698 research outputs found

    Comprehensive Comparison of Trace Metal Concentrations in Inhaled Air Samples

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    Comparison of red blood profiles and oxygen transport capacity of elite and sub-elite wrestlers

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    This study aimed to compare the red blood profiles’ that are determinants of oxygen transports system, of elite wrestlers with sub-elite wrestlers. This study consists of a twenty-one elite wrestlers representing national team of Turkey who volunteered to participate in the study. Biochemical parameters were determined during transition period and the bloods were drawn in a resting state for each participant. A paired T tests was used to check the variations in hematological parameters. There are no significant differences between the groups except age. Elite wrestlers age was found to be significantly higher than sub elite wrestlers (p = 0.019 <0.005).  RBC, HGB, HCT, MCH, MCHC were within normal limits and also for athletes indicates a positive development and there were no significant differences between the groups. Training increases total hemoglobin mass by stimulating erythropoiesis, which increases the amount of O2 that can be carried by blood. regular screening of hematological variables is desirable as many athletes have values near or below the lower limit of the normal range

    Pazarlama Yönetiminde Kullanımı Açısından Toç Modelinin İçerik Analiziyle İncelenmesi

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    The purpose of the study is to investigatehow the Technology-Organization-Environment(TOE) framework is usedin social sciences and to discuss how it can be used especially in the field of marketingmanagement. Within the scope of the research,literature review is conducted and relevant studies are selected.Content analysis is applied to selectedstudies. The literature review isconducted without any timelimitation and only articles in social sciences areselected as restrictions. According to limited available resources, 33 studies deemed appropriate within the scope. The studies areevaluated and grouped according to; subjects, the sub-variables of the main context of the TOE model, sample, data collection, analysis method and research method.Results showed that, TOE framework ismostly used in social media and e-business adoption. When sub-contexts of the modelare analyzed, the most used variables are; relative advantage and compatibility in the technological context,firm size and top management support in organizational context, competitive pressure in environmentalcontext.Çalışmanın amacı, sosyal bilimlerde Teknoloji-Organizasyon-Çevre (TOÇ) modelinin nasıl kullanıldığını incelemekve özellikle pazarlama yönetimi alanında nasıl kullanılabileceğini tartışmaktır. Araştırma kapsamında literatür taraması yapılmış ve amaca yönelik olarak bazı çalışmalar tespit edilmiştir.Ulaşılan çalışmalar içerik analizi ile incelenmiştir. Araştırma kapsamında yıl sınırlaması olmadan veri tabanları üzerinden literatür taraması yapılmış, kısıt olarak sadece sosyal bilimler alanında yer alan makaleler seçilmiştir. Ulaşılabilenkaynaklar incelendiğinde içerik analizi kapsamında uygun bulunan 33 çalışmaya yer verilmiştir. Elde edilen çalışmalar;konular, TOÇ modeli ana bağlamlarının alt değişkenleri, örneklem, örneklem toplama yöntemleri, analiz yöntemi ve araştırma yöntemi açısından değerlendirilip gruplandırılmıştır.Analiz sonuçları, TOÇ modelininen çok sosyal medyanın ve e-ticaretin benimsenmesinde kullanıldığını göstermiştir. Modelalt bağlamları açısından incelendiğinde, araştırmacılar tarafından en çok kullanılan değişkenler; teknolojik bağlamda göreceli üstünlük ve uyumluluk; organizasyonel bağlamda firma büyüklüğü ve üst yönetim desteği, çevresel bağlamda rekabet baskısı olmuştur

    Foreign Post Incident in European Journals: The Approach of the Universal Postal Union and Analysis of News Content on the Ottoman Postal Administration

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    Yabancı posta meselesi, çok yönlü bir olgu olarak 20. yüzyılın başlarına kadar dünya genelinde büyük yankı uyandırmıştır. Avrupalı devletlerin yayılmacı politikalarının önemli bir bileşeni ve neticesi olan yabancı postaneler, Osmanlı Devleti’ni de derinden etkilemiştir. Batılı posta idareleri uzun yıllar müddetince Osmanlı yerleşimlerinde faaliyet göstermiştir. Osmanlı Devleti, Batılı postaların kendi aralarında rekabette bulunduğu ülke olarak da ön plana çıkmıştır. Ticari ve sosyal bir zeminde faaliyet zemini bulmuş yabancı postaneler zaman içerisinde siyasi bir boyut kazanmıştır. Batılı tarzda teşkilatlanmaya ilk kez 1840 tarihinde giden Osmanlı Devleti, kendi topraklarındaki posta varlığını ve birikimini kurumsal bir temele oturtarak yerli posta yetkinliğine yoğunlaşmıştır. Bu girişim, Avrupalı posta idareleri nezdinde kabul görmemiştir. 1860 sonrasında yoğunluk ve süreklilik kazanmış kapatma girişimlerinin geçerli bir temele dayanmadığı öne sürülmüştür, zira onlara göre Osmanlı Posta Teşkilatı uluslararası posta hizmeti sağlayabilecek yapısal dönüşümü henüz tam anlamıyla tesis edememişti. Osmanlı pazarındaki faaliyetlerini sonlandırma noktasında koşul öne süren Avrupalı devletlerin operasyonel yetkinliğe işaret etmesi sonrasında içerideki ve dışarıdaki temaslarını arttıran Osmanlı Devleti, Bern’de 22 devletin iştirakiyle düzenlenen ilk uluslararası posta kongresinde yer almıştır. Kongre bitiminde, 9 Ekim 1874’te imzalanan Evrensel Posta Sözleşmesi’yle kurulan Evrensel Posta Birliği’nin kurucu üyesi olarak iki yıl gibi kısa süre içerisinde uluslararası posta hizmeti icra edebilir hâle gelmiştir. Avrupalı devletlerin eksikliğini koz olarak kullandıkları en kritik koşulu da yerine getiren Osmanlı Devleti, buna rağmen kesin çözüm elde edememiştir. Bu süreç zarfında Avrupa basınında siyasi, ekonomik ve sosyal açılardan ele alınma lüzumu bulunan posta haberleri üretilmiştir. Bu içerikler, henüz kapsamlı ve bir bütün olarak akademik bir çalışmanın konusu olabilmiş değildir. Gazeteler haricinde yabancı literatürde Osmanlı Devleti’ni posta bağlamında hedef alan içeriklere ilişkin bir karşı yaklaşım da şekillenmemiştir. Bu makale hem bu bağlamdaki açığa temas ederek hem de yabancı gazetelerdeki içeriklerin posta perspektifinden ele alınıp alınmadığını irdeleyerek literatürdeki eksikliğe dikkat çekmeyi amaçlamaktadır.As a multifaceted fact the foreign post incident had a great repercussion throughout the world until the early parts of the 20th century. Foreign post offices, an integral component and consequence of the expansionist policies of European states, had a significant impact on the Ottoman Empire. Western postal administrations conducted operations within Ottoman settlements for an extended period. The Ottoman Empire also came to the fore as a country where European postal administrations competed among themselves. Foreign post offices, initially established on the basis of commercial and social considerations, eventually gained a political dimension. The Ottoman Empire, which adopted a Western-style postal system in 1840, prioritized the development of its domestic postal infrastructure as a matter of institutional policy. However, this initiative was met with resistance from European postal administrations who sought to maintain their presence within Ottoman territory. Despite objections to the perceived lack of structural transformation and operational competence within the Ottoman Postal Administration, the Empire’s participation in the inaugural international postal congress in Bern in 1874 marked a significant turning point. Becoming a founding member of the Universal Post al Union enabled the Ottoman Empire to provide international postal services within two years, fulfilling a critical requirement for membership that had been leveraged by European States. Nonetheless, this did not resolve all of the Empire’s issues related to foreign postal services, which continued to be a source of political, economic, and social contention. Although the European press extensively covered this topic, a comprehensive academic study has yet to be undertaken. In addition, little attention has been given in foreign literature to alternative perspectives on the issue of foreign postal services in the Ottoman Empire. This article aims to point out the gap in the literature by examining the foreign press’s coverage of the Ottoman Empire’s postal system and exploring alternative approaches to this topic

    Zero-Shot Self-Supervised Learning for MRI Reconstruction

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    Deep learning (DL) has emerged as a powerful tool for accelerated MRI reconstruction, but these methods often necessitate a database of fully-sampled measurements for training. Recent self-supervised and unsupervised learning approaches enable training without fully-sampled data. However, a database of undersampled measurements may not be available in many scenarios, especially for scans involving contrast or recently developed translational acquisitions. Moreover, database-trained models may not generalize well when the unseen measurements differ in terms of sampling pattern, acceleration rate, SNR, image contrast, and anatomy. Such challenges necessitate a new methodology that can enable scan-specific DL MRI reconstruction without any external training datasets. In this work, we propose a zero-shot self-supervised learning approach to perform scan-specific accelerated MRI reconstruction to tackle these issues. The proposed approach splits available measurements for each scan into three disjoint sets. Two of these sets are used to enforce data consistency and define loss during training, while the last set is used to establish an early stopping criterion. In the presence of models pre-trained on a database with different image characteristics, we show that the proposed approach can be combined with transfer learning to further improve reconstruction quality

    Optimization of a spectrofluorimetric method based on a central composite design for the determination of potassium losartan in pharmaceutical products

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    Here, a spectrofluorimetric method for the determination of potassium losartan (PL) in pharmaceutical products is described. The effects of critical parameters, pH, acid molarity, and temperature, on the fluorescence intensity of PL were analyzed, and these parameters were optimized using a central composite design (CCD). The highest fluorescent intensity at excitation (λex) and emission (λem) wavelengths of 248 nm and 410 nm, respectively, was achieved using 0.01 M sulfurous acid (pH 2) at 21.6 °C. Under optimum conditions, the method was linear from 0.025-0.5 µg/mL, with a reasonably high correlation coefficient (0.9993). Furthermore, the method was very sensitive (LOQ, 0.006), accurate (RE, ≤7.06), and precise (%RSD, ≤6.51). After development and validation of the method, samples containing PL were analyzed with this method, and the obtained data were statistically compared with those obtained with a previously published reference method using a two one-sided equivalence test (TOST). According to the data, the results from the proposed and reference assays were equivalent.Descreve-se método espectrofluorométrico para a determinação de losartana potássica (PL) em produtos farmacêuticos. Os efeitos de parâmetros críticos (pH, molaridade ácida e temperatura) na intensidade da fluorecência foram otimizados usando o planejamento de componente central (DCC). A mais alta intensidade fluorescente com λex=248 nm e λem= 410 nm foi obtida usando ácido sulfúrico 0.01 M (pH 2) e 21.6 ºC. Nas condições ideais, a linearidade do método foi estabelecida na faixa de concentração de 0.025-0.5 µg/mL com coeficiente de correlação bastante elevado (0.9993). Além disso, o método foi muito sensível com valor de LOQ 0.006, exato (RE≤7.06) e preciso (RSD%≤6.51). Depois do desenvolvimento e validação do método, amostras de medicamentos contendo PL foram analisadas com este método e os resultados obtidos foram comparados estatisticamente com método de referência, publicado anteriormente, usando o Teste de equivalência TOST (Teste de Equivalência Unilateral). De acordo com os dados estatísticos, os resultados do ensaio de referência e do método proposto foram equivalentes

    A new approach based on image processing for detection of wear of guide-rail surface in elevator systems

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    Elevators ensure transportation of people inside buildings and increase their life quality. High-rise buildings whose number is increasingly going up today has one or more elevator cabs to provide vertical transportation. A great number of people use elevators in many buildings such as business centres, hotels, hospitals and shopping centres daily. It is highly essential for the elevators used by many people daily to operate constantly. In the event of sudden failure of elevators during operation, people inside them face with a tough situation. Also, people have difficulty during the maintenance-repair period of elevators. Elevator system has counterweight system in order to balance the weight of elevator cab. A guide-rail system has been developed to limit the movements of elevator cab and counterweights on horizontal axis. When an elevator system is operational, cab and counterweight system move reversely. The common failures in elevators are usually seen in the components such as elevator guide-rail system, ropes and motors. In this study, a system based on image processing has been developed in order to prevent wear on guide-rail surface in elevators. In the proposed method, real-time condition monitoring is performed by cameras using built-in system. The images of elevator guide-rail surface are captured via four digital cameras fixed onto elevator cab. The image-processing methods are applied on the images captured by cameras and hence the wears on the surface of guide-rails are detected. The surface of guide-rail is firstly detected in the proposed method. Then, image segmentation and mathematical morphology are applied on the image of guide-rail surface and the wears on the surface of rail are detected. The failure extent of the wear failures detected are calculated. By processing the images captured by four cameras during movement of elevator, the results for surface of guide-rails are obtained. Using these results, reporting is performed. An elevator prototype has been created in order to carry out tests for development of the proposed method. The tests have been conducted by fixing the built-in system and cameras onto this elevator prototype. It is considerably advantageous to detect the failures on elevator guide-rails through image-processing methods. Following a literature review, it is seen that the proposed method is a new approach

    A new technique in laparoscopic abdominal access (Evsen Method, Modified Veress Technique)

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    Objectives: The most important step in laparoscopic surgery is to safely establish the pneumoperitoneum, especially since approximately half of the complications occur during the initial entry into the abdomen. There is a distinct need to modify the available methods to reduce therate of adverse events in laparoscopic entry. In this study, a modified Veress technique (MVT) or Evsen method is introduced.The aim of this article was to present a modified Veress technique for establishing the pneumoperitoneum. Material and methods: The study was conducted at the Dicle University, Faculty of Medicine, Department of Obstetrics and Gynecology, from September 2016 to May 2017. A new laparoscopic entry technique was introduced and compared with the classical Veress technique. A total of 40 cases were included in the study. MVT and the classical Veress method were applied to 26 and 14 patients, respectively. Results: The pneumoperitoneum was established at the first attempt in 23 (88.5%) MVT patients and in 7 (50%) patients from the classical Veress method group. The number of insufflation attempts to establish a successful pneumoperitoneum was lower using MVT and the difference was statistically significant (p: 0.022). As far as time is concerned, a comparison between the groups revealed that the pneumoperitoneum was established in a statistically significantly shorter time using MVT (p < 0.00). Conclusions: The modified Veress technique proved to be superior to the classical Veress method for establishing the pneumoperitoneum. Using the new method, the pneumoperitoneum was established after fewer attempts and in a shorter time

    Comparison of Wiltse and classical methods in surgery of lumbar spinal stenosis and spondylolisthesis

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    Aim Minimally invasive approaches to posterior lumbar surgery are available today that can enhance patient comfort by greatly reducing tissue damage and offer better clinical results. However, such methods have not yet gained widespread popularity despite their significant advantages. This study compares the Wiltse method and the classical method of lumbar surgery based a cohort, clinical study of 57 patients. The patients all had degenerative lumbar spinal stenosis and/or spondylolisthesis and had developed multifidus muscular atrophy. Materials and methods We enrolled 57 patients admitted to our clinic between April 2012 and September 2013 with a diagnosis of degenerative lumbar spinal stenosis and/or spondylolisthesis. These were treated with the classic posterior approach (n=26) or the Wiltse method (n=31). Findings In the classical method group, the ratio of female to male patients was 20/6 and the mean age was 58.19±10.17 years. A comparison of preoperative and postoperative multifidus muscle cross-sectional measurements (average of right and left) revealed a 36.09% atrophy level in the classical method group and a 26.34% atrophy level in the Wiltse group (p<0.01). However, atrophy development was 18.82% higher in the classical method group (p<0.05) relative to the Wiltse group. Conclusion The Wiltse method is less invasive and causes less tissue damage. It reduces the change of hemorrhage and multifidus muscles and offers a shorter duration of hospitalization with less pain
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