Household transmission of COVID-19 according to index case: children, parents, and healthcare workers.

The first SARS-CoV-2 intrafamilial transmission was investigated in China. We evaluated the dynamics of SARS-CoV-2 transmission in 242 individuals from 60 family clusters, including 30 healthcare workers (HCW) and 30 patients, in São Paulo city. Sixty index cases with COVID-19 were selected, being 30 HCW index cases from Hospital São Paulo (HSP) and its 93 household contacts and 30 index case patients from Hospital Infantil Sabará (HIS) and its 89 household contacts. Asymptomatic and symptomatic individuals participating were tested for COVID-19. The secondary attack rates in the family clusters of HCW and HIS patients were 37.63% and 68.54%, respectively. Considering all households, the transmission from adults to children was 55.4%, while the transmission from children to children was 37.5%. Children were more infected if the index case was an adult, suggesting that children were less competent to transmit. The average time for a household to be COVID-19 positive was 4 and 3 days for HCW and HIS patients. Although HCW have a higher risk of infection and social vulnerability, the secondary attack rate was lower than that observed for HIS patients, possibly because HCW are more aware of transmission risks than the general community.

Comparative analysis of the small and large intestines of Acará Geophagus brasiliensis (Quoy & Gaimard, 1824) (Pisces: Cichlidae).

Geophagus brasiliensis, popularly known as acará, is a common fish in lentic freshwater environments in South America. This species has a detritivorous-iliophagous or omnivorous feeding habit, with high food plasticity; however, there are no studies describing its intestinal tract histologically. Therefore, the present study analysed through histological and histochemical techniques the intestines of the acará. Adult specimens were collected with gillnets, anaesthetized and euthanized. Then, the fish were submitted to biometry and dissection to remove fragments of intestines. The samples were fixed in Bouin liquid for 12 hours and subjected to histological and histochemical techniques. Histologically, all samples of intestines were organized into four layers: mucosa, submucosa, muscular and serosa. The small intestine (foregut and midgut) was characterized by the presence of intestinal villi covered by simple prismatic epithelium with a striated border and goblet cells supported by the connective lamina propria. In the large intestine (hindgut), there was an absence of villi and an abundance of goblet cells. Positive reaction to Periodic Acid-Schiff (PAS) and Alcian Blue (AB) pH 2.5 reactions were detected in goblet cells, indicating the presence of mucosubstances. No lipids were detected in the intestine cells due to the negative reaction to the Sudan Black B. The results of the present study provide subsidies for a better understanding of the intestinal morphology of teleosts and provide valuable information for phylogenetic studies.

Nurse sharks, space rockets and cargo ships: Metals and oxidative stress in a benthic, resident and large-sized mesopredator, Ginglymostoma cirratum.

It is widely recognized that apex predators, such as large sharks with highly migratory behavior, are particularly vulnerable to pollution, mainly due to biomagnification processes. However, in highly impacted areas, mesopredator sharks with resident behavior can be as vulnerable as apex sharks. In this context, this study evaluated cadmium (Cd), mercury (Hg), lead (Pb), and rubidium (Rb) concentrations, as well as the potentially protective effects of selenium (Se) and the behavior of two non-enzymatic biomarkers, metallothionein (MT) and reduced glutathione (GSH), employing the Atlantic nurse shark Ginglymostoma cirratum as a study model and compared the results with other resident benthic sharks, as well as highly mobile apex sharks. Muscle tissue samples from 28 nurse sharks opportunistically sampled from the Brazilian Amazon Coast were analyzed. Lower metal concentrations were observed for Pb, Rb and Se in the rainy season, while statistically significant correlations between metals were observed only between Hg and Cd and Pb and Se. Molar ratio calculations indicate potential protective Se effects against Pb, but not against Cd and Hg. No associations between MT and the determined metals were observed, indicating a lack of detoxification processes via the MT detoxification route. The same was noted for GSH, indicating no induction of this primary cellular antioxidant defense. Our results indicate that benthic/mesopredator sharks with resident behavior are, in fact, as impacted as highly mobile apex predators, with the traditional detoxification pathways seemingly inefficient for the investigated species. Moreover, considering the studied population and other literature data, pollution should be listed as a threat to the species in future risk assessments.

Negative metal bioaccumulation impacts on systemic shark health and homeostatic balance.

Contamination by metals is among the most pervasive anthropogenic threats to the environment. Despite the ecological importance of marine apex predators, the potential negative impacts of metal bioaccumulation and biomagnification on the health of higher trophic level species remains unclear. To date, most toxicology studies in sharks have focused on measuring metal concentrations in muscle tissues associating human consumption and food safety, without further investigating potential impacts on shark health. To help address this knowledge gap, the present study evaluated metal concentrations in the gills, muscle, liver and rectal gland of coastal sharks opportunistically sampled from Brazilian waters and tested for potential relationships between metal bioaccumulation and general shark health and homeostatic balance metrics. Results revealed high metal concentrations in all four tissue types, with levels varying in relation to size, sex, and life-stage. Metal concentrations were also associated with serum biomarkers (urea, lactate, ALT, triglycerides, alkaline phosphatase, and phosphorus) and body condition, suggesting potential negative impacts on organismal health.

Physiological Impairment as a Result of Bile Accumulation in an Apex Predator, the Tiger Shark (Galeocerdo cuvier Péron & Lesueur, 1822).

Physiological adaptations have evolved to help sharks face rapid periods of feast. Tiger sharks are generalist apex predators that rely on a high-lipid/protein diet. To achieve a satisfactory nutritional condition, proper lipid absorption and hepatic storage are needed. Bile secretion in sharks is low and sporadic but increases during short periods of fasting. The present study describes a physiological impairment caused by bile accumulation in juvenile tiger sharks, possibly due to prolonged fasting. These evidences suggest that, even though sharks have adaptations that prevent them from dying from starvation, alarming physiological alterations might occur. Future studies are needed to assess how such a condition can affect wild populations, as well as possible sublethal consequences that could impact their long-term survival.

A study of the modification of Y-TZP and resin cement with titanium dioxide nanotubes / Estudo da modificação de Y-TZP e cimento resinoso com nanotubos de dióxido de titânio

Titanium dioxide nanotubes (TiO2) have been applied to enhance the mechanical properties of dental materials. Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) has been increasingly used in dentistry. Aside from its optimal clinical results, Y-TZP is prone to failures related to insufficient thickness of the fixed prostheses connector and debonding due to its difficult adhesion. The purpose of this study is to evaluate the effect of the addition of different concentrations of TiO2 to YTZP in its mechanical properties and microstructure, and also to evaluate the influence of these nanotubes on the bond strength when added to the ceramic or to the resin cement. To evaluate that, the described purposes were divided in two different papers. Paper 1 describes the tests of biaxial flexural strength, fractography qualitative analysis in scanning electron microscopy (SEM), microstructure evaluation in field emission-SEM and X-ray diffraction. Groups evaluated were commercial YTZP (Ivoclar Vivadent) (ZC) and an experimental Y-TZP with different blends of nanotubes [0 (Z0), 1 (Z1), 2 (Z2), and 5% (Z5), in volume]. In paper 2 shear bond strength test is described. It was carried out with the following groups: commercial YTZP (Ivoclar Vivadent) (ZC) and an experimental Y-TZP with different blends of nanotubes [0 (Z0), 1 (Z1), 2 (Z2), and 5% (Z5), in volume] bonded to the resin cement Panavia F2.0; and commercial Y-TZP bonded to resin cement RelyX U200 added with different blends of nanotubes in two curing methods dual-cured [0 (DC), 0.3 (D03), 0.6 (D06) and 0.9% (D09) of nanotubes in weigth] or self-cured [0 (SC), 0.3 (S03), 0.6 (S06) and 0.9% (S09) of nanotubes in weigth]. Values of flexural strength and shear bond strength were subjected to ANOVA and Tukey (=0.05). Flexural strength values were also subjected to Weibull statistics. Grain sizes values were subjected to Kruskal-Wallis and Dunn tests (=0.05). The flexural strength results were: ZC 896.73±122.70; Z0 577.67±62.26; Z1 477.32±75.65; Z2 492.25±63.19; Z5 437.18±53.55. The Weibull modulus results found were: ZC 7.9; Z0 11.2, Z1 8.7; Z2 8.1; Z5 9.3. Results showed that experimental Y-TZP presented lower flexural strength values than commercial one, but the first presented better Weibull modulus (m). Experimental Y-TZP also presented good microstructure, comparable to commercial Y-TZP, with very similar grain sizes. Nanotubes addition to Y-TZP led to lower flexural strength, although higher m than commercial ceramic. Pores containing Ti were observed in Y-TZP as the nanotubes concentration raised. Shear bond strength results found were, from higher to lower values: Z5 6.46±3.36; DC 6.17±0.87; D03 5.74±1.70; S03 5.73±1.71; Z1 5.16±2.62; D06 4.82±1.06; D09 4.75±1.43; SC 4.73±1.43; S09 4.61±0.85; S06 4.51±1.87; ZC 3.70±1.82; Z0 -3.33±2.05; Z2 2.94±1.38. Shear bond strength was also influenced by nanotubes addition, either in the ceramic or in the cement, although not linearly. Y-TZP added of 5% of TiO2 nanotubes presented the highest bond strength, although with no significant difference from most groups. Group Z1 was probably the group that presented the best combination of flexural strength, m, microstructure and bond strength. More studies of other properties could be carried out with this group.(AU)

Nanotubos de dióxido de titânio (TiO2) tem sido utilizados para melhorar as propriedades mecânicas de materiais odontológicos. Zircônica tetragonal policristalina estabilizada por ítria (Y-TZP) tem sido amplamente utilizada na Odontologia. Apesar de seus excelentes resultados clínicos, a Y-TZP é suscetível a falhas relacionadas à espessura insuficiente do conector da prótese fixa e a soltura da restauração devido à adesão deficiente. O objetivo desse trabalho é avaliar o efeito da adição de diferentes concentrações de nanotubos de TiO2 à Y-TZP nas suas propriedades mecânicas e microestrutura, além de avaliar a influência na resistência de união da adição desses nanotubos na cerâmica ou no cimento resinoso. Para isso, os objetivos descritos foram divididos em dois artigos diferentes. O artigo 1 descreve os testes de resistência flexural biaxial, análise fractográfica qualitativa em microscopia eletrônica de varredura (MEV), avaliação de microestrutura em MEV de emissão de campo e difração de raios-X. Os grupos avaliados foram: Y-TZP comercial (Ivoclar Vivadent) (ZC) e Y-TZP experimental com diferentes concentrações de nanotubos [0 (Z0), 1 (Z1), 2 (Z2), e 5% (Z5), em volume]. No artigo 2 está descrito o teste de resistência ao cisalhamento que foi realizado com os seguintes grupos: Y-TZP comercial (ZC) e Y-TZP experimental com diferentes concentrações de nanotubos [0 (Z0), 1 (Z1), 2 (Z2), e 5% (Z5), em volume] aderidas ao cimento Panavia F2.0; e Y-TZP comercial aderida ao cimento resinoso RelyX U200 com adição de diferentes concentrações de nanotubos em dois métodos de polimerização: dual [0 (DC), 0,3 (D03), 0,6 (D06) e 0,9% (D09) de nanotubos em peso] ou auto [0 (SC), 0,3 (S03), 0,6 (S06) e 0,9% (S09) de nanotubos em peso]. Os valores de resistência flexural e resistência ao cisalhamento foram submetidos aos testes de ANOVA e Tukey (=0,05). A resistência flexural também passou por análise de Weibull. Os valores de tamanho de grãos foram submetidos a testes de Kruskal-Wallis e Dunn (=0,05). Os resultados de resistência flexural encontrados foram: ZC 896,73±122,70; Z0 577,67±62,26; Z1 477,32±75,65; Z2 492,25±63,19; Z5 437,18±53,55. Os resultados de módulo de Weibull encontrados foram: ZC - 7,9; Z0 - 11,2; Z1 - 8,7; Z2 - 8,1; Z5 - 9,3. Os resultados mostraram que a Y-TZP experimental apresentou menores valores de resistência flexural do que a cerâmica comercial, mas a primeira apresentou maior módulo de Weibull (m). A Y-TZP experimental apresentou boa microestrutura, comparável à Y-TZP comercial, com tamanhos de grão muito semelhantes. A adição de nanotubos à Y-TZP levou a menor resistência flexural, porém maior m que a cerâmica comercial. Poros contendo Ti foram observados na Y-TZP conforme a concentração de nanotubos aumentou. Os resultados de resistência ao cisalhamento foram, do maior para o menor: Z5 - 6,46±3,36; DC - 6,17±0,87; D03 - 5,74±1,70; S03 - 5,73±1,71; Z1 - 5,16±2,62; D06 - 4,82±1,06; D09 - 4,75±1,43; SC - 4,73±1,43; S09 - 4,61±0,85; S06 - 4,51±1,87; ZC - 3,70±1,82; Z0 - 3,33±2,05; Z2 - 2,94±1,38. A resistência ao cisalhamento também foi influenciada pela adição de nanotubos, tanto na cerâmica quanto no cimento, porém não linearmente. A Y-TZP adicionada de 5% de nanotubos de TiO2 apresentou maior resistência de união, porém sem diferença estatística da maioria dos grupos. O grupo Z1 foi provavelmente o grupo que apresentou a melhor combinação de resistência flexural, m, microestrutura e resistência de união. Mais estudos de outras propriedades podem ser realizados com o mesmo.(AU)

Perfil biopsicossocial de pacientes renais crônicos em tratamento hemodialítico / Biopsychological and social profile of chronic renal patients in hemodialysis

Objetivo: Traçar o perfil biopsicosocial de renais crônicos em terapia hemodialítica. Métodos: Em 40 renais crônicos sob tratamento hemodialítico regular na Unidade de Terapia Renal Substitutiva da Irmandade do Hospital da Santa Casa de Poços de Caldas, foi aplicado o questionário SF-36, utilizado para medida da qualidade de vida em oito dimensões; coletados dados sócio-demográficos, clínicos e nutricionais. Os resultados foram apresentados na forma de análise descritiva. Resultados: A amostra foi constituída por 16 mulheres (40

), e 24 homens (60

Psicologia existencial-fenomenologica: o saber filosofico e a producao cientifica

Na tentativa de compreender o lugar epistemologico da Psicologia Existencial-Fenomenologica, torna-se necessaria a contextualizacao filosofica dos pressuspostos que embassam a sua visao de homem e de mundo e que repercutem em seu fazer cientifico. Neste sentido, tenta-se articular o entendimento do Existencialismo e da Fenomenologia com a Psicologia. Ressalta-se o envolvimento intersubjetivo do pscologo existencial-fenomenologico com sujeito de seus estudos. A partir disso, conclui-se o carater processual destes estudos, visto que o saber filosofico lhes garante uma producao cientifica voltada a uma constante abertura ao devir dos significados do existir humano.