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   1653篇
  免费   92篇
  国内免费   33篇
耳鼻咽喉   27篇
儿科学   74篇
妇产科学   26篇
基础医学   186篇
口腔科学   35篇
临床医学   164篇
内科学   424篇
皮肤病学   123篇
神经病学   69篇
特种医学   224篇
外科学   151篇
综合类   30篇
预防医学   120篇
眼科学   7篇
药学   49篇
中国医学   5篇
肿瘤学   64篇
  2019年   22篇
  2018年   19篇
  2017年   23篇
  2016年   23篇
  2015年   27篇
  2014年   30篇
  2013年   82篇
  2012年   30篇
  2011年   33篇
  2010年   61篇
  2009年   66篇
  2008年   46篇
  2007年   51篇
  2006年   42篇
  2005年   58篇
  2004年   36篇
  2003年   29篇
  2002年   33篇
  2001年   33篇
  2000年   21篇
  1999年   33篇
  1998年   86篇
  1997年   76篇
  1996年   81篇
  1995年   56篇
  1994年   63篇
  1993年   55篇
  1992年   21篇
  1991年   17篇
  1990年   27篇
  1989年   44篇
  1988年   44篇
  1987年   37篇
  1986年   28篇
  1985年   28篇
  1984年   25篇
  1983年   14篇
  1982年   22篇
  1981年   18篇
  1980年   14篇
  1979年   18篇
  1978年   15篇
  1977年   17篇
  1976年   18篇
  1975年   13篇
  1973年   15篇
  1972年   11篇
  1971年   8篇
  1970年   10篇
  1969年   9篇
排序方式: 共有1778条查询结果,搜索用时 15 毫秒
31.
BACKGROUND: Lentigo maligna melanoma is a specific histoclinical type of melanoma. We studied the epidemiologic features of lentigo maligna melanoma (Dubreuilh's melanoma) and compared prognosis with other types of melanoma. PATIENTS AND METHODS: A retrospective review of 516 cases of cutaneous melanomas, seen from 1985 to 1997, identified 29 cases of lentigo maligna melanoma. Epidemiologic, clinical and prognostic data were collected using a common scoring system for all patients. The chi-squared test, univariate log rank analysis, Cox multiple regression model for multivariate analysis, and actuarial survival curves were applied. RESULTS: The 29 cases of lentigo maligna melanoma (16 women, 13 men) accounted for 5.9 p. 100 of all melanomas. Mean age at diagnosis was 73 years compared with 54 years for others melanomas. Predominant localization was head and neck. There was no prior history of nevi compared with 50 p. 100. Mean delay to diagnosis was 4 years versus 1 year. All patients have had an occupation with to sun exposure. Mean tumoral thickness was 2 mm. Survival was the same as for extensive superficial melanomas and better than for nodular melanomas. Multivariate analysis showed that prognosis was not better in case of lentigo maligna melanoma. Tumoral thickness was the main prognosis factor. DISCUSSION: Our findings confirmed the specific nature of lentigo maligna melanoma and suggested that sun exposure plays an important role. Multivariate analysis did not show that prognosis was any better in case of lentigo maligna melanoma than in other types of melanoma. The thickness of the tumor must be taken into account as for other melanomas.  相似文献   
32.
33.
OBJECTIVE: We evaluated the effects of targeted, moderate endurance training on healthcare cost, body composition and fitness in type 2 diabetes patients routinely followed within the French healthcare system. DESIGN AND METHODS: A total of 25 type 2 diabetic patients was randomly assigned to one of two groups: 13 underwent a training programme (eight sessions, followed by training twice a week for 30-45 minutes at home at the level of the ventilatory threshold [V(T)]); and 12 received their usual routine treatment. Both groups were followed for one year to evaluate healthcare costs, exercise effectiveness and a six-minute walking test. RESULTS: The training prevented loss of maximum aerobic capacity, which decreased slightly in the untrained group (P=0.014), and resulted in a higher maximum power output (P=0.041) and six-minute walking distance (P=0.020). The Voorrips activity score correlated with both V(O2max) (r=0.422, P<0.05) and six-minute walking distance (r=0.446, P<0.05). Changes in V(O2max) were negatively correlated with changes in body weight (r=0.608, P<0.01). Training decreased the insulin-resistance index (HOMA-IR) by 26% (P<0.05). Changes in percentages of fat were correlated to changes in waist circumference (r=0.436, P<0.05). The total healthcare cost was reduced by 50% in the trained group (euro 1.65+/-1 per day versus euro 3.00+/-1.47 per day in the untrained group; P<0.02) due to fewer hospitalizations (P=0.05) and less use of sulphonylureas (P<0.05). CONCLUSION: Endurance training at V(T) level prevented the decline in aerobic working capacity seen in untrained diabetics over the study period, and resulted in a marked reduction in healthcare costs due to less treatments and fewer hospitalizations.  相似文献   
34.
35.
Summary We have presented an unusual case of benign lymphoid hyperplasia, which manifested as a cecal deformity in a 15-year-old boy. The clinical manifestation may have been related to partial occlusion of the appendiceal orifice. In future cases of benign lymphoid hyperplasia, colonoscopy may be diagnostic, and if it is used for continuing observation, may avert unnecessary surgical procedures in children and young adults.  相似文献   
36.
37.
38.
The factors predicting smoking abstinence in depressive smokers, and the role of physical activity in precessation, were investigated. One hundred thirty-three smokers with current major depressive disorders (score ≥10 on the Depression subscale of Hospital Anxiety and Depression Scale) were recruited from a large prospective cohort of smokers (n = 1,119). Over a maximum period of 3 years, regression modeling, adjusted for potential confounders, showed that physical activity was associated with relapse (relapse rate = 0.54, 95% confidence interval = 0.34-0.85, p = .008). Also, antidepressants, anxiolytics, level of education, and number of attempts to quit were associated with relapse. The protective role of physical activity on relapse rate could be a modifiable factor in smoking cessation for smokers with depressive disorders.  相似文献   
39.
The epidemiological status of HCV in Europe, and in particular in Mediterranean countries, is continuously evolving. The genotype distribution is related to improvement of healthcare conditions, expansion of intravenous drug use and immigration. We review and characterize the epidemiology of the distribution of HCV genotypes within Calabria, an area of Southern Italy. We focus on the pattern of distinct HCV genotype changes over the last 16 years; particularly subtype 1b and genotype 4. We collected data by evaluating a hospital-based cohort of chronic hepatitis C patients; in addition, we report an update including new patients enrolled during last eight months.  相似文献   
40.
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