75 research outputs found

    Ultra-Fast Low Concentration Detection of Candida Pathogens Utilizing High Resolution Micropore Chips

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    Although Candida species are the fourth most common cause of nosocomial blood stream infections in the United States, early diagnostic tools for invasive candidemia are lacking. Due to an increasing rate of candidemia, a new screening system is needed to detect the Candida species in a timely manner. Here we describe a novel method of detection using a solid-state micro-scale pore similar to the operational principles of a Coulter counter. With a steady electrolyte current flowing through the pore, measurements are taken of changes in the current corresponding to the shape of individual yeasts as they translocate or travel through the pore. The direct ultra-fast low concentration electrical addressing of C. albicans has established criteria for distinguishing individual yeast based on their structural properties, which may reduce the currently used methods’ complexity for both identification and quantification capabilities in mixed blood samples

    Optical observations of NEA 3200 Phaethon (1983 TB) during the 2017 apparition

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    The near-Earth asteroid 3200 Phaethon (1983 TB) is an attractive object not only from a scientific viewpoint but also because of JAXA's DESTINY+ target. The rotational lightcurve and spin properties were investigated based on the data obtained in the ground-based observation campaign of Phaethon. We aim to refine the lightcurves and shape model of Phaethon using all available lightcurve datasets obtained via optical observation, as well as our time-series observation data from the 2017 apparition. Using eight 1-2-m telescopes and an optical imager, we acquired the optical lightcurves and derived the spin parameters of Phaethon. We applied the lightcurve inversion method and SAGE algorithm to deduce the convex and non-convex shape model and pole orientations. We analysed the optical lightcurve of Phaethon and derived a synodic and a sidereal rotational period of 3.6039 h, with an axis ratio of a/b = 1.07. The ecliptic longitude (lambda) and latitude (beta) of the pole orientation were determined as (308, -52) and (322, -40) via two independent methods. A non-convex model from the SAGE method, which exhibits a concavity feature, is also presented.Comment: 14 pages, 4 figures, 1 figure in Appendix A. Accepted for publication in Astronomy & Astrophysics (A&A

    Construction of a DNA Chip for Screening of Genetic Hearing Loss

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    ObjectivesHearing loss is the most common sensory disorder in humans and genetic causes are estimated to cause more than 50% of all incidents of congenital hearing loss. To develop an efficient method for a genetic diagnosis of hearing loss, we have developed and validated a genetic hearing loss DNA chip that allows the simultaneous analysis of 7 different mutations in the GJB2, SLC26A4, and the mtDNA 12S rRNA genes in Koreans.MethodsA genotyping microarray, based on the allele-specific primer extension (ASPE) method, was used and preliminary validation was examined from the five patients and five controls that were already known their genotypes by DNA sequencing analysis.ResultsThe cutoff Genotyping index (GI) of genotyping for each mutation was set up and validated to discriminate among the genotypes. The result of the DNA chip assay was identical to those of previous results.ConclusionWe successfully designed the genetic hearing loss DNA chip for the first time in Korea and it would be useful for a clinical genetic diagnosis of hearing loss. Further consideration will be needed in order to examine the accuracy of this DNA chip with much larger patient sample numbers

    Preoperative Magnetic Resonance Imaging Evaluation in Patients with Adolescent Idiopathic Scoliosis

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    Study DesignRetrospective case series.PurposeThe purpose of this study was to examine the incidence of neural axis abnormalities and the relevant risk factors in patients with adolescent idiopathic scoliosis (AIS).Overview of LiteratureThe use of preoperative magnetic resonance imaging (MRI) to assess the whole spine in patients with idiopathic scoliosis is controversial, and indications for such MRI evaluations have not been definitively established. However, we routinely use whole-spine MRI in patients with scoliosis who are scheduled to undergo surgical correction.MethodsA total of 378 consecutive patients with presumed AIS who were admitted for spinal surgery were examined for neural axis abnormalities using MRI. To differentiate patients with normal and abnormal MRI findings, the following clinical parameters were evaluated: age, sex, menarcheal status, rotation angle (using a scoliometer), coronal balance, shoulder height difference, and low back pain. We radiographically evaluated curve type, thoracic or thoracolumbar curve direction, curve magnitude and flexibility, apical vertebral rotation, curve length, coronal balance, sagittal balance, shoulder height difference, thoracic kyphosis, and the Risser sign.ResultsNeural axis abnormalities were detected in 24 patients (6.3%). Abnormal MRI findings were significantly more common in males than in females and were associated with increased thoracic kyphosis. However, there were no significant differences in terms of the other measured parameters.ConclusionsAmong the patients with presumed AIS who received preoperative whole-spine MRI, 6.3% had neural axis abnormalities. Males and patients with increased thoracic kyphosis were at a higher risk

    A genome-wide association study of copy-number variation identifies putative loci associated with osteoarthritis in Koreans

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Background OA is a complex disease caused by environmental and genetic risk factors. The purpose of this study is to identify candidate copy number variations (CNVs) associated with OA. Methods We performed a genome-wide association study of CNV to identify potential loci that confer susceptibility to or protection from OA. CNV genotyping was conducted using NimbleGen HD2 3 × 720K comparative hybridization array and included samples from 371 OA patients and 467 healthy controls. The putative CNV regions identified were confirmed with a TaqMan assay. Results We identified six genomic regions associated with OA encompassing CNV loci. None of six loci had previously been reported in genome-wide association studies with OA, although a genetic analysis suggested that they have functional effects. The protein product of a candidate risk gene for obesity, TNKS, targets Wnt inhibition, and this gene was significantly associated with hand and knee OA. Copy number deletion on TNKS was associated with a 1.37-fold decreased risk for OA. In addition, CA10, which shows a strong association with osteoporosis, was also significant in our study. Copy number deletion on this gene was associated with a 1.69-fold decreased risk for OA. Conclusion We identified several CNV loci that may contribute to OA susceptibility in Koreans. Further functional investigations of these genes are warranted to fully characterize their putative association
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