343 research outputs found

    Metal work-function-dependent barrier height of Ni contacts with metal-embedded nanoparticles to 4H-SiC

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    Metal, typically gold [Au], nanoparticles [NPs] embedded in a capping metal contact layer onto silicon carbide [SiC] are considered to have practical applications in changing the barrier height of the original contacts. Here, we demonstrate the use of silver [Ag] NPs to effectively lower the barrier height of the electrical contacts to 4H-SiC. It has been shown that the barrier height of the fabricated SiC diode structures (Ni with embedded Ag-NPs) has significantly reduced by 0.11 eV and 0.18 eV with respect to the samples with Au-NPs and the reference samples, respectively. The experimental results have also been compared with both an analytic model based on Tung's theory and physics-based two-dimensional numerical simulations

    The Possible Role of Nitric Oxide on Enteric Nerves-Mediated Relaxation of the Gastric Smooth Muscle of the Guinea Pig

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    The influence of the enteric nerves stimulation on the contractility of gastric circular muscle was studied in guinea pig stomachs. The enteric nerves were activated by electric field stimulation(EFS; 90 V, 1 rns, 32 Hz square pulses for 1 s), EFS produced initial transient contraction followed by relaxation and slow recovery. The initial contraction was sensitively blocked by treatment with atropine. The following relaxation still occurred in nonadrenergic noncholinergidNANC) state. EFSinduced relaxation was reduced by LG-nitro-L-arginine(L-NNA), a nitric oxide(NO) synthase inhibitor. The relaxation was restored from the suppressed state after the application of L-arginine(L-arg), a substrate of nitric oxide synthase. With conventional intracellular recording, slow wave and inhibitory junction potential(IJP) were recorded. L-NNA had no effect on IJP, while apamin blocked it. In conclusion, it is suggested that NO may playa major role in EFS-induced relaxation. The exact mechanism of this relaxation is unknown, but the relaxation does not result from the IJP induced by the activation of apamin-sensitive potassium channels

    Reliability and Validity of the Severe Impairment Battery (SIB) in Korean Dementia Patients

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    This study was conducted to examine the reliability, validity and clinical utility of the Severe Impairment Battery (SIB) for a Korean population. 69 dementia patients with Clinical Dementia Rating (CDR) stages 2 or 3 were participated in this study. The SIB, Korean version-Mini Mental State Examination (K-MMSE), CDR, and Seoul-Activities of Daily Living (S-ADL) were administered. The validity of the SIB was confirmed by evaluating the correlation coefficients between the SIB and K-MMSE, CDR, S-ADL, which were found to be significant. Cronbach's alpha for the total SIB score and each subscale score showed high significance, and the item-total correlation for each subscale was also acceptable. The test-retest correlation for the total SIB score and subscale scores were significant, except for the praxis and orienting to name. The total SIB score and subscale scores were examined according to CDR. The results suggest that the SIB can differentiate the poor performances of severely impaired dementia patients. On the basis of the receiver operating characteristic (ROC), it can be concluded that the SIB is able to accurately discriminate between CDR 2 and 3 patients. The results of this study suggest that the SIB is a reliable and valid instrument for evaluating severe dementia patients in Korean population

    X-linked Opitz G/BBB Syndrome: Identification of a Novel Mutation and Prenatal Diagnosis in a Korean Family

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    X-linked Opitz G/BBB syndrome (XLOS; MIM 300000) is a rare multiple congenital anomaly disorder that is characterized by facial anomalies, laryngeal/tracheal/esophageal defects and genitourinary abnormalities. XLOS is caused by mutations in the MID1 gene which encodes a microtubule-associated RING-Bbox-Coiled-coil (RBCC) protein. We recently found a four-year Korean male patient who was suspected of having XLOS. Mutation analysis of the MID1 gene in the patient and his mother demonstrated that the patient had a novel insertion mutation (c.1798_1799insC), and his mother was a heterozygous carrier of the mutation. After identification of the causative mutation in this family, prenatal diagnosis of two consecutive fetuses were successfully undertaken. This is the first report on a genetically confirmed case of XLOS in Korea

    Cystic Fibrosis in Korean Children: A Case Report Identified by a Quantitative Pilocarpine Iontophoresis Sweat Test and Genetic Analysis

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    Cystic fibrosis (CF) is inherited as an autosomal recessive trait, and the mutations in cystic fibrosis transmembrane conductance regulator (CFTR) gene contributes to the CF syndrome. Although CF is common in Caucasians, it is known to be rare in Asians. Recently, we experienced two cases of CF in Korean children. The patients were girls with chronic productive cough since early infancy. Chest computed tomography showed the diffuse bronchiectasis in both lungs, and their diagnosis was confirmed by the repeated analysis of a quantitative pilocarpine iontophoresis test (QPIT). The sweat chloride concentrations of the first patient were 108.1 mM/L and 96.7 mM/L. The genetic analysis revealed that she was the compound heterozygote of Q1291X and IVS8 T5-M470V. In the second case, the sweat chloride concentrations were 95.0 mM/L and 77.5 mM/L. Although we performed a comprehensive search for the coding regions and exon-intron splicing junctions of CFTR gene, no obvious disease-related mutations were detected in the second case. To our knowledge, this is the first report of CF in Korean children identified by a QPIT and genetic analysis. The possibility of CF should be suspected in those patients with chronic respiratory symptoms even in Korea

    Towards accurate rescaling of a halo mass function

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    We investigate the precision within which a simulated dark matter halo mass function can be rescaled to a different set of cosmological parameters. Our tests show that the accuracy almost linearly depends on the difference of the cosmological parameters and amounts to few percent in the case of WMAP5 and PLANCK parameters. The rescaling thus allows us to obtain a mass function with better precision than the one given by the Sheth-Mo-Tormen approximation and even more modern fits currently used in the literature
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