• Journal of Korean Neurosurgical Society
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• 제51권1호
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• pp.20-23
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• 2012

Objective : To compare radiographic analysis on the sagittal lumbar curve when standing, sitting on a chair, and sitting on the floor. Methods : Thirty asymptomatic volunteers without a history of spinal pathology were recruited. The study population comprised 11 women and 19 men with a mean age of 29.8 years. An independent observer assessed whole lumbar lordosis (WL) and segmental lordosis (SL) between L1 and S1 using the Cobb's angle on lateral radiographs of the lumbar spine obtained from normal individuals when standing, sitting on a chair, and sitting on the floor. WL and SL at each segment were compared for each position. Results : WL when sitting on the floor was reduced by 72.9% than the average of that in the standing position. Of the total decrease in WL, 78% occurred between L4 to S1. There were significant decreases in SL at all lumbar spinal levels, except L1-2, when sitting on the floor as compared to when standing and sitting on a chair. Changes in WL between the positions when sitting on a chair and when sitting on the floor were mostly contributed by the loss of SL at the L4-5 and L5-S1 levels. Conclusion : When sitting on the floor, WL is relatively low; this is mostly because of decreasing lordosis at the L4-5 and L5-S1 levels. In the case of lower lumbar fusion, hyperflexion is expected at the adjacent segment when sitting on the floor. To avoid this, sitting with a lordotic lumbar curve is important. Surgeons should remember to create sufficient lordosis when performing lower lumbar fusion surgery in patients with an oriental life style.

• 한국약용작물학회지
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• 제4권2호
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• pp.132-138
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• 1996

패모의 기내 주년 생산 체계를 확립하기 위한 연구의 일환으로 cytokinin이 첨가된 배치에서 배양 방법의 차이가 자구 형성과 비대에 미치는 영향, 배지의 삼투 포텐셜 조절을 위한 mannitol 첨가나 활성 탄소 및 생장 억제제 처리가 기관 형성과 인편 비대에 미치는 영향에 대해서 실험한 결과는 다음과 같다. 1. 0mg/L kinetin과 0. 3mg/L NAA가 혼용 처리된 MS 고체 배지에서 액체 배지나 액체 현탁배지에서보다 효과적인 자구 생장과 증식율을 나타냈으며, 액체 배지나 액체 현탁처리 배지에서는 비슷한 결과를 나타냈다. 활성 탄소의 농도는 $0.01%{\sim}0.1%$ 처리구에서 형성된 자구의 비대가 양호하였고, 0. 5% 이상 농도에서는 오히려 생장이 억제되었다. $1{\sim}2%$ mannitol이 첨가된 배지에서 인편으로부터의 자구 형성수 및 구비대가 양호하였으며, 그 이상의 농도에서는 생장에 저해적으로 작용하였다. 생장 억제제인 B-9과 Chloromequat 처리구에서는 $10{\sim}100mg/L$ 처리구에서 자구 발생 및 비대가 양호하였으나, 발생 인편의 생육 상태가 억제되었으며, ABA 처리구에서는 배양 중 인편이 모두 고사하였다.

• 원예과학기술지
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• 제17권6호
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• pp.765-767
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• 1999

안개초 잎조직의 재분화는 TDZ가 BA와 kinetin에 비하여 월등히 효과적이었고 TDZ $3.0mg{\cdot}L^{-1}$에서 가장 높은 재분화율을 보였다. 한편 BA처리에서는 투명묘 발생율이 높았고 kinetin은 재분화에 영향을 주지 못하였다. NAA와 IAA의 비교에서 IAA $0.3mg{\cdot}L^{-1}$를 첨가한 배지에서 재분화율과 잎당 부정아수가 많았다. Agar 농도에 따른 잎조직의 재분화는 1.0, 1.2 및 1.6%에서 야기되었다. 배양초기 10일간의 암처리는 재분화율을 75%까지 증가시켰다. 생장점배양 후 3회 계대배양한 묘에서 채취한 잎 절편에서 재분화율이 84%로 가장 높았고 잎당 부정아수도 6.8개로 가장 많았다.

• Journal of Korean Neurosurgical Society
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• 제62권5호
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• pp.603-609
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• 2019

Objective : The purpose of this retrospective study was to determine which of the proximal adjacent segment disease (ASD) and distal ASD was more prevalent and what parameters is more related to ASD in proximal levels and distal levels after more than 2 levels fusions. Methods : The medical records were reviewed retrospectively for 856 cases. A total of 66 cases of ASD were enrolled. On preop magnetic resonance imaging, disc degeneration was measured at the upper and lower parts of surgically treated levels and confirmed by the commonly used Pfirrmann grade. Segmental flexibility in sagittal plane was embodied in segment range of motion (ROM) obtained through flexion and extension X-ray before surgery. Coronal angle was recorded as methods Cobb's angle including fusion levels preoperatively. For the comparison of categorical variables between two independent groups, the chi-square test and Fisher exact test were performed. Results : Proximal ASD and distal ASD were 37/856 (4.32%) and 29/856 (3.39%), respectively. The incidence of proximal ASD was relatively high but insignificant differences. In comparison between ASD group and non ASD group, proximal Pfirmman was higher in proximal ASD and distal Pfirmman was higher in distal ASD group (p=0.005, p<0.008, respectively). However, in the ROM, proximal ROM was higher in proximal ASD, but distal ROM was not different between the two groups (p<0.0001, p=0.995, respectively). Coronal angle was not quite different in both groups (p=0.846). Conclusion : In spite of higher frequency in ASD in proximal level in spinal fusion, it is not clear that incidence of ASD in proximal level is not higher than that of distal ASD group in more than 2 level thoracolumbar fusions. Not only Pfirrmann grade but also proximal segmental ROM is risk factor for predicting the occurrence of ASD in patients more than 2 level of thoracolumbar spine fusion operation excluding L5S1.

• 한국정밀공학회지
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• 제23권4호
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• pp.176-182
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• 2006

Although several artificial disc designs have been developed for the treatment of discogenic low back pain, biomechanical changes with its implantation were rarely studied. To evaluate the effect of artificial disc implantation on the biomechanics of functional spinal unit, a nonlinear three-dimensional finite element model of L4-L5 was developed with 1-mm CT scan data. Biomechanical analysis was performed for two different types of artificial disc having constrained and unconstrained instant center of rotation(ICR), ProDisc and SB Charite III model. The implanted model predictions were compared with that of intact model. Angular motion of vertebral body, forces on the spinal ligaments and facet joint, and stress distribution of vertebral endplate for flexion-extension, lateral bending, and axial rotation with a compressive preload of 400N were compared. The implanted model showed increased flexion-extension range of motion compared to that of intact model. Under 6Nm moment, the range of motion were 140%, 170% and 200% of intact in SB Charite III model and 133%, 137%, and 138% in ProDisc model. The increased stress distribution on vertebral endplate for implanted cases could be able to explain the heterotopic ossification around vertebral body in clinical observation. As a result of this study, it is obvious that implanted segment with artificial disc suffers from increased motion and stress that can result in accelerated degenerated change of surrounding structure. Unconstrained ICR model showed increased in motion but less stress in the implanted segment than constrained model.

• Journal of Korean Neurosurgical Society
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• 제46권4호
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• pp.285-291
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• 2009

Objective : This study examined the change of range of motion (ROM) at the segments within the dynamic posterior stabilization, segments above and below the system, the clinical course and analyzed the factors influencing them. Methods : This study included a consecutive 27 patients who underwent one-level to three-level dynamic stabilization with Bioflex system at our institute. All of these patients with degenerative disc disease underwent decompressive laminectomy with/without discectomy and dynamic stabilization with Bioflex system at the laminectomy level without fusion. Visual analogue scale (VAS) scores for back and leg pain, whole lumbar lordosis (from L1 to S1), ROMs from preoperative, immediate postoperative, 1.5, 3, 6, 12 months at whole lumbar (from L1 to S1), each instrumented levels, and one segment above and below this instrumentation were evaluated. Results : VAS scores for leg and back pain decreased significantly throughout the whole study period. Whole lumbar lordosis remained within preoperative range, ROM of whole lumbar and instrumented levels showed a significant decrease. ROM of one level upper and lower to the instrumentation increased, but statistically invalid. There were also 5 cases of complications related with the fixation system. Conclusion : Bioflex posterior dynamic stabilization system supports operation-induced unstable, destroyed segments and assists in physiological motion and stabilization at the instrumented level, decrease back and leg pain, maintain preoperative lumbar lordotic angle and reduce ROM of whole lumbar and instrumented segments. Prevention of adjacent segment degeneration and complication rates are something to be reconsidered through longer follow up period.

• Journal of Trauma and Injury
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• 제35권1호
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• pp.12-18
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• 2022

Purpose: Pedicle screw fixation provides 3-column stabilization, multidimensional control, and a higher rate of interbody fusion. Although computed tomography (CT) is recommended for the postoperative assessment of pedicle screw fixation, its use is limited due to the radiation exposure dose. The purpose of this preliminary retrospective study was to assess the clinical usefulness of low-dose mobile cone-beam CT (CBCT) for the postoperative evaluation of pedicle screw fixation. Methods: The author retrospectively reviewed postoperative mobile CBCT images of 15 patients who underwent posterior pedicle screw fixation for spinal disease from November 2019 to April 2020. Pedicle screw placement was assessed for breaches of the bony structures. The breaches were graded based on the Heary classification. Results: The patients included 11 men and four women, and their mean age was 66±12 years. Of the 122 pedicle screws, 34 (27.9%) were inserted in the thoracic segment (from T7 to T12), 82 (67.2%) in the lumbar segment (from L1 to L5), and six (4.9%) in the first sacral segment. Although there were metal-related artifacts, the image of the screw position (according to Heary classification) after surgery could be assessed using mobile CBCT at all levels (T7-S1). Conclusions: Mobile CBCT was accurate in determining the location and integrity of the pedicle screw and identifying the surrounding bony structures. In the postoperative setting, mobile CBCT can be used as a primary modality for assessing the accuracy of pedicle screw fixation and detecting postoperative complications.

• 대한음성학회지:말소리
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• 제37호
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• pp.1-12
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• 1999

In this paper, we examine the allophones of an underlying segment /l/ in Korean dialects. In particular, we examine how an underlying /l/ sound surfaces in the Korean dialect spoken at Yonbyon, China. To do so, we employ the following processes: First, we perform the phonetic studies on the allophones of an underlying /l/ in the Yonbyon dialect. Secondly, we compare the phonological environments of the allophones of an underlying /l/ in the Yonbyon dialect with the South Korean dialect. Finally, we discuss the phonological implications of the allophones of the underlying /l/ in terms of Feature Geometry and Syllable Contact Law. Based on the phonetic study, we will argue that the distinctive feature [sonorant] should be placed outside the root node and that the flap, an allophone of an underlying /l/, should be understood as an obstruent, not a sonorant.

• Biomolecules & Therapeutics
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• 제2권2호
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• pp.131-135
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• 1994

The effect of ginsenoside (GS) from Panax ginseng on basal and nitro-L-arginine suppressed nitric oxide (NO) production was studied in rat kidney. NO production was determined by conversion to [$^{14C}$]=L-citrulline from [$^{14C}$]-L-arginine both in whole kidney and three renal segments; glomerulus, cortex excluding glomerulus (cortex-) and medulla. Nitro-L-arginine (total dose of 30 mg/kg/3 days, i.p.) significantly reduced NO production in whole kidney, which was prevented by GS pretreatment (30 mg/kg/3 days, i.p.). Relative high dose of GS (120 mg/kg/4 days, i.p..) selectively increased NO production in glomerulus and cortex-. Protein content, on wet weight basis, in cortex- and glomerular DNA content were significantly reduced by GS. Our results confirm the existence of constitutive nitric oxide synthase in kidney and it seems that target nephron segment for volume expansion due to GS'NO-mediated vasodilation and for NO production stimulated by GS is cortex including glomerulus.lus.

• Asia Marketing Journal
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• 제21권2호
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• pp.51-71
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• 2019

L&P Cosmetic, the leading company selling mask packs on the global market, produces MEDIHEAL, the number-one best-selling mask pack brand in Korea and the best-selling imported mask pack brand in China (2017). The company pioneered the premium market for mask packs through its launch of premium mask packs in 2009, and has subsequently achieved outstanding success in Korea and China. Three key factors have contributed to the success of L&P Cosmetic: product leadership with R&D capability, strategic marketing programs tailored for each market segment, and operational excellence focusing on strategic outsourcing and partnership management. Nonetheless, globalization beyond the Chinese market remains a major challenge for the potential of L&P Cosmetic. The company has embarked upon a collaboration with BTS, the world's top K-pop stars, as an optimally effective way to achieve its goals and a highly efficient strategy to manage the risks of globalization. The global branding collaboration project with BTS has succeeded in generating primary demand for mask packs on the global market, spreading brand awareness of MEDIHEAL, and establishing global channel networks. L&P Cosmetic will continue to grow worldwide on the basis of this outstanding performance.