64 research outputs found
Stress Intensity Factors for Circumferential Semi-Elliptical Cracks in Cylinders Subjected to Forced Convection Heat Transfer
This paper analyzes the circumferential semi-elliptical crack on the inner surface of a thick-walled cylinder while keeping the thermal loading in steady state. Forced convection heat transfer in the inner surface and free convection in the outer surface are applied to the cylinder, which was constructed from isotropic and homogeneous materials. To this end, the thermal stress intensity factors are determined using the weight function method. To validate the results, 3-D finite element method is applied as well as API standard code. Due to the existence of two planes of symmetry, only a quarter model of the cylinder was used and along the crack front, the modelling is carried out over singular isoparametric elements. The results for stress intensity factor are obtained at different aspect ratios and relative depths of the crack. The stress intensity factors calculated via built-in J-integral solver based on the domain integral technique in the ABAQUS software. The results obtained via this method were in good agreement with the proposed weight function, demonstrating the latter’s high adequacy and efficiency
Psychometric properties of the Persian version of the Fatigue Impact Scale (FIS-P) in patients with Multiple Sclerosis
Objectives: This study was designed to evaluate the psychometric features of the Persian version of the Fatigue Impact Scale (FIS-P) tool when used in Iranian MS patients. Methods: 140 MS patients and the equivalent number of healthy controls completed the following assessments: FIS-P, Fatigue Severity Scale (FSS), SF-36 questionnaire and the Mini-Mental State Examination (MMSE). Results: A significant inverse correlation between FIS and the quality of life (SF-36 assessment tool), as well as a positive and significant correlation with the FSS were noted. The Intraclass Correlation Coefficient (ICC) values for the inter-rater reliability for the physical, cognitive, and social sections and the whole questionnaire were 0.89, 0.86, 0.95 and 0.98, respectively. The FIS Persian version was shown to possess a high reliability (with a Cronbach's alpha of 0.953). Likewise, the ICC values for the testretest reliability were 0.86, 0.87, 0.92 and 0.93 for the physical, cognitive, social subscales and the whole questionnaire, respectively. This suggested a high reliability for the FIS-P. Discussion: With a proper validity and reliability, the Persian-version of FIS retains the capability for being used in the assessment of fatigue and evaluation of the treatment and rehabilitation effects on fatigue-related symptoms among Persian-speaking patients with MS
Identification and abundance estimation of planktonic copepods in Khoor-e-Musa creek
This project was carried out in the Khoor-e-Musa creek near Bandar Imam Khomeini from December 1996 to February 1998, with a view to studying the abundance and dominance of the Copepod community in the area. Monthly sampling was done in four stations from December 1996 to September 1997 and subsequantly samples were collected from al11he stations also in December 1997 and February 1998. Horizontal and vertical samplings (from 20 m depth to the surface layer) was carried out. Totally 16 genera of planktonic copepods were observed, of which, 11 genera belonged to Calanoida, 2 genera to Harpacticoida and Poecilostomatoida, and one genus to Cyclopoida. The most dominant genera was Acartia with relative abundance of 75.9% and the least dominant was Corycaeus with 0.002%. ANOV A did not show any significant difference in abundance among the stations. But among months ANOVA showed significant differance (a=0.05). The peak density was observed in May. The T-test showed significant difference between column and surface densities only in February 1997 (a=0.05). Temperature, pH, DO and salinity in four sampling stations showed no significant differences. But ANOV A showed significant differances for pH and temperature (a=0.05), in different months
Novel weight functions and stress intensity factors for quarter-elliptical cracks in lug attachment
In this paper, a general weight function is developed to calculate the stress intensity factors (SIFs) for quarter-elliptical cracks in a wide range of lug attachment family. For this purpose, a series of finite element analyses are performed. Finally, using this unique extracted weight function, the influence of the pin loading model and crack parameters (aspect ratio and relative depth of the quarter-elliptical crack) on the SIFs is evaluated in the cracked lug attachments. The results of the present work are compared with some data available in the literature, and the agreement is satisfactor
Can hand dexterity predict the disability status of patients with multiple sclerosis?
Background: Multiple Sclerosis (MS) is the most common disabling neurological disease. Hand dysfunction is one of the main complaints of patients with MS. The present study aimed to compare hand dexterity of MS patients with low Expanded Disability Status Scale (EDSS) scores and healthy adults. It also sought to identify the predictors of disability status of patients with MS based on their manual dexterity and demographic characteristics. Methods: In this cross-sectional study, 60 (16 male/44 female) patients with MS and 60 (19 male/41 female) healthy people, who matched in terms of age and sex, were recruited. Their hand dexterity was evaluated by the Purdue Pegboard Test. The disability status of the MS group was determined by the Expanded Disability Status Scale. The data were analyzed using SPSS15. Results: The hand dexterity in MS group even with low EDSS score (1.5 ± 1.07) was weaker than control group. Moreover, the dexterity of dominant hand and alternating two hands coordination subtests of the PPT was a good discriminator between two groups (p<0.001). The results of linear regression analysis suggested dominant hand dexterity and disease duration as predictors of disability status that predict 60.5 per cent of the variation in EDSS scores in patients with MS (p<0.001). Conclusion: Reduced dominant hand dexterity in patients with MS is a disabling factor. Further research is recommended to determine if early hand rehabilitation can reduce the severity of disability in Patients with MS
Heavy metals (Hg,Cd,Pb,Ni,Cu) concentrations in Euryglossa orientalis and sediments from Khur-e-Musa Creek in Khuzestan Province
Heavy metals contamination (Hg,Cd,Pb,Ni,Cu) in muscle of the fish Euryglossa orientalis and in sediments was assessed in 2007 in Khur-e-Musa Creek (Ahmadi and Ghanam). In total, 30 fish specimens and 18 sediment samples were collected and analyzed. Flame Atomic Absorption Spectrophotometer was used to determine contamination of the specimens with Cd, Pb, Ni, Cu, and cold vapor method was applied for Hg. Results showed 2.35, 0.99, 1.32, 14.48 and 5.71µg/g dry weight of the fish for Hg, Cd, Pb, Ni and Cu in muscle tissue, respectively. Metal levels in the muscle tissue were compared with standard values such as those of the World Health Organization (WHO), British Ministry of Agriculture, Fisheries and Food (MAFF), Australia National Health and Medical Research Council (NHMRC) and American Food and Drug Administration (FDA), based on which only Hg, Cd, and Ni showed higher than standard levels in Khur-e-Musa Creek (Ahmadi and Ghanam). Results showed 4.76, 2.52, 18.64, 119.91, 31.23µg/g dry weight for Hg, Cd, Pb, Ni and Cu in sediments, respectively
Menstrual disorders and related factors in women with multiple sclerosis
Introduction: Multiple sclerosis (MS) is the most common autoimmune disease that often affects women within the reproductive age. Among the common clinical complaints in these women is variety of menstrual disorders. Thus, we aimed to examine menstrual disordersand related factors in women with MS.Methods: A descriptive cross-sectional study was performed among 172 women with MS who visited the Neurology Specialized Clinic in Tehran, Iran, during 2016-2017. The participants filled out a questionnaire consisting of demographic (e.g., age, educational level, economic status, disease duration, vitamin D consumption duration, and Expanded Disability Status Scale EDSS) and disease characteristics (age at menstruation, duration of each period, interval between two periods, the amount of bleeding, presence or lack of presence of pain, and menstruation pain score). Data were analyzed by using SPSS version 22 and multiple logistic regression model, Chi-square test, and Spearman correlation coefficient. P-value less than 0.05 was considered significant.Results: Overall, 88 patients (51.2%) experienced irregular menstruation patterns, and 116 patients (67.5%) had some forms of menstruation disorders. Multiple logistic regression reflected statistically significant correlations between disability score (β=0.702, P=0.001), moderate (β=2.561, P<0.001) and high (β=2.730, P<0.001) menstrual bleeding, duration of vitamin D intake (β= -0.187, P=0.048), dysmenorrhea (β=1.246, P=0.006), age of the menarche (β= -0.298, P=0.05) and menstrual pattern (β=1.912, P<0.001) with menstrual disorders. Spearman correlation and Chi-square revealed the significant relationship of menstruation pattern, dysmenorrhea, and amount of bleeding with menstrual disorders, which corroborated the results of regression. Conclusion: The results of the present study showed that menstrual disorders have high prevalence in women with MS. Our results also indicated that factors such as duration of vitamin D intake, menstrual bleeding, menarche, menstrual pattern, dysmenorrhea, and EDSS affect menstrual disorders. © 2018, Mashhad University of Medical Sciences. All rights reserved
Molecular targets of curcumin for cancer therapy: An updated review
In recent years, natural edible products have been found to be important therapeutic agents for the treatment of chronic human diseases including cancer, cardiovascular disease, and neurodegeneration. Curcumin is a well-known diarylheptanoid constituent of turmeric which possesses anticancer effects under both pre-clinical and clinical conditions. Moreover, it is well known that the anticancer effects of curcumin are primarily due to the activation of apoptotic pathways in the cancer cells as well as inhibition of tumor microenvironments like inflammation, angiogenesis, and tumor metastasis. In particular, extensive studies have demonstrated that curcumin targets numerous therapeutically important cancer signaling pathways such as p53, Ras, PI3K, AKT, Wnt-β catenin, mTOR and so on. Clinical studies also suggested that either curcumin alone or as combination with other drugs possess promising anticancer effect in cancer patients without causing any adverse effects. In this article, we critically review the available scientific evidence on the molecular targets of curcumin for the treatment of different types of cancer. In addition, we also discuss its chemistry, sources, bioavailability, and future research directions. © International Society of Oncology and BioMarkers (ISOBM) 2016
Effect of expressive writing on promotion of body image in women with multiple sclerosis: A randomized controlled trial
Background and purpose: Multiple sclerosis (MS) affects own physical function and body image. The aim of this study was to determine the effect of expressive writing on body image in women with MS. Materials and methods: In this randomized trial, the Solomon four-group design was employed. The study was carried out in 116 women attending an MS clinic in Tehran, Iran 2019. The participants were randomly assigned to two subgroups of control (A1 and A2) and two subgroups of intervention (B2 and B1). Pretest and posttest were done in A2 and B2 while for A1 and B1only posttest was performed. Expressive writing including morning pages, meeting the inner child, and creative assignments were carried out for six weeks. The control group received routine care. Fisher Body Focus Questionnaire was completed at pretest in A2 and B2 and at posttest in all groups (immediately after the intervention, and at weeks four and eight). Data analysis was done in SPSS V26. Results: The mean scores for body image in B2 were 145.65±19.89 at pretest, 156.89±9.54 immediately after the intervention, 158.16±8.92 at week four, and 153.96±8.27 at week eight. In A2, the mean score at these times were 144.96±7.17, 145.55±5.10, 145.28±7.84, 145.00±9.15, respectively. Expressive writing significantly improved body image in B2 at immediately and four weeks after the intervention compared to pretest (P<0.001). There were significant differences between the control group and intervention group at immediately after (P=0.002) and four weeks (P=0.03) after the intervention. Conclusion: Expressive writing could be effective in improving body image in women with MS. © 2021, Mazandaran University of Medical Sciences. All rights reserved
Lettuce and marigold intercropping: crops productivity and marigold's flavonoid content
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