排序方式: 共有176条查询结果,搜索用时 10 毫秒
141.
Hamed Nosrati Soodabeh Davaran Hamidreza Kheiri Manjili Hamed Rezaeejam Hossein Danafar 《应用有机金属化学》2019,33(10)
In this time researchers make a great efforts to develop new hybrid nanoparticles for medical and pharmaceutical applications. Fe3O4‐Au hybrid heterodimers have been prepared with superior properties for various claims. Unfortunately, Fe3O4‐Au heterodimers are not stable in the physiological medium. In this study, we employed the albumin macromolecules as a stabilizer of Fe3O4‐Au hybrid nanoparticles (noted as Fe3O4‐Au‐BSA hybrid nanoparticles). After characterization of synthesized nanoparticles by FTIR, UV–Vis, TEM, DLS, DSC, VSM and XRD techniques, the in vitro and in vivo biocompatibility of these nanoparticles were also evaluated. We encountered with an amazing result which confirmed nanoparticles could be stabilized by linking the BSA on the surface of Fe3O4‐Au heterodimers. Also, intravenous injection of Fe3O4‐Au‐BSA hybrid nanoparticles up to 400 mg/kg to Balb C mice show that these nanoparticles were non‐toxic. The biocompatibility and stereological study had been performed for more than 30 days after nanoparticles administration, using hystomorphometric analysis. Remarkably, to the best of our knowledge, it was the first time the biocompatibility and biodegradability of Fe3O4‐Au were studied and evaluated by stereological technique. Further promotion and biomedical usage of this type of hybrid nanoparticles are underway in our laboratory. 相似文献
142.
Dr. Hamidreza Arandiyan Dr. Sajjad S. Mofarah Dr. Yuan Wang Dr. Claudio Cazorla Dr. Deshetti Jampaiah Dr. Magnus Garbrecht Prof. Karen Wilson Prof. Adam F. Lee Prof. Chuan Zhao Prof. Thomas Maschmeyer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(58):14418-14426
Perovskite oxides are regarded as promising electrocatalysts for water splitting due to their cost-effectiveness, high efficiency and durability in the oxygen evolution reaction (OER). Despite these advantages, a fundamental understanding of how critical structural parameters of perovskite electrocatalysts influence their activity and stability is lacking. Here, we investigate the impact of structural defects on OER performance for representative LaNiO3 perovskite electrocatalysts. Hydrogen reduction of 700 °C calcined LaNiO3 induces a high density of surface oxygen vacancies, and confers significantly enhanced OER activity and stability compared to unreduced LaNiO3; the former exhibit a low onset overpotential of 380 mV at 10 mA cm−2 and a small Tafel slope of 70.8 mV dec−1. Oxygen vacancy formation is accompanied by mixed Ni2+/Ni3+ valence states, which quantum-chemical DFT calculations reveal modify the perovskite electronic structure. Further, it reveals that the formation of oxygen vacancies is thermodynamically more favourable on the surface than in the bulk; it increases the electronic conductivity of reduced LaNiO3 in accordance with the enhanced OER activity that is observed. 相似文献
143.
Chang J Peng XF Hijji K Cappello J Ghandehari H Solares SD Seog J 《Journal of the American Chemical Society》2011,133(6):1745-1747
One-dimensional nanostructures are ideal building blocks for functional nanoscale assembly. Peptide-based nanofibers have great potential in building smart hierarchical structures due to their tunable structures at the single residue level and their ability to reconfigure themselves in response to environmental stimuli. We observed that pre-adsorbed silk-elastin-based protein polymers self-assemble into nanofibers through conformational changes on a mica substrate. Furthermore, we demonstrate that the rate of self-assembly was significantly enhanced by applying a nanomechanical stimulus using atomic force microscopy. The orientation of the newly grown nanofibers was mostly perpendicular to the scanning direction, implying that the new fiber assembly was locally activated with directional control. Our method provides a novel way to prepare nanofiber patterned substrates using a bottom-up approach. 相似文献
144.
N-Arylation of a wide variety of amines with phenylboronic acid catalyzed by copper acetate under 20%aqueous solution of n-Bu4NOH was accomplished in good to excellent yields(up to 92%) and substrate conversions(up to 96%). 相似文献
145.
Adam A. Dinerman Joseph Cappello Mohamed El‐Sayed Stephen W. Hoag Hamidreza Ghandehari 《Macromolecular bioscience》2010,10(10):1235-1247
The influence of solute hydrophobicity and charge on partitioning and diffusion in physically crosslinked networks of a genetically engineered SELP polymer was investigated. A series of fluorescent dyes were used to assess the impact of solute charge and hydrophobicity on release behavior. The mechanism of solute release from the SELP hydrogel appeared to vary as a function of dye hydrophobicity. The extent of FITC attachment to amine‐terminated G4 dendrimers influenced SELP hydrogel partitioning more than dendrimer diffusion properties. Results suggest the possibility of controlling solute release from SELP hydrogels by modifying the hydrophobicity and surface charge of drugs and drug/polymer conjugates as well as the possibility of “designing‐in” solute‐specific interactions.
146.
Abasalt Bodaghi Seyed Mohsen Moosavi Hamidreza Rahimi 《Annali dell'Universita di Ferrara》2013,59(2):235-250
In the current work, we obtain the general solution of the following generalized cubic functional equation $$\begin{aligned}&f(x+my)+f(x-my)\\&\quad =2\left( 2\cos \left( \frac{m\pi }{2}\right) +m^2-1\right) f(x)-\frac{1}{2}\left( \cos \left( \frac{m\pi }{2}\right) +m^2-1\right) f(2x)\\&\qquad +m^2\{f(x+y)+f(x-y)\} \end{aligned}$$ for an integer $m \ge 1$ . We prove the Hyers–Ulam stability and the superstability for this cubic functional equation by the directed method and a fixed point approach. We also employ the mentioned functional equation to establish the stability of cubic Jordan $*$ -derivations on $C^*$ -algebras and $JC^*$ -algebras. 相似文献
147.
Mohamad Dosaranian-Moghadam Hamidreza Bakhshi Gholamreza Dadashzadeh 《Wireless Personal Communications》2012,65(2):293-318
The interference reduction capability of antenna arrays, base station assignment, and the power control algorithms have been considered separately as means to increase the capacity in wireless communication networks. In this paper, we propose smart step closed-loop power control (SSPC) algorithm and base station assignment method based on minimizing the transmitter power (BSA-MTP) technique for direct sequence-code division multiple access (DS-CDMA) receiver in a 2D urban environment. This receiver consists of conjugate gradient adaptive beamforming and matched filter in two stages using antenna arrays. In addition, we study an analytical approach for the evaluation of the impact of power control error (PCE) on the DS-CDMA cellular systems. The simulation results indicate that the SSPC algorithm and the BSA-MTP technique can significantly improve the network bit error rate in comparison with conventional methods. Our proposed methods can also significantly save total transmit power and extend battery life in mobile units. In addition, we show that the convergence speed of the SSPC algorithm is faster than that of conventional algorithms. Finally, we discuss two parameters of PCE and channel propagation conditions (path-loss parameter and variance of shadowing) and their effects on the capacity of the system via some computer simulations. 相似文献
148.
Faizal Karim Marco Ottavi Hamidreza Hashempour Vamsi Vankamamidi Konrad Walus André Ivanov Fabrizio Lombardi 《Journal of Electronic Testing》2009,25(1):55-66
This paper analyzes the effect of random phase shifts in the underlying clock signals on the operation of several basic Quantum-dot
Cellular Automata (QCA) building blocks. Such phase shifts can result from manufacturing variations or from uneven path lengths
in the clocking network. We perform numerical simulations of basic building blocks using two different simulation engines
available in the QCADesigner tool. We assume that the phase shifts are characterized by a Gaussian distribution with a mean
value of , where i is the clock number and a standard deviation, σ, which is varied in each simulation. Our results indicate that the sensitivity of building blocks to phase shifts depends
primarily on the layout while the reliability of all building blocks starts to drop once the standard deviation, σ exceeds 4°. A full adder was simulated to analyze the operation of a circuit featuring a combination of the building blocks
considered here. Results are consistent with expectations and demonstrate that the carry output of the full adder is better
able to withstand the phase shifts in the clocking network than the Sum output which features a larger combination of the simulated building blocks.
相似文献
Faizal KarimEmail: |
149.
Synthesis of water dispersible boron core silica shell (B@SiO<Subscript>2</Subscript>) nanoparticles
Nathan I. Walton Zhe Gao Yulia Eygeris Hamidreza Ghandehari Ilya Zharov 《Journal of nanoparticle research》2018,20(4):112
Water dispersible boron nanoparticles have great potential as materials for boron neutron capture therapy of cancer and magnetic resonance imaging, if they are prepared on a large scale with uniform size and shape and hydrophilic modifiable surface. We report the first method to prepare spherical, monodisperse, water dispersible boron core silica shell nanoparticles (B@SiO2 NPs) suitable for aforementioned biomedical applications. In this method, 40 nm elemental boron nanoparticles, easily prepared by mechanical milling and carrying 10-undecenoic acid surface ligands, are hydrosilylated using triethoxysilane, followed by base-catalyzed hydrolysis of tetraethoxysilane, which forms a 10-nm silica shell around the boron core. This simple two-step process converts irregularly shaped hydrophobic boron particles into the spherically shaped uniform nanoparticles. The B@SiO2 NPs are dispersible in water and the silica shell surface can be modified with primary amines that allow for the attachment of a fluorophore and, potentially, of targeting moieties. 相似文献
150.