Paleo-climatic control on recharge and fresh-salt groundwater distribution in the Red River delta plain, Vietnam.

Paleo-climatic induced sedimentation controls present-day recharge and the fresh-salt groundwater distribution in Quaternary delta systems. During sea-level highstands, marine clays with saline pore water were deposited and are interbedded with aquifers of coarse-grained sandy fluvial and shallow marine deposits, laid down during lowstands. The low-permeable marine layers may inhibit recent recharge to deeper aquifers, and thereby limit sustainable use of these freshwater resources.

Robust interaction of ZnO and TiO nanoparticles with layered graphitic carbon nitride for enhanced photocatalytic oxidative desulfurization of fuel oil: mechanism, performance and stability.

Sulfur compounds in fuel such as thiophene, benzothiophene and dibenzothiophene are the primary source of SO emissions, leading to environmental pollution and acid rain. In this study, we synthesized a layered oxygen-doped graphitic carbon nitride (OCN) structure and integrated ZnO and TiO nanoparticles onto the OCN surface through a microwave-assisted sol-gel method. The X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) results confirmed a robust interaction between the ZnO and TiO nanoparticles and the oxygen-doped g-CN (OCN) surface, as indicated by the formation of C-N-Ti and C-O-Ti bonds.

Investigation on cost-effective composites for CO adsorption from post-gasification residue and metal organic framework.

Cost-effective CO adsorbents are gaining increasing attention as viable solutions for mitigating climate change. In this study, composites were synthesized by electrochemically combining the post-gasification residue of Macadamia nut shell with copper benzene-1,3,5-tricarboxylate (CuBTC). Among the different composites synthesized, the ratio of 1:1 between biochar and CuBTC (B 1:1) demonstrated the highest CO adsorption capacity.

3D models for hydrothermal copper ore bodies at Sin Quyen deposit, North Vietnam: A case report for ore reserves and prediction of hidden mineral resource potential.

The complex iron oxide copper and gold (IOCG) Sin Quyen deposit in northern Vietnam is known as hydrothermal veins and multi-stages of mineralization. Thus, it is complicated to make a probabilistic 3D geometric model using traditional methods and to predict the hidden mineral potential. In this study, computer modeling with nearly 8000 archival data was recorded from 146 boreholes within the study area, and the chemical analysis was done on 40 samples.

Environmental relevance monitoring and assessment of ochreous precipitates, hydrochemistry and water sources from abandoned coal mine drainage.

This study investigated the mineralogical and chemical characteristics of ochreous precipitates and mine water samples from abandoned Upper Carboniferous hard coal mines in an extensive former mining area in western Germany. Mine water characteristics have been monitored and assessed using a multi-methodological approach. Thirteen mine water discharge locations were sampled for hydrochemical analysis, with a total of 46 water samples seasonally collected in the whole study area for stable isotopic analyses.

Reliable Tilt-depth estimates based on the stable computation of the tilt angle using robust vertical derivatives.

The Tilt-depth is a popular approach for determining depths of magnetic sources. As this method is based on the distance between contour levels of the tilt angle, it can lead to inaccurate depth estimates when the contour lines are distorted by the presence of noise. In this paper, we stabilize the Tilt-depth method based on the computation of stable vertical derivative obtained by the β-VDR method.

Reference the seabed topographic depth observations based on the national mean dynamic topography model.

The mean sea surface in different regions is non-equipotential, rendering Vietnam's traditional approach, which relies on the Hon-Dau tide gauge station as a reference, not yet scientifically invalid. To overcome this, our study utilized the Vietnam national mean dynamic topography model (MDTVN22) for depth observations, particularly in the Gulf of Tonkin. Covering 3430 monitoring sites in Hai Phong and 813 sites in Quang Ninh, our experiments highlighted a 5 to 6 mm difference between the mean sea surface and MDTVN22 references.

Synthesis of SiO@Ag Nanocomposite for Investigating Metal-Enhanced Fluorescence and Surface-Enhanced Raman Spectroscopy.

SiO@Ag nanocomposite (NC) has been synthesized by the chemical reduction and Stӧber method for Metal-enhanced fluorescence (MEF) of Rhodmine 6G (R6G) and Surface-enhanced Raman spectroscopy (SERS) of Malachite green (MG). As-synthesized SiO@Ag NC indicated SiO nanosphere (NS) and Ag nanoparticle (NP) morphologies. The SiO@Ag NC was high quality with a well-defined crystallite phase with average sizes of 24 nm and 132 nm for Ag NP and SiO NC, respectively.

Four New Steroidal Saponins from the Roots of Dracaena cambodiana with NO Production Inhibition Activity in LPS Activated RAW 264.7 Cells.

Seven steroidal saponins including three new 16,23-cyclocholestanes (1-3) and one new pregane (4) were isolated from the roots of Dracaena cambodiana Pierre ex Gagnep. Their chemical structures were elucidated to be (23R,25R)-26-O-β-D-glucopyranosyl-16,23-cyclocholesta-5,17(20)-dien-22-one-3β,16α,26-triol-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-β-D-glucopyranoside (1), (23R,25R)-26-O-β-D-glucopyranosyl-16,23-cyclocholesta-5,17,20(22)-trien-3β,22,26-triol-3-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucopyranoside (2), (23R,25R)-16,23-cyclocholesta-5,16,20(22)-trien-3β,22,26-triol-3-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucopyranoside (3), 3β-[(O-α-L-rhamnopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-β-D-gluco-pyranosyl)oxy]-pregna-5,17(20)-diene-16-one-20-carboxylic acid 4''''-O-β-D-glucopyranosylisopentyl ester (4), cambodianoside A (5), diosbulbiside C (6), and diosbulbiside D (7), by IR, HR-ESI-MS, 1D and 2D NMR spectra. Compounds 1 and 4-7 inhibited nitric oxide (NO) production in lipopolysaccharide activated RAW 264.

FeO/CuO/Chitosan Nanocomposites: An Ultrasound-Assisted Green Approach for Antibacterial and Photocatalytic Properties.

The fundamental goal of this research was to use an environmentally friendly sonochemical method to synthesize a FeO/CuO/chitosan magnetic nanocomposite. The nanocomposites featured particle sizes ranging from 50 to 90 nm, and structural characteristics were thoroughly examined. Moreover, the material displayed selective photodegradation capabilities with MB, achieving an impressive efficiency of nearly 98% within 180 min under specific conditions.

Unmet needs for care for activities of daily living among older adults with functional disabilities in Vietnam.

Background: Given its low-middle-income status, Vietnam is experiencing a rapidly aging population. Along with this demographic trend, the care needs of older adults, particularly those with functional disabilities, have become an emerging policy issue.

Purpose: This study examined the prevalence of unmet needs for care in activities of daily living (ADLs) among Vietnamese older adults with functional disabilities.

Incorporating Industrial By-Products into Geopolymer Mortar: Effects on Strength and Durability.

In recent years, the reuse of industrial waste has become increasingly important for sustainable development. Therefore, this study investigated the application of granulated blast furnace slag (GBFS) as a cementitious replacement material in fly-ash-based geopolymer mortar containing silica fume (GMS). The performance changes in the GMS samples manufactured with different GBFS ratios (0-50 wt%) and alkaline activators were evaluated.

Healthcare Services Utilisation and Financial Burden among Vietnamese Older People and Their Households.

Background: This research examined differences in the utilisation of healthcare services and financial burden between and within insured and uninsured older persons and their households under the social health insurance scheme in Vietnam.

Methods: We used nationally representative data from the Vietnam Household Living Standard Survey (VHLSS) conducted in 2014. We applied the World Health Organization (WHO)'s financial indicators in healthcare to provide cross-tabulations and comparisons for insured and uninsured older persons along with their individual and household characteristics (such as age groups, gender, ethnicity, per-capita household expenditure quintiles, and place of residence).

Assessing water quality in the Dong Nai River (Vietnam): implications for sustainable management and pollution control.

Dong Nai River provides essential water resources for millions of people across 11 provinces and cities in Vietnam. However, the different pollution sources such as household, farming, and industrial operations have caused the river water quality to deteriorate over the past decade. To gain a comprehensive understanding of the river's surface water quality, this study employed the water quality index (WQI) across 12 different sampling sites.

Polypyrrole-based nanocomposites doped with both salicylate/molybdate and graphene oxide for enhanced corrosion resistance on low-carbon steel.

In this work, polypyrrole-based nanocomposites doped with graphene oxide, molybdate, and salicylate (PPy/GO/Mo/Sal) were synthesized via electrochemical polymerization to enhance the anti-corrosion protection performance of polymer coatings. The morphology and structures of the coatings were characterized by SEM, EDX, FTIR, Raman spectroscopy, and XRD. The protection abilities of coatings against corrosion were investigated in 0.

Four new lignans obtained from the leaves of Schisandra cauliflora and their effect on skeletal muscle cell proliferation.

Plants of the Schisandra genus are commonly used in folk medicinal remedies. Some Schisandra species and their lignans have been reported to improve muscle strength. In the present study, four new lignans, named schisacaulins A-D, together with three previously described compounds ananonin B, alismoxide, and pregomisin were isolated from the leaves of S.

Radiological risk assessment of outdoorRn andRn around rare earth element and uranium mines from northern Vietnam.

The outdoorRn andRn concentrations at 320 sampling points at 1 m above the ground in different sites surrounding rare earth element (REE) and uranium mines from northern Vietnam were measured using the RAD7. Results showed thatRn concentrations were always higher thanRn concentrations with large variation ranges from 25.7 to 573 Bq mand from 18.

Radiological Hazard Assessment of High-Level Natural Radionuclides in Surface Sediments Along Red River, Vietnam.

The Red River is one of the largest rivers that plays an important role in the economic development of North Vietnam. There are many radionuclides bearing rare earth, uranium ore mines, mining industrial zones and magma intrusive formations along this river. The contamination and accumulation of radionuclides could exist at high concentration in surface sediments of this river.

A new iridoid glucoside from the roots of .

A new iridoid glucoside, moridoside (), and nine known compounds, asperulosidic acid (), 6---acetylscandoside (), geniposidic acid (), 2-hydroxymethylanthraquinone (), 2-hydroxymethyl-3-hydroxyanthraquinone (), damnacanthol (), lucidine-ω-methyl ether (), 2-hydroxy-1-methoxyanthraquinone (), and 3,8-dihydroxy-1,2-dimethoxyanthraquinone () were isolated from the methanol extract of How. roots. Their structural identification was carried out based on the spectroscopic evidence.

Agricultural drought in the Vietnamese Central Highlands at 1-km resolution: Monthly and annual datasets.

Drought is a complex natural hazard which can create significant impacts on society and environment. Given that this phenomenon varies across space and changes over time dependent on various factors (e.g.

A 10-km CMIP6 downscaled dataset of temperature and precipitation for historical and future Vietnam climate.

High-resolution climate projections are mandatory for many applications and impact assessments in environmental and management studies. In response to the needs in Vietnam, this study constructs a new precipitation and temperature daily dataset for Vietnam, at a high spatial resolution of 0.1° × 0.

Natural Cellulose Fiber-Derived Photothermal Aerogel for Efficient and Sustainable Solar Desalination.

Aerogels are becoming a promising platform to fabricate photothermal materials for use in solar steam generation (SSG), which have remarkable application potential in solar desalination, due to their excellent thermal management, salt resistance, and considerable water evaporation rate. In this work, a novel photothermal material is fabricated by forming a suspension between sugarcane bagasse fibers (SBF) and poly(vinyl alcohol), tannic acid (TA), and Fe solutions via hydrogen bonds of hydroxyl groups. After freeze drying, the fabricated SBF aerogel-based photothermal (SBFAP) material possesses a 3D interconnected porous microstructure, which could enhance water transportation ability, reduce thermal conductivity, and quickly dissolve salt crystals on the SBFAP surface.

Factors associated with receipt of informal care among the Vietnamese older persons: Evidence from a national survey.

Background: The rapidly growing older population in Vietnam poses an increasing need for care among the older persons, who have mainly relied on informal care at homes and communities. This study examined the Vietnamese older persons' individual and household factors determining their receipt of informal care.

Methods: This study provided cross-tabulations and multivariable regression analyses to identify who provided assistance to the Vietnamese older people along with their individual and household characteristics.

Stigmastane-type steroid saponins from the leaves of and their -glucosidase and xanthine oxidase inhibitory activities.

Two new vernonioside K () and vernonioside L () and four known Δ stigmastane-type steroidal saponins-vernonioside B2 (), vernoniacum B (), vernonioside B1 (), and vernoamyoside A ()-were isolated from the leaves of . Their structures were determined by comprehensive spectroscopic analysis with one-dimensional nuclear magnetic resonance, two-dimensional nuclear magnetic resonance, and high-resolution mass spectrometry. All isolated compounds (-) were evaluated to determine their inhibitory effects on -glucosidase and xanthine oxidase.

Alpha-Glucosidase Inhibitory Activity of Saponins Isolated from Hance.

Species belonging to the (Asteraceae), the largest genus in the tribe Vernonieae (consisting of about 1,000 species), are widely used in food and medicine. These plants are rich sources of bioactive sesquiterpene lactones and steroid saponins, likely including many as yet undiscovered chemical components. A phytochemical investigation resulted in the separation of three new stigmastane-type steroidal saponins (1 - 3), designated as vernogratiosides A-C, from whole plants of .