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   100201篇
  免费   8425篇
  国内免费   4686篇
耳鼻咽喉   818篇
儿科学   2212篇
妇产科学   1786篇
基础医学   10296篇
口腔科学   1685篇
临床医学   11534篇
内科学   17715篇
皮肤病学   1306篇
神经病学   6402篇
特种医学   3443篇
外国民族医学   28篇
外科学   10456篇
综合类   13542篇
现状与发展   7篇
一般理论   8篇
预防医学   7040篇
眼科学   1832篇
药学   10846篇
  60篇
中国医学   5035篇
肿瘤学   7261篇
  2024年   245篇
  2023年   1063篇
  2022年   2848篇
  2021年   4220篇
  2020年   3164篇
  2019年   2700篇
  2018年   2947篇
  2017年   2798篇
  2016年   2674篇
  2015年   3945篇
  2014年   4998篇
  2013年   5303篇
  2012年   7605篇
  2011年   8061篇
  2010年   5548篇
  2009年   4715篇
  2008年   5950篇
  2007年   5760篇
  2006年   5321篇
  2005年   4851篇
  2004年   3828篇
  2003年   3341篇
  2002年   2829篇
  2001年   2449篇
  2000年   2249篇
  1999年   2151篇
  1998年   961篇
  1997年   876篇
  1996年   735篇
  1995年   597篇
  1994年   516篇
  1993年   397篇
  1992年   891篇
  1991年   752篇
  1990年   688篇
  1989年   695篇
  1988年   564篇
  1987年   553篇
  1986年   488篇
  1985年   389篇
  1984年   318篇
  1983年   241篇
  1982年   141篇
  1981年   126篇
  1979年   230篇
  1978年   153篇
  1977年   126篇
  1974年   135篇
  1973年   133篇
  1972年   123篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
目的分析细棒、PEEK棒固定对寰枢关节稳定性的影响。方法采用6具新鲜成人枕骨(occipital bone,Oc)~颈椎C4节段进行测试,模拟以下手术及固定状态:①完整状态;②损伤状态:枢椎齿状突II型骨折;③坚强固定:寰枢椎均采用普通椎弓根螺钉固定,直径3.5 mm钛棒连接;④PEEK棒:直径3.5 mm的PEEK棒连接;⑤细棒:直径2.0 mm钛棒连接。采用重复测量实验设计,在完整、损伤和不同的固定状态下,通过脊柱试验机对标本分别施加1.5 N·m的前屈/后伸、左/右侧弯和左/右轴向旋转的纯力偶矩。采用Optotrak三维运动测量系统连续采集标本运动,分析寰枢椎之间角度运动范围和中性区。结果采用直径3.5 mm的钛棒,2.0 mm的细棒以及3.5 mm的PEEK棒固定后,在前屈、后伸、侧弯和旋转方向上均显著减小了固定节段的运动范围(P<0.05)。直径3.5 mm和2.0 mm的棒固定后的运动范围,在各个方向上无显著性差异。PEEK棒固定的运动范围仅在侧弯方向上大于坚强固定(P=0.005),其他方向无显著性差异。3种固定方式在屈伸、侧弯和旋转方向上均显著减小了固定节段的中性区(P<0.05)。各种固定方式之间相比较,无显著性差异(P>0.05)。结论在寰枢关节采用直径2.0 mm的细棒固定,与坚强固定的稳定性相当。采用直径3.5 mm的PEEK棒固定,在前屈、后伸、旋转方向上与坚强固定的稳定性相当,在侧弯方向上弱于坚强固定。  相似文献   
3.
4.
Lessons Learned
  • The overall safety profiles of ipilimumab 3 mg/kg and 10 mg/kg administered every 3 weeks, were consistent between Chinese patients with solid tumors in the current study and patients from previous U.S. ipilimumab monotherapy studies. No new safety signals were identified.
  • The mean systemic exposures to ipilimumab (assessed by first dose area under the curve during the dosing interval and maximum serum concentration) were numerically lower in the Chinese patient population than in U.S. patients for both 3 mg/kg and 10 mg/kg doses; however, the range of serum concentrations in the Chinese and U.S. populations overlapped (3 mg/kg and 10 mg/kg), suggesting that ipilimumab pharmacokinetics was ethnically insensitive in this study.
BackgroundThis phase I, open‐label study assessed ipilimumab safety, tolerability, pharmacokinetics (PK), immunogenicity, and antitumor activity in Chinese patients with unresectable, metastatic, recurrent malignant melanoma (MM) or nasopharyngeal carcinoma (NPC).MethodsOf 39 patients enrolled, 25 received ipilimumab (11 patients received 3 mg/kg, and 14 patients received 10 mg/kg). Reasons for not receiving treatment were withdrawal of consent (3 patients), no longer meeting the criteria (10 patients), and one recorded as “other.” During the induction phase, patients received ipilimumab (3 mg/kg, i.v.), on day 1 of a 3‐week cycle, to a maximum of four doses or progressive disease (PD). During the maintenance phase at week 24, patients received ipilimumab (3 mg/kg, i.v.) on day 1 of a 12‐week cycle, to a maximum of 3 years or PD. Considering the co‐primary safety and PK endpoints, the successive dosing required nine patients with two or fewer dose‐limiting toxicities during the 42‐day observation period to proceed with a new cohort of nine patients at 10 mg/kg.ResultsIpilimumab safety and PK profiles were similar in Chinese and predominantly White populations. Ipilimumab was well tolerated. Most adverse events (AEs) were grades 1–2 and experienced by 11 patients treated with 3 mg/kg and 14 patients treated with 10 mg/kg. There were no new safety concerns. Incidence of anti‐ipilimumab antibodies was low (1 of 10 in the 3 mg/kg patients and 2 of 13 in the 10 mg/kg patients) and without safety implications. In the 3 mg/kg group, 8 of 11 patients had PD. In the 10 mg/kg group (all NPC, 0 MM patients), 11 of 14 patients had PD. Three patients had stable disease (one at 3 mg/kg and two at 10 mg/kg).ConclusionIpilimumab was well tolerated in Chinese patients, showing similar safety and PK to previous studies in predominantly White populations.  相似文献   
5.
6.
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.  相似文献   
7.
多囊卵巢综合征(polycystic ovary syndrome,PCOS)是一种内分泌代谢紊乱综合征,临床表现高度异质性。肥胖是PCOS异质性临床表现之一,超过50%的PCOS患者超重或肥胖。肥胖型PCOS主要表现为高雄激素血症、中心型肥胖和糖脂代谢紊乱,非肥胖型PCOS主要表现为黄体生成激素(luteinizing hormone,LH)水平异常升高。尽管肥胖型和非肥胖型PCOS均存在内分泌代谢异常,然而肥胖可加重PCOS糖脂代谢紊乱;肥胖型PCOS还表现脂肪代谢的异常。综述肥胖型PCOS患者的临床特征、性激素水平、糖脂代谢特征,旨在为肥胖型和非肥胖型PCOS患者新的分型诊治提供参考。  相似文献   
8.
癫痫发作后状态(PIS)是指癫痫发作停止到恢复至发病前水平的异常状态,包括认知、运动、感觉、自主神经和精神行为等异常,症状多样,严重程度不一,持续数秒至数天不等,对患者的健康和生活质量产生很大影响。然而,目前国内外相关的研究较少,临床医生对此缺乏正确认识,容易误诊误治。本文将从PIS的定义、病理生理机制、临床表现、诊断和鉴别诊断、临床意义以及干预策略等进行综述,以提高临床医生的认识,并为今后临床研究提供参考。  相似文献   
9.
10.
Introduction: Collaborative interactions between several diverse biological processes govern the onset and progression of breast cancer. These processes include alterations in cellular metabolism, anti-tumor immune responses, DNA damage repair, proliferation, anti-apoptotic signals, autophagy, epithelial-mesenchymal transition, components of the non-coding genome or onco-mIRs, cancer stem cells and cellular invasiveness. The last two decades have revealed that each of these processes are also directly regulated by a component of the cell cycle apparatus, cyclin D1.

Area covered: The current review is provided to update recent developments in the clinical application of cyclin/CDK inhibitors to breast cancer with a focus on the anti-tumor immune response.

Expert opinion: The cyclin D1 gene encodes the regulatory subunit of a proline-directed serine-threonine kinase that phosphorylates several substrates. CDKs possess phosphorylation site selectivity, with the phosphate-acceptor residue preceding a proline. Several important proteins are substrates including all three retinoblastoma proteins, NRF1, GCN5, and FOXM1. Over 280 cyclin D3/CDK6 substrates have b\een identified. Given the diversity of substrates for cyclin/CDKs, and the altered thresholds for substrate phosphorylation that occurs during the cell cycle, it is exciting that small molecular inhibitors targeting cyclin D/CDK activity have encouraging results in specific tumors.  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