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   346篇
  免费   13篇
  国内免费   1篇
儿科学   8篇
妇产科学   3篇
基础医学   23篇
临床医学   32篇
内科学   77篇
皮肤病学   2篇
神经病学   26篇
特种医学   27篇
外科学   76篇
预防医学   28篇
药学   14篇
肿瘤学   44篇
  2022年   4篇
  2019年   5篇
  2018年   8篇
  2017年   2篇
  2016年   2篇
  2015年   4篇
  2014年   6篇
  2013年   8篇
  2012年   7篇
  2011年   8篇
  2010年   12篇
  2009年   12篇
  2008年   21篇
  2007年   19篇
  2006年   22篇
  2005年   15篇
  2004年   19篇
  2003年   16篇
  2002年   14篇
  2001年   17篇
  2000年   15篇
  1999年   15篇
  1997年   2篇
  1996年   4篇
  1995年   4篇
  1994年   2篇
  1992年   6篇
  1991年   5篇
  1990年   4篇
  1989年   9篇
  1988年   9篇
  1987年   7篇
  1986年   11篇
  1985年   8篇
  1984年   3篇
  1983年   3篇
  1982年   1篇
  1980年   1篇
  1979年   6篇
  1978年   1篇
  1977年   2篇
  1975年   2篇
  1974年   3篇
  1973年   2篇
  1972年   1篇
  1971年   2篇
  1969年   2篇
  1967年   2篇
  1966年   2篇
  1965年   1篇
排序方式: 共有360条查询结果,搜索用时 0 毫秒
51.
52.
53.
Abstract: Cerebrospinal fluid (CSF) HVA, MHPG, 5-HIAA, cAMP and cGMP concentrations were measured in schizophrenic patients with tardive dyskinesia before and after a three-week administration of oxypertine (n = 4), hydroxyzine pamoate (n = 4) or placebo (n = 4). The oxypertine administration resulted in a reduction of the CSF HVA concentration and an elevation of the MHPG and cAMP concentrations, associated with a clinical improvement in tardive dyskinesia. The hydroxyzine administration reduced the CSF 5-HIAA concentration in all the patients and the CSF HVA concentration in two of four patients with a clinical improvement. A reduction in the CSF HVA concentration associated with possible therapeutic effects of oxypertine or hydroxyzine may suggest the normalization of a hyperdopaminergic state. Discussions were held that functional disorders of not only the dopaminergic system but the norepinephrinergic and serotoninergic systems may relate to the pathogenesis of tardive dyskinesia.  相似文献   
54.
Abstract: Zotepine (ZTP), synthesized by Fujisawa Pharmaceutical Co., Ltd. for possible use as an antipsychotic drug, clinically features a very rapid and potent antimanic effect. To elucidate the psychopharmacological mechanisms of zotepine, we have attempted to measure the potency of ZTP compared with other neuroleptic drugs in competing for binding sites in the brain associated with dopamine, serotonin (5–HT1, 5–HT2), noradrenaline (NA) and acetyl-choline. Zotepine was found to have the most potent activity to the 5HT1 receptor among the test drugs. Chlorpromazine and thioridazine, which belong to phenothiazines and clinically have less potent antimanic effect, shared ZTP's potent activity to the NA receptor, while they were less potent than ZTP in activity to the 5HT1 receptor. These results show that the activity of the drugs to the 5HT1 receptor may be associated with the antimanic effect.  相似文献   
55.
BACKGROUND/AIMS: Ultrasound is noninvasive and useful to evaluate liver disease despite its operator dependency. This pilot study was conducted to quantitatively assess liver fibrosis using ultrasound. METHODS: Fibrosis extraction ratios (FER) (fiber volume/total volume) of ultrasound and histological images of 8 autopsy specimens were compared. We also compared FER of ultrasound images from clinical patients (n=79) with histological fibrosis stages. RESULTS: In the autopsy study, FER correlation coefficient between histological images and ultrasound images was 0.992. Regarding clinical patients, there was sufficient evidence to indicate differences in the distributions of FER for each fibrosis stage (Kruskal-Wallis test P<0.0001). With FER cut-off to distinguish > or =F2 from F0 and F1 defined as mean plus standard deviation of F0 and F1, sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratio were 62, 75, 78, 57%, and 2.47, respectively. Regarding HCV cohort (n=44), they were 55, 87, 89, 50%, and 4.14, respectively. Areas under receiver operating characteristic curves were 0.78, 0.79, 0.83 and 0.83 for > or =F1, > or =F2, > or =F3 and =F4, respectively. Regarding HCV cohort, they were 0.74, 0.71, 0.79 for > or =F2, > or =3 and =4, respectively. CONCLUSIONS: The FER method has great potential for diagnosing liver fibrosis using ultrasound.  相似文献   
56.
We have identified the murine Clast1/LR8 gene by subtraction of cDNA derived from CD40 ligand-activated and naive B cells. The Clast1 gene is ubiquitously expressed in various organs of adult mice. However, its physiological function was largely unknown. To study a role of Clast1, we established Clast1-deficient (Clast1-KO) mice. Here, we reveal that approximately 65% of Clast1-KO mice showed severe ataxia. The Clast1-KO cerebellum with ataxia is small in size and revealed a severely aberrant lobulation, loss of the internal granule cell layer, and the disorganized Purkinje cells. Clast1 mRNA is expressed in the cerebellar granule cells of normal adult mice. Developmentally, Clast1 mRNA is also detected in the external germinal layer of the embryonic cerebellum, indicating its expression in granule cell precursors. Histopathological analysis of the developing Clast1-KO cerebellum demonstrated the reduced number of cells in the external germinal layer. Thus, Clast1 is required for development of cerebellar granule cells.  相似文献   
57.

Objectives  

Indoor air pollutants from biomass combustion pose a risk for respiratory diseases in children. It is plausible that distinct differences in the indoor air quality (IAQ) exist between urban and rural areas in developing countries since the living environment between these two areas are quite different. We have investigated possible differences in IAQ in urban and rural Dhaka, Bangladesh and the association of such differences with the incidence of respiratory and some non-respiratory symptoms in children of families using biomass fuel.  相似文献   
58.
Enhanced color flow images in small hepatocellular carcinoma   总被引:10,自引:0,他引:10  
BACKGROUND: Features of enhanced color flow images in small hepatocellular carcinoma (HCC) are not fully elucidated. The purpose of this study was to clarify the characteristic vascular images in small HCC observed by enhanced color Doppler. METHODS: Enhanced color Doppler using the contrast agent Levovist was performed on 13 patients with HCC smaller than 30 mm. Enhanced color flow appearance was compared with angiographic findings. Time-intensity changes after injection of the contrast agent were analyzed in HCC nodules. RESULTS: Significant improvement in the detection of color flow signals was obtained in small HCC using Levovist, from 33% in precontrast to 92% in postcontrast (p < 0.005). Three patterns of enhanced color flow images, which were related to the angiographic findings, were observed. The time-intensity curve was classified into two types by "time to peak" and "time on plateau" and was associated with the patterns of enhanced images. CONCLUSION: Enhanced color flow imaging promises to be a useful method for evaluating tumor vascularity noninvasively and to contribute to the elucidation of the hemodynamics in small HCC.  相似文献   
59.
60.
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