230 research outputs found
Effect of Gamma Irradiation on the Structural and Optical Properties of Bayfol CR1-4 Nuclear Track Detector
Bayfol is class of solid state nuclear track detectors (SSNTDs). Bayfol (a polycarbonate/ polyester blend) was irradiated with different doses of gamma ranging from 0 to 300 kGy. The effects of irradiation on the structural and optical properties of Bayfol were studied using X-ray diffraction (XRD) and UV spectroscopy. The XRD pattern was taken for the original (non-irradiated) sample and for samples irradiated with increasing doses of gamma irradiation. The "Intensity" and the "FWHM" were obtained; both values decrease up to a dose of 100 kGy and increase subsequently. This indicates a change in structure caused by gamma irradiation. The UV spectra of irradiated samples indicate that the absorption edge shifts towards the longer wavelengths relative to the original (non-irradiated) sample. This shows that there is a decrease in the band-gap and Urbach energy after irradiation. The refractive index decreases, with increased gamma dose, to a minimum at the 100 kGy dose and increases thereafter. Keywords: Bayfol, gamma irradiation, X-ray diffraction, UV spectr
Metabolic, Endocrine, and Immune Consequences of Sleep Deprivation
Over the last three to four decades, it has been observed that the average total hours of sleep have decreased to less than seven hours per person per night. Concomitantly, global figures relating to obesity and diabetes mellitus have increased in an alarming fashion in adults and children, and it has been hypothesized that neuro-hormonal changes accompanying this behavioral sleep deprivation may lead to insulin resistance and, subsequently, to diabetes mellitus. Sleep deprivation has been associated with multiple physiological changes, including increased cortisol and ghrelin levels, decreased leptin levels and impaired glucose metabolism. Experimental studies have also shown an increase in inflammatory and pro-inflammatory markers, which are indicators of body stress, under sleep deprivation. This review elaborates further on this hypothesis, exploring the molecular basis for the link between both entities and the underlying pathophysiology that results in insulin resistance and diabetes mellitus. We review the results of experimental and epidemiological studies, specifically examining the relationship between sleep duration and the immune and endocrine systems
Melatonin and Human Cardiovascular Disease
The possible therapeutic role of melatonin in the pathophysiology of coronary artery disorder (CAD) is increasingly being recognized. In humans, exogenous melatonin has been shown to decrease nocturnal hypertension, improve systolic and diastolic blood pressure, reduce the pulsatility index in the internal carotid artery, decrease platelet aggregation, and reduce serum catecholamine levels. Low circulating levels of melatonin are reported in individuals with CAD, arterial hypertension, and congestive heart failure. This review assesses current literature on the cardiovascular effects of melatonin in humans. It can be concluded that melatonin deserves to be considered in clinical trials evaluating novel therapeutic interventions for cardiovascular disorders.Fil: Pandi Perumal, Seithikurippu R.. King Saud University; Arabia SauditaFil: BaHammam, Ahmed S.. King Saud University; Arabia SauditaFil: Ojike, Nwakile I.. King Saud University; Arabia SauditaFil: Akinseye, Oluwaseun A.. University of New York; Estados UnidosFil: Kendzerska, Tetyana. Sunnybrook Health Sciences Center; CanadáFil: Buttoo, Kenneth. Sleep Disorders Center; CanadáFil: Dhandapany, Perundurai S.. Oregon Health And Science University; Estados UnidosFil: Brown, Gregory M.. University of Toronto; CanadáFil: Cardinali, Daniel Pedro. Pontificia Universidad Católica Argentina ; Argentin
Restless leg syndrome in multiple sclerosis: a case–control study
ObjectivesThis study assessed the prevalence of restless leg syndrome (RLS) among patients with multiple sclerosis (pwMS) and the association between RLS and MS disease duration, sleep disturbance, and daytime fatigue.MethodsIn this cross-sectional study, we interviewed 123 patients via phone calls using preset questionnaires containing the International Restless Legs Syndrome Study Group (IRLSSG) diagnostic criteria, Pittsburgh Sleep Quality Index (PSQI), and Fatigue Severity Scale (FSS) diagnostic criteria validated in both Arabic and English. The prevalence of RLS in MS was compared to a group of healthy controls.ResultsThe prevalence of RLS in pwMS, defined by meeting all four requirements included in the IRLSSG diagnostic criteria, was 30.3% compared to 8.3% in the control group. About 27.3% had mild RLS, 36.4% presented with moderate, and the remaining had severe or very severe symptoms. Patients with MS who experience RLS had a 2.8 times higher risk of fatigue compared to pwMS without RLS. pwMS with RLS had worse sleep quality, with a mean difference of 0.64 in the global PSQI score. Sleep disturbance and latency had the most significant impact on sleep quality.ConclusionThe prevalence of RLS among MS patients was significantly higher compared to the control group. We recommend educating neurologists and general physicians to increase their awareness of the increasing prevalence of RLS and its association with fatigue and sleep disturbance in patients with MS
Per3 length polymorphism in patients with type 2 diabetes mellitus
BACKGROUND: A number of observations support the involvement of circadian clock genes in the regulation of metabolic processes. One of these circadian genes, Per3, exhibits a variable number tandem repeat length polymorphism, consisting of two alleles, namely four and five repeat alleles, in its exon 18. The objective of this study was to examine the existence of Per3 variants in patients with type 2 diabetes mellitus (T2DM) as compared to a non T2DM control group. METHODS: Intravenous blood samples were collected to obtain white blood cells from 302 T2DM patients and 330 non-diabetic, age- and sex-matched, individuals. Per3 genotyping was performed on DNA by polymerase chain reaction. RESULTS: Frequency of five repeat allele was higher, and that of four repeat allele lower, in T2DM patients as compared to non-diabetic controls (χ2=6.977, p=0.0082) CONCLUSIONS: The results indicate an association of Per3 five repeat allele with T2DM occurrence and suggest that individuals with five repeat allele may be at a greater risk for T2DM as compared to those carrying the four repeat allele.Fil: Karthikeyan, Ramanujam. Madurai Kamaraj University. School of Biological Sciences. Department of Animal Behaviour and Physiology; IndiaFil: Marimuthu, Ganapathy. Madurai Kamaraj University. School of Biological Sciences. Department of Animal Behaviour and Physiology; IndiaFil: Sooriyakumar, Murugesan. Madurai Medical College. Department of Medicine; IndiaFil: BaHammam, Ahmed S.. King Saud University. College of Medicine; Arabia SauditaFil: Spence, David Warren.Fil: Pandi Perumal, Seithikurippu R.. Somnogen Canada; CanadáFil: Brown, Gregory M.. University of Toronto; CanadáFil: Cardinali, Daniel Pedro. Pontificia Universidad CatĂłlica Argentina "Santa MarĂa de los Buenos Aires". Facultad de Ciencias MĂ©dicas; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
Validation of the Pittsburgh sleep quality index in community dwelling Ethiopian adults
Examination of sleep in relation to dietary and lifestyle behaviors during Ramadan: A multi-national study using structural equation modeling among 24,500 adults amid COVID-19
Background Of around 2 billion Muslims worldwide, approximately 1.5 billion observe Ramadan fasting (RF) month. Those that observe RF have diverse cultural, ethnic, social, and economic backgrounds and are distributed over a wide geographical area. Sleep is known to be significantly altered during the month of Ramadan, which has a profound impact on human health. Moreover, sleep is closely connected to dietary and lifestyle behaviors. Methods This cross-sectional study collected data using a structured, self-administered electronic questionnaire that was translated into 13 languages and disseminated to Muslim populations across 27 countries. The questionnaire assessed dietary and lifestyle factors as independent variables, and three sleep parameters (quality, duration, and disturbance) as dependent variables. We performed structural equation modeling (SEM) to examine how dietary and lifestyle factors affected these sleep parameters. Results In total, 24,541 adults were enrolled in this study. SEM analysis revealed that during RF, optimum sleep duration (7–9 h) was significantly associated with sufficient physical activity (PA) and consuming plant-based proteins. In addition, smoking was significantly associated with greater sleep disturbance and lower sleep quality. Participants that consumed vegetables, fruits, dates, and plant-based proteins reported better sleep quality. Infrequent consumption of delivered food and infrequent screen time were also associated with better sleep quality. Conflicting results were found regarding the impact of dining at home versus dining out on the three sleep parameters. Conclusion Increasing the intake of fruits, vegetables, and plant-based proteins are important factors that could help improve healthy sleep for those observing RF. In addition, regular PA and avoiding smoking may contribute to improving sleep during RF
Attitudes towards treatment among patients suffering from sleep disorders. A Latin American survey
BACKGROUND: Although sleep disorders are common, they frequently remain unnoticed by the general practitioner. Few data are available about the willingness and reasons of patients with sleep disturbances to seek for medical assistance. METHODS: The results of a cross-sectional community-based multinational survey in three major Latin American urban areas, i.e. Buenos Aires, Mexico City and Sao Paulo, are reported. Two-hundred subjects suffering sleep disturbances and 100 non-sufferers were selected from the general population in each city (total number: 600 sufferers vs. 300 non-sufferers). A structured interview was conducted, sleep characteristics, feelings about sleep disturbances and strategies to cope with those problems being recorded. Data were analyzed by employing either t-test or analysis of variance (ANOVA) to the Z-transformed proportions. RESULTS: 22.7 ± 3.5 % (mean ± SEM) of subjects reported to suffer from sleep disturbances every night. About 3 out of 4 (74.2 ± 2.0 %) considered their disorder as mild and were not very concerned about it. Only 31 ± 2 % of sufferers reported to have sought for medical help. Although 45 ± 2 % of sufferers reported frequent daily sleepiness, trouble to remember things, irritability and headaches, they did not seek for medical assistance. Among those patients who saw a physician with complaints different from sleep difficulties only 1 out of 3 (33 ± 2 % of patients) were asked about quality of their sleep by the incumbent practitioner. Strategies of patients to cope with sleep problems included specific behaviors (taking a warm bath, reading or watching TV) (44 ± 1.6 %), taking herbal beverages (17 ± 1.2 %) or taking sleeping pills (10 ± 1.1 %). Benzodiazepines were consumed by 3 ± 0.6 % of sufferers. CONCLUSION: Public educational campaigns on the consequences of sleep disorders and an adequate training of physicians in sleep medicine are needed to educate both the public and the general practitioners about sleep disorders
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