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In this research, resorbable phosphate-based glass (PBG) compositions were developed using varying modifier oxides including iron (Fe2O3), copper (CuO), and manganese (MnO2), and then processed via a rapid single-stage flame spheroidisation process to manufacture dense (i.e., solid) and highly porous microspheres. Solid (63–200 µm) and porous (100–200 µm) microspheres were produced and characterised via SEM, XRD, and EDX to investigate their surface topography, structural properties, and elemental distribution. Complementary NMR investigations revealed the formation of Q2, Q1, and Q0 phosphate species within the porous and solid microspheres, and degradation studies performed to evaluate mass loss, particle size, and pH changes over 28 days showed no significant differences among the microspheres (63–71 µm) investigated. The microspheres produced were then investigated using clinical (1.5 T) and preclinical (7 T) MRI systems to determine the R1 and R2 relaxation rates. Among the compositions investigated, manganese-based porous and solid microspheres revealed enhanced levels of R2 (9.7–10.5 s−1 for 1.5 T; 17.1–18.9 s−1 for 7 T) and R1 (3.4–3.9 s−1 for 1.5 T; 2.2–2.3 s−1 for 7 T) when compared to the copper and iron-based microsphere samples. This was suggested to be due to paramagnetic ions present in the Mn-based microspheres. It is also suggested that the porosity in the resorbable PBG porous microspheres could be further explored for loading with drugs or other biologics. This would further advance these materials as MRI theranostic agents and generate new opportunities for MRI contrast-enhancement oral-delivery applications. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is one of the 17 essential plant nutrients, and it is critical for plant metabolism, photosynthesis, and growth. P fertilizers are also critical for crop production and global food security. Type and application method of P fertilizer may lead to increased P accumulation and crop production in the Ganges delta soils. The aim of the present study is to increase the P use efficiency (PUE) by two different P application methods for maize cultivation. The experiment comprised a factorial combination of two methods (broadcasting and furrow placement) and three rates of P fertilizer (36, 48, and 60 kg P/ha). Considering P application methods, furrow placement gave 8.66–27.92% yield benefit over broadcasting method. Maize yield, PUE by crop plant, partial factor productivity, economic efficiency, and P concentration in leaf were remarkably higher in furrow placement than conventional broadcasting method of P application. The furrow placement exhibited higher yield at lower rate of P application (36 and 48 kg P/ha), while no significant changes were observed for grain yield between two methods for high P rate (60 kg/ha). Thus, it is concluded that furrow placement of P application at 36 and 48 kg/ha would give the best grain yield of maize in the Ganges delta floodplain soils. [ABSTRACT FROM AUTHOR]

An effective toxicological assessment of soil-metal bioavailability and plant translocation processes is needed in view of the growing negative impact of trace element pollution on the terrestrial environment and human health. This study was conducted to assess the toxicological processes that regulate the plants' trace element absorption into their tissues, the suitability for human use, the potential sources of trace elements, and the risk to human health, using an integrated research methodology. Soils and sweet potato plants were collected from agricultural fields near the tannery waste disposal sites of Dhaka City, Bangladesh and inductively coupled plasma mass spectrometers (ICP-MS) were used to analyze the essential and toxic elements. The mean concentrations of total elements in soil followed the descending order of Fe > Zn > Mn > Cr > Ni > Pb > Cu > As > Cd and in plant Fe > Zn > Cu > Cr > Ni > Mn > Pb > As > Cd. In the edible tissues of sweet potato, the concentrations of essential and toxic elements exceeded the maximum permissible levels, indicating not safe for human consumption. The translocation factor (TF) revealed that studied elements are more accumulated in the leaves than tubers. The enrichment factor revealed minimal to very high enrichment of essential and toxic elements in the plant parts while the contamination factor showed low to very high contamination. Considering the health risk of toxic elements from plant samples, As and Pb caused non-cancer and cancer risk on human health. However, the present results suggested that regular monitoring of these essential and toxic elements in soil and plants as well as other food materials around the abandoned tannery waste disposal sites are necessary to prevent excessive build-up of these elements in the food chain. [ABSTRACT FROM AUTHOR]

In this paper, the microstructural, optical, thermal, crystallization, and water absorption properties of films prepared from never‐dried (ND) and freeze‐dried (FD) cellulose nanocrystals (CNCs) are reported. Morphology of the ND CNCs reveals a needle‐like structure, while after freeze‐drying, they show a flake‐like morphology. Microstructural analysis of ND and FD CNCs are further studied via small angle X‐ray scattering to probe interactions. ND CNCs yield a transparent film with a low surface roughness (14 ± 4 nm), while the FD CNC film evidence a significant reduction of their transparency due to their higher surface roughness (134 ± 20 nm). Although Fourier transform infrared spectroscopy and energy‐dispersive X‐ray spectroscopy analyses reveal no chemical change occurs during the freeze‐drying process, yet a more intense thermal degradation profile is observed for FD CNC film, probably due to the higher oxygen ingress within the gaps created between the stacked flakes. This, in turn, results in a greater loss of crystallinity at a higher temperature (300 °C) compared to the ND CNC film. A rapid decrease in water contact angle of the FD CNC film proves that the morphology of flakes and their orientation within the film has a strong influence in increasing water absorption capacity. [ABSTRACT FROM AUTHOR]

Varying formulations in the glass system of 40P2O5─(24 − x)MgO─(16 + x)CaO─(20 − y)Na2O─yTiO2 (where 0 ≤ x ≤ 22 and y = 0 or 1) were prepared via melt‐quenching. The structure of the glasses was confirmed by X‐ray diffraction (XRD), Fourier transform infrared (FTIR), micro Raman and solid‐state nuclear magnetic resonance (NMR) spectroscopies. The thermal properties and the activation energy of crystallization (Ec) were measured using thermal analysis and the Kissinger equation, respectively. The glass forming ability of the formulations investigated was seen to decrease with reducing MgO content down to 8 mol% and the glass stability region also decreased from 106 to 90°C with decreasing MgO content. The activation energy of crystallization (Ec) values also decreased from 248 (for 24 mol% MgO glass) to 229 kJ/mol (for the 8 mol% MgO content) with the replacement of MgO by CaO for glasses with no TiO2. The formulations containing less than 8 mol% MgO without TiO2 showed a strong tendency toward crystallization. However, the addition of 1 mol% TiO2 in place of Na2O for these glasses with less than 8 mol% MgO content, inhibited their crystallization tendency. Glasses containing 8 mol% MgO with 1 mol% TiO2 revealed a 12°C higher glass transition temperature, a 14°C increase in glass stability against crystallization and a 38 kJ/mol increase in Ec in comparison to their non TiO2 containing counterpart. NMR spectroscopy revealed that all of the formulations contained almost equal percentages of Q1 and Q2 species. However, FTIR and Raman spectroscopies showed that the local structure of the glasses had been altered with addition of 1 mol% TiO2, which acted as a network modifier, impeding crystallization by increasing the cross‐linking between phosphate chains and consequently leading to increased Ec as well as their glass forming ability. [ABSTRACT FROM AUTHOR]