Nível tecnológico e emissão de poluentes: uma análise empírica a partir da curva de kuznets ambiental

This investigation revealed the existence of a U-inverted curve, i.e. Environmental Kuznets Curve, relating pollutant emissions and technological level of the countries. The model was based on the estimation of regression methods with panel data, using 102 countries during 1960-2000. An alternative approach replaced GDP per capita, by the total factor productivity. In early stages of development, the adoption of dirtier technologies by backward economies is essential for generating knowledge and the future path of innovation. The impact of environmental regulation for these economies can aggravate the technological gap with its neighbors, the developed nations.Esta investigação evidenciou a existência da curva U-invertida, Curva de Kuznets Ambiental, relacionando emissão de poluentes e nível tecnológico dos países. O modelo baseou-se na estimação de métodos de regressão com dados em painel, em amostra de 102 países durante 1960-2000. Adotando uma abordagem alternativa, o PIB per capita foi substituído pela Produtividade Total dos Fatores. Nos estágios iniciais do desenvolvimento, a adoção de tecnologias mais sujas pelas economias atrasadas torna-se essencial na geração do aprendizado e na trajetória futura de inovação. O impacto da regulação ambiental para estas economias pode agravar o gap tecnológico com a vizinhança da fronteira, nações desenvolvidas

Silver nanoparticles-composing alginate/gelatine hydrogel improves wound healing in vivo

Polymer hydrogels have been suggested as dressing materials for the treatment of cutaneous wounds and tissue revitalization. In this work, we report the development of a hydrogel composed of natural polymers (sodium alginate and gelatin) and silver nanoparticles (AgNPs) with recognized antimicrobial activity for healing cutaneous lesions. For the development of the hydrogel, different ratios of sodium alginate and gelatin have been tested, while different concentrations of AgNO3 precursor (1.0, 2.0, and 4.0 mM) were assayed for the production of AgNPs. The obtained AgNPs exhibited a characteristic peak between 430450 nm in the ultraviolet-visible (UVVis) spectrum suggesting a spheroidal form, which was confirmed by Transmission Electron Microscopy (TEM). Fourier Transform Infra-red (FTIR) analysis suggested the formation of strong intermolecular interactions as hydrogen bonds and electrostatic attractions between polymers, showing bands at 2920, 2852, 1500, and 1640 cm1. Significant bactericidal activity was observed for the hydrogel, with a Minimum Inhibitory Concentration (MIC) of 0.50 µg/mL against Pseudomonas aeruginosa and 53.0 µg/mL against Staphylococcus aureus. AgNPs were shown to be non-cytotoxic against fibroblast cells. The in vivo studies in female Wister rats confirmed the capacity of the AgNP-loaded hydrogels to reduce the wound size compared to uncoated injuries promoting histological changes in the healing tissue over the time course of wound healing, as in earlier development and maturation of granulation tissue. The developed hydrogel with AgNPs has healing potential for clinical applications.This research received funding from the Coordenação Aperfeiçoamento de Pessoal de Nivel Superior (CAPES), Fundação de Amparo à Pesquisa do Estado de Sergipe (FAPITEC), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, #443238/2014-6, #470388/2014-5), and from the Portuguese Science and Technology Foundation (FCT) projects M-ERA-NET/0004/2015 (PAIRED) and UIDB/04469/2020 (strategic fund).info:eu-repo/semantics/publishedVersio

Development and evaluation of superabsorbent hydrogels based on natural polymers

Superabsorbent hydrogels (SAHs) are three dimensional networks formed by polymers that can absorb aqueous solution of over 100% of their initial weight. This work aimed to develop and characterize SAHs of Chitosan/Xanthan gum (CG), Chitosan/Alginate (CA) and controlled Chitosan (C), Xanthan gum (G), and Alginate (A) produced using “onion-like” methodology. The swelling performance, the morphological structure, the crystallinity, and the Fourier transformed infrared spectroscopy characteristics of SAH were used for the characterization of polyelectrolytes complex. Swelling analysis showed that chitosan has a strong influence on the maintenance of hydrogels structure after swelling, mainly in the acid environment (pH=2). The chitosan hydrogel presented around 3000% of acidic fluid absorption after 24 h. The chitosan:xanthan gum (1:1 and 2:1 named as C1G1 and C2G1, respectively) hydrogels were the best combination regarding swelling performance in an acid environment, reaching 1665% and 2024%, respectively, as well at pH 7.0, presenting 1005% (C1G1) and 667% (C2G1). Scanning electron microscopy analysis showed samples with pores, and with different shapes. The X-ray diffraction showed the presence of a characteristic peak at 2θ=20° in all developed composition because of the crystalline nature of chitosan. This work shows the possibility of developing eco-friendly biopolymer-based SAHs at a low cost with a good swelling capacity and stability.The research was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior(CAPES/Brazil), Fundação de Amparo a Pesquisa do Estado de Sergipe (FAPITEC, MS/CNPq/FAPITEC/SE/SESN◦06/2018) e do Conselho Nacional de Pesquisas (CNPq, Apoio a Projetos de Pesquisa/MCTI/CNPQ/Universal 14/2014) for supporting funds. EBS acknowledges the Portuguese Science and Technology Foundation (FCT) for the funded projects M-ERA-NET/0004/2015 (PAIRED) and UIDB/04469/2020 (strategic fund) financed from national funds, and cofinanced education (FCT/MEC) from national funds and FEDER, under the Partnership Agreement PT2020. J.J. acknowledges the Ministry of Science and Technical Development of the Republic of Serbia, through Contract Number 200051 172015 OI.info:eu-repo/semantics/publishedVersio

Correction: Diniz et al. Silver Nanoparticles-Composing Alginate/Gelatine Hydrogel Improves Wound Healing In Vivo. Nanomaterials 2020, 10, 390

In the original publication, there was a mistake in Figure 6 as published [...]info:eu-repo/semantics/publishedVersio

Perillyl alcohol in Solid Lipid Nanoparticles (SLN-PA): Cytotoxicity and antitumor potential in sarcoma 180 mice model

Cancer is a group of diseases characterized by the uncontrolled growth of cells. These cells invade organs and tissues by extension or direct dissemination and can spread to other regions of the body. Nanomedicine offers many possibilities to prevent the spread of cancer tissue and help cure the disease. In this work, solid lipid nanoparticles (SLN) were used to encapsulate perillyl alcohol (PA), a volatile monoterpene with proven anticancer activity. Encapsulation of PA into SLN (SLN-PA) is expected to promote controlled release, increase PA bioavailability, and impair the volatility of the monoterpene. SLN-PA prepared by high-shear homogenization showed average particle diameter around 254 nm, polydispersity index ~ 0.35, zeta potential ~ -14.7 mV, and encapsulation efficiency 84.6%. Scanning electron microscope analysis revealed a decrease in crystallinity, suggesting the encapsulation of PA in the SLN, confirming the spherical shape and the loading of the monoterpene in the SLN. In vitro cytotoxicity assays against murine fibroblasts (L929) showed that SLN-PA in both treated doses did not induce any cytotoxicity on non-tumoral cells. In vivo antitumor effect of the SLN-PA was evaluated in sarcoma 180-transplanted mice. The in vivo results demonstrated a significant tumor inhibition rate of 51.76 and 54.49% via intraperitoneal application of SLN-PA at doses of 100 and 200 mg/kg/day (p < 0.05), respective when compared to the negative control (dimethyl sulfoxide). Adverse side effects of SLN-PA were not noticed in the liver, the kidney, or spleen tissue. The developed SLN-PA can be considered as a safe approach for site-specific antitumor effect in vivo, reinterpreting new nanoparticles- based cancer therapy.This work was supported by the Banco do Nordeste (grant FUNDECI/2016.0015), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Apoio à Pesquisa e à Inovação Tecnológica do Estado de Sergipe (Fapitec) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). Eliana B. Souto would like to acknowledge the Portuguese Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE) for the project UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio

IMPACTOS DA POLÍTICA NA ACUMUNIVERULAÇÃO DA RIQUEZA DOS ESTADOS BRASILEIROS: A CONTRIBUIÇÃO DOS INVESTIMENTOS EM INFRAESTRUTURA E DOS ESFORÇOS EM INOVAÇÃO

The aim of this study is to analyze the impact of infrastructure investments and efforts in innovation in the accumulation of wealth of States. To test the assumptions, was adopted the quantile regression method in order to analyze the impact of investments in different income levels. The results of the model show that in less developed economies and low income, lack of infrastructure makes the effect of the higher investment compared to more developed economies and with high income. According as the economy approaches the 'frontier' (high income), the business dynamic will reducing the opportunity costs in the investments in S&T, changing the demand for skilled labor needed to sustain the displacement of the frontier. The absence of this understanding can lead to an inefficient allocation of resources in generating growth in Brazilian States.O artigo busca analisar o impacto dos investimentos em infraestrutura e dos esforços em inovação na acumulação da riqueza dos estados. Foi adotado o método de regressão quantílica com o intuito de analisar o impacto dos investimentos em diferentes níveis de renda. Os resultados do modelo mostram que nas economias menos desenvolvidas e de baixa renda a ausência da infraestrutura torna o efeito do investimento superior em relação às economias mais desenvolvidas e com alta renda. Na medida em que a economia se aproxima da fronteira (a alta renda), o dinamismo dos negócios vai reduzindo os custos de oportunidade nos investimentos em Ciência & Tecnologia (C&T), alterando a demanda por mão de obra qualificada necessária para sustentar o deslocamento da fronteira. A ausência desta compreensão pode conduzir a uma alocação ineficiente dos recursos na geração de crescimento nos estados brasileiros

ARHL and Tinnitus in Portuguese Population: what we can hear from a sample of elderly individuals.

Comunicação apresentada no 10th International Tinnitus Research Initiative Conference, 16-18 de março de 2016, Nottingham, U

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology

Small bowel enteroscopy - A joint clinical guideline from the spanish and portuguese small bowel study groups

The present evidence-based guidelines are focused on the use of device-assisted enteroscopy in the management of small-bowel diseases. A panel of experts selected by the Spanish and Portuguese small bowel study groups reviewed the available evidence focusing on the main indications of this technique, its role in the management algorithm of each indication and on its diagnostic and therapeutic yields. A set of recommendations were issued accordingly.Estas recomendações baseadas na evidência detalham o uso da enteroscopia assistida por dispositivo no manejo clínico das doenças do intestino delgado. Um conjunto de Gastrenterologistas diferenciados em patologia do intestino delgado foi selecionado pelos grupos de estudos Espanhol e Português de intestino delgado para rever a evidência disponível sobre as principais indicações desta técnica, o seu papel nos algoritmos de manejo de cada indicação e sobre o seu rendimento diagnóstico e terapêutico. Foi gerado um conjunto de recomendações pelos autores