865 research outputs found
Fractionation and identification of antioxidant peptides from an enzymatically hydrolysed Palmaria palmata protein isolate
peer-reviewedProteins derived from the macroalgal species Palmaria palmata have emerged as potential substrates for the generation of bioactive peptides. The aim of this study was to fractionate, identify and characterize antioxidant peptides from a P. palmata protein hydrolysate. The P. palmata protein hydrolysate generated with the food-grade proteolytic enzyme Corolase PP was sequentially fractionated using solid phase extraction and semi-preparative (SP) RP-HPLC. The most active SP-RP-HPLC peptide fraction (SP-RP-HPLC-30-F26) was analysed by ESI-MS/MS. Seventeen novel peptide sequences were identified in this fraction. Of the peptides selected for synthesis, Ser-Asp-Ile-Thr-Arg-Pro-Gly-Gly-Asn-Met, showed the highest oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) activity with values of 152.43 ± 2.73 and 21.23 ± 0.90 nmol TE/μmol peptide, respectively. The results presented herein indicate that P. palmata derived peptides may have potential applications as health enhancing ingredients and as food preservatives due to their antioxidant activity.ACCEPTEDpeer-reviewe
Penning ionization of doped helium nanodroplets following EUV excitation
Helium nanodroplets are widely used as a cold, weakly interacting matrix for
spectroscopy of embedded species. In this work we excite or ionize doped He
droplets using synchrotron radiation and study the effect onto the dopant atoms
depending on their location inside the droplets (rare gases) or outside at the
droplet surface (alkali metals). Using photoelectron-photoion coincidence
imaging spectroscopy at variable photon energies (20-25 eV), we compare the
rates of charge-transfer to Penning ionization of the dopants in the two cases.
The surprising finding is that alkali metals, in contrast to the rare gases,
are efficiently Penning ionized upon excitation of the (n=2)-bands of the host
droplets. This indicates rapid migration of the excitation to the droplet
surface, followed by relaxation, and eventually energy transfer to the alkali
dopants
Interaction Energies of Generalised Monopoles
Generalisations of the 't Hooft-Polyakov monopole which can exhibit repulsion
only, attraction only, and both attraction and repulsion, between like
monopoles, are studied numerically. The models supporting these solitons are
SO(3) gauged Higgs models featuring Skyrme-like terms.Comment: 46 pages, including 22 postscript figures, LaTex forma
The sources and correlates of exposure to vaccine-related (mis)information online
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Objectives: To assess the quantity and type of vaccine-related information Americans consume online and its relationship to social media use and attitudes toward vaccines. Methods: Analysis of individual-level web browsing data linked with survey responses from representative samples of Americans collected between October 2016 and February 2019. Results: We estimate that approximately 84% of Americans visit a vaccine-related webpage each year. Encounters with vaccine-skeptical content are less frequent; they make up only 7.5% of vaccine-related pageviews and are encountered by only 18.5% of people annually. However, these pages are more likely to be published by untrustworthy sources. Moreover, skeptical content exposure is more common among people with less favorable vaccine attitudes. Finally, usage of online intermediaries is frequently linked to vaccine-related information exposure. Google use is differentially associated with subsequent exposure to non-skeptical content, whereas exposure to vaccine-skeptical webpages is associated with usage of webmail and, to a lesser extent, Facebook. Conclusions: Online exposure to vaccine-skeptical content is relatively rare, but vigilance is required given the potential for exposure among vulnerable audiences.European Commissio
Ice XII in its second regime of metastability
We present neutron powder diffraction results which give unambiguous evidence
for the formation of the recently identified new crystalline ice phase[Lobban
et al.,Nature, 391, 268, (1998)], labeled ice XII, at completely different
conditions. Ice XII is produced here by compressing hexagonal ice I_h at T =
77, 100, 140 and 160 K up to 1.8 GPa. It can be maintained at ambient pressure
in the temperature range 1.5 < T < 135 K. High resolution diffraction is
carried out at T = 1.5 K and ambient pressure on ice XII and accurate
structural properties are obtained from Rietveld refinement. At T = 140 and 160
K additionally ice III/IX is formed. The increasing amount of ice III/IX with
increasing temperature gives an upper limit of T ~ 150 K for the successful
formation of ice XII with the presented procedure.Comment: 3 Pages of RevTeX, 3 tables, 3 figures (submitted to Physical Review
Letters
Protocol for a 1-year prospective, longitudinal cohort study of patients undergoing Roux-en-Y gastric bypass and sleeve gastrectomy: the BARI-LIFESTYLE observational study
INTRODUCTION: Roux-en-Y gastric bypass and sleeve gastrectomy are the two most common bariatric surgery performed in the UK that result in comparable weight loss and remission of obesity-associated comorbidities. However, there is a paucity of studies examining the impact of these procedures on body composition, physical activity levels, sedentary behaviour, physical function and strength, dietary intake, health-related quality of life and costs. METHODS AND ANALYSIS: The BARI-LIFESTYLE observational study is a 1-year prospective, longitudinal cohort study within a real-world routine clinical care setting aiming to recruit 100 patients with severe obesity undergoing either primary Roux-en-Y gastric bypass or sleeve gastrectomy from two bariatric centres in London, UK. Participants will be followed up four times during the study period; presurgery baseline (T0) and at 3 (T1), 6 (T2) and 12 months (T3) postsurgery. In addition to the standard follow-up investigations, assessments including dual-energy X-ray absorptiometry scan, bioelectric impedance analysis, 6 min walk test, sit-to-stand test and handgrip test will be undertaken together with completion of questionnaires. Physical activity levels and sedentary behaviour will be assessed using accelerometer, and dietary intake will be recorded using a 3-day food diary. Outcome measures will include body weight, body fat mass, lean muscle mass, bone mineral density, physical activity levels, sedentary behaviour, physical function and strength, dietary intake, health-related quality of life, remission of comorbidities, healthcare resource utilisation and costs. ETHICS AND DISSEMINATION: This study has been reviewed and given a favourable ethical opinion by London-Dulwich Research Ethics Committee (17/LO/0950). The results will be presented to stakeholder groups locally, nationally and internationally and published in peer-reviewed medical journals. The lay-person summary of the findings will be published on the Centre for Obesity Research, University College London website (http://www.ucl.ac.uk/obesity)
Interplay of post collision interaction and photoelectron recapture in the near threshold inner shell ionization of rare gases
The Ar 2p?11/2 n?, Kr 3d1/2?1 n? and Xe 4d?11/2 n? resonances have been photoexcited and the angular distributions of the low energy electrons ejected in the autoionistaion to the lower spin orbit component of the respective ions have been measured. The observed lineshapes can be described by a combination of the post-collision interaction effects and the electron recapture probability in the very near threshold region
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