• Title/Summary/Keyword: swelling agent

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Effect of Coupling Agent, Methylene Diisocyanate, in the Blending of Poly(methyl methacrylate)-Modified Starch and Styrene-Butadiene Rubber (폴리(메틸 메타크릴레이트)-개질된 전분과 스티렌-부타디엔 고무의 혼합에서 커플링제 메틸렌 디이소시아네이트의 효과)

  • Li, Mei-Chun;Cho, Ur Ryong
    • Elastomers and Composites
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    • v.49 no.2
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    • pp.117-126
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    • 2014
  • Methylene diisocyanate (MDI) was investigated as a novel interfacial modifier to enhance the performances of poly(methyl methacrylate)-modified starch/styrene-butadiene rubber (PMMA-modified starch/SBR) composites. Owing to the formation urethane linkage on one side and ${\pi}-{\pi}$ adhesion on the other side, MDI acted as an intermediated linkage role in the PMMA-modified starch/SBR interfaces, which was evidenced by the morphological, mechanical, dynamic mechanical and thermal decomposition studies. As a result, the presence of MDI significantly improved the mechanical properties and thermal stability of PMMA-modified starch/SBR composites. In addition, the effect of starch concentration on the various performances of the resulted MDI/PMMA-modified starch/SBR composites, such as morphology, vulcanization characteristics, mechanical properties, toluene swelling behavior, and thermal stability were investigated and discussed in detail. The obtained MDI/PMMA-modified starch/SBR composites exhibited superior mechanical properties to carbon black/SBR (CB/SBR) composites, demonstrating the potential use of the renewable starch as a substitute for CB in the rubber compounds.

Physicochemical Properties of Fibrous Material Fraction from By-product of Aloe vera Gel Processing (알로에 베라 겔 가공부산물로서의 섬유질 분획의 성분 및 물리화학적 특성)

  • Baek, Jin-Hong;Lee, Shin-Young
    • Food Engineering Progress
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    • v.14 no.2
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    • pp.118-126
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    • 2010
  • The fibrous material fraction as a by-product from the commercial aloe vera gel processing was obtained and freeze dried. The physicochemical characteristics such as the proximate composition, crystalline/surface structures and several physical functionalities including the water holding capacity (WHC), swelling capacity (SW), oil holding capacity (OHC), emulsion/foam properties and viscosity properties of this powdered sample (100 mesh) were investigated and analyzed by comparison with commercial $\alpha$-cellulose as a reference sample. The total dietary fiber content of powdered sample was very high as much as 87.5%, and the insoluble dietary and soluble dietary fiber content ratios were 77.6 and 22.4%, respectively. The FT-IR spectrum of powdered sample showed a typical polysaccharide property and exhibited a x-ray diffraction pattern for cellulose III and IV like structure. SW (8.24${\pm}$0.15 mL/g), WHC(6.40${\pm}$0.19 g water/g solid) and OHC(10.32${\pm}$0.29 g oil/g solid) of freeze dried aloe cellulose were about 3.3, 1.4 and 2 times higher than those of commercial $\alpha$-cellulose, respectively. Aloe cellulose (~2%, w/v) alone had no foam capacity while improved the foam stability of protein solution (1% albumin+0.5% $CaCl_{2}$) by factor of 300%. Emulsion capacity of 2%(w/v) aloe cellulose was about 70% level of 0.5%(w/v) xanthan gum, but its emulsion stability was about 1.2 times higher than that of xanthan gum. Also, aloe cellulose containing CMC (carboxyl methyl cellulose) of 0.3%(w/v) showed a very good dispersity. Aloe cellulose dispersion of above 1%(w/v) exhibited higher pseudoplasticity and concentration dependence than those of $\alpha$-cellulose dispersion, indicating the viscosity properties for new potential usage such as an excellent thickening agent.

Development of Hydrogels to Improve the Safety of Yukhoe (Korean Beef Tartare) by Reducing Psychrotrophic Listeria monocytogenes Cell Counts on Raw Beef Surface

  • Oh, Hyemin;Kim, Sejeong;Lee, Soomin;Ha, Jimyeong;Lee, Jeeyeon;Choi, Yukyung;Lee, Yewon;Kim, Yujin;Seo, Yeongeun;Yoon, Yohan
    • Food Science of Animal Resources
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    • v.38 no.6
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    • pp.1189-1195
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    • 2018
  • This study developed an antimicrobial hydrogel to control Listeria monocytogenes in Yukhoe (Korean beef tartare). Four hydrogels (hydrogel 1: 5% alginate+1% chitosan+0.2% $CaCl_2$, hydrogel 2: 1% ${\kappa}$-carrageenan+1% chitosan, hydrogel 3: 2% ${\kappa}$-carrageenan+1% $CaCl_2$, and hydrogel 4: 2% ${\kappa}$-carrageenan+3% $CaCl_2$) were prepared. The hydrogels then absorbed 0.1% grapefruit seed extract (GSE) and 0.1% citrus extract (CE) for 30, 60, 120, and 240 min to be antimicrobial hydrogels. To select the most effective antimicrobial hydrogel, their swelling ratio (SR) and antilisterial activities were determined. The selected hydrogel ($2{\times}2cm$) was then placed on surface of beef (round; $3{\times}3cm$), where L. monocytogenes (ca. $10^6CFU/g$) were inoculated, and the cell counts were enumerated on PALCAM agar. Among the hydrogels, the SR of hydrogel 1 increased with absorbing time, but other hydrogels showed no significant changes. Antimicrobial hydrogel 1 showed higher (p<0.05) antilisterial activity than other antimicrobial hydrogels, especially for the one absorbed the antimicrobial for 120 min. Thus, the antimicrobial hydrogel 1 absorbed antimicrobials for 120 min was applied on raw beef at $4^{\circ}C$, and reduced (p<0.05) more than 90% of L. monocytogenes on raw beef. These results indicate that antimicrobial hydrogel 1 formulated with 0.1% GSE or 0.1% CE is appropriate to improve the safety of Yukhoe by reducing psychrotrophic L. monocytogenes cell counts on raw beef.

Suppressing Effects of Ethanol Extract from Dioscoreae Rhizoma on atope Dermatitis (부채마 에탄올 추출물의 아토피 피부염 억제 효과)

  • Do, Young-Bog;Song, Young-Soon
    • Journal of Digital Convergence
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    • v.17 no.8
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    • pp.257-264
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    • 2019
  • This study was conducted to investigate the effect of 70% ethanol extract (DR) on the mast cell-mediated allergic contact dermatitis induced by dinitrofluorobenzene in BALB / c mice, which affects the cell activity by antigen in RBL-2H3 mast cells Respectively. The ethanol extracts of RBL-2H3 cells activated by DNP-HSA and anti-DNP IgE antibodies inhibited the secretion of ${\beta}$-hexosaminidase, histamine, and IL-4 and $TNF-{\alpha}$ Production was suppressed. In the DNFB-induced contact allergic dermatitis animal model, treatment with ethanol extract reduced ear swelling and inhibited serum histamine and IL-4 secretion, and DR treatment effectively prevented mast cell infiltration in dermatitis-induced areas. As a result, the ethanol extract may be used as a therapeutic agent for mast cell-mediated allergic diseases such as atopic dermatitis.

Renoprotective Effect of Maydis Stigma on Puromycin Aminonucleoside-induced Nephrotic Syndrome (Puromycin Aminonucleoside에 의해 유도된 신증후군에 대한 옥미수(玉米鬚)의 보호효과)

  • Yoon, Jung-Joo;Kho, Min-Chol;Han, Byung-Hyuk;Kim, Hye-Yoom;Ahn, You-Mee;Lee, Yun-Jung;Lee, Ho-Sub;Kang, Dae-Gill
    • The Journal of Korean Obstetrics and Gynecology
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    • v.34 no.4
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    • pp.1-11
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    • 2021
  • Objectives: Nephrotic syndrome is a kidney disorder, which is characterized by proteinuria, edema (swelling), and hyperlipidemia. Maydis Stigma (Corn silk) has been widely used in Asia as a traditional medicine and is known to have a diuretic effect and is used for the treatment of edema and indigestion. Methods: The aim of this study is to investigate the improvement effect of Maydis Stigma in treating nephrotic syndrome induced by puromycin aminonucleoside. Sprague-Dawley rats were intravenously injected with 75 mg/kg/day puromycin aminonucleoside, then treated with either Losartan or 200 mg/kg/day Maydis Stigma for seven days. Results: Maydis Stigma significantly decreased ascites and proteinuria level. Plasma levels of blood urea nitrogen (BUN) and plasma creatinine reduced significantly by Maydis Stigma. In addition, treatment with Maydis Stigma attenuated histological damage. Treatment with Maydis Stigma also restored podocin expression and reduced inflammation markers such as intracellular adhesion molecules (ICAM-1), monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor alpha (TNF-α) and high-mobility group box-1 (HMGB1). Conclusions: Maydis Stigma ameliorates kidney injury in nephrotic syndrome rat models. Maydis Stigma exerts a renoprotective effect owing to its anti-inflammatory effects and reductions of ascites and proteinuria. Thus, these results indicate that Maydis Stigma is likely to be a promising agent in the treatment of nephrotic syndrome.

Chikungunya Virus nsP2 Impairs MDA5/RIG-I-Mediated Induction of NF-κB Promoter Activation: A Potential Target for Virus-Specific Therapeutics

  • Bae, Sojung;Lee, Jeong Yoon;Myoung, Jinjong
    • Journal of Microbiology and Biotechnology
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    • v.30 no.12
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    • pp.1801-1809
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    • 2020
  • Chikungunya virus (CHIKV) was first identified in 1952 as a causative agent of outbreaks. CHIKV is transmitted by two mosquito species, Aedes aegypti and A. albopictus. Symptoms after CHIKV infection in human are typically fever and joint pain, but can also include headache, muscle pain, joint swelling, polyarthralgia, and rash. CHIKV is an enveloped single-stranded, positive-sense RNA virus with a diameter of approximately 70 nm. The pathogenesis of CHIKV infection and the mechanism by which the virus evades the innate immune system remain poorly understood. Moreover, little is known about the roles of CHIKV-encoded genes in the viral evasion of host immune responses, especially type I interferon (IFN) responses. Therefore, in the present study, we screened CHIKV-encoded genes for their regulatory effect on the activation of nuclear factor kappa B (NF-κB), a critical transcription factor for the optimal activation of IFN-β. Among others, non-structural protein 2 (nsP2) strongly inhibited melanoma differentiation-associated protein 5 (MDA5)-mediated induction of the NF-κB pathway in a dose-dependent manner. Elucidation of the detailed mechanisms of nsP2-mediated inhibition of the MDA5/RIG-I signaling pathway is anticipated to contribute to the development of virus-specific therapeutics against CHIKV infection.

Studies on the Durable Characteristics of Self-Healing Concrete with High Water-Tightness for Artificial Ground (인공지반용 고수밀 기반 자기치유성 콘크리트의 내구특성에 관한 연구)

  • Song, Tae-Hyeob;Park, Ji-Sun;Kim, Byung-Yun
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.9
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    • pp.199-206
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    • 2019
  • Experimental study on the durability characteristics to examine the feasibility of concrete with high water-tightness and self-healing performance to minimize maintenance of concrete for artificial ground is as follows. 1) When blending agent, swelling agents, and curing accelerator were added on the ternary system cement with blast-furnace slag fine particles and fly ash to give a self-healing property, higher blending strengths by 82% at design standard strength of 24MPa and by 74% at design strength of 30MPa, respectively could be obtained. 2) The permeability test for the specimens having high water-tightness and no shrinkage showed that the permeability was reduced at maximum of 98%. However, the permeability was decreased as the design strength was increased, showing the reduction rate of 87% at the design strength of 50MPa. 3) The depth of carbonation of blast-furnace slag and fly ash was increased in all the specimens compared with those of OPC only. However, as the material age was increased, carbonation penetration depth was decreased compared with the reference blend. 4) Compared with the reference blending using only OPC, the freeze-thaw resistance was higher in the case of blending with 40% of blast-furnace slag and 10% of fly ash at the design standard strength of 50MPa. In addition, the freeze-thaw resistance in general was superior in the design standard strength of 50MPa with the lower water-binder ratio (W/B) as compared with the design standard strength of 24MPa and 30MPa with the high water-binder ratios.

Limited eye movement caused by clumping of fibrin glue used in blowout fracture surgery: a care report

  • Shin, Jin Yong;Lee, Nae-Ho;Kim, Min-Seok;Roh, Si-Gyun;Chung, Yoon Kyu
    • Archives of Craniofacial Surgery
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    • v.23 no.5
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    • pp.228-231
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    • 2022
  • Fibrin glue is a topical agent widely used for hemostasis, wound healing, and surgical adhesion. Complications of fibrin glue itself are extremely rare because it is absorbed over time, but can occur as a result of inappropriate application. We report a case of a postoperative complication caused by inappropriate application of fibrin glue in blow-out fracture surgery. A 65-year-old male patient presented with periorbital swelling and an open wound on the right infraorbital area. Computed tomography showed a right orbital floor fracture. After reduction of the herniated tissue into the orbit, an implant was inserted and fibrin glue was applied to stabilize the implant. This procedure was performed without difficulty, but the patient complained of persistent diplopia and limited eyeball movement after surgery. An imaging study showed a mass-like lesion, which was not a hematoma, in the orbital cavity. In a second operation, the mass was identified as clotted fibrin glue that had not been applied properly. After removal, the patient's symptoms were relieved without further complications. Appropriate and careful application of fibrin glue is necessary to avoid unnecessary complications.

Musculocutaneous and Median Neuropathy after MiraDry® Procedure for Axillary Hyperhidrosis (다한증 치료 기구인 MiraDry®에 의한 근피 및 정중신경 손상 증례)

  • Kim, Youngmin;Yoon, Mi-Jeong;Park, Sunha;Kim, Min Wook
    • Clinical Pain
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    • v.20 no.2
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    • pp.135-140
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    • 2021
  • MiraDry®, a microwave thermolysis device, is comparably new non-surgical agent in the field of eradication of sweat glands for treating axillary hyperhidrosis and osmidrosis. So far, altered sensation, swelling, and compensatory sweating are widely known as adverse effects of MiraDry®. Of the few reported MiraDry®-induced neuropathy cases, median and ulnar neuropathies are common. Although, one case has described radial nerve and posterior cord damage with maximized stimulation intensity, musculocutaneous nerve damage induced by MiraDry® has not been reported. Here, we report a case of a 30-year-old woman experiencing left hand weakness after receiving MiraDry® at a local dermatology clinic. Left brachial plexopathy, mainly involving the median nerve and the musculocutaneous nerve with partial axonotmesis, was confirmed by electrodiagnostic studies. Ultrasound evaluation showed corresponding results. This is the first case report of the musculocutaneous neuropathy by MiraDry®.

Antifungal Activity of Green and Chemically Synthesized ZnO Nanoparticles against Alternaria citri, the Causal Agent Citrus Black Rot

  • Hazem S. Elshafie;Ali Osman;Mahmoud M El-Saber;Ippolito Camele ;Entsar Abbas
    • The Plant Pathology Journal
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    • v.39 no.3
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    • pp.265-274
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    • 2023
  • Citrus black rot is a serious disease of citrus plants caused by Alternaria citri. The current study aimed to synthesize zinc oxide nanoparticles (ZnO-NPs) by chemically or green method and investigate their antifungal activity against A. citri. The sizes of synthesized as measured by transmission electron microscope of ZnO-NPs were 88 and 65 nm for chemical and green methods, respectively. The studied prepared ZnO-NPs were applied, in vitro and in situ, at different concentrations (500, 1,000, and 2,000 ㎍/ml) in post-harvest treatment on navel orange fruits to verify the possible control effect against A. citri. Results of in vitro assay demonstrated that, at concentration 2,000 ㎍/ml, the green ZnO-NPs was able to inhibit about 61% of the fungal growth followed by 52% of chemical ZnO-NPs. In addition, scanning electron microscopy of A. citri treated in vitro with green ZnO-NPs showed swelling and deformation of conidia. Results showed also that, using a chemically and green ZnO-NPs at 2,000 ㎍/ml in situ in post-harvest treatment of orange, artificially-infected with A. citri, has reduced the disease severity to 6.92% and 9.23%, respectively, compared to 23.84% of positive control (non-treated fruits) after 20 days of storage. The out findings of this study may contribute to the development of a natural, effective, and eco-friendly strategy for eradicating harmful phytopathogenic fungi.