Publications by authors named "Rafique Islam"

A wet chemical route is reported for synthesising organic molecule stabilized lead sulfide nanoparticles. The dielectric capacitance, energy storage performances and field-driven polarization of the organic-inorganic hybrid system are investigated in the form of a device under varying temperature and frequency conditions. The structural analysis confirmed the formation of the monoclinic phase of lead sulfide within the organic network.

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In this study, (hemi)cellulosic biochar-based environment-friendly non-toxic nanocomposite (nAg-AC) was fabricated for an inordinate overlook of toxic dye-laden wastewater depollution. This hybrid nanocomposite grafted with silver nanoparticles, numerous hydroxyl and π-bond containing functional groups exhibited outstanding physicochemical properties. FESEM images indicated the heterogeneous porous structure of nAg-AC, while BET analysis revealed mesoporous property with a significant increment of overall surface area (132%).

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Background: In the United States, African Americans (AAs) have greater risk for Class III obesity and cardiovascular disease (CVD). Previous reports suggest that AAs have a different immune cell profile when compared to Caucasians.

Methods: The immune cell profile of AAs was characterized by flow cytometry using two experimental setups: ex vivo (N = 40) and in vitro (N = 10).

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Dual functional innovative approaches were developed to tackle the algal scum problem in water by utilizing the algal (Spirogyra sp.) biomass waste for organic dye-laden industrial wastewater treatment, a global problem, and challenge. Therefore, an algal biochar-based nanocomposite (nAgBC) was synthesized and employed as a low-cost adsorbent for Congo red (CR) removal.

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Unlabelled: Silver nanoparticle (AgNP) has been one of the most commonly used nanoparticles since the past decade for a wide range of applications, including environmental, agricultural, and medical fields, due to their unique physicochemical properties and ease of synthesis. Though chemical and physical methods of fabricating AgNPs have been quite popular, they posed various environmental problems. As a result, the bioinspired route of AgNP synthesis emerged as the preferred pathway for synthesis.

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The present study utilized discarded tea leaf waste to produce 'Tea leaf biochar' (TLB) as the functional matrix for the fabrication of hybrid nanocomposite (nAg-TC), with colloidal deposition of silver nanoparticles (nAg) via modified chemical co-precipitation, for treatment of dye-laden wastewater. The chemical composition, physicochemical properties, and morphology of nAg-TC, and active surface functional groups involved in adsorption were identified using BET, FESEM-EDX, FTIR, TGA, XPS, and XRD. The nAg-TC matrix was found to be heterogeneous, mesoporous, thermostable, with rich in active surface functional groups (-OH, =NH, =CH, CC, CO, CN, and CC), and nAg as a dopant material.

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Introduction: Although physical activity (PA) reduces cardiovascular disease (CVD) risk, physical inactivity remains a pressing public health concern, especially among African American (AA) women in the USA. PA interventions focused on AA women living in resource-limited communities with scarce PA infrastructure are needed. Mobile health (mHealth) technology can increase access to PA interventions.

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Apolipoprotein A-I (ApoA-I) mimetic peptides are potential therapeutic agents for promoting the efflux of excess cellular cholesterol, which is dependent upon the presence of an amphipathic helix. Since α-methylated Ala enhances peptide helicity, we hypothesized that incorporating other types of α-methylated amino acids into ApoA-I mimetic peptides may also increase their helicity and cholesterol efflux potential. The last helix of apoA-I, peptide 'A' (VLESFKVSFLSALEEYTKKLNT), was used to design peptides containing a single type of α-methylated amino acid substitution (Ala/A, Glu/D, Lys/K, Leu/L), as well as a peptide containing both α-methylated Lys and Leu (6).

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The widespread emergence of pyrethroid-resistant has intensified the need to find new contact mosquitocides for indoor residual spraying and insecticide treated nets. With the goal of developing new species-selective and resistance-breaking acetylcholinesterase (AChE)-inhibiting mosquitocides, in this report we revisit the effects of carbamate substitution on aryl carbamates, and variation of the 1-alkyl group on pyrazol-4-yl methylcarbamates. Compared to aryl methylcarbamates, aryl dimethylcarbamates were found to have lower selectivity for AChE (AChE) over human AChE (hAChE), but improved tarsal contact toxicity to G3 strain .

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Peptides mimicking the major protein of highdensity lipoprotein (HDL), apolipoprotein A-I (apoA-I), are promising therapeutics for cardiovascular diseases. Similar to apoA-I, their atheroprotective property is attributed to their ability to form discoidal HDL-like particles by extracting cellular cholesterol and phospholipids from lipid microdomains created by the ABCA1 transporter in a process called cholesterol efflux. The structural features of peptides that enable cholesterol efflux are not well understood.

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New public health insecticides are urgently required to prevent the spread of vector-borne disease. With the goal of identifying new K-channel-directed mosquitocides, analogs of the RH-5849 family of diacyl t-butylhydrazines were synthesized and tested for topical toxicity against adult Anopheles gambiae, the African vector of malaria. In total, 80N'-monoacyl and N, N'-diacyl derivatives of benzyl- and arylhydrazines were prepared.

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Mosquito-borne illnesses are of great concern throughout the world, and chemical insecticides are commonly employed to decrease mosquito populations. However, the developmental insecticide pipeline for vector control has primarily been filled by repurposed agricultural products, and is hampered by their widespread use and insecticide resistance. The present study was performed in the search for new chemical insecticides or insecticide synergists.

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Apolipoprotein B (apoB) is a large amphipathic protein that is the structural scaffold for the formation of several classes of lipoproteins involved in lipid transport throughout the body. The goal of the present study was to identify specific domains in the apoB sequence that contribute to its lipid binding properties. A sequence analysis algorithm was developed to identify stretches of hydrophobic amino acids devoid of charged amino acids, which are referred to as hydrophobic cluster domains (HCDs).

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Due to the light excitation, the valence band electron of the copper (I) sulfide quantum dot transfer to the conduction band and act as a scavenger of the terminal proton of the alkyne in the presence of organic azide with the formation of 1,4-disubstituted 1,2,3-triazoles, where the copper(I) species of Cu2S act as a catalyst for the reaction. The above cycloaddition reaction between alkyne and azide is commonly known as the Click reaction. In this study, experiments were carried out under the exposure of ultra-violate and daylight and also dark environment.

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Potential targets for new vector control insecticides are nerve and muscle potassium channels. In this study, the activities of known potassium channel blockers (4-aminopyridine, quinidine, and tetraethylammonium) and the insecticide propoxur were compared to three experimental catechols and several other compounds against Anopheles gambiae and Aedes aegypti mosquitoes. Experimental catechol 1 was the most toxic experimental compound in all of the mortality assays conducted, but was at least 100-fold and 39-fold less toxic than propoxur against Ae.

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There is a growing interest in studies of mosquito physiology and toxicology due to the heightened need for controlling this group of human disease vectors. In the process of testing a group of polar compounds on mosquito muscles, a novel headless larva bioassay was developed. The heads were removed from fourth instar Aedes aegypti larvae, which permitted access of pharmacological agents to the hemocoel while maintaining larval viability.

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Malaria is a devastating disease in sub-Saharan Africa, and current vector control measures are threatened by emerging resistance mechanisms. With the goal of developing new, selective, resistance-breaking insecticides we explored α-fluorinated methyl ketones as reversible covalent inhibitors of Anopheles gambiae acetylcholinesterase (AgAChE). Trifluoromethyl ketones 5 demonstrated remarkable volatility in microtiter plate assays, but 5c,e-h exhibited potent (1-100 nM) inhibition of wild type (WT) AgAChE and weak inhibition of resistant mutant G119S mutant AgAChE.

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During the polymerization of aniline using copper sulphate, act as an oxidizing agent, the in-situ synthesized Cu(I) ion catalyzed the cyclo-addition between azides and alkynes. This work represents the merging of two steps, synthesis of the catalyst and application of the catalyst, in a one pot reaction. The elimination of the separate catalyst synthesis step is economic in terms of cost and time.

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To identify potential selective and resistance-breaking mosquitocides against the African malaria vector Anopheles gambiae, we investigated the acetylcholinesterase (AChE) inhibitory and mosquitocidal properties of isoxazol-3-yl dimethylcarbamates (15), and the corresponding 3-oxoisoxazole-2(3H)-dimethylcarboxamide isomers (14). In both series, compounds were found with excellent contact toxicity to wild-type susceptible (G3) strain and multiply resistant (Akron) strain mosquitoes that carry the G119S resistance mutation of AChE. Compounds possessing good to excellent toxicity to Akron strain mosquitoes inhibit the G119S mutant of An.

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Mono-antennary galacto derivatives of cholesterol are being actively developed to direct lipoplexes to the asialoglycoprotein receptor (ASGP-R) on hepatocytes. Here we report on a novel ASGP-R ligand cholest-5-en-3-yl [1-(β-D-galactopyranosyl)-1H-1,2,3-triazol-4-yl]methylcarbamate (4), assembled by a copper(I)-catalyzed azide-alkyne cycloaddition (click chemistry), and compare it with cholest-5-en-3-yl-β-D-galactopyranoside (2) and cholest-5-en-3-yl [1-(β-D-galactopyranosyl-1'-oxy)phen-4-yl]carbamate (3), in liposome formulations with or without 5 mol% distearoylphosphatidylethanolamine poly(ethylene glycol)2000, intended for DNA delivery to ASGP-R-positive hepatocyte-derived HepG2 cells and the ASGP-R-negative embryo kidney cell line HEK293. Transfection levels attained with lipoplex 4 were 100 and 300% greater than those for lipoplexes 2 and 3 respectively in HepG2 cells, while competition assays reduced transfection levels by up to 98%.

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Conventional insecticides targeting acetylcholinesterase (AChE) typically show high mammalian toxicities and because there is resistance to these compounds in many insect species, alternatives to established AChE inhibitors used for pest control are needed. Here we used a fluorescence method to monitor interactions between various AChE inhibitors and the AChE peripheral anionic site, which is a novel target for new insecticides acting on this enzyme. The assay uses thioflavin-T as a probe, which binds to the peripheral anionic site of AChE and yields an increase in fluorescent signal.

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While sialylation plays important functions in the nervous system, the complexity of glycosylation pathways and limitations of genetic approaches preclude the efficient analysis of these functions in mammalian organisms. Drosophila has recently emerged as a promising model for studying neural sialylation. Drosophila sialyltransferase, DSiaT, was shown to be involved in the regulation of neural transmission.

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Acetylcholinesterase (AChE) is a proven target for control of the malaria mosquito (Anopheles gambiae). Unfortunately, a single amino acid mutation (G119S) in An. gambiae AChE-1 (AgAChE) confers resistance to the AChE inhibitors currently approved by the World Health Organization for indoor residual spraying.

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To identify potential human-safe insecticides against the malaria mosquito we undertook an investigation of the structure-activity relationship of aryl methylcarbamates inhibitors of acetylcholinesterase (AChE). Compounds bearing a β-branched 2-alkoxy or 2-thioalkyl group were found to possess good selectivity for inhibition of Anopheles gambiae AChE over human AChE; up to 530-fold selectivity was achieved with carbamate 11d. A 3D QSAR model is presented that is reasonably consistent with log inhibition selectivity of 34 carbamates.

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Synopsis of recent research by authors named "Rafique Islam"

  • - Rafique Islam's recent research focuses on the synthesis and application of hybrid nanocomposites for environmental remediation and energy storage, including the use of biochar and silver nanoparticles for toxic dye removal from wastewater.
  • - His work includes investigating the dielectric and energy storage properties of organic molecule functionalized lead sulfide nanoparticles, demonstrating promising performances for energy applications.
  • - Additionally, Islam's studies highlight differences in immune cell profiles related to cardiovascular health in African American populations, suggesting a connection with obesity and inflammation, thereby addressing public health concerns.