Abstract The methods of modelling and simulation of casting processes are carried out by means of software. This allows a reduction of time and costs in technological tests. As fundamental part of any casting mould is the feeding system, a component of the design on which the correct filling and solidification of the part depends. The aim of this work was to evaluate the feeding system of a permanent metal mould by gravity casting to obtain an aluminum alloy piston for an internal combustion engine, using CAD/CAE software for its modelling and simulation by finite elements. A modification was evaluated, simulated and proposed to provide a viable and economical solution, obtaining a satisfactory filling and solidification cycle that minimizes the current rejects of the original mould. The simulation of the proposal is in correspondence with the experiments carried out physically.

Resumen Los métodos de modelado y simulación de procesos de fundición se realizan a través de softwares. Esto permite una reducción de tiempo y costos en pruebas tecnológicas. Como parte fundamental de cualquier molde de fundición está el sistema de alimentación, componente del diseño del cual depende el correcto llenado y solidificación de la pieza. El objetivo de este trabajo fue evaluar el sistema de alimentación de un molde permanente metálico por fundición a gravedad para la obtención de un pistón de aleación de aluminio de motor de combustión interna, usando los softwares CAD/CAE para su modelación y simulación por elementos finitos. Se evaluó, simuló y planteó una modificación para dar una solución viable y económica, obteniendo un satisfactorio ciclo de llenado y solidificación que permite reducir al mínimo los rechazos actuales del molde original. La simulación de la propuesta está en correspondencia con los experimentos realizados físicamente.

ABSTRACT Background: Despite the abundance of information concerning ocrelizumab in phase III clinical trials, there is scarce evidence regarding real-world patient profiles. Objective: The aim of this study was to investigate patient profiles, effectiveness and persistence with treatment among patients who used ocrelizumab for treatment of multiple sclerosis in Latin America. Methods: This was a retrospective multicenter study in Argentina, Chile and Mexico. Medical record databases on patients who received ocrelizumab were analyzed. Demographic and clinical variables were described, along with effectiveness outcomes, which included the proportions of patients free from clinical relapses, from disability progression and from new or enlarging T2 or T1 gadolinium-enhancing lesions, on annual magnetic resonance imaging. Results: A total of 81 patients were included. The most frequent phenotype was relapsing-remitting MS, in 64.2% of the patients. The mean age at study entry was 41.3 ± 12.0 years and 51.8% were women. A total of 38% had had relapse activity during the 12 months before starting on ocrelizumab, with a mean relapse rate of 1.3 ± 0.6 during that period. 75% were free from clinical relapses and 91% were free from gadolinium-enhancing lesions in the relapsing-remitting course. Ocrelizumab discontinuation during the first 12 months was observed in three patients (3.7%). The mean persistence observed during the first-year follow-up was 338 ± 24 days. Conclusions: Our study is in line with previous randomized clinical trials and recent real-world studies describing patient profiles, effectiveness and persistence regarding ocrelizumab treatment in multiple sclerosis patients in Latin America.

RESUMEN Introducción: A pesar de la abundante información sobre ocrelizumab proveniente de los ensayos clínicos de fase III, todavía se tiene poca evidencia sobre la efectividad y el perfil de pacientes provenientes de la vida real. Objetivo: Evaluar el perfil clínico y demográfico, la efectividad y la persistencia al tratamiento en pacientes que usaron el ocrelizumab para el tratamiento de esclerosis múltiple (EM) en Latinoamérica. Métodos: Estudio retrospectivo multicéntrico en Argentina, Chile y México. Se analizaron los datos de los pacientes que recibieron ocrelizumab. Se describieron las variables demográficas y clínicas, así como los resultados de efectividad que incluyeron la proporción de pacientes libres de recaídas clínicas, libres de progresión de la discapacidad, libres de nuevas lesiones en la secuencia T2 o T1 con gadolinio durante el seguimiento. Resultados: Se incluyeron 81 pacientes. El fenotipo más frecuente fue EM remitente recurrente (EMRR) en el 64,2% de los pacientes. La edad media fue de 41.3±12 años, y el 51,8% eran mujeres. Un total de 38% tuvo recaídas durante los 12 meses previos al inicio de ocrelizumab, con una tasa anualizada de recaídas media de 1.3±0.6 durante ese período. En el seguimiento a 12 meses, el 75% estuvo libre de recaídas clínicas y el 91%, libre de nuevas lesiones en RM. Tres pacientes interrumpieron el tratamiento durante el seguimiento (3,7%). La persistencia al tratamiento observada durante el primer año de seguimiento fue de 338±24 días. Conclusión: Nuestro estudio está en línea con los datos provenientes de ensayos clínicos aleatorizados previos y estudios recientes del mundo real que describen la efectividad de los perfiles de pacientes y la persistencia al tratamiento con ocrelizumab en pacientes con EM en Latinoamérica.

Resumo Alterações ambientais causadas pelo homem têm levado à emergência de doenças transmitidas por vetores no mundo. Carrapatos são vetores conhecidos de vários patógenos de importância médica e veterinária, tendo sido reportado nas últimas décadas um grande número de enfermidades virais emergentes transmitidas por eles (vírus da Febre Hemorrágica da Crimeia-Congo, vírus Powassan, vírus da Encefalite, vírus Heartland e vírus da Síndrome da Febre Trombocitopênica Severa). Infelizmente, poucos estudos envolvendo a pesquisa de vírus em carrapatos foram conduzidos na América do Sul até o momento, e nas últimas décadas um elevado número de enfermidades virais emergentes transmitidas por estes artrópodes foi relatado. Com o objetivo de investigar a presença de flavivírus e orthobunyavírus em carrapatos, foi conduzida uma análise molecular em espécimes coletados no estado de Minas Gerais, Brasil. Em nenhum carrapato foi detectada a presença de Flavivirus, no entanto, em 8 espécimes do gênero Amblyomma, foi detectada a presença de Orthobunyavirus, dos quais um espécime foi positivo para Bunyamwera orthobunyavirus. Novos estudos relacionados à ecologia de doenças zoonóticas, incluindo tentativas de isolamento viral, sequenciamento completo do genoma e caracterização biológica, são necessários. Desta forma, será possível ter uma base sobre os riscos da transmissão de vírus patogênicos por carrapatos em nosso continente, uma vez que até agora isso é desconhecido.

Abstract Due to anthropic environmental changes, vector-borne diseases are emerging worldwide. Ticks are known vectors of several pathogens of concern among humans and animals. In recent decades, several examples of tick-borne emerging viral diseases have been reported (Crimean Congo hemorrhagic fever virus, Powassan virus, encephalitis virus, heartland virus, severe fever with thrombocytopenia syndrome virus). Unfortunately, few studies addressing the presence of viruses in wild ticks have been carried out in South America. With the aim of detecting flaviviruses and orthobunyaviruses in ticks, we carried out molecular detection in wild ticks collected in the state of Minas Gerais, Brazil. No Flavivirus-positive ticks were detected; however, we detected activity of Orthobunyavirus in 8 Amblyomma tick specimens. One of those individuals was positive for Bunyamwera orthobunyavirus, which represents the first report of this virus among ticks in South America. Further studies related to the ecology of zoonotic diseases are needed to increase knowledge of this topic, including attempts at viral isolation, full genome sequencing and biological characterization. In this way, we will obtain a better picture of the real risk of ticks as a vector for viral diseases for humans and animals on our continent, where no tick-borne viral disease is known to occur.

Resumo Algumas espécies de Rickettsia transmitidas por carrapatos são reconhecidos como patógenos humanos na Argentina. Este presente trabalho avaliou a infecção por Rickettsia em carrapatos coletados em aves passeriformes, durante 2011-2012, em duas ecorregiões da Argentina. Os carrapatos foram processados pela reação em cadeia da polimerase (PCR) e sequenciamento de DNA de dois genes de Rickettsia: gltA e ompA. Ao todo, 594 amostras de carrapatos (532 larvas e 62 ninfas), representando pelo menos 4 espécies (Amblyomma tigrinum, Ixodes pararicinus, Haemaphysalis juxtakochi, Haemaphysalis leporispalustris), foram avaliadas. Pelo menos uma larva de A. tigrinum, coletada de Coryphospingus cucullatus no Chaco Seco, estava infectada com Rickettsia parkeri, enquanto pelo menos 12 larvas e 1 ninfa de I. pararicinus, coletadas de Troglodytes aedon, Turdus amaurochalinus, Turdus rufiventris, C. cucullatus e Zonotrichia capensis estavam infectadas com Rickettsia sp., geneticamente relacionada a vários endossimbiontes riquetsiais de carrapatos do complexo Ixodes ricinus. R. parkeri é reconhecidamente um patógeno humano em alguns países americanos, incluindo a Argentina, onde um estudo recente incriminou A. tigrinum como um provável vetor. Aves poderiam desempenhar um papel importante na dispersão de carrapatos A. tigrinum infectados por R. parkeri. Em adição, relata-se pela primeira vez a infecção por Rickettsia em I. pararicinus.

Abstract Several tick-borne Rickettsia species are recognized human pathogens in Argentina. Here we evaluated rickettsial infection in ticks collected on passerine birds during 2011-2012 in two eco-regions of Argentina. The ticks were processed by molecular analysis through polymerase chain reaction (PCR) detection and DNA sequencing of fragments of two rickettsial genes, gltA and ompA. A total of 594 tick specimens (532 larvae and 62 nymphs), representing at least 4 species (Amblyomma tigrinum, Ixodes pararicinus, Haemaphysalis juxtakochi, Haemaphysalis leporispalustris), were evaluated. At least one A. tigrinum larva, collected on Coryphospingus cucullatus in Chaco Seco, was infected with Rickettsia parkeri, whereas at least 12 larvae and 1 nymph of I. pararicinus, collected from Troglodytes aedon, Turdus amaurochalinus, Turdus rufiventris, C. cucullatus and Zonotrichia capensis, were infected with an undescribed Rickettsia agent, genetically related to several rickettsial endosymbionts of ticks of the Ixodes ricinus complex. R. parkeri is a recognized human pathogen in several American countries including Argentina, where a recent study incriminated A. tigrinum as the potential vector of R. parkeri to humans. Birds could play an important role in dispersing R. parkeri-infected A. tigrinum ticks. Additionally, we report for the first time a rickettsial agent infecting I. pararicinus ticks.

RESUMEN La producción de áridos de residuos mixtos reciclados genera un elevado contenido de partículas por debajo de 63 µm. Este material puede ocasionar un incremento de la demanda de agua, sin embargo, pueden contribuir a rellenar espacios entre los granos de cemento. El presente trabajo evalúa la influencia del material por debajo 63 µm de áridos reciclados mixtos en las propiedades de hormigones y morteros. La actividad puzolánica medida por calorimetría isotérmica fue muy baja. El uso del 6% del material en morteros incrementa la demanda de agua, ocasiona una reducción de la resistencia, pero disminuye la porosidad efectiva de la matriz e incrementa la densidad de la ITZ. Los ensayos de expansión por álcalis en morteros mostraron una reducción de la porosidad conectada de la matriz. La misma tendencia fue observada en el hormigón. La contribución beneficiosa de dicha fracción puede compensar los problemas en la reología y en las propiedades mecánicas.

ABSTRACT Recycled aggregates from mixed recycled wastes have a high content of particles with size under 63 µm. This material is generally considered undesirable, since it increases water demand. However, these fines could fill out gaps between cement grains and increase packing density. The present work assesses the influence of fines under 63 µm on mortar and concrete made with mixed recycled aggregates. Pozzolanic activity of the powder, measured by isothermal calorimetry proves to be very low, so the material acts basically as a filler. Mortars with 6% of this fine material have a higher water demand, and thus a reduced compressive strength. However, the fine material contributes to decrease the effective porosity and increases the density of the matrix. This effect could help improving durability of the cementitious matrix. Alkalis tests carried out on mortars having 6% of fines under 63 µm show that expansion is reduced, and the probable cause is the refinement of the pore structure through the increased packing density. Observations of polished section of concrete having 6% of fines under 63 µm made with at SEM, coupled with image processing, show a densification of the ITZ around the aggregates, possibly due to the contribution of the very fine fraction to packing density. The beneficial contribution of the very fine fraction could compensate problems with rheology and mechanical properties assessed in mortars and concrete.

Abstract Background Clostridium difficile infections caused by the NAP1/B1/027 strain are more severe, difficult to treat, and frequently associated with relapses. Methods A case–control study was designed to examine a C. difficileinfection (CDI) outbreak over a 12-month period in a Mexican hospital. The diagnosis of toxigenic CDI was confirmed by real-time polymerase chain reaction, PCR (Cepheid Xpert C. difficile/Epi). Results During the study period, 288 adult patients were evaluated and 79 (27.4%) patients had confirmed CDI (PCR positive). C. difficilestrain NAP1/B1/027 was identified in 31 (39%) of the patients with confirmed CDI (240 controls were included). Significant risk factors for CDI included any underlying disease (p < 0.001), prior hospitalization (p < 0.001), and antibiotic (p < 0.050) or steroid (p < 0.001) use. Laboratory abnormalities included leukocytosis (p < 0.001) and low serum albumin levels (p < 0.002). Attributable mortality was 5%. Relapses occurred in 10% of patients. Risk factors for C. difficileNAP1/B1/027 strain infections included prior use of quinolones (p < 0.03). Risk factors for CDI caused by non-027 strains included chronic cardiac disease (p < 0.05), chronic renal disease (p < 0.009), and elevated serum creatinine levels (p < 0.003). Deaths and relapses were most frequent in the 027 group (10% and 19%, respectively). Conclusions C. difficile NAP1/BI/027 strain and non-027 strains are established pathogens in our hospital. Accordingly, surveillance ofC. difficile infections is now part of our nosocomial prevention program.

St. Louis encephalitis virus (SLEV) and West Nile virus (WNV) present ecological and antigenic similarities and are responsible for serious human diseases. In addition, WNV is a significant pathogen in terms of equine health. The purpose of our study was to analyse the seroprevalence of SLEV and WNV in equine sera collected in Santa Fe Province, Argentina. The seroprevalence determined using the plaque reduction neutralisation test was 12.2% for SLEV, 16.2% for WNV and 48.6% for a combination of both viruses. These results provide evidence of the co-circulation of SLEV and WNV in equines in Santa Fe.

BACKGROUND: Cerebral toxoplasmosis (CT) continues to cause significant morbidity and mortality in human immunodeficiency virus (HIV)-infected patients in Brazil. In clinical practice, the initial diagnosis is usually presumptive and alternative diagnosis tools are necessary. Our objective was to evaluate whether the detection of high titers of IgG anti-Toxoplasma gondii and T. gondii DNA in blood samples are associated with the diagnosis of CT. METHODS: In this case-control study we included 192 patients with HIV-1 infection: 64 patients with presumptive CT (cases) and 128 patients with other diseases (controls). Blood samples to perform indirect immunofluorescense reaction (IFI) to detect anti-T. gondii IgG antibodies and polymerase chain reaction (PCR) were collected before or within the first three days of anti-Toxoplasma therapy. Two multivariate logistic regression models were performed: one including the variable qualitative serology and another including quantitative serology. RESULTS: In the first model, positive IgG anti-T. gondii (OR 4.7, 95% CI 1.2-18.3; p = 0.027) and a positive T. gondii PCR result (OR 132, 95% CI 35-505; p < 0.001) were associated with the diagnosis. In the second model, IgG anti-T. gondii titres > 1:1024 (OR 7.6, 95% CI 2.3-25.1; p = 0.001) and a positive T. gondii PCR result (OR 147, 95% CI 35-613; p < 0.001) were associated with the diagnosis. CONCLUSIONS: Quantitative serology and molecular diagnosis in peripheral blood samples were independently associated with the diagnosis of CT in HIV-infected patients. These diagnostic tools can contribute to a timely diagnosis of CT in settings where Toxoplasma infection is common in the general population.

O virus Una (Togaviridae) tem ampla distribuição na América do Sul, detectando-se infecções até hoje em mosquitos e hospedeiros vertebrados (humanos, aves e cavalos). Mediante a realização do teste de neutralização em soros humanos provenientes de indivíduos entre 44 e 89 anos, da cidade de Córdoba, foi detectada uma prevalência de 3,8% (3/79) de anticorpos para o vírus UNA. Nenhum soro apresentou anticorpos para o vírus Mayaro. Os títulos foram baixos demonstrando-se a presença de infecção passada. Dados epidemiológicos indicam que a infecção ocorreu em áreas rurais da província de Córdoba (centro da Argentina). Os dados aqui expostos representam o primeiro registro de infecção de humanos por vírus Una na República Argentina.

Una virus (UNAV), Togaviridae family, is widely distributed in South America, where infections have been detected in mosquitoes and vertebrate hosts (humans, birds and horses). We analyzed human sera from Córdoba inhabitants aged 44 to 89 years and using a neutralization test, we found a prevalence of UNAV antibodies of 3.8% (3/79). The low titers detected suggest past infections probably acquired in rural areas of the Province of Córdoba (central Argentina). None sera were found positive for MAYV neutralizing antibodies. This is the first report of human infections by UNAV in Argentina.