107 research outputs found
Ălaboration d'encres biosourcĂ©es pour un procĂ©dĂ© industriel de dĂ©coration de verres de table
Dans un contexte dâĂ©volution de la lĂ©gislation et de la conscience environnementale des consommateurs, Arc International et Ferro visent le remplacement du bisphĂ©nol A, une substance considĂ©rĂ©e comme cancĂ©rigĂšne, mais nĂ©cessaire Ă lâĂ©laboration des encres actuellement utilisĂ©es pour la dĂ©coration industrielle de verres de table. Le projet a pour but la formulation dâune encre alternative issue de ressources biosourcĂ©es disponibles commercialement. Elle devra sâapprocher de lâencre dâorigine en termes de stockage, de compatibilitĂ© avec le procĂ©dĂ© de dĂ©coration par sĂ©rigraphie, et de propriĂ©tĂ©s finales, notamment la rĂ©sistance Ă la rayure et au lave-vaisselle.
La recherche sâest divisĂ©e en deux grands axes : le changement de la mĂ©thode de polymĂ©risation avec lâimplication de nouveaux produits, et le remplacement des composants des systĂšmes Ă©poxydes/durcisseurs actuels. Un axe mineur concernant lâutilisation de polyhydroxybutyrate (PHB) comme charge de renfort fut Ă©galement Ă©tudiĂ©.
En dĂ©pit de son haut taux de biosourcĂ©, la polymĂ©risation par auto-oxydation dâhuiles vĂ©gĂ©tales et de ses dĂ©rivĂ©s nâa pas aboutie. Lui sont reprochĂ©s de trop faibles performances finales, notamment en termes de duretĂ© et de coloration, ainsi que la libĂ©ration de fumĂ©es irritantes. A lâaide de propoxide de zirconium et de composĂ©s huileux Ă©poxydĂ©s, la polymĂ©risation sol-gel a conduit Ă de meilleures performances, mais nâa cependant pas permis dâatteindre les prĂ©requis de duretĂ© Ă©dictĂ©s par Arc. De mĂȘme, dans le cadre de la meilleure formulation faisant intervenir du cardanol Ă©poxydĂ© (NC-514), la flexibilitĂ© et la coloration sont trop importantes pour que le dĂ©veloppement dâune encre soit envisageable.
Le remaniement de la composition des systĂšmes Ă©poxydes/durcisseurs constitue la seconde Ă©tape des travaux de recherche. Pour la partie Ă©poxyde, les huiles vĂ©gĂ©tales Ă©poxydĂ©es (Vikoflex) nâaboutissent pas Ă des films exploitables : trop flexibles, liquides quand rĂ©ticulĂ©s avec des amines, gĂ©nĂ©rateurs de fumĂ©es, rĂ©tractation, etc. Leur importante densitĂ© de chaines aliphatiques est pointĂ©e comme la principale raison de leur flexibilitĂ© et de leur manque de rĂ©activitĂ©. Une huile phĂ©nolique Ă©poxydĂ©e (NC-514) a en revanche permis dâobtenir des films aux propriĂ©tĂ©s intĂ©ressantes : duretĂ© et bel aspect de surface, en dĂ©pit dâune faible rĂ©sistance Ă lâeau et aux solvants, ainsi quâune coloration prononcĂ©e. Pour la partie durcisseur, deux gammes biosourcĂ©es ont Ă©tĂ© testĂ©es : les dĂ©rivĂ©s dâacides gras Pripol et Priamine, et les phenalkamines NX-2009 et Lite-2002LP. Pripol et Priamine ont conduit Ă des films trop flexibles, tandis que les phenalkamine ont permis lâobtention de bonnes duretĂ©s. Ces durcisseurs se rejoignent nĂ©anmoins sur leur faible rĂ©sistance Ă lâeau et aux solvants, et des problĂšmes de rĂ©activitĂ© ont contraint leur abandon. LâĂ©tude sâest rĂ©orientĂ©e vers le dicyandiamide, un durcisseur actuellement utilisĂ© par Ferro, et qui se dĂ©marque de par son profil de rĂ©activitĂ© atypique et compatible avec la formulation dâencres mono-composant.
Enfin, le PHB nâa pas eu les effets bĂ©nĂ©fiques escomptĂ©s sur les formulations, car en plus de rĂ©duire significativement la duretĂ© des films, il augmentait la viscositĂ© des formulations et compliquait leur application.
Au final, une formulation alliant NC-514 et dicyandiamide pour un taux de biosourcé de 91.7% a été formulée. Malgré sa résistance chimique moyenne et sa coloration légÚrement prononcée, sa dureté et son bel aspect de surface la positionnent comme une alternative viable aux encres actuelles, ce que les futurs tests industriels planifiés par Ferro se chargeront de vérifier.
----------
In a context of legislation changes and rising environmental awareness, Arc International and Ferro aim at the replacement of the bisphenol A, considered as carcinogen, found in the inks used for the industrial decoration of glasses. Their goal is to formulate a biobased ink coming from commercially available resources, which could compete with the current inks in terms of storage, compatibility with the screen printing process and performances, especially in terms of hardness and dishwasher resistance.
The task has been divided in two major axes: the replacement of the polymerization method with the implication of new products, and the substitution of the components involved in the current epoxy/hardener systems. A minor lead was the study of polyhydroxybutyrate (PHB) as reinforcing fillers.
Despite its high biobased content, thermal polymerization of drying oils and its derivatives ended into flexible and colored films, aside from the emission of acrid smoke during the curing process. Sol-Gel polymerization led to better results, but still too flexible regarding the expectations of Arc. Even with the best formulation involving epoxidized cardanol and zirconium propoxide, both hardness and coloration impeded its use as an alternative.
Reworking of the current epoxy/hardener systems constituted the second part of the task. For the epoxy part, epoxidized vegetable oils led to poor hardness, low reactivity with amines, acrid fumes, and retraction. Their high density of aliphatic chains is pointed out as the major reason for their flexibility and their lack of reactivity. In the other hand, an epoxidized phenolic oil (NC-514) successfully led to interesting properties: hardness, and good surface appearance, in spite of a relative water and MEK sensitivity and a noticeable coloration. For the hardener part, two biobased product ranges were tested: fatty acid derivatives Pripol and Priamine, and phenalkamine NX-2009 and Lite-2002LP. Pripol and Priamine resulted in flexible films, while phenalkamine showed good hardness. Unfortunately, both hardeners had water and solvents sensitivity, and their unconventional reactivity constrain the project to abandon them. Thus the study reoriented to dicyandiamide, which is currently used by Ferro because of its atypical reactivity compatible with mono-component inks.
Regarding PHB, its inclusion in formulations resulted into the loss of hardness, and the increase in viscosity which caused complication during the application process.
At last, a formulation combining NC-514 and dicyandiamide with a 91.7% biobased rate has been proposed. Despite a low chemical resistance and a noticeable coloration, its hardness and its good surface appearance make it a strong alternative to the current inks, and the upcoming industrial tests planned by Ferro will clarify this point
Effect of weight loss on HDL-apoA-II kinetics in the metabolic syndrome
Reduced HDL (high-density lipoprotein) concentration in the MetS (metabolic syndrome) is associated with increased risk of cardiovascular disease and is related to defects in HDL-apoA-II (apolipoprotein A-II) kinetics. Dietary restriction is the most commonly used weight loss strategy. In the present study, we examined the effect of weight loss on HDL-apoA-II kinetics in men with the MetS at the start and end of a 16-week intervention trial of a hypocaloric low-fat diet (n=20) compared with a weight maintenance diet (n=15), using a stable isotope technique and compartmental modelling. The low-fat diet achieved a significant reduction (P<0.01) in BMI (body mass index), abdominal fat compartments and HOMA (homoeostasis model assessment) score compared with weight maintenance. Weight loss also significantly (P<0.05) decreased both the production rate (â23%) and FCR (fractional catabolic rate) (â12%) of HDL-apoA-II, accounting for a net decrease in apoA-II concentration (â9%). Reductions in the HDL-apoA-II production rate were significantly associated with changes in body weight (r=0.683, P<0.01), plasma triacylglycerols (triglycerides) (r=0.607, P<0.01) and, to a lesser extent, plasma insulin (r=0.440, P=0.059) and HOMA-IR (HOMA of insulin resistance) (r=0.425, P=0.069). Changes in the apoA-II FCR were also significantly associated with reductions in visceral adipose tissue mass (r=0.561, P=0.010). In conclusion, in obese men with the MetS, short-term weight loss with a low-fat low-caloric diet lowers plasma apoA-II concentrations by decreasing both the production and catabolism of HDL-apoA-II. The cardiometabolic significance of this effect on HDL metabolism remains to be investigated further
Plasma proteome changes in cardiovascular disease patients: novel isoforms of apolipoprotein A1
<p>Abstract</p> <p>Background</p> <p>The aim of this proteomic study was to look for changes taking place in plasma proteomes of patients with acute myocardial infarction (AMI), unstable angina pectoris (UAP), and stable angina pectoris (SAP).</p> <p>Methods</p> <p>Depleted plasma proteins were separated by 2D SDS-PAGE (pI 4-7), and proteomes were compared using Progenesis SameSpots statistical software. Proteins were identified by nanoLC-MS/MS. Proteins were quantified using commercial kits. Apolipoprotein A1 was studied using 1D and 2D SDS-PAGE, together with western blotting.</p> <p>Results</p> <p>Reciprocal comparison revealed 46 unique, significantly different spots; proteins in 34 spots were successfully identified and corresponded to 38 different proteins. Discrete comparisons of patient groups showed 45, 41, and 8 significantly different spots when AMI, UAP, and SAP were compared with the control group. On the basis of our proteomic data, plasma levels of two of them, alpha-1 microglobulin and vitamin D-binding protein, were determined. The data, however, failed to prove the proteins to be suitable markers or risk factors in the studied groups. The plasma level and isoform representation of apolipoprotein A1 were also estimated. Using 1D and 2D SDS-PAGE, together with western blotting, we observed extra high-molecular weight apolipoprotein A1 fractions presented only in the patient groups, indicating that the novel high-molecular weight isoforms of apolipoprotein A1 may be potential new markers or possible risk factors of cardiovascular disease.</p> <p>Conclusion</p> <p>The reported data show plasma proteome changes in patients with AMI, UAP, and SAP. We propose some apolipoprotein A1 fractions as a possible new disease-associated marker of cardiovascular disorders.</p
Relationships between alcoholic beverages and cardiovascular risk factor levels in middle-aged men, the PRIME study
Circulating biomarkers may be unable to detect infection at the early phase of sepsis in ICU patients: the CAPTAIN prospective multicenter cohort study.
PURPOSE: Sepsis and non-septic systemic inflammatory response syndrome (SIRS) are the same syndromes, differing by their cause, sepsis being secondary to microbial infection. Microbiological tests are not enough to detect infection early. While more than 50 biomarkers have been proposed to detect infection, none have been repeatedly validated. AIM: To assess the accuracy of circulating biomarkers to discriminate between sepsis and non-septic SIRS. METHODS: The CAPTAIN study was a prospective observational multicenter cohort of 279 ICU patients with hypo- or hyperthermia and criteria of SIRS, included at the time the attending physician considered antimicrobial therapy. Investigators collected blood at inclusion to measure 29 plasma compounds and ten whole blood RNAs, and-for those patients included within working hours-14 leukocyte surface markers. Patients were classified as having sepsis or non-septic SIRS blindly to the biomarkers results. We used the LASSO method as the technique of multivariate analysis, because of the large number of biomarkers. RESULTS: During the study period, 363 patients with SIRS were screened, 84 having exclusion criteria. Ninety-one patients were classified as having non-septic SIRS and 188 as having sepsis. Eight biomarkers had an area under the receiver operating curve (ROC-AUC) over 0.6 with a 95% confidence interval over 0.5. LASSO regression identified CRP and HLA-DRA mRNA as being repeatedly associated with sepsis, and no model performed better than CRP alone (ROC-AUC 0.76 [0.68-0.84]). CONCLUSIONS: The circulating biomarkers tested were found to discriminate poorly between sepsis and non-septic SIRS, and no combination performed better than CRP alone
Apolipoprotein A-II Influences Apolipoprotein E-Linked Cardiovascular Disease Risk in Women with High Levels of HDL Cholesterol and C-Reactive Protein
Background: In a previous report by our group, high levels of apolipoprotein E (apoE) were demonstrated to be associated with risk of incident cardiovascular disease in women with high levels of C-reactive protein (CRP) in the setting of both low (designated as HR1 subjects) and high (designated as HR2 subjects) levels of high-density lipoprotein cholesterol (HDL-C). To assess whether apolipoprotein A-II (apoA-II) plays a role in apoE-associated risk in the two female groups. Methodology/Principal: Outcome event mapping, a graphical data exploratory tool; Cox proportional hazards multivariable regression; and curve-fitting modeling were used to examine apoA-II influence on apoE-associated risk focusing on HDL particles with apolipoprotein A-I (apoA-I) without apoA-II (LpA-I) and HDL particles with both apoA-I and apoA-II (LpA-I:A-II). Results of outcome mappings as a function of apoE levels and the ratio of apoA-II to apoA-I revealed within each of the two populations, a high-risk subgroup characterized in each situation by high levels of apoE and additionally: in HR1, by a low value of the apoA-II/apoA-I ratio; and in HR2, by a moderate value of the apoA-II/apoA-I ratio. Furthermore, derived estimates of LpA-I and LpA-I:A-II levels revealed for high-risk versus remaining subjects: in HR1, higher levels of LpA-I and lower levels of LpA-I:A-II; and in HR2 the reverse, lower levels of LpA-I and higher levels of LpA-I:A-II. Results of multivariable risk modeling as a function of LpA-I and LpA-I:A-II (dichotomized as highest quartile versus combined three lower quartiles) revealed association of risk only for high levels of LpA-I:A-II in the HR2 subgroup (hazard ratio 5.31, 95% CI 1.12-25.17, p = 0.036). Furthermore, high LpA-I: A-II levels interacted with high apoE levels in establishing subgroup risk. Conclusions/Significance: We conclude that apoA-II plays a significant role in apoE-associated risk of incident CVD in women with high levels of HDL-C and CRP
Profil des patients ùgés de plus de 65 ans en pré-hospitalier dans le département du Nord (étude rétrospective sur 1487 interventions SMUR au cours de 3 périodes de 2009)
LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF
Fibrates, Sequestrant Resines and HMG CoA Reductase Inhibitors and Lipoprotein Particles
- âŠ