Over the past 60 years, the diamond anvil cell (DAC) has been developed into a widespread high static pressure device. The adaptation of laboratory and synchrotron analytical techniques to DAC ...enables a detailed exploration in the 100 GPa range. The strain of the anvils under high load explains the 400 GPa limit of the conventional DAC. Here we show a toroidal shape for a diamond anvil tip that enables to extend the DAC use toward the terapascal pressure range. The toroidal-DAC keeps the assets for a complete, reproducible, and accurate characterization of materials, from solids to gases. Raman signal from the diamond anvil or X-ray signal from the rhenium gasket allow measurement of pressure. Here, the equations of state of gold, aluminum, and argon are measured with X-ray diffraction. The data are compared with recent measurements under similar conditions by two other approaches, the double-stage DAC and the dynamic ramp compression.
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•rGO-ZnO1-x nanosheet composites have been successfully in-situ synthesized.•rGO-ZnO1-x shows good response to ppb NO2 illuminated by white light at room temperature.•rGO-ZnO1-x ...exhibits much higher sensitivity, faster response and recovery than ZnO.•Molecular Dynamics and Langmuir adsorption model are used to build the sensing mechanism.
Recently, room-temperature gas sensors have become very attractive due to the fact that they can be operated without heating, and thus simplifying the sensor design, reducing the fabrication cost, decreasing the power consumption and increasing the long-term stability. In this study, we propose a facile one-step hydrothermal method to prepare a composite of reduced graphene (rGO)/oxygen-deficient zinc oxide (ZnO1-x), which exhibits obvious room-temperature gas sensing response. X-ray diffraction, Raman and X-ray photoelectron spectroscopy demonstrate that the rGO@ZnO1-x composite is successfully synthesized and large numbers of dual donor defects, oxygen vacancy and zinc interstitial, are introduced into the composite. Field-emission scanning electron microscopy and transmission electron microscopy results reveal that many nanoscale p-n junctions are in-situ formed between ZnO nanosheets and rGO sheets. UV–vis spectra show that the light absorption of the rGO@ZnO1-x composite is red-shifted and extended to the whole visible light region in comparison. The fraction of rGO in the composites plays an important role in the sensing performance. 2.0% is the optimal proportion to obtain the best sensing properties in terms of sensitivity, response and recovery times. The rGO@ZnO1-x composite exhibits significant responses to ppb-level NO2 with white LED light stimulation at room temperature. The enhanced sensing properties can be attributed to three factors: light activation, synergistic effects between rGO and ZnO1-x, and high concentration in donor defects. Molecular Dynamics (MD) is used to quantitively simulate the adsorption process, and the results show that the incorporation of rGO decreases the adsorption energy of NO2. It means that more NO2 species would adsorb on the rGO@ZnO1-x composites, which greatly improves the sensitivity. A new gas sensing mechanism based on the MD calculated results and Langmuir adsorption model is used to explain the reason that the rGO@ZnO1-x composites have a much faster response and recovery process. In addition, the rGO@ZnO1-x sensor shows a weaker response to other interference gases.
•We have evaluated three LC/HRMS methods for their coverage of human serum metabolome.•The three platforms appeared complementary (less than 12% of common annotations).•HILIC column ensured the ...greatest metabolome coverage in the negative ionization mode.•PFPP column ensured the greatest metabolome coverage in the positive ionization mode.•266 metabolites were identified in serum, and 59 are reported for the first time.
This work aims at evaluating the relevance and versatility of liquid chromatography coupled to high resolution mass spectrometry (LC/HRMS) for performing a qualitative and comprehensive study of the human serum metabolome. To this end, three different chromatographic systems based on a reversed phase (RP), hydrophilic interaction chromatography (HILIC) and a pentafluorophenylpropyl (PFPP) stationary phase were used, with detection in both positive and negative electrospray modes. LC/HRMS platforms were first assessed for their ability to detect, retain and separate 657 metabolite standards representative of the chemical families occurring in biological fluids. More than 75% were efficiently retained in either one LC-condition and less than 5% were exclusively retained by the RP column. These three LC/HRMS systems were then evaluated for their coverage of serum metabolome. The combination of RP, HILIC and PFPP based LC/HRMS methods resulted in the annotation of about 1328 features in the negative ionization mode, and 1358 in the positive ionization mode on the basis of their accurate mass and precise retention time in at least one chromatographic condition. Less than 12% of these annotations were shared by the three LC systems, which highlights their complementarity. HILIC column ensured the greatest metabolome coverage in the negative ionization mode, whereas PFPP column was the most effective in the positive ionization mode. Altogether, 192 annotations were confirmed using our spectral database and 74 others by performing MS/MS experiments. This resulted in the formal or putative identification of 266 metabolites, among which 59 are reported for the first time in human serum.
Metabolic profiles of biofluids obtained by atmospheric pressure ionization mass spectrometry-based technologies contain hundreds to thousands of features, most of them remaining unknown or at least ...not characterized in analytical systems. We report here on the annotation of the human adult urinary metabolome and metabolite identification from electrospray ionization mass spectrometry (ESI-MS)-based metabolomics data sets. Features of biological interest were first of all annotated using the ESI-MS database of the laboratory. They were also grouped, thanks to software tools, and annotated using public databases. Metabolite identification was achieved using two complementary approaches: (i) formal identification by matching chromatographic retention times, mass spectra, and also product ion spectra (if required) of metabolites to be characterized in biological data sets to those of reference compounds and (ii) putative identification from biological data thanks to MS/MS experiments for metabolites not available in our chemical library. By these means, 384 metabolites corresponding to 1484 annotated features (659 in negative ion mode and 825 in positive ion mode) were characterized in human urine samples. Of these metabolites, 192 and 66 were formally and putatively identified, respectively, and 54 are reported in human urine for the first time. These lists of features could be used by other laboratories to annotate their ESI-MS metabolomics data sets.
Plasma electrolytic oxidation (PEO) is a versatile and cost-effective technique to obtain protective oxide coatings in light metals, although its intrinsic porosity is a drawback for long-term ...corrosion resistance. Sol-gel layers are pointed as a useful tool to seal PEO porosity and increase its corrosion resistance, although little is known about its influence on the wear performance of PEO coatings. In this study, a PEO coating obtained on AA2024 was sealed with a hybrid sol-gel via dip-coating. Two withdrawal speeds were set in order to investigate the influence of the sol-gel filling in its sealing ability. Both sol-gel application conditions were able to fill the PEO pores and microcracks and change its wettability. EIS results showed samples sealed with sol-gel maintained the protective behavior upon 28 days and increased the resistance of the system by several orders of magnitude in comparison to unsealed PEO coatings. Pin-on-disk tests indicate the sol-gel decrease the shear stresses of the coating, decreasing its wear rate in 40% compared to the unsealed PEO.
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•Hybrid sol-gel coating sealed pores and cracks from the plasma electrolytic oxidationcoating.•Different withdrawal speeds resulted in different sealing morphologies.•No significant difference in wear and corrosion rate was observed between the sol-gel sealed PEO coatings.•The sol-gel sealed PEO coating reduced the wear rate by 40 % compared to the unsealedPEO coating.•The sol-gel sealing protected the PEO coating against corrosion upon 28 days ofimmersion in corrosive media.
In Louise Glück’s latest collection Faithful And Virtuous Night (2014), the poet’s swerving toward a more narrative form contributes—surprisingly perhaps—to revising the traditional Romantic chiasmus ...that exists between the mourning or suffering personae and their environment. This article attempts at capturing how Glück’s choices in lineation in her verse expose the intrinsic loss and hiatus there is between language and the world. It means to illustrate the way time and lyric subjectivity are structured in Glück’s latest collection.
Abstract
Objective
We aimed to determine patterns of alaryngeal voice acquisition and predictive factors of vocal rehabilitation (VR) failure following total laryngectomy (TL) at a large Canadian ...tertiary care center.
Methods
All consecutive patients having undergone a TL between January 1st, 2011 and December 31st, 2019, at the Centre Hospitalier de l'Université de Montréal were included.
Results
One hundred and ninety‐seven laryngectomized patients were identified. Successful VR was achieved in 86 (59.0%) patients, while 59 (41.0%) failed to use a method of alaryngeal voice as their principal means of communication at 1 year postoperatively. The use of tracheoesophageal puncture (TEP) was associated with higher VR success rates (70.6%) when compared with the artificial larynx (48.6%), and esophageal voice (18.8%). The only independent predictor of VR failure on multivariate analysis at all time points was a low socioeconomic status.
Conclusion
Failure to adopt an alaryngeal voice following TL is highly prevalent, despite comprehensive and free speech language pathologist services being offered at our center. A low resort to TEP at our institution and a poor acceptability and accessibility of alternative VR methods may contribute to this trend. The challenges of VR may be further exacerbated by the barriers linked to a lower socioeconomic status, which in turn may contribute to reduced candidacy for TEP.
The effect of cerium salts on the cut-edge of zinc-based sacrificial coated steel was investigated by theoretical approach (based on individual polarization curves on the top surface and by Scanning ...Vibrating Electrochemical Technique (SVET). In both approaches, cerium salts increase the galvanic corrosion of zinc-based sacrificial layer coupled with steel. Furthermore, the anion parts of cerium salts exhibited a synergistic accelerated effect of galvanic activity on the cross-section. The SVET results indicated that the addition of Al, Mg alloying elements promotes localized corrosion and influences the formation and distribution of corrosion products.
•Effect of CeCl3 and Ce(NO3)3 on the cut-edge of steel coated by zinc alloyed (HDG, ZnAl, and ZAM).•Cerium salts accelerated the corrosion of zinc coated steel on the cut-edge.•NO3- ion exhibited a synergistic accelerating effect on galvanic corrosion.•The presence of Al and Mg alloying elements promotes localized corrosion.
In the present study, the surface of AZ31 Mg alloy was pretreated by etching in nitric acid and plasma electrolytic oxidation (PEO). Then Mg-Al layered double hydroxide (Mg-Al/LDH) was synthesized on ...the pretreated surface of substrates via hydrothermal treatment to increase the corrosion resistance. The effect of surface pretreatment (etched substrate and PEO layer) on LDH formation, structure, and corrosion resistance was investigated. Benzoxazine resin (thermosets), has been used for coatings, however, the high curing temperature limits their applications. For this purpose, a new bio-based benzoxazine resin with a lower curing temperature (160 °C) was developed to be applicable for Mg alloys. Phenol (Phloretic acid), diol (Dodecandiol), and amine (monoethanolamine) were used to synthesize innovative benzoxazine with exchangeable ester functions and self-healing ability. This resin was further used for post-treatment of LDH samples. The morphology, chemical composition, and crystalline structure of LDH samples were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion resistance of the coatings was investigated by salt spray test as well as electrochemical impedance spectroscopy (EIS). The LDH layer on the etched substrates showed better corrosion resistance than the LDH on PEO layer due to having a thicker inner layer (11.8 ± 0.2 μm and 7.0 ± 0.6 μm for LDH on the etched substrate and PEO layer, respectively). Post-treatment of samples with benzoxazine resin showed the effective capability of this polymeric coating for enhancing the corrosion resistance of Mg alloy substrate. This benzoxazine coating increased the corrosion resistance of the coating/substrate system around 104 times in comparison to the bare substrate. Moreover, it was observed that the LDH layer can increase the adhesion and compatibility of the substrate with benzoxazine resin. These results were confirmed by EIS and cross-cut adhesion tests experimentally as well as theoretical calculations of the adsorption energy of benzoxazine molecule to the LDH layer using Density Functional Theory (DFT).
•Forming LDH on pretreated AZ31 Mg alloy (PEO, etched) by hydrothermal method•Post-treatment of Mg alloy substrates with a new bio-based benzoxazine resin•Corrosion protection of benzoxazine for Mg alloy substrates•Enhanced benzoxazine adhesion to LDH, validated experimentally and theoretically (DFT)•Improved corrosion resistance achieved by LDH and benzoxazine for Mg alloy
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