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   3821741篇
  免费   264756篇
  国内免费   9883篇
耳鼻咽喉   51521篇
儿科学   125397篇
妇产科学   103999篇
基础医学   537989篇
口腔科学   107822篇
临床医学   347238篇
内科学   747084篇
皮肤病学   90511篇
神经病学   311312篇
特种医学   142895篇
外国民族医学   1007篇
外科学   564504篇
综合类   78722篇
现状与发展   8篇
一般理论   1445篇
预防医学   298957篇
眼科学   88608篇
药学   279100篇
  12篇
中国医学   8566篇
肿瘤学   209683篇
  2021年   31023篇
  2019年   32251篇
  2018年   47489篇
  2017年   35438篇
  2016年   39797篇
  2015年   44936篇
  2014年   60689篇
  2013年   91027篇
  2012年   126149篇
  2011年   133136篇
  2010年   78048篇
  2009年   72577篇
  2008年   122562篇
  2007年   130508篇
  2006年   131260篇
  2005年   126138篇
  2004年   121060篇
  2003年   115892篇
  2002年   111820篇
  2001年   178912篇
  2000年   183242篇
  1999年   154227篇
  1998年   43668篇
  1997年   38405篇
  1996年   38505篇
  1995年   37289篇
  1994年   34088篇
  1993年   31918篇
  1992年   119130篇
  1991年   114794篇
  1990年   111155篇
  1989年   107262篇
  1988年   98280篇
  1987年   96163篇
  1986年   90360篇
  1985年   86262篇
  1984年   64354篇
  1983年   54613篇
  1982年   32065篇
  1979年   57135篇
  1978年   40124篇
  1977年   34273篇
  1976年   31867篇
  1975年   33843篇
  1974年   40511篇
  1973年   38821篇
  1972年   36239篇
  1971年   33676篇
  1970年   31203篇
  1969年   29923篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
We report the case of a 38-year-old woman who presented with chronic lower abdominal pain. Her past medical history included a splenectomy due to abdominal trauma. Ultrasound examination revealed four pelvic tumors which, upon laparotomy, were found to be the result of splenosis. Approximately 100 cases of splenosis have been reported but only a minority of them have been published in the gynecological literature. Our case indicates that those involved in pelvic scanning (even of asymptomatic women) and/or treating those complaining of lower abdominal pain or presenting with pelvic tumors should be aware of splenosis as a possible diagnosis.  相似文献   
92.
Although surgical lung resection could improve prognosis in some patients with multidrug-resistant tuberculosis (MDR-TB), there are no reports on the optimal candidates for this surgery. The aim of the present study was to elucidate the prognostic factors for surgery in patients with MDR-TB. Patients who underwent lung resection for the treatment of MDR-TB between March 1993 and December 2004 were included in the present study. Treatment failure was defined as greater than or equal to two of the five cultures recorded in the final 12 months of treatment being positive, any one of the final three cultures being positive, or the patient having died during treatment. The variables that affected treatment outcomes were identified through univariate and multivariate logistic regression analysis. In total, 79 patients with MDR-TB were included in the present study. The treatment outcomes of 22 (27.8%) patients were classified as failure. A body mass index <18.5 kg x m(-2), primary resistance, resistance to ofloxacin and the presence of a cavitary lesion beyond the range of the surgical resection were associated with treatment failure. Low body mass index, primary resistance, resistance to ofloxacin and cavitary lesions beyond the range of resection are possible poor prognostic factors for surgical lung resection in multidrug-resistant tuberculosis patients.  相似文献   
93.
The increased number of lymphocytes in airways during an asthmatic response is believed to be the result of increased recruitment of these cells. However, it is possible that a decreased apoptotic rate could also contribute to the increased number. The aim of the present study was to investigate whether allergen airway provocation influences the apoptotic phenotype of lung and peripheral blood lymphocytes (PBL) in subjects with atopic asthma. Bronchoalveolar lavage (BAL) lymphocytes and PBL from 12 asthmatic subjects previously challenged with allergen (n = 7) or saline (n = 5) were exposed to the apoptotic stimulus tributyltin (TBT) in vitro and assayed for apoptosis. Airway allergen provocation resulted in decreased sensitivity of BAL lymphocytes to TBT-induced apoptosis, with 42.2% (range 33.9-62.5%) apoptotic cells before challenge versus 23.5% (range 15.3-42.4%) after challenge, while PBL were unaffected. The increased apoptosis resistance correlated with higher numbers of Bcl-2-expressing lymphocytes. Interestingly, baseline caspase-3-like activity was significantly elevated in viable BAL lymphocytes compared with viable PBL, and was unaltered by allergen exposure. In conclusion, allergen inhalation renders bronchoalveolar lavage lymphocytes more resistant to apoptosis while peripheral blood lymphocytes were not influenced at all, indicating that the apoptotic phenotype of airway lymphocytes may play a role in asthmatic inflammation.  相似文献   
94.
95.
96.
Neu-Laxova syndrome (NLS) is a rare autosomal recessive syndrome, characterized by severe intrauterine growth retardation (IUGR), microcephaly, abnormal brain development, oedema and ichthyosis. It was first reported in 1971 by Neu et al. (Pediatrics 47: 610-612) and since then no more than 60 cases have been reported. A newborn girl delivered from a 29-year-old healthy mother was admitted to hospital with a thick membrane covering her body and dismorphic appearance. The diagnosis of NLS was made according to characteristic features. The syndrome is known to have a poor prognosis and the baby lived for 9 weeks. This case is one of the longest living cases of NLS and the fourth case reported from Turkey.  相似文献   
97.
The clinical outcome and appropriate management for patients showing 'borderline changes' on allograft biopsy after renal transplantation is still controversial. In an attempt to identify predictive factors of clinical outcome of patients with such lesions, we reviewed the clinical course of 91 patients with borderline changes. Multivariate analysis revealed significant and independent effects of histological stage (i + t < or = or > 2) and time to borderline changes (< or = or > 3 months after transplant) on serum creatinine levels at 1 year from borderline changes episodes (respectively, p = 0.04 and p = 0.02) and only a significant effect of time to borderline changes on serum creatinine levels at 2 years (p = 0.005). Renal function at 1 year and 2 years as 5- and 8-year graft survival were not significantly different in the group of patients treated with antirejection therapy (T group, n = 49) compared with the untreated group (UT group, n = 42). This study strongly suggests that borderline changes with histological score (i + t) > 2 and late episodes of borderline changes should be considered to be of poor prognosis.  相似文献   
98.
99.
100.
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