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   301065篇
  免费   12113篇
  国内免费   6630篇
耳鼻咽喉   2333篇
儿科学   8512篇
妇产科学   5900篇
基础医学   29553篇
口腔科学   4199篇
临床医学   28129篇
内科学   50274篇
皮肤病学   2233篇
神经病学   22597篇
特种医学   12986篇
外国民族医学   40篇
外科学   41713篇
综合类   21511篇
现状与发展   20篇
一般理论   18篇
预防医学   27284篇
眼科学   6138篇
药学   22716篇
  115篇
中国医学   7167篇
肿瘤学   26370篇
  2024年   348篇
  2023年   1717篇
  2022年   4018篇
  2021年   5458篇
  2020年   4060篇
  2019年   3714篇
  2018年   25554篇
  2017年   20817篇
  2016年   22555篇
  2015年   6096篇
  2014年   7493篇
  2013年   7652篇
  2012年   16898篇
  2011年   31506篇
  2010年   25977篇
  2009年   17477篇
  2008年   27005篇
  2007年   29119篇
  2006年   7766篇
  2005年   8762篇
  2004年   8106篇
  2003年   8637篇
  2002年   6058篇
  2001年   3341篇
  2000年   3240篇
  1999年   2794篇
  1998年   1500篇
  1997年   1416篇
  1996年   1069篇
  1995年   1043篇
  1994年   976篇
  1993年   558篇
  1992年   922篇
  1991年   882篇
  1990年   788篇
  1989年   642篇
  1988年   575篇
  1987年   487篇
  1986年   378篇
  1985年   312篇
  1984年   202篇
  1983年   187篇
  1982年   118篇
  1981年   93篇
  1980年   106篇
  1979年   142篇
  1978年   119篇
  1977年   86篇
  1974年   113篇
  1972年   87篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
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   
103.
104.
105.
106.
107.
The definition of the persistent vegetative state (PVS) is relatively straightforward, but its diagnosis can be challenging. We reviewed a series of EEG performed in patients with PVS to assess the diagnostic value of EEG. We reviewed records of all hospital patients with a diagnosis of persistent vegetative PVS. EEG findings included normal, continuous generalized slowing, intermittent generalized slowing, background slowing, background suppression, alpha, generalized periodic pattern, PLEDS, and triphasic waves. EEG findings had no association with etiology and varied from one pattern to another in the same patients' EEGs obtained at different times (see table). We conclude that EEG findings in PVS are heterogeneous and too variable to be of diagnostic value.  相似文献   
108.
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   
109.
处女膜修补手术及麻醉方法的改进   总被引:9,自引:7,他引:2  
目的;增大处女膜粘膜瓣的接触面,减少因麻醉造成的处女膜粘膜水肿,提高修复手术的成功率。方法:手术全部采用1%的卡因行粘膜表面麻醉。53例采用瓦合粘膜瓣法,3例用瓦合粘膜瓣联合阴道粘膜瓣修复法。结果:56例术后一月随访,53例处女膜孔径为一指,成功率94.64%。结论:采用1%的卡因粘膜表面麻醉,瓦合粘膜瓣法及瓦合粘膜联合阴道粘膜瓣修复法对处女膜修复是行之有效的。  相似文献   
110.
We report a rare chronic encapsulated intracerebral haematoma (CEICH). A 52-year-old man had two seizures. Unenhanced computed tomography scanning of the head revealed a hypodense tumour with clusters of calcification in the left temporal lobe. Magnetic resonance imaging of the brain showed a left temporal tumour with a hypointense centre and hyperintense periphery on T(1)-weighted imaging and heterogeneous hypointensity on T(2)-weighted imaging. The tumour was heterogeneously enhanced after gadolinium injection. Craniotomy was carried out and a CEICH in the left temporal lobe was completely excised. No vascular anomaly was found. The tumour was histologically confirmed to be a CEICH. The patient recovered well after the operation. In this report, we describe this rare case and discuss the characteristics of CEICH.  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