54 research outputs found

    Behavior of Acetylenic Ketones and Esters towards Aroylisothiocyanates in Polar Solvent (Part I)

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    Reactions of aroylisothiocyanates 2a,b with acetylenic ketones 1a-c gave a mixture of thiocyanatoprop-2-en-1-ones 3a-c, (E,Z)-3,3’-thiodi(1-aryl-3-phenylprop-2-en-1-ones) 4a-c, 4-methoxybenzoylthiourea (6), 3-(4-methoxybenzamido)-1,3-diphenylprop-2-en-1-one (7a) and 2-phenylacetamide (8). Treatment of 2a,b with acetylenic esters 1d,e afforded a mixture of (Z,Z)-3,3’-thiodiacrylates 5a,b, the thiourea 6, 3-(2-phenylacetamido)-3-phenylprop-2-enoate (7b) and 8. Reacting 1f with 2a yielded tetrahydropyrimidine derivatives 9 and 6. On the other hand, with 2b yielded 8

    The Relationship Between Metacognition and Self-regulation in Young Children

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    AbstractThe purpose of this study was to explore the relationship between theory of mind (ToM) (intention and false belief), metacognition, and self-regulation in preschool children. A related purpose was to investigate the gender and age differences. The sample of the study consisted of 87 preschool children in Southern Egypt. The instruments consisted of two theory-of-mind tasks (intention and false-belief situations), three tasks of metacognition and self- regulation (puzzle arrangement and sorting tasks). Metacognition and self-regulation tasks were evaluated using The Checklist of Independent Learning Development (CHILD, Whitebread et al., 2009). Correlations, t-test, and stepwise multiple regression analyses, using SPSS 18.0, were employed to answer the questions of the study. The results indicated no gender differences in the overall performance on the study variables. A developmental effect was found in favour of the older children in the intention task, puzzle arrangement task, and the total score of ToM. The second task predicted the false-belief task. The findings of the study are discussed and further venues for future research in this area are suggested

    Liquid chromatography-electro spray ionization tandem mass spectrometry for simultaneous determination of Moexipril and its active metabolite Moexiprilat in human plasma

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    A selective, sensitive, and rapid liquid chromatography-electro spray ionization tandem mass spectrometry method has been developed and subsequently validated for the simultaneous determination of Moexipril (MOX), and its active metabolite Moexiprilat (MOXT) in spiked human plasma, using Benazepril (BENZ) as an internal standard (IS). Various modes were tried and the Multiple Reaction Monitoring (MRM) mode was found the most suitable one. The two analytes and Benazepril (IS) were extracted from human plasma by simple protein precipitation using acetonitrile as the precipitating solvent. The stationary phase used was a C18 Sunfire column while water and acetonitrile at 0.1% formic acid (30:70, v:v) was used as a mobile phase. The flow rate used was 0.8 mL/min. Food and Drug Administration guidelines were followed for the method validation. The linearity range was found to be 0.5-100 ng/mL for MOX and 5-200 ng/mL for MOXT and the correlation coefficient was more than 0.9980 for each analyte. Results for accuracy and precision showed satisfactory results. Also the method was compared with reported HPLC method and no significant difference was found

    Simultaneous spectrophotometric determination of drugs lacking peak maxima in their zero-order profiles by graphical or statistical representation of data

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    Trandolapril has no sharp peak in its zero-order spectrum, therefore it is difficult to be measured by direct spectrophotometry. In this study, direct univariate spectrophotometric methods were developed and validated for determination of Trandolapril and Verapamil combination in pure and tablet dosage forms. The first method for measuring both Trandolapril and Verapamil is Absorbance Subtraction (AS), this method depends on the presence of iso-absorptive point in the zero-order curve at 217 nm. It has the advantage of measuring the concentration of both Trandolapril and Verapamil from unified regression equation at the iso-absorptive point. The second, third and fourth methods were applied on the first order spectra of the studied drugs. Second method is Derivative Subtraction (DS) for Trandolapril and Derivative subtraction followed by spectrum subtraction (DS-SS) for Verapamil. The third and fourth methods are constant value and concentration value methods. In the concentration value method, the concentration of the drugs is determined from the graphical representation without the use of regression equations. All the developed methods were validated as per International Conference on Harmonization guidelines and the results proved that the developed methods are simple, accurate, and selective. Moreover, a statistical comparison between the developed methods and a reference method was done. Also, One-way ANOVA statistical test was done between all the proposed spectrophoto-metric methods and results showed no significant differences

    Student Teachers’ Beliefs about Developmentally Appropriate Practices and Their Relationship with some Demographic Variables

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    The purpose of this study was to investigate female student teachers’ beliefs towards developmentally appropriate practices (DAP) and the relationship between these beliefs and the GPA. It also aimed to investigate the differences in DAP beliefs among female student teachers at different years(lst through 4th year). Study sample consisted of 60 female students selected from the Early Child Education program at the College of Education, Sultan Qaboos University from different years (lst through 4th year). The study used the three subscales of teacher beliefs scale: (a) integrated/social- cultural curriculum, (b) teacher-directed / basic school skills and (c) child-centered learning. The results indicated a significant correlation at p=0.01 among the three TBS subscales, the total score and GPA. Significant differences were also found between the different years where the beliefs of the second, third and fourth year students were better than first year students beliefs on all subscales and the total score

    Eco-Friendly Separation of Antihyperlipidemic Combination Using UHPLC Particle-Packed and Monolithic Columns by Applying Green Analytical Chemistry Principles

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    Efficient separation of pharmaceuticals and metabolites with the adequate resolution is a key factor in choosing the most suitable chromatographic method. For quality control, the analysis time is a key factor, especially in pharmacokinetic studies. High back pressure is considered as one of the most important factors in chromatography’s flow control, especially in UHPLC. The separation of the anti-hyperlipidemic mixtures was carried out using two columns: a column silica-based particle packed UHPLC and a monolithic column. The systematic suitability of the two columns was compared for the separation of Fenofibrate, its active metabolite, Fenofibric acid and Pravastatin using Atorvastatin as an internal standard. Separation on both columns was obtained using ethanol: buffer potassium dihydrogen orthophosphate pH = 3 (adjusted with orthophosphoric acid) (75:25 v/v) as mobile phase and flow rate 0.8 mL/min. The analytes’ peak detection was achieved by using a PDA detector at 287 nm, 214 nm, 236 nm, and 250 nm for Fenofibrate, Fenofibric acid, Pravastatin, and Atorvastatin, respectively. Reduction of back-pressure was achieved with the monolithic column, where the analytes could be completely separated in less than 1.5 min at a flow rate of 5 mL/min. The principles of Green Analytical Chemistry (GAC) were followed throughout the developed method using environmentally safe solvents

    Improvement of Soil Properties, Growth of Cucumber and Protection against Fusarium Wilt by Piriformospora indica and Two Industrial Organic Wastes

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    The current work was focused on characterizing bagasse ash (BA) and press mud (PM) as soil amendments and to study their effect in combination with the endophytic fungus Piriformospora indica on Fusarium wilt (FW) of cucumber caused by Fusarium oxysporum f. sp. cucumerinum (Fo). Whereas BA and PM improved almost all physico-chemical properties of the soil evaluated, seed treatment with P. indica had no such effect. In shake culture in potato dextrose broth (PDB) medium amended with aqueous extracts of BA and PM, alone or in combination, production mycelial mass of Fo was significantly decreased by PM extract, while production mycelial mass of P. indica was highly improved. The colonization rate of cucumber roots by P. indica as determined by microscopy was highly increased by increasing amounts of BA, PM and BA+PM added to the soil. Seed treatment of cucumber with P. indica before plant cultivation in non-amended soil significantly decreased the disease severity of FW and improved plant growth. When seed treated with P. indica was sown into soil amended with BA, PM or the combination of both, the disease severity was even more reduced than after seed treatment with P. indica alone. In this respect, amendment with PM was more effective than with BA, and the combinations were more effective than the single treatments. Hence, there is a scope to integrate PM and BA as soil amendments in combination with P. indica for eco-friendly FW management, improving soil properties and growth of cucumber plants

    Development of a Robust UPLC Method for Simultaneous Determination of a Novel Combination of Sofosbuvir and Daclatasvir in Human Plasma: Clinical Application to Therapeutic Drug Monitoring

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    A rapid and selective UPLC-DAD method was developed and validated for simultaneous analysis of the novel two-drug combination DarvoniÂź for the treatment of HCV: Sofosbuvir (SF)/Daclatasvir (DC) in human plasma using Ledipasvir as internal standard (IS) where the extraction process was conducted using automated SPE. Although the analysis of the combination after concomitant oral intake of two tablets of SF and DC individually was reported in literature, yet simultaneous analysis of this new combination in human plasma after a single oral dose was not previously reported. The adopted chromatographic separation was achieved on WatersÂź Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7 ”m) as a stationary phase using isocratic elution using a mobile phase system of ammonium formate (pH 3.5; 5 mM) and acetonitrile (60:40 v/v) pumped at a flow rate of 0.2 mL.min−1. The UV detection was carried out at 261 nm for SF and 318 nm for DC and IS. SF was eluted at 1.123 min while DC was eluted at 3.179 min. The proposed chromatographic method was validated in accordance with guidelines of FDA for bioanalytical method validation. A linear range was achieved in the range of 25-6400 and 50-12800 ng.mL−1 for SF and DC, respectively. The proposed UPLC-DAD method was found to be accurate with % bias ranging between -10.0-7.2 for SF and -6.9-8.0 for DC. Also it was proved to be precise with % CV for intraday precision ranging between 3.8-9.6 for SF and 2.8-9.2 for DC whereas interday precision ranged between 5.1-9.3 for SF and 3.7-9.1 for DC. Moreover, % extraction recovery ranged between 90.0-107.2 for SF and 93.1-108.0 for DC using the suggested method. The adopted chromatographic method was successfully applied to the therapeutic drug monitoring of SF and DC in healthy volunteers after the oral intake of one DarvoniÂź tablet

    Application of two different spectrophotometric approaches for the determination of a new antihypertensive combination: Graphical and statistical representation of the data

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    SpeciïŹc, and precise spectrophotometric methods are developed and validated for the simultaneous determination of the binary antihypertensive mixture nebivolol hydrochloride and valsartan in the zero-order spectrum. The methods applied for the determination of this antihypertensive mixture are constant center spectrophotometric resolution technique, constant center spectrum subtraction resolution technique, and advanced concentration value. Nebivolol hydrochloride was determined by its zero order spectra at 280 and 213 nm while for valsartan it determined by its zero order spectra at 250 nm. All developed methods were applied for the determination of the cited drugs in the pharmaceutical formulation and the results obtained were statistically compared with each other and with those of the reported method. The comparison showed that there is no significant difference between the proposed methods and the reported method regarding both accuracy and precision

    Preventative and Curative Effects of Several Plant Derived Agents Against Powdery Mildew Disease of Okra

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    The preventative and curative effects of some plant derived agents based on plant extracts or essential oils were studied at different concentrations against Erysiphe cichoracearum DC. ex Merat, the causal pathogen of okra powdery mildew by the detached leaf-disk and potted plants bioassays. Through detached leaf-disk assay, the highest mean preventative effect (97.74%) was recorded by neem seed oil followed by jojoba oil (89.82%) and extract of Rynoutria sachalinensis (82.77%). Neem seed oil at 1% was the most effective agent followed by jojoba oil and extract of R. sachalinensis at 1.5% and 2%, respectively, where they suppressed E. cichoracearum completely. Potted plants assay revealed that neem seed oil, jojoba oil and extract of R. sachalinensis as well as the fungicide (active ingredient dinocap) showed higher preventative efficacy at all leaf olds treated after 7 and 14 days of inoculation as compared with extracts of henna and garlic. Moreover, the preventative efficacy partly remained apparent after 14 days of inoculation at all leaf olds tested. In field trials through 2010 and 2011 growing seasons, when the first symptoms of powdery mildew appeared naturally, 1.5% jojoba oil, 2% extract of R. sachalinensis and 1% neem seed oil were sprayed individually twice on grown plants to evaluate their efficacy on controlling powdery mildew, growth and yield of okra. Resulted showed that neem seed oil was the most effective agent and highly decreased the disease severity to 29.92%, recorded the highly curative effect (68.15%) and also improved plant growth and pods yield
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