• Polymer(Korea)
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• v.24 no.2
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• pp.245-251
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• 2000

A blend system prepared from epoxy(EP) and polyurethane (PU) was investigated in terms of the contact angle and mechanical properties. The contents of EP/PU were varied within 100/0~100/60 phr in the presence of 20 phr DDM (4,4'-diamino diphenyl methane) as a curing agent for epoxy resin. Contact angle measurements were performed employing a Rame-Hart contact angle goniometer. Deionized water and diiodomethane were chosen as the testing liquids. In this work, Owens-Wendt and Wu's models using a geometric mean were studied to analyze the surface free energy of blend system. For the mechanical and toughening properties of the casting specimens, the critical stress Intensity factor ($K_{IC}$) and impact test were performed. Especially, the impact test was carried out at room and cryogenic temperatures. As a result, specific or polar component of the surface free energy of the blend system was largely influenced on the addition of the PU resulting in increasing the impact strength for the excellent low- temperature performance.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.2679-2683
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• 2015

Background: Phenethyl isothiocyanate (PEITC), the most comprehensively studied aromatic isothiocyanate, has been shown to act as an anti-cancer agent mainly through modulation of biotransformation enzymes responsible for metabolizing carcinogens in the human body. Humans are often exposed to carcinogenic factors, some of which through the diet, such as polycyclic aromatic hydrocarbon benzo[a]pyrene via the consumption of over-cooked meats. Inhibition of the enzymes responsible for the bioactivation of this carcinogen, for example CYP1A1, the major enzyme required for polycyclic aromatic hydrocarbons (PAHs) bioactivation, is recognized as a chemoprevention strategy. Objective: To evaluate the inhibitory effects of PEITC against benzo[a]pyrene-induced rise in rat liver CYP1A1 mRNA and apoprotein levels. Materials and Methods: Precision cut rat liver slices were treated with benzo[a]pyrene at 1 and $5{\mu}M$ in the presence of PEITC ($1-25{\mu}M$) for 24 hours, followed by determination of CYP1A1 mRNA and apoprotein levels using quantitative polymerase chain reaction and immunoblotting. Results: Findings revealed that PEITC inhibited benzo[a]pyrene-induced rise in rat liver CYP1A1 mRNA in a dose-dependent manner as well as the apoprotein levels of CYP1A. Conclusions: It was demonstrated that PEITC can directly inhibit the bioactivation of benzo[a]pyrene, indicating chemopreventive potential.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.523-528
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• 2005

Diblock copolymers with different poly($\varepsilon$-caprolactone) (PCL) block lengths were synthesized by ringopening polymerization of $\varepsilon$-caprolactone in the presence of monomethoxy poly(ethylene glycol) (mPEG-OH, MW 2000) as initiator. The self-aggregation behaviors of the diblock copolymer nanoparticle, prepared by the diafiltration method, were investigated by using $^1H$ NMR, dynamic light scattering (DLS), and fluorescence spectroscopy. The PEG-PCL block copolymers formed the nano-sized self-aggregate in an aqueous environment by intrsa- and/or intermolecular association between hydrophobic PCL chains. The critical aggregation concentrations (cac) of the block copolymer self-aggregate became lower with increasing hydrophobic PCL block length. On the other hand, reverse trends of mean hydrodynamic diameters were measured by DLS owing to the increasing bulkiness of the hydrophobic chains and hydrophobic interaction between the PCL microdomains. The hydrodynamic diameters of the block copolymer nanoparticles, measured by DLS, were in the range of 65-270 nm. Furthermore, the size of the nanoparticles was scarcely affected by the concentration of the block copolymers in the range of 0.125-5 mg/mL owing to the negligible interparticular aggregation between the self-aggregated nanoparticles. Considered with the fairly low cac and nanoparticle stability, the PEG-PCL nanoparticles can be considered a potential candidate for biomedical applications such as drug carrier or imaging agent.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9225-9232
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• 2014

Ensuring adherence to chemotherapy is important to prevent disease progression, prolong survival and sustain good quality of life. Capecitabine is a complex chemotherapeutic agent with many side effects that might affect patient adherence to treatment. This cross sectional study aimed to determine adherence to capecitabine and its contributing factors among cancer outpatients in Malaysia. One hundred and thirteen patients on single regime capecitabine were recruited from Hospital Sultan Ismail and Hospital Kuala Lumpur from October 2013 to March 2014. Adherence was determined based on adherence score using validated Medication Compliance Questionnaire. Patient socio-demographics, disease, and treatment characteristics were obtained from medical records. Satisfaction score was measured using the validated Patient Satisfaction with Healthcare questionnaire. The mean adherence score was 96.1% (standard deviation: 3.29%). The significant contributing factors of adherence to capecitabine were Malay ethnicity [${\beta}=1.3$; 95% confidence interval (CI): 0.21, 2.43; p value=0.020], being female [${\beta}=1.8$; 95%CI: 0.61, 2.99; p value=0.003]), satisfaction score [${\beta}=0.08$; 95%CI: 0.06, 1.46; p value=0.035], presence of nausea or vomiting [${\beta}=2.3$; 95%CI: 1.12, 3.48; p value <0.001] and other side effects [${\beta}=1.45$; 95%CI: 0.24, 2.65; p value=0.019]. Adherence to capecitabine was generally high in our local population. Attention should be given to non-Malay males and patients having nausea, vomiting or other side effects. Sufficient information, proactive assessment and appropriate management of side effects would improve patient satisfaction and thus create motivation to adhere to treatment plans.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2737-2742
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• 2011

Ring-opening metathesis polymerization (ROMP) of an ethyl-substituted tetracyclododecene (8-ethyltetracyclo[$4.4.0.1^{2,5}.1^{7,10}$] dodec-3-ene, Et-TCD) was carried out in the presence of a ternary catalyst system consisting of $WCl_6$, triisobutyl aluminium (iso$Bu_3Al$), and ethanol. The optimal molar ratio of Et-TCD/$WCl_3$/iso-$Bu_3Al$/ethanol was found as 500/1/3/2 at which the yield of ring-opened polymer was 100%. 1-Hexene was shown to be an effective molecular weight controlling agent for ROMP reaction of Et-TCD. The hydrogenation of the ring opened polymer (p-Et-TCD) was conducted successfully using Pd(5 wt %)/${\gamma}$-$Al_2O_3$ at $80^{\circ}C$ for 1 h. Chemical structures of p-Et-TCD and its hydrogenated product($H_2$-p-Et-TCD) were characterized using 2D NMR techniques ($^1H-^1H$ COSY and $^1H-^{13}C$ HSQC). The changes of physical properties such as thermal stability, glass transition temperature and light transmittance after the hydrogenation were also investigated using TGA, DSC, and UV.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.6 no.1
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• pp.3-9
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• 2020

Tetraiodothyroacetic acid (tetrac) is a derivative of thyroid hormone T₄ and causes anti-angiogenesis by blocking T₄ binding to integrin α_vβ₃. In this study, we synthesized [^99mTc]Tc-Cys-Asp-Gly(CDG)-tetrac and evaluated it in vitro as a tumor angiogenesis imaging ligand. The CDG was conjugated to tetrac as a chelator for technetium-99m labeling. The cold vial containing CDG-tetrac, sodium glucoheptonate, and reducing agent was completed under nitrogen-filled atmospheric glove bag. [^99mTc]Tc-CDG-tetrac was synthesized in quantitative yield by heating the cold vial with [^99mTc]TcO₄^- at 100℃ for 30 min. In vitro serum stability of [^99mTc]Tc-CDG-tetrac was measured by incubating the radioligand in 50% fetal bovine serum at 37℃ and analyzing the incubation mixture by radio-TLC, which showed high stability over 6 h (≥ 98%). Cell binding study was carried out by incubating [^99mTc]Tc-CDG-tetrac with human umbilical vein endothelial (HUVE) cells at 37℃ for 6 h. The cell binding of the radioligand increased from 100% at 0.5 h to 293.7% at 6 h in a time-dependent manner. For blocking study, the cells were incubated with the radioligand in the presence of either tetrac (20 μM) or cRGDyK (20 μM) at 37℃ for 4 h. The results demonstrated that the cell binding of the radioligand was inhibited by tetrac (19.1%) or cRGDyK (35.6%), indicating specific binding of the radioligand to integrin α_vβ₃. Thus, this study suggests that [^99mTc]Tc-CDG-tetrac may be a potential radioligand for tumor angiogenesis imaging.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1332-1343
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• 2008

The purpose of this study was to investigate the feasibility of using sedimentation calcium carbonate production based on microorganism activities in the strength manifestation of various soil conditions including ground. For analysis and comparison of microbial cementation soil's strength, unconfined compression test was executed by each content of soil(S), water(W), microorganism(B), microorganism and deposit (BF), microorganism, admixture and deposit(BCF) at specimen. The result, the strength of SB(soil+microorganism) and SBF(soil+microorganism+deposit) increased about 8%, 15% than SW(soil+water). Also, initial strength increased. But the strength of SBC(soil+microorganism+admixture) and SBCF(soil+microorganism+deposit+admixture) increased about 71%, 115% than SW(soil+water). The results of the SEM analysis, leading to the formation of an adhesive substance layers at the surface and resulting in firm particle configuration. The XRD examination of the sediment resulting from the reaction between the microorganism and the deposit control agent confirmed the presence of a type of calcium carbonate ($CaCo_3$) vaterite, which affects soil strength formation, as well as sodium silicate, silicides and so forth. This indicates that microorganism plays an important role in the production of carbonate ($CaCo_3$), sodium silicate and silicides. It affects to revelation of ground strength.

• Journal of Environmental Health Sciences
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• v.38 no.1
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• pp.57-65
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• 2012

Objectives: For our survey of the incidence of norovirus infections and the genogroup distribution of norovirus in Seoul, Republic of Korea, we evaluated through regular surveillance the prevalence of norovirus infections in patients with acute gastroenteritis occurring in Seoul from January 2007 to July 2011. Methods: For norovirus detection, we conducted epidemiological analyses on the basis of the junction of ORF1 and ORF2 (approximately 314 bp). 11,202 fecal specimens were collected from patients in Seoul with acute gastroenteritis between January 2007 and July 2011 and then tested for the presence of NoV via reverse transcription (RT) - polymerase chain reaction (PCR). Results: 16.6% (1,861/11,202) of the fecal specimens were determined to be positive for noroviruses. The incidences of norovirus infection in Seoul in the case of acute gastroenteritis with regular surveillance were 28.0% in 2007, 14.6% in 2008, 9.1% in 2009, 14.1% in 2010, and 12.9% in 2011, which shows that noroviruses constituted a major causative agent of acute gastroenteritis. Also, the incidence of noroviral infection in patients with acute gastroenteritis increased after the large-scale new influenza in 2009. Conclusions: The genetic characteristics of norovirus and the epidemiologic patterns of a viral pathogen in acute gastroenteritis patients may provide potentially effective data for epidemiological studies in Seoul, Korea.

• Journal of Environmental Science International
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• v.21 no.12
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• pp.1435-1447
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• 2012

The present study was conducted to determine the effect of hexaconazole (HEX), a triazole fungicide, on the growth, yield, photosynthetic response and antioxidant potential in cucumber (Cucumis sativus L.) plants subjected to UV-B stress. UV-B radiation and HEX were applied separately or in combination to cucumber seedlings. The growth parameters were significantly reduced under UV-B treatment, however, this growth inhibition was less in HEX treated plants. HEX caused noticeable changes in plant morphology such as reduced shoot length and leaf area, and increased leaf thickness. HEX was quite persistent in inhibiting shoot growth by causing a reduction in shoot fresh and dry weight. HEX noticeably recovered the UV-B induced inhibition of biomass production. Significant accumutation in anthocyanin and flavonoid pigments in the leaves occurred as a result of HEX or UV-B treatments. HEX permitted the survival of more green leaf tissue preventing chlorophyll content reduction and higher quantum yield for photosystemII under UV-B exposure. HEX treatment induced a transient rise in ABA levels in the leaves, and combined application of HEX and UV-B showed a significant enhancement of ABA content which activates $H_2O_2$ generation. UV-B exposure induced accumulation of $H_2O_2$ in the leaves, while HEX prevented UV-B induced increase in $H_2O_2$, indicating that HEX serves as an antioxidant agent able to scavenge $H_2O$ to protect cells from oxidative damage. An increase in the ascorbic acid was observed in the HEX treated cucumber leaves affecting many enzyme activities by removing $H_2O_2$ during photosynthetic processes. The activities of antioxidant enzymes including catalase(CAT), ascorbate peroxidase(APX), superoxide dismutase(SOD) and peroxidase(POD) in the leaves in the presence of HEX under UV-B stress were higher than those under UV-B stress alone. These findings suggest that HEX may participate in the enhanced tolerance to oxidative stress. From these results it can be concluded that HEX moderately ameliolate the effect of UV-B stress in cucumber by improving the components of antioxidant defense system.

• Journal of Acupuncture Research
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• v.23 no.6
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• pp.103-115
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• 2006

Objectives : Rheumatoid arthritis(RA) is a systemic & a chronic inflammatory autoimmune disease . A chronic , locally destructive inflammmatory reaction in human is examplified by the synovitis present in some connective tissue disorder. The presence of a number of cytokines, $TNF-{\alpha}$, iNOS & expression of nitric oxide, NF-kB p65 activation implies an important role of cellular immune response in RA inflammatory reaction. This study was designed to evaluate on the effects of the Homnis Placenta herbal acupuncture on EX-LE201 & ST 35 reducing expression of LPS-induced arthritis model in mice. Materials and Methods : Homnis Placenta herbal acupuncture was inserted into 10 rats induced rheumatoid arthritis. The acupunctures were injected into the EX-LE201 and ST35 points. Such indexes were measured the inhibition of inducible nitric oxide synthase(iNOS) expression, nitric oxide(NO) production in vitro experiment and Tumor Necrosis $Factor-{\alpha}(TNF-{\alpha})$ & Nuclear Factor kappa $B(NF-{\kappa}B)$ p65 activation, synovial hyperplasia, angiogenesis and fibrosis in synovial membrane of knee joint of mice in vivo experiment. Results : 1.Homnis Placenta Herbal acupuncture inhibited iNOS mRNA and NO in RAW 264.7 cell of LPS-induced rheumatoid arthritis in a dose dependent manner. 2.Homnis Placenta Herbal acupuncture also showed significant inhibition of $TNF-{\alpha}$ & $NF-{\kappa}B$ p65, activation, synovial hyperplasia, angiogenesis and fibrosis in synovial membrane of knee joint of mice. Conclusion : These results suggest that Homnis Placenta Herbal acupuncture has an therapeutic effects on LPS induced-rheumatoid arthritis by inhibiting $TNF-{\alpha}$ activation.