• Title/Summary/Keyword: Properties of substances

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Environmental Applications of Rare-Earth Manganites as Catalysts: A Comparative Study

  • Alami, D.
    • Environmental Engineering Research
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    • v.18 no.4
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    • pp.211-219
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    • 2013
  • Rare-earth manganites have a great potential for environmental applications based on their chemical and physical properties. The use of rare-earth manganites as catalysts for environmentally essential reactions was reviewed. Artificial neural networks were used to assess the catalytic activity in oxidation reactions. Relative catalytic activities of the catalysts were further discussed. We concluded that cerium manganite is the most practicable catalyst for technological purposes.

Evaluation of the Abuse Potential of Novel Amphetamine Derivatives with Modifications on the Amine (NBNA) and Phenyl (EDA, PMEA, 2-APN) Sites

  • Custodio, Raly James Perez;Botanas, Chrislean Jun;Yoon, Seong Shoon;de la Pena, June Bryan;dela Pena, Irene Joy;Kim, Mikyung;Woo, Taeseon;Seo, Joung-Wook;Jang, Choon-Gon;Kwon, Yong Ho;Kim, Nam Yong;Lee, Yong Sup;Kim, Hee Jin;Cheong, Jae Hoon
    • Biomolecules & Therapeutics
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    • v.25 no.6
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    • pp.578-585
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    • 2017
  • Recently, there has been a rise in the number of amphetamine derivatives that serve as substitutes for controlled substances (e.g. amphetamine and methamphetamine) on the global illegal drug market. These substances are capable of producing rewarding effects similar to their parent drug. In anticipation of the future rise of new and similar psychoactive substances, we designed and synthesized four novel amphetamine derivatives with N-benzyl, N-benzylamphetamine HCl (NBNA) substituent on the amine region, 1,4-dioxane ring, ethylenedioxy-amphetamine HCl (EDA), methyl, para-methylamphetamine HCl (PMEA), and naphthalene, 2-(aminopropyl) naphthalene HCl (2-APN) substituents on the phenyl site. Then, we evaluated their abuse potential in the conditioned place preference (CPP) test in mice and self-administration (SA) test in rats. We also investigated the psychostimulant properties of the novel drugs using the locomotor sensitization test in mice. Moreover, we performed qRT-PCR analyses to explore the effects of the novel drugs on the expression of D1 and D2 dopamine receptor genes in the striatum. NBNA, but not EDA, PMEA, and 2-APN, induced CPP and SA in rodents. None of the test drugs have produced locomotor sensitization. qRT-PCR analyses demonstrated that NBNA increased the expression of striatal D1 dopamine receptor genes. These data indicate that NBNA yields rewarding effects, suggesting potential for abuse. Continual observation for the rise of related substances is thus strongly encouraged.

Physicochemical Properties of Insoluble Mineral Substances in Food Additives (식품첨가물중 불용성광물성물질의 물리화학적 특성)

  • Kim, Hee-Yun;Lee, Young-Ja;Hong, Ki-Hyoung;Kwon, Yong-Kwan;Kim, So-Hee;Kim, Hyun-Jong;Lee, Chul-Won;Kim, Kil-Saeng;Lee, Sang-Hoon
    • Korean Journal of Food Science and Technology
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    • v.31 no.5
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    • pp.1188-1195
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    • 1999
  • This study was conducted to determin basic mineral compositions, chemical components, description of particle size distribution and whiteness for 32 items of insoluble mineral substances, i.e., 3 items of diatomaceus earth, 1 item of kaolin, 10 items of bentonite, 13 items of acid clay, 3 items of talc and 2 items of perlite. The chemical components and XRD (X-Ray diffractometer) for insoluble mineral substances, were similar with those of the reported references except kaolin. However, whiteness was determined in 90% level for talc, diatomaceus earth and kaolin. The contents of heavy metals in insoluble mineral substances were determined as follows : Pb, $nd{\sim}23.10$ ppm ; Cd, $nd{\sim}0.67$ ppm ; Hg, $nd{\sim}0.58$ ppm ; As, $nd{\sim}1.42$ ppm ; Cu, $nd{\sim}39.35$ ppm. These data were significanty lower than the references.

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Identification of irradiated soybean with different processing and origin (대두의 가공특성 및 원산지별 조사처리 판별 연구)

  • Jung, Yoo-Kyung;Lee, Hye-Jin;Lee, Ji-Yeon;Choi, Jang-Duck;Kwon, Ki-Sung
    • Korean Journal of Food Science and Technology
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    • v.49 no.3
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    • pp.252-257
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    • 2017
  • In this study, the physicochemical properties of irradiated (gamma-ray and electron-beam) soybeans with different processing (dry and powder) and origins (Korea, China, and USA) were investigated and compared. The results of photostimulated luminescence (PSL) screening indicated that all non-irradiated soybeans showed photon counts (PCs) ${\leq}700$, while all irradiated soybeans showed positive values-gamma-ray 5,815-39,591 count/min; electron beam 5,791-60,055 count/min. The results of thermoluminescence (TL) analysis of all irradiated soybeans indicated that the $TL_1$ glow curves exhibited maximum peaks at 150-250. TL ratio of irradiated samples was ${\geq}0.1$; therefore, the clear identification of irradiated samples was guaranteed by analysis of the $TL_1$ curve shape and TL ratios. The results of electron spin resonance (ESR) signal of 3 irradiated and dried soybeans showed two side peaks mutually spaced at 6.0 mT (cellulose radical). Non-specific signal was detected for all irradiated soybean powders; hence, ESR analysis could not be performed.

Effect of Doenjang (Korean Fermented Soybean Paste) on Lipid Oxidation and Cooking Properties of Pork Patties

  • Oh, Hyun-Ju;Kim, Chang-Soon
    • Food Science and Biotechnology
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    • v.18 no.5
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    • pp.1138-1144
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    • 2009
  • This study was carried out to investigate the cooking properties and lipid oxidation stability during storage at $4{\pm}1^{\circ}C$ when the various levels (5 to 20%) of doenjang (Korean fermented soybean paste) were added to pork patties cooked by pan frying (PF) and convection oven (CO). With increasing the addition of doenjang, cooking properties of pork patties revealed the improved cooking yield, less diameter reduction, and less thickness increase. Also, the shear force, hardness, and chewiness of pork patties were reduced. The PF cooking method showed better cooking properties than CO. Lipid oxidation expressed by the thiobarbituric acid reactive substances (TBARS) values was significantly reduced by the addition of more than 5% doenjang (p<0.05). The TBARS values of cooked pork patties by PF were significantly lower than CO during the 8 days of the storage (p<0.05). The development of warmed-over flavor (WOF) in cooked pork patties was delayed as the amount of the doenjang was increased. It was suggested that the addition of doenjang and PF favorably affected the cooking properties and stability of lipid oxidation in pork patties.

Evaluation of Adequacy of Upper and Lower Tier Qualifying Quantities for the Substance Requiring Preparation for Accidents (사고대비물질 상위 및 하위규정수량의 적정성 평가)

  • Kim, Hyodong;Kim, Haelee;Seo, Cheongmin;Jun, Jinwoo;Park, Kyoshik
    • Journal of the Korean Society of Safety
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    • v.37 no.2
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    • pp.10-17
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    • 2022
  • Currently, in Korea, lower and upper tier qualifying quantities of the 97 substances requiring preparation for accidents have been designated. The information on the submission of chemical accident prevention management plan varies depending on whether the handling volume is above or below the lower or upper qualifying quantity. Because the criteria of the lower and upper qualifying quantities of substance requiring preparation for accidents are not stipulated in the Chemical Substances Control Act, this study attempted to establish a criterion through significance verification. In addition, the study investigated whether these qualifying quantities are related to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), toxic concentration endpoint, and National Fire Protection Association (NFPA). Finally, by comparing the risk categorization of the GHS, endpoint, and NFPA, it was evaluated whether the circulation-volume-based risk categorization of the substance requiring preparation for accidents that are in the top 13 is appropriate. The qualifying quantities of benzene, toluene, and sulfuric acid needed to be adjusted upward, while those of methyl alcohol and ammonia were adjusted downward from the current qualifying quantities. It is required to establish a quantified criterion that fully reflects the domestic situations in Korea and various indicators such as toxicity, physicochemical properties, and circulation volume for the qualified criterion of hazardous chemical substances. The study is expected to be helpful in establishing an efficient system by systematizing the criterion for qualifying quantity.

Isolation and Characterization of Bacillus Strains for Biological Control

  • Kim, Han-Soo;Park, Jiyong;Cho, Sung-Won;Park, Kee-Hyun;Lee, Gung-Pyo;Ban, Soo-Jung;Lee, Chang-Roo;Kim, Chung-Sun
    • Journal of Microbiology
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    • v.41 no.3
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    • pp.196-201
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    • 2003
  • The object of this study was to characterize Bacillus strains GB-017 and GB-0356, which produce antifungal substances, especially for plant pathogens. In addition, this study was undertaken to characterize the culture conditions required for the production of antifungal substances and to document some of the properties of the antifungal substance produced by these soil-isolated strains. Strains GB-0365 and GB-017 were found to be bacillus-shaped, gram-positive and motile, and to inhibit Botrytis cineria, Fusarium sp., Pythium sp., and Rhizoctonia solani. Antagonistic activity was maintained up to pH 9.0, and the antifungal activity was stable to heat at 80$^{\circ}C$ for 1 h. Antifungal substances were separated and purified using ion exchange and adsorption columns including WK-I0(H$\^$+) (pH 7.0), HP20 column (pH 3.0) and IPA (pH 3.0). and IPA. Its UV absorption spectrum showed major peaks at 231 and 259 nm, corresponding to polyene and lactone. A fast atom bombardment mass spectrum (FAB MS) showed a highest peak at 441 m/z and major peaks at 192, 205, and 370 m/z.

Etiological and pathophysiological enigmas of severe coronavirus disease 2019, multisystem inflammatory syndrome in children, and Kawasaki disease

  • Rhim, Jung-Woo;Kang, Jin-Han;Lee, Kyung-Yil
    • Clinical and Experimental Pediatrics
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    • v.65 no.4
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    • pp.153-166
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    • 2022
  • During the coronavirus disease 2019 (COVID-19) pandemic, a novel multisystem inflammatory syndrome in children (MIS-C) has been reported worldwide since the first cases were reported in Europe in April 2020. MIS-C is temporally associated with severe acute respiratory syndrome coronavirus 2 infection and shows Kawasaki disease (KD)-like features. The epidemiological and clinical characteristics in COVID-19, KD, and MIS-C differ, but severe cases of each disease share similar clinical and laboratory findings such as a protracted clinical course, multiorgan involvement, and similar activated biomarkers. These findings suggest that a common control system of the host may act against severe disease insult. To solve the enigmas, we proposed the protein-homeostasis-system hypothesis in that every disease involves etiological substances and the host's immune system controls them by their size and biochemical properties. Also, it is proposed that the etiological agents of KD and MIS-C might be certain strains in the microbiota of human species and etiological substances in severe COVID-19, KD, and MIS-C originate from pathogen-infected cells. Since disease severity depends on the amounts of inflammation-inducing substances and corresponding immune activation in the early stage of the disease, an early proper dose of corticosteroids and/or intravenous immunoglobulin (IVIG) may help reduce morbidity and possibly mortality among patients with these diseases. Corticosteroids are low cost and an analogue of host-origin cortisol among immune modulators. This study's findings will help clinicians treating severe COVID-19, KD, and MIS-C, especially in developing countries, where IVIG and biologics supplies are insufficient.

Effect of Treatment with Ozonated Water on Shelf Life of Refrigerated Meat (오존수 처리가 냉장 쇠고기의 화학적 품질에 미치는 영향)

  • Kim, Min-Ju;Shin, Han-Seung
    • Food Science of Animal Resources
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    • v.31 no.4
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    • pp.617-623
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    • 2011
  • Ozone is a strong oxidant and potent disinfecting agent. In this study, volatile basic nitrogen, thiobarbituric acid reactive substances, acid value and pH all of which are quality indicators in meat products, were evaluated. The meat was treated with the ozonated water (0.2 ppm) for 0, 5, 10, 30, and 60 min and then stored at $5^{\circ}C$ for 24 d. The volatile basic nitrogen content of meat was 22.40 mg% after 9 d of storage and 23.24 mg% at 15 d of storage with ozonated water (0.2 ppm) treatment. During 24 d of storage, the pH, thiobarbituric acid reactive substances, and acid value were decreased when subjected to ozonated water treatment. These results suggested that the ozonated water treatment effectively improved the chemical properties and food safety.

How to Improve the Reliability of MSDS and Labels?(2): A Review on the EU CLP(REGULATION(EC) No 1272/2008) (물질안전보건자료 및 표시제도의 개선 방향 제안(2) - 유럽연합의 CLP 제도 고찰에 근거하여)

  • Kim, Shinbum;Lee, Yun Keun;Choi, Youngeun
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.25 no.2
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    • pp.115-125
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    • 2015
  • Objectives: The major objectives of this study are to review the EU CLP Regulations to propose ways of improving the reliability of MSDS and labels. Methods: To review the EU CLP Regulations, we used EU documents including directives and regulations on chemical management. In addition, we used EU governmental agency reports to illuminate the history and background of the CLP. We found the EU CLP's instruments for reliable hazard communication and evaluated the operations of the instruments. Results: EU CLP Regulations have four instruments for the EU CLP Regulations to make hazard communication reliable. These instruments are GHS, the harmonized CMR and respiratory sensitive substances classification list, C&L inventory and restriction of trade secrets. These are highly useful for achieving the objectives of REACH and CLP(no data-no market and changing the burden of proof). Conclusions: Changing the burden of proof is a key principle for achieving a society safe from hazardous chemicals. Chemical manufacturers and importers alone should bear the responsibility for reliable MSDS. We recommend benchmarking the EU CLP Regulations in order to change efficiently the burden of proof. Trade secrets should be limited to low-hazard substances and be approved by the government before the chemical product is on the market. Like the C&L inventory, chemical product information including substances identification and hazard properties should be notified, aggregated and be opened to public on the Internet. Finally, we recommend a MSDS registration system once again.