541 research outputs found

    A novel 1-D periodic defected ground structure for planar circuits

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    Pottery use by early Holocene hunter-gatherers of the Korean peninsula closely linked with the exploitation of marine resources

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    The earliest pottery on the Korean peninsula dates to the early Holocene, notably later than other regions of East Asia, such as Japan, the Russian Far East and Southern China. To shed light on the function of such early Korean pottery and to understand the motivations for its adoption, organic residue analysis was conducted on pottery sherds and adhered surface deposit on the wall of pottery vessels (foodcrusts) excavated from the Sejuk shell midden (7.7–6.8ka calBP) on the southeastern coast and the Jukbyeon-ri site (7.9–6.9ka calBP) on the eastern coast of the Korean peninsula, that represents the earliest pottery assemblages with reliable radiocarbon dates. Through chemical and isotopic residue analysis, we conclude that the use of pottery at these sites was oriented towards marine resources, supported by lipid biomarkers typical of aquatic organisms and stable carbon isotope values that matched authentic marine reference fats. The findings contrast with other archaeological evidence, which shows that a wider range of available food resources were exploited. Therefore, we conclude pottery was used selectively for processing aquatic organisms perhaps including the rendering of aquatic oils for storage. Early pottery use in Korea is broadly similar to other prehistoric temperate hunter-gatherers, such as in Japan, northern Europe and northern America. However, it is also notable that elaborately decorated red burnished pottery excavated from isolated location at the Jukbyeon-ri site had a different usage pattern, which indicates that division of pottery use by vessel form was established even at this early stage

    Argon Laser Photoablation for Postburn Conjunctival Pigmentation

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    We report a case of an ocular burn injury from boiling water which resulted in conjunctival pigmentation, 1 week following injury. For cosmetic purposes, 2 sessions of argon laser photoablation were performed. One month after laser treatment, conjunctival pigmentation had been successfully removed and the patient was very satisfied with the results. Argon laser photoablation may be an effective way to remove postburn conjunctival pigmentation

    Successful Treatment of Pure Red Cell Aplasia with Rituximab in Patients after ABO-Compatible Allogeneic Hematopoietic Stem Cell Transplantation

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    Pure red cell aplasia (PRCA) following allogeneic hematopoietic stem cell transplantation (HSCT) has been mostly reported in situations involving major ABO incompatibility between donor and recipient. Conventional treatments such as plasma exchange, erythropoietin, and steroid are often unsatisfactory. Rituximab has been reported to be highly effective for PRCA following major ABO-incompatible allogeneic HSCT. A 49-year-old woman with PRCA following ABO-matched allogeneic HSCT for acute lymphoblastic leukemia, refractory to erythropoietin treatment, received 4 doses of rituximab 375 mg/m2 weekly. After the 3rd dose of rituximab, she exhibited a striking rise in her reticulocyte count with an increase in her hemoglobin level. To our knowledge, this is the first case of PRCA following major ABO-compatible allogeneic HSCT resolving completely after rituximab treatment

    Epitaxial Growth of a Single-Crystal Hybridized Boron Nitride and Graphene layer on a Wide-Band Gap Semiconductor

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    Vertical and lateral heterogeneous structures of two-dimensional (2D) materials have paved the way for pioneering studies on the physics and applications of 2D materials. A hybridized hexagonal boron nitride (h-BN) and graphene lateral structure, a heterogeneous 2D structure, has been fabricated on single-crystal metals or metal foils by chemical vapor deposition (CVD). However, once fabricated on metals, the h-BN/graphene lateral structures require an additional transfer process for device applications, as reported for CVD graphene grown on metal foils. Here, we demonstrate that a single-crystal h-BN/graphene lateral structure can be epitaxially grown on a wide-gap semiconductor, SiC(0001). First, a single-crystal h-BN layer with the same orientation as bulk SiC was grown on a Si-terminated SiC substrate at 850 oC using borazine molecules. Second, when heated above 1150 oC in vacuum, the h-BN layer was partially removed and, subsequently, replaced with graphene domains. Interestingly, these graphene domains possess the same orientation as the h-BN layer, resulting in a single-crystal h-BN/graphene lateral structure on a whole sample area. For temperatures above 1600 oC, the single-crystal h-BN layer was completely replaced by the single-crystal graphene layer. The crystalline structure, electronic band structure, and atomic structure of the h-BN/graphene lateral structure were studied by using low energy electron diffraction, angle-resolved photoemission spectroscopy, and scanning tunneling microscopy, respectively. The h-BN/graphene lateral structure fabricated on a wide-gap semiconductor substrate can be directly applied to devices without a further transfer process, as reported for epitaxial graphene on a SiC substrate.Comment: 23 pages, 7 figure
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