Loss Model for Gallium Nitride DC-DC Buck Converter

In recent years, more research has been done on Enhancement Mode Gallium Nitride (eGaN) converters, as the world is moving towards more power efficient converters. Power converters play a major role in efficiently controlling and converting electric energy used by machines, systems, and everyday products. The process to make converters more efficient was complicated and slow in the twentieth century. One of the important aspects in power electronics is to evaluate different losses and minimize losses to achieve high efficiency of the converter. With help of simulation tools such as MATLAB and LTspice, this process has become much faster and reliable in the modern era. A model for estimating power losses for eGaN DC-DC buck converter (12V/1.2V) is illustrated in this paper. This loss model was calculated for different frequencies, and compared experimentally and theoretically. This paper also investigated the constant variables, which help realize the difference between theoretical and experimental losses in eGaN DC-DC buck converter. Pre-prints of this article have been previously made available [1-4]

Awareness and acceptance of contraceptive methods among post-partum patients

Background: India is the second most populous country in the world and in the next few decades it will cross china if it keeps on increasing by this exponential growth. India was the first country in the world to launch the family planning program in 1951. Despite this fact India still lags behind in practicing contraception and limiting their family size. Even though various measures for encouraging the usage of contraception have been taken up, the achievement in this field was not up to the expectation due to various social and cultural factors. The aim of our study is to (1) Estimate the prevalence of awareness for various contraceptive methods among post-partum patients and (2) To estimate the usage of contraceptive methods among post-partum patients and evaluate the various factors affecting the same.Methods: A prospective cross sectional interview based study was conducted in the department of obstetrics & gynecology, Smt. SCL general hospital, Smt. NHL municipal medical college, Ahmedabad, India. Data was collected from July 2013 to July 2015 randomly and analyzed. The women were counseled regarding post-partum contraception after assessment of their knowledge and practice. The interview included information on age, race and religion, occupation, educational status of the female as well as the husband, number of children, knowledge regarding various contraceptive methods, the source of knowledge, their attitude, the reasons for usage and non-acceptance of various contraceptive practices.Results: Total numbers of deliveries were up to 11250. Out of the total 7110 (63.2%) of the females were aware of one or more methods of contraception but the number of women practicing contraception was very low which accounted to only 1067 (15%). Acceptance of contraception was significantly associated with the female and her husband’s attitude, influence of family members, education status and socio economic status. Most of the women belonged to the age group of 22 to 25 years out of which 4725 (42%) were literate and only 788(7%) had education level above high school. Media including television and radio were the main source of contraceptive knowledge. The main reasons for non-acceptance of contraception was desire for more children especially a son due to family pressure followed by other reasons like fear of using devices, other associated myths, misconceptions and religious beliefs and customs.Conclusions: In our study the awareness of contraception accounted to 63.2% but the acceptance of contraception was only 15% and was significantly affected by the educational status of the couple and the usage of the antenatal and postnatal services available. Providing effective, high quality antenatal and post-partum contraceptive counseling can reduce not only unintended pregnancies but also induced abortions and decrease maternal morbidity and mortality as a whole. In order to improve the situations, health authorities should be encouraged to provide counseling on post-partum contraceptive methods during antenatal and immediate post-partum period on a wider scale

Development & testing of ultrasound enhanced prodrug microbubble drug delivery system

Microbubble drug delivery systems vary widely in their design and. This work focused on the application of a novel microbubble system with ultrasound-mediated delivery enhancement via consumer equipment. The work involved the creation of a novel microbubble formulation using a prodrug of Bexarotene to make the exterior layer of the microbubble. This started with development and engineering of productions schemes for stable microbubbles. Physical characterization was done to confirm production and was followed by initial in vitro testing. Results were indicative that microbubbles were formed via the protocol developed, and phantom imaging studies confirmed the enhance contrast from microbubbles for ultrasound imaging. Additionally, the in vitro tests showed enhance effectiveness in drug delivery for C32 cells through multiple assays. Demonstrating the effectiveness of using lipid type prodrugs for the creation of microbubbles and their uses for ultrasound enhanced therapy

Drug use in acute otitis media: a prospective study at a tertiary care teaching hospital

Background: Drug use study identifies the problems that arise from prescription and highlights the current approaches to the rational use of drugs. The objective of the study was to assess drug use pattern in patients diagnosed of acute otitis media in tertiary care teaching hospital.Methods: This prospective observational study was carried in the Otorhinolaryngology department of a tertiary care teaching hospital over a period of twelve months. The data collected for patients with acute otitis media included the patient's demographic details and the drugs prescribed. Data were analysed for drug use pattern and cost per prescription and assessment of rationality of prescription.Results: Total 153 patients were analysed, 100 (65.35%) belonged to male patients and 53 (34.65%) belonged to female patients. Children less than 2years age were the most diagnosed with AOM 47.71%, the major diagnostic symptoms were earache (58.16%) and fever (54.90%) and signs were congestion (52.94%) and discharge (43.13%). In a total 153 prescriptions (469 drugs), 33.68% were antimicrobials, followed by mineral supplements (23.67%). Average number of drugs per prescription was found to be 3.0. Most common antibiotic prescribed was amoxicillin (with or without clavulanate) in 142 (92.81%) patients. Paracetamol alone or in fixed dose combination with antihistaminics were prescribed in 131 patients. Average cost per prescription was 87.74(±35.67) Indian rupees. Seventeen (11.11%) prescriptions were rational in all the aspects based on standard guidelines.Conclusions: The present study showed that paracetamol and amoxicillin with or without clavulanate were mostly commonly prescribed in children with AOM. Irrational prescribing was seen in maximum number of cases

The Effect of Fluorinated Substitution of Meso Phenyl Porphyrins on Porphyrin Basicity

The purpose of this study was to determine the effects of fluorinated substitution of meso phenyl porphyrins on porphyrin basicity. The protonation of meso-Tetra(2,3,4-trifluoromethylphenyl) porphyrin (TF) and meso-Tetra(pentafluorophenyl) porphyrin (PF) will be studied through UV vis spectroscopy. Protonation is achieved by titration of each porphyrin in toluene with trifluoroacetic acid (TFA). The presence of a wavelength shift from the free base Soret to the protonated Soret will indicate the formation of a dication. The data from the UV spectra will be used to calculate the pKa values associated with each porphyrin. Based on the results, the average pKa for TF upon protonation was 2.07, while the average pKa for PF was 1.36 over four trials. A greater acidic value for PF was indicated from these results. In addition, a significant increase in the amount of acid added was noted during the protonation of PF when compared to the amount of acid needed for TF. This could indicate a correlation between the fluorinated position in the porphyrin and the formation of dication

The Effect of Fluorinated Substitution of Meso Phenyl Porphyrins on Porphyrin Basicity

The protonation of meso-Tetra(2,3,4-trifluoromethylphenyl) porphyrin (TF) and meso-Tetra(pentafluorophenyl) porphyrin (PF) will be studied through UV vis spectroscopy. Protonation is achieved by titration of each porphyrin in toluene with trifluoroacetic acid (TFA). The presence of a wavelength shift from the free base Soret to the protonated Soret will indicate the formation of a dication. The data from the UV spectra will be used to calculate the pKa values associated with each porphyrin. Based on the results, the average pKa for TF upon protonation was 2.07, while the average pKa for PF was 1.36 over four trials. A greater acidic value for PF was indicated from these results. In addition, a significant increase in the amount of acid added was noted during the protonation of PF when compared to the amount of acid needed for TF. This could indicate a correlation between the fluorinated position in the porphyrin and the formation of dication

Protonation of Methyl Phenyl Porphyrin Isomers Using UV Spectroscopy

The protonation of methyl phenyl porphyrin isomers was studied through UV vis spectroscopy using trifluoroacetic acid (TFA), a strong organic acid. Protonation was achieved by titration of the porphyrin in toluene and toluene/methanol (90:10). A wavelength shift from the free base Soret to the protonated Soret confirms the formation of the dication. The resulting UV spectra was used to calculate an apparent pKa value of each free base porphyrin isomer. Addition of methanol to the porphyrin solution decreased the average pKa values of the Soret and Q-bands for each porphyrin. This could be an indication of a stabilizing monocation, not easily seen in solution

Prevalence, pattern and perceptions of self-medication in medical students

Background: The use of self-medication is highly prevalent in the community more so amongst the medical students. Self-medication can be defined as the use of drugs to treat self-diagnosed disorders or symptoms, or the intermittent or continued use of a prescribed drug for chronic or recurrent disease or symptoms.Aims and Objectives: To study the prevalence and pattern of use of self-medication among medical students from first year to internship.Methods: This cross sectional study was carried out among under graduate medical students including interns of Smt. NHL Municipal Medical College, Ahmedabad during the period of March 2010 to May 2010. Results: Out of 747 students and interns enrolled, 685 responded (91.7%). Out of 685 respondents 564 (82.3%) reported self-medication within one year of recall period. Most common conditions/symptoms for self-medication in students were fever (72.7%), headache (69.1%), upper respiratory tract infections (64.1%) followed by others like body-ache, abdominal pain, diarrhoea etc. Over the counter drugs (84.2%) was the most common category of drugs used by all the students except first year students who used prescription only drugs more frequently (48.5%). Herbal and Ayurvedic drugs were also used as self-medication (17.8%); most frequently by the first year students (22.7%).Conclusion: The pattern of self-medication practice changes with time and advancement of knowledge