首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   31717篇
  免费   1824篇
  国内免费   151篇
耳鼻咽喉   292篇
儿科学   423篇
妇产科学   346篇
基础医学   4253篇
口腔科学   982篇
临床医学   2072篇
内科学   7565篇
皮肤病学   848篇
神经病学   2253篇
特种医学   1269篇
外科学   5548篇
综合类   154篇
一般理论   1篇
预防医学   989篇
眼科学   644篇
药学   2438篇
中国医学   44篇
肿瘤学   3571篇
  2022年   242篇
  2021年   543篇
  2020年   326篇
  2019年   398篇
  2018年   520篇
  2017年   479篇
  2016年   509篇
  2015年   549篇
  2014年   715篇
  2013年   904篇
  2012年   1345篇
  2011年   1476篇
  2010年   867篇
  2009年   783篇
  2008年   1317篇
  2007年   1316篇
  2006年   1348篇
  2005年   1438篇
  2004年   1333篇
  2003年   1351篇
  2002年   1280篇
  2001年   1291篇
  2000年   1326篇
  1999年   1197篇
  1998年   396篇
  1997年   336篇
  1996年   302篇
  1995年   282篇
  1994年   245篇
  1993年   238篇
  1992年   820篇
  1991年   724篇
  1990年   732篇
  1989年   698篇
  1988年   711篇
  1987年   622篇
  1986年   613篇
  1985年   597篇
  1984年   392篇
  1983年   323篇
  1982年   149篇
  1980年   134篇
  1979年   319篇
  1978年   204篇
  1977年   151篇
  1975年   149篇
  1974年   213篇
  1973年   151篇
  1972年   165篇
  1971年   147篇
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
991.
Adynamic bone disease in HD patients is characterized by skeletal resistance to parathyroid hormone (PTH) or suppression of PTH release, leading to a downregulated bone turnover and bone fracture. Hence, we examined the efficacy of weekly teriparatide for HD patients with low PTH indicating adynamic bone disease without a history of parathyroidectomy. Fifteen HD patients with low PTH were recruited in this prospective observational study. Of them, 10 received teriparatide for 12 months and five nontreated patients were enrolled as control. Primary outcomes were defined as the changes in bone mineral density and bone turnover markers. Bone mineral density at the lumbar spine increased by 3.7% and 2.5% at 6 and 12 months, respectively, and bone formation markers increased, while bone resorption markers did not change in the teriparatide group. At 12 months after teriparatide administration, endogenous PTH was secreted followed by the recovery of low bone turnover. 40% of patients in the teriparatide group dropped out due to adverse events and the most common adverse event was transient hypotension. This study suggests that weekly teriparatide for HD patients with low PTH in the absence of parathyroidectomy accelerates bone formation and bone turnover, leading to increased trabecular bone mass and secretion of endogenous PTH.  相似文献   
992.
The effects of solifenacin and mirabegron on vesical and urethral function were compared in rats with or without spinal cord injury (SCI). Isovolumetric cystometry and urethral pressure recording were initially performed in intact rats. Then, the bladder neck was ligated under urethane anesthesia, after which a catheter was inserted through the bladder dome for isovolumetric cystometry and another catheter was inserted into the urethra to measure urethral pressure. Solifenacin (0.03–3 mg/kg) or mirabegron (0.03–3 mg/kg) was injected intravenously, and bladder and urethral activity were recorded. To create rats with SCI, the spinal cord was transected at the lower thoracic level under isoflurane anesthesia. After 2 weeks, a catheter was inserted through the bladder dome for single cystometry and bladder activity was recorded without anesthesia following intravenous injection of solifenacin or mirabegron. Isovolumetric cystometry revealed a larger decrease in maximum bladder contraction pressure after injection of solifenacin, whereas prolongation of the interval between bladder contractions was greater with mirabegron. In SCI rats, single cystometry showed that solifenacin and mirabegron both increased bladder volume at the first non‐voiding bladder contraction and decreased the maximum bladder contraction pressure. Mirabegron also increased the voided volume and decreased the percentage residual volume without altering bladder capacity. Solifenacin and mirabegron both inhibited bladder contractility, and mirabegron possibly also induced urethral relaxation. Mirabegron may be suitable for patients with overactive bladder and residual urine.  相似文献   
993.
994.
995.
996.

Background

Cardiac fibrosis is considered to be a crucial factor in the development of heart failure. Blockade of the mineralocorticoid receptor (MR) attenuated cardiac fibrosis and improved the prognosis of patients with chronic heart failure but the ligand for MR and the regulatory mechanism of MR pathway in the diseased heart are unclear. Here, we investigated whether glucocorticoids can promote cardiac fibrosis through MR in oxidative stress and the involvement of elongation factor eleven-nineteen lysine-rich leukemia (ELL), a co-activator of MR, in this pathway.

Methods and Results

The MR antagonist eplerenone attenuated corticosterone-induced collagen synthesis assessed by [3H]proline incorporation in rat neonatal cultured cardiac fibroblasts in the presence of H2O2, as an oxidative stress but not in the absence of H2O2. H2O2 increased the ELL expression levels and MR-bound ELL. ELL expression levels and MR-bound ELL were also increased in the left ventricle of heart failure model rats with significant fibrosis and enhanced oxidative stress. Eplerenone did not attenuate corticosterone-induced increase of [3H]proline incorporation in the presence of H2O2 after knockdown of ELL expression using small interfering RNA in cardiac fibroblasts.

Conclusion

Glucocorticoids can promote cardiac fibrosis via MR in oxidative stress, and oxidative stress modulates MR response to glucocorticoids through the interaction with ELL. Preventing cardiac fibrosis by modulating glucocorticoid-MR-ELL pathway may become a new therapeutic strategy for heart failure.  相似文献   
997.
998.
The disposition of drugs and their metabolites have been extensively described in the literature, based primarily on the analysis of plasma and urine. However, there are more limited data on their disposition in whole blood, which is often the only specimen available in forensic investigations and cases of driving under the influence of drugs. In this study, we have, for the first time, established pharmacokinetic properties of cocaine (COC) and its metabolites from concurrently collected whole blood and plasma samples, following a single 100 mg dose of cocaine hydrochloride administered via nasal insufflation to seven healthy volunteers. The median Cmax of COC and its major metabolites, benzoylecgonine (BZE) and ecgonine methyl ester (EME), were closely related in whole blood and plasma. The median Cmax for COC in plasma was 379.7 ng/mL (347.5–517.7) and 344.24 ng/mL (271.6–583.2) in whole blood. The median Cmax for BZE in plasma was 441.2 ng/mL (393.6–475. and 371.18 ng/mL (371.1–477.3) in whole blood, EME was 105.5 ng/mL (93.6–151.8) in plasma and 135.5 ng/mL (87.8–183) in whole blood. Calculated medians of the whole blood to plasma ratio of COC (0.76), BZE (0.98) and EME (1.02) of approximately 1, strongly suggesting that the erythrocyte cell wall presents no barrier to COC and its metabolites. Furthermore, whole blood and plasma concentrations of COC were strongly correlated (R2 = 0.0914 R = 0.956, p < 0.0001), as was BZE (R2 = 0.0932 R = 0.965, p < 0.0001) and EME (R2 = 0.0964R = 0.928, p < 0.0001). The minor oxidative metabolite norcocaine (NCOC) was detected in both whole blood and plasma at concentrations between 1 and 5 ng/mL within 60–180 minutes, suggesting that NCOC could be indicator of recent COC administration. Data from this study have shown for the first time that COC and its metabolites BZE and EME are evenly distributed between plasma and whole blood following controlled single‐dose intranasal COC administration.  相似文献   
999.
International Journal of Clinical Pharmacy - Background Deprescribing is a patient-centered intervention with inherent uncertainties and requires shared decision making and patient involvement....  相似文献   
1000.
Although initial rituximab‐containing chemotherapies achieve high response rates, indolent B‐cell non‐Hodgkin lymphoma (B‐NHL), such as follicular lymphoma (FL), is still incurable. Therefore, new effective agents with novel mechanisms are anticipated. In this multicentre phase II study, patients with relapsed/refractory indolent B‐NHL and mantle cell lymphoma (MCL) received vorinostat 200 mg twice daily for 14 consecutive days in a 21‐d cycle until disease progression or unacceptable toxicity occurred. The primary endpoint was overall response rate (ORR) in FL patients and safety and tolerability in all patients. Secondary endpoints included progression‐free survival (PFS). Fifty‐six eligible patients were enrolled; 50 patients (39 with FL, seven with other B‐NHL, and four with MCL) were evaluable for ORR, and 40 patients had received rituximab‐containing prior chemotherapeutic regimens. For the 39 patients with FL, the ORR was 49% [95% confidence interval (CI): 32·4, 65·2] and the median PFS was 20 months (95% CI: 11·2, 29·7). Major toxicities were manageable grade 3/4 thrombocytopenia and neutropenia. Vorinostat offers sustained antitumour activity in patients with relapsed or refractory FL with an acceptable safety profile. Further investigation of vorinostat for clinical efficacy is warranted.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号