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   1696篇
  免费   102篇
  国内免费   9篇
耳鼻咽喉   17篇
儿科学   49篇
妇产科学   48篇
基础医学   197篇
口腔科学   7篇
临床医学   153篇
内科学   523篇
皮肤病学   12篇
神经病学   144篇
特种医学   60篇
外科学   287篇
综合类   20篇
预防医学   72篇
眼科学   107篇
药学   67篇
中国医学   3篇
肿瘤学   41篇
  2023年   7篇
  2022年   10篇
  2021年   33篇
  2020年   24篇
  2019年   17篇
  2018年   24篇
  2017年   43篇
  2016年   37篇
  2015年   38篇
  2014年   58篇
  2013年   99篇
  2012年   117篇
  2011年   118篇
  2010年   65篇
  2009年   66篇
  2008年   104篇
  2007年   107篇
  2006年   116篇
  2005年   104篇
  2004年   89篇
  2003年   80篇
  2002年   88篇
  2001年   27篇
  2000年   25篇
  1999年   26篇
  1998年   20篇
  1997年   22篇
  1996年   10篇
  1995年   12篇
  1994年   11篇
  1993年   14篇
  1992年   10篇
  1991年   12篇
  1990年   17篇
  1989年   18篇
  1988年   13篇
  1987年   8篇
  1986年   13篇
  1985年   14篇
  1984年   14篇
  1983年   13篇
  1982年   6篇
  1981年   7篇
  1978年   4篇
  1977年   4篇
  1976年   4篇
  1975年   6篇
  1974年   6篇
  1972年   3篇
  1971年   4篇
排序方式: 共有1807条查询结果,搜索用时 15 毫秒
91.
AIM: Studies in rehabilitation research put great value on patients' self-assessment. Patients with hip or knee diseases who need an orthopaedic rehabilitation suffer mainly pain, reduction of walking distance and other disabilities that impact on the activities of daily life. The Lequesne scores for the hip and knee are an indicator to show the degree of disabilities. The aim of the study was to prove that the Lequesne indices are reliable instruments for the individual to express the outcome of rehabilitation. We tested the Lequesne indices in daily clinical work, in the handling and in the acceptance. METHOD: Since May 1999 the rehabilitation center Bad Eilsen uses the Lequesne questionnaires as self-report questionnaire instruments for patients with hip and knee disabilities. 145 patients with hip and 122 patients with knee diseases filled in the questionnaires correctly and handed them back. RESULTS: The Lequesne indices are able to show developments in both directions; improvement as well as change for the worse. The Lequesne questionnaires are helpful to complete the common clinical parameters. CONCLUSION: Using the Lequesne questionnaires as a self-report instrument in our daily routine we are able to obtain a good reflection of individual health condition and the quality of outcome in rehabilitation.  相似文献   
92.
DBCP who are aware of their increased risk of developing breast cancer may suffer from high emotional distress. Chronic stress may interfere with NCA and low NCA is associated with increased cancer risk. We studied 80 DBCP and 47 age- and education-matched healthy females (controls). Heparinized venous blood (30 ml) was drawn from all subjects between 8 and 9 A.M., and each participant answered a set of psychologic questionnaires. In addition, the first-morning urine sample was collected. DBCP scored significantly higher in emotional distress compared to controls. Levels of stress hormones in DBCP were higher and in vitro secretion of IL-2, IL-12 and IFN-gamma lower compared to controls. NCA against NK-resistant (MCF-7, COLO-205, U937) and NK-sensitive (K562) cell lines was significantly lower in DBCP and much less augmented by in vitro preincubation with IL-2 or IL-12 compared to controls. NCA and in vitro Th1 cytokine secretion were inversely correlated with the degree of emotional distress and the level of stress hormones in blood or urine. High emotional distress and elevated levels of stress hormones are associated with impaired immune surveillance functions in DBCP. This may contribute to the increased risk of DBCP to develop breast cancer. An interventional trial to enhance coping and reduce stress levels may help to decrease the risk for breast cancer onset in DBCP.  相似文献   
93.
94.
BACKGROUND: New-onset atrial fibrillation after coronary artery bypass grafting is common. Medical therapy includes various antiarrhythmic drugs to control heart rate and restore sinus rhythm. The purpose of this study was to determine the duration of antiarrhythmic therapy after discharge from the hospital. METHODS: One hundred twenty-nine patients in whom new atrial fibrillation after coronary artery bypass grafting developed and successfully reverted to sinus rhythm were prospectively randomized at dismissal to receive antiarrhythmic therapy for 1 week (group A; n = 44), 3 weeks (group B; n = 42), or 6 weeks (group C; n = 43). Patients were followed up for an additional 4 weeks after discontinuation of antiarrhythmic therapy for detection of recurrent atrial fibrillation. RESULTS: The incidence of new atrial fibrillation during the study period was 21.2% (256/1206). Among the 129 patients who consented to the study, conversion to sinus rhythm was accomplished with the following medications: amiodarone (group A, 82%; group B, 93%; group C, 88%; P = .29), digoxin (group A, 16%; group B, 7%; group C, 7%; P = .29), beta-blockers (group A, 27%; group B, 19%; group C, 14%; P = .30), calcium channel blockers (group A, 2%; group B, 2%; group C, 0%; P = .60), quinidine (group A, 2%; group B, 2%; group C, 7%; P = .44), and procainamide (group A, 4.5%; group B, 2%; group C, 0%; P = .37). Follow-up was completed in 128 patients (99.2%). There was no significant difference in the recurrence of atrial fibrillation among groups (0%, 2%, and 0% for groups A, B, and C, respectively). CONCLUSIONS: Patients with new atrial fibrillation after coronary artery bypass grafting, converted to normal sinus rhythm before hospital discharge, have a benign course. Antiarrhythmic therapy as short as 1 week may be appropriate in these patients.  相似文献   
95.
Second-look laparotomy is one of the mainstays of surgical treatment of acute mesenteric ischemia (AMI). The aim of this study was to analyze its role in the survival of patients with infarcted gangrenous bowel resulting from AMI. A retrospective chart review of all patients admitted over the study period was undertaken. The study population consisted of 41 patients with clinical evidence of peritonitis and gangrenous, perforated bowel on surgical exploration. Outcome was compared among patients who underwent second-look laparotomy and those who did not. Fifteen patients with an American Society of Anesthesiologists (ASA) score of less than 4 underwent second-look laparotomy. Six patients had residual necrotic bowel that required additional resection. Only one (17%) of them survived. Of the nine remaining patients, who had no evidence of necrosis, only two survived (22%). Overall survival in this group was 20%. Twenty-six patients were managed without second-look laparotomy. Nine of them, with an ASA score of 4–5, died soon after the operation. The decision not to operate on the remaining 17 patients with an ASA score <4 was made by an experienced surgeon. Eleven of those patients (65%) survived. Overall survival in the non-second-look group was 42%. Excluding the early deaths, the survival in the non re-explored group was significantly higher than in the second-look group (65% vs. 20%, p = 0.011). A selective approach to the surgical treatment of acute mesenteric ischemia based on the sound clinical judgment of an experienced surgeon may be as appropriate as its universal application.  相似文献   
96.
Abstract Background: Mitral valve replacement in patients who previously had undergone aortic valve replacement is a technical challenge. The rigid aortic prosthesis limits visualization of the anterior mitral annulus and placement of sutures. Methods: Reoperative mitral valve replacement was performed in five patients after aortic valve replacement. Two patients underwent resternotomy to allow verification of normal aortic prosthetic valve function. Anterolateral right thoracotomy was used for reentry in the remaining three patients. Exposure of the anterior mitral annulus was accomplished by initial traction on the intact anterior leaflet, with resection of this leaflet only after placement of sutures. Results: All patients survived the surgical procedure and are well 2 to 30 months after operation. In one patient it was impossible to open one cusp of the mitral prosthesis, nor was it possible to rotate the valve. The valve was reimplanted, but sutures were tied only after testing for full free cusp motion. Conclusions: When appropriate, right thoracotomy incision offers excellent exposure of the mitral valve with minimal dissection. Placement of sutures along the anterior portion of the annulus is facilitated by traction downwards on the anterior leaflet. Full range of motion of the prosthetic cusps should be verified before tying the sutures.  相似文献   
97.
OBJECTIVE: Evaluation of fetal cardiac contractility by two-dimensional ultrasonography and construction of nomograms of area shortening fraction, end-diastolic area and end-systolic area of fetal cardiac ventricles during uncomplicated pregnancy. MATERIALS AND METHODS: Fetal echocardiography was performed on 160 pregnant women between 14 and 28 weeks' gestation. Measurements were taken on the four-chamber view. The area of each ventricle was measured by tracing the endocardium at the end of systole and at the end of diastole. Area shortening fraction was calculated by the following formula: SF = (Ad - As)/Ad (SF--area shortening fraction, Ad--end-diastolic ventricular area, As--end-systolic ventricular area). RESULTS: A statistically significant increase in normal fetal area shortening fraction, end-diastolic area and end-systolic area of both ventricles with advancing gestational age was established. There were no significant differences in the area shortening fraction between right and left ventricles. CONCLUSIONS: Area shortening fraction shows good correlation with gestational age. Nomogram of area shortening fraction, end-diastolic area and end-systolic area of both ventricles can be used as the reference for evaluation of ventricle size and cardiac contractility in normal and pathological cases.  相似文献   
98.
Infection of mice with mouse hepatitis virus (MHV) strain A59 results in acute encephalitis, hepatitis, and chronic demyelinating disease. T lymphocytes play an important role in MHV infection, and costimulatory signals are an important component of T cell function. To elucidate the role of the main costimulatory molecule, CD28, in MHV pathogenesis and demyelination, we examined the kinetics of MHV-A59 infection in CD28 knockout mice. MHV-A59-infected CD28 knockout mice developed acute encephalitis and hepatitis, and the same degree of chronic demyelination as normal C57Bl/6 (B6) mice. Thus, CD28, the costimulatory T cell molecule, is not required for MHV infection and MHV-induced demyelination.  相似文献   
99.
PURPOSE: To describe the surgical management and histopathologic and immunohistochemical findings in corneal plaques of shield ulcers in vernal keratoconjunctivitis. PATIENTS AND METHODS: Three children (ages 4, 7.5, and 9) presented with corneal plaques unresponsive to conservative systemic and topical medical treatment. Plaques were scraped under general anesthesia, and soft bandage contact lenses were placed. The excised tissue was evaluated by histopathology and immunohistochemistry. RESULTS: During surgery, plaques were found to extend beyond the ulcer margins. Histopathology revealed granular, deeply-eosinophilic, laminar material, firmly attached to the Bowman layer in all cases. Immunohistochemistry confirmed this to be eosinophil-derived major basic protein (MBP). After surgical removal, complete epithelization was evident within 1-4 weeks in all cases. CONCLUSIONS: Corneal plaque is a rare complication of vernal keratoconjunctivitis. These plaques usually do not resolve with standard conservative measures. Failure to epithelialize may be a result of the plaque material extending below the edges of adjacent epithelium. We suggest that MBP plaques precipitate on the denuded stromal bed, thereby playing a pathogenic role in nonhealing shield ulcers.  相似文献   
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