21-st and 22-nd homotopy groups of the n-th rotation group

We denote by Rn the n-th rotatoin group and by πk(Rn) the k-th homotopy group of Rn. We determine the group structures of the homotopy groups πk(Rn) for k=21 and 22 by use of the fibration Rn₊₁ rn→Sⁿ.ArticleJournal of the Faculty of Science Shinshu University 41: 1-28(2007)departmental bulletin pape

Differentiation of thyroid nodules using Tl-201 scintigraphy quantitative analysis and fine-needle aspiration biopsy.

We studied the differentiation of thyroid nodules using fine-needle aspiration biopsy (FNA) and Tl-201 scintigraphy quantitative analysis. One-hundred and thirty-one thyroid nodules were examined: 83 follicular lesions (58 benign and 25 malignant lesions) and 48 non-follicular lesions (8 benign and 40 malignant lesions). During Tl-201 scintigraphy examinations, an early and a delayed image were acquired 10 and 120 min after an intravenous injection, respectively. The T/N ratio (counts of nodular lesion/counts of contralateral normal thyroid tissue) of each image was calculated quantitatively. We assessed the ability of the Tl-201 scintigraphy and of the FNA analysis to differentiate benign and malignant lesions and determined the cut-off levels for the assays. For the follicular lesions, the area under the ROC (Receiver Operating Characteristic) curve (Az) for the Tl-201 scintigraphy data was greater than that for the FNA data. For the non-follicular lesions, the Az for the FNA data was greater than that for the Tl-201 scintigraphy data. We set cut-off levels at 1.370 for follicular lesions, and 1.070 for non-follicular lesions. The sensitivity and specificity were 76% and 82.7% for follicular lesions, and 90% and 87.5% for non-follicular lesions, respectively. The overall accuracy of the analysis was 84.0%.</p

Major Surgical Treatment of Osteoporotic Vertebral Fractures in the Elderly: A Comparison of Anterior Spinal Fusion, Anterior-Posterior Combined Surgery and Posterior Closing Wedge Osteotomy

Study DesignA retrospective study.PurposeTo clarify the differences among the three major surgeries for osteoporotic vertebral fractures based on the clinical and radiological results.Overview of LiteratureMinimally invasive surgery like balloon kyphoplasty has been used to treat osteoporotic vertebral fractures, but major surgery is necessary for severely impaired patients. However, there are controversies on the surgical procedures.MethodsThe clinical and radiographic results of patients who underwent major surgery for osteoporotic vertebral fracture were retrospectively compared, among anterior spinal fusion (group A, 9 patients), single-stage combined anterior-posterior procedure (group AP, 8 patients) and posterior closing wedge osteotomy (group P, 9 patients). Patients who underwent revision surgery were evaluated just before the revision surgery, and the other patients were evaluated at the final follow-up examination, which was defined as the end point of the evaluations for the comparison.ResultsThe operation time was significantly longer in group AP than in the other two groups. The postoperative correction of kyphosis was significantly greater in group P than in group A. Although the differences were not significant, better outcomes were obtained in group P in: back pain relief at the end point; ambulatory ability at the end point; and average loss of correction.ConclusionsThe posterior closing wedge osteotomy demonstrated better surgical results than the anterior spinal fusion procedure and the single-stage combined anterior-posterior procedure

Tsukuba 32-m VLBI Station

The Tsukuba 32-m VLBI station is operated by the Geospatial Information Authority of Japan. This report summarizes activities of the Tsukuba 32-m VLBI station in 2012. More than 200 sessions were observed with the Tsukuba 32-m and other GSI antennas in accordance with the IVS Master Schedule of 2012. We have started installing the observing facilities that will be fully compliant with VLBI2010 for the first time in Japan

Deadbeat control of power leveling unit with bidirectional buck/boost DC/DC converter

As a distributed generation system increases, a stable power supply becomes difficult. Thus control of power leveling (PL) unit is required to maintain the balance of power flow for irregular power generation. The unit is required to respond to change of voltage and bidirectional power flow. So the bidirectional buck/boost DC/DC converter is applied for the control of PL unit in this research. The PL unit with Electric double-layer capacitor (EDLC) is able to absorb change of power, and it is examined whether the stable power supply is possible. The output current of PL unit is controlled so as to keep power balance and DC bus voltage. The effectiveness of the deadbeat control for power leveling unit is proved in simulation and experiment.7th International Power Electronics Conference, IPEC-Hiroshima - ECCE Asia 2014; Hiroshima; Japan; 18 May 2014 through 21 May 201

Vaginoplasty with a Pudendal-groin Flap in Male-to-female Transsexuals

Many vaginoplasty techniques have been introduced to improve the outcomes of sex reassignment surgery for male-to-female transsexuals. Some vaginoplasty patients still require additional skin grafts, making dilation mandatory to overcome shrinkage. We developed a new vaginoplasty method (called the “pudendal-groin flap”) that uses pudendal-groin flaps. One of this procedure’s advantages is that skin grafts are unnecessary, even for patients with small penises and scrotums. We introduce the procedure here and describe our evaluation of its utility. We retrospectively analyzed the cases of the 15 patients who underwent vaginoplasty using pudendal-groin flaps from May 2010 to January 2016 at our institution. We compared the complications as well as the functional and aesthetic outcomes with those of previous studies. The most common complication was bleeding, which occurred at the corpus spongiosum or while creating a new vaginal cavity. Bleeding can be reduced with more careful hemostasis and dissection. Aside from inadequate vaginal depth in one patient, the incidence of other complications, sexual intercourse, and aesthetic outcomes were acceptable. The pudendal- groin flap is thin and pliable and can create sufficient vaginal depth without skin grafts. The resulting scar is inconspicuous. Our findings suggest that vaginoplasty using the pudendal-groin flap method is feasible

Risk Factors for Postoperative Hematoma after Chest Wall Contouring for Female-to-Male Transsexuals: A Clinical Study

Gender dysphoria is a condition in which a discrepancy between biological sex and gender identity causes distress. Many female-to-male transsexuals (FTMTS) are uncomfortable with female breasts. Chest wall contouring surgery is effective for obtaining a male-type chest, reducing mental stress, and increasing sexual satisfaction in such cases. At the Okayama University Hospital Gender Center, we have obtained positive results using an algorithm to determine the most appropriate surgical method for chest wall contouring in FTMTS patients. However, serious complications requiring reoperation, such as hematoma, may still occur. Postoperative hematomas were found in 15 (4.18%) of 358 FTMTS patients who underwent chest contouring surgery at our hospital between 2006 and 2018. Postoperative hematoma was examined retrospectively. The median time to the onset of hematoma was 7 (6-12) h after the initial surgery. The main blood vessels causing bleeding were those in the head-side skin flap region where visual confirmation was difficult and the perforator vessels from the pectoralis major muscle. Intraoperative bleeding and the operation time had a significant impact on the onset of postoperative hematoma. This is the first retrospective study that investigated the blood vessels and other factors contributing to postoperative hematoma development after chest wall contouring

Impact of Immediate Breast Reconstruction on Survival of Breast Cancer Patients: A Single-Center Observational Study

Although immediate breast reconstruction following mastectomy has become increasingly common, its oncological safety has been debated. We enrolled patients with breast cancer who underwent surgery at Okayama University Hospital between 2007 and 2013. The primary outcome was relapse-free survival (RFS). Secondary outcomes were overall survival and the duration from the surgery to the initiation of adjuvant chemotherapy. We divided into immediate breast reconstruction, mastectomy alone, and breast conservative surgery groups. Outcomes were compared using Cox’s regression analysis. A total of 614 patients were included (reconstruction: 125, mastectomy: 128, breast conservative surgery: 361). The median follow-up duration was 79.0±31.9 months. The immediate-reconstruction patients were younger, had more lymph node metastases, and more often received postoperative chemotherapy. The RFS was better after the breast conservative surgery compared to after reconstruction (hazard ratio 0.33, 95% confidence interval: 0.144-0.763). The proportion of local recurrence was highest in the reconstruction group. No patients in the reconstruction group underwent postoperative radiation therapy. However, reconstruction did not affect overall survival or the time to the initiation of adjuvant chemotherapy. Surgeons should explain the risks of breast reconstruction to their patients preoperatively. Careful long-term follow-up is required after such procedures