Photoindentation: A New Route to Understanding Dislocation Behavior in Light.

It was recently found that extremely large plasticity is exhibited in bulk compression of single-crystal ZnS in complete darkness. Such effects are believed to be caused by the interactions between dislocations and photoexcited electrons and/or holes. However, methods for evaluating dislocation behavior in such semiconductors with small dimensions under a particular light condition had not been well established. Here, we propose the "photoindentation" technique to solve this issue by combining nanoscale indentation tests with a fully controlled lighting system. The quantitative data analyses based on this photoindentation approach successfully demonstrate that the first pop-in stress indicating dislocation nucleation near the surface of ZnS clearly increases by light irradiation. Additionally, the room-temperature indentation creep tests show a drastic reduction of the dislocation mobility under light. Our approach demonstrates great potential in understanding the light effects on dislocation nucleation and mobility at the nanoscale, as most advanced technology-related semiconductors are limited in dimensions.

[A Case of Robot-Assisted Abdominoperineal Resection with Prostatectomy for Locally Advanced Rectal Cancer].

The patient was referred to our hospital because of bloody stool and anorectal pain, and a colonoscopy revealed a tumor in the lower rectum. Although no distant metastasis was found, the tumor was suspected to have invaded the distal prostate. Neoadjuvant chemoradiotherapy(45 Gy/25 Fr with S-1)resulted in tumor shrinkage and symptomatic improvement, however, the primary tumor remained in close proximity to the prostate and urethra. Thus, we performed a robot-assisted abdominoperineal resection and Retzius-sparing prostatectomy in collaboration with the urology department. The surgical margins were negative and radical resection was achieved. Although minor vesicourethral anastomotic leakage was observed, it recovered conservatively. The patient has been alive 1 year postoperatively without recurrence. The patient initially had urinary incontinence, but it gradually improved. Although a total pelvic resection could have been considered, the robot-assisted surgery made it possible to preserve the urinary tract. The future application of robot-assisted surgery in extended surgery is expected.

[A Case of Rectal Cancer with Disseminated Intravascular Coagulation Successfully Treated with Emergent Chemotherapy].

A 70's woman complaining blood stool and lower abdominal pain visited a local doctor and was given the diagnosis of rectal cancer by colonoscopy. CT, MRI, and bone scintigraphy revealed multiple lymph node and bone metastasis and peritoneal dissemination. She had developed disseminated intravascular coagulation(DIC)during hospitalization, and the cause was considered to be disseminated carcinomatosis of the bone marrow. Thus, we emergently started chemotherapy with mFOLFOX6, in conjunction with anticoagulation therapy, and the DIC was resolved 11 days after the introduction. Partial response was achieved and the chemotherapy has been continued after 5 months from the onset of the DIC. Since the prognosis of solid tumor patients who developed DIC has been reported to be extremely poor, prompt introduction of chemotherapy should be considered.