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   11篇
  免费   0篇
  2017年   1篇
  2016年   1篇
  2011年   1篇
  2010年   1篇
  2008年   2篇
  2005年   1篇
  1999年   2篇
  1995年   1篇
  1990年   1篇
排序方式: 共有11条查询结果,搜索用时 25 毫秒
1.
We investigated the efficacy of Ocimum basilicum (OB) essential oils for treating depression related behavioral, biochemical and histopathological changes caused by exposure to chronic unpredictable mild stress (CUMS) in mice and to explore the mechanism underlying the pathology. Male albino mice were divided into four groups: controls; CUMS; CUMS plus fluoxetine, the antidepressant administered for pharmacological validation of OB; and CUMS plus OB. Behavioral tests included the forced swim test (FST), elevated plus-maze (EPM) and the open ?eld test (OFT); these tests were performed at the end of the experiment. We assessed serum corticosterone level, protein, gene and immunoexpression of brain-derived neurotropic factor (BDNF) and glucocorticoid receptors (GRs) as well as immunoexpression of glial fibrillary acidic protein (GFAP), Ki67, caspase-3 in the hippocampus. CUMS caused depression in the mice as evidenced by prolonged immobility in the FST, prolonged time spent in the open arms during the EPM test and reduction of open field activity in the OFT. OB ameliorated the CUMS induced depressive status. OB significantly reduced the corticosterone level and up-regulated protein and gene expressions of BDNF and GR. OB reduced CUMS induced hippocampal neuron atrophy and apoptosis, and increased the number of the astrocytes and new nerve cells. OB significantly increased GFAP-positive cells as well as BDNF and GR immunoexpression in the hippocampus.  相似文献   
2.
In this work, a method for improved protein identification of low-abundance proteins using unstained gels, in combination with robotics and matrix-assisted laser desorption/ionization tandem mass spectrometry, has been developed and evaluated. Omitting the silver-staining process resulted in increased protein identification scores, an increase in the number of peptides observed in the MALDI mass spectrum, and improved quality of the tandem mass spectrometry data.  相似文献   
3.
Transient expression of recombinant plasmids carrying the lacZ gene under the control of either bovine αSl-casein gene tissue-specific promoter-enhancer region or highly homologous goat αSl-casein gene promoter-enhancer region with supplementary regulatory sequences of the goat gene were studied in Misgurnus fossilis L. loach embryos. It has been shown previously that the expression of the constructs carrying these regulatory elements in transgenic mice occurred primarily in the mammary glands. At early developmental stages, loach embryos and early prelarvae showed nonspecific and mosaic transient expression of lacZ carrying casein regulatory sequences. Transgenic activity was the highest in 1–3-day embryos. At the same time, the efficiency of expression of lacZ gene carrying regulatory sequences of the αSl-casein gene of goat was higher than with the promoter-enhancer region of the bovine αSl-casein gene. Thus, regulatory sequences of the bovine or goat αSl-casein gene appeared capable of providing similar transient expression of reporter gene in the loach embryos. This model can be used for rapid testing of promoter-enhancer activity of transgenes.  相似文献   
4.
Transient expression of recombinant plasmids carrying the lacZ gene under the control of either bovine alphaS1-casein gene tissue-specific promoter-enhancer region or highly homologous goat alphaS1-casein gene promoter-enhancer region with supplementary regulatory sequences of the goat gene were studied in Misgurnus fossilis L. loach embryos. It has been shown previously that the expression of the constructs carrying these regulatory elements in transgenic mice occurred primarily in the mammary glands. At early developmental stages, loach embryos and early prelarvae showed nonspecific and mosaic transient expression of lacZ carrying casein regulatory sequences. Transgenic activity was the highest in 1-3-day embryos. At the same time, the efficiency of expression of lacZ gene carrying regulatory sequences of the alphaS1-casein gene of goat was higher than with the promoter-enhancer region of the bovine alphaS1-casein gene. Thus, regulatory sequences of the bovine or goat alphaS1-casein gene appeared capable of providing similar transient expression of reporter gene in the loach embryos. This model can be used for rapid testing of promoter-enhancer activity of transgenes.  相似文献   
5.
6.
7.
Based on review and original data, this synthesis investigates carbon pools and fluxes of Siberian and European forests (600 and 300 million ha, respectively). We examine the productivity of ecosystems, expressed as positive rate when the amount of carbon in the ecosystem increases, while (following micrometeorological convention) downward fluxes from the atmosphere to the vegetation (NEE = Net Ecosystem Exchange) are expressed as negative numbers. Productivity parameters are Net Primary Productivity (NPP=whole plant growth), Net Ecosystem Productivity (NEP = CO2 assimilation minus ecosystem respiration), and Net Biome Productivity (NBP = NEP minus carbon losses through disturbances bypassing respiration, e.g. by fire and logging). Based on chronosequence studies and national forestry statistics we estimate a low average NPP for boreal forests in Siberia: 123 gC m–2 y–1. This contrasts with a similar calculation for Europe which suggests a much higher average NPP of 460 gC m–2 y–1 for the forests there. Despite a smaller area, European forests have a higher total NPP than Siberia (1.2–1.6 vs. 0.6–0.9 × 1015 gC region–1 y–1). This arises as a consequence of differences in growing season length, climate and nutrition. For a chronosequence of Pinus sylvestris stands studied in central Siberia during summer, NEE was most negative in a 67-y old stand regenerating after fire (– 192 mmol m–2 d–1) which is close to NEE in a cultivated forest of Germany (– 210 mmol m–2 d–1). Considerable net ecosystem CO2-uptake was also measured in Siberia in 200- and 215-y old stands (NEE:174 and – 63 mmol m–2 d–1) while NEP of 7- and 13-y old logging areas were close to the ecosystem compensation point. Two Siberian bogs and a bog in European Russia were also significant carbon sinks (– 102 to – 104 mmol m–2 d–1). Integrated over a growing season (June to September) we measured a total growing season NEE of – 14 mol m–2 summer–1 (– 168 gC m–2 summer–1) in a 200-y Siberian pine stand and – 5 mol m–2 summer–1 (– 60 gC m–2 summer–1) in Siberian and European Russian bogs. By contrast, over the same period, a spruce forest in European Russia was a carbon source to the atmosphere of (NEE: + 7 mol m–2 summer–1 = + 84 gC m–2 summer–1). Two years after a windthrow in European Russia, with all trees being uplifted and few successional species, lost 16 mol C m–2 to the atmosphere over a 3-month in summer, compared to the cumulative NEE over a growing season in a German forest of – 15.5 mol m–2 summer–1 (– 186 gC m–2 summer–1; European flux network annual averaged – 205 gC m–2 y–1). Differences in CO2-exchange rates coincided with differences in the Bowen ratio, with logging areas partitioning most incoming radiation into sensible heat whereas bogs partitioned most into evaporation (latent heat). Effects of these different surface energy exchanges on local climate (convective storms and fires) and comparisons with the Canadian BOREAS experiment are discussed. Following a classification of disturbances and their effects on ecosystem carbon balances, fire and logging are discussed as the main processes causing carbon losses that bypass heterotrophic respiration in Siberia. Following two approaches, NBP was estimated to be only about 13–16 mmol m–2 y–1 for Siberia. It may reach 67 mmol m–2 y–1 in North America, and about 140–400 mmol m–2 y–1 in Scandinavia. We conclude that fire speeds up the carbon cycle, but that it results also in long-term carbon sequestration by charcoal formation. For at least 14 years after logging, regrowth forests remain net sources of CO2 to the atmosphere. This has important implications regarding the effects of Siberian forest management on atmospheric concentrations. For many years after logging has taken place, regrowth forests remain weaker sinks for atmospheric CO2 than are nearby old-growth forests.  相似文献   
8.
Permanent mounting of fourth instar mosquito larvae is essential for identifying Aedes spp. This procedure requires extensive exposure to xylene, a clearing agent in the mounting process. We investigated wintergreen oil as a substitute for xylene. Five hundred larvae were mounted on slides to evaluate shrinkage or expansion of specimens after clearing using xylene or wintergreen oil. We examined the ventral brush and siphonal hair tufts for species identification and for preservation of morphological characteristics after clearing specimens in xylene or wintergreen oil. Shrinkage of the length of whole larvae and width of the head, thorax and abdomen after mounting was significantly greater after clearing with xylene than with wintergreen oil. The length of the comb scale nearest the ventral brush was similar for both clearing agents. The clarity of the specimens after mounting was improved by clearing with wintergreen oil, but the integrity of the ventral brush and siphonal hair tufts were similar for both clearing agents.  相似文献   
9.
Jing L  Parker CE  Seo D  Hines MW  Dicheva N  Yu Y  Schwinn D  Ginsburg GS  Chen X 《Proteomics》2011,11(14):2763-2776
Due to the lack of precise markers indicative of its occurrence and progression, coronary artery disease (CAD), the most common type of heart diseases, is currently associated with high mortality in the United States. To systemically identify novel protein biomarkers associated with CAD progression for early diagnosis and possible therapeutic intervention, we employed an iTRAQ‐based quantitative proteomic approach to analyze the proteome changes in the plasma collected from a pair of wild‐type versus apolipoprotein E knockout (APOE?/?) mice which were fed with a high fat diet. In a multiplex manner, iTRAQ serves as the quantitative ‘in‐spectra’ marker for ‘cross‐sample’ comparisons to determine the differentially expressed/secreted proteins caused by APOE knock‐out. To obtain the most comprehensive proteomic data sets from this CAD‐associated mouse model, we applied both MALDI and ESI‐based mass spectrometric (MS) platforms coupled with two different schemes of multidimensional liquid chromatography (2‐D LC) separation. We then comparatively analyzed a series of the plasma samples collected at 6 and 12 wk of age after the mice were fed with fat diets, where the 6‐ or 12‐wk time point represents the early or intermediate phase of the fat‐induced CAD, respectively. We then categorized those proteins showing abundance changes in accordance with APOE depletion. Several proteins such as the γ and β chains of fibrinogen, apolipoprotein B, apolipoprotein C‐I, and thrombospondin‐4 were among the previously known CAD markers identified by other methods. Our results suggested that these unbiased proteomic methods are both feasible and a practical means of discovering potential biomarkers associated with CAD progression.  相似文献   
10.
Rapid evolutionary change is increasingly being recognized as commonplace, but the evolutionary consequences for species and ecosystems under human‐induced selection regimes have not been explored in detail, although many species occur in such environments. In a common garden experiment and with amplified fragment length polymorphism markers, we examined whether genetic differentiation has taken place between spatially intermixed populations of creeping thistles Cirsium arvense (Asteraceae) collected from a natural habitat (maritime shores), a semi‐natural habitat (road verges) and arable fields under two management regimes: conventional and organic farming. Populations of C. arvense have altered genetically and locally adapted their growth patterns with changed land use. Although plants from different habitats showed similar total biomass production, shoot and root production was higher for maritime populations, suggesting selection for increased competitive ability. Competitive ability then declined in the order semi‐natural, conventional farms and organic farms. Thistles in arable fields may be more selected for tolerance against disturbances from herbicides and mechanical weed control. In addition, early shoot sprouting and genetic analysis showed differentiation between plants originating from conventional farms and farms that were converted to organic 9–30 years ago, suggesting some adaptation to altered crop cultivation practices. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 797–807.  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