• Mass Spectrometry Letters
• /
• v.10 no.3
• /
• pp.84-87
• /
• 2019

Liquid chromatography mass spectrometry is widely employed in proteomics studies. One of such instruments is the Liquid Chromatography (LC)-Matrix-assisted laser desorption ionisation (MALDI)-Time of flight (TOF) or LC-MALDI-TOF/TOF. In this study, this instrument was used to identify the membrane proteins of a protozoan parasite namely Entamoeba histolytica. It causes amoebiasis in human. The E. histolytica trophozoites were cultured prior to the membrane protein extraction using the conventional method, $ProteoPrep^{(R)}$ and $ProteoExtract^{(R)}$ kits. Then, the membrane protein extracts were trypticdigested and analysed by LC-MALDI-TOF/TOF. Approximately, 194 proteins were identified and 27.8% (54) were predicted as membrane proteins having 1 to 15 transmembrane regions and signal peptides by combining all three extraction methods. Also, this study has discovered 3 unique proteins as compared to our previous study which merit further investigation.

• Journal of Periodontal and Implant Science
• /
• v.46 no.5
• /
• pp.291-302
• /
• 2016

Purpose: The aim of the present study was to evaluate the effectiveness of using a mineralized bone cortical allograft (MBCA), with or without a resorbable collagenous membrane derived from bovine pericardium, on alveolar bone remodeling after immediate implant placement in a dog model. Methods: Six mongrel dogs were included. The test and control sites were randomly selected. Four biradicular premolars were extracted from the mandible. In control sites, implants without an allograft or membrane were placed immediately in the fresh extraction sockets. In the test sites, an MBCA was placed to fill the gap between the bone socket wall and implant, with or without a resorbable collagenous membrane. Specimens were collected after 1 and 3 months. The amount of residual particles and new bone quality were evaluated by histomorphometry. Results: Few residual graft particles were observed to be closely embedded in the new bone without any contact with the implant surface. The allograft combined with a resorbable collagen membrane limited the resorption of the buccal wall in height and width. The histological quality of the new bone was equivalent to that of the original bone. The MBCA improved the quality of new bone formation, with few residual particles observed at 3 months. Conclusions: The preliminary results of this animal study indicate a real benefit in obtaining new bone as well as in enhancing osseointegration due to the high resorbability of cortical allograft particles, in comparison to the results of xenografts or other biomaterials (mineralized or demineralized cancellous allografts) that have been presented in the literature. Furthermore, the use of an MBCA combined with a collagen membrane in extraction and immediate implant placement limited the extent of post-extraction resorption.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2004.05a
• /
• pp.179-182
• /
• 2004

This study reports the extraction behavior of $\alpha$-lactalbumin using bis(2-ethylhexyl) sulfosuccinate sodium (AOT) reverse micelles. Forward extraction of $\alpha$-lactalbumin in the reverse micellar organic phase from aqueous feed solutions was strongly dependent on the AOT concentration and the complete forward extraction of 0.03 mM $\alpha$-lactalbumin was successfully achieved at an AOT concentration of ca. 100 mM. A similar dependency of the forward extraction on the AOT concentration was obtained in isooctane, n-hexane, and n-octane systems. In the backward extraction from the micellar organic phase, the recovery of the protein as high as ca. 90% was obtained with pH control and/or salt addition.

• Journal of the Korean Society of Safety
• /
• v.8 no.2
• /
• pp.44-50
• /
• 1993

The objective of this study was to investigate the extraction of chromium(Vl) ion in waste water through the liquid surfactant membrane with open-type Perforated Reciprocating-Plate Column. Extraction experiments were conducted to measure the effect of flow characteristics of continuous and dispersed phase and stroke velocity, sodium hydroxide concentraction in internal aqueous phase, sulfuric acid concentraction in outer phase, and residence time distribution and measured extraction velocity. The result of experiments showed that extraction velocity of chromium ion was maximum when stroke velocity was 180 1/min and dispersion phase velocity was 30m11min, continuous phase velocity was 20m1/min. Extraction velocity of chromium ion increased with increasing difference of hydrogen ion concentraction of dispersion and continuous phase and column stage decreased.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2004.11a
• /
• pp.15-22
• /
• 2004

• The Journal of the Korean dental association
• /
• v.53 no.5
• /
• pp.348-359
• /
• 2015

Objective: The aim of this study was to determine the effect of multi-layer of a collagen membrane alone or loaded rhBMP-2 on the buccal plate for ridge preservation after tooth extraction. Material and methods: Following bilateral extraction of the maxillary 1st and 3rd premolars in five dogs, rhBMP-2 loaded collagen membrane was applied to the buccal plates at the 1st premolar and collagen membrane only was applied to the buccal plates at the 3rd premolar unilaterally. The collagen membranes applied in the experimental groups were piled into four layers. The corresponding sites of the contralateral side healed naturally. After 3months of healing, the animals were sacrificed. Radiographic and histologic analyses were performed. Results: There was no significant difference in the healing of extraction socket at both 1st and 3rd premolars. In microcomputed tomography, the widths of the residual ridge of the experimental groups were similar with the controls. Histologically, the experimental groups did not exhibit different pattern compared to the controls regardless of the addition of rhBMP-2. Conclusion: Layering of the collagen membrane with or without rhBMP-2 on the buccal plate failed to show the effectiveness in dimensional preservation of the extraction socket.

• Applied Chemistry for Engineering
• /
• v.8 no.4
• /
• pp.551-559
• /
• 1997

The stability of liquid membrane in the extraction process was investigated through the extraction of the Zn component by using W/O/W emulsion type liquid surfactant membrane which was $D_2EHPA-Kerosene-Span$ $80-H_2SO_4$ system. The highest stability for liquid membrane through the Zn extraction process was obtained under the following conditions. That conditions were that span 80 concentration, as surfactant, of 2~3 vol.%;$D_2EHPA$ concentration, as extractant, of 5~7 vol.%;paraffin oil concentration, as membrane strengthening agent, of 10 vol.%;emulsion volume ratio to the external aqueous phase volume of 0.1, and internal aqueous phase volume ratio to the organic phase volume of 1.0.

• Journal of Periodontal and Implant Science
• /
• v.39 no.1
• /
• pp.71-76
• /
• 2009

Purpose: Many researches showed loss of alveolar bone in fresh extraction socket and even in case of immediate implant placement. The aim of this study was to evaluate the effect of non-resorbable barrier membrane on the change of buccal and lingual alveolar bone in immediate implant placement into periapically infected extraction sockets. Materials and methods: Immediate implants were placed into artificially induced periapical lesion of mandibular premolars after complete debridement using buccal bone defect made by a 6mm trephine bur in 4 mongrel dogs. Before flap repositioning, a non-resorbable barrier membrane was placed on the buccal defect in the experimental group. No membrane was placed in the control group. In 12 weeks after placement, the dogs were sacrificed and undecalcified histologic specimens were prepared. The vertical distance from the smooth-rough surface interface(SRI) to gingiva, 1st bone contact and bone crest were measured in buccal and lingual side. The horizontal thicknesses of gingiva and bone at 0, 1, 2 and 3mm below SRI were measured. Results: The buccal bone was resorbed more than lingual bone in both groups and there was statistical significance(p<0.05). The distances from SRI to 1st bone contact were $2.45{\pm}2.35\;mm$ in experimental group and $4.49{\pm}3.10\;mm$ in control group. In all vertical level, lingual bone was thicker than buccal bone(p<0.05). Conclusion: Buccal bone was reduced more than lingual bone in immediate implant placement into periapically infected extraction sockets. Placement of non-resorbable barrier membrane reduced the buccal bone resorption. However there was no statistical significance.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.5 no.2
• /
• pp.174-185
• /
• 2004

Organic pollutants (Phenol, 2-Chlorophenol, Nitrobenzene) were separated from wastewater by nondispersive membrane solvent extraction, using a microporous hydrophobic hollow fiber module. The system was operated countercurrently and cocurrently with the aqueous phase flowing through the fiber lumens and the solvent flowing through the shell side. The distribution coefficients of several solvents (MIBK, IPAc, Hexane) were examined and MIBK was selected as an extracting solvent. Separation efficiency of countercurrent flow method was better than that of cocurrent flow method. Also, the overall mass transfer coefficients were determined.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.41
• /
• pp.16.1-16.6
• /
• 2019

Background: Silk mats have been approved for clinical trials by the Korean Food and Drug Administration as membranes for guided tissue regeneration (GTR). In this study, silk mat application was compared to high-density polytetrafluoroethylene (dPTFE) membrane application or no membrane group. Methods: To compare the silk mat group to the dPTFE group or the no membrane group, a retrospective sample collection was conducted. Bony defects were measured at the time of extraction (T0) and then at 3 months (T1) and 6 months after extraction (T2) on a digital panoramic view. Bone gain (BG) was calculated by subtracting from the bony defect at T0 to the bony defect at each follow-up. Results: The BG at T2 was 2.44 ± 2.49 mm, 4.18 ± 1.80 mm, and 4.24 ± 2.05 mm in the no membrane group, silk mat group, and dPTFE group, respectively. Both membrane groups had significantly higher BG than BG in the no membrane group at T2 (P < 0.05). Conclusions: Both membrane groups showed higher BG than the no membrane group.