The Direct Spectroscopy of Positronium Hyperfine Structure Using a Sub-THz Gyrotron

Positronium is an ideal system for research on Quantum Electrodynamics (QED), especially in a bound state. A discrepancy of 3.9 standard deviations has been found between the measured hyperfine structure (Ps-HFS) and the QED predictions. This may be due to the contribution of unknown new physics or common systematic effects in previous measurements, in all of which the Zeeman effect was used. We propose a new method to directly measure the Ps-HFS using a high power gyrotron. We compare two resonators which have been developed to supply sufficient power to drive the direct transition, a Fabry-Pérot resonator and a ring resonator with a diffraction grating. We plan to perform first direct measurement of Ps-HFS within the next six months.     

Long-term pharmacological kindling increases in vitro release of IR-Met and IR-Leu-enkephalin from amygdala

Preoperative therapy with octreotide, a long-acting somatostatin analog, suppresses GH hypersecretion, shrinks GH-producing tumors and leads to an improvement in subsequent surgical remission in acromegalic patients. A continuous infusion of octreotide has demonstrated more persistent suppression of GH secretion than intermittent injections, and only a few studies were reported on the effect of the tumor shrinkage with a continuous infusion of a small dose of octreotide. We therefore investigated the preoperative effects of small doses of octreotide (120-240 micrograms/day) administered continuously (with a subcutaneous infusion pump) over a short period (2 or 4 weeks) in nine untreated acromegalic patients. Octreotide therapy resulted in suppression of serum GH and IGF-1 concentrations in 8 out of 9 patients and reduction in pituitary tumor size measured by MRI in all patients (by 7.9 to 38.5%). In particular, considerable reduction in tumor size (more than 20%) occurred in 6 of 9 patients. In three patients assessed serially throughout the preoperative period, reduction in tumor size was noted within only one week after the start of octreotide therapy and reduction rate more than 20% was obtained within the first two weeks. In one patient, suprasellar tumor expansion totally disappeared after such therapy. Our results indicate that short-term continuous subcutaneous infusion of a small dose of octreotide results in not only inhibition of GH hypersecretion but also shrinkage of tumor size prior to surgery.     

High microwave and ultra-low noise performance of fullyion-implanted GaAs MESFETs with Au/WSiN T-shaped gate

Fully ion-implanted n⁺ self-aligned GaAs MESFETs with high microwave and ultra-low-noise performance have been fabricated. T-shaped gate structures composed of Au/WSiN are employed to reduce gate resistance effectively. A very thin and high-quality channel with high carrier concentration can be formed by adopting the optimum annealing temperature for the channel, and the channel surface suffers almost no damage by using ECR plasma RIE for gate formation. GaAs MESFETs with a gate length as short as 0.35 μm demonstrated a maximum oscillation frequency of 76 GHz. At an operating frequency of 18 GHz, a minimum noise figure of 0.81 dB with an associated gain of 7.7 dB is obtained. A K_f factor of 1.4 estimated by Fukui's noise figure equation, which is comparable to those of AlGaAs/GaAs HEMTs with the same geometry, reveals that the quality of the channel is very high     

Superlong-range interactions of colloids

Colloid particles have superlong-range attractive and repulsive forces. The distance between the secondary minimum of the potential energy of the interaction and the surface of the colloid is of the order of several μm and several tens of μm. These interactions clearly appear in the distribution of order-solution phase coexistence, in gathering particles to the ordered phase and in spontaneous pair formation. A new ‘Dynamic electrical multipole model and resonance effect’ is given. From this model, it is predicted that pairs will form in a shear field even in highly concentrated salt solution. Pair formation was observed after 24 hours as predicted.     

Induction of alloantigen-specific T cell tolerance through the treatment of human T lymphocytes with wortmannin

Signaling through the CD28 molecule on T cells by its natural ligand, B7, on APCs has recently been shown to require the presence of an active phosphatidylinositol 3-kinase pathway to mediate some of its costimulatory activities (1-7). Using the phosphatidylinositol 3-kinase inhibitor, wortmannin (WN) (8), on human and murine T cells, we have inhibited B7-1-mediated T cell activation and induced Ag-specific tolerance. The addition of WN and/or the B7-1 antagonist, CTLA4Ig, to primary human T cell cultures stimulated with B7-1-transfected allogeneic melanoma cell lines inhibited the generation of alloantigen-specific proliferative and cytolytic responses in vitro. Subsequent examination of these WN- and CTLA4Ig-treated primary T cell cultures revealed that these lymphocyte populations were tolerized to rechallenge with the priming alloantigens in secondary cultures in the absence of additional inhibitor(s). However, reactivity to a third party allogeneic stimulator remained intact. This WN-induced tolerance was reversed by the addition of high dose IL-2, but not IL-4 or IL-7, to the primary cultures, indicating that T cell anergy, not deletion, was responsible for this phenomenon. In vivo studies using a murine graft-vs-host disease (GVHD) model demonstrated that WN treatment of allogeneic donor lymphocytes in vitro failed to generate a significant GVHD in irradiated mouse recipients compared with control allogeneic donor lymphocytes. These findings suggest potentially novel therapeutic strategies for the prevention of GVHD.     

Nedaplatin and 5-FU combined with radiation in the treatment for esophageal cancer

A direct differentiation of the internal and external drug-deposition pattern into hair was made using two fluorescent dyes and fluorescence microscopy after systemic administration to mice or external exposure of untreated hair. Mice (23 days old, C57 and Balb/C) were administered either rhodamine or fluorescein intraperitoneally at varied doses on 3 consecutive days of 3 weeks, and hair was sampled 1 week later. Another group was given 10 mg/kg rhodamine or 100 mg/kg fluorescein and sampled at time points from 5 min to 168 hr. The time courses of external deposition of rhodamine and fluorescein into untreated hair were examined after hair was soaked in 0.1 mg/ml solutions at pH 3, pH 6, and pH 9 aqueous buffer or methanol. The hair was then extracted in pH 6 phosphate buffer or methanol for 24 hr. In vivo accumulation was distinguishable as fluorescent bands along the length of the hair for rhodamine and fluorescein. The pattern of in vivo deposition appears to arise from the rapid accumulation within the cortex and medulla, with little deposition evident in the cuticle. Neither phosphate buffer nor methanol washes affected the intensity of fluorescence in the hair. External loading of rhodamine into the hair resulted in staining of the junctions of cuticle scales. This pattern persisted even after 12 hr of solution exposure. Extraction with pH 6 phosphate buffer or methanol did not remove rhodamine. Fluoroscein followed a similar pattern, with maximum fluorescence when hair was loaded in pH 6 100mM phosphate buffer and nominal staining when loaded in pH 9 100 mM Tris buffer or methanol. Soaking the hair in pH 6 buffer, but not methanol, removed some fluorescein. These results demonstrate that compounds in the circulation can rapidly diffuse into the forming cortex and medulla, where rapid associations occur with elongating intermediate filaments specific to the medulla and cortex. These compounds can become significantly occluded within the mature matrix and are resistant to removal in aqueous or methanolic solutions.     

Molecular dynamics of the generation process of double‐walled carbon nanotubes from peapods

The generation process of a double‐walled carbon nanotube (DWNT) from a “peapod” was studied by classical molecular dynamics simulation. Starting from a peapod structure, defined by five C₆₀ molecules inside a (10,10) single‐walled carbon nanotube (SWNT), polymerized fullerenes, a peanut‐like structure and an almost nanotube‐like structure were obtained under suitable conditions of temperature control. The mean distance between the two layers of the DWNT agreed with an experimental report that it is larger than the interlayer spacing found in multi‐walled carbon nanotubes (MWNTs). In addition, the chirality dependence of the potential energy of a DWNT on the relative chirality of its constituent tubes was examined using a 6‐12 Lennard‐Jones potential. It was found that the potential energy depends only on the distance between the two layers, not on the relative chiralities. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(4): 254–264, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20115     

Fully digital LCoS device for consumer applications

Abstract— This paper presents a new display device, which combines a digital backplane and a vertically aligned nematic liquid‐crystal layer. The device has 1280 × 720 pixels in a 0.7‐in.‐diagonal display area. In this paper, we present the concept of the new device and overview the performance of the device for a rear‐projection television application.     

Prospect and status of MITI''s quantum functional device project

The Quantum Functional Device (QFD) project started in fiscal year (FY) 1991 as a ten-year project. The mission of this QFDs project is to develop novel devices for information processing which control quantum phenomena to realize low power consumption, and high-speed and multi-functional operation. The participants in this project are the Electrotechnical Laboratory, five universities, and eight private companies, including two US and UK companies.     

Association between dopamine D4 receptor (D4DR) exon III polymorphism and novelty seeking in Japanese subjects

Only five cases of paraganglioma of the prostate have been reported hitherto. The tumours may be functional (phaeochromocytomas) or non-functional and benign or malignant. We present a sixth case--a non-functional, benign paraganglioma of the prostate--with a review of the literature.