Energy and momentum of general spherically symmetric frames on the regularizing teleparallelism

In the context of the covariant teleparallel framework, we use the 2-form translational momentum to compute the total energy of two general spherically symmetric frames. The first one is characterized by an arbitrary function H（r）, which preserves the spherical symmetry and reproduces all the previous solutions, while the other one is characterized by a parameter ξ which ensures the vanishing of the axial of trace of the torsion. We calculate the total energy by using two procedures, i.e., when the WeitzenbSck connection Гα^β is trivial, and show how H（r） and ξ play the role of an inertia that leads the total energy to be unphysical. Therefore, we take into account Гα^β and show that although the spacetimes we use contain an arbitrary function and one parameter, they have no effect on the form of the total energy and momentum as it should be.

Energy,momentum and angular momentum in the dyadosphere of a charged spacetime in teleparallel equivalent of general relativity

We apply the energy momentum and angular momentum tensor to a tetrad field, with two unknown functions of radial coordinate, in the framework of a teleparallel equivalent of general relativity （TEGR）. The definition of the gravitational energy is used to investigate the energy within the external event horizon of the dyadosphere region for the Reissner-NordstrSm black hole. We also calculate the spatial momentum and angular momentum.

Gravitational radiation fields in teleparallel equivalent of general relativity and their energies

We derive two new retarded solutions in the teleparallel theory equivalent to general relativity （TEGR）. One of these solutions gives a divergent energy. Therefore, we use the regularized expression of the gravitational energymomentum tensor, which is a coordinate dependent. A detailed analysis of the loss of the mass of Bondi space-time is carried out using the flux of the gravitational energy-momentum.

Brane world black holes in teleparallel theory equivalent to general relativity and their Killing vectors,energy,momentum and angular momentum

The energy--momentum tensor, which is coordinate-independent, is used to calculate energy, momentum and angular momentum of two different tetrad fields. Although, the two tetrad fields reproduce the same space--time their energies are different. Therefore, a regularized expression of the gravitational energy--momentum tensor of the teleparallel equivalent of general relativity （TEGR）, is used to make the energies of the two tetrad fields equal. The definition of the gravitational energy--momentum is used to investigate the energy within the external event horizon. The components of angular momentum associated with these space--times are calculated. In spite of using a static space--time, we get a non-zero component of angular momentum! Therefore, we derive the Killing vectors associated with these space--times using the definition of the Lie derivative of a second rank tensor in the framework of the TEGR to make the picture more clear.

Bianchi type I in f(T) gravitational theories

A tetrad field that is homogeneous and anisotropic which contains two unknown functions A（t） and B（t） of cosmic time is applied to the field equations of f（T）, where T is the torsion scalar, T = T~μ_（νρ）S_μ^（νρ）. We calculate the equation of continuity and rewrite it as a product of two brackets, the first is a function of f（T） and the second is a function of the two unknowns A（t） and B（t）. We use two different relations between the two unknown functions A（t） and B（t） in the second bracket to solve it. Both of these relations give constant scalar torsion and solutions coincide with the de Sitter one. So,another assumption related to the contents of the matter fields is postulated. This assumption enables us to drive a solution with a non-constant value of the scalar torsion and a form of f（T） which represents ΛCDM.

Accuracy of Orthodontic 3D Printed Retainers versus Thermoformed Retainers

Background: The integration of the current technology of CBCT and 3D CAD/CAM technology has great potential in the field of orthodontics, which is not yet fully investigated. The purpose of this article is to evaluate the accuracy of 3D printed retainers in comparison to vacuum formed retainers. Methods: Alginate impressions were taken for ten patients who have a CBCT scan. A 3D printed retainer and vacuum formed retainer were fabricated. Linear measure-ments were measured by two assessors using digital caliper. Every measure-ment on the 3D printed retainer was compared to the corresponding measure-ment on the thermoformed retainer. The linear measurements were Inter-canine width, Inter-premolar width (first and second premolars), Inter-molar width, Canine-midline length (both sides) and Canine-molar length (both sides). Intra-observer, and inter-observer reliability measurements were done. Results: Results showed excellent intra-observer reliability for the thermoformed retainer and the 3D printed retainer. Inter-observer measurements showed strong agreement between the measurements of the two assessors, for both retainers. The comparison of the thermoformed retainer to the 3D printed retainer showed high statistical agreement, except for the canine-molar on the right side, but with no clinical significance, p value of 0.038 and mean difference 0.19. Conclusions: The new method for fabricating a 3D printed retainer is accurate and reliable in comparison to the vacuum formed retainer (conventional method). CBCT proved to be efficient for fabrication of a custom made appliances.

Electric Vehicles Lithium-Polymer Ion Battery Dynamic Behaviour Charging Identification and Modelling Scheme

Lithium-ion batteries are considered the substantial electrical storage element for electric vehicles(EVs). The battery model is the basis of battery monitoring, efficient charging, and safety management. Non-linearmodelling is the key to representing the battery and its dynamic internal parameters and performance. This paperproposes a smart scheme to model the lithium-polymer ion battery while monitoring its present charging currentand terminal voltage at various ambient conditions (temperature and relative humidity). Firstly, the suggestedframework investigated the impact of temperature and relative humidity on the charging process using the constantcurrent-constant voltage (CC-CV) charging protocol. This will be followed by monitoring the battery at thesurrounding operating temperature and relative humidity. Hence, efficient non-linear modelling of the EV batterydynamic behaviour using the Hammerstein-Wiener (H-W) model is implemented. The H-W model is considered ablack box model that can represent the battery without any mathematical equivalent circuit model which reducesthe computation complexity. Finally, the model beholds the boundaries of the charging process, not affecting onthe lifetime of the battery. Several dynamic models are applied and tested experimentally to ensure theeffectiveness of the proposed scheme under various ambient conditions where the temperature is fixed at40°C and the relative humidity (RH) at 35%, 52%, and 70%. The best fit using the H-W model reached 91.83% todescribe the dynamic behaviour of the battery with a maximum percentage of error 0.1 V which is in goodagreement with the literature survey. Besides, the model has been scaled up to represent a real EV and expressedthe significance of the proposed H-W model.

Hydroxysafflor yellow A protects against thioacetamide-induced liver fibrosis in rats via suppressing proinflammatory/fibrogenic mediators and promoting hepatic stellate cell senescence and apoptosis

Objective:To evaluate the effect of hydroxysafflor yellow A(HSYA)on thioacetamide-induced liver fibrosis.Methods:Thioacetamide was administered to rats intraperitoneally in doses of 200 mg/kg twice a week for 12 weeks.Thioacetamide-intoxicated rats were given silymarin(50 mg/kg)or HSYA(5 mg/kg)orally every day for 8 weeks.Liver enzymes,fibrosis markers,histological changes as well as immunohistochemistry of TNF-α,IL-6,p21,α-SMA,and caspase-3 were examined.The effect of HSYA on HSC-T6 activation/proliferation and apoptosis was also determined in vitro.Results:HSYA decreased liver enzymes,TNF-α,IL-6,and p21 expressions,hepatic PDGF-B,TIMP-1,TGF-β1,and hydroxyproline levels,as well as fibrosis score(S2 vs.S4)compared to the thioacetamide group.HSYA also downregulatedα-SMA while increasing caspase-3 expression.Surprisingly,at 500μg/mL,HSYA had only a slightly suppressive effect on HSC proliferation,with a 9.5%reduction.However,it significantly reduced TGF-β1,inhibitedα-SMA expression,induced caspase-3 expression,and promoted cell senescence.Conclusions:HSYA may be a potential therapeutic agent for delaying and reversing the progression of liver fibrosis.More research on HSYA at higher doses and for a longer period is warranted.

Cylindrically Symmetric Solution in Teleparallel Theory

The field equations of a special class of teleparallel theory of gravitation and electromagnetic fields are applied to tetrad space having cylindrical symmetry with four unknown functions of radial coordinate r and azimuth angle θ. The vacuum stress-energy momentum tensor with one assumption concerning its specific form generates one non-trivial exact analytic solution. This solution is characterized by a constant magnetic field parameter B0. If B0 = 0, then the solution will reduce to the flat spacetime. The energy content is calculated using the superpotential given by MФller in the framework of teleparallel geometry. The energy contained in a sphere is found to be different from the pervious results.

Repositioning of dipeptidyl peptidase-4 inhibitors and glucagon like peptide-1 agonists as potential neuroprotective agents

Repositioning of dipeptidyl peptidase-4 inhibitors and glucagon like peptide-1 receptor agonists is a breakthrough in the field of neural regeneration research increasing glucagon like peptide-1 bioavailability, hence its neuroprotective activities. In this article, the authors suggest not only crossing blood-brain barrier and neurodegenerative disease as off target for dipeptidyl peptidase-4 inhibitors and glucagon like peptide-1 receptor agonists, but also for ophthalmic preparations for diabetic retinopathy, which may be the latest breakthrough in the field if prepared and used in an appropriate nano-formulation to target the retinal nerves. The relation of neurodegenerative diseases' different mechanisms to the dipeptidyl peptidase-4 inhibitors and glucagon like peptide-1 receptor agonists should be further examined in preclinical and clinical settings. The repositioning of already marketed antidiabetic drugs for neurodegenerative diseases should save the high cost of the time-consuming normal drug development process. Drug repositioning is a hot topic as an alternative to molecular target based drug discovery or therapeutic switching. It is a relatively inexpensive pathway due to availability of previous pharmacological and safety data. The glucagon like peptide-1 produced in brain has been linked to enhanced learning and memory functions as a physiologic regulator in central nervous system by restoring insulin signaling. Intranasal administration of all marketed gliptins(or glucagon like peptide-1 receptor agonists) may show enhanced blood-brain barrier crossing and increased glucagon like peptide-1 levels in the brain after direct crossing of the drug for the olfactory region, targeting the cerebrospinal fluid. Further blood-brain barrier crossing tests may extend dipeptidyl peptidase-4 inhibitors' effects beyond the anti-hyperglycemic control to intranasal spray, intranasal powder, or drops targeting the blood-brain barrier and neurodegenerative diseases with the most suitable formula. Moreover, novel nano-formulation is encouraged either to obtain favorable pharmacokinetic parameters or to achieve promising blood-brain barrier penetration directly through the olfactory region. Many surfactants should be investigated either as a solubilizing agent for hydrophobic drugs or as penetration enhancers. Different formulae based on in vitro and in vivo characterizations, working on sister gliptins(or glucagon like peptide-1 receptor agonists), different routes of administration, pharmacokinetic studies, dose response relationship studies, monitoring of plasma/brain concentration ratio after single and multiple dose, and neurodegenerative disease animal models are required to prove the new method of use(utility) for dipeptidyl peptidase-4 inhibitors as potential neuroprotective agents. Furthermore, investigations of glucagon like peptide-1 receptor agonists' neuroprotective effects on animal models will be considered carefully because they crossed the blood-brain barrier in previous studies, enabling their direct action on the central nervous system. Combination therapy of dipeptidyl peptidase-4 inhibitors or glucagon like peptide-1 receptor agonists with already marketed drugs for neurodegenerative disease should be considered, especially regarding the novel intranasal route of administration.

Anomalous reactivity of thermo-bioconvective nanofluid towards oxytactic microorganisms

The peristaltic flow of a non-Newtonian nanofluid with swimming oxytactic microorganisms through a space between two infinite coaxial conduits is investigated. A variable magnetic field is applied on the flow. The bioconvection flow and heat transfer in the porous annulus are formulated, and appropriate transformations are used, leading to the non-dimensionalized ruling partial differential equation model. The model is then solved by using the homotopy perturbation scheme. The effects of the germane parameters on the velocity profile, temperature distribution, concentration distribution, motile microorganism profile, oxytactic profile, pressure rise, and outer and inner tube friction forces for the blood clot and endoscopic effects are analyzed and presented graphically.It is noticed that the pressure rise and friction forces attain smaller values for the endoscopic model than for the blood clot model. The present analysis is believed to aid applications constituting hemodynamic structures playing indispensable roles inside the human body since some blood clotting disorders, e.g., haemophilia, occur when some blood constituents on the artery wall get confined away from the wall joining the circulation system.

Natural antibacterial remedy for respiratory tract infections

Objective: To evaluate the antibacterial activity of Egyptian honey against bacteria causing respiratory tract infections.Methods: Sputum and throat swab specimens were used, from which five bacterial species were isolated, namely, Klebsiella pneumonia, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Streptococcus pneumonia were isolated,identified and grown on suitable media for further identification or confirmation. Different concentrations(100%, 75% and 25%) of honey and simulated honey solution were used for activity assay and estimation of minimum inhibitory concentration and minimum bactericidal concentration.Results: All the tested bacterial isolates were completely susceptible to the 75%concentrations of honey and to the 100% concentration of the simulated honey solution. This may be due to the high osmotic pressure exerted by the high sugar content in both honey samples. Moderate susceptibility of the isolated bacteria to honey at 100%v/v concentration, and resistance to honey at 25% concentration and the 75% and 25%concentrations of simulated honey solution, indicated the presence of other antimicrobial components responsible for the activity other than the osmotic pressure.Therefore, it was suggested that honey showed distinguished antibacterial activities against the most common bacteria causing respiratory infections with varied sensitivity.Conclusions: Honey, a non-toxic, nutritious, safe for human consumption and cheap natural antibacterial agent, should be globalized.

Simultaneous effects of magnetic field and space porosity on compressible Maxwell fluid transport induced by a surface acoustic wave in a microchannel

Peristaltic motion induced by a surface acoustic wave of a viscous, compressible and electrically conducting Maxwell fluid in a confined parallel-plane microchannel through a porous medium is investigated in the presence of a constant magnetic field. The slip velocity is considered and the problem is discussed only for the free pumping case. A perturbation technique is employed to analyze the problem in terms of a small amplitude ratio. The phenomenon of a “backward flow” is found to exist in the center and at the boundaries of the channel. In the second order approximation, the net axial velocity is calculated for various values of the fluid parameters. Finally, the effects of the parameters of interest on the mean axial velocity, the reversal flow, and the perturbation function are discussed and shown graphically. We find that in the non-Newtonian regime, there is a possibility of a fluid flow in the direction opposite to the propagation of the traveling wave. This work is the most general model of peristalsis created to date with wide-ranging applications in biological, geophysical and industrial fluid dynamics.

Interaction between compressibility and particulate suspension on peristaltically driven flow in planar channel

The peristaltic pumping of a viscous compressible liquid mixed with rigid spherical particles of the same size in a channel is theoretically investigated. The momentum equations for the compressible flow are solved with a perturbation analysis. The analysis is carried out by duly accounting for the nonlinear convective acceleration terms for the fluid part on the wavy wall. The zeroth-order terms yield the Poiseuille flow, and the first-order terms give the Orr-Sommerfeld equation. The explicit expression for the net axial velocity is derived. The effects of the embedded parameters on the axial fluid velocity are studied through different engineering applications. The features of the flow characteristics are analyzed and discussed in detail. The obtained results are evaluated for various parameters associated with the blood flow in the blood vessels with diameters less than 5 500 μm, whereas the particle diameter has been taken to be 8 μm. This study provides a scope to evaluate the effect of the theory of two-phase flow characteristics with compressible fluid problems, and is helpful for understanding the role of engineering applications of pumping solid-fluid mixture by peristaltically driven motion.

Preparation of Hydrogel Based on Acryl Amide and Investigation of Different Factors Affecting Rate and Amount of Absorbed Water

Hydrogel is considered as an important material in our world nowadays as it is used in many important and significant applications such as in tissue engineering and agriculture. There are hundreds of types of such materials, where most of them can be easily prepared. The main objective of this work is to prepare one of the hydrogel types which could be very useful in the agriculture of deserts where plants in dry places require water in order to grow up. There are many places around the world where raining occurs only once or twice a year. There are also places where it does not rain at all. Therefore, hydrogels are required in order to absorb water in large quantities either during raining or irrigation instead of escaping to underground and then eject them to the roots of plants over time as the plants require watering. In this research a hydrogel based on acryl amide, Poly 2-Acrylamide-2-Methyl-1-Propane Sulphonic Acid, (PAMPS) was prepared by using different percentages of a suitable cross-linking agent, Methylene-bis-Acrylamide. The cross-linker content is very important factor affects the rate and amount of absorbed water. The highest amount of absorbed water at 25°C was observed by using 0.6% cross-linking agent based on monomer mass. The temperature of absorbed water and its pH value are also essential factors that affect the rate and the amount of absorbed water and were investigated in this work. The highest amount of absorbed water was recorded at pH = 12 and at 60°C. The amount and the rate of water absorbed by Sodium Polyacrylate Hydrogel were also investigated at 25°C. The agriculture applications of hydrogel based on Sodium Polyacrylate were examined using Fenugreek seeds implanting.

Erratum to“Simultaneous effects of magnetic field and space porosity on compressible Maxwell fluid transport induced by a surface acoustic wave in a microchannel”

We would like to acknowledge the misprinted terms in our published paper“Simultaneous effects of magnetic field and space porosity on compressible Maxwell fluid transport induced by a surface acoustic wave in a microchannel”[Chin.Phys.B 22124702(2013)].Since only two misprints exist and the main results of the published paper are correct,we present the correct equations in this erratum.

Concircular π-Vector Fields and Special Finsler Spaces

The aim of the present paper is to investigate intrinsically the notion of a concircular π-vector field in Finsler geometry. This generalizes the concept of a concircular vector field in Riemannian geometry and the concept of concurrent vector field in Finsler geometry. Some properties of concircular π-vector fields are obtained. Different types of recurrence are discussed. The effect of the existence of a concircular π-vector field on some important special Finsler spaces is investigated. Almost all results obtained in this work are formulated in a coordinate-free form.

Investigation of SARS-CoV-2 Main Protease Potential Inhibitory Activities of Some Natural Antiviral Compounds Via Molecular Docking and Dynamics Approaches

Coronaviruses caused an outbreak pandemic disease characterized by a severe acute respiratory distress syndrome leading to the infection of more than 200 million patients and the death of more than 4 million individuals.The primary treatment is either supportive or symptomatic.Natural products have an important role in the development of various drugs.Thus,screening of natural compounds with reported antiviral activities can lead to the discovery of potential inhibitory entities against coronaviruses.In the current study,an in-silico molecular docking experiment was conducted on the effects of some of these natural antiviral phytoconstituents,(e.g.,procyanidin B2,theaflavin,quercetin,ellagic acid,caffeoylquinic acid derivatives,berginin,eudesm-1β,6α,11-triol and arbutin),on the crystal structure of SARS-CoV-2 main protease(PDB ID:6w63)using AutoDock-Vina software.Many of the docked compounds revealed good binding affinity,with procyanidin B2(–8.6 Kcal/mol)and theaflavin(–8.5 Kcal/mol)showing a better or similar binding score as the ligand(–8.5 Kcal/mol).Molecular dynamics simulations were carried out at 100 ns and revealed that procyanidin B2 forms a more stable complex with SARS-CoV-2 main protease than theaflavin.Procyanidin B2,theaflavin,and 4,5-dicaffeoylquinic acid were evaluated for toxicity by ProTox-II webserver and were non-toxic according to the predicted LD50 values and safe on different organs and pathways.Additionally,these phytoconstituents showed good ADME properties and acceptable lipophilicity,as evaluated using WLOGP.Amongst the tested compounds,procyanidin B2 showed the highest lipophilic value.It is worth mentioning that these natural inhibitiors of SARS-CoV-2 main protease are components of green and black tea that can be used as a supporting supplement for COVID patients or as potential nuclei for further drug design and development campaigns.

Performance enhancement of a DC-operated micropump with electroosmosis in a hybrid nanofluid:fractional Cattaneo heat flux problem

The purpose of this investigation is to theoretically shed some light on the effect of the unsteady electroosmotic flow(EOF)of an incompressible fractional secondgrade fluid with low-dense mixtures of two spherical nanoparticles,copper,and titanium.The flow of the hybrid nanofluid takes place through a vertical micro-channel.A fractional Cattaneo model with heat conduction is considered.For the DC-operated micropump,the Lorentz force is responsible for the pressure difference through the microchannel.The Debye-H¨ukel approximation is utilized to linearize the charge density.The semianalytical solutions for the velocity and heat equations are obtained with the Laplace and finite Fourier sine transforms and their numerical inverses.In addition to the analytical procedures,a numerical algorithm based on the finite difference method is introduced for the given domain.A comparison between the two solutions is presented.The variations of the velocity heat transfer against the enhancements in the pertinent parameters are thoroughly investigated graphically.It is noticed that the fractional-order parameter provides a crucial memory effect on the fluid and temperature fields.The present work has theoretical implications for biofluid-based microfluidic transport systems.

Conserved charges of Kerr-Ads spacetime using Poincaré gauge version

The process of covariant conserved charge of gravitational theory, which is covariant under general coordinate and local Lorentz transformations, has been applied to many tetrad fields, which reproduce Kerr-Ads spacetime, to calculate their conserved charges. It is shown that this process gives an infinite value of the conserved charges for Kerr–Ads spacetime. Therefore, the method of “regularization through relocalization”, i.e., modification of the Lagrangian of the gravitational field through a total derivative, is used. This method gaves a finite and a consistent result of total energy and angular momentum for Kerr–Ads spacetime.