Optimizing the physical properties of collagen/hyaluronan hydrogels by inhibition of polyionic complexes formation at pH close to the collagen isoelectric point.

Collagen/hyaluronan hydrogels with physical properties well suited for biomedical applications are challenging to synthesize due to the formation of polyionic complexes (PICs). A systematic physicochemical study was thus performed to determine novel conditions to inhibit the formation of collagen/hyaluronan PICs and obtain composite hydrogels with high physical properties. Using a range of pH from 1 to 5.5 and the addition of NaCl, type I collagen and tyramine-substituted hyaluronic acid (THA) solutions were mixed and analyzed by cryo-scanning electron microscopy and ATR-FTIR. PIC formation was inhibited at pH 1 without salt and at pH 2.5 and 5.5 in the presence of 400 mM NaCl. Interestingly, collagen fibrils were observed in solution at pH 5.5 before mixing with THA. After collagen gelling by pH increase, a homogeneous hydrogel consisting of collagen fibrils was only observed when PICs were inhibited. Then, the THA gelling performed by photo-crosslinking increased the rheological properties by four when hydrogels were formed with collagen/THA mixtures at pH 1 or 5.5 with salt. Taken together, these results show that a pH of 5.5, close to the collagen isoelectric point, enables the formation of collagen fibrils in solution, inhibits the PICs formation, and allows the formation of homogenous collagen/THA composite hydrogels compatible with cell survival.

Combining biomimetic collagen/hyaluronan hydrogels with discogenic growth factors promotes mesenchymal stroma cell differentiation into Nucleus Pulposus like cells.

Based on stem cell injection into degenerated Nucleus Pulposus (NP), novel treatments for intervertebral disc (IVD) regeneration were disappointing because of cell leakage or inappropriate cell differentiation. In this study, we hypothesized that mesenchymal stromal cells encapsulated within injectable hydrogels possessing adequate physico-chemical properties would differentiate into NP like cells. Composite hydrogels consisting of type I collagen and tyramine-substituted hyaluronic acid (THA) were prepared to mimic the NP physico-chemical properties. Human bone marrow derived mesenchymal stromal cells (BM-MSCs) were encapsulated within hydrogels and cultivated in proliferation medium (supplemented with 10% fetal bovine serum) or differentiation medium (supplemented with GDF5 and TGFß1) over 28 days. Unlike pure collagen, collagen/THA composite hydrogels were stable over 28 days in culture. In proliferation medium, the cell viability within pure collagen hydrogels was high, whereas that in composite and pure THA hydrogels was lower due to the weaker cell adhesion. Nonetheless, BM-MSCs proliferated in all hydrogels. In composite hydrogels, cells exhibited a rounded morphology similar to NP cells. The differentiation medium did not impact the hydrogel stability and cell morphology but negatively impacted the cell viability in pure collagen hydrogels. A high THA content within hydrogels promoted the gene expression of NP markers such as collagen II, aggrecan, SOX9 and cytokeratin 18 at day 28. The differentiation medium potentialized this effect with an earlier and higher expression of these NP markers. Taken together, these results show that the physico-chemical properties of collagen/THA composite hydrogels and GDF5/TGFß1 act in synergy to promote the differentiation of BM-MSCs into NP like cells.

Burnout syndrome in nursing residents in COVID-19 pandemic / Burnout syndrome in nursing residents in COVID-19 pandemic

Introduction: The incidence of Burnout Syndrome (BS) among nurses is higher. For this group, nursing residents undergo periodic assessments regarding compliance with the care workload in closed sectors, such as Intensive Care and Emergency Care, that put them at higher risk for the syndrome. Objective: Identify the prevalence and related factors for BS in nursing residents. Material and Methods: Quantitative, analytical, cross-sectional study with 106 nurses enrolled in the Residency program in Rio de Janeiro, Brazil, based on the following instruments: Maslach Burnout Inventory-General Survey Scale and an occupational sociodemographic questionnaire. Non-parametric statistical tests for independent samples were applied and Mann-Whitney test 15 was used for quantitative variables. Results: The results show that variable changes in relationships indicates stage 4 of the BS when compared to the other stages. For the other variables, there were no statistically significant differences. Discussion: Studies reveal that work-family balance is closely related to how job satisfaction is affected and mitigates the negative effects of BS. Conclusions: Consequences on relation patterns are among the most affected symptoms in the lives of nursing residents. This study is expected to contribute to raising awareness of the problem in question and to improve the quality of work life of resident nurses, detecting and preventing their illness.

Introducción: La incidencia del síndrome de burnout en profesionales de enfermería es mayor. Los residentes de enfermería se someten a evaluaciones periódicas sobre el cumplimiento de la carga de trabajo asistencial en servicios cerrados, como unidades de cuidados intensivos y urgencias, que les exponen a un mayor riesgo de padecer este síndrome. Objetivo: Identificar la prevalencia y factores relacionados del síndrome de burnout en residentes de enfermería. Materiales y métodos: Estudio cuantitativo, analítico y transversal que incluyó 106 enfermeros residentes matriculados en el programa de residencia en Río de Janeiro, Brasil, y empleó el Inventario de Burnout de Maslach - Encuesta General y un cuestionario sociodemográfico y ocupacional. Se aplicaron pruebas estadísticas no paramétricas para muestras independientes y se utilizó la prueba de Mann-Whitney para las variables cuantitativas. Resultados: Los resultados muestran que la variable "cambios en las relaciones" se encuentra en etapa 4 del síndrome de burnout en comparación con las demás etapas. En cuanto a las demás variables, no hubo diferencias estadísticamente significativas. Discusión: Los estudios revelan que el equilibrio trabajo-familia está estrechamente relacionado con el modo en que se ve afectada la satisfacción laboral y mitiga los efectos negativos del síndrome de burnout. Conclusiones: Las consecuencias en los patrones de relación se encuentran entre los síntomas más afectados en la vida de los residentes de enfermería. Se espera que este estudio contribuya a concientizar sobre el problema en cuestión y a mejorar la calidad de vida laboral de las enfermeras residentes, detectando y previniendo esta enfermedad.

Introdução: A incidência da Síndrome de Burnout (SB) entre os enfermeiros é maior. Para esse grupo, os residentes de enfermagem são submetidos a avaliações periódicas quanto ao cumprimento da carga horária de cuidados em setores fechados, como Terapia Intensiva e Emergência, o que os coloca em maior risco para a síndrome. Objetivo: Identificar a prevalência e os fatores relacionados à SB em residentes de enfermagem. Material e métodos: Estudo quantitativo, analítico, transversal com 106 enfermeiros matriculados no programa de Residência no Rio de Janeiro, Brasil, com base nos seguintes instrumentos: Maslach Burnout Inventory-General Survey Scale e um questionário sociodemográfico ocupacional. Foram aplicados testes estatísticos não paramétricos para amostras independentes e o teste de Mann-Whitney 15 foi usado para variáveis quantitativas. Resultados: Os resultados mostram que as mudanças variáveis nos relacionamentos indicam o estágio 4 do BS quando comparado com os outros estágios. Para as outras variáveis, não houve diferenças estatisticamente significativas. Discussão: Estudos revelam que o equilíbrio entre trabalho e família está intimamente relacionado à forma como a satisfação no trabalho é afetada e atenua os efeitos negativos da SB. Conclusões: As consequências nos padrões de relacionamento estão entre os sintomas mais afetados na vida dos residentes de enfermagem. Espera-se que este estudo contribua para aumentar a conscientização sobre o problema em questão e para melhorar a qualidade de vida profissional dos enfermeiros residentes, detectando e prevenindo suas doenças.

From byproduct to a functional ingredient: Camu-camu (Myrciaria dubia) seed extract as an antioxidant agent in a yogurt model.

This work aimed to characterize the phenolic composition and in vitro antioxidant and antiproliferative properties of lyophilized camu-camu (Myrciaria dubia) seed extract (LCE), and to assess the effects of LCE on the antioxidant and sensory traits of yogurt. The LCE contained 46.3% (wt/wt) total phenolic content; the main compounds quantified were vescalagin, castalagin, gallic acid, procyanidin A2, and (-)-epicatechin. The LCE had antioxidant activity, as measured by different chemical assays (2,2-diphenyl-1-picrylhydrazyl, Folin-Ciocalteu reducing capacity, total reducing capacity, ferric reducing antioxidant power, and Cu2+ chelating capacity), and inhibited the cell proliferation of HepG2 cells (human hepatoma carcinoma; IC50 = 1,116 µg/mL) and Caco-2 cells (human colorectal adenocarcinoma epithelial cells; IC50 = 608.5 µg/mL). In addition, LCE inhibited the in vitro activity of α-amylase, α-glucosidase, and angiotensin-converting enzyme, and protected DNA from peroxyl radical-induced scission. When added to yogurts, different concentrations of LCE (0, 0.25, 0.5, 0.75, and 1.0 g/100 g) increased the chemical antioxidant and reducing capacities. The camu-camu yogurt containing LCE at 0.25 g/100 g had an acceptance index of 84%, showing that camu-camu seed extract may be a potential ingredient for addition to yogurts.

Demographically diverse crowds are typically not much wiser than homogeneous crowds.

Averaging independent numerical judgments can be more accurate than the average individual judgment. This "wisdom of crowds" effect has been shown with large, diverse samples, but the layperson wishing to take advantage of this may only have access to the opinions of a small, more demographically homogeneous "convenience sample." How wise are homogeneous crowds relative to diverse crowds? In simulations and survey studies, we demonstrate three necessary conditions under which small socially diverse crowds can outperform socially homogeneous crowds: Social identity must predict judgment, the effect of social identity on judgment must be at least moderate in size, and the average estimates of the social groups in question must "bracket" the truth being judged. Seven survey studies suggest that these conditions are rarely met in real judgment tasks. Comparisons between the performances of diverse and homogeneous crowds further confirm that social diversity can make crowds wiser but typically by a very small margin.

Culture Changes How We Think About Thinking: From "Human Inference" to "Geography of Thought".

Cultural comparison has challenged people's assumptions of universality in psychology. It has also revealed that many questions and approaches in psychology are not culture-free, but reflect a distinctively Western analytic framework. In this framework, the world is assumed to operate by discernible and stable rules, contradiction is a problem to be resolved, and entities are viewed as relatively independent agents. Context and relationships between people and objects are relatively downplayed-or, when they are examined, are assumed to operate under parsimonious rules. Dialectical or holistic thinking, a framework more prevalent in East Asian societies, involves greater attention to context and relationships, assumptions of change rather than stasis, and acceptance of contradiction. Analytic thinking is useful for science and daily life. But sometimes dialectical thinking results in more accurate conclusions or pragmatically useful decisions than analytic thinking. Therefore, we propose that both dialectical and analytic thinking should be consciously adopted as tools in the "cognitive toolbox" of researchers and laypeople alike. In the present article, we review the cross-cultural work demonstrating the psychological differences that analytic versus dialectical thinking produce. We then consider the strengths of each type of thinking and how they may serve complementary functions for problem solving.

Culture and decision making.

The study of culture and decision making addresses variations in how and why people from different cultures sometimes tend to decide differently. This review is organized around what is intended to be a comprehensive analysis of the distinct fundamental questions that people must answer in the process of making virtually all real-life decisions. Our emphasis was on recent developments as well as identifying important yet neglected topics (e.g., how decision episodes get started-or not, and why some decisions are never implemented). Early as well as current efforts have focused mainly on East Asian and North American Caucasian cultures, with little treatment of other populations. In such studies, individualism and collectivism have been the dominant explanatory factors although related but distinct concepts such as "tightness" and "looseness" have been welcome additions to recent discussions. Throughout, the review emphasizes practical concerns, such as the challenges of intercultural learning and collaboration.