1.Effect of intermediate resin hydrophilicity on bond strength of single step adhesive.
Yong Sung KIM ; Sang Hyuk PARK ; Gi Woon CHOI ; Kyoung Kyu CHOI
Journal of Korean Academy of Conservative Dentistry 2007;32(5):445-458
The purpose of this study was to evaluate the bond strength of a new Single step system with different curing mode composites, and to evaluate the effect of the intermediate resins which have different hydrophilicity on bonding ability by means of the micro shear bond testing and TEM examination for the adhesive interface. The adhesive used in this study was an experimental single step system (Bisco Inc., Schaumburg, IL). Experimental groups were produced by using six kinds of intermediate resin having different hydrophilicity that was hydrophilic, hydrophobic and most hydrophobic resin and as filled or not after applying adhesive. Each experimental group was further divided into two subgroups whether the adhesive was light cured or not. Dual cured composite (Bis Core, Bisco Ltd., Schaumburg, IL) was placed on the adhesive layer as light cure or self cure mode. The results of bond strength were statistically analyzed using one way ANOVA and multiple comparisons are made using Tukey's test at alpha < 0.05 level. The results of this study were as follows; 1. The application of intermediate resin did not increase the bond strength for light cured composite. 2. The bond strength of an experimental adhesive with self cured composite was significantly increased by the application of intermediate resin layer. 3. The bond strength of adhesive was irrespective of the cure or not of itself before intermediate resin layer applied. 4. As applied hydrophilic resin layer was, the initial bond strength was higher than both hydrophobic and most hydrophobic one used but there was no significance. Using a single step adhesive with dual/self cured composite, the incompatibility between both of them should be solved by the application of intermediate hydrophobic resin to reduce the adhesive permeability. However, Single step adhesive can be used in the light cured composite restoration without any decrease of the initial bond strength.
Adhesives*
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Hydrophobic and Hydrophilic Interactions*
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Permeability
2.Research development of surface hydrophilicity and lubrication modification of interventional guide wire.
Bing ZHAO ; Xiaohong LIU ; Ting YUAN
Chinese Journal of Medical Instrumentation 2015;39(1):44-47
Surface lubricity is one of the important performance criteria for interventional guide wire. In this paper, a review of the methods of surface hydrophilicity and lubrication modification of interventional guide wire is presented, including their fundamental principles, effects and some relative applications. These methods all have their own advantages and disadvantages, therefore, limitations of experimental conditions need to be taken into account.
Catheterization
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Hydrophobic and Hydrophilic Interactions
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Lubrication
3.The Effect of Rabbit Serum on the Expression of Cell Surface Hydrophobicity in Candida albicans.
Woon Seob SHIN ; Donghwa KIM ; Kyoung Ho LEE ; Kyunghoon KIM ; Yoon Sun PARK ; Choon Myung KOH
Korean Journal of Medical Mycology 2000;5(4):167-172
No abstract available.
Candida albicans*
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Candida*
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Hydrophobic and Hydrophilic Interactions*
4.Advances in Polymer Hydrophilic Lubricating Coatings for Medical Catheters.
Ye LI ; He YANG ; Jingyi FANG ; Xintian LI ; Lei WANG ; Hong CHEN
Chinese Journal of Medical Instrumentation 2021;45(1):57-61
Polymer hydrophilic lubricating coatings for medical catheters refer to highly hydrophilic coating films fixed on the surface of catheters with binding force, which can reduce the surface friction with human tissues during the use of interventional catheters, improve the patient comfort of and effectively reduce the incidence of infection. Based on the development process of medical catheter coating, this review summarizes recent advances in the field of polymer hydrophilic lubricating coatings for medical catheters from types of hydrophilic coating polymer, development of coating technology and establishment of coating performance evaluation method. Main problems in this field are analyzed and development trends in the future are prospected.
Catheters
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Humans
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Hydrophobic and Hydrophilic Interactions
;
Polymers
5.Fabrication of rough surface on titanium using electrochemical treatment in NaCl electrolyte
Bichna KIM ; Woon Young LEE ; Yeong Joon PARK ; Ho Jun SONG
Korean Journal of Dental Materials 2019;46(2):121-130
It is difficult to get sufficient roughness on titanium implant surface using traditional electrochemical treatments. In this study, we have developed a new method which provides a hybrid structured titanium surface having micro/nano roughness using electrochemical treatment in NaCl electrolyte and hydrothermal treatment. Titanium disks were anodically oxidized (ANO) in 0.15M NaCl electrolyte by applying positive electric pulses. The oxide compounds loosely attached to the surface were removed by ultrasonic cleaning (ANO group). These specimens were hydrothermally (HT) treated in an alkaline solution (ANO-HT group). ANO group showed the dimpled grain surfaces with a diameter of approximately 30 µm, and its roughness (Ra) was about 2.4 µm. The nano-sized crystallites which had an anatase TiO₂ crystalline structure were uniformly distributed on the surface of ANO-HT group. This group still retained high roughness (~2.7 µm) similar to ANO group and showed high hydrophilicity. Titanium surface with high roughness and hydrophilicity was fabricated using new electrochemical treating method and hydrothermal treatment. This surface modification method could be used for enhancing the osteoconductivity of the titanium implants.
Crystallins
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Hydrophobic and Hydrophilic Interactions
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Methods
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Titanium
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Ultrasonics
6.The Effect of the Hydrophobicity by Fluorocarbon Plasma Coating on the Degradation of Polylactic Acid.
Jin Hyung SUNG ; Sung Soo KIM ; Young Mi YOO ; Eun Deock SEO ; Jin Young KIM ; Jeong Soo PARK
The Journal of the Korean Orthopaedic Association 1998;33(2):423-432
The use of resorbable implants has always been attractive to surgeons because there is no need to remove implant ai'ter fracture fixation. Other advantages include decreased load sharing, multi-taskirv ancl no metal toxicity. But the strength and stiffness of resorhable implants are less than those of metallic implants. Therefore, these implants are suitahle for fixation of particular fractwre sites such as cancellous bone and epiphyscs in which shear loads comprise the major strains. The purpose of this experimental study was to determine whether there are changes in mechanical properties and tissue reactions in the polylactic acid (PLA) rod hy surface moditication using plasma coating or hexafluoropropylene (CF3CF=CF2). PLA rods were inserted into the subcutaneous tissue of back and distal femur in rabbits. Rods in subcutaneous tissue were retrieved for material characterization and those in distal femur were ohtained for histologic observation at postoperative 2, 5, 12 and 16 weeks. The results were as follows; 1. The hydrophobicity of PLA surface was successfully ohtained by plasma coating of hexatluoropropylene gas. 2. Thcre is no significant change in tissue reaction. between controi and plasma coating PLA group. 3. The diametral strength and 3-points bending strength of plasma coating groups were higher than those of control group until postoperative 12 wks, but, diminished at postoperative 16 weeks. In conclusion, the plasma coating of PLA rod using fluorocarbon is a reasonable technique to incrcase the surface hydrophohicily and a promising method to delay the reduction of the strength of PLA rod. Further study on thicker plasma coating and Jong term effect including degradation, nsetaholism and excretion of cotated fluorocarhon will be needed.
Femur
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Fracture Fixation
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Hydrophobic and Hydrophilic Interactions*
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Plasma*
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Rabbits
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Subcutaneous Tissue
7.Effect of pretreatment by solid-state fermentation of sawdust on the pelletization and pellet's properties.
Jingjing GUO ; Xingzhong YUAN ; Hui LI ; Changzhu LI ; Zhihong XIAO ; Zhihua XIAO ; Longbo JIANG ; Guangming ZENG
Chinese Journal of Biotechnology 2015;31(10):1449-1458
We pretreated sawdust (Castanopsis fissa Rehd.et Wils) by solid state fermentation (SSF) with Phanerochaete chrysosporium, and then compressed it into pellets with the moisture content of 15% and the pressure of 98 MPa, to solve the problem of low density, low Meyer hardness, high water uptake, and short storage period of pellet in the woody pellet industry. We studied the effects of fermentation time on pelletization and pellets's characteristics (including energy consumption, density, Meyer hardness, and hydrophobicity). SSF affected the heating values of pellet. Compared with fresh sawdust, SSF consumed more energy at the maximal value by 6.98% but saved extrusion energy by 32.19% at the maximum. Meanwhile, SSF could improve the density, Meyer hardness and hydrophobicity of pellet. Pellet made of sawdust pretreated by SSF for 48 d had best quality, beneficial for long-term transportation and storage of pellets.
Biofuels
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Fermentation
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Hydrophobic and Hydrophilic Interactions
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Phanerochaete
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Water
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Wood
8.Construction and application of pharmacophore model of human carboxylesterase 2 inhibitors.
Jing-Fang ZHANG ; Yan-Cheng LI ; Gui-Yang XIA ; Yun-Qing SONG ; Ling-Yan WANG ; Peng-Cheng LIN ; Guang-Bo GE ; Sheng LIN
China Journal of Chinese Materia Medica 2021;46(3):638-644
According to human carboxylesterase 2(hCE2) inhibitors reported in the literature, the pharmacophore model of hCE2 inhibitors was developed using HipHop module in Discovery Studio 2016. The optimized pharmacophore model, which was validated by test set, contained two hydrophobic, one hydrogen bond acceptor, and one aromatic ring features. Using the pharmacophore model established, 5 potential hCE2 inhibitors(CS-1,CS-2,CS-3,CS-6 and CS-8) were screened from 20 compounds isolated from the roots of Paeonia lactiflora, which were further confirmed in vitro, with the IC_(50) values of 5.04, 5.21, 5.95, 6.64 and 7.94 μmol·L~(-1), respectively. The results demonstrated that the pharmacophore model exerted excellent forecasting ability with high precision, which could be applied to screen novel hCE2 inhibitors from Chinese medicinal materials.
Carboxylesterase/metabolism*
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Humans
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Hydrogen Bonding
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Hydrophobic and Hydrophilic Interactions
9.Relationship between Biofilm Formation Ability and Virulence of Candida albicans.
Su Jung PARK ; Sun Ju CHOI ; Woon Seob SHIN ; Hyuk Min LEE ; Kkot Sil LEE ; Kyoung Ho LEE
Journal of Bacteriology and Virology 2009;39(2):119-124
Biofilms are microbial communities that form on a surface and are surrounded by extracellular polymeric substances. Candida biofilms are a cause of infections associated with medical devices. In the present study, an attempt was made to evaluate a significance of biofilm formation ability (BF) in virulence of C. albicans. C. albicans of 98 isolates, 24 commensal strains obtained from the oral cavities of healthy volunteers, 29 from blood culture, 25 from urine culture, and 20 from vaginal candidiasis, were assayed for BF, an ability to adhere to epithelial cells (ADH), cell surface hydrophobicity (CSH), and germ tube forming rate (GT). The relationships of BF with CSH, ADH, and GT were statistically examined. A positive correlation between BF and ADH was obtained, but the correlation (r=0.326) was relatively low. To assess BF as a factor contributing for candidiasis, mice lethality test was performed. The 10 isolates with the highest BF (mean survival rate, 24%) allow to kill mice more than those with the 10 lowest BF (mean survival rate, 47%). In addition, clinical strains isolated from blood culture, urine culture, and vaginal candidiasis showed higher BF than oral commensal strains. These results suggest BF may represent a virulent characteristic of C. albicans.
Animals
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Biofilms
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Candida
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Candida albicans
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Candidiasis
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Epithelial Cells
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Hydrophobic and Hydrophilic Interactions
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Mice
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Polymers
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Survival Rate
10.Wettability of denture relining materials under water storage over time.
Na Young JIN ; Ho Rim LEE ; Heesu LEE ; Ahran PAE
The Journal of Advanced Prosthodontics 2009;1(1):1-5
STATEMENT OF PROBLEM: Poor wettability of denture relining materials may lead to retention problems and patient discomfort. PURPOSE: Purpose of this study is to compare and evaluate wettability of nine denture relining materials using contact angle measurements under air and water storage over time. MATERIAL AND METHODS: Nine denture relining materials were investigated in this study. Two heat-curing polymethyl-methacrylate (PMMA) denture base materials: Vertex RS, Lang, one self-curing polyethyl-methacrylate (PEMA) chairside reline resin: Rebase II, six silicone relining materials: Mucopren soft, Mucosoft, Mollosil(R) plus, Sofreliner Touch, GC Reline(TM) Ultrasoft, Silagum automix comfort were used in this experiment. Contact angles were measured using high-resolution drop shape analysis system (DSA 10-MK2, KRUESS, Germany) under three conditions (in air after setting, 1 hour water storage, and 24 hours water storage). Nine materials were classified into three groups according to material composition (Group 1: PMMA, Group 2: PEMA, Group 3: Silicone). Mean values of contact angles were compared using independent samples t-test and one-way ANOVA, followed by a Scheffe's post hoc analysis (alpha= 0.01). RESULTS: Contact angles of materials tested after air and water storage increased in the following order: Group 1 (PMMA), Group 2 (PEMA), Group 3 (Silicone). Heat-cured acrylic denture base resins had more wettability than silicone relining materials. Lang had the highest wettability after 24 hours of water storage. Silicone relining materials had lower wettability due to their hydrophobicity. Wettability of all denture relining materials, except Rebase II and Mollosil(R) plus, increased after 24 hours of water storage. CONCLUSIONS: Conventional heat-cured resin showed the highest wettability, therefore, it can be suggested that heat-cured acrylic resin is material of choice for denture relining materials.
Denture Bases
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Denture Rebasing
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Dentures
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Humans
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Hydrophobic and Hydrophilic Interactions
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Polymethyl Methacrylate
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Retention (Psychology)
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Silicones
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Water
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Wettability