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   774篇
  免费   49篇
  2023年   6篇
  2022年   6篇
  2021年   12篇
  2020年   12篇
  2019年   15篇
  2018年   23篇
  2017年   17篇
  2016年   33篇
  2015年   40篇
  2014年   45篇
  2013年   59篇
  2012年   88篇
  2011年   69篇
  2010年   49篇
  2009年   39篇
  2008年   38篇
  2007年   37篇
  2006年   36篇
  2005年   34篇
  2004年   50篇
  2003年   34篇
  2002年   29篇
  2001年   7篇
  2000年   3篇
  1999年   5篇
  1998年   1篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1994年   5篇
  1993年   3篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1979年   2篇
  1973年   1篇
排序方式: 共有823条查询结果,搜索用时 15 毫秒
1.

Aims

To assess the association of social determinants on the performance of health systems around the world.

Methods

A transnational ecological study was conducted with an observation level focused on the country. In order to research on the strength of the association between the annual maternal and child mortality in 154 countries and social determinants: corruption, democratization, income inequality and cultural fragmentation, we used a mixed linear regression model for repeated measures with random intercepts and a conglomerate-based geographical analysis, between 2000 and 2010.

Results

Health determinants with a significant association on child mortality(<1year): higher access to water (βa Quartile 4(Q4) vs Quartile 1(Q1) = -6,14; 95%CI: -11,63 to -0,73), sanitation systems, (Q4 vs Q1 = -25,58; 95%CI: -31,91 to -19,25), % measles vaccination coverage (Q4 vs Q1 = -7.35; 95%CI: -10,18 to -4,52), % of births attended by a healthcare professional (Q4 vs Q1 = -7,91; 95%CI: -11,36 to -4,52) and a % of the total health expenditure (Q3 vs Q1 = -2,85; 95%CI: -4,93 to -0,7). Ethnic fragmentation (Q4 vs Q1 = 9,93; 95%CI: -0.03 to 19.89) had a marginal effect. For child mortality<5 years, an association was found for these variables and democratization (not free vs free = 11,23; 95%CI: -0,82 to 23,29), out-of-pocket expenditure (Q1 vs Q4 = 17,71; 95%CI: 5,86 to 29,56). For MMR (Maternal mortality ratio), % of access to water for all the quartiles, % of access to sanitation systems, (Q3 vs Q1 = -171,15; 95%CI: -281,29 to -61), birth attention by a healthcare professional (Q4 vs Q1 = -231,23; 95%CI: -349,32 to -113,15), and having corrupt government (Q3 vs Q1 = 83,05; 95%CI: 33,10 to 133).

Conclusions

Improving access to water and sanitation systems, decreasing corruption in the health sector must become priorities in health systems. The ethno-linguistic cultural fragmentation and the detriment of democracy turn out to be two factors related to health results.  相似文献   
2.
3.
Developmental axon branching dramatically increases synaptic capacity and neuronal surface area. Netrin-1 promotes branching and synaptogenesis, but the mechanism by which Netrin-1 stimulates plasma membrane expansion is unknown. We demonstrate that SNARE-mediated exocytosis is a prerequisite for axon branching and identify the E3 ubiquitin ligase TRIM9 as a critical catalytic link between Netrin-1 and exocytic SNARE machinery in murine cortical neurons. TRIM9 ligase activity promotes SNARE-mediated vesicle fusion and axon branching in a Netrin-dependent manner. We identified a direct interaction between TRIM9 and the Netrin-1 receptor DCC as well as a Netrin-1–sensitive interaction between TRIM9 and the SNARE component SNAP25. The interaction with SNAP25 negatively regulates SNARE-mediated exocytosis and axon branching in the absence of Netrin-1. Deletion of TRIM9 elevated exocytosis in vitro and increased axon branching in vitro and in vivo. Our data provide a novel model for the spatial regulation of axon branching by Netrin-1, in which localized plasma membrane expansion occurs via TRIM9-dependent regulation of SNARE-mediated vesicle fusion.  相似文献   
4.
5.
6.
7.
  1. Torymus sinensis Kamijo was released into Europe to control the Asian chestnut gall wasp Dryocosmus kuriphilus Yasumatsu, proving to be an effective biocontrol agent.
  2. In Japan, hybrids between this exotic parasitoid and the native congeneric Torymus beneficus Yasumatsu and Kamijo have been recorded, whereas no case of hybridization with natives has been reported for Europe.
  3. The seasonal phenology of the Torymus species was investigated in north‐west Italy and 172 997 chestnut galls (Castanea spp.), 7866 oak galls (Quercus spp.), 29 wild rose galls (Rosa spp.) and 44 bramble galls (Rubus spp.) were collected over a 5‐year period.
  4. The seasonal flight activity was recorded for eight native Torymus species [Torymus affinis (Fonscolombe), Torymus auratus (Müller), Torymus bedeguaris (L.), Torymus calcaratus Nees, Torymus cyaneus Walker, Torymus flavipes (Walker), Torymus geranii (Walker) and Torymus notatus (Walker)] and five of them were found to overlap with T. sinensis flight, namely T. affinis, T. auratus, T. flavipes, T. geranii and T. notatus.
  5. Among the Torymus native species, T. notatus revealed to be morphologically and phylogenetically closely related to T. sinensis, thus suggesting hybridization potential.
  相似文献   
8.
9.
10.
The aim of the present study was to evaluate the inhibitory effect of Enterococcus faecium and Lactococcus lactis subsp. lactis isolated from faeces of healthy dogs on (i) lag phase, (ii) growth rate, and (iii) aflatoxin B1 production by Aspergillus section Flavi on in vitro assays. Thirteen lactic acid bacteria (LAB) isolates were used as antagonist microorganisms. Antagonistic activity was assayed against four potentially aflatoxigenic Aspergillus section Flavi isolates: A. flavus (AF210 and AF281), A. parasiticus (AP245) and A. parasiticus (NRRL 2999). In general, the longest lag phases of Aspergillus isolates were obtained with E. faecium GJ40. Respecting the growth rate, no significant reduction was found in this parameter in the interaction assays with A. flavus and antagonist isolates respecting the control. While in A. parasiticus a significant reduction in growth rate was only observed in the interaction among reference strain and E. faecium MF5 isolate (p < 0.05). In general, AFB1 production was reduced by most of the LAB isolates assayed, except for E. faecium GJ18, GJ20, MF3 and MF4. This study provides the first data about the antiaflatoxigenic activity of autochthonous LAB isolated from dog faeces.  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