• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.56-66
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• 1993

The Langerhans cells are dendritic nonkeratinocytes found suprabasally in most stratified squamous epithelia, such as human epidermis and the epithelium of the oral mucosa including that of gingiva. After Paul Langerhans found it in the skin in 1968, there have been sturdies of it's function and distribution . Stingle et al. reported that the Langerhans cells seem able to present antigens and to stimulate T-lymphocytes. Shelley et al. discovered that they can take up contact allergens. Accordingly it has been suggested that Langerhans cells are important elements of p Peripheral cell mediated immune system. In this study, the gingival tissue of a adult periodontitis patient was taken and freeze dried. In one specimen, we used the CD1 monoclonal antbody to staining the Langerhans cell. The other specimen, we embedded in paraffin and staining it with S-100 monoclonal antibody. The purpose of this study was to use these specimens to find out the distribution, orientation, morphology of the Langerhans cell and to discover the increase or decrease of Langerhans cell in an increased inflammatory state. The results were obtained as follows : 1. Langerhans cells were distributed between the basal cell layer and spinous cell layer against the CD1 & S-100 monoclonal antibody. 2. Langerhans cessl were plentiful in the oral eptihelium, and there was very little in the sulcular epithelium. 3. There were no Langerhans cell in the junction epithelium and pocket lining epithelium. 4. The number of Langerhans cells that responsed to the CD1 & S-100 monoclonal antibody had a statistically difference. 5. As the infiltration of the lymphocyte into the connective tissue were increased, the number of Langerhans cells in the epithelium were increased. 6. As the inflammation was increased, Langerhans cells in the spinous cell layer were more increased than those of the basal layer.

• 대한치과의사협회지
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• 제58권5호
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• pp.276-283
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• 2020

Objectives: The aim of this study was to evaluate the efficacy of CK files as an ultrasonic instrument, and to determine most efficient file size for smear layer removal. Materials and Methods: Thirty-six extracted human mandibular premolars with single, straight root canals and mature apices were mechanically prepared and randomly divided into three groups. Group 1 (Control) underwent conventional needle irrigation, Group 2 (CKS) underwent passive ultrasonic irrigation with a #20 CK file, and Group 3 (CKL) underwent passive ultrasonic irrigation with a #30 CK file. After preparation and irrigation, all teeth were dried and split with a chisel to obtain the mesial and distal half of their roots. Each sample was evaluated using a scanning electron microscope, and data were analyzed using the Kruskal-Wallis and Mann-Whitney rank sum tests (p<0.05). Results: The CKS group showed less debris in the apical third than the other groups (p<0.05). In this section, no significant difference was observed among the other groups. And, there was no significant difference among any groups for the middle third section. Conclusion: This study showed that PUI with #20 CK file removed more smear layer compared to using #30 CK file at the apical third of the root canal.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.470-478
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• 1997

The purpose of this study was to investigate the effects of moistening mechods of dentin on the morphologic states of hybrid layers and on the interfacial bond strength between dentin and composite. Specimens were divided into 6 groups based on the surface moistening methods and materials used. After the dentin surface was conditioned with 10 % phoporic acid and irrigated: 1. The dentin surface was dried. Then bonding agent and composite were applied. 2. The dentin surface was blot-dryed. Then primer, bonding atent and composite were applied. 3. The dentin surface was dryed first. Within 20 seconds, the surface was rewetted, then primer, bonding agent and composite were applied. 4. The dentin surface was dryed. Then primer, bonding agnent and composite were applied. 5. The dentin surface was dryed first. Atter 24hrs, the surface was rewetted, and then primer, bonding agent and composite were applied. 6. The surface was conditioned with NaOCl for 5min. Then primer, bonding agent and composite were applied. To reveal the hybrid layer, scanning electron microscopy was used after the samples were ion beam etched. The shear bond strength of each group was tom pared by ANOVA. In groups 2, 3 and 4, the hybrid layer was clearly visible, but the width was more limited in group 4. In group 1 and 5, the hybrid layer was not found, and a gap was formed between dentin and composite. In group 6, the hybrid layer was not found, but the interface between the dentin and composite was intimate. The shear bond strength of each group was as follows: Group 1 : 4MPa, Group 2 : 14MPa, Group 3 : 12MPa, Group 4 : 14MPa, Group 5 : 5MPa, Group 6 : 9MPa.

• 생명과학회지
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• 제30권10호
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• pp.860-866
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• 2020

본 연구는 음식폐기물을 활용하여 갈색거저리를 사육한 후에 산란계에 급이시 나타나는 계란의 특성을 분석하기 위해 수행되었다. 계란의 두께는 처리군에서 약간 얇아지는 경향성을 보였지만, 신선도를 나타내는 Haugh unit는 처리군이 대조군에 비교하여 높아지는 것으로 나타났고, 특히 5%가 가장 높았다. 난황의 색상은 5% 급이 군에서 명도와 황색도가 낮아지는 반면에 적색도가 증가되는 경향성을 보였다. 5% 급이군은 조지방과 조단백이 대조군과 유사하게 형성되는 것으로 나타났지만, 10%와 15% 급이군들은 대조군보다 조지방 및 조단백 함량이 낮은 것으로 나타났다. 그러나 탄수화물 함량은 10%와 15% 급이군들에서 높게 형성되는 것으로 관찰되었다. 처리군들에서 구성아미노산은 대조군에 비교하여 필수아미노산보다 비필수아미노산의 비율의 증가가 높은 것으로 나타났다. 항산화물질의 지표가 되는 폴리페놀의 함량은 5% 급이군에서 가장 높은 것으로 나타났기 때문에, 계란의 저장성 및 항산화에 영향을 줄 수 있는 것으로 추정된다. 따라서 고단백 및 고지방 사료인 갈색거저리를 보충 사료원으로 활용할 때 계란의 영양성분 함량에 중용한 변화를 유발할 수 있고 계란의 신선도를 개선할 수 있는 것으로 제의된다.

• 한국재료학회지
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• 제14권12호
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• pp.893-899
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• 2004

Even though Ti-6Al-4V has gained popularity as an implant material, the possible dissolution of Al and V ions in body fluids remains a matter of concern. Though commercially pure Ti (Cp-Ti) overcomes this problem, the mechanical strength of pure titanium remains very low. Thus, in this experiment Cp-Ti was processed by Equal channel angular processing (ECAP), in order to increase the mechanical strength. The biocompatibility of ECAP-Ti, Cp-Ti and Ti-6Al-4V was examined by the apatite formation on each sample surface, after treating the surface with 5M NaOH and soaking in Simulated body fluids (SBF). Initially, the samples were mechanically polished on silicone carbide paper (#2000). The polished samples were treated with 5M NaOH solution at $60^{\circ}C$ for 24 hours. The NaOH treated samples were washed gently with distill water and dried at $40^{\circ}C$ for 1 day. The dried samples were heat treated in air at $600^{\circ}C$ for 1 hour. The surface morphology of these samples were studied using SEM and XRD. The SEM studies showed network of pores in all samples. The XRD showed oxide layer formation on Cp-Ti and Ti-6Al-4V. samples. However the oxide layer in ECAP-Ti was not substantial. These samples were immersed in SBF, kept at $36.5^{\circ}C$ for seven days period. At the end of 7 days, the apatite formation was confirmed only on Cp-Ti and was not observed in Ti-6Al-4V and ECAP-Ti. These observations of apatite formation relate to the fact that Cp-Ti showed greater oxide layer than other samples. The apatite examined was confirmed as tricalcium phosphate (TCP) using EDS and XRD.

• Journal of Periodontal and Implant Science
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• 제25권1호
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• pp.76-88
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• 1995

The purpose of this was to evaluate the in vitro effects of different application modes of tetracycline HCI on dentin root surfaces. The study group was comprised of 30 teeth with advanced periodontal disease extracted before the start of periodontal therapy. The diseased root surface was vigorously root planed to expose dentin. The teeth were sectioned and cotton pellets. soaked in a saturated solution of tetracycline HCI, were either "placed" or "burnished" on the prepared root surface for 3, 5 min. respectively. Control surfaces were similarly treated with root planing only. Following the various treatments, teeth were fixed. dehydrated, critical point dried, and coated for scanning electron microscopic(SEM) evaluation. The surfaces of tetracycline HCI treated specimens considerably differed from specimens treated with root planing only. Results demonstrated that root-planed, no-tetracycline HCI specimens had amorphous, irregular surface which corresponded to a smear layer. Tetracycline HCI specimens exhibited collagen fibers and dentinal tubules exposed by the removal of the smear layer. Although some differences were seen in surface structures among some specimens. "burnished" application causes more extensive change than "placed" application, and application time of the tetracycline HCl did not seem to have any major impact on the surface morphology.

• 한국식품과학회지
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• 제25권4호
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• pp.313-320
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• 1993

동결건조에서 승화 건조시간을 예측하기 위하여 수학적 모델링과 지배방정식을 설정하고, 당근즙을 대상으로 수치계산하여 실험값과 비교한 바, 수분함량이 많은 동결건조품에서 단위면적당 승화량을 높일 수 있는 재료의 두께는 전도 열전달 방식에서 5mm이었으며, 양면 복사방식에서는 10mm이었다. 또한 동일한 압력에서 응축기 온도가 낮을수록 당근즙의 승화시간은 짧았고, 압력이 높을수록 승화시간은 선형적으로 증가하였다. 그리고 동결건조 효율이 가장 좋은 열전달 방법으로는 전도 및 복사방식으로 상, 하의 플레이트 온도를 $T_x{\leq}T_m$와 $T_m{\leq}T_x$의 제한 조건하에서도 별도 제어하는 방식이었다.

• Applied Biological Chemistry
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• 제34권4호
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• pp.334-338
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• 1991

고상법으로 새로운 반응기구에 의한 bradykinin 및 $(D-Phe7\;-Leu^8)$ bradykinin을 합성하였다. Coupling은 N, N'-dicyclohexylcarbodiimide로 행하였으며 HBr 용액으로 cleavage한 후 조펩티드는 high pressure liquid chromatography로 정제하였다. 이들 펩티드의 순도는 paper chromatography, thin layer chromatography, paper electrophoresis, 융점측정기 및 아미노산기분석기에 의하여 분석하였다. Endopeptidase인 ${\alpha}-chymotrypsin$과 trysin, exopeptidase인 carboxypeptidase A와 leucine aminopeptidase를 사용하여 in vitro 상에서 이들 펩티드의 분해실험을 하였다. ${\alpha}-Chymotrypsine$ 및 carboxypeptidase A에 의하여 이들 펩티드는 빠르게 분해하였으나 leucine aminopeptidase는 N-말단의 2번 위치에 proline의 imino결합 때문에 분해하지 않았다.

• E2M - 전기 전자와 첨단 소재
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• 제10권10호
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• pp.983-988
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• 1997

We investigated the structural and dielectric properties of PZT(20/80)/PZT(80/20) heterolayered thin films that fabricated by the alkoxide-based Sol-Gel method. PZT(20/80)/PZT(80/20) heterolayered thin films were spin-coated on the Pt/Ti/SiO$_2$/Si substrate with PZT(20/80) film of tetragonal structure and PZT(80/20) film of rhombohedral structure by turns. Each layers were dried to remove the organic materials at 30$0^{\circ}C$ for 30min and sintered at $650^{\circ}C$ for 1hr. This procedure was repeated several times to form PZT(20/80)/PZT(80/20) heterolayered films and thickness of the film obtained by one-times of drying/sintering process was approximately 80-90nm. PZt-1, 3, 5 films with top layer of PZT(20/80) film of tetragonal structure showed fine grain structure and PZT-2, 4, 6 films with top layer of PZT(80/20) film of rhombohedral structure showed the dense grain microstructure without rosette-type. Dielectric constant and dielectric loss of the PZT-6 film were approximaterly 1385 and 3.3% respectively. Increasing the number of coatings remanent polarization was increased and coercive field was decreased and the values of the PZT-6 film were 8.13$\mu$C/cm$^2$and 12.5kV/cm respectively.

• 한국작물학회지
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• 제46권3호
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• pp.221-228
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• 2001

1. 현미를 상온저장시 2주까지는 발아율에 차이가 없으나, 저장 3주후부터는 발아율이 급격히 감소되어 발아율이 80%에 미치지 못하기 때문에 발아현미의 재배를 위해서는 도정후 2주 이내의 현미를 사용하는 것이 바람직한 것으로 판단되었다. 2. 24시간 침종처리가 무침종에 비하여 현미의 초기발아율이 약 2-3%증가되었고, $25^{\circ}C$는 현미의 발아율과 생육상태가 좋았을 뿐만 아니라 부패발생도 적었다. 3. 동결건조된 발아현미는 열풍건조된 발아현미와는 달리 호분층 및 내배유부분의 분리현상이 발생되었고, 배유의 전분 저장세포뿐만 아니라 전분립간의 균열현상이 관찰되었다. 4. 열풍건조는 동결건조 보다 유리하였고, 55$^{\circ}C$로 48시간 건조시 발아현미의 불쾌취가 제거되었다. 5. 조단백 및 amylose는 발아일수가 경과함에 따라 함량의 변화가 미미하였으나 조회분, 조섬유 및 유리당은 발아일수가 경과함에 따라 감소되었고, 조지방과 총아미노산의 함량은 증가하였다. 6. $\alpha$-amylase활력은 발아 5일부터 급격히 증가하다가 발아 8일부터 감소되는 경향이었다. 7. 유리당의 함량은 발아기간(0-8일)중 지속적으로 감소되는 경향이었으며 sucrose와 glucose의 감소가 현저하였고 발아 5일 이후 fructose와 maltose는 증가되었다.