Dehydroepiandrosterone Sulfate as a Risk Factor for Premature Myocardial Infarction: A Comparative Study

Mohammad Shojaie,Armin Abtahian,Armin Abtahian,Mohamed Amin Ghobadifar,Azadeh Esmail Pour,Armin Akbarzadeh 대한가정의학회 2015 Korean Journal of Family Medicine Vol.36 No.1

Ba ckground: This study aimed to evaluate some of the major risk factors of myocardial infarction including dehydroepiandrosterone sulfate in patients with premature myocardial infarction (age <50 years old) and myocardial infarction (age ≥50 years). Me thods: This is a parallel case-control study on 50 premature myocardial infarction patients and 50 myocardial infarction patients. We also recruited 50 matched participants for each of the two groups. Patients and their control groups were assessed for dehydroepiandrosterone sulfate serum level, diabetes mellitus, hyperlipidemia, hypertriglyceridemia, and hypertension. In addition, family history of cardiovascular disease and current smoking was recorded. Univariate and multivariate logistic regression analyses were performed to evaluate predictors of premature myocardial infarction and myocardial infarction. Re sults: No significant differences were observed between the demographic data of patients and their controls. The dehydroepiandrosterone sulfate serum level was significantly higher in patients with premature myocardial infarction compared with controls. Multivariate logistic regression analysis revealed only serum dehydroepiandrosterone sulfate dehydroepiandrosterone sulfate level to be significantly associated with premature myocardial infarction (odds ratio, 2.65; 95% confidence interval, 1.44 to 4.877; P = 0.002). Additionally, hypertension was found to be associated with myocardial infarction. Co nclusion: Higher levels of serum dehydroepiandrosterone sulfate level are associated with premature myocardial infarction but not with myocardial infarction, and this association is independent of the effects of other risk factors.

Microstructural, Mechanical and Corrosion Properties of AZ91 Magnesium Alloy Processed by a Severe Plastic Deformation Method of Hydrostatic Cyclic Expansion Extrusion

Armin Siahsarani,Farshad Samadpour,Mohammad Hossein Mortazavi,Ghader Faraji 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

This research investigates the microstructural evolution, mechanical properties, and corrosion behavior of AZ91 magnesiumalloy after the process of hydrostatic cyclic expansion extrusion (HCEE) at elevated temperature. The HCEE process is ableto produce long length ultrafine-grained rods by applying high hydrostatic pressure. The results showed that ultrafine-grainedmicrostructure appears after the consecutive passes of the process, which led to the higher hardness and strength with anincreased elongation to failure in the processed rods at room temperature. The ultimate tensile strength and elongation tofailure of the processed rod after two cycles of the HCEE increased more than 2 and 2.6 times, respectively. Moreover, anincrease in hardness was more than 100% after the second cycle of the process and its distribution was more uniform. Furthermore,the ultrafine-grained microstructure after the HCEE resulted in the movement of potentiodynamic polarizationderived curves to higher values of corrosion potential (Ecorr) and lower current density (Icorr), which shows the capabilityof the HCEE process in improving the corrosion resistance of AZ91 magnesium alloy rods. These increases in corrosionresistance were further indicated by the Nyquist diagram derived from the electrochemical impedance spectroscopy scanningand evolved hydrogen amount after 208 h of immersion in 3.5% NaCl solution. The novel HCEE process shows furtherits capability in producing long length ultrafine-grained rods with superior mechanical and corrosion properties rather thanother severe plastic deformation techniques.

Quantitative-fuzzy Controller Design for Multivariable Systems with Uncertainty

Mohammad Reza Gharib,Armin Daneshvar 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.6

This work serves as a pioneer contribution in terms of application of Quantitative Feedback Theory(QFT) methodology and fuzzy logic method to design a controller for MIMO systems. Due to the presence of uncertainty in multivariable dynamic systems, the application of robust control methods for achieving high accuracy in tracking is inevitable. On the other hand, application of QFT to MIMO uncertain systems still remains to be one of the most difficult control problems for engineers. In this paper, authors attempt to simplify the MIMO control problem by proposing a new algorithm which joins QFT and fuzzy techniques. In order to illustrate the utility of the proposed algorithm, its application on a two degree of freedom link robot manipulator is depicted. Initially, a QFT controller is designed for each link to overcome the track and disturbance rejection problems. Then, a bi-level tuned PDfuzzy controller is employed as one strategy for curbing probable errors in the previous controller. The controller design was carried in the following stages; first, a linear PD controller independently applied to each actuator. Then, fuzzy rules were developed to design a fuzzy PD controller. Fuzzy controller normalizing parameters were regulated according to maximum PD control errors. In the second stage, named nonlinear tuning, other parameters of the fuzzy controller were tuned using genetic algorithms. Finally,nonlinear simulations of arbitrary path tracking shows that the proposed controller has a consistent tracking ability,and also it can clearly be seen that the mentioned approach is precise and very simple in comparison to other MIMO control techniques.

A Multi-Stage Stochastic Mixed-Integer Linear Programming to Design an Integrated Production-Distribution Network under Stochastic Demands

Mohammad Derakhshi,Seyed Taghi Akhavan Niaki,Seyed Armin Akhavan Niaki 대한산업공학회 2018 Industrial Engineeering & Management Systems Vol.17 No.3

Supply chain management has gained much interest from researchers and practitioners in recent years. Proposing practical models that efficiently address different aspects of the supply chain is a difficult challenge. This research investigates an integrated production-distribution supply chain problem. The developed model incorporates parties with a specified number of processes to obtain raw materials from the suppliers in order to convert them to semi and final products. These products are then distributed through warehouses to end-distributors having uncertain demands. This uncertainty is captured as a dynamic stochastic data process during the planning horizon and is modeled into a multi-stage stochastic mixed integer linear program using a scenario tree approach. For large-size instances, a hybrid exact-approximate algorithm is proposed, where its effectiveness is assessed via several numerical cases. Furthermore, the model is generalized to its bi-objective version by considering the accessibility of the products based on the safety stock policy of the companies involved. In the end, an existing algorithm is combined with the ε-constraint method to obtain an approximate Pareto front.

Absence of Correlation between Changes in the Number of Endothelial Progenitor Cell Subsets

Armin Attar,Kamran Aghasadeghi,Mohammad Ebrahim Parsanezhad,Bahia Namavar Jahromi,Mojtaba Habibagahi 대한심장학회 2015 Korean Circulation Journal Vol.45 No.4

Background and Objectives: Previously, various methodologies were used to enumerate the endothelial progenitor cells (EPCs). We now know that these methodologies enumerate at least three different EPC subsets: circulating angiogenic cells (CACs), colony-forming unit endothelial cells (CFU-ECs), and endothelial colony-forming cells (ECFCs). It is not clear whether there is a correlation between changes in the number of these subsets. The aim of the current study is to find an answer to this question. Materials and Methods: The number of all EPC subsets was quantified in the peripheral blood of nine pregnant women in their first and third trimesters of pregnancy. We enumerated 14 cell populations by quantitative flow-cytometry using various combinations of the markers, CD34, CD133, CD309, and CD45, to cover most of the reported phenotypes of CACs and ECFCs. Culturing technique was used to enumerate the CFU-ECs. Changes in the number of cells were calculated by subtracting the number of cells in the first trimester peripheral blood from the number of cells in the third trimester peripheral blood, and correlations between these changes were analyzed. Results: The number of CFU-ECs did not correlate with the number of ECFCs and CACs. Also, CACs and ECFCs showed independent behaviors. However, the number of CACs showed a strong correlation with the number of CD133+CD309+ cells (p=0.001) and a moderate correlation with the number of CD34+CD309+ cells (p=0.042). Also, the number of ECFCs was correlated with the number of CD309+CD45- cells (p=0.029) and CD34+CD45- cells (p=0.03). Conclusion: Our study showed that the three commonly used methods for quantifying EPC subsets represent different cells with independent behaviors. Also, any study that measured the number of EPCs using the flow cytometry method with a marker combination that lacks CD309 may be inaccurate.

Prediction of Pile Settlement based on Cone Penetration Test Results: An ANN Approach

Mohammad Hassan Baziar,Alireza Saeedi Azizkandi,Armin Kashkooli 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.1

Several theoretical and experimental methods are available to estimate pile settlement. Due to difficulties for obtaining undisturbedsamples, many of these methods have been focused on in-situ tests. The cone penetration test is one of the most effective in-situ testsbecause of its geometrical analogy with the piles as well as presenting continuous results along the depth. In this study, 1300 recordedsettlement data from 101 pile loading tests with the CPT results were collected. Then Artificial Neural Network analyses (ANN)were conducted to obtain the best model for the prediction of pile settlement. The relative importance of input parameters has beenevaluated using senility analysis. Accuracy predictions of the proposed model, along with other classic methods, were compared withthe recorded values from the loading tests with the aid of different statistical parameters. This comparison indicated the superiority ofthe proposed model over previous methods. A parametric study has also been performed for the input parameters to study theconsistency of the suggested model.

STATIC ANALYSIS OF FUNCTIONALLY GRADED PIEZOELECTRIC BEAMS UNDER THERMAL LOADS BY THE HOMOTOPY PERTURBATION METHOD

Ahad Armin,Mostafa Abbasi,Iman Shafieenejad,Mohammad Reza Eslami 한국소음진동공학회 2008 한국소음진동공학회 국제학술대회논문집 Vol.2008 No.7

bKash: Transforming Bangladesh

Shegufta Armin Ahsan,Mohammad Adnan Rahman,Prottay Hasan Academy of Asian Business (AAB) 2020 Academy of Asian Business Review Vol.6 No.2

At the start of 2010, Bangladesh was a country where storing money under the mattress was commonplace for over half of its 160 million residents. The financial inclusion rate was one of the worst in the world, with conventional banking failing to reach many who needed security the most. However, by the turn of the decade, over 70 million Bangladeshis would find financial strength in the palm of their hands. The rise of mobile financial services (MFS) has brought unprecedented economic and social development, and much of that success story is centered on one company: bKash. Aptly named as a play on the Bangla word for ‘prosperity’, bKash was built on the idea of providing a financial foothold to the unbanked, and today bKash holds over 80% share in the MFS market. This remarkable success was forged through keen consumer insight, recognition of market needs, key strategic partnerships and stellar organizational management. bKash recognized the ubiquity of the mobile phone in Bangladesh and its potential to democratize access to banking, and developed an easy-to-use, (initially) low-tech solution to a mass scale problem. Ingenuity in service design helped create an easily adopted customer-oriented product. By partnering with key organizations and telecom operators, bKash could effectively reach the remotest parts of the country. Today, from their sophisticated, AI-powered control center at the capital city Dhaka, bKash oversees the economic activity going in and out of the e-wallets of its 40 million users, analyzing economic data at any of the country’s administrative divisions. The company has seen staggering growth and in 2018 processed BDT 7 bn. per day. Millions of customers sleep easier now, knowing their money is safe under bKash’s digital mattress.

Immunogenicity of decellularized extracellular matrix scaffolds: a bottleneck in tissue engineering and regenerative medicine

Mohammadreza Kasravi,Armin Ahmadi,Amirhesam Babajani,Radman Mazloomnejad,Mohammad Reza Hatamnejad,Siavash Shariatzadeh,Soheyl Bahrami,Hassan Niknejad 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Tissue-engineered decellularized extracellular matrix (ECM) scaffolds hold great potential to address the donor shortage as well as immunologic rejection attributed to cells in conventional tissue/organ transplantation. Decellularization, as the key process in manufacturing ECM scaffolds, removes immunogen cell materials and significantly alleviates the immunogenicity and biocompatibility of derived scaffolds. However, the application of these bioscaffolds still confronts major immunologic challenges. This review discusses the interplay between damage-associated molecular patterns (DAMPs) and antigens as the main inducers of innate and adaptive immunity to aid in manufacturing biocompatible grafts with desirable immunogenicity. It also appraises the impact of various decellularization methodologies (i.e., apoptosis-assisted techniques) on provoking immune responses that participate in rejecting allogenic and xenogeneic decellularized scaffolds. In addition, the key research findings regarding the contribution of ECM alterations, cytotoxicity issues, graft sourcing, and implantation site to the immunogenicity of decellularized tissues/organs are comprehensively considered. Finally, it discusses practical solutions to overcome immunogenicity, including antigen masking by crosslinking, sterilization optimization, and antigen removal techniques such as selective antigen removal and sequential antigen solubilization.

Implementation of Proteomics for Cancer Research: Past, Present, and Future

Karimi, Parisa,Shahrokni, Armin,Nezami Ranjbar, Mohammad R. Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Cancer is the leading cause of the death, accounts for about 13% of all annual deaths worldwide. Many different fields of science are collaborating together studying cancer to improve our knowledge of this lethal disease, and find better solutions for diagnosis and treatment. Proteomics is one of the most recent and rapidly growing areas in molecular biology that helps understanding cancer from an omics data analysis point of view. The human proteome project was officially initiated in 2008. Proteomics enables the scientists to interrogate a variety of biospecimens for their protein contents and measure the concentrations of these proteins. Current necessary equipment and technologies for cancer proteomics are mass spectrometry, protein microarrays, nanotechnology and bioinformatics. In this paper, we provide a brief review on proteomics and its application in cancer research. After a brief introduction including its definition, we summarize the history of major previous work conducted by researchers, followed by an overview on the role of proteomics in cancer studies. We also provide a list of different utilities in cancer proteomics and investigate their advantages and shortcomings from theoretical and practical angles. Finally, we explore some of the main challenges and conclude the paper with future directions in this field.