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排序方式: 共有808条查询结果,搜索用时 14 毫秒
791.
盐酸普鲁卡因经皮离子导入的研究 总被引:2,自引:2,他引:2
目的:考察盐酸普鲁卡因的离子导入与电流强度、药物浓度的关系。方法:测定不同的电流强度、不同的药物浓度的离子导入增渗倍数(ER)。结果:固定药物浓度,电流强度为0.1,0.2和0.3mA时的ER值分别为68.99和127。固定电流强度0.2mA,药物浓度为0.0151,0.0304和0.0605g/100ml时的ER值分别为95,99和98,结论:离子导入可以显著提高药物渗透速率,增渗倍数(ER)随 相似文献
792.
Metabolic competence and susceptibility of intestinal epithelium to genotoxic injury during regeneration 总被引:1,自引:1,他引:1
Patel HR; Hewer A; Phillips DH; Hayes JD; Wolf CR; Campbell FC 《Carcinogenesis》1997,18(11):2171-2177
The carcinogenic potency of many mutagens is increased in conditions of
tissue regeneration. This involves fundamental changes of cellular division
and differentiation, in intestinal epithelium. However, effects on
epithelial capacity for carcinogen metabolism and susceptibility to
genotoxic injury are unknown. Using a novel rat model, this study assessed
expression of cytochrome P450 mono- oxygenases (Cyps), glutathione
S-transferases (GSTs) and uridine diphosphoglucuronosyl transferase (UGT)
in intestinal epithelium during sequential stages of regeneration. Enzyme
induction and DNA adduct formation were also assessed after benzo[a]pyrene
(BaP) exposure. Control assays were carried out in normal intestinal
epithelium. Fewer phase I and II xenobiotic metabolizing enzymes were
expressed in regenerating intestinal epithelium than in normal control
intestinal epithelium (GSTA3, UGT in regeneration vs Cyp2B, GSTA1/2, GSTA4,
GSTP1, UGT in control). Benzo[a]pyrene induced GSTA3 and UGT in
regeneration vs Cyp1A, Cyp2B, GSTA1/2, GSTA3, GSTA4, GSTP1 and UGT in
control normal intestinal epithelium. Benzo[a]pyrene induced low levels of
GSTA3 in early regenerating intestinal epithelium but induction increased
by >2- fold at late stage regeneration. Higher levels of benzo[a]pyrene
7,8- diol-9,10-epoxide (BPDE) DNA adducts were formed at early stages of
regeneration, than at later stages. Intestinal epithelium displayed reduced
metabolic competence and differential susceptibility to genotoxic injury
from BaP, during regeneration.
相似文献
793.
Jacques-André St-Pierre Yvan Dumont Dominique Nouel Herbert Herzog Edith Hamel Rémi Quirion 《British journal of pharmacology》1998,123(2):183-194
- Neuropeptide Y (NPY) and NPY receptors are most abundant in the hippocampal formation where they modulate cognitive functions. Expression of NPY receptors in rat cultured primary hippocampal cells was investigated in the present study by use of combined molecular, pharmacological and immunohistochemical approaches, including the cloning of the rat Y2 receptor described here for the first time.
- More than 70% of the hippocampal neurones were endowed with [125I]-[Leu31,Pro34]PYY Y1-like receptor silver grain accumulations and Y1 receptor immunostaining. These radio- and immuno-labelling signals were distributed over cell bodies and processes of bipolar, stellate and pyramidal-like neuronal cells, as confirmed by neurone-specific enolase and MAP-2 staining.
- Competition binding profiles revealed that specific [125I]-[Leu31,Pro34]PYY binding was competitively displaced according to a ligand selectivity pattern prototypical of the Y1 receptor sub-type with [Leu31,Pro34]substituted NPY/PYY analogues>>C-terminal fragments=pancreatic polypeptides, with the non-peptide antagonist BIBP3226 being most potent. This profile excludes the possible labelling by [125I]-[Leu31,Pro34]PYY of the newly cloned Y4, Y5 and Y6 receptors.
- The expression of the genuine Y1 receptor was confirmed by RT–PCR in hippocampal cultures. In contrast, negligible levels of Y2-like/[125I]-PYY3–36 binding were detected in these cultures in spite of the presence of its mRNA, as characterized by RT–PCR. The expression of both the Y1 and the Y2 receptor mRNAs was also noted in normal embryonic hippocampal tissues showing that signals expressed in cultured neurones were also present in utero.
- Taken together, these results suggest that the Y1 receptor subtype may be of critical importance in the normal functioning of the rat hippocampus, especially during brain development and maturation.
794.
喙果绞股蓝中皂甙成分的研究 总被引:1,自引:0,他引:1
首次从喙果绞股蓝(Gymostemma yixingense CY Wu et SK Chen)中分得四个皂甙成分(Ⅰ~Ⅳ),经理化常数测定、光谱解析和化学方法确定了它们的结构。其中Ⅰ为新化合物,命名为喙果皂甙A(yixinosideA),Ⅱ,Ⅲ和Ⅳ分别鉴定为绞股蓝皂甙XLIVXLII(gypensideXLIV,XLII)和具明显调脂作用的人参皂甙Rb1(ginsenosideRb1)。此外,Ⅰ经酸水解得到一新皂甙元1β-羟基人参二醇(1β-hydroxylpanaxadiol)(Ⅴ)和一新次级甙,命名为喙果皂甙B(yixinosideB,VI)。 相似文献
795.
796.
797.
F B Jolicoeur M A Gagne R Rivest A Drumheller S St-Pierre 《Pharmacology, biochemistry, and behavior》1991,38(2):463-465
In order to better characterize the neuroleptic properties of neurotensin, the dose-related effects of the peptide on stereotyped climbing, sniffing and licking induced by 0.6 mg/kg apomorphine were examined. The following doses of the peptide were injected intraventricularly 30 min prior to apomorphine administration: 0.9, 3.75, 30.0 and 60 micrograms. Results indicate that, whereas oro-facial stereotypies remained unaffected by the peptide, stereotyped climbing was significantly decreased with the two largest doses of neurotensin. These findings indicate that the profile of neurotensin's neurobehavioral effects is more akin to that of atypical than typical neuroleptics. 相似文献
798.
Marilyne Labrie Maria Claudia Vladoiu Andrée-Anne Grosset Louis Gaboury Yves St-Pierre 《Oncotarget》2014,5(17):7705-7721
There is a critical need to develop effective new strategies for diagnosis and treatment of ovarian cancer. In the present work, we investigated the expression of galectin-7 (gal-7) in epithelial ovarian cancer (EOC) cells and studied its functional relevance. Immunohistochemical analysis of gal-7 expression in tissue microarrays showed that while gal-7 was not detected in normal ovarian tissues, positive cytoplasmic staining of gal-7 was detected in epithelial cells in all EOC histological subtypes but was more frequent in high grade tumors and metastatic samples. Gal-7 expression correlated with a significant difference in the overall survival of patients with ovarian serous cystadenocarcinoma. Furthermore, using human EOC cell lines, we found that gal-7 expression was induced by mutant p53. Mechanistically, Matrigel invasion assays and live cell imaging showed that gal-7 increased the invasive behavior of ovarian cancer cells by inducing MMP-9 and increasing cell motility. EOC cells can also secrete gal-7. Recombinant human gal-7 kills Jurkat T cells and human peripheral T cells, suggesting that gal-7 also has immunosuppressive properties. Taken together, our study validates the clinical significance of gal-7 overexpression in ovarian cancer and provides a rationale for targeting gal-7 to improve the outcome of patients with this disease. 相似文献
799.
苦参碱对脂多糖/痤疮丙酸杆菌诱导的小鼠肝炎及产生肿瘤坏死因子的影响 总被引:4,自引:0,他引:4
用小鼠致死性肝炎模型和TNF体外诱生的方法,研究苦参碱(Mat)对脂多糖(lipopolysaccharides,LPS)诱导的经痤疮丙酸杆菌(propionibacterittmacnes,PA)预刺激的小鼠产生肿瘤坏死因子(TNF)以及致死性肝炎的影响。结果表明:Mat(10,50mg·kg ̄(-1),ip,bid×3d)可降低血清TNF和ALT水平及小鼠对LPS致死毒性的敏感性,并可在体外抑制LPS诱导的经PA预刺激的小鼠腹腔巨噬细胞释放TNF。提示Mat的保肝作用与其抑制TNF释放有关。 相似文献
800.
St-Pierre A Krishnan K Tardif R 《Journal of toxicology and environmental health. Part A》2003,66(23):2267-2280
Chloroacetic acids (monochloroacetic acid [MCA], dichloroacetic acid [DCA], and trichloroacetic acid [TCA]) and trihalomethanes (THMs: chloroform [CHCl(3)], bromodichloromethane [BDCM], dibromochloromethane [DBCM], and bromoform [TBM]) are common by-products of the chlorination of drinking water. The purpose of this study was to evaluate the influence of chloroacetic acids on the pharmacokinetics of trihalomethanes in the male Sprague-Dawley rat. In the first series of studies, groups of 5 animals were given, by intravenous injections, a single dose of 0.125 mmol/kg of one of the four THMs. Additional groups received a binary mixture containing 0.125 mmol/kg of a THM plus 0.125 mmol/kg of a chloroacetic acid. The venous blood concentrations of unchanged THMs were measured by headspace gas chromatography from 5 min to 6 h postadministration. The areas under the blood concentration versus time curves (AUCs) of CHCl(3), BDCM, and DBCM were increased by a factor of 3.5, 1.6, and 2, respectively, by coadministration of TCA. DCA coadministration resulted in an increase in the AUC of DBCM (x2.5) and TBM (x1.3), whereas MCA modified the Cmax (x1.5) and AUC (x1.8) of BDCM and the AUC of DBCM (x2.5). In the second series of experiments, animals received either a single dose of 0.03125 mmol/kg of one of the four THMs, a mixture containing 0.03125 mmol/kg of each of the four THMs (total dose = 0.125 mmol/kg), or a mixture containing 0.03125 mmol/kg of each of the four THMs plus 0.125 mmol/kg of either TCA or DCA. Results indicated that the AUCs of CHCl(3), BDCM, DBCM, and TBM were increased during coadministration compared to single administrations (+2.5-fold). Combined administration of the four THMs with TCA, and not DCA, resulted in an increase of the AUCs of THMs (CHCl(3): x11.7; BDCM, DBCM, and TBM: x3.9) and an increase in the Cmax of CHCl(3) (x1.9). Overall, these results indicate that, at the dose levels tested in this study, TCA alters the blood concentration profiles of THMs. 相似文献