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   3622562篇
  免费   256344篇
  国内免费   9493篇
耳鼻咽喉   48862篇
儿科学   120040篇
妇产科学   99514篇
基础医学   509082篇
口腔科学   102241篇
临床医学   331595篇
内科学   706311篇
皮肤病学   85472篇
神经病学   293226篇
特种医学   137535篇
外国民族医学   941篇
外科学   541095篇
综合类   77809篇
现状与发展   8篇
一般理论   1393篇
预防医学   277090篇
眼科学   83923篇
药学   264331篇
  12篇
中国医学   7995篇
肿瘤学   199924篇
  2019年   28754篇
  2018年   40964篇
  2017年   31225篇
  2016年   35531篇
  2015年   40259篇
  2014年   55716篇
  2013年   83226篇
  2012年   112235篇
  2011年   118788篇
  2010年   71106篇
  2009年   67476篇
  2008年   110625篇
  2007年   117722篇
  2006年   119316篇
  2005年   114478篇
  2004年   110154篇
  2003年   105971篇
  2002年   102367篇
  2001年   175830篇
  2000年   179995篇
  1999年   151371篇
  1998年   43044篇
  1997年   37911篇
  1996年   38041篇
  1995年   36888篇
  1994年   33725篇
  1993年   31598篇
  1992年   117156篇
  1991年   112995篇
  1990年   109373篇
  1989年   105679篇
  1988年   96634篇
  1987年   94650篇
  1986年   88865篇
  1985年   84831篇
  1984年   63250篇
  1983年   53661篇
  1982年   31487篇
  1981年   28064篇
  1979年   55932篇
  1978年   39280篇
  1977年   33418篇
  1976年   31160篇
  1975年   32979篇
  1974年   39336篇
  1973年   37593篇
  1972年   35120篇
  1971年   32596篇
  1970年   30119篇
  1969年   28791篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
51.
BACKGROUND: Radioiodine therapy (RIT) combined with glucocorticoids is an effective therapy for Graves' disease, but it is debatable whether glucocorticoids should be applied in patients without Graves' ophthalmopathy (GO). METHODS: The effect of 0.4 - 0.5 mg prednisone every second day over a period of 5 weeks after RIT was monitored over a follow-up period of at least 12 months after RIT. A questionnaire was sent to 186 consecutive patients without GO concerning eye symptoms after RIT. 148 patients (80 %) answered. If eye symptoms had occurred after RIT, additional clinical examination was carried out at our outpatient clinic. The primary endpoint was the absence or onset of GO within the first year after RIT. RESULTS: Within 12 months after RIT the examination confirmed GO in 5 out of 148 patients (3.4 %). In all cases the symptoms were transient. No adverse reaction to the use of prednisone after RIT was noted. CONCLUSIONS: The risk of new GO in the first year after RIT was low and the clinical course of GO was mild when RIT was combined with a low-dose glucocorticoid regimen. Preventive administration of glucocorticoids can therefore be recommended in patients with Graves' disease even without evident GO.  相似文献   
52.
The present study compared four different sites and conditions for the measurement of maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) in 38 spontaneous breathing tracheotomised patients. Of the patients, 28 had chronic obstructive pulmonary disease (COPD). The four different conditions were: 1) through a cuff inflated cannula (condition A); 2) through the mouth with a deflated cannula (condition B); 3) through the mouth with a phonetic uncuffed cannula (condition C); and 4) through the mouth after stoma closure (condition D). Five trials in each condition were performed using a standardised method. The measurement of both MIP and MEP differed significantly depending on the condition of measurement. MIP taken in condition A was significantly higher when compared with conditions B, C and D. MEP in condition A was significantly higher when compared with condition B and D. In condition A the highest frequency of the best measurement of MIP and MEP was observed at the fourth and fifth effort, respectively. The same results were obtained after the selection of only COPD patients. In conclusion, respiratory muscle assessment differs significantly depending on measurement condition. Measurement through inflated cannula tracheotomy yields higher values of both maximal inspiratory and maximal expiratory pressure.  相似文献   
53.
Severe tuberculosis (TB) requiring intensive care unit (ICU) care is rare but commonly known to be of markedly bad prognosis. The present study aimed to describe this condition and to determine the mortality rate and risk factors associated with mortality. Patients with confirmed TB admitted to ICU between 1990 and 2001 were retrospectively identified and enrolled. Clinical, radiological and bacteriological data at admission and during hospital stay were recorded. A multivariate analysis was performed to identify the predictive factors for mortality. A total of 58 TB patients (12 females, mean age 48 yrs) admitted to ICU were included. Mean Acute Physiology and Chronic Health Evaluation (APACHE) II score at admission was 13.1+/-5.6 and 22 of 58 (37.9%) patients required mechanical ventilation. The in-hospital mortality was 15 of 58 (25.9%); 13 (22.4%) patients died in the ICU. The mean survival of patients who died was 53.6 days (range 1-229), with 50% of the patients dying within the first 32 days. The factors independently associated with mortality were: acute renal failure, need for mechanical ventilation, chronic pancreatitis, sepsis, acute respiratory distress syndrome, and nosocomial pneumonia. These data indicate a high mortality of patients with tuberculosis requiring intensive care unit care and identifies new independently associated risk factors.  相似文献   
54.
55.
Summary: A female patient with isovaleric acidaemia had a successful outcome from pregnancy.  相似文献   
56.
    
Ohne Zusammenfassung  相似文献   
57.
58.
59.
OBJECTIVE: Spinal reflexes from hand to wrist muscles were investigated in writer's cramp. METHODS: Stimulus-triggered rectified EMG averages after ulnar nerve and cutaneous stimulation, in wrist flexors and extensors during tonic contraction, were compared in 18 controls and 19 patients. RESULTS: On the patient dystonic side, ulnar-induced EMG suppression was decreased in wrist extensors, and facilitation in wrist flexors modified dependent on the dystonic wrist posture during writing. No change was found on the patient non-dystonic side. Cutaneous stimulation increased wrist flexor EMG on both sides of the patients with normal wrist posture during writing, but had no effect in controls and patients with abnormal wrist posture. CONCLUSIONS: Comparison between cutaneous and mixed nerve stimuli suggests that spindle afferents from intrinsic hand muscles may mediate patients' ulnar-induced EMG modulations. Abnormal proprioceptive control was only observed on dystonic side, while bilateral unusual cutaneous control was found in patients. Changes in spinal transmission were partly related to the dystonic wrist posture, suggesting that systems involved in sensory processing can be differentially altered in writer's cramp. SIGNIFICANCE: Changes in spinal transmission, probably related to peripheral and/or cortical inputs, might either take part in primary or adaptive mechanisms underlying writer's cramp.  相似文献   
60.
Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis.  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