient-echo sequence (double-echo fast low-angle shot sequence) that has been widely used on a 1.5-T scanner. Liver fat content in patients with nonalcoholic fatty liver disease (NAFLD, n = 26) was derived from a calibration curve generated by scanning the phantom. Liver fat was also estimated by optical image analysis. The correlation between the MRI measurements and liver histology findings was examined prospectively.Results
Magnetic resonance imaging measurements showed a strong correlation with liver fat content estimated from the results of light microscopic examination (correlation coefficient 0.91, P < 0.001) regardless of the degree of hepatic steatosis. Moreover, the severity of lobular inflammation or fibrosis did not influence the MRI measurements.Conclusions
This MRI method is simple and noninvasive, has excellent ability to quantify hepatic fat content even in NAFLD patients with mild steatosis or advanced fibrosis, and can be performed easily without special devices. 相似文献59.
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