Evaluation of photo-induced cellular damage using photoautotrophic cultures of puk-bung hairy roots as a sensing tool

In photoautotrophic cultures of pak-bung hairy roots, strong light irradiation (22 W/m²) increased the content of reactive oxygen species (ROS) in the cells, resulting in chlorophyll (Chl) degradation and DNA injury. The Chl degradation rate, R_D, can be used as a parameter to measure the cellular damage caused by photo-induced stress. The presence of the antioxidants ascorbic acid, chlorogenic acid or catechin reduced the R_D, while lowering the content of ROS and moderating the DNA injury.     

Numerical Analysis of the Boundary Scattering Effect on Transport Properties in Bi-Sb Nanowires

In this study, we have numerically analyzed the transport properties of Bi-Sb nanowires, taking into account wire boundary scattering. Wire boundary scattering slightly decreased the Seebeck coefficient of Bi-Sb nanowires. This effect is due to the observation that boundary scattering and the mobility ratio of L-point electrons to T-point holes in the nanowires are smaller than those in bulk Bi-Sb because the wire boundary scattering suppresses the mobilities of L-point electrons and heavy holes. The largest Seebeck coefficient for all wire diameters was obtained when the Sb concentration was 5 at.%. The effective mass approached zero near 5 at.% Sb, and the small effective mass led to a large subband shift in each band. Thus, a small effective mass enhances the quantum effect at a fixed wire diameter, even if wire boundary scattering is taken into account.     

Preparation of Cu2ZnSnS4 thin films by sulfurizing electroplated precursors

Cu₂ZnSnS₄ (CZTS) thin films were prepared by sulfurizing precursors deposited by electroplating. The precursors (Cu/Sn/Zn stacked layers) were deposited by electroplating sequentially onto Mo-coated glass substrates. Aqueous solutions containing copper sulfate for Cu plating, tin sulfate for Sn plating and zinc sulfate for Zn plating were used as the electrolytes. The precursors were sulfurized by annealing with sulfur at temperatures of 300, 400, 500 and 600 °C in an N₂ gas atmosphere. The X-ray diffraction peaks attributable to CZTS were detected in thin films sulfurized at temperatures above 400 °C. A photovoltaic cell using a CZTS thin film produced by sulfurizing an electroplated Sn-rich precursor at 600 °C exhibited an open-circuit voltage of 262 mV, a short-circuit current of 9.85 mA/cm² and an efficiency of 0.98%.     

Persistence and partitioning of eight selected pharmaceuticals in the aquatic environment: Laboratory photolysis, biodegradation, and sorption experiments

We selected eight pharmaceuticals with relatively high potential ecological risk and high consumption—namely, acetaminophen, atenolol, carbamazepine, ibuprofen, ifenprodil, indomethacin, mefenamic acid, and propranolol—and conducted laboratory experiments to examine the persistence and partitioning of these compounds in the aquatic environment. In the results of batch sunlight photolysis experiments, three out of eight pharmaceuticals—propranolol, indomethacin, and ifenprodil—were relatively easily photodegraded (i.e., half-life < 24 h), whereas the other five pharmaceuticals were relatively stable against sunlight. The results of batch biodegradation experiments using river water suggested relatively slow biodegradation (i.e., half-life > 24 h) for all eight pharmaceuticals, but the rate constant was dependent on sampling site and time. Batch sorption experiments were also conducted to determine the sorption coefficients to river sediments and a model soil sample. The determined coefficients (K_d values) were much higher for three amines (atenolol, ifenprodil, and propranolol) than for neutral compounds or carboxylic acids; the K_d values of the amines were comparable to those of a four-ring polycyclic aromatic hydrocarbon (PAH) pyrene. The coefficients were also higher for sediment/soil with higher organic content, and the organic carbon-based sorption coefficient (log K_oc) showed a poor linear correlation with the octanol-water distribution coefficient (log D_ow) at neutral pH. These results suggest other sorption mechanisms—such as electrochemical affinity, in addition to hydrophobic interaction—play an important role in sorption to sediment/soil at neutral pH.     

A New Approach to Humanitarian Demining

Humanitarian demining is an application in which the use of tele-operated machines and mechanisms has been gaining acceptance recently. Actually, demining is just one among many other field applications that require a high degree of mobility, manipulation of loads, robustness and, above all, high efficiency in terms of energy consumption. This paper will present the development and analysis of Field Arm, a pantographic manipulator especially designed for field works, focusing on its kinematic, static and dynamic properties. The novel features of Field Arm will be presented and discussed with results of simulations and experiments.     

Two Step Timing Synchronization Scheme for OFDM Signal in General Purpose Processor Based Software Defined Radio Receiver

Software defined radio (SDR) is a technology that allows a single terminal to support various kinds of wireless systems by changing its software to reconfigure itself. A general purpose processor (GPP) based SDR receiver platform named Sora has been recently developed by Microsoft. In the GPP based SDR receiver, timing synchronization of an OFDM signal consumes a significant amount of computational resources in the GPP. In this paper, a timing synchronization scheme which uses delayed correlation and matched filtering for the GPP based SDR platform is evaluated. The two stage timing synchronization scheme reduces the computational complexity by limiting the timing range of matched filtering. The proposed scheme reduces the amount of data transmission between the memory and the GPP of the SDR platform. It is shown through an experiment that the proposed scheme reduces the number of cycles for timing synchronization by up to 30 %.     

Crystal growth and scintillation properties of Nd-doped Lu3Al5O12 single crystals with different Nd concentrations

Nd 0.1%, 0.5%, 1% and 3% doped Lu₃Al₅O₁₂ (Nd:LuAG) single crystals were grown in the nitrogen atmosphere by the micro-pulling down (μ-PD) method. The grown crystals had a single-phase confirmed by powder XRD analysis. In absorption spectra, some weak absorption lines due to Nd³⁺ 4f-4f transitions were observed and their intensity increased with the increase of Nd concentration. When excited by ²⁴¹Am α-ray, a broad emission peak due to defects in the host lattice at 320 nm and some sharp lines due to Nd³⁺ 4f-4f transitions at wavelength longer than 400 nm were observed. The decay time profiles of Nd:LuAG under γ-ray excitation were well approximated by two exponential function of 340-760 ns and 3-5 μs for each sample. By pulse height measurement using ¹³⁷Cs, Nd 0.5%:LuAG showed the highest light yield of 7600 ± 760 photons/MeV.     

Photo atomic layer deposition of transparent conductive ZnO films

Low-resistivity ZnO films were grown by photo atomic layer deposition (photo-ALD) technique using diethylzinc (DEZ) and H₂O as reactant gases. Self-limiting growth was achieved for the temperature range from 105°C to 235°C. It was found that UV light irradiation was very effective to increase the electron concentration of the films and the electron concentration of 5 × 10²⁰ cm⁻³ was achieved even in undoped ZnO. Thus, the resistivity of the films grown with UV irradiation was one order of magnitude less than that grown without UV irradiation. The minimum resistivity of 6.9 × 10⁻⁴Ω cm was obtained by photo- ALD method without any intentional doping.     

Method for simultaneous imaging of endogenous low molecular weight metabolites in mouse brain using TiO2 nanoparticles in nanoparticle-assisted laser desorption/ionization-imaging mass spectrometry

We report the detection of a group of endogenous low molecular weight metabolites (LMWM) in mouse brain (80-500 Da) using TiO(2) nanoparticles (NPs) in nanoparticle-assisted laser desorption/ionization-imaging mass spectrometry (Nano-PALDI-IMS) without any washing and separation step prior to MS analysis. The identification of metabolites using TiO(2) NPs was compared with a conventional organic matrix 2,5-dihydroxybenzoic acid (DHB) where signals of 179 molecules were specific to TiO(2) NPs, 4 were specific to DHB, and 21 were common to both TiO(2) NPs and DHB. The use of TiO(2) NPs enabled the detection of a higher number of LMWM as compared to DHB and gold NPs as a matrix. This approach is a simple, inexpensive, washing, and separation free for imaging and identification of LMWM in mouse brain. We believe that the biochemical information from distinct regions of the brain using a Nano-PALDI-IMS will be helpful in elucidating the imbalances linked with diseases in biomedical samples.