Effective mass anomalies in strained Si thin films and crystals

Effective mass anomalies due to the geometrical effects are investigated in silicon nanostructures using first-principles calculations for the first time. In \{111\} and \{110\} biaxially strained Si, it is found that longitudinal effective mass is extraordinarily enhanced for both thin films and crystals. This mass enhancement is caused by the change of the band structure with double minima into that with a single minimum due to strain and confinement. At the transition point, it is analytically shown that the effective mass diverges. The dependences of the confinement thickness on the anomalies are qualitatively explained by an extension of the effective mass approximation.Comment: 4 pages, 5 figures, submitted to Phys. Rev. Let

The 3-D image recognition based on fuzzy neural network technology

Three dimensional stereoscopic image recognition system based on fuzzy-neural network technology was developed. The system consists of three parts; preprocessing part, feature extraction part, and matching part. Two CCD color camera image are fed to the preprocessing part, where several operations including RGB-HSV transformation are done. A multi-layer perception is used for the line detection in the feature extraction part. Then fuzzy matching technique is introduced in the matching part. The system is realized on SUN spark station and special image input hardware system. An experimental result on bottle images is also presented

Discovery of a Transient X-Ray Pulsar, AX J1841.0-0536, in the Scutum Arm Region with ASCA

We report on the discovery of a transient X-ray pulsar, AX J1841.0-0536, serendipitously found in the Scutum arm region with the ASCA in two separate observations. The X-ray flux is very faint at the beginning, but exhibits two flares in the second observation. The flare flux increases by a factor 10 within only about 1 hr. Coherent pulsations with a period of 4.7394 plus/minus 0.0008 s were detected in the brightest flare phase. The X-ray spectra in the quiescent and flare phases were fitted with an absorbed power-law model with a photon index about 1 plus a narrow Gaussian line at the center energy of 6.4 keV. The interstellar column density of about 3E22 /cm2 may indicate that AX J1841.0-0536 is located at a tangential point of the Scutum arm at about 10 kpc distance. The coherent pulsations, large flux variability and the spectral shape suggest that AX J1841.0-0536 is a Be/X-ray binary pulsar.Comment: 5 pages, 8 figures, uses pasj00.cls; accepted by Publication of the Astronomical Society of Japa

The nanoparticulation by octaarginine-modified liposome improves α-galactosylceramide-mediated antitumor therapy via systemic administration

AbstractAlpha-galactosylceramide (αGC), a lipid antigen present on CD1d molecules, is predicted to have clinical applications as a new class of adjuvant, because αGC strongly activates natural killer T (NKT) cells which produce large amounts of IFN-γ. Here, we incorporated αGC into stearylated octaarginine-modified liposomes (R8-Lip), our original delivery system developed for vaccines, and investigated the effect of nanoparticulation. Unexpectedly, the systemic administered R8-Lip incorporating αGC (αGC/R8-Lip) failed to improve the immune responses mediated by αGC compared with soluble αGC in vivo, although αGC/R8-Lip drastically enhanced αGC presentation on CD1d in antigen presenting cells in vitro. Thus, we optimized the αGC/R8-Lip in vivo to overcome this inverse correlation. In optimization in vivo, we found that size control of liposome and R8-modification were critical for enhancing the production of IFN-γ. The optimization led to the accumulation of αGC/R8-Lip in the spleen and a positive therapeutic effect against highly malignant B16 melanoma cells. The optimized αGC/R8-Lip also enhanced αGC presentation on CD1d in antigen presenting cells and resulted in an expansion in the population of NKT cells. Herein, we show that R8-Lip is a potent delivery system, and size control and R8-modification in liposomal construction are promising techniques for achieving systemic αGC therapy

Bis(2,3,5-triphenyl­tetra­zolium) tetra­thio­cyanato­cobaltate(II)

The title compound, (C19H15N4)2[Co(NCS)4], has two crystallographycally different molecules of bis­(2,3,5-triphenyl­tetra­zolium) tetra­thio­cyanatecobaltate in the asymmetric unit. There are only minor geometric differences between them. Each cobalt(II) ion is coordinated by the N atoms of four NCS anions, showing the magnitude of the magnetic moment expected from the NCS− crystal field strength

Accessibility Service Utilization Rates in Android Applications Shared on Twitter

The number of malware detected has been increasing annually, and 4.12% of malware reported in 2018 attacked Android phones. Therefore, preventing attacks by Android malware is critically important. Several previous studies have investigated the percentage of apps that utilize accessibility services and are distributed from Google Play, that have been reportedly used by Android malware. However, the Social Networking Services (SNSs) that are used to spread malware have distributed apps not only from Google Play but also from other sources. Therefore, apps distributed from within and outside of Google Play must be investigated to capture malware trends. In this study, we collected apps shared on Twitter in 2018, which is a representative SNS, and created a Twitter shared apps dataset. The dataset consists of 32,068 apps downloaded from the websites of URLs collected on Twitter. We clarified the proportion of apps that contained malware and proportion of apps utilizing accessibility services. We found that both, the percentage of malware and percentage of total apps using accessibility services have been increasing. Notably, the percentages of malware and un-suspicious apps using accessibility services were quite similar. Therefore, this problem cannot be solved by automatically blocking all apps that use accessibility services. Hence, specific countermeasures against malware using accessibility services will be increasingly important for online security in the future