Lesões Cutâneas Acrais Agudas Inflamatórias Vasculares Reativas e SARS-CoV-2

Introduction: Coronavirus disease 2019 (COVID-19) predominantly affects the respiratory system, but there have been many reports of skin involvement. Several cutaneous manifestations associated with COVID-19 have been identified, including acral lesions (pernio-like), which we intend to better characterize in this study. Methods: Demographic, clinical and major histopathologic characteristics of acral skin lesions occurring during the acute infection stage of COVID-19 disease were evaluated in this survey conducted in the Dermatology Division of Santa Casa Hospital Complex, Federal University of Health Sciences, Porto Alegre, Brazil. Results: In the present study, we evaluated eight female patients with acute SARS-CoV-2 infection confirmed by PCR with acral skin lesions including pernio-like. The mean age was 43.6 and with no other acute disease, who had a good outcome with need for hospitalization only in 2 cases. Pernio-like lesions were observed under hot weather conditions in patients who denied any previous history of similar cutaneous manifestations. Some acral lesions resembled those of lupus erythematosus and of herpes simplex paronychia, but laboratory tests were negative for those conditions. Unusual nail involvement was present, characterized by half-moon shaped erythematous bands at the distal margin of the lunula. Conclusion: Recognition of these skin lesions is important in that they could be potential markers, aiding in the diagnosis and prognosis of COVID-19 disease.Introdução: A doença coronavírus 2019 (COVID-19) afeta predominantemente o sistema respiratório, porém há múltiplos relatos de comprometimento da pele. Várias manifestações cutâneas foram identificadas, incluindo as de padrão acral (tipo eritema pérnio), as quais pretendemos caracterizar melhor neste estudo. Métodos: As principais características demográficas, clínicas e histopatológicas das lesões cutâneas acrais que ocorreram na fase aguda da infecção pela COVID-19 foram avaliadas nesta pesquisa realizada no Departamento de Dermatologia do Complexo Hospitalar Santa Casa e Universidade Federal de Ciências da Saúde de Porto Alegre, Brasil. Resultados: No presente estudo, avaliamos oito casos de infecção aguda por SARS-CoV-2 confirmados por PCR, com lesões cutâneas acrais incluindo aquelas tipo eritema pernio. Eram oito mulheres, com idade média de 43,6 anos, sem outra doença aguda, que tiveram uma boa evolução clínica com necessidade de hospitalização em apenas dois casos. Foram identificadas manifestações tipo eritema pérnio, surgidas em períodos onde o clima era de temperaturas elevadas, em pacientes que negaram quadros semelhantes prévios. Houve casos de lesões acrais semelhantes a lúpus eritematoso e paroníquia herpética cuja investigação laboratorial foi negativa para tais patologias. Evidenciaram-se inusi- tados acometimentos ungueais, em forma de meia-lua, com bandas eritematosas circundando a margem distal da lúnula. Conclusão: O reconhecimento destas lesões dermatológicas é importante, pois podem se revelar potenciais marcadores e auxiliarem no diagnóstico e prognóstico da doença COVID-19

How unique is the Asymptotic Normalisation Coefficient (ANC) method?

The asymptotic normalisation coefficients (ANC) for the vertex $^{10}$B $\to$ $^9$Be + p is deduced from a set of different proton transfer reactions at different energies. This set should ensure the peripheral character of the reaction and availability of data for the elastic channels. The problems associated with the characteristics of the data and the analysis are discussed. For a subgroup of the set of available data, the uniqueness property of the extracted ANC is fulfilled. However, more measurements are needed before a definite conclusion can be drawn.Comment: 19 pages, 11 figures, to be published in Phys Rev

DebriSat - A Planned Laboratory-Based Satellite Impact Experiment for Breakup Fragment Characterizations

The goal of the DebriSat project is to characterize fragments generated by a hypervelocity collision involving a modern satellite in low Earth orbit (LEO). The DebriSat project will update and expand upon the information obtained in the 1992 Satellite Orbital Debris Characterization Impact Test (SOCIT), which characterized the breakup of a 1960 s US Navy Transit satellite. There are three phases to this project: the design and fabrication of DebriSat - an engineering model representing a modern, 60-cm/50-kg class LEO satellite; conduction of a laboratory-based hypervelocity impact to catastrophically break up the satellite; and characterization of the properties of breakup fragments down to 2 mm in size. The data obtained, including fragment size, area-to-mass ratio, density, shape, material composition, optical properties, and radar cross-section distributions, will be used to supplement the DoD s and NASA s satellite breakup models to better describe the breakup outcome of a modern satellite

Preliminary Characterization Results from the DebriSat Project

The DebriSat project is a continuing effort sponsored by NASA and DoD to update existing break-up models using data obtained from two separate hypervelocity impact tests used to simulate on-orbit collisions. To protect the fragments resulting from the impact tests, "soft-catch" arenas made of polyurethane foam panels were utilized. After each impact test, the test chamber was cleaned and debris resulting from the catastrophic demise of the test article were collected and shipped to the University of Florida for post-impact processing. The post-impact processing activities include collecting, characterizing, and cataloging of the fragments. Since the impact tests, a team of students has been working to characterize the fragments in terms of their mass, size, shape, color and material content. The focus of the 20 months since the impact tests has been on the collection of 2 millimeters- and larger fragments resulting from impact test on the 56 kilogram-representative LEO (Low Earth Orbit) satellite referred to as DebriSat. To date we have recovered in excess of 115,000 fragments, 30,000 more than the prediction of 85,000 fragments from the existing model. We continue to collect fragments but have transitioned to the characterization phase of the post-impact activities. Since the start of the characterization phase, the focus has been to utilize automation to (i) expedite fragment characterization process and (ii) minimize human-in-the- loop. We have developed and implemented such automated processes; e.g., we have automated the data entry process to reduce operator errors during transcription of the measurement data. However, at all steps of the process, there is human oversight to ensure the integrity of the data. Additionally, we have developed and implemented repeatability and reproducibility tests to ensure that the instrumentation used in the characterization process is accurate and properly calibrated. In this paper, the implemented processes are described and preliminary results presented. Additionally, lessons learned from the implemented automations and their impacts on the integrity of the results are discussed

Epigenetic changes mediated by polycomb repressive complex 2 and E2a are associated with drug resistance in a mouse model of lymphoma

Background: The genetic origins of chemotherapy resistance are well established; however the role of epigenetics in drug resistance is less well understood To investigate mechanisms of drug resistance we performed systematic genetic epigenetic and transcriptomic analyses of an alkylating agent-sensitive murine lymphoma cell line and a series of resistant lines derived by drug dose escalation   Methods: Dose escalation of the alkylating agent mafosfamide was used to create a series of increasingly drugresistant mouse Burkitt's lymphoma cell lines Whole genome sequencing DNA microarrays reduced representation bisulfite sequencing and chromatin immunoprecipitation sequencing were used to identify alterations in DNA sequence mRNA expression CpG methylation and H3K27me3 occupancy respectively that were associated with increased resistance   Results: Our data suggest that acquired resistance cannot be explained by genetic alterations Based on integration of transcriptional profiles with transcription factor binding data we hypothesize that resistance is driven by epigenetic plasticity We observed that the resistant cells had H3K27me3 and DNA methylation profiles distinct from those of the parental lines Moreover we observed DNA methylation changes in the promoters of genes regulated by E2a and members of the polycomb repressor complex 2 (PRC2) and differentially expressed genes were enriched for targets of E2a The integrative analysis considering H3K27me3 further supported a role for PRC2 in mediating resistance By integrating our results with data from the Immunological Genome Project (Immgenorg) we showed that these transcriptional changes track the B-cell maturation axis   Conclusions: Our data suggest a novel mechanism of drug resistance in which E2a and PRC2 drive changes in the B-cell epigenome; these alterations attenuate alkylating agent treatment-induced apoptosi

Characterizing DebriSat Fragments -- Preliminary Results

No abstract availabl

Chiral Polymerization in Open Systems From Chiral-Selective Reaction Rates

We investigate the possibility that prebiotic homochirality can be achieved exclusively through chiral-selective reaction rate parameters without any other explicit mechanism for chiral bias. Specifically, we examine an open network of polymerization reactions, where the reaction rates can have chiral-selective values. The reactions are neither autocatalytic nor do they contain explicit enantiomeric cross-inhibition terms. We are thus investigating how rare a set of chiral-selective reaction rates needs to be in order to generate a reasonable amount of chiral bias. We quantify our results adopting a statistical approach: varying both the mean value and the rms dispersion of the relevant reaction rates, we show that moderate to high levels of chiral excess can be achieved with fairly small chiral bias, below 10%. Considering the various unknowns related to prebiotic chemical networks in early Earth and the dependence of reaction rates to environmental properties such as temperature and pressure variations, we argue that homochirality could have been achieved from moderate amounts of chiral selectivity in the reaction rates.Comment: 15 pages, 6 figures, accepted for publication in Origins of Life and Evolution of Biosphere