• Title/Summary/Keyword: acetone

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Establishment of an Analytical Method for Novobiocin in Livestock Products Using HPLC-UVD (HPLC-UVD를 이용한 축산식품 중 Novobiocin의 시험법 확립)

  • Park, Hee-Ra;Kwon, Chan-Hyeok;Lee, Jong-Goo;Kim, Hyung-Soo;Chae, Young-Sik;Oh, Jae-Ho;Kwon, Ki-Sung
    • Korean Journal of Food Science and Technology
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    • v.44 no.3
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    • pp.263-268
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    • 2012
  • Novobiocin is a coumarin-containing antibiotic, and has a longer half-life in various animals than other veterinary medicines. A simple and rapid high-performance liquid chromatography assay for the determination of residual novobiocin levels in chicken, beef and milk has been developed and validated. The separation condition for HPLC/UVD was optimized by a MG II $C_{18}$ (4.6 mm $ID{\times}250$ mm, 5 ${\mu}m$) column with 0.1% formic acid in $H_2O$/0.1% formic acid in Acetonitrile (40/60, v/v) as the mobile phase at a flow rate of 1.0 mL/min and the detection wavelength was set at 340 nm. Residues were extracted from tissue by blending with methanol. After liquid-liquid partitioning, lipid materials were removed with n-hexane and purification as Silica (1 g, 6 mL) cartridge with 10 mL acetone/dichloromethane (10/90, v/v). Limit of quantification and linearity performed by the analytical method were 0.02 mg/kg and 0.999 ($r^2$), and the recovery range was $88.8{\pm}5.6-100.3{\pm}4.4$, $88.8{\pm}7.2-97.0{\pm}3.2$ and $88.1{\pm}4.3-92.8{\pm}3.6%$. It is expected that this analytical method with regards to novobiocin in chicken, beef and milk could be applied as an official method to administer food safety on veterinary medicines.

THE EFFECT OF PRIMING ETCHED DENTIN WITH SOLVENT ON THE MICROTENSILE BOND STRENGTH OF HYDROPHOBIC DENTIN ADHESIVE (산 부식된 상아질에 대한 용매를 이용한 프라이밍이 소수성 상아질 접착제의 미세인장접착강도에 미치는 영향)

  • Park, Eun-Sook;Bae, Ji-Hyun;Kim, Jong-Soon;Kim, Jae-Hoon;Lee, In-Bog;Kim, Chang-Keun;Son, Ho-Hyun;Cho, Byeong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.34 no.1
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    • pp.42-50
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    • 2009
  • Deterioration of long-term dentin adhesion durability is thought to occur by hydrolytic degradation within hydrophilic domains of the adhesive and hybrid layers. This study investigated the hypothesis that priming the collagen network with an organic solvent displace water without collapse and thereby obtain good bond strength with an adhesive made of hydrophobic monomers and organic solvents. Three experimental adhesives were prepared by dissolving two hydrophobic monomers, bisphenol-A-glycidylmethacrylate (Bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA), into acetone, ethanol or methanol. After an etching and rinsing procedure, the adhesives were applied onto either wet dentin surfaces (wet bonding) or dentin surfaces primed with the same solvent (solvent-primed bonding). Microtensile bond strength (MTBS) was measured at 48 hrs, 1 month and after 10,000 times of thermocycles. The bonded interfaces were evaluated using a scanning electron microscope (SEM). Regardless of bonding protocols, well-developed hybrid layers were observed at the bonded interface in most specimens. The highest mean MTBS was observed in the adhesive containing ethanol at 48 hrs. With solvent-primed bonding, increased MTBS tendencies were seen with thermo cycling in the adhesives containing ethanol or methanol. However, in the case of wet bonding, no increase in MTBS was observed with aging.

Trend and Further Research of Rice Quality Evaluation (쌀의 품질평가 현황과 금후 연구방향)

  • Son, Jong-Rok;Kim, Jae-Hyun;Lee, Jung-Il;Youn, Young-Hwan;Kim, Jae-Kyu;Hwang, Hung-Goo;Moon, Hun-Pal
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47
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    • pp.33-54
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    • 2002
  • Rice quality is much dependent on the pre-and post harvest management. There are many parameters which influence rice or cooked rice qualitys such as cultivars, climate, soil, harvest time, drying, milling, storage, safety, nutritive value, taste, marketing, eating, cooking conditions, and each nations' food culture. Thus, vice evaluation might not be carried out by only some parameters. Physicochemical evaluation of rice deals with amy-lose content, gelatinizing property, and its relation with taste. The amylose content of good vice in Korea is defined at 17 to 20%. Other parameters considered are as follows; ratio of protein body-1 per total protein amount in relation to taste, and oleic/linoleic acid ratio in relation to storage safety. The rice higher Mg/K ratio is considered as high quality. The optimum value is over 1.5 to 1.6. It was reported that the contents of oligosaccharide, glutamic acid or its derivatives and its proportionalities have high corelation with the taste of rice. Major aromatic compounds in rice have been known as hexanal, acetone, pentanal, butanal, octanal, and heptanal. Recently, it was found that muco-polysaccharides are solubilized during cooking. Cooked rice surface is coated by the muco-polysaccharide. The muco-polysaccharide aye contributing to the consistency and collecting free amino acids and vitamins. Thus, these parameters might be regarded as important items for quality and taste evaluation of rice. Ingredients of rice related with the taste are not confined to the total rice grain. In the internal kernel, starch is main component but nitrogen and mineral compounds are localized at the external kernel. The ingredients related with taste are contained in 91 to 86% part of the outside kernel. For safety that is considered an important evaluation item of rice quality, each residual tolerance limit for agricultural chemicals must be adopted in our country. During drying, rice quality can decline by the reasons of high drying temperature, overdrying, and rapid drying. These result in cracked grain or decolored kernel. Intrinsic enzymes react partially during the rice storage. Because of these enzymes, starch, lipid, or protein can be slowly degraded, resulting in the decline of appearance quality, occurrence of aging aroma, and increased hardness of cooked rice. Milling conditions concerned with quality are paddy quality, milling method, and milling machines. To produce high quality rice, head rice must contain over three fourths of the normal rice kernels, and broken, damaged, colored, and immature kernels must be eliminated. In addition to milling equipment, color sorter and length grader must be installed for the production of such rice. Head rice was examined using the 45 brand rices circulating in Korea, Japan, America, Australia, and China. It was found that the head rice rate of brand rice in our country was approximately 57.4% and 80-86% in foreign countries. In order to develop a rice quality evaluation system, evaluation of technics must be further developed : more detailed measure of qualities, search for taste-related components, creation and grade classification of quality evaluation factors at each management stage of treatment after harvest, evaluation of rice as food material as well as for rice cooking, and method development for simple evaluation and establishment of equation for palatability. On policy concerns, the following must be conducted : development of price discrimination in conformity to rice cultivar and grade under the basis of quality evaluation method, fixation of head rice branding, and introduction of low temperature circulation.

Development and validation of an analytical method for nematicide imicyafos determination in agricultural products by HPLC-UVD (HPLC-UVD를 이용한 살선충제 imicyafos의 시험법 개발 및 검증)

  • Do, Jung-Ah;Park, Hyejin;Kwon, Ji-Eun;Choi, Won-Jo;Lee, Hyun-Sook;Chang, Moon-Ik;Hong, Jin-Hwan;Oh, Jae-Ho
    • Analytical Science and Technology
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    • v.27 no.5
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    • pp.234-242
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    • 2014
  • Imicyafos which is a nematicide for controlling root-knot nematodes has been registered in the Republic of Korea in 2012, and the maximum residue limits of imicyafos are set to watermelon and korean melon as each 0.05 mg/kg. Extremely reliable and sensitive analytical method is required for ensuring food safety on imicyafos residues in agricultural commodities. Imicyafos residues in samples were extracted with acetone, partitioned with hexane and dichloromethane, and then purified with florisil. The purified samples were analyzed by HPLC-UVD and confirmed with LC-MS. Linear range was between 0.1~5 mg/kg with the correlation coefficient ($r^2$) 0.99997. Average recoveries of imicyafos ranged from 77.0 to 115.4% at the spiked levels of 0.02 and 0.05 mg/kg with the relative standard deviations of 2.2~9.6%. Limit of detection and quantification were 0.005 and 0.02 mg/kg, respectively. An inter-laboratory study was conducted to validate the determination method in depth, and the results were satisfactory. All of the validation results revealed that the developed analytical method in this study is relevant for imicyafos determination in agricultural commodities and will be used as an official analytical method.

Method Development for the Profiling Analysis of Endogenous Metabolites by Accurate-Mass Quadrupole Time-of-Flight(Q-TOF) LC/MS (LC/TOFMS를 이용한 생체시료의 내인성 대사체 분석법 개발)

  • Lee, In-Sun;Kim, Jin-Ho;Cho, Soo-Yeul;Shim, Sun-Bo;Park, Hye-Jin;Lee, Jin-Hee;Lee, Ji-Hyun;Hwang, In-Sun;Kim, Sung-Il;Lee, Jung-Hee;Cho, Su-Yeon;Choi, Don-Woong;Cho, Yang-Ha
    • Journal of Food Hygiene and Safety
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    • v.25 no.4
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    • pp.388-394
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    • 2010
  • Metabolomics aims at the comprehensive, qualitative and quantitative analysis of wide arrays of endogenous metabolites in biological samples. It has shown particular promise in the area of toxicology and drug development, functional genomics, system biology and clinical diagnosis. In this study, analytical technique of MS instrument with high resolution mass measurement, such as time-of-flight (TOF) was validated for the purpose of investigation of amino acids, sugars and fatty acids. Rat urine and serum samples were extracted by selected each solvent (50% acetonitrile, 100% acetonitrile, acetone, methanol, water, ether) extraction method. We determined the optimized liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) system and selected appropriated columns, mobile phases, fragment energy and collision energy, which could search 17 metabolites. The spectral data collected from LC/TOFMS were tested by ANOVA. Obtained with the use of LC/TOFMS technique, our results indicated that (1) MS and MS/MS parameters were optimized and most abundant product ion of each metabolite were selected to be monitorized; (2) with design of experiment analysis, methanol yielded the optimal extraction efficiency. Therefore, the results of this study are expected to be useful in the endogenous metabolite fields according to validated SOP for endogenous amino acids, sugars and fatty acids.

Clinical Observation for the 161 Cases of CVA (뇌졸중환자(腦卒中患者) 161례(例)에 대(對)한 임상적(臨床的) 고찰(考察))

  • Kang, Myeong-Seog;Jun, Chan-Yong;Park, Chong-Hyeong
    • The Journal of Korean Medicine
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    • v.16 no.2 s.30
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    • pp.17-35
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    • 1995
  • Clinical observation was made on 161 cases of CVA that were confirmed through brain CT, MRI scan and clinical observation. They were hospitalized in the oriental medical hospital of Kyung-Won University from January to December in 1994. 1. The CVA cases were classified into the following kinds: cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage(SAH), transient ischemic attack, hypertensive encephalopathy, and the greatest in number among them were the cases of cerebral infarction. 2. The frequency of strokes was much the same between male and female cases and most cases were over 50 of age. 3. In the case of cerebral infarction the place of the most frequent occurrences was in the MCA territory, and as for cerebral hemorrhage, in the basal ganglia area. 4. The most ordinary preceding disease was hypertension. The next was diabetes mellitus. 5. Generally it is thought that CVA occurs frequently in winter. But on the contrary this study of observation confirmed that it occurs mostly in summer. 6. The predisposing factors of cerebral infarction were usually initiated during the time of resting and sleeping and those of cerebral hemorrhage chiefly during the time of exercising. 7. As concerns the course of hospitalization, most patients passed through western medical hospitals or oriental medical hospitals. 8. For the patients the condition of whose consciousness was bad at the time of admission, the prognosis in most cases was bad. 9. The common symptoms were motor disability and verbal disturbance. 10. With regard to cerebral infarction, the average time to start physical theraphy was 11.4 days and with cerebral hemorrhage 22.7 days after stroke. 11. The duration of hospitalization was in most cases more than one month. 12. The main complication was urinary tract infection. The next was pneumonia. 13. At the time of admission to hospital, the blood pressure in most cases was high, but it well controlled at the time of discharge. 14. Most cases were given simultaneous treatment in both ways of western and oriental medicine.

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THE EFFECT OF OXYGEN INHIBITION ON INTERFACIAL BONDING BETWEEN COMPOSITE RESIN LAYERS (복합레진 적층계면에서 oxygen inhibition의 영향에 관한 연구)

  • Choi, Su-Mi;Park, Jae-Hong;Choi, Sung-Chul;Kim, Kwang-Chul;Choi, Young-Chul
    • Journal of the korean academy of Pediatric Dentistry
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    • v.37 no.3
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    • pp.298-307
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    • 2010
  • The purpose of this study was to assess the effect on oxygen inhibition layer(OIL) for the interfacial bonding between resin composite layers, including shear bond strength, fracture modes and degree of conversion. The first layer of specimen was filled with Z-250(shade A3) and was cured for 40s. The second layer of specimen was filled with same composite(shade A1) and was cured for 40s. The first layer of specimens for each group were prepared by methods as followings. Control(curing in atmospheric air), Group1(curing against Mylar strip), Group2(scrubbed with a acetone-soaked cotton), Group3(using Tescera light cup), Group4(using Tescera heat cup), Group5(stored in disti1led water for 30days at $37^{\circ}C$), Group6 (using bonding agent). The results were as follows: 1. There was no statistically significant different shear bond strength between control and group 1(p>0.05). 2. Group 2 showed significantly lower shear bond strength than control and group 1(p<0.05). 3. The observation of the fracture surface leads to the evidence that a major difference occurs in the case of control, group1 and group 3 samples which break mainly cohesively while the other groups break in majority adhesively. 4. The results of FTIR showed that the degree of conversion was the highest in group 2 and the lowest in control group(p<0.05). It can be concluded that an OIL is not necessary for bonding with composite resin. But if a reduced critical amount of the unreacted monomer is present, it was detrimental to bonding additional layers of composite. Further study, such as the quantitative analysis of the unreacted monomer are required.

Comparative study of acupuncture and invasive laser acupuncture therapy at $SI_3$.$BL_{40}$ on the tibial, sural nerve injury and L5 spinal nerve ligation model in rats (백서(白鼠)의 신경병리성(神經病理性) 동통(疼痛)에 대한 후계(後谿).위중(委中) 혈위(穴位) 호침료법(毫鍼療法)과 레이저 침습조사(侵襲照射) 침료법(鍼療法)과의 비교(比較) 연구(硏究))

  • Wei, Tung-Sheun;Youn, Dae-Hwan;Youn, Yeo-Chung;Na, Chang-Su
    • Korean Journal of Acupuncture
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    • v.22 no.2
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    • pp.9-24
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    • 2005
  • Objective: We have studied the effects of acupuncture and low level He-Ne laser therapy(LLLT) at $SI_3$, $BL_{40}$ on the tibial, sural nerve injury due to sports-damage or traffic accident and L5 spinal nerve ligature model like general herniation of nucleus pulposus(HNP) in a rat of neuopathic pain. Methods: A model of neuropathic pain was made by injuring tibial nerve and sural nerve while common peroneal nerve was maintained. Also, it was made by isolating left 5th lumbar spinal nerve. Three weeks after the neuropathic surgery, acupuncture and LLLT was injected at $SI_3$,$BL_{40}$ one time a day for one week. LLLT was divided three groups, that is LLLT-1(5mW), LLLT-2(10mW) and LLLT-3(30mW). After that, we examined the withdrawal response of neuropathic rats' legs by Von frey filament and acetone stimulation. And also we examined c-Fos, Nocieptin and KOR-3 in the midbrain central gray of neuropathic rats. Results: As we have observed the effect of mechanical allodynia, LLLT-3 group were diminished on 4 day, 5 day, 6 day and 7 day in the resection model compared with control model, LLLT-1 group were diminished on 5 day, LLLT-2 group were diminished on 3 day and 6 day, LLLT-3 group were diminished on 3 day, 4 day, 5 day, 6 day and 7 day in connected model compared with control group. As we have observed the effect of cold allodynia, LLLT-3 group were diminished on 7 day in the resection model compared with control model, LLLT-1 group were diminished on 6 day, 7 day, LLLT-3 group were diminished on 7 day in connected model compared with control group. As we have observed the effect of activity of c-Fos in the central gray part, LLLT-3 were diminished in resection model compared with control group, LLLT-1 group were diminished in connected model compared with control group. As we have observed the effect of activity of Nociceptin in the central gray part, resection model were not increased compared with control group, LLLT-1 group and LLLT-3 group were increased in connected model compared with control model. As we have observed the effect of activity of KOR-3 in the central gray part, resection model were not increased compared with control group, LLLT-3 group were increased in connected model compared with control model. Conclusions: We have noticed that LLLT-1 and LLLT-3 group have more controllable effect than acupuncture group. This study can be used in clinical therapy for neuropathic pain. But it is not reliability that Nociceptin and KOR-3 have effectively to control pain. Therefore We have to follow up about that.

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Synthesis of Methanol from Carbon Dioxide (I). Study on Cu / ZnO Catalyst System (이산화탄소에 의한 메탄올 합성 (제 1 보). Cu / ZnO 촉매계 연구)

  • Sung Yun Cho;Ki Won Jun;Dae Chul Park;Kyu Wan Lee
    • Journal of the Korean Chemical Society
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    • v.33 no.5
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    • pp.558-567
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    • 1989
  • The synthesis of methanol from carbon dioxide and hydrogen was studied for various compositions of Cu/ZnO catalyst system. Effect of the composition ratio of CuO and ZnO on the catalytic activity in the above reaction and the relationship between the activity and the characteristics of the catalysts were explained from the result of surface area measurements, SEM, XRD, and XPS. The major products of the reaction were methanol and carbon monoxide. The selectivity to methanol increased with increase of the copper oxide content in the catalyst up to CuO: ZnO = 30:70 weight ratio, and decreased rapidly when the content is above 70%. SEM and BET measurements, indicate that this point corresponds to the increasing point of the catalyst crystallite size and the decreasing point of the surface area. As to the Cu/Cu + Zn atomic ratio, the surface concentration of copper measured by XPS decreased remarkably when the copper oxide content in catalyst was higher than 50%. All the unreduced catalysts had almost same binding energy of Cu(2P3) level, but the binding energy for $Cu(2P^3)$ level of reduced catalysts was lowered than that of calcined catalysts. The surface copper species which was in the maximum amount when the CuO:ZnO composition in the catalyst was 30:70, existed as zero valent copper. This result agreed with the experimental result that the highest rate of methanol formation was observed when the CuO content in the catalyst was 30%. It was postulated that these reduced catalysts performed with a relatively strong basicity because the formation rate of acetone was higher than that of propylene in isopropanol decomposition as measured in a pulse type reactor.

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Effects of Bisphenol A on the Hatching of fertilized Eggs and Spawning of Adult Fish in Songsari, Oryzias latipes (Bisphenol A가 송사리, Oryzias latipes의 수정란 부화와 어미의 산란에 미치는 영향)

  • NA Oh Soo;OH Seong Rip;LEE Young Don;BAEK Hea Ja;KIM Hyung Bae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.33 no.5
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    • pp.378-382
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    • 2000
  • The effects of bisphenol A (BPA), known as one of the endocrine disrupting chemicals (EDCs), on the hatching of fertilized eggs (FE) and the spawning of adult fish in songsari, Oryzias latipes were investigated. In condition of the experimental groups, incubated water temperature was $25.0{\pm}0.5^{\circ}C$ and photoperiod was 16 h (light) : 8 h (dark). fE were exposed to aqueous solutions of BPA at nominal concentration of 50, 100 and $200 {\mu}g/l$. The time required in hatching of FE was long in the BPA $50 and 100 {\mu}g/l$ treatment groups when compared to the controls, and in the BPA $200 {\mu}g/l$ treatment group, FE failed to hatch. And also hatching rate was decreased in the BPA treatment groups in comparison to the controls, Adult fishes were reared to oral administration via a diet of 50, 100 and $200 {\mu}g/g$ body weight BPA concentration for 3 weeks, Number of total eggs spawned in the adult fish were fewer in the BPA 100 and 200 treatment groups than in the controls and BPA 50 treatment group. Frequency of abnormal eggs in the total eggs spawned was 11.8 and $16.2{\%}$ in the control and acetone carrier control lower than 36.8, 46,8 and $74.1{\%}$ in the BPA 50, 100 and 200 treatment groups, respectively. And hatching rate of FE decreased in the BPA treatment groups in comparison to the controls. In these results, inhibition of the hatching of FE and the quantity and quality of spawned eggs in adult fish were observed from BPA treatment groups when compared to the controls.

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