Characteristics of Nanostructured Powder Mixture Produced by Ball Milling

Azimi Hossein,Ahmadi Eltefat,Hadavi S.M.Mehdi 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

In the present work, the influence of the ball-milling time, milling atmosphere and weight ratio of ball to powder on characteristics of was studied. Results show that, the grain sizes of the and CuO in the ball-milled powder mixture were significantly decreased with increasing the milling time. Those of each oxide ball-milled in Argon and Hexane atmosphere for 30 and 20 hour were about 98 and 84 nm, respectively. After milling of 20 hour in Hexane as PCA, the powder had a homogeneously mixed structure and the average size of powders was determined to about 230nm.

Outcome Measures of Functionality, Social Interaction, and Pain in Patients with Cervical Spondylotic Myelopathy: A Validation Study for the Iranian Version of the Copenhagen Neck Functional Disability Scale

Hossein Nayeb Aghaei,Parisa Azimi,Sohrab Shahzadi,Shirzad Azhari,Hassan Reza Mohammadi,Pooyan Alizadeh,Ali Montazeri 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.6

Study Design: Cross-sectional. Purpose: To translate and validate the Iranian version of the Copenhagen Neck Functional Disability Scale (CNFDS). Overview of Literature: Instruments measuring patient-reported outcomes should satisfy certain psychometric properties. Methods: Ninety-three cases of cervical spondylotic myelopathy were entered into the study and completed the CNFDS pre and postoperatively at the 6 month follow-up. The modified Japanese Orthopedic Association Score was also completed. The internal consistency, test-retest, convergent validity, construct validity (item scale correlation), and responsiveness to change were assessed. Results: Mean age of the patients was 54.3 years (standard deviation, 8.9). The Cronbach α coefficient was satisfactory (α=0.84). Test-retest reliability as assessed by the intraclass correlation coefficient analysis was 0.95 (95% confidence interval, 0.92–0.98). The modified Japanese Orthopedic Association score correlated strongly with the CNFDS score, lending support to its good convergent validity (r =−0.80; p <0.001). Additionally, the correlation of each item with its hypothesized domain on the CNFDS was acceptable, suggesting that the items had a substantial relationship with their own domains. These results also indicate that the instrument was responsive to change (p <0.0001). Conclusions: The findings suggest that the Iranian version of the CNFDS is a valid measure to assess functionality, social interaction, and pain among patients with cervical spondylotic myelopathy.

Role of the Self-Administered, Self-Reported History Questionnaire to Identify Types of Lumbar Spinal Stenosis: A Sensitivity Analysis

Hossein Nayeb Aghaei,Parisa Azimi,Sohrab Shahzadi,Shirzad Azhari,Hassan Reza Mohammadi 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.5

Study Design: Case-control design. Purpose: To evaluate the role of the self-administered, self-reported history questionnaire (SSHQ) in identifying types of lumbar spinal stenosis (LSS). Overview of Literature: Diagnosis of types of LSS is controversial. Methods: A total of 235 patients with LSS were asked to respond to the SSHQ. All of these patients recovered following surgical treatment. The classification of LSS patients was based on history, physical examinations, and imaging studies. It is considered to be the gold standard. Radicular and neurogenic claudication types of LSS were based on the SSHQ developed by Konno et al. Two categories of LSS were determined based on the SSHQ tool and gold standard. Finally, a sensitivity analysis was carried out to evaluate the diagnostic value of the SSHQ. Results: The mean age of patients was 59.4 years. According to the criteria for gold standard, patients were diagnosed with the radicular type (n=103), and neurogenic claudication type (n=132). The questionnaire had desirable sensitivity, specificity, and accuracy in categorizing the two types of LSS: 97.8%, 66.6%, and 96.8% for the radicular type, and 97.0%, 80.0%, and 95.7% for the neurogenic claudication type. Conclusions: Our findings indicate that the SSHQ is a reliable and a valid measure and it may be a clinical diagnosis support tool for identifying patients with two types of LSS.

Time - and Concentration - Dependent Effects of Resveratrol on miR 15a and miR16-1 Expression and Apoptosis in the CCRF-CEM Acute Lymphoblastic Leukemia Cell Line

Azimi, Ako,Hagh, Majid Farshdousti,Talebi, Mehdi,Yousefi, Bahman,feizi, Abbas Ali Hossein pour,Baradaran, Behzad,Movassaghpour, Ali Akbar,Shamsasenjan, Karim,Khanzedeh, Taghi,Ghaderi, Abdol Hasan,Heyd Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

Background: Chemotherapy is one of the common approaches in treatment of cancers, especially leukemia. However, drug resistance phenomena reduce the likelihood of treatment success. Resveratrol is a herbal compound which through complicated processes makes some selected cells sensitive to treatment and induction of apoptosis. In the present study, the effects of resveratrol on the expression of miR 15a and miR16-1 and apoptosis in the CCRF-CEM cell line were investigated. Materials and Methods: The CCRF-CEM cell line was cultured under standard conditions and changes in miR 15a and miR 16-1 expression were analyzed by real time-PCR technique, with attention to reveratrol dose and time dependence. Also, apoptosis is evaluated by flow cytometry using annexin V and PI. Results: CCRF-CEM cells underwent dose-dependent apoptotic cell death in response to resveratrol. MiR 15a and miR 16-1 expression was up-regulated after 24 and 48 hours resveratrol treatment (p<0.05). Conclusions: The results of our study indicate that resveratrol induces apoptosis in a time and dose-dependent manner in CCRF-CEM cells. Also, increased expression level of miR 16-1 and miR 15a by means of resveratrol in CCRF-CEM cells might have a role in apoptosis induction and predisposition. According to our results resveratrol can be regarded as a dietary supplement to improve efficacy of anti-leukemia therapies.

A Review on the Use of Artificial Intelligence in Spinal Diseases

Azimi Parisa,Yazdanian Taravat,Benzel Edward C.,Aghaei Hossein Nayeb,Azhari Shirzad,Sadeghi Sohrab,Montazeri Ali 대한척추외과학회 2020 Asian Spine Journal Vol.14 No.4

Artificial neural networks (ANNs) have been used in a wide variety of real-world applications and it emerges as a promising field across various branches of medicine. This review aims to identify the role of ANNs in spinal diseases. Literature were searched from electronic databases of Scopus and Medline from 1993 to 2020 with English publications reported on the application of ANNs in spinal diseases. The search strategy was set as the combinations of the following keywords: “artificial neural networks,” “spine,” “back pain,” “prognosis,” “grading,” “classification,” “prediction,” “segmentation,” “biomechanics,” “deep learning,” and “imaging.” The main findings of the included studies were summarized, with an emphasis on the recent advances in spinal diseases and its application in the diagnostic and prognostic procedures. According to the search strategy, a set of 3,653 articles were retrieved from Medline and Scopus databases. After careful evaluation of the abstracts, the full texts of 89 eligible papers were further examined, of which 79 articles satisfied the inclusion criteria of this review. Our review indicates several applications of ANNs in the management of spinal diseases including (1) diagnosis and assessment of spinal disease progression in the patients with low back pain, perioperative complications, and readmission rate following spine surgery; (2) enhancement of the clinically relevant information extracted from radiographic images to predict Pfirrmann grades, Modic changes, and spinal stenosis grades on magnetic resonance images automatically; (3) prediction of outcomes in lumbar spinal stenosis, lumbar disc herniation and patient-reported outcomes in lumbar fusion surgery, and preoperative planning and intraoperative assistance; and (4) its application in the biomechanical assessment of spinal diseases. The evidence suggests that ANNs can be successfully used for optimizing the diagnosis, prognosis and outcome prediction in spinal diseases. Therefore, incorporation of ANNs into spine clinical practice may improve clinical decision making.

An Outcome Measure of Functionality and Pain in Patients with Low Back Disorder: A Validation Study of the Iranian version of Low Back Outcome Score

Parisa Azimi,Hossein Nayeb Aghaei,Shirzad Azhari,Sohrab Shazadi,Hamid Khayat Kashany,Hassan Reza Mohammadi,Ali Montazeri 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.4

Study Design: Cross-sectional study. Purpose: This study aimed to cross-culturally translate and validate the low back outcome score (LBOS) in Iran. Overview of Literature: Lumbar disc hernia (LDH) is the most common diagnoses of low back pain and imposes a heavy burden on both individual and society. Instruments measuring patient reported outcomes should satisfy cetain psychometric properties. Methods: The translation and cross-cultural adaptation of the original questionnaire was performed using Beaton’s guideline. A total of 163 patients with LDH were asked to respond to the questionnaire at three points in time: preoperative and twice within 1-week interval after surgery assessments. The Oswestry disabilty index (ODI) was also completed. The internal consistency, test-retest, convergent validity, and responsiveness to change were assessed. Responsiveness to change also was assessed comparing patients’ pre- and postoperative scores. Results: The mean age of the cohort was 49.8 years (standard deviation=10.1). The Cronbach’s alpha coefficients for the LBOS at preoperative and postoperative assessments ranged from 0.77 to 0.79, indicating good internal consistency. Test-retest reliability as performed by intraclass correlation coefficient was found to be 0.82 (0.62–0.91). The instrument discriminated well between subgroups of patients who differed in the Finneson-Cooper score. The ODI correlated strongly with the LBOS score, lending support to its good convergent validity (r =–0.83; p <0.001). Further analysis also indicated that the questionnaire was responsive to change (p <0.001). Conclusions: The Iranian version of LBOS performed well and the findings suggest that it is a valid measure of back pain treatment evaluation among LDH patients.

Cut-off Value for Body Mass Index in Predicting Surgical Success in Patients with Lumbar Spinal Canal Stenosis

Parisa Azimi,Taravat Yazdanian,Sohrab Shahzadi,Edward C. Benzel,Shirzad Azhari,Hossein Nayeb Aghaei,Ali Montazeri 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.6

Study Design: Case-control. Purpose: To determine optimal cut-off value for body mass index (BMI) in predicting surgical success in patients with lumbar spinal canal stenosis (LSCS). Overview of Literature: BMI is an essential variable in the assessment of patients with LSCS. Methods: We conducted a prospective study with obese and non-obese LSCS surgical patients and analyzed data on age, sex, duration of symptoms, walking distance, morphologic grade of stenosis, BMI, postoperative complications, and functional disability. Obesity was defined as BMI of ≥30 kg/m2. Patients completed the Oswestry Disability Index (ODI) questionnaire before surgery and 2 years after surgery. Surgical success was defined as ≥30% improvement from the baseline ODI score. Receiver operating characteristic (ROC) analysis was used to estimate the optimal cut-off values of BMI to predict surgical success. In addition, correlation was assessed between BMI and stenosis grade based on morphology as defined by Schizas and colleague in total, 189 patients were eligible to enter the study. Results: Mean age of patients was 61.5±9.6 years. Mean follow-up was 36±12 months. Most patients (88.4%) were classified with grades C (severe stenosis) and D (extreme stenosis). Post-surgical success was 85.7% at the 2-year follow-up. A weak correlation was observed between morphologic grade of stenosis and BMI. Rates of postoperative complications were similar between patients who were obese and those who were non-obese. Both cohorts had similar degree of improvement in the ODI at the 2-year followup. However, patients who were non-obese presented significantly higher surgical success than those who were obese. In ROC curve analysis, a cut-off value of ≤29.1 kg/m2 for BMI in patients with LSCS was suggestive of surgical success, with 81.1% sensitivity and 82.2% specificity (area under the curve, 0.857; 95% confidence interval, 0.788–0.927). Conclusion: This study showed that the BMI can be considered a parameter for predicting surgical success in patients with LSCS and can be useful in clinical practice.

Robust Multi Objective H₂/H<SUB>∞</SUB> Control of MIMO Nonlinear Uncertain systems via T-S Fuzzy Model

Vahid Azimi,Peyman Akhlaghi,Mohammad Hossein Kazemi 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

This paper describes robust H₂/H∞ multi-objective state feedback controller for nonlinear uncertain systems. To apply the H₂/H∞ multi-objective state feedback method, the nonlinear dynamics is represented by a T-S fuzzy model. First, uncertain parameters and Quantification of uncertainty on physical parameters is defined by affine parameter-dependent systems method. Next, the Takagi and Sugeno"s fuzzy linear model is utilized to approximate uncertain nonlinear systems. Then, some states (error of tracking) are augmented to the system in order to improve tracking control. Finally, based on fuzzy linear model with augmented state, a H₂/H∞ multi-objective state feedback controller is developed to achieve the robustness design of nonlinear uncertain systems. LMI (Linear Matrix Inequality) method and PDC (Parallel Distributed Compensation) are used to design the controller for the whole system. The results show that the proposed method can effectively meet the performance requirements like robustness, disturbance rejection and tracking for the 3-phase permanent magnet synchronous motor (PMSM).

Simulation of Draught Force During Chisel Ploughing Using Discrete Element Method

Rahmanian-Koushkaki Hossein,Mahmoodi-Eshkaftaki Mahmood,Azimi-Nejadian Hadi 한국농업기계학회 2022 바이오시스템공학 Vol.47 No.2

Purpose Chiseling is an essential tillage practice in conservation tillage systems. One of the main methods in soil–tool behaviour analysis of a tillage implement like chisel plough is numerical simulation. The discrete element method (DEM) is one of the most powerful techniques for this purpose. In this study, draught force of a mounted type chisel plough with nine C-shanks was predicted using DEM when working in a clay-loam soil. Methods The effects of forward speed (3, 4 and 5 km h-1) and working depth (10, 15 and 20 cm) on the draught force were investigated. The available commercial EDEM software was used for the simulations, and combination of hysteric spring with cohesion/adhesion forces was employed as the contact model. Results The numerical results were compared to experimental trials and well-known analytical model (McKyes and Ali) results. The experimental results were obtained to be within 3.24–34.9% and 9–35% larger than DEM-simulated and analytical calculated draught, respectively. A regression equation was developed in accordance with the simulated data. According to the values of statistical parameters (R2, RMSE and MRD), the established model had good accuracy. Conclusions From the simulations, it was concluded that draught force increased with an increase in working depth and forward speed. Also, it was found that the DEM results had higher accuracy than analytical results.

Carbon dioxide absorption by Ammonia-promoted aqueous triethanolamine solution in a packed bed

Rashidi Hamed,Azimi Hossein,Rasouli Parvaneh 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.9

CO2 absorption by ammonia added triethanolamine aqueous solution as a promoter was investigated in terms of absorption percentage (AP), overall volumetric mass transfer coefficient (KGae), and molar flux (NA) in a packed column. Three variables of ammonia concentration (0–5 wt%), Triethanolamine concentration (10–30 wt%), and gas flow rate (1,500–2,500 ml/min) were considered as significant variables in absorption performance. Effect of these variables and their interactions were inspected using the three level factorial response-surface method. Statistical analysis of the results showed that an ammonia concentration with 72.99%, 71.83, and 81.12% has the greatest effect on AP%, NA, and KGae, respectively. Then, gas flow rate with 5.27% and 3.90%, had a great effect on AP% and KGae, respectively. Finally, the optimal operating conditions were determined to maximize the responses. Under optimal operating conditions, the maximum values for AP%, KGae, and NA were 98.94%, 0.202 kmol/h·m3·kPa, and 3.901 kmol/m2·h, respectively. Thus, adding ammonia to triethanolamine considerably improves the mass transfer performance of solvent.