• Title/Summary/Keyword: normal adhesion

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Basic Study on Fiber Composite Panel Production for Impact·Blast Resistant (방호·방폭 보강용 복합섬유 패널 제작을 위한 기초연구)

  • Kim, Woonhak;Kang, Seokwon;Yun, Seunggyu
    • Journal of the Society of Disaster Information
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    • v.11 no.2
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    • pp.235-243
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    • 2015
  • The methods to improve the protection and explosion-proof performance of concrete structures include the backside reinforcement or concrete material property improvement and the addition of structural members or supports to increase the resistance performance, but they are inefficient in terms of economics and structural characteristics. This study is about the basic study on the fiber composite panel cover, and the nano-composite material and adhesive as the filler, to maximize the specific performance of each layer and the protection and explosion-proof performance as the composite panel component by improving the tensile strength, light weight, adhesion and fire-proof performances. The fiber composite panel cover (aramid-polyester ratios of 6:4 and 6.5:3.5) had a 2,348 MPa maximum tensile strength and a 1.8% maximum elongation. The filler that contained the nano-composite material and adhesive had a 4 MPa maximum tensile shear adhesive strength. In addition, the nano-composite filler was 30% lighter than the normal portland cement

An Experimental Study on the Property of the Concrete with Glass Hollow Micro Sphere (유리질중공미소구체를 사용한 콘크리트의 특성에 관한 실험적 연구)

  • Kim, Sang-Heon;Kim, Se-Hwan;Park, Young-Shin;Jeon, Hyun-Gyu;Seo, Chee-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.3
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    • pp.160-166
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    • 2014
  • In this research, as a measure of reducing energy lost through external wall, we used Glass Hollow Micro Sphere (HMS) to improve insulation performance to structural concrete. The following is a result of experimenting concrete using HMS. As usage of HMS, decrease in slump arose and it is judged as a need of using superplasticizer. Replacement ratio increasing more and more, amount of air showed tendency to decrease and compressive strength decreased for interfacial adhesion had not been formed. as replacement ratio and unit volume decreased. It appears that thermal conductivity decreased about 30.0~46.5 percent as compared with normal weight concrete.

A Experimental Study on the Property of Lightweight Aggregate Concrete Using Hollow Micro Sphere (유리질 중공 미소 구체를 사용한 경량골재콘크리트의 특성에 관한 실험적 연구)

  • Kim, Sang Heon;Kim, Se Hwan;Park, Young Shin;Jeon, Hyun Gyu;Seo, Chee Ho
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.2
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    • pp.177-183
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    • 2015
  • In this study, the thermal conductivity, physical and mechanical properties of lightweight aggregate concretes with hollow micro sphere(HMS) are experimentally examined as a basic research for the development of structural insulation concrete. As the results of this experiment, in the case of concrete mixed with HMS, the value of slump has been reduced, so it is found that the dosage of superplasticizer should be increased. As the replacement ratio of HMS increases, it has shown that the compressive strength is somewhat decreased due to the low interfacial adhesion strength of HMS. But the thermal conductivity is found to be greatly improved with the replacement ratio of HMS increases, the thermal conductivity of HMS shows the lower value of 68% at lightweight aggregate concrete and 32% of normal concrete. Also it is found that the compressive strength is decreased and thermal conductivity is increased as the water-cement ratio increases. The most outstanding for insulation performance is observed when using 20% of HMS and 50% of water-cement ratio.

Effects of Mokdanpijihwang-tang on gastric mucosal damage in mice (목단피지황탕(牧丹皮地黃湯)이 위점막손상(胃粘膜損傷)에 미치는 영향(影響))

  • Park, Seong-Sik;Lee, Ji-Young
    • Journal of Sasang Constitutional Medicine
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    • v.12 no.2
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    • pp.171-183
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    • 2000
  • 1. Back ground and purpose An experimental study has done to examine the effect of defense and cure gastric mucasal damage of Mokdan-pijihwang-tang. 2. Methods Mice had intragastric injected with MJ extract before indomethacin treatment which induces homorrhage infarct and erosion artificially. Degree of lipid peroxidation, general morphology, change of mucous cell, the distribution of PNA, ICAM and distribution of apoptotic cell were objected. (Abbreviation) MJ : Mokdanpijihwang-tang, PNA : Peanut Agglutinin, ICAM : Intercellular Adhesion Molecule 3 Results 1) The degree of lipid peroxidation in INDO-group had increased conspicuously than control group. But the degree of lipid peroxidation in MJ-group had decreased than INDO-group and these decline had probability. 2) After indomethacin treatment, hemorrhage infarct and erosion had increased in stomach body. But in MJ-group, the configuration is normal, except the group intragastric injected with MJ extract at hour 24 before indomethacin treatment. 3) Surface mucous cell and neck mucous had disappeared in INDO-group. But in MJ-group tormal distribution had shown like control group except the group intragastric injected with MJ extract at hour 24 before indomethacin treatment. 4) PNA positive reaction had not shown in INDO-group. But medium PNA positive reaction had shown In Mj-group. 5) ICAM positive reacted cell had shown in INDO-group. The decrease of ICAM positive cell were shown than INDO-group. 6) A number of apoptotic cell was distributed in hemorrhagic erosion. A few number of apoptotic cell was distributed in MJ-group except some surface mucous. 4. Conclusion These results suggest that MJ has an effect on cure of gastric mucosal damage.

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Small Intestine Resection and Anastomosis for Epiploic Foramen Entrapment of a Horse (말의 그물막구멍포착 교정을 위한 소장 절제 및 문합 1례)

  • Hwang, Hye-shin;Park, Chull-gyu;Hwang, Jun-seok;Chun, Yong-woo;Han, Janet H.;Lee, Inhyung
    • Journal of Veterinary Clinics
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    • v.32 no.4
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    • pp.374-379
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    • 2015
  • A 10-year-old gelding Warmblood weighing 560 kg was referred to J&C Equine Hospital with the history of hyperpnea, depression, pawing, and rolling for 7 hours. According to the results of clinical and ultrasound examination, it was considered that intestines were distended with thickened wall. The horse had been treated with lactated Ringers' solution (14 L, IV), flunixin meglumine (1.1 mg/kg, IV), and mineral oil (1 L, PO), but he did not show any responses to those treatments. Exploratory laparotomy was performed and identified incarcerated small intestine through the epiploic foramen. The horse received resection and anastomosis of the entrapped small intestine. After surgery, the horse was treated with intensive postoperative care of fluid therapy (5 L with 20 mEq/L KCl, every 2 hours), flunixin meglumine (1.1 mg/kg, IV, sid), antibiotics (penicillin 22,000 IU/kg, IV, qid and gentamicin 6.6 mg/kg, IV, sid), lidocaine constant rate infusion (bolus 1.3 mg/kg over 15 minutes then 0.05 mg/kg/minute), common nutritional supplements, nasogastric intubation every 2 hours and trunk bandage. Postoperative feeding program had started with small amount of hay every 4 hours and gradually increased to normal amount till 5 days. At 77 days after surgery, he showed sudden outbreak of colic and was euthanized. The causes of colic were small intestinal strangulation by passing through the mesenteric rents and postoperative adhesion between small intestines. According to the results, it is recommended to perform perioperative intensive care of horse with colic and to use several methods to prevent adhesions during abdominal surgery of horses.

Polycaprolactone Nanofiber Mats Fabricated Using an Electrospinning Process Supplemented with a Chemical Blowing Agent (전기방사공정과 발포제를 이용한 Polycaprolactone 나노섬유 지지체 제작)

  • Kim, Geun-Hyung;Yoon, Hyeon;Lee, Haeng-Nam;Park, Gil-Moon
    • Polymer(Korea)
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    • v.32 no.5
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    • pp.458-464
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    • 2008
  • A successful scaffold should have a highly porous structure and good mechanical stability. High porosity and appropriate pore size provide structural matrix for initial cell attachment and proliferation enabling the exchange of nutrients between the scaffold and environment. In this paper the highly porous scaffold of poly(${\varepsilon}$-caprolactone) electrospun nanofibers could be manufactured with an auxiliary electrode and chemical blowing agent (BA) under several processing conditions, such as the concentration of PCL solution, weight percent of a chemical blowing agent, and decomposition time of a chemical blowing agent. To attain stable electrospinnability and blown nanofiber mats having high microporosity and large pore, a processing condition, 8wt% of PCL solution and 0.5wt% of a chemical blowing agent under $100^{\circ}C$ and decomposition time of $2{\sim}3\;s$, was used. The growth characteristic of human dermal fibroblasts cells cultured in the mats showed the good adhesion and proliferation on the blown mat compared to a normal electrospun mat.

Structural Adjustment of In-Situ Surface-Modified Silica Matting Agent and Its Effect on Coating Performance

  • Xu, Qingna;Ji, Tongchao;Tian, Qingfeng;Su, Yuhang;Niu, Liyong;Li, Xiaohong;Zhang, Zhijun
    • Nano
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    • v.13 no.12
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    • pp.1850137.1-1850137.9
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    • 2018
  • A series of silica surface-capped with hexamethyldisilazane (denoted as $H-SiO_2$) were prepared by liquid-phase in-situ surface-modification method. The as-obtained $H-SiO_2$ was incorporated into acrylic amino (AA) baking paint to obtain AA/$H-SiO_2$ composite extinction paints and/or coatings. $N_2$ adsorption-desorption tests were conducted to determine the specific surface area as well as pore size and pore volume of $H-SiO_2$. Moreover, the effects of $H-SiO_2$ matting agents on the physical properties of AA paint as well as the gloss and transmittance of AA-based composite extinction coatings were investigated. Results show that $H-SiO_2$ matting agents possess a large specific surface area and pore volume than previously reported silica obtained by liquid-phase method. Besides, they have better dispersibility in AA baking paint than the unmodified silica. Particularly, $H-SiO_2$ with a silica particle size of $6.7{\mu}m$ and the dosage of 4% (mass fraction) provides an extinction rate of 95.2% and a transmittance of 79.3% for the AA-based composite extinction coating, showing advantages over OK520, a conventional silica matting agent. Along with the increase in the silica particle size, $H-SiO_2$ matting agents cause a certain degree of increase in the viscosity of AA paint as well as a noticeable decrease in the gloss of the AA-based composite extinction coating, but they have insignificant effects on the hardness and adhesion to substrate of the AA-based composite coatings. This means that $H-SiO_2$ matting agents could be well applicable to preparing low-viscosity and low-gloss AA-based matte coatings.

Feasibility Assessment of Physical Factors of Rectal Cancer Short-Course Chemoradiotherapy with Delayed Surgery

  • Koo, Jihye;Chung, Mijoo;Chung, Weon Kuu;Jin, Sunsik;Kim, Dong Wook
    • Progress in Medical Physics
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    • v.29 no.4
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    • pp.143-149
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    • 2018
  • To verify the correlations between the clinical outcomes and physical factors of short-course chemoradiotherapy (SCRT) and long-course chemoradiotherapy (LCRT) with delayed surgery in patients with rectal cancer. Seventy-two patients with rectal cancer were enrolled in this study. Nineteen patients were treated with SCRT (25 Gy, 5 fractions) by intensity-modulated radiation therapy (IMRT), and 53 patients were treated with LCRT (50.4 Gy, 28 fractions) by three-dimensional conformal radiation therapy (3DCRT). Various physical factors for the target and organs at risk (OARs) were calculated to compare the clinical outcomes. The organ equivalent dose (OED) and lifetime attributable risk (LAR) of bowels and bladders were similar between the SCRT and LCRT groups, whereas the values of femurs were higher in the LCRT group. The equivalent uniform dose and normal tissue complication probability were higher in the LCRT than the SCRT group for most organs. Treatment complications, including anastomotic leakage, bowel adhesion, and hematologic toxicity, were not significantly different between SCRT and LCRT groups. CIs were $0.84{\pm}0.2$ and $0.61{\pm}0.1$ for SCRT and LCRT, respectively. The CVIs were $1.07{\pm}0.0$ and $1.10{\pm}0.1$, and the HIs were $0.09{\pm}0.0$ and $0.11{\pm}0.1$ for SCRT and LCRT, respectively. The sphincter-saving rates were 89.5% and 94.3% for SCRT and LCRT, respectively. The complete pathologic remission rates were 21.1% and 13.2%, and the down-staging rates were 47.4% and 26.4% for SCRT and LCRT, respectively. SCRT with IMRT is comparable to conventional LCRT in both physical indexes and clinical outcome. The preoperative SCRT, compensated by IMRT, is an effective and safe modality.

Disorders of Secondary Neurulation : Mainly Focused on Pathoembryogenesis

  • Yang, Jeyul;Lee, Ji Yeoun;Kim, Kyung Hyun;Wang, Kyu-Chang
    • Journal of Korean Neurosurgical Society
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    • v.64 no.3
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    • pp.386-405
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    • 2021
  • Recent advancements in basic research on the process of secondary neurulation and increased clinical experience with caudal spinal anomalies with associated abnormalities in the surrounding and distal structures shed light on further understanding of the pathoembryogenesis of the lesions and led to the new classification of these dysraphic entities. We summarized the changing concepts of lesions developed from the disordered secondary neurulation shown during the last decade. In addition, we suggested our new pathoembryogenetic explanations for a few entities based on the literature and the data from our previous animal research. Disordered secondary neurulation at each phase of development may cause corresponding lesions, such as failed junction with the primary neural tube (junctional neural tube defect and segmental spinal dysgenesis), dysgenesis or duplication of the caudal cell mass associated with disturbed activity of caudal mesenchymal tissue (caudal agenesis and caudal duplication syndrome), failed ingression of the primitive streak to the caudal cell mass (myelomeningocele), focal limited dorsal neuro-cutaneous nondisjunction (limited dorsal myeloschisis and congenital dermal sinus), neuro-mesenchymal adhesion (lumbosacral lipomatous malformation), and regression failure spectrum of the medullary cord (thickened filum and filar cyst, low-lying conus, retained medullary cord, terminal myelocele and terminal myelocystocele). It seems that almost every anomalous entity of the primary neural tube may occur in the area of secondary neurulation. Furthermore, the close association with the activity of caudal mesenchymal tissue in secondary neurulation involves a wider range of surrounding structures than in primary neurulation. Although the majority of the data are from animals, not from humans and many theories are still conjectural, these changing concepts of normal and disordered secondary neurulation will provoke further advancements in our management strategies as well as in the pathoembryogenetic understanding of anomalous lesions in this area.

Effect of Artemisiae Argyi Folium Extract on Alcohol-Induced Gastritis (애엽(艾葉) 추출물이 알코올성 위염에 미치는 효과)

  • Lee, Jin A;Seo, Jeong Bok;Kim, Jin Young;Shin, Mi-Rae;Park, Hae-Jin;Roh, Seong-Soo
    • The Journal of Internal Korean Medicine
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    • v.43 no.4
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    • pp.738-750
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    • 2022
  • Objective: Alcohol is known to cause inflammation in the stomach by decreasing the protective substances of the gastric mucosa and increasing oxidative stress. The purpose of this study was to investigate the anti-inflammatory effect of Artemisiae Argyi Folium extract (AF) on alcohol-induced gastritis. Methods: The total polyphenol and flavonoid contents of AF were confirmed through an in vitro experiment. Radical scavenging activities were confirmed using DPPH and ABTS assays. In vivo experiments were conducted on mice divided into 5 groups (n=8): a normal group (Nor), an alcohol-induced gastritis group (Con), an alcohol-induced gastritis group administered 10 mg/kg sucralfate (SC), an alcohol-induced gastritis group administered 100 mg/kg AF (AFL), and an alcohol-induced gastritis group administered 200 mg/kg AF(AFH). The serum levels of reactive oxygen species (ROS) were determined, and protein expressions were confirmed in gastric tissues. Results: In alcohol-induced gastritis, AF alleviated damage to the gastric mucosa caused by alcohol. AF also decreased the serum ROS levels. Western blots showed that AF decreased the expression of NADPH oxidase and decreased the expression of the NF-κB pathway associated with inflammation. AF also decreased the expression of adhesion molecules and chemokine proteins, and increased the expression of anti-inflammatory proteins. Conclusions: AF not only reduced oxidative stress in alcohol-induced gastritis, but it also relieved gastric mucosal inflammation by regulating the expression of the NF-κB pathway.