Alternative indicator bacteria analyses for evaluating the sanitary condition of beef carcasses

Sponge samples were obtained from 47 (study 1) and 32 (study 2) beef carcasses in a small plant over 6 months. In study 2, slaughter equipment surfaces were also sampled. In study 1, the Petrifilm method was used to count presumptive Escherichia coli and spread plating on kanamycin esculin azide (KEA) agar with and without 40% added bile was used to count presumptive Enterococcus spp. Qualitative testing for presumptive E. coli and Enterococcus spp. in study 1 was done using lauryl sulfate tryptone broth (LST) + 4-methylumbelliferyl-beta-D-glucuronide (MUG) and KEA + 40% bile broth, respectively. In study 2, LST + MUG was used as a most probable number (MPN) method along with the Petrifilm method. In the two studies, 8 (17.0%) and 11 (34.4%) carcasses were contaminated with presumptive E. coli; all but one contaminated carcass contained <1 CFU/cm2. Presumptive Enterococcus spp. were recovered from 15 carcasses (31.9%) in study 1, but the KEA + 40% bile agar method lacked specificity (only 31.3% of isolates confirmed as Enterococcus spp.) The LST + MUG and Petrifilm methods were significantly (P < 0.05) related in terms of detecting presumptive E. coli, but the presence of presumptive Enterococcus spp. was not significantly related to the presence of presumptive E. coli. However, on slaughter plant equipment in Study 2 there was a statistically significant (P < 0.05) relationship between the presence of presumptive E. coli and presumptive Enterococcus spp. In study 2, there was no significant (P < 0.05) difference in numbers of presumptive E. coli (obtained using Petrifilm) on carcasses chilled 1 day (n = 16) and 7 days (n = 16), although more of the 7-day carcasses were contaminated (five and seven carcasses, respectively). For samples testing positive for presumptive E. coli, the 95% confidence intervals obtained using the LST + MUG MPN method included the Petrifilm value for all but one sample.     

Reverse transfection using antibodies against a cell surface antigen in mammalian adherent cell lines

Reverse transfection from a solid surface has the potential to deliver genes to various cells more efficiently than conventional methods. However, the effective gene delivery from a solid surface requires an optimized extracellular matrix (ECM) for the coating of glass slides, dependent on the nature of the cells. In a search for an appropriate substrate for the universal application to multiple types of cell, we focused on cell surface antigens and examined the effects of antibodies raised against them on gene transfer from an antibody-coated surface. We found that a coating of CD29-specific antibody allowed the most effective delivery of genes by reverse transfection in every type of cell that we examined. Our results suggest that reverse transfection with antibodies against CD29 might provide a universal tool for gene delivery and cell array-based analyses.     

减压条件下梨枣生理变化的研究

以梨枣为试材,研究枣果采后在减压条件下的生理变化。结果表明:梨枣属于非跃变型果实,并且减压贮藏在一定程度上降低了枣的呼吸强度;减压贮藏抑制了梨枣淀粉酶活性,降低了Vc的损耗,减缓了淀粉降解和糖的增加。试验表明,压力越低贮藏效果越好,以20.3kPa的贮藏效果最好。     

中性染色条件下羊毛保护剂的作用

将实验室合成的 2种抗定形保护剂 (BP - 1和BP - 2 )应用于纯羊毛织物的中性条件染色试验中 ,以商用抗定形保护剂MiralanHTP和交联型IrgasolHTWNEW作为对照 ,对染色后织物的永久定形、湿膨胀及拉伸性能进行了测试。结果表明 :保护剂BP - 1和BP - 2在中性条件下对羊毛纤维具有良好的保护作用 ,优于目前商用产品。     

不同保藏条件下猪油稳定性的研究

动物油脂含有多不饱和脂肪酸,很容易出现酸价升高[1]、哈败等品质下降的情况,生产企业也会采取各种方法来减少各种诱发因素,本篇文章就以猪油为例,通过正交和多因素控制实验,采用不同的保藏时间、保藏温度及添加抗氧化剂的方法,针对猪油的AV值和POV值的升高进行研究。研究中发现,其他条件相同时控制温度对控制猪油AV值和POV值的影响最大;控制O2对控制AV值的效果不大,对控制POV值的效果很大;36℃/O2促氧化条件下,添加抗氧化剂VE抑制AV升高的效果最好,VE、BHT、TBHQ抑制POV升高的效果最好。     

周期边值条件下Dirac算子的迹公式

对Dirac算子在周期边值条件下的特征值及其特征函数进行渐近估计,证明了特征值的秩和其作为ω(λ)的零点的重数一致,并获得了特征值的迹公式.     

Study on strength property of fabric under low-stress condition

A testing method for tensile under low-stress condition based on the characterization system of the handle properties of fabrics and yarns (CHS-FY) was introduced. The CHS-FY system measured weight, bending, as well as frictional and tensile behaviour by one pulling-out test. In addition, it characterized the tactile handle of fabrics and yarns. This article analyses tensile measurement of fabrics based on CHS-FY. The theoretical analysis and modeling to tensile were performed by structural analysis, and the corresponding formulae of tensile elastic constants (E ₁ and E ₂) before and after friction force involved were obtained. In addition, the tensile indexes were obtained through pulling-out force and distance curve in the CHS-FY tensile step, which include slope, work, linearity, and extension of tensile between sample and the surface of three-point beam structure. Comparisons and correlations of tensile indexes for theoretical and experimental results were conducted. Correlation coefficients between tensile elastic constants (E ₁ and E ₂) and (E ₃) measured by CHS-FY and KES-FB1 were found to be 0.857 and 0.870, respectively. The comparison of theoretical and experimental results indicate that the theoretical modeling of tensile is effective and accurate in measuring tensile indexes and the CHS-FY system can be utilized for characterizing the tensile properties of fabrics.     

Long-term subculture of human keratinocytes under an anoxic condition

The serial subculturing of human keratinocyte cells under the anoxic and normoxic conditions was examined. The cumulative number of population doublings in the subcultures under the former condition increased 2.1-fold while maintaining an appreciable growth rate of cells, as compared with that under the latter condition. Moreover, the migration ability, which was estimated by the rotation rate of paired cells, was maintained accompanied by fully developed filopodia of F-actin filaments under the anoxic condition, despite of the poor development of stress fibers at the center of the cellular body. The cells passaged under the anoxic condition possessed the sufficient clonogenic potential to form epithelial sheets, supporting the view that the long-term subculture of keratinocytes under the anoxic condition can be applied for cell expansion in the practical production of epithelial sheets.     

不停丝工况下的自动化铲板设计

针对纺丝箱内可进行铲板操作的空间有限且狭小的问题,提出铲板和排丝功能一体化的自动化铲板系统设计。应用滑环设计实现了排丝组件中居中旋转的吸丝漏斗和静止延伸的排丝管道的结构连接,从而保障排丝顺畅;将杠杆原理和弹簧串并联作用相结合,开展了铲板组件的缓冲结构设计,以实现悬臂偏置的铲刀和喷丝板面的有效贴合和刮铲,并应用ANSYS分析验证了该缓冲设计可保证刀刃与喷丝板面的接触力分布均匀;为避免铲刀抵触喷丝板面时的刚性冲击,对铲板组件的对刀运动进行力学建模,并计算得到铲板组件缓冲结构的具体参数设计值。最后开发不停丝工况下的自动化铲板模拟试验台,通过实验验证了自动化铲板系统的铲板和排丝功能一体化的结构设计的正确性和有效性。     

Functional reserves of humans in North condition and its providing of fat-soluble vitamins

It was been examined 810 healthy peoples inhabited in Russian European North. It was been shown that more than 35% of examined person from different group have lowered serum level of retinol and alpha-tocopherol. Described that alpha-tocopherol deficits occur more often and proposed that it cased as a result of free radical oxidation typical for North inhabitances.     

Acetylation of hydroxytyrosol enhances its transport across differentiated Caco-2 cell monolayers

Hydroxytyrosol and hydroxytyrosyl acetate are two well-known phenolic compounds with antioxidant properties that are present in virgin olive oil. Since the in vivo biological activity of polyphenols is dependent on their intestinal absorption and metabolism, the absorption of hydroxytyrosol and hydroxytyrosyl acetate and the extent to which they are conjugated and metabolised during transfer across intestinal Caco-2/TC7 cell monolayers, was investigated. LC-DAD and LC-MS were used for the quantification and identification of metabolites. Further evidence was obtained by observing metabolite susceptibility to β-glucuronidase treatment and by comparison of products of in vitro conjugation reactions of authentic phenolics with those produced by the CaCo-2 cells. Homovanillyl alcohol was the only conjugate detected as a result of hydroxytyrosol metabolism, and accounted for 20% of the total metabolites detected in the basolateral compartment after 2 h of incubation. Hydroxytyrosyl acetate was largely converted into free hydroxytyrosol (38.4%) and subsequently metabolised into homovanillyl alcohol (6.7%). In addition, hydroxytyrosyl acetate glucuronide (17.4%) together with non-metabolised hydroxytyrosyl acetate (37.5%) were also detected. Both hydroxytyrosyl acetate and hydroxytyrosol were transferred across human Caco-2/TC7 cell monolayers, but the acetylated compound exhibited an apparent permeability (Papp_AP→BL/Papp _BL→AP) 2.1-fold higher than free hydroxytyrosol. For both compounds, all conjugates were preferentially transported to the basolateral side. These results show that the acetylation of hydroxytyrosol significantly increases its transport across the small intestinal epithelial cell barrier, and supports further research into hydroxytyrosyl acetate as a hydroxytyrosol prodrug offering enhanced bioavailability.     

转基因小麦抗旱性鉴定及相关指标灰色关联度分析--测试文章

以9份转ABP9基因春小麦株系UC₄-1～UC₄-9及其受体亲本宁春4号为材料,在雨养和灌溉条件下,对这些材料的主要农艺性状和部分生化指标进行了测定,采用隶属函数值法和抗旱性度量（D）值法对其抗旱性进行了综合评价,并利用灰色关联度法对相关抗旱性状与抗旱指数之间的关联度进行了分析评价。结果表明：6份转基因小麦的抗旱性较受体亲本宁春4号增强,3份材料的抗旱性较非转基因春小麦品种定西35增强;各农艺性状和生化指标与抗旱指数的关联度从高到低依次分别为株高、单穗粒重、穗长、SOD活性、穗粒数、结实小穗数、有效分蘖数、POD活性、千粒重、脯氨酸含量、MDA含量。     

保护性耕作下小麦和豌豆投入产出能值分析--测试文章--测试文章

应用能值分析的基本理论和方法,探讨了传统耕作(T)、免耕(NT)、传统耕作+秸秆还田(TS)、免耕+秸秆覆盖(NTS)、传统耕作+地膜覆盖(TP)、免耕+地膜覆盖(NTP)等不同耕作模式下小麦和豌豆的投入产出能值,测算了其净能值产出率、能值投入率、宏观经济价值。结果表明：同一耕作方式下,种植小麦能值投入大于豌豆,豌豆能值产出是小麦的5倍以上,且豌豆宏观经济价值远远大于小麦;不同耕作方式下,两种作物净能值产出率均为免耕处理大于相应的耕作处理;由于传统耕作的三种模式人工和机械费用的投入远高于免耕三种模式,使得耕作处理下能值总投入大于相应的免耕处理;免耕+秸秆覆盖处理下,小麦和豌豆净能值产出率和宏观经济价值均达到最大,分别达到了0.64、3.93和9.26、53.1。说明免耕+秸秆覆盖不仅能够实现节约投入,而且可以增产增收,能够达到生态经济效益的最优。     

现代化啤酒厂设备管理工作的探讨

设备是技术工具,是手段,是实现现代化大生产必不可少的物质基础.设备管理工作是企业管理工作的重要组成部分.本文结合实际,阐述了在市场经济条件下啤酒厂进一步改进和加强设备管理工作,是提高设备综合效率,保证产品产量和质量,降低生产成本,确保安全生产,搞好环境保护,合理利用生产资金的重要内容.     

微波有机相法制备辛烯基琥珀酸淀粉的研究

研究了在微波条件下以辛烯基琥珀酸酐为酯化剂，在乙醇介质中对玉米淀粉进行改性制备辛烯基琥珀酸淀粉酯的工艺条件。着重讨论了乙醇、OSA、NaOH用量、淀粉含水量以及辐射时间对产物取代度的影响，并得到了最佳工艺条件。     

金属有限变形两种构形下本构模型研究

分别拟合出有限变形时物质描述和空间描述下的本构方程 ,在此基础上给出了基于物质描述和空间描述的有限元算法 .空间描述的有限元算法计算值同试验值符合得很好 ,说明用空间描述法能较好地描述金属大变形压缩的有限变形问题 .     

尼龙餐厨具在热氧条件下的老化行为研究

目的对尼龙餐厨具样品进行差示扫描量热(differential scanning calorimetry,DSC)原位热氧加速老化行为研究,分析老化温度和老化时间对样品熔点和热稳定性能的影响。方法采用傅立叶变换红外光谱法(Fourier transform infrared spectroscopy, FTIR)探究老化温度和老化时间与样品分子结构变化之间的关系。结果在模拟使用温度100～260℃范围内,随着DSC热氧老化温度的上升,样品的短期老化作用不明显。在模拟极限使用温度240℃条件下,样品的老化以氧化作用为主,且随热氧老化时间的延长,样品分子链的支化和断链程度加剧,同时伴随着交联现象,总体氧化稳定性变差。结论在极限使用温度240℃条件下,当热氧老化时间短于30min时,市售尼龙餐厨具具有良好的耐热氧稳定性,但若热氧老化时间在延长至60min以上时,其内在结构可能因热氧老化作用发生变化且产生酮等氧化产物,存在安全风险。     

Fc domain mediated self-association of an IgG1 monoclonal antibody under a low ionic strength condition

Recently, we reported that IgG1 monoclonal antibody A (MAb A) underwent liquid-liquid phase separation and separated into light and heavy phases under a low ionic strength condition. The liquid-liquid phase separation was induced due to self-association of MAb A in the heavy phase when the initial concentration of MAb A was between the two critical concentrations [Nishi et al., Pharm. Res., 27, 1348-1360 (2010)]. Here, we determined the interaction site of MAb A by using proteolytic Fab and Fc fragments of MAb A. The mean hydrodynamic diameter of the Fc fragment increased in a low ionic strength buffer, and furthermore the SPR measurement detected interactions of the Fc fragment with both whole MAb A and the Fc fragment, whereas the Fab fragment interacted with neither whole MAb A nor the Fc fragment. No binding was detected under an isotonic ionic strength condition. Zeta potential of MAb A was significant positive below pH 5.5 and negative above pH 6.5. Between pH 5.5 and 6.5 where the phase separation is significantly induced, MAb A had only a small positive or negative net charge. The isothermal titration calorimetry dilution method revealed that dissociation of MAb A accompanied endothermic heat changes, suggesting that intermolecular interactions among MAb A molecules were attributed to the enthalpically driven process. These results suggest that liquid-liquid phase separation of MAb A is mediated by a weak electrostatic intermolecular interaction among MAb A molecules mainly at Fc portions.