120 research outputs found

    Aaptamine-related alkaloid from the marine sponge Aaptos aaptos

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    A new aaptamine-related alkaloid, 1,3-dioxolo [4,5-d] benzo [de]-1,6-naphthyridine (methylenedioxyaaptamine, 1), was isolated from the organic extracts of the Bornean marine sponge Aaptos aaptos, together with a known aaptamine derivative, 8,9,9-trimethoxy-9H-benzo [de]-1,6-naphthyridine (2). The structure of compound 1 was elucidated by interpretation of its spectroscopic data. Two compounds were tested for their cytotoxic potentials against adult T-cell leukemia (ATL) cells, and compound 1 showed moderate cytotoxic potential

    モールドレス成形によるチタン多孔体の補綴装置への応用 : 物理的および機械的性質における粉末粒径、形状と混合比率が及ぼす影響

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    The prosthetic applications of titanium have been challenging because titanium does not possess suitable properties for the conventional casting method using the lost wax technique. We have developed a production method for biomedical application of porous titanium using a moldless process. This study aimed to evaluate the physical and mechanical properties of porous titanium using various particle sizes, shapes, and mixing ratio of titanium powder to wax binder for use in prosthesis production. CP Ti powders with different particle sizes, shapes, and mixing ratios were divided into five groups. A 90:10 wt% mixture of titanium powder and wax binder was prepared manually at 70℃. After debinding at 380℃, the specimen was sintered in Ar at 1100℃ without a mold for 1h. The linear shrinkage ratio of sintered specimens ranged from 2.5% to 14.2%. The linear shrinkage ratio increased with decreasing particle size. While the linear shrinkage ratio of Groups 3, 4, and 5 were approximately 2%, Group 1 showed the highest shrinkage of all. The bending strength ranged from 106 to 428 MPa under the influence of porosity. Group 1 and 2 presented low porosity followed by higher strength. The shear bond strength ranged from 32 to 100 MPa. The shear bond strength was also particle-size dependent. The decrease in the porosity increased the linear shrinkage ratio and bending strength. Shrinkage and mechanical strength required for prostheses were dependent on the particle size and shape of titanium powders. These findings suggested that this production method can be applied to the prosthetic framework by selecting the material design

    Spontaneous regression of mediastinal seminoma

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    A 27-year-old man was transferred to our hospital with the complaint of facial edema and diagnosis of giant anterior mediastinal tumor. But soon after admission, the size of the tumor decreased remarkably, although he had no particular treatment. As the tumor was not completely regressed, surgical resection was performed subsequently, and examination of the specimen showed small foci of seminoma within the area of dense fibrous scar tissue, originated from the thymus. While regression of germ cell tumors are well recognized in cases of nonseminomatous germ cell tumors, this phenomenon of primary mediastinal seminoma was not reported previously

    Study protocol for a multi-center, randomized controlled trial to develop Japanese denture adhesive guidelines for patients with complete dentures : the Denture Adhesive Guideline trial : study protocol for a randomized controlled trial

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    Background: Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. However, many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. The aim of this study is to verify the efficacy of denture adhesives to establish guidelines for Japanese users. The null hypothesis is that the application of denture adhesives, including the cream and powder types, or a control (isotonic sodium chloride solution) would not produce different outcomes nor would they differentially improve the set outcomes between baseline and day 4 post-application. Methods: This ten-center, randomized controlled trial with parallel groups is ongoing. Three hundred edentulous patients with complete dentures will be allocated to three groups (cream-type adhesive, powder-type adhesive, and control groups). The participants will wear their dentures with the denture adhesive for 4 days, including during eight meals (three breakfasts, two lunches, and three dinners). The baseline measurements and final measurements for the denture adhesives will be performed on the first day and after breakfast on the fourth day. The primary outcome is a general satisfaction rating for the denture. The secondary outcomes are denture satisfaction ratings for various denture functions, occlusal bite force, resistance to dislodgement, masticatory performance, perceived chewing ability, and oral health-related quality of life. Between-subjects comparisons among the three groups and within-subjects comparisons of the pre- and post-intervention measurements will be performed. Furthermore, a multiple regression analysis will be performed. The main analyses will be based on the intention-to-treat principle. A sample size of 100 subjects per group, including an assumed dropout rate of 10 %, will be required to achieve 80 % power with a 5 % alpha level. Discussion: This randomized clinical trial will provide information about denture adhesives to complete denture wearers, prosthodontic educators, and dentists in Japan. We believe this new evidence on denture adhesive use from Japan will aid dentists in their daily practice even in other countries

    Recent Results from LHD Experiment with Emphasis on Relation to Theory from Experimentalist’s View

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    he Large Helical Device (LHD) has been extending an operational regime of net-current free plasmas towardsthe fusion relevant condition with taking advantage of a net current-free heliotron concept and employing a superconducting coil system. Heating capability has exceeded 10 MW and the central ion and electron temperatureshave reached 7 and 10 keV, respectively. The maximum value of β and pulse length have been extended to 3.2% and 150 s, respectively. Many encouraging physical findings have been obtained. Topics from recent experiments, which should be emphasized from the aspect of theoretical approaches, are reviewed. Those are (1) Prominent features in the inward shifted configuration, i.e., mitigation of an ideal interchange mode in the configuration with magnetic hill, and confinement improvement due to suppression of both anomalous and neoclassical transport, (2) Demonstration ofbifurcation of radial electric field and associated formation of an internal transport barrier, and (3) Dynamics of magnetic islands and clarification of the role of separatrix

    日本睡眠歯科学会口腔内装置診療ガイドライン作成委員会の活動報告

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    Oral appliance therapy was approved by national health insurance in Japan in 2004 and oral appliances(OAs)have since been widely used in the treatment of obstructive sleep apnea(OSA). We herein described the process of making clinical practice guidelines by the task force of the Japanese Academy of Dental Sleep Medicine as a work report. In Japan, OAs are covered by national health insurance. In consideration of the balance between medical treatment fees and the price of technical materials, we used a single-piece(monoblock)OA that advanced the mandible forward and limited mouth opening in OSA patients in Japan. The Japanese Academy of Dental Sleep Medicine(JADSM)focused on OAs frequently used for the treatment of OSA in Japan, and considered an evaluation of their effects to benecessary. Clinical practice guidelines were developed using the Grading of Recommendations, Assessment, Development, and Evaluation(GRADE)system. We recommend OAs that advanced the mandible forward and limited mouth opening for patients with OSA.However, CPAP should be used by patients for whom it has been indicated. OAs are desirable for those who cannot use CPAP(GRADE 1B, strong recommendation/quality of evidence, “Moderate quality”). The long-term effects and side effects, OSA severity, and comorbidities of OA therapy were not examined, which represented a limitation to the present study. In future studies, the Japanese Academy of Dental Sleep Medicine plan to update clinical practice guidelines for oral appliances used in OSA
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