Sharif Digital Repository

Background: Nonalcoholic fatty liver disease (NAFLD) is the most abundant chronic liver disorder, because racial and ethnic differences may influence prevalence and severity of NAFLD. Objectives: This metabolomic study was conducted to identify the metabolic biomarkers and determine the mechanism of progress of NAFLD in Iranian patients. Methods: Serum samples were collected from 75 participants (37 healthy controls and 38 patients with NAFLD) after an overnight fast. The metabolome of all samples were determined by nuclear magnetic resonance (NMR) and were compared by multivariate statistical analysis. Results: Totally, 19 metabolomic biomarkers were identified by NMR. Compared to healthy... 

Background & objectives: Malaria is the most important mosquito-borne disease in Iran. It is endemic in south to southeastern part of the country. Knowledge about bio-ecology of vectors will support authorities for appropriate management of the disease. Bashagard district is one of the main endemic areas for malaria in south of Iran. This study was conducted to determine anopheline fauna, diversity and affinity in the area, characterization of larval habitats, and mapping their potential distribution across the district. Methods: The potential aquatic habitats for Anopheles larvae were extracted from Indian Remote Sensing Satellite (IRS) image and digital elevation model of the area using... 

Introduction: Some tinnitus subjects habituate to their tinnitus but some others do not and complain of its annoyance tremendously. Normal sensory memory and change detection processes are needed for detecting the tinnitus signal as a prediction error and habituation to tinnitus. The purpose of this study was to compare auditory mismatch negativity as the index of sensory memory and change detection among the studied groups to search for the factors involving in the perception of tinnitus and preventing habituation in decompensated tinnitus subjects. Methods: Electroencephalography was recorded from scalp electrodes in compensated tinnitus, decompensated tinnitus, and no tinnitus control... 

Early onset adjacent segment degeneration (ASD) can be found within six months after anterior cervical discectomy and fusion (ACDF). Deficits in deep paraspinal neck muscles may be related to early onset ASD. This study aimed to determine whether the morphometry of preoperative deep neck muscles (multifidus and semispinalis cervicis) predicted early onset ASD in patients with ACDF. Thirty-two cases of early onset ASD after a two-level ACDF and 30 matched non-ASD cases were identified from a large-scale cohort. The preoperative total cross-sectional area (CSA) of bilateral deep neck muscles and the lean muscle CSAs from C3 to C7 levels were measured manually on T2-weighted magnetic resonance... 

Providing home hemodialysis (HHD) therapy is a complex process that not only requires the use of a complex technology but also involves a diverse group of stakeholders, and each stakeholder has their requirements and may not share a common interest. Bringing them together will require the alignment of their interests. A process management perspective can help to accomplish the alignment of their interests. To align their interests, it is crucial to identify interest groups and understand their interests. The main objective of this paper is to identify the stakeholders and represents their interests as a list of requirements in the HHD process. An extensive literature review has been carried... 

Retinoblastoma is the most frequent primary intraocular tumour in childhood. Early detection of retinoblastoma is the key to successful management with a higher chance of survival. This study aims to assess the knowledge of the general population and healthcare providers about retinoblastoma in term of presentation, risk factors, timing for diagnosis, and complications. A cross-sectional study using an online survey was conducted in three Arab countries (Jordan, Saudi Arabia, and Iraq) between 28 August and 16 September 2020. The questionnaire tool was constructed based on an extensive literature review to explore the study's aim and objectives. Logistic regression was used to identify... 

Anxiety is among the most debilitating nonmotor symptoms of Parkinson's disease (PD). This study aimed to determine how PD patients with low and high levels of anxiety (LA-PD and HA-PD, respectively) compare with age- and sex-matched controls at the level of motor control of reach-to-grasp movements during single- and dual-task conditions with varying complexity. Reach-to-grasp movement kinematics were assessed in 20 LA-PD, 20 HA-PD, and 20 sex- and age-matched healthy controls under single- as well as easy and difficult dual-task conditions. Assessment of PD patients was performed during both the on- and off-drug phases. The results obtained during dual-task conditions reveal deficits in... 

Freezing of gait (FOG) is a debilitating symptom in patients with Parkinson's disease (PD), which may be associated with motor control impairments in tasks other than gait. This study aimed to examine whether symmetric and asymmetric bimanual coordination is impaired in PD with FOG (PD +FOG) patients and whether dual-task and drug phases may affect bimanual coordination in these patients. Twenty PD +FOG patients, 20 PD patients without FOG (PD –FOG) performed symmetric and asymmetric functional bimanual tasks (reach to and pick up a box and open a drawer to press a pushbutton inside it, respectively) under single-task and dual-task conditions. PD patients were evaluated during on- and... 

In this case–control study, class І and ІІ human leukocyte antigen (HLA) alleles in Iranian patients with benign and severe cutaneous adverse drug reactions (CADRs) due to aromatic anticonvulsants and antibiotics were evaluated. Patients diagnosed with CADRs (based on clinical and laboratory findings) with a Naranjo score of ≥ 4 underwent blood sampling and HLA-DNA typing. The control group comprised 90 healthy Iranian adults. Alleles with a frequency of more than two were reported. Deviations from Hardy–Weinberg equilibrium were not observed. Eighty patients with CADRs including 54 females and 26 males with a mean age of 41.49 ± 16.08 years were enrolled in this study. The culprit drugs... 

This article summarizes the first and second Iranian brain-computer interface competitions held in 2017 and 2018 by the National Brain Mapping Lab. Two 64-channel electroencephalography (EEG) datasets were contributed, including motor imagery as well as motor execution by three limbs. The competitors were asked to classify the type of motor imagination or execution based on EEG signals in the first competition and the type of executed motion as well as the movement onset in the second competition. Here, we provide an overview of the datasets, the tasks, the evaluation criteria, and the methods proposed by the top-ranked teams. We also report the results achieved with the submitted algorithms... 

Introduction: Paranormal beliefs are defined as the belief in extrasensory perception, precognition, witchcraft, and telekinesis, magical thinking, psychokinesis, superstitions. Previous studies corroborate that executive brain functions underpin paranormal beliefs. To test this hypotheses, neurophysiological studies of brain activity are required. Methods: A sample of 20 students (10 girls, Mean±SD age: 22.50±4.07 years) were included in the current study. The absolute power of resting-state electroencephalogram (EEG) was analyzed in intra-hemispheric and inter-hemispheric coherence with eyes open. The paranormal beliefs were determined based on the total score of the revised paranormal... 

Signal Transducer and Activator of Transcription (STAT) pathway is functionally located downstream of Janus kinases proteins and can integrate signals from diverse pathways, thus regulating several aspects of immune responses. Although contribution of STAT proteins in the pathogenesis of several inflammatory conditions has been confirmed, their role in the development of periodontitis has been less appraised. Thus, we assessed levels of STAT transcripts in the periodontal tissues and circulation of affected individuals compared with the corresponding controls. Expression of STAT1 was remarkably lower in tissues samples of patients compared with control tissues (Ratio of mean expression (RME)... 

Alzheimer's Disease (AD) begins several years before the symptoms develop. It starts with Mild Cognitive Impairment (MCI) which can be separated into Early MCI and Late MCI (EMCI and LMCI). Functional connectivity analysis and classification are done among the different stages of illness with Functional Magnetic Resonance Imaging (fMRI). In this study, in addition to the four stages including healthy, EMCI, LMCI, and AD, the patients have been tracked for a year. Indeed, the classification has been done among 7 groups to analyze the functional connectivity changes in one year in different stages. After generating the functional connectivity graphs for eliminating the weak links, three... 

There are limitations in current medications of articular cartilage injuries. Although injectable bioactive hydrogels are promising options, they have decreased biomechanical performance. Researchers should consider many factors when providing solutions to overcome these challenges. In this study, we created an injectable composite hydrogel from chitosan and human acellular cartilage extracellular matrix (ECM) particles. In order to enhance its mechanical properties, we reinforced this hydrogel with microporous microspheres composed of the same materials as the structural building blocks of the scaffold. Articular cartilage from human donors was decellularized by a combination of physical,... 

Background: Focal segmental glomerulosclerosis (FSGS) is considered one of the most severe glomerular diseases and around 80% of cases are resistant to steroid treatment. Since a large proportion of steroid-resistant (SR) FSGS patients progress to end-stage renal disease, other therapeutic strategies may benefit this population. However, identification of non-invasive biomarkers to predict this high-risk population is needed. Objective: We aimed to identify the biomarker candidates to distinguish SR from steroid-sensitive (SS) patients using metabolomics approach and to identify the possible molecular mechanism of resistance. Methods: Urine was collected from biopsy-proven FSGS patients... 

A detailed 3D Monte Carlo simulation of the grid geometrical parameters in screen-film mammography (SFM) and digital mammography (DM) systems has been performed. A combination of IEC 60627:2013 international standard conditions and other more clinically relevant parameters were used for this simulation. Accuracy of our results has been benchmarked with previously published data and good agreement has been obtained. Calculations in a wide range of linear anti-scatter grid geometries have been carried out. The evaluated parameters for the SFM system were the Bucky factor (BF) and contrast improvement factor (CIF) and for the DM system it was signal differenceto- noise ratio improvement factor... 

We propose a new image recovery method to improve the resolution in microwave imaging applications. Scattered field data obtained from a simplified breast model with closely located targets is used to formulate an electromagnetic inverse scattering problem, which is then solved using the Distorted Born Iterative Method (DBIM). At each iteration of the DBIM method, an underdetermined set of linear equations is solved using our proposed sparse recovery algorithm, IMATCS. Our results demonstrate the ability of the proposed method to recover small targets in cases where traditional DBIM approaches fail. Furthermore, in order to regularize the sparse recovery algorithm, we propose a novel... 

Automatic measurement of spontaneous facial action units (AUs) defined by the facial action coding system (FACS) is a challenging problem. The recent FACS user manual defines 33 AUs to describe different facial activities and expressions. In spontaneous facial expressions, a subset of AUs are often occurred or activated at a time. Given this fact that AUs occurred sparsely over time, we propose a novel method to detect the absence and presence of AUs and estimate their intensity levels via sparse representation (SR). We use the robust principal component analysis to decompose expression from facial identity and then estimate the intensity of multiple AUs jointly using a regression model... 

Techniques available in graph theory can be applied to signals recorded from human brain. In network analysis of EEG signals, the individual nodes are EEG sensor locations and the edges correspond to functional relations between them that are extracted from EEG time series. In this paper, we study EEG-based directed functional networks in Alzheimer's disease (AD). To this end, directed connectivity matrices of 25 AD patients and 26 healthy subjects are processed and a number of meaningful graph theory metrics are studied. Our data show that functional networks of AD brains have significantly reduced global connectivity in alpha and beta bands (P < 0.05). The AD brains have significantly... 

The joint analysis of multiple datasets to extract their interdependency information has wide applications in biomedical and health informatics. In this paper, we propose an algorithm to extract joint and individual sources of multi-subject datasets by using a deflation based procedure, which is referred to as joint/individual thin independent component analysis (JI-ThICA). The proposed algorithm is based on two cost functions utilizing higher order cumulants to extract joint and individual sources. Joint sources are discriminated by fusing signals of all subjects, whereas individual sources are extracted separately for each subject. Furthermore, JI-ThICA algorithm estimates the number of...