Trivial extensions defined by Prüfer conditions

AbstractThis paper deals with well-known extensions of the Prüfer domain concept to arbitrary commutative rings. We investigate the transfer of these notions in trivial ring extensions (also called idealizations) of commutative rings by modules and then generate original families of rings with zero-divisors subject to various Prüfer conditions. The new examples give further evidence for the validity of the Bazzoni–Glaz conjecture on the weak global dimension of Gaussian rings. Moreover, trivial ring extensions allow us to widen the scope of validity of Kaplansky–Tsang conjecture on the content ideal of Gaussian polynomials

Minimally invasive repair of pectus excavatum using the Nuss technique in children and adolescents: Indications, outcomes, and limitations

AbstractBackgroundPectus excavatum (PE) is a common congenital deformity. The Nuss technique for minimally invasive repair of PE involves thoracoscopy-assisted insertion of a bar or plate behind the deformity to displace the sternum anteriorly. Our objective here was to clarify the indications and limitations of the Nuss technique based on a review of 70 patients.Materials and methodsA retrospective review of children managed at two centres identified 70 patients who had completed their growth and had their plate removed. Mean age was 13.8 years (range, 6–19 years). The reason for surgery was cosmetic disfigurement in 66 (95%) patients. The original Nuss technique was used in 63 patients, whereas 7 patients required an additional sub-xiphoid approach. Time to implant removal ranged from 8 months to 3 years.ResultsThe cosmetic outcome was considered satisfactory by the patients in 64 (91%) cases and by the surgeon in 60 (85.7%) cases. Major complications requiring further surgery occurred in 6 (8.5%) patients and consisted of haemothorax (n=2), chest wall sepsis (n=2, including 1 after implant removal), allergy (n=1), and implant displacement (n=1). Early or delayed minor complications occurred in 46 (65%) patients and resolved either spontaneously or after non-surgical therapy.DiscussionThe minimal scarring and reliably good outcomes support the widespread use of the Nuss technique in children and adolescents. Our complication rates (minor, 65%; and major, 8.5%) are consistent with previous publications. In our opinion, contra-indications to thoracoscopic PE correction consist of a history of cardio-thoracic surgery and the finding by computed tomography of a sternum-to-spine distance of less than 5cm or of sternum rotation greater than 35°. In these situations, we recommend a sub- and retro-xiphoid approach to guide implant insertion or a classic sterno-chondroplasty procedure.Level of evidenceLevel IV, retrospective descriptive cohort study

State of Art and Challenges for the Calculation of Radiative and Transport Properties of Thermal Plasmas in HVCB

This paper is focused on the state-of-the-art and challenges concerning the thermophysical properties of thermal plasmas used in numerical modelling devoted to high voltage circuit breakers. For Local Thermodynamic Equilibrium (LTE) and Non-Local Thermodynamic (NLTE) and/or Chemical Equilibrium (NLCE) plasmas, the methods used to calculate the composition, thermodynamic, transport and radiative properties are presented. A review of these last data is proposed and some comparisons are given for illustrations

DFT and Molecular docking study of natural molecules proposed for COVID-19 treatment

AbstractEmergence and spread of corona virus disease 2019 (COVID-19), caused by severe respiratory syndrome coronavirus, is considered a public health emergency threatening global health systems, as of June, 2020, It caused a cumulative total of 9,033,423 confirmed cases and more than 469,539 deaths across 215 countries, person to-person transmission has being identified as the route for spreading. So far, the lack of effective vaccines for the treatment or prevention of Covid-19 has further worsened the situation. In this context, the present study aims to assess whether naturally occurring components have an antiviral effect via a computational modeling approach. Density Functional theory (DFT) was performed to estimate the kinetic parameters, frontier molecular orbitals, molecular electrostatic potential as well as chemical reactivity descriptors of various ligands. The results revealed that Crocin and Digitoxigenin exhibited a potential applicant with the lowest resistance to electronic charge transfer with a chemical hardness of 2.19eV and 2.96eV respectively, as well as the lowest HOMO-LUMO difference. In addition to the DFT calculation, a docking simulation study was conducted on the SARS-CoV-2 base protease (PDB: 6LU7) to determine the binding affinity of ligands. The findings show that Crocin exhibits the lowest binding energy of -8.1 Kcal/mol and may be a good inhibitor of CoV-2-SARS compared to hydroxychloroquine and chloroquine, which have a binding affinity of -5.4 and -4.9 Kcal/mol, respectively. The high binding affinity of L3 was assigned to the existence of 14 hydrogen bonds connecting the ligand to the critical amino acid residues of the receptor

Le lymphomes non hodgkinien primitif de la thyroïde: à propos de sept cas

Les lymphomes non hodgkiniens primitifs de la thyroïde sont rares : ils représentent moins de 2 à 5 % des cancers de la thyroïde. L’objectif de cetravail est de revoir les stratégies diagnostiques et thérapeutiques actuelles des lymphomes non hodgkiniens primitifs de la thyroïde tout enprésentant notre expérience à l’Institut national d’oncologie. Nous rapportons à travers une étude rétrospective, sept cas des lymphomes nonhodgkiniens primitifs de la thyroïde colligés à l’Institut National d’Oncologie au Maroc entre 2004 et 2008. Sept patients ont été inclus dans notre étude, l’âge médian au moment du diagnostic était de 50 ans, avec sexe ratio de 2.5 à prédominance féminine. Le diagnostic histopathologique avec l’immunomarquage après chirurgie a conclu dans tous les cas à un lymphome malin non hodgkinien : 3 patientes avec un lymphome de type MALT, et les 4 autres avec un LMNH à grandes cellules de phénotype B. Une thyroïdite chronique lymphocytaire d’Hashimoto coexistante avec le lymphome malin primitif de la thyroïde était retrouvée chez une patiente. Concernant le traitement du lymphome, 5 patientes ont reçu une polychimiothérapie, et les 2 autres ont bénéficié d’un traitement combiné comportant la chimiothérapie et la radiothérapie. Une patiente est décédée 3 mois après la fin du traitement. Le suivi médian des autres patients était de 24 mois et on ne notait aucune récidive de lymphome. Les lymphomes non hodgkiniens primitifs de la thyroïde sont rares. Le traitement combiné par une chimiothérapie et radiothérapie a prouvé sonefficacité. Le pronostic des stades localisés est généralement favorable. Key words: Lymphome primitif de la thyroïde, traitemen