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The mechanical properties of a quasi-isotropic carbon fiber reinforced plastic (CFRP) laminate with a punched hole were investigated. During the punching process, pressure was applied to the laminate through the upper and lower blank holders of a punching machine; the clearance between the punch and blank holders was set to be small to suppress damage in the CFRP laminates. Due to the dragging of plies encountered during punching, the surface of the punched hole was relatively uneven as compared to that of the drilled hole. However, the effect of the uneven surface created during the punching process was not as significant on the tensile and compressive strength of the open hole as compared to the manufacturing damages generated by drilling processes. The stress-number of cycles to failure curves for the open-hole tension-tension fatigue tests also showed comparable results between the punched- and drilled-hole specimens. These results indicate that there were no significant differences in the mechanical properties of CFRP laminates with a punched hole, and thus present the possibility of a highly productive hole-making process using the punching method., Competing Interests: The authors declare no conflict of interest., (© 2020 The Author(s).)

A 67-year-old female was operated upon because of transthoracic echocardiograms revealing a 13 x 8 mm mass in right atrium. However, there was no mass and was prominent crista terminalis (CT) instead. CT is the largest and strongest fibromuscular bundle in the right atrium, which separates primitive right atrium from the venous sinus. Prominent CT can mimic right atrial mass on transthoracic echocardiography. It was difficult to make a differential diagnosis because prominent CT formed a bridge-like shape in this case. To obtain certain diagnosis, transesophageal echocardiography (TEE) is necessary, and prevalence of three-dimensional (3D)-TEE is expected to improve the accuracy of diagnosis. We report this case as a pitfall of the diagnosis for the right atrial mass.

The salamander Hynobius yatsui from southwestern Japan was formerly regarded as a small-sized group of H. naevius, but has recently been resurrected as a distinct species. We investigated the phylogeography of H. yatsui from Kyushu Island using partial sequences of the mitochondrial cytochrome b gene. We detected 49 haplotypes in 181 individuals from 24 localities covering the entire geographic distribution of this species on Kyushu. These haplotypes were grouped into two lineages, a northern lineage from northern and central regions, and a southern lineage from the southern region; no haplotypes were shared between the lineages. We surmise that the divergence of the two lineages was induced by volcanic activity that started in the Beppu-Shimabara Graben, between the areas occupied by these two lineages. From the results of a nested clade phylogeographical analysis, we surmise that the high intrapopulation genetic variation observed in the non-volcanic Kyushu Mountains was generated by alternation of contiguous range expansion or long-distance dispersal, and isolation. The current distribution and the observed complicated genetic structures of H. yatsui in Kyushu seem to have been affected first by volcanic activities since the late Pliocene, but subsequent climatic oscillations during the Pleistocene may also have some effects, although it is impossible at this time to differentiate the effects of these two factors.

We report the case of a 49-year-old woman with a large organized tricuspid valve thrombus in a structurally normal heart. Preoperative echocardiogram showed a large irregular-shaped mass, approximately 5 cm in diameter, moving from the right atrium into the right ventricle. The assumed preoperative diagnosis was cardiac metastasis of uterine sarcoma because she had undergone surgery for uterine sarcoma 15 years earlier. However, histologic examination revealed an organized thrombus without tumor components.

We report on a 51-year-old Japanese female with bilateral coronary artery aneurysms. Severe calcified aneurysms were detected in the proximal right coronary artery (RCA) and left anterior descending branch (LAD). The RCA was totally occluded and supplied by the blood flow via septal branches of the LAD. A two-stage management plan, including an off-pump coronary artery bypass grafting for the RCA with a right gastroepiploic artery and catheter angioplasty with an autologous vein graft-coated stent for the LAD, was successfully completed. Prophylactic treatments for coronary artery aneurysm are still controversial, therefore, minimal invasive procedures should be favored to prevent acute cardiac shock or sudden death related to aneurysmal obstruction.

A 75-year-old woman admitted for an abnormal chest X-ray shadow was found in transbronchial lung biopsy to have malignant cells. After right lower lobectomy with mediastinal lymph node dissection, pathological examination showed primary pulmonary squamous cell carcinoma (pT2N1M0, stage IIB). After discharge, we followed her up as an outpatient, with oral administration of uracil and futrafur (300 mg/day). Five months postoperatively, a subcutaneous mass detected on her back and surgically removed was found histologically to be metastatic squamous cell carcinoma of subcutaneous tissue from lung cancer. No other metastases were found. The patient has survived 3 years and 3 months since primary surgery and remained cancer-free 2 years and 11 months since resection for skin metastasis. Given that skin metastasis is detected when most patients are in an advanced stage of disease, our case was a rare one of solitary skin metastasis after resection for lung cancer.

A 72-year-old man was found to have an endobronchial lipoma accompanied with primary lung cancer. A left lower lobectomy with a mediastinal lymph node dissection and a sleeve resection of the lingual bronchus with telescoping bronchial anastomosis were done. The pathological staging was T1N2M0, stage IIIA. A histological examination showed well-differentiated squamous cell carcinoma in segment 10, in addition to the presence of mature adipose tissue which was diagnosed to be a benign endobronchial lipoma originating from the lingual bronchus. The postoperative course was uneventful and the patient was discharged 13 days after the operation. However, he had a recurrence in the subcarinal lymph node, and died 8 months after surgery.