Ação de dentifrício na redução da sensibilidade associada ao clareamento dental caseiro: estudo clínico piloto / Toothpaste action in reducing sensitivity associated with home tooth whitening: pilot clinical study

Objetivo: Avaliar, clinicamente, a ação do dentifrício REGENERATE TM Emanel Science na redução da dor e variação de cor causadas pela técnica de clareamento dental caseiro por meio de um estudo clínico duplo cego controlado. Materiais e Métodos: foram selecionados 24 voluntários para serem submetidos ao clareamento dental caseiro em 4 sessões clínicas com intervalo de uma semana, usando gel clareador (peróxido de carbamida - 16%). Na manhã seguinte de cada sessão de clareamento, os voluntários usaram uma moldeira personalizada por 4 horas contendo um dos dentifrícios em relação aos grupos experimentais: (1) Sucralose (S) (Controle); (2) Fosfato de Sódio (FS) e Silicato de Cálcio (SC) - Tecnologia NR-5 (Tratamento). A dor foi avaliada antes do uso da moldeira com dentifrício (S1, S3, S5 e S7) e após (S2, S4, S6 e S8) por 4 semanas utilizando a escala numérica analógica com escores de 0 a 10. Para variação de cor (ΔE), foi utilizado um espectrofotômetro (Easyshade). Resultados: o grupo de tratamento (Tecnologia NR-5) apresentou redução da dor em relação ao grupo controle (p 0,05). Houve uma redução da dor após o uso do dentifrício na moldeira personalizada por 4 horas (S2, S4, S6 e S8) e não houve diferença de ΔE entre os grupos experimentais após o tratamento clareador (p = 0,918). Conclusão: o uso de dentifrício dessensibilizante com FS e SC (Technology NR-5) em moldeira plástica personalizada se mostrou uma opção de tratamento viável e eficiente para redução da dor causada pelo clareamento dental caseiro e o uso de dentifrício dessensibilizante não influenciou a eficácia do tratamento clareador, em relação à alteração de cor

Quantum cascade laser based hybrid dual comb spectrometer

Four-wave-mixing-based quantum cascade laser frequency combs (QCL-FC) are a powerful photonic tool, driving a recent revolution in major molecular fingerprint regions, i.e. mid- and far-infrared domains. Their compact and frequency-agile design, together with their high optical power and spectral purity, promise to deliver an all-in-one source for the most challenging spectroscopic applications. Here, we demonstrate a metrological-grade hybrid dual comb spectrometer, combining the advantages of a THz QCL-FC with the accuracy and absolute frequency referencing provided by a free-standing, optically-rectified THz frequency comb. A proof-of-principle application to methanol molecular transitions is presented. The multi-heterodyne molecular spectra retrieved provide state-of-the-art results in line-center determination, achieving the same precision as currently available molecular databases. The devised setup provides a solid platform for a new generation of THz spectrometers, paving the way to more refined and sophisticated systems exploiting full phase control of QCL-FCs, or Doppler-free spectroscopic schemes

A Physiologically Structured Equation to Consider Quota Heterogeneity in the Droop Model

The Droop model allows to represent microalgae growth limited by a nutrient, using a cell quota (also referred to as variable-yield) approach. Single-cell measurements have revealed quota heterogeneity in phytoplankton collected from field studies. Such heterogeneity can be due, among other factors, to spatial structure (e.g. in biogeochemical cycles in the ocean, or for photobioreactors connected in series). Nonetheless, quota heterogeneity is generally omitted in modelling studies, using an average quota approach, or included in size-structured or individual-based models. Here, we propose a distributed Droop equation to tackle this problem, considering subpopulation growth -in line with Droop macroscopic view- rather than cell division dynamics. We provide analytical solutions for two case studies. First, we consider a constant substrate concentration without biomass input, which leads to a monomorphic population. The second case, considering a biomass input without substrate, leads to quota heterogeneity. Simulations are then carried out for the two case studies (showing good agreements with the analytical solutions) and for a more general case. Finally, we show that the error induced by the average quota approach increases considerably with microalgae plasticity (i.e. the maximal over minimal quota ratio), which points out the benefit of considering quota heterogeneity in these cases

Manufacture of "fresh/wet" aquaculture feeds based on by-catches, fish by-products and algae

This work focuses on available bio resources transformation such as by-catches or fish by-products and marine plants (seaweed and microalgae) as ren circuit . The objective is to make this production as autonomous and sustainable as possible and fitted to the idea of circular economy. Thanks to previous projects, it seems that by-catches could be a plentiful source of proteins for fish. The challenge associated with this type of aquaculture formulations relies on the ability to incorporate abundant resources readily available and the significant reduction of certain energy‐consuming steps (such as drying) in order to minimize the environmental impact of a fish feed production. The adequacy of this strategy (fresh raw material and wet feed) with a specification of a nutritional efficient fish feed is the first goal of this project. Lot of studies indicate the potential benefits of a wet diet for fish (better feed conversion ratio, better palatability, increased survival). Otherwise, several studies suggested that seaweed and microalgae could be incorporated to fish diet with potential benefits such as antioxidant properties and promotion of immune responses. Regarding the process, an extrusion technology has been selected. It allows the assembly and functionalization of various ingredients and the manufacture of feeds with specific buoyancy, good stability in water, various shapes and sizes. Highly digestible feed for fish culture, can be produced by extrusion from various raw materials. The central idea of this work is to exploit the cold gelling potential of the fresh fishes by a shear mixing phase obtained by the rotation of the screws of the extruder followed by a baking step. The study of parameters allowing extrusion process control, the availability and possible assembly of the different raw materials according to nutritional requirements of targeted specie, the physical behavior of the feed (water stability, buoyancy) and its bioavailability (palatability, digestibility) as well as feed preservation and safety will be fully explored and exploited. Economic and environmental analysis is also one of the pillar of this project. Indeed, the impact, both economically and environmentally to produce "fresh/wet" aquaculture feed made by transforming through extrusion unwanted catches and plants with a specification of an efficient aquaculture feed constitute the challenge to be met Early trials indicate that textured fresh and wet feed can be made from fish muscles associated with algae by extrusion. Gelling of the fish is sufficient to obtain a feed of good texture.Cette étude s'intéresse à la transformation de bio ressources, telles que les captures accessoires, les sous-produits de poisson et les végétaux marins (algues et microalgues) utilisées comme matière première pour la fabrication d'aliments pour poissons en circuit court. L'objectif est de rendre cette production aussi autonome et durable que possible et adaptée à l'idée d'économie circulaire. Grâce à de précédents projets, il semble que les captures accessoires pourraient constituer une source abondante de protéines pour les poissons. Le défi associé à ce type de formulations aquacoles repose sur la capacité à incorporer ces ressources abondantes et la réduction significative de certaines étapes énergivores (telles que le séchage) afin de minimiser l'impact environnemental de la production d'aliments aquacole. L’adéquation de cette stratégie (matière première fraîche et aliment humide) avec une spécification nutritionnelle optimale est le premier objectif de ce projet. De nombreuses études indiquent les avantages potentiels d'un régime alimentaire humide pour les poissons (meilleur indice de conversion, meilleure appétence, augmentation de la survie). Par ailleurs, plusieurs études ont suggéré que les algues et les microalgues pourraient être incorporées dans l'alimentation des poissons avec des avantages potentiels intéressants (propriétés antioxydantes, promotion de réponses immunitaires). En ce qui concerne le procédé de transformation, une technologie d'extrusion a été choisie. Elle permet l'assemblage et la fonctionnalisation des divers ingrédients et la fabrication d'aliments présentant une flottabilité ciblée, une bonne stabilité dans l'eau, différentes formes et tailles. Des aliments hautement digestibles pour la nutrition aquacole peuvent être obtenus par extrusion à partir de différentes matières premières. L'idée centrale de ce travail est d'exploiter le potentiel de gélification à froid du poisson frais via le cisaillement obtenu par la rotation des vis de l'extrudeuse suivie d'une étape de cuisson. L'étude des paramètres permettant le contrôle du processus d'extrusion, la disponibilité et l'assemblage éventuel des différentes matières premières en fonction des besoins nutritionnels de l'espèce ciblée, du comportement physique de l'aliment (stabilité de l'eau, flottabilité) et de sa biodisponibilité ainsi que la conservation et la sécurité des aliments seront pleinement explorées et exploitées. L'analyse économique et environnementale est également l'un des piliers de ce projet. En effet, le défi à relever réside dans l’impact, à la fois économique et environnemental, de la production d’aliments aquacoles «frais / humides», transformés par extrusion de captures non désirées et de végétaux marins. Les premiers essais indiquent que des aliments texturés, frais et humides, peuvent être obtenus à partir des muscles des poissons associés aux algues par extrusion. La gélification du poisson est suffisante pour obtenir un aliment de bonne texture

Comparative Value of a Sorting Procedure and Quantitative Descriptive Analysis to Investigate the Influence of Processing Parameters: Case Study of Hydrolysate Production From Salmon By-Products

Many papers have recently discussed the value of a free sorting method as a rapid and simple alternative to quantitative descriptive analysis, considered the reference tool for food sensorial characterization. The aim of the present paper is to evaluate whether this method of free sorting can also be used to investigate the influence of processing parameters. An experimental design was applied to production conditions of enzymatic hydrolysates from salmon by-products. The effect of four processing parameters (time and temperature of hydrolysis, sugar and antioxidant addition) on the odor of the hydrolysates was studied using a sorting task with 45 untrained panelists and a quantitative descriptive analysis carried out with 11 trained panelists. This study on 21 enzymatic hydrolysates confirms the similarity of the two sensory maps and shows the value of free sorting in the sensory characteristic description step, especially to avoid missing some descriptors. It also highlights in this example that a holistic approach as sorting can reveal more easily than profiling the significant effects of process parameters on sensory characteristics and the relationships between sensory dimensions and instrumental measurements of volatile compounds

Reactive and/or enzymatic extrusion process for phycocolloids extraction: application to sea products

In this paper we present the reactive extrusion process to extract the phycocolloids from the sea products. By comparing with other techniques, this process has a several advantages like the economic return, the flexibility, the production of various products with different characteristics and time gains. There are two types of extruder: single-screw and double-screw, each one has its specific properties. The solid products are introduced by means of the hopper that is equipped with a dosage pump for the regulation of the flow. Liquid products are, generally, injected in the not filled zones, through an external pump. The products undergo thermo mechanical modifications and then the shaping of the final products was done in the die. The reactive extrusion is applied in several fields: agri-food where there are three main types of operating conditions (simple extrusion, extrusion-cooking, reactive extrusion), in the plastic industry for the recycling of household plastic waste and also to create mixtures between different polymers, as well in the field of chemistry and pharmaceutics. The reactive extrusion is used also to add value to the sea products like to extract phycocolloids especially the alginate from the seaweeds, also the chitin from crustacean by-product. A further interesting application of the reactive extrusion process is the energy production. Recent research is aimed to the valorization of fish by-products for the extraction of lipids for biofuel purpose.Dans cet article, nous présentons le procédé d'extrusion réactive pour extraire les phycocolloïdes des produits de la mer. En le comparant avec d'autres techniques, ce procédé présente plusieurs avantages comme le rendement économique, la flexibilité, la production de différents produits avec des caractéristiques différentes et des gains de temps. IL existe deux types d’extrudeuses : monovis et bivis, chacune ayant ses propriétés spécifiques. Les produits solides sont introduits par la trémie équipée d'une pompe doseuse pour la régulation du débit. Les produits liquides sont généralement injectés dans les zones non remplies, par une pompe externe. Les produits subissent des modifications thermo-mécaniques et ensuite la mise en forme des produits finis est réalisée par la filière. L'extrusion réactive est appliquée dans plusieurs domaines : l'agro-alimentaire où il existe trois utilisations principales (extrusion simple, cuisson-extrusion, extrusion réactive), dans l'industrie plastique pour le recyclage des déchets plastiques ménagers et aussi pour créer des mélanges entre de différents polymères, ainsi que dans le domaine de la chimie et la pharmacie. L'extrusion réactive est également utilisée pour la valorisation des produits de la mer comme l’extraction des phycocolloïdes, en particulier l'alginate à partir des algues marines, ainsi que la chitine des coproduits de crustacés. Une autre application intéressante du procédé d'extrusion réactive est la production d'énergie. Des recherches récentes visent à valoriser les coproduits de la pêche pour la production du biocarcurant