6,237 research outputs found

    Fauna de solo: aspectos gerais e metodológicos.

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    Fauna de solo como agente de modificações de processos no solo. Organização de comunidades. Estrutura da comunidade. A densidade e a diversidade das comunidades de solo como indicadora de modificações ambientais . Metodologias de estudo da fauna de solo.bitstream/CNPAB-2010/27350/1/doc112.pd

    Bioactive macro/micro porous silk fibroin/Nano-sized calcium phosphate scaffolds with potential for bone tissue engineering applications

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    Aim: The development of novel silk/nano-sized calcium phosphate (silk/nano-CaP) scaffolds with highly dispersed CaP nanoparticles in the silk fibroin (SF) matrix for bone tissue engineering. Materials & methods: Nano-CaP was incorporated in a concentrated aqueous SF solution (16 wt.%) by using an in situ synthesis method. The silk/nano-CaP scaffolds were then prepared through a combination of salt-leaching/ lyophilization approaches. Results: The CaP particles presented good affinity to SF and their size was inferior to 200 nm when theoretical CaP/silk ratios were between 4 and 16 wt.%, as determined by scanning electron microscopy. The CaP particles displayed a uniform distribution in the scaffolds at both microscopic and macroscopic scales as observed by backscattered scanning electron microscopy and micro-computed tomography, respectively. The prepared scaffolds presented self-mineralization capability and no cytotoxicity confirmed by in vitro bioactivity tests and cell viability assays, respectively. Conclusion: These results indicated that the produced silk/nano-CaP scaffolds could be suitable candidates for bone-tissueengineering applications.This study was funded by the Portuguese Foundation for Science and Technology (FCT) through the projects Tissue2Tissue (PTDC/CTM/105703/2008) and Osteo Cart (PTDC/CTM-BPC/115977/2009). The funding from Foundation Luso-Americana is greatly acknowledged. L-P Yan gives thanks for his PhD scholarship from FCT (SFRHIBD/64717/2009). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or potions, expert testimony, grants or patents received or pending, or royalties

    Tuberculosis among the homeless: should we change the strategy?

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    BACKGROUND: Tuberculosis (TB) is a major concern among high-risk populations such as the homeless. OBJECTIVES: To evaluate TB incidence and treatment outcomes among homeless patients in Portugal and to identify predictors of unsuccessful TB treatment outcomes among the homeless. DESIGN: This was a retrospective cohort study of all TB patients notified in Portugal from 2008 to 2014. Characteristics of homeless TB patients were assessed and predictors of unsuccessful TB treatment were determined using logistic regression. RESULTS: TB incidence among the homeless was 122/100 000 homeless persons and was positively correlated with TB incidence among non-homeless persons. Homeless TB patients had a higher prevalence of alcohol and/or drug use, human immunodeficiency virus (HIV) co-infection, cavitary TB and smear positivity. The rate of unsuccessful treatment outcomes among the homeless was 28.6%, and was significantly associated with increased age, injection drug use (IDU) and HIV co-infection. CONCLUSION: TB incidence among homeless persons was five times that among the non-homeless, and higher in regions with greater TB incidence among non homeless persons. The successful treatment outcome rate was lower. Predictors of unsuccessful treatment were age, IDU and HIV co-infection. Integrated TB programmes targeting homeless and non-homeless patients, with measures targeting specific characteristics, may contribute to TB elimination in Portugal.CONTEXTE : La tuberculose (TB) est un souci majeur dans les populations à haut risque comme les personnes sans domicile fixe. OBJECTIFS : Evaluer le taux d’incidence de la TB et les resultats du traitement parmi des patients sans domicile fixe au Portugal et identifier les facteurs de préediction d’ échec du traitement de la TB parmi ces patients. SCHÉMA : Etude rétrospective de cohorte incluant tous les patients TB notifies au Portugal entre 2008 et 2014. Les caractéristiques des patients sans domicile fixe ont été ́évaluées et les facteurs de prédiction d’ échec du traitement de la TB ont été déterminés par ŕegression logistique. RESULTATS : Le taux d’incidence de la TB parmi les personnes sans domicile fixe a été de 122/100 000, et il a été positivement corrélé avec l’incidence de la TB parmi le reste de la population. Les patients tuberculeux sans domicile fixe avaient une prévalence plus élevée de consommation d’alcool et/ou de drogues, de co- infection au virus de l’immunodéficience humaine (VIH), de forme caverneuse et de frottis positif. Le taux d’ ́echec du traitement a ́et ́e de 28,6% ; l’ ́echec a ́ et ́esignificativement associé à un âge plus avancé, à la consommation de drogues injectables et à la co-infection par le VIH. CONCLUSION : L’incidence dela TB parmi les personnes sans domicile fixe a été cinq fois plus élevée que celle du reste de la population et plus haute dans les régions ou l’incidence dans le reste de la population est egalement plus élevée. Leur taux d’ échec du traitement à été plus faible. Les facteurs de prédiction d’ échec du traitement ont été l´âge, la consommation de drogues injectables et la co-infection `a VIH. Des programmes de TB intégrés ciblant les patients sans domicile fixe et les autres, avec des mesures spécifiques adaptées à leurs caractéristiques particulières, pourrait contribuer à l’ élimination de la TB au Portugal.MARCO DE REFERENCIA: La tuberculosis (TB) constituye una gran preocupación en las poblaciones muy vulnerables como las personas sin hogar. OBJETIVOS: Evaluar la tasa de incidencia de TB y los desenlaces terapéuticos en las personas sin domicilio en Portugal y definir los factores pronósticos de fracaso terapéutico en este grupo de la población. MÉTODO: Fue este un estudio retrospectivo de cohortes de todos los pacientes con diagnóstico de TB notificados del 2008 al 2014 en Portugal. Mediante un análisis de regresión logística se analizaron las características de los pacientes tuberculosos sin hogar y los factores pronósticos de fracaso terapéutico. RESULTADOS: La tasa de incidencia de TB en la población sin hogar fue 122 por 100 000 personas y exhibió una correlación positiva con la incidencia de TB en las personas con domicilio. Los pacientes con diagnóstico de TB y sin hogar presentaron una prevalencia más alta de consumo de alcohol y/o de drogas, de coinfección por el virus de la inmunodeficiencia humana (VIH), de lesiones cavernosas y de resultados positivos de la baciloscopia. La tasa de fracaso terapéutico en esta población fue 28,6% y se asoción de manera significativa con una mayor edad, el consumo de drogas intravenosas y la coinfección por el VIH. CONCLUSIÓN: La incidencia de TB en las personas sin hogar fue cinco veces mayor que en las personas con domicilio y fue más alta en las regiones con una mayor incidencia de TB en las personas con domicilio. La tasa de éxito terapéutico en las personas sin hogar fue más baja. Los factores pronósticos de fracaso terapéutico fueron la edad, el consumo de drogas intravenosas y la coinfecció non por el VIH. La ejecución de programas integrados de atención de la TB dirigidos a las personas sin hogar y con domicilio, que comporten medidas específicas que aborden sus características particulares, podrıa contribuir a la eliminación de la TB en PortugalStudy Group for Infectious Diseases of Instituto de Saúde Púublica da Universidade do Porto who collaborated on this project: B Miranda, C Carvalho, C Matos, C Carvalho, G Rodrigues, J Goncalves, L Maio and T Rito. This work was supported by contributions from Iceland, Liechtenstein and Norway through the European Economic Area Grants under the Public Health Initiatives Programme (PT 06, grant number 138DT1). RG was also partially supported by Centro de Matemática da Universidade do Porto (UID/MAT/00144/2013), which is funded by Fundação do Ministério de Ciência e Tecnologia(Portugal) with national (MEC) and European structural funds (Fonds europeen de d ́eveloppement economique et regional) under the PT2020 Partnership Agreementinfo:eu-repo/semantics/publishedVersio

    Stellar parameters for stars of the CoRoT exoplanet field

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    Aims:To support the computation and evolutionary interpretation of periods associated with the rotational modulation, oscillations, and variability of stars located in the CoRoT fields, we are conducting a spectroscopic survey for stars located in the fields already observed by the satellite. These observations allow us to compute physical and chemical parameters for our stellar sample. Method: Using spectroscopic observations obtained with UVES/VLT and Hydra/Blanco, and based on standard analysis techniques, we computed physical and chemical parameters (TeffT_{\rm{eff}}, log(g)\log \,(g), [Fe/H]\rm{[Fe/H]}, vmicv_{\rm{mic}}, vradv_{\rm{rad}}, vsin(i)v \sin \,(i), and A(Li)A(\rm{Li})) for a large sample of CoRoT targets. Results: We provide physical and chemical parameters for a sample comprised of 138 CoRoT targets. Our analysis shows the stars in our sample are located in different evolutionary stages, ranging from the main sequence to the red giant branch, and range in spectral type from F to K. The physical and chemical properties for the stellar sample are in agreement with typical values reported for FGK stars. However, we report three stars presenting abnormal lithium behavior in the CoRoT fields. These parameters allow us to properly characterize the intrinsic properties of the stars in these fields. Our results reveal important differences in the distributions of metallicity, TeffT_{\rm eff}, and evolutionary status for stars belonging to different CoRoT fields, in agreement with results obtained independently from ground-based photometric surveys. Conclusions: Our spectroscopic catalog, by providing much-needed spectroscopic information for a large sample of CoRoT targets, will be of key importance for the successful accomplishment of several different programs related to the CoRoT mission, thus it will help further boost the scientific return associated with this space mission.Comment: 43 pages, 17 figures, accepted for publication in A&

    Identification of a mosaic non-inherited small supernumerary ring chromosome 2: cytogenetic-molecular studies and genotype-phenotype correlation

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    Introduction: The identification of supernumerary marker chromosomes (SMCs) derived from all the autosomes is currently possible, but rarely by conventional cytogenetics alone. Supernumerary ring chromosomes (SRCs) account for about 10% of these cases. SRCs derived from chromosome 2 are unusual, and there are only a few cases reported in the literature. The severity of the phenotype depends on the type of the mosaicism, the percentage of cells affected by the genetic change and the chromosome involved. Methods: The authors report the case of a boy aged 8 referred for cytogenetic studies, presenting with behavior and learning problems, mental retardation with uncoordenated speech, attention deficit and hyperactivity (PHDA), as well as small slanting palpebral fissures. The karyotype was obtained from peripheral blood lymphocyte cultures using high resolution GTL banding and standard techniques. Fluorescence in situ hybridization (FISH) was performed using specific probes for the centromeric regions of all chromosomes (Chromoprobe Multiprobe - ISystem). Results: Cytogenetic analysis revealed two cell lines: one with a supernumerary marker ring chromosome, 47,XY,+r (52%), and a normal cell line, 46,XY (48%). The SRC was identified by FISH with the chromosome 2 centromeric probe. Since the parents had normal karyotypes, this abnormality was “de novo”. Final karyotype of the proband was: mos 47,XY,+r[26]/46,XY[24].ish r(2)(D2Z2+)dn. Discussion: The clinical description of this patient is in agreement with other reports of the literature. Molecular characterization by FISH analyses is an useful way of investigating the presence of euchromatin contained in a SMC and establishing new chromosomal syndromes. However, to better characterize this ring, in order to establish a more accurate genotype-phenotype correlation, more studies involving other technologies should be performed, thus allowing suitable genetic counsellin

    Plantios de enriquecimento em florestas de produção no Acre.

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    Por meio de procedimentos e técnicas de restauração que considerem a escolha apropriada das espécies (principalmente quanto às características econômicas e ambientais), florestas exauridas de espécies comerciais podem ser conduzidas de maneira a reverter, ou minimizar, os efeitos da exploração seletiva que modificou sua estrutura original. Além disso, é fundamental que a condução posterior aos procedimentos de restauração seja feita de modo a garantir a sustentabilidade das espécies em florestas de produção. Este trabalho objetiva descrever os métodos utilizados, as etapas iniciais de implantação, a definição de espécies aptas e os resultados preliminares de plantios de enriquecimento com espécies florestais madeireiras de alto valor comercial em áreas de florestas destinadas à produção sustentável (manejo florestal) localizadas nos municípios de Xapuri, Brasileia e Rio Branco, no Estado do Acre. As ações aqui descritas são componentes de um projeto de pesquisa conduzido pela Embrapa Acre que tem como principal objetivo desenvolver procedimentos técnicos voltados à mitigação dos processos de escasseamento e ameaça de espécies madeireiras importantes por meio da restauração florestal. Tais procedimentos se destinam à transferência ao público afim, em especial, ao setor produtivo florestal do Acre e região.bitstream/item/99025/1/24929.PD
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