610 research outputs found

    Controllable modification of transport properties of single-walled carbon nanotube field effect transistors with in situ Al decoration

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    We use an in situ Al decoration technique to control the transport characteristics of single-walled carbon nanotube field effect transistors (SWNT-FETs). Al nanoparticle decoration in a high vacuum caused the devices to change from p -type to n -type FETs, and subsequent exposure to the ambient atmosphere induced a gradual recovery of p -type character. In comparison with the bare SWNT-FETs under high vacuum, the channel-open devices with decorated Al particles exhibited reduced current under ambient conditions. However, selective Al decoration only at the contact resulted in an improved p -type current in ambient air.open182

    Hu.4-1BB-Fc fusion protein inhibits allergic inflammation and airway hyperresponsiveness in a murine model of asthma

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    Purpose4-1BB (CD 137) is a costimulatory molecule expressed on activated T-cells. Repression by 4-1BB is thought to attenuate Th2-mediated allergic reactions. The aim of this study was to investigate the effect of 4-1BB on allergic airway inflammation in a murine asthma model.MethodsBALB/c mice were sensitized to and challenged with ovalbumin (OVA). Hu.4-1BB-Fc was administered 1 day before the first OVA sensitization or 1 day after the second OVA sensitization. Following antigen challenge, airway responsiveness to methacholine was assessed and bronchoalveolar lavage (BAL) fluid was analyzed. Total immunoglobulin (Ig) E, OVA-specific IgE, IgG1, and IgG2a levels in sera were measured by enzyme-linked immunosorbent assay. Lung pathology was also evaluated.ResultsIn mice treated with Hu.4-1BB-Fc before the first OVA sensitization, there was a marked decrease in airway hyperresponsiveness, total cell count, and eosinophil count in the BAL fluid. In addition, Hu.4-1BB-Fc treatment decreased serum OVA-specific IgG1 levels and increased serum IgG2a level significantly compared with the corresponding levels in mice sensitized to and challenged with OVA. Hu.4-1BB-Fc-treated mice also showed suppressed peribronchial and perivascular inflammatory cell infiltration. In contrast, treatment with Hu.4-1BB-Fc 1 day after sensitization had no effect on airway hyperresponsiveness and showed less suppression of inflammation in lung tissue.ConclusionAdministration of Hu.4-1BB-Fc can attenuate airway inflammation and hyperreactivity in a mouse model of allergic airway inflammation. In addition, administration before sensitization may be more effective. These findings suggest that 4-1BB may be a useful therapeutic molecule against asthma

    Carbon nanotube diode fabricated by contact engineering with self-assembled molecules

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    The authors report the construction of carbon nanotube Schottky diodes by covering a selectively exposed area of the electrode with self-assembling molecules. Two self-assembling molecules with different polarities, 2-aminoethanethiol and 3-mercaptopropionic acid, were used to modify the Fermi level lineup at the selected contact. The devices showed p -type behavior with symmetric I-V showing clear rectifying behavior after treatment of one contact with 2-aminoethanethiol. Their experiment, in conjunction with the results of ab initio electronic structure calculations, suggests that the diode action stems from the asymmetric Fermi level lineup between the bare and engineered contacts.open131

    Changes in the Prevalence of Childhood Asthma in Seoul from 1995 to 2008 and Its Risk Factors

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    PURPOSE: To investigate the prevalence of asthma and determine its risk factors in elementary school students in Seoul. METHODS: A modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was used to survey 4,731 elementary school students from five areas in Seoul between April and October, 2008. RESULTS: In elementary school children, the lifetime and recent 12-month prevalence of wheezing were 11.7% and 5.6%, respectively. The lifetime prevalence of asthma diagnosis was 7.9%, and the recent 12-month prevalence of asthma treatment was 2.7%. Male sex (adjusted odds ratio [aOR], 1.90; 95% confidence interval [CI], 1.36-2.66), history of atopic dermatitis (AD) (aOR, 2.76; 95% CI, 1.98-3.84), history of allergic rhinitis (AR) (aOR, 3.71; 95% CI, 2.61-5.26), history of bronchiolitis before 2 years of age (aOR, 2.06; 95% CI, 1.39-3.07), use of antibiotics during infancy for >3 days (aOR, 1.88; 95% CI, 1.35-2.62), parental history of asthma (aOR, 2.83; 95% CI, 1.52-5.27), exposure to household molds during infancy (aOR, 1.84; 95% CI, 1.18-2.89), and the development or aggravation of asthma symptoms within 6 months after moving to a new house (aOR, 11.76; 95% CI, 5.35-25.86) were the independent risk factors for wheezing within 12 months. CONCLUSIONS: The prevalence of wheezing and asthma in elementary school students in 2008 was similar to that in the past decade. Male sex, history of AD, history of AR, history of bronchiolitis before 2 years of age, parental asthma, use of antibiotics during infancy, exposure to molds in the house during infancy, and development or aggravation of asthma symptoms within 6 months after moving to a new house, could be risk factors for wheezing within 12 months.ope

    Clinical characteristics of myelin oligodendrocyte glycoprotein antibody-associated disease according to their epitopes

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    BackgroundThe detection of myelin oligodendrocyte glycoprotein autoantibodies (MOG-Ab) is essential for the diagnosis of MOG-Ab-associated disease (MOGAD). The clinical implications of different epitopes recognized by MOG-Ab are largely unknown. In this study, we established an in-house cell-based immunoassay for detecting MOG-Ab epitopes and examined the clinical characteristics of patients with MOG-Ab according to their epitopes.MethodsWe conducted a retrospective review of patients with MOG-Ab-associated disease (MOGAD) in our single center registry, and collected serum samples from enrolled patients. Human MOG variants were generated to detect epitopes recognized by MOG-Ab. The differences in clinical characteristics according to the presence of reactivity to MOG Proline42 (P42) were evaluated.ResultsFifty five patients with MOGAD were enrolled. Optic neuritis was the most common presenting syndrome. The P42 position of MOG was a major epitope of MOG-Ab. The patients with a monophasic clinical course and childhood-onset patients were only observed in the group that showed reactivity to the P42 epitope.ConclusionWe developed an in-house cell-based immunoassay to analyze the epitopes of MOG-Ab. The P42 position of MOG is the primary target of MOG-Ab in Korean patients with MOGAD. Further studies are needed to determine the predictive value of MOG-Ab and its epitopes

    Biological Profiles of Korean Atomic Bomb Survivors in Residence at Daegu and Kyungbuk, Republic of Korea

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    In 1945, many Koreans, in addition to Japanese, were killed or injured by the atomic bombs dropped on Hiroshima and Nagasaki, Japan. This study compared the biological profiles of Korean atomic bomb survivors in residence at Daegu and Kyungbuk, Republic of Korea with those of a representative sample of Koreans obtained during a similar period. We evaluated anthropometric measurements, blood pressure, blood cell counts, blood chemistry, and urinalysis of survivors (n=414) and age- and sex-matched controls (n=414) recruited from the third Korea National Health and Nutrition Examination Survey conducted in 2005. Univariate analyses revealed significantly higher systolic blood pressure, white blood cell count, and serum total cholesterol, triglycerides, high-density lipoprotein-cholesterol, and aspartate aminotransferase levels (p<0.01) in the survivors. Conversely, hemoglobin concentration, hematocrit, red blood cell count, and the proportion of positive urine occult blood (p<0.01) were lower in the survivors. Our findings suggest that biological profiles of Korean atomic bomb survivors were adversely affected by radiation exposure
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