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   588篇
  免费   29篇
  国内免费   69篇
耳鼻咽喉   11篇
儿科学   63篇
妇产科学   8篇
基础医学   83篇
口腔科学   10篇
临床医学   80篇
内科学   115篇
皮肤病学   4篇
神经病学   55篇
特种医学   56篇
外科学   54篇
综合类   13篇
预防医学   35篇
眼科学   8篇
药学   57篇
肿瘤学   34篇
  2024年   2篇
  2023年   6篇
  2022年   8篇
  2021年   6篇
  2020年   5篇
  2019年   10篇
  2018年   4篇
  2017年   6篇
  2016年   7篇
  2015年   15篇
  2014年   15篇
  2013年   26篇
  2012年   22篇
  2011年   19篇
  2010年   20篇
  2009年   14篇
  2008年   14篇
  2007年   58篇
  2006年   17篇
  2005年   28篇
  2004年   12篇
  2003年   20篇
  2002年   21篇
  2001年   25篇
  2000年   30篇
  1999年   24篇
  1998年   28篇
  1997年   22篇
  1996年   23篇
  1995年   18篇
  1994年   7篇
  1993年   10篇
  1992年   11篇
  1991年   18篇
  1990年   16篇
  1989年   18篇
  1988年   12篇
  1987年   9篇
  1986年   7篇
  1985年   4篇
  1984年   7篇
  1981年   2篇
  1980年   3篇
  1979年   7篇
  1978年   6篇
  1977年   10篇
  1975年   2篇
  1974年   2篇
  1973年   3篇
  1972年   2篇
排序方式: 共有686条查询结果,搜索用时 0 毫秒
11.
Gangrenous cholecystitis is a serious complication of acute cholecystitis and is associated with increased morbidity and mortality rates. We report a case in which the diagnosis was suggested by ultrasound, but cholecystectomy delayed due to atypical clinical presentation and a false negative radionuclide biliary scan.  相似文献   
12.
Demographic, clinical and laboratory data were retrospectively collected from records of 146 cases of CT fluoroscopy‐guided chemical lumbar sympathectomy for the palliation of inoperable peripheral vascular disease (PVD) between January 1997 and August 1999. Of these, 16% had claudication, 39% had rest pain and 44% had ischaemic ulcers or gangrene. Seventy‐three percent of elective cases were outpatients. At 3 months, 27 cases were lost to follow up, leaving 119 cases. Within 3 months, improvement, defined as doubling of the walking distance, cessation of rest pain or healing of ulcers, occurred in 30.3% of cases. No change was observed in 45.4% of cases and 24.3% of cases deteriorated. Patients with ulcers or gangrene had significantly poorer results than those without any ischaemic lesions, as only 19% versus 39% of patients improved (P < 0.05). The presence of hypertension, diabetes mellitus, hyperlipidaemia and smoking had no value in predicting clinical outcome (P > 0.05). There were no major complications noted. CT fluoroscopy‐guided chemical lumbar sympathectomy is safe and effective, with a complication rate of less than 1%, and efficacy of at least 30% measured within 3 months. It is a simple and minimally invasive procedure, easily performed on an outpatient basis. CT fluoroscopy‐guided chemical lumbar sympathectomy should be considered for all patients in the early stages of inoperable PVD.  相似文献   
13.
Background: The in‐hospital Utstein Guidelines may be used to evaluate resuscitation strategies. This study utilized the Utstein template prospectively to examine changes in outcome and outcome‐related factors after resuscitation outside critical care areas over a 10‐year period. Methods: Seinäjoki Central Hospital (460 beds) is a secondary hospital in Finland with acute care activities. In 1993, the in‐hospital cardiac arrest management was remodelled; an intensive care unit‐based resuscitation team was formed and prospective data collection began (modified according to the Utstein Guidelines in 1997). An analysis of resuscitation attempts outside critical care areas between 1993 and 2002 was performed. To monitor developments, the patients were divided into two groups (first period, 1993–97; second period, 1998–2002). Variables independently associated with survival were identified using multiple logistic regression analysis. Results: During the 10‐year period, resuscitation was attempted in 183 patients. Survival to discharge was 6% during the first period and 16% during the second (P = 0.048). The corresponding figures for survival at 1 year from the event were 3% and 10% (P = 0.064). Independent predictors of survival were ventricular fibrillation or ventricular tachycardia as the initial rhythm [odds ratio (OR), 9.8; confidence interval (CI), 3.2–30.3] and cardiac arrest occurring during the second period (OR, 3.3; CI, 1.1–10.1). Conclusion: Prospective Utstein style data collection proved to be a valuable tool for the evaluation of management and outcome following in‐hospital cardiac arrest. Increased survival was seen over 10 years outside critical care areas. Organizational changes, including cardiopulmonary resuscitation training for ward personnel and standardized resuscitation management, may have contributed to this change.  相似文献   
14.
The quantitative (anti-Hib capsular polysaccharide antibody concentrations; anti-HibPS) and qualitative (bactericidal activity and avidity) aspects in immune responses to Haemophilus influenzae type b polyribosyl ribitol phospshate-CRM(197) conjugate vaccine (HibCV; HibTiter) were evaluated in 66 HIV infected children not receiving anti-retroviral therapy and 127 HIV uninfected children. Surveillance was conducted for invasive Hib disease in a cohort of 39,865 (approximately 6.4% of whom were HIV infected) children from March 1998 to June 2004. HIV infected children had lower anti-HibPS geometric mean antibody concentrations 1 month post-immunisation than HIV uninfected children (P<0.00001) and were less likely to have anti-HibPS antibody concentrations of >or=1.0 microg/ml (RR 0.54; 95% CI 0.43-0.69). A lower proportion of HIV infected children than HIV uninfected children (RR 0.78; 95% CI 0.66-0.93) had measurable anti-Hib serum bactericidal activity (SBA) and the HibPS antibody concentration required for 50% killing of Hib bacteria was greater among HIV infected than HIV uninfected children (P=0.001). The estimated risk of HibCV failure was 35.1-fold greater (95% CI 14.6-84.6) amongst HIV infected than HIV uninfected children.  相似文献   
15.
16.
17.
Lignans and their in vivo metabolites, especially enterolactone (ENL), have attracted substantial interest as potential chemopreventive agents for prostate cancer. Preclinical and clinical interventions performed with lignan-rich flaxseed that use surrogate biomarkers as endpoints suggest that lignans may attenuate prostate carcinogenesis in individuals with increased risk or with diagnosed cancer. No unequivocal prostate cancer risk reduction has been found for lignans in epidemiological studies, suggesting that lignan concentrations found in populations consuming a regular non-supplemented diet are not chemopreventive in prostate cancer. Presumably, the main obstacles in assessing the efficacy of food lignans is limited knowledge of the serum and tissue lignan concentrations required for the putative prevention. Further clinical studies performed with the purified compounds are required to substantiate a health claim.  相似文献   
18.
Functional characteristics of electrically stimulated quadriceps muscles of patients with multiple sclerosis (MS) were determined to investigate whether adaptations in muscle properties contribute to the higher fatigability of these patients. The estimated maximal isometric force generating capacity of MS patients was only 11.2% (P < 0.05) lower than control subjects. However, the patients were only able to voluntarily exert 75 +/- 22% (n = 12) of their maximal capacity, against 94 +/- 6% (n = 7) for the control subjects. There were no differences in muscle speed, suggesting that muscle fiber distribution was not different in the MS patients due to reduced muscle usage. During a series of repeated contractions, greater decrements occurred in isometric force and in maximal rate of force rise in the MS patients (by 31.3 +/- 10.3% and 50.1 +/- 10.0%, respectively; n = 13) than control subjects (23.8 +/- 6.6% and 39.0 +/- 8.1%, n = 15), suggesting a lower oxidative capacity. The results indicate that increasing the mass of their muscles by training may help to reduce the excessive muscle fatigue of MS patients.  相似文献   
19.
20.
    
Background: Although transarterial chemoembolization(TACE) is the first-line therapy for intermediatestage hepatocellular carcinoma(HCC), it is not suitable for all patients. This study aimed to determine how to select patients who are not suitable for TACE as the first treatment choice. Methods: A total of 243 intermediate-stage HCC patients treated with TACE at three centers were retrospectively enrolled, of which 171 were used for model training and 72 for testing. Radiomics features were scr...  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