Time delay study for semi-active control of coupled adjacent structures using MR damper

Javad Katebi,Samira Mohammady Zadeh 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.6

The pounding phenomenon in adjacent structures happens in severing earthquakes that can cause great damages. Connecting neighboring structures with active and semi-active control devices is an effective method to avoid mutual colliding between neighboring buildings. One of the most important issues in control systems is applying online control force. There will be a time delay if the prose of producing control force does not perform on time. This paper proposed a time-delay compensation method in coupled structures control, with semi-active Magnetorheological (MR) damper. This method based on Newmark’s integration is adopted to mitigate the time-delay effect. In this study, Lyapunov's direct approach is employed to compute demanded voltage for MR dampers. Using Lyapunov's direct algorithm guarantees the system stability to design a controller based on feedback. Because of the strong nonlinearity of MR dampers, the equation of motion of coupled structures becomes an involved equation, and it is impossible to solve it with the common time step methods. In present paper modified Newmark-Beta integration based on the instantaneous optimal control algorithm, used to solve the involved equation. In this method, the response of a coupled system estimated base on optimal control force. Two MDOF structures with different degrees of freedom are finally considered as a numeric example. The numerical results show, the Newmark compensation is an efficient method to decrease the negative effect of time delay in coupled systems; furthermore, instantaneous optimal control algorithm can estimate the response of structures suitable.

Comparison of the Effectiveness of Polyethylenimine, Polyamidoamine and Chitosan in Transferring Plasmid Encoding Interleukin-12 Gene into Hepatocytes

Ali Dehshahri,Samira Hossaini Alhashemi,Akram Jamshidzadeh,Zahra Sabahi,Soliman Mohammadi Samani,Hossein Sadeghpour,Erfaneh Mohazabieh,Mahin Fadaei 한국고분자학회 2013 Macromolecular Research Vol.21 No.12

Interleukin-12 (IL-12) has been proposed for cancer immunotherapy due to its versatile antitumor and antiangiogenesis effects. Although cancer immunotherapy through systemic administration of IL-12 has shown antitumor effects in tumor-bearing mice, broad application of recombinant IL-12 protein has been limited by its cytotoxicity. Therefore, the use of various polycationic polymers such as polyethylenimine (PEI), polyamidoamine (PAMAM) and chitosan has been considered as an effective strategy to transfer plasmid encoding IL-12 gene into cells. In this investigation, polyplexes (polymer/pDNA complexes) were prepared using PEI, PAMAM and chitosan at different N/P ratios and their ability in transferring plasmid encoding IL-12 gene was evaluated. Furthermore,these polyplexes were characterized and compared with regarding their cytotoxicity, DNA condensation ability, particle size, zeta potential, buffering capacity and pDNA protection against enzyme degradation. The results revealed that the polyplexes formulated with 25 kDa PEI and chitosan had the highest transfection efficiencies. The highest level of IL-12 gene expression was achieved by the nanoparticles prepared by 25 kDa PEI where they could increase the level of gene expression up to 12 times compared to that of naked plasmid encoding IL-12 gene. These results suggest that 25 kDa PEI and chitosan are the best candidates for adding targeting ligands into their structures in order to create a liver targeting gene delivery system.

Study of probiotic and simvastatin additive effect on Helicobacter pylori eradication rate

Abazar Parsi,Maryam Biuseh,Samira Mohammadi,Eskandar Hajiani,Seyed Jalal Hashemi,Hooman Saeidian,Mehdi Biuseh 소화기인터벤션의학회 2019 Gastrointestinal Intervention Vol.8 No.4

Background: Helicobacter pylori infection is a major cause of chronic gastritis, peptic, mucosa associated lymphoid tissueMisdiagnosed as lymphoma and gastric cancer. The eradication rate of H. pylori with standard treatments are decreasing worldwide. The aim of this study was to determine the efficacy of adding simvastatin or probiotic as adjuvant to quadruple therapy on the eradication of H. pylori. Methods: This randomized clinical trial study was conducted on 160 patients with H. pylori. The patients were randomly divided in to 4 groups. The group 1: standard quadruple eradication regimen consisting of two antibiotics (clarithromycin 500 mg and amoxicillin 1 g, all twice per day), a proton pump inhibitor (pantoprazole 40 mg twice daily), Bismuth (120 mg twice daily) with placebo (daily), group 2: standard regimen plus probiotic (daily east 250 mg), group 3: standard regimen supplemented with simvastatin (10 mg daily) and group 4: standard regimen plus simvastatin (20 mg daily) for 14 days was given. The Eradication was determined by stool antigen test at least 1 month after treatment. Results: The risk ratio of eradication of the infection in the simvastatin group 10 mg and simvastatin 20 mg was 0.375 and 0.625 times in compare with the placebo group, indicating a negative effect of simvastatin 10 and 20 mg on the treatment of H. pylori infection, this relationship is not statistically significant (P > 0.05). Conclusion: Due to the high efficacy of simvastatin in H. pylori eradication, further studies are needed to evaluate the use of statins as adjunctive to improve the eradication rate.

Study of probiotic and simvastatin additive effect on Helicobacter pylori eradication rate

Abazar Parsi,Maryam Biuseh,Samira Mohammadi,Eskandar Hajiani,Seyed Jalal Hashemi,Hooman Saeidian,Mehdi Biuseh 소화기인터벤션의학회 2019 International journal of gastrointestinal interven Vol.8 No.4

Background: Helicobacter pylori infection is a major cause of chronic gastritis, peptic, mucosa associated lymphoid tissueMisdiagnosed as lymphoma and gastric cancer. The eradication rate of H. pylori with standard treatments are decreasing worldwide. The aim of this study was to determine the efficacy of adding simvastatin or probiotic as adjuvant to quadruple therapy on the eradication of H. pylori. Methods: This randomized clinical trial study was conducted on 160 patients with H. pylori. The patients were randomly divided in to 4 groups. The group 1: standard quadruple eradication regimen consisting of two antibiotics (clarithromycin 500 mg and amoxicillin 1 g, all twice per day), a proton pump inhibitor (pantoprazole 40 mg twice daily), Bismuth (120 mg twice daily) with placebo (daily), group 2: standard regimen plus probiotic (daily east 250 mg), group 3: standard regimen supplemented with simvastatin (10 mg daily) and group 4: standard regimen plus simvastatin (20 mg daily) for 14 days was given. The Eradication was determined by stool antigen test at least 1 month after treatment. Results: The risk ratio of eradication of the infection in the simvastatin group 10 mg and simvastatin 20 mg was 0.375 and 0.625 times in compare with the placebo group, indicating a negative effect of simvastatin 10 and 20 mg on the treatment of H. pylori infection, this relationship is not statistically significant (P > 0.05). Conclusion: Due to the high efficacy of simvastatin in H. pylori eradication, further studies are needed to evaluate the use of statins as adjunctive to improve the eradication rate.

Reducing Irrational Beliefs and Pain Severity in Patients Suffering from Non-Cardiac Chest Pain (NCCP): A Comparison of Relaxation Training and Metaphor Therapy

( Mostafa Bahremand ),( Gholamreza Moradi ),( Mozhgan Saeidi ),( Samira Mohammadi ),( Saeid Komasi ) 대한통증학회 2015 The Korean Journal of Pain Vol.28 No.2

Background: Patients suffering from non-cardiac chest pain (NCCP) can interpret their chest pain wrongly despite having received a correct diagnosis. The objective of this study was to compare the efficacy of the relaxation method with metaphor therapy for reducing irrational beliefs and pain severity in patients with NCCP. Methods: Using a randomized controlled trial, 33 participants were randomly divided into a relaxation training group (n= 13), a metaphor therapy group (n = 10), and a control group (n = 10), and were studied for 4 weeks. The two tools used in this research were the Brief Pain Inventory (BPI) index for determining the degree of pain and the short version of the Jones Irrational Belief Test. Metaphor therapy and a relaxation technique based on Ost’s treatment were used as the interventions. The collected data were analyzed with a multivariate analysis of covariance (MANCOVA), a Chi-square test, and the Bonferroni procedure of post-hoc analysis. Results: The relaxation training method was significantly more effective than both metaphor therapy and the lack of treatment in reducing the patients’ beliefs of hopelessness in the face of changes and emotional irresponsibility, as well as the pain severity. Metaphor therapy was not effective on any of these factors. In fact, the results did not support the effectiveness of metaphor therapy. Conclusions: Regarding the effectiveness of the relaxation method as compared with metaphor therapy and the lack of treatment in the control group, this study suggests that relaxation should be paid greater attention as a method for improving the status of patients. In addition, more studies are needed to determine the effectiveness of metaphor therapy in this area. (Korean J Pain 2015; 28: 88-95)