Search

X-ray diffraction, Raman scattering and dielectric susceptibility experiments have been performed on PLZT 9/65/35 as a function of temperature. The correlation function of the polarization is shown to increase when the temperature is decreased from 800 K, but the system freezes before achieving a long range ferroelectric order.

HIV-1 gp120/gp160 is known to disturb the activity of p56 lck, protein kinase C (PKC) and Ca 2+homeostasis in T lymphocytes. We found that gp160 decreases the Kv1.3 current of Jurkat E6.1 cells probably by increasing the PKC-dependent phosphorylation of Kv channel protein after 5 days. This decrease is dose-dependent. In contrast, gp160 did not decrease the Kv1.3 current of the JCaM1.6 cell line, a p56 lck-defective Jurkat cell line. This shows that p56 lckwas at the beginning of the events which induced the Kv1.3 current decrease. As a consequence of this decrease, Jurkat E6.1 cells were depolarized and exhibited a volume increase.

The γ origin of plasmid R6K requires the specific initiator protein π for initiation of replication. However, increased π concentrations inhibit replication. The host-encoded integration host factor (IHF) protein permits γ origin replication at otherwise inhibitory π levels. IHF is thought to mediate this positive effect by directly binding to the γ origin. In this study we demonstrate that IHF binding to one IHF site in the γ origin,ihf1, but not to the other side,ihf2, is necessary for the γ origin to replicate at high π protein levels. We also show thatin vitroreplication of the γ origin plasmid requires IHF binding to theihf1 site. Finally, we demonstrate bothin vivoandin vitrothat, when mutant π proteins (hyperactive) are provided instead of wild-type π, γ origin plasmids can replicate in the absence of IHF. This supports a previously proposed hypothesis that the π mutants can bypass the IHF requirement for γ origin replication.

The impact of heavy metals (Cd, Cu, Zn) on microbiological respiration and ATP biomass of mixtures of compost (sludge+sawdust) and mineral substrates (arenites of sandstone or granite) was studied by aerobic in vitro incubation for 21 days.The compost was enriched with trace metals, corresponding to final contents of 15, 1500 and 3500 ppm for Cd, Cu and Zn, respectively, in the mixture. CO2 measurements were used to follow the global biological activity during the incubation period. Biomass was evaluated by ATP measurements before and after the experiment. Organo-mineral interactions were characterized by a granulometric fractionation and by chemical extractions.The stronger toxicity of heavy metals observed with granite as compared to sandstone is interpreted by more efficient organo-mineral interactions with the latter.

The human protein p78 is induced and accumulated in cells treated with type I interferon or with some viruses. It is the human homolog of the mouse Mx protein involved in resistance to influenza virus. A full-length cDNA clone encoding the human p78 protein was cloned and sequenced. It contained an open reading frame of 662 amino acids, corresponding to a polypeptide with a predicted molecular weight of 75,500, in good agreement with the Mr of 78,000 determined on sodium dodecyl sulfate gels for the purified natural p78 protein. The cloned gene was expressed in vitro and corresponded in size, pI, antigenic determinant(s), and NH2 terminus sequence to the natural p78 protein. A second cDNA was cloned which encoded a 633-amino-acid protein sharing 63% homology with human p78. This p78-related protein was translated in reticulocyte lysates where it shared an antigenic determinant(s) with p78. A putative 5' regulatory region of 83 base pairs contained within the gene promoter region upstream of the presumed p78 mRNA cap site conferred human alpha interferon (IFN-alpha) inducibility to the cat reporter gene. The p78 protein accumulated to high levels in cells treated with IFN-alpha. In contrast, the p78-related protein was not expressed at detectable levels. The rate of decay of p78 levels in diploid cells after a 24-h treatment with IFN-alpha was much slower than the rate of decay of the antiviral state against influenza A virus and vesicular stomatitis virus, suggesting that the p78 protein is probably not involved in an antiviral mechanism. Furthermore, we showed that these proteins, as well as the homologous mouse Mx protein, possess three consensus elements in proper spacing, characteristic of GTP-binding proteins.

Integration host factor (IHF) protein is the only host-encoded protein known to bind and to affect replication of the gamma origin of Escherichia coli plasmid R6K. We examined the ability of R6K origins to replicate in cells lacking either of the two subunits of IHF. As shown previously, the gamma origin cannot replicate in IHF-deficient cells. However, this inability to replicate was relieved under the following conditions: underproduction of the wild-type pi replication protein of R6K or production of normal levels of mutant pi proteins which exhibit relaxed replication control. The copy number of plasmids containing the primary R6K origins (alpha and beta) is substantially reduced in IHF-deficient bacteria. Furthermore, replication of these plasmids is completely inhibited if the IHF-deficient strains contain a helper plasmid producing additional wild-type pi protein. IHF protein has previously been shown to bind to two sites within the gamma origin. These sites flank a central repeat segment which binds pi protein. We propose a model in which IHF binding to its sites reduces the replication inhibitor activity of pi protein at all three R6K origins.

HIV‐1 gp120/gp160 is known to disturb the activity of p56lck, protein kinase C (PKC) and Ca2+homeostasis in T lymphocytes. We found that gp160 decreases the Kv1.3 current of Jurkat E6.1 cells probably by increasing the PKC‐dependent phosphorylation of Kv channel protein after 5 days. This decrease is dose‐dependent. In contrast, gp160 did not decrease the Kv1.3 current of the JCaM1.6 cell line, a p56lck‐defective Jurkat cell line. This shows that p56lckwas at the beginning of the events which induced the Kv1.3 current decrease. As a consequence of this decrease, Jurkat E6.1 cells were depolarized and exhibited a volume increase.

Hydrological features, water quality and trophic status were determined in this study for Polyphyto reservoir (filled up in 1975), to examine the possible uses of its water, and especially for aquaculture. The river Aliakmon represents the main inflow to the reservoir, while the use of the reservoir's water for cooling requirements of thermal electric plants and hydroelectricity generation are the main outflows. According to OECD's probabilistic approach and considering mean total phorphorus (34 g 1∼'), mean chlorophyll-a (4.10 mg I"1), and maximum chlorophyll-a (18.0 mg I"1) concentrations the reservoir is mesotrophic with a tendency to become eutrophic. The actual phosphorus loading was found 1.67gm-2 y-1 while critical phosphorus loading 0.510 g m-2 y-1. The water quality is suitable for aquaculture development.

In the current design of ITER primary wall, 316LN stainless steel is the reference structural material. Austenitic stainless steel is used for water-cooling channels and structures. As material data on hot isostatic pressed (HIP) 316LN were not available in open literature and from powder producers, the main properties of unirradiated samples have been measured in CEA/CEREM. Fully dense material without any porosity is obtained when appropriate HIP parameters are applied. Microstructural examination and mechanical properties are confirmed that the HIPed 316LN material is equivalent to a very good fine-grain, isotropic and uniformly forged 316LN. Moreover, ultrasonic inspection showed that this fine and uniform microstructure produced a remarkably low noise, which allow the use of transverse waves at very high frequencies (4 MHz). Defects undetectable in forged material will be easily detected in HIPed material.

This paper presents recent developments on DS-Cu and CuCrZr alloys and their joining to 316LN stainless steel by hot isostatic pressing (HIP). Optimized HIP cycle temperature and further treatments depend on the copper alloy. For CuCrZr, after HIP cycle, a thermal treatment is needed to restore its mechanical and microstructural properties. Tensile and fatigue testing, performed at room temperature and at 300°C, indicate convenient enough properties of the joints for both solid alloys. However, using DS-Cu plate, low short transverse ductility and weak fatigue properties are observed. To improve its mechanical properties, investigations will be focused on the initial Glidcop®powder. Prior to licensing this advanced Cu to SS joining technique, more analysis and improvement of the process need to be pursued, including the development of advanced NDE technique for full controllability of the joints.

Non-inductive current drive using second harmonic ECRH at both 28 GHz and 60 GHz has been studied in the CLEO tokamak. At 60 GHz, RF driven currents of up to 5 kA have been observed at e = 4 × 1018m?3for 185 kW of injected power, indicating an efficiency of ? ? eIRFR0/PRF= 0.001 (1020m?3, A, m, W?1). The RF driven current scaled linearly with total plasma current in the range of 5-15 kA and was maximized when the cyclotron resonance was located near to the centre of the plasma. Sawtooth activity was normally strongly affected and transient sawtooth stabilization was often observed. With detailed theoretical studies it is possible to reproduce both the high absorption efficiencies and the scaling of RF driven current with resonance position seen in the 60 GHz experiments. However, the magnitude of the observed current is a factor of about three below that theoretically predicted. At 28 GHz, no evidence of RF driven current could be detected. Possible reasons for this are discussed.

The occurrence (or not) of a ferroelectric phase transition and the field induced ferroelectric to relaxor states transition has been studied through dielectric susceptibility and pyroelectric current experiments in the x/65/35 PLZT series (x=5 to 12). The results are qualitatively interpreted using random field theory principles.

Molecular dynamics simulation was used to study the intermolecular structure of carbonyl sulphide (OCS) diluted in argon at different densities and at room temperature. The intermolecular interactions between argon and OCS were investigated and an accurate effective atom-atom pairwise additive Lennard-Jones potential was proposed. The interaction model predicts a non-linear, T-shaped dimer structure in excellent agreement with experiment. The center of mass and the relevant site-site pair correlation functions, self-diffusion coefficients, and thermodynamic properties of the molecular system were calculated and analyzed. At low densities we found the nearest configuration to be maximal 1 argon with a nearly T-shaped (1:1) structure located on the CO bond. At higher densities this configuration is extended to maximal 2 or 3 argon atoms. The local structure has been discussed in the sense of its estimated duration (0.4–0.6 ps). This reflects the existence of transient “molecular clusters”.

Occupational eosinophilic bronchitis (OEB) has been described only as anecdotal case reports.

IP3Rs (inositol 1,4,5-trisphosphate receptors) are expressed in the membranes of non-mitochondrial organelles in most animal cells, but their presence and role within the plasma membrane are unclear. Whole-cell patch–clamp recording from DT40 cells expressing native or mutated IP3Rs has established that each cell expresses just two or three functional IP3Rs in its plasma membrane. Only approx. 50% of the Ca2+ entry evoked by stimulation of the B-cell receptor is mediated by store-operated Ca2+ entry, the remainder appears to be carried by the IP3Rs expressed in the plasma membrane. Ca2+ entering the cell via just two large-conductance IP3Rs is likely to have very different functional consequences from the comparable amount of Ca2+ that enters through the several thousand low-conductance store-operated channels.

Complications of gunshot injuries of the kidney usually present in the early postoperative period. We describe a case of a cartridge's plastic detonating cap retained in the renal pelvis of a young male patient for 12 years. Renal colic was the cause of admission. This missile's part was mimicking a renal stone on both an intravenous urogram and a CT scan. The nature of the "stone" was identified during a percutaneous nephrolithotomy procedure during which the foreign body was removed.

Non‐inactivating outward rectifying K+channel currents have been identified in a variety of plant cell types and species. The present study of laticifer protoplasts from Hevea brasiliensis, cells which are specialized for stress response, has revealed, through a switch‐clamp method, an outward rectifying current displaying rapid inactivation. The inactivation depended on the external K+concentration and on the voltage. This current inactivation appeared clearly different from all those previously described in plant cells and it shared homology with current kinetics of animal Shakerfamily channels. These results, given the recent cloning of plant K+channel β‐subunits, shed new light on possible plant K+channel regulation.

Non-inactivating outward rectifying K +channel currents have been identified in a variety of plant cell types and species. The present study of laticifer protoplasts from Hevea brasiliensis, cells which are specialized for stress response, has revealed, through a switch-clamp method, an outward rectifying current displaying rapid inactivation. The inactivation depended on the external K +concentration and on the voltage. This current inactivation appeared clearly different from all those previously described in plant cells and it shared homology with current kinetics of animal Shakerfamily channels. These results, given the recent cloning of plant K +channel β-subunits, shed new light on possible plant K +channel regulation.

La neurocysticercose, parasitose contractée par l’ingestion d’œufs de TaeniaSolium est la première cause de convulsions dans les pays en voie de développement. Son implication dans les AVC est discutée.

IT is known theoretically, from the Appleton–Hartree equation1, that propagation through a plasma of a plane electromagnetic wave, having a frequency below the critical frequency of the plasma, is possible in the presence of a steady magnetic field applied parallel to the direction of propagation, but only if this field is strong enough to cause an electron cyclotron frequency which exceeds the propagated frequency. Propagation of a microwave signal in such a high-density magnetized plasma was observed by Gallet et al.2

For Abstract see ChemInform Abstract in Full Text.

For Abstract see ChemInform Abstract in Full Text.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.