Influence of pH on the permeability of p-toluidine and aminopyrine through shed snake skin as a model membrane

The influence of pH on the permeability of p-toluidine (pKa, 5.3) and aminopyrine (pKa, 5.0) through shed snake skin as a model membrane was studied. The pH was adjusted to several values, and the solubility of the drugs in each donor was measured. Flux rates and permeability coefficients were calculated from the steady-state penetration portions. The flux rates of p-toluidine decreased as the pH value in the donor solution increased. On the other hand, the flux rates of aminopyrine were constant at any pH value. The permeability coefficients of each drug increased as the pH value in the donor solution increased. The partition coefficients (octanol/buffer) of each drug were dependent on the molecular fraction of un-ionized species. From these results, it is suggested that ionized species of p-toluidine transports through shed snake skin, but the ionized species of aminopyrine does not.     

Crosstalk Countermeasures for High-Density Inductive-Coupling Channel Array

Inductive coupling among stacked chips in a package enables 1 Gb/s/channel data communications. Array arrangement of the channel increases data bandwidth, while signal may be degraded by crosstalk. In this paper, crosstalk is measured and analyzed, and crosstalk countermeasures are discussed. Received signal waveforms through the inductive coupling are measured by embedded voltage detectors on a test chip. Interference-to-signal ratio (ISR) has good agreement between the measurements and calculations. It is found that crosstalk is reduced negligibly at a certain distance. If the channels are arranged at intervals of this distance, ISR is minimized. A technique based on time interleaving is also proposed to further reduce crosstalk. A 3times17 channel array is implemented with the crosstalk countermeasures. The channel pitch is taken down to 50 mum. Inter-chip communication with data rate of 1 Gb/s/channel and bit error rate (BER) lower than 10^-9 is demonstrated     

Development and applications of a compact hybrid tabletop terawatt chirped-pulse amplification Ti:sapphire-Nd:glass laser for x-ray lasing and harmonic generation

A hybrid tabletop (2 m x 3 m) terawatt chirped-pulse amplification Ti:sapphire-Nd:glass laser (1054 nm, 475 fs, 500 mJ, 9 x 10(17) W cm(-2)) has been developed for laser-matter experiments. An overall gain factor of 10(10) was achieved for the laser. The results of laser applications in the studies of soft-x-ray Ni-like Mo 18.9-nm lasing and of harmonic generation from solid surfaces are presented.     

Behavior of Cu nanoparticles ink under reductive calcination for fabrication of Cu conductive film

Cu nanoparticle ink was prepared from Cu nanoparticles that were coated with a gelatin layer at an average diameter of 46 nm. The Cu nanoparticle ink was applied on the polyimide substrate. Conductive films were fabricated using the Cu nanoparticle ink with a two-step annealing process consisting of oxidative pre-heating at 200 °C under 10 ppm O₂-N₂ mixed gas flow and reductive calcination at 250 °C under 3 vol.% H₂-N₂ mixed gas flow showed a low resistivity of 5 μΩ cm. The hydrolysis of the remaining gelatin layer by H₂O vapor, which was formed during the reduction of the Cu oxide by 3 vol.% H₂-N₂ mixed gas, was suggested. The results suggest the possibility of the removal of the gelatin layer without oxidative pre-heating and simultaneous sintering of Cu nanoparticles in reductive calcination.     

A feasible core design of lead bismuth eutectic cooled CANDLE fast reactor

Among the innovative reactor concepts, CANDLE has several advantages over conventional reactor designs. However, when CANDLE is extended to long life, the clad integrity at high neutron fluence, the build-up of fission product gases, and the pressure drop for long cores pose technological challenges which have to be overcome. In this paper, we propose practically viable design procedures, such as recladding the entire fuel pins and replacement of different amounts of fuel at different radial positions, to ensure clad integrity and flat power distribution, respectively. We demonstrate the efficacy of such design procedures by calculations that are performed on a LBE CANDLE reactor. Our calculations show that for a reactor operation period of 3700 days the various reactor parameters are within the limits proposed by Japan Atomic Energy Agency (JAEA).     

A new fabrication technology for AlGaAs/GaAs HEMT LSIs using InGaAsnonalloyed ohmic contacts

The authors studied the nonalloyed ohmic characteristics of HEMTs (high electron mobility transistors). At high integration levels, nonalloyed ohmic contacts were found to have two advantages: an extremely short ohmic length with low parasitic source series resistance and direct connection between the source/drain and gate with the same metal. The propagation delay in a ring oscillator with a single-metal source/drain and gate formed simultaneously was 37 ps/gate (L _g=0.9 μm). The very short ohmic metal contacts and just three contact holes made it possible to reduce the memory cell area greatly. The cell is 21.5×21.5 μm², one of the smallest ever reported for a GaAs-based static RAM. Using smaller load HEMTs or resistor loads in the memory cell, combined with nonalloyed ohmic technology with quarter- or subquarter-micrometer-gate HEMTs it is possible to fabricate a very-high-speed LSI such as a 64-kb static RAM with a reasonable chip size     

Safety assessment of paper and board food packaging: Chemical analysis and genotoxicity of possible contaminants in packaging

In order to identify potential genotoxicant(s) in recycled paperboard, samples were fractionated using multiple liquid/liquid extraction, and gel permeation chromatography, and analysed by gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. The rec-assay was used as an indicator of genotoxicity. Genotoxicants in the recycled paperboard were identified as dehydroabietic acid (DHA) and abietic acid (AA). DHA and AA were detected in two out of five virgin products, and in all seven recycled products for food-contact use. Total amounts of DHA and AA were 240 and 990 µg/g in the virgin products and 200-990 µg/g in the recycled products. A good correlation was observed in the total amount of DHA and AA content determined in paper products and DNA-damaging activity. Moreover, genotoxic effects in paper products showed a good match with standard compounds, indicating that the genotoxic effects of these paper products was mostly attributable to DHA and AA.     

Identification of SYS1 as a Host Factor Required for Shiga Toxin-Mediated Cytotoxicity in Vero Cells

Shiga toxin (STx) or Vero toxin is a virulence factor produced by enterohemorrhagic Escherichia coli. The toxin binds to the glycosphingolipid globotriaosylceramide (Gb3) for its entry, and causes cell death by inhibiting ribosome function. Previously, we performed a loss-of-function screen in HeLa cells using a human CRISPR knockout (KO) library and identified various host genes required for STx-induced cell death. To determine whether this library targeted to the human genome is applicable to non-human primate cells and to identify previously unrecognized factors crucial for STx-induced cell death, we herein performed a similar screen in the African green monkey kidney-derived Vero C1008 subline. Many genes relevant to metabolic enzymes and membrane trafficking were enriched, although the number of enriched genes was less than that obtained in the screening for HeLa cells. Of note, several genes that had not been enriched in the previous screening were enriched: one of these genes was SYS1, which encodes a multi-spanning membrane protein in the Golgi apparatus. In SYS1 KO Vero cells, expression of Gb3 and sphingomyelin was decreased, while that of glucosylceramide and lactosylceramide was increased. In addition, loss of SYS1 inhibited the biosynthesis of protein glycans, deformed the Golgi apparatus, and perturbed the localization of trans-Golgi network protein (TGN) 46. These results indicate that the human CRISPR KO library is applicable to Vero cell lines, and SYS1 has a widespread effect on glycan biosynthesis via regulation of intra-Golgi and endosome–TGN retrograde transports.     

Device design with automatic simulation system for basic CCDcharacteristics

A simulation system has been developed to automatically analyze basic electrical characteristics of a charge-coupled device (CCD) image sensor from a process simulation result. This system shortened the simulation period to approximately 1/10 by getting rid of complicated repetitious procedures. A high-performance new cell technology has been developed successfully with improving impurity distribution in shorter development time by using this system. This technology has been realized as a CCD cell pixel with CCD charge quantity of 1.8 times, effective transfer efficiency of over 99%, no image lag for driving read-out pulse voltage in comparison with conventional technology. A 1/4-in 330 K square pixel progressive-scan CCD was fabricated with this technology. These results are described to demonstrate the effectiveness of the automatic simulation system     

Nonpolar AlGaN/GaN Metal–Insulator–Semiconductor Heterojunction Field-Effect Transistors With a Normally Off Operation

Nonpolar AlGaN/GaN metal–insulator–semiconductor-heterojunction field-effect transistors (MIS-HFETs) with a complete normally off operation have been demonstrated for the first time. To realize the normally off operation of the MIS-HFETs, a 2-nm-thick SiN (as an insulator) and GaN-based nonpolar epitaxial layers that are free from polarization charges are employed. We have found that a thicker nonpolar AlN buffer layer achieves a GaN layer with a narrower full width at half maximum of the X-ray rocking curve and higher electron mobility. The fabricated MIS gate structure on the AlN buffer layer successfully decreases the gate leakage current and enables a more positive gate bias of up to $+$4 V, which is advantageous to achieve a higher drain current. Moreover, the n-GaN capping layer between gate and ohmic electrodes helps to reduce parasitic resistance and suppress current collapse. The fabricated $a$-plane MIS-HFET exhibits a threshold voltage of $+$ 1.3 V with a high drain current of 112 mA/mm. The presented MIS-HFETs will be desirable in next-generation radio-frequency and power switching application fields.