53 research outputs found

    The `Friction' of Vacuum, and other Fluctuation-Induced Forces

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    The static Casimir effect describes an attractive force between two conducting plates, due to quantum fluctuations of the electromagnetic (EM) field in the intervening space. {\it Thermal fluctuations} of correlated fluids (such as critical mixtures, super-fluids, liquid crystals, or electrolytes) are also modified by the boundaries, resulting in finite-size corrections at criticality, and additional forces that effect wetting and layering phenomena. Modified fluctuations of the EM field can also account for the `van der Waals' interaction between conducting spheres, and have analogs in the fluctuation--induced interactions between inclusions on a membrane. We employ a path integral formalism to study these phenomena for boundaries of arbitrary shape. This allows us to examine the many unexpected phenomena of the dynamic Casimir effect due to moving boundaries. With the inclusion of quantum fluctuations, the EM vacuum behaves essentially as a complex fluid, and modifies the motion of objects through it. In particular, from the mechanical response function of the EM vacuum, we extract a plethora of interesting results, the most notable being: (i) The effective mass of a plate depends on its shape, and becomes anisotropic. (ii) There is dissipation and damping of the motion, again dependent upon shape and direction of motion, due to emission of photons. (iii) There is a continuous spectrum of resonant cavity modes that can be excited by the motion of the (neutral) boundaries.Comment: RevTex, 2 ps figures included. The presentation is completely revised, and new sections are adde

    Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension

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    OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo

    Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab

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    The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Five insights from the Global Burden of Disease Study 2019

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    The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a rules-based synthesis of the available evidence on levels and trends in health outcomes, a diverse set of risk factors, and health system responses. GBD 2019 covered 204 countries and territories, as well as first administrative level disaggregations for 22 countries, from 1990 to 2019. Because GBD is highly standardised and comprehensive, spanning both fatal and non-fatal outcomes, and uses a mutually exclusive and collectively exhaustive list of hierarchical disease and injury causes, the study provides a powerful basis for detailed and broad insights on global health trends and emerging challenges. GBD 2019 incorporates data from 281 586 sources and provides more than 3.5 billion estimates of health outcome and health system measures of interest for global, national, and subnational policy dialogue. All GBD estimates are publicly available and adhere to the Guidelines on Accurate and Transparent Health Estimate Reporting. From this vast amount of information, five key insights that are important for health, social, and economic development strategies have been distilled. These insights are subject to the many limitations outlined in each of the component GBD capstone papers.Peer reviewe

    Effectiveness of the Cognitive behavioral therapy(CBT) in improving nutritional and weight status in overweight adolescents

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    Background and Objectives: The growing trend of obesity in childhood and adolescence is now viewed as a challenging and costly issue in the health area. One of the methods of treating obesity is cognitive behavioral therapy as a suitable weight loss treatment approach. The purpose of this study was to examine the effectiveness of cognitive behavioral therapy (CBT) on weight loss in obese and overweight adolescents. Material and Method: This study is a randomized controlled trial that was conducted on obese or overweight children and their parents. 120 Overweight and obese adolescents aged 13–18 y were selected from schools, they randomly assigned to CBT or no treatment (control). Weight, height, hip and waist circumferences, BMI was measured at beseline and 6 month later. Food intake(170 items), Weight-Efficacy of Life style(20items), quality of life(23 items), nutrition self-efficacy(15 items) and Physical activity were asked by valid questionnaires. Intervention group recieved CBT consisted of 6 weekly sessions, followed by five telephone or face to face sessions. All assessments was conducted at baseline and six month later inorder to evaluate effectiveness of this treatment method. Result: The adjustment of different confounders showed that the anthropometric variables (body mass index, waist circumference, hip circumference) decreased significantly compared to the control group ( ZBMI= 1.93 in CBT and ZBMI= 2.18 in control, P<0.05) Also, there was significant increasing in behavioral physical activity, self-efficacy lifestyle, nutritional self-efficacy, physical activity and quality of life(P<0.05). Comparison of dietary intake in the two groups showed that a significant increaseing in fruits, vegetables, cereals and meat intake, a significant decreaseing in unhealthy meals, such as salty meals, processed meat such as sausage and sausages(P<0.05 although the amount of energy intake did not change significantly. Conclusion: Six weekly cognitive behavioral therapy and a follow-up of 6 months improved body mass index and anthropometric variables. Positive behavioral changes created lifestyle, nutritional, and physical activity self-efficacy. The intervention also improved the health related quality of life. Keywords:obesity-overweight-nutritional status- Cognitive behavioral therapy- self efficacy- Quality of life- Physical activit

    Health Related Quality of Life and Weight Self-Efficacy of Life Style among Normal-Weight, Overweight and Obese Iranian Adolescents: A Case Control Study

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    Background: Identifying and investigating the factors influencing self-efficacy and eventually health related quality of life (HRQoL) can be an important step toward the prevention and treatment of the obesity. The aim of the study was to compare weight self-efficacy and HRQoL among normal-weight, overweight and obese Iranian adolescents. Materials and Methods In this case-control study, 118 obese and overweight adolescents (case group) and 118 adolescents with normal weight (control group) were recruited. Adolescent's anthropometric characteristics were measured. The Weight Efficacy Lifestyle Questionnaire (WEL), pediatric quality of life inventory (PedsQLTM 4.0) and self-reported physical activity were completed by the adolescents. Results: Multivariate logistic regression adjusting for various confounders indicated that overweight and obese adolescents were less likely to be physically active (adjusted odds ratio, AOR= 0.66; 95% confidence interval [CI], 0.48 to 0.911), had lower ability to cope with social pressure (AOR= 0.54; 95% CI, 0.32 to 0.93), involved in less positive activities (AOR= 0.53; 95% CI, 0.37 to 0.75), and felt more negative emotions (AOR= 0.23; 95% CI, 0.14 to 0.36) than their normal-weight counterparts. Moreover, obese and overweight adolescents were more likely to report deteriorated quality of life in all PedsQL subscales than those with normal weight P<0.05). The results of the mediation analysis indicated that negative emotions mediated the relationship between adolescents’ weight status and HRQoL (Z =-5.79, P<0.001). Conclusion: Weight management programs should focus on increasing adolescent’s control on situations related to negative emotions to improve their HRQoL

    Role of Postbiotics in Diet-Induced Metabolic Disorders

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    Although the prevalence of metabolic disorders has progressively increased over the past few decades, metabolic disorders can only be effectively treated with calorie restriction and improved physical activity. Recent research has focused on altering the gut microbiome using prebiotics, probiotics, and postbiotics because various metabolic syndromes are caused by gut microbial dysbiosis. Postbiotics, substances produced or released by microorganism metabolic activities, play an important role in maintaining and restoring host health. Because postbiotics have a small amount of literature on their consumption, there is a need for more experiments on short- and long-term intake. This review discusses current postbiotic research, categories of postbiotics, positive roles in metabolic syndromes, and potential therapeutic applications. It covers postbiotic pleiotropic benefits, such as anti-obesity, anti-diabetic, and anti-hypertensive qualities, that could aid in the management of metabolic disorders. Postbiotics are promising tools for developing health benefits and therapeutic goals owing to their clinical, technical, and economic properties. Postbiotic use is attractive for altering the microbiota; however, further studies are needed to determine efficacy and safety

    Synthesis, Crystal Structure, Hirshfeld Surface Analysis and Docking Studies of a Novel Flavone–Chalcone Hybrid Compound Demonstrating Anticancer Effects by Generating ROS through Glutathione Depletion

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    The flavone–chalcone hybrid compound, (E)-6-bromo-3-(3-(2-methoxyphenyl)-3-oxoprop-1-enyl)-4H-chromen-4-one (3), was synthesized and its three dimensional structure was identified by X-ray crystallography. The compound 3, C19H13BrO4, was crystallized in the triclinic space group P-1 with the following cell parameters: a = 8.2447(6) Å; b = 8.6032(6) Å; c = 11.7826(7) Å; α = 92.456(2)°; β = 91.541(2)°; γ = 106.138(2)°; V = 801.42(9) Å3 and Z = 2. In an asymmetric unit, two molecules are packed by a pi–pi stacking interaction between two flavone rings that are 3.790 Å apart from each other. In the crystal, two hydrogen bonds form inversion dimers and these dimers are extended along the a axis by another hydrogen bond. Hirshfeld analysis revealed that the H–H (34.3%), O–H (19.2%) and C–H (16.7%) intermolecular contacts are the major dominants, while the C–O (6.7%) and C–C (6.5%) are minor dominants. When HCT116 cells were treated with various concentrations of hybrid compound 3, reduced cell viability and induced apoptosis in HCT116 cells were observed in a dose-dependent manner. The treatment of HCT116 colon cancer cells with compound 3, decreased the intracellular glutathione (GSH) levels and generated a reactive oxygen species (ROS). In silico docking experiments between the compound 3 and glutathione S-transferase (GST) containing glutathione were performed to confirm whether the compound 3 binds to glutathione. Their binding energy ranged from −6.6 kcal/mol to −5.0 kcal/mol, and the sulfur of glutathione is very close to the Michael acceptor regions of the compound 3, so it is expected that they would easily react with each other. Compound 3 may be a promising novel anticancer agent by ROS generation through glutathione depletion
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