Microgenerator Using BiSbTe-Pt Thermopile and Pt-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Ceramic Combustor

The performance of a microcombustor thermoelectric generator device based on a thermopile using p-type Bi_0.3Sb_1.7Te₃ (BST) and n-type Pt films has been investigated. The BST films were prepared by two different methods—pulsed laser deposition (PLD) and sputter deposition—on Si₃N₄/SiO₂ multilayers on Si substrate. The ceramic catalyst combustor was patterned on the thermopile end on a thin membrane fabricated by back-side bulk etching of the silicon substrate. At 138°C the thermoelectric power factors of the PLD and sputter-deposited films were 3.6 × 10⁻³ W/mK² and 0.22 × 10⁻³ W/mK², respectively. The power from the generator with the sputter-deposited film was 0.343 μW, which was superior to that of the device with the PLD film, which provided 0.1 μW, for combustion of a 200 sccm flow of 3 v/v% hydrogen in air.     

Surgical strategy for abdominal aortic aneurysm with concurrent symptomatic malignancy

In an attempt to improve the guidelines for concurrent management of concomitant abdominal aortic aneurysm (AAA) and symptomatic malignancy, a retrospective study was undertaken. A total of 186 AAA repairs were performed electively, and 25 patients (13.4%) had concurrent symptomatic malignancy from April 1986 to March 1997. Fourteen patients underwent a one-stage operation, including five abdominoperineal rectal resections, four subtotal gastrectomies, three total gastrectomies, and two right hemicolectomies. Eleven others underwent a two-stage operation, including four with total gastrectomy and left hemicolectomy followed by AAA repair, as well as two with right hemicolectomy and one with left hemicolectomy prior to AAA repair. There were no operative deaths or severe postoperative complications. Of the 25 patients, 22 (88.0%) are still alive during follow-up ranging from 8 months to 11 years. Our surgical approach to both lesions is as follows: (1) Using the transperitoneal approach alone, subtotal gastrectomy and abdominoperineal rectal resection can be safely done simultaneously. (2) Although total gastrectomy can also be performed concurrently, the approach used for each lesion is separate. (3) Colorectal resection is generally done separately. However, a one-stage operation can be performed using the thromboexclusion procedure for AAA repair in patients with right-sided colonic cancer or a temporary transverse colostomy for left-sided colorectal cancer.     

A 557-mW, 2.5-Gbit/s SONET/SDH regenerator-section terminating LSIchip using low-power bipolar-LSI design

A regenerator-section terminating digital large-scale-integration chip for an STM-16 (2.5-Gbit/s synchronous optical network/synchronous digital hierarchy) regenerator has been developed using low-power bipolar technologies. The high-speed performance of bipolar devices enabled four or more chips, including a demultiplexer and a multiplexer, to be integrated into a single chip. The low-power dissipation of 557 mW, only about one-tenth that of previously reported chips, was achieved through the use of four design steps: one-chip integration architecture, power management, 2.5-V emitter-coupled logic, and power optimization     

An optical field-induced ionization X-ray laser using a preformedplasma scheme

Soft X-ray amplification by optical field-induced ionization (OFI) of a preformed plasma is investigated. A small-signal gain of 20 cm^-1 and a gain-length product of 4 at 13.5 nm on the Lyman-α transition in hydrogen-like lithium have been obtained using the modified OFI scheme. Experimental and numerical results ensure that we have produced a plasma with a significantly lower electron temperature than what is expected by an above-threshold ionization model. To explain the results, a two component plasma model in which relatively high temperature electrons are produced by OFI in a cold electron bath of the preformed plasma is presented. The model indicates that the average electron temperature of the OFI plasma rapidly decreases since a high-temperature part of the electrons escapes from the focal volume without interaction. The initial electrons produced prior to the field ionization, which survive after the OEI, also significantly contribute to the rapid three-body recombination. Based on the ionization-induced refractive index change, the pulse propagation of a high-intensity pump laser during the OFI is also discussed     

Cardiac malignant pheochromocytoma with bone metastases

A patient with malignant cardiac pheochromocytoma with bone metastases is described. The primary tumor was located between the pulmonary trunk and the left atrium, while metastatic lesions were found in the iliac bones. Treatments with antihypertensive agents, alpha-methylparatyrosine, and combination chemotherapy with cyclophosphamide, vincristine, and dacarbazine partially improved the patient's symptoms, catecholamine levels, and the metastatic lesion of the iliac bones. However, the primary tumor in the heart progressively increased in size and the patient died of disseminated intravascular coagulation and other various complications about 4 years after the diagnosis of the disease.     

Self-routing space switch network comprising fast and uniform switch elements

The authors present a method by which to construct a fast N*N self-routing space switch network with identical 2*2 switch elements. This network is nonblocking and employs O(N log/sup 3/ N) switch elements; each element uses just two bits of the output port address for switching control.<>     

Surface modification of III-V compound semiconductors using surfaceelectromagnetic wave etching induced by ultraviolet lasers

The surface modification of semiconductors by laser-induced surface electromagnetic wave (SEW) etching was investigated. With the novel etching method using a holographic exposure system, submicron periodic dot structures were fabricated directly on semiconductor substrates (n-InP, n-GaAs, and InGaAs-InP). Making use of laser polarization dependence in this etching system, a variety of surface modifications could be achieved on the semiconductors. In particular, in the case of using the s-polarization light, periodic submicron dot structures with a geometrical diameter down to 80 nm could be obtained directly using a single-step process without a mask. The InGaAs-InP dot structures were studied optically by means of photoluminescence spectroscopy, and the blue shift of the photoluminescence energy up to 5.36 meV was observed for the smallest dots, which displayed a lateral quantization     

Potent thyrotropic activity of human chorionic gonadotropin variants in terms of 125I incorporation and de novo synthesized thyroid hormone release in human thyroid follicles

Using a highly sensitive bioassay for TSH, in which human thyroid follicles incorporate 125I and release de novo synthesized thyroid hormone into the culture medium, the thyrotropic activities of various hCG preparations were studied. Under the culture conditions employed, bovine TSH (bTSH) was approximately 6- to 9-fold more active than human TSH (hTSH). Highly purified hCG prepared from urine of normal pregnant women (CR 127) had only a trivial thyrotropic activity equipotent to 0.00022 microU bTSH/U hCG or 0.0013 microU hTSH/U hCG (19.7 microU hTSH/mg hCG). Hybrid hCG (AB1ER) also elicited low thyrotropic activity (14.0 microU hTSH/mg), whereas crude hCG had moderate thyrotropic activity (0.041 hTSH microU/U hCG or 127 microU/mg protein). Deglycosylated hCG, a very weak LH/hCG receptor agonist, was the most potent agonist in thyroid follicles (588 microU hTSH/mg protein). hCGs purified from urine of patients with trophoblastic tumors had greater TSH-like activity (37-84 microU hTSH/mg protein) than purified hCG. Asialo-hCG purified from a patient with choriocarcinoma had very potent TSH-like activity (468 microU hTSH/mg). Submaximal doses of bTSH and hCG variants produced additive stimulation of thyroid function. Furthermore, the thyrotropic effect of hCG was inhibited by anti-TSH receptor antibody obtained from patients with myxedema. These in vitro findings suggest that although hCG is reported to exert potent cAMP-stimulating activity on rat thyroid-like cells (FRTL-5) and Chinese hamster ovary cells transfected with hTSH receptor complementary DNA (0.092-0.72 microU hTSH/U hCG), the thyrotropic activity induced by authentic hCG in human thyroid follicles is too weak to cause hyperthyroidism in normal pregnancy. However, hCG produced by some trophoblastic tumors, particularly asialo-hCG, has potent thyrotropic activity sufficient to cause clinically overt hyperthyroidism when produced excessively.     

The effects of ginseng radix rubra on human vascular endothelial cells

The effect of Ginseng Radix Rubra (Red ginseng) on human vascular endothelial cells was examined. Red ginseng was found to promote the proliferation of vascular endothelial cells, inhibit the production but promote the decomposition of endothelin, which is known to constrict blood vessels and raise blood pressure as well as accelerated the synthesis of nitric oxide, which is known to have an angio-tonic effect. Furthermore, Red ginseng was observed to increase the production of Interleukin 1 beta, which is known to play important roles in the homeostatic activities of the human body such as immunity and inflammation as well as increasing the production of tissue plasminogen activators, which suppress the formation of thrombin in the blood coagulation and fibrinolysis mechanisms. It is suggested that Red ginseng has the effect of accelerating endothelial cells proliferation and of promoting physiological activities.     

A T‐LCLC type immittance converter

“Immittance converter” is short for “impedance–admittance converter.” The immittance converter has an input impedance that is proportional to the admittance of the load connected across output terminals. In this converter, the output current is proportional to the input voltage and the input current is proportional to the output voltage. Consequently, it converts a constant voltage source into a constant current source and a constant current source into a constant voltage source. It is well known that the quarter‐wavelength transmission line shows immittance conversion characteristics. However, it has very long line length for the switching frequency, and is not suitable for power electronics application. Thus, we proposed immittance converters that consist of lumped elements L, C and show improved immittance conversion characteristics at a resonant frequency. In this paper, we propose a T‐LCLC‐type immittance converter, which has the transitive configuration and both advantages of T‐LCL‐ and π‐CLC‐type immittance converters. We show voltage–current transformation characteristics and frequency characteristics and efficiency characteristics of the T‐LCLC immittance converter. These characteristics were determined analytically and experimentally. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(3): 57–63, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10095