• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.75-78
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• 2003

This study is to investigate the probability to develop the AE Water-reducing agent which can decrease the bleeding by mixing melamine type super-plasticizer(SP) and methyl cellulose(MC) viscosity agent. According to the result, as the mixing ratio of melamine type SP and MC viscosity agent increases, the bleeding is reduced due to a increase of the air content. When the mixing ratio of melamine type SP and MC viscosity agent is 1:2 and 1;3 at the water content of 165kg/$m^3$ and 175kg/$m^3$ respectively, slump and air content are satisfied and bleeding is reduced to some extent, so this is determined as the mixing ratio of AE water reducing agent for reduction of bleeding. It is prove that the developed AE water reducing agent for reduction of bleeding can reduce the amount of bleeding and prohibit the plastic shrinkage crack by slowing down the bleeding speed. Compressive strength of hardened concrete does not make any difference in comparison with plain concrete.

• Journal of Periodontal and Implant Science
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• 제25권2호
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• pp.290-300
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• 1995

Tooth mobility is one of the most important clinical parameters in examination, diagnosis, prognosis and treatment planning procedure. In order to determine the differences of tooth mobility according to radiographical bone level, clinical root length, clinical crown/root ratio, and bleeding on probing, 90 male adults with periodontal disease and 10 male adults with periodontal health($25{\sim}45$ years old) were selected through clinical examinations including occlusal relationship, probing depth, attachment level, and bleeding on probing. On the mandibular anterior teeth, standard periapical radiographs were taken, and tooth mobility was measured by Periotest(Siemens Co., Germany). The radiographic bone level of individual tooth was evaluated as coronal 1/3, middle 1/3, and apical 1/3 to anatomical root length, and clinical crown length from incisal edge to bone level and clinical root length from bone level to root apex were measured with Boley gauge, and subsquently clinical crown/root ratio was calculated. The difference of tooth mobility(Periotest value) according to radiographical bone level, clinical root length, clinical crown/root ratio, and bleeding on probing was statistically analyzed by unpaired Student t-test. Tooth mobility was significantly higher in bleeding group than non-bleeding group on probing in the teeth radiographic bone level of middle 1/3, with clinical root length longer than 6mm, and with clinical crown/root ratio over 0.3(p<0.01). But there was no statistical difference in tooth mobility between bleeding group and non-bleeding group on probing in the teeth with radiographic bone level of apical 1/3, with short clinical root length less than 5mm, and with clinical crown/root ratio under 0.2(p>0.05). The results note that the tooth mobility depends on clinical root length, clinical crown/root ratio and gingival inflammation, and in the teeth with relatively good alveolar bone support gingival inflammation is one of the most important factors that affect tooth mobility.

• International Journal of Oral Biology
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• 제45권2호
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• pp.51-57
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• 2020

Thromboelastography or rotational thromboelastometry, is being increasingly utilized in cardiac surgery of late. However, it is an indirect test and is not available in all centers. Low fibrinogen levels before and after cardiopulmonary bypass (CPB) have been described to be associated with postoperative bleeding in cardiac surgery. This study explored the usefulness of reduction ratio of the fibrinogen levels before CPB (preCPB) and after CPB (postCPB) in predicting postoperative hemorrhage. A retrospective, observational study of adult patients who underwent cardiac surgery with CPB between February 2014 and January 2016 was conducted, which included a total of 264 patients. The fibrinogen levels were measured twice, preCPB and postCPB, and the fibrinogen reduction ratio was acquired [(preCPB - postCPB)/preCPB]. Postoperative blood loss, which was defined as the blood collected from the chest drain for 12 hours following arrival at the intensive care unit, was considered severe if it was more than 1,000 mL. A multivariate analysis showed that fibrinogen reduction ratio, sex, and postCPB platelet count were significantly associated with severe postoperative bleeding. However, the pre- and postCPB fibrinogen levels were not significantly associated with severe bleeding. Furthermore, a fibrinogen reduction ratio of > 41.3% was independently associated with postoperative severe bleeding, with an odds ratio of 3.472 (1.483-8.162). These results suggest that the reduction ratio of pre- and postCPB fibrinogen levels may be utilized in predicting postoperative bleeding.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제18권1호
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• pp.30-38
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• 2015

Purpose: The aims of our study were to evaluate the blood urea nitrogen to creatinine ratio (BUN/Cr ratio) for distinguishing between an upper and lower gastrointestinal bleeding (GIB), and differentiating between the two most common causes of upper gastrointestinal bleeding (UGIB) presenting with melena in children. Methods: Retrospective data of patients with GIB presenting with melena were analyzed. The data from 60 cases were reviewed including demographics, laboratory findings, diagnostic modalities and results, treatments, and transfusions. Results: Among the 60 cases, UGIB and lower gastrointestinal bleeding (LGIB) were found in 35 cases (58.3%) and 14 cases (23.3%), respectively. The two common causes of UGIB were varices (37.1%), and peptic ulcer diseases (PUD) (31.4%). The BUN/Cr ratio of 30 or greater was higher in UGIB than LGIB (odds ratio [OR], 6.9; 95% confidence interval [95% CI], 1.3-37.2). In UGIB, the BUN/Cr ratio of the varices group was higher than that of the PUD group (p=0.015). The OR for the BUN/Cr ratio appeared as 1.2 per unit increase in the varices group than the PUD group (95% CI, 1.03-1.3). There was no difference between the PUD group and Meckel's diverticulum group. Conclusion: The BUN/Cr ratio was not uneven in differentiating UGIB from LGIB of children with melena in our study. This suggests that BUN/Cr ratio should be interpreted carefully.

• 토지주택연구
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• 제12권4호
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• pp.127-137
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• 2021

그라우팅 공법은 지반 내 토목구조물 활용 시 지반 강도특성을 증진시키거나 지하공간 활용 시 차수효과를 위하여 활발하게 적용되고 있다. 최근에는 그라우팅 기밀특성을 향상시키기 위하여 벤토나이트가 시멘트 재료와 함께 활용되고 있다. 이러한 벤토나이트-시멘트 그라우팅 재료의 원활한 주입을 위해서는 주입재료의 배합비율에 따른 특성을 사전에 파악하는 것이 중요하다. 본 연구에서는 그라우팅 재료로 주로 활용되고 있는 1종 보통 포틀랜드 시멘트와 벤토나이트를 이용하여 물/시멘트 배합비율 및 벤토나이트 함량에 따른 점성도 및 블리딩 발생비율을 분석하였다. 실험결과, 물/시멘트 배합비율이 감소하거나 벤토나이트 함량이 증가할수록 점성도는 급격히 증가하고 블리딩 비율은 감소하는 반비례 경향을 보였다. 또한, 적합한 재료 선정 기준에 따라 물/시멘트 배합비율 따른 적용가능한 벤토나이트 함량을 선정하였다. 본 연구에서 분석한 벤토나이트-시멘트 그라우팅 재료의 평가 결과는 향후 지반 내 적합한 그라우팅 재료 선정을 위하여 유용하게 활용될 수 있을 것으로 기대된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.593-596
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• 2008

콘크리트의 블리딩은 재료분리의 일종으로서 콘크리트 품질뿐만 아니라 내구성을 저하시키는 원인으로 작용한다. 본 연구에서는 콘크리트 블리딩에 영향을 미칠 것으로 예상되는 시멘트 및 믹싱시간의 두 요인의 변화에 따른 특성을 파악하여 블리딩 제어기술 확보를 위한 기초자료를 제공하고자 한다.연구결과에 의하면, 믹싱시간이 증가할수록 블리딩율도 증가하는 추세를 나타내고 있었다. 블리딩양(믹싱시간 90초)은 시멘트 특성에 의한 차이가 뚜렷하게 나타나고 있었으며, 콘크리트 특성값(블리딩율, 슬럼프 및 재령 3일 압축강도)은 믹싱시간과 비례적인 관계가 있었다. 또한, 슬럼프 손실율과 믹싱시간은 반비례적인 관계가 존재하였고, 압축강도값은 초기재령에서만 믹싱시간에 의한 영향을받고 있었다.향후, 최적 믹싱시간 도출을 위한 다양한 검토가 필요할 것으로 판단된다.

• Journal of Gastric Cancer
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• 제22권1호
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• pp.47-55
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• 2022

Purpose: The use of direct oral Xa inhibitors (DXaIs) to prevent venothrombotic events is increasing. However, gastrointestinal bleeding, including that related to endoscopic resection, is a concern. In this study, we evaluated bleeding and coagulation times during the perioperative period of gastric endoscopic submucosal dissection (ESD). Materials and Methods: Patients who consecutively underwent gastric ESD from August 2016 to December 2018 were analyzed. Bleeding rates were compared among the 3 groups (antiplatelet, DXaIs, and control). DXaI administration was discontinued on the day of the procedure. Prothrombin time (PT), activated partial thromboplastin time, and the ratio of inhibited thrombin generation (RITG), which was based on dilute PT, were determined before and after ESD. Results: During the study period, 265 gastric ESDs were performed in 239 patients, where 23 and 50 patients received DXaIs and antiplatelets, respectively. Delayed bleeding occurred in 17 patients (7.4%) and 21 lesions (7.1%). The bleeding rate in the DXaI group was significantly higher than that in the other groups (30.4%, P<0.01), and the adjusted odds ratio of bleeding was 5.7 (95% confidence interval, 1.4-23.7; P=0.016). In patients using DXaIs, there was a significant (P=0.046) difference in the median RITG between bleeding cases (18.6%) and non-bleeding cases (3.8%). Conclusions: A one-day cessation of DXaIs was related to a high incidence of bleeding after gastric ESD, and monitoring of residual coagulation activity at trough levels might enable the predicted risk of delayed bleeding in patients using DXaIs.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.65-68
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• 2003

This study is intended to look into the influence of environment and construction factor on bleeding of concrete. According to the results, as wind is light, relative humidity is high and temperature is low, the amount of bleeding increases greatly, and evaporation speed is influenced greatly by order of wind, temperature and humidity. As the properties of bleeding by construction factor, the amount of bleeding increases with an increase of placing thickness, but the bleeding ratio, the amount of bleeding per unit volume, increases with a decrease of the placing thickness. Bleeding speed is fastest at about 90 minute after placing concrete. Also, as wind is light, relative humidity is high, temperature is low and the placing thickness is thick, bleeding speed grow faster.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문 발표회
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• pp.69-72
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• 2003

This study is intended to investigate the fundamental properties of concrete which AE water reducing agent for reduction of bleeding is used, and the properties of bleeding reduction. According to the results, when the adding ratio of AE water reducing agent for reduction of bleeding increases, a range of normal fluidity and aimed air content arc satisfied, setting time is faster than that of normal AE water reducing agent. And bleeding amount decreases, bleeding speed is highest between 60 and 90 min, and sinking depth increases drastically in 60 min. When, AE water reducing agent for reduction of bleeding is added, compressive strength shows a slight variation by air content, but there is not a large influence by addition of AE water reducing agent for reduction of bleeding. Synthetically, it proves that AE water reducing agent for reduction of bleeding satisfies aimed air content in the range of normal slump and can reduce only bleeding without quality variation of compressive strength.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.69-72
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• 2003

This study is intended to investigate the fundamental properties of concrete which AE water reducing agent for reduction of bleeding is used, and the properties of bleeding reduction. According to the results, when the adding ratio of AE water reducing agent for reduction of bleeding increases, a range of normal fluidity and aimed air content are satisfied, setting time is faster than that of normal AE water reducing agent. And bleeding amount decreases, bleeding speed is highest between 60 and 90 min, and sinking depth increases drastically in 60 min. When. AE water reducing agent for reduction of bleeding is added, compressive strength shows a slight variation by air content, but there is not a large influence by addition of AE water reducing agent for reduction of bleeding. Synthetically, it proves that AE water reducing agent for reduction of bleeding satisfies aimed air content in the range of normal slump and can reduce only bleeding without quality variation of compressive strength.