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991.
面对发展高成本时代的到来,农民企业家对城市发展成本的调节在于推进农村工业化、城乡一体化的进程,促进市场机会的均等和平均利润的形成,主要途径有:形成多种经营方式,使要素成本发挥最大效益;促进产品价值的实现,使农村沉没成本被买单;影响供求弹性,降低市场统一进程成本;促进制度建构与秩序内生,分摊改革成本。对衡阳市合江套片区发展成本的调节进行估算得知,如果农民企业家参与片区开发,县域经济发展成本可以节约270万元/hm^2。 相似文献
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基于16S rRNA基因克隆文库技术分析广西富钟水牛瘤胃产甲烷菌组成及多样性 总被引:2,自引:0,他引:2
本研究旨在利用16S rRNA基因克隆库技术分析广西富钟水牛瘤胃产甲烷菌组成及多样性。选取3头体况基本一致的健康雌性富钟水牛作为试验动物,采用机械破壁法提取瘤胃内容物总DNA,采用产甲烷菌引物Met86F/Met1340R扩增16S rRNA基因,构建16S rRNA基因克隆文库。结果表明,本试验共获得93个非嵌合体16S rRNA序列,按照97%的相似性划分为39个分类操作单元(OTU)。其中,60个序列(15个OTU)与已培养细菌16S rRNA序列相似性≥97%,占总序列的64.5%;32个序列(23个OTU)与已培养菌16S rRNA序列相似性处于90%<97%;仅有1个序列与Methanomassiliicoccus luminyensis相似性<90%。系统发育树分析表明,98.9%的序列均属于甲烷杆菌目(Methanobacteriales),部分序列与Methanobacteriales中任何已知相似序列都相隔较远,它们可能代表Methanobacteriales中新的属或种。由上述结果可见,富钟水牛瘤胃产甲烷菌以Methanobacteriales为优势菌群,其中有许多未知的产甲烷菌需进一步分离培养并对其功能进行分析。 相似文献
995.
本文旨在研究饲粮中添加葵花籽油和茶油对泌乳水牛生产性能及乳脂脂肪酸组成的影响。选取32头健康泌乳水牛(平均年龄为6.0岁,平均体重为620 kg),按产奶量(9 kg/d以上)、泌乳期(处于泌乳中期)相近原则随机分为4组,进行为期6周的饲养试验,其中预试期2周,正试期4周。基础饲料由精料和粗料组成。对照组饲喂基础饲粮;在试验组的精料中分别添加4%的葵花籽油(葵花籽油组)、4%的茶油(茶油组)、2%的葵花籽油+2%的茶油(混合组)。结果表明:与对照组相比,各试验组的产奶量均显著下降(P<0.05),乳脂率均显著提高(P<0.05),乳脂产量、乳蛋白率和乳糖率则无显著变化(P>0.05)。与对照组相比,葵花籽油组、茶油组和混合组的乳总固形物含量分别提高了5.22%、7.95%和6.17%,其中茶油组和混合组与对照组差异显著(P<0.05)。与对照组相比,葵花籽油组乳脂中cis9,trans11-C18∶2[共轭亚油酸(CLA)]的含量提高了44.54%(P<0.05),混合组乳脂中trans11-C18∶1的含量提高了22.68%(P<0.05)。葵花籽油组、混合组乳脂中C18∶2的含量均显著高于对照组(P<0.05);葵花籽油组、茶油组和混合组的多不饱和脂肪酸(PUFA)/饱和脂肪酸(SFA)均比对照组提高,且葵花籽油组和混合组显著高于对照组(P<0.05),其中混合组的PUFA/SFA最高。各组水牛的血液总胆固醇、甘油三酯、高密度脂蛋白、低密度脂蛋白、葡萄糖、总蛋白、尿素氮含量及谷丙转氨酶、谷草转氨酶活性差异不显著(P>0.05)。由此得出,泌乳水牛饲粮中添加精料饲喂量4%的葵花籽油、4%的茶油或2%的葵花籽油+2%的茶油合均可提高乳脂率和乳脂中CLA的含量,但会导致产奶量降低;优化乳脂脂肪酸组成上,以葵花籽油和茶油的混合添加效果较好。 相似文献
996.
KANG Jing-jing ZHAO De-ming TENG Ke-dao JIAO Xi-lan WANG Ping-li SUN Zhe NI Pei-pei WANG Zhi-feng ZHANG Rui YANG Yu-rong LIANG Hong-de 《农业科学学报》2014,13(4):858-869
Ulcerative colitis (UC) is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7 (MMP-7) and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium (DSS). The UC model was evaluated both by disease activity index (DAI) and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6 (IL-6) serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC (colorectal cancer). The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC. 相似文献
997.
Expression of stem cell factor in mast cells isolated from patients with chronic periapical diseases
AIM:To investigate the expression of stem cell factor (SCF) in tryptase -positive mast cells (MCs) in different types of human periapical diseases for determining the role of SCF and MCs in the pathogenesis of periapical diseases. METHODS:A total 50 cases of specimens were involved in this study, including healthy control (n=20), periapical cyst (n=15) and periapical granuloma (n=15). The tissue material was fixed in 10% formalin for at least 48 h, stained with hematoxylin and eosin for the observation of histopathology, stained with immunohistochemistry for identifying MCs and MCs degranulation, and stained with double immunofluorescence for identification of tryptase-SCF double positive MCs. RESULTS:Compared with healthy control, significantly higher densities of both total and degranulated MCs in human periapical lesions were observed. The densities of both total and degranulated MCs in the periapical cyst were significantly higher than that in the periapical granuloma. The density of tryptase-SCF double positive MCs in the periapical lesions was significantly higher than that in the healthy controls. The density oftryptase-SCF double positive MCs in the periapical cyst was significantly higher than that in periapical granuloma. No significant difference in the density of MCs between immunohistochemistry staining and double immunofluorescence staining was observed. CONCLUSION: The tryptase-SCF double positive MCs play an active role in the pathogenesis of the periapical inflammatory lesions, particularly in the formation of fibrous tissue in periapical cyst. The potential role of the tryptase-SCF double positive MCs relates with the initiation, development, and persistence of the periapical inflammatory process. 相似文献
998.
DAI Hong-liang HUANG Lei JIA Gui-zhi LIANG Chun-guang LI Xin QI Chun-ling 《园艺学报》2014,30(10):1902-1909
AIM:To explore the effect of L-carnitine on nuclear factor of activated T-cells,cytoplasmic 3 (NFATc3) in cardiomyocytes under H2O2 stimulation. METHODS:Primary cultured neonatal rat myocardial cells were stimulated by H2O2 at concentration of 200 μmol/L for 12 h to induce oxidative stress injury. In treatment group, L-carnitine and cyclosporin A (CsA), a specific inhibitor of calcineurin (CaN), were administered 30 min prior to H2O2 stimulation. After treatment, total, cytoplasmic and nuclear NFATc3 protein levels were determined by Western blotting. The method of immunofluoresence was used to evaluate the distribution of NFATc3. RESULTS:H2O2 treatment produced no effect on the expression of total NFATc3, but caused its translocation from the cytosolic to nuclear compartment, which was greatly blunted by L-carnitine pretreatment. CONCLUSION: L-carnitine antagonized oxidative stress injury via alleviating NFATc3 nuclear translocation. 相似文献
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