• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.3
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• pp.306-313
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• 2017

Purple bamboo salt (PuBS) is commonly used as a medicinal food in Korea and has beneficial potentials such as antioxidant and anti-inflammatory effects. Rubus coreanus is called Bokbunja, which is used as a traditional medicine for treating asthma, impotence, and allergic diseases in Korea. The aim of present study was to investigate the immunostimulatory effect of PuBS composed with Rubus coreanus (PuBS-R). We performed comparative analysis between PuBS and PuBS-R in Raw264.7 cells, which is a mouse macrophage cell line, and peritoneal macrophages isolated primarily from the mouse peritoneal cavity. We evaluated cytotoxicity and the immune cytokine response in PuBS- and PuBS-R-treated cells. Both PuBS and PuBS-R did not have any cytotoxicity in Raw264.7 cells up to $500{\mu}g/mL$. Gene and protein levels of immune cytokines such as tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), $interferon-{\gamma}$ ($IFN-{\gamma}$), interleukin (IL)-10, and IL-12 were significantly elevated by PuBS-R more than PuBS in Raw264.7 cells. Moreover, we evaluated the immunostimulatory effects of PuBS-R on mouse primary peritoneal macrophages. Protein levels of inducible nitric oxide synthase, $TNF-{\alpha}$, $IFN-{\gamma}$, IL-10, and IL-12 were significantly higher in PuBS-R-treated peritoneal macrophages than PuBS-treated peritoneal macrophages. These results suggest the potential immunostimulatory effect of PuBS-R for immunity against harmful infection.

• Membrane Journal
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• v.14 no.2
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• pp.157-165
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• 2004

PU/PDMS(Poly urethane/poly(dimethylsiloxane ) membranes were prepared to enhance chemical resistance over VOCs from 4,4'-diphenylmethane diisocyanate (MDI), poly(dimethylsiloxane) (PDHS). Swelling characteristics and vapor permeation performance of toluene, 1,2-dichloroethane, hexane through PU/PDMS membrane with various feed VOCs concentration were investigated. Swelling ratio of VOCs showed tendency of Toluene > 1,2-dichloroethane > hexane. Fiux of toluene and 1,2-dichloroethane increased with increasing fled concentration while the flux of hexane maintained with increasing feed. VOCs concentration in permeate maintained 50 wt% oi concentration due to high affinity of PU/PDHS membranes to VOCs.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.639-643
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• 1999

Interpenetrating polymer networks(IPNs) composed of castor oil(CO) polyurethane(PU) and epoxy resin were prepared by the simultaneous polymerization technique. Two types of PU were prepared using 1,4-butanediol(BD) and BD/trimethylolpropane(TMP) as a chain extending agent and crosslinking agent. The PU/epoxy based on BD as a chain extending agent showed more shift in the damping peak than PU/epoxy based on BD/TMP as the PU content was increased. BDPU/epoxy simultaneous interpenetrating polymer networks(SINs) had a better compatibility than BD/TMP-PU/epoxy SINs. For both systems, it was postulated that unique network formation of PU/epoxy SINs as a chain extending agent and crosslinking agent had occurred to a significant extent of phase mixing. The types of chain extender in the PU were found to be an important factor in determining the phase mixing of the IPNs. When the BD/TMP-PU reaction was faster than epoxy network, the extent of phase mixing was retarded by decreasing entanglement of networks. It was found that both PU/epoxy SINs provided enhanced flexural properties and fracture toughness, fracture surfaces of BDPU/epoxy and BD/TMP-PU/epoxy SINs showed the localized shear deformation and generation of stress whitening associated with the cavitation.

• Journal of Biomedical Engineering Research
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• v.15 no.1
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• pp.19-26
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• 1994

Sulfonated poly (ethyleneoxide)-grafted polyurethane (PU-PEO-$SO_3$) prepared by bulk modification was coated on a blood sac for electrohydraulic left ventricular assist device (ELVAD) implanted in dogs and its in vivo blood compatibility on shear stress was studied as compared with untreated Po. The effect of the wall shear stress on the protein adsorption unlike platelet adhesion is dependent on the surface characteristics of the material, although less proteins seem to be adsorbed in the region of the high shear stress. The thickness of total proteins adsorbed on PU-PEO-SOJ (400 ${\AA}$) by trans¬mission electron microscopy(TEM) was considerably lower than that of untreated PU(l,000~1,600 ${\AA}$), but PU-PEO-$SO_3$ showed high albumin adsorption, low fibrinogen and IgG adsorption, and low platelet adhesion as compared with untreated PU, suggesting that PU-PEO-$SO_3$ is more in vivo blood compatible. Therefore, it appears that such a blood compatible PU-PEO-$SO_3$ is useful for blood contacting biomaterials including artificial organs.

• Biomedical Science Letters
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• v.29 no.2
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• pp.58-65
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• 2023

Pu-erh tea, a popular and traditional Chinese tea, possesses various health-promoting effects, including inhibiting tumor cell progression and preventing type II diabetes and neurodegenerative disorders. However, the precise anti-inflammatory mechanisms are not well understood. In present study, we elucidated the anti-inflammatory mechanism of Pu-erh tea in lipopolysaccharide (LPS)-activated RAW264.7 cells. We explored the effects of Pu-erh tea on the levels of inflammatory-related genes, including inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and prostaglandin E₂ (PGE₂) in LPS-activated RAW264.7 cells. Moreover, we investigated its regulatory effects on nuclear factor-kappa B (NF)-κB and hypoxia-inducible-factor (HIF)-1α activation. The findings of this study demonstrated that Pu-erh tea inhibited the LPS-increased inflammatory cytokines and PGE₂ release, as well as COX-2 and iNOS expression. Moreover, we confirmed that the anti-inflammatory mechanism of Pu-erh tea occurs via the inhibition of NF-κB and HIF-1α activation. Conclusively, these findings provide experimental evidence that Pu-erh tea may be useful candidate in the treatment of inflammatory-related diseases.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.131-140
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• 2017

Uniform nanofibers of polyurethane with different content of Juniperus Chinensis extracts (JCE) were successfully prepared by the electrospinning method. We investigated physiochemical properties of prepared compound nanoweb according to various concentrations of Juniperus Chinensis extracts using a Fourier transform infrared (FT-IR) spectrometer, X-ray diffractometer (XRD), thermogravimeter (TGA), and differential scanning calorimeter (DSC). The antibacterial activity of the JCE loaded PU nanofiber was conducted using the disk diffusion test against Gram-positive and Gram-negative bacteria. JCE was induced in the infrared spectra in the absorption band of PU/JCE nanowebs at $3,300cm^{-1}$, $2,960cm^{-1}$, $1,400-1,600cm^{-1}$, and $1,050cm^{-1}$. Thermal stability decreased with increasing JCE content in the PU/JCE nanowebs. The DSC curve of the PU nanoweb shows an endotherm peak at $420^{\circ}C$; in addition, the peak also became smaller and broader with increasing JCE content. The diffraction intensities of PU observed at 2 theta of $20^{\circ}$ decreased with the increasing amount of JCE in the compound nanoweb. In addition, the crystal intensities of the compound nanowebs also decreased along with the JCE content. Structural analysis indicates that JCE and PU are miscible. Juniperus Chinensis incorporated PU nanofibers demonstrated excellent antibacterial properties against both Gram-positive and Gram-negative bacteria.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.350-351
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• 2003

Polyurethane은 물리적, 화학적 성질이 매우 다른 두 segment(hard/soft)로 이루어진 block copolymer로서 hard segment의 화학적 구조가 hard segment의 packing정도에 영향을 미쳐, PU의 미세상분리 현상을 결정하며 결과적으로 PU의 물리적 성질에 큰 영향을 미치게 된다$^1$. 본 연구에서는 hard segment의 packing을 향상시켜 PU은 열적 기계적 특성을 향상시키기 위하여 방향족환으로 구성되어 있어 aromatic diol의 일종인 hydroxyquinone-di-(beta-hydroxyl)ether(HQEE)를 chain extender로 사용하여 PU를 합성하였다. (중략)

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.6
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• pp.800-808
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• 1999

The demand for PU coated synthetic leather is increasing as a high fashion material. But it has some faults of water vapor permeability surface tacky property and static electricity. Therefore the purpose of this study was the produce of PU coated fabric added collagen with hydrophilic property and soft touch. In the PU coated fabric water vapor permeability water vaper absorption and frictional electronic voltage were investigated surface bending and compression properties were also examined by the use of KES-FB System. The followings were the results of this study. 1. There was no Cr in the collagen so that Cr was not treated in the collagen. 2. The surface and cross sectional layer of PU coated fabric with collagen were highly developed by micro porous structure. 3. The water vapor permeability of PU coated fabric was increased as collagen concentration increased. 4. The water vapor absorption of PU coated fabric was increased as collagen concentration increased. 5. The frictional electronic voltage of PU coated fabric was decreased in accordance with the increase of collagen concentration. Especially it effectively decreased by the use of only 5% collagen concentration. 6,. The bending and compression properties of PU coated fabric were increased in accordance with the increase of collagen concentration so that it became stiff. 7. The Value of MIU, SMD was decreased in accordance with the increase of collagen concentration so that the PU coated fabric became smooth.

• Nuclear Engineering and Technology
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• v.50 no.1
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• pp.140-144
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• 2018

Isotopic analyses of plutonium and low-enriched uranium mixtures with particle sizes of $0.6-3.3{\mu}m$ were performed using thermal ionization mass spectrometry with a continuous heating method to verify its effectiveness for the accurate analysis of minor isotopes without sample pretreatment. The mixed particles used in this study were prepared from a mixed solution of plutonium (SRM 947) and uranium (U010, $^{235}U$ 1% enriched) reference materials. The isotope ratios for plutonium in the individual mixed particles, including $^{238}Pu/^{239}Pu$, $^{241}Pu/^{239}Pu$ as well as $^{240}Pu/^{239}Pu$, and $^{242}Pu/^{239}Pu$, were in good agreement with the certified values despite the isobaric interference of $^{238}U$ and $^{241}Am$. The isotope ratios for uranium in the mixed particles also agreed well with the certified values within the range of error. However, the isotope ratios for minor isotopes, such as $^{234}U$ and $^{236}U$, in the particles with diameters of less than approximately $1.8{\mu}m$ could not be measured because numbers of $^{234}U$ and $^{236}U$ atoms in analyzed particles are too low. These results indicate that thermal ionization mass spectrometry with a continuous heating method is applicable for the analysis of trace amounts of plutonium isotopes, including $^{238}Pu$ and $^{241}Pu$, despite the presence of the respective isobars $^{238}U$ and $^{241}Am$ in the microsamples.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.222-225
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• 2013

무선 네트워크 환경에서 스펙트럼 자원을 효율적으로 활용할 수 있는 무선 인지 (Cognitive Radio, CR) 중 기지국이나 접속점과 같은 중앙 제어장치가 없는 분산형 무선 인지 네트워크 (Distributed Cognitive Radio Network, DCRN)에서는 부 사용자 (Secondary User, SU)들의 하드웨어적 한계로 인해 주 사용자 (Primary User, PU)들에게 인가된 스펙트럼의 모든 정보를 알 수 없다. 이를 극복하기 위해 SU들은 협력적 스펙트럼 감지 (Cooperative Spectrum Sensing)를 통하여 지역적인 스펙트럼 정보를 서로 교환하여 전체 스펙트럼의 정보를 파악한다. 본 논문은 효율적인 협력적 스펙트럼 감지를 위하여 PU 채널 상태의 비율을 사용한 정책 기반 감지 채널 선택 방법인 비율 기반 감지 정책 (Proportion-based Sensing Policy, PSP)을 제안한다. 각 SU가 PU의 채널 사용을 감지하고 PU 채널들의 idle 상태의 비율을 계산하고, 이 결과를 바탕으로 감지하는 PU 채널 변경 시, 높은 idle 비율을 갖는 PU 채널을 우선적으로 선택하여 감지되는 PU 상태가 idle 일 확률을 높여 효율적인 채널 감지를 가능하게 한다. 시뮬레이션 결과를 통하여 기존에 제안된 채널 감지 정책보다 비율 기반의 채널 감지 정책이 효율적으로 PU 채널들을 감지하는 것을 알 수 있다.