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   258篇
  免费   16篇
  2024年   1篇
  2023年   1篇
  2022年   5篇
  2021年   8篇
  2020年   3篇
  2019年   3篇
  2018年   5篇
  2017年   2篇
  2016年   8篇
  2015年   27篇
  2014年   30篇
  2013年   21篇
  2012年   26篇
  2011年   12篇
  2010年   11篇
  2009年   8篇
  2008年   16篇
  2007年   11篇
  2006年   12篇
  2005年   11篇
  2004年   7篇
  2003年   11篇
  2002年   5篇
  2001年   9篇
  2000年   5篇
  1999年   3篇
  1998年   1篇
  1997年   1篇
  1996年   2篇
  1994年   3篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
  1983年   1篇
  1975年   1篇
  1965年   1篇
排序方式: 共有274条查询结果,搜索用时 31 毫秒
71.
BackgroundConsidering the importance of health literacy (HL) for the maximum yield from the hypertension control programs, development of a reliable and valid instrument of hypertension-related HL is critical. This study aimed to translate and validate the High Blood Pressure-Health Literacy Scale (HBP-HLS) into Chinese (C-HBP-HLS) and evaluate its psychometric properties in Chinese context.MethodBetween June 2013 and January 2014, a cross-sectional study was conducted among recruited hypertensive patients belonging to the Han and Kazakh-Chinese communities in Urumqi, Xinjiang, China.ResultsA pilot sample (n = 242) was selected for the exploratory factor analysis of the translated and modified instrument. Another sample (n = 308) was recruited for the confirmatory factor analysis. C-HBP-HLS consisted of five dimensions (Print Health Literacy, Medication Label, Understanding Ability, Newest Vital Sign Test, and Avoiding Food Allergy) containing 15 items, accounting for 77.7% of the total variance. The 5-factor model demonstrated a good overall fit. The scale-level content validity index was 0.85. Cronbach’s alpha of the overall scale was 0.78 and test-retest reliability was 0.96. Education level had a strong positive correlation with the scores for items Q1, Q2, and Q3(r = 0.481, 0.492, 0.475, respectively). Health Literacy scores among Kazakh patients were significantly lower than Han (7.13±7.90 vs. 30.10±13.42, Z = -14.573, P<0.001).ConclusionC-HBP-HLS demonstrated suitable factor structure and robust psychometric properties for measuring health literacy level among hypertensive patients in China.  相似文献   
72.
In this study the effects of vitamin A on tadpoles of Polypedates maculatus with an amputated tail were investigated. After amputation of half the tail at the hindlimb-bud stage, tadpoles were exposed to vitamin A (palmitate) 10 IU/ml solution for 24 hr (Group I), 48 hr (II), 72 hr (III), 96 hr (IV), 120 hr (V) or 144 hr (VI). Vitamin A was deleterious to survival of the tadpoles since 10, 30 and 30% tadpoles died from Group IV, V and VI, respectively before the emergence of forelimbs. Regeneration of the tail was abnormal in 91.7% of the tadpoles. Vitamin A induced homeotic transformation of the amputated tail to hindlimbs in 11.6% of the animals. Normal limb development was suppressed partially or completely in 48.3% tadpoles. These results indicate that in addition to traumatic effects, vitamin A can lead to homeotic transformation of the tail into hindlimbs and can also interfere with normal development of limbs.  相似文献   
73.
Development of extension in agroforestry draws on the application of the innovation-diffusion process in agriculture. To be effective, agroforestry extension needs to fit the dynamics of the target farming system, the local socioeconomic and technological systems, and land use constraints. Failure of agroforestry extension has been blamed on inadequate and inappropriate methods, but there have been few studies to identify those factors that determine a farmer's awareness of, or attitude to, agroforestry. The present study focused on the modes of communication used in extension and how they affected adoption of agroforestry in a subsistence farming region of eastern India. The decision to adopt agroforestry was found to be determined by the farmers' attitude to agroforestry, which in turn was shaped by information received through farmer-to-farmer and farmer-to-extension contact. The mode of communication was important and, to be effective, needs to be customized for each target group.  相似文献   
74.
The Protein Journal - Using molecular dynamics simulations, the protein–protein interactions of the receptor-binding domain of the wild-type and seven variants of the severe acute respiratory...  相似文献   
75.
Yeast Nhx1 [Na+(K+)/H+ exchanger 1] is an intracellular Na+(K+)/H+ exchanger, localizing to the late endosome where it is important for ion homoeostasis and vesicle trafficking. Phylogenetic analysis of NHE (Na+/H+ exchanger) sequences has identified orthologous proteins, including HsNHE6 (human NHE6), HsNHE7 and HsNHE9 of unknown physiological role. These appear distinct from well-studied mammalian plasma membrane isoforms (NHE1-NHE5). To explore the differences between plasma membrane and intracellular NHEs and understand the link between ion homoeostasis and vesicle trafficking, we examined the consequence of replacing residues in the intramembranous H10 loop of Nhx1 between transmembrane segments 9 and 10. The critical role for the carboxy group of Glu355 in ion transport is consistent with the invariance of this residue in all NHEs. Surprisingly, residues specifically conserved in the intracellular isoforms (such as Phe357 and Tyr361) could not be replaced with closely similar residues (leucine and phenylalanine) found in the plasma membrane isoforms without loss of function, revealing unexpected side chain specificity. The trafficking phenotypes of all Nhx1 mutants, including hygromycin-sensitivity and missorting of carboxypeptidase Y, were found to directly correlate with pH homoeostasis defects and could be proportionately corrected by titration with weak base. The present study demonstrates the importance of the H10 loop of the NHE family, highlights the differences between plasma membrane and intracellular isoforms and shows that trafficking defects are tightly coupled with pH homoeostasis.  相似文献   
76.
Extracellular lipase was produced from Rhizopus oligosporus NRRL 5905 through solid state fermentation (SSF). To provide an optimum fermentation conditions for maximum lipase yield, five process variables (temperature, liquid–solid ratio, pH, incubation period and spore concentration) were optimized using evolutionary operation (EVOP) factorial design technique taking into account the interaction between the process variables. Optimization through EVOP resulted in around 3 fold increase in lipase activity (77 U gds−1) at a liquid–solid ratio of 1.5:1, fermentation temperature of 35°C, initial fermentation pH 6, incubation period 5 days and a spore concentration of 108 spores ml−1.  相似文献   
77.
L-type Ca2+ channels (LTCCs, Cav1) open readily during membrane depolarization and allow Ca2+ to enter the cell. In this way, LTCCs regulate cell excitability and trigger a variety of Ca2+-dependent physiological processes such as: excitation–contraction coupling in muscle cells, gene expression, synaptic plasticity, neuronal differentiation, hormone secretion, and pacemaker activity in heart, neurons, and endocrine cells. Among the two major isoforms of LTCCs expressed in excitable tissues (Cav1.2 and Cav1.3), Cav1.3 appears suitable for supporting a pacemaker current in spontaneously firing cells. It has steep voltage dependence and low threshold of activation and inactivates slowly. Using Cav1.3−/− KO mice and membrane current recording techniques such as the dynamic and the action potential clamp, it has been possible to resolve the time course of Cav1.3 pacemaker currents that regulate the spontaneous firing of dopaminergic neurons and adrenal chromaffin cells. In several cell types, Cav1.3 is selectively coupled to BK channels within membrane nanodomains and controls both the firing frequency and the action potential repolarization phase. Here we review the most critical aspects of Cav1.3 channel gating and its coupling to large conductance BK channels recently discovered in spontaneously firing neurons and neuroendocrine cells with the aim of furnishing a converging view of the role that these two channel types play in the regulation of cell excitability.  相似文献   
78.
79.
With a view to determine ectopic limb developing capacity along with normal hind limb regeneration in response to vitamin A palmitate in well-differentiated hind limb stage tadpoles of P. maculatus, higher doses of vitamin A (30 IU/ml and 20 IU/ml) were administered for a longer period (120 hr) to the tadpoles following tail amputation through middle and hind limb amputation through middle of thigh. Simultaneous development of ectopic pelvic zone was observed along with hind limbs from the cut end of tail and duplication of regenerated hind limbs in the same tadpole for the first time. Besides, development of double ectopic pelvic girdle was also reported in one case. Results also indicate that induction of pelvic zone and duplication of regenerated limbs are concentration dependent.  相似文献   
80.
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