http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Myeong Jin Ko (검색결과 290 건)
- 무료
- 기관 내 무료
- 유료
-
손익부,고명진,김영섭,노영철 한국레이저가공학회 2009 한국레이저가공학회지 Vol.12 No.1
Ripple formation of femtosecond laser in stainless steel is investigated using 184 fs pulses with a center wavelength of 785 nm. The effect of the laser polarization relative to the translation direction is observed. For drilling with a certain aspect ratio, reflections at the hole walls take place, leading to a non-uniform intensity distribution deep inside the formed hole. Finally, it is shown that a circular polarization during the drilling process significantly improves the quality of the produced holes.
-
Ko, Myeong Jin,Park, Seung Won,Kim, Young Baeg The Korean Neurosurgical Society 2019 Journal of Korean neurosurgical society Vol.62 No.4
Objective : Few studies have reported direct comparative data of lumbar spine angles between direct lateral interbody fusion (DLIF) and oblique lateral interbody fusion (OLIF). The purpose of this study was to investigate the clinical and radiological outcomes of DLIF and OLIF, and determine influential factors. Methods : The same surgeon performed DLIF from May 2011 to August 2014 (n=201) and OLIF from September 2014 to September 2016 (n=142). Radiological parameters, cage height, cage angle (CA), cage width (CW), and cage location were assessed. We checked the cage location as the distance (mm) from the anterior margin of the disc space to the anterior metallic indicator of the cage in lateral images. Results : There were significant differences in intervertebral foramen height (FH; $22.0{\pm}2.4$ vs. $21.0{\pm}2.1mm$, p<0.001) and sagittal disc angle (SDA; $8.7{\pm}3.3$ vs. $11.3{\pm}3.2^{\circ}$, p<0.001) between the DLIF and OLIF groups at 7 days postoperatively. CA ($9.6{\pm}3.0$ vs. $8.1{\pm}2.9^{\circ}$, p<0.001) and CW ($21.2{\pm}1.6$ vs. $19.2{\pm}1.9mm$, p<0.001) were significantly larger in the OLIF group compared to the DLIF group. The cage location of the OLIF group was significantly more anterior than the DLIF group ($6.7{\pm}3.0$ vs. $9.1{\pm}3.6mm$, p<0.001). Cage subsidence at 1 year postoperatively was significantly worse in the DLIF group compared to the OLIF group ($1.0{\pm}1.5$ vs. $0.4{\pm}1.1mm$, p=0.001). Cage location was significantly correlated with postoperative FH (${\beta}=0.273$, p<0.001) and postoperative SDA (${\beta}=-0.358$, p<0.001). CA was significantly correlated with postoperative FH (${\beta}=-0.139$, p=0.044) and postoperative SDA (${\beta}=0.236$, p=0.001). Cage location (${\beta}=0.293$, p<0.001) and CW (${\beta}=-0.225$, p<0.001) were significantly correlated with cage subsidence. Conclusion : The cage location, CA, and CW seem to be important factors which result in the different-radiological outcomes between DLIF and OLIF.
-
-
Myeong Jin Ko 대한신경손상학회 2023 Korean Journal of Neurotrauma Vol.19 No.1
Ossification of the posterior longitudinal ligament (OPLL) caused by lamellar bone deposition of the posterior longitudinal ligament can result in severe neurological deficits due to spinal cord compression.7, 10) OPLL progresses gradually, decreasing cervical spine function and quality of life.4) Although genetic or environmental factors have been suggested as the causes of OPLL progression, its pathogenesis is unknown.1, 3, 5, 8, 9) Previous studies have reported that the relationship between OPLL progression and mobility of the cervical spine implying that abnormal strain distribution in the tensile direction affects OPLL.8) Furthermore, surgical treatment hastens OPLL progression through biological stimulation.2)
-
Ko, Myeong Jin,Park, Seung Won,Kim, Young Baeg The Korean Neurosurgical Society 2019 Journal of Korean neurosurgical society Vol.62 No.4
Objective : In an aging society, the number of patients with symptomatic degenerative spondylolisthesis (DS) is increasing and there is an emerging need for fusion surgery. However, few studies have compared transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) for the treatment of patients with DS. The purpose of this study was to investigate the clinical and radiological outcomes between TLIF and LLIF in DS. Methods : We enrolled patients with symptomatic DS at L4-5 who underwent TLIF with open pedicle screw fixation (TLIF group, n=41) or minimally invasive LLIF with percutaneous pedicle screw fixation (LLIF group, n=39) and were followed-up for more than one year. Clinical (visual analog scale and Oswestry disability index) and radiological outcomes (spondylolisthesis rate, segmental sagittal angle [SSA], mean disc height [MDH], intervertebral foramen height [FH], cage subsidence, and fusion rate) were assessed. And we assessed the changes in radiological parameters between the postoperative and the last follow-up periods. Results : Preoperative radiological parameters were not significantly different between the two groups. LLIF was significantly superior to TLIF in immediate postoperative radiological results, including reduction of spondylolisthesis rate (3.8% and 7.2%), increase in MDH (13.9 mm and 10.3 mm) and FH (21.9 mm and 19.4 mm), and correction of SSA ($18.9^{\circ}$ and $15.6^{\circ}$) (p<0.01), and the changes were more stable from the postoperative period to the last follow-up (p<0.01). Cage subsidence was observed significantly less in LLIF (n=6) than TLIF (n=21). Fusion rate was not different between the two groups. The clinical outcomes did not differ significantly at any time point between the two groups. Complications were not statistically significant. However, TLIF showed chronic mechanical problems with screw loosening in four patients and LLIF showed temporary symptoms associated with the surgical approach, such as psoas and ileus muscle symptoms in three and two cases, respectively. Conclusion : LLIF was more effective than TLIF for spondylolisthesis reduction, likely due to the higher profile cage and ligamentotactic effect. In addition, LLIF showed mechanical stability of the reduction level by using a cage with a larger footprint. Therefore, LLIF should be considered a surgical option before TLIF for patients with unstable DS.
-
IE4-class 2.2-kW Induction Motor Design and Performance Evaluation
Myeong Jin Ko,Sung-Ho Lee,Soon Sub Park 한국생산제조학회 2021 한국생산제조학회지 Vol.30 No.5
In this study, a 2.2 kW super-premium (IE4) class 4-pole three-phase induction motor was designed and developed. We compared this prototype motor with the industrial induction motors sold by leading international companies. We designed and fabricated a stator, an Al rotor, housing, bearing front and rear covers made of Al 6061, a shaft, and a cooling fan. The cooling fan produced with 3D printing technology was assembled on the unload shaft. Following motor assembly, its mechanical performance, such as noise, vibration, wind speed, and efficiency, was analyzed. Compared with the considered international-standard motors, our proposed motor showed superior performance in terms of noise, vibration, and efficiency but not in terms of air gap and wind speed.
-
Kummell’s Disease, Which Is Becoming Increasingly Important In An Aging Society: A Review
Myeong Jin Ko,Byung-Jou Lee 대한신경손상학회 2023 Korean Journal of Neurotrauma Vol.19 No.1
Kummell’s disease (KD) is referred to as delayed posttraumatic vertebral collapse, avascular necrosis of vertebrae, or ischemic vertebral collapse. KD is no longer rare in an aging society. It is mainly caused by minor trauma, and nonunion occurs secondary to avascular necrosis at the vertebral body fracture site, which can lead to vertebral kyphosis or intravertebral instability. Clinical symptoms of KD range from no symptoms to severe paralysis due to nerve injury. KD is considered a complication of osteoporotic vertebral compression fractures, and conservative treatment, including osteoporosis treatment, is important. Timely interventions such as vertebral augmentation or surgery, with active regular follow-up are necessary before the onset of neurological deficits due to osteonecrotic collapse in patients with suspected KD. In this study, we summarize the pathogenesis, diagnosis, and treatment of KD, which is showing increasing prevalence in an aging society. We have presented a literature review and discussed clinical guidelines and therapeutic strategies to reduce the morbidity and mortality associated with KD.
-
CASE REPORT : Primary Malignant Lymphoma of the Cranial Vault with Extra-and Intracranial Extension
( Myeong Jin Ko ),( Sung Nam Hwang ),( Yong Sook Park ),( Teak Kyun Nam ) 대한뇌종양학회 대한신경종양학회 2013 Brain Tumor Research and Treatment Vol.1 No.1
Bone involvement is a common finding in many types of lymphomas, particularly in advanced stages. However, cranial vault affliction has been regarded as an exceedingly rare presentation. Here, we report the case of a patient with cranial vault lymphoma who presented with a scalp mass. An 81-yearold woman presented with a gradually growing and non-painful frontal scalp mass that she noticed one month before admission. It was a flatly elevated, round mass measuring about 6×4×4 cm. Computed tomography and magnetic resonance imaging of the brain revealed a contrast-enhancing intracranial extradural mass at the counter-location of the scalp mass. The superior sagittal sinus was involved at the tumor site. Cerebral angiography showed that the tumor feeding vessels originated from the bilateral external carotid arteries. An operation was performed and the tumors were removed together with the involved bone. The pathologic diagnosis was malignant diffuse large B-cell type lymphoma. The patient was transferred to the Hemato-Oncology department for chemotherapy. Primary lymphoma of the cranial vault with scalp mass is very rare but it should be considered in the differential diagnosis of scalp masses. Although the results of reported cases are variable, the combination of surgery, radiation, and chemotherapy appears to offer favorable outcomes.
-
( Myeong Jae Yoon ),( Ji Ae Yang ),( Sang Hyun Joo ),( Sang Jin Lee ),( Hyun Mi Kwon ),( Dong Jin Ko ),( Jin Young Moon ),( Yeong Wook Song ),( Eun Bong Lee ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1
Background: Gout is a recurrent infi ammatory arthritis caused by monosodium urate, which can be prevented urate-lowering agents such as allopurinol. However, gout attack can still recur during urate-lowering therapy. In this study we investigated the risk factors associated with recurrence of gout attacks during allopurinol treatment. Methods: A total of 527 gout patients were enrolled, who took allopurinol at least for 6 months at Seoul National University Hospital between March 2001 and March 2013. The patients were divided into those who have ever experienced recurrence of gout attack (recurrence group) and those who haven`t (non-recurrence group) during allopurinol treatment. To reveal the risk factors for gout recurrence, we compared baseline characteristics, concomitant diseases, uric acid level, creatinine level, presence of tophi and type of prophylaxis. Results: The mean age of the enrolled patients was 58.7 years and 96.2% were male. The patients were followed-up for mean duration of 3.17 years. During urate-lowering therapy, 323 patients (61.3%) experienced recurrence of gout attack. In recurrence group, baseline uric acid level was signifi cantly higher than non-recurrence group (8.6 2.0 vs 8.1 1.9 mg/dL, p=0.0043). The presence of tophi was more commonly observed in recurrence group, too (29.4% vs 18.6%, p=0.006). The other variables showed no difference between two groups, which include age, sex, concomitant diseases, the presence of urinary stone, the type of prophylaxis treatment and initial creatinine level. In multivariate logistic regression analysis, high uric acid level (>8.5mg/dl) and the presence of tophi were found to be risk factors for gout attack during allopurinol treatment. Conclusion: Our study revealed that patients who show uric acid level > 8.5 mg/ dL and/or tophi at baseline have higher risk for recurrence of gout attack during allopurinol treatment. Education and closer follow-up will be required for those risky patients.
-
RISS
스콜라연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
