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   720篇
  免费   32篇
耳鼻咽喉   1篇
儿科学   32篇
妇产科学   39篇
基础医学   68篇
口腔科学   1篇
临床医学   76篇
内科学   163篇
皮肤病学   191篇
神经病学   21篇
特种医学   11篇
外科学   60篇
综合类   4篇
一般理论   1篇
预防医学   37篇
眼科学   4篇
药学   30篇
肿瘤学   13篇
  2023年   3篇
  2022年   2篇
  2021年   19篇
  2020年   8篇
  2019年   30篇
  2018年   22篇
  2017年   16篇
  2016年   12篇
  2015年   12篇
  2014年   19篇
  2013年   31篇
  2012年   36篇
  2011年   70篇
  2010年   31篇
  2009年   36篇
  2008年   43篇
  2007年   38篇
  2006年   42篇
  2005年   44篇
  2004年   21篇
  2003年   23篇
  2002年   21篇
  2001年   12篇
  2000年   20篇
  1999年   11篇
  1998年   6篇
  1997年   3篇
  1996年   4篇
  1994年   11篇
  1993年   4篇
  1992年   15篇
  1991年   15篇
  1990年   9篇
  1989年   8篇
  1988年   8篇
  1987年   5篇
  1986年   11篇
  1985年   9篇
  1984年   2篇
  1983年   5篇
  1982年   2篇
  1981年   2篇
  1980年   4篇
  1979年   1篇
  1977年   1篇
  1971年   1篇
  1966年   1篇
  1960年   1篇
  1942年   1篇
  1929年   1篇
排序方式: 共有752条查询结果,搜索用时 15 毫秒
1.
Evolution of the newborn infant weighing 1,000-1,499 g, was studied in 1986 in the "Mariana Grajales" Gynecologic and Obstetric Teaching Provincial Hospital, Department of Neonatology, Santa Clara. Data was obtained from the clinical histories of the newborns and of their mothers. A control group was selected in order to analyze and compare the causes of low birthweight, and as causes of it were determined age and height, and as associated diseases, urinary sepsis, anemia and toxemia of pregnancy. Premature rupture of membranes was significant. Half of the infants of the group under study was severe and moderately depressed. At the somatic evolution was observed a trend to increment and a high coefficient of correlation within the three variables under study. Main nursing actions offered fit up to the attention of these neonates.  相似文献   
2.
The effects of substantia nigra (SN) (pars compacta) stimulation on the quiet biting attack evoked by hypothalamic activation in the cat were studied. The measure of the aggressive behavior was the latency of the biting which did not greatly change from one animal to another when hypothalamic stimulation was performed with the same parameters. Concurrent activation of the SN determined an inhibitory effect on the studied behavior in the form of an increase in the biting latency or loss of the attack pattern. The inhibitory role of the SN on predatory attack behavior is discussed.  相似文献   
3.
Women with breast cancer have an increased risk of developing primary ovarian tumors. Because a differential diagnosis between primary and metastatic tumors may be difficult in poorly differentiated ovarian neoplasms, breast carcinoma markers may be helpful in establishing the primary site of origin. Gross cystic disease fluid protein-15 (GCDFP-15), a well-known marker of apocrine differentiation, has been reported as a highly specific and sensitive breast carcinoma marker. To evaluate the usefulness of GCDFP-15 as a marker for metastatic breast cancer, we have studied, by the avidin-biotin-peroxidase technique, 14 cases of breast cancer metastatic to the ovary and compared them with 32 primary ovarian tumors and seven cases of ovarian metastases other than breast in origin. Two cases of primary ovarian cancer metastatic to the breast were also included. A strong cytoplasmic immunostaining was found in 10 of 14 cases (71%) of ovarian metastasis from breast carcinoma, and in most cases a characteristic paranuclear staining was noted. All primary ovarian tumors were negative. Ovarian metastases from tumors other than breast and both cases of ovarian carcinoma metastatic to the breast were negative. These results are highly significant (P less than .00001) and demonstrate the value of GCDFP-15 in establishing a primary breast origin among neoplasms of unknown origin involving the ovaries.  相似文献   
4.
The characteristics of trabecular bone in human fetuses at seven to nine months of intra-uterine life were studied in the vestibular surface of the mental and body portions of the mandible. In the mental portion, many circular trabeculae joined by "bridges" were observed in the alveolar region (AR). In the 8-month old fetus are trabeculae with tortuous disposition in the medium region (MR). Oblique trabeculae with superior and inferior dispositions defining a triangular area (future mental fossae) are verified in 9-month old fetuses. Trabeculae circularly disposed and vascular foramina are present close to the apex of this area. In the basilar region (BR) some trabeculae obliquely oriented are observed disposed near to the mandibular symphysis. The longitudinal bundles of collagen fibers assume an antero-posterior direction. At 9-month age the vascular foramina range from 6 to 20 microns and the osteocyte lacunae ranging from 1 to 4 microns diameter, are present in mandibles from all ages examined. In the body portion the presence of circular trabeculae joined by "bridges" is the main characteristic of the AR. In the MR most of the trabeculae are circular and the longitudinal trabeculae of this region assume an antero-posterior direction. The laminar, antero-posterior and juxtaposed trabeculae lying parallel to mandible base are a characteristic of the BR. The bundles of collagen fibers exhibit the same pattern of the trabeculae. The vascular foramina of the BR are smaller than that of the precedent regions. In the body portion of the mandible from all ages examined the osteocyte lacunae range from 1 to 4 microns in diameter.  相似文献   
5.
Background: The morphogenetic conversion between yeast and hyphal growth forms appears to be crucial in the pathogenesis of invasive candidiasis, and can be regulated by environmental signals such as extracellular pH.  相似文献   
6.
The effects of substantia nigra (SN) (pars compacta) stimulation on the rage reaction elicited by ventromedial hypothalamic nucleus (VMH) were investigated in the cat. The studied parameters of the rage reaction were: the current and the frequency threshold for the appearance of the hissing and the hissing latency. A facilitatory effect induced by the SN on the hypothalamic rage reaction was observed in the form of a decrease in the hypothalamic stimulus threshold for the hissing appearance and a decrease in the hissing latency. Moreover, when the VMH was stimulated with parameters below the threshold for the hissing display, simultaneous nigral activation determined its appearance. The excitatory influence exerted by the SN on the affective component of the aggressive behavior is discussed.  相似文献   
7.
Abdominal scintigraphy shows silent gut inflammation in patients with spondyloarthropathies (Sp) without clinical evidence of gut inflammation. Abdominal scintigraphy images are different than those obtained in patients with ulcerative colitis or Crohn's disease and are not related to the anti-inflammatory drugs administered. The aim of this study was to examine the clinical associations of findings on abdominal scintigraphy in patients with Sp. A total of 204 Sp patients (European Spondylarthropathy Study Group 1991 criteria) and 54 non-Sp controls receiving non-steroidal anti-inflammatory drugs were studied. Abdominal scintigraphy images were obtained at 30 and 120 min after injection of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled leucocytes. 99mTc-HMPAO-labelled leucocyte scans were positive in 104 Sp patients (50.9%) and in six non-Sp controls (2.9%) (P<0.001; OR=8.32; 95% CI=3.23-22.67). Silent gut inflammation was not associated with any of the following: age of onset, duration of evolution, sex, family history of Sp or psoriasis, articular manifestations, extra-articular manifestations, radiological findings or HLA-B27 positivity. Positive abdominal scintigraphy was associated with active disease (P<0.0001; OR=52.7; 95% CI=19-145.6) and an increase in the C-reactive protein (P<0.005; OR=3.4; 95% CI=1.5-7.4). It is concluded that (a) abdominal scintigraphy using 99mTc-HMPAO-labelled leucocytes is of value in detecting the silent gut inflammation in Sp patients, and (b) silent gut inflammation is related to the clinical activity, but is not associated with any particular type of illness or with HLA-B27.  相似文献   
8.
9.
10.
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