东北梅花鹿茸不同部位水解氨基酸含量的比较分析

对 10支东北梅花鹿茸作了不同部位水解氨基酸含量的比较分析 ,结果表明 ,水解氨基酸含量在东北梅花鹿茸腊片、粉片、血片和骨片各部位之间差异极显著 (P <0 0 1)。     

浅析农牧交错区特殊地位与生态环境建设难点

农牧交错区是国家实施西部大开发的重点区域,通过建国50多年的艰苦努力,已经成为一条经济产业带,生产了大量的煤炭、石油、天然气和农牧产品支持国家的经济建设,并对西部地区起着重要的吸引和辐射作用。通过野外调查和资料分析,按照典型剖析、专题研究、总结提高的基本思路,分析了农牧交错区在国家经济建设中的地位与作用,探讨了在西部大开发中生态环境建设面临的严峻挑战,进而提出了相应的发展对策。     

欧式木窗专用推台铣主轴动平衡方法研究

介绍了普及型欧式木窗专用推台铣床的作用及其特性，阐述了欧式木窗推台铣床主轴的平衡理论基础．指出了该机械系统的动平衡方法，并通过试验做出了分析。     

荒漠化能量与水平衡监测系统的应用

利用卫星遥感技术进行宏观监测是我国荒漠化监测的重要手段,它具有高效经济的特点。本文阐述了中荷合作项目中荒漠化能量与水平衡监测系统的技术方法及主要应用。     

低蛋白质氨基酸平衡饲粮对早期断奶仔猪腹泻和生产性能的影响

本研究选用１８头２８±１日龄断奶的杂交仔猪（平均体重约５．５ｋｇ），研究低蛋白质氨基酸平衡饲粮对早期断奶仔猪腹泻和生产性能的影响。试验结果显示：（１）低蛋白质氨基酸平衡饲粮使仔猪血浆挥发性盐基氨含量、血浆尿素氨含量和腹泻指数降低（Ｐ＜０．０５或０．０１）。（２）采食全植物蛋白型氨基酸平衡饲粮（ＣＰ１８．３％）的仔猪，其平均日增重（ＡＤＧ）、平均日采食量（ＡＤＦＩ）和料肉比（Ｐ／Ｇ）与采食复合蛋白型对照饲粮（ＣＰ１９．７％）的仔猪差异不显著（Ｐ＞０．０５），但前者的增重成本比后者降低（Ｐ＜０．０５）３１％。（３）采食复合蛋白型氨基酸平衡饲粮（ＣＰ１８．４％）的仔猪的生产性能优于采食复合蛋白型对照饲粮（ＣＰ１９．７％）的仔猪，前者的ＡＤＧ和ＡＤＦＩ分别提高（Ｐ＜０．０５）６１％和３２％，Ｆ／Ｇ和增重成本分别下降（Ｐ＜０．０５）２４％和３７％。（４）采食全植物蛋白型氨基酸平衡饲粮的仔猪，其ＡＤＧ和ＡＤＦＩ低于（Ｐ＜０．０１）采食复合蛋白型氨基酸平衡饲粮的仔猪。前者的Ｆ／Ｇ和增重成本趋于高于后者，但差异不显著（Ｐ＞０．０５）。以上结果表明，低蛋白质氨基酸平衡饲粮可显著降低仔猪断奶后腹泻和提高仔猪生产性能。复合蛋白型?     

赖氨酸修饰对梯棱羊肚菌黑色素结构和理化特性的影响

为了进一步提高梯棱羊肚菌黑色素的提取率及溶解性,本试验采用单因素、Plackett-Burman试验、响应面试验对纤维素酶-超声波协同提取梯棱羊肚菌黑色素的提取工艺进行优化研究。通过赖氨酸修饰,并对修饰前后的梯棱羊肚菌黑色素进行结构表征、理化性质及稳定性研究。结果表明,在NaOH浓度为1.54 mol/L,纤维素酶添加量为20 mg/g,纤维素酶酶解时间为78.6 min,料液比为1:30,酶解温度为40 ℃,超声时间为80 min条件下提取的梯棱羊肚菌黑色素最优。未修饰的梯棱羊肚菌黑色素不溶于水,色价值为480.24,修饰后的黑色素溶解度为1 016 g/L,色价值为1 771.18,比未修饰的黑色素在溶解性、色价值方面均有所提高。此外,在不同的温度、光照、pH条件下,修饰前后的梯棱羊肚菌黑色素均比较稳定。以上研究结果为梯棱羊肚菌黑色素的高效提取及其产品的开发利用奠定了理论基础。     

Acquired resistance triggered by elicitins in tobacco and other plants

Elicitins are a family of proteins excreted byPhytophthora spp. They exhibit high sequence homology but large net charge differences. They induce necrosis in tobacco plants which then become resistant to the tobacco pathogenPhytophthora parasitica var.nicotianae. In stem-treated plants, resistance was not restricted to the site of elicitin application, but could be demonstrated by petiole inoculation at all levels on the stem. Resistance was already maximum after two days and lasted for at least two weeks. It was effective not only towardsP. p. var.nicotianae infection, but also against the unrelated pathogenSclerotinia sclerotiorum. In contrast to dichloroisonicotinic acid, an artificial inducer of systemic acquired resistance, which was increasingly effective with doses ranging from 0.25 to 5mole per plant, the basic elicitin cryptogein exhibited a threshold effect, inducing near total resistance and extensive leaf necrosis above 0.1 nmole per plant. Between 1 and 5 nmole, acidic elicitins (capsicein and parasiticein) protected tobacco plants with hardly any necrotic symptom. Elicitins exhibited similar effects in various tobacco cultivars andNicotiana species, although with quantitative differences, but induced neither necrosis nor protection in other SolanaceÆ (tomato, petunia and pepper). Among 24 additional species tested belonging to 18 botanical families, only some BrassicaceÆ, noticeably rape, exhibited symptoms in response to elicitins, in a cultivar-specific manner. Elicitins appear to be natural specific triggers for systemic acquired resistance and provide a tool for unraveling the mechanisms leading to its establishment.Abbreviations AR acquired resistance - HR hypersensitive response - INA 2,6-dichloroisonicotinic acid - Ppn Phytophthora parasitica var.nicotianae - SAR systemic acquired resistance     

In vitro expression and inhibition of procoagulant activity produced by bovine alveolar macrophages and peripheral blood cells

Local and systemic activation of coagulation is frequently associated with bacterial sepsis. The coagulopathy is due, at least in part, to expression of tissue factor (TF) by monocytes and macrophages. The purpose of this study was to evaluate the expression of procoagulant activity by bovine alveolar macrophages, leukocytes and platelets, and to determine the relative potency of three chemical inhibitors of TF expression (pentoxifylline, retinoic acid, and cyclosporin A). Bovine alveolar macrophages were stimulated with lipopolysaccharide (LPS) derived from Pasteurella haemolytica or recombinant bovine tumour nervous factor (TNF) and dose- and time-dependent effects on TF expression were studied. LPS and TNF induced TF expression in alveolar macrophages and LPS treatment of whole blood induced TF expression in mononuclear cells. Neutrophils and platelets also expressed procoagulant activity, but this activity was not inhibited by anti-bovine TF monoclonal antibody. Pentoxifylline (40 mol/L), retinoic acid (0.01 mmol/L) and cyclosporin A (0.08 mol/L) inhibited TF expression when added concurrently with LPS or TNF, but not when added 4 h after stimulation. TF mRNA was not detected in unstimulated alveolar macrophages by Northern blot analysis. In contrast, exposure to LPS or TNF for 6 h induced marked expression of TF mRNA, which was inhibited by treatment with pentoxifylline, retinoic acid and cyclosporin A. Expression of TNF by alveolar macrophages stimulated with LPS was also inhibited by these compounds. Our results indicate that procoagulant activity expressed by alveolar macrophages and monocytes is associated with expression of TF, whereas procoagulant activity expressed by neutrophils and platelets is not. The concentrations of pentoxifylline and retinoic acid necessary for inhibition of TF expression in vitro may not be achievable in vivo owing to their toxic effects. However, the in vitro concentration of cyclosporin A that inhibited TF expression did not exceed the plasma concentration observed in humans, and therefore may be useful for inhibition of TF expression in vivo.Abbreviations BAL bronchoalveolar lavage - LPS lipopolysaccharide - cDNA cloned deoxyribonucleic acid - cAMP cyclic adenosine monophosphate - GAPDH glyceraldehyde phosphate dehydrogenase - mRNA messenger ribonucleic acid - TF tissue factor - TNF tumour necrosis factor - DPBS Dulbecco's phosphate-buffered saline