Detection of Lung Nodules on Medical Images by the Use of Fractal Segmentation

In the present paper, a method for the detection of malignant and benign tumors on the CT scan images has been proposed. In the proposed method, firstly the area of interest in which the tumor may exist is selected on the original image and by the use of image segmentation and determination of the image’s threshold limit, the tumor’s area is specified and then edge detection filters are used for detection of the tumor’s edge. After detection of area and by calculating the fractal dimensions with less percent of errors and better resolution, the areas where contain the tumor are determined. The images used in the proposed method have been extracted from cancer imaging archive database that is made available for public. Compared to other methods, our proposed method recognizes successfully benign and malignant tumors in all cases that have been clinically approved and belong to the database

Assessing data acquisition approaches in electron tomography

Electron tomography (ET) is a technique to reveal the interior structures of organic-subcellular macro molecules- and inorganic materials from their 2D cross sectional transmission electron microscope (TEM) projections. However, restricted radiation dose due to specimen damage and blind region of angular sampling as a result of physical constraints deteriorate the quality of the resultant tomograms. Typically, electron tomograms suffer from low signal to noise ratio (SNR) and elongation artifact in the direction of electron radiation. Different studies propose methods to tackle the constraints of ET in the data acquisition stage. This thesis is a comparative study among different data acquisition models by analyzing the resultant tomogram of each method quantitatively. We implement each model with a TEM simulator and compare the tomograms by their root mean square (RMS) and resolution. Results of TEM settings indicate that 1) reducing the acceleration voltage and increasing the defocus value intensifies the contrast. 2) Diminishing the objective diaphragm size reduces the brightness of the projections. Comparing data acquisition models states that 1) cosine model of dose distribution homogenizes the SNR of sinograms and compared to the conventional methods enhances the resolution of the tomograms. 2) Employing Saxton model for angular sampling boosts the resolution and declines the elongation artifact. 3) Combination of the cosine method of dose distribution and Saxton's model promotes the resolution, RMS value and elongation artifact significantly: resolution enhanced 1.81 times compared to the constant dose and angle distribution models in Z-direction. To conclude, emphasis on the SNR and sampling frequency of highly tilted angles outperforms the conventional data acquisition approaches qualitatively and quantitatively

Automated 3D Axonal Morphometry of White Matter

Peer reviewe

DeepACSON automated segmentation of white matter in 3D electron microscopy

Tracing the entirety of ultrastructures in large three-dimensional electron microscopy (3D-EM) images of the brain tissue requires automated segmentation techniques. Current segmentation techniques use deep convolutional neural networks (DCNNs) and rely on high-contrast cellular membranes and high-resolution EM volumes. On the other hand, segmenting low-resolution, large EM volumes requires methods to account for severe membrane discontinuities inescapable. Therefore, we developed DeepACSON, which performs DCNN-based semantic segmentation and shape-decomposition-based instance segmentation. DeepACSON instance segmentation uses the tubularity of myelinated axons and decomposes under-segmented myelinated axons into their constituent axons. We applied DeepACSON to ten EM volumes of rats after sham-operation or traumatic brain injury, segmenting hundreds of thousands of long-span myelinated axons, thousands of cell nuclei, and millions of mitochondria with excellent evaluation scores. DeepACSON quantified the morphology and spatial aspects of white matter ultrastructures, capturing nanoscopic morphological alterations five months after the injury. With DeepACSON, Abdollahzadeh et al. combines existing deep learning-based methods for semantic segmentation and a novel shape decomposition technique for the instance segmentation. The pipeline is used to segment low-resolution 3D-EM datasets allowing quantification of white matter morphology in large fields-of-view.Peer reviewe

On-levothyroxine measurement of thyroglobulin is not a reliable test for the follow-up of patients at high risk for remnant/recurrent differentiated thyroid carcinoma

Wstęp: Obecnie najszerzej akceptowanym narzędziem używanym w badaniach kontrolnych u chorych ze zróżnicowanym rakiem tarczycy jest pomiar osoczowego stężenia tyreoglobuliny (Tg). Nierzadko zdarza się, iż pomiary stężenia Tg odbywają się, gdy chory jednocześnie przyjmuje preparaty hormonów tarczycowych. Celem niniejszego badania była ocena przydatności pomiaru osoczowego stężenia Tg w trakcie stosowania hormonów tarczycy w wykrywaniu choroby resztkowej/nawrotowej lub obecności przerzutów u chorych z wysokim ryzykiem wznowy zróżnicowanego raka tarczycy. Materiały i metody: Retrospektywnej analizie poddano dokumentację medyczną 26 pacjentów obciążonych dużym ryzykiem wystąpienia zróżnicowanego raka tarczycy. Porównano wartości pomiarów osoczowego stężenia Tg odpowiednio w trakcie stosowania hormonów tarczycy oraz po ich odstawieniu. U wszystkich badanych wykluczono obecność przeciwciał przeciwko Tg. Przyjmując pomiary stężenia Tg w okresie odstawienia hormonów tarczycy jako "złoty standard", przeanalizowano (ustalając czułość, specyficzność oraz dodatnią i ujemną wartoœæ predylekcyjną) wyniki oznaczeń stężenia Tg podczas przyjmowania hormonów tarczycy pod kątem diagnostyki resztkowej/nawrotowej choroby. Wyniki: Średnie osoczowe stężenie Tg w warunkach stosowania terapii supresyjnej za pomocą podawanych egzogennych hormonów tarczycy wynosiło 16,5 ng/ml, natomiast po zaprzestaniu stosowania tyroksyny - 95,0 ng/ml (wartość p = 0,001). U 6 chorych (23%) przyjmujących hormony tarczycy stężenie Tg nie potwierdzało wznowy procesu nowotworowego. Przy założeniu, że pomiary stężenia Tg w okresie odstawienia hormonalnych preparatów tarczycy stanowią "złoty standard", czułość, specyficzność dodatnia i ujemna wartość predylekcyjna wynosiły odpowiednio: 72,7%, 100%, 100% i 40%. Wnioski: Monitorowanie stężenia Tg w trakcie terapii tyroksyną nie jest wiarygodną metodą w wykrywaniu wznowy choroby u chorych na zróżnicowanego raka tarczycy.Introduction: At present the most widely accepted tool for follow-up management of differentiated thyroid cancer (DTC) patients is serum thyroglobulin (Tg) measurement. It is not uncommon for the serum Tg level to be measured while the patient is taking thyroid hormones (on-treatment Tg measurement). The purpose of the study was to evaluate the accuracy of on-treatment measurement of serum Tg in detecting remnant/recurrent or metastatic disease in high-risk DTC patients. Material and methods: We retrospectively analysed the medical records of 26 high-risk DTC patients and compared the on-treatment and off-treatment Tg levels of these patients. All patients were anti-Tg negative. Using off-treatment measurement of Tg as the gold standard, the results of on-treatment measurement of Tg in the diagnosis of remnant/recurrent disease were analysed for sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV). Results: The median serum Tg level under thyroid hormone suppressive therapy (on-treatment Tg) was 16.5 ng/ml and after withdrawal of thyroid hormone suppressive therapy (off-treatment Tg) was 95.0 ng/ml (P value = 0.001). In 6 patients (23%) the on-treatment Tg level missed the recurrence of the disease. Regarding the off-treatment Tg as the gold standard, the sensitivity, specificity, PPV and NPV of the on-treatment Tg measurement were 72.7%, 100%, 100%, and 40% respectively. Conclusion: Normal serum Tg level without TSH-stimulation (on-treatment) is not diagnostically reliable in the follow-up of DTC patients with a high probability of residual/recurrent or metastatic disease

Fuzzy Clustering Based Routing in Wireless Body Area Networks to Increase the Life of Sensor Nodes

Body area networks is one of the types of wireless area networks which has been created to optimize utilizing hospital resources and for earlier diagnosis of medical symptoms, and ultimately to reduce the cost of medical care. This network like most of the wireless networks is without infrastructure and the embedded sensor nodes in the body have limited energy. Hence, the early power completion of the wireless nodes based on the transmission of messages in the network can disrupt the entire network. In this study, a fuzzy clustering based routing is presented to overcome the mention challenge. In this method, the sensor nodes are allocated to the nearest cluster, based on their distance from the cluster head node, and exchange information with the cluster-head at the near distances, and the cluster-head node, due to its high initial energy, can transmit data to the remote server. In this study, due to the movement of the person and the position shift in the sensor nodes and the distances between the cluster-head nodes, sensor nodes belonging to the clusters are also updated and placed in their proper cluster and the transmission of sensory messages was done with its nearest cluster- head node. Simulation results show that the proposed method can be better than other existing methods in and equal condition

gACSON software for automated segmentation and morphology analyses of myelinated axons in 3D electron microscopy

Background and Objective: Advances in electron microscopy (EM) now allow three-dimensional (3D) imaging of hundreds of micrometers of tissue with nanometer-scale resolution, providing new opportunities to study the ultrastructure of the brain. In this work, we introduce a freely available Matlab-based gACSON software for visualization, segmentation, assessment, and morphology analysis of myelinated axons in 3D-EM volumes of brain tissue samples. Methods: The software is equipped with a graphical user interface (GUI). It automatically segments the intra-axonal space of myelinated axons and their corresponding myelin sheaths and allows manual segmentation, proofreading, and interactive correction of the segmented components. gACSON analyzes the morphology of myelinated axons, such as axonal diameter, axonal eccentricity, myelin thickness, or gratio. Results: We illustrate the use of the software by segmenting and analyzing myelinated axons in six 3DEM volumes of rat somatosensory cortex after sham surgery or traumatic brain injury (TBI). Our results suggest that the equivalent diameter of myelinated axons in somatosensory cortex was decreased in TBI animals five months after the injury. Conclusion: Our results indicate that gACSON is a valuable tool for visualization, segmentation, assessment, and morphology analysis of myelinated axons in 3D-EM volumes. It is freely available at https://github.com/AndreaBehan/g-ACSON under the MIT license. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )Peer reviewe

Effect of Adverse Weather Conditions on Vehicle Braking Distance of Highways

The effect of adverse weather conditions on the safety of vehicles moving on different types of roads and measuring its margin of safety have always been a major research issue of highways. Determining the exact value of friction coefficient between the wheels of the vehicle and the surface of the pavement (usually Asphalt Concrete) in different weather conditions is assumed as a major factor in design process. An appropriate method is analyzing the dynamic motion of the vehicle and its interactions with geometrical elements of road using dynamic simulation of vehicles. In this paper the effect of changes of friction coefficient caused by the weather conditions on the dynamic responses of three types of vehicles: including Sedan, Bus, and Truck based on the results of Adams/car Simulator are investigated. The studies conducted on this issue for different weather conditions suggest values ranging from 0.04 to 1.25. The results obtained from simulation based on Adams/car represent that the friction coefficient in values of 0.9, 0.8, 0.7, 0.6 do not effect on braking distance significantly and it is possible to attribute them all to dry weather condition. However, as it was anticipated the values of 0.5, 0.4, 0.28 and 0.18 have significant differences in braking distance. Hence, the values of 0.5, 0.4, 0.28 and 0.18 can be attributed to wet, rainy, snowy and icy conditions respectively

Effects of Probiotic Cells on the Mechanical and Antibacterial Properties of Sodium-Caseinate Films

Background and Objective: Food processing conditions such as heat, mechanical or osmotic stress can lead to considerable losses of probiotics’ survival in food. Recently, the addition of probiotics into edible films has been proposed as an emerging technology for the delivery of probiotic cells. In this study, Lactobacillus acidophilus and Lactobacillus casei cells were incorporated into sodium caseinate matrix to develop a probiotic-based film which can improve food safety.Material and Methods: Probiotic cells were separately added to the film forming solutions and the active films were prepared by casting method. The physical, optical and mechanical characteristics of the films were examined. Color properties were determined using a colorimeter and the mechanical properties of the films were evaluated by an Instron Universal Testing Machine. The viability of Lactobacillus acidophilus and Lactobacillus casei in the films was determined during a period of 12 days. The antibacterial activities of the films were also tested against Listeria monocytogenes on Trypticase Soy Agar medium at 4°C.Results and Conclusion: Results demonstrated that lactic acid bacteria cells remained viable during a storage period of 12 days (> 4 Log CFU cm-2). The incorporation of lactic acid bacteria cells into the film polymer had no significant effect on tensile strength (p>0.05) whereas it significantly improves the appearance of films. Indeed, samples covered with the lactic acid bacteria film displayed higher anti-listerial activity than the control group on day 6 of preservation (p≤0.05). These findings show that the sodium caseinate film containing lactic acid bacteria cells can be used as a new effective packaging method for improving food safety