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   180398篇
  免费   1100篇
  国内免费   31篇
耳鼻咽喉   1212篇
儿科学   6695篇
妇产科学   3102篇
基础医学   17154篇
口腔科学   1622篇
临床医学   12558篇
内科学   32032篇
皮肤病学   696篇
神经病学   16844篇
特种医学   9058篇
外科学   29789篇
综合类   2332篇
一般理论   1篇
预防医学   18166篇
眼科学   2845篇
药学   9904篇
中国医学   635篇
肿瘤学   16884篇
  2022年   51篇
  2021年   102篇
  2020年   45篇
  2019年   99篇
  2018年   22014篇
  2017年   17420篇
  2016年   19599篇
  2015年   1003篇
  2014年   935篇
  2013年   939篇
  2012年   7231篇
  2011年   21281篇
  2010年   18976篇
  2009年   11653篇
  2008年   19747篇
  2007年   21941篇
  2006年   842篇
  2005年   2517篇
  2004年   3672篇
  2003年   4669篇
  2002年   2828篇
  2001年   314篇
  2000年   462篇
  1999年   233篇
  1998年   289篇
  1997年   284篇
  1996年   152篇
  1995年   200篇
  1994年   171篇
  1993年   131篇
  1992年   101篇
  1991年   143篇
  1990年   161篇
  1989年   128篇
  1988年   100篇
  1987年   83篇
  1986年   56篇
  1985年   62篇
  1984年   54篇
  1983年   55篇
  1982年   60篇
  1981年   38篇
  1980年   69篇
  1976年   26篇
  1974年   31篇
  1970年   26篇
  1938年   60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
71.
72.
Recent reports of sexually transmitted infection-rate increases among men indicate the need for renewed study of male sexual risk behavior to aid development of updated and novel risk reduction interventions. Men who have childhood sexual abuse (CSA) histories consistently report frequent sexual risk behavior. The objective of this sturdy is to explore whether posttraumatic stress disorder (PTSD) and depression are moderators and/or mediators of the association between CSA and sexual risk in adult men. A cross-sectional survey study employing random digit dial recruitment was administered to men aged 18–49 years from Philadelphia County. Two bundred ninety eight men were recruited and screened for CSA history, administered items from the Posttraumatic Stress Diagnostic Scale (PDS) and Center for Epidemiologic Studies—Depression (CES-D), and asked to estimate their number of lifetime sexual partners (LSPs). Effects of sociodemographic characteristics, CSA, PTSD, and depression on the number of LSPs were modeled using Poisson regression. Results show that 197 (66%) men participated; 43 (22%) had CSA histories. CSA was significantly associated with PTSD/depression (P=.03). Four sociodemographic variables (age, race, sexual identity, and education), CSA (incidence rate ratio, IRR=1.47, P<.001), PTSD (IRR=1.19, P=.04), depression (IRR=1.29, P=.001), all 2-way interactions, and the 3-way CSA/PTSD/depression interaction (IRR=11.00, P<.001) were associated with the number of LSPs (R2=0.27). In conclusion, sexual partnership patterns unique to men with CSA histories and comorbid PTSD/depression appear to lead to substantially higher numbers of LSPs. Estimates of this relationship may have been biased toward the null by underreporting that can occur with phone surveys. Cross-sectional studies do not support causal inferences; however, the identification of a moderating and mediating influence of PTSD/depression on the relationship between CSA and sexual risk behavior is important and suggests the need for future studies with larger samples that examine trajectories for CSA, psychiatric illness, and sexual partnerships.  相似文献   
73.
74.
75.
Stenosis of the hypopharyngo-oesophageal junction can be a rare complication of laryngectomy and/or partial pharyngectomy and makes the insertion of voice prosthesis extremely difficult. This study describes the authors’ experiences gained by endoscopic balloon-catheter dilatation of hypopharyngo-oesophageal stenoses prior to implantation of voice prostheses in four cases. In two patients a single balloon-catheter dilatation resulted in wide enough pharyngo-oesophageal lumen on the long run. The average prosthesis wearing-times were 6.8 months in case 1 and 4.6 months in case 2, corresponding to the published literature data. In case 3, repeated dilatation of the pharyngo-oesophageal transition had proved to be unsuccessful despite taking every effort with the endoscopic balloon-catheter method. Having excised the stenotic segment, reconstruction with pectoralis major myocutaneous flap (PMMF) was indicated. Eighteen months later, a repeated restenosis was observed and a free jejunal flap needed to be performed as a final solution. In case 4, the insertion was carried out into a previously dilated jejunal free flap, which became gradually ischemic and stenotic since the major head-and neck procedure was carried out that resulted in prosthesis rejection after just 1 week. The authors emphasize that correct indication of pedicled and free flaps in head and neck reconstruction is a prerequisite from the aspect of prevention of pharyngo-oesophageal strictures. Endoscopic balloon-catheter dilatation is a safe and established method for dilatating hypopharyngo-oesophageal stenoses of different origin. The procedure provides maximum patient benefit with minimal trauma and morbidity; moreover, facilitates insertion of voice prostheses. However, a single balloon-catheter dilatation cannot always result in wide enough oesophageal lumen on the long run (case 3). Insertion of a voice prosthesis into a previously dilated ischemic jejunal segment is challenging and avoidable due to risks of complications.  相似文献   
76.
Epiploic appendagitis and omental infarction: pitfalls and look-alikes   总被引:3,自引:0,他引:3  
Epiploic appendagitis and omental infarction are benign self-limiting conditions that are more frequent than generally assumed. Both disorders frequently mimic symptoms of an abdominal surgical emergency, often leading to clinical misdiagnosis of appendicitis or diverticulitis. Because a misdiagnosis can result in an unnecessary laparotomy, a correct diagnosis is of great importance. Ultrasound and computed tomography can be used to make a reliable diagnosis. This pictorial essay illustrates the various ultrasonographic and computed tomographic appearances of epiploic appendagitis and omental infarction and focuses on their radiologic differential diagnoses and pitfalls. Received: 22 February 2001/Accepted: 18 April 2001  相似文献   
77.
78.
Ohne Zusammenfassung  相似文献   
79.
80.
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