Energy Transfer and Coherence in Coupled Oscillators with Delayed Coupling: A Classical Picture for Two-Level Systems

The Frimmer-Novotny model to simulate two-level systems by coupled oscillators is extended by incorporating a constant time delay in the coupling. The effects of the introduced delay on system dynamics and two-level modeling are then investigated and found substantial. Mathematically, introducing a delay converts the dynamical system from a finite one into an infinite-dimensional system. The resulted system of delay differential equations is solved using the Krylov method with Chebyshev interpolation and post-processing refinement. The calculations and analyses reveal the critical role that a delay can play. It has oscillatory effects as the main dynamical eigenmodes move around a circle with a radius proportional to the coupling strength and an angle linear with the delay. This alteration governs the energy transfer dynamics and coherence. Accordingly, both, the delay and the coupling strength dictate the stability of the system. The delay is the main related parameter as for certain intervals of it, the system remains stable regardless of the coupling. A significant effect occurs when one of the main modes crosses the imaginary axis, where it becomes pure imaginary and dampingless. Thus, the two states energies can live and be exchanged for an extremely long time. Furthermore, it is found that the delay alters both the splitting and the linewidth in a way further influencing the energy transfer and coherence. It is found also that the delay should not be large to have significant effect. For example, for an optical system with 500 nm wavelength, the critical delay can be in tens of attoseconds

Immunoinformatics Patterns and Characteristic of Epitope-Based Peptide Vaccine candidates against COVID-19

Vaccination as defined by the WHO is “the administration of agent-specific, but safe, antigenic components that in vaccinated individuals can induce protective immunity against the corresponding infectious agent”. Regardless of their debated history, the standard vaccine approaches have been unsuccessful in providing vaccines for numerous infectious organisms. In the recent three decades, an enormous amount of immunological data was retrieved from clinical studies  due to the advancement in human genome sequencing. These data are being deposited in databases and numerous scientific literature. The development of several bioinformatics tools to analyze this rapidly increasing immunological databank has given rise to the field of immunoinformatics. This approach allows the selection of immunogenic residues from the pathogen genomes. The ideal residues could be industrialized as vaccine candidates to provide protective immune responses in the hosts. This methodology will significantly decrease the time and cost needed for the vaccine development.  This review focus on  published articles that proposed as vaccine candidates through immunoinformatics analysis. The reviewed  Published immunoinformatics studies provided vaccine peptide candidates against SARS-COV-2, which is based on functional and non functional immunogenic proteins like open reading frame , spike protein, envelope protein and membranous protein .All of which  are designed by unique strategies like reverse vaccinology . Spike protein was the most common used target with different suggeststed B and T cell peptides  due to the difference in methodology between the findings

Estimation of seismic moments from local magnitudes and coda durations for the Cairo earthquake aftershocks recorded at Kottamyia (KEG) Broadband station

The spectral analysis of fifty-five KEG VBB records from the October 12, 1992 Cairo earthquake source region was performed to obtain the seismic moment. We obtained this parameter in turn to develop empirical local magnitude (ML), seismic moment (Mo), coda duration (D) relations for that region. In this study the data consist of Lg-waves on the vertical component seismograms for the recorded earthquakes with ML ranging from 1.7 to 4.7. The derived empirical relation between the seismic moment (Mo) and magnitude ML for the aftershocks sequence with 1.7 = ML < 3.5 is Log (Mo) = (0.96 ± 0.05) ML + (17.88 ± 0.13). We found a correlation between the coda duration (D) and Log of the moment (Log (Mo)) as follows: Log (Mo) = (2.35 ± 0.27) Log (D) + (16.33 ± 0.48)

Cytokine Storm in COVID-19 Patients, their Impact on Organs and the Potential Treatment by QTY Code-Designed Detergent-Free Chemokine Receptors

The novel coronavirus in not only causing respiratory problems, it may also damage the heart, kidneys, liver and other organs; in Wuhan 14 to 30% of COVID-19 patients have lost their kidney function and now require either dialysis or kidney transplants. The novel coronavirus gains entry into humans by targeting ACE2 receptor that found on lung cells, which destroy human lungs through cytokine storms, this leads to hyper-inflammation, forcing the immune cells to destroy healthy cells. This is why some COVID-19 patients need intensive care. The inflammatory chemicals released during COVID-19 infection cause the liver to produce proteins that defend the body from infections. However, these proteins can cause blood clotting, which can clog blood vessels in the heart and other organs; as a result, the organs are deprived from oxygen and nutrients which could ultimately lead to multi-organ failure and subsequent progression to acute lung injury, acute respiratory distress syndrome and often death. However, a novel protein modification tool called the QTY code, that are similar in their structure to antibodies, which could provide a solution to excess cytokines, these synthetic proteins can be injected into the body to blind the excess cytokines generated by the cytokine storm; this will eventually remove the excessive cytokines and inhibit the severe symptoms caused by the COVID-19 infection. In this review we will focuses on cytokine storm in COVID-19 patients, their impact on the organs and the potential treatment by QTY code-designed detergent-free chemokine receptors

A doctor recommender system based on collaborative and content filtering

The volume of healthcare information available on the internet has exploded in recent years. Nowadays, many online healthcare platforms provide patients with detailed information about doctors. However, one of the most important challenges of such platforms is the lack of personalized services for supporting patients in selecting the best-suited doctors. In particular, it becomes extremely time-consuming and difficult for patients to search through all the available doctors. Recommender systems provide a solution to this problem by helping patients gain access to accommodating personalized services, specifically, finding doctors who match their preferences and needs. This paper proposes a hybrid content-based multi-criteria collaborative filtering approach for helping patients find the best-suited doctors who meet their preferences accurately. The proposed approach exploits multi-criteria decision making, doctor reputation score, and content information of doctors in order to increase the quality of recommendations and reduce the influence of data sparsity. The experimental results based on a real-world healthcare multi-criteria (MC) rating dataset show that the proposed approach works effectively with regard to predictive accuracy and coverage under extreme levels of sparsity

Clinical Presentation and Time-Based Mortality in Patients With Chest Injuries Associated With Road Traffic Accidents

Background: Blunt chest trauma (BCT) poses significant morbidity and mortality worldwide. Objectives: We investigated the clinical presentation and outcome of BCT related to road traffic accidents (RTA). Patients and Methods: A retrospective observational analysis for patients who sustained BCT secondary to RTA in terms of motor vehicle crash (MVC) and pedestrian-motor vehicle accidents (PMVA) who were admitted to the trauma center at Hamad general hospital, Doha, Qatar, between 2008 and 2011. Results: Of 5118 traumatic injury cases, 1004 (20%) were found to have BCT secondary to RTA (77% MVC and 23% PMVA). The majority were males (92%), and expatriates (72%). Among MVCs, 84% reported they did not use protective devices. There was a correlation between chest abbreviated injury score (AIS) and injury severity scoring (ISS) (r = 0.35, r2 = 0.12, P < 0.001). Regardless of mechanism of injury (MOI), multivariate analysis showed that the head injury associated with chest AIS and ISS was a predictor of mortality in BCT. Overall mortality was 15%, and the highest rate was observed within the first 24 hours post-trauma. Conclusions: Blunt chest trauma from RTA represents one-fifth of the total trauma admissions in Qatar, with a high overall mortality. Pedestrians are likely to have more severe injuries and higher fatality rates than MVC victims. Specific injury prevention programs focusing on road safety should be implemented to minimize the incidence of such preventable injuries

Shear Performance of GFRP Reinforced Concrete Beams with Seawater and Chopped Fiber

This paper reports an experimental study on the behavior and shear strength of concrete beams reinforced with longitudinal GFRP bars mixed with sea water. In order to evaluate how much concrete contributes to shear resistance, seven beams were tested in bending. Similar in size and concrete strength, the beams were longitudinally reinforced with glass fiber-reinforced polymer bars; however, they did not even have shear reinforcement. The beams, which measured 3,100 mm in length, 400 mm in depth, and 200 mm in width, were conducted and tested up to failure. The test variables were longitudinal reinforcement ratios (1.0, 1.4, and 2.0%), chopped fiber content (0, 0.5, 2, and 3 kg/m3), and mixing water type (freshwater and seawater). The test findings showed that increasing the reinforcement ratio increased the neutral-axis depth and allowed the formation of more closely spaced fractures while decreasing the loss of flexural stiffness after cracking. By increasing the area of concrete in compression, this in turn enhances the contribution of aggregate interlock as well as the contribution of uncracked concrete. Furthermore, increasing the reinforcement ratio improves the dowel action, which reduces the tensile stresses that are created in the concrete around it. Doi: 10.28991/CEJ-2023-09-04-05 Full Text: PD

Accelerated versus Standard Corneal Cross-linking for Progressive Keratoconus in Syria

Purpose: To compare the outcomes of accelerated versus standard corneal cross-linking for the treatment of progressive keratoconus. Methods: In this retrospective comparative study, 63 eyes of 40 patients with progressive keratoconus were divided into two groups; 27 eyes in group one were treated with an accelerated protocol (10 mW/cm2, 9 min) and 36 eyes in group two were treated with the standard method (3 mW/cm2, 30 min). Visual acuity, refraction, corneal topography, corneal tomography, and anterior and posterior corneal higher-order aberrations (HOAs) were assessed preoperatively and 18–30 months postoperatively. Results: The LogMAR uncorrected and corrected distance visual acuity values were improved in both groups postoperatively. However, the improvement was significantly higher in group one (P &lt; 0.05, all). The flattening in the anterior keratometry readings, flat K, steep K, and average K were significantly higher in group two (P &lt; 0.001, all). The maximum anterior keratometry (AKf) values significantly decreased in both groups, whereas the maximum posterior keratometry (AKb) values increased. The reduction in the minimum corneal thickness (ThKmin) was significantly greater (36.49um) in group two, compared to 10.85um in group one. There was a significant increase in the posterior average keratometry, and a significant decrease in the posterior astigmatism, along 3 mm meridian in S-CXL (P = 0.03, P = 0.008, respectively), while the corresponding values showed no statistical significance in group one (P &gt; 0.05). The anterior corneal trefoil was significantly reduced in group one (P = 0.002), whereas anterior total HOAs and coma were significantly improved in group two (P &lt; 0.0014, all). The posterior corneal spherical aberration decreased significantly in group one (P = 0.02), while group two revealed significant reduction in the posterior trefoil values (P = 0.011). The change in the anterior maximum keratometry was significantly and positively correlated to the preoperative maximum keratometry in group two (P = 0.53, P = 0.003). Conclusion: An accelerated cross-linking protocol using 10 mW/cm2 for 9 min showed more visual improvement and less pachymetric reduction when compared to the standard protocol, however, anterior corneal flattening, posterior corneal steepening, and the change in the posterior astigmatism were significantly higher in the standard protocol; while corneal HOAs were improved in both protocols