17 research outputs found

    Molybdatophosphoric acid as an efficient catalyst for the catalytic and chemoselective oxidation of sulfides to sulfoxides using urea hydrogen peroxide as a commercially available oxidant

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    An efficient procedure for the chemoselective oxidation of alkyl (aryl) sulfides to the corresponding sulfoxides using urea hydrogen peroxide (UHP) in the presence of a catalytic amount of molybdatophosphoric acid at room temperature is described. The advantages of described method are: generality, high yield and chemoselectivity, short reaction time, low cost and compliment with green chemistry protocols

    Electrochemical detection of sulfite in food samples

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    In various pharmaceutical and food industries, sulfite is utilized for the inhibition of nonenzymatic and enzymatic browning. Also, in brewing industries, it acts as an antioxidizing and antibacterial agent. Several toxic and adverse reactions, including vitamin deficiency, hypersensitivity, and allergic diseases, have been attributed to sulfite ingestion that may cause dysbiotic oral and gut microbiota events. Thus, the content of sulfite in foods must be controlled and monitored, and it is essential to find a specific, reproducible, and sensitive method to detect sulfite. Some analytical solutions are being tested to quantify sulfite. However, due to their advantage over traditional techniques, electroanalytical techniques are attracting much attention because they are simple, fast, affordable, and sensitive to implement. In addition, by the electrode modification, the morphology and size can be controlled, resulting in the miniaturization to be used in portable electrochemical devices. Therefore, the present review addressed some articles on the electrooxidation of sulfite from real samples using various electrochemical sensors

    Inulin-Grafted Stearate (In-g-St) as the Effective Self-Assembling Polymeric Micelle: Synthesis and Evaluation for the Delivery of Betamethasone

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    Background. Betamethasone as a corticosteroid drug is commonly used for the treatment of rheumatoid arthritis. Unfortunately, betamethasone is a low water-soluble drug and its efficacy is low. So an attractive strategy is the targeted delivery of betamethasone to the damaged joint using polymeric micelle-based carriers. Methods. Inulin-grafted stearate (In-g-St) was synthesized via the reaction of stearoyl chloride and inulin, then characterized by FT-IR and H-NMR. In-g-St forms micelles in the presence of betamethasone. The prepared polymeric micelles were characterized for size, zeta potential, drug loading, particles’ morphology, critical micelle concentration (CMC), and encapsulation efficiency. So sustained release polymeric micelles of betamethasone were developed by employing In-g-St. Results. The measurement of particle size showed a mean diameter of 60 and 130 nm for 10% and 20% drug-loaded micelles, respectively, and SEM showed that the particle’s morphologies are spherical. Zeta potential measurement for the drug-containing micelles showed a value of -11.8 mV. Drug loading efficiency and the encapsulation efficiency were 6.36% and 63.6%, as well as 18.97% and 94.88% for 10% and 20%, respectively. 20% drug-loaded polymer showed a small burst release of betamethasone at the first 3 h which was followed by sustained release in the next 24 h. Furthermore, the formula with 10% exhibited good sustained release properties except for the minor initial burst release. Conclusion. Data from the zeta potential, CMC, drug loading capacity, and in vitro drug release studies indicated that In-g-St polymeric micelles can be suitable candidates for the efficient delivery of hydrophobic drugs like betamethasone

    A comparative study of academic members� and students� perspectives of the formative evaluation by quiz test

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    Background: The quiz is one of the most commonly formative evaluations to attaining the educational goals. This study aimed to compare the academic members� and students� perspectives about the formative evaluation by quiz and provide feedback to improve learning at Hamadan University of Medical Sciences. Methods: In this survey, 27 teachers and 180 students were included by convenience sampling. In order to achieve specific goals, a self-report questionnaire was developed according to the literature. The questionnaire contained three parts: a- demographic characteristic (7 items) for both students and teachers, b- 25 items to determine the participants views about the quiz characteristics as how to organize (9 items), holding time (4 questions), feedback (6 questions), better strategies to organize (4 questions), and c- 18 questions on a Likert scale to determine their attitude. Content and face validity of the instrument were approved by the faculty members and its Cronbach's alpha coefficient was 0.85. Data collected were analyzed by 16-Spss software.Results: This study showed that the view of teachers and students were similar in the most items, however, in some cases, significant differences were obtained. The mean scores of the attitudes indicated the positive attitudes of teachers and students, the Mann-Whitney test (with P=0.59) did not show significant differences between two groups. Conclusion: In attention to the research findings on the quiz characteristics and particularly the participants� positive attitudes to quiz, it can be said that the quiz should be considered as a simple and economic formative evaluation in medical education

    H2O2 as green and environmentally benign reagent for the oxidation of TMS ethers, THP ethers, and alcohols in the presence of {[K.18-Crown-6]Br3}n

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    In the presence of {[K.18-Crown-6]Br3}n, a unique tribromide reagent, trimethylsilyl (TMS) ethers, tetrahydropyranyl (THP) ethers, and alcohols were oxidized to their corresponding aldehydes and ketones in H2O2. One-pot deprotection and oxidation of TMS ethers/THP ethers were performed directly and the conversion was complete. Avoiding the isolation of the corresponding alcohol as an intermediate step, the direct transformation of such substrates to carbonyls is the main aim of this work. {[K.18-Crown-6]Br3}n regeneration was performed via the addition of Br2 to the residue of the reaction and recrystallization in acetonitrile

    Organic Solid Acid/NaNO2: An Efficient System for the Oxidation of Urazoles and Bis-Urazoles under Mild and Heterogeneous Conditions

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    Various organic solid acids/NaNO2 were used as effective oxidizing agents for the oxidation of urazoles and bis-urazoles to their corresponding triazolinediones under mild and heterogeneous conditions at room temperature with good-to-excellent yields

    Melamine-(H 2

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