Regulation of GluA1 AMPA Receptor Through PKC Phosphorylation Induced by Free Fatty Acid Derivative HUHS2002

The present study investigated the effect of 4-[4-(Z)-hept-1-enyl-phenoxy] butyric acid (HUHS2002), a newly synthesized free fatty acid derivative, on α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor responses. HUHS2002 potentiated currents through GluA1 AMPA receptors expressed in Xenopus oocytes in a bell-shaped concentration (1 nM–1 μM)-dependent manner, the maximum reaching nearly 140 % of original amplitude at 100 nM. The potentiation was significantly inhibited by GF109203X, an inhibitor of protein kinase C (PKC), but not KN-93, an inhibitor of Ca²⁺/calmodulin-dependent protein kinase II (CaMKII). HUHS2002 had no potentiating effect on currents through mutant GluA1 AMPA receptors with replacement of Ser831, a PKC/CaMKII phosphorylation site, by Ala. In the in situ PKC assay using rat PC-12 cells, HUHS2002 significantly enhanced PKC activity, that is suppressed by GF109203X. Overall, the results of the present study show that HUHS2002 potentiates GluA1 AMPA receptor responses by activating PKC and phosphorylating the receptors at Ser831, regardless of CaMKII activation and phosphorylation.     

Evaluation of neutron economical effect of new cladding materials in light water reactors

The present paper aims to contribute from a neutronic aspect to activities for new cladding material development for light water reactors (LWRs) that can reduce the risk of hydrogen gas explosion. Iron (Fe), nickel (Ni), titanium (Ti), niobium (Nb) and vanadium (V) are selected as possible component elements to cover a variety of new cladding materials for LWRs. The effect of larger thermal absorption cross sections of these elements than those of zirconium (Zr), together with those of silicon carbide (SiC), on the neutron economy in LWRs is evaluated by performing pin cell burnup calculations for a conventional pressurized water reactor (PWR), a low-moderation high-burnup LWR (LM-LWR) and a high-moderation high-burnup LWR (HM-LWR). As can be anticipated from the thermal cross sections, SiC has excellent neutron economy. The materials other than SiC largely decrease discharge burnup for all three types of LWRs in comparison with Zircaloy-4. Among such elements of larger thermal absorption cross section, Nb has neutron economical advantage over the other materials except SiC in softer neutron spectrum reactors such as HM-LWR in which the atomic number ratio of hydrogen to heavy metal is 6. In conventional LWRs, stainless steel of low Ni contents has the neutron economic advantage as well as Nb for cladding material. The results of the calculations are summarized for the purpose to provide reference data for new cladding material development studies, in terms of the relation between fuel enrichment and cladding thickness from the viewpoint to achieve the same discharge burnup as the Zircaloy cladding.     

Direct deposition of two nanomaterials with the same surface charge using a liquid-liquid interface

Two negatively charged nanoparticles (SDS-coated SWCNT and polydiacetylene nanocrystals) were sequentially adsorbed onto the same water-hexane interface. The absorbed film can be transferred onto a solid substrate. Repeating the adsorption and transfer process enables assembly of the two nanoparticles in a layer-by-layer growth fashion up to three bi-layers.     

Broad-band extreme ultraviolet lithography with a wet-silylated and dry-developed resist

Broad-band extreme ultraviolet (1340nm) lithography (EUVL) has been examined. Exposure intensity at the broad-band of 1340nm was 20 times larger than at the conventional narrow-band of 13nm. Moreover, broad-band EUVL with a wet-silylated and dry-developed resist process has been investigated in order to obtain a high resolution of 0.1μm with high-aspect-ratio. Imaging experiments were performed using 32:1 reduction Schwarzschild optics illuminated with a synchrotron radiation light source from SORTEC ring. The exposure was done through a 0.1μm-thick SiN vacuum window, Mo/Si multilayer coated optics and without a Be filter. Silylation characterization and determination of optimum composition of the silylation solution have been performed using Fourier transform infrared spectroscopy (FTIR). Using broad band EUVL with the optimal wet-silylated and dry-developed resist, 0.1μm lines and spaces of 0.55μm-thick resist (aspect RATIO = 5.5) can be successfully delineated.     

Low-temperature deposition of SiO2 films using plasma-enhanced oxygen with reduction of oxygen-originated damage

Plasma-enhanced chemical vapor deposition of SiO₂ with well-suppressed subcutaneous oxidation is demonstrated to be a promising technology for eliminating defect generation and fabricating thin gate SiO₂ films by means of a totally low-temperature process. An anomalous increase in electron density was observed in Si substrates irradiated by plasma-activated oxygen during the formation of gate SiO₂ films using an ultrahigh-vacuum system. The origin of this phenomenon was related to the donors generated by a high-energy species of oxygen radicals. For a deposition process, ionized oxygen may be effective but the radicals may cause plasma-enhanced oxidation with defect generation.     

Immunoelectron Microscopic Characterization of Vasopressin-Producing Neurons in the Hypothalamo-Pituitary Axis of Non-Human Primates by Use of Formaldehyde-Fixed Tissues Stored at −25 °C for Several Years

Translational research often requires the testing of experimental therapies in primates, but research in non-human primates is now stringently controlled by law around the world. Tissues fixed in formaldehyde without glutaraldehyde have been thought to be inappropriate for use in electron microscopic analysis, particularly those of the brain. Here we report the immunoelectron microscopic characterization of arginine vasopressin (AVP)-producing neurons in macaque hypothalamo-pituitary axis tissues fixed by perfusion with 4% formaldehyde and stored at −25 °C for several years (4–6 years). The size difference of dense-cored vesicles between magnocellular and parvocellular AVP neurons was detectable in their cell bodies and perivascular nerve endings located, respectively, in the posterior pituitary and median eminence. Furthermore, glutamate and the vesicular glutamate transporter 2 could be colocalized with AVP in perivascular nerve endings of both the posterior pituitary and the external layer of the median eminence, suggesting that both magnocellular and parvocellular AVP neurons are glutamatergic in primates. Both ultrastructure and immunoreactivity can therefore be sufficiently preserved in macaque brain tissues stored long-term, initially for light microscopy. Taken together, these results suggest that this methodology could be applied to the human post-mortem brain and be very useful in translational research.     

Quantitative Evaluation of Saccadic Eye Movement Disorders Under Random Visual Stimuli on CRT

A computer aided saccadic disorder examination system for clinical use is presented. Eye movements are stimulated by an M-sequence-controlled moving target on a CRT and the degree of saccadic disorder is evaluated by estimating a linear discriminant function, via procedures of cross-correlation analysis and age compensation.     

Commercialization of Micro-fabrication of Antenna-Coupled Transition Edge Sensor Bolometer Detectors for Studies of the Cosmic Microwave Background

We report on the development of commercially fabricated multichroic antenna-coupled transition edge sensor (TES) bolometer arrays for cosmic microwave background (CMB) polarimetry experiments. CMB polarimetry experiments have deployed instruments in stages. Stage II experiments deployed with O(1000) detectors and reported successful detection of B-mode (divergence-free) polarization pattern in the CMB. Stage III experiments have recently started observing with O(10,000) detectors with wider frequency coverage. A concept for a stage IV experiment, CMB-S4, is emerging to make a definitive measurement of CMB polarization from the ground with O(400,000) detectors. The orders of magnitude increase in detector count for CMB-S4 require a new approach in detector fabrication to increase fabrication throughput and reduce the cost. We report on collaborative efforts with two commercial micro-fabrication foundries to fabricate antenna-coupled TES bolometer detectors. The detector design is based on the sinuous antenna-coupled dichroic detector from the POLARBEAR-2 experiment. The TES bolometers showed the expected I–V response, and the RF performance agrees with the simulation. We will discuss the motivation, design consideration, fabrication processes, test results, and how industrial detector fabrication could be a path to fabricate hundreds of detector wafers for future CMB polarimetry experiments.     

Development of small bulge fatigue testing technique using small disk‐type specimen

A new fatigue testing technique, the small bulge fatigue (SBF) test using a small disk‐type specimen with flat and concave surfaces, was developed in this study. In the technique, a cyclic oil pressure could be alternatively applied to both specimen surfaces at the frequency of 10 Hz. After some verification tests for the displacement and strain measurements, type 316 austenitic stainless steel specimens were subjected to a preliminary test using this newly developed testing technique. As a result, the SBF test results (S‐N curve) were in good agreement with those of conventional fatigue tests by defining fatigue life as the number of cycles to the sudden drop in oil pressure because of fracture.