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991.
AIM: To investigate the effect of uric acid on the maturation and the biological function of murine bone-marrow derived dendritic cells (BMDCs) in vitro.METHODS: BMDCs were cultured with GM-CSF, IL-4, LPS and uric acid. Cell phenotypes were analyzed by flow cytometry. MTT was used to detect the effect of uric acid on the function of BMDCs in stimulating the proliferation of T cells. IL-12 released by BMDCs was also detected. RESULTS: BMDCs were cultured and identified. Uric acid at concentrations of 200 mg/L and 400 mg/L increased the expression of the molecules (CD11c, CD83, CD86, IA/IE) on BMDCs surface and the IL-12 level in the culture supernatants (P<0.05), promoted the proliferation of T cells at the T: DC rate 5∶1, 10∶1, 20∶1 (P<0.05). However, uric acid at concentration of 70 mg/L had no effect on above molecule expression (P>0.05), no effect on T cell proliferation with BMDCs (P>0.05) was observed. CONCLUSION: Uric acid promotes the differentiation, maturation, the expression of co-stimulatory molecules, the IL-12 production in BMDCs and enhances the ability of BMDCs to stimulate the proliferation of T cell in a specical dose range. 相似文献
992.
Depletion of the protective ozone layer in the atmosphere leads to increasing UV‐B radiation on the earth's surface with potential effects on the response of plants to different stresses. Abutilon theophrasti, Amaranthus retroflexus, Digitaria sanguinalis and Chloris virgata are common weeds encountered in most arable fields in China. The effectiveness of herbicides used in controlling these weeds needs to be evaluated with increased UV‐B radiation. Seedlings of these four weeds were therefore grown under ambient and elevated UV‐B radiation to compare the efficacy of paraquat, a commonly used contact herbicide. Irrespective of species sensitivity to radiation, the elevated UV‐B radiation decreased the effectiveness of paraquat. Net photosynthesis rate was adversely affected except for D. sanguinalis, while the chlorophyll content was significantly reduced in A. retroflexus and C. virgata. UV‐B treatment increased the leaf surface wax and decreased the absorption of 14C‐paraquat in A. theophrasti, D. sanguinalis and C. virgata. These results suggest that the response of weeds to paraquat or the use of the herbicide may be affected by increased UV‐B radiation, to the extent that larger doses may be required to achieve desired effects. This may have damaging consequences for the environment. 相似文献
993.
994.
田海芹 《内蒙古林业调查设计》2013,36(2):126-128
近年来,由于温室气体CO2在大气中含量的急剧增加,导致全球变暖日趋严重。针对这一现状,我国积极倡导发展碳汇林业。文章阐述了碳汇林业的概念、碳汇林业的项目案例以及我国发展碳汇林业的重大意义,并对发展碳汇林业过程中存在的问题提出了可行性建议。 相似文献
995.
LUO Dan SHU Sai-nan ZHOU Yu-feng LIU Xing-lou TIAN Jia WANG Hui ZHOU Hua LI Ge FANG Feng 《园艺学报》2009,25(11):2173-2181
AIM: The influence of MCMV infection on differentiation and differentiation gene expression in neural stem cells(NSCs) in vitro were investigated for studying the mechanisms of brain abnormalities caused by congenital cytomegalovirus infection.METHODS: NSCs were separated from fetal BALB/C mouse, and cultured and identified in vitro. The differentiation potency of NSCs was observed by immunofluorescence. The NSCs infected by MCMV at dosage of MOI(multiplicity of infection) equaled to 5, 1 and 0.1,respectively, were cultured in differentiation medium. The morphological changes of infected cells were observed under inverted microscope. The ratios of NSCs and its differentiated cells were detected by flow cytometry. The expressions of nestin, GFAP and NSE, markers of NSCs and its differentiated cells, were studied by immunofluorescence(MOI=1). The expression of early antigen(EA) of MCMV was detected to observe the infection process. Real-time RT-PCR method was employed to measure the expression levels of the key genes Neurog2, Myc and Ccnd1 in Wnt signal pathway of NSCs at early stage of differentiation culture.RESULTS: NSCs isolated from embryonic mouse brains proliferated to form neurospheres, strongly expressed nestin and differentiated into NF-200 positive neurons or GFAP positive astrocytes. The infected NSCs did not adhere to the wall and appeared differentiation growths, but showed swollen gradually after differentiation culture. The nestin expression in the infected cells downregulated slowly and was higher than that in control groups(P<0.05). The GFAP and NSE expressions of the infected cells were lower than those in control groups(P<0.05). The early antigen(EA) of MCMV was always detected in the cells in infected groups. The ratios of nestin positive cells in infected groups were higher than those in control groups, but the ratios of GFAP and NSE positive cells of former were lower than that of the latter from 3rd to 9th d after differentiation culture(P<0.05). The levels of Neurog2 mRNA and Myc mRNA in infected groups were markedly lower than those in normal control groups on 1st d and from 1st to 4th d after differentiation culture, respectively(P<0.05). The levels of Ccnd1 mRNA of infected groups were obviously lower than those in normal control groups from 12th h to 1st d(P<0.05). These changes in infected groups became more obvious as MCMV MOI increased.CONCLUSION: MCMV significantly inhibits differentiation of NSCs to neurons and astrocytes, and leads to the decrease in differentiated cells. MCMV inhibits or interferes with the gene expression of Neurog2, Myc and Ccnd1 in Wnt signal pathway of NSCs. The effect that MCMV inhibits the expressions of differentiation and the differentiation genes in NSCs shows dose-dependent with MCMV MOI. The inhibitory effect of MCMV on the differentiation of NSCs might be induced by interfering with the expression of differentiation gene in NSCs, which is possibly the one of primary causes of brain development disorders induced by congenital CMV infection. 相似文献
996.
1农田刈割草地是农区草业的重要发展方向 目前我国90%的畜牧业产品来自农区,例如以畜牧业著称的内蒙古自治区,畜牧业总产值中农区畜牧业占70%,纯牧区的畜牧业仅占30%,1986年作为畜牧业生产基地内蒙古自治区产肉只有35万t,而纯农区江苏省却达到120万t,四川省为240万t,在今后相当时期内,农区仍然是我国畜牧产业的重点.据统计我国每年需牧草1000万t,生产能力只有200万t,并且供需之间的缺口还将随着我国畜禽业年平均增长10%以上的发展速度继续拉大. 相似文献
997.
田勇军 《信阳农业高专学报》2008,18(1):41-43
行政法律咨询机构,是指向行政机构提供法律方面的意见、建议为主的非行政性的组织和团体。建立行政法律咨询机构,应在人员构成上,不受政府干涉,保持相对独立性。在活动经费上应有保障。在机构内部应有章程制约。 相似文献
998.
超级杂交稻“种三产四”丰产工程示范进展及发展对策 总被引:6,自引:3,他引:3
2007-2008年在湖南20个县(市、区)实施了超级杂交稻"种三产四"丰产工程,针对各地区不同的生态类型,设计了超级杂交稻的5种种植模式,选择了11个主推超级杂交稻组合和9项主推技术,通过技术培训、示范带动、举办现场会议和总结交流经验及严密的组织管理,项目获得了成功.2007年20个县总示范面积584.9 hm2,有18个县达到了增产33%的"种三产四"目标,2008年20个县总示范面积7 023.6 hm2,19个县达到增产目标.总结了项目实施中存在的主要问题,提出了相应的发展对策. 相似文献
999.
北方城市地被植物应用质量评价方法探讨 总被引:5,自引:0,他引:5
根据地被植物固有的特征和北方城市配置应用特点,将地被植物分为基础型地被、骨干型地被和点缀型地被3类。运用频数统计法选择株高、生育期、观赏价值、绿色期、覆盖力、生长势、适应性、养护频度8项指标,构建了地被植物外观质量、生态质量和使用质量3大指标体系。制定评价标准,采用综合指数评价法,验证地被植物的质量等级。通过实例分析验证,该质量评价指标体系和评价方法具有较强的科学性和可操作性,评价结果符合客观实际,对于北方城市地被植物的评价选择应用,具有普遍的适应性和推广价值。 相似文献
1000.