• 제목/요약/키워드: inter-laboratory study

검색결과 168건 처리시간 0.024초

Geomechanical properties of synthesised clayey rocks in process of high-pressure compression and consolidation

  • Liu, Taogen;Li, Ling;Liu, Zaobao;Xie, Shouyi;Shao, Jianfu
    • Geomechanics and Engineering
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    • 제20권6호
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    • pp.537-546
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    • 2020
  • Oil and natural gas reserves have been recognised abundantly in clayey rich rock formations in deep costal reservoirs. It is necessary to understand the sedimentary history of those reservoir rocks to well explore these natural resources. This work designs a group of laboratory experiments to mimic the physical process of the sedimentary clay-rich rock formation. It presents characterisation results of the physical properties of the artificial clayey rocks synthesized from illite clay, quartz sand and brine water by high-pressure consolidation tests. Special focus is given on the effects of illite clay content and high-stress consolidation on the physical properties. Multi-step loaded consolidation experiments were carried out with stress up to 35 MPa on mixtures constituting of the illite clay, quartz sand and brine water with five initial illite clay contents (w=85%, 70%, 55%, 40% and 25%). Compressibility and void ratio were characterised throughout the physical compaction process of the mixtures constituting of five illite clay contents and their water permeability was measured as well. Results show that the applied stress induces a great reduction of clayey rock void ratio. Illite clay contents has a significant influence on the compressibility, void ratio and the permeability of the physically synthesized clayey rocks. There is a critical illite clay content w=70% that induces the minimum void ratio in the physically synthesised clayey rocks. The SEM study indicates, in the high-pressure synthesised clayey rocks with high illite clay contents, the illite clay minerals are located in layers and serve as the material matrix, and the quartz minerals fill in the inter-mineral pores or are embedded in the illite clay matrix. The arrangements of the minerals in microscale originate the structural anisotropy of the high-pressure synthesised clayey rock. The test findings can give an intuitive physical understanding of the deep-buried clayey rock basins in energy reservoirs.

Prediction of the human in vivo antiplatelet effect of S- and R-indobufen using population pharmacodynamic modeling and simulation based on in vitro platelet aggregation test

  • Noh, Yook-Hwan;Han, Sungpil;Choe, Sangmin;Jung, Jin-Ah;Jung, Jin-Ah;Hwang, Ae-Kyung;Lim, Hyeong-Seok
    • Translational and Clinical Pharmacology
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    • 제26권4호
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    • pp.160-165
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    • 2018
  • Indobufen ($Ibustrin^{(R)}$), a reversible inhibitor of platelet aggregation, exists in two enantiomeric forms in 1:1 ratio. Here, we characterized the anti-platelet effect of S- and R-indobufen using response surface modeling using $NONMEM^{(R)}$ and predicted the therapeutic doses exerting the maximal efficacy of each enantioselective S- and R-indobufen formulation. S- and R-indobufen were added individually or together to 24 plasma samples from drug-naïve healthy subjects, generating 892 samples containing randomly selected concentrations of the drugs of 0-128 mg/L. Collagen-induced platelet aggregation in platelet-rich plasma was determined using a Chrono-log Lumi-Aggregometer. Inhibitory sigmoid $I_{max}$ model adequately described the anti-platelet effect. The S-form was more potent, whereas the R-form showed less inter-individual variation. No significant interaction was observed between the two enantiomers. The anti-platelet effect of multiple treatments with 200 mg indobufen twice daily doses was predicted in the simulation study, and the effect of S- or R-indobufen alone at various doses was predicted to define optimal dosing regimen for each enantiomer. Simulation study predicted that 200 mg twice daily administration of S-indobufen alone will produce more treatment effect than S-and R-mixture formulation. S-indobufen produced treatment effect at lower concentration than R-indobufen. However, inter-individual variation of the pharmacodynamic response was smaller in R-indobufen. The present study suggests the optimal doses of R-and S-enantioselective indobufen formulations in terms of treatment efficacy for patients with thromboembolic problems. The proposed methodology in this study can be applied to the develop novel enantio-selective drugs more efficiently.

고위험군 HPV 검출을 위한 분석적 민감도와 특이도 성능평가 (Analytical Performance of Sensitivity and Specificity for Rapid Multiplex High Risk Human Papillomavirus Detection Kit: HPV ViroCheck)

  • 박선영;윤현석;방혜은;김연;최성경;안성우;김정호;이수지;양지영;이동섭
    • 대한임상검사과학회지
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    • 제49권4호
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    • pp.446-454
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    • 2017
  • 인간유두종 바이러스 (HPV)는 자궁경부암의 주요 원인이며, 자궁경부암의 주요 원인 바이러스는 16종의 고위험군 유전형 HPV 16, HPV 18, HPV31, HPV 33, HPV 35, HPV 39, HPV 45, HPV 51, HPV 52, HPV 53, HPV 56, HPV 58, HPV 59, HPV 66, HPV 68, HPV 69 이다. 특히, HPV 16형과 HPV 18형이 HPV 양성 암환자의 70%에서 발견된다. 따라서, 바이러스의 존재 유무를 확인하는 것은 환자의 스크리닝에 도움을 주며, 최근에 세포학적 검사와 함께 보조적인 검사법으로 사용되고 있다. 본 연구는 16종의 고위험군 바이러스와 HPV 16, HPV 18 유전형을 검출 할 수 있는 HPV ViroCheck의 발암 유전자의 분석 성능을 확립하기 위한 목적으로 수행되었다. 먼저, 16종의 고위험군 HPV의 발암유전자 E6/E7 유전형의 검출한계를 확인하기 위하여, 분석적 민감도를 수행하였다. 그리고, 관련된 미생물 및 바이러스에서의 교차반응 및 정확도를 비교하여 평가하였다. 고위험군 HPV 유전자형의 민감도는 Clone DNA를 이용 하였을 때, 최대 1카피에서 100 카피까지 검출이 가능하였고, SiHa 세포와 Hela 세포의 경우 최소 10 세포까지 검출이 가능하였다. 자궁경부 관련 미생물 및 바이러스에서 HPV 유전형에 대한 교차 반응은 나타내지 않았다. 또한, 측정법 내 변동계수 및 측정법 간 변동계수 실험 결과 변동계수가 5% 이하로 정확도가 높았다. 위의 분석 성능자료는 HPV ViroCheck의 유전자형 검사의 식품의약품 안전처의 체외진단용 의료기기 허가를 위한 자료로 사용 될 것이며, 향후, HPV 16종의 발암유전자 검출과 HPV 16, HPV 18 유전형 검출 연구에 도움이 될 것이다.

A Study on Floor Impact Sound Insulation Performance of Cross-Laminated Timber (CLT): Focused on Joint Types, Species and Thicknesses

  • Yeon-Su HA;Hyo-Jin LEE;Sang-Joon LEE;Jin-Ae SHIN;Da-Bin SONG
    • Journal of the Korean Wood Science and Technology
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    • 제51권5호
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    • pp.419-430
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    • 2023
  • In this study, the floor impact sound insulation performance of Korean domestic Cross-Laminated Timber (CLT) slabs was evaluated according to their joint types, species and thicknesses in laboratory experiments. The sound insulation performance of the CLT has not been investigated before, thus, this study was conducted to quantify basic data on floor impact sound insulation performance of CLT slabs. 5-ply and 150 mm thick CLT panels made of 2 species, Larix kaempferi and Pinus densiflora, were used for the study. The CLT panels were assembled by 3 types of inter-panel joints to form floor slabs: spline, butt and half-lap. And the 150 mm thick Larix CLT slabs were stacked to the thicknesses of 300 mm and 450 mm. The heavy-weight floor impact sound insulation performance of the 150 mm CLT slabs were evaluated to be 70 dB for the Larix slabs and 71.6 dB for the Pinus slabs, and the light-weight floor impact sound insulation performance, 78.3 dB and 79.6 dB, respectively. No significant difference in the sound insulation performance was found between the slabs of the 2 species or among the 3 types of joints. The reduction of 1 dB in the heavy-weight floor impact sound and 1.6 dB in the light-weight floor impact sound per 30 mm increase in thickness were confirmed through the experiments. This study can be viewed as the basic research for the evaluation of floor impact sound insulation performance of CLT.

Do Severity Score and Skin Temperature Asymmetry Correlate with the Subjective Pain Score in the Patients with Complex Regional Pain Syndrome?

  • Jeon, Seung Gyu;Choi, Eun Joo;Lee, Pyung Bok;Lee, Young Jae;Kim, Min Soo;Seo, Joung Hwa;Nahm, Francis Sahngun
    • The Korean Journal of Pain
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    • 제27권4호
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    • pp.339-344
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    • 2014
  • Background: The diagnostic criteria of complex regional pain syndrome (CRPS) have mainly focused on dichotomous (yes/no) categorization, which makes it difficult to compare the inter-patient's condition and to evaluate the intra-patient's subtle severity over the course of time. To overcome this limitation, many efforts have been made to create laboratory methods or scoring systems to reflect the severity of CRPS; measurement of the skin temperature asymmetry is one of the former, and the CRPS severity score (CSS) is one of the latter. However, there has been no study on the correlations among the CSS, temperature asymmetry and subjective pain score. The purpose of this study was to evaluate whether there is any correlation between the CSS, skin temperature asymmetry and subjective pain score. Methods: Patients affected with CRPS in a unilateral limb were included in this study. After making a diagnosis of CRPS according to the Budapest criteria, the CSS and skin temperature difference between the affected and unaffected limb (${\Delta}T$) was measured in each patient. Finally, we conducted a correlation analysis among the CSS, ${\Delta}T$ and visual analogue scale (VAS) score of the patients. Results: A total of 42 patients were included in this study. There was no significant correlation between the ${\Delta}T$ and VAS score (Spearman's rho = 0.066, P = 0.677). Also, the CSS and VAS score showed no significant correlation (Spearman's rho = 0.163, P = 0.303). Conclusions: The ${\Delta}T$ and CSS do not seem to reflect the degree of subjective pain in CRPS patients.

Intra-Rater Test-Retest Reliability of Ely's Test Using Smartphone in Patients With Lumbar Extension-Rotation Syndrome

  • Park, Kyue-Nam;Ha, Sung-Min;Chung, Sung-Dae;Kim, Si-Hyun;Jang, Jun-Hyeok
    • 한국전문물리치료학회지
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    • 제19권4호
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    • pp.46-54
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    • 2012
  • Ely's test is commonly used to assess rectus femoris muscle flexibility. however, a reliability limit of this test was demonstrated by a previous study. In this study, we present an alternative method using an application for a digital horizontal level in a smartphone (DHLS) to complement the reliability limit of Ely's test. The aim of this study was to examine the reliability of Ely's test using DHLS on the pelvis, compared to using visual observation (VO) of pelvic and hip motions. Nineteen patients with lumbar extension-rotation syndrome were recruited for this study. An examiner examined the rectus femoris flexibility (both pass/fail and goniometer scoring) through Ely's test using both DHLS and VO. A retest session was completed two hours later for within-day reliability and seven days later for between-day intra-rater test-retest reliability. Results showed higher Kappa values for pass/fail scoring and higher intraclass correlation coefficient values for goniometer scoring in Ely's test using DHLS, compared to using VO. Measurement error and Bland and Altman plots further demonstrated the degree of intra-rater variance during Ely's test using DHLS in a clinical setting, compared to using VO. These results demonstrated that Ely's test using DHLS showed acceptable reliability compared to using VO. Ely's test using DHLS could be widely used for measuring the rectus femoris muscle flexibility in patients with lumbar extension-rotation syndrome, although the inter-rater reliability needs to be established first.

입원환자의 초기영양평가를 위한 단순영양검색도구 개발 및 도구 간 신뢰도 검증 (Development of a simplified malnutrition screening tool for hospitalized patients and evaluation of its inter-methods reliability)

  • 윤옥희;이규휘;박윤정
    • Journal of Nutrition and Health
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    • 제47권2호
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    • pp.124-133
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    • 2014
  • 본 연구는 입원환자의 전자의무기록에서 용이하게 얻을 수 있는 지표들을 중심으로 초기영양평가를 신속하게 진행하기 위한 영양검색도구를 개발하고, 새로 개발한 영양검색도구에 대한 신뢰도을 검증하기 위한 목적으로 수행되었다. 이를 위하여 입원환자 903명을 대상으로, 의무기록 및 개별면담을 통해 자료를 수집하여 PGSGA를 기준으로 양호군과 영양불량군을 나누었다. 1) 로지스틱 회귀분석을 통해 양호군과 영양불량군으로 범주화하기 위한 최종 영양평가지표로 연령, BMI, 혈중 알부민, 혈중 콜레스테롤, 총단백질, 헤마토크리트, 체중변화, 섭취변화여부가 선정하였다. 특히 체중변화, 섭취변화여부의 경우는 예/아니오의 주관적 단답식 조사로 간단히 이루어졌다. 2) SMST의 영양평가결과 총 903명 중에서 양호군은 620명 (68.7%), 영양불량군은 283명 (31.3%)으로 나타났으며, 양호군과 영양불량군사이에 연령, 혈중 알부민, 총임파구수, BMI, 헤모글로빈, 헤마토크리트, 총단백질, 혈중 콜레스테롤, 재원기간 모두 유의적인 차이를 보였다. 3) SMST의 신뢰도를 검증하기 위해서 PGSGA와 NRS2002와의 민감도, 특이도, 카파비를 통한 일치도를 분석하였다. SM-ST는 PGSGA와 민감도 94.4%, 특이도 88.4%, 카파비 0.747로 'Substantial agreement'하며 (p < 0.001), NRS2002와 민감도 96.1%, 특이도 79.5%, 카파비 0.505로 'Moderate agreement' (p < 0.001)로 나타났다. 본 연구에서 개발한 새로운 초기영양검색 도구인 SMST의 영양평가지표는 의무기록 및 단답형의 질문으로 이루어져, 신속하고 간단한 초기영양평가가 가능하다. 특히 기존에 개인면담을 통해 시간적, 인력적 요구가 높은 영양도구들에 비해, 입원당시 기본적 신체계측과 함께 단답형으로 이뤄진 체중변화 및 식이섭취변화 여부가 기록될 경우 추가될 경우 추가조사 없는 의무기록으로 평가가 가능하다. SMST는 PGSGA, NRS2002와 높은 일치도를 보여 기존에 타당도가 높다고 알려진 두 영양검색 도구와 도구간 신뢰도가 검증되었다. 하지만 SMST는 합병증의 유무, 사망률, 재입원률, 병원비용 등 환자의 예후와 관련한 연관성 및 보편적 대상자에서의 유용성은 검증되지 않았으므로, 이에 관한 추가적인 연구가 필요하다고 사료된다.

Determination and Validation of Synthetic Antioxidants in Processed Foods Distributed in Korea

  • Park, Hyeon-Ju;Seo, Eunbin;Park, Jin-Wook;Yun, Choong-In;Kim, Young-Jun
    • 한국식품위생안전성학회지
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    • 제37권5호
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    • pp.297-305
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    • 2022
  • 산화방지제는 활성 산소에 의한 지질 산패를 방지하여 식품의 보존성을 증대하는 식품첨가물이다. 본 연구에서는 합성 산화방지제 5종 (Butylated hydroxyanisole (BHA), Butylated hydroxytoluene (BHT), Tertiary butylhydroquinone (TBHQ), Propyl gallate (PG), Disodium ethylenediaminetetraacetic acid(EDTA·2 Na))을 이용하여 HPLC-UVD 분석법에 대한 유효성 검증 및 합성 산화방지제가 표시된 실제 식품 속 함량 분석을 진행하였다. 직선성(R2)은 평균 0.9997, 검출한계(Limit of detection, LOD)와 정량한계(Limit of quantification, LOQ)는 각각 0.02-0.53과 0.07-1.61 mg/kg으로 산출하였다. 일내 및 일간 정확성과 정밀성 산출을 위하여 합성 산화방지제 4종은 콩기름과 과자, EDTA는 통조림과 마요네스를 이용하였다. 정확성과 정밀성 결과, 일내와 일간 각각 83.2±0.7-97.8±4.4와 86.2±3.3-98.3±2.1 및 0.1-6.4와 0.7-5.7 %RSD로 산출되었다. 또한 FAPAS QC material을 이용하여 실험실간 정확성 및 정밀성 검증을 진행하였으며 이는 AOAC가 제시한 가이드라인에 적합함을 확인하였다. 측정불확도 역시 CODEX에서 제시한 범위인 16% 이하인 것을 확인하였다. 따라서 본 연구를 통하여 국민 건강의 안전을 제고하기 위한 국내 산화방지제의 섭취량 및 위해성 평가를 위한 기초자료로 활용될 수 있을 것으로 사료된다.

Association of A/T Rich Microsatellites with Responses to Artificial Selection for Larval Developmental Duration in the Silkworm Bombyx mori

  • Pradeep, Appukuttan Nair Retnabhavan;Awasthi, Arvind Kumar;Urs, Raje Siddaraje
    • Molecules and Cells
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    • 제25권4호
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    • pp.467-478
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    • 2008
  • Simple sequence repeats (SSRs) and interSSR (ISSR) marker systems were used in this study to reveal genetic changes induced by artificial selection for short/long larval duration in the tropical strain Nistari of the silkworm Bombyx mori. Artificial selection separated longer larval duration (LLD) ($29.428{\pm}0.723days$) and shorter larval duration (SLD) ($22.573{\pm}0.839days$) lines from a base, inbred population of Nistari (larval span of $23.143{\pm}0.35days$). SSR polymorphism was observed between the LLD and SLD lines at one microsatellite locus, Bmsat106 ($CA_7$) and at two loci of 1074 bp and 823 bp generated with the ISSR primer UBC873. Each of these loci was present only in the LLD line. The loci segregated in the third generation of selection and were fixed in opposite directions. In the $F_2$ generation of the $LLD{\times}SLD$ lines, the alleles of Bmsat106 and $UBC873_{1074bp}$ segregated in a 1:1 ratio and the loci were present only in the LLD individuals. $UBC873_{823bp}$ was homozygous. Single factor ANOVA showed a significant association between the segregating loci and longer larval duration. Together, the two alleles contributed to an 18% increase in larval duration. The nucleotide sequences of the $UBC873_{1074bp}$ and $UBC873_{823bp}$ loci had 67% A/T content and consisted of direct, reverse, complementary and palindromic repeats. The repeats appeared to be "nested" (59%) in larger repeats or as clustered elements adjacent to other repeats. Of 203 microsatellites identified, dinucleotides (67.8%) predominated and were rich in A/T and T/A motifs. The sequences of the $UBC873_{1074bp}$ and $UBC873_{823bp}$ loci showed similarity (E = 0.0) to contigs located in Scaffold 010774 and Scaffold 000139, respectively, of the B. mori genome. BLASTN analysis of the $UBC873_{1074bp}$ sequence showed significant homology of (nt.) 45-122 with upstream region of three exons from Bombyx. The complete sequence of this locus showed ~49% nucleotide conservation with transposon 412 of Drosophila melanogaster and the Ikirara insertions of Anopheles gambiae. The A + T richness and lack of coding potential of these small loci, and their absence in the SLD line, reflect the active process of genetic change associated with the switch to short larval duration as an adaptation to the tropics.

The reliability of the nonradiologic measures of thoracic spine rotation in healthy adults

  • Hwang, Donggi;Lee, Ju Hyeong;Moon, Seongyeon;Park, Soon Woo;Woo, Juha;Kim, Cheong
    • Physical Therapy Rehabilitation Science
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    • 제6권2호
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    • pp.65-70
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    • 2017
  • Objective: The purpose of this study was to examine the intertester reliability and validity of four nonradiologic measurements of thoracic spine rotation in healthy adults. Design: Descriptive laboratory study. Methods: This study was conducted on 20 male and 20 female university students aged between 19 and 26. To measure thoracic rotation, a goniometer, a bubble inclinometer, a dual inclinometer, and a smartphone application-clinometer were used. The measurement was performed twice for each device and the same measurement was performed by two examiners. The measurements were performed in the lumbar locked position. The arm in the direction of rotation was taken back and placed onto the back of the lumbar region. With right and left trunk rotation, the head was rotated together but remained in the center line so that the axial rotation was maintained. Both examiners performed the measuring procedures and directly handled the measuring instrument. All measurement results were recorded by the recorder. Results: The range of motion (ROM) of thoracic rotation in lumbar locked position for all four devices was 47 degrees. The intra-rater reliability estimates ranged from 0.738 to 0.906 (p<0.05). The inter-rater reliability estimates ranged from 0.736 to 0.853 (p<0.05). The goniometer, bubble inclinometer, dual inclinometer, and smartphone clinometer showed high validity (p<0.05). This result indicates that all four devices may be used by the same examiner and by other examiners obtaining follow-up measurement. Conclusions: The use of the goniometer, bubble inclinometer, dual inclinometer, and smartphone clinometer for measurements in the lumbar locked posture are reliable and valid nonradiologic measures of thoracic rotational ROM in healthy adults.