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   9127篇
  免费   399篇
  国内免费   40篇
耳鼻咽喉   107篇
儿科学   222篇
妇产科学   88篇
基础医学   1126篇
口腔科学   305篇
临床医学   550篇
内科学   2212篇
皮肤病学   147篇
神经病学   663篇
特种医学   459篇
外科学   1704篇
综合类   32篇
预防医学   170篇
眼科学   133篇
药学   480篇
中国医学   17篇
肿瘤学   1151篇
  2023年   39篇
  2022年   79篇
  2021年   122篇
  2020年   65篇
  2019年   108篇
  2018年   164篇
  2017年   157篇
  2016年   183篇
  2015年   170篇
  2014年   254篇
  2013年   309篇
  2012年   505篇
  2011年   590篇
  2010年   339篇
  2009年   356篇
  2008年   549篇
  2007年   599篇
  2006年   611篇
  2005年   603篇
  2004年   636篇
  2003年   594篇
  2002年   576篇
  2001年   80篇
  2000年   85篇
  1999年   133篇
  1998年   166篇
  1997年   153篇
  1996年   153篇
  1995年   113篇
  1994年   119篇
  1993年   121篇
  1992年   62篇
  1991年   64篇
  1990年   60篇
  1989年   53篇
  1988年   47篇
  1987年   44篇
  1986年   46篇
  1985年   36篇
  1984年   47篇
  1983年   46篇
  1982年   43篇
  1981年   42篇
  1980年   32篇
  1979年   19篇
  1978年   29篇
  1977年   17篇
  1976年   16篇
  1974年   17篇
  1973年   15篇
排序方式: 共有9566条查询结果,搜索用时 0 毫秒
41.
The baculovirus expression system was used to produce three different constructs of the murine cell surface adhesion receptor CD2. One construct coded for a single, N-terminal, Ig-fold domain. It was inefficiently secreted and therefore primarily intracellular. The second construct coded for both extracellular, N-terminal Ig-fold domains. This was efficiently secreted into culture supernatant. The third construct coded for the full-length transmembrane molecule which localized to the cell surface. All constructs were monomers of predicted MWr and were appropriately glycosylated. They retained epitopic specificity as demonstrated by binding to mAbs, and adhesion function as demonstrated by a rosetting assay.  相似文献   
42.
43.
Four cases of Ischemic enterocolitis without arterio–occlusive lesion were described. Three cases were associated with sigmoid colon carcinomas. Ischemic lesions developed anal to the carcinomas in two cases, and oral to sigmoidostomy to relieve intestinal obstruction by carcinoma in one case. One other case was associated with inguinal hernia. Grossly, ischemic lesions involved relatively short intestinal segments, and the ischemic colonic lesions were not related to teniae coli. Extensive veno–occlusive lesions were discovered in a case of ischemic stricture of the ileum, which had been incarcerated in the right inguinal hernia. Reversible mechanical occlusion of the intestinal vessels caused by transient or recurrent intestinal strangulation is the most probable cause of these ischemic lesions., ACTA PATHOL. JPN. 33: 249–256, 1983.  相似文献   
44.
Summary We have identified a polymorphic 9-bp repeat sequence in exon 1 of thehMSH3 gene using polymerase chain reaction (PCR). Five alleles were observed in unrelated Japanese individuals with heterozygosity of 0.57.  相似文献   
45.
46.
The increasing complexity of diseases and advancing medical technologies have recently raised the number of test items and their use. This has caused each department to ask for clinical support by medical technologists, including consultation services on clinical laboratory tests in Japan. Under these circumstances, we think it is necessary to consider a Japanese education system for medical technologists to foster people with advanced ability capable in providing adequate clinical support. It is important that we study medical technologist systems and education systems superior to than ours. Therefore, to investigate the state of the Japanese education system for medical technologists, we conducted a comparison between the medical technologist systems and education systems in foreign countries and those of Japan. The social background in which medical technologists are positioned, their scope of work, and the education systems overseas are different from Japan on many points and we were given many suggestions for what a system in Japan should be like.  相似文献   
47.
In order to obtain information about preaneurysmal changes, the junction of the internal carotid artery/posterior communicating artery (ICA/PComA) in the circles of Willis in subjects with aneurysms at sites other than the junction, and in control subjects without aneurysms, were studied by light microscopy.
Small evaginations and thinnings of the media with and without dilatation were observed at the apical areas of the forks with a significantly higher incidence in the aneurysm series than in the control, suggesting some predisposing factor in subjects with aneurysms. As well as funnel-shaped dilatations previously described as the only type of ICA/PComA preaneurysmal change, other more localized types were observed. All the small evaginations and about half of the thinnings and dilatations were observed at the apex in association with a medial gap, but the other half occured at some distance from the apex. The thinned arterial wall showed degenerative changes of the elastic lamina and media. Intimal pads were observed at the apex, the ICA/PComA lateral angle and the ICA stem/branch curve. Their combination with preaneurysmal changes was more frequent in the aneurysm series in comparison with the control.
Degenerative changes of the elastic lamina and media caused by hemodynamic stress due to branching structures including intimal pads are thus presumed to be the initial lesions existing prior to aneurysm formation.  相似文献   
48.
The tissue differentiation of the zona glomerulosa of the fetal adrenal cortex of rats was studied by giving experimental treatments to the fetus in vivo. A low-glucocorticoid-condition was given to the fetus by bilateral adrenalectomy of pregnant rats for removing exogenous glucocorticoids from the fetus, and by brain aspiration of the fetuses for removing the fetal pituitary gland (ACTH) and endogenous glucocorticoids. When the fetus was placed under a low-glucocorticoid-condition for the last couple of days of gestation, poor differentiation of the zona glomerulosa occurred speciflcally in the fetal adrenal cortex. The degree of the poor differentiation seemed to be proportional to the duration of the low-glucocorticoid-condition. Supplemental administration of glucocorticoids could prevent this poor differentiation of the zona glomerulosa. These results indicate that the tissue differentiation of the zona glomerulosa of the fetal adrenal cortex depends much on glucocorticoids.  相似文献   
49.
50.
A case with lymphadenopathy of the left side of the neck in a 38-year-old male is described. He had a history of several relapses of about 10 years duration. Swollen lymph nodes were histologically similar to those of the hyaline-vascular type of Castleman's disease, but contained clear-cut lymph sinus and a sheet-like proliferation of plasma cells. Lymph follicles showed proliferation and atrophic germinal centers, in which cellular hypertrophy in the wall of ramifying small blood vessels, called angiosclerosis, was frequently encountered. During its progress, the patient developed plasmacytoma of the lymph nodes with varied clinical manifestations such as polyneuropathy, disturbance of gait, unusual perspiration, hirsuitism, gynecomastia, bilateral papilledema, and albumino-cytologic dissociation in cerebrospinal fluid.  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