Cosmic R-string, R-tube and Vacuum Instability

We show that a cosmic string associated with spontaneous $U(1)_R$ symmetry breaking gives a constraint for supersymmetric model building. In some models, the string can be viewed as a tube-like domain wall with a winding number interpolating a false vacuum and a true vacuum. Such string causes inhomogeneous decay of the false vacuum to the true vacuum via rapid expansion of the radius of the tube and hence its formation would be inconsistent with the present Universe. However, we demonstrate that there exist metastable solutions which do not expand rapidly. Furthermore, when the true vacua are degenerate, the structure inside the tube becomes involved. As an example, we show a "bamboo"-like solution, which suggests a possibility observing an information of true vacua from outside of the tube through the shape and the tension of the tube.Comment: 28 pages, 17 figures, v2: references added, improved arguments in sec 3.5.

Prediction and Treatment of Difficult Cases in Colorectal Endoscopic Submucosal Dissection

Purpose. The aim of this study was to examine the characteristics of difficult cases and the learning curve in colorectal endoscopic submucosal dissection (ESD). Methods. We studied 518 colorectal tumors treated by ESD. Patients were divided into 2 groups such as the difficult ESD group and non-difficult ESD group in view of procedure time and procedure speed, respectively. The clinical features in each group were analyzed, and we also examined cases with severe fibrosis. Furthermore, we divided all cases into 5 periods according to experience of ESDs and investigated the rates of difficult and perforation cases. Results. In view of both procedure time and procedure speed, there were significant differences about mean tumor size, rates of severe fibrosis and perforation, and en bloc resection rate between the two groups. Severe fibrosis was detected in protruding tumors >40 mm in diameter. With respect to the learning curve, the rate of difficult and perforation cases decreased significantly in the late periods compared to the first period. Conclusions. Large tumor size, high rates of severe fibrosis and perforation, and low rate of en bloc resection are related with difficult ESD cases. The increasing of experiences can decrease the rate of difficult cases and perforation

Antiatherosclerotic phenotype of perivascular adipose tissue surrounding the saphenous vein in coronary artery bypass grafting

冠動脈バイパス術（CABG）で大伏在静脈（SV）グラフトの血管周囲脂肪組織（PVAT）を温存したまま使用するNo-touch法が良好な成績を収め注目されている．本研究では術中に各種PVATを採取して組織性状と遺伝子発現を比較検討した．SV-PVATは冠動脈や大動脈のPVATに比してM1マクロファージの浸潤や炎症性サイトカイン発現が低く，No-touch法の成績向上に寄与している可能性が示唆された