Publications by authors named "Mohammad A Hasnat"

Extracellular vesicles (EVs) play important roles in intercellular communication in various biological events. In particular, EVs released from cancer cells have attracted special attention. Although it has been reported that cancer-associated glycosphingolipids play important roles in the enhancement of malignant properties of cancer cells, the presence, behavior, and roles of glycosphingolipids in EVs have not been elucidated.

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Herein, natural-synthetic hybrid dual-state luminescent conducting polymers (DLCPs/DLCP1-DLCP8) possessing significant optoelectrochemical properties are strategically developed by the polymerization of prop-2-enamide, cis-butenedioic acid, 2-acrylamido-2-methylpropane-1-sulfonic acid, and in situ-generated 2-(3-acrylamidopropanamido)-2-methylpropane-1-sulfonic acid alongside the grafting of gum tragacanth. The spectroscopic data of aliphatic DLCPs affirm DLCP7 as the most stable supramolecular assembly endowing optoelectronic properties. Computational calculations identified -C(═O)NH-, -C(═O)OH, -OH, and -SOH as subluminophores.

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Neuroectoderm-derived tumors characteristically express gangliosides such as GD3 and GD2. Many studies have reported that gangliosides GD3/GD2 enhance malignant phenotypes of cancers. Recently, we reported that human gliomas expressing GD3/GD2 exhibited enhanced malignant phenotypes.

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Initially, four synthetic fluorescent polymers (SFPs) are synthesized from α-methacrylic acid and methanolacrylamide monomers carrying -C(=O)OH and -C(=O)NH subfluorophores, respectively. Among SFPs, ∼1:1 incorporation of subfluorophores in the optimum SFP3 is explored by spectroscopic analyses. Subsequently, chitosan is incorporated in SFP3 to produce five semi-synthetic fluorescent polymers (SSFPs).

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  • A polycrystalline platinum (Pt) electrode was used to convert nitrite ions into nitrogen compounds through electrochemical reduction in a neutral environment.
  • The reduction produced nitric oxide (NO) and ammonia (NH₃), suggesting a transformation of NO into NH₃ during the process, confirmed by various analytical techniques.
  • Kinetic studies indicated that the reduction of nitrite ions to NO is an irreversible reaction dependent on ion diffusion, with a formal reduction potential of -0.46 V and an activation energy of approximately 19.8 kJ/mol.
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  • This study focuses on the development of fluorescent conducting tautomeric polymers (FCTPs) using a combination of specific acids and amides, with FCTP3 showing the most promising properties through various spectroscopic techniques and computational analyses.
  • FCTP3 demonstrates unique subluminophores that enhance its redox characteristics, conductivity, and luminescence, with significant mechanisms like excited-state intramolecular proton transfer (ESIPT) contributing to its dual emission properties and aggregation-enhanced emissions (AEEs).
  • The polymer's ability to selectively detect heavy metals like Cr(III) and Cu(II) with low limits of detection, along with its proton conductivity evaluated through electrochemical
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  • The development of effective and affordable catalysts for hydrogen production is essential for promoting a sustainable hydrogen economy, with electrochemical water splitting being a key method.
  • A major focus of the review is on alternative, non-platinum (Pt-free) electrocatalysts, assessing their performance in the hydrogen evolution reaction (HER) while comparing them to Pt-based catalysts.
  • The review highlights the latest advancements in various materials, such as transition metal phosphides, carbides, sulphides, and nitrides, and discusses techniques to improve their efficiency, aiming to address challenges in scalable hydrogen production.
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The quest for sustainable and clean energy sources has intensified research on the Hydrogen Evolution Reaction (HER) in recent decades. In this study, we have presented a novel Ce-doped TiO catalyst synthesized through the sol-gel method, showcasing its potential as a superior electrocatalyst for HER in an acidic medium. Comprehensive characterization through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Energy dispersive X-ray (EDX), and Raman spectroscopy confirms the successful formation of the catalyst.

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World's highest arsenic (As) contamination is well-documented for the groundwater system of southwestern region (mainly Jashore district) of Bangladesh, where the majority of inhabitants are underprivileged. To mitigate As poisoning in southwestern Bangladesh, numerous steps have been taken so far by the government and non-governmental organizations (NGOs). Among them, digging deep tube wells and As removal by naturally deposited Fe(OH) species are being widely practiced in the contaminated areas.

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Organophosphorus Pesticides () are among the extensively used pesticides throughout the world to boost agricultural production. However, persistent residues of these toxic pesticides in various vegetables, fruits, and drinking water poses detrimental health effects. Consequently, the rapid monitoring of these harmful chemicals through simple and cost-effective methods has become crucial.

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  • - The study examined severe COVID-19 cases at two hospitals in Dhaka, Bangladesh, focusing on factors linked to fatal outcomes by comparing 35 patients who survived with 8 who died.
  • - Key findings showed that deceased patients experienced longer periods of shortness of breath, had more comorbid conditions, and lower SARS-CoV-2 RT-PCR cycle threshold values, with higher levels of liver enzymes and poor antibody responses.
  • - Recommendations include early antiviral treatment and the use of anticoagulants, as they may help reduce the risk of death in severe COVID-19 cases, particularly in older patients and those with multiple health issues.
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  • Exosomes are tiny vesicles that play a crucial role in communication between cells and are involved in various biological processes, particularly in inflammation, regeneration, and cancer.
  • The study focuses on cancer-associated gangliosides, specifically GD2, found in malignant melanomas, which enhance cancerous properties in surrounding cells.
  • EVs from GD2-expressing melanomas promote aggressive behaviors like growth and invasion in GD2-negative melanomas, indicating their significant impact on creating a more hostile tumor environment.
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A detailed kinetic investigation of As(III) oxidation was performed on gold surface within pH between ∼3.0 and ∼9.0.

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  • The study investigates the duration of immune responses, specifically antibody levels and memory B cells, following various severities of SARS-CoV-2 infections in patients from Bangladesh over a six-month period.
  • Findings reveal that patients with moderate to severe COVID-19 maintained higher levels of IgG antibodies for up to six months, while those with mild or asymptomatic cases saw a decline after three months.
  • Additionally, the research highlights that all symptomatic patients developed specific memory B cells and increased T helper cell responses, contrasting with asymptomatic individuals who showed negligible immune response changes.
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Chlorazol yellow (CY) is a commonly used anionic, toxic, mutagenic, and potentially carcinogenic azo dye, which is menacing to the environment, aquatic system, food chain, and human health as well. To remove CY dye molecules from an aqueous medium, a series of Ce, Bi, and N co-doped TiO photocatalysts were prepared by varying the composition of the dopants. Under sunlight irradiation, the resultant 5 wt% (Ce-Bi-N) co-doped TiO composite catalyst was found to show the best catalytic activity.

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Nitrate is a water-soluble toxic pollutant that needs to be excluded from the environment. For this purpose, several electrochemical studies have been conducted but most of them focused on the nitrate reduction reaction (NRR) in alkaline and acidic media while insignificant research is available in neutral media with Pt electrode. In this work, we explored the effect of three coinage metals (Cu, Ag, and Au) on Pt electrode for the electrochemical reduction of nitrate in neutral solution.

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Coronavirus disease 2019 (COVID-19) is a protean disease causing different degrees of clinical severity including fatality. In addition to humoral immunity, antigen-specific T cells may play a critical role in defining the protective immune response against SARS-CoV-2, the virus that causes this disease. As a part of a longitudinal cohort study in Bangladesh to investigate B and T cell-specific immune responses, we sought to evaluate the activation-induced marker (AIM) and the status of different immune cell subsets during a COVID-19 infection.

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Here, a sensitive voltametric electrochemical sensor probe was fabricated to reliably trace the detection of L-aspartic acid in phosphate-buffered medium using a glassy carbon electrode (GCE) layered with a film of wet-chemically prepared AgO-doped ZnO nanosheets (NSs). EDS, FESEM, XPS, and X-ray diffraction analyses were implemented as characterizing tools of prepared NSs to confirm the structural and compositional morphology, binding energies of existing atoms, and the crystallinity of synthesized NSs. The differential pulse voltammetry (DPV) was applied to the trace detection of L-aspartic acid, and exhibited a wide detection range of 15.

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During the electrocatalytic reduction of nitrate, nitrite is often evolved as a product along with ammonia due to the sluggish nitrite-to-ammonia conversion process compared to the nitrate-to-nitrite conversion step. Rhodium metal has been proven to enhance nitrite-to-ammonia conversion rates, yielding ammonia as the only final product. In the present article, we have shown how effectively Rh nanoparticles immobilized on Pt and Pd films deposited on H conducting Nafion-117 membranes eliminate intermediate nitrite ions during the progress of the nitrate reduction reaction in a flow type reactor.

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The increasing demands of energy and environmental concerns have motivated researchers to cultivate renewable energy resources for replacing conventional fossil fuels. The modern energy conversion and storage devices required high efficient and stable electrocatalysts to fulfil the market demands. In previous years, we are witness for considerable developments of scientific attention in Metal-organic Frameworks (MOFs) and their derived nanomaterials in electrocatalysis.

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  • * The electrochemical behavior of hydrogen peroxide on the GCE/Nafion/Ni setup was analyzed using techniques like linear sweep voltammetry and chronoamperometry, revealing that an electron transfer step governs the reaction rate very effectively.
  • * The sensor demonstrated a linear detection limit of 1.8 μM and a dynamic detection range of 5-500 μM, showcasing its reliability by successfully analyzing real industrial samples with reproducible results.
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Background: COVID-19 caused by SARS-CoV-2 ranges from asymptomatic to severe disease and can cause fatal and devastating outcome in many cases. In this study, we have compared the clinical, biochemical and immunological parameters across the different disease spectrum of COVID-19 in Bangladeshi patients.

Methodology/principal Findings: This longitudinal study was conducted in two COVID-19 hospitals and also around the community in Dhaka city in Bangladesh between November 2020 to March 2021.

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Ivermectin, a US Food and Drug Administration-approved anti-parasitic agent, was found to inhibit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication in vitro. A randomized, double-blind, placebo-controlled trial was conducted to determine the rapidity of viral clearance and safety of ivermectin among adult SARS-CoV-2 patients. The trial included 72 hospitalized patients in Dhaka, Bangladesh, who were assigned to one of three groups: oral ivermectin alone (12 mg once daily for 5 days), oral ivermectin in combination with doxycycline (12 mg ivermectin single dose and 200 mg doxycycline on day 1, followed by 100 mg every 12 h for the next 4 days), and a placebo control group.

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The electrochemical behaviors of thiourea (TU) oxidation have been studied at Palladium (Pd) electrode in the acidic medium by recording cyclic voltammograms (CVs). The influence of pH was investigated in the pH range of 1.0 to 9.

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FeS /carbon nanotube (CNT) nanocomposites were synthesized and immobilized on the surface of a glassy carbon electrode (GCE) in order to investigate the electrocatalytic conversion of 4-aminophenol (4-AP) into p-quinone in an aqueous medium. The reformed electronic properties (in terms of lowering of band-gap energy and charge-transfer resistance), as well as improved surface area, result in an enhanced redox reaction of 4-AP in the presence of FeS -CNT NCs compared to that with FeS alone. The 4-AP molecules undergo coupled two-proton and two-electron transfer quasi-reversible redox reactions with a symmetry factor of 0.

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