Optical flip-flop and astable nultivibrator functions by vertical and direct integration of heterojunction phototransistors and laser diodes

A optoelectronic integrated device in which six heterojunction phototransistors and two laser diodes are vertically and directly integrated is developed to achieve new functions important for optical signal processing and optical computing. It is demonstrated that the device has a bistable flip-flop function, in which the output portion is switched alternately by the corresponding optical input. The function is extended to a tristable flip-flop, which is especially important for multistable logic, by using multiple HPTS and their internal optical and/or electrical couplings. Moreover, an astable multivibrator function or a self-oscillating function, is successfully demonstrated by applying the interconnecting technique to the bistable flip-flop function.     

Kl3 semileptonic form factor from (2+1)-flavor lattice QCD

We present the first results for the K13 form factor from simulations with 2+1 flavors of dynamical domain wall quarks. Combining our result, namely, f+(0)=0.964(5) with the latest experimental results for Kl3 decays leads to |V us|=0.2249(14), reducing the uncertaintity in this important parameter. For the O(p6) term in the chiral expansion we obtain Delta f=-0.013(5).     

Determination of silver in biological materials by high-frequency plasma-torch emission spectrometry

Nanogram amounts or silver in small samples of biological materials can be determined by high-frequency plasma-torch emission spectrometry. Samples are digested with perchloric and nitric acids, silver is collected with a bismuth iodide carrier, and the precipitate is decomposed with concentrated nitric acid before dilution. Bismuth shows an enhancing effect on the silver emission at 328.06 nm, and the sensitivity is further improved by elimination of moisture in the aerosol with a second condenser at -3 to -5°C. The detection limit is 0.5 ng per 0.2 ml of sample solution. Condensed milk and whole blood were analyzed satisfactorily.     

Uptake of 67Ga into the rat liver after treatment with thioacetamide

67Ga uptake of the liver began to elevate from the 1st day and reached a maximum at the 2nd day of treatment with thioacetamide (TIAA). Incorporation of 3H-thymidine into the liver DNA fraction was reached a maximum at the 1.5th day, and the value was 5.7 times of the control. The uronic acid content and 35S incorporation in the 1.2 M NaCl-soluble fraction which contained predominantly heparan sulfate (HS), were both peaked at the 2nd day. These patterns were in good agreement with that of 67Ga uptakes in the liver treated with TIAA. Pretreatment of aminoacetonitrile, an inhibitor of fibrosis, was effective in lowering the elevated uptake of 67Ga in TIAA-treated rat liver. Uptake of the 67Ga in the TIAA-treated liver was also inhibited when they were treated with cycloheximide, an inhibitor of protein synthesis. On the other hand no significant inhibition was observed in the cytosine arabinoside-treated-TIAA rats. These results suggest that HS may be involved in the 67Ga uptake in damaged liver, and that relation between 67Ga uptake and cell proliferation is secondary.     

Total synthesis and complete stereostructure of gambieric acid A

Total synthesis of gambieric acid A, a potent antifungal polycyclic ether metabolite, has been accomplished for the first time, which firmly established the complete stereostructure of this natural product.     

Isolation and quantification of messenger RNA from tissue models by using a double-barrel carbon probe

In this study, we introduce the double-barrel carbon probe (DBCP)—a simple, affordable microring electrode—which enables the collection and analysis of single cells independent of cellular positioning. The target cells were punctured by utilizing an electric pulse between the two electrodes in DBCP, and the cellular lysates were collected by manual aspiration using the DBCP. The mRNA in the collected lysate was evaluated quantitatively using real-time PCR. The histograms of single-cell relative gene expression normalized to GAPDH were fit to a theoretical lognormal distribution. In the tissue culture model, we focused on angiogenesis to prove that multiple gene expression analysis was available. Finally, we applied DBCP for the embryonic stem (ES) cell-derived cardiomyocytes to substantiate the capability of the probe to collect cells, even from high-volume samples such as spheroids. This method achieves high sensitivity for mRNA at the single-cell level and is applicable in the analysis of various biological samples independent of cellular positioning.