Stability of antiphase line defects in nanometer-sized boron-nitride cones

We investigate the stability of boron nitride conical sheets of nanometer size, using first-principles calculations. Our results indicate that cones with an antiphase boundary (a line defect that contains either B-B or N-N bonds) can be more stable than those without one. We also find that doping the antiphase boundaries with carbon can enhance their stability, leading also to the appearance of localized states in the bandgap. Among the structures we considered, the one with the smallest formation energy is a cone with a carbon-modified antiphase boundary that presents a spin splitting of about 0.5 eV at the Fermi level.Comment: 5 two-column pages with 2 figures Accepted for publication in Physical Review B (vol 70, 15 Nov.

Synthesis of bio-based Polyester from microbial lipidic residue intended for biomedical application

In the last decade, selectively tuned bio-based polyesters have been increasingly used for their clinical potential in several biomedical applications, such as tissue engineering, wound healing, and drug delivery. With a biomedical application in mind, a flexible polyester was produced by melt polycondensation using the microbial oil residue collected after the distillation of β-farnesene (FDR) produced industrially by genetically modified yeast, Saccharomyces cerevisiae. After characterization, the polyester exhibited elongation up to 150% and presented Tg of −51.2 °C and Tm of 169.8 °C. In vitro degradation revealed a mass loss of about 87% after storage in PBS solution for 11 weeks under accelerated conditions (40 °C, RH = 75%). The water contact angle revealed a hydrophilic character, and biocompatibility with skin cells was demonstrated. 3D and 2D scaffolds were produced by salt-leaching, and a controlled release study at 30 °C was performed with Rhodamine B base (RBB, 3D) and curcumin (CRC, 2D), showing a diffusion-controlled mechanism with about 29.3% of RBB released after 48 h and 50.4% of CRC after 7 h. This polymer offers a sustainable and eco-friendly alternative for the potential use of the controlled release of active principles for wound dressing applications.info:eu-repo/semantics/publishedVersio

Bovine tuberculosis in the state of Paraíba: retrospective survey

O objetivo do presente trabalho foi determinar a frequência de propriedades positivas (focos) e de animais positivos para a tuberculose bovina no Estado da Paraíba. Foram utilizados dados da Agência de Defesa Agropecuária do Estado, coletados de suas 23 microrregiões, durante o período de janeiro de 2008 a julho de 2009. Durante esse período, foram examinadas 10.963 propriedades e 54.472 bovinos foram submetidos ao teste de tuberculinização. Para o diagnóstico foi utilizada, como prova de triagem, a tuberculinização cervical simples para gado de leite e a tuberculinização na prega caudal para gado de corte; como prova confirmatória foi utilizada a tuberculinização cervical comparativa. Uma propriedade foi considerada foco quando apresentou pelo menos um animal soropositivo. Das propriedades investigadas, 62 (0,57%) apresentaram pelo menos um animal positivo e dos animais analisados, 136 (0,25%) foram positivos. Houve diferença significativa (p<0,001) na proporção de fêmeas (0,32%) e machos (0,04%) positivos. A despeito da baixa freqüência de focos de brucelose e de animais soropositivos, é necessária a condução de medidas que incluem a conscientização dos produtores, fiscalização nas barreiras sanitárias e levantamentos periódicos da situação epidemiológica desta doença, principalmente nas microrregiões com maior frequência da infecção, com o objetivo de evitar, ou pelo menos minimizar, a disseminação do agente.The aim of this study was to determine the frequency of positive herds (foci) and positive animals for bovine tuberculosis in the state of Paraíba, Northeast region of Brazil. Data from the Agency of Agricultural Protection in the state, collected from its 23 microregions, during the January 2008 to July 2009 period, were used. During this period, 10,963 herds were examined and 54,472 cattle were submitted to the tuberculin test. For diagnosis the cervical and caudal-fold tuberculin tests were used as screening tests in dairy and beef cattle, respectively; as confirmatory test, comparative cervical test was used. A herd was considered focus when presented at least one positive animal. Of the herds investigated, 62 (0.57%) had at least one positive animal, and of the animals examined, 136 (0.25%) were positive. There was significant difference (p<0.001) in the proportion of positivity for females (0.32%) and males (0.04%). Despite low frequency of foci of brucellosis and seropositive animals, it is necessary to conduct measures including awareness of producers, surveillance in sanitary barriers and periodic surveys of epidemiological situation of this disease especially in the regions with highest frequency of infection, aiming to avoid, or at least minimize, the spread of the agent

Hyperandrogenic chronic anovulation and psychologic disturbances

The authors have reviewed the main aspects of the polycystic ovary syndrome (PCOS) with respect to its etiopathogenic, clinical, diagnostic and therapeutic features, highlighting the psychological distresses that frequently arise in the syndrome. They also make considerations on the importance of an effective clinical treatment as well as on the approaches and psychological support, aiming to improve womens well-being and quality of life.Os autores fazem uma revisão da síndrome dos ovários policísticos (SOP) com relação aos seus aspectos etiopatogênicos, clínicos, diagnósticos e terapêuticos, dando ênfase aos transtornos de ordem psíquica que freqüentemente acompanham esse distúrbiio. Tecem considerações sobre a importância não só de um efetivo tratamento médico, mas também de uma abordagem e um apoio psicológico, no sentido de melhorar ainda mais o bem-estar e a qualidade de vida dessas mulheres

Seroprevalence of bovine leptospirosis in reproductive-age female bovines in the state of São Paulo, Brazil

O presente estudo teve como objetivo determinar a soroprevalência da leptospirose bovina em fêmeas em idade reprodutiva do Estado de São Paulo, estratificado em sete regiões produtoras. Foram utilizados o delineamento estatístico, as amostras sorológicas e as informações contidas nos questionários empregados no Programa Nacional de Controle e Erradicação da Brucelose e Tuberculose (PNCETB), instituído pelo Ministério da Agricultura, Pecuária e Abastecimento, considerando-se a utilização de fêmeas bovinas com idade '> OU =' a 24 meses (excluindo-se machos), diferentes tipos de produção, práticas de manejo, finalidades de reprodução, tamanho dos rebanhos e sistema de comercialização. Realizou-se a Soroaglutinação Microscópica (SAM) em 8.216 amostras sorológicas de animais provenientes de 1.021 propriedades. De acordo com os resultados obtidos, a infecção por Leptospira spp. ocorre em todo o Estado de São Paulo, com soroprevalência de 49,4% (IC 95% = 44,4%-54,4%) nas fêmeas bovinas em idade reprodutiva e em 718 (71,3%; IC 95% = 68,5%-74%) das propriedades analisadas. O sorovar Hardjo (46%) e sua associação com o sorovar Wolffi (21%) foram prevalentes entre o total de animais sororeagentes, seguidos pelos sorovares Shermani (8,9%), Autumnalis (4,4%) e Grippotyphosa (3,9%). Leptospira spp. está distribuída por todo estado e independe do tipo de exploração, manejo e das práticas de reprodução adotadas nos rebanhosThe objective of the present study was to determine the seroprevalence of bovine leptopirosis in São Paulo State, stratified in seven cattle production regions. It was based on the statistic delineation, serological samples and responses to the survey employed in the National Program for Control and Eradication of Brucelosis and Tuberculosis established by Ministry of Agriculture (2001). From the herds selected, serological analysis was only conducted on the cows '> OU =' 24 months old (excluding the males). The study took into consideration the herd size, the type of productive exploration, the reproductive handling, bovine practices and the commercialization system. The microscopic agglutination test (MAT) was applied on 8,216 serum samples from 1,021 different farms. The results showed that leptospirose infection occurs all over the seven regions of São Paulo State with 49.4% (CI 95% = 44.4-54.4%) animal seroprevalence and in 718 (71.3%; CI 95% = 68.5-74.0%) of the herds analyzed. Hardjo (46%) was the prevalent serovar for all the animals examined, followed by the Hardjo/Wolffi association (21%), Shermani (8.9%), Autumnalis (4.4%) and Grippotyphosa (3.9%). Leptospira spp. is present in all regions of the State of São Paulo and its occurrence is independent of the handling conditions and reproductive practices adopted in the herd

Molecular characterization of the Corynebacterium pseudotuberculosis hsp60-hsp10 operon, and evaluation of the immune response and protective efficacy induced by hsp60 DNA vaccination in mice

<p>Abstract</p> <p>Background</p> <p>Heat shock proteins (HSPs) are important candidates for the development of vaccines because they are usually able to promote both humoral and cellular immune responses in mammals. We identified and characterized the <it>hsp60-hsp10 </it>bicistronic operon of the animal pathogen <it>Corynebacterium pseudotuberculosis</it>, a Gram-positive bacterium of the class <it>Actinobacteria</it>, which causes caseous lymphadenitis (CLA) in small ruminants.</p> <p>Findings</p> <p>To construct the DNA vaccine, the <it>hsp60 </it>gene of <it>C. pseudotuberculosis </it>was cloned in a mammalian expression vector. BALB/c mice were immunized by intramuscular injection with the recombinant plasmid (pVAX1/<it>hsp60</it>).</p> <p>Conclusion</p> <p>This vaccination induced significant anti-hsp60 IgG, IgG1 and IgG2a isotype production. However, immunization with this DNA vaccine did not confer protective immunity.</p

Compensatory epistasis explored by molecular dynamics simulations

A non-negligible proportion of human pathogenic variants are known to be present as wild type in at least some non-human mammalian species. The standard explanation for this finding is that molecular mechanisms of compensatory epistasis can alleviate the mutations’ otherwise pathogenic effects. Examples of compensated variants have been described in the literature but the interacting residue(s) postulated to play a compensatory role have rarely been ascertained. In this study, the examination of five human X-chromosomally encoded proteins (FIX, GLA, HPRT1, NDP and OTC) allowed us to identify several candidate compensated variants. Strong evidence for a compensated/compensatory pair of amino acids in the coagulation FIXa protein (involving residues 270 and 271) was found in a variety of mammalian species. Both amino acid residues are located within the 60-loop, spatially close to the 39-loop that performs a key role in coagulation serine proteases. To understand the nature of the underlying interactions, molecular dynamics simulations were performed. The predicted conformational change in the 39-loop consequent to the Glu270Lys substitution (associated with hemophilia B) appears to impair the protein’s interaction with its substrate but, importantly, such steric hindrance is largely mitigated in those proteins that carry the compensatory residue (Pro271) at the neighboring amino acid position

Prevalence of leptospirosis in dairy goats in the semiarid region of Paraíba state

Este trabalho teve como objetivos determinar a prevalência de propriedades de caprinos leiteiros positivas e de animais soropositivos para leptospirose no semiárido paraibano. A amostragem foi delineada para a determinação da prevalência de propriedades positivas (focos) e de animais soropositivos para a infecção por Leptospira spp. No total, foram colhidas amostras de sangue de 975 animais procedentes de 110 propriedades leiteiras localizadas no Munícipio de Monteiro, microrregião do Cariri Ocidental, Estado da Paraíba. Para o diagnóstico da infecção por Leptospira spp., foi utilizado o teste de soroaglutinação microscópica (SAM), utilizando como antígenos 24 sorovares. Uma propriedade foi considerada foco quando apresentou pelo menos um animal soropositivo. As prevalências de propriedades positivas e de animais soropositivos foram de 43,6% (IC 95% = 34,2-53,4%) e de 8,7% (IC 95% = 5,7-12,9%), respectivamente. Nos animais, os sorovares mais frequentes foram Autumnalis (1,74%; IC 95% = 0,97-3,09%), Sentot (1,71%; IC 95% = 0,82-3,52%) e Whitcomb (1,39%; IC 95% = 0,65-2,93%), e nas propriedades, os sorovares Autumnalis (10,9%; IC 95% = 5,8-18,3%), Whitcomb (8,2%; IC 95% = 3,8-15,0%) e Sentot e Patoc (7,3%; IC 95% = 3,2-13,8%) foram os mais frequentes. Sugere-se que a infecção está distribuída em caprinos da região, e que há necessidade de implantação de medidas de controle e prevenção, com o intuito de reduzir a ocorrência da infecção e, consequentemente, diminuir perdas econômicas ocasionadas e bloquear a possível transmissão do agente aos seres humanos

Comparação entre rações para frangos de corte mais vendidas no Rio Grande do Sul. III. Rendimento Econômico

Six different commercial broiler rations were compared as to performance and economic aspects. The six rations selected were those sold in the greatest volume. Significant differences in gain of weight and feed conversion were found. However, these data alone were insufficient to classify the rations according to their economic value. It was necessary to consider the total production cost to determine the most profitable ration.São estudados e discutidos a performance e o aspecto econômico da criação de frangos de corte com seis rações diferentes. Foram escolhidas as rações de maior comercialização no Rio Grande do Sul. Foram obtidas diferenças significantes entre estas rações com referência ao ganho de peso e conversão alimentar. Estes dados, isoladamente, mostraram-se insuficientes para avaliar as rações do ponto de vista econômico, mas, quando unidos ao custo total de criação, tornaram possível determinar quais as rações econômicamente mais proveitosas