• Title/Summary/Keyword: reaction time

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Psychosocial Reaction Patterns to Alopecia in Female Patients with Gynecological Cancer undergoing Chemotherapy

  • Ishida, Kazuko;Ishida, Junko;Kiyoko, Kanda
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.1225-1233
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    • 2015
  • This study aims to clarify the psychosocial reactions of female patients with gynecological cancer undergoing chemotherapy and in the process of suffering from alopecia and to examine their nursing support. The target group comprised female patients who had received two or more cycles of chemotherapy, were suffering from alopecia, and were aged 30-65. Data were collected from semi-structured interviews, conducted from the time the patients were informed by their doctors that they might experience alopecia due to chemotherapy to the time they actually experienced alopecia and until they were able to accept the change. Inductive qualitative analysis was employed to close in on the subjective experiences of the cancer patients. The results showed the existence of six phases in the psychosocial reactions in the process of alopecia: phase one was the reaction after the doctor's explanation; phase two was the reaction when the hair starts to fall out; phase three was the reaction when the hair starts to intensely fall out; phase four was the reaction when the hair has completely fallen out; phase five was the reaction to behavior for coping with alopecia; and phase six was the reaction to change in interpersonal human relationships. The results also made it clear that there are five types of reaction patterns as follows: 1) treatment priority interpersonal relationship maintenance type; 2) alopecia agitated interpersonal relationship maintenance type; 3) alopecia agitated interpersonal relationship reduction type; 4) alopecia denial interpersonal relationship reduction type; and 5) alopecia denial treatment interruption type. It is important to find out which of the five types the patients belong to early during treatment and provide support so that nursing intervention that suits each individual can be practiced. The purpose of this study is to make clear the process in which patients receiving chemotherapy come to accept alopecia and to examine evidence-based nursing care on patients with strong mental distress from alopecia.

Formation and Stabilization of Raphasatin and Sulforaphene from Radish Roots by Endogenous Enzymolysis

  • Kim, Jae-Won;Kim, Mi-Bo;Lim, Sang-Bin
    • Preventive Nutrition and Food Science
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    • v.20 no.2
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    • pp.119-125
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    • 2015
  • The biologically active compounds raphasatin and sulforaphene are formed during the hydrolysis of radishes by an endogenous myrosinase. Raphasatin is very unstable, and it is generated and simultaneously degraded to less active compounds during hydrolysis in aqueous media. This study determined the hydrolysis conditions to maximize the formation of raphasatin and sulforaphene by an endogenous myrosinase and minimize their degradation during the hydrolysis of radish roots. The reaction parameters, such as the reaction medium, reaction time, type of mixing, and reaction temperature were optimized. A stability test for raphasatin and sulforaphene was also performed during storage of the hydrolyzed products at $25^{\circ}C$ for 10 days. The formation and breakdown of raphasatin and sulforaphene in radish roots by endogenous enzymolysis was strongly influenced by the reaction medium, reaction time, and type of mixing. The production and stabilization of raphasatin in radishes was efficient in water and dichloromethane with shaking for 15 min at $25^{\circ}C$. For sulforaphene, the favorable condition was water as the reaction medium without shaking for 10 min at $25^{\circ}C$. The maximum yields of raphasatin and sulforaphene were achieved in a concurrent hydrolysis reaction without shaking in water for 10 min and then with shaking in dichloromethane for 15 min at $25^{\circ}C$. Under these conditions, the yields of raphasatin and sulforaphene were maximized at 12.89 and $1.93{\mu}mol/g$ of dry radish, respectively. The stabilities of raphasatin and sulforaphene in the hydrolyzed products were 56.4% and 86.5% after 10 days of storage in water and dichloromethane at $25^{\circ}C$.

The Antioxidative Effects of Maillard Reaction Mixtures of Oligosaccharides (올리고당의 Maillard 반응물질의 유지에 대한 항산화효과)

  • Lee, Su-Mi;Ahn, Myung-Soo
    • Journal of the Korean Society of Food Culture
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    • v.12 no.2
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    • pp.195-200
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    • 1997
  • The purposes of this study were to investigate the Maillard reactions of some oligosaccharides with lysine and the antioxidative effects of the ethanol extracts from their reaction mixtures on the soybean oil. The Maillard reactions were carried out of 2% oligosaccharides such as palatinose (PN), fructooligosaccharide (FO), isomaltooligosaccharide (IMO) with 2% lysine (L) for 24 hours heating at 60, 80, $100^{\circ}C$. The color intensity of Maillard reaction mixtures were determined by UV-VIS spectrophotometer upon reaction time and temperature. And the antioxidative effects on the soybean oil of each ethanol extract from Maillard reaction mixture of each oligosaccharide were measured by peroxide value (POV). POV's of soybean oil including reaction extracts were determined regularly every 2 days during 20 days storaged at $60{\pm}1^{\circ}C$. The results were obtained as follows: 1. The color intensity of the Maillard reaction mixtures were raised highly as the browning temperature and time increased. The color intensity of PN L browning mixture was the highest. The order of high color intensity at $100^{\circ}C$ was PN L>FO L>Glu L>IMO L. 2. Comparing the antioxidative effect of Maillard reaction product (at $100^{\circ}C$, for 12 hours) of each oligosaccharide to that of BHT and TBHQ, the order of high antioxidative effect was TBHQ>IMO L>BHT>Glu L>PN L>FO L. 3. From these results, it was known that PN L shown as high brown color intensity was appeared low antioxidative effect, while IMO L shown as low brown color intensity was appeared high antioxidative effect. So, it was recognized that there was no relation between brown color intensity and antioxidative effect.

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Reaction Condition for Biodiesel Production from Animal Fats (동물성 유지를 이용한 바이오디젤 생산의 반응조건)

  • Yang, Hee-Seung;Jeong, Gwi-Taek;Park, Suk-Hwan;Park, Jae-Hee;Park, Don-Hee
    • KSBB Journal
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    • v.22 no.4
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    • pp.228-233
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    • 2007
  • The high cost and lack of vegetable oil are limiting the expansion of biodiesel production. The purpose of research was to investigate the potential of animal fats as biodiesel feedstock. In this paper, transesterification using alkali catalyst and methanol was performed to reaction, we carried out experiments that it was changed variables as reaction temperature, methanol molar ratio, catalyst types, amount of catalyst and reaction time. The optimum reaction condition for biodiesel production was reaction temperature 65$^{\circ}C$, potassium hydroxide 1.0% (w/w), oil to methanol molar ratio 1:15 and reaction time 20 min. In this reaction condition, the contents of fatty acid methyl ester was reached to about 98.7%. Also, properties of biodiesel were measured to correspond to domestic quality standard of acid values, density and viscosity.

The Improved Synthesis of 1-Chloro-2-iodoperfluorocycloalkenes and 2,2'-Dichloroperfluorocycloalkenyls (1-Chloro-2-iodoperfluorocycloalkenes와 2,2'-Dichloroperfluorocycloalkenyls 합성의 개량)

  • Sam Kwon Choi;Jeseph D. Park
    • Journal of the Korean Chemical Society
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    • v.21 no.3
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    • pp.180-186
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    • 1977
  • The preparation of 1-chloro-2-iodoperfluorocycloalkenes was achieved with a short reaction time and a high yield when the starting compound was iodinated via the metalation process using an alkyllithium reagent. Especially, the high yield of 1-chloro-2-iodo-perfluorocyclohexene was obtained when 1,2-dichloroperfluorocyclohexene was iodinated via the same reaction conditions. The coupling reaction of 1,2-dihaloperfluorocycloalkenes was also achieved with a lower reaction temperature and a shorter reaction time when the equal slurry mixture of fluorocycloolefines and DMF was reacted at a high pressure in a sublimer. The yield of the coupling product was greatly improved by this process. For a typical example, the coupling reaction of the 1-chloro-2-iodotetrafluorocyclobutene was proceeded with a higher yield of the product than that of the reported reaction, when the present method was adopted. A plausible reaction mechanism of the present coupling reactiont was proposed and the physical characteristics of the coupling product were confirmed.

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Production of Chemical Intermediate Furfural from Renewable Biomass Miscanthus Straw (재생가능한 바이오매스 자원인 억새로부터 화학중간체 푸르프랄의 생산)

  • Jeong, Gwi-Taek
    • Korean Chemical Engineering Research
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    • v.52 no.4
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    • pp.492-496
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    • 2014
  • In this work, the possibility of Miscanthus as renewable lignocellulosic biomass was evaluated for production of furfural. Also, to find the reaction conditions of furfural production from Miscanthus straw, the effects of solid-to-liquid ratio, reaction temperature, catalyst amount, and reaction time were investigated. Finally, 5.1 g/L furfural was produced from Miscanthus straw in the condition of solid-to-liquid ratio at 1:10, reaction temperature at $150^{\circ}C$, sulfuric acid at 3%, and reaction time of 60 minutes. This result will provide basic knowledge for converting renewable resources into valuable chemicals substituted for fossil fuels.

Response Surface Methodological Approach for Optimization of Enzymatic Synthesis of Sorbitan Methacrylate

  • Jeong, Gwi-Taek;Lee, Kyoung-Min;Kim, Hae-Sung;Lee, Woo-Tai;Sunwoo, Chang-Shin;Park, Don-Hee
    • 한국생물공학회:학술대회논문집
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    • 2005.10a
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    • pp.511-516
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    • 2005
  • Sorbitan methacrylate was synthesized from sorbitan dehydrated from D-sorbitol using an immobilized lipase. To optimize the enzymatic synthesis of sorbitan methacrylate, response surface methodology was applied to determine the effects of five-level-four-factors and their reciprocal interactions on sorbitan methacrylate biosynthesis. A total of 30 individual experiments were performed, which were designed to study reaction temperature, reaction time, enzyme amount and substrate molar ratio. A statistical model predicted that the highest conversion yield of sorbitan methacrylate was 100%, at the following optimized reaction conditions: a reaction temperature of 43.06 $^{\circ}C$, a reaction time of 164.25 mins., an enzyme amount of 7.47%, and a substrate molar ratio of 3.98:1. Using these optimal factor values under experimental conditions in four independent replicates, the average conversion yield reached 98.7%${\pm}$1.2% and was well within the value predicted by the model.

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Response Surface Methodological Approach for Optimization of Removal of Free Fatty Acid in Crude Oil

  • Jeong, Gwi-Taek;Lee, Kyoung-Min;Yang, Hee-Seung;Park, Seok-Hwan;Kim, Jae-Hoon;Kim, Do-Man;Park, Don-Hee
    • 한국생물공학회:학술대회논문집
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    • 2005.10a
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    • pp.904-909
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    • 2005
  • To optimize the removal of free fatty acid in crude vegetable oil, response surface methodology was applied to determine the effects of five level-four factors and their reciprocal interactions on removal of free fatty acid. A total of 30 individual experiments were performed, which were designed to study reaction temperature, reaction time, catalyst amount and methanol amount. A statistical model predicted that the highest removal yield of free fatty acid was 99.8%, at the following optimized reaction conditions: a reaction temperature of 64.99$^{\circ}C$, a reaction time of 36.20 mins., an catalyst amount of 13.01% (w/v), and a methanol amount of 15% (v/v). Using these optimal factor values under experimental conditions in three independent replicates, the average removal yield was well within the value predicted by the model.

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Pyrolysis Reaction for the Treatment of Hazardous Halogenated Hydrocarbon Waste (유해 할로겐화 탄화수소 폐기물 처리를 위한 열분해 반응)

  • 조완근
    • Journal of Environmental Science International
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    • v.6 no.4
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    • pp.399-407
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    • 1997
  • The pyrolysis reactions of atomic hydrogen with chloroform were studied In a 4 cm 1.6. tubular flow reactor with low flow velocity 1518 cm/sec and a 2.6 cm 1.4. tubular flow reactor with high flow velocity (1227 cm/sec). The hydrogen atom concentration was measured by chemiluminescence titration with nitrogen dioxide, and the chloroform concentrations were determined using a gas chromatography. The chloroform conversion efficiency depended on both the chloroform flow rate and linear flow velocity, but 416 not depend on the flow rate of hydrogen atom. A computer model was employed to estimate a rate constant for the initial reaction of atomic hydrogen with chloroform. The model consisted of a scheme for chloroform-hydrogen atom reaction, Runge-Kutta 4th-order method for Integration of first-order differential equations describing the time dependence of the concentrations of various chemical species, and Rosenbrock method for optimization to match model and experimental results. The scheme for chloroform-hydrogen atom reaction Included 22 elementary reactions. The rate constant estimated using the data obtained from the 2.6 cm 1.4. reactor was to be 8.1 $\times$ $10^{-14}$ $cm^3$/molecule-sec and 3.8 $\times$ $10^{-15}$ cms/molecule-sec, and the deviations of computer model from experimental results were 9% and 12% , for the each reaction time of 0.028 sec and 0.072 sec, respectively.

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Synthesis of polyphenylcarbosilane via thermal rearrangement of polymethylphenylsilane in supercritical cyclohexane

  • Shin, Hee-Yong;Ryu, Jae-Hun;Bae, Seong-Youl;Lee, Yoon-Joo;Kwon, Woo-Teck;Kim, Young-Hee;Kim, Soo-Ryong
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.1
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    • pp.9-15
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    • 2013
  • A new process for the synthesis of polyphenylcarbosilane (PPCS) via thermal rearrangement of polymethylphenylsilane (PMPS) in supercritical cyclohexane was proposed and investigated at reaction temperatures of $380-420^{\circ}C$, reaction times of 1-2 h, and a pressure of 15 MPa. The structure, molecular weight, and molecular weight distribution of the product were characterized by FT-IR, Si-NMR, and GPC. The ceramic yield was also measured by TGA analysis. High-quality PPCS with high molecular weight and ceramic yield can be synthesized via a supercritical process. Furthermore, this process, when compared to the conventional method, tends to moderate the reaction conditions such as reaction temperature and time. It is concluded that thermal rearrangement in supercritical fluid is an efficient and viable process in terms of the resulting yield, efficiency, and reaction time compared with those of the conventional PCS production process.