Mycosporine-like amino acids: relevant secondary metabolites. Chemical and ecological aspects

Taxonomically diverse marine, freshwater and terrestrial organisms have evolved the capacity to synthesize, accumulate and metabolize a variety of UV-absorbing substances called mycosporine-like amino acids (MAAs) as part of an overall strategy to diminish the direct and indirect damaging effects of environmental ultraviolet radiation (UVR). Whereas the enzymatic machinery to synthesize MAAs was probably inherited from cyanobacteria ancestors via the endosymbionts hypothesis, metazoans lack this biochemical pathway, but can acquire and metabolize these compounds by trophic transference, symbiotic or bacterial association. In this review we describe the structure and physicochemical properties of MAAs, including the recently discovered compounds and the modern methods used for their isolation and identification, updating previous reviews. On this basis, we review the metabolism and distribution of this unique class of metabolites among marine organism.     

Optimization strategies for Cd and Pb immobilization in soil using meta-analysis combined with numerical modeling

Chemical immobilization is one of the most effective technologies for remediating sites with heavy metals,but the selection of proper immobilization material and determination of its dose ratio is a challenge that limits the remediation efficiency.In this study,we conducted a meta-analysis of 489 independent observations on the immobilization of heavy metals,in which the immobilization materials were divided into biochar,phosphate,lime,metal oxides,and clay minerals.The statistical analysis of t...     

Blood cellular immune response in pigs immunized and challenged with Haemophilus parasuis

The cellular immune response to an experimental infection by Haemophilus parasuis, the etiological agent of Glässer’s disease in pigs, was characterized studying changes in peripheral blood mononuclear cells (PBMC) in colostrum-deprived pigs. Five groups were studied, four of those were previously immunized with different formulations and the fifth was maintained as non-immunized control. All groups were challenged with 5 × 10⁹ CFU of H. parasuis serotype 5. The non-commercial bacterin conferred a complete protection, while the OMP-vaccine and the exposure to a subletal dose of 10⁵ CFU of H. parasuis protected only partially, and the recombinant Tbp B-vaccine induced no protection. PBMC were analyzed using monoclonal antibodies against porcine CD45⁺, CD3⁺, CD4⁺, CD8α⁺, CD25⁺, CD4⁺ naïve, αIgM⁺ and SWC3⁺ cells in single-colour fluorescence, and CD4⁺/CD8α⁺ and CD8α⁺/CD8β⁺ combinations in two-colour fluorescence. The different groups showed no significant changes in PBMC subsets following vaccination, and only minor changes were encountered after challenge, consisting mainly of significant increases (P < 0.05) in the relative proportions of monocytes and granulocytes (SWC3⁺) and B cells (αIgM⁺), as well as a significant reduction in CD3⁺ cells (P < 0.05). These changes were similar for the five groups compared, except for the significant increase of CD25⁺ cells, which was only observed for the bacterin-vaccinated group. These results suggest an increase of trafficking of inflammatory cells and the onset of the adaptive antibody response against H. parasuis infection; in addition, the blood cellular response developed by the different groups was not relevant to protection.     

DDGS可用作奶牛饲料的原料

DDGS是“烧酒糟残液干燥物”的英文Distiller’s dried Grain with Soluble第一个大写字母的缩写（也有专业杂志将DDGS译成“干酒精糟及可溶物”或“可溶性干酒糟”等,译名不同,指的是同一种产品。另据报道,中国乙醇生物燃料从2003年的7万吨飙升到2006年100万吨——译者注）,它是乙醇生物燃料的副产物。随着美国中西部清洁能源——乙醇生物燃料产业的发展,可作为奶牛饲料用的DDGS副产物的产量也逐年增加。     

观赏鱼全价营养饲料的研制

观赏鱼指金鱼、热带鱼和锦锂等一些可供人们欣赏的鱼类。它不仅可美化环境 ,丰富人们的业余生活 ,而且从中也可陶冶人的精神情操。随着我国国际贸易的发展 ,这些鱼早就作为一种观赏动物出口 ,远销日本、东南亚和欧美等国家 ,换取外汇 ,为祖国四个现代化建设筹集资金 ,也增进了同世界各国人民之间的友谊。同时 ,在科学研究中观赏鱼也是进行遗传、发育、生态、癌症和毒性试验等材料。长期以来 ,国际上测定各种药物对鱼类的毒性指标都以金鱼为试验动物。因此 ,发展观赏鱼养殖业在经济、科研方面都有重要的意义。然而 ,在城市和农村伴随市政和农…     

当今的热门话题——BST

牛生长激素(BST)是利用生物工程(大肠菌基因重组技术)而得到的一种蛋白质。在美国,研究 BST 除了孟山都公司外,还有三家大公司也在研究 BST。美国几所大学的试验表明,泌乳牛注射 BST 能大幅度提高产乳量(10-20%)。在美国的宣传和推动下,其他的研究机构也证实了 BST 的效果。日本的《畜产