795 research outputs found

    Antimicrobial therapy for otitis media with effusion ( secretory otitis media)

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    Objective. —To determine the effectiveness of antimicrobial treatment for otitis media with effusion ( secretory otitis media) in children. Data Source. —We report the reexamination of a previously published study by Mandel et al that evaluated the efficacy of a 2-week course of antimicrobials (amoxicillin trihydrate) with and without a 4-week course of an oral decongestant-antihistamine combination in a double-blind, placebo-controlled, randomized trial involving 518 infants and children with otitis media with effusion. Data Synthesis. —At 4 weeks, amoxicillin efficacy as determined by a tympanometric criterion (P=.121) or by a measure of improvement in hearing (P=.311) was insignificant. Only by otoscopic judgment, which is shown to contain a systematic bias as used in this clinical trial, could an argument be made for a marginal efficacy of amoxicillin at the 4-week end point. Logistic regression analyses of the combined effects of treatment and prognostic factors showed no significant differences between placebo- and antibiotic-treated groups for unilateral effusions and for bilateral effusions. When subjects with unilateral and bilateral effusions were combined, the estimated efficacy of antibiotic treatment was 12.3% by otoscopy (P =.014) and 4.8% by tympanometry (P =.171). We also demonstrate the sensitivity of outcome to diagnostic measures used and provide statistical evidence questioning the validity of otoscopic observations in this study. Six weeks after the termination of amoxicillin therapy, the recurrence of effusion was two to six times higher in the amoxicillin-treated children than in those treated with placebo (P=.001), and resolution of effusion was not significantly different among antibiotic and placebo groups (13.6% and 11.3%, respectively; P=.477). Conclusions. —Amoxicillin with and without decongestant-antihistamine combination is not effective for the treatment of persistent asymptomatic middle-ear effusions in infants and children

    Identification of the mandibular landmarks in a pediatric population

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    Objectives: The aim of this study was to determine and compare the reliability to accomplish of common man - dibular landmarks and to determine the incidence of incisive canals, anterior looping, and lingual foramina in children from panoramic and CBCT images. Study Design: Panoramic and CBCT images from 100 children and adolescent patients were randomly selected. In order to grade the visibility of mandibular anatomical landmarks, a four-point rating scale was used. Results: In panoramic images, the mandibular canal could be observed in 92.5% of cases, with good visibility in 12.0%. The mental foramen could be observed in 44.5% of cases, while none had good visibility. Anterior looping of the mental nerve was present in 16.5% of the cases, and none had good visibility. An incisive canal could be identified in 22.5% of cases, with only 1.5% showing good visibility. The lingual foramen could be visualized in 61.0% of cases, with good visibility in 6%. In CBCT images, the mandibular canal, the mental foramen, and the lingual foramen could be observed in 100% of the cases, with good visibility in 51.0%, 98.5%, and 45.0% of cases, respectively. Anterior looping of the mental nerve was present in 26% of cases, with 2% having good visibility. An incisive canal could be identified in 49.5% of cases, with only 75% showing good visibility. Conclusions: This study confirms the applicability of CBCT images to visualize critical structures in children

    Consequences of cooperativity in supramolecular polymers

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    N,N',N"-Trialkylbenzene-1,3,5-tricarboxamides (BTAs) self-assemble by means of strong, threefold intermolecular hydrogen bonding into well-defined, helical, one-dimensional columnar aggregates.1 When a stereogenic centre is introduced into the alkyl side chains of these BTA molecules, strong Cotton effects are observed in dilute apolar solutions, indicating the preference for one helical conformation over the other.2 A helical sense preference can also be created by the introduction of isotope chirality into the a-position of the alkyl side chains in BTA molecules. Quantitative analysis on the observed process in dodecane demonstrates that a stereoselectively deuterated BTA forms right- (P) and left-handed (M) helical supramolecular polymers with a slight difference in stability upon cooling and the diastereomeric excess (d.e. = ([M]-[P])/([M]+[P])) is 38% at room temperature3. The subtle character of these deuterated-BTA-based supramolecular polymers makes it a highly sensitive probe to investigate the effect of the molecular structure of the alkane solvent in the self-assembly processes4. Furthermore, the effect of adding a racemization reaction into a self-assembly process by using a BTA molecule with a labile stereocenter was investigated. Racemization reaction in a self-assembling BTA system follows nonfirst-order reaction kinetics. Enantioenriched BTA molecules are obtained from a racemizing solution in the presence of a sergeant molecule which is unreactive towards base. The results are further analyzed by using a theoretical model which is capable of precise quantitative description of the experimental data obtained. The calculations are fully confirmed by experimental data with even the smallest details being fully explained by the methodology employed4. This dissertation focuses on the self-assembly process of BTA molecules and investigates the effect of isotope substitution, alkane solvent employed for self-assembly process and the introduction of racemization reaction into the self-assembly process. 1. A. R. A. Palmans, E. W. Meijer, Angew. Chem. Int. Ed. 2007, 46, 8948. 2. P. J. M. Stals, M. M. J. Smulders, R. Martin-Rapùn, A. R. A. Palmans, E. W. Meijer, Chem. Eur. J. 2009, 15, 2071. 3. S. Cantekin, D. W. R. Balkenende, M. M. J. Smulders, A. R. A. Palmans, E. W. Meijer, Nat. Chem. 2011, 3, 42. 4. S. Cantekin, Y. Nakano, J. C. Everts, P. van der Schoot, E. W. Meijer, A. R. A. Palmans, Chem. Commun. 2012, 48, 3803. 5. S. Cantekin, H. M. M. ten Eikelder, A. J. Markvoort, M. A. J. Veld, P. A. Korevaar, M. M. Green, A. R. A. Palmans and E. W. Meijer, Angew. Chem. Int. Ed. 2012 DOI 10.1002/anie.201201701

    Morphological variability and age structure in a population of Bufo verrucosissimus (Anura: Bufonidae) from Artvin, Turkey

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    Morphological variability and age structure in a population of Bufo verrucosissimus (Anura: Bufonidae) from Artvin, Turkey. We investigated morphological diversity (external body traits, coloration patterns and skin structure) and age structure in a population of Caucasian toad (Bufo verrucosissimus) from Lake Bor??ka Karag??l, situated in the vicinity of Artvin on the northeastern border of Turkey and Georgia. Age was determined using phalangeal skeletochronology. The external morphological variability was assessed using the linear measurement of 27 body-related characters and the photographs of each specimen. According to the results, the means of head length and head width were found significantly lower in-arag??l population as opposed to Caucasian populations, but average body size did not differ among all populations. Coloration and pattern features of the specimens from Karag??l were identical to those of Caucasia. Most of the females have brown tones and males are usually olive green and brown. The indiscrete elongated dark bands on parotoids did not extend behind the gland. 2C# analysis confirmed a clear separation between the sexes and a high degree of female-biased sexual size dimorphism was determined based on the body size (SDI index: +0.41). The constructed Von Bertalanffy growth curve models yielded similar profiles in both sexes. Body size and age were significantly correlated in both models, but growth coefficient value was higher in males. Accordingly, the mean age of the Karag??l population is greater in both sexes, but the lifespan and maximum age are greater in Caucasus populations

    Age estimation and body size of the Parsley Frog, Pelodytes caucasicus Boulenger, 1896 from Lake Borçka Karagöl, Turkey

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    In this study, we described age structure, body size, body mass and the relationships among these parameters for a population of P. caucasicus from Lake Borçka Karagöl, Artvin, Turkey. The mean SVL with standard error was 45.87 mm ± 0.55 (range: 39.98-50.28 mm) and the mean weight with standard error 8.81 g ± 0.39 (range: 6.10-11.47 g) in females whereas 48.16 mm ± 0.45 (range: 43.64-54.78 mm) and 11.32 ± 0.25 (range: 9.56-14.80 g) in males, respectively. We found a significant male-biased difference reflecting sexual dimorphism and statisti-cally significant positive relationships between these variables. According to the results, the age ranged between 2-5 years in females and 2-6 years in males. The mean age distributions significantly differed between the sexes (females: 3.28 years ± 0.19; males: 3.94 years ± 0.20). The mean ages and maximal ages were found identical to the previously reported results from Turkey, but the mean ages were higher than in Georgian populations. Von Bertalanffy growth models demonstrated similar curves, and the growth rate was faster up to 3 years in both sexes. To conclude, this study was the first to determine age structure and growth patterns in Borçka Karagöl population and weight data for P. caucasicus was presented for the first time in the literature

    Influence of Metal, Ligand and Solvent on Supramolecular Polymerizations with Transition-Metal Compounds: A Theoretical Study

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    The nature of intermolecular interactions governing supramolecular polymerizations is very important to control their cooperativity. In order to address this problem, supramolecular columns made of Pt(II) and Pd(II) complexes of oligo(phenyleneethynylene)-based pyridine (OPE) and tetrazolyl-pyridine ligands (TEP) were investigated through the dispersion-corrected PM6 method. Aromatic, CH-π, M-Cl and metallophilic interactions helped stabilize the supramolecules studied, and their geometries and associated cooperativities were in excellent agreement with experimental data. The OPE ligand and/or the presence of Pt(II) have led to stronger metallophilic interactions and also to cooperative supramolecular polymerizations, which clearly suggests that metallophilic interactions are a key factor to control cooperativity. The results indicate that sequential monomer addition is in general less spontaneous than the combination of two larger pre-formed stacks. The present theoretical investigations contribute to the further understanding of the relation between the thermodynamics of supramolecular polymerizations and the nature of different synthons

    Change in children's oral health-related quality of life following dental treatment under general anaesthesia for the management of dental caries: a systematic review.

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    BACKGROUND: Dental caries has significant impact on children and their families and may necessitate treatment under general anaesthesia (GA). The use of oral health-related quality-of-life (OHRQoL) measures enables evaluation of dental treatment from a patient's perspective. OBJECTIVE: This systematic review aimed to assess change in OHRQoL in children following treatment under GA for the management of dental caries. METHODS: A comprehensive search was conducted to identify articles which were assessed against inclusion criteria before data extraction. Studies involving children under 16 years, having treatment for dental caries under GA, were considered eligible. Included studies were quality assessed. RESULTS: Twenty studies were included, which demonstrated significant heterogeneity. Most studies employed a pre-test-post-test design. All but one study relied on proxy reports of OHRQoL. Only half the studies used instruments validated in the study population. Whereas all studies reported improved OHRQoL overall, some subscales showed changes which were not significant or worsened OHRQoL. The scientific quality of the studies varied considerably. CONCLUSION: Heterogeneity of included papers limited the conclusions which could be drawn. Treatment under GA appears to result in overall improvements in proxy-reported OHRQoL; however, there is a need for further high-quality studies employing validated, child-reported measures of OHRQoL

    Dünya savaşlarının biçimlendirdiği modern heykel sanatı

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    Tez (yüksek lisans) - Anadolu ÜniversitesiAnadolu Üniversitesi, Güzel Sanatlar Enstitüsü, Heykel Anasanat DalıKayıt no: 382232İnsanoğlu, sanatı içinde bulunduğu koşullar ve dönem dahilinde, kendini ifade etme aracı olarak kullanmış ve bir çok farklı dil geliştirmiştir. Heykel Sanatı da ilk çağlardan beri var olan bir sanat dalı olarak, değişen insan ile birlikte farklı ifade biçimleri kazanmıştır. Aydınlanma Çağı, Fransız Devrimi ve Sanayi Devrimi ile sosyal ve politik alanlardaki değişim, I. ve II. Dünya Savaşları'nın çıkış nedenlerini oluşturmuştur. Dünya Savaşları süresince ve sonrasında sanatçı, maruz kaldığı ve tanık olduğu olaylar karşısında geliştirdiği sanat dili aracılığıyla kişisel tavrını göstermiştir. II. Dünya Savaşı sonrası değişen güç dengeleri, savaşın sonucunda Amerika'yı sanat merkezi haline getirmiş, New York Paris'in yerini almıştır. Amerikan Soyut Dışavurumculuğunda; bir başka değişle New York Okulu gelişiminde, göç etmiş Avrupalı sanatçıların etkisi büyüktür. Bu araştırma kapsamında, Antik çağdan başlayarak heykel sanatının kronolojik gelişimi; dönemin felsefi, politik ve kültürel değişimleriyle birlikte irdelenmiş, Soyut Dışavurumculuk, New York Okulu sanatçıları ve savaş sonrası heykel örnekleriyle incelenmiştir

    Age structure, body size, and sexual dimorphism in a high-altitude population of pelophylax ridibundus (Pallas, 1771)

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    This study aimed to describe the morphological characteristics and age structure of a P. ridibundus population sampled from a high altitude. For this purpose, a total of 54 adult frogs (33 males and 21 females) were collected from Şavşat district, Artvin province, Türkiye. The samples were aged based on skeletochronology method. Furthermore, von Bertalanffy growth curve models were constructed using SVL and weight data. To assess sexual size and shape dimorphism, the measurements of 23 different morphological characters were analyzed using univariate and multivariate statistical techniques. The mean SVL and weight were found to be 78.05 mm and 60.87 g for males and 93.95 mm and 109.61 g for females. The mean age was 3.67 years and 4.05 years for males and females, respectively. The maximum age was found to be 6 years for both sexes. Growth curve models revealed a significant relationship between age, SVL, and weight. A clear female-biased sexual size dimorphism was found in all morphological characters. However, SVL-adjusted values indicated that males had larger head and limb structures resulting from evolutional and sexual pressures associated with reproduction and male–male competition. The shape dimorphism was found only in forelimbs, and it was male-biased and was related to clasping in amplexus
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