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Pharmacological Studies of Cefoperazone(T-1551) (Cefoperazone(T-1551)의 약리학적 연구)

  • Lim J.K.;Hong S.A.;Park C.W.;Kim M.S.;Suh Y.H.;Shin S.G.;Kim Y.S.;Kim H.W.;Lee J.S.;Chang K.C.;Lee S.K.;Chang K.C.;Kim I.S.
    • The Korean Journal of Pharmacology
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    • v.16 no.2 s.27
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    • pp.55-70
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    • 1980
  • The pharmacological and microbiological studies of Cefoperazone (T-1551, Toyama Chemical Co., Japan) were conducted in vitro and in vivo. The studies included stability and physicochemical characteristics, antimicrobial activity, animal and human pharmacokinetics, animal pharmacodynamics and safety evaluation of Cefoperazone sodium for injection. 1) Stability and physicochemical characteristics. Sodium salt of cefoperazone for injection had a general appearance of white crystalline powder which contained 0.5% water, and of which melting point was $187.2^{\circ}C$. The pH's of 10% and 25% aqueous solutions were 5.03 ana 5.16 at $25^{\circ}C$. The preparations of cefoperazone did not contain any pyrogenic substances and did not liberate histamine in cats. The drug was highly compatible with common infusion solutions including 5% Dextrose solution and no significant potency decrease was observed in 5 hours after mixing. Powdered cefoperazone sodium contained in hermetically sealed and ligt-shielded container was highly stable at $4^circ}C{\sim}37^{\circ}C$ for 12 weeks. When stored at $4^{\circ}C$ the potency was retained almost completely for up to one year. 2) Antimicrobial activity against clinical isolates. Among the 230 clinical isolates included, Salmonella typhi was the most susceptible to cefoperazone, with 100% inhibition at MIC of ${\leq}0.5{\mu}g/ml$. Cefoperazone was also highly active against Streptococcus pyogenes(group A), Kletsiella pneumoniae, Staphylococcus aureus and Shigella flexneri, with 100% inhibition at $16{\mu}g/ml$ or less. More than 80% of Escherichia coli, Enterobacter aerogenes and Salmonella paratyphi was inhibited at ${\leq}16{\mu}/ml$, while Enterobacter cloaceae, Serratia marcescens and Pseudomonas aerogenosa were somewhat less sensitive to cefoperagone, with inhibitions of 60%, 55% and 35% respectively at the same MIC. 3) Animal pharmacokinetics Serum concentration, organ distritution and excretion of cefoperazone in rats were observed after single intramuscular injections at doses of 20 mg/kg and 50 mg/kg. The extent of protein binding to human plasma protein was also measured in vitro br equilibrium dialysis method. The mean Peak serum concentrations of $7.4{\mu}g/ml$ and $16.4{\mu}/ml$ were obtained at 30 min. after administration of cefoperazone at doses of 20 mg/kg and 50 mg/kg respectively. The tissue concentrations of cefoperazone measured at 30 and 60 min. were highest in kidney. And the concentrations of the drug in kidney, liver and small intestine were much higher than in blood. Urinary and fecal excretion over 24 hours after injetcion ranged form 12.5% to 15.0% in urine and from 19.6% to 25.0% in feces, indicating that the gastrointestinal system is more important than renal system for the excretion of cefoperazone. The extent of binding to human plasma protein measured by equilibrium dialysis was $76.3%{\sim}76.9%$, which was somewhat lower than the others utilizing centrifugal ultrafiltration method. 4) Animal pharmacodynamics Central nervous system : Effects of cefoperazone on the spontaneous movement and general behavioral patterns of rats, the pentobarbital sleeping time in mice and the body temperature in rabbits were observed. Single intraperitoneal injections at doses of $500{\sim}2,000mg/kg$ in rats did not affect the spontaneous movement ana the general behavioral patterns of the animal. Doses of $125{\sim}500mg/kg$ of cefoperazone injected intraperitonealy in mice neither increased nor decreased the pentobarbital-induced sleeping time. In rabbits the normal body temperature was maintained following the single intravenous injections of $125{\sim}2,000mg/kg$ dose. Respiratory and circulatory system: Respiration rate, blood pressure, heart rate and ECG of anesthetized rabbits were monitored for 3 hours following single intravenous injections of cefoperazone at doses of $125{\sim}2,000mg/kg$. The respiration rate decreased by $3{\sim}l7%$ at all the doses of cefoperazone administered. Blood pressure did not show any changes but slight decrease from 130/113 to 125/107 by the highest dose(2,000 mg/kg) injected in this experiment. The dosages of 1,000 and 2,000 mg/kg seemed to slightly decrease the heart rate, but it was not significantly different from the normal control. All the doses of cefoperazone injected were not associated with any abnormal changes in ECG findings throughout the monitering period. Autonomic nervous system and smooth muscle: Effects of cefoperazone on the automatic movement of rabbit isolated small intestine, large intestine, stomach and uterus were observed in vitro. The autonomic movement and tonus of intestinal smooth muscle increased at dose of $40{\mu}g/ml$ in small intestine and at 0.4 mg/ml in large intestine. However, in stomach and uterine smooth muscle the autonomic movement was slightly increased by the much higher doses of 5-10 mg/ml. Blood: In vitro osmotic fragility of rabbit RBC suspension was not affected by cefoperazone of $1{\sim}10mg/ml$. Doses of 7.5 and 10 mg/ml were associated with 11.8% and 15.3% prolongation of whole blood coagulation time. Liver and kidney function: When measured at 3 hours after single intravenous injections of cefoperaonze in rabbits, the values of serum GOT, GPT, Bilirubin, TTT, BUN and creatine were not significantly different from the normal control. 5) Safety evaluation Acute toxicity: The acute toxicity of cefoperazone was studied following intraperitoneal and intravenous injections to mice(A strain, 4 week old) and rats(Sprague-Dawler, 6 week old). The LD_(50)'s of intraperitonealy injected cefoperazone were 9.7g/kg in male mice, 9.6g/kg in female mice and over 15g/kg in both male and female rats. And when administered intravenously in rats, LD_(50)'s were 5.1g/kg in male and 5.0g/kg in female. Administrations of the high doses of the drug were associated with slight inhibition of spontaneous movement and convulsion. Atdominal transudate and intestinal hyperemia were observed in animals administered intraperitonealy. In rats receiving high doses of the drug intravenously rhinorrhea and pulmonary congestion and edema were also observed. Renal proximal tubular epithelial degeneration was found in animals dosing in high concentrations of cefoperazone. Subacute toxicity: Rats(Sprague-Dawley, 6 week old) dosing 0.5, 1.0 and 2.0 g/kg/day of cefoperazone intraperitonealy were observed for one month and sacrificed at 24 hours after the last dose. In animals with a high dose, slight inhibition of spontaneous movement was observed during the experimental period. Soft stool or diarrhea appeared at first or second week of the administration in rats receiving 2.0g/kg. Daily food consumption and weekly weight gain were similar to control during the administration. Urinalysis, blood chemistry and hematology after one month administration were not different from control either. Cecal enlargement, which is an expected effect of broad spectrum antibiotic altering the normal intestinal microbial flora, was observed. Intestinal or peritoneal congestion and peritonitis were found. These findings seemed to be attributed to the local irritation following prolonged intraperitoneal injections of hypertonic and acidic cefoperazone solution. Among the histopathologic findings renal proximal tubular epithelial degeneration was characteristic in rats receiving 1 and 2g/kg/day, which were 10 and 20 times higher than the maximal clinical dose (100 mg/kg) of the drug. 6) Human pharmacokinetics Serum concentrations and urinary excretion were determined following a single intravenous injection of 1g cefoperazone in eight healthy, male volunteers. Mean serum concentrations of 89.3, 61.3, 26.6, 12.3, 2.3, and $1.8{\mu}g/ml$ occured at 1,2,4,6,8 and 12 hours after injection respectively, and the biological half-life was 108 minutes. Urinary excretion over 24 hours after injection was up to 43.5% of administered dose.

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Synthesis and Phase Relations of Potassium-Beta-Aluminas in the Ternary System K2O-MgO-Al2O3 (K2O-MgO-Al2O3 3성분계에서 K+-β/β"-Al2O3의 합성 및 상관계)

  • Ham, Choul-Hwan;Lim, Sung-Ki;Lee, Chung-Kee;Yoo, Seung-Eul
    • Applied Chemistry for Engineering
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    • v.10 no.7
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    • pp.1086-1091
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    • 1999
  • $K^+-{\beta}/{\beta}"-Al_2O_3$ in the ternary system $K_2O-MgO-Al_2O_3$ was directly synthesized by solid state reaction. The phase formation and phase relation were carefully investigated in relation to starting composition, calcining temperature and time, and dispersion medium. The optimal synthetic condition was also examined for the formation of ${\beta}"-Al_2O_3$ phase with a maximum fraction. As a composition range, the mole ratio of $K_2O$ to $Al_2O_3$ was changed from 1:5 to 1:6.2 and the amount of MgO used as a stabilizer was varied from 4.2 wt % to 6.3 wt %. The calcining temperature was selected between $1000^{\circ}C$ and $1500^{\circ}C$. At $1000^{\circ}C$, the ${\beta}/{\beta}"-Al_2O_3$ phases began to form resulted from the combining of ${\alpha}-Al_2O_3$ and $KAlO_2$ and increased with temperature rising. All of ${\alpha}-Al_2O_3$ phase disappeared to be homogenized to the ${\beta}/{\beta}"-Al_2O_3$ phase at $1200^{\circ}C$. Near the temperature at $1300^{\circ}C$, the fraction of ${\beta}"-Al_2O_3$ phase showed a maximum value with the composition of $K_{1.67}Mg_{0.67}Al_{10.33}O_{17}$. At temperatures above $1300^{\circ}C$, the fraction of ${\beta}"-Al_2O_3$ phase decreased gradually owing to $K_2O$ loss caused by a high potassium vapor pressure, and the appropriate calcining time was about 5 hours. Acetone was more effective than distilled water as a dispersion medium for milling and mixing.

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Coupled T-H-M Processes Calculations in KENTEX Facility Used for Validation Test of a HLW Disposal System (고준위 방사성 폐기물 처분 시스템 실증 실험용 KENTEX 장치에서의 열-수리-역학 연동현상 해석)

  • Park Jeong-Hwa;Lee Jae-Owan;Kwon Sang-Ki;Cho Won-Jin
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.4 no.2
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    • pp.117-131
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    • 2006
  • A coupled T-H-M(Thermo-Hydro-Mechanical) analysis was carried out for KENTEX (KAERI Engineering-scale T-H-M Experiment for Engineered Barrier System), which is a facility for validating the coupled T-H-M behavior in the engineered barrier system of the Korean reference HLW(high-level waste) disposal system. The changes of temperature, water saturation, and stress were estimated based on the coupled T-H-M analysis, and the influence of the types of mechanical constitutive material laws was investigated by using elastic model, poroelastic model, and poroelastic-plastic model. The analysis was done using ABAQUS, which is a commercial finite element code for general purposes. From the analysis, it was observed that the temperature in the bentonite increased sharply for a couple of days after heating the heater and then slowly increased to a constant value. The temperatures at all locations were nearly at a steady state after about 37.5 days. In the steady state, the temperature was maintained at $90^{\circ}C$ at the interface between the heater and the bentonite and at about $70^{\circ}C$ at the interface between the bentonite and the confining cylinder. The variation of the water saturation with time in bentonite was almost same independent of the material laws used in the coupled T-H-M processes. By comparing the saturation change of T-H-M and that of H-M(Hydro-Mechanical) processes using elastic and poroelastic material mod31 respectively, it was found that the degree of saturation near the heater from T-H-M calculation was higher than that from the coupled H-M calculation mainly because of the thermal flux, which seemed to speed up the saturation. The stresses in three cases with different material laws were increased with time. By comparing the stress change in H-M calculation using poroelasetic and poroelasetic-plastic model, it was possible to conclude that the influence of saturation on the stress change is higher than the influence of temperature. It is, therefore, recommended to use a material law, which can model the elastic-plastic behavior of buffer, since the coupled T-H-M processes in buffer is affected by the variation of void ratio, thermal expansion, as well as swelling pressure.

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Flexural Properties according to Change of Polymerization Temperature of Autopolymerized Resin for Orthodontic (치과 교정용 자가중합형 Resin의 중합 온도 변화에 따른 굽힘 특성)

  • Lee, Gyu Sun
    • Journal of dental hygiene science
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    • v.15 no.3
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    • pp.259-264
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    • 2015
  • For this experiment, specimen was manufactured by injecting polymer and monomer into silicon mold with volume ratio of 2.5:1 based on ISO 20795-2 so that average thickness, width and length of specimen would be maintained as 3.3 mm, 10.0 mm and 65.0 mm, respectively depending on spray on technique. Specimen was divided into 3 groups ($25^{\circ}C$, $40^{\circ}C$, $70^{\circ}C$) depending on polymerization temperature and 10 specimen was manufactured for each group and it was polymerized in water tank of ${\pm}1^{\circ}C$ under the setting condition of polymerization time of 15 minutes and pressure of 3 bar. After keeping specimen in distilled water of $37^{\circ}C$ for over 48 hours before experiment, flexural strength (FS) and elasticity modulus (EM) of specimen being tested by using Intron (3344; Instron; Instron). SPSS ver. 16.0 was used for analysis and post-hoc test of Scheffe was performed after using one-way ANOVA. When comparing mean value of FS of resin for orthodontics, it was represented in the range of 71.500 MPa for $25^{\circ}C$ group, 74.920 MPa for $40^{\circ}C$ group and 76.880 MPa for $70^{\circ}C$ group and difference was shown in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group but such difference was not significant statistically (p=0.052). Result of EM mean value of resin for orthodontics was more polymerization temperature was high, the more was significant difference represented in the order of $25^{\circ}C$ group <$40^{\circ}C$ group <$70^{\circ}C$ group (p<0.039).

Studies on the Pulping Characteristics of Larchwood (Larix leptolepis Gordon) by Alkaline Process with Additives (첨가제(添加劑) 알칼리 법(法)에 의한 일본 잎갈 나무의 펄프화(化) 특성(特性)에 관(關)한 연구(硏究))

  • Lim, Kie-Pyo;Shin, Dong-Sho
    • Journal of the Korean Wood Science and Technology
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    • v.7 no.2
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    • pp.3-30
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    • 1979
  • Larch ($\underline{Larix}$ $\underline{leptolepis}$ GORDON), one of the major afforestation species in Korea in view of its growing stock and rate of growth, is not favored as a raw material for pulp due to its low yield of pulp and difficulties with bleaching arising from the high content of extractives in wood, and the high heartwood ratio and the active phenolics, respectively. The purpose of this study is to investigate the characteristics of firstly pulping with various additives of cellulose protector for the yield of pulp, and secondly bleaching with oxygen for chlotination-alkali extraction of five stage-sequence to reduce chlorine compounds in bleaching effluents. The kraft cooking liquor for five age groups of larchwood was 18 percent active alkali with 25 percent sulfidity and 5 : 1 liquor-to-wood ratio, and each soda liquor for sap-and heart-wood of the 15-year-old larchwood was 18 percent alkali having one of the following cellulose protectors as the additive; magnesium sulfate ($MgSO_4$, 2.5%), zinc sulfate ($ZnSO_4$, 2.5%), aluminium sulfate ($Al_2(SO_4)_3$, 2.5%), potasium iodide (KI, 2.5%), hydroquinone (HQ, 2.5%), anthraquinone (AQ, 0.1%) and ethylene diamine (EDA, 2.5%). Then each anthraquinone-soda liquor for the determination of suitable cooking condition was the active alkali level of 15, 17 and 19 percent with 1.0, 0.5 and 0.1 percent anthraquinone, respectively. The cooking procedure for the pulps was scheduled to heat to 170$^{\circ}C$ in 90 minutes and to cook 90 minutes at the maximum temperature. The anthraquinone-soda pulps from both heartwood and sapwood of 15-year-old larchwood prepared with 0.5 percent anthraquinone and 18 percent active alkali were bleached in a four-stage sequency of OCED. (O: oxygen bleaching, D: chlorine dioxide bleaching and E: alkali extraction). In the first stage oxygen in atmospheric pressure was applied to a 30 percent consistency of pulp with 0.1 percent magnesium oxide (MgO) and 3, 6, and 9 percent sodium hydroxide on oven dry base, and the bleached results were compared pulps bleached under the conventional CEDED (C: chlorination). The results in the study were summarized as follows: 1. The screened yield of larch kraft pulp did not differ from particular ages to age group, but heartwood ratio, basic density, fiber length and water-extractives contents of wood and the tear factor of the pulp increased with increasing the tree age. The total yield of the pulp decreased. 2. The yield of soda pulp with various chemicals for cellulose protection of the 15-year-old larchwood increased slightly more than that of pure soda pulp and was slightly lower than that of kraft pulp. The influence of cellulose protectors was similar to the yield of pulps from both sapwood and heartwood. The effective protectors among seven additives were KI, $MgSO_4$ and AQ, for which the yields of screened pulp was as high as that of kraft pulp. Considering the additive level of protector, the AQ was the most effective in improving the yield and the quality of pulp. 3. When the amount of AQ increased in soda cooking, the yield and the quality of the pulp increased but rejects in total yield increased with decreasing the amount of active alkali from 19 to 15 percent. The best proportion of the AQ seemed to be 0.5 percent at 17 percent active alkali in anthraquinone-soda pulping. 4. On the bleaching of the AQ-soda pulp at 30 percent consistency with oxygen of atomospheric pressure in the first stage of the ODED sequence, the more caustic soda added, the brighter bleached pulp was obtained, but more lignin-selective bleaching reagent in proportion to the oxygen was necessary to maintain the increased yield with the addition of anthraquinone. 5. In conclusion, the suitable pulping condition for larchwood to improve the yield and quality of the chemical pulp to the level for kraft pulp from conventional process seemed to be. A) the selection of young larchwood to prevent decreasing in yield and quality due to the accumulation extractives in old wood, B) the application of 0.5 percent anthraquinone to the conventional soda cooking of 18 percent active alkali, and followed, C) the bleaching of oxygen in atmospheric pressure on high consistency (30%) with 0.1 percent magnesium oxide in the first stage of the ODED sequence to reduce the content of chlorine compounds in effluent.

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A STUDY ON THE DEGREE OF POLYMERIZATION OF AUTOPOLYMERIZED RESIN FOR REMOVABLE ORTHODONTIC APPLIANCE ACCORDING TO CURING TIME AND CURING METHOD (중합시간과 중합방법에 따른 자가중합형 상교정용 레진의 중합률의 비교에 관한 연구)

  • Yoo, Jong-Wook;Jang, Ki-Taeg;Kim, Chong-Chul
    • Journal of the korean academy of Pediatric Dentistry
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    • v.26 no.2
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    • pp.296-309
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    • 1999
  • Autopolymerized resin facilitates a more rapid and easier means for the construction of removable orthodontic appliances than heat cured resin. But many reports reveal that more unreacted monomer is found in autopolymerized resin. It is very important to achieve maximum degree of polymerization because if polymerization is inadequate, high level of unreacted monomer has been shown to adversely affect mechanical and physical properties, and also the question of allergy or toxicity to methylmethacrylate must be considered. The purpose of this study was to compare the degree of polymerization according to curing method and curing time. Five groups were desinged ; Group 1 was polymerizied at room temperature($28^{\circ}C$) ; Group 2 in $28^{\circ}C$ water ; Group 3 in $28^{\circ}C$ water under 30psi pressure ; Group 4 in $43^{\circ}C$ water ; Group 5 in $43^{\circ}C$ water under 30psi pressure for 10 minutes, 1 hour 12 hours, 1 day and 3 days. The degree of polymerization was measured by means of Fourier Transform Infrared spectroscopy. The results were as follows: 1. The degree of polymerization increased constantly in accordance with curing time in all groups and after curing for 10 minutes, Group 1 showed significantly higher degree of polymerization after 12 hours and Group 2, Group 3, Group 4, Group 5 after 1 hour(p<0.05). 2. The degree of polymerization decreased in the order of Group 5, Group 4, Group 3, Group 2, Group 1 except when the curing time was 1 hour and 12 hours(p<0.05). 3. The degree of polymerization of Group 4, Group 5 cured at $43^{\circ}C$ showed significantly higher degree of polymerization than Group 2, Group 3 at $28^{\circ}C$ except when the curing time was 1 day(p<0.05). 4. Among Group 2, Group 3 and Group 4, Group 5, the pressure had no effect on polymerization except when the curing time was 12 hours(p<0.05). 5. Between Group 1 and Group 2, the method of storage had no effect on polymerization except when the curing time was 1 hour(p<0.05).

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Effect of Recovery of Pulmonarv Function in Hypothermic Lung Preservation (폐의 저량보존법이 폐기능 회복에 미치는 영향)

  • Lee, Man-Bok;Kim, U-Jong;Gang, Chang-Hui;Lee, Gil-No
    • Journal of Chest Surgery
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    • v.30 no.3
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    • pp.253.1-262
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    • 1997
  • Hypothermia during lung preservation decreases metabolic processes. After the rabbit lung was flushed with modified Euro-Collins solution, heart-lung block was harvested and the left lung was assessed after ligation of the right pulmonary artery and right main-stem bronchus. Heart-lung block was immersed in the same solution for 6 hours. The modified Euro-Collins solution and storage temperature of group 1(10 cases) was 4t, roup 2(10 cases) was l$0^{\circ}C$. On completion of the storage period, the left lung was ventilated and reperfused with blood u:high used a cross-circulating paracorporeal rabbit as a "biologic deoxygenator" for 60 minutes. Pulmonary artery pressure, airway pressure, difference in oxygen tension between mow and outflow perfusate and degree of pulmonary edema were assessed at 10-minute intervals while the left lung was ventilated at 0.8 of the inspired oxygen fraction. The mean pulmonary venous oxygen tensions at 10 and 60 minutes after reperfusion were 209.52$\pm$42.46 and 103.48$\pm$ 15.96 mmHg in group I versus 247.78$\pm$36.19 and 147.91 $\pm$ 11.07 mmHg in group II(p=0.049, (0.0001). The mean alveolar-arterial oxygen differences at 20 and 60 minutes after reperfusion were 357. 95$\pm$ 12.84 and 437.31 14.26 mmHg in group I versus 310.88$\pm$3).47 and )90.93$\pm$ 15.86 mmHg in group II (p=0.0092, (0.0001). The mean pulmonary arterial pressures at 10 and 60 minutes after reperfusion were 40.56$\pm$ 18.66 and 87. 2$\pm$ 17.22 mmHg in group I versus 31.22$\pm$6.84 and 65.78$\pm$ 11.02 mmHg in group rl (p : 0.048, 0.0062). The mean pulmonary vascular resistances at 10 and 60 minutes after reperfusion were 2.69$\pm$0.85 and 4.36$\pm$0.86 mmHg/ml/min in group I versus 1.99$\pm$0.39 and 3.29$\pm$0.55 mmHg/ml/min in group II(p : 0.0323, 0.0062). There were no difference between groups in peak airway pressure, lung compliance and degree of pulmonary edema. In conclusion that preservation of lung at l$0^{\circ}C$ was superior to preservation at 4$^{\circ}C$.}C$.

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A Comprehensive Review of Geological CO2 Sequestration in Basalt Formations (현무암 CO2 지중저장 해외 연구 사례 조사 및 타당성 분석)

  • Hyunjeong Jeon;Hyung Chul Shin;Tae Kwon Yun;Weon Shik Han;Jaehoon Jeong;Jaehwii Gwag
    • Economic and Environmental Geology
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    • v.56 no.3
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    • pp.311-330
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    • 2023
  • Development of Carbon Capture and Storage (CCS) technique is becoming increasingly important as a method to mitigate the strengthening effects of global warming, generated from the unprecedented increase in released anthropogenic CO2. In the recent years, the characteristics of basaltic rocks (i.e., large volume, high reactivity and surplus of cation components) have been recognized to be potentially favorable in facilitation of CCS; based on this, research on utilization of basaltic formations for underground CO2 storage is currently ongoing in various fields. This study investigated the feasibility of underground storage of CO2 in basalt, based on the examination of the CO2 storage mechanisms in subsurface, assessment of basalt characteristics, and review of the global research on basaltic CO2 storage. The global research examined were classified into experimental/modeling/field demonstration, based on the methods utilized. Experimental conditions used in research demonstrated temperatures ranging from 20 to 250 ℃, pressure ranging from 0.1 to 30 MPa, and the rock-fluid reaction time ranging from several hours to four years. Modeling research on basalt involved construction of models similar to the potential storage sites, with examination of changes in fluid dynamics and geochemical factors before and after CO2-fluid injection. The investigation demonstrated that basalt has large potential for CO2 storage, along with capacity for rapid mineralization reactions; these factors lessens the environmental constraints (i.e., temperature, pressure, and geological structures) generally required for CO2 storage. The success of major field demonstration projects, the CarbFix project and the Wallula project, indicate that basalt is promising geological formation to facilitate CCS. However, usage of basalt as storage formation requires additional conditions which must be carefully considered - mineralization mechanism can vary significantly depending on factors such as the basalt composition and injection zone properties: for instance, precipitation of carbonate and silicate minerals can reduce the injectivity into the formation. In addition, there is a risk of polluting the subsurface environment due to the combination of pressure increase and induced rock-CO2-fluid reactions upon injection. As dissolution of CO2 into fluids is required prior to injection, monitoring techniques different from conventional methods are needed. Hence, in order to facilitate efficient and stable underground storage of CO2 in basalt, it is necessary to select a suitable storage formation, accumulate various database of the field, and conduct systematic research utilizing experiments/modeling/field studies to develop comprehensive understanding of the potential storage site.

Quality characteristics and antioxidant activity of onion peel extracts by extraction methods (추출방법에 따른 양파껍질 추출물의 품질특성 및 항산화활성 비교)

  • Jeong, Da-Som;Back, Da-Ae;Kwon, Yu-Ri;Kwon, Gi-Man;Youn, Kwang-Sup
    • Food Science and Preservation
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    • v.22 no.2
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    • pp.267-274
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    • 2015
  • This study was conducted to evaluate the antioxidant activities and the quality characteristics of 70% ethanol extracts from onion peels with different extraction methods (autoclave extraction, AE; low temperature high pressure extraction, LTPE; reflux extraction, RE; and stirrer extraction, SE). The yields of AE, LTPE, RE and SE were 9.00%, 5.39%, 13.21% and 12.41%, respectively. The total polyphenol and flavonoid contents in the AE were significantly higher than in the other extracts. The DPPH radical scavenging abilities with a concentration of 100 mg% (w/v) were : AE, 28.9%; RE, 26.07%; LTPE, 24.35%; and SE, 19.53%. The ABTS radical scavenging ability and the nitrite scavenging activity showed the same tendency as that of the DPPH radical scavenging ability. The angiotensin-converting enzyme (ACE) inhibitory activities of the LTPE and AE were higher than those of the RE and SE. The ${\alpha}$-Glucosidase inhibitory activity of the RE was higher than that of the extracts with other extraction methods. The nitrite scavenging activities with a concentration of 10 mg/mL were: AE. 33.97%; RE, 35.47%; LTPE, 21.86%; and SE, 21.71%. The ferrous ion chelating activity of the LTPE (54.73%) was significantly higher than that of the other extracts. These results suggest that AE is the superior method for the enhancement of anti-oxidant activity, and onion peel can be used as a natural antioxidant material for health foods and can be a good ingredient of functional foods.

The Simultaneous Absorption Rate of CO2/SO2/NO2 from Flue Gas with Aqueous Alkanolamine Solutions (알카놀아민 수용액을 이용한 연소배가스 중의 CO2/SO2/NO2 동시 흡수속도에 관한 연구)

  • Seo, Jong-Beom;Choi, Won-Joon;Kim, Jae-Won;Choi, Bong-Wook;Oh, Kwang-Joong
    • Korean Chemical Engineering Research
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    • v.47 no.5
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    • pp.639-645
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    • 2009
  • In this study, alkanolamine was used to achieve high absorption rates for $CO_2$ as suggested at several literatures. The absorption rates of aqueous AMP and MEA solutions with $CO_2$, $SO_2$, $NO_2$ were measured using a stirredcell reactor. The reaction rate constants were determined from the measured absorption rates. The performances were evaluated under various operating conditions. As a result, the reactions with $SO_2$, $NO_2$ into aqueous AMP and MEA solutions were classified as an instantaneous reaction respectively. The absorption rates increased with increase of the reaction temperature and the concentration of absorbents. The simultaneous absorption rate of $CO_2/SO_2/NO_2$ into 3, 5, 10 wt.% MEA at various pressure of $CO_2/SO_2/NO_2$, was more increased 14~20% than AMP solution. We investigated the effect of $SO_2$ and $NO_2$ on the simultaneous absorption of $CO_2/SO_2/NO_2$ from a flue gas. The performances were evaluated under various operating conditions in order to investigate the absorption characteristic.