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   2126篇
  免费   114篇
  国内免费   11篇
耳鼻咽喉   27篇
儿科学   116篇
妇产科学   24篇
基础医学   224篇
口腔科学   28篇
临床医学   167篇
内科学   456篇
皮肤病学   39篇
神经病学   89篇
特种医学   79篇
外科学   286篇
综合类   34篇
一般理论   1篇
预防医学   142篇
眼科学   146篇
药学   182篇
中国医学   7篇
肿瘤学   204篇
  2023年   18篇
  2022年   47篇
  2021年   75篇
  2020年   36篇
  2019年   51篇
  2018年   67篇
  2017年   35篇
  2016年   50篇
  2015年   73篇
  2014年   74篇
  2013年   78篇
  2012年   154篇
  2011年   134篇
  2010年   84篇
  2009年   87篇
  2008年   120篇
  2007年   142篇
  2006年   91篇
  2005年   78篇
  2004年   84篇
  2003年   82篇
  2002年   69篇
  2001年   41篇
  2000年   50篇
  1999年   42篇
  1998年   16篇
  1997年   20篇
  1996年   24篇
  1995年   11篇
  1994年   11篇
  1993年   13篇
  1992年   37篇
  1991年   22篇
  1990年   19篇
  1989年   14篇
  1988年   16篇
  1987年   13篇
  1986年   12篇
  1985年   16篇
  1984年   14篇
  1983年   12篇
  1982年   9篇
  1981年   7篇
  1980年   11篇
  1979年   7篇
  1975年   8篇
  1974年   7篇
  1972年   12篇
  1971年   6篇
  1966年   5篇
排序方式: 共有2251条查询结果,搜索用时 0 毫秒
121.
122.
123.
124.
PURPOSE: To study the clinical spectrum and treatment outcome of retinoblastoma in Indian children. PATIENTS AND METHODS: This retrospective study analyzed 488 eyes of 355 retinoblastoma patients treated at a tertiary care ophthalmic hospital in southern India during a 14-year period. RESULTS: Retinoblastoma involved one eye in 177 (50%) and both eyes in 178 (50%) patients. Mean age at presentation was 23.98 +/- 23.37.  相似文献   
125.
Medulloepitheliomas are usually amelanotic. Pigmented medulloepitheliomas are unusual and only two cases have been reported. We report an additional case of pigmented malignant medulloepithelioma of the ciliary body with histopathologic correlation.  相似文献   
126.
OBJECTIVE: To determine whether the presence of laryngopharyngeal reflux symptoms is associated with the presence of esophageal adenocarcinoma (EAC). BACKGROUND: Most patients diagnosed with EAC have incurable disease at the time of detection. The majority of these patients are unaware of the presence of Barrett's esophagus prior to cancer diagnosis and many do not report typical symptoms of gastroesophageal reflux disease (GERD). This suggests that the current GERD symptom-based screening paradigm may be inadequate. Data support a causal relation between complicated GERD and laryngopharyngeal reflux symptoms. We theorize that laryngopharyngeal reflux symptoms are not recognized expeditiously, resulting in chronic esophageal injury and an unrecognized progression of Barrett's esophagus to EAC. METHODS: This is a case-comparison (control) study. Cases were patients diagnosed with EAC (n = 63) between 1997 and 2002. Three comparison groups were selected: 1) Barrett's esophagus patients without dysplasia (n = 50), 2) GERD patients without Barrett's esophagus (n = 50), and 3) patients with no history of GERD symptoms or antisecretory medication use (n = 56). The risk factors evaluated included demographics, medical history, lifestyle variables, and laryngopharyngeal reflux symptoms. Typical GERD symptoms and antisecretory medication use were recorded. Multivariate analysis of demographics, comorbid risk factors, and symptoms was performed with logistic regression to provide odds ratios for the probability of EAC diagnosis. RESULTS: The prevalence of patients with laryngopharyngeal reflux symptoms was significantly greater in the cases than comparison groups (P = 0.0005). The prevalence of laryngopharyngeal reflux symptoms increased as disease severity progressed from the non-GERD comparison group (19.6%) to GERD (26%), Barrett's esophagus (40%), and EAC patients (54%). Symptoms of GERD were less prevalent in cases (43%) when compared with Barrett's esophagus (66%) and GERD (86%) control groups (P < 0.001). Twenty-seven percent (17 of 63) of EAC patients never had GERD or laryngopharyngeal reflux symptoms. Fifty-seven percent of EAC patients presented without ever having typical GERD symptoms. Chronic cough, diabetes, and age emerged as independent risk factors for the development of EAC. CONCLUSIONS: Symptoms of laryngopharyngeal reflux are more prevalent in patients with EAC than typical GERD symptoms and may represent the only sign of disease. Chronic cough is an independent risk factor associated with the presence of EAC. Addition of laryngopharyngeal reflux symptoms to the current Barrett's screening guidelines is warranted.  相似文献   
127.
PURPOSE: We describe our experience with transvaginal total pelvic reconstruction using a mesh with 4-point fixation for patients with genitourinary prolapse with or without stress urinary incontinence. MATERIALS AND METHODS: A total of 29 consecutive patients who underwent sacrospinous fixation using mesh material since March 1999 for genitourinary prolapse were analyzed retrospectively. In all patients defect specific repair was done, including hysterectomy (in 13). For isolated vault prolapse a rectangular mesh was interposed between the peritoneum and vaginal vault, with each corner anchored to the sacrospinous ligament using a suture-capturing device. For vault prolapse associated with anterior vaginal wall prolapse an "H" shaped, 1-piece sling was used to support both entities. Additionally, posterior and perineal repairs were done through separate incisions if needed. RESULTS: Of the 29 patients 19 (65.5%), 7 (26.92%) and 11 (39.29%) had associated symptoms of stress urinary incontinence, urgency and frequency, respectively, and 79.31% had associated anterior and 44.8% had associated posterior prolapse. Average operative time was 175.6 minutes, blood loss was 340 cc and hospital stay was 2.46 days. Early adverse events following the procedure were perineal pain, vaginal discharge and irritative voiding symptoms. At 6 month followup (mean 25.14 months) mild constipation and dyspareunia were encountered in a small subset of patients. Two patients (6.89%) have genital prolapse recurrence and none has reported erosion or nonhealing to date. CONCLUSIONS: Transvaginal technique of 4-point vaginal vault fixation using mesh is a safe and effective procedure at 2 years.  相似文献   
128.
129.
There is an emerging evidence that plumbagin (5-hydroxy-2-methyl-1, 4-naphthoquinone) may have potential as a chemotherapeutic agent. However, the growth inhibitory mechanisms of plumbagin have remained unexplored. The aim of the study was to determine whether plumbagin-induced cell death in human cervical cancer cell line, ME-180, exhibited biochemical characteristics of apoptosis and to check whether N-acetyl-l-cysteine (NAC), which is a free radical scavenger, can reverse the cytotoxic effects of plumbagin. It can be concluded from the results that plumbagin inhibits the growth of ME-180 cells in a concentration and time-dependent manner. The cytotoxic effect of plumbagin induced cell death is through the generation of reactive oxygen species (ROS) and subsequent induction of apoptosis as demonstrated by the present data. Treatment of cells with plumbagin caused loss of mitochondrial membrane potential (DeltaPsi(m)), and morphological changes characteristic of apoptosis, such as the translocation of phosphatidyl serine, nuclear condensation, and DNA fragmentation. Moreover, plumbagin-induced apoptosis involved release of mitochondrial cytochrome c and apoptosis inducing factor (AIF), thus activation of caspase-dependent and -independent pathways, as shown by the plumbagin-mediated activation of caspase-3 and -9. Our results also show that pretreatment of ME-180 cells with NAC blocks plumbagin-induced loss of DeltaPsi(m) and subsequent release of cytochrome c, AIF, and caspase-9 and -3 activation, thus inhibiting the apoptotic ability of plumbagin.  相似文献   
130.
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