On the Strengthening Effects Affecting Tensile and Low Cycle Fatigue Properties of Low-Alloyed Seismic/Fire-Resistant Structural Steels

Jung‑Ho Sim,Tae‑Yeong Kim,Jun‑Yeon Kim,Chi‑Won Kim,Jun‑Ho Chung,Joonoh Moon,Chang‑Hoon Lee,Hyun‑Uk Hong 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

In the present study, low carbon ferritic and bainitic steels with different contents of Mo, Ti, and Nb were designed for bothseismic and fire-resistant applications. The microstructure of steels containing 0.3 wt% Mo–0.02 wt% Nb (‘A’ hereinafter)was mainly composed of bainite. By contrast, the microstructure of steels with 0.2 wt% Mo–0.13 wt% Ti (‘B’ hereinafter)consisted of ferrite with a high density of nano-sized (Ti,Mo)-rich MX precipitates. The results showed that the bainiticmicrostructure (‘A’ steel) was quite favorable to high-temperature strength and thermal stability. The yield strength of ‘A’ steelat both room and 600 °C temperatures increased consistently with increasing thermal exposure time (600 °C/200–1000 h),since the precipitation of NbC particles occurred while maintaining bainitic ferrite platelets with a high density of dislocationsduring exposure. In the ‘B’ steel, the formation of nano-sized (Ti,Mo)-rich MX particles was effective to impededislocation movement, leading to excellent plasticity (lower yield ratio) at room temperature. However, their contributionto precipitation hardening was not so much at 600 °C, as compared to the bainitic strengthening. During low cycle fatiguetests at room temperature, the main different feature between the two steels is that the ‘A’ steel showed cyclic softeningwhile cyclic hardening was evident in the ‘B’ steel. The bainitic microstructure showed a better fatigue life due to increasedductility manifested by cyclic softening, by which dislocation cell was developed.

정신분열병과 Glutathione S-Transferase M1유전자 다형성

배치운,조자현,김연주,김태석,김정진,이창욱,이수정,전태연,이철,백인호 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.5

Objectives : This study aimed to test the possible association between Glutathione S-Transferase Ml gene (GSTMl) variants and schizophrenia. Methods : One hundred and eleven inpatients with schizophrenia and 130 healthy controls were recruited. Genotyping was performed by polymerase chain reaction-based method. Results : The GSTMl null genotype was significantly more frequent in patients with schizophrenia than in controls (p=0.014, odd ratio=1.93, 95% confidence interva1=1.115-3.351), while GSTMl genotype vahants were not associated with either tardive dyskinesia (TD) or total Abnormal Involuntary Movement Scale (AIMS) scores. Conclusion : The present study suggests that the GSTMl polymorphism may confer susceptibility to the development of schizophrenia but not to TD, at least in Korean population.

수입각증후군에 의한 급성 복증 1례

정은욱,지삼룡,이영태,박지훈,김동기,제인수,채두근,박성재,박은택,이연재,이상혁,설상영,정정명 白中央醫療院 2005 仁濟醫學 Vol.26 No.1

Afferent loop syndrome is an uncommon complication of a gastrectomy and Billroth Ⅱ reconstruction. It may cause symtoms at any time from the first postoperative day to many years after the gastrectomy. Afferent loop syndrome is characterized by abdominal pain, vomiting and elevation of serum amylase. Thus, it is difficult to differentiate afferent loop syndrome from other cause of acute pancreatitis. However, the history of gastrectomy can be an important clue for diagnosing afferent loop syndrome. We experienced one case of chronic afferent loop syndrome with acute pancreatitis. After appropriate management, the abdominal pain disappeared and serum amylase level decreased. We report this case with a review of relevant literatures.

비스판 변이주인 Bacillus polyfermenticus KD21의 주요 생균제 특성

정민용,정황영,하정욱,백현동 慶南大學校 附設 基礎科學硏究所 2002 硏究論文集 Vol.16 No.-

Bacillus polyfermenticus SCD which is commonly called as Bispan strain are being used for functional foods using the treatment of long-term intestinal disorders, since the live strains in the form of active endospores can successfully reach the target intestine in both humans and animals. B. polyfermenticus KD21 was obtained for higher sporulation through the NTG mutagenesis. The cells of B. polyfermenticus KD21 was treated for 24 h in artificial bile after incubation for 2 h in artificial gastric juice and final number of the strain was reached to around 10^8 CFU/㎖. In test of API ZYM kit, β-glucuronidase or β-glucosidase were not produced by B. polyfermenticus KD21. B. polyfermenticus KD21 was resistant to antibiotics such as nisin, tetracyclin, streptomycin, and rifamycin. B. polyfermenticus KD21 was shown to inhibit the growth of Listeria monocytogenes ATCC 19111 completely within 24 h of incubation, which indicates its bactericidal nature.

단백질-다당질 복합겔의 용해도 및 전기영동 특성에 미치는 몇가지 첨가제의 영향

정경임,이동선,하정옥 경남대학교 신소재연구소 1996 論文集 Vol.6 No.-

본 연구에서는 닭고기에서 조제한 근원섬유 단백질(MP)과 MP와 유청 단백질 분리물(WPI)의 혼합물, MP와 대두 단백질 분리물(SPI)의 혼합물 등의 3가지 종류의 단백질과 다당질로서 methyl cellulose, sodium alginate, xanthan gum을 택하여 단백질-다당질의 복합겔을 만들고 NaCl, NaSCN, propylene glycol, 2-mercaptoethanol들의 처리에 의해 단백질-다당질간의 상호작용에 기인하는 겔의 용해도 및 전기영동에 의한 겔 용해에 따른 상징액의 변화 등을 조사함으로써 단백질 식품의 기능적 특성에 미치는 영향을 고찰해 보았다. 겔 용해도는 대체로 모든 다당질에 대해 낮은 용해도를 나타냈으나 세 가지 단백질 시료에 대해 2-mercaptoethanol 처리시 가장 많은 단백질이 용해되어 나온 것으로 나타났다. 2-mercaptoethanol은 단백질간 상호작용, 즉 겔 망상구조를 이루는 sdisulfide 결합을 크게 방해함으로써 가장 높은 용해도를 나타낸 것으로 생각된다. 모든 시료에 대해 NaCl과 NaSCN 용액에 대해서는 아주 낮은 용해도를 보였는데, 이것은 NaCl과 NaSCN은 저 농도일 경우, 단백질 구조를 안정화함으로써 단백질간의 상호작용이 크게 증가되어 용해되는 단백질의 양이 극히 낮아진 것으로 보인다. Xanthan gum은 가장 겔 용해도가 낮았고, 특히 MP와 xanthan gum으로 이루어진 겔에서는 아주 극소량의 단백질이 용해되었다. Methyl cellulose 겔의 경우, 모든 용액에서 단백질이 거의 용해되어 나오지 않았다. 그러나, 1% WPI를 혼합한 경우 역시 겔 용해도가 낮았으며 여전히 MP의 단백질 성분은 용해되어 나오지 않았고 WPI의 주요성분인 α-lactalbumin과 β-latcoblobulin이 많이 용해되어 나왔다. 1% SPI을 혼합한 겔은 셀 용해도도 여전히 낮았으며 전기영동 결과에서도 SPI 성분의 단백질 band가 아주 미약하게 나타났다. 이것으로 보아 WPI는 다소 불안정한 겔을 형성하여 용해도를 증가 시키고 반대로 SPI는 겔을 안정화하여 단백질 용해도를 감소시켰으리라 짐작된다. Sodium alginate 겔의 경우, 단백질 용해도는 아주 낮았으나 3 가지 단백질 시료 모두 용해되어 나왔다. 이것으로 sodium alginate는 단백질과 다소 불안정한 겔을 형성한다는 것을 알 수 있다. X무소무 gum 겔에서도 역시 MP와 MP+SPI 혼합겔은 아주 낮은 겔 용해도를 뒷받침하듯 단백질 band를 거의 확인할 수 없었으나 WPI를 혼합한 겔만이 WPI의 주요성분인 α-lactalbumin과 β-latcoblobulin 성분이 용해되어 나왔다. 즉, methyl cellulose와 xsanthan gum 겔의 경우, 근원섬유 단백질은 거의 용해되어 나오지 않았고 유청 단백질 분리물의 성분이 많이 용해되어 나왔으며 대두 단백질 분리물은 단백질과의 결합력이 커 용해된 단백질 성분이 아주 미약했다. Sodium alginate 겔의 경우 모든 단백질 성분이 용해되어 나온 것으로 보아 sodium alginate는 단백질과 결합하여 불안정한 겔을 형성하는 것으로 나타났다. Interactions between polysaccharides and proteins occur widely in biological system. Their interaction in food system often plays a role in determining the functional properties of these systems. The effects of various reagents such as NaCl. NaSCN. propylene glycol and 2-mercaptoethanol on the gel solubility of heat-induced gels of protein and polysaccharide were studied. Protein samples were myofibrillar proteins(MP) extracted from chicken breast muscle and the combinations of MP plus whey protein isolate(WP1) and MP plus soybean protein isolate(SP1). As polysaccharides in preparation of gels, methyl cellulose, sodium alginate and xanthan gum were used. Protein- polysaccharide composite gels were formed by heating at 80 C for 30 min. In the effects of reagents on gel solubility, 2-mercaptoethanol had higher solubility than other reagents. indicating that 2-mercaptoethanol cleaved disulfide bonds in the protein-polysaccharide composite gels. In order to indicate the composition of protein solubilized from gels by the treatment of various reagents such as 0.1 M NaC1. 0.1 M NaSCN. 20% propylene glycol, 0.04 M 2-mercaptoethanol, the solubilized proteins were analyzed by SDS-PAGE. In methyl cellulose and xanthan gum gels. less protein was solubilized by reagents, but MP gels with WPI was solubilized more abundantly than SPI.

酸棗仁이 CT105에 의한 신경세포 상해 및 白鼠의 기억에 미치는 영향

정정욱,박창국,박치상,이소연,윤현덕,신오철 대한본초학회 2005 大韓本草學會誌 Vol.20 No.1

Objective: This study was designed to research whether demonstrate neuroprotective and memory enhancing effects of Z1BU, suggesting its beneficial actions for the treatment of AD. Methods: The present study investigated effects of the dichloromethane extract of Semen Zizyphi Spinosae(ZIBU) on neurotoxicity and reactive oxygen species(ROS) and nitric oxide(NO) formation in PC 12 cell line overexpressed with carboxyl-terminal 105 amino acid peptide fragment of amyloid precursor protein(CT105). In addition, the present study evaluated its radical scavenging activity and effects on acetylcholinesterase(AChE) activity. Furthermore, effects on neuronal loss in CAl area and cognitive deficits induced by scopolamine treatment were also evaluated in rats. Result: we found in this study that ZIBU significantly inhibited apoptotic neuronal death induced by CT105 overexpression in PC12 cells, with the IC_(50) value of 23 ㎍/ml. Based on phase-contrast and fluorescence microscopic examinations, ZIBU reversed morphological changes of CT105-expressed PC-12 cells. It was also found that Z1BU significantly induced neurite outgrowth and inhibited formation of ROS and NO.Z1BU scavenged DPPH radicals and inhibited AChE activity. Furthermore, it attenuated memory impairment induced by the injection of scopolamine in rats, based on passive avoidance test. Crystal violet staining of rat brain slices exhibited increase in the viability of pyramidal neurons in hippocampal CAI area. Conclusion: these results demonstrate neuroprotective and memory enhancing effects of ZIBU, suggesting its beneficial actions for the treatment of AD.

주둥치, Leiognathus nuchalis(Temminck et Schlegel)의 仔稚魚期의 形態

明正求,金容億 釜山水産大學校 1984 釜山水産大學 硏究報告 Vol.24 No.1

南海昌善海峽에서 採集된 주둥치의 仔稚魚期에 있어서의 成長에 따른 外部形態, 體形 및 內部形態의 變化를 調査한 결과는 다음과 같다. 1. 주둥치는 後期仔魚期를 경과하는 동안 體長 4.1∼6.0㎜ 範圍에서 급격한 形態變化를 나타내고 體長 12. 3㎜에서 稚魚期에 도달한다. 2. 變態期인 體長 6.0㎜가지는 體長에 비해 꼬리부분이 가장 빨리 成長하며, 그 이후는 體高가 가장 빠른 속도로 成長하고 꼬리 부분은 가장 成長이 늦어진다. 3. 대부분의 骨格은 6.0㎜까지 骨化되며, 지느러미줄기는 體長12.3㎜에서 정수에 달한다. 4. 턱니는 거의 일정하게 증가하나 咽頭齒는 體長 6.0㎜경에 급격히 증가한다. 5. 消化管은 처음에 한번 廻轉되어 있으나, 體長6.0㎜부터 곧창자 앞부분이 굽어지기 시작하여, 體長 25.2㎜에는 한번 廻轉되고 두 번 銳角形으로 굽어진 形態가 된다. The morphological changes with growth Leiognathus nuchalis were investigated. Two hundred twenty one individuals were utilized for this study and its body length varied from 1.5 to 25.2㎜. These specimens were collected in changson channel, Namhae during the summer season (June-July) in 1982 and 1983. The metamorphosis was recognized in the post larval stage between ca. 4.1㎜ and 6.0㎜ in body length. Up to metamorphosis, the tail developed faster than any other body part. However, after metamorphosis the body height developed the fastest and the tail the slowest. Metamorphosis brought about not only ossification of many elements, but also exchange of larval features to adult ones. The latter happened typically to jaw bones and preopercles. The unpaired fins developed earlier than the paired fins. the dorsal and anal fin rays were at first formed when the body length was ca. 4.1㎜, and as it attained ca. 5.8㎜, the number of the fin rays reached of the adult's ones. In The unpaired fins, the development of the caudal fin preceded that of the dorsal and anal fins. Each fin formation was completed when the body length was ca. 12.3㎜, and this post larva entered juvenile stage. Upper jaw teeth were formed only on the premaxillary. While the numbers of teeth on the jaw increased almost constantly, those on the upper and lower pharyngeal bones increased in proportion to body length with a more or less conspicuous leap when the ./body length was ca. 6.0㎜. The alimentary canal of L.nuchalis had a single winding form until the body length was 6.0㎜, and the thereafter, it became to develop a sharp bend followed by a outward second bend.

일부 지역 학동기 아동의 우발사고에 대한 조사

모정욱,심운택,이태용 충남대학교 의과대학 지역사회의학연구소 1991 충남의대잡지 Vol.18 No.2

The purpose of this study was to investigate school children's monthly incidence rates and causes of accident. The number of studied subjects were 279 school children. The results were as follows: 1. Average monthly incidence rate of accident for male was 17.8 per 100 persons, and that of female was 12.7. That of the 6th grade was 32.7, and the 1st grade was 5.6, and March was the highest in incidence rate of studied months. 2. The accidents occured most frequently in the 6th grade and relatively low in the 1st grade. 3. The presence of parents, their occupation, and education and monthly income of household were not affected school children's accident. 4. Time required and distance from house to school were concerned to children's accident. Walking was relatively lower than other way in the way of transport from house to school. 5. The majority sites of injury were legs & arms. 6. Most of injured children treated at the medical institute.

구기자, 오미자 및 결명자의 아질산염 소거작용

하정욱,황용일,윤이란 慶南大學校 附設 工業技術硏究所 1999 硏究論文集 Vol.17 No.-

기호음료의 재료인 구기자, 오미자, 및 결명자 등으로부터 물 추출물과 메탄올 추출물을 조제한 다음, phenol 화합물의 함량, 전자공여작용 및 아질산염 소거작용 등을 관찰하고, 이들 요인 간의 상관관계를 검토하였다. 추출물 중 오미자와 결명자의 메탄올 추출물이 비교적 높은 전자공여작용을 나타내었고, 방향족 화합물의 함량은 결명자>구기자>오미자의 순이었다. 물추출물의 아질산염 소거작용은 pH 1.2에서 구기자가 85.61%로 가장 현저하였고, 소거율은 구기자>오미자>결명자의 순이었으며, pH의존적으로 감소하였다. 메탄올 추출물의 아질산염 소거작용은 pH 1.2에서 구기자 96.03%. 결명자 89.38%. 및 오미자 87.23%로 매우 높은 소거율을 보였으며, pH 증가시 급격하게 감소하는 경향을 나타내었다. 그리고. 아질산염 소거작용과의 상관관계면에서 전자공여작용은 비교적 낮은 상관계수를 나타내었고, 방향족 화합물은 낮은 pH에서는 비교적 높은 값을 보였으나, pH 6.0에서는 상관관계를 거의 볼 수 없었다. 그리고 전반적으로 메탄올 추출물이 물 추출물에 비해 높은 아질산염 소거율을 유지하였다. This study was conducted to investigate the content of phenolic compounds, electron donating ability(EDA) and nitrite scavenging ability of water extracts and methanol extracts from Lycium chinese Mill Shizanda chinensis Baillon, and Cassia tora L. Methanol extracts from Shizandra chinensis Baillon showed comparatively higher EDA, and the content of phenolic compounds was in the sequence of Cassia tora L.>Lycium chinense Mill>Schizandra chinensis Baillon. The nitrite scavenging ability of water extracts from Lycium chinense Mill showed higher ratio of 85.61% than Shizandra chinensis Baillon and Cassia tora L. at pH 1.2, and decreased remarkably in the higher range of pH. The nitrite scavenging ratios of methanol extracts were 96.03% of Lycium chinense Mill, 89.30% of Cassia tora L. and 87.23% of Shizandra chinensis Baillon and the decreasing tendency was clearly pH-dependent. Generally methanol extracts showed higher coefficients than water extracts and the content of phenolic compounds had higher coefficients at lower pH range against nitrite scavenging ability.

시금치 및 마늘의 아질산염 소거작용 및 전자공여작용

하정욱,이승철,윤이란 경남대학교 공업기술연구소 2000 硏究論文集 Vol.18 No.-

주요 야채 및 향신료로 이용되고 있는 시금치와 마늘로부터 물 추출물과 메탄을 추출물을 조제한 다음, phenol 화합물의 함량, 전자공여작용 및 아질산염 소거작용 등을 측정하고 검토하였다. 시금치와 미늘의 methanol 추출물이 물 추출물보다는 다소 높은 전자공여 작용을 나타내었으며, 방향족 화합물의 함량은 시금치의 methanol 추출물과 마늘의 물 추출물이 다른 두 종류의 추출물 보다는 비교적 높은 전자공여작용을 보였다. 그리고 물 추출물과 methanol 추출물 중에서 pH1.2에서 마늘의 물 추출물이 98.62%로 가장 두드러진 아질산염 소거율을 나타내었으며, 이 외에는 아질산염 소거작용면에서 거의 전반적으로 methanol 추출물이 물 추출물보다는 훨씬 효과적이었다. This study was conducted to investigate the electron donating ability(EDA) and nitrite scavenging ability of water extracts and methanol extracts from spinach and garlic-bulb. Methanol extracts from two samples showed comparatively higher EDA, and the content of phenolic substances of methanol extract from spinach and water extract from garlic-bulb was more than another extracts. The nitrite scavenging ability of water extracts from garlic-bulb showed the highest ratio of 98.62% among those extracts at pH1.2 and the decreasing tendency was clearly pH-dependent. Generally methanol extracts from two samples showed higher effective nitrite scavenging abilities than water extracts.