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In the framework of studies for the disposal of radioactive waste, ONDRAF/NIRAS, the Belgian National Agency for Radioactive Waste and enriched Fissile Materials investigates the option of a geological repository. In a geological repository, the waste is sidelined within a deep and stable geological layer, named host rock, behind a whole series of artificial barriers. Together, natural and artificial barriers ensure the isolation of waste, their confinement and the delay and spread of release of radioactive substances. The interaction of the host rock and the concrete support of disposal galleries is investigated to analyse the long-term sustainability of the structure. The host rock considered in this study is a poorly indurated clay present in the northern part of the Belgium, the Boom Clay. The behaviour of the interface between the Boom Clay and the concrete of the galleries is studied experimentally from both mechanical and gas transfer perspectives. Samples have been prepared consisting of two half cylinders, one made of concrete and the other one of Boom Clay to obtain an interface. A dedicated device has been designed using an HOEK type cell, which allow applying confining pressure to simulate lithostatic loading, injecting gas to measure transfer properties and generating relative displacement of both sides of the interface. Mechanical behaviour of the interface under short loading has first been studied. One originality of this study consists in using gas injection and Poiseuille’s law to monitor and quantify the opening and closure of the interface during mechanical loading. A partial irreversible closure of the interface and effects of long term loading have been observed. By increasing the confinement, the opening of the interface (clay-concrete) gradually decreases (initially 38 μm for 1.2 MPa of confining pressure) until it reaches 5 μm for 4.5 MPa. There is moderate expected irreversibility during unloading (19 μm at 1.7 MPa). The objective is to identify the main parameters allowing predicting the properties of the interface, such as initial roughness of the interface, water content, applied stress and time. The second part of the work consists in studying transfer properties at the interface. The aim is to identify paths available for gas produced during waste storage.

Iron isotopic compositions potentially provide a powerful new tracer of planetary formation and differentiation processes and of secular and spatial changes in mantle oxidation state. However, the processes governing iron isotope fractionation in igneous rocks remain poorly understood. Here we show that there are significant variations in the iron isotope compositions (δ57/54Fe) of mantle rocks (0.9‰) and minerals (olivines 0.6‰, clinopyroxenes 0.97permil; and orthopyroxenes 0.8‰), with spinels showing the greatest total variation of 1.7‰. Positive linear functional relationships with slopes that are, within error, equal to unity are found between the δ57/54Fe values of coexisting orthopyroxene, clinopyroxene and olivine, strongly suggesting that the δ57/54Fe values of these minerals reflect intra-sample mineral-mineral isotopic equilibrium. Positive correlations between the δ57/54Fe values of silicate minerals and spinels also exist, although they are more scattered, which could be caused by late disturbance of mineral-spinel isotopic equilibrium. Bulk-rock, clinopyroxene and spinel δ57/54Fe values correlate with chemical indices of both melt extraction and oxidation. Iron isotope fractionation during spinel-facies partial melting is investigated using simple models, which demonstrate that the maximum expected fractionation between melt and residue will be ∼0.5‰, with the residue becoming isotopically light relative to the melt and to the initial source region. Hence melt extraction, in combination with significant changes in mantle oxidation state, may be an explanation for Fe isotopic variations in mantle peridotites. Metasomatism of the sub-arc mantle by iron-rich silicate melts originating from the subducting slab may also explain the light bulk-sample δ57/54Fe values of some arc peridotites (-0.2‰ to -0.6‰), but mass-balance calculations require these metasomatic agents to have extreme δ57/54Fe values (e.g. -3.0‰). The large differences in the δ57/54Fe values of garnet and spinel facies rocks are likely to be caused by the contrasting behaviour of Fe3+ during melting in the spinel and garnet facies. However, there is little difference in the δ57/54Fe values of MORB and OIB, despite the fact that OIB are considered, on the basis of incompatible element abundances, to arise dominantly by melting in the garnet stability field. Given that iron is a relatively compatible element, the similarities in the δ57/54Fe values of MORB and OIB provide strong evidence that MORB and OIB are both dominated by melting in the spinel facies. © 2005 Elsevier B.V. All rights reserved.

Iron isotopic compositions measured in chondrules from various chondrites vary between δ 57Fe/ 54Fe = +0.9‰ and -2.0‰, a larger range than for igneous rocks. Whether these compositions were inherited from chondrule precursors, resulted from the chondrule-forming process itself or were produced by later parent body alteration is as yet unclear. Since iron metal is a common phase in some chondrules, it is important to explore a possible link between the metal formation process and the observed iron isotope mass fractionation. In this experimental study we have heated a fayalite-rich composition under reducing conditions for heating times ranging from 2 min to 6 h. We performed chemical and iron isotope analyses of the product phases, iron metal and silicate glass. We demonstrated a lack of evaporation of Fe from the silicate melt in similar isothermal experiments performed under non-reducing conditions. Therefore, the measured isotopic mass fractionation in the glass, ranging between -0.32‰ and +3.0‰, is attributed to the reduction process. It is explained by the faster transport of lighter iron isotopes to the surface where reduction occurs, and is analogous to kinetic isotope fractionation observed in diffusion couples [Richter, F.M., Davis, A.M., Depaolo, D.J., Watson, E.B., 2003. Isotope fractionation by chemical diffusion between molten basalt and rhyolite. Geochim. Cosmochim. Acta 67, 3905-3923]. The metal phase contains 90-99.8% of the Fe in the system and lacks significant isotopic mass fractionation, with values remaining similar to that of the starting material throughout. The maximum iron isotope mass fractionation in the glass was achieved within 1 h and was followed by an isotopic exchange and re-equilibration with the metal phase (incomplete at ∼6 h). This study demonstrates that reduction of silicates at high temperatures can trigger iron isotopic fractionation comparable in its bulk range to that observed in chondrules. Furthermore, if metal in Type I chondrules was formed by reduction of Fe silicate, our observed isotopic fractionations constrain chondrule formation times to approximately 60 min, consistent with previous work. © 2006 Elsevier Inc. All rights reserved.

The oxygen fugacity of the mantle exerts a fundamental influence on mantle melting, volatile speciation, and the development of the atmosphere. However, its evolution through time is poorly understood. Changes in mantle oxidation state should be reflected in the Fe 3+ /Fe 2+ of mantle minerals, and hence in stable iron isotope fractionation. Here it is shown that there are substantial (1.7 per mil) systematic variations in the iron isotope compositions (δ 57/54 Fe) of mantle spinels. Spinel δ 57/54 Fe values correlate with relative oxygen fugacity, Fe 3+ /ΣFe, and chromium number, and provide a proxy of changes in mantle oxidation state, melting, and volatile recycling.

Two Fe–Mn crusts from the central Pacific and one from the central Atlantic were dated by osmium (Os) isotope stratigraphy. All three crusts show a pronounced Os isotope minimum around 12 Ma. The Os/Os decreased from 0.8 at 15 Ma to 0.7 at 12 Ma and reached a value of 0.8 again at 9 Ma indicating symmetrical shoulders of this excursion. In the modern ocean, the concentration of dissolved Os as well as the Os/Os of 1.06 are essentially homogenous, which is accurately reflected by recent marine sediments in several depositional settings. The observed negative Os isotope excursion at 12 Ma, which has not been observed in earlier studies of pelagic and metalliferous sediments, thus must have been caused by an event that changed the osmium isotope signature of global seawater. Possible interpretations for the Mid-Miocene decrease include changes in continental weathering intensity i.e. a reduction of the radiogenic Os flux, or an increase in the unradiogenic input fluxes, such as intensified weathering of ultramafic rocks, exhalations derived from large igneous flood basalts or their weathering, a meteorite impact, or a combination of several of these reasons. In the Mid-Miocene there was at least one larger meteorite impact, the Nordlinger Ries Crater and at the same time the large Columbia River igneous flood basalt province formed. Application of a simple mass balance model RSW = Rr (fr) + Ru (1 fr) where fr is the ratio of riverine flux of Os to the total flux of Os, and were subscripts sw, r and u refer to seawater, riverine and unradiogenic, respectively, shows that exhalations from a large igneous flood basalt are the most likely cause of the observed minimum. Therefore the most viable explanation of the unradiogenic Os is the eruption of the Columbia River flood basalts. Such an interpretation is also possible for the two other more pronounced minima in the Cenozoic Os isotope record of seawater that have previously been reported for the Cretaceous/Tertiary and Eocene/Oligocene boundaries. The exhalations of the Deccan Traps and the Ethiopian Flood Basalts were large enough to release sufficient amounts of unradiogenic Os into the ocean to cause the observed minima.

Three ferromanganese crusts from the northeast, northwest and central Atlantic were re-dated using osmium (Os) isotope stratigraphy and yield ages from middle Miocene to the present. The three Os isotope records do not show evidence for growth hiatuses. The reconstructed Os isotope-based growth rates for the sections older than 10 Ma are higher than those determined previously by the combined beryllium isotope (10Be/9Be) and cobalt (Co) constant-flux methods, which results in a decrease in the maximum age of each crust. This re-dating does not lead to significant changes to the interpretation of previously determined radiogenic isotope neodymium, lead (Nd, Pb) time series because the variability of these isotopes was very small in the records of the three crusts prior to 10 Ma. The Os isotope record of the central Atlantic crust shows a pronounced minimum during the middle Miocene between 15 and 12 Ma, similar to a minimum previously observed in two ferromanganese crusts from the central Pacific. For the other two Atlantic crusts, the Os isotope records and their calibration to the global seawater curve for the middle Miocene are either more uncertain or too short and thus do not allow for a reliable identification of an isotopic minimum. Similar to pronounced minima reported previously for the Cretaceous/Tertiary and Eocene/Oligocene boundaries, possible interpretations for the newly identified middle Miocene Os isotope minimum include changes in weathering intensity and/or a meteorite impact coinciding with the formation of the Nördlinger Ries Crater. It is suggested that the eruption and weathering of the Columbia River flood basalts provided a significant amount of the unradiogenic Os required to produce the middle Miocene minimum. © 2008 Elsevier B.V.

Ferromanganese crusts provide records of long term change in ocean circulation and continental weathering. However, calibrating their age prior to 10 Ma has been entirely based on empirical growth rate models using Co concentrations, which have inherently large uncertainties and fail to detect hiatuses and erosional events. We present a new method for dating these crusts by measuring their osmium (Os) isotope record and matching it to the well-known marine Os isotope evolution of the past 80 Ma. The well-characterised crust CD29-2 from the central Pacific, was believed to define a record of paleooceanographic change from 50 Ma. Previous growth rate estimates based on the Co method are consistent with the new Os isotope stratigraphy but the dating was grossly inaccurate due to long hiatuses that are now detectable. The new chronology shows that it in fact started growing prior to 70 Ma in the late Cretaceous and stopped growing or was eroded between 13.5 and 47 Ma. With this new technique it is now possible to exploit the full potential of the oceanographic and climatic records stored in Fe-Mn crusts. © 2005 Elsevier B.V. All rights reserved.

Seven bulk chondrites, with δ 57 Fe/ 54 Fe values between −0.1‰ and 0‰ relative to IRMM-14, tend to be slightly lighter than 11 bulk iron meteorites, which have δ 57 Fe/ 54 Fe values ranging from 0.04‰ to 0.2‰. At the mineral scale, taenite from two iron meteorites, Cranbourne and Toluca, shows δ 57 Fe/ 54 Fe values heavier by up to 0.3‰ than their kamacite counterpart, thus calling into question the significance of bulk iron meteorite data. On three pallasites (Esquel, Marjalahti and Springwater) we measured a heavier iron isotope composition for the metal fractions compared to the coexisting olivines as previously observed on two other pallasites (Eagle Station and Imilac), but the range of δ 57 Fe/ 54 Fe differences (from 0.32‰ to 0.07‰) is larger than that originally found. Troilite from two pallasites appears to be even heavier than the metal fraction, whereas schreibersite is lighter than its olivine counterpart. There is thus a general tendency for minerals within a given rock to show a heavier Fe isotope composition as the coordination number of Fe increases, although troilite is an exception to this rule. Iron meteorites are classically considered as remnants of asteroid cores and pallasites as core–mantle interfaces. The simultaneous finding that the metal fractions of pallasites have a higher δ 57 Fe/ 54 Fe signature than the coexisting olivines, and that the iron meteorites are slightly heavier than chondrites could be taken as an indication that planetary core–mantle differentiation is accompanied by sizeable iron isotope fractionation. In this hypothesis, mass balance constraints imply that resultant planetary mantles should be isotopically lighter than the chondritic starting material. That is not observed, however, since all planetary mantles analyzed so far have δ 57 Fe/ 54 Fe values equivalent to or heavier than those of chondrites. It thus appears that the moderate temperature and pressure metal–silicate fractionation that occurred in pallasite and iron parent bodies is not readily transposable to planets as far as Fe isotopes are concerned. Instead, these mantle signatures could reflect equilibrium fractionation at a higher temperature, or the lack of a global core–mantle equilibration at the planetary scale. Overall, these new results show that the mass-dependent isotopic scatter observed among inner solar system bodies from the bulk-rock to the planetary scale (∼0.3‰ δ 57 Fe/ 54 Fe) is more restricted than previously thought. This likely confirms a homogenization process that occurred in the protoplanetary accretion disk, between refractory inclusion condensation and chondrule formation.

The iron (Fe) isotope compositions of 37 hydrogenetic ferromanganese deposits from various oceans have been analysed by MC-ICPMS; they permit the construction of a global map of Fe isotopic values. The isotopic compositions range between −1.2 and −0.1‰ in δ57FeIRMM14. Averages for the Atlantic and the Pacific are −0.41 and −0.88‰, but their standard deviations are identical (0.27, 1σ) and the data very largely overlap. No correlation is found with Pb or Nd isotope compositions and there is no evidence that the observed oceanic Fe isotopic heterogeneity is directly controlled by variations in continental sources. The small quantities of Fe that can be introduced from hydrothermal sources render as unlikely the possibility that the isotopic variations reflect variable proportions of continental and hydrothermal Fe, as recently proposed. The more likely explanation is that the variations are induced locally within the ocean. The exact sources of fractionation remain unclear. Likely possibilities are the dissolution and reprecipitation processes that liberate Fe from sediments during anoxic events, dissolution in surface waters or processes occurring during growth of the crusts

The behavior of dissolved osmium at the river/ocean interface was studied in the Lena River estuary. Dissolved osmium removal is observed at very low salinities. The loss is estimated to be 28% of the dissolved concentration of the river. The removal cannot be related to the flocculation of iron oxide–organic matter colloids, but occurs simultaneously with the loss of aluminum. The proposed mechanism is the adsorption of dissolved osmium on suspended particles in the maximum turbidity zone. If this is correct, then the removal of osmium in estuaries is probably a common phenomenon. No contribution of osmium from the sediments is detected but neither the samples nor the stratified nature of the estuary are favorable to the study of a flux from sediments. If this finding can be generalized, the estimated global riverine flux of osmium to the ocean has to be recalculated and the osmium residence time in the ocean would change from 3.3×104 yr to 4.6×104 yr.

HT-Lix0CoO2 phases were synthesised via a solid state reaction with nominal Li/Co ratios x0=0.90, 1.0, 1.05 and 1.10. These materials were studied by X-ray and neutron diffraction, galvanostatic lithium intercalation/deintercalation and electrical measurements as well as 7Li MAS NMR spectroscopy. While the galvanostatic charge curve of the stoichiometric material shows a voltage plateau at ca. 3.93 V for 0.75≤x≤0.94 and a particular feature for Li0.5CoO2 (x0=1.0) due to a monoclinic distortion, the charge curves of materials with x0=1.05 and 1.10 do not present the voltage plateau nor the monoclinic distortion. XRD studies show the occurrence of a solid solution in the 0.60≤x≤1.10 domain. 7Li MAS NMR spectra of Lix0CoO2 materials with x0>1 exhibit three new signals at 190, −18 and −40 ppm in addition to the signal at 0 ppm resulting from the presence of diamagnetic CoIII. A 7Li MAS NMR study of the materials obtained by electrochemical deintercalation and reintercalation of lithium from Li1.10CoO2 shows that these new features do not arise from lithiated surface species or from interstitial Li+. On the basis of our general knowledge of Li NMR in comparable materials with electron spins, we suggest the presence of paramagnetic low-spin CoII and of a simultaneous cobalt and oxygen deficiency in samples with x0>1.0.

The osmium concentration ([Os]) and isotopic composition were determined in a set of 17 of the largest rivers of the world. [Os] varies between 4.6 and 52.1 pg/kg and the 187Os/188Os ratio varies between 0.64 and 2.94. Measurement of rainwater samples shows that there is no input of oceanic Os to the continent through rain. Assuming a negligible anthropogenic Os input in the dissolved load, the natural average river water has an Os concentration of 7.9 pg/kg and a mean 187Os/188Os ratio of 1.54. The total riverine flux of Os to the ocean is estimated to be 295 kg/yr. The dissolved Os flux from island arcs and oceanic islands represents less than 5% of the total riverine flux and is not further considered. The continental Os flux to the ocean is then represented by the riverine flux, as dissolved Os from eolian dust and glacial sediments is negligible. Assuming steady state, it is possible to estimate a maximum unradiogenic flux to the ocean of 126 kg/yr (cosmic dust or mantle-derived) and an oceanic residence time between 2.5×104 and 5.4×104 with a mean of 3.5×104 year. The estimation of the flux of dissolved cosmic particles shows that their contribution to the seawater Os would be ∼14% of the contribution of the unradiogenic component, which means that the mantle-derived flux should contribute a major part. The first results on water from high temperature axial hydrothermal systems indicate that their input is probably negligible, which would necessitate that dominant contribution from the low temperature alteration of the oceanic crust and/or of the ultramafic exposures contributes dominantly to the input of unradiogenic Os to the seawater. We show that it would be necessary to leach 1.3% of the Os contained in the volume of ultramafic exposures accessible to seawater to account for all of the unradiogenic component contribution. Another simpler but less likely possibility is that the dissolved cosmic dust represents the only source of dissolved unradiogenic Os to the ocean in which case the riverine input represents 94% of the total dissolved flux to the ocean instead of 70%. The modern global dissolved Os flux to the ocean would then have a 187Os/188Os ratio of 1.44 instead of 1.06 and the system would be far from steady state.

In the present study, we investigated whether cholecystokinin (CCK) or its structurally related peptide gastrin participates in long term regulation of adipocyte leptin secretion. The levels of circulating leptin observed after 2 and 6 h of refeeding in 18-h fast rats were significantly lowered by injection of the specific gastrin/CCK-B receptor antagonist YM022 at doses that did not affect feeding behavior. Moreover, in normally fed animals, circulating leptin was markedly decreased by chronic injection of YM022 (from 4 ± 0.6 to 2.1 ± 0.5 ng/ml). Consistent with these observations, YM022 treatment decreased leptin messenger RNA (mRNA) levels and increased the leptin content in rat epididymal fat tissue. Rat adipocytes exclusively contain gastrin/CCK-B receptor mRNA, but not CCK-A receptor mRNA. Furthermore, adipocyte membranes bound[ 125I]CCK-8 in a saturable manner, with kinetics consistent with a single class of high affinity sites with a Kd of 0.2 nm. These data argue for a physiological role for the ...

Osmium concentrations in corals are very low (

Lithium batteries are being intensively studied owing to the considerable challenge they represent for applications. From a fundamental point of view, the shape of the charge/discharge curves gives information on all the structural and physical properties modifications which occur during the intercalation/deintercalation process. Moreover, the electrochemical reaction is a way of synthesising metastable materials which cannot be obtained by classical methods. The ease of monitoring very accurately either the cell voltage (oxidation state of the material) or the number of electrons transferred (lithium content in the material) makes lithium batteries a new very convenient tool for the solid state chemist. Typical examples are presented.

The circulating peptide leptin, which is the product of the ob gene, provides feedback information on the size of fat stores to central Ob receptors that control food intake and body-weight homeostasis. Leptin has so far been reported to be secreted only by adipocytes and the placenta. Here we show that leptin messenger RNA and leptin protein are present in rat gastric epithelium, and that cells in the glands of the gastric fundic mucosa are immunoreactive for leptin. The physiological function of this previously unsuspected source of leptin is unknown. However, both feeding and administration of CCK-8 (the biologically active carboxy-terminal end of cholecystokinin) result in a rapid and large decrease in both leptin cell immunoreactivity and the leptin content of the fundic epithelium, with a concomitant increase in the concentration of leptin in the plasma. These results indicate that gastric leptin may be involved in early CCK-mediated effects activated by food intake, possibly including satiety.

The human immature K562 erythroid cell line was studied for its capacity to produce and to metabolize the phospholipid molecule platelet-activating factor (PAF). K562 cells produced PAF under calcium ionophore stimulation. Lyso PAF and acetyl-CoA (the acetate donor molecule for the acetylation of lyso PAF into PAF) had no effect on the amounts of PAF produced by ionophore-stimulated cells. The metabolism of PAF and lyso PAF by K562 cells was compared to that of freshly-isolated human bone marrow erythroblasts and blood erythrocytes. K562 cells rapidly metabolized [3H]PAF and [3H]lyso PAF with 1-alkyl analogue of phosphatidylcholine as the major metabolic product. In contrast, blood erythrocytes did not. PAF acetylhydrolase activity levels in K562 cells and bone marrow erythroblasts were similar and higher than in blood erythrocytes. PAF (1–100nM) stimulated [3H]thymidine incorporation in K562 cells grown in low serum concentration, a non-metabolizable PAF agonist being more potent than PAF to stimulate thymidine incorporation. PAF receptor mRNA was detected in K562 cells by polymerase chain reaction on reverse transcripts. The present study demonstrates that K562 cells produce and metabolize PAF and underlines the putative role of erythroid precursors in the modulation of bone marrow PAF concentrations. The effect of PAF on the growth of K562 cells might be mediated through PAF receptors suggesting a potential role of PAF on the proliferation and functions of human erythroid marrow precursors.

The beta 3-adrenoceptor (beta 3-AR) agonist SR-58611A inverted question markethyl-[(7s)-7-[[(2R)-2-(3-chlorophenyl)-2-hydroxyethyl]amino]5, 6,7,8-tetrahydronaphth-2-yl]oxyacetate hydrochloride inverted question mark stimulated somatostatin and gastrin releases in isolated rat gastric antral epithelial cells. Stimulation was a concentration-dependent process with 50% effective concentrations of 2.7 +/- 1.1 and 3.8 +/- 1.9 nM compared with 209 +/- 71 and 230 +/- 51 nM for isoproterenol, respectively. It was inhibited by selective beta-AR antagonists with the following rank order of potency: SR-59230A 3-(2-ethylphenoxy)1-[(1S)-1,2,3,4-tetrahydronaphth- 1-ylamino]-(2S)-2-propranol oxalate; beta 3-AR antagonist > ICI-118551[erythro-(+/-)-1-(7-methylindan-4-yloxy)-3- isopropylaminobutan-2-ol-hydrochloride; beta 2-AR antagonist > CGP-20712A[(+/-)-[2-(3-carbarmoyl-4-hydroxyphenoxy)-et hyl- amino]-3-[4 (1-methyl-4-trifluoromethyl-2-imidazolyl)-phenoxy]- 2-propranol; beta 1-AR antagonist]. Furthermore, specific binding of 125I-cyanopindolol to the isolated cells was demonstrated and was displaced by the beta-AR antagonists according to the same rank order of potency and with apparent dissociation constants consistent with the 50% inhibitory concentrations for SR-58611A-stimulated somatostatin and gastrin releases. In addition, the presence of beta 3-AR mRNA was detected by reverse transcriptase polymerase chain reaction. These findings provide the first evidence for a gastric beta 3-AR mediating catecholamine stimulation of gastrin and somatostatin releases from antral cells.

Macrophage inflammatory proteins-1 (MIP-1) alpha and beta are members of the C-C branch of the platelet factor 4 superfamily of cytokines, recently designated the "chemokine" superfamily. It has been suggested that the major cellular targets for the biologic activities of the C-C chemokines are the mononuclear leukocytes. However, the original designation of murine MIP-1 proteins as inflammatory mediators was based on suggestions that they activated neutrophil functions such as chemotaxis, the respiratory burst, and degranulation. In this study, we have evaluated the ability of human (Hu) MIP-1 alpha and beta to affect purified human neutrophil function. Although both rHuMIP-1 alpha and -1 beta stimulated significant calcium mobilization in human monocytes, only HuMIP-1 alpha exerted a detectable effect on neutrophils. HuMIP-1 alpha stimulated a small, dose-dependent increase in intracellular calcium, which was accompanied by a simultaneous change in right-angle light scatter, the latter indicating induction of shape change. While the effect of HuMIP-1 alpha on calcium mobilization in neutrophils was small when compared with that elicited by IL-8 or Gro alpha, it had similar characteristics to that by other receptor-dependent neutrophil agonists in that it was dependent on pertussis toxin-sensitive G proteins and on both mobilization of calcium from intracellular sources as well as influx from the extracellular environment. In addition, stimulation of neutrophils with HuMIP-1 alpha led to desensitization to subsequent additions of HuMIP-1 alpha. The stimulatory effect of HuMIP-1 alpha on neutrophil calcium mobilization and shape change was not coupled to other standard measures of neutrophil effector function. For instance, neither HuMIP-1 alpha nor -1 beta had any detectable stimulatory effect on the Na+/H+ antiport, degranulation, actin polymerization, or chemotaxis. Moreover, although HuMIP-1 alpha binding could easily be measured on monocytes or monocytic cell lines, the number of sites were too few to characterize on neutrophils by the same technique. Taken together, these results show that neither HuMIP-1 alpha nor -1 beta stimulate significant neutrophil activation and support the concept that the biologic effects of members of the C-C branch of the platelet factor 4 superfamily are not primarily directed toward neutrophils.

Six monoclonal antibodies directed against enterobacteria were produced and characterized. The specificity of one of these antibodies (CX9/15; immunoglobulin G2a) was studied by indirect immunofluorescence against 259 enterobacterial strains and 125 other gram-negative bacteria. All of the enterobacteria were specifically recognized, the only exception being Erwinia chrysanthemi (one strain tested). Bacteria not belonging to members of the family Enterobacteriaceae were not detected, except for Plesiomonas shigelloides (two strains tested), Aeromonas hydrophila (five strains tested), and Aeromonas sobria (one strain tested). This recognition spectrum strongly suggested that CX9/15 recognized the enterobacterial common antigen. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot (immunoblot) experiments, the six antienterobacteria antibodies presented similar specificities; they all revealed only one band with an apparent molecular weight of about 20,000 from the crude extract of an enterobacterium. The six monoclonal antibodies, and especially CX9/15, can be used to develop new tests for rapid and specific detection of enterobacteria.

It is now established that a large extraterrestrial object hit the Earth at the end of the Cretaceous period, about 65 Ma ago. We have investigated Re-Os, Hf-W, and Mn-Cr isotope systems in sediments from the Cretaceous and the Paleogene in order to characterize the type of impactor. Within the Cretaceous-Tertiary (K-T) boundary layer, extraterrestrial material is mixed with terrestrial material, causing a dilution of the extraterrestrial isotope signature that is difficult to quantify. A phase essentially composed of Ni-rich spinel, formed in the atmosphere mainly from melted projectile material, is likely to contain the extraterrestrial isotopic signature of the impactor. We show that the analysis of spinel is indeed the best approach to determine the initial isotope composition of the impactor, and that W and Cr isotopes confirm that the projectile was a carbonaceous chondrite.

Contexte ERA est une liaison informatique permettant une transmission securisee de donnees immuno-hematologiques entre un laboratoire et l’EFS. Plus de 1540 liaisons sont actuellement fonctionnelles en France. Objectifs Le CNRHP, dans le cadre du suivi de la femme enceinte, realise des groupes, phenotypes, RAI et IAI pour les patientes suivies a l’hopital Trousseau. Une liaison ERA (la 1 re en Ile-de-France) a ete mise en place pour securiser la transmission des donnees du CNRHP vers l’EFS site Trousseau. Methode Apres validation de la connexion a l’aide de jeux de patients tests, redaction d’un protocole d’echange et d’une analyse de risque, l’ARS a autorise l’experimentation. La liaison ERA a ete mise en production en janvier 2014. Un comite de suivi entre l’EFS, le CNRHP, l’ARS et les metiers est regulierement organise, permettant de relever les anomalies constatees, faisant l’objet de fiches d’amelioration continue de la qualite. Resultats Pour l’annee 2014, le nombre de dossiers transmis dans ERA depassait 6000, soit 500 dossiers/mois. Deux cent soixante-douze dossiers ont fait l’objet d’une integration dans Inlog (SIL de l’EFS IDF). L’ensemble des problemes rencontres lors de l’experimentation ont ete resolus. Conclusion L’envoi informatise des donnees du CNRHP vers l’EFS via ERA a atteint ses objectifs en terme de securite. Cependant le maintien d’un circuit papier obligatoire pour permettre l’integration des donnees dans Inlog, du fait du nombre important de parametres non transcodes dans ERA, reste lourd et chronophage pour les cliniciens. L’ensemble des acteurs sont demandeurs d’un nouveau protocole de communication simplifie, exhaustif et bidirectionnel.

Two depth profiles of the osmium concentration and the 187 Os/ 186 Os isotopic ratio in the Indian Ocean showed that the osmium concentration seems to be unaltered by chemical or biological processes occuring in seawater; accordingly, osmium is conservative. These data were obtained from an experimental method that eliminated the problems related to osmium preconcentration. This method led to a new evaluation of the concentration of osmium in seawater; the mean concentration of osmium and the 187 Os/ 186 Os ratio are equal to 10.86 ± 0.07 picograms per kilogram and 8.80 ± 0.07, respectively. The results suggest the existence of an organocomplex that dominates the speciation of osmium in seawater.

Magmatic iron meteorites are considered to be remnants of the metallic cores of differentiated asteroids, and may be used as analogues of planetary core formation. The Fe isotope compositions (δ 57/54Fe) of metal fractions separated from magmatic and non-magmatic iron meteorites span a total range of 0.39‰, with the δ 57/54Fe values of metal fractions separated from the IIAB irons (δ 57/54Fe 0.12 to 0.32‰) being significantly heavier than those from the IIIAB (δ 57/54Fe 0.01 to 0.15‰), IVA (δ 57/54Fe - 0.07 to 0.17‰) and IVB groups (δ 57/54Fe 0.06 to 0.14‰). The δ 57/54Fe values of troilites (FeS) separated from magmatic and non-magmatic irons range from - 0.60 to - 0.12‰, and are isotopically lighter than coexisting metal phases. No systematic relationships exist between metal-sulphide fractionation factor (Δ 57/54Fe M-FeS = δ 57/54Fe metal - δ 57/54Fe FeS) metal composition or meteorite group, however the greatest Δ 57/54Fe M-FeS values recorded for each group are strikingly similar: 0.79, 0.63, 0.76 and 0.74‰ for the IIAB, IIIAB, IAB and IIICD irons, respectively. Δ 57/54Fe M-FeS values display a positive correlation with kamacite bandwidth, i.e. the most slowly-cooled meteorites, which should be closest to diffusive equilibrium, have the greatest Δ 57/54Fe M-FeS values. These observations provide suggestive evidence that Fe isotopic fractionation between metal and troilite is dominated by equilibrium processes and that the maximum Δ 57/54Fe M-FeS value recorded (0.79 ± 0.09‰) is the best estimate of the equilibrium metal-sulphide Fe isotope fractionation factor. Mass balance models using this fractionation factor in conjunction with metal δ 57/54Fe values and published Fe isotope data for pallasites can explain the relatively heavy δ 57/54Fe values of IIAB metals as a function of large amounts of S in the core of the IIAB parent body, in agreement with published experimental work. However, sequestering of isotopically light Fe into the S-bearing parts of planetary cores cannot explain published differences in the average δ 57/54Fe values of mafic rocks and meteorites derived from the Earth, Moon and Mars and 4-Vesta. The heavy δ 57/54Fe value of the Earth's mantle relative to that of Mars and 4-Vesta may reflect isotopic fractionation due to disproportionation of ferrous iron present in the proto-Earth mantle into isotopically heavy ferric iron hosted in perovskite, which is released into the magma ocean, and isotopically light native iron, which partitions into the core. This process cannot take place at significant levels on smaller planets, such as Mars, as perovskite is only stable at pressures > 23 GPa. Interestingly, the average δ 57/54Fe values of mafic terrestrial and lunar samples are very similar if the High-Ti mare basalts are excluded from the latter. If the Moon's mantle is largely derived from the impactor planet then the isotopically heavy signature of the Moon's mantle requires that the impacting planet also had a mantle with a δ 57/54Fe value heavier than that of Mars or 4-Vesta, which then implies that the impactor planet must have been greater in size than Mars. © 2006 Elsevier B.V. All rights reserved.

The iron isotope compositions of Shergotty–Nakhla–Chassigny (SNC) meteorites thought to come from Mars, eucrites and diogenites assumed to sample asteroid 4 Vesta, and rocks from the Moon and Earth have been measured using high precision plasma source mass spectrometry. The means of eight samples from Mars and nine samples from Vesta are within error identical despite a range of rock types. They are lighter by ∼0.1‰ in δ57Fe/54Fe compared to the average of 13 terrestrial mantle-derived rocks. The latter value is identical within uncertainty with a previously published mean of 46 igneous rocks from the Earth. The average for 14 lunar basalts and highland plutonic rocks covering a broad spectrum of major element composition is heavier by ∼0.1‰ in δ57Fe/54Fe relative to our estimate for the Earth's mantle, and therefore ∼0.2‰ heavier than the eucrites, diogenites and SNC meteorites. However, the data scatter somewhat and the Apollo 15 green glass and Apollo 17 orange glass are identical to samples from Mars and Vesta. There is no clear relationship between petrological characteristics and Fe isotope composition despite a wide spectrum of samples. Instead, contrasted planetary isotopic signatures are clearly resolved statistically. After evaluating alternative scenario, it appears that the most plausible explanation for the heavier Fe in the Earth and Moon is that both objects grew via processes that involved partial vaporisation leading to kinetic iron isotope fractionation followed by minor loss. This is consistent with the theory in which the Moon is thought to have originated from a giant impact between the proto-Earth and another planet. Combined with numerical simulations, Fe isotope data can offer the potential to provide constraints on the processes that occurred in planetary accretion.

We propose an original numerical method to measure the differential gain and differential phase. One usually uses an NTSC video signal. These parameters are defined as the difference of gain or phase between two successive video signals. In our CANPCI system, based on data processing with a computer, analog methods are impossible to implement. That is why we have developed a new numerical method. This method uses a dual-tone signal: a small HF signal in amplitude coupled with a strong LF signal. We determine the parameters by using algorithms based on envelope detection for the differential gain and synchronous detection for the differential phase. We give as an example the results obtained with the AD775 from Analog Devices.

This paper reports a yield model merging critical areas computed by a survey sampling based estimation tool (EYES) and a large set of defectivity measurements performed during the fabrication process at the SGS-Thomson Crolles plant. This model is applied to commercial devices processed in a mature 0.5 /spl mu/ technology. The robustness of the model was tested with a large number of lots including multiple products, process versions (routes) and defectivity variations.

International audience; HT-Lix0Co1-yMgyO2 (where x0 is the Li/(Co + Mg) ratio; x0 = 0.98, 1.0, 1.10; y = 0.0, 0.03, 0.06, and 0.10) materials were synthesized via a solid-state reaction. These samples were characterized by X-ray diffraction, 7Li MAS NMR spectroscopy, and electrical properties measurements. The XRD study showed that pure phases are obtained for 0.0 ≤ y < 0.10 and x0 ≥ 1.0. 7Li MAS NMR spectra of the Mg-doped phases exhibit two types of new signals at 55 ppm and 325, 7, −9, and − 27 ppm in addition to the signal at 0 ppm resulting from the presence of diamagnetic CoIII ions. On the basis of our general knowledge of Li NMR in layered oxides with electron spins, we suggest that Mg doping in LiCoO2 always leads to the simultaneous presence of CoIV ions (sharing an itinerant electron hole with neighboring CoIII ions) and, to a smaller extent, of intermediate spin Co3+(IS) ions trapped in a square-based pyramidal environment because of an oxygen vacancy. This feature is further enhanced by lithium overstoichiometry.

In the present study, we investigated whether cholecystokinin (CCK) or its structurally related peptide gastrin participates in long term regulation of adipocyte leptin secretion. The levels of circulating leptin observed after 2 and 6 h of refeeding in 18-h fast rats were significantly lowered by injection of the specific gastrin/CCK-B receptor antagonist YM022 at doses that did not affect feeding behavior. Moreover, in normally fed animals, circulating leptin was markedly decreased by chronic injection of YM022 (from 4 +/- 0.6 to 2.1 +/- 0.5 ng/ml). Consistent with these observations, YM022 treatment decreased leptin messenger RNA (mRNA) levels and increased the leptin content in rat epididymal fat tissue. Rat adipocytes exclusively contain gastrin/CCK-B receptor mRNA, but not CCK-A receptor mRNA. Furthermore, adipocyte membranes bound [125I]CCK-8 in a saturable manner, with kinetics consistent with a single class of high affinity sites with a Kd of 0.2 nM. These data argue for a physiological role for the CCK-B/gastrin receptor in adipocyte leptin regulation. We therefore propose that gastrin is involved in long term regulation of leptin expression and secretion in rat fat tissues through activation of an adipocyte gastrin/CCK-B receptor.

Recent studies suggest that glycine-extended gastrin (G17-gly) stimulates in vitro proliferation of the pancreatic cell line AR4-2J, through selective receptors distinct from the CCK-B/G-receptor mediating the effects of amidated gastrin (G17). The aims of our study were to examine the effects of G17 and G17-gly on the growth of the colorectal cancer cell line LoVo and to determine the receptor involved by using selective receptor-antagonist.Both G17 and G17-gly stimulated [3H]-thymidine incorporation in a concentration-dependent fashion. Maximal stimulation (153 +/- 18% and 166 +/- 17% of control, p0.01) was achieved with 10 nM G17 and 100 nM G17-gly, respectively. These stimulations were fully prevented by the presence of 10 pM YM022, a G/CCK B receptor-antagonist, but unaffected by L364,718, a CCK A receptor-antagonist. Basal growth of LoVo cells was inhibited by YM022 and stimulated by L364,718. CCK A and G/CCK B receptors mRNA were detected in the cells. Gastrin immunoreactivity was detected in the cells (16 pM) and in the extracellular medium (4.5 pM).Both G17 and G17-gly stimulate LoVo cells growth through the activation of a gastrin/CCK B receptor. The evidence for secreted gastrin and CCK A and B receptors mRNA may further suggest the existence of an autocrine loop involving a stimulatory gastrin/CCK B receptor.

To assess institutional performance of key diagnostic and therapeutic interventions and to identify areas amenable to improvement in the management of community-acquired pneumonia (CAP).A chart-based retrospective study.Cook County Hospital, a large, urban, public teaching hospital.Adult inpatients with a hospital discharge diagnosis of CAP.None.Fifty hospital admissions were reviewed. Only 25 patients (50%) had two specimens obtained for blood culture, and sputum was sent for Gram's stain and culture for only 11 patients (22%). Approximately one third of the patients had portable anterior-posterior instead of standard posterior-anterior and lateral chest radiographs performed. Physicians in the emergency department (ED) tended to be less likely to note the presence of multilobar infiltrates or pleural effusions than the attending radiologists. The antibiotic regimens employed in the ED and on the inpatient wards were widely variable. The mean time from hospital entry until administration of the first dose of antibiotics was 5.5 h for the 18 patients for whom treatment was initiated in the ED vs 16.1 h for the 27 patients admitted through the ED for whom therapy was deferred until ward admission (p0.001, Student's t test).Institutional variations in the performance of basic diagnostic and therapeutic interventions for patients with CAP may be substantial. The local performance of these key processes of care should be assessed to help direct the formulation of institutional practice guidelines for the management of CAP.

SUMMARY 1. Sensory nerves serve an afferent role and mediate neurogenic components of inflammation and tissue repair via an axon reflex release of sensory peptides at sites of injury. Dysfunction of these nerves with age could contribute to delayed tissue healing. 2. Complementary animal and human skin models were used in the present studies to investigate changes in the modulation of sensory nerve function by sympathetic efferents during ageing. Laser Doppler flowmetry was used to monitor neurogenic skin vascular responses. 3. The animal model used skin of the hind footpad of anaesthetized rats combined with electrical stimulation of the sciatic nerve, while the human model comprised capsaicin electrophoresis to the volar surface of the forearm. Sympathetic modulation was effected by systemic phentolamine pretreatment in animals and local application in the human model. 4. The results obtained from the human model confirmed the reported decline in sensory nerve function and showed no change in sympathetic modulation with age. The results from the animal model confirm and expand results obtained from the human model. 5. The use of low (5 Hz) and high (15 Hz) frequency electrical stimulation (20 V, 2 ms for 1 min) revealed a preferential response of aged sensory nerves to low-frequency electrical stimulation parameters with differential sympathetic modulation that is dependent on the frequency o. stimulation.

In several tissues including gastric mucosa, somatostatin displays various biological effects. Five seven-transmembrane-domain somatostatin receptor subtypes (SSTR1-5) have been recently cloned and only SSTR1 has been shown to be present in the human stomach. We used the polymerase chain reaction on reverse transcripts (RT-PCR) to characterize further the SSTR's mRNAs in human and rat gastric mucosae and in the human gastric tumoral cell-line HGT1. The SSTRl-5's mRNAs were found in both human fundic and antral mucosae as well as in the HGT1 cell and rat antrum. The four SSTR2-5's mRNAs but not SSTRl's were detected in the rat fundic mucosa. Furthermore, the use of rat isolated and purified fundic mucosal cells allowed us to localize SSTR2-5 in the parietal cell-enriched fraction, whereas SSTR2 and SSTR5 were the only subtypes found in the endocrine cell-enriched fraction. These results are the first to demonstrate the presence of the five SSTR's mRNA subtypes in the stomach.

The beta 3 adrenergic receptor stimulates lipolysis and colonic relaxation in the rat, and, suggestively, in man. Several human forms generated by different mRNA splicings can occur: the A form of 396 amino acids and the B and C forms extended by 12 and 6 amino acids respectively, in the C-terminus region. In order to characterize these different forms as expressed in CHO cells, we studied adenylyl cyclase stimulation by the beta 3 agonists, SR58611A and BRL37344 and its inhibition by the beta 3 antagonist SR59230.This antagonist totally inhibited SR58611-adenylyl cyclase stimulation with the following hierarchy of potency: C formBA. In rat, a unique form is expressed which is close to the human B form. This form was the less sensitive to beta 1 and beta 2 antagonists.These findings constitute a molecular pharmacological basis for the design of beta 3 agonists of therapeutic value.

Variations in the isotopic composition of osmium in seawater, recorded by marine sediments, are a proxy of the relative variations of continent, mantle and meteorites contributions and potentially provide a record of continental weathering. Analyses have been made on several kind of sediment samples but until recently (Sharma et aL, 1997; Koide et aL, 1996) no direct measurement of the present day composition of seawater osmium was carried out because of analytical difficulties. This study presents two depth profiles of the concentration and isotopic composition of osmium in the Indian ocean. Osmium concentration in seawater is a key parameter to determine the residence time of osmium in ocean. This parameter is in tum quite important to under~ stand the significance of the osmium proxy in the ocean as recorded in marine sediments: the residence time determines the response of the ocean to sudden variations in the input of osmium and consequently the shortest period and smallest amplitude of change resolvable by our present analytical precision of osmium measurements.

High temperature Li x0 Co 1-y Ni y O 2 (x 0 = 1.0, 1.10; y = 0.0, 0.03, 0.06, and 0.10) phases were synthesized by solid-state chemistry. Their characterization by X-ray diffraction and galvanostatic measurements shows that 3% of Ni ions substituted for Co in the LiCoO 2 lattice suppress the two-phase domain, related to the semiconductor-to-metal transition, that is observed at the beginning of the charge process in Li x CoO 2 . These ions, trapped in the lattice, prevent the phase separation. On the other hand, more than 10% of Ni ions need to be substituted for Co in order to inhibit the monoclinic distortion due to a lithium/vacancy ordering in the interslab for Li 0.50 Co 1-y Ni y O 2 . Besides, a Li/(Ni + Co) ratio (x 0 ) strictly higher than one in Li x0 Co 0.97 Ni 0.03 O 2 leads, as in the case of the unsubstituted Li 1.10 CoO 2 phase, to the disappearance of all the phase transitions upon deintercalation. 7 Li magic angle spinning nuclear magnetic resonance measurements show that Ni III ions are the only paramagnetic species in the LiCo 1-7 Ni y O 2 phases while in the overlithiated Li x0 Co 1-y Ni y O 2 (x 0 > 1.0) phases, Ni III and intermediate spin Co 3+(1S) are present. This suggests the existence of structural defects associated with O vacancies which are responsible for the suppression of the electronic delocalization and of the lithium/vacancy ordering upon lithium deintercalation.

The effects of two inhibitors of ornithine decarboxylase activity, alpha-difluoromethylornithine (DMFO) and (2R,5R) 6-heptyne-2,5 diamine (HDA), and an inhibitor of S-adenosylmethionine decarboxylase, methylglyoxal bis-guanylhydrazone (MGBG), were tested on casein kinase activity and endogenous phosphorylation in the cytosol fractions of mouse thyroid and a rat prostate tumor model, Dunning R 3327 MAT LyLu subline. When tested at 5 mM, spermine, DMFO, HDA, and MGBG stimulated mouse thyroid casein kinase activity by 230%, 14%, 65% and 106%, respectively. Similar responses were observed in prostate tumor cytosol. In mouse thyroid cytosol, spermine stimulates 32P incorporation primarily into 3 proteins (MW: 107, 88, and 56 kDa). At 5 mM, MGBG partially reproduces the effects of spermine; HDA is less effective and DMFO is without effect. Similar effects were observed on 3 proteins in prostate tumor cytosol with molecular weights of 91, 41, and 32 kDa. These data provide additional support for the hypothesis that the observed synergistic inhibitory effect of DMFO and MGBG on cell growth may not be due solely to the inhibition of polyamine biosynthesis. Our findings suggest that MGBG-mediated reduction in the phosphorylation of casein kinase substrate should be considered as one locus of action.

The authors report the results of 98 cases of esotropia treated by global surgery. They treated 72 "V" syndromes, 22 "A" syndromes and 4 cases without vertical incommitance but presenting visible hyperactivities of the oblique muscles. The alphabetical variations have been treated by weakening of the oblique muscles and sometimes have been treated by weakening of the oblique muscles and sometimes of the vertical recti which are part of the same torsional couple (inferior oblique - inferior rectus in the "V" syndrome, superior oblique - superior rectus in the "A" syndrome). Post-operative improvement has been obtained in 76% of the cases for the "V" syndrome and in 63% of the cases for the "A" syndrome. The surgery of the oblique muscle must be done according to the importance of the incommitance. The arc-technique permits these adjustments. Some pronounced "X" syndromes appear in the post-operative period. All anomalies found during motility examination should be surgically corrected.

The echo doppler exam is very important for the diagnostic, the localisation of cervical artery disease, responsible of eye vascular disease, and help us for the definition of the therapy.