• Journal of the Korean Society of Propulsion Engineers
• /
• v.17 no.5
• /
• pp.18-26
• /
• 2013

This study suggested techniques to reduce burning rate and their effects for the AP thermoplastic composite propellant. Burning rate obtained through ground tests using a small size motor were analyzed to investigate the effects of AP particle size and LiF of 0.5~2.0% on the inhibition reaction for the PEBAX/AP thermoplastic propellant. The results showed that utilization of large size particle of AP and addition of LiF under 2.0% can reduce the burning rate sufficiently and their quantitative effects were suggested in this paper.

• Journal of Korean Academy of Nursing
• /
• v.46 no.5
• /
• pp.720-732
• /
• 2016

Purpose: This study was done to develop a Web-based preconception health promotion program to improve preconception health promotion awareness, perceived benefits, perceived self-efficacy and health behavior, and to reduce perceived barriers in couples about to be married. Methods: Participants were assigned to the experimental group (n=26 couples) or control group (n=25 couples). This program was comprised of a six hour Web-based lecture series which was given to the experimental group over a four week period. Results: Results for the two groups showed: 1) a significant difference in preconception health promotion awareness in men (self-perception: z=-3.62, p <.001 content: F=18.49, p <.001) and in women (self-perception: z=-2.89, p =.004 content F=36.93, p <.001), 2) a significant difference in perceived benefits in men (z=-3.09, p =.002), and in women (F=6.38, p =.004), 3) a significant difference in perceived barriers in men (F=3.64, p =.030), and in women (F=11.36, p <.001), 4) a significant difference in perceived self-efficacy in men (F=12.16, p <.001), but no significant difference in women (F=1.93, p =.166), 5) a significant difference in health promoting behavior in men (F=16.31, p <.001), and in women (F=10.99, p =.001). Conclusion: The results of this study show that the program is an effective nursing intervention in couples about to be married. Therefore, this program can be useful in encouraging health-promoting behavior for couples about to be married.

• The Korean Journal of Nuclear Medicine
• /
• v.38 no.2
• /
• pp.198-204
• /
• 2004

Tumor cell proliferation is considered to be a useful prognostic indicator of tumor aggressiveness and tumor response to therapy but in vitro measurement of individual proliferation is complex and tedious work. PET imaging provides a noninvasive approach to measure tumor growth rate in situ. Early approaches have used $^{18}F$-FDG or methionine to monitor proliferation status. These 2 tracers detect changes in glucose and amino acid metabolism, respectively, and therefore provide only an indirect measure of proliferation status. More recent studies have focused on DNA synthesis itself as a marker of cell proliferation. Cell lines and tissues with a high proliferation rate require high rates of DNA synthesis. $[^{11}C]Thymidine$ was the first radiotracer for noninvasive imaging of tumor proliferation. The short half-life of $^{11}C$ and rapid metabolism of $[^{11}C]Thymidine$ in vivo make the radiotracer less suitable for routing use. Halogenated thymidine analogs such as 5-iodo-2-deoxyuridine (IUdR) can be successfully used as cell proliferation markers for in vitro studies because these compounds are rapidly incorporated into newly synthesized DNA. IUdR has been evaluated as a potential in vivo tracer in nuclear medicing but the image qualify and the calculation of proliferation rates are impaired by its rapid in vivo degradation. Hence, the thymidine analog $3'-deoxy-3'-^{18}F-fluorothymidine$ (FLT) was recently introduced as a stable proliferation marker with a suitable nuclide half-life and stable in vivo. $[^{18}F]FLT$ is phosphorylated to 3-fluorothymidine monophosphate by thymidine kinase 1 and reflects thymidine kinase 1 activity in proliferating cell. $[^{18}F]FLT$ PET is feasible in clincal use and well correlates with cellular proliferation. Choline is a precursor for the biosynthesis of phospholipids (in particular, phosphatidylcholine), which is the essential component of all eukaryotic cell membranes and $[^{11}C]choline$, which is a new marker for cellular proliferation.

• Journal of Radiopharmaceuticals and Molecular Probes
• /
• v.9 no.1
• /
• pp.3-8
• /
• 2023

Parkinson's disease is a neurodegenerative disease caused by damage to brain neurons related to dopamine. Non-clinical animal models mainly used in Parkinson's disease research include drug-induced models of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 6-hydroxydopamine, and genetically modified transgenic animal models. Parkinson's diagnosis can be made using brain imaging of the substantia nigra-striatal dopamine system and using a radiotracer that specifically binds to the dopamine transporter. In this study, ¹⁸F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane was used to confirm the image evaluation cutoff between normal and parkinson's disease models, and to confirm model persistence over time. In addition, the efficacy of single or combined administration of clinically used therapeutic drugs in parkinson's animal models was evaluated. Image analysis was performed using the PMOD software. Converted to standardized uptake value, and analyzed by standardized uptake value ratio by dividing the average value of left striatum by the average value of right striatum obtained by applying positron emission tomography images to the atlas magnetic resonance template. The image cutoff of the normal and the parkinson's disease model was calculated as SUVR=0.829, and it was confirmed that it was maintained during the test period. In the three-drug combination administration group, the right and left striatum showed a high symmetry of more than 0.942 on average and recovered significantly. Images using ¹⁸F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane are thought to be able to diagnose and evaluate treatment efficacy of non-clinical Parkinson's disease.

• Journal of Life Science
• /
• v.34 no.9
• /
• pp.639-646
• /
• 2024

This study was conducted to select a probiotic strain using Bacillus strains living in the intestines of Protaetia brevitarsis seulensis larvae. To select Bacillus strains, the ones derived from Protaetia brevitarsis seulensis larvae were heated at 80℃ for 10 min, Subsequently, they were appropriately diluted and screened primarily for carboxymethyl cellulase (CMCase) activity, followed by secondary selection based on protease activity. Among the selected strains, the F23-72 strain exhibited excellent CMCase and protease activities. This strain was identified as Bacillus velezensis F23-72 through 16S rDNA analysis. F23-72 showed similar activity to B. velezensis KACC10334 and K10 for CMCase, avicelase, cellobiase, xylanase, and mannanase, indicating the excellent functionality of extracellular enzymes. While its auto-aggregation was higher than L. plantarum K9, it was lower than B. velezensis K10. However, its co-aggregation with pathogenic strains and mucin adhesion was lower than with L. plantarum K9. These characteristics suggest that Bacillus strains generally have low adhesion to the intestinal mucosa and a low ability to remove pathogenic bacteria. B. velezensis F23-72 exhibited slightly superior antibacterial activity against Staphylococcus aureus and Salmonella Typhimurium compared to KACC10334 and K10, with the best results observed at 18 and 24 hr. In conclusion, B. velezensis F23-72 demonstrates excellent extracellular enzyme activity and antibacterial properties, but low mucosal adhesion and pathogenic bacteria removal ability, suggesting its potential use as a probiotic to aid in digestion.

• Applied Chemistry for Engineering
• /
• v.30 no.2
• /
• pp.155-159
• /
• 2019

As a part of improving the quality for the fraction of the waste plastics pyrolysis oil (WPPO), the recovery of paraffin components contained in the fraction was investigated by dimethylformamide (DMF) equilibrium extraction. The fraction of a distilling temperature of $120{\sim}350^{\circ}C$ recovered from WPPO by the simple distillation and the aqueous solution of DMF were used as a raw material and solvent, respectively. The concentrations of paraffin components ($C_{12}$, $C_{14}$, $C_{16}$ and $C_{18}$) contained in the raffinate decreased by increasing the mass fraction of water in the solvent at an initial state ($y_{w,0}$), whereas, the concentrations of paraffin components contained in the raffinate increased by increasing the mass ratio of the solvent to the feed at an initial state $(S/F)_0$. The concentrations of $C_{12}$, $C_{14}$, $C_{16}$ and $C_{18}$ paraffin components present in the raffinate recovered at $(S/F)_0=10$ were about 1.37, 2.0, 2.46 and 3.16 times higher than those of the raw materials, respectively. Recovery rates (residue rates present in raffinate) of paraffin components rapidly increased with increasing $y_{w,0}$, and decreasing $(S/F)_0$. The raffinate recovered through this study was expected to be used as a renewable energy.

• Korean Journal of Animal Reproduction
• /
• v.27 no.1
• /
• pp.9-14
• /
• 2003

The pBT-L transgenic mice carrying human TPO gene in conjunction with bovine $\beta$-casein promoter express human TPO in milk during lactation. In this study, stability of germ line transmission and expression of pBT-L transgene integrated into host chromosome were monitored up to generation F10 of transgenic pBT-L/15 line. When male mouse of generation F8 was crossbred with normal females, approximately half of offsprings (51.3$\pm$18.98%) were identified as transgenic mice. Generation F9 and F 10 mice also showed similar transmission rates (43.8$\pm$18.98% and 71.4$\pm$26.98%, respectively), implying that pBT-L transgene can be transmitted stably up to long term generation in the transgenic mice. Expression levels of human TPO from milk of generation F9 and F10 mice were 1.1$\pm$0.33 mg/ml and 1.1 $\pm$0.45 mg/ml, respectively, which are similar to expression level of generation F2 mice. In conclusion, our results suggest that transgenic animals once established will continuously pass their transgenes to the progeny through the breeding program with the same productivity of human protein in their milk.

• Korean Journal of Plant Resources
• /
• v.35 no.2
• /
• pp.346-361
• /
• 2022

Food poisoning accidents caused by poisonous plants occur every year. As certain poisonous plants are mistaken for edible plants causing food poisoning, accurate species identification of poisonous plants is required. DNA barcodes suitable for species identification of poisonous plants and database that can be used for accurate species identification are necessary for their use in forensic cases. In this study, species identification of 19 poisonous plants native to Jeju Island using seven DNA barcodes (trnH-psbA, trnL-trnF, trnL intron, rbcL, matK, ITS1-ITS4, 18S rRNA) was performed to construct a database containing sequence information and DNA barcode universality. trnL-trnF barcode and ITS1-ITS4 barcode were the easiest markers for PCR amplification and sequence retrieval, and the combination of the two barcodes enabled single species identification in 18 out of 19 plants. Therefore, when an investigation of unknown poisonous plants is requested, combination of trnL-trnF and ITS1-ITS4 barcodes is considered as a primary marker for species identification. The database of recommended DNA barcodes for each poisonous plant presented in this study will be helpful in plants poisoning cases.

• Journal of Biosystems Engineering
• /
• v.27 no.2
• /
• pp.89-96
• /
• 2002

The trend of consumption of vegetable soybeans is increasing because they are recognized as the clean vegetable. The works requiring the most intensive labor are threshing and seperation ones, and they form about 80% of total labour for vegetable soybeans production. It is necessary to develop the vegetable soybeans-thresher for the sake of cost down of vegetable soybeans production. The purpose of this study is to acquire the basic informations to design of the vegetable soybeans-thresher. We make the experimental system which control the speed of threshing cylinder and the teeth gap and investigate the detachment forces. The result are as follows ; The ratio of un-threshed soybeans-pod to stem after threshing work is decreasing as the threshing cylinder speed increases: 0.0% and 2.8% at 55m/s and 18m/s of threshing cylinder speed respectively. Also the ratio of un-threshed soybeans-pod to stem is shown as 2.0% below in the condition of 64~160mm of teeth gap and over 28m/s of threshing cylinder speed. The damaged pod ratio of detached soybeans after threshing work is decreasing as the threshing cylinder speed increases: 4.8% and 1.3% at 55m/s and 18m/s of threshing cylinder speed respectively. The minimum damaged pod ratio of detached soybeans are shown as 1.0%, 1.5% and 1.9% at 18m/s, 28m/s and 37m/s of threshing cylinder speed respectively. The average detachment forces of pods are shown as 1.5kg$_{f}$ for 3 grains, 1.2kg$_{f}$ for 2 grains and 0.8kg$_{f}$ for 1 grain respectively. The maximum detachment force of pod is shown as 2.7kg$_{f}$ for 3 grains. grains.

• The Korean Journal of Nuclear Medicine
• /
• v.33 no.5
• /
• pp.439-451
• /
• 1999

Purpose : It is important to differentiate malignant from benign lesions of intraocular masses in choosing therapeutic plan. Biopsy of intraocular tumor is not recommended due to the risk of visual damage. We evaluated the usefulness of F-18-FDG PET imaging in diagnosing intraocular neoplasms. Materials and Methods: F-18-FDG PET scan was performed in 13 patients (15 lesions) suspected to have malignant intraocular tumors. There were 3 benign lesions (retinal detachment, choroidal effusion and hemorrhage) and 10 patients with 12 malignant lesions (3 melanomas, 7 retinoblastomas and 2 metastatic cancers). Regional eye images ($256{\times}256$ and $128{\times}128$ matrices) were obtained with or without attenuation correction. Whole body scan was also performed in eight patients (3 benign and 6 malignant lesions). Results: All malignant lesions were visualized while all benign lesions were not visualized. The mean peak standardized uptake value (SUV) of malignant lesions was $2.64{\pm}0.57g/ml$. There was no correlations between peak SUV and tumor volume. Two large malignant lesions ($> 1000 mm^3$) showed hot uptake on whole body scan. But two medium-sized lesions ($100-1000mm^3$) looked faint and two small ($<100mm^3$) lesions were not visualized. The images reconstructed with $256{\times}256$ matrix showed lesions more clearly than those with $128{\times}128$ matrix Conclusion: F-18-FDG PET scan is highly sensitivity in detecting malignant intraocular tumor For the evaluation of small-sized intraocular lesions, whole body scan is not appropriate because of low sensitivity. A regional scan with sufficient acquisition time is recommended for that purpose. Image reconstruction in matrix size of $256{\times}256$ produced clearer images than the ones in $128{\times}128$, but it does not affect the diagnostic sensitivity.