복벽 손상 백서에서 세가지 유형의 유착방지제의 효과

송형준(Hyung Jun Song),김종원(Jong Won Kim),박준석(Jun Seok Park),김용석(Yong Seok Kim),최유신(Yoo Shin Choi),김범규(Beom Gyu Kim),차성재(Sung Jae Cha),박성준(Sung Jun Park),장인택(In Taik Chang),박성일(Sung Il Park),박언섭(Eon Sub P 대한외과학회 2009 Annals of Surgical Treatment and Research(ASRT) Vol.77 No.1

Purpose: Postsurgical adhesion formation is a significant clinical problem within every surgical specialty. Several adhesion barriers have been developed in the form of solution, membrane or film in an attempt to solve these problems. The purpose of the present study is to compare the efficacy of antiadhesive agents in the prevention of postsurgical adhesion formation in a standardized rat adhesion model. Methods: We examined forty Sprague-Dawley rats, which is a cecal abrasion with partial peritonectomy model. Three treatment groups (Group Ⅰ: Film-type Surgiwrap<SUP>ⓡ</SUP>, Group Ⅱ: Solution-type Guardix-sol<SUP>ⓡ</SUP>, Group Ⅲ: Membrane-type Interceed<SUP>ⓡ</SUP>), each consists of 10 rats, and a control group of 10 rats were used by saline. Ten days after surgery, the rats were killed, and the levels of adhesion were graded. Immunohistochemical staining for microvessel density (CD34, MVD) and macrophage (ED1) were performed in adhesion tissue. Results: The peritoneum adhesion mean scores are as follows: control group: 2.2±0.78, Group Ⅰ: 1.0±1.06, Group Ⅱ: 0.9±0.99, Group Ⅲ: 0.6±0.84. All treatment groups showed significantly less peritoneum adhesion (P=0.006), while there was no significant difference in each group. The intraperitoneal organs adhesion mean scores are as follows: control group: 2.8±0.91, Group I: 2.6±1.06, Group Ⅱ: 1.4±0.84, Group Ⅲ: 1.0±0.81. Group Ⅰ had no significant difference about intraperitoneal organs adhesion with control group, but Group Ⅱ and Group Ⅲ showed less intraperitoneal organs adhesion. The mean numbers of microvessel density are as follows: control group: 42.5±4.83, Group Ⅰ: 40.8±6.53, Group Ⅱ: 30.9±6.15, Group Ⅲ: 15.60±4.37, from which there was a significant difference between Group Ⅱ and Group Ⅲ with control group (P<0.001). The mean numbers of macrophage are as follows: control group: 223.3±33.12, Group I: 211.25±10.96, Group Ⅱ: 171.60±23.96, Group Ⅲ: 147.0±12.22, from which there was a significant difference between Group Ⅱ and Group Ⅲ with control group (P<0.001). Conclusion: In our animal model, three different types of antiadhesive agents (Surgiwrap<SUP>ⓡ</SUP>, Guardix-sol<SUP>ⓡ</SUP>, Interceed<SUP>ⓡ</SUP>) were effective in adhesion prevention, but Surgiwrap<SUP>ⓡ</SUP> had less antiadhesive effect for intraperitoneal organs adhesion. Membrane-type Interceed<SUP>ⓡ</SUP> had a better effect for microvessel density (MVD) and macrophage than solution-type Guardix-sol<SUP>ⓡ</SUP>.

백서 모델에서 갑상선 절제술 후 Poloxamer/Alginate/CaCl₂ 유착방지제의 효과

김준호,이진호,이윤기,추보영,김남현,권성원,이영우,김광일 한국생체재료학회 2008 생체재료학회지 Vol.12 No.1

This study was conducted to compare the effectiveness of Poloxamer/alginate/CaCl₂ for reducing adhesion after thyroidectomy in a rat model. Tissue adhesion is one of the major causes of well known postsurgical complications, including patient's pain, functional obstruction and difficult preoperative surgery. Several adhesion barriers have been developed in the form of solution or membrane in an attempt to solve the postsurgical problems. However both types of tissue barriers have some limitations in their practical applications. In order to overcome these problems, a temperature- sensitive Poloxamer/alginate/CaCl₂ was prepared as an adhesion barrier. The sol-gel transition behavior was measured using a viscometer. And in vitro gel stability test was performed. The anti-adhesion effect was evaluated using a thyroidectomy model. Two week after surgery, the level of adhesion was graded from zero to two using a wholenumber system. And also toxicity, inflammation and the adhesion prevention effect were evaluated. The LCST (lower critical solution temperature) of the Poloxamer/Alginate/CaCl₂ was 25℃. The gel stability of Poloxamer was improved by adding cross-linked sodium Alginate/CaCl₂. The adhesion grade was significantly lower in the experimental group than in the control. From the results, Poloxamer/alginate/CaCl₂ is an excellent candidate material having highly effective anti-adhesion, low inflammatory response, and non-toxicity for clinical applications as a tissue adhesion barrier gel.

Adhesion Strength Prediction of CrAlN Coating on Al–Si Alloy (LM28): Fuzzy Modelling

Ibrahem Maher,Q. M. Mehran 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

In this study a method of predicting the adhesion strength of Chromium aluminum nitride (CrAlN) coating on Al–Si alloy(LM28) using fuzzy logic technique was introduced. LM28 was coated with CrAlN under dissimilar coating conditions. TheCrAlN coated substrates adhesion strength was determined by micro-scratch apparatus. The microstructure, topographicalanalysis and composition of selected coated substrates were characterized using scanning electron microscopy coupled withEnergy-dispersive X-ray spectroscopy. A fuzzy logic model was applied to predict the adhesion strength of CrAlN coating onLM28. RF power, DC power, nitrogen flow rate, and temperature based on the trained data achieved from the micro scratchtest were used as controllable process parameters. Then, three new experimental confirmation runs were conducted to verifythe results predicted via the Fuzzy model. The predicted adhesion strength was equated with measured data. The maximumprediction error was 5.2%, while the average prediction error was 3.5%. Finally, prediction resulted in the improvement ofsurface hardness value from 0.9 GPa to 4.5 GPa, signifying an enhancement by 5 times.

탄소섬유쉬트-콘크리트 부착이음의 부착 모델

조정래(Cho Jeong-Rae),조근희(Cho Keunhee),박영환(Park Young-Hwan),박종섭(Park Jong-Sup) 대한토목학회 2006 대한토목학회논문집 A Vol.26 No.2A

이 연구는 탄소섬유쉬트-콘크리트 부착이음 실험 결과로부터 국부적인 부착모델(부착응력-미끄럼 모델)을 결정하는 방법을 제안하고, 실제 실험 결과와 비교하여 이러한 부착 조건에 적용 가능한 부착모델을 제시한다. 부착모델의 형상은 임의의 곡선 형태를 고려할 수 있도록 다중선형곡선(multi-linear curve)으로 가정하였으며, 수치적인 방법으로 부착이음의 해를 계산하여 실험 결과와 오치를 최소화하는 방법으로 부착모델을 결정하였다. 이중선형곡선(bilinear curve)을 도입한 부착모델 역시 최적화를 수행하여 다중선형모델과 비교하였다. 최적화의 대상은 동일 조건의 부착모델에 대해 여러 실험체로부터 구한 극한하중-부착길이 곡선과 개별 실험체의 하중-변위 곡선이다. 최적화를 위한 정식화는 physical programming을 사용하였으며 최적화 방법은 유전알고리즘(genetic algorithm)을 이용하였다. In this study, a method determining the local bond-slip model from pure shear test results of CFRP sheet-concrete adhesive joints is proposed and local bond-slip models are presented. Adhesive joints with a specific bond-slip model, which is assumed as multi?linear curve in order to represent arbitary function, are solved numerically. The difference between the solution and test results are minimized for finding the bond-slip model. The model with bilinear curve is also optimized to verity the improvement of multi-linear model. The selected test results are ultimate load-adhesive length curves from a series of adhesive joints and load-displacement curves for each joint. The optimization problem is formulated by physical programming, and the optimized bond-slip model is found using genetic algorithm.

Hyaluronic Acid와 Sodium Carboxymethyl Cellulose 혼합용액(Guardix-solⓇ)의 심장막유착 방지 효과에 관한 연구

이송암,김진식,김준석,황재준,이우성,김요한,최양규,지현근 대한흉부외과학회 2010 Journal of Chest Surgery (J Chest Surg) Vol.43 No.6

Background: This study was designed to evaluate the efficacy of a mixture of hyaluronic acid and sodium carboxymethyl cellulose (Guardix-solⓇ) on experimental pericardial adhesion. Material and Method: Thirty rats were divided into 2 groups of 15 rats each and pericardial mesothelial injury was induced during surgery by abrasion. In the control group, blood and normal saline were administered into pericardium; in the test group, blood and HA-CMC solution were administered. Pericardial adhesions were evaluated at 2 weeks (n=5), 4 weeks (n=5), and 6 weeks (n=5) after surgery. The severity of adhesions was graded by macroscopic examination, and the adhesion tissue thickness was analyzed microscopically with Masson trichrome stain and an image processing program. Result: The test group had significantly lower macroscopic adhesion scores (2.9±0.6 : 3.9±0.4, p<0.000) compared with the control group. For microscopic adhesion tissue thickness, the test group had lower scores compared with the control group, but this difference was not statistically significant (91.73±49.91 : 117.67±46.4, p=0.106). Conclusion: We conclude that an HA-CMC solution (Guardix-solⓇ) reduces the formation of pericardial adhesions in this animal model. 배경: 심장막유착에 hyaluronic acid와 sodium carboxymethyl cellulose 혼합용액(HA-CMC solution,Guardix-solⓇ)의 유착방지 효과를 평가하기 위해 본 연구를 시행하였다. 대상 및 방법: 30마리의 흰쥐를 각각 15마리씩 2그룹으로 나누었으며 기계적 마찰을 통해 심장막 중피 손상을 유발시켰다. 대조군은 혈액과 생리식염수를, 실험군은 혈액과 HA-CMC 혼합용액을 심장막공간에 주입하였다. 수술후2주, 4주, 6주에 5마리씩 심장막유착의 정도를 평가하였다. 유착의 정도를 육안으로 평가하였으며, 유착조직의 두께는 Masson trichrome염색과 영상처리프로그램을 통해 현미경적 분석을 시행하였다. 결과: 육안적검사상 실험군에서 유착점수가 대조군에 비해 유의하게 낮았다(2.9±0.6 : 3.9±0.4, p<0.000). 실험군에서 유착조직두께는 대조군에 비해 낮았으나 통계적으로 유의하지는 않았다(91.73±49.91 :117.67±46.4, p=0.106). 결론: 실험동물 모델에서 HA-CMC용액(Guardix-solⓇ)의 유착형성을 감소시키는것을 관찰하였다.

인장하중하에서의 고분자/거친금속 계면의 파손에 대한 비교연구 II: 접착모델

이호영,김성룡,Lee Ho-Young,Kim Sung-Ryong 한국재료학회 2005 한국재료학회지 Vol.15 No.1

Copper based leadframe sheets were immersed in two kinds of hot alkaline solutions to form brown-oxide or blackoxide layer on the surface. The oxide-coated leadframe sheets were molded with epoxy molding compound (EMC). After post mold curing, the oxide-coated EMC-leadframe joints were machined to form sandwiched double-cantilever beam (SDCB) specimens. The SDCB specimens were used to measure the fracture toughness of the EMC/leadframe interfaces under quasi-Mode I loading conditions. After fracture toughness testing, the fracture surface were analyzed by various equipment to investigate failure path. An adhesion model was suggested to explain the failure path formation. The adhesion model is based on the strengthening mechanism of fiber-reinforced composite. The present paper deals with the introduction of the adhesion model. The explanation of the failure path with the proposed adhesion model was introduced in the companion paper.

보 접착 모델을 이용한 게코 접착 시스템의 접착 메커니즘에 대한 연구

김원배,조맹효,Kim, Won-Bae,Cho, Maeng-Hyo 한국전산구조공학회 2010 전산구조공학 Vol.23 No.4

게코 접착 시스템은 보(beam)의 형상을 가지는 seta와 접착패드 역할을 하는 spatula로 구성된다. 본 논문에서는 보 접착 모델(ahhesive beam contact model)을 사용하여 게코(gecko) 접착 시스템의 접착 메커니즘의 해석을 수행한다. 보 접착 모델은 접촉면에서 불균일한 응력 분포를 가지는 특징이 있으며, 접촉면에서의 최대 인장 응력(tensile stress)에 의하여 접착/분리 메커니즘이 결정된다. 접착패드 역할을 하는 spatula는 최대 인장응력을 감소시키는 역할을 하며, 이로 인해 접착력이 증가한다. 역방향 하중에 대해서는 spatula에 의하여 최대 압축 응력(compressive stress)이 감소하며, 이러한 현상에 의하여 접착력과 분리력의 비대칭성이 발생한다. 본 연구에서는 보 접착 모델의 해석을 위해 유한요소법(Finite Element Method)을 사용되며, spatula effect를 위한 해석 결과가 제시된다. Gecko adhesion system consists of beam-shaped seta and spatula which has the role of adhesive pad. In this paper, adhesion mechanism of gecko adhesion system is performed by using adhesive beam contact model. this model has a feature of non-uniform stress profile on the contact surface and adhesion/detachment mechanism is determined by the tensile stress of the contact region. a spatula tip pad has the role of reduction of maximum tensile stress and adhesive force is increased due to this effect. As for a reverse loading case, maximum compressive stress drops by the spatula effect and this cause unsymmetric loading conditions between adhesion and detachment forces. In this study, finite element method is used for the analysis of adhesive beam contact model and the results for spatula effect are presented.

Creep simulation of adhesively bonded joints using modified generalized time hardening model

Mohammad Ali Saeimi Sadigh 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.4

Creep behavior of double lap adhesively bonded joints was investigated using experimental tests and numerical analysis. Firstly, uniaxial creep tests were carried out to obtain the creep characteristics and constitutive parameters of the adhesive at different stress and temperature levels. Generalized time hardening model was used to predict the creep behavior of the adhesive. This model was modified to simulate the creep behavior at different stress and temperature levels. Secondly, the developed model was used to simulate the creep behavior of bonded joints using finite element based numerical analysis. Creep deformations of the joints were measured experimentally and good agreement was observed in comparison with the results obtained using numerical simulation. Afterward, stress redistribution due to the creep along the adhesively bonded joint was obtained numerically. It was observed that temperature level had a significant effect on the stress redistribution along the adhesive thickness.

가토 모델에서 복강경 수술 시 전기방사 나노섬유 유착방지제의 효과 및 안전성

이영우(Young Woo Lee),추보영(Boyoung Chu),이윤기(Yun Gee Lee),김남현(Nam Hyun Kim),김준호(Jun Ho Kim),김광일(Kwang Il Kim),권성원(Sung Won Kwon) 대한외과학회 2009 Annals of Surgical Treatment and Research(ASRT) Vol.76 No.2

Purpose: Most recently developed anti-adhesive membranes are not suitable for laparoscopic surgery due to weak mechanical properties or adhesive characteristics. To overcome these problems, we prepared electrospun bioabsorbable nanofibrous poly (lactic-co-glycolic acid)-based membranes as an adhesion barrier. We evaluated the efficacy and safety of this material for laparoscopic surgery in a rabbit model. Methods: A standardized laparoscopic surgical trauma was made on the rabbit’s uterine horn and adjacent abdominal wall to induce adhesion formation. The injured uterus was covered by a nanofibrous barrier or it was left untreated (the negative control group) (each group: n=14). To evaluate acute toxicity of this material, blood sampling was made 3 and 7 days after laparoscopic surgery to check liver and renal function. Three weeks after laparoscopy, a second look laparoscopy was performed and the adhesions were scored according to Blauer"s scoring system. Tissue between abdominal wall and uterus was obtained to examine microscopically. Liver, kidney and uterus were harvested to examine chronic toxicity. Results: 36.4% of the nanofiber treatment group and 70% of the untreated control group showed severe adhesions (grade>3) after laparoscopic surgery but failed to get a statistical significance (P=0.198). Acute and chronic toxicity induced by this material were not noted in the blood and tissue exam. Conclusion: This study showed that nanofiber barrier seems to be a novel resorbable biomaterial for the reduction of postoperative adhesions. Easy placement and handling of this material make these membranes potentially successful candidates for laparoscopic surgery. But further study is needed to get a statistical significance.

Failure behavior of inclined thick adhesive joints with manufacturing defect

Tsinuel Nurilligne Geleta,우경식,Douglas S. Cairns,Daniel Samborsky 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.5

In this paper, numerical model of thick adhesive inclined joints has been prepared and validated against experimental test to study the effect of manufacturing defect on the joint strength. The inclined joint was made up of two laminate webs attached to a wedge by a layer of adhesive. Tensile tests were conducted on many thick adhesive joint specimens with two different geometries. One half of the symmetric test specimen was then modeled using finite element analysis in which cohesive zone modeling (CZM) was used to simulate the initiation and propagation of joint fracture. The progressive fracture through the adhesive layer and along adhesive-laminate interface was carefully examined. Based on inspection of the experimental test specimen, potential manufacturing defect types and locations were incorporated in the finite element model. The reduction in strength due to these manufacturing defects was used to predict the most critical flaw type in thick inclined joints. The differences between the “flawless” numerical model and the experimental test specimen was explained when these manufacturing defects were incorporated. The results were found to be consistent with the experimental tests.