محمدعلی عقابیان
مرکز تحقیقات علوم و تکنولوژی در پزشکی، دانشکده فیزیک پزشکی، دانشگاه تهران، تهران
[ 1 ] - مدل‌سازی ریاضی و شبیه‌سازی به منظور بررسی اثر اندازه‌ی نانوذرات مغناطیسیِ حاملِ دارو در سیستم دارورسانی مغناطیسی
دارورسانی مغناطیسی، نوعی روش درمانی است که درآن، عاملهای دارویی ازبین برندهی تومور و یا سلولهای سرطانی، روی یک هستهی مغناطیسی بارگذاری شده است که با اِعمال یک میدان مغناطیسی خارجی، از حضور این داروها در سایر نقاط بدن و بافتهای سالم جلوگیری میکند. بدین صورت، اثرهای جانبی ناخواسته حاصلاز شیمی درمانیهای مرسوم به طور چشمگیری کاهش مییابد. این روش، موانع و مشکلاتی دارد که به نظر میرسد با به...
[ 2 ] - ارزیابی اثرات میدان الکترومغناطیس با شدت 5/1 تسلا بر شـــاخص‌های آزمون عملکرد و هیستومتری کبد در موش‌های صحرایی نر بالغ
بررسی‌های مختلف نشان داده‌اند که میدان‌های الکترومغناطیسی قوی اثرات سوئی برسلامت انسان دارند. دستگاه MRIاز مهم‌ترین تجهیزاتیست که در پزشکی برای تشخیص در بیماری‌های مختلف استفاده می‌شود. اساس کار این دستگاه مبتنی بر امواج الکترومغناطیس است که امکان ایجاد نارسایی در دستگاه‌های مختلف بدن از جمله کبد می‌شود. بر این اساس در این مقاله ا...
[ 3 ] - Feasibility assessment of in vitro chemoresponse assay on stereotactic biopsies of glioblastoma multiforms: a step towards personalized medicine
Objective(s):P In vitro chemosensitivity and resistance assays (CSRAs) are a promising tool for personalized treatment of glioblastoma multiform (GBM). These assays require a minimum of 1 to 2 g of tumor specimen for testing, but this amount is not always accessible. We aimed to assess the feasibility and validity of utilizing stereotactic biopsies of GBM in CSRAs. Materials and Methods: Single...
[ 4 ] - Comparison of Two Quantitative Susceptibility Mapping Measurement Methods Used For Anatomical Localization of the Iron-Incorporated Deep Brain Nuclei
Introduction Quantitative susceptibility mapping (QSM) is a new contrast mechanism in magnetic resonance imaging (MRI). The images produced by the QSM enable researchers and clinicians to easily localize specific structures of the brain, such as deep brain nuclei. These nuclei are targets in many clinical applications and therefore their easy localization is a must. In this study, we aimed to i...
[ 5 ] - Changes in Effective Connectivity Network Patterns in Drug Abusers, Treated With Different Methods
Introduction: Various treatment methods for drug abusers will result in different success rates. This is partly due to different neural assumptions and partly due to various rate of relapse in abusers because of different circumstances. Investigating the brain activation networks of treated subjects can reveal the hidden mechanisms of the therapeutic methods. Methods: We studied three groups o...
[ 6 ] - Exploring Neural Correlates of Different Dimensions in Drug Craving Self-Reports among Heroin Dependents
Introduction: Drug craving could be described as a motivational state which drives drug dependents towards drug seeking and use. Different types of self-reports such as craving feeling, desire and intention, wanting and need, imagery of use, and negative affect have been attributed to this motivational state. By using subjective self-reports for different correlates of drug craving along ...
[ 7 ] - Preparation and Characterization of Double Shell Fe3O4 Cluster@Nonporous SiO2@Mesoporous SiO2 Nanocomposite Spheres and Investigation of their In Vitro Biocompatibility
Background: Multifunctional core-shell magnetic nanocomposite particles with tunable characteristics have been paid much attention for biomedical applications in recent years. A rational design and suitable preparation method must be employed to be able to exploit attractive properties of magnetic nanocomposite particles. Objectives: Herein, we report on a simple approach for the synthesis of m...
[ 8 ] - Evaluation of Model-Based Methods in Estimating Dynamic Functional Connectivity of Brain Regions
Today, neuroscientists are interested in discovering human brain functions through brain networks. In this regard, the evaluation of dynamic changes in functional connectivity of the brain regions by using functional magnetic resonance imaging data has attracted their attention. In this paper, we focus on two model-based approaches, called the exponential weighted moving average model and the d...
[ 9 ] - Differentiation of Edematous, Tumoral and Normal Areas of Brain Using Diffusion Tensor and Neurite Orientation Dispersion and Density Imaging
Background: Presurigical planning for glioma tumor resection and radiotherapy treatment require proper delineation of tumoral and peritumoral areas of brain. Diffusion tensor imaging (DTI) is the most common mathematical model applied for diffusion weighted MRI data. Neurite orientation dispersion and density imaging (NODDI) is another mathematical model for DWI data modeling.Objective: We stud...
[ 10 ] - Effect of Physiological Noise on Thoraco-lumbar Spinal Cord FMRI in 3T Magnetic Field
Introduction: Functional MRI methods have been used to study sensorimotor processing in the Spinal cord. However, these techniques confront unwanted contributions to the measured signal from the physiological fluctuations. For the spinal cord imaging, most of the challenges are consequences of cardiac and respiratory movement artifacts that are considered as significant sources of noise, especi...
[ 11 ] - Iranian Brain Imaging Database: A Neuropsychiatric Database of Healthy Brain
Introduction: The Iranian Brain Imaging Database (IBID) was initiated in 2017, with 5 major goals: provide researchers easy access to a neuroimaging database, provide normative quantitative measures of the brain for clinical research purposes, study the aging profile of the brain, examine the association of brain structure and function, and join the ENIGMA consortium. Many prestigious databases...
[ 12 ] - Quantification of blood-brain-barrier permeability dysregulation and inflammatory activity in MS lesions by dynamic-contrast enhanced MR imaging
Objective: Measurement of blood-brain permeability dysfunction in active and chronic MS lesions with T1-weighted dynamic contrast-enhanced MRI to show variation in inflammatory activity Background: blood-brain-barrier perfusion characterization impaired in MS as some studies have shown recently buta comparison between perfusion parameters in contrast-enhanced and non-enhanced lesions not have ...
[ 13 ] - Different olfactory perception in heroin addicts: an fMRI study
Background: Addiction as a mental disorder has large adverse effects on brain health. It alters brain structure and deteriorates brain functionality. Impairment of brain cognition in drug addiction is illustrated in many previous works; however, olfactory perception in addiction and in particular the neuronal mechanisms of it are rarely studied. Methods: In this experiment, we recruited 20 he...