96 research outputs found
Simplified prediction equation for ultimate stress in beams prestressed with hybrid tendons
No full textThe use of unbonded tendons is getting more widespread in post-tensioning industry; especially in rehabilitation and strengthening of existing damaged concrete members. The prediction of the stress at ultimate in unbonded tendon is important in calculating the capacity of structural members. This thesis presents a simplified prediction equation for concrete beams prestressed with hybrid (a combination of bonded and unbonded) tendons. The proposed equation is based on the Generalized Incremental Analysis (GIA) which uses the trussed-beam model developed by Ozkul et al. (2008) and Nassif et al. (2003). The main objective of this research is to develop a simple, but accurate design equation for the prediction of the stress at ultimate in unbonded tendon. Most important parameters such as loading type, effective prestress of unbonded tendon, concrete strength, area of steel reinforcement and span-to-depth ratio are taken into consideration. The equation is applicable to beams prestressed with unbonded or hybrid, FRP or steel, external or internal tendons. For the validation of the proposed simplified equation, test results available in the literature (199 beams) are collected. The results show that the proposed simplified equation exhibited very good accuracy for the calculation of stress at ultimate in unbonded tendon. The simplified equation is easy to use, accurate and applicable to any material type and combination of tendons.M.S.Includes bibliographical referencesby Gonca Una
Occurrence of and Factors Associated With the Presence of Aflatoxin M1 in Breast Milk of Mothers in Fethiye, Turkey
No full textAflatoxins comprise a group of mycotoxins that are found in the environment. Exposure to aflatoxins has been reported to cause serious health problems in humans. Since aflatoxin M-1 (AFM(1)) is secreted in breast milk, the exposure of infants to this toxin is an important concern. The aim of this study was to determine the prevalence, levels of, and factors associated with the presence of AFM(1) in breast milk of mothers in Fethiye, Turkey. Breast milk samples were taken from 100 mothers who had given birth over the period of October-November 2017. The AFM(1) content of the samples was determined via enzyme-linked immunosorbent assay. The lowest limit for milk samples in the Ridascreen (R) AFM(1) commercial test kit is 5 ng/L. Because of this, AFM(1) levels below 5 ng/L in the breast milk samples were assessed as negative. Of the breast milk samples tested, 53 were positive. The average AFM(1) amount in the positive samples was 6.36 ng/L (ppt; range 5.10-8.31 ng/L). Mothers who were housewives, lived in damp, humid houses, or ate spices or dried fruits and vegetables had significantly greater prevalence of AFM(1) in their breast milk than those who were employed, did not report dampness or mold in the home, or did not eat spices or dried fruits and vegetables. AFM(1) in breast milk could be an important risk factor for infant health. Informing the public about food safety could reduce the amount of AFM(1) being transferred into breast milk via food channels.Mug. la Sitki Kocman University Research Projects Coordination Office [17/186]The author(s) disclosed receipt of the following financial support for the research and/or authorship of this article: Mug. la Sitki Kocman University Research Projects Coordination Office, project grant number 17/186
Correction to: Determination of growth and developmental stages in hand–wrist radiographs: Can fractal analysis in combination with artificial intelligence be used? (Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie, (2024), 10.1007/s00056-023-00510-1)
No full textFollowing the publication of the original article the authors reported that the “Author Contribution” section had been published incompletely by the publisher. Below is the complete section: M. Gonca: Conceptualization, methodology, acquisition of the data, data analysis, writing original draft preparation, reviewing, and editing; M.F. Sert: Data analysis, writing original draft preparation; D.N. Gunacar: Acquisition of the data, writing, reviewing, and editing; T.E. Kose: Acquisition of the data, supervision, writing, reviewing, and editing; B. Beser: Acquisition of the data, data collection, writing, reviewing, and editing. The original article has been corrected. We apologize for the error
Implant stability outcomes after immediate and delayed revascularized free fibula flaps: a preliminary comparative study
No full textCapar, Gonca Duygu (Trakya author)Purpose: This pilot study investigated the retrospective outcomes of implants placed immediately or with a delayed protocol in revascularized free fibula flaps (FFF). Materials and Methods: Patients undergoing FFF between 2014 and 2017 were included in the study. Implants were inserted either immediately or 23.63 +/- 10.61 months after reconstructive surgery. Resonance frequency analyses were recorded at the time of implant placement (first control) and 4 months postoperatively while uncovering and screwing the gingiva formers (second control). The statistical significance level was set at P .05). Conclusion: High stability scores similar to alveolar bone could be achieved by both immediate and delayed implant placement. Bicortical implantation results in better implant stability
Porphyry-Cu Deposits of Turkey
No full textTurkey, located within the western Tethyan-Eurasian Belt contains numerous porphyry copper deposits formed by the subduction, collision and post-collisional events during the closure of NeoTethys Ocean between the latest Cretaceous and late Miocene. These porphyry systems and associated epithermal and skarn deposits are associated with the subduction and post-subduction magmatic rocks emplaced along arc-parallel belts as in eastern Pontides and arc transverse extensional terranes as in the western Anatolian province (WAP) and Southeastern Anatolian Orogenic Belt (SEAOB). The porphyry deposits are formed in magmatic-arc (Pontides, Aegean and Bitlis-Zagros subduction), post-collisional settings (Pontides, WAP, SEAOB) after continental collision (Central Anatolian Crystalline Complex), and extensional arc setting (WAP). The porphyry Cu systems begin in the Late Cretaceous at the north, and generally young southward, where paired Late Cretaceous and Eocene metallogenic episodes are present in the eastern Pontides, WAP and SEAOB. The dominance of ages between ca. 83 and 70 Ma broadly coincides with the final stages of Late Cretaceous magmatism at the Pontides and SEAOB. The available ages are indicative of epidocity and a limited period of formation for porphyry Cu systems in these belts, and comparable to the metallogenic evolution of Turkey. The Eocene porphyry systems in discontinuous belts across Turkey reflect collisional to post-collisional processes. The number of known porphyry deposits in porphyry belts is related to the level of erosion. Therefore, the magmatic belts with fewer known porphyry may indicate too shallow or too deep crustal levels for their exposure. The estimates of numbers of undiscovered deposits combined with grade and tonnage models in Monte Carlo simulation revealed a lower density of known porphyry deposits in the Pontides, WAP and SEAOB relative to well-explored provinces around the world. This suggests that undiscovered deposits are likely present in Pontides, WAP and SEAOB. © Springer Nature Switzerland AG 2019.Barrick Gold Corporation YDAG-103Y098Acknowledgements The work is part of a collaborative research project generously sponsored by Barrick Gold Corp, Teck Cominco Ltd., and Eldorado Gold-Tüprag Metal-Mining Ltd. The finan - cial and logistical support from these companies are greatly appreciated. Part of the work is also supported by TÜB İTAK via a research project (Ç YDAG-103Y098) by the f st author. MDRU contribution no.256
In-vitro investigation of the role of tridosephosphate isomerase in breast cancer
No full textKanser hücreleri oksijenin varlığından bağımsız olarak çok miktarda laktat meydana getirir. Warburg etkisi (aerobik glikoliz) olarak tanımlanan bu durum kanser araştırmalarında glikoliz ve enerji metabolizmasını oldukça önemli bir hale getirmektedir. Glikolizde anahtar bir enzim olan Triozfosfat İzomeraz (TPI)’ın kanserle ilişkisi henüz tam olarak aydınlatılmamıştır. Buna göre tez çalışmasının amacı, TPI enziminin meme kanserindeki rolünü ve ilişkili olduğu moleküler bağlantıları ortaya koymak olarak belirlendi. Bu amaçla, öncelikle insan meme kanseri hücrelerinde (MCF-7 ve MDA-MB- 231) ve insan meme epitel hücrelerinde (MCF-10A) TPI seviyeleri belirlendi. Ardından, MCF-7 ve MDA-MB-231 hücre hatlarında TPI ifadesi siRNA Lentiviral Vektör kullanılarak baskılandı, TPI baskılanan/baskılanmayan kanser hücrelerinde canlılık analizleri ve koloni oluşum yöntemleriyle hücre canlılığı, ayrıca migrasyon analizleri ile hücrelerin göç kabiliyetleri belirlendi. Western-blot metoduyla hücresel enerji sinyal yolaklarına ve epitel-mezenkimal dönüşüm (EMT) sürecine ait belirteçler incelendi. TPI baskılanması sonrası glikolitik kapasite ve toksik bir ara ürün olan metilglioksal (MG) seviyeleri değerlendirildi. Çalışmalarımızda TPI'nın meme kanseri hücrelerinde insan meme epitel hücrelerine göre daha yüksek ekspresyon seviyesine sahip olduğu görüldü. TPI baskılanan MCF-7 ve MDA-MB-231 hücrelerinde canlılık azalırken hücrelerin migrasyon yeteneklerinin azaldığı, enerji metabolizmasının düzenleyicileri olarak görev yapan mitojenle aktive edilmiş protein kinaz (MAPK), stresle aktive protein kinaz/ c-Jun N-terminal kinaz (SAPK/JNK) ve fosfatidilinositol-3-kinaz (PI3K) sinyal yollarında disregülasyon meydana geldiği ve EMT belirteçlerinin ifadesinin azaldığı görüldü. Ayrıca, TPI baskılanan hücrelerde glikoz kullanımı ve laktat üretimi azalırken MG birikiminin arttığı görüldü. Bu sonuçlar, TPI’nın meme kanserinde onkojenik aktivite gösterebileceğini ve bu enzimin hedeflenmesinin kanser enerji metabolizmasında önemli bir strateji olabileceğini işaret etmektedir.Cancer cells produce large amounts of lactate independently of the presence of oxygen. This situation, defined as the Warburg effect (aerobic glycolysis), makes glycolysis and energy metabolism very important in cancer research. The relationship between Triosephosphate Isomerase (TPI), a key enzyme in glycolysis, and cancer has not yet been fully elucidated. Accordingly, the aim of the thesis study was determined to reveal the role of the TPI enzyme in breast cancer and the molecular connections it is associated with. For this purpose, firstly TPI levels were determined in breast cancer cells (MCF-7 and MDA-MB-231) and human breast epithelial cells (MCF-10A). Then, TPI expression in MCF-7 and MDA-MB-231 cell lines was suppressed using siRNA Lentiviral Vector, cell viability was determined by viability analyses and colony formation methods in TPI suppressed/non-suppressed cancer cells, and also the migration capabilities of the cells were determined by migration analyses. Cellular energy signaling pathways and markers of epithelial-mesenchymal transformation process were examined by Western blot method. After TPI suppression, glycolytic capacity and toxic intermediate methylglyoxal (MG) levels were evaluated. In our studies, TPI was found to have higher expression levels in breast cancer cells compared to human breast epithelial cells. In TPI suppressed MCF-7 and MDA-MB-231 cells, viability was decreased, migration abilities of the cells were reduced, dysregulation occurred in mitogen-activated protein kinase (MAPK), stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) and phosphatidylinositol-3-kinase (PI3K) signaling pathways that act as regulators of energy metabolism, and expression of epithelial-mesenchymal transformation (EMT) markers was decreased. In addition, glucose utilization and lactate production were decreased in TPI suppressed cells, while MG accumulation was increased. These results indicate that TPI may exhibit oncogenic activity in breast cancer and targeting this enzyme may be an important strategy in cancer energy metabolism
ORDER PICKING SYSTEMS IN WAREHOUSE MANAGEMENT: A LITERATURE REVIEW
No full textSipariş toplama faaliyetleri, tedarik zinciri yönetiminde, hem üretim sistemleri açısından (montaj istasyonlarına alt parçaların tedarik edilmesi), hem de dağıtım işlemleri açısından (müşteri taleplerinin karşılanması) kritik rol oynamaktadır. Müşteri siparişlerindeki eğilimler, az sayıda ve yüksek miktarlarda siparişlerin çok sayıda ve düşük miktarlarda siparişlere dönüştüğünü göstermektedir. Diğer yandan, talep edilen sipariş teslim süreleri ise her geçen gün kısalmaktadır. Bu değişimler, işletmelerin piyasada rekabet edebilmeleri için etkin ve esnek bir sipariş toplama sistemi benimsemelerini gerektirmektedir. Emek yoğun bir faaliyet olan sipariş toplama, tüm lojistik operasyonlarını ve müşteriye sağlanan hizmet seviyesini büyük ölçüde etkilemektedir. Ayrıca, sipariş toplama süreci toplam depolama maliyetlerinin yarıdan fazlasını oluşturmaktadır. Bu nedenle, sipariş toplama faaliyetlerinin en etkin şekilde gerçekleştirilmesi işletmeler için büyük önem taşımaktadır. Belirli kısıtlar ve parametreler göz önünde bulundurularak sipariş toplama süresini veya mesafesini kısaltacak şekilde sipariş toplama sürecinin planlanması son yıllarda birçok çalışmaya temel oluşturmaktadır. Bu çalışmada, depo yönetiminde en uygun sipariş toplama sisteminin oluşturulmasında karar vericilere yol göstermek amacıyla, sipariş toplama sürecinin tasarımı ve kontrolünde rol oynayan önemli faktörler ayrıntılı bir şekilde incelenmektedir. Bu kapsamda, depolarda gerçekleşen ürün akış tipleri, sipariş toplama sistemlerinin sınıflandırılması, depolama alanlarına ürün atama kararları, rotalama metotları, sipariş birleştirme ve bölgeleme politikaları ele alınmıştır. Order picking activities play a critical role in supply chain management in terms of both production systems (supplying components to assembly operations) and distribution operations (meeting customer demands). Trends in customer orders reveal that customer orders are transformed from few-and-large orders to many-and-small ones. On the other hand, lead times of customer orders get consistently shorter. Because of these changes, companies need to adopt an effective and flexible order picking system in order to remain competitive in the market. Order picking, as a labor intensive activity, deeply affects both overall logistic operations and service level provided to customers. Additionally, order picking process constitutes more than half of the total warehousing cost. For these reasons, it is crucial for companies to design and perform an effective order picking process. In recent years, planning the order picking systems that minimize the travel time or the travel distance, considering the specific constraints and parameters, has become the basis for many studies. In this study, critical factors that play role in design and control of order picking process is reviewed comprehensively to aid decision makers in constituting the optimal order picking system in warehouse management. In this context, product flow types in warehouses, classification of order picking systems, storage assignments decisions, routing methods, order batching, and zoning policies are investigated
DEPO YÖNETİMİNDE SİPARİŞ TOPLAMA SİSTEMLERİ: BİR LİTERATÜR ARAŞTIRMASI
No full textSipariş toplama faaliyetleri, tedarik zinciri yönetiminde, hem üretim sistemleri açısından (montaj istasyonlarına alt parçaların tedarik edilmesi), hem de dağıtım işlemleri açısından (müşteri taleplerinin karşılanması) kritik rol oynamaktadır. Müşteri siparişlerindeki eğilimler, az sayıda ve yüksek miktarlarda siparişlerin çok sayıda ve düşük miktarlarda siparişlere dönüştüğünü göstermektedir. Diğer yandan, talep edilen sipariş teslim süreleri ise her geçen gün kısalmaktadır. Bu değişimler, işletmelerin piyasada rekabet edebilmeleri için etkin ve esnek bir sipariş toplama sistemi benimsemelerini gerektirmektedir. Emek yoğun bir faaliyet olan sipariş toplama, tüm lojistik operasyonlarını ve müşteriye sağlanan hizmet seviyesini büyük ölçüde etkilemektedir. Ayrıca, sipariş toplama süreci toplam depolama maliyetlerinin yarıdan fazlasını oluşturmaktadır. Bu nedenle, sipariş toplama faaliyetlerinin en etkin şekilde gerçekleştirilmesi işletmeler için büyük önem taşımaktadır. Belirli kısıtlar ve parametreler göz önünde bulundurularak sipariş toplama süresini veya mesafesini kısaltacak şekilde sipariş toplama sürecinin planlanması son yıllarda birçok çalışmaya temel oluşturmaktadır. Bu çalışmada, depo yönetiminde en uygun sipariş toplama sisteminin oluşturulmasında karar vericilere yol göstermek amacıyla, sipariş toplama sürecinin tasarımı ve kontrolünde rol oynayan önemli faktörler ayrıntılı bir şekilde incelenmektedir. Bu kapsamda, depolarda gerçekleşen ürün akış tipleri, sipariş toplama sistemlerinin sınıflandırılması, depolama alanlarına ürün atama kararları, rotalama metotları, sipariş birleştirme ve bölgeleme politikaları ele alınmıştır
Geochemical characterization of a Quaternary monogenetic volcano in Erciyes Volcanic Complex: Cora Maar (Central Anatolian Volcanic Province, Turkey)
No full textKuscu, Gonca Gencalioglu/0000-0001-9801-6542WOS: 000298652300011Central Anatolian Volcanic Province (CAVP) is a fine example of Neogene-Quaternary post-collisional volcanism in the Alpine-Mediterranean region. Volcanism in the Alpine-Mediterranean region comprises tholeiitic, transitional, calc-alkaline, and shoshonitic types with an "orogenic" fingerprint. Following the orogenic volcanism, subordinate, within-plate alkali basalts (sl) showing little or no orogenic signature are generally reported in the region. CAVP is mainly characterized by widespread calc-alkaline andesitic-dacitic volcanism with orogenic trace element signature, reflecting enrichment of their source regions by subduction-related fluids. Cora Maar (CM) located within the Erciyes pull-apart basin, is an example to numerous Quaternary monogenetic volcanoes of the CAVP, generally considered to be alkaline. Major and trace element geochemical and geochronological data for the CM are presented in comparison with other CAVP monogenetic volcanoes. CM scoria is basaltic andesitic, transitionalcalc-alkaline in nature, and characterized by negative Nb-Ta, Ba, P and Ti anomalies in mantle-normalized patterns. Unlike the "alkaline" basalts of the Mediterranean region, other late-stage basalts from the CAVP monogenetic volcanoes are classified as tholeiitic, transitional and mildly alkaline. They display the same negative anomalies and incompatible element ratios as CM samples. In this respect, CM is comparable to other CAVP monogenetic basalts (sl), but different from the Meditterranean intraplate alkali basalts. Several lines of evidence suggest derivation of CM and other CAVP monogenetic basalts from shallow depths within the lithospheric mantle, that is from a garnet-free source. In a wider regional context, CAVP basalts (sl) are comparable to Apuseni (Romania) and Big Pine (Western Great Basin, USA) volcanics, except the former have depleted Ba contents. This is a common feature for the CAVP volcanics and might be related to crustal contamination or source characteristics. Indeed, HFS and other incompatible element ratios suggest the role of crustal contamination in the genesis of the CAVP monogenetic basalts.Scientific and Technological Research Council of Turkey (TUBITAK-CAYDAG)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [102Y131]; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)The research was funded by the Scientific and Technological Research Council of Turkey (TUBITAK-CAYDAG), project number 102Y131. The author gratefully acknowledges partial support by TUBITAK towards presenting part of this study at the 2nd International Maar Conference in Hungary. Zoltan Pecskay of Institute of Nuclear Research (ATOMKI) of Hungarian Academy of Sciences is thanked for the K/Ar analyses. Christoph Breitkreuz, Gerhard Worner, and Karoly Nemeth provided constructive comments that helped to improve the manuscript
The Effects of Zileuton and Montelukast in Reperfusion-Induced Arrhythmias in Anesthetized Rats
No full textAbstractBackground5-Lipoxygenase is an enzyme involved in the synthesis of leukotriene eicosanoids from arachidonic acid. The therapeutic potential of zileuton, an inhibitor of 5-lipoxygenase, and montelukast, a cysteinyl leukotriene receptor antagonist, for the treatment of ischemia/reperfusion (I/R) injury of the heart has been proposed in a few studies. However, the effects of zileuton and montelukast on I/R-induced arrhythmias have not been determined.ObjectiveWe assessed the possible protective effects of zileuton and montelukast against I/R-induced arrhythmias.MethodsForty-five male Wistar albino rats were divided into 5 groups, each containing 9 rats. Group 1: control, Groups 2 and 3: rats treated with montelukast (10 and 30 mg/kg IP); and Groups 4 and 5: rats treated with zileuton (1 and 3 mg/kg IV) 15 minutes before the induction of ischemia. Ischemia and reperfusion were induced by occluding the left main coronary artery of anesthetized rats for 6 minutes followed by reopening the artery for 6 minutes.ResultsBoth doses of zileuton decreased the mean [SE] arrhythmia score (zileuton 1 mg/kg: 1.4 [0.8]; zileuton 3 mg/kg: 1.3 [0.5] vs control: 2.9 [0.3]; P < 0.05), the duration of ventricular tachycardia, and the total length of arrhythmias, but montelukast was not effective to decrease the ventricular arrhythmias during the 6 minutes of reperfusion.ConclusionsThe results indicate for the first time that zileuton exerts an antiarrhythmic effect at different doses and that montelukast is not effective against I/R-induced arrhythmias. These results indicate that zileuton may be a candidate for drug treatment of I/R-induced arrhythmias
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