Structural Characterization of Anticancer Drug Paclitaxel and Its Metabolites Using Ion Mobility Mass Spectrometry and Tandem Mass Spectrometry

Paclitaxel (PTX) is a popular anticancer drug used in the treatment of various types of cancers. PTX is metabolized in the human liver by cytochrome P450 to two structural isomers, 3'-p-hydroxypaclitaxel (3p-OHP) and 6 alpha-hydroxypaclitaxel (6 alpha-OHP). Analyzing PTX and its two metabolites, 3p-OHP and 6 alpha-OHP, is crucial for understanding general pharmacokinetics, drug activity, and drug resistance. In this study, electrospray ionization ion mobility mass spectrometry (ESI-IM-MS) and collision induced dissociation (CID) are utilized for the identification and characterization of PTX and its metabolites. Ion mobility distributions of 3p-OHP and 6 alpha-OHP indicate that hydroxylation of PTX at different sites yields distinct gas phase structures. Addition of monovalent alkali metal and silver metal cations enhances the distinct dissociation patterns of these structural isomers. The differences observed in the CID patterns of metalated PTX and its two metabolites are investigated further by evaluating their gas-phase structures. Density functional theory calculations suggest that the observed structural changes and dissociation pathways are the result of the interactions between the metal cation and the hydroxyl substituents in PTX metabolites.1155Ysciescopu

Comparing Results of Five Glomerular Filtration Rate-Estimating Equations in the Korean General Population. MDRD Study, Revised Lund-Malmö, and Three CKD-EPI Equations

Estimated glomerular filtration rate (eGFR) is a widely used index of kidney function. Recently, new formulas such as the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations or the Lund-Malmö equation were introduced for assessing eGFR. We compared them with the Modification of Diet in Renal Disease (MDRD) Study equation in the Korean adult population. METHODS: The study population comprised 1,482 individuals (median age 51 [42-59] yr, 48.9% males) who received annual physical check-ups during the year 2014. Serum creatinine (Cr) and cystatin C (CysC) were measured. We conducted a retrospective analysis using five GFR estimating equations (MDRD Study, revised Lund-Malmö, and Cr and/or CysC-based CKD-EPI equations). Reduced GFR was defined as eGFR <60 mL/min/1.73 m². RESULTS: For the GFR category distribution, large discrepancies were observed depending on the equation used; category G1 (≥90 mL/min/1.73 m²) ranged from 7.4-81.8%. Compared with the MDRD Study equation, the other four equations overestimated GFR, and CysC-based equations showed a greater difference (-31.3 for CKD-EPI(CysC) and -20.5 for CKD-EPI(Cr-CysC)). CysC-based equations decreased the prevalence of reduced GFR by one third (9.4% in the MDRD Study and 2.4% in CKD-EPI(CysC)). CONCLUSIONS: Our data shows that there are remarkable differences in eGFR assessment in the Korean population depending on the equation used, especially in normal or mildly decreased categories. Further prospective studies are necessary in various clinical settings

Strategic Missile Forces in Ukraine: Brief Survey of Past and Present Environmental Problems

Various environmental problems related to the former strategic missile forces located in Ukraine are outlined and analyzed. As the combat units and equipment have been disarmed and mostly utilized according to international agreements, various axiliary units, equipment, parts, stockpiles of the rocket fuel and oxidizer remained in Ukraine outside the agreements

The Encounter of the Self and the World -A Study of Schleiermacher`s Unified I-

본 논문은 독일 낭만주의 철학자 슐라이에르마허의 자아 개념이 지닌 독특한 성격을 탐구함으로써, 어떻게 그의 사상이 칸트와 피히테의 관념론적 주관주의를 극복하면서 동시에 실재 세계와 유기적인 관계 속에 서 형성되어가는 통합된 자아를 설명하고 있는 지를 밝힌다. 슐라이에르 마허에게 자아란 선험적 기초 위에서 움직이는 일방적인 사고 주체가 아니 라 항상 주체와 그에 상응하는 세계 간의 지속적인 상호관계 속에서 끊임 없는 자기 창조적인 과정을 통해 지어져가는 존재이다. 그의 철학적 유산 을 재발견하려는 본 논문의 목적은 첫째, 자아의 능동성을 극대화시킴으로 써 세계와의 유기적 관계에서 가질 수밖에 없는 피동적 영향이라는 요소가 거세된 근대의 주체 개념을 극복함과 동시에 둘째, 다양성을 극대화시킴으 로써 자아의 통합성을 해체시키는 탈근대주의의 또 다른 위험을 비판적인 안목으로 재해석하려는 것이다

Preferred contexts of Korean youth for the learning of school mathematics (grades 8-10)

Philosophiae Doctor - PhDThis study investigated real life situations which learners in South Korea grade 8-10 learners would prefer to be used in school mathematics.This thesis is based on the ROSMEII (Relevance of School Mathematics ducation) questionnaires and interviews, which was used to examine the preferred mathematical learning contexts for South Korean grade 8-10 learners. The study investigates the affective factors that pupils perceive to be of possible relevance for the learning and teaching of mathematic; and is aimed at providing data that might form part of a basis for a local theory of the mathematics curriculum. The standardized ROSMEII survey questionnaire of 23closeended items that relate to some aspects of mathematics on a 4-point Likert-type scale was administered to Korean grade 8-10 learners at the end of compulsory schooling, and mainly 14 to 16 year old cohorts. The data for this study were collected from a sample of 1839 learners drawn from 26 South Korean schools in the year 2009. Interviews were conducted to gauge the pupils‘ preference of the ROSMEII questionnaire contexts and used to validate learners‘ responses. In analyzing their responses, it became clear that, on the average, views expressed were common to all groups of pupils in South Korea (whether male or female, or from the metropolitan, city, or countryside). The clusters of the most preferred mathematical learning contexts are linked to youth culture, which learners are usually and easily engaged with in one way or another. These clusters include the sports, leisure and recreation cluster; planning a journey/popular youth culture cluster the technology cluster; the making of computer games, storing music and videos on CD‘s and Ipods. The lowest preferred mathematical learning contexts are: an agricultural cluster which focuses on agricultural matters and traditional games (yut). In conclusion, this study suggests that teachers should use contexts that increase learners‘ interest in classroom activities. Therefore mathematics curricula and textbooks which are appropriate to this context must be provided in order to provide more efficient mathematics education. It is imperative that the Korean school system must develop a particular program for nurturing learners‘ mathematical power. Furthermore, mathematics education policy makers must reconsider whether the current education system is appropriate, and also listen to learners‘ preferences when designing appropriate mathematics curriculum and textbooks

Preferred contexts for mathematical literacy of Korean grade 8 - 10 learners

Magister Educationis - MEdThe twenty-first century society demands a high level of mathematical literacy. This drove Korean educators to evaluate their students using international mathematics tests such as TIMSS, PISA and IMO. In these tests, Korean students ranked highly among the participating countries. Korean students, however, had done poorly in the application of mathematics in daily life situations as well as in their interest in mathematics in co~parison to those of other countries. Based on these observations, the present study is an investigation on the contexts which Korean grade 8 to 10 students would prefer to deal with mathematics, in order to improve these weak points and thus increase their mathematical power. The aim of this study was thus to investigate mathematical literacy in connection with the relevance of mathematics and mathematical modelling. The study pays more attention to mathematics education 111 real life situations. Data was collected using the ROSME questionnaire that deals with contexts preferred by students for mathematics education. A sample made up of over 1600 learners in grades 8 to 10 were randomly selected from 21 schools. Data collected from these learners was analysed using Kendall's W mean rank method in the SPSS 12.0 program since the data for this study were ordinal. The most important finding of this study was that, "Mathematics that entertains and surprises us" came up the highest ranked item. This indicates that mathematics education must be directed towards raising learners' interests. The lowest ranked item was, "Mathematics used to calculate the number of seats for parliament given to political parties after elections," and this might indicate among other things that political activity does not attract students' interest in a society where the concept of well-being is dominant. In general, Korean learners appear to favour learning mathematics in technological contexts and show less interest in political and agricultural contexts. In conclusion, this study suggests that teachers should use contexts that increase learners' interest in classroom activities. Korea has today become one of the strongest Information Technology countries. Therefore mathematics curricula and textbooks which are appropriate to this context must be provided for more efficient mathematics education. Thus, it becomes imperative that the Korean school system must develop a particular program for nurturing learners' mathematical power. Furthermore, mathematics education policy makers must reconsider whether the current education system, Pyungjunhwa Kyoyuk system, should be used or not