초음파법을 이용한 콘크리트 시공이음부 공극 및 내부공동의 화상검출 해석에 관한 연구

박석균,백운찬,이한범 대전대학교 산업기술연구소 2000 산업기술연구소 論文集 Vol.11 No.2

The joint and void treatment of concrete is one of the technical problems in construction. Joints and voids created with the construction result in serious weakness from the aspects of both structural and water-barrier function. Ultrasonic image processing technique was used for the inspection of construction joints of SRC(Steel-frame Reinforced Concrete) column and voids of concrete block in this study. The advantages and limitations of this technique for non-destructive inspection in construction joints and voids are investigated. As a result, it has been verified that the semi-direct measurement type is more effective than the other types for detecting the construction joints and voids using ultrasonic method.

초음파법을 이용한 콘크리트 역타시공 이음부 공극의 화상검출특성

박석균,백운찬,이한범,김명모 한국비파괴검사학회 2000 한국비파괴검사학회지 Vol.20 No.4

최근 역타시공법 등에 의한 콘크리트 구조물의 시공이 증가 추세에 있다. 이 경우, 자주 발생되는 신ㆍ구타설 콘크리트 시공이음부의 공극은 향후 구조물의 구조적인 특성과 내구성 등에 큰 영향을 미치게 된다. 그러나 현재 제안되고 있는 비파괴 검사법으로는 효과적으로 이음부 공극을 평가하기에 많은 한계가 있다. 본 연구에서는 시공이음부의 콘크리트 충전상태를 평가하기 위해 철골철근 콘크리트와 무근 콘크리트 시험체내에 공극을 모의제작한 후, 초음파속도 측정을 실시하고, 화상처리기법을 이용하여 비교적 용이하게 해석 가능한 방법에 대해 검토하였다.

급성 골수성 백혈병에서 다약제내성(MDR-1) 유전자 발현의 빈도 및 임상적 의의

백진호,박성원,김동환,정진태,곽동석,박소향,손상균,서장수,이건수,이재태,이규보 경북대학교 병원 2001 경북대학교병원의학연구소논문집 Vol.5 No.1

배경:백혈병 치료성적이 나쁜 이유 중 하나는 항암제에 대한 내성이며 특히 다약제내성(MDR-1)유전자의 과발현이 치료실패의 중요한 원인이다.가장 많이 알려진 P-당단백은 MDR-1 유전자에 의해 발현된 transmembrane단백으로 항암제가 암세포내로 유입 축적되는 것을 방해함으로써 내성을 나타낸다.급성 골수성 백혈병에서 MDR-1유전자의 발현빈도와 항암치료에 대한 반응, 환자의 성, 나이, 염색체 이상, 혈청 LDH, 혈청 thymidine kinase, 수행능력, 백혈병의 아형, 혈색소, 말초혈액 및 골수의 골수아세포의 비율, CD34와 CD7 세포면역표지자 등과의 연관성에 대해 알아보았으며, 화학요법을 시행받은 환자를 대상으로 MDR-1유전자 발현과 완전 관해유도, 무병생존기간 및 전체생존기간의 임상경과를 비교 검토하였다. 방법:1994년 3월부터 1999년 6월까지 경북대학교 병원 혈액종양내과에서 처음 진단받은 급성 골수성 백혈병환자 36명을 대상으로 골수 또는 말초혈액을 채취하여 RNA를 추출하여 MDR-1 유전자와 β-actin분절의 시발체를 이용하여 역전이중합효소연쇄반응으로 PCR합성체를 만들어 전기영동하여 MDR-1유전자의 발현유무를 확인하였다. 결과:평균 연령은 43.69세(18∼77세)였으며, 남녀수는 16명과 20명이었다.MDR-1유전자는 19명(52.8%)에서 발현되었으며 MDR-1유전자의 발현율과 CD34와 CD7 세포면역표지자의 연관성을 분석한 결과 통계적으로 유의한 상관관계가 있었다.염색체 검사의 소견에서 예후가 양호한 군이 27명(75.0%), 예후가 나쁜 군은 9명(25.0%)이었고,MDR-1유전자 발현율과 연관성을 분석한 결과 MDR-1유전자 음성군에서 양호한 예후를 나타내는 염색체는 19명 중 11명(57.9%)으로 유의한 연관성을 보였다.관해유도화학요법후 말초혈액에서 골수아세포가 소실될 때까지의 시간은 MDR-1유전자 음성군이 5.4일로 양성군의 12.0일보다 짧았으나 통계적인 의미는 없으며, MDR-1유전자 발현은 환자의 나이, 수행능력, 백혈병 아형, 혈색소, 말초혈액 및 골수의 골수아세포 비율, 혈청LDH, 혈청 thymidine kinase, 비장종대 유무, 알부민 수치 등과 연관성이 없었다.MDR-1유전자 발현과 완전 관해유도와의 연관성을 분석한 결과 MDR-1유전자 음성군에서는 14명 중 13명(92.9%)이, 양성군에서는 12명 중 4명(33.3%)이 완전관해가 유도되어 통계적으로 유의한 차이가 있었으며, 무병생존기간과 전체 생존기간과의 연관성을 분석한 결과 통계적인 차이가 없었다. 결론:급성 골수성 백혈병에서 MDR-1유전자 발현율은 염색체 분류와 더불어 관해유도화학요법의 치료반응 유무를 예견할 수 있는 유용한 지표로 사용될 수 있고, 향후 치료전략을 수립하는데 참고할 자료가 되리라고 본다. Background:The expression of the multidrug resistance-1(MDR-1) gene which encodes p-glycoprotein, is recognized as a biological mechanism possibly contributing to treatment failure in patients with acut myeloid leukemia(AML). Recent studies indicate its association with poor risk factors such as cytogenetic partten and surface phenotype of blasts.We analyzed the role of MDR-1 gene expression in 36 chemo-naive AML patients. Methods: In 36 patients, clinical data were reviewed and compared to MDR-1 gene expression, immunophenocyping results on CD7 & CD34, cytogenetic pattern and other suggestive prognostic factors. Results: Median follow-up period was 250 days. The MDR-1 geng expression was obserned in 19 out of 36 patients(52.8%). Significant correlation between MDR-1 gene and CD7 & CD34 expression was found. SIxteen out of 17(94.1%) MDR-1 negative patients harbored favorable cytogenetic patterns, where as 11 out of 19 (57.9%) MDR-1 positive patients had favorable cytogenetic patterns. MDR-1 gene expression was not correlated to disease ferr survival(DFS), nor overall survival(OS) statistically although it has shown significant correlation to complete remission(CR) rate(p=0.001). Conclusion: We found that lack MDR-1 geng expression was exclusively associated to favorable cytogenetic patterns in our study.In order of MDR-1 geng and clinical outcome or other prognostic features, including cytogenetic pattren,further larger studies would be necessary.(Korean J Hematol 2000;35:117~125)

Association of CTTN polymorphisms with the risk of colorectal cancer

Seok Youn Lee,Dong Baek Kang,Won Cheol Park,Jeong Kyun Lee,Soo Cheon Chae 대한외과학회 2012 Annals of Surgical Treatment and Research(ASRT) Vol.82 No.3

Purpose: Various studies searching for biomarkers to predict tumor metastasis or prognosis in both esophageal squamous cell carcinoma (ESCC) and head and neck squamous cell carcinoma (HNSCC) are currently underway. However, few data have been reported on its association with colorectal cancer (CRC). Single nucleotide polymorphisms (SNPs) are the most common known form of human genetic variation and may contribute to an increased susceptibility to cancer including CRC. The present study aimed to investigate whether the polymorphisms in the CTTN gene are associated with susceptibility to CRC in the Korean population. Methods: A case-control study was performed to examine the relationship between the CTTN g.-9101C>T, g.-8748C>T, and g.72C>T polymorphisms and the risk of CRC. Polymerase chain reaction-restriction fragment length polymorphism analysis of g.-8748C>T, g.-9101C>T and Taqman analysis of g.72C>T were performed on blood samples from 218 patients with CRC and 533 control individuals. The g.-9101C>T, g.-8748C>T, and g.72C>T SNPs in CTTN and their haplotypes were analyzed. Results: The genotype and allele frequencies of g.-9101C>T, g.-8748C>T, and g.72C>T did not differ between the patient group and the control group. Further, the haplotype of CTTN g.-9101C>T, g.-8748C>T, and g.72C>T did not differ between patient group and the control group. However, the genotype and allele frequencies of CTTN g.-9101C>T were significantly increased in the lymph node positive CRC group compared to the control group. Conclusion: The CTTN g.-9101C>T polymorphism may influence lymph node positive CRC.

Application of single incision laparoscopic surgery for appendectomy in children

Dong Baek Kang,Seung Hyun Lee,Seok Youn Lee,Jung Taek Oh,Dong Eun Park,Cheol Lee,Duk Hwa Choi,Won Cheol Park,Jeong Kyun Lee 대한외과학회 2012 Annals of Surgical Treatment and Research(ASRT) Vol.82 No.2

Purpose: Recently, single incision laparoscopic surgery (SILS) has been popular in use with its progress studied for more minimally invasive surgery and cosmetic improvement. We investigated the feasibility and efficacy of SILS for appendectomy (SILS-A) in children and compare it with conventional laparoscopic appendectomy (C-LA). Methods: We studied, retrospectively, adolescent patients who underwent C-LA or SILS-A. There were 25 patients in the C-LA group and 30 patients in the SILS-A group. The clinical outcomes were compared between the groups. Results: The SILS-A procedures were performed successfully in adolescent patients . There were no significant difference between the C-LA and SILS-A group with respect to demographic data and post-operative outcomes. There was one complication (4%) in the C-LA group and two complications (6.6%) in the SILS-A group, but there was no significant difference. Conclusion: SILS-A was technically feasible and safe in children. Considering little postoperative scar and no difference in post-operative outcomes compared to C-LA, SILA could be applicable in adolescent patients. Larger studies and further technical implements will be necessary to assess the true benefit of this approach.

The Involvement of Phospholipase A₂in The Cytokine-induced Inhibition of Bone Formation and Mineralization

Sang-Kyun Kim,In-Seok Lee,Jeong-Hwa Baek,Gwan-Shik Kim 대한구강생물학회 1997 International Journal of Oral Biology Vol.22 No.2

New synergistic efficacy of combination of romiplostim and steroid in refractory immune thrombocytopenia patients

( Jun Seok Yoon ),( Yoo Jin Lee ),( Dong Won Baek ),( Hye Young Park ),( Bo Eun Park ),( Joon Ho Moon ),( Sang Kyun Sohn ) 대한내과학회 2018 The Korean Journal of Internal Medicine Vol.33 No.2

가상 CNC 밀링머신

백대균(Dae-Kyun Baek),오명석(Myung-Seok Oh) 한국산업융합학회 2001 한국산업융합학회 논문집 Vol.4 No.4

This paper presented a new model of virtualized CNC milling machine. The model verifies the over cut, the under cut and the surface roughness using NC file generated from CAM and cutting condition. The model uses Z-map model to verify workpiece. In this paper, the model used the velocities of x, y and z direction and obtained a center point of a hall end mill for modeling Z-map of workpiece. To investigate the performance of the model, simulation study was carried out. As the results, the model gave geometry accuracy of workpiece, the surface roughness and the chip loads in finish cutting that can predict tool chipping. The virtualized CNC machine can he used a flat end mill, a ball end mill and a rounded end mill.<br/>

절삭공구의 열변형 오차 및 절삭력 변형 오차에 관한 연구

오명석(Myung-Seok Oh),윤인준(In-Jun Yoon),백대균(Dae-Kyun Baek) 한국산업융합학회 2002 한국산업융합학회 논문집 Vol.5 No.4

This paper presents a method to predict tool deflection induced by the thermal distribution and the cutting force using FEM in milling operation. The thermal distribution of cutting tool was predicted using FEM after measuring the temperature of the end of tool and of the tool holder. The thermal deflection of cutting tool was predicted using FEM as well. The tool deflection induced by the cutting force was analyzed with the solid model of cutting tool. An end mill tool caused most of tool deflection comparing to tool holder. Most of thermal deflection came from Z-direction and most of tool deflection induced by the cutting force came from X and Y direction. Precision cutting will be accomplished when tool locations are generated considering the thermal deflection of cutting tool and the tool deflection induced by the cutting force in CAD/CAM.

Rituximab plus multiagent chemotherapy for newly diagnosed CD20-positive acute lymphoblastic leukemia: a prospective phase II study

( Dong Won Baek ),( Han-seung Park ),( Sang Kyun Sohn ),( Dae Young Kim ),( Inho Kim ),( Jae-sook Ahn ),( Young Rok Do ),( Se Ryeon Lee ),( Hyeon-seok Eom ),( Won-sik Lee ),( Sung-hyun Kim ),( Ho Sup 대한내과학회 2023 The Korean Journal of Internal Medicine Vol.38 No.5

Background/Aims: We performed a prospective study to determine the efficacy and safety of rituximab including chemotherapy in CD20-positive acute lymphoblastic leukemia (ALL). Methods: Patients with newly diagnosed ALL, aged ≥ 15 years, were eligible for the study if their leukemic blast cells in bone marrow expressed CD20 ≥ 20% at the time of diagnosis. Patients received multiagent chemotherapy with rituximab. After achieving complete remission (CR), patients received five cycles of consolidation with concomitant rituximab. Rituximab was administered monthly from day 90 of transplantation for patients who received allogeneic hematopoietic cell transplantation. Results: In patients with Philadelphia (Ph)-negative ALL, 39 of 41 achieved CR (95.1%), the 2- and 4-year relapse-free survival (RFS) rates were 50.4% and 35.7%, and the 2- and 4-year overall survival (OS) rates were 51.5% and 43.2%, respectively. In the group with Ph-positive ALL, all 32 patients achieved CR, the 2- and 4-year RFS rates were 60.7% and 52.1%, and the 2- and 4-year OS rates were 73.3% and 52.3%, respectively. In the Ph-negative ALL group, patients with higher CD20 positivity experienced more favorable RFS (p < 0.001) and OS (p = 0.06) than those with lower CD20 positivity. Patients who received ≥ 2 cycles of rituximab after transplantation had significantly improved RFS (hazard ratio [HR], 0.31; p = 0.049) and OS (HR, 0.29; p = 0.021) compared with those who received < 2 cycles. Conclusions: The addition of rituximab to conventional chemotherapy for CD20-positive ALL is effective and tolerable (Clinicaltrials.gov NCT01429610).