SINGULAR PERTURBATION OF INITIAL BOUNDARY VALUE FROBLEMS OF REACTION DIFFUSlON EQUATION WITH DELAY

In this paper we consider the initial-boundary value problems for a class ofapplications, such as biomathematics and biochemistry.Applying the method ofcomposile expansion we construct the formally asymptotic solution of the problemdescribed. With the help of theory of upper and lower solutions we prove the uniformlyvalidity of the formal solution and the existence of solution of the original problem.

The Prognosis of Delayed Reactions in Rats Using Markov Chains Method

The original modified method of the direct delayed reaction has been used for the evaluation of food-obtaining strategy across spatial learning tasks in T-maze alternation. The optimal behavioral algorithms for each experimental day have been identified so that the animals obtain maximum possible food amount with minimal number of mistakes. Markov chain method has been used for the prognosis of rat’s behavioral strategy during the spatial learning task. The learning and decision-making represent the probabilistic transition process where the animal choice at each step (state) depends on the learning experience from previous step (state).

Stabilization strategy of a car-following model with multiple time delays of the drivers

An extended car-following model with multiple delays is constructed to describe driver's driving behavior.Through stability analysis,the stability condition of this uncontrolled model is given.To dampen the negative impact of the driver's multiple delays(i.e.,stability condition is not satisfied),a novel control strategy is proposed to assist the driver in adjusting vehicle operation.The control strategy consists of two parts:the design of control term as well as the design of the parameters in the term.Bifurcation analysis is performed to illustrate the necessity of the design of parameters in control terms.In the course of the design of parameters in the control term,we improve the definite integral stability method to reduce the iterations by incorporating the characteristics of bifurcation,which can determine the appropriate parameters in the control terms more quickly.Finally,in the case study,we validate the control strategy by utilizing measured data and configuring scenario,which is closer to the actual traffic.The results of validation show that the control strategy can effectively stabilize the unstable traffic flow caused by driver's delays.

Delayed inflammatory response evoked in nasal alloplastic implants after COVID-19 vaccination: A case report

BACKGROUND Delayed inflammatory reactions(DIRs)in alloplast rhinoplasty are a rare complication that may occur several months to years after surgery.The exact causes and mechanisms are unclear,but several triggering factors,including infections,trauma,dental procedures,and vaccination,have been reported.CASE SUMMARY A 39-year-old male patient who had undergone augmentation rhinoplasty 8 years ago had DIRs after the administration of the first dose of the mRNA Pfizer coronavirus disease 2019(COVID-19)vaccine.He suddenly had tender,erythematous swelling on his face 6 d after vaccination.As there was no improvement in the patient’s condition after the conservative treatment,surgical removal of an alloplastic nasal implant was performed.Immediately after the surgery,the DIRs and accompanying symptoms ameliorated rapidly.A histological study conducted during surgery was fibrosis and small fragments of the hyaline cartilage.CONCLUSION The correlation between DIRs and COVID-19 vaccination has not been reported yet and the exact mechanism is unclear.Because the uncontrolled inflammatory reactions on the nose leave serious sequelae,surgeons should be conscious of the correlation between COVID-19 vaccines and DIRs associated with nasal alloplastic implants.And further histological or microbiological studies should be performed to determine the cause of DIRs.

EXPONENTIAL TIME DIFFERENCING-PADE FINITE ELEMENT METHOD FOR NONLINEAR CONVECTION-DIFFUSION-REACTION EQUATIONS WITH TIME CONSTANT DELAY

In this paper,ETD3-Padéand ETD4-PadéGalerkin finite element methods are proposed and analyzed for nonlinear delayed convection-diffusion-reaction equations with Dirichlet boundary conditions.An ETD-based RK is used for time integration of the corresponding equation.To overcome a well-known difficulty of numerical instability associated with the computation of the exponential operator,the Padéapproach is used for such an exponential operator approximation,which in turn leads to the corresponding ETD-Padéschemes.An unconditional L^(2) numerical stability is proved for the proposed numerical schemes,under a global Lipshitz continuity assumption.In addition,optimal rate error estimates are provided,which gives the convergence order of O(k^(3)+h^(r))(ETD3-Padé)or O(k^(4)+h^(r))(ETD4-Padé)in the L^(2)norm,respectively.Numerical experiments are presented to demonstrate the robustness of the proposed numerical schemes.

ENERGY ESTIMATES FOR DELAY DIFFUSION-REACTION EQUATIONS

In this paper we consider nonlinear delay diffusion-reaction equations with initial and Dirichlet boundary conditions. The behaviour and the stability of the solution of such initial boundary value problems （IBVPs） are studied using the energy method. Simple numerical methods are considered for the computation of numerical approximations to the solution of the nonlinear IBVPs. Using the discrete energy method we study the stability and convergence of the numerical approximations. Numerical experiments are carried out to illustrate our theoretical results.

Ant sting-induced whole-body pustules in an inebriated male:A case report

BACKGROUND Many ant species can harm humans;however,only a few cause life-threatening allergic reactions.Normally,reactions caused by ants occur in patients who come into contact with ant venom.Venom contains various biologically active peptides and protein components,of which acids and alkaloids tend to cause anaphylaxis.Ant venom can cause both immediate and delayed reactions.The main histopathological changes observed in ant hypersensitivity are eosinophil recruitment and Th2 cytokine production.CASE SUMMARY A 70-year-old man was bitten by a large number of ants when he was in a drunken stupor and was hospitalized at a local hospital.Five days later,because of severe symptoms,the patient was transferred to our hospital for treatment.Numerous pustules were observed interspersed throughout the body,with itching and pain reported.He had experienced fever,vomiting,hematochezia,mania,soliloquy,sleep disturbances,and elevated levels of myocardial enzymes since the onset of illness.The patient had a history of hypertension for more than 1 year,and his blood pressure was within the normal range after hypotensive drug treatment.He had no other relevant medical history.Based on the clinical history of an ant bite and its clinical manifestations,the patient was diagnosed with an ant venom allergy.The patient was treated with 60 mg methylprednisolone for 2 d,40 mg methylprednisolone for 3 d,and 20 mg methylprednisolone for 2 d.Oral antihistamines and diazepam were administered for 12 d and 8 d,respectively.Cold compresses were used to treat the swelling during the process.After 12 d of treatment,most pustules became crusts,whereas some had faded away.No symptoms of pain,itching,or psychological disturbances were reported during the follow-up visits within 6 mo.CONCLUSION This case report emphasizes the dangers of ant stings.

Effect of plasma on combustion characteristics of boron

As it is very difficult to release boron energy completely, kinetic mechanism of boron is not clear, which leads to the lack of theoretical guidance for studying how to accelerate boron combustion. A new semi-empirical boron combustion model is built on the King combustion model, which contains a chemical reaction path; two new methods of plasma-assisted boron combustion based on kinetic and thermal effects respectively are built on the ZDPLASKIN zero-dimensional plasma model. A plasma-supporting system is constructed based on the planar flame, discharge characteristics and the spectral characteristics of plasma and boron combustion are analyzed. The results show that discharge power does not change the sorts of excited-particles, but which can change the concentration of excited-particles. Under this experimental condition,plasma kinetic effect will become the strongest at the discharge power of 40 W; when the discharge power is less than 40 W,plasma mainly has kinetic effect, otherwise plasma has thermal effect. Numerical simulation result based on plasma kinetic effect is consistent with the experimental result at the discharge power of 40 W, and boron ignition delay time is shortened by 53.8% at the discharge power of 40 W, which indicates that plasma accelerates boron combustion has reaction kinetic paths, while the ability to accelerate boron combustion based on thermal effect is limited.

DEL RBC transfusion should be avoided in particular blood recipient in East Asia due to allosensitization and ineffectiveness

Previously, both primary and secondary anti-D alloimmunizations induced by "Asian type" DEL (RHD1227A allele) were observed in two incidents. We investigated how often these alloimmunization events occur. The transfusions of any D-negative patients were investigated in the First Affiliated Hospital of Xi'an Jiaotong University Medical College, China, during the entire 2009. The antigens of D, C, c, E, and e were routinely serotyped. The "Asian type" DEL variant was genotyped and the RHD heterozygote was determined through two published methods. The changes in anti-D levels were monitored by the indirect antiglobulin test (IAT) and flow cytometry. Thirty D-negative transfused patients were included in the study. We focused on 11 recipients who were transfused with packed red blood cells (RBCs) from DEL donors at least one time. Of those 11 recipients, seven were anti-D negative before transfusion and four were anti-D positive (one patient with an autoantibody). One of the seven pre-transfusion anti-D negative patients produced a primary-response anti-D after being transfused with 400 ml of DEL blood twice. All four pre-transfusion antibody positive patients were not observed hemoglobin (Hb) levels increased, as expected after transfusions. Two patients had an increase in anti-D from 1:8 to 1:64 by IAT, which was also shown by flow cytometry. None of the patients experienced an acute hemolytic episode. Our data indicated that the primary anti-D induced by DEL transfusion or the secondary anti-D elevated by DEL in a truly D-negative patient might not be unusual. We suggest that a truly D-negative childbearing-aged woman should avoid DEL transfusion to protect her from primary anti-D allosensitization. In addition, anti-D positive recipients should also avoid DEL red cell transfusion due to the delayed hemolytic transfusion reaction (DHTR).