Development of Superconducting Multilayer Wiring for Large Arrays of TES X-Ray Microcalorimeters

We are developing TES (Transition Edge Sensor) X-ray Microcalorimeters for future X-ray astronomy missions such as DIOS (Diffuse Intergalactic Oxygen Surveyor). Standard wiring for a large-format array requires narrow and closely-packed configuration. This can cause deleterious crosstalk especially in the Frequency Domain Multiplexing readout. Hence we have employed multilayer wiring technique. In this paper, we tested a deposition of a TES film on the multilayer wiring by sputtering. Our first trial showed that the TES pixels have large residual resistances >50?mΩ and small critical currents of <1?μA. To improve the coverage of the TES film on the wiring, we increased the thickness of TES film (Ti/Au thickness of 100/200?nm). Also to remove an oxidation layer on the Al wiring, we strengthened a reverse-sputtering (150 W, 3?min) before the sputtering of TES. After these treatments, the TES film showed a sharp transition with small residual resistance (～1?mΩ) and large critical current (>30?μA).     

Evaluation on fatigue strength of AISI 4340 steel aluminum coated by electroplating and IVD processes

In spite of toxicity, hydrogen embrittlement susceptibility, and environmental issues, cadmium electroplating is usually applied on high strength AISI 4340 aeronautical steel due to its efficient protection against electrochemical corrosion. Ion vapor deposition (IVD) process with pure aluminum also offers good protection against corrosion with the advantages of decreasing hydrogen embrittlement susceptibility and improving the fatigue strength of metallic components. In this research, the effects of aluminum electroplating and IVD aluminum coating on the rotating bending fatigue strength of AISI 4340 steel were evaluated in comparison with cadmium electroplated specimens. Experimental fatigue results showed that both aluminum electroplating and IVD aluminum coatings are possible alternatives to cadmium electroplating.     

Measurement of Liquid Film Thickness by a Fringe Method

A technique was developed and tested to measure the local thickness of a droplet or a liquid film on a surface of an opaque or thick single transparent plate by an interference fringe pattern that was easily formed by reflecting laser lights. Monochromatic epi-illumination through an objective lens of a conventional microscope was provided by a 5 mW or 300 mW laser and a filter to remove the noise caused by laser speckle. The incremental height difference of the liquid layer between neighboring maxima or minima of fringes was evaluated from the wavelength of the laser light and the refractive index of the liquid. Estimation error of a local inclination angle was discussed using ray tracing under parallel illumination approximation. Droplet profiles evaluated from the interferogram that were obtained by the present fringe method agreed well with those by Laser Focus Displacement Meter. Measurement was made to ensure the usefulness of the present technique. It was made clear that the contact angle of a liquid droplet could be obtained precisely and swiftly, even in small size or small contact angle, and that instantaneous three-dimensional profile of a liquid film on a bubble moving in a microchannel could be measured. The fringe method had sufficient potential to obtain more detailed information about three-dimensional characteristics of liquid film in flows such as the generation, breakdown, and growth of waves and the liquid film on a bubble at the beginning of movement.     

Performance Measurement of the 8-Input SQUIDs for TES Frequency Domain Multiplexing

We report on performance of 8-input superconducting quantum interference devices (SQUIDs) for multiplexing transition-edge sensor signals by using frequency-domain multiplexing. We found the typical critical current and the flux noise to be 17–19 μA and 0.7–1.1 μ , respectively. We also measured the crosstalk current between the input coils of the SQUIDs, and found that the mutual inductance was consistent with the design value, 800 pH. We confirmed that the cross talk current due to the mutual inductance was reduced by the flux-locked-loop (FLL) feedback, and its reduction rate was consistent with 1/(1+ℒ), where ℒ is the FLL feedback gain. We also show the result of 2-channel DC-driven TES signals readout using the 8-input SQUIDs.      

Combination effect of phospholipids and n-3 polyunsaturated fatty acids on rat cholesterol metabolism

This study evaluated phospholipids (PLs) containing n-3 polyunsaturated fatty acids (n-3 PUFAs) for their specific inherent effects and effects due to a combination of the presence of glycerophosphate structure and n-3 PUFAs on cholesterol metabolism in rats. Rats were fed a diet of AIN-93G containing soybean oil (SO, 7%), SO (5.8%)+fish oil (1.2%), SO (5.2%)+soybean PLs (1.8%), SO (5.2%)+PLs containing n-3 PUFAs (1.8%), and SO (4.0%)+fish oil (1.2%)+soybean PLs (1.8%). Diets with PLs containing n-3 PUFAs, and soybean PLs in combination with fish oil, resulted in decreased serum and liver cholesterol levels through enhancement of fecal cholesterol excretion and suppression of liver sterol regulatory element binding protein-2 mRNA expression compared with the diet containing soybean oil alone. This study shows that soybean PLs with added triacylglycerol that included n-3 PUFAs have the same effects on cholesterol metabolism as PLs containing n-3 PUFAs, and that these could be of benefit to people.     

Development of a microchannel catalytic reactor system

The purpose of this article is to demonstrate the applicability of microreactors for use in catalytic reactions at elevated temperatures. Microchannels were fabricated on both sides of a silicon wafer by wet chemical etching after pattern transfer using a negative photoresist. The walls of the reactor channel were coated with a platinum layer, for use as a sample catalyst, by sputtering. A heating element was installed in the channel on the opposite surface of the reactor channel. The reactor channel was sealed gas-tight with a glass plate by using an anodic bonding technique. A small-scale palladium membrane was also prepared on the surface of a 50-Μm thick copper film. In the membrane preparation, a negative photoresist was spin-coated and solidified to serve as a protective film. A palladium layer was then electrodeposited on the other uncovered surface. After the protective film was removed, the resist was again spin-coated on the copper surface, and a pattern of microslits was transferred by photolithography. After development, the microslits were electrolitically etched away, resulting in the formation of a palladium membrane as an assemblage of thin layers formed in the microslits. The integration of the microreactor and the membrane is currently under way.     

Phenolic composition,antiproliferative and antiulcerogenic activities of a polyphenol-rich purified extract from açai (Euterpe oleracea) fruits

The bioactivity and phytochemical composition of a partially purified extract of açai (PPEA), concentrated in phenolic compounds (PC) and without the presence of macronutrients, were investigated. The major PC quantified by UHPLC-DAD-LTQ-Orbitrap MS-MS/MS in the PPEA are anthocyanins. In vitro, PPEA showed a cytostatic effect on the K-562 lymphoid leukaemia at a concentration of 40 μg PC mL⁻¹, with a GI₅₀ equal to 1.08 μg PC mL⁻¹. In vivo, the extract did not promote acute toxicity in mice in any of the doses tested. The extract displayed gastroprotective activity in rats treated orally with 16, 48 and 160 mg PC kg⁻¹, with a significant decrease in the ulcerative lesion index, compared with the negative control. The lack of toxicity and the bioactivity of the PPEA show that this extract is beneficial to health and useful as a commercial food additive containing natural violet colourant, with pharmaceutical and functional potentials.     

Evaluation of Naturally Occurring HIF-1 Inhibitors for Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a rare and severe progressive disorder characterized by high pulmonary artery pressure. Chronic hypoxia causes a metabolic disorder and the Warburg effect in pulmonary arterial smooth muscle cells (PASMCs). Pyruvate dehydrogenase kinase 1 (PDK1) is a key enzyme in Warburg effect increased by hypoxia-inducible factor (HIF-1). We constructed a cell-based luciferase assay system for HIF-1 inhibitors. Using this system, six HIF-1 inhibitors were identified. Among these inhibitors, the effect of tagitinin C ( 1 ) on PASMC was investigated. Tagitinin C ( 1 ) clearly decreased the amount of HIF-1β and the HIF-1 target PDK1. This result indicates that HIF-1 inhibitors effectively decrease PDK1 activity, which is a cause of the metabolic disorder and Warburg effect observed in PASMCs. Identifying naturally occurring HIF-1 inhibitors could provide novel insights into the development of PAH medications.     

Extracranial vertebral artery aneurysm complicating Klippel-Feil syndrome: case report]

The Klippel-Feil syndrome is one of the spinal malformations characterized by fusion of the cervical vertebrae. It is well known that the malformation can cause some neurologic disorders. However, an aneurysm in the vertebral artery associated with the Klippel-Feil syndrome is extremely rare, with only one case having been reported in the literature. We present a 39-year-old female with a sudden onset of disturbed consciousness. Lateral cervical x-ray films showed the Klippel-Feil syndrome and hypermobility between C1 and C2. MRI showed multiple infarctions in the posterior circulation, including bilateral thalami. Right vertebral angiogram identified the extracranial vertebral artery aneurysm as the source of the emboli. The patient gradually recovered with conservative therapy. The aneurysm was thought to be produced by chronic arterial trauma secondary to excessive movement between C1 and C2. We conclude that an extracranial vertebral artery aneurysm is a serious complication in a patient with the Klippel-Feil syndrome.