Clear Cell Odontogenic Carcinoma: a Clinicopathological and Immunocytochemical Analysis
PATHOLOGY & ONCOLOGY RESEARCH
Authors: Liu, Liu; Zhang, Jin-Wei; Zhu, Ni-Sha; Zhu, Yun; Guo, Bing; Yang, Xi-Hu
Abstract
Clear cell odontogenic carcinoma (CCOC) is a rare odontogenic tumor associated with aggressive clinical behavior, metastasis and low survival. To date, only 67 cases have been described in the English language literature, and an understanding of the behavior of CCOC has been based on limited case reports. The aim of the research was to further reveal the features of CCOC. We report 5 new cases of CCOC, with a mean age of 52.4 years. The clinical and histopathologic data of the disease obtained from earlier literature (95 cases) and the 5 new cases were analyzed. Data were extracted, including demographics, histopathologic findings, clinical presentation, primary treatment and outcomes. Immunohistochemical results revealed that the cancer is positive for AE1/AE3, EMA and CK19, negative for smooth muscle actin SMA, Vim and S-100. EWSR1 translocation was also observed in the new cases, which may help in the diagnosis of CCOC. Metastases of CCOC were rare, but the local recurrence rate of CCOC rose to 42%. The best treatment for patients with CCOC is wide local excision combined with regional lymph node dissection.
An iterative method for suboptimal control of a class of nonlinear time-delayed systems
INTERNATIONAL JOURNAL OF CONTROL
Authors: Mirhosseini-Alizamini, Seyed Mehdi; Effati, Sohrab
Abstract
This work presents an approximate solution method for the infinite-horizon nonlinear time-delay optimal control problem. A variational iteration method (VIM) is applied to design feedforward and feedback optimal controllers. By using the VIM, the original optimal control is transformed into a sequence of nonhomogeneous linear two-point boundary value problems (TPBVPs). The existence and uniqueness of the optimal control law are proved. The optimal control law obtained consists of an accurate linear feedback term and a nonlinear compensation term which is the limit of an adjoint vector sequence. The feedback term is determined by solving Riccati matrix differential equation. By using the finite-step iteration of a nonlinear compensation sequence, we can obtain a suboptimal control law. Simulation results demonstrate the validity and applicability of the VIM.