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The memory of crystalline phase in the melt of isotactic polypropylene (iPP) in regiodefective samples of iPP characterized by different concentrations regiodefects, constituted by secondary 2,1 propene units, is studied. The self‐nucleation (SN) experiments have demonstrated that the presence of 2,1 regiodefects produces a strong memory of the crystalline phase in the melt that persists up to temperatures much higher than the melting temperature. The extension of the heterogeneous melt (domain II) containing self‐nuclei increases with increasing the concentration of regiodefects. The higher the concentration of regiodefects the higher the temperature at which the self‐nuclei are dissolved and the homogeneous melt is achieved. This demonstrates that a strong memory of the crystalline phase of iPP in the melt exists not only in copolymers with noncrystallizable bulky comonomeric units rejected from the crystals but even when small defects are largely included in the crystals. [ABSTRACT FROM AUTHOR]

The mechanisms for the formation of N‐substituted hydrazones by coupling of alcohols and hydrazine, achieved by the sequential processes of acceptorless dehydrogenation and borrowing hydrogen, has been unveiled by density functional theory (DFT) calculations. The release of water and molecular hydrogen as subproducts, combined with the Mn‐PNN pincer based catalyst describe a green environment. Mechanistically, apart from describing a complex system of three coupled catalytic pathways, calculations describe the pivotal role of two intermediates, which participate in two catalytic pathways each one. Finally, predictive catalysis plays the role to push forward this reaction toward milder conditions, and thus in line with green chemistry standards. [ABSTRACT FROM AUTHOR]

A study of the structure and morphology of diblock copolymers composed of crystallizable blocks of polyethylene (PE) and syndiotactic polypropylene (sPP) having different lengths is reported. In both analyzed samples, the PE block crystallizes first by cooling from the melt (at 130 °C) and the sPP block crystallizes after at a lower temperature. Small angle X-ray scattering (SAXS) recorded during cooling showed three correlation peaks at values of the scattering vector, q1 = 0.12 nm−1, q2 = 0.24 nm−1 and q3 = 0.4 nm−1, indicating development of a lamellar morphology, where lamellar domains of PE and sPP alternate, each domain containing stacks of crystalline lamellae of PE or sPP sandwiched by their own amorphous phase of PE or sPP. At temperatures higher than 120 °C, when only PE crystals are formed, the morphology is defined by the formation of stacks of PE lamellae (17 nm thick) alternating with amorphous layers and with a long period of nearly 52 nm. At lower temperatures, when crystals of sPP are also well-formed, the morphology is more complex. A model of the morphology at room temperature is proposed based on the correlation distances determined from the self-correlation functions extracted from the SAXS data. Lamellar domains of PE (41.5 nm thick) and sPP (8.2 nm thick) alternate, each domain containing stacks of crystalline lamellae sandwiched by their own amorphous phase, forming a global morphology having a total lamellar periodicity of 49.7 nm, characterized by alternating amorphous and crystalline layers, where the crystalline layers are alternatively made of stacks of PE lamellae (22 nm thick) and thinner sPP lamellae (only 3.5 nm thick). [ABSTRACT FROM AUTHOR]

Abstract: Glycol ethers (GE) are a family of solvents, the use of which has increased dramatically since the 60''s, in domestic and occupational mainly water-based products, such as paintings, inks, varnishes, cleaning agents. There are two subgroups: E series and P series. EGME, among the E series, is the reference substance. This is a reprotoxic chemical causing infertility and genital apparatus atrophy on both sexes, embryofetal toxicity through maternal exposure (malformation, growth alterations and functional deficits). European Union has classified nine other GE as reprotoxic. P series, with the beta isomers exception, has no specific reprotoxicity. Epidemiological studies published from the 80''s onwards, have confirmed animal data (malformation, oligoazoospermia, spontaneous abortion, hypofertility). The effects can be observed even after the end of exposure. Risk assessment studies tend to prove that this massive exposure during several decades could have had an important impact on reproductive human health. Even if this exposure has considerably decreased since the last few years, a ban of reprotoxic GE, as required by two official bodies (CSC, CSHPF), seems necessary, due to the high risk level. Classification should be completed for some GE, not classified now (EGBE). Health assessment of past exposure should be carried out. Physicians should look after a possible glycol ethers responsibility when facing this kind of reprotoxic effects. [Copyright &y& Elsevier]

Glycol ethers (GE) are chemicals used since the 1930s as solvents in paints, inks, varnishes, and cleaning agents, mainly in water-based products, cosmetics, and drugs. World production approximates 1 million tons. Nineteen GE are produced or imported each year; over 1000 tons in European Union (EU) have been classified as high production volume chemicals (HPVCs). First animal data were published in 1971 and 1979 showing severe reprotoxicity for some GE. Two alerts were launched in the United States in 1982 and 1983, but the first partial GE regulation only occurred in 1993 in the EU. Although these chemicals may expose a very large population, basic toxicity data, more especially carcinogenicity, are still lacking (3/32 GE). However, experimental data were sufficient to lead developmental toxicity risk assessment since the early 1980s. Risk indices over 1000 have been calculated for consumers and workers exposed to reprotoxic GE in domestic and industrial activities. The first ban was decided in 1999 in France, but was only for drugs and cosmetics. Not surprisingly, since the late 1980s, human studies have found results similar to those in animal data: spontaneous abortions, malformations, testicular toxicity, and hematotoxicity. Despite this highly coherent set of data, and although substitution products are available, reprotoxic GE have been and still remain widely used in the world. The case of GE shows the failure of the present system based on a posteriori risk assessment. This pleads for the change of paradigm through the European REACH regulation based on the “No data, no market” principle. Ethics in REACH management should also be considered. [ABSTRACT FROM AUTHOR]

There is a lack of data on environmental benzene exposure in children. In this study, we compared personal benzene exposure and inhalation uptake in a group of children to those of their parents. We also compared levels of urinary benzene metabolites, trans,trans-muconic acid (MA) and hydroquinone (HQ), for those two groups, and assessed the correlation between personal benzene exposure and urinary MA and HQ concentrations. The study was performed on 21, 2–3-year-old children and their parents recruited on a voluntary basis among non-smokers from the three largest day-care centers of the town of Rouen in France. Average benzene concentrations were measured over 5 consecutive days with diffusive samplers. The following simultaneous measurements were carried out: personal exposure of the parents, concentrations inside and outside the day care centers, and inside the volunteer''s bedrooms. Morning and evening urine samples were collected during the same period. Benzene personal exposure levels were 14.4±7.7 μg/m3 and 11.09±6.15 μg/m3 in parents and children, respectively. Benzene inhalation uptake estimates were 2.51±1.23 μg/kg/day in the group of parents and 5.68±3.17 μg/kg/day in the group of children. Detectable levels of MA and HQ were found in 85% and 100% of the samples, respectively. Intra-individual variation of urinary MA and HQ concentrations expressed as a coefficient of variation (CV) ranged from 63 to 232% and from 13 to 144%, respectively. Mean values of MA and HQ (in mg/g creatinine) were 1.6- and 1.8-fold higher in the group of children than in the group of parents (P=0.008 and P<0.0001, respectively). Significant correlations between metabolites levels and benzene were not found. [Copyright &y& Elsevier]

Crystallization and phase separation in the melt in semicrystalline block copolymers (BCPs) compete in defining the final solid state structure and morphology. In crystalline–crystalline di-block copolymers the sequence of crystallization of the two blocks plays a definitive role. In this work we show that the use of epitaxial crystallization on selected crystalline substrates allows achieving of a control over the crystallization of the blocks by inducing crystal orientations of the different crystalline phases and a final control over the global morphology. A sample of polyethylene-block-syndiotactic polypropylene (PE-b-sPP) block copolymers has been synthesized with a stereoselective living organometallic catalyst and epitaxially crystallized onto crystals of two different crystalline substrates, p-terphenyl (3Ph) and benzoic acid (BA). The epitaxial crystallization on both substrates produces formation of highly ordered morphologies with crystalline lamellae of sPP and PE highly oriented along one direction. However, the epitaxial crystallization onto 3Ph should generate a single orientation of sPP crystalline lamellae highly aligned along one direction and a double orientation of PE lamellae, whereas BA crystals should induce high orientation of only PE crystalline lamellae. Thanks to the use of the two selective substrates, the final morphology reveals the sequence of crystallization events during cooling from the melt and what is the dominant event that drives the final morphology. The observed single orientation of both crystalline PE and sPP phases on both substrates, indeed, indicates that sPP crystallizes first onto 3Ph defining the overall morphology and PE crystallizes after sPP in the confined interlamellar sPP regions. Instead, PE crystallizes first onto BA defining the overall morphology and sPP crystallizes after PE in the confined interlamellar PE regions. This allows for discriminating between the different crystalline phases and defining the final morphology, which depends on which polymer block crystallizes first on the substrate. This work also shows that the use of epitaxial crystallization and the choice of suitable substrate offer a means to produce oriented nanostructures and morphologies of block copolymers depending on the composition and the substrates. [ABSTRACT FROM AUTHOR]

Objective: to know the perception of the nursing team about the factors involved in adherence and abandonment of tuberculosis treatment. Method: qualitative, descriptive-exploratory study carried out at the Tuberculosis Reference Center in the city of Porto Alegre, in Rio Grande do Sul. Nine nursing professionals responded to the semistructured interview and Bardin's content analysis was carried out. Results: four thematic categories were identified: the organization of the service and the role of the nursing team in the work process; the social root of tuberculosis; nursing consultation as a device for strengthening treatment adherence; service network as a strategy to reduce treatment abandonment. Conclusion: nursing professionals recognize their responsibility in the adherence to the treatment of tuberculosis and perceive the factors that influence abandonment in their daily work. They recognize the need for a networked, intersectoral, and of social protection effort to control the disease. [ABSTRACT FROM AUTHOR]

Background: Reducing health inequalities involves the identification and characterization of social and exposure factors and the way they accumulate in a given area. The areas of accumulation then allow for prioritization of interventions. The present study aims to build spatial composite indicators based on the aggregation of environmental, social and health indicators and their inter-relationships. Method: Preliminary work was carried out firstly to homogenize spatial coverage, and secondly to study spatial variation of environmental (EI), socioeconomic (SI) and health (HI) indicators. The aggregation of the different indicators was performed using several methodologies for which results and decision-makers' usability were compared. Results: Four methodologies were tested: 1) A simple summation of normalized HI, EI and SI indicators (IC), 2) the sum of the normalized HI, EI and SI indicators weighted by the first principal component of a Principal Component Analysis (IC PCA), 3) the sum of normalized and weighted indicators of the first principal component of Local Principal Component Analysis (IC LPCA), and 4) the sum of normalized and weighted indicators of the first principal component of a Geographically Weighted Principal Component Analysis (IC GWPCA). Conclusion: The GWPCA is particularly adapted to taking into account the spatial heterogeneity and the spatial autocorrelation between SI, EI and HI. This approach invalidates the basic assumptions of many standard statistical analyses. Where socioeconomic indicators present high deprivation and where they are associated with potential modifiable health determinants, decision-makers can prioritize these areas for reducing inequalities by controlling the socioeconomic and health determinants. [ABSTRACT FROM AUTHOR]

Background: Reducing health inequalities involves the identification and characterization of social and exposure factors and the way they accumulate in a given area. The areas of accumulation then allow for prioritization of interventions. The present study aims to build spatial composite indicators based on the aggregation of environmental, social and health indicators and their inter-relationships. Method: Preliminary work was carried out firstly to homogenize spatial coverage, and secondly to study spatial variation of environmental (EI), socioeconomic (SI) and health (HI) indicators. The aggregation of the different indicators was performed using several methodologies for which results and decision-makers’ usability were compared. Results: Four methodologies were tested: 1) A simple summation of normalized HI, EI and SI indicators (IC), 2) the sum of the normalized HI, EI and SI indicators weighted by the first principal component of a Principal Component Analysis (IC PCA), 3) the sum of normalized and weighted indicators of the first principal component of Local Principal Component Analysis (IC LPCA), and 4) the sum of normalized and weighted indicators of the first principal component of a Geographically Weighted Principal Component Analysis (IC GWPCA). Conclusion: The GWPCA is particularly adapted to taking into account the spatial heterogeneity and the spatial autocorrelation between SI, EI and HI. This approach invalidates the basic assumptions of many standard statistical analyses. Where socioeconomic indicators present high deprivation and where they are associated with potential modifiable health determinants, decision-makers can prioritize these areas for reducing inequalities by controlling the socioeconomic and health determinants. [ABSTRACT FROM AUTHOR]

Abstract: Analyzing the relationship between the environment and health has become a major focus of public health efforts in France, as evidenced by the national action plans for health and the environment. These plans have identified the following two priorities: [-] identify and manage geographic areas where hotspot exposures are a potential risk to human health; and [-] reduce exposure inequalities. The aim of this study is to develop a spatial stochastic multimedia exposure model for detecting vulnerable populations and analyzing exposure determinants at a fine resolution and regional scale. A multimedia exposure model was developed by INERIS to assess the transfer of substances from the environment to humans through inhalation and ingestion pathways. The RESPIR project adds a spatial dimension by linking GIS (Geographic Information System) to the model. Tools are developed using modeling, spatial analysis and geostatistic methods to build and discretize interesting variables and indicators from different supports and resolutions on a 1-km2 regular grid. We applied this model to the risk assessment of exposure to metals (cadmium, lead and nickel) using data from a region in France (Nord-Pas-de-Calais). The considered exposure pathways include the atmospheric contaminant inhalation and ingestion of soil, vegetation, meat, egg, milk, fish and drinking water. Exposure scenarios are defined for different reference groups (age, dietary properties, and the fraction of food produced locally). The two largest risks correspond to an ancient industrial site (Metaleurop) and the Lille agglomeration. In these areas, cadmium, vegetation ingestion and soil contamination are the principal determinants of the computed risk. [Copyright &y& Elsevier]

Exposure to airborne pollutants can result in adverse health effects. Acute symptoms can for instance comprise of irritation of the eyes or of the respiratory tract (called sensory irritation). In a recent case, health problems were reported in a French school and supposedly attributed to the presence of airborne irritant pollutants. Based on measured concentrations, the risk of developing the described health effects was assessed.Numerous airborne sensory irritants (aldehydes, organic acids, volatile organic compounds (VOCs), SO2, NH3) were identified and quantified in the indoor air by using active and passive sampling and online monitoring techniques. Reference values based on toxicological properties of compounds (sensory irritants) were taken from the literature. If not available, tentative values were specially developed for this purpose. Concentrations of all sensory irritants remain below their corresponding guideline values and are comparable to literature data. It was concluded that the risk of developing sensory irritation due to the presence of the studied compounds is negligible. This holds both for individual compounds and for the mixture of studied compounds. Limitations of the employed sampling strategy, and of existing sampling and analytical techniques, which do not allow for analysing more reactive compounds—which are strong sensory irritants—may play a role. New sampling techniques need to be developed. Psychosocial factors (group behaviour, increased attention to sensory irritation) should also be taken into account when dealing with health complaints on sensory irritation. [Copyright &y& Elsevier]