Ligand K-edge X-ray absorption spectroscopy and DFT calculations on [Fe3S4]0,+ clusters: delocalization, redox, and effect of the protein environment

Ligand K-edge XAS of an [Fe3S4]0 model complex is reported. The pre-edge can be resolved into contributions from the í2Ssulfide, í3Ssulfide, and Sthiolate ligands. The average ligand-metal bond covalencies obtained from these pre-edges are further distributed between Fe3+ and Fe2.5+ components using DFT calculations. The bridging ligand covalency in the [Fe2S2]+ subsite of the [Fe3S4]0 cluster is found to be significantly lower than its value in a reduced [Fe2S2] cluster (38% vs 61%, respectively). This lowered bridging ligand covalency reduces the superexchange coupling parameter J relative to its value in a reduced [Fe2S2]+ site (-146 cm-1 vs -360 cm-1, respectively). This decrease in J, along with estimates of the double exchange parameter B and vibronic coupling parameter ì2/k-, leads to an S ) 2 delocalized ground state in the [Fe3S4]0 cluster. The S K-edge XAS of the protein ferredoxin II (Fd II) from the D. gigas active site shows a decrease in covalency compared to the model complex, in the same oxidation state, which correlates with the number of H-bonding interactions to specific sulfur ligands present in the active site. The changes in ligand-metal bond covalencies upon redox compared with DFT calculations indicate that the redox reaction involves a two-electron change (one-electron ionization plus a spin change of a second electron) with significant electronic relaxation. The presence of the redox inactive Fe3+ center is found to decrease the barrier of the redox process in the [Fe3S4] cluster due to its strong antiferromagnetic coupling with the redox active Fe2S2 subsite

Ocorrência de violência intrafamiliar relacionada ao consumo de álcool e outras drogas no Brasil

The objective of this study was to analyze the brazilian scientific production about the relationship between alcohol consumption and other drugs (AD) and the occurrence of intra-family violence (domestic violence). Integrative review, using all databases included in the Virtual Health Library, selecting articles published between 2013 and 2019, in portuguese, available in full electronically and with free access. From the 42 selected studies, it was possible to observe an important role in the consumption of alcohol and other drugs in the occurrence of intra-family violence, indicating in most articles the use of alcohol and other drugs as one of the main factors (provoker, influator, motivator, triggering) of intra-family violence. On the other hand, it has also been described that AD consumption may be a consequence of intra-family violence, which may act as a cycle of consumption and reaction, acting as a propellant of use and vice versa, describing the use of AD as important, but not as unique cause for intra-family violence. It was possible to analyze the interference of AD consumption in intra-family violence, with its various members (women, children, adolescents, the elderly) and in various aspects, suggesting that alcohol is the main licit substance involved in the phenomenon of violence, as well as other illicit drugs, even in a lesser proportion, in Brazil. Although violence in the family is multifactorial, it is essential to consider the effect of AD in the occurrence of this aggravation, because they occur simultaneously and share a complex set of risk factors, with serious psychosocioeconomic effects Individually and collectively, requiring intersectoral actions for their coping.Objetivou-se analisar a produção científica brasileira acerca da relação entre o consumo de álcool e de outras drogas (AD) e a ocorrência da violência intrafamiliar (violência na família). Revisão integrativa, utilizando todas as bases de dados incluídas na Biblioteca Virtual em Saúde, selecionando artigos publicados entre 2013 a 2019, em português, disponíveis na íntegra eletronicamente e com acesso gratuito. A partir dos 42 estudos selecionados, foi possível observar um papel importante no consumo de álcool e outras drogas na ocorrência da violência intrafamiliar, indicando na maior parte dos artigos o uso do álcool e de outras drogas como um dos principais fatores (propiciador, influenciador, motivador, desencadeador) da violência intrafamiliar. Em contrapartida, também foi descrito que o consumo AD pode ser consequência da violência intrafamiliar, podendo atuar como um ciclo de consumo e reação, atuando a violência como propulsora do uso e vice-versa, descrevendo o uso de AD como importante, mas não unicausal para a violência intrafamiliar. Foi possível analisar a interferência do consumo de AD na violência intrafamiliar, com seus diversos membros (mulheres, crianças, adolescentes, idosos) e sob vários aspectos, sugerindo que o álcool é a principal substância lícita envolvida no fenômeno da violência, assim como outras drogas ilícitas, mesmo que em menor proporção, no Brasil. Apesar da violência na família ser multifatorial, torna-se essencial considerar o efeito do AD na ocorrência deste agravo, pois eles ocorrem simultaneamente e compartilham um conjunto complexo de fatores de risco, com graves efeitos psicosocioeconômicos individuais e coletivamente, requerendo ações intersetoriais para seu enfrentamento

Elliptic flow from two- and four-particle correlations in Au + Au collisions at sqrt{s_{NN}} = 130 GeV

Elliptic flow holds much promise for studying the early-time thermalization attained in ultrarelativistic nuclear collisions. Flow measurements also provide a means of distinguishing between hydrodynamic models and calculations which approach the low density (dilute gas) limit. Among the effects that can complicate the interpretation of elliptic flow measurements are azimuthal correlations that are unrelated to the reaction plane (non-flow correlations). Using data for Au + Au collisions at sqrt{s_{NN}} = 130 GeV from the STAR TPC, it is found that four-particle correlation analyses can reliably separate flow and non-flow correlation signals. The latter account for on average about 15% of the observed second-harmonic azimuthal correlation, with the largest relative contribution for the most peripheral and the most central collisions. The results are also corrected for the effect of flow variations within centrality bins. This effect is negligible for all but the most central bin, where the correction to the elliptic flow is about a factor of two. A simple new method for two-particle flow analysis based on scalar products is described. An analysis based on the distribution of the magnitude of the flow vector is also described.Comment: minor text change

Entamoeba lysyl-tRNA Synthetase Contains a Cytokine-Like Domain with Chemokine Activity towards Human Endothelial Cells

Immunological pressure encountered by protozoan parasites drives the selection of strategies to modulate or avoid the immune responses of their hosts. Here we show that the parasite Entamoeba histolytica has evolved a chemokine that mimics the sequence, structure, and function of the human cytokine HsEMAPII (Homo sapiens endothelial monocyte activating polypeptide II). This Entamoeba EMAPII-like polypeptide (EELP) is translated as a domain attached to two different aminoacyl-tRNA synthetases (aaRS) that are overexpressed when parasites are exposed to inflammatory signals. EELP is dispensable for the tRNA aminoacylation activity of the enzymes that harbor it, and it is cleaved from them by Entamoeba proteases to generate a standalone cytokine. Isolated EELP acts as a chemoattractant for human cells, but its cell specificity is different from that of HsEMAPII. We show that cell specificity differences between HsEMAPII and EELP can be swapped by site directed mutagenesis of only two residues in the cytokines' signal sequence. Thus, Entamoeba has evolved a functional mimic of an aaRS-associated human cytokine with modified cell specificity

The Promigratory Activity of the Matricellular Protein Galectin-3 Depends on the Activation of PI-3 Kinase

Expression of galectin-3 is associated with sarcoma progression, invasion and metastasis. Here we determined the role of extracellular galectin-3 on migration of sarcoma cells on laminin-111. Cell lines from methylcholanthrene-induced sarcomas from both wild type and galectin-3−/− mice were established. Despite the presence of similar levels of laminin-binding integrins on the cell surface, galectin-3−/− sarcoma cells were more adherent and less migratory than galectin-3+/+ sarcoma cells on laminin-111. When galectin-3 was transiently expressed in galectin-3−/− sarcoma cells, it inhibited cell adhesion and stimulated the migratory response to laminin in a carbohydrate-dependent manner. Extracellular galectin-3 led to the recruitment of SHP-2 phosphatase to focal adhesion plaques, followed by a decrease in the amount of phosphorylated FAK and phospho-paxillin in the lamellipodia of migrating cells. The promigratory activity of extracellular galectin-3 was inhibitable by wortmannin, implicating the activation of a PI-3 kinase dependent pathway in the galectin-3 triggered disruption of adhesion plaques, leading to sarcoma cell migration on laminin-111

Global Mortality Estimates for the 2009 Influenza Pandemic from the GLaMOR Project: A Modeling Study

Background: Assessing the mortality impact of the 2009 influenza A H1N1 virus (H1N1pdm09) is essential for optimizing public health responses to future pandemics. The World Health Organization reported 18,631 laboratory-confirmed pandemic deaths, but the total pandemic mortality burden was substantially higher. We estimated the 2009 pandemic mortality burden through statistical modeling of mortality data from multiple countries. Methods and Findings: We obtained weekly virology and underlying cause-of-death mortality time series for 2005–2009 for 20 countries covering ~35% of the world population. We applied a multivariate linear regression model to estimate pandemic respiratory mortality in each collaborating country. We then used these results plus ten country indicators in a multiple imputation model to project the mortality burden in all world countries. Between 123,000 and 203,000 pandemic respiratory deaths were estimated globally for the last 9 mo of 2009. The majority (62%–85%) were attributed to persons under 65 y of age. We observed a striking regional heterogeneity, with almost 20-fold higher mortality in some countries in the Americas than in Europe. The model attributed 148,000–249,000 respiratory deaths to influenza in an average pre-pandemic season, with only 19% in person