• Title/Summary/Keyword: Membrane thickness

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Effects of bovine amniotic membrane graft on healing of full-thickness skin wound in dogs (소양막이식편이 개의 전층 피부 창상치유에 미치는 효과)

  • Hwang, Kyeong-teak;Kweon, Oh-kyeong;Woo, Heung-myung;Kim, Dae-young;Nam, Tchi-chou
    • Korean Journal of Veterinary Research
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    • v.39 no.3
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    • pp.645-652
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    • 1999
  • The purpose of the present study was to investigate the effect of bovine amniotic membrane grafts on healing of full-thickness skin wound in dogs. Two $3cm{\times}3cm$ area-matched full-thickness skin wounds were induced bilaterally on the dorsolateral aspect of the trunk of 15 dogs. Chlorhexidine-treated amnion, dried amnion, silver sulfadiazine and 0.9% sterile saline solution were applied on the wound area and examined grossly and histopathologically. Begining 14 days after wounding, amnion applied group had appreciably less amount of inflammatory exudate and hemorrhage than sulfadiazine and saline treated groups. From 14 days after wounding, the degree of wound contraction in amnion groups, especially in the dried amnion group was greater than that of the sulfadiazine and saline treated groups. The percentages of wounds completely healed on 28 days after wounding in saline treated group, chlorhexidine-treated amnion group, dried amnion group and sulfadiazine treated group were 33%, 50%, 83% and 50%, respectively. Microscopically neovascularization and fibrosis were first noticed on 5 days after wounding in the dried amnion group and sulfadiazine treated group, on 7 days in the chlorhexidine-treated amnion group and on 14 days in the saline treated group. Epithelialization in the dried amnion and sulfadiazine treated groups was first noticed on 9 days after wounding, which was faster than that in the other groups. The present study suggests that bovine amniotic membrane, especially dried bovine amnion is effective on healing of full-thickness skin wound in dogs through both wound contraction and epithelialization.

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Evaluation of Maxillary Sinus Using Cone-beam Computed Tomography in Patients Who Underwent Le Fort I Osteotomy (르포트씨 1급 골절단술을 시행 받은 환자들에서 Cone-beam Computed Tomography를 이용한 수술 전, 후의 상악동의 평가)

  • Lee, Jae-Yeol;Kim, Yong-Il;Baek, Young-Jae;Hwang, Dae-Seok
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.34 no.2
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    • pp.106-111
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    • 2012
  • Purpose: The aim of this sturdy was to assess the prevalence and change in pathologic findings in the maxillary sinus by using preoperative and postoperative cone-beam computed tomography (CBCT). Methods: The subjects included 83 patients with maxillary sinus abnormalities who underwent orthognathic surgery between January 2010 to December 2010. The CBCT analyses were classified according to the thickness of maxillary sinus membrane; Normal (membrane thickness<2 mm), mucosal thickening (membrane thickness ${\geq}2mm$ and <6 mm), partial opacification (membrane thickness>6 mm but not complete), total opacification, and polypoidal mucosal thickening. The diameters of the maxillary sinus ostium on the coronal cross-sectional view were also calculated. Results: Out of 166 maxillary sinuses in 83 patients, 42 (25.3%) maxillary sinuses before surgery and 37 (22.3%) maxillary sinuses after surgery showed abnormalities. A decrease in the diameters of maxillary ostium was observed after surgery (P<0.05). However, there was no significant difference in mucosal thickness both, preoperatively and postoperatively. Conclusion: The orthognathic surgery didn't deteriorate the maxillary sinus abnormaility. Despite the low prevalence of sinus complications in orthognathic surgery, all the patients should be informed of the possibility of sinusitis that could require the surgical intervention before surgery.

Feasibility study of membrane interface for gas chromatograph-mass spectrometry (기체크로마토그래프-질량분석기의 실리콘 분리막 인터페이스의 유용성 연구)

  • Kang, Gil Seon;Lee, Dong Soo;Lee, Hwa Sim;Park, Chang Joon
    • Analytical Science and Technology
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    • v.21 no.6
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    • pp.495-501
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    • 2008
  • Agilent 5973 GC-MS instrument was modified so that the capillary direct interface was removed and that a silicone membrane was installed between GC and MS. Feasibility study of the membrane interface GC-MS has been carried out. Vacuum of the mass spectrometer was not affected by the carrier gas flow rate up to $4.7m{\ell}/min$. As the carrier flow rate was increased, peak tailing was reduced and chromatogram peaks appeared earlier. Chromatogram peaks showed better separation and higher sensitivity as the membrane thickness was reduced from $127{\mu}m$ to $75{\mu}m$, and also as the interface temperature was increased. However, the membrane interface GC-MS had drawbacks such as background ions at 73 and 147 m/z and poor peak separation due to peak tailing.

Transport Coefficients across Charged Mosaic Membrane

  • Yang, Wong-Kang
    • Bulletin of the Korean Chemical Society
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    • v.25 no.5
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    • pp.665-667
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    • 2004
  • In previous studies, charged mosaic membranes having two different fixed charges in the membrane matrix indicated unique transport behavior such as preferential material transport. In this study, the composite charged mosaic membrane endurable to mechanical pressure in practical application was investigated from the same aspect of solute and solvent transport as before. Lp and ${\omega}$ estimated by taking account of active layer thickness were satisfactorily consistent with those in mosaic membrane without reinforcement. On the other hand, the reflection coefficient s indicated the negative value that suggests preferential material transport.

The Polymer Membrane Electrode by Surfactants for Measuring Continuously Thiocyanate Ion in Wastewater (폐수중 티오시안산이온을 측정하기 위한 계면활성제를 이용한 고분자 막전극)

  • 최종석;안형환;강안수;우인성;황명환
    • Journal of the Korean Society of Safety
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    • v.6 no.4
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    • pp.13-20
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    • 1991
  • Ion-selective electrode responsive to the thiocynate ion prepared by using the quaternary ammonium salts as a active material and PVC as a membrane matrix. The effect of chemical structure and composition of active material, and the membrane thickness on the linear response. the detection limit, and Nernstian slope of the electrode studied. Under the above optimum conditions of membrane, the effect of pH and the selectivity coefficients to various interfering anions were compared and investigated. It was concluded that the functions of thiocynate ion-selective electrode(ISE) were closely related to the chemical structure of the quaternary ammonium salts. The linear response, and the detection limit of the electrode potential increased with the increase of the carbon chain length of the alkyl group in the quaternary ammonium salts in the ascending order of Aliquat 336T, TOAT, TDAT, and TDDAT. The optimum membrane thickness was 0.3mm. The electrode characteristics was better with the decrease of the concentration of active material, and the best concentration was 3 weight percent. The membrane potential was independent of the pH variation in the region from pH 2 to 12. The order of the selectivity coefficients is as follows:Cl $O_4$$^{[-10]}$$I^{[-10]}$ >N $O_3$$^{[-10]}$ >B $r^{[-10]}$$F^{[-10]}$ >C $l^{[-10]}$ >O $A_{c}$ $^{[-10]}$ 〓S $O_4$$^{2-}$.

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Development of a Numerical Model for Cake Layer Formation Process on Membrane (멤브레인 케이크 레이어 형성 과정 모사를 위한 수치 모델의 개발)

  • Kim, Kyung-Ho;Shin, Jae-Ho;Lee, Sang-Hwan;Lee, Ju-Hee
    • The KSFM Journal of Fluid Machinery
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    • v.14 no.6
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    • pp.35-44
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    • 2011
  • Membrane filtration has become firmly established as a primary process for ensuring the purity, safety and efficiency of treatment of water or effluents. Several researches have been performed to develop and design membrane systems in order to increase the accuracy and performance of the processes. In this study, a lattice Boltzmann method for the cake layer has been developed using particle dynamics based on an immersed boundary method and the cake layer formation process on membrane has been numerically simulated. Case studies including various particle sizes were also performed for a microfiltration process. The growth rate of the cake layer thickness and the permeation flow rate along the membranes were predicted. The results of this study agreed well with that of previous experiments. Effects of various particle diameters on the membrane performance were studied. The cake layer of a large particle tended to be growing fast and the permeation flow going down rapidly at the beginning. The layer thickness of a small particle increased constantly and the flow rate was smaller than that of the large particle at the end of simulation time.

Fabrication of Perchlorate Ion Selective PVC Membrane Electrode (과염소산 이온선택성 PVC막전극 제작)

  • 우인성;안형환;강안수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.4
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    • pp.298-305
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    • 1998
  • The PVC membrane electrode for measuring perchlorate ion was developed by incorporating various quaternary ammonium sallts. The effect of chemical structure, the content of active material, the kind of plasticizers, and the membrane thickness on the electrode characteristic such as the linear response range and Nernstian slope of the electrode were studied. It was obtained that the effect of the chemical structure of an active material on the electrode characteristics was improved with increasing the alkyl chain length of the quarternary ammonium salts in the ascending order of Aliquat 336P, TOAP, TDAP, and TDDAP. The optimum membrane composition was 9.09wt% of TDDAP, 30.3wt% of PVC, and 60.6wt% of plasticizer(DBP). And the optimum membrane thickness was 0.45mm at this composition. Under the above condition, the linear response range was $10^{-1}~1.2\times10^{-6}$M, and the detection limit was $5.1\times10^{-7}$M with the Nernstian slope of 57mV/decade of activity of perchlorate ion. The electrode potential was stable within the pH range from 4 to 11. The selectivity coefficient was as shown below: $SCN^->I^-NO_3^->Br^->ClO_3^->F^->Cl^->SO_4^{2-}$

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Decreasing Effect of Lidocaine.HCl on the Thickness of the Neuronal and Model Membrane

  • Park, Sung-Min;Park, Jong-Sun;Kim, Jae-Han;Baek, Jin-Hyun;Yoon, Tae-Gyun;Lee, Do-Keun;Ryu, Won-Hyang;Chung, In-Kyo;Sohn, Uy Dong;Jang, Hye-Ock;Yun, Il
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.4
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    • pp.253-257
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    • 2013
  • This study examined the mechanism of action of a local anesthetic, lidocaine HCl. Energy transfer between the surface fluorescent probe, 1-anilinonaphthalene-8-sulfonic acid, and the hydrophobic fluorescent probe, 1,3-di(1-pyrenyl) propane, was used to determine the effect of lidocaine HCl on the thickness (D) of the synaptosomal plasma membrane vesicles (SPMV) isolated from the bovine cerebral cortex, and liposomes of the total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from the SPMV. The thickness (D) of the intact SPMV, SPMVTL and SPMVPL were $1.044{\pm}0.008$, $0.914{\pm}0.005$ and $0.890{\pm}0.003$ (arbitrary units, n=5) at $37^{\circ}C$ (pH 7.4), respectively. Lidocaine HCl decreased the thickness of the neuronal and model membrane lipid bilayers in a dose-dependent manner with a significant decrease in the thickness, even at 0.1 mM. The decreasing effect of lidocaine HCl on the membrane thickness might be responsible for some, but not all of its anesthetic action.

A study on the Thickness of Egg Shell Membrane and Egg Shell in Quail Eggs (메추리의 난각과 난각막의 두께에 관한 연구)

  • 하정기
    • Korean Journal of Poultry Science
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    • v.7 no.2
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    • pp.47-53
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    • 1980
  • This study was carried out to investigate the variations in the thickness of egg shell and egg shell membrane of Quail eggs from July 25, 1978 to September 7, 1978. No. of eggs used in this experiment was 520 okay and all the eggs were purchased from a farm located in Jinju city. The results obtained are summarized as follows: 1. Egg shells of quail were classified as white egg shell with large spots, egg shell with large spots, violet egg shell with small spots and beige egg shell with small spots by the exterior shell colour and their average egg weights were 8.993g, 8.866g, 8.403g and 8.109g, respectively. 2. Average egg shell thickness of white egg shell with large spots, egg. shell with large spots, violet egg shell with small spots and beige on shell with small spots were 0.171mm, 0.169mm, 0.160mm, and 0.156mm, respectively. 3. Average eggs shell membrane of white egg shell with large spots, egg shell with large spots, violet egg shell with small spots and beige egg shell with small spots were 0.0449mm, 0.0431mm, 0.0398mm, and 0.0397mm, respectively. 4. Negative correlation coefficient was found between egg shell thickness ana egg shell membrane thickness, but it was not significant. 5. Comparing quail egg with fowl egg, the thickness of quail egg shell was much thinner than that of fowl egg, but egg shell membrane thickness was similar between the two.

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