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    Individual virtual phantom reconstruction for organ dosimetry based on standard available phantoms

    , Article Iranian Journal of Radiation Research ; Volume 7, Issue 4 , 2010 , Pages 201-206 ; 23223243 (ISSN) Babapour Mofrad, F ; Aghaeizadeh Zoroofi, R ; Tehrani Fard, A. A ; Akhlaghpoor, S ; Chen, Y. W ; Sato, Y ; Sharif University of Technology
    Novim Medical Radiation Institute  2010
    Background: In nuclear medicine application often it is required to use computational methods for evaluation of organ absorbed dose. Monte Carlo simulation and phantoms have been used in many works before. The shape, size and volume in organs are varied, and this variation will produce error in dose calculation if no correction is applied. Materials and Methods: A computational framework for constructing individual phantom for dosimetry was performed on five liver CT scan data sets of Japanese normal individuals. The Zubal phantom was used as an original phantom to be adjusted by each individual data set. This registration was done by Spherical Harmonics (SH) and Thin-Plate Spline methods.... 

    Classification of asthma based on nonlinear analysis of breathing pattern

    , Article PLoS ONE ; Volume 11, Issue 1 , 2016 ; 19326203 (ISSN) Raoufy, M. R ; Ghafari, T ; Darooei, R ; Nazari, M ; Mahdaviani, S. A ; Eslaminejad, A. R ; Almasnia, M ; Gharibzadeh, S ; Mani, A. R ; Hajizadeh, S ; Sharif University of Technology
    Public Library of Science  2016
    Normal human breathing exhibits complex variability in both respiratory rhythm and volume. Analyzing such nonlinear fluctuations may provide clinically relevant information in patients with complex illnesses such as asthma. We compared the cycle-by-cycle fluctuations of inter-breath interval (IBI) and lung volume (LV) among healthy volunteers and patients with various types of asthma. Continuous respiratory datasets were collected from forty agematched men including 10 healthy volunteers, 10 patients with controlled atopic asthma, 10 patients with uncontrolled atopic asthma, and 10 patients with uncontrolled non-atopic asthma during 60 min spontaneous breathing. Complexity of breathing... 

    Electrospinning of nanodiamond-modified polysaccharide nanofibers with physico-mechanical properties close to natural skins

    , Article Marine Drugs ; Volume 14, Issue 7 , 2016 ; 16603397 (ISSN) Mahdavi, M ; Mahmoudi, N ; Rezaie Anaran, F ; Simchi, A ; Sharif University of Technology
    MDPI AG 
    Electrospinning of biopolymers has gained significant interest for the fabrication of fibrous mats for potential applications in tissue engineering, particularly for wound dressing and skin regeneration. In this study, for the first time, we report successful electrospinning of chitosan-based biopolymers containing bacterial cellulous (33 wt %) and medical grade nanodiamonds (MND) (3 nm; up to 3 wt %). Morphological studies by scanning electron microscopy showed that long and uniform fibers with controllable diameters from 80 to 170 nm were prepared. Introducing diamond nanoparticles facilitated the electrospinning process with a decrease in the size of fibers. Fourier transform infrared... 

    Characteristics of early repolarization pattern in the Iranian population

    , Article Iranian Red Crescent Medical Journal ; Volume 19, Issue 3 , 2017 ; 20741804 (ISSN) Mollazadeh, R ; Sehhati, F ; Eslami, M ; Nemati, F ; Monfarednasab, M ; Sefidbakht, S ; Sharif University of Technology
    Kowsar Medical Publishing Company  2017
    Background: The early repolarization pattern (ERP) has been considered a normal variant in electrocardiography (ECG) for a long time. Nevertheless, increasing evidence has demonstrated its association with adverse outcomes. Objectives: The present study aimed to evaluate the prevalence of ERP in the Iranian general population and demonstrate its clinical and ECG correlates. Methods: A cross sectional study, comprising 1424 consecutive healthy adult individuals, was conducted at two university based hospitals in Tehran, Iran in 2012-2013. The ERP prevalence, clinical characteristics and ECG morphology were investigated in volunteers. Results: ERP was present in 136 out of 1,424 people (9.6%).... 

    Inverted perovskite solar cells based on lithium-functionalized graphene oxide as an electron-transporting layer

    , Article Chemical Communications ; Volume 53, Issue 10 , 2017 , Pages 1630-1633 ; 13597345 (ISSN) Nouri, E ; Mohammadi, M. R ; Lianos, P ; Sharif University of Technology
    Royal Society of Chemistry  2017
    Perovskite solar cells with an inverted p-i-n architecture were constructed under ambient conditions by employing materials of lower cost than standard cells. Thus, graphene oxide was used as a hole transporting material and Li-modified graphene oxide as an electron transporting material, while Al was used as a counter electrode. A maximum solar conversion efficiency of 10.2% was achieved by adding a Ti-based sol on the top of the Li-modified graphene oxide layer. © The Royal Society of Chemistry  

    Investigation of cervical spine curvature in females with postural neck pain

    , Article Journal of Zanjan University of Medical Sciences and Health Services ; Volume 25, Issue 110 , 2017 , Pages 110-119 ; 16069366 (ISSN) Salahzadeh, Z ; Maroufi, N ; Ahmadi, A ; Behtash, H ; Hazhir Sahneh, S ; Parnianpour, M ; Sharif University of Technology
    Zanjan University of Medical Sciences and Health Services  2017
    Background and Objective: Changes in the cervical spine curvature leads to increased shear force and compression stress on cervical spine and axial loading in different cervical segments. The objective of this study was to compare the general and segmental curvature in the upper and lower cervical spine of women with postural neck pain and Forward Head Posture (FHP), women without neck pain but with FHP and healthy women. Material and Methods: 45 women were divided into three groups: 15 women with postural neck pain and FHP, 15 women without neck pain but with FHP and 15 healthy women. Photography was used to assess neck posture while cervical spine curvature was measured using fluoroscopy... 

    Correlation between trunk-pelvis inter-segmental coordination parameters during walking and disability level in chronic low back pain patients

    , Article Journal of Biomedical Physics and Engineering ; Volume 8, Issue 2 , 2018 , Pages 193-202 ; 22517200 (ISSN) Ebrahimi, S ; Kamali, F ; Razeghi, M ; Haghpanah, A ; Sharif University of Technology
    Shiraz University of Medical Sciences  2018
    Background: Chronic low back pain (CLBP) disability has been particularly frustrating because its treatment has been a great therapeutic challenge. Disability has been suggested to depend on different factors that should be found and considered in the medical management. The inter-segmental coordination is often impaired in CLBP subjects; however, to the best of our knowledge, there is no evidence about the relationship between the existence of coordination problems and disability in CLBP patients. Objective: To evaluate the correlation between sagittal plane trunk-pelvis intersegmental coordination parameters during walking and disability level in CLBP patients. Methods: Kinematic data were... 

    Imprinted silica nanofiber formation via sol-gel-electrospinning for selective micro solid phase extraction

    , Article New Journal of Chemistry ; Volume 42, Issue 16 , 2018 , Pages 13864-13872 ; 11440546 (ISSN) Asgari, S ; Bagheri, H ; Es Haghi, A ; Sharif University of Technology
    Royal Society of Chemistry  2018
    Sol composition and ripening conditions are two important parameters in silica fiber production through the conventional sol-gel process. In the current study, silica nanofibers were successfully obtained via the electrospinning technique, and sol-gel formation occurred during this process. Based on previous reports, with the aim of increasing the selectivity, we used the molecular imprinted methodology to produce a selective medium via sol-gel electrospinning. In this process, sol-gel was formed during electrospinning and then, the backbone polymer was removed by heating. To obtain a thin layer of silica nanofibers, the influencing parameters such as backbone polymer types, imprinting time... 

    The controlled release of dexamethasone sodium phosphate from bioactive electrospun PCL/gelatin nanofiber scaffold

    , Article Iranian Journal of Pharmaceutical Research ; Volume 18, Issue 1 , 2019 , Pages 111-124 ; 17350328 (ISSN) Boroojeni, F. R ; Mashayekhan, S ; Abbaszadeh, H. A ; Sharif University of Technology
    Iranian Journal of Pharmaceutical Research  2019
    In this study, a system of dexamethasone sodium phosphate (DEXP)-loaded chitosan nanoparticles embedded in poly-ε-caprolacton (PCL) and gelatin electrospun nanofiber scaffold was introduced with potential therapeutic application for treatment of the nervous system. Besides anti-inflammatory properties, DEXP act through its glucocorticoid receptors, which are involved in the inhibition of astrocyte proliferation and microglial activation. Bovine serum albumin (BSA) was used to improve the encapsulation efficiency of DEXP within chitosan nanoparticles and to overcome its initial burst release. BSA incorporation within the chitosan nanoparticles increased the encapsulation efficiency of DEXP... 

    Evaluation of the effects of fullerene c60 nanoparticles on oxidative stress parameters in normal rats liver and brain

    , Article Journal of Advances in Medical and Biomedical Research ; Volume 27, Issue 124 , 2019 , Pages 8-15 ; 26766264 (ISSN) Namadr, F ; Bahrami, F ; Bahri, Z ; Ghanbari, B ; Elahi, S. A ; Mohammadi, M. T ; Sharif University of Technology
    Zanjan University of Medical Sciences and Health Services  2019
    Background & Objective: The potent antioxidant property of fullerene C60 nanoparticles and their derivatives has been demonstrated in a wide range of in vitro and in vivo studies. Hence, we examined the effects of fullerene C60 on the oxidative stress parameters in brain and liver of the rats in normal situation. Materials & Methods: The study was performed in two groups of Wistar rats (each group, n = 6); normal and fullerene-treated normal animals. Treated rats received fullerene via oral gavage at dose of 1 mg/kg/day for 60 days. At termination of the study, the oxidative stress parameters were determined in brain and liver tissues, including the contents of glutathione (GSH) and... 

    The effect of lumbosacral orthosis on the thickness of deep trunk muscles using ultrasound imaging: a randomized controlled trial in patients with chronic low back pain

    , Article American Journal of Physical Medicine and Rehabilitation ; Volume 98, Issue 7 , 2019 , Pages 536-544 ; 08949115 (ISSN) Azadinia, F ; Takamjani, I. E ; Kamyab, M ; Kalbassi, G ; Sarrafzadeh, J ; Parnianpour, M ; Sharif University of Technology
    Lippincott Williams and Wilkins  2019
    Objective This study was conducted to evaluate the changes occurring in the thickness of deep trunk muscles, measured using ultrasound imaging, after 4 wks of lumbosacral orthosis use in conjunction with routine physical therapy. Design This parallel-group, randomized, controlled trial was conducted on 44 patients with nonspecific chronic low back pain, randomly allocated to the experimental and control groups. Both groups received eight sessions of physical therapy twice per week for 4 wks. The experimental group wore nonextensible lumbosacral orthosis, in addition to undergoing routine physical therapy. The thickness of the transversus abdominis, obliquus internus, and lumbar multifidus... 

    Detection of change to SSVEPs using analysis of phase space topological : a novel approach

    , Article Neurophysiology ; Volume 51, Issue 3 , 2019 , Pages 180-190 ; 00902977 (ISSN) Soroush, M. Z ; Maghooli, K ; Pisheh, N. F ; Mohammadi, M ; Soroush, P. Z ; Tahvilian, P ; Sharif University of Technology
    Springer New York LLC  2019
    A novel method based on EEG nonlinear analysis and analysis of steady-state visual evoked potentials (SSVEPs) has been processed. The EEG phase space is reconstructed, and some new geometrical features are extracted. Statistical analysis is carried out based on ANOVA, and most significant features are selected and then fed into a multi-class support vector machine (MSVM). Both offline and online phases are considered to fully address SSVEP detection. In the offline mode, the whole design evaluation, feature selection, and classifier training are performed. In the online scenario, the proposed method is evaluated and the detection rate is reported for both phases. Subject-dependent and... 

    Engineering 3D parallelized microfluidic droplet generators with equal flow profiles by computational fluid dynamics and stereolithographic printing

    , Article Lab on a Chip ; Volume 20, Issue 3 , 2020 , Pages 490-495 Kamperman, T ; Teixeira, L. M ; Salehi, S. S ; Kerckhofs, G ; Guyot, Y ; Geven, M ; Geris, L ; Grijpma, D ; Blanquer, S ; Leijten, J ; Sharif University of Technology
    Royal Society of Chemistry  2020
    Microfluidic droplet generators excel in generating monodisperse micrometer-sized droplets and particles. However, the low throughput of conventional droplet generators hinders their clinical and industrial translation. Current approaches to parallelize microdevices are challenged by the two-dimensional nature of the standard fabrication methods. Here, we report the facile production of three-dimensionally (3D) parallelized microfluidic droplet generators consisting of stacked and radially multiplexed channel designs. Computational fluid dynamics simulations form the design basis for a microflow distributor that ensures similar flow rates through all droplet generators. Stereolithography is... 

    Noninvasive fetal ECG extraction using doubly constrained block-term decomposition

    , Article Mathematical Biosciences and Engineering ; Volume 17, Issue 1 , 2020 , Pages 144-159 Mousavian, I ; Shamsollahi, M. B ; Fatemizadeh, E ; Sharif University of Technology
    American Institute of Mathematical Sciences  2020
    Fetal electrocardiogram (fECG) monitoring is a beneficial method for assessing fetal health and diagnosing the fetal cardiac condition during pregnancy. In this study, an algorithm is proposed to extract fECG from maternal abdominal signals based on doubly constrained block-term (DoCoBT) tensor decomposition. This tensor decomposition method is constrained by quasi-periodicity constraints of fetal and maternal ECG signals. Tensor decompositions are more powerful tools than matrix decomposition, due to employing more information for source separation. Tensorizing abdominal signals and using periodicity constraints of fetal and maternal ECG, appropriately separates subspaces of the mother, the... 

    Metabolic profiling of seminal plasma from teratozoospermia patients

    , Article Journal of Pharmaceutical and Biomedical Analysis ; Volume 178 , January , 2020 Mehrparvar, B ; Chashmniam, S ; Nobakht, F ; Amini, M ; Javidi, A ; Minai Tehrani, A ; Arjmand, B ; Gilany, K ; Sharif University of Technology
    Elsevier B. V  2020
    Teratozoospermia is one of conditions that can cause male infertility. The mechanism of teratozoospermia remains unclear. The knowledge of the metabolites in human seminal plasma (HSP) is meaningful for the pathological study of teratozoospermia. Analysis of changed metabolites in HSP can help understand the cellular mechanism, find the novel biomarkers and subsequently design a diagnosis test. In this study, the analysis of samples performed by proton nuclear magnetic resonance spectroscopy (1H NMR spectroscopy) to identify the various metabolites, with the aim of finding metabolic profiles and biomarkers related to male infertility. Eighteen de-regulated metabolites were identified in... 

    QSAR analysis of platelet-derived growth inhibitors using GA-ANN and shuffling crossvalidation

    , Article QSAR and Combinatorial Science ; Volume 27, Issue 6 , 2008 , Pages 750-757 ; 1611020X (ISSN) Jalali Heravi, M ; Asadollahi Baboli, M ; Sharif University of Technology
    Quantitative Structure - Activity Relationship (QSAR) models for the inhibition action of some 1-phenylbenzimidazoles on platelet-derived growth are constructed using Genetic Algorithm and Artificial Neural Network (GA-ANN) method. The statistical parameters of R2 and root-mean-square error are 0.82 and 0.21, respectively using this method. These parameters show a considerable improvement compared to the stepwise multiple linear regression combined with ANN (stepwise MLR-ANN). Ten-fold shuffling crossvalidations are carried out to select the most important descriptors. Five descriptors of index of Balaban (J), average molecular weight (AMW), 3D-Wiener index (W3D), mean atomic van der Waals... 

    The influence of temperature alterations on eccentric contraction-induced isometric force and desmin loss in ratmedial gastrocnemius muscle

    , Article Journal of Medical Sciences ; Volume 8, Issue 2 , 2008 , Pages 162-169 ; 16824474 (ISSN) Vasaghi Gharamaleki, B ; Keshavarz, M ; Gharibzadeh, S ; Sotodeh, M ; Marvi, H ; Mosayebnejad, J ; Ebrahimi Takamjani, I ; Sharif University of Technology
    In this study isolated perfused rat muscle was used to examine the direct effect of temperature changes on the eccentric contraction-induced force and desmin loss. The left medial gastrocnemius muscle was separated and the entire lower limb was transferred into a prewarmed (35°C) organ bath. Temperature was adjusted to 31 or 39°C before and during eccentric contractions. Maximal isometric force and desmin loss were measured after 15 isometric or eccentric contractions. According to our data, organ bath temperature changes before or during eccentric contractions had no significant effect on force loss. However, a strong correlation between desmin loss and temperature changes before (r = 0.93,... 

    Effect of stitter speed and aeration rate on the production of glucose oxidase by Aspergillus niger

    , Article Journal of Biological Sciences ; Volume 7, Issue 2 , 2007 , Pages 270-275 ; 17273048 (ISSN) Jafari, A. R ; Sarrafzadeh, M. H ; Alemzadeh, I ; Vosoughi, M ; Sharif University of Technology
    Asian Network for Scientific Information  2007
    Dissolved oxygen tension and shear stress as two very important factors in fungal fermentation were studied in the batch cultures of Aspergillus niger. The intention was to maximize the total activity of glucose oxidase produced in a 5-1 bench-top bioreactor. 300 rpm found to be optimum for enzyme production, however in higher mixing rates higher growth was achieved. The maximum activity of glucose oxidase was obtained in 1.5 vvm while the best aeration rate for growth was 2 vvm. Glucose oxidase with the activity of 548 U mL-1 was produced in 1.5 vvm and 300 rpm as the optimum conditions. © 2007 Asian Network for Scientific Information  

    Evaluation of bio-compatible poly(ethylene glycol)-based solid-phase microextraction fiber for in vivo pharmacokinetic studies of diazepam in dogs

    , Article Analyst ; Volume 132, Issue 7 , 2007 , Pages 672-678 ; 00032654 (ISSN) Es-Haghi, A ; Zhang, X ; Musteata, F. M ; Bagheri, H ; Pawliszyn, J ; Sharif University of Technology
    Royal Society of Chemistry  2007
    Solid-phase microextraction probes based on poly(ethylene glycol)/C18-bonded silica were used for in vivo monitoring of drugs from circulating blood of beagles, over a period of 8 h. After sampling, the extracted drugs were subsequently quantified by liquid chromatography coupled with tandem mass spectrometry. External calibrations in whole blood and phosphate-buffered saline were used to correlate the amount of analytes extracted in regard to the total and free concentrations in blood respectively. The probe provided sufficient sensitivity for the drugs in the blood matrix, while the need for drawing blood was eliminated. The limit of detections of the method from whole blood were 1.7, 1.4... 

    Analysis of non-stationary data for heart-rate fluctuations in terms of drift and diffusion coefficients

    , Article Journal of Biological Physics ; Volume 32, Issue 2 , 2006 , Pages 117-128 ; 00920606 (ISSN) Ghasemi, F ; Sahimi, M ; Peinke, J ; Rahimi Tabar, M. R ; Sharif University of Technology
    We describe a method for analyzing the stochasticity in non-stationary data for the beat-to-beat fluctuations in the heart rates of healthy subjects, as well as those with congestive heart failure. The method analyzes the return time series of the data as a Markov process, and computes the Markov time scale, i.e., the time scale over which the data are a Markov process. We also construct an effective stochastic continuum equation for the return series. We show that the drift and diffusion coefficients, as well as the amplitude of the return time series for healthy subjects are distinct from those with CHF. Thus, the method may potentially provide a diagnostic tool for distinguishing healthy...