초음파 모터의 위상차 조절과 위상차-주파수 다중 조절에 따른 속도 특성

김동옥,김원배,오금곤,최한수,김영동 조선대학교 에너지.자원신기술연구소 2003 에너지·자원신기술연구소 논문지 Vol.25 No.2

To control the position, velocity and torque of the ultrasonic motor, a great variety of method are proposed such as the amplitude, phase difference, frequency and so on. In the case of phase difference method, it has some advantages; it can control the direction and velocity of rotation only adjusting the phase difference and it has wide control-band. During the USM driving on adjusting phase difference, its characteristic was transformed by the change of resonance-frequency of stator, which means that the resonance frequency is different according to the phase difference. Consequently, we need to set up the most suitable driving frequency according to each phase difference.

임신 40주와 출산 후 6주에 있는 20대 임산부 보행의 역학적 특성 비교

윤희중,문동안,정남주,금명숙,이경식,유실,김영란,한윤수 한국운동역학회 2000 한국운동역학회지 Vol.10 No.1

본 연구는 임신 40주와 출산후 6주간에 있는 임산부의 보행 동작의 특정을 규명함으로써 이와 관련된 연구자들에게 기초자료를 제공하고자 실시하였다. 이를 위해 임신 4주에 있는 임산부를 대상으로 1차 실험을 실시하였으며 동일한 대상자를 출산후 6주에 2차로 실험하여 자료를 수집하였다. 디지타이징 시 오차를 최소화하고 인체관절점의 분별을 위해 21개의 반사마커를 부착하였다. 10m의 보행주로를 걷는 동안 두 대의 비디오카메라를 이용하여60Hz로 자료를 수집하였으며 동시에 100Hz 지면반력자료를 수집하였다.수집되어진 자료는 DLT 방법을 사용하여 분석하였으며 이의 분석에 Kwon3d 프로그램을 활용하였다. 분석결과 다음과 같은 결론을 얻었다. 1. 임신 40주와 출산 후 6주의 보행 시 지지시간과 스윙시간의 비율이 다르게 나타났으며 보폭과 보간, 활보장은 임신 40주에서 더 큰 값을 보였다. 상체 전경각 역시 임신 40주에서 더 큰 값을 보였다. 힙관절, 무릎관절, 발목관절각도는 S1이 출산후 6주에서 큰 값을 보인반면 S2는 출산전후에 큰 변화를 보이지 않다. 2. 상하지면반력의 경우 FP1과 FP2는 임신 40주보다는 출산 6주에서 큰값을 보였지만 FP3는 임신 40주에서 보다 큰값을 보이고 있었다. 전후지면반력의 경우 출산전과 후 모두 Fy2에서 보다 큰 값을 보이고 있었다. This Study was to investigate kinematical characteristic comparison of the gait pregnant 40weeks and after delivery 6weeks 20´s women and provide the basic data. To accomplish this study, in the first, carry out an experiment with the pregnant women in the pregnant 40weeks on the videotape, and than the second, make an experiment with the kinematic data. Kinematic data were filtered with a low-pass, fourth-order Butterworth filter with an effective cut off frequency of 6Hz. The conclusions were drawn as follows; 1. Floor contact Periods(stance and swing rate) were differed from before and after the delivery and a pregnant 40 weeks was greater than after delivery 6 weeks in the step, width, stride. Also, a pregnant 40 weeks was greater than after delivery 6 weeks in the front angular. And the other angular components were represented similar pattern. 2. In the vertical load, delivery 6 weeks was grater than a pregnant 40 weeks in the FP1(first peak) and FP2(valley). And FP3(second peak)was represent that a pregnant 40 weeks was greater than delivery 6 weeks. Also, in the horizontal shear, Fy2(progressional force)was greater than Fy1(breaking force) about time of the delivery.

유방암 환자의 액와 림프절 전이에 대한 수술 전 초음파 검사의 진단 유용성

한동일 ( Dong Il Han ),곽금희 ( Geum Hee Gwak ),한세환 ( Se Hwan Han ),조현진 ( Hyun Jin Cho ),양근호 ( Geun Ho Yang ),배병노 ( Byung Noe Bae ),김기환 ( Ki Hwan Kim ),김지영 ( Ji Young Kim ),박경미 ( Kyeong Mee Park ) 대한임상종양학회 2011 Korean Journal of Clinical Oncology Vol.7 No.1

연구의 목적: 유방암 환자에서 액와 림프절 전이를 평가하는데 있어 수술 전 초음파 검사의 진단적 가치를 알아보고자 하였다. 대상 및 방법: 2008년 1월부터 2010년 12월까지 3년 동안 인제 대학교 상계백병원 외과에서 유방암으로 수술 받은 환자 중에 수술 전 진단을 위해 초음파를 시행한 226명의 환자들을 대상으로 하였다. 수술 전 초음파검사결과에서 액와 림프절 전이 유무와 추후 실시된 절제 생검에 의한 액와 림프절 전이의 조직학적 검사결과를 비교하여 수술 전 초음파에 의한 액와 림프절 전이의 진단적 가치를 분석하였다. 결과: 수술 전 초음파 검사 액와 림프절 전이 유무의 민감도는 81.3%, 특이도는 77.5%였고 위양성률은 10.7%, 위음성률은 35.8%, 정확도 78.8% 였다. 수술 전 초음파 검사 액와 림프절 전이 유무와 수술 후 조직학적 액와 림프절 전이 유무의 단변량 및 다변량 검사에서 종양의 크기가 (p-value<0.001) 유일하게 통계학적으로 유의한 인자로 나타났다. 결론: 수술 전 초음파 검사 결과의 액와 림프절 전이 유무와 조직학적 검사결과의 액와 림프절 전이 사이의 상관 관계는 통계학적으로 유의한 결과를 보여 유방암의 액와 림프절 전이의 선별검사로서는 가치가 있는 것으로 생각된다. 그러나 초음파 검사를 통한 유방암 환자의 액와 림프절 전이 유무 예측은 높은 위음성률을 고려할 때 감시림프절 검사와 병행하는 것이 안전할 것으로 판단된다. Purpose: The aim of this study was evaluate predictive value of preoperative sonography for the evaluation of axillary lymph node metastases in breast cancer patients. Materials and Methods: The study included 226 patients who underwent curative surgery between Jan. 2008 ~Dec. 2010 at Inje University Sanggye Paik Hospital. We analyzed preoperative sonographic findings of axillary lymph nodes and compared the finding with postoperative histologic results of axillary lymph nodes evaluation. Results: When we compared preoperative sonographic evaluation of metastatic lymph node with final histological results, the sensitivity of sonographic evaluation was 81.3% and specificity was 77.5%. False positive rate was 10.7% and false negative rate was 35.8%. The accuracy of preoperative sonographic evaluation of lymph node metastasis was 78.7%. Primary tumor size was the only significant predictive factor for lymph node metastasis on multivariate analysis. Conclusion: preoperative sonographic evaluation of axillary lymph node had limited value with moderate accuracy. High false-negative rate of preoperative sonography indicates that preoperative sonography cannot replace intraoperative sentinel node evaluation at this stage.

Altered VEGF Regulation in Ovariectomized Rat Alveolar Bone Sockets by Bisphosphonate

Dong-Wook Yang,Geum-Dong Han,Sun-Hun Kim 대한구강해부학회 2018 대한구강해부학회지 Vol.39 No.1

Bisphosphonates reduce bone loss by suppressing osteoclast activity and are currently used for the treatment of osteoporosis. As a side effect of bisphosphonates treatment, the emergence of osteonecrosis of the jaw (ONJ) has stimulated interest in elucidating how bisphosphonates affect the bone, but far less understanding exists as to the ONJ mechanism. In the present study, it was hypothesized that bisphosphonates may affect the healing of the alveolar socket by altering VEFG regulation. In vivo osteoporosis rat models were made by bilateral surgical ovariectomy. Pamidronate (3.5 mg/kg/wk) was IP injected for 8 wks and the maxillary 1st molars were bilaterally extracted. For in vitro test, periodontal ligament cells were treated with pamidronate. Unexpectedly, VEFG-A and -B mRNA and protein levels were increased in in vivo and in vitro by the high concentration treatment of bisphosphonates. However, VEGF-C level was not changed. In the socket at day 7 after the molar extraction, the socket was filled with infiltration of neutrophils which showed strong immunoreactivity against VEGF. VEGF-B mRNA was in particular upregulated by the pamidronate treatment. This result suggest that high dose pamidronate may alter VEGF expression that may serve as another mechanism of ONJ.

Clinical Outcomes of Intracardiac Echocardiography-Guided Contrast Agent-Free Cryoballoon Ablation in Atrial Fibrillation Patients With Renal Insufficiency

Dong Geum Shin,Jinhee Ahn,Sang Hyun Park,Sang-Jin Han,Hong Euy Lim The Korean Society of Cardiology 2024 Korean Circulation Journal Vol.54 No.2

Background and Objectives: Previous studies have reported an association between impaired renal function and poor outcomes after radiofrequency catheter ablation in patients with atrial fibrillation (AF). However, outcomes of cryoballoon ablation (CBA) in patients with renal insufficiency are not fully elucidated. This study aimed to compare outcomes of CBA in AF patients with chronic kidney disease (CKD) versus those without CKD and to assess changes in renal function over 12 months following CBA. Methods: A total of 839 patients (65.1% with non-paroxysmal AF [PAF]) who underwent de novo CBA were prospectively enrolled. We divided patients into two groups based on creatinine clearance rate (CCr) and performed intracardiac echocardiography (ICE)-guided contrast agent-free CBA. Results: In comparison with patients without CKD (CCr >50, n=722), those with CKD (CCr ≤50, n=117) were older and predominantly female, had a lower body mass index, and showed a higher prevalence of heart failure and hypertension. Mean CHA₂DS₂-VAS score was significantly higher in CKD group than in non-CKD group. Procedure-related complications were not significantly different between two groups. During a mean follow-up period of 25.4±11.9 months, clinical recurrence occurred in 182 patients (21.7%) and not significantly different between two groups. In multivariate analysis, non-PAF and left atrial size were independent predictors of AF recurrence. CCr levels significantly improved over 12 months after CBA in CKD group. Conclusions: ICE-guided contrast-agent-free CBA showed comparable long-term clinical outcomes without increasing procedure-related complications and improvement of renal function over 12 months following CBA in AF patients with CKD.

The impact factors on 5-year survival rate in patients operated with oral cancer

Dong-Ho Geum,Young-Chea Roh,Sang-Yong Yoon,Hyo-Geon Kim,Jung-Han Lee,Jae-Min Song,Jae-Yeol Lee,Dae-Seok Hwang,Yong-Deok Kim,Sang-Hun Shin,In-Kyo Chung,Uk-Kyu Kim 대한구강악안면외과학회 2013 대한구강악안면외과학회지 Vol.39 No.5

Objectives: The purpose of this study is to analyze clinical impact factors on the survival rate, and to acquire basic clinical data for the diagnosis of oral cancer, for a determination of the treatment plan with long-term survival in oral cancer patients. Materials and Methods: Through a retrospective review of the medical records, the factors for long-term survival rate were analyzed. Thirty-seven patients, among patient database with oral cancer treated in the Department of Oral and Maxillofacial Surgery at Pusan National University Hospital within a period from March 1998 to March 2008, were selected within the study criteria and were followed-up for more than 5 years. The analyzed factors were gender, age, drinking, smoking, primary tumor site, type of cancer, TNM stage, recurrence of affected region, and metastasis of cervical lymph node. The 5-year survival rate on the impact factors was calculated statistically using the Kaplan-Meier method. Results: By classification of clinical TNM at the 1st visit, there were 11 (29.7%) cases for stage I, 11 (29.7%) cases for stage II, 3 (8.1%) cases for stage III, and 12 (32.5%) cases for stage IV. The 5-year survival rate of total oral cancer patients after the operation were 75.7%, pathological TNM stage related 5-year survival rate were as follows: stage I 90.0%, stage II 81.8%, stage III 100% and stage IV 45.5%; in which the survival rate difference by each stage was significantly observed. The recurrence of cervical lymph node was the significant impact factor for the survival rate, because only 30.0% the survival rate in recurrent cases existed. During the follow-up, there were 15 (40.5%) patients with confirmed recurrence, and the 5-year survival rate of these patients was decreased as 46.7%. Conclusion: The classification of clinical and pathological TNM stage, local recurrence after surgery, and metastasis of cervical lymph node after surgery were analyzed as the 3 most significant factors.

A Novel Model for Predicting Hepatocellular Carcinoma Development in Patients with Chronic Hepatitis B and Normal Alanine Aminotransferase Levels

( Dong Hyun Sinn ),( Jeong-hoon Lee ),( Kyunga Kim ),( Joong Hyun Ahn ),( Ji Hyeon Lee ),( Jung Hee Kim ),( Dong Hyeon Lee ),( Jung-hwan Yoon ),( Wonseok Kang ),( Geum-youn Gwak ),( Yong-han Paik ),( 대한간학회 2017 Gut and Liver Vol.11 No.4

Background/Aims: Hepatocellular carcinoma (HCC) can develop in chronic hepatitis B (CHB) patients with normal alanine aminotransferase (ALT) levels. Therefore, methods that can stratify an individual`s HCC risk are needed. Methods: A simple HCC risk score was developed from 971 patients with CHB who had elevated hepatitis B virus DNA levels (>2,000 IU/mL) with normal or mildly elevated ALT levels (<80 U/L). The score was validated from an independent cohort of 507 patients. Results: A 4-point risk scale was developed, with HCC risk ranging from 0% to 17.8% at 5 years for the lowest and highest risk scores. The D2AS score had high area under the receiver operating curves (AUROCs) for predicting development of HCC at 3/5 years (0.895/0.884). The calculated AUROCs to predict the development of HCC at 3/5 years were 0.889/0.876 in the validation cohort, with 5-year HCC incidence rates ranging from 0% to 13.8% at 5 years for the lowest and highest risk scores. Conclusions: The D2AS risk score can play a valuable role in risk stratification and may be useful for guiding clinical decisions for enhanced surveillance or treatment to reduce the HCC risk in CHB patients with normal or mildly elevated ALT levels. (Gut Liver 2017;11:528-534)

Inhibition of Cellular Proliferation by p53 dependent Apoptosis and G2M Cell Cycle Arrest of Saussurea lappa CLARKE in AGS Gastric Cancer Cell Lines

Han Su Jeong,Dong Jo Kim,Geum Jeong Heo,Chang Gyu Nam,Seong Gyu Ko 한의병리학회 2004 동의생리병리학회지 Vol.18 No.4

Prognostic Implication of Platelet Reactivity According to Left Ventricular Systolic Dysfunction Status in Patients Treated With Drug-Eluting Stent Implantation: Analysis of the PTRG-DES Consortium

Han Donghoon,Kim Sun-Hwa,Shin Dong Geum,Kang Min-Kyung,Choi Seonghoon,Lee Namho,Kim Byeong-Keuk,Joo Hyung Joon,Chang Kiyuk,Park Yongwhi,Song Young Bin,Ahn Sung Gyun,Suh Jung-Won,Lee Sang Yeub,Her Ae-Y 대한의학회 2024 Journal of Korean medical science Vol.39 No.3

Background: Coronary artery disease patients undergoing percutaneous coronary intervention (PCI) often exhibit reduced left ventricular ejection fraction (LVEF). However, the impact of LV dysfunction status in conjunction with platelet reactivity on clinical outcomes has not been previously investigated. Methods: From the multicenter PTRG-DES (Platelet function and genoType-Related long-term prognosis in DES-treated patients) consortium, the patients were classified as preserved-EF (PEF: LVEF ≥ 50%) and reduced-EF (REF: LVEF< 5 0%) group by echocardiography. Platelet reactivity was measured using VerifyNow P2Y12 assay and high platelet reactivity (HPR) was defined as PRU ≥ 252. The major adverse cardiac and cerebrovascular events (MACCEs) were a composite of death, myocardial infarction, stent thrombosis and stroke at 5 years after PCI. Major bleeding was defined as Bleeding Academic Research Consortium bleeding types 3–5. Results: A total of 13,160 patients from PTRG-DES, 9,319 (79.6%) patients with the results of both PRU and LVEF were analyzed. The incidence of MACCE and major bleeding was higher in REF group as compared with PEF group (MACCEs: hazard ratio [HR] 2.17, P < 0.001, 95% confidence interval [CI] 1.85–2.55; major bleeding: HR 1.78, P < 0.001, 95% CI 1.39–2.78). The highest rate of MACCEs was found in patients with REF and HPR, and the difference between the groups was statistically significant (HR 3.14 in REF(+)/HPR(+) vs. PEF(+)/HPR(-) group, P < 0.01, 95% CI 2.51–3.91). The frequency of major bleeding was not associated with the HPR in either group. Conclusion: LV dysfunction was associated with an increased incidence of MACCEs and major bleeding in patients who underwent PCI. The HPR status further exhibited significant increase of MACCEs in patients with LV dysfunction in a large, real-world registry.

Efficacy and Safety of Ledipasvir/Sofosbuvir Therapy in HCV Genotype 1 Korean Patients

( Dong Hoon Lew ),( Wonseok Kang ),( Dong Hyun Sinn ),( Geum-youn Gwak ),( Yong-han Paik ),( Moon Seok Choi ),( Joon Hyeok Lee ),( Kwang Cheol Koh ),( Seung Woon Paik ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Ledipasvir/sofosbuvir therapy has demonstrated potent antiviral activity in patients with genotype 1 chronic hepatitis C virus (HCV) infection, yet its efficacy has not been proved in a real-life cohort of Korean patients. We assessed efficacy and safety of ledipasvir/ sofosbuvir therapy in a real-life cohort of Korean patients with genotype 1 chronic HCV infection. We also aimed to study whether successful antiviral therapy leads to improvement of liver fibrosis. Methods: Between February 2016 and December 2016, a total of 39 patients with genotype 1 chronic HCV infection were retrospectively enrolled at Samsung Medical Center, Seoul, Korea. Clinical and laboratory findings were collected at baseline and 12 weeks after completion of treatment. Liver fibrosis status was assessed at baseline and at post-treatment week 12 using well-known non-invasive biochemical methods, including APRI (AST to Platelet Ratio Index) and FIB-4 (Fibrosis-4) indices. Results: Of 39 patients, 2 patients (5.1%) had genotype 1a and 37 (94.9%) had genotype 1b chronic HCV infection. Eighteen patients (46.2%) were treatment-naïve and 22 (56.4%) were treatment- experienced, including 2 patients who failed previous direct-acting antiviral treatment. Eight patients (20.5%) had cirrhosis. SVR12 was achieved in 39 patients (SVR12 100%). No serious adverse events were observed. A significant improvement of liver fibrosis status after achieving SVR12 as compared to baseline was demonstrated by APRI and FIB-4 indices (1.532 vs. 0.6351, P <0.001 and 5.392 vs. 3.553, P <0.01, respectively). Conclusions: Ledipasvir/sofosbuvir therapy has demonstrated high efficacy and safety for both treatment-naïve and treatment-experienced patients with HCV genotype 1 infection, including those who had previous exposure to other direct-acting antiviral agents. A significant improvement of liver fibrosis status was shown after achieving SVR12.