National Repository of Grey Literature 3 records found  Search took 0.00 seconds. 
Cell segmentation from wide-field light microscopy images using CNNs
GHAZNAVI, Ali
Image object segmentation allows localising the region of interest in the image (ROI) and separating the foreground from the background. Cell detection and segmentation are the primary and critical steps in microscopy image analysis. Analysing microscopy images allows us to extract vital information about the cells, including their morphology, size, and life cycle. On the other hand, living cell segmentation is challenging due to the complexity of these datasets. This research focused on developing Artificial Intelligence/Machine Learning methods of single- and multi-class segmentation of living cells. For this study, the Negroid cervical epithelioid carcinoma HeLa line was chosen as the oldest, immortal, and most widely used model cell line. Several time-lapse image series of living HeLa cells were captured using a high-resolved wide-field transmitted/reflected light microscope (custom-made for the Institute of Complex System, Nové Hrady, Czech Republic) to observe micro-objects and cells. Employing a telecentric objective with a high-resolution camera with a large sensor size allows us to achieve a high level of detail and sharper borders in large microscopy images. The collected time-lapse images were calibrated and denoised in the pre-processing step. The data sets collected under the transmission microscope setup were analyzed using a simple U-Net, Attention U-Net, and Residual Attention U-Net to achieve the best single-class semantic segmentation result. The data sets collected under the reflection microscope setup were analyzed using hybrid U-Net methods, including Vgg19-Unet, Inception-Unet, and ResNet34-Unet, to achieve the most precise multi-class segmentation result.
Interakce acetabulární komponenty a pánevní kosti s vadou v cementové vrstvě
Vyčichl, Jan ; Jiroušek, Ondřej ; Jírová, Jitka
The article deals with contact stress analysis of pelvic bone after implantation of cemented acetabular component with imperfections of cemented layer. 3D high resolution FE model of pelvic bone was created from the sequence of CT--slices. Imperfections were created both in the cement layer and in the bone tissue by drilling fixation holes. Boolean operations were used for inserting the spherical cemented component. Two contacts were defined in the FE model. The first contact is defined between the cement layer and the pelvic bone and the second one is between the cement layer and the polyethylene cup. The model was loaded by quasi--static joint forces, representing the maximum value of stance phase of gait (Bergmann HIP98). The FE model was used to ascertain the contact stress conditions in the underlying subchondral bone.
Interaction of pelvic bone and acetabular component
Vyčichl, Jan ; Jiroušek, Ondřej ; Jíra, J.
The article deals with development and validation of complex FE model of pelvic bone and acetabular component. The model of pelvic bone is constructed on basis of CT data of high resolution. Different designs of acetabular components are then incorporated in the FE model using Boolean operations. Comparative study of different acetabular components (spherical, conical and spherical cemented) is presented. Contact stresses in the underlying pelvic bone are compared for each of the cup designs.

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