Microbolometer Terahertz Focal Plane Array and Camera with Improved Sensitivity in the Sub-Terahertz Region

Journal of Infrared, Millimeter, and Terahertz Waves - A pixel in an uncooled microbolometer terahertz (THz) focal plane array (FPA) has a suspended structure above read-out integrated circuit...     

Observations of Vortex Emissions from Superfluid 4He Turbulence at High Temperatures

An immersed object with high velocity oscillations causes quantum turbulence in superfluid ⁴He, even at very low temperatures. The continuously generated turbulence may emit vortex rings from a turbulent region. In the present work, we report vortex emissions from quantum turbulence in superfluid ⁴He at high temperatures, by using three vibrating wires as a turbulence generator and vortex detectors. Two detector wires were mounted beside a generator wire: one in parallel and the other in perpendicular to the oscillation direction of the generator. The detection times of vortex rings represent an exponential distribution with a delay time t ₀ and a mean detection period t ₁. The delay time includes the generation time of a fully developed turbulence and the time-of-flight of a vortex ring. At high temperatures, vortices are dissipated by relative motion between a normal fluid component and the vortices, resulting that only large vortex rings are reachable to the detectors. Using this method, we detected vortex rings with a diameter of 100 μm, comparable to a peak-to-peak vibration amplitude of 104 μm of the generator. The large vortices observed here are emitted anisotropically from the generator. The emissions parallel to the vibrating direction are much less than those perpendicular to the direction.     

Preparation and characterization of carbonaceous materials containing nitrogen as electrochemical capacitor

Carbonaceous materials containing nitrogen (C/N materials) were prepared by a pyrolysis of 2,3,6,7-tetracyano-1,4,5,8-tetraazanaphthalene (CAN). A C/N material prepared by the pyrolysis of CAN at 1070 K (CAN-1070 K) had a C/N atomic ratio of 3.0 and a non-crystalline carbonaceous structure with a BET surface area of 880 m² g⁻¹. The material CAN-1070 K showed large capacitances of 160–180 F g⁻¹ and 110–120 F cm⁻³ in case of current density of 10 mA cm⁻² (2 A g⁻¹) by using three-electrode cell in 1 M H₂SO₄ aqueous solution, in comparison with that of activated carbon (160 F g⁻¹ and 55 F cm⁻³) having BET surface area of 2300 m² g⁻¹. ESCA study indicated that pyridinic and quarternary nitrogen atoms existed in the C/N materials, which could result in producing a pseudo-capacitance in addition to the electric double layer capacitance. Also introduction of nitrogen into the carbonaceous material could enhance the wettability of material, which might also improve the capacitance.     

Production-scale purification of the recombinant major house dust mite allergen Der f 2 mutant C8/119S

A WHO position paper states that allergen immunotherapy is an effective treatment for allergic diseases, and well characterized allergens should be used in immunotherapy. The house dust mite is a major cause of allergic disease. However, the biological activity of the mite extracts currently used cannot be clearly determined, since these extracts contain various impurities. The use of recombinant allergens can avoid this problem. However, there remains a risk of contamination by other impurities, such as host cell-derived proteins (HCPs). Advanced purification techniques are thus required to remove these contaminants. C8/119S is a mutant of the major house dust mite allergen Der f 2, and is expressed and accumulated as an inclusion body in Escherichia coli. The C8/119S was refolded and purified through three column chromatography steps. Using this method, we could obtain about 2 g of the purified C8/119S in one purification batch. This amount is equivalent to 100,000 of the maintenance doses required for immunotherapy based on the WHO position paper. The purity of the C8/119S was 99% or more. The antigenicity of HCPs in the C8/119S was examined by passive cutaneous anaphylaxis assays. When the C8/119S was administered at 40 μg/kg, no local anaphylaxis was observed. C8/119S was thus highly purified with an extremely low level of impurities, and our procedure was shown to be an effective advanced production-scale purification process for this Der f 2 mutant. In this study, we established an advanced purification processes for C8/119S, then characterized the purified C8/119S and evaluated its purity.     

Enhancement of the nitrogen fixation efficiency of genetically-engineered Rhizobium with high catalase activity

The vktA catalase gene, which had been cloned from Vibrio rumoiensis S-1^T having extraordinarily high catalase activity, was introduced into the root nodule bacterium, Rhizobium leguminosarum bv. phaseoli USDA 2676. The catalase activity of the vktA-transformed R. leguminosarum cells (free-living) was three orders in magnitude higher than that of the parent cells and this transformant could grow in a higher concentration of exogenous hydrogen peroxide (H₂O₂). The vktA-transformant was inoculated to the host plant (Phaseolus vulgaris L.) and the nodulation efficiency was evaluated. The results showed that the nitrogen-fixing activity of nodules was increased 1.7 to 2.3 times as compared to the parent. The levels of H₂O₂ in nodules formed by the vktA-transformant were decreased by around 73%, while those of leghemoglobins (Lba and Lbb) were increased by 1.2 (Lba) and 2.1 (Lbb) times compared with the parent. These results indicated that the increase of catalase activity in rhizobia could be useful to improve the nitrogen-fixing efficiency of nodules by the reduction of H₂O₂ content concomitantly with the enhancement of leghemoglobins contents.     

Fluorescence Imaging Using Enzyme-Activatable Probes for Detecting Diabetic Kidney Disease and Glomerular Diseases

A clear identification of the etiology of glomerular disease is essential in patients with diabetes. Renal biopsy is the gold standard for assessing the underlying nephrotic pathology; however, it has the risk for potential complications. Here, we aimed to investigate the feasibility of urinary fluorescence imaging using an enzyme-activatable probe for differentiating diabetic kidney disease and the other glomerular diseases. Hydroxymethyl rhodamine green (HMRG)-based fluorescent probes targeting gamma-glutamyl transpeptidase (GGT) and dipeptidyl-peptidase (DPP) were used. Urinary fluorescence was compared between groups which were classified by their histopathological diagnoses (diabetic kidney disease, glomerulonephritis, and nephrosclerosis) as obtained by ultrasound-guided renal biopsy. Urinary fluorescence was significantly stronger in patients with diabetic kidney disease compared to those with glomerulonephritis/nephrosclerosis after DPP-HMRG, whereas it was stronger in patients with nephrosclerosis than in patients with glomerulonephritis after GGT-HMRG. Subgroup analyses of the fluorescence performed for patients with diabetes showed consistent results. Urinary fluorescence imaging using enzyme-activatable fluorescence probes thus represents a potential noninvasive assessment technique for kidney diseases in patients with diabetes.     

A small engineered protein lacks structural uniqueness by increasing the side-chain conformational entropy

A small globular protein, the third repeat of the c-Myb DNA-binding domain, which is composed of 54 amino acid residues, was engineered so as to understand the structural uniqueness of native proteins. This small protein has three alpha-helices that form a helix-turn-helix structure, which is maintained by the hydrophobic core with three Ile residues. One of the mutant proteins, with two of the buried Ile (Ile-155 and Ile-181) substituted with Leu residues, showed multiple conformations, as monitored by heteronuclear magnetic resonance spectroscopy for 13C- and 15N-labeled proteins. The increase in the side-chain conformational entropy, caused by changing the Ile to a Leu residue on an alpha-helix, could engender the lack of structural uniqueness. In native proteins, the conformations of not only the beta-branched side chains, but also those of the neighboring bulky side chains, can be greatly restricted, depending upon the local backbone structure.     

Effect of solid-state fermentation on select antinutrients and protein digestibility of cold-pressed and hexane-extracted canola meals

In this study, the effects of solid-state fermentation (SSF), including strain (Aspergillus niger NRRL 334 and A. oryzae NRRL 5590) and fermentation time (24, 48, and 72 h) on the nutritional value of cold-pressed (CP) and hexane-extracted (HE) canola meals were examined. SSF increased the protein content of both types of meals (from ~36% to ~40%) while reducing the oil content of CP meals (from ~12% to 9%). There was a significant reduction (~80%) in the phytic acid content of both types of meals after fermentation using either fungi. Overall, fermented samples showed a decrease in the total phenolic content from 2.7–3.1 to ~1.0 mg gallic acid equivalents (GAE)/g dry meal (DM) (a ~65% reduction), of which specifically the HE meal fermented with A. niger sample had the greatest decrease from 3.1 to 0.6 mg GAE/g DM (~81% reduction). Seventy-two hours of fermentation decreased the in vitro protein digestibility (IVPD) of A. oryzae fermented meals. In contrast, a shorter fermentation time (24 h) increased the IVPD for most samples as compared to the controls (from ~72%–73% to 77%–81%), with the exception of the CP meal fermented with A. niger which had similar IVPD at all fermentation times. Overall, the changes indicate that SSF using A. niger or A. oryzae can be useful to positively modify the composition of different canola meals and improve their nutritional value by significantly increasing the protein content, decreasing the levels of antinutrients, while only slightly reducing IVPD.     

Development of energy saving operation technology for punctuality and ride comfort by optimizing the point of target pattern recreation

At present, there is a growing demand for energy saving to prevent global warming. Thus, the railway industry is also focusing on energy saving methods. Power consumption of running trains has a large variation of approximately 20% caused by drivers’ operation. Therefore, improving the running profile can considerably reduce energy consumption. Numerous algorithms for generating energy saving running profiles have been researched and developed. To adapt energy saving operation to various environments, we developed a technology that maintains punctuality without reducing the energy efficiency when temporary differences occur in driving conditions. We propose a method that determines the re-creation command point to complete the re-creation at the switching point of the driving operation in the existing energy-saving target pattern, to achieve both punctuality and ride comfort. As a result of verifying the effect of the proposed method on the conventional method via a simulation, it was confirmed that the proposed method can prevent the increase in the number of operation changes when the driving conditions change, whereas the conventional method increases the number of operation changes.     

S-Denitrosylase-Like Activity of Cyclic Diselenides Conjugated with Xaa-His Dipeptide: Role of Proline Spacer as a Key Activity Booster

This study developed dipeptide-conjugated 1,2-diselenan-4-amine ( 1 ), i. e., 1 -Xaa-His, as a new class of S-denitrosylase mimic. The synthesized compounds, especially 1 -Pro-His, remarkably promoted S-denitrosylation of nitrosothiols (RSNO) via a catalytic cycle involving the reversible redox reaction between the diselenide and its corresponding diselenol ([SeH,SeH]) form with coexisting reductant thiols (R′SH), during which the [SeH,SeH] form as a key reactive species reduces RSNO to the corresponding thiol (RSH). Structural analyses of 1 -Pro-His suggested that the peptide backbone of [SeH,SeH] is rigidly bent to form a γ-turn, possibly including an NH⋅⋅⋅Se hydrogen bond between the imidazole ring of His and selenol group, thus stabilizing the [SeH,SeH] form thermodynamically, and dramatically enhancing the catalytic activity. Furthermore, the synthetic compounds were found to prohibit S-nitrosylation-induced protein misfolding in the presence of RSNO, eventually implying their potential as a drug seed for misfolding diseases caused by the dysregulation of the S-denitrosylation system.