Showing 19 results for Learning
Vafaei Aa, Rashidy-Pour A,
Volume 67, Issue 4 (7-2009)
Abstract
Background: Previous studies suggested that stressful events that release Glucocorticoid from adrenal cortex and also injection of agonists of glucocorticoids receptors probably affect emotional learning and memory process and modulate them. The aim of this study was to determine the effects of acute stress and systemic injection of Corticosterone (as agonist of glucocorticoid receptors) on acquisition (ACQ), consolidation (CONS) and retrieval (RET) of emotional memory in rat.
Methods: In this experimental study we used 180 male Wistar rats (220-250). At the first rats was training in one trial inhibitory avoidance task. On the retention test given 48 h after training, the latency to re-enter the dark compartment of the apparatus (Step-through latency, STL) and the time spent in light chamber (TLC) were recorded during 10 min test. Intraperitoneal corticosterone in doses of 0.5, 1 and 3mg/kg injected 30min before, immediately after instruction and 30min before retrieval test. Also some groups received 10min stressful stimulation by restrainer at the same time. At the end locomotor's activity was measured for all animals.
Results: The data indicated that administration of corticosterone 30min before ACQ (1mg/kg), and immediately after CONS (1, 3mg/kg) enhance and 30min before RET (1, 3mg/kg) impair emotional memory (p<0.05). Acute stress impaired emotional memory in all phases (p<0.05). Also acute stress and injection of Corticosterone have not significantly affect motor activity.
Conclusions: These findings show that Glucocorticoid receptors in activation dependently plays an important role in modulation of emotional spatial memory processes (ACQ, CONS and RET in new information) for emotional events and these effects varies in different phases.
Hoseinzadeh M, Pouraboli I, Abbasnejad M,
Volume 67, Issue 5 (8-2009)
Abstract
Background: Learning and memory are the complicated agents of central nervous
system that various regions of brain can be involved in these phenomena, especially
regions like hippocamp. Various agents like nitric oxide and morphine can influence
learning and memory. About the effects of morphine with other components there was
not clear reports so in this study the effect of co-administration of L-Arginine
(precursor of nitric oxide) and morphine in hippocampal CA3 area on spatial learning
and memory in male rats was investigated.
Methods: Male rats were deeply anaesthetized with ketamine and xylazine and cannula
were implanted bilaterally in CA3 of hippocampus by using streotaxic technique, Then
male rats were used in seven groups that received saline, L-Arginine (0/3M), L-Arginine
(3μg/rat), L-NAME (0/3M), morphine (10mg/rat), L-Arginine (3μg/rat) with morphine or
L-NAME with morphine for five days that they were trained in morris water maze to
evaluate spatial learning and memory. There was a control group too.
Results: Our results showed that L-Arginine (3μg/rat) improved spatial learning and
memory. L-NAME (inhibitor of nitric oxide) decreased spatial learning and memory in
male rats. Injection of morphine also decreased spatial learning and memory in male
rats. Co-administeration of L-NAME and morphine decreased learning more than
morphine individually in male rats.
Conclusion: We concluded that precursor of nitric oxide improved learning and
memory in male rats and inhibitor of it and morphine impaired this phenomena and coadministration
of inhibitor of nitric oxide and morphine also impaired learning in rats.
Parisa Hasanein, Siamak Shahidi,
Volume 68, Issue 1 (4-2010)
Abstract
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Background: Ascorbic
acid improves cognitive impairments in several experimental models. Diabetes
causes learning and memory deficits. In this study we hypothesized that chronic
treatment with ascorbic acid (100mg/kg, p.o) would affect on the passive avoidance
learning (PAL) and memory in control and streptozocin-induced
diabetic rats.
Methods: Diabetes was induced by a single i.p. injection of STZ (60mg/kg). The
rats were considered diabetic if plasma glucose levels exceeded 250mg/dl on three
days after STZ injection. Treatment was begun at the onset of
hyperglycemia. PAL was assessed 30 days later. Retention test was done 24 h after
training. At the end, animals were weighted and blood samples were drawn for
plasma glucose measurement.
Results: Diabetes caused impairment in acquisition and
retrieval processes of PAL and memory in rats. Ascorbic acid treatment improved
learning and memory in control rats and reversed learning and memory deficits
in diabetic rats. Ascorbic acid administration also improved the body weight
loss and hyperglycemia of diabetics. Hypoglycemic and antioxidant properties of
the vitamin may be involved in the memory improving effects of such treatment.
Conclusion: These results show that ascorbic acid administration
to rats for 30
days from onset of diabetes alleviated the negative influence of diabetes on
learning and memory. Comparing with other nootropic drugs, vitamins have fewer
side effects. Therefore, this regimen may provide a new potential alternative
for prevention of the impaired cognitive functions associated with diabetes
after confirming by clinical trials.
Barzegar M, Talaei Zavareh Sa, Salami M,
Volume 68, Issue 10 (1-2011)
Abstract
Background: Numerous evidences indicate that various environmental stresses during
pregnancy affect physiological behavior of the offspring. This experimental
study was designed to investigate the effect of noise stress during prenatal
period of rats on spatial learning and memory and plasma corticostrone level in
postnatal life.
Methods: Three groups of pregnant rats were given daily noise stress with durations of
two and/ or four hours in last week of pregnancy period. The fourth group was
left unstressed. The male offspring from the unstressed and different stressed
groups were assigned as controls and stressed groups. The animals were
introduced to a spatial task in Morris water maze 4
trials/day for five consecutive days. The probe test was performed on the 5th day of the experiment. The delay in findings and the distance passed to locate
the target platform were assessed as the spatial learning.
Results: Our results showed that prenatal exposure to noise stress for two and/ or four
hours a day, leads to impaired acquisition of spatial learning in the postnatal
animals. The plasma level of corticostrone in the two stressed groups of rats
markedly matched with their behavioral function. Prenatal exposure to 1-
hour noise stress revealed no effects on the offsprings' behavior and plasma
corticostrone level.
Conclusion: Based on our study results, it seems that applied range of stress which is
executed through the noise stress could increase the plasma corticostrone level
and could decrease spatial learning and memory of adult male offspring.
Davari S, Talaei Sa, Soltani M, Alaei H, Salami M,
Volume 70, Issue 9 (12-2012)
Abstract
Background: Diabetes mellitus affects numerous intracellular metabolic processes, which are reflected by changes in the concentration of some plasma constituents. Particularly, the disease may indirectly undermine some functions of the nervous system including learning and memory through altering oxidative stress status. On the other hand, probiotics can enhance the antioxidant capacity. This study was designed to evaluate the effects of probiotics on spatial memory, maze learning and indices of oxidative stress in diabetic rats.
Methods: In this experimental study, 40 male Wistar rats were randomly allocated to 4 groups (n=10 for each): Control (CO), Control probiotic (CP), Control diabetic (DC), and Diabetic probiotic (DP). The probiotic supplement, including Lactobacillus acidophilus, Lactobacillus fermentum, Bifidobacterium lactis (334 mg of each with a CFU of ~1010), was administered through drinking water every 12 hours for 8 weeks. Using morris water maze (MWM), spatial learning and memory were evaluated. Serum insulin and oxidative stress indices, including superoxide dismutase (SOD) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), were measured by standard laboratory kits.
Results: Oral administration of probiotics improved impairment of spatial learning (P=0.008) and consolidated memory (P=0.01) in the rats. Moreover, probiotic treatment increased serum insulin (P<0.0001) and serum superoxide dismutase activity (P=0.007) while it decreased their blood glucose (P=0.006) and 8-OHdG (P<0.0001).
Conclusion: Probiotic supplementation reversed the serum concentrations of insulin and glucose along with an increase in antioxidant capacity in diabetic rats. It also improved spatial learning and memory in the animals. Relevancy of the metabolic changes and behavioral functions need to be further studied.
Kohzad S, Bolouri B, Nikbakht F,
Volume 70, Issue 12 (3-2013)
Abstract
Background: Extremely low frequency (0-300 Hz) fields from power lines, electronic equipment and medical devices, have been reported to produce various biological effects. Global system for mobile (GSM) is most largely used in everybody's life. This system utilizes a low frequency band as well as a high frequency range of electromagnetic field. This study investigated the effects of 217 Hz electromagnetic field (the modulating signal in GSM) on spatial learning and memory in rat.
Methods: Twenty four male Wistar rat (200- 250 g) were randomly divided in to three groups as: test, sham and control. Using a Helmholtz coil system, the test group was exposed to a uniform pulsed EMF of 200 µT (micro Tesla) intensity for 4 h/day for 21 days (2 time in a day). This procedure was repeated for the sham group but with no field. All groups were trained prior to the day 21 on the 15th day for five days four trial per day in Morris Water-Maze system. Then the probe test was carried out for 60 seconds with no platform.
Results: The ANOVA test revealed that no significant differences were found between control and exposed rats in all day of learning acquisition. Also, in probe test for investigating the memory, no significant differences observed. (P≤0.05 is accepted for significant level.
Conclusion: This finding is in consistent with previous studies and indicates low frequency band of electromagnetic fields (EMF) (200 µT intensity) in cell phone may not have any effect on the learning acquisition and spatial memory in rat.
Sallahadin Feizollah , Shiva Khezri ,
Volume 73, Issue 8 (11-2015)
Abstract
Background: Multiple Sclerosis (MS) is a neurodegenerative disease of the central nervous system (CNS). The hippocampus is a vital center for learning and memory it is extremely vulnerable to neurodegenerative diseases. The male hormones could be neuroprotective for the CNS. The current study is an attempt to investigate the effect of testosterone on learning and spatial memory following the demyelination of CA1 area by the injection of ethidium bromide in the rats' hippocampus. Methods: This experimental study has been conducted on healthy rats in the faculty of science of the Urmia University from September 2013 to February 2015. For demyelination in all previously gonadectomized healthy rats, 3µl ethidium bromide was injected into the CA1 area of rats by stereotaxic surgery. In addition, the treatment groups received 1µl testosterone (6µg/µl) during a 20-day timeframe on a daily basis after demyelination by the ethidium bromide. The control groups had no drug injection. The process of the learning and spatial memory of the rats were closely monitored by the radial Maze. The demyelination and remyelination in the hippocampus were checked by the myelin-specific coloring (Luxol fast blue and Cresyl violet). Results: The histological results suggest that the testosterone is capable of minimizing the destructive impacts of ethidium bromide in the treatment group as well as enhancing the remyelination process. In the group treated by testosterone, the percentage of the pyknotic cells 20 days after demyelination induction, represented a significant reduction compared to that of ethidium bromide group (P=0.008). The behavioral studies analyses show that the amount of the food finding time in those groups received ethidium bromide was significantly longer than those of the control groups (P=0.001). Furthermore, the application of the testosterone in the treatment groups reduced the extent of demyelination while the memory impairment induced by the ethidium bromide was significantly improved (P=0.001). Conclusion: Testosterone can act as a neuroprotective factor that reduces the extent of demyelination and the number of pyknotic cells. It also may improve the learning and memory impairment induced by ethidium bromide.
Rohollah Kalhor , Asghar Mortezagholi , Fatemeh Naji, Saeed Shahsavari, Mohammad Zakaria Kiaei ,
Volume 76, Issue 12 (3-2019)
Abstract
Background: Diabetes mellitus has several complications. The Late diagnosis of diabetes in people leads to the spread of complications. Therefore, this study has been done to determine the possibility of predicting diabetes type 2 by using data mining techniques.
Methods: This is a descriptive-analytic study that was conducted as a cross-sectional study. The study population included people referring to health centers in Mohammadieh City in Qazvin Province, Iran, from April to June 2015 for screening for diabetes. The 5-step CRISP method was used to implement this study. Data were collected from March 2015 to June 2015. In this study, 1055 persons with complete information were included in the study. Of these, 159 were healthy and 896 were diabetic. A total of 11 characteristics and risk factors were examined, including the age, sex, systolic and diastolic blood pressure, family history of diabetes, BMI, height, weight, waistline, hip circumference and diagnosis. The results obtained by support vector machine (SVM), decision tree (DT) and the k-nearest neighbors algorithm (k-NN) were compared with each other. Data was analyzed using MATLAB® software, version 3.2 (Mathworks Inc., Natick, MA, USA).
Results: Data analysis showed that in all criteria, the best results were obtained by decision tree with accuracy (0.96) and precision (0.89). The k-NN methods were followed by accuracy (0.96) and precision (0.83) and support vector machine with accuracy (0.94) and precision (0.85). Also, in this study, decision tree model obtained the highest degree of class accuracy for both diabetes classes and healthy in the analysis of confusion matrix.
Conclusion: Based on the results, the decision tree represents the best results in the class of test samples which can be recommended as a model for predicting diabetes type 2 using risk factor data.
Ali Ameri ,
Volume 77, Issue 7 (10-2019)
Abstract
Background: Deep learning has revolutionized artificial intelligence and has transformed many fields. It allows processing high-dimensional data (such as signals or images) without the need for feature engineering. The aim of this research is to develop a deep learning-based system to decode motor intent from electromyogram (EMG) signals.
Methods: A myoelectric system based on convolutional neural networks (CNN) is proposed, as an alternative to conventional classification methods that depend on feature engineering. The proposed model was validated with 10 able-bodied subjects during single and combined wrist motions. Eight EMG channels were recorded using eight pairs of surface electrodes attached around the subject’s dominant forearm. The raw EMG data from windows of 167ms (200 samples) in 8 channels were arranged as 200×8 matrices. For each subject, a CNN was trained using the EMG matrices as the input and the corresponding motion classes as the target. The resulting model was tested using a 4-fold cross-validation. The performance of the proposed approach was compared to that of a standard SVM-based model that used a set of time-domain (TD) features including mean absolute value, zero crossings, slope sign changes, waveform length, and mean frequency.
Results: In spite of the proven performance and popularity of the TD features, no significant difference (P=0.19) was found between the classification accuracies of the two methods. The advantage of the proposed model is that it does not need manual extraction of features, as the CNN can automatically learn and extract required representations from the EMG data.
Conclusion: These results indicate the capacity of CNNs to learn and extract rich and complex information from biological signals. Because both amplitude and frequency of EMG increases with increasing muscle force, both temporal and spectral characteristics of EMG are needed for efficient estimation of motor intent. The TD set, also includes these types of features. The high performance of the CNN model shows its capability to learn temporal and spectral representations from raw EMG data.
Ali Ameri ,
Volume 78, Issue 3 (6-2020)
Abstract
Background: Skin cancer is one of the most common forms of cancer in the world and melanoma is the deadliest type of skin cancer. Both melanoma and melanocytic nevi begin in melanocytes (cells that produce melanin). However, melanocytic nevi are benign whereas melanoma is malignant. This work proposes a deep learning model for classification of these two lesions.
Methods: In this analytic study, the database of HAM10000 (human against machine with 10000 training images) dermoscopy images, 1000 melanocytic nevi and 1000 melanoma images were employed, where in each category 900 images were selected randomly and were designated as the training set. The remaining 100 images in each category were considered as the test set. A deep learning convolutional neural network (CNN) was deployed with AlexNet (Krizhevsky et al., 2012) as a pretrained model. The network was trained with 1800 dermoscope images and subsequently was validated with 200 test images. The proposed method removes the need for cumbersome tasks of lesion segmentation and feature extraction. Instead, the CNN can automatically learn and extract useful features from the raw images. Therefore, no image preprocessing is required. Study was conducted at Shahid Beheshti University of Medical Sciences, Tehran, Iran from January to February, 2020.
Results: The proposed model achieved an area under the receiver operating characteristic (ROC) curve of 0.98. Using a confidence score threshold of 0.5, a classification accuracy of 93%, sensitivity of 94%, and specificity of 92% was attained. The user can adjust the threshold to change the model performance according to preference. For example, if sensitivity is the main concern; i.e. false negative is to be avoided, then the threshold must be reduced to improve sensitivity at the cost of specificity. The ROC curve shows that to achieve sensitivity of 100%, specificity is decreased to 83%.
Conclusion: The results show the strength of convolutional neural networks in melanoma detection in dermoscopy images. The proposed method can be deployed to help dermatologists in identifying melanoma. It can also be implemented for self diagnosis of photographs taken from skin lesions. This may facilitate early detection of melanoma, and hence substantially reduce the mortality chance of this dangerous malignancy.
Ali Ameri,
Volume 78, Issue 4 (7-2020)
Abstract
Background: The most common types of non-melanoma skin cancer are basal cell carcinoma (BCC), and squamous cell carcinoma (SCC). AKIEC -Actinic keratoses (Solar keratoses) and intraepithelial carcinoma (Bowen’s disease)- are common non-invasive precursors of SCC, which may progress to invasive SCC, if left untreated. Due to the importance of early detection in cancer treatment, this study aimed to propose a computer-based model for identification non-melanoma malignancies.
Methods: In this analytic study, 327 AKIEC, 513 BCC, and 840 benign keratosis images from human against machine with 10000 training dermoscopy images (HAM10000) were extracted. From each of these three types, 90% of the images were designated as the training set and the remaining images were considered as the test set. A deep learning convolutional neural network (CNN) was developed for skin cancer detection by using AlexNet (Krizhevsky, et al., 2012) as a pretrained network. First, the model was trained on the training images to discriminate between benign and malignant lesions. In comparison with conventional methods, the main advantage of the proposed approach is that it does not need cumbersome and time-consuming procedures of lesion segmentation and feature extraction. This is because CNNs have the capability of learning useful features from the raw images. Once the system was trained, it was validated with test data to assess the performance. Study was carried out at Shahid Beheshti University of Medical Sciences, Tehran, Iran, in January and February, 2020.
Results: The proposed deep learning network achieved an AUC (area under the ROC curve) of 0.97. Using a confidence score threshold of 0.5, a classification accuracy of 90% was attained in the classification of images into malignant and benign lesions. Moreover, a sensitivity of 94% and specificity of 86% were obtained. It should be noted that the user can change the threshold to adjust the model performance based on preference. For example, reducing the threshold increase sensitivity while decreasing specificity.
Conclusion: The results highlight the efficacy of deep learning models in detecting non-melanoma skin cancer. This approach can be employed in computer-aided detection systems to assist dermatologists in identification of malignant lesions.
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Amir Reza Naderi Yaghouti , Ahmad Shalbaf, Arash Maghsoudi,
Volume 79, Issue 1 (4-2021)
Abstract
Background: Accurate and early detection of non-alcoholic fatty liver, which is a major cause of chronic diseases is very important and is vital to prevent the complications associated with this disease. Ultrasound of the liver is the most common and widely performed method of diagnosing fatty liver. However, due to the low quality of ultrasound images, the need for an automatic and intelligent classification method based on artificial intelligence methods to accurately detect the amount of liver fat is essential. This paper aims to develop an advanced machine learning model based on texture features to assess liver fat levels based on liver ultrasound images.
Methods: In this analytic study, which is done from April to November 2020 in Tehran, ultrasound images of 55 obese people who have undergone laparoscopic surgery have been used and the histological result of a liver biopsy has been employed as a reference for liver fat. First, 88 texture-based features were extracted from the images using the Gray-Level Co-Occurrence Matrix (GLCM) method. In the next step, using the method of minimum redundancy and maximum correlation, the top features were selected from among 88 features and applied to the classifier input. Finally, using the three classifiers of linear discriminant analysis, support vector machine and AdaBoost, the images were classified into 4 groups based on the amount of liver fat.
Results: The accuracy of the automatic liver fat prediction model from ultrasound images for AdaBoost classification was 92.72%. However, the accuracies obtained for support vector machine and linear discriminant analysis classification were 87.88% and 75.76%, respectively.
Conclusion: The proposed approach based on texture features using the GLCM and the AdaBoost classification from ultrasound images automatically detects the amount of liver fat with high accuracy and can help physicians and radiologists in the final diagnosis.
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Hasan Mohammadi Kiani , Ahmad Shalbaf, Arash Maghsoudi,
Volume 79, Issue 2 (5-2021)
Abstract
Background: Early diagnosis of patients in the early stages of Alzheimer's, known as mild cognitive impairment, is of great importance in the treatment of this disease. If a patient can be diagnosed at this stage, it is possible to treat or delay Alzheimer's disease. Resting-state functional magnetic resonance imaging (fMRI) is very common in the process of diagnosing Alzheimer's disease. In this study, we intend to separate subjects with mild cognitive impairment from healthy control based on fMRI data using brain functional connectivity and graph theory.
Methods: In this article, which was done from April to November 2020 in Tehran, after pre-processing the fMRI data, 116 brain regions were extracted using an Automated Anatomical Labeling atlas. Then, the functional connectivity matrix between the time signals of 116 brain regions was calculated using Pearson correlation and mutual information methods. Using functional connectivity calculations, the brain graph network was formed, followed by thresholding of the brain connectivity network to keep significant and strong edges while eliminating weaker edges that were likely noise. Finally, 11 global features were extracted from the graph network and after performing statistical analyses and selecting optimal features; the classification of 14 healthy individuals and 11 patients with mild cognitive impairment was performed using a support vector machine classifier.
Results: Calculations were showed that the mutual information algorithm as a functional connectivity method and five global features of the graph network, including average strength, eccentricity, local efficiency, coefficient clustering and transitivity, using the support vector machine classifier achieved the best performance with the accuracy, sensitivity and specificity of 84, 86 and 93 percent, respectively.
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Conclusion: Combining the features of brain graph and functional connectivity by the mutual information method with a machine learning approach, based on fMRI imaging analysis, is very effective in diagnosing mild cognitive impairment in the early stages of Alzheimer’s which consequently allows treating or delaying this disease.
Ali Ameri, Mahmoud Shiri, Masoumeh Gity , Mohammad Ali Akhaee,
Volume 79, Issue 5 (8-2021)
Abstract
Breast cancer is one of the most common types of cancer in women. Screening mammography is a low‑dose X‑ray examination of breasts, which is conducted to detect breast cancer at early stages when the cancerous tumor is too small to be felt as a lump. Screening mammography is conducted for women with no symptoms of breast cancer, for early detection of cancer when the cancer is most treatable and consequently greatly reduce the death rate from the breast cancer. Screening mammography should be performed every year for women age 45-54, and every two years for women age 55 and older who are in good health. A mammogram is read by a radiologist to diagnose cancer.
To assist radiologists in reading mammograms, computer-aided detection (CAD) systems have been developed which can identify suspicious lesions on mammograms. CADs can improve the accuracy and confidence level of radiologists in decision making and have been approved by FDA for clinical use. Traditional CAD systems work based on conventional machine learning (ML) and image processing algorithms. With recent advances in software and hardware resources, a great breakthrough in deep learning (DL) algorithms was followed, which revolutionized various engineering areas including medical technologies. Recently, DL models have been applied in CAD systems in mammograms and achieved outstanding performance. In contrast to conventional ML, DL algorithms eliminate the need for the tedious task of human-designed feature engineering, as they are capable of learning useful features automatically from the raw data (mammogram). One of the most common DL frameworks is the convolutional neural network (CNN). To localize lesions in a mammogram, a CNN should be applied in region‑based algorithms such as R‑CNN, Fast R‑CNN, Faster R‑CNN, and YOLO.
Proper training of a DL‑based CAD requires a large amount of annotated mammogram data, where cancerous lesions have been marked by an experienced radiologist. This highlights the importance of establishing a large, annotated mammogram dataset for the development of a reliable CAD system. This article provides a brief review of the state‑of‑the‑art techniques for DL‑based CAD in mammography. |
Zahra Papi , Iraj Abedi, Fatemeh Dalvand, Alireza Amouheidari,
Volume 80, Issue 4 (7-2022)
Abstract
Background: Glioma is the most common primary brain tumor, and early detection of tumors is important in the treatment planning for the patient. The precise segmentation of the tumor and intratumoral areas on the MRI by a radiologist is the first step in the diagnosis, which, in addition to the consuming time, can also receive different diagnoses from different physicians. The aim of this study was to provide an automated method for segmenting the tumor and intratumoral areas.
Methods: This is a fundamental-applied study that was conducted from May 2020 to September 2021 using multimodal MRI images of 285 patients with glioma tumors from the BraTS 2018 Database. This database was collected from 19 different MRI imaging centers, including multimodal MRI images of 210 HGG patients, and 75 LGG patients. In this study, a 2D U-Net architecture was designed with a patch-based method for training, which comprises an encoding path for feature extraction and a symmetrical decoding path. The training of this network was performed in three separate stages, using data from high-grade gliomas (HGG), and low-grade gliomas (LGG), and combining two groups of 210, 75, and 220 patients, respectively.
Results: The proposed model estimated the Dice Similarity Coefficient (DSC) results in HGG datasets 0.85, 0.85, 0.77, LGG datasets 0.80, 0.66, 0.51, and the combination of the two groups 0.88, 0.79, 0.77 for regions the whole tumor, tumor core, and enhancing region in the training dataset, respectively. The results related to Hussdorf Distance (HD) for HGG datasets were 8.24, 9.92, 4.43, LGG datasets 11.5, 11.31, 2.23, and the combination of the two groups 7.20, 8.82, 4.43 for regions the whole tumor, tumor core, and enhancing region in the training dataset, respectively.
Conclusion: Using the U-Net network can help physicians in the accurate segmentation of the tumor and its various areas, as well as increase the survival rate of these patients and improve their quality of life through accurate diagnosis and early treatment.
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Faezeh Moghadas, Zahra Amini, Rahele Kafieh,
Volume 80, Issue 10 (1-2023)
Abstract
Background: Brain-computer interface systems provide the possibility of communicating with the outside world without using physiological mediators for people with physical disabilities through brain signals. A popular type of BCIs is the motor imagery-based systems and one of the most important parts in the design of these systems is the classification of brain signals into different motor imagery classes in order to transform them into control commands. In this paper, a new method of brain signal classifying based on deep learning methods is presented.
Methods: This cross-sectional study was conducted at Isfahan University of Medical Sciences, School of Advanced Technologies in Medicine, from February 2020 to June 2022. In the pre-processing block, segmentation of brain signals, selection of suitable channels and filtering by Butterworth filter have been done; then data has transformed to the time-frequency domain by three different kinds of mother wavelets including Cmor, Mexicanhat, and Cgaus. In the classification step, two types of convolutional neural networks (one-dimensional and two-dimensional) were applied whereas each one of them was utilized in two different architectures. Finally, the performance of the networks has been investigated by each one of these three types of input data.
Results: Three channels were selected as the best ones for nine subjects. To separate 8-30 Hz, a 5th degree Butterworth filter was used. After finding the optimal parameters in the proposed networks, wavelet transform with Cgauss mother wavelet has the highest percentage in the both proposed architectures. Two-dimensional convolutional neural network has higher convergence speed, higher accuracy and more complexity of calculations. In terms of accuracy, precision, sensitivity and F1-score, two-dimensional convolutional neural network has performed better than one-dimensional convolutional neural network. The accuracy of 92.53%, which is obtained from the second architecture, as the best result, is reported.
Conclusion: The results obtained from the proposed network indicate that suitable, and well-designed deep learning networks can be utilized as an accurate tool for data classification in application of motion perception.
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Seyed Hossein Hosseini, Hossein Karimi Moonaghi , Seyed Masoud Hosseini, Hassan Gholami, Vahid Ghavami,
Volume 80, Issue 12 (3-2023)
Abstract
Background: According to numerous research related to learning styles and also the difference of these styles in students, this study was designed in order to determine the status of learning styles in medical students in Iran.
Methods: This study was conducted as a systematic review and meta-analysis. Searching for articles in this study was done from September 24 to October 15, 2022 in databases: Proquest, PubMed, Iran medex, Scopus, Sid, Magiran, Google Scholar, Eric and medical education journals. The research environment of Iran has been Mashhad. Using the PICOTS model, the keywords: learning styles, clubs, medical students were used to search the mentioned databases. OR, AND operators and possible combinations of keywords were used when searching for articles in databases. The extracted articles were first evaluated in terms of the research title, then the abstract of the article, and finally the text of the article using the "PRISMA Checklist". In each stage, repetitive articles and articles that did not mention the percentage of learning styles were excluded from the study, and the articles that met the inclusion criteria were stored in the (EndNote software, version 20, Clarivate, USA), and at the end, 53 articles were analyzed.
Results: The results of the study showed that the most used learning styles among students of medical sciences in Iran was convergent learning style (32% with 95% confidence interval). In the investigation of the adaptive learning style in the fields of basic sciences during the years 2006 to 2021, the percentage of using this style increased and this trend was statistically significant (P=0.0078).
Conclusion: According to the findings of the study, the most used learning style in medical sciences in Iran is convergent learning style, and considering the characteristics of convergent people, it is necessary to provide effective and efficient training in medical sciences to Students' learning styles should be given special attention so that training can be guided based on their learning styles.
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Hanieh Alimiri Dehbaghi , Karim Khoshgard, Hamid Sharini, Samira Jafari Khairabadi, Farhad Naleini,
Volume 81, Issue 5 (8-2023)
Abstract
Background: The use of artificial intelligence algorithms to help with accurate diagnosis in medical images is one of the most important applications of this technology in the field of medical imaging. In this research, the possibility of replacing simple chest radiography instead of CT scan using machine learning models to detect pneumothorax was investigated in cases where CT is usually requested.
Methods: This study is analytical and was conducted from November 2022 to May 2023 at Kermanshah University of Medical Sciences. The data used in this research was extracted from the files of 350 patients suspected of pneumothorax. The collected images were pre-processed in MATLAB software. Then, three machine learning algorithms, including Logistic elastic net regression (LENR), Logistic lasso regression (LLR) and Adaptive Boosting (AdaBoost) were used. To evaluate the performance of these models, the criteria of precision, accuracy, sensitivity, specificity, area under the receiver operating characteristic curve (AUC), F1 score, and misclassification were used.
Results: In the AdaBoost model, the accuracy value in radiographic and CT images was calculated as 98.89% and 98.63%, respectively, and the precision value was calculated as 99.17% and 98.27%, respectively. In radiographic images, the AUC value for AdaBoost model was calculated as 100% and in CT scan images as 96.96%. The F1 score for the same model in radiographic was 99% and in CT images was 98.68%. The specificity value for the AdaBoost model was calculated as 99.45% in radiographic images and 94.67% in CT scan images. In the LLR model, the AUC value for radiographic and CT scan images was 99.87% and 99.02%, respectively.
Conclusion: According to the criteria evaluated in the present study, two LLR and AdaBoost models have similar performance in radiographic and CT images in terms of pneumothorax detection ability, so that this complication can also be diagnosed with high precision level using machine learning techniques on the radiographic images and thus receiving higher levels of radiation doses due to CT scan can be avoided in these patients. |
Ameneh Javanmard, Alireza Salehan,
Volume 81, Issue 10 (1-2024)
Abstract
Background: Coronaviruses were discovered in 1960. Large-sized living organisms from the Coronaviridae family, with single-stranded RNA of animal origin. Coronaviruses in humans can cause mild respiratory illness or severe respiratory illness. In 2020, the World Health Organization declared COVID-19 a global pandemic. The aim of this study is to use the Jaccard similarity coefficient to determine the similarity of COVID-19 behavior patterns in different seasons of the year.
Methods: This study used machine learning systems and similarity metrics to determine the behavior pattern of COVID-19 in different seasons of the year. The location of research was the Mousa ibn Ja'far Hospital in Mashhad, and the time was from May 2020 to August 2021. The symptoms of affected patients were compared with the compiled dataset, and the similarity of patients was prepared in a similarity matrix, and the Jaccard correlation coefficient was calculated on the data. Finally, the analysis of strains from the beginning of emergence to the latest strain was examined. The performance indicators of the algorithm in the Jaccard similarity method showed a recall metric with a value of 0.94, a precision metric with a value of 1, an F1 score with a value of 0.86, and remove accuracy metric with a value of 0.76. The most important factors in the investigation include white blood cells, platelets, RT-PCR, CT SCAN, shortness of breath, fever, SPO2, and respiratory rate.
Results: The transmission of the COVID-19 virus depends on several factors, including human interaction. The evidence of the collected data shows that people with COVID-19 have low lymphocyte count and it is very consistent with the results of recent studies. Due to the lack of a dataset, a comparative study was conducted and a dataset was collected.
Conclusion: This study, leveraging machine learning algorithms, identified a clear seasonal correlation in the spread of COVID-19. Considering geographical and seasonal variations among patients, distinct symptoms were observed in each season corresponding to the prevalent strain during that period.
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