Dislocation Density-Based Constitutive Model and Processing Map for T2 Copper During Isothermal and Time-Variant Deformation

Gang Chen,Yu Jin,Jing Wang,Cheng Zhang,Qiang Chen,Hongming Zhang,Xingjian Zhao,Zhiyong Li,Changhai Xie,Zhiming Du 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

Isothermal compression tests were carried out to study the hot deformation behavior of T2 copper under various conditions. The deformation parameters, such as temperature and strain rate, have strong influence on flow stress and microstructureevolution of the alloy. A unified dislocation density-based model considering dynamic recovery and recrystallization wasestablished. And material parameters of the developed model were optimized by genetic algorithm. Comparisons betweenthe experimental and model data demonstrates that the developed model can precisely describe the flow behavior at quitewide range of deformation conditions. Meanwhile, the designed iterative procedure allows the model to be applied in timevariantdeformation conditions. Processing map and microstructure examination were constructed to optimize the processingwindow of the studied alloy. According to the processing maps, flow instability mainly appeared at low temperatures of500–650 °C and strain rates higher than 0.1 s−1. The optimum deformation parameters of T2 copper was concluded as thetemperature range of 700–800 °C and the strain rate of 0.1–1 s−1.

酒酊依存 患者에서 末梢神經炎의 電氣生理學的 硏究

田珍淑,韓昊成 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.4

알코올성 신경염은 주정의존 환자의 약 34%에서 발생한다고 알려졌으며, 그 원인으로서는 알코올의 직접적인 독작용, 비타민 결핍, 영양결핍 등이 제시되고 있다. 저자들은 임상증상이 없이 검사상 나타나는 신경염의 이환이 어느 정도이며, 병인의 가능성이 높은 요인은 무엇인지 알아보고자 본 연구를 시행하였다. 주정의존으로 입원한 환자(N=47)에서 상지와 하지의 운동신경과 감각신경 및 근육에 대해 신경전도검사(이하 NCV) 및 근전도검사(이하 EMG)를 시행하고, 정상 대조군(N=17)에 대한 검사 결과와 비교하였으며, 여러 변인과의 상관성을 검토하였다. 1) 주정의존 환자 47명중 알코올성신경염의 임상증상을 지닌 환자는 8명(17.0%)이었으며, 신경전도검사 및 근전도검사상 34명(72.3%)에서 신경염의 소견을 보였다. 2) 주정의존 환자의 운동신경에 대한 NCV검사에서 대조군보다 환자군의 비골(peroneal) 신경의 진폭이 유의하게 감소되었고(p<0.01), 전도속도는 정중(median)신경(p<0.005) 과 척골 및 비골신경(각각 p<0.05)에서 유의하게 감소되었으며, 원위잠복기는 대조군과 유의한 차이가 없었다. 3) 주정의존 환자의 감각신경에 대한 NCV검사에서 진폭은 척골신경(p<0.0005)과 비복(sural) 신경(p<0.05)에서 유의하게 감소되었고, 전도속도는 정중신경(p<0.05)에서 유의하게 감소되었으며, 원위잠복기는 척골신경(p<0.005)에서 유의하게 지연되었다. 4) H-반사는 환자군에서 측정한 42명중 30명(71.4%)에서 이상소견(무반응)을 보였다. 5) 근전도검사상 47명중 15명(31.9%)에서 이상소견(휴식시 fibrillation potentials 및 / 또는 positive sharp waves, 작동시 motor unit action potential 수의 감소 및 하지근의 작동에 대한 polyphasic potential 증가)을 보였다. 6) 연령, 음주기간, 주정의존의 정도, 우울증의 심도, 인지기능장애, 간기능, 빈혈 및 혈중 folic acid치, 지질대사 등은 알코올성신경염과 유의한 상관관계가 없었다. 이상의 결과는 임상증상은 없으나 전기생리학적 검사상 발견되는 준임상적 알코올성신경염의 빈도가 예상 외로 높으며, 전기생리학적 검사소견은 축삭변성(axonal degeneration)의 가능성을 높이 시사하고 있어서 그 원인으로서 알코올의 직접적인 신경독작용을 고려해 볼 수 있다. The alcoholic neuropathies developed in approximately 34% of chronic alcoholics. Direct neurotoxic effect of alcohol, vitamin deficiencies and nutritional deficiencies were suggested to be the major causes of alcoholic neuropathies. The aims of this study were to identify the prevalence of subclinical peripheral neuropathies in alcohol dependence, and to speculate on the underlying mechanism of alcoholic neuropathies. The nerve conduction velocity(NCV) and electromyography(EMG) were tested for the male alcoholics(N=47) and normal controls(N=17), and the variables which might after the test result of NCV and EMG were discussed. 1) While 8(17.0%) out of 47 alcoholics clinically had neuropathies, the NCV and EMG detected signs of peripheral neuropathies in 34(72.3%) alcoholics. 2) On the motor NCV in alcoholics, the amplitude of peroneal nerve was significantly lowered(p<0.01). The conduction velocities were significantly reduced in the median(p<0.005), ulnar and peroneal(p<0.05 respectively) nerves. There was no significant differences in the distal latency comparing with control group. 3) On the sensory NCV in alcoholics, the amplitude was significantly lowered in ulnar(p<0.0005) and sural(p<0.05) nerves. The conduction velocities were significantly reduced in median nerve(p<0.05). The distal latencies were significantly delayed in ulnar nerve(p<0.005). 4) The H-reflex was absent in 30 alcoholics(71.4%) among 42 alcoholics. 5) On the EMG, such abnormal findings as the fibrillation potentials and/or positive sharp waves in rest, and the decreased numbers of motor unit action potentials and increased polyphasic potentials in volition of limb muscles were found in 15(31.9%) out of 47 alcoholics. 6) The alcoholic neuropathies were not correlated with variables like age, duration of alcohol drinking, severity of alcohol dependence, cognitive deficit, hepatic dysfunction, anemia and serum folic acid and lipid metabolism. In conclusion, the prevalence of subclinical neuropathies in alcoholics seemed to be much higher beyond expectation. The electrophysiological studies highly suggested that the cause of neuropathies was the direct neurotoxic effect of alcohol that might exert axonal degeneration.

고속액체크로마토그래피에 의한 나프록센 광학이성질체의 분리 및 품질관리

정수진,진전성,이은주,이은실,강종성 忠南大學校 生命科學硏究院 醫藥品開發硏究所 2006 藥學論文集 Vol.21 No.-

Enantiomeric separation of naproxen is necessary in drug evaluation processes as the pharmacological activity of naproxen resides mainly in the (S)-enantiomer, The enantioseparation of naproxen was carried out with three different stationary phases. The methods were validated with the terms of linearity, intraday and interday precision, accuracy, selectivity and recovery. Among the selected stationary phases, ChiroSil DMB column with hexane : t-butylmethylether : acetic acid (60:40:0.1, v/v/v) as mobile phase showed the best enantioseparation of the naproxen in the commercial preparations. The wavelength for detection was 270 nm and flow rate was 2.0 mL/min. The contents of (S)-naproxen in the commercial preparations were 92.7 - 98.3%, indicating that all tested preparations were satisfactory to current regulation. However, the contents of (R)-naproxen as impurity in the commercial preparations were varied from 0.08% to 1.08%.

高敞地域 農業用水源의 水質特性에 關한 硏究

金煥起,姜鎭錫,全鍾南 全北大學校 附設 都市및環境硏究所 1992 都市 및 環境硏究 Vol.7 No.-

This paper had study on the water quality characteristics and water quality management of water sources as agricultural water in Gochang. This study included the measurement of stream water quality, water quality of reservoir and water quality of groundwater, this investigation was tried to find out water quality standard of agricultural water into each sources. Results from water quality analysis, the water quality of stream in Gochang was measure that pH was 8.5-7.0, COD was 14.8-1.6㎎/ℓ, SS was 282.8-1.2㎎/ℓ, T-P was 2.64-0.17㎎/ℓ, T-P was 0.22-0.01㎎/ℓ, electric conductivity was 220-50㎲/㎝ and Cd, Pb, Cu was below 0.01㎎/ℓ. The water quality of reservoir in Gochang was measure that pH was 7.0-8.0, COD was 8.0-2.6㎎/ℓ, SS was 126.1-3.4㎎/ℓ, T-P was 1.13-0.456㎎/ℓ, T-P was 0.16-0.05㎎/ℓ, electric conductivity was 200-130㎲/㎝. The water quality of ground water in Gochang was measure that pH was 6.0-8.4, TS was 51.8-419.8㎎/ℓ, COD was 2.4-1.0㎎/ℓ, CO_3^- was 125.8-14.5㎎/ℓ, SO_4 was 0.46-48.3㎎/ℓ, Cl^- was 134.1-3.6㎎/ℓ, T-N was high 15㎎/ℓ Therefore, stream water and reservoir water in Gochang had adequate to agricultural water quality standard. The ground water had adequate to agricultural water quality standard in deep well and low well.

부산시 일개구 지역주민의 위암선별검사 수검 및 반복수검 실태 및 관련요인조사

정인숙,배은숙,천동환,전진호,이화자,박남희 韓國保健敎育.健康增進學會 2003 보건교육건강증진학회지 Vol.20 No.1

The importance of repeat screening for stomach cancer is well known to decrease deaths from stomach cancer. This study was aimed at assessing practice behaviors and to identify related factors in the aspects of demographic factors, health status and cancer risk recognition, attitude to cancer screening, health behaviors, and inhibiting or facilitating factors to stomach cancer screening in an urban area. Data was collected through self-administered questionnaires from 403 people aged 40 to 69 years from April 23th to May 15th, 2002. Practice behaviors were classified as :"ver"r "ver"and "peat"r "t repeat"rouped based on a recent 5 year screening history. The results were as follows: 1. Among the 403 subjects: "e ever group"as 23.8% and "e repeat group"as 4.0%. The rates of screening were 20.5% for men, 27.8% for those women, and 27.3% for aged 40-49, 24.5% for those aged 50-59, 19.0% for those aged 60-69. The rates of repeat screening were 4.0% for men, 4.1% for women, and 2.9% for those aged 40-49, 6.3% for aged 50-59, 2.5% for those aged 60-69. 2. The main factors associated with adherence to gastric cancer screening were education(post high school vs below : OR=2.44), previous cancer screening(yes vs no : OR=2.61), belief in personal health(no vs yes : OR=2.72), health status(unhealthy vs healthy : OR=3.40), possibility of cancer compared to others(low vs not low : OR=2.56), and regular exercise(yes vs no : OR=2.94). The main factor associated with adherence to gastric cancer repeat screening was other cancer screening (yes vs no : OR=6.33). Consequently, there is a need to change the recognition of the importance and necessity of stomach cancer screening in healthy conditions through health education, and to perform multiple screening tests each visit.

Biodegradable cross-linked poly(L-lactide-co-e-caprolactone) networks for ureteral stent formed by gamma irradiation under vacuum

Xiliang Liu,Song Liu,Youkun Fan,Jin Qi,Xin Wang,Wei Bai,Dongliang Chen,Chengdong Xiong,Lifang Zhang 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

The poly(L-lactide-co-e-caprolactone) (PLCL) ureteral stent creeps and loses shape stability, increasingthe risk of stent tube dislocation. The rubbery biodegradable cross-linked PLCL networks were preparedthrough gamma irradiation under vacuum in the presence of trimethylolpropane triacrylate (TMPTA),pentaerythritol tetraacrylate (PET4A), and pentaerythritol triacrylate (PETA). At a standard sterilizationdose of 25 kGy, the gel content and network density of PLCL networks increased with increasingcrosslinking agent content (1, 3, 5, 7 wt%), and crosslinking efficiency decreased in the order ofPETA > PET4A > TMPTA. The average molecular weight (Mc ) between two crosslinks ranged from 2000to 105 g/mol. To perform the beneficial semi-interpenetrated polymer network and characterized bythe principle, the networks were processed in several doses (25, 50, 75, 100, and 125 kGy). In place ofthe Charlesby-Pinner equation, the irradiation cross-linking followed the Chen-Liu-Tang equation. ThePLCL network with 7 wt% PETA had a gel fraction of 83%, tensile strength of 34.7 MPa, and tensile setvalue as low as 5%. Furthermore, degradation in vitro was slowed down. Thus, PLCL networks with appropriateelasticity and flexibility, inherent biodegradability, and excellent biocompatibility can provide apromising alternative method for soft tissue repair engineering, such as ureteral stents.

자돈에 있어 게르마늄 용질액의 급여가 성장 및 혈액학적 변화에 미치는 영향

홍종욱,권오석,민병준,조진호,진영걸,손경승,강종옥,김인호 한국국제농업개발학회 2004 韓國國際農業開發學會誌 Vol.16 No.4

본 연구의 목적은 이산화게르마늄을 함유한 게르마늄 용질액을 자돈에 급여하였을 때 성장 및 혈액학적 변화에 미치는 영향을 조사하기 위하여 실시하였다. 3원 교잡종 자돈 60두 (평균체중 11.22±0.10㎏)를 공시하였다. 시험설계는 옥수수-대두박 위주의 대조구(CON)와, 대조구 사료내 게르마늄 용질액을 0.5 ppm 첨가한 구(GC0.5) 및 대조구 사료내 게르마늄 용질액을 1.0 ppm 첨가한 구(GC1.0)로 3개 처리를 하였다. 0-10일간 사양시험기간동안, 일당증체량에 있어서 GC0.5 처리구가 약간 높게 평가되었다(quadratic effect, P<0.02). 그러나 전체 시험기간동안, 일당증체량, 일당사료섭취량 및 사료효율에 있어서 처리구간에 유의적인 차이는 보이지 않았다. 영양소 소화율에 있어서는 GC0.5 처리구가 조회분(linear effect, P<0.01; quadratic effect, P<0.04), 칼슘(linear effect, P<0.01; quadratic effect, P<0.01), 인 (linear effect, P<0.02; quadratic effect, P<0.04) 소화율이 유의적으로 높게 평가되었다. 혈액내 neutrophil 농도에 있어서는 게르마늄 용질액의 첨가 수준이 증가함에 따라 유의적으로 증가하는 경향을 나타내었다(quadratic effect, P<0.02). 결론적으로, 자돈 사료내 게르마늄 용질액의 급여가 성장 및 혈액학적 수치에는 영향을 미치지 못하는 것으로 사료된다. This study was conducted to investigate the effects of dietary germanium colloid on the growth performance and hematological values in nursery pigs. Sixty pigs (11.22(0.10 ㎏ average initial body weight) were used in a 20 d growth assay. Dietary treatments included 1) CON (basal diet), 2) GC0.5 (basal diet+0.5 ppm germanium colloid) and 3) GC1.0 (basal diet+1.0 ppm germanium colloid). For d 0 to 10, pigs fed GC0.5 diet grew faster than pigs fed CON and GC1.0 diets (Quadratic effect, P<0.02). However, through the entire experimental period, no statistical differences were found for aver-age daily gain, average daily feed intake and gain/feed. Apparent digestibilities of crude ash (Linear effect, P<0.01; Quadratic effect, P<0.04), calcium (Linear effect, P<0.01; Quadratic effect, P<0.01) and phosphorus (Linear effect, P<0.02; Quadratic effect, P<0.04) in pigs fed GC0.5 diet were greater than for pigs fed CON and GC1.0. Neutrophil concentration in blood increased as the concentration of germanium colloid in the diets was increased with significant difference (Quadratic effect, P<0.02). In conclusion, growth performance and hematological values were not influenced by dietary germanium colloid.

Aeromonas hydrophila cytosolic 5’-methylthioadenosine/S-adenosylhomocysteine nucleosidase MtaN-2

Jinli Chen,Fei Shang,Lulu Wang,Wei Liu,Yuanyuan Chen,Jing Lan,Liming Jin,Nam-Chul Ha,Chunshan Quan,Yongbin Xu 한국구조생물학회 2018 Biodesign Vol.6 No.3

5’-methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) plays a critical role in diverse pathways in bacterial cells such as biological methylation, polyamine biosynthesis, methionine recycling, and bacterial quorum sensing. It has been known that MtaN catalyzes the hydrolysis of N-ribosidic bond of adenosine-based substrates such as S-adenosyl-L-homocysteine (SAH), S-methyl-5’-thioadenosine (MTA) and 5’-deoxyadenosine (5’-DOA). In Aeromonas hydrophila, there are two MtnN subfamily proteins: MtaN-1, a periplasmic protein with an N-terminal signal peptide; and MtaN-2, a cytosolic protein. In this study, MtaN-2 from A. hydrophila was successfully expressed and purified using Ni-NTA affinity, Q anion-exchange, and gel-filtration chromatography. We first crystallized apo MtaN-2 but it diffracted to a low resolution of 5.1 Å. New crystals suitable for diffraction were obtained by adding 2 mM adenosine, a substrate analog of MtaN-2 during purification process and the crystals diffracted to the resolution of 2.0 Å. The crystals belong to the trigonal space group P31 or P32, with unit-cell parameters of a = b = 74.94 Å and c = 185.21 Å. The asymmetric unit contains four complexes of MtaN-2 with hydrolysis products of adenosine.

Associations of night shift status during pregnancy with birth outcomes

Se Jin Lee(Se Jin Lee),Chorong Kim(Chorong Kim),Eun Ju Lee(Eun Ju Lee),Myoung-Nam Lim(Myoung-Nam Lim),Jeeyoung Kim(Jeeyoung Kim),Sunghun Na(Sunghun Na),Woo Jin Kim(Woo Jin Kim),Ko-CHENS study group(Ko 한국환경보건학회 2022 한국환경보건학회 학술대회 자료집 Vol.2022 No.5

한·중간 지역격차 비교 연구

Ling Chen(Ling Chen),김주진(Ju-Jin Kim),신우진(Woo-Jin Shin) 한국비교정부학회 2023 한국비교정부학보 Vol.27 No.1

(Purpose) Although the existence of regional disparities among local governments is inevitable, it needs to be reduced in order to improve the efficiency of resource allocation and create equity in the policy environment. As a starting point for narrowing the regional disparity in Korea and in China, this paper attempts to find out the variations and fundamental causes of the regional disparity from 1985 to 2019 in terms of GRDP. (Design/methodology/approach) For this, the characteristics of regional disparities are investigated by computing the Gini coefficients for the GRDP and per capita GRDP of local governments in both countries, and the Gini coefficient decomposition method is used to explain the major causes of regional imbalances. (Findings) The results derived from analyzing the major factors of economic disparity with the Gini coefficient, the contribution of the economic disparity between and within metropolitan areas is similar to the factors of the overall economic disparity in Korea. On the other hand, it can be seen in China that local government factors at the regional level are greater since the contribution of the disparity between regions is greater than within a region. (Research implications or Originality) Therefore, for Korea both policy efforts of local governments and a balanced regional development policy at the central government level are required to reduce the disparities. On the other hand, for China it is believed that policies to improve regional disparities are needed at the regional government level because the contribution of disparities between regions is greater than within a region.