Clinical and histological challenge in the differential diagnosis of diffuse alopecia: female androgenetic alopecia, telogen effluvium and alopecia areata - part II Desafio clínico e histológico no diagnóstico diferencial de alopecia difusa: alopecia androgenética, eflúvio telógeno e alopecia areata - parte II

Diffuse alopecia is mainly caused by telogen effluvium, diffuse androgenetic alopecia (femalepattern hair loss) and diffuse alopecia areata. Differential diagnosis between the three disorders may be difficult in several occasions. In this second part of our study, chronic telogen effluvium and diffuse alopecia areata are discussed in detail, including clinical, dermoscopic and histological aspects. A flowchart presents a practical and objective differential diagnostic approach to diffuse alopecia.<br>A alopecia difusa tem como principais causas eflúvio telógeno, alopecia androgenética difusa (alopecia androgenética de padrão feminino) e alopecia areata difusa. Em muitas ocasiões o diagnóstico diferencial entre as três entidades é difícil. Na segunda parte deste artigo se discute em mais detalhes as características clínicas, dermatoscópicas e histológicas do eflúvio telógeno crônico e da alopecia areata difusa. Uma maneira prática e objetiva de abordagem diagnóstica da alopecia difusa é apresentada através de um fluxograma

Evaluation of surface integrity after high energy machining with EDM, Laser Beam Machining and Abrasive Water Jet Machining of Alloy 718

Development of future aero engine components based on new design strategies utilising topological optimisation and additive manufacturing has in the past years become a reality. This allows for designs that involve geometries of "free form" surfaces and material combinations that could be difficult to machine using conventional milling. Hence, alternative manufacturing routes using non-conventional high energy methods are interesting to explore. In this investigation, the three high energy machining methods abrasive water jet machining (AWJM), electrical discharge machining (EDM) and laser beam machining (LBM) have been compared in terms of surface integrity to the reference, a ball nosed end milled surface. The results showed great influence on the surface integrity from the different machining methods. It was concluded that AWJM resulted in the highest quality regarding surface integrity properties with compressive residual stresses in the surface region and a low surface roughness with texture from the abrasive erosion. Further, it was shown that EDM resulted in shallow tensile residual stresses in the surface and an isotropic surface texture with higher surface roughness. However, even though both methods could be considered as possible alternatives to conventional milling they require post processing. The reason is that the surfaces need to be cleaned from either abrasive medium from AWJM or recast layer from EDM. It was further concluded that LBM should not be considered as an alternative in this case due to the deep detrimental impact from the machining process.KeywordsFirst Online: 05 October 2018</p