OLIGOMERIC ETHYLENE GLYCOLS AS SORTING TAGS FOR COMBINATORIAL SYNTHESIS

Certain problems associated with the nature of solid phase combinatorial synthesis has prompted the search for alternative methods. Among these, fluorous mixture synthesis (FMS) has emerged as a powerful method for solution phase combinatorial synthesis. In FMS each unique substrate is tagged with a perfluorinated alkane of unique length. These tagged substrates are mixed and taken through the desired synthetic steps. The final products are then subjected to fluorous chromatography. Elution order is directly proportional to fluorous tag length. Thus such fluorous tags could be regarded as sorting tags. Other classes of sorting tags which are separable under orthogonal conditions to those of fluorous tags would significantly increase the potential of this approach. In this study it has been demonstrated that oligomeric ethylene glycol (OEG) derivatives constitute a new class of sorting tags. OEG esters were separable using normal phase high performance liquid chromatography (NPLC). Separation was primarily dictated by OEG chain length with elution order being directly proportional to that length. Within those separatory regions the nature of the parent substrate played a secondary role, further improving separation. It has also been demonstrated that complexation chromatography employing silica gel containing lithium chloride further enhanced peak resolution. OEGylated analogues of benzyl alcohol have been prepared. Reversed phase high performance liquid chromatography has been found to emphasize the chromatographic nature of the parent substrate while still enabling OEG based separation. The elution order with respect to OEG chain length was found to be the opposite of that in NPLC. Enthalpy-entropy compensation has been demonstrated for all OEG chain lengths indicating the same retention mechanism for all of the esters studied. These findings suggest that a two-tier separation approach-first RPLC then NPLC-could significantly increase the number of OEGylated substrates that can be subjected to mixture synthesis. OEGylated Evans Auxiliaries (OEG-EAs) have been prepared and applied to mixture syn-aldol reactions to demonstrate the synthetic utility of OEG-based sorting tags. OEGs have been found to be inert under the reaction conditions employed in the preparation of and application of OEG-EAs. The aldol products were obtained with good yield, high purity and high enantiomeric excess

Effekte und Langzeitstabilität der Behandlung des einseitigen Kreuzbisses vor der zweiten Phase des Wechselgebisses

ZIEL: Ziele dieser retrospektiven Studie waren die Analyse und der Vergleich der Effekte und der Langzeitstabilität nach der Behandlung des einseitigen Kreuzbisses durch eine Gaumennahterweiterung (GNE) oder durch Plattenapparaturen (PA) vor der zweiten Phase des Wechselgebisses. MATERIAL UND METHODE: Digitalisierte Modelle von Patienten, die mit GNE-Apparaturen (n = 15) oder mit Plattenapparaturen (n = 10) erfolgreich therapiert wurden, lagen zu drei Zeitpunkten vor (T1: Vor der Behandlung; T2: Nach der Behandlung; T3: Mindestens drei Jahre nach der Behandlung). Folgende Einschlusskriterien wurden von allen Patienten erfüllt: Einseitiger Kreuzbiss; Behandlungsbeginn vor der späten Wechselgebissphase; keine vorherige oder nachfolgende kieferorthopädische Therapie; keine Lippen-Kiefer Gaumenspalte; kein Syndrom. Die Zahnbogenbreiten wurden zwischen Eckzähnen, Prämolaren und Molaren gemessen. Zusätzlich wurden die anteriore Zahnbogenlänge, die Symmetrie und das Gaumenvolumen bestimmt. Zur statistischen Auswertung innerhalb der Gruppen wurden einfaktorielle Varianzanalysen mit Messwiederholung oder Friedman-Tests durchgeführt. Vergleiche zwischen den Gruppen erfolgten durch t-Tests oder Mann-Whitney U-Tests. Mittels Shapiro-Wilk Tests wurde das Vorliegen einer Normalverteilung überprüft. ERGEBNISSE: Beide Therapiemethoden eignen sich zur Therapie des einseitigen Kreuzbisses. Die Gaumennahterweiterung führte zunächst zu einer signifikant (p < 0,05) größeren Expansion im Bereich der zweiten Molaren der ersten Dentition und der ersten Molaren der zweiten Dentition. Zum Zeitpunkt T3 waren keine signifikanten Unterschiede zwischen den Gruppen mehr feststellbar. Von T1 bis T3 nahm die intercanine und intermolare Distanz um 1,89 ± 1,78mm und 2,60 ± 2,08mm in der PA-Gruppe und 2,30 ± 2,82mm und 2,24 ± 2,04mm in der GNE-Gruppe zu. Das Gaumenvolumen nahm signifikant (p < 0,05) um 1265.30 ± 913.72 mm³ in der PA-Gruppe und 1234.27 ± 989.64 mm³ in der GNE-Gruppe zu. Die anteriore Zahnbogenlänge zeigte keine signifikanten Veränderungen. Die Symmetrieanalyse zeigte signifikante (p < 0,05) Asymmetrien zwischen Eckzähnen und Molaren der ersten Dentition. Rezidive traten in 10% der Fälle in der Gruppe PA und in 20% der Fälle in der Gruppe GNE auf. SCHLUSSFOLGERUNGEN: Der einseitige Kreuzbiss kann sowohl durch Plattenapparaturen als auch durch eine Gaumennahterweiterung in ähnlichem Maße erfolgreich therapiert werden. Beide Apparaturen zeigen eine gute Langzeitstabilität. Die Therapie durch Plattenapparaturen scheint jedoch zu stabileren Ergebnissen zu führen.AIM: The aims of this retrospective study were evaluation and comparison of treatment effects and long-term stability after unilateral posterior crossbite correction in patients treated with rapid maxillary expansion (RME) or with removable plate appliances (PA) before the late mixed dentition. MATERIALS AND METHOD: Digitized dental casts of patients successfully treated with RME (n=15) or with PA (n=10) were available at three time points (T1: before treatment; T2: after treatment; T3: at least three years after treatment). The inclusion criteria were met by all patients: unilateral posterior crossbite; start of treatment before the late mixed dentition; no prior or subsequent orthodontic treatment; no cleft lip and palate; no craniofacial syndromes. Dental arch widths were measured between canines, premolars and molars. Anterior arch length, arch symmetry and palatal volume were also registered. For intragroup statistics, one way repeated measures ANOVA or Friedman tests were used. Comparisons between groups were done using t-tests or Mann-Whitney U-tests. Shapiro-Wilk tests were used to test for normality. RESULTS: Both treatment modalities appeared suitable for crossbite treatment. RME initially led to a significantly (p < 0.05) higher expansion than PA between second primary molars and first permanent molars. At T3, however, no significant differences between the groups remained. From T1 to T3, mean maxillary intercanine and intermolar widths increased by 1.89 ± 1.78 mm and 2.60 ± 2.08 mm in the PA group and by 2.30 ± 2.82 mm and 2.24 ± 2.04 mm in the RME group. Palatal volume increased significantly (p < 0.05) by 1265.30 ± 913.72 mm³ in the PA group and by 1234.27 ± 989.64 mm³ in the RME group. Anterior arch length did not show significant changes. Arch symmetry analysis showed significant (p < 0.05) asymmetries between canines and primary molars. Relapse occurred in 10% of the cases in the PA group and in 20% of the cases in the RME group. CONCLUSIONS: Unilateral posterior crossbites before the late mixed dentition can be treated successfully using removable plate appliances or rapid maxillary expansion with similar results. Favorable long-term stability can be achieved by using either method, though treatment using removable plate appliances appears to produce more stable results

A quest to reveal novel players in nucleotide excision repair: From proteomics to mechanistic insights

Nucleotide excision repair (NER) is a versatile DNA repair pathway that removes a wide range of bulky DNA lesions. It is a complex mechanism requiring the action of at least 30 proteins. It is essential that each step is accurately orchestrated and tightly regulated to ensure efficient repair and maintenance of genomic integrity. Since its discovery more than fifty years ago, NER is already heavily-studied. However current understanding about its spatio-temporal regulation is still limited. In this thesis, we aimed to identify novel NER regulators and found two new factors, HLTF and FACT subunit Spt16, respectively. We report the former to be required for removal of incised DNA fragment including the lesion, and latter to be required for recruitment of TC-NER factor UVSSA to lesion

Müşteri memnuniyet indeks modelinde yapay sinir ağları kullanımı

The concept of customer satisfaction has attracted much attention in recent years. A key motivation for the growing emphasis on customer satisfaction is that higher satisfaction can lead to a stronger competitive position resulting in higher market share and profit, reduce price elasticity, lower business cost, reduce failure cost, and reduce the cost of attracting new customers. The purpose of customer satisfaction index (CSI) models is to measure the quality of the goods and services as experienced by the customers that consume them. The independent and uniform measurement characteristics of the CSI model provide a useful tool for tracking performance and systematic benchmarking over time. A major advantage of the measurement model is the use of generic questions, which are sufficiently flexible to be used across a wide variety of products and services. In this study, a new customer satisfaction index model is developed considering the previous CSI models such as American Customer Satisfaction Index and European Customer Satisfaction Index. The proposed model was applied for Turkish mobile phone sector since the competition in this industry results a dynamic product development and an increasing demand for that products. CSI models are designed as a structural equation model (SEM) which consists of well established theories and approaches in customer behaviour. The constructs of the CSI models are latent variables indirectly described by a block of measurement variables. The structural model of the proposed CSI consists of 6 latent variables with their 23 observable variables. The latent variables of the model are company image, customer expectations, perceived quality, perceived value, customer satisfaction and customer loyalty. A survey instrument, developed to measure the manifest variables, was conducted to 700 mobile phone users. Besides the model questions, some demographic questions (e.g. age, gender, education level etc.) are also included in the survey. The structural model of the present model is analyzed using variance based Partial Least Squares (PLS) method. The main concern of the PLS is related to the explanatory power of the path model along with the significance level of standardized regression weights. An iterative scheme of simple and/or multiple regressions contingent on the particular model is performed until a solution converges on a set of weights. The general applicability of a SEM model depends on the reliability and validity of the modelling results. Reliability and validity of the proposed CSI model were assessed by checking unidimensionalty of the blocks, individual item reliability, convergent validity and discriminant validity. All test results satisfy the crucial requirements for validity and reliability of structural model. In this study, a feed forward neural network model is proposed as an alternative to simple or multiple regression methods for the inner model estimation of the CSI. The use of artificial neural networks (NN) gained popularity in different fields, and some studies have demonstrated the superiority of NN over multiple regression. NN simulates human cognition by modelling the inherent parallelism of neural circuits in the brain using mathematical models of how the circuits function. However, the NN approach has been applied more recently to customer satisfaction and loyalty analysis. In this study there are 5 different inner models estimating 5 different endogenous latent variables of the CSI model. Each inner model was estimated using three-layer feed forward neural networks. A sigmoid function is used in the hidden layer, and a linear function in the output layer. The data was divided into two sets, 75 percent for training, and 25 percent for testing. Training is performed using the Levenberg Marquardt back propagation algorithm, and the weights are initialized using Nguyen Widrow algorithm. After the NN is trained it was evaluated for the test data. Root mean squared error and R square scores were used as performance criteria. The use of NN provides a powerful estimation for the inner models used in the CSI. The results of the CSI model as a whole can be a valuable guide for the managers in formulating competitive marketing strategies. Considering the results of the CSI model, the limited resources of the firms can be allocated for critical factors which have important impacts on satisfaction. In conclusion, the CSI model provides important information for the purchase decisions of the customers and lead to improvements in the quality of goods and services they consume. Keywords: Customer satisfaction index, partial least squares, neural networks. M&uuml;şteri memnuniyet indeks modelleri son yıllarda bir&ccedil;ok &uuml;lkede yaygın olarak uygulanmaktadır. M&uuml;şteri memnuniyet indekslerinin en b&uuml;y&uuml;k &ouml;zelliği yapısındaki &ouml;l&ccedil;&uuml;m fakt&ouml;rlerinin &uuml;r&uuml;n ve hizmet sekt&ouml;r&uuml;nde rahatlıkla kullanılabilmesine &nbsp;imkan sağlamasıdır. Bu sayede g&uuml;venilir bir &ouml;l&ccedil;ekle firmalar arasında, sekt&ouml;rler arasında ve &uuml;lke &ccedil;apında karşılaştırmalı bir memnuniyet &ouml;l&ccedil;&uuml;m&uuml; m&uuml;mk&uuml;n olmaktadır. M&uuml;şteri memnuniyet indeks modelleri, m&uuml;şteri memnuniyeti ile ilişkili gizli (latent) değişkenler ve bu gizli değişkenleri &ouml;l&ccedil;en &ouml;l&ccedil;&uuml;m değişkenleri arasındaki ilişkilerden oluşan yapısal eşitlik modelleridir. Bu &ccedil;alışmada diğer &uuml;lkelerde kullanılan m&uuml;şteri memnuniyet indeks modellerinden yola &ccedil;ıkarak &uuml;lkemiz şartlarında kullanılabilecek bir m&uuml;şteri memnuniyet indeks modeli geliştirilip test edilmiştir. Model, 6 gizli değişken ve bunlara bağlı toplam 23 &ouml;l&ccedil;&uuml;m değişkeninden oluşmaktadır. Modele uygun olarak hazırlanan anket formu kullanılarak, cep telefonu sekt&ouml;r&uuml;nde 700 kullanıcı ile y&uuml;z-y&uuml;ze anket uygulaması yapılmıştır. M&uuml;şteri memnuniyet indeks modelindeki gizli değişkenler ve &ouml;l&ccedil;&uuml;m değişkenleri arasındaki ilişkiler kısmi en k&uuml;&ccedil;&uuml;k kareler y&ouml;ntemiyle tahmin edilmiştir. M&uuml;şteri memnuniyet indeks modelinin g&uuml;venilirlik ve ge&ccedil;erlilik test sonu&ccedil;ları modelin genel uygulanabilirliğini g&ouml;stermektedir. &Ccedil;alışmada ayrıca, gizli değişkenler arası ilişkilerin oluşturduğu i&ccedil; modellerin tahmininde Yapay Sinir Ağları (YSA) metodu &ouml;nerilmiştir. Yapısal modeller i&ccedil;in tasarlanan YSA modeli 3 katmanlı ileri beslemeli ve geri yayılımlı bir modeldir. Gizli katmanda sigmoid transfer fonksiyonu, &ccedil;ıkış katmanında ise doğrusal transfer fonksiyonu kullanılmıştır. Bu şekilde 5 farklı i&ccedil; modelin tahmini i&ccedil;in yapay sinir ağları metodunun kullanımı modellerin a&ccedil;ıklayıcılık g&uuml;c&uuml;n&uuml; artırmıştır.&nbsp;Anahtar Kelimeler: M&uuml;şteri memnuniyet indeksi, kısmi en k&uuml;&ccedil;&uuml;k kareler, yapay sinir ağları.&nbsp

Antifungal susceptibilities and identification of Candida species by using maldi-tof microbial identification system from cervicovaginal samples

Background: Among the vaginal diseases seen in women, candidiasis is in the first place. This disease, which is caused by Candida species, can sometimes persist very stubbornly. The aim of this study was to determine Candida species isolated from vaginal specimens by using VITEK MS (MALDI-TOF Microbial Identification System) rapid identification system and to evaluate their susceptibility to some antifungals.Methods: In this study, 220 cervicovaginal swab were used. Isolates were identified by VITEK MS rapid identification system. After identification, antifungal susceptibility testing was performed using the M-44 A2 guideline of The Clinical and Laboratory Standards Institute (CLSI).Results: Total 16.3% (36) of Candida spp. positivity was determined from 220 cervicovaginal samples, and 25 (69.4%) C. glabrata, 6 (16.7%) C. albicans, 3 (8.3%) C. kefyr and 2 (5.6%) C. krusei were obtained with Vitek MS. All identified C. albicans strains were found to be completely resistant to all antifungals used except nystatin agent, C. krusei strains were found to be resistant to flucytosine but sensitive to all other antifungals, C. glabrata and C. kefyr strains were susceptible to all antifungals within the antifungals used in this study.Conclusions: It is concluded that it is necessary to distinguish Candida species in order to apply a correct treatment. And species selection is very important for the selection of antifungal to be used. Nystatin is recommended if no laboratory tests are to be performed for the diagnosis of Vaginal Candidiasis

Effects of Clarification and Storage on Anthocyanins and Color of Pomegranate Juice Concentrates

Whole pomegranates with rinds were processed into juice and then concentrate. Effects of cold clarification and storage temperatures (-23C, 5C, 12C and 20C) on anthocyanins (ACNs), ACN composition and color were determined. Major ACNs in pomegranate juice concentrate (PJC) were identified as cyanidin-3,5-diglucoside (47.9%), delphinidin-3,5-diglucoside (23.2%) and cyanidin-3-glucoside (18.5%). Diglucosides were more stable than monoglucosides during storage. ACN degradation and polymeric color formation were fitted to first-order reaction models. Higher storage temperatures increased the rate of ACN degradation and polymeric color formation in PJCs. Good correlation (r=-0.988) was found between ACN degradation and polymeric color formation during storage. Rate of ACN degradation and polymeric color formation were slower in the PJC obtained from unclarified juice than PJC obtained from clarified juice during storage. © 2012 Wiley Periodicals, Inc