• Journal of Periodontal and Implant Science
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• v.35 no.1
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• pp.251-261
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• 2005

Alveolar ridge defects may limit or restrict placement of implants. The purpose of this study was to evaluate clinical and histopathologic results which occur following guided bone regeneration using platelet-rich plasma, bovine bone powder and e-PTFE membrane in the localized alveolar bone defects. Ten patients who required guided bone regeneration in implant placemnet, were slelected. Alveolar crest height and width were measured at baseline and, afer 2nd surgery 5 months later At 5 months , we obtained histopathological results as follows: 1. Alveolar crest height was an average of $8.20{\pm}3.74$ mm preoperatively and decreased to an average of $7.40{\pm}1.84$ mm postoperatively. There was no significant difference. 2. Alveolar crest width was an average of $4.25{\pm}2.03$ mm preoperatively and significantly increased to an average of $7.20{\pm}2.44$ mm postoperatively (P<0.01) 3. The change of Alveolar crest height and width were $0.80{\pm}1.40$ mm, $2.95{\pm}1.09$ mm 4. Histopathological evaluations revealed new bone formation with graft material and laminated bone containing the presence of osteocyte-like cell In conclusion, guided bone regeneration using platelet-rich plasma, bovine bone powder and e-PTFE membrane would provide a viable therapeutic alternative for implant placement in the localized alveolar defect or implant failure

• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.59-66
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• 2008

Purpose: It has been shown that the inorganic polyphosphate is effective for the regeneration of bones through the preliminary animal test of rabbits. The most effective concentration of the polyphosphate, however, is not known yet. Moreover, the effectiveness of carriers inside human body is not confirmed.. Materials and Methods: In this study, we examined the effect of the concentration of the inorganic polyphosphate on the process of the bone regeneration using the 6 weeks old rabbits with the weight of 2.0 kg in average. We performed the experiment using TR-ePTFE membrane(membrane) filled with collagen immersed in 4%, 8% of inorganic polyphosphate, respectively, following removal of the proper sized cortical bones from the rabbit calvaria. The experimental results were compared with the one of the following four groups: The negative control group for membrane only, the positive control group for membrane filled with collagen, the first experimental group for membrane filled with collagen immersed in 4% of inorganic polyphosphate, and the second experimental group for membrane filled with collagen immerse in 8% of inorganic polyphosphate. The fragments of the tissue with membrane obtained from each group of the sacrificed rabbits for 8 or 16 weeks sustained after surgery were then prestained by the Hematoxylin-Eosin stain and coated by resin to form non-decalcified specimens for the histologic examination and analysis. New bone formation was assessed by histomorphometric and statistical analysis. Results: 1. All groups have shown better bone regeneration at 16weeks than 8weeks. 2. Negative control group has shown more bone regeneration relative to the other groups at 8 and 16 weeks. 3. All experimental groups have shown better bone regeneration relative to positive control group. 4. At 16 weeks, the first experimental group has shown more bone regeneration compared to the second experimental group. Exophytic bone formation is not good at the first and the second experimental groups compared with negative control group. But, the use of 4% inorganic polyphosphate was more effective to bone formation than the use of 8% inorganic polyphosphate. Conclusion: With above results, it is suggested the use of inorganic polyphosphate with vehicle under TR-ePTFE membrane.

• Membrane and Water Treatment
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• v.4 no.4
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• pp.277-291
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• 2013

The transport and recovery of Levafix brilliant red E-4BA and Levafix brilliant red E-6BA were investigated using polytetrafluoroethylene (PTFE) fiber based supported liquid membrane containing tetra butyl ammonium bromide (TBAB) in coconut oil as a carrier. The influencing parameters studied are: pH of the feed solution, concentration of dye in the feed solution, extractant concentration, and various kind of stripping agent, rate of stirring, time of transport, reusability of membrane and stability of membrane. Increase in TBAB concentration inside the membrane enhances the flux with its maximum value at $1.553{\times}10^{-4}$ M TBAB. Further increase in the concentration of TBAB leads to decreased rate of transport due to increase in viscosity of membrane liquid. The optimum conditions for dye transport are: pH of feed ($7{\pm}0.1$), $1.553{\times}10^{-4}$ M extractant concentration, 350 rpm for stirring, $4.9{\times}10^{-1}$ M potassium hydrogen phthalate as a stripping solution, the time of transport 6 h. It was noticed that flux values were increased with increasing dye concentration in the feed phase. Applying this study to textile wastewater, dyes were transported up to 98% in 6 h. This recovery technique is rewarding to environment and economic.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.80-88
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• 1996

The aim of the present investigation was to see the effect of combined use of PDGF BB and IGF -1 on the guided tissue regeneration(GTR) using barrier membrane in the treatment of human furcation involvement. Twelve patients with initially diagnosed as having moderate to advanced adult periodontitis with mandibular class II buccal furcation defects have been wer selected. Initial scaling and root planing has been performed and baseline data consisting of probing depths and attachment levels have been recorded prior to surgical procedures. The GTR procedures using either barrier membrane(control : ePTFE) alone or together with the application of PDGF - BB and IGF -l(experimental : ePTFE+PDGF/IGF) have been done under the routine guidelines. During the surgery, the distance from CEJ either to the bottom of the bone defects(CEJ - BD) or to the bone crest(CEJ-BC) were measured. Horizontal distance to the deepest area in the furcal defects were measured from the reference line connection the most prominent bony walls of the two buccal roots. 6 months following the GTR therapy, all the measurements were made repeatedly. The probing attachment gain of the experimental and the control grous were 2.14mm and l.07mm, respectively with no statically significnant difference. Amont of vertical bone fill in the experimental and the control groups were 2.43mm and 2.29mm, rexpectively. Amonut of horizontal bone fill were 2.86mm in the experimental group and 2.17mm in the control group, respectively. However, there were no significant differences in the amount of bone fill(both vertical and horizontal)between the two groups.

• 대한치주과학회:학술대회논문집
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• 1994.12a
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• pp.47-47
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• 1994

• Membrane and Water Treatment
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• v.5 no.1
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• pp.41-56
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• 2014

A series of microporous PVDF membranes were prepared by isothermal immersionprecipitation of PVDF/TEP casting dopes in both soft and harsh coagulation baths. Morphologies of the membranes' top surfaces were found to depend strongly on the bath strength, which could be controlled by the TEP content in the bath. By changing the bath gradually from pure water to 70% TEP, the top surface evolved from a dense skin-like (asymmetric) to a totally open porous morphology (symmetric). The latter structure could similarly be obtained by precipitation of the same dope in an alcoholic bath, e.g., 1-butanol. Membrane distillation processes to desalt sodium chloride aqueous solutions were conducted using various prepared membranes and two commercial microporous membranes, PTFE (Toyo, Japan, code: J020A330R) and PVDF (GE, USA, code: YMJWSP3001). The permeation fluxes were compared and correlated with the morphologies of the tested membranes.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.17-21
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• 2019

The redox flow battery (RFB) is a large-capacity energy storage equipment, and the vanadium redox flow cell is a typical RFB, but VRFB is expensive. Iron-chrome RFBs are economical because they use low-cost active materials, but their low performance is an urgent problem. One of the reasons for the low performance is the crossover of the active materials. In this study, the sulfonated Poly (ether ether ketone) (sPEEK) membrane, which is a hydrocarbon membrane, was used instead of the fluorine membrane to reduce the crossover of the active materials. The chromium ion permeability of the sPEEK membrane was $1.8{\times}10^{-6}cm^2/min$, which was about 1/33 of that of the Nafion membrane. Thus, it was shown that the use of the sPEEK membrane instead of the fluorine membrane could solve the high active material crossover problem. The activation energy of iron diffusion through the sPEEK membrane was 24.9 kJ/mol, which was about 66% of Nafion membrane. And that the e-PTFE support in the polymer membrane reduces the active material crossover through Iron-Chrome Redox Flow Battery (ICRFB).

• Journal of Chest Surgery
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• v.22 no.5
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• pp.724-730
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• 1989

The development of severe pericardial adhesion after cardiovascular surgical procedures often increases the risk of injuring the heart, great vessels, or extracardiac grafts during resternotomy. Several pericardial substitutes have been tested in an attempt to facilitate reoperation with inconclusive results. This study was designed to evaluate the applicability of two different materials as pericardial substitutes to minimize the pericardial adhesion and epicardial reaction. A procedure for induction of pericardial adhesion was carried out in 30 rabbits. Rabbits were divided into three groups of ten rabbits each: Group 1[control, simple pericardial closure]: Group 2[bovine pericardium as pericardial substitute]: Group 3[e-polytetrafluoroethylene surgical membrane, e-PTFE as a pericardial substitute]. Bovine pericardium or e-PTFE surgical membrane was interposed between the sternum and the heart. Rabbits were sacrificed at 4 weeks after operation. The development of adhesions and epicardial reactions were graded as: none [I]; minimal[II]; moderate[Ill]; and severe[1V]. Histologic studies of the substitute, the pericardium, and the epicardium were performed. The results were as follows; l. In group 1[control group], the degree of pericardial adhesions were grade I in none, grade II in 1, grade III in 3, and grade 1V in 6 animals. Epicardial reactions were grade I in none, grade II in 3, grade K in 4, grade 1V in 3 animals respectively. 2. In group 2[bovine pericardium], the degree of pericardial adhesions were grade I in 1, grade II in 5, grade III in 3, and grade 1V in 1 animal. Epicardial reactions were grade I in 1, grade II in 2, grade III in 4, and grade 1V in 3 animals respectively. 3. In group 3[e-PTFE], the degree of pericardial adhesions were grade I in 7 animals, grade II in 2, grade III in 1, and grade g in none. Epicardial reactions were grade I in 4, grade II in 3, grade III in 2, and grade IV in 1 animal respectively. Pericardial adhesions more than grade II were 90.9% in group 1, 40 % in group 2, and 10% in group 3. Pericardial adhesions were significantly reduced in group 3 compared to group 1 or 2. Epicardial reactions more than grade II were 70 % in group 1, 70 % in group 2 and 30 % in group 3. We concluded that this 0.1mm thick polytetrafluoroethylene surgical membrane is a suitable pericardial substitute to minimize the development of pericardial adhesion or epicardial reaction following cardiovascular surgery.

• 대한치주과학회:학술대회논문집
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• 2005.11a
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• pp.201-202
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• 2005

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.2
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• pp.112-126
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• 1998

In dentistry, bony defects can be formed by cyst, tumor, inflammation, trauma and surgery in maxilla and mandible. If the overlying soft tissue invades and preoccupies the jaw bony defects, regenerated bony tissue same as adjacent bone can not replace whole space of the defects, thus preventing osteogenesis from occurring. Guided bone regeneration(GBR) is based on the prevention of overlying soft tissue from entering the bony defect during the initial healing periods. E-polytetrafluoroethylene(e-PTFE) is one of an effective and widely used barrier membrane for GBR, but it has the disadvantages such as surgical removal and high price. To overcome such disadvantages of e-PTFE, many investigators have proposed various absorbable barrier membranes. Inexpensive oxidized cellulose($Surgicel^{(R)}$) membrane was shown to have potential for use as an absorbable barrier membrane for regenerative procedure and it would not require surgical removal. The purpose of this study is to investigate the absorption periods of oxidized cellulose at the implant site and usefulness as a mechanical barrier, preventing the ingrowth of the overlying soft tissue into the bony defects. Two bony defects were made in each tibia of a dog using drill and one defect covered with oxidized cellulose and the other covered with periosteum directly as control. The experimental animals were sacrificed at 1st-7th, 10th, 14th, 21th, 28th day postoperatively, Inspection of the specimens was done to evaluate gross changes. Specimens were examined histopathologically by hematoxylin-eosin and Masson's trichrome staining under light microscope. The results were as follows : 1. There was no significant differences of inflammatory reaction between the experimental and the control group. 2. The resorption of oxidized cellulose was almost completed within 14th day. 3. Histologically, bone formation in the experimental group was somewhat more than that of the control group at 10th, 14th, 21th and 28th day postoperatively. The bone forming pattern of the experimental group was more regular than that of the control group. 4. There was no evidence of soft tissue invasion into the bony defect in the experimental group. In conclusion, oxidized cellulose membrane might be used as an alternative absorbable barrier membrane to prevent overlying soft tissue invasion into the bony defects.