• Title/Summary/Keyword: Oxygen permeability

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Preparation and Physical Properties of Silicone Hydrogel Ophthalmic Lens Containing Hydrophilic Monomer

  • Lee, Min-Jae;Sung, A-Young
    • Journal of the Korean Chemical Society
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    • v.60 no.4
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    • pp.261-266
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    • 2016
  • The major physical characteristics of macromolecules used in silicone hydrogel ophthalmic lenses include optical transmittance, oxygen permeability, water content, and refractive index. For the preparation of highly functional silicone hydrogel lens materials, two silicone monomers were used in the presence of 2-hydroxyethyl methacrylate (HEMA) and hydroxypropyl methacrylate (HPMA). The samples containing HEMA and HPMA had oxygen transmissibility (Dk) values in the range of 73.38–50.98 × 10-11 (cm2/s) (mLO2/mL×mmHg) and 71.94–42.80 × 10-11 (cm2/s) (mLO2/mL×mmHg), respectively. Furthermore, the water contents of samples containing HEMA and HPMA were in the range of 32.73–34.67% and 31.94–33.74%, respectively, and the refractive indices were in the range of 1.4348–1.4364 and 1.4385–1.4407, respectively. Thus, silicone monomers containing HEMA and HPMA are expected to be useful for fabricating high-oxygen-permeability silicon hydrogel ophthalmic lenses.

Synergistic Effect of Oxygen Pressure and Sonophoresis for Skin Permeability (산소 압력과 초음파를 이용한 피부투과도 증대에 관한 연구)

  • 차민석;이철규;윤영로;이원수
    • Journal of Biomedical Engineering Research
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    • v.23 no.3
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    • pp.189-196
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    • 2002
  • Transdermal drug delivery offers an alternative method to the conventional oral and injection delivery method. Its advantages include its ability to deliver drugs directly into systemic circulation. However, there have been restrictions in its application to deliver drugs because of the skin's barrier function. In this study, we try to combine a Sonophoresis and oxygen Pressure method in order to increase the Permeability of the skin. we used water as the compound and by utilizing the skin impedance method. we measured the hydration Permeability of skin Ultrasound was applied using a sonicator(Solcare-U1000. Solco, Korea) operating at a frequency of 1MHz. oxygen Pressure was applied using a compressor(Oxyjet-Pointer, Nora Bode. Germany) operating at a pressure of 2Bar/cm2. Experiment was performed in vivo for 42 People. We divided the subjects into four smaller groups. A different transdermal drug delivery method was applied for each group on the back of their hand. We measured the skin impedance variations on the hand. during a 20-minute time Period. The control group did not show any significant increase or variation of skin impedance to water. In comparison to the control group(Passive diffusion) the hydration Permeability of the ultrasound group and the oxygen Pressure group was approximately 25 and 30 times higher consecutively. Futhermore, the hydration permeability of the combination of ultrasound and oxygen Pressure group was about 70-fold higher in comparison to the control group(passive diffusion) . The results reveal that a combination of ultrasound and oxygen Pressure will significantly enhance transdermal water transport compared when only one of them is used.

Oxygen Permeability and Resistance to Carbon Dioxide of SrCo0.8Fe0.1Nb0.1O3-δ Ceramic Membrane (SrCo0.8Fe0.1Nb0.1O3-δ 세라믹 분리막의 산소투과 특성 및 이산화탄소에 대한 내성)

  • Kim, Eun Ju;Park, Se Hyoung;Park, Jung Hoon;Baek, Il Hyun
    • Membrane Journal
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    • v.25 no.5
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    • pp.415-421
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    • 2015
  • $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ oxide was synthesized by solid state reaction method. Dense ceramic membrane was prepared using as-prepared powder by pressing and sintering at $1250^{\circ}C$. XRD result of membrane showed single perovskite structure. The oxygen permeability were measured under 0.21 atm of oxygen partial pressure ($P_{O_2}$) and between 800 and $950^{\circ}C$. The oxygen permeation flux of $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ membrane was increased with the increasing temperature. The maximum oxygen permeation flux was $1.839mL/min{\cdot}cm^2$ at $950^{\circ}C$. Long period permeability experiment was carried out to confirm the phase stability and $CO_2$-tolerance of membrane containing Nb in the condition of air with $CO_2$ (500 ppm) as feed stream at $900^{\circ}C$. The phase stability and $CO_2$-tolerance of $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ were investigated by XRD and TG analysis. The result of $SrCo_{0.8}Fe_{0.1}Nb_{0.1}O_{3-{\delta}}$ which exposed carbon dioxide for 100 hours indicated 8wt% of $SrCO_3$. But it was known that the level of $SrCO_3$ production dose not have a significant effect on oxygen permeability.

Differential Effect of Harmalol and Deprenyl on Dopamine-Induced Mitochondrial Membrane Permeability Change in PC12 Cells

  • Lee, Chung-Soo
    • Biomolecules & Therapeutics
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    • v.12 no.1
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    • pp.9-18
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    • 2004
  • Opening of the mitochondrial permeability transition pore has been recognized to be involved in cell death. The present study investigated the effect of ${\beta}$-carbolines (harmaline and harmalol) and deprenyl on the dopamine-induced change in the mitochondrial membrane permeability and cell death in differentiated PC12 cells. Cell death due to 250 4{\mu}$M dopamine was inhibited by caspase inhibitors (z-IETD.fmk, z-LEHD.fmk and z-DQMD.fmk) and antioxidants (N-acetylcysteine, ascorbate, superoxide dismutase, catalase and carboxy-PTIO). ${\beta}$-Carbolines prevented the dopamine-induced cell death in PCl2 cells, while deprenyl did not inhibit cell death. ${\beta}$-Carbolines decreased the condensation and fragmentation of nuclei caused by dopamine in PC12 cells. ${\beta}$-Carbolines inhibited the decrease in mitochondrial transmembrane potential, cytochrome c release, formation of reactive oxygen species and depletion of GSH caused by dopamine in PC12 cells, whereas deprenyl did not decrease dopamine-induced mitochondrial damage. ${\beta}$-Carbolines, deprenyl and antioxidants depressed the formation of nitric oxide and melanin in dopamine-treated PC12 cells. The results suggest that cell death due to dopamine PC12 cells is mediated by caspase-8, -9 and -3. Unlike deprenyl, ${\beta}$-carbolines may attenuate the dopamineinduced cell death in PC12 cells by suppressing change in the mitochondrial membrane permeability through inhibition of the toxic action of reactive oxygen and nitrogen species.

Preparation and Physical Properties of Hydrogle Lens Containing N,N-Dimethylacrylamide (N,N-Dimethylacrylamide를 포함한 하이드로젤 렌즈의 제조 및 물리적 특성)

  • Kim, Tae-Hun;Sung, A-Young
    • Journal of the Korean Chemical Society
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    • v.54 no.6
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    • pp.761-765
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    • 2010
  • Poly (N,N-dimethylacrylamide) is very useful in various fields due to its remarkable properties, such as water solubility and biocompatibility. This study used N,N-dimethylacrylamide with the cross-linker EGDMA (ethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate), MMA (methyl methacrylate), NVP (N-vinyl-2-pyrrolidone) and the initiator AIBN (azobisisobutyronitrile) for copolymerization. Measurement of the physical properties of the copolymerized polymer showed that the water content was 36 - 42%, refractive index was 1.433 - 1.426 and visible ray transmittance 90 - 91% while the oxygen permeability showed a distribution between 13.1 and $21.29{\times}10^{-11}(cm^2/sec)$ ($mlO_2/mL{\times}mmHg$). The measurement showed that the increased amount of oxygen permeability of the copolymer measured using the polarographic method range between 11.0% and 80.5%. Based on the results of this study, the produced copolymer is suitable for use as a material to high oxygen permeability hydrogel lenses.

Printable Time Temperature Integrator Consisting of Oxygen Indicator and Cover Film with Various Oxygen Permeability (다양한 산소 투과도를 가진 커버필름과 산소지시물질로 제작된 인쇄형 TTI)

  • Kim, Do Hyeon;Jang, Han Dong;Han, Seo Hyeon;Ahn, Myung Hyun;Lee, Seung Ju
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.24 no.2
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    • pp.41-48
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    • 2018
  • A printable time temperature integrator (TTI) consisting of oxygen indicator and cover films with various oxygen permeability was developed. The printing ink contained methylene blue (oxygen indicator) which changed in color during storage. $TiO_2$ and glycerol for UV-activation of TTI and zein and ethanol for printing performance were also contained in the printing ink. The cover film on the ink was employed to control the color change rate and temperature dependency (Arrhenius activation energy, $E_a$) by using the different films (PE, PET, OPP, and LLDPE). The film properties were varied by annealing. TTI was produced by silk screen printing. As a result, the color change rates were different for the cover films, being the highest in TTI with LLDPE, followed by OPP, PE, and PET. The rate decreased with increase in the cover film thickness. The $E_a$ was the highest in TTI with LLDPE, followed by OPP, PE, and PET. The $E_a$ did not change with the cover film thickness. The annealed PVC and PET film were lower in oxygen permeability than the unannealed ones, indicating the lower color change rate.

Permeabilities of Korean Earthenware Containers and Their Potential for Packaging Fresh Produce

  • Seo, Gyeong-Hee;Chung, Sun-Kyung;An, Duck-Soon;Lee, Dong-Sun
    • Food Science and Biotechnology
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    • v.14 no.1
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    • pp.82-88
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    • 2005
  • Ethnic Korean onggi earthenwares were fabricated using different clay formulations and glazing treatments. Their permeability properties against oxygen, carbon dioxide, and moisture were measured at $20^{\circ}C$ and examined from the aspect of food preservation. Onggi walls consisted of micropores that offered higher gas and moisture permeation rates when compared with other food packaging materials. Earthenware walls were unique in having $CO_2/O_2$ permeability ratios of 0.60-1.00. Gas and moisture permeabilities were lower, with wall structure having lower porosity and surface glazing. Results revealed onggi jar packages of grape fruits could attain wide range of $O_2$ and $CO_2$ concentrations. Onggi containers present good opportunity to obtain optimum packaging conditions for respiring or ripening products, depending on commodity type.

Synthesis and Application for Ophthalmic Material of Polydimethylsiloxanewith Methacrylate Endgroup (Methacrylate 말단기를 가진 Polydimethylsiloxane의 합성 및 안의료용 소재로의 응용)

  • Ye, Ki-Hun;Sung, A-Young
    • Journal of the Korean Chemical Society
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    • v.53 no.3
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    • pp.335-339
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    • 2009
  • Polydimethylsiloxane (PDMS) with methacrylate endgroup is used as contact lens material with elasticity and high oxygen permeability. PDMS prepolymer with methacrylate endgroup was prepared by reacting PDMS (polydimethylsiloxane) with HEMA (2-hydroxyethyl methacrylate). The HEMA-substituted PDMS prepolymer was then copolymerized using AIBN (azobisisobutyronitrile) with BMA (butyl methacrylate; to increase elasticity and flexibility). The water content, oxygen permeability, and visible-ray transmissibility of the resulting polymer were measured to be 23%, 83% and Dk/t > 50, indicating that the copolymer can be used as a good contact lens material.

The effects of Seungmagalgeuntang-gamibang on the anti-allergic and immune response to mice (升麻葛根湯加味方이 마우스의 抗 ALLERGY 및 免疫反應에 미치는 影響)

  • Kim, Nam-Kwen;Hwang, Chung-Yeon;Lim, Gyu-Sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.8 no.1
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    • pp.1-19
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    • 1995
  • Seungmagalgeuntang-gamibang has long been known to have anti-allergic effect. However, the mechanism of action of Seungmagalgeuntang-gamibang is not well investigated. The author analysed the effects of Seungmagalgeuntang-gamibang on the vascular permeability, delayed-type and contact hypersensitivities, and phagocytic function, the results obtained are as follows: 1. Administration of Seungmagalgeungtang-gamibang decreased the vascular permeability induced by serotonin in the mouse. 2. Administration of Seungmagalgeuntang-gamibang decreased the vascular permeability induced by histamine without statistical significant. 3. Administration of Seungmagalgeuntang-gamibang decreased the delayed-type hypersensitivity induced by sheep red blood cells. 4. Administration of Seungmagalgeungtang-gamibang decreased the contact hypersensitivity induced by dinitrochlorobenzene. 5. Seungmagalgeungtang-gamibang increased the phagocytic-activities of macrophages in vitro and in vivo. 6. Seungmagalgeungtang-gamibang enhanced the formation of reactive oxygen intermediates in vitro and in vivo. The above results demonstrate that Seungmagalgeuntang-gamibang suppresses the hypersensitivity reactions with increasing the phagocytic functions and formations of reactive oxygen intermediates from macrophages.

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A Study on the Permeability and Chloride lon Penetration of Concrete (물-시멘트비에 따른 콘크리트의 투과성 및 염화물 이온의 침투성에 관한 연구)

  • 형원길;소형석;소승영;소양섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10c
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    • pp.179-184
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    • 1998
  • The permeability of concrete influences the durability of concrete remarkably. This paper describes a programme of permeability tests carried out to determine the differences between permeability coefficients derived using water, oxygen and chloride ions. Tests have been carried out on three concretes having water/cement ratios of 0.45, 0.55, 0.65 to measure their water, chloride-ion and gas permeability coefficients. The test results indicate that the permeability of concrete increase with the increase water cement ratios. The water and gas permeability coefficients is presented from $1.43$\times$10^{-10} to 19.01$\times$10^{-10}m/s$ and from $0.88$\times$10^{-10}$ to $1.59$\times$10^{-10}$m$^2$for concrete of different water cement ratios. The current intensity passing through the concrete is presented from 4504 to 4920 C.

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