Publications by authors named "Van M Dinh"

High lead (Pb) levels in cassia products pose a significant threat to both the global spice supply chain and public health. Addressing this critical issue, our study investigates Pb accumulation within the soil-cassia system in Northern Vietnam, a major cassia-producing region. Soil and cassia samples were collected from six key cassia-growing regions along the Red River, and their compositions and properties were systematically evaluated.

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A highly efficient method for the direct construction of amide bonds a selective cleavage of C-H and C[double bond, length as m-dash]C bonds in indole structures using an iodine-promoted approach was developed. Mechanistic studies indicated the formation of superoxide radicals obtained from molecular oxygen activation as a key intermediate step, which provided a precursor for subsequent oxidative ring-opening and intermolecular cyclization. A broad range of quinazolin-4(3)-ones and tryptanthrins were synthesized in moderate to good yields under mild and environmentally benign conditions.

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Arsenic (As) turnover in rice paddy agro-ecosystems has received much attention because As can enter the food chain through its accumulation in rice, thereby affecting human health. Returning straw to soil is a common practice to retain nutrients for soil and crops, but it also cycles As within the rice paddy field ecosystems. However, there is still a lack of detailed understanding of the fate of As in rice straw, and how or to what extent it is recycled back into the soil environment.

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The mobilization of arsenic (As) in paddy soil has received much attention because it might accelerate the transfer of As from soil to rice. This study aims to elucidate whether earthworms can mobilize As through their casts. Cast samples were collected from 23 different paddy fields in the Red River delta.

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Cellulose fiber rejects from industrial-scale recycling of waste papers were dried and de-ashed using a combined cyclone-drying and sieving process. The upgraded fiber reject was used as a component of substrates for the cultivation of and mushrooms. Acetic acid (AA) and acid whey (AW) were used to adjust the pH of fiber reject-based substrates.

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The increasing daily use of cosmetic and personal care ingredients (CPCIs) requires improved understanding of the fate and impacts of CPCIs in environmental systems. Effects of CPCIs on colloidal properties of various geocolloids such as iron oxides (goethite, haematite), clay minerals (kaolinite, bentonite) and soil clays (kaolinitic-, illitic- and lateritic soil clays) were studied by tracking time-resolved changes in zeta potential (ζ) and observing suspended particle density. Two polymers representing anionic CPCIs, i.

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Colloid-sized microplastics (MPs) are ubiquitous in aquatic environments and can share the same transport route together with various crystalline, poorly crystalline and freshly formed iron oxides. However, the colloidal interactions between these colloid constituents are not fully understood. This study was designed to investigate the colloidal properties of polystyrene microplastics (PSMPs) under the influence of haematite, goethite, ferrihydrite and freshly formed Fe oxide (FFFO).

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Polymer ingredients are commonly found in personal care and cosmetic industry and their "leakages" into the environment have recently been warned as an emerging environmental risk. Daily use of personal care and cosmetic products can inadvertently release large amounts of polymer ingredients into water courses. However, their fate and interaction with other constituents, especially colloids (e.

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