Study of Different Aging Conditions for Analysis of Microstructure and Mechanical Properties of F357 Alloy Fabricated in LPBF Printer

Aluminum F357 is a widely used material for casting in aerospace and additive manufacturing industry. Heat treatments are commonly applied to some aluminum alloys to modify its properties. With a further study on the aging and performance of the F357 with 3D printing technology, several industries benefit of this, military, automotive and aerospace are some examples, because the numerous components casted in service. This work presents mechanical properties of F357 specimens fabricated with EOS technology and subjected to heat treatments. Heat treatments conditions were applied to tensile specimens and tested. Furthermore, the specimens were subjected to artificial thermal aging for 100 h and 1000 h at two different temperatures (285 ºF and 350 ºF), and their mechanical properties were also determined. Finally, remarks on the comparison between the heat treatments and the effect of thermal aging on the microstructures and mechanical properties of the specimens will be presented.Mechanical Engineerin

From nonassociativity to solutions of the KP hierarchy

A recently observed relation between 'weakly nonassociative' algebras A (for which the associator (A,A^2,A) vanishes) and the KP hierarchy (with dependent variable in the middle nucleus A' of A) is recalled. For any such algebra there is a nonassociative hierarchy of ODEs, the solutions of which determine solutions of the KP hierarchy. In a special case, and with A' a matrix algebra, this becomes a matrix Riccati hierarchy which is easily solved. The matrix solution then leads to solutions of the scalar KP hierarchy. We discuss some classes of solutions obtained in this way.Comment: 7 pages, 4 figures, International Colloquium 'Integrable Systems and Quantum Symmetries', Prague, 15-17 June 200

Distinct strains of the re‐emergent Cassava common mosaic virus (Genus: Potexvirus) infecting cassava in Argentina

Cassava common mosaic disease (CCMD) has been reported in all regions where cassava is grown in the Americas and the causal agent, Cassava common mosaic virus (CsCMV) was identified as a mechanically transmitted potexvirus (Fam. Alphaflexiviridae). In Argentina, cassava is grown mainly in the North East region (NEA) that shares borders with Brazil and Paraguay. Increasing incidences of CCMD were observed during the years 2014 to 2016 associated to severe leaf mosaic symptoms and yield reductions where the occurrence of CsCMV was confirmed by RT-PCR and sequencing. In this work we successfully purified the virus and developed a double-antibody sandwich (DAS) ELISA test from an Argentinean field-isolate of CsCMV, to extend the diagnostics of the disease. A collection of 726 samples was screened and CsCMV was detected with 100% prevalence in the NEA region. Additional co-infecting viruses were detected in some plants (64.4%); in these, CCMD symptoms correlated with CsCMV only, although more severe symptoms could be observed in mixed infected plants. Sequence analysis of the conserved RdRp domain showed a wider diversity of CsCMV isolates. Interestingly, a separate cluster was formed by sequences isolates from NEA samples which only share 77.1 to 80.3% nucleotide identity with the other clusters. These results indicated the presence of mixed strains occurring in the NEA region and suggest the presence of geographically distinct strains of CsCMV in South America

Pigmentación de un hongo celulolítico asociado al suelo forestal de Nothofagus pumilio

Fil: Bárcena, Alejandra. Instituto de Fisiología Vegetal (INFIVE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Medina, R.. Instituto de Fisiología Vegetal (INFIVE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Elíades, Lorena Alejandra. División Instituto Spegazzini. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Cabello, Marta Noemí. División Instituto Spegazzini. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Pancotto, V.A.. Centro Austral de Investigaciones Científicas (CADIC-CONICET); ArgentinaFil: Arambarri, Angélica Margarita. División Instituto Spegazzini. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Balatti, Pedro Alberto. Instituto de Fisiología Vegetal (INFIVE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Saparrat, Mario Carlos Nazareno. Instituto de Fisiología Vegetal (INFIVE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

A comparison of the mechanical behavior of AlSi7Mg alloy produced through additive manufacturing and subjected to different heat treatment and aging conditions

The versatility and adaptability of Aluminum F357 (AlSi7Mg) make it a popular material in the aerospace and defense industries. In this study, two different laser powder bed fusion systems, EOS M290, and SLM 280HL were used to create specimens of Aluminum F357. These specimens were subjected to five different heat treatments: As-built, stress relief (SR), hot isostatic pressing (HIP), T6, and HIP+T6) as per ASTM F3318-18 standard. The printed specimens were then reduced to tensile bars through machining and tested for mechanical properties as per ASTM E28 using an MTS Landmark tensile testing system. In addition to the mechanical behavior analysis, the study used a JEOL JSM-IT500 SEM to observe and document the fracture produced by the tensile test and a Qness 30 CHD Master+ microhardness testing system to obtain hardness (HV) values of the alloy. The results showed that specimens fabricated in the Z direction had a tendency for higher yield strengths of approximately 225 MPa and although these results were similar between LPBF systems some variances can still be seen. However, these differences between the LPBF systems were observed to be partially mitigated by heat treatments. In conclusion, this study highlights the significance of heat treatment on the mechanical properties of Aluminum F357. The results provide valuable information for the aerospace and defense industries to optimize their processes and produce high-quality components. The compatibility of LPBF system fabrication and the mitigation of differences observed between LPBF machines by heat treatments, further demonstrate the potential of this method for producing high-quality Aluminum F357 components.Mechanical Engineerin

Consenso colombiano de atención, diagnóstico y manejo de la infección por SARS-COV-2/COVID-19 en establecimientos de atención de la salud Recomendaciones basadas en consenso de expertos e informadas en la evidencia

The “Asociación Colombiana de Infectología” (ACIN) and the “Instituto de Evaluación de Nuevas Tecnologías de la Salud” (IETS) created a task force to develop recommendations for Covid 19 health care diagnosis, management and treatment informed, and based, on evidence. Theses reccomendations are addressed to the health personnel on the Colombian context of health services. © 2020 Asociacion Colombiana de Infectologia. All rights reserved

Wnt signalling and cancer stem cells

[Abstract] Intracellular signalling mediated by secreted Wnt proteins is essential for the establishment of cell fates and proper tissue patterning during embryo development and for the regulation of tissue homeostasis and stem cell function in adult tissues. Aberrant activation of Wnt signalling pathways has been directly linked to the genesis of different tumours. Here, the components and molecular mechanisms implicated in the transduction of Wnt signal, along with important results supporting a central role for this signalling pathway in stem cell function regulation and carcinogenesis will be briefly reviewed.Ministerio de Ciencia e Innovación; SAF2008-0060

Analysis of extemporaneous oral liquid from commercially available drugs in hospital

ABSTRACT The objective of this study was to identify drugs that received dose adjustments (DA) and pharmaceutical alternatives (PA) that avoid DA, and calculate the economic percentage of this replacement. A descriptive, observational and cross-sectional study was performed in a second level hospital. The pharmacy and nursing services was accompanied to identify the drugs that received DA and the compounding techniques. After identifying all the drugs that received DA, was identified in the Brazilian market the corresponding pharmaceutical alternative, with the Drugs Price List of Brazilian Health Regulatory Agency. For those drugs that was not available any PA, was performed a research of studies that describe compounding techniques in international scientific databases. Was identify 88 drugs that received DA, and these, 50 do not have any PA. Were identified compounding techniques to 40 drugs. Although any drug has your own particularity of compounding, the compounding techniques can be grouped in five categories. The standardization of 29 drugs can reduce in 28% the DA procedure and cost saving of 34,85%/month. We can conclude that every three drugs prescribed, one received DA and every three DA, one can be avoided by the selection of 29 PA, saving cost as well. The use and standardization of five techniques would attend the pharmaceutics recommendations for better dissolution, bioavailability and patient safety

Registro ACESUR: atención de pacientes adultos con crisis epilépticas en servicios de urgencias: diferencias entre primer episodio y recurrencia

Objetivo. Describir las características y la atención recibida de pacientes adultos que consultan por crisis epiléptica (CE) en los servicios de urgencias hospitalarios (SUH), diferenciando entre primera crisis y recurrencia en epiléptico conocido. Método. ACESUR es un registro observacional de cohortes multipropósito, prospectivo y multicéntrico con un muestreo sistemático, los días pares de febrero y julio alternando con los impares de abril y octubre de 2017. Se incluyeron pacientes 18 años con diagnóstico de CE en los SUH. Se recogieron variables clínico-asistenciales de la visita índice de pacientes, distinguiendo entre primera CE y recurrencia en epiléptico. Resultados. El registro ACESUR recogió a 664 pacientes procedentes de 18 SUH españoles, 229 (34, 5%) con primera CE y 435 (65, 5%) con CE recurrentes. Los pacientes con primera CE fueron de mayor edad (p < 0, 001), presentaron motivos de consulta distintos (p < 0, 001) y requirieron más traslados en ambulancia (p < 0, 001). La atención recibida en el SUH fue diferente, en pacientes con primera CE se solicitó con mayor probabilidad una prueba complementaria específica (OR ajustada = 13, 94; IC95%:7, 29-26, 7; p < 0, 001) y se necesitó mayor hospitalización o estancia prolongada en el SUH (OR ajustada = 1, 69; IC95%:1, 11-2, 58; p = 0, 015). No hubo diferencias en cuanto al tratamiento farmacológico en fase aguda ni preventivo (OR ajustada = 1, 40; IC95%:0, 94-2, 09; p = 0, 096). Se inició tratamiento con fármacos antiepiépticos (FAE) en 100 pacientes (43, 7%) tras primera CE y se reinició o modificó añadiendo nuevo FAE en 142 pacientes (32, 6%) con CE recurrentes. Conclusiones. Las características clínicas y la atención recibida de pacientes adultos con primera CE en SUH en España difieren de las recurrencias en epiléptico conocido. Objective. To describe the characteristics of care received by patients who come to the emergency department with a first epileptic seizure versus a recurrent seizure in a patient with diagnosed epilepsy. Methods. ACESUR (Acute Epileptic Seizures in the Emergency Department) is a prospective multicenter, multipurpose registry of cases obtained by systematic sampling on even days in February and July 2017 and on odd days in April and October 2017. Patients were aged 18 years or older and had an emergency department diagnosis of epileptic seizure. We recorded clinical variables and details related to care given during each patient''s visit, including whether the event was a first or recurrent seizure. Results. A total of 664 patients attended by 18 Spanish emergency departments were entered into the ACESUR registry. Two hundred twenty-nine (34.5%) were first seizures and 435 (65.5%) were recurrences. Patients who were attended for first seizures were older, consulted for a wider variety of reasons, and were transported in ambulances (P<.001, all comparisons). Care received differed between patients with first seizures versus recurrent seizures. Specific complementary testing was more likely in patients with first seizures (adjusted odds ratio [aOR], 13.94; 95% CI, 29-26.7; P<.001), and they were more often hospitalized or stayed longer in the emergency department, (aOR, 1.69; 95% CI, 1.11-2.58; P=.015). Pharmacologic treatment did not differ between the groups, either in the acute phase or for prevention (aOR, 1.40; 95% CI, 0.94-2.09; P=.096). Antiepileptic drugs were given to 100 patients (43.7%) after a first seizure and were restarted or changed in 142 patients with recurrent seizure (32.6%). Conclusions. The clinical characteristics of adults attended for a first epileptic seizure differ from those of patients with diagnosed epilepsy who were attended for recurrent seizures in Spain. The care received also differs

The electromagnetic counterpart of the binary neutron star merger LIGO/Virgo GW170817. I. Discovery of the optical counterpart using the Dark Energy Camera

We present the Dark Energy Camera (DECam) discovery of the optical counterpart of the first binary neutron star merger detected through gravitational wave emission, GW170817. Our observations commenced 10.5 hours post-merger, as soon as the localization region became accessible from Chile. We imaged 70 deg2 in the i and z bands, covering 93% of the initial integrated localization probability, to a depth necessary to identify likely optical counterparts (e.g., a kilonova). At 11.4 hours post-merger we detected a bright optical transient located 10:600 from the nucleus of NGC4993 at redshift z = 0:0098, consistent (for H0 = 70 km s-1 Mpc-1) with the distance of 40±8 Mpc reported by the LIGO Scientific Collaboration and the Virgo Collaboration (LVC). At detection the transient had magnitudes i=17.3 and z=17.4, and thus an absolute magnitude of Mi = -15.7, in the luminosity range expected for a kilonova. We identified 1,500 potential transient candidates. Applying simple selection criteria aimed at rejecting background events such as supernovae, we find the transient associated with NGC4993 as the only remaining plausible counterpart, and reject chance coincidence at the 99.5% confidence level. We therefore conclude that the optical counterpart we have identified near NGC4993 is associated with GW170817. This discovery ushers in the era of multi-messenger astronomy with gravitational waves, and demonstrates the power of DECam to identify the optical counterparts of gravitational-wave sources