619 research outputs found

    Variation of Electrostatic Coupling and Investigation of Current Percolation Paths in Nanocrystalline Silicon Cross Transistors

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    Nanocrystalline silicon thin films are promising materials for the development of advanced Large Scale Integration compatible quantum-dot and single-electron charging devices. The films consist of nanometer-scale grains of crystalline silicon, separated by amorphous silicon or silicon dioxide grain boundaries up to a few nanometer thick. These films have been used to fabricate single-electron transistor and memory devices, where the grains form single-electron charging islands isolated by tunnel barriers formed by the grain boundaries. The grain boundary tunnel barrier isolating the grains is also of great importance, as this determines the extent of the electrostatic and tunnel coupling between different grains. These effects can lead to the nanocrystalline silicon thin film behaving as a system of coupled quantum dots.& more..

    Comparison of Subjective Responses to Oral and Intravenous Alcohol Administration under Similar Systemic Exposures

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    Objective To test whether an individual's subjective responses to alcohol are similar when the breath alcohol concentration (BrAC) trajectory resulting from oral administration is matched by intravenous administration. Background Individuals perceive the effects of alcohol differently, and the variation is commonly used in research assessing the risk for developing an alcohol use disorder. Such research is supported by both oral and intravenous alcohol administration techniques, and any differences attributable to the route employed should be understood. Methods We conducted a 2‐session, within‐subject study in 44 young adult, healthy, non‐dependent drinkers (22 females and 22 males). In the first session, subjects ingested a dose of alcohol which was individually calculated, on the basis of total body water, to yield a peak BrAC near 80 mg/dl, and the resulting BrAC trajectory was recorded. A few days later, subjects received an intravenous alcohol infusion rate profile, pre‐computed to replicate each individual's oral alcohol BrAC trajectory. In both sessions, we assessed 4 subjective responses to alcohol: SEDATION, SIMULATION, INTOXICATION, and HIGH; at baseline and frequently for 4 hours. We compared the individuals’ baseline‐corrected responses at peak BrAC and at half‐peak BrAC on both the ascending and descending limbs. We also computed and compared Pearson‐product moment correlations of responses by route of administration, the Mellanby measure of acute adaptation to alcohol, and the area under the entire response curve for each subjective response. Results No significant differences in any measure could be attributed to the route of alcohol administration. Eleven of 12 response comparisons were significantly correlated across the routes of alcohol administration, with 9 surviving correction for multiple measures, as did the Mellanby effect and area under the response curve correlations. Conclusion The route of alcohol administration has a minimal effect on subjective responses to alcohol when an individual's BrAC exposure profiles are similar

    Menstrual irregularities, hormonal imbalances and obesity in teenage and adolescent girls in Hyderabad, Sindh, Pakistan

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    Background: Obesity in young girls adversely affects reproductive health later in life and it is a serious public health issue. The objective was to study the association of obesity with menstrual irregularities and hormonal imbalance in teenage and adolescent girls. Method: Participants comprised a convenience sample of 12-19 years old girls (N=83). The study was conducted in outpatient clinics at a university hospital. Data were collected through medical history by interview, physical examination and blood tests. Data were analysed using frequencies, descriptive statistics, Chi Squared tests of Independence and Binary Logistic Regression. Results: The median age was 16 years (mean 15.9, SD 2.2) and the median BMI was 31.14 (mean 32.04, SD 4.51). Most of the girls were obese (95.2%) and some had a family history of obesity (33.7%), diabetes (28.9%) and cardiovascular disease (20.5 %). Clinical presentations included secondary amenorrhea (34.9%), heavy and irregular periods (22.9%) and oligomenorrhea (16.9%). Girls with a polycystic ovary (54.2%, n=45) had a reversed follicle stimulating hormone (FSH) / luteinizing hormone (LH) ratio (OR 11.33, 95% CI 2.98, 43.04, p < 0.001), an upper limit or raised fasting insulin (OR 7.20, 95% CI 2.33, 22.22, p < 0.001), a raised testosterone (OR=5.16, 95% CI 1.56, 17.11, p = 0.007 and a disturbed lipid profile (OR 5.67, 95% CI 1.72, 18.73, p = 0.004). Obesity was not statistically significantly associated with either polycystic ovary syndrome (PCOS) or any of the measured hormone levels. Conclusion: Adolescent girls presenting with obesity, menstrual irregularities and hormonal imbalance may suggest manifestation of PCOS, which needs early investigation and proper management

    COMPARATIVE EFFICACY OF DETOMIDINE AND DETOMIDINE - KETAMINE COCKTAIL IN QUAILS

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    Twenty adult healthy quails (Coturnix coturnix) were divided into two equal groups. One group was administered detomidine (2.4 mg/kg, I/M) and other group was administered detomidine-ketamine cocktail (1.2 mg/kg + 30 mg/kg, I/M). Detomidine slowly and smoothly induced a light sedation accompanied by superficial analgesia, hypoventilation, hypothermia and bradycardia in all birds. Detomidine-ketamine cocktail rapidly and smoothly induced a deep anaesthesia accompanied by deep analgesia, hypoventilation, hypothermia and bradycardia and complete loss of all reflexes in all birds. In both groups, recovery from sedation and anaesthesia was smooth and of short duration. From this study it was concluded that for minor and least painful procedures in quails detomidine can be used alone, while for major and painful surgical procedures detomidine-ketamine combination should be preferred

    Investigation of the Carbon Monoxide Gas Sensing Characteristics of Tin Oxide Mixed Cerium Oxide Thin Films

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    Thin films of tin oxide mixed cerium oxide were grown on unheated substrates by physical vapor deposition. The films were annealed in air at 500 °C for two hours, and were characterized using X-ray photoelectron spectroscopy, atomic force microscopy and optical spectrophotometry. X-ray photoelectron spectroscopy and atomic force microscopy results reveal that the films were highly porous and porosity of our films was found to be in the range of 11.6–21.7%. The films were investigated for the detection of carbon monoxide, and were found to be highly sensitive. We found that 430 °C was the optimum operating temperature for sensing CO gas at concentrations as low as 5 ppm. Our sensors exhibited fast response and recovery times of 26 s and 30 s, respectively

    Clinical scoring system: a valuable tool for decision making in cases of acute appendicitis

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    Objective: Decision making in cases of acute appendicitis poses a clinical challenge specially in developing countries where advanced radiological investigations do not appear cost effective and so clinical parameters remain the mainstay of diagnosis. The aim of our study was to devise a scoring system from our local database and test its accuracy in the preoperative diagnosis of acute appendicitis.Methods: Clinical data from 401 patients having undergone appendectomy were collected to identify predictive factors that distinguished those with appendicitis from those who had a negative appendectomy. Ten such factors were identified and using Bayesian probability a weight was assigned to each and the results summated to get an overall score. A cut-off point was identified to separate patients for surgery and those for observation. The scoring system was then retrospectively applied to a second population of 99 patients in order to compare suggested actions (derived from the scoring system) to those actually taken by surgeons. The sensitivity, specificity and accuracy for the level of decision was then calculated.Results: Of the 99 patients, the method suggested immediate surgery for 65 patients, 63 of whom had acute appendicitis (3.1% diagnostic error rate). Of the 33 patients in whom the score suggested active observation, 18 had appendicitis. The accuracy of our scoring system was 82%. The method had a sensitivity of 78%, specificity 89% and a positive predictive value of 97%. The negative appendectomy rate determined by our study was 7% and the perforation rate 13%.CONCLUSION: Scoring system developed from a local database can work effectively in routine practice as an adjunct to surgical decision making in questionable cases of appendicitis
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