Er:YAG laser를 조사한 치근면의 변화에 관한 연구

이상현,김영준,김병국,정현주 전남대학교 치의학연구소 2002 구강과학 Vol.14 No.4

This study was performed to evaluate the usability of Er:YAG laser for periodontal therapy. Forty dental root slabs (5x5x2mm^3) were prepared from human periodontally discased extracted teeth and grouped into 4 groups. 1)control (root planing only). 2)root planing and irradiated with laser at 30mJ. 3)root planing and irradiated with laser at 60mJ. and 4)root planing and irradiated with laser at 100mJ. The root slabs were embedded in resin block before laser treatment. Er:YAG laser was irradiated under water irrigation with the tip held perpendicular to the root surface in contact mode, After Er:YAG laser Irradiation or planing on the root surface, morphological changes have been observed under SEM, and the micro-hardness and Ca/P ratio were compared. 1. In the control group. the root surface showed the directional change caused by root planing instrumentation, and the presence of smear layer, and no exposure of dentinal tubule was observed. Laser irradiated group showed surface changes with rough dentin surface of niche and depression and dentinal tubule exposure by the elimination of smear layer. 2. The micro-hardness of root surface in the laser irradiated group was higher than the control group. The higher energy output was applied. the higher micro-hardness on root surface was resulted. 3. The higher energy output was applied, the higher Ca/P ratio was observed. The higher Ca/P ratio in 60mJ group and 100mJ group was statistically significantly compared to the control gloup and the 30mJ group These results suggest that Er:YAG laser Irradiation on the periodontally diseased root surface could remove smear layer and increase the micro-hardness on root surface and Ca/P ratio which contribute to enhance the acid resistance of periodontally treated root surface.

Er:YAG laser 조사에 의한 치은연하치석 제거효과

조인구,김영준,김병국,정현주 전남대학교 치의학연구소 2002 구강과학 Vol.14 No.3

The purpose of this in vitro study was to evaluate the efficiency of Er:YAG laser on calculus removal and the morphologic changes and hardness of the irradiated surface at different power settings. This experiment used human teeth which were extracted due to periodontal disease and had a band of calculus. Forty root slabs (5x5mm^2) were made and divided into control group and irradiated groups. Experimental groups were as follows;Control group (root planing), Group 1 (irradiated with laser at 30mj), Group 2(irradiated with laser at 60mJ). and Group 3(irradiated with laser at 100mJ). Twelve root slabs embedded in resin block were used in each group. Er:YAG laser was applied under water irrigation with the tip held perpendicular to the root surface in contact mode. The treatment time was measured until the calculus was removed completely under naked eyes. The efficiency of calculus removal was evaluated by the time for removal. Morphological changes of laser irradiated site were observed under SEM and the surface hardness was measured using a VH tester. The results were as follows; 1. The efficiency of laser scaling was increased with increasing the energy level of irradiation. (p<0.05) 2. The morphological changes such as carbonization, crater and scale-like defects in the irradiated root surface were frequently observed with increasing the energy level. 3. The surface hardness tended to increase at 60mJ and 100mJ irradiated groups than that of control group. From the results evaluting on the efficiency, morphological change, and surface hardness, lower energy level was suggested f'or the clinical application of the Er:YAG laser in scaling.

THE IMMUNOGLOBULIN LIGHT CHAIN REPERTOIRE AND STRUCTURE FOR HUMAN ANTIBODIES TO HAEMOPHILUS INFLUENZAE TYPE B POLYSACCHARIDE

Gook Hyun Chung 생화학분자생물학회 1996 생화학분자생물학회 춘계학술발표논문집 Vol.- No.-

Purification of Sulfhydryl Oxidase from Bovine Skim Milk and its Nonidentity with r-Glutamyl transpeptidase

Chung, Gook Hyun 全北大學校 1984 論文集 Vol.26 No.-

Bovine skim milk로 부터의 Sulfhydryl Oxidase (E.C. 1.8.3.2)를 전통적인 방법인 Sephadex G-100 과 DEAE-cellulose를 사용하여 부분정제하였다. 이때 이효소는 skim milk로 부터 최종단계까지 약 1800배 정제 되었으며 일반적 특성으로 pH7.2, 37℃에서 최적 조건을 나타내었으며, 효소에 대한 온도의 영향을 Arrhenius식을 이용해 13.8kcal/mole의 효소 활성화 에너지를 얻었다. 이효소의 분자량은 Sephadex G-200 Column을 통과시켜 87,000으로 추정되었으며 이 효소는 Sulfhydryl group을 그에 대응하는 disulfide로 전환시키는데 작용한다는 것을 직접적으로 확인할 수 있었다. 또한 이효소는 철이온에 작용하는 chelator에 영향을 받지 않았고 EDTA처리에 의해 완전히 불활성화 되었다. 이때 Mn^+^+에 의해 원래의 활성도를 되찾아 이효소는 Mn^+^+-dependent 효소임을 알 수 있었다. Sulfhydryl Oxidase의 기질로는 2개 이상의 이온화가 가능한 작용기를 갖는 thiol 화합물에 작용한다는 것이 밝혀졌다. 그리고 2개의 기질중 하나를 고정시키고 다른 한기질의 농도에 따라 double-reciprocal plot 했을때 고정된 기질의 변화에 따라 uncompetitive type으로 나타났으며 이효소는 disulfide에 의해 활성도가 저해되지 않아, 먼저 효소에 RSH가 들어가 disulfide로 되어 나오며 여기에 O_2가 들어가 H_2O_2로 되어 나오는 간단한 효소 기작을 제시 할 수 있었다. 한편 이러한 결과들은 Sulfhydryl Oxidase 가 r-Glutamyl transpeptidase와 명백히 구분됨을 보여 주었다.

Session G : Immunology : THE EXPRESSION OF ANTI HAEMOPHILUS TYPE B ANTIBODIES IN INDIVIDUALS EXPRESSING SPECIFIC HAPLOTYPES

Gook Hyun Chung,Kang Yeol Yu,Moon H . Nahm 생화학분자생물학회(구 한국생화학분자생물학회) 1993 추계학술대회집 Vol.- No.-

Primary Structure of the Human VkII Regions Elicited by Haemophilus influenzae Type b Polysaccharide Vaccines : The J Gene Usage Is Restricted in Child Antibodies Using the A2 Gene

Chung,Gook-Hyun,Kim,Jin-Ho,Yu,Kang-Yeol The Korea Science and Technology Center 2000 BMB Reports Vol.33 No.3

The Haemophilus influenzae type b (Hib) has been a major cause of bacterial meningitis in children who are less than two years old. The variable (V) region repertoire of adult Caucasian antibodies (Abs) to Hib polysaccharide (PS) has been characterized well. The majority of adult antibodies against Hib uses VL that is derived from the Vk gene A2 and have arginine at the N region. In order to explore the possibility those antibody responses to Hib-PS is variable in various age groups, we examined the VL regions of the antibodies to Hib-PS in Korean adults and children. We immunized Korean adults (n=8) and children(n=39) with Hib tetanus conjugated vaccines, isolated RNAs from the peripheral lymphocytes, and amplified the A2-derived VL regions by RT-PCR. The PCR products were subcloned and sequenced. Forty-seven out of 54 independent clones from children used the Jk2, or Jk3 gene in preference. The adults, however, used all of the Jk genes evenly. With respect to the amino acid sequences of variable regions, adult A2-Jk recombinants have a germline sequence. But, the 76th codon (AGC) of child A2-Jk2 recombinants was substituted with CGC(arginine) in most cases (88%) and 77 percent of child clones using the A2-Jk3 genes have isoleucine-109 at the junction of Jk-Ck instead of threonine that is found in a germline sequence. These results suggest that the mechanism of antibody production in young children is different from that of adults.

Development of plasma sources and diagnostics for the simulation of fusion edge plasmas

Woo Hyun-Jong,박인선,Kang In Je,Cho Soon-Gook,Choi Yong-Sup,Ahn Jeong-Sun,Bae Min-Keun,Chang Doo-Hee,Choi Geun-Sik,Choi Heung-Gyun,Chung Bo-Hyun,Chung Tae Hoon,Do Jeong-Joon,Goo Bon-Cheol,Hong Sunghoon,H 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.8

Although the research on divertors and scrape-off layers (SOLs) has been not as focused on as the recent success of the Korean fusion program, a few linear plasma devices have been developed for simulating divertor and SOL plasmas: (1) diversified plasma simulator (DiPS), a versatile linear machine, has been developed for simulations of divertor and space plasmas with various electric probes, such as single, triple, and Mach Probes and gridded energy analyzer. DiPS consists of two major parts: a divertor plasma simulator with a LaB 6 DC plasma source and a space plasma simulator with a helicon RF plasma source, (2) divertor plasma simulator-1 (DiPS-1) is a part of DiPS with only a LaB 6 cathode, where a low-power laser-induced fluorescence (LIF) is added and more electric probe diagnostics are augmented; it is dedicated only for fusion edge and divertor plasmas, (3) Divertor Plasma Simulator-2 (DiPS-2) has been modified from the DiPS-1 by adding a magnetic nozzle with a limiter structure and by removing the helicon source and space chamber. DiPS-2 is a linear plasma device with a 4-inch LaB 6 cathode, the same as DiPS-1, and it is focused on the development of various diagnostics, such as those used for LIF and laser Thomson scattering (LTS) along with various electric probes, on the divertor and scrape-off plasmas and on the plasma-material interaction (PMI) research, such as that of tungsten and graphite as plasma-facing components (PFCs), (4) A Multi-Purpose Plasma ( MP2 ) device is a renovation of the Hanbit mirror device [Kwon et al., Nucl. Fusion 43, 686 (2003)] with the installation of two plasma sources: LaB 6 (DC) and helicon (RF) plasma sources. A honeycomb-like large-area LaB 6 (HLA-LaB 6 ) cathode has been developed for the divertor plasma simulation to improve the resistance against the thermal shock fragility for large (8-inch) and high density plasma generation, (5) DiPS-2 has been augmented by adding another cylindrical device, called the Dust interaction with Surfaces Chamber (DiSC) for the generation and diagnostics of dusts. This combined system (DiPS-2+DiSC) has added two more diagnostics: Laser Photo-Detachment (LPD) for dust density and laser Mie Scattering (LMS) for dust size. Moreover, dusts or negative ions have been analyzed by using electric probes and capacitive diagram gauges in Transport and Removal of Dusts (TReD) device.

소의 신장으로 부터 γ - Glutamyl transpeptidase 의 정제 및 maleic acid 의 영향

정국현 ( Gook Hyun Chung ) 생화학분자생물학회 1989 BMB Reports Vol.22 No.1

Membrane bound γ-glutamyl transpeptidase was purified from bovine kidney. The procedure includes microsome separation by differential centrifugation, solublization of the enzyme from membranes using Triton X-100, aceton treatment, gel filtration on Sephacryl S-300, and adsorption chromatography on hydroxyapetite. The enzyme was purified by 396-fold and the yield was 18.6%. The enzyme was activated by its own substrate in the absence of acceptor molecule but substrate activation was disappeared in the presence of maleic acid. Though transpeptidation was inhibited in the presence of maleic acid, hydrolytic activity was increased in the presence of maleic acid. Substrate inhibition was observed according to the increase of glycylglycine concentration in the presence of maleic acid. These results suggested the possibility that maleic acid got unmask a latent active site in a large subunit of the enzyme rather than the binding of it on the acceptor binding site on small subunit of the enzyme and such a possibility was testified partially.

소의 신장내 γ-glutamyl transpeptidase의 기질결합부위에 관한 연구

정국현 全北大學校 1985 論文集 Vol.27 No.-

The inhibition pattern of bovine kidney γ-glutamyl transpeptidase by maleic acid was analysed for the inference of the nature of acceptor binding site of the enzyme. Since the inhibition of the enzyme by maleic acid occured only in the presence of acceptor molecules, it was likely that maleic acids bind on acceptor binding site. And the transpeptidation was predominant at high substrate concentration, whereas the hydrolysis was predominant at low substrate concentration. The optimum pH of the enzyme was shifted to lower pH with the concentr??tion decrease. These results imply that the exposure of certain functional groups of acceptor binding site on the enzyme is regulated according to physiological conditions. On the other hands, the suggestion that the presence of a common binding site for donor and acceptor should be reconsidered because the substrate inhibition did not occur at high concentration of glycylglycine.

A study on morphological and component change of tooth surface irradiated by Er:YAG Laser

( Sang Hyun Lee ),( Byug Gook Kim ),( Young Joon Kim ),( Hyun Ju Chung ) 대한치주과학회 2001 대한치주과학회 학술대회자료집 Vol.2001 No.1