全文获取类型
收费全文 | 22876篇 |
免费 | 2539篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 303篇 |
儿科学 | 699篇 |
妇产科学 | 494篇 |
基础医学 | 3342篇 |
口腔科学 | 430篇 |
临床医学 | 2864篇 |
内科学 | 4595篇 |
皮肤病学 | 256篇 |
神经病学 | 1624篇 |
特种医学 | 703篇 |
外国民族医学 | 1篇 |
外科学 | 3673篇 |
综合类 | 612篇 |
一般理论 | 24篇 |
预防医学 | 2443篇 |
眼科学 | 324篇 |
药学 | 1643篇 |
中国医学 | 11篇 |
肿瘤学 | 1426篇 |
出版年
2022年 | 201篇 |
2021年 | 418篇 |
2020年 | 265篇 |
2019年 | 403篇 |
2018年 | 474篇 |
2017年 | 384篇 |
2016年 | 349篇 |
2015年 | 406篇 |
2014年 | 576篇 |
2013年 | 842篇 |
2012年 | 1161篇 |
2011年 | 1203篇 |
2010年 | 650篇 |
2009年 | 567篇 |
2008年 | 965篇 |
2007年 | 1127篇 |
2006年 | 1027篇 |
2005年 | 988篇 |
2004年 | 962篇 |
2003年 | 961篇 |
2002年 | 874篇 |
2001年 | 696篇 |
2000年 | 734篇 |
1999年 | 644篇 |
1998年 | 289篇 |
1997年 | 275篇 |
1996年 | 219篇 |
1995年 | 232篇 |
1994年 | 213篇 |
1993年 | 173篇 |
1992年 | 532篇 |
1991年 | 507篇 |
1990年 | 486篇 |
1989年 | 454篇 |
1988年 | 402篇 |
1987年 | 381篇 |
1986年 | 381篇 |
1985年 | 376篇 |
1984年 | 268篇 |
1983年 | 232篇 |
1982年 | 179篇 |
1981年 | 147篇 |
1979年 | 290篇 |
1978年 | 213篇 |
1977年 | 151篇 |
1976年 | 152篇 |
1975年 | 143篇 |
1974年 | 168篇 |
1973年 | 171篇 |
1972年 | 171篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses... 相似文献
2.
3.
Cameron Duff 《Addiction (Abingdon, England)》2020,115(7):1378-1381
In 1998 Howard Parker, Judith Aldridge & Fiona Measham published Illegal Leisure, a ground‐breaking study of profound changes in British youth cultures in the 1990s, and the place of drugs and drug use in these upheavals. This work introduced the ‘normalization thesis’ to the social sciences, offering a novel vocabulary for re‐imagining the normative character of young people's attitudes towards and experiences of illicit drug use. Arriving at the dawn of the new century, the book offered a thoroughgoing re‐thinking of the character of youth cultures at a time of great social, cultural, economic and technological disruption. In so doing, the book deftly anticipated many of the most interesting currents of critical drug studies that followed. 相似文献
4.
Christopher D Hue Frances S Cho Siqi Cao Cameron R ”Dale” Bass David F Meaney Barclay Morrison III 《Journal of cerebral blood flow and metabolism》2015,35(7):1191-1198
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α− isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury. 相似文献
5.
6.
7.
8.
9.
P J Hayden C J Welsh Y Yang W H Schaefer A J Ward J L Stevens 《Chemical research in toxicology》1992,5(2):232-237
Nephrotoxic cysteine conjugates derived from a variety of halogenated alkenes are enzymatically activated via the beta-lyase pathway to yield reactive sulfur-containing metabolites which bind covalently to cellular macromolecules. Mitochondria contain beta-lyase enzymes and are primary targets for binding and toxicity. Previously, mitochondrial protein and/or DNA have been considered as molecular targets for cysteine conjugate metabolite binding. We now report that metabolites of nephrotoxic cysteine conjugates form covalent adducts with rat kidney mitochondrial phospholipids. Rat kidney mitochondria were incubated with the 35S-labeled conjugates S-(1,1,2,2-tetrafluoroethyl)-L-cysteine (TFEC), S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine (CTFC), S-(1,2-dichlorovinyl)-L-cysteine, and S-(1,2,3,4,4-pentachlorobutadienyl)-L-cysteine. Quantitation of metabolite binding to whole mitochondria and to mitochondrial protein and lipid fractions revealed that as much as 42% of the 35S-label associated with the mitochondria was found in the lipid fraction. Total lipids were also extracted from 35S-treated mitochondria and separated by thin-layer chromatography. 35S-Containing metabolites were found in the lipid fractions from mitochondria treated with each of the conjugates. Lipids from both [35S]CTFC- and [35S]-TFEC-treated mitochondria contained major 35S-labeled lipid adducts which had similar mobility by thin-layer chromatography. Fatty acid analysis, 19F and 31P NMR spectroscopy, and mass spectrometric analyses confirmed that the major TFEC and CTFC adducts are thioamides of phosphatidylethanolamine. 相似文献
10.
Rats were killed after 6 weeks of continuous ingestion of the pneumotoxic alkaloid monocrotaline (2.2 mg/kg/day), the neutrophil elastase inhibitor SC39026 (60 mg/kg/day), or both. Pulmonary reactions were evaluated by light and electron microscopy. Lung endothelial function was monitored by angiotensin converting enzyme (ACE) activity, plasminogen activator (PLA) activity, and prostacyclin (PGI2) and thromboxane (TXA2) production. Lung hydroxyproline content was measured as an index of interstitial fibrosis. Cardiac right ventricular hypertrophy was determined by the right ventricle to the left ventricle plus septum weight ratio (RV/LV + S). Rats receiving SC39026 alone did not differ significantly from untreated control animals with respect to any of the quantitative endpoints, although rarefaction of Type I pneumocytes was observed in the electron micrographs of these animals. Monocrotaline-treated rats, in contrast, developed a significant increase in RV/LV + S, and exhibited pulmonary edema, inflammation, fibrosis, and muscularization and occlusive mural thickening of the pulmonary small arteries and arterioles. These monocrotaline-induced structural changes were accompanied by decreased lung ACE and PLA activities, and increased PGI2 and TXA2 production, and by an increase in lung hydroxyproline content. Cotreatment with SC39026 ameliorated the monocrotaline-induced pulmonary vascular wall thickening and the cardiac right ventricular hypertrophy. These data suggest that inappropriate neutrophil elastase activity contributes to monocrotaline pulmonary vasculopathy and hypertension. On the other hand, cotreatment with SC39026 had no significant effect on the severity of the monocrotaline-induced lung inflammatory reaction, the pulmonary endothelial dysfunction, or the increase in lung hydroxyproline content. 相似文献