Metabolic changes in chronic fatigue syndrome

Metabolic functions are one of the principal determinants of energy expenditure and are exquisitely susceptible to the effects of circulating hormones and chemical changes. Consequently, clinical experiments based on energy expenditure and metabolic functions were considered to be valid approaches to the present research. Significant abnormalities were found in the proton magnetic resonance spectroscopy of basal ganglia in CFS patients. Automatic cardiovascular responses to exercise are also impaired in a subset of CFS patients. Finally, plasma membrane injury appears to be a possible explanation for a range of observations made in this research. Subjective fatigue is a complex symptom. It is the outcome of a variable combination of physiological and neuropsychological changes induced by the primary disease process. Downstream links between brain, neuromuscular and the cardiorespiratory functions are implicated in the neural control of force output during exercises in health and disease. Higher perceived fatigue in CFS is probably caused by the central mechanisms while the sensory input to these neural regulatory mechanisms may limit endurance to maximal and submaximal exercises. Based on these findings and more indirect evidence from other studies, changes in cell membrane properties affecting neuronal signalling in the basal ganglia seem to emerge as one of the likely pathophysiological mechanisms in CFS. There is also evidence of an imbalance of the central autonomic tone in a subset of CFS patients. Surely, research in CFS has the potential to unravel the biology of central fatigue and may bridge the gap that exists between the borderland of neurology and psychiatry

Exploring the role of electronic structure on photo-catalytic behavior of carbon-nitride polymorphs

A fully self-consistent density-functional theory (DFT) with improved functionals is used to provide a comprehensive account of structural, electronic, and optical properties of C$_{3}$N$_{4}$ polymorphs. Using our recently developed van Leeuwen-Baerends (vLB) corrected local-density approximation (LDA), we implemented LDA+vLB within full-potential N$^{th}$-order muffin-tin orbital (FP-NMTO) method and show that it improves structural properties and band gaps compared to semi-local functionals (LDA/GGA). We demonstrate that the LDA+vLB predicts band-structure and work-function for well-studied 2D-graphene and bulk-Si in very good agreement with experiments, and more exact hybrid functional (HSE) calculations as implemented in the Quantum-Espresso (QE) package. The structural and electronic-structure (band gap) properties of C$_{3}$N$_{4}$ polymorphs calculated using FP-NMTO-LDA+vLB is compared with more sophisticated hybrid-functional calculations. We also perform detailed investigation of photocatalytic behavior using QE-HSE method of C$_{3}$N$_{4}$ polymorphs through work-function, band (valence and conduction) position with respect to water reduction and oxidation potential. Our results show $\gamma$-C$_{3}$N$_{4}$ as the best candidate for photocatalysis among all the C$_{3}$N$_{4}$~polymorphs but it is dynamically unstable at `zero' pressure. We show that $\gamma$-C$_{3}$N$_{4}$ can be stabilized under hydrostatic-pressure, which improves its photocatalytic behavior relative to water reduction and oxidation potentials.Comment: 13 pages, 12 figures, 3 table

Numerical study on the hydrate rich sediment behaviour during depressurization

Exploratory studies have been carried out to identify the potential natural gas hydrate reserves for commercially producing gas. While extracting the gas from the hydrate-bearing sediments using various dissociation techniques, there will be a significant loss of strength in these sediments. It is well known that the behavior of gas hydrate sediments is governed by Thermo Hydro Mechanical Chemical ­ THMC coupled process during the gas extraction. Thus, in this study, in order to understand the influence of depressurization at the well-bore and the permeability of the hydrate reservoir on the sediment deformation characteristics, a 2D (plane strain condition) hydrate reservoir is simulated (using a multiphase numerical schema). From the study, it is observed that the flow response, i.e., the rate of change of gas pressure near the well-bore, decreases with the increase in the duration of the extraction. The maximum settlement occurs for reservoirs having low well-bore pressure (higher amount of depressurization) and high intrinsic permeability. Additionally, these same reservoir conditions also lead to maximum cumulative gas production. Thus, the continuous gas extraction results in a highly porous medium that is stabilized primarily due to the geomechanical changes

The systematic development of a mobile phone–delivered brief intervention for hazardous drinking in India

Background: The treatment gap for alcohol use disorders (AUD) in India is the highest among all mental health and substance use disorders. Despite evidence of the cost effectiveness of brief interventions (BIs) for hazardous drinking, implementation in low- and middle-income countries (LMICs) is rare due to several human resource–related barriers. This paper describes the processes and outputs of a study aimed at systematically developing a mobile phone–delivered BI to overcome such barriers. Methods: This is a mixed methods study with four steps: (1) Review of existing relevant evidence base by extracting data from studies cited in two recent, relevant and high-quality systematic reviews; (2) In-depth interviews (IDIs) with 11 national experts in addictions research and practice, and 22 hazardous drinkers; (3) Delphi survey (2 rounds) to identify components for the intervention package through consensus building; and (4) Content and intervention development workshops with a range of stakeholders to develop the intervention package. Results: The research team sourced 72 journal articles from two selected systematic reviews. Key content areas extracted from the studies included facts and statistics about health related to drinking behavior, self-reflection, goal-setting messages, motivational messages, and skills to manage risky situations. The IDIs with experts and hazardous drinkers endorsed most of these content areas as well. The Delphi survey achieved consensus on 19 content areas, which included targeted recommendations, personalized feedback and information, goal management, and coping skills. The content and intervention development workshops resulted in an intervention package delivered over 8 weeks, with the following seven themes guiding the content of the weekly messages: safe drinking/health education, alcohol reduction, drinking and risk management, drinking alternatives, situational content, urge management, and maintenance and relapse prevention. Conclusion: The research team designed this study to consider contextual factors while developing the intervention, which is important to ensure acceptability and feasibility of the intervention. Interestingly, the contextually informed intervention components had several commonalities with BIs developed and tested in high-income countries.</p

Simple correction to bandgap problems in IV and III–V semiconductors: an improved, local first-principles density functional theory

We report results from a fast, efficient, and first-principles full-potential Nth-order muffin-tin orbital (FP-NMTO) method combined with van Leeuwen–Baerends correction to local density exchange-correlation potential. We show that more complete and compact basis set is critical in improving the electronic and structural properties. We exemplify the self-consistent FP-NMTO calculations on group IV and III–V semiconductors. Notably, predicted bandgaps, lattice constants, and bulk moduli are in good agreement with experiments (e.g. we find for Ge 0.86 eV, 5.57 , 75 GPa versus measured 0.74 eV, 5.66 , 77.2 GPa). We also showcase its application to the electronic properties of 2-dimensional h-BN and h-SiC, again finding good agreement with experiments