Acute Kidney Injury and Gut Dysbiosis: A Narrative Review Focus on Pathophysiology and Treatment

Acute kidney injury (AKI) and gut dysbiosis affect each other bidirectionally. AKI induces microbiota alteration in the gastrointestinal (GI) system, while gut dysbiosis also aggravates AKI. The interplay between AKI and gut dysbiosis is not yet well clarified but worthy of further investigation. The current review focuses on the pathophysiology of this bidirectional interplay and AKI treatment in this base. Both macrophages and neutrophils of the innate immunity and the T helper type 17 cell from the adaptive immunity are the critical players of AKI-induced gut dysbiosis. Conversely, dysbiosis-induced overproduction of gut-derived uremic toxins and insufficient generation of short-chain fatty acids are the main factors deteriorating AKI. Many novel treatments are proposed to deter AKI progression by reforming the GI microbiome and breaking this vicious cycle. Data support the benefits of probiotic treatment in AKI patients, while the results of postbiotics are mainly limited to animals. Prebiotics and synbiotics are primarily discussed in chronic kidney disease patients rather than AKI patients. The effect of adsorbent treatment seems promising, but more studies are required before the treatment can be applied to patients. Immune therapy and some repurposed drugs such as allopurinol are prospects of future treatments and are worth more discussion and survey.     

FeCl3/KI-Catalyzed Tandem Oxidative Cyclization for Switchable Total Synthesis of Luotonin A,B and Derivatives

A total synthesis strategy was developed for the synthesis of luotonin A, B and their analogues using synergistic FeCl₃/KI-catalyzed oxidative cyclization. This protocol utilizes cheap and widely available N-propargyl 2-methyl-quinazolinones and arylamines under mild conditions, and it has a wide substrate scope and high atom economy. Different natural products (luotonin A, B and derivatives) can be synthesized via a unique switchable approach. Further transformations from luotonin B to luotonin E and structural modification of natural products demonstrate the potential applications of this method. Moreover, camptothecin can also be modified with the reported protocol to afford the hydroxyl-substituted product.     

食源性致病微生物的检测新技术

研究和建立食源性致病微生物的有效检测方法对于食品安全风险控制及人们的身体健康具有重要意义。本文在简要介绍微生物传统检测技术的基础上,系统地介绍了各类食源性致病微生物检测新方法,包括微生物试纸片检测技术、微生物代谢物检测技术、微生物免疫学检测技术、微生物DNA检测技术、微生物传感器检测技术等,分析了各类食源性微生物检测方法的基本原理、优缺点和应用,并对食源性致病微生物的检测新技术的发展提出了设想。     

臭氧处理协同低压静电场对青见柑橘低温贮藏品质的影响

目的 探究臭氧处理联合低压静电场(low voltage electrostatic field, LVEF)对青见柑橘的保鲜效果。方法 青见柑橘随机分为臭氧组(4.0 mg/m3, 30 min)、LVEF组(2400 V, 5 mA)、臭氧+LVEF组和对照(control check, CK)组,4℃冷藏。测定其贮藏期间水分含量、可滴定酸(titratable acid, TA)、可溶性糖、可溶性固形物(soluble solid content, SSC)、维生素C (vitamin C, VC)含量、硬度和水分迁移情况变化。结果 贮藏期间,各组青见柑橘TA、可溶性糖、SSC、VC含量、硬度、水分含量均呈下降趋势,腐烂率呈上升趋势,且臭氧+LVEF组对于青见柑橘贮藏品质的维持效果显著优于CK组、臭氧组和LVEF组(P<0.05)。此外,臭氧组和LVEF组对青见柑橘贮藏品质的维持效果均显著优于CK组,而LVEF组对青见柑橘贮藏品质维持效果显著低于臭氧组(P<0.05)。横向弛豫时间T2反演谱结果显示,与新鲜样品相比,贮藏至40 d的青见柑橘的结合水无显著性变化,不易流动水含量有所上升,自由水含量显著下降,臭氧处理联合LVEF保鲜可显著抑制青见柑橘自由水含量的减少(P<0.05)。结论 贮藏期间,臭氧处理、LVEF贮藏和臭氧处理联合LVEF均能抑制青见柑橘品质的劣化且臭氧处理+LVE效果最好。     

Preparation and annealing study of CrTaN coatings on WC-Co

To prevent Co diffusion from cemented carbides at high working temperatures, we fabricated CrTaN coatings by reactive direct current magnetron co-sputtering onto 6 wt.% cobalt cemented carbide substrates, to form diffusion barrier layers. The nitrogen flow ratio, N₂/(Ar + N₂), during the sputtering process was set at 0.4. The deposition rates of CrTaN coatings varied from 23 to 27 nm/min. The CrTaN coatings crystallized into a columnar structure, without heating the substrates during the sputtering process and exhibited surface hardness and Young's modulus values of 16–27 and 211–383 GPa, respectively. The CrTaN coatings were annealed at 500 and 600 °C for 4 h in air to evaluate the oxidation resistance and diffusion barrier performance. We also investigated oxidation resistance of the CrTaN coatings under a 50 ppm O₂–N₂ atmosphere, to assess the fabricated layers effectiveness as a protective coating for glass molding dies.     

The glycerol and ethanol production kinetics in low-temperature wine fermentation using Saccharomyces cerevisiae yeast strains

Increasing glycerol production in low-temperature wine fermentation is of concern for winemakers to improve the quality of wines. The objective of this study was to investigate the effect of 10 different Saccharomyces cerevisiae on the kinetics of production of glycerol, ethanol and the activities of glycerol-3-phosphate dehydrogenase (GPD) and alcohol dehydrogenase (ADH) in low-temperature fermentation. Ethanol production was influenced by temperature, and it was slightly higher at 13 °C than at 25 °C. Glycerol yields were significantly affected by both temperature and strains. More glycerol was produced at 25 °C than at 13 °C because the activity of GPD was higher at 25 °C than at 13 °C. Glycerol production of the different yeast strains was up to 3.19 and 3.18 g L⁻¹ at 25 and 13 °C, respectively. Therefore, isolating the yeast strains with high glycerol production and adaptation to low-temperature fermentation is still the best method in winemaking.     

Automatic disulfide bond assignment using a1 ion screening by mass spectrometry for structural characterization of protein pharmaceuticals

An automatic method for disulfide bond assignment using dimethyl labeling and computational screening of a(1) ions with customized software, RADAR, is developed. By utilization of the enhanced a(1) ions generated from labeled peptides, the N-terminal amino acids from disulfide-linked peptides can be determined. In this study, we applied this method for structural characterization of recombinant monoclonal antibodies, an important group of therapeutic proteins. In addition to a(1) ion screening and molecular weight match, new RADAR is capable of confirming the matched peptide pairs by further comparing the collision-induced dissociation (CID) fragment ions. With the N-terminal amino acid identities as a threshold, the identification of disulfide-linked peptide pairs can be achieved rapidly at a higher confidence level. Unlike most current approaches, prior knowledge of disulfide linkages or a high-end mass spectrometer is not required, and tedious work or deliberate interpretation can be avoided in this study. Our approach makes it possible to analyze unknown disulfide bonds of protein pharmaceuticals as well as their degraded forms without further protein separation. It can be used as a convenient quality examination tool during biopharmaceutical development and manufacturing processes.     

Quantitative characterization of nanoparticles in blood by transmission electron microscopy with a window-type microchip nanopipet

Transmission electron microscopy (TEM) is a unique and powerful tool for observation of nanoparticles. However, due to the uneven spatial distribution of particles conventionally dried on copper grids, TEM is rarely employed to evaluate the spatial distribution of nanoparticles in aqueous solutions. Here, we present a microchip nanopipet with a narrow chamber width for sorting nanoparticles from blood and preventing the aggregation of the particles during the drying process, enabling quantitative analysis of their aggregation/agglomeration states and the particle concentration in aqueous solutions. This microchip is adaptable to all commercial TEM holders. Such a nanopipet proves to be a simple and convenient sampling device for TEM image-based quantitative characterization.