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Unilateral Biportal Endoscopic Spinal Surgery Using a 30° Arthroscope for L5-S1 Foraminal Decompression

  • Kim, Ju-Eun;Choi, Dae-Jung
    • Clinics in Orthopedic Surgery
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    • v.10 no.4
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    • pp.508-512
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    • 2018
  • Foraminal decompression using a minimally invasive technique to preserve facet joint stability and function without fusion reportedly improves the radicular symptoms in approximately 80% of patients and is considered one of the good surgical treatment choices for lumbar foraminal or extraforaminal stenosis. However, proper decompression was not possible because of the inability to access the foramen at the L5-S1 level due to prominence of the iliac crest. To overcome this challenge, endoscopy-based minimally invasive spine surgery has recently gained attention. Here, we report the technical skills required in unilateral extraforaminal biportal endoscopic spinal surgery using a $30^{\circ}$ arthroscope to enable foraminal decompression at the L5-S1 level. Two 0.8-cm portals were created 2 cm lateral from the lateral border of the pedicles at the L5-S1 level. After sufficient working space was made, half of the superior articular process (SAP) in the hypertrophied facet joint was removed using a high-speed burr and a 5-mm wide osteotome, whereas the remaining inside part of the SAP was removed using a Kerrison punch and pituitary punch. The foraminal ligamentum flavum should be removed to inspect the conditions of the L5 exiting root and disc. Removing of the extruded disc could decompress the L5 root. The extraforaminal approach using a $30^{\circ}$ arthroscope is considered a minimally invasive alternative technique for decompressing foraminal stenosis at the L5-S1 level that preserves facet stability and provides symptomatic relief.

Developmental Delay Effect of Harpacticoid Copepod, Tigriopus japonicus s.l. Exposure to 4-tert-octylphenol (4-tert -octylphenol에 노출된 저서성 요각류 Tigriopus japonicus s.l.의 발생지연 현상)

  • Bang, Hyun-Woo;Lee, Won-Choel;Kwak, Inn-Sil
    • Environmental Analysis Health and Toxicology
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    • v.23 no.2
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    • pp.93-100
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    • 2008
  • The ecotoxicological effects of 4-tert-octylphenol were observed on Harpacticoid copepoda Tigriopus japonicus s.l. gathered and cultured from tidal pool of Korean coast. There were no significant differences in survival rate (except 10 $\mu$g/L; 70.00%) and sex ratio (except 30 $\mu$g/L) on T. japonicus s.l. exposed to 4-tert-octylphenol. However, 4-tert-octylphenol induced developmental delay (copepodite emergence day and adult male mergence day) and retardation of first brooding day of adult female. Moreover the body size and biomass decreased at 4-tert-octylphenol exposure. As a result, detailed life-cycle research of T. japonicus s.l. may yield potential bioindicators for environmental monitoring and assessment.

The BioFlex System as a Dynamic Stabilization Device : Does It Preserve Lumbar Motion?

  • Zhang, Ho-Yeol;Park, Jeong-Yoon;Cho, Bo-Young
    • Journal of Korean Neurosurgical Society
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    • v.46 no.5
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    • pp.431-436
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    • 2009
  • Objective : This study examines whether functional motion is present at one or more years after Bioflex System placement. BioFlex System is a flexible rod system which has been used to preserve motion at the area of implantation. There has not been a scientific study showing how much motion is preserved after implantation. Methods : A total of 12 consecutive patients underwent posterior dynamic stabilization using the BioFlex System. Six patients were treated using a L3-4-5 construct and other six patients using a L4-5-S1 construct. Follow-up ranged from 12 to 33 months and standing neutral lateral, extension, flexion and posteroanterior (PA) radiographs were obtained at 3, 6, 9, and 12 months and at more than 12 months postoperatively. Range of motion (ROM), whole lumbar lordosis, and ROMs of motion segments from L2 to S1 were determined. Results : Patients with a L3-4-5 construct demonstrated a decrease in mean ROM for whole lumbar decreased from 40.08 to 30.77. Mean ROM for L3-4 (6.12 to 2.20) and L4-5 (6.55 to 1.67) also decreased after one year. Patients with a L4-5-S1 construct demonstrated L4-5 (8.75 to 2.70) and L5-S1 (9.97 to 3.25) decrease of mean ROM at one year postoperatively. Lumbar lordosis was preservep at both L3-4-5 and L4-5-S1 constructs. Clinical results showed significant improvements in both study groups. Conclusion : The present study provides preliminary information regarding the BioFlex motion preservation system. We conclude that the BioFlex System preserves functional motion to some degree at instrumented levels. However, although total lumbar lordosis was preserved, ROMs at implantation segments were lower than preoperative values.

Computational Materials Engineering: Recent Applications of VASP in the MedeA® Software Environment

  • Wimmer, Erich;Christensen, Mikael;Eyert, Volker;Wolf, Walter;Reith, David;Rozanska, Xavier;Freeman, Clive;Saxe, Paul
    • Journal of the Korean Ceramic Society
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    • v.53 no.3
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    • pp.263-272
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    • 2016
  • Electronic structure calculations have become a powerful foundation for computational materials engineering. Four major factors have enabled this unprecedented evolution, namely (i) the development of density functional theory (DFT), (ii) the creation of highly efficient computer programs to solve the Kohn-Sham equations, (iii) the integration of these programs into productivity-oriented computational environments, and (iv) the phenomenal increase of computing power. In this context, we describe recent applications of the Vienna Ab-initio Simulation Package (VASP) within the MedeA$^{(R)}$ computational environment, which provides interoperability with a comprehensive range of modeling and simulation tools. The focus is on technological applications including microelectronic materials, Li-ion batteries, high-performance ceramics, silicon carbide, and Zr alloys for nuclear power generation. A discussion of current trends including high-throughput calculations concludes this article.

ON THE STOCHASTIC PROCESS X(t, ω) ∈ L2s.a.p.

  • Choo, Jong Mi
    • Journal of the Chungcheong Mathematical Society
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    • v.17 no.2
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    • pp.197-203
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    • 2004
  • We find some properties of a stochastic processX(t, ${\omega}$) ${\in}L^2_{s.a.p.}$ which is of bounded variation.

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Listeria monocytogenes Serovar 4a is a Possible Evolutionary Intermediate Between L. monocytogenes Serovars 1/2a and 4b and L. innocua

  • Chen, Jianshun;Jiang, Lingli;Chen, Xueyan;Luo, Xiaokai;Chen, Yang;Yu, Ying;Tian, Guoming;Liu, Dongyou;Fang, Weihuan
    • Journal of Microbiology and Biotechnology
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    • v.19 no.3
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    • pp.238-249
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    • 2009
  • The genus Listeria consists of six closely related species and forms three phylogenetic groups: L. monocytogenes-L. innocua, L. ivanovii-L. seeligeri-L. welshimeri, and L. grayi. In this report, we attempted to examine the evolutionary relationship in the L. monocytogenes-L. innocua group by probing the nucleotide sequences of 23S rRNA and 16S rRNA, and the gene clusters lmo0029-lmo0042, ascB-dapE, rplS-infC, and prs-ldh in L. monocytogenes serovars 1/2a, 4a, and 4b, and L. innocua. Additionally, we assessed the status of L. monocytogenes-specific inlA and inlB genes and 10 L. innocua-specific genes in these species/serovars, together with phenotypic characterization by using in vivo and in vitro procedures. The results indicate that L. monocytogenes serovar 4a strains are genetically similar to L. innocua in the lmo0035-lmo0042, ascB-dapE, and rplS-infC regions and also possess L. innocua-specific genes lin0372 and lin1073. Furthermore, both L. monocytogenes serovar 4a and L. innocua exhibit impaired intercellular spread ability and negligible pathogenicity in mouse model. On the other hand, despite resembling L. monocytogenes serovars 1/2a and 4b in having a nearly identical virulence gene cluster, and inlA and inlB genes, these serovar 4a strains differ from serovars 1/2a and 4b by harboring notably altered actA and plcB genes, displaying strong phospholipase activity and subdued in vivo and in vitro virulence. Thus, by possessing many genes common to L. monocytogenes serovars 1/2a and 4b, and sharing many similar gene deletions with L. innocua, L. monocytogenes serovar 4a represents a possible evolutionary intermediate between L. monocytogenes serovars 1/2a and 4b and L. innocua.

A taxonomic review of Korean Lycoris (Amaryllidaceae) (한국산 상사화속(Lycoris, 수선화과)의 분류학적 재검토)

  • Kim, Muyeol
    • Korean Journal of Plant Taxonomy
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    • v.34 no.1
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    • pp.9-26
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    • 2004
  • Texa of Lycoris in Korea were classified as five species with two varieties and revised taxonomically. Among the examined taxa, five Korean endemic plants were clarified: Lycoris flavescens M. Kim et S. Lee, L. uydoensis M. Kim, L. chejuensis Tae et S. Ko, L. chinensis var. sinuolata Tae et S. Ko, and L. sanguinea var. koreana (Nakai) T. Koyama. It was found that L. flavescens, L. uydoensis, and L. chejuensis were the natural hybrids between taxa of M+T karyotype and A karyotype. A specimen collected on Aug. 20, 1987 by M. Kim was designated as a holotype of Lycoris flavescens M. Kim et S. Lee. Lycoris flavescens var. uydoensis was ranked up to L. uydoensis. A key to all species including descriptions of each taxon was provided.

Antimicrobial Effect of Phytochemicals to Listeria monocytogenes Isolated from Slaughterhouses

  • Kim, Hyeji;Oh, Hyemin;Lee, Heeyoung;Kim, Sejeong;Ha, Jimyeong;Lee, Jeeyeon;Choi, Yukyung;Lee, Yewon;Kim, Yujin;Yoon, Yohan;Lee, Soomin
    • Journal of Food Hygiene and Safety
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    • v.33 no.4
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    • pp.255-258
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    • 2018
  • The objective of this study was to investigate the inhibitory effect of natural antimicrobials on Listeria monocytogenes isolated from Korean slaughterhouses. A mixture of 15 strains of L. monocytogenes at low (3 Log CFU/mL) or high (7 Log CFU/mL) concentration was exposed to various extracts (grapefruit seed extract, citrus fruit extract, ginger extract, pear extract, Japanese apricot concentrate, balloon flower extract, jujube extract, and omija extract) at $0.001-4.0{\mu}g/mL$. Ginger extract, pear extract, Japanese apricot concentrate, balloon flower extract, jujube extract, or omija extract showed no antimicrobial effects on high-concentration of L. monocytogenes (7 Log CFU/mL). However, grapefruit seed extract and citrus fruit extract showed antibacterial effects against L. monocytogenes at 3 and 7 Log CFU/mL with MBCs of 0.001 and $0.002{\mu}g/mL$, respectively. These results indicate that grapefruit seed extract and citrus fruits extract can be used to control L. monocytogenes as natural antimicrobials.

Design and Simulation on the Characteristics of SRM (스위치드 럴럭턴스 모터의 설계와 특성 시뮬레이션)

  • Jang, S.M.;Seo, J.H.;Jeong, S.S.;Moon, J.S.;Seong, S.J.
    • Proceedings of the KIEE Conference
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    • 1997.07a
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    • pp.297-299
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    • 1997
  • The switched reluctance motor is an electric machine in which torque is produced by the tendency of its movable part to move to a position where the inductance of the excited winding is maxmized. It is as well as PM brushless do systems. It's many advantages-a wide speed range, and inherently simplicity and ruggedness, low manufacturing cost, make it a vigorous challenger to these drives. It is a fascinating machine with all kinds of interesting application possibilities. In this paper, the design and evaluate the performance is treated.

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