Preparation,optimization, and characterization of simvastatin nanoparticles by electrospraying: An artificial neural networks study

The purpose of this study was to determine major factors impacting the size of simvastatin (SIM)‐loaded poly(d , l ‐lactic‐co‐glycolide) (PLGA) nanoparticles (NPs) that was prepared using electrospraying. Three variables including concentration of polymer and salt as well as solvent flow rate were used as input variables. Size of NPs was considered as output variable. For the first time, our findings using a systematic and experimental approach, showed the importance of salt concentration as the dominant factor determining the size with a sharp and reverse effect. Optimum formulation (i.e., flow rate 0.08 mL h^?1, polymer concentration 0.7 w/v %, and salt concentration 0.8 mM) was then evaluated for aqueous solubility, encapsulation efficiency, particle size, in vitro drug release pattern and cytotoxicity. A very appreciable encapsulation efficiency (90.3%) as well as sustained release profile, considerable enhancement in aqueous solubility (～5.8 fold) and high IC₅₀ (>600 µM of SIM‐loaded PLGA NPs) indicated PLGA as a promising nanocarrier for SIM. The optimum formulation had particle size, zeta potential value, polydispersity index (PDI) and drug loading of 166 nm, +3 mV, 0.62 and 9%, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43602.     

Differential regulation of the mcb and emr operons of Escherichia coli: role of mcb in multidrug resistance

The mcb operon (which is responsible for microcin B17 production) and the emr operon (which encodes a multidrug resistance pump) share a common negative regulator, EmrR. Nevertheless, compounds that induce the emr operon repress the mcb operon. The pump dedicated to microcin B17 extrusion can also protect the calls against sparfloxacin and other toxic compounds.     

Gelation of Amylopectin without Long Range Order

Weak amylopectin gels have been formed directly following dissolution of waxy maize granules. Rheological characterisation of these gels has been carried out as a function of stress and frequency. The gels are visually clear and homogeneous, and environmental scanning electron microscopy shows no trace of the original granules remaining. It is postulated that the origin of the gel network lies in pairwise aggregation of outer chains of the amylopectin molecules, presumably via double helix formation. However, these pairs of chain segments do not aggregate to develop crystallinity.     

FPGA给汽车电子带来新机遇

根据主要从事半导体及电子市行业市场调研的机构Databeans调查．电气和电子元件占一般汽车总成本约20％。该公司估计一辆2004年生产的低价位汽车上有150到180个电子元件．而现在生产的高价位汽车上则最少包含400个电子元件。     

A self-aligned process for high-voltage, short-channel vertical DMOSFETs in 4H-SiC

In this paper, we describe a self-aligned process to produce short-channel vertical power DMOSFETs in 4H-SiC. By reducing the channel length to /spl les/0.5 /spl mu/m, the specific on-resistance of the MOSFET channel is proportionally reduced, significantly enhancing performance.     

Fabrication and Characterization of CZTS Thin Films Prepared by the Sulfurization of RF-Sputtered Stacked Metal Precursors

In this work, Cu₂ZnSnS₄ (CZTS) thin films were prepared by the sulfurization of metal precursors deposited sequentially via radio frequency magnetron sputtering on Mo-coated soda-lime glass. The stack order of the precursors was Mo/Zn/Sn/Cu. Sputtered precursors were annealed in sulfur atmosphere with nine different conditions to study the impact of sulfurization time and substrate temperature on the structural, morphological, and optical properties of the final CZTS films. X-ray fluorescence was used to determine the elemental composition ratio of the metal precursors. Final CZTS films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). XRD and EDS were combined to investigate the films’ structure and to identify the presence of secondary phases. XRD analysis indicated an improvement in film crystallinity with an increase of the substrate temperature and annealing times. Also indicated was the minimization and/or elimination of secondary phases when the films experienced longer annealing time. EDS revealed slight Sn loss in films sulfurized at 550°C; however, an increase of the sulfurization temperature to 600°C did not confirm these results. SEM study showed that films treated with higher temperatures exhibited dense morphology, indicating the completion of the sulfurization process. The estimated absorption coefficient was on the order of 10⁴ cm^?1 for all CZTS films, and the values obtained for the optical bandgap energy of the films were between 1.33 eV and 1.52 eV.     

Passive detection of image forgery using DCT and local binary pattern

With the development of easy-to-use and sophisticated image editing software, the alteration of the contents of digital images has become very easy to do and hard to detect. A digital image is a very rich source of information and can capture any event perfectly, but because of this reason, its authenticity is questionable. In this paper, a novel passive image forgery detection method is proposed based on local binary pattern (LBP) and discrete cosine transform (DCT) to detect copy–move and splicing forgeries. First, from the chrominance component of the input image, discriminative localized features are extracted by applying 2D DCT in LBP space. Then, support vector machine is used for detection. Experiments carried out on three image forgery benchmark datasets demonstrate the superiority of the method over recent methods in terms of detection accuracy.     

Enhancing the Stability of CuO Thin-Film Photoelectrodes by Ti Alloying

A major drawback for CuO as an efficient photocathode in photoelectrochemical (PEC) water splitting is its instability in aqueous solution. In this paper, we report that Ti alloying can enhance the stability of CuO in PEC water splitting but at the cost of reduced crystallinity and optical absorption, and therefore reduced photocurrent. We further report that a balance between the stability and photocurrent can be realized by a bilayer configuration—a thin Ti-alloyed CuO layer on a pure CuO thin film. Our results indicate that the thickness of the top Ti-alloyed CuO layer should be optimized to realize the best stability and photocurrent.     

Structural,Dielectric, and Magnetic Properties of Ba-Doped Multiferroic Bismuth Ferrite

The main focus of the research was to correlate the microstructure with dielectric and magnetic properties of Bi1-xBaxFeO3 samples. Bi1-xBaxFeO3 samples(x = 0.1, 0.2 and 0.3) were synthesized by the conventional solid-state reaction method using nano-powders of Bi2O3, Fe2O3, and BaCO3. Thereafter, field emission scanning electron microscope and X-ray diffraction(XRD) techniques were used to examine the structure and phase of the samples. Phase analysis by XRD indicated that the single-phase perovskite structure was formed with possible increment in lattice parameter with increasing Ba doping. Complex permeability(u'iand u'i) measured using impedance analyzer confirmed the increase in magnetic property with increasing Ba doping. Finally, dielectric constant(k) was analyzed as a function of temperature at different frequencies. Dielectric constant as high as 2900 was attained in this research for Bi0.8Ba0.2FeO3 sample due to reduction in leakage current at this composition.