Connect Technique of Laminated Object Manufacturing Using Metallic Materials as Modeling Materials

To solve some key problems existed in the manufacturing of metallic functional part via Laminated Object Manufacturing (LOM), a new technique using vacuum solid-state pressure diffusion weld technique to connect the metallic slice sheets is presented in this paper. The following conclusions can be draw from the experiments introduced specially: the size in the stack direction shrink at the rate of less than 1% and the shrinking is owed to regularly error, the atom-diffusion between two combined interface occurred clearly and new crystallites shaped meanwhile, shearing intension of well connected diffusion section is more than 100 MPa and micro hardness of well-knit portion is the same to matrix's. It can be proved from the result above that the vacuum solid-state pressure diffusion technique weld is a perfect technique for connecting metallic slice sheets used in the manufacturing of metallic functional part via LOM.     

Aphakia in a German Holstein calf

Aphakia and further malformations of both eyes were diagnosed in a female German Holstein calf. Besides aphakia of the left eye, the calf exhibited microphthalmia, glaucoma and a hypoplastic uveoscleral tissue. Additional findings in the right eye were buphthalmus and glaucoma. Instead of aphakia, pathohistological and investigations revealed a very small (microphakia) and luxated lens. Neither the clinical nor the pathological examination revealed further malformations of other organs. A BVD infection could be excluded as cause for the ocular malformations observed. A deficiency or excess of vitamine A was unlikely because this would have also applied to all other calves born at the same time on the farm. An inbreeding coefficient of 3.168% for the malformed calf and the exclusion of environmental causes for these malformations of the eyes let us suppose a hereditary problem.     

糖水龙葵果罐头制作工艺研究

通过单因素多水平、多因素多水平的正交实验对龙葵果实罐藏工艺进行研究,结果表明,加工条件为烫漂温度60℃,烫漂时间10min,糖水浓度60%,排气温度40℃,排气时间15min.在此条件下罐头产品感官与品质最佳.     

动物溶菌酶基因的研究进展

溶菌酶[Lysozyme(EC3.2.1.17),LYZ]是机体先天免疫系统中一个重要的效应分子,参与机体多种免疫反应,在溶菌过程中形成一个水解体系,破坏和消除侵入动物体内的病原,从而实现机体的免疫防御。它可以有效抑制葡萄球菌、大肠杆菌等一系列病原菌,是重要的奶牛乳房炎抗性因子之一。本文综述了溶菌酶基因的研究进展,包括其结构与进化、变异及应用前景等。     

Arginine Levels Affect Growth and CSN3 Gene Expression of Dairy Cows Mammary Epithelial Cells in Vitro

本试验旨在研究培养基中添加不同浓度的精氨酸( Arg)对乳腺上皮细胞体外增殖及κ-酪蛋白(CSN3)基因表达的影响.选用中国荷斯坦奶牛乳腺上皮细胞进行体外培养,以无Arg的培养基(0.00 mg/L)为对照(0组),试验培养基分别添加69.50(0.25组)、139.00(0.50组)、278.00(1.00组)、556.00(2.00组)、1 112.00(4.00组)和2 224.00 mg/L(8.00组)的精氨酸.结果表明:Arg能促进乳腺上皮细胞的增殖,24 h时,0.25～4.00组与0组相比均差异显著(P＜0.05),8.00组与0组相比差异不显著(P＞0.05);48和72 h时,各试验组与0组相比均差异显著(P＜0.05).Arg能促进CSN3基因的表达,各试验组与0组相比均差异显著(P＜0.05),当Arg浓度为556.00 mg/L时,CSN3基因表达量最高.结果提示,Arg对乳腺上皮细胞增殖及CSN3基因表达均具有明显的促进作用,且在Arg浓度为69.50～1112.00 mg/L时促细胞增殖效果较佳,在Arg浓度为556.00 mg/L时促CSN3基因表达作用最强.     

CUE-MATE诱导新疆褐牛同期发情试验

[目的]为了探索新疆褐牛同期发情处理的有效时间段和最佳处理方法.[方法]采用CUE-MATE孕酮栓+PGF2α法进行新疆褐牛同期发情试验,[结果]表明:同期发情主要集中在取栓后的2 d,平均发情率为72.5%,情期受胎率为66.7%;3月的同期发情率显著高于5月和7月(P＜0.05),达到90.8%,但情期受胎率低于5月和7月,为61.0%,差异不显著(P＞0.05);母牛卵巢上以有黄体的同期发情率最高,达到95.3%,其次是有卵泡的,无黄体、卵泡的最低,三者差异显著(P＜0.05);有卵泡的情期受胎率略高于有黄体的,差异不显著(P＞0.05),无黄体、卵泡的同期发情率和受胎率都最低,差异显著(P＜0.05);育成牛的同期发情率略高于经产牛,为92%,差异不显著(P＞0.05);育成牛的情期受胎率显著高于经产牛(P＜0.05),为73.9%.[结论]环境温度、营养水平及母牛卵巢上有无黄体、卵泡影响发情率的高低,CUE-MATE孕酮栓+PGF2α法可用于诱导新疆褐牛的同期发情.     

辐照对冷却猪、鸡肉中细菌ATP发光强度的影响

采用ATP发光法检测辐照对冷却猪、鸡肉ATP发光强度的影响,并对其他试验因素是否对样品ATP发光强度产生影响进行了分析。结果表明:ATP标准品的浓度与发光强度呈显著的正相关,ATP标准品发光强度与辐照剂量表现为显著的负相关;辐照冷却肉的细菌ATP发光强度随辐照剂量的变化趋势呈现为倒"S"形特征,其中6.0kGy辐照时发光强度最大,4.0、8.0kGy剂量辐照时强度最小;无菌水、灭菌样品未对ATP发光强度造成干扰,而未辐照大肠杆菌浓度与ATP发光强度之间呈显著线性正相关,相关系数达到0.9437。     

A case of liver abscesses in a bull

During a farm visit a breeding bull was presented with signs of anorexia, somnolence, and loss of condition. These signs were chronic and slowly progressive. Clinical examination revealed an enlarged liver and subsequent ultrasonography revealed multiple abscesses in the liver. This was confirmed during post-mortem examination. Ultrasonography, proved to be of great diagnostic value, especially because it is a quick and non-invasive procedure.     

Left displacement of the abomasum in dairy cattle: recent developments in epidemiological and etiological aspects

The research with respect to displacement of the abomasum (DA) in dairy cattle is reviewed. Evaluated articles describe epidemiological and experimental studies. The occurrence is elevated with regard to breed, gender, age, concurrent diseases, environmental aspects and production levels as contributing factors and emphasis is placed on the effects of nutrition and metabolism. Reviewing the experimental work, distinction is made between the research into gas production in the abomasum and hypomotility of the abomasum, since both represent presumed pathways in the development of DA. Although the different fields of research have positive contributions to the understanding of the pathogenesis of DA, contradictions in the different studies are present. This is partly due to extrapolation of results from sheep to cows, or because of a low number of cows in the experiments. Finally, general suggestions are made for further research in the field of the pathogenesis of DA.