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   1142篇
  免费   96篇
  国内免费   1篇
  2023年   9篇
  2022年   19篇
  2021年   41篇
  2020年   21篇
  2019年   30篇
  2018年   25篇
  2017年   25篇
  2016年   35篇
  2015年   62篇
  2014年   71篇
  2013年   86篇
  2012年   109篇
  2011年   110篇
  2010年   57篇
  2009年   60篇
  2008年   70篇
  2007年   49篇
  2006年   69篇
  2005年   45篇
  2004年   46篇
  2003年   38篇
  2002年   31篇
  2001年   6篇
  2000年   6篇
  1999年   11篇
  1998年   22篇
  1997年   6篇
  1996年   7篇
  1995年   6篇
  1994年   7篇
  1993年   5篇
  1992年   4篇
  1991年   3篇
  1990年   5篇
  1989年   6篇
  1988年   4篇
  1987年   3篇
  1986年   2篇
  1984年   3篇
  1983年   4篇
  1982年   5篇
  1980年   2篇
  1978年   3篇
  1973年   2篇
  1972年   1篇
  1969年   2篇
  1964年   2篇
  1962年   1篇
  1961年   1篇
  1960年   1篇
排序方式: 共有1239条查询结果,搜索用时 375 毫秒
991.

Background

Ethnoveterinary knowledge is highly significant for persistence of traditional community-based approaches to veterinary care. This is of particular importance in the context of developing and emerging countries, where animal health (that of livestock, especially) is crucial to local economies and food security. The current survey documents the traditional veterinary uses of medicinal plants in the Lesser Himalayas-Pakistan.

Methods

Data were collected through interviews, focus groups, participant observation, and by administering questionnaires. A total of 105 informants aged between 20–75 years old who were familiar with livestock health issues (i.e. farmers, shepherds, housewives and herbalists) participated in the study.

Results

A total of 89 botanical taxa, belonging to 46 families, were reported to have ethnoveterinary applications. The most quoted families were Poaceae (6 taxa), Fabaceae (6), Asteraceae (5), and Polygonaceae (5). Adhatoda vasica was the most cited species (43%), followed by Trachyspermum ammi (37%), and Zanthoxylum armatum var. armatum (36%). About 126 medications were recorded against more than 50 veterinary conditions grouped into seven categories. The highest cultural index values were recorded for Trachyspermum ammi, Curcuma longa, Melia azedarach, Zanthoxylum armatum var. armatum and Adhatoda vasica. The highest informant consensus factor was found for pathologies related to respiratory and reproductive disorders. Comparison with the local plant-based remedies used in human folk medicine revealed that many of remedies were used in similar ways in local human phytotherapy. Comparison with other field surveys conducted in surrounding areas demonstrated that approximately one-half of the recorded plants uses are novel to the ethnoveterinary literature of the Himalayas.

Conclusion

The current survey shows a remarkable resilience of ethnoveterinary botanical knowledge in the study area. Most of the species reported for ethnoveterinary applications are wild and under threat. Thus, not only is it imperative to conserve traditional local knowledge of folk veterinary therapies for bio-cultural conservation motives, but also to assist with in-situ and ex-situ environmental conservation initiatives, which are urgently needed. Future studies that focus on the validation of efficacy of these ethnoveterinary remedies can help to substantiate emic concepts regarding the management of animal health care and for rural development programs.
  相似文献   
992.
In an unbiased approach to biomarker discovery, we applied a highly multiplexed proteomic technology (SOMAscan, SomaLogic, Inc, Boulder, CO) to understand changes in proteins from paired serum samples at enrollment and after 8 weeks of TB treatment from 39 patients with pulmonary TB from Kampala, Uganda enrolled in the Center for Disease Control and Prevention’s Tuberculosis Trials Consortium (TBTC) Study 29. This work represents the first large-scale proteomic analysis employing modified DNA aptamers in a study of active tuberculosis (TB). We identified multiple proteins that exhibit significant expression differences during the intensive phase of TB therapy. There was enrichment for proteins in conserved networks of biological processes and function including antimicrobial defense, tissue healing and remodeling, acute phase response, pattern recognition, protease/anti-proteases, complement and coagulation cascade, apoptosis, immunity and inflammation pathways. Members of cytokine pathways such as interferon-gamma, while present, were not as highly represented as might have been predicted. The top proteins that changed between baseline and 8 weeks of therapy were TSP4, TIMP-2, SEPR, MRC-2, Antithrombin III, SAA, CRP, NPS-PLA2, LEAP-1, and LBP. The novel proteins elucidated in this work may provide new insights for understanding TB disease, its treatment and subsequent healing processes that occur in response to effective therapy.  相似文献   
993.
994.
Worldwide concern over threats to natural resources and public health has led to increased efforts to monitor and assess environmental conditions. This has stimulated the need for development and application of select biological and ecological measurements, or indicators, that are responsive to environmental stress. Measures of bivalve mollusc defence activities, such as haemocyte density, phagocytic activity, locomotion and production of cytotoxic molecules; and haemolymph constituents, such as agglutinins and lysozyme, have potential as indicators and appear to be responsive to xenobiotic chemical insults in the aquatic environment. However, basic research on the relevance of these measurements in inferring resistance to disease or enhanced survival is currently insufficient, reducing their value as potential biomarkers to address environmental objectives. In addition, variation in defence activities caused by seasonal temperature and reproductive cycling, salinity changes, nutritional status, diseases and parasites, and genetic stocks is high and may limit applicability of bivalve defence-related measurements as indicators. This review examines these sources of variability and their possible implications for interpreting changes in bivalve defence activity as an indicator of stress. Examples of contaminant-induced changes in bivalve defence functions are described.  相似文献   
995.
A glance through Autophagy or any other journal in this field shows that it is very common to block autophagy by RNA interference-based knockdown of ATG mRNAs in mammalian cell lines. Our lab’s experience is that this approach can easily make for failed experiments because good knockdown of even essential autophagy regulators does not necessarily mean you will get good inhibition of autophagy, and, over time, cells can find ways to circumvent the inhibitory effects of the knockdown.  相似文献   
996.
Calorie restriction (CR) has been demonstrated to alter cytokine levels; however, its potential to modify sickness behavior (fever, anorexia, cachexia) has not. The effect of CR on sickness behavior was examined in male C57BL/6J mice fed ad libitum or restricted 25% (CR25%) or restricted 50% (CR50%) in food intake for 28 days and injected with 50 μg/kg of LPS on day 29. Changes in body temperature, locomotor activity, body weight, and food intake were determined. A separate cohort of mice were fed ad libitum or CR50% for 28 days, and hypothalamic mRNA expression of inhibitory factor κB-α (IκB-α), cyclooxygenase-2 (COX-2), prostaglandin E(2) (PGE(2)), suppressor of cytokine signaling 3 (SOCS3), IL-10, neuropeptide Y (NPY), leptin, proopiomelanocortin (POMC), and corticotrophin-releasing hormone (CRH) were determined at 0, 2, and 4 h post-LPS. CR50% mice did not develop fevers, whereas the CR25% mice displayed a fever shorter in duration but with the same peak as the controls. Both CR25% and CR50% mice showed no sign of anorexia and reduced cachexia after LPS administration. Hypothalamic mRNA expression of NPY and CRH were both increased by severalfold in CR50% animals preinjection compared with controls. The CR50% mice did not demonstrate the expected rise in hypothalamic mRNA expression of COX-2, microsomal prostaglandin E synthase-1, POMC, or CRH 2 h post-LPS, and leptin expression was decreased at this time point. Increases in SOCS3, IL-10, and IκB-α expression in CR50% animals were enhanced compared with ad libitum-fed controls at 4 h post-LPS. CR results in a suppression of sickness behavior in a dose-dependent manner, which may be due to CR attenuating proinflammatory pathways and enhancing anti-inflammatory pathways.  相似文献   
997.
Growth factor erv1-like (Gfer) is an evolutionarily conserved sulfhydryl oxidase that is enriched in embryonic and adult stem cells and plays an essential prosurvival role in pluripotent embryonic stem cells. Here we show that knockdown (KD) of Gfer in hematopoietic stem cells (HSCs) compromises their in vivo engraftment potential and triggers a hyper-proliferative response that leads to their exhaustion. KD of Gfer in HSCs does not elicit a significant alteration of mitochondrial morphology or loss of cell viability. However, these cells possess significantly reduced levels of the cyclin-dependent kinase inhibitor p27(kip1). In contrast, overexpression of Gfer in HSCs results in significantly elevated total and nuclear p27(kip1). KD of Gfer results in enhanced binding of p27(kip1) to its inhibitor, the COP9 signalosome subunit jun activation-domain binding protein 1 (Jab1), leading to its down-regulation. Conversely, overexpression of Gfer results in its enhanced binding to Jab1 and inhibition of the Jab1-p27(kip1) interaction. Furthermore, normalization of p27(kip1) in Gfer-KD HSCs rescues their in vitro proliferation deficits. Taken together, our data demonstrate the presence of a novel Gfer-Jab1-p27(kip1) pathway in HSCs that functions to restrict abnormal proliferation.  相似文献   
998.
A field study was conducted in forested plots near Lansing, Michigan in 2008 and 2009 to evaluate the newly introduced egg parasitoid Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) for control of the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). To measure parasitism by O. agrili, laboratory-reared “sentinel EAB eggs” were deployed under bark flaps on trunks of selected ash trees in both parasitoid-release and non-release control plots. In addition, naturally occurring EAB eggs were collected in both parasitoid-release and control plots to measure parasitism. While no parasitism was detected with either sentinel or naturally occurring EAB eggs in control plots in either 2008 or 2009, a low level of parasitism by O. agrili was detected in the parasitoid-release plots in both artificially deployed sentinel eggs (?1%) and field-collected, naturally occurring eggs (1.1–4.2%) in both years. In addition to losses due to parasitism by O. agrili, a large proportion (37–52%) of the field-deployed sentinel eggs disappeared, possibly due to predators such as ants, in both parasitoid-release and control plots. While no statistical differences in parasitism by O. agrili were detected between parasitoid release and control plots, other sources of egg mortality such as disappearance due to predation on eggs, varied significantly across study sites in both 2008 and 2009. The relevance of these findings to future release and evaluation strategies for O. agrili for biological control of the invasive emerald ash borer in the US is discussed.  相似文献   
999.
The overexpression of the pro-apoptotic protein Prostate Apoptosis Response Protein-4 in colon cancer has been shown to increase response to the chemotherapeutic agent 5-fluorouracil (5-FU). Although colon cancer cells endogenously express Par-4, the presence or overexpression of Par-4 alone does not cause apoptosis. We hypothesize that Par-4 is inactivated in colon cancer. In colon cancer, the levels and the kinase activity of the nonreceptor tyrosine kinase c-Src increase with tumor progression. One of the downstream effectors of c-Src is Akt1. Akt1 has been shown to inhibit the pro-apoptotic activity of Par-4 in prostate cancer cells. We therefore investigated the potential of activating Par-4 by inhibiting c-Src. Colon carcinoma cell lines were treated with the Src kinase inhibitor 4-amino-5-(4-chlorophenyl)-7-(dimethylethyl)pyrazolo[3,4-d]pyrimidine (PP2) in combination with the chemotherapeutic agent 5-FU. Treating cells with PP2 and 5-FU resulted in reduced interaction of Par-4 with Akt1 and with the scaffolding protein 14-3-3σ, and mobilization of Par-4 to the nucleus. Par-4 was shown to interact not only with Akt1 and 14-3-3σ, but also with c-Src. Overexpression of c-Src induced the phosphorylation of Par-4 at tyrosine site/s. Thus, in this study, we have shown that Par-4 can be activated by inhibiting Src with a pharmacological inhibitor and adding a chemotherapeutic agent. The activation of the pro-apoptotic protein Par-4 as reported in this study is a novel mechanism by which apoptosis occurs with a Src kinase inhibitor and 5-FU. In addition, we have demonstrated that the pro-apoptotic activity of endogenously expressed Par-4 can be increased in colon cancer cells.  相似文献   
1000.
In this article I use the US H2A guest worker programme as a lens through which to analyse the gender subjectivities of Mexican transnational fathers. My qualitative findings highlight the ways in which the prioritization of productive over reproductive labour within the H2A programme exploits gender-based expectations within Mexican families, reproducing rigid gender divisions of family labour. Additionally, the subjectivities of guest worker fathers are influenced by cultural expectations as well as by the rurality and cyclicality of their lives. As fathers shift between the USA and Mexico, so do their gender subjectivities, symbolizing gender's fluidity. Findings complicate the oft-cited conclusion that emotional labour and sacrifice are the exclusive domain of transnational mothers.  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