1,868 research outputs found
Emulsion formation and stabilization by biomolecules: the leading role of cellulose
Emulsion stabilization by native cellulose has been mainly hampered because of its insolubility in water. Chemical modification is normally needed to obtain water-soluble cellulose derivatives. These modified celluloses have been widely used for a range of applications by the food, cosmetic, pharmaceutic, paint and construction industries. In most cases, the modified celluloses are used as rheology modifiers (thickeners) or as emulsifying agents. In the last decade, the structural features of cellulose have been revisited, with particular focus on its structural anisotropy (amphiphilicity) and the molecular interactions leading to its resistance to dissolution. The amphiphilic behavior of native cellulose is evidenced by its capacity to adsorb at the interface between oil and aqueous solvent solutions, thus being capable of stabilizing emulsions. In this overview, the fundamentals of emulsion formation and stabilization by biomolecules are briefly revisited before different aspects around the emerging role of cellulose as emulsion stabilizer are addressed in detail. Particular focus is given to systems stabilized by native cellulose, either molecularly-dissolved or not (Pickering-like effect).Financially support by the Portuguese Foundation for Science and Technology, FCT, via the projects PTDC/AGR-TEC/4814/2014, PTDC/ASP-SIL/30619/2017 and researcher grant IF/01005/2014. RISE Research Institutes of Sweden AB and PERFORM, a competence platform in Formulation Science at RISE, are acknowledged for additional financing. This research has been supported by
Treesearch.se.info:eu-repo/semantics/publishedVersio
Novel self-assembled morphologies from isotropic interactions
We present results from particle simulations with isotropic medium range
interactions in two dimensions. At low temperature novel types of aggregated
structures appear. We show that these structures can be explained by
spontaneous symmetry breaking in analytic solutions to an adaptation of the
spherical spin model. We predict the critical particle number where the
symmetry breaking occurs and show that the resulting phase diagram agrees well
with results from particle simulations.Comment: 4 pages, 4 figure
Observation of a Free-Shercliff-Layer Instability in Cylindrical Geometry
We report on observations of a free-Shercliff-layer instability in a
Taylor-Couette experiment using a liquid metal over a wide range of Reynolds
numbers, . The free Shercliff layer is formed by imposing a
sufficiently strong axial magnetic field across a pair of differentially
rotating axial endcap rings. This layer is destabilized by a hydrodynamic
Kelvin-Helmholtz-type instability, characterized by velocity fluctuations in
the plane. The instability appears with an Elsasser number above
unity, and saturates with an azimuthal mode number which increases with the
Elsasser number. Measurements of the structure agree well with 2D global linear
mode analyses and 3D global nonlinear simulations. These observations have
implications for a range of rotating MHD systems in which similar shear layers
may be produced.Comment: 5 pages, 4 figure
Role of cephalosporins in the era of Clostridium difficile infection
The incidence of Clostridium difficile infection (CDI) in Europe has increased markedly since 2000. Previous meta-analyses have suggested a strong association between cephalosporin use and CDI, and many national programmes on CDI control have focused on reducing cephalosporin usage. Despite reductions in cephalosporin use, however, rates of CDI have continued to rise. This review examines the potential association of CDI with cephalosporins, and considers other factors that influence CDI risk. EUCLID (the EUropean, multicentre, prospective biannual point prevalence study of CLostridium difficile Infection in hospitalized patients with Diarrhoea) reported an increase in the annual incidence of CDI from 6.6 to 7.3 cases per 10 000 patient bed-days from 2011–12 to 2012–13, respectively. While CDI incidence and cephalosporin usage varied widely across countries studied, there was no clear association between overall cephalosporin prescribing (or the use of any particular cephalosporin) and CDI incidence. Moreover, variations in the pharmacokinetic and pharmacodynamic properties of cephalosporins of the same generation make categorization by generation insufficient for predicting impact on gut microbiota. A multitude of additional factors can affect the risk of CDI. Antibiotic choice is an important consideration; however, CDI risk is associated with a range of antibiotic classes. Prescription of multiple antibiotics and a long duration of treatment are key risk factors for CDI, and risk also differs across patient populations. We propose that all of these are factors that should be taken into account when selecting an antibiotic, rather than focusing on the exclusion of individual drug classes
Turbulence and jet-driven zonal flows: Secondary circulation in rotating fluids due to asymmetric forcing
We report on experiments and modeling on a rotating confined liquid that is forced by circumferential jets coaxial with the rotation axis, wherein system-scale secondary flows are observed to emerge. The jets are evenly divided in number between inlets and outlets and have zero net mass transport. For low forcing strengths the sign of this flow depends on the sign of a sloped end cap, which simulates a planetary β plane. For increased forcing strengths the secondary flow direction is insensitive to the slope sign, and instead appears to be dominated by an asymmetry in the forcing mechanism, namely, the difference in radial divergence between the inlet and outlet jet profiles. This asymmetry yields a net radial velocity that is affected by the Coriolis force, inducing secondary zonal flow
Economic Impacts of Climate Change Mitigation in the State of Montana
In 2017, several sources of the state of Montana’s economy are susceptible to climate change impacts; those industries include tourism, agriculture, wildlife management, and outdoor recreation. In recent years, political figures, national governments, and grassroots organizations have called for extreme methods of climate change mitigation for the entire global community. In response, communities, countries, and individuals have responded and changed their habits and policies to begin mitigating climate change.
During this research, I analyzed peer reviewed articles, government documents, and interviews from Montana economy experts. From those results, I was able to discern the approximate amount of money associated with the Montana industries that are at risk from climate change. This dollar amount was compared to the estimated profit from industries associated with fossil fuels, or those industries that would succeed if no climate change mitigation was addressed.
In addition, my research included using climate model research to establish how the global impact of greenhouse gases would impact at-risk Montana industries. After synthesizing the results from the climate models with the comparative dollar amounts of Montana industries, this research concludes Montana mitigation would negatively impact the Montana economy.
By means of secondary research and a synthesizing of the conclusions of credible economists, local energy experts, technology scientists, and climate scientists, this paper hypothesizes that extreme climate change mitigation methods in Montana would have no direct impact impact on the quality of Montana’s environment, and would actually decrease the total economic profit of the state of Montana and its collective inhabitants
Preface
Reproductive tract bleeding in women is a naturally occurring event during menstruation and childbirth. In women with menorrhagia, however, congenital bleeding disorders historically have been underdiagnosed. This consensus is intended to allow physicians to better recognize bleeding disorders as a cause of menorrhagia and consequently offer effective disease-specific therapies. © 2009 Mosby, Inc. All rights reserved
- …
