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   2356篇
  免费   229篇
  国内免费   2篇
  2587篇
  2024年   4篇
  2023年   36篇
  2022年   98篇
  2021年   156篇
  2020年   66篇
  2019年   81篇
  2018年   79篇
  2017年   66篇
  2016年   112篇
  2015年   174篇
  2014年   156篇
  2013年   168篇
  2012年   208篇
  2011年   176篇
  2010年   103篇
  2009年   103篇
  2008年   131篇
  2007年   93篇
  2006年   98篇
  2005年   73篇
  2004年   57篇
  2003年   49篇
  2002年   58篇
  2001年   15篇
  2000年   12篇
  1999年   7篇
  1998年   14篇
  1997年   7篇
  1996年   10篇
  1995年   7篇
  1994年   11篇
  1993年   6篇
  1992年   5篇
  1991年   5篇
  1989年   4篇
  1988年   6篇
  1986年   5篇
  1985年   4篇
  1983年   4篇
  1977年   5篇
  1975年   6篇
  1974年   5篇
  1973年   6篇
  1972年   6篇
  1971年   7篇
  1968年   4篇
  1967年   4篇
  1966年   4篇
  1964年   6篇
  1955年   5篇
排序方式: 共有2587条查询结果,搜索用时 15 毫秒
11.
12.

Background

Objectives were to assess associations between intimate partner violence (IPV), violence during armed conflict (i.e. crisis violence), and probable post-traumatic stress disorder (PTSD).

Methods

Using a sample of 950 women in rural Côte d’Ivoire, logistic generalized estimating equations assessed associations between IPV and crisis violence exposures with past-week probable PTSD.

Results

Over one in 5 (23.4%) women reported past-year IPV, and over one in 4 women (26.5%) reported experiencing IPV prior to the past year (i.e. remote IPV). Crisis violence was experienced by 72.6% of women. In adjusted models including demographics, crisis violence (overall and specific forms), and IPV (remote and past-year), women who reported past-year IPV had 3.1 times the odds of reporting probable past-week PTSD (95%CI: 1.8–5.3) and those who reported remote IPV had 1.6 times the odds (95%CI: 0.9–2.7). Violent exposures during the crisis were not significantly associated with probable PTSD (any crisis violence: aOR: 1.04 (0.7–1.5); displacement: aOR: 0.9 (95%CI: 0.5–1.7); family victimization during crisis: aOR: 1.1 (95%CI: 0.8–1.7); personal victimization during crisis: aOR: 1.7 (95%CI: 0.7–3.7)).

Conclusion

Past-year IPV was more strongly associated with past-week probable PTSD than remote IPV and violence directly related to the crisis. IPV must be considered within humanitarian mental health and psychosocial programming.  相似文献   
13.
The Neuronal Ceroid Lipofuscinoses (NCL) are a group of fatal inherited neurodegenerative diseases in humans distinguished by a common clinical pathology, characterized by the accumulation of storage body material in cells and gross brain atrophy. In this study, metabolic changes in three NCL mouse models were examined looking for pathways correlated with neurodegeneration. Two mouse models; motor neuron degeneration (mnd) mouse and a variant model of late infantile NCL, termed the neuronal ceroid lipofuscinosis (nclf) mouse were investigated experimentally. Both models exhibit a characteristic accumulation of autofluorescent lipopigment in neuronal and non neuronal cells. The NMR profiles derived from extracts of the cortex and cerebellum from mnd and nclf mice were distinguished according to disease/wildtype status. In particular, a perturbation in glutamine and glutamate metabolism, and a decrease in γ-amino butyric acid (GABA) in the cerebellum and cortices of mnd (adolescent mice) and nclf mice relative to wildtype at all ages were detected. Our results were compared to the Cln3 mouse model of NCL. The metabolism of mnd mice resembled older (6?month) Cln3 mice, where the disease is relatively advanced, while the metabolism of nclf mice was more akin to younger (1-2?months) Cln3 mice, where the disease is in its early stages of progression. Overall, our results allowed the identification of metabolic traits common to all NCL subtypes for the three animal models.  相似文献   
14.
15.
The biogenesis of endothelial-specific Weibel-Palade bodies (WPB) is poorly understood, despite their key role in both haemostasis and inflammation. Biogenesis of specialized organelles of haemopoietic cells is often adaptor protein complex 3-dependent (AP-3-dependent), and AP-3 has previously been shown to play a role in the trafficking of both WPB membrane proteins, P-selectin and CD63. However, WPB are thought to form at the trans Golgi network (TGN), which is inconsistent with a role for AP-3, which operates in post-Golgi trafficking. We have therefore investigated in detail the mechanisms of delivery of these two membrane proteins to WPB. We find that P-selectin is recruited to forming WPB in the trans-Golgi by AP-3-independent mechanisms that use sorting information within both the cytoplasmic tail and the lumenal domain of the receptor. In contrast, CD63 is recruited to already-budded WPB by an AP-3-dependent route. These different mechanisms of recruitment lead to the presence of distinct immature and mature populations of WPB in human umbilical vein endothelial cells (HUVEC).  相似文献   
16.
The coordination chemistry of the metalloligand [Pt2(μ-S)2(PPh3)4] towards cobalt(II) and cobalt(III) centres has been explored using an electrospray ionisation mass spectrometry (ESI MS)-directed methodology. Reaction of [Pt2(μ-S)2(PPh3)4] with CoCl2·6H2O in methanol gave a green-yellow suspension of the known adduct [Pt2(μ-S)2(PPh3)4CoCl2], and the CoBr2 adduct could be similarly prepared. When in situ-generated [Pt2(μ-S)2(PPh3)4CoCl2] is reacted with 8-hydroxyquinoline (HQ) and base, the initial product is the cobalt(II) adduct [Pt2(μ-S)2(PPh3)4CoQ]+, which is then converted in air to the cobalt(III) adduct [Pt2(μ-S)2(PPh3)4CoQ2]+, isolated as its hexafluorophosphate salt. The corresponding picolinate (Pic) derivative [Pt2(μ-S)2(PPh3)4Co(Pic)2]+ was similarly prepared, however reaction of [Pt2(μ-S)2(PPh3)4], CoCl2·6H2O and 8-(tosylamino)quinoline (HTQ) produced only the cobalt(II) adduct [Pt2(μ-S)2(PPh3)4CoTQ]+. Reactions of [Pt2(μ-S)2(PPh3)4], CoCl2·6H2O and dithiocarbamates gave cobalt(III) complexes [Pt2(μ-S)2(PPh3)4Co(S2CNR2)2]+ [R = Et or R2 = (CH2)4], and proceeded much more rapidly, consistent with the known ability of the dithiocarbamate ligand to stabilize cobalt in higher oxidation states. A study of the fragmentation of cobalt(III) adducts by positive-ion ESI mass spectrometry indicated that [Pt2(μ-S)2(PPh3)4CoQ2]+ fragments to form the radical cation [Pt2(μ-S)2(PPh3)4]+, which could also be generated by ESI MS analysis of [Pt2(μ-S)2(PPh3)4] in methanol-NaOH solution. In contrast, the corresponding indium(III) derivative [Pt2(μ-S)2(PPh3)4InQ2]+, and the cobalt(III) dithiocarbamate [Pt2(μ-S)2(PPh3)4Co(S2CN(CH2)4)2]+ are much more reluctant to fragment under analogous conditions, and the differences are discussed in terms of cobalt(III) redox chemistry.  相似文献   
17.
To better understand the roles of gammadelta T cells in mucosal infection, we utilized Salmonella enterica serovar Typhimurium (Salmonella serovar Typhimurium) infection in cattle as it closely approximates Salmonella serovar Typhimurium-induced enterocolitis in humans. Protein and gene expression in alphabeta and gammadelta T cells derived from lymphatic ducts draining the gut mucosa in Salmonella serovar Typhimurium-infected calves were analyzed. In calves with enterocolitis, general gene expression trends in gammadelta T cells suggested subtle activation and innate response, whereas alphabeta T cells were relatively quiescent following Salmonella serovar Typhimurium infection. An increase in IL-2R alpha expression on gammadelta T cells from infected calves and results from in vitro assays suggested that gammadelta T cells were primed by Salmonella serovar Typhimurium LPS to better respond to IL-2 and IL-15. Together with gene expression trends in vivo, these data support early priming activation of target tissue gammadelta T cells during Salmonella serovar Typhimurium infection.  相似文献   
18.
Repeated exposure to elevated levels of glucocorticoids during development can have long‐term detrimental effects on survival and fitness, potentially associated with increased telomere attrition. Nestling birds are regularly handled for ecological research, yet few authors have considered the potential for handling‐induced stress to influence hormonally mediated phenotypic development or bias interpretations of subsequent focal measurements. We experimentally manipulated the handling experience of the semi‐precocial nestlings of European Storm Petrel Hydrobates pelagicus to simulate handling in a typical field study and examined cumulative effects on physiology and condition in late postnatal development. Neither baseline corticosterone (the primary glucocorticoid in birds), telomere length nor body condition varied with the number of handling episodes. The absence of a response could be explained if Storm Petrels did not perceive handling to be stressful or if there is dissociation of the hypothalamic–pituitary–adrenal axis from stressful stimuli in early life. Eliciting a response to a stressor may be maladaptive for cavity‐dwelling young that are unable to escape or defend themselves. Furthermore, avoiding elevated overall glucocorticoid exposure may be particularly important in a long‐lived species, in which accelerated early‐life telomere erosion could impact negatively upon longevity. We propose that the level of colony‐wide disturbance induced by investigator handling of young could be important in underlining species‐specific responses. Storm Petrel nestlings appear unresponsive to investigator handling within the limits of handling in a typical field study and handling at this level should not bias physiological and morphological measurements.  相似文献   
19.
20.
To determine the genetic regulation of "hair length" in the domestic cat, a whole-genome scan was performed in a multigenerational pedigree in which the "long-haired" phenotype was segregating. The 2 markers that demonstrated the greatest linkage to the long-haired trait (log of the odds > or = 6) flanked an estimated 10-Mb region on cat chromosome B1 containing the Fibroblast Growth Factor 5 (FGF5) gene, a candidate gene implicated in regulating hair follicle growth cycle in other species. Sequence analyses of FGF5 in 26 cat breeds and 2 pedigrees of nonbreed cats revealed 4 separate mutations predicted to disrupt the biological activity of the FGF5 protein. Pedigree analyses demonstrated that different combinations of paired mutant FGF5 alleles segregated with the long-haired phenotype in an autosomal recessive manner. Association analyses of more than 380 genotyped breed and nonbreed cats were consistent with mutations in the FGF5 gene causing the long-haired phenotype in an autosomal recessive manner. In combination, these genomic approaches demonstrated that FGF5 is the major genetic determinant of hair length in the domestic cat.  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