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Glass Ionomer시멘트에 의한 상아질구조변화에 관한 주사전자현미경적 연구
박성규,우이형,최대균,최부병,박남수,Park, S.K.,Woo, Y.H.,Choi, D.K.,Choi, B.B.,Park, N.S. 대한치과보철학회 1987 대한치과보철학회지 Vol.25 No.1
This study was designed to investigate the pulpal effects of the glass ionomer cement. (Lining cement, G-C Co. Japan) For this purpose, 10 cats were selected, and Class V cavities were prepared on canines of the cats. One experimental group was filled with glass ionomer cement and the other group was filled with zinc phosphate cement . (G-C Co, Japan) The animals of the experimental and control group were sacrificed at 1,2,3,4,6, weeks after the experiment. For comparison of reparative dentin formation pattern in direction of the pulpal and fractured lateral surface, each of them was observed with scanning electron microscope. The findings led to the following conclusions; 1. Reparative dentin of the glass ionomer cement and zinc phosphate cement filling groups were formed on the internal surface of dentin as the shape of hemispherical and spherical with a rough surface. 2. Some of reparative dentin of the glass ionomer cement filling group was started to form at 1 week after experiment, and at 6 weeks after experiment, it had been increased gradually in number and size. 3. Reparative dentin of zinc phosphate cement filling group was formed vigorously, however, gradually was decreased in number and size, and disappeared at 6 weeks after experiment. 4. During the formation of reparative dentin, peritubular dentins were indistinguishable. 5. The diameter of dentinal tubules of reparative dentin has been decreased, during the reparative dentin formed, and it became very irregularly at 6 weeks after experiment.
전이금속의 Carbene 착물에 대한 이론적 연구 (반응성, 전자구조, Diels-Alder 반응)
박성규,김일두,김준태,김성현,최창진,전용구,Park Seong-Kyu,Kim IIl-Doo,Kim Joon Tae,Kim Sung-Hyun,Choi Chang-Jin,Cheun Young Gu 대한화학회 1992 대한화학회지 Vol.36 No.1
크롬이움, 몰리브덴늄, 텅그스텐의 carbene 착물인 $(CO)_5Cr=CCHCH_2(XCH_3)\;,\;(CO)_5Mo=CCHCH_2(XCH_3)\;,\;(CO)_5W=CCHCH_2(XCH_3)$에 대해서 확장된 Huckel 방법으로 계산하여 이들의 전자구조와 반응성 등을 고찰하였다. fragment들의 궤도함수 상관도로부터 M=Ccarb 이중결합의 특성을 알 수 있다. M=Ccarb 이중결합의 ${\sigma}$결합은 carbene의 HOMO로부터 $(CO)_5M$의 LUMO로 전자가 이동하므로 형성되고 ${\pi}$결합은 전이금속의 축퇴된 d${\pi}$ 궤도함수로부터 carbene의 LUMO로 전자가 역이동하므로서 형성된다. M=Ccarb 결합에서 전하분극은 Mo, W-착물에 대해서 M쪽이 더욱 양으로 계산되었다. 화학적 또는 물리적 성질은 carbene 탄소원자의 양전하에 의하여 결정되며 carbene 탄소원자의 친전자적 반응성은 전하에 의해서가 아니라 frontier orbital의 LUMO에 의해서 지배받는다. Electronic structures and reactivities of the chromium, molybdenum, and tungsten carbene complexes, $(CO)_5Cr=CCHCH_2(XCH_3)\;,\;(CO)_5Mo=CCHCH_2(XCH_3)\;, and\;(CO)_5W=CCHCH_2(XCH_3)$, are studied by means of Extended Huckel calculations. The origin of the M=Ccarbene double bond is clarified from the diagram of the orbital correlation with the fragment orbitals. The ${\sigma}$ bond of the M=Ccarbene double bond is formed by the electron transfer interaction from the HOMO of the carbene to the LUMO of the $(CO)_5M$. The ${\pi}$ bond is formed through the back-transfer of electrons from one of the degenerated d${\pi}$ orbitals to the LUMO of the carbene. The polarization of charge of the M=Ccarbene bond is calculated to be M=Ccarbene for Mo, and W carbenes. The chemical and physical properties of these complexes are resulted from an appreciable positive charge on the carbene carbon. The electrophilic reactivity of the carbene carbon is not charge controlled, but is controlled by the frontier orbital, LUMO.
박성규,박정환,허선아,조성동,조병욱,전용구,Park Seong-Kyu,Park Jeong-Hwan,Heo Seon-Ah,Cho Sung-Dong,Jo Byung-Wook,Cheun Young-Gu 대한화학회 1993 대한화학회지 Vol.37 No.6
에너지 치환기를 갖는 옥세탄 유도체(AMMO, BAMO, NMMO, BNMO)를 합성하였으며, 이들의 수율을 높이고 대량생산을 하기 위하여 조건을 최적화하였다. Oxetane derivatives (AMMO, BAMO, NMMO, BNMO) having energetic substituents were synthesized and characterized in order to improve the production yield and practical scale-up.