Search

Les equipes prenant en charge un patient suspect de virose Ebola sont tenues au port d’equipements de protection individuelle (EPI) susceptibles d’entraver la dexterite des operateurs. L’objectif principal est d’etudier l’impact des EPI Ebola sur la difficulte et le delai de realisation des gestes d’urgence. Cette etude observationnelle monocentrique croisee incluait 22 medecins urgentistes, reanimateurs ou infirmiers — anesthesistes volontaires devant realiser cinq ateliers sur mannequin avec ou sans port d’EPI Ebola selon une sequence predeterminee: voie veineuse peripherique (VVP), catheter intraosseux (KTIO), intubation avec et sans Eschmann ou apres pose de LMA-Fastrach™. Le critere de jugement principal etait le delai de realisation des gestes techniques avec et sans port d’EPI. Le port de l’EPI n’augmente pas le taux d’echec de chaque geste technique mais augmente significativement les delais d’intubation simple (29 vs 36 secondes; p < 0,01), d’intubation avec Eschmann (38 vs 45 secondes; p = 0,03) et l’intubation au LMA-Fastrach™(39 vs 45 secondes; p < 0,001). Le port d’EPI Ebola augmentait la difficulte ressentie pour la pose d’abords vasculaires sans augmenter le taux d’echec ni modifier les delais de pose de VVP. Le recours au KTIO etait plus rapide que la pose de VVP sans (67 vs 88 secondes; p = 0,02) et avec tenue (78 vs 101 secondes; p < 0,01). Le port de l’EPI n’entraine qu’un impact modere sur la dexterite des gestes techniques en situation d’urgence. Ces resultats doivent etre confortes par des etudes cliniques.

A fast, simple and effective extraction method based on matrix solid phase dispersion (MSPD) was developed and validated for the simultaneous cleaning-up and quantitative extraction of illegal dyes (sudan I, sudan II, sudan III and sudan IV) from different sauces and condiments. Several parameters as sorbent, cleaning procedure to eliminate carothenoids and other interferences, and solvents for elution were evaluated to find the optimal MSPD conditions. The best results were obtained using a system containing washed sea sand and Florisil as sorbents and sodium sulphate as desiccant; hexane was used as defatted agent and acetonitrile as elution solvent. Quantitative analyses were performed by liquid chromatography (LC) with diode array detection (DAD). The chromatographic separation was performed on a Phenomenex Synergy Polar RP column with isocratic elution using methanol/acetonitrile/water 65/20/15, v/v/v, as the mobile phase at a flow rate of 1.0 mL min−1 and 30 °C of temperature. Under these conditions sudan I–IV recoveries were between 60% and 99% and relative standard deviations ranging from 2.0% to 10.0%. Limits of detection resulted five times lower than the values required by European regulations and were ranged between 0.05 and 0.09 μg g−1. The applicability of this MSPD–DAD method to determine illegal sudan dyes in sauce and condiment samples was demonstrated. This method has potential to be applied using a simple instrumentation present in most analytical laboratories.

The possible correlation between Hammett’s constant (σp), a characteristic parameter of functional groups with electrodonating or electroaccepting properties, and two indices of global reactivity were calculated in the gas phase. Parameters associated to a set of 22 structural variants of isatoic anhydride (2H–3, 1–benzoxazin–2,4(1H)–dione, ISA), replaced with diverse functional groups, were explored applying linear and quadratic statistical models for numerical analysis of the results.

A selective on-column molecularly imprinted solid-phase extraction (MISPE) for ethynylestradiol (EE2) from water samples was developed. Following a non-covalent molecular imprinting approach, two molecularly imprinted polymers (MIPs) have been synthesised using methacrylic acid (MAA) as functional monomer, ethyleneglycol dimethacrylate (EGDMA) as crosslinker and EE2 as template, in two different polymerisation solvents (acetonitrile or toluene). The optimisation of the on-column MISPE conditions for the selective rebinding of the EE2 resulted in a flow rate of 2.3 mL min(-1) and volumes of 1 mL toluene and 1.5 mL methanol-acetic acid (9:1) for washing and elution steps, respectively. The selectivity of the imprinted polymer towards several related estrogens such as estriol (E3), estrone (E1) and estradiol (E2) was evaluated. The recovery of EE2 from a 50-mL spiked river-water sample was 75% when the optimised on-column MISPE was applied.

[EN] The current socioeconomic conditions require highly educated professional with new curricula requirements and new skills, professionals with initiative and abilities able to be adapted to different situations and contexts. Consequently, the university education system must ensure that students achieve competences that involve the combination of knowledge, attitudes and values that enable a qualified person to undertake the resolution of problems or able to evolve in a new professional or social context. To achieve this goal, universities must find and use the most suitable tools to adapt and create higher education programs to respond to the needs of today’s society, tuning academic and professional profiles. On the other hand, there is a significant growth of enrolling students in distance education universities and several distance education programs are available in most universities. Thus, the aim of this communication is to share the results obtained during the development of a teaching innovation project, which assessed interdisciplinary, specific and transversal competences, by means of a post-task objective test, in the Chemistry undergraduate studies at the National University of Distance Education, (UNED) of Spain. The results of this study have allowed to the professors board to analyse and assess the competences acquired by the students, pointing out the main deficiencies to be solved by re-designing the teaching activities and methodologies to ensure a complete success.

Doping effects are analyzed by means of the ab initio perturbed ion (aiPI) method via substitution of the fluorides and oxides of zirconium, hafnium, and thorium. Lattice relaxation is simulated through the calculation of vibrational breathing modes and substitutional effects on the compound are thereby analyzed. In addition, the band gaps (in the pure species) and impurity levels (where substitutional ions Pr+4 and Yb+3 are considered in the doped species) of the fluorides are estimated via the transition energy calculated at the aiPI-optimized geometry of the pure and doped crystal clusters by means of the configuration interaction with single excitations (CIS) method that accounts for electronic correlation. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004

An algebraic approach is proposed to calculate the Franck–Condon factors for the Morse potential of diatomic molecules. The Morse oscillator is approximated by means of a fourth-order anharmonic oscillator. In the second-quantized formalism, this anharmonic Hamiltonian is diagonalized by way of the Bogoliubov–Tyablikov transformation. The Franck–Condon factors are estimated using the harmonic frequency equivalent and the recurrence relations for the Franck–Condon factors of the harmonic oscillator. Overlap integrals are shown for three band systems and compared with values calculated with an RKR potential. Excellent agreement is achieved.

The estrogenic compound diethylstilbestrol (DES) is widely studied because of its potential endocrine disruption effects. The prohibition of the use of diethylstilbestrol as a growth promoter has not been enough to ensure the total disappearance of this compound from environmental matrices. Due to the low levels of DES present in the environment, preconcentration and clean up methods are necessary for its analysis. This paper describes the synthesis and use of a molecularly imprinted polymer (MIP) as sorbent for on-column solid-phase extraction of DES from aqueous samples. The selectivity of the DES-MIP was evaluated towards several selected estrogens such as hexestrol (HEX), estrone (E1), estriol (E3), estradiol (E2) and ethynylestradiol (EE2). HPLC-DAD was used to quantify all analytes at 230-nm wavelength. The method has been successfully applied to the analysis of DES in spiked river and tap water samples, with recoveries of 72% and 83% respectively.

The steroidal compound 17β-estradiol (E2) is a major estrogen now widely studied because of its potential endocrine disruption effects. The present paper describes a simple, rapid, flow injection (FI) method for the fluorimetric determination of β-estradiol involving a molecularly imprinted polymer (MIP) packed into a microcolumn. Microwave-assisted extraction, a relatively new technique, was used to help remove the template from the MIP; this improved extraction efficiency. The optimization of the FI parameters and the intrinsic fluorescence of β-estradiol allowed its direct determination without a derivatization step. When the possible interference of other estrogens was examined, the system displayed excellent specificity for β-estradiol; no response to the natural estrogens estrone and estriol and the xenoestrogen bisphenol A was recorded. Under optimum experimental conditions, linear calibration graphs were obtained from 4 to 80 μg L-1 with a detection limit of 1.12 μg L-1. © The Royal Society of Chemistry 2005.

A spectrofluorimetric method is proposed for the determination of gallium with 1-(2-pyridylazo)-2-naphthol as derivative reagent in sodium dodecyl sulphate micellar medium. Sensitivity is increased by a factor of 20 with respect to that obtained in 20% ethanol medium. The stoichiometry of the complex is 1∶1. Optimum working conditions are about pH 4, 0.3% sodium dodecyl sulphate and absence of ethanol. The calibration graph is linear in the range 5–400 ppb of Ga(III) with a variation coefficient of 1.5% at 210 ppb of Ga for 10 replicates, and detection limit is 0.8 ppb. Main interferences are from copper and cobalt. Results obtained in the determination of Ga(III) in urine and aluminium samples show the validity of the method proposed.

A study of the chemiluminscent behaviour of quinolinic hydrazide (QH) is carried out, proposing a possible mechanism of reaction of QH and hydrogen peroxide in presence, or not, of fluorescein. An application of this reaction is done for the determination of H2O2 in commercial milk.

Aqueous solutions of Rose Bengal B contain four ionic species: H3R+ at Ho –4.75, pH 4.05. The pK for these equilibria in the pH zone are pK1= 3.51 and pK2= 4.05 and in the acid function (Hammet function) pKa1. Polymeric species and excimers have been found in the ground and in first excited state, respectively, at concentrations higher than 10–4M. Pt(IV) reacts with Rose Bengal B giving a colourless solution that does not show any fluorescence. Platinum(IV) has been determined fluorimetrically at concentrations higher than 0.2 p.p.m. The other noble metals do not interfere.