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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Gas Processing Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: Artificial Neural Network,Hydrate Formation Temperature,AUT Correlation
- چکیده:
- چکیده انگلیسی: Gas hydrates are a costly problem when they plug oil and gas pipelines. The best way to determine the HFT and pressure is to measure these conditions experimentally for every gas system. Since this is not practical in terms of time and money, correlations are the other alternative tools. There are a small number of correlations for specific gravity method to predict the hydrate formation. As the hydrate formation temperature is a function of pressure and gas gravity, an empirical correlation is presented for predicting the hydrate formation temperature. In order to obtain a new proposed correlation, 356 experimental data points have been collected from gas-gravity curves. This correlation is programmed and assessed with respect to its capabilities to match experimental data published in the literature under varying system conditions (i.e. temperature, pressure, and composition).The SPSS software has been employed for statistical analysis of the data. In order to establish a method to predict the hydrate formation temperature, a new neural network has also been developed with the BP(Back Propagation) method. This neural network model enables the user to accurately predict hydrate formation conditions for a given gas mixture, without having to do costly experimental measurements.
- انتشار مقاله: 26-03-1395
- نویسندگان: Hamidreza Yousefi,Ebrahim Shamohammadi,Ehsan Khamehchi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Industrial Strategic Management
- نوع مقاله: Journal Article
- کلمات کلیدی: vehicle routing problem,Time window,stochastic demand,Competitive demand
- چکیده:
- چکیده انگلیسی: In this study, a combination of different vehicle routing problems called Vehicle Routing Problem with a Time Window and Stochastic Demand has been examined. The difference between previous papers and this paper is that in our problem, the competitors compete with each other to meet the demands of customers in a specific industry. It seems that these problems occur in real life as well. In most real environmental problems, customers materialize their utmost demand for a vehicle that reaches on time and sooner than other competitors. The target function is to maximize the profit earned through the sale of goods to customers. Solving the research model in several trivial problems has been made precisely by using GAMZ Software.
In this study, a combination of different vehicle routing problems called Vehicle Routing Problem with a Time Window and Stochastic Demand has been examined. The difference between previous papers and this paper is that in our problem, the competitors compete with each other to meet the demands of customers in a specific industry. It seems that these problems occur in real life as well. In most real environmental problems, customers materialize their utmost demand for a vehicle that reaches on time and sooner than other competitors. The target function is to maximize the profit earned through the sale of goods to customers. Solving the research model in several trivial problems has been made precisely by using GAMZ Software.- انتشار مقاله: 21-02-1399
- نویسندگان: Behzad Ghasemi,Ebrahim Mohammadipirlar,Amir Sadeghi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Advances in Environmental Health Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Doping,Nanocomposite,Graphene
- چکیده:
- چکیده انگلیسی: Zinc oxide (ZnO) is a promising metal oxide semiconductor with various applications, especially in the photocatalytic destruction of environmental pollutants. However, this nanoparticle has some limitations, such as poor dispersion, aggregation, and a wide energy gap. As such, the doping of metal oxide semiconductor has been strongly recommended. Addition of manganese (Mn) has proven effective in resolving these issues. On the other hand, addition of carbon-based materials (e.g., graphene) could improve the stability and photocatalytic efficiency of ZnO. Graphene oxide acts as an electron- transport and electron-acceptor agent, controlling the charge transfer in the ZnO/graphene nanocomposite interface. The present study aimed to synthesize manganese-doped graphene/ZnO nanocomposites and determine its structural properties. Some techniques were employed to characterize the prepared composites, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), dynamic light scattering (DLS), and zeta potential analysis. According to the FTIR analysis, the peak in the range of 3467 cm-1 was due to the presence of zinc groups in the graphene structure, and the peak observed at 439 cm-1 also indicated the presence of Mn in the compound. Furthermore, the results of AFM analysis showed that graphene to be a layered sheet with the mean thickness of 1.48 nanometers. The results of the DLS analysis showed the mean diameter of GO-ZnO-Mn to be 37 nanometers, which reduced after graphene modification. According to the findings, addition of Mn and ZnO to graphene could effectively result in doping.
- انتشار مقاله: 31-03-1397
- نویسندگان: Mahnaz Mohammadi,Afshin Maleki,Shiva Zandi,Ebrahim Mohammadi,Esmail Ghahramani
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Advances in Environmental Health Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Doping,Nanocomposite,Graphene
- چکیده:
- چکیده انگلیسی: Zinc oxide (ZnO) is a promising metal oxide semiconductor with various applications, especially in the photocatalytic destruction of environmental pollutants. However, this nanoparticle has some limitations, such as poor dispersion, aggregation, and a wide energy gap. As such, the doping of metal oxide semiconductor has been strongly recommended. Addition of manganese (Mn) has proven effective in resolving these issues. On the other hand, addition of carbon-based materials (e.g., graphene) could improve the stability and photocatalytic efficiency of ZnO. Graphene oxide acts as an electron- transport and electron-acceptor agent, controlling the charge transfer in the ZnO/graphene nanocomposite interface. The present study aimed to synthesize manganese-doped graphene/ZnO nanocomposites and determine its structural properties. Some techniques were employed to characterize the prepared composites, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), dynamic light scattering (DLS), and zeta potential analysis. According to the FTIR analysis, the peak in the range of 3467 cm-1 was due to the presence of zinc groups in the graphene structure, and the peak observed at 439 cm-1 also indicated the presence of Mn in the compound. Furthermore, the results of AFM analysis showed that graphene to be a layered sheet with the mean thickness of 1.48 nanometers. The results of the DLS analysis showed the mean diameter of GO-ZnO-Mn to be 37 nanometers, which reduced after graphene modification. According to the findings, addition of Mn and ZnO to graphene could effectively result in doping.
- انتشار مقاله: 31-03-1397
- نویسندگان: Mahnaz Mohammadi,Afshin Maleki,Shiva Zandi,Ebrahim Mohammadi,Esmail Ghahramani
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Pathology
- نوع مقاله: Journal Article
- کلمات کلیدی: Lacrimal sac,Nasolacrimal Duct,Epiphora,Dacryocystorhinostomy
- چکیده:
- چکیده انگلیسی: Background and Objectives: External dacryocystorhinostomy (DCR) is the method of choice to treat nasolacrimal duct (NLD) obstruction and the other approaches are compared with it, with a failure rate of 4% to 13%. The current study aimed to assess the causes of failure in external DCR by postoperative endoscopic and pathological evaluation.
Methods: The current retrospective cross sectional study followed-up113 patients with external DCR and silicone intubation for three months. Silicone tubes were removed after the third months. Failure was confirmed based on the clinical findings and irrigation test. Paranasal sinus computed tomography (CT) scanning, and endoscopic and pathological evaluations were performed in the failed cases.
Results: Totally, 113 patients underwent external DCR. The patients included 71 females and 42 males. The mean age of the patients was 55.91 years; ranged from 18 to 86. Epiphora was the most common complaint before surgery (90.3%). Clinically, epiphora continued in 17 cases (15%), of which 94.11% had at least one sinus CT abnormality and 82.35% had at least one endoscopic abnormality. The most common endoscopic findings were deviated septum (70.6%), scar tissue (52.94%), concha bullosa (46.9%), septal adhesion (47.05%), enlarged middle turbinate (41.2%), and sump syndrome (11.7%). The failure was significantly associated with the chronicity of the initial symptoms (P-value=0.00). Pathologically, there were significant relationship amongst the failure rate, scar formation, and allergic rhinitis (P-values =0.00 and <0.05, respectively).
Conclusion: Preoperative endonasal evaluation and consultation with an otolaryngologist can improve surgical outcomes and help to have a better conscious to intranasal abnormalities before external DCR surgery.- انتشار مقاله: 30-11-1394
- نویسندگان: Hassan Ghasemi,Sajedeh Asghari Asl,Mohammad Ebrahim Yarmohammadi,Farhd Jafari,Pupak Izadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Pathology
- نوع مقاله: Journal Article
- کلمات کلیدی: Goblet cell,Lacrimal Duct Obstructions,Inflammations
- چکیده:
- چکیده انگلیسی: Background and Objectives: Primary acquired nasolacrimal duct obstruction (PANDO) is a common ocular problem. Clinical presentation can range from simple tearing to a life-threatening condition. The exact pathophysiology of obstruction is not completely understood. In this study, therelationship between PANDO and nasal mucosal goblet cells was investigated. Materials & Methods: In this case-control study, 15 subsequent patients with PANDO were enrolled. Patients were operated with endoscopic dacryocyctorhinostomy. A small piece of nasal mucosal biopsy sample was obtained from inferior turbinate. The samples were prepared and stained for mucin. Goblet cells were counted in the specimens. The results were compared with the nasal mucosa of 15 normal persons who were underwent rhinoplasty surgery as control group. Data were analyzed by SPSS version 16 software and were assessed using t-test, analysis of variance, and Pearson correlation test. Results:In patients group, 13 cases (86.7%) were female and 2 cases (13.3%) were male. The mean age was 42.4±14.3 years (range, 23-68 years). In control group, 9 persons (60%) were female and 6 persons (40%) were male. The mean age was 35.5±12.1 (range, 19-58 years) (P>0.05). All patients had epiphora, and 66.7% of patients had purulent discharge. Duration of symptoms ranged from 1 year to 12 years. The number of goblet cells of the nasal mucosa in patient group was significantly higher than the control group (P<0.001). Inflammation was not related to goblet cell numbers Conclusion: According to findings of this study, goblet cells have important role in inflammatory process and perhaps obstruction in nasolacrimal duct.
- انتشار مقاله: 29-06-1393
- نویسندگان: Hassan Ghasemi,Mohammad Ebrahim Yarmohammadi,Farhad Jafari,Pupak Izadi,Mahdi Faryadras
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Pathology
- نوع مقاله: Journal Article
- کلمات کلیدی: PCR,Helicobacter pylori,chronic sinusitis,Urease Test
- چکیده:
- چکیده انگلیسی: Objective: To investigate the presence of Helicobacter pylori in sinonasal mucosa of patients with chronic sinusitis Design: A prospective case-control study Materials and methods: Mucosal specimens were collected from the mid-third middle meatus and lateral side of mid-cornea. H. pylori has been investigated using PCR after DNA extraction and urease test. Results: H. pylori was not found in any of the sample taken from both groups (case and control patients). Conclusion: This is the first reported study to investigate the presence of H. pylori in sinonasal mucosa in Iran. In this study, H. pylori was not determined in these sites, although its possible presence could not be excluded. Thus, further investigation on more patients and application of sensitive diagnostic techniques are recommended.
- انتشار مقاله: 06-07-1393
- نویسندگان: Mohammad Ebrahim Yarmohammadi,Horieh Saderi,S.Hadi Saghelaini,Jamshid Narenjkar J
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Immunology
- نوع مقاله: Journal Article
- کلمات کلیدی: Familial Hemophagocytic Lymphohistiocytosis,Perforin gene,Cytotoxic T lymphocytes
- چکیده:
- چکیده انگلیسی: Perforin gene (PRF1) mutations have been reported in 20-30% of patients with familial hemophagocytic lymphohistiocytosis (FHL), an immune disorder of infancy and early childhood. Cytotoxic T and natural killer (NK) cell activities are remarkably reduced or ab-sent in FHL patients. We report the first cases of familial hemophagocytic lymphohistiocy-tosis in an Iranian family with two siblings. Exons 2 and 3 of the PRF1 gene were analyzed by polymerase chain reaction (PCR) amplification and direct sequencing. Perforin gene mu-tation(s) were detected in none of the cases. The result of our study indicates that not much evidence is present concerning a correlation between perforin gene defects and familial he-mophagocytic lymphohistiocytosis etiology in these cases.
- انتشار مقاله: 17-05-1395
- نویسندگان: Hamid Galehdari,Ebrahim Mohammadi,Behnaz Andashti,Ali Naderi,Mohammad Ali Molavi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Genetics and Plant Breeding
- نوع مقاله: Journal Article
- کلمات کلیدی: diabetes,Agrobacterium tumefaciens,Gene transfer,Pleurotus ostreatus,Pro-insulin
- چکیده: انتقال ژنهای خارجی به قارچهای خوراکی با استفاده از Agrobacterium tumefaciens روشی متداول در مهندسی ژنتیک محسوب میشود. برای درمان دیابت نوع یک به طور عمده از انسولین نوترکیب استفاده میشود. تولید پروانسولین در قارچهای خوراکی میتواند سبب تسهیل در تحویل خوراکی این دارو شود. در این مطالعه از باکتری A. tumefaciens برای انتقال و بیان ژن ترکیبی زیر واحد سم وبا و پروانسولین انسانی (CTB-Pins) در قارچ صدفی Pleurotus ostreatus استفاده شد. برای اینمنظور ناقل بیانی pCAMBIA1304 حاوی ژن CTB-Pins تحت کنترل پیشبرنده gpd قارچ صدفی طراحی و با استفاده از روش انتقال ژن مبتنی بر A. tumefaciens به قارچ P. ostreatus منتقل شد. بهینهسازی شرایط انتقال ژن و کشت بافت از عوامل مهم در تولید قارچ تراریخت بهشمار میآیند. برای اینمنظور، شرایط همکشتی قارچ و باکتری، سویه اگروباکتریوم و غلظت آن مورد مطالعه قرار گرفت. انتقال ژن CTB-Pins به قارچ صدفی با استفاده از آزمون PCR تایید گردید. انتقال موفق ژن به قارچ صدفی بیانگر روشی مفید برای تولید پروانسولین انسانی در قارچهای خوراکی میباشد.
- چکیده انگلیسی: Transferring foreign genes into mushroom mediated by Agrobacterium tumefaciens is a standard technique in genetic engineering. Recombinant human insulin has been greatly used in the treatment of type I diabetes. The production of edible mushroom derived insulin should facilitate oral delivery. In this study we used the Agrobacterium tumefaciens mediated transformation method for the transfer and expression of the cholera toxin-B subunit (CTB) fused with human pro-insulin (Pins) in the edible oyster mushroom, Pleurotus ostreatus. The binary vector pCAMBIA1304 harboring CTB-Pins gene driven by the P. ostreatus gpd promoter was constructed and introduced into P. ostreatus via Agrobacterium tumefaciens mediated transformation. Optimization of gene transformation and tissue culture conditions is one of the most important issues in transgenic mushroom production. For attaining optimized conditions, the effects of co-cultivation conditions, Agrobacterium strains and the concentration of Agrobacterium cell suspensions were studied. Integration of CTB-Pins into mushroom genome was confirmed by PCR. The successful transformation to oyster mushroom suggests that the proposed modified transformation system is apparently useful for the production of human pro-insulin in these edible mushrooms.
- انتشار مقاله: 01-11-1391
- نویسندگان: Sedigheh Fabriki-Ourang,Mokhtar Jalali-Javaran,Ebrahim Mohammadi-Goltapeh,Hooshang Alizadeh,Hossein Honari
- مشاهده
- جایگاه : پژوهشی
- مجله: Asian Pacific Journal of Cancer Prevention
- نوع مقاله: Journal Article
- کلمات کلیدی: Helicobacter pylori,Gastric cancer,sirt1,sirt2,Tumor grade
- چکیده:
- چکیده انگلیسی: Introduction: The World Health Organization has categorized Helicobacter pylori as a carcinogen for gastric
cancer, which causes human mortality worldwide. A number of studies have shown that H. pylori affects cell signaling
in gastric epithelial cells and changes the expression of some proteins such as proinflammatory cytokines. Bacterial
infections may alter sirt1 and sirt2 genes expression in inflammatory tissues and cancer cells. In this study, sirt1 and
sirt2 genes expression in gastric cancers was surveyed with reference to H. pylori status. Methods: Stomach biopsies
were collected from 50 gastric cancer patients, 25 H. pylori-positive and 25 H. pylori-negative as determined by the
urea rapid test. Tumor grade was determined by a pathologist. After total RNA extraction from gastric cancer biopsy
samples and cDNA synthesis, sirt1 and sirt2 genes expression levels were determined by Real Time PCR and ΔΔCT
methods. Results: There was no statistically significant link between H. pylori infection and sirt1 (P<0.899) and sirt2
(P<0.169) genes expression in gastric epithelial cells. However, pathologic findings showed that there is a statistically
significant relationship between sirt1 gene expression and the tumor grade (P<0.024). Discussion: A statistically
significant association was found between sirt1 gene expression and tumor grade of gastric cancers that could be due
to effects on progression of cancer cells infected with H. pylori.- انتشار مقاله: 20-02-1396
- نویسندگان: Saman Mohammadi Saravle,Manouchehr Ahmadi Hedayati,Ebrahim Mohammadi,Farshad Sheikhesmaeili,Bahram Nikkhoo
- مشاهده