• Title/Summary/Keyword: 한계조건

Search Result 2,140, Processing Time 0.021 seconds

Sensitive determination of paroxetine in canine plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS) (LC-MS/MS를 이용한 비글견 혈장 중 파록세틴의 고감도 분석)

  • Chang, Kyu Young;Kang, Seung Woo;Han, Sang Beom;Youm, Jeong-Rok;Lee, Kyung Ryul;Lee, Hee Joo
    • Analytical Science and Technology
    • /
    • v.20 no.2
    • /
    • pp.138-146
    • /
    • 2007
  • A simple and sensitive method for the determination of paroxetine in canine plasma was developed and validated by liquid-liquid extraction and liquid chromatography-tandem mass spectrometry (LC-/MS/MS). Fluoxetine was used as an internal standard. Paroxetine and internal standard in plasma samples were extracted using TBME (tert-butyl methyl ether). A centrifuged upper layer was then evaporated and reconstituted with mobile phase of 50% acetonitrile adjusted to pH 3 by formic acid. The reconstituted samples were injected into a Capcell Pak UG120 ($2.0{\times}150mm$, $5{\mu}m$) column. Using MS/MS with SRM (selective reaction monitoring) mode, the transitions (precursor to product) monitored were m/z $330{\rightarrow}192$ for paroxetine, and m/z $310{\rightarrow}148$ for internal standard. Linear detection responses were obtained for paroxetine concentration range of 0.02~5 ng/mL. A correlation coefficient of linear regression ($R^2$) was 0.9993. Detection of paroxetine in canine plasma was accurate and precise, with limit of quantification at 0.02 ng/mL. The method has been successfully applied to pharmacokinetic study of paroxetine in healthy beagle dogs.

Simultaneous analysis of residual glucocorticoids in egg by LC/MS/MS (LC/MS/MS를 이용한 계란 중 잔류 글루코코티코이드의 동시분석)

  • Jang, Mi-Ae;Myung, Seung-Woon
    • Analytical Science and Technology
    • /
    • v.22 no.4
    • /
    • pp.326-335
    • /
    • 2009
  • A specific analytical method able to identify and quantify traces of six glucocorticoids residues in eggs were developed. The extraction and clean-up parameters for simultaneous analysis were evaluated and HPLC and spectrometric conditions were also established. For determination of glucocorticoids, 5 g of egg was transferred into a test tube, adjusted pH 5.2 with acetate buffer and was $\beta$-glucuronidase/arylsulfatase from Helix pomatia added. The mixture was centrifuged and supernatant was extracted twice with 20 mL n-hexane. The extraction was performed with HLB cartridge using methanol, followed by clean-up with silica cartridge using methanol/ethyl acetate (4/6, v/v). The analytes were determined by HPLC/ESI-MS/MS operating in the negative ion mode. Validation studies with fortified egg samples for established method were performed. The result of method validation gave good efficiency, linearity, accuracy and precision. The correlation coefficients ($r^2$) of the calibration curves appeared to be higher than 0.99 in egg, indicating excellent linearity. LOD was ranged 0.09 to $0.17{\mu}g/kg$, and recoveries for most compounds were in the range of 55.7-69.8%. This method can be used to determine ${\mu}g/kg$ levels of glucocorticoids in eggs.

Qunatitative analysis of liquiritin and glycyrrhizin in glycyrrhizae radix by HPLC-MS/MS (HPLC-MS/MS에 의한 감초의 liquiritin과 glycyrrhizin의 분석)

  • Yu, Young-Beob;Kim, Mi-Jung;Huang, Dae Sun;Ha, Hye-Kyeong;Ma, Jin-Yeul;Shin, Hyeun-Kyoo
    • Analytical Science and Technology
    • /
    • v.20 no.4
    • /
    • pp.331-338
    • /
    • 2007
  • Licorice, Glycyrrhizae Radix is widely used as a herbal medicines and a dietary supplements in East Asia. We employed high performance liquid chromatography electrospray ionization tandem mass spectrometry to determine liquiritin and glycyrrhizin in the Glycyrrhizae Radix. Liquiritin and glycyrrhizin in Glycyrrhizae Radix were ionized by positive ion pneumatically assisted electrospray and detected by HPLC-MS/MS in the multiple-reaction monitoring (MRM) mode using precursor ${\rightarrow}$ product ion combinations at m/z $436.2{\rightarrow}257.0$ and $823.4{\rightarrow}453.4$, respectively. The assay had a calibration range from 10 to 3,000 ng/mL. The limits of detection (LOD) of the liquiritin and glycyrrhizin were 0.4 ng/mL and 0.01 ng/mL, respectively. The reproducibility and repeatability (relative standard deviation) at different analyte concentrations varied from 103 to 113 % and 0.95 to 1.8 %, respectively. According to the above results, HPLC-MS/MS method permits assignment of tentative structures such as liquiritin and glycyrrhizin in the Glycyrrhizae Radix.

The Estimation of Soil Moisture Index by SWAT Model and Drought Monitoring (SWAT 모형을 이용한 토양수분지수 산정과 가뭄감시)

  • Hwang, Tae Ha;Kim, Byung Sik;Kim, Hung Soo;Seoh, Byung Ha
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.4B
    • /
    • pp.345-354
    • /
    • 2006
  • Drought brings on long term damage in contrast to flood, on economic loss in the region, and on ecologic and environmental disruptions. Drought is one of major natural disasters and gives a painful hardship to human beings. So we have tried to quantify the droughts for reducing drought damage and developed the drought indices for drought monitoring and management. The Palmer's drought severity index (PDSI) is widely used for the drought monitoring but it has the disadvanges and limitations in that the PDSI is estimated by considering just climate conditions as pointed out by many researchers. Thus this study uses the SWAT model which can consider soil conditions like soil type and land use in addition to climate conditions. We estimate soil water (SW) and soil moisture index (SMI) by SWAT which is a long term runoff simulation model. We apply the SWAT model to Soyang dam watershed for SMI estimation and compare SMI with PDSI for drought analysis. Say, we calibrate and validate the SWAT model by daily inflows of Soyang dam site and we estimate long term daily soil water. The estimated soil water is used for the computation of SMI based on the soil moisture deficit and we compare SMI with PDSI. As the results, we obtained the determination coefficient of 0.651 which means the SWAT model is applicable for drought monitoring and we can monitor drought in more high resolution by using GIS. So, we suggest that SMI based on the soil moisture deficit can be used for the drought monitoring and management.

Correction for Membrane Penetration Effect during Isotropic Unloading and Undrained Cyclic Shear Process (등방제하과정과 반복전단과정에서의 멤브레인 관입량 및 보정식에 대한 실험적 고찰)

  • Kwon, Youngcheul;Bae, Wooseok;Oh, Sewook
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.3C
    • /
    • pp.201-207
    • /
    • 2006
  • Soil tests are generally conducted using a membrane to measure a pore water pressure. However, it has also been recognized that the membrane penetrates into the specimen by the change of the confining pressure, and it results in the erroneous measurement in the pore water pressure and the volumetric strain. This study examined the effectiveness of the correction equation of the membrane penetration on the basis of the experimental data acquired during the isotropic unloading and the cyclic shear process using the hollow cylindrical shear test equipment. The results showed that the membrane penetration by the correction equation could be overestimated when the mean effective stress was lower than 20kPa in this study. The limitations originated from the sudden increase near the zero effective stress, and in order to prevent the overestimation in low effective stress condition, the use of the constant a was proposed in this study. Furthermore, the correction equation for the membrane penetration had to be applied carefully when the initial relative density was high and the density changes were occurred by the relocation of the soil particle by the liquefaction.

Development of Temperature Compensated Micro Cone by using Fiber Optic Sensor (광섬유를 이용한 온도 보상형 마이크로콘의 개발)

  • Kim, Raehyun;Lee, Woojin;Yoon, Hyung-Koo;Lee, Jong-Sub
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.29 no.4C
    • /
    • pp.163-174
    • /
    • 2009
  • Mechanical device using the load cell or strain gage sensor can be influenced by tempearute changes because temperature change can cause a shift in the load cell or straing gage output at zero loading. In this paper, micro cone penetrometers with 1~7mm in diameter, are developed by using an optical fiber sensor (FBG: Fiber Bragg Grating) to compensate the continous temperature change during cone penetration test. Note the temperature compensated method using optical fiber sensor which has hair-size in diameter, and is not affected by environmental conditions because the measured data is the wavelength shifting of the light instead of the intensity of the electric voltage. Temperature effect test shows that the output voltage of strain gage changes and increases with an increase in the temperature. A developed FBG cone penetrometer, however, achieves excellent temperature compensation during penetration, and produces continuous change of underground temperature. In addition, the temperature compensated FBG cone shows the excellent sensitivity and detects the interface of the layered soils with higher resolution. This study demonstrates that the fiber optic sensor renders the possibility of the ultra small size cone and the new fiber optic cone may produce more reliable temperature compensated tip resistance.

An Explorative Study on Theoretical Potential of Critical Realism as Social Welfare Paradigm (사회복지 패러다임(paradigm)으로서 비판적 실재론의 가능성에 대한 탐색적 연구)

  • Woo, Ah Young;Kim, Giduk
    • Korean Journal of Social Welfare Studies
    • /
    • v.44 no.2
    • /
    • pp.465-497
    • /
    • 2013
  • This paper criticizes the ontological and epistemological dichotomy in social sciences including social welfare and probes into Critical Realism as an alternative paradigm. Many theories for social welfare have adhered to dichotomous ontological standpoint, 'agency' vs. 'social structure', and Eco-system approach have occupied dominant position to integrate this dichotomy. These theoretical standpoint have had great influence on social work practice. On the other hand, dichotomous epistemological standpoint which is constituted of different views of phenomena, 'positivism' and 'constructionism', have had great influence on social work research and practice. These dichotomous ontological and epistemological approach have a limit to reveal qualitative nature of the relationship between agency and social structure, to ponder the deeper reality, the mechanism of stratified reality, and the reality being independent of agency. Replacing these approaches, Critical Realism unfold the theoretical potential as an alternative paradigm for social welfare through the discussion on stratified realty(the empirical, the actual, and the real), intransitive/transitive dimension, double hermeneutics in these dimensions, and the conditions for conceptualization, duality of structure and practice, transformation model of agency and structure.

Participatory Action Research on Changing of Poor Single Mother Self-help Group (빈곤 한부모여성 자조집단의 변화에 관한 참여실행연구)

  • Kim, Eun-jeong;Kim, Hyun-jin;Oh, Bo-ram
    • Korean Journal of Social Welfare Studies
    • /
    • v.41 no.1
    • /
    • pp.5-37
    • /
    • 2010
  • The purpose of this study is to see the motive, processes and strategies of change in poor single mother self-help group and analyze meaning in the self help group, agencies and themselves by change. As to this discussion, We seek to grope practical ways for self-help group. By using Participatory Action Research, We intended to an alternative plan in collaborating between practitioners and all concerned. Following four-step-process in this methodology, we explored processes of changing and considered social work practical meaning. On results, first, The motive have come from critical minds that motivate them to choose their way subjectively. We concluded that they have a necessity of change as a groping activity within their capability. Second, On process trying to be changed, They have made initiative decisions about how extensive and deep their changes should be, by discussion being themselves. So they have agreed to aim at purposeful activities beyond just emotional support. Third, they suggested and planned meaningful action as a specific strategy for changing and all these were done by local community volunteering and lecturing for supporting single mother. In conclusion, The 'Change' single mother group activity aim at is, based on subjective decision, to change a practice of a social worker into a practice of participant, and to develop social empowerment more improved to control social condition, which is forming their life, by their own choice. Furthermore, It needs to be considered approach to Community for overcome limits of self help group activities. Based on these consequences, We presented social work practical meaning.

The Role of Attitude Importance in Cultural Variations of Cognitive Dissonance (인지부조화의 발생에서 문화 차이의 의미: 태도 중요도의 역할)

  • Sangyeon Yoon;Shinhwa Suh;Hyunjeong Kim;Taekyun Hur
    • Korean Journal of Culture and Social Issue
    • /
    • v.19 no.1
    • /
    • pp.69-86
    • /
    • 2013
  • The recent findings proposed and found that people from Eastern cultures could experience strong cognitive dissonance only when certain conditions, such as other-related choices, normative attitudes, were fulfilled. Even though such interesting findings are intuitively convincing on the basis of common understanding of individualist and collectivist cultures, the psychological mechanisms underlying the cultural variations of cognitive dissonance remain untested. The present study examined the role of attitude importance in cognitive dissonance by using the free-choice paradigm. After completing a pretest of individualism-collectivism scales, 60 college students ranked their preference to 10 items of either beverage or traffic regulations twice. Between the two ranking tasks, they were asked to engage in behavioral selection among their 5th and 6th preferred items. They also rated the personal importance of the preference. The results showed that attitude importance was positively correlated with attitude change and it could play a major role in experiencing cognitive dissonance beyond cultural orientation and situational factors. The current findings were discussed in universality of cognitive dissonance across cultures.

Looking into Child-rearing Experience of Mothers from Multicultural Families through the Grounded Theory Paradigm Model (근거이론 패러다임 모형으로 다문화가정 어머니의 자녀양육경험 들여다보기)

  • Oh, Ok Sun ;Kim, Sung Bong
    • Korean Journal of Culture and Social Issue
    • /
    • v.18 no.2
    • /
    • pp.235-260
    • /
    • 2012
  • This study was aimed at looking into and understanding child-rearing experience of mothers from multicultural families based on the grounded theory, one of the qualitative research methods. For this, twelve mothers from multicultural families were selected and data were collected through in-depth interviews with them and then analyzed through the open coding, axial coding and selective coding. The analysis suggested that main phenomena mothers from multicultural families experienced are the conflict of child-rearing and educational crisis, and the confused identity of parenting. These main phenomena had much to do with contextual factors such as economic hardship, lower level of the Korean language, cultural differences, prejudices and ignorance. The severeness of conflict and crisis of child-rearing and the intensity of identity confusion for parenting depended on arbitral conditions such as family bonds, positive expectation for the future of their children, and the help of supportive systems. Mothers were dealing with difficulties of child-rearing through action and interaction of resignation and denial, introspection and the intention to overcome difficulties, and the capacity building. As a result, mothers from multicultural families acknowledged that there is a limit to their position and roles they can play and tried to change in order to resolve problems related to their children, positioning themselves for more active lives in Korean society. Through discussion based on the findings of the study, this study can help better understand child-rearing experience of mothers from multicultural families and suggest several directions for future researches on multicultural families.

  • PDF