Employment of Phenolic Compounds from Olive Vegetation Water in Broiler Chickens: Effects on Gut Microbiota and on the Shelf Life of Breast Fillets

Olive vegetation water (OVW) is a by-product with a noticeable environmental impact; however, its polyphenols may be reused food and feed manufacture as high-value ingredients with antioxidant/antimicrobial activities. The effect of dietary supplementation with OVW polyphenols on the gut microbiota, carcass and breast quality, shelf life, and lipid oxidation in broiler chickens has been studied. Chicks were fed diets supplemented with crude phenolic concentrate (CPC) obtained from OVW (220 and 440 mg/kg phenols equivalent) until reaching commercial size. Cloacal microbial community (rRNA16S sequencing) was monitored during the growth period. Breasts were submitted to culture-dependent and -independent microbiological analyses during their shelf-life. Composition, fatty acid concentration, and lipid oxidation of raw and cooked thawed breasts were measured. Growth performance and gut microbiota were only slightly affected by the dietary treatments, while animal age influenced the cloacal microbiota. The supplementation was found to reduce the shelf life of breasts due to the growth of spoilers. Chemical composition and lipid oxidation were not affected. The hydroxytyrosol (HT) concentration varied from 178.6 to 292.4 ug/kg in breast muscle at the beginning of the shelf-life period. The identification of HT in meat demonstrates that the absorption and metabolism of these compounds was occurring efficiently in the chickens.     

Optimization of an immunoassay of 2,6-dichlorobenzamide (BAM) and development of regenerative surfaces by immunosorbent modification with newly synthesised BAM hapten library

Dichlobenil is an extensively used herbicide worldwide which is transformed to the mobile 2,6-dichlorobenzamide (BAM) in soil. BAM has been found in many European groundwater resources that are exploited for drinking water. Currently, immunoassay based monitoring technique (plate based ELISA) is being employed to quantitatively detect BAM in water samples. In this work, as a starting step of developing immunoassay based on-site monitoring systems for pesticide analysis, the heterogeneous BAM immunoassay is optimised in terms of surface (polymer) regeneration. We have synthesised a small library of BAM haptens which are slightly different in chemical structures, immobilised them on surfaces and compared the affinity constants of the monoclonal antibody HYB 273 towards them. By using ELISA technology, we also have checked the regeneration potentials of the haptens, correlated these results to the affinity constants and found that BAM hapten with an intermediate affinity has better regeneration potential.     

Development of a potassium-selective optode for hydroponic nutrient solution monitoring

Highly efficient and reliable plant growth such as that required in biological life support systems for future space-based missions can be better achieved with knowledge of ion concentrations within the hydroponic nutrient solution. This paper reports on the development and application of ion-selective bulk optodes to plant growth systems. Membranes for potassium-selective sensing are reported that have been tailored so that their dynamic range is centred on potassium activities within typical nutrient solution recipes. The developed sensors have been shown to exhibit a potassium activity measuring range from 0.134 to 117 mM at pH 6.0. These bulk optodes show full scale response on the order of several minutes. They show minimal interference to other cations and meet worst-case selectivity requirements for potassium monitoring in the considered half strength Hoagland solution. When continuously immersed in nutrient solution, these sensors demonstrated predicable lifetimes on the order of 50 h. The developed instrument for absorption-based measurements including light source, mini-spectrometer and optode probe is presented. Custom instrument control and monitoring software including a spectral normalization procedure, use of a dual-wavelength absorbance ratio technique and automatic adjustment for pH variation result in an instrument that is self-calibrating and one that can account for effects such as light source fluctuations, membrane thickness variations and a variety of other factors. The low mass, low volume nature of bulk optode sensing systems, make them a promising technology for future space-based plant production systems. Their low-cost and technology transfer potential suggest that they could provide terrestrial growers a new and reliable mechanism to obtain ion-selective knowledge of their nutrient solution, improving yields, reducing costs and aiding in compliance to continually more stringent environmental regulation.     

钠铝氟化物包覆BaF2材料上转换发光性能

采用水热法合成了一种非稀土上转换发光材料,由钠铝氟化物和BaF2组成。采用X射线衍射(XRD)、傅里叶红外光谱(FTIR)和扫描电镜(SEM)对其进行了表征,分析表明,钠铝氟化物主要以NaF和Na3AlF6两种晶态存在于BaF2晶体表面,形成化学复合,呈现包覆结构。荧光光谱测试表明,样品在583nm可见光和863nm近红外光室温激发下,均能产生304和324nm的宽波段紫外光发射。时间分辨光谱表明,发光均有一个上升和衰减过程,衰减大约自15ms开始,磷光寿命大于18.4ms。借助上转换发光能量转换过程对发光机理进行了研究,分析表明,发光源于量子限制效应的带间光吸收和界面缺陷的光吸收,发光机制属于量子限制效应-界面发光中心复合发光。     

光谱线型函数的四种形式及其变换关系

从理论上研究了光谱线型函数的四种形式及其关系,以多普勒展宽导致的线型函数为例,分析了光子数、能量按频率及波长分布函数的最大值和半高全宽。结果表明,光子数、能量按频率的分布函数近似相等,光子数、能量按波长的分布函数也近似相等。通过对多普勒线型函数的分析,建立了根据两条光谱线的线型函数的最大值比值求得光子数比值的方法。     

生命元素周期变化节律平衡与健康——中国古代“天人合一论”的科学内涵(一)

旅澳学者裘凌沧教授积几十年微量元素科学研究成果,突破传统学科概念的束缚,以东方哲学为核心,运用近代系统工程学方法,分析了生命元素周期变化节律平衡与健康的关系,包括:内、外环境生命元素的特性,系统节律平衡是生命健康的基础和系统节律平衡调控的途徑。本文分期刊出。     

半直线上三阶方程的Legendre-Laguerre耦合谱元法

针对建立在半直线上的三阶微分方程,提出Legendre-Laguerre耦合谱元法.通过构造满足试探函数空间和检验函数空间的基函数,分解得到的线性系统的系数矩阵是稀疏的,可以有效地进行求解.数值例子验证了方法的有效性和高精度.     

Fatigue Life Prediction of a Rubber Mount Based on the Continuum Damage Mechanics

Abstract

Failure analysis and fatigue life prediction are important steps in the design procedure of industrial products to assure the safety and reliability of their components. A new methodology to predict the fatigue life of a rubber mount based on the continuum damage mechanics is proposed in this study. The hyperelastic constitutive model of the natural rubber material in the mount was fitted using the three parameter Mooney-Rivlin model. A damage variable was introduced and the evolution function of cumulative damage in the rubber material was derived. The parameters in the damage function were acquired based on uniaxial tensile tests and fatigue life tests of the natural rubber specimens. Then the finite element analysis (FEA) models of the rubber mount for loads in the X and Y directions were established and the strain contours and the maximum principal strains of the rubber mount under various loads were calculated. The maximum principal strain was used as the fatigue parameter, which was substituted into the natural rubber’s fatigue life damage function to predict the fatigue life of the rubber mount. Finally, the fatigue lives of the rubber mount under various loads were measured on a fatigue test rig to validate the accuracy of the fatigue life prediction method. The test results indicated that the fatigue lives predicted agreed fairly well with the test results and the fatigue prediction method should be applicable to both rubber and other types of components.     

环氧改性的单晶硅表面聚合物薄膜的摩擦学特性研究

以3-（2,3-环氧丙氧）丙基三甲氧基硅烷（GPMS）作为连接层,在单晶硅基底表面制备2,5-呋喃二酮与1-十八烯的共聚物（PMAO）聚合物薄膜.采用傅立叶变换红外光谱仪及原子力显微镜表征薄膜的结构,分别从微观和宏观摩擦学角度考察薄膜的摩擦磨损性能.结果表明：PMAO聚合物通过环氧硅烷分子与基底之间形成化学吸附,GPMS增强了聚合物/无机界面间的粘附性和稳定性;与空白基底相比,聚合物薄膜具有低摩擦系数和优异的抗磨性能,可以作为低载荷下硅基材料的抗磨减摩防护层.