Summary
Background
Worldwide, dengue is the most prevalent human arbovirus disease. Dengue infection may cause a range of clinical manifestations from self‐limiting febrile illness through to a ...life‐threatening syndrome accompanied by both bleeding and shock. Thrombocytopenia is frequently observed in mild and severe disease; however, the mechanisms involved in DENV‐induced platelet activation and thrombocytopenia are incompletely understood.
Patients and methods
Freshly isolated platelets from patients with dengue were evaluated for markers of activation, mitochondrial alteration and activation of cell death pathways. In parallel, we examined direct DENV‐induced activation and apoptosis of platelets obtained from healthy subjects.
Results
We found that platelets from DENV‐infected patients exhibited increased activation by comparison to control subjects. Moreover, platelets from DENV‐infected patients exhibited classic signs of the intrinsic pathway of apoptosis that include increased surface phosphatidylserine exposure, mitochondrial depolarization and activation of caspase‐9 and ‐3. Indeed, thrombocytopenia was shown to strongly associate with enhanced platelet activation and cell death in DENV‐infected patients. Platelet activation, mitochondrial dysfunction and caspase‐dependent phosphatidylserine exposure on platelets were also observed when platelets from healthy subjects were directly exposed to DENV in vitro. DENV‐induced platelet activation was shown to occur through mechanisms largely dependent on DC‐SIGN.
Conclusions
Together our results demonstrate that platelets from patients with dengue present signs of activation, mitochondrial dysfunction and activation of the apoptosis caspase cascade, which may contribute to the development of thrombocytopenia in patients with dengue. Our results also suggest the involvement of DC‐SIGN as a critical receptor in DENV‐dependent platelet activation.
Resumo Fundamentos: Os mecanismos subjacentes pelos quais a doença cardíaca reumática (DCR) levam à disfunção valvar grave não são totalmente compreendidos. Objetivo: O presente estudo avaliou as ...alterações histopatológicas nas valvas mitrais (VM) buscando uma associação entre o padrão de disfunção valvar predominante e os achados histopatológicos. Métodos: Em 40 pacientes submetidos à troca da VM devido a DCR e em 20 controles submetidos a transplante cardíaco, foram analisados os aspectos histológicos da VM excisada. Dados clínicos e ecocardiográficos também foram coletados. As análises histológicas foram realizadas usando coloração com hematoxilina-eosina. Determinou-se inflamação, fibrose, neoangiogênese, calcificação e metaplasia adiposa. Valores de p<0,05 foram considerados estatisticamente significativos. Resultados: A idade média dos pacientes com DCR foi de 53±13 anos, sendo 36 (90%) do sexo feminino, enquanto a idade média dos controles foi de 50±12 anos, semelhante aos casos, sendo a maioria do sexo masculino (70%). O endocárdio valvar reumático apresentou espessura maior que os controles (1,3±0,5 mm versus 0,90±0,4 mm, p=0,003, respectivamente), e infiltrado inflamatório mais intenso no endocárdio (78% versus 36%; p=0,004), com predominância de células mononucleares. Ocorreu fibrose moderada a acentuada mais frequentemente em válvulas reumáticas do que em válvulas controle (100% vs. 29%; p<0,001). Ocorreu calcificação em 35% das valvas reumáticas, principalmente entre as valvas estenóticas, associada à área valvar mitral (p=0,003). Conclusões: Apesar do intenso grau de fibrose, o processo inflamatório permanece ativo na valva mitral reumática, mesmo em doença tardia com disfunção valvar. A calcificação predominou em valvas estenóticas e em pacientes com disfunção ventricular direita.
Com base na Lei do Serviço Militar (LSM), o Exército Brasileiro denomina de “atirador” o jovem matriculado no Tiro de Guerra (TG). Extensionistas do Programa “Amizade Compatível - uma doação para a ...vida”realizaram ações de conscientização com os atiradores do TG de Uberaba em parceria com o Projeto Maçom Sangue Bom.
Analisar o conhecimento de atiradores do tiro de guerra sobre os temas doação de sangue (DS) e medula óssea (MO).
O TG de Uberaba possui o contingente de 200 atiradores dos quais 195 (96%) participaram da ação de conscientização. Foram realizados quatro encontros com os atiradores pela plataforma Google Meet. Durante estes momentos houve sensibilização, esclarecimentos e conscientização da importância da DS, da fidelização do doador e do cadastro no Registro Nacional de Doadores de Medula Óssea (REDOME). Ao final da ação extensionista os atiradores tiveram acesso a um formulário com questões sobre: idade, escolaridade, tipo sanguíneo, cadastro/DS e MO, se haviam parentes que já precisaram de transfusão sanguínea, vontade de doar sangue, se já haviam recebido informações sobre os temas abordados, satisfação com a ação, situações de inaptidão temporária e redes sociais utilizadas.
Dos 195 participantes somente um não respondeu ao formulário. A idade variou entre 18 e 21 anos. 88,4% dos atiradores possuíam ensino médio completo, 5,7% fundamental completo, 4,6% assinalaram “outros” e 1,5% não responderam. Sobre o grupo sanguíneo ABO Rh, 65,4% não sabiam seu tipo, porém 99,9% achavam importante ter a informação. 91,8% nunca doaram sangue e 89,2% tem vontade de doar. Em relação a possuírem parentes que já necessitaram de transfusão sanguínea, 25,2% referiam que parentes já precisaram dessa terapêutica e 74,8% não precisaram. Dos que já realizaram a doação (8,2%), 68,8% doaram somente uma vez e 50% possuíam parentes que necessitaram de transfusão de sangue. Sobre o cadastro para doação de MO 96,3% não são cadastrados. 66% relataram ter recebido alguma informação sobre DS e MO antes da palestra, enquanto os demais nunca haviam recebido. Porém, 64% acreditavam que não tinham conhecimento suficiente sobre estes temas. 99,4% relataram que a palestra foi capaz de sanar as dúvidas e 96,9% relataram que ficaram muito satisfeitos ou satisfeitos com a atividade realizada. 95% dos atiradores utilizam alguma rede social entre Instagram, Facebook, Twitter, Tiktok e destes 84% utilizam mais de uma. Houve um acerto de 97,4% nas perguntas sobre inaptidão temporária para DS realizadas após a palestra.
Atendendo as diretrizes do Ministério da saúde que buscam estratégias educativas para promoção da doação voluntária de sangue e formação de multiplicadores, os TGs constituem um importante ambiente para a realização dessas atividades. Muitas campanhas para DS são realizadas envolvendo atiradores dos TGs, entretanto as ações extensionistas direcionadas a esclarecimento e sensibilização para DS e MO e, também, para fidelização do doador ainda são importantes pois dois terços do contingente acreditava não possuir conhecimento suficiente e quase cem porcento deles relataram que as ações de extensão foram capaz de sanar suas dúvidas.
A realização de ações de extensão é importante para a conscientização de jovens adultos que apresentaram expressiva satisfação com a atividade e absorção de conhecimento sobre a DS e de MO e estes podem ser multiplicadores destes temas na comunidade.
The flux performance of different hydrophobic microporous flat sheet commercial membranes made of poly tetrafluoroethylene (PTFE) and poly propylene (PP) was tested for Red Sea water desalination ...using the direct contact membrane distillation (DCMD) process, under bench scale (high ΔT) and large scale module (low ΔT) operating conditions. Membranes were characterized for their surface morphology, water contact angle, thickness, porosity, pore size and pore size distribution. The DCMD process performance was optimized using a locally designed and fabricated module aiming to maximize the flux at different levels of operating parameters, mainly feed water and coolant inlet temperatures at different temperature differences across the membrane (ΔT). Water vapor flux of 88.8kg/m2h was obtained using a PTFE membrane at high ΔT (60°C). In addition, the flux performance was compared to the first generation of a new locally synthesized and fabricated membrane made of a different class of polymer under the same conditions. A total salt rejection of 99.99% and boron rejection of 99.41% were achieved under extreme operating conditions. On the other hand, a detailed water characterization revealed that low molecular weight non-ionic molecules (ppb level) were transported with the water vapor molecules through the membrane structure. The membrane which provided the highest flux was then tested under large scale module operating conditions. The average flux of the latter study (low ΔT) was found to be eight times lower than that of the bench scale (high ΔT) operating conditions.
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•Performance evaluation of the DCMD process was investigated.•Different membranes were tested under different operating conditions.•Experiments were carried out under bench and large scale module operating conditions.•MD membranes and permeates were characterized using advanced equipment.
Land degradation causes great changes in the soil biological properties. The process of degradation may decrease soil microbial biomass and consequently decrease soil microbial activity. The study ...was conducted out during 2009 and 2010 at the four sites of land under native vegetation （NV）, moderately degraded land （LDL）, highly degraded land （HDL） and land under restoration for four years （RL） to evaluate changes in soil microbial biomass and activity in lands with different degradation levels in comparison with both land under native vegetation and land under restoration in Northeast Brazil. Soil samples were collected at 0-10 cm depth. Soil organic carbon （SOC）, soil microbial biomass C （MBC） and N （MBN）, soil respiration （SR）, and hydrolysis of fluorescein diacetate （FDA） and dehydrogenase （DHA） activities were analyzed. After two years of evaluation, soil MBC, MBN, FDA and DHA had higher values in the NV, followed by the RL. The decreases of soil microbial biomass and enzyme activities in the degraded lands were approximately 8 10 times as large as those found in the NV. However, after land restoration, the MBC and MBN increased approximately 5-fold and 2-fold, respectively, compared with the HDL. The results showed that land degradation produced a strong decrease in soil microbial biomass. However, land restoration may promote short- and long-term increases in soil microbial biomass.
The flow through the air turbine of an oscillating water column (OWC) wave energy converter is reciprocating and is random and highly variable. It is not surprising that the time-averaged efficiency ...of the air turbine is substantially lower than that of a conventional turbine working in nearly steady conditions. A new type of radial-flow self-rectifying turbine (named here biradial turbine) is described in the paper. The two inlet/outlet openings of the rotor are axially offset from each other and face radially the surrounding space. The turbine is symmetrical with respect to a plane perpendicular to its axis of rotation. The rotor blades are surrounded by a pair of radial-flow guide-vane rows. Each guide vane row is connected to the rotor by an axisymmetric duct whose walls are flat discs. A two-dimensional flow method is used first as a preliminary design tool for the turbine geometry. More detailed numerical results are then obtained with the aid of a commercial three-dimensional real-fluid CFD code, which allows a more refined geometry optimization to be carried out, and yields results for flow details through the turbine and for the turbine overall performance under several operating conditions.
► A novel radial-flow self-rectifying air turbine for OWC wave energy converters. ► The new turbine is axially very compact and appropriate for flywheel mounting. ► Two configurations are considered: fixed or axially moving guide vanes. ► CFD modelling of turbine flow gives 83% as peak aerodynamic efficiency.
Yellow fever virus (YFV), a member of the family Flaviviridae, genus Flavivirus is endemic to tropical areas of Africa and South America and is among the arboviruses that pose a threat to public ...health. Recent outbreaks in Brazil, Bolivia, and Paraguay and the observation that vectors capable of transmitting YFV are presenting in urban areas underscore the urgency of improving surveillance and diagnostic methods. Two novel methods (RT-hemi-nested-PCR and SYBR® Green qRT-PCR) for efficient detection of YFV strains circulating in South America have been developed. The methods were validated using samples obtained from golden hamsters infected experimentally with wild-type YFV strains as well as human serum and tissue samples with acute disease.
The paper presents results from model testing of a self-rectifying radial-flow air turbine, that is being developed as an alternative to the axial-flow self-rectifying turbines for applications in ...wave energy conversion. In the new machine, named biradial turbine, the flow into, and out of, the rotor is radial. The rotor is surrounded by a pair of radial-flow guide-vane rows. The downstream guide vanes are prevented from obstructing the flow coming out of the rotor by axially displacing the whole guide vane set. The turbine model, with a 0.488 m diameter rotor, was tested in unidirectional flow. Experimental results are shown, in dimensionless form, for efficiency, power and pressure head versus flow rate. They are compared with predictions from CFD computations. The results from model testing were used to estimate the time-averaged efficiency of the turbine subject to the irregular bidirectional air flow induced by random waves.
Wildfires have become a recurrent threat for many Mediterranean forest ecosystems. The characteristics of the Mediterranean climate, with its warm and dry summers and mild and wet winters, make this ...a region prone to wildfire occurrence as well as to post-fire soil erosion. This threat is expected to be aggravated in the future due to climate change and land management practices and planning.
The wide recognition of wildfires as a driver for runoff and erosion in burnt forest areas has created a strong demand for model-based tools for predicting the post-fire hydrological and erosion response and, in particular, for predicting the effectiveness of post-fire management operations to mitigate these responses.
In this study, the effectiveness of two post-fire treatments (hydromulch and natural pine needle mulch) in reducing post-fire runoff and soil erosion was evaluated against control conditions (i.e. untreated conditions), at different spatial scales.
The main objective of this study was to use field data to evaluate the ability of different erosion models: (i) empirical (RUSLE), (ii) semi-empirical (MMF), and (iii) physically-based (PESERA), to predict the hydrological and erosive response as well as the effectiveness of different mulching techniques in fire-affected areas.
The results of this study showed that all three models were reasonably able to reproduce the hydrological and erosive processes occurring in burned forest areas. In addition, it was demonstrated that the models can be calibrated at a small spatial scale (0.5 m2) but provide accurate results at greater spatial scales (10 m2).
From this work, the RUSLE model seems to be ideal for fast and simple applications (i.e. prioritization of areas-at-risk) mainly due to its simplicity and reduced data requirements. On the other hand, the more complex MMF and PESERA models would be valuable as a base of a possible tool for assessing the risk of water contamination in fire-affected water bodies and for testing different land management scenarios.
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•RUSLE, MMF and PESERA, were able to predict the erosive response in burned areas and their mitigation.•These models can be calibrated at a small spatial scale and provide accurate results at greater spatial scales.•RUSLE model ideal for fast and simple risk assessment.•MMF or PESERA models could be the base of a post-fire management decision tool.
Although the early coral reef-bleaching warning system (NOAA/USA) is established, there is no feasible treatment that can minimize temperature bleaching and/or disease impacts on corals in the field. ...Here, we present the first attempts to extrapolate the widespread and well-established use of bacterial consortia to protect or improve health in other organisms (e.g., humans and plants) to corals. Manipulation of the coral-associated microbiome was facilitated through addition of a consortium of native (isolated from Pocillopora damicornis and surrounding seawater) putatively beneficial microorganisms for corals (pBMCs), including five Pseudoalteromonas sp., a Halomonas taeanensis and a Cobetia marina-related species strains. The results from a controlled aquarium experiment in two temperature regimes (26 °C and 30 °C) and four treatments (pBMC; pBMC with pathogen challenge - Vibrio coralliilyticus, VC; pathogen challenge, VC; and control) revealed the ability of the pBMC consortium to partially mitigate coral bleaching. Significantly reduced coral-bleaching metrics were observed in pBMC-inoculated corals, in contrast to controls without pBMC addition, especially challenged corals, which displayed strong bleaching signs as indicated by significantly lower photopigment contents and F
/F
ratios. The structure of the coral microbiome community also differed between treatments and specific bioindicators were correlated with corals inoculated with pBMC (e.g., Cobetia sp.) or VC (e.g., Ruegeria sp.). Our results indicate that the microbiome in corals can be manipulated to lessen the effect of bleaching, thus helping to alleviate pathogen and temperature stresses, with the addition of BMCs representing a promising novel approach for minimizing coral mortality in the face of increasing environmental impacts.
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