Resumen La inestabilidad microsatelital es causada por una alteración de los sistemas de reparación de apareamiento incorrecto, que puede afectar los microsatélites dentro de todo el genoma humano, produciendo errores en su replicación. Los estudios publicados, principalmente en la literatura inglesa, han encontrado que algunos tumores, como los gástricos, pueden expresar inestabilidad microsatelital. En la siguiente revisión de tema, se presenta una descripción de los sistemas de reparación de apareamientos incorrectos y su relación con la presencia de inestabilidad microsatelital en los tumores gástricos, así como su posible utilidad clínica, como factor asociado en la respuesta al tratamiento con inmunoterapia en los pacientes con dicha patología.

Abstract Microsatellite instability is caused by an alteration of the mismatch repair systems, which can affect microsatellites within the entire human genome, causing errors in their replication. Published studies, mainly in the English literature, have found that some tumors, such as gastric ones, can express microsatellite instability. In this review, a description of the mismatch repair systems and their relationship with the presence of microsatellite instability in gastric tumors is presented, as well as its possible clinical utility, as an associated factor in the response to immunotherapy treatment, in patients with gastric cancer.

Abstract Description: The COVID-19 pandemic poses an unprecedented challenge for urologic oncology and radiotherapy. Radiation oncology departments and international collaboration groups are sharing their management adaptations made in response to the pandemic. The present narrative review summarizes the current recommendations. Relevance: There is a need to define which patients are candidates for safe treatment delay until the pandemic is over or controlled, to reduce exposure to the virus in the healthcare personnel and patients. Conclusions: Telemedicine is recommended for follow-up visits. Active surveillance is the preferred treatment for patients with favorable intermediate risk. In greater risk disease, hormone therapy safely postpones radiotherapy up to 7 months. Radiosurgery is suggested in centers that have the necessary technology and previous experience. A moderately hypofractionated regimen is recommended if radiosurgery/ultra-hypofractionation is not available. Hypofractionation should be implemented if image-guided radiation therapy is already in place. Countries with low and middle-income economies face challenges in adopting the recommendations for prostate cancer management during the pandemic. Postponing treatment may result in the overwhelming of radiation oncology center capacity, after the pandemic.

Resumen: Descripción: El COVID-19 representa un desafío para la práctica de la urología oncológica y radioterapia. Departamentos y grupos de colaboración internacional de radio oncología están compartiendo sus adaptaciones de práctica en respuesta a la pandemia. Esta revisión narrativa resume las recomendaciones actuales. Relevancia: Existe la necesidad de definir qué pacientes son candidatos para un retraso seguro en el tratamiento hasta que la pandemia termine o se controle, de forma que se minimice la exposición del personal de salud y de los pacientes. Conclusiones: Se recomienda la telemedicina para visitas de seguimiento. La vigilancia activa es el tratamiento preferido para el riesgo intermedio favorable. En enfermedad de mayor riesgo, la hormonoterapia retrasa la radioterapia de forma segura hasta 7 meses. La radiocirugía se sugiere en centros con tecnología y experiencia previa. Se recomienda un régimen de hipofraccionamiento moderado si no se dispone de radiocirugía / ultra hipofraccionamiento. El hipofraccionamiento debe implementarse si las capacidades de IGRT ya están en su lugar. Los países de bajos y medianos ingresos enfrentan desafíos para adaptar las recomendaciones para el manejo del cáncer de próstata durante la pandemia. El aplazamiento del tratamiento puede exceder la capacidad de los centros de oncología radioterápica después de la pandemia.

The friction surfacing process of two deposited layers on two deposition surface conditions, i.e., a smooth interface and a rough interface, was investigated. The control parameter of the deposition process was the rod feed rate with the use of a conventional milling machine. Analyzes of the surface characterization and microstructural characterization along the produced deposits were performed. The interface strength of the substrate/deposit1 (smooth) and deposit1/deposit2 (rough) was evaluated by bending tests and the micro-hardness profile along the transverse section of the substrate/deposit1 and deposit1/deposit2. The bending tests revealed the presence of smalls delaminations with no evidence of fracture at the rough deposit1/deposit2 interface (D1/D2) with less predominance in the deposition condition 3B. This suggests that the combination of the travel speed of 5.5 mm/s and an increase in the consumable rod feed rate of (≥5.5 mm/s) increases the adhesive strength of the two produced interfaces.

The aim of this work was to produce deposits of AA6351-T6, reinforced with alumina (Al2O3) particles, over a substrate of AA5052-H32 through friction surfacing. AA6351-T6 consumable rods were drilled with one and two holes, which were filled with Al2O3 particles posteriorly. To perform the deposition, a conventional KONE KFE-3/BR milling machine was used. The results showed that Al2O3 particles increase the hardness values of the produced deposits when compared to those without particle addition. The coatings presented a fine equiaxed grain size distribution, once the grain refinement was nearly 48% lower than the as-received material. Moreover, deposit regions that showed finer grain boundaries also showed a higher volume fraction, which can be related to the particle stimulated phenomenon. Electron backscatter diffraction results showed the occurrence of low angle grain boundary substructures and lattice rotation, indicating that the material undergoes dynamic recrystallization during friction surfacing.