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排序方式: 共有409条查询结果,搜索用时 15 毫秒
21.
Helena Ribeiro Joana Marto Sara Raposo Maria Agapito Vera Isaac Bruna G. Chiari Pedro F. Lisboa Alexandre Paiva Susana Barreiros Pedro Simões 《European Journal of Lipid Science and Technology》2013,115(3):330-336
Spent coffee grounds (SCG), which are the residue obtained from the treatment of coffee with hot water or steam, can be used for industrial applications, due to the high content in lipids. The cosmetic products might be a suitable application for these types of residues because the barrier properties of the stratum corneum (SC) are largely dependent on the intactness of the lipid lamellae that surrounds the corneocytes. The purpose of this work was to assess the feasibility of using the lipid fraction of SCG extracted with supercritical carbon dioxide in the development of new cosmetic formulations with improved skin lipids (sebum) and hydration. The use of spent coffee lipid extract in cosmetic industry seems to be a suitable approach to recycle the wastes from coffee industry. Emulsion containing 10% of the lipid fraction of SCG (SpentCofOil cream) presented promising characteristics in the improvement of sebum skin levels with a good acceptance by consumers when compared to an emulsion containing 10% w/w of green coffee oil (GreenCofOil cream) and a placebo without coffee oil (NoCofOil cream). Practical applications: In this work, the authors develop and characterize a cream containing 10% of the lipid fraction of SCG extracted with supercritical carbon dioxide with improved skin lipids (sebum) and hydration. 相似文献
22.
A basic mathematical model, mainly focused on economic assessment is directly applied to a counter-current, stage-wise, solvent-selective extraction system. A standard extraction model, based on the modeling of a mixer-settler process, is used as point of departure. This system is used to extract a dissolved compound in a process stream. Thereafter sensible operating and economic parameters are integrated into it. An adequate handling of these parameters allows a practical preliminary optimization process modeling. The economic assessment model can be applied from one to ri stages in any industrial stage-wise process unit. An optimum number of stages are determined based on solvent extraction and economic assessment. 相似文献
23.
Julia Peas-Martínez María N. Barrachina Ernesto Jos Cuenca-Zamora Gins Luengo-Gil Susana Beln Bravo Eva Caparrs-Prez Raúl Teruel-Montoya Jos Eliseo-Blanco Vicente Vicente ngel García Irene Martínez-Martínez Francisca Ferrer-Marín 《International journal of molecular sciences》2021,22(4)
Exosomes are extracellular vesicles that contain nucleic acids, lipids and metabolites, and play a critical role in health and disease as mediators of intercellular communication. The majority of extracellular vesicles in the blood are platelet-derived. Compared to adults, neonatal platelets are hyporeactive and show impaired granule release, associated with defects in Soluble N-ethylmaleimide-sensitive fusion Attachment protein REceptor (SNARE) proteins. Since these proteins participate in biogenesis of exosomes, we investigated the potential differences between newborn and adult plasma-derived exosomes. Plasma-derived exosomes were isolated by ultracentrifugation of umbilical cord blood from full-term neonates or peripheral blood from adults. Exosome characterization included size determination by transmission electron microscopy and quantitative proteomic analysis. Plasma-derived exosomes from neonates were significantly smaller and contained 65% less protein than those from adults. Remarkably, 131 proteins were found to be differentially expressed, 83 overexpressed and 48 underexpressed in neonatal (vs. adult) exosomes. Whereas the upregulated proteins in plasma exosomes from neonates are associated with platelet activation, coagulation and granule secretion, most of the underexpressed proteins are immunoglobulins. This is the first study showing that exosome size and content change with age. Our findings may contribute to elucidating the potential “developmental hemostatic mismatch risk” associated with transfusions containing plasma exosomes from adults. 相似文献
24.
A.?Moreno C.?Bengoechea J.?Bravo J.?L.?BernaEmail author 《Journal of surfactants and detergents》2003,6(2):137-142
Modern industrial sulfonation of linear alkylbenzene (LAB) in falling film reactors produces p-alkylbenzene sulfonic acid (HLAS), which is usually neutralized with caustic soda (NaOH) and used in detergent formulations.
During the sulfonation process, other products such as anhydrides and sulfones are also formed. Four reactions are proposed
to occur during aging and hydrolysis. As a consequences, approximately 25% of sulfones and 75% of unreacted LAB are removed
during aging and are transformed into additional active matter. Anhydrides are completely eliminated during hydrolysis. On
the other hand, sulfones formed during the process are difficult to remove once formed. The goal of this work was to optimize
the various operating conditions of the sulfonation process and to understand the various secondary reactions that occur therein
so as to obtain a maximal active ingredient concentration in the final sulfonated product and a minimum of unsulfonated matter.
Formation of sulfones can be minimized by using an SO3/LAB molar ratio slightly lower than the theoretical optimum. 相似文献
25.
26.
Leopoldo Bertossi Loreto Bravo Enrico Franconi Andrei Lopatenko 《Information Systems》2008,33(4-5):407-434
Consistent query answering is the problem of characterizing and computing the semantically correct answers to queries from a database that may not satisfy certain integrity constraints. Consistent answers are characterized as those answers that are invariant under all minimally repaired versions of the original database. We study the problem of repairing databases with respect to denial constraints by fixing integer numerical values taken by attributes. We introduce a quantitative definition of database repair, and investigate the complexity of several decision and optimization problems. Among them, Database Repair Problem (DRP): deciding the existence of repairs within a given distance to the original instance, and CQA: deciding consistency of answers to simple and aggregate conjunctive queries under different semantics. We provide sharp complexity bounds, identifying relevant tractable and intractable cases. We also develop approximation algorithms for the latter. Among other results, we establish: (a) The -hardness of CQA. (b) That DRP is MAXSNP-hard, but has a good approximation. (c) The intractability of CQA for aggregate queries for one database atom denials (plus built-ins), and also that it has a good approximation. 相似文献
27.
Two populations are subdivided into two categories of individuals (hawks and lows). Individuals fight to have access to a resource which is necessary for their survival. Conflicts occur between individuals belonging to the same population and to different populations. We investigate the long term effects of the conflicts on the stability of the community. The model is a set of ODE's with four variables corresponding to hawk and dove individuals of the two populations. Two time scales are considered. A fast time scale is used to describe frequent encounters and fightings between individuals trying to monopolize the resource. A slow time scale is used for the demography and the long term effects of encounters. We use aggregation methods in order to reduce this model into a system of two ODE's only for the total densities of the two populations which is found to be a classical Lotka-Volterra competition model. We study different cases of proportions of hawks and doves in both populations on the global coexistence and the mutual exclusion of the two populations. Pure dove tactics in both populations are unstable. In cases of mixed hawk and dove in both populations, there is coexistence. Pure dove or mixed hawk-dove tactics in one population can coexist with pure hawks in the other one when the costs of fightings between hawks are large enough. 相似文献
28.
V. M. Salinas‐Bravo J. Porcayo‐Caldern T. Romero‐Castaon G. Domínguez‐Patio J. G. Gonzalez‐Rodriguez 《工业材料与腐蚀》2005,56(7):481-484
Electrochemical potentiodynamic polarization curves and immersion tests for 300 h at 700°C in a furnace have been used to evaluate the corrosion resistance of Fe‐Si metallic coatings added with up to 50 wt.% of NiCrAIY. The corrosive environment was fuel oil ashes from a steam generator. The composition of fuel oil ashes includes high content of vanadium, sodium and sulfur. The results obtained show that only the addition of 20 wt.% NiCrAlY to the Fe‐Si coating improves its corrosion resistance. The behavior of all tested coatings is explained by the results obtained from the analysis of every coating using electron microscopy and energy dispersive X‐ray analysis. 相似文献
29.
Prevalence of Lactobacillus plantarum and Oenococcus oeni during spontaneous malolactic fermentation in Patagonian red wines revealed by polymerase chain reaction‐denaturing gradient gel electrophoresis with two targeted genes 下载免费PDF全文
30.
Èlia Navarro-Masip Francesca Manocchio Marina Colom-Pellicer Xavier Escoté Lisard Iglesias-Carres Enrique Calvo Francisca I Bravo Begoña Muguerza Yves Desjardins Gerard Aragonès 《Molecular nutrition & food research》2023,67(17):2300074