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Environmental changes and human impact can alter biodiversity in negative manners that affect mankind’s sustainable development. Particularly, such effects on inland waters are even more concerning, as those ecosystems play essential roles in sustaining human life as well as relevant wildlife. Thus, in this study, we investigated such effects on microbial diversity in inland waters in Vietnam using bacterial communities in sediment as indicators. To do this, we collected sediment samples from various locations in three respective regions (Red river in the north, Ba river in the central area, and Mekong delta flood zone in the south) using standard methods, extracted their total DNA, sequenced their V3-V4 16S rRNA gene fragments using an Illumina Miseq platform and analyzed the sequences to infer the diversity of the bacterial communities in the samples. These communities were compared in terms of richness (alpha diversity) and composition (beta diversity), and the correlations between their diversity levels and environmental factors, as well as human activities, were analyzed by using standard statistical tools. Our results showed that the communities were different from each other solely by region, in richness and critically in composition, although there were some communities distinctively different from all the others. Among environmental factors, only water salinity (and conductivity) had negative correlations with alpha-diversity indices of the bacterial communities, and phosphate concentration and turbidity had positive correlations, while the other factors had almost no correlations, which partially explains the region-specific diversity. These results also suggest that climate change incidences, especially sea intrusion, can have significant effects on microbial diversity in inland waters. The impact of human activities did not appear severe, solely affecting bacterial community richness, but not significantly affecting bacterial community composition. However, apparently reduced bacterial diversity in several sites with intense human impacts and distinct environmental conditions should be noted and deserve further investigation.

(1) Background: The detection of methylated SEPT9 (mSEPT9) in plasma is a promising approach to non-invasive colorectal cancer (CRC) screening. Traditional approaches have limitations in sensitivity and cost-effectiveness, particularly in resource-limited settings. (2) Methods: We developed a semi-nested realtime PCR assay utilizing extendable blocking probes (ExBP) to enhance the detection of low-level mSEPT9 based on DNA melting. This assay allows for the discrimination of mSEPT9 in the presence of high concentrations of non-methylated SEPT9 (up to 100,000 times higher). (3) Results: The assay demonstrated a sensitivity of 73.91% and specificity of 80%, showcasing its ability to detect very low levels of methylated DNA effectively. The innovative use of ExBP without costly modified probes simplifies the assay setup and reduces the overall costs, enhancing its applicability in diverse clinical settings. (4) Conclusions: This novel assay significantly improves the detection of mSEPT9, offering a potential advance in CRC screening and monitoring. Its cost-efficiency and high sensitivity make it particularly suitable for the early detection and management of CRC, especially in settings with limited resources. Future studies are encouraged to validate this assay in larger populations to establish its clinical benefits and practical utility.

We theoretically investigated the nitrogen substitution effect on the molecular structure and π-electron delocalization in linear nitrogen-substituted polycyclic aromatic hydrocarbons (N-PAHs). Based on the optimized molecular structures and magnetic field-induced parameters of fused bi- and tricyclic linear N-PAHs, we found that the local π-electron delocalization of subcycles (e.g., mono- and bicyclic constituent moieties) in linear N-PAHs is preserved, despite deviation from ideal structures of parent monocycles. The introduction of a fused five-membered ring with a pyrrolic N atom (N-5MR) in linear N-PAHs significantly perturbs the π-electronic condition of the neighboring fused six-membered ring (6MR). Monocyclic pyrrole exhibits substantial bond length alternations, strongly influencing the π-electronic systems of both the fused N-5MR and 6MR in linear N-PAHs, depending on the location of shared covalent bonds. A fused six-membered ring with a graphitic N atom in an indolizine moiety cannot generate monocyclic π-electron delocalization but instead contributes to the formation of polycyclic π-electron delocalization. This is evidenced by bifurcated diatropic ring currents induced by an external magnetic field. In conclusion, the satisfaction of Hückel’s 4n + 2 rule for both mono- and polycycles is crucial for understanding the overall π-electron delocalization. It is crucial to consider the unique characteristics of the three types of substituted N atoms and the spatial arrangement of 5MR and 6MR in N-PAHs.

Indoor air quality (IAQ) directly affects human health. The increase in PM and CO2 concentration indoors caused an increase in the prevalence of sick building syndrome (SBS) symptoms. Plants could contribute to reducing particulate matter (PM) and CO2. This study identifies the most efficient evergreen plant species for improving indoor air quality by assessing the ability of five different indigenous Korean evergreen plant species to reduce PM and CO2 and regulate humidity and temperature under indoor environmental conditions in acrylic chambers. The clean air delivery rates (CADR) were calculated to evaluate the efficacy of plants in reducing PM and CO2. We assessed the performance of removing the five study plants on PM1 (~0.68–3.01 m3/h/leaf area), PM2.5 (~0.73–3.08 m3/h/leaf area), PM10 (~0.67–3.04 m3/h/leaf area), and CO2 (~0.48–1.04 m3/h/leaf area). The species Ilex pedunculosa, Pittosporum tobira, and Gardenia jasminoides were the most effective at reducing PM. The CADR of CO2 also differed among the five plant species and corresponded to their photosynthetic rate. Viburnum odoratissimum var. awabuki, which had the high photosynthetic rate, was most effective at reducing CO2. By contrast, PM reduction was correlated with plant leaf structure. Plants with a high leaf density can accumulate more PM. The plants were also able to control temperature and humidity. The average temperature of the control chamber was higher, and the humidity was lower than that of the plant chambers. In this study, the five evergreen species effectively reduced air pollutants and can be used to improve IAQ.

Detecting the boundaries of geologic structures is one of the main tasks in interpreting gravity anomalies. Many methods based on the derivatives of gravity anomalies have been introduced to map the source boundaries. The drawbacks of traditional methods are that the estimated boundaries are divergent or false boundaries appear in the output map. Here, we use the exponential transform of the tilt angle of the horizontal gradient to improve the edge detection results. The robustness of the presented method is illustrated using synthetic data and real examples from the Voisey’s Bay Ni-Cu-Co deposit (Canada) and the Tuan Giao (Vietnam). The findings show that the presented technique can produce more precise and clear boundaries.

The medicinal mushroom Cordyceps militaris is widely exploited in traditional medicine and nutraceuticals in Asian countries. However, fruiting body production in C. militaris is facing degeneration through cultivation batches, and the molecular mechanism of this phenomenon remains unclear. This study showed that fruiting body formation in three different C. militaris strains, namely G12, B12, and HQ1, severely declined after three successive culturing generations using the spore isolation method. PCR analyses revealed that these strains exist as heterokaryons and possess both the mating-type loci, MAT1-1 and MAT1-2. Further, monokaryotic isolates carrying MAT1-1 or MAT1-2 were successfully separated from the fruiting bodies of all three heterokaryotic strains. A spore combination of the MAT1-1 monokaryotic isolate and the MAT1-2 monokaryotic isolate promoted fruiting body formation, while the single monokaryotic isolates could not do that themselves. Notably, we found that changes in ratios of the MAT1-2 spores strongly influenced fruiting body formation in these strains. When the ratios of the MAT1-2 spores increased to more than 15 times compared to the MAT1-1 spores, the fruiting body formation decreased sharply. In contrast, when MAT1-1 spores were increased proportionally, fruiting body formation was only slightly reduced. Our study also proposes a new solution to mitigate the degeneration in the heterokaryotic C. militaris strains caused by successive culturing generations.

Developing highly efficient and durable hydrogen evolution reaction (HER) electrocatalysts is crucial for addressing the energy and environmental challenges. Among the 2D-layered chalcogenides, MoSe2 possesses superior features for HER catalysis. The van der Waals attractions and high surface energy, however, stack the MoSe2 layers, resulting in a loss of edge active catalytic sites. In addition, MoSe2 suffers from low intrinsic conductivity and weak electrical contact with active sites. To overcome the issues, this work presents a novel approach, wherein the in situ incorporated diethylene glycol solvent into the interlayers of MoSe2 during synthesis when treated thermally in an inert atmosphere at 600 °C transformed into graphene (Gr). This widened the interlayer spacing of MoSe2, thereby exposing more HER active edge sites with high conductivity offered by the incorporated Gr. The resulting MoSe2-Gr composite exhibited a significantly enhanced HER catalytic activity compared to the pristine MoSe2 in an acidic medium and demonstrated a superior HER catalytic activity compared to the state-of-the-art Pt/C catalyst, particularly at a high current density beyond ca. 55 mA cm−2. Additionally, the MoSe2-Gr catalyst demonstrated long-term electrochemical stability during HER. This work, thus, presents a facile and novel approach for obtaining an efficient MoSe2 electrocatalyst applicable in green hydrogen production.

Particulate matter (PM) is the most dangerous type of air pollutant and is harmful to human health. Plants can be used as a biofilter to remove PM from the atmosphere and improve air quality. In this study, we used the air pollution tolerance index and four leaf traits of five different plant species commonly used in landscaping in Korea to determine which plants are best suited to remove PM from the atmosphere in roadside areas in spring, summer, and autumn. We found that the PM concentrations in the atmosphere impacted the amount of PM accumulated in the plants, with increased PM accumulation during periods of increased environmental PM levels on the roadside. Euonymus japonicus, and Euonymus alatus accumulated the highest amount of PM and had the highest tolerance levels to air pollution. Thus, these species could be suitable for use in areas with high PM concentrations to improve air quality. We also found that shrubs were more effective in accumulating PM than trees and recommend that shrubs and trees be used together to further increase the amount of PM removed from the atmosphere in urban areas.

Access to a reliable and safe domestic water supply is a serious challenge for many developing countries worldwide. In the capital of Vietnam, Hanoi, the municipal government is facing a number of difficulties in providing sufficient water in a sustainable manner due to the increasing urban population and the serious pollution of both surface and groundwater resources, but this is also due to a lack of resources to invest in the supply system. This study aimed to investigate water users’ willingness to pay for the improvement of Hanoi’s domestic water supply system. A contingent valuation process based on a survey of 402 respondents was used to explore citizens’ willingness to pay (WTP) for the improvement of their urban water supply. The results show that Hanoi’s urban communities (more than 90%) were generally satisfied with the quantity of their water supply, but tended to be dissatisfied with its quality, with 80% of the respondents using advanced water purifiers before drinking and cooking. Respondents were also concerned about the overall reliability of the service, with 40% of respondents indicating that they received no check and maintenance service. A WTP regression model was developed based on the survey findings. The average WTP is 281,000 dong/household/month (approximately 12.2 USD at the exchange rate of 1 USD to about 23,000 VND), equivalent to 1.4% of the average household income at the end of 2019, indicating the level of affordability of monthly water payments among Hanoi citizens.

Nanodiamond (ND) has recently emerged as a potential nanomaterial for nanovaccine development. Here, a plant-based haemagglutinin protein (H5.c2) of A/H5N1 virus was conjugated with detonation NDs (DND) of 3.7 nm in diameter (ND4), and high-pressure and high-temperature (HPHT) oxidative NDs of ~40–70 nm (ND40) and ~100–250 nm (ND100) in diameter. Our results revealed that the surface charge, but not the size of NDs, is crucial to the protein conjugation, as well as the in vitro and in vivo behaviors of H5.c2:ND conjugates. Positively charged ND4 does not effectively form stable conjugates with H5.c2, and has no impact on the immunogenicity of the protein both in vitro and in vivo. In contrast, the negatively oxidized NDs (ND40 and ND100) are excellent protein antigen carriers. When compared to free H5.c2, H5.c2:ND40, and H5.c2:ND100 conjugates are highly immunogenic with hemagglutination titers that are both 16 times higher than that of the free H5.c2 protein. Notably, H5.c2:ND40 and H5.c2:ND100 conjugates induce over 3-folds stronger production of both H5.c2-specific-IgG and neutralizing antibodies against A/H5N1 than free H5.c2 in mice. These findings support the innovative strategy of using negatively oxidized ND particles as novel antigen carriers for vaccine development, while also highlighting the importance of particle characterization before use.