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   2588039篇
  免费   185101篇
  国内免费   7572篇
耳鼻咽喉   34294篇
儿科学   85215篇
妇产科学   71577篇
基础医学   363640篇
口腔科学   69669篇
临床医学   234575篇
内科学   515789篇
皮肤病学   62459篇
神经病学   213489篇
特种医学   99905篇
外国民族医学   736篇
外科学   386500篇
综合类   50396篇
现状与发展   5篇
一般理论   968篇
预防医学   196175篇
眼科学   56675篇
药学   188023篇
  8篇
中国医学   5334篇
肿瘤学   145280篇
  2021年   19998篇
  2019年   20630篇
  2018年   29302篇
  2017年   22607篇
  2016年   26243篇
  2015年   29512篇
  2014年   40456篇
  2013年   60443篇
  2012年   80253篇
  2011年   84525篇
  2010年   51019篇
  2009年   49164篇
  2008年   79055篇
  2007年   83875篇
  2006年   85594篇
  2005年   81769篇
  2004年   78753篇
  2003年   76068篇
  2002年   73373篇
  2001年   128422篇
  2000年   131352篇
  1999年   110538篇
  1998年   31260篇
  1997年   27926篇
  1996年   28222篇
  1995年   27386篇
  1994年   25072篇
  1993年   23423篇
  1992年   85166篇
  1991年   81573篇
  1990年   78787篇
  1989年   76069篇
  1988年   69474篇
  1987年   68005篇
  1986年   63549篇
  1985年   60525篇
  1984年   44948篇
  1983年   37950篇
  1982年   22457篇
  1981年   19984篇
  1979年   38967篇
  1978年   27444篇
  1977年   23255篇
  1976年   21500篇
  1975年   22817篇
  1974年   26793篇
  1973年   25376篇
  1972年   23757篇
  1971年   21959篇
  1970年   20190篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
BACKGROUND: Many mild-to-moderately obese individuals (body mass index [BMI] 30-35 kg/m(2)) have serious diseases related to their obesity. Nonoperative therapy is ineffective in the long term, yet surgery has never been made widely available to this population. METHODS: Between 1996 and 2004, 93 patients with a BMI of 30-35 kg/m(2) underwent laparoscopic adjustable gastric banding with the LAP-BAND. All patients were referred by their primary physician, entered into a comprehensive bariatric surgery program at one Australian center, and operated on by one surgeon. Data on all patients were collected prospectively and entered into an electronic registry. The study parameters included preoperative age, gender, BMI, presence of co-morbidities, percentage of excess weight loss, and resolution of co-morbidities. RESULTS: The mean age was 44.6 years (range 16-76), mean weight was 98 kg, and the mean BMI was 32.7 kg/m(2) (range 30-34). Of the 93 patients, 42 (45%) had co-morbidities, including asthma, diabetes, hypertension, and sleep apnea. The proportion of patients in follow-up was 79%, 85%, and 89% at 1, 2, and 3 years, respectively. The mean weight was reduced to 71 kg at 1 year, 72 kg at 2 years, and 72 kg at 3 years. The mean BMI was reduced to 27.2 +/- 2.2, 27.3 +/- 3.1, and 27.6 +/- 3.7 kg/m(2), respectively, and the mean percentage of excess weight loss was 57.9% +/- 24.5%, 57.6 +/- 29.3%, and 53.8% +/- 32.8% at 1, 2, and 3 years, respectively. At 3 years, the BMI was 18-24 kg/m(2) in 34%, 25-29 kg/m(2) in 51%, and 30-35 kg/m(2) in 10%. At 3 years, the percentage of excess weight loss was <25% in 10%, 25-50% in 24%, 50-75% in 51%, and >75% in 10%. The co-morbidities improved or completely resolved in most patients. No mortality occurred. CONCLUSION: We are very encouraged by this series of low BMI patients treated with the LAP-BAND. Their weight loss has been good, the complications have been minimal, and the co-morbidities have partially or wholly resolved. With additional study, it is reasonable to expect the weight guidelines for bariatric surgery to be altered to include patients with a BMI of 30-35 kg/m(2).  相似文献   
82.
Choledochojejunostomy (CJS) is commonly used for biliary reconstruction in liver transplantation for primary sclerosing cholangitis (PSC). We alternatively performed choledochoduodenostomy (CDS) and side-to-side choledochodocholedochstomy in a large cohort of patients. Fifty-one patients with PSC, transplanted between 1988 and 2000, were analyzed retrospectively. Biliary reconstruction was CDS in 25 (49%), CJS in 20 (39%) and CC in 6 transplantations (12%). Biliary leaks occurred in the early follow-up (< or =41 days) only in CDS patients (20%). However, in the late follow-up (>4 months), stricturing of anastomosis was found once in CDS (4%) and CJS (5%). Later (>9 months), intrahepatic bile duct strictures were diagnosed in four CDS (16%), one CJS (5%) and one CC (17%) patient(s). In 48% of CDS (12/25), 60% of CJS (12/20) and 17% of CC (1/6) at least one incidence of cholangitis was observed. Overall, biliary complication rates were significantly higher in CDS (40%) than CJS (10%) and CC (17%); of those none in CC and 12% in CDS were anastomosis-related. Graft/patient survival showed no significant differences among groups. Based on our results we consider CJS the standard method for biliary reconstruction in PSC; however, in selected cases where CJS is difficult to accomplish because of previous surgery or for retransplantation, CDS may present an alternative technique.  相似文献   
83.
84.
85.
86.
87.
BACKGROUND: Previous research has demonstrated that academic and neuropsychological functions are compromised in pediatric bipolar disorder (PBD). Investigation of the degree to which neuropsychological deficits might contribute to those academic problems is needed to aid in the recognition and intervention for school achievement difficulties in PBD. METHODS: A sample of 55 children and adolescents with PBD with and without attention-deficit/hyperactivity disorder (ADHD) (PBD group, n = 28; PBD+ADHD group, n = 27) were tested with a computerized neurocognitive battery and standardized neuropsychological tests. Age range of subjects was 7-17 years, with the mean age of 11.97 (3.18) years. Parents completed a structured questionnaire on school and academic functioning. RESULTS: Logistic regression analyses indicated that executive function, attention, working memory, and verbal memory scores were poorer in those with a history of reading/writing difficulties. A separate logistic regression analysis found that attentional dysfunction predicted math difficulties. These relationships between neuropsychological function and academic difficulties were not different in those with PBD+ADHD than in those with PBD alone. CONCLUSIONS: In PBD neuropsychological deficits in the areas of attention, working memory, and organization/problem solving skills all contribute to academic difficulties. Early identification and intervention for these difficulties might help prevent lower academic achievement in PBD.  相似文献   
88.
89.
Imaging     
  相似文献   
90.
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