• Journal of Korean Neurosurgical Society
• /
• 제59권5호
• /
• pp.471-477
• /
• 2016

Objectives : The correction of clinical and radiologic abnormalities in patients with symptomatic ossification of the posterior longitudinal ligament (OPLL) is the current mainstay of treatment. This study aimed to identify radiographic predictors of severity of myelopathy in patients with symptomatic OPLL. Methods : Fifty patients with symptomatic cervical OPLL were enrolled. Based on Japanese Orthopedic Association (JOA) scores, patients were divided into either the mild myelopathy (n=31) or severe myelopathy (n=19) group. All subjects underwent preoperative plain cervical roentgenogram, computed tomography (CT), and MR imaging (MRI). Radiological parameters (C2-7 sagittal vertical axis, SVA; C2-7 Cobb angle; C2-7 range of motion, ROM; OPLL occupying ratio; and compression angle) were compared. Compression angle of OPLL was defined as the angle between the cranial and caudal surfaces of OPLL at the maximum level of cord compression Results : The occupying ratio of the spinal canal, C2-7 Cobb angle, C2-7 SVA, types of OPLL, and C2-7 ROM of the cervical spine were not statistically different between the two groups. However, the OPLL compression angle was significantly greater (p=0.003) in the severe myelopathy group than in the mild myelopathy group and was inversely correlated with JOA score (r=-0.533, p<0.01). Furthermore, multivariate regression analysis demonstrated that the compression angle (B=-0.069, p<0.001) was significantly associated with JOA scores (R=0.647, p<0.005). Conclusion : Higher compression angles of OPLL have deleterious effects on the spinal cord and decrease preoperative JOA scores.

• Journal of Korean Neurosurgical Society
• /
• 제53권6호
• /
• pp.356-369
• /
• 2013

Objective : We performed a retrospective analysis of medical records and radiographic images of patients who never underwent spinal treatment including diagnosis. The objective of this study is to explain the biomechanical and physiologic characteristics of cervical alignment related to thoracic inlet angle including T1 slope changes in each individual. Methods : We reviewed the cervical CT radiographs of 80 patients who visited ENT outpatient clinic without any symptom, diagnosis and treatment of cervical spine from January 2011 to September 2012. All targeted people were randomized without any prejudice. We assessed the data-T1 slope, Cobb's angle C2-7, neck tilt, sagittal vertical axis (SVA) C2-7 and thoracic inlet angle by the CT radiographs. Results : The relationships between each value were analyzed and we concluded that Cobb's angle C2-7 gets higher as the T1 slope gets higher, while the SVA C2-7 value decreases. Conclusion : We propose that the T1 slope is background information in deciding how much angle can be made in the cervical spinal angle of surgical lordotic curvature, especially severe cervical deformity.

• Journal of Korean Neurosurgical Society
• /
• 제60권5호
• /
• pp.567-576
• /
• 2017

Objective : Preoperative parameters including the T1 slope (T1S) and C2-C7 sagittal vertical axis (SVA) have been recognized as predictors of kyphosis after laminoplasty, which is accompanied by posterior neck muscle damage. The importance of preoperative parameters has been under-estimated in anterior cervical discectomy and fusion (ACDF) because there is no posterior neck muscle damage. We aimed to determine whether postoperative subsidence and pseudarthrosis could be predicted according to specific parameters on preoperative plain radiographs. Methods : We retrospectively analyzed 41 consecutive patients (male : female, 22 : 19; mean age, $51.15{\pm}9.25years$) who underwent ACDF with a stand-alone polyether-ether-ketone (PEEK) cage (>1 year follow-up). Parameters including SVA, T1S, segmental angle and range of motion (ROM), C2-C7 cervical angle and ROM, and segmental inter-spinous distance were measured on preoperative plain radiographs. Risk factors of subsidence and pseudarthrosis were determined using multivariate logistic regression. Results : Fifty-five segments (27 single-segment and 14 two-segment fusions) were included. The subsidence and pseudarthrosis rates based on the number of segments were 36.4% and 29.1%, respectively. Demographic data and fusion level were unrelated to subsidence. A greater T1S was associated with a lower risk of subsidence (p=0.017, odds ratio=0.206). A cutoff value of T1S<$28^{\circ}$ significantly predicted subsidence (sensitivity : 70%, specificity : 68.6%). There were no preoperative predictors of pseudarthrosis except old age. Conclusion : A lower T1S (T1S<$28^{\circ}$) could be a risk factor of subsidence following ACDF. Surgeons need to be aware of this risk factor and should consider various supportive procedures to reduce the subsidence rates for such cases.

• Journal of Korean Neurosurgical Society
• /
• 제64권6호
• /
• pp.901-912
• /
• 2021

Objective : In the cervical spine, many surgical procedures have been developed to achieve optimal results for various disorders, including degenerative diseases, traumatic injury, and tumor. In this study, we report our experience and follow-up results with a new surgical technique for cervical spine entitled posterior floating laminotomy (PFL) in comparison with conventional laminectomy and fusion (LF). Methods : Data for 85 patients who underwent conventional LF (n=66) or PFL (n=19) for cervical spine disorders between 2012 and 2019 were analyzed. Radiological parameters, including cervical lordosis (CL), T1 slope (T1S), segmental lordosis (SL), and C2-7 sagittal vertical axis (SVA), were measured with lateral spine X-rays. Functional outcomes, comprising the modified Japanese Orthopaedic Association (mJOA), neck disability index (NDI), and visual analog scale (VAS) scores, were also measured. For the patients who underwent PFL, postoperative magnetic resonance image (MRI) was performed in a month after the surgery, and the degree of decompression was evaluated at the T2-weighted axial image, and postoperative computed tomography (CT) was conducted immediately and 1 year after the operation to evaluate the gutter fusion. Results : There was no difference in CL, T1S, SL, and C2-7 SVA between the groups but there was a difference in the preoperative and postoperative SL angles. The mean difference in the preoperative SL angle compared with that at the last follow-up was -0.3° after conventional LF and 4.7° after PFL (p=0.04), respectively. mJOA, NDI, and VAS scores showed significant improvements (p<0.05) during follow-up in both groups. In the PFL group, postoperative MRI showed sufficient decompression and postoperative CT revealed gutter fusion at 1 year after the operation. Conclusion : PFL is a safe surgical method which can preserve postoperative CL and achieve good clinical outcomes.

• 식물병연구
• /
• 제30권2호
• /
• pp.131-138
• /
• 2024

당근검은잎마름병을 일으키는 A. dauci의 포자 생장 시기에 따른 chlorothalonil, dithianon, folpet, iminoctadine trisalbesilate, fluazinam의 효과를 포자 생존 검정법과 한천희석법으로 검정하였다. 포자 생존 검정법과 한천희석법으로 조사한 A. dauci CDSGM2-5를 비롯한 7개 균주의 chlorothalonil 에 대한 평균 EC₅₀값은 14.21 ㎍/ml와 100 ㎍/ml 이상이었다. Dithianon과 folpet 역시 포자 생존 검정법의 EC₅₀값이 한천희석법보다 낮았지만, iminoctadine tris-albesilate는 한천희석법으로 조사한 EC₅₀값이 더 낮았다. Fluazinam은 포자 생존 검정법과 한천희석법의 EC₅₀값이 각각 1.63 ㎍/ml와 2.40 ㎍/ml로, 두 방법의 EC₅₀값이 비슷하였다. A. dauci KACC 42997의 포자생장 단계에 따라 각 살균제를 처리한 결과, chlorothalonil, dithianon, folpet은 포자가 발아한 이후에 처리하면 발아하기 전에 처리하였을 때보다 효과가 감소하였으나, iminoctadine trisalbesilate는 포자 접종과 동시에 처리하였을 때 10.28 ㎍/ml였던 EC₅₀값이 포자가 발아한 후에 처리하면 2.68 ㎍/ml에서 3.21㎍/ml까지 감소하여, 포자 발아 후에 처리하였을 때 효과가 우수하였다. Fluazinam은 접종하는 포자에서 발아관이 장경보다 길게 발아한 포자까지 처리하여도 포자의 생장을 크게 억제하였다. 하지만 iminoctadine tris-albesilate와 fluazinam을 12시간을 배양한 후에 처리하면 EC₅₀값이 8.87 ㎍/ml와 20.65 ㎍/ml로 상승하면서 억제 효과가 감소하였다. 본 연구 결과는 살균제의 적합한 처리 시기는 병원균의 포자 생장 시기에 따라서 달라짐을 보여주고 있다. 따라서 살균제 처리 시기의 결정은 병원균의 생장 시기에 대한 살균제의 효과까지도 고려해야 할 것으로 생각되어진다.

• Journal of Korean Neurosurgical Society
• /
• 제63권1호
• /
• pp.99-107
• /
• 2020

Objective : The purpose of this study was to report the results of pedicle subtraction osteotomy (PSO) for fixed sagittal imbalance with a minimum 2-year follow-up. Besides, authors evaluated the effect of adjunctive multi-level posterior column osteotomy (PCO) on achievement of additional lumbar lordosis (LL) during PSO. Methods : A total of 31 consecutive patients undergoing PSO for fixed sagittal imbalance were enrolled and analyzed. Correction angle of osteotomized vertebra (PSO angle) and other radiographic parameters including pelvic incidence (PI), thoracic kyphosis, LL, and sagittal vertical axis (SVA) were evaluated. Clinical outcomes and surgical complications were also assessed. Results : The mean age was 66.0±9.3 years with a mean follow-up period of 33.2±10.5 months. The mean number of fused segments was 9.6±3.5. The mean operative time and surgical bleeding were 475.9±160.5 minutes and 1406.1±932.1 mL, respectively. The preoperative SRS-22 score was 2.3±0.7 and improved to 3.2±0.8 at the final follow-up. The mean PI was 54.5±9.5°. LL was changed from 7.0±28.9° to -50.2±13.2°. The PSO angle was 33.7±13.5° (15.6±20.1° preoperatively, -16.1±19.4° postoperatively). The difference of correction angle of LL (57.3°) was greater about 23.6° than which of PSO angle (33.7°). SVA was improved from 189.5±93.0 mm, preoperatively to 12.4±40.8 mm, postoperatively. There occurred six, eight, and 14 cases of complications at intraoperative, early (<2 weeks) postoperative, and late (≥2 weeks) postoperative period, respectively. Additional operations were needed in nine patients due to the complications. Conclusion : PSO could provide satisfactory results for patients with fixed sagittal imbalance regarding clinical and radiographic outcomes. Additional correction of LL could be achieved with conduction of adjunctive multi-level PCOs during PSO.

• 한국전산유체공학회지
• /
• 제21권2호
• /
• pp.62-69
• /
• 2016

It has been highly demanded to improve the accuracy of CFD(Computational Fluid Dynamics) methods for the assessment of the hydrodynamic performance of marine propellers in cavitating and non-cavitating flows. This paper presents a validation study on the numerical simulation of the tip vortex flow of a non-cavitating marine propeller SVA VP1304. The calculations are carried out by using the Reynolds averaged Navier-Stokes(RANS) approach, where the Reynolds Stress Model(RSM) is used for turbulence closure. The present paper contains a grid dependence test for the propeller open water simulations and a special emphasis is placed on conducting a local grid adaptation on the blade tip and in the tip vortex to reasonably reproduce the velocity and the pressure in the tip vortex flow field. The numerical results are compared with the experimental validation data, which are published in the second International Symposium on Marine Propulsors 2011(SMP'11). The present numerical results show a reasonable agreement with the experiments.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
• /
• pp.290-293
• /
• 2007

The land surface temperature (LST) derived from the meteorological satellite can be used to investigate the urban heat island (UHI) and its temporal variations. In this study, we developed LST retrieval algorithm from MTSAT-1R by means of a statistical regression analysis from radiative transfer simulations using MODTRAN 4 for a wide range of atmospheric, satellite viewing angle (SVA) and lapse rate conditions. 535 sets of thermodynamic initial guess retrieval (TIGR) were used for the radiative transfer simulations. Sensitivity and intercomparison results showed that the algorithm, developed in this study, estimated the LST with a similar bias and root mean square errors to that of other algorithms. The magnitude, spatial extent, and seasonal and diurnal variations of the UBI of Korean peninsula were well demonstrated by the LST derived from MTSAT-1R data. In general, the temporal variations of UHI clearly depend on the weather conditions and geographic environment of urban.

• 한국안전학회지
• /
• 제27권3호
• /
• pp.77-82
• /
• 2012

The leakage of toxic chemicals impact seriously on human being and environment, therefore during their treatment process, a proper management system is necessary to control their toxic effect. This study was designed to suggest the management regulation that supports business managers and facilities management. There are no extra regulation to control emergency accidents and terrors in chemical facilities. Developed countries like USA operate the management standards to control the toxic chemical and facilities according to their toxicity and processes. In order to solve this problem, we have analysed the advanced nations standard methods of security in chemical plants to study the new security management regulation which helps to prevent the chemical accidents. Especially, in USA, CCPS (Center for Chemical Process Safety), SVA (Security Vulnerability Assessment) and RBPSs (Risk-Based Performance Standards) of DHS (Department of Homeland Security) were invest I gated. On the basis of the results, we have suggested the application methods of the security and safety regulation in Korea.

• 대한한의진단학회지
• /
• 제13권2호
• /
• pp.129-139
• /
• 2009

Sagittal spinal balance means standing postural balance at sagittal plane. Postural imbalance with displacement of the patient's center of gravity can cause chronic back pain and ambulatory difficulty. The sagittal spinal balance is determined based on the deviation of the C7 plumb line, originating at the middle of the C7 vertebral body, from the posterior superior endplate of S1. The line is called as sagittal vertical axis (SVA). In the traditional Korean medicine, the meridian sinews, which are the most superficial pathways of the meridian system, associated with movement, muscle balance and defense. They too are separate from the main meridians, though they intersect the main meridians. Some creative and pioneer researchers in Korea thought that the anatomy trains, which suggested by Myers is a concept familiar to the meridian sinews. A reciprocal relationship between the superficial back line and the superficial front line used to be compared to the rigging of a sailboat. Therefore, We suggest that spine may be compared to a mast of the sailboat and that the sagittal spinal balance can be maintained with systemic reciprocal interacts between the front line muscles and the back.