Gap junction blockage promotes cadmium-induced apoptosis in BRL 3A derived from Buffalo rat liver cells

Gap junctions mediate direct communication between cells; however, toxicological cascade triggered by nonessential metals can abrogate cellular signaling mediated by gap junctions. Although cadmium (Cd) is known to induce apoptosis in organs and tissues, the mechanisms that underlie gap junction activity in Cd-induced apoptosis in BRL 3A rat liver cells has yet to be established. In this study, we showed that Cd treatment decreased the cell index (a measure of cellular electrical impedance) in BRL 3A cells. Mechanistically, we found that Cd exposure decreased expression of connexin 43 (Cx43), increased expression of p-Cx43 and elevated intracellular free Ca²⁺ concentration, corresponding to a decrease in gap junctional intercellular communication. Gap junction blockage pretreatment with 18β-glycyrrhizic acid (GA) promoted Cd-induced apoptosis, involving changes in expression of Bax, Bcl-2, caspase-3 and the mitochondrial transmembrane electrical potential (Δψm). Additionally, GA was found to enhance ERK and p38 activation during Cd-induced activation of mitogen-activated protein kinases, but had no significant effect on JNK activation. Our results indicated the apoptosis-related proteins and the ERK and p38 signaling pathways may participate in gap junction blockage promoting Cd-induced apoptosis in BRL 3A cells.     

In Vitro Assessment of Probiotic Potential of Lactobacillus acidophilus and Antagonistic Activity Against Escherichia coli O157:H7

The antagonistic activity of Lactobacillus acidophilus KLDS1.0901, KLDS1.0902, KLDS1.1003 and NCFM against Escherichia coli O157: H7 were investigated in this study. The culture supernatants of all the L. acidophilus stains showed high bacteriostatic activities against E. coli O157: H7 and the bacteriostatic substances of their Cell-Free Supernatants (CFS) were preliminarily determined from organic acids. The bacteriostatic activity from CFS or viable L. acidophilus against E. coli O157: H7 was also assessed by using co-incubation methods, CFS had high bactericidal activity against E. coli O157: H7, no viable E. coli O157: H7 was detected when 5×107 cfu of E. coli O157: H7 was added to 5 mL of CFS and incubated at 37℃ for 2 h. However, L. acidophilus themselves had no bacteriostatic activity after directly contacted with E. coli O157: H7. The inhibition E. coli O157: H7 adhesion and colonization of L. acidophilus were also investigated based on competition, exclusion and displacement assays. L. acidophilus KLDS1.0901, KLDS1.1003 and NCFM strains were effective to displace E. coli O157: H7 from a Caco-2 cell layer in competition and exclusion assays. However, in displacement assay, all of the strains showed no significant antagonistic activities. Meanwhile, the probiotic potential of L. acidophilus strains was investigated based on adhesion assay to Caco-2 cells and anti-inflammatory effects by IL-8 produced in Caco-2 cells. The adhesion ability and anti-inflammatory effects of L. acidophilus strains showed a strain-dependent manner. In general,L. acidophilus KLDS1.0901 and NCFM showed better probiotic potential than KLDS1.0902 and KLDS1.1003. Thus, the use of L. acidophilus KLDS1.0901 and NCFM to prevent or treat of diseases associated induced E. coli O157: H7 in vivo was suggested.     

乳酸菌对苜蓿草粉发酵品质的影响

通过为期60d的发酵,探讨添加乳酸菌对苜蓿(Medicago sativa)草粉发酵品质的影响。试验设4个处理,分别为添加无菌水(对照)、植物乳杆菌(Lactobacillus plantarum,LP)、屎肠球菌(Enterococcus faecium,EF)和植物乳杆菌+屎肠球菌(LP+EF)发酵苜蓿草粉,设5个时间点采样进行相关项目测定。结果表明,与对照组相比,发酵60d时各试验组发酵苜蓿草粉的评分提高,总酸含量显著升高(P0.05),pH显著降低;LP、LP+EF和对照组的干物质含量明显低于EF组;各试验组酸性洗涤纤维含量明显低于对照组;有氧暴露7d后,各试验组的pH均显著低于对照组、总酸含量均显著高于对照组(P0.05),且只有对照组中检测到酵母菌(Saccharomycetes)和霉菌(Mycete)。综上可知,添加乳酸菌对苜蓿草粉的发酵品质、稳定性及营养组成具有良好的改善作用。     

新型纳米PE膜对温室环境因子的影响

[目的]检测新型纳米流滴控释膜的流滴性能及其对温室环境因子的影响。[方法]通过设施叶菜类农业大棚智能监控系统，对流滴控释膜和对照膜内的空气温度、光照强度和CO2浓度等进行检测和分析。[结果]通过大田扣棚跟踪监测数据发现，这种膜具有比现有长寿、流滴功能膜光照强度高、减少高温天气棚温上升以及具有更好的光合作用效果等优点。[结论]这种新型的纳米流滴控释膜比现在广泛使用的国产流滴膜性能更优越，应用前景广泛。     

辽宁绒山羊育肥羔羊的羊肉营养特性研究

选择24只年龄90日龄±3.5日龄、体重15.00 kg±0.62 kg的辽宁绒山羊羔羊,公母各半.试验分3组,Ⅰ组为高能低蛋白组,Ⅱ组为高能高蛋白组,Ⅲ组为对照组,分别饲喂1号、2号和3号日粮.研究育肥羔羊肉常规营养成分、各类脂肪酸和氨基酸含量.结果表明:按冻干肉样为基础测得试验Ⅱ组粗脂肪极显著(P＜0.01)高于试验Ⅰ组和对照组;按鲜样基础测得试验Ⅱ组粗脂肪极显著(P＜0.01)高于对照组,试验Ⅰ组显著(P＜0.05)高于对照组.在脂肪酸方面,总体上两试验组均高于对照组,其中试验Ⅱ组又高于试验Ⅰ组.试验Ⅱ组C14∶0、C16∶1、C18∶0含量显著(P＜0.05)高于对照组,试验Ⅱ组C15∶0、C16∶0、C18∶1n9c含量极显著(P＜0.01)高于对照组.根据脂肪酸饱和度分类统计,试验Ⅱ组SFA、PUFA、n-3 PUFA、CLA均显著(P＜0.05)高于试验Ⅰ组和对照组;试验Ⅰ组n-3 PUFA又显著(P＜0.05)高于对照组.在氨基酸方面除蛋氨酸外,对照组总体上均高于两试验组.应用人理想氨基酸模型评分发现,试验Ⅱ组为85.37分,高于试验Ⅰ组和对照组;而试验Ⅱ组的E/T值和E/N值分别为0.51和0.90,均高于对照组.因此,高能高蛋白日粮育肥羔羊可使羊肉粗脂肪和多不饱和脂肪酸显著增加,总脂肪酸极显著增加;而单独提高日粮代谢能水平也使育肥羔羊肉粗脂肪含量、MUFA和脂肪酸含量增加,同时对羊肉氨基酸构成和必需氨基酸比例有较大改善作用.     

园林植物景观空间的构成与特征初探

指出了植物与地形、建筑等园林要素一样,具有构成空间、分隔空间及引导空间变化的作用。植物景观空间主要由形态要素和植物要素构成,形态要素从地面、立面和顶面以及三个因素的不同组合方式形成各种不同的环境空间,而植物的形态、色彩、质地、气味、季相变化以及文化内涵等要素则从相关方面丰富了植物空间的景观效果。与建筑空间相比,植物构筑的空间具有独特的空间特征。     

Simulation and experiment of damage evolution on composite structure in hydro/thermal/mechanical coupled environment

By means of the introduction of the classic laminate theory with considering hygrothermal effect into the finite element method, by measuring the hygrothermal expansion coefficient, and introducing the damage criterion of composite structure, simulated the process of the composites mechanical properties damaging in hygrothermal environment. The composites panel absorption were studied on in the 70 °C/85 %RH and 80 °C/85 %RH hygrothermal environment, and the compressive experiment were carried on in RT and hygrothermal environment. The results of experiment and simulation were contrasted and analyzed, and they were better fitted.     

温度对皱纹盘鲍摄食和耗氧率的影响

为了测定皱纹盘鲍(Haliotis discus hannai Ino)在不同温度下摄食和耗氧率的变化,设计了室内控温实验。以7~8月龄（壳长2.67±0.02 cm）和19~20月龄（壳长6.91±0.04 cm）两组皱纹盘鲍为实验对象,分别在5个温度梯度(5℃、10℃、15℃、20℃、25℃)下饲育30天,并记录鲍的摄食率和耗氧率。结果表明,7~8月龄鲍的摄食率和耗氧率显著高于19~20月龄鲍(P<0.05);鲍的摄食率和耗氧率均随水温的升高而增加,并在20℃二者均达到最高值,当温度超过20℃时,二者随温度的升高而减少。19~20月龄鲍5℃和10℃组的摄食率和耗氧率与20℃组差异极显著(P<0.01),15℃和25℃组与20℃组差异显著(P<0.05);7~8月龄鲍20℃组的摄食率与其他温度差异显著(P<0.05),而20℃的耗氧率和15℃、25℃差异不显著(P>0.05);相关性分析显示,摄食率和耗氧率与温度间符合三次函数关系。该实验发现,皱纹盘鲍的摄食和耗氧率受温度变化的影响显著,适宜温度在20℃左右,这对进一步研究鲍合理健康养殖具有重要意义。     

离子束介导外源全DNA转化拟南芥菜的诱变效应

用 30kev的Ar+ 离子 ,以 1.5× 10 17ions/cm2 的注入剂量分别介导外源拟南芥菜 (Lansberg生态型 )、甘蓝、红甜菜和芦荟的全DNA转化拟南芥菜种子 (Columbia生态型 )。转化当代营养期表型变异率与外源供体和转化受体的亲缘远近没有必然的联系 ,而低育性株率却随着外源供体亲缘关系的从近到远 ,呈现一种从低到高再变低的变化趋势。从低育性株后代中选育出 2个稳定的突变体 ,该突变体不但保持了其亲本的低育性 ,而且其他性状也有较显著的变异 ,如株型、叶型等。     

杉木落针病病原菌生物学特性及药剂防治研究

定点观察表明，３月中旬旬平均气温达８．１℃时，杉木落针病病菌赵冬子囊盘开始释放子囊孢子。４月份旬平均气温为１６．６－２０．１℃，病叶上子囊盘的数量急剧增加。病菌菌丝体在ＰＤＡ，蛋白胨蔗糖和杉木叶剪汁蔗糖培养基上生长良好，生长最适温度２０℃，最适ｐＨ为５．０。