926 research outputs found

    Fault-Tolerant Gait Planning of Multi-Legged Robots

    Get PDF

    Case of Bilateral Retinal Neovascularization Associated with Chronic Idiopathic Myelofibrosis

    Get PDF
    We report a case of bilateral peripheral retinal neovascularization and chronic idiopathic myelofibrosis in a 69-year-old man. Ophthalmic examination revealed peripheral retinal nonperfusion with retinal neovascularization in both eyes and vitreous hemorrhage in the right eye. Fluorescein angiography of both eyes showed a marked midperipheral and peripheral avascular retina temporally with arteriovenous anastomosis and sea-fan neovascularizations. Blood tests showed pancytopenia and teardrop-shaped red blood cells, and bone marrow examination showed hypocellular marrow with severe fibrosis. The neovascularization was regressed following pars plana vitrectomy in the right eye and scatter laser photocoagulation in the left. The results suggest that peripheral retinal vessel occlusion and neovascularization may be associated with idiopathic myelofibrosis

    Effect of interlayer interactions on exciton luminescence in atomic-layered MoS2 crystals

    Get PDF
    The atomic-layered semiconducting materials of transition metal dichalcogenides are considered effective light sources with both potential applications in thin and flexible optoelectronics and novel functionalities. In spite of the great interest in optoelectronic properties of two-dimensional transition metal dichalcogenides, the excitonic properties still need to be addressed, specifically in terms of the interlayer interactions. Here, we report the distinct behavior of the A and B excitons in the presence of interlayer interactions of layered MoS 2 crystals. Micro-photoluminescence spectroscopic studies reveal that on the interlayer interactions in double layer MoS 2 crystals, the emission quantum yield of the A exciton is drastically changed, whereas that of the B exciton remains nearly constant for both single and double layer MoS 2 crystals. First-principles density functional theory calculations confirm that a significant charge redistribution occurs in the double layer MoS 2 due to the interlayer interactions producing a local electric field at the interfacial region. Analogous to the quantum-confined Stark effect, we suggest that the distinct behavior of the A and B excitons can be explained by a simplified band-bending model.1

    TURFs and Clubs: Empirical Evidence of the Effect of Selfgovernance Korea\u27s Inshore (maul) Fisheries

    Get PDF
    Self-governance of natural resources has started to gain increasing attention as an alternative to command-and-control and market-based tools. However, a fundamental question remains: is self-governance economically beneficial, allowing it to serve as an alternative management tool? This paper uses a unique set of survey data from a territorial-user-right-based South Korean inshore (maul) fishery and applies an empirical strategy to provide some of the first quantitative evidence that self-governance benefits maul fishermen.We find that members of the self-governance group perceive the management system as having had a positive impact on four out of the eight criteria we tested: stock recovery, curtailed fishing effort, reduced disputes among fishermen and declining incidents of illegal fishing. Considering that these groups have been in existence on average for less than seven years, these results indicate that the management scheme has made good progress overall

    Does Self Management in Fisheries Enhance Profitability? Examination of Korea’s Coastal Fisheries

    Get PDF
    Self management of natural resources has started to gain increasing attention as an alternative tool to command-and-control and market-based tools, but the fundamental question remains: is self management economically beneficial such that it should be promoted in the first place? This article uses a unique set of survey data from South Korea and applies an empirical strategy to provide some of the first quantitative evidence that self management is benefiting the fishermen. We find that positive benefits of fishery self management—an increase in fishery revenue and reduction in cost—are perceived by member fishermen, which is a good start considering the average number of years since the establishment of these self-management groups is only about seven. Empirical results of the magnitude of change in profit showed some consistent results, although the estimates were not as robust. These results suggest that the impact of fishery self management is still in progress. Thus, the government should maintain its current position to support self management as the country’s fishery management policy

    Copy Number Variation of Age-Related Macular Degeneration Relevant Genes in the Korean Population

    Get PDF
    PURPOSE: Studies that analyzed single nucleotide polymorphisms (SNP) in various genes have shown that genetic factors are strongly associated with age-related macular degeneration (AMD) susceptibility. Copy number variation (CNV) may be an additional type of genetic variation that contributes to AMD pathogenesis. This study investigated CNV in 4 AMD-relevant genes in Korean AMD patients and control subjects. METHODS: Four CNV candidate regions located in AMD-relevant genes (VEGFA, ARMS2/HTRA1, CFH and VLDLR), were selected based on the outcomes of our previous study which elucidated common CNVs in the Asian populations. Real-time PCR based TaqMan Copy Number Assays were performed on CNV candidates in 273 AMD patients and 257 control subjects. RESULTS: The predicted copy number (PCN, 0, 1, 2 or 3+) of each region was called using the CopyCaller program. All candidate genes except ARMS2/HTRA1 showed CNV in at least one individual, in which losses of VEGFA and VLDLR represent novel findings in the Asian population. When the frequencies of PCN were compared, only the gain in VLDLR showed significant differences between AMD patients and control subjects (p = 0.025). Comparisons of the raw copy values (RCV) revealed that 3 of 4 candidate genes showed significant differences (2.03 vs. 1.92 for VEGFA, p<0.01; 2.01 vs. 1.97 for CFH, p<0.01; 1.97 vs. 2.01, p<0.01 for ARMS2/HTRA1). CONCLUSION: CNVs located in AMD-relevant genes may be associated with AMD susceptibility. Further investigations encompassing larger patient cohorts are needed to elucidate the role of CNV in AMD pathogenesis

    Improved reversibility in lithium-oxygen battery: Understanding elementary reactions and surface charge engineering of metal alloy catalyst

    Get PDF
    Most Li-O-2 batteries suffer from sluggish kinetics during oxygen evolution reactions (OERs). To overcome this drawback, we take the lesson from other catalysis researches that showed improved catalytic activities by employing metal alloy catalysts. Such research effort has led us to find Pt3Co nanoparticles as an effective OER catalyst in Li-O-2 batteries. The superior catalytic activity was reflected in the substantially decreased overpotentials and improved cycling/rate performance compared to those of other catalysts. Density functional theory calculations suggested that the low OER overpotentials are associated with the reduced adsorption strength of LiO2 on the outermost Pt catalytic sites. Also, the alloy catalyst generates amorphous Li2O2 conformally coated around the catalyst and thus facilitates easier decomposition and higher reversibility. This investigation conveys an important message that understanding elementary reactions and surface charge engineering of air-catalysts are one of the most effective approaches in resolving the chronic sluggish charging kinetics in Li-O-2 batteries.

    A multicenter, prospective, randomized, controlled trial evaluating the safety and efficacy of intracoronary cell infusion mobilized with granulocyte colony-stimulating factor and darbepoetin after acute myocardial infarction: study design and rationale of the 'MAGIC cell-5-combination cytokine trial'

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Bone marrow derived stem/progenitor cell transplantation after acute myocardial infarction is safe and effective for improving left ventricular systolic function. However, the improvement of left ventricular systolic function is limited. This study will evaluate novel stem/progenitor cell therapy with combination cytokine treatment of the long-acting erythropoietin analogue, darbepoetin, and granulocyte colony-stimulating factor (G-CSF) in patients with acute myocardial infarction.</p> <p>Methods</p> <p>The 'MAGIC Cell-5-Combination Cytokine Trial' is a multicenter, prospective, randomized, 3-arm, controlled trial with blind evaluation of the endpoints. A total of 116 patients will randomly receive one of the following three treatments: an intravenous darbepoetin infusion and intracoronary infusion of peripheral blood stem cells mobilized with G-CSF (n = 58), an intracoronary infusion of peripheral blood stem cells mobilized with G-CSF alone (n = 29), or conventional therapy (n = 29) at phase I. Patients with left ventricular ejection fraction < 45% at 6 months, in the patients who received stem cell therapy at phase I, will receive repeated cell therapy at phase II. The objectives of this study are to evaluate the safety and efficacy of combination cytokine therapy with erythropoietin and G-CSF (phase I) and repeated progenitor/stem cell treatment (phase II).</p> <p>Discussion</p> <p>This is the first study to evaluate the safety and efficacy of combination cytokine based progenitor/stem cell treatment.</p> <p>Trial registration</p> <p><url>http://www.ClinicalTrials.gov</url> identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00501917">NCT00501917</a>.</p

    Fully gravure printed complementary carbon nanotube TFTs for a clock signal generator using an epoxy-imine based cross-linker as an n-dopant and encapsulant.

    Get PDF
    Printed p-type single walled carbon nanotube (SWCNT) based circuits exhibit high power dissipation owing to their thick printed dielectric layers (&gt;2 μm) and long channels (&gt;100 μm). In order to reduce the static power dissipation of printed SWCNT-base circuits while maintaining the same printing conditions and channel lengths, complementary metal-oxide-semiconductor (CMOS) based circuits are more ideal. These circuits, however, have not been successfully implemented in a scalable printing platform due to unstable threshold voltages of n-doped SWCNT based thin film transistors (TFTs). In this work, a thermally curable epoxy-imine-based n-doping ink is presented for achieving uniform doping and sealing of SWCNT layers by gravure printing. After printing the n-doping ink, the ink is cured to initiate a cross-linking reaction to seal the n-doped SWCNT-TFTs so that the threshold voltage of the n-doped SWCNT-TFTs is stabilized. Flexible CMOS ring oscillators using such n-doped SWCNT-TFTs combined with the intrinsically p-type SWCNT-TFTs can generate a 0.2 Hz clock signal with significantly lower power consumption compared to similarly printed p-type only TFT based ring oscillators. Moving forward, this CMOS flexible ring oscillator can be practically used to develop fully printed inexpensive wireless sensor tags
    corecore