1,031 research outputs found
Effect of carbamyl phosphate on stability of some enzymes of the urea cycle; high sensitivity of glutamate dehydrogenase
Alzheimer’s Disease: A Thermodynamic Perspective
Alzheimer’s disease is investigated using a thermodynamic approach based on ion fluxes across the neuronal membrane. Our study indicates that the onset of Alzheimer’s may be aided by a hyperpolarization of this membrane, because hyperpolarization-activated cyclic nucleotide gated HCN channels 1–4 conduct inward, with the consequence of depolarising Na+/K+ currents which in turn impacts synaptic transmission and reduces plasticity
A non-equilibrium thermodynamic approach to symmetry breaking in cancer
This paper develops a non-equilibrium thermodynamics approach to oncogenesis, with a particular focus on ‘symmetry breaking’. The Onsager phenomenological
coefficients are introduced to show the biophysical and thermophysical properties of cellular systems with differences between normal and cancerous cells. Seebeck- and Peltier-like
effects are introduced to simplify the description of heat exchange and ion fluxes, in an effort to characterize the distinct role of the cellular electric membrane potential. Our results
indicate that oncogenesis leads to changes in: (i) the thermophysical properties of the cell cytoplasm, caused by differences in density and heat capacity, (ii) the interactions with the
micro-environment, (iii) geometrical characteristics, both in fractal dimensions and in shape symmetry, and (iv) the constitutive properties of membrane fluxes. This presents a unifying
biophysics concept for such diverse characteristics, and it may yield new diagnostic and therapeutic opportunities
THERMODYNAMICS AND SARS-COV-2: NEUROLOGICAL EFFECTS IN POST-COVID 19 SYNDROME
There is increasing evidence that infection with SARS-CoV-2 can cause a spectrum of neurological symptoms. In this paper, we develop a theoretical concept underlying such neurological COVID-19 consequences by employing a non-equilibrium thermodynamic approach that allows linking the neuronal electric potential with a virus induced
pH variation. Our theoretical findings support further experimental work on therapeutically correcting electrolyte imbalances, such as Na+ and K+, to attenuate the neurological effects of SARS-CoV-2
Entropy-Based Pandemics Forecasting
A great variety of natural phenomena follows some statistical distributions. In epidemiology, such as for the current COVID 19 outbreak, it is essential to develop reliable predictions of the evolution of an infectious disease. In particular, a statistical projection of the time of maximum diffusion of infected carriers is fundamental in order to prepare healthcare systems and organize a robust public health response. In this paper, we develop a thermodynamic approach based on the infection statistics related to the total citizenry of a country. It represents a novel tool for evaluating the time of maximum diffusion of an epidemic or pandemic
Seebeck-like effect in SARS-CoV-2 Bio-thermodynamics
The new coronavirus, SARS-CoV-2, relies on a pH decrease to infect the target cell and replicate its RNA. This leads to a change in the electric potential of the cell’s membrane which in turn alters cell functions. Therapeutic intervention should therefore assist these cells in maintaining their natural electric membrane potential so that they can manage normal fluxes of heat and ions which are essential for survival. Results from our thermodynamic approach suggest to employ anti-SARS-CoV-2 therapeutic strategies that are capable to vary the Gibbs function, related to pH-dependent viral glycoproteins. Our approach lends theoretical credence to the potential benefit of using as starting points drugs such as chloroquine and hydroxychloroquine, while not minimizing their controversial risk profile as described recently in several COVID-19 clinical studies
Temporal evolution and spatial distribution of dust creation events in Tore Supra and in ASDEX Upgrade studied by CCD image analysis
A Thermodynamic Perspective of Cancer Cells’ Volume/Area Expansion Ratio
The constructal law is used to improve the analysis of the resonant heat transfer in cancer cells. The result highlights the fundamental role of the volume/area ratio and its role in cancer growth and invasion. Cancer cells seek to increase their surface area to facilitate heat dissipation; as such, the tumour expansion ratio declines as malignant cells start to migrate and the cancer expands locally and systemically. Consequently, we deduce that effective anticancer therapy should be based on the control of some ion transport phenomena in an effort to increase the volume/area ratio. This emphasises restricting the local and systemic spatial expansion of the tumour system and thus gives further credence to the superior role of novel anti-migratory and anti-invasive treatment strategies over conventional anti-proliferative options only
Applicability of molding procedures in laboratory mix tests for quality control and assurance of the deep mixing method
The deep mixing method (DMM) has been applied in many construction projects. The laboratory mix test is essential to the quality control and quality assurance (QC/QA) of deep mixing methods. The procedures used for the preparation of specimens in the laboratory mix test greatly affect the physical and mechanical properties of the stabilized soils. Different procedures are applied in different countries/regions. With the increasingly globalized DMM market, it is desirable that a common understanding of the nature of the laboratory mix test and internationally accepted guidelines to conduct it be established in order to guarantee the QC/QA of DMMs. As part of an international collaborative study, the influence of different molding techniques for the laboratory preparation of specimens was studied. Five different molding techniques were tested in four organizations. The results showed that the molding techniques considerably influenced the magnitude and variation of the unconfined compressive strength and the wet unit weight of the stabilized specimens. The applicability of the molding techniques was discussed in terms of their undrained shear strength and the liquidity index of the soil and binder mixture, and the usefulness of the techniques was demonstrated. (C) 2015 The Japanese Geotechnical Societ
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