Hydrogen evolution on a pseudomorphic Cu-layer on Ni(111) - a theoretical study

Hydrogen evolution on a monolayer of copper on Ni(1 1 1) has been investigated by a combination of density functional theory and a model developed in our own group. The lattice constant of nickel is only about 2.5% shorter than that of copper; therefore the nickel substrate has only a minor effect on the surface d band of the adsorbed copper. However, there is a strong chemical effect which enhances the interaction of hydrogen with the Cu/Ni(1 1 1) surface as compared to Cu(1 1 1). Consequently, the adlayer promises to be a cheap catalyst that is significantly better than pure copper.Fil: Santos, Elizabeth del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Quaino, Paola Monica. Ulm University; Alemania. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Hindelang, Peter F.. Ulm University; AlemaniaFil: Schmickler, Wolfgang. Ulm University; Alemani

Two Distinct Pathways Leading to Nuclear Apoptosis

Apaf-1−/− or caspase-3−/− cells treated with a variety of apoptosis inducers manifest apoptosis-associated alterations including the translocation of apoptosis-inducing factor (AIF) from mitochondria to nuclei, large scale DNA fragmentation, and initial chromatin condensation (stage I). However, when compared with normal control cells, Apaf-1−/− or caspase-3−/− cells fail to exhibit oligonucleosomal chromatin digestion and a more advanced pattern of chromatin condensation (stage II). Microinjection of such cells with recombinant AIF only causes peripheral chromatin condensation (stage I), whereas microinjection with activated caspase-3 or its downstream target caspase-activated DNAse (CAD) causes a more pronounced type of chromatin condensation (stage II). Similarly, when added to purified HeLa nuclei, AIF causes stage I chromatin condensation and large-scale DNA fragmentation, whereas CAD induces stage II chromatin condensation and oligonucleosomal DNA degradation. Furthermore, in a cell-free system, concomitant neutralization of AIF and CAD is required to suppress the nuclear DNA loss caused by cytoplasmic extracts from apoptotic wild-type cells. In contrast, AIF depletion alone suffices to suppress the nuclear DNA loss contained in extracts from apoptotic Apaf-1−/− or caspase-3−/− cells. As a result, at least two redundant parallel pathways may lead to chromatin processing during apoptosis. One of these pathways involves Apaf-1 and caspases, as well as CAD, and leads to oligonucleosomal DNA fragmentation and advanced chromatin condensation. The other pathway, which is caspase-independent, involves AIF and leads to large-scale DNA fragmentation and peripheral chromatin condensation

Estudo de seguimento por dois anos de idosos residentes em São Paulo, Brasil: metodologia e resultados preliminares

INTRODUCTION: Previous cross-sectional studies have shown a high prevalence of chronic disease and disability among the elderly. Given Brazil s rapid aging process and the obvious consequences of the growing number of old people with chronic diseases and associated disabilities for the provision of health services, a need was felt for a study that would overcome the limitations of cross-sectional data and shed some light on the main factors determining whether a person will live longer and free of disabling diseases, the so-called successful aging. The methodology of the first follow-up study of elderly residents in Brazil is presented. METHOD: The profile of the initial cohort is compared with previous cross-sectional data and an in-depth analysis of nonresponse is carried out in order to assess the validity of future longitudinal analysis. The EPIDOSO ( Epidemiologia do Idoso ) Study conducted a two-year follow-up of 1,667 elderly people (65+), living in S. Paulo. The study consisted of two waves, each consisting of household, clinical, and biochemical surveys. RESULTS AND CONCLUSIONS: In general, the initial cohort showed a similar profile to previous cross-sectional samples in S. Paulo. There was a majority of women, mostly widows, living in multigenerational households, and a high prevalence of chronic illnesses, psychiatric disturbances, and physical disabilities. Despite all the difficulties inherent in follow-up studies, there was a fairly low rate of nonresponse to the household survey after two years, which did not actually affect the representation of the cohort at the final household assessment, making unbiased longitudinal analysis possible. Concerning the clinical and blood sampling surveys, the respondents tended to be younger and less disabled than the nonrespondents, limiting the use of the clinical and laboratory data to longitudinal analysis aimed at a healthier cohort. It is worth mentioning that gender, education, family support, and socioeconomic status were not important determinants of nonresponse, as is often the case.INTRODUÇÃO: Estudos transversais recentes mostraram alta prevalência de doenças crônicas e incapacidades físicas entre idosos. Considerando o rápido processo de envelhecimento do Brasil e as conseqüências que esse aumento de idosos com doenças crônicas e incapacidades associadas acarretará para o sistema de saúde, fazia-se necessário estudo que pudesse superar as limitações dos dados transversais, permitindo determinar quais os fatores determinantes de uma vida longa e livre de doenças incapacitantes, o chamado envelhecimento bem sucedido. É apresentada a metodologia do primeiro estudo epidemiológico longitudinal com idosos residentes na comunidade, no Brasil. MÉTODO: O perfil do cohorte inicial é comparado com dados de estudos anteriores a com o perfil dos não respondentes para avaliar a validade de análises longitudinais futuras.O projeto EPIDOSO (Epidemiologia do Idoso) seguiu por dois anos 1.667 idosos (65+), residentes em São Paulo. Consistiu de duas ondas, cada qual com três inquéritos: domiciliar, clínico e laboratorial. RESULTADOS E CONCLUSÕES: O perfil da população não diferiu de estudos anteriores, mostrando maioria de mulheres, viúvas, vivendo em domicílios multigeracionais, com uma alta prevalência de doenças crônicas, distúrbios psiquiátricos e incapacidades físicas. A despeito de todas as dificuldades inerentes a um estudo longitudinal, o grupo de não-respondentes ao segundo inquérito domiciliar não diferiu significativamente dos respondentes, assegurando análises longitudinais livres desse tipo de viés. Em relação aos inquéritos clínico e laboratorial, os não-respondentes mostraram-se mais velhos e mais incapacitados que os respondentes, limitando o uso dos dados clínicos e laboratoriais a análises pertinentes a uma cohorte mais jovem e saudável. Sexo, educação, apoio familiar e nível socioeconômico não influenciaram de forma significativa a taxa de não - resposta, ao contrário do que se costuma verificar.Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Miopatía por cuerpos de inclusión. Caso clínico y revisión de la literatura

La miositis por cuerpos de inclusión (MCI) es una patología poco común que se presenta en individuos mayores de 50 años y con mayor frecuencia en hombres; sin embargo, los síntomas pueden empezar 20 años antes de su diagnóstico. Hasta un 30% de los casos de miopatías inflamatorias pueden ser de MCI y su prevalencia varía en los diferentes países y grupos étnicos. Clínicamente se manifiesta como debilidad lentamente progresiva proximal y distal. En este artículo se presenta un caso de una paciente de 78 años con antecedentes previos de diabetes mellitus tipo 2, hipertensión arterial, e hipotiroidismo, con cuadro de 18 meses de evolución consistente en debilidad de miembros inferiores, incapacidad para subir y bajar escaleras, limitación en la marcha, acompañado de disestesias. Se realizó la medición de la creatin quinasa (CK) y su valor inicial fue 7820, la electromiografía y neuroconducciones mostraron polineuropatia axonal motora en las cuatro extremidades y miopatía inflamatoria. Se trató con glucorticoides a dosis de 1 mg/kg y después de seis meses de tratamiento no se observó mejoría. Se decide tomar biopsia muscular que mostró miopatía por cuerpos de inclusión, lo que explicó la falla terapéutica inicial. Este caso es interesante desde el punto de vista clínico, ya que no es frecuente la elevación de la CK en los niveles que presentó la paciente y por las múltiples comorbilidades asociadas

Effect of artesunate-mefloquine fixed-dose combination in malaria transmission in amazon basin communities

Background: Studies in South-East Asia have suggested that early diagnosis and treatment with artesunate (AS) and mefloquine (MQ) combination therapy may reduce the transmission of Plasmodium falciparum malaria and the progression of MQ resistance. Methods: The effectiveness of a fixed-dose combination of AS and MQ (ASMQ) in reducing malaria transmission was tested in isolated communities of the Jurua valley in the Amazon region. Priority municipalities within the Brazilian Legal Amazon area were selected according to pre-specified criteria. Routine national malaria control programmatic procedures were followed. Existing health structures were reinforced and health care workers were trained to treat with ASMQ all confirmed falciparum malaria cases that match inclusion criteria. A local pharmacovigilance structure was implemented. Incidence of malaria and hospitalizations were recorded two years before, during, and after the fixed-dose ASMQ intervention. In total, between July 2006 and December 2008, 23,845 patients received ASMQ. Two statistical modelling approaches were applied to monthly time series of P. falciparum malaria incidence rates, P. falciparum/Plasmodium vivax infection ratio, and malaria hospital admissions rates. All the time series ranged from January 2004 to December 2008, whilst the intervention period span from July 2006 to December 2008. Results: The ASMQ intervention had a highly significant impact on the mean level of each time series, adjusted for trend and season, of 0.34 (95% CI 0.20 - 0.58) for the P. falciparum malaria incidence rates, 0.67 (95% CI 0.50 - 0.89) for the P. falciparum/P. vivax infection ratio, and 0.53 (95% CI 0.41 - 0.69) for the hospital admission rates. There was also a significant change in the seasonal (or monthly) pattern of the time series before and after intervention, with the elimination of the malaria seasonal peak in the rainy months of the years following the introduction of ASMQ. No serious adverse events relating to the use of fixed-dose ASMQ were reported. Conclusions: In the remote region of the Jurua valley, the early detection of malaria by health care workers and treatment with fixed-dose ASMQ was feasible and efficacious, and significantly reduced the incidence and morbidity of P. falciparum malaria.CNPq [309156/2007-6]PAHO/WHOBrazilian Ministry of HealthUSAI

How has the COVID-19 crisis affected the academic stress of university students? The role of teachers and students

The effects of the COVID-19 pandemic have required substantial adjustments in terms of university teaching¿learning processes. The aim of this study was to verify whether there were significant differences between the academic year of 2020 and the two preceding years in factors and symptoms and stress. A total of 642 university students (ages 18¿25 years) participated by filling out validated self-reports during the months from March to August 2020. Using an ex post facto design, SEM analyses and simple and multiple ANOVAs were performed. Structural results showed that stress factors from the teaching process had a predictive value for the learning process, emotions, and academic burnout, and being a man was a factor predicting negative emotion. In a similar way, inferential results revealed no significant effect of academic year but did show an effect of gender on stress experiences during the pandemic. Aside from certain specific aspects, there was no significant global effect of the year 2020 on factors and symptoms of stress. The results showed that studying in the year of the COVID-19 outbreak did not have a significant effect on stress triggered by the teaching process. From these results, we draw implications for specific guidance interventions with university teachers and students

In vitro and in vivo safety evaluation of Dipteryx alata Vogel extract

<p>Abstract</p> <p>Background</p> <p><it>Dipteryx alata </it>Vogel popularly known as "baru" is an important commercial leguminous tree species from the Brazilian Cerrado, which possess medicinal properties, besides its fruits consumption by animals and humans. The use of the "naturally occurring plants" as herbal remedies and foods mainly from leaves, seeds, flowers and roots of plants or extracts require precautions before ensuring these are safe and efficacious. The objective of this study was to evaluate the safety of <it>D. alata </it>barks extract.</p> <p>Methods</p> <p>Vegetal drugs of <it>D. alata </it>barks were submitted to quality control assays and further to the safety assays under 1) <it>in vitro </it>parameter by <it>Salmonella </it>(Ames) mutagenicity, and 2) <it>in vivo </it>parameter on the pregnancy of rats.</p> <p>Results</p> <p>The extract was non-mutagenic to any of the assessed strains TA97a, TA98, TA100 and TA102 even after metabolic activation (+S9). All <it>in vivo </it>parameters (reproductive ability evaluation, physical development of rat offsprings, and neurobehavioral development assays) showed no changes related to control group.</p> <p>Conclusion</p> <p><it>D. alata </it>barks extract is neither mutagenic by the Ames test nor toxic in the pregnancy of rats, with no physical-neurobehavioral consequences on the rat offsprings development.</p

p53 Transactivation and the Impact of Mutations, Cofactors and Small Molecules Using a Simplified Yeast-Based Screening System

The p53 tumor suppressor, which is altered in most cancers, is a sequence-specific transcription factor that is able to modulate the expression of many target genes and influence a variety of cellular pathways. Inactivation of the p53 pathway in cancer frequently occurs through the expression of mutant p53 protein. In tumors that retain wild type p53, the pathway can be altered by upstream modulators, particularly the p53 negative regulators MDM2 and MDM4. promoter, ii) single copy, chromosomally located p53-responsive and control luminescence reporters, iii) enhanced chemical uptake using modified ABC-transporters, iv) small-volume formats for treatment and dual-luciferase assays, and v) opportunities to co-express p53 with other cofactor proteins. This robust system can distinguish different levels of expression of WT and mutant p53 as well as interactions with MDM2 or 53BP1.We found that the small molecules Nutlin and RITA could both relieve the MDM2-dependent inhibition of WT p53 transactivation function, while only RITA could impact p53/53BP1 functional interactions. PRIMA-1 was ineffective in modifying the transactivation capacity of WT p53 and missense p53 mutations. This dual-luciferase assay can, therefore, provide a high-throughput assessment tool for investigating a matrix of factors that can influence the p53 network, including the effectiveness of newly developed small molecules, on WT and tumor-associated p53 mutants as well as interacting proteins

Admixture in Latin America: Geographic Structure, Phenotypic Diversity and Self-Perception of Ancestry Based on 7,342 Individuals

The current genetic makeup of Latin America has been shaped by a history of extensive admixture between Africans, Europeans and Native Americans, a process taking place within the context of extensive geographic and social stratification. We estimated individual ancestry proportions in a sample of 7,342 subjects ascertained in five countries (Brazil, Chile, Colombia, México and Perú). These individuals were also characterized for a range of physical appearance traits and for self-perception of ancestry. The geographic distribution of admixture proportions in this sample reveals extensive population structure, illustrating the continuing impact of demographic history on the genetic diversity of Latin America. Significant ancestry effects were detected for most phenotypes studied. However, ancestry generally explains only a modest proportion of total phenotypic variation. Genetically estimated and self-perceived ancestry correlate significantly, but certain physical attributes have a strong impact on self-perception and bias self-perception of ancestry relative to genetically estimated ancestry