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81.
Ghaemi Seyedeh Golsana Ahmadpour Iman Ardebili Mehdi Farbeh Hamed 《The Journal of supercomputing》2019,75(7):3945-3974
The Journal of Supercomputing - Emerging non-volatile memories (NVMs) are known as promising alternatives to SRAMs in on-chip caches. However, their limited write endurance is a major challenge... 相似文献
82.
Seyed Hossein Rajabnejad Ahad Mokhtarzadeh Khalil Abnous Seyed Mohammad Taghdisi Mohammad Ramezani 《Drug development and industrial pharmacy》2018,44(6):982-987
Melittin, a small water-soluble cationic amphipathic α-helical linear peptide, consisted of 26 amino acids, is the honeybee venom major constituent. Several reports have proved the lytic and apoptotic effects of melittin in several cancerous cell lines. In this study, we aimed to fabricate an AS1411 aptamer–melittin to specifically deliver melittin to nucleolin positive cells (A549). Melittin was covalently attached to antinucleolin aptamer (AS1411) and its toxicity in A549 (nucleolin positive) and L929 (nucleolin negative) was studied using MTT and Annexin V flow cytometry methods. Aptamer–melittin conjugate formation was confirmed by gel electrophoresis. Hemolytic effect of aptamer–melittin conjugate was compared to melittin alone. The aptamer–melittin conjugate showed efficient cell uptake and was more cytotoxic in A549 cells than melittin (p?.001). This complex was less toxic in control cells. Competitive inhibition assay confirmed that aptamer–melittin complex delivery occurred through receptor-ligand interaction on the cell surface. Moreover, aptamer–melittin showed a significantly less hemolytic activity as compared with free melittin. This study showed that melittin could be specifically delivered to A549 cells when it was covalently conjugated to antinucleolin aptamer (AS1411) in vitro. This system can reduce the cytotoxic effects of melittin on cells with no nucleolin receptor overexpression which comprise most of normal cells such as L929 cells. 相似文献
83.
Here we are aimed to unravel the effects of CC functionality and molecular weight of the rubber on the final properties of poly1-hexene-based high impact polystyrenes (HIPS). In this regard, various HIPS samples were synthesized by free radical polymerization of styrene in the presence of different weight fractions of various poly1-hexene-based impact modifiers including: (i) high molecular weight poly1-hexene (PHex), (ii) low molecular weight poly1-hexene (Olig), and (iii) 1-hexene/1,5-hexadiene copolymer (Copolym). Results showed that by increasing CC functionality from PHex to Oligm and Copoly, the degree of grafting increases which has its influence on the mechanical, thermal and morphological perspectives of the synthesized HIPSs. Besides CC unsaturation degree, the effect of rubber molecular weight on the final HIPS properties was studied as well. According to the results, molecular weight has significant effect on the final HIPS performance, too. Finally, our obtained results suggest new HIPS/Copolym sample as the one with the highest mechanical and thermal properties which is comparable well with commercial HIPS/polybutadiene grades. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47169. 相似文献
84.
In knowledge-based system (KBS) applications where the number of facts in the knowledge base is very large, the amount of information that is needed for effective explanation support can become too voluminous to be stored in main memory. The authors present an approach to modeling and managing the information needed for explanation rising a relational database. It is shown how different types of explanation can then be produced by appropriate queries on this database. The authors formulate representative queries for some major types of explanation using ESQL, an extension of structured query language (SQL) 相似文献
85.
Elie Ahad 《应用聚合物科学杂志》1973,17(2):365-375
A difunctional hydroxyl-terminated polybutadiene (sample A) was characterized by light scattering (LS), vapor pressure osmometry (VPO), and gel permeation chromatography (GPC). Sample A was then esterified, and the product (sample B) was also characterized. Light-scattering measurements were carried out in different solvents (some were theta solvents for polybutadiene), and the results were corrected for anisotropy. Values of Mn (3100) and Mw (8000) determined respectively by VPO and LS for samples A and B were similar to those computed by GPC using two sets of columns of different resolution. The value of 2.3 found for the polydispersity index Mw/Mn is higher than the value which is usually reported by other workers (ca. 1.3 to 1.7) for functionally terminated polybutadienes. 相似文献
86.
S.S. Madaeni M. Moahamadi Sarab Badieh V. Vatanpour N. Ghaemi 《Polymer Engineering and Science》2012,52(12):2664-2674
Introducing inorganic nanoparticles into the structure of polymeric membranes is an interesting approach for the enhancement of physical, chemical, and separation properties of the membranes. In this article, the performance of a two‐layer nanocomposite membrane for gas separation was studied. Three different methods for embedding titanium dioxide (TiO2) nanoparticle were employed for the membrane preparation. The techniques include blending TiO2 in the polydimethylsiloxane (PDMS) coating layer, blending TiO2 in the polyethersulfone (PES) support and dip coating of PES support with TiO2 accompanied by PDMS coating. The aim of the current research was finding the optimum technique for introducing TiO2 into the membrane to obtain superior performance for gas separation. The results indicated that PES support containing TiO2 nanoparticles possessed favorable effect on gas separation capability. The optimum performance was obtained by PDMS‐coated membranes prepared with 7 wt% TiO2‐embedded PES support. Carbon dioxide (CO2) permeance, CO2/nitrogen, and CO2/methane selectivity were obtained as 188.7 GPU, 8.6, and 3.4, respectively. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers 相似文献
87.
Alireza Khoshraftar Fatemeh Yazdian Hamid Rashedi Roza Vaez Ghaemi Zakie Alihemmati 《国际聚合物材料杂志》2018,67(17):987-995
Tissue engineering is a new approach for regeneration of damaged tissues. The current clinical methods such as autograft and allograft transplantation are not effective for repairing bone damages, mainly due to the limited available sources and the donor-site side effects. In this research, the nanocomposite poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/nano hydroxyapatite (nHA) scaffolds with different nHA ratios for bone regeneration were utilized. The diameter and porosity of scaffolds were approximately 200?nm and 74%, respectively. The degradability test of the scaffolds suggests a low degradation rate with total degradation of 30% after 3 months. Cytotoxicity result showed that cultured osteoblast cells (MC3T3) on nanocomposite scaffolds had superiority in terms of higher proliferation and attachment in comparison with PHBV scaffold. The protein expression of alkaline phosphatase illustrated that nanofibrous scaffold containing hydroxyapatite had the highest alkaline phosphatase activities as a result of better proliferation. These results recommend that PHBV/nHA scaffolds are suitable candidates for bone tissue engineering. 相似文献
88.
The mass transfer parameters of both gas and liquid phases affect the mass transfer flux of CO2 in absorption processes. In this study, an accurate correlation is proposed to calculate the CO2 mass transfer flux in an absorption-reactive process by methyldiethanolamine (MDEA) solution using the Buckingham π theorem. The various parameters include film parameter, CO2 loading, concentration ratio, partial-to-total pressure ratio, film thickness ratio, and diffusion ratio which are incorporated in the model. An average absolute relative error of 4.4 % for the calculation of mass transfer flux was stated. 相似文献
89.
ABSTRACTDuring Supersolidus Liquid Phase Sintering the viscosity of beams affects the deflection level, thus in sintering practice also the tendency to distortion. Although the deflection value increases with decreasing viscosity, a concentration gradient from surface to centre of samples may neutralise the effect of viscosity. In this paper, the deflection behaviour of Cu-28Zn beams, manufactured from prealloyed powder, at various temperatures and times ranging from 910 to 950°C and 0–90?min, respectively, was studied. The midpoint deflection was measured by the in situ bending images. To better understand the deflection behaviour, experimental results were mathematically modelled using general deflection equations. To obtain further information, microstructural studies were performed using optical and scanning electron microscopy. It is concluded that zinc evaporation influences the chemical composition and generates a thin solid layer around the sample resulting in a parabolic deflection behaviour with temperature and non-linear with time. 相似文献
90.
Sanaz Rahmatiyan Naeimeh Bahri‐Laleh Ahad Hanifpour Mehdi Nekoomanesh‐Haghighi 《Polymer International》2019,68(1):94-101
The behaviors of three different catalyst systems, TiCl4/MgCl2, Cp2ZrCl2 and Cp2HfCl2, were investigated in ethylene/1,5‐hexadiene copolymerization. In the Fourier transform infrared spectra of the copolymers, cyclization and branching were detected for 1,5‐hexadiene insertion in the metallocene and Ziegler–Natta systems, respectively. DSC and viscometry analyses results revealed that copolymers with lower Tm and crystallinity and higher molecular weight were obtained with metallocene catalysts. The sequence length distribution of the copolymers was investigated by using the successive self‐nucleation and annealing thermal fractionation technique. The continuous melting endotherms obtained from successive self‐nucleation and annealing analysis were employed to get information about short‐chain branching, the branching dispersity index, comonomer content and lamella thickness in the synthesized copolymers. The results established that metallocene catalysts were much more effective than Ziegler–Natta catalysts in the incorporation of 1,5‐hexadiene in the polyethylene structure. Metallocene‐based copolymers had higher short‐chain branching and comonomer content, narrower branching dispersity index and thinner lamellae. Finally, the tendency of the employed catalysts in the 1,5‐hexadiene incorporation and cyclization reaction was explored via molecular simulation. The energy results demonstrated that, in comparison to Ziegler–Natta, metallocene catalysts have a much higher tendency to 1,5‐hexadiene incorporation and cyclization. © 2018 Society of Chemical Industry 相似文献