MXene nanosheet-derived N, S-codoped graphene quantum dots for ultrasensitive and selective detection of 3-nitro-l-tyrosine in human serum.

3-Nitro-l-tyrosine (3NT) is an oxidative stress metabolite associated with neurodegenerative diseases such as Parkinson's disease and rheumatoid arthritis. In this study, the N, S-co-doped graphene quantum dots (NSGQDs) derived from nitrogen-doped Ti3C2Tx MXene nanosheet via the hydrothermal method in the presence of mercaptosuccinic acid was synthesized as an optical sensing probe to detect 3NT in human serum. Tetramethyl ammonium hydroxide, the nitrogen source and delamination agent, was used to prepare nitrogen-doped MXene nanosheets via one step at room temperature. The as-prepared NSGQDs are uniform with an average size of 1.2 ± 0.6 nm, and can be stable in aqueous solution for at least 90 d to serve as the fluorescence probe. The N atoms in N-MXene reduce the restacking and aggregation of MXene nanosheets, while the sulfur dopant in NSGQDs increases the quantum yield from 6.2 to 12.1 % as well as enhances the selectivity of 3NT over the other 12 interferences via coordination interaction with nitro group in 3NT. A linear range of 0.02-150 µM in PBS and 0.05-200 µM in human serum with a recovery of 97-108 % for 3NT detection is observed. Moreover, the limit of detection can be lowered to 4.2 and 7 nM in PBS and 1 × diluted human serum, respectively. Results obtained clearly indicate the potential application of the N-Ti3C2Tx derived NSGQD for effective detection of 3NT, which can open a window for the synthesis of doped GQDs via 2D MXene materials for ultrasensitive and selective detection of other biometabolites and biomarkers of neurodegenerative diseases in biological fluids.

Synthesis and antifungal activity of the proposed structure of a volatile compound isolated from the edible mushroom Hypsizygus marmoreus.

We synthesized the proposed structure of an antifungal compound detected in the culture broth of the edible mushroom Hypsizygus marmoreus. Using the Evans aldol and Abiko-Masamune aldol reactions as the key steps, we synthesized all of the stereoisomers of the compound with high stereoselectivity. The GC retention times and the fragmentation patterns in the mass spectra of the synthesized isomers did not match those of the natural product. Therefore, this result may imply that it is necessary to reisolate the natural product and reconsider its structure. All of the synthesized isomers were found to exhibit antifungal activity against the phytopathogenic fungus Alternaria brassicicola. Due to their simple structures, the obtained isomers could be lead compounds for new pesticides.

Two new terpenoids from the leaves of callicarpa macrophylla.

Two new terpenoids (1-2) and seven known compounds (3-9) were isolated from methanol extract of Callicarpa macrophylla leaves. Their structures were determined to be ent-7α,16ß,17,18-tetrahydroxykaur-15-one (1), 3ß-acetoxy-urs-12-ene-11-one-12-ol (2), ent-1ß-acetoxy-7α,14ß-dihydroxykaur-16-en-15-one (3), 3ß-acetoxy-11α,13ß-dihydroxyolean-12-one (4), ß-amyrin (5), spinasterol (6), ursolic acid (7), ß-sitosterol (8), and daucosterol (9) by analyses of their MS, NMR spectroscopic data and by comparison with those reported in the literature. Compounds 1 - 4, and 7 displayed potential cytotoxic activity towards HepG-2, LU-1, and MCF-7 human cancer cell lines with IC50 values ranging from 0.46 ± 0.21 to 18.14 ± 0.33 µM. Compound 6 showed IC50 values of 14.17 ± 0.21 and 5.72 ± 0.42 µM against Hep-G2 and MCF-7 cell lines, respectively.

Radiation Degradation of ß-Glucan with a Potential for Reduction of Lipids and Glucose in the Blood of Mice.

: Water-soluble and low molecular weight (Mw) ß-glucans were successfully prepared by γ-irradiation of water-insoluble yeast ß-glucans. The radiation dose used for the degradation of yeast ß-glucan was remarkably reduced by increasing the pH of the sample or combining with hydrogen peroxide treatment. Radiation-degraded ß-glucans with molecular weights in the range of 11-48 kDa reduced the total cholesterol, triglyceride, low density lipoprotein (LDL) cholesterol, and glucose levels in the blood of administered mice. The decreasing levels of both lipid and glucose indexes in the blood of tested mice strongly depended on the molecular weight of the ß-glucan, and the radiation-degraded ß-glucan with a molecular weight of about 25 kDa was found to be the most effective for the reduction of blood lipid and glucose levels. Particularly, the oral administration of 25 kDa ß-glucan, with a daily dose of about 2 mg per head, reduced the total cholesterol, triglyceride, LDL-cholesterol, and glucose levels in the blood of tested mice to about 47.4%, 48.5%, 45.7%, and 47.2%, respectively. The effects on the reduction of blood lipid and glucose levels were also found to be stable after 20 days of stopping administration. These results indicate that the degraded ß-glucan with a molecular weight of about 25 kDa prepared by γ-ray irradiation is a very promising ingredient that can be used in nutraceutical food for therapeutics of diabetic and dyslipidemia.

Clinical and Microbiological Features of Pediatric Endopthalmitis After Open Globe Injury in the North of VietNam.

BACKGROUND: Pediatric endophthalmitis after open-globe injury had its clinical features, microbiological profile different from those in aldults. In Viet Nam, there was no report on the clinical and microbiological characteristics of pediatric posttraumatic endophthalmitis. Therefore, we conduct this study. AIM: To describe clinical features, ultrasound results, gram stain and culture results of endophthalmitis in pediatric open globe injuries. METHODS: Prospective non-controlled study. Case series of 30 eyes presenting with post-traumatic endophthalmitis between 2015 and 2016 were reviewed. RESULTS: Mean age was 8.03 ± 3.99 years. Metallic and organic etiologies were the most common causes for injuries (n = 11). 27 cases had penetrating corneal trauma. Dense opaque vitreous was seen in 25 eyes. Retinal necrosis < 1 quadrant and chorioretinal abscess > 1 quadrant were the most common fundus lesions. Dense vitreous opacity on ultrasound was most common (n = 28). Gram stain bacteria positivity was 93.3%, gram-positive was isolated in 63.3%. Vitreous samples were more often positive than aqueous (P = 0,002). CONCLUSION: Posttraumatic endophthalmitis in children is more common in boys aged 6-10 years and most often caused by injury with metallic and organic matters. Culture results were very low. Vitreous samples were more often positive than aqueous. Gram-positive bacteria were the most common causative organism.

The prevalence of job stressors among nurses in private in vitro fertilization (IVF) centres.

AIM: The primary aim of this study was to identify the level of stress and the stressors having an impact on nurses compared with other medical workers in private IVF centres. BACKGROUND: Stressful working conditions can an adversely affect not only the health and well-being of health professionals but also subsequently to patient outcomes if care is given to infertile couples. This is of relevance particularly in view of Vietnam's recent economic growth and the increase in the number of private IVF centres. This is the first study looking at the levels of stress experienced by health workers (especially nurses) providing IVF services. DESIGN: A cross-sectional survey. METHODS: All health workers in seven IVF Clinics in HCMC were invited to complete an Occupational Stress Index (OSI) questionnaire. RESULTS: Of the invited 131 medical professionals, 105 (80%) completed the confidential self-administered questionnaire. Thirty-five participants (33.3%) were nurses, 19 (18.1%) were doctors and 51 (48.6%) were lab technicians. Approximately two-thirds reported not having children (67.6%), half (50.48%) married and three-quarters (76.2%) were women, with a significant difference by medical worker group (p < 0.05). Among the three groups, nurses have higher occupational stress index score compared with the others. The OSI score only had a strong relationship with the "high demand" (p < 0.001). Some demographic variables (e.g., income, long working hours, education level) statistically represented the high significant source of job stress.

Potential uses of gut weed Enteromorpha spp. as a feed for herbivorous fish.

Three separate experiments were performed to assess the potential use of gut weeds Enteromorpha spp. as a food source for herbivorous fish. The fresh or dried gut weeds were used as a direct feed to replace commercial feed in an alternative approach for feeding spotted seat (Scatophagus argus), red tilapia (Oreochromis sp.), and giant gourami (Osphronemus goramy) juveniles for 60 days, 45 days, and 56 days, respectively. Four feeding regimes were applied to triplicate tanks and fish was fed daily either commercial feed or gut weed: (1) single commercial feed everyday as a control treatment, (2) single gut weed daily and 2 alternative feeding regimes where (3) 1 day commercial feed and 1 consecutive day gut weed or and (4) 2 consecutive days gut weed. The results indicated that survival of experimental fish was not affected by the feeding treatments. Growth performance of the S. argus fed single gut weed was not significantly different from the control group (P>0.05). Growth rates of Oreochromis sp. and O. goramy in the alternative feeding treatments were comparable to the control treatment. Application of the combined feeding regimes, feed conversion ratio could be reduced from 26.1 to 57.8%. These results indicated that fresh and dried gut weed can be used as a feed to substitute commercial feed for herbivorous fish. Moreover, using gut weeds as a feed could improve water quality in the rearing tanks.

The impact of health education on mother's knowledge, attitude and practice (KAP) of dengue haemorrhagic fever.

A mother’s knowledge, attitude and practice (KAP) study before and after health education of dengue haemorrhagic fever (DHF) was carried out in four communes in Southern Viet Nam. The study showed that health education had made a strong impact on the mothers’ KAP of DHF. The KAP of mothers (how to recognize the child with DHF, how to take care of the child at home, and how to prevent the disease) were improved significantly after health education. This effective programme of health education on DHF can be implemented in other communities as part of the national programme for dengue control.