• 펄프종이기술
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• 제43권1호
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• pp.74-82
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• 2011

The bast fiber of Paper mulberry has been generally used as a fibrous raw material in traditional Hanji-making. Nowadays, its uses is expanded to different special purposes such as paper mulberry yarn, laminated paper, antimicrobial paper depending on its application. Despite the wide array of the use of mulberry fibers, it is still limited due to some difficulties in the automation process of manufacturing works. This study is focused on the analysis of chemical components and morphological properties of paper mulberry bark for the automation of bark peeling process. The bast tissue of paper mulberry was separated in three plies; black outer layer, green inner layer, and white inner layer. The total lignin content, holocelluloses, extractives and ashes, and the anatomical structure of the three layers in mulberry bark tissue were investigated. The analysis showed that the black outer layer is composed of about 50% of total lignin content, whereas the white inner layer is composed of about 90% of holocellulose content.

• 대한소아치과학회지
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• 제40권3호
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• pp.216-222
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• 2013

감염된 미성숙 영구치의 치수치료에 있어 줄기세포의 분화를 유도하는 생활조직의 재생과 지속적인 치근형성을 도모하는 방향으로 패러다임이 전환되고 있는데, 여기에서는 소독, 스캐폴드(scaffold), 그리고 폐쇄가 중요하다. 소독을 위해 triple antibiotics가 널리 사용되고 있으며, 스캐폴드로써 기존의 혈병대신 platelet-rich fibrin의 사용이 보고되었다. 본 증례보고에서는 치외치 파절에 의해 치수가 감염된 미성숙 영구치에서 platelet-rich fibrin을 스캐폴드로써 이용한 치수 재혈관화를 시행하였다. 발수와 근관세척 후 첫 증례에서 국소적 항생제의 적용 없이 platelet-rich fibrin을 단독 사용하였고 두 번째와 세 번째 증례에서는 국소적 항생제 적용 후 platelet-rich fibrin을 적용하였는데 모두 양호한 치유 결과를 얻었다.

• 대한소아치과학회지
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• 제43권4호
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• pp.419-426
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• 2016

본 연구는 상악 매복 과잉치를 가지고 전신질환 및 의과 병력이 없는 만 5 - 9세 사이의 남녀 20명으로부터 서면동의를 얻고 상악 전치부에 매복된 과잉치를 발치하고 치수세포를 채취하였다. 채취 후 세포의 1차 배양 동안 오염된 3명(남자 2명, 여자 1명)을 제외하고 총 17명(남자 10명, 여자 7명)을 대상으로 하였다. 이번 연구에서 과잉치 치수조직으로부터 유래한 세포의 계대 배양에 소요된 평균 시간은 $2.91{\pm}0.29$일이었다. 최초 치수조직으로부터 세포를 얻은 후 80% confluency를 얻는데 소요되는 시간이 $4.53{\pm}0.94$일로 가장 많이 걸렸고, 이후 계대부터는 $2.73{\pm}0.32$일이 소요되었다. 남자의 비율은 58.82%, 여자의 비율은 41.18%이었다. 여자의 평균 소요시간은 $2.81{\pm}0.27$일 이었으며, 남자는 $2.98{\pm}0.29$이었다. 과잉치가 역위된 비율은 82.35%, 정위 비율은 17.65%였다. 평균 계대 소요 배양 시간은 역위가 $2.94{\pm}0.30$일, 정위는 $2.80{\pm}0.20$일이었다. 원뿔형(Conical type)은 76.47%였고, 그 외 형태는 23.53%였다. 원뿔형의 평균 소요시간은 $2.92{\pm}0.31$이었고, 그 외 형태의 소요 시간은 $2.88{\pm}0.22$이었다. 매복 방향과 형태에 따른 계대 배향 시간은 통계적으로 유의한 차이를 보이지 않았다. 향후 초기 계대와 후기 계대에서 얻어진 세포의 줄기세포로써의 능력을 평가하는 후속 연구들이 필요하며, 3일 이내의 계대 배양 시간이 소요된 점을 고려할 때, 연구의 효율성과 빠른 배양시간 등은 과잉치 유래세포가 치아유래 줄기세포의 연구에 활용가능성이 충분하리라 판단되었다.

• 대한수의학회지
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• 제25권2호
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• pp.113-123
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• 1985

This paper dealt with the distribution of normal mast cells in the spleen, liver and lung on cattle, horses, pigs and dogs, and also degranulation of mast cells in the dogs infected with Rompun (2% Xylazine HCl). The results observed are summarized as follows. Normal mast cells were distributed in spleen, liver and lung on cattle, horse, pig and dog. Mast cells were observed in both red pulp and surroundings of white pulp of the spleen in horse, in the white pulp of the spleen in cattle, in the trabeculae of the spleen in pigs, and in white pulp and red pulp of the spleen in dogs, respectively. Mast cells were observed in the portal triad of the liver in cattle and horses, in both portal triad and interlobular connective tissues of the liver in pigs, and not only the portal triad but also walls of the sinusoids and the central veins in dogs. A large number of mast cells were observed in the interlobular septa and peribronchioles of lung on all the species in this experiment. The mast cells are more numerous in the lungs than other organs. Author considers that numbers of normal mast cells distributed in the tissue is related to the dosage of Rompun in animal. The degranulation of mast cells were observed in the subcutaneous tissues of dog intramuscularly injected with Rompun(0.5ml/times) for 4 or 5 times and subcutaneously injected with Rompun(0.3ml/times) for 4 times. In dog intradermally injected with 0.1ml of Rompun, mast cells were decreased in number at 30 minutes and markedly decreased in number at 2 hours, but more or less increased in number at 3 hours after injection. In addition, the granules of the mast cells were decreased in number at 30 minutes and marked degranulation of the mast cells were recognized at 2 hours after injections, but normal mast cells begun to appear in subcutaneous tissue with the lapse of time from 3 hours after injection. There was also observed local infiltration of neutrophils in subcutaneous tissues of dogs intradermally injected with 0.1ml of Rompun at 30 minutes. At 2 hours after injection, numerous neutrophils and a small number of eosinophils were observed in the site of injection. Conclusionally, Rompun was regarded as a factor which causes the degranulateon of mast cell and the authors considered that histamine released from the mast cells by Rompun might cause relaxation of skeletal muscle.

• Restorative Dentistry and Endodontics
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• 제21권2호
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• pp.451-469
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• 1996

The purpose of this study was to investigate the effect of calcium hydroxide and glass ionomer cement fillings on the levels of $LTB_4$ and $LTC_4$ in experimentally inflamed rat dental pulp. The dental pulp in the mandibular incisor of wistar rat was irritated by cutting a 5mm deep hole in the dentin with a twist drill bur of 0.5mm diameter, without cooling. The cavities were filled with calcium hydroxide(light-cured) and glass ionomer cement(light cured). The untreated pulp served as control tissue specimen. After cavity preparations, the rat with or without various treatment were sacrificed in various time by decapitation. The dental pulp tissue were carefully removed and the concentrations of $LTB_4$ and $LTC_4$ were determined by radioimmunoassay. And pulps were examined histologically to observe inflammatory feature. The result were obtained as follows : 1. The inflammatory features of pulps were observed microscopically in all experimental groups. And degree of inflammation was decreased with time. 2. The concentrations of $LTB_4$ and $LTC_4$ for all experimental groups were significantly higher than those for control group 6 hours after cavity preparation(p<0.05). 3. The group filled with calcium hydroxide was the lowest, and the group filled with glass ionomer cement, the group of irritation in that order showed increased concentrations of $LTB_4$ and $LTC_4$ 6 hours after cavity preparation. In the concentrations of $LTB_4$, significant differences among 3 groups were noted(p<0.05). 4. The group filled with calcium hydroxide was the lowest, and the group filled with glass ionomer cement, the group of irritation in that order showed increased concentrations of $LTB_4$ and $LTC_4$ 24 hours after cavity preparation. And there were statistically significant difference in concentrations of $LTB_4$ between the group of irritation and the group filled with calcium hydroxide(p<0.05). 5. The group filled with calcium hydroxide was the lowest, and the group filled with glass ionomer cement, the group of irritation in that order showed increased concentrations of $LTB_4$ and $LTC_4$ 48 hours after cavity preparation. But no statistically difference was found (p>0.05). 6. The concentrations of $LTB_4$ and $LTC_4$ in all experimental groups were highest level at 6 hour after experiment and decreased as time progresses(correlation coefficient>0.8).

• International Journal of Oral Biology
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• 제37권2호
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• pp.77-83
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• 2012

We investigated the pulpal response to direct pulp capping in rat molar teeth using mineral trioxide aggregate (MTA) and calcium hydroxide (CH). A palatal cavity was prepared in rat maxillary molar teeth. Either MTA or CH was placed on the exposed pulp and all cavities were restored with composite. Rats were sacrificed for histological evaluation after 12 hours and at 2, 7, 14 and 21 days. In both the MTA and CH groups, reparative dentin formation was clearly observed on histology after 14 days. The MTA-capped pulps were found to be mostly free from inflammation, and hard tissue of a tubular consistent barrier was observed. In contrast, in CH-capped teeth, excessive formation of reparative dentin toward residual pulp was evident. The pulpal cell response beneath the reparative dentin layer was examined by immunofluorescence using antibodies against DSP. After 2 days, a few DSP immunopositive cells, most of which showed a cuboidal shape, appeared beneath the predentin layer. At 7 days, DSP-immunopositive cells with columnar odontoblast-like cells were seen beneath the newly formed hard tissues. At 14 and 21 days, DSP was more abundant in the vicinity of the odontoblastic process along the dentinal tubules than in the mineralized reparative dentin. The CH group showed strong expression patterns in terms of DSP immunoreactivity. Our results thus indicate that MTA may be a more effective pulp capping material as it induces the differentiation of odontoblast-like cells and the formation of reparative dentin without the loss of residual pulp functions.

• Restorative Dentistry and Endodontics
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• 제35권6호
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• pp.473-478
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• 2010

연구목적: 본 연구는 인간의 치수 및 치근단 조직에서 유리된 세포를 이용하여 비교적 최근 소개된 Bioaggregate의 생체친화성을 평가하는 데에 있다. 연구 재료 및 방법: 사람의 발거치로 부터 치수 및 치근단 조직에서 배양된 세포를 이용하였다. Bioaggregate와 white MTA를 혼합하여 세포배양판에 적용한 후 같은 수의 세포를 배양하였다. 1, 3, 그리고 7일 후 위상차현미경을 사용하여 세포의 부착과 성장을 관찰하고 cell viability test를 시행하였다. 얻어진 결과는 Student t-test및 one way ANOVA를 이용하여 분석하였다. 결과: 두가지 종류의 세포 모두 Bioaggregate와 MTA가 혼합된 배양판에서 잘 성장하였으며 Bioaggregate군에서는 inhibition zone이 관찰되지 않았다. Cell viability test에서 두 그룹간 통계적인 유의성 차이는 없었다. 결론: Bioaggreagete는 치수 및 치근단 세포에 대하여 MTA와 유사한 세포친화성을 보였다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.311-316
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• 2006

The role of short fibre pulp - Mixed Harwood, Eucalyptus, Aspen, Birch, etc for the manufacture of different grades of paper is very well recognized. At the same time, lots of efforts are in progress to maximize the advantages while preserving their own special property. Bleached Acacia Kraft Pulp (BAKP) is comparatively new entry but gained quick recognition. BAKP was introduced to the world market by South East Asian suppliers in the late 1990's. This paper discusses in detail the role and opportunities of use of short fibre pulps. A logical technical comparison has been made between BAKP and another short fibre grades. BAKP being a short, thin-walled fibre shows several similarities with Eucalyptus pulp in terms of good bulk and stiffness. Refining energy and strength properties are very similar, but the shorter fibres and thinner cell walls give an outstanding opacity and formation compared to other commercial short fibre pulps. The collapsed and band-shaped nature gives a matchless smoothness, enabling less calendaring and exceptional printing properties. BAKP is shown to give several advantages to fine paper manufactures, compared with a number of established short fibre pulps such as Brazilian and Chilean Eucalyptus, Canadian Aspen and Indonesian Mixed Hardwood. It is important to consider refining and calendaring conditions to achieve optimum performance. For outer layers of multiply board, Acacia gives excellent coverage due to its high opacity and uniform fibre distribution. Its low roughness property gives improved printability. For tissue products, Acacia gives unique property of superior softness both in terms of hand feel and bulk softness. The high fibre population gives an impression of much higher quality due to the higher opacity and good formation.

• Tissue Engineering and Regenerative Medicine
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• 제15권6호
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• pp.735-750
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• 2018

BACKGROUND: The major challenge of tissue engineering is to develop constructions with suitable properties which would mimic the natural extracellular matrix to induce the proliferation and differentiation of cells. Poly(${\varepsilon}$-caprolactone)-poly(ethylene glycol)-poly(${\varepsilon}$-caprolactone) (PCL-PEG-PCL, PCEC), chitosan (CS), nano-silica ($n-SiO_2$) and nano-hydroxyapatite (n-HA) are biomaterials successfully applied for the preparation of 3D structures appropriate for tissue engineering. METHODS: We evaluated the effect of n-HA and $n-SiO_2$ incorporated PCEC-CS nanofibers on physical properties and osteogenic differentiation of human dental pulp stem cells (hDPSCs). Fourier transform infrared spectroscopy, field emission scanning electron microscope, transmission electron microscope, thermogravimetric analysis, contact angle and mechanical test were applied to evaluate the physicochemical properties of nanofibers. Cell adhesion and proliferation of hDPSCs and their osteoblastic differentiation on nanofibers were assessed using MTT assay, DAPI staining, alizarin red S staining, and QRT-PCR assay. RESULTS: All the samples demonstrated bead-less morphologies with an average diameter in the range of 190-260 nm. The mechanical test studies showed that scaffolds incorporated with n-HA had a higher tensile strength than ones incorporated with $n-SiO_2$. While the hydrophilicity of $n-SiO_2$ incorporated PCEC-CS nanofibers was higher than that of samples enriched with n-HA. Cell adhesion and proliferation studies showed that n-HA incorporated nanofibers were slightly superior to $n-SiO_2$ incorporated ones. Alizarin red S staining and QRT-PCR analysis confirmed the osteogenic differentiation of hDPSCs on PCEC-CS nanofibers incorporated with n-HA and $n-SiO_2$. CONCLUSION: Compared to other groups, PCEC-CS nanofibers incorporated with 15 wt% n-HA were able to support more cell adhesion and differentiation, thus are better candidates for bone tissue engineering applications.

• Journal of Periodontal and Implant Science
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• 제43권6호
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• pp.315-322
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• 2013

Purpose: In this study, we investigated the effect of silk scaffolds on one-wall periodontal intrabony defects. We conjugated nano-hydroxyapatite (nHA) onto a silk scaffold and then seeded periodontal ligament cells (PDLCs) or dental pulp cells (DPCs) onto the scaffold. Methods: Five dogs were used in this study. Bilateral 4 mm${\times}$2 mm (depth${\times}$mesiodistal width), one-wall intrabony periodontal defects were surgically created on the distal side of the mandibular second premolar and the mesial side of the mandibular fourth premolar. In each dog, four of the defects were separately and randomly assigned to the following groups: the PDLCcultured scaffold transplantation group (PDLC group), the DPC-cultured scaffold transplantation group (DPC group), the normal saline-soaked scaffold transplantation group, and the control group. The animals were euthanized following an 8-week healing interval for clinical, scanning electron microscopy (SEM), and histologic evaluations. Results: There was no sign of inflammation or other clinical signs of postoperative complications. The examination of cellseeded constructs by SEM provided visual confirmation of the favorable characteristics of nHA-coated silk scaffolds for tissue engineering. The scaffolds exhibited a firm connective porous structure in cross section, and after PDLCs and DPCs were seeded onto the scaffolds and cultured for 3 weeks, the attachment of well-spread cells and the formation of extracellular matrix (ECM) were observed. The histologic analysis revealed that a well-maintained grafted volume was present at all experimental sites for 8 weeks. Small amounts of inflammatory cells were seen within the scaffolds. The PDLC and DPC groups did not have remarkably different histologic appearances. Conclusions: These observations indicate that nHA-coated silk scaffolds can be considered to be potentially useful biomaterials for periodontal regeneration.