Investigation Of Several Variables Research Articles

A Cannabinoid Fuel Cell Capable of Producing Current by Oxidizing Δ9-Tetrahydrocannabinol.

We report the development of a current-producing H-Cell that relies on the oxidation of Δ9-tetrahydrocannabinol (THC), which is the primary psychoactive ingredient in marijuana. We found through systematic investigation of several variables that power densities could be improved 5-fold. Moreover, a real-time signal in a rudimentary THC sensor was observed at varying concentrations of THC. Given the growing societal interest in the detection of THC, our studies lay the foundation for the development of a marijuana breathalyzer.

A Core-Shell Amino-Functionalized Magnetic Molecularly Imprinted Polymer Based on Glycidyl Methacrylate for Dispersive Solid-Phase Microextraction of Aniline

A core-shell amino-functionalized glycidyl methacrylate magnetic molecularly imprinted polymer (MIP) was synthesized by the suspension polymerization/surface imprinting method and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), mercury porosimetry, nitrogen gas adsorption–desorption, and elemental analysis. This MIP was used as the sorbent in dispersive solid-phase microextraction (DSPME) of aniline from textile wastewater prior to high-performance liquid chromatography-mass spectrometry (HPLC-MS) measurements. Since aniline is toxic and a probable human carcinogen, its determination in water is of great significance. This is a challenging task because aniline is usually present at trace levels. The effects of different DSPME variables on the preconcentration efficiency have been studied by using the Plackett–Burman screening design of experiments (DoE) followed by response surface methodology optimization using the Box-Behnken design. Thus, DoE enabled the investigation of several variables simultaneously. Under optimized conditions, aniline was effectively and selectively separated by a small amount of the DSPME sorbent and detected in real textile wastewater samples. The method detection limit of 1 ng mL−1 was attained, with good method linearity and acceptable recovery and precision. The results showed that the studied MIP could be a reliable DSPME sorbent for efficiently analyzing trace aniline in real wastewater samples.

Efficient microscale synthesis of [18F]-2-fluoro-2-deoxy-d-glucose

• [ 18 F]fluorination efficiency can be enhanced by flexible aliphatic tertiary alcohols. • [ 18 F]FDG was synthesized from mannose triflate on a micro-scale level with a higher radiochemical yield within shorter time. • Radiosynthesis of [ 18 F]FDG was influenced by ratio of tertiary alcohols and DMSO. • The concentrations of mannose triflate and bases influence on the microscale substitution reaction yield. Microscale radiosynthesis of [ 18 F]FDG using a miniaturized device has been reported as a promising tool for positron emission tomography. However, small scale [ 18 F]FDG radiosynthesis on micro fluidic devices need to be studied further to evaluate its usefulness. This paper analyzes several micro-scale reactions of [ 18 F]FDG with various reaction conditions to achieve a higher radiochemical yield of [ 18 F]FDG. Synthesis of [ 18 F]FDG was carried out using mannose triflate on a microchip, and the crude product was purified via cartridge purification. The reaction conditions were optimized by examining several factors including reaction solvents, bases and their concentrations, that influence microscale radio synthesis of [ 18 F]FDG. Based on the investigation of several variables and their effects on the radio-synthetic reaction, [ 18 F]FDG was successfully synthesized on a micro-scale level with a radiochemical yield of 71% and within shorter time frame than that of the traditional method. Moreover, purity of the product was greater than 99%. These results show that the new guideline provides a more efficient and effective method of microscale [ 18 F]FDG radiosynthesis.

PRECEDE 모형을 이용한 구강건강의 영향요인에 대한 진단적 연구

Objectives : This study aimed to improve school health program by investigation of several variables through educational diagnostic factors which influence the level of subjective oral health perception and DMFT of students on the basis of PRECEDE model. Methods : A total of 286 high school students in Busan completed the self-reported questionnaire from September 3 to 28 in 2012. Results : 1. Social and epidemiologic diagnosis suggested that the level of subjective oral health perception of male students was not better than that of female students and DMFT number of the male was more than that of the female(p<0.001)(p<0.001). 2. Oral health diagnosis indicated that once a day tooth brushing group showed lower level of oral health perception(p<0.001) and high DMFT number(p<0.001). 3. Predisposing factor of educational diagnosis implied that more than 4 times a day snack intake group and sweet diet and soda friendly group showed lower level of oral health perception and high DMFT number(p<0.001). 4. Tooth brushing of the reinforcing factors had the most important effect on the level of oral health perception and the number of dental caries. Daily snack intake was the most important effect on DMFT number. Conclusions : The informed consent from each family was the important factor in implementing PRECEDE model. School health program improved oral health care. Oral health program can correct the risk oral health behavior in children and adolescents.

The status of academic integrity amongst nursing students at a nursing education institution in the Western Cape

Honesty is regarded as a basic ethical value in all educational programmes, and academic integrity is of undisputed importance in educational environments. The literature reviewed revealed that academic dishonesty is wide-ranging and also encountered in the nursing education environment. This phenomenon is of concern to the nursing fraternity because of the proven positive correlation between unethical academic practices and future unethical professional behaviour. Limited research data regarding academic dishonesty at nursing education institutions in South Africa and this correlation motivated the present study. The purpose was to examine the status of academic integrity amongst nursing students at a nursing education institution in the Western Cape. Formulated objectives guided investigation of several variables which impact upon academic integrity, for example the incidence of and student perceptions around academic dishonesty. A quantitative, descriptive survey design was used, with a self-reported questionnaire (based on literature review and study objectives) designed to obtain information about academic dishonesty. Provision was also made for qualitative input from the respondents by including three open-ended questions. It was found that academic dishonesty was a reality at the nursing education institution where this study was done. Cheating associated with plagiarism and assignments was identified as the main problem area. An unacceptably high level of dishonesty in completion of practical records was also an area of concern. The main recommendations are development and implementation of a code of honour and implementation of comprehensive academic integrity policies at the nursing education institution, with practical measures aimed at combating cheating in tests and examinations.

Approaches to improve angiogenesis in tissue‐engineered skin

A problem with tissue-engineered skin is clinical failure due to delays in vascularization. The aim of this study was to explore a number of simple strategies to improve angiogenesis/vascularization using a tissue-engineered model of skin to which small vessel human dermal microvascular endothelial cells were added. For the majority of these studies, a modified Guirguis chamber was used, which allowed the investigation of several variables within the same experiment using the same human dermis; cell type, angiogenic growth factors, the influence of keratinocytes and fibroblasts, mechanical penetration of the human dermis, the site of endothelial cell addition, and the influence of hypoxia were all examined. A qualitative scoring system was used to assess the impact of these factors on the penetration of endothelial cells throughout the dermis. Similar results were achieved using freshly isolated small vessel human dermal microvascular endothelial cells or an endothelial cell line and a minimum cell seeding density was identified. Cell penetration was not influenced by the addition of angiogenic growth factors (vascular endothelial growth factor and basic fibroblast growth factor); similarly, including epidermal keratinocytes or dermal fibroblasts did not encourage endothelial cell entry, and neither did mechanical introduction of holes throughout the dermis. Two factors were identified that significantly enhanced endothelial cell penetration into the dermis: hypoxia and the site of endothelial cell addition. Endothelial cells added from the papillary surface entered into the dermis much more effectively than when cells were added to the reticular surface of the dermis. We conclude that this model is valuable in improving our understanding of how to enhance vascularization of tissue-engineered grafts.

Improvements on the Agar Plate Method to Determine Lysozyme

Through systematic investigation of several variables the agar plate assay for lysozyme was modified so that concentrations as low as 5μg egg white lysozyme per 100 ml of sample could be determined in 3 h. Plates were stained with 0.5g buffalo black in 100 ml 7% acetic acid followed by destaining in 7% acetic acid until satisfactory contrast between clear zones of lysis and surrounding seeded agarose was obtained. Standard egg white lysozyme solutions remained stable for at least 7 days at −5 C. The best lyso-plate method included 1.0g agarose with 0.1g NaC1 in 100 ml of a pH 7.0 phosphate buffer seeded with 0.020g Micrococcus lysodeikticus and incubation at 47 C for 3 h.

On necessary and sufficient conditions in psychiatric explanation.

IT IS WIDELY, if not universally, accepted that psychological events are multidetermined; that there are no simple, unique explanations for most such events. In Psychological research, however, the investigation of several variables at once necessitates large numbers of subjects; * and for practical reasons it is common to explore one variable at a time. Historical cross-sectional studies are common in psychological and epidemiological research. Generally they seek to determine the frequency of occurrence of some crucial event or class of events in the histories of individuals in a particular pathological population in comparison with their frequency in a normal population.† Typical examples are: (1) the incidence of psychopathology in the mothers of schizophrenics, (2) the incidence of early parental death in the histories of depressive patients, and (3) the incidence of early illness or trauma in the histories of childhood schizophrenics. The inference

An Investigation of Several Variables as Determinants of Authoritarianism

(1959). An Investigation of Several Variables as Determinants of Authoritarianism. The Journal of Social Psychology: Vol. 49, No. 1, pp. 105-111.