Comparison of the evaluation of the carbon content in solid solution in extra-mild steels by thermoelectric power and by internal friction

The comparison of the evaluation of the carbon content in solid solution in extra-mild steels by thermoelectric power (TEP) and by internal friction (IF) showed the existence of a population of carbon atoms, which is not detected by IF but is visible by TEP. This population, which contributes to the strain ageing, could be constituted of carbon atoms in interaction with substitutional atoms.     

Investigation of the electronic structure of the new quaternary hydride PdSr2LiH5

We have investigated the band structure of the new tetragonal quaternary mixed alkali-alkaline earth transition metal hydride PdSr₂LiH₅ by means of the ab initio augmented plane wave method. We find this material to be metallic. The total density of states as well as its partial wave analysis have been used to investigate the origin of the electronic states. In this hydride, like in superconducting PdH, the palladium d bands are essentially filled and the H-s states have a non-negligible contribution at the Fermi energy. We find the electronic contribution to the electron-optical phonon coupling constant to be sizeable, although smaller than in PdH.     

Langerhans cells in Langerhans cell granulomatosis are not actively proliferating cells

Pulmonary Langerhans cell granulomatosis (LCG), also called histiocytosis X, is a disorder of unknown etiology characterized by the presence of destructive granulomas containing numerous Langerhans cells (LCs). The process may be localized or multifocal, and it remains unclear whether the same pathogenic mechanism is involved in all forms of the disease. It is often assumed that the massive accumulation of LCs at the sites of the lesions results from the abnormal proliferation of these cells, although it has been suggested that LCG in adults, at least in the lung, could be a reactive disorder initiated by activated LCs. Little is known, however, concerning the mechanisms responsible for the accumulation of large numbers of LCs in the course of the disease, and the relative contribution of recruitment and local proliferation of these cells remains to be established. To investigate this question, the proportion of replicating LCs was evaluated in biopsied granulomas from patients with localized or diffuse form of LCG by means of several histopathological techniques currently used in assessment of cell proliferation. The findings demonstrate that, except for proliferating cell nuclear antigen (PCNA), all parameters measured are low in all forms of the disease. They are similar to those of renewing epithelial cells and clearly less than those of neoplastic cells. These data strongly suggest that LCs in LCG granulomas are not a rapidly dividing cell population and that local LC replication makes only a minimal contribution to granuloma maintenance. Caution appears to be necessary in the use of PCNA as a marker of growth fraction.     

Functional characteristics of pyruvate transport in Phycomyces blakesleeanus

A saturable and accumulative transport system for pyruvate has been detected in Phycomyces blakesleeanus NRRL 1555(-) mycelium. It was strongly inhibited by alpha-cyano-4-hydroxycinnamate. l-Lactate and acetate were competitive inhibitors of pyruvate transport. The initial pyruvate uptake velocity and accumulation ratio was dependent on the external pH. The Vmax of transport greatly decreased with increasing pH, whereas the affinity of the carrier for pyruvate was not affected. The pyruvate transport system mediated its homologous exchange, which was essentially pH independent, and efflux, which increased with increasing external pH. The uptake of pyruvate was energy dependent and was strongly inhibited by inhibitors of oxidative phosphorylation and of the formation of proton gradients. Glucose counteracted the inhibitory effect of the pyruvate transport produced by inhibitors of mitochondrial ATP synthesis. Our results are consistent with a pyruvate/proton cotransport in P. blakesleeanus probably driven by an electrochemical gradient of H+ generated by a plasma membrane H+-ATPase.     

Subband decomposition strategies for object‐based image coding

In order to attain perfect reconstruction, subband decomposition of arbitrarily shaped objects requires special strategies to deal with the decimation problem. One of the two strategies described in this paper (scheme 1) inserts pixels with amplitudes equal to the mean values of the neighboring ones belonging to the object. The requirement of transmitting (coding) these pixels reduces the coding gain and is avoided by the second strategy (scheme 2) examined in this paper. This strategy determines specific values of the pixels added to the object in such a way that they result in predefined amplitudes after decimation. For this reason, this method outperforms scheme 1. PSNR versus bit rate are presented for two objects. © 2003 Wiley Periodicals, Inc. Int J Imaging Syst Technol 13, 179–187, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.10054     

“Key” sectors in final energy consumption: an input–output application to the Spanish case

In this paper we analyze the determination of “key” sectors in the final energy consumption. We approach this issue from an input–output perspective and we design a methodology based on the elasticities of the demands of final energy consumption. As an exercise, we apply the proposed methodology to the Spanish economy. The analysis allows us to indicate the greater or lesser relevance of the different sectors in the consumption of final energy, pointing out which sectors deserve greater attention in the Spanish case and showing the implications for energy policy.     

Testing an isolated system powered by solar energy and PEM fuel cell with hydrogen generation

Photovoltaic systems are widely used to power telecommunications systems in remote locations, but this is restricted by the irregular availability of solar energy. A European collaboration is developing and testing an autonomous system that combines a photovoltaic power system in combination with an electrolyzer that uses surplus power to produce hydrogen, which can be used in a PEM fuel cell when there is insufficient solar energy.     

Serum ferritin as a component of the insulin resistance syndrome

Six human cancer cell lines exhibiting a large range of sensitivity to 5-fluorouracil (5-FU) were evaluated for thymidylate synthase (TS) and p53 gene expression, TS and dihydropyrimidine dehydrogenase (DPD) activity, as well as cell cycle parameters, S-phase fraction (SPF), bromodeoxyuridine labelling index (LI) and S-phase duration (SPD). All these parameters were investigated for 7 days in asynchronously growing cell populations and compared with the cell sensitivity to 5-FU. No significant correlation was found between S-phase parameters and TS gene expression and/or activity. TS activity was higher in proliferating cells; however, it was not significantly higher in rapidly growing cell lines with short SPD. Neither TS gene expression nor activity was found to correlate with 5-FU sensitivity. On the another hand, a statistically significant correlation (P < 0.0001) was observed between LI and SPD and 5-FU sensitivity. The present results suggest that cell cycle parameters such as SPD and/or LI could be better parameters for 5-FU sensitivity prediction than TS gene expression and/or activity. This could be especially informative in cases of concomitant radio-chemotherapy as S-phase parameters are already proposed for hyperfractionated radiotherapy planning.     

Optical sensing of cyanide using hybrid biomolecular films

The selective sensing of cyanide anions in water has been studied using a hybrid biomaterial composed of a mesoporous TiO₂ film of crystalline nanoparticles and the protein hemoglobin. The mesoporous structure of the film prevents protein unfolding and also stabilizes the oxidized form of the prosthetic groups. Low-levels of cyanide anions (<0.2 ppm (0.2 mgr/L)) can be detected by monitoring the changes in the optical properties of the hybrid biomolecular films upon cyanide binding to the heme groups.