Showing 8 results for Meshkat
Volume 3, Issue 2 (5-2017)
Abstract
Background: Klebsiella pneumoniae (K. pneumoniae) causes a wide range of nosocomial and community-acquired infections. In recent decades, K. pneumoniae has been known as the agent of community-acquired primary pyogenic liver abscess. In attempts to find the causes of this disease, researchers found a new virulence gene called magA (mucoviscosity-associated gene A). The present study was performed to determine the prevalence rate of magA gene among the extended-spectrum beta lactamase (ESBL)-positive and ESBL-negative K. pneumoniae strains.
Materials and Methods: The current cross-sectional study was conducted on 130 K. pneumoniae isolates collected from patients in Imam Reza hospital and its associated clinics in Mashhad city (Iran) from May 2011 to July 2012. The presence of K. pneumoniae species was confirmed by conventional microbiological methods. Samples were tested for the production of ESBLs by the double disk diffusion (DDS) test. PCR was performed to detect magA gene. The hypermucoviscosity (HV) phenotype of Klebsiella isolates was characterized by the string test.
Results: magA gene was detected in 11(8.5%) out of 130 isolates of K. pneumoniae. Of 11 isolates with positive result for magA gene, three cases were HV+, and 8 cases were HV- phenotype. Of 130 K. pneumoniae isolates, 56 isolates were ESBL-positive, and 74 isolates were ESBL-negative. The magA gene was detected in 4 out of 56 (7.14%) ESBL-positive, and 7 out of 74 (9.46%) ESBL-negative samples.
Conclusion: In the present study, no correlation was observed between the presence of magA gene and the production of ESBL in K. pneumoniae strains isolated from different clinical samples in Mashhad.
Volume 4, Issue 4 (No.4 (Tome 16), (Articles in Persian) 2013)
Abstract
Forensic phonetics is a subfield of forensic linguistics in which acoustic information and phonetic features of phones are investigated for completing the forensic cases where one of the existing evidences is related to the guilty. One of the most important tasks of a forensic phonetician is forensic speaker recognition. For doing this, the phonetician is asked to estimate the degree of similarity between the given records of the guilty’s and the suspect’s speech, and determine whether these two sound evidences match to each other or not. The objective of this study, which was conducted on the sound data from 10 Persian native speakers of both sexes, was to investigate the possibility of using Logarithmic spectrographs of vowels as a key for forensic speaker recognition tasks. The results showed that using these logarithmic spectrographs may be a useful means with perfect reliability in the tasks related to forensic speaker recognition.
Volume 7, Issue 4 (Fall 2019)
Abstract
Aims: Test anxiety is a significant and scary distressing feeling that appears before, during, or even after the exam.
The current study aimed to predict test anxiety in high school female students based on their spiritual well-being and mindfulness.
Materials & Methods: In this descriptive-analytic and cross-sectional study, the statistical population included all 4
th grade of girl high school students in Tehran (140,000 students). The sample concluded 312 female students of 4
th grade high schools in Tehran selected by multistage cluster sampling. The test anxiety scale developed (2004), Langer's Mindfulness scale (2004), and Well-Being scale (Paloutzian and Ellison; 1982) were completed by participants. Data was analyzed using Pearson correlation test, Enter multiple and stepwise regression.
Findings: Pearson correlation showed a significant and negative relationship between test anxiety and spiritual well-being variables (r=-0.28
; p=0.05) and also the negative relationship with mindfulness (r=-0.44; p=0.05). Regarding the results, students' test anxiety was predictable based on their spiritual well-being and mindfulness and both variables can predict 9% of the variances of changes in the test anxiety (R
2=0.09).
Conclusion: According to the results, the higher level of spiritual well-being and mindfulness, the lower level of test anxiety will be observed in students. So, it is expected that by focusing on specific techniques of mindfulness and performing activities that have a positive impact on students' spiritual well-being can reduce the level of student anxiety and, consequently, improve their academic performance.
Volume 9, Issue 2 (Spring 2021)
Abstract
Aims: Balance is one of the key components of most physical activities. To control balance and choose a balanced strategy, vision plays a crucial role in processing visual inputs. The present study aimed to design and implement a game-like exercise protocol and determine its effectiveness on the static and dynamic balance of children with visual impairment.
Materials & Methods: This quasi-experimental study consisted of all 6-11-year-old children with visual impairment referring to the counseling centers Yazd province and done in the summer 2020. A total of 35 visually impaired children were selected using the purposeful convenience sampling method. After matching, the samples were assigned into an experimental group (n=18) and a control group (n=17). The experimental group received 24 sessions in 60min training. The required data was gathered using the Stork Balance Stand and Timed Up and Go tests for visually impaired children. The collected data were analyzed using ANCOVA by SPSS 20.
Findings: The obtained results showed a significant difference in the means of the static balance test (p<0.01) and the dynamic balance test (p<0.01) between subjects of the experimental and control groups.
Conclusion: Considering the effectiveness of the game-like exercises on improving children's balance with visual impairment, these games are suggested to be implemented daily at home.
Volume 10, Issue 3 (Summer 2024)
Abstract
Background: Multiple sclerosis (MS) is an autoimmune inflammatory disease of the central nervous system. Toxoplasma gondii infection is one of the risk factors of MS. Knowing the correlation between T. gondii infection and MS could lead to a better understanding of the disease incidence. This study aimed to assess the correlation between T. gondii infection and the disease incidence in infected individuals.
Materials & Methods: Serum samples of 38 MS patients referring to the neurology clinic of Ghaem hospital in Mashhad in 2019 were analyzed by Pishtazteb commercial kit for anti-T. gondii IgG and IgM antibodies using enzyme-linked immunosorbent assay (ELISA). The obtained data were analyzed with SPSS software Version 20.
Findings: Among the 79 tested individuals, 22 were positive, and 57 were negative for anti-T. gondii IgG antibodies. Among the negative cases, 29 (50.9%) had MS, and 28 (49.1%) were controls. Among the positive cases, nine (40.9%) patients had MS, and the remaining 13 (59.1%) were controls. The frequency of IgG antibody in the case and control groups was not significantly different (p= .427). Anti-T. gondii IgM antibody was negative in all samples. There was no significant difference between the types of MS regarding the frequency of anti-T. gondii antibodies (p= .402).
Conclusion: No significant difference was found in the frequency of anti-T. gondii IgG antibodies between the two groups. However, further studies with larger sample sizes are recommended to gain a better understanding of the relationship between anti-T. gondii IgG antibody positivity and MS incidence
Volume 10, Issue 4 (Fall 2024)
Abstract
Background: Viral infections may play a significant role in the development of heart failure, especially in people with related cardiac conditions such as myocarditis. Hepatitis B and D viruses (HBV-HDV) are potentially fatal liver infections. This study examined the influence of metabolic syndrome and its associated disorders.
Materials & Methods: This cross-sectional study investigated hepatitis D antibody and hepatitis B surface antigen (HBsAg) in 239 people aged 35 to 65 years in Mashhad, Khorasan Razavi Province, Iran in 2018-2019. There were two study groups: those with cardiovascular diseases (CVD) and healthy individuals. Serum samples of all subjects in both groups were examined using enzyme-linked immunosorbent assay (ELISA).
Findings: HDV infection was detected in none of the study groups. Only one patient (0.8%) in the case group tested positive for HBsAg. The average LDL (low-density lipoprotein) (p= .8) and cholesterol (p= .3) levels in terms of lipid profiles were similar in both groups. Although the mean high-density lipoprotein (HDL) level in the patient group was lower, the mean triglyceride level in this group was higher than in the control group. Fasting blood sugar (FBS) (p= .009) and aspartate aminotransferase (AST) levels were significantly higher in CVD patients, while 59.3% of them exhibited metabolic syndrome.
Conclusion: This study results demonstrate no connection between HBV/HDV infection and cardiovascular diseases. The findings confirm that metabolic syndrome and hyperglycemia are underlying factors in cardiovascular diseases. Changes in HDL and triglyceride levels could impact cardiovascular diseases more than other lipids.
Volume 16, Issue 5 (7-2016)
Abstract
In this paper the flutter phenomenon in turbomachinary is introduced. The importance and characteristics of the flutter as a dynamic aeroelastic instability is presented. Conventional methods for the blade flutter test and different approaches in flutter analysis of blade are described. Among the existing analysis methods, one approach which only examines the stabilizing effect of fluid is used in order to analyze the flutter in this paper. Firstly, its equations are described and a criterion for the determination of the stability based on the analysis results is presented. According to the criterion the local and global stability can be concluded. Numerical analysis has been performed by ANSYS CFX. Mesh independence and two different turbulence models have been examined and results have been validated by test results. Numerical analysis has been carried out for two steady and unsteady states. In unsteady state the response of fluid to blade vibration in three modes has been calculated. In order to assess the total response two methods have been used and the results have been compared. Eventually local instability has been calculated and the results presented in figures which illustrate the contribution of adjacent blades in instability of specific blade. The evaluation of global instability for three modes has been presented and the obtained results are in excellent agreement with experiment.
Volume 23, Issue 3 (8-2023)
Abstract
The evaluation of the fragility functions is an analytical approach that allows different ground motions to be used at varying intensity levels and represent various characteristics of low-intensity and high-intensity shakings. The fragility curves demonstrate the structure’s probability of collapse, or other limit states, as a function of some ground motion intensity measures (IM). The intensity measure is often quantified by spectral acceleration (Sa) or peak ground acceleration (PGA). Based on the statistical procedures, the parameters of the fragility functions are computed by assessing the results of nonlinear dynamic time history analyses. Therefore, the probability of failure associated with a prescribed criterion (e.g. the maximum inter-story drift) is estimated based on the probabilistic distribution relations.
This paper evaluates the effects of internal flexural frames on the seismic performance of diagrid structures based on fragility curves. This evaluation is achieved by designing a group of 24-story studied diagrid models with various diagonal angles of 49, 67, and 74 according to the Iranian Standard No. 2800 (4th edition) and the Iranian National Building Code (Steel Structures-Issue 10). Then, some specific interior gravity frames of the studied diagrid models are replaced with bending frames. The seismic vulnerability of the studied diagrid structures with and without internal bending frames is assessed using nonlinear time history and incremental dynamic analyses (IDA) under near-field earthquake records containing different directivity effects. Finally, the fragility curves for the studied structures were obtained based on the lognormal probabilistic distribution function for the seismic performance limit states including IO, LS, CP, and global instability (GI). Moreover, the seismic performance levels of the studied structures were determined based on the FEMA 356.
The results of performed nonlinear time history analyses indicate that the application of internal bending frames in diagrid structures would reduce the value of inter-story drift in upper floor levels, especially when the angles of exterior diagonal members are large. The results also show that the global instability of diagrid structures without internal bending frames can occur at a faster rate than the skeletal models with internal bents. Also, the contribution of the internal bending frames in improving the nonlinear behavior of diagrid structures depends on the perimeter triangular patterns. Due to this dependency, the increase in the angle of the inclined members in skeletal geometric configuration can increase the effectiveness of the internal bending frames in preventing the occurrence of global dynamic instability. The fragility curves of the studied diagrid structures illustrate that the internal bending frames reduce potentially excessive seismic performance levels. Furthermore, the internal bending frames amplify the seismic energy dissipation capability of the diagrid structures.
