热处理对轻度加工葡萄膜脂过氧化作用的影响

为探索热处理对轻度加工葡萄衰老软化及贮藏保鲜效果的影响，以红地球葡萄为试验材料,研究了50℃ 10 min、50℃ 15 min、 55℃ 5 min、55℃ 10 min热空气处理对其衰老过程中膜脂过氧化作用及贮藏效果的影响。结果表明，55℃ 5 min和10 min处理与对照相比，能抑制过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)活性的下降，降低丙二醛(MDA)含量的积累和果肉组织的相对电导率，从而抑制轻度加工葡萄的衰老软化。而50℃ 10 min和15 min热处理对延缓轻度加工葡萄衰老软化无明显作用。     

有机生活垃圾半干发酵菌群的分布变化特征

为了研究有机生活垃圾厌氧发酵中菌群的分布变化特征,以有机生活垃圾为生物质资源,进行半干式厌氧发酵试验。采用最大或然数法(most probable number,MPN)分析发酵过程中厌氧菌群时间和空间上的数量变化。结果表明:厌氧菌中产酸菌先于氨化菌达到最大值并占据优势地位,产甲烷菌在启动阶段初期基本没有增殖,第25天左右达到最大值3.2×109个/m L,随后产甲烷菌在整个盛产期数量维持在这一数量级上。厌氧纤维素降解菌菌数呈现缓慢增长的趋势,直到投料的第45天才增加到106个/m L。空间上厌氧产酸菌和甲烷菌的数量均是在基质条件稳定的中部位置和流动性较好的底部位置较多;厌氧氨化菌数量较多的为中部边缘和中部中心位置;厌氧纤维素降解菌主要在底部增殖。初步构建了产酸菌与产甲烷菌时间和空间的动力学模型,模型拟合效果良好,可为厌氧发酵工艺提供参考。该文对有机垃圾制取生物燃气的工艺过程具有理论指导意义。     

Comparison of HPLC methods for determination of anthocyanins and anthocyanidins in bilberry extracts

An HPLC method and an acid hydrolysis HPLC method for the analysis of anthocyanins and anthocyanidins in bilberry extracts have been developed. The HPLC method coupled with a mass detector has identified 11 anthocyanins in bilberry extracts. The method provides anthocyanin profiles that are very useful in verifying the identity of botanical raw materials, monitoring the consistency of the raw material source, and quantitating the total anthocyanins. The acid hydrolysis HPLC method greatly simplifies the anthocyanin profile in bilberry samples and converts anthocyanins to five major anthocyanidin aglycones: delphinidin, cyanidin, petunidin, peonidin, and malvidin. Each of these aglycones can be separated completely and quantitated accurately with external standards. Various extraction and hydrolysis conditions were investigated, and the advantages and disadvantages of the HPLC and acid hydrolysis methods are discussed.     

Early pregnancy diagnoses based on physiological indexes of dairy cattle: a review

Tropical Animal Health and Production - With the development of standardization and scaling in the dairy farming industry, timely and accurate pregnancy diagnosis is required to improve the...     

片状农业物料完全组分利用滚筒干燥控制技术研究

针对实际干燥过程的非线性、变参数以及环境干扰等建模和控制问题,采用模糊控制理论建立了能够反映控制信号与温度偏差、变化关系的温度控制的系统模型,将模糊控制方法引入到片状农业物料滚筒干燥工艺过程中,提出并自行设计了完全组分利用滚筒干燥装置.为验证模璎和控制器设计的有效性,进行了滚筒干燥控制模璎的仿真研究,并与传统的PID控制方法进行比较.结果表明:模糊控制方法用于滚筒干燥过程是可行的,显示出智能控制方法的优势,改善了控制系统性能,更好地满足了滚筒干燥控制要求.     

Expression analysis of the type I keratin protein keratin 33A in goat coat hair

The coat of a goat, like that of many mammalian species, consists of an outer coat of coarse hairs and an under coat of fine, downy hairs. The coarse guard hairs are produced by primary follicles and the finer cashmere hairs by secondary follicles. We previously reported that hair keratins are components of cashmere hair, and proteomic analysis revealed that their expression is elevated in winter coat hair. To determine detailed characterization, we have cloned keratin 33A gene, a major highly expressed keratin in winter, and then analyzed the expression of goat hair coat. By Western analysis, we detected that keratin 33A protein is expressed only in hair coat among the various goat tissues. Moreover, the expression level in winter has increased in cashmere high‐producing Korean native breed, whereas the expression levels between summer and winter had not changed in cashmere low‐producing Saanen. In addition, by immunohistochemistry we determined that keratin 33A is localized in the major cortex portion of cashmere fiber. These results confirm that keratin 33A is a structural protein of goat cashmere hair fiber.     

Pharmacokinetic analysis of plasma concentration and urinary excretion of sulphamonomethoxine and its metabolite in Goettingen minipigs

The plasma concentration and renal excretion after a bolus intravenous injection of a low (10 mg/kg) or high (100 mg/kg) dose of sulphamonomethoxine (SMM) were studied in five Goettingen minipigs. The time data of plasma concentration after a low dose decreased rapidly and appeared to be linear on semilog graph paper. On the other hand, a decrease in the plasma concentration after a high dose was slow at first, gradually accelerated, then became rapid, showing that SMM disposition after a high dose (100 mg/kg) seemed to be non-linear with capacity-limited elimination. A large amount of the acetyl derivative of SMM (AcSMM), which was determined to be the main excretory product of SMM in urine, was detected in the plasma after SMM injection. As the ratios of the area under plasma concentration-time curve of AcSMM to that of SMM were not significantly different at either dose, the acetylation of SMM may be unsaturable by injection of 100 mg/kg of SMM. Immediately after the injection of a low dose, a rapid hyperbolic increase of the fraction of the cumulative amount of the excretory products in urine was observed. On the other hand, the fraction curve at the high dose rose slowly at first, then rapidly and hyperbolically. These results suggested that the non-linear drug disposition after a high dose (100 mg/kg) of SMM in pigs may be the result of a limited capacity for renal excretion of SMM and excretory products, especially the acetyl derivative.     

按限定温降值和温降时间确定储罐保温层厚度

在储存油品的容器内,油品的温度随储存时间的增加而逐渐降低,因而油品的这种温降与时间、传热等有一定的关系。为满足运行要求,在油品的储存与运输中,有时需要将其温降限定在一定的范围内。以立式拱顶储罐为例,根据限定的温降值和限定的温降时间,建立了确定储油容器保温层厚度的计算公式。在已知保温层厚度的情况下,这些公式还可用于确定一定时间内的油品温降值,或者确定油温从初始温度降低到允许值所需要的时间。     

Evaluation of the transmission risk of foot-and-mouth disease in Japan

The transmission risk of foot-and-mouth disease (FMD) in Japan was evaluated using a mathematical FMD transmission model. The distance-based transmission rate between farms, which was parameterized using the FMD epidemic data in 2010 in Japan, was used to calculate the local-level reproduction numbers—expected numbers of secondary infections caused by one infected farm—for all cattle and pig farms in the country, which were then visualized as a risk map. The risk map demonstrated the spatial heterogeneity of transmission risk in the country and identified risk areas with higher possibility of disease spread. This result suggests that, particularly in high-risk areas, it is important to prepare for the smooth and efficient implementation of control measures against FMD outbreaks.     

伞齿轮冷闭塞锻造成形过程数值仿真

采用冷闭塞锻造技术生产汽车伞齿轮具有节材、节能、低成本、高效率的显著优点，而且齿轮机械性能好、使用寿命高。采用DEFORM软件对捷达轿车差速器伴齿轮冷闭塞锻造成形过程进行了计算机仿真。模拟工艺试验表明，冷闭塞锻造工艺与模具设计合理，数值模拟分析准确，对轿车差速器伞齿轮冷塞锻造技术的工程应用具有重要意义。