发酵构树饲料对断奶仔猪生长性能、养分表观消化率和血清生化指标的影响

本试验旨在研究饲粮中不同比例发酵构树饲料对断奶仔猪生长性能、养分表观消化率和血清生化指标的影响。试验选取35日龄、体重为(7.4±1.1)kg的健康断奶仔猪216头,随机分为Ⅰ(对照)、Ⅱ、Ⅲ、Ⅳ组,每组3个重复,每个重复18头仔猪。其中,Ⅰ组饲喂基础饲粮;Ⅱ组饲喂3%发酵构树饲料+97%基础饲粮;Ⅲ组饲喂6%发酵构树饲料+94%基础饲粮;Ⅳ组饲喂9%发酵构树饲料+91%基础饲粮。预试期5 d,正试期25 d。结果表明:1)与Ⅰ组相比,Ⅱ、Ⅲ、Ⅳ组断奶仔猪的腹泻率显著降低(P<0.05),各组间平均日采食量(ADFI)、平均日增重(ADG)和料重比(F/G)无显著差异(P>0.05)。2)与Ⅰ组相比,Ⅱ、Ⅲ、Ⅳ组粗蛋白质(CP)、粗脂肪(EE)、钙(Ca)和磷(P)表观消化率均显著降低(P<0.05)。3)Ⅲ组血清总胆固醇(TC)含量较Ⅰ、Ⅱ、Ⅳ组显著降低(P<0.05);各组间其他血清生化指标无显著差异(P>0.05)。4)各组间血清超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量及总抗氧化能力(T-AOC)无显著差异(P>0.05)。综上所述,饲粮中不同比例发酵构树饲料可以显著降低断奶仔猪的腹泻率,未对生长性能、血清生化指标和抗氧化指标产生不利影响,其中6%的替代比例效果最佳。     

电控燃油喷射发动机动态数据分析系统的研制

电控燃油喷射发动机的教学难点在于电子控制系统,其中关键在于信号的分析与测试。本文设计了可以直观显示电控发动机信号的"动态数据分析系统",将其电控核心装置ECU进行平面布置,制作成示教板,并将所有的控制线路与ECU相接,通过开关人为设置各种故障,通过诊断仪器来判断和排除故障,并举例说明了如何应用。系统便于教学实践,容易让学生接受。其设计方法和思路对于研制其他教学设备有一定的参考意义。     

不同籽粒颜色玉米自交系类胡萝卜素含量分析

采用高效液相色谱检测60个不同玉米籽粒颜色自交系中类胡萝卜素（叶黄素、玉米黄质、β-隐黄质和β-胡萝卜素）含量,结果显示,叶黄素、玉米黄质、β-隐黄质和β-胡萝卜素的平均含量分别为56.32、0.85、1.31和5.75mg/kg。按籽粒颜色由浅到深,将60个玉米自交系分为4个等级,颜色越深的品种类胡萝卜素含量越高。对R、G、B、Gray值与类胡萝卜素含量进行相关分析表明,R、G、B和Gray值之间存在极显著正相关（P<0.01）,相关系数分别为0.992（G与Gray）和0.939（R与Gray）,4种类胡萝卜素含量间呈极显著正相关,相关系数分别为0.830（β-隐黄质与β-胡萝卜素）和0.815（β-隐黄质与玉米黄质）。根据类胡萝卜素含量对60个玉米自交系进行聚类分析,60个自交系分为5类,其中第1类类胡萝卜素含量最低,第2类属于中富含类胡萝卜素的自交系,第5类属于高维生素A含量的自交系。综上可知,类胡萝卜素的种类及其含量是影响籽粒颜色的重要因素,可为培育高胡萝卜素含量的玉米品种提供依据。     

Changes of serum vascular endothelial growth factor levels in a rat model of acute myocardial infarction

AIM and METHODS: To study the changes of serum vascular endothelial growth factor (VEGF) levels in a rat model of acute myocardial infarction (MI) and its significance. Eighty-eight male Sprague-Dawley rats were used in this study. MI was produced by left coronary arterial ligation in 80 animals, and eight rats undergoing thoracotomy but not coronary ligation served as controls (sham).Blood samples were drawn from the right atrium before (sham animals) and 1, 3, 6, 12, 24 hours and 2, 3, 5, 7, 14 days after MI(n=8, respectively). Serum VEGF concentrations were measured by a sensitive enzyme-linked immunosorbent assay with a rabbit polyclonal antibody specific for VEGF. RESULTS: In 8 sham animals, the concentration of serum VEGF was (66.99±17.83) pg/mL. Six hours after MI, the level of serum VEGF significantly increased to (125.68±28.07)pg/mL (P＜0.01 vs sham control), and reached a peak (240.61±70.63 pg/mL, P＜0.01 vs sham control) at 24 hours after ligation and then decreased gradually over the remaining 2 weeks. But the level remained significantly elevated for 14 days (107.64±30.31 pg/mL, P＜0.01 vs sham control).CONCLUSION: Serum VEGF levels markedly and permanently increase in the rat model of acute MI may play an important role in the angiogenesis associated with MI     

保水剂对干旱胁迫条件下桉树燃烧性的影响

采用盆栽试验方法,以华南赤红壤为栽培基质种植桉树幼苗,研究了干旱胁迫下施用保水剂对桉树含水量、脱水速度和燃烧热的影响.结果表明:在干旱胁迫下,栽培基质中添加保水剂可有效提高桉树叶片的含水量、增大叶片的脱水速度、降低单位鲜重叶片的燃烧热,但对枝条和树皮的含水量、脱水速度以及单位鲜重的燃烧热没有显著影响;同时还初步说明.在干旱胁迫下保水剂用量为0.3%～0.5%时对桉树防御低强度火灾有利,但尚不能防御高强度火灾.     

Inhibition of desmoplakin expression induces connexin 43 remodeling in mouse HL-1 myocardial cells

AIM: To evaluate the content, distribution, and function of connexin 43 (Cx43) gap junctions in mouse HL-1 myocardial cells under the condition of desmoplakin (DSP) silencing.METHODS: The technique of RNA interference was used to inhibit the protein expression of DSP in HL-1 cells. The protein expression of DSP and Cx43 was analyzed by Western blotting and flow cytometry. The immunofluorescence staining was used to detect the distribution and co-localization of DSP and Cx43. The techniques of scrape loading and dye transfer were also used to determine the function of Cx43 gap junctions.RESULTS: Compared with non-treatment group and negative control group, the protein expression of DSP and Cx43 was reduced (P<0.05). Co-localization to the site of cell-cell contact was apparent in untreated and control conditions, but loss of DSP expression induced by siRNA-DSP correlated with a drastic redistribution of Cx43. Instead, Cx43 was found mostly within the intracellular space. The results of dye transfer assay indicated a significant decrease in the function of Cx43 gap junctions of the cells treated with siRNA-DSP.CONCLUSION: Inhibition of DSP expression induces redistribution of Cx43 and decrease in dye coupling between cells.     

Construction of lymphocyte subtracted cDNA library of unstable angina

AIM:To construct a subtracted cDNA library of differentially expressed genes in human unstable angina lymphocytes.METHODS:Suppression subtractive hybridizations (SSH) were performed between the patients with unstable angina pectoris and stable angina pectoris. Lymphocyte RNA, the obtained forward and reverse cDNA fragments were directly inserted into T/A cloning vector and transformed into E.coli JM 109 to construct a subtractive cDNA library. The inserting fragments were screened by blue and while blot screening and bacterium liqulid PCR.RESULTS:Each subtractive cDNA library contained more than 2000 positive bacteria clones. Most of them distributed between 200-600 bp inserts.CONCLUSION:The library is efficient and lays solid foundation for screening and cloning new and specific expressed genes in unstable angina lymphocyte RNA.     

Effects of diabetes on ischemic/reperfusion injury and cell apoptosis in rats myocardium via alterations in peroxynitrite

AIM: To determine the effects of different-term streptozotocin(STZ)-induced diabetes on ischemia/reperfusion (I/R) injury and cell apoptosis in rats myocardial via alterations in myocardial peroxynitrite.METHODS: The models of I/R injury were induced by occlusion and reperfusion of the left descending coronary artery (LDCA) in rats.I/R-induced infarct size was determined using triphenyltetrazolium chloride (TTC) staining.Quantified caspase-3 expression was used to represent apoptosis by Western blotting analysis.Peroxynitrite formation as indicated by nitrotyrosine level was measured by morphometric analysis.RESULTS: Two weeks after STZ treatment,infarct size (35.00%±3.00%) was smaller in 2 weeks diabetic hearts (2WKD) as compared with time-matched control group (2WKC) (51.00%±3.30%),whereas after 16 weeks of diabetes (16WKD),the infarct size (61.00%±3.00%) was bigger in the diabetic hearts as compared with the 16WKC group (50.00%±2.00%,P<0.05).After I/R,caspase-3 expression was lower in 2WKD+I/R group (A value：481±77) than that in 2WKC+I/R group (A value：1033±46),while caspase-3 was higher in the 16WKD+I/R group (A value：1206±78) than that in 16WKC+I/R group (A value：940±72,P<0.05).Nitrotyrosine was lower in 2WKD hearts (A value：211±13) than that in controls (A value：409±12),but was higher in 16WKD group (A value：506±37) compared with controls (A value：378±46,P<0.05).CONCLUSION: Short- and long-term STZ induced diabetes exerts opposite influences on myocardial I/R injury and cell apoptosis,and these contradictory influences may depend on different alterations in myocardial peroxynitrite.     

气相色谱法测定花生油掺假的研究

研究了采用气相色谱法测定叶种油脂甲酯化后的脂肪酸含量的方法，并用此方法测定了花生油掺入另一油脂后脂肪酸组砀 变化，从而确定以14∶0或16∶0含量来判断花生油中掺棕榈油的程度，以18∶3含量来确定掺菜籽油的多少。     

电控发动机不能起动的故障树最小割集分析

汽车电控发动机不能起动属于常见的故障现象,但同时也属于疑难故障问题.常规的故障诊断方式采取经验法,即根据诊断工程师的实际经验按故障现象的特征进行检测,并根据经验建立了相应的故障诊断因果关系图(也称故障诊断树).但实际操作的情况反映,故障诊断树的确立因人而异,从而检查的可靠性、快捷性受到限制.基于故障的原因分析,运用最小割集法设计了丰田卡罗拉1ZR-FE发动机不能起动的故障树,并运用层次分析法对卡罗拉发动机不能起动的故障树进行定性分析,确定各个底端事件的概率,改进故障诊断树的可靠性,并通过维修实例验证本文方法的正确性.本文方法具有一定的通用性,值得深入研究与探讨.