ABSTRACT
Chitin, the second most abundant biomolecule after cellulose in nature, is a significant aquaculture by-product, and is estimated at 6-8 million tons annually. Chitin is composed of monomeric N-acetylglucosamine (NAG) which can be seen as an alternative feedstock for biotechnology. Microbial functional lipids have gained attention due to their bioactivity and sustainable production. In this study, a new oleaginous yeast strain named Sakaguchia sp. HKC2 was found to be able to use NAG as the carbon source for growth and accumulate functional lipids such as PUFAs and carotenoids. When cultured on the NAG-containing medium, strain HKC2 exhibited slower growth and slower intracellular lipid accumulation compared to those on a glucose-containing medium. However, the lipids obtained from HKC2 grown on NAG medium were richer in PUFAs. Notably, torularhodin-a powerful bioactive carotenoid-was found in all HKC2 cultures on NAG, while torulene was abundant in glucose medium. These findings highlight a novel avenue for utilizing aquatic by-products and unlocking their potential.
ABSTRACT
PURPOSE: The fourth wave of the COVID-19 pandemic has dramatically influenced many aspects of individuals' lives, putting the general population's mental health at high risk, especially university students in Vietnam. The present study aims to investigate the relationship between current living status and COVID-19 stress and test whether COVID-19 stress mediates the effect of self-concealment on help-seeking attitudes among university students. PATIENTS AND METHODS: A sample of 478 university students was recruited online to complete the survey. Parametric tests, correlation, regression, and simple mediation analyses were used to analyze the data. RESULTS: Our results show that students living alone experience more COVID-19 stress levels than those living with family or friends. Additionally, there is a significant positive association between self-concealment and professional help-seeking attitudes that is partially mediated by COVID-19 stress. Individuals who tend to conceal personal information have high COVID-19 stress levels, leading to positive professional help-seeking attitudes. CONCLUSION: University administrators, social workers, counselors, clinicians, and therapists must consider students living alone as prioritized vulnerable groups for early mental health interventions. Clinicians should be aware of self-concealment and professional help-seeking attitudes that could influence psychological treatment.
ABSTRACT
A method for the simultaneous determination of seven B-group vitamers including thiamine, riboflavin, nicotinamide, niacin, pyridoxine, pyridoxal, and pyridoxamine in nutritional products by using enzymatic digestion followed by LC-MS/MS quantification was studied. The LC-MS/MS conditions such as MS transitions, mobile phase programs, and ammonium formate buffer concentrations, and sample treatment procedures (e.g., concentrations of buffer solution, digestion temperature, and digestion time) were investigated. The analytical method performance was evaluated by multiple criteria such as selectivity, linearity, detection and quantification limits, repeatability, reproducibility, and recovery by using real sample matrices. The validated method was successfully applied to analyze vitamin B concentrations in different nutritional products like ultra-heat-treated milk, powdered milk, and nutritional powder. Vitamin B concentrations varied over a wide range from lower than detection limits to about 9000 µg/100 g, depending on vitamin groups, compound forms, and sample types. The measured concentrations of B-group vitamins in our samples were generally in good agreement with values of label claims.
