Nano-ridge engineering (NRE) is a novel heteroepitaxial approach for the monolithic integration of lattice-mismatched III-V devices on Si substrates. It has been successfully applied to GaAs for the realization of nano-ridge (NR) laser diodes and heterojunction bipolar transistors on 300 mm Si wafers. In this report we extend NRE to GaSb for the integration of narrow bandgap heterostructures on Si. GaSb is deposited by selective area growth in narrow oxide trenches fabricated on 300 mm Si substrates to reduce the defect density by aspect ratio trapping. The GaSb growth is continued and the NR shape on top of the oxide pattern is manipulated via NRE to achieve a broad (001) NR surface. The impact of different seed layers (GaAs and InAs) on the threading dislocation and planar defect densities in the GaSb NRs is investigated as a function of trench width by using transmission electron microscopy (TEM) as well as electron channeling contrast imaging (ECCI), which provides significantly better defect statistics in comparison to TEM only. An InAs/GaSb multi-layer heterostructure is added on top of an optimized NR structure. The high crystal quality and low defect density emphasize the potential of this monolithic integration approach for infrared optoelectronic devices on 300 mm Si substrates.
BackgroundThe purpose of this study was to clarify the oncological safety of reduced‐port laparoscopic surgery (single‐incision plus one port) (RPS) for patients with rectal cancer.MethodsThe clinicopathological data of 63 selected patients with clinical Stage I‐III (T1‐3 and N0‐2) rectal cancer who underwent RPS of radical anterior resection between 2012 and 2017 were retrospectively analyzed. The median distance of tumor from anal verge was 11 cm. Ordinarily, a multiport platform with three channels was placed in the 3‐cm umbilical incision, and another 5‐ or 12‐mm port was placed in the right lower abdomen.ResultsThe median operative time, amount of intraoperative bleeding, number of harvested lymph nodes, and length of distal margin were 272 min, 10 mL, 22 nodes, and 4.0 cm, respectively, and there was one (2%) patient with involvement of the radial margin. There were eight patients (13%) who required additional ports, and one patient (2%) who converted to open surgery. Intra‐ and postoperative complications occurred in one (2%) and 12 patients (19%), respectively. The median length of postoperative hospital stay was 8 days. The median follow‐up period was 79 months, and incisional hernia was observed in 3 (5%) patients at the platform site not the port site, and cancer recurrence occurred in four patients (6%). The 5‐year relapse‐free and overall survival rates were 100% and 100% in the patients with pathological Stage I disease, 94% and 100% in the patients with pathological Stage II disease, and 83% and 89% in the patients with pathological Stage III disease, respectively.ConclusionRPS in the selected patients with rectal cancer, performed by an expert laparoscopic surgeon, may be technically safe and oncologically acceptable as well as multiport laparoscopic surgery.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.