肽聚糖制剂提高凡纳对虾抗白斑综合征病毒感染力的研究

将肽聚糖制剂添加到普通对虾饲料中 ,制成分别含肽聚糖制剂 1%和 0 .1%的免疫饲料 ,按常规方法投喂凡纳对虾。 4周后测定每个实验组对虾的酚氧化酶、酸性磷酸酶和碱性磷酸酶活性 ,同时进行白斑综合征病毒 (WSSV)的人工投喂感染实验。实验结果显示 ,感染实验前投喂普通饲料组对虾和投喂免疫饲料组对虾的酚氧化酶和酸性磷酸酶活性无显著差别 (p >0 .0 5 ) ,各实验组对虾碱性磷酸酶活性的差异显著 (p <0 .0 5 ) ;感染实验后各实验组存活对虾的各项免疫酶活性无显著差异 (p >0 .0 5 )。凡纳对虾摄食添加了肽聚糖制剂的免疫饲料后 ,明显提高了对虾抵御WSSV感染的能力 ,其中尤其以添加了1%肽聚糖制剂的实验组的抗病毒感染能力最强 ,到实验结束时累计死亡率只有 10 % ,而对照组为 75 % ;1%添加量组与 0 .1%添加量组及对照组之间的累积死亡率差异显著 (p <0 .0 5 )。实验结果提示 :在对虾饲料中添加肽聚糖可提高对虾抗病毒感染能力 ,从而达到防病治病、增加生产收益的目的     

A3α-肽聚糖对凡纳滨对虾生长、免疫机能和抗病毒感染的影响

通过实验考察了A3α-肽聚糖（PG）制剂对养成期凡纳滨对虾的生长、免疫机能及抗白斑综合征病毒（WSSV）感染能力的影响。设立了连续投喂、间隔投喂和浸浴等6个实验组,分别在30d、60d和90d时,测定对虾的体长、体重、免疫机能和对虾的抗WSSV感染力。结果表明：30d时,连续投喂组对虾的体长和浸浴组及0．05％、0．1％PG连续投喂组对虾的体重较对照组有显著增长（P〈0．05）;0．05％、0．1％PG连续投喂组对虾体内的PO活性较对照组有显著提高（P〈0．05）;60d时,浸浴组及0．05％、0．1％PG连续投喂组对虾的体长、体重较对照组均有极显著增长（P〈0．01）,浸浴组、0．1％PG连续投喂组对虾血细胞吞噬活性显著增强（P〈0．05）,浸浴组及0．05％、0．1％PG连续投喂组对虾血浆上清液PO活性均有显著提高（P〈0．05）;90d时,浸浴组对虾的体长、体重较对照组均有极显著增长（P〈0．01）,间隔投喂组对虾血细胞吞噬活性显著增强（P〈0．05）,间隔投喂组血浆中的PO活性显著增高（P〈0．05）。各期感染实验均证明PG能增强对虾对WSSV的抗感染能力．     

原生药材微粉化制剂对药效作用的影响

采用超细粉碎技术对原生药材进行微粉化制成的糖泰胶囊和芩连胶囊 ,经动物实验证明 ,与传统粉碎技术制备的制剂比较可明显提高药效学活性     

氢等离子作用下Fe、Co对金刚石膜刻蚀的研究

金刚石具有很高的硬度,加工困难,为寻找一种刻蚀效率较高的材料,利用微波等离子体化学气相沉积（MPCVD）技术,在氢等离子体作用下,研究了Fe、Co对CVD金刚石膜表面的刻蚀效率。用SEM观察刻蚀效果,用Raman光谱对其表面结构进行表征。结果表明：在氢等离子体的作用下,Fe、Co对金刚石表面都有明显的腐蚀作用,其中Fe的刻蚀速率较高,并且可以通过对溶碳材料的厚度控制,来实现对刻蚀速率与刻蚀量的有效控制。对刻蚀后的样品用混合酸及丙酮处理后,得到了可与原始金刚石相媲美的质量。     

动态流变技术考察硅烷偶联剂对SSBR/SiO_2体系的作用

本文考察不同硅烷偶联剂对SSBR/Si O2混炼胶动态粘弹特性的影响,从动态流变学角度探讨偶联剂与Si O2及SSBR间的相互作用。讨论了混炼温度等因素对粒子表面改性效果及后续填料-基体相互作用的影响。通过对G'、G'应变依赖性、非线性弹的特征临界应变等参数的研究,细致揭示出硅烷偶联剂对填料-基体相互作用以及粒子分散的改善。     

香兰素对大豆分离蛋白膜抗菌作用的影响

对香兰素和香兰素添加到大豆分离蛋白膜后的抑茵效果进行研究.实验表明:香兰素有抑制大肠杆菌和金黄色葡萄球菌的作用.香兰素对受试茵的半数最低抑菌浓度(MIC50)分别是1500、2100mg/L.在押茵率和抑菌圈实验中,香兰素-大豆分离蛋白膜表现出一定的抑菌活性,MIC50分别是2500、3000mg/L,其略低于游离状态香兰素的活性.     

β-1,3/1,6-葡聚糖制剂对凡纳对虾生长及免疫力的影响

研究了从啤酒酵母泥悬液中提取的 β 1 ,3/ 1 ,6 葡聚糖制剂 (含 2 5 % β 1 ,3/ 1 ,6 葡聚糖 )对凡纳对虾生长及免疫力的影响。基础饲料中分别添加 3个水平 (0 1 % ,0 2 %和0 4 % )的 β 葡聚糖制剂配制成 3种实验饲料 ,以基础饲料作为对照组。实验饲料采取间隔投喂的策略 ,即每投喂 1 5天实验饲料后再投喂 1 5天对照饲料 ,整个饲养试验持续 6 0天。饲养试验结束后 ,无论是投喂 3种实验饲料还是对照饲料 ,对虾的成活率都很高(94 7%～ 1 0 0 0 % ) ,各处理间无显著差异 (P >0 0 5 )。然而 ,投喂 0 2 %或 0 4 % β 葡聚糖制剂的实验组的增重率显著高于 (P <0 0 1 )对照组 ;投喂 β 葡聚糖制剂的 3个实验组的饲料系数显著低于 (P <0 0 1 )对照组。此外 ,投喂 β 葡聚糖制剂的实验组 ,对虾血细胞酚氧化酶活性和吞噬活性都显著高于 (P <0 0 1 )对照组。无论是增重率还是免疫指标 ,投喂 β 葡聚糖制剂的 3个实验组彼此之间无显著差异 (P >0 0 5 )。 6 0天的饲养试验结束后 ,通过注射白斑杆状病毒 (WSSV)进行对虾攻毒试验。在攻毒后的 1 4天内 ,对照组的累计死亡率显著高于 (P <0 .0 1 ) β 葡聚糖实验组。攻毒后第 1 4天 ,3个 β 葡聚糖实验组的免疫保护力为 75 %～ 80 %。根据本研究结果可以     

CeO_2对Ti/RuO_2(0.5)-Co_3O_4(0.5)电极电催化性能的改进作用

为了改进Ti/RuO_2(0.5)-Co_3O_4(0.5)电极的析氧催化性能,采用热分解法在400℃下制备了稀土Ce改性Ti/RuO_2(0.5)-Co_3_O_4(0.5)氧化物电极,对稀土Ce掺杂量进行了优化.通过开路电压、循环伏安及极化曲线研究了电极在1.0 mol/L KOH溶液中的析氧催化活性.结果表明:稀土Ce掺杂可明显提高电极伏安电荷量、内外活性表面积及电极表面粗糙度,同时能降低析氧反应表观活化能;当其掺杂量为10:4时电极性能最佳,伏安电荷量和表面粗糙度分别高达806 mC/cm~2和3 047.83,析氧反应表观活化能低至15.74 kJ/mol.这主要是稀土Ce具有孔引发剂的作用,可提高活性氧化物晶粒的分散性,使电极活性表面积增加,改善了析氧催化活性.     

高矿化度油田卤水中pH值对20碳钢在硫酸盐还原菌作用下腐蚀行为的影响

目前对含硫酸盐还原菌(SRB)高矿化度下油气田卤水的腐蚀行为报道较少.采用挂片腐蚀试验和电化学试验法研究了20碳钢在含硫酸盐还原菌的不同pH值高矿化度油田卤水中的腐蚀规律,采用扫描电镜观察试样形貌.结果表明:20碳钢在pH值为5.5的含SRB腐蚀液中的腐蚀较pH值为7.5时严重,是不含SRB腐蚀液中的6倍多;pH值为7.5时,20碳钢表面微生物膜较厚,碳钢的腐蚀速率有所下降,致密的SRB生物膜的形成对溶液中Cl-的迁移起到了阻碍作用,碳钢的腐蚀得到了一定的抑制.     

组织质量特异性免疫建构要素一致性对质量绩效作用机制——基于PP法、fit法和层次回归分析的实证分析

为提升质量绩效,持续提升企业的竞争优势,以组织特异性免疫为切入点,构建了组织质量记忆等五个变量及五变量间以乘积形式表现的多纬一致性关系对质量绩效影响的理论框架,提取由五变量分别组合配置成的多纬一致性变量,使用PP法、fit法和层次回归分析法就构建的理论框架进行实证分析。结果表明:组织质量防御软要素、组织质量防御硬要素、组织质量外部监视、组织质量内部监视、组织质量记忆五个变量一致性可有效指导组织质量特异性免疫,进而提升质量绩效。五个变量之间的一致性形成一条影响质量绩效的链条。实证结论为提升质量绩效提供管理启示和可操作性建议。     

Effect of single-walled carbon nanotubes on primary immune cells in vitro

Carbon nanotubes (CNTs) are emerging as innovative tools in nanobiotechnology. However, their toxic effects on environment and health have become an issue of great concern. The effect of single-walled carbon nanotubes (SWCNTs) on primary immune cells in vitro was studied in this paper. The results indicated that SWCNTs (25 and 50 μg/mL) could promote the proliferation of spleen cells. However, they had no significant effect on the proliferation of spleen cells at concentrations of 1 and 10 μg/mL. They also had no effect on T-lymphocyte proliferation stimulated by concanavalinA (ConA) at lower concentrations. Moreover, they turned to inhibit T-lymphocyte proliferation at higher concentrations. It was found that SWCNTs inhibited the B-lymphocyte proliferation stimulated by lipopolysaccharides (LPS) at concentrations of 1, 10, 25 and 50 μg/mL. What is more, they significantly decreased the Natural Killer (NK) cell activity compared with the control group at all tested concentrations. The results suggest that SWCNTs have possibly negative effects on immune cells in vitro.     

基于多因素噪声模糊综合评价方法的研究及应用

以往的噪声评价是基于A声级进行的,缺乏对人的心理和除听力以外的其它生理因素的考虑。因此,文章在传统的噪声评价研究的基础上,建立具有创新意义的由听力损失、心率变异和脑波组成的多因素噪声模糊评价系统,进行噪声对人体负荷综合影响的评价。经过标准噪声人机实验的验证分析,得到结论：多因素的评价方法较传统方法更符合实际影响情况。     

质子交换膜燃料电池CCM的制备条件对其性能的影响

采用催化剂涂覆的膜(CCM)和碳纸扩散层组成质子交换膜燃料电池的膜电极.CCM采用直接喷涂的方法制备,研究了与直接喷涂技术相关的影响因素,包括催化层中Nafion的含量和分布、有机溶剂的种类、喷涂操作条件等.CCM的表面形貌和孔结构采用扫描电镜(SEM)方法表征,MEA的电化学特性通过单体PEMFC的I-V曲线进行评价.实验结果表明,在优化条件下制备的CCM膜电极的结构和性能有明显的改善.     

液氮冻制冰套法对水三相点温度的影响

介绍了液氮作为冷却剂在水三相点容器内冻制冰套的方法。利用该方法同时在两个不同真空度的水三相点容器内分别冻制冰套。通过实验，研究了此方法对所复现的水三相点温度的影响。实验结果表明：冻制过程中产生的应力以及开始生成的小冰晶引起水三相点温度偏低；并且，其对水三相点温度的影响随着水三相点容器内真空度的降低而增大。随着应力慢慢消除，小冰晶逐渐长大为大冰晶，所复现的水三相点值逐渐回升并趋于稳定。因此，为了高精度复现和准确测量水三相点，采用该冻制方法时，必须将冰套老化至少5天以后，才可以消除其对水三相点温度的影响。     

以酯端基PAMAM树形分子为模板在N，M-二甲基甲酰胺溶剂中制备金纳米粒子

用UV-vis、FT-IR光谱研究了HAuCl4和酯端基聚酰胺胺(PAMAM)树形分子在N，N-二甲基甲酰胺(DMF)溶剂中的相互作用，提出HAuCl4与树形分子之间的络合机理：[AuCl4]^-离子与质子化叔胺基团形成离子对，Au^3 离子与PAMAM树形分子上的酯基和酰胺基团形成配位作用。在DMF溶剂中酯端基PAMAM树形分子与HAuCl4配位后用柠檬酸钠还原形成金纳米粒子，UV-vis光谱和TEM图像分析表明了随树形分子代数的增加，金纳米粒子的直径减小，并提出了树形分子-金纳米复合物的结构模型：(1)较低代数的树形分子环绕在金粒子的外围；(2)在较高代数的树形分子空腔内部封装金纳米粒子。     

Effect of landfill leachate on cell cycle, micronucleus, and sister chromatid exchange in Triticum aestivum

With increasing use of municipal solid waste landfills for waste disposal, the leachate generated has become a serious environmental concern. Therefore, it is important to set up simple and accurate methods for monitoring leachate toxicity. In the present study, the physiological and genetic toxicity of the leachate, generated from Xingou Municipal Landfill in China, were investigated with Triticum aestivum (wheat) bioassay. The results indicate that the lower leachate concentrations stimulated the germination, growth and cell division, and did not induce obvious increase in micronucleus (MN) frequency in root tips; while the higher concentrations inhibited the processes, and significantly augmented the MN frequency in a concentration- and time-dependent manner. In addition, pycnotic cells (PNC) and sister chromatid exchange (SCE) occurred in root tips at all leachate concentrations tested, and the frequencies had positive relation with the treatment concentration and time. The results imply that components of leachate from the landfill may be genotoxic in plant cells, and exposure to leachate in the aquatic environment may pose a potential genotoxic risk to organisms. The results also suggest that the wheat bioassay is efficient, simple and reproducible in monitoring genotoxicity of the leachate.     

制备工艺对PMN-PNN-PZT四元系压电陶瓷结构和性能的影响

通过二次合成工艺制备了0.25 Pb(Mg1/3Nb2/3)O3-0.15Pb(Ni1/3Nb2/3)O3-zPbZrO3-wPbTiO3四元系压电陶瓷,其中w/z=1.6～1.65.研究了合成温度、烧结温度和极化等制备工艺对材料结构和性能的影响.结果表明:在合成温度为1050℃/860℃,烧结温度为1180℃,极化场强为5000V/mm时,材料具有良好的综合性能,其各项主要参数为:d33=(610～633)pC/N,Tc=234～235℃,εT33/ε0=3950～4015,Qm=81,Kp=0.63～0.66,tanδ=(1.7～2.0)%.     

Influence of the wastewater composition on denitrification and biological p-removal in the S-DN-P-process (b) Effect of acetate

The effect of acetate was examined during the p-removal and denitrification of wastewater. The plant was operated based on the sequencing-batch-biofilm-reactor (SBBR) process. As microbial media, ca. 9 mm Bio-Flow granules made from polyethylene and polypropylene were used. Three preparations were made to compare the level of biological p-removal and denitrification. In comparison to the batch test, 42 mg/L (AC 30) and 84 mg/L (AC 60) of NaCH(3)COO were mixed with the 500 mL of raw wastewater and the effect of the acetate concentration on the level of p-removal was monitored. All samples were immediately filtered with 0.45 microm membrane filter, and PO(4)-P, NO(3)-N, NO(2)-N and acetate were analyzed using Ion Chromatography, whereas P(total) and chemical oxygen demand (COD) were measured by a spectrophotometer. The p-removals for the WW, WW+AC 30 and WW+AC 60 preparations were found to be 9.4, 9.1 and 13.1mg/L, respectively. The WW+AC 30 preparation did not show any significant effect on the p-removal, while p-removal in WW+AC 60 preparation was higher than that in the other two preparations. A comparison of the data revealed the COD: NO(3)-N:AC:P ratio of the WW, WW+AC 30 and WW+AC 60 preparations to be 18.07:2.90:6.87:1, 21.28:2.45:5.98:1 and 15.95:2.75:6.18:1, respectively. The experimental results showed that approximately 7 mg/L of acetate was consumed per 1mg/L of p-removal.     

Effect of inorganic salts on the inhibition of hydrolyzing halo‐ester in a two‐phase solution

Abstract

Effect of the inorganic salts on the conversion of halo‐ester (ethyl‐2‐bromoisobutyrate, EtOBuBr) hydrolyzing in an alkaline aqueous solution/organic solvent two‐phase medium was investigated. The rate of hydrolyzing EtOBuBr and the conversion are obviously affected by the inorganic salts. The experimental data verify the proposed mechanism of hydrolysis. The reaction steps which hydrolyze these bromo‐alkyl bonds (Br‐C bond) and ester functional groups (–COOR) are developed and discussed. A kinetic model of the main reaction steps was established in which the rate expressions were derived. The intrinsic rate constants of the reactions were determined from the experimental data of EtOBuBr hydrolysis via parameter estimation. The results indicated that the conversion of hydrolyzing EtOBuBr is highly dependent on the concentration of alkaline compound in the aqueous solution. It is also found that sodium carbonate, sodium chloride, sodium nitrate and sodium sulfate inhibit the reaction, while calcium carbonate enhances it. The corresponding rate constants of hydrolyzing EtOBuBr in a variety of inorganic salt concentrations were searched.     

Effect of recycled content and rPET quality on the properties of PET bottles,part II: Migration

Polyethylene terephthalate (PET) bottles were produced from three types of recycled PET (rPET) with four levels of recycled content. The migration of substances from these bottles to water was studied. Several migrated substances were detected. The migrated amounts of acetaldehyde and ethylene glycol complied with the limits given in the food contact material (FCM) legislation. Migration of 2-methyl-1,3-dioxolane was below the limit of 10 μg·L⁻¹, which is conventionally applied for non-intentionally added substances (NIAS) not classified as ‘carcinogenic’, ‘mutagenic’ or ‘toxic to reproduction’ (CMR). Limonene, acetone, butanone and furan were also detected as migrants, of which limonene is a natural fragrant, and the other three are probably residues from solvents used to clean and protect the mould at the small-scale production facility. Finally, benzene and styrene were also found as migrants from rPET. These migrants appear to originate from heat-induced reactions within the PET matrix, which involve contaminants. The formation of benzene in rPET is attributed to polyvinylchloride as contaminant. The migrated amounts of benzene from the PET bottles with recycled content to the water simulant are relatively small (0.03–0.44 μg·L⁻¹) after 10 days at 40°C. Consequently, the margin of exposure is 3.10⁵–8.10⁶. Hence, the level of concern for the public health is low, and the migrated amount represents a low priority for risk management. The FCM legislation demands a risk assessment for migrating NIAS. Depending on the underlying data and exposure scenario, different threshold limits in the food can be derived which can still be considered as safe.