Impact of adjuvant treatment modalities on survival outcomes in curatively resected pancreatic and periampullary adenocarcinoma

Background: We examined the impact of adjuvant modalities on resected pancreatic and periampullary adenocarcinoma (PAC). Methods: A total of 563 patients who were curatively resected for PAC were retrospectively analyzed between 2003 and 2013. Results: Of 563 patients, 472 received adjuvant chemotherapy (CT) alone, chemoradiotherapy (CRT) alone, and chemoradiotherapy plus chemotherapy (CRT-CT) were analyzed. Of the 472 patients, 231 were given CRT-CT, 26 were given CRT, and 215 were given CT. The median recurrence-free survival (RFS) and overall survival (OS) were 12 and 19 months, respectively. When CT and CRT-CT groups were compared, there was no significant difference with respect to both RFS and OS, and also there was no difference in RFS and OS among CRT-CT, CT and CRT groups. To further investigate the impact of radiation on subgroups, patients were stratified according to lymph node status and resection margins. In node-positive patients, both RFS and OS were significantly longer in CRT-CT than CT. In contrast, there was no significant difference between groups when patients with node-negative disease or patients with or without positive surgical margins were considered. Conclusions: Addition of radiation to CT has a survival benefit in patients with node-positive disease following pancreatic resection. © 2015, Chinese Journal of Cancer Research. All rights reserved

Hydrogenic impurity states in CdSe/ZnS and ZnS/CdSe core-shell nanodots with dielectric mismatch

Within the effective mass approximation we theoretically studied the electronic properties of CdSe/ZnS and ZnS/CdSe core-shell quantum dots surrounded by wide-gap dielectric materials. The finite element method is used to obtain the lowest impurity levels and the carrier spatial distribution within the dot. We found that in these zero-dimensional semiconductor structures the electron energy is sensitively dependent on the dielectric constants of the embedding and on the heterostructure geometry. The influence of polarization charges on the binding energy of hydrogenic impurities off-center located is also investigated. The results suggest that in dielectrically modulated nanodots the donor energy can be tuned to a large extent by the structure design, the impurity position and a proper choice of the dielectric media