• Journal of Periodontal and Implant Science
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• 제37권4호
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• pp.791-803
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• 2007

The purpose of this study was to evaluate exophytically vertical bone formation in residual ridge of the beagle dog by the concept of guided bone regeneration with a titanium reinforced e-PTFE membrane combined with irradiated cancellous human bone. Twelve male beagle dogs(mean age 1.5 years and mean weight 12kg) were used for this study. The alveolar ridges after extraction of all mandibular premolars were surgically and horizontally removed. At 8 weeks after extractions, full-thickness flap was reflected and cortical bone was removed with round bur and copious irrigation. Rectangular parallelepiped(10mm in length, 5mm in width, and 4mm in height) bended with titanium-reinforced e-PTFE(TR e-PTFE) membrane was placed on the decorticated alveolar ridge, fixed with metal pins and covered with full-thickness flap and assigned as a control group. Test groups ere treated with TR e-PTFE membrane filled with irradiated cancellous human bone. Of twelve beagle dogs, four control dogs and four test dogs without membrane exposure to oral cavity were sacrificed at 8 and 16 weeks respectively. The surgical sites were dissected out, fixed in 4% buffered formaldehyde, dyed using a Villanueva staining technique, and processed for embedding in plastic resin. The cutting and grinding methods were routinely processed for histologic and histomophometric analyis of exophytic bone formation as well as statistical analysis. The results of this study were as follows: 1. Exophytic bone formation in the both of experimental groups was increased respectively after surgery from 23.40% at 8 weeks to 46.26% at 16 weeks in the control groups, from 40.23% at 8 weeks to 47.11% at 16 weeks in the test groups(p<0.05). 2. At 8 weeks after surgery, exophytic bone formation was made 40.23% in the test groups and 33.40% in the control groups. Exophytic bone formation was significantly made in the test group more than in the control group. At 16 weeks after surgery, exophytic bone formation was made 44.11% in the test groups and 46.26% in the control groups. Exophytic bone formation was made in the test groups more than in the control groups, but there was no statistically significant differences. 3. The membrane was fixed with metal pins to closely contact it to the bone surface. So, collapse and deviation of the membrane could be prevented and in growth of connective tissue also could be blocked from the periphery of the membrane. On the basis of these findings, wee suggest that intraoral experimental model for exophytic bone formation may be effective to evaluate the effect of bone graft material. And it indicates that combined use of membrane and ICB graft material is more effective than use of membrane only for exophytic bone formation.

• 한국식품과학회지
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• 제37권6호
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• pp.1018-1023
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• 2005

굴로부터 오염된 바이러스를 농축하고 검출하는 방법이 개발되었다. 바이러스를 인위적으로 굴 추출물에 접종시킨 후 polyethylene glycol(PEG)로 침전시키고 chloroform 또는 Freon으로 추출한 후 다시 PEG로 침전시켜 바이러스를 농축하였다. 각 단계별로 회수되는 폴리오바이러스의 량을 plaque assay를 이용하여 측정한 결과 처음 접종한 바이러스의 16.4-26.0%가 회수됨을 알 수 있었다. 검출을 위해서는 농축된 바이러스를 TRlzol로 추출한 후 바이러스의 RNA를 희석하거나 silica gel membrane을 이용하여 capture한 후 RT-PCR로 확인할 수 있었다. 그러나 상추와 햄버거에서 RT-PCR 방해물질을 효과적으로 제거하는 $QIAshredder^{TM}$ Homogenizer는 굴에 존재하는 방해물질을 제거하지 못하였다. 식품에 오염된 바이러스 농축을 위해 Freon이 일반적으로 사용되나 chloroform으로 대체가 가능하였다. 검출한계에 있어 굴 전체의 추출물을 사용하는 것과 소화기만을 분리하여 사용하는 경우 차이가 없으므로 RT-PCR 방해물질이 굴 전체조직에 고루 분산되어 있다고 판단된다. nested PCR은 이 방법의 효율을 높여주었다. 전체적으로 이 방법을 사용하면 굴로부터 오염된 노로바이러스의 검출이 가능하다고 판단된다.

• 한국식품과학회지
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• 제35권4호
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• pp.591-597
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• 2003

국내에서 시판되는 감자와 수입 감자스낵류로부터 상용 DNA 추출 kit 및 CTAB-phenol/chloroform 추출법등을 이용하여 시료특성에 따른 genomic DNA를 추출방법을 선정하고 PCR 정성검사를 실시하였다. 생감자의 경우 STE 용액으로 과량의 전분을 제거한 다음 DNA를 추출한 경우 순도 높은 DNA를 추출할 수 있었으며 상용 추출 kit를 이용한 경우 lysis buffer와 함께 ${\alpha}-/{\beta}$-amylase를 각각 또는 혼합으로 처리하거나 추출된 DNA 용액에 마지막 단계에서 효소를 처리한 시료군에서 고순도의 DNA를 추출할 수 있었으며, 효소 처리군에서는 ${\alpha}-/{\beta}$-amylase를 혼합으로 처리한 경우에 DNA 추출수율이 높았다. 냉동가공감자의 경우 silica-coated bead법을 이용하여 효소를 처리한 경우와 CTAB-페놀 클로로포름 처리군에서 DNA가 추출되었다. 또한, 각 방법으로 추출한 DNA에 대하여 감자의 내인성 유전자인 Pss 프라이머를 사용하여 PCR을 한 결과 모든 시료에서 추출된 DNA에 대하여 내부표준유전자 증폭산물이 검출되었다. 고도의 가공처리를 거친 수입 감자스낵(fabricated potato chips)과 냉동가공 감자(frozen fried potato) 등은 계면활성제인 CTAB(cetyl trimethyl ammonium bromide)과 페놀-클로로포름 혼합액을 이용하여 추출하고 이를 template로 하여 PCR 증폭을 실시하였다. 그 결과, Fig. 8에 제시한 바대로 감자의 내인성 유전자인 Pss 특이적 산물인 216bp의 산물이 냉동감자가공품과 감자칩에서 검출되었으며 재조합유전자인 New leaf plus 유래의 증폭산물(234bp)와 New lear Y유래의 증폭산물(225bp)는 검출되지 않았다. 본 실험의 결과 시료의 가공특성과 적용한 추출 kit 및 방법에 따라 genomic DNA 순도 및 추출수율이 크게 차이가 났으며 이것이 결국 PCR 결과에 의음성 혹은 의양성 등에 영향을 미치게 될 것으로 판단된다. 또한, 동일한 DNA추출방법에 의해서도 DNA가 추출되지 않은 경우가 있어서 동일한 시료에서 2회 반복 추출하는 것이 의음성결과를 피할 수 있는 방법으로 판단된다.

• 분석과학
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• 제18권2호
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• pp.154-162
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• 2005

최근 국내 일부 정수장에서 검출된 것으로 보도되어진 바 있어 우리나라의 하천 수의 오염이 우려되고 있고, 일부 오염정도가 높은 하천수의 정화과정에서 제거가 완전히 이루어지지 않는 것으로 사료되는 1,4-dioxane은 그 독성과 음용수의 섭취량을 고려할 때 음용수 섭취로 인한 인체효과가 문제화 될 것으로 판단된다. 따라서 본 연구에서는 활성탄과 멤브레인으로 구성된 다단계 필터시스템에서 음용수 중에 존재하는 1,4-dioxane에 대한 제거효과에 대하여 연구하였다. 확인방법은 MTBE을 이용한 액체-액체 추출방법을 사용하였으며 제거실험은 압력별 필터단계별로 30 L마다 300 L 까지 실시하였다. 그 결과 초기에는 1차 활성탄 필터이후 70% 이상의 제거효과를 나타내었으며 멤브레인 이후 95%이상 그리고 2차 활성탄 이후 100% 제거되는 결과를 나타내었다. 그러나 통수량이 증가할수록 각 단계별 제거율은 점차 감소하였으며 300 L 통수 후 1차 활성탄에서 30%, 멤브레인 이후 88% 그리고 최종 활성탄 이후 99%의 제거율을 나타내었다.

• Membrane and Water Treatment
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• 제9권5호
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• pp.327-334
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• 2018

The nano/micro composites with highly porous surface area have attracted of great interest, particularly the synthesis of porous and thin film sheets of high performance. In this paper, an easy method of cost-effective synthesis of thin film ceramic fiber membranes based on Hydroxyapatite, and activated carbon by turned into studied to be applied within the service-facilitated the transport of radioactive waste such as $^{90}Sr$, $^{137}Cs$ and $^{60}Co$) as activated product of radioisotopes from ETRR-2 research reactor and dissolved in 3M $HNO_3$, across a thin flat-sheet supported liquid membrane (TFSSLM). Radionuclides are transported from alkaline pH values. The presence of sodium salts in the aqueous media improves in $HNO_3$, the lowering of permeability because the initial $HNO_3$ concentration is improved. The study some parameters on the thin sheet ceramic supported liquid membrane. EDTA as stripping phase concentration, time of extraction and temperature were studied. The study of maximum permeability of radioisotopes for all parameters. The pertraction of a radioactive waste solution from nitrate medium were examined at the optimized conditions. Under the optimum experimental 98.6-99.9% of $^{90}Sr$, 79.65-80.3% of $^{137}Cs$ and $^{60}Co$ 45.5-55.5% in 90-110 min with were extracted in 10-30 min, respectively. The process of diffusion in liquid membranes is governed by the chemical diffusion process.

• 한국식품과학회지
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• 제26권6호
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• pp.740-744
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• 1994

본 연구는 녹차음료가 음용수나 식품에 오염된 중금속 (Pb, Cd)의 장내 흡수 억제효과가 있는지를 조사하기위해 장내 흡수 조건을 고려한 한외여과막을 이용한 in vitro 실험을 실시하였다. 납과 카드뮴이 수질기준의 10배 또는 100배로 오염된 음료수애서 단독오염의 경우 납은 녹차, 홍차에서 $50{\sim}70%$, 보리차에서 $30{\sim}40%$의 제거율을 보였으며 카드뮴은 녹차, 홍차에서 $30{\sim}40%$, 보리차에서 $10{\sim}20%$의 제거율을 나타냈다. 납과 카드뮴이 혼합오염된 경우는 단독오염보다 제거효과가 낮았는데 이는 다엽성분 및 여과막에 대한 두 금속원소의 흡착경합에 기인하는 것으로 생각된다. 다류 원료에서 음료틀 침출하는$70^{\circ}C$, 2분과 $95^{\circ}C$, 10분외 두 조건은 비슷한 중금속 제거율을 보였다. 녹차의 페놀성 물질인 tannic acid 와 gallicd acid도 비슷한 중금속 제거효과를 보였다.

• 미생물학회지
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• 제32권1호
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• pp.78-83
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• 1994

초산 생성 균주인 Acetobacter sp. HA로부터 membrane-bound alcohol dehydrogenase(ADH)를 분리 정제하였다. 세포막 분획과 세포막에서 효소의 용출 그리고 크로마토그라피 방법 등을 적용하여 수율 35%, 153배 정제된 효소를 획득하였다. 정제된 효소의 분자량은 330,000 dalton이었으며, 각각 분자량 79,000과 49,000 그리고 45,000 dalton을 가진 세 종류의 subunit로 이루어져 있었다. 그리고 흡수 스펙트럼의 분석 결과 본 효소에는 cytochrome c가 존재함을 확인할 수 있었다. 본 효소는 메탄올을 제외한 1차 지방족 알코올을 기질로 이용할 수 있었으며, formaldehyde, acetaldehyde 그리고 glutaraldehyde의 경우에도 다소간 기질로 이용될 수 있었다. 본 효소의 에탄올에 대한 $K_m$값은 1.38mM이었으며, 최적 pH와 온도는 각각 5.0~6.0과 32${\circ}C$이었다. 본 효소의 활성은 $V_2O_5$와 $ZnCl_2,\; NiCl_2$같은 금속 이온에 의하여 저해되었다.

• 한국어병학회지
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• 제28권2호
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• pp.113-116
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• 2015

A $0.45-{\mu}m$ membrane filter is generally used to remove bacterial contamination during virus extraction from fish samples. However, the number of fish viruses is drastically reduced after filtration with a $0.45{\mu}m$ filter. In this study, we investigated the effect of filters on virus infectivity titer and the change in virus titer and bacterial number following different centrifugation conditions to determine a suitable procedure for virus extraction from fish samples. $10^{4.05}$ and $10^{5.05}TCID_{50}/ml$ of infectious hematopoietic necrosis virus (IHNV) and $10^{4.05}$ and $10^{4.55}TCID_{50}/ml$ of Oncorhynchus masou virus (OMV) were not detectable after filtration with two types of $0.45-{\mu}m$ filters, except the IHNV titer was reduced by about 10 fold after filter use (company A). No significant difference was found in the virus titer following centrifugation at $880{\times}g$ (30 min) or $3,500{\times}g$ (30 min), whereas IHNV and OMV titers were reduced by about 10 and 10-1000 fold by centrifugation at $14,000{\times}g$ (30 min) and $14,000{\times}g$ (10 and 30 min), respectively. A total of 97.7-99.9% Escherichia coli were eliminated by centrifugation at $880 {\times}g$ (30 min) and $3,500{\times}g$ (30 min). These results show that fish viruses were affected by filtering, even though the effect differed by virus species and filter type. Therefore, centrifugation at $3,500{\times}g$ (30 min) and use of medium with antibiotics may be useful for virus extraction along with a reduction in bacteria.

• 한국물환경학회지
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• 제32권6호
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• pp.628-648
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• 2016

Increased attention has been paid to the presence of veterinary antibiotics in various environmental matrices due to their toxicological behavior in the ecosystem and development of antibiotic-resistant strains of pathogenic bacteria. In the this review, 37 target antimicrobials were selected based on annual sales of antibiotics for livestock in South Korea 2014. Also, extraction and clean-up methods for the determination of the antibiotic residues in liquid samples including water, milk, and honey were comprehensively reviewed in the literature. Solid-phase extraction (SPE) was commonly used as a pre-treatment method for the samples. Most of the analytes were extracted in acidic conditions (2.5~4.0) except for aminoglycosides, which were extracted in neutral conditions (7.0~8.0). ${\beta}-Lactams$ showed the highest recoveries in neutral pH due to their degradation characteristics in acidic media. Starta-X, Oasis HLB, and Oasis MCX were frequently applied as an SPE cartridge and Oasis HLB showed the highest recoveries for the majority of antibiotic classes. The homogenized honey and milk were extracted by mixing with acids for deproteinization. Solids and other interfering substances in the extract were eliminated by centrifugation followed by membrane filtration or SPE before injection into HPLC.

• Journal of Periodontal and Implant Science
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• 제46권6호
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• pp.415-425
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• 2016

Purpose: The present study investigated the impact of 2 different suture techniques, the conventional crossed mattress suture (X suture) and the novel hidden X suture, for alveolar ridge preservation (ARP) with an open healing approach. Methods: This study was a prospective randomized controlled clinical trial. Fourteen patients requiring extraction of the maxillary or mandibular posterior teeth were enrolled and allocated into 2 groups. After extraction, demineralized bovine bone matrix mixed with 10% collagen (DBBM-C) was grafted and the socket was covered by porcine collagen membrane in a double-layer fashion. No attempt to obtain primary closure was made. The hidden X suture and conventional X suture techniques were performed in the test and control groups, respectively. Cone-beam computed tomographic (CBCT) images were taken immediately after the graft procedure and before implant surgery 4 months later. Additionally, the change in the mucogingival junction (MGJ) position was measured and was compared after extraction, after suturing, and 4 months after the operation. Results: All sites healed without any complications. Clinical evaluations showed that the MGJ line shifted to the lingual side immediately after the application of the X suture by $1.56{\pm}0.90mm$ in the control group, while the application of the hidden X suture rather pushed the MGJ line slightly to the buccal side by $0.25{\pm}0.66mm$. It was demonstrated that the amount of keratinized tissue (KT) preserved on the buccal side was significantly greater in the hidden X suture group 4 months after the procedure (P<0.05). Radiographic analysis showed that the hidden X suture had a significant effect in preserving horizontal width and minimizing vertical reduction in comparison to X suture (P<0.05). Conclusions: Our study provided clinical and radiographic verification of the efficacy of the hidden X suture in preserving the width of KT and the dimensions of the alveolar ridge after ARP.