1,498 research outputs found

    Subcutaneous Sacrococcygeal Myxopapillary Ependymoma in Asian Female:A Case Report

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    Subcutaneous sacrococcygeal myxopapillary ependymoma is extremely rare tumor that has a tendency to develop in children and adolescents. There have been several case reports and sporadic reports in the literature. However, no case has been reported in an Asian patient, to the best of our knowledge. We describe a 25-year-old Asian female patient with a subcutaneous sacrococcygeal myxopapillary ependymoma that had been clinically diagnosed as a pilonidal cyst. The tumor was treated successfully by surgical excision and the patient is doing well without evidence of local recurrence or distant metastasis at 2 years after surgery.

    Deterministic creation and deletion of a single magnetic skyrmion observed by direct time-resolved X-ray microscopy

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    Spintronic devices based on magnetic skyrmions are a promising candidate for next-generation memory applications due to their nanometre-size, topologically-protected stability and efficient current-driven dynamics. Since the recent discovery of room-temperature magnetic skyrmions, there have been reports of current-driven skyrmion displacement on magnetic tracks and demonstrations of current pulse-driven skyrmion generation. However, the controlled annihilation of a single skyrmion at room temperature has remained elusive. Here we demonstrate the deterministic writing and deleting of single isolated skyrmions at room temperature in ferrimagnetic GdFeCo films with a device-compatible stripline geometry. The process is driven by the application of current pulses, which induce spin-orbit torques, and is directly observed using a time resolved nanoscale X-ray imaging technique. We provide a current-pulse profile for the efficient and deterministic writing and deleting process. Using micromagnetic simulations, we also reveal the microscopic mechanism of the topological fluctuations that occur during this process.Comment: 27 pages, 4 figure

    A Case of Suspected Isotretinoin-Induced Malformation in a Baby of a Mother Who Became Pregnant One Month after Discontinuation of the Drug

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    Isotretinoin is a known human teratogen that can cause multiple malformations. At present, women who conceive one cycle after discontinuing isotretinoin are told that their teratogenic risk is not higher than baseline. We present a case of both ear malformation in a newborn whose mother had taken isotretinoin for 2 years until one month prior to the time when she became pregnant. We suggest that further studies of pharmacokinetics and malformation of isotreinoin are needed

    Association between Choroidal Thickness and Ocular Perfusion Pressure in Young, Healthy Subjects: Enhanced Depth Imaging Optical Coherence Tomography Study

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    PURPOSE. To investigate the correlation of choroidal thickness (CT) with ocular perfusion pressure (OPP) in young, healthy subjects using enhanced depth imaging optical coherence tomography (EDI-OCT). METHODS. A single horizontal section and a single vertical section of EDI-OCT scans in each eye of 69 young, healthy subjects were obtained at the macula. CT was measured at the fovea, and up to 3 mm, at intervals of 0.5 mm, away from the fovea in the superior, inferior, nasal, and temporal choroid. Univariable and multivariable analyses were performed to assess the association of CT with OPP while axial length (AL), refractive error (RE), sex, and/or body mass index (BMI), were taken into consideration. RESULTS. Mean subfoveal CT was 307.03 6 91.27 lm (mean age, 22.3 6 3 years; mean axial length, 25.35 6 1.14 mm; mean refractive error, À3.89 6 2.02 diopters; mean OPP, 44.18 6 5.49 mm Hg). Multivariable regression analysis showed that in eyes with <6 diopters of myopia, subfoveal CT (325.92 6 88.46 lm) changed most significantly in association with RE and mean OPP (b ¼ 25.941, P < 0.001; b ¼À3.551, P ¼ 0.042, respectively; adjusted R 2 ¼ 0.249). In subjects with myopia of >6 diopters, subfoveal CT (225.17 6 49.37 lm) was significantly thinner (P < 0.0001), and a significant correlation with OPP was not observed (P > 0.05). CONCLUSIONS. In vivo subfoveal CT as measured by EDI-OCT was significantly associated with OPP in young, healthy subjects when adjusted for RE, suggesting that subfoveal CT may be indirectly indicative of subfoveal ocular perfusion status. This association was not observed in subjects with high myopia. (Invest Ophthalmol Vis Sci. 2012;53:7710-7717

    Bilateral adrenal pheochromocytoma with a germline L790F mutation in the RET oncogene

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    About ten percent of pheochromocytomas are associated with familial syndrome. Hereditary pheochromocytoma has characteristics of early onset, multifocality and bilaterality. We experienced a case of 44-year-old man with bilateral pheochromocytoma without evidence of medullary thyroid cancer. Genetic test detected a L790F germline mutation of RET oncogene. The author found a necessity for genetic tests in cases of young-age, bilateral pheochromocytoma

    3D and 4D Printing of Multistable Structures

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    Three-dimensional (3D) printing is a new paradigm in customized manufacturing and allows the fabrication of complex structures that are difficult to realize with other conventional methods. Four-dimensional (4D) printing adds active, responsive functions to 3D-printed components, which can respond to various environmental stimuli. This review introduces recent ideas in 3D and 4D printing of mechanical multistable structures. Three-dimensional printing of multistable structures can enable highly reconfigurable components, which can bring many new breakthroughs to 3D printing. By adopting smart materials in multistable structures, more advanced functionalities and enhanced controllability can also be obtained in 4D printing. This could be useful for various smart and programmable actuators. In this review, we first introduce three representative approaches for 3D printing of multistable structures: strained layers, compliant mechanisms, and mechanical metamaterials. Then, we discuss 4D printing of multistable structures that can help overcome the limitation of conventional 4D printing research. Lastly, we conclude with future prospects
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