89 research outputs found

    Thermoluminescence studies of ordinary chondrites in the Japanese Antarctic meteorite collection, III: Asuka and Yamato type 3

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    We measured thermoluminescence (TL) properties of 37 Asuka and 13 Yamato type 3 ordinary chondrites from Japanese Antarctic meteorite collection for determining subtypes and pairing. Most of the meteorites are of petrologic type 3.6-3.9; however, we found three primitive ordinary chondrites (A-9043,A-87319 and Y-793384) of petrologic type ≦3.1. We found 22 TL potential pairing groups in 26 Asuka H3 chondrites comprising a chain of pairing groups, which implies an H3 chondrite shower near the Asuka area

    Thermoluminescence studies of ordinary chondrites in the Japanese Antarctic meteorite collection, II: New measurements for thirty type 3 ordinary chondrites

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    We have measured the thermoluminescence (TL) properties of thirty type 3 ordinary chondrites from the Japanese Antarctic meteorite collection. This brings to 73 the total number of Japanese type 3 ordinary chondrites examined in this way by the Arkansas-Okayama collaboration. Fifteen pairing groups were found using TL and geographical criteria. Most of the new meteorites are of petrologic types 3.6-3.9,but fourteen are of petrologic type ≤3.4. Six of the 73 meteorites (Yamato (Y)-790448,Y-793596,Y-793565,Y-791324,Y-791558,Y-74660) have petrographic types 3.5) tend to have higher induced TL peak temperature and peak width than those with low TL sensitivity, in confirmation of earlier work and consistent with peak temperature and width as well as TL sensitivity, being independent parameters of thermal history. Samples not obeying these trends (Y-75029,Y-86706,Y-793567 and Y-790787), are either heavily weathered or experienced atypical thermal histories

    Synthesis of tertiary alkylphosphonate oligonucleotides through light-driven radical-polar crossover reactions

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    光エネルギーで新しい化学修飾核酸を合成 --核酸リン原子の第三級アルキル化に成功--. 京都大学プレスリリース. 2023-11-01.Chemical modification of nucleotides can improve the metabolic stability and target specificity of oligonucleotide therapeutics, and alkylphosphonates have been employed as charge-neutral replacements for naturally-occurring phosphodiester backbones in these compounds. However, at present, the alkyl moieties that can be attached to phosphorus atoms in these compounds are limited to methyl groups or primary/secondary alkyls, and such alkylphosphonate moieties can degrade during oligonucleotide synthesis. The present work demonstrates the tertiary alkylation of the phosphorus atoms of phosphites bearing two 2’-deoxynuclosides. This process utilizes a carbocation generated via a light-driven radical-polar crossover mechanism. This protocol provides tertiary alkylphosphonate structures that are difficult to synthesize using existing methods. The conversion of these species to oligonucleotides having charge-neutral alkylphosphonate linkages through a phosphoramidite-based approach was also confirmed in this study

    Mid- term results of stryker® scorpio plus mobile bearing total knee arthroplasty

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    BACKGROUND: The mobile bearing knee system was introduced to lessen contact stress on the articular bearing surface and reduce polyethylene wear. The purpose of the current study was to investigate the mid-term results of patients undergoing total knee arthroplasties (TKAs) using Scorpio Plus Mobile Bearing Knee System (Stryker, Mahwah, NJ), and compare the outcomes between patients with osteoarthritis and osteonecrosis (OA·ON group) and patients with rheumatoid arthritis (RA group). METHODS: Eight males and 58 females were followed up for a period of 4.4- 7.6 years from June 1, 2003 to December 31, 2005. There were 53 knees with osteoarthritis, 17 knees with rheumatoid arthritis, and 6 knees with osteonecrosis. Clinical and radiographic follow- up was done using The Japanese Orthopedic Association knee rating score (JOA score) and Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System. RESULTS: With regard to the JOA score, there was significant improvement in both groups. The postoperative range of motion was between 0.8°and 116.8° in OA·ON group, and between 0.0° and 113.7° in RA group. There were no significant differences with the radiographic evaluation between two groups. Spontaneous dislocation of a polyethylene insert occurred in one patient, and deep infection was occurred in one patient. CONCLUSION: There was significant improvement with regard to the clinical and radiographic results of patients undergoing TKAs using the model. The risk of polyethylene insert dislocation related to the mobile bearing TKA is a cause for concern

    Multiacquisition Variable-Resonance Image Combination Selective Can Improve Image Quality and Reproducibility for Metallic Implants in the Lumbar Spine

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    The aim of this study is to evaluate how metallic artifacts in the lumbar spine can affect images obtained from magnetic resonance (MR) sequences. We performed a phantom experiment by scanning an agar containing an orthopedic metallic implant using 64-channel multidetector row computed tomography (CT) and a 3-tesla MR unit. We compared the reproducibility in each measurement, enlargement or reduction ratio of the CT and MR measurements, and signal deviation in each voxel from the control. The reproducibility on CT and multiacquisition variable-resonance image combination selective (MAVRIC SL) was good, but that on the other MR sequences showed either fixed bias or proportional bias. The reduction ratios of the distance between the nails were significantly smaller in MAVRIC SL than in the other MR sequences after CT measurements (p<0.001, respectively). MAVRIC SL was able to reduce the metallic artifact, permitting observation of the tissue surrounding the metal with good reproducibility

    Muscle-specific deletion of BDK amplifies loss of myofibrillar protein during protein undernutrition

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    Ishikawa, T., Kitaura, Y., Kadota, Y. et al. Muscle-specific deletion of BDK amplifies loss of myofibrillar protein during protein undernutrition. Sci Rep 7, 39825 (2017). https://doi.org/10.1038/srep3982

    ゲンダイ キョウイク ニンゲンロン ニオケル カタリ : 「キョウイク ト ニンゲン」 タンキュウ ノ タビ

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    The main queries in the class Discussion on the Current Education and Humanity are ‘What is humanity?’ and ‘What is education?’ Definite answers to these questions are not expected from the onset. Accordingly, four lecturers explore these themes from different viewpoints, similar to the metaphor of four visually impaired people trying to identify an elephant. This paper presents the findings of the four lecturers ; the observations they compiled while ‘touching’ the elephant−like questions, guided by their own individual research interests and knowledge. The response to the class varied, from criticism that the goals of the lesson appeared too vague or confusing, to positive comments about the opportunity to explore concepts more deeply and the uniqueness of the class. In the lecture of the 2013 academic year, Chikamori talked about support from the anthropological viewpoint, quoting findings from several different research fields. Tanimura shed light on the contrasting difference in the way of looking at children between E.H. Erikson and E. Lévinas. Ota discussed the possibility of development under the adverse conditions which humans face referring to the deconstruction of J. Derrida. Then Hirose introduced the practice of “Steiner Education” and discussed the possibility of application of it in Japanese primary schools based on the views of humanity and education according to R. Steiner. This paper is like an itinerary describing not only the narratives during our journey to explore “Education and Humanity”, but also providing evidence of something tangible which emerged within the individual travelers. It is our hope that answers of one form or another to the questions ; ‘What is education?’ and ‘What is humanity?’ might begin to appear in the process of reading and reflecting on this itinerary

    Malignant transformation arising from mature cystic teratoma of the ovary presenting as ovarian torsion: a case report and literature review

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    Objective: Ovarian torsion is an acute gynecological condition. Torsion is more likely to occur with benign rather than malignant tumors. Mature cystic teratoma of the ovary (MCTO) is frequent in women of reproductive age; however, the incidence of malignant transformation is approximately 2%. We report a case of malignant transformation of MCTO presenting as ovarian tumor torsion. Case report: A 51-year-old premenopausal woman was diagnosed with mature cystic teratoma in the left ovary 7 years ago. The patient visited our hospital because she had been experiencing of pain in left lower abdomen for the past two days. She was diagnosed with ovarian tumor torsion and underwent emergency surgery. The left ovarian tumor was twisted, and left salpingo-oophorectomy was performed. Histopathological examination revealed squamous cell carcinoma arising from the MCTO. We carefully followed the patients without performing staging laparotomy. On postoperative day 112, multiple lymph node metastases in the pelvic and para-aortic areas were found by positron-emission tomography and computed tomography. After referral to a university hospital, total hysterectomy, right salpingo-oophorectomy, partial omentectomy, and pelvic and paraaortic lymphadenectomy were performed. Metastases of squamous cell carcinoma were confirmed in the pelvic and para-aortic lymph nodes. Six courses of adjuvant chemotherapy with paclitaxel and carboplatin were given following radical surgery to prevent the recurrence of malignant transformation of MCTO. No recurrence of the disease has been observed during 2 years of follow-up. Conclusio: When physicians diagnose large ovarian tumor torsion cases, preoperative examinations should be performed, with the possibility of malignancy in mind
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