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CONTEXT: Ammonium Tutton salts have been widely studied in recent years due to their thermostructural properties, which make them promising compounds for application in thermochemical energy storage devices. In this work, a detailed experimental study of the Tutton salt with the formula (NH4)2Zn(SO4)2(H2O)6 is carried out. Its structural, vibrational, and thermal properties are analyzed and discussed. Powder X-ray diffraction (PXRD) studies confirm that the compound crystallizes in a structure of a Tutton salt, with monoclinic symmetry and P21/a space group. The Hirshfeld surface analysis results indicate that the main contacts stabilizing the material crystal lattice are H···O/O···H, H···H, and O···O. In addition, a typical behavior of an insulating material is confirmed based on the electronic bandgap calculated from the band structure and experimental absorption coefficient. The Raman and infrared spectra calculated using DFT are in a good agreement with the respective experimental spectroscopic results. Thermal analysis in the range from 300 to 773 K reveals one exothermic and several endothermic events that are investigated using PXRD measurements as a function of temperature. With increasing temperature, two new structural phases are identified, one of which is resolved using the Le Bail method. Our findings suggest that the salt (NH4)2Zn(SO4)2(H2O)6 is a promising thermochemical material suitable for the development of heat storage systems, due to its low dehydration temperature (≈ 330 K), high enthalpy of dehydration (122.43 kJ/mol of H2O), and hydration after 24 h. METHODS: Computational studies using Hirshfeld surfaces and void analysis are conducted to identify and quantify the intermolecular contacts occurring in the crystal structure. Furthermore, geometry optimization calculations are performed based on density functional theory (DFT) using the PBE functional and norm-conserving pseudopotentials implemented in the Cambridge Serial Total Energy Package (CASTEP). The primitive unit cell optimization was conducted using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm. The electronic properties of band structure and density of states, and vibrational modes of the optimized crystal lattice are calculated and analyzed.
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BACKGROUND: Multi-organ damage is a common feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, going beyond the initially observed severe pneumonia. Evidence that the testis is also compromised is growing. OBJECTIVE: To describe the pathological findings in testes from fatal cases of COVID-19, including the detection of viral particles and antigens, and inflammatory cell subsets. MATERIALS AND METHODS: Postmortem testicular samples were obtained by percutaneous puncture from 11 deceased men and examined by reverse-transcription polymerase chain reaction (RT-PCR) for RNA detection and by light and electron microscopy (EM) for SARS-CoV-2. Immunohistochemistry (IHC) for the SARS-CoV-2 N-protein and lymphocytic and histiocytic markers was also performed. RESULTS: Eight patients had mild interstitial orchitis, composed mainly of CD68+ and TCD8+ cells. Fibrin thrombi were detected in five cases. All cases presented congestion, interstitial edema, thickening of the tubular basal membrane, decreased Leydig and Sertoli cells with reduced spermatogenesis, and strong expression of vascular cell adhesion molecule (VCAM) in vessels. IHC detected SARS-Cov-2 antigen in Leydig cells, Sertoli cells, spermatogonia, and fibroblasts in all cases. EM detected viral particles in the cytoplasm of fibroblasts, endothelium, Sertoli and Leydig cells, spermatids, and epithelial cells of the rete testis in four cases, while RT-PCR detected SARS-CoV-2 RNA in three cases. DISCUSSION AND CONCLUSION: The COVID-19-associated testicular lesion revealed a combination of orchitis, vascular changes, basal membrane thickening, Leydig and Sertoli cell scarcity, and reduced spermatogenesis associated with SARS-CoV-2 local infection that may impair hormonal function and fertility in men.
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COVID-19/complicaciones , Orquitis/patología , Orquitis/virología , Testículo/patología , Adulto , Anciano , Anciano de 80 o más Años , Autopsia , Humanos , Masculino , Persona de Mediana Edad , SARS-CoV-2RESUMEN
BACKGROUND: Social detachment to prevent the spread of the COVID-19 pandemics in the year 2020 can significantly contribute to the physical inactivity of citizens worldwide. The study aimed to analyze the level of physical activity by identifying the training methods used during the social isolation resulting from the COVID-19 pandemic. METHODS: Sixty-eight Brazilian athletes (both sexes, 14.7±1.68 years) answered and adapted the International Physical Activity Questionnaire (I-PAQ) through an online platform. Participants were asked to report their level of physical activity before and during the period of social distance. RESULTS: According to our results, 67.7% of the interviewed athletes said they were able to adapt their sports training to the isolation environment under the guidance of a distance physical education professional. Only 4.38% of the sample was not training under such supervision and, therefore, inactive. Among the activities performed in the isolation environment, calisthenics was the primary practice (effect size: ƒ2=0.50, P<0.0001) and the sport practiced at home was the secondary practice (effect size: ƒ2=0.27, P=0.004). During the pandemic, the training hours of athletes reduced significantly from ~3h to ~1h per day (effect size: 1.74, P<0.0001), as well as the perceived intensity decreased from "high" to "moderate" (effect size: 1.38, P<0.0001). The weekly training frequency decreased from ~6 to 7 days to ~3 to 5 days (effect size: 0.40, P=0.03). CONCLUSIONS: Despite the social distance and the reduced pace of training, the young Brazilian athletes analyzed managed to remain physically active during the COVID-19 pandemic.
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COVID-19 , Atletas , Brasil/epidemiología , COVID-19/epidemiología , Ejercicio Físico , Femenino , Humanos , Masculino , Pandemias , Aislamiento SocialRESUMEN
AIMS: Brazil ranks high in the number of coronavirus disease 19 (COVID-19) cases and the COVID-19 mortality rate. In this context, autopsies are important to confirm the disease, determine associated conditions, and study the pathophysiology of this novel disease. The aim of this study was to assess the systemic involvement of COVID-19. In order to follow biosafety recommendations, we used ultrasound-guided minimally invasive autopsy (MIA-US), and we present the results of 10 initial autopsies. METHODS AND RESULTS: We used MIA-US for tissue sampling of the lungs, liver, heart, kidneys, spleen, brain, skin, skeletal muscle and testis for histology, and reverse transcription polymerase chain reaction to detect severe acute respiratory syndrome coronavirus 2 RNA. All patients showed exudative/proliferative diffuse alveolar damage. There were intense pleomorphic cytopathic effects on the respiratory epithelium, including airway and alveolar cells. Fibrinous thrombi in alveolar arterioles were present in eight patients, and all patients showed a high density of alveolar megakaryocytes. Small thrombi were less frequently observed in the glomeruli, spleen, heart, dermis, testis, and liver sinusoids. The main systemic findings were associated with comorbidities, age, and sepsis, in addition to possible tissue damage due to the viral infection, such as myositis, dermatitis, myocarditis, and orchitis. CONCLUSIONS: MIA-US is safe and effective for the study of severe COVID-19. Our findings show that COVID-19 is a systemic disease causing major events in the lungs and with involvement of various organs and tissues. Pulmonary changes result from severe epithelial injury and microthrombotic vascular phenomena. These findings indicate that both epithelial and vascular injury should be addressed in therapeutic approaches.
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Autopsia/métodos , COVID-19/patología , Adulto , Anciano , Anciano de 80 o más Años , Brasil , Femenino , Humanos , Masculino , Persona de Mediana Edad , SARS-CoV-2 , UltrasonografíaRESUMEN
Bionanocomposite films have been prepared by casting an aqueous suspension of acetylated starch (ST) and poly(vinyl alcohol) (PVA) loaded with graphene oxide (GO). A photochemical and reagentless method has been successfully performed to convert the GO phase into reduced graphene oxide (RGO). The nanocomposites have displayed improved thermal and electrical properties when the amount of the GO phase is increased and properly converted to RGO. The molecular-level interactions between components are mainly hydrogen-bonding type according to attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and Raman spectroscopies, as well as thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) has confirmed the effective mixing between the GO and the ST-PVA matrix. The thermal diffusivity and electrical resistivity of ST-GO nanocomposites have increased one order and decreased two orders of magnitude, respectively, after the photochemical treatment. These findings have confirmed the effectiveness of the proposed approach to produce starch-based nanocomposites with improved thermal and electrical properties.
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Grafito/química , Nanocompuestos/química , Almidón/química , Acetilación , Impedancia Eléctrica , Calor , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Electrónica de Rastreo , Nanocompuestos/efectos de la radiación , Procesos Fotoquímicos , Alcohol Polivinílico/química , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Almidón/efectos de la radiación , Termogravimetría , Rayos UltravioletaRESUMEN
BACKGROUND: Hypopigmentation in hypopigmented mycosis fungoides (MF) is thought to result from the action of CD8+ cells on melanocytes. Here, we investigated the immunophenotype and melanocytic markers in hypopigmented MF lesions. METHODS: Specimens of hypopigmented lesions and normal skin from 18 patients with hypopigmented MF and specimens of non-hypopigmented lesions from 8 patients with classic/conventional MF were subjected to neoplastic immunophenotyping and melanocyte immunostaining with Melan-A, tyrosinase, stem cell factor receptor (CD117) and microphthalmia-associated transcription factor (MiTF). RESULTS: The CD8+ immunophenotype was more common in hypopigmented MF lesions (14/18) than in conventional MF lesions (1/8, p = 0.0033). There was a main effect of specimen type (hypopigmented MF lesion, hypopigmented MF normal skin, conventional MF lesion) on the number of melanocytes stained with Melan-A (median number/mm basal membrane, 1.97 vs. 4.77 vs. 5.42, respectively, p = 0.0046), tyrosinase (2.19 vs. 4.02 vs. 5.26, p = 0.0114), CD117 (4.29 vs. 7.81 vs. 5.45, p = 0.0064), and MiTF (2.75 vs. 4.43 vs. 4.98, p = 0.005). CONCLUSIONS: These results confirm previous findings of fewer melanocytes and CD117-positive melanocytes in hypopigmented MF and showed reduced MiTF identification, which is crucial for the function and survival of melanocytes. Thus cytotoxic CD8+ cell action may determine CD117/MiTF dysfunction, causing hypopigmentation.
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Hipopigmentación , Melanocitos/patología , Micosis Fungoide , Neoplasias Cutáneas , Adulto , Anciano , Estudios Transversales , Femenino , Humanos , Hipopigmentación/metabolismo , Hipopigmentación/patología , Masculino , Persona de Mediana Edad , Micosis Fungoide/metabolismo , Micosis Fungoide/patología , Estudios Retrospectivos , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patologíaRESUMEN
INTRODUCTION: Airway dysfunction in patients with the Acute Respiratory Distress Syndrome (ARDS) is evidenced by expiratory flow limitation and dynamic hyperinflation. These functional alterations have been attributed to closure/obstruction of small airways. Airway morphological changes have been reported in experimental models of acute lung injury, characterized by epithelial necrosis and denudation in distal airways. To date, however, no study has focused on the morphological airway changes in lungs from human subjects with ARDS. The aim of this study is to evaluate structural and inflammatory changes in distal airways in ARDS patients. METHODS: We retrospectively studied autopsy lung tissue from subjects who died with ARDS and from control subjects who died of non pulmonary causes. Using image analysis, we quantified the extension of epithelial changes (normal, abnormal and denudated epithelium expressed as percentages of the total epithelium length), bronchiolar inflammation, airway wall thickness, and extracellular matrix (ECM) protein content in distal airways. The Student's t-test or the Mann-Whitney test was used to compare data between the ARDS and control groups. Bonferroni adjustments were used for multiple tests. The association between morphological and clinical data was analyzed by Pearson rank test. RESULTS: Thirty-one ARDS patients (A: PaO2/FiO2 ≤200, 45 ± 14 years, 16 males) and 11 controls (C: 52 ± 16 years, 7 males) were included in the study. ARDS airways showed a shorter extension of normal epithelium (A:32.9 ± 27.2%, C:76.7 ± 32.7%, P < 0.001), a larger extension of epithelium denudation (A:52.6 ± 35.2%, C:21.8 ± 32.1%, P < 0.01), increased airway inflammation (A:1(3), C:0(1), P = 0.03), higher airway wall thickness (A:138.7 ± 54.3 µm, C:86.4 ± 33.3 µm, P < 0.01), and higher airway content of collagen I, fibronectin, versican and matrix metalloproteinase-9 (MMP-9) compared to controls (P ≤0.03). The extension of normal epithelium showed a positive correlation with PaO2/FiO2 (r2 = 0.34; P = 0.02) and a negative correlation with plateau pressure (r2 = 0.27; P = 0.04). The extension of denuded epithelium showed a negative correlation with PaO2/FiO2 (r2 = 0.27; P = 0.04). CONCLUSIONS: Structural changes in small airways of patients with ARDS were characterized by epithelial denudation, inflammation and airway wall thickening with ECM remodeling. These changes are likely to contribute to functional airway changes in patients with ARDS.
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Remodelación de las Vías Aéreas (Respiratorias)/fisiología , Pulmón/patología , Síndrome de Dificultad Respiratoria/fisiopatología , Adulto , Autopsia , Estudios de Casos y Controles , Matriz Extracelular/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
RATIONALE: There are no reports of the systemic human pathology of the novel swine H1N1 influenza (S-OIV) infection. OBJECTIVES: The autopsy findings of 21 Brazilian patients with confirmed S-OIV infection are presented. These patients died in the winter of the southern hemisphere 2009 pandemic, with acute respiratory failure. METHODS: Lung tissue was submitted to virologic and bacteriologic analysis with real-time reverse transcriptase polymerase chain reaction and electron microscopy. Expression of toll-like receptor (TLR)-3, IFN-gamma, tumor necrosis factor-alpha, CD8(+) T cells and granzyme B(+) cells in the lungs was investigated by immunohistochemistry. MEASUREMENTS AND MAIN RESULTS: Patients were aged from 1 to 68 years (72% between 30 and 59 yr) and 12 were male. Sixteen patients had preexisting medical conditions. Diffuse alveolar damage was present in 20 individuals. In six patients, diffuse alveolar damage was associated with necrotizing bronchiolitis and in five with extensive hemorrhage. There was also a cytopathic effect in the bronchial and alveolar epithelial cells, as well as necrosis, epithelial hyperplasia, and squamous metaplasia of the large airways. There was marked expression of TLR-3 and IFN-gamma and a large number of CD8(+) T cells and granzyme B(+) cells within the lung tissue. Changes in other organs were mainly secondary to multiple organ failure. CONCLUSIONS: Autopsies have shown that the main pathological changes associated with S-OIV infection are localized to the lungs, where three distinct histological patterns can be identified. We also show evidence of ongoing pulmonary aberrant immune response. Our results reinforce the usefulness of autopsy in increasing the understanding of the novel human influenza A (H1N1) infection.
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Bronquiolitis Viral/patología , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana/patología , Alveolos Pulmonares/patología , Adolescente , Anciano , Autopsia , Niño , Preescolar , Femenino , Humanos , Lactante , Subtipo H1N1 del Virus de la Influenza A/inmunología , Gripe Humana/inmunología , Macrófagos Alveolares/inmunología , Masculino , Persona de Mediana Edad , Alveolos Pulmonares/inmunología , Adulto JovenRESUMEN
BACKGROUND: Structural and inflammatory changes in asthma involve both the large and small airways, with involvement of the distal lung being related to disease severity. We have previously shown that changes in the extracellular matrix (ECM) composition of the distal lung are associated with loss of alveolar attachments in patients with fatal asthma. However, major ECM elements, such as collagen I and fibronectin and their regulators, have not been addressed at the distal level. OBJECTIVE: We sought to evaluate ECM remodeling in the distal lungs of asthmatic patients. METHODS: Using immunohistochemistry and image analysis, we determined the content of collagen I and III, fibronectin, and matrix metalloproteinases (MMPs) 1, 2, and 9 and tissue inhibitors of metalloproteinase (TIMPs) 1 and 2 in the large and small airways and lung parenchyma of 24 patients with fatal asthma and compared the results with those of 11 nonasthmatic control subjects. Protein content was defined as the area of positive staining divided by basement membrane or septum length. RESULTS: We observed increased collagen I and decreased collagen III content in the small airways of asthmatic patients compared with that seen in control subjects. Greater fibronectin and MMP-1, MMP-2, and MMP-9 content was observed at the outer area of the small airways in asthmatic patients. MMP content was also increased in the peribronchiolar parenchyma in asthmatic patients. In contrast, TIMP expression was only increased in the large airways of asthmatic patients compared with that seen in control subjects. CONCLUSIONS: The outer area of the small airways is a major site of ECM remodeling in fatal asthma, potentially contributing to functional changes and the loss of airway-parenchyma interdependence observed in patients with fatal asthma.