Determination of antibiotic susceptibility and fatty acid methyl ester profiles of Bacillus cereus strains isolated from different food sources in Turkey

In this study, a total of 77 Bacillus cereus isolates were obtained from four different food samples (58 raw milks, 8 chickens, 7 cereals and 4 meats) consumed in Turkey by using Chromogenic Bacillus Cereus Agar (Oxoid, CM1036). They were tested for susceptibilities to a total of 10 different antibiotics (penicillin, oxacillin, sulphamethoxazole, rifampicin, apromycin, amikacin, tobramycin, kanamycin, gentamicin and oflaxacin). In addition, they were determined to be in fatty acid methyl esters (FAMEs) group of the strains. All the isolates were identified as B. cereus based on colonical, cellular morphology and biochemical characters, including FAME analysis. A total of 25 different fatty acids were detected in 77 strains tested, but 16 of them appeared as minor components, in less than 2%. The strains had 15:0 iso 3OH (30.25%), 16:0 iso (11.23%), 17:0 iso (9.20%),16:0 (9.02%),13:0 iso (8.85%), 14:0 iso (6.79%), 15:0 anteiso (4.83%), 14:0 (4.58%), 16:1 ω6c (3.92%) and 16:1 ω7c (3.92%) as the major fatty acids (FA). Based on FAME analysis, the isolates were clustered into three main groups. Cluster 1, 2 and 3 were composed of the 71, 3 and 3 strains, respectively. All the strains in each cluster showed an extremely high degree of similarity (95 - 100%) to each other. Antibiotic resistant profile showed that all strains were resistance to penicillin and oxacillin, but they were highly susceptible to gentamicin and oflaxacin

Online Distance Learning in Higher Education: E-learning Readiness as a Predictor of Academic Achievement

The purpose of this study was to examine the relationship between e-learning readiness and academic achievement in an online course in higher-level education. The survey method was employed when collecting the study data, and the data-collection instrument used was the E-Learning Readiness Scale. The scale comprises 33 items and six sub-dimensions, including (1) computer self-efficacy, (2) internet self-efficacy, (3) online self-efficacy, (4) self-directed learning, (5) learner control, (6) motivation toward e-learning. The study participants comprised 153 freshmen who were taking an online English as a Foreign Language course. A relational model is proposed in this study to measure the predicted levels of readiness on academic achievement in online learning. Reliability analysis, Pearson correlation, linear regression analysis, and structural equation modelling were used to analyze and model the study data. Results indicated that self-directed learning is the strongest predictor of academic achievement, while motivation toward e-learning was found to be another predictor of academic achievement. Internet/online/computer self-efficacy and learner control were not found to be among significant predictors of academic achievement. It is concluded that, especially with the spread of Covid-19 worldwide, education is currently switching from face-to-face to online learning in an immediate and unexpected way; therefore e-learning readiness has to be carefully taken into consideration within this new educational paradigm

Zelena sinteza nanočestica srebra uporabom maka turčinaka (Papaver rhoeas L.) i procjena njihovog potencijalnog antibakterijskog učinka

Due to their easy and low-cost production and enhanced properties, noble metal nanoparticles are preferred as nano-additives in most pharmaceutical compositions. For example, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) possess antiseptic and antimicrobial activity and they are generally preferred for obtaining antibacterial clothing and coatings. In the present study, we report a simple, low cost and green method for synthesizing AgNPs using aqueous extracts of common poppy (Papaver rhoeas L). Synthesised silver nanoparticles were characterised based on Field Emission Scanning Electron Microscopy equipped with energy dispersive X-ray spectroscopy, Fourier-Transform Infrared Spectroscopy, and X-ray diffraction analysis. The synthesised AgNPs were also tested for antimicrobial activity using the agar well diffusion method. Characterisation methods showed that the obtained AgNPs were spherical in shape, with a particle size ranging from 15 to 40 nm. According to the antimicrobial test results, AgNPs effectively inhibited the growth of various gram-positive and gram-negative bacteria. It was concluded that Papaver rhoeas L. extract is effective as a reducing agent for the preparation of stable and monodispersed AgNPs and obtained AgNPs could be useful in antibacterial applications in human and veterinary medicine.Zahvaljujući njihovoj jednostavnoj i jeftinoj proizvodnji i pojačanim svojstvima, nanočestice plemenitih metala preferirani su nano-aditivi u većini farmaceutskih spojeva. Na primjer, nanočestice srebra (AgNP) i nanočestice zlata (AuNP) posjeduju antiseptička i antimikrobna svojstva i općenito se preferiraju u proizvodnji antibakterijske odjeće i premaza. U ovoj studiji donosimo jednostav¬nu, jeftinu i „zelenu“ metodu sintetiziranja AgNP čestica uporabom vodenih ekstrakata maka turčinaka (Papaver rhoeas L). Sintetizirane nanočestice srebra okarakterizirane su na temelju pretražne mikroskopije emisijom elektrona primjenom polja (Field Emission Scanning Electron Microscopy) opremljene energetski disperzivnom RTG spektroskopijom, infracrvenom spektroskopijom s Fourierovom transformacijom i rendgenskom difrakcijskom analizom. Sintetizirane AgNP čestice ispitane su i na antimikrobnu aktivnost uporabom metode difuzije u agaru. Me¬tode karakterizacije pokazale su da su dobivene AgNP čestice sfernog oblika, a veličina čestica kretala se između 15 i 40 nm. Prema rezultatima antimikrobnih ispitivanja, AgNP čestice učinkovito su spriječile rast različitih gram-pozitivnih i gram-negativnih bakterija. Zaključeno je da je ekstrakt Papaver rhoeas L učinkovit kao reducens za pripremu stabilnih i monodisperziranih AgNP čestica, a dobivene AgNP čestice mogle bi biti korisne za primjene u humanoj i veterinarskoj medicini kada je potreban antibakterijski učinak

Die Graue Keramik von Aizanoi. Von der späten Eisenzeit bis zur spätantiken Zeit

Gegenstand der Untersuchung ist die Graue Keramik der in der antiken Region Phrygien gelegenen Stadt Aizanoi. Erstellt wurde ausgehend von den Grabungsfunden eine Typologie und Chronologie der grauen Keramikgattung. Indem das graue Keramikvorkommen aus verschiedene Kontexten Aizanois (Theater-Stadion-Komplex, Säulenstraße, Thermen, Tempelplateau) in die Untersuchung einbezogen wurde, konnte über die Befunde ein Datierungsrahmen für die Graue Keramik erarbeitet werden. Die keramischen Fragmente sind zwischen der späten Eisenzeit (8./7. Jh. v. Chr.) und dem 4./5. Jh. n. Chr. anzusetzen. Auf dieser Grundlage wurde in einem zweiten Schritt der Arbeit die Abhängigkeit der in Aizanoi vorkommenden Grauen Keramik mit anderen Keramikgattungen überprüft. Die Korrespondenz zwischen der roten Glanztonkeramik und der Grauen Keramik wurde ausführlich betrachtet. Das gilt auch für die Beziehung der Grauen Keramik zu weiteren Gattungen, wie z. B. der Reliefkeramik, der Keramik mit Barbotinedekor und der hellenistischen bemalten Keramik. Die Impulse der Sigillata wie auch weiterer nicht-grauer Gattungen auf die Graue Keramik wurden somit in Form und Dekor untersucht. Des Weiteren wurde die Frage nach der Funktion dieser Gattung beantwortet. Die Graue Keramik definiert sich durch ihre Qualität als Fein- oder Gebrauchskeramik, die neben Einflüssen seitens der hellenistischen Keramik und der Sigillata auch solchen durch Importe unterliegt. Daneben gibt es jedoch auch lokale Formen, die keine Vergleichbeispiele unter den übrigen Keramikgattungen in Aizanoi und anderenorts haben. Daraus ist zu folgern, dass es sich bei der Grauen Keramik um eine eigenständige Gattung handelt

Thin Film Piezoelectric on Substrate Resonators Electrical Characterization and Oscillator Circuit Design

Electronic systems require at least one reference signal to enable system synchronization. Oscillators and resonators are frequency selective devices that generate a desired reference signal for the systems. MEMS frequency selective devices offer alternative solutions for mechanically vibrating devices. MEMS are suitable for vibration applications by their rugged structure. In the present work, resonant behavior of thin film piezoelectric on substrate resonator (TPoS) is studied. Equivalent electrical circuit model parameters are extracted. It is observed that TPoS resonance characteristics are influenced by design aspects. The effects of perforated and continuous electrode designs on resonant behavior and also the change in resonance characteristics with the substrate thickness are reported. The colpitts oscillator circuit is implemented on a PC Board with a 27 MHz TPoS resonator and a 27 MHz quartz resonator. Jitter results are presented for both device.School of Electrical & Computer Engineerin

Radiological study on mandibular ramus asymmetry in young population

Background: The aim of this study was to estimate the prevalence of ramus asymmetries related to age and gender in a young population and the influence of growth spurt on ramus asymmetry. Materials and methods: The study consisted of 776 panoramic radiographs of individuals aged 9 to 21 years (335 males and 441 females). Individuals were divided into two groups with respect of linear growth spurt as age 12 in females and age 14 in males. The first group consisted of females aged between 9 and 11 and males between 9 and 13. The second group consisted of females aged between 12 and 21 and males between 14 and 21. Bilateral ramus heights on each radiograph were measured. A panoramic software programme was used to measure the ramus heights. Quantitative data was tested by Student’s t test. Qualitative data was tested by χ2 test. The intraclass correlation coefficient was calculated for the magnitude error of the measurement. Results: The mean of ramus asymmetry was found to be 2.90% ± 2.58%. Significant differences between the right and left ramus height ratios were observed (p < 0.01). There was a high prevalence (10.8%) of ramus asymmetry, which did not correlate with the age and gender of the patients. Conclusions: This study revealed a high prevalence of ramus asymmetry in 9–21- -year-old population. Within the limitations of this study, it can be concluded that ramus asymmetry should be carefully evaluated in all ages for the potential relation with temporomandibular dysfunctions and also for orthodontic anomalies

Ocular changes in primary hypothyroidism

<p>Abstract</p> <p>Background</p> <p>To determine the ocular changes related to hypothyrodism in newly diagnosed patients without orbitopathy.</p> <p>Findings</p> <p>Thirty-three patients diagnosed to have primary overt hypothyroidism were enrolled in the study. All subjects were assigned to underwent central corneal thickness (CCT), anterior chamber volume, depth and angle measurements with the Scheimpflug camera (Pentacam, Oculus) and cup to disc ratio (C/D), mean retinal thickness and mean retinal nerve fiber layer (RNFL) thickness measurements with optical coherence tomography (OCT) in addition to ophthalmological examination preceeding the replacement therapy and at the 1^st, 3^rdand 6^thmonths of treatment.</p> <p>The mean age of the patients included in the study were 40.58 ± 1.32 years. The thyroid hormone levels return to normal levels in all patients during the follow-up period, however the mean intraocular pressure (IOP) revealed no significant change. The mean CCT was 538.05 ± 3.85 μ initially and demonstrated no statistically significant change as the anterior chamber volume, depth and angle measurements did. The mean C/D ratio was 0.29 ± 0.03 and the mean retinal thickness was 255.83 ± 19.49 μ initially and the treatment did not give rise to any significant change. The mean RNFL thickness was also stable during the control visits, so no statistically significant change was encountered.</p> <p>Conclusions</p> <p>Neither hypothyroidism, nor its replacement therapy gave rise to any change of IOP, CCT, anterior chamber parameters, RNFL, retinal thickness and C/D ratio.</p

An Overview of Clinical Studies on Fiber Post Systems

Intraradicular posts are useful adjuncts in the restoration of endodontically treated teeth. These systems have undergone a significant evolution in recent years, and fiber-reinforced systems have started to be incorporated into routine clinical care more frequently. Despite the high number of laboratory studies pertaining to the characteristics of fiber posts, clinical studies evaluating their general success rates are rather limited. Since clinical investigations are reliable means to achieve information about the general behavior pattern of materials or techniques, assessment of this data will be beneficial to have a better understanding of fiber-reinforced intraradicular post systems. The purpose of this paper was to make a summary of clinical studies regarding various fiber posts. A PubMed search was conducted and articles dating back to 1990 were retrieved. The paper provides an overview of clinical studies on fiber posts specifically in the last decade as well as commentary analysis