Effect of synthesis temperature on crystallinity, morphology and cell viability of nanostructured hydroxyapatite via wet chemical precipitation method: Effect of temperature on hydroxyapatite properties

Hydroxyapatite (HA) is the main natural mineral constituent of bones and is a good alternative for biomedical applications because it is osteoconductive, non-allergenic, and non-carcinogenic, which ensures high biocompatibility. A commonly used method for obtaining hydroxyapatite is the wet route, which is simple and low-cost, produces only water as a final residue, and provides HA with a crystallinity comparable to that of bone tissue, which favors its biocompatibility. Therefore, the objective of this work is to synthesize hydroxyapatite via the wet chemical precipitation method at different temperatures (4°C, 30°C, 50°C, or 70°C) to observe the influence of temperature on crystallinity, morphology, and cytotoxicity. The results of X-ray diffraction show that all syntheses resulted in pure hydroxyapatite, while increasing the temperature led to higher crystallinity (10.6% to 56.2%) and the crystal size was slightly affected. The increase in temperature changed the particle shape from irregular to needle-like. Cell viability was tested by PicoGreen® in VERO cells for samples at concentrations of 30 and 300µg/mL, and the samples synthesized at 4°C, with lower crystallinity, caused less DNA damage to cells compared to the negative control. &nbsp

Procedimentos e percepções de profissionais e grupos atuantes em mercados de planos de saúde no Brasil Procedures and perceptions of professionals and groups acting in the Brazilian health plan market

O objetivo do estudo é analisar o modo como, no Brasil, operadoras de planos e seguros de saúde, serviços hospitalares e médicos organizam o acesso aos serviços de saúde, e que mecanismos utilizam para economia de custos e de decisões. A análise faz uso da literatura de regulação em saúde e da estratégia do managed care. A partir de uma seleção intencional de operadoras baseada em número de beneficiários, modalidade organizacional e abrangência geográfica, foram selecionadas amostras probabilísticas de médicos e de serviços hospitalares. Os dados foram obtidos através de questionários com representantes das operadoras, médicos e hospitais a elas credenciados. Os resultados sugerem que as relações entre operadoras, médicos e hospitais se estabeleceram em bases herdadas do antigo sistema previdenciário, com pagamento predominante de serviços por tabelas fixas e contas abertas. Mecanismos mais complexos de financiamento, de compartilhamento de riscos e de busca pela eficiência são pouco experimentados. São frágeis os mecanismos de redução de agravos, assim como os incentivos ao uso adequado das tecnologias. Fatores moderadores de consumo ou barreiras de acesso são o meio mais comum de controle de custos. Pode-se concluir que a agenda do managed care é incipiente no caso brasileiro.<br>This study analyzes the mechanisms used in Brazil by health plan and insurance operators, hospitals and physicians for organizing the access to health care services and their strategies towards cost reduction and decision-making. The study is based on the literature about regulation of the health services, with special focus on micro-management and managed care. From an intentional sample of health care organizations selected according to the number of beneficiaries, organizational modality and geographic criteria we selected probabilistic samples of doctors and hospital services. Data were collected through questionnaires applied to key informants from health care operators and affiliated doctors and hospitals. Results suggest that the relationships between health care organizations, physicians and hospitals follow basically patterns inherited from the former social security system, mainly with fixed pricing and open account payments. More complex financing mechanisms, risk sharing and efficiency strategies are of minor interest. Mechanisms for risk reduction and encouragement of adequate use of technologies are weak. Cost control is mainly based on co-payment and barriers to access to the services. We conclude that in Brazil managed care is still in its beginning

Educação escolar e resiliência: política de educação e a prática docente em meios adversos Educación escolar y resiliencia: política de educación y la práctica docente en medios adversos School education and resilience: the practice of teaching in media adverse

Este artigo se constitui num ensaio teórico construído a partir de uma revisão de literatura. Tem como objetivo discutir a questão da resiliência na educação escolar. Busca-se compreender o significado do termo resiliência e como esse conceito está adequado à figura do professor que, ao mesmo tempo viabiliza práticas e atitudes construtivas dos alunos, frente aos problemas do cotidiano da escola. A pesquisa da literatura sobre o assunto ocorreu nas bases de dados Medline, Google Acadêmico, Scielo, Lilacs (BIREME) entre os anos de 2002 a 2008. Os estudos sobre a resiliência do professor se revelaram ainda raros, preliminares ou insuficientes. Eles mostram que a resiliência não é um atributo da pessoa, mas pode ser consolidada na ação docente, e que o ambiente resiliente da ação pedagógica cresce quando existe um suporte afetivo e emocional necessário para que as pessoas trabalhem em constante clima de aprendizagem.<br>Este artículo es un ensayo teórico construido a partir de una revisión bibliográfica. Plantea discutir el tema de la resiliencia en la educación escolar. Se trata de comprender el término resiliencia y cómo su concepto se ajusta a la figura del docente, al mismo tiempo que posibilita prácticas y actitudes constructivas de los alumnos frente a los problemas de la vida cotidiana escolar. La investigación bibliográfica se basó en los datos de Medline, Google Scholar, Scielo, Lilacs (BIREME) entre los años 2002 al 2008. Los estudios sobre la resiliencia del profesor resultaron raros, preliminares o insuficientes. Lo que muestra que la resiliencia no es un atributo personal, pero puede consolidarse en la acción docente y que el ambiente resiliente de la acción pedagógica crece cuando hay un apoyo afectivo y emocional necesario para trabajar en un constante clima de aprendizaje.<br>This paper is a theoretical essay constructed from a literature review. It aims to discuss the issue of resilience in school education. This article also searches to comprehend the meaning of the term resilience and how this concept fits the picture of the teacher at the same time provides practical and constructive attitudes of students, and the problems associated with the school routine. A search of literature on the subject occurred in the databases Medline, Google Scholar, Scielo, Lilacs (BIREME) between the years 2002 to 2008. Studies on the teacher's resilience proved to be still rare, preliminary or insufficient. The studies also show that being resilient is not an attribute of the person but can be consolidated in teaching activities and that resilient environment of pedagogical action grows when there is an affective and emotional support necessary for people to work in constant climate of learning

Comunidades "no sentido social da evangelização": CEBs, camponeses e quilombolas na Amazônia Oriental Brasileira

O estudo sobre novos movimentos eclesiais na Igreja Católica, desenvolvido na Amazônia Oriental brasileira, permite uma reflexão sobre a influência dessa Igreja em duas áreas rurais do estado do Pará: a Transamazônica e a microrregião de Tomé Açu. Em ambas, sua atuação, através das chamadas Comunidades Eclesiais de Base (CEBs), muito ativas, desempenha papel relevante entre as populações dessas áreas. O artigo se propõe a analisar a condição social dessas populações que, em função de suas vivências e práticas, incorporando criticamente a influência de agentes de pastoral, assumem novas identidades e novas práticas de natureza política e religiosa, antes não existentes em seu meio

Association between administration of IL-6 antagonists and mortality among patients hospitalized for COVID-19 : a meta-analysis

IMPORTANCE Clinical trials assessing the efficacy of IL-6 antagonists in patients hospitalized for COVID-19 have variously reported benefit, no effect, and harm. OBJECTIVE To estimate the association between administration of IL-6 antagonists compared with usual care or placebo and 28-day all-cause mortality and other outcomes. DATA SOURCES Trials were identified through systematic searches of electronic databases between October 2020 and January 2021. Searches were not restricted by trial status or language. Additional trials were identified through contact with experts. STUDY SELECTION Eligible trials randomly assigned patients hospitalized for COVID-19 to a group in whom IL-6 antagonists were administered and to a group in whom neither IL-6 antagonists nor any other immunomodulators except corticosteroids were administered. Among 72 potentially eligible trials, 27 (37.5%) met study selection criteria. DATA EXTRACTION AND SYNTHESIS In this prospectivemeta-analysis, risk of biaswas assessed using the Cochrane Risk of Bias Assessment Tool. Inconsistency among trial results was assessed using the I-2 statistic. The primary analysis was an inverse variance-weighted fixed-effects meta-analysis of odds ratios (ORs) for 28-day all-cause mortality. MAIN OUTCOMES AND MEASURES The primary outcome measurewas all-cause mortality at 28 days after randomization. There were 9 secondary outcomes including progression to invasive mechanical ventilation or death and risk of secondary infection by 28 days. RESULTS A total of 10 930 patients (median age, 61 years [range of medians, 52-68 years]; 3560 [33%] were women) participating in 27 trials were included. By 28 days, there were 1407 deaths among 6449 patients randomized to IL-6 antagonists and 1158 deaths among 4481 patients randomized to usual care or placebo (summary OR, 0.86 [95% CI, 0.79-0.95]; P =.003 based on a fixed-effects meta-analysis). This corresponds to an absolute mortality risk of 22% for IL-6 antagonists compared with an assumed mortality risk of 25% for usual care or placebo. The corresponding summary ORs were 0.83 (95% CI, 0.74-0.92; P <.001) for tocilizumab and 1.08 (95% CI, 0.86-1.36; P =.52) for sarilumab. The summary ORs for the association with mortality compared with usual care or placebo in those receiving corticosteroids were 0.77 (95% CI, 0.68-0.87) for tocilizumab and 0.92 (95% CI, 0.61-1.38) for sarilumab. The ORs for the association with progression to invasive mechanical ventilation or death, compared with usual care or placebo, were 0.77 (95% CI, 0.70-0.85) for all IL-6 antagonists, 0.74 (95% CI, 0.66-0.82) for tocilizumab, and 1.00 (95% CI, 0.74-1.34) for sarilumab. Secondary infections by 28 days occurred in 21.9% of patients treated with IL-6 antagonists vs 17.6% of patients treated with usual care or placebo (OR accounting for trial sample sizes, 0.99; 95% CI, 0.85-1.16). CONCLUSIONS AND RELEVANCE In this prospectivemeta-analysis of clinical trials of patients hospitalized for COVID-19, administration of IL-6 antagonists, compared with usual care or placebo, was associated with lower 28-day all-cause mortality