Metal nanoparticles are of interest for different biomedical and technical applications, for example by conjugation with DNA, enzymes or other biomolecules, for on-chip-labeling, for SERSanalytics, for heterogeneous catalysis and as antibacterial additives. Non-spherical metal nanoparticles are in the focus of developments due to their size- and shape-dependent optical properties. Recent results on the synthesis and behavior of noble metal nanoparticles are discussed from the point of view of the electric behaviour. The particle growth by a metal-catalyzed reductive metal deposition in liquid phase is regarded as an open-circuit mixed electrode system. Potential formation and the related electric charging of metal nanoparticles lead to self-polarization effects. These effects enforce spontaneous symmetry breaking effects during the formation of metal nanoparticles and explain the growth of non-spherical particles with high aspect ratios.

The paper presents some advances of a vacuum nano-transistor, known as Nothing On Insulator NOI device. The breakdown limitations are considered for ultra-thin buried oxide and different semiconductor islands shape. The relationship between oxide / semiconductor thickness and the breakdown voltage of the structure allow the gate limit voltage increasing from -6.5V to -12V using 15nm instead 10nm buried oxide. Reshaping the NOI transistor, a special semiconductor wall with one cube of roughnesses is analysed. The 1-cube variant has intermediate performances, as the maximum current capabilities.

We derive the Schrödinger eigen-energy dispersion relation for electrons on a two dimensional sheet with a one dimensional periodic lattice of quantum antidot potential barriers, in the presence of a strong perpendicular magnetic field. This system is Landau quantized by the high magnetic field and we determine the associated Green’s function for propagation along the axis of the antidot lattice, which we use to formulate the dispersion relation for the energy spectrum analytically in a closed form in terms of the Jacobi Theta Function (3rd kind). An approximate solution for the Landau quantized eigen-energies is obtained in terms of Laguerre polynomials, and the development of Landau minibands is explicitly exhibited.

Present study inspects the profiles of self-polarization effect (SPE) of impurity doped GaAs quantum dots (QDs) in presence of noise. Noise term maintains a Gaussian white character and it has been introduced to the system via two different pathways; additive and multiplicative. In view of a comprehensive analysis, modulation of SPE has been scrutinized along with the variations of several relevant quantities such as electric field, magnetic field, confinement potential, dopant location, dopant potential, noise strength and aluminium concentration (only for AlxGa1-xAs QD). Application of noise affects SPE noticeably. However, the extent to which SPE is altered depends on the noise strength domain and the pathway through which noise is applied. The outcomes of the study delineate viable routes to tune the SPE of doped QD system, particularly in presence of noise.

Shells of Jatorpha curcas is commonly used as fuel and as soil fertilizer. In our study, we investigate the use of shells to synthesize nanoscale particles by mechanical grinding via top down approach. The shade-dried shells are subjected to high energy milling to produce nanoparticles and the collected powder is characterized for their particle size, crystallinity, functional group and elemental composition. Antimicrobial activity of the prepared nanoparticles reveals the significant inhibitory effect against Gram positive bacteria (S. aureus and S. epidermis) and gram negative bacteria (E. coli and K. pneumoniae). Growth of gram positive organism is found to be reduced by 50-60 % when the particle size is increased from 1 to 20 mg/ml whereas gram negative bacteria has 30-45 % of growth reduction. When compared to control, shell nanoparticles exhibit an excellent antioxidant activity about at 78 % at 20 mg/ml against DPPH reagent. This preliminary evaluation for the bioactivity of shell nanoparticles from Jatropha lead the future biorefinery processing of Jatropha plant materials into cost effective biological product development.

It is ineluctable that language is a clear truism of the challenging of the human mind and it connects impressively to the brain. It has been investigated that neurotransmitters such as dopamine control human speech mechanism. In this work, it has been clarified the relation between language and brain through the chemical neurotransmitter by measuring the physicochemical properties of relative energy, Van der Waals forces and dipole moment via computational modeling. Then thermodynamic properties have been calculated by infrared radiation to recognize the active sites of dopamine structure and comparing it by some other neurotransmitters. In this paper, it has been exhibited that how dopamine can be effective for learning a new language and makes it easier and enjoyable.

This work is focussed on the role of the angle of incidence of an incoming electromagnetic wave in its transmission through a subwavelength nano-hole in a thin, smooth, planar semiconductor plasmonic layer. Fully detailed calculations and results are exhibited for p- and s-polarizations of the incident wave for a variety of incident angles in the middle and far zones of the transmitted radiation. Our dyadic Green’s function formulation includes both (1) the electromagnetic field transmitted directly through the 2D plasmonic layer superposed with (2) the radiation emanating from the nano-hole. Interference fringes due to this superposition are explicitly exhibited. Based on an integral equation formulation, this dyadic Green’s function approach does not involve any appeal to ideal metallic boundary conditions. It does incorporate the role of the 2D plasmon of the semiconductor layer, which is smeared due to its lateral wave number dependence. We find that the interference fringes, which are clustered near the nano-hole, flatten to a uniform level of transmission directly through the sheet alone at large distances from the nano-hole. Furthermore, as the incident angle increases, the axis of the relatively large central transmission maximum through the nano-hole follows it, accompanied by a spatial compression of interference fringe maxima forward of the large central transmission maximum, and a spatial thinning of the fringe maxima behind it. For p-polarization, the transmission results show a strong increase as the incident angle 0 increases, mainly in the dominant Ez component (notwithstanding a concomitant decrease of the Ex component as 0 increases). We also find that in the case of s-polarization of the incident electromagnetic wave, the transmission decreases as 0 increases. These results, for both p- and s-polarizations, are consistent with earlier results for perfect metal boundary conditions, although such ideal boundary conditions are not invoked here as we have treated the problem of a nano-hole in a semiconductor layer and have determined its electromagnetic transmission including the role of its two dimensional plasma.

Magnetic nanoparticles of cobalt ferrite (CoFe2O4) have been synthesized by chemical co-precipitation method with capable of controlling the average particle size of CoFe2O4 magnetic nanoparticles. Further, the surface of CoFe2O4 nanoparticles was coated with sodium oleate as the primary layer and polyethylene glycol 6000 (PEG-6000) as the second layer. X-ray diffraction (XRD) indicated the sole existence of partially inverse cubic spinel phase of CoFe2O4 and the average particle size calculated from XRD of about 29 nm. SEM analysis showed that the surface modification with PEG could increase crystallinity of nanoparticles, decrease the agglomeration and control the shape to more spherical. Fourier transform infrared spectroscopy (FT-IR) analysis indicated existence of two distinct surfactants on the particle surface. In addition, the results of FT-IR indicated that the coated CoFe2O4 particles improved with the thermal stability due to the interaction between the CoFe2O4 particles and protective layers. Magnetic characterization of CoFe2O4 was studied by Electron spin resonance (ESR). The results showed that the existence PEG in the CoFe2O4 decrease the spin resonance of conduction electrons.

KCC-1/bpt/Pd catalyst was readily prepared for first time from inexpensive starting materials in aqueous media which catalyzed the synthesis 1,4-dihydropyridines and 2-vinyl furans. High catalytic activity and ease of recovery from the reaction mixture using filtration, and several reuse times without significant losses in performance are additional eco-friendly attributes of this catalytic system.

Heme-based Metalloproteins play essential part as nano-biosensor for diatomic gases such as NO, O2, CO and so on. The electron and optic properties, and adsorption energy of Heme complex as the nano-biosensor for O2 and CO gases were studied using ab initio studies and density function theory (DFT) approach. The results show that Heme is highly capable of being used as a nano-biosensor for O2 and CO gases. Carbon monoxide has a lower adsorption energy but higher electron transfers with Heme. Energy gap raised to 0.09 eV in the presence of O2 and to 0.39 Ev in the presence of CO, which indicates the higher sensitivity of Heme to CO.

A customized optical system composed of collimating and focusing lenses is proposed to achieve the beam focusing of high-brightness diode laser bars with high fill factor for optoacoustic applications. Through an optimized design, the beam of a 940-nm diode laser bar is first collimated and symmetrized between the fast and slow axes, and then is reduced in size into a square beam (~ 3.7 mm x 3.7 mm at 1/e2 of the peak) with intensity of ~ 3.2 kW/cm2. In an optoacoustic environment, the optical spot achieved can illuminate a small region of tissue at high intensity to achieve in-depth imaging with high resolution.

The purpose of this study was to prepare and to characterize a new formulation of injectable capsaicin loaded poly (D,L-lactic-co-glycolic acid) (PLGA) microspheres (CAP-MS). The emulsion solvent evaporation process based on O/W emulsion was applied to prepared the CAP-MS with optimization of formulation using uniform design with three factors and six levels. The optimized formulation was then evaluated in terms of size, encapsulation efficiencies, drug loading, in vitro release profile, distribution and pharmacokinetics. According to the mathematic models, the optimal prescription and preparation technology can be conducted at the concentration of PLGA of 2%, the rotation speed of 1000 rpm and the mass ratio (CAP/PLGA) 1:2. The optimized CAP-MS resulted in spherical shapes and possessed a smooth surface. Average diameter, encapsulation efficiency and drug loading were turned out to be 4.73µm, 82.82% and 27.60%, respectively. In vitro release study represented a low initial burst release of approximately 21.26% within the first 24 h followed by a prolonged release up to 12 days and the release kinetics fitted well to the Higuchi model. In vivo results demonstrated that the drug suspension released rapidly after subcutaneous injection, the accumulate drug release was more than 97% after 12 hours, while the drug loaded microspheres release pro?le showed a large initial burst effect (59%), and then released slowly, nearly 100% of capsaicin released at the end of 20 days. These results indicate the PLGA microspheres is a promising system that could be exploited as a delivery system for capsaicin with high drug loading capacity and sustained drug release.

This work reports on successful one pot surfactant free in-situ synthesis of cobalt doped ZnO-chemically converted graphene (CCG) nanocomposite (CZG) by adopting a low temperature solution process utilizing zinc acetate dihydrate and graphene oxide with varying content of cobalt acetate tetrahydrate (upto 10% Co with respect to Zn) in the precursor medium. The materials properties were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), FTIR and Raman spectral analyses. The presence of ZnO nanoparticles (NPs) in the nanocomposites was confirmed by XRD and TEM studies. The TEM study revealed the uniform distribution of hexagonal ZnO in the CCG matrix. The existence of chemical interaction / complexation between CCG with ZnO/Zn2+ of the samples was confirmed by FTIR and Raman spectral analyses. The antibacterial activity was measured on Escherichia coli and Staphylococcus aureus as water borne bacteria to examine the efficiency of the nanocomposite towards killing the bacterial cells. Among the nanocomposites, 5% Co doped sample showed best antibacterial activity against the microorganisms. This synthesis strategy could open an avenue of Co doped other metal oxide-CCG nanocomposites for biomedical applications.

Highly-porous ceramics samples based on nanostructured biogenic hydroxyapatite and superfine fumed silica have been prepared using a foam replication method at a sintering temperature of 850°?. They were shown to possess a total porosity 86-89 % and a permeable open-porous (~ 90 % of the total porosity) structure with pore sizes in the range 500-1000 µm. The compression strength is equal to 0.3-0.4 ?P?. According to the XRD analysis it was established that during sintering hydroxyapatite phase remains, which was also confirmed by IR spectroscopy data. The carried out studies in vitro (the dissolution rate in saline) of the obtained highly-porous bioceramics showed that the samples are resorbable and their dissolution rate increases with growing porosity and decreasing HA content. Evaluation of adsorption activity (by the example of antibiotic Ceftriaxon) demonstrated prospectivity of ceramics as carriers of drugs for acceleration of patients’ post surgery rehabilitation in orthopedic, traumatic and dentistry surgery.

Here, the Baicalin-loaded PLGA microspheres (BC-MS) were prepared, and their properties in vitro and in vivo were evaluated. The microspheres were prepared using the solvent evaporation method based on O/W emulsion. The HPLC method was established in the determination of the content of baicalin in the microspheres. The surface and particle size were observed by the inverted microscopy, and the characteristics of in vitro release of BC-MS were investigated by dynamic dialysis method. After that, the microspheres were in vivo evaluated in rats. It was observed that the microspheres had an average particle size of 1.89µm, the drug loading was 12.79%, and the encapsulation rate was 85.40%. Moreover, the microspheres were spherical in shape and smooth surface with a uniform distribution. The release profiles of BC-MS agreed with Ritger-Peppas equation. The plasma concentration-time curves of BC-MS were fitted with two-compartment model. The results of pharmacodynamics in rats showed that: the elimination half-life of baicalin solution (BC-S) and Baicalin-loaded PLGA microspheres (BC-MS) were respectively 1.27 h and 258.98 h, mean residence time (MRT) were 0.88 h and 373.01 h, respectively. As the above result shows, BC-MS has the slow-release effect. Thus, the Baicalin-loaded PLGA microspheres have been successfully prepared.