Deeper investigation of oxygen-containing compounds in oleaginous feedstock (animal fat) by preparative column chromatography and comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry.

The production of renewable fuels as biodiesel and bio-jet fuel is usually originated by the transformation and processing of oleaginous feedstocks, mainly composed of triacylglycerols. Currently, a significant part of the triacylglycerol production relies on grassy oil crops or other woody oil plants, representing more than 120 million metric tons every year. Considering that the worldwide triacylglycerol demand is expected to rise in the future, alternative routes are necessary to ensure a sustainable biodiesel industry and limit diesel price volatility. In this context, the use of animal fats could be an interesting alternative for biodiesel production as the production of animal byproducts represents nearly 17 million tons per year in the European Union only (2020). Animal fats, however, contain large amounts of no-esterified fatty acids and other oxygen compounds, reducing the yield of biodiesel. Therefore, a specific pretreatment is needed before the trans-esterification process. The setup of such appropriate pretreatments requires detailed upstream characterization of the minor components present in the feedstock. For this purpose, the minor component profile of animal fat was investigated by comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry. This was preceded by an innovative sample fractionation and focalization of these minor components by a preparative liquid chromatographic column method. The overall method permitted to extract different levels of information from the two-dimensional chromatograms, leading to a tentative identification of more than 150 compounds, mainly oxygenated, belonging to different chemical classes.

Amperometric determination of ecotoxic N-methyl-p-aminophenol sulfate in photographic solution and river water samples based on graphene oxide/CeNbO4 nanocomposite catalyst.

The electronic conductivity of the metal oxides is generally increased by hybridization of highly conductive carbon supportive materials. In this present work, we have demonstrated a novel one-pot preparation of cerium niobate (CeNbO4) nanoparticles embedded with graphene oxide (GO/CeNbO4) composite, for ultrasensitive detection of the photographic developing agent, metol (MTL). The as-prepared GO/CeNbO4 was analyzed by various characterization techniques. The intensive characterization techniques were used to affirm the detailed structural moiety, size, morphology, and surface area of GO/CeNbO4. The GO/CeNbO4 modified glassy carbon electrode (GCE) affords a superior electrocatalytic activity toward MTL. The obtained amperometric response on the GO/CeNbO4/GCE holding an extremely low level detection of 10 nM and superior sensitivity of 10.97 µA µM-1 cm-2 toward MTL detection. Besides, the GO/CeNbO4/GCE also gives excellent selectivity, stability, repeatability, and reproducibility. We achieved excellent recovery results in real photographic solution and river water samples analysis with great accuracy. This work offers a novel insight into the growth of the carbon-based niobate family with electrochemical sensor applications.

[Use of methoxyflurane on acute pain during burn dressing in adult consultation]. / Utilisation du méthoxyflurane sur la douleur aiguë lors du pansement en consultation des brûlés adultes.

INTRODUCTION: The objective was to compare the short-term efficacy of methoxyflurane vs. MEOPA on acute pain during burn dressing in consultation, the secondary outcome was to assess the patient's comfort and the quality of the dressing performed. MATERIALS AND METHODS: Monocentric, prospective study from April 2018 to January 2019. Men and women>18 years presenting acute burn on<10% SCT were included. A pain≥4 on the numerical scale (from 0 to 10) at the beginning of the treatment established the indication of methoxyflurane or MEOPA, with randomization done by a nurse. The following data were collected: burn description, performed debridement, pain assessment by numerical scale: on arrival, at the beginning of care, after 6 to 10 inhalations for methoxyflurane or 3 to 4minutes of inhalation for MEOPA and at the end of care. RESULTS: Sixty patients were included, 30 in each group. There was a decrease of -2.47 points of numerical scale when initiating methoxyflurane against -1.53 points for MEOPA (P=0.08). Patients were significantly less painful when stopping treatment in the methoxyflurane group -4 points vs -2 points (P=0.001). Methoxyflurane significantly improved the debridement of the burn (P=0.018). CONCLUSION: Methoxyflurane is more effective than MEOPA in acute pain in burn dressing, improved patient comfort, and improved dressing quality.

Effects of economic crisis on air quality in Ioannina, Greece.

The aim of this study was to investigate the regime of air pollution in Ioannina, NW Greece during the years of Greek financial crisis. Annual, weekly and daily patterns for PM10, PM2.5, NO2, O3 and Benzene were defined in order to reveal the sources of air pollutants in Ioannina and the time periods of probable episodes. The quality of air was characterized according to the European Environment Agency's European Air Quality Index, separately for winter and summer, while it was examined if and in what extend the thresholds of European Directives for each pollutant have been exceeded. The air quality in Ioannina was found to be "Good" as far as NO2 and O3 were concerned. In contrast, there were many cases with "Poor" and "Very Poor" conditions related to PM10 and PM2.5 levels, mainly during winter and autumn, caused by wood burning for residential heating. The mean annual concentrations of all pollutants did not exceed EU's standards, but from 2011 onwards, the number of cases with PM10 mean daily concentration above threshold surpassed the number of permitted exceedences of EU directives.

A randomized cross-over trial on the direct effects of oxygen supplementation therapy using different devices on cycle endurance in hypoxemic patients with Interstitial Lung Disease.

BACKGROUND: In patients with interstitial lung disease (ILD) a cardinal feature is exercise intolerance, often associated with significant dyspnea and severe hypoxemia. Supplemental oxygen therapy may be offered during exercise. The Oxymizer is a nasal cannula with an incorporated reservoir with the potential to deliver higher oxygen doses to the patient. OBJECTIVE: The primary aim was to investigate the effect of supplemental oxygen delivered via Oxymizer compared to a conventional nasal cannula (CNC) in patients with ILD during constant work rate tests (CWRT). Secondary aim was to evaluate effects on oxygen saturation (SpO2), dyspnea and heart rate at isotime. METHODS: In this randomized crossover study 24 ILD patients established on long-term oxygen treatment were included. Patients performed four cycling CWRT at 70% of their peak work rate; twice with the Oxymizer and twice with the CNC. RESULTS: Twenty-one patients finished all CWRTs (age 60 ± 10.9 years, VC 55.4 ± 23.0%predicted). Cycle endurance time was significantly higher while using the Oxymizer compared to CNC (718 ± 485 vs. 680 ± 579 seconds, p = 0.02), and SpO2 at isotime was significantly higher while using the Oxymizer (85.5 ± 6.7 vs. 82.8± 7.2, p = 0.01). Fifteen of the 21 (71%) patients cycled longer with the Oxymizer. There were no significant differences for dyspnea and heart rate. CONCLUSIONS: Supplemental oxygen provided by the Oxymizer significantly, but modestly, improved cycle endurance time and SpO2 at isotime in ILD patients compared to CNC.

[MEOPA use practices in a university hospital: Which conformity?] / Pratiques d'utilisation du MEOPA dans un CHU : quelle conformité ?

INTRODUCTION: MEOPA (equimolar mixture of oxygen and nitrous oxide) is used for its analgesic and anxiolytic properties in order to obtain conscious sedation of the patient when performing painful care. It is subject to an enhanced pharmacovigilance and addictovigilance monitoring. In this context, it is important to dispose of hospital utilization data. This work aims to assess the compliance of the use of nitrous oxide regarding the recommendations of the summary of product characteristics, in a French university hospital (Nantes) and consider possible improvements. MATERIALS AND METHODS: Transversal descriptive study, conducted in 2014 with all health professionals using MEOPA. RESULTS: Two thousand thirty-four health professionals answered the questionnaire ; durations of administrations are in conformity and the premises are generally appropriate but almost 60% of professionals have the feeling of inhaling the drug. The systematization of the prescription (always or almost always prescribed for 67% of professionals) and traceability of use (always or almost always in the patient's file for 71% of professionals) are potential source of improvement, particularly since 18% of professional health reported "abuse demands" from patients. CONCLUSION: The formation and information of health professionals are major issues of good use of nitrous oxide.

[How to perform a gynecological examination in the girl]? / Comment réaliser un examen gynécologique chez la petite fille ?

How to perform a gynecological examination in the girl ? Precautionary gynecological examination is very important in the pre-pubescent girl, since it allows the diagnosis of most pathologies. Parents should be present in order to establish a climate of trust. The most suitable position is that of "the frog". The use of MEOPA (nitrogen monoxide-oxygen mixture) is valuable. The main reasons for consultation are vulvitis, leucorrhea and genital haemorrhage. Complementary examinations are rarely indicated, particularly bacteriological samples which are painful and usually unnecessary.

Comment réaliser un examen gynécologique chez la petite fille ? Chez la petite fille prépubère, un examen gynécologique soigneux et bien conduit est primordial puisqu'il permet de diagnostiquer la plupart des pathologies. Il est souhaitable que les parents soient présents, afin d'établir un climat de confiance. La position la plus adaptée est celle de la grenouille. L'utilisation du mélange équimoléculaire oxygène-protoxyde d'azote (MEOPA) est une aide précieuse. Les principaux motifs de consultation sont la vulvite, les leucorrhées, les hémorragies génitales. Les examens complémentaires sont rarement indiqués, notamment les prélèvements bactériologiques, qui sont douloureux et le plus souvent inutiles.

Note: Effective anvil size for transverse delamination test of rare-earth-Ba2Cu3Oy coated conductor tapes.

In coated conductor (CC) tapes used in magnet and coil applications, delamination due to excessive transverse tensile stresses is still one of the major issues that need considerations. Recently, several methods in evaluating the delamination strength of CC tapes are being used. In the case of anvil test, size of the anvils will be an important factor considering its applications (i.e., superconducting coil impregnation). In this study, delamination strength of CC tape was examined using different upper anvil sizes and their effects were discussed. Finally, reasonable sizes of upper anvil to be used were proposed considering the application conditions.

The unexpected mechanism underlying the high-valent mono-oxo-rhenium(V) hydride catalyzed hydrosilylation of C=N functionalities: insights from a DFT study.

In this study, we theoretically investigated the mechanism underlying the high-valent mono-oxo-rhenium(V) hydride Re(O)HCl2(PPh3)2 (1) catalyzed hydrosilylation of C=N functionalities. Our results suggest that an ionic S(N)2-Si outer-sphere pathway involving the heterolytic cleavage of the Si-H bond competes with the hydride pathway involving the C=N bond inserted into the Re-H bond for the rhenium hydride (1) catalyzed hydrosilylation of the less steric C=N functionalities (phenylmethanimine, PhCH=NH, and N-phenylbenzylideneimine, PhCH=NPh). The rate-determining free-energy barriers for the ionic outer-sphere pathway are calculated to be ∼28.1 and 27.6 kcal mol(-1), respectively. These values are slightly more favorable than those obtained for the hydride pathway (by ∼1-3 kcal mol(-1)), whereas for the large steric C=N functionality of N,1,1-tri(phenyl)methanimine (PhCPh=NPh), the ionic outer-sphere pathway (33.1 kcal mol(-1)) is more favorable than the hydride pathway by as much as 11.5 kcal mol(-1). Along the ionic outer-sphere pathway, neither the multiply bonded oxo ligand nor the inherent hydride moiety participate in the activation of the Si-H bond.

On-line combination of high performance liquid chromatography with comprehensive two-dimensional gas chromatography-triple quadrupole mass spectrometry: a proof of principle study.

The present contribution is focused on the on-line combination of high performance liquid chromatography (HPLC), cryogenically modulated comprehensive two-dimensional gas chromatography (GC × GC), and triple quadrupole mass spectrometry (QqQ MS), generating a very powerful unified separation-science tool. The instrument can be used in seven different combinations ranging from one-dimensional HPLC with a photodiode array detector to on-line LC × GC × GC/QqQ MS. The main focus of the present research is directed to the LC-GC × GC/QqQ MS configuration, with its analytical potential shown in a proof-of-principle study involving a very complex sample, namely, coal tar. Specifically, a normal-phase LC process enabled the separation of three classes of coal tar compounds: (1) nonaromatic hydrocarbons; (2) unsaturated compounds (with and without S); (3) oxygenated constituents. The HPLC fractions were transferred to the GC × GC instrument via a syringe-based interface mounted on an autosampler. Each fraction was subjected to a specific programmed temperature vaporizer GC × GC/QqQ MS untargeted or targeted analysis. For example, the coal tar S-containing compounds were pinpointed through multiple-reaction-monitoring analysis, while full-scan information was attained for the oxygenated constituents.

Enzymatic epoxidation of soybean oil using ionic liquid as reaction media.

An ionic liquid (IL) system for the enzymatic epoxidation of soybean oil was studied. The effects of active oxygen carriers (different fatty acids) and ILs ([Bmim]PF6 and [Bmim]BF4) on the enzymatic epoxidation were investigated. Response surface methodology (RSM) was used to study and optimize the effects of variables (reaction time, reaction temperature, molar ratio of H2O2/C=C-bonds, and molar ratio of fatty acid/C=C-bonds) on the epoxy oxygen group content (EOC) of epoxidized soybean oil (ESO). Results showed that the enzymatic epoxidation of soybean oil can be enhanced using tetradecanoic acid (C13H27COOH) as active oxygen carrier and [Bmim]PF6 as reaction medium. The optimum EOC of ESO was 5.9 ± 0.3% under the following conditions: reaction temperature 46°C, reaction time 11 h, enzyme load 3% (w/w, relative to the weight of soybean oil), molar ratio of H2O2/C=C-bonds 1.8:1, and molar ratio of C13H27COOH/C=C-bonds 0.5:1.

Study on co-pyrolysis characteristics of rice straw and Shenfu bituminous coal blends in a fixed bed reactor.

Co-pyrolysis behaviors of rice straw and Shenfu bituminous coal were studied in a fixed bed reactor under nitrogen atmosphere. The pyrolysis temperatures were 700°C, 800°C and 900°C, respectively. Six different biomass ratios were used. Gas, tar components were analyzed by a gas chromatograph and a gas chromatography-mass spectrometry respectively. Under co-pyrolysis conditions, the gas volume yields are higher than the calculated values. Co-pyrolysis tar contains more phenolics, less oxygenate compounds than calculated values. The addition of biomass changes the atmosphere during the pyrolysis process and promotes tar decomposition. The SEM results show that the differences between the blended char and their parents char are not significant. The results of char yields and ultimate analysis also show that no significant interactions exist between the two kinds of particles. The changes of gas yield and components are caused by the secondary reactions and tar decomposition.

Paper-based colorimetric immunosensor for visual detection of carcinoembryonic antigen based on the high peroxidase-like catalytic performance of ZnFe2O4-multiwalled carbon nanotubes.

A new paper-based colorimetric immunosensor for the detection of carcinoembryonic antigen (CEA) was developed based on the intrinsic peroxidase activity of ZnFe2O4-multiwalled carbon nanotubes (ZnFe2O4@MWNTs). The immunosensor platform was prepared by depositing chitosan and porous gold onto filter paper and entrapping the primary antibodies (Ab1) onto the layers. Secondary antibodies (Ab2) were assembled on the surface of the functionalized ZnFe2O4@MWNTs. The immunosensor response was quantified as a color change resulting from ZnFe2O4@MWNTs catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine in the presence of H2O2. The catalytic performance of ZnFe2O4@MWNTs was higher than ZnFe2O4 due to the high electrical conductance of MWNTs, moreover, the electron communications between ZnFe2O4@MWNTs and substrates are electrically "wired". Detection was achieved by measuring the color change when the concentrations of CEA were different. The color change can be quantified with the naked eye but a digitalized picture can also be used to provide more sensitive comparison to a calibrated color scheme. This method was simple for CEA detection with a linear range from 0.005 to 30 ng mL(-1) and a detection limit of 2.6 pg mL(-1). Such an equipment-free immunoassay has great potential in resource-limited environments.

[Renal denervation for resistant hypertension without general anesthesia: advantage of a MEOPA morphine protocol. Preliminary experience]. / Dénervation rénale pour HTA réfractaire sans anesthésie générale : intérêt d'un protocole MEOPA Morphine. Expérience préliminaire.

UNLABELLED: Renal denervation using the technique of radiofrequency is used only recently for the treatment of resistant hypertension. Normally, it is done under general anesthesia because the ablation point technique is painful. We suggest an alternative to general anesthesia comprising an association of morphin 0.1mg/kg IV to MEOPA (gas combining oxygen and azot protoxyd) delivered through an oxygen mask. Our series includes 12 consecutive patients treated between October 2011 and June 2013, the first five patients (group 1) have received only an hydroxizin and morphin sedation. Every five have felt the ablation painful, in two cases bearable pain (EVA<5), in three cases intense (EVA>5) pain leading to increasing doses of morphin, (total dose of 0.25mg/kg in two cases, 0.17mg in one case). For the seven following patients, a protocol including hydroxyzin, morphin and MEOPA given through a mask has been set up. Only one patient has felt a mild pain (EVA 5) leading to an increasing dose of morphin (total dose 0.17mg/kg). None of the six other patients has felt any pain during the procedure. The average dose of morphin is 0.17mg/kg in group 1, 0.11mg/kg in group 2. This is a preliminary study; if confirmed, it will allow a lot of hospitals without on-site possibilities of general anesthesia, to realize such procedures. CONCLUSION: regarding pain, the procedure of renal ablation was well tolerated for six among seven patients receiving the association MEOPA and IV morphin. In contrast, in the five patients treated only with IV morphin, we observed a less good tolerance to pain and the need to increase the doses of IV morphin.

Experimental determinations and quantum-chemical calculations of the vibrational spectra of ß-ZnB4O7 and ß-CaB4O7.

The two oxoborates ß-ZnB4O7 and ß-CaB4O7 were synthesized and investigated by FTIR- and Raman spectroscopy and ab initio quantum chemical calculations. Maximum and mean deviations between experimentally determined bands and calculated modes ranged between 15-36 cm(-1) and 5-7 cm(-1), respectively, allowing band assignments to vibrational modes in most cases. The complex network structures with tetrahedral BO4 and planar OB3 groups are mirrored by the spectra and numerous vibrational modes, not assignable by standard borates classification schemes. It was confirmed that OB3 units, despite similar force constants and geometry, do not absorb in the same range as BO3 units. Bands in the high wavenumber range are rather caused by B-O-(Zn/Ca), O-B-O, B-O-B, and B-O stretching and bending vibrations. The experimental observation of inactive or Raman-active modes in the absorption spectra indicates defects or structural distortions in both compounds.

Structural characterization and unusual reactivity of oxosulfido-Mo(V) compounds: implications for the structure and electronic description of the very rapid form of xanthine oxidase.

The first structural characterization of a mononuclear, EPR-active, oxosulfido-Mo(V) compound related to the very rapid form of xanthine oxidase (VR-XnO) is reported. The compound, [CoCp2][Tp(iPr)Mo(V)OS(2-OC6H4CO2Et)] [Cp = cyclopentadienyl; Tp(iPr) = hydrotris(3-isopropylpyrazol-1-yl)borate], exhibits a distorted octahedral geometry with Mo═O and Mo=/--S distances of 1.761(5) and 2.215(2) Å, respectively, and an O═Mo=/--S angle of 107.33(14)°. Significantly, the Mo(V)=/--S distance is much shorter than the value of 2.36 Å reported for oxosulfido-Mo(V) compounds (Singh, R.; et al. Inorg. Chem. 1989, 28, 8) but close to the range established for VR-XnO by protein crystallography. The methyl and phenyl esters were also prepared but the latter is highly reactive and undergoes an intramolecular, radical-based cyclization/elimination reaction to form [CoCp2][Tp(iPr)Mo(IV)O{2-OC6H4C(O)S-κO,κS}]. This study provides the first definitive measurement of the Mo(V)=/--S bond distance in an unambiguously characterized oxosulfido-Mo(V) compound and supports the presence of a short (ca. 2.22 Å) Mo=/--S bond in VR-XnO. It also demonstrates that the Mo(V)=/--S moiety participates in radical-based reactions that are facilitated by the facile redox interplay of Mo and S and by substrates susceptible to radical eliminations.

Optical properties of cerium doped oxyfluoroborate glass.

Cerium doped oxyfluoroborate glasses have been prepared and its spectroscopic properties have been discussed. It is found that the absorption edge shifts towards the lower energy side for the higher concentration of cerium dopant. Optical band gap for these glasses have been calculated and it is found that the number of non-bridging oxygen increases with cerium content. The emission spectra of these glasses have been recorded using UV laser radiations (266 and 355 nm) and it is observed that these glasses show bright blue emission. On the basis of excitation and emission spectra we have reported the existence of at least two different emission centers of Ce(3+)ions.