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   575篇
  免费   39篇
  国内免费   19篇
耳鼻咽喉   2篇
儿科学   44篇
妇产科学   3篇
基础医学   52篇
口腔科学   19篇
临床医学   59篇
内科学   214篇
皮肤病学   3篇
神经病学   30篇
特种医学   44篇
外科学   62篇
综合类   11篇
预防医学   25篇
眼科学   4篇
药学   27篇
中国医学   1篇
肿瘤学   33篇
  2023年   3篇
  2022年   5篇
  2021年   6篇
  2020年   7篇
  2019年   8篇
  2018年   9篇
  2017年   5篇
  2016年   11篇
  2015年   15篇
  2014年   13篇
  2013年   25篇
  2012年   20篇
  2011年   18篇
  2010年   30篇
  2009年   34篇
  2008年   20篇
  2007年   24篇
  2006年   30篇
  2005年   18篇
  2004年   25篇
  2003年   15篇
  2002年   24篇
  2001年   15篇
  2000年   11篇
  1999年   10篇
  1998年   32篇
  1997年   26篇
  1996年   22篇
  1995年   14篇
  1994年   16篇
  1993年   6篇
  1992年   6篇
  1991年   5篇
  1990年   3篇
  1989年   4篇
  1988年   11篇
  1987年   6篇
  1986年   13篇
  1985年   11篇
  1984年   10篇
  1983年   6篇
  1982年   11篇
  1981年   3篇
  1980年   4篇
  1977年   2篇
  1974年   2篇
  1971年   3篇
  1970年   2篇
  1874年   2篇
  1871年   2篇
排序方式: 共有633条查询结果,搜索用时 15 毫秒
71.
We investigate whether symptoms of pressure, tightness, and/or pain in the chest, neck, and/or throat after administration of the 5HT1B/1D agonist avitriptan were associated with objective impairment of the myocardial function on 12-lead electrocardiogram (ECG), continuous ECG (Holter) monitoring, and echocardiography. Migraine sufferers who in two-thirds of alt attacks treated with sumatriptan had experienced chest/throat/neck symptoms were chosen for study. Baseline measures included vital signs, a 12-lead ECG and an echocardiogram. Patients ( n =51) who had no clinically significant abnormality at baseline received a high dose (150 mg) of avitriptan orally outside of a migraine attack. If pressure, tightness, and/or pain in the chest, neck, and/or throat occurred, an ECG was obtained, and a repeat echocardiogram was done while the symptoms were present in order to monitor for impairment of myocardial function. If symptoms of these types did not occur within 60 min after administration of the study drug, a second echocardiogram was obtained. Forty-five patients (88%) reported at least one adverse event and 23 (45%) experienced pressure, tightness, and/or pain in the chest, neck, and/or throat after administration of avitriptan. No clinically significant myocardial abnormalities were observed in any patient, even in those who had experienced the targeted symptoms. No other serious adverse event occurred. We concluded that the typical 5HT1B/1D agonist-induced chest/throat/neck symptoms are most unlikely to be of cardiovascular origin.  相似文献   
72.

Background  

The use of spirometry for early detection of chronic obstructive pulmonary disease (COPD) is still an issue of debate, particularly because of a lack of convincing evidence that spirometry has an added positive effect on smoking cessation. We hypothesise that early detection of COPD and confrontation with spirometry for smoking cessation may be effective when applying an approach we have termed "confrontational counselling"; a patient-centred approach which involves specific communication skills and elements of cognitive therapy. An important aspect is to confront the smoker with his/her airflow limitation during the counselling sessions. The primary objective of this study is to test the efficacy of confrontational counselling in comparison to regular health education and promotion for smoking cessation delivered by specialized respiratory nurses in current smokers with previously undiagnosed mild to moderate airflow limitation.  相似文献   
73.
In our study, we evaluated the effectiveness of upper gastrointestinal (GI) endoscopy as an instrument for early gastric cancer (GC) detection in Lynch syndrome (LS) patients by analyzing data from the registry of the German Consortium for Familial Intestinal Cancer. In a prospective, multicenter cohort study, 1128 out of 2009 registered individuals with confirmed LS underwent 5176 upper GI endoscopies. Compliance was good since 77.6% of upper GI endoscopies were completed within the recommended interval of 1 to 3 years. Forty‐nine GC events were observed in 47 patients. MLH1 (n = 21) and MSH2 (n = 24) mutations were the most prevalent. GCs in patients undergoing regular surveillance were diagnosed significantly more often in an early‐stage disease (UICC I) than GCs detected through symptoms (83% vs 25%; P = .0231). Thirty‐two (68%) patients had a negative family history of GC. The median age at diagnosis was 51 years (range 28‐66). Of all GC patients, 13 were diagnosed at an age younger than 45. Our study supports the recommendation of regular upper GI endoscopy surveillance for LS patients beginning no later than at the age of 30.  相似文献   
74.
女性护理专业学生心理健康相关因素分析   总被引:1,自引:0,他引:1  
目的:分析护理专业学生心理健康的影响因素。方法:于2005-12-01/15按整群抽样法抽取西安市高校在读的护理专业学生515名作为被调查对象。症状自评量表总分≥187为高分组,总分≤116为低分组。高分组与低分组配比的条件是均为女性,年龄相差不超过3岁。采用症状自评量表、简易应对方式问卷、自尊量表、护理专业学生相关状况调查表进行问卷调查。对调查变量进行单因素和多因素Logistic回归分析。结果:共发放问卷515份,其中2名学生生病未填写调查表,应答率为99.6%。调查中有效问卷共507份,有效率为98.8%。症状自评量表总分高分组与低分组学生各100名。①护理专业学生心理健康相关个人因素(计量变量)单因素分析结果:高分组积极应对、自尊水平得分明显低于低分组(20.47±5.02,22.15±6.02;25.91±3.60,30.96±3.25),差异有显著性意义(P<0.05,P<0.01)。高分组消极应对得分明显高于低分组(12.57±4.08,8.00±4.12),差异有显著性意义(P<0.01)。②护理专业学生心理健康相关个人因素(二分类变量)单因素分析结果表明,高分组与低分组比较差异有显著性的因素有独生子女、远离家人、孤独、学习压力大、担心拿不到学位、自我实现需要的满足、经常被人误会、受人歧视、失恋、有知心朋友、无处倾诉苦恼、睡眠型态紊乱、近1年来本人健康改变、适应新环境、经常参加体育活动、担心毕业分配、现有最担心的事情。③多因素分析显示,学习压力大(OR=10.017)、近1年来本人健康改变(OR=4.384)为护理专业学生心理健康状况不良的独立危险因素,而自我实现需要的满足(OR=0.037)、高水平自尊(OR=0.357)是保护因素。结论:护理专业学生心理健康状况与教育、成长、社会环境等多方面因素相关,其心理健康干预需考虑学生的个人因素有针对性地进行。  相似文献   
75.
76.
An elderly man with thymoma, myasthenia gravis, and hypogammaglobulinemia developed profuse watery diarrhea. Infusions of gamma-globulin caused the diarrhea to resolve. The patient succumbed to fulminant bronchopneumonia. At necropsy he was found to have widespread cytomegalovirus infection with duodenal and ileal ulceration, subtotal villous atrophy, marked nonspecific inflammation of the small intestine and bronchopneumonia. In addition Herpes simplex infection and invasive candidiasis were present. Patients with immunodeficiency are susceptible to a variety of gastrointestinal pathogens, particularly viral.  相似文献   
77.
78.
79.
Zusammenfassung Eine 38-j?hrige Patientin, die seit 2 Jahren unter Gelenkbeschwerden litt, pr?sentierte sich mit Dysphagie, Gewichtsverlust, Pneumonie und mit Handgelenks-, Kniegelenks- sowie Sprunggelenkergüssen. In den 4 Wochen vor der station?ren Aufnahme hatten sich ausgepr?gte Trommelschl?gelfinger gebildet. Weder in der intestinoskopischen noch in der bronchoskopischen Diagnostik zeigte sich eine intralumin?re Tumorbildung bei computertomographisch nachgewiesener mediastinaler Raumforderung. Histologisch best?tigte sich der für das Alter der Patientin ungew?hnliche Befund eines zentral sitzenden prim?ren Adenokarzinoms der Lunge. Vor diesem Hintergrund und nach radiologischen Kriterien konnte eine hypertrophe Osteoarthropathie diagnostiziert werden, die in 10–20% der F?lle eines Lungenadenokarzinoms als Paraneoplasie auftritt und in diesem Fall die erste klinische Manifestation der Tumorerkrankung bildete. Die paraneoplastische hypertrophe Osteoarthropathie war unter Chemotherapie gut rückl?ufig. Dieser Fall illustriert die klinische Bedeutung von paraneoplastischen Symptomkonstellationen als Entscheidungshilfe für die frühzeitige Diagnostik neoplastischer Erkrankungen.  相似文献   
80.
Because there is no consensus regarding the precise distribution of induced endothelial tissue factor (TF), we studied TF activity in and on tumor necrosis factor alpha-stimulated cultured human umbilical vein endothelial cells (ECs) and their underlying matrix. TF was mainly expressed on the cell surface. Only small traces were found on the apical surface suggesting that TF is predominantly located on the basolateral side of the cell membrane. The presence of TF on the cell surface was confirmed by flow cytometry. Subendothelial TF activity appeared to be dependent upon the procedure used to remove the stimulated EC monolayer. Whereas ammonium hydroxide or hypotonic lysis resulted in relatively high levels of matrix-associated TF, virtually no TF was found on the matrix after mild enzymatic detachment of stimulated ECs. Cell removal with EDTA resulted in intermediate levels of matrix-associated TF. Neither the enzymatic treatment nor EDTA degraded or removed this TF activity. Similar patterns were observed for matrix-associated TF antigen and EC surface markers. Electron microscopic analysis showed cell fragments on the matrix after monolayer lysis. The findings strongly suggest that induced endothelial TF associated with the subendothelial matrix actually represents TF on EC remnants.  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