• Title/Summary/Keyword: sample preparations

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What is the changing frequency of diamond burs?

  • Emir, Faruk;Ayyildiz, Simel;Sahin, Cem
    • The Journal of Advanced Prosthodontics
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    • v.10 no.2
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    • pp.93-100
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    • 2018
  • PURPOSE. The purpose of this study was to determine the changing frequency of a diamond bur after multiple usages on 3 different surfaces. MATERIALS AND METHODS. Human premolar teeth (N = 26), disc shaped direct metal laser sintered CoCr (N = 3) and zirconia specimens (N = 3) were used in this study. Groups named basically as Group T for teeth, Group M for CoCr, and Group Z for zirconia. Round tapered black-band diamond bur was used. The specimens were randomly divided into three groups and placed with a special assembly onto the surveyor. 1, 5, and 10 preparation protocols were performed to the first, second, and third sub-groups, respectively. The subgroups were named according to preparation numbers (1, 5, 10). The mentioned bur of each group was then used at another horizontal preparation on a new tooth sample. The same procedure was used for CoCr and zirconia disc specimens. All of the bur surfaces were evaluated using roughness analysis. Then, horizontal tooth preparation surfaces were examined under both stereomicroscope and SEM. The depth maps of tooth surfaces were also obtained from digital stereomicroscopic images. The results were statistically analyzed using One-Way ANOVA, and the Tukey HSD post-hoc tests (${\alpha}=.05$). RESULTS. All of the groups were significantly different from the control group (P<.001). There was no significant difference between groups Z5 and Z10 (P=.928). Significant differences were found among groups T5, M5, and Z5 (P<.001). CONCLUSION. Diamond burs wear after multiple use and they should be changed after 5 teeth preparations at most. A diamond bur should not be used for teeth preparation after try-in procedures of metal or zirconia substructures.

A Metal Enhanced Flow-Injection Chemiluminescence Method for the Rapid Determination of Norfloxacin in Pharmaceutical Formulations and Serum Sample

  • Kamruzzaman, Mohammad;Ferdous, Taslima;Alam, Al-Mahmnur;Lee, Sang-Hak;Kim, So-Yeun;Kim, Young-Ho;Kim, Sung-Hong
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.639-644
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    • 2011
  • A simple and highly sensitive chemiluminescence method to determine norfloxacin (NFLX) has been proposed by measuring the chemiluminescence (CL) intensities using a flow injection (FI) system. The CL intensity of the luminol-$H_2O_2$ system is strongly enhanced by the addition of Cu (II) in alkaline condition. The CL intensity is substantially increased after the injection of NFLX into the luminol-$H_2O_2$-Cu (II) system. The enhancement effect is attributed to a catalytic effect of Cu (II) due to the interaction with NFLX which forms a complex with the catalyst. Under the optimal conditions, the sensitizing effect of the CL intensity is proportional to the concentration of NFLX in the range of $1.5{\times}10^{-9}-5.9{\times}10^{-7}molL^{-1}$ (r = 0.9994) with a detection limit ($3{\sigma}$) of $2.98{\times}10^{-10}molL^{-1}$. The proposed method had good reproducibility with the relative standard deviation (RSD, n = 5) of 1.6% for $1{\times}10^{-7}molL^{-1}$ of NFLX. The possible reaction mechanism of the CL reaction is also discussed. This method has been successfully applied for the determination of trace amount of NFLX in pharmaceutical preparations and serum samples.

Residues of Diazinon in Growing Chinese cabbage: A study Under Greenhouse Conditions

  • Khay, Sathya;El-Aty, A.M. Abd;Lim, Kye-Taek;Shim, Jae-Han
    • Korean Journal of Environmental Agriculture
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    • v.25 no.2
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    • pp.174-179
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    • 2006
  • Chinese cabbage, Braccica campestris has long been consumed as a staple food for Koreans in various forms of fresh, salted, and fermented Kimchi. Cultivation of the crop under greenhouse has become a general practices to fulfill its off-seasonal consumer's demand. However, agricultural practices of the crop have always accompanied with heavy applications of pesticides caused by severe outbreaks of diseases and pose under warm and humid circumferences. Since dissipation patterns of pesticide residues in/on the crop under greenhouse conditions ate quite different from those in the open-air, changes of diazinon, O,O-diethyl O-2-isopropyl-6-methylpyrimidin-4-yl phosphornthioate, in/on the Chinese cabbage applied by foliar spraying under greenhouse were studied. Diazinon 34% EC was applied with dilution of recommended and double dose to the crop. The shoots of crop were harvested immediately after this application and at regular intervals over a 10-day. After sample preparations, the diazinon residue was analyzed using gas chromatography equipped with electron capture detector (GC/ECD). Initially deposited amount of the chemical in/on the crop right after applications with recommended and double doses were 8.3 and 15.2 mg/kg, respectively. The residue levels after 10 days of application were 0.03 and 0.09 mg/kg with 1.3 and 1.5 days of half-life in/on the crop, respectively. In consequent 10 days of pre-harvest interval (PHI) for diazinon EC formulation in/on Chinese cabbage under greenhouse condition was fulfill maximum residue level set by Korea Food and Drug Administration (KFDA, 0.1 mg/kg).

Usefulness of Cytologic Study of Intraoperative Suction Fluid in Brain Tumors (수술시 뇌종양 흡인액의 세포학적 검사의 유용성)

  • Lee, Hye-Kyung;Lee, Hyung-Jin;Lee, Eun-Hee;Kim, Hee-Jung;Lee, Il-Woo
    • The Korean Journal of Cytopathology
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    • v.13 no.2
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    • pp.66-69
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    • 2002
  • In diagnosing a brain tumor, it is essential to obtain samples from many areas of the tumor. Although there are reports about the suitability of material obtained by cavitron ultrasonic surgical aspirator(CUSA), there is a paucity of reports regarding conventional intraoperative suction. This study was performed to evaluate the usefulness of the suction fluid and the effect of different hemolytic fixatives. Intraoperative suction fluid was obtained from 2 pituitary adenomas and 2 choroid plexus carcinomas. In two cases of mixed astro-oligodendroglioma, one of glioblastoma multiforme and 3 of meningioma, the fluid was collected by CUSA. Each sample was divided into four bottles for the different fixatives such as 0.1N HCI, 10% acetic acid, 95% alcohol, and no additive. All cases were evaluated by the both cytologic smear and cell block preparations, and were reviewed with concomitant histologic diagnosis. The result showed a good correlation between the cytologic study and the histologic diagnosis and 95% alcohol was found to be superior to other fixatives in ceil preservation.

Physicians and Pharmacists' Perceptions about the Goal Achievement of the Separation Policy of Drug Prescribing and Dispensing, and Benefit and Loss Caused by the Policy in Busan (부산시 개원 의사와 개국 약사의 의약분업 정책목적 달성도와 손익에 대한 인식도)

  • 박재성;남은우;권영철
    • Health Policy and Management
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    • v.11 no.4
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    • pp.70-87
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    • 2001
  • The purpose of this study was to identify health care providers' perceptions about the goal achievement and benefit/loss caused by the separation policy of drug prescribing and dispensing after the policy implemented on July 1, 2001. Uslng stratified sampling method based on the administration area, Ku, 315 physicians and pharmacists were sampled from the rosters of physician and pharmacist association in the city of Busan on 2001. There were 122 and 115 responses from physician and pharmacist sample, respectively. 78.3% of physicians and 50.4% of pharmacists evaluated that the goal of the policy was not achieved. Moreover, 75.3% of physicians and 40.7% of pharmacists did not support the policy. Most physicians and pharmacists considered preventing the citizens with drug abuse and misuses as the most important benefit derived from the policy. However, physicians and pharmacists concerned over raising health care cost that could be patients' burden. The most important physicians' benefit derived from the policy was free choice of all possible medicine that might result in effectiveness of medication. In physicians' the most important loss, most physicians worried about that breaking traditional patient and physician relationship might cause physicians' authority in treating diseases to be damaged. Pharmacists considered the most important policy benefit as hiked social status resulted from enforcement of profession due to the policy whereas they considered the most significant loss as expected financial problems of small pharmacies compared to that of large pharmacies or pharmacies adjacent to hospitals. In the current problems of the policy, physician and pharmacists blamed the government for inadequate preparations of the policy implementation. Physicians and pharmacists also considered citizens' mature attitudes toward the policy as a crucial success factor.

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Collaborative Study for the Establishment of KFDA Reference Standard for Somatropin (KS 98/674) (재조합 사람성장호르몬(소마트로핀)의 KFDA 표준품(KS 98/674) 설정 연구)

  • Shin, Won;Joung, Jee-Won;Jin, Jae-Ho;Bristow, Adrian F.;Sohn, Yeo-Won
    • YAKHAK HOEJI
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    • v.45 no.2
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    • pp.227-236
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    • 2001
  • The complexity and variability of both the biologicals and the bioassays used to test them led to the use of the reference standard- a sample of the product of defined purity and potency, against which all preparations of that product must be calibrated. In order to prepare and establish KFDA reference standard for recombinant human growth hormone (somatropin), somatropin substance was filled in ampoules in National Institute for Biological Standards and Control (NIBSC). The candidate KFDA reference standard for somatropin (designated as 98/674) was evaluated to determine the suitability of serving as a KFDA reference standard for somatropin by the collaborative study, in which 10 laboratories participated. Physicochemical analysis and in vivo bioassay were performed by direct comparison with the international somatropin standard 88/624. 98/674 was identified as somatropin by SDS-PAGE, IEF, peptide mapping, and HPLC. Determination of somatropin content by SE-HPLC yielded a mean estimate of 2.01 mg somatropin per ampoule. Data from the study also yielded mean values of 0.39 $\pm$ 0.26% for high molecular weight impurities by SE-HPLC and mean values of 2.13 $\pm$ 1.29% for somatropin related proteins by RP-HPLC. Estimates of relative potency by weight gain bioassay in the hypophysectomised rats showed that relative potency of KS 98/674 was 1.07 aganist IS 88/624. Based on the results of the collaborative study, the candidate reference standard for somatropin is suitable to serve as a KFDA reference standard for somatropin.

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Quality Characteristics of Green Tea Jeungpyun Made with Meringue (머랭을 이용하여 제조한 녹차증편의 품질특성)

  • Park, Jae-Hee
    • Korean journal of food and cookery science
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    • v.33 no.1
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    • pp.37-44
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    • 2017
  • Purpose: The purpose of this study was to simplify the traditional manufacturing method of Jeungpyun by developing a new process for Jeungpyun preparation using meringue and to also investigate the quality characteristics of Jeungpyun made with green tea powder. Methods: The Jeungpyun was manufactured as 4 sample preparations (Jeungpyun: J; Jeungpyun+0.5% green tea: J+0.5% GT; Jeungpyun+1% green tea: J+1% GT; and Jeungpyun+1.5% green tea: J+1.5% GT) through mixing rice flour, meringue, green tea powder (0-1.5%), dry yeast, water, and milk, steaming for 4 min at $180^{\circ}C$ and 3 min at $220^{\circ}C$, and then standing for 1 hr at room temperature. The quality characteristics of Jeungpyun were evaluated based on physicochemical properties, total mold, texture analysis, and sensory evaluation. Results: The pH of Jeungpyun batter was significantly lower in J+1.0% GT and J+1.5% GT than J. The specific gravity, weight, volume, and specific volume of J+0.5% GT and J+1% GT was not significantly different, as compared to J. In color, L value decreased and a and b value increased based on the increase of green tea powder. The antifungal activity was the highest in J+1.5% GT, followed by J+1.0% GT, J+0.5% GT, and J, in order. Samples with added green tea powder showed decreased hardness, as compared with J; its effect was significant in J+1.0% GT and J+1.5% GT after storage for 1 day. In sensory evaluation, the color of Jeungpyun was darkened by the addition of green tea powder. The egg smell and hardness significantly decreased by addition of green tea powder. Based on quantitative description analyses, overall acceptability was the highest in J+1% GT. Conclusion: Therefore, 1% green tea powder was the optimal amount for preparing Jeungpyun with meringue. For simplification of the traditional manufacturing method, Jeungpyun could be produced with meringue and green tea powder, which has potent physiological activities.

Effects of a Soaking-Fermentation-Drying Process on the Isoflavone and ${\gamma}$-Aminobutyric acid Contents of Soybean

  • Kim, Tae-Jin;Sung, Chang-Hyun;Kim, Young-Jin;Jung, Byung-Moon;Kim, Eung-Ryool;Choi, Won-Sun;Jung, Hoo-Kil;Chun, Ho-Nam;Kim, Woo-Jung;Yoo, Sang-Ho
    • Food Science and Biotechnology
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    • v.16 no.1
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    • pp.83-89
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    • 2007
  • In our study, lactic acid bacteria (LAB)-fermented whey solutions were applied in the soybean soaking process to minimize bacterial contamination and to enrich the biologically functional components of isoflavone and $\gamma$-aminobutyric acid (GABA). Among the 11 LAB tested, Bifidobacteria infantis and a mixed culture (Lactobacillus acidophilus, Bifidobacteria lactis, and Streptococcus thermophilus; ABT-3) displaying the greatest $\beta$-glucosidase activity were selected to produce improved biologically functional soybean preparations. In the soybean soaking processing (without water spraying), the LAB-cultured 10% whey solution was used to soak and to ferment the soybeans and the fermented soybeans were finally dried by heat-blowing at $55^{\circ}C$. The processing conditions used in this study demonstrated that the final soybean product had a reduced contamination by aerobic and coliform bacteria, compared to raw soybeans, likely due to the decrease in pH during LAB fermentation. The aglycone content of the isoflavone increased up to 44.6 mg per 100 g of dried soybean by the processing method, or approximately 8-9 times as much as their initial content. The GABA contents in the processed samples increased as the processing time of soaking-fermentation proceeded as well. The soybean sample that fermented by ABT-3 culture for 24 hr showed the greatest increase in GABA content (23.95 to 97.79 mg/100 g), probably as a result of the activity of glutamate decarboxylases (GAD) released from the soybean or produced by LAB during the soaking process.

Effect of Sample Preparation on Predicting Chemical Composition and Fermentation Parameters in Italian ryegrass Silages by Near Infrared Spectroscopy (시료 전처리 방법이 근적외선분광법을 이용한 이탈리안 라이그라스 사일리지의 화학적 조성분 및 발효품질 평가에 미치는 영향)

  • Park, Hyung Soo;Lee, Sang Hoon;Choi, Ki Choon;Lim, Young Chul;Kim, Jong Gun;Seo, Sung;Jo, Kyu Chea
    • Journal of Animal Environmental Science
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    • v.18 no.3
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    • pp.257-266
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    • 2012
  • Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal and dired animal forages. Analysis of forage quality by NIRS usually involves dry grinding samples. Costs might be reduced if samples could be analyzed without drying or grinding. The objective of this study was to investigate effect of sample preparations on prediction ability of chemical composition and fermentation parameter for Italian ryegrass silages by NIRS. A population of 147 Italian ryegrass silages representing a wide range in chemical parameters were used in this investigation. Samples were scanned at 1nm intervals over the wavelength range 680-2500 nm and the optical data recorded as log 1/Reflectance (log 1/R) and scanned in oven-dried grinding and fresh ungrinding condition. The spectral data were regressed against a range of chemical parameters using partial least squares (PLS) multivariate analysis in conjunction with four spectral math treatments to reduced the effect of extraneous noise. The optimum calibrations were selected on the basis of minimizing the standard error of cross validation (SECV) and maximizing the correlation coefficient of cross validation (${R^2}_{CV}$). The results of this study show that NIRS predicted the chemical parameters with high degree of accuracy in oven-dried grinding treatment except for moisture contents. Prediction accuracy of the moisture contents was better for fresh ungrinding treatment (SECV 1.37%, $R^2$ 0.96) than for oven-dried grinding treatments (SECV 4.31%, $R^2$ 0.68). Although the statistical indexes for accuracy of the prediction were the lower in fresh ungrinding treatment, fresh treatment may be acceptable when processing is costly or when some changes in component due to the processing are expected. Results of this experiment showed the possibility of NIRS method to predict the chemical composition and fermentation parameter of Italian ryegrass silages as routine analysis method in feeding value evaluation and for farmer advice.

Identification and Biochemical Characterization of a New Xylan-degrading Streptomyces atrovirens Subspecies WJ-2 Isolated from Soil of Jeju Island in Korea (제주도 토양으로부터 자일란 분해 Streptomyces atrovirens subspecies WJ-2 동정 및 효소의 생화학적 특성 규명)

  • Kim, Da Som;Bae, Chang Hwan;Yeo, Joo Hong;Chi, Won-Jae
    • Microbiology and Biotechnology Letters
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    • v.44 no.4
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    • pp.512-521
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    • 2016
  • A bacterial strain was isolated from a soil sample collected on Jeju Island, Korea. The strain, designated WJ-2, exhibited a high xylanase activity, whereas cellulase activity was not detected. The 16S rRNA gene sequence of WJ-2 was highly similar to type strains of the genus Streptomyces. A neighbor-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain WJ-2 is phylogenetically related to Streptomyces atrovirens. Furthermore, DNA-DNA hybridization analysis confirmed that strain WJ-2 is a novel subspecies of Streptomyces atrovirens. The genomic DNA G+C content was 73.98 mol% and the major fatty acid present was anteiso-C15:0 (36.19%). The growth and xylanase production of strain WJ-2 were significantly enhanced by using soytone and xylan as nitrogen and carbon sources, respectively. Crude enzyme preparations from the culture broth of strain WJ-2 exhibited maximal total xylanase activities at pH 7.0 and $55^{\circ}C$. Thin-layer chromatography analysis revealed that the crude enzyme degrades beechwood xylan to yield xylobiose and xylotriose as the principal hydrolyzed end products.