42 research outputs found

    Observation of Allende and Antarctic meteorites by monochromatic X-ray CT based on synchrotron radiation

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    Three-dimensional CT images of the Allende meteorite with a high resolution of 10μm have been obtained nondestructively by a monochromatic X-ray computed tomography (CT) based on synchrotron radiation (SR). The metallic minerals, matrix and chondrules can be clearly observed in the CT images. The CT values, which express the image intensity, allow a quantitative elemental analysis including such as difference in the metallic minerals, i. e., pentlandite and troilite, using the comparison of CT images and elemental images measured by a computer-aided microanalyzer (CMA). The three-dimensional CT images indicate that the metallic minerals surround some chondrules, and the largest chondrule has two humps and well crystallized olivine in its center. These observations suggest that the three-dimensional SR-CT system is a useful method for identification of internal structures of stony meteorites. Additionally, information obtained from the CT images of Antarctic meteorites confirms that the SR-CT system can be applied to classification of stony chondrites

    Thoracoscopic Surgery in a Patient with Multiple Esophageal Carcinomas after Surgery for Esophageal Achalasia

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    We present a case in which we used a thoracoscopic approach for resection of multiple esophageal carcinomas diagnosed 33 years after surgery for esophageal achalasia. A 68-year-old Japanese man had been diagnosed with esophageal achalasia and underwent surgical treatment 33 years earlier. He was examined at our hospital for annual routine checkup in which upper gastrointestinal endoscopy showed a “0-IIb+IIa” lesion in the middle esophagus. Iodine staining revealed multiple irregularly shaped iodine-unstained areas, the diagnosis of which was esophageal carcinoma. Thoracoscopic subtotal esophagectomy was performed. Esophageal carcinoma may occur many years after surgery for esophageal achalasia, even if the passage symptoms have improved. So, long-term periodic follow-up is necessary for detection of carcinoma at an earlier stage

    Perforation of intramural gastric metastasis during preoperative chemotherapy in a patient with thoracic esophageal squamous cell carcinoma

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    AbstractIntroductionPerforation of intramural metastasis to the stomach (IMS) from esophageal cancer during chemotherapy has not been reported.Presentation of caseA 68-year-old male consulted our hospital due to appetite loss. He was diagnosed with advanced esophageal squamous cell carcinoma in the lower thoracic esophagus along with a large IMS in the upper stomach. The patient received preoperative chemotherapy of docetaxel, cisplatin, and 5-fluorouracil (DCF). During the second cycle of DCF, he had upper abdominal pain and was diagnosed with gastric perforation. Omental implantation repair for the perforation, peritoneal drainage, tube-gastrostomy, and tube-jejunostomy were performed.At 24 days after emergency surgery, he underwent thoracoscopic radical esophagectomy with total gastrectomy and reconstruction with colonic interposition. Pathological findings in the esophagus demonstrated complete replacement of the tumor by fibrosis. The gastric tumor was replaced by scar tissue with multinucleated giant cells along with a small amount of viable cancer cells. The patient was alive and healthy at 14 months after the radical operation, without tumor recurrence.DiscussionThe gastric perforation occurred due to rapid regression of the IMS which had involved the whole gastric wall before chemotherapy. Close monitoring to detect rapid tumor shrinkage during chemotherapy in patients with IMS may be warranted. A two-step operation was proposed to achieve safe curative treatment in patients with perforation of IMS during preoperative chemotherapy.ConclusionWe describe the first reported case of a patient with esophageal squamous cell carcinoma who showed perforation of IMS during preoperative chemotherapy

    Decline in Left Ventricular Ejection Fraction during Follow-up in Patients with Severe Aortic Stenosis

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    Objectives: The aim of this study was to investigate the prognostic impact of the decline in left ventricular ejection fraction (LVEF) at 1-year follow-up in patients with severe aortic stenosis (AS) managed conservatively. Background: No previous study has explored the association between LVEF decline during follow-up and clinical outcomes in patients with severe AS. Methods: Among 3, 815 patients with severe AS enrolled in the multicenter CURRENT AS (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis) registry in Japan, 839 conservatively managed patients who underwent echocardiography at 1-year follow-up were analyzed. The primary outcome measure was a composite of AS-related deaths and hospitalization for heart failure. Results: There were 91 patients (10.8%) with >10% declines in LVEF and 748 patients (89.2%) without declines. Left ventricular dimensions and the prevalence of valve regurgitation and atrial fibrillation or flutter significantly increased in the group with declines in LVEF. The cumulative 3-year incidence of the primary outcome measure was significantly higher in the group with declines in LVEF than in the group with no decline (39.5% vs. 26.5%; p 10% declines in LVEF at 1 year after diagnosis had worse AS-related clinical outcomes than those without declines in LVEF under conservative management. (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis Registry; UMIN000012140

    Initial Surgical Versus Conservative Strategies in Patients With Asymptomatic Severe Aortic Stenosis

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    AbstractBackgroundCurrent guidelines generally recommend watchful waiting until symptoms emerge for aortic valve replacement (AVR) in asymptomatic patients with severe aortic stenosis (AS).ObjectivesThe study sought to compare the long-term outcomes of initial AVR versus conservative strategies following the diagnosis of asymptomatic severe AS.MethodsWe used data from a large multicenter registry enrolling 3,815 consecutive patients with severe AS (peak aortic jet velocity >4.0 m/s, or mean aortic pressure gradient >40 mm Hg, or aortic valve area <1.0 cm2) between January 2003 and December 2011. Among 1,808 asymptomatic patients, the initial AVR and conservative strategies were chosen in 291 patients, and 1,517 patients, respectively. Median follow-up was 1,361 days with 90% follow-up rate at 2 years. The propensity score–matched cohort of 582 patients (n = 291 in each group) was developed as the main analysis set for the current report.ResultsBaseline characteristics of the propensity score–matched cohort were largely comparable, except for the slightly younger age and the greater AS severity in the initial AVR group. In the conservative group, AVR was performed in 41% of patients during follow-up. The cumulative 5-year incidences of all-cause death and heart failure hospitalization were significantly lower in the initial AVR group than in the conservative group (15.4% vs. 26.4%, p = 0.009; 3.8% vs. 19.9%, p < 0.001, respectively).ConclusionsThe long-term outcome of asymptomatic patients with severe AS was dismal when managed conservatively in this real-world analysis and might be substantially improved by an initial AVR strategy. (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis Registry; UMIN000012140

    A Study of The Plant Type of Barnyardgrass II. Divergence of hill spread in mixed planting

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