49 research outputs found
Onychomatricoma masquerading as candidal onychomycosis and paronychia
Onychomatricoma is a benign slow-growing fibroepithelial tumor arising from the nail matrix. The tumor has been described as a new entity almost two decades ago. Although the clinical appearance is typical, most cases are probably misdiagnosed by physicians because of unfamiliarity with the condition. Herein we describe a case of onychomatricoma masquerading as candidal onychomycosis and paronychia and treated erroneously as such. We believe that OM is still an unrecognized entity and probably more common than cited in the relevant literature. Awareness of the condition not only offers accurate diagnosis and appropriate management but also precludes the long-term use of potentially toxic oral antifungal medications. </span
Demographic Analysis of Renal Failure Patients Presenting to the Emergency Unit
BackgroundThe incidence and mortality of renal failure remain high. Dialysis continues to be a major supportive intervention in renal failure, but late referral is associated with the risk of higher morbidity and mortality.MethodsWe investigated the demographic data of renal failure patients requiring dialysis who presented to our emergency unit between August 2003 and June 2005. Demographic characteristics, presentation complaints, current treatment, initial laboratory values and vascular access type were determined.ResultsNinety patients (52 male, 38 female; mean age, 56.63 ± 17.33 years) were included in the study. The most common presenting complaints were dyspnea, weakness and edema. Twenty (22.2%) patients had acute renal failure and the other 70 patients had chronic renal failure. Only seven (7.7%) patients had the necessary documents for dialysis treatment, and only six patients had available radial arteriovenous fistula. During follow-up, eight (8.8%) patients died. We found inadequate hemodialysis readiness in our end-stage renal disease patients.ConclusionImproving the quality of pre-dialysis care might improve long-term survival, so appropriate timing for nephrology referral is important in patients with end-stage renal disease. [Hong Kong J Nephrol 2007;9(2): 82–5
TRİPLE NEGATİF MEME KANSERLİ HASTALARDA STAT-3, FOSFORİLE STAT-3, P38 MAP-KİNAZ VE FOSFORİLE P38 MAP-KİNAZ EKSPRESYONLARI VE BU EKSPRESYONLARIN PROGNOSTİK DEĞERİ
AMAÇ: Triple negatif meme kanserleri biyolojik olarak diğer meme kanserlerinden farklılık göstermektedir. Bu tez çalışmamızda, meme kanserlerinde agresif seyirle ilişkili olabilecekleri düşünülen STAT-3, p38 MAPK ve EGFR ekspresyonlarının triple meme kanserlerindeki ekspresyon patternlerini ve bunun prognostik önemini araştırmayı amaçladık. HASTALAR VE METOD: Çalışmaya 56 triple negatif meme kanserli hasta alındı. Kontrol grubu olarak 20 Östrojen ve progesteron reseptörü pozitif, cerb B2 negatif ve 20 östrojen ve progesteron reseptörü negatif, cerbB2 pozitif meme kanserli hasta alındı.
SONUÇLAR: Triple negatif hastaların 31‟inde (%55.4) sitoplazmik STAT-3 ekspresyonu gözlenirken, hiç bir hastada nükleer ekspresyon saptanmadı. Hastaların 14‟ünde (%25) fosforile stat-3 için sitoplazmik ekspresyon ve 10‟unda (%17.9) nükleer ekspresyon gözlendi. On üç hastada (%23.2) sitoplazmik, 9‟unda (%16.1) ise nükleer p38MAPK ekspresyonu gözlendi. Fosforile p38 MAPK ile nükleer tarzda boyanma izlenmezken, sitoplazmik ekspresyon hastaların 13‟ünde (%23.2) gözlendi. EGFR ekspresyonu hastaların 10‟unda (%17.9) saptandı. Triple negatif hastalar ile triple negatif olmayan hastalar karşılaştırıldğında, daha sık
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sitoplazmik STAT-3 ve nükleer fosforile STAT-3 ekspresyonları gösterdikleri gözlendi. Bazal-benzeri tümörlerde bazal olmayan tümörlere göre sitoplazmik STAT-3 ve fosforile STAT-3‟ün nükleer ekspresyonu daha sıktı. Nod pozitif triple negatif hastalarda fosforile STAT-3 nükleer ekspresyonları daha fazlaydı. EGFR ekspresyonu ile sitoplazmik STAT-3 ekspresyonu ve sitoplazmik p38 MAPK ekspresyonları arasında korrelasyon saptandı. EGFR ekpsresyonu, azalmış hastalıksız sağkalım ile ilişkili iken, toplam sağkalımda fark yoktu. TARTIġMA: Tez çalışmamızda sitoplazmik STAT-3 ve fosforile STAT-3‟ün nükleer ekspresyonun triple negatif tümörlerde triple negatif olmayan tümörlere göre daha fazla olduğunu ve bu tümörlerde EGFR yolağının Stat-3 ve p38 MAPK yolaklarının ile yakın ilişki içinde olduklarını saptadık. Bu markırların prognostik öneminin tam olarak ortaya konulabilmesi için uzun dönem takip sonuçlarının beklenmesi gereklidir.AIM: Triple negative breast cancers behave diffrently from other breast cancers. In this study, we aimed to investigate the expressions and prognostic significance of STAT-3, p38 MAPK ve EGFR in triple negative breast cancers which may be related with agressive clinical behaviour. PATIENTS AND METHODS: Fifty six triple negative breast cancer patients were taken into the study. Twenty ER/ PR positive, cerb B2 negative and 20 ER/PR negative, cerb B2 positive breast cancer patients were chosen as control group.
RESULTS: In 31 of patients (55.4%) cytoplasmic STAT-3 expression was detected. Fourteen (%25) patients had cytoplasmic and 10 patients (17.9%) had nucleer phosphorylated STAT-3 expressions. In 13 patients (23.2%) cytoplasmic and in 9 patients (16.1%) nucleer p38 MAPK expressions were observed. Cytoplasmic fosforile p38 MAPK expression was present in 13 patients (23.2%) while no nucleer expression was detected. EGFR expression was observed in 10 patients (17.9%). Triple negative breast cencer patients had more commonly expressed cytoplasmic STAT-3 and nucleer phosphorylated STAT-3 compared to controls. Similarly, cytoplasmic STAT-3 and nucleer phosphorylated STAT-3
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expressions had more commonly detected in basal like tumors. Nucleer phosphorylated STAT-3 expression was higher in node positive patients. EGFR expression was correlated with cytoplasmic STAT-3 and cytoplasmic p38 MAPK expressions. Patients with EGFR expression had shorter DFS times while there was no difference in overall survival. CONCLUSION: We found cytoplasmic STAT-3 and nucleer phosphorylated STAT-3 were more commonly expressed in triple negative tumors. EGFR cascade was found in a close relation with STAT-3 and p38 MAPK pathways in these tumors. However, longer follow-up periods are required to evaluate the exact impact on prognosis
Why Do Students Remember Some Teacher-Generated Analogies More Than Others?
PageAbout EERAConferencesNetworksSeason SchoolsPublicationsAbstractsBreadcrumb NavigationWhy Do Students Remember Some Teacher-Generated Analogies More Than Others?Main ContentEmel Ünver SezerBehiye UbuzConference:Format:ContributionThe notion of function, which is considered to be fundamental to the development of mathematical knowledge and knowledge in other subject areas in school-curriculum, is so abstract and it has been found notoriously difficult for most students (Cuoco, 1995). The understanding of function concept does not appear to be easy, since the diversity of representations refer to different ways of thinking and communicating with others including verbal (spoken), written, kinesthetic (enactive), colloquial (informal or idiomatic), notational conventions, numeric, symbolic, and geometric (visual) aspects (DeMarois &Tall, 1996). An essential goal of mathematics teaching is that students be able to pass from one representation to another without falling into contradictions (Hitt, 1998). Kaput (1994) mentioned that although the representation of functions is useful for interpreting physical, social and mathematical phenomena, it is complex for students to apply concepts or ideas learned in the school mathematics in a new situation in or out of school. Because, there is a gap between mathematical functions defined in algebraic formulas and empirical functions explaining everyday phenomena (Kaput, 1994; Richland & Begolli, 2016). Since their ability to transfer representations across contexts, analogies (colloquial representation) have long been thought to have a central role in mathematics learning and teaching. Although there are many definitions of analogy in the literature, basically, an analogy is defined as a mapping of knowledge from one domain (familiar) into another (unfamiliar) (Gentner & Gentner, 1983). In other words, they are used to make unfamiliar familiar (Treagust, Duit, Joslin &Lindauer, 1992). In the literature, the familiar domain is referred as the “vehicle”, “base”, “source”, or “analog”; and the less familiar domain or the domain to be learned is referred to as “topic” or “target”.The use of analogies in teaching and learning of function concept have received attention from mathematics educators (see, for example, Bayazit & Ubuz, 2008; Ubuz et al., 2009; Ünver, 2009; Ubuz, Özdil & Çevirgen, 2013). Bayazit and Ubuz (2008) researched the effectiveness of analogies in the teaching and learning of function concept. Ubuz et al (2009) discussed whether or not pre-service teacher-generated analogies are epistemologically appropriate to show the essence and the properties of the functions. Ünver (2009) examined how analogies are used on the function concept in the ninth grade mathematics textbooks and classrooms. Although, there have been relatively few studies reported about the way of teachers and textbooks using analogies or about the effectiveness of pre-service and in-service teacher-generated analogies to teach functions, to date, no research has been done on how students use analogies to learn or on how they perceive and how much they remember about teacher-generated analogies used in lessons on the concept of functions. There is no doubt that teachers employ analogies with the intention of promoting student understanding of function concept, however, their uses of analogies may not always correlate with students or may not make sense to them.Taking into account all these considerations, it is felt that it is essential to search how students perceive or remember teacher-generated analogies. The purpose of the current study is to determine the possible reasons for students remembering some teacher-generated analogies more than other teacher-generated analogies. Current study scrutinizes the results obtained as part of a larger study in which the following research questions were addressed: “ What are the 9th-gradestudents’ perceptions of the effectiveness and the utility of analogies that their teachers employed during function concept teaching? Here, the sub-question is dedicated: “Why do 9th-gradestudents remember some teacher-generated analogies more than other teacher-generated analogies?MethodTo gain a deeper insight into why students recall some analogies more than others, one-to-one videotaped interviews were made with students. This study is a part of a larger research agenda containing an observation of 91 mathematics lessons of two ninth-grade mathematics teachers (T1 and T2) and their 121 students, of which the interview participants were a sub-sample to understand instructional analogies and their influence on analogy use of ninth grade students. Fourteen (7 males and 7 females) ninth-grade students (S1-S14) from five different classes of the same private high school located in the Anatolian part of Istanbul, voluntarily participated in the interviews. The first four were from the classes (A, B) of T1 and the remaining ten were from the classes (C, D, E) of T2. Interviews were held at the students’ school over five weeks observation period. The individual interviews were semi-structural, conversational and continued nearly one hour. Two questions were posed in the interviews in the order were: (1) Identify one analogy that was used by your teacher (2) Why did you select this analogy? During the interview, both of the questions were posed to the students in a flexible manner. All the interviews were transcribed verbatim and all responses were analyzed to yield data using an inductive qualitative process of review, coding, and identification of semantic themes (Bogdan & Biklen, 1992). Data analysis process first started with getting transcriptions then continued with reading transcripts through several times to search for similarities and differences between them. In this process, initial categories describing the different reasons for recalling analogies were developed. Then, to decide whether or not they are adequately indicative of the data, initial categorization was modified by addition or deletion some of the descriptions. This process was followed until forming a coding scheme containing more general categories. Following the analysis, the frequency of each category was identified. This coding scheme consisted of nine categories given in result part. Each student’s interview data was examined and classified separately by two researchers, with an original agreement was being achieved. The title of the mathematics unit during the study carried out was “Functions”. The unit of the study consisted of three main parts: (a) function concept (b) graphs of functions, and (c) function types (polynomial, rational, irrational, constant, identity, linear, piecewise, one to one and onto functions).Expected OutcomesDuring the interviews, almost all students (except S8) identified one or two analogies with underlying reasons. Student-identified analogies (A1-A9) with their specified analogs and targets can be listed in order from most to least among students shown inside of the brackets: A1: “Calculation of water bills regarding to personal use with municipality fee” analog with “function concept” target (S5, S7, S9, S10)”, A2: “Specification profits of a hotel by month” analog with “function concept” target (S11, S13), A3: “Specification profits of a hotel by month” analog with “piecewise function” target (S12), A4: “Tomato juice machine” analog with “function concept” target (S2, S4), A5: “Tomato fabric” analog with “function concept” target (S1)”, A6: “Tomato sauce machine” analog with “function concept” target (S3), A7: “Constant speed car” analog with “constant function” target (S5), A8: “Function machine” analog with “function concept” target (S6) and A9: “Cab fare” analog with “function concept” target (S14). Categorization obtained from students’ expressed reasons consisted of nine categories: mathematical/containing numerical expressions (A1, A3, A5, A8), to think applicable (A1, A2, A5), simple/intelligible (A1, A4), to help understanding (A1, A3, A4, A6), to remember/recall information (A2, A6), repeated (A2, A4), useful for later learning (A1, A8), attention-grabbing (A8), as personal interest (A2, A8, A9). Based on the data presented above, the most common reason for remembering the selected analogy was that they helped to understand. In the second order, it followed by that they were mathematical or containing numerical expressions and were thought as applicable. Differently, S6, S13, and S14 mentioned the reason that they were related to their personal interests (business life/commerce, economy, and financial matters). Lastly, S6 mentioned that the reason for remembering analogies based their attention-grabbing property, on the other side; S8 based her for not remembering any analogies to the same reason.ReferencesBayazit, İ., & Ubuz, B. (2008). Instructional analogies and student learning: The concept of function. In Proceedings of International Group for the Psychology of Mathematics Education, (pp.145-152). Morelia, Mexico: Centre for Research and Advanced Studies of Saint Nicholas. Bogdan, R., & Biklen, S. (1992). Qualitative research for education: An introduction to theory and methods . Nedham Heights, MA: Allyn & Bacon. Cuoco, A. (1995). Computational media to support the learning and use of functions. In A. diSessa, C. Hoyles, & R. Noss (Eds.), Computers and exploratory learning (pp. 79–108). Springer. DeMarois, P. and Tall, D. (1996) ‘Facets and layers of the function concept’, in Puig, L. and Gutiérrez, A. (eds), Proceedings of the 20th Conference of the International Group for the Psychology of Mathematics Education, 2, Valencia, Spain, pp. 297-304. Gentner, D., & Gentner, D. R. (1983). Flowing waters or teeming crowds: Mental models of electricity. In D. Gentner & A. L. Stevens (Eds.), Mental models (pp. 99-129). Hillsdale, NJ: Erlbaum. Hitt, F. (1998). Difficulties in the articulation of different representations linked to the concept of function. The Journal of Mathematical Behavior, 17(1), 123- 134. Kaput, J. (1994). The representational roles of technology in connecting mathematics with authentic experience. In Biehler, R. et. al. (eds.) Mathematics didactics as a scientific discipline. Richland, L. E., & Begolli, K. N. (2016). Analogy and higher order thinking: learning mathematics as an example. Behavioral and Brain Sciences, 3(2), 160-168. Treagust, D.F., Duit, R., Joslin, P. & Landauer, I. (1992). Science teachers’ use of analogies: Observation from classroom practice. International Journal of Science Education 14: 413– 422. Ubuz, B., Eryılmaz, A., Aydın, U., & Bayazıt, I. (2009). Pre-service teacher generated analogies for function concepts. In V. Durand-Guerrier, S. Soury-Lavergne ,& F. Arzarello (Eds.) Proceedings of the Sixth Congress of the European Society for Research in Mathematics Education (pp.1871-1879). Lyon: France. Ubuz, B., Özdil, U., & Çevirgen, A. E. (2013). Preservice teachers' knowledge and beliefs: Their association to practice in the context of teaching function with analogies. In B. Ubuz, Ç. Haser, & M. A. Mariotti (Eds.), Proceedings of the Eighth Congress of the European Society for Research in Mathematics Education (pp. 3277-3286). Antalya: Turkey. Ünver, E. (2009). Analysis of analogy use on function concept in the ninth grade mathematics textbook and classrooms. Unpublished Master's Thesis, Middle East Technical University. Turkey
Investigation of Radiation Effects on Coffee Beans Using ESR Technique
In
this study, radiation effects on coffee beans have been investigated by Electron Spin Resonance (ESR) technique. ESR spectra of natural and irradiated samples at different
doses between 0.5 Gy and 11 kGy by 60Co gamma source were recorded
with X-band ESR spectrometer and, radiation dose, ESR microwave power and
cavity temperature dependency of paramagnetic centers were investigated. At the
results of dose- response and kinetic studies it was determined that the
paramagnetic centers in coffee beans are stable, and sensitive to radiation.
Thus, it is shown that the irradiated beans can be used for detection as
radiation dosimeter in the investigated dose range