20 research outputs found

    Experimental Behavior of L-Shaped and T-Shaped Cross-Laminated Timber to Evaluate Shear Walls with Openings

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    There is increasing interest in using cross-laminated timber (CLT) in buildings because of its high strength and stiffness. In Japan, structural design guidelines for CLT buildings were established in 2016 and construction of mid-rise buildings is increasing. Wide-panel walls can exceed widths of 10 m and integrate cut-outs for window and door openings. However, under lateral loads, corner cracks at the openings have been the most prevalent failure mechanism. To investigate the initiation and propagation of corner cracks, a series of bendings are undertaken on L- and T-shape specimens extracted from the CLT panels. In addition, three-point bending and shear tests are also carried out on beam sections extracted from the CLT panels. Three types of brittle failure were observed: bending failure of the beam or column, and rolling shear failure

    A Case of Cholesterol Crystal Embolization with Hemorrhagic Intestinal Ulcer

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    Cholesterol crystal embolization (CCE) is a rare systemic embolism caused by formation of cholesterol crystals from atherosclerotic plaques. CCE usually occurs during vascular manipulation such as vascular surgery or endovascular catheter manipulation, or due to anticoagulation or thrombolytic therapy. We report a rare case of localized intestinal ulcer with active hemorrhage caused by spontaneous CCE. An 83-year-old man with a history of hypertension and diabetes was treated with a percutaneous coronary intervention (PCI) for myocardial infarction. Melena occurred eight days after PCI. An abdominal computed tomography revealed small intestinal ulcer, extravasation of the gastrointestinal tract and bleeding in the abdominal cavity. The patient was diagnosed as bleeding from the small intestinal ulcer, so an emergency laparotomy was performed. Partial resection of the small intestine was performed. A histopathological examination indicated that small intestine obstruction was caused by CCE. A histopathological examination indicated that small intestinal obstruction was caused by CCE. Therefore, in cases of intestinal obstruction after vascular manipulation, CCE should also be considered

    Evaluation of intra-ductal cancer spread using contrast superb micro-vascular imaging (SMI) : a case report

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    Currently, breast conserving surgery has been adopted to treat more than half of all breast cancer patients in Japan. When performing breast-conserving surgery, an appropriate margin needs to be determined for radical cure. The resection volume influences the esthetic outcome, but a cancer-positive resection stump is also important risk factor of local recurrence. Additionally, the degree of cancer progression influences the surgical method, so understanding the appropriate resection margin is necessary for the surgeons. We report here on a 50- year old patient whose intra-ductal cancer progression was shown, as predicted, by contrast SMI (superb micro-vascular imaging). A one-cm size tumor mass was palpable with a clear boundary. B-mode ultrasound confirmed the presence of a breast duct towards the nipple from the tumor mass. Using contrast SMI, an accelerated blood flow was detected around the duct, which suggested intra-ductal progression. The pathological results also showed intra-ductal progression to the nipple from the tumor. Around the progression area, a meandering vessel was found and the vessel was able to be visualized by contrast SMI

    Influence of the Different Primary Cancers and Different Types of Bone Metastasis on the Lesion-based Artificial Neural Network Value Calculated by a Computer-aided Diagnostic System,BONENAVI, on Bone Scintigraphy Images

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    Objective(s): BONENAVI, a computer-aided diagnostic system, is used in bone scintigraphy. This system provides the artificial neural network (ANN) and bone scan index (BSI) values. ANN is associated with the possibility of bone metastasis, while BSI is related to the amount of bone metastasis. The degree of uptake on bone scintigraphy can be affected by the type of bone metastasis. Therefore, the ANN value provided by BONENAVI may be influenced by the characteristics of bone metastasis. In this study, we aimed to assess the relationship between ANN value and characteristics of bone metastasis. Methods: We analyzed 50 patients (36 males, 14 females; age range: 42–87 yrs, median age: 72.5 yrs) with prostate, breast, or lung cancer who had undergone bone scintigraphy and were diagnosed with bone metastasis (32 cases of prostate cancer, nine cases of breast cancer, and nine cases of lung cancer). Those who had received systematic therapy over the past years were excluded. Bone metastases were diagnosed clinically, and the type of bone metastasis (osteoblastic, mildly osteoblastic,osteolytic, and mixed components) was decided visually by the agreement of two radiologists. We compared the ANN values (case-based and lesion-based) among the three primary cancers and four types of bone metastasis.Results: There was no significant difference in case-based ANN values among prostate, breast, and lung cancers. However, the lesion-based ANN values were the highest in cases with prostate cancer and the lowest in cases of lung cancer (median values: prostate cancer, 0.980; breast cancer, 0.909; and lung cancer, 0.864). Mildly osteoblastic lesions showed significantly lower ANN values than the other three types of bone metastasis (median values: osteoblastic, 0.939; mildly osteoblastic, 0.788; mixed type, 0.991; and osteolytic, 0.969). The possibility of a lesion-based ANN value below 0.5 was 10.9% for bone metastasis in prostate cancer, 12.9% for breast cancer, and 37.2% for lung cancer. The corresponding possibility were 14.7% for osteoblastic metastases, 23.9% for mildly osteoblastic metastases, 7.14% for mixedtype metastases, and 16.0% for osteolytic metastases.Conclusion: The lesion-based ANN values calculated by BONENAVI can be influenced by the type of primary cancer and bone metastasis

    The Efficiency of Respiratory-gated 18F-FDG PET/CT in Lung Adenocarcinoma: Amplitude-gating Versus Phase-gating Methods

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    Objective(s): In positron emission tomography (PET) studies, thoracic movement under free-breathing conditions is a cause of image degradation. Respiratory gating (RG) is commonly used to solve this problem. Two different methods, i.e., phase-gating (PG) and amplitude-gating (AG) PET, are available for respiratory gating. It is important to know the strengths and weaknesses of both methods when selecting an RG methodfor a given patient. We conducted this study to clarify whether AG or PG is preferable for measuring fluorodeoxyglucose (FDG) accumulation in lung adenocarcinoma and to investigate patient conditions which are most suitable for AG and PG methods.Methods: A total of 31 patients (11 males, 20 females; average age: 11.6±70.1 yrs) with 44 lung lesions, diagnosed as lung adenocarcinoma between April 2012 and March 2013, were investigated. Whole-body FDG-PET/CT scan was performed with both PG and AG methods in all patients. The maximum standardized uptake value (SUVmax) of PG, AG, and the control data of these two methods were measured, and the increase ratio (IR), calculated as IR(%)= (Post – Pre)/Pre × 100, was calculated. The diameter and positionof lung lesions were also analyzed. We defined an ‘effective lesion’ of PG (or AG) as a lesion which showed a higher IR compared to AG (or PG). 8 (25.8%)Results: The average SUVmax and average IR were 7.94±8.99 and 25.6±21.4% in PG and 6.70±7.60 and 14.4±4.0% in AG, respectively. Although there was no significant difference between the average SUVmax of PG and AG (P=0.09), the average IR of PG was significantly higher than that of AG (

    Significance of Error-avoiding Mechanisms for Oxidative DNA Damage in Carcinogenesis

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    Oxygen radicals are produced through normal cellular metabolism, and formation of such radicals is further enhanced by ionizing radiation and by various chemicals. Among various classes of oxidative DNA damage, 8-oxo-7,8-dihydroguanine (8-oxoG) is the most abundant, and appears to play important roles in mutagenesis and carcinogenesis. We have focused on following the two enzymes. MTH1 protein hydrolyzes 8-oxo-dGTP to monophosphate in the nucleotide pool, thereby preventing occurrence of transversion mutations. On the other hand, MUTYH protein, having adenine/2-hydroxyadenine DNA glycosylase activity, is expected to prevent G:C to T:A transversions, by excising adenine from G:A mismatches induced by 8-oxoG and 2-OH-A. To analyze the function of the mammalian MTH1 and MUTYH proteins in vivo, we established gene-knockout mice for these two enzymes, and investigated spontaneous tumorigenesis as well as mutagenesis
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