• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.86-89
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• 2011

Purpose: The KOTRON-13 cyclotron was developed in South Korea and was introduced to regional cyclotron centers to produce short-lifetime medical radioisotopes. However, this cyclotron has limited capacity to produce carbon-11 isotope so far. We herein study how to develop and optimize an effective carbon-11 target system in the KOTRON-13 cyclotron by changing cooling system, combing with fluorine-18 target and evaluating beam currents. Materials and Method: To develop the optimal carbon-11 target and an effective cooling system, we designed the carbon-11 target system by Stopping and Range of Ions in Matter (SRIM) simulation program and considered the cavity pressure during irradiation at target grid. In this investigation, we evaluated the yield of carbon-11 production at different beam currents and the stability of the operation of the KOTRON-13 cyclotron. Results: The production of carbon-11 was enhanced from about 1.700 mCi ($50{\mu}A$) to 2,000 mCi ($60{\mu}A$) on the carbon-11 target which developed by seoul national university bundang hospital (SNUBH) and Samyoung Unitech. Additionally, the cooling condition was showed stable to produce carbon-11 under high beam current. Conclude: The carbon-11 target system of the KOTRON-13 cyclotron was successfully developed and improved carbon-11 production. Consequently, the operation of carbon-11 target system was highly effective and stable compare with other commercial cyclotrons. Our results are believed that this optimal carbon-11 target system will be helpful for the routine carbon-11 production in the KOTRON-13 cyclotron.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.730-738
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• 1992

Filtration characteristics according to membrane materials were studied In the ultrafiltration of anaerobic digestion broth as a post treatment method. A series of resistances for different membranes were quantitatively assessed on the basis of the resistance-in-series model. Flux behavior observed with the digestion broth was irrelevant to initial water permeabilities of each membrane. The fluoro polymer membrane showed the most significant improvement of flux with increase of cross-flow velocity, which suggests that the cake layer formed on this membrane is more weakly attached to the membrane surface than those on the other membranes. Flux reduction during longtime running was attrib-used to the polarization layer resistance ($R_p$) as well as the fouling layer resistance($R_f$). Continuous increase of $R_p$ may reflect the variation in the characteristics of cake layers, which could result from size, shape, and structure changes due to lysis and growth of biomass. Hydrophilic cellulosic membrane had a much lower fouling tendency than hydrophobic polysulfone membrane. The depressurization method induced a small increase in flux of $5-10L/m^2/h$. During washing and cleaning, filtrability of each membrane was rapidly recovered within 15 minutes until a stationary value was reached.

• Applied Biological Chemistry
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• v.43 no.1
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• pp.52-56
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• 2000

The influence of the 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-phenyl- propionamide derivatives on the herbicide activities against rice plant with pre-emergence and post-emergence in down land were examined and the structure activity relationship (SAR) were analyzed by Free-Wilson and Hansch method. In pre-emergence, the SAR approach is shown that the optimal, $({\pi})_{opt}=0.91$, hydrophobicity with electron donating effect of the ortho substituted mono substituents and 2,3,4-substituted three substituents were found to be contribute the herbicidal activity. Whereas, in post-emergence, the optimal, ({\pi})_{opt}=0.50$, hydrophobicity with electron withdrawing effect of meta substituted mono subsituents and 2,3-substituted two substituents were found to be contribute the herbicide activity. The herbicide activities with post-emergence more increase than that of pre-emergence. It is assumed from the SAR equations that the 2-methyl-3-methoxy-4-cyano group substituent is selected as the most lowest herbicide activity against rice plant with post-emergence in green house. The hydrolysis reaction was proceeded through nucleophilic addition-elimination (Ad_{Nu-E})$ with the orbital control between LUMO of substrate and HOMO of water molecule. And molecular electrostatic potential (MEP) of none (H) substituent was discussed.

• Journal of Ginseng Research
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• v.41 no.2
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• pp.134-143
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• 2017

Background: The prevalence of allergic inflammatory diseases such as atopic dermatitis (AD), asthma, and allergic rhinitis worldwide has increased and complete recovery is difficult. Korean Red Ginseng, which is the heat-processed root of Panax ginseng Meyer, is widely and frequently used as a traditional medicine in East Asia. In this study, we investigated whether Korean Red Ginseng water extract (RGE) regulates the expression of proinflammatory cytokines and chemokines via the mitogen-activated protein kinases (MAPKs)/nuclear factor kappa B ($NF-{\kappa}B$) pathway in allergic inflammation. Methods: Compound 48/80-induced anaphylactic shock and 1-fluoro-2,4-dinitrobenzene (DNFB)-induced AD-like skin lesion mice models were used to investigate the antiallergic effects of RGE. Human keratinocytes (HaCaT cells) and human mast cells (HMC-1) were also used to clarify the effects of RGE on the expression of proinflammatory cytokines and chemokines. Results: Anaphylactic shock and DNFB-induced AD-like skin lesions were attenuated by RGE administration through reduction of serum immunoglobulin E (IgE) and interleukin (IL)-6 levels in mouse models. RGE also reduced the production of proinflammatory cytokines including $IL-1{\beta}$, IL-6, and IL-8, and expression of chemokines such as IL-8, thymus and activation-regulated chemokine (TARC), and macrophage-derived chemokine (MDC) in HaCaT cells. Additionally, RGE decreased the release of tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), $IL-1{\beta}$, IL-6, and IL-8 as well as expressions of chemokines including macro-phage inflammatory protein $(MIP)-1{\alpha}$, $MIP-1{\beta}$, regulated on activation, normal T cell expressed and secreted (RANTES), monocyte chemoattractant protein (MCP)-1, and IL-8 in HMC-1 cells. Furthermore, our data demonstrated that these inhibitory effects occurred through blockage of the MAPK and $NF-{\kappa}B$ pathway. Conclusion: RGE may be a useful therapeutic agent for the treatment of allergic inflammatory diseases such as AD-like dermatitis.

• Tuberculosis and Respiratory Diseases
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• v.55 no.3
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• pp.280-286
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• 2003

Background : $^{99m}Technetium$ methylene diphosphonates($^{99m}Tc$ MDP) bone scintigraphy is current method of choice for the detection of bone metastases, but whole body $^{18}F$-fluoro-deoxy-D-glucose positron emission tomography($^{18}FDG$ PET) offers superior spatial resolution and improved sensitivity. So we compared whole body $^{18}FDG$ PET with $^{99m}Tc$ MDP bone scintigraphy in patients with skeletal metastases from lung cancer. Patients and Methods : Ninety-two patients with lung cancer taken $^{18}FDG$ PET together with a $^{99m}Tc$ MDP bone scintigraphy within 1 month between March 2000 and March 2003 were investigated retrospectively. Results : The sensitivity, specificity and accuracy of the $^{99m}Tc$ MDP bone scintigraphy versus $^{18}FDG$ PET for the detection of bone metastases in lung cancers were 59% vs 82%, 71% vs 94%, and 68% vs 91%, respectively. In the diagnosis of bone metastases from lung cancer, $^{18}FDG$ PET was statistically superior to $^{99m}Tc$ MDP bone scintigraphy in its specificity and accuracy(p<0.0001). Conclusions : Whole body $^{18}FDG$ PET may be useful in detecting bone metastases among patients with lung cancer.

• Polymer(Korea)
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• v.33 no.6
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• pp.537-543
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• 2009

The direct fluorination of polymers is a heterogeneous reaction using the mixture of $F_2$ and inert gas. In general, the resulting fluorinated polymers have good barrier property chemical stability similar to those of the fluoro-polymers, and could be prepared from the simple process. In this study, the polysulfone dense films were surface fluorinated using the direct fluorination technique and gas permeability and selectivity of the prepared membranes were measured with varying both $F_2$ concentration and reaction time. The introduction of $F_2$ was confirmed by X-ray photoelectron spectroscopy (XPS), water contact angles, and atomic force microscopy (AFM). As the $F_2$ increased, the permeability decreased while the selectivities for $O_2$, $CO_2$, and He gases relative to $N_2$ increased.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.6
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• pp.566-569
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• 2007

Purpose: Analysis of volatile organic solvents in 2-deoxy-2-$[^{18}F]$ fluoro-D-glucose ($[^{18}F]$FDG) preparations was performed by gas chromatography (GC), in accordance with USP. Materials and Methods: Analyses were carried out on a Hewlett-Packard 6890 gas chromatography equipped with an FID. Results: We determined the amounts of ethanol and acetonitrile on every batch of our routine $[^{18}F]$FDG preparations, ranging between 5000 ppm and 100 ppm. In our routine preparation of $[^{18}F]$FDG, the amount of acetonitrile and ethanol in the final product were well below the maximum allowable limit described in the USP. Conclusion: Our $[^{18}F]$FDG preparations were in accordance with the suggested USP maximum allowable levels of the quality control analysis of volatile organic compounds.

• Radiation Oncology Journal
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• v.35 no.4
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• pp.306-316
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• 2017

Purpose: To investigate the predictive role of maximum standardized uptake value ($SUV_{max}$) of 2-[$^{18}F$]fluoro-2-deoxy-D-glucose($^{18}F-FDG$) positron emission tomography/computed tomography (PET/CT) in nasopharyngeal cancer patients treated with intensity-modulated radiotherapy (IMRT). Materials and Methods: Between October 2006 and April 2016, 53 patients were treated with IMRT in two institutions and their PET/CT at the time of diagnosis was reviewed. The $SUV_{max}$ of their nasopharyngeal lesions and metastatic lymph nodes (LN) was recorded. IMRT was delivered using helical tomotherapy. All patients except for one were treated with concurrent chemoradiation therapy (CCRT). Correlations between $SUV_{max}$ and patients' survival and recurrence were analyzed. Results: At a median follow-up time of 31.5 months (range, 3.4 to 98.7 months), the 3-year overall survival (OS) and disease-free survival (DFS) rates were 83.2% and 77.5%, respectively. In univariate analysis, patients with a higher nodal pre-treatment $SUV_{max}$ (${\geq}13.4$) demonstrated significantly lower 3-year OS (93.1% vs. 55.5%; p = 0.003), DFS (92.7% vs. 38.5%; p < 0.001), locoregional recurrence-free survival (100% vs. 50.5%; p < 0.001), and distant metastasis-free survival (100% vs. 69.2%; p = 0.004), respectively. In multivariate analysis, high pre-treatment nodal $SUV_{max}$ (${\geq}13.4$) was a negative prognostic factor for OS (hazard ratio [HR], 7.799; 95% confidence interval [CI], 1.506-40.397; p = 0.014) and DFS (HR, 9.392; 95% CI, 1.989-44.339; p = 0.005). Conclusions: High pre-treatment nodal $SUV_{max}$ was an independent prognosticator of survival and disease progression in nasopharyngeal carcinoma patients treated with IMRT in our cohort. Therefore, nodal $SUV_{max}$ may provide important information for identifying patients who require more aggressive treatment.

• Korean Journal of Head & Neck Oncology
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• v.19 no.1
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• pp.58-62
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• 2003

Purpose: To evaluate the efficacy of positron emission tomography with 2-[F-18] fluoro-2-deoxy-D-glucose in discrimination of response in the nasopharyngeal carcinoma patients who treated with radiotherapy. Methods and Materials: Twenty-four patients who underwent FDG-PET scan before and after radiotherapy for no disseminated head and neck carcinoma at the Asan Medical Center between August 2001 and September 2002 were evaluate by prospective analysis. First FDG-PET scan performed before radiotherapy within 1 month, and second FDG-PET scan performed 1 month after radiotherapy. FDG-PET images were analyzed by standard uptake value (SUV). Follow-up period was more than 6 months. Results: The pretreatment SUV was 3.4-14.0 (median: 6.0) and posttreatment SUV was ground level-7.7 (median: 2.0). The overall sensitivity and specicity of FDG-PET to evaluate residual tumors in the nasopharyngeal carcinoma patients were 94% and 94%. Conclusion: FDG-PET is effective in evaluation of radiation response in the nasopharyngeal carcinoma. We think that the timing of one month after finished radiotherapy FDG-PET scan was not too fast to evaluation of radiation response.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.467-472
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• 2011

This study investigated illite/polypropylene (PP) composite filament formation via melt-spinning and evaluated their physical properties to prepare functional fibers using natural materials. When composite filaments were formed, the composite filaments exhibited smaller fiber diameters compared to that of neat PP filament because of the lubricant effect of illite induced by its layered structure. Moreover, fluorination effect increased interfacial affinity and dispersion in the polymer, resulting in smaller diameter of fluorinated illite/PP composite filament, which was 2/3 of the neat PP filament diameter. Addition of raw and fluorinated illite improved thermal stability of illite/PP composite filament. Raw illite/PP composite filament cannot be used for a practical application, because it broke during drawing process, whereas the fluorinated illite/PP composite filament can be used for a practical application, because it exhibited similar tensile strength of the neat PP filament and 50% increased modulus. Even with improved illite/PP interfacial affinity and illite dispersion in the polymer, illite/PP composite filament formed microcomposite, because non-expandable illite had strongly bound layers, resulting in only a little illite exfoliation and PP intercalation into illite.