Anomalous Reaction Research Articles

Asymptotic Behavior of Global Solution of an Anomalous Gray Scott Model

The object of this paper is to prove that existence global and asymptotic behavior of solutions for anomalous coupled reaction diffusion system (Gray Scott model) with homogeneous Neumann boundary conditions. The existence and uniqueness of the local solution are given by the Banach fixed point theorem. However, the asymptotic behavior is investiged by technique semi group estimates and the Sobolev embedding theorem

Anomalous reaction of Saucedo-etching on CdZnTeSe crystal

CdTe-based materials are vital for charge-collecting devices such as solar cells and radiation detectors. This study investigates anomalous reaction between Se-added CdTe-based crystal and Saucedo-etchant unexpectedly unveiled. CZT and CZTS ingots were grown, and anomalous patterns were explored using EPMA, XPS, and SEM-EDS. The unique pattern from Saucedo-etching on CZTS was attributed to Ag2Se formation. These findings offer guidance into dislocation research in Se-added CdTe-based semiconductors.

A newly constructed numerical approximation and analysis of Generalized fractional Burger-Huxley equation using higher order method

In this manuscript, the collocation approach using the higher order extended cubic B-spline (ECBS) as the basis function is efficiently used to numerically solve the generalized time fractional Burger-Huxley equation (TFBHE). The Burger-Huxley equation is a widely studied nonlinear partial differential equation that models the propagation of nerve impulses in excitable systems such as the neurons in the brain. The time fractional versions of the Burger-Huxley equation (BHE), which incorporate fractional derivatives in time direction to model the anomalous diffusion, reaction mechanism, and memory effects observed in many physical and biological systems. The θ−weighted technique and the Atangana–Baleanu operator are employed to discretize the equation. The higher order EBCS method is used in space direction. The stability and convergence analysis are also presented. Numerous examples are carried out to show the validity of the technique. The graphical representations and computed results are observed the good agreement with the literature.

S2266 Achalasia as a Sequelae of COVID-19

Introduction: Achalasia is a neurodegenerative motility disorder of distal esophagus and lower esophageal sphincter characterized by loss of myenteric neurons in esophagus. It therefore results in deranged peristalsis and characteristic manifestations of regurgitation, dysphagia and retrosternal chest pressure sensation. Recent studies have suggested inflammatory neurodegenerative insult from viral infection as a potential etiology. Sars-Cov-2 causes multiple gastrointestinal (GI) manifestations like ageusia, nausea, vomiting, pain and diarrhea. We present a rare case of achalasia that presented soon after COVID infection in an otherwise healthy male. Case Description/Methods: A 63-year-old man was referred for further evaluation of dysphagia that started a few months after a non-severe COVID infection with associated ageusia. He reported progressive dysphagia to both solids and liquids with concomitant regurgitation and chest pain. By the time he presented, he had lost 45 lbs over the course of 6 months and had an Eckardt score of 8. High resolution manometry was suggestive of evolving type II achalasia. A follow up Endoflip exam with a 16 cm catheter inflated to 60 cc revealed a esophagogastric diameter of 7.3 mm and a distensibility index (DI) of 1.9. Timed barium esophagogram showed a 5 cm contrast column in distal esophagus at 5 minutes. The patient has since been referred for per oral endoscopic myotomy (Figure). Discussion: Sars-Cov-2 enters the GI epithelial cells through ACE2 receptors and exerts its effects through an aberrant immune response involving T- lymphocytes rather than direct epithelial damage. An anomalous immune reaction resulting in degeneration of inhibitory neurons in the myenteric plexus may be the cause of achalasia in COVID-19. On literature review, we came across at least 1 case report of a patient developing achalasia after COVID-19. A Venezuelan study noted that the frequency of patients with achalasia during the year 2020 and 2021 was far greater than those of previous years and at least 2/3rd of these patients had presented with COVID-19 infection. It will be interesting to note if coronavirus can be isolated from muscle biopsies of these subjects as has been the case with VZV previously. Further investigation especially into patients presenting with GI symptoms with COVID infection is warranted.Figure 1.: Endoflip ; Barium Esophageogram.

C80 SUDDEN CARDIAC ARREST IN A YOUNG FOOTBALL PLAYER DUE TO DOCUMENTED SPONTANEOUS CORONARY ARTERY DISSECTION

Abstract A 28–years–old male presented with sudden cardiac arrest (SCA) while playing soccer. He was quickly resuscitated and transported to the closest cardiology department. He had no ECG or echocardiographic alterations. Coronary angiography (CA) showed a spontaneous coronary artery dissection (SCAD), confirmed by optical coherence tomography (OCT), in the mid portion of left anterior descending artery (LADA). In light of his young age, and the lack of evidence of stenosis on angiography confirmed by an instant wave–free ratio (iFR) analysis that confirmed the absence of myocardial ischemia (value obtained 0.97), the patient was treated conservatively with aspirin, clopidogrel, a statin and a beta–blocker. The patient refused implantation of a cardioverter–defibrillator repeatedly. A repeat CA was performed 6–months later, showing same findings and angiographic images of the known lesion involving the LADA. Therefore, the patient was indicated as unsuitable to play soccer. At 1 year from the index event, the patient had an episode of angina pectoris associated with intensive effort and, because of this, another CA with OCT analysis were performed. On angiography the LADA showed a significant stenosis in the same region where spontaneous dissection was previously documented; finding of hyperreflectivity on OCT suggested fibrosis of the vessel wall, probably caused by anomalous immunity reaction mimicking an autoimmune disease; residual intimal–tear representing the entry–site of the dissection was also detected, and a minimal lumen area of 2.21 mm2 was calculated consistent with angiographic stenosis. PCI was indicated, implanting a 3.0/18 mm drug–eluting stent in the mid portion of the LADA, obtaining good final angiographic result and OCT analysis confirming optimal device expansion, without residual dissection. At 2 month post–PCI the patient had returned to playing football without limitation of physical activities. 1 year post–PCI follow–up the patient is still asymptomatic and healthy. In summary, we present a case of SCAD causing an acute coronary syndrome presenting with SCA, which limited subsequent physical activity. In young patients, mostly women, SCAD episode should be strongly considered in the setting of an acute coronary syndrome. Several articles had reported that medical therapy should be oriented on the pathophysiology of SCAD due to the absence of the classic atherosclerotic burst, limiting interventional therapy when strictly indicated.

Robust point control for a class of fractional-order reaction–diffusion systems via non-collocated point measurement

In this paper, stabilization problem of a class of anomalous reaction diffusion systems described by fractional-order reaction–diffusion equations (FRDEs) is studied via robust point control using non-collocated point measurement. To get over the difficulty created by non-collocated point measurement, an Luenberger-type FPDE state observer is established firstly. And then, observer-based output feedback controllers are designed for three cases: the number of controllers is less than and great than or equals to that of the observers’. By utilizing Lyapunov direct method, sufficient conditions of Mittag-Leffler (M-L) stability for FRDEs are derived in the form of linear matrix inequalities (LMIs), and the robustness analysis of the controllers to the reaction coefficient and diffusion coefficient of the system is given. Finally, numerical simulation shows the feasibility and validity of the proposed control method.

Numerical study of the nonlinear anomalous reaction–subdiffusion process arising in the electroanalytical chemistry

This paper presents a meshless method based on the finite difference scheme derived from the local radial basis function (RBF-FD). The algorithm is used for finding the approximate solution of nonlinear anomalous reaction–diffusion models. The time discretization procedure is carried out by means of a weighted discrete scheme covering second-order approximation, while the spatial discretization is accomplished using the RBF-FD. The theoretical discussion validates the stability and convergence of the time-discretized formulation which are analyzed in the perspective to the H1-norm. This approach benefits from a local collocation technique to estimate the differential operators using the weighted differences over local collection nodes through the RBF expansion. Two test problems illustrate the computational efficiency of the approach. Numerical simulations highlight the performance of the method that provides accurate solutions on complex domains with any distribution node type.

Protein immobilization on polyvinylphenol via tyrosine oxidation of proteins catalyzed by horseradish peroxidase

AbstractSurface functionalization of polymeric materials holds great potential in biological and medical fields with the aim toward realizing desired biological reactions (e.g., cell adhesion, and immune response), especially for proteins which have physiological functions. The objective was to examine characteristics of a unique and facile protein immobilization on a phenol‐containing polymeric material utilizing horseradish peroxidase (HRP) and tyrosine residues of target proteins as catalyst and substrates, respectively. Cy3‐labeled streptavidin exhibited the predicted immobilization behavior since the reaction effectively proceeded in the presence of HRP‐H2O2 and on the surface of polyvinylphenol. This procedure was applicable to other representative proteins, that is, bovine serum albumin, immunoglobulin G (IgG), and HRP as substrates. However, IgG exhibited anomalous reaction behavior under the present reaction condition probably due to its rich tyrosine content. Undesired immobilization of HRP was minimized by addition of large amounts of a competitive substrate. The biotin‐binding affinity of streptavidin‐immobilized surface was confirmed to maintain activity even after the immobilization procedure.

Additional Lithium Storage on Dynamic Electrode Surface by Charge Redistribution in Inactive Ru Metal.

Beyond a traditional view that metal nanoparticles formed upon electrochemical reaction are inactive against lithium, recently their electrochemical participations are manifested and elucidated as catalytic and interfacial effects. Here, ruthenium metal composed of ≈5 nm nanoparticles is prepared and the pure ruthenium as a lithium-ion battery anode for complete understanding on anomalous lithium storage reaction mechanism is designed. In particular, the pure metal electrode is intended for eliminating the electrochemical reaction-derived Li2 O phase accompanied by catalytic Li2 O decomposition and the interfacial lithium storage at Ru/Li2 O phase boundary, and thereby focusing on the ruthenium itself in exploring its electrochemical reactivity. Intriguingly, unusual lithium storage not involving redox reactions with electron transfer but leading to lattice expansion is identified in the ruthenium electrode. Size-dependent charge redistribution at surface enables additional lithium adsorption to occur on the inactive but more environmentally sensitive nanoparticles, providing innovative insight into dynamic electrode environments in rechargeable lithium chemistry.

Hydrogen evolution on bare Mg surfaces using the scratched electrode technique

The scratched electrode technique is used to study reaction rates of bared Mg surfaces with the aim of studying the anomalous hydrogen evolution phenomenon. Scratched Mg surfaces are more catalytic than filmed unscratched surfaces to dissolution and hydrogen evolution reactions and repassivation happens within milliseconds at anodic potentials in NaOH solution. The rate of anomalous hydrogen evolution reaction depends on surface condition, which for the bared scratch surface varies little with potential in this electrolyte. The reformation of an hydroxide monolayer limits dissolution and hydrogen evolution reactions. In environments containing chloride and sulfate, formation of a monolayer is less effective.

Mark Twain among the Indians and Other Indigenous Peoples

Mark Twain among the Indians and Other Indigenous Peoples

On the Fractional Diffusion-Advection-Reaction Equation in ℝ

Abstract We present an analysis of existence, uniqueness, and smoothness of the solution to a class of fractional ordinary differential equations posed on the whole real line that models a steady state behavior of a certain anomalous diffusion, advection, and reaction. The anomalous diffusion is modeled by the fractional Riemann-Liouville differential operators. The strong solution of the equation is sought in a Sobolev space defined by means of Fourier Transform. The key component of the analysis hinges on a characterization of this Sobolev space with the Riemann-Liouville derivatives that are understood in a weak sense. The existence, uniqueness, and smoothness of the solution is demonstrated with the assistance of several tools from functional and harmonic analyses.

An efficient meshless computational technique to simulate nonlinear anomalous reaction–diffusion process in two-dimensional space

In this paper, a numerical simulation of an anomalous reaction–diffusion process in two-dimensional space with a nonlinear source term is presented. An efficient and powerful computational technique based on a combination of a time integration scheme and meshless local Petrov–Galerkin method is implemented for solving the problem. An implicit time stepping scheme with second-order accuracy is used to discretize the problem in the time direction. The unconditional stability of the proposed time discretization scheme is proved in an appropriate Sobolev space. In order to obtain a fully discrete model, the primary spatial domain is represented by a set of regularly distributed nodes and spatial shape functions are constructed on the distributed field nodes using the radial point interpolation method. Then, a local weak form meshless method based on the radial point interpolation shape functions is used to discretize the problem in the spatial direction. The efficiency and accuracy of the proposed computational procedure are demonstrated by numerical examples. Numerical results show that the method approximates solutions of the model in excellent agreement with analytical results. Moreover, it can be observed that the method gives the expected second-order temporal convergence rate independent of the fractional order which confirms the theoretical predictions.

Sensitivity analysis of plasma edge code parameters through algorithmic differentiation

Anomalous radial transport coefficients, boundary conditions and reaction rates are among the main sources of uncertainty within plasma edge modeling. In principle, an analysis to determine the sensitivity of code results to changes in uncertain model parameters can be easily implemented through finite differences. However, this incurs in error accumulations and allows scanning only one parameter at a time, requiring a huge computational effort. Algorithmic Differentiation (AD) is a possible alternative to finite differences already applied to several transport codes in different research domains but not yet in plasma edge modeling. AD tools preprocess the source code, identifying elementary operations for which the differential form is well known, and producing a new version of the code that contains the additional derivative information. In this paper, the feasibility of applying AD to plasma edge codes is demonstrated using the TAPENADE tool on the SOLPS-ITER code. As a first preliminary step, the AD tool is applied in the so-called “forward” mode on the B2.5 plasma solver, adopting a fluid neutral approximation to obtain the sensitivities of the calculated quantities of interest on selected code parameters. The proof of principle is carried out by comparing the AD results with those evaluated with finite differences on an ITER H-only case. The sensitivities of the target peak heat load and maximum electron temperature with respect to anomalous radial transport coefficients and core input power are assessed. The comparison with finite differences results in a relative error lower than 10−6. This proves that, in a next step, AD can be exploited for an efficient and accurate sensitivity analysis in the framework of plasma edge simulations.

A Revised Mechanism for the Kinugasa Reaction.

Detailed kinetic analysis for the Cu(I)-catalyzed Kinugasa reaction forming β-lactams has revealed an anomalous overall zero-order reaction profile, due to opposing positive and negative orders in nitrone and alkyne, respectively. Furthermore, the reaction displays a second-order dependence on the catalyst, confirming the critical involvement of a postulated bis-Cu complex. Finally, reaction progress analysis of multiple byproducts has allowed a new mechanism, involving a common ketene intermediate to be delineated. Our results demonstrate that β-lactam synthesis through the Kinugasa reaction proceeds via a cascade involving (3 + 2) cycloaddition, (3 + 2) cycloreversion, and finally (2 + 2) cycloaddition. Our new mechanistic understanding has resulted in optimized reaction conditions to dramatically improve the yield of the target β-lactams and provides the first consistent mechanistic model to account for the formation of all common byproducts of the Kinugasa reaction.

Sodiation Behaviors of 1D Van Der Waals Sb2S3 Nanorods By in-Situ TEM and DFT Calculations

Owing to the abundance, low cost and similar electrochemistry of Na to Li, sodium ion batteries (SIBs) are considered an attractive, low-cost alternative to lithium ion batteries (LIBs) for large-scale energy storage [1]. Among various anode materials for SIBs, antimony trisulfide (Sb2S3) has drawn significant attention due its high theoretical capacity of 946 mAh g−1. However, its underlying sodiation behavior is largely unexplored. This work [2] reports the sodiation kinetics and the evolution of phase transformation in carbon-coated 1D van der Waals Sb2S3 nanorods based on the in-situ TEM, density functional theory (DFT) calculations and molecular dynamic (MD) simulations. Unique two-step reaction mechanisms of Sb2S3 nanorods are revealed, including Na+ ion intercalation and conversion/alloying reactions, during the first sodiation process. Na+ ions are inserted into the voids between the (Sb4S6)n moieties at an ultrafast speed of 146 nm s−1 upon the first sodiation, leading to amorphization of the crystalline Sb2S3 and negligible volume expansion of ~54 %. The in-situ SAED analysis verifies that the generated NaxSb2S3 intermediate phases are transformed into Na2S and Na3Sb with a trace of Sb crystals during the consecutive conversion/alloying reactions. Upon subsequent desodiation, the Na+ ions extracted from the crystalline sodiated composites transform to amorphous desodiated products. The DFT calculations attribute such anomalous reaction mechanisms to the unexpectedly low sodium diffusion barrier of Sb2S3 nanorods and the largely improved electronic conductivity arising from the amorphous NaxSb2S3 intermediate phases. These findings on phase transformation routes, dynamics and kinetics occurring during the sodiation/desodiation processes in the Sb2S3 nanostructure will offer insights into better understanding of Na+ ion diffusion mechanisms in van der Waals force stacked materials.

Anomalous heat-releasing phenomenon from bubbles in aluminum induced by electron beam irradiation

In the early 1990s, Japanese scholars unexpectedly observed that single crystal changes into polycrystal in deuterium-implanted aluminum under electron irradiation, but never found the same phenomenon in the hydrogen-implanted aluminum. However, previous study of our group has proved that the polycrystalline phenomenon can also be observed in hydrogen-implanted aluminum during electron irradiation. In this paper, the behavior of inert gas bubbles in aluminum under electron irradiation is investigated, aiming to further explore the effects of ion species, electron voltage and the pressure of bubbles on the anomalous heat-releasing reaction of bubbles induced by electron irradiation. In the experiment, the transmission electron microscope (TEM) samples of pure aluminum were implanted with He+, Ne+, Ar+ respectively by ion accelerator at room temperature. The TEM is used to in-situ observe and investigate the evolution of microstructure and the change of selected electron diffraction patterns of gas bubbles during electron irradiation. The results show that gas bubbles form in aluminum sample after ion implantation. During 200 keV electron irradiation TEM results show that the three kinds of inert gas bubbles all coalesce, grow up and bust separately. Finally, lots of nanoscale black dots appear inside them. At the same time, the electron diffraction patterns change from single crystal diffraction spots to polycrystalline diffraction rings. The dark field images indicate that the diffraction rings are induced by these black dots. Moreover, from the characterization of the diffraction rings, it is known that these black dots are pure aluminum rather than aluminum oxide. Therefore, the possibility that the diffraction rings result from aluminum oxide is eliminated. It is assumed that a certain kind of heat-releasing reaction should happen when the gas bubbles are irradiated by electrons, which leads to the poly-crystallization of aluminum after electron irradiation. However, while helium bubbles are irradiated by electrons with an energy of 80 keV, no diffraction ring is observed after electron irradiation. The same phenomenon as that in the case of helium bubbles irradiated by 80 keV electrons is observed. When helium and argon mixed bubbles with polygonal shape are irradiated by 200 keV electrons, no diffraction ring is observed after electron irradiation either. The reason might be related to the energy of the electron beam and the pressure of gas bubbles separately. There should be a threshold value of electron voltage for the heat-releasing reaction. In addition, the pressure of the gas bubbles is also a key factor for the heat-releasing reaction. The heat-releasing phenomenon of gas bubbles reminds us of the sonoluminescence phenomenon. By model calculation, it is predicted that there is a plasma core in the bubble during sonoluminescence. According to the hint from researches of sonoluminescence, an assumption is made to explain the mechanism of heat-releasing reaction of gas bubbles during electron irradiation. It is that the implanted gas in high pressure bubbles in aluminum is excited into plasma during electron irradiation. When the energy of plasma in the bubbles is accumulated to a certain degree, the plasma is extinguished suddenly. In this process, a lot of heat is released to melt the aluminum, thus leading the aluminum to recrystallize.

The (Not So Simple!) Chain Fountain

ABSTRACTGiven a sufficiently long bead chain in a cup, if we pull the end of the chain over the rim of the cup, the chain tends to continuously “flow” out of the cup, under gravity, in a common siphon process. Surprisingly enough, under certain conditions, the chain forms a fountain in the air! This became known as the Mould effect, after Steve Mould who discovered this phenomenon and made this experiment famous on YouTube [Mould 13] in a video that went viral. The reason for the emergence of this fountain remains unclear. This effect was shown [Biggins and Warner 14] to be due to an anomalous reaction force from the top of the pile of beads; a possible origin for this force was proposed in the same paper. Here, we describe some experiments that contribute toward the clarification of the origin of this force, and show that the explanation goes far beyond the one proposed in [Biggins and Warner 14].

Idiopathic pulmonary fibrosis as a possible exrtraesophageal manifestation of
 gastroesophageal reflux disease

Idiopathic pulmonary fibrosis (IPF) is a most widespread clinic-morphological variant of Idiopathic interstitial pneumonias. Its pathophysiology includes recurrent damages to epithelial cells and anomalous reparative reaction in response to aseptic inflammation in the form of excess fibroblast proliferation. The cause of epithelium damage remains unknown; the involvement of smoking, viral infections, inhaled pollutants, and toxic drug n the initiation of the pathological process is conjectured. Numerous studies of recent years suggest the potential role of gastroesophageal reflux and microaspiration as etiological factors of IPF progression. A brief review of modern views of the relationship between IPF and gastroesophageal reflux is presented.

ChemInform Abstract: Optimization and Multigram Scalability of a Catalytic Enantioselective Borylative Migration for the Synthesis of Functionalized Chiral Piperidines.

The development of new, efficient and economical methods for the preparation of functionalized, optically enriched piperidines is important in the field of drug discovery where this class of heterocycles is often deemed a privileged structure. We have optimized a Pd-catalyzed enantioselective borylative migration of an alkenyl nonaflate derivative of the simple precursor, N-Boc-4-piperidone. This anomalous borylation reaction lends access to a chiral optically enriched piperidinyl allylic boronate that can be employed in carbonyl allylboration and stereoselective cross-coupling to produce substituted dehydropiperidines related to numerous pharmaceutical agents. A systematic fine-tuning of reaction conditions revealed that diethyl ether and the green solvent cyclopentyl methyl ether are suitable reaction solvents providing the highest enantioselectivity (up to 92% ee) under a low catalyst loading of 3 mol%. Optimization of the aldehyde allylboration step led to higher yields with further solvent economy. The multigram-scalability of the entire process was demonstrated under the reaction conditions that provide optimal atom-economy and efficiency.