55 research outputs found

    Molecular diagnosis of hereditary spherocytosis by multi-gene target sequencing in Korea: matching with osmotic fragility test and presence of spherocyte

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    Background Current diagnostic tests for hereditary spherocytosis (HS) focus on the detection of hemolysis or indirectly assessing defects of membrane protein, whereas direct methods to detect protein defects are complicated and difficult to implement. In the present study, we investigated the patterns of genetic variation associated with HS among patients clinically diagnosed with HS. Methods Multi-gene targeted sequencing of 43 genes (17 RBC membrane protein-encoding genes, 20 RBC enzyme-encoding genes, and six additional genes for the differential diagnosis) was performed using the Illumina HiSeq platform. Results Among 59 patients with HS, 50 (84.7%) had one or more significant variants in a RBC membrane protein-encoding genes. A total of 54 significant variants including 46 novel mutations were detected in six RBC membrane protein-encoding genes, with the highest number of variants found in SPTB (n = 28), and followed by ANK1 (n = 19), SLC4A1 (n = 3), SPTA1 (n = 2), EPB41 (n = 1), and EPB42 (n = 1). Concurrent mutations of genes encoding RBC enzymes (ALDOB, GAPDH, and GSR) were detected in three patients. UGT1A1 mutations were present in 24 patients (40.7%). Positive rate of osmotic fragility test was 86.8% among patients harboring HS-related gene mutations. Conclusions This constitutes the first large-scaled genetic study of Korean patients with HS. We demonstrated that multi-gene target sequencing is sensitive and feasible that can be used as a powerful tool for diagnosing HS. Considering the discrepancies of clinical and molecular diagnoses of HS, our findings suggest that molecular genetic analysis is required for accurate diagnosis of HS.Support was provided by: the National Research Foundation of Korea (NRF) grant funded by the Korea government(MSIT) (NRF-2017R1A2A1A17069780) http://www.nrf.re.kr/

    Acoustic Emission as a Tool of Fatigue Assessment

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    The effect of carbon on hydrogen embrittlement in stable Cr-Ni-Mn-N austenitic stainless steels

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    The effect of carbon on hydrogen embrittlement in stable austenitic stainless steels is investigated by adding either 0.02 or 0.1 wt.% C. During deformation, planar slip is pronounced and fine dislocation structures develop, which is followed by mechanical twinning in both steels. After hydrogen pre-charging, the alloy with higher carbon is more susceptible to hydrogen embrittlement. Based on strain hardening behaviour, it is proposed that C enhances planar slip and refines mechanical twins. Therefore, a higher C concentration results in more sites available for stress concentration and hydrogen trapping, and accelerates the embrittlement.118sciescopu

    Modified Ni equivalent for evaluating hydrogen susceptibility of Cr-Ni based austenitic stainless steels

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    In Cr-Ni austenitic stainless steels, Ni equivalent is an important indicator of austenite stability, and thereby, the resistance to hydrogen embrittlement. Although N is often added to Cr-Ni austenitic stainless steels as a strengthening element, its contribution to Ni equivalent has not been satisfactorily taken into account. Based on an up-to-date thermodynamic database, the existing Ni equivalents are reassessed, and a modified Ni equivalent is suggested to accurately consider the N effect on austenite stability. The newly suggested Ni equivalent equal to 27 is proposed to be the lower limit for the applications in hydrogen environment. (C) 2016 Elsevier B.V. All rights reserved.1132sciescopu

    Sclerotinia Rot on Basil Caused by Sclerotinia sclerotiorum in Korea

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    During growing season of 2011 to 2013, Sclerotinia rot symptoms consistently have been observed on basil in Yesan-gun, Chungcheongnam-do in Korea. The typical symptom formed initially brownish spot on leaf and stem, and then advancing margins, wilting the whole plant and blighting, eventually died. On the surface of diseased lesions was observed cottony, white, dense mat of mycelial growth, and sclerotia (30–100 µm diameter) formed on stem and leaf. Morphological and cultural characteristic on potato dextrose agar, color of colony was white and colorless chocolate, sclerotium of irregular shape of the oval was black and 5–50 µm diameter in size. In pathogenicity test, necrosis and wilt of the inoculated stem were observed in all plants and the pathogen was reisolated from stems. On the basis of mycological characteristics, pathogenicity, and internal transcribed spacer rDNA sequence analysis, this fungus was identified as Sclerotinia sclerotiorum. This is the first report of Sclerotinia rot on basil caused by S. sclerotiorum in Korea

    Biodegradable Magnesium Alloys Promote Angio‐Osteogenesis to Enhance Bone Repair

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    Biodegradable metallic materials represent a potential step‐change technology that may revolutionize the treatment of broken bones. Implants made with biodegradable metals are significantly stronger than their polymer counterparts and fully biodegradable in vivo, removing the need for secondary surgery or long‐term complications. Here, it is shown how clinically approved Mg alloy promotes improved bone repair using an integrated state of the art fetal mouse metatarsal assay coupled with in vivo preclinical studies, second harmonic generation, secretome array analysis, perfusion bioreactor, and high‐resolution 3D confocal imaging of vasculature within skeletal tissue, to reveal a vascular‐mediated pro‐osteogenic mechanism controlling enhanced tissue regeneration. The optimized mechanical properties and corrosion rate of the Mg alloy lead to a controlled release of metallic Mg, Ca, and Zn ions at a rate that facilitates both angiogenesis and coupled osteogenesis for better bone healing, without causing adverse effects at the implantation site. The findings from this study support ongoing development and refinement of biodegradable metal systems to act as crucial portal technologies with significant potential to improve many clinical applications

    Simulation Protocol for Prediction of a Solid-Electrolyte Interphase on the Silicon-based Anodes of a Lithium-Ion Battery: ReaxFF Reactive Force Field

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    We propose the ReaxFF reactive force field as a simulation protocol for predicting the evolution of solid-electrolyte interphase (SEI) components such as gases (C<sub>2</sub>H<sub>4</sub>, CO, CO<sub>2</sub>, CH<sub>4</sub>, and C<sub>2</sub>H<sub>6</sub>), and inorganic (Li<sub>2</sub>CO<sub>3</sub>, Li<sub>2</sub>O, and LiF) and organic (ROLi and ROCO<sub>2</sub>Li: R = −CH<sub>3</sub> or −C<sub>2</sub>H<sub>5</sub>) products that are generated by the chemical reactions between the anodes and liquid electrolytes. ReaxFF was developed from ab initio results, and a molecular dynamics simulation with ReaxFF realized the prediction of SEI formation under real experimental conditions and with a reasonable computational cost. We report the effects on SEI formation of different kinds of Si anodes (pristine Si and SiO<sub><i>x</i></sub>), of the different types and compositions of various carbonate electrolytes, and of the additives. From the results, we expect that ReaxFF will be very useful for the development of novel electrolytes or additives and for further advances in Li-ion battery technology

    Multifunctional Composite Coating as a Wear-Resistant Layer for the Bearing in Total Hip Joint Replacement

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    In this study, we developed Ti-TiN composite coatings with fine lamellar structures for use as an enhanced wear-resistant layer between the bearing components of the polymer-lined acetabular cup and the metal femoral head of total hip joint replacements (THRs). A plasma spraying deposition method was used to apply the composite coatings, and the thickness of TiN layer in the composite could be controlled by varying the flow rate of N<sub>2</sub> atmospheric gas. The surface properties, such as roughness and hardness, were analyzed, and the friction coefficient (μ) and wear rate (<i>k</i>) were measured using a bovine serum wear test. A biocompatibility test was performed to evaluate the toxicity of the composite coatings. Our experimental results reveal that the friction and wear resistance of composite coatings is superior to that of the metallic implant materials, and they have a higher level of fracture toughness as compared with other ceramic coatings because of a good balance between the hardness of the TiN and the toughness of the Ti. Furthermore, these coatings possessed excellent biocompatibility. The experimental results also demonstrate that the improved wear properties can be attributed to a certain level of unavoidable porosity that is due to the rapid solidification of liquid droplets during the plasma spraying process. The pores in the coating surface play an important role as a lubricant (bovine serum) reservoir, reducing the actual contact area and friction losses

    Computational design of Mg alloys with minimal galvanic corrosion

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    Formation of galvanic cells between constituent phases is largely responsible for corrosion in Mg-based alloys. We develop a methodology to calculate the electrochemical potentials of intermetallic compounds and alloys using a simple model based on the Born-Haber cycle. Calculated electrochemical potentials are used to predict and control the formation of galvanic cells and minimize corrosion. We demonstrate the applicability of our model by minimizing galvanic corrosion in Mg-3wt%Sr-xZn alloy by tailoring the Zn composition. The methodology proposed in this work is applicable for any general alloy system and will facilitate efficient design of corrosion resistant alloys

    Characteristics of Occupational Exposure to Benzene during Turnaround in the Petrochemical Industries

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    Objectives: The level of benzene exposure in the petrochemical industry during regular operation has been well established, but not in turnaround (TA), where high exposure may occur. In this study, the characteristics of occupational exposure to benzene during TA in the petrochemical companies were investigated in order to determine the best management strategies and improve the working environment. This was accomplished by evaluating the exposure level for the workers working in environments where benzene was being produced or used as an ingredient during the unit process.Methods: From 2003 to 2008, a total of 705 workers in three petrochemical companies in Korea were studied. Long- and short-term (< 1hr) samples were taken during TAs. TA was classified into three stages: shut-down, maintenance and start-up. All works were classified into 12 occupation categories.Results: The long-term geometric mean (GM) benzene exposure level was 0.025 (5.82) ppm (0.005-42.120ppm) and the short-term exposure concentration during TA was 0.020 (17.42) ppm (0.005-61.855ppm). The proportions of TA samples exceeding the time-weighted average, occupational exposure level (TWA-OEL in Korea, 1ppm) and the short-term exposure limit (STEL-OEL, 5ppm) were 4.1% (20 samples of 488) and 6.0% (13 samples of 217), respectively. The results for the benzene exposure levels and the rates of exceeding the OEL were both statistically significant (p < 0.05). Among the 12 job categories of petrochemical workers, mechanical engineers, plumbers, welders, fieldman and scaffolding workers exhibited long-term samples that exceeded the OEL of benzene, and the rate of exceeding the OEL was statistically significant for the first two occupations (p < 0.05).Conclusion: These findings suggest that the periodic work environment must be assessed during non-routine works such as TA
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