Preparation of thiol-free amino acid plasma matrix for quantification of thiol amino acids and their oxidized forms in human plasma by UPLC-MS/MS.

Thiol amino acids, with great physiological significance, are unstable, and have small molecular weights, as well as very low endogenous concentrations. Therefore, to quantitatively and directly analyze them using liquid chromatography-tandem mass spectrometry is difficult. To overcome these problems, we aimed to prepare a thiol-free amino acid plasm matrix as blank sample to reduce the background for the first time. Using compounds with maleimide group that react with classical thiols to generate water-insoluble products. Reducing agents Tris(2-carboxyethyl)phosphine (TCEP) was applied to cooperate with bismaleimide (DM) for elimination of thiol amino acids from plasma 10 min at room temperature and pH 7. Further, the residual TCEP from plasma were removed using an anion exchange resin within 10 min. Methodological validation analysis revealed good performance in linearity, precision, extraction recovery (≥ 82 %), and stability (except oxidized glutathione). This quantitative analysis was successfully applied to blood samples of 9 people in good health. This study provides a foundation for the development of accurate and rigorous quantitative analysis methods targeting thiol amino acids in different body fluids or tissues. Moreover, it paves the way toward realizing several clinical applications.

The Influence of Social Comparison and Peer Group Size on Risky Decision-Making.

This study explores the influence of different social reference points and different comparison group sizes on risky decision-making. Participants were presented with a scenario describing an exam, and presented with the opportunity of making a risky decision in the context of different information provided about the performance of their peers. We found that behavior was influenced, not only by comparison with peers, but also by the size of the comparison group. Specifically, the larger the reference group, the more polarized the behavior it prompted. In situations describing social loss, participants were led to make riskier decisions after comparing themselves against larger groups, while in situations describing social gain, they become more risk averse. These results indicate that decision making is influenced both by social comparison and the number of people making up the social reference group.

Inventory and general analysis of the ATP-binding cassette (ABC) gene superfamily in maize (Zea mays L.).

The metabolic functions of ATP-binding cassette (or ABC) proteins, one of the largest families of proteins presented in all organisms, have been investigated in many protozoan, animal and plant species. To facilitate more systematic and complicated studies on maize ABC proteins in the future, we present the first complete inventory of these proteins, including 130 open reading frames (ORFs), and provide general descriptions of their classifications, basic structures, typical functions, evolution track analysis and expression profiles. The 130 ORFs were assigned to eight subfamilies based on their structures and homological features. Five of these subfamilies consist of 109 proteins, containing transmembrane domains (TM) performing as transporters. The rest three subfamilies contain 21 soluble proteins involved in various functions other than molecular transport. A comparison of ABC proteins among nine selected species revealed either convergence or divergence in each of the ABC subfamilies. Generally, plant genomes contain far more ABC genes than animal genomes. The expression profiles and evolution track of each maize ABC gene were further investigated, the results of which could provide clues for analyzing their functions. Quantitative real-time polymerase chain reaction experiments (PCR) were conducted to detect induced expression in select ABC genes under several common stresses. This investigation provides valuable information for future research on stress tolerance in plants and potential strategies for enhancing maize production under stressful conditions.