There are a number of ways to reduce the concentration of inclusions. In order to reduce oxide formation the metal can be melted with a flux, in a vacuum, or in an inert atmosphere. Other ingredients can be added to the mixture to cause the dross to float to the top where it can be skimmed off before the metal is poured into the mould. If this is not practical, then a special ladle that pours the metal from the bottom can be used. Another option is to install ceramic filters into the gating system. Otherwise swirl gates can be formed which swirl the liquid metal as it is poured in, forcing the lighter inclusions to the center and keeping them out of the casting. If some of the dross or slag is folded into the molten metal then it becomes an entrainment defect. Metallurgical defects
There are two defects in this category: hot tears and hot spots. Hot tears, also known as hot cracking, are failures in the casting that occur as the casting cools. This happens because the metal is weak when it is hot and the residual stresses in the material can cause the casting to fail as it cools. Proper mould design prevents this type of defect.Hot spots are sections of casting which have cooled down more slowly than the surrounding material due to higher volume than its surrounding. This causes abnormal shrinkage in this region, which can lead to porosity and cracks.
In ALK-positive ALCL, a portion of the ALK gene has merged with another site on the same or different chromosome to form a chimeric gene consisting of part of the new site and part of the ALK gene coding for ALKs activity. This chimeric gene overproduces a fusion protein with excessive ALK activity. ALK is a serine/threonine-specific protein kinase that activities PI3K/AKT/mTOR, Ras-activated ERKs, Janus kinase-activated STAT proteins, and other cell signaling pathways as well as the expression of various genes by epigenetic mechanisms. Activations of these signaling pathways and genes may stimulate cell growth, proliferation, survival, and/or other behaviors that promote malignancy. ALK-negative ALCL, while not involving ALK translocations, has, in a variable percentage of cases, various translocations, rearrangements, and mutations that may contribute to its development.pcALCL and BIA-ALCL are far less aggressive lymphomas that tend to be localized to one or a very few sites. pcALCL presents as a single or, less commonly, multifocal skin papules or tumors that typically are limited to the dermis without infiltrating to the subcutaneous tissues or spreading to other sites. Its neoplastic cells may contain some gene translocations including, in very rare cases, ones with the ALK gene that are similar to those in ALK-positive ALCL. BIA-ALCL is caused by and develops around a breast implant. It typically presents many years after the surgical implantation as a deformation, textural change, and/or pain emanating in the area around implanted breast. In most cases, the disease is localized to the involved breast.