Evaluation of modified nonlinear dynamic and static analyses for seismic behavior of steel moment-resisting frames

With the progresses made in the field of structural and earthquake engineering and with more exact knowledge gained on seismic behavior of structures, earthquake engineering and various structures have advanced a great deal and various types of analytical methods have been developed for the assessment of structures. Dynamic analysis methods are aimed at determining the accurate behavior of structures and static analysis approaches are employed to predict structural behavior for engineering purposes. Most of nonlinear dynamic techniques are time-consuming and require a large volume of computations; moreover, performing these analyses and interpreting the obtained results need special skill and expertise. Conversely, although numerous approximations and simplifications in the nonlinear static approaches have extended and promoted their applications, they have reduced the accuracy of the results obtained by these methods. For evaluation of the seismic performance of structures, the precision and speed of the process of different analytical methods are the most important factors. This has led to the development of many novel methods based on the modern nonlinear static and dynamic analyses concepts. In this research, the results of two new different methods (modal incremental dynamic and incremental modified pushover analysis) for two 3-story and 9-story steel moment-resisting frames, as typical low and mid-rise steel lateral load-carrying systems, have been evaluated and compared with the results of the exact nonlinear incremental dynamic analysis. Based on the findings of this research, for the studied frames, the application of both analytical methods for low-rise frames gives appropriate results for all seismic records at different intensity levels; while for the mid-rise frames, the accuracy of the static analysis method has decreased; although a proper safety margin exists for this approach and also the sensitivity of the static method is less than that of the dynamic method

Continuous post-disaster physical rehabilitation: a qualitative study on barriers and opportunities in Iran

Background: Internationally, inclusion of physical rehabilitation services during early disaster response is relatively new. The aim of the study was to gain an understanding of disaster relief physical rehabilitation in Iran. Methods: A qualitative study design was employed and sixteen semi-structured interviews were conducted for data collection. Content analysis was used for data analysis. The participants in this study were purposively selected among people who experienced the Bam (2003) and Varzaghan (2012) earthquakes. Results: Three main themes were explored including: indispensable intervention, barriers to continuous intervention and opportunities for intervention. Almost all participants reiterated the importance of effective physical rehabilitation services during disasters. Some participants mentioned significant barriers for delivering such services in the context of Iran. The lack of an effective responsible body, weak disaster-related competencies and under-prioritization by government were among other barriers. On a more positive note, some interviewees talked about national programs that could facilitate service delivery. Conclusions: Providing disaster relief physical rehabilitation has faced many barriers in Iran. However, there are some facilitators in the country that could help provide these services. Finally, the feasibility of post-disaster physical rehabilitation services delivery completely depends on the current national rehabilitation system

Predictors of Postoperative Atrial Fibrillation after Coronary Artery Bypass Graft Surgery

Objectives The present study was aimed to identify the preoperative, intraoperative, and postoperative predictors of AF in a pure cohort of the patients with coronary artery disease who underwent CABG surgery. Methods Between November 2005 and May 2006, 302 consecutive patients were included in this prospective study. All the relevant clinical, electrocardiographic, echocardiographic, and laboratory data were gathered in the included patients and they were also monitored for development of post-CABG AF.Results Postoperative AF occurred in 46 (15%) of patients. By univariate analysis, older age, P-wave abnormality in ECG, presence of mitral regurgitation, larger left atrium (LA), left main coronary artery involvement, failure to graft right coronary artery (RCA), and adrenergic use in ICU were significantly associated with occurrence of post-CABG AF (all P< 0.05). However, in the logistic regression model, age (OR: 1.067, 95%CI: 1.02-1.116, P=0.005), LA dimension (OR: 1.102, 95%CI: 1.017-1.1936, P=0.017), P-wave morphology (OR: 12.07, 95%CI: 3.35-48.22, P=0.0001), failure to graft RCA (OR: 3.57, 95%CI: 1.20-10.64, P=0.022), and postoperative adrenergic use (OR: 0.35, 95%CI: 0.13-0.93, P=0.036) remained independently predictive of postoperative AF.Conclusion The present study suggested that age, P-wave morphology, LA dimension, failure to graft right coronary artery, and postoperative adrenergic use were independent predictors of post-CABG AF. Therefore, clinical data, ECG and echocardiography may be useful in preoperative risk stratification of the surgical patients for the occurrence of post-CABG A

Results from the translation and adaptation of the Iranian Short-Form McGill Pain Questionnaire (I-SF-MPQ): preliminary evidence of its reliability, construct validity and sensitivity in an Iranian pain population

<p>Abstract</p> <p>Background</p> <p>The Short Form McGill Pain Questionnaire (SF-MPQ) is one of the most widely used instruments to assess pain. The aim of this study was to translate and culturally adapt the questionnaire for Farsi (the official language of Iran) speakers in order to test its reliability and sensitivity.</p> <p>Methods</p> <p>We followed Guillemin's guidelines for cross-cultural adaption of health-related measures, which include forward-backward translations, expert committee meetings, and face validity testing in a pilot group. Subsequently, the questionnaire was administered to a sample of 100 diverse chronic pain patients attending a tertiary pain and rehabilitation clinic. In order to evaluate test-retest reliability, patients completed the questionnaire in the morning and early evening of their first visit. Finally, patients were asked to complete the questionnaire for the third time after completing a standardized treatment protocol three weeks later. Intraclass correlation coefficient (ICC) was used to evaluate reliability. We used principle component analysis to assess construct validity.</p> <p>Results</p> <p>Ninety-two subjects completed the questionnaire both in the morning and in the evening of the first visit (test-retest reliability), and after three weeks (sensitivity to change). Eight patients who did not finish treatment protocol were excluded from the study. Internal consistency was found by Cronbach's alpha to be 0.951, 0.832 and 0.840 for sensory, affective and total scores respectively. ICC resulted in 0.906 for sensory, 0.712 for affective and 0.912 for total pain score. Item to subscale score correlations supported the convergent validity of each item to its hypothesized subscale. Correlations were observed to range from r²= 0.202 to r²= 0.739. Sensitivity or responsiveness was evaluated by pair t-test, which exhibited a significant difference between pre- and post-treatment scores (p < 0.001).</p> <p>Conclusion</p> <p>The results of this study indicate that the Iranian version of the SF-MPQ is a reliable questionnaire and responsive to changes in the subscale and total pain scores in Persian chronic pain patients over time.</p

A Novel Damage Detection Method of Reinforced Concrete Frames Using Signal Processing and Extracted Near-Fault Fling-Step Pulses

A new model-free output-only signal processing-based damage detection procedure was carried out in this paper. First of all, a finite element model as the representative of reinforced concrete (RC) frames was constructed and subjected to a specific loading protocol in OpenSees. The protocol consisted of 9 consequent different near-fault fling-step pulse-type earthquake records with low-amplitude white noises among them to simulate the collapse procedure. The analysis process was complemented in three levels: (a) the Fourier transform was utilized to extract the vibration frequency, (b) the time instants of damage occurrence were detected by using the discrete wavelet transform, and (c) accurate damage detection was made by using the extracted pulse components of the records as loading protocol for earthquake simulation and the discrete wavelet transform. The results revealed that the proposed combinatorial method could efficiently diagnose the damage in the RC frames. Also, applying a pulse component instead of an original record increases the accuracy of damage detection by 70%

Association between hepatitis B surface antibody seropositivity and coronary artery disease

Background : Specific infectious agents have been found to be related to the pathogenesis of coronary atherosclerosis. Aims : We assessed the possible association between angiographically proven coronary artery disease (CAD) and hepatitis B surface antibody (HBS Ab) seropositivity in a population with relatively high prevalence of hepatitis B virus (HBV) infection. Setting and Design : This was a cross-sectional study. Materials and Methods : We analyzed data from 830 consecutive subjects undergoing coronary angiography, including angiographic results reported by two cardiologists for inter-observer reliability and assessment of HBS Ab status determined by enzyme-linked immunosorbent assay (ELISA). Statistical Analysis Used : Chi-square test or Fisher′s exact test, independent two-sample t test and the Pearson′s Correlation Coefficient test were used, as required. Statistics were performed using SPSS software version 13 (SPSS, Chicago, IL). Results : Two hundred forty-nine (30%) subjects had normal angiogram or minimal CAD, and 581 (70%) had significant CAD in at least one major coronary artery. In patients with CAD and in patients without angiographic evidence of significant atherosclerosis, 28.7% and 28.9% respectively were positive for HBV (P = 0.954). Mean C-reactive protein levels in subjects with positive and negative HBS Ab were 10.77 ± 8.37 mg/L versus 10.33 ± 7.64 mg/L respectively (P = 0.465). However, C-reactive protein levels in CAD group were significantly higher (P < 0.001). Conclusions : Our results suggested hepatitis B surface antibody seropositivity has no relationship with coronary artery disease. Moreover, no significant linear correlation exists between HBS Ab and C-reactive protein levels. However, as previously shown, C-reactive protein level in patients with coronary artery disease is significantly higher than in patients with normal coronary arteries

The Effect of Repetitive Transcranial Magnetic Stimulation on Postural Stability After Acute Stroke: A Clinical Trial

Introduction: Balance impairment is a common problem and a major cause of motor disability after stroke. Therefore, this study aimed to investigate whether low-frequency repetitive Transcranial Magnetic Stimulation (rTMS) improves the postural balance problems in stroke patients. Methods: This randomized double blind clinical trial with 12 weeks follow-up was conducted on stroke patients. Treatment was carried with 1 Hz rTMS in contralateral brain hemisphere over the primary motor area for 20 minutes (1200 pulses) for 5 consecutive days. Static postural stability, Medical Research Council (MRC), Berg Balance Scale (BBS), and Fugl-Meyer assessments were evaluated immediately, 3 weeks and 12 weeks after intervention. Results: A total of 26 patients were enrolled (age range=53 to 79 years; 61.5% were male) in this study. Administering rTMS produced a significant recovery based on BBS (df=86, 7; F=7.4; P=0.01), Fugl-Meyer Scale (df=86, 7; F=8.7; P<0.001), MRC score (df=87, 7; F=2.9; P=0.01), and static postural stability (df=87, 7; F=9.8; P<0.001) during the 12 weeks follow-up. Conclusion: According to the findings, rTMS as an adjuvant therapy may improve the static postural stability, falling risk, coordination, motor recovery, and muscle strength in patients with stroke

Association between Androgenic Hormone Levels and Left Ventricular Ejection Fraction

Background: Androgens have been shown to have diverse effects on the cardiovascular system. The aim of this study was to compare androgenic hormone levels in patients with different left ventricular ejection fractions (EF).Methods: The study population consisted of 515 consecutive men who were referred for angiographic studies and whose results of echocardiography and coronary angiography were available. The patients were classified into four groups: EF < 35%, EF = 35-45%, EF = 45-54%, and EF ≥ 55% to evaluate the trends of baseline characteristics and serum androgens,including free testosterone (fT), total testosterone (tT), and dehydroepiandrosterone sulfate (DHEAS). To better elucidate thedifference in the patients with severe heart failure, the patients were divided into two groups according to their EF level, andcomparisons were repeated between those with EF < 35% and the ones with EF ≥ 35%.Results: There were statistically significant trends in some characteristics in the patients with different levels of EF. The subjects with higher EF levels were less likely to have diabetes (p value < 0.001), coronary artery lesion (p value < 0.001),or high levels of C-reactive protein (CRP) (p value < 0.001). As regards the patients with severe heart failure, our regressionanalysis revealed that the fT level was significantly lower in those with EF < 35% than in the ones with EF ≥ 35% (5.82 ± 2.73 pg/mL vs. 6.88 ± 3.34 pg/mL, p value < 0.05).Conclusion: A significant association was found between the level of fT and EF < 35%. There is a need for further controlled prospective studies to delineate any possible causal relationship accurately