Diş Hekimliğinde Topikal Florür Uygulama Metotları

Çocuklarda ve yetişkinlerde diş çürüğünün önlenmesi modern diş hekimliği pratiğinin en önemli niteliğidir. Diş hekimleri tarafından diş çürüğünün önlenmesi amacıyla çok sayıda koruyucu diş hekimliği programı geliştirilmiş olmasına karşın muhtemelen bunlardan hiçbiri florun uygun kullanımı kadar önemli değildir. Diş hekimleri hastaların optimal flor alımını sağlamak için çeşitli seçenekleri vardır. Bu makalede, diş hekimliği pratiğinde hem profesyonel hem de bireysel uygulanan farklı topikal florür uygulama metotların derlenmesi amaçlanmıştı

İki Farklı Restoratif Materyalin Sınıf V Kavitelerdeki Mikrosızıntıya Etkisi

Amaç: Bu çalışmanın amacı sınıf V kavitelerde birkompozit rezin ile bir yüksek viskoziteli cam iyonomersimanın mikrosızıntılarının in vitro şartlardadeğerlendirilmesidir.Gereç ve Yöntem: Bu çalışmada 30 adet çürüksüz insanüst premolar dişi kullanıldı. Her dişin bukkal yüzeylerinemine-sement sınırından 1 mm aşağıda olacak şekildestandardize edilmiş Sınıf V kaviteler hazırlandı. Dişler herbiri 15 dişten oluşan rastgele 2 gruba ayrıldı. Hazırlanankaviteler birinci grupta bir kompozit rezinle (S3 Bond /Clearfil Esthetic; Kuraray, Tokyo, Japonya), ikinci grupta biryüksek viskoziteli cam ionomer (Fuji IX GP; GC, Tokyo,Japonya) ile dolduruldu. Restoratif maddeler bir LED (EliparFreelight; 3M ESPE, Seefeld, Germany) ışık kaynağıkullanılarak polimerize edildi. Bütün örnekler 24 saat distilesu içerisinde bekletildi ve 1 dakika kalacak şekilde 5 ve 55°Ctermal siklus işlemi 10000 kez uygulandı. Dişlerrestorasyonların 1 mm çevresi hariç tırnak cilası ile kaplandı.24 saat %1’lik metilen mavisi solüsyonunda bekletildi. Dahasonra dişler yıkanıp, bukkolingual yönde dikey olarakkesilerek x15 büyütmede stereomikroskop ile değerlendirildi.Elde edilen veriler Kruskal Wallis ve Whitney U testleriyledeğerlendirildi.Bulgular: Deney grupları arasında istatistiksel birfarklılık bulunamadı (p>0.05). Grup 1’de servikal ve oklüzalmikrosızıntı değerleri arasında istatistiksel olarak anlamlılıkbulundu ( p<0.05 ). Grup 2’ de ise servikal ve oklüzalskorlarda fark bulunmadı. Sonuç: Kullanılan her ikirestoratif materyal, sınıf V kavitelerde mikrosızıntıdeğerlendirmesinde başarılı bulunmuştur

Federated Learning on Heterogenous Data using Chest CT

Large data have accelerated advances in AI. While it is well known that population differences from genetics, sex, race, diet, and various environmental factors contribute significantly to disease, AI studies in medicine have largely focused on locoregional patient cohorts with less diverse data sources. Such limitation stems from barriers to large-scale data share in medicine and ethical concerns over data privacy. Federated learning (FL) is one potential pathway for AI development that enables learning across hospitals without data share. In this study, we show the results of various FL strategies on one of the largest and most diverse COVID-19 chest CT datasets: 21 participating hospitals across five continents that comprise >10,000 patients with >1 million images. We present three techniques: Fed Averaging (FedAvg), Incremental Institutional Learning (IIL), and Cyclical Incremental Institutional Learning (CIIL). We also propose an FL strategy that leverages synthetically generated data to overcome class imbalances and data size disparities across centers. We show that FL can achieve comparable performance to Centralized Data Sharing (CDS) while maintaining high performance across sites with small, underrepresented data. We investigate the strengths and weaknesses for all technical approaches on this heterogeneous dataset including the robustness to non-Independent and identically distributed (non-IID) diversity of data. We also describe the sources of data heterogeneity such as age, sex, and site locations in the context of FL and show how even among the correctly labeled populations, disparities can arise due to these biases

Deep COVID DeteCT: an international experience on COVID-19 lung detection and prognosis using chest CT

The Coronavirus disease 2019 (COVID-19) presents open questions in how we clinically diagnose and assess disease course. Recently, chest computed tomography (CT) has shown utility for COVID-19 diagnosis. In this study, we developed Deep COVID DeteCT (DCD), a deep learning convolutional neural network (CNN) that uses the entire chest CT volume to automatically predict COVID-19 (COVID+) from non-COVID-19 (COVID−) pneumonia and normal controls. We discuss training strategies and differences in performance across 13 international institutions and 8 countries. The inclusion of non-China sites in training significantly improved classification performance with area under the curve (AUCs) and accuracies above 0.8 on most test sites. Furthermore, using available follow-up scans, we investigate methods to track patient disease course and predict prognosis

Effect of cooling rate and Mg addition on the structural evaluation of rapidly solidified Al-20wt%Cu-12wt%Fe alloy

The present work examines the effect of Mg contents and cooling rate on the morphology and mechanical properties of Al20Cu12Fe quasicrystalline alloy. The microstructure of the alloys was analyzed by scanning electron microscopy and the phase composition was identified by X-ray diffractometry. The melting characteristics were studied by differential thermal analysis under an Ar atmosphere. The mechanical features of the melt-spun and conventionally solidified alloys were tested by tensile-strength test and Vickers micro-hardness test. It was found that the final microstructure of the Al20Cu12Fe samples mainly depends on the cooling rate and Mg contents, which suggests that different cooling rates and Mg contents produce different microstructures and properties. The average grain sizes of the melt spun samples were about 100-300 nm at 35 m/s. The nanosize, dispersed, different shaped quasicrystal particles possessed a remarkable effect to the mechanical characteristics of the rapidly solidified ribbons. The microhardness values of the melt spun samples were approximately 18% higher than those of the conventionally counterparts. (C) 2016 Elsevier Inc. All rights reserved

Structural and electrical properties of V-doped ZnO prepared by the solid state reaction

This paper reports the synthesis, crystal structure and electrical conductivity properties of vanadium (V)-doped zinc oxide (ZnO) powders (i.e. Zn1-2X V (X) O binary system, x = 0, 0.0025, 0.005, 0.0075 and in the range 0.01 a parts per thousand currency sign x a parts per thousand currency sign 0.15). I-phase samples, which were indexed as single phase with a hexagonal (wurtzite) structure in the V-doped ZnO binary system, were determined by X-ray diffraction (XRD). The limit solubility of V in the ZnO lattice at this temperature is 3 mol % at 950 A degrees C. The impurity phase at 950 A degrees C was determined as ZnV2O6 when compared with standart XRD data. The research focused on single I-phase ZnO samples which were synthesized at 950 A degrees C because of the limit of the solubility range is widest at this temperature. It was observed that the lattice parameters a and c decreased with V doping concentration. The electrical conductivity of the pure ZnO and single I-phase samples were studied using the four-point probe dc method at temperatures between 100 and 950 A degrees C in an air atmosphere. The electrical conductivity values of pure ZnO and 3 mol % V-doped ZnO samples at 100 A degrees C were 2.75 x 10(-6) and 7.94 x 10(-5) Omega(-1) cm(-1), and at 950 A degrees C they were 3.4 and 54.95 Omega(-1) cm(-1), respectively. In other words, the electrical conductivity increased with V doping concentration

Structural, electrical and optical properties of green synthesized ZnO nanoparticles using aqueous extract of thyme (Thymus vulgaris)

Production of nanoparticles (NPs) is an interesting research area due to the potential applications in the development of novel technologies. Especially, biologically produced nanomaterials have become an important branch of nanotechnology. In this study, two different zinc oxide (ZnO) samples were synthesised for comparison. The first one was produced using aqueous extract of thyme (Thymus vulgaris). The second sample was produced using Zn(Ac)(2)center dot 2H(2)O solution in deionised water (dH(2)O). The solutions which prepared in aqueous thyme extract and dH(2)O were named as ZnO-1, and ZnO-2, respectively. The ZnO-NPs samples were characterised by X-ray diffraction (XRD) method. The XRD patterns of the both samples were indexed on basis of a hexagonal (wurtzite). Average crystallite sizes were calculated to be 42 and 85 nm for ZnO-1 and ZnO-2 samples, respectively. Morphological properties of the ZnO-NPs samples were determined with field emission-scanning electron microscopy and the grain sizes were measured to be 50 and 100 nm for ZnO-1 and ZnO-2 samples, respectively. Electrical conductivity measurements, carried out by the four point probe technique, showed that the ZnO-1 sample had higher electrical conductivity than the ZnO-2 sample. This suggests that the ZnO-1 sample has better crystal quality with lower defects along their length. In agreement, the ZnO-1 sample showed a higher transmittance (82-93%) in the UV-Vis range than the ZnO-2 sample

Tm-doped ZnO nanorods as a TCO for PV applications

In photovoltaic (PV) devices, a transparent conducting oxide (TCO) film is used as a transparent electrode which permits sun rays to reach to the photoactive semiconducting layers and also to collect the photo-generated electrons. Due to their electrical and optical properties zinc oxide (ZnO) based thin films and nanostructures are considered as an abundant and safer option for TCOs. In this study, undoped and thulium (Tm)-doped ZnO nanorods (NRs) were produced on glass substrates via spin coating and hydrothermal methods. The ZnO samples were described by X-ray diffractometry (XRD). Morphological features of the ZnO samples were investigated with scanning electron microscopy (SEM). It is observed that the all ZnO samples have nanorod shape. The average rods diameter is between 75 and 100 nm. Also, the rods length is found to be between 0.96 and 1.62 mm. Electrical properties of the ZnO samples were performed via four probe method. The conductivity increases with measurement temperature and Tm doping. Optical spectra of the ZnO samples were measured in UV-Vis range and the band gap (E-g) is found to be 3.35 eV. (C) 2018 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved