Selective Transfer of Si Thin-Film Microchips by SiO₂ Terraces on Host Chips for Fluidic Self-Assembly

Fluidic self-assembly is a versatile on-chip integration method. In this scheme, a large number of semiconductor microchips are spontaneously deposited onto a host chip. The host chip typically comprises a Si substrate with an array of pockets at the designated microchip placement sites. In this study, we installed an SiO₂ layer on the terrace region between the pockets of the host chip, to reduce the attraction with the Si microchips. By the SiO₂-topped terrace scheme, we demonstrated a significant enhancement in the deposition selectivity of the Si microchips to the pocket sites, relative to the case of the conventional Si-only host chip. We theoretically explained the deposition selectivity enhancement in terms of the van der Waals interaction. Furthermore, our quantitative analysis implicated a potential applicability of the commonly used interlayer dielectrics, such as HfO₂, silsesquioxanes, and allyl ethers, directly as the terrace component

The Quiescent Intracluster Medium in the Core of the Perseus Cluster

Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July

Photosynthetic production of enantioselective biocatalysts

$\bf Background:$ Global resource depletion poses a dramatic threat to our society and creates a strong demand for alternative resources that do not compete with the production of food. Meeting this challenge requires a thorough rethinking of all steps of the value chain regarding their sustainability resource demand and the possibility to substitute current, petrol-based supply-chains with renewable resources. This regards also the production of catalysts for chemical synthesis. Phototrophic microorganisms have attracted considerable attention as a biomanufacturing platform for the sustainable production of chemicals and biofuels. They allow the direct utilization of carbon dioxide and do not compete with food production. Photosynthetic enzyme production of catalysts would be a sustainable supply of these important components of the biotechnological and chemical industries. This paper focuses on the usefulness of recombinant cyanobacteria for the photosynthetic expression of enantioselective catalysts. As a proof of concept, we used the cyanobacterium $\it Synechocystis$ sp. PCC 6803 for the heterologous expression of two highly enantioselective enzymes. $\bf Results:$ We investigated the expression yield and the usefulness of cyanobacterial cell extracts for conducting stereoselective reactions. The cyanobacterial enzyme expression achieved protein yields of 3% of total soluble protein (%TSP) while the expression in $\textit {E. coli}$ yielded 6-8% TSP. Cell-free extracts from a recombinant strain expressing the recombinant esterase ST0071 from the thermophilic organism $\textit {Sulfolobus tokodai}$ ST0071 and arylmalonate decarboxylase from $\textit {Bordetella bronchiseptica}$ showed excellent enantioselectivity (>99% ee) and yield (>91%) in the desymmetrisation of prochiral malonates. $\bf Conclusions:$ We were able to present the proof-of-concept of photoautotrophic enzyme expression as a viable alternative to heterotrophic expression hosts. Our results show that the introduction of foreign genes is straightforward. Cell components from $\it Synechocystis$ did not interfere with the stereoselective transformations, underlining the usability of photoautotrophic organisms for the production of enzymes. Given the considerable commercial value of recombinant biocatalysts, cyanobacterial enzyme expression has thus the potential to complement existing approaches to use phototrophic organisms for the production of chemicals and biofuels

Hitomi (ASTRO-H) X-ray Astronomy Satellite

The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E  >  2  keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month

Ionospheric hole made by the 2012 North Korean rocket observed with a dense GNSS array in Japan

A dense array of Global Navigation Satellite System (GNSS) receivers is useful to study ionospheric disturbances. Here we report observations by a Japanese GNSS array of an ionospheric hole, i.e., localized electron depletion, made by water vapor molecules in the exhaust plume of the second-stage engine of the Unha-3 rocket launched from North Korea, on 12 December 2012. The Russian GNSS was used for the first time to observe such an ionospheric hole. The hole emerged similar to 6 min after the launch above the middle of the Yellow Sea, and its size and depth suggest that the Unha-3 is slightly less powerful than the 2009 Taepodong-2 missile, also from North Korea. Smaller-scale electron depletion signatures appeared similar to 10 min after the launch above the southern East China Sea, which is possibly caused by the exhaust plume of the third-stage engine

How ’Straight’ Has Developed Its Meanings －Based on a metaphysical theory

This paper makes the development of the word ’straight’ clear. Dictionaries define ’straight’ as; ‘without a curve or bend’, ‘going direct to the target’, ‘honest’, ‘in continuous succession’ or ‘neat’. As can be seen, ’straight’ has a variety of meanings. Some connections between these meanings can be guessed but others cannot. The mechanism of how ’straight’ has obtained each meaning will be explained logically in this paper. First, the most basic or central meaning of ’straight’ is ‘without a curve or bend’. So ’straight’ modifies the verb ’stand’ like the following: He stood up straight. ’Straight’ has a strong conceptual connection with a standing posture. At the present time, ’straight’ is the normal posture for human beings. This means ’straight’ has a concept for ‘normal’ for human beings like the following: He grew up straight. This sentence does not mean that his posture is straight up. It means that he grew up honest. ’Straight’ gives a normal image to English speakers both physically and metaphysically. Like an example above, this paper explains how ’straight’ has developed its meanings through the human beings’ way of thinking. And some comparisons between English expressions and Japanese ones, which is the author’s mother tongue, are made in this paper as well

Harmonic ionospheric oscillation by the 2010 eruption of the Merapi volcano, Indonesia, and the relevance of its amplitude to the mass eruption rate

Using continuous data from ground-based Global Satellite Navigation System (GNSS) receivers in Java and Sumatra, Indonesia, we studied the response of ionospheric total ionospheric electron content (TEC) to the 2010 Nov.5 eruption of the Merapi volcano in central Java. We then compared the results with the case of the 2014 Feb.13 eruption of the Kelud volcano, eastern Java. The TEC showed a quasi-periodic oscillation of a frequency ~4 mHz with average amplitudes of 0.9 and 1.8% relative to background values lasting for ~20 and ~ 120 min for the Merapi and Kelud eruptions, respectively. By comparing the two cases, together with the 2015 April eruption of the Calbuco volcano, Chile, we found the relative TEC oscillation amplitude may scale with the mass eruption rate. This suggests that the product of such TEC oscillation amplitude and the duration provides a new measure for the total volume of the volcanic deposits