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   41341篇
  免费   2965篇
  国内免费   163篇
耳鼻咽喉   499篇
儿科学   1346篇
妇产科学   553篇
基础医学   4992篇
口腔科学   525篇
临床医学   4264篇
内科学   9194篇
皮肤病学   701篇
神经病学   3934篇
特种医学   1669篇
外科学   7219篇
综合类   358篇
一般理论   81篇
预防医学   3119篇
眼科学   1152篇
药学   2147篇
中国医学   39篇
肿瘤学   2677篇
  2024年   22篇
  2023年   349篇
  2022年   669篇
  2021年   1564篇
  2020年   772篇
  2019年   1287篇
  2018年   1560篇
  2017年   1065篇
  2016年   1169篇
  2015年   1256篇
  2014年   1753篇
  2013年   2068篇
  2012年   3479篇
  2011年   3471篇
  2010年   1890篇
  2009年   1685篇
  2008年   2805篇
  2007年   2741篇
  2006年   2646篇
  2005年   2500篇
  2004年   2442篇
  2003年   2044篇
  2002年   1885篇
  2001年   239篇
  2000年   170篇
  1999年   240篇
  1998年   357篇
  1997年   313篇
  1996年   232篇
  1995年   220篇
  1994年   166篇
  1993年   162篇
  1992年   110篇
  1991年   108篇
  1990年   80篇
  1989年   70篇
  1988年   50篇
  1987年   62篇
  1986年   58篇
  1985年   59篇
  1984年   74篇
  1983年   83篇
  1982年   102篇
  1981年   76篇
  1980年   52篇
  1979年   26篇
  1978年   32篇
  1977年   33篇
  1976年   20篇
  1973年   20篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
71.
72.
Knee anterior cruciate ligament reconstructive surgery has significantly evolved and now includes the option of using an allograft. This has resulted in numerous studies evaluating the advantages and disadvantages of allografts. The purpose of this literature review is to evaluate this research and present important findings to allow the selection of the most appropriate graft source when considering allograft versus autograft reconstruction.  相似文献   
73.

Background  

Many factors impacting cecal intubation rates have been examined in detail; however, little information exists regarding the effect of the timing of the procedure. We sought to examine any difference in cecal intubation rates between morning and afternoon colonoscopies and identify factors contributing to a discrepancy.  相似文献   
74.
OBJECTIVE: To develop biomechanical variable models for driver skull base injury mechanisms in motor vehicle collisions. STUDY DESIGN: Retrospective database review. METHODS: Biomechanical collision variables and safety restraint data were analyzed for Crash Injury Research and Engineering Network skull base trauma subjects enrolled during the recruitment period between 1996 and 2005. RESULTS: For drivers satisfying inclusion criteria (n = 26), injury resulted from contact with rigid vehicle structural elements in 82%, and occurred in 50% despite both seatbelt and air bags. Eight percent used neither seatbelts nor air bags. Seventy-two percent involved vector velocity changes greater than 30 mph. The relative morbidity of skull base injuries was also detailed. CONCLUSION: The majority of driver skull base injuries resulted from contact with rigid vehicle structural elements in high velocity crashes. Seatbelt and air bag use could not be definitively correlated with skull base injury. CLINICAL SIGNIFICANCE: Injury mechanism models can be developed that facilitate further investigations to determine impact and scope on a national scale.  相似文献   
75.
76.
慢性胰腺炎的临床表现包括疼痛、脂肪泻和糖尿病。在西方国家,慢性胰腺炎最常见的病因是酗酒。70%以上的病人在就诊时有疼痛的临床表现,而且,这些患者中又有75%以上会在几年之后出现疼痛减轻或完全消失。对于所有的慢性胰腺炎的病人来说,均应排除非胰源性疼痛和胆道梗阻、胰腺假性囊肿等胰腺局部并发症。应建议所有慢性胰腺炎病人戒烟、戒酒。阿片类镇痛剂仅应用于治疗疼痛严重的病人。尽管有报道认为胰酶替代治疗有助于止痛,但是,对于已经确诊的慢性胰腺炎病人来说,该疗法无效。激素类药物进行腹腔神经丛阻滞术可能有助于病人度过剧烈疼痛期。顽固性疼痛是进行胰液引流或胰腺切除的适应证。建议应用适量胰酶替代联合(或不联合)制酸剂治疗营养不良。慢性胰腺炎导致的糖尿病与原发性糖尿病的治疗原则相似。  相似文献   
77.
78.
79.
80.
Summary We enrolled children with acute lymphoblastic leukemia (ALL) in a Pediatric Oncology Group (POG) pilot study to monitor erythrocyte (RBC) methotrexate (MTX) and folate (F) levels before and during treatment. The mean value for RBCF at diagnosis was 0.86±0.46 nmol/ml RBC in the 214 patients who achieved remission and 1.21±0.74 nmol/ml RBC in the 10 patients who did not (P=0.020). Folate levels tended to increase during remission induction, but they dropped following an intensive consolidation with methotrexate to levels that were sustained throughout chemotherapy treatment. Methotrexate levels reached mean values of approximately 0.15 nmol/ml RBC at the end of an intensive methotrexate consolidation, then fell to levels that were sustained throughout maintenance therapy. There was a weak correlation between improved event-free survival and higher RBCMTX levels after consolidation, but no correlation was found between improved survival and the level of RBCMTX or RBCF during maintenance therapy. A larger study with more complete data is needed to determine whether RBCMTX or RBCF might be useful in predicting event-free survival in patients with ALL.This work was supported in part by grants from the National Cancer Institute and the National Institute of Health (CA-30969, CA-28476, CA29139, CA-159-89, and CA-33587)  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