Deep Extractive Oxidative Desulfurization of Model Oil/Crude Oil using Different Keggin Heteropoly Acids Supported on K10 Montmorillonite

This study investigated the catalytic performance of three polyoxometalates (H3PMo12O40 (PMo), H3PW12O40 (PW), and H4SiW12O40 (SiW)) supported on montmorillonite K10 for oxidative desulfurization (ODS) of thiophenic model oil, crude oil, and gasoline. Experimental results revealed that PW exhibited higher activity than PMo and SiW. The best solvent for mixed model oil was found to be EtOH, while MeCN was optimal for crude oil to remove oxidized sulfur compounds in a biphasic system under atmospheric pressure at 75°C in the presence of H2O2 as an oxidating agent. Using PW/K10 as the catalyst, the conversion of mixed model/EtOH and crude oil/MeCN reached 98.76% and 51.36%, respectively, under optimal conditions for 80 minutes. To investigate the impact of real oil composition on the desulfurization process, various unsaturated and N-compounds (pyrrole and pyridine) were added to mixed model oil. Finally, PW/K10 was recycled five times, and the results indicated no significant decrease in catalytic activity. Introductio

<b>Acetylation and oxygenation transformations catalyzed by silica-supported dodecatungstophosphoric acid</b>

Acetylation of alcohols in refluxing ethyl acetate, and oxidation of aniline and cyclohexanol with 34 % H₂O₂ in the presence of H₃PW₁₂O₄₀ and its supported forms on SiO₂ (20 %, 40 %, and 60 % by weight) as active solid acid catalysts were performed under mild reaction conditions with moderate to good yields and with 100 % selectivity. It is found that the supported H₃PW₁₂O₄₀ was in general 1.4-2.3 times more efficient than the unsupported catalyst in the acetylation and oxygenation reactions. Easy work-up and effective recycling of the heterogeneous catalyst were distinct advantages of the catalytic heterogeneous system

Detection of virulence genes among Staphylococcus saprophyticus isolated from women with urinary tract infections: first report from Iran

Abstract Objective The purpose of the present study was to investigate the biofilm production, and the presence of virulence genes and biochemical characteristics among the S. saprophyticus clinical isolates. A total of 35 clinical isolates of S. saprophyticus were collected from patients referred to several hospitals. By the crystal violet staining method, the capability of biofilm formation was performed. The genes associated with surface of S. saprophyticus were investigated by the PCR-sequencing techniques. Hemagglutination and lipase activity assays were also performed. Results The results of crystal violet staining assay showed that 32 isolates (91%) form biofilm. Moreover, seven (20%), 13 (37%), and 12(34%) isolates were categorized as weak, moderate, and strong biofilm producers, respectively. virulence genes including UafA, Aas and Ssp had an overall prevalence of 88%, 91% and 80%, respectively. None of the isolates exhibited lipolytic activities. Regarding hemagglutination properties, only 11 (31%) isolates demonstrated hemagglutination of sheep erythrocytes. The results of this study indicate a high prevalence of UafA and Aas genes that can enhance the pathogenicity of S. saprophyticus, and Identification and better understanding of the functions of these genes can be used for therapeutic purposes. Maybe in the future we will be switch to anti-adhesion therapy because of drug resistance

Preparation and characterization of nanocomposite of graphitic carbon nitride and TiO2 as a porous support for nano catalyst for desulfurization process

A novel heterogeneous nanocatalyst H3PW12O40/TiO2/g-C3N4 (PW/TiO2/CN) was successfully synthesized by immobilization of PW on TiO2/CN nanocomposite, and characterized by SEM, BET, FT-IR, XRD, EDX, TEM and ICP. Catalytic performance of the as-prepared catalyst was investigated for the selective oxidation of sulfides to sulfoxides and sulfones in the presence of H2O2 as oxidant with good conversion and high selectivity. The main factors influencing the ability for selective oxidation of sulfides were studied, including reaction temperature, amounts of the catalyst, H2O2 and type of the reaction solvent. Catalytic oxidation of the different model oils containing dibenzothiophene (DBT), benzothiophene (BT) and thiophene (T) into corresponding sulfone was also studied. Effects of different extractive solvents, aromatics, alkenes and nitrogen compounds on the oxidative desulfurization processes (ODS) were also studied. In addition, reducing the level of sulfur content in real oil was investigated. The recyclability of the PW/TiO2/CN nanocatalyst for various cycles without a significant loss of activity was proved. The heterogeneity of the as-prepared catalyst was confirmed by leaching tests. Keywords: Graphitic carbon nitride, Extraction, Tetrabutyl titanate, Heteropoly acid, Oxidative desulfurization, Oi

Oxidative desulfurization of diesel by potato based-carbon as green support for H5PMo10V2O40: Efficient composite nanorod catalyst

The C@POM (carbon@polyoxometalate) containing H3PMo12O40 (PMo12), H5PMo10V2O40 (PMo10V2), H6PMo9V3O40 (PMo9V3), H7PMo8V4O40 (PMo8V4), H3PW12O40 (PW), and H4SiW12O40 (SiW) were prepared from natural potato as green, and cheap catalyst support source. The C@PMo10V2 was found to be a unique, effective, and eco-friendly catalyst for selective oxidation of sulfides, using 30% aq. H2O2. C@PMo10V2 composite was characterized by X-ray diffraction spectroscopy (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectrophotometry, zeta sizer, and zeta potential. The XRD results show that during immobilization PMo10V2 on the carbon catalyst support (CCS), the crystallite structure of PMo10V2 and CCS was not changed. The SEM results show that PMo10V2 crystals deposited on the surface CCS rods as composite nanorod structure. A variety of sulfides, sulfur-containing model and real oil were oxidized with the C@PMo10V2/H2O2 at room temperature. Recovered catalyst show excellent activity for at least four repeating cycles

<b>KSF-supported heteropoly acids catalyzed one-pot synthesis of α-aminonitriles</b>

In the presence of KSF-supported heteropoly acid as a heterogeneous, reusable and inexpensive catalyst, three-component reactions between aldehydes or ketones, amines, and trimethylsilyl cyanide preceded to afford &alpha;-aminonitriles in excellent yields, very short reaction times, and low loading of catalyst. This catalyst was highly selective and other functional groups including carbon-carbon double bond, and heterocyclic moieties did not affect the reaction

Antimicrobial Resistance Patterns of Staphylococcus saprophyticus Isolates Causing Urinary Tract Infections in Gorgan, North of Iran

Background and objectives: Urinary tract infection (UTI) is one of the most common bacterial infections. Staphylococcus saprophyticus is a common Gram-positive bacterium that causes uncomplicated UTIs in women. The present study aimed to study the drug resistance pattern and phenotypic and genotypic variation of S. saprophyticus isolates from women with UTI in Gorgan, northern Iran. Methods: This study was performed from May 2018 to September 2020. During this time,   35 S. saprophyticus strains were isolated from patients with UTI. The antimicrobial patterns of the isolates were determined by a conventional method. Phenotypic criteria such as pigment production, mannitol fermentation, urease production, and 16SrRNA gene valuation were studied. Results: All isolates were sensitive to nitrofurantoin, gentamicin, and linezolid. S. saprophyticus isolates showed the highest level of resistance to penicillin (85.7%) and erythromycin (51.4%). A variation was detected among S. saprophyticus isolates in terms of pigment production i.e. about 51.4% showed yellow pigment in Muller Hinton agar, and 62.9% of the isolates were able to ferment mannitol sugar. Of 11 isolates that were sequenced for the 16SrRNA gene, only two isolates showed different patterns. Conclusion: Nitrofurantoin and trimethoprim-sulfamethoxazole are the antibiotics of choice for the treatment of UTI caused by S. saprophyticus in the study area. Due to the phenotypic and genotypic differences among S. saprophyticus isolates, typing of S. saprophyticus at the subspecies level is recommended

Additional file 1 of Combination antimicrobial therapy: in vitro synergistic effect of anti-staphylococcal drug oxacillin with antimicrobial peptide nisin against Staphylococcus epidermidis clinical isolates and Staphylococcus aureus biofilms

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