Photoactivity of nanostructured porous Nb2O5 : effect of Pt, Ta, Cu, and Ti impregnation

In the present work, we report the obtaining of nanostructured porous Nb2O5 by anodizing process, with Pt, Ta, Cu, or Ti impregnation, and by magnetron sputtering process. The techniques of scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used to evaluate the morphology, and the composition and crystalline structure of nanoporous Nb2O5. The photocatalytic activity was evaluated by electrochemical photocurrent tests under UV light illumination. Nanostructured porous Nb2O5 with Pt, Ta, Cu, and Ti impregnation presented bandgap reduction and 10 times higher photocurrent density in the presence of UV light when compared to the not impregnated nanoporous Nb2O5

Catalytically active membrane-like devices: ionic liquid-hybrid organosilicas decorated with palladium nanoparticles

Ionic liquid (IL)-hybrid organosilicas based on 1-n-butyl-3-(3-trimethoxysilylpropyl)-imidazolium cations associated with hydrophilic and hydrophobic anions decorated with well dispersed and similar sized (1.8–2.1 nm) Pd nanoparticles (Pd-NPs) are amongst the most active and selective catalysts for the partial hydrogenation of conjugated dienes to monoenes. The location of the sputter-imprinted Pd-NPs on different supports, as determined by RBS and HS-LEIS analysis, is modulated by the strength of the contact ion pair formed between the imidazolium cation and the anion, rather than the IL-hybrid organosilica pore size and surface area. In contrast, the pore diameter and surface area of the hybrid supports display a direct correlation with the anion hydrophobicity. XPS analysis showed that the Pd(0) surface component decreases with increasing ionic bond strength between the imidazolium cation and the anions (contact ion pair). The finding is corroborated by changes in the coordination number associated with the Pd-Pd scattering in EXAFS measurements. Hence, the interaction of the IL with the metal surface is found to occur via IL contact pairs (or aggregates). The observed selectivities of ≥99% to monoenes at full diene conversion indicate that the selectivity is intrinsic to the electron deficient Pd-metallic surfaces in this “restricted” ionic environment. This suggests that IL-hybrid organosilica/Pd-NPs under multiphase conditions (“dynamic asymmetric mixture”) operate akin to catalytically active membranes, i.e. far from the thermodynamic equilibrium. Detailed kinetic investigations show that the reaction rate is zero-order with respect to hydrogen and dependent on the fraction of catalyst surfaces covered by either the substrate and/or the product. The reaction proceeds via rapid inclusion and sorption of the diene to the IL/Pd metal surface saturated with H species. This is followed by reversible hydride migration to generate a π-allyl intermediate. The reductive elimination of this intermediate, the formal rate-determining step (RDS), generates the alkene that is rapidly expelled from the IL phase to the organic phase

Maternal periodontitis induces intergenerational injuries on reproductive performance of adult female rat offspring

Substantial evidence suggests a direct link between periodontitis in pregnant women and subsequent adverse pregnancy outcomes. However, no studies have evaluated the transgenerational effects of periodontitis on the reproductive performance of subsequent generations. The present study investigated whether maternal periodontal disease exerts deleterious transgenerational effects on reproductive performance in F1 female rats. Rat female offspring from mothers that were subjected to experimentally induced periodontitis or sham operation were mated with sexually experienced male rats. The weight and reproductive performance of these F1 offspring were evaluated on gestation day 21, including maternal weight, litter weight, individual pup weight, number of pups, and number of resorptions. The percentage of dams with resorptions and the litter weight/number of pups were also calculated. Compared with the control group, an increase was observed in the percentage and number of resorptions and litter weight/number of pups, and a decrease was observed in the number of pups born in the experimental group. Maternal weight, litter weight, and individual pup weight were not different between the control and experimental groups. Maternal periodontitis impaired reproductive performance in the F1 generation. We showed that periodontitis may induce reproductive injury in adult offspring even if the offspring do not undergo any inflammatory/infectious process during their postnatal life or during gestation. These findings reinforce the importance of oral care during pregnancy. Existem evidências substanciais de uma relação direta entre periodontite em mulheres grávidas com efeitos adversos reprodutivos. No entanto, nenhum estudo avaliou os efeitos intergeracionais da periodontite sobre o desempenho reprodutivo das gerações subsequentes. O presente estudo investigou se a doença periodontal materna exerce efeitos intergeracionais deletérios sobre o desempenho reprodutivo em ratos fêmeas da geração F1. Assim, filhas de ratas cujas mães foram submetidas a periodontite experimental ou falsamente operadas foram acasaladas com ratos machos sexualmente experientes. O peso corporal e desempenho reprodutivo da geração F1 foram avaliados no dia 21 de gestação, incluindo o peso materno, peso da ninhada, peso da individual dos filhotes, número de filhotes e de reabsorções. A percentagem de fêmeas com reabsorção e o peso da ninhada/número de filhotes também foram calculados. Comparados com o grupo controle, observou-se aumento na porcentagem e número de reabsorções e no peso da ninhada/ número de filhotes, e decréscimo no número de filhotes nascidos no grupo experimental. O peso materno, peso da ninhada e individual dos filhotes não foi diferente entre o controle e experimental. Estes resultados mostram que a periodontite experimental materna prejudica o desempenho reprodutivo da geração F1, mesmo que estes animais não tenham sido expostos diretamente a um processo inflamatório

Potential control of oxygen non-stoichiometry in cerium oxide and phase transition away from equilibrium

Cerium oxide (ceria, CeO2) is a technologically important material for energy conversion applications. Its activities strongly depend on redox states and oxygen vacancy concentration. Understanding the functionality of chemical active species and behavior of oxygen vacancy during operation, especially in high temperature solid-state electrochemical cells, is the key to advance future material design. Herein, the structure evolution of ceria is spatially resolved using bulk sensitive operando X-ray diffraction and spectroscopy techniques. During water electrolysis, ceria undergoes reduction, and its oxygen non-stoichiometry shows a dependence on the electrochemical current. Cerium local bonding environments vary concurrently to accommodate oxygen vacancy formation, resulting in changes in Ce−O coordination number and Ce3+/Ce4+ redox couple. When reduced enough, a crystallographic phase transition occurs from α to an α′ phase with more oxygen vacancies. Nevertheless, the transition behavior is intriguingly different from the one predicted in the standard phase diagram of ceria. This paper demonstrates a feasible means to control oxygen non-stoichiometry in ceria via electrochemical potential. It also sheds light on the mechanism of phase transitions induced by electrochemical potential. For electrochemical systems, effects from a large-scale electrical environment should be taken into consideration, besides effective oxygen partial pressure and temperature

HIPERPARATIREOIDISMO NUTRICIONAL SECUNDÁRIO EM EQUINOS E RUMINANTES: REVISÃO DE LITERATURA

O hiperparatireoidismo nutricional secundário é um distúrbio metabólico que acomete principalmente equídeos, mas pode se manifestar em caprinos e suínos. A etiologia está relacionada a alterações nas concentrações séricas de cálcio e fósforo devido à ingestão desbalanceada na dieta, levando a hipersecreção do paratormônio e consequente hiperparatireoidismo, que se manifesta por osteodistrofia fibrosa. A apresentação clássica é o aumento de volume, em geral bilateral e simétrico, dos ossos do crânio, sendo que o diagnóstico baseia-se principalmente na presença desta alteração. Entretanto, outros ossos também podem ser acometidos. Testes bioquímicos podem contribuir para o diagnóstico ao revelarem concentrações séricas de cálcio ionizado abaixo dos valores de referência e teor sérico de fósforo orgânico acima do normal, além de aumento na atividade da enzima fosfatase alcalina. Exames radiográficos demonstram opacidade óssea diminuída. O tratamento consiste principalmente na correção do desequilíbrio cálcio:fósforo na dieta e a profilaxia é de extrema importância a fim de se evitar prejuízos econômicos

A busca de uma identidade para a indústria 4.0 / The search for an industry 4.0 identity

Adotada pelo governo alemão em 2012, no contexto da quarta revolução industrial, a iniciativa Industrie 4.0 busca explorar o alto potencial econômico resultante da utilização de tecnologias de informação e comunicação na indústria. Apesar de um aumento de visibilidade no campo industrial, o termo Indústria 4.0 continua impreciso, fato que representa um obstáculo para pesquisa científica. No trabalho realizado, busca-se compreender o perfil das publicações nessa linha de pesquisa, bem como a identificação das principais palavras-chave associadas ao tema. Para isso, foi conduzida uma revisão integrativa da literatura na base de dados Scopus. Os resultados indicam um crescimento de publicações vinculados principalmente à Alemanha. Por fim, uma listagem das principais palavras-chave foi compilada para auxiliar pesquisadores interessados no tema

Reflexo do período de lactação na produtividade de porcas primíparas e multíparas

O período de lactação é um importante aspecto na produtividade de granjas suínas, já que influencia diretamente os dias do ciclo produtivo e a fisiologia da reprodução das matrizes. O objetivo deste trabalho foi verificar o efeito do período de lactação (PL) no intervalo desmame-estro (IDE), taxa de parição ajustada (TPA) e tamanho da leitegada subseqüente (TLS) em um rebanho comercial. Dados referentes a 19.846 desmames realizados em 2002 e 2003 foram coletados a partir do programa de gerenciamento de dados PigCHAMP  ®. Para multíparas, PL de 15 dias foram suficientes para a estabilização do IDE (4,8 ± 2,8 dias). As primíparas apresentaram IDE mais curto com PL de 20-24 dias (4,7 ± 2,5 dias). Houve redução na TPA somente em PL inferiores a 10 dias, tanto em primíparas como em multíparas. Para primíparas, períodos de lactação a partir de 17 dias resultaram em estabilização do TLS. As porcas multíparas apresentaram aumento gradativo do TLS até 15-16 dias de lactação, quando houve estabilização. A duração da lactação influencia o desempenho reprodutivo subseqüente em primíparas e multíparas suínas. Períodos de lactação de duas semanas podem ser adequados para multíparas, mas três semanas seriam necessárias para melhor desempenho das primíparas

TEOS thin films obtained by plasma polymerization on Ti6Al4V alloys : influence of the deposition pressure on surface properties and cellular response

The modification of surfaces by the application of thin films has been used in the regenerative medicine area to increase the biocompatibility of metal implants. Titanium alloy has been recently used as substrate in poly merization for biomedical application. In this context, silane films were obtained by plasma polymerization in favor of the sol-gel method and the influence of different pressures in obtaining these films by argon plasma polymerization was evaluated from the alkoxysilane precursor tetraethoxysilane (TEOS) on the Ti6Al4V alloy. The morphological characterization of the films was performed by AFM, Profilometry and Spectral Ellipsometry and the chemical composition was analyzed by XPS. The biological behavior was evaluated by analyzing the mitochondrial activity and cellular viability of mesenchymal stem cells. The plasma polymerization process resulted in the deposition of a nanometric Si-based film formed, predominantly, by Si-O and organosilane bonds. The films that were applied on a sanded surface, with lower pressures in the plasma polymerization process, presented a lower layer thickness and wettability than the films obtained on nanotextured surfaces. Considering absorbance values, the Ti6Al4V samples mechanically sanded and deposited by plasma polymerization at 230 µatm presented better cell viability than samples with nanotextured surfaces coated with plasma polymerized film, indicating this material has potential to biomedical application

Probability of target attainment of tobramycin treatment in acute and chronic pseudomonas aeruginosa lung infection based on preclinical population pharmacokinetic modeling

Abstract: Biofilms and infectious process may alter free antimicrobial concentrations at the site of infection. Tobramycin (TOB), an aminoglycoside used to treat lung infections caused by Pseudomonas aeruginosa, binds to alginate present in biofilm extracellular matrix increasing its minimum inhibitory concentration (MIC). This work aimed to investigate the impact of biofilm-forming P. aeruginosa infection on TOB lung and epithelial lining fluid (ELF) penetration, using microdialysis, and to develop a population pharmacokinetic (popPK) model to evaluate the probability of therapeutic target attainment of current dosing regimens employed in fibrocystic and non-fibrocystic patients. The popPK model developed has three compartments including the lung. The ELF concentrations were described by a penetration factor derived from the lung compartment. Infection was a covariate in lung volume (V3) and only chronic infection was a covariate in central volume (V1) and total clearance (CL). Simulations of the recommended treatments for acute and chronic infection achieved >90% probability of target attainment (PTA) in the lung with 4.5 mg/kg q24h and 11 mg/kg q24h, respectively, for the most prevalent P. aeruginosa MIC (0.5 mg/mL). The popPK model was successfully applied to evaluate the PTA of current TOB dosing regimens used in the clinic, indicating the need to investigate alternative posology