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International audience; Highly enantio- and regioselective (3 + 2) formal cycloaddition of β-substituted ene- and thioenecarbamates as well as cyclic enamides with quinone diimides catalyzed by a BINOL- and SPINOL-derived phosphoric acid is reported. A wide variety of 2,3-disubstituted 2-aminoindolines, including polycyclic ones, were prepared in generally high yields (up to 98%) with moderate to complete diastereoselectivities and in most cases excellent enantioselectivities (up to 99% ee).

A new family of chiral chimeric photo-organocatalysts derived from phosphoric acid were synthesized and their spectroscopic and electrochemical properties were investigated. Then, the ability of these photo-activable molecules to catalyse an asymmetric tandem electrophilic β-amination of enecarbamates was evaluated.

International audience; In this study, the effect of Ti 4+ on the structure of nepheline glass (NaAlSiO 4) is investigated as SiO 2 is systematically replaced with TiO 2. Traditionally, TiO 2 is considered to be a nucleating agent for silicate crystallization but can also be incorporated into the glass network in relatively large amounts as either a network former or modifier depending on its coordination with oxygen. To determine the effect of Ti 4+ on the structure of nepheline glass, X-ray and neutron pair distribution function (PDF) analysis paired with Empirical Potential Structure Refinement (EPSR) were conducted and are supplemented with Raman spectroscopy, electron probe microanalysis, and X-ray absorption spectroscopy (including Extended X-ray Absorption Fine Structure, EXAFS). Through these methods, it has been found that up to 15 mol% (16 wt%) TiO 2 can incorporate into the glass network as a four-fold coordinated species, with a minor contribution of higher coordinated Ti. Between NaAlTi 0.1 Si 0.9 O 4 and NaAlTi 0.2 Si 0.8 O 4 , EXAFS suggests a local structure change in the second coordination sphere of Ti, which changes from Ti-Ti to Ti-Al. Raman spectroscopy also suggests that as Ti content increases, the Na environment becomes more ordered. These results suggest that the Ti activity coefficient and its isotopic fractionation for magnetite and other Ti-bearing minerals should be fairly constant in polymerized melts, such as metaluminous and peraluminous rhyolites.

CO2 degassing of mafic silicate melts is an important part of the terrestrial carbon cycle, at mid-ocean ridges, oceanic hot spots, or in the middle of continents. Deeper CO2-bearing mafic magmas may also exist, such as those suspected in the D″ zone, and certainly existed in the magma ocean of the early Earth. Knowledge of the CO2 solubility in mafic melts at high pressure is therefore important but unknown at present. Results from molecular dynamics simulation (e.g., Guillot and Sator, 2011) predict that CO2 solubility in basalt may be much higher than previously thought at pressures and temperatures relevant to the upper mantle. But some recent models predict low solubility at high pressure (e.g., Eguchi and Dasgupta, 2018). The present study thus experimentally investigates the solubility of CO2 in basalt and andesite in the pressure range 1.5–8.5 GPa at 1820–2130 K in oxidizing conditions. Up to 4 GPa, the quenched samples are essentially vitreous and CO2-saturated. Their CO2 contents are measured using confocal micro-Raman spectroscopy, where we establish an internal calibration line relating CO2 content to the area of the Raman band assigned to the ν1 stretching vibration of carbonate groups. This calibration appears independent from the spectrometer, sample or experimentalist, thus enhancing confidence in this method. At 5 and 8.5 GPa, some of the quenched samples are found partially crystallized. Their CO2 abundance is estimated at micro-scale from Raman mapping, and at large scale from image analysis and presence/absence of vesicles. Over the 1.5–8.5 GPa pressure range, obtained CO2 concentrations vary between 1.8 and > 13.6 wt%. At 5 GPa and 1873 K, the CO2 content in basalt and andesite are similar. These findings experimentally confirm the ability of mafic melts to accommodate large amounts of CO2 at conditions prevailing in the deep Earth. A consequence is that magmas issued from partial melting of carbonate-bearing silicate rocks may ascend with significant quantities of CO2 of several wt% and more: when reaching shallower depths, they may degas large quantities of CO2. Present estimates of the global carbon flux to the atmosphere may thus be underestimated, and implications to early magma ocean degassing may be considered. Other consequences may concern the genesis of kimberlites and carbonatites. We finally speculate that, if silicate melts exist in the D″ zone, significant amounts of carbon may be stored there, and consequences may arise as to carbon sequestration in the core.

International audience; Iron oxidation state and environment in magmas affect their phase diagram and their properties, including viscosity and density, which determine magma mobility and eruptive potential. In turn, magma composition, pressure, temperature and oxygen fugacity affect iron oxidation state and coordination, potentially leading to complex feedbacks associated with magma ascent, degassing and eruption. While equilibrium experiments and models have led to a deep understanding of the role of iron in melts, our knowledge of the effects of disequilibrium processes on iron oxidation state and its structural role in lavas and magmas remains limited. Accordingly, we performed a series of dynamic disequilibrium experiments on a natural melt composition (a phonolite lava from Erebus volcano, Antarctica) at atmospheric pressure, in which oxygen fugacity and temperature were controlled and varied. During the experiments, we continuously measured iron oxidation and coordination using Fe K-edge dispersive X-ray Absorption Spectroscopy (XAS). We found that iron oxidation state changes in the phonolite melt are reversible and well reproduced by existing models. Changes in iron oxidation state are driven by joint diffusion of alkali cations and oxygen anions at magmatic temperatures (~ 1000 °C for Erebus phonolite). However, redox diffusion timescales are too slow for any significant oxygen exchange with the atmosphere at the lava/air interface or via air entrainment. Turning to iron coordination, while Fe 2+ and Fe 3+ are present mostly in an average five-fold coordination, complex coordination variations decoupled from redox changes were detected. The data suggest transitions between Fe 3+ in four-fold and six-fold coordination prior to reduction or as a consequence of oxidation. This questions the possible implication of Fe coordination changes in triggering crystallisation of magnetite nanolites upon magma ascent, and, through such crystallisation events, in promoting magma explosivity.

We present the case of a 21-year-old man admitted to the intensive care unit with multi-organ failure due to multidrug-resistant tuberculosis (TB). TB treatment initially comprised moxifloxacin, ethambutol, linezolid and amikacin administered intravenously. Due to suspected moxifloxacin-induced liver injury, we stopped all fluoroquinolones and switched to bedaquiline (BDQ), which is only available in tablets for oral administration. Since our patient had to be fed through a nasogastric tube (NGT), BDQ was administered after being crushed and dissolved in water; drug pharmacokinetics were studied using repeated blood sampling. Therapeutic drug monitoring showed that BDQ was detectable in blood plasma with a trough concentration above the supposed efficacy threshold, suggesting that this molecule could be administered through NGT.

International audience; A glass‐ceramic waste form is being developed for immobilization of waste streams of alkali (A), alkaline‐earth (AE), rare earth (RE), and transition metals generated by transuranic extraction for reprocessing of used nuclear fuel. Benefits over an alkali borosilicate waste form are realized by the partitioning of the fission product fraction insoluble in glass into a suite of chemically durable crystalline phases through controlled cooling, including (AE,A,RE)MoO4 (powellite) and (RE,A,AE)10Si6O26 (oxyapatite). In this study, a simplified 8‐oxide system (SiO2‐Nd2O3‐CaO‐Na2O‐B2O3‐Al2O3‐MoO3‐ZrO2) was melted, then soaked at various temperatures from 1450 to 1150°C, and subsequently quenched, in order to obtain snapshots into the phase distribution at these temperatures. For these samples, small angle X‐ray and neutron scattering, quantitative X‐ray diffraction, electron microscopy, 23Na nuclear magnetic resonance, Nd3+ visible absorption, and temperature‐dependent viscosity were characterized. In this composition, soak temperatures of urn:x-wiley:00027820:media:jace16406:jace16406-math-00011250°C were necessary to nucleate calcium molybdate (~10‐20 nm in diameter). Further cooling produced oxyapatite and total crystallization increased with lower soak temperatures. Both Na and Nd entered the crystalline phases with lower‐temperature soak conditions. Slow cooling or long isothermal treatments at ~975°C produced significantly higher crystal fractions.

The Raman spectra of glasses containing 0 to 30 mol% Cs2O have been fit successfully with line shapes of dominantly Lorentzian character for the Q3 species, allowing quantification of Q3 and Q4 species intensities (Q represents a Si tetrahedron and the superscript indicates the number of bridging oxygen atoms, BOs, bonded to Si.) The intensity of the Q4 species A1 symmetric stretch is exceptionally weak in vitreous silica (v-SiO2) but it increases dramatically with addition of small amounts of Cs2O to the glass. We propose that Cs, where in close proximity to BO of Q4 species, promotes the polarizability of Q4 tetrahedra and these primed Q4 species (Q4-p) produce a strong Q4 signal. There are, therefore, two variants of the Q4 species, a Q4-p species which produces a strong signal, and an unprimed species (Q4-u) which yields a very weak signal. The increase in the abundance of the primed Q4 species (Q4-p) can be modelled as a function of alkali content using a simple, upper-bounded growth model: XQ4-p = (1 − e−kx) where XQ4-p is the fraction of polarizable Q4 species, k is a constant and x is the mol% counter oxide in the glass (here Cs2O). Comparison of calculated XQ4-p values with experimental results indicates that its cross-section is similar to that of the Q3 species. There is no evidence for a ~1050 cm−1 band in the 5 mol% Cs2O glass spectrum but in the 30 mol% Cs2O glass spectrum about 11% of spectral intensity is observed at about this frequency. The intensity likely results from development of asymmetry on the Q3 band, which increases with Cs2O content of the glass. The asymmetry results from weakened Si O force constants of some Q3 tetrahedra due to charge transfer via Cs BO bonds. As evidence, Si 2p and O 1s X-ray Photoelectron Spectroscopic (XPS) studies demonstrate that the electron density over Si and BO atoms of Q4 species increases with Cs2O content. With charge transfer to tetrahedra, the negative charge accumulates preferentially on Si atoms thus decreasing Si O coulombic interactions, weakening Si O force constants, and shifting the Q3 A1 symmetric stretch vibrational frequencies to lower values (e.g., from ~1100 cm−1 to ~1050 cm−1). The fraction of affected Q3 species increases with alkali content, as does the Q3 peak asymmetry. The Raman shifts of the Q4 species are also affected by increased Cs2O contents.

International audience; A diastereodivergent and enantioselective synthesis of chiral spirocyclohexyl-indolenines with four contiguous stereogenic centers is achieved by a chiral phosphoric acid-catalyzed cycloaddition of 2-susbtituted 3-indolylmethanols with 1,3-dienecarbamates. Modular access to two different diastereoisomers with high enantioselectivities was obtained by careful choice of reaction conditions. Their functional group manipulation provides an efficient access to enantioenriched spirocyclohexyl-indolines and -oxindoles. The origins of this stereocontrol have been identified using DFT calculations, which reveal an unexpected mechanism compared to our previous work dealing with enecarbamates.

This study evaluated the impact of a high loading dose of caspofungin (CAS) on the pharmacokinetics of CAS and the pharmacokinetic-pharmacodynamic (PK-PD) target attainment in patients in intensive care units (ICU). ICU patients requiring CAS treatment were prospectively included to receive a 140-mg loading dose of CAS. Plasma CAS concentrations (0, 2, 3, 5, 7, and 24 h postinfusion) were determined to develop a two-compartmental population PK model. A Monte Carlo simulation was performed and the probabilities of target attainment (PTAs) were computed using previously published MICs. PK-PD targets were ratios of area under the concentration-time curve from 0 to 24 h (AUC0–24h) divided by the MIC (AUC0–24h/MIC) of 250, 450, and 865 and maximal concentration (Cmax) divided by the MIC (Cmax/MIC) of 5, 10, 15, and 20. Among 13 included patients, CAS clearance was 0.98 ± 0.13 liters/h and distribution volumes were V1 = 9.0 ± 1.2 liters and V2 = 11.9 ± 2.9 liters. Observed and simulated CAS AUC0–24h were 79.1 (IQR 55.2; 108.4) and 81.3 (IQR 63.8; 102.3) mg · h/liter during the first 24 h of therapy, which is comparable to values usually observed in ICU patients at day 3 or later. PTAs were >90% for MICs of 0.19 and 0.5 mg/liter, considering AUC/MIC = 250 and Cmax/MIC = 10 as PK-PD targets, respectively. Thus, a high loading dose of CAS (140 mg) increased CAS exposure in the first 24 h of therapy, allowing early achievement of PK-PD targets for most Candida strains. Such a strategy seems to improve treatment efficacy, though further studies are needed to assess the impact on clinical outcomes. (This study has been registered at ClinicalTrials.gov under identifier {"type":"clinical-trial","attrs":{"text":"NCT02413892","term_id":"NCT02413892"}}NCT02413892.)

International audience; The combined Lewis acid catalytic system, generated from molecular iodine and tritylium tetrafluoroborate effectively catalyzed the Friedel−Crafts (FC) arylation of diarylmethyl sulfides providing an efficient access to various unsymmetrical triarylmethanes. The addition of tritylium and iodine created a more active catalytic system to promote the cleavage of sulfidic C-S bonds. Unsymmetrical triarylmethanes 1 represent an important class of organic molecules due to their occurrence in bioactive natural products (such as muchimangin G-J, 1f melanervin 1k) and pharmaceuticals 1g-i (Figure 1).

The use of long-term taurolidine locks (LTTL) seems to be effective in preventing catheter-related blood stream infections (CRBSI), especially in patients on home parenteral nutrition (HPN). This work targets the cost-effectiveness of LTTL in a cohort of adult HPN patients.A monocentric mirror-image design study was conducted in our referral centre among long-term HPN patients experiencing recurrent CRBSI. From 7th January 2011, LTTL were started after the third CRBSI episode within 12 months. CRBSI data was prospectively collected until 7th January 2013, in the same way as it had retrospectively been done before initiating LTTL. A cost-effective analysis was conducted to estimate the incremental costs and effects on CRBSI with LTTL. The efficacy of LTTL on CRBSI rate was assessed over 1000 days of catheter use.A total of 31,100 catheter days were analysed in 37 patients (median [interquartile range (IQR)]) aged 58 [42-68] years. The mean ± SD proven CRBSI rate was 3.18 ± 3.51 per 1000 catheter days before the introduction of LTTL and 0.39 ± 1.50 per 1000 catheter days after its introduction (p 0.0001). Considering both proven and probable CRBSI requiring hospital management, LTTL reduced by (mean [bootstrap CI 95%]) -2.63 [-3.26 to -2.06] infections per patient (from 2.89 [2.31 to 3.49] before to 0.26 [0.13 to 0.41] after) as well as incremental costs by -7 258 [-10 450 to -4 016] € (from 11 176 [8 004 to 14 968] € before to 3 918 [2 390 to 5 445] € after).Implementing LTTL to prevent recurrent CRBSI is cost-effective by dramatically decreasing their incidence.

International audience; An efficient enantioselective construction of tetrahydronaphthalene-1,4-diones as well as dihydronaphthalene-1,4-diols via a chiral phosphoric acid catalyzed quinone Diels-Alder reaction with dienecarbamate was reported. The nature of the protected group on diene was key to the success showing a remarkable influence for achieving high enantioselectivity. The divergent "redox" selectivity is controlled by adequate amount of quinones used. Reversible redox switching without erosion of enantioselectivity was possible from individual redox isomers.

International audience; The depolarized Raman spectra can be used as a probe to reveal the presence of non-network formers in oxide glasses. Two spectral responses involving the cations are observed below 400 cm−1 in more than 30 compositions of binary and ternary aluminosilicates. One of the two bands arises solely from cations close to non-bridging oxygen providing thereby a simple test for qualifying the polymerization state of the glass. The second feature involves all cations whatever their role in the glass and is found to be twofold: one contribution arises from cations charge compensating (AlO4)− tetrahedra and the other one from network modifier cations. These results confirm the net vibrational contrast of cations depending on their structural surrounding.

Phosphorylation of p62/SQSTM1 (p62) on Serine 349 (P-Ser349 p62) as well as proteasome dysfunction have been shown to activate the cell protective Keap1/Nrf2 pathway. We showed previously that BAY 11-7085-induced human synovial fibroblast cell death includes autophagy and p62 downregulation. In this work, we have studied expression of P-Ser349 p62 in human synovial fibroblasts. Results showed that P-Ser349 p62 was not detected in synovial cell extracts unless cells were cultured in the presence of proteasome inhibitor (MG132). MG132 revealed P-Ser349 p62 turnover, that was further increased by concomitant autophagy inhibition and markedly enhanced in serum starved cells. Starvation sensitized synovial fibroblasts to BAY 11-7085 while MG132 protected both non-starved and starved cells from BAY 11-7085-induced cell death. Lentivirus mediated overexpression of phosphorylation-mimetic p62 mutant S349E markedly protected synovial fibroblasts from BAY 11-7085. Inhibitor of Keap1-P-S349 p62 interaction, K67, had synergistic effect with MG132. Starvation increased p62 molecular weight, that was reversed by serum and bovine serum albumin re-feeding. Furthermore, starvation markedly induced RAD23B. Increased endo-β-N-acetylglucosaminidase (ENGase) turnover was detected in starved synovial fibroblasts. PNGase F treatment produced faster migration p62 form in human synovial tissue extracts but starvation-like p62 form of higher molecular weight in synovial cell extracts. Co-transfection of NGLY1, with p62 or p62 mutants S349A and S349E markedly stabilized p62 expressions in HEK293 cells. Tunicamycin upregulated p62 and protected synovial fibroblasts from BAY 11-7085-induced cell death. These results showed that P-Ser349 p62 has pro-survival role in human synovial fibroblasts and that de-glycosylation events are involved in p62 turnover.

We present the first Li K-edge XANES study of a varied suite of lithium silicate (LS) and lithium alkaline-earth silicate (LMS) glasses. The LS series contains three glasses with compositions LS4 (20 Li2O–80 SiO2), LS2 (33 Li2O–67 SiO2) and LS1.5 (40 Li2O–60 SiO2) and the LMS series is comprised of four glasses of compositions 20 Li2O–20 M2O–60 SiO2 where M = Mg, Ca, Sr and Ba. The spectra were compared to those of known salts and minerals, particularly to lithium metasilicate (Li2SiO3) and lithium carbonate (Li2CO3). Crystalline lithium metasilicate has a sharp, strong intensity absorption edge whereas the lithium silicate glasses all have a weak intensity edge feature, similar to that of lithium carbonate (Li2CO3). The intensity of the edge is governed by the existence of a 2p electron and can be correlated with the ionicity of the Li O bond. Therefore, the bonding environment in LS glasses differs considerably from their crystalline counterparts. The area of the absorption edge peak increases with the lithium content of the LS glasses. As for the LMS glasses the edge peak changes drastically depending on the alkaline-earth present. The peak area of the LMS glasses decreases with increasing charge density (Z/r2) from barium to magnesium. The area of the absorption edge peak in the LS glasses is larger than that of the LMS glasses. Thus, the addition of alkaline-earth elements to lithium silicate glasses modifies the glass network differently depending on the specific element, which in turn creates an altered lithium bonding environment as evidenced by their Li K-edge XANES spectra.

A highly enantio- and diastereoselective formal (4+3) cycloaddition of 1,3-diene-1-carbamates with 3-indolylmethanols in the presence of a chiral phosphoric acid catalyst is reported. The approach described herein provides efficient access to 6-aminotetrahydrocyclohepta[b]indoles in good yields with mostly complete diastereoselectivity and excellent levels of enantioselectivity (>98:2 dr and up to 98 % ee). Mild reaction conditions, facile scale-up, and versatile derivatization highlight the practicality of this methodology. A mechanistic study suggests that cycloaddition occurs in a stepwise fashion, after the formation of an ion pair between the chiral catalytic phosphate and the intermediate carbocation.

Background: InformationTumor stroma remodeling is a key feature of malignant tumors and can promote cancer progression. Laminins are major constituents of basement membranes that physically separate the epithelium from the underlying stroma. Results: By employing mouse models expressing high and low levels of the laminin 1 chain (LM1), we highlighted its implication in a tumor-stroma crosstalk, thus leading to increased colon tumor incidence, angiogenesis and tumor growth. The underlying mechanism involves attraction of carcinoma-associated fibroblasts by LM1, VEGFA expression triggered by the complex integrin 21-CXCR4 and binding of VEGFA to LM-111, which in turn promotes angiogenesis, tumor cell survival and proliferation. A gene signature comprising LAMA1, ITGB1, ITGA2, CXCR4 and VEGFA has negative predictive value in colon cancer. Conclusions: Together, we have identified VEGFA, CXCR4 and 21 integrin downstream of LM1 in colon cancer as of bad prognostic value for patient survival. Significance: This information opens novel opportunities for diagnosis and treatment of colon cancer.

Raman spectra at 298 K of the SiO4 symmetric stretch region (800–1200 cm−1) for low alkali (M) silicate glasses (5 and 10 mol% M2O, for M = Cs, K) yield intense well-resolved Q3 peaks at ~1100 cm−1 with mostly Lorentzian character, in contrast to previous Gaussian fits for silicate glasses. The spectra of 5 mol% Na and Li glasses show an additional Q3 peak. It results from close approach of alkalis (M) to bridging oxygen (BO) which splits the Q3 band into two peaks. All linewidths (FWHM) of fitted Q1, Q2 and Q3 species peaks are similar (~35–55 cm−1) at 298 K for all the above glasses. The Q3 species FWHM of 5 and 10 mol% Cs2O silicate glasses show a T dependence similar to those of crystal silicate spectra: both increase by 35–45 cm−1 from 298 K to 1200 K. The T dependence of the FWHM of these Lorentzian dominated peaks are consistent with theory. The more complex spectra of the 30 mol% K2O and 50 mol% Na2O glass spectra are then readily fit with two or three Q2 or Q3 peaks, constraining the % Lorentzian character of all peaks from the fit to the resolved peak in those spectra. The 50 mol% Na2O spectrum shows that Q3 > Q1, indicating ~4.5 mol% free oxygen in the glass, a value in good agreement with previous 29Si NMR and O 1s XPS results. Lorentzian/Gaussian lineshapes now need to be considered for many more silicate glass/melt Raman spectra.

International audience; Dirhodium(II)-catalyzed nitrene transfers have been used to prepare a novel synthetic platform bearing the triamino moiety present in pactamycin, jogyamycin and cranomycin. Catalytic intramolecular C(sp3)–H amination and alkene aziridination reactions, the latter followed by a nucleophilic aziridine ring opening, are the key steps of this strategy.

Ascertaining elements oxidation state, coordination, and bonding environment provides an understanding of the parameters controlling the elements structural behavior, and in turn, the possibility of developing novel applications. Cerium doped materials are widely used for technological applications, mainly because of the strong UV absorption and the characteristic short decay time of the intense emission in the UV–Vis ranges. In this study, Ce speciation in different glass systems has been evaluated and related to variations in optical and physical properties, as well as to variations in glass network connectivity. Data obtained from X-ray Absorption Spectroscopy, Raman, and Photoluminescence Spectroscopy are presented. By using a multispectroscopy approach, we determined the Ce3+/Ce4+ redox ratio in silicate glasses/melts and the influence of the two different Ce species on structure and properties. Our study indicates that reduced Ce species are favored with an increase in the degree of melt polymerization but hindered in alkaline-rich bulk chemistries. Consequently, the oxygen ion activity (here represented by the theoretical optical basicity) might be used to estimate the Ce redox ratio's evolution. On the contrary, we show that glass luminescence properties cannot be tailored by merely adjusting the bulk chemistry. Furthermore, we propose an alternative approach for detecting and quantifying the different Ce species in glasses, and we show the occurrence of a non-symmetric Raman vibration at ~880 cm−1, whose intensity is well correlated with the Ce3+/Ce4+ redox ratio. We assign this band to the interaction of the SiO4 tetrahedra with Ce4+-O polyhedral. Thus, cerium preferentially links to the silicate network, and we examined the possibility of using Raman spectroscopy to detect and quantify the different Ce species.

The aim of our study is to investigate the structural effects of the substitution of aluminum by boron in lime alumino-borate glasses. In this case a competition between two network formers can be observed. It was proven that aluminum can be in four, five and six-fold coordination in calcium aluminate and aluminosilicate glasses, whereas boron can be in three and four-fold coordination in borate and borosilicate glasses. To understand what happens when boron replaces aluminum, different glasses were made starting with Ca-aluminate glass, C12Al14O33, i.e. “C12A7” in cement nomenclature, and then progressively substituting aluminum by boron until B fully replaces Al. Raman, 11B NMR and 27Al NMR spectroscopies were used to investigate the structure of these glasses at medium and short range order respectively. Density, DSC measurements were also done in order to characterize properties at a macroscopic scale. NMR and Raman spectra show that aluminum in Ca-aluminate glass, C12A7, is in four-fold coordination, more precisely in T3 and T4 species (Tn indicates aluminum in tetrahedral sites with n Bridging Oxygens). Whereas, when boron replaces aluminum, BO3 are the main species formed in good agreement with the two spectroscopic methods. These triangular units break the tetrahedral network already formed by AlO4− leading to an important drop of Tg. As the concentration of boron increases, NBOs are formed to create BO4 tetrahedral units, with the presence of calcium acting as a charge compensator. These tetrahedral structures start to increase the polymerization of the network. Glass transition temperature, Tg, continues to decrease but with a slower decline. In this study, we will present all these results and discuss the influence of the structure of the network on the macroscopic parameters.

The Adam and Gibbs theory depicts the viscous flow of silicate melts as governed by the cooperative re-arrangement of molecular sub-systems. Considering that such subsystems involve the silicate Q n units ( n = number of bridging oxygens), this study presents a model that links the Q n unit fractions to the melt configurational entropy at the glass transition temperature T g , S conf (T g ) , and finally, to its viscosity η . With 13 adjustable parameters, the model reproduces η and T g of melts in the Na 2 O-K 2 O-SiO 2 system (60 ≤ [SiO 2 ] ≤ 100 mol%) with 1σ standard deviations of 0.18 log unit and 10.6°, respectively. The model helps understanding the links between the melt chemical composition, structure, S conf and η . For instance, small compositional changes in highly polymerized melts generate important changes in their S conf (T g ) because of an excess of entropy generated by mixing Si between Q 4 and Q 3 units. Changing the melt silica concentration affects the Q n unit distribution, this resulting in non-linear changes in the topological contribution to S conf (T g ) . The model also indicates that, at [SiO 2 ] ≥ 60 mol%, the mixed alkali effect has negligible impact on the silicate glass Q n unit distribution, as corroborated by Raman spectroscopy data on mixed Na-K tri- and tetrasilicate glasses. Such model may be critical to link the melt structure to its physical and thermodynamic properties, but its refinement requires further high-quality quantitative structural data on silicate and aluminosilicate melts.

A sewage sludge composition is simulated by adding CaO and P 2 O 5 to a basalt in order to produce glasses with low viscosity at high temperatures. Raman spectroscopy shows the presence of Q 0 and Q 2 silicate groups. The increase of Vickers microhardness is related to an nucleation of crystalline phases (magnetite, diopside, akermanite) that crystallize upon thermal treatments. Raman spectroscopy has given information on the presence of Q 0 and Q 2 silicate groups. These new glass-ceramics may be used as starting compositions for the immobilization of other industrial wastes.

International audience; A new catalytic enantioselective tandem deoxygenation/aza‐Diels‐Alder reaction of nitrones with enecarbamates was serendipitously discovered in the presence of chiral copper(II) diphosphate complexes. This process affords a wide range of 4‐aminotetrahydroquinolines in respectable yields under mild conditions with good to excellent ee values.

International audience; Rare-earth-doped oxide nanoparticles in the core of silica optical fibers are becoming well studied as they yield enhanced and tailorable spectroscopic and optical properties. In this paper, the evolution of particle morphology , induced by the drawing step, is studied. Indeed, during the fiber draw process, the glass flows and particles can elongate and even break-up into smaller particles through Rayleigh-Plateau instabilities. The shape of elongated particles is related to the composition as it depends on the viscosity ratio between the particle and the matrix. Moreover, a lower drawing temperature enhances the break-up phenomenon. These observations offer new possibilities for the control of the size and the shape of particles, hence performance of active optical fibers.

Chiral phosphoric acid catalyzed the formal [4+2]-cycloaddition of 2-benzothiazolimines with enecarbamates to provide benzothiazolopyrimidines with up to 99% yield and >99% ee., A highly efficient catalytic enantioselective [4+2] cycloaddition was developed between 2-benzothiazolimines and enecarbamates. A wide range of benzothiazolopyrimidines bearing three contiguous stereogenic centers was obtained in high to excellent yields and with excellent diastereo- and enantioselectivities (d.r. > 98 : 2 and up to >99% ee). Furthermore, this chiral phosphoric acid-catalyzed strategy was scalable and enabled access to a new class of optically pure Lewis base isothiourea derivatives.

The analysis of iron, manganese and antimony in silicate glass is of great interest in chemistry, materials science, earth sciences and archaeological sciences. Yet, conclusions from different fields appear to be contradictory and many questions about redox reactions in glass remain. The purpose of this study is thus to discuss whether and how these multivalent elements interact in glass. Soda-lime silicate melts containing iron along with manganese and/or antimony have been analysed at different high temperatures under argon atmosphere. Using in-situ XANES at the Fe K-edge, redox thermodynamics, kinetics and diffusivities have been assessed for the different compositions. The data obtained show that antimony is more efficient at oxidising iron compared to manganese at all temperatures. The oxidising power trend would thus be Sb > Sb + Mn > Mn. Furthermore, hypotheses on the formation of Fe-Mn complexes are also reported in glasses with stoichiometric proportions of iron and manganese. Based on the determination of redox diffusivities, it appears that presence of other multivalent elements does not significantly affect the iron redox mechanisms and that diffusivity is essentially controlled by the mobility of calcium.

In a recent publication in Nature , Tambar and coworkers have reported a Lewis-acid-assisted Bronsted-acid-catalyzed asymmetric hetero-ene reaction that proceeds from internal alkenes with excellent enantio-, regio-, and E -olefin selectivity. Key to the success is the use of a sulfurimide enophile. Derivatization of the ene products affords various allylic compounds.

The composition of sewage sludge from urban wastewater treatment plants is simulated using P-doped basalts. Electron microscopy analyses show that the solubility of P in the basaltic melt is limited by the formation of a liquid-liquid immiscibility in the form of an aluminosilicate phase and a Ca-Mg-Fe-rich phosphate phase. The rheological behavior of these compositions is influenced by both phase separation and nanocrystallization. Upon a thermal treatment, the glasses will crystallize into a mixture of inosilicates and spinel-like phases at low P contents and into Ca-Mg-Fe phosphate at high P contents. Hardness measurements yield values between 5.41 and 7.66 GPa, inside the range of commercial glasses and glass-ceramics. Leaching affects mainly unstable Mg2+-PO43- complexes.

We describe a simple and effective strategy to couple gold nanorods (GNRs) into end to end dimers and freeze the assembly in water. The assembly is initiated using cysteine and driven by hydrogen bonding between two cysteine. We show that the aging of GNRs samples impacts both the assembly kinetics and the final yield of GNRs dimers. The addition of an appropriate amount of silver nitrate induces the immediate termination of GNRs dimerization and stabilizes the small aggregates in solution for at least 24 h.

A copper-promoted three-component synthesis of 2-aminobenzimidazoles (1) or of 2-aminoquinazolines (2) involving cyanamides, arylboronic acids, and amines has been developed. The operationally simple oxidative process, performed in the presence of K2CO3, a catalytic amount of CuCl2·2H2O, 2,2'-bipyridine, and an O2 atmosphere (1 atm), allows the rapid assembly of either benzimidazoles or quinazolines starting from aryl- or benzyl-substituted cyanamides, respectively. In this process, the copper promotes the formation of three bonds, two C-N bonds, and an additional bond resulting from C-H functionalization event.

International audience; The siliceous iron ore deposits in the NW part of Iran (Takab region) are hosted within para-metamorphic rocks, and are attributed to Late Proterozoic age. They comprise massive, banded, nodular and disseminated ore types, which are mainly composed of magnetite. Magnetite contains traces of Al. It is variously hematitized. Hematite show higher Al, Si and Ca contents than the magnetite. The iron oxides contain inclusions of zircons, apatite, uraninite, Mn-carbonate and euhedral monazite. Later hydrothermal solutions precipitated goethite surrounding the magnetitehematite-maghemite grains and replacing hematite. Barite occurs in fractures of iron oxides, Mn-Ba-Pb oxi-hydroxides and scheelite occur interstitial to iron oxides. The ∂ 56 Fe values observed for magnetite decrease from disseminated to nodular iron ore (averages: +1.3, +0.4 and-0.4 ‰ (± 0.2 ‰), respectively). Iron isotopes of hematite in disseminated & layered ore show higher ∂ 56 Fe values than those of magnetite, in the range of +2 to +4 ‰ (± 0.2 ‰).

Understanding the links between chemical composition, nano-structure and the dynamic properties of silicate melts and glasses is fundamental to both Earth and Materials Sciences. Central to this is whether the distribution of mobile metallic ions is random or not. In silicate systems, such as window glass, it is well-established that the short-range structure is not random but metal ions cluster, forming percolation channels through a partly broken network of corner-sharing SiO4 tetrahedra. In alumino-silicate glasses and melts, extensively used in industry and representing most of the Earth magmas, metal ions compensate the electrical charge deficit of AlO4− tetrahedra, but until now clustering has not been confirmed. Here we report how major changes in melt viscosity, together with glass Raman and Nuclear Magnetic Resonance measurements and Molecular Dynamics simulations, demonstrate that metal ions nano-segregate into percolation channels, making this a universal phenomenon of oxide glasses and melts. Furthermore, we can explain how, in both single and mixed alkali compositions, metal ion clustering and percolation radically affect melt mobility, central to understanding industrial and geological processes.

We present a rapid and efficient method for the detection of related transcripts with different expression levels. This approach combines the rapid amplification of cDNA ends (RACE) method with a cDNA subtractive technique. The strategy is based on successive subtractions of prevalent isoforms resulting in enrichment of less expressed transcripts. For each subtraction, a biotinylated primer specific for the prevalent isoform is hybridized on the total cDNA and the hybrid is retained on a streptavidin affinity column. The unbound cDNA serves as a template for subsequent isoform identification. To illustrate its application we describe the isolation of three new actin cDNA isoforms in the freshwater planarian Dugesia (S) polychroa.

The atomic-scale structure of aerodynamically levitated and laser-heated liquid tricalcium aluminate (${\mathrm{Ca}}_{3}{\mathrm{Al}}_{2}{\mathrm{O}}_{6}$) was measured at 2073(30) K by using the method of neutron diffraction with Ca isotope substitution (NDIS). The results enable the detailed resolution of the local coordination environment around calcium and aluminum atoms, including the direct determination of the liquid partial structure factor, ${S}_{\mathrm{CaCa}}(Q)$, and partial pair distribution function, ${g}_{\mathrm{CaCa}}(r)$. Molecular dynamics (MD) simulation and reverse Monte Carlo (RMC) refinement methods were employed to obtain a detailed atomistic model of the liquid structure. The composition ${\mathrm{Ca}}_{3}{\mathrm{Al}}_{2}{\mathrm{O}}_{6}$ lies at the CaO-rich limit of the CaO:${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ glass-forming system. Our results show that, although significantly depolymerized, liquid ${\mathrm{Ca}}_{3}{\mathrm{Al}}_{2}{\mathrm{O}}_{6}$ is largely composed of ${\mathrm{AlO}}_{4}$ tetrahedra forming an infinite network with a slightly higher fraction of bridging oxygen atoms than expected for the composition. Calcium-centered polyhedra exhibit a wide distribution of four- to sevenfold coordinated sites, with higher coordinated calcium preferentially bonding to bridging oxygens. Analysis of the MD configuration reveals the presence of $\ensuremath{\sim}10\phantom{\rule{0.16em}{0ex}}%$ unconnected ${\mathrm{AlO}}_{4}$ monomers and ${\mathrm{Al}}_{2}{\mathrm{O}}_{7}$ dimers in the liquid. As the CaO concentration increases, the number of these isolated units increases, such that the upper value for the glass-forming composition of CaO:${\mathrm{Al}}_{2}{\mathrm{O}}_{3}$ liquids could be described in terms of a percolation threshold at which the glass can no longer support the formation of an infinitely connected ${\mathrm{AlO}}_{4}$ network.

Optical, structural properties and redox were studied for Ce-bearing silicate and aluminosilicate glasses and Ce-activated silica (SiO2) fiber preforms, by X-ray Absorption, Raman and Photoluminescence Spectroscopy. The introduction of Al2O3 in Ce-bearing silicate glass strongly stabilizes reduced species in agreement with the optical basicity concept and additionally induces modifications in the Ce3 + surrounding. In Al-free silica preforms, depending on the collapsing conditions, the Ce3 +/ΣCe ratio has the highest variability (Ce3 +/ΣCe = 0.7–0.85 ± 0.07), whereas in Al-bearing fiber preforms, Al codoping induces a strong stabilization of Ce3 + species, despite the collapsing atmosphere. Al presence induces modifications on Ce local environment, and thus variations of the distance between Ce3 + and its ligands, and/or to variations of the covalency of the bonds. Absorption bands in the UV region, ascribed to Charge-transfer (CT) bands, in our samples, occur only for low amount of Ce4 + (Ce3 +/ΣCe > 0.85 ± 0.07). Indeed, in silicate and aluminosilicate glasses the higher amount of Ce4 + does not give rise to UV absorption bands ascribed to CT processes, whereas, in fiber preforms, Ce3 + species can induce the trapping of hole centers, and enhance the photoluminescence efficiency. More generally, these results enhance our understanding of REE structural and chemical roles in amorphous materials and increase our knowledge for technical applications.

In this paper, we propose a simple method to embed transparent reactive materials in a microfluidic cell, and to observe in situ the dissolution of the material. As an example, we show how to obtain the dissolution rate of a calcite window of optical quality, dissolved in water and hydrochloric acid (HCl). These fluids circulate at controlled flowrates in a channel which is obtained by xurography: double sided tape is cut out with a cutter plotter and placed between the calcite window and a non-reactive support. While the calcite window reacts in contact with the acid, its topography is measured in situ every 10 s using an interference microscope, with a pixel resolution of 4.9 μm and a vertical resolution of 50 nm. In order to avoid inlet influence on the reaction, a thin layer of photoresist is added on the calcite surface at the inlet and outlet. This layer is also used as a non reactive reference surface.

The controlled assembly of anisotropic plasmonic nanoparticles (NPs) into highly SERS-active substrates remains particularly challenging for the production of long-term stable NP assemblies in suspension. In this work, we report a simple and efficient strategy to assemble gold nanorods (AuNRs) into dimers. The pH-dependent assembly was triggered using the bifunctional molecular linker BPE (1,2-bis(4-pyridyl)ethylene) and quenched with silver nitrate. The resulting AuNR dimers were encapsulated in mesoporous silica shell and proved to be stable in water for at least 5 months. Taking advantage of the large Raman scattering cross-section of the linker BPE, we conducted a detailed study of the enhancement ability of these NR dimers using solution-based surface enhanced Raman scattering (SERS). Both experimental (SERS) and theoretical (discrete dipole approximation) studies of the near-field characteristics revealed a two-orders of magnitude increase of the SERS enhancement factor for the dimers as compared to isolated AuNRs. Besides thermal and colloidal stability, mesoporous silica coating of AuNRs imparts other notable advantages due to its porosity and biocompatibility, which make these core-shell plasmonic platforms promising for future bio-applications.

The combination of neutron diffraction with aerodynamic levitation and laser heating, pioneered by Neville Greaves and co-workers about 15years ago, is an important tool for studying the structure of liquid melts. Since the first work on liquid Al2O3 published in 2001, the technique has been largely improved and experiments are now routinely performed at neutron sources, providing interesting structural information on various materials.In this paper, the structure of glass-forming compounds in the system CaO-Al2O3-SiO2 was measured by applying neutron diffraction with aerodynamic levitation. Results obtained in the liquid state above the melting point and from the glass at room temperatures are presented. Various compositions were studied by increasing the silica content and by changing the ratio CaO/Al2O3. As observed using other methods, the main structural changes relate to modification of the Al-O short range order.

To characterize in rice rats: (a) periodontitis (PD) progress with feeding of standard laboratory rat chow (STD) during ages 4-80 weeks; and (b) PD progress with feeding of a high sucrose-casein (H-SC) diet during young adulthood.One group (N=12) was euthanized at age 4 weeks (Baseline). Four groups (N=8-16) consumed a STD diet from baseline and were necropsied at ages 22, 30, 52, and 80 weeks. Three groups (N=10-16) consumed an H-SC diet from baseline. Two were necropsied at ages 22 and 30 weeks, respectively. The third switched to the STD diet at age 22 weeks and was necropsied at age 30 weeks. All mandibles/maxillae were assessed by histometry for degree of periodontal inflammation (PD Score), alveolar crest height (ACH, mm), and horizontal alveolar bone height (hABH, mmIn STD diet rats aged ≥30 weeks, all endpoints were worse (P0.05) than at Baseline. In H-SC diet rats aged ≥22 weeks, all endpoints were worse than at Baseline (P0.05). At age 22 weeks, all endpoints were worse in the H-SC group than in the STD group (P0.05). By age 30 weeks, the STD and H-SC groups did not differ.1) STD diet fed rice rats develop moderate/severe PD by age 30 weeks; 2) an H-SC diet accelerates moderate/severe PD development; and 3) switching to a STD diet does not halt/reverse PD that was accelerated by an H-SC diet. These data further clarify use of the rice rat as a PD model.

Noble gases are ideal probes to study the structure of silicate glasses and melts as the modifications of the silicate network induced by the incorporation of noble gases are negligible. In addition, there are systematic variations in noble gas atomic radii and several noble gas isotopes with which the influence of the network itself on diffusion may be investigated. Noble gases are therefore ideally suited to constrain the time scales of magma degassing and cooling. In order to document noble gas diffusion behavior in silicate glass, we measured the diffusivities of three noble gases (4He, 20Ne and 40Ar) and the isotopic diffusivities of two Ar isotopes (36Ar and 40Ar) in two synthetic basaltic glasses (G1 and G2; 20Ne and 36Ar were only measured in sample G1). These new diffusion results are used to re-interpret time scales of the acquisition of fractionated atmospheric noble gas signatures in pumices. The noble gas bearing glasses were synthesized by exposing the liquids to high noble gas partial pressures at high temperature and pressure (1750–1770 K and 1.2 GPa) in a piston-cylinder apparatus. Diffusivities were measured by step heating the glasses between 423 and 1198 K and measuring the fraction of gas released at each temperature step by noble gas mass spectrometry. In addition we measured the viscosity of G1 between 996 and 1072 K in order to determine the precise glass transition temperature and to estimate network relaxation time scales. The results indicate that, to a first order, that the smaller the size of the diffusing atom, the greater its diffusivity at a given temperature: D(He) > D(Ne) > D(Ar) at constant T. Significantly, the diffusivities of the noble gases in the glasses investigated do not display simple Arrhenian behavior: there are well-defined departures from Arrhenian behavior which occur at lower temperatures for He than for Ne or Ar. We propose that the non-Arrhenian behavior of noble gases can be explained by structural modifications of the silicate network itself as the glass transition temperature is approached: as the available free volume (available site for diffusive jumps) is modified, noble gas diffusion is no longer solely temperature-activated but also becomes sensitive to the kinetics of network rearrangements. The non-Arrhenian behavior of noble gas diffusion close to Tg is well described by a modified Vogel–Tammann–Fulcher (VTF) equation: D a 2 = A 1 a 2 ∗ exp - B 1 R ( T - T 2 ) - C RT where D is the diffusion coefficient, a the diffusion domain size (taken to be the size of the sample), A1 and C are respectively equivalent to the pre-exponential factor and to the activation energy (Ea in J mol−1) of the classical Arrhenius equation, B1 can be interpreted as a “pseudo-activation energy” that reflects the influence of the silicate network relaxation, T2 is the temperature where the diffusion regime switches from Arrhenian to non-Arrhenian, and R is the gas constant (=8.314 J K−1 mol−1). Finally, our step heating diffusion experiments suggest that at T close to Tg, noble gas isotopes may suffer kinetic fractionation at a degree larger than that predicted by Graham’s law. In the case of 40Ar and 36Ar, the traditional assumption based on Graham’s law is that the ratio D40Ar/D36Ar should be equal to 0.95 (the square root of the ratio of the mass of 36Ar over the mass of 40Ar). In our experiment with glass G1, D40Ar/D36Ar rapidly decreased with decreasing temperature, from near unity (0.98 ± 0.14) at T > 1040 K to 0.76 when close to Tg (T = 1003 K). Replicate experiments are needed to confirm the strong kinetic fractionation of heavy noble gases close to the transition temperature.

Nuclear reactions initiated by laser-accelerated particle beams are a promising new approach to many applications, from medical radioisotopes to aneutronic energy production. We present results demonstrating the occurrence of secondary nuclear reactions, initiated by the primary nuclear reaction products, using multicomponent targets composed of either natural boron (B) or natural boron nitride (BN). The primary proton-boron reaction (p + 11B → 3 α + 8.7 MeV), is one of the most attractive aneutronic fusion reaction. We report radioactive decay signatures in targets irradiated at the Elfie laser facility by laser-accelerated particle beams which we interpret as due to secondary reactions induced by alpha (α) particles produced in the primary reactions. Use of a second nanosecond laser beam, adequately synchronized with the short laser pulse to produce a plasma target, further enhanced the reaction rates. High rates and chains of reactions are essential for most applications.

Raman spectroscopy can measure water concentrations of hydrous silicate glasses with several advantages such as: (1) high-spatial resolution of 1–2 μm2; (2) non-destructive character; and (3) easy access, without any specific sample preparation or mounting techniques. The latter reasons render Raman highly suitable for studying natural products, such as volcanic pumice and scoriae fragments. Two spectral regions can be distinguished in Raman spectra of hydrated silicate glasses: a low-wavenumber region (15–1500 cm−1), which corresponds to vibrations of the silicate network, and a high-wavenumber region (3100–3750 cm−1), corresponding to the OH stretching vibrations of H2O molecules and OH groups. Behrens et al. (2006) have published empirical equations relating the area ratio between these two regions and the water content. However, the proposed internal calibrations depend on chemical composition of the glasses. In this paper, we reinvestigated the previous procedures to improve the background subtraction. Our results allow us to present a more general and linear calibration. Water concentrations up to 13 wt% can be measured for a broad range of natural silicate melts, from basalts to rhyolite (40 up to 80 wt% SiO2), using a single calibration curve with an absolute error of 0.2 wt%.

Diabetic eye disease is one of the major complications affecting adults with diabetes in the United States.1 National trends in adult diabetes mellitus indicate that its prevalence has reached epidemic proportions over the last two decades.2, 3 Similar trends have also been observed in the adolescent population.4-8 As the prevalence of adult and adolescent diabetes increases, these patients can expect to bear greater health care and financial burdens due to diabetes. These trends necessitate the investigation of early diabetes related pathology. The early diagnosis of pathology in the eyes of adults and adolescents with diabetes will improve our monitoring of diabetes-related complications and ultimately improve patient care and outcomes. Current clinical techniques for diagnosing and monitoring complications in the eye focus largely on the presence of visible vascular related lesions or changes in visual acuity. Recent diagnostic advances have shown that diabetic eye disease can be characterized by both morphological and physiological changes in retinal structures prior to visible lesions and loss of visual acuity.9-11 Using noninvasive retinal electrophysiology, there is considerable evidence that the neural function of the retina can be affected early in diabetes.12-16 The multifocal electroretinogram (mfERG) is an objective measure that allows for the assessment of small discrete regions of neural retinal function. Several studies have shown significant mfERG response delays in small patches of the retina even in the absence of co-localized vascular lesions.9, 15, 16 These local delays have been shown to be indicative of future vascular lesions in the corresponding region.9, 16, 17 Optical coherence tomography (OCT) is an objective measure of retinal structure that has been an effective tool for detecting structural changes in the diabetic retina. OCT allows for cross-sectional analysis of retinal thickness. Studies have shown that retinal thickness can be affected in the absence of retinal vascular lesions.14, 18, 19 Digital imaging and analysis of the retinal vasculature around the optic disk have been used to assess vascular changes in the eyes of adults. Abnormalities in the diameter of these blood vessels have been shown to be associated with major diabetes-related complications throughout the body.20-23 The present study is the first to look at the retinal thickness in adolescents with type 1 diabetes as well as retinal function and retinal vascular caliber. While adolescents with type 1 and type 2 diabetes are both challenged with the task of managing their blood sugar levels in order to minimize the risk of future pathology, the pathologies preceding and/or contributing to the onset of hyperglycemia in adolescents with type 1 diabetes are very different from those with type 2 diabetes mellitus. Those with type 2 diabetes tend to present with higher body mass index (BMI), higher blood pressure, hyperlipidemia and a history of hyperinsulinemia. The purpose of the present study is to examine the existence and frequency of functional and structural retinal abnormalities in adolescents with type 1 diabetes. We also present some previously published data on adolescents with type 2 diabetes so that we can compare the frequency of retinal abnormalities between the two diabetic groups.14 We find that functional and structural abnormalities in the retina can be documented very early in both type 1 and type 2 diabetes and that adolescents with type 2 diabetes present with more abnormalities.

Aluminate glasses are important materials from a fundamental structural point of view because Al is the only network former. They present also a technological interest because of their good IR transmission and ultralow optical losses. Aluminum in glasses of the system MO–Al2O3 (M = Ca, Sr, Ba) can have different coordination numbers, essentially 4 and 6, as a function of the MO/Al2O3 ratio. Using Raman spectroscopy and high field 27Al NMR spectroscopy, we have determined the structure of aluminum network as a function of MO/Al2O3 ratio with M corresponds to different alkaline–earth cations. Al is essentially in four-fold coordination with different amounts for Al2O3 between 50 and 75% but varies between Q2 and Q4 species as a function of MO/Al2O3 ratio where Q is tetrahedral species and n the number of bridging oxygen.

Background The aim of this preliminary study is to characterize by 1H high-resolution magic angle spinning NMR spectroscopy (HRMAS) the metabolic content of intact biopsy samples obtained from 12 patients suffering from neuroblastoma (NB). Procedure The biochemical NB profile was first compared to normal adrenal medulla. In a second step, the relationship between the tumor metabolic profile and the patients' clinical data was investigated. Results A higher level of creatine, glutamine/glutamate, acetate and glycine characterized NB biopsies while healthy adrenal medulla tissue contained adrenaline and a larger amount of ascorbic acid. Adrenaline, which was undetectable in NB spectra, represented the metabolic signature of normal adrenal medulla. NB from patients younger than 12 months contained a higher level of acetate and lysine. Conversely, higher amounts of glutathione, glutamate, myo-inositol, glycine, serine and ascorbic acid were detected in NB samples belonging to younger children. Glutamine/glutamate, aspartate, creatine, glycine were characteristic of stage I–II NB. Acetate and creatine were characteristic of stage IV NB. Finally, a relatively higher amount of aspartate, succinate, and glutathione was detected in patients alive without active disease after a mean follow-up of 7 years whereas a higher concentration of acetate and taurine was characteristic of patients with worse prognosis. Conclusions Our preliminary results suggest the existence of a complex metabolic reality in NB, probably representative of tumor behavior. However, the real impact of these promising results should be assessed by long-term prospective studies on a larger cohort of patients. Pediatr Blood Cancer. 2010;56:24–34. © 2010 Wiley-Liss, Inc.

abst R act The heat capacities of Sr and Ba metasilicate glasses and of a Mg silicate glass with only 44 mol% SiO2 have been measured between 2 and 300 K with the Quantum Design Physical Property Measurement System. The derived vibrational entropies S298-S0 are 50.90, 61.00, and 36.65 J/(mol⋅K) for Sr0.5Si0.5O1.5, Ba0.5Si0.5O1.5, and Mg0.56Si0.44O1.44 glasses, respectively. Along with available data for Mg- and Ca-bearing glasses, these results indicate a regular variation of the partial molar vibrational entropy of the metal oxide as a function of the ionization potential of the cation. At very low temperatures, however, the excess heat capacity of barium metasilicate glass relative to Debye limiting T 3 law is stronger than expected from such a trend, whereas Mg1.12Si0.88O2.88 is the known glass whose