高等學校 生物 實驗實習敎材의 開發硏究 Ⅰ

崔斗文,李元求,文炯泰 공주대학교 사범대학 과학교육연구소 1984 과학교육연구 Vol.16 No.1

Teaching materials available for the effective performance of laboratory experimental work in high school biology were developed, laying emphasis on the following items : environmental pollution and natural conservations, biological concepts that the degree of difficulty is high, applications of teaching materials which are developed in foreign conturies, productions of teaching materials and models. The measuring methods of size of micrography without micrometer or with a hand-made glass micrometer were developed. By observing the morphological characters of liverwort, the methods of telling its sex, distingshing its life cycle into sexual reproduction and asexual reproduction, and comparing its life cycle with those of other plants were presented. By observing the morphological characters of moss, the methods of telling its sex and comparing its life cycle with those of liverwork, ferns and flowering plants were presented. A convenient observing method of cartilaginous and bony tissues in animals was developed using the easily available material in our surrounding The observing method of extension and contraction of chromatophores induced by environmental changes on freshwater fishes was developed. The methods of sorting and identifying the higher plants by observing their leaves and flowers were presented. The improved analytical method of plant community structure was presented by using the artificial plant community within laboratory. The assesing method of harmful effects on plant tissues by sulfur dioxide was improved.

漢江流域 豪雨의 空間特性

鄭斗永,李在炯 全北大學校 1987 論文集 Vol.29 No.-

By the spectral analysis of many heavy rains' recorded data, at Han river basin, an emprical spectral density function model is presented for the spatial distribution of storm. Using the storm data which was augmented by the Stochastic correlation with it's neighbors, the multiquadric random ndom surface of total storm depth is constructed. And to separate the local components from it's regionals and find the regional charcteristics, a double Fourier analysis was applied to the total depths. The local components, storm residuals of each storm was assumed to be an homogeneous random field and investigated with it's autocorrelation function. For the practical application, isotropic was assumed which was identifyed with emprical data. Coefficients of normalized autocorrelation for all storms were shown similar appearance. Using this emprical result, an example of the radial spectral density function is presented which represents the spatial characteristics of heavyrains over Han-river basin during 1975~1983.

업무 관련성 견갑상 포착 신경증이 의심되는 3례

정두신,성기범,신현길,안무영,김형수,홍영의 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.4

Objectives : Entrapment of the suprascapular nerve is frequently overlooked in the differential diagnosis of shoulder pain. Methods : Suprascapular entrapment neuropathy is a well-defined clinical entity and EMG and NCV is used to confirm a diagnosis. But the diagnosis typically not considered until patients develop severe weakness secondary to atrophy of the spinous musculature that the nerve supplies. Results : A narrow suprascapular notch has rarely been reported as a work-related factor of this entrapment neuropathy. Diagnosis of suprascapular entrapment neuropathy is based on the patients' clinical course, neurologic, radiologic, and electrophysiologic findings. One of the most helpful evaluations was anteriorposterior projection with the X-ray tube angled 15-30 degree caudally. The suprascapular entrapment neuropathy is relatively uncommon entity of shoulder discomfort(pain, weakness, and atrophy). Conclusions : If the worker who used his shoulder joint repetitiously having the shoulder pain and muscle weakness, we must rule out the suprascapular entrapment neuropathy. And it is needed to evaluate the motions which cause suprascapular entrapment neuropathy as the ergonomic factor.

Hydroxide diffusion rates in amorphous solid water

Du Hyeong Lee,Jaehyeock Bang,Heon Kang 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.2

Accuracy of a direct drill-guiding system with minimal tolerance of surgical instruments used for implant surgery: a prospective clinical study

Du-Hyeong Lee,Seo-Young An,Min-Ho Hong,Kyoung-Bae Jeon,Kyu-Bok Lee 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.3

PURPOSE A recently introduced direct drill-guiding implant surgery system features minimal tolerance of surgical instruments in the metal sleeve by using shank-modified drills and a sleeve-incorporated stereolithographic guide template. The purpose of this study was to evaluate the accuracy of this new guided surgery system in partially edentulous patients using geometric analyses. MATERIALS AND METHODS For the study, 21 implants were placed in 11 consecutive patients using the direct drill-guiding implant surgery system. The stereolithographic surgical guide was fabricated using cone-beam computed tomography, digital scanning, computer-aided design and computer-assisted manufacturing, and additive manufacturing processes. After surgery, the positional and angular deviations between planned and placed implants were measured at the abutment level using implant-planning software. The Kruskal-Wallis test and Mann-Whitney U test were used to compare the deviations (α=.05). RESULTS The mean horizontal deviations were 0.593 mm (SD 0.238) mesiodistally and 0.691 mm (SD 0.344) buccolingually. The mean vertical deviation was 0.925 mm (SD 0.376) occlusogingivally. The vertical deviation was significantly larger than the horizontal deviation (P=.018). The mean angular deviation was 2.024 degrees (SD 0.942) mesiodistally and 2.390 degrees (SD 1.142) buccolingually. CONCLUSION The direct drill-guiding implant surgery system demonstrates high accuracy in placing implants. Use of the drill shank as the guiding component is an effective way for reducing tolerance

Effects of different surface finishing protocols for zirconia on surface roughness and bacterial biofilm formation

Du-Hyeong Lee,Hang-Nga Mai,Phyu Pwint Thant,Su-Hyung Hong,Jaewon Kim,Seung-Mi Jeong,Keun-Woo Lee 대한치과보철학회 2019 The Journal of Advanced Prosthodontics Vol.11 No.1

PURPOSE. Surface finishing of a zirconia restoration is essential after clinical adjustment. Herein, we investigated the effects of a surface finishing protocol for monolithic zirconia on final roughness and bacterial adherence. MATERIALS AND METHODS. Forty-eight disk-shaped monolithic zirconia specimens were fabricated and divided into four groups (n = 12) based on initial surface treatment, finishing, and polishing protocols: diamond bur+polishing bur (DP group), diamond bur+stone grinding bur+polishing bur (DSP group), no diamond bur+polishing bur (NP group), and no diamond bur+stone grinding bur+polishing bur (NSP group). Initial and final surface roughness was measured with a profilometer, and shown using scanning electron microscope. Bacterial adhesion was evaluated by quantifying Streptococcus mutans in the biofilm. Kruskal–Wallis and Mann-Whitney U tests were used to compare results among groups, and two-way analysis of variance was used to evaluate the effects of grinding burs on final roughness (α=.05). RESULTS. The DP group had the highest final Ra value, followed by the DSP, NP, and NSP groups. Use of the stone grinding bur as a coarsefinishing step significantly decreased final Ra values when a diamond bur was used (P<.001). Omission of the stone grinding bur increased biofilm formation on specimen surfaces. Combining a stone grinding bur with silicone polishing burs produced the smallest final biofilm values, regardless of the use of a diamond bur in initial surface treatment. CONCLUSION. Coarse finishing of monolithic zirconia with a stone grinding bur significantly decreased final Ra values and bacterial biofilm formation when surfaces had been roughened by a diamond bur. [ J Adv Prosthodont 2019;11:41-7] PURPOSE. Surface finishing of a zirconia restoration is essential after clinical adjustment. Herein, we investigated the effects of a surface finishing protocol for monolithic zirconia on final roughness and bacterial adherence. MATERIALS AND METHODS. Forty-eight disk-shaped monolithic zirconia specimens were fabricated and divided into four groups (n = 12) based on initial surface treatment, finishing, and polishing protocols: diamond bur+polishing bur (DP group), diamond bur+stone grinding bur+polishing bur (DSP group), no diamond bur+polishing bur (NP group), and no diamond bur+stone grinding bur+polishing bur (NSP group). Initial and final surface roughness was measured with a profilometer, and shown using scanning electron microscope. Bacterial adhesion was evaluated by quantifying Streptococcus mutans in the biofilm. Kruskal–Wallis and Mann-Whitney U tests were used to compare results among groups, and two-way analysis of variance was used to evaluate the effects of grinding burs on final roughness (α=.05). RESULTS. The DP group had the highest final Ra value, followed by the DSP, NP, and NSP groups. Use of the stone grinding bur as a coarsefinishing step significantly decreased final Ra values when a diamond bur was used (P<.001). Omission of the stone grinding bur increased biofilm formation on specimen surfaces. Combining a stone grinding bur with silicone polishing burs produced the smallest final biofilm values, regardless of the use of a diamond bur in initial surface treatment. CONCLUSION. Coarse finishing of monolithic zirconia with a stone grinding bur significantly decreased final Ra values and bacterial biofilm formation when surfaces had been roughened by a diamond bur. [ J Adv Prosthodont 2019;11:41-7]

Medicinal Chemistry : A novel solid dispersion system for natural product-loaded medicine: silymarin-loaded solid dispersion with enhanced oral bioavailability and hepatoprotective activity

( Du Hyeong Hwang ),( Yong Il Kim ),( Kwan Hyung Cho ),( Bijay Kumar Poudel ),( Ju Yeon Choi ),( Dong Wuk Kim ),( Young Jun Shin ),( Ok Nam Bae ),( Abid Mehmood Yousaf ),( Chul Soon Yong ),( Jong Oh K 영남대학교 약품개발연구소 2015 영남대학교 약품개발연구소 연구업적집 Vol.25 No.-

A surface-attached silymarin-loaded solid dispersion with improved dissolution profile and enhanced oral bioavailability was formulated using silymarin, polyvinylpyrrolidone (PVP) and Tween 80 in water. In this solid dispersion, hydrophilic PVP was adhered onto the surface of crystalline drug rendering silymarin hydrophilic without changing its crystallinity. The drug solubility from the optimised solid dispersion prepared with silymarin/PVP/Tween 80 at the weight ratio of 5/2.5/2.5 increased by almost 650-fold compared to drug powder. The drug was physically and chemically stable in the solid dispersion for at least 6 months. Moreover, the solid dispersion enhanced the oral bioavailability of the drug in rats by almost 3-fold compared to the commercial product. The silymarin-loaded solid dispersion also exhibited advanced hepatoprotective bioactivity against CCl4-induced liver damage compared to silymarin or the commercial product. Thus, this silymarin-loaded solid dispersion would be useful for the enhancement of oral bioavailability and hepatoprotective activity of poorly water-soluble silymarin.

The effect of 4,4'-bis(N,Ndiethylamino) benzophenone on the degree of conversion in liquid photopolymer for dental 3D printing

Du-Hyeong Lee,Hang Nga Mai,Jin-Chul Yang,Tae-Yub Kwon 대한치과보철학회 2015 The Journal of Advanced Prosthodontics Vol.7 No.5

PURPOSE. The purpose of this preliminary study was to investigate the effects of adding 4,4'-bis(N,Ndiethylamino) benzophenone (DEABP) as a co-initiator to a binary photoinitiating system (camphorquinoneamine) to analyze on the degree of conversion (DC) of a light-cured resin for dental 3D printing. MATERIALS AND METHODS. Cylindrical specimens (N=60, n=30 per group, ø5 mm × 1 mm) were fabricated using bisphenol A glycerolate dimethacrylate (BisGMA) both with and without DEABP. The freshly mixed resins were exposed to light in a custom-made closed chamber with nine light-emitting diode lamps (wavelength: 405 nm; power: 840 mW/cm2) for polymerization at each incidence of light-irradiation at 10, 30, 60, 180, and 300 seconds, while five specimens at a time were evaluated at each given irradiation point. Fourier-transform infrared (FTIR) spectroscopy was used to measure the DC values of the resins. Two-way analysis of variance and the Duncan post hoc test were used to analyze statistically significant differences between the groups and given times (α=.05). RESULTS. In the DEABP-containing resin, the DC values were significantly higher at all points in time (P<.001), and also the initial polymerization velocity was faster than in the DEABP-free resin. CONCLUSION. The addition of DEABP significantly enhanced the DC values and, thus, could potentially become an efficient photoinitiator when combined with a camphorquinone?amine system and may be utilized as a more advanced photopolymerization system for dental 3D printing.

Interfacial distribution of hydronium and hydroxide ions in amorphous solid water

Du Hyeong LEE,Jaehyeock BANG,Heon KANG 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Z-DNA–Containing Long Terminal Repeats of Human Endogenous Retrovirus Families Provide Alternative Promoters for Human Functional Genes

Du Hyeong Lee,배우현,하홍석,박은경,이윤주,김우령,김희수 한국분자세포생물학회 2022 Molecules and cells Vol.45 No.8

Transposable elements (TEs) account for approximately 45% of the human genome. TEs have proliferated randomly and integrated into functional genes during hominoid radiation. They appear as right-handed B-DNA double helices and slightly elongated left-handed Z-DNAs. Human endogenous retrovirus (HERV) families are widely distributed in human chromosomes at a ratio of 8%. They contain a 5′-long terminal repeat (LTR)-gag-pol-env-3′-LTR structure. LTRs contain the U3 enhancer and promoter region, transcribed R region, and U5 region. LTRs can influence host gene expression by acting as regulatory elements. In this review, we describe the alternative promoters derived from LTR elements that overlap Z-DNA by comparing Z-hunt and DeepZ data for human functional genes. We also present evidence showing the regulatory activity of LTR elements containing Z-DNA in GSDML. Taken together, the regulatory activity of LTR elements with Z-DNA allows us to understand gene function in relation to various human diseases.