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   116篇
  免费   11篇
  国内免费   1篇
  2023年   1篇
  2022年   3篇
  2021年   12篇
  2019年   2篇
  2018年   8篇
  2017年   7篇
  2016年   13篇
  2015年   14篇
  2014年   5篇
  2013年   4篇
  2012年   8篇
  2011年   7篇
  2010年   2篇
  2009年   6篇
  2008年   8篇
  2007年   8篇
  2006年   4篇
  2005年   4篇
  2004年   2篇
  2003年   1篇
  2002年   5篇
  2001年   1篇
  2000年   1篇
  1992年   1篇
  1971年   1篇
排序方式: 共有128条查询结果,搜索用时 31 毫秒
31.
32.
33.
In the present study D. discoideum has been used as a model organism to understand the role of poly (ADP-ribose) polymerase (PARP) in caspase independent paraptotic cell death pathways. D. discoideum lacks caspases and Bcl-2 family proteins; nevertheless it has 9 potential genes for PARP. PARP has been known to get activated in various cell death associated diseases. In this study kinetics of cell death induced by staurosporine (STS), a bacterial alkaloid, was established to unravel the role of PARP. It was found that STS induced cell death in D. discoideum did not involve PARP activation, however it involved cathepsin D. Results indicated that an alternative mechanism may be existing in D. discoideum that lacks Bcl-2 family proteins for STS induced cell death that evades Bax involvement.  相似文献   
34.
The horizontal gene transfer of plasmid-determined stress tolerance was achieved under lab conditions. Bacterial isolates, Enterobacter cloacae (DGE50) and Escherichia coli (DGE57) were used throughout the study. Samples were collected from contaminated marine water and soil to isolate bacterial strains having tolerance against heavy metals and antimicrobial agents. We have demonstrated plasmid transfer, from Amp+Cu+Zn strain (DGE50) to AmpCuZn+ strain (DGE57), producing Amp+Cu+Zn+ transconjugants (DGETC50→57) and Amp+CuZn+ transformants (DGETF50→57). DGE57 did not carry any plasmid, therefore, it can be speculated that zinc tolerance gene in DGE57 is located on chromosome. DGE50 was found to carry three plasmids, out of which two were transferred through conjugation into DGE57, and only one was transferred through transformation. Plasmid transferred through transformation was one out of the two transferred through conjugation. Through the results of transformation it was revealed that the genes of copper and ampicillin tolerance in DGE50 were located on separate plasmids, since only ampicillin tolerance genes were transferred through transformation as a result of one plasmid transfer. By showing transfer of plasmids under lab conditions and monitoring retention of respective phenotype via conjugation and transformation, it is very well demonstrated how multiple stress tolerant strains are generated in nature.  相似文献   
35.
Pancreatic ribonuclease A (RNase A) has been shown to aggregate moderately and gradually at 65 degrees C. Antibodies raised against the dodecapeptide KETAAAKFERQG corresponding to the N-terminal 1-12 amino acid residues of RNase A (Npep) as well as native RNase A were effective in lowering RNase A aggregation at 65 degrees C. The antiRNase A antibodies were, however, more protective. The binding of antiNpep antibodies to the N-terminal region of RNase A may interfere with initiation of oligomerization of the enzyme and consequently its aggregation. The antiRNase A antibodies were presumably more effective in protecting RNase A against aggregation by binding to multiple epitopes of the enzyme including the N-terminal region and hence restricting the interaction of the monomers.  相似文献   
36.
Greenhouse experiments were conducted to assess the effect of salinisation of soil on emergence, growth, water content, proline content and mineral accumulation of seedlings of Delonix regia (Hook.) Raf. (Fabaceae). Sodium chloride (NaCl) was added to the soil and salinity was maintained at 0.3, 1.9, 3.9, 6.0 and 7.9 dS m?1. A negative relationship between seedling emergence and salt concentration was obtained. Salinity caused reduction in water content and water potential of tissues (leaves, stems, tap roots and lateral roots) that resulted in internal water deficit to plants. Consequently, shoot and root elongation, leaf expansion and dry matter accumulation in leaves, stems, tap roots and lateral root tissues of seedlings significantly decreased in response to increasing concentration of salt. Proline content in tissues was very low. There were no effective mechanisms to control net uptake of Na on root plasma membrane and subsequently its transport to shoot tissues. Potassium content significantly decreased in tissues in response to salinisation of soil. This tree species is a moderate salt-tolerant glycophytic plant. Nitrogen and calcium content in tissues significantly decreased as soil salinity increased. Phosphors content in tissues exhibited a declining trend with increase in soil salinity. Changes in tissues and whole-plant accumulation pattern of other elements tested, as well as possible mechanisms for avoidance of Na toxicity in this tree species in response to salinisation, are discussed.  相似文献   
37.
38.
BACKGROUND:The COVID-19 pandemic has exacerbated disparities in poverty and illness for people in vulnerable circumstances in ethnocultural communities. We sought to understand the evolving impacts of COVID-19 on ethnocultural communities to inform intersectoral advocacy and community action.METHODS:The Illuminate Project used participatory action research, with cultural health brokers as peer researchers, from Sept. 21 to Dec. 31, 2020, in Edmonton, Alberta. Twenty-one peer researchers collected narratives from members of ethnocultural communities and self-interpreted them as they entered the narratives into the SenseMaker platform, a mixed-method data collection tool. The entire research team analyzed real-time, aggregate, quantitative and qualitative data to identify emerging thematic domains, then visualized these domains with social network analysis.RESULTS:Brokers serving diverse communities collected 773 narratives. Identified domains illuminate the evolving and entangled impacts of COVID-19 including the following: COVID-19 prevention and management; care of acute, chronic and serious illnesses other than COVID-19; maternal care; mental health and triggers of past trauma; financial insecurity; impact on children and youth and seniors; and legal concerns. We identified that community social capital and cultural brokering are key assets that facilitate access to formal health and social system supports.INTERPRETATION:The Illuminate Project has illustrated the entangled, systemic issues that result in poor health among vulnerable members of ethnocultural communities, and the exacerbating effects of COVID-19, which also increased barriers to mitigation. Cultural brokering and community social capital are key supports for people during the COVID-19 pandemic. These findings can inform policy to reduce harm and support community resiliency.

Mahatma Gandhi observed that “the true measure of any society can be found in how it treats its most vulnerable members.” Ethnocultural communities, defined by their unique shared characteristics (e.g., cultural traditions, language, country of origin),1 face greater challenges and have higher rates of poverty and illness than the general Canadian population. Migration results in conditions that affect all social determinants of health and disproportionally affect health outcomes, herein referred to as vulnerable circumstances.2,3 The emergence of major outbreaks of SARS-CoV-2 infections in ethnocultural communities highlights both the vulnerable circumstances of these communities and the disparities they face in accessing high-quality, culturally appropriate information and support.47 Studies have shown substantial variation in deaths attributed to COVID-19 based on factors such as age, sex, ethnicity, length of time in Canada, income and education.811 However, given the well-known gap in reporting comprehensive COVID-19 data in relation to race and ethnicity, efforts to measure its impact are hampered.812 There is an urgent need to understand the evolving challenges of COVID-19 to inform action and public policy that can mitigate these challenges.To understand evolving situations of complexity and crisis, sensemaking, defined as “a continuous process to establish situational awareness,”13 is a crucial undertaking.14 Using participatory action research,1518 we sought to understand the evolving impacts of COVID-19 on ethnocultural communities to inform broader national efforts to migitate the impacts of COVID-19. Particularly, we sought to understand how the challenges of COVID-19 are entangled with contextual factors at multiple levels, how families and communities are leveraging strengths and social capital to adapt, and the role of cultural brokers in managing the crisis.  相似文献   
39.
Iron overload has been shown to enhance chemically mediated cutaneous tumor promotion in animals. However, the majority of these animal studies have used high concentrations of iron before initiating tumor development. The current study was designed to evaluate the effect of small doses of iron on the promotion stage of chemically mediated cutaneous carcinogenesis. We found an increased tumor response in mice initiated with dimethylbenz(a)anthracene (DMBA) when iron at the dose levels of 0.5, 1.0, and 1.5mg/mouse was injected (intramuscularly) once a week into mice at the promotion stage of skin carcinogenesis, employing 12-O-tetradecanoyl phorbol-13-acetate (TPA)/benzoyl peroxide (BPO) as tumor promoter. The appearance of first papilloma and the number of tumors/mouse were recorded weekly. When compared to the control (non-iron-treated) group, the iron-treated groups showed an augmented incidence of tumors and number of tumors/mouse. In iron-treated mice, tumors appeared earlier than in the control group. TPA/BPO treatment resulted in a significant decrease in the activities of antioxidant enzymes and depletion in the level of epidermal reduced glutathione (GSH). TPA treatment in non-iron-treated mice resulted in approximately 20-40% decrease in GSH level and in the activities of antioxidant enzymes, whereas 1.5-mg iron treatment along with TPA treatment resulted in about approximately 30-70% decrease in GSH level and in the activities of antioxidant enzymes. Similarly, treatment of iron along with BPO treatment resulted in a dose-dependent higher depletion of GSH and the antioxidant enzymes as compared to non-iron-treated animals treated with BPO. Further, TPA/BPO-mediated induction in ornithine decarboxylase activity and [3H]thymidine incorporation in cutaneous DNA was approx two- to threefold higher in mice treated with iron as compared to non-iron-treated mice. Cutaneous lipid peroxidation and iron levels were also higher in mice treated with iron as compared to non-iron-treated mice. These data suggest that progressive iron overload can enhance the tumor promotion ability of TPA/BPO in DMBA-initiated murine skin.  相似文献   
40.
Fazal  Hina  Akram  Muhammad  Ahmad  Nisar  Qaisar  Muhammad  Kanwal  Farina  Rehman  Gohar  Ullah  Irfan 《Protoplasma》2023,260(2):557-570
Protoplasma - The Mentha species of family Lamiaceae are famous for their flavor and are commercially used in many food products worldwide. They are widely used to cure digestive problems as well...  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