Sapanca Gölü ve derelerinde yaşayan balıkların yenebilir kısımlardaki bazı ağır metallerin ICP-OES ile tayini

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu çalışmada Sapanca gölü ve derelerinden 15 farklı türde toplamda 20 balıkta Cu, Fe ve Zn ağır elementlerinin miktarları tespit edilmiştir. Numuneler temin edildikten sonra uygun hale getirilerek ters kral suyu ile mikrodalga cihazında çözünürleştirme işlemi uygulanmıştır. Numunelerde ICP-OES ile ağır metal analizi yapılmış ve Cu, Fe ve Zn miktarları da tespit edilmiştir. Sonuçlara göre balık örneklerin de Cu konsantrasyonu 2,60-5,31 µg/g, Fe konsantrasyonu 10,25-54,36 µg/g ve Çinko konsantrasyonu 13,66-47,11 µg/g aralığında olduğu gözlemlenmiştir. Ayrıca yöntemin doğruluğunu belirlemek için aynı işlemler standart referans madde DORM-3 referans maddeye de (Fish Protein Certified Reference Material for Trace Metals) uygulanmıştır. Sonuç olarak analizi yapılan balık örneklerinin içerdikleri ağır metal miktarlarının Türk Gıda Kodeksi (TFC), Gıda ve Tarım Örgütü (FAO) ve Dünya Sağlık Örgütü (WHO) tarafından sağlanan limit değerlerin altında olduğu ve dolayısıyla tükeminin sağlık açısından bir tehdit oluşturmadığı belirlenmiştir.In this study Cu, Fe and Zn heavy metals amounts were determined over the 15 different species 20 fish in total that were collected by Sapanca Lake, Sakarya River and Western Blacksea (Karasu). After samples were provided, microwave process was applied with reverse aqua regia following the preparation. Heavy metal analysis was conducted with ICP-OES device on the samples and Cu, Fe and Zn amounts were determined. According to the results, in fish samples it was observed that the Cu concentration 2.60-5.31 µg/g, Fe concentration 10.25-54.36 µg/g and Zn concentration 13.66-47.11 µg/g. Also verification was provided with DORM-3 standard reference material (Fish Protein Certified Reference Material for Trace Materials). As the result, obtained results for the heavy metal amounts of the samples were found below the limit values of Turkish Food Codex (TFC), Food and Agriculture Organization (FAO) and World Health Organization (WHO) and by the way the consumptions did not result threaten the health

Mikrobiološka, fizikalno-kemijska i senzorska svojstva kefira proizvedenog sekundarnom fermentacijom

In this study, the microbiological, physicochemical, and sensory properties and volatile aromatic compounds of kefir produced by secondary fermentation were investigated. Cow milk samples containing 1.5 % fat were fermented with kefir grains until the pH reached certain levels (pH 5.0-5.5), and then each of them was inoculated with a different starter culture (thermophilic, probiotic, mesophilic aromatic, and yeast) for secondary fermentation. In kefir samples produced traditionally or by secondary fermentation, the pH values, carbon dioxide levels, and tyrosine and lactic acid contents increased during storage. However, the counts of lactococcus, lactobacillus, leuconostoc, and yeasts decreased. Acetaldehyde and ethanol increased during storage, but diacetyl decreased in kefir samples produced traditionally or by secondary fermentation. The butanone contents changed very little but they showed an upward trend within the storage period. Kefir samples produced by secondary fermentation found greater acceptance during sensory testing than samples produced by the traditional method. Kefir inoculated with mesophilic aromatic and yeast cultures were the most preferred by panelists.U ovom istraživanju ispitivana su mikrobiološka, fizikalno-kemijska i senzorska svojstva te sastav hlapljivih aromatskih tvari kefira proizvedenog sekundarnom fermentacijom. Uzorci kravljeg mlijeka s 1,5 % mliječne masti fermentirani su pomoću kefirnih zrnaca do postizanja odgovarajuće pH vrijednosti (5,0-5,5), nakon čega su inokulirani različitim starter kulturama (termofilna, probotička, mezofilna aromatska i kvasci) u svrhu provođenja sekundarne fermentacije. Tijekom skladištenja u svim je uzorcima kefira došlo do porasta pH vrijednosti, udjela ugljičnog dioksida, tirozina i količine mliječne kiseline. Međutim, zabilježen je pad broja živih stanica laktokoka, laktobacila, leukonostoka i kvasaca. Također, bez obzira na način proizvodnje (tradicionalno ili sekundarnom fermentacijom) u svim uzrocima je tijekom skladištenja zabilježen porast količine acetaldehida i etanola, dok je količina diacetila opadala. Sadržaj butanona vrlo se malo mijenjao, no pokazao je rastući trend tijekom razdoblja skladištenja. Prilikom provođenja senzorskog ocjenjivanja uzorci kefira proizvedeni sekundarnom fermentacijom okarakterizirani su boljom prihvatljivošću u odnosu na kefir proizveden tradicionalnom metodom. Kefir inokuliran mezofilnom aromatskom kulturom i kulturom kvasaca pokazao se najpoželjnijim prilikom senzorskog ocjenjivanja od strane panela

Modeling and fabrication of electrostatically actuated diaphragms for on-chip valving of MEMS-compatible microfluidic systems

This paper presents an analytical model to estimate the actuation potential of an electrostatic parylene-C diaphragm, processed on a glass wafer using standard microelectromechanical systems (MEMS) process technology, and integrable to polydimethylsiloxane (PDMS) based lab-on-a-chip systems to construct a normally-closed microvalve for flow manipulation. The accurate estimation of the pull-in voltage of the diaphragm is critical to preserve the feasibility of integration. Thus, we introduced an analytical model, in a good agreement with the finite element method (FEM), to extend the solution of the pull-in instability by including the effect of nonlinear stretching for multilayered circular diaphragms. We characterized the operation of fabricated diaphragms with a 300 mu m radius for the parameters, including pull-in voltage (221 V on average), opening and closing response times (in microseconds), repeatability (more than 50 times), and touch area (25.3% +/- 2.6% at pull-in potential). The experimental pull-in voltage shows close accuracy with the predicted results. Moreover, the diaphragm, sealed with a PDMS microchannel, was tested under fluid flow to prove the applicability of microfluidic integration. The hybrid fabrication method enables the realization of optically transparent and durable electrostatic microvalves for complex functioning of polymer-based microfluidic systems, as the extended analytical formulation permits accurate modeling of operation.This paper presents an analytical model to estimate the actuation potential of an electrostatic parylene-C diaphragm, processed on a glass wafer using standard microelectromechanical systems (MEMS) process technology, and integrable to polydimethylsiloxane (PDMS) based lab-on-a-chip systems to construct a normally-closed microvalve for flow manipulation. The accurate estimation of the pull-in voltage of the diaphragm is critical to preserve the feasibility of integration. Thus, we introduced an analytical model, in a good agreement with the finite element method (FEM), to extend the solution of the pull-in instability by including the effect of nonlinear stretching for multilayered circular diaphragms. We characterized the operation of fabricated diaphragms with a 300 µm radius for the parameters, including pull-in voltage (221 V on average), opening and closing response times (in microseconds), repeatability (more than 50 times), and touch area (25.3% ± 2.6% at pull-in potential). The experimental pull-in voltage shows close accuracy with the predicted results. Moreover, the diaphragm, sealed with a PDMS microchannel, was tested under fluid flow to prove the applicability of microfluidic integration. The hybrid fabrication method enables the realization of optically transparent and durable electrostatic microvalves for complex functioning of polymer-based microfluidic systems, as the extended analytical formulation permits accurate modeling of operation

Decreased ocular pulse amplitude and retinal nerve fibre layer in multiple sclerosis

This study was conducted to assess ocular pulse amplitude and retinal nerve fibre layer in patients with multiple sclerosis and their correlation with disease duration and with severity. Retinal nerve fibre layer thickness was measured by Heidelberg Retinal Tomography II (HRT-II; Heidelberg Engineering, Dossenheim, Germany) and ocular pulse amplitude was measured by dynamic contour tonometry (Ziemer Ophthalmic Systems, Port, Switzerland) in 37 multiple sclerosis patients and 72 age- and gender-matched controls. Ocular pulse amplitude was significantly reduced and retinal nerve fibre layer was significantly thinner in temporal, superotemporal, and nasal sectors in patients with multiple sclerosis regardless of having an optic neuritis attack. The retinal nerve fibre layer was thinner in eyes with a previous optic neuritis attack compared with the eyes without an attack, but the difference was not significant. Ocular pulse amplitude showed a positive correlation with visual evoked potential amplitude and a negative correlation with visual evoked potential latency. Retinal nerve fibre layer thickness showed a significant negative correlation with the disease duration but not with visually evoked potential, disease severity, nor previous optic neuritis. These findings indicate that the process of degeneration starts in the early period of the disease, as our study group is composed of early-middle-stage multiple sclerosis patients, and is independent of relapses. © Informa Healthcare USA, Inc

Süt dişleriyle ilişkili kompound odontoma: İki olgu

Çenelerde görülen odontojenik kaynaklı tümörlerin % 22’sini oluşturan odontomalar, mine, dentin ve pulpa dokusu içeren hamartamatöz lezyonlardır. Odontomalar benign odontojenik tümörler olarak sınıflandırılmaktadır. Morfolojik olarak kompleks ve kompound odontoma olarak ikiye ayrılmaktadır. Kompound odontomalar yaygın olarak maksillada keser-kanin bölgesinde gelişmektedirler ve kompleks odontomalara göre iki kat daha fazla görülürler. Genellikle asemptomatiktirler ve rutin dental radyografi esnasında teşhis edilirler. Odontomalar diş sürme bozuklukları, komşu dişlerde konjenital eksiklik, rezorpsiyon ve malpozisyon gibi durumlarla ilişkilendirilmektedir ve sıklıkla daimi dentisyonda görülürken, nadir olarak süt dentisyonda da görülebilmektedir. Bu vaka raporunda; süt dişleriyle ilişkili iki kompound odontoma vakasının sunulması amaçlanmıştır

Sıçanlarda gentamisin ile indüklenmiş oksidatif stres aracılı nefrotoksisiteye karşı krill yağının koruyucu etkisi

This study aimed to evaluate the protective effect of krill oil against nephrotoxicity caused by gentamicin. Distilled water was given orally to the control and second groups (GI) for seven days while 500 mg/kg krill oil was given to the third (GII), fourth (GIII) groups. In addition, isotonic saline was administered subcutaneously to the control and GIII groups throughout the study, while 80 mg/kg gentamicin was administered to the GI, and GII groups. Alanine aminotransferase (ALT) and gamma glutamyltransferase (GGT) peptidase, total cholesterol, urea, and creatinine levels in plasma and, malondialdehyde (MDA) and total antioxidant status (TAS) levels in both plasma and kidney tissue supernatant were evaluated. Histopathological changes in tubules and glomeruli and vascular changes were evaluated by scoring. Urea level and ALT activity were found to be significantly lower in the GII and GIII groups compared to the GI group (p<0.001; p≤0.001). As a result, it was observed that degenerative damage and glomerular changes in the tubule at the histological level mediated by oxidative stress were consistent with the increase in ALT, urea, and MDA levels. In this respect, it is suggested that krill oil can be used as a nephroprotective food supplement to contribute to treatment in cases of toxicity.Bu çalışmada, gentamisin'in neden olduğu nefrotoksisiteye karşı kril yağının koruyucu etkisinin değerlendirilmesi amaçlandı. Çalışmada yedi gün boyunca oral yolla kontrol ve ikinci grubuna (GI) distile su verilirken, üçüncü (GII) ve dördüncü (GIII) gruplarına 500mg/kg krill yağı verildi. Ayrıca çalışma boyunca subkutan yolla kontrol ve GIII gruplarına izotonik tuzlu su uygulanırken, GI ve GII gruplarına 80 mg/kg gentamisin uygulandı. Plazma alanin aminotransferaz (ALT) ve gama glutamiltransferaz (GGT), total kolesterol, üre ve kreatinin düzeylerine, hem plazma hem de böbrek doku süpernatından ise malondialdehit (MDA) ve total antioksidan kapasitesi (TAS) düzeylerine değerlendirildi. Histopatolojik olarak tubul ve glomeruluslardaki değişimler ile damarsal değişiklikler skorlanarak değerlendirildi. Üre düzeyi ve ALT aktivitesi GI gruba göre GII ve GIII verilen grupta anlamlı düzeyde düşük bulundu (p<0.001; p≤0.001). Sonuç olarak, oksidatif stres aracılı olarak histolojik düzeyde tubulde dejeneratif hasar ve glomerular değişikliklerin özellikle ALT, üre ve MDA düzeyleri artışıyla uyumlu olduğu görüldü. Bu bakımdan, krill yağı nefroprotektif bir gıda takviyesi olarak toksisite durumlarında tedaviye katkı sağlamak için kullanılabileceği önerilmektedir

Telling functional networks apart using ranked network features stability

Over the past few years, it has become standard to describe brain anatomical and functional organisation in terms of complex networks, wherein single brain regions or modules and their connections are respectively identified with network nodes and the links connecting them. Often, the goal of a given study is not that of modelling brain activity but, more basically, to discriminate between experimental conditions or populations, thus to find a way to compute differences between them. This in turn involves two important aspects: defining discriminative features and quantifying differences between them. Here we show that the ranked dynamical stability of network features, from links or nodes to higher-level network properties, discriminates well between healthy brain activity and various pathological conditions. These easily computable properties, which constitute local but topographically aspecific aspects of brain activity, greatly simplify inter-network comparisons and spare the need for network pruning. Our results are discussed in terms of microstate stability. Some implications for functional brain activity are discussed.Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)-218S314French Ministry of Foreign Affairs PHC-Bosphore ProgramEuropean Research Council (ERC)Spanish State Research Agency, through the Severo Ochoa and Maria de Maeztu Program for Centers and Units of Excellence in R

Immature event-related alpha dynamics in children compared with the young adults during inhibition shown by day-night stroop task

Introduction: Inhibitory control develops gradually from infancy to childhood and improves further during adolescence as the brain matures. Related previous studies showed the indispensable role of task-related alpha power during inhibition both in children and young adults. Nonetheless, none of the studies have been able to investigate the direct differences in brain responses between children and young adults when confronted with a stimulus that should be inhibited. Because, unlike event-related designs, task-related designs involve continuous tasks over a certain period, which precludes the possibility of making such a comparison. Accordingly, by employing event-related design, the present study first time in the literature, aimed to analyze the event-related alpha phase locking and event-related alpha synchronization/ desynchronization to differentiate the inhibitory processes in children compared to young adults. Methods: Twenty children between the ages of 6 to 7 years and 20 healthy young adult subjects between the ages of 18 to 30 years were included in the study. Day-night Stroop task was applied to all subjects during 18-channel EEG recordings. Event-related time-frequency analysis was performed with the complex Morlet Wavelet Transform for the alpha frequency band (8–13 Hz). Event related spectral perturbation (ERSP) in three different time windows (0–200 ms, 200–400 ms, 400–600 ms) and Event-related phase locking in the early time window (0–400 ms) was calculated. Results: The children had increased alpha power in early and late time windows but decreased alpha phase locking in the early time windows compared to young adults. There were also topological differences between groups; while young adults had increased alpha phase-locking in frontal and parietal electrode sites, children had increased occipital alpha power and phase locking. Discussion: The shift in event-related alpha power observed from posterior to anterior regions with age may suggest a progressive maturation of the frontal areas involved in inhibitory processes from childhood to adulthood. The results of the present study showed that children and young adults had different EEG oscillatory dynamics during inhibitory processes at alpha frequency range

Immature event-related alpha dynamics in children compared with the young adults during inhibition shown by day-night stroop task

IntroductionInhibitory control develops gradually from infancy to childhood and improves further during adolescence as the brain matures. Related previous studies showed the indispensable role of task-related alpha power during inhibition both in children and young adults. Nonetheless, none of the studies have been able to investigate the direct differences in brain responses between children and young adults when confronted with a stimulus that should be inhibited. Because, unlike event-related designs, task-related designs involve continuous tasks over a certain period, which precludes the possibility of making such a comparison. Accordingly, by employing event-related design, the present study first time in the literature, aimed to analyze the event-related alpha phase locking and event-related alpha synchronization/ desynchronization to differentiate the inhibitory processes in children compared to young adults.MethodsTwenty children between the ages of 6 to 7  years and 20 healthy young adult subjects between the ages of 18 to 30  years were included in the study. Day-night Stroop task was applied to all subjects during 18-channel EEG recordings. Event-related time-frequency analysis was performed with the complex Morlet Wavelet Transform for the alpha frequency band (8–13  Hz). Event related spectral perturbation (ERSP) in three different time windows (0–200  ms, 200–400  ms, 400–600  ms) and Event-related phase locking in the early time window (0–400  ms) was calculated.ResultsThe children had increased alpha power in early and late time windows but decreased alpha phase locking in the early time windows compared to young adults. There were also topological differences between groups; while young adults had increased alpha phase-locking in frontal and parietal electrode sites, children had increased occipital alpha power and phase locking.DiscussionThe shift in event-related alpha power observed from posterior to anterior regions with age may suggest a progressive maturation of the frontal areas involved in inhibitory processes from childhood to adulthood. The results of the present study showed that children and young adults had different EEG oscillatory dynamics during inhibitory processes at alpha frequency range