• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.472-477
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• 2021

The crosslinking behavior of polyhedral oligomeric silsesquioxane (POSS) containing eight acrylate groups in a cage form in ethylene-propylene-diene rubber (EPDM) peroxide crosslinking, the effect on mechanical properties, and the thermal stability were investigated. An EPDM/POSS composite material was prepared by mixing 0 to 12 parts per hundreds of rubber (phr) of POSS per 100 phr of rubber by content and adding a peroxide crosslinking agent. As a result of crosslinking properties, it was found that the acrylate group of POSS was activated by peroxide and improved the peroxide crosslinking efficiency. Although the dispersion stability of POSS in EPDM/POSS composites was poor, the fracture strength, elongation and thermal stability were improved.

• Journal of the Korean Magnetics Society
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• v.4 no.3
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• pp.214-218
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• 1994

$Y_{3}Fe_{5}O_{12}$ based garnet films(thin or thick) offer a great promise for the application of microwave communication components. We investigated the magnetic and crystallographic preperties of $Y_{3}Fe_{5}O_{12}$ thick films prepared by KrF eximer laser ablation of a stoichiometric garnet target. It was possible to obtain almost epitaxially oriented films on $Al_{2}O_{3}$(1102) plane. Although the crystalline quality depends on substrate temperature and $O_{2}$ partial pressure used($Po_{2}$), 4.1m thick films of $4{\pi}M_{s}=1300$ Gauss and $H_{c}=37.5$ Oe were obtained at the substrate temperature of $700^{\circ}C$ with the $Po_{2}$ of 100 mTorr after annealing the as-deposited films at $700^{\circ}C$ for 2 hours. These films are expected to be used for magnetostatic spin wave filters at narrow bandwidth frequency.

• Journal of Korean Neurosurgical Society
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• v.58 no.2
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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.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.84-89
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• 1987

This study was conducted to determine the combining effects of a synthetic brassinolide such as homobrassinolide (HBR) with auxin types on the curvature of radish petiole. HBR has no direct effect on the petiole curvature of radish, regardless of concentrations used. Among the natural known plant growth regulators, NAA at 100ppm showed the highest ourvature at 12 hours after treatment. The synthetic auxins such as 2,4-D and MCP resulted in about three times greater effect on curvature than the untreated control, and their effects lasted till 36 horns after treatment, showing much better effect on curvature than that of the natural auxin types of plant growth regulators. The mixture of MCP at 3 ppm with HBR at 100ppm increased petiole curvature of radish seedlings as much as three times greater than that of a single application of HBR. However, the mixture of HBR at 100 ppm plus 2, 4-D at 100ppm increased the petiole curvature of radish seedlings about eight times greater than that of the HBR single application, showing existance of strong synergistic reaction and the most effective combination, and suggesting possibility of a prectical implementation in agriculture.

• Journal of Trauma and Injury
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• v.22 no.2
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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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• v.61 no.5
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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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• 2003.04a
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• pp.267-270
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• 2003

Oleanolic acid is a triterpenoid compound that exists in Oldenlandia diffusa. Recently, oleanolic acid has been noted for antitumor effect. Application of both plant growth regulators, 2,4-D and kinetin, was found to be essential for the induction of callus and suspension cells. Optimum induction condition for callus and suspension cells of Oldenlandia diffusa was determined to be 0.5 mg/L 2,4-D and 0.1 mg/L kinetin. Chromatographic separation of oleanolic acid from its derivatives was achieved using Rexchrom S5-100-ODS column. The retention time of oleanolic acid was 12.6 min and the specific content of oleanolic acid was 0.41 mg/g dry weight.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.2
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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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• v.47 no.3
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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.

• Microbiology and Biotechnology Letters
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• v.29 no.2
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• pp.78-83
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• 2001

Phytase (myo-inositol hexakisphosphate phosphohydrolase: EC 3.1.3.8) hydrolyzes phytic acid (myo-inositol hexakisphosphate) to myo-inositol and monophosphates. In order to obtain phytase producing bacteria, many samples were collected from various soils. Among thirty-five phytase-producing strains, YH100 showed the highest phytase activity. In order to identify the selected YHlOO strain, the morphological and physiological characteristics were examined according to the method of Bergey's manual by 168 rRNA sequence, cellular fatty acids profile, O+C contents and physiological test using API 20E kit. The strain YH100 identified to be a genus of Enterobacter cloacae and was named as Enterobacter cloacae YHlOO. Optimum medium for the phytase production by the Entemhacter c!o([we YHlOO was composed of 2.0%(w/v) glucose, 1.0%(w/v) peptone, 1.0%(w/v) beef extract, 0.1 %(w/v) KCI. and 0.1 %( w/v) sodium phytate.