• Title/Summary/Keyword: forming agent

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Development of Eco-friendly Lead Substitute Materials (친환경 납추 대체소재 개발)

  • Gwon, Jin Uk;Song, Hee Jin;Hwang, Dae Youn;Kim, Hye Sung
    • Journal of the Korean Society for Heat Treatment
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    • v.35 no.3
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    • pp.130-138
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    • 2022
  • In this study, the characteristic of an amorphous fishing weight material according to controlling the alloy type and alloy composition of the glass forming agent added in PbO2 oxide was investigated. According to the experimental, when the glass forming agent of 15wt%SiO2-1wt%MgO content was added in β-PbO2, an amorphous fishing weight substitute having the lowest friction coefficient, excellent corrosion resistance and durability was obtained. The cell number of PbO2-15wt%SiO2-1wt%MgO sample incubated in cell culture fluid tended to hardly decrease even after a lapse of 24 hours, It means that the fabricated PbO2-15wt%SiO2-1wt%MgO sample is significantly less-toxic and harmless to the human body, unlikely to metallic lead. It is considered that an fabricated amorphous fishing weight substitute proved to have a potential as an eco-friendly material with little marine pollution.

Effect of Surfactant and Anti-foaming Agent on the Properties of Silicone Rubber Impression Material (계면활성제와 소포제가 실리콘 고무인상재의 물성에 미치는 영향)

  • Kim, Kyoung-Nam;Cho, Lee-Ra;Oh, Young-Il;Kang, Seung-Kyung;Chung, Kyung-Ho
    • Elastomers and Composites
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    • v.36 no.2
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    • pp.102-110
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    • 2001
  • The three types of surfactants such as nonylphenoxy poly(ethylene) ethanol homologues, caster oil poly(ethylene) ethanol homologues, and sodium perfluoroalkyl carboxylates are used to improve the wettability of rubber impression material. Among the surfactants, the usage of sodium perfluoroalkyl carboxylates containing fluoro group resulted in the lowest surface energy of impression material and the result gave the positive effect on the wettability of rubber impression material to teeth. Also, the anti-foaming agents were used to reduce or remove the hydrogen gas generating on the impression material by reaction. In the case of rubber impression material containing sodium perfluoroalkyl carboxylate as a surfactant, it was found that the tear strength of rubber impression material increased over 3 N/mm with the addition of anti-forming agent. Therefore, the anti-foaming agent could contribute to the mechanical property of rubber impression material without the change of surface property.

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Relationship between biofilm formation and the antimicrobial resistance in the Staphylococcus spp. isolated from animal and air

  • Seo, Yeon-Soo;Lee, Deog Young;Kang, Mi Lan;Lee, Won Jung;Yoo, Han Sang
    • Korean Journal of Veterinary Research
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    • v.49 no.3
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    • pp.231-236
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    • 2009
  • Biofilm has been described as a barrier, which produced by microorganisms to survive and protect themselves against various environments, like antibiotic agents. Staphylococcus spp. is a common cause of nosocomial and environmental infection. Thirty-six and thirty-five Staphylococci were isolated from animals and air, respectively. Based on the biofilm forming ability of the bacterium reported in our previous report, relationship between biofilm formation and antibiotic-resistance was investigated in this study. Regarding antibiotics susceptibility, cefazolin was the most effective agent to the bacteria. Strong biofilm-forming Staphylococcus spp. isolates might have a higher antibiotic resistance than weak biofilm isolates regardless of the presence of antibiotic resistance genes (p < 0.05). This result suggested that the chemical complexity of the biofilm might increase the antibiotic resistance due to the decrease of antibiotic diffusion into cells through the extensive matrix.

Formulation Design and Evaluation of Niosome Containing Itraconazole for Dermal Delivery System (니오좀 시스템을 이용한 이트라코나졸 외용제의 제제 설계 및 평가)

  • Cho, Hye-Jung;Kyong, Kee-Yeol;Lee, Gye-Won;Jee, Ung-Kil
    • Journal of Pharmaceutical Investigation
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    • v.35 no.3
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    • pp.165-171
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    • 2005
  • Itraconazole is a triazole antifungal agent to inhibit most fungal pathogens. However, it is difficult for itraconazloe to be delivered by topical system due to its poor aqueous solubility. First, niosomes containing drug were prepared with span 60, cholesterol. tocopherol and poloxamer 407 as vesicle forming agents in an effort to increase solubility of itraconazole. And then prepared niosomes were dispersed in O/W creams (containing xanthan gum, glycerin, vaseline, glyceryl monostearate and $Cerix^{\circledR}-5$) or gels (containing xanthan gum and poloxamer 407). Both creams and gels were evaluated with respect to their rheological properties, in vitro permeation through excised skin of hairless mouse. Creams or gels containing niosome showed pseudoplastic flow and hysteresis loop. For both creams and gels, viscosity was increased with increasing the content of glycerine or vaseline and the content of gel forming polymer, respectively. In creams, the permeability of drug to skin was decreased with increasing the viscosity of cream. The permeability of drug was affected by pH as well as viscosity of gel. In vitro permeation test results demonstrated that cream formulations showed better permeability than gels. In conclusion, these results suggest that creams formulation containing niosome can be useful for the topical delivery of intraconazole.

Effects of Leachate during Vegetable Waste Composting using Rotary Drum Composter

  • Varma, V. Sudharsan;Kalamdhad, Ajay S.
    • Environmental Engineering Research
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    • v.19 no.1
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    • pp.67-73
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    • 2014
  • In India, disposal of vegetable market waste along with municipal solid waste in landfills or dumpsites is creating much nuisance in terms of odor nuisance, leachate production, and greenhouse gas emission into the atmosphere. Therefore, vegetable waste with high biodegradable and nutrient content is composted in a 550-L batch scale rotary drum composter to study the degradation process and its compost properties for its potential reuse as high quality compost. A total 150 kg of working volume was fixed for composting studies with two different ratios, trial A (6:3:1) of C/N 24 and trial B (8:1:1) of C/N 30, respectively. A maximum of $63.5^{\circ}C$ and $61.2^{\circ}C$ was observed in trials A and B; an average of $55^{\circ}C$ for more than 5 days, which helped in the degradation of organic matter and reduction of total and fecal coliform. The temperature dropped suddenly after the thermophilic stage in trial B, and leachate was observed due to insufficient amount of bulking agent. Mesophilic bacteria dominated during the initial stages of composting, and reduced considerably during the thermophilic stage. During the thermophilic stage, the rise in spore-forming organisms, including spore-forming bacteria, fungi, actinomycetes and streptomycetes, increased and these were predominant until the end of the composting process. By examination, it was observed that moisture and leachate production had adverse effects on the compost parameters with higher loss of micronutrients and heavy metals.

The Effect of Centrally Active Antihypertensive Agent on Biosynthetic Enzyme Activity of Neurotransmitter in Brain (중추성 항고혈압약이 뇌내 신경전달물질의 생합성 효소에 미치는 영향)

  • 윤재순
    • YAKHAK HOEJI
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    • v.29 no.4
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    • pp.165-175
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    • 1985
  • It has been reported that clonidine is $\alpha_2$-adrenergic agonist, potnet new hypotensive drug in human with low dose. The change in blood pressure is implicated in the concentration, release, uptake and metabalism of catecholamine and activity of catecholamine synthesizing enzyme in specific brain areas. Thus the experiment was set up to investigate the effect on the enzyme activity of clonidine alone and that of clonidine pretreated with imipramine or tranylcypromine by measuring activity of the Dopa-forming enzyme, tyrosine hydroxylase (TH) and epinephrine forming enzyme, phenylethanolamine-N-methyl transferase (PNMT) in brain and adrenal gland. The TH activity in brainstem and substantia nigra is decreased by intraperitoneally administered clonidine 0.1mg/kg twice a day for 5 days, but increased in the rats pretreated with imipramine 10mg/kg intraperitoneally given 26 hrs and 5 hrs before decaptitation. However the TH activity in all regions of brain is increased in rats pretreated with tranylcypromine 10mg/kg intraperitoneally twice a day for 5 days. The effect of clonidine on TH activity is due to inhibition release of norepinephrine by activation of presynaptic $\alpha_2$-adrenoreceptor, axon terminal result in the decrease of TH activity in brain. The increasing of TH activity in brain results in attenuation of the role of clonidine by pretreated with imipramine or tranylcypromine in rats. The activity of PNMT was not significantly affected by clonidine, imipramine and tranylcypromine in adrenal gland.

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Isolation of Lichen-forming Fungi from Hungarian Lichens and Their Antifungal Activity Against Fungal Pathogens of Hot Pepper Anthracnose

  • Jeon, Hae-Sook;Lokos, Laszlo;Han, Keon-Seon;Ryu, Jung-Ae;Kim, Jung-A;Koh, Young-Jin;Hur, Jae-Seoun
    • The Plant Pathology Journal
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    • v.25 no.1
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    • pp.38-46
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    • 2009
  • Lichen-forming fungi (LEF) were isolated from 67 Hungarian lichen species from ascospores or thallus fragments. LFF were successfully isolated from 26 species with isolation rate of 38.8%. Of the total number of isolation from ascospores (27 species) and thallus fragments (40 species), 48% and 32.5% of the species were successfully isolated, respectively. Comparison of rDNA sequences of ITS regions between the isolated LFF and the original thallus confirmed that all the isolates originated from the thallus fragments were LEF. The following 14 species of LEF were newly isolated in this study; Acarospora cervina, Bacidia rubella, Cladonia pyxidata, Lasallia pustulata, Lecania hyaline, Lecanora argentata, Parmelina tiliacea, Parmotrema chinense, Physconia distorta, Protoparmeliopsis muralis, Ramalina pollinaria, Sarcogyne regularis, Umbilicaria hirsuta, Xanthoparmelia conspersa and X. stenophylla. Antifungal activity of the Hungarian LFF was evaluated against plant pathogenic fungi of Colletotrichum acutatum, C. coccodes and C. gloeosporioides, causal agent of anthracnose on hot pepper. Among the 26 isolates, 11 LFF showed more than 50% of inhibition rates of mycelial growth of at least one target pathogen. Especially, LFF of Evernia prunastri, Lecania hyalina and Lecanora argentata were remarkably effective in inhibition of mycelial growth of all the tested pathogens with antibiotic mode of action. On the other hands, five isolates of Cladonia furcata, Hypogymnia physodes, Lasallia pustulata, Ramalina fastigiata and Ramalina pollinaria exhibited fungal lytic activity against all the three pathogens. Among the tested fungal pathogens, C. coccodes seemed to be most sensitive to the LFF. The Hungarian LFF firstly isolated in this study can be served as novel bioresources to develop new biofungicides alternative to current fungicides to control hot pepper anthracnose pathogenic fungi.

Immunosuppressive Effects of Bryoria sp. (Lichen-Forming Fungus) Extracts via Inhibition of CD8+ T-Cell Proliferation and IL-2 Production in CD4+ T Cells

  • Hwang, Yun-Ho;Lee, Sung-Ju;Kang, Kyung-Yun;Hur, Jae-Seoun;Yee, Sung-Tae
    • Journal of Microbiology and Biotechnology
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    • v.27 no.6
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    • pp.1189-1197
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    • 2017
  • Lichen-forming fungi are known to have various biological activities, such as antioxidant, antimicrobial, antitumor, antiviral, anti-inflammation, and anti proliferative effects. However, the immunosuppressive effects of Bryoria sp. extract (BSE) have not previously been investigated. In this study, the inhibitory activity of BSE on the proliferation of $CD8^+$ T cells and the mixed lymphocytes reaction (MLR) was evaluated in vitro. BSE was non-toxic in spleen cells and suppressed the growth of splenocytes induced by anti-CD3. The suppressed cell population in spleen cells consisted of $CD8^+$ T cells and their proliferation was inhibited by the treatment with BSE. This extract significantly suppressed the IL-2 associated with T cell growth and $IFN-{\gamma}$ as the $CD8^+$ T cell marker. Furthermore, BSE reduced the expression of the IL-2 receptor alpha chain ($IL-2R{\alpha}$) on $CD8^+$ T cells and CD86 on dendritic cells by acting as antigen-presenting cells. Finally, the MLR produced by the co-culture of C57BL/6 and MMC-treated BALB/c was suppressed by BSE. IL-2, $IFN-{\gamma}$, and CD69 on $CD8^+$ T cells in MLR condition were inhibited by BSE. These results indicate that BSE inhibits the MLR via the suppression of $IL-2R{\alpha}$ expression in $CD8^+$ T cells. BSE has the potential to be developed as an anti-immunosuppression agent for organ transplants.

Biruloquinone, an Acetylcholinesterase Inhibitor Produced by Lichen-Forming Fungus Cladonia macilenta

  • Luo, Heng;Li, Changtian;Kim, Jin Cheol;Liu, Yanpeng;Jung, Jae Sung;Koh, Young Jin;Hur, Jae-Seoun
    • Journal of Microbiology and Biotechnology
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    • v.23 no.2
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    • pp.161-166
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    • 2013
  • At present, acetylcholinesterase (AChE) inhibitors are the first group of drugs to treat mild to moderate Alzheimer's disease (AD). Although beneficial in improving cognitive and behavioral symptoms, the effectiveness of AChE inhibitors has been questioned since they do not delay or prevent neurodegeneration in AD patients. Therefore, in the present study, in order to develop new and effective anti-AD agents from lichen products, both the AChE inhibitory and the neuroprotective effects were evaluated. The AChE inhibitory assay was performed based on Ellman's reaction, and the neuroprotective effect was evaluated by using the MTT method on injured PC12 cells. One AChE inhibitor ($IC_{50}$ = 27.1 ${\mu}g/ml$) was isolated by means of bioactivity-guided isolation from the extract of lichen-forming fungus Cladonia macilenta, which showed the most potent AChE inhibitory activity in previous screening experiment. It was then identified as biruloquinone by MS, and $^1H$- and $^{13}C$-NMR analyses. The inhibitory kinetic assay suggested that biruloquinone is a mixed-II inhibitor on AChE. Meanwhile, biruloquinone improved the viability of the $H_2O_2$- and ${\beta}$-amyloid-injured PC12 cells at 1 to 25 ${\mu}g/ml$. The protective effects are proposed to be related to the potent antioxidant activities of biruloquinone. These results imply that biruloquinone has the potential to be developed as a multifunctional anti- AD agent.

Treatment Patterns of Osteoporosis and Factors Affecting the Prescribing of Bone-forming Agents: From a National Health Insurance Claims Database (건강보험 청구자료를 이용한 골다공증 치료제의 처방 양상과 골형성촉진제 처방에 미치는 영향요인)

  • Jeong, Jihae;Shin, Ju-Young
    • Korean Journal of Clinical Pharmacy
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    • v.31 no.1
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    • pp.27-34
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    • 2021
  • Objective: To analyze osteoporosis treatment patterns and teriparatide prescription-associated factors in Korea by using a national health insurance claims database. Methods: We utilized the Health Insurance Review & Assessment Service National Patients Sample claims database to identify patients (aged ≥50 years) with at least one osteoporosis claim (International Classification of Disease 10th revision code: M80, M81, M82) and at least one prescription for osteoporosis medication (antiresorptive agents: bisphosphonates, selective estrogen receptor modulators, denosumab, and calcitonin; bone-forming agent: teriparatide) in 2018. Demographic characteristics and healthcare utilization patterns were analyzed. Factors associated with teriparatide prescriptions were assessed using a multivariate logistic regression model. Results: Records showed that 44,815 patients were prescribed osteoporosis medications in 2018; the percentage of patients prescribed each treatment was as follows: 86.6% bisphosphonates, 13.9% selective estrogen receptor modulators, 3.1% calcitonin, 2.1% denosumab, and 0.7% teriparatide. A greater proportion of patients prescribed teriparatide were ≥75 years (53.4% vs. 33.8%) and had fractures (63.9% vs. 12.8%) compared to the same for antiresorptives (p<0.001). Patients prescribed teriparatide had higher Charlson comorbidity index values (1.2±1.3 vs. 0.9±1.2) and were more frequently hospitalized (0.8±1.3 vs. 0.1±0.5) than those prescribed antiresorptives (p<0.001). Elderly patients (≥75 years old; adjusted OR=1.66; 95% CI 1.16-2.38) and those with fractures (adjusted OR=6.23; 95% CI 4.76-8.14) were more likely to be prescribed teriparatide than antiresorptives. Conclusion: Patients prescribed teriparatide were older and more likely to have severe osteoporosis than those prescribed antiresorptives.