Showing 11 results for Neural
Mehrali Rahimi, Efat Mashhadi, Ebrahim Karimi,
Volume 10, Issue 3 (6-2007)
Abstract
Introduction: Diabetes mellitus is a chronic disease that has well known effects on most organs, but there have been controversies in few different studies about the effects of diabetes on hearing. So this study was carried out in 2003-2004 in Kermanshah Diabetes Research Center to assess the effect of diabetes on hearing. Materials and Methods: This is a case-control study. 82 diabetic cases (26 types I and 56 type 2 cases) were studied along with 82 controls matched both in age and sex. Cases were selected randomly, their range of age was 15 to 55 years and their duration of diabetes was more than 3 years. After completing questionnaires, all cases and controls undergone autoscopic examination. Those with other ear disease with hearing impairment were omitted. Audiometery including pure tone audiometery, speech audiometery, and impedance audiometrey with well tone AD19 formed was done on 164 (diabetic and control) persons. Data was analyzed using t-test. Results: Audiometric findings with different frequencies in the two groups revealed that there was a significant relationship between diabetes and hearing impairment (p<0.001). This relationship was more significant in high frequencie, older age and type 2 diabetes, but there were no relationship between control of blood sugar (HbA1c), duration of diabetes, sex, microvascular and macrovasculur complications with hearing loss in diabetic patients. Conclusion: These finding demonstrate that diabetes can cause mild to moderate hearing impairment especially in high frequencies. The mechanism of this effect is unknown. Complementary studies with more patients and with more accurate devices such as Otoacustic Emission (OAE) and Audiometric Brainstem Reflex (ABR) are recommended
Mohammad Reza Nikmaram,
Volume 10, Issue 4 (12-2007)
Abstract
Introduction: In resent years, neuronal type Na+ channel is one of the important currents for action potential depolarization phase in heart cells. In this study neuronal type Na+ channel is blocked by low concentration of Tetrodotoxin (TTX) to compare the effect of TTX blocker on pacemaker activity of sinoatrial node (SAN) and atrioventricular node (AVN) of mouse heart. Materials and Methods: In this experimental study the pacemaker activity of distinct intact SAN and AVN, was recorded before and during consuming 100 nM TTX, and cycle length (CL) was measured. Data was analyzed using t-test. Results: 100 nM TTX increased CL on SAN preparations by 22.2±6% and on AVN preparations by 52.5±13.5 %. These changes were significant in the two nodes. Conclusion: It is passible to conclude that the neuronal type Na+ channel was present in the two nodes, and the effect of TTX on CL of the two nodes was different.
Maryam Delphi, Mahsa Bakhit, Mojtaba Tavakoli, Ali Nikkhah, Azadeh Saki,
Volume 16, Issue 1 (4-2013)
Abstract
Background: ASSR is the latest threshold detection technology in pediatric audiology. The aim of this study is to investigate the degree to which ASSR thresholds correlate with click-ABR thresholds.
Materials and Methods: In this cross-sectional study, 32 children ranging in age from birth to 7 years were evaluated by ASSR and ABR in moderate to severe and severe to profound hearing loss groups.
Results: The correlation coefficients for frequencies of 500, 1000, 2000, and 4000, mean of 2-4 and mean of 1-4 kHz were between 0.68- 0.90 in moderate to severe hearing loss and 0.79-0.96 in severe to profound hearing loss.
Conclusion: Strong correlations were found between ASSR and click-ABR thresholds in all frequencies. This correlation was greater for higher degrees of hearing loss.
Mohsen Sagha, Ebrahim Esfandiari, Shanaz Razavi, Somayeh Tanhaee, Mohammad Hossein Nasr Esfahani, Hossein Baharvand,
Volume 16, Issue 4 (7-2013)
Abstract
Background: Retinoic acid (RA) is a vitamin A derivative and one of the most important inducing signals in vertebrates that is involved in differentiation, morphogenesis, apoptosis, and reproduction. This study was done to evaluate the role of RA in in vitro neural patterning of mouse embryonic stem cells (mESCs).
Materials and Methods: In this experimental study, upon formation, embryoid bodies (EBs) from mESCs, Royan B1, were induced by 1 µM RA for four days and then plated for eight days. Untreated EBs were considered as the control group. Finally, in both groups, neural induction and patterning of EB-derived neural cells were evaluated by using immunostaining, flowcytometry, and RT-PCR methods.
Results: RA induced neurogenesis in ES cells, from which 35% showed to express MAP2. RT-PCR analysis also indicated that RA-treated neural cells derived from ES cells could at the same time express Mash1, Pax6/7, and Dbx1/2 as dorso-ventral (DV) pattering markers and Hoxb4, Hoxc5, and Hoxc8 as the rostro-caudal (RC) axis markers.
Conclusion: RA induces in vitro neural induction along with neural patterning of ES-derived neural cells in DV and RC axes. Keywords: Mouse embryonic stem cells, neural patterning, retinoic acid
Mahsa Bagheri, Ali Pourmohammad, Ehsan Imani,
Volume 18, Issue 12 (3-2016)
Abstract
Background: The purpose of this research is to design a Brain-Computer Interface to discriminate the brain signals while the brain images four main directions. To be innovative, the subjects have imaged the aimed directions by power of imagination, and for the first time, the ICA algorithm has been used to detect the aimed signal and to eliminate the artifacts.
Materials and Methods: In this descriptive-ana alytic study, signals are recorded by using a Micromed device and a 19-channel helmet in unipolar mode. The statistical population included three persons in the age range of 25 to 30 and the designed task consisted of 24 slides of four main directions.
Results: Simulations have shown that the best classification accuracy was the outcome of the 2.5-second time windowing and the best choice for extracting features was the AR coefficients of 15 order. There was no significant difference between the classification accuracy of different implementation of the Artificial Neural Network classifier with different number of layers and neurons and different classification functions. In comparison with the Neural Network, the Linear Discriminant Analysis (LDA) showed better classification accuracies.
Conclusion: The results of this research are in accordance with the results of the methods such as FMRI and methods based on the brain signals in vowel imagination. In this research, the best classification accuracy was obtained from the Linear Discriminant Analysis classifier by extracting the target signal from the output of the ICA algorithm and extracting the AR coefficients as feature and the 2.5-second time windowing. The Linear Discriminant Analysis classifier result the best classification accuracies.
Behzad Abedi, Ataollah Abbasi, Yashar Sarbaz, Atefeh Goshvarpour,
Volume 19, Issue 3 (6-2016)
Abstract
Background: ALS is a progressive neuro-muscular disease, which is characterized by motor neuron loss in the Central Nervous System (CNS) and Peripheral Nervous System (PNS). Up to now, no accurate clinical method for diagnosis of the disease have been provided. In most cases, ALS patients are unable to walk normally due to abnormalities in the nervous system. For this reason, one of the most appropriate methods in the diagnosis of ALS from other neurological diseases or from healthy volunteers is the gait motor signal analysis.
Materials and Methods: In this study, gait signals available in Physionet database have been used. The database consists of 13 patients with ALS (ALS1, ALS2, …, ALS13) and 16 normal subjects (CO1, CO2, …, CO16). The patients participating in this study had no history of any psychiatric disorders and did not use any assistive device for walking, like wheelchair. The power spectrum of stride, swing, and stance of normal subjects and patients was computed for both left and right legs. To provide appropriate inputs for the classifier, the frequency band of the power spectrum of all signals was divided into eight equal parts. The area of all regions was computed. Three frequency band of the lower range of power spectra selected as inputs of the classifier.
Results: In this study, power spectra, as frequency attributes, were used to explore probable differences of time series in both patients and healthy subjects.
Conclusion: Artificial Neural Network was used to classify normal and ALS groups with the accuracy of 83% for the test data set. It seems that the present algorithm can be used in discriminating patients from normal subjects in the early stages of the disease.
Firoozeh Alavian, Sohrab Hajizadeh, Mohammad Javan, Roham Mazloom,
Volume 20, Issue 6 (9-2017)
Abstract
Abstract
Background: Recent studies indicate that hyperoxia has a significant therapeutic effect in the acute ischemic injury. The role of intracellular kinases, including ERK, has been posed in the phenomenon of ischemic tolerance. In the present study, the effect of intermittent normobaric hyperoxia on the activity of ERK in the stroke model was studied
Material and Methods: This is an experimental study. Animals include 4 groups (sham, hyperoxia–sham, stroke and hyperoxia–stroke); each group consisted of 6 male Wistar rats in the weight range of 250 to 350 grams. Hyperoxia groups were exposed to 95% inspired oxygen for 4 h/day and 6 consecutive days. Oxygen concentration in the control groups was 21% (normoxia, room air). After 24h, the stroke group animals were subjected to 60 min of right middle cerebral artery occlusion (MCAO). After 24h reperfusion, neurological deficit scores (NDS) and ERK activity were assessed.
Results: 5 hours after MCAO, stroke groups showed a significant increase in ERK activity in the cortex (p <0.01) and subcortex (p <0.001). At the same time, hyperoxia significantly increased the activity of ERK in cortex compared to the normoxia group (p<0.05). In subcortex, hyperoxia had no significant effect on ERK activity. Twenty-four hours after MCAO, stroke groups showed a significant reduction in ERK activity in the cortex (p <0.001) and subcortex (p <0.05). 24hr after MCAO, The activity of ERK in the hyperoxia groups; in both cortex and subcortex areas was significantly higher than that of the normoxia groups (p<0.05). Also, hyperoxia caused a significant decrease in NDS (p=0.0220).
Conclusion: Increased levels of ERK activity in the hyperoxia groups can be used to protect the nervous system, but the presence of other malicious factors may have been more effective in some cases, so that hyperoxia alone hasn’t been able to prevent stroke progression.
Atabak Shahed, Ali Asghar Ravasi, Sirous Choubineh, Davar Khodadadi,
Volume 20, Issue 11 (2-2018)
Abstract
Abstract
Background: The aim of this study was to investigate the effect of four weeks exercise prior preparation before Alzheimer's induction on the levels of nerve growth factor and beta amyloid in the hippocampus of Wistar male rats
Materials and Methods: 84 male Wistar rats (8 weeks old) with a weighing average of 20 ± 195 grams from Pasteur Institute of Iran were prepared, and rats were randomly divided to two exercise (4 weeks aerobic training on a treadmill with a gradient of 0 degrees, 5 days a week for 4 weeks) and rest groups. Then, the rats of each group were randomly assigned to 3 sub groups of 14 numbers, injection Aβ1-42, control, and non-injected. 48 hours after the last exercise session, injections into the hippocampus amyloid beta or Dimethyl sulfoxide were performed. Seven days after surgery, the rats of each group were randomly sacrificed or subjected to behavioral testing. To determine the levels of of nerve growth factor and beta amyloid Sampling was performed from the hippocampus and plasma of animals, a Morris water maze test was used for spatial memory test. Kolmogorov-Smirnov test (KS) and analysis of variance were used to analyze the data.
Results: The results of one-way analysis of variance showed that there was a significant difference between the levels of amylohyd of hippocampus and NGF in different groups. Also, the results of the probe test for spatial memory showed that the time spent on the target circle in the Aβ1-42 injection group was significantly lower than the other groups (p≤ 0.01). Also, the exercise and exercise + sham groups had a significantly better performance than control group.
Conclusion: It seems that performing physical activity before induction of Alzheimer's in rats is a kind of countermeasures and preeclampsia with physiological disorders and progression of the disease.
Arman Zamani, Abolghasem Babaei, Nayyer Sadat Mostafavi,
Volume 22, Issue 1 (4-2019)
Abstract
Background and Aim: Diagnosis of leukemia is very difficult, therefore, it is necessary to use image processing techniques. The main objective of this study was to provide a system based on intelligent models that could improve the accuracy of the diagnostic system for acute leukemia.
Materials and Methods: The images produced in this study were extracted from the University Degli Studi Dimilan database and processed in the MATlab 2014a software. In this research, Fuzzy-Cmeans method was used in fragmentation and neural network and support vector machine in classification networks.
Ethical Considerations: In this study, all principles of research ethics were considered.
Findings: Feature data were extracted using the original image transfer to RGB, HSV, Lab and Enhanced RGB spaces. The data obtained from the previous step were entered into the SVM network, then the network separated normal data from abnormal data. The results of comparing the output of the proposed method with different educational methods showed the highest mean of accuracy equal to 95.7%.
Conclusion: The application of the proposed network in this study was that eliminate the weak points of all the networks in addition to presenting the advantages of these network. Combining the networks improved the accuracy of output up to 98% and considerably reduced the time required for calculations.
Majid Mehrad, Majid Nojavan, Sedigh Raissi, Mehrdad Javadi,
Volume 25, Issue 2 (5-2022)
Abstract
Background and Aim Most heart diseases show symptoms on ECG, but diagnosing heart disease with ECG requires the knowledge and experience of medical specialized. Because these specialists may not always be available, it is necessary to design tools to diagnose heart disease in these situations. In this paper, a two-stage approach based on artificial neural networks is designed to diagnose heart disease using ECG information.In this study, we aim to propose a two-stage approach using artificial neural network (ANN) to diagnose heart disease based ECG data.
Methods & Materials To design the proposed approach, first the ECG data of 861 patients referred to medical centers in Arak, Iran were collected. The data were examined based on the opinions of specialists. Then, 154 features from ECG were used as inputs to the proposed model. In the first stage, an ANN was used to detect the ECG status (usable and unusable). In the second stage, using the usable ECG data, an ANN was used to diagnose the presence or absence of heart disease. Finally, the performance of the two-stage approach was evaluated and its accuracy and precision in determining the ECG quality and heart disease diagnosis were determined.
Ethical Considerations This study was approved by the ethics committee of Arak University of Medical Sciences (Code: IR.ARAKMU.REC.1400.138).
Results In the proposed approach, the ANN used for the determining the ECG status had a precision of 97.1% and an accuracy of 97.3%. The ANN used for the diagnosis of heart disease had a precision of 95.8% and an accuracy of 95.4%.
Conclusion Considering the high efficiency of the proposed approach in determining of ECG status and diagnosing heart disease, it is possible to use this approach to help the treatment staff.
Abolfazl Kalantari, Hamid Rajabi, Pezhman Motamedi, Leila Poursaadat, Abbas Saremi,
Volume 25, Issue 6 (3-2023)
Abstract
Introduction: Increasing skeletal muscle contraction ability via increasing its neural stimulations, is one of the methods can be effective in sport performance improvement. The aim of the present study was to evaluate the effect of supramaximal isometric conditioning contractions on muscle neural excitation and performance indices during bench press exercise.
Methods: Current research is a semi experimental study performed on 8 athlete men. Age range of them was 19 – 23. Doing resistance trainings was a part of their exercise program at least 2 months before study onset. Bench press with Barbell was used in the protocol of these study. Electromyography was used in order to assay the neural excitation of main muscles which are activated during bench press. In addition, 1-RM test was done so as to assess the performance of these muscles. The protocol of this study was approved by the ethics committee of Arak University of Medical Sciences (Code: IR.ARAKMU.REC.1400.357). All subjects participated in this study voluntarily and they had no illness or injury at the start of the research.
Results: Neural excitation and performance of the muscles increased significantly during strength bench press, following conditioning contractions. This research was reviewed in Islamic Azad University - Arak Unit and approved with the ethics code IR.IAU.ARAK.REC.1401.096. Informed consent was obtained from the participants and they were assured that their information would be confidential
Conclusions: Doing supramaximal isometric conditioning contractions prior to doing strength bench press with barbell, increased neural excitation and performance indices of main muscles activated in this exercise.
