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   3678294篇
  免费   259907篇
  国内免费   9577篇
耳鼻咽喉   49424篇
儿科学   121613篇
妇产科学   100622篇
基础医学   517546篇
口腔科学   104053篇
临床医学   336712篇
内科学   716460篇
皮肤病学   86223篇
神经病学   298922篇
特种医学   139646篇
外国民族医学   957篇
外科学   547715篇
综合类   78069篇
现状与发展   9篇
一般理论   1458篇
预防医学   284533篇
眼科学   85147篇
药学   267993篇
  12篇
中国医学   8110篇
肿瘤学   202554篇
  2021年   28875篇
  2019年   29608篇
  2018年   41977篇
  2017年   32104篇
  2016年   36517篇
  2015年   41299篇
  2014年   57256篇
  2013年   85260篇
  2012年   115327篇
  2011年   121873篇
  2010年   72924篇
  2009年   69269篇
  2008年   113337篇
  2007年   120493篇
  2006年   122082篇
  2005年   117002篇
  2004年   112294篇
  2003年   107978篇
  2002年   104085篇
  2001年   177400篇
  2000年   181511篇
  1999年   152850篇
  1998年   43733篇
  1997年   38490篇
  1996年   38634篇
  1995年   37377篇
  1994年   34122篇
  1993年   32017篇
  1992年   118363篇
  1991年   114137篇
  1990年   110387篇
  1989年   106703篇
  1988年   97637篇
  1987年   95538篇
  1986年   89751篇
  1985年   85693篇
  1984年   63851篇
  1983年   54221篇
  1982年   31761篇
  1979年   56438篇
  1978年   39599篇
  1977年   33700篇
  1976年   31380篇
  1975年   33241篇
  1974年   39632篇
  1973年   37885篇
  1972年   35386篇
  1971年   32876篇
  1970年   30360篇
  1969年   29017篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
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   
83.
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   
84.
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   
85.
86.
87.
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   
88.
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   
89.
90.
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