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The synthesis and characterization of benzene- and p-toluenesulphonylhydrazones derived from salicylaldehyde and 2-hydroxy-1-naphthaldehyde and their Cu(II) complexes are reported. The compounds were characterized on the basis of elemental analyses, electronic and IR spectra, magnetic moments, and conductance measurements. The electrochemical behavior of the Cu(II) complexes was investigated in DMSO by cyclic voltammetry (CV), rotating disc electrode (RDE) and coulometry. The oxidative polymerization of the copper complexes on a glassy carbon electrode was carried out in DMSO.

OBJECTIVE: Knowledge on the time-course (trends) of work-related asthma (WRA) remains sparse. The aim of this study was to describe WRA trends in terms of industrial activities and the main causal agents in France over the period 2001-2009. METHOD: Data were collected from the French national network of occupational health surveillance and prevention (Réseau National de Vigilance et de Prévention des Pathologies Professionnelles (RNV3P)). Several statistical models (non-parametric test, zero-inflated negative binomial, logistic regression and time-series models) were used and compared with assess trends. RESULTS: Over the study period, 2914 WRA cases were included in the network. A significant decrease was observed overall and for some agents such as isocyanates (p = 0.007), aldehydes (p = 0.01) and latex (p = 0.01). Conversely, a significant increase was observed for cases related to exposure to quaternary ammonium compounds (p = 0.003). The health and social sector demonstrated both a growing number of cases related to the use of quaternary ammonium compounds and a decrease of cases related to aldehyde and latex exposure. CONCLUSIONS: WRA declined in France over the study period. The only significant increase concerned WRA related to exposure to quaternary ammonium compounds. Zero-inflated negative binomial and logistic regression models appear to describe adequately these data. [ABSTRACT FROM AUTHOR]

Thiourea derivatives namely, phenylthiourea (PTU), N, N′-diphenylthiourea (DPTU) and N-naphtyl N′-phenylthiourea (NPTU) synthesised in our laboratory, were tested as inhibitors for the corrosion of cold rolled steel in 1 M HClO4 using polarisation and electrochemical impedance measurements. At 30 °C, PTU and DPTU stimulated corrosion at low concentrations while addition of NPTU caused inhibition at all concentrations. The best protection (93%) was obtained by adding NPTU at 2.5 × 10−4 M. Polarisation curves showed that NPTU acted as a mixed inhibitor. The degree of surface coverage of the adsorbed inhibitors was determined by the ac impedance technique. The adsorption of NPTU on the cold rolled steel surface obeyed the Langmuir adsorption isotherm. Corrosion behaviour in the presence of NPTU at various concentrations was studied in the temperature range 20–50 °C. Both the corrosion rate of cold rolled steel and protection efficiency increased with increasing temperature. Activation energies with and without NPTU were obtained from the temperature dependence of corrosion current. The thermodynamic functions of the adsorption processes were calculated from the polarisation data and were used to analyse the inhibitor adsorption mechanism. [ABSTRACT FROM AUTHOR]

N, N′-Diphenylthiourea (DPTU) and N-naphthyl- N′-phenylthiourea (NPTU) synthesized in our laboratory, were tested as inhibitors for the corrosion of cold-rolled steel in 0.5 M H2SO4 by weight loss and electrochemical measurements. The studies clearly reveal that when we substitutes a phenyl group in N, N′-diphenylthiourea (DPTU) by naphthyl group to obtain N-naphthyl- N′-phenylthiourea (NPTU), the inhibition efficiency increases from 80 to 96% at 2 × 10−4 M. Polarization curves show that NPTU acts as mixed type inhibitor whereas DPTU predominates as cathodic inhibitor. Changes in impedance parameters (charge transfer resistance, R t, and double layer capacitance, C dl) were indicative of adsorption of DPTU and NPTU on the metal surface, leading to the formation of protective films. The degree of the surface coverage of the adsorbed inhibitors is determined by ac impedance technique, and it was found that the adsorption of these inhibitors on the cold-rolled steel surface obeys the Langmuir adsorption isotherm. The effect of the temperature on the corrosion behavior with addition of 10−4 M of DPTU and NPTU was studied in the temperature range 20–50 °C. Results show that the rate of corrosion of mild steel increased with increasing temperature both in the presence of inhibitors and in their absence. Activation energies in the presence and absence of DPTU and NPTU were obtained by measuring the temperature dependence of the corrosion current. The reactivity of these compounds was analyzed through theoretical calculations based on density functional theory to explain the different efficiency of these compounds as corrosion inhibitors. [ABSTRACT FROM AUTHOR]

N, N′-Diphenylthiourea (DPTU) and N-naphthyl- N′-phenylthiourea (NPTU) synthesized in our laboratory, were tested as inhibitors for the corrosion of cold-rolled steel in 0.5 M H2SO4 by weight loss and electrochemical measurements. The studies clearly reveal that when we substitutes a phenyl group in N, N′-diphenylthiourea (DPTU) by naphthyl group to obtain N-naphthyl- N′-phenylthiourea (NPTU), the inhibition efficiency increases from 80 to 96% at 2 × 10−4 M. Polarization curves show that NPTU acts as mixed type inhibitor whereas DPTU predominates as cathodic inhibitor. Changes in impedance parameters (charge transfer resistance, R t, and double layer capacitance, C dl) were indicative of adsorption of DPTU and NPTU on the metal surface, leading to the formation of protective films. The degree of the surface coverage of the adsorbed inhibitors is determined by ac impedance technique, and it was found that the adsorption of these inhibitors on the cold-rolled steel surface obeys the Langmuir adsorption isotherm. The effect of the temperature on the corrosion behavior with addition of 10−4 M of DPTU and NPTU was studied in the temperature range 20–50 °C. Results show that the rate of corrosion of mild steel increased with increasing temperature both in the presence of inhibitors and in their absence. Activation energies in the presence and absence of DPTU and NPTU were obtained by measuring the temperature dependence of the corrosion current. The reactivity of these compounds was analyzed through theoretical calculations based on density functional theory to explain the different efficiency of these compounds as corrosion inhibitors. [ABSTRACT FROM AUTHOR]

To analyze the health disparities relative to the prevalence of arterial hypertension and its therapeutic control in the active French population, in relation to occupational categories (OC), a population of 17 359 men and 12 267 women was assessed from January 1997 to April 1998. The initial phase was a cross-sectional analysis of a cohort study designed to assess the incidence of arterial hypertension in a French working population. Information was collected by the worksite physician during the annual examination. Blood pressure (BP) was measured using a validated automatic device. Among subjects with a BP > or =140/90 mm Hg, patients not treated with antihypertensive drugs were invited to have an additional BP measurement, 1 month later. Overall prevalence was 16.1% for men and 9.4% for women. Both prevalence and therapeutic control of high BP were related to OCs in this study. Prevalence of hypertension was higher and maintenance of therapeutic control lower among lower OCs. In contrast, awareness of high BP and the proportion of hypertensive subjects under current treatment were not related to OCs. Educational level and low OC were significantly related to prevalence of high BP after adjustment for obesity, excessive alcohol consumption, and sedentary lifestyle in women only. A poor BP control under treatment was related to high alcohol intake and low OC in men. In women only, however, low educational level was related to high prevalence of hypertension and poor BP control under antihypertensive treatment. Inequalities in hypertension prevalence persist, with prevalence being higher among lower OCs. Social disparities were not observed, however, in awareness of their condition among hypertensive subjects and among patients for receiving versus not receiving any treatment for hypertension. In contrast, BP control under antihypertensive treatment was lower among lower OCs.