Bone morphogenic protein-2 (BMP-2) loaded hybrid coating on porous hydroxyapatite scaffolds for bone tissue engineering

In this study, a silica xerogel-chitosan hybrid is utilized as a coating material to incorporate bone morphogenic protein-2 (BMP-2) on a porous hydroxyapatite (HA) scaffold for bone tissue engineering. BMP-2 is known as a therapeutic agent for improving bone regeneration and repair. Silica xerogel-chitosan hybrids have been used for the delivery of a growth factor as well as osteoconductive coatings. The biological properties of the hybrid coating incorporated with BMP-2 were evaluated in terms of the BMP-2 release behavior, osteoblastic cellular responses and in vivo performance. BMP-2 was continuously released from the hybrid coating layer on the porous HA scaffold for up to 6 weeks. The hybrid coating containing BMP-2 showed significantly enhanced osteoblastic cell responses in comparison with the hybrid coating and HA substrate. Consequently, new bone formation was significantly increased within the hybrid coating containing BMP-2. These results reveal that the hybrid coating containing BMP-2 has the potential to be used as a bone implant, whose osteogenic properties are promoted by the release of BMP-2 in a controlled manner for a prolonged period of time.     

Preparation and Evaluation of 2-(Allylthio)Pyrazine-Loaded Lipid Emulsion with Enhanced Stability and Liver Targeting

To develop 2-(allylthio)pyrazine (2-AP)-loaded lipid emulsion for parenteral administration, various lipid emulsions were prepared with soybean oil, lecithin, and other carriers using homogenization method, and their physical stabilities were investigated by measuring their droplet sizes. The pharmacokinetics and tissue distribution of 2-AP in lipid emulsion after intravenous administration to rats were evaluated compared with 2-AP in solution. 2-AP was lipophilic, sparingly water-soluble, and unstable in aqueous medium. The 2-AP-loaded lipid emulsion composed of 1% of 2-AP, 4% of soybean oil, 4% of lecithin, and 91% of water was physically and chemically stable for at least 8 weeks. It gave significantly faster clearance of 2-AP and higher affinity to the organs, especially the liver, compared with the 2-AP in solution, suggesting that it could selectively deliver 2-AP to the liver. Thus, the lipid emulsion with soybean oil and lecithin could be used as a potential dosage form with the liver-targeting property and enhanced stability of sparingly water-soluble 2-AP.     

Hydrogen production from low temperature WGS reaction on co-precipitated Cu–CeO2 catalysts: An optimization of Cu loading

Low temperature water–gas shift (WGS) reaction has been carried out at the gas hourly space velocity of 72,152 h⁻¹ over Cu–CeO₂ catalyst prepared by a co-precipitation method. Cu loading was optimized to obtain highly active co-precipitated Cu–CeO₂ catalysts for low temperature WGS. 80 wt% Cu–CeO₂ exhibited the highest CO conversion as well as the most stable activity (X_CO > 46% at 240 °C for 100 h). The excellent catalytic performance is mainly due to a strong metal to support interaction, resulting in the prevention of Cu sintering.     

A new fluoride mediated synthesis of mesoporous silica and their usefulness in controlled delivery of duloxetine hydrochloride a serotonin re-uptake inhibitor

A new type of mesoporous silica nanoparticle (MSN) was synthesized in fluoride media via sol–gel technique using TritonX 100 and Tween-20. The surface area and pore volume of the MSN particles were modified by varying the concentration of Tween-20. The prepared MSN nanoparticles with large surface area and pore volume (T-2, T-3) were selected to accommodate the model drug duloxetine hydrochloride (DX) for evaluation of their drug-loading and release abilities. Calcined and DX loaded nanoparticles were characterized by Brunauer–Emmett–Teller technique (BET), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric (TG) analysis and UV-diffuse reflectance (UV-DRS). In vitro release studies proved that the particle displays an initial burst release followed by sustained release for up to 140 h. From the studies it is evident that the synthesized particle may be useful as a carrier for sustained release of active pharmaceutical ingredients (APIs).     

Resistive switching characteristics and conducting nanobits of polycrystalline NiO thin films

Thin films of NiO were deposited on Pt/Ta/glass sub-strates using a radio frequency (RF) sputtering method. The NiO thin films showed polycrystalline nature, indicating preferentially (111)-oriented structure. The resistive random access memory (RRAM) capacitor of a Pt/NiO/Pt structure exhibited unipolar switching characteristics and bistable resistivities for 200 repeated switching cycles. Furthermore, RRAM nanobits array was formed on the NiO thin films by applying a bias. The RRAM nanobits had a diameter of approximately 8 nm and were observed via a conducting atomic force microscope (CAFM). The density of the RRAM nanobits array was estimated to be approximately 0.64 Tbit/cm².     

An efficient microwave-assisted Suzuki reaction using Pd/MCM-41 and Pd/SBA-15 as catalysts in solvent-free condition

Palladium catalysts, Pd/MCM-41 and Pd/SBA-15 were prepared by impregnation of an aqueous solution of [Pd(NH₃)₄]Cl₂ on MCM-41 and SBA-15. Palladium contents of Pd/MCM-41 and Pd/SBA-15 are 8.4% and 8.7%, respectively. It has been shown that these catalysts are very suitable to microwave-assisted Suzuki reactions under solvent-free condition. It is also found that the base additives for this reaction are K₂CO₃, Cs₂CO₃ or CsF. Thus, phenylboronic acid and phenyl iodide with Pd/MCM-41 produce biphenyl by microwave irradiation for 10 min in 97.4% yield. Phenyl bromide, instead of phenyl iodide, also proceeds the reaction with phenylboronic acid using Pd/MCM-41 or Pd/SBA-15 yielding biphenyl by microwave irradiation for 10 min in excellent yield. Whereas the reaction of phenyl chloride with phenylboronic acid gives poor yield in same condition. Various aryl iodides and aryl bromides are tested. In this paper our recent results of microwave-assisted Suzuki reaction using Pd/MCM-41 and Pd/SBA-15 under solvent-free condition are described.     

Design and analysis of cooperative wireless data access algorithms in multi-radio wireless networks

In the future, most mobile nodes will have multiple radio interfaces, and this feature can be exploited to reduce the transmission cost in wireless data access applications. In this work, we propose cooperative poll-each-read (CoopPER) and cooperative callback (CoopCB) wireless data access algorithms with strong consistency in multi-radio wireless networks. In addition, we investigate CoopPER and CoopCB in heterogeneous wireless networks where CoopPER and CoopCB nodes are mixed. Extensive simulations are done to show the effects of access-to-update ratio, data access pattern, cache size, and cooperation range. Simulation results demonstrate that CoopPER and CoopCB can significantly reduce the expensive transmission cost over wireless links.     

Probing of human implicit intent based on eye movement and pupillary analysis for augmented cognition

The ultimate purpose of augmented cognition is to enhance human cognitive abilities, which are intrinsically limited. To enhance limited human cognitive abilities, we developed a human augmented cognition system that can offer appropriate information or services by actively responding to the user's intention. This article mainly describes a framework for probing human implicit intentions for the purpose of augmented cognition. The type of user intention, either task‐free human implicit intention or task‐oriented human implicit intention, can be predicted based on fixation count, fixation length, and pupil size variation induced by eye response. Further, these features are used to detect the transition point between task‐free human implicit intention and task‐oriented human implicit intention. Maximum a Posteriori in Naïve Bayes classification model is used for selecting relevant query keywords to search and retrieve specific information from a personalized knowledge database. The experimental results show that the proposed human intention recognition and probing models are suitable for achieving the goal of augmented cognition. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 114–126, 2013