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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Nanomedicine Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: Cardiovascular diseases,3D printing,Artificial vessel,Flexible polymer,Bioceramic
- چکیده:
- چکیده انگلیسی: Objective(s): Cardiovascular diseases (CVDs) are the leading cause of mortality in the elderly. A common medical procedure for the treatment of CVDs is the replacement of the blocked or narrowed arteries, which is currently the optimal vascular transplant associated with autograft transplantation. In general, the saphenous veins and radial arteries in the mammary gland are considered to be the selective vessels for vascular substitution. In many cardiac patients, artificial blood vessels (ABVs) are not used for several reasons, including the age of the patient, small size of the veins, previous impressions, and abnormally. Therefore, the consideration of vascular substitute demands is inevitable, especially regarding vascular transplantation with very small diameters and availability of proper alternatives. The present study aimed to develop a novel artificial bio-composite blood vessel using polymer-reinforced and bioceramic nanoparticles.
Materials and Methods: The biomechanics and chemical properties of artificial vessels have been investigated to be used in coronary artery bypassing in atherosclerosis as a soft tissue engineering procedure. In this study, thermoplastic polyurethane (TPU) composed of nanocrystalline hydroxyapatite (HA) nanopowder was prepared using the extrusion technique to construct the ABVs. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the optimum specimen. An important feature of the ABVs was the ability to find the elastic modulus, wettability, and porosity of the veins, which were assessed by fused deposition modeling and 3D printing.
Results: The sample containing five wt% of HA had superior mechanical and biological features over the pure sample.
Conclusion: According to the results, the narrowed arteries composed of TPU composite with nanocrystalline HA nanopowder had proper chemical stability and mechanical characteristics.- انتشار مقاله: 31-02-1398
- نویسندگان: Saeid Esmaeili,Maryam Shahali,Alireza Kordjamshidi,Zahra Torkpoor,Farshad Namdari,Saeed Saber- Samandari,Mazyar Ghadiri Nejad,Amirsalar Khandan
- مشاهده
- جایگاه : پژوهشی
- مجله: Nanomedicine Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: Cardiovascular diseases,3D printing,Artificial vessel,Flexible polymer,Bioceramic
- چکیده:
- چکیده انگلیسی: Objective(s): Cardiovascular diseases (CVDs) are the leading cause of mortality in the elderly. A common medical procedure for the treatment of CVDs is the replacement of the blocked or narrowed arteries, which is currently the optimal vascular transplant associated with autograft transplantation. In general, the saphenous veins and radial arteries in the mammary gland are considered to be the selective vessels for vascular substitution. In many cardiac patients, artificial blood vessels (ABVs) are not used for several reasons, including the age of the patient, small size of the veins, previous impressions, and abnormally. Therefore, the consideration of vascular substitute demands is inevitable, especially regarding vascular transplantation with very small diameters and availability of proper alternatives. The present study aimed to develop a novel artificial bio-composite blood vessel using polymer-reinforced and bioceramic nanoparticles.
Materials and Methods: The biomechanics and chemical properties of artificial vessels have been investigated to be used in coronary artery bypassing in atherosclerosis as a soft tissue engineering procedure. In this study, thermoplastic polyurethane (TPU) composed of nanocrystalline hydroxyapatite (HA) nanopowder was prepared using the extrusion technique to construct the ABVs. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate the optimum specimen. An important feature of the ABVs was the ability to find the elastic modulus, wettability, and porosity of the veins, which were assessed by fused deposition modeling and 3D printing.
Results: The sample containing five wt% of HA had superior mechanical and biological features over the pure sample.
Conclusion: According to the results, the narrowed arteries composed of TPU composite with nanocrystalline HA nanopowder had proper chemical stability and mechanical characteristics.- انتشار مقاله: 31-02-1398
- نویسندگان: Saeid Esmaeili,Maryam Shahali,Alireza Kordjamshidi,Zahra Torkpoor,Farshad Namdari,Saeed Saber- Samandari,Mazyar Ghadiri Nejad,Amirsalar Khandan
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Smart Electrical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: optimization,state estimation,Power quality monitor placement,Measurement channel,Depth of unobservability
- چکیده:
- چکیده انگلیسی: Finding minimum number of connecting lines is as important as locating power quality monitors (PQMs) for full observability of power system. Therefore, a PQM placement method should determine both optimum buses and lines, since utilities can make better decisions for monitoring of power system with this information. This paper attempted to propose a new method to locate the PQMs at various unobservability depths. In this method, the problem of placement is solved on three levels, taking into account the limited number of channels required for measuring each bus. At the first level of this method, the optimum combination of zero injection buses (ZIBs) is achieved. At the second level, different combinations of connecting lines are produced, while the third level determines the best location of monitors in different nuobservability depths. In addition, the third level identifies the critical buses and their effects on the number and location of monitors. Moreover, the best location for installing monitors and the number of channels required by equipment in each depth will be specified. The results of applying the new method on 14-bus IEEE network demonstrate the ideal performance.
- انتشار مقاله: 22-04-1397
- نویسندگان: Leila Kamyabi,Saeid Esmaeili
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Advanced Design and Manufacturing Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: finite element analysis,Bone Scaffold,Bio-Nanocomposites,Computational and Laboratory Analysis,hydroxyapatite
- چکیده:
- چکیده انگلیسی: In Osteoporosis, bone mechanical strength decreases and as a result, the risk of bone fracture increases. Osteoporosis is also referred as a "silent illness" since it usually develops asymptomatic until it breaks a long bone, like the femur. In recent years, porous scaffolds have been utilized to repair damaged bone tissue. For bone tissue engineering, synthetic scaffolds should have acceptable mechanical properties, in addition to the required biological properties. In this regard, the finite element simulation is used to predict the mechanical properties of porous bone scaffolds as one of the most common methods for reducing the experimental tests, because the acquisition of mechanical properties of such scaffolds is very time-consuming and expensive. Due to the widespread use of hydroxyapatite (HA) in the manufacture of bone scaffold composites, the mechanical properties of HA-wollastonite scaffold composites are obtained by laboratory tests and finite element methods. Comparison of the simulation of finite element analysis (FEA) and the experimental results indicate the success of the FEA simulation. In conclusion, new finding satisfied expectations as being suitable for mechanical and biomaterial aspect of a porous scaffold which is proven by laboratory tests and FEA simulations. Due to that fact, the result of this study can be employed to obtain scaffolds well-suited for bone implementations.
- انتشار مقاله: 23-02-1398
- نویسندگان: Sayed Alireza Hashemi,Saeid Esmaeili,Mazyar Ghadirinejad,Saeed Saber-Samandari,Erfan Sheikhbahaei,Alireza Kordjamshidi,Amirsalar Khandan
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Advanced Design and Manufacturing Technology
- نوع مقاله: Journal Article
- کلمات کلیدی: Incremental Forming,Formability,3D Printer,Orthopedic Appliance
- چکیده:
- چکیده انگلیسی: Single point incremental forming (SPIF) and fused deposition modeling 3D printing (FDM) are two methods of rapid prototyping. Each method has its own pros and cons. using SPIF method can provide an accurate forming process to shape sheets fabricated by 3D printing with their special characteristics. In this study, single-point incremental forming of Poly Lactic Acid (PLA) sheets fabricated by FDM 3D printer was investigated by experiments. The formability process was evaluated by two different experiments. In the first experiment, a lubricant was used at ambient temperature and SPIF was investigated and for the second experiment hot air and lubrication were employed to achieve better formability. In addition, the effects of sheet thickness and strategy of layering of printed sheets by FDM were also studied on SPIF formability. The results showed that the incremental forming of printed PLA sheets in hot air is a more successful state to produce dome shapes parts and ruptures are less and this forming method can be used for some applications such as making partial curve of skull as a medicine solution in surgeries. Also, it was shown that the best layering strategy to print the PLA sheets used for better forming of SPIF is triangular pattern strategy against with rectangular strategy. It was found that thickness of 2mm printed sheet has better formability and less rupture versus 3mm of thickness.
- انتشار مقاله: 18-12-1397
- نویسندگان: Saeid Esmaeili,Mohsen Loh-Mousavi,Sayyed Ali Eftekhari
- مشاهده