A New Combined Model for considering the Plasticity Effects in Contacting Asperities

Wheel-rail contact in railway engineering is an important topic. Due to different materials and surface roughness of wheel and rail, the contact characteristics can alter significantly. This article aims to investigate the effects of surface roughness and asperities on the contact parameters such as contact area, contact force, and contact stiffness. The lateral contacts between asperities are assumed to be the general contact condition. Azimuthal and contact angles distributions are assumed to be spherical harmonic distribution. This assumption is compatible with the asperity distribution on the wheel and the rail surfaces. Besides, a new combined model is developed to cover the stick-slip and the plasticity effects in contacting asperities. The results of the presented model offer very good estimations for the asperities contact characteristics, especially at the small-contact area and separation where high-contact pressure and plastic deformation usually exist

Interaction between non-coding RNAs and Toll-like receptors

Toll-like receptors (TLRs) are a large group of pattern recognition receptors which are involved in the regulation of innate immune responses. Based on the interplay between TLRs and adapter molecules, two distinctive signaling cascades, namely the MyD88-dependent and TRIF-dependent pathways have been recognized. TLRs are involved in the development of a wide variety of diseases including cancer and autoimmune disorders. A large body of evidence has shown interaction between two classes of non-coding RNAs, namely microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). These interactions have prominent roles in the pathogenesis of several disorders including infectious disorders, autoimmune conditions and neoplastic disorders. This review aims at description of the interaction between these non-coding RNAs and TLRs

COVID-19 in heart transplant recipients: A systematic review

Background. The high mortality and morbidity rate of COVID-19 turned this pandemic into the most challenging health issue. Here we systematically reviewed the consequences of COVID-19 in heart transplant recipients. Methods. The terms "Coronavirus" or "COVID19", "SARS-CoV-2", "Heart Transplantation", and "Cardiac Graft" were searched focusing on heart transplant patients with positive severe acute respiratory syndrome of coronavirus-2 (SARS-CoV-2) on June 22, 2022, in Web of Science / ISI, PubMed and Ovid ProQuest, Scopus. Results. The results showed that of 14 eligible studies that were included in the systematic review, 8 were case reports, and 6 case series. Among 109 reported cases, 67 patients were male and 22 were female and about the rest, it was not reported. The minimum hospitalization day was one day and the maximum was 60 days. In three case reports, the studied patients died, and in one case series, 7 out of 28 patients died. The most reported symptoms were shortness of breath (85.7%), cough (76.2%), and myalgia/fatigue (76.2%), followed by rhinitis (66.7%) and fever (7.7%). 66 percent). Conclusion. Although the symptoms of the disease in these patients are similar to other patients, the mortality rate is high. Considering that the studies conducted on heart transplant recipients with covid-19 have mostly been in the form of case studies, it is suggested that larger studies be conducted so that more accurate information can be obtained regarding the survival rate, symptoms of the disease, and the type of drugs used. Practical Implications. The mortality rate of heart transplant cases affected by COVID-19 was 23.6% (21 patients).In four studies the duration of hospitalization was not mentioned, but the others varied from no hospitalization in one case to up to 60 days. The most reported symptoms were dyspnea (85.7%), cough (76.2%), and myalgia/fatigue (76.2%), followed by rhinitis (66.7%) and fever (66.7%). Treatment differed for each patient, but hydroxychloroquine, antibiotic therapy including Azithromycin, and lopinavir/ritonavir were the most commonly used drugs

Neuropsychiatric manifestations of COVID-19 can be clustered in three distinct symptom categories

Several studies have reported clinical manifestations of the new coronavirus disease. However, few studies have systematically evaluated the neuropsychiatric complications of COVID-19. We reviewed the medical records of 201 patients with confirmed COVID-19 (52 outpatients and 149 inpatients) that were treated in a large referral center in Tehran, Iran from March 2019 to May 2020. We used clustering approach to categorize clinical symptoms. One hundred and fifty-one patients showed at least one neuropsychiatric symptom. Limb force reductions, headache followed by anosmia, hypogeusia were among the most common neuropsychiatric symptoms in COVID-19 patients. Hierarchical clustering analysis showed that neuropsychiatric symptoms group together in three distinct groups: anosmia and hypogeusia; dizziness, headache, and limb force reduction; photophobia, mental state change, hallucination, vision and speech problem, seizure, stroke, and balance disturbance. Three non-neuropsychiatric cluster of symptoms included diarrhea and nausea; cough and dyspnea; and fever and weakness. Neuropsychiatric presentations are very prevalent and heterogeneous in patients with coronavirus 2 infection and these heterogeneous presentations may be originating from different underlying mechanisms. Anosmia and hypogeusia seem to be distinct from more general constitutional-like and more specific neuropsychiatric symptoms. Skeletal muscular manifestations might be a constitutional or a neuropsychiatric symptom