• 공업화학
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• 제32권4호
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• pp.472-477
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• 2021

다면체 올리고머 실세스퀴옥산 (POSS) 중 케이지 형태 8개의 아크릴레이트 그룹을 포함하는 POSS가 에틸렌-프로필렌-디엔고무 (EPDM) 과산화물 가교에서의 가교 거동, 기계적 특성에 미치는 영향 및 열 안정성 등을 조사하였다. 고무 100 phr당 0~12 phr의 POSS를 함량 별로 혼합하고 과산화물 가교제를 첨가하여 EPDM/POSS 복합재료를 만들었다. 가교 특성 결과 POSS의 아크릴레이트 그룹이 과산화물에 의해 활성화 되었고, 과산화물 가교 효율을 향상시키는 것으로 나타났다. EPDM/POSS 복합재료에서 POSS의 분산안정성은 떨어졌지만, 복합재료의 파단 강도, 신장률 및 열 안정성은 향상되었다.

• 한국자기학회지
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• 제4권3호
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• pp.214-218
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• 1994

페리마그넷(Ferrimagnetic) $Y_{3}Fe_{5}O_{12}$(Garnet) 박막 또는 후막은 초고주파 대역에서 사용하는 통신부품의 소자로서 핵심 역할을 하고 있다. 본 연구에서는 요즘 신기술로 소개된 펄스 레이저 증착기술(Laser Ablation Technique)에 의하여 가넷의 표준조성인 $Y_{3}Fe_{5}O_{12}$ 후막을 에피성장 시키는데 성공하였다. KrF 가스를 사용한 Eximer 레이저를 10 Hz의 펄스주파수로 $Al_{2}O_{3}$(1102) 면에서 거의 집합조직의 에피후막을 성장시켰다. 후막의 자기특성 및 성장 양상은 사용한 기판 및 기판온도와 산소분압에 따라 결정되지만 본 연구에서 얻어진 최적의 자기특성은 가넷두께 $4.1\;\mu\textrm{m}$에서 $4{\pi}M_{s}=1300$ Gauss, $H_{c}=37.5$ Oe 의 값을 산소분압 100 mTorr 및 기판온도 $600^{\circ}C$에서 증착한 후 $700^{\circ}C$에서 2시간 소둔처리하여 최적값을 얻을 수가 있었다. 이러한 가넷후막은 협대역 주파수 범위에서 Magnetostatic Spin Wave 원리를 이용한 Filter로 사용 가능하다.

• Journal of Korean Neurosurgical Society
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• 제58권2호
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• pp.93-100
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• 2015

Objective : Optimal treatment decision and estimation of the prognosis in traumatic brain injury (TBI) is currently based on demographic and clinical predictors. But sometimes, there are limitations in these factors. In this study, we analyzed three central nervous system biomarkers in TBI patients, will discuss the roles and clinical applications of biomarkers in TBI. Methods : From July on 2013 to August on 2014, a total of 45 patients were included. The serum was obtained at the time of hospital admission, and biomarkers were extracted with centrifugal process. It was analyzed for the level of S-100 beta (S100B), glial fibrillary acidic protein (GFAP), and ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1). Results : This study included 33 males and 12 females with a mean age of 58.5 (19-84) years. TBI patients were classified into two groups. Group A was severe TBI with Glasgow Coma Scale (GCS) score 3-5 and Group B was mild TBI with GCS score 13-15. The median serum concentration of S100B, GFAP, and UCH-L1 in severe TBI were raised 5.1 fold, 5.5 fold, and 439.1 fold compared to mild injury, respectively. The serum levels of these markers correlated significantly with the injury severity and clinical outcome (p<0.001). Increased level of markers was strongly predicted poor outcomes. Conclusion : S100B, GFAP, and UCH-L1 serum level of were significantly increased in TBI according to severity and associated clinical outcomes. Biomarkers have potential utility as diagnostic, prognostic, and therapeutic adjuncts in the setting of TBI.

• 한국잡초학회지
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• 제7권1호
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• pp.84-89
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• 1987

HBR[(22s, 23s)-homobrassinolide]과 auxin류(類)의 생장조절제(生長調節劑) 단독(單獨) 또는 혼용(混用) 처리시(處理時) 무우 자엽병(子葉柄)의 상편생장(上偏生長)(굴절(屈折))에 어떻게 影響(影響)을 마치는가를 구명(究明)하여 얻어진 결과(結果)를 요약(要約)하연 다음과 같다. 1. HBR 단독처리(單獨處理)는 농도(濃度)에 관계(關係)없이 무우 자엽병(子葉柄) 굴절(屈折)에 영향(影響)하지 않았다. 2. 천연식물생장조절제(天然植物生長調節劑) IAA, IBA, NAA의 굴절효과(屆折效果)는 짧았고 IAA는 처리후(處理後) 4(시간(時間)), IBA는 12~24 시간(時間), NAA는 12 시간(時間) 지나면 감소(減少)하였다. 이 가운데 NAA 100ppm 처리구(處理區)에서 가장 높았고 IAA 처리(處理)에서 전반적으로 가장 높았고 IAA 처리(處理)에서 전반적으로 가장 효과(效果)가 낮았다. 3. 합성(合成) auxin 류(類)인 MCP나 2, 4-D의 굴절효과(屈折效果)는 대체로 36시간(時間) 지속(持續)되었으며 고농도(高濃度)인 100 ppm에서 무처리(無處理)에 3배(倍) 이상(以上) 증대(增大)시켰다. 30ppm 이하(以下)의 저농도(低濃度)에서는 효과(效果)도 작고 농도간(濃度間) 차(差)도 작았다. 4. NAA와 HBR의 혼용(混用)은 NAA 100ppm 처리(處理)에서 HBR 100 ppm 단독(單獨)보다 약(約) 3배(倍) 증대(增大)시켰으나 30 ppm 이하(以下)의 농도(濃度)에서는 큰 차이(差異)가 없었다. 5. HBR에 MCP 3ppm의 혼용(混用)은 HBR 단독처리(單獨處理)에 비(比)하여 굴절각(屈折角)을 약(約) 3배(倍) 증대(增大)시켰다. HBR과 2.4-D의 혼용(混用)은 농도(濃度)가 증가(增加)할수록 굴절각(屈折角)의 반응(反應)이 크게 나타났으며 100 ppm 혼용(混用)에서 HBR 단독처리(單獨處理)에 비(比)하여 약(約) 8배(倍) 증가(增加)시켰다.

• Journal of Trauma and Injury
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• 제22권2호
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• pp.123-127
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• 2009

Purpose: There is an increasing amount of evidence that S100B could function as a marker of brain damage. However, the cerebral specificity of S100B has been questioned, so the extracerebral sources of S100B have been paid attention. We performed this investigation to show serum S100B levels after extracranial fracture in patients without current head injury and without prior neurological disease. Methods: At the emergency department, we obtained the blood samples within 6 hours from trauma patients hospitalized with extracranial fractures. S100B levels were compared between one fracture and more than two fractures, and analyzed according to the presence of soft tissue damage. Results: Patients with one fracture and those with more than two fractures did not differ by age (mean, 54.70 vs. 47.03, p=0.130), and there was no significant difference in the male-to-female ratio(33:32 vs. 21:12, p=0.226). In patients with one fracture, the mean value of S-100B was $0.56{\mu}g/L$ (95% CI: 0.35-0.77) whereas in those with more than two fractures, the corresponding value was $1.09{\mu}g/L$ (95% CI: 0.46-1.7, p=0.048). The S100B level of patients with soft tissue damage($1.32{\pm}0.38$) was higher than that of patients without soft tissue damage($0.81{\pm}0.21$), whether one fracture or more than two fractures(p=0.049). Conclusion: We present here that S100B levels were raised in 77% of patients with extracranial fractures without cerebral injury who were hospitalized from the emergency room and that the presence of soft tissue damage contributed to the increased S100B rather than the size of the fractured bone size or the number of fracturest. Thus, this study suggests that soft tissue injury may be considered as an important extracerebral source of S100B.

• Journal of Korean Neurosurgical Society
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• 제61권5호
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• pp.548-558
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• 2018

Objective : Diagnosing acute cerebral infarction is crucial in determining prognosis of stroke patients. Although many serologic tests for prompt diagnosis are available, the clinical application of serologic tests is currently limited. We investigated whether $S100{\beta}$, matrix metalloproteinase-9 (MMP-9), D-dimer, and heat shock protein 70 (HSP70) can be used as biomarkers for acute cerebral infarction. Methods : Focal cerebral ischemia was induced using the modified intraluminal filament technique. Mice were randomly assigned to 30-minute occlusion (n=10), 60-minute occlusion (n=10), or sham (n=5) groups. Four hours later, neurological deficits were evaluated and blood samples were obtained. Infarction volumes were calculated and plasma $S100{\beta}$, MMP-9, D-dimer, and HSP70 levels were measured using enzyme-linked immunosorbent assay. Results : The average infarction volume was $12.32{\pm}2.31mm^3$ and $46.9{\pm}7.43mm^3$ in the 30- and 60-minute groups, respectively. The mean neurological score in the two ischemic groups was $1.6{\pm}0.55$ and $3.2{\pm}0.70$, respectively. $S100{\beta}$, MMP-9, and HSP70 expressions significantly increased after 4 hours of ischemia (p=0.001). Furthermore, $S100{\beta}$ and MMP-9 expressions correlated with infarction volumes (p<0.001) and neurological deficits (p<0.001). There was no significant difference in D-dimer expression between groups (p=0.843). The area under the receiver operating characteristic curve (AUC) showed high sensitivity and specificity for MMP-9, HSP70 (AUC=1), and $S100{\beta}$ (AUC=0.98). Conclusion : $S100{\beta}$, MMP-9, and HSP70 can complement current diagnostic tools to assess cerebral infarction, suggesting their use as potential biomarkers for acute cerebral infarction.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.267-270
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• 2003

백화사설초에 함유되어 있는 oleanolic acid를 세포배양을 이용하여 생산하기 위한 연구를 수행하였다. Oleanolic acid를 생산하기 위해, 백화사설초의 캘러스와 현탁세포를 2,4-D 0.5 mg/L, kinetin 0.1 mg/L가 포함된 SH 배지에서 유도하였다. Oleanolic acid의 분석을 위해, Rexchrom S5-100-ODS column을 사용한 HPLC를 이용하였다. 분석 결과, oleanolic acid의 retention time은 12.6분 이었고, 그 양은 0.41 mg/g dry weight였다.

• 한국동물생명공학회지
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• 제35권2호
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• pp.190-197
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• 2020

The effects of the number of frozen-thawed ram sperm per single and double intra-cervical artificial insemination (AI) on fertility in ewes were studied. A total of 89 non-pregnant ewes were synchronized for oestrus with two doses of 100 ㎍ PGF_2α (Cloprostenol) 9 days apart. The ewes were randomly assigned to one of four groups; D200 (n = 23; double AI with 200 × 10⁶ sperm), S200 (n = 24; single AI with 200 × 10⁶ sperm), D100 (n = 24; double AI with 100 × 10⁶ sperm) and S100 (n = 18; single AI with 100 × 10⁶ sperm). Ewes were inseminated within 12 to 18 h for single AI and, within 10 to 12 h and 16 to 18 h for double AI after the onset of oestrus. The onset of oestrus ranged from 28 to 76 h (54.33 ± 1.28 h). The high percentage (29.2%) of ewes showed oestrus between 51 to 60 h. The non-return rates were highest in group D200 (56.5%) and differed significantly (p < 0.05) from group S100 (11.1%). No ewes were pregnant in group S100, and the pregnancy rates among the remaining groups did not differ. The mean gestation period was 152.8 ± 0.5 days and no difference was observed among the groups. The lambing and multiple birth rates were 100% in group D200. The single and twin lambing was highest in group D100 (33.3%) and group D200 (83.3%), respectively. Only one triplet lambing and the highest lambing size (2.2 ± 0.2) was recorded in group D200. In conclusion, double AI with 200 × 10⁶ sperm showed comparatively most practical for achieving high pregnancy rates and lambing performances in Bangladeshi ewes under field conditions.

• Steel and Composite Structures
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• 제47권3호
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• pp.437-450
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• 2023

A half open cross section built-up column, namely cold-formed thin-walled steel built-up column with 12-limbsection (CTSBC-12) is put forward. To deeply reveal the mechanical behaviors of CTSBC-12 under axial compression and put forward its calculation formula of axial bearing capacity, based on the previous axial compression experimental research, the finite element analysis (FEA) is conducted on 9 CTSBC-12 specimens, and then the variable parameter analysis is carried out. The results show the FEA is in good agreement with the experimental research, the ultimate bearing capacity error is within 10%. When the slenderness ratio is more than 96.54, the ultimate bearing capacity of CTSBC-12 decreases rapidly, and the failure mode changes from local buckling to global buckling. With the local buckling failure mode unchanged, the ultimate bearing capacity decreases gradually as the ratio of web height to thickness increases. Three methods are used for calculating the ultimate bearing capacity, the direct strength method of AISI S100-2007 gives result of ultimate axial load which is closest to the test and FEA results. But for simplicity and practicality, a simplified axial bearing capacity formula is proposed, which has better calculation accuracy with the slenderness ratio changing from 30 to 100.

• 한국미생물·생명공학회지
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• 제29권2호
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• pp.78-83
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• 2001

본 연구는 phytic acid를 myo-inositol과 무기태인으로 분해시키는 효소인 phytase 생산균주의 분리 및 효소생산의 배지최적하에 관한 것이다. 1차로 calcium phytate를 기질로 함유한 phytase screening 배지를 이용하여 phytase 생산을 나타내는 균주 35가지를 이용하여 분리한 후, sodium phytate를 기질로 하여 재현성 있는 phytase 활성을 나타내는 균주 12가지를 선발하였다. 12개의 균주 중 BHI broth에서 배양한 조효소액의 phytase 활성이 가장 우수한 것으로 나타난 YH100을 선발하여 주사현미경 관찰, 16S rRNA sequence 분석, GC conten(mol%) 조성, 지방산 분석, API 20E kit를 이용한 test 결과 Enterobacter cloacae로 동정되어, 이 균주를 Enterobacter cloacae YH100이라 명명하였다. Enterobacter cloacae YH100에 의한 phytase 생산을 위한 최적 배지 조성을 파악한 결과 glucose 2.0%(w/v), peptone 1.0%(w/v), beef extract 1.0%(w/v), KCI 0.1%(w/v), sodium phytate 0.1%(w/v)로 나타났다.