Tyrosine Supplementation A Nutraceutical Approach to Counter Heat Stress Induced Cognitive Decline

Supplementation of tyrosine, non-essential amino acid, and precursor of catecholamine was found to ameliorate the heat-induced alterations in latencies of event-related potential P300 and contingent negative variation. Here we present the effect of tyrosine supplementation on heat stress (exposure to ambient temperature 45 oC and relative humidity 30 %) induced alterations in behavior (attention, mood) and levels of plasma monoamines. Ten healthy male participants received a placebo food bar or tyrosine-containing food bar (6.5 g in 50 g) 90 min before heat stress exposure of 90 min. Plasma and urine samples were assayed for catecholamine levels, their precursor, and metabolites using high-performance liquid chromatography. A computer-based automated test battery was used to assess attention and mood by profile of mood states questionnaire. A significantly higher plasma tyrosine (p<0.001) leading to an increased norepinephrine (p<0.05) levels in the tyrosine supplemented group was observed. Selective (p<0.001) and sustained attention (p<0.02) in the tyrosine group were significantly better compared to the placebo group. Reaction time and anger scores decreased (p<0.001) with tyrosine supplementation. It may be concluded that tyrosine supplementation improves heat stress-induced decrement in attention by maintaining the synthesis and turnover of norepinephrine.

OPTIMIZED AND VALIDATED SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF AMPICILLIN IN PHARMACEUTICAL FORMULATIONS

Objective: A simple, precise, and accurate spectrophotometric method has been developed to determine Ampicillin in pharmaceutical formulations. Methods: The proposed method, based on the carboxylic acid group reaction, present in Ampicillin with a mixture of KIO3 and KI, form a yellow-colored product in an aqueous medium. The response was allowed to proceed at 25±1 °C, and absorbance measured after 5 min against a reagent blank prepared simultaneously using a UV-Vis spectrophotometer. The parameters verified were specificity, linearity, linearity range, accuracy, precision, detection limit, quantitation limit, robustness, and ruggedness. Results: The yellow-colored product was measured at 352 nm against the reagent blank using UV–Vis spectrophotometer. The linear dynamic range of concentration was 0.25–2.5 µg/ml with a correlation coefficient of 0.9999. The LOD, LOQ values to be 0.086 and 0.261 µg/ml, respectively, for the proposed method. The percentage of recoveries was 98.27–100.89% with an acceptable relative standard deviation (±2%). The robustness and ruggedness values were excellent. Conclusion: The ICH guidelines for pharmaceuticals and human use were followed and applied to validate the proposed method. The method was compared with available literature and found similar results that confirmed the reliability and effective way for Ampicillin's determination.

BETWEEN THE RIGHT AND THE COMMON. HOW GROUPS REACT TO SOCIALLY UNDESIRABLE BEHAVIOUR

The aim of the paper is to analyse the relationship between group characteristics and the scope of reaction of the group to socially undesirable behaviour. Sometimes small groups or communities fail to react to undesirable or violent behaviour and their apathy can have devastating consequences. Such a situation can occur among co-workers witnessing workplace mobbing, or neighbours who do not react to a suspicion of domestic violence. Reasons for their inaction are diverse and can include fear, doubts concerning the necessity of such a reaction, and also conformity. In the paper I examine a seemingly favourable situation: I assume that reaction is costless and all the members of the group would like to react (internalised norm), but they also want to conform. In order to analyse the factors that can influence the scope of group reaction, a structurally embedded sequential coordination game was played for different initial conditions. Computer simulations were conducted for networks of a specific type (Erd¨os-R´enyi random graph). The main aim of the analysis was to identify non-structural and structural features of the group that can impede or even block the intervention of the group. There is a positive relationship between the scope of group reaction and the strength of the internalized norm, whereas the level of conformity affects the chances of group intervention in a negative way. Heterogeneity of the group is an important factor - the scope of reaction is higher when members of the group have different levels of norm internalisation and conformity. There is a non-linear relationship between network density and the scope of reaction. Both low and high density can make it harder for people to act.

Synthesis of Epoxy-Functionalized Micro-Zone Plates by UV-Initiated Copolymerization

As microfluidic systems transition from research tools to disposable clinical devices, new substrate materials are need to meet both the regulatory requirement as well as the economics of disposable devices. In this paper, a commercial ultraviolet (UV)-curiable material (bisphenol A based epoxy acrylate, BABEA) was introduced as a new manufacturing material for facile fabrication of epoxy-functionalized microfluidic devices by UV-initiated copolymerization. X-ray photoelectron spectroscope (XPS) results indicated the existence of epoxy groups on the surface of poly (BABEA-co-GMA), which allowed for binding protein through an epoxy-amino group reaction. Poly (BABEA-co-GMA) is highly transparent in visible range, and of high replication fidelity. A fabrication procedure was proposed for manufacturing BABEA based epoxy-functionalized micro-zone plates. The fabrication procedure was very simple; obviating the need of micromachining equipments, wet etching or imprinting techniques. To evaluate the BABEA based epoxy-functionalized micro-zone plates, α-fetoprotein (AFP) antibody was immobilized onto the capture zone for chemiluminescent (CL) detection in a non-competitive immune response format. The proposed AFP immunoaffinity micro-zone plate was demonstrated as a low cost, flexible, homogeneous and stable assay for AFP.