Characterization of polybenzimidazole (PBI) film at high temperatures

Polybenzimidazole, a linear thermoplastic polymer with excellent thermal stability and strength retention over a wide range of temperatures, was evaluated for its potential use as the main dielectric in high temperature capacitors. The film was characterized in terms of its dielectric properties in a frequency range of 50 Hz to 100 kilo-Hz. These properties, which include the dielectric constant and dielectric loss, were also obtained in a temperature range from 20 C to 300 C with an electrical stress of 60 Hz, 50 V/mil present. The alternating and direct current breakdown voltages of silicone oil impregnated films as a function of temperature were also determined. The results obtained indicate that while the film remained relatively stable up to 200 C, it exhibited an increase in its dielectric properties as the temperature was raised to 300 C. It was also found that conditioning of the film by heat treatment at 60 C for six hours tended to improve its dielectric and breakdown properties. The results are discussed and conclusions made concerning the suitability of the film as a high temperature capacitor dielectric

Modelling and Analysis of the Simple Water Heater System

Modelling is nothing but converting physical information in to mathematical form. Mathematical model plays vital role for identification and analysis of the system. In this paper simple water heater system was taken as test bench. Considering system parameters mathematical model of first order with time delayed was derived. Model was simulated in the simulation tool MATLAB and systems response has been studied by changing various parameters like static gain, time constant, delay time and noise, for applied step input.Response of the simulated system was analysed and compare with the actual real time system parameters. Keywords: Modelling, Analysis, MATLAB, Water heater system.DOI:http://dx.doi.org/10.11591/ijece.v1i1.5

Prescribing quality in patients with chronic diseases at primary and secondary health care facilities using prescription quality index tool

Background: Prescribing quality is a matter of major concern worldwide. This study was carried out to determine the quality of prescribing in chronic diseases at primary health care (PHC) and secondary health care (SHC) settings using the new prescription quality index (PQI) tool.Methods: A cross-sectional observational study was carried out at four PHC and two SHC facilities in Anand district of India. Patients attending these facilities for at least 3 months were included. Complete medical history and prescriptions received were noted. Total and criteria wise PQI scores were derived for each prescription. Prescriptions were categorized as poor (score of ≤31), medium (score 32-33), and high quality (score 34-43) based on PQI total score. The internal consistency of PQI was measured using item total correlation and Cronbach’s α so as to validate it in our settings. Data were analyzed using Statistical Package for Social Science 20.Results: A total of 134 prescriptions were collected and evaluated for quality of prescribing. Mean age of patients was 60.6 ± 13.5 years. Mean PQI score was 23.60 ± 9.3 with 71.6% prescriptions being of poor quality. Quality of prescribing did not differ at PHC and SHC (P>0.05). Of 22 criteria, PQI score was strongly correlated with drug indication, drug effectiveness, evidence-based prescribing, unnecessary duplication, duration of therapy, and cost (P<0.01). PQI total score was negatively correlated to the number of drugs per prescription. Cronbach’s α for the entire 22 criteria were 0.90.Conclusion: PQI was found to be a reliable tool for assessment of prescribing quality in chronic diseases

Orthopaedic aspect of anatomy and radiology of proximal femur

Femoral pathology is common in relation to the orthopedic. There is complex anatomy of the proximal femur and hip joint. So, its knowledge regarding anatomy and radiological correlation is necessary to the well-known fact for the orthopedics for the routine day to day practice. This review article briefly illustrates important anatomical and radiological aspect of the proximal femur

High temperature dielectric properties of Apical, Kapton, Peek, Teflon AF, and Upilex polymers

Reliable lightweight systems capable of providing electrical power at the magawatt level are a requirement for future manned space exploration missions. This can be achieved by the development of high temperature insulating materials which are not only capable of surviving the hostile space environment but can contribute to reducing the mass and weight of the heat rejection system. In this work, Apical, Upilex, Kapton, Teflon AF, and Peek polymers are characterized for AC and DC dielectric breakdown in air and in silicone oil at temperatures up to 250 C. The materials are also tested in terms of their dielectric constant and dissipation factor at high temperatures with an electrical stress of 60 Hz, 200 V/mil present. The effects of thermal aging on the properties of the films are determined after 15 hours of exposure to 200 and 250 C, each. The results obtained are discussed and conclusions are made concerning the suitability of these dielectrics for use in capacitors and cable insulations in high temperature environments

Prevalence of subclinical ketosis and relationships with postpartum diseases in European dairy cows

Subclinical ketosis (SCK) is defined as concentrations of β-hydroxybutyrate (BHBA) ≥ 1.2 to 1.4 mmol/L and it is considered a gateway condition for other metabolic and infectious disorders such as metritis, mastitis, clinical ketosis, and displaced abomasum. Reported prevalence rates range from 6.9 to 43% in the first 2 mo of lactation. However, there is a dearth of information on prevalence rates considering the diversity of European dairy farms. The objectives of this study were to (1) determine prevalence of SCK, (2) identify thresholds of BHBA, and (3) study their relationships with postpartum metritis, clinical ketosis, displaced abomasum, lameness, and mastitis in European dairy farms. From May to October 2011, a convenience sample of 528 dairy herds from Croatia, Germany, Hungary, Italy, Poland, Portugal, Serbia, Slovenia, Spain, and Turkey was studied. β-Hydroxybutyrate levels were measured in 5,884 cows with a handheld meter within 2 to 15 d in milk (DIM). On average, 11 cows were enrolled per farm and relevant information (e.g., DIM, postpartum diseases, herd size) was recorded. Using receiver operator characteristic curve analyses, blood BHBA thresholds were determined for the occurrence of metritis, mastitis, clinical ketosis, displaced abomasum, and lameness. Multivariate binary logistic regression models were built for each disease, considering cow as the experimental unit and herd as a random effect. Overall prevalence of SCK (i.e., blood BHBA ≥ 1.2 mmol/L) within 10 countries was 21.8%, ranging from 11.2 to 36.6%. Cows with SCK had 1.5, 9.5, and 5.0 times greater odds of developing metritis, clinical ketosis, and displaced abomasum, respectively. Multivariate binary logistic regression models demonstrated that cows with blood BHBA levels of ≥ 1.4, ≥ 1.1 and ≥ 1.7 mmol/L during 2 to 15 DIM had 1.7, 10.5, and 6.9 times greater odds of developing metritis, clinical ketosis, and displaced abomasum, respectively, compared with cows with lower BHBA blood levels. Interestingly, a postpartum blood BHBA threshold ≥ 1.1 mmol/L increased the odds for lameness in dairy cows 1.8 (95% confidence interval: 1.3 to 2.5) times. Overall, prevalence of SCK was high between 2 to 15 DIM and SCK increased the odds of metritis, clinical ketosis, lameness, and displaced abomasum in European dairy herds

Rasmussen’s encephalitis in an Indian child

A 5 year old boy with history of recurrent seizures and progressive weakness in left upper & lower limb. On MRI scan atrophy of right cerebral hemisphere with prominent right sided sulci & sylvian fissure. Temporal horn of right lateral ventricle appears prominent. Body and genu of corpus callosum appears hypo plastic. Electroencephalography revealed moderate voltage record showing mixed activity comprising ill-defined 8-10 Hz alpha rhythm plus 4-7Hz waves and random background delta components at 3Hz frequency. A clinical diagnosis of focal tonic-clonic epilepsy was made secondary to Rasmussen’s encephalitis, based on the features MRI scan findings of the brain

Knowledge, attitudes and practices of medical researchers toward authorship in scientific journals

Background: The knowledge, attitudes and practices of scientific authorship vary across different regions. We conducted this study to understand this variation among medical researchers in India.Methods: An anonymous web-based researcher-survey invited all faculty, researchers and PhD students at Pacific institute of Medical sciences, Udaipur, India. The study design and the questionnaire were approved by the institutional ethics committee.  Basic information on study was given to obtain consent for participation. The 30 questions on authorship experience and related issues were based on the statements in International Committee of Medical Journal Editors (ICMJE) and other national and international recommendations on authorship. Participants reported their authorship experiences and answered multiple choice questionnaires.Results: The response rate was 36.36% among the participants, who were post-graduate with up to 10 years of research experience. About 62.5% had not been appropriately acknowledged as authors at some point during their career. Contributors (authorship) and ethical peer review is perceived as the key principle of research integrity. Though, single authorship was regarded as more significant, interdisciplinary management of diseases increases number of co-authors. A platform to challenge authorship, declaration of contribution in authorship and shared responsibility of co-authors in case of fraudulent publication was majority opinion.Conclusions: Almost 50 of the participant medical researchers had knowledge of formal authorship requirements. Majority agreed with the criteria would help in decreasing the authorship dispute in the medical research. There is need for awareness and continuous education on these criteria

Acoustic Immunosensing of Exosomes Using a Quartz Crystal Microbalance with Dissipation Monitoring

Exosomes are endocytic lipid-membrane bound bodies with the potential to be used as biomarkers in cancer and neurodegenerative disease. The limitations and scarcity of current exosome characterization approaches have led to a growing demand for translational techniques, capable of determining their molecular composition and physical properties in physiological fluids. Here, we investigate label-free immunosensing, using a quartz crystal microbalance with dissipation monitoring (QCM-D), to detect exosomes by exploiting their surface protein profile. Exosomes expressing the transmembrane protein CD63 were isolated by size-exclusion chromatography from cell culture media. QCM-D sensors functionalized with anti-CD63 antibodies formed a direct immunoassay toward CD63-positive exosomes in 75% v/v serum, exhibiting a limit-of-detection of 2.9 × 108 and 1.4 × 108 exosome sized particles (ESPs)/mL for frequency and dissipation response, respectively, i.e., clinically relevant concentrations. Our proof-of-concept findings support the adoption of dual-mode acoustic analysis of exosomes, leveraging both frequency and dissipation monitoring for use in bioanalytical characterization