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    Different metal-doped ZnS quantum dots photocatalysts for enhancing the permeability and antifouling performances of polysulfone membranes with and without UV irradiation
    (Pergamon-Elsevier Science Ltd, 2022) Vatanpour, Vahid; Karatas, Okan; Amiri, Saba; Rajabi, Hamid Reza; Koyuncu, Ismail; Khataee, Alireza
    In this study, the effect of three different transition metal ion dopants (Mn2+, Fe2+, and Co2+) on the characteristics of zinc sulfide (ZnS) quantum dots (QDs) was investigated and the obtained QDs photocatalysts were applied for the modification of polysulfone (PSf) mixed matrix membranes to reduce membrane fouling. The synthesized QDs and fabricated membranes were fully identified with SEM, TEM, AFM, FTIR analyses, and also underwent porosity and contact angle tests. Flux recovery ratios (FRR) significantly increased from 69.8% (bare) to 85.0% (1% Fe-doped ZnS QDs) after modification of membranes with metal-doped QDs. The contact angles of the prepared membranes decreased with doping of dissimilar metals, therefore hydrophilicity increased, and reversible/non-reversible blockages were improved. Besides, the use of UV irradiation during the washing of the membranes increased the FRR of the photocatalytic activated membranes to 91.2%. Compared to the bare PSf membrane in dye solution filtration, 1% Fe-doped ZnS QDs membrane yielded twice as much flux and 15% higher FRR results. Therefore, the results proved that metal-doped QDs can be used in the modification of PSf membranes with high efficiency.
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    Total Phenolic, Flavonoid, Fatty Acid Contents and Cytotoxic, Antioxidant, and Antimicrobial Activities of Hedysarum aucheri
    (Sciencedomain Int, 2017) Uyar, Zafer; Koz, Ömer; Uyar, Ebru; Arslan, Ulku; Koyuncu, Ismail; Nalbantsoy, Ayse
    In vitro cytotoxic, antioxidant, and antimicrobial activities along with total phenolic and flavonoid contents of methanol, hexane, dichloromethane, butanol, and aqueous extracts and chemical composition and fatty acids of n-hexane extract from endemic Hedysarum aucheri were determined. The fatty acid content of the n-hexane extract was determined by GC-MS analysis. Twenty-four out of 39 compounds identified as fatty acid methyl esters constitute 84.20% of hexane extract content. Five of 6 major components were fatty acids, namely alpha-linolenic acid (ALA) (32.37%), palmitic acid (24.69%), linoleic acid (LA) (9.16%), stearic acid (7.11%), Arachidic acid (3.14%), and the other one was an acyclic diterpene alcohol called phytol (12.01%). Butanol extract was found to be the richest in flavonoid (66.3 +/- 1.3 mg QU/g DW) and phenolic (122.4 +/- 1.6 mg GAE/g DW) compounds. Antioxidant activities of the extracts were evaluated by Cupric-ionreducing antioxidant capacity (CUPRAC), and ABTS radical scavenging capacity. Butanol extract showed the highest antioxidant activity indicating a strong correlation between flavonoid/phenolic content and antioxidant activity. Also, cytotoxic activities of the extracts were evaluated against a panel of cancer cells (PC3, HeLa, CaCo-2, U-87MG, A549, and MCF-7) and normal cell line HEK293. Dichloromethane extract (DCM) exhibited exceptionally high tumor selective cytotoxicity towards cancer cells with IC50 values varying between 0.64 and 24 mu g/mL while not impairing the normal cells. DCM extract was found to possess higher cytotoxic activity towards the tested cancer cells than some anticancer drugs reported in the literature. Also, antimicrobial activities of the extracts were determined by agar disc diffusion and the micro-dilution methods against a series of microorganisms and hexane extract showed the highest antimicrobial activity. We hereby report both the pharmaceutical potential of H. aucheri concerning its various biological activities and the phytochemical composition regarding its total flavonoid, phenolic, and fatty acid content.