Electrochemical and electrochromic response of poly(thiophene-3-acetic acid) films

Thiophene-3-acetic acid has been polymerized in chloroform by a chemical method using FeCl₃ as oxidant. The films were prepared casting the solubilized polymer on ITO electrodes and studied using cyclic voltammetry, chronoamperometry and spectroelectrochemistry. During the potential sweep, an electrochromic process is observed in which the film color changes from red to black. High electrochromic efficiency was observed for more than 600 cycles, although it decreases to 73% of the initial value. Until 264 cycles, the electrochromic efficiency at 750 nm is stable and the value is 242 cm² C⁻¹.     

Isolation of bioactive compounds from Helix aspersa nerve tissue and the effect of pQPPLPRYamide on heart, esophagus and central neurons of H. aspersa and rectum of Anodonta woodiana

1. Tumour necrosis factor-alpha (TNF-alpha) is implicated in the pathogenesis of many pulmonary and airway diseases. TNF-alpha stimulation may release interleukin-8 (IL-8) in airways mediated via an increase in intracellular oxidant stress. In the present study, we have assessed leukosequestration and IL-8 release in the airways in response to intratracheal administration of human recombinant TNF-alpha, and examined the modulatory role of endogenous NO by pretreatment with a NO synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME). 2. TNF-alpha (10(2)-10(-4) u) was administered intratracheally in male guinea-pigs which were anaesthetized with urethane and were ventilated artificially. TNF-alpha induced a time- and dose-related increase in neutrophil numbers and a concomitant increase in human IL-8 equivalent level retrieved from bronchoalveolar lavage (BAL) with the peak effect at 10(3) u at 6 h of TNF-alpha injection (late phase). Intratracheal administration of recombinant human (rh)IL-8 (0.025, 0.25, 2.5 ng) producing a similar range of human IL-8 equivalent levels in BAL as measured in our results induced neutrophil recovery in BAL fluid to a similar extent. Administration of anti-IL-8 antibody prevented the late phase of neutrophil recruitment induced by TNF-alpha or rhIL-8. 3. Pretreatment with L-NAME significantly enhanced the TNF-alpha (10(3) u)-induced neutrophil recruitment and human IL-8 equivalents production at 6 h, but not at 1 h of TNF-alpha administration (early phase). L-Arginine reversed the responses to L-NAME. Pretreatment with 0.2% DMSO (i.v.) significantly inhibited TNF-alpha-induced neutrophil recruitment and human IL-8 equivalents release both in the early and late phase of the responses. Pretreatment with DMSO also inhibited the enhancement effect of L-NAME on the late phase of TNF-alpha-induced responses. DMSO failed to modify exogenous rhIL-8-induced neutrophil recruitment. Neither L-NAME nor DMSO alone induced any significant change in neutrophil numbers or human IL-8 equivalent level in BAL fluid. 4. Neutrophil depletion by cyclophosphamide pretreatment failed to modify TNF-alpha-induced human IL-8 equivalent release. 5. The expression of beta 2-integrin, CD11b/CD18 on neutrophils was increased only in the late but not early phase of TNF-alpha stimulation. L-NAME failed to modify these responses. 6. In conclusion, we demonstrated that NO may be an important endogenous inhibitor of TNF-alpha-induced leukocyte chemotaxis via inhibition of IL-8 production. Thus, the production of NO in airway inflammatory diseases may play a negative feedback role in self-limiting the magnitude of inflammatory responses.     

Studies on the mechanism of the hydrogen electrode reaction by means of deuterium tracer—I. the reaction route

The reaction route of the hydrogen electrode reaction on Ni, Rh, Au, and Pt at the reversible potential was investigated through the exchange reaction between deuterium and light water. Various reaction routes involving hydrogen adatom H(a) and adsorbed hydrogen molecule-ion H⁺₂(a) as the reaction intermediates were considered. In order to single out the correct reaction route, these routes were examined, without assuming a priori the existence of a single rate-determining step, for satisfactory interpretation of the isotopic composition of the hydrogen gas during the exchange reaction. It is concluded that the reaction route consists of two consecutive steps,

and

, where B represents H₂O or OH^?.     

Room-temperature CW operation of distributed-feedback buried-heterostructure InGaAsP/InP lasers emitting at 1.57 ?m

Room temperature CW operation of distributed-feedback buried-heterostructure InGaAsP/InP lasers emitting at 1.57 ?m was achieved. A DC threshold of about 250 mA at 25°C and a temperature coefficient of the lasing wavelength of 1.0 ?/°C were obtained. Some of these lasers manifested single longitudinal mode operation both in DC condition and in deeply modulated condition at 500 Mbit/s.     

A 16-Mbit DRAM with a relaxed sense-amplifier-pitch open-bit-linearchitecture

A 16-Mb dynamic RAM has been designed and fabricated using 0.5-μm CMOS technology with double-level metallization. It uses a novel trench-type surrounding high-capacitance cell (SCC) that measures only 3.3-μm² in cell size with a 63-fF storage capacitance. A novel relaxed sense-amplifier-pitch (RSAP) open-bit-line architecture used on the DRAM achieves a high-density memory cell array, while maintaining a large enough layout pitch for the sense amplifier. These concepts allow the small chip that measures 5.4×17.38 (93.85) mm² to be mounted in a 300-mil dual-in-line package with 65-ns RAS access time and 35-ns column address access time     

High reliability planar-type GaInAs/InP heterostructure avalanchephotodiodes

High-temperature, long-term life tests of GaInAs/InP heterostructure avalanche photodiodes have been carried out to establish criteria for high reliability photodetectors in 1.55 μm-wavelength optical submarine cable systems. A failure rate of less than 0.2 FIT at 10°C was predicted for the first time with an activation energy of 0.7 eV     

Rathke's cleft cyst

Two cases of Rathke's cleft cyst which produced symptoms of compression of the optic chiasm are described. The first case has been followed for five years since the operation. No evidence of recurrence has been noticed. The prognosis after a partial removal of the cyst wall seems to be good with this lesion. In the second case, there was clinical and laboratory evidence of hypopituitarism and the CT scan revealed suggestive findings to differentiate the cyst from a pituitary adenoma.