695 research outputs found

    Role of Fungal Biomass in N-Hexane Biofiltration

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    The biofiltration of n-hexane is studied to optimize determinants factors of hydrophobic VOC filtration efficiency. Four trickle-bed air biofilters (TBABs) were employed; two of which were supplied with nutrients buffered at a neutral pH, while another two at an acidic pH of 4 to induce and enhance fungal growth. The loading rate of n-hexane was kept constant in all TBABs at 13 g/m3/h. At each pH levels studied, the biomass of the TBABs was pre-acclimated using different ratios of n-hexane and methanol. The fungal biomass responsible for the degradation of n-hexane was then examined and quantified. Dichloran Rose Bengal Chloramphenicol agar was used for fungi quantification, and optical microscopy for classification. Effluent biomass was validated by measuring volatile suspended solids. Fungal counts resulting from n-hexane biodegradation were related to nitrate and carbon consumption. It was found that n-hexane elimination capacity closely followed biomass growth, and reached a steady-state at an optimum biomass density of roughly 3000 cfu/ml. Major shifts in fungal species were observed in all TBABs. Dominant fungal species grew slowly to become the most numerous, and were found to provide maximum elimination capacity, although TBABs pre-acclimated to higher methanol concentrations took less time to reach this steady-state. It was concluded, therefore, that steady and monitored growth of TBAB biomass is an essential factor in maximizing fungi’s ability to metabolize VOCs and that a new ecological biofiltration model may be the most effective at VOC purification

    Chemistry of Substituted Thiazinanes and Their Derivatives

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    Thiazinanes and its isomeric forms represent one of the most important heterocyclic compounds, and their derivatives represented a highly potent drug in disease treatment such as, 1,1-dioxido-1,2-thiazinan-1,6-naphthyridine, which has been shown to have anti-HIV activity by a mechanism that should work as anti-AIDS treatment, while (Z)-methyl 3-(naphthalen-1-ylimino)- 2-thia-4-azaspiro[5 5]undecane-4-carbodithioate showed analgesic activity, cephradine was used as antibiotic and chlormezanone was utilized as anticoagulants. All publications were interested in the chemistry of thiazine (partially or fully unsaturated heterocyclic six-membered ring containing nitrogen and sulfur), but no one was dealing with thiazinane itself which encouraged us to shed new light on these interesting heterocycles. This review was focused on the synthetic approaches of thiazinane derivatives and their chemical reactivity

    Evaluation of some phenolic extracts against aphids (Aphis craccivora) Koch under laboratory conditions

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    Local farmers worldwide have complained in recent years that insect pests have become resistant to the majority of insecticides, owing to pesticide abuse. In addition, highly poisonous and harmful substances may cause health and environmental dangers. Friendly alternatives such as plant extracts are the main targets as substituents to synthetic pesticides. The present study aimed to extract total phenols from some plants and evaluate their efficacy on aphids, Aphis craccivora, under laboratory conditions. Four methanolic plant extracts from Punica granatum, Lantana camara, Portulaca oleracea and Ziziphus jujuba, containing phenolic components were evaluated against A. craccivora through: slide dipping, spraying, and leaf dipping techniques. Generally, positive relationships between the concentrations of the tested phenolic extracts and their mortality percentages were noticed in the case of slide dipping and spraying techniques. Conversely, no biological efficacy was found using the leaf dipping technique. The descending order of effectiveness of the tested extracts depending on their EC50 values was 0.017, 0.321, 1.142 and 16.114 ppm for Z. jujuba, P. oleraceae P. granatum and L. comara, respectively, in the case of the slide dipping technique. In contrast, P. granatum, L. camara, P. oleraceae and Z. jujuba had EC50 values of 0.0023, 0.017, 0.321 and 2.3409 ppm, respectively, in the case of the spraying technique. Additionally, a direct proportion was found between mortality percentages and treatment period for plant extracts under study with both techniques. After formulation and completion of additional essential field research, phenols isolated from the plants under study could be employed to combat A. craccivora

    Chemistry and Biological Activities of 1,2,4-Triazolethiones—Antiviral and Anti-Infective Drugs

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    Mercapto-substituted 1,2,4-triazoles are very interesting compounds as they play an important role in chemopreventive and chemotherapeutic effects on cancer. In recent decades, literature has been enriched with sulfur- and nitrogen-containing heterocycles which are used as a basic nucleus of different heterocyclic compounds with various biological applications in medicine and also occupy a huge part of natural products. Therefore, we shed, herein, more light on the synthesis of this interesting class and its application as a biologically active moiety. They might also be suitable as antiviral and anti-infective drugs

    Carbon tetrachloride-induced liver disease in rats: the potential effect of supplement oils with vitamins E and C on the nutritional status

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    The aim of the present investigation was to study the effects of olive oil (OO), corn oil (CO), and flaxseed oil (FO), with or without supplementation of vitamins E and C, on food intake, body weight gain %, liver weight to body weight %, total lipids, liver functions, and liver histology in male rats intoxicated with carbon tetrachloride (CCl4)

    Carbon tetrachloride-induced liver disease in rats: the potential effect of supplement oils with vitamins E and C on the nutritional status

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    The aim of the present investigation was to study the effects of olive oil (OO), corn oil (CO), and flaxseed oil (FO), with or without supplementation of vitamins E and C, on food intake, body weight gain %, liver weight to body weight %, total lipids, liver functions, and liver histology in male rats intoxicated with carbon tetrachloride (CCl4)

    Synthesis of Ni-Fe-CO3_3 layered double hydroxide as Effective Adsorbent to remove Cr(VI) and ARS-dye from aqueous media

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    Ni2^2/Fe3+^{3+}LDH, (Ni-Fe-CO3 LDH) with Ni/Fe molar ratio 3.0 was synthesized by co-precipitation for the remediation of chromium (VI), and Alizarine Red-S (ARS-dye) as anionic species. The investigated adsorbent was characterized by TGA, SEM, XRD, BET and FTIR. The effect of the hydrogen ion concentration of the medium, shaking time, ARS-dye and/or Cr(VI) concentration and adsorbents mass on the process was studied. The results of Ni-Fe-CO3_3 LDH fitted well with the pseudo-second-order model. Langmuir isotherm is more favor than the Freundlich isotherm with maximum capacity (QmaxQ_{max}) of 69.9 and 6.1 mg/g for ARS-dye and Cr(VI), respectively

    Synthesis and crystallographic evaluation of diazenyl- and hydrazothiazoles. [5.5] sigmatropic rearrangement and formation of thiazolium bromide dihydrate derivatives

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    In this investigation the synthesis of diazenylthiazoles (3a-e) by the reaction of arylthiosemicarbazides with omega-bromoacetophenones via Eschenmoser-coupling reaction in acetonitrile and equimolar amounts of triethylamine and triphenylphosphine. Upon heating 1,4-disubstituted thiosemicarbazides with omega-bromoacetophenones in absolute ethanol, hydrazothiazoles (16a-i) were precipitated. On the other hand, the reaction of arylthiosemicarbazides with omega-bromoacetophenones in refluxing ethanol yielded 2-amino-5-[4-aminophenyl]-4-phenylthiazolium bromide dihydrate derivatives (19a-g) via [5.5] sigmatropic shift. The studied products were further characterized by IR, H-1 NMR, C-13 NMR and mass spectrometry. X-ray single crystal of 3a and 16h showed that, the molecules crystallized in the triclinic crystal system, space group P2(1)/c. Whereas the X-ray single crystal of 19b showed the molecule crystalized in orthorhombic, space group P2(1)2(1)2(1). In the crystal of 19b, the lattice water and bromide ion associated through hydrogen bonded with thiazole-NH2. (C) 2018 Published by Elsevier B.V.Peer reviewe

    Eschenmoser-Coupling Reaction Furnishes Diazenyl-1,2,4-triazole-5(4H)-thione Derivatives

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    Diazenyl 1,2,4-triazol-5(4H)-thione derivatives were synthesized in good yields via Eschenmoser-coupling reaction and nucleophilic attack between 1,4-disubstituted thiosemicarbazides and 2,3,5,6-tetrachloro-1,4-benzoquinone (p-CHL). The structure of the synthesized compounds was confirmed by IR, NMR and mass spectral data as well as single crystal X-ray analysis.Peer reviewe

    Regioselective and stereoselective synthesis of epithiomethanoiminoindeno[1,2-b]furan-3-carbonitrile : heterocyclic [3.3.3]propellanes

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    Synthesis of heteropropellanes in one step: the reaction between dicyanomethylene-1,3-indanedione (CNIND) and N-substituted-2-(2,4-dinitrophenyl)hydrazinecarbothioamides, furnished (3aR,8bS,Z)-2-amino-9-substituted-10-(2-(2,4-dinitrophenyl)hydrazono)-4-oxo-4H-3a,8b-(epithiomethanoimino)indeno[1,2-b]furan-3-carbonitrile as a type of (2,4-dinitrophenyl)hydrazono[3.3.3]propellanes in good yields as single diastereomers. Structure determination and confirmation of the synthesized products have been achieved using various and modern spectroscopic techniques such as IR, NMR (H-1 NMR and(13)C NMR), mass spectrometry, as well as X-ray crystal analysis. The X-ray structure data cleared that the molecule of7awas crystalized as monoclinic, space group C2/c (no.15). [GRAPHICS] .Peer reviewe
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