1,720,955 research outputs found
MCF-7 meme kanseri hücrelerinin tespiti ve farklı günlerde alan, yarıçap ve çevre gelişimlerinin izlenmesi
No full textFen Bilimleri Enstitüsü, Elektrik-Elektronik Mühendisliği Ana Bilim DalıMeme kanseri, kadınlarda görülen kanser türleri arasında en yaygın olanıdır. Dünyada, kanserli hücrelere karşı etkili tedavi yöntemlerinin geliştirilmesi için, bu hücrelerin iyi bir şekilde analiz edilmesi gerekmektedir. Yapılan çalışmada, lab-on-a-chip ortamında kültürlenen MCF-7 adı verilen meme kanseri hücreleri üzerinde görüntü işleme teknikleri uygulanarak bu hücrelerin 3 farklı gündeki gelişimleri incelenmiştir. Çalışmada kullanılan spheroiddeki meme kanseri hücrelerinin üç boyutlu görüntüleri mini-Opto tomografi platformu adı verilen optik tabanlı bir görüntüleme cihazıyla elde edilmiştir. Üç boyutlu spheroid yapılarını içeren görüntüler işlenmeden önce ImageJ programı ile iki boyutlu katmanlara ayrılmıştır ve katmanlı görüntüler üç ana işleme tabi tutulmuştur. İlk olarak görüntüler üzerinde ön işleme adımı gerçekleştirilmiştir. Bu işlemle görüntü içerisindeki bozukluklar çeşitli filtreler yardımıyla giderilmiştir ve görüntüler segmentasyon adımına uygun hale getirilmiştir. Segmentasyon adımında ana amaç spheroid yapısı içerisindeki ana tümör kitlelerini görüntü arka planından ayırmaktır. Bunun için eşikleme işlemi, çeşitli morfolojik işlemler ve contour işlemleri uygulanarak ana tümör kitleleri ön plana çıkarılmıştır. Segmentasyondan sonraki adım ise ana tümör kitlelerinin alan, çevre ve yarıçap gibi bazı geometrik özelliklerinden sayısal verilerin elde edildiği "özellik çıkarma" adımıdır. Görüntüler üzerinde uygulanan ana işlemler sonucunda ana tümör kitlelerinin konturları otomatik olarak çizdirilmiştir ve manuel yapılan çizimlerle karşılaştırıldığında başarılı sonuçlar elde edilmiştir. Üç farklı gün için 3 boyutlu kanserli yapıların hacimsel gelişimleri incelendiğinde ana tümör kitlesi ikinci günden dördüncü güne kadar yaklaşık olarak yüzde 121.72 ve dördüncü günden altıncı güne yaklaşık yüzde 85.80 lik bir büyüme göstermiştir. Bu durum ana tümör kitlesinin sürekli bir şekilde büyüme eğiliminde olduğunu göstermektedir. Çalışmada kullanılan MCF-7 meme kanseri hücrelerinden elde edilen veriler kanser hücrelerinin hacimsel gelişimleri ve ilerleyen aşamalarda kanser türünü belirlemede kullanılacak olan sınıflandırma işlemleri için oldukça önemlidir. Yapılan tez çalışmasında görüntüler üzerinde Python programlama dili ve açık kaynak kodlu OpenCV ortamı kullanılarak kanser hücrelerinin erken tespiti ve özelliklerinin iyi bir şekilde analiz edilmesiyle uzmanlara net ve detaylı bilgiler sunmak oldukça önemlidir. Uzmanlara sunulan bu bilgiler erken teşhisle tedavinin başarısını arttırmada, gereksiz biyopsilerden kaçınmada ve uzmanların kanserli görüntüleri yorumlama süresini azaltmada hayati öneme sahiptir.Breast cancer is the most common cancer among women. In the world, these cells need to be analyzed well in order to develop effective treatment methods against cancer cells. In this study, image processing techniques were applied to breast cancer cells called MCF-7 cultured in the Lab-on-a-chip environment, and their development on 3 different days was examined. 3-dimensional images of breast cancer cells within spheroid used in the study were obtained with an optical-based imaging tool called mini-Opto tomography platform. Images containing three-dimensional spheroid structures were separated into two-dimensional layers with the ImageJ program before processing, and the images belonging to these layers were subjected to three main processes. In the first step, the pre-processing was performed on the images and with this operation, the disorders in the images were eliminated with the help of various filters and the images were adapted to the segmentation step. The main purpose of the segmentation step is to separate the main tumor masses in the spheroid structure from the image background. For this, the main tumor masses was brought to the fore by applying the thresholding, various morphological, and contour operations. The next step after the segmentation step is the "feature extraction" step that numerical data were obtained from some geometric properties of main tumor masses such as area, perimeter, and radius. As a result of the main operations applied to the images, the boundaries of the main tumor masses were drawn automatically and successful results were obtained compared to the manual drawings. When analyzed the volumetric development of 3-dimensional cancerous structures for three different days, the main tumor mass has grown approximately 121.72 percent from the second day to the fourth day and approximately 85.80 percent from the fourth day to the sixth day. These growth rates indicate that the main tumor masses used in the study tend to grow continuously. The data obtained from the MCF-7 breast cancer cells used in the study are very important for the volumetric development of cancer cells and for the classification processes that will be used in determining the type of cancer in the following stages. In the thesis study, using Python programming language and open source OpenCV library, early detection of cancer cells and a good analysis of their properties are very important in terms of providing clear and detailed information to experts. This information provided to the experts is vital in increasing the success of the treatment with early diagnosis, avoiding unnecessary biopsies, and reducing the time that the specialists interpret cancerous images
Determination of Appropriate Thresholding Method in Segmentation Stage in Detecting Breast Cancer Cells
Get PDFAs in all cancer types, the early detection of breast cancer is vital in terms of patients hold- ing on to life. Today, computer-aided image processing systems play an important role in the detection of diseases. Analyzing the imag-es with accurate image processing methods is very important for professionals to interpret the images and to devel-op the treatment methods for diseases appropriately. The images containing cancer cells (tumoroid) used in this study were obtained from the mini-Opto to- mography device that creates 3D images by reconstruction of 2D imag-es taken from different angles. It is an electronic, mechanical, and software-based device capable of 3D imaging of tumoroids up to 1 cm in diameter in size. Observing an entire tumor spheroid that has the size of several centi-meters in size in a single square image with a microscope is not possible, but with mini-Opto tomography it is possi-ble. In our study, a few layers of 3D images of the tumoroid produced by MCF-7 breast cancer cells obtained on the different days from the mini-Opto device were used. Image thresholding offers many advantages at the seg-mentation stage in order to distinguish the target objects. In this study, the determination of the most appropriate thresholding method for detecting the main tumor masses in the layered images was investigated. Moreover, the contours of the tumoroid were determined in the original images based on applying the outcomes of thresholding. While various thresholding methods have been applied on diverse images in the literature, we have applied a few thresholding methods to small tumors up to 2 mm in size. As a result of the qualitative assessment based on the results of the contour drawings on the thresholded images, the global thresholding and adaptive thresholding meth- ods gave the best results
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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