Assessment of aflatoxin B1 contamination in rice and maize

Introduction: Aflatoxins B1 are among the most common poisonous mycotoxins produced by certain fungi that harm animals and crops. Mycotoxins can cause a variety of adverse health effects and pose a serious health threat to humans. The Maximum Residue Limits of aflatoxin B1 in processed cereals and ingredients are 2 parts per billion (ppb) and 5 ppb, respectively. Objectives: To evaluate the status of aflatoxin B1 contamination in rice, corn and staple food produced in Ha Giang province compared with the maximum permitted levels. Methods: A total of 210 rice and maize samples were analyzed to quantify the level of aflatoxin B1. Analysis of mycotoxins was conducted by High Performance Liquid Chromatography using a fluorescence detector. Results: It was found that rice, rice products, maize, and maize products had a mean aflatoxin B1 content of 1.79 ppb, 2.55 ppb, 2.19 ppb, and 6.35 ppb, respectively. The results also showed that 71.9% of samples were contaminated with mycotoxins, and 14.28% of samples exceeded the maximum allowable limit. Conclusion: The concentration of aflatoxin B1 in 14.28% of the samples are over permissible limits by nationwide regulations.

Introducción: La aflatoxina B1 se encuentra entre las micotoxinas más comunes y venenosas producidas por ciertos hongos que dañan a los animales y los cultivos. Las micotoxinas pueden causar una variedad de efectos adversos para la salud y representar una grave amenaza para la salud de los seres humanos. Los límites máximos de residuos de aflatoxina B1en cereales e ingredientes procesados son de 2 ppb y 5 ppb, respectivamente. Objetivos: Evaluar el estado de contaminación por aflatoxina B1 en arroz, maíz y alimentos básicos producidos en la provincia de Ha Giang, en comparación con los niveles máximos permitidos. Métodos: Se analizaron un total de 210 muestras de arroz y maíz para cuantificar el nivel de aflatoxina B1. El análisis de micotoxinas se realizó mediante cromatografía líquida de alta resolución, utilizando un detector de fluorescencia. Resultados: Se encontró que el arroz, los productos de arroz, el maíz y los productos de maíz tenían un contenido medio de aflatoxin B1, de 1,79 ppb, 2,55 ppb, 2,19 ppb y 6,35 ppb, respectivamente. Los resultados también mostraron que el 71,9 % de las muestras estaban contaminadas con micotoxinas y el 14,28 % de las muestras excedieron el límite máximo permitido. Conclusión: La concentración de aflatoxina B1 en el 14,28 % de las muestras está por encima de los límites permisibles por la norma nacional.

Improving electrochemical performance of hybrid electrode materials by a composite of nanocellulose, reduced oxide graphene and polyaniline.

Novel ternary composites of polyaniline (PANI), reduced graphene oxide (RGO), and cellulose nanofibers (CNFs) are prepared by a chemical method for hybrid supercapacitors. CNFs were extracted from sugarcane bagasse waste in sugar production, by physicochemical processes. The composites were investigated as electrode-active materials for hybrid supercapacitors. The obtained results revealed that the presence of RGO and CNFs in the composites led to enhanced electrochemical performances, such as capacitance, rate capability, and long-term cyclability of the composite. The optimal composite of CNFs/RGO/PANI with a weight ratio of 4/16/80 can deliver the highest specific capacitance at 566.2 F g-1 under an applied current of 1 A g-1. After 1000 cycles of repetitive charge and discharge, the optimal composite retains 85.4% of its initial capacitance, whereas the PANI electrode obtained only 36.7% under the same conditions. Moreover, the supercapacitive performance is also strongly dependent on the component of the ternary composites. Overall, the composite is a promising material for hybrid supercapacitors; and the CNF component is a renewable material and a product of waste materials.

Cytotoxic activity of steroidal glycosides from the aerial parts of Solanum torvum collected in Thua Thien Hue, Vietnam.

A phytochemical investigation of Solanum torvum led to the isolation of eleven steroidal glycosides, including neochlorogenin 6-O-ß-D-quinovopyranoside (1), (22 R,23S,25R)-3ß-6α,23-trihydroxy-5α-spirostane 6-O-ß-D-xylopyranosyl-(1→3)-ß-D-quinovopyranoside (2), neochlorogenin 6-O-α-L-rhamnopyranosyl-(1→3)-ß-D-quinovopyranoside (3), solagenin 6-O-α-L-rhamnopyranosyl-(1→3)-ß-D-quinovopyranoside (4), paniculonin A (5), paniculonin B (6), 6α-O-[ß-D-xylopyranosyl-(1→3)ß-D-quinovopyranosyl]-(25S)-5α-spirostan-3ß-ol (7), torvoside J (8), torvoside K (9), torvoside L (10) and solagenin 6-O-ß-D-quinovopyranoside (11). Their chemical structures were elucidated by 1D-NMR and 2D-NMR data as well as comparison with the data reported in the literature. Moreover, all isolated compounds were evaluated for their cytotoxic activities against SK-LU-1, HepG2, MCF-7 and T24 cancer cell lines. Among them, compounds 1, 3, 7 and 11 exhibited cytotoxicity against all four tested cell lines with IC50 values ranging from 7.89 ± 0.87 to 46.76 ± 3.88 µM.

Identification of a polymorphism in the N gene of SARS-CoV-2 that adversely impacts detection by a widely-used RT-PCR assay

We identify a mutation in the N gene of SARS-CoV-2 that adversely affects annealing of a commonly used RT-PCR primer; epidemiologic evidence suggests the virus retains pathogenicity and competence for spread. This reinforces the importance of using multiple targets, preferably in at least 2 genes, for robust SARS-CoV-2 detection. Article Summary LineA SARS-CoV-2 variant that occurs worldwide and has spread in California significantly affects diagnostic sensitivity of an N gene assay, highlighting the need to employ multiple viral targets for detection.

Efficacy of Oral Low-Dose Isotretinoin in the Treatment of Acne Vulgaris in Vietnam.

BACKGROUND: Oral isotretinoin is an effective therapy for acne. However, isotretinoin can induce hyperhomocysteinemia and decreased serum folic acid level, which may be a risk for cardiovascular disease and thrombosis, as well as psychoses. Besides, many recent types of research emphasise the safety and effects of the low dose isotretinoin therapy. AIM: The aim of our study was to evaluate the effect of the low-dose isotretinoin on the plasma homocysteine and serum folic acid level in the Vietnamese population. METHODS: We conducted a longitudinal study to evaluate the effectiveness of the low-dose therapy on the plasma homocysteine and serum folic acid level of 52 acne patients after 6-8-week treatment at University Medical Center Ho Chi Minh City, Viet Nam. Patients had moderate-severe acne with the prolonged course, and most of them had a scar. RESULTS: With a low dose of oral isotretinoin (0.37 ± 0.11 mg/kg/day), after 6-8-week treatment, patients dropped the severity of disease, increased the plasma homocysteine level and decreased the serum folic acid level with significant differences in comparison to those before treatment. However, these changes do not exceed the normal range. CONCLUSION: In overall, low dose isotretinoin treatment had effectiveness in decrease the severity of disease and no increasing the plasma homocysteine level as well as the serum folic acid level.