Molecular and Crystal Structure of a New 24-nor-Triterpenoid Carboxylic Acid from Acanthopanax Trifoliatus

The molecular and crystal structure of the new nortriterpene 24-nor-3a,l1a-dihydroxy-lup-20(29)-en-28-oic acid isolated from the Araliaceae Acanthopanax trifoliatus has been determined on the basis of X-ray analysis of its methyl ester

Some chemical constituents isolated from Acorus tatarinowii Shott.

Anew 8,1′-neolignan, tatarinone, 4-[2-(1,2,3-trimethoxybenz-5-yl)-1-methylethyl]-2,5-dimethoxy-4-(2-propenyl)-2,5-cyclohexadien-1-one, has been isolated from Acorus tatarinowii rhizome and  its structure determined by spectroscopic methods, including 2D-NMR spectra. Asarylaldehyde and a mixture of α-asarone and β-asarone were also isolated and  indentified.Keywords: Acorus tatarinowii;Araceae; 8,1′-neolignans; asarylaldehyde; α-asarone; β-asarone; NMR

Kinetics of neutralizing antibodies against Omicron variant in Vietnamese healthcare workers after primary immunization with ChAdOx1-S and booster immunization with BNT162b2

We studied the development and persistence of neutralizing antibodies against SARS-CoV-2 ancestral strain, and Delta and Omicron (BA.1 and BA.2) variants in Vietnamese healthcare workers (HCWs) up to 15 weeks after booster vaccination. We included 47 HCWs, including group 1 (G1, N = 21) and group 2 (G2; N = 26) without and with breakthrough Delta variant infection before booster immunization, respectively). The study participants had completed primary immunization with ChAdOx1-S and booster vaccination with BNT162b2. Neutralizing antibodies were measured using a surrogate virus neutralization assay. Of the 21 study participants in G1, neutralizing antibodies against ancestral strain, Delta variant, BA.1, and BA.2 were (almost) abolished at month 8 after the second dose, but all had detectable neutralizing antibodies to the study viruses at week 2 post booster dose. Of the 26 study participants in G2, neutralizing antibody levels to BA.1 and BA.2 were significantly higher than those to the corresponding viruses measured at week 2 post breakthrough infection and before the booster dose. At week 15 post booster vaccination, neutralizing antibodies to BA.1 and BA.2 dropped significantly, with more profound changes observed in those without breakthrough Delta variant infection. Booster vaccination enhanced neutralizing activities against ancestral strain and Delta variant compared with those induced by primary vaccination. These responses were maintained at high levels for at least 15 weeks. Our findings emphasize the importance of the first booster dose in producing cross-neutralizing antibodies against Omicron variant. A second booster to maintain long-term vaccine effectiveness against the currently circulating variants merits further research

Chemical composition and acetylcholinesterase inhibitory activity of essential oil from rhizomes of Distichochlamys benenica

Twenty-seven constituents were identified by using GC/MS, representing 99.57% of the rhizome oil of Distichochlamys benenica. The major constituents of the essential oil are 1,8-cineole (54.39%), β-pinene (7.50%), (E)-citral (7.26%), and (Z)-citral (6.79%). The rhizome essential oil has anti-acetylcholinesterase activity with an IC50 value of 136.63 ± 2.70 mg/mL

Novel Learning of Bathymetry from Landsat 9 Imagery Using Machine Learning, Feature Extraction and Meta-Heuristic Optimization in a Shallow Turbid Lagoon

Bathymetry data is indispensable for a variety of aquatic field studies and benthic resource inventories. Determining water depth can be accomplished through an echo sounding system or remote estimation utilizing space-borne and air-borne data across diverse environments, such as lakes, rivers, seas, or lagoons. Despite being a common option for bathymetry mapping, the use of satellite imagery faces challenges due to the complex inherent optical properties of water bodies (e.g., turbid water), satellite spatial resolution limitations, and constraints in the performance of retrieval models. This study focuses on advancing the remote sensing based method by harnessing the non-linear learning capabilities of the machine learning (ML) model, employing advanced feature selection through a meta-heuristic algorithm, and using image extraction techniques (i.e., band ratio, gray scale morphological operation, and morphological multi-scale decomposition). Herein, we validate the predictive capabilities of six ML models: Random Forest (RF), Support Vector Machine (SVM), CatBoost (CB), Extreme Gradient Boost (XGB), Light Gradient Boosting Machine (LGBM), and KTBoost (KTB) models, both with and without the application of meta-heuristic optimization (i.e., Dragon Fly, Particle Swarm Optimization, and Grey Wolf Optimization), to accurately ascertain water depth. This is achieved using a diverse input dataset derived from multi-spectral Landsat 9 imagery captured on a cloud-free day (19 September 2023) in a shallow, turbid lagoon. Our findings indicate the superior performance of LGBM coupled with Particle Swamp Optimization (R2 = 0.908, RMSE = 0.31 m), affirming the consistency and reliability of the feature extraction and selection-based framework, while offering novel insights into the expansion of bathymetric mapping in complex aquatic environments

Uncovering gender disparities in payment for forest environmental services (PFES): A feminist political ecology view from Vietnam

Despite the Payment for Forest Environmental Services (PFES) program being recognized for its achievements in promoting environmental conservation and empowering forest-dependent communities, its vertical impacts require a more nuanced investigation, given the constantly changing policy landscape in Vietnam. In 2023, we employed the Feminist Political Ecology (FPE) approach to examine gender disparities in PFES participation, resource accessibility, decision-making power, and knowledge of PFES across 66 households in A Luoi district, Thua Thien Hue province, Vietnam. Our findings reveal striking gender gaps in PFES participation, resource accessibility, decision-making power, and knowledge, with men dominating meetings and training programs, and having their names predominantly listed in forest land certificates, while women's perspectives are often overlooked. These inequities are deeply entrenched in patriarchal ideologies and traditional social prejudices, which have systematically excluded women from development programs. Moreover, our research uncovered a significant lack of knowledge about PFES among both men and women in the study community, partly attributable to institutional factors and command-and-control structures. We argue that achieving gender-equitable governance requires a multifaceted and nuanced approach that recognizes the complexity and diversity of institutions at the household and community level. Gender equality is a constantly evolving process with a wide range of issues and debates at various levels. Therefore, a long-term, gender-sensitive approach that empowers women and recognizes their critical role in forest governance is imperative for promoting equitable and sustainable development

Assessment and Sustainable Management Strategies for Plastic Waste in Can Tho City, Vietnam: A Circular Economy Approach

This study presents a comprehensive analysis of plastic waste accumulation in both terrestrial and aquatic environments in Can Tho city, Vietnam, a nation with high per capita plastic consumption and significant plastic waste discharge. Focusing on urban residential areas, riverside communities, suburbs, and rural regions, the research investigates the extent and impact of plastic waste in these diverse settings. Additionally, the study examines the accumulation of plastics at barriers, under bridges, and in the Hau River, identifying the predominance of single-use plastics and their environmental implications. The key findings indicate that the plastic waste leakage at land-based-source emission sites is substantial, with waste persisting for extended periods without effective clean-up. The study reveals a significant accumulation of plastics at barriers and bridge bases in aquatic environments, including along the river. The pollution level was observed to be more influenced by the quantity of waste rather than its mass per unit area, emphasizing the need for targeted waste reduction strategies. The study also identifies seven types of plastic, each associated with different sources of accumulation or settlement. This variety presents both challenges and opportunities for waste management and recycling. Significantly, the research underscores the potential of repurposing plastic waste into recycled products, aligning with the circular economy model. This approach not only extends the lifecycle of plastic products but also contributes to reducing plastic waste generation and minimizing the environmental impact. Overall, the findings highlight the urgent need for improved waste management practices in Vietnam, particularly in urban and riverside areas, and advocate for innovative recycling solutions to mitigate the environmental challenges posed by plastic pollution

Cerebrospinal fluid MinION sequencing of 16S rRNA gene for rapid and accurate diagnosis of bacterial meningitis: Letter to the Editor

Analysis of angiotensin-converting enzyme 2 (ACE2) from different species sheds some light on cross-species receptor usage of a novel coronavirus 2019-nCo

Superspreading event of SARS-CoV-2 infection at a bar, Ho Chi Minh City, Vietnam

We report a superspreading event of severe acute respiratory syndrome coronavirus 2 infection initiated at a bar in Vietnam with evidence of symptomatic and asymptomatic transmission, based on ministry of health reports, patient interviews, and whole-genome sequence analysis. Crowds in enclosed indoor settings with poor ventilation may be considered at high risk for transmission