흙의 물리적(物理的) 성질(性質)이 다짐에 미치는 영향(影響)

김성교 ( Sung Kyo Kim ),김문기 ( Moon Ki Kim ) 한국농공학회 1976 韓國農工學會誌 : 전원과 자원 Vol.18 No.3

This study is to investigate the effect of some physical properties of soil on the compaction. The compaction effect depends upon various factors such as soil type, moisture content, gradation and compaction energy. In this study, with steady compaction energy, the relationships between maximum dry density and moisture content, gradation and consistency were analyzed by soil types. Some results obtained in this study are summarized as follows 1. Generally, the coarser the grain size, the bigger is the maximum dry density and the smaller is the optimum moisture content and its moisture-dry denisty curve is relatively steep. The finner the grain size, the smaller is the max. dry density and the bigger is the opt. moisture content and its moisture-dry density curve is less steep. 2. The relationship between max. dry density (γ_dmax) and opt. moisture content, void ratio, clay content, percent passing of No. 200 sieve, liquid limit and plastic limit can be represented by the equation γ_dmax =a₀+a₁X(a₀>0, a₁< 0) 3. The relationship between opt. moisture content (Wopt) and clay content, percent passing of No. 200 sieve, liquid limit and plastic limit can be represented by the equation Wopt=a₀+a₁X(a₀ >0, a₁>0). 4. The fact that maximum dry density of the compacted soil is decreased with the increase of the optimum moisture content in any types of soil tested, and the fact that optimum moisture content can be positively correlated with clay content, percent passing of No. 200 sieve, liquid limit and plastic limit of the soil, lead to the conclusion that clay content, percent passing of No. 200 sieve, liquid limit and plastic limit of the soil are direct factors in reduction of the maximum dry density of engineering soil.

동적하중(動的荷重)에 의한 중력식(重力式) 옹벽의 영구변위(永久變位)

김성교 ( Kim Sung Kyo ) 한국농공학회 1984 韓國農工學會誌 : 전원과 자원 Vol.26 No.1

Mononobe-Okabe에 의해서 옹벽에 대한 動的 土壓計算法이 開發된 이래 本論題中 옹벽의 滑動에 의한 變位에 대해서는 많은 硏究가 이루어졌으나 Mononobe-Okabe式이 元來 옹벽 自體의 慣性을 고려치 아니하였고 또 動的 荷重의 작용점을 제시하지 않으므로서 전도모멘트를 계산할 수 없게 하므로서 옹벽의 전도에 의한 變位에 대해서는 硏究가 되지 아니하였다. 本 硏究의 目的은 해석적 방법과 모형실험을 통해서 지진 및 폭과 등의 動的 荷重에 의한 옹벽의 전도에 의한 變位를 고찰하고자 하는 바 그 結果를 要約하면 다음과 같다. 1. 활동에 대한 항복가속도가 있는 것과 마찬가지로 전도에 대한 항복가속도가 있다. 이 항복가속도는 옹벽의 안전율이 증가함에 따라 증가한다. 2. 理論値와 實驗値는 경향으로 보아 일치한다. 실험치가 이론치보다 작은 것은 모형실험에서 옹벽측면과 컨테이너 사이의 마찰에 기인한 것으로 보아지며 마찰을 줄임으로써 더 접근시킬 수 있을 것이다. 3. 옹벽의 회전각도의 크기는 지반가속도가 클수록, 옹벽저면이 작을수록 그리고 흙의 내부마찰각의 작을수록 크게 증가한다. 4. 실용적인 규격의 옹벽의 변위는 활동에 의한 것보다 전도에 의한 것이 훨씬 크며 전체 변위의 대부분을 차지한다. 5. 옹벽 상단의 횡적 변위는 옹벽 설계를 결정짓는 중요한 요소가 될 수 있다.

BILATERAL TWO-ROOTED MANDIBULAR CUSPIDS

Sung-Kyo Kim(김성교) 대한치과의사협회 1993 대한치과의사협회지 Vol.31 No.9

EXPRESSION OF P2X₃ AND ITS COLOCALIZATION WITH TRPV1 IN THE HUMAN DENTAL PULP

김영경,김성교,Kim, Young-Kyung,Kim, Sung-Kyo The Korean Academy of Conservative Dentistry 2007 Restorative Dentistry & Endodontics Vol.32 No.6

[ $P2X_3$ ] 수용기는 세포 외에 존재하는 ATP에 의하여 활성화되는 ligand-gated cation channel로서 염증 혹은 조직 손상 시 세포에서 유리된 ATP가 $P2X_3$ 수용기와 결합하여 동통을 유발하는 것으로 알려져 있다. 이에 본 연구는 형광면역조직화학기법을 통하여 사람의 치수에서 $P2X_3$의 발현과 바닐로이드 수용기인 TRPV1과의 공존 양상을 확인함으로써 이들의 치수동통전달 기전을 밝히고자 시행되었다. 사람의 치수에서는 치관부 및 치근부 전체에 걸쳐 다수의 $P2X_3$ 면역양성 신경섬유가 관찰되었으며 이 중 약 79.4%에서 TRPV1과의 공존을 보였다. 이상의 결과로 사람의 치수에서 $P2X_3$는 TRPV1과 더불어 치수염증 시 중추로의 동통전달과 유해자극의 증폭에 있어서 중요한 역할을 할 것으로 사료된다. The purinoreceptor, $P2X_3$ is a ligand-gated cation channel activated by extracellular ATP. It has been reported that ATP can be released during inflammation and tissue damage, which in turn may activate $P2X_3$ receptors to initiate nociceptive signals. However, little is known about the contribution of $P2X_3$ to the dental pain during pulpal inflammation. Therefore, the purpose of this study was to investigate the expression of $P2X_3$ and its colocalization with TRPV1 to understand the mechanism of pain transmission through $P2X_3$ in the human dental pulp with double labeling immunofluorescence method. In the human dental pulp, intense $P2X_3$ immunoreactiyity was observed throughout the coronal and radicular pulp. Of all $P2X_3$-positive fibers examined, 79.4% coexpressed TRPV1. This result suggests that $P2X_3$ along with TRPV1 may be involved in the transmission of pain and potentiation of noxious stimuli during pulpal inflammation.

사람치아속질에 있어서 TRPV1 면역양성 신경종말의 미세구조적 특징

김영경(Young Kyung Kim),마수경(Su Kyung Ma),진명욱(Myoung-Uk Jin),김성교(Sung Kyo Kim),배용철(Yong Chul Bae) 대한해부학회 2006 Anatomy & Cell Biology Vol.39 No.4

Vanilloid receptor인 transient receptor potential VR1 (TRPV1)은 열자극에 의한 통각(thermal nociception)과 염증성 통각과민(inflammatory hyperalgesia)의 유발에 중요한 역할을 하는 것으로 알려져 있다. 이전의 우리의 연구에서 형광 면역조직화학기법을 통하여 사람의 치아속질 내에서 TRPV1의 발현과 더불어 TRPV1과 substance P (SP), calcitonin gene related peptide (CGRP)의 공존에 관하여 밝힌 바 있으며 본 연구는 그 후속 연구로서 사람치아속질에서 TRPV1 면역양성 신경섬유의 미세구조적 특징을 밝힘으로써 이들과 치아속질동통의 전달과의 상관관계를 밝히고자 하였다. 치아속질에서 TRPV1 면역양성반응을 나타내는 DAB 반응산물은 대부분 민말이집신경섬유에서 검게 침착되어 나타났으며 TRPV1 면역양성 신경섬유는 2 type으로 구분할 수 있었는데, 투명한 구형의 연접소포와 다수의 큰 치밀핵소포를 포함하는 형과 큰 치밀핵소포는 포함하지 않고 투명한 둥근소포만을 함유하는 형으로 구분할 수 있었다. 치아속질에서 TRPV1 면역양성 신경섬유는 중추신경계에서 보여지는 축삭종말의 형태가 관찰되지 않았으며 축삭의 특정부위의 팽창 없이, 선형태의 축삭 내에 다수의 소포가 밀집된 양상을 보였다. 소포가 밀집되어 있는 부위에서 인접부위와의 연접형태는 관찰되지 않았다. 지금까지의 많은 면역조직화학적 실험에서 일차들신경섬유종말 내의 치밀핵소포에는 SP, CGRP와 같은 신경펩타이드들이 함유되어 있으며 투명한 구형의 연접소포에는 glutamate와 같은 흥분성 신경전달물질이 함유되어 있는 것으로 보고되고 있다. 이상의 결과들을 종합해 보면 치아속질에서 TRPV1 면역양성 신경섬유는 뚜렷이 구분되는 2 type의 미세구조적 특징을 가지고 있으며 이들은 각각 염증성 통각과민과 열자극에 의한 통각의 전달에 관여하는 것으로 생각된다. The vanilloid receptor TRPV1 has been suggested to play an important role in thermal nociception and inflammatory hyperalgesia. In our previous study, we examined the expression of TRPV1 and colocalization of TRPV1 with substance P (SP) and calcitonin gene related peptide (CGRP) through fluorescence immunocytochemistry. Here, we investigated ultrastructural characteristics of TRPV1 immunoreactive fibers in the human tooth pulp through preembedding immunocytochemistry. TRPV1 immunoreactivity was present in the unmyelinated nerve fibers in the tooth pulp. There were two types of TRPV1 IR nerve fibers identified in the human tooth pulp: one containing clear round vesicles and many dense-cored vesicles, the other containing clear round vesicles and few dense-cored vesicles. TRPV1 immunoreactive fibers were constant in diameter without swellings along the length. Boutons en passant and boutons terminaux usually observed in the CNS were not observed in the TRPV1 immunoreactive fibers. Many vesicles were accumulated in the TRPV1 immunoreactive fibers, however synaptic structure was not found. It is known that dense-cored vesicles contain neuropeptides such as SP and CGRP and clear round vesicles contain neurotransmitter such as glutamate. Taken together, our results suggest that TRPV1 immunoreactive fibers showing distinct ultrastructructural features may be involved in inflammatory hyperalgesia and thermal nociception in the tooth pulp.

제 2형 당뇨 환자의 근관 감염에서 나타난 병원균과 그 항생제 감수성

조주연(Ju-Yeon Cho),김성교(Sung-Kyo Kim) 대한치과의사협회 2016 대한치과의사협회지 Vol.54 No.5

Aim: The purpose of this study was to identify dominant pathogens and their antimicrobial susceptibilities of endodontic infection in type II diabetes mellitus (DM) patients to determine effective empirical antibiotics. Methodology: Pathogens from endodontic infection in six patients with DM and in six patients without DM were cultured, identified and their antimicrobial susceptibility was tested using Vitek2 systems (bioMérieux, Marcy l’ Etoile, France). The results were analyzed using Chi-square test and Fisher’s exact test at P< 0.05 level. Results: Pathogens of opportunistic infection were dominant in DM patients (P=0.015). However, there was no significant difference of antimicrobial susceptibility between DM and non-DM patients. Relatively high percent (27%) of pathogens showed resistance to penicillin. Conclusions: More cautions should be paid to DM patients because they are prone to opportunistic infection. Penicillin is not effective in the control of endodontic infection.

Antimicrobial choice of severe endodontic infection

Ju-Yeon Cho(조주연),Jung-Hong Ha(하정홍),Myoung-Uk Jin(진명욱),Young-Kyung Kim(김영경),Sung-Kyo Kim(김성교) 대한치과의사협회 2014 대한치과의사협회지 Vol.52 No.7

Objectives : The purpose of our study was to evaluate penicillin as a still drug of choice for severe endodontic infection, by analyzing the antimicrobial susceptibilities from endodontic infections with swelling to figure out appropriate antibiotics as empirical treatment. Materials and methods : This study involved 18 patients who attended for emergency treatment because of facial or periapical swelling associated with root canal infections. Identification and antimicrobial susceptibility test of each pathogen were performed by Vitek2 Systems (bioMerieux, Marcy l’Etoile, France). Results : The most frequent bacteria was Streptococcus spp.(77%), and the resistance against penicillin was 35% in overall patients, followed by clindamycin and erythromycin (17%), which was much higher than previous studies. Conclusions : In our study, the higher resistance made penicillin alone not to be chosen as the first antibiotic drug for severe endodontic infections. Combinations with other drug, penicillin with wider spectrum of activity, or changing to other antibiotics was considered while remembering the increased risk of resistant microorganism.

Benzalkonium Chloride가 BPDM/HEMA계 접착제의 상아질 접착에 미치는 영향

김성교,안식환,권병균 大韓齒科保存學會 1996 Restorative Dentistry & Endodontics Vol.21 No.2

NITRIC OXIDE와 치수

김영경,김성교 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.5

Nitric oxide (NO) is a small molecule (mol. wt. 30 Da) and oxidative free radical. It is uncharged and can therefore diffuse freely within and between cells across membrane. Such characteristics make it a biologically important messenger in physiologic processes such as neurotransmisson and the control of vascular tone. NO is also highly toxic and is known to acts as a mediator of cytotoxicity during host defense. NO is synthesized by nitric oxide synthase (NOS) through L-arginine/nitric oxide pathway which is a dioxygenation process. NO synthesis involves several participants, three co-substrates. five electrons, five co-factors and two prosthetic groups. Under normal condition, low levels of NO are synthesized by type Ⅰ and Ⅱ NOS for a short period of time and mediates many physiologic processes. Under condition of oxidant stress, high levels of NO are synthesized by type Ⅱ NOS and inhibits a variety of metabolic processes and can also cause direct damage to DNA. Such interaction result in cytostasis, energy depletion and ultimately cell death. NO has the potential to interact with a variety of intercellular targets producing diverse array of metabolic effects. It is known that NO is involved in hemodynamic regulation, neurogenic inflammation. re-innervation, management of dentin hypersensitivity on teeth. Under basal condition of pulpal blood flow, NO provides constant vasodilator tone acting against sympathetic vasoconstriction. Substance P, a well known vasodilator, was reported to be mediated partly by NO, while calcitonin-gene related peptide had provided no evidence of its relation with NO. This review describes the roles of NO in dental pulp in addition to the known general roles of it.

도말층이 가온 수직가압 근관 충전후 치근단 누출에 미치는 영향

김성교,권태경 大韓齒科保存學會 1998 Restorative Dentistry & Endodontics Vol.23 No.2