One-Pot Synthesis of Oxidation-Sensitive Supramolecular Gels and Vesicles

Polypeptide-based nanoparticles offer unique advantages from a nanomedicine perspective such as biocompatibility, biodegradability, and stimuli-responsive properties to (patho)physiological conditions. Conventionally, self-assembled polypeptide nanostructures are prepared by first synthesizing their constituent amphiphilic polypeptides followed by postpolymerization self-assembly. Herein, we describe the one-pot synthesis of oxidation-sensitive supramolecular micelles and vesicles. This was achieved by polymerization-induced self-assembly (PISA) of the N-carboxyanhydride (NCA) precursor of methionine using poly(ethylene oxide) as a stabilizing and hydrophilic block in dimethyl sulfoxide (DMSO). By adjusting the hydrophobic block length and concentration, we obtained a range of morphologies from spherical to wormlike micelles, to vesicles. Remarkably, the secondary structure of polypeptides greatly influenced the final morphology of the assemblies. Surprisingly, wormlike micellar morphologies were obtained for a wide range of methionine block lengths and solid contents, with spherical micelles restricted to very short hydrophobic lengths. Wormlike micelles further assembled into oxidation-sensitive, self-standing gels in the reaction pot. Both vesicles and wormlike micelles obtained using this method demonstrated to degrade under controlled oxidant conditions, which would expand their biomedical applications such as in sustained drug release or as cellular scaffolds in tissue engineering

Desafios do projeto transição produtiva e serviços ambientais na qualificação de políticas públicas voltadas ao setor rural.

Três medidas político-institucionais ocorridas no Brasil nas duas últimas décadas devem ser destacadas: (1) Lei 12.651/2012 (Novo Código Florestal), (2) Projeto de Lei (PL) 792/2007 (Serviços Ambientais) e (3) Lei 9.126/1995 (Taxa de Juros de Longo Prazo). Mas a falta de informações cientificamente validadas impede a operacionalização de incentivos econômicos para transição produtiva com pagamento de serviços ambientais. Nesse sentido, a Embrapa e entidades parceiras conceberam o Projeto Transição Produtiva e Serviços Ambientais, com o objetivo geral de "gerar e validar instrumentos e metodologias para apoiar políticas públicas de incentivo econômico a processos de transição produtiva de Sistemas Produtivos Integrados (SPIs) com capacidade de geração de renda e prestação de serviços ambientais em escala de paisagem rural". A fase I do projeto será executada entre 09/2013 e 09/2017, tendo como resultados esperados (1) validação científica de desenhos agronômicos de SPIs, (2) validação científica de coeficientes financeiros para potencializar adoção de SPIs via crédito rural, (3) validação científica de indicadores de serviços ambientais prestados e valoração de serviços ambientais por SPIs para viabilizar rebate ecológico no crédito rural e comercialização de produtos em mercados institucionais com preços diferenciados, (4) validação participativa de indicadores de serviços ambientais e de metodologia de certificação de serviços ambientais para atestar condicionalidades em políticas públicas e reduzir custos de transação do PSA, (5) análise comportamental sobre adoção de SPIs para subsidiar recomendações técnicas de TT e ATER e (6) disponibilização de banco de dados de acesso público

Risk factors for bronchiolitis hospitalization during the first year of life in a multicenter Italian birth cohort

BACKGROUND: Respiratory Syncytial Virus (RSV) is one of the main causes of respiratory infections during the first year of life. Very premature infants may contract more severe diseases and 'late preterm infants' may also be more susceptible to the infection. The aim of this study is to evaluate the risk factors for hospitalization during the first year of life in children born at different gestational ages in Italy. METHODS: A cohort of 33-34 weeks gestational age (wGA) newborns matched by sex and age with two cohort of newborns born at 35-37 wGA and > 37 wGA were enrolled in this study for a three-year period (2009-2012). Hospitalization for bronchiolitis (ICD-9 code 466.1) during the first year of life was assessed through phone interview at the end of the RSV season (November-March) and at the completion of the first year of life. RESULTS: The study enrolled 2314 newborns, of which 2210 (95.5 %) had a one year follow-up and were included in the analysis; 120 (5.4 %) were hospitalized during the first year of life for bronchiolitis. Children born at 33-34 wGA had a higher hospitalization rate compared to the two other groups. The multivariate analysis carried out on the entire population associated the following factors with higher rates for bronchiolitis hospitalization: male gender; prenatal treatment with corticosteroids; prenatal exposure to maternal smoking; singleton delivery; respiratory diseases in neonatal period; surfactant therapy; lack of breastfeeding; siblings <10 years old; living in crowded conditions and/or in unhealthy households and early exposure to the epidemic RSV season. When analysis was restricted to preterms born at 33-34 wGA the following variables were associated to higher rates of bronchiolitis hospitalization: male gender, prenatal exposure to maternal smoking, neonatal surfactant therapy, having siblings <10 years old, living in crowded conditions and being exposed to epidemic season during the first three months of life. CONCLUSION: Our study identified some prenatal, perinatal and postnatal conditions proving to be relevant and independent risk factors for hospitalization for bronchiolitis during the first year of life. The combination of these factors may lead to consider palivizumab prophylaxis in Italy

Composite Polymer Hydrogels with high and Reversible Elongation under Magnetic Stimuli

The field of soft actuators is dominated by elastomers that experience mechanical deformations in response to external stimuli. In this context, magnetic stimuli attract considerable interest because of their easy application, tunability, fast response, remote actuation, and safe penetration in biological environments. Since very recently, research interests in the field are being redirected towards hydrogels, which could virtually replace elastomers, overcoming their limitations and expanding the field of application of soft actuators. The mechanical actuation of hydrogels is a nascent field full of challenges, such as achieving reliable and significant responsiveness. Here we demonstrate that the combination of a physical polymer hydrogel with a dispersed phase consisting of clusters of magnetic particles, results in magnetic hydrogel composites that exhibit high and reversible elongation in response to magnetic stimuli. Our analyses show that this response is strongly dependent on the matrix elasticity, the concentration of magnetic particles, and the particle distribution within the network of polymer nanofibres. Our strategy for the maximization of the response of magnetic hydrogels should be a catalyst for the development of novel applications of composite hydrogels, such as a valve remotely actuated by a magnetic field that we also present here as a proof-of-concept. © 2021 The Author(s).Dr. Mariusz Barczak is acknowledged for help with SEM imaging of iron particles. Ms. Laura Quesada de la Torre is acknowledged for help with design of graphical abstract. This study was supported by project FIS2017-85954-R (Ministerio de Economía, Industria y Competitividad, MINECO, and Agencia Estatal de Investigación, AEI, Spain, cofunded by Fondo Europeo de Desarrollo Regional, FEDER, European Union ). CGV acknowledges financial support by Ministerio de Ciencia, Innovación y Universidades and University of Granada, Spain, for her FPU17/00491 grant. AZ thanks the Russian Science Foundation, project 20-12-00031, for the financial support. LRA thanks the Spanish State Research Agency (Spanish Ministry of Science and Innovation ) through Juan de la Cierva Incorporacion Fellowship ( IJC2018-037951-I ). Funding for open access charge: Universidad de Granada / CBUA

Demanda de mao-de-obra em quatro modelos de sistemas agroflorestais implantados em areas de pastagens abandonadas na Amazonia Ocidental.

Quantificacao de mao-de-obra e determinacao de seu custo para cada atividade desenvolvida nos sistemas agroflorestais (SAFs), buscando contribuir para a escolha de SAFs mais eficientes e viaveis aos pequenos produtores em terra firme no Estado do Amazona. Os custos, na fase de implantacao dos SAFs indicaram que a recuperacao de areas degradadas e' onerosa e que os produtores dedicados a essa atividade devem receber fomento adequado pelos servicos ambientais que prestam, ate que a atividade comece a ser sustentavel e dar retorno economico, que, nos modelos estudados, ocorreram em quatro anos. A diminuicao da demanda de mao-de-obra dos SAFs, apos o quarto ano, diminui os custos, o que permite aos produtores a realizacao de outras atividades, agregando valores a sua propriedade

Carbon nanomaterials for targeted cancer therapy drugs: a critical review.

Cancer represents one of the main causes of human death in developed countries. Most current therapies, unfortunately, carry a number of side effects, such as toxicity and damage to healthy cells, as well as the risk of resistance and recurrence. Therefore, cancer research is trying to develop therapeutic procedures with minimal negative consequences. The use of nanomaterial-based systems appears to be one of them. In recent years, great progress has been made in the field of possible use of nanomaterials with high potential in biomedical applications. Carbon nanomaterials, thanks to their unique physicochemical properties, are gaining more and more popularity in cancer therapy. They are valued especially for their ability to deliver drugs or small therapeutic molecules to these cells. Through surface functionalization, they can specifically target tumor tissues, increasing the therapeutic potential and significantly reducing the adverse effects of therapy. Their potential future use could, therefore, as vehicles for drug delivery. This review presents the latest findings of research studies using carbon nanomaterials in the treatment of various types of cancer. To carry out this study, different databases such as Web of Science, PubMed, MEDLINE and Google Scholar were employed. The findings of research studies chosen from more than 2000 viewed scientific publications from the last 15 years were compared

Graphene Photonics and Optoelectronics

The richness of optical and electronic properties of graphene attracts enormous interest. Graphene has high mobility and optical transparency, in addition to flexibility, robustness and environmental stability. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential to be in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, even in the absence of a bandgap, and the linear dispersion of the Dirac electrons enables ultra-wide-band tunability. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light emitting devices, to touch screens, photodetectors and ultrafast lasers. Here we review the state of the art in this emerging field.Comment: Review Nature Photonics, in pres

Latin American consumption of major food groups: Results from the ELANS study

Background The Latin American (LA) region is still facing an ongoing epidemiological transition and shows a complex public health scenario regarding non-communicable diseases (NCDs). A healthy diet and consumption of specific food groups may decrease the risk of NCDs, however there is a lack of dietary intake data in LA countries. Objective Provide updated data on the dietary intake of key science-based selected food groups related to NCDs risk in LA countries. Design ELANS (Latin American Study of Nutrition and Health) is a multicenter cross-sectional study assessing food consumption from an urban sample between15 to 65 years old from 8 LA countries (Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Peru, and Venezuela). Two 24-HR were obtained from 9, 218 individuals. The daily intake of 10 food groups related to NCDs risk (fruits; vegetables; legumes/beans; nuts and seeds; whole grains products; fish and seafood; yogurt; red meat; processed meats; sugar-sweetened beverages (ready-to-drink and homemade)) were assessed and compared to global recommendations. Results Only 7.2% of the overall sample reached WHO's recommendation for fruits and vegetables consumption (400 grams per day). Regarding the dietary patterns related to a reduced risk of NCDs, among the overall sample legumes and fruits were the food groups with closer intake to the recommendation, although much lower than expected (13.1% and 11.5%, respectively). Less than 3.5% of the sample met the optimal consumption level of vegetables, nuts, whole grains, fish and yogurt. Largest country-dependent differences in average daily consumption were found for legumes, nuts, fish, and yogurt. Mean consumption of SSB showed large differences between countries. Conclusion Diet intake quality is deficient for nutrient-dense food groups, suggesting a higher risk for NCDs in the urban LA region in upcoming decades. These data provide relevant and up-to-date information to take urgent public health actions to improve consumption of critically foods in order to prevent NCDs. Copyright

Seleção de indicadores de serviços ambientais no Projeto Transição Produtiva e Serviços Ambientais da Embrapa.

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Growth of large-area single- and bi-layer graphene by controlled carbon precipitation on polycrystalline Ni surfaces

We report graphene films composed mostly of one or two layers of graphene grown by controlled carbon precipitation on the surface of polycrystalline Ni thin films during atmospheric chemical vapor deposition(CVD). Controlling both the methane concentration during CVD and the substrate cooling rate during graphene growth can significantly improve the thickness uniformity. As a result, one- or two- layer graphene regions occupy up to 87% of the film area. Single layer coverage accounts for 5-11% of the overall film. These regions expand across multiple grain boundaries of the underlying polycrystalline Ni film. The number density of sites with multilayer graphene/graphite (>2 layers) is reduced as the cooling rate decreases. These films can also be transferred to other substrates and their sizes are only limited by the sizes of the Ni film and the CVD chamber. Here, we demonstrate the formation of films as large as 1 in2. These findings represent an important step towards the fabrication of large-scale high-quality graphene samples