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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:
- چکیده:
- چکیده انگلیسی: In this paper, the resonant frequency and sensitivity of an atomic force microscope (AFM) with an assembled cantilever probe (ACP) are analyzed utilizing the modified couple stress theory. The proposed ACP comprises a horizontal microcantilever, an extension and a tip located at the free end of the extension, which make AFM capable of scanning the sample sidewall. First, the governing differential equation and boundary conditions for dynamic analysis are obtained by a combination of the basic equations of the modified couple stress theory and Hamilton principle. Then, a closed form expression for the resonant frequency are derived, and using this expression the sensitivity are also investigated. The results of the proposed model are compared with those of the classic beam theory. The comparison shows that the difference between the results predicted by these two theories becomes significant when the horizontal cantilever thickness comes approximately close to the material length scale parameter, in which for some values of contact stiffness the difference reaches its maximum. It can also be inferred that a decrease in the microcantilever thickness could have a knock on effect on the shifts of first frequency and first sensitivity caused by an increase in the extension length.
- انتشار مقاله: 05-07-1394
- نویسندگان: M. Abbasi,A. Karami Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Sciences, Islamic Republic of Iran
- نوع مقاله: Journal Article
- کلمات کلیدی: Nucleus Accumbens,Schizophrenia,shRNA,DRD2,Prepulse Inhibition
- چکیده:
- چکیده انگلیسی: Prepulse Inhibition (PPI), the objective measure of sensorimotor gating disturbance has being widely used in animal models of schizophrenia. Dopaminergic direct and indirect agonists impair PPI. However, the profile of dopaminergic receptors involved in PPI impairment by dopamine agonists is not clear. By injecting shRNA expressing plasmids against dopamine D2 receptor genes (DRD2) in the nucleus accumbens, here, we studied the effect of apomorphine on PPI in D2 down-regulated rats. Seventy two adult Wistar rats assigned randomly in nine groups, each received coding (250 and 500 ng/µl) or noncoding shRNA expressing plasmids against DRD2 in the nucleus accumbens, with or without apomorphine (0.5 mg/kg, S.C., 72 hours after treatment with plasmids). Auditory startle response and PPI were measured after apomorphine injection. Real time RT-PCR was used to measure DRD2 expression. Results showed that apomorphine significantly decreased PPI in noncoding plasmid treated rats; While, PPI did not impaired in rats pretreated with 250 and 500 ng/µl shRNA expressing plasmids. Accordingly, the expression of DRD2 mRNA in the nucleus accumbens showed 72-78% decrease in expressing plasmid treated rats. Additionally, treatment with expressing plasmids had no effect on basal PPI and/or auditory startle response. Taken together, our results demonstrated that DRD2 silencing in the nucleus accumbens can prevent PPI impairment by apomorphine. These observations suggest application of molecular techniques such as the use of shRNA against DRD2s in studies of schizophrenia pathophysiology and development of new treatments in schizophrenia.
- انتشار مقاله: 16-05-1394
- نویسندگان: M.R. Noori-daloii,A. Shahbazi,S. Alizadeh Zendehrood,A. Shayan Nia,M. Mojarrad,M. Kheirollahi,A. Rashidi-Nezhad,A. Haghparast,F. Zare Mehrjerdi,S. Niknazar,M. Mostowfi,H. Hashemi Sotoobadi,M. Khaksari,A. R. Noori-Daloii,A. Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Nanostructures
- نوع مقاله: Journal Article
- کلمات کلیدی: Nanoparticles,Nanocomposite,Thermal stability,cellulose acetate
- چکیده:
- چکیده انگلیسی: Mg(OH)2 nanoparticles were synthesized by a rapid microwave reaction. The effect of sodium dodecyl sulfonate (SDS as anionic surfactant) and cetyl tri-methyl ammonium bromide (CTAB as cationic surfactant) on the morphology of magnesium hydroxide nanostructures was investigated. Multi wall carbon nano tubes was organo-modified for better dispersion in cellulose acetate matrix. The influence of Mg(OH)2 nanoparticles and modified multi wall carbon nano tubes (MWCNT) on the thermal stability of the cellulose acetate (CA) matrix was studied using thermo-gravimetric analysis (TGA). Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Thermal decomposition of the nanocomposites shift towards higher temperature in the presence of Mg(OH)2 nanostructures. The enhancement of thermal stability of nanocomposites is due to the endothermic decomposition of Mg(OH)2 and release of water which dilutes combustible gases.
- انتشار مقاله: 12-05-1394
- نویسندگان: M. Ghorbanali,A. Mohammadi,R. Jalajerdi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Mining and Environment
- نوع مقاله: Journal Article
- کلمات کلیدی: Resistivity,Geological structures,Ground Penetrating Radar (GPR),C–North deposit,Sangan
- چکیده:
- چکیده انگلیسی: Ground Penetrating Radar (GPR) is an effective and practical geophysical imaging tool, with a wide set of applications in geological mapping of subsurface information. This research study aims at determination of the geophysical parameter differences in the subsurface geological structures and construction of a 3D fracture model. GPR and resistivity methods were applied to detect the unstable tectonic zones in the C-North deposit. Structural geology investigations were, first, surveyed to detect the faults and fractures in the study area. Based on the structural features, the survey was conducted over an area of 1 km2 with a total of 30 profiles and low-resistivity zones in the C-North deposit which is a great help in reducing their impacts in slope stability studies. GPR sections were, then, obtained from low and high frequency antennas (10 and 50 MHz) to detect fractures and water content zones. The obtained data results demonstrated that the major structural trends in the study area were W–E, NE–SW, and NW–SE while fault zones that can create pathways for groundwater inflow into the deposit in the future. Information obtained from geological and GPR studies were also integrated with drill hole data. The geological information from structures are in good agreement with the actual geological situation. Method and results of this study could be useful in solving problems related to subsurface structures in mining engineering.
- انتشار مقاله: 28-05-1397
- نویسندگان: A. Rezaei,H. Hassani,P. Moarefvand,A. Golmohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Electrical and Computer Engineering Innovations (JECEI)
- نوع مقاله: Journal Article
- کلمات کلیدی: FPGA,Convolution,Gabor Filter,Separable Filter,HMAX Model
- چکیده:
- چکیده انگلیسی: Background and Objectives: Programmable logic devices, such as Field Programmable Gate Arrays, are well-suited for implementing biologically-inspired visual processing algorithms and among those algorithms is HMAX model. This model mimics the feedforward path of object recognition in the visual cortex.
Methods: HMAX includes several layers and its most computation intensive stage could be the S1 layer which applies 64 2D Gabor filters with various scales and orientations on the input image. A Gabor filter is the product of a Gaussian window and a sinusoid function. Using the separability property in the Gabor filter in the 0° and 90° directions and assuming the isotropic filter in the 45° and 135° directions, a 2D Gabor filter converts to two more efficient 1D filters.
Results: The current paper presents a novel hardware architecture for the S1 layer of the HMAX model, in which a 1D Gabor filter is utilized twice to create a 2D filter. Using the even or odd symmetry properties in the Gabor filter coefficients reduce the required number of multipliers by about 50%. The normalization value in every input image location is also calculated simultaneously. The implementation of this architecture on the Xilinx Virtex-6 family shows a 2.83ms delay for a 128×128 pixel input image that is a 1.86X-speedup relative to the last best implementation.
Conclusion: In this study, a hardware architecture is proposed to realize the S1 layer of the HMAX model. Using the property of separability and symmetry in filter coefficients saves significant resources, especially in DSP48 blocks.
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======================================================================================================- انتشار مقاله: 04-03-1399
- نویسندگان: A. Mohammadi Anbaran,P. Torkzadeh,R. Ebrahimpour,N. Bagheri
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Industrial and Systems Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: GA algorithm,Taguchi Method,Fixed-charge transportation problem,SA algorithm,SFS algorithm,RDA algorithm
- چکیده:
- چکیده انگلیسی: In most real world application and problems, a homogeneous product is carried from an origin to a destination by using different transportation modes (e.g., road, air, rail and water). This paper investigates a fixed charge transportation problem (FCTP), in which there are different routes with different capacities between suppliers and customers. To solve such a NP-hard problem, four meta-heuristic algorithms include Red Deer Algorithm (RDA), Stochastic Fractal Search(SFS), Genetic Algorithm (GA), and Simulated Annealing (SA) and two new hybrid meta-heuristics include hybrid RDA & GA (HRDGA) algorithm and Hybrid SFS & SA (HSFSA) algorithm are utilized. Regarding the literature, this is the first attempt to employ such optimizers to solve a FCTP. To tune up their parameters of algorithms, various problem sizes are generated at random and then a robust calibration is applied by using the Taguchi method. The final output shows that Simulated Annealing (SA) algorithm is the better than other algorithms for small-scale, medium-scale, and large-scale problems. As such, based on the Gap value of algorithms, the results of LINGO software shows that it reveals a better outputs in comparison with meta-heuristic algorithms in small-scale and simulated annealing algorithm is better than other algorithms in large-scale and medium-scale problems. Finally, a set of computational results and conclusions are presented and analyzed.
- انتشار مقاله: 14-01-1397
- نویسندگان: Mohammad Bagher Fakhrzad,F. Goodarzian,A. M. Golmohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dentistry, Shiraz University of Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: Statement of Problem: Plaque control and its instruction is an important part of dental treatments which guarantees the long term success of the periodontal and dental care.Purpose: The purpose of this research was to evaluate the efficiency of the oral hygiene instruction given to the patients on the amount of awareness and improving their attitude and practice.Method and Material: For this purpose, a number of 100 patients were selected randomly and instructed oral hygiene methods. The patients filled out a questionnaire including 14 questions derived from OHI-S questionnaire of WHO at the beginning of the study and at the intervals of one and two weeks and 1-month. The plaque index of all the patients was measured by an examiner on the base of O’Leary plaque index. After comparing the pre and post oral health questionnaires, changes in the rate of attitude, awareness and practice of patients were analyzed with paired t-test.Results: One month after oral hygiene instruction, the patients’ awareness and attitude increased by 46% ( p = 0.021) and 123% ( p = 0.018) respectively. The plaque index decreased by 43.27% ( p = 0.018). All of the parameters showed a significant difference from baseline ( p <0.05).Conclusion: The results of this study showed that repeated oral hygiene instruction makes a significant improvement on the amount of awareness, attitude and practice of patients in relation to plaque control.Key words: Oral hygiene instruction, Plaque index, Awareness, Attitude, Practice
- انتشار مقاله: 15-07-1392
- نویسندگان: A. Shirmohammadi,M. Faramarzie
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dentistry, Shiraz University of Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: Statement of Problems: Numerous evidence indicates the deteriorating effects of obesity on body organs and its role in predisposition to systemic diseases such as diabetes. On the other hand, diabetes has been recognized as a risk factor for periodontal breakdown.Purpose: This study aimed to determine the relationship between obesity and periodontal diseases. The second aim was to clarify if periodontal diseases make the individuals prone to impaired glucose tolerance.Materials and Method: A total of 166 patients (age 35- 59 years) who sought dental care in Tabriz Dental Faculty were recruited in this study. Eighty three people had periodontitis in accordance with NHANES III index (test group) and the remaining who did not have periodontal disease served as the control group. The body weight (BW), height and waist circumference (WC) were measured in both of the study groups followed by fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT). Data were analyzed by student t-test and Chi-Square followed by calculating the odds ratio and Spearman correlation.Results: All of the studied variables expressed a higher score in the test group than the control one ( p < 0.05). Evaluation of the correlation of obesity (OB), overweigh (OW), WC, and impaired glucose tolerance (IGT) with periodontal disease severity, revealed the highest correlation between OB ( r =1 and p <0.001) and the lowest between OW (r = 0.4 and p =0.07). Regarding the association of OB, WC and OW with IGT among women, the strongest association was found in OB (odds ratio, 6.5; 95% CI, 1.26- 23.6) and the weakest was in OW (odds ratio, 0.43; 95% CI, 0.07-2.6). These associations were similar among the males and the highest was between OB (odds ratio, 5; 95% CI, 0.82-19.41) VS. The weakest that was observed in OW (odds ratio, 0.39; 95% CI, 0.07-2.17).Conclusion: The association of obesity and periodontal disease is stronger than that with impaired glucose test. This may be attributed to different mechanisms involved in relationship between periodontal disease, obesity and diabetes.Key words: Obesity, Periodontal disease, Diabetes mellitus, Glucose tolerance
- انتشار مقاله: 18-08-1392
- نویسندگان: MT. Chitsazi,R. Pourabbas,A. Shirmohammadi,MH. Vatan Khah MH.
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dentistry, Shiraz University of Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: Statement of Problem: Due to the limitations of mechanical plaque control methods, the use of chemical methods have been recommended, and Chlorhexidine has been shown to be the gold standard mouth-rinse.Purpose: The aim of this study was to compare the effect of two herbal mouth-rinses with each other, and with Chlorhexidine on some periodontal indices.Materials and method: In this double-blinded interventional study, 30 male dental students were divided into three equal groups. Before and after using of the two herbal and one chemical mouth-rinses (Matrica, Persica, and Chlorhexidine) periodontal indices including plaque, gingival, and tooth staining were measured and recorded. All samples consumed the three mouth-rinses in two week intervals. Data were analyzed using Wilcoxon test for evaluation of dependent variables in each group, and ANOVA for dependent variables between the three mouth-rinses.Results: The three mouth-rinses used in this study (Matrica, Persica, and Chlorhexidine) caused reduction in plaque index by 30.589.22%, 19.448.43% and 19.628.7%, respectively. All the mouth-rinses decreased the plaque index but the reduction was more prominent with Chlorhexidine (p<0.05). Also, Chlorhexidine caused more gingival index reduction in comparison with Matrica and Persica (p<0.05). Herbal mouth-rinses caused small areas of staining but Chlorhexidine increased stain index value by its extension and intensity. The difference between the two herbal mouth-rinses was not statistically significant, while the difference was significant in comparison with the chemical mouth-rinse (p<0.05).Conclusion: As the extension and intensity of staining caused by Chlorhexidin as a chemical agent was significantly more than the herbal mouth-rinses, also its effect on plaque and gingival indices was more. So, the benefits and side effects of each mouth-rinse should be considered in their clinical application.Key words: Herbal mouth-rinse, Chemical mouth-rinse, Periodontal indices
- انتشار مقاله: 09-09-1392
- نویسندگان: M. Chitsazi,A. Shirmohammadi,E. Balayi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dentistry, Shiraz University of Medical Sciences
- نوع مقاله: Journal Article
- کلمات کلیدی:
- چکیده:
- چکیده انگلیسی: Statement of Problems: Bacterial endocarditis is a rare disease that resulted to the death and morbidity in children and young people about 55% to 65%. Since many dental treatments can create the bacterial endocarditis, thereby antibiotic prophylaxis with appropriate treatment modaliteis by dentist is very important and necessary for prevention.Purpose: The purpose of this study was to investigate the knowledge of a group of Iranian dentists about antibiotic prophylaxis guidelines for bacterial endocarditis.Materials and method: In this descriptive and cross sectional study, the population under consideration were the dentists participated in the fifth International Congress of Pediatric Dentistry (summer 2006), selected with simple sampling methods. The data was collected by questionnaires completed by the selected dentists. For data analysis, t-test and spierman with the SPSS 13.5 program were used.Results: Participted in this study were 85 dentists. The results showed that, previous bacterial endocarditis, rheumatic heart disease and mitral valve prolapse with valvular regurgitation, were diagnosed by the dentists to be the most common situations which need antibiotic prophylaxis. Also the most common treatment procedures for which antibiotic prophylaxy is needed, were tooth extraction and subginginval cord respectively. More than half of the dentists (68.3%) prefer use of amoxycillin as a prophylactic medicament. Overall mean knowledge score of the dentists was 37.4±14.3.Conclusion: Due to the present findings to improve knowledge and attitude, it seems necessary for dentists to take participate in educational programs on the bacterial endocarditis.Key words: Knowledge, Endocarditis, Prophylaxis, Antibiotic, Children
- انتشار مقاله: 10-09-1392
- نویسندگان: M. Hashemipour,Kh. Baharlooei,A. Mohammadi
- مشاهده