Passive Millimeter-Wave Microscopy

A new type of millimeter-wave imaging technique, passive millimeter-wave microscopy is proposed and demonstrated. Passive millimeter-wave imaging techniques when combined with scanning near-field microscopy enable direct observation of millimeter-wave signals thermally emitted from the viewed object with a spatial resolution below the diffraction limit. Details of our passive microscope system operating at Ka-band frequencies are explained. Millimeter-wave images obtained with the system are presented to demonstrate the feasibility of this new imaging technique.     

Direct modulation characteristics of GaInAsP/InP d.h. lasers with various stripe widths measured by sharp-pulse method

The direct modulation characteristics of GaInAsP/InP d.h. lasers emitting at 1.3 ?m with various stripe widths were measured by the proposed sharp-pulse method. As a result, a flat modulation frequency response up to 1.9 GHz was observed in a laser diode with 5 ?m stripe width.     

Far-infrared laser oscillations from H2CO

Lasting laser oscillation was obtained from H2CO vapor with a longitudinal-flow tube. Ten lasing lines, including six new lines, have been observed in the pressure range of 0.18-0.35 torr. The optimum conditions were 2.5-7.1 kV and 2.5 Hz for excitation voltage and pulse repetition rate, respectively. The pulse shape of the lines was observed by an Ni-W diode.     

Solid and thermal properties of ABA‐type triblock copolymers designed using difunctional fluorine‐containing polyimide macroinitiators with methyl methacrylate

BACKGROUND: ABA‐type poly(methyl methacrylate) (PMMA) and fluorine‐containing polyimide triblock copolymers are potentially beneficial for electric materials. In the work reported here, triblock copolymers with various block lengths were prepared from fluorine‐containing difunctional polyimide macroinitiators and methyl methacrylate monomer through atom‐transfer radical polymerization. The effects of structure on their solid and thermal properties were studied. RESULTS: The weight ratios of the triblock copolymers derived using thermogravimetric analysis were shown to be almost identical to the ratios determined using ¹H NMR. The solid properties (film density and maximum d‐spacing value) and thermal properties (glass transition and thermal expansion) were shown to be strongly dependent on the weight ratios of both PMMA and polyimide components. Furthermore, a porous film, which showed a lower dielectric constant of 2.48 at 1 MHz, could be prepared by heating a triblock copolymer film to induce the thermal degradation of the PMMA component. CONCLUSION: The use of the polyimide macroinitiator was useful in the preparation of ABA‐type triblock copolymers to control each block length that influences the solid and thermal properties. Additionally, the triblock copolymers have great potential in preparing porous polyimides in the application of electric materials as interlayer insulation membranes of large‐scale integration. Copyright © 2009 Society of Chemical Industry     

Effect of fasting subjects'' posture on 13C-urea breath test for detection of Helicobacter pylori infection

HIV-associated salivary gland disease (HIV-SGD) includes lymphoepithelial lesions and cysts involving the salivary gland tissue and/or intraglandular lymph nodes, and Sj?gren-like conditions. Three cases of salivary gland disease occurring in HIV-infected patients are reported. Histopathological examination showed squamous epithelium-lined cysts. In the walls of the cysts lymphoid tissue, epitheloid granulomas and giant cells were found. The clinical and histopathological criteria as well as magnetic resonance imaging and therapy are discussed.     

A case of lumbosacral lipoma-associated adult onset tethered cord syndrome with initial symptoms of sensory disturbance and intractable foot ulcers]

A 63-year-woman who complained of sensorimotor disturbance of the lower extremities and urinary disturbance was presented. She noted loss of superficial sensation in both feet and foot ulcers at the age of 20 years. Her illness was initially diagnosed as hereditary sensory neuropathy type 1 (HSN1). The foot ulcers were so intractable that she had to have her right leg amputated at the age of 48 years. She had a severely impaired superficial sensation in the lower extremities and buttock, distal weakness of the left leg, and dysuria at the age of 60 years. The neurological examination revealed that she had segmental sensorimotor disturbance below the levels of the 5th lumbar segment. MRI demonstrated tethered cord with a lumbosacral lipoma. Adult onset tethered cord syndrome (TCS) that presents with HSN 1-like symptoms as initial clinical features has not yet been reported. Foot ulcers are often seen in child onset TCS in which the degree of tethered cord is severer than adult onset cases. It is reported that release of the tethered cord promotes healing of the foot ulcers. We recommend MRI for the study of the lumbosacral cord of patients with HSN 1-like symptoms, because there is a possibility that such patients may have TCS and early surgical treatment is effective for TCS.     

0.1-μm gate-length superconducting FET

A superconducting field-effect transistors (FET) with a 0.1-μm-length gate electrode was fabricated and tested at liquid-helium temperature. Two superconducting electrodes (source and drain) were formed on the same Si substrate surface with an oxide-insulated gate electrode by a self-aligned fabrication process. Superconducting current flowing through the semiconductor (Si) between the two superconducting electrodes (Nb) was controlled by a gate-bias voltage     

A dual-parameter multichannel analyzer by a dual-computer system

The design and feasibility of a simple and practical system for measuring two-parameter signals is reported. A dual-parameter multichannel pulse-height analyzer (MCA) which uses two central processing units (CPUs) is developed and designed. One computer (master computer) controls the other computer (slave computer), and also displays, records, and analyzes the data. The slave computer controls two analog-to-digital converters (ADCs), collects the dual-parameter data, and transfers the collected data to the master computer. Three methods of data transfer between the two CPUs are examined and discussed. The count capacity at the data collection by the slave computer is 2¹⁶-1/ch (2-B-long data), and this is expanded to 2³²-a/ch (4-B-long data) at the master computer. The data are analyzed and at any time stored in the storage apparatus by the dual CPU system. The system demonstrates stable operation over long measurement periods     

Idiopathic restrictive cardiomyopathy with diffuse perimyocytic fibrosis--a rare observation

Idiopathic restrictive cardiomyopathy (RCM) is rare. Even today little is understood of its etiology or underlying mechanisms, and definitive diagnostic criteria are lacking. In this report, we describe a case of idiopathic RCM in a young Japanese woman who died while awaiting cardiac transplantation during the 5-year course of the disease. Rare pathologic findings of diffuse perimyocytic fibrosis were revealed at autopsy.