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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: reinforced concrete,penetration,Steel Fiber,Impact Resistance,Erosive Projectiles
- چکیده:
- چکیده انگلیسی: In this paper, modeling of high speed projectiles with different nose shapes, penetrating into steel fiber reinforced concrete is investigated. This is a novel study because it considers the length to diameter ratio of steel fiber as well as projectile length to diameter ratio and volume fraction of fiber used in concrete matrix on the impact resistance of steel fiber reinforced concrete fibers at high speeds. Numerical simulation is used using LS-DYNA explicit code. The projectiles have an approximate mass of 45 (gr) and their velocities are about 2500 (m/s) penetrating into steel fiber reinforced concrete panel with volume fraction of 1.0%, 1.5% and 2.0%. In this article the exact behavior of steel fiber reinforced concrete confronting metallic projectiles at high speed is predicted. The results of the simulations are compared with experimental work of other investigators and, the results show that ogive nose projectiles are more efficient than other projectiles. In other words, by increasing the projectile length to diameter ratio from 0.5 to 0.9, for flat, hemispherical and ogive projectiles their residual velocities are increased. Also, it is shown that by increasing the volume fraction of steel fibers in concrete matrix, damage of top surface damage is reduced dramatically. The analytical model presented in this paper considers the speed variations of the projectile during the penetration process into steel fiber reinforced concrete is an important achievements this respect.
- انتشار مقاله: 18-07-1394
- نویسندگان: Mehdi Hedayatian,Khodadade Vahedi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Kerman University of Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Iranian population,RET proto-oncogene,medullary thyroid cancer,Exon 10,Germline mutation
- چکیده:
- چکیده انگلیسی: Background & Aims: Thyroid cancer is the most common endocrine malignancy. Medullary thyroid carcinoma (MTC) is an aggressive malignant tumor arising from parafollicular cells of the thyroid. MTC occurs in hereditary (25%, hMTC) or sporadic (75%, sMTC) forms. The hMTC form has an autosomal dominant inheritance. RET proto-oncogene mutations, especially the 10, 11, and 16 exones, are associated with MTC. The aim of this study was to determine the type and frequency of RET proto-oncogene exon 10 in patients with MTC. Methods: The study participants included 347 individuals, including 207 patients and 140 of their first degree relatives. Genomic DNA was extracted from peripheral leukocytes using salting out/Proteinase K method. All individuals were tested for RET mutations in exon 10 using polymerase chain reaction (PCR)- DNA sequencing method. Results: A total of 14 germline missense RET mutations were identified in cysteine codons 611, 618, and 620 in 11 patients(10 mutation in males, 4 in females), and 3 of their first-degree relatives (frequency: 3.6%) which were as follows: four C611Y (three FMTC, one relative), one C618R (FMTC), one C618S (sMTC), one C620G (sMTC), four C620R (one FMTC, three sMTC), and three C620F (one FMTC, two relatives). The most predominant mutations in exon 10 in our FMTC and sMTC patients were C611Y and C620R, respectively. We did not find any mutations in cysteine codon 609. Conclusion: In the present study, 6 different types of missense mutations were identified in exon 10 of RET in the nonsyndromic form of MTC. Based on the results of this study, mutation detection using DNA sequencing in exons 10, 11, and 16 of RET in patients with MTC and their relatives is recommended.
- انتشار مقاله: 24-04-1395
- نویسندگان: Marjan Zarif-Yeganeh,Sara Sheikholeslami,Golnoush Dehbashi-Behbahani,Samaneh Farashi,Laleh Hoghooghi-Rad,Fereidoun Azizi,Mehdi Hedayati
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Health Sciences and Surveillance System
- نوع مقاله: Journal Article
- کلمات کلیدی: Overweight,Milk,Iron,Calcium,Premenopausal
- چکیده:
- چکیده انگلیسی: Background: Although it is assumed that calcium has beneficial effects on weight loss, the interaction of calcium and iron would be a major concern. We did this study to investigate the effects of calcium and low-fat milk on serum ferritin in overweight or obese premenopausal women. Methods: Sixty-four healthy overweight or obese premenopausal women recruited in Shahid Beheshti University of Medical Sciences clinics participated in this clinical trial. Participants were randomly allocated to one of the following dietary regimens for 8 weeks: 1) a control diet providing a 500 kcal/day deficit, with 500-600mg/day dietary calcium; 2) a calcium- supplemented diet identical to the control diet with 800mg/day calcium carbonate 3) a milk diet providing a 500kcal/day deficit and containing three servings of low fat milk. Serum ferritin and anthropometric indices were measured at baseline and after 8 weeks. Primary outcome measure was serum ferritin level. Results: Mean±SD of baseline values for age, body mass index (BMI), waist circumference (WC), and serum ferritin were 37.44±9.46 (year), 30.79±3.63 (kg/m2), 88.04±8.90 (cm), and 59.20±47.8 (μg/l), respectively. There were no significant differences in baseline age, BMI, WC, and serum ferritin among 3 groups. Mean values of serum ferritin reductions were 0.26±20.36, 14.59±17.07 and6.57±25.93 (μg/l) in control, calcium, and milk groups, respectively. Reduction in serum ferritin was only significant in the calcium group (P=0.003). Serum ferritin reductions were not significantly different among the 3 groups (P=0.260). Conclusion: An energy-restricted diet in combination with calcium supplement or low-fat milk does not induce any additional adverse effect on iron status, compared to an energyrestricted diet alone.
- انتشار مقاله: 12-05-1393
- نویسندگان: Shiva Faghih,Mehdi Hedayati
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Health Sciences and Surveillance System
- نوع مقاله: Journal Article
- کلمات کلیدی: Overweight,Milk,Calcium,lipid profile,Metabolic Syndrome
- چکیده:
- چکیده انگلیسی: Background: Obesity and metabolic syndrome are serious public health problems. It is suggested that high calcium diet can improve lipid profile, blood pressure and insulin resistance.Methods: In this clinical trial, 75 healthy overweight or obese premenopausal women were randomly allocated to one of the following dietary regimens for 8 weeks: 1) a control diet 2) a calcium-supplemented diet containing 800mg/d calcium carbonate 3) a high milk diet containing three servings of low fat milk (all of them providing a 500kcal/day deficit). At baseline and after 8 weeks, waist circumference (WC), blood pressure, serum triglyceride (TG), fasting blood sugar (FBS), and high density lipoprotein cholesterol (HDL-C) were measured.Results: After 8 weeks, WC, FBS and HDL-C decreased in all groups (P<0.001), but there were no significant reduction in TG and blood pressure. Reduction of WC in the milk group was significantly higher than the controls (P=0.028). Also, reduction of HDL-C in the calcium and milk groups was less than the controls (P=0.023 and P=0.019, respectively). Changes in FBS, TG and blood pressure were not significantly different among the 3 groups.Conclusion: We found that increasing milk consumption led to more WC reduction. Milk or calcium intake caused less adverse effect on HDL-C, but has no effect on the blood pressure, FBS and TG. So increase in milk or calcium intake can reduce WC among the metabolic syndrome complications.
- انتشار مقاله: 20-05-1392
- نویسندگان: Shiva Faghih,Alireza Abadi,Mehdi Hedayati,Seyed Masoud Kimiagar
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dentistry, Shiraz University of Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: Statement of the Problem: Root resorption (RR) after orthodontic tooth movement (OTM) is known as a multifactorial complication of orthodontic treatments. Hormonal deficiencies and their effect on bone turnover are reported to have influences on the rate of tooth movement and root resorption.Purpose: This study was designed to evaluate the effect of female and male steroid sex hormones on tooth movement and root resorption.Materials and Method: Orthodontic appliances were placed on the right maxillary first molars of 10 ovariectomized female and 10 orchiectomized male Wistar rats as experimental groups and 10 female and 10 male healthy Wistar rats as control groups. NiTi closed-coil springs (9mm, Medium, 011"×.030", Ortho Technology®; Tampa, Florida) were placed between the right incisors and the first right maxillary molars to induce tipping movement in the first molars with the application of a 60g force. After 21 days, the rats were sacrificed and tooth movement was measured by using a digital caliper (Guanglu, China). Orthodontic induced root resorption (OIRR) was assessed by histomorphometric analysis after hematoxylin and eosin staining of sections of the mesial root.Results: The rate of tooth movement was significantly higher in all female rats, with the root resorption being lower in the experimental group. The rate of tooth movement in experimental male rats was significantly higher than the control group (p= 0.001) and the rate of root resorption was significantly lower in the experimental group (p= 0.001).Conclusion: It seems that alterations in plasma levels of estrogen, progesterone, and testosterone hormones can influence the rate of OTM and RR. The acceleration in tooth movement increased OTM and decreased RR.
- انتشار مقاله: 19-04-1393
- نویسندگان: Massoud Seifi,Baharak Ezzati,Sara Saedi,Mehdi Hedayati
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Basic and Clinical Pathophysiology
- نوع مقاله: Journal Article
- کلمات کلیدی: Diabetes Mellitus,Streptozotocin,Key words: Oxidative Stress,Resistance exercise
- چکیده:
- چکیده انگلیسی: Abstract
Background and Objective: It has been shown that oxidative stress increases in diabetes and it has an important role in its development and subsequent complications. Thus, the aim of this study was to investigate the effect of acute resistance exercise on oxidative stress in skeletal muscle and cardiac tissues of streptozotocin-induced diabetic rats.
Materials and Methods: Twenty male wistar rats were rendered diabetic by a single dose of streptozotocin (STZ; 50 mg/kg, IP) and were randomly divided into two groups: (1) acute resistance exercise and (2) sedentary control. Acute resistance exercise consisted of 4 separate sessions of exercise that happened in non-consecutive days. After the last session, the animals were anesthetized by xylazine (10 mg/kg) and ketamine (75 mg/kg) and flexor hallucis longus (FHL) muscle and heart were surgically removed and stored at -80 °C until biochemical analysis of malondialdehyde (MDA), protein carbonyl (PC), and glutathione (GSH) was done.
Results: Our findings showed a significant decrease of MDA (p=0.007), but not PC level (p=0.678) of cardiac tissue of resistance exercise group. However, in FHL muscle, resistance exercise caused a significant increase in MDA (p=0.01), but there was no significant changes in PC level (p=0.399). Resistance exercise also caused a small but insignificant increase in GSH content of both skeletal and cardiac muscle tissues (p=0.11 and p=0.19, respectively).
Conclusion: We observed that in diabetic rats, acute resistance exercise decreases cardiac tissue MDA, increases skeletal muscle MDA level, and had no significant effect on PC and GSH level. Further research is needed to specify the mechanisms of these differences in various tissues following resistance exercise.- انتشار مقاله: 12-09-1392
- نویسندگان: Ali . Samadi,Abbasali Gaeini,Aliasghar Ravasi,Mehdi Hedayati,Mostafa Rahimi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Veterinary Medicine
- نوع مقاله: Journal Article
- کلمات کلیدی: Milk,Processing,iodine,: Dairy cow,Human need
- چکیده: زمینهمطالعه: امروزه شیر بهعنوان منبع مهمی برای تأمین نیاز ید روزانه گروههای مختلف سنی در برخی کشورها مطرح است اما در ایران اطلاعات زیادی در مورد غلظت ید شیر مصرفی موجود در بازار وجود ندارد.
هدف: هدف از این مطالعه تعیین غلظت ید شیر مصرفی موجود در بازار و بررسی میزان سهم آن در تامین نیاز گروه های مختلف سنی افراد جامعه است.
روشکار: در مرحله اول این مطالعه، از تانک حجمی شیر 10 گاوداری صنعتی (در دو منطقه گرمسیر و سردسیر استان تهران) نمونه برداری شد. در مرحله دوم نیز شش برند شیر پرمصرف بازار انتخاب و غلظت ید نمونههای بدست آمده به روش سندل کالتوف اندازهگیری شد.
نتایج: شیر خام گاوداریهای مناطق سردسیر 3/24 ± 7/50 درصد ید کمتری نسبت به نمونههای شیر خام گاوداریهای مناطق گرمسیر داشتند (05/0>P). شیر استریلیزه (0/111 ± 0/282 میکروگرم در هر لیتر) ید بیشتری نسبت به شیر خام (9/116 ± 3/224 میکروگرم در هر لیتر) داشت (05/0> P). محتوای چربی نمونههای آزمایشی (شیرپرچرب یا کم چرب) اثری بر غلظت ید نداشت (05/0<P).
نتیجهگیرینهایی: نتیجه گیری نهایی: بر اساس میانگین مصرف شیر جامعه ایرانی، شیرهای خام، پاستوریزه و استریلیزه بطور میانگین به ترتیب 6/74، 6/84 و0/96 میکروگرم و یا به ترتیب 8/29، 8/33 و 6/37 درصد نیاز ید روزانه افراد بزرگسال را تأمین می کنند.- چکیده انگلیسی: BACKGROUND:Due to the large proportion of iodine present in milk and dairy products, they have been one of the important sources of nutritional iodine in several countries. Information about variation in milk iodine concentration in Iran is limited.
OBJECTIVES:The present study was conducted to determine the iodine concentration in Iranian milk and dairy milk products.
METHODS: In the first step, 10 commercial dairy farms (five located in tropical and other located in cold region) were included in the study. In the second step, the iodine concentration of six samples of different milk products from the retail market was determined by Sandell-Kolthoff (acid-digestion) reaction.
RESULTS: The average iodine concentration of milk samples from cold region was significantly lower (50.7 ± 24.3 %) than the iodine concentration of milk samples from the tropical region (P<0.05). Sterilized milk (282.0 ± 111.0 µg/l) had higher and raw milk (224.3 ± 116.9 µg/l) had lower iodine concentration (P<0.05). There was no effect of milk fat class (whole and semi-skimmed) on milk iodine concentration (P>0.05).
CONCLUSIONS: Based on Iranian dairy product intake, raw, pasteurized and sterilized milk provides on average, 74.6, 84.6, 96.0 µg of iodine, approximately 29.8, 33.8, 37.6 % of the adult recommended dietary allowance for this nutrient, respectively.- انتشار مقاله: 07-08-1398
- نویسندگان: Mohammad Reza Rezaei Ahvanooei,Mohammad Ali Norouzian,Mehdi Hedayati
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Dermatology
- نوع مقاله: Journal Article
- کلمات کلیدی: Antioxidants,Psoriasis,Oxidants
- چکیده:
- چکیده انگلیسی: Background: The etiology of psoriasis, a chronic inflammatory skin disease, has not been elucidated. However, Oxidant / antioxidant imbalance is suspected.The aim of this study was to evaluate oxidant / antioxidant status in psoriatic patients.
Method: forty two psoriatic patients and 42 age and sex matched controls were recruited for this study. Serum total antioxidant capacity (TAC), oxidized light density lipoprotein (Ox-LDL) and malondialdehyde (MDA) levels were determined.
Results: A statistically significant increase in the serum level of MDA was found between patients and controls. No significant difference was found in the serum levels of other parameters in the two groups.
Conclusion: Our results supported the hypothesis of an imbalance between oxidants and antioxidants in psoriasis and pointed to the probability of an increased risk of cardiovascular diseases in psoriatic patients.- انتشار مقاله: 11-10-1348
- نویسندگان: Soheila Nassiri,Farhad Malekzad,Mojdeh Sarlak,Marjan Saeedi,Mehdi Hedayati,Mehdi Qaisari
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Obesity,IL-6,Inflammatory Markers,Hcy,Hs-CRP,TLGS
- چکیده:
- چکیده انگلیسی: Objective(s):Obesity considered being a low-grade inflammatory disease. The objective of this study was to examine the association between inflammatory markers (IM) including C-reactive protein (hs-CRP), Interleukin-6 (IL-6), and homocystein (Hcy) and obesity[F1] -related factors (e.g. BMI, waist, hip) in adult participants of Tehran lipid and glucose study (TLGS).
Materials and Methods: In this cross-sectional study, 352 individuals (132 men and 220 women), age ≥19 years, were randomly recruited from participants of TLGS population[F2] . The serum levels of hs-CRP, IL-6, Hcy were determined using the enzyme linked immunosorbent assay (ELISA) method[F3] . Variables were compared by sample t-test. Bivariate linear correlation was estimated using Pearson’s correlation coefficient. Linear regression analysis was applied to investigate the association between IMs and anthropometric and biochemical variables.
Results: The mean age of participants was 46.1±16.1 years. abdominal obesity was present in 199(56.5%) individuals. levels of hs-CRP and IL-6 increased in the abdominally obese group (1507±3.3 vs. 577.8±4.3 ng/ml P<0.001) (3.6±3.3 vs. 1.9±3.8 pg/ml P< 0.001), and in the same group, the best predictors for hs-CRP, IL-6 and Hcy were waist (WC), waist to height ratio (WHtR) and wrist respectively; hip and WHtR were the best predictors for Hcy and hs-CRP in the normal group. A linear augmentation in hs-CRP and IL-6 levels was observed in association with obesity categorizes.
Conclusion: This study provides evidence that abdominally obese individuals had higher levels of IMs. Wrist, waist and WHtR were the best predictors for Hcy, hs-CRP and IL-6 respectively in this group.
- انتشار مقاله: 05-06-1393
- نویسندگان: Bita Faam,Maryam Zarkesh,Maryam Sadat Daneshpour,Fereidoun Azizi,Mehdi Hedayati
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Basic Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی: Food intake,High fat diet,Endurance Training,Peptide hormones
- چکیده:
- چکیده انگلیسی: Objective(s):Consumption of high-fat foods is one of the major causes of obesity. Physical exercise is a strategy used to counteract obesity. The aim of this study was to investigate the effect of eight weeks endurance training and high-fat diet (HFD) on appetite-regulating hormones in rat plasma.
Materials and Methods:Twenty eight male Wistar rats were randomly divided into four groups: Control group with standard diet (CSD), endurance training with a standard diet (ESD), control group with high-fat diet (CHFD) and endurance training with high-fat diet (EHFD). Twenty-four hr after the last training session, the blood samples were obtained and analyzed for hormones levels.
Results: The significant increased weight gain and food intake and decreased plasma nesfatin-1 and PYY3-36 levels were observed in CHFD group, while exercise under the HFD antagonized these effects. There were no significant changes in ghrelin, insulin and leptin levels in different groups.
Conclusion: These results suggest that exercise can prevent fattening effect of HFD. Probably, performing exercise makes a reduction of food intake and weight gain in rat via the increase in nesfatin-1 and PYY levels. However, further studies are necessary to understand the exact mechanisms involved in this field.- انتشار مقاله: 30-01-1393
- نویسندگان: Rouhollah Haghshenas,Mahvash Jafari,Aliasghar Ravasi,Mohammadreza Kordi,Neda Gilani,Mohammad Shariatzadeh,Mehdi Hedayati,Mostafa Rahimi
- مشاهده