1,971 research outputs found
Voltammetric determination of melatonin in tablet dosage forms and human serum
The electrochemical oxidation of melatonin is studied in Britton-Robinson buffer in the pH range 2.2-11.8 by cyclic voltammetry at glassy carbon electrode. Three irreversible, diffusion-controlled oxidation peaks were obtained. The utility of using differential pulse and square wave techniques for determination of melatonin was examined. Different parameters affecting the peak current were analylzed and at optimum conditions, linear calibration plots from 0.02-0.5 mM and 0.04 to 0.5 mM of melatonin were obtained applying the two techniques, respectively. The differential pulse mode was successfully applied to the determination of melatonin in commercial tablets containing about three-folds of vitamin B6 without previous separation. The same technique was also used for melatonin determination in human serum with acceptable accuracy.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Voltammetric determination of melatonin in tablet dosage forms and human serum
The electrochemical oxidation of melatonin is studied in Britton-Robinson buffer in the pH range 2.2-11.8 by cyclic voltammetry at glassy carbon electrode. Three irreversible, diffusion-controlled oxidation peaks were obtained. The utility of using differential pulse and square wave techniques for determination of melatonin was examined. Different parameters affecting the peak current were analylzed and at optimum conditions, linear calibration plots from 0.02-0.5 mM and 0.04 to 0.5 mM of melatonin were obtained applying the two techniques, respectively. The differential pulse mode was successfully applied to the determination of melatonin in commercial tablets containing about three-folds of vitamin B6 without previous separation. The same technique was also used for melatonin determination in human serum with acceptable accuracy.Colegio de Farmacéuticos de la Provincia de Buenos Aire
The Breathing Human Infrastructure: Integrating Air Quality, Traffic, And Social Media Indicators
Outdoor air pollution is a complex system that is responsible for the deaths of millions of people annually, yet the integration of interdisciplinary data necessary to assess air quality\u27s multiple metrics is still lacking. This case study integrates atmospheric indicators (concentrations of criteria pollutants including particulate matter and gaseous pollutants), traffic indicators (permanent traffic monitoring station data), and social indicators (community responses in Twitter archives) representing the interplay of the three critical pillars of the United Nations\u27 Triple Bottom Line: environment, economy, and society. During the watershed moment of the COVID-19 pandemic lockdowns in Florida, urban centers demonstrated the gaps and opportunities for understanding the relationships, through correlations rather than causations, between urban air quality, traffic emissions, and public perceptions. The relationship between the perception and the traffic variables were strongly correlated, however no correlation was observed between the perception and actual air quality indicators, except for NO2. These observations might consequently infer that traffic serves as people\u27s proxy for air quality, regardless of actual air quality, suggesting that social media messaging around asthma may be a way to monitor traffic patterns in areas where no infrastructure currently exists or is prohibited to build. It also indicates that people are less likely to be reliable sensors to accurately measure air quality due to bias in their observations of traffic volume and/or confirmation biases in broader social discourse. Results presented herein are of significance in demonstrating the capacity for interdisciplinary studies to consider the predictive capacities of social media and air pollution, its use as both lever and indicator of public support for air quality legislation and clean-air transitions, and its ability to overcome limitations of surface monitoring stations
Multi-level Multi-objective Quadratic Fractional Programming Problem with Fuzzy Parameters: A FGP Approach
The motivation behind this paper is to present multi-level multi-objective quadratic fractional programming (ML-MOQFP) problem with fuzzy parameters in the constraints. ML-MOQFP problem is an important class of non-linear fractional programming problem. These type of problems arise in many fields such as production planning, financial and corporative planning, health care and hospital planning. Firstly, the concept of the -cut and fuzzy partial order relation are applied to transform the set of fuzzy constraints into a common crisp set. Then, the quadratic fractional objective functions in each level are transformed into non-linear objective functions based on a proposed transformation. Secondly, in the proposed model, separate non-linear membership functions for each objective function of the ML-MOQFP problem are defined. Then, the fuzzy goal programming (FGP) approach is utilized to obtain a compromise solution for the ML-MOQFP problem by minimizing the sum of the negative deviational variables. Finally, an illustrative numerical example is given to demonstrate the applicability and performance of the proposed approach
Pattern and severity of childhood unintentional injuries in Ismailia city, Egypt
In 2009, more than 746 000 injury cases were registered in the Ministry of Health hospitals in Egypt, with an injury rate of 1 004/100 000 population. Around 38% of all injuries occur among children and young adults less than 20 years of age. Furthermore, more than 20 000 people lose their lives to injuries every year (27/100 000). However, these data lack information on injury pattern, severity, provided care and outcome of injuries, which are essential data for planning injury control programmes.The aim of this study was to determine the frequency, nature and risk factors of childhood injuries in the Suez Canal University Hospital Emergency Department.The study included a total of 551 children of 12 years of age. The most common causes of injuries among those children were falls (60%), road traffic injuries (15%) and burns (7%). The most commonly sustained injuries were fractures (23%), cuts or open wounds (21%), sprains (20%) and burns (13%). Overall injury severity scores (ISSs) were low across all injury types, except road traffic injuries (RTIs). The majority of patients were treated and discharged without disability (50.5%), while 7.4% had long-term temporary disability that lasted for more than 6 weeks, and 1.9% sustained permanent disability. There were two deaths (0.4% proportionate mortality); both of them were due to falls from a height.In conclusion, the study confirms the feasibility of documenting the burden of childhood injuries on health systems in Egypt. It also confirmed the need for tailored injury-prevention research in Egypt. The resulting data should encourage interventional trials to be conducted, appropriate injury-prevention strategies to be implemented and timely interventions to be planned.Keywords: Childhood unintentional injuries, Egypt, risk factors
Some Features of Joint Confidence Regions for the Parameters of the Inverse Weibull Distribution
In this paper, we will study the joint confidence regions for the parameters of inverse Weibull distribution in the point of view of record values. One of the applications of the joint confidence regions of the parameters is to find confidence bounds for the functions of the parameters. Joint confidence regions for the parameters of extreme value distribution are also discussed. In this way we will discus some numerical examples with real data set and simulated data, to illustrate the proposed method. A simulation study is performed to compare the proposed joint confidence regions. Keywords: The joint confidence regions, confidence bounds; inverse Weibull distribution, extreme value distribution
An Investigation of Inference of the Generalized Extreme Value Distribution Based on Record
In this article, the maximum likelihood and Bayes estimates of the generalized extreme value distribution based on record values are investigated. The asymptotic confidence intervals as well as bootstrap confidence are proposed. The Bayes estimators cannot be obtained in closed form so the MCMC method are used to calculate Bayes estimates as well as the credible intervals. A numerical example is provided to illustrate the proposed estimation methods developed here. Keywords: Generalized extreme value distribution, Record values, Maximum likelihood estimation, Bayesian estimation
Voltammetric determination of melatonin in tablet dosage forms and human serum
The electrochemical oxidation of melatonin is studied in Britton-Robinson buffer in the pH range 2.2-11.8 by cyclic voltammetry at glassy carbon electrode. Three irreversible, diffusion-controlled oxidation peaks were obtained. The utility of using differential pulse and square wave techniques for determination of melatonin was examined. Different parameters affecting the peak current were analylzed and at optimum conditions, linear calibration plots from 0.02-0.5 mM and 0.04 to 0.5 mM of melatonin were obtained applying the two techniques, respectively. The differential pulse mode was successfully applied to the determination of melatonin in commercial tablets containing about three-folds of vitamin B6 without previous separation. The same technique was also used for melatonin determination in human serum with acceptable accuracy.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Bioactive compounds from Acokanthera oblongifolia
One cardiotonic glycoside, three triterpenes and one steroidal glycoside were isolated from Acokanthera oblongifolia fruits (pericarp) growing in Libya. Their structures were investigated by extensive application of IR, MS, 1DNMR and 2DNMR spectroscopy. The isolated compounds have evidenced in-vitro cytotoxicity on selected human cell lines (A-549, H-1299) when compared to doxorubicin. Keywords: Cardenolide; Acokanthera oblongifolia; antitumor activity; lung carcinoma cell line (A-549, H-1299)
Effects of glycoprotein IIb/IIIa receptor blocker (tirofiban) in acute coronary syndromes angiographic, scintigraphic and molecular biology studies
- …