Anxiety and associated factors among Vietnamese students during COVID-19 pandemic: A cross-sectional study.

Mental health care for students in general, particularly anxiety, is a significant problem that needs more attention, especially during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to describe the prevalence of anxiety and examine the associated factors among students during the COVID-19 pandemic in Vietnam. A cross-sectional study was conducted from August to September 2021 among 5730 students. An online survey was used to collect sociodemographic information, and the generalized anxiety disorder questionnaire (GAD-7) was used to assess anxiety symptoms among Vietnamese students. Results showed that the prevalence of anxiety among study participants was 16.2% (95% confidence interval [CI]: 15.3%-17.2%). Factors related to anxiety among students were gender, type of housemate, COVID-19 exposure/infection status, vaccination status, health status, academic performance, and social relationships during the COVID-19 pandemic. A significant number of students experienced anxiety during COVID-19, and this rate was related to several factors. Psychological interventions are required to support students during and after the COVID-19 pandemic and other health crises. Further studies are required to confirm our findings.

Tandem repeats in precursor protein stabilize transcript levels and production levels of the fungal ribosomally synthesized and post-translationally modified peptide ustiloxin B.

Ustiloxin B is a ribosomally synthesized and post-translationally modified peptide (RiPP) first reported in Ascomycetes. Its biosynthetic pathway was recently identified in the filamentous fungus Aspergillus flavus. The precursor protein of ustiloxin B, UstA, has a signal peptide to the endoplasmic reticulum at its N-terminal and a subsequent tandemly highly repeated segment cleaved at Lys-Arg dipeptides by Kex2 protease; such proteins are called Kex2-processed repeat proteins (KEPs). RiPP biosynthetic pathways using KEPs as precursor proteins are widely distributed in the Fungi kingdom, with high diversity of precursor protein sequences. UstA in A. flavus has a 16-fold tandemly repeated segment containing the core peptide Tyr-Ala-Ile-Gly, which forms the ustiloxin B backbone structure, but it is unknown why such a costly-to-maintain highly repeated sequence is retained. Here, we replaced ustA, the gene encoding the ustiloxin B precursor protein, with synthetic genes encoding 1-, 3-, 5-, 7-, and 11-fold tandem-repeat segments in A. flavus, to investigate the relationship between the repeat number and ustiloxin B production. Ustiloxin B production increased quadratically with increasing repeat number in ustA variants, although it dropped in a previously constructed ustA variant that had a substituted synthetic gene encoding a 16-fold repeat segment probably because of the presence of the many rare codons in the sequence. We also examined the transcript levels of substituted synthetic genes in ustA variants, and surprisingly we found that the transcript levels of the synthetic genes increased linearly with increasing repeat number. This result implies that an unknown mechanism stabilizes ustA transcripts via the highly repeated structure in a feedback manner. We also constructed a transformant without the intron in native ustA, but no effect of intron removal was observed on either ustiloxin B production or the precursor gene transcript level. The costly-to-maintain highly repeated sequence in KEPs probably serves the purpose of maintaining stable transcripts and thus increasing the amount of substrate.

Mechanistic insights into the dehydrogenation of formaldehyde, formic acid and methanol using the Pt4 cluster as a promising catalyst.

Reaction mechanisms of the dehydrogenation of formaldehyde, formic acid and methanol on the Pt4 cluster were computationally investigated using density functional theory (DFT) with the B3LYP functional in the conjunction with the aug-cc-pVTZ basis sets for H, C and O atoms, and the cc-pVDZ-PP basis set for Pt. Herein, the key mechanistic aspects of three possible pathways of the dehydrogenation of these compounds are summarized. The results indicate that the formation of H2 and CO or CO2 molecules is more energetically favorable than the generation of H and H2O, HCHO products. Generally, the formation of H2 molecule in the presence of catalysts is more favorable than the direct decomposition of either HCHO, HCOOH or CH3OH molecule. The use of Pt4 catalyst significantly reduces the energy barriers for C-H and O-H bond cleavage of all three compounds to 14, 9 and 12 kcal/mol, respectively. The decomposition of HCOOH is found to be the most energetically favorable. In addition, the mechanistic insights of the reactions confirm the reduction of the energy barriers of the gas-phase dehydrogenation by 67-82 kcal/mol and bring it to the values smaller than 14 kcal/mol in the presence of the Pt4 catalysts.

Effectiveness and Tolerability of First-Line Afatinib for Advanced EGFR-Mutant Non-Small Cell Lung Cancer in Vietnam.

BACKGROUND: We aimed to evaluate the effectiveness and tolerability of Afatinib as first-line treatment of advanced epidermal growth factor receptor (EGFR) mutant non small cell lung cancer (NSCLC) in a real-world setting. PATIENTS AND METHODS: This is a retrospective study of Vietnamese patients  with advanced EGFR-mutant NSCLC treated with first-line afatinib at the National Cancer Hospital from 1st January 2018 to 31st October 2020. Patients' demographic, clinical and treatment data were captured. Objective response rate (ORR), disease control rate (DCR), time to treatment failure (TTF) and tolerability were evaluated. We used Kaplan-Meier curve and log-rank test for survival, and Cox regression model for multivariate analysis. RESULTS: A total of 44 patients were included. Common EGFR mutations (Del 19/L858R) were detected in 61% patients. Fifty percent of patients with uncommon mutations had compound mutations of G719X, L861Q and S768I. The ORR was 75% while DCR rate was 98%. The median TTF was 12.3 months (95% CI: 7.2-17.3); the mTTFs were 12.3 and 10.8 months for patients with common and uncommon mutations (p = 0.001), respectively, and 14.0 and 7.5 months for patients with Del 19 and L858R mutations (p = 0.067), respectively. Afatinib 30 mg once daily was the most common starting (77%) and maintenance (64%) doses. The mTTFs were 12.3 and 7.5 months for patients with 30 mg starting dose vs 40 mg dose (p = 0.256), respectively. Diarrhea, skin rash, paronychia and fatigue were observed in 32%, 30%, 25% and 9%, respectively. There was no grade 4 toxicity except three patients with grade 3 paronychia. CONCLUSIONS: First-line afatinib is beneficial for Vietnamese patients with advanced EGFR-mutant NSCLC with a good response rate and prolonged TTF with manageable adverse event profile. Baseline brain metastasis status and starting doses do not significantly impact TTF.
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Promoter tools for further development of Aspergillus oryzae as a platform for fungal secondary metabolite production.

BACKGROUND: The filamentous fungus Aspergillus oryzae is widely used for secondary metabolite production by heterologous expression; thus, a wide variety of promoter tools is necessary to broaden the application of this species. Here we built a procedure to survey A. flavus genes constitutively highly expressed in 83 transcriptome datasets obtained under various conditions affecting secondary metabolite production, to find promoters useful for heterologous expression of genes in A. oryzae. RESULTS: To test the ability of the promoters of the top 6 genes to induce production of a fungal secondary metabolite, ustiloxin B, we inserted the promoters before the start codon of ustR, which encodes the transcription factor of the gene cluster responsible for ustiloxin B biosynthesis, in A. oryzae. Four of the 6 promoters induced ustiloxin B production in all tested media (solid maize, liquid V8 and PDB media), and also ustR expression. Two of the 4 promoters were those of tef1 and gpdA, which are well characterized in A. oryzae and A. nidulans, respectively, whereas the other two, those of AFLA_030930 and AFLA_113120, are newly reported here and show activities comparable to that of the gpdA promoter with respect to induction of gene expression and ustiloxin B production. CONCLUSION: We newly reported two sequences as promoter tools for secondary metabolite production in A. oryzae. Our results demonstrate that our simple strategy of surveying for constitutively highly expressed genes in large-scale transcriptome datasets is useful for finding promoter sequences that can be used as heterologous expression tools in A. oryzae.

Drosophila Ubiquitin C-Terminal Hydrolase Knockdown Model of Parkinson's Disease.

Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide. Many factors have been shown to contribute to its pathogenesis including genetic and environmental factors. Ubiquitin C-terminal hydrolase L1 (UCHL1) is also known to be involved in the pathogenesis of PD. We herein modeled the study of UCHL1 in Drosophila melanogaster and investigated its functions in PD. The specific knockdown of the Drosophila ortholog of UCHL1 (dUCH) in dopaminergic neurons (DA neurons) led to the underdevelopment and/or degeneration of these neurons, specifically in DL1 DA neuron cluster in the larval brain lobe and PPM2, PPM3, PPL2ab, and VUM DA neuron clusters in the adult brain. These defects were followed by a shortage of dopamine in the brain, which subsequently resulted in locomotor dysfunction. The degeneration of DA neurons in dUCH knockdown adult brain, which occurred progressively and severely during the course of aging, mimics the epidemiology of PD. DA neuron and locomotor defects were rescued when dUCH knockdown flies were treated with vitamin C, a well-known antioxidant. These results suggest that dUCH knockdown fly is a promising model for studying the pathogenesis and epidemiology of PD as well as the screening of potential antioxidants for PD therapeutics.

Three-step procedure for preparation of pure Bacillus altitudinis ribonuclease.

Ribonucleases are considered as promising tools for anticancer treatment due to their selective cytotoxicity against tumor cells. We investigated a new RNase from Bacillus altitudinis termed BALNASE (B. altitudinis RNase). Balnase is a close homolog of the well-known cytotoxic binase, differing by only one amino acid residue: nonpolar hydrophobic alanine at position 106 in the balnase molecule is replaced by a polar uncharged threonine in binase. The most exciting question is how the physico-chemical properties and biological effects of RNase might be changed by A106T substitution. Here, we have developed a chromatography-based rapid and modern technique for the purification of this new RNase which allowed us to get a protein sample of high quality with specific activity of 1.2 × 10(6) units in preparative amounts, suitable for further investigation of its biological properties.

Full-scale bioreactor pretreatment of highly toxic wastewater from styrene and propylene oxide production.

The wastewater originating from simultaneous production of styrene and propylene oxide (SPO) is classified as highly polluted with chemical oxygen demand level in the range 5965 to 9137mgL(-1)-as well as highly toxic. The dilution factor providing for a 10 percent toxic effect of wastewater samples in a test with Paramecium caudatum was 8.0-9.5. Biological approach for pretreatment and detoxification of the wastewater under full-scale bioreactor conditions was investigated. The number of suspended microorganisms and the clean up efficiency were increased up to 5.5-6.58×10(8)CFUmL(-1) and 88 percent, respectively during the bioreactor's operation. Isolates in the Citrobacter, Burkholderia, Pseudomonas, and Paracoccus genera were dominant in the mature suspended, as well as the immobilized microbial community of the bioreactor. The most dominant representatives were tested for their ability to biodegrade the major components of the SPO wastewater and evidence of their role in the treatment process was demonstrated. The investigated pretreatment process allowed the wastewater to be detoxified for conventional treatment with activated sludge and was closely related to the maturation of the bioreactor's microbial community.