Hyperfine magnetic field in ferromagnetic graphite

Information on atomic-scale features is required for a better understanding of the mechanisms leading to magnetism in non-metallic, carbon-based materials. This work reports a direct evaluation of the hyperfine magnetic field produced at 13C nuclei in ferromagnetic graphite by nuclear magnetic resonance (NMR). The experimental investigation was made possible by the results of first-principles calculations carried out in model systems, including graphene sheets with atomic vacancies and graphite nanoribbons with edge sites partially passivated by oxygen. A similar range of maximum hyperfine magnetic field values (18-21T) was found for all systems, setting the frequency span to be investigated in the NMR experiments; accordingly, a significant 13C NMR signal was detected close to this range without any external applied magnetic field in ferromagnetic graphite

S6Ks isoforms contribute to viability, migration, docetaxel resistance and tumor formation of prostate cancer cells

Background: The S6 Kinase (S6K) proteins are some of the main downstream effectors of the mammalian Target Of Rapamycin (mTOR) and act as key regulators of protein synthesis and cell growth. S6K is overexpressed in a variety of human tumors and is correlated to poor prognosis in prostate cancer. Due to the current urgency to identify factors involved in prostate cancer progression, we aimed to reveal the cellular functions of three S6K isoforms-p70-S6K1, p85-S6K1 and p54-S6K2-in prostate cancer, as well as their potential as therapeutic targets. Methods: In this study we performed S6K knockdown and overexpression and investigated its role in prostate cancer cell proliferation, colony formation, viability, migration and resistance to docetaxel treatment. In addition, we measured tumor growth in Nude mice injected with PC3 cells overexpressing S6K isoforms and tested the efficacy of a new available S6K1 inhibitor in vitro. Results: S6Ks overexpression enhanced PC3-luc cell line viability, migration, resistance to docetaxel and tumor formation in Nude mice. Only S6K2 knockdown rendered prostate cancer cells more sensitive to docetaxel. S6K1 inhibitor PF-4708671 was particularly effective for reducing migration and proliferation of PC3 cell line. Conclusions: These findings demonstrate that S6Ks play an important role in prostate cancer progression, enhancing cell viability, migration and chemotherapy resistance, and place both S6K1 and S6K2 as a potential targets in advanced prostate cancer. We also provide evidence that S6K1 inhibitor PF-4708671 may be considered as a potential drug for prostate cancer treatment16CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação2012/13558-

Mild Systemic Oxidative Stress in the Subclinical Stage of Alzheimer's Disease

Alzheimer's disease (AD) is a late-onset, progressive degenerative disorder that affects mainly the judgment, emotional stability, and memory domains. AD is the outcome of a complex interaction among several factors which are not fully understood yet; nevertheless, it is clear that oxidative stress and inflammatory pathways are among these factors. 65 elderly subjects (42 cognitively intact and 23 with probable Alzheimer's disease) were selected for this study. We evaluated erythrocyte activities of superoxide dismutase, catalase, and glutathione peroxidase as well as plasma levels of total glutathione, alpha-tocopherol, beta-carotene, lycopene, and coenzyme Q10. These antioxidant parameters were confronted with plasmatic levels of protein and lipid oxidation products. Additionally, we measured basal expression of monocyte HLA-DR and CD-11b, as well as monocyte production of cytokines IL1-alpha, IL-6, and TNF-alpha. AD patients presented lower plasmatic levels of alpha-tocopherol when compared to control ones and also higher basal monocyte HLA-DR expression associated with higher IL-1 alpha production when stimulated by LPS. These findings support the inflammatory theory of AD and point out that this disease is associated with a higher basal activation of circulating monocytes that may be a result of alpha-tocopherol stock depletion.Univ São Paulo, Inst Quim, BR-05508900 São Paulo, BrazilUNIFESP, Inst Ciencias Ambientais Quim Farmaceut, BR-09972270 Diadema, SP, BrazilFMABC, Dept Hematol & Oncol, BR-09060650 Santo Andre, SP, BrazilUniversidade Federal de São Paulo, Dept Med, BR-04021001 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med Prevent, BR-04021001 São Paulo, BrazilUNIFESP, Inst Ciencias Ambientais Quim Farmaceut, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, Dept Med, BR-04021001 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med Prevent, BR-04021001 São Paulo, BrazilWeb of Scienc

An ant colony-based semi-supervised approach for learning classification rules

Semi-supervised learning methods create models from a few labeled instances and a great number of unlabeled instances. They appear as a good option in scenarios where there is a lot of unlabeled data and the process of labeling instances is expensive, such as those where most Web applications stand. This paper proposes a semi-supervised self-training algorithm called Ant-Labeler. Self-training algorithms take advantage of supervised learning algorithms to iteratively learn a model from the labeled instances and then use this model to classify unlabeled instances. The instances that receive labels with high confidence are moved from the unlabeled to the labeled set, and this process is repeated until a stopping criteria is met, such as labeling all unlabeled instances. Ant-Labeler uses an ACO algorithm as the supervised learning method in the self-training procedure to generate interpretable rule-based models—used as an ensemble to ensure accurate predictions. The pheromone matrix is reused across different executions of the ACO algorithm to avoid rebuilding the models from scratch every time the labeled set is updated. Results showed that the proposed algorithm obtains better predictive accuracy than three state-of-the-art algorithms in roughly half of the datasets on which it was tested, and the smaller the number of labeled instances, the better the Ant-Labeler performance

Simulaçao numérica da dispersao de poluentes emitidos por incendios no verao de 2003 na Peninsula Ibérica

Ponencia presentada en: XXIX Jornadas Científicas de la AME y el VII Encuentro Hispano Luso de Meteorología celebrado en Pamplona, del 24 al 26 de abril de 2006.[PT]O objectivo deste trabalho é utilizar o modelo CATT-B-RAMS (Coupled Aerosol and Tracers Transport model to the Brazilian Regional Atmospheric Modeling System) para estudar o transporte atmosférico do monóxido de carbono (CO) e material particulado (PM2.5) emitidos por queimadas que ocorreram durante o Verão de 2003 na Península Ibérica, no período de 31 de Julho a 3 de Agosto com a situação sinóptica actuante na exportação destes poluentes. As simulações numéricas foram feitas com a assimilação dos dados de fogos derivados a partir de medidas do MODIS/AQUA para a Europa para implementar a posição da emissão. Para a caracterização do estado inicial do modelo foram usadas as análises do modelo global AVN/NCEP (Aviation run of the National Center for Environmental Prediction Global Spectral Model) com grade de resolução de 80 km. Os resultados indicam que o modelo de mesoescala pode ser uma boa ferramenta para descrever a circulação atmosférica reproduzindo as principais características da situação sinóptica e o entendimento e avaliação deste impacto, passam necessariamente, pela junção de estudos observacionais e modelação numérica gerando modelos complexos que descrevam as inter-relações biosfera-atmosfera, caracterizando um estudo multidisciplinar.[EN]This study presents the transport of gases and particulate emitted by large scale vegetation fires that took place in the Iberian Peninsula in summer of 2003. This study is carried out through a numerical simulation using a highresolution configuration of the 3-D transport model CATT-BRAMS (Coupled Aerosol and Tracer Transport to the Brazilian developments on the Regional Atmospheric Modeling System) coupled to a biomass burning emission model. The sources emission from biomass burning for carbon monoxide (CO) and particulate material (PM2.5) are defined using MODIS/TERRA fire product and local observations. The initial and lateral boundary conditions necessary to drive model were provided by the Aviation run of the National Center for Environmental Prediction Global Spectral Model (AVN/NCEP). The coarse grid resolution was defined with 80 km grid spacing. The results show that the mesoscale model can be used as a useful tool to describe the atmospheric circulation reproducing the main characteristics of the synoptic situation and how it controls the pollution transport

Infertilidade masculina

Between 10 to 15% of couples can be unsuccessful at trying to have children after one year of unprotected sexual intercourse. About 50% of cases of infertility are related to male infertility. The cause of male infertility, in turn, is frequently associated with sperm alterations. Traditionally, male infertility has been considered as a condition that is difficult to be treated. New studies in the field of Genetics have presented findings of deletion or mutation in groups of genes that could have a causal relation to infertility in male patients. Most advancements in the treatment of male infertility are in the area of assisted reproduction, which, in turn, has developed following the progress in technologies of gamete micromanipulation. Our study is aimed at assessing causes of, and treatment for male infertility. Entre 10 a 15% dos casais falham em ter filhos após um ano de intercursos sexuais não protegidos. Cerca de 50% das causas de infertilidade são de origem masculina. Como causa simples de infertilidade, alterações espermáticas são a condição mais freqüente. A infertilidade de causa masculina foi tradicionalmente considerada como uma condição de difícil tratamento. Novos estudos na área da genética têm encontrado deleções ou mutações em grupos de genes que poderiam explicar a infertilidade nesses pacientes. A maior parte dos avanços no tratamento destes casos reside nas técnicas de reprodução assistida, que tiveram seu maior avanço após o desenvolvimento da tecnologia da micromanipulação de gametas. O presente trabalho faz uma análise de causas e de tratamentos para dar solução à infertilidade masculina.

Stage at presentation of breast cancer in Luanda, Angola - a retrospective study

Background: It is expected that, by 2020, 15 million new cases of cancer will occur every year in the world, one million of them in Africa. Knowledge of cancer trends in African countries is far from adequate, and improvements in cancer prevention efforts are urgently needed. The aim of this study was to characterize breast cancer clinically and pathologically at presentation in Luanda, Angola; we additionally provide quality information that will be useful for breast cancer care planning in the country. Methods: Data on breast cancer cases were retrieved from the Angolan Institute of Cancer Control, from 2006 to 2014. For women diagnosed in 2009 (5-years of follow-up), demographic, clinical and pathological information, at presentation, was collected, namely age at diagnosis, parity, methods used for pathological diagnoses, tumor pathological characteristics, stage of disease and treatment. Descriptive statistics were performed. Results: The median age of women diagnosed with breast cancer in 2009 was 47 years old (range 25–89). The most frequent clinical presentation was breast swelling with axillary lymph nodes metastasis (44.9 %), followed by a mass larger than 5 cm (14.2 %) and lump (12.9 %). Invasive ductal carcinoma was the main histologic type (81.8 %). Only 10.1 % of cancer cases had a well differentiated histological grade. Cancers were diagnosed mostly at advanced stages (66.7 % in stage III and 11.1 % in stage IV). Discussion: In this study, breast cancer was diagnosed at a very advanced stage. Although it reports data from a single cancer center in Luanda, Angola it reinforces the need for early diagnosis and increasing awareness. According to the main challenges related to breast cancer diagnosis and treatment herein presented, we propose a realistic framework that would allow for the implementation of a breast cancer care program, built under a strong network based on cooperation, teaching, audit, good practices and the organization of health services. Conclusion: Angola needs urgently a program for early diagnosis of breast cancer.We thank Susana Santos for correction of the article in English language, and a Cancer Registry Staff from IACC, particularly Pedro Luis Hernandez Gonzalez, Paulo Ernesto Alves, Xacu Parica and Alberto Sivi Lutumba for their support in data acquisition. We also thank SEMED -Portugal in support for publication

Computer Simulations of Hippocampal Mossy Fiber Cleft Zinc Movements

Zinc ions have key regulatory, structural, and catalytic functions and mediate a variety of intra- and intercellular processes. The hippocampal mossy fiber boutons contain large amounts of free or loosely bound vesicular zinc, which can be co-released with glutamate. Zinc can interact with a variety of ionic channels (N-VDCCs, L-VDCCs, KATP), glutamate receptors (AMPA, KA, NMDA 2A, 2B), glutamate transporters (GLAST, EAAT4), and molecules (ATP). The dynamic properties of cleft free, complexed, and total zinc were addressed, considering the known concentration and affinity of various cleft zinc sensitive sites, mainly in the postsynaptic area and in glial cells. The computer model included three different zinc release processes, with short, medium, and long duration, described, like the uptake ones, by alpha functions. The results suggest that, depending on the amount of release, zinc clearance is largely due, either, to zinc binding to NMDA 2A receptor sites or to glial GLAST transporters