• Title/Summary/Keyword: stabilizing agent

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Antioxidant and Liver-protective Effects of Caesalpinia sappan (소목 추출물의 항산화 및 간보호작용)

  • Ha, Hun
    • Environmental Analysis Health and Toxicology
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    • v.17 no.3
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    • pp.261-264
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    • 2002
  • The heartwood of Caeralpinia sappan L. (Leguminosae) has been used to activate blood flow, remove blood stasis, reduce swelling and relieve pain in Korean folk medicine. In this study. the antioxidant effects of this crude drug and its hepatoprotective activity on CCl$_4$-induced liver injury in rats were evaluated. The levels of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) reduced by CCl$_4$treatment, were recovered by this crude drug. It is suggested that Caesalpinia sappan L. have antioxidant effect. The increased levels of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) by CCl$_4$were also recovered by treatment with this crude drug. These results can be attributed to the agent's antioxidant and membrane - stabilizing actions.

Studies on the Stabilities of Insectcides Combined with some Stabilizers (살충제제(殺蟲製劑)의 안정성(安定性)에 관(關)한 연구(硏究))

  • Woo, Chong-Hak;Kim, Jae-Wan
    • Journal of Pharmaceutical Investigation
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    • v.1 no.1
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    • pp.101-108
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    • 1971
  • The stability and toxicity test for p.p'-DDT, DDVP and dipterex that put to used sample in this study effects is follows A. about p.p'-DDT (1) In elevating the stability of p.p'-DDT, best stabilizing solvent was benzene. (2) The stability-agent has no difficulty as long as it not contain metal ion for instance $Z_n^{2+}$,$C_r^{3+}$,$Al^{3+}$,and $Fe^{2+or3+}$ but in case of contain $F_e^{3+}$, the combination of salicylaminoguanidine is best effective. (3) Using this product for water-suspension, We must use span 40 for stability agent and adding it at the same time. (4) We must use container which does not week alkali and metal ion but it is to preserved in tight light-resistant container. (5) The stopper of container is adapted with above-mentioned condition of container, but it is better not to use metal material. (6) This product needs opening ventilation more than 30 minutes after diffusion or spray and in the room we remove cause of remained poison by cleaning the bottom. B. about DDVP and Dipterex (1) Benzene or toluene in best solvent to preserve stability of DDVP and Dipterex. (2) Span 40 is superior for stability agent of this product and second is span 80. (3) The pH of solution is very stable in pH 5-6 and comparative stable in alkali more than p,p'-DDT. (4) Container is to preserved in tight, lightresistant container and especially be careful of outflow and inflow of water. (5) Because this product is centeral stimulant poison, we must pay attention to prevent cause of contact diadermic toxicity after use.

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A Novel Approach for Sericin-Conjugated Silver Nanoparticle Synthesis and Their Potential as Microbicide Candidates

  • Lv, Xiaowen;Wang, Huanru;Su, Airong;Chu, Ying
    • Journal of Microbiology and Biotechnology
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    • v.28 no.8
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    • pp.1367-1375
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    • 2018
  • Silver nanoparticles have been widely applied for biomedical areas owing to their potent antiviral and antibacterial activities. Synthesis of silver nanoparticles using biomacromolecules is more efficient, environment-friendly, and cost-saving compared with the traditional approach. In this paper, a novel approach was developed to establish a reaction system with $Ag^+-BH4^--sericin$ to synthesize silver nanoparticles conjugated to sericin (AgNPs-Sericin). Sericin could be as a good dispersant and stabilizing agent, which is able to modify nanoscaled AgNPs, the average diameter of which was only $3.78{\pm}1.14nm$ prepared in a 0.3 mg/ml sericin solution. The characterizations of the AgNPs-Sericin were determined by FTIR, thermogravimetry, and XRD analyses. The results showed that the synthesized AgNPs conjugated with sericin as organic phase. Via SAED and XRD analysis, we showed that these AgNPs formed polycrystalline powder with a face-centered cubic structure of bulk metals. Moreover, we investigated the antiviral and antibacterial activities of AgNPs-Sericin, and the results showed that AgNPs-Sericin exhibited potent anti-HIV-1 activity against CCR5-tropic and CXCR4-tropic strains, but no significant cytotoxicity was found toward human genital epithelial cells compared with free silver ions, which are accepted as a commonly used potent antimicrobial agent. Moreover, its antibacterial activity was determined via flow cytometry. The results showed that AgNPs-Sericin could suppress gram-negative (E. coli) and gram-positive (S. aureus) bacteria, but more was potent for the gram-negative one. We concluded that our AgNPs-Sericin could be a potential candidate as a microbicide or antimicrobial agent to prevent sexually transmitted infections.

Energy-efficient intrusion detection system for secure acoustic communication in under water sensor networks

  • N. Nithiyanandam;C. Mahesh;S.P. Raja;S. Jeyapriyanga;T. Selva Banu Priya
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.6
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    • pp.1706-1727
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    • 2023
  • Under Water Sensor Networks (UWSN) has gained attraction among various communities for its potential applications like acoustic monitoring, 3D mapping, tsunami detection, oil spill monitoring, and target tracking. Unlike terrestrial sensor networks, it performs an acoustic mode of communication to carry out collaborative tasks. Typically, surface sink nodes are deployed for aggregating acoustic phenomena collected from the underwater sensors through the multi-hop path. In this context, UWSN is constrained by factors such as lower bandwidth, high propagation delay, and limited battery power. Also, the vulnerabilities to compromise the aquatic environment are in growing numbers. The paper proposes an Energy-Efficient standalone Intrusion Detection System (EEIDS) to entail the acoustic environment against malicious attacks and improve the network lifetime. In EEIDS, attributes such as node ID, residual energy, and depth value are verified for forwarding the data packets in a secured path and stabilizing the nodes' energy levels. Initially, for each node, three agents are modeled to perform the assigned responsibilities. For instance, ID agent verifies the node's authentication of the node, EN agent checks for the residual energy of the node, and D agent substantiates the depth value of each node. Next, the classification of normal and malevolent nodes is performed by determining the score for each node. Furthermore, the proposed system utilizes the sheep-flock heredity algorithm to validate the input attributes using the optimized probability values stored in the training dataset. This assists in finding out the best-fit motes in the UWSN. Significantly, the proposed system detects and isolates the malicious nodes with tampered credentials and nodes with lower residual energy in minimal time. The parameters such as the time taken for malicious node detection, network lifetime, energy consumption, and delivery ratio are investigated using simulation tools. Comparison results show that the proposed EEIDS outperforms the existing acoustic security systems.

Dimensional Stability of Waterlogged Archaeological Wood in PEG, Lactitol and Sucrose Treatment (수침목재의 PEG, 락티톨, 슈크로오스 처리에 의한 치수안정화 효과)

  • Lee, Hyo Sun;Kang, Ae Kyung;Park, Sang Jin
    • Journal of Conservation Science
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    • v.8 no.1 s.11
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    • pp.28-32
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    • 1999
  • The performance of dimensional stabilization of lactitol, PEG (Mw, 4000), and sucrose was evaluated for thin sections of oak wood (Quercus sp.) that had been buried in underground for presumably 1500 years. Thin wood sections of the specimen were soaked for three and seven days in each stabilizing agent with wide concentration ranges of 10, 30, 50, and $70\%$ by weight. Sucrose showed the largest weight gain among three agents, and the shrinkage of cross sections were found to be $1\%\;and\;4\%$ for three and seven days soaking, respectively. The result showed that sucrose among three stabilizing agents used was the best for the dimensional stabilization of the oak wood.

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Production and Characterization of Lipopeptide Biosurfactant from Bacillus subtilis A8-8

  • Lee Sang-Cheol;Yoo Ju-Soon;Kim Sun-Hee;Chung Soo-Yeol;Hwang Cher-Won;Joo Woo-Hong;Choi Yong-Lark
    • Journal of Microbiology and Biotechnology
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    • v.16 no.5
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    • pp.716-723
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    • 2006
  • A biosurfactant-producing bacterial strain was selected from oil-contaminated soil because of its ability to degrade crude oil and tributyrin $(C_{4:0})$. The strain was identified as Bacillus subtilis A8-8 based on its morphological, biochemical, and physiological characteristics. When B. subtilis A8-8 was grown with crude oil as the sole carbon source, the biosurfactant from the strain emulsified crude oil, vegetable oil, and hydrocarbons. Soybean oil was the optimum substrate for the emulsifying activity and emulsion stability of the biosurfactant, both of which were superior to those of several commercially available surfactants. The biosurfactant was purified by a procedure including HCl precipitation, methanol treatment, and silica-gel chromatography. The partially purified biosurfactant was analyzed by TLC (thin-layer chromatography), SDS-PAGE, and HPLC and it reduced the surface tension of water from 72 mN/m to 26 mN/m at a concentration of 30 mg/l. Therefore, the purified lipopeptide biosurfactant has strong properties as an emulsifying agent and acts as an emulsion-stabilizing agent.

Stability of Oxidizer $H_2O_2$ for Copper CMP Slurry (구리 CMP 슬러리를 위한 산화제 $H_2O_2$의 안정성)

  • Lee, Do-Won;Kim, In-Pyo;Kim, Nam-Hoon;Kim, Sang-Yong;Seo, Yong-Jin;Chang, Eui-Goo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.382-385
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    • 2003
  • Chemical mechanical polishing(CMP) is an essential process in the production of copper-based chips. On this work, the stability of Hydrogen Peroxide($H_2O_2$) as oxidizer of Cu CMP slurry has been investigated. $H_2O_2$ is known as the most common oxidizer in Cu CMP slurry. Copper slowly dissolves in $H_2O_2$ solutions and the interaction of $H_2O_2$ with copper surface had been studied in the literature. Because hydrogen peroxide is a weak acid in aqueous solutions, a passivation-type slurry chemistry could be achieved only with pH buffered solution.[1] Moreover, $H_2O_2$ is so unstable that its stabilization is needed using as oxidizer. As adding KOH as pH buffering agent, stability of $H_2O_2$ decreased. However, stability went up with putting in small amount of BTA as film forming agent. There was no difference of $H_2O_2$ stability between KOH and TMAH at same pH. On the other hand, $H_2O_2$ dispersion of TMAH is lower than that of KOH. Furthermore, adding $H_2O_2$ in slurry in advance of bead milling lead to better stability than adding after bead milling. Generally, various solutions of phosphoric acids result in a higher stability. Using Alumina C as abrasive was good at stabilizing for $H_2O_2$; moreover, better stability was gotten by adding $H_3PO_4$.

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Isolation and Characteristics of Biosurfactant Producing Bacterium, Bacillus sp. TBM 911-5 (Biosurfactant 생산균주 Bacillus sp. TBM 911-5의 분리 및 특성)

  • 김선희;정연주;이상철;유주순;주우홍;정수열;최시림;최용락
    • Journal of Life Science
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    • v.14 no.2
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    • pp.320-324
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    • 2004
  • The objective of this study was investigate the characteristic of biosurfactant produced from the isolated strain. The strain was isolated from soil samples and identified as Bacillus sp. TBM 911-5 by physiological characteristics and the partial nucleotide sequence analysis of 16S rDNA. We measured the surface tension every 6 hours for 80 hours. The surface tension of the culture filtrate of Bacillus sp. TBM 911-5 was decreased to 29 mN/m. Biosurfactant concentration was determined by diluting the culture filtrate until the critical micelle concentration (CMC). The biosurfactant emulsified hydrocarbons, vegetable oil and crude oil. Using soybean oil as substrate, the maximum emulsification activity and stability was obtained from the biosurfactant. The biosurfactant produced from Bacillus sp. TBM 911-5 had strong properties as an emulsifying agent and an emulsion-stabilizing agent.

A Study on the Properties of Dicalcium Phosphate Dihydrate According to the Manufacturing Condition (제이인산(第二燐酸)칼슘의 제조조건(製造條件)에 따른 성상(性狀) 연구(硏究))

  • Lah, Woon-Lyong;An, Kyung-Ran;Han, Kwan-Sup;Lee, Gye-Joo
    • Journal of Pharmaceutical Investigation
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    • v.6 no.1
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    • pp.26-32
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    • 1976
  • Dicalcium phosphate dihydrate (DCPD) is the most widely-used dentifrice abrasive in non-therapeutic tooth-paste requiring, low abrasive level, high stability and excellent compatibility with other formulation ingredients. One of the difficulties encountered in the use of this material in tooth-paste is that unless storage of the product is maintained at a relative low temperature there is a distinct tendency to lose water of crystallization. Another difficulty which has been encountered is that there is a tendency for the product to become lumpy. Various means have been proposed for increasing the stability and overcoming the lumping tendency, most of which means comprise the addition of stabilizing agent. But there is not any report about the relationships between the mechanism of dehydration, physical properties, structure and manufacturing condition. In this experiment, DCPD were manufactured by methods of Moss' patent, its two varied and J.P.VIII, these were studied by means of stability test, IR spectra, and DTA. According to the manufacturing conditions, DCPD has different physical properties and structures, i. e., monoclinic system of low drying temperature, triclinic system of high drying temperature. Dehydration of DCPD may be supposed one step debydration at about $100^{\circ}$ and it finaly converts to ${\gamma}-pyrophosphate$ at about $465^{\circ}$ and if the drying temperature is high it becomes DCP anhydrous. DCPD made by Moss' patent is thought of the best polishing agent of tooth-paste.

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Cooperative Surveillance and Boundary Tracking with Multiple Quadrotor UAVs (복수 쿼드로터 무인기를 이용한 협업 감시 및 경계선 추종)

  • Lee, Hyeon Beom;Moon, Sung Won;Kim, Woo Jin;Kim, Hyoun Jin
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.5
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    • pp.423-428
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    • 2013
  • This paper investigates a boundary tracking problem using multiple quadrotor UAVs to detect and track the boundary of physical events. We set the boundary estimation problem as a classification problem of the region in which the physical events occur, and employ SVL (Support Vector Learning). We also demonstrate a velocity vector field which is globally attractive to a desired closed path with circulation at the desired speed and a virtual phase for stabilizing the collective configuration of the multiple quadrotors. Experimental results with multiple quadrotors show that this study provides good performance of the collective boundary tracking.