• 제목/요약/키워드: sample preparations

검색결과 74건 처리시간 0.028초

What is the changing frequency of diamond burs?

  • Emir, Faruk;Ayyildiz, Simel;Sahin, Cem
    • The Journal of Advanced Prosthodontics
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    • 제10권2호
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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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    • 제32권2호
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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
    • 한국환경농학회지
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    • 제25권2호
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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).

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

  • 이혜경;이형진;이은희;김희정;이일우
    • 대한세포병리학회지
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    • 제13권2호
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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.

부산시 개원 의사와 개국 약사의 의약분업 정책목적 달성도와 손익에 대한 인식도 (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)

  • 박재성;남은우;권영철
    • 보건행정학회지
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    • 제11권4호
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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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재조합 사람성장호르몬(소마트로핀)의 KFDA 표준품(KS 98/674) 설정 연구 (Collaborative Study for the Establishment of KFDA Reference Standard for Somatropin (KS 98/674))

  • 신원;정지원;진재호;;손여원
    • 약학회지
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    • 제45권2호
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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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머랭을 이용하여 제조한 녹차증편의 품질특성 (Quality Characteristics of Green Tea Jeungpyun Made with Meringue)

  • 박재희
    • 한국식품조리과학회지
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    • 제33권1호
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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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    • 제16권1호
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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.

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

  • 박형수;이상훈;최기춘;임영철;김종근;서성;조규채
    • 한국축산시설환경학회지
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    • 제18권3호
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    • pp.257-266
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    • 2012
  • 본 연구는 조사료 품질평가에서 근적외선 분광법의 현장 이용성 확대를 위하여 시료 전처리 방법에 따른 이탈리안 라이그라스 사일리지의 사료가치 및 발효품질의 예측정확성을 평가하기 위하여 수행되었으며 검량식 개발을 위하여 이탈리안 라이그라스 사일리지를 전북지역에서 174점을 수집하였다. 시료 전처리 방법은 사일리지를 건조 후 분쇄하는 방법과 원물 (생) 시료를 건조 분쇄하지 않는 방법을 두었으며 각각의 시료는 근적외선 분광기를 이용하여 스펙트럼을 측정한 후 측정된 스펙트럼과 실험실 분석값간에 상관관계를 이용한 다변량회귀분석법을 통하여 검량식을 유도한 다음 각 성분별로 예측 정확성을 평가하였다. 시료 전처리 방법에 따른 이탈리안 라이그라스 사일리지의 수분함량의 예측 정확성은 건조 분쇄하지 않은 원물(생)시료를 그대로 측정하는 방법 (SECV 1.37%, $R^2$=0.96)이 건조 분쇄처리 방법 (SECV 4.31%, $R^2$=0.68) 보다 예측 정확성이 높게 나타났다. ADF와 NDF 함량의 예측 정확성은 건조 후 분쇄처리한 방법이 개발된 검량식을 상호검증 (SECV)한 결과 각각 0.72% ($R^2$=0.97)와 0.85% ($R^2$=0.94)로 높게 나타났으며 조회분함량 평가에 대한 검량식개발 결과는 건조분쇄하지 않은 원물(생) 시료 전처리 방법에서 가장 낮은 정확성 (SECV 1.17%, $R^2$=0.66)을 나타내었다. pH와 젖산함량은 건조 분쇄 전처리 방법에서 각각 0.48 ($R^2$=0.87)와 0.24% ($R^2$=0.87)로 우수한 결과를 나타내었다. 이상의 연구결과를 종합해보면 근적외선분광법을 이용한 시료 전처리 방법에 따른 이탈리안 라이그라스 사일리지의 사료가치 및 발효품질 평가에 대한 예측정확성은 수분함량을 제외하고는 건조 후 분쇄하는 시료 전처리 방법이 예측 정확성 측면에서는 우수한 것으로 나타났으나 시료 전처리가 필요치 않은 원물(생) 시료의 측정 방법도 매우 양호한 예측 정확성을 보임으로써 실제 근적외선분광법의 현장 활용측면에서는 매우 유용한 전처리 방법으로 판단되어진다.

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

  • 김다솜;배창환;여주홍;지원재
    • 한국미생물·생명공학회지
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    • 제44권4호
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    • pp.512-521
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    • 2016
  • 제주도에서 채집된 토양시료로부터 xylanase 활성을 나타내는 균주를 분리하여 WJ-2로 명명하였다. 균주 WJ-2의 16S rRNA 유전자 염기서열을 결정하여 이를 토대로 상동성을 검색한 결과, Streptomyces 속의 균주들과 높은 염기서열 상동성을 보였다. 16S rRNA 유전자 염기서열을 토대로하는 neighbor-joining 계통수를 제작하여 Streptomyces atrovirens와 가장 높은 계통발생적 연관성이 갖고 있는 것을 밝혔다. 또한 DNA-DNA hybridization 분석을 통하여 Streptomyces atrovirens의 신규한 아종임을 증명하였다. 균주 WJ-의 게놈내 GC 농도는 73.98 mol%이었으며, 주요 세포벽 지방산으로 anteiso-$C_{15:0}$ (36.19%)을 함유하고 있었다. 균주 WJ-2의 성장 및 xylanase 생산은 배지내에 질소원으로 soytone과 탄소원으로 xylan을 첨가하였을 때 급격히 증가되는 것을 확인하였다. 액체배양액으로부터 준비된 조효소의 xylanase 활성은 pH 7.0과 $55^{\circ}C$에서 가장 높게 나타났다. Thin layer chromatography (TLC) 분석을 통하여 균주 WJ-2의 조효소는 xylan을 분해하여 최종분해산물로서 xylobiose와 xylotriose 생산하는 효소임을 확인하였다.