20 research outputs found

    Sorption of toxic metal ions in aqueous environment using electrospun polystyrene fibres incorporating diazole ligands

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    Electrospun polystyrene fibres incorporating potassium salts of pyrazole-1-carbodithioate and imidazole-1-carbodithioate were employed as sorbents for heavy metals from aqueous environments. The equilibrating time, initial metal concentrations and sorbent mass for optimal adsorption were 40 min, 5 mg/ℓ and 8 mg, respectively. The optimal pH for metal ion uptake was between 6.3 and 9.0 and was found to be dependent on the basicity of the ligands. Protonation constants for the ligands in aqueous solutions were determined potentiometrically; pK of the imidazole was 6.82 while that of the pyrazole was 3.36. The efficiencies of adsorption and desorption of metals on the imidazolyl-incorporated sorbents were more than 95%, up to the fifth cycle of usage. The limits of quantification were ≤ 0.0145 mg/ℓ for all the metals. Accuracy of the determinations, expressed as relative error between the certified and observed values of certified reference groundwater samples was ≤ 0.2% with relative standard deviations < 3%. Electrospun polystyrene fibres incorporating imidazoles proved to be efficient sorbents for divalent heavy metal ions in aqueous environments as their efficiencies exceeded those of chitosan microspheres, ion-imprinted composites, amino-functionalised mesoporous materials and most of the biomass-based sorbents previously reported on.Keywords: electrospinning, polystyrene, heavy metals, diazol

    Tackling antimicrobial resistance in primary care facilities across Pakistan : current challenges and implications for the future

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    Antibiotics are gradually becoming less effective against bacteria worldwide, and this issue is of particular concern in economically-developing nations like Pakistan. We undertook a scoping review in order to review the literature on antimicrobial use, prescribing, dispensing and the challenges associated with antimicrobial resistance in primary care (PC) settings in Pakistan. Furthermore, this review aims to identify potential solutions to promote appropriate use of antimicrobials in Pakistan. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) checklist, a comprehensive scoping review was conducted to review the literature of antimicrobials used, prescribed and dispensed in PC settings in Pakistan. Google Scholar and Pub-Med were searched for the period 2000–2023. Papers were analyzed on the basis of eligibility i.e., included antimicrobial use, prescribing and dispensing practices by general population at homes, by prescribers in outpatient departments of hospitals and by pharmacists/dispensers in community pharmacies, respectively. Two researchers analyzed the articles thoroughly and disagreements were resolved through discussion with a third reviewer. Both quantitative and qualitative research studies were eligible for inclusion. Additionally, the selected papers were grouped into different themes. We identified 4070 papers out of which 46 studies satisfied our eligibility criteria. The findings revealed limited understanding of antimicrobial resistance (AMR) by physicians and community pharmacists along with inappropriate practices in prescribing and dispensing antibiotics. Moreover, a notable prevalence of self-medication with antibiotics was observed among the general population, underscoring a lack of awareness and knowledge concerning proper antibiotic usage. Given the clinical and public health implications of AMR, Pakistan must prioritize its policies in PC settings. Healthcare professionals (HCPs) need to reduce inappropriate antibiotic prescribing and dispensing, improve their understanding of the AWaRe (access, watch and reserve antibiotics) classification and guidance, monitor current usage and resistance trends, as well as implement antimicrobial stewardship (ASP) activities starting in targeted locations

    Quality control of Harpagophytum procumbens products using High Pressure Liquid Chromatography-Diode Array Detection (HPLC-DAD)

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    Iridoid and phenylethanoid glycosides were used as compounds to monitor the quality of Devil’s Claw (Harpagophytum procumbens) based products in this investigation. A HPLC-DAD method was developed for the determination of the phenylethanoid glycoside isoacteoside and the iridoid glycoside harpagoside in commercially available Devil’s Claw products. The limits of detection (LOD) obtained were 1.08 μg/ml for harpagoside and 1.70 μg/ml forisoacteoside. Limits of quantification (LOQ) of harpagoside and isoacteoside were 3.59 μg/ml and 5.65 μg/ml respectively. The harpagoside and isoacteoside contents in the ethanol extracts of the commercial products were found to be in the range of 2.2 % - 3.9 % and 0.22 % - 0.50 % respectively. Keywords: Harpagophytum procumbens, phenylethanoid glycosides, iridoid glycosides, harpagoside, HPLC-DAD profile

    Evaluation of the effect of various drying techniques on the composition of the psychoactive phenylpropylamino alkaloids of khat (<i>Catha edulis</i> Forsk) chewing leaves

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    The study demonstrated that by freezing or drying under different conditions, cathinone could be detected in the khat (<i>Catha edulis</i> Forsk) samples that have been harvested for more than four months. Freeze drying or freezing in the refrigerator (-20 <sup>o</sup>C) yielded more than 73% of cathinone. Air drying, sun drying or oven drying at 60 <sup>o</sup>C resulted in a cathinone composition of 57%, 42% and 36%, respectively. The study confirmed that, freshly harvested tender leaves of khat contained exclusively of cathinone but upon sun drying, part of it decomposes to cathine and norephedrine leaving cathinone as a major component. Thus it is wrong to assume that sun drying the leaves can result complete conversion of cathinone to cathine and norephedrine. Furthermore, the results of the study confirmed that it was possible to preserve khat samples for longer periods after freeze drying or deep freezing without significant loss of cathinone.DOI: http://dx.doi.org/10.4314/bcse.v27i3.

    A thirst for advancement

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