Significance of Facet Fluid Index in Anterior Cervical Degenerative Spondylolisthesis

Lee Yunsoo,Heard Jeremy C.,Lambrechts Mark J.,Kern Nathaniel,Wiafe Bright,Goodman Perry,Mangan John J.,Canseco Jose A.,Kurd Mark F.,Kaye Ian D.,Hilibrand Alan S.,Vaccaro Alexander R.,Kepler Christophe 대한척추외과학회 2024 Asian Spine Journal Vol.18 No.1

Study Design: Retrospective cohort study.Purpose: To correlate cervical facet fluid characteristics to radiographic spondylolisthesis, determine if facet fluid is associated with instability in cervical degenerative spondylolisthesis, and examine whether vertebral levels with certain facet fluid characteristics and spondylolisthesis are more likely to be operated on.Overview of Literature: The relationship between facet fluid and lumbar spondylolisthesis is well-documented; however, there is a paucity of literature investigating facet fluid in degenerative cervical spondylolisthesis.Methods: Patients diagnosed with cervical degenerative spondylolisthesis were identified from a hospital’s medical records. Demographic and surgical characteristics were collected through a structured query language search and manual chart review. Radiographic measurements were made on preoperative MRIs for all vertebral levels diagnosed with spondylolisthesis and adjacent undiagnosed levels between C3 and C6. The facet fluid index was calculated by dividing the facet fluid measurement by the width of the facet. Bivariate analysis was conducted to compare facet characteristics based on radiographic spondylolisthesis and spondylolisthesis stability.Results: We included 154 patients, for whom 149 levels were classified as having spondylolisthesis and 206 levels did not. The average facet fluid index was significantly higher in patients with spondylolisthesis (0.26±0.07 vs. 0.23±0.08, p <0.001). In addition, both fluid width and facet width were significantly larger in patients with spondylolisthesis (p <0.001 each). Cervical levels in the fusion construct demonstrated a greater facet fluid index and were more likely to have unstable spondylolisthesis than stable spondylolisthesis (p <0.001 each).Conclusions: Facet fluid index is associated with cervical spondylolisthesis and an increased facet size and fluid width are associated with unstable spondylolisthesis. While cervical spondylolisthesis continues to be an inconclusive finding, vertebral levels with spondylolisthesis, especially the unstable ones, were more likely to be included in the fusion procedure than those without spondylolisthesis.

Optimization of a Solution-Processed SiO₂ Gate Insulator by Plasma Treatment for Zinc Oxide Thin Film Transistors

Jeong, Yesul,Pearson, Christopher,Kim, Hyun-Gwan,Park, Man-Young,Kim, Hongdoo,Do, Lee-Mi,Petty, Michael C. American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.3

<P>We report on the optimization of the plasma treatment conditions for a solution -processed silicon dioxide gate insulator for application in zinc oxide thin film transistors (TFTs). The SiO2 layer was formed by spin coating a perhydropolysilazane (PHPS) precursor. This thin film was subsequently thermally annealed, followed by exposure to an oxygen plasma, to form an insulating (leakage current density of similar to 10(-)7 A/cm(2)) SiO2 layer. Optimized ZnO TFTs (40 W plasma treatment of the gate insulator for 10 s) possessed a carrier mobility of 3.2 cm(2)/(V s), an on/off ratio of similar to 10(7), a threshold voltage of -1.3 V, and a subthreshold swing of 0.2 V/decade. In addition, long-term exposure (150 min) of the pre -annealed PHPS to the oxygen plasma enabled the maximum processing temperature to be reduced from 180 to 150 degrees C. The resulting ZnO TFT exhibited a carrier mobility of 1.3 cm(2)/(V s) and on/off ratio of similar to 10(7).</P>

Galactic Archeology with the AEGIS Survey: The Evolution of Carbon and Iron in the Galactic Halo

Yoon, Jinmi,Beers, Timothy C.,Dietz, Sarah,Lee, Young Sun,Placco, Vinicius M.,Costa, Gary Da,Keller, Stefan,Owen, Christopher I.,Sharma, Mahavir American Astronomical Society 2018 The Astrophysical journal Vol.861 No.2

<P>Understanding the evolution of carbon and iron in the Milky Way's halo is of importance because these two elements play crucial roles in constraining star formation, Galactic assembly, and chemical evolution in the early universe. Here we explore the spatial distributions of the carbonicity, [C/Fe], and metallicity, [Fe/H], of the halo system based on medium-resolution (R similar to 1300)spectroscopy of similar to 58,000 stars in the southern hemisphere from the AAOmega Evolution of Galactic Structure (AEGIS) survey. The AEGIS carbonicity map exhibits a positive gradient with distance, as similarly found for the Sloan Digital Sky Survey carbonicity map of Lee et al. The metallicity map confirms that [Fe/H] decreases with distance from the inner halo to the outer halo. We also explore the formation and chemical evolution history of the halo by considering the populations of carbon-enhanced metalpoor (CEMP) stars present in the AEGIS sample. The cumulative and differential frequency of CEMP-no stars (as classified by their characteristically lower levels of absolute carbon abundance, A(C) <= 7.1, for subgiants and giants) increases with decreasing metallicity and is substantially higher than previous determinations for CEMP stars as a whole. In contrast, that of CEMP-s stars (with higher A(C)) remains almost flat, at a value of similar to 10% in the range -4.0 less than or similar to [Fe/H] less than or similar to -2.0. The distinctly different behaviors of the CEMP-no and CEMP-s stars relieve the tension with population synthesis models assuming a binary mass-transfer origin, which previously struggled to account for the higher reported frequencies of CEMP stars, taken as a whole, at low metallicity.</P>

풍선 도뇨관을 이용한 식도 둔형 이물제거

김기운,김시영,이종서,김철,정윤석 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: In most cases of a foreign body in the esophagus, an ENT specialist is consulted, which may be time consuming if not evaluated in a timely fashion. The patients are admitted to the hospital and sent to the operating room, where they are placed under anesthesia and the object is removed by using an esophagoscope. Methods: A prospective randomized trial was conducted during the period from January 1998 to June 2000. All patients presenting to emergency department with blunt objects in the esophagus were included. In one group, with fluoroscopic guidance, a Foley catheter was placed to remove the blunt foreign bodies. And in the other group, we removed them by using the esophagoscpe. We used the t-test for statistical analysis in this study. Results: Total number of patients enrolled in this study was 38.22 patients were enrolled in the Foley Catheter removal group, and the remaining 16 were enrolled in the esophagoscope removal group. The success rate for the Foley catheter was 21/22(95.5%), and that for the esophagoscope was 15/16(93.8%). The average time of removal for the Foley catheter group was 0.70± 0.28 hours while that for the esophagoscope group was 5.96 ± 2.22 hours. One side effect, nonfatal hypoxia, was noted in the Foley catheter removal group. The average cost for the Foley catheter group were 78,800 won(approximately 600 US dollars) while that for the esophagoscope group took 722,800 won(approximately 600 US dollars). Conclusion: In our study, we found that the success rate for removing blunt foreign bodies from the esophagus by using a simple Foley catheter was high, also the Foley catheter was a time saving and cost effective procedure with an excellent safety profile.

Transient receptor potential vanilloid-1 (TRPV1) is a mediator of lung toxicity for coal fly ash particulate material.

Deering-Rice, Cassandra E,Johansen, Mark E,Roberts, Jessica K,Thomas, Karen C,Romero, Erin G,Lee, Jeewoo,Yost, Garold S,Veranth, John M,Reilly, Christopher A American Society for Pharmacology and Experimental 2012 Molecular pharmacology Vol.81 No.3

<P>Environmental particulate matter (PM) pollutants adversely affect human health, but the molecular basis is poorly understood. The ion channel transient receptor potential vanilloid-1 (TRPV1) has been implicated as a sensor for environmental PM and a mediator of adverse events in the respiratory tract. The objectives of this study were to determine whether TRPV1 can distinguish chemically and physically unique PM that represents important sources of air pollution; to elucidate the molecular basis of TRPV1 activation by PM; and to ascertain the contributions of TRPV1 to human lung cell and mouse lung tissue responses exposed to an insoluble PM agonist, coal fly ash (CFA1). The major findings of this study are that TRPV1 is activated by some, but not all of the prototype PM materials evaluated, with rank-ordered responses of CFA1 > diesel exhaust PM > crystalline silica; TRP melastatin-8 is also robustly activated by CFA1, whereas other TRP channels expressed by airway sensory neurons and lung epithelial cells that may also be activated by CFA1, including TRPs ankyrin 1 (A1), canonical 4α (C4α), M2, V2, V3, and V4, were either slightly (TRPA1) or not activated by CFA1; activation of TRPV1 by CFA1 occurs via cell surface interactions between the solid components of CFA1 and specific amino acid residues of TRPV1 that are localized in the putative pore-loop region; and activation of TRPV1 by CFA1 is not exclusive in mouse lungs but represents a pathway by which CFA1 affects the expression of selected genes in lung epithelial cells and airway tissue.</P>

A Framework of Outsourcing Decision-Making for Human Resource Information Systems

Lee, Chung-Shing,Lee, C.Christopher,Kwon, He-Boong 한국경영정보학회 2007 한국경영정보학회 학술대회논문집 Vol.2007 No.-

This paper attempts to develop a framework for interrelationships among human resources information systems (HRIS), outsourcing, and corporate culture. This research investigates impacts of outsourcing HRIS on corporate culture. In this paper, we hypothesize that outsourcing corporate HRIS is less appealing (1) if the quality of product and customer service matters for a firm, (2) if a firm is concerned with a loss of intellectual property, and (3) if a firm requires maintenance of a distinctive human resource service function that is capable of meeting the challenges of fast changing customer demands in a dynamic business environment. In addition, this study argues companies must be aware of the total costs associated with HRIS before outsourcing its human resource functions. Finally, the impact on employee morale and performance must also be considered By outsourcing HRIS, managers will be able to spend more time and resources dedicated to an employee's professional career development.

MELANOCYTOMA OF THE OPTIC DISK IN THE KOREAN POPULATION

Lee, Christopher S,Bae, Jeong H,Jeon, Ik H,BYEON, SUK H,KOH, HYOUNG J,Lee, Sung C The Ophthalmic Communications Society, Inc. 2010 Retina Vol.30 No.10

PURPOSE:: To report on the clinical features and the natural course of optic disk melanocytoma in the Korean population. METHODS:: A retrospective review of medical records was performed on 27 consecutive patients with optic disk melanocytoma. In cases with tumor enlargement, surface area and diameter of tumors were measured from fundus images using computer software. RESULTS:: The median age at diagnosis was 46 years with a slight female predominance (63%). The median tumor diameter and height were 3.1 mm and 1.9 mm, respectively. There were no cases with tumor-related visual loss for a median follow-up of 2 years. Tumor enlargement was observed in 4 of 21 patients (19%) that had follow-up of 1 year or more with no malignant transformation. The mean change of tumor surface area was 2.4 mm (52% increase), and the mean change of tumor diameter was 1.8 mm over a mean follow-up of 53 months in 4 cases with tumor growth. Only tumor vascularization on fluorescent angiography correlated with tumor growth (Log-rank test; P = 0.049). Kaplan-Meier survival estimated that the tumor growth was 0% at 1 year, 14% at 5 years, and 57% at 8 years. CONCLUSION:: Optic disk melanocytoma in the Korean population tends to be superiorly located in the optic disk, and visual prognosis was excellent. Periodic ocular examination is warranted because 57% of patients were estimated to show tumor enlargement by 8 years of follow-up.

Foreign Direct Investments in the United States : Macro-level and Microeconomic Factors 거시적 변수와 미시 경제적 변수

Lee, Hyun-Kyu,Lee, C. Christopher,Rawashdeh, Mufeed 한국경상학회, 한국국민경제학회 2003 경제연구 Vol.21 No.4

본 논문은 미국에 대한 해외 직접 투자를 설명하는데 기여할 수 있는 거시적 변수들과 미시 경제적 변수들을 연구한다. 해외 직접 투자에 관한 선행연구에 따르면, 거시적 변수들만 연구 모형에 포함시키든지, 아니면 미시 경제적 변수들만 포함시켜왔다. 본 연구는 거시적 변수와 미시 경제적 변수들을 모두 연구 모형에 포함 시켜서, 다변량 통계 분석을 통한 실증연구를 함으로서, 해외 직접 투자에 관한 연구 분야에 기여를 한다고 판단된다. 1987년부터 1995년까지의 미국에 대한 209 해외 직접 투자 사례에서 자료를 수집하였으며, 통계적으로 분석한 결과에 의하면, 개인소득이 높고, 산업 성장률이 낮으며, 정치적으로 안정된 국가의 규모가 큰 대기업이 미국에 직접 투자를 할 경향이 더 크다. 그리고 투자유형은 완전 소유자회사를 설립하기보다 합작투자를 선호하고 투자규모도 더 크게 하였음을 보여준다. This study examines the macro-level factors and microeconomic factors that contribute to the explanation of foreign direct investments in the United States (FDIUS). Prior studies have focused on either macro-level factors or microeconomic factors. This paper attempts to develop a multivariate statistical model to accomodate both macro-level and microeconomic factors. Results of analyzing 209 cases over the period from 1987 to 1995 show that FDIUS are made by large size firms coming from politically stable countries that have low industry growth rate and high personal income. The firm is more likely to choose the joint venture form of business to minimize risk.

ACLS Simulation Examination between Korean and American paramedic students

Christopher C. Lee,Tae Min Kim 한국응급구조학회 2009 한국응급구조학회지 Vol.13 No.3

AN ECONOMIC EFFECT OF THE TRANS KOREA RAILWAY

Lee, C. Christopher,Choi, Soon-Gwon,Eh, Youn-Yang 고려대학교 평화연구소 2004 평화연구 Vol.12 No.2

This paper attempts to develop an optimization mood to estimate an economic effect of the Trans Korea Railway (TKR). TKR will pass through the Korean peninsula and connect to the Euro-Asia Railroads such as the Trans Siberian Railway. A success of the TKR operations depends on a good understanding of such economic effect. Optimization can develop a quantitative model to account for the economic effect of TKR with an optimization approach. A lack of research on this subject motivates this research. First, this paper employs a mixed integer programming for an optimization modeling technique to estimate the total transport cost using TKR. Next, based on the optimization models, a new model is developed to estimate the economic effect of TKR. The proposed model will provide information that helps policy makers in North Korea, South Korea and japan reach an agreement on pricing of the TKR usage fee. A successful implementation of TKR will contribute to peace and prosperity of the Korean peninsula.