Exploring Electrophilic Hydrophosphination via Metal Phosphenium Intermediates.

Two Mo(0) phosphenium complexes containing ancillary secondary phosphine ligands have been investigated with respect to their ability to participate in electrophilic addition at unsaturated substrates and subsequent P-H hydride transfer to "quench" the resulting carbocations. These studies provide stoichiometric "proof of concept" for a proposed new metal-catalyzed electrophilic hydrophosphination mechanism. The more strongly Lewis acidic phosphenium complex, [Mo(CO)4(PR2H)(PR2)]+ (R=Ph, Tolp), cleanly hydrophosphinates 1,1-diphenylethylene, benzophenone, and ethylene, while other substrates react rapidly to give products resulting from competing electrophilic processes. A less Lewis acidic complex, [Mo(CO)3(PR2H)2(PR2)]+, generally reacts more slowly but participates in clean hydrophosphination of a wider range of unsaturated substrates, including styrene, indene, 1-hexene, and cyclohexanone, in addition to 1,1-diphenylethylene, benzophenone, and ethylene. Mechanistic studies are described, including stoichiometric control reactions and computational and kinetic analyses, which probe whether the observed P-H addition actually does occur by the proposed electrophilic mechanism, and whether hydridic P-H transfer in this system is intra- or intermolecular. Preliminary reactivity studies indicate challenges that must be addressed to exploit these promising results in catalysis.

Peritoneal Dialysis Exit-Site Care Protocols in Portugal and Its Association with Catheter-Related Infections.

INTRODUCTION: Exit-site infection (ESi) prevention is a key factor in lowering the risk of peritonitis. This study aimed to evaluate the associations between exit-site (ES) care protocols and the annual incidence rates of ESi and peritonitis in Portugal. METHODS: We performed a national survey using two questionnaires: one about the incidence of catheter-related infections and the other characterizing patients' education and ES care protocols. RESULTS: In 2017 and 2018, 14 Portuguese units followed 764 and 689 patients. ESi incidence rate was 0.41 episodes/year, and the peritonitis incidence rate was 0.37. All units monitor catheter-related infections on a yearly basis, use antibiotic prophylaxis at the time of catheter placement, and treat nasal carriage of S. aureus, although with different approaches. Screening for nasal carriage of S. aureus is performed by 12 units, and daily topical antibiotic cream is recommended by 6 out of 14 of the units. We did not find statistical differences in ESi/peritonitis, comparing these practices. The rate of ESis was lower with nonocclusive dressing immediately after catheter insertion, bathing without ES dressing, with the use of colostomy bags in beach baths and was higher with the use of bath sponge. The peritonitis rate was lower with bathing without ES dressing and if shaving of the external cuff was performed in the presence of chronic ESi. CONCLUSIONS: We found potential proceedings associated with ESi and peritonitis. A regular national audit of peritoneal dialysis units is an important tool for clarifying the best procedures for reduction of catheter-related infections.

How abundant are superoxide and hydrogen peroxide in the vasculature lumen, how far can they reach?

Paracrine superoxide (O2•-) and hydrogen peroxide (H2O2) signaling critically depends on these substances' concentrations, half-lives and transport ranges in extracellular media. Here we estimated these parameters for the lumen of human capillaries, arterioles and arteries using reaction-diffusion-advection models. These models considered O2•- and H2O2 production by endothelial cells and uptake by erythrocytes and endothelial cells, O2•- dismutation, O2•- and H2O2 diffusion and advection by the blood flow. Results show that in this environment O2•- and H2O2 have half-lives <60. ms and <40. ms, respectively, the former determined by the plasma SOD3 activity, the latter by clearance by endothelial cells and erythrocytes. H2O2 concentrations do not exceed the 10 nM scale. Maximal O2•- concentrations near vessel walls exceed H2O2's several-fold when the latter results solely from O2•- dismutation. Cytosolic dismutation of inflowing O2•- may thus significantly contribute to H2O2 delivery to cells. O2•- concentrations near vessel walls decay to 50% of maximum 12 µm downstream from O2•- production sites. H2O2 concentrations in capillaries decay to 50% of maximum 22 µm (6.0 µm) downstream from O2•- (H2O2) production sites. Near arterioles' (arteries') walls, they decay by 50% within 6.0 µm (4. µm) of H2O2 production sites. However, they reach maximal values 50 µm (24 µm) downstream from O2•- production sites and decrease by 50% over 650 µm (500 µm). Arterial/olar endothelial cells might thus signal over a mm downstream through O2•--derived H2O2, though this requires nM-sensitive H2O2 transduction mechanisms.

Impacts of ocean warming and acidification on the energy budget of three commercially important fish species.

A mechanistic model based on Dynamic Energy Budget (DEB) theory was developed to predict the combined effects of ocean warming, acidification and decreased food availability on growth and reproduction of three commercially important marine fish species: white seabream (Diplodus sargus), zebra seabream (Diplodus cervinus) and Senegalese sole (Solea senegalensis). Model simulations used a parameter set for each species, estimated by the Add-my-Pet method using data from laboratory experiments complemented with bibliographic sources. An acidification stress factor was added as a modifier of the somatic maintenance costs and estimated for each species to quantify the effect of a decrease in pH from 8.0 to 7.4 (white seabream) or 7.7 (zebra seabream and Senegalese sole). The model was used to project total length of individuals along their usual lifespan and number of eggs produced by an adult individual within one year, under different climate change scenarios for the end of the 21st century. For the Intergovernmental Panel on Climate Change SSP5-8.5, ocean warming led to higher growth rates during the first years of development, as well as an increase of 32-34% in egg production, for the three species. Ocean acidification contributed to reduced growth for white seabream and Senegalese sole and a small increase for zebra seabream, as well as a decrease in egg production of 48-52% and 14-33% for white seabream and Senegalese sole, respectively, and an increase of 4-5% for zebra seabream. The combined effect of ocean warming and acidification is strongly dependent on the decrease of food availability, which leads to significant reduction in growth and egg production. This is the first study to assess the combined effects of ocean warming and acidification using DEB models on fish, therefore, further research is needed for a better understanding of these climate change-related effects among different taxonomic groups and species.

Synergistic Effects of Climate Change and Marine Pollution: An Overlooked Interaction in Coastal and Estuarine Areas.

Coastal areas have been increasingly affected by human activities, marine pollution and climate change are among the most important pressures affecting these environments. Human-induced pressures occur in a cumulative way and generate additive, antagonistic or synergistic effects. Knowledge on synergistic effects is crucial to coastal zone management, since they may imply a change in human uses of these systems, as well as dedicated action plans in order to reduce hazards and environmental risks. In this work, we provide an overview of the available literature on synergistic effects between climate change and chemical pollution, and discuss current knowledge, methodological approaches, and research gaps and needs. Interactions between these two pressures may be climate change dominant (climate change leads to an increase in contaminant exposure or toxicity) or contaminant-dominant (chemical exposure leads to an increase in climate change susceptibility), but the mechanistic drivers of such processes are not well known. Results from a few meta-analyses studies and reviews showed that synergistic interactions tend to be more frequent compared to additive and antagonistic ones. However, most of the studies are individual-based and assess the cumulative effects of a few contaminants individually in laboratory settings together with few climate variables, particularly temperature and pH. Nevertheless, a wide diversity of contaminants have already been individually tested, spanning from metals, persistent organic pollutants and, more recently, emergent pollutants. Population and community based approaches are less frequent but have generated very interesting and more holistic perspectives. Methodological approaches are quite diverse, from laboratory studies to mesocosm and field studies, or based on statistical or modelling tools, each with their own potential and limitations. More holistic comparisons integrating several pressures and their combinations and a multitude of habitats, taxa, life-stages, among others, are needed, as well as insights from meta-analyses and systematic reviews.

Measuring the Impact of Bile Acids on the Membrane Order of Primary Hepatocytes and Isolated Mitochondria by Fluorescence Imaging and Spectroscopy.

Cholestasis is characterized by impaired secretion of bile flow that can result in the accumulation of highly abnormal levels of bile acids causing hepatocyte and biliary injury. As amphipathic molecules, bile acids can intercalate in lipid membranes, and pathophysiologic concentrations of bile acids have the potential to induce marked changes in the biophysical properties of biomembranes, including membrane ordering. These effects, particularly on the mitochondrial and plasma membranes, have been proposed to trigger toxicity of bile acids. This chapter details different fluorescence-based methods (fluorescence polarization, and spectroscopy/imaging of solvatochromic dyes) to evaluate the impact of different bile acids on membrane order. Protocols are described for the application of these methods to biomimetic vesicles, isolated mitochondria, and hepatocytes, following a bottom-up approach.

Alterações maternas e desfecho gravídico-puerperal na ocorrência de óbito materno / Maternal changes and puerperal pregnancy outcome in maternal death occurrence

Resumo Introdução A mortalidade materna representa um evento de grande magnitude no Brasil e no mundo, refletindo a falta de acesso aos serviços de saúde e as condições socioeconômicas desfavoráveis. Objetivo Relacionar as alterações maternas com o desfecho gravídico-puerperal no óbito materno. Métodos Estudo transversal e retrospectivo, conduzido com dados coletados de 53 prontuários de gestantes e puérperas que foram a óbito em um hospital estadual referência em gestação de alto risco em Goiás. Resultados A mortalidade ocorreu mais frequentemente em mulheres com idade entre 20 e 34 anos (76%), solteiras (55%), primigestas (38%), procedentes do interior do Estado (60%) e com parto na instituição do estudo (62%). As principais causas obstétricas de óbito foram as diretas (55%), com predomínio no período puerperal (83%). A razão da mortalidade materna correspondeu a 228,4 por 100 mil nascidos vivos. Houve uma associação significativa entre as complicações no parto e o local de ocorrência do parto (P=0,001). Conclusão O óbito materno ocorreu em solteiras, com idade reprodutiva, procedentes de outros municípios, por causas diretas e no puerpério. Ressalta-se a necessidade de melhorar o acesso aos serviços de saúde em obstetrícia, pois a maioria dos casos pode ser prevenida.

Abstract Introduction Maternal mortality represents an event of great magnitude in Brazil and worldwide. The occurrence of maternal death reflects the lack of access to health services and unfavorable socioeconomic conditions. Objective To correlate maternal changes and puerperal pregnancy outcome in maternal death. Methods Cross-sectional and retrospective study. We used data collected from 53 medical records of pregnant women and postpartum women who died at a Reference State Hospital in high risk gestation in Goiás. Results Mortality occurred in women aged 20 to 34 years (76%), single (55%), first pregnancy (38%), from the interior of the State (60%) and 62% had the childbirth at the institution of the study. The main obstetric causes were 55% direct and 24% indirect, being predominant in the puerperal period (83%). The maternal mortality ratio was 228.4. There was a significant association between complications at childbirth and the place of birth (P = 0.001). Conclusion The maternal death occurred in single women, of reproductive age, coming from other counties, for direct causes and in the puerperium. It is necessary to improve the access to health services in obstetrics, since most cases are preventable.

The universality and the future prospects of physiological energetics: Reply to comments on "Physics of metabolic organization".

In response to the comments on review "Physics of metabolic organization", we discuss the universality and the future prospects of physiological energetics. The topics range from the role of entropy in modeling living organisms to the apparent ubiquity of the von Bertalanffy curve, and the potential applications of the theory in yet unexplored domains. Tradeoffs in outreach to non-specialists are also briefly considered.

Physics of metabolic organization.

We review the most comprehensive metabolic theory of life existing to date. A special focus is given to the thermodynamic roots of this theory and to implications that the laws of physics-such as the conservation of mass and energy-have on all life. Both the theoretical foundations and biological applications are covered. Hitherto, the foundations were more accessible to physicists or mathematicians, and the applications to biologists, causing a dichotomy in what always should have been a single body of work. To bridge the gap between the two aspects of the same theory, we (i) adhere to the theoretical formalism, (ii) try to minimize the amount of information that a reader needs to process, but also (iii) invoke examples from biology to motivate the introduction of new concepts and to justify the assumptions made, and (iv) show how the careful formalism of the general theory enables modular, self-consistent extensions that capture important features of the species and the problem in question. Perhaps the most difficult among the introduced concepts, the utilization (or mobilization) energy flow, is given particular attention in the form of an original and considerably simplified derivation. Specific examples illustrate a range of possible applications-from energy budgets of individual organisms, to population dynamics, to ecotoxicology.

Immobilization of Ochrobactrum tritici As5 on PTFE thin films for arsenite biofiltration.

Ochrobactrum tritici SCII24T bacteria is an environmental strain with high capacity to resist to arsenic (As) toxicity, which makes it able to grow in the presence of As(III). The inactivation of the two functional arsenite efflux pumps, ArsB and ACR3_1, resulted in the mutant O. tritici As5 exhibiting a high accumulation of arsenite. This work describes a method for the immobilization of the mutant cells O. tritici As5, on a commercial polymeric net after sputtered modified by the deposition of poly(tetrafluoroethylene) (PTFE) thin films, and demonstrates the capacity of immobilized cells to accumulate arsenic from solutions. Six different set of deposition parameters for PTFE thin films were developed and tested in vitro regarding their ability to immobilize the bacterial cells. The surface that exhibited a mild zeta potential value, hydrophobic characteristics, the lowest surface free energy but with a high polar component and the appropriate ratio of chemical reactive groups allowed cells to proliferate and to grow as a biofilm. These immobilized cells maintained their ability to accumulate the surrounding arsenite, making it a great arsenic biofilter to be used in bioremediation processes.

Adaptive Evolution Favoring KLK4 Downregulation in East Asians.

The human kallikrein (KLK) cluster, located at chromosome 19q13.3-13.4, encodes 15 serine proteases, including neighboring genes (KLK3, KLK2, KLK4, and KLK5) with key roles in the cascades of semen liquefaction, tooth enamel maturation, and skin desquamation. KLK2 and KLK3 were previously identified as targets of adaptive evolution in primates through different mechanisms linked to reproductive biology and, in humans, genome-wide scans of positive selection captured, a yet unexplored, evidence for KLK neutrality departure in East Asians. We perform a detailed evaluation of KLK3-KLK5 variability in the 1000 Genomes samples from East Asia, Europe, and Africa, which was sustained by our own sequencing. In East Asians, we singled out a 70-kb region surrounding KLK4 that combined unusual low levels of diversity, high frequency variants with significant levels of population differentiation (FST > 0.5) and fairly homogenous haplotypes given the large local recombination rates. Among these variants, rs1654556_G, rs198968_T, and rs17800874_A stand out for their location on putative regulatory regions and predicted functional effects, namely the introduction of several microRNA binding sites and a repressor motif. Our functional assays carried out in different cellular models showed that rs198968_T and rs17800874_A operate synergistically to reduce KLK4 expression and could be further assisted by rs1654556_G. Considering the previous findings that KLK4 inactivation causes enamel malformations in humans and mice, and that this gene is coexpressed in epidermal layers along with several substrates involved in either cell adhesion or keratinocyte differentiation, we propose KLK4 as another target of selection in East Asians correlated to tooth and epidermal morphological traits.

Deoxycholic acid modulates cell death signaling through changes in mitochondrial membrane properties.

Cytotoxic bile acids, such as deoxycholic acid (DCA), are responsible for hepatocyte cell death during intrahepatic cholestasis. The mechanisms responsible for this effect are unclear, and recent studies conflict, pointing to either a modulation of plasma membrane structure or mitochondrial-mediated toxicity through perturbation of mitochondrial outer membrane (MOM) properties. We conducted a comprehensive comparative study of the impact of cytotoxic and cytoprotective bile acids on the membrane structure of different cellular compartments. We show that DCA increases the plasma membrane fluidity of hepatocytes to a minor extent, and that this effect is not correlated with the incidence of apoptosis. Additionally, plasma membrane fluidity recovers to normal values over time suggesting the presence of cellular compensatory mechanisms for this perturbation. Colocalization experiments in living cells confirmed the presence of bile acids within mitochondrial membranes. Experiments with active isolated mitochondria revealed that physiologically active concentrations of DCA change MOM order in a concentration- and time-dependent manner, and that these changes preceded the mitochondrial permeability transition. Importantly, these effects are not observed on liposomes mimicking MOM lipid composition, suggesting that DCA apoptotic activity depends on features of mitochondrial membranes that are absent in protein-free mimetic liposomes, such as the double-membrane structure, lipid asymmetry, or mitochondrial protein environment. In contrast, the mechanism of action of cytoprotective bile acids is likely not associated with changes in cellular membrane structure.

Hyper Accumulation of Arsenic in Mutants of Ochrobactrum tritici Silenced for Arsenite Efflux Pumps.

Ochrobactrum tritici SCII24T is a highly As-resistant bacterium, with two previously described arsenic resistance operons, ars1 and ars2. Among a large number of genes, these operons contain the arsB and Acr3 genes that encode the arsenite efflux pumps responsible for arsenic resistance. Exploring the genome of O. tritici SCII24T, an additional putative operon (ars3) was identified and revealed the presence of the Acr3_2 gene that encodes for an arsenite efflux protein but which came to prove to not be required for full As resistance. The genes encoding for arsenite efflux pumps, identified in this strain, were inactivated to develop microbial accumulators of arsenic as new tools for bioremediation. Six different mutants were produced, studied and three were more useful as biotools. O. tritici wild type and the Acr3-mutants showed the highest resistance to As(III), being able to grow up to 50 mM of arsenite. On the other hand, arsB-mutants were not able to grow at concentrations higher than 1 mM As(III), and were the most As(III) sensitive mutants. In the presence of 1 mM As(III), the strain with arsB and Acr3_1 mutated showed the highest intracellular arsenic concentration (up to 17 ng(As)/mg protein), while in assays with 5 mM As(III), the single arsB-mutant was able to accumulate the highest concentration of arsenic (up to 10 ng(As)/mg protein). Therefore, arsB is the main gene responsible for arsenite resistance in O. tritici. However, both genes arsB and Acr3_1 play a crucial role in the resistance mechanism, depending on the arsenite concentration in the medium. In conclusion, at moderate arsenite concentrations, the double arsB- and Acr3_1-mutant exhibited a great ability to accumulate arsenite and can be seen as a promising bioremediation tool for environmental arsenic detoxification.

O reduzido envolvimento social: implicações para o ajustamento psicossocial de crianças em contexto pré-escolar / Low social engagement: implications for children psychosocial adjustment in the preschool context

O reduzido envolvimento social, aspeto central na definição da solidão social, foi analisado numa amostra de 337 crianças portuguesas (171 rapazes), com idades compreendidas entre os três e os cinco anos. Com base em metodologias de observação, realizadas em contexto de Jardim de infância, verificou-se que níveis reduzidos de envolvimento social estão negativamente associados a baixos níveis de competência social, de resiliência e de um elevado ego-controle. A aceitação pelos pares, o impacto e a preferência social, analisados com base nas medidas sociométricas, encontram-se, também, negativamente associados com os níveis de baixo envolvimento social. Os resultados refletem as dificuldades de ajustamento psicossocial destas crianças e enfatizam o seu potencial risco para o desenvolvimento saudável.(AU)

Low social engagement, a central feature of the definition of solitude, was examined in a sample of 337 Portuguese children (171 boys), ages ranging between 3 and 5 years. Based on observation measures, collected in school settings, Low Social Engagement was negatively associated with a broad range of adaptive outcomes, including social competence, ego-resilience as well as higher levels of ego-undercontrol. Negative associations were also found with sociometric measures of peer acceptance, social impact and preference. The results reflect these children's difficulties in the social domain and stress the potential risk factor of social solitude for their healthy development.(AU)

O reduzido envolvimento social: implicações para o ajustamento psicossocial de crianças em contexto pré-escolar / Low social engagement: implications for children psychosocial adjustment in the preschool context

O reduzido envolvimento social, aspeto central na definição da solidão social, foi analisado numa amostra de 337 crianças portuguesas (171 rapazes), com idades compreendidas entre os três e os cinco anos. Com base em metodologias de observação, realizadas em contexto de Jardim de infância, verificou-se que níveis reduzidos de envolvimento social estão negativamente associados a baixos níveis de competência social, de resiliência e de um elevado ego-controle. A aceitação pelos pares, o impacto e a preferência social, analisados com base nas medidas sociométricas, encontram-se, também, negativamente associados com os níveis de baixo envolvimento social. Os resultados refletem as dificuldades de ajustamento psicossocial destas crianças e enfatizam o seu potencial risco para o desenvolvimento saudável.

Low social engagement, a central feature of the definition of solitude, was examined in a sample of 337 Portuguese children (171 boys), ages ranging between 3 and 5 years. Based on observation measures, collected in school settings, Low Social Engagement was negatively associated with a broad range of adaptive outcomes, including social competence, ego-resilience as well as higher levels of ego-undercontrol. Negative associations were also found with sociometric measures of peer acceptance, social impact and preference. The results reflect these children's difficulties in the social domain and stress the potential risk factor of social solitude for their healthy development.

High-volume postdilution hemodiafiltration is a feasible option in routine clinical practice.

Hemodiafiltration (HDF) with 20-22 L of substitution fluid is increasingly recognized as associated with significant benefits regarding patient outcome. However, some doubt exists as to whether these high volumes can be achieved in routine clinical practice. A total of 4176 sessions with 366 patients on postdilution HDF were analyzed in this 1-month observational cohort study with prospective data collection. All dialysis machines were equipped with AutoSub plus signal analysis software that automatically and continuously adapts the substitution fluid flow according to the blood flow, blood viscosity, and dialyzer characteristics. Percentages of sessions with different types of vascular access were compared regarding achievement of ≥21 L substitution fluid. Logistic regression analysis was conducted to study the independent relationship of selected variables with achievement of ≥21 L substitution volume. Patient- and dialysis-related variables that showed an association with the convection volume were entered in a multivariable model that included hematocrit up front. Respectively, 87%, 84%, and 33% of routine sessions conducted with fistulas, grafts, and catheters qualified as high-volume HDF. Serum albumin levels ≥4.2 g/dL were positively associated with the achievement of at least 21 L substitution volume. Positive associations were also observed for blood flows in the ranges 350-399 and ≥400 mL/min compared with the reference range (300-350 mL/min), for longer treatment time, for fistula versus catheter, for higher filtration fraction, and for dialysis conducted at the end of the week versus Monday. It can be concluded that implementation and sustainability of high-volume HDF is possible in routine clinical practice for almost all patients treated with fistulas and grafts.

Cytotoxic bile acids, but not cytoprotective species, inhibit the ordering effect of cholesterol in model membranes at physiologically active concentrations.

Submillimolar concentrations of cytotoxic bile acids (BAs) induce cell death via apoptosis. On the other hand, several cytoprotective BAs were shown to prevent apoptosis in the same concentration range. Still, the mechanisms by which BAs trigger these opposite signaling effects remain unclear. This study was aimed to determine if cytotoxic and cytoprotective BAs, at physiologically active concentrations, are able to modulate the biophysical properties of lipid membranes, potentially translating into changes in the apoptotic threshold of cells. Binding of BAs to membranes was assessed through the variation of fluorescence parameters of suitable derivatized BAs. These derivatives partitioned with higher affinity to liquid disordered than to the cholesterol-enriched liquid ordered domains. Unlabeled BAs were also shown to have a superficial location upon interaction with the lipid membrane. Additionally, the interaction of cytotoxic BAs with membranes resulted in membrane expansion, as concluded from FRET data. Moreover, it was shown that cytotoxic BAs were able to significantly disrupt the ordering of the membrane by cholesterol at physiologically active concentrations of the BA, an effect not associated with cholesterol removal. On the other hand, cytoprotective bile acids had no effect on membrane properties. It was concluded that, given the observed effects on membrane rigidity, the apoptotic activity of cytotoxic BAs could be potentially associated with changes in plasma membrane organization (e.g. modulation of lipid domains) or with an increase in mitochondrial membrane affinity for apoptotic proteins.

Aerobic uranium immobilization by Rhodanobacter A2-61 through formation of intracellular uranium-phosphate complexes.

Severe environmental problems arise from old uranium mines, which continue to discharge uranium (U) via acid mine drainage water, resulting in soil, subsoil and groundwater contamination. Bioremediation of U contaminated environments has been attempted, but most of the conceptual models propose U removal by cell suspensions of anaerobic bacteria. In this study, strain Rhodanobacter A2-61, isolated from Urgeiriça Mine, Portugal, was shown to resist up to 2 mM of U(vi). The conditions used (low nutrient content and pH 5) potentiated the interaction of the toxic uranyl ion with the tested strain. The strain was able to remove approximately 120 µM of U(vi) when grown aerobically in the presence of 500 µM U. Under these conditions, this strain was also able to lower the phosphate concentration in the medium and increased its capacity to take up inorganic phosphate, accumulating up to 0.52 µmol phosphate per optical density unit of the medium at 600 nm, after 24 hours, corresponding approximately to the late log phase of the bacterial culture. Microscopically dense intracellular structures with nanometer size were visible. The extent of U inside the cells was quantified by LS counting. EDS analysis of heated cells showed the presence of complexes composed of phosphate and uranium, suggesting the simultaneous precipitation of U and phosphate within the cells. XRD analysis of the cells containing the U-phosphate complexes suggested the presence of a meta-autunite-like mineral structure. SEM identified, in pyrolyzed cells, crystalline nanoparticles with shape in the tetragonal system characteristic of the meta-autunite-like mineral structures. U removal has been reported previously but mainly by cell suspensions and through release of phosphate. The innovative Rhodanobacter A2-61 can actively grow aerobically, in the presence of U, and can efficiently remove U(vi) from the environment, accumulating it in a structural form consistent with that of the mineral meta-autunite inside the cell, corresponding to effective metal immobilization. This work supports previous findings that U bioremediation could be achieved via the biomineralization of U(vi) in phosphate minerals.

Efeitos de um treino aeróbio em doentes em programa de hemodiálise / Effects of an aerobic training on patients undergoing a hemodialysis program

A Insuficiência Renal Crónica e consequente tratamento hemodialítico tem um potencial significativo na alteração do estilo de vida destes doentes, conduzindo-os a uma dependência de cuidados de saúde e reabilitação e, eventualmente, à perda de papéis sociais, tornando a promoção de um Envelhecimento Ativo fulcral nesta população. Em virtude das alterações mencionadas torna-se imprescindível a implementação de estratégias e programas de treino de exercício físico que visem minimizar grande parte das complicações recorrentes desta síndrome e que contribuam consequentemente para uma melhoria da qualidade de vida. Esta investigação pretende avaliar os efeitos de um treino aeróbio em doentes hemodialisados com insuficiência renal crónica. A população deste estudo foi constituída pelos 100 doentes com Insuficiência Renal Crónica em programa regular de hemodiálise na clínica de hemodiálise Tecnologias e Serviços Médicos, SA, de Mirandela, sendo oferecida a todos a mesma possibilidade de participar no programa de treino. Após aplicados os critérios de exclusão resultou um grupo com condições para participar no treino, do qual foram seleccionados aleatoriamente por ordem alfabética 16 doentes, para integrar o Grupo de Controlo (GC). Posteriormente e tendo em consideração as escolhas dos próprios doentes e as condições logísticas da clinica, resultou uma amostra de 43 doentes para integrar no Grupo de Treino (GT). O programa de treino aeróbio foi implementado no início do mês de Maio de 2012 durante 8 semanas consecutivas, com uma frequência de 3 sessões por semana durante o tratamento de hemodiálise. Antes e após a intervenção foram executadas as respetivas avaliações físicas e funcionais, e questionário SF-36v2 de autopreenchimento. O grupo de treino é caracterizado por uma média de idades de 71,93±11,76 anos e encontram-se a efectuar hemodiálise a 4,29±3,22 anos, evidencia, após a intervenção alterações significativas nos níveis de hemoglobina de 11,02±0,88g/dL para 11,3±0,698g/dL e no hematócrito de 32,55±2,62% para 33,59 1.9%. Relativamente aos testes funcionais importa referenciar o aumento do número de repetições de 13,24±4,96 para 18.08±6,23 no teste Sentar/Levantar e a diminuição do tempo necessário para a execução do teste Levantar e Andar de 15,03±10.90s para 9,67±5,74s. Quanto à Qualidade de Vida, verificou-se alteração significativa referente à componente saúde mental, de 49,93±9,953 para 53,22±7,545. O treino implementado teve, de forma geral, uma repercussão benéfica na capacidade aeróbia/funcional destes doentes, bem como na percepção da sua Qualidade de Vida, especificamente na componente referente a saúde mental. Novas investigações são necessárias para determinar os efeitos deste tipo de treino sobre a tensão arterial, glicose e dose de EPO administrada.

The Chronic Kidney Disease and the hemodialysis treatment has significant potential in changing negatively the lifestyle of these patients, leading them to a reliance on health care and rehabilitation and, eventually, loss of social roles. Therefore, the promotion of Active Ageing in this population is critical. Because of the changes mentioned, it's essential the implementation of strategies and programs for exercise training, designed to minimize many of the complications of this syndrome and consequently contribute to an improved quality of life. This research aims to evaluate the effects of aerobic training in hemodialysis patients with chronic renal disease. The study population was composed of 100 patients with Chronic Kidney Disease on regular hemodialysis program in the Clínica Tecnologias e Serviços Médicos, SA, de Mirandela, being offered to everyone the same opportunity to participate in the program training. After applying the exclusion criteria the resulte was a group with conditions to participate in the training, which were randomly selected alphabetically 16 patients, to integrate the Control Group (GC). Later, taking into account the choices of the patients and the logistics of clinical conditions, the result was a sample of 43 patients to integrate the Training Group (GT). The aerobic exercise program was implemented in early May of 2012 for 8 consecutive weeks, with a frequency of 3 sessions per week during the dialysis treatment. Before and after the intervention were executed the respective functional and physical assessments and the SF36-v2 questionnaire. The training group is characterized by a mean age of 71.93±11.76 years and in hemodialysis 4.29±3.22 years, after the intervention had significant changes in hemoglobin levels of 11.02±0.88g/dL to 11.3±0.698g/dL and hematocrit of 32.55±2.62% to 33.59±1.9%. In the sit to stand test were observed changes in the number of repetitions of 13.24±4.96 to 18.08±6.23 and in the up and go the time to complete the test went from 15.03±10.90s to 9.67±5.74s. In the quality of life, the change was from 49.93±9.953 to 53.22±7.545 in the component related to mental health. The intradialytic aerobic training implemented was, in general, a beneficial effect on aerobic capacity/functional of these patients, as well on the perception of their quality of life, specifically in the component related to mental health. Further investigations are needed to determine the effects of this type of training on blood pressure, glucose and EPO dose administered.