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   414篇
  免费   18篇
  国内免费   2篇
耳鼻咽喉   29篇
儿科学   14篇
基础医学   56篇
口腔科学   43篇
临床医学   24篇
内科学   52篇
皮肤病学   24篇
神经病学   22篇
特种医学   12篇
外科学   51篇
综合类   3篇
预防医学   29篇
眼科学   15篇
药学   34篇
中国医学   2篇
肿瘤学   24篇
  2022年   6篇
  2021年   17篇
  2020年   11篇
  2019年   14篇
  2018年   16篇
  2017年   10篇
  2016年   8篇
  2015年   14篇
  2014年   17篇
  2013年   17篇
  2012年   34篇
  2011年   24篇
  2010年   16篇
  2009年   15篇
  2008年   29篇
  2007年   23篇
  2006年   19篇
  2005年   14篇
  2004年   10篇
  2003年   18篇
  2002年   17篇
  2001年   4篇
  2000年   3篇
  1999年   2篇
  1998年   8篇
  1997年   5篇
  1996年   4篇
  1995年   6篇
  1994年   5篇
  1992年   2篇
  1991年   3篇
  1989年   3篇
  1988年   3篇
  1987年   2篇
  1984年   1篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1974年   2篇
  1973年   1篇
  1963年   1篇
  1961年   1篇
  1959年   2篇
  1958年   3篇
  1957年   4篇
  1956年   8篇
  1955年   1篇
  1954年   1篇
排序方式: 共有434条查询结果,搜索用时 171 毫秒
51.
52.
53.
Few studies have focused on Rift Valley fever virus (RVFV) transmission in less arid, transitional landscapes surrounding known high-risk regions. The objective of this study was to identify evidence of RVFV exposure in Bodhei Village in a forested area at the edge of the RVFV-epidemic Garissa region. In a household cluster-based survey conducted between epidemics in early 2006, 211 participants were enrolled. Overall seroprevalence for anti-RVFV was high (18%) and comparable with rates in the more arid, dense brush regions farther north. Seroprevalence of adults was 28%, whereas that of children was significantly lower (3%; P < 0.001); the youngest positive child was age 3 years. Males were more likely to be seropositive than females (25% versus 11%; P < 0.01), and animal husbandry activities (birthing, sheltering, and butchering) were strongly associated with seropositivity. The results confirm that significant RVFV transmission occurs outside of recognized high-risk areas and independent of known epidemic periods.  相似文献   
54.
Infection by the intestinal nematode parasite Nematospiroides dubius was studied in seven different inbred mouse strains. Although there was some minor variation in the susceptibility of the different strains to a primary infection there were marked differences in their ability to develop resistance to infection following repeated exposure to infective larvae. The strains of mice which developed the best resistance also expelled adult worms arising from the previous infections. The adult worms resulting from a primary infection were slowly eliminated in two inbred strains studied whereas no loss occurred from outbred LACA mice. Although males and females of two strains, C3H/HeJ and CBA/H were equally susceptible to a primary infection, the females developed better resistance than the male mice following two oral administrations of third stage larvae. Infected mice of every strain and both sexes contained high levels of IgG1 in the serum.  相似文献   
55.
56.
57.
Our aim was to compare bone gene expression in rheumatoid arthritis (RA) and primary osteoporosis (OP) patients. Secondary aims were to determine the association of gene expression of the Wnt/β-catenin signaling pathway with inflammatory cytokines in the bone microenvironment and to assess the serum levels of Wnt/β-catenin proteins in both groups. RA patients referred for hip replacement surgery were recruited. Primary OP patients were used as controls. Gene expression of Wnt pathway mediators, matrix proteins, and pro-inflammatory cytokines were analyzed in bone samples. Bone turnover markers, inflammatory cytokines, and Wnt mediators were measured in serum. Twenty-two patients were included: 10 with RA and 12 with primary OP. The expressions of Wnt10b (p?=?0.034), its co-receptor LRP6 (p?=?0.041), and its negative regulator DKK1 (p?=?0.008) were upregulated in RA bone. IL17 gene expression in bone was upregulated in RA patients (p?=?0.031) and correlated positively with Wnt10b (r?=?0.810, p?=?0.015), DKK2 (r?=?0.800, p?=?0.010), and RANKL/OPG ratio (r?=?0.762, p?=?0.028). DKK2 (p?=?0.04) was significantly decreased in RA serum compared with primary OP. In conclusion, bone fragility in RA patients is induced by an unbalanced bone microenvironment and is associated with a specific gene expression pattern, namely, the upregulation of IL17 and DKK1, suggesting that the modulation of these two pathways might prevent RA systemic bone loss.  相似文献   
58.
59.
Gallium nitrate, a drug with antitumor activity, is presently undergoing clinical trials as a chemotherapeutic agent for the treatment of certain malignancies. Since there are very limited published animal toxicity data available, this study was conducted to investigate the potential adverse developmental effects of this drug. Pregnant Swiss mice were administered intraperitoneally gallium nitrate at 12.5, 25, 50, and 100 mg/kg/day on days 6, 8, 10, 12, and 14 of gestation. Monitors for maternal toxicity were body weight, food consumption and clinical signs. At sacrifice (day 18) maternal weight, liver and kidney weights, and gravid uterine weights were measured. Gestational parameters monitored were numbers of total implants, resorptions, postimplantation losses, and dead fetuses. Live fetuses were sexed, weighed, and examined for external, internal and skeletal malformations and variations. Maternal toxicity was noted in all the gallium nitrate-treated groups. Embryo/fetal toxicity was evidenced by a decrease in the number of viable implants, a reduction in fetal weight, and an increase in the number of skeletal variations (12.5, 25, 50 and 100 mg/kg). No significant increase in the incidence of malformations was observed at 12.5, 25, or 50 mg/kg. The no-observable-adverse-effect level (NOAEL) for both maternal and developmental toxicity of gallium nitrate was <12.5 mg/kg.  相似文献   
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