Recent publications
The Shitalakshya River, vital to the Dhaka district, faces severe pollution challenges due to industrial discharges, urban runoff, and other anthropogenic activities. This study investigated the concentration of polycyclic aromatic hydrocarbons (PAHs) and heavy metals in the river water, utilizing GC–MS/MS and ICP-MS techniques. The results revealed a total PAH concentration ranging from 4.97 to 5.87 ng/mL, with 3-ring PAHs being the most prevalent. Heavy metals such as Fe, As, Ni, and Zn were found in significant concentrations, exceeding international standards for drinking water and aquatic life. The ecological risk assessment identified benzo(b)fluoranthene, benzo(k)fluoranthene, and indeno(1,2,3-cd)pyrene as the highest threats to aquatic organisms. Health risk assessments indicated substantial risks from dermal and ingestion exposures, particularly due to arsenic, highlighting potential long-term health implications for local residents. The study underscores the urgent need for comprehensive monitoring, pollution source identification, and stringent regulatory measures to mitigate these risks.
Air pollution is a substantial threat to both human health and plant life. While there has been plenty of study on the effects of air pollution on human health in Dhaka, the influence on plants in this urban environment has yet to be investigated. This study investigated the heavy metal content (Pb, Cd, Cr, Cu, Ni, Zn, Fe, and Mn) in various plant species to elucidate the effects of air pollution on vegetation. Samples of soil and corresponding plant leaves from Mangifera indica (Mango tree), Swietenia mahagoni (Mahogany tree), Polyalthia longifolia (Ashoka tree), Ficus religiosa (Fig tree), and Artocarpus heterophyllus (Jackfruit tree) were collected from industrial, traffic, and control location in Dhaka city. Concentrations of heavy metals in both soil and leaves were analyzed, and the geoaccumulation index, contamination factor, and transfer coefficient were calculated to assess the correlation between metal concentration and air pollution impact. At traffic locations, lead (Pb) and zinc (Zn) concentrations ranged from 2605 to 4289 mg/kg and 35 to 1157 mg/kg, respectively. In industrial areas, chromium (Cr) and copper (Cu) concentrations varied from 386 to 954 mg/kg and 27 to 458 mg/kg, surpassing World Health Organization recommended limits. Pb and Cr exhibited the highest geo-accumulation index. Traffic sites demonstrated the highest Pb transfer coefficients across plant species. This study is very significant as it provides important understandings for urban planning and environmental management, highlighting the adverse effects of pollution on plant species in Dhaka.
Graphical Abstract
In this study, dissolving pulp from hardwood, Trema orientalis L. was used as cellulose pulp for the synthesis of cellulose acetate (CA). CA was prepared by varying time of swelling with acetic acid, duration of reaction and temperature of reaction. The degree of substitution (DS) of all prepared CA was higher than 2.5, indicating the formation of cellulose triacetate (CTA). The maximum yield of CTA was 157 wt-% after 3 hours of cellulose pulp swelling followed by a 1.5-hour acetylation reaction at 35 °C. The all prepared CA samples showed good solubility in dimethyl sulphoxide (DMSO), N,N-dimethyl formamide (DMF) and tetrahydrofuran (THF). The creation of strong absorption band at 1740 cm ⁻¹ for carbonyl (–C=O) group confirms successful acetylation reaction. The cellulose crystallinity diminishes as the acetylation progresses as observed by X-ray diffraction (XRD). The prepared CA samples were also characterised using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic viscosity measurements. The CA/DMSO solutions exhibited shear thinning property at lower shear rate and higher operating temperature. Increased dynamic viscosity was observed with the increase in concentration of CA in the DSMO solvent. The crystallinity and thermal stability of CA samples was highly influenced by the duration of acetylation and temperature of reaction.
Type 2 diabetes mellitus (T2DM) and Alzheimer’s disease (AD) have similar clinical characteristics in the brain and islet, as well as an increased incidence with ageing and familial susceptibility. Therefore, in recent years there has been a great desire for research that elucidates how anti-diabetic drugs affect AD. This work attempts to first elucidate the possible mechanism of action of DPP-IV inhibitors in the treatment of AD by employing techniques from network pharmacology, molecular docking, molecular dynamic simulation, principal component analysis, and MM/PBSA. A total of 463 targets were identified from the SwissTargetPrediction and 784 targets were identified from the SuperPred databases. 79 common targets were screened using the PPI network. The GO and KEGG analyses indicated that the activity of DPP-IV against AD potentially involves the hsa04080 neuroactive ligand-receptor interaction signalling pathway, which contains 17 proteins, including CHRM2, CHRM3, CHRNB1, CHRNB4, CHRM1, PTGER2, CHRM4, CHRM5, TACR2, HTR2C, TACR1, F2, GABRG2, MC4R, HTR7, CHRNG, and DRD3. Molecular docking demonstrated that sitagliptin had the greatest binding affinity of -10.7 kcal/mol and established hydrogen bonds with the Asp103, Ser107, and Asn404 residues in the active site of the CHRM2 protein. Molecular dynamic simulation, PCA, and MM/PBSA were performed for the complex of sitagliptin with the above-mentioned proteins, which revealed a stable complex throughout the simulation. The work identifies the active component and possible molecular mechanism of sitagliptin in the treatment of AD and provides a theoretical foundation for future fundamental research and practical implementation.
Air pollution in megacities is a global concern. This research aimed to identify sources of fine particulate matter (PM2.5) and PM2.5-bonded heavy metals in Dhaka and assess their potential health effects. An active air sampler was used to collect PM2.5, and one-fourth of it was digested in nitric/perchloric acids to analyze heavy metals using an atomic absorption spectrophotometer. Results of 24-hour average PM2.5 mass was calculated as 154.8±46.1 μg/m3, which is three times higher than Bangladesh standard (65.0 μg/m3) and ten times higher than WHO guideline (15.0 μg/m3). Chromium was found to be nearly twice than that WHO guideline. Positive matrix factorization suggests possible sources of PM2.5-bound heavy metals due to emissions from vehicles, industries, and solid waste combustion. Pearson’s correlation matrix results reveal strong correlations between Cu-Fe, and Zn-Fe (p < 0.01), while significant correlations are found between Fe-Cr, Zn-Cu, Pb-Cr, Pb-Zn, and Pb-Cd (p < 0.05) indicating a common source. Hazard quotient and hazard index data demonstrated a degrading state of PM2.5-bound heavy metals for non-carcinogenic health risk for adult group, where hazard quotient values for ingestion were higher than those for inhalation and dermal routes. Except for Cr, which was higher for both adult and children groups, lifetime cancer risk values were found to be within an allowable range, implying that PM2.5-bound heavy metals did not pose a significant risk of cancer to human health. This study emphasizes an urgent need for comprehensive air pollution management strategies to protect atmospheric environment and public health in Dhaka city.
Microplastics (particles smaller than 5 mm) are among the most common pollutants in aquatic habitats because they may develop to high densities and can interact with both the abiotic and biotic environments. There is less information available on microplastics in the freshwater systems than there is in the marine environment. This study aims to shed light on the abundance and spatial distribution of microplastics in the Brahmaputra River (Mymensingh) through the utilization of the wet peroxide oxidation isolation technique, supplemented with sodium chloride, to examine fish and sediment specimens collected between December 21, 2022 and January 12, 2023. A total of 26 and 189 microplastic particles were identified in the fish and sediment samples, respectively. Microplastics (MPs) concentrations in fish gut ranged from 0.5 ± 0.7 to 1.67 ± 0.58 MPs individual ⁻¹ . The most prevalent shape found in fish stomachs was fiber (46%), and the most common color was transparent (32%). Sizes 0.5–1 mm (1.6 ± 0.74) had the most microplastics. This study found that fishes from the demersal (3.25 ± 1.7) zone had more MPs than the benthopelagic (2.5 ± 0.58) and pelagic (1.5 ± 0.7) zones. Omnivorous fishes (54%) consumed more microplastics than carnivorous (31%, 2.6 ± 0.58) and herbivorous fishes (15%,1.33 ± 0.94). Microplastic consumption had a moderate correlation with fish body weight (r = 0.34), length (r = 0.46), and gastrointestinal content (r = 0.45). The MPs per kilogram of Brahmaputra River bed sediment ranged from 8 to 31, with a mean abundance of 18.9 ± 7.01 particles kg ⁻¹ . The most common shape identified in this study was fragments (52%) and 33% of sediment microplastics were blue in color. Microplastics were most abundant in the 1–3 m‐meter size class. Fourier transform infrared spectroscopy (FTIR) showed that polypropylene (PP) was the most prevalent MP in both fish (34%) and sediment (40%) samples. In this study, the Pollution load index (PLI) for each sampling site is <10, with the highest value found for station 2(1.97 ± 0.49), regarded as risk category I. This study's results will be useful for future research on microplastics in freshwater environments.
Practitioner Points
Abundance and distribution of microplastics were determined from the longest river of Bangladesh.
The structural properties of microplastics were characterized using ATR‐FTIR spectroscopy.
Pollution load index (PLI) of microplastics was investigated .
This research focuses on the fabrication of novel ternary g-C3N4/Zn0.5Ni0.5Fe1.8Mn0.2O4/rGO hybrid nanocomposites (NCs) for humidity sensing applications. The integration of carbon based two dimensional (2D) materials reduced graphene oxide (rGO),...
The black soldier fly (BSF) is an efficient converter of residual biomasses into valuable product molecules and biomolecules. It has attained significant consideration for sustainable resource recovery and waste management. Chitin was extracted, isolated and purified from BSF (Yield 15%) and was characterized using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Two fractions were obtained by sieving and the 100-mesh sample showed a crystallinity index of 9.32% which indicates that this BSF chitin sample falls into the amorphous category. Thermogravimetric analysis (TGA) evaluated chitin's thermal properties, scanning electron microscopy (SEM) examined its surface morphologies, and energy-dispersive X-ray spectroscopy (EDX) performed elemental analysis. Moreover, density functional theory (DFT) calculations were conducted to investigate the molecular geometry and infrared vibrational properties of N-acetyl-D-glucosamine monomer and its conceptual dimeric and trimeric chitin sub-units.
The increasing production and improper disposal of plastic waste present a major global environmental challenge, highlighting the need for sustainable solutions. This review thoroughly examines the use of waste plastics in composite material production, providing a dual benefit: reducing environmental impact while creating valuable materials. This review examines the scale and ecological impact of plastic waste, focusing on various types of waste plastics, such as thermoplastics and thermosets. In-depth discussion includes various processing techniques such as melt blending, compression molding, extrusion, and injection molding. The review discusses various reinforcing materials used with waste plastics, including other polymers, natural and synthetic fibers, sand, clay, fly ash, and additional recycled materials. The focus is on analyzing mechanical, thermal, physical, and chemical properties, considering factors like waste plastic-type, reinforcement type, processing parameters, and additives. This review serves as a valuable resource for researchers, engineers, and policymakers aiming to find sustainable solutions for plastic waste management and to promote a circular economy.
The detrimental effects of cadmium (Cd), a hazardous heavy metal, on fish have triggered global concerns. While the ecotoxicity of Cd on fish has been investigated, the impact of Cd on muscle quality and its correlation with the gut microbiota in fish remains scarce. To comprehensively uncover Cd effects based on preliminary muscle Cd deposition, relevant studies, and ecological Cd pollution data, we exposed Labeo rohita to Cd under concentrations of 0.00 (control), 0.05, and 0.40 mg/L for 30 days and assessed fish health, muscle quality, and intestinal bacterial diversity. We observed significant Cd bioaccumulation in the fish muscle and intestine at 0.40 mg/L treatment, adversely impacting fish health with lower growth indices, higher mortality, behavioral aberrations, and clinical anomalies. More interestingly, Cd exposure decreased muscle quality by reducing nutrient levels, including fat, protein, iron, zinc, mono and polyunsaturated fatty acids, and increasing free amino acids and saturated fatty acids. Elevated oxidative stress markers, including total superoxide dismutase (T-SOD), catalase (CAT), and hydrogen peroxide (H2O2), were detected in the muscles, indicating degraded quality as a result of damage to cellular structures including proteins, lipids, and DNA. Simultaneously, we found Cd exposure altered fish intestinal microbial diversity, impairing muscle nutrient assimilation, thereby influencing muscle quality. Functional predictions suggested a decrease in pathways related to fermentation and chemoheterotrophy in the exposed groups. Overall, this study highlights how Cd toxicity jeopardizes fish health and deteriorates muscle quality which needs to be addressed for human benefit.
Graphical Abstract
In this study, polycrystalline BaZrxTi1−xO3 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) ceramics were synthesized through a solid-state reaction technique. The effect of zirconium doping on the properties of barium titanate (BaTiO3) was investigated by various characterization tools. The structural and morphological properties of the synthesized materials were studied by X-ray diffraction (XRD), Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM). The electrical properties of the Zr-doped BaTiO3 (BZT) materials were examined by impedance spectroscopy and the optical properties were investigated using UV-Vis-NIR spectroscopy. The XRD analyses of the prepared BZT materials revealed a single-phase tetragonal structure. The inclusion of Zr⁴⁺ in the BT matrix did not significantly affect the Raman-active modes, suggesting that the tetragonal crystal structure was retained in the as-synthesized samples. FE-SEM analyses revealed that the grain size initially increased from 49.36 nm to 53.24 nm for x = 0.05 wt% and then decreased gradually for higher concentrations up to x = 0.15 wt% (26.99 nm). The dielectric constant, dielectric loss, conductivity, and quality factor determined from the impedance data demonstrated that Zr⁴⁺ addition significantly influenced the electrical properties of BT. The band gap energy, Eg, of the synthesized samples were found in the range of 3.19–3.37 eV, which was calculated from the diffuse reflection data. The experimental results suggest that the BZT ceramic materials are suitable for energy storage device applications.
The gram-negative, facultative anaerobic bacterium Morganella morganii is linked to a number of illnesses, including nosocomial infections and urinary tract infections (UTIs). A clinical isolate from a UTI patient in Bangladesh was subjected to high-throughput whole genome sequencing and extensive bioinformatics analysis in order to gather knowledge about the genomic basis of bacterial defenses and pathogenicity in M. morganii. With an average nucleotide identity (ANI) of more than 97% similarity to a reference genome and phylogenetic analysis verified the isolate as M. morganii. Genome annotation identified 3,718 protein-coding sequences, including genes for metabolism, protein processing, stress response, energy, and membrane transport. The presence of biosynthetic gene clusters points to the isolate’s ability to create bioactive compounds, including antibiotics. Genomic islands contained genes for metal transporters, stress proteins, toxin proteins, and genes related to horizontal gene transfer. The beta-lactam resistance gene blaDHA was found using antimicrobial resistance (AMR) gene analysis across three databases. The virulence genes kdsA and cheY, which may be involved in chemotaxis and lipopolysaccharide production, were also available in the isolate, suggesting its high pathogenicity. The genome contained mobile genetic components and defense mechanisms, such as restriction modification and CRISPR-Cas systems, indicating the bacterium’s ability to defend itself against viral attacks. This thorough investigation sheds important light on M. morganii’s pathogenicity and adaptive tactics by revealing its genetic characteristics, AMR, virulence components, and defense mechanisms. For the development of targeted treatments and preventing the onset of resistance in clinical care, it is essential to comprehend these genetic fingerprints.
Streptococcus pneumoniae (SPN) is a significant pathogen causing pneumonia and meningitis, particularly in vulnerable populations like children and the elderly. Available pneumonia vaccines have limitations since they only cover particular serotypes and have high production costs. The emergence of antibiotic-resistant SPN strains further underscores the need for a new, cost-effective, broad-spectrum vaccine. Two potential vaccine candidates, CbpA and PspA, were identified, and their B-cell, CTL, and HTL epitopes were predicted and connected with suitable linkers, adjivant and PADRE sequence. The vaccine construct was found to be antigenic, non-toxic, non-allergenic, and soluble. The three-dimensional structure of the vaccine candidate was built and validated. Docking analysis of the vaccine candidate by ClusPro demonstrated robust and stable binding interactions between the MEV and toll-like receptor 4 in both humans and animals. The iMOD server and Amber v.22 tool has verified the stability of the docking complexes. GenScript server confirmed the high efficiency of cloning for the construct and in-silico cloning into the pET28a (+) vector using SnapGene, demonstrating successful translation of the epitope region. Immunological responses were shown to be enhanced by the C-IMMSIM server. This study introduced a strong peptide vaccine candidate that has the potential to contribute to the development of a rapid and cost-effective solution for combating SPN. However, experimental verification is necessary to evaluate the vaccine’s effectiveness.
In modern agriculture, the enzymes inhibition by chemical agents and environmental pollutants accounts for a significant threat to crop health and productivity. Enzymes play a crucial role in maintaining homeostasis in the metabolic processes that sustain life. Understanding what regulates enzyme activity is crucial for many scientific and industrial endeavors. The purpose of this research work was to examine how different chemical agents, and metallic salts affected the activity of two important food enzymes like α-amylase and protease in barley. These studies compared the effects of several chemical treatments applied to barley seeds, including urea, ethylenediaminetetraacetic acid (EDTA), acetic acid, and a wide range of metallic salts. To determine the impact of each chemical on the stability of α-amylase and protease enzyme activity using standard assay procedures. The activities of α-amylase and protease were inhibited by increasing urea concentration, eventually eliminating them at 8 M urea. The enzymes lost their activities completely at 0.50 M EDTA. Treatment with higher acetic acid concentrations decreased their activities, but they retained 20.46 ± 1.06 % and 17.38 ± 1.09 % after treating with 20 % acetic acid. The application of CaCl2 led to a progressive increase for both the enzyme activities, but the maximum increases were observed 137.26 ± 1.42 % and 135.65 ± 1.17 % due to 0.50 M Ca²⁺. In the presence of Mn²⁺ and Mg²⁺ salts, enzyme activity increased notably. In contrast to K⁺ and Na⁺, which have negligible or no inhibitory effects but Zn²⁺, Cu²⁺, and Fe²⁺ considerably reduce the activity of both enzymes. According to the findings, the present research could be created with the scope of potentially identifying ways to maintain their activity for agricultural, industrial and also scientific applications.
All-solid-state lithium-ion batteries (ASSLBs) are the next advancement in battery technology which is expected to power the next generation of electronics, particularly electric vehicles due to their high energy density and superior safety. ASSLBs require solid electrolytes with high ionic conductivity to serve as a Li-ion battery, driving extensive research efforts to enhance the ionic conductivity of the existing solid electrolytes. Keeping this in view, the B-site of Li0.33La0.56TiO3 (LLTO) solid electrolyte has been partially substituted with Ga and novel Ga-doped LLTO (Li0.33+xLa0.56Ti1−xGaxO3) solid-electrolytes are fabricated using the solid-state reaction method, followed by sintering at 1100 °C for 2 h. The effects of Ga substitution on the structural changes, chemical states, ionic conductivity, and electrochemical stability of LLTO are systematically analyzed. The XRD analysis of the LLTO samples confirms the formation of a tetragonal perovskite structure and increasing bottleneck size up to 3% Ga-doped samples. XPS results have further confirmed the successful substitution of Ti⁴⁺ by Ga³⁺. The Ga³⁺ substitution has successfully enhanced the conductivity of LLTO solid electrolytes and the highest conductivity of 4.15 × 10⁻³ S cm⁻¹ is found in Li0.36La0.56Ti0.97Ga0.03O3 (x = 0.03), which is an order of magnitude higher than that of pristine LLTO. This increase in ionic conductivity is a synergistic effect of B–O bond stretching resulting from the size difference between Ga³⁺ and Ti⁴⁺ and the increase in grain size. Moreover, the synthesized solid electrolytes are stable within the range of 2.28 to 3.78 V against Li/Li⁺, making them potential candidates for all-solid-state lithium-ion batteries.
Perovskite materials have garnered significant attention within a very short period of time by achieving competitive efficiency. In addition, this material demonstrated intriguing optoelectronic properties and versatile applications. Although they have confirmed amazing efficiency in solar cells at the laboratory scale, mass commercial manufacturing of perovskite solar cells (PSCs) is still a problem due to their poor longevity. Researchers have identified several intrinsic and extrinsic factors contributing to the instability of perovskite compounds and PSCs, and various approaches are being used to increase material quality and stability in order to extend the lifespan of PSCs. Despite these challenges, the potential of perovskite materials in revolutionizing solar energy remains a central point of scientific investigation and development. In this review, a comprehensive analysis is provided to discern the intrinsic and extrinsic factors contributing to the degradation of PSCs which certainly helps us to understand the underlying degradation mechanisms. In addition, we discussed some novel approaches that have already been adopted to augment the stability of the devices.
Vascular endothelial growth factor receptor-2 (VEGFR2) plays a pivotal role in promoting angiogenesis and contributing to the growth and progression of renal cancer. Hence, the current investigation was undertaken with the aim of identifying safe and potent phytochemicals from Aeginetia indica whole plant extract (AiWE) that can efficiently suppress the overexpression of VEGFR2. HPLC analysis identified and quantified 11 polyphenols in considerable amounts in AiWE. All the compounds showed good binding energies with VEGFR2 in the molecular docking study, except catechin hydrate and rutin hydrate. However, among the polyphenols, myricetin exhibited an almost similar hydrogen bonding pattern with the active site of VEGFR2. The all-atom molecular dynamic simulation revealed that myricetin showed a very stable interaction with the active site of VEGFR2 throughout the simulation. Based on these results, it is suggested that myricetin may inhibit angiogenesis by suppressing the VEGFR2 signaling, thereby impeding the growth and progression of renal cancer.
Introduction: Ethnomedicinal plants in Asia offer a promising, low‐side‐effect alternative to synthetic drugs for treating fungal infections, one of the most widespread communicable diseases caused by pathogenic fungi. Despite being underexplored, the region's rich plant diversity holds the potential for developing effective antifungal drugs. Research is increasingly focused on bioactive compounds from these plants, which show strong antifungal properties and may serve as leads for new drug development. Method: This comprehensive review included 257 articles from 658 published ones, selecting only peer‐reviewed, English‐language studies that met the inclusion criteria. In this review, we have discussed 27 Asian medicinal plants that contain 67 responsible phytochemicals deciphering promising antifungal action. Result: This finding revealed that Asian plant diversity can be helpful in treating fungal invasion against several fungal species. Inhibition and reduction of mycelial growth and zoospore germination, fungistatic and fungicidal activities, and inhibition of ergosterol biosynthesis are some common mechanisms reported in this review. Conclusion: Thus, this Asian plant diversity can provide a ray of hope as a modern therapeutic approach to bypass antimicrobial resistance issues noticed in recent days. Further research is still recommended to ascertain their exact mode of action, required dose, and safety and efficacy profile.
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