• Title/Summary/Keyword: Free release

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Control of Free Formaldehyde Release from Resin Finished Fabric.( I ) -Effect of Aftertreatment with Urea- (수지가공포의 유리 Formaldehyde 발생억제( I ) -요소에 의한 후처리효과-)

  • Lee Jung Heui;Lee Soon Won;Kim Sung Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.3 no.2
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    • pp.29-36
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    • 1979
  • In order to control free formaldehyde release from fabric finished with urea-formaldehyde precondensate, the resin finished fabric was padded in urea or acylamide solution, dried and cured at $140^{\circ}C$. The effect of aftertreatment with urea or acrylamide on free formaldehyde release and on characteristics of resin finished fabric were examined. It was shown that aftertreatment with urea was effective to control free formaldehyde release, the free formaldelyde content in aftertreated fabric could be reduced from 900 ppm to 200 ppm and formaldehyde release under accelerated storage condition was also reduced from 8000 ppm to 1000 ppm. Polyacrylamide formed in the fiber during aftertreatment appeared to be a formaldehyde capture. Especially by washing the aftertreated fabric, the ability to control formaldehyde release under accelerated condition was not dimimished in contrast with aftertreated with unea. It suggests that polyacrylamide can be used as a formaldehyde capture which withstand diminution from washing.

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Testosterone-encapsulated Surfactant-free Nanoparicles of Poly(DL-lactide-co-glycolide): Preparation and Release Behavior

  • Jeong, Young-Il;Shim, Yong-Ho;Song, Ki-Chan;Park, Youeng-Guen;Ryu, Hwa-Won;Nah, Jae-Woon
    • Bulletin of the Korean Chemical Society
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    • v.23 no.11
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    • pp.1579-1584
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    • 2002
  • Since surfactant or emulsifiers remained on the nanoparticle surface significantly affect the physicochemical properties, the biodegradation rate, the biodistribution, and the biocompatibility of nanoparticles, surfactant-free nanoparticles should be good candidate. surfactant-free PLGA nanoparticles were successfully prepared by both the dialysis method and the solvent diffusion method. The PLGA nanoparticles prepared using the solvent diffusion method has a smaller particle size than the dialysis method. The solvent diffusion method was better for a higher loading efficiency than the dialysis method but the nanoparticle yield was lower. Testosterone (TST) release from the PLGA nanoparticles was dependent on the particle size rather than the drug contents. Testosterone release from the PLGA nanoparticles prepared by the solvent diffusion method using acetone was faster than those prepared by the dialysis method. TST release from the PLGA nanoparticles prepared by the solvent diffusion method using acetone and the dialysis method using dimethylformamide (DMF) was completed for 4 days while the PLGA nanoparticles prepared by the dialysis method using acetone showed approximately 80% TST release after 4 days. Since the PLGA nanoparticle degradation ratio was below 20% within 5 days at all samples while TST release completed within 4 days, TST release was dependent on the diffusion mechanism rather than degradation.

Effect of Resorcinol as Free Formaldehyde Scavenger for Fabric Finished with Urea-formaldehyde Precondensate. (Urea-Formaldehyde 수지가공포에 있어 Resorcinol의 유리 Formaldehyde 포착효과)

  • Kang, In-Sook;Kim, Sung-Reon
    • Textile Coloration and Finishing
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    • v.9 no.2
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    • pp.41-49
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    • 1997
  • To control free formaldehyde release from fabric finished with N-methylol compounds, resin finished cotton fabric was treated with resorcinol solution, dried and cured. Factors affecting to control formaldehyde release have been investigated. It was shown that the aftertreatment with resorcinol greatly suppressed the free formaldehyde release. Up to concentration of about 5% of resorcinol, the concentration of resorcinol effected on the control of free and evolved formaldehyde. And at high concentration of resorcinol, however, the concentration became rather insensitive to contol formaldehyde release. Addition of some salt catalysts such as ammonium chloride, zinc nitrate, sodium acetate and ammonium acetate, was effective in decreasing formaldehyde release. Considering the effect on the control of formaldehyde and crease recovery, ammonium acetate was concidered to be the best catalyst. It was observed that the optimum curing temperature for the resorcinol treatment was about 15$0^{\circ}C$, and that the curing time did not affected formaldehyde release over three minutes. Although the treatment of resorcinol had a little adverse effect on crease recovery of resin finished fabric, this effect could be negligible.

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Effect of Superoxide Dismutase on the Release of [$^3H$]-5-Hydroxytrytamine after Hypoxia from Rat Hippocampal Slices (흰쥐 해마 절편에서 저산소증에 의한 [$^3H$-5-Hydroxytrytamine의 유리 변동에 미치는 superoxide dismutase/catalase의 영향)

  • 이경은;박월미;배영숙
    • Toxicological Research
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    • v.13 no.4
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    • pp.359-365
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    • 1997
  • Many factors are known to be responsible for cerebral ischemic injury, such as excitatory neurotransmitters, increased intraneuronal calcium, or disturbance of cellular energy metabolism. Recently, oxygen free radicals, formed during ischemia/reperfusion, have been proposed as one of the main causes of ischemia/reperfusion injury. Therefore, to investigate the role of oxygen free radical during ischemia/reperfusion, in the present study the effect of endogenous oxygen free radical scavenger, superoxide dismutase / catalase(SOD / catalase) on the release of [$^3$H]-5-hydroxytryptamine([$^3$H]-5-HT) during hypoxia/reoxygenation in rat hippocampal slices was measured. The hippocampus was obtained from the rat brain and sliced 400 gm thickness with manual chopper. After 30 min's preincubation in the normal buffer, the slices were incubated for 20 min in a buffer containing [$^3$H]-5-HT(0.1 $\mu$M, 74 $\mu$Ci) for uptake, and washed. To measure the release of [$^3$H]-5-HT into the buffer, the incubation medium was drained off and refilled every ten minutes through a sequence of 14 tubes. Induction of hypoxia for 20 min (gassing it with 95% N$_2$/5% CO$_2$) was done in the 6th and 7th tube, and oxygen free radical scavenger, SOD / catalase was added 10 minutes prior to induction of hypoxia. The radioactivity in each buffer and the tissue were counted using liquid scintillation counter and the results were expressed as a percentage of the total activity. When slices were exposed to hypoxia for 20 min, [$^3$H]-5-HT release was markedly decreased and a rebound release of [$^3$H]-5-HT was observed on the post-hypoxic reoxygenation period. SOD / catalase did not changed the release of [$^3$H]-5-HT in control group, but inhibited the decrease of [$^3$H]-5-HT release in hypoxic period and rebound increase of [$^3$H]-5-HT in reoxygenation period. This result suggest that superoxide anion may play a role in the hypoxic-, and reoxygenation-induced change of [$^3$H]-5-HT release in rat hippocampal slices.

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The Anconeus Muscle Free Flap: Clinical Application to Lesions on the Hand

  • Jeon, Byung-Joon;Jwa, Seung Jun;Lee, Dong Chul;Roh, Si Young;Kim, Jin Soo
    • Archives of Plastic Surgery
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    • v.44 no.5
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    • pp.420-427
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    • 2017
  • Background It can be difficult to select an appropriate flap for various defects on the hand. Although defects of the hand usually must be covered with a skin flap, some defects require a flap with rich blood supply and adequate additive soft tissue volume. The authors present their experience with the anconeus muscle free flap in the reconstruction of various defects and the release of scar contractures of the hand. Methods Ten patients underwent reconstruction of the finger or release of the first web space using the anconeus muscle free flap from May 1998 to October 2013. Adequate bed preparations with thorough debridement or contracture release were performed. The entire anconeus muscle, located at the elbow superficially, was harvested, with the posterior recurrent interosseous artery as a pedicle. The defects were covered with a uniformly trimmed anconeus muscle free flap. Additional debulking of the flap and skin coverage using a split-thickness skin graft were performed 3 weeks after the first operation. Results The average flap size was $18.7cm^2$ (range, $13.5-30cm^2$). All flaps survived without significant complications. Vein grafts for overcoming a short pedicle were necessary in 4 cases. Conclusions The anconeus muscle free flap can be considered a reliable reconstructive option for small defects on the hand or contracture release of the web space, because it has relatively consistent anatomy, provides robust blood supply within the same operative field, and leads to no functional loss at the donor site.

A Comparative Functionality Evaluation of Paulownia Wood Storage Boxes and Acid-free Archival Boxes to Store the Annals of Joseon Dynasty - Indoor and Outdoor Temperature and Relative Humidity Controls, and Heat Release Rate -

  • Park, Hae Jin;Kim, Seong Eun;Lee, Jin Kyung;Chung, Yong Jae
    • Journal of Conservation Science
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    • v.38 no.1
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    • pp.72-79
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    • 2022
  • A paulownia wood has been widely used with various advantages as its low weight, permeability, convenient workability and aesthetic patterns for a long time. However, the related empirical researches and simultaneous evaluations of functionality are insufficient compared with acid-free archival boxes for now. In this study, the indoor and outdoor temperature and relative humidity control and heat release rate were evaluated under the controlled and uncontrolled circumstance in 2018. The paulownia wood storage box showed superior control effect of relative humidity than the acid-free archival box in constantly uncontrolled environment. Also, the possibility of the flame diffusion from the surface of the materials was higher for the paulownia materials, and the acid-free archival box showed more dangerous patterns in the early stages of the fire.

The Effect of Acteoside on Histamine Release and Arachidonic Acid Release in RBL-2H3 Mast Cells

  • Lee, Jin-Hee;Lee, Ji-Yun;Kang, Hyo-Suk;Jeong, Chan-Hun;Moon, Hee;Whang, Wan-Kyunn;Kim, Chang-Jong;Sim, Sang-Soo
    • Archives of Pharmacal Research
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    • v.29 no.6
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    • pp.508-513
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    • 2006
  • The effect of acteoside, a phenylpropanoid glycoside isolated from Clerodendron trichotomum Thunberg, on histamine and arachidonic acid release was investigated in RBL 2H3 cells. Histamine was dose-dependently released from RBL 2H3 cells by melittin, arachidonic acid and thapsigargin. In extracellular $Ca^{2+}-free$ solution, basal secretion of histamins increased by two fold. The response of histamine release to melittin and thapsigargin in $Ca^{2+}-free$ solution was significantly decreased, whereas the response to arachidonic acid was significantly increased as compared with those in normal solution. Acteoside inhibited histamine release induced by melittin, arachidonic acid and thapsigargin in a dose-dependent manner in the presence or absence of extracellular $Ca^{2+}$. However, the inhibitory activity of acteoside was more potent in normal solution than that in $Ca^{2+}-free$ solution. These data suggest that inhibitory mechanism of acteoside on histamine release may be related to extracellular $Ca^{2+}$. On the other hand, acteoside significantly inhibited arachidonic acid release and prostaglandin $E_2$ production Induced by $0.5\;{\mu}M$ melittin. It is possible that acteoside may be developed as an anti-inflammatory agent.

Development and Characterization of Membrane for Local Delivery of Cephalexin

  • Shin, Sang-Chul;Oh, In-Joon;Cho, Seong-Jin
    • Archives of Pharmacal Research
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    • v.19 no.1
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    • pp.1-5
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    • 1996
  • Laminated films composed of drug-containing reservoir layer and drug-free membrane were prepared. Zero-order drug release with lag time was achieved by laminating drug-free film onto the reservoir layer, while burst effect was observed on cast-on film. The rate controlling membrane was either attached to or cast directly into the reservoir. The release rate was independent on the reservoir composition but dependent on the composition of rate-controlling membrane. In growth inhibitory test of cephalexin from Eudragit RS film to Streptococcus Mutans, the disk even after release test for 72 hours showed more bacterial growth inhibition than that of control. Permeation of drug through rat skin was proportional to the HPC fraction in the film. We could control the release of cephalexin from the film by changing the fraction of Eudragit RS, HPC and DEP content. Consequently, Eudragit RS/HPC film was found to be very effective system for local delivery of drugs.

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Evaluation of Acute Toxicity about Leakage Waters of Antifouling Paints on Sebastes shlegeli and Artemia (방오도료 용출수의 조피볼락과 알테미아에 대한 급성독성 평가)

  • Kim, Pil-Geun;Park, Maeng-Eon;Lee, In-Won;Chun, Ho-Hwan;Park, Hyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.16 no.4
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    • pp.361-367
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    • 2010
  • The use of antifouling(AF) paints is the effective method for the protection of underwater structures from the development of marine fouling organisms. The ban on harmful substances in antifouling paints requires the development of new antifouling strategies although Tributyitin (TBT) compound had been used extensively as an active ingredient Alternatives should be as effective as conventional paints but have lower toxicity. In the present study, a TBT-free self-polishing (Cu SPC) AF paint containing $Cu_2O$, a Cu free SPC AF paint, and a Foul-release silicone AF paint, which were commercially available, were examined to investigate environmental erects of leakage waters employing Sebastes shlegeli and Artemia. Survival rates were inversely proportional to the concentration of leakage waters from AF paints and the acute toxicity of SPC AF paints was relatively higher than that of foul release AF paints.

A Simplified Method for Determining Modal Strain Energy Release Rate of Free-Edge Delaminations in Laminated Composite (적층복합재의 자유단 박리에 대한 모드별 스트레인 에너지해방률의 간이계산법)

  • Kim, Taek-Hyun;Oh, Taek-Yul;Kim, In-Kweon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.3
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    • pp.423-429
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    • 1997
  • A simplified method for determining the mode components of the strain energy release rate of free-edge delaminations in laminated composite is proposed. The interlaminar stresses are evaluated as an interface moment and interface shear forces that are obtained from the equilibrium equations at the interface between the adjacent layers. Deformation of an edge-delaminated laminate is calculated by using a generalized quasi-three dimensional classical laminated plate theory developed by the authors. The analysis provides closed-form expression for the three components of the strain energy release rate. Comparison of results with a finite element solution using the virtual crack closure technique shows good agreement. In the present study, laminated composite with stacking sequences of [30/-30/90]$_{s}$ were examined. The simple nature of the method makes it suitable for primary design analysis for the delaminations of laminated composite.e.