• Title/Summary/Keyword: Regeneration rate

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A study of bone regeneration effect according to the two different graft bone materials in the cranial defects of rabbits

  • Song, Hyun-Jong;Kim, Hyun-Woo;Min, Gwi-Hyeon;Lee, Won-Pyo;Yu, Sang-Joun;Kim, Byung-Ock
    • Oral Biology Research
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    • v.42 no.4
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    • pp.198-207
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    • 2018
  • Guided tissue regeneration (GBR) has been used to promote new bone formation in alveolar bone reconstruction at defective bone sites following tooth loss. Bone grafts used in GBR can be categorized into autogenous, xenogenous, and synthetic bones, and human allografts depending on the origin. The purpose of this study was to compare the rates of bone regeneration using two different bone grafts in the cranial defects of rabbits. Ten New Zealand rabbits were used in this study. Four defects were created in each surgical site. Each defect was filled as follows: with nothing, using a 50% xenograft and 50% human freeze-dried bone allograft (FDBA) depending on the volume rate, human FDBA alone, and xenograft alone. After 4 to 8 weeks of healing, histological and histomorphometric analyses were carried out. At 4 weeks, new bone formation occurred as follows: 18.3% in the control group, 6.5% in group I, 8.8% in group II, and 4.2% in group III. At 8 weeks, the new bone formation was 14.9% in the control group, 36.7% in group I, 39.2% in group II, and 16.8% in group III. The results of this study suggest that the higher the proportion of human FDBA in GBR, the greater was the amount of clinically useful new bone generated. The results confirm the need for adequate healing period to ensure successful GBR with bone grafting.

Effect and stability of miniscrew-assisted rapid palatal expansion: A systematic review and meta-analysis

  • Huang, Xinyi;Han, Yu;Yang, Shuangyan
    • The korean journal of orthodontics
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    • v.52 no.5
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    • pp.334-344
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    • 2022
  • Objective: This study aimed to systematically analyze the effect and stability of miniscrew-assisted rapid palatal expansion (MARPE) to provide a reference for the clinical treatment of patients with maxillary transverse deficiency (MTD). Methods: We searched PubMed, Science Direct, Web of Science, Embase, Cochrane Library, CNKI, and Wanfang Database for relevant studies published before February 18, 2021 and selected them according to the eligibility criteria. The Cochrane Handbook for Systematic Reviews (version 5.1.0) criteria were used for the quality assessment of randomized controlled trials, while the scoring protocol of the methodological index for non-randomized studies was used for non-randomized controlled trials. Statistical analysis was performed using the RevMan5.3 software. Results: All the included studies showed a relatively high success rate of expansion. The changes in both the intermolar and alveolar widths after MARPE were statistically significant. MARPE exhibited greater skeletal expansion effects than did conventional RPE. The midpalatal suture was opened in parallel after MARPE. A small amount of relapse was observed 1 year after expansion. MARPE caused tooth inclination and a decrease in alveolar height, but it was less significant than in conventional RPE. Conclusions: MARPE may be an effective treatment modality for patients with MTD. It causes great transverse skeletal expansion in late adolescence. In comparison to conventional RPE, MARPE has lower detrimental periodontal effects and has certain clinical advantages.

Oral Administration of Lactilactobacillus curvatus LB-P9 Promotes Hair Regeneration in Mice

  • Mikyung Song;Jaeseok Shim;Kyoungsub Song
    • Food Science of Animal Resources
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    • v.44 no.1
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    • pp.204-215
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    • 2024
  • This study was designed to examine the effect of Lactilactobacillus curvatus LB-P9 on hair regeneration. The treatment of LB-P9 conditioned medium increased the proliferation of both hair follicle dermal papilla cells and hair germinal matrix cells (hGMCs). Moreover, the expression levels of hair growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor 7 were significantly elevated in hGMCs co-cultured with LB-P9. After time-synchronized depilation, mice were orally administered with either 4×107 colony forming unit (CFU) of LB-P9 (low dose) or 4×108 CFU of LB-P9 (high dose), once daily for 4 weeks. Compared with the vehicle (phosphate-buffered saline)-administrated group, the LB-P9-treated groups exhibited accelerated hair regrowth rate and enhanced hair thickness in a dose-dependent manner. Supporting this observation, both hair follicle numbers and the dermal thickness in skin tissues of the LB-P9-treated groups were increased, compared to those of the vehicle-treated group. These results might be explained by the increased level of β-catenin and number of hair follicle stem cells (CD34+ CD49f+ cells) in the skin tissues of mice administered with LB-P9, compared to the vehicle-treated mice. Also, increased serum levels of hair growth factors such as VEGF and insulin-like growth factor-1, and superoxide dismutase were found in the LB-P9-treated groups, compared to those of the vehicle-treated group. Taken together, these results might demonstrate that the oral administration of LB-P9 promotes hair regeneration by the enhancement of dermal papilla proliferation through the stimulation of hair growth factor production.

Status of Bioactive Glass (생체 활성 유리 국내외 현황)

  • Kim, Hyeong-Jun
    • Ceramist
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    • v.21 no.3
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    • pp.216-232
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    • 2018
  • The average life span is over 80 years of age, and various biomaterials have being studied. Many research institutes and companies around the world have been commercializing bioactive glass through R&D, however, there is not much research in Korea. Most bioactive glass is applied to bone regeneration in powder form due to its excellent bio-compatibility. Recently, new applications such as scaffolds for tissue engineering and nerve regeneration have been found in composite form. The global market size is not as large as US $ 556 million in 2019, but the growth rate is very high at a CAGR of 14.35 %. This field is waiting for the challenge of new researchers.

The Limiting Current Density and the Regeneration of a Heterogeneous Ion Exchange Membrane in a Nickel Plating Rinse Waters Treatment Process by Electrodialysis (전기투석에 의한 니켈도금 폐수처리 공정에서 한계전류밀도와 불균질 이온교환막의 재생)

  • 윤용수
    • Journal of environmental and Sanitary engineering
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    • v.16 no.2
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    • pp.38-46
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    • 2001
  • In this work, the heterogeneous ion exchange membrane was used in a electrodialysis apparatus to treat a Ni planting rinse water because the heterogeneous ion exchange membrane was excellent efficiency as compared with low manufacturing cost, was easy to make, and had a good mechanical properties. For a regeneration of membrane and to obtain the optimal condition for a scale-up of apparatus after treating Ni plating rinse water, we would find about the limiting current density and the concentration polarization. When the Ni plating rinse water 150mg/L was treated with the electrodialysis apparatus using the heterogeneous ion exchange membrane, the limiting current density was about $1.49{\;}mA/\textrm{cm}^2$. And the limiting current density increased with the flow rate and concentration of Ni plating rinse water. We recognized that the used membrane could be reused by periodic backwashing because efficiency was constant when the membrane was backwashed after treating wastewater.

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The Application of Dump Combustor for Evaluation of DPF(Diesel Particulate Filter) System (DPF 성능 평가를 위한 Dump Combustor의 활용)

  • Nam, Youn-Woo;Lee, Won-Nam;Oh, Kwang-Chul;Lee, Chun-Beom
    • 한국연소학회:학술대회논문집
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    • 2007.05a
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    • pp.98-103
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    • 2007
  • The number of vehicles employing diesel engines is rapidly rising. Accompanying this trend, application of an after-treatment system is strictly required as a result of reinforced exhaust regulations. The Diesel Particulate Filter (DPF) system is considered as the most efficient method to reduce particulate matter (PM), but the improvement of a regeneration performance at any engine operation point presents a considerable challenge by itself. Temperature, gas compostion and flow rate of exhaust gas are important parameters in DPF evaluation, especially regeneration process. Engine dynamometer and degment tester are generally used in DPF evaluation so far. But these test method couldn't reveal the effect of various parameters on real DPF, such as O2 concentration, amount of soot and exhaust gas temperature. This research has studied the possibility using dump combustor that used to take an approach lean premixed combustion in gas turbine for a DPF power and optimized. It is possible that utilize the system as DOC (Diesel Oxidation Catalyst) and SCR(Selective Catalytic Reduction) assessments test as well as DPF evaluation

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Conservative surgical approach to aggressive benign odontogenic neoplasm: a report of three cases

  • Kumar, Vijay
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.41 no.1
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    • pp.37-42
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    • 2015
  • Aggressive benign odontogenic neoplasms have substantial potential to grow to an enormous size with resulting bone deformities, and they often invade adjacent tissues and spread beyond their normal clinical and radiographic margins; as such, they have a high rate of recurrence. Historically, management (conservative versus aggressive) on the basis of clinical, radiographic and/or histopathologic characteristics has been controversial. However, recent advances in the understanding of the biological features of these lesions may provide greater evidence of the benefits of conservative management. Three patients with different complaints and final histopathologic diagnoses were enrolled in the study. All three cases were treated by a single operator with similar conservative surgical procedures. During follow-up, the patients had uneventful secondary healing and bone regeneration, less packing time than previously reported, no clinical or radiographic evidence of recurrence and no apparent deformity. The aggressive behavior of these lesions requires long clinical and radiographic follow-up. Conservative surgical management may be an option to reduce recurrence and morbidity and increase the probability of uneventful secondary healing and bone regeneration.

Substituent Effect in the Reaction of Carbon Dioxide with Amine-Based Absorbent (치환기 특성에 따른 아민흡수제와 CO2의 반응특성 평가)

  • Shim, Jae-Goo;Lee, Junghyun;Jung, Jin-Kyu;Kwak, No-Sang
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.3
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    • pp.297-303
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    • 2020
  • The reaction of carbon dioxide with the amine-based absorbents which have various substituents in the molecule was described. In the case of MEA which is a representative primary amine, the absorption reaction was proceeded very fast while the regeneration reaction was took place slowly due to the strong bond strength between the absorbent and carbon dioxide. The more substituents on N atom of the absorbent, the slower the absorption reaction between carbon dioxide and the absorbent, which in turn causes faster the regeneration rate from the reaction intermediate, carbamate.

Optimum Operating Condition of Air Heating Solar Collector Regenerator Using RSM Technique (RSM 기법을 애용한 태양열 집열판 재생기의 운전 조건 최적화)

  • Jung Jae-ho
    • Proceedings of the KAIS Fall Conference
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    • 2004.06a
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    • pp.89-91
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    • 2004
  • This study examines a regeneration process using hot air heated by solar radiation to recover absorption potential by evaporating moisture in liquid desiccant. More specifically, this study is aimed at finding the optimum operating condition of the regenerator by utilizing a well-established statistical tool, so-called design of experiment, and optimization techniques. It is demonstrated that an optimization model to find the optimum operating condition can be obtained using the functional relationship between regeneration rate and affecting factors which is approximated on the basis experimental results.

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Endothelial cell autophagy in the context of disease development

  • Basheer Abdullah Marzoog
    • Anatomy and Cell Biology
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    • v.56 no.1
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    • pp.16-24
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    • 2023
  • Endothelial cells (EC) are the anatomical boundaries between the intravascular and extravascular space. Damage to ECs is catastrophic and induces endothelial cell dysfunction. The pathogenesis is multifactorial and involves dysregulation in the signaling pathways, membrane lipids ratio disturbance, cell-cell adhesion disturbance, unfolded protein response, lysosomal and mitochondrial stress, autophagy dysregulation, and oxidative stress. Autophagy is a lysosomal-dependent turnover of intracellular components. Autophagy was recognized early in the pathogenesis of endothelial dysfunction. Autophagy is a remarkable patho (physiological) process in the cell homeostasis regulation including EC. Regulation of autophagy rate is disease-dependent and impaired with aging. Up-regulation of autophagy induces endothelial cell regeneration/differentiation and improves the function of impaired ones. The paper scrutinizes the molecular mechanisms and triggers of EC dysregulation and current perspectives for future therapeutic strategies by autophagy targeting.