990 resultados para Controlled company


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Distyryl benzene derivatives (DSB-1 and DSB-2) were deposited on a KBr (001) surface. DSB-1 molecules took two kinds of orientations depending on the substrate temperature. On the other hand, DSB-2 grew epitaxially. The longitudinal axes of DSB-2 molecules were oriented parallel to the substrate surface.

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In this paper, the polypyrrole (PPy) film modified electrodes are used as an electroreleasing reservoir. The electrochemically controlled release of 5-fluorouracil (5-FU) from a PPy film modified electrode to aqueous electrolytes is studied by the in situ probe beam deflection (PBD) method combined with cyclic voltammetry (CV) and chronoamperometry (CA). The PBD results reveal that the release of 5-FU from PPy film depends on the electrochemical redox process of the PPy film electrode. The released amount is controlled by the reduction potential and is proportional to the thickness of the film. The exchange of 5-FU anions with Cl- on an open circuit is slow on the time scale of minutes, but the release of 5-FU anions can proceed quickly at -0.6 V (vs Ag/AgCl). The amount of released 5-FU decreases with the time that the PPy film is soaked in aqueous solution. (C) 1998 Elsevier Science Ltd. All rights reserved.

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Copper phthalocyanine doped polymethacrylate Langmuir-Blodgett films were transferred to align a nematic liquid crystal 5CB, It is found that the pre-tilt angle of the liquid crystal can be controlled with the variation of the doped copper phthalocyanine molecular ratio and is correlated with the dichroic ratio of the aligning layer. The polarity of the aligning layer is regarded as the most likely underlying factor that causes the different LC alignment configurations. (C) 1997 Elsevier Science B.V.

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Polypyrrole (PPy) film was synthesized by anodic polymerization of pyrrole onto the surface of platinum electrode in the solution of sodium p-toluene sulfonate (NaTsO). When this film was oxidized anodically in an aqueous solution of adenosine triphosphatle (ATP), the ATP anions were incorporated into the film. Release of ATP From the film could be accomplished by reduction of the film in aqueous electrolyte solution. The total amount of ATP released from the film was determined by UV spectroscopic method.

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We have presented two simple methods of ''unfixed-position shield'' and ''pulling out'' for making sharp STM Pt-Ir tips with low aspect ratio by electrochemical etching in KCN/NaOH aqueous solution and ECSTM tips coated with paraffin. By limiting the elec

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Polypyrrole (PPy) film is synthesized by anodic polymerization of pyrrole onto the surface of a platinum electrode in the presence of toluene-p-sulfonate and the film is used for the controlled release of the neurotransmitter, adenosine 5'-triphosphate (ATP).

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A homologue of the lower vertebrates translationally controlled tumor protein (TCTP) was cloned from the marine fish Japanese sea perch (Lateolabrax japonicus) by the technology of homology cloning. The full-length cDNA sequence of the sea perch TCTP gene contained a 5' untranslated region (UTR) of 47 bp, a 3' UTR of 433 bp, and a putative open reading frame (ORF) of 510 bp encoding a polypeptide of 170 amino acids. The deduced amino acid sequence of the sea perch TCTP gene showed a high similarity to that of zebrafish, rohu, rabbit, chicken and human. Sequence analysis revealed there were a signature sequence of TCTP family, an N-glycosylation site, and five Casein kinase phosphorylation sites in the sea perch TCTP. The temporal expression of TCTP genes in healthy and lipopolysaccharide (LPS) challenged fishes was measured by semi-quantitative reverse transcription-PCR (RT-PCR). The results indicated that LPS could up-regulate the expression of sea perch TCTP in the examined tissues, including head-kidney, spleen and liver.

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Commercial cultivation of the dioecious brown macroalga Hizikia fusiformis (Harvey) Okamura in East Asia depends on the supply of young seedlings from regenerated holdfasts or from wild population. Recent development of synchronized release of male and female gametes in tumble culture provides a possibility of mass production of young seedlings via sexual reproduction. In this paper, we demonstrate that controlled fertilization can be efficiently realized in ambient light and temperature in a specially designed raceway tank in which the sperm-containing water has been recirculated. The effective fertilization time of eggs by sperm was found to be within six hours. Fast growth and development of the young seedlings relied on the presence of water currents. Velocity tests demonstrated that young seedlings of 2-3 mm in length could withstand a water current of 190 cm s(-1) stop without detachment. Culture experiments at 24 h postfertilization showed that elongation of both the seedlings and their rhizoids were not hampered by high irradiance up to 600 mu mol photons m(-2) stop s(-1) stop. However, growth was slightly retarded if cultured at a temperature of 16 degrees C compared to other culture temperatures of 22, 25 and 29 degrees C. No seedling detachment was observed after transfer of the young seedlings to raft cultivation in the sea after one and 1.5 months post-fertilization, indicating the feasibility of obtaining large quantity of seedlings in such a system.

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Laboratory experiments were conducted to determine the effects of sand substratum, light, starvation, fish density and size variation on cannibalism among Japanese flounder juveniles, Paralichthys olivaceus. Cannibalistic behavior (biting and swallowing) increased significantly with starvation except in darkness, where juveniles could not find and attack their prey. Cannibalism occurred more frequently in heterogeneous than in the homogeneous size groups. Cannibalism was more frequent in light than in darkness at each starvation level. With sufficient food present, sand had no significant effect on cannibalism among homogeneous size juveniles, but played an important role in discouraging predation among members of the heterogeneous size groups. With sufficient food present, the rate of cannibalism was generally low and there were no significant differences in cannibalism among fish density levels of the homogeneous juveniles, With starvation, the cannibalism rate was significantly higher in high density groups than in the lower ones. Our results indicate that size variation, starvation and Light are the major factors affecting cannibalism in flounder juveniles, while sand and fish density only have a limited effect on cannibalism, depending on the nature of other factors. (C) 2000 Elsevier Science B.V. All rights reserved.