Groundwater with an excessive level of Arsenic (As) is a threat to human health. In Bangladesh, out of 64 districts, the groundwater of 50 and 59 districts contains As exceeding the Bangladesh ...(50 μg/L) and WHO (10 μg/L) standards for potable water. This review focuses on the occurrence, origin, plausible sources, and mobilization mechanisms of As in the groundwater of Bangladesh to better understand its environmental as well as public health consequences. High As concentrations mainly was mainly occur from the natural origin of the Himalayan orogenic tract. Consequently, sedimentary processes transport the As-loaded sediments from the orogenic tract to the marginal foreland of Bangladesh, and under the favorable biogeochemical circumstances, As is discharged from the sediment to the groundwater. Rock weathering, regular floods, volcanic movement, deposition of hydrochemical ore, and leaching of geological formations in the Himalayan range cause As occurrence in the groundwater of Bangladesh. Redox and desorption processes along with microbe-related reduction are the key geochemical processes for As enrichment. Under reducing conditions, both reductive dissolution of Fe-oxides and desorption of As are the root causes of As mobilization. A medium alkaline and reductive environment, resulting from biochemical reactions, is the major factor mobilizing As in groundwater. An elevated pH value along with decoupling of As and HCO3− plays a vital role in mobilizing As. The As mobilization process is related to the reductive solution of metal oxides as well as hydroxides that exists in sporadic sediments in Bangladesh. Other mechanisms, such as pyrite oxidation, redox cycling, and competitive ion exchange processes, are also postulated as probable mechanisms of As mobilization. The reductive dissolution of MnOOH adds dissolved As and redox-sensitive components such as SO42− and oxidized pyrite, which act as the major mechanisms to mobilize As. The reductive suspension of Mn(IV)-oxyhydroxides has also accelerated the As mobilization process in the groundwater of Bangladesh. Infiltration from the irrigation return flow and surface-wash water are also potential factors to remobilize As. Over-exploitation of groundwater and the competitive ion exchange process are also responsible for releasing As into the aquifers of Bangladesh.
•Intensive land use, agrochemicals usage and irrigation are responsible for high As.•Elevated As concentrations mainly occurred in shallow Holocene alluvial aquifers.•Strong reducing condition and moderate alkalinity facilitated As release process.•Evaporation was not an important factor responsible for As enrichment.•As is mobilized in biogeochemical and reduction environment with ion exchange process.
The molecular structure of (E)-2-(butan-2-ylidene)hydrazinecarbothiomide (2-butanone thiosemicarbazone) was validated by density functional theory (DFT) calculations. The characterization of the ...ligand was done using various spectroscopic techniques. Four transition metal complexes were prepared with the ligand and their antioxidant activity was tested. Molecular docking studies of the complexes were also performed against nicotinamide adenine dinucleotide phosphate (NADPH) and myeloperoxidase (MPO). Structure validation of the ligand was done in Gaussian 09 software. The geometry optimization was done at B3LYP/6-31G++(d,p) level. The 1H and 13C NMR chemical shifts, FT-IR vibrations and UV–visible transitions were validated with the help of theoretical calculations. The frontier molecular orbital analysis, molecular electrostatic potential (MEP) and global reactivity descriptors were calculated to predict the stability of the molecule. Non-linear optical (NLO) properties were assessed and compared with urea. Natural bond orbital (NBO) analysis was done to predict the stability of the ligand resulting from hyper conjugative interactions and electron delocalization. Molecular docking studies of the complexes were performed with iGEMDOCK 2.1 and AutoDock 4.2.6.Antioxidant potential was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) Assay. 1H and 13C correlation coefficients (R2) were 0.9964 and 0.9974 respectively. In case of FT-IR, the correlation coefficient (R2) was 0.9984. Fe(C5H11N3S)2(SO4) possessed maximum antioxidant potential followed by Cu(C5H11N3S)2(SO4). Molecular docking findings suggested that the Fe complex released the minimum binding energy. Computational structure validation is an important aspect in finding a lead moiety. The theoretical spectral findings correlated well with the experimental findings in the present study. The metal complexes showed appreciable antioxidant potential as predicted by the computational and experimental findings. The ligand possessed better NLO properties than urea.
The current study investigates the potential for topical delivery of a fluticasone propionate (FP) and levocetirizine dihydrochloride (CTZ)-loaded microemulsion (ME) for the management of atopic ...dermatitis. Various microemulsion components were chosen based on their solubility and emulsification capabilities, and the ternary phase diagram was constructed. A total of 12 microemulsion formulations were screened for various attributes like vesicle size, polydispersity index, ζ-potential, percent transmittance, density, and pH. The average globule size and ζ-potential of FP and levocetirizine-containing ME were 52.12 nm and −2.98 ζ-potential, respectively. Transmission electron microscopy confirmed the spherical nature of the globules. The developed system not only controlled the release of both drugs but also enhanced the efficacy of the drugs on a rodent model. Histopathological studies confirmed the safety of the developed system. The present findings provide evidence for a scalable and simpler approach for the management of atopic dermatitis.
Limited availability of phosphorus (P) in agricultural soils is a major cause of poor growth and yield of crops throughout the world. Optimization of crops productivity can be achieved by increasing ...the bioavailability of P via phosphate solubilizing bacteria (PSB), however, their effectiveness may vary with changing agro-climatic conditions That’s why current experiment was conducted to evaluate the potential of phosphate solubilizing bacteria (with PSB and without PSB) in improving growth and yield of wheat under different P levels (0, 25, 50, and 100 % of recommended P). The PSB with 100% recommended P significantly enhanced wheat tillers m−2, grains spike-1, grains and biological yield compared to the rest of the treatment’s combination. A significant improvement in 100 grains weight and rate of photosynthesis also validated the efficacious functioning of PSB and full recommended P. Furthermore, PSB were effective in optimizing wheat yield attributes at respective P level compared to Without PSB. Our findings imply that, PSB application along with 100% recommended P as inorganic phosphorus has potential to enhance wheat growth and yield over sole application of P fertilizers or PSB.
Cancer being a genetically heterogeneous and complex disease and the available therapies are not very effective, rendering them the predominant cause of mortality across the world. The discovery of ...new anticancer drugs with higher efficacy and milder side effects is a great challenge for health professionals.
The current study focused on the anticancer potential of two known dimeric napthoquiones, diospyrin (1) and 8-hydroxydiospyrin (2) isolated from the roots of Diospyros lotus.
In vitro Epstein-Barr-Virus (EVA) an early antigen activation assay was used to evaluate the antitumor potential of tested compounds followed by a two-stage carcinogenesis assay on mouse skin for anti-carcinogenic effect. Compounds were also assessed for their multidrug resistance reversal potential. The in vitro heatinduced protein denaturation assay was used for the anti-inflammatory effect of the tested compounds.
Both compounds evoked marked cytotoxic activity with IC
of 47.40 and 36.91 ppm, respectively. In Epstein-Barr-Virus (EVA) early antigen activation assay compounds 1 and 2 showed IC50 values of 426 ppm and 412 ppm, respectively. The tested compounds showed 60% survival rate of the lymphoblastoid Raji cells at a concentration of 1000 (mol / ratio 32 pmol TPA). In a two-stage carcinogenesis assay on mouse skin, both compounds significantly delayed the formation of papillomas on mouse skin. Compound 1 showed 50% effect at 14th week, whereas compound 2 exerted the same effect at 13th week, while both provoked 100% effect at 20th week. Both compounds significantly attenuated thermal-induced protein denaturation with EC50 values of 298 and 264 μg/mL, respectively. The dimeric napthoquiones were evaluated for their effects on the reversion of Multidrug-Resistant (MDR) cell lines mediated by P-glycoprotein using rhodamine 123 dye-based exclusion screening test on human mdr1 gene transfected thymic lymphoma L5178 cell line. The compounds 1 and 2 exhibited promising MDR reversal effect in a dose-dependent manner against mouse T-lymphoma cell line. Docking results also showed that both compounds have good docking statistics as compared with standard.
Both the compounds demonstrated marked anti-tumor, anti-carcinogenic, and MDR reversal effects with significant attenuation of thermal-induced denaturation of the protein. These compounds may explain the traditional uses of D. lotus which might be effective anticancer agents.
Nitrogen (N) deficiency is a very common problem of alkaline soils. Incorporation of organic residues with urea could be promising practice for improving soil properties and crop yield. This study ...was aimed, to evaluate the responses of two maize cultivar (Azam and Jalal) to organic wastes and Urea (sole organic residues i.e. seed cake (SC), poultry manure (PM), press mud (PrM) and mineral nitrogen (urea) and their combinations with urea (25%, 50% or 75%) applied at 150 kg N ha
−1
under field conditions. Significant differences were recorded for leaf area index, plant height, number of grains ear
−1
, 1000 grain weight, biological and grain yield to N sources. Maize cultivar Jalal performed significantly better than Azam for all tested traits. The performance of both cultivars was significantly better when N was applied as either SC/PM with urea at 25:75, SC and PM with urea at 25:25:50, 100% sole urea, SC/PrM with urea at 50:50, or all organic N sources (25%) with urea (75%). Integration of organic wastes with urea gave the higher maize yield however, it was similar to the yield obtained from sole urea but due to allied environmental and health hazards, the sole use of urea could not be encouraged.
The present study was focused on the optimized biodiesel production using
Moringa oleifera
(
M. oleifera
) and rice bran oils, characterization, and comparative evaluation of the exhaust emission ...profile using artificial and natural additives resulting from synthesized biodiesel. Furthermore, various biodiesel blends (B10, B20, B50, and B100) of
Moringa oleifera
(
M. oleifera
) and rice bran oils were studied in a four-cylinder, direct injection engine at different engine speeds (1800–3000 rpm). The optimal yields (%) for both the
M. oleifera
and rice bran oil-based biodiesel were found to be 87 ± 2.0 and 93 ± 2.6%, respectively, using sodium methoxide as the catalyst. The optimized reaction parameters involved in the transesterification of the
M. oleifera
and rice bran oils were revealed to be catalyst concentration (1.25%), methanol-to-oil molar ratio (9:1), reaction temperature (60 °C), and reaction time (90 min). The fuel properties of the
M. oleifera
and rice bran oil-based biodiesel were found to be in compliance with ASTM D6751 and EN 14214. The exhaust emission levels of the synthesized biodiesel and its blends with conventional diesel showed a significant reduction in the particulate matter and carbon monoxide levels comparative to the fossil fuel-based diesel combustion, whereas an increasing trend was observed in case of the oxides of nitrogen (NO
x
) emission. The results of the engine performance test indicated that the brake power in all of the samples had approximately similar values for each load and the enriched blends showed a distinct improvement in brake-specific fuel consumption. The effect of antioxidants on the NO
x
emission levels resulting from the combustion of the biodiesel and its blends showed that the synthetic additives (butylated hydroxyl anisole (BHA), butylated hydroxyl toluene (BHT), t-butyl hydroquinone (TBHQ), and propyl gallate
(
PG)) were more effective than the natural methanolic antioxidant extracts (extract of
P. pinnata
(EPPL), extract of
A. lebbeck
(EPPL), extract of
P. guajava
(EPG), and extract of
M. azedarcah
(EMA) for reduction in the NO
x
emission level.
•NaCl-induced salt stress drastically affected the metabolic profile of the Tagetes erecta L. plants.•Besides reactive oxygen species (ROS), methylglyoxal (MG) equally contributed to salinity-induced ...oxidative stress.•Lower concentration of cobalt (C1; 10mg/L) resulted in the enhancement of the tolerance against salinity stress tolerance in Tagetes erecta L.•Interestingly, higher concentration of cobalt (C1; 20mg/L) further induced the oxidative damage under higher salinity conditions rather than rescuing the plants.•Glutathione played a crucial role in ROS- and MG-detoxification in plants under stress.
Salinity is a major concern globally and causing reduction in crop growth and development thereby lowering food production. Interestingly, cobalt (Co), a multifunctional non-essential micro-element, has an important role in improving growth and development under salinity stress. In the current study, the effects of Co on the morphological, biochemical, nutritional, and metabolic changes of African marigold plants at two salinity levels were assessed. Two concentrations of Co (C1; 10 mg/L and C2; 20 mg/L) were applied as foliar application to the marigold plants under salinity (S1; 300 mM and S2; 600 mM) stress. The results indicated that salinity substantially reduced the growth by negatively affecting the nutritional and metabolic profile. Interestingly, the C1 application mitigated the salinity effects and improved all the studied parameters including vegetative, nutritional, biochemical and metabolites (amino acids, fatty acids, organic acids, sugars, carotenoids, flavonoids, and terpenoids) by reducing the reactive oxygen species (ROS) and methylglyoxal (MG)-induced oxidative stress, at two salinity levels. The overall results revealed that C1was an ideal dose for marigold plants undergoing salinity stress since C2 application showed some toxicity symptoms under both the salinity levels; with reduced growth and impaired development. Based on the observations, the two different oxidative stress scavenging pathways in marigold are discussed i.e. ROS-scavenging by ascorbate-glutathione (AsA-GSH) cycle and the MG-detoxification by glyoxalase. With the limitations imposed upon the glutathione (GSH) pool size and redox homeostasis, the study indicated that GSH played a critical role in both ROS- and MG-detoxification in marigold plants at both salinity levels.
Display omitted
•The δ-MnO2/N-rGO nanocomposite (MNGC) has been synthesized by a simple template-free hydrothermal approach.•LSV results of MNGC showed improved ORR performance as compared to MnO2 and N-rGO in terms ...of the onset potential, half wave potential and limiting current.•The MNGC electrode displayed superior cyclic performances of lithium air battery with stable specific capacity, decreased overpotential, reversibility and rate capability.•The Li-O2 battery was also tested with MNGN electrode for limited discharge capacity of 500 m Ah/g; long-term cycling was achieved without any electrolyte degradation.•As, high specific capacity of 5250 mAh /g was obtained even with high current density of 0.2 mA /cm2.
Among all the electrocatalysts for Lithium-Air battery (Li-air), Platinum Pt is the best performing cathode material. However, the high cost of noble Pt metal and scarcity nature impedes the use of Pt-based catalysts from being extensivity used in commercial applications. Therefore, there is an urgent need to develop an efficient and cost-effective alternate electrocatalyst to replace Pt-based materials in lithium-oxygen (Li-O2) battaries. In the present work, δ-MnO2/N-rGO composite (MNGC) has been synthesized by a simple non-template hydrothermal approach. MNGC with a porous wall structure composed of ultrathin nanosheets exhibits excellent electrochemical properties for oxidation–reduction reaction (ORR). MNGC can provide numerous pathways for abundant oxygen and electrolyte access to facilitate the mass transfer of lithium-ion. Such a well-designed structure offers the right electrocatalyst for the air cathode in lithium-oxygen (Li-O2) battaries. The prepared samples principal characteristics are analyzed, which verified the successful synthesis of sheet-like δ-MnO2 grown over the surface of nitrogen-doped reduced graphene oxide (N-rGO). Linear sweep voltammetry (LSV) results of MNGC showed enhanced ORR performance compared to MnO2 and N-rGO in terms of the half-wave potential, limiting current, and onset potential. MNGC electrode displayed superior cyclic performances of Li-air with a stable specific capacity, decreased overpotential, reversibility, and rate capability. Li-O2 battery was also tested with MNGN electrode for limited discharge capacity of 500 mAh/g, long-term cycling was achieved without electrolyte degradation. A high specific capacity of 5250 mAh/g was obtained at a high current density of 0.2 mA/cm2. The interlinked effect of δ–MnO2 and N–rGO for supporting the electrochemical interaction between O2 and Li is explained for improved columbic and energy efficiency of Li–O2 battery
PurposeIn the past, a plethora of studies has investigated the organizational and individual outcomes of high-performance work systems (HPWS). However, less is known about the mechanism through which ...HPWS impacts employees’ behavior, particularly intrapreneurial behavior (IB). Drawing on the social exchange theory, this study aims to fill this gap by investigating the mediation effect of perceived organizational support (POS) on HPWS-IB linkages.Design/methodology/approachData were collected with the help of structured questionnaires from employees working in service industries such as banking and insurance.FindingsHPWS was conceptualized as a higher-order measurement model that includes four lower-order dimensions, namely, information sharing, decision-making participation, job security, training and development. Partial least squares structural equation modeling technique was used to test the hypothesized relationships. Results showed a positive and significant effect of HPWS on IB. Moreover, POS significantly mediated the HPWS-IB link.Originality/valueDespite an increasing number of studies on the role of human resource management (HRM) practices in enhancing innovation and creativity, there has not been enough research on how HPWS affects IB at the individual level in the presence of POS. Thus, this research is the first of its kind to investigate the mediating role of POS in HPWS-IB linkages in the Malaysian context.
PDF
