응급의학과 전공의 교육을 위한 제언

백광제,박승희,선경,장연희,엄병선,홍윤식 대한응급의학회 1993 대한응급의학회지 Vol.4 No.2

Although the medical science in Korea has experienced remarkable development, both qualitatively and quantitatively, since its introduction at the beginning of the 20th century, its main focus has been on the expansion of spcialized treatment and medical care in general. However, the fast-paced economic development that started in the 1960's has caused substantial increases in cerbrovascular disease and coronary artery disease while the industrial development and in creased use of means of transportation have resulted in the rapid rise of incidents in external injuries. Consequently, the public has become acutelyh aware of the need for fast and effective emergency transportation and treatemnt. Such awareness also stems from the wide avalilability of medica care which is now established as a basic citizen's right as a result of the national medical insturance system that started in 1977 and was fully implemented in 1989. In response to the public demand for effetive emergency treatments, kthe health care sector has been making serious efforts to deliver better emergency treatments by expanding the emergency facilities and newly offering emergency training programs. Several hospitals have already commenced training programs in order to provide personnel specially trained in that area. The emergency medicine requires not only specialized training in the emergency treatment program in emergency should be designed in order to adapt to the specific needs of the Koreans, as based on epidemiological studies of the nature of emergency cases, its distribution in the population by ages and nature of injury, admission ratio, death rates, etc. currently prevailing in Korea. The present research has been carried out by the Korea university Hospital in preparation of the commencement of the emergency training program in 1994. The research consists of analysis of the emergency cases admitted in the Emergency center of Korea University Hospiatl from January 1992 to December 1992, its distribution, nature, and statistics regarding admission. Based on our research and our review of other available literature on the subject, we make the following suggestions regarding the specialized training program for emergency treatment. 1. The trainees must be required to be also t4rained in the areas of internal medicine surgery, obstetrics and pediatrics. 2. The training in internal medicine should include gastrointestinal, espiratory, cardiovascular medicine and nephrology which the training in surgery should include general surgery, neurosurgery and cardiac surgery. 3. The program should provide training for effective and accurate reading of the radiology. 4. The trainees should be required to participate in actural emergency treatment activities in order to have opportunities to acquire practical skills as well as theoretical knowledge. 5. The program should include course in medical management which would be necessary for effective management and administration of emergency centers and facilities. 6. The continued development of the program would require extensive studies and researches supported by the academic associations of medicine.

GT rotary file을 이용한 만곡 근관형성시 작업 효율 및 file 변형 발생에 관한 연구

신주희,백승호,배광식,임성삼,윤수한,김병현 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.5

Root canal preparation process is of utmost importance in successful treatment of root canal. Also, one of the most important purpose of the root canal preparation is to enlarge the root canal three dimensionally without changing the curvature of the root canal. However, as the curvature of the root canal increases, there are many difficulties involved in formation of optimum root canal. Therefore, in order to solve the above mentioned problems, new developments in methods of root canal preparation and equipments for such purposes were made. Recently, vigorous studies about newly introduced engine-driven nitckel-ti-tanium rotary file are conducted. As shown in research results to dates, it is well established that the use of nickel-titanium file is better suited for curved root canal than stainless steel file in maintaining the curvature of root canal and reducing the deformation of root canal. However, it is also acknowledged that there are a few discrepancies in research results according to protocol, due to failure to remove variables in experiments. In addition, although it is recommended by the manufacturer that the GT rotary file should maintain a low rotational speed of 150∼350rpm and 'light pressure' as light as not to break the lead of a pencil, academic studies about the vertical force which is not yet standardized are not sufficiently explored. Therefore, this research devised and utilized a special research equipment to standardize the appropriate range of vertical force for GT rotary file through experiments by breaking of the lead of a pencil as expressed by the manufacturer and to accurately measure factors involved through repeating and recreating the environment of root canal preparation. Forming nine experimental groups by varying the vertical forces (150g, 220g, 300g) and rpm (150rpm, 250rpm, 350rpm), the effects of changing vertical forces and rpm on working efficiency were measured in terms of time expended in root canal preparation by crown-down method using a transparent resin block with 35 degree curvature and GT rotary file (z-test). The following research using this special research equipment that involved nine experimental groups and varying the vertical force for root canal preparation from 300g which is within the normal vertical force range to 700g and 1000g which fall outside the normal rpm range. The results were as follows : 1.Analysis of the experiment results revealed that the tome spent in root canal preparation decreased as the vertical forces and rpm increased (p<0.05). Also, the effects of rpm were greater than those of the vertical forces within the normal vertical force range (β-weight test) . 2.Observation of the deformation of GT rotary file revealed that deformation increases in a direct correlation with the vertical force increase and in a reverse correlation with the rpm decrease, In the case of the vertical forces close to the normal range, the probability of GT rotary file deformation were quite different depending on the rpm changes. In the case of◎eater tier◎cal forces, the occurrences of deformation of the file were more frequent regardless of the rpm changes. 3.Deformation and breakage of file were also commonly observed in the expended time measurement experiments and GT rotary file deformation experiments in which low speed rpm (150rpm) was used and at the curved portion of the resin block. Key words : GT rotary file, Crown-down method, Working efficiency, Vertical force, Rpm, Deformation and breakage of file

레진 계열 근관봉함재 Adseal의 세포독성에 관한 연구

김희정,백승호,이우철,박한수,배광식 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.6

The properties of ideal root canal sealers include the ability of sealing the total root canal system and no toxic effects to periradicular tissues. Cytotoxicity test using cell culture is a common screening method for evaluation of the biocompatibility of root canal sealers. The purpose of this study was to investigate the cytotoxic effect of newly developed resin-based sealer (Adseal 1, 2, and 3) comparing with those commercial resin-based sealers (AH26 and AH Plus), ZOE-based sealers (Tubliseal EWT, Pulp Canal Sealer EWT) and calcium hydroxide based sealer (Sealapex). An indirect contact test of cytotoxicity by agar diffusion was performed according to the international standard ISO 10993-5. L929 fibroblast cells were incubated at 37℃ in humidified 5% CO₂-containing air atmosphere. The freshly mixed test materials were inserted into glass rings of internal diameter 5 ㎜ and height 5 ㎜ placed on the agar. After the 24 hrs incubation period, the decolorization zones around the test materials were assessed using an inverted microscope with a calibrated screen. A Decolorization Index was determined for each specimen. Adseal 1, 2, and 3 did not exert any cytotoxic effects, whereas AH26, AH Plus, Tubliseal EWT, Pulp Canal Sealer EWT, and Sealapex produced mild cytotoxicity.

새로운 PCR 클로닝 벡터의 개발

김윤일,백광희,윤재승 경희대학교 산학협력기술연구원 1996 산학협력기술연구논문집 Vol.2 No.-

PCR (Polymerase Chain Reaction) is a powerful technique for amplifying specific DNA region of interest. The PCR was used first only in the field of molecular biology, but nowadays it is widely used in the various fields such as diagnosis of genetic disorders, identification of forensic samples, and classification of organisms. However, Taq(Thermus aquaticus)DNA polymerase used in PCR has been reported to add a single nontemplate-directed A residue to the 3' ends of amplified KNA, giving rise to the difficulties in the cloning of amplified DNA. Considering the wide applications of the PCR, the development of the efficient cloning vector for PCR-amplified DNA would be very helpful for various purposes, we have designed the PCR cloning vector using the nucleotide sequence recognized by restriction endonuclease Xcm I. The double incorporation of Xcm I recognition sites in the pUC 19 and m13 DNA can make compatible ends carrying T residue and be easily ligated to PCR products.

POSTERS / PT-106 : PROMOTER ANALYSIS OF THE GTP CYCLOHYDROLASE I GENE IN Drosophila melanogaster

(Kwang Hee Baek),(Yoon Seok Ryu),(Jae Seung Yoon) 한국생화학분자생물학회 (구 한국생화학회) 1999 6th IUBMB SEOUL CONFERENCE Vol.- No.-

Transcription Termination in Eucaryote

Kwang, Hee Baek 한국유전학회 1989 Genes & Genomics Vol.11 No.4

We identified a specific DNA sequence from gastrin gene that regulates RNA polymerase II transcription termination in vivo by transferring the gastrin 3’fragment into the shuttle vector pSCAT10 at a site located immediately downstream from the CAT gene and upstream from the simian virus 40 polyadenylation region. Analysis of deletion mutant and mapping of 3’ end of gastrin RNA clearly demonstrated that this sequence is a transcriptional terminator element. The termination activity of this sequence can be shown in HeLa WCE. The termination activity is absolutely dependent on the orientation of this terminator sequence. The study of sequence specificity shows that termination sequence must be composed of only AT base pair. The study with purified RNA polymerase II.

Triple Helix Formation

Baek, Kwang-Hee 경희대학교 유전공학연구소 1989 遺傳工學論文集 Vol.1 No.-

The sequence specific recognition of double helical DNA is essential for regulation of cellular functions including transcription, replication, and cell division. Although triple stranded structures of polynucleotides were discovered decades ago, the biological function has remained unknown. Such triple helices were proposed to be involved in processes like regulation of gene expression, maintenance of folded chromosome conformations, chromosome condensation during mitosis, and induction of local conformational changes in B DNA (Morgan, 1979). Sequence specific oligonucleotide recognition of duplex DNA by forming triple helix offers powerful implications for the study of molecular biology. Oligonucleotide with efficient cleaving moiety could become useful tool in chromosome analysis. gene mapping, and isolation. Triple helix formation selectively protect the target site from restriction endonuclease and methylase, allowing specific restriction endonuclease cleavage at the triple helix target site. The fact the triple helix formation blocks the birding of specific DNA binding protein offers a new tool for analyzing protein-DNA interactions in promoter, and in some cases such oligonucleotide or their analogs might be designed to function as artificial gene specific repressor in vivo. Oligonucleotide-directed DNA binding protein can be degined to recognize specific double helical DNA sites by triple helix formation.

Overproduction of Recombinant Human VEGF (Vascular Endothelial Growth Factor) in Chinese Hamster Ovary Cells

( Seong Baek Lee ),( Jeong Soo Park ),( Seung Hee Lee ),( Jun Ho Park ),( Sung Ryul Yu ),( Hee Chan Kim ),( Dong Jun Kim ),( Tae Ho Byun ),( Kwang Hee Baek ),( Young Joon Ahn ),( Jae Seung Yoon ) 한국미생물 · 생명공학회 2008 Journal of microbiology and biotechnology Vol.18 No.1

Vascular endothelial growth factors (VEGFs) are a family of proteins that mediate angiogenesis. VEGF165 is a VEGF-A isoform and has been extensively studied owing to its potential use in therapeutic angiogenesis. This study established Chinese hamster ovary (CHO) cells overexpressing recombinant human VEGF165 (rhVEGF165) protein. The production rate of the established CHO cells was over 80 mg/l of rhVEGF165 protein from a 7-day batch culture process using a 7.5-l bioreactor with a 5-l working volume and serum-free medium. The rhVEGF165 protein was purified to homogeneity from the culture supernatant using a two-step chromatographic procedure that resulted in a 48% recovery rate. The purified rhVEGF165 protein was a glycosylated homodimeric protein with a higher molecular weight (MW) than the protein expressed from insect cells, suggesting that the glycosylation of the rhVEGF165 protein in CHO cells differed from that in insect cells. The purified rhVEGF165 protein in this study was functionally active with a half-maximal effective concentration of 3.8 ng/ml and specific activity of 2.5×105 U/mg.

Auto-segmentation of Intima/Adventitia of the Vessel by Subtracting Different types of Binarization Results

Kwang Baek Kim,Jong Hee Lee,Hyun Jun Park,Doo Heon Song 한국정보통신학회 2019 2016 INTERNATIONAL CONFERENCE Vol.11 No.1

Auto-segmentation of the vessel structure is important to detect the disorder of coronary artery. In this paper, we propose a simple strategy to extract Intima/Adventitia area effecttively by subtracting two binarization results from intravascular images. Fuzzy binarization and average binarization is used to differentiate the interior and exterior of the vessel from neighbor pixels and the difference between two result forms the vessel structure.

Magnetic grating produced by localized crystallization of amorphous Cu2MnSn thin film using femtosecond laser pulses

Baek, Kwang H.,Kim, Jung H.,Woo, Hee J.,Lee, Geon Joon,Lee, Young Pak,Yoon, Chong S. American Institute of Physics 2009 JOURNAL OF APPLIED PHYSICS - Vol.105 No.8