Conceptual Study for Tissue-Regenerative Biodegradable Magnesium Implant Integrated with Nitric Oxide-Releasing Nanofi bers

Jin‑Kyung Jeon,Hyunseon Seo,Jimin Park,Soo Ji Son,Yeong Rim Kim,Eun Shil Kim,Jong Woong Park,Woong‑Gyo Jung,Hojeong Jeon,Yu‑Chan Kim,Hyun‑Kwang Seok,Jae Ho Shin,Myoung‑Ryul Ok 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

The excessive initial corrosion rate of Mg is a critical limitation in the clinical application of biodegradable Mg implantsbecause the device loses its fi xation strength before the fractured bone heals. This study suggests a new approach to overcomethis hurdle by accelerating tissue regeneration instead of delaying the implant biodegradation. As angiogenesis is anessential process in early bone regeneration, a Mg implant coated with electrospun nanofi bers containing nitric oxide (NO),which physiologically promotes angiogenesis, is designed. The integrated device enables adjustable amounts of NO to bestored on the NO donor-conjugated nanofi ber coating, stably delivered, and released to the fractured bone tissue near theimplanted sites. An in vitro corrosion test reveals no adverse eff ect of the released NO on the corrosion behavior of the Mgimplant. Simultaneously, the optimal concentration level of NO released from the implant signifi cantly enhances tube networkformation of human umbilical vein endothelial cells without any cytotoxicity problem. This indicates that angiogenesis canbe accelerated by combining NO-releasing nanofi bers with a Mg implant. With its proven feasibility, the proposed approachcould be a novel solution for the initial stability problem of biodegradable Mg implants, leading to successful bone fi xation.

Pyriminobac-methyl과 azimsulfuron 합제의 신규제형인 분산형 정제에 대한 독성 평가

백경진,이동연,이상훈,김태원,정두순,임종환,김명석,박병권,윤효인 충남대학교 수의과대학 동물의과학연구소 2004 動物醫科學硏究誌 Vol.12 No.-

Dispersible tablets disintegrate either to form a stabilized suspension rapidly in water, or to disperse instantaneously in the rice field without the aid of water. In this study, the newly formulated dispersible tablet form of herbicidal combination, pyriminobac-methyl and azimsulfuron, was evaluated the safety for human and animals in the toxicological viewpoints. The LD_(50) value of dispersible tablet form for pyriminobac-methyl and azimsulfuron was above 2,500 mg/kg for the oral route and above 2,000 mg/kg for the dermal route. It is considered to have low acute oral and dermal toxicity based on the findings of the present studies. In addition, the combination of pyriminobac-methyl and azimsulfuron showed mild skin irritant under the conditions of this study and conjunctival redness and slight opacity on cornea appeared from 1 hour after application.

가상기준점측량을 이용한 도시기준점 분석

최석근, 안원태, 박명진 충북대학교 건설기술연구소 2008 충북대학교 건설기술연구소 논문집 Vol.27 No.1

Realtime Kinematic(RTK) method make decision to correct position by calculating correction value of rover and transmitting to rover data from GPS base station. However. this method has many problems as it required base station and rover. Also lots of time for setting, commit workers and many equipment were needed. Therefore, in this study, we made system using virtual reference station and analysed the accuracy of urban control point through VRS RTK method without limited time and distance. As result of this study, two control points were obtained with good results in expected accuracy, therefore it was good method for management of urban control point. Also, it was useful to reconstruct control point immediately and to build urban information system.

국내에서 파상풍의 연령별 면역혈청학적 역학연구

강진한,허재균,김종현,이경일,박수은,마상혁,이명숙,반상자,홍성화,조대현,이성호 대한감염학회 2001 감염 Vol.33 No.2

Background : The incidence of tetanus in adults and neonatal tetanus have been markedly reduced by world-wide use of DTP vaccines. But, tetanus is still one kind of major health problems in many developing countries, and several serosurvey stduies in developed ountries revealed that substantial proportions of adult opulation may lack immunity against tetanus and imunity level against tetanus is continuously decreasing by age. In Korea, tetanus outbreaks have been disappeared since the 1980s by high acceptant DTaP vaccination rates. Annually, few tetanus patient has been reported since 1990s. But, there knave been no seroepide-miological studies to tetanus, no trials to assess tetanuts immunizations. And we do not use Td vaccine in adults for maintaning tetanus immunity. In this aspect, we conducted age related survey of immunity to tetanus and indirectly assessed the immunogenecity of tetanus vaccines, used in Korea. Methods : For the evaluation of age related sero-survey of tetanus immunity in Korean population, study subjects were classified into 16 groups (A∼J group; below 10 years with one year interval, K∼O group; 11~60 yrs with 10 years interval, p group; over 60 yrs). The numbers of each group were 100, and sex distributions of each group were almostly equal. And far the indirect assessment of tetanus immunization in Korean children, children under 15 years old age were classified into 6 groups (I∼VI) according to the status of DTaP vaccination. The numbers of this each group were 50, and sex ratio was almostly equal. Specific IgG antibody to tetanus toxin were detected by ELISA. And the ANOVA repeated t-test was used to compare antibody levels in study groups. Results : In age related groups, the antibody levels to tetanus toxin were well maintained until 20 years old age group (L group), but thereafter the titers abruptly decreased below 0.1 IU/mL and over 75% populations among the groups over 30 years old age needed maintenance of protective immunity to tetanus. The antibody level of male was statistically higher than that of female in P group. In the groups related DTaP vaccination status, the antibody titer was very low in pre-vaccination group (I), but the titers after primary vaccinations were sharply increased and highly maintained until 15 years. Conclusion : The results of our study revealed that the immunity to tetanus was dramatically decreased in age groups over 30 years old. This result indicates that Td vaccination program in adults should be considered for maintenance of immunity to tetanus. And our study indicate that DtaP vaccination programs and vaccines, used in Korea, are effective for acquisition and maintenance of tetanus immunity in Korean children. (Korean J Infect 33:104~111, 2001)

특징형상개념을 이용한 CNC선반용 CAD/CAM시스템 개발

조진문,김석일,서명원 한국항공대학교 1995 論文集 Vol.33 No.-

Most of CAD/CAM systems for CNC lathe have been developed as the form of automatic programming systems which can generate autormatically or interactively the NC code from the process sheets and design drawings of products. But these systems have some problems during the modeling process of product shap since the shape is not described by the features intimate with system users such as chamfering, rounding, groove, arc and so on. Therfore, in this paer, the feature based CAD/CAM system for CNC lathe which is able to represent the truned product shapes by the typical features, is developed. Especially the system has the various capabilities such as the automatic determination of cutting domains, the automatic generation of CL data and NCcode, the real time cutting simulation for verification of NC code, the DNC operation and so on.

ICP-AES를 이용한 대기분진 중 중금속 분석에 대한 정도관리

임종명,이현석,이진홍 忠南大學校 環境問題硏究所 2003 環境硏究 Vol.21 No.-

In this study, factors of quality control such as laboratory environment, capability of instrument/equipment, method of analysis, calibration, and standard solution were investigated to obtain quality assurance when analyzing airborne heavy metals (e.g., Pb, Cr, Cd, Cu, Mn, Ni, Fe) using ICP-AES. A procedure of quality assurance and evaluation method of uncertainty are also suggested by applying ISO Guide. The suggested process of quality assurance will be helpful for the national monitoring network to produce better data.

기기 중성자방사화분석법을 이용한 황사특성

임종명,이현석,이진홍 忠南大學校 環境問題硏究所 2002 環境硏究 Vol.20 No.-

Using INAA, which has been thought to be one of the best analytical techniques for airborne particulate matters, this study centered on the quantitative analysis of 32 metal elements within Asian Dust aerosols. Concentrations of REEs of crustal origin, such as Ce, Cs, Dy, La, Sc, and Sm were more than 8.5 times higher in Asian Dust aerosols. In addition, major crustal elements, such as Al, Ca, Co, Fe, K, Mg, Mn, and Ti showed more than 3 times higher concentrations in those aerosols, which made PM 10 and all metal concentrations be also about 3.0 and 4.8 times higher, respectively. However, concentrations of anthropogenic origin, such as As, Br, Ci, I, In, Sb, Se, and Zn were increased to be a little higher, which means no great effect of Asian Dust on these elements.

대전 3, 4 공단지역의 대기 중 PM 2.5내 미량금속의 특성

임종명,이현석,이진홍 忠南大學校 環境問題硏究所 2003 環境硏究 Vol.21 No.-

This study centered on the quantitative analysis of about 27 trace metals including toxic ones of airborne PM 2.5 in the 3rd and 4th industrial complex area of Daejeon city, Korea. For analytical quality control, the certified reference material (NIST, the National Institute of Standards and Technology, U.S.A., SRM 2783, Air particulate on filter media) was used. The errors relative to SRM values of Sb, Mn, V, Ca, Mg, Na, K, Ti, Co, Zn, and Sm fell below 5%, while those of Cr, Fe, Ba, Th, Ce, Al, and Cu were less than 10%. From the results of the quantitative analysis using INAA, the concentxation of toxic metals such as As, Mn, Se, V, and Zn were 2.40±1.99ng/m^(3), 6.54k3.15 ng/m^(3), 1.17±0.66 ng/m^(3), 1.1150.58 ng/m^(3), 52.31±25.92 ng/m^(3), respectively. If compared in terms of enrichment factors, it was found that certain elements (e.g., In, Cu, Zn, As, C1, I, Br, Sb, and Se) are enriched in PM 2.5 samples of the study site. The results of factor analysis by SPSS shows that 70.0% of total variance is well explained.

디지탈 Walsh 시�봄�필터에 관한 연구

鄭明眞,崔甲石 明知大學校 産業技術硏究所 1984 産業技術硏究所論文集 Vol.3 No.-

This paper presents the general form of transfer matrix of the digital Walsh sequency filter using the Walsh transform and the diagonal matrix. The useful model is built according with the general form of transfer matrix. And the characteristic of the filter is considered through the simulation. The filtering characteristic which is obtained from the simulation is satisfactory. It is possible that the filter is realized by means of the software or the hardware.

액체크로마토그래피/질량분석법을 이용한 랫트 혈장내의 Surfactin C의 정량법에 관한 연구

임종환,김명석,이동연,이상훈,백경진,김태원,정두순,박병권,윤효인 충남대학교 수의과대학 동물의과학연구소 2004 動物醫科學硏究誌 Vol.12 No.-

Surfactin isolated from Bacillus subtilis has a strong surface tension-lowering activity, together with antiviral, antitumor, fibrinolytic and hypocholesterolemic activities. LC/MS is a simple, rapid and effective technique for the determination of surfactin C in rat serum. The separation of surfactin was achieved on reverse phase column. The mobile phase consisted of 0.1% trifluoracetic acid in water (A) and acetonitrile (B). As a result of analysis of blank rat serum samples, matrix interference was not shown. The values of precision and accuracy were satisfied w the guideline. A newly developed LC/MS method for the determination of surfactin C was successfully applied in its pharmacokinetic analysis.