Resin-modified glass ionomers (RMGI) set by at least 2 mechanisms dependent upon reactant diffusion prior to gelation. Each reaction’s kinetics and setting mechanism may rely on and/or compete with ...the other. In this study, we investigated RMGI setting reaction interactions using differential scanning calorimetry (DSC) by varying light-cure initiation times. A RMGI was analyzed with isothermal and dynamic temperature scan DSC with light-curing occurring immediately, or at 5 or 10 minutes after mixing as well as without light-activation. Results show that as time allowed for the acid-base reaction increased, the light-activation polymerization exotherm decreased. Conversely, analysis of DSC data suggests that earlier light-activation may limit the acid-base reaction and result in a different structured material. During early RMGI development, acid-base and light-polymerization reactions compete with and inhibit one another.
The degradation pathway of ethylene–vinyl acetate copolymers and their nanocomposites is investigated using TGA/FT-IR, TGA, GC–MS, cone calorimetry and UV techniques to determine if the presence of ...the clay has an effect on the degradation pathway. The first step of the degradation, the loss of acetic acid by chain stripping, has been shown to be accelerated by the presence of clay. In this work we show that clay does affect the degradation pathway and that the presence of hydroxyl groups on the edges of the clay could be the cause of the accelerated initial step. The products of the second step of the degradation are changed in quantity and some new products are produced, showing that the clay also has an effect on this step of the degradation pathway. A scheme is suggested to account for the role of the clay in the degradation.
The parasite Toxoplasma gondii can cause congenital toxoplasmosis following primary infection in a pregnant woman. It is therefore important to distinguish between recent and past infection when both ...T. gondii-specific IgM and IgG are detected in a single serum in pregnant women. Toxoplasma gondii-specific IgG avidity testing is an essential tool to help to date the infection. However, interpretation of its results can be complex.
To review the benefits and limitations of T. gondii-specific avidity testing in pregnant women, to help practitioners to interpret the results and adapt the patient management.
PubMed search with the keywords avidity, toxoplasmosis and Toxoplasma gondii for articles published from 1989 to 2019.
Toxoplasma gondii-specific IgG avidity testing remains a key tool for dating a T. gondii infection in immunocompetent pregnant women. Several commercial assays are available and display comparable performances. A high avidity result obtained on a first-trimester serum sample is indicative of a past infection, which occurred before pregnancy. To date, a low avidity result must still be considered as non-informative to date the infection, although some authors suggest that very low avidity results are highly suggestive of recent infections depending on the assay. Interpretation of low or grey zone avidity results on a first-trimester serum sample, as well as any avidity result on a second-trimester or third-trimester serum sample, is more complex and requires recourse to expert toxoplasmosis laboratories.
Although used for about 30 years, T. gondii-specific avidity testing has scarcely evolved. The same difficulties in interpretation have persisted over the years. Some authors have proposed additional thresholds to exclude an infection of <9 months, or in contrast to confirm a recent infection. Such thresholds would be of great interest to adapt management of pregnant women and avoid unnecessary treatment; however, they need confirmation and further studies.
Following the EUROfusion PPPT-programme action for an advanced modeling approach of deuteron-induced reaction cross sections, as well as specific data evaluations in addition of the TENDL files, an ...assessment of the details and corresponding outcome for the latter option of TALYS for the breakup model has been carried out. The breakup enhancement obtained in the meantime within computer code TALYS, by using the evaluated nucleon-induced reaction data of TENDL-2019, is particularly concerned. Discussion of the corresponding results, for deuteron-induced reactions on
58
Ni,
96
Zr, and
231
Pa target nuclei up to 200 MeV incident energy, includes limitations still existing with reference to the direct-reaction account.
At CERN-ISOLDE, high-purity radioactive ion beams of 219Fr and 221RaF were investigated with α-decay spectroscopy at the CRIS and ASET experiments in the course of three different experimental ...campaigns. The half-life of 215At, α-decay daughter of 219Fr, is measured to be 36.3(3)9μs, and that of 221Ra was determined to be 26.2(1)6s, both of which are well in line with the trends in this region of the nuclear landscape but at odds with some of the reported literature.
At CERN-ISOLDE, high-purity radioactive ion beams of
Fr and
RaF were investigated with α-decay spectroscopy at the CRIS and ASET experiments in the course of three different experimental campaigns. ...The half-life of
At, α-decay daughter of
Fr, is measured to be 36.3(3)9μs, and that of
Ra was determined to be 26.2(1)6s, both of which are well in line with the trends in this region of the nuclear landscape but at odds with some of the reported literature.
Half-lives of the low-lying yrast states of 212Po have been measured using the delayed coincidence fast-timing method. We report on the first measurement of the 41+ half-life, as well as a new ...measurement of the 61+ half-life with improved accuracy compared to previous studies. The extracted lifetime of the 41+ and 61+ state have been determined to be 100(14) ps and 1.66(28) ns respectively. With these measurements, precise values are now available for the reduced transition strengths B(E2) of all ground state band levels in 212Po up to the first 8+ state, in particular B(E2; 41+→21+) = 9.4(13) W.u. and B(E2;61+→41+) = 8.7(15) W.u. Comparison of the new available data with an α-clustering model calculation provides evidence that the inclusion of the α-cluster degree of freedom significantly improves agreement with experimental data compared to earlier shell model calculations.
The N=52Ga83β decay was studied at ALTO. The radioactive 83Ga beam was produced through the ISOL photofission technique and collected on a movable tape for the measurement of γ-ray emission following ...β decay. While β-delayed neutron emission has been measured to be 56–85% of the decay path, in this experiment an unexpected high-energy 5–9 MeV γ-ray yield of 16(4)% was observed, coming from states several MeVs above the neutron separation threshold. This result is compared with cutting-edge QRPA calculations, which show that when neutrons deeply bound in the core of the nucleus decay into protons via a Gamow–Teller transition, they give rise to a dipolar oscillation of nuclear matter in the nucleus. This leads to large electromagnetic transition probabilities which can compete with neutron emission, thus affecting the β-decay path. This process is enhanced by an excess of neutrons on the nuclear surface and may thus be a common feature for very neutron-rich isotopes, challenging the present understanding of decay properties of exotic nuclei.
Objectives
Because of the strong consumer driver towards more natural or higher sustainability cosmetic products, silk fibroin was evaluated to help develop a formulation with natural and effective ...ingredients for personal care. In order to exploit the physical properties of silk fibroin, it was evaluated to maximize the surfactant properties of other commercial ingredients to lower surface tension and build up viscosity. A synergistic effect was seen between silk fibroin and capryl glucoside, a sugar surfactant which exhibited a natural and effective co‐surfactant system. This system demonstrated better surface tension properties than sodium laureth sulphate (SLES), cocamidopropyl betaine (CAPB), rhamnolipids and sophorolipids, which led to greater foamability and cleansing properties. This system proved to also be compatible with polysaccharide viscosity modifiers to enhance the viscosity of the system. The present study comprises a systematic exploration of natural formulation development of silk proteins and other natural ingredients, which result in high performance such as enhanced foam quality, foam stability and enhanced sebum removal. All of these properties are desirable and may utilized when formulating cleaners and shampoos.
Methods
A force tensiometer, Attension Sigma 701, was used to measure the surface tension of the silk protein and its various combinations with biosurfactants and biopolymers. To measure bulk rheology, a traditional mechanical rheometer TA DHR‐3 was utilized. Foaming tests and sebum removal assays were also carried out to evaluate the performance of the samples.
Results
Silk fibroin was evaluated to maximize the surfactant properties of other commercial systems to develop a formulation containing natural and effective ingredients for personal care. The surface activity of silk proteins was seen to be synergistically enhanced in the presence of sugar surfactants such as capryl glucoside, resulting in a surface tension at the air–water interface which is lower than either that of pure silk fibroin or pure capryl glucoside. This surface tension value is additionally lower than that obtained from currently utilized synthetic surfactants like sodium laureth sulphate (SLES) and cocamidopropyl betaine (CAPB). This reduction in surface tension demonstrated greater foamability and cleansing properties than that of the commercial systems. The very low surface tension values obtained through combinations of silk proteins and glucoside resulted in a natural and effective co‐surfactant system by forming high‐quality stable foams and enhancing sebum removal. The rheological performance of the silk proteins was impacted through microstructure modifications as a result of interactions with biopolymers like carrageenan. This shows that this system is compatible with polysaccharide viscosity modifiers. It was observed that both the flow curve and the absolute viscosity values were significantly impacted in the presence of carrageenan, with higher viscosity generation and significant non‐Newtonian/shear thinning behaviour evolution. These results indicate that the silk fibroin can be utilized to build a high‐performance natural product and significantly enhance the performance of other natural/sustainable cosmetic formulations through building synergistic interactions with other natural ingredients such as sugar surfactants and biopolymers. These properties exhibited by this system are all desirable for cleansers and shampoos within the cosmetic industry.
Conclusion
Silk fibroin in combination with capryl glucoside outperforms other commercial surfactants that are commonly used in the industry because of its surface‐active behaviour and synergy. This system is then enhanced further with polysaccharide rheological modifiers, carrageen and xanthan gum to help build up viscosity. The complex mixture of silk fibroin, sugar surfactant and biopolymer results in a formulation that is all natural, while still having high performance by achieving great foamability and enhanced sebum removal. The mixture can further be used to formulate a fully natural product such as a cleanser or shampoo while still having the same or greater effectiveness as synthetic surfactants and ingredients typically used in cosmetic formulations.
Abstrait
Objectifs
En raison de la forte incitation des consommateurs vers des produits cosmétiques plus naturels ou plus durables, la fibroïne de soie a été évaluée pour aider à développer une formulation avec des ingrédients naturels et efficaces pour les soins personnels. Afin d'exploiter les propriétés physiques de la fibroïne de soie, il a été évalué pour maximiser les propriétés tensioactives d'autres ingrédients commerciaux pour abaisser la tension superficielle et augmenter la viscosité. Un effet synergique a été observé entre la fibroïne de soie et le capryl glucoside, un tensioactif de sucre qui présentait un système de co‐tensioactif naturel et efficace. Ce système a démontré de meilleures propriétés de tension superficielle que le laureth sulfate de sodium (SLES), la cocamidopropyl bétaïne (CAPB), les rhamnolipides et les sophorolipides, ce qui a conduit à une plus grande moussabilité et des propriétés de nettoyage. Ce système s'est avéré également compatible avec les modificateurs de viscosité polysaccharidiques pour améliorer la viscosité du système. La présente étude comprend une exploration systématique du développement de formulation naturelle de protéines de soie et d'autres ingrédients naturels, qui se traduisent par des performances élevées telles qu'une qualité de mousse améliorée, une stabilité de la mousse et une élimination améliorée du sébum. Toutes ces propriétés sont souhaitables et peuvent être utilisées lors de la formulation de nettoyants et de shampooings.
Méthodes
Un tensiomètre de force, Attension Sigma 701, a été utilisé pour mesurer la tension superficielle de la protéine de soie et ses diverses combinaisons avec des biosurfactants et des biopolymères. Pour mesurer la rhéologie de masse, un rhéomètre mécanique traditionnel TA DHR‐3 a été utilisé. Tests de moussage et dosages d'élimination du sébum ont également été réalisés pour évaluer les performances des échantillons.
Résultats
La fibroïne de soie a été évaluée pour maximiser les propriétés tensioactives d'autres systèmes commerciaux afin de développer une formulation contenant des ingrédients naturels et efficaces pour les soins personnels. L'activité de surface des protéines de soie s'est avérée être renforcée de manière synergique en présence d'agents tensioactifs de sucre tels que le capryl glucoside, entraînant une tension de surface à l'interface air‐eau qui est inférieure à celle de la fibroïne de soie pure ou du capryl glucoside pur. Cette valeur de tension superficielle est en outre inférieure à celle obtenue à partir d'agents tensioactifs synthétiques actuellement utilisés comme le laureth sulfate de sodium (SLES) et la cocamidopropyl bétaïne (CAPB). Cette réduction de la tension superficielle a démontré une moussabilité et des propriétés de nettoyage supérieures à celles des systèmes commerciaux. Les très faibles valeurs de tension superficielle obtenues grâce à des combinaisons de protéines de soie et de glucoside ont abouti à un système de co‐tensioactif naturel et efficace en formant des mousses stables de haute qualité et en améliorant l'élimination du sébum. Les performances rhéologiques des protéines de soie ont été affectées par des modifications de microstructure à la suite d'interactions avec des biopolymères comme le carraghénane. Cela montre que ce système est compatible avec les modificateurs de viscosité polysaccharidiques. Il a été observé que la courbe d'écoulement et les valeurs de viscosité absolue étaient significativement affectées en présence de carraghénane, avec une génération de viscosité plus élevée et une évolution significative du comportement d'amincissement non newtonien / cisaillement. Ces résultats indiquent que la fibroïne de soie peut être utilisée pour construire un produit naturel haute performance et améliorer considérablement les performances d'autres formulations cosmétiques naturelles / durables en créant des interactions synergiques avec d'autres ingrédients naturels tels que les tensioactifs de sucre et les biopolymères. Ces propriétés présentées par ce système sont toutes souhaitables pour les nettoyants et les shampooings dans l'industrie cosmétique.
Conclusion
La fibroïne de soie en combinaison avec le capryl glucoside surpasse les autres tensioactifs du commerce couramment utilisés dans l'industrie en raison de son comportement tensioactif et de sa synergie. Ce système est ensuite amélioré avec des modificateurs rhéologiques polysaccharidiques, de la carraghénine et de la gomme xanthane pour aider à augmenter la viscosité. Le mélange complexe de fibroïne de soie, de tensioactif de sucre et de biopolymère donne une formulation entièrement naturelle, tout en conservant des performances élevées en obtenant une grande capacité de moussage et une élimination améliorée du sébum. Le mélange peut en outre être utilisé pour formuler un produit entièrement naturel tel qu'un nettoyant ou un shampooing tout en ayant toujours la même efficacité ou une plus grande efficacité que les tensioactifs synthétiques et les ingrédients généralement utilisés dans les formulations cosmétiques.
This study highlights the potential synergistic surface activity of silk fibroin and capryl glucoside to form a natural co‐surfactant system that exhibits enhanced foamability and cleansing.
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