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   40785篇
  免费   2066篇
  国内免费   183篇
耳鼻咽喉   519篇
儿科学   801篇
妇产科学   451篇
基础医学   5180篇
口腔科学   1220篇
临床医学   2771篇
内科学   9465篇
皮肤病学   845篇
神经病学   3800篇
特种医学   2059篇
外国民族医学   1篇
外科学   6387篇
综合类   148篇
一般理论   6篇
预防医学   1239篇
眼科学   891篇
药学   2634篇
中国医学   94篇
肿瘤学   4523篇
  2023年   212篇
  2022年   387篇
  2021年   673篇
  2020年   392篇
  2019年   506篇
  2018年   639篇
  2017年   557篇
  2016年   716篇
  2015年   705篇
  2014年   888篇
  2013年   1088篇
  2012年   1819篇
  2011年   1906篇
  2010年   1127篇
  2009年   1006篇
  2008年   1721篇
  2007年   2041篇
  2006年   1846篇
  2005年   1849篇
  2004年   1858篇
  2003年   1812篇
  2002年   1809篇
  2001年   1397篇
  2000年   1481篇
  1999年   1366篇
  1998年   587篇
  1997年   479篇
  1996年   473篇
  1995年   401篇
  1994年   386篇
  1993年   342篇
  1992年   1038篇
  1991年   909篇
  1990年   862篇
  1989年   849篇
  1988年   798篇
  1987年   782篇
  1986年   697篇
  1985年   643篇
  1984年   455篇
  1983年   370篇
  1982年   169篇
  1979年   312篇
  1978年   221篇
  1977年   204篇
  1974年   205篇
  1973年   173篇
  1972年   170篇
  1971年   187篇
  1969年   178篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Lp(a) lipoprotein in cerebrovascular disease and dementia   总被引:1,自引:0,他引:1  
Lp(a) lipoprotein has been considered an independent risk factor in the development of coronary heart disease (CHD). We examined the role of Lp(a) in patients with cerebrovascular disease (CVD) and those with dementia. The Lp(a) concentration in patients with CHD, those with cerebral infarction due to a large artery occlusion and those with vascular dementia (VD) was significantly higher than that of age-matched control subjects. However, the Lp(a) concentration was not high in cerebral infarction due to a small artery occlusion, intracerebral hemorrhage and dementia of the Alzheimer type (DAT). The present results suggest that Lp(a) should cause VD as well as CVD, and that Lp(a) should be one of the indicators that distinguish VD from DAT.  相似文献   
82.
83.
To achieve prolonged breath-holding, oxygen was administered just before dynamic CT and high resolution lung CT. Oxygen administration has proved to be a supportive means to improve the quality of CT studies.  相似文献   
84.
85.
A 57-year-old female presented with an abnormal Pap smear. Colposcopic examination of the cervix revealed white mucosa with erosion and several areas of black pigmentation. After a colposcopically directed biopsy and loop conization, radical hysterectomy and bilateral salpingo-oophorectomy with pelvic and paraaortic lymphadenectomy were performed. Pathological examination disclosed an invasive squamous cell carcinoma admixed with many dendritic melanocytes. Melanin granules were present within the melanocytes and tumor cells. Although similar tumors have been reported in other sites, this is the first report to our knowledge of a pigmented squamous cell carcinoma of the uterine cervix.  相似文献   
86.
We describe a case of a large bronchial fistula and empyema after right upper lobectomy that was treated successfully with open window thoracostomy followed by a latissimus dorsi myocutaneous flap and limited thoracoplasty. A latissimus dorsi myocutaneous flap can provide immediate airtight closure of a large bronchial fistula, allowing lavage and curettage of the empyema cavity to reduce the chance of postoperative infection. An important aspect of this technique is that the deepithelialized skin side rather than muscle is sutured to an opening of the bronchus. As compared with other techniques, a latissimus dorsi myocutaneous flap is superior in that it requires a single incision and does not require an intraop-erative change of position. In addition, the technique causes little dysfunction of the chest and shoulder and preserves the vascular supply to ensure the viability of the flap even if it was divided in a previous operation.  相似文献   
87.
88.
89.
Since the prevalence and clinical characteristics of young-onset hypertension are still to be elucidated, we performed targeted-screening at an annual university health check-up for two consecutive years. Out of 16,464 subjects in 2003 and 17,032 in 2004 that were aged less than 30 years, 22 and 26 students (all males) exhibited high blood pressure (BP), respectively, on three occasions during casual BP measurements at the Tohoku University Health Center (systolic and diastolic BP of 140 and/or 90 mmHg or greater, respectively). These students were asked to measure their BP at home, and 9 subjects in total were diagnosed as having essential hypertension (EH). The remaining students were diagnosed as having white coat hypertension (WCH). In 8 out of 9 EH students, their father and/or mother had also been treated with antihypertensive medication. Adjustment by attendance ratio for each BP measurement suggested that the incidence of EH was around 0.1% and that of hypertension (EH and WCH) was around 0.5% in university students aged less than 25 years, since most of the subjects and hypertensive students were between 18 and 24 years old. Body mass index of the EH, which was more than 25 kg/m2 (overweight), was significantly higher than that with WCH. In conclusion, the combination of repeated casual BP measurements and home BP effectively identified young-onset EH. The clinical parameters indicated that male gender, genetic background, and excessive weight were risk factors for young-onset hypertension.  相似文献   
90.
The p53 gene has been implicated as a tumor suppressor gene involved in the pathogenesis of lung cancer. Our previous study revealed that the p53 gene is frequently mutated with a distinct nucleotide substitution pattern in small cell lung cancer specimens in Japanese patients. In this study, we examined 30 primary, resected non-small cell lung cancer samples in Japanese patients using complementary DNA-polymerase chain reaction and sequencing. Mutations changing the p53 coding sequence were found in 14 of 30 tumor samples (47%), while G:C to T:A transversions which are uncommon in other cancers such as colon cancer were the most frequently observed mutations, in agreement with an earlier report on non-small cell lung cancer in American patients. Furthermore, the present study shows for the first time that in univariate and multivariate analyses, the presence of p53 mutations is closely associated with lifetime cigarette consumption.  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