• Design & Manufacturing
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• v.17 no.2
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• pp.27-32
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• 2023

Liquid silicon rubber (LSR) has fine thermal compatibility and is widely used in various fields such as medical care and automobiles because it is easy to implement products with good fluidity. With the recent development of flexible sensors, the focus has been on manufacturing conductive elastomers, such as silicone as elastic materials, and carbon black, CNT, and graphene are mainly used as nanomaterials that impart conductive phases. In this study, mechanical behavior and curing behavior were measured and analyzed to manufacture a CB-LSR complex by adding Carbon Black to LSR and to identify properties. As a result of the compression test, the elastic modulus tended to increase as carbon black was added. When the swelling test and the compression set test were conducted, the swelling rate tended to decrease as the content of carbon black increased, and the compression set tended to increase. In addition, DSC measurements showed that the total amount of reaction heat increased slightly as the carbon black content increased. It is considered that carbon black was involved in the crosslinking of LSR to increase the crosslinking density and have a positive effect on oil resistance reinforcement.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.440-445
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• 2010

Effect of brine mineral water(BMW) on contact hypersensitivity reaction(CHR) was estimated using trimellitic anhydride (TMA) induced CHR in the mouse. BMW exhibited potent inhibitory activity on TMA induced CHR. BMW treatment suppressed the ear swelling, and attenuated hyper-activated lymph nodes stimulated by TMA challenge, thereby reduced their weight. The immunological index was analyzed after BMW administration in CHR. The level of serum IgE was significantly down regulated after BMW treatment. Furthermore, BMW showed inhibitory property of cytokine production. BMW treatment suppressed not only Th2 type cytokine, IL-4 but also pro-inflammatory cytokines such as TNF-${\alpha}$ and IL-6. From the histological analysis, the inflammatory context appeared by atopic dermatitis lesion after challenging with TMA are diminished by BMW treatment. Our results suggest that BMW may attenuate the development of CHR, and can be available for functional ingredient.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.14 no.1
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• pp.240-249
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• 2001

Objective : Anal Therapy is another way of taking medicine and applies to each field of clinical treatment extensively. Sinpo-tang(SPT) has been used for the treatment of a allergic rhinitis. In this study, the auther investigated the anti anaphylactic action of Sinpo-tang by anal therapy was investigated on cutaneous allergic reaction models. Methods : Results : 1. Sinpo-tang (0,001-0.1 g/kg) dose-dependently inhibited the compound 48/80-induced ear swelling response in mice. Inhibitory effect of Sinpo-tang was significant (P < 0.05) at the doses of 0.01, 0.1 g/kg. 2. Sinpo-tang (0.001-0.1 g/kg) inhibited the cutaneous allergic reaction activated by anti-dinitrophenyl IgE in rats. Of special note, Sinpo-tang (0.1 g/kg) inhibited the cutaneous allergic reaction by $68\%$. 3. This inhibitory effect of Sinpo-tang was confirmed by observation of alcian blue/nuclear fast red stained-mast cells in the cutaneous tissue. 4. Sinpo-tang (0.01-1 g/L) dose-dependently inhibited the compound 48/80-induced histamine release from the peritoneal mast cells. Conclusions :These results indicate that anal therapy of Sinpo-tang may be beneficial in the treatment of mast cell-mediated anaphylaxis by inhibition of histamine release from mast cells in vivo and in vitro.

• Polymer(Korea)
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• v.29 no.1
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• pp.91-95
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• 2005

The PVA hydrogels were prepared by the chemical and irradiation method to improve the heat resistance of these hydrogels at the high temperature. The physical properties such as the gel content, the degree of swelling and the gel strength for the synthesized hydrogels were examined. Gel content increased as the chemical reaction time and the irradiation dose increased, and gel content of the hydrogels were higher when the two-steps of chemical and irradiation method were used rather than only the chemical method. Gel strength increased as the chemical reaction time increased, and as the irradiation dose decreased. The hydrogels prepared by the chemical reaction for 5 hours and the two-steps had the heat resistance at the high temperature.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3242-3254
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• 2024

With the increasing usage of nuclear energy, how to properly dispose nuclear waste becomes a critical issue. In this study, a multiscale modeling approach combining the experimental findings is presented to address the illitization process, its impact on transport properties, and system behavior of bentonite buffer in engineered barrier systems (EBS). Through the pore-scale modeling, reactive transport properties such as illite generation rate and effective diffusion coefficient of potassium ion as a function of porosity and temperature are quantified by employing the findings of hydrothermal reaction experiments of Bentonil-WRK. The capability of pore-scale modeling has been developed based on the Darcy-Brinkmann-Stokes equation, involving the processes of smectite illitization and clay swelling. Obtained reactive transport properties are utilized as input parameters for the macroscale modeling to predict the long-term behavior of bentonite buffer in EBS. As such, this study involves the whole workflow of quantifying the reaction parameters of smectite illitization through the hydrothermal reaction experiments, and numerically modeling the reactive transport process of smectite illitization in bentonite buffer of EBS from pore-scale to macroscale. The presented multiscale modeling findings are expected to provide reliable solution for safe nuclear waste disposal with EBS.

• Archives of Plastic Surgery
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• v.43 no.1
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• pp.40-45
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• 2016

Background Bioabsorbable plates and screws are commonly used to reduce maxillofacial bones, particularly in pediatric patients because they degrade completely without complications after bone healing. In this study, we encountered eight cases of a delayed foreign body reaction after surgical fixation with bioabsorbable plates and screws. Methods A total of 234 patients with a maxillofacial fracture underwent surgical treatment from March 2006 to October 2013, in which rigid fixation was achieved with the Inion CPS (Inion, Tampere, Finland) plating system in 173 patients and Rapidsorb (Synthes, West Chester, PA, USA) in 61 patients. Their mean age was 35.2 years (range, 15-84 years). Most patients were stabilized with two- or three-point fixation at the frontozygomatic suture, infraorbital rim, and anterior wall of the maxilla. Results Complications occurred in eight (3.4%) of 234 patients, including palpable, fixed masses in six patients and focal swelling in two patients. The period from surgical fixation to the onset of symptoms was 9-23 months. Six patients with a mass underwent secondary surgery for mass removal. The masses contained fibrous tissue with a yellow, grainy, cloudy fluid and remnants of an incompletely degraded bioabsorbable plate and screws. Their histological findings demonstrated a foreign body reaction. Conclusions Inadequate degradation of bioabsorbable plates caused a delayed inflammatory foreign body reaction requiring secondary surgery. Therefore, it is prudent to consider the possibility of delayed complications when using bioabsorbable plates and surgeons must conduct longer and closer follow-up observations.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.17 no.2
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• pp.1-11
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• 2004

Objective: Chronic otitis media is an inflammation and infection of the middle ear which is persistent. Chronic otitis media occurs when the eustachian tube becomes blocked repeatedly, multiple infections, ear trauma, or swelling of the adenoids. A chronic ear may be the result of an acute ear infection that does not clear completely, or the result of recurrent ear infections. A chronic ear infection may be more destructive than an acute ear infection because its effects are prolonged, and it may cause permanent damage to the ear. Methods : Experimental animals made use of 4-5 weeks age(weight 20-25g) ICR(male)mouse. In the breeding farm, the lighting time was controlled from 7:00 am until 7:00 pm, the temperature was controlled within $22{\pm}0.5{\circ}$ and water and food were not limited. The extracts which were extracted from Hwangginaetak-san devided low dose group( 1.0g/kg-HN) and high dose group(3.0g/kg-HN), they were intragastrically administered to the mouse of sample A and sample B prior to LPS I.P injection. Compared with inflammation induced group which were induced by LPS, we measured the WBC count, IL-6 level in plasma and TNF-${\alpha}$ level in plasma. Results: 1. Hwangginaetak-san decreased WBC count in inflammatory reaction induced by LPS 2. Hwangginaetak-san decreased IL-6 level in inflammatory reaction induced by LPS. 3. Hwangginaetak-san didn't decreased TNF-${\alpha}$ level in inflammatory reaction induced by LPS Conclusion: According to above results, Hwangginaetak-san was improved its suppression effect to the inflammatory reaction through WBC count and IL-6 level. So Hwangginaetak-san is considered to be used for treatment of chronic otitis media by controlling the WBC count and IL-6 level in plasma.

• Elastomers and Composites
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• v.35 no.4
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• pp.288-295
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• 2000

It has been tried to decrease the crosslink density of vulcanized EPDM (ethylone-propylene-diene terpolymer) rubber through a chemical devulcanization treatment. Phase transfer catalyst, alkali metal (i.e., sodium), and triphenylphosphine have been used as a chemical agent ul the devulcanization treatment. Also it has been estimated the effect of the devulcanization treatment in the case of utilization of 2-butanol as a devulcanization reaction solvent. In the devulcanization treatment using quaternary ammonium salt as a phase transfer catalyst. the devulcanization effect has been studied with the variation of catalyst molecular weight and the choice of bromide or chloride cation. In the devulcanization treatment using sodium, it has been estimated the devulcanization treatment effect depending upon the variation of reaction variables such as amount of sodium used, reaction temperature, pressure of hydrogen gas, which is used as a reaction environment. The $M_c$ value (number average molecular weight between two crosslink points) has been experimentally estimated by the equilibrium swelling method and it is quantitatively related to the crosslink density. The estimation of devulcanization effect for vulcanized EPDM rubber has been carried out by the comparison of the $M_c$ values between the untreated and the treated specimens.

• The Journal of Korean Medicine
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• v.22 no.4
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• pp.10-21
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• 2001

Objective : To investigate the effect between Fructus Immaturus Ponciri (FIP, the immature fruit of Poncirus trifoliata) and Fructus Ponciri (FP, the ripe fruit of Poncirus trifoliata) on mast cell-mediated immediate-type allergic reactions. Methods : We performed anaphylactic reaction, histamine release, cAMP, $TNF-{\alpha}$, IgE. Results : The aqueous extract of FIP dose-dependently inhibited systemic and local allergic reaction was induced by compound 48/80 or anti-dinitrophenyl (DNP) IgE in a murine model. FIP also significantly inhibited mast cell-dependent ear swelling response induced by topical application of compound 48/80. When mice were orally pretreated with FIP, the plasma histamine levels were reduced in a dose-dependent manner. FIP dose-dependently inhibited histamine release from the rat peritoneal mast cells (RPMCs) was activated by compound 48/80 or anti-DNP IgE. The level of cAMP in RPMCs, when FIP was added, increased compared with that of a normal or control. In addition, FIP had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-a ($TNF-{\alpha}$) production from the RPMCs and IgE produced by lipopolysaccharide-stimulated murine whole spleen cells or U266B1 as human IgE-bearing B cells. However, FP showed the lower inhibition rate than those of FIP in above all allergic reactions. Conclusion : These data have important implications for our understanding of the clinical effects of FIP and FP on allergic diseases, and FIP is more effective than FP on the allergic reaction.

• YAKHAK HOEJI
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• v.55 no.1
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• pp.69-74
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• 2011

Hyaluronic acid (HA) is a natural polymer consisting of disaccharide units of D-glucuronic acid and N-acetyl-D-glucosamine. It has a great potential and success in cosmetic and biomedical applications. However, native HA is highly soluble and easily metabolized by enzymes such as hyaluronidase. Thus, various studies have been reported on modifying the physicochemical properties of HA, while maintaining its biocompatibility. For controlled drug delivery, many trials for fabricating HA microspheres were achieved under chemical reaction. The HA microspheres fabricated to improve the physical stability of HA using adipic acid dihydrazide (ADH) by cross-linking reaction has been reported earlier, however it lacks the desired physical stability and rapidly decomposes by swelling or enzymes. Therefore, we prepared double cross-linked HA microspheres (DC-HA microspheres) and alginate containing HA microspheres (AC-HA microspheres) to enhance its physicochemical properties. DC-HA microspheres were prepared using trisodium trimetaphosphate (STMP) under crosslinking reaction after ADH cross-linking reaction. AC-HA microspheres were prepared by adding alginate as a networking polymer. These microspheres were characterized by morphology, particle size, zeta potential, stability against hyaluronidase. Results showed that the DC-HA and AC-HA microspheres are more stable than that of HA microspheres.