552 research outputs found

    Proto-type installation of a double-station system for the optical-video-detection and orbital characterisation of a meteor/fireball in South Korea

    Get PDF
    We give a detailed description of the installation and operation of a double-station meteor detection system which formed part of a research & education project between Korea Astronomy Space Science Institute and Daejeon Science Highschool. A total of six light-sensitive CCD cameras were installed with three cameras at SOAO and three cameras at BOAO observatory. A double-station observation of a meteor event enables the determination of the three-dimensional orbit in space. This project was initiated in response to the Jinju fireball event in March 2014. The cameras were installed in October/November 2014. The two stations are identical in hardware as well as software. Each station employes sensitive Watec-902H2 cameras in combination with relatively fast f/1.2 lenses. Various fields of views were used for measuring differences in detection rates of meteor events. We employed the SonotaCo UFO software suite for meteor detection and their subsequent analysis. The system setup as well as installation/operation experience is described and first results are presented. We also give a brief overview of historic as well as recent meteor (fall) detections in South Korea. For more information please consult http://meteor.kasi.re.kr .Comment: Technical/instrumentation description of a professional meteor detection system, 23 pages, 20 figures (color/monochrome), 5 tables, submitted to the Journal of Korean Astronomical Society (JKAS, http://jkas.kas.org/, http://jkas.kas.org/history.html

    Biomarkers of Oxidative Stress and Endogenous Antioxidants for Patients with Chronic Subjective Dizziness

    Get PDF
    As a neurotologic disorder of persistent non-vertiginous dizziness, chronic subjective dizziness (CSD) arises unsteadily by psychological and physiological imbalance. The CSD is hypersensitivity reaction due to exposure to complex motions visual stimuli. However, the pathophysiological features and mechanism of the CSD still remains unclearly. The present study was purposed to establish possible endogenous contributors of the CSD using serum samples from patients with the CSD. A total 199 participants were gathered and divided into two groups; healthy (n = 152, male for 61, and female for 91) and CSD (n = 47, male for 5, female for 42), respectively. Oxidative stress parameters such as, hydrogen peroxide and reactive substances were significantly elevated (p < 0.01 or p < 0.001), whereas endogenous antioxidant components including total glutathione contents, and activities of catalase and superoxide dismutase were significantly deteriorated in the CSD group (p < 0.01 or p < 0.001) as comparing to the healthy group, respectively. Serum levels of tumor necrosis factor -α and interferon-γ were significantly increased in the CSD participants (p < 0.001). Additionally, emotional stress related hormones including cortisol, adrenaline, and serotonin were abnormally observed in the serum levels of the CSD group (p < 0.01 or p < 0.001). Our results confirmed that oxidative stress and antioxidants are a critical contributor of pathophysiology of the CSD, and that is first explored to establish features of redox system in the CSD subjects compared to a healthy population

    Laparoscopic low anterior resection for hematogenous rectal metastasis from gastric adenocarcinoma: A Case Report

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Gastric cancer is one of the most common malignancies in the world and is the second most common cause of cancer-related death in Korea. Colorectal metastases from gastric adenocarcinoma are known to be very rare. We report an unusual case of rectal metastasis of gastric adenocarcinoma.</p> <p>Case presentation</p> <p>We report a case of a 43-year-old female patient with gastric cancer who first presented with epigastric pain. The endoscopic and radiologic findings were suggestive of Borrmann type III advanced gastric cancer with linitis plastica. Radical total gastrectomy with D2 lymph node dissection was performed. The pathology report was AJCC TNM Stage II gastric adenocarcinoma (T3N0M0). On follow up at 34 months after surgery, the patient complained of difficulty in defecation. On colonoscopy, a hard, indurated extraluminal mass was detected 7 cm proximal to the anal verge. The biopsy demonstrated chronic nonspecific colitis. Abdominal CT, rectal MRI and PET-CT revealed rectal metastasis from gastric cancer. Laparoscopic ultralow anterior resection with diverting ileostomy was performed. The pathology report was metastatic adenocarcinoma, and this diagnosis was identical to the gastric pathology reported in the previous pathology report. The patient was discharged after the 11<sup>th </sup>postoperative day with no adverse events.</p> <p>Conclusion</p> <p>Rectal metastasis from gastric cancer is known to be very rare. However, metastatic gastric adenocarcinoma should be considered as a differential diagnosis for patients presenting with a colorectal mass and a past history of gastric cancer.</p

    Nanoscale reaction vessels: Highly ordered nanocrystal arrays inside porous anodic alumina nanowells

    Get PDF
    Using an anodic alumina template as a nanoscale reaction vessel, the authors developed a simple and unique method to prepare highly ordered arrays of nanocrystals in isolated nanowells. The highly ordered arrays of nanoscale wells were fabricated by short anodization. After the nanoscale wells were filled with a precursor solution of NaCl by dewetting, the solvent of the precursor solution was evaporated, resulting in spontaneous formation of uniformly sized NaCl nanocrystals inside the nanoscale wells. The size of crystals could be easily adjusted by varying the concentration of the precursor solution and the size of nanoscale wells. This approach is simple and cost-effective, and it can fabricate nanocrystal arrays on substrates with high throughput. It can also be readily adapted to synthesize other types of high-density nanocrystal arrays on different substrates. &amp;#169; 2015 The Authorsopen0

    Effect of Wavelength and Intensity of Light on a-InGaZnO TFTs under Negative Bias Illumination Stress

    Get PDF
    We investigated degradation mechanism of a-IGZO TFTs under NBIS with different wavelengths. and intensities IL of light. Negative gate bias was applied for 4000 s while drain and source were grounded, and illuminations with lambda = 450, 530, or 700 nm were applied. Illumination with photon energy exceeding similar to 2.3 eV (530 nm) induced noticeable change in threshold voltage shift Delta V-th, which can be interpreted in terms of ionization of oxygen vacancies V-O. In addition, I-L of blue illumination (450 nm) was varied from 6 to 200 lux and saturation in Delta V-th was observed after exceeding a certain I-L. We suggest that the saturation occurs because V-O-ionization rate is saturated by outward relaxation of metal atoms in the a-IGZO film. (C) The Author(s) 2016. Published by ECS.1174Ysciescopu

    Genetic variation of aldolase from Korean isolates of Plasmodium vivax and its usefulness in serodiagnosis

    Get PDF
    Background: The malaria aldolase is widely used as rapid diagnostic test (RDT), but the efficacy in aspect of its serological effectiveness in diagnosis is not known. The genetic variation of Korean isolates was analysed and recombinant aldolase was evaluated as a serological antigen in Plasmodium vivax malaria. Methods: Genomic DNA was purified and the aldolase gene of P. vivax from 25 patients’ blood samples was amplified. The samples came from 5 epidemic areas; Bucheon-si, Gimpo-si, Paju-si of Gyeonggido, Gangwha-gun of Incheon metropolitan city, and Cheorwon of Gangwon-do, South Korea. The antigenicity of the recombinant aldolase was tested by western blot and enzyme-linked immunosorbent assay (ELISA). Results: Sequence analysis of 25 Korean isolates of P. vivax showed that the open reading frame (ORF) of 1,110 nucleotides encoded a deduced protein of 369 amino acids (aa). This ORF showed 100% homology with the P. vivax Sal I strain (XM_00165894) and P. vivax WDK strain (AF247063), 87.4% homology with Plasmodium falciparum (AF179421), 90.6% homology with Plasmodium chabaudi (AF247060), 89.5% homology with Plasmodium vinckei (AF247061), and 96.7% homology with Plasmodium knowlesi. A single nucleotide polymorphism (SNP) at nucleotide 180 (G to A, n = 5) was also observed in the isolates. The expressed recombinant protein had a molecular weight of approximately 31 kDa (monomeric form) and 62 kDa (dimeric form) as analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Among 109 P. vivax patients, 32 (29.4%) had positive in an enzyme-linked absorbance assay (ELISA). This result showed significant correlation between ELISA and an indirect fluorescent antibody test (IFAT) (P < 0.0001). Conclusions: The aldolase gene from Korean isolates of P. vivax showed one SNP at nucleotide position 180; this SNP mutant was discovered in only the western part of Han River, and included the regions of Ganghwa, Gimpo, and Bucheon. Based on the results, the relationship between antibody production against aldolase and the pattern of disease onset should be more investigated before using aldolase for serodiagnosis

    OsDIRP1, a Putative RING E3 Ligase, Plays an Opposite Role in Drought and Cold Stress Responses as a Negative and Positive Factor, Respectively, in Rice (Oryza sativa L.)

    Get PDF
    As higher plants are sessile organisms, they are unable to move to more favorable places; thus, they have developed the ability to survive under potentially detrimental conditions. Ubiquitination is a crucial post-translational protein modification and participates in abiotic stress responses in higher plants. In this study, we identified and characterized OsDIRP1 (Oryza sativa Drought-Induced RING Protein 1), a nuclear-localized putative RING E3 ubiquitin (Ub) ligase in rice (Oryza sativa L.). OsDIRP1 expression was induced by drought, high salinity, and abscisic acid (ABA) treatment, but not by low temperature (4°C) stress, suggesting that OsDIRP1 is differentially regulated by different abiotic stresses. To investigate its possible role in abiotic stress responses, OsDIRP1-overexpressing transgenic rice plants (Ubi:OsDIRP1-sGFP) were generated, and their phenotypes were analyzed. The T4 Ubi:OsDIRP1-sGFP lines showed decreased tolerance to drought and salt stress as compared to wild-type rice plants. Moreover, Ubi:OsDIRP1-sGFP progeny were less sensitive to ABA than the wild-type during both germination and post-germination growth. In contrast, Ubi:OsDIRP1-sGFP plants exhibited markedly higher tolerance to prolonged cold (4°C) treatment. These results suggest that OsDIRP1 acts as a negative regulator during drought and salt stress, whereas it functions as a positive factor during the cold stress response in rice
    corecore