Development of efficient digestion procedures for quantitative determination of cobalt and molybdenum catalyst residues in carbon nanotubes

Whatever the method used for the synthesis of carbon nanotubes (CNTs), they always contain residual catalysts in variable amount. Many methods have been proposed in the literature to purify CNTs, but their efficiency strongly depends on the experimental conditions. Although the presence of residual catalysts in small amount is generally not a problem for many applications, this can become a critical issue when a high purity is required, typically for magnetic properties or for biomedical applications (because of the intrinsic toxicity of most catalysts). Quantification of the amount of residual catalysts is usually obtained by classical chemical analysis, which requires a preliminary digestion (complete mineralisation) of the CNT samples. In this work, we systematically compared 3 different digestion protocols and optimised one, reaching 100% dissolution within a very limited time (1 h) together with the requirement of only a few milligrams of sample, and safe experimental conditions. This method can be easily transferred for use in research laboratories, making accessible the quantitative analysis of CNT samples, and has been validated following ISO/ IEC 17025:2005 for linearity, specificity, intermediate precision, limits of detection and quantification

Reply to Ben-Dor and Barkai: A low Zn isotope ratio is not equal to a low Zn content

However, we are afraid that there was a misunderstanding in the interpretation of our data. Ben-Dor and Barkai (2) wrote that "One explanation presented in the [our] paper was that Neandertals may have consumed body parts and animals that were relatively poor in zinc, like the liver or deer." This sentence is not reflecting our conclusions: We discussed Zn isotope ratios (i.e., 66Zn/64Zn ratio expressed as a δ66Zn value) and not Zn concentrations. To explain low δ66Zn values of the Neandertal tooth, we propose that Neandertals ate food items depleted in heavy Zn isotopes (and therefore enriched in light Zn isotopes), but those foods can have variable Zn contents, independent of the Zn isotope composition as such

Social disparities in food preparation behaviours: a DEDIPAC study

BACKGROUND: The specific role of major socio-economic indicators in influencing food preparation behaviours could reveal distinct socio-economic patterns, thus enabling mechanisms to be understood that contribute to social inequalities in health. This study investigated whether there was an independent association of each socio-economic indicator (education, occupation, income) with food preparation behaviours. METHODS: A total of 62,373 adults participating in the web-based NutriNet-Santé cohort study were included in our cross-sectional analyses. Cooking skills, preparation from scratch and kitchen equipment were assessed using a 0-10-point score; frequency of meal preparation, enjoyment of cooking and willingness to cook better/more frequently were categorical variables. Independent associations between socio-economic factors (education, income and occupation) and food preparation behaviours were assessed using analysis of covariance and logistic regression models stratified by sex. The models simultaneously included the three socio-economic indicators, adjusting for age, household composition and whether or not they were the main cook in the household. RESULTS: Participants with the lowest education, the lowest income group and female manual and office workers spent more time preparing food daily than participants with the highest education, those with the highest income and managerial staff (P < 0.0001). The lowest educated individuals were more likely to be non-cooks than those with the highest education level (Women: OR = 3.36 (1.69;6.69); Men: OR = 1.83 (1.07;3.16)) while female manual and office workers and the never-employed were less likely to be non-cooks (OR = 0.52 (0.28;0.97); OR = 0.30 (0.11;0.77)). Female manual and office workers had lower scores of preparation from scratch and were less likely to want to cook more frequently than managerial staff (P < 0.001 and P < 0.001). Women belonging to the lowest income group had a lower score of kitchen equipment (P < 0.0001) and were less likely to enjoy cooking meal daily (OR = 0.68 (0.45;0.86)) than those with the highest income. CONCLUSION: Lowest socio-economic groups, particularly women, spend more time preparing food than high socioeconomic groups. However, female manual and office workers used less raw or fresh ingredients to prepare meals than managerial staff. In the unfavourable context in France with reduced time spent preparing meals over last decades, our findings showed socioeconomic disparities in food preparation behaviours in women, whereas few differences were observed in men

Manger à Rennes : l’alimentation des élites rennaises d’après les isotopes

International audienc

Adherence to the french eating model is inversely associated with overweight and obesity: results from a large sample of french adults

International audienceThe ‘French Eating Model’ characterised by structured meals and conviviality has received little attention, although it has been suggested as a potential explanation of the French paradox. This study aims at assessing the adherence to this model in French adults and whether it is associated with weight status. Eating behaviour and, in particular, number of meals per day, snacking frequency, meal time, meal duration, number of courses, position (standing, sitting), presence of others and pleasure experienced was assessed in 2014, in 47 219 participants of the NutriNet-Santé study. A global score of adherence to the French Eating Model was computed on the basis of eating behaviour components. Prevalence of the model was assessed on a sample weighted according to Census data. Associations between adherence to the model (and its components) and overweight and obesity were assessed using logistic regression analyses adjusted for individual characteristics. Most individuals followed the French Eating Model: three meals a day, at set times, sitting at a table with other people and considering meals as a moment of pleasure. Individuals who exhibited higher adherence to the model were less likely to be overweight (OR=0·89; 95 % CI 0·87, 0·92 or obese (0·76; 95 % CI 0·74, 0·79). Similar trends were found for the following components: number of meals per day, snacking frequency, meal time, meal duration and pleasure experience, whereas an opposite trend was observed for the eating with others component. Although prospective studies are needed to conclude on a causal relationship, these results suggested the potential role of the French Eating Model, which is still prevailing in France, in obesity prevention

Socio-economic, demographic, lifestyle and health characteristics associated with consumption of fatty-sweetened and fatty-salted foods in middle-aged French adults

Few studies have specifically focused on characteristics associated with consumption of combined fatty-salted and fatty-sweetened foods, whereas their identification could be useful for defining effective public health measures. The aim of the present study was to investigate the association between demographic, socio-economic, lifestyle and health characteristics and consumption of these types of food in a general sample of French adults. Dietary intake was assessed using a minimum of six 24 h dietary records collected over a 2-year period in 6240 subjects aged 35-60 years who participated in the Supplémentation en VItamines Minéraux et AntioXydants cohort study. Associations of individual characteristics with high and intermediate consumption of fatty-sweetened and fatty-salted foods were assessed using multivariate polytomic logistic regression models. Risk of moderate or high consumption of fatty-salted foods decreased with increasing age. Current smokers, drinkers, individuals with overweight and with hypertension were more likely to consume moderate or high amounts of such foods. Risk of moderate or high consumption of fatty-sweetened foods decreased with increasing age. Women, individuals living as a couple, moderate drinkers and persons with low or medium physical activity level were more likely to consume moderate or high amounts of such foods. Lower educated subjects, current smokers, heavy drinkers and individuals with severe hypertriacylglycerolaemia were less likely to have moderate or high consumption. Consumption of fatty-sweetened and fatty-salted foods varied according to demographic, lifestyle and health characteristics. Common unhealthy behaviours such as smoking, low physical activity and alcohol drinking, associated with high consumption of these food groups, may help to effectively target public health efforts.info:eu-repo/semantics/publishe

Associations between motives for dish choice during home-meal preparation and diet quality in French adults: findings from the NutriNet-Santé study

A number of motives such as constraints or pleasure have been suggested to influence dish choices during home-meal preparation. However, no study has evaluated how the importance conferred to these motives potentially influence diet quality. The present study aims at investigating the difference in diet quality according to the importance attached by individuals to various dish choice motives. The importance of twenty-seven criteria related to dish choices on weekdays was evaluated among 48 010 French adults from the NutriNet-Sante study. ANCOVA and logistic regression models, adjusted for sociodemographic and lifestyle factors, were used to evaluate the association between the importance attached to dish choice motives (yes upsilon. no) and energy and food group intakes, as well as adherence to French nutritional guidelines (modified Programme National Nutrition Sante-Guideline Score (mPNNS-GS)). A higher adherence to nutritional guidelines was observed in individuals attaching importance to a healthy diet (mPNNS-GS score 7.87 (SD 0.09) upsilon. 7.39 (SD 0.09)) and specific diets (mPNNS-GS score 7.73 (SD 0.09) upsilon. 7.53 (SD 0.09)), compared with those who attached little/no importance (all P < 0.0001). These individuals also exhibited higher intakes of fruits and vegetables, but a lower consumption of meat, milk and cheese, sugary products and convenience foods compared with their respective counterparts (all P < 0.0001). For other motives, that is, constraints, pleasure and organisation, only small differences were observed. The main difference in diet quality was related to the importance placed on a healthy diet. Although a causal link should be demonstrated, our findings suggested that strategies aiming at enabling people to take into account diet quality during home-meal preparation might be effective levers to promote healthy eating

Association of perception of front-of-pack labels with dietary, lifestyle and health characteristics

Objective: To identify patterns of perception of front-of-pack (FOP) nutrition labels and determine dietary, lifestyle and health profiles related to such patterns. Design: Cross-sectional. Participants/Setting: 28,952 French adults participating in the web-based Nutrinet-Sante cohort. Outcome measures: Perception was measured using indicators of understanding and acceptability for three simple FOP labels ("green tick'', the logo of the French Nutrition and Health Program and "simple traffic lights'' (STL)), and two detailed FOP formats ("multiple traffic lights'' (MTL) and "color range'' logo (CR)), placed on ready-to-eat soup packages. Dietary intake data were collected using three web-based 24 h records. Statistical analyses: Associations of perception patterns with individual characteristics, including diet, lifestyle and health status, were examined using analysis of covariance and logistic regression, adjusted for socio-demographic and economic factors. Results: No clear trend emerged concerning differences in dietary intake between perception groups. Low physical activity and obesity were more frequent in the 'favorable to STL' group (respectively, 20.7% and 10.7%). The 'favorable to MTL' group included the highest percentage of individuals who declared type 2 diabetes (2.2%). Persons with hypertension were proportionally more numerous in the 'favorable to MTL' and the 'favorable to CR logo' groups (respectively, 9.5% and 9.3%). Conclusions: After adjustment for socio-demographic and economic factors, no FOP label stood out as being more suitable than another for reaching populations with poor diet. However, both STL and MTL may be most appropriate for increasing awareness of healthy eating among groups at higher risk of nutrition-related chronic diseases