A cationic peptide dendrier, dendritic poly(L-lysine), forms complexes with oligonucleotides and can deliver them to liver after intravenous injection. Here, we tried to deliver apolipoprotein B-specific siRNA for the treatment of hypercholesterolemia and NFκB decoy for the hepatitis treatment. Significant therapeutic effects in those disease model mice were observed after intravenous injection of the oligonucleotides complexes with dendritic poly(L-lysine).

The development of new optimized photoinitiators for the two-photon induced photopolymerization (TPIP) is essential in order to obtain high resolutions in this solid freeform fabrication process. Herein, we present the syntheses and characterizations of a series of efficient photoinitiators, comprising of a cross conjugated D-π-A-π-D system. The different donor- and acceptor functionalities of the investigated photoinitiators as well as the synthesis of targeted derivatives containing double and triple bonds in the conjugated backbone allowed the evaluation of structure-activity relationships. The basic photophysical properties as well as the activity and ideal processing window under TPIP conditions were investigated for each initiator and compared with typical commercially available one-photon initiator and with two highly potential initiators well known from literature. These tests figured out that the new chromophores are highly potential even at concentrations down to 0.05 wt%.

Hydroxyapatite (HA) nanospheres were synthesized via the sol-gel route in the presence of poly(vinyl alcohol) (PVA). The HA nanospheres were formed from the reaction between (NH4)2HPO4 and CaCl2 in ethanol/PVA sol-gel system, in which ammonia solution (NH3•H2O) was added to adjust the pH of solution. The as-synthesized products were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDAX). XRD patterns and FTIR spectra showed that the HA nanospheres exhibit the crystalline structure and vibration bands of HA. The Ca/P molar ratio of HA nanospheres (50˜70nm) approached the stoichiometric value of 1.67, on the basis of EDAX results. Simulated Body Fluid (SBF) immersion test for three weeks demonstrated that the apatite layer can be formed on the HA nanospheres sintered at 550°C.

Ultrathin (∼10 nm) InN ion selective field effect transistors (ISFETs) show a current variation ratio of 3.5 % per pH decade with a response time of less than 10 s. When the ISFET is employed as an electrolyte FET, the current variation of 18 % was measured as the gate bias changes from zero to 0.3 V given a drain-source voltage of 0.1 V. The high current (resistance) variation ratio is attributed to the ultrathin epilayer and an unusual phenomenon of intrinsic strong electron accumulation on InN surface, which enables a chemical/biological sensor with high sensitivity and resolution and permits detection of a slight concentration variation of the electrolyte. The pH response measurement of 10-nm-thick InN ISFETs investigated was performed in an aqueous solution titrated with diluted NaOH and HCl. The Helmholtz potential built at the electrolyte-InN interface is governed by direct adsorption of H+ ions at the surface metal oxides, modulating the channel current of the InN ISFETs. The channel current monotonically decreases as the pH value of an aqueous solution increases from 2 to 10. The sensitivity and resolution were found to be 58.3 mV per decade and 0.02 pH change, respectively. Besides, the detection of DNA hybridization was further performed after the InN surface was modified with MPTMS and probe DNA. A complementary target DNA solution of 100 nM led to a current decrease of approximate 6 uA, corresponding to the current variation of 0.74 %. The hybridization between negatively charged complementary DNA and the immobilized probe DNA caused the depletion of carriers at the InN surface, suppressing the channel current. The functionalized InN ISFETs are suitable for genetic analysis in clinical diagnostics without any labeling reagent. Such an InN-based sensor is appealing in the regime of chemical and biological sensing applications.

Zn0.90Co0.10O particles, synthesized by mechanical milling and thermal treatment, were pressed at 25 tons to form a 2” target for a radio frequency (r. f.) magnetron sputtering system. Using this target, thin films were deposited on (0001) oriented sapphire (α-Al2O3) substrates under 30W, 60W and 120W r. f. powers. Structural analyses of these films were done with X-Ray Diffractometer (XRD), Energy Dispersive X-Ray Spectrometry (EDS), X-Ray Photo Spectroscopy (XPS) and Atomic Force Microscopy (AFM). The ZnO films were deposited with (0002) preferred direction, which was coherent to (0001) ordered α-Al2O3. Impurity phases, such as Co clusters, CoO and Co3O4, were not detected with the surface analyses of Zn0.90Co0.10O thin films. Substituted Co atoms in the host ZnO matrix were identified by the binding energy peak of Co2p3/2, 781.3±0.4eV, and the energy difference of ∼15.61±0.03eV between Co2p1/2 and Co2p3/2. These results also proved that there were no Co clusters or Co3O4 phases in the lattice. Homogeneity of Co atoms in the lattice was shown by EDS spectra. It was understood that the higher r. f. power caused the more homogeneous distribution of Co and Zn atoms in thin films. Distributions of Co and Zn on the film surface, deposited under 120W, were found as 8.1±0.1% (normalized atomic ratio) and 91.7±0.7% (normalized atomic ratio), respectively, and the surface roughness of thin film was demonstrated by AFM figures as 14.2±0.1nm.

Atomic Layer deposition of thin Ruthenium films has been studied using a newly synthesized precursor (Cyclopentadienyl ethylruthenium dicarbonyl) and O2 as reactant gases. Under our experimental conditions, the film comprises both Ru and RuO2. The initial growth is dominated by Ru metal. As the number of cycles is increased, RuO2 appears. From infrared broadband absorption measurements, the transition from isolated, nucleated film to a continuous, conducting film (characterized by Drude absorption) can be determined. Optical simulations based on an effective-medium approach are implemented to simulate the in-situ broadband infrared absorption. A Lorentz oscillator model is developed, together with a Drude term for the metallic component, to describe optical properties of Ru/RuO2 growth.

We have proposed and fabricated a hybrid nanodots floating gate (FG), in which Si quantum dots (QDs) as charge injection/emission nodes and NiSi nanodots as charge storage nodes are stacked with an ultrathin SiO2 interlayer, to satisfy both large memory window and multivalued capability. In this study, Si-QDs with an areal density of ˜3×1011cm-2 were formed on ultrathin SiO2 layer by controlling SiH4 chemical vapor deposition (CVD) and NiSi nanodots were prepared by full-silicidation of Si-QDs promoted with remote H2-plasma exposure after Ni evaporation. From capacitance-voltage(C-V) characteristics of MOS capacitors with a NiSi nanodots/Si-QDs hybrid FG, stable storage of many charges in the deep potential well of each NiSi nanodot was confirmed. Also, by applying pulsed gate biases, stepwise charge injection to and emission from NiSi nanodots through discrete energy states in Si-QDs were demonstrated. In addition, by 1310nm (˜0.95eV) light irradiation, a distinct optical response in C-V characteristics was detected, which can be interpreted in terms of the shift of charge centroid in the hybrid FG stack due to transfer of photoexcited electrons from NiSi-nanodots to the Si-QDs.

Chemical conditions and mass transport properties of engineered barrier systems in TRU waste facilities would change with time due to the interaction of cement/bentonite materials. (‘TRU waste’ is one of categories of the radioactive wastes and contains a significant amount of alpha-emitting transuranic nuclides. In some countries, these wastes are classified into the Intermediate Level Waste (ILW).) Previous numerical model analyses to assess the long-term performance of engineered barrier systems in TRU waste repositories predicted to form Calcium Silicate Hydrate (C-S-H) species at the interface between the cementitious and bentonite materials. If C-S-H precipitates in the bentonite side of the boundary, mass transport in the bentonite buffer decreases and mineralogical alterations are expected to be restricted for a long period. The evidence of C-S-H precipitation in the bentonite side, however, still has not been identified in the former experimental studies. To improve the reliability of numerical analyses, immersion experiments were performed using contact samples of cementitious and bentonite materials, and X-ray absorption fine structure (XAFS) analysis was carried out to detect C-S-H precipitation at the contacting interface. Precipitation of C-S-H was confirmed from the obtained XAFS spectra. This result is one of the evidences to show the validity of the current numerical model analyses, which suggests that the bentonite buffer performance as an engineered barrier would be kept over a long period.

Electroactive conducting polymers are currently studied for use in smart textiles that incorporate sensing, actuation, control, and data transmission. The development of intelligent garments that integrate these various functionalities over wide areas (i.e. the human body) requires the production of long, highly conductive, and mechanically robust fibers. This study focuses on the electrical, mechanical and electrochemical characterization of high aspect ratio polypyrrole fibers produced using a novel, custom-built fiber slicing instrument. In order to ensure high conductivity and mechanical robustness, the fibers are sliced from tetra-ethylammonium hexafluorophosphate-doped polypyrrole thin films electrodeposited onto a glassy carbon crucible. The computer-controlled, four-axis slicing instrument precisely cuts the film into thin, long fibers by running a sharp blade over the crucible in a continuous helical pattern. This versatile fabrication process has been used to produce free-standing fibers with square cross-sections of 2 μm × 3 μm, 20 μm × 20 μm, and 100 μm × 20 μm with lengths of 15 mm, 460 mm, and 1,200 mm, respectively. An electrochemical dynamic mechanical analyzer built in-house for nano- and microfiber testing was used to perform stress-strain and conductivity measurements in air. The fibers were found to, on average, have an elastic modulus of 1.7 GPa, yield strength of 37 MPa, ultimate tensile strength of 80 MPa, elongation at break of 49%, and an electrical conductivity of 12,700 S/m. SEM micrographs show that the fibers are free of defects and have cleanly cut edges. Preliminary measurements of the fibers’ strain-resistance relationship have resulted in gage factors suitable for strain sensing applications. Initial tests of the actuation performance of fibers in neat 1-butyl-3-methylimidazolium hexaflourophosphate have shown promising results. These monofilament fibers may be spun into yarns or braided into 2- and 3-dimensional structures for use as actuators, sensors, antennae, and electrical interconnects in smart fabrics.

A summary of experimental findings on the luminescence from conical bubble collapse, CBL is presented. Spatial, temporal, and spectral features of luminescence were investigated. In the experimental runs, two inert gases (Ar, Xe) and 1,2-Propanediol, PD, as work liquid were used. Single and multiple light emission events were recorded. Results show that there is a spectral evolution inside each pulse and through the whole experimental sequence. The average spectra consist of a broad continuum background, on which line emissions of OH°, CN, Na+, K+, and Swan lines are superimposed. An increase in continuum intensity from 300 to 860 nm was observed. The molecular and atomic lines as well as the continuum emission arise from different chemical pathways that take place during the bubble compression. Pathways come from the degradation of the liquid due to the repetition of the compression process, resulting in changes of the thermo-chemical conditions inside the cavity, such that each collapse was different. This becomes evident, by using low gas pressures, in which the luminescence was spatially and temporally non uniform. On the other hand if Xe instead of Ar is used the intensity of the luminescence increased one order of magnitude. These findings indicate that several components are presents in the bubble, besides the residual air and inert gas, vapor and liquid droplets, and within the latest water vapor, inert gas and alkali solutions are dissolved.

TiO2 is a promising material for use in environmental purification due to its strong oxidizing power, photoinduced hydrophilicity, non-toxicity and long-term photostability. Nanocomposites formed by silver dispersed in titania matrix have their application quality improved since silver particles can act in the electronic structure of the titania. In this work, titanium isopropoxide and silver nitrate solution was used as starting of Ag/TiO2 nanocomposites. After irradiation and gelification at room temperature, this material was dried and calcined at various temperatures up to 1100 °C. The nanocomposites were characterized to investigate the structural evolution of the nanoparticles and the dependence of crystallite size with the calcination temperature.

Thermal conductivities of Cs-M-O (M = Mo or U) ternary compounds, observed in the pellet-cladding gap region and in the pellet periphery in irradiated oxide fuels with high oxygen potentials, were investigated. Bulk samples of Cs2MoO4 and Cs2UO4 were prepared by hot pressing or spark plasma sintering, and their thermal diffusivities were measured by the laser flash method from room temperature to 823 K for Cs2MoO4 and to 900 K for Cs2UO4. The thermal conductivities were evaluated from the thermal diffusivity and bulk density, and the specific heat capacity values available in the literature. The thermal conductivities of Cs2MoO4 and Cs2UO4 were quite low compared with UO2 (e.g. 0.5 Wm−1K−1 at 800 K for Cs2MoO4).

We show that time-resolved electron diffraction is capable of revealing the ultrafast lattice heating in thin metal films following excitation by a femtosecond laser pulse. The build-up of the lattice temperature leads to a reduction of the diffraction intensity of the various diffraction orders due to the Debye-Waller-effect. We also observed a reduction of the transmitted (000)-signal which exhibits the same temporal evolution as the diffraction signals.

Elasto-plastic response of bulk metallic glasses (BMGs) follows closely the response of granular materials through pressure dependent (or normal stress) yield locus and shear stress induced material dilatation. On a micro-structural level, material dilatation is responsible for stress softening and formation of localized shear band, however its influence on the macro-scale flow and deformation is largely unknown. In this work, we systematically analyze the effect of material dilatation on the gross indentation response of Zr-based BMG via finite element simulation. The strengthening/softening effect on the load-depth response and corresponding stress-strain profiles are presented in light of differences in elastic-plastic regimes under common indenters. Through comparison with existing experimental results, we draw conclusions regarding selection of suitable dilatation parameters for accurately predicting the gross response of BMGs

Even if the Binary Collision Approximation does not take into account relaxation processes at the end of the displacement cascade, the amount of displaced atoms calculated within this framework can be used to compare damages induced by different facilities like pressurized water reactors (PWR), fast breeder reactors (FBR), high temperature reactors (HTR) and ion beam facilities on a defined material. In this paper, a formalism is presented to evaluate the displacement cross-sections pointing out the effect of the anisotropy of nuclear reactions. From this formalism, the impact of fast neutrons (with a kinetic energy En superior to 1 MeV) is accurately described. This point allows calculating accurately the displacement per atom rates as well as primary and weighted recoil spectra. Such spectra provide useful information to select masses and energies of ions to perform realistic experiments in ion beam facilities.

Solar electric (Photovoltaic) crystalline silicon (c-Si) product design and diversity has changed very little over three decades of development since the inception of the photovoltaic industry. The dominant module product comprising over 90% of cumulative installations, which exceed 15 GW worldwide, employs a ubiquitous planar laminate configuration. This paper reviews the history of development of this commodity product, and examines the scientific underpinnings of the materials base of the c-Si module platform, which has provided confidence for manufacturers to lengthen product performance warranties to the current 25 year standard. Recent trends in c-Si module design, materials and manufacturing methods will also be discussed.

Rapid healing of acute and chronic skin defects is an important objective. In the present work, we report on the design and feasibility of a co-culture system for fibroblasts and keratinocytes by using electrospun polycaprolactone (PCL) scaffolds. Specifically, we quantified the effect of scaffold fiber diameter on keratinocyte attachment, proliferation and differentiation along with collagen secretion by fibroblasts post vacuum seeding with fibroblasts at various depths. The results show that fibroblasts secrete more collagen and keratinocytes differentiate more on 400 nm scaffolds than on 1000 nm scaffolds. Also, fibroblasts co-cultured with keratinocytes provide increased collagen secretion and keratinocyte differentiation. These results suggest that the fiber architecture can be a useful parameter in skin tissue engineering.

Series of Raman spectra were measured for microcrystalline silicon thin film with variable crystallinity. Five sets of Raman spectra (corresponding to excitations at 325 nm, 442 nm, 514.5 nm, 632.8 nm and 785 nm wavelengths) were subjected to factor analysis which showed that each set of spectra consisted of just two independent spectral components. Decomposition of the measured Raman spectra into the amorphous and the microcrystalline components is illustrated for 514.5 nm and 632.8 nm excitations. Effect of the light scattering on absolute intensity of Raman spectra was identified even for excitation wavelength highly absorbed in the mixed phase silicon layers.

Chemical bath deposition (CBD) is a commonly used method of depositing cadmium sulfide (CdS) films for photovoltaic application. The method is based on decomposition of a sulfur source in an alkaline solution of a cadmium source on the surface of the Cu(In,Ga)Se2 (CIGS) substrate. On the lab scale the CdS film is deposited by submerging a 1” square CIGS substrate in a heated beaker containing the chemical bath. This batch processing method is the one used for record-performing devices. There is an ongoing effort at the National Renewable Energy Laboratory to scale-up the CBD process to deposit CdS films on 6” square substrate. Efforts are focused at designing both batch and flow reactors for depositing uniform, device quality CdS films on larger substrates. Batch reactor designs involve reproducing the deposition process in the beaker on a bigger scale with minimal chemical waste, while flow reactors are designed for continuous processing, such as encountered in roll-to-roll manufacturing lines.

Compressive strained Silicon from a Silicon on Insulator (SOI) substrate is obtained by replacing the buried oxide layer by a strained silicon nitride layer. The silicon overlayer and the buried dielectric are etched down to the substrate to form narrow wires (down to 300 nm wide). The Si overlayer is then expected to acquire compressive strain thanks to the relaxation of the SiN layer. The goal is to obtain a high uniaxial stress perpendicular to the wires. The structures and the strain are modeled using finite element simulations. The strain elements are used to calculate Raman spectra. Theoretical results are compared to experimental profiles deduced from resonant (UV) micro Raman experiments.