The design, development and documentation of software. See software engineer, systems analysis & design, programming, object-oriented programming, software metrics, CASE and Systemantics.
Overview. Posttransplant lymphoproliferative disease (PTLD) is an unusual entity that has many features of an immune system malignancy. It is characterized by uncontrolled proliferation of lymphoid lineage cells (typically B cells, rarely non-B lineage) in a context of posttransplant immunosuppression.
What It Is. A partial thromboplastin time (PTT) test measures how long it takes for a clot to form in a blood sample. A clot is a thick lump of blood that the body produces to seal leaks, wounds, cuts, and scratches and prevent excessive bleeding. The blood's ability to clot involves platelets (also called thrombocytes) and proteins called clotting factors.