고로슬래그시멘트를 사용한 다공성 황토콘크리트의 성능 평가

김황희,강수만,박종식,박상우,전지홍,이진형,차상선,박찬기,Kim, Hwang-Hee,Kang, Su-Man,Park, Jong-Sik,Park, Sang-Woo,Jeon, Ji-Hong,Lee, Jin-Hyung,Cha, Sang-Sun,Park, Chan-Gi 한국농공학회 2010 한국농공학회논문집 Vol.52 No.3

This study aims to evaluate a porous concrete using hwang-toh, blast furnace slag and blast furnace slag (BFS) cement instead of type I cement. The tests that were carried out to analysis the properties of porous hwang-toh BFS cement concrete included compressive strength, continuous void ratio, absorption rate, and pH value, repeated freezing and thawing test were conducted. Test results indicated that the performance in porous hwang-toh concrete are effective on the kaoline based binder materials. The pH value were shown in about 9.5 ~ 8.5. The compressive strength was increased and void ratio was decreased with increasing the kaoline based binder materials, respectively. The void ratio and compressive strength were in the range of about 21 ~ 30 %, 8 ~ 13 MPa, respectively. The increased in void ratio of more than 25 % is showed to reduce the resistance of repeated freezing and thawing. Also, the resistance of repeated freezing of thawing and the compressive strength of porous hwang-toh BFS cement concrete are independent with hwang-toh content and BFS cement amount. But, the void ratio was decreased with increasing the high volume hwang-toh contents (more than 15 %).

반응표면 분석법을 이용한 천연마섬유보강 순환굵은골재 콘크리트의 성능 평가

전지홍,김황희,김춘수,유성열,박찬기,Jeon, Ji Hong,Kim, Hwang Hee,Kim, Chun Soo,Yoo, Sung Yeol,Park, Chan Gi 한국농공학회 2014 한국농공학회논문집 Vol.56 No.4

In this study, evaluated ware the strength and durability of the vegetated water purification channel concrete to which recycled aggregates, hawang-toh and jute were applied. Box-Behnken method of response surface analysis in statistics was applied to the experimental design. Experimental variables are as follows, recycled coarse aggregates, hawang-toh, blast-furnace slag and jute fiber. In the experiment, conducted were the tests of compressive strength, chloride ion penetration, abrasion resistance and impact resistance the replacement rate effects of the recycled aggregates, blast-furnace slag and hwang-toh on the performance of vegetated water purification channel concrete were analyzed by using the response surface analysis method on the basis of the experimental results. In addition, an optimum mixing ratio of vegetated water purification channel concrete was determined by using the experimental results. The optimum mixing ratio was determined to be in 10.0% recycled coarse aggregates, 60.0% blast-furnace slag, 10.1% hwang-toh and 0.16% jute fiber. The compressive strength, chloride ion penetration, abrasion rate, and impact number of fracture test results of the optimum mixing ratio were 24.1 MPa, 999 coulombs, 10.30 g/mm3, and 20 number, respectively.

Donor Biliary Complications in High-Volume Living-Donor Liver Transplantation Center in Korea

( Gi-won Song ),( Gil-chun Park ),( Dong-hwan Jung ),( Tae-yong Ha ),( Ki-hun Kim ),( Shin Hwang ),( Sung-gyu Lee ),( Eun-kyung Jwa ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Donor safety is the most important Living donor liver transplantation. Biliary complication is common complications in donor hepatectomy. This study intended to analyze the incidence and outcomes of donor biliary complications in a Korean high-volume LT center. Methods: Institutional LT database was searched from 2006.01.01 to 2011.05.31. Their medical records and imaging studies were reviewed. All of them did AMC technique for BD division. Results: Between 2006.01.01-2011.5.31, total 1658 donors did hepatectomy in AMC center. Among them, 1099 were male and 559 were female. Graft types were Right liver graft in 1302 (78.5%), Left liver graft in 274 (16.5%), Left lateral section graft in 72 (4.3%) and Right posterior section graft in 10 (0.6%). Mean age of total donor was 29 years and Mean steatosis of liver was 5.7%. Mean hospital days was 12days and Mean follow-up period were 17.5 month. Among 1658 donors, the biliary complications occurred in 47 donors (2.7%). Most of them were bile leak, only 2 case were bile duct stenosis. All of the biliary complication occurred in early period (< 1 month). In the biliary complication(BC) group, the 10 donors did percutaneous drainage(21.3%) and the 12 donors did ERCP(25.5%) and the only one donor was re-operated. Mean hospital days in BC group was 22 days and mean duration of treatment was 1.8 month. Hospital days in BC group was more longer than non- BC group but, there is no significant difference. Conclusions: Very low incidence of BC in donor by using AMC technique for BD division. The incidence of late BC in LD hepatectomy is neglisible.

The reno-protective effect of a phosphoinositide 3-kinase inhibitor wortmannin on streptozotocin-induced proteinuric renal disease rats

Sang Hoon Kim,Young-Woo Jang,Patrick Hwang,Hyun-Jung Kim,Gi-Yeon Han,김찬화 생화학분자생물학회 2012 Experimental and molecular medicine Vol.44 No.1

Diabetic nephropathy (DN) is a progressive kidney disease that is caused by injury to kidney glomeruli. Podocytes are glomerular epithelial cells and play critical roles in the glomerular filtration barrier. Recent studies have shown the importance of regulating the podocyte actin cytoskeleton in early DN. The phosphoinositide 3-kinase (PI3K) inhibitor, wortmannin, simultaneously regulates Rac1 and Cdc42, which destabilize the podocyte actin cytoskeleton during early DN. In this study, in order to evaluate the reno-protective effects of wortmannin in early DN by regulating Rac1and Cdc42, streptozotocin (STZ)-induced proteinuric renal disease (SPRD) rats were treated with wortmannin. The albuminuria value of the SPRD group was 3.55± 0.56 mg/day, whereas wortmannin group was 1.77± 0.48 mg/day. Also, the albumin to creatinine ratio (ACR) value of the SPRD group was 53.08 ± 10.82mg/g, whereas wortmannin group was 20.27 ± 6.41mg/g. Changes in the expression level of nephrin, podocin and Rac1/Cdc42, which is related to actin cytoskeleton in podocytes, by wortmannin administration were confirmed by Western blotting. The expression levels of nephrin (79.66 ± 0.02), podocin (87.81 ± 0.03) and Rac1/Cdc42 (86.12 ± 0.02) in the wortmannin group were higher than the expression levels of nephrin (55.32 ± 0.03), podocin (53.40 ±0.06) and Rac1/Cdc42 (54.05 ± 0.04) in the SPRD group. In addition, expression and localization of nephrin, podocin and desmin were confirmed by immunofluorescence. In summary, we found for the first time that wortmannin has a reno-protective effect on SPRD rats during the early DN. The beneficial effects of wortmannin in SPRD rats indicate that this compound could be used to delay the progression of the disease during the early DN stage.

Long-term Clinical Outcomes of Radiofrequency Catheter Ablation versus Permanent Pacemaker Implantation in Patients with Tachycardia-Bradycardia Syndrome

Sang-Cheol Cho,Eun-Sun Jin,Sang Yong Om,Ki Won Hwang,최형오,Ki-Hun Kim,Sung-Hwan Kim,Kyoung-Min Park,Jun Kim,Ki-Joon Choi,You-Ho Kim,Gi-Byoung Nam 대한심장학회 2020 Korean Circulation Journal Vol.50 No.11

Background and Objectives: Pacemaker (PM) implantation is a well-accepted treatment option for patients with paroxysmal atrial fibrillation (AF) and related tachycardia-bradycardia syndrome (TBS). Data on the long-term clinical outcomes after radiofrequency catheter ablation (RFCA) or PM implantation are sparse. Methods: The medical records of 217 patients with TBS were retrospectively assessed. Outcomes in patients who underwent RFCA (n=108, 49.8%) were compared to those with PM implantation (n=109, 50.2%). The clinical outcomes were sinus rhythm maintenance, conversion to persistent AF, additional procedure or crossover, and the composite of cardiovascular hospitalization and death. Results: During the follow-up period (mean 3.5±2.0 years), the RFCA group, compared to the PM group, showed better sinus rhythm maintenance (adjusted hazard ratio [aHR], 0.27; 95% confidence interval [CI], 0.15–0.46; p=0.002) and less progression to persistent AF (aHR, 0.20; 95% CI, 0.06–0.63; p=0.006). Additional procedure or crossover did not differ significantly between the groups (aHR, 2.07; 95% CI, 0.71–6.06; p=0.185 and aHR, 0.69; 95% CI, 10.8–2.67; p=0.590, respectively). Most RFCA patients (92.6%) did not require pacemaker implantation during long term follow-up period (>3.5 years). The composite endpoint of cardiovascular rehospitalization and death was not significantly different between the groups (aHR, 0.92; 95% CI, 0.50–1.66; p=0.769). Conclusions: RFCA is an effective alternative to PM implantation in patients with TBS. In these patients, successful RF ablation of AF is related to a higher rate of sinus rhythm maintenance compared to PM implantation, and the composite outcome of cardiovascular rehospitalization and death is similar.

Tverberg Type Extension of Dittert's Conjecture

Hwang, Suk-Geun,Cheon, Gi-Sang 성균관대학교 기초과학연구소 1990 論文集 Vol.41 No.1

이 논문에서는 Dittert함수 φ를 확장한 φ_k함수에 대한 Tverberg type의 예상문제를 제기하고, φ_k의 여러 가지 성질을 究明한다. 지금까지 φ에 관하여 성립하는 거의 모든 성질이 φ_k에서도 성립함을 또한 밝힌다.

Patency of Hemashield grafts versus ringed Gore-Tex grafts in middle hepatic vein reconstruction for living donor liver transplantation

Sang Hoon Kim,Shin Hwang,Minjae Kim,Tae-Yong Ha,Gi-Won Song,Dong-Hwan Jung,Chul-Soo Ahn,Deok-Bog Moon,Ki-Hun Kim,Gil-Chun Park,Sung-Gyu Lee 한국간담췌외과학회 2021 Annals of hepato-biliary-pancreatic surgery Vol.25 No.1

Backgrounds/Aims: Owing to the short supply of homologous vein allografts, we previously used ringed Gore-Tex vascular grafts for middle hepatic vein (MHV) reconstruction in living donor liver transplantation. When ringed Gore-Tex grafts became unavailable, we used Hemashield vascular grafts. This study aimed to compare the patency and complication rates of Hemashield and ringed Gore-Tex grafts. Methods: This retrospective two-arm study compared the study group that received Hemashield grafts (n=157) and the propensity score-matched control group that received ringed Gore-Tex grafts (n=157). Results: In the Hemashield and Gore-Tex groups, the recipient age was 54.7±9.4 and 53.3±6.3 years; Model for End-stage Liver Disease scores were 15.9±9.2 and 16.9±8.3; and graft-recipient weight ratios were 1.07±0.24 and 1.10±0.23, respectively. In the Hemashield group, V5 reconstruction was performed using single (n=113, 72.0%), double (n=39, 24.8%), and triple (n=3, 1.9%) anastomoses. The proportion of double and triple anastomoses for V5 and V8 was higher in the Hemashield group than in the Gore-Tex group. Two (1.3%) patients required MHV conduit stenting owing to early thrombosis of the Hemashield graft. There was no difference in conduit occlusion-free patient survival rates between groups (p=0.91). The incidence of accidental conduit migration in the Hemashield and Gore-Tex groups was 0 (0%) and 2 (1.3%), respectively. Conclusions: Hemashield grafts used in MHV reconstruction demonstrated acceptably high short- and mid-term patency rates, no incidences of conduit migration, easy handling, and good flexibility for length adjustment. Therefore, we suggest that the Hemashield graft is the preferentially suitable prosthetic material for MHV reconstruction.

Precise multiplex expression profiling based on MLPA-CE-SSCP

Gi Won SHIN,Hee Sung HWANG,Boram CHUNG,Gyoo Yeol JUNG 한국생물공학회 2011 한국생물공학회 학술대회 Vol.2011 No.4

Embodiment of Spatially Arterial Pulse Diagnostic Apparatus using Array Multiple Hall Devices

Sang-Suk Lee,Gi-Wang Kim,Myung-Cheon Ahn,Young-Seok Park,Jong-Gu Choi,Sang-Dae Choi,Dal-Ho Park,Do-Guwn Hwang,Hyung-Rho Yoon 대한의용생체공학회 2007 의공학회지 Vol.28 No.6

The study relates to achievement and analysis of 3-dimensional spatial pulse wave archived by a spatially arterial pulse diagnostic apparatus (SAPDA), wherein a pulse sensing part array consists of multiple hall devices and is located over a skin contacting part which consists of a magnetic material. When a radially arterial pulse is transferred to the magnetic material, which is contacted skin that results in changes in a magnetic field of the lower part of the pulse sensing part array, the changes in a magnetic field can be detected by the commercial Hall semiconductor device of the pulse sensing part array. Finally, according to development of SAPDA, the 3-dimensionally arterial pulse waveform can be measured noninvasively by detecting the changes of the magnetic field.

Clinicopathological features of the intraductal papillary neoplasms of the intrahepatic bile duct

Gi-Woong Jang,Shin Hwang,Yong-Joo Lee,Ki-Hun Kim,Kwang-Min Park,Chul-Soo Ahn,Deok-Bog Moon,Tae-Yong Ha,Gi-Won Song,Dong-Hwan Jung,Gil-Chun Park,Sung-Gyu Lee 한국간담췌외과학회 2012 한국간담췌외과학회지 Vol.16 No.4

Backgrounds/Aims: This study is intended to investigate the clinicopathological features of the intraductal papillary neoplasms of the intrahepatic bile duct (IPNB), especially focused on malignant changes. Methods: From the institutional database of liver resection cases (Asan Medical Center, University of Ulsan College of Medicine), 18 patients who met the definition of IPNB were selected. They had undergone liver resection between February 2002 and October 2006; thus, the follow-up period was more than 5 years. Results: Of the 18 patients, 11 patients were male. Their mean age was 61.3±6.7 years. There were no differences between the non-malignant and malignant lesions, in the comparison of the CEA levels (5.6±2.7 vs.12.6±31.1 ng/ml, p=0.439) and the CA19-9 levels (29.2±34.7 vs.31.9±30.2 ng/ml, p=0.871). The common radiologic findings were: intraductal growing mass in 10; bile duct dilatation in 6; and saccular duct dilatation in 2. Left and right hepatectomies were performed in 15 and 3, respectively. Five patients showed benign lesions of IPNB, and 13 patients revealed malignant lesions of intraductal papillary adnocarcinoma or cholangiocarcinoma. All 4 patients with benign lesions survived for a mean period of 53 months without recurrence. In 13 patients with the malignant lesions, 1-year, 3-year, and 5-year survival rates were 100%, 84.6%, and 59.2%, respectively. Conclusions: We concluded that intrahepatic IPNB is a rare type of biliary neoplasm which includes a histological spectrum, ranging from benign disease to invasive malignancy. The long-term survival was anticipated after complete curative resection. (Korean J Hepatobiliary Pancreat Surg 2012;16:138-141)