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   182033篇
  免费   1326篇
  国内免费   20篇
耳鼻咽喉   1256篇
儿科学   6856篇
妇产科学   3075篇
基础医学   17189篇
口腔科学   1626篇
临床医学   12893篇
内科学   32181篇
皮肤病学   790篇
神经病学   16939篇
特种医学   9198篇
外科学   29991篇
综合类   2450篇
一般理论   4篇
预防医学   18325篇
眼科学   3054篇
药学   9978篇
中国医学   650篇
肿瘤学   16924篇
  2023年   67篇
  2022年   176篇
  2021年   326篇
  2020年   162篇
  2019年   259篇
  2018年   22152篇
  2017年   17537篇
  2016年   19729篇
  2015年   1122篇
  2014年   1159篇
  2013年   1167篇
  2012年   7537篇
  2011年   21610篇
  2010年   19107篇
  2009年   11792篇
  2008年   19861篇
  2007年   22093篇
  2006年   901篇
  2005年   2510篇
  2004年   3660篇
  2003年   4653篇
  2002年   2698篇
  2001年   332篇
  2000年   451篇
  1999年   209篇
  1998年   247篇
  1997年   242篇
  1996年   112篇
  1995年   133篇
  1994年   116篇
  1993年   76篇
  1992年   63篇
  1991年   109篇
  1990年   146篇
  1989年   97篇
  1988年   56篇
  1987年   50篇
  1986年   30篇
  1985年   32篇
  1984年   25篇
  1982年   27篇
  1980年   42篇
  1970年   24篇
  1969年   25篇
  1938年   60篇
  1937年   25篇
  1935年   22篇
  1934年   30篇
  1932年   56篇
  1930年   47篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.

Introduction  

This paper presents the results of a study on the psychometric properties of an authorized Spanish version of the McMaster Family Assessment Device, a self-report measure of family functioning.  相似文献   
13.
Ehlers-Danlos syndrome – vascular type, the only lethal form, is rarely reported in dermatology literature. It is characterized by translucent, atrophic skin, easy bruising, arterial, intestinal and/or uterine fragility manifesting as varicose veins, aneurysms and vascular/visceral/uterine rupture. As its dermatopathologic features are not well elucidated, diagnosis is often made after a catastrophic complication or at autopsy. This 36 year-old non-consanguineous male had brown-black plaques with atrophy and frequent ulceration over legs and dorsal feet and tortuous varicose veins around ankles for the past 15 years. Perivenous skin was translucent and hypopigmented. He had multiple and ecchymotic keloids and small atrophic, pityriasis versicolor-like lesions over trunk. He did not have hypermobile/hyperextensible skin and joints and showed no systemic or investigative abnormality. Histopathologic features of atrophic lesion included blood extravasation in atrophic epidermis/dermis, focal clustering and dilatation of blood vessels, malformed vessel walls, abundant hemosiderin in the dermis and homogenously stained/whorled patterned collagen especially around blood vessels. Pathology of keloidal lesion showed new collagen and vascular fragility. These histopathologic features appear of diagnostic value especially in patients who have compatible clinical findings but cannot afford confirmation by biochemical testing for abnormal synthesis of type III procollagen or identification of mutations in the COL3A1 gene.  相似文献   
14.
15.
16.

Introduction  

Although ependymoma is the third most common pediatric brain tumor, we know little about the genetic/epigenetic basis of its initiation, maintenance, or progression. This is due in part to the heterogeneity of the disease, as well as the small sample size of the cohorts analyzed in most studies.  相似文献   
17.
18.
A benign esophageal leiomyoma with abnormally increased fluorine-18-fluorodeoxyglucose uptake on positron emission tomography (PET) was resected thoracoscopically. The tumor, of which the maximum standardized uptake value of the lesion was 4.7, was well defined and 38 mm in diameter. Neither mitotic activity nor degeneration was found histologically; and immunoreactivity for CD34, CD117, MIB-1, and glucose transporter-1 was negative immunohistochemically. A diagnosis of gastrointestinal stromal tumor was ruled out by an oncogenic kinase gene mutation study. This case cautions against PET-dependent evaluation for malignant potential of esophageal submucosal tumors.  相似文献   
19.
20.
Preclinical and clinical investigations currently underway are employing novel strategies for combining vaccines with conventional and experimental anticancer therapies. To date, the FDA has not approved a therapeutic cancer vaccine. However, the results of recent investigations suggest an increasing role for vaccines in new models of combination therapy for many types of cancer. This article reviews and discusses therapeutic cancer strategies that employ vaccines in combination with local radiation, chemotherapy, hormone therapy, and anti-CTLA-4 mAb. Preclinical studies have shown that certain anticancer agents have immune modulatory effects that result in up-regulation of surface expression of MHC molecules, tumor-associated antigens, or Fas on malignant cells, rendering them more susceptible to immune destruction. Preliminary results of clinical studies using combination strategies have demonstrated a postvaccination antigen cascade, prolonged time to disease progression, and improved overall survival. Several larger randomized trials are ongoing, and more are required to support these findings.  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