Physical-chemical properties of nanocomposites based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and titanium dioxide nanoparticles

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was reinforced with titanium dioxide (TiO2) in concentrations of 1.0%, 2.5% and 5.0% (m/m) to produce nanocomposites by the solvent casting technique. TiO2 was synthesized by a hydrothermal treatment to produce nanoparticles. The nanostructure of the nanoparticles was studied by x-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The XRD confirmed TiO2 crystalline nanoparticles, with a mixture of anatase and rutile phases. Through TEM analysis, the formation of TiO2 nanorod agglomerates with an average diameter and length of 40 and 12 nm, respectively, was observed. The thermal and mechanical properties of the pure PHBV and nanocomposite films were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis. The DSC analysis showed that the glass transition temperature decreased with the inclusion of TiO2 in the PHBV matrix in relation to pure PHBV. The results of biodegradation assays for the PHBV and nanocomposites in an aqueous medium and in soil showed morphological and structural changes for all samples, indicating a high biodegradation rate for this material. The most important conclusion is that the biodegradation of the PHBV was not affected by the addition of nanoparticles, thus enabling the use of nanocomposites in applications requiring biodegradable materials.CNPqFAPESP [2013/14954-6]Fed Univ Sao Paulo Unifesp, Dept Sci & Technol, BR-12231280 Sao Jose Dos Campos, SP, BrazilFed Univ Goias UFG, Dept Chem, BR-75801615 Jatai, Go, BrazilFed Univ Sao Paulo Unifesp, Dept Sci & Technol, BR-12231280 Sao Jose Dos Campos, SP, BrazilFAPESP [2013/14954-6]Web of Scienc

Fingerprints of Short-Range and Long-Range Structure in BaZr1−xHfxO3 Solid Solutions: An Experimental and Theoretical Study

A microwave-assisted hydrothermal method was applied to synthesize BaZr1xHfxO3, (BZHO) solid solutions at a low temperature, 140 1C, and relatively short times, 160 min. The detailed features of the crystal structure, at both short and long ranges, as well as the crystal chemistry doping process, are extensively analysed. X-ray diffraction measurements and Raman spectroscopy have been used to confirm that pure and Hf-doped BZO materials present a cubic structure. Extended X-ray absorption fine structure (EXAFS) spectra indicate that Hf4+ ions have replaced the Zr4+ ions on the 6-fold coordination and a subsequent change on the Ba2+ 12-fold coordination can be sensed. X-ray absorption near-edge structure (XANES) spectroscopy measurements reveal a local symmetry breaking process, associated to overlap of the 4d–2p and 5d–2p orbitals of Zr–O and Hf–O bonds, respectively. Field emission scanning electron microscopy (FE-SEM) and high resolution transmission electron microscopy (HRTEM) show the mesocrystalline nature of self-assembled BZHO nanoparticles under a dodecahedron shape. In addition first principle calculations were performed to complement the experimental data. The analysis of the band structures and density of states of the undoped BZO and doped BZHO host lattice allow deep insight into the main electronic features. The theoretical results help us to find a correlation between simulated and experimental Raman modes and allow a more substantial interpretation of crystal structure.Brazilian research funding institution FAPESP. 2009/17752-0 FAPERGS. 2031-2551/13-9SIAS CNPq (MCT/CNPq). 458452/2014-9 Generalitat Valenciana. Prometeo/2009/053 Ministerio de Ciencia e Innovacion. CTQ-2012-36253-C03-01 Programa de Cooperacion Cientificacon Iberoamerica (Brazil), Ministerio de Educacion. PHB2009-0065-P

Profile of small interfering RNAs from cotton plants infected with the polerovirus Cotton leafroll dwarf virus

<p>Abstract</p> <p>Background</p> <p>In response to infection, viral genomes are processed by Dicer-like (DCL) ribonuclease proteins into viral small RNAs (vsRNAs) of discrete sizes. vsRNAs are then used as guides for silencing the viral genome. The profile of vsRNAs produced during the infection process has been extensively studied for some groups of viruses. However, nothing is known about the vsRNAs produced during infections of members of the economically important family <it>Luteoviridae</it>, a group of phloem-restricted viruses. Here, we report the characterization of a population of vsRNAs from cotton plants infected with Cotton leafroll dwarf virus (CLRDV), a member of the genus <it>Polerovirus</it>, family <it>Luteoviridae</it>.</p> <p>Results</p> <p>Deep sequencing of small RNAs (sRNAs) from leaves of CLRDV-infected cotton plants revealed that the vsRNAs were 21- to 24-nucleotides (nt) long and that their sequences matched the viral genome, with higher frequencies of matches in the 3- region. There were equivalent amounts of sense and antisense vsRNAs, and the 22-nt class of small RNAs was predominant. During infection, cotton <it>Dcl </it>transcripts appeared to be up-regulated, while Dcl2 appeared to be down-regulated.</p> <p>Conclusions</p> <p>This is the first report on the profile of sRNAs in a plant infected with a virus from the family <it>Luteoviridae</it>. Our sequence data strongly suggest that virus-derived double-stranded RNA functions as one of the main precursors of vsRNAs. Judging by the profiled size classes, all cotton DCLs might be working to silence the virus. The possible causes for the unexpectedly high accumulation of 22-nt vsRNAs are discussed. CLRDV is the causal agent of Cotton blue disease, which occurs worldwide. Our results are an important contribution for understanding the molecular mechanisms involved in this and related diseases.</p

Function and diversity of P0 proteins among cotton leafroll dwarf virus isolates

Abstract\ud \ud Background\ud The RNA silencing pathway is an important anti-viral defense mechanism in plants. As a counter defense, some members of the viral family Luteoviridae are able to evade host immunity by encoding the P0 RNA silencing suppressor protein. Here we explored the functional diversity of P0 proteins among eight cotton leafroll dwarf virus (CLRDV) isolates, a virus associated with a worldwide cotton disease known as cotton blue disease (CBD).\ud \ud \ud Methods\ud CLRDV-infected cotton plants of different varieties were collected from five growing fields in Brazil and their P0 sequences compared to three previously obtained isolates. P0’s silencing suppression activities were scored based on transient expression experiments in Nicotiana benthamiana leaves.\ud \ud \ud Results\ud High sequence diversity was observed among CLRDV P0 proteins, indicating that some isolates found in cotton varieties formerly resistant to CLRDV should be regarded as new genotypes within the species. All tested proteins were able to suppress local and systemic silencing, but with significantly variable degrees. All P0 proteins were able to mediate the decay of ARGONAUTE proteins, a key component of the RNA silencing machinery.\ud \ud \ud Conclusions\ud The sequence diversity observed in CLRDV P0s is also reflected in their silencing suppression capabilities. However, the strength of local and systemic silencing suppression was not correlated for some proteins.Instituto Matogrossense do AlgodãoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de\ud Janeiro (FAPERJ

Antimicrobial evaluation of quinones and heterocyclic compounds against mycobacterium marinum, M. kansasii and M. abscessus

The resistance to antimicrobials and biocides observed in mycobacteria which do not cause tuberculosis (MNT) determines the necessity to develop drugs. The present study evaluated the activity of naphthoquinones and heterocyclic derivatives obtained from lapachol against Mycobacterium kansasii, M. marinum, and M. abscessus, through the REMA method. It was observed that lapachol was inactive against the three mycobateria species, while β-lapachone and nor-β-lapachone showed activity only against M. marinum. The most active substances for M. kansasii were the derivates 2, 3, 7, and 11, in which compound 2 (CMI = 0.96 μM) was the most active. For M. marinum, 2, 11, and 14 were the most active, while against M. abcessus the compound 3 was the only active. The results showed a wide and diversified resistance spectrum among the species studied, which could be related to the molecular structure and position of the substituting groups, indicating the potentiality of these molecules as antimicrobial prototypes.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Psychology, the United Health System (SUS) and the Ambulatory Care Information System (SIA): innovations, propositions and misdirections

Desde as primeiras incursões de psicólogos no sistema público de saúde discute-se a adeqüabilidade de seus padrões de atuação que, atualmente, redundam numa atenção curativa, individual e ineficiente. Contudo, ressalta-se a interferência das deliberações, orientações e exigências do Sistema Único de Saúde na figura do Sistema de Informações Ambulatoriais (SIA/SUS) que fornece uma lista de procedimentos a serem desenvolvidos pelos psicólogos. Este estudo analisou estatísticas dos procedimentos realizados pela Psicologia em Natal/RN, disponíveis no SIA/SUS, com o objetivo de dimensionar como sua estrutura influencia a manutenção dos modelos de atuação. Os dados revelam uma permanência de ações compartimentalizadas, cuja maior proporção abrange os quadros mórbidos. A dificuldade para o desenvolvimento de ações diferentes ou obriga os profissionais a registrarem-nas de forma distorcida, ou os resigna aos atendimentos previstos. Na Psicologia, o sistema de informações restringe atividades que poderiam configurar um modelo de atuação condizente com os ideais da reforma sanitária.Palavras-chave: Psicologia; Saúde Pública; Sistema de Informações Ambulatoriais.  The adequability of Psychology patterns of intervention have been discussed since the first incursions of psychologists on the Public Health System, that have a redundant health care, individual and inefficient. However, the interference on deliberations, orientations and exigencies of the Brazilian United Health System’s Ambulatory Care Information System (SIA/SUS), that provides psychologists with a set of procedures has been overlooked. This study analised the reports of psychological procedures in Natal/RN, available at SIA/SUS, aiming to verify how its structure influences the maintenance of models of professional practice. Data suggest a permanence of compartmentalized actions, specially in morbid occurrences. Constraints to the development of innovative actions has led psychology professionals either to record them in a disguised format or to persist in using traditional procedures. It is our conclusion that, in what concerns Psychology, the information system constrains the development of a model of professional practice more in agreement with the sanitation reform ideals.   Keywords: Psychology; Public Health; Ambulatory Care Information System

Ultrasound-Assisted Preparation of Brazil Nut Oil-in-Water Emulsions Stabilized by Arabic Gum

&nbsp;The objective of this work is to evaluate the stability of Brazil nut oil emulsions with gum Arabic using ultrasound-assisted homogenization. The emulsions were prepared in a completely randomized design varying the time (2 and 4 min) and the ultrasound power (30 and 40%). The physicochemical properties of the emulsions (pH, conductivity, turbidity, zeta potential, surface tension, rheology and optical microscopy) were evaluated after the homogenization process and 4 hours later. The results showed that more energetic homogenization processes (longer duration and higher ultrasound power) favored the physicochemical properties, keeping the emulsions more stable. Thus, Brazil nut oil emulsions prepared with ultrasound-assisted showed good physic-chemical characteristics that can guarantee good emulsion stability during spray drying, guaranteeing efficiency and protection of the physical and chemical properties of the Brazil nut oil