SIZE-DEPENDENT MASS DENSITY OF NANOCRYSTALS

ALI SAFAEI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2012 NANO Vol.7 No.2

A new simple, lattice-type-sensitive model has been developed for the size-dependency of the mass density of individual elemental and compound nanocrystals. It has also been generalized for a multi-composition nanocrystal, and can be used for metallic oxides, ionic crystals and alloys. The model has been corroborated with the experimental data for the particle size-dependent apparent density (AD) of silica nanopowder.

Additional cytogenetic aberrations in chronic myeloid leukemia: a single-center experience in the Middle East

Akbar Safaei,Ahmad Monabati,Moeinadin Safavi,Ali Atashabparvar,Marzieh Hosseini 대한혈액학회 2018 Blood Research Vol.53 No.1

BackgroundAdditional cytogenetic aberrations are associated with disease progression in chronicmyeloid leukemia (CML). This study was conducted to determine the type and frequencyof these aberrations and their relationship with hematologic and molecular findings inthe Middle East. MethodsIn this retrospective study, 134 well-established cases of CML were selected from 2010to 2016. Their hematologic phase and type of fusion gene were determined. Finally, theirkaryotypes were analyzed and reported according to ISCN 2013. ResultsPatients had a mean age of 44 years. Twenty-two patients (16.4%) showed additional cytogeneticaberrations. Nine patients (6.7%) harbored a variant Philadelphia chromosome,and most were in the chronic phase. Seventeen patients (12.7%) had major and minorroute abnormalities. There was a significant relationship between additional cytogeneticaberrations and major molecular response (P=0.032). Patient survival in the group withadditional cytogenetic aberrations was significantly lower (49.7±11.1 mo) than that inthe group without additional cytogenetic aberrations (77.3±3.1 mo) (P=0.031). ConclusionThis study revealed the same frequency of additional cytogenetic aberrations in CML asfound in previous studies. Additional chromosomal aberrations led to shorter survivaland lower rates of achievement of a major molecular response.

Association of High LDH and Low Glucose Levels in Pleural Space with HER2 Expression in Non-Small Cell Lung Cancer

Ziaian, Bijan,Saberi, Ali,Ghayyoumi, Mohammad Ali,Safaei, Akbar,Ghaderi, Abbas,Mojtahedi, Zahra Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Background: Evidence shows direct link of HER2 to increased glycolysis and over production of lactate dehydrogenase (LDH). HER2 overexpression, high LDH and low glucose pleural levels are associated with poor prognosis in lung cancer. Here, their relationships were investigated. Materials and Methods: HER2 positivity was studied using immunohistochemistry in non-small cell lung cancer. Glucose and LDH levels were measured using commercial colorimetric kits. Results: Of 42 patients (29 adenocarcinoma and 13 squamous cell carcinoma), 28 (66.7%) were HER2-negative, 14 (33.3%) were HER2- positive, including 9 (21.4%) weakly stained (1+) and 5 (11.9%) moderately stained (2+) samples. The relationship between HER2 and glucose and LDH levels were tested in 20 newly diagnosed lung cancer patients who had simultaneous pleural and serum samples. Pleural and serum LDH levels were increased, and pleural glucose levels were decreased with the scale of HER2 positivity, and that the difference in glucose levels between HER2-negative group and HER2-positive patients scored at 2+ reached statistical significance (p=0.02). This latter group all had pleural glucose levels below 40 mg/dl. Conclusions: For the first time, we showed a significant association between low pleural glucose level and overexpression of HER2 in lung cancer. Further investigations are warranted to disclose the association of HER2 with low pleural glucose levels in other populations, with a larger sample size, in malignant pleural effusions caused by other types of cancer, and finally to assess employment as a screening tool for finding HER2-positive cases of lung cancer.

Numerical study on the structural performance of corrugated low yield point steel plate shear walls with circular openings

Mahdi Shariati,Shervin Safaei Faegh,Peyman Mehrabi,Seyedmasoud Bahavarnia,Yousef Zandi,Davood Rezaee Masoom,Ali Toghroli,Nguyen-Thoi Trung,Musab N.A. Salih 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.4

Corrugated steel plate shear wall (CSPSW) as an innovative lateral load resisting system provides various advantages in comparison with the flat steel plate shear wall, including remarkable in-plane and out-of-plane stiffnesses and stability, greater elastic shear buckling stress, increasing the amount of cumulative dissipated energy and maintaining efficiency even in large story drifts. Employment of low yield point (LYP) steel web plate in steel shear walls can dramatically improve their structural performance and prevent early stage instability of the panels. This paper presents a comprehensive structural performance assessment of corrugated low yield point steel plate shear walls having circular openings located in different positions. Accordingly, following experimental verification of CSPSW finite element models, several trapezoidally horizontal CSPSW (H-CSPSW) models having LYP steel web plates as well as circular openings (for ducts) perforated in various locations have been developed to explore their hysteresis behavior, cumulative dissipated energy, lateral stiffness, and ultimate strength under cyclic loading. Obtained results reveal that the rehabilitation of damaged steel shear walls using corrugated LYP steel web plate can enhance their structural performance. Furthermore, choosing a suitable location for the circular opening regarding the design purpose paves the way for the achievement of the shear wall's optimal performance.

Dimensionless Parameters Based on Motion and Experimental Validation of the Elite and Non-elite Athletes and in Two Groups of Healthy and Injured in Taekwondo Players

( Hamidreza Barnamehei ),( Mohammad Ali Safaei ) 국제태권도학회 2017 International Symposium for Taekwondo Studies Vol.2017 No.-

Purpose: Dimensionless numbers can be found in the physical concept of the phase sweep and body symmetry as a mathematical basis for comparing the relative standard of tie and later phases of the sweep parameters and symmetry parameters. Thus, the aim of this paper is to determine the dimensionless parameters of healthy and damaged in Taekwondo players based on the motion and experimental validation of elite and non-elite athletes. Methods: The inclusion and exclusion criteria as well as an orthopedic examination of the knee and lower extremities were carried out by an orthopedic surgeon following a standardized testing protocol. This study complies with the Declaration of Helsinki, and all subjects signed a written consent form approved by the university ethics committee. Results: Results obtained confirmed the theory correct. Also, according to experimental results, the dimensionless numbers for professional athletes were close to those of non-professional athletes and damaged athletes. Conclusions: The dimensionless number can be used in quantitative analysis. Moreover, the criteria for the diagnosis of healthy or injured elite and non-elite athletes describes some recovery during the treatment.

Kinematic Comparison of Two Common Different Guards in the Taekwondo Roundhouse Kick

( Hamidreza Barnamehei ),( Mohammad Ali Safaei ) 국제태권도학회 2017 International Symposium for Taekwondo Studies Vol.2017 No.-

Purpose: There are two common different guards in Taekwondo that are a concern for sport medicine researchers. The main goal of this study was to perform a kinematic analysis of two different guards when executing a Taekwondo roundhouse kick, also known as ap dollio chagi. Athletes and coaches can use these results to ameliorate general performances. Methods: Nine elite athletes of the Iranian National Taekwondo Team participated in this experimental research. A Motion Analysis System with six high speed cameras (Vicon, Oxford Metrics, UK) was used to collect the kinematics. Results: In back guard (BG) kick, Taekwondo players have negative initial velocity, because they move their trunks forward to increase their stability on the ground. In the front guard (FG), Taekwondo players do not need the initial trunk velocity, because FG has more intrinsic stability. Conclusions: Based on these findings, Taekwondo elite athletes have kinematical difference between two different guards (BG & FG) when executing a Taekwondo roundhouse kick. Also, when Taekwondo players are unstable or clash with an opponent, they should use the BG, because it provides stability and power when changing the lower limb kinematics. On the other hand, FG is agile and players can perform various techniques and tactics quickly.

Peak Kinetics and Kinematics Values of Roundhouse Kick in Elite Taekwondo Players

( Hamidreza Barnamehei ),( Mohammad Ali Safaei ) 국제태권도학회 2017 International Symposium for Taekwondo Studies Vol.2017 No.-

Purpose: Analysis of asymmetries between stable and unstable limbs have been related to an enhanced risk of injuries in athletes. Lack of balance between the agonist-antagonist segments of the knee and hip have also been linked to a greater susceptibility to injury in these joints. The aim of this paper is therefore to determine the peak kinetics and kinematics values of roundhouse kick in elite Taekwondo players. Methods: Seven elite Taekwondo athletes without significant differences between the groups in any anthropometric characteristics, age, dan (Korean: degree or level of black belt), and frequency, or time of training, volunteered for this research. Results: No bilateral difference was found in any of the variables on the knee flexion and extension assessment. Moreover, the data regarding the flexor/extensor ratio on both hip and knee joints revealed values that have been related to an increased risk of joint injury in young athletes. Conclusions: Results show that the functional demands of common competitive Taekwondo training are not necessarily bilateral strength differences induced-factors in male Taekwondo elite athletes, especially considering that similar bilateral differences were found previously in healthy non-athletes.

Taekwondo Roundhouse Kick’s Variability and Coordination of the Continuous Relative Phase in Elite Taekwondo Athletes

( Hamidreza Barnamehei ),( Mohammad Ali Safaei ) 국제태권도학회 2017 International Symposium for Taekwondo Studies Vol.2017 No.-

Purpose: This study aimed to investigate the kicking limb coordinative patterns adopted by Taekwondoin (Taekwondo practitioners) during a Taekwondo roundhouse kick (ap dollio chagi). Methods: Six Taekwondoin performed five repetitions of both kicks while kicking limb kinematics were recorded using a motion analysis system. Results: Lower-limb coordination was quantified for hip and knee flexion-extension from toe-off to kick completion using the continuous relative phase (CRP). For all trials and across all participants, CRP curve peaks and maximum and minimum were determined. During the central portion of both kicks, the CRP analysis highlighted a delayed flexion of the hip on the knee. Conclusions: Our findings suggested that there was a slight discrepancy in the pattern and variability of inter-joint coordination presented by CRP. This difference may be caused by the velocity (temporal evolution) and the normalization procedure involved in calculating CRP.

Motor learning and training strategy effect on motor control; Comparison between Taekwondo and Karate front kick (Ap Chagi and Mae Geri)

Hamidreza Barnamehei,Faezeh Khazaee,Mohammad Ali Safaei,Hadi Jabari,Neda Golfeshan,Mohammad Barnamehei,Ali Rezaei,Mohammad Reza Kharazi,Nader Naghavi 국제무예학회 2020 International Journal of Martial Arts Vol.6 No.-

The aims of the current study were first, to evaluate whether there were differences in the front kicking kinematics executed by professional Taekwondo and Karate athletics. Second, biomechanical evaluations aimed to determine the kinematic variables of effective front kicking performance between different training strategies. Sixteen elite Taekwondo and fourteen Karate athletics performed front kick. Kinematics and kinetics were recorded using a ten high-speed camera and two force plates. Taekwondo and karate groups present significant kinematic and repeatability differences, which significant differences observed in the range of motion, angular velocity, and peak values of lower limb angular positions and velocities. Although, the movement pattern of a front kick in group was similar. Based on our results, different training strategies for one movement (front kick) can change neuromuscular, motor control, and kicking efficacy. Analyzing this kind of research and comparison between two different groups that executes the same action with two different learning methods can improve the knowledge of athletics and coaches to better performance in training and learning strategies. In addition, this type of study of training strategy and motor control can reduce sports mistakes in coaching, particularly in the primary period of athletics training, and decrease injury probability.

Analysis of survival data in thalassemia patients in Shiraz, Iran

Abdolreza Rajaeefard,Mahmoud Hajipour,Hamid Reza Tabatabaee,Jafar Hassanzadeh,Shahab Rezaeian,Zahra Moradi,Mehdi Sharafi,Mohsen Shafiee,Ali Semati,Sanaz Safaei,Maryam Soltani 한국역학회 2015 Epidemiology and Health Vol.37 No.-

OBJECTIVES: The survival rate of thalassemia patients has not been conclusively established, and the factors associated with survival remain unclear. This study aimed to determine the survival rate of thalassemia among patients in southern Iran and to identify the factors associated with mortality from thalassemia. METHODS: This retrospective cohort study was conducted based on a retrospective review of the medical records of 911 beta-thalassemia patients in 2014. Data analysis was conducted using the Kaplan-Meier method and Cox regression analysis. RESULTS: Overall, 212 patients (23.3%) died, and 26.8% had thalassemia intermedia. The 20-year, 40-year, and 60-year survival rates were 85%, 63%, and 54%, respectively. Both crude and adjusted analyses found that education, marital status, ferritin levels, and comorbidities were related to mortality. CONCLUSIONS: Sociodemographic and hematological factors were found to be significantly associated with the survival rate of thalassemia. Addressing these factors may help healthcare providers and physicians to provide the best possible care and to improve the survival rate.