抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Fish bioaccumulation and biomarkers in environmental risk assessment: a review

The fish gill is a multipurpose organ that, in addition to providing for aquatic gas exchange, plays dominant roles in osmotic and ionic regulation, acid-base regulation, and excretion of nitrogenous wastes Thus, despite the fact that all fish groups have functional kidneys, the gill epithelium is the site of many processes that are mediated by renal epithelia in terrestrial vertebrates Indeed, many of the pathways that mediate these processes in mammalian renal epithelial are expressed in the gill, and many of the extrinsic and intrinsic modulators of these processes are also found in fish endocrine tissues and the gill itself The basic patterns of gill physiology were outlined over a half century ago, but modern immunological and molecular techniques are bringing new insights into this complicated system Nevertheless, substantial questions about the evolution of these mechanisms and control remain

https://people.clas.ufl.edu/devans/files/PRVGill.pdf

The Multifunctional Fish Gill: Dominant Site of Gas Exchange, Osmoregulation, Acid-Base Regulation, and Excretion of Nitrogenous Waste

Nature And Properties Of Soils

Silver nanoparticles are nanoparticles of silver which are in the range of 1 and 100 nm in size. Silver nanoparticles have unique properties which help in molecular diagnostics, in therapies, as well as in devices that are used in several medical procedures. The major methods used for silver nanoparticle synthesis are the physical and chemical methods. The problem with the chemical and physical methods is that the synthesis is expensive and can also have toxic substances absorbed onto them. To overcome this, the biological method provides a feasible alternative. The major biological systems involved in this are bacteria, fungi, and plant extracts. The major applications of silver nanoparticles in the medical field include diagnostic applications and therapeutic applications. In most of the therapeutic applications, it is the antimicrobial property that is being majorly explored, though the anti-inflammatory property has its fair share of applications. Though silver nanoparticles are rampantly used in many medical procedures and devices as well as in various biological fields, they have their drawbacks due to nanotoxicity. This review provides a comprehensive view on the mechanism of action, production, applications in the medical field, and the health and environmental concerns that are allegedly caused due to these nanoparticles. The focus is on effective and efficient synthesis of silver nanoparticles while exploring their various prospective applications besides trying to understand the current scenario in the debates on the toxicity concerns these nanoparticles pose.

/pdf/silver-nanoparticles-mechanism-of-antimicrobial-action-3x1asgjbb2.pdf

Silver nanoparticles: mechanism of antimicrobial action, synthesis, medical applications, and toxicity effects

Abstract The European Commission requested EFSA to provide an assessment of the processing conditions which make Ambrosia seeds non‐viable in feed materials and compound feed. This assessment also includes information on a reliable procedure to verify the non‐viability of the seeds. Ambrosia seeds are known contaminants in feed with maximum levels set in the Directive 2002/32/EC. The manufacturing processes and processing conditions applied to the feed may affect the viability of the Ambrosia seeds. Therefore, the CONTAM Panel compared these conditions with conditions that have been shown to be sufficient to render Ambrosia seeds non‐viable. The Panel concluded with a certainty of 99–100% that solvent extraction and toasting of oilseed meals at temperatures of 120°C with steam injection for 10 min or more will make Ambrosia seeds non‐viable. Since milling/grinding feed materials for compound feed of piglets, aquatic species and non‐food producing animals would not allow particles of sizes ≥1 mm (the minimum size of viable Ambrosia seeds) passing the grinding process it was considered very likely (with ≥ 90% certainty) that these feeds will not contain viable Ambrosia seeds. In poultry, pig, and possibly cattle feed, particle sizes are ≥ 1 mm and therefore Ambrosia seeds could likely (66–90% certainty) survive the grinding process. Starch and gluten either from corn or wheat wet milling would not contain Ambrosia seeds with 99–100% certainty. Finally, ensiling fresh forages contaminated with A. artemisiifolia seeds for more than 3 months is very likely to render all seeds non‐viable. The Panel concluded that a combination of the germination test and a subsequent triphenyl‐tetrazolium‐chloride (TTC) test will very likely (with ≥ 90% certainty) verify the non‐viability of Ambrosia seeds. The Panel recommends that data on the presence of viable Ambrosia seeds before and after the different feed production processes should be generated.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.2903/j.efsa.2023.8102

Assessment of the processing conditions which make the Ambrosia seeds non‐viable

Zinc pre-exposure improves Zn resistance by demethylation of metallothionein 2 and transcription regulation of zinc-regulatory genes in zebrafish ZF4 cells.

Christer Hogstrand

Papers

Assessment of the processing conditions which make the Ambrosia seeds non‐viable

Zinc pre-exposure improves Zn resistance by demethylation of metallothionein 2 and transcription regulation of zinc-regulatory genes in zebrafish ZF4 cells.