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     

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．     

β-t，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25％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15天实验饲料后再投喂15天对照饲料，整个饲养试验持续60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％～100．0％)，各处理间无显著差异(P＞0．05)。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＜0．01)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＜0．01)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＜0．01)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＞0．05)。60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14天内，对照组的累计死亡率显著高于(P＜0．01)β-葡聚糖实验组。攻毒后第14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得出如下结论：1)饲料中添加β-葡聚糖可以促进凡纳对虾生长并提高免疫力和抗病力；2)在本投饲策略下，全周期养殖期间投喂β-葡聚糖是安全的，不会产生免疫疲劳或其他副作用；3)从提高免疫力的角度，凡纳对虾饲料中β-葡聚糖制剂的添加量推荐为0．1％；若考虑促进生长，则添加量建议上升到0．2％。     

肽聚糖制剂对日本对虾非特异免疫因子的作用

用含不同浓度肽聚糖制剂的饵料投喂日本对虾 ,养殖 30d后取对虾血淋巴 ,分析血清中溶菌活力、凝集活力、酚氧化酶活力、超氧化物歧化酶活力、溶血活力。结果显示 :添加肽聚糖饵料组对虾比对照组对虾血清中的酚氧化酶活力、凝集活力均显著提高 (P <0 .0 5 ) ,高浓度肽聚糖饵料组 (1× 1 0 - 3)对虾血清溶血活力显著高于低浓度组及对照组中对虾的溶血活力 (P <0 .0 5 ) ;试验组与对照组中对虾的溶菌活力、总超氧化物歧化酶活力差异不明显 (P >0 0 5 )。表明饵料中使用一定浓度的肽聚糖可以通过提高对虾血清中酚氧化酶等因子活力而达到提高非特异免疫力的目的     

WSSV感染中国对虾肌肉与鳃膜蛋白变化及差异蛋白的鉴定

采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)、基质辅助激光解吸电离飞行时间质谱分析(MALDI-TOF/ MS)、生物信息学技术,研究了WSSV感染中国对虾后鳃膜蛋白和肌肉组织蛋白的变化.结果表明,WSSV感染中国对虾12h后,鳃膜蛋白27kD蛋白增强,至72h, 27kD蛋白增强显著.肌肉组织蛋白在感染48h后,出现1 条明显差异分子量为22kD的蛋白带.通过对该差异蛋白进行MALDI -TOF/ MS的肽质量指纹图谱及其生物信息分析,鉴定为钙离子结合蛋白,其在对虾抗病毒感染免疫中的功能值得关注.     

地衣芽孢杆菌De株的胞外产物对凡纳滨对虾脂肪酶活性影响的体外实验

为探析芽孢杆菌提高水产动物的消化酶活性的作用机制,在体外条件下实验研究了地衣芽孢杆菌(Bacillus licheniformis)De株的胞外产物(Extracellular products,ECP)对凡纳滨对虾(Litopenaeus vannamei)脂肪酶活性的影响.以半透膜法收集地衣芽孢杆菌De株的胞外产物,以匀浆离心法提取凡纳滨对虾成虾的肝胰腺和肠道消化酶,将胞外产物和对虾消化酶按体积比10:90混合,于体外条件下研究不同温度、pH及胞外产物添加量对样品脂肪酶活性的影响.结果显示,地衣芽孢杆菌胞外产物添加组的脂肪酶活性明显高于对照组(P＜0.05),在其最适的pH8～10下对虾肝胰腺和肠道的脂肪酶活性分别提高了118%和136.5%;而在其最适温度30℃～50℃时样品的脂肪酶活性则比两对照组分别提高了394.2%和195.1%.研究还发现,胞外产物添加组的脂肪酶活性与样品中胞外产物的添加量呈正相关.可见,在体外条件下地衣芽孢杆菌De株的胞外产物对凡纳滨对虾的脂肪酶活性具有促进作用.     

鲈鱼口服生物胶囊疫苗的研究

以暴发弧菌病的鲈鱼 (Lateolabraxjaponicus)鱼苗体内分离的 1株病原菌W 1(Vibrioanguillarum)为材料 ,分别以直接浸浴法、创伤后浸浴法和肌肉注射法人工感染鲈鱼鱼苗。结果表明 ,这三种感染方式均能使鲈鱼发病 ,其半致死浓度 (LD50 )分别为2 75× 10 7cfu/ml ,4 .68× 10 6cfu/ml和 3.72× 10 5cfu/尾。在此基础上 ,分别以福尔马林灭活法和喷雾干燥法制备了全细胞疫苗和微胶囊疫苗。将全细胞疫苗及微胶囊疫苗以直接拌入饵料法和卤虫携带法等两种方法口服免疫接种鲈鱼鱼苗 ,一周后以W 1活菌攻毒( 2 50× 10 6cfu/尾 )。结果表明 ,各免疫组一周的累积死亡率远低于两组对照组 ( 95% )。其中 ,以卤虫携带的生物微胶囊疫苗组的一周累积死亡率最低 ,为 2 5.0 % ;以卤虫携带的生物全细胞疫苗组的一周累积死亡率较高 ,为 60 .0 %。因而 ,以卤虫携带的生物胶囊疫苗组的免疫保护力最高 ,为 73.7% ,其次为微胶囊疫苗直接投喂组 ,保护力为 56.8%。直接投喂和卤虫携带法的全细胞疫苗也显示了一定的免疫效果 ,其免疫保护力分别为 52 .6%和 36.8%。     

饲料中维生素C和β-葡聚糖对牙鲆免疫力和抗病力的影响

以初始体重为(40.5±1.0)g的牙鲆幼鱼为实验对象,在室内水循环系统中进行了为期12周的饲喂实验,探讨了饲料中不同含量的维生素C和β-葡聚糖对牙鲆免疫力和抗病力的影响.结果表明,当不添加β-葡聚糖时,维生素C显著提高了牙鲆替代途径补体活力(ACH50)(P＜0.05),但维生素C对牙鲆溶菌酶、呼吸爆发活力、感染爱德华氏菌后开始死亡的时间和7d内的累积死亡率并没有显著影响(P＞0.05).当不添加维生素C时,牙鲆血清ACH50随着β-葡聚糖的添加而显著升高(P＜0.05);当饲料维生素C含量为1.0 mg/kg和495.0 mg/kg时,β-葡聚糖缺乏组的呼吸爆发活力显著低于添加β-葡聚糖实验组(P＜0.05);当饲料中维生素C含量为495.0 mg/kg和1980.0 mg/kg时,高水平的β-葡聚糖(0.6%)显著延缓了牙鲆感染爱德华氏菌后的死亡时间,并降低了感染细菌后7d内的累积死亡率(P＜0.05).以上结果对于牙鲆饲料中免疫增强剂的开发具有理论指导价值.     

明胶-酪蛋白酸钠可食性膜的包装性能研究

采用均匀实验设计方法,研究了明胶、酪蛋白酸钠、甘油添加量和成膜温度对可食性膜各项性能的影响,并确定了最佳的成膜工艺和影响膜各项性能的显著因素。结果表明,实验组C(明胶质量分数为5%,酪蛋白酸钠质量分数为8%,甘油添加比例为14%,成膜温度为55 ℃) 具有良好的包装性能,其拉伸强度为11. 45MPa,伸长率为28. 67%,透光率为92. 3%,雾度为7. 56%,氧气透过率为10. 101 cm3 / (m2 ·d·0. 1 MPa),水蒸气透过系数为1. 69×10-13 g·cm/ (Pa·s·cm2 );甘油添加比例是影响膜拉伸强度、伸长率和水蒸气透过系数最显著的因素,其相应的偏回归系数分别为-0. 901,2. 720 和0. 9662;明胶和酪蛋白酸钠均为影响膜透氧气率的显著因素,可增强膜的阻气性能。     

多壁碳纳米管对鲤鱼各组织SOD酶活性的影响

应用浸浴法研究多壁碳纳米管（MWCNTs）对鲤鱼（cyprinl Jscarpioio）腮、肝、肾和脑中超氧化物歧化酶（SOD）的影响,结果显示：低浓度（0．1,lmg·L^-1）处理组暴露后3d,腮和肝中的SOD活性显著高于对照组（p〈0．01）,肾和脑中SOD活性与对照组无显著差异（p〉0．05）。随着暴露时间延长,各组活性降低,至9d,肝和肾中SOD活性显著低于对照组（p〈0．05）,腮和脑中SOD活性与对照组无显著差异（p〉0．05）。高浓度（10mg·L^-1）处理组,整个暴露期间,肝中SOD的活性显著低于对照组（p〈0．01）,脑中SOD的活性与对照组无显著差异（p〉0．05）,腮和肾中SOD活性在暴露后3d,与对照组无显著差异（p〉0．05）,暴露后6d、9d,活性显著低于对照组（p〈0．05）。提示：MWCNTs对鲤鱼各组织中SOD酶活性的影响有时间和浓度依赖性。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.