Relative Band Intensities Research Articles

Cyclophilin A as a Novel Mediator in Ventilator‐Induced Lung Injury

RationaleCyclophilin A (CypA) is a ubiquitously distributed cytoplasmic protein. While focus has previously been on its intracellular roles, extracellular CypA and its receptor CD147 have emerged as a novel signalling axis in various inflammatory diseases. We explore the role of the CypA:CD147 axis in ventilator‐induced lung injury (VILI) and hypothesise that CypA is secreted into the alveolar space following epithelial insult where it promotes inflammation during acute lung injury (ALI).MethodsC57BL/6 mice received low‐stretch (LS; tidal volume: 8 mL/kg) or high‐stretch (HS: 40 mL/kg) ventilation for up to three hours (n=6–8/group). For inhibition experiments, mice received a 50 μL intratracheal dose of either a non‐permeable extracellular‐specific CypA inhibitor, MM‐284 (0.67 mM), or vehicle control, DMSO (10%), immediately prior to HS ventilation. Bronchoalveolar lavage fluid (BALF) CypA and soluble receptor for advanced glycation endproducts (sRAGE) were assessed by ELISA; cell activation status (surface ICAM‐1 expression) and intracellular CypA (iCypA) by flow cytometry; and matrix metalloproteinase‐2 (MMP‐2) by gelatin zymography.ResultsDuring VILI, there is a significant early upregulation of BALF CypA at two hours (LS: 663±268 vs HS: 2,586±1,054 pg/mL; p<0.05), preceding signs of physiological deterioration, with further increase at three hours. In contrast, plasma CypA levels showed no significant changes across three hours regardless of ventilation strategy and were consistently below BALF levels. iCypA decreased in EpCAM‐/T1α+ and EpCAM+/T1α‐epithelial cells but not alveolar macrophages. MM‐284 mediated inhibition of extracellular CypA led to protection from the development of VILI (vehicle: 50% vs MM‐284: 100% survival; p<0.05), attenuated lung wet:dry weight ratio (7.0±1.2 vs 5.0±0.2; p<0.001), BALF protein (3.7±1.4 vs 1.3±0.2 mg/mL; p<0.001), BALF sRAGE (40.3±11.2 vs 8.3±3.8 ng/mL; p<0.0001), and deteriorations in elastance and oxygenation (interaction p<0.01). Surprisingly, CypA inhibition appeared to have no impact on leukocyte recruitment into lung tissue but was associated with a reduction in stretch‐induced activation of alveolar macrophages (135.6±18.4 vs 21.8±45.4 ICAM‐1 MFI; p<0.001) and both EpCAM‐/T1α+ (129.1±28.7 vs 91.9±6.1 ICAM‐1 MFI; p<0.05) and EpCAM+/T1α‐(99.8±12.1 vs 76.5±15.2 ICAM‐1 MFI; p<0.05) epithelial cells. Further, CypA inhibition also led to a decrease in active MMP‐2 in BALF (0.9±0.5 vs 0.4±0.2 relative band intensity; p<0.05).ConclusionsWe have demonstrated the involvement of a novel mediator, CypA, in VILI. The early upregulation in BALF and corresponding decrease of iCypA in epithelial cells suggest that CypA is produced locally following epithelial injury. Inhibition of extracellular CypA promoted an impressive attenuation of VILI, particularly parameters related to alveolar‐capillary barrier integrity (e.g. BALF sRAGE, oedema formation, oxygenation, and MMP activity). Together, our findings support the CypA:CD147 axis as a novel mediator of epithelial cell dysfunction during the pathogenesis of VILI.Support or Funding InformationBritish Journal of Anaesthesia/Royal College of Anaesthetists

Simple and Affordable Kinetic Assay of Nucleic Acids by Gel Staining

In an effort to circumvent the pitfalls of using radioactive labeling to measure kinetics in undergraduate labs, a gel staining kinetics assay was developed. The IR‐3 enzyme and substrate, a single stranded DNA that cleaves another single stranded DNA only in the presence of Zn++, was used as a simple and inexpensive DNA model. The rate of the IR‐3, or D‐Zyme, was successfully determined by staining PAGE‐Urea gels with SYBR Gold and then viewing them at 302 nm with epi‐illumination. The open source software ImageJ (version 1.52K) was utilized to quantify the relative band intensities, the ratio of cleaved product to the addition of product and substrate, gave percent cleavage. When percent cleavage was plotted against time in Minitab (version 18.1, Minitab, Inc.), the rate of the reaction could then be determined by nonlinear regression curve‐fitting to the single exponential. To certify this technique, it was also tested on two other models, one being a modified version of the D‐Zyme, while the other was a known Hammer Head Ribozyme, trans RzB. It was demonstrated that the use of SYBR Gold post‐migration staining can be used to quantify RNA and DNA bands for cleavage kinetic analysis, without substrate labeling. Although this method is comparatively less sensitive than radioactive and fluorescence labeling, it has several advantages such as: i) ease of use; ii) cost effective; iii) no half‐life decay; iv) absence of substrate labeling; v) precision enabling curve‐fitting; vi) versatility with non‐structured and structured RNAs or DNAs.Support or Funding InformationMonmouth University Summer Research Program

Judd Ofelt theoretical analysis, Photoluminescence properties of Eu3+activated LiGd(WO4)2 phosphors

A series of efficient red light emitting Eu3+ activated LiGd(WO4)2 phosphors were prepared by solid state method at 800 °C. The PXRD Rietveld refinement results confirmed that all the compounds crystallized in the tetragonal structure with space group I41/a. All the samples showed the characteristic red emission of Eu3+ ions corresponding to the 5D0→7FJ (J = 0,1,2,3,4) transitions at λexc = 395 nm. The concentration quenching was observed above the LiGd(WO4)2:0.07Eu3+ due to charge exchange with neighbouring Eu3+ ions. The critical distance was determined to be about 16.05 Å indicates the multipole-multipole interaction. Judd–Ofelt theoretical analysis of the emission spectra are performed for Eu3+ activated LiGd(WO4)2 phosphors to evaluate the spectral characteristics and radiative properties. The observed trend of Judd–Ofelt intensity parameters Ω2 > Ω4 and domination of strong intense red emission (5D0→7F2) justify the asymmetric site occupancy of Eu3+ ions. In addition, the CL study also shows relative intensity and similar positions of characteristic emission band of rare earth ion as observed in PL spectra. Time resolved fluorescence spectra shows that decay curve is bi-exponential in nature and having lifetime (τ) 0.68 ms. The high color-purity red emission of the phosphor material with chromaticity co-ordinates (0.667, 0.332) in close proximity to that of commercial Y2O3:Eu3+ red phosphors with CIE co-ordinates (0.645, 0.347) corroborates the significance of LiGd(WO4)2:xEu3+ as efficient red emitters.

Serological detection of T. gondii infection in humans using an immunochromatographic assay based on dense granule protein 7.

Toxoplasma gondii causes toxoplasmosis, one of the world's most common parasitic diseases. It secretes large amounts of dense granule antigens (TgGRAs), which are crucial to the parasite's survivability. TgGRA7 is found abundantly on the surface of host cells, within the parasitophorous vacuole lumen and membrane, and the host cell cytosol. It stimulates a strong antibody response during acute and chronic infections. While it has been well utilized as an antigen for enzyme-linked immunosorbent assay (ELISA), only one report has documented its efficacy as an antigen for an immunochromatographic test (ICT) in pigs. To date, there is no study yet documenting its use for ICT in human toxoplasmosis. Here, we validated the efficacy of the TgGRA7-ICT we developed by testing 88 human sera. Results were compared with those obtained by ELISA based on TgGRA7, a commercial ELISA, and latex agglutination test (LAT). With high sensitivity, specificity, and kappa values, our TgGRA7-ICT results revealed very good agreement with standard test results. We also found a strong correlation between the relative ICT band intensity and absorbance values in the ELISA. Altogether, our data suggest that the current ICT with TgGRA7 is a reliable test for the diagnosis of human toxoplasmosis, which produced results similar to conventional serological methods. Thus, this can be used as a screening tool for routine testing of toxoplasmosis and a good option for point of care application. The present study also documents the first utilization of TgGRA7 as an antigen for ICT for the serodiagnosis of human toxoplasmosis.

Luminescence properties of the Ln-EDTA complexes covalently linked to the chitosan biopolymers containing β-diketonate as antenna ligands.

This paper reports on the preparation, characterization, and photoluminescence properties of novel hybrid materials, in which the EDTA-Ln-L complexes (where L: H2 O, acac, bzac, dbm, and tta ligands, and Ln: Eu, Gd, and Tb) were covalently linked to the precursor medium molecular weight chitosan surface (CS) matrices or on the chitosan surfaces previously crosslinked with epichlorohydrin (CSech). The emission spectra of these materials were characterized by intraconfigurational-4fN transitions centred on the Eu3+ and Tb3+ ions. Some broad bands from the polymeric matrix were also observed in the emission spectra, however the relative intensities of the intraconfigurational bands increased significantly for systems containing diketonate ligands when the antenna effect became more efficient. The values of the radiative rates (Arad ) were higher for crosslinked hybrid systems with epichlorohydrin, while nonradiative rates (Anrad ) presented the opposite behaviour. These data contributed to an increase in the values of emission quantum efficiency (η) for crosslinked materials. The effect of the modification process and antenna ligand on the values of intensities, intensity parameters Ω2 e Ω4 of the Eu3+ complexes were also investigated. The results showed that the crosslinked biopolymer surfaces have great potential for applications in molecular devices light converters.

Thermochemical behavior of Eucalyptus grandis wood exposed to termite attack

This study aimed to evaluate the variations in thermal and chemical characteristics of juvenile Eucalyptus grandis wood submitted to a deterioration test by Nasutitermes termites. For this purpose, a biodeterioration test with termites was conducted according to ASTM D 3345 (2008), in which, after the end of the period corresponding to the test (40 days), we evaluated the mass loss, chemical composition and thermal stability of the main components of the deteriorated wood samples and those belonging to the control group. We found that deterioration due to exposure of the samples to Nasutitermes sp. termites caused a mass loss of 66.88% for wood with a density at 12% moisture content of 0.412 g.cm-3. The quantitative chemical composition showed a reduction in the contents of cellulose, hemicellulose and lignin. Analysis of the variations of the organic functional groups related to the chemical composition of the wood by Fourier Transform Infrared Spectroscopy and relative intensity of the spectral bands also showed reductions, demonstrating homogeneous deterioration of the main components of the deteriorated woods. The thermal stability showed an increase in deteriorated wood for most of the temperature ranges, mainly for those that corresponded to losses in moisture and volatiles (25 °C - 100 °C), hemicelluloses (240 °C - 300 °C), celluloses, and together with initial lignin degradation (310 °C to 400 °C), possibly due to the removal of cellulose and hemicellulose, as well as the deposition of substances expelled by the termites in the cell wall. From the results, we conclude that the termites do not have specificity regarding the chemical component and that the deterioration caused variations in the chemical composition of the wood, whereas the opposite was observed for thermal stability, which presented an increase in most of the temperatures ranges for the deteriorated woods compared to the control group.

Using Raman Spectroscopy to Investigate the Molecular Level Characteristics of Endometriosis-=SUP=-*-=/SUP=-

Endometriosis is a benign gynecologic disorder. It is particularly common among young women and may make pregnancy difficult. In this study molecular level characterization of endometriosis tissues were performed using Raman spectroscopy in combination with multivariate statistical analysis. Three hundred sixty-six Raman spectra recorded from different points of seventy two tissue samples, taken from the cyst walls of twelve patients were examined. Principle Component Analysis (PCA) followed by Linear Discriminant Analysis (LDA) were performed on the Raman data, and the samples were then classified into three groups; severe, moderate, and weak endometriosis. In the severe endometriosis group, the relative band intensities of DNA were increased. Moreover, increase in pyrrole moieties and kynurenine were seen. The results show that endometriosis severity correlates to increase in DNA concentration, and degradation of tryptophan due to increased indoleamine-pyrrole 2, 3-dioxygenase (IDO) activity, and an increase in kynurenine concentration and pyrrole intermediate. It is concluded that Raman spectroscopy is capable of providing a quick diagnosis, ahead of the pathology result being reported. Keywords: Endometriosis; Raman spectra, PCA-LDA analysis.

Effect of oxide additives on up-conversion luminescence of erbium ions in alkaline germanate glasses

The effect of additives in sodium germanate glass on the up-conversion luminescence of an erbium ion was studied. Samples of glasses were prepared by high-temperature synthesis in corundum crucible. Synthesis temperature was 1250 °С. Synthesized glass had a composition of 58,95GeO2–27,79Na2O–8,67Yb2O3–4,34LaO–0,25Er2O3 mol% with additives of 5 mol% of the following oxides: Al2O3, Nb2O5, SiO2, BaO, TiO2, PbO, P2O5, MgO. Up-conversion luminescence spectra were recorded in the wavelength range from 450 to 700 nm when excited by a semiconductor laser at 975 nm. Three bands were identified on the luminescence spectra corresponding to radiative transitions of the erbium ion 2H11/2→4I15/2 with maximum of about 520 nm; 4S3/2→4I15/2 with maximum of 550 nm and 4F9/2→4I15/2 with maximum of 670 nm. The luminescent properties of the glass with additives were compared to those of the initial glass. The effect of additives on the relative intensity redistribution of upconversion luminescence was shown. Compared to the red luminescence band (4F9/2→4I15/2), the green band (2H11/2→4I15/2) intensity is a maximum for glass with the addition of phosphorus oxide; glass with the addition of lead oxide has the minimum intensity. The obtained dependence of the relative intensities of the up-conversion luminescence bands on the glass composition can find practical application in the development of optical luminescent sensors, as well as up-converters for solar cells.

Charge Transfer, Complexes Formation and Furan Fragmentation Induced by Collisions with Low-Energy Helium Cations.

The present work focuses on unraveling the collisional processes leading to the fragmentation of the gas-phase furan molecules under the He+ and He2+ cations impact in the energy range 5–2000 eV. The presence of different mechanisms was identified by the analysis of the optical fragmentation spectra measured using the collision-induced emission spectroscopy (CIES) in conjunction with the ab initio calculations. The measurements of the fragmentation spectra of furan were performed at the different kinetic energies of both cations. In consequence, several excited products were identified by their luminescence. Among them, the emission of helium atoms excited to the 1s4d 1D2, 3D1,2,3 states was recorded. The structure of the furan molecule lacks an He atom. Therefore, observation of its emission lines is spectroscopic evidence of an impact reaction occurring via relocation of the electronic charge between interacting entities. Moreover, the recorded spectra revealed significant variations of relative band intensities of the products along with the change of the projectile charge and its velocity. In particular, at lower velocities of He+, the relative cross-sections of dissociation products have prominent resonance-like maxima. In order to elucidate the experimental results, the calculations have been performed by using a high level of quantum chemistry methods. The calculations showed that in both impact systems two collisional processes preceded fragmentation. The first one is an electron transfer from furan molecules to cations that leads to the neutralization and further excitation of the cations. The second mechanism starts from the formation of the He−C4H4O+/2+ temporary clusters before decomposition, and it is responsible for the appearance of the narrow resonances in the relative cross-section curves.

Analysis of protein profiles and peptides during in vitro gastrointestinal digestion of four Chinese dry-cured hams

In this study, the in vitro digestion with pepsin and trypsin enzymes was applied to mimic the gastrointestinal digestion of dry-cured hams from different producing districts of China. The analysis of digestibility and particle size revealed that the digestion characteristics of different dry-cured hams were significantly different (p < 0.05). During the gel electrophoresis analysis, protein profiles were characterized by analyzing 14 and 9 proteins generated during pepsin and pepsin/trypsin digestion. The relative intensities of protein bands could be used to distinguish different dry-cured hams based on principal component analysis (PCA) and linear discriminant analysis (LDA). According to the analysis of peptide profiles, more than 50% of peptides were distributed in the molecular weight ranging from 1500 to 2500 Da, and two-step digestion had little effect on peptide generation due to the cleavage site specificity of pepsin and trypsin. This study provided evidences that it was possible to identify producing districts of different dry-cured hams based on digested characteristics.

Development of a Multicolor Line-Focus Microscope for Rapid Acquisitions of Excitation Spectra

To conduct rapid microscope observations with the excitation spectral measurement for photosynthetic organisms, a wavelength-dispersive line-focus microscope was developed. In the developed system, fluorescence signals at multiple positions on a sample excited with different wavelengths can be detected as a two-dimensional image on the EMCCD camera at the same time. Using the developed system, one can obtain excitation spectra at every pixel over the excitation wavelength range from 635 to 695 nm, which covers the full range of the Qy bands of both chlorophyll-a and chlorophyll-b. Recording the reference laser spectra at the same time ensures robust measurement against the moderate spectral fluctuation in the excitation laser. Using an objective lens with a numerical aperture of 0.9, the lateral and axial resolutions of 0.56 and 1.08 μm, respectively, were achieved. The theoretically limited and experimentally estimated spectral resolutions of the excitation spectral measurement were 0.86 and 1.3 nm, respectively. The validity of the system was demonstrated by measuring fluorescent beads and single cells of a model alga, Chlamydomonas reinhardtii. Intrachloroplast inhomogeneity in the relative intensity of the chlorophyll-b band could be visualized in Chlamydomonas cells. The inhomogeneity reflects the intrachloroplast variation in the local peripheral antenna size.

The prediction of far-infrared spectra for molecular crystals of forensic interest – Phenylethylamine, ephedrine & pseudoephedrine

Synchrotron far-infrared (far-IR) spectra were measured for a representative set of pharmaceutical-type molecular crystals: phenylethylamine hydrochloride salt, ephedrine base and its hydrochloride salt, and pseudoephedrine base and its hydrochloride salt. Resolved spectral profiles in the 30–600 cm−1 range allowed for comparison of absorption bands to simulated spectra obtained by periodic density function theory (DFT) code. The B3LYP-D3/6-311G(d) level of theory returned highly accurate predictions of the experimental far-IR spectra for well-ordered crystalline samples, including an agreement between relative peak intensities almost unprecedented for organic crystal systems of this size. Simulated far-IR spectra for the phenylethylamine hydrochloride and ephedrine base samples do not match to the same degree; potentially due to higher disorder within the solid-state. These comparisons to theory generally allowed for confident assignment of prominent absorption bands to low-lying vibrational modes. The experimental spectra (including those for related illicit drug compounds: amphetamine sulphate, methamphetamine hydrochloride, MDA hydrochloride, and MDMA hydrochloride), peak assignments, and relative band intensities are compiled and evaluated for their inclusion in spectral libraries and their application to chemometric analysis for mixed compounds of pharmaceutical and forensic interest.

Characterization for the transformation of dissolved organic matters during ultraviolet disinfection by differential absorbance spectroscopy.

The transformation of dissolved organic matter (DOM) during various disinfection processes has raised great concerns due to the generation of carcinogenic disinfection by-products (DBPs). Ultraviolet (UV) irradiation is an effective method for drinking water disinfection, during which DOM undergoes changes in functional groups and molecular weight. In this study, the spectrophotometric titration and gel permeation chromatography (GPC) determination were employed to investigate the changes in oxygenated groups and weight-averaged molecular weight (Mw) of two typical DOM during UV irradiation. The differential absorbance spectra (DAS) of DOM could be deconvoluted into six Gaussian bands. The change of relative band intensity was attributed to the change of oxygenated groups (carboxylic and phenolic groups), which was confirmed by combining DAS data and revised Non-Ideal Competitive Adsorption -Donnan model. The GPC result demonstrated that the Mw of DOM decreased after UV disinfection. Moreover, a linear correlation between Mw and the intensity of deconvoluted Gaussian band from DAS was established, which might be served as an alternative approach to estimate Mw and predict the hydrophobicity and DBPs formation potential of DOM in drinking water treatment and monitoring.

Polymerization of Bulky of Oxirane Monomers Leading to Polyethers Exhibiting Intramolecular Charge Transfer Interactions

AbstractThree novel oxirane monomers, 2‐methoxycarbonyl‐3‐(3,4‐dibenzyloxyphenyl)oxirane (MDBPO), 2‐benzyloxycarbonyl‐3‐(3,4‐dibenzyloxyphenyl)oxirane (BDBPO), and 2‐t‐butyloxycarbonyl‐3‐(3,4‐dibenzyloxyphenyl)oxirane (TBDBPO) are prepared and polymerized using BF3‐OEt2 in CH2Cl2 to yield polyethers. The monomers smoothly lead to polymers under the cationic conditions in spite of the monomers' rather bulky structures. The obtained polymers exhibit characteristic UV spectra with intramolecular charge transfer (ICT) bands through hetero π‐stacked structure formed between the side‐chain carbonyl group and the phenyl group directly connects to the main chain. The relative intensity of the ICT bands is the strongest for poly(TBDBPO) having bulky t‐butyl ester group. This spectral feature is considered to have connection with rigidity of polymer chain. Poly(TBDBPO) having the bulkiest side‐chain group is considered to possess the most rigid chain conformation that can account for its strongest ICT interactions that may occur between the carbonyl group and the phenyl group directly attached to the main chain. The proposed rigid chain conformation of poly(TBDBPO) is supported by the fact that the polymer does not show clear Tg while the other two polymers do.

UV emitting Pb2+ doped Ca2La8(SiO4)6O2 phosphors prepared by sol-gel procedure

Pb2+ ions doped Ca2La8(SiO4)6O2 phosphors were prepared by a sol-gel process. X-ray diffraction patterns indicated that these doped samples exhibited a hexagonal Ca2La8(SiO4)6O2 structure. From luminescence spectra analysis, the introduction of Pb2+ ions into Ca2La8(SiO4)6O2 resulted in an emission band at 327 nm. Relative intensities of bands varied depending on the concentration of Pb2+ ions.

Optical properties of folic acid in phosphate buffer solutions: the influence of pH and UV irradiation on the UV-VIS absorption spectra and photoluminescence

Using UV-VIS absorption spectroscopy, photoluminescence (PL) and photoluminescence excitation (PLE), the photodegradation reactions of folic acid (FA) in phosphate buffer (PB) solutions were studied. Regardless of the PB solution’s pH, the UV-VIS spectra showed a gradual decrease in absorbance at 284 nm simultaneous with an increase in the absorbance of another band in the spectral range of 320–380 nm, which was downshifted under UV irradiation. The relative intensity of the FA PL band, situated in the spectral range 375–600 nm, was dependent on the pH of the PB solution. The FA PL intensity increased as increasing UV irradiation time up to 281 min. in PB solutions with pH values of 6.4 and 5.4. Under an emission wavelength of 500 nm, the position of the FA PLE spectrum changed as the PB solution pH varied from 7 to 5.4 and the irradiation time increased to 317 min. These changes were correlated with the formation of two photodegradation products, namely, pterine-6-carboxylic acid and p-amino-benzoyl-L-glutamic acid. According to UV-VIS spectroscopy and PL and PLE studies, the presence of various excipients in commercial pharmaceutical tablets does not affect the photodegradation of FA in PB solutions. Using IR spectroscopy, new evidences for the formation of the two photodegradation products of FA in PB solutions are shown.

High-Temperature Evolution of Point Defect Equilibria in Hydrous Forsterite Synthesized at 1100 °C and up to 4 GPa

Water distribution in the deep Earth represents one of the most important topics in the field of geodynamics due to its large impact on the physical and chemical properties of the Earth’s mantle, such as electrical conductivity, seismic anisotropy, diffusion, and rheology. In this study, we synthesized hydrous forsterite at 1100 °C and up to 4 GPa with either a piston-cylinder or multianvil apparatus. As a starting material, we used synthetic forsterite, unbuffered by SiO2, obtained by thermo-mechanical activation of talc and magnesium carbonate hydroxide. Hydration was carried out using liquid H2O as hydrogen source. Samples were polycrystalline in an effort to distribute H2O throughout the sample both rapidly and homogeneously. Using the Paterson calibration, we observed total water content concentrations ranging between 100 and 500 ppm wt H2O. Multiple absorption bands are found in the frequency range between 3400 and 3650 cm−1, identifying at least seven peaks in all samples. Vibrational bands were centered at 3476, 3535, 3550, 3566, 3578, 3605, and 3612 cm−1, in good agreement with experimental studies conducted on both hydrous forsterite and single crystals of olivine. The stronger OH stretching peaks can be attributed to vibrational modes associated with the hydrogarnet defect 4 H Si x in which four protons occupy a vacant tetrahedral site. None of the OH bands observed are found at frequencies associated with hydrogen occupying vacant octahedral sites. High-temperature FTIR spectroscopy was used to evaluate the evolution of IR spectra as a function of temperature, up to 500 °C. The complete reversibility of peak absorption vs. temperature in the OH stretching region confirms that no water loss occurred during heating. We observe an overall a decrease in total absorption with increasing temperature, and a prominent decrease in the relative intensities of the higher frequency bands (&gt;3600 cm−1) with respect to lower frequency bands. We have assigned a series of equilibrium expressions based on the variation of relative peak areas with temperature and find that enthalpies of these processes range between 0.047–0.068 eV (4.5–6.5 kJ/mol), very low in comparison to activation energies observed for electrical conduction in hydrous olivine. Major changes in the vibrational spectrum are expected to be related to configurational changes of the same fully protonated hydrogarnet defect species. However, the complexity of the FTIR spectra may also be related to partially protonated defects, such as the associate defect 3 H Si ′ + H i • generated by a dissociation reaction of the hydrogarnet species.

Indexing electron backscatter diffraction patterns with a refined template matching approach

Electron backscatter diffraction (EBSD) is a well-established method of characterisation for crystalline materials. Using this technique, we can rapidly acquire and index diffraction patterns to provide phase and orientation information about the crystals on the material surface. The conventional analysis method uses signal processing based on a Hough/Radon transform to index each diffraction pattern. This method is limited to the analysis of simple geometric features and ignores subtle characteristics of diffraction patterns, such as variations in relative band intensities. A second method, developed to address the shortcomings of the Hough/Radon transform, is based on template matching of a test experimental pattern with a large library of potential patterns. In the present work, the template matching approach has been refined with a new cross correlation function that allows for a smaller library and enables a dramatic speed up in pattern indexing. Refinement of the indexed orientation is performed with a follow-up step to allow for small alterations to the best match from the library search. The refined template matching approach is shown to be comparable in accuracy, precision and sensitivity to the Hough based method, even exceeding it in some cases, via the use of simulations and experimental data collected from a silicon single crystal and a deformed α-iron sample. The speed up and pattern refinement approaches should increase the widespread utility of pattern matching approaches.

Catalyst-free low temperature conversion of n-dodecane for co-generation of COx-free hydrogen and C2 hydrocarbons using a gliding arc plasma

In this study, plasma reforming of n-dodecane for the co-generation of COx-free hydrogen and C2 hydrocarbons at low temperature and ambient pressure has been investigated in a gliding arc discharge (GAD) reactor. The selective synthesis of H2, C2H2 and C2H4 and the energy efficiency for n-dodecane conversion can be tuned by changing different processing parameters including the gas flow rate, n-dodecane concentration and input voltage. The highest selectivities of H2 (76.7%), C2H2 (41.4%) and C2H4 (12.0%) were achieved with an n-dodecane conversion of 68.1%. The generation of mixed hydrogen, acetylene and ethylene offers the possibility for in-situ hydrogenation to enhance the selectivity of light olefins (e.g., ethylene) without prior gas separation. The plausible reaction mechanism and pathways in the plasma cracking of n-dodecane have been discussed through plasma emission spectroscopic diagnostics coupled with a comprehensive analysis of gas and liquid products. A strong correlation between the yield of C2 hydrocarbons and the relative intensity of C2 Swan bands was found, which suggests that C2 Swan bands could be used as a valuable probe to understand the generation of C2 hydrocarbons in the plasma reforming of hydrocarbon oils.

The influence of the number of shock waves and the energy flux density on the Raman spectrum of collagen type I from rat

Shock waves are used to treat musculoskeletal injuries and trigger the body’s mechanisms to initiate healing; however, the cellular and molecular working mechanisms are not fully known. Raman spectroscopy may be a useful tool to provide information on structural changes. Solid collagen type I from rat tail (> 90% pure) was suspended in water and was exposed in vitro to different numbers of shock waves and energy flux densities. Raman spectra were recorded at 2 h, 1 week, and 3 weeks after shock-wave treatment. The spectral analysis indicated that varying the number of shock waves and the energy flux density induced molecular changes in the collagen structure. Varying the energy flux density induced more significant changes than modifying the number of shock waves; however, in most cases, the collagen recovered its original conformation 3 weeks after treatment. A significant decrease in the relative intensities of the conformational bands, which include amide I, amide III, and stretching C–C, was observed at different energy flux densities. In many clinical cases, the natural repair of tissue is improved after shock-wave treatment. Raman spectroscopy revealed that varying the energy flux density of the shock waves applied to rat collagen type I induced strong conformational molecular changes. Approximately 2–3 weeks after shock-wave treatment, a phase of “molecular ordering” tending to a “recovering molecular sequence repair” was observed.