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   52162篇
  免费   3694篇
  国内免费   181篇
耳鼻咽喉   601篇
儿科学   1068篇
妇产科学   794篇
基础医学   6663篇
口腔科学   701篇
临床医学   4825篇
内科学   12522篇
皮肤病学   531篇
神经病学   5121篇
特种医学   2098篇
外科学   8437篇
综合类   578篇
一般理论   65篇
预防医学   3561篇
眼科学   922篇
药学   3169篇
中国医学   50篇
肿瘤学   4331篇
  2023年   255篇
  2022年   227篇
  2021年   1300篇
  2020年   900篇
  2019年   1297篇
  2018年   1646篇
  2017年   1125篇
  2016年   1205篇
  2015年   1441篇
  2014年   2166篇
  2013年   2515篇
  2012年   4337篇
  2011年   4301篇
  2010年   2407篇
  2009年   2157篇
  2008年   3761篇
  2007年   3877篇
  2006年   3754篇
  2005年   3695篇
  2004年   3286篇
  2003年   3025篇
  2002年   2729篇
  2001年   301篇
  2000年   203篇
  1999年   298篇
  1998年   415篇
  1997年   363篇
  1996年   275篇
  1995年   315篇
  1994年   249篇
  1993年   232篇
  1992年   138篇
  1991年   126篇
  1990年   108篇
  1989年   94篇
  1988年   87篇
  1987年   71篇
  1986年   78篇
  1985年   100篇
  1984年   122篇
  1983年   102篇
  1982年   136篇
  1981年   108篇
  1980年   93篇
  1979年   41篇
  1978年   57篇
  1977年   55篇
  1976年   48篇
  1975年   38篇
  1974年   38篇
排序方式: 共有10000条查询结果,搜索用时 218 毫秒
1.
Postbariatric loss of muscle tissue could negatively affect long-term health due to its role in various bodily processes, such as metabolism and functional capacity. This meta-analysis aimed to unravel time-dependent changes in the magnitude and progress of lean body mass (LBM), fat-free mass (FFM), and skeletal muscle mass (SMM) loss following bariatric surgery. A systematic literature search was conducted in Pubmed, Embase, and Web of Science. Fifty-nine studies assessed LBM (n = 37), FFM (n = 20), or SMM (n = 3) preoperatively and ≥1 time points postsurgery. Random-effects meta-analyses were performed to determine pooled loss per outcome parameter and follow-up time point. At 12-month postsurgery, pooled LBM loss was ?8.13 kg [95%CI ?9.01; ?7.26]. FFM loss and SMM loss were ?8.23 kg [95%CI ?10.74; ?5.73] and ?3.18 kg [95%CI ?5.64; ?0.71], respectively. About 55% of 12-month LBM loss occurred within 3-month postsurgery, followed by a more gradual decrease up to 12 months. Similar patterns were seen for FFM and SMM. In conclusion, >8 kg of LBM and FFM loss was observed within 1-year postsurgery. LBM, FFM, and SMM were predominantly lost within 3-month postsurgery, highlighting that interventions to mitigate such losses should be implemented perioperatively.  相似文献   
2.
3.
BackgroundAdjuvant chemotherapy, postoperative radiation (PORT), and prophylactic cranial irradiation (PCI) have been individually examined in limited-stage small cell lung cancer (SCLC). There is a paucity of data on the effectiveness of each adjuvant treatment modality when used in combination after surgical resection of SCLC.MethodsData were collected from 5 cancer centers on all patients with limited-stage SCLC who underwent surgical resection between 1986 and 2019. Univariate and multivariable models were conducted to identify predictors of long-term outcomes, focusing on freedom from recurrence and survival benefit of adjuvant chemotherapy, PORT, and PCI.ResultsA total of 164 patients were analyzed. Multivariable Cox regression analysis did not identify any adjuvant therapies to significantly influence recurrence in this cohort. Specifically, PORT was not associated with a significant influence on locoregional recurrence and PCI was not significantly associated with intracranial outcomes. Adjuvant chemotherapy improved survival in all stage I through III disease (hazard ratio, 0.49; 95% confidence interval, 0.29-0.81; P = .005) and even in pathologically node negative patients (hazard ratio, 0.49; 95% confidence interval, 0.27-0.91; P = .024). Although PCI was found to improve survival in univariate analysis, it was not significant in a multivariable model. PORT was not found to affect survival on either univariate or multivariable analysis.ConclusionsThis is among the largest multi-institutional studies on surgically resected limited-stage SCLC. Our results highlight survival benefit of adjuvant chemotherapy, but did not identify a statistically significant influence from mediastinal PORT or PCI in our cohort. Larger prospective studies are needed to determine the benefit of PORT or PCI in a surgically resected limited-stage SCLC population.  相似文献   
4.
5.
In the present review, we updated current information on the chemistry, contents, and anticancer properties of matrine (MT), oxymatrine (OMT), and compound Kushen injection (CKI). The anticancer properties were focused on lung, breast, and liver cancer cells because they are most susceptible. Sources of information were from Google, Google Scholar, PubMed, PubMed Central, Science Direct, PubChem, J-Stage, Directory of Open Access Journals (DOAJ), and China National Knowledge Infrastructure (CNKI). Reference was also made on botanical websites, such as Flora of China and World Flora Online. MT and OMT are dominant quinolizidine alkaloids from the roots of Sophora flavescens (Kushen) of the family Fabaceae. Against lung, breast, and liver cancer cells, MT and OMT inhibit cell proliferation; induce cell cycle arrest, apoptosis, and autophagy; restrict angiogenesis; and inhibit cell metastasis, invasion, and migration. The processes involve various molecular targets and signaling pathways. CKI is a traditional Chinese medicine (TCM) composed of root extracts of S. flavescens and Smilax glabra (Baituling) of the family Smilacaceae. With MT and OMT as major components, CKI has been approved for the treatment of cancer in China more than 20 years ago. In recent years, systematic reviews and meta-analysis have been undertaken to evaluate the anticancer effects of CKI. When CKI is used alone and in combination with chemotherapy of western medicine, there is much to be learned concerning their interactions besides their individual and integrated efficacy. Some perspectives of MT, OMT, and CKI are discussed, and their suggestions for future research are provided.  相似文献   
6.
7.
8.
9.
10.
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