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   189391篇
  免费   2225篇
  国内免费   65篇
耳鼻咽喉   1324篇
儿科学   6948篇
妇产科学   3223篇
基础医学   18329篇
口腔科学   1741篇
临床医学   13920篇
内科学   33788篇
皮肤病学   1028篇
神经病学   17259篇
特种医学   9519篇
外科学   31143篇
综合类   2418篇
现状与发展   1篇
一般理论   4篇
预防医学   19240篇
眼科学   3234篇
药学   10451篇
中国医学   708篇
肿瘤学   17403篇
  2023年   182篇
  2022年   450篇
  2021年   848篇
  2020年   454篇
  2019年   562篇
  2018年   22471篇
  2017年   17714篇
  2016年   19931篇
  2015年   1390篇
  2014年   1417篇
  2013年   1421篇
  2012年   7977篇
  2011年   21948篇
  2010年   19357篇
  2009年   11965篇
  2008年   20265篇
  2007年   22437篇
  2006年   1200篇
  2005年   2784篇
  2004年   3908篇
  2003年   4799篇
  2002年   2911篇
  2001年   747篇
  2000年   843篇
  1999年   518篇
  1998年   310篇
  1997年   299篇
  1996年   170篇
  1995年   170篇
  1994年   160篇
  1993年   113篇
  1992年   183篇
  1991年   184篇
  1990年   239篇
  1989年   180篇
  1988年   142篇
  1987年   116篇
  1986年   86篇
  1985年   82篇
  1984年   66篇
  1983年   53篇
  1982年   44篇
  1980年   53篇
  1974年   24篇
  1970年   23篇
  1938年   60篇
  1937年   25篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.

Background  

Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy.  相似文献   
992.
993.
We report the case of a 62-year-old man without prodromal symptoms who developed a hemolytic-uremic syndrome (HUS) one week after the diagnosis of an acute bacteremic urinary infection (UTI). In this patient, the E. coli isolated in blood cultures was a non-O157:H7 Shigatoxin-producing strain that could subsequently be identified as O138:H-. This is a strain that is normally found in pigs and that has never been isolated in humans previously. UTI-related HUS is a rare event, as until now, only 14 pediatric and 3 adult cases have been reported. Indeed, this new case, besides its interesting microbiological aspects, should heighten our awareness of UTI-related HUS as a rare but real condition, not only in young children but also in adult patients. This should emphasize the necessity to search actively for other sources of Shigatoxin-producing E. coli in patients presenting with HUS without gastrointestinal symptoms.  相似文献   
994.
995.
996.
997.
A heart under chronic stress undergoes cardiac remodelling, a process that comprises structural and functional changes including cardiomyocyte hypertrophy, interstitial fibrosis, contractile dysfunction, cell death and ventricular dilatation. Reactive oxygen species (ROS)-dependent modulation of intracellular signalling is implicated in the development of cardiac remodelling. Among the different ROS sources that are present in the heart, NADPH oxidases (NOXs) are particularly important in redox signalling. NOX isoforms are expressed in multiple cell types including cardiomyocytes, fibroblasts, endothelial cells and inflammatory cells—with the two main isoforms expressed in the heart being NOX2 and NOX4. Recent studies indicate that NOX-dependent signalling is involved in the development of cardiomyocyte hypertrophy, interstitial fibrosis and post-MI remodelling. NOXs may also be involved in the genesis of contractile dysfunction and myocyte apoptosis. Here, we review the main effects of NOXs in the pathogenesis of cardiac remodelling and the redox-sensitive signalling pathways that underlie these effects. The elucidation of mechanisms involved in NOX-dependent regulation of cardiac remodelling may lead to new therapeutic targets for heart failure.  相似文献   
998.
Sinusitis is a frequent complication of respiratory tract infections. Probiotics are perceived to be useful in infections, allergies, and inflammations. Our prospective trial stratified 204 children with recurrent rhinosinusitis by age (2–11 years, 54m:64f; 12–18 years, 39m:47f) and assigned them to standard treatment (antibiotics, anticongestants) or additional 60 days Symbioflor-1 (SF1; Enterococcus faecalis 1.5–4.5x107 CFU). The number of sinusitis episodes was lower in SF1-treated patients (2.52±0.91) than among controls (3.27±1.36; p=0.01). Mean duration of the first sinusitis episode was 11.9±8.6 days with SF1, whereas it was 16.1±12.9 days in the younger controls (p=0.023) and 9.86±5.05 days in the elder controls (n.s.). Duration of subsequent sinusitis episodes was also shorter in SF1 patients (15.2±13.6 days) compared with controls (22.7±14.8 days; p=0.030). No adverse events were observed. Probiotic Enterococcus faecalis adjuvant to conventional therapy can reduce the number and duration of rhinosinusitis episodes in children and adolescents.  相似文献   
999.
Breast-conserving therapy, which includes wide local excision of the tumor followed by irradiation, has become a standard treatment option for women with early-stage invasive breast cancer. The potential advantages of conservative breast surgery include the minor outpatient nature of the procedures, lower incidence of post-operative pain and complications, preservation of the breast and nipple areolar complex, and shorter delay to adjuvant therapy. However, not all patients are optimal candidates for breast-conserving procedures. Oncoplastic techniques combine the removal of breast cancer tumors in combination with either local volume replacement techniques to correct small defects, or by immediate reconstruction of larger defects using techniques of plastic surgery with or without contralateral breast procedures for symmetry. Therefore, oncoplastic techniques offer the potential to perform a wider excision of the tumor with an improved cosmetic result, thus potentially increasing the eligible pool for breast conservation.  相似文献   
1000.
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