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   736篇
  免费   49篇
  国内免费   1篇
耳鼻咽喉   4篇
儿科学   40篇
妇产科学   5篇
基础医学   113篇
口腔科学   13篇
临床医学   82篇
内科学   110篇
皮肤病学   9篇
神经病学   23篇
特种医学   132篇
外科学   111篇
综合类   18篇
预防医学   63篇
眼科学   11篇
药学   43篇
  1篇
肿瘤学   8篇
  2023年   6篇
  2021年   7篇
  2020年   8篇
  2019年   7篇
  2018年   6篇
  2017年   6篇
  2016年   13篇
  2015年   23篇
  2014年   12篇
  2013年   21篇
  2012年   36篇
  2011年   44篇
  2010年   26篇
  2009年   29篇
  2008年   40篇
  2007年   15篇
  2006年   31篇
  2005年   27篇
  2004年   20篇
  2003年   16篇
  2002年   13篇
  2001年   17篇
  2000年   10篇
  1999年   10篇
  1998年   22篇
  1997年   25篇
  1996年   22篇
  1995年   17篇
  1994年   14篇
  1993年   18篇
  1992年   9篇
  1991年   11篇
  1990年   14篇
  1989年   15篇
  1988年   19篇
  1987年   16篇
  1986年   12篇
  1985年   16篇
  1984年   7篇
  1983年   4篇
  1982年   14篇
  1981年   12篇
  1978年   6篇
  1974年   4篇
  1973年   4篇
  1972年   5篇
  1967年   4篇
  1959年   4篇
  1958年   4篇
  1956年   4篇
排序方式: 共有786条查询结果,搜索用时 0 毫秒
1.
2.
3.
Solitary bronchioloalveolar carcinoma: CT criteria   总被引:14,自引:0,他引:14  
The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis.  相似文献   
4.
5.
6.
7.
8.
Abstract— The anticonvulsant action of midazolam and clonazepam was studied in 168 immature rats in three age groups (12, 18 and 25 days old). Epileptic after-discharges of the spike-and-wave type accompanied by clonic seizures of facial and forelimb muscles induced by stimulation of sensorimotor cortex were used as a model. The solvent used for clonazepam exhibited a tendency to anticonvulsant action in 12-day-old rats. On the contrary, a proconvulsant action was seen in 25-day-old animals. The action of both benzodiazepines was identical and did not change substantially during development. The highest dose used (1 mg kg?1, i.p.) shortened the duration of epileptic after-discharges, the two lower doses (0·1 and 0·02 mg kg?1, i.p.) suppressed the progressive prolongation with repeated stimulations seen under control conditions. Motor correlates of stimulation remained practically uninfluenced by the two benzodiazepines, myoclonic seizures accompanying epileptic after-discharges were attenuated by the highest dose of both drugs.  相似文献   
9.
Septo-optic dysplasia: MR imaging   总被引:5,自引:0,他引:5  
Barkovich  AJ; Fram  EK; Norman  D 《Radiology》1989,171(1):189-192
Septo-optic dysplasia is the diagnosis when optic nerve hypoplasia is seen in conjunction with dysgenesis of the septum pellucidum. Nearly two-thirds of these patients have hypothalamic-pituitary dysfunction, and half have schizencephaly. The disorder is difficult to classify because of the diversity of clinical and pathologic manifestations. Magnetic resonance images of 11 patients with clinical and radiographic evidence of septo-optic dysplasia were reviewed retrospectively. The "syndrome" appears to include two subsets of patients whose abnormalities have different embryogenesis and neuropathologic findings. The existence of these two subsets helps to explain the diversity of the clinical and radiologic findings.  相似文献   
10.
BACKGROUND: Laboratory animal allergy is a common illness among workers exposed to laboratory animals and can progress to symptoms of asthma. OBJECTIVES: This study evaluates the continuum of disease from allergy symptoms to asthma symptoms in a dynamic cohort of workers exposed to animals in a pharmaceutical company. METHODS: Data arose from annual questionnaires administered to workers in a surveillance program established to monitor exposure to animals and the development of allergy. The life-table method was used to compare asthma-free survival between workers with and without symptoms of allergy. A Cox proportional hazards model was used to examine the effects of covariates on the development of asthma. RESULTS: A total of 603 workers contributed 2527.4 person-years to the study over the 12.3-year period. The probabilities of experiencing asthma symptoms by the 11th year of follow-up were 0.367 for workers with allergy symptoms and 0.052 for those without allergy symptoms. The hazard ratio for asthma symptoms when comparing workers with and without allergy symptoms was 7.39 (95% CI, 3.29-16.60) after adjustment for sex and family history of allergy. Female subjects developed asthma at a rate 3.4 times that of male subjects. CONCLUSIONS: This study supports the hypothesis that laboratory animal allergy symptoms are a major risk factor for the development of asthma. It also suggests a heightened risk of asthma for women who work with laboratory animals, a finding that has not been previously reported.  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