10 research outputs found
Discerning natural and anthropogenic organic matter inputs to salt marsh sediments of Ria Formosa lagoon (South Portugal)
Sedimentary organic matter (OM) origin and molecular composition provide useful information to understand carbon cycling in coastal wetlands. Core sediments from threors' Contributionse transects along Ria Formosa lagoon intertidal zone were analysed using analytical pyrolysis (Py-GC/MS) to determine composition, distribution and origin of sedimentary OM. The distribution of alkyl compounds (alkanes, alkanoic acids and alkan-2-ones), polycyclic aromatic hydrocarbons (PAHs), lignin-derived methoxyphenols, linear alkylbenzenes (LABs), steranes and hopanes indicated OM inputs to the intertidal environment from natural-autochthonous and allochthonous-as well as anthropogenic. Several n-alkane geochemical indices used to assess the distribution of main OM sources (terrestrial and marine) in the sediments indicate that algal and aquatic macrophyte derived OM inputs dominated over terrigenous plant sources. The lignin-derived methoxyphenol assemblage, dominated by vinylguaiacol and vinylsyringol derivatives in all sediments, points to large OM contribution from higher plants. The spatial distributions of PAHs (polyaromatic hydrocarbons) showed that most pollution sources were mixed sources including both pyrogenic and petrogenic. Low carbon preference indexes (CPI > 1) for n-alkanes, the presence of UCM (unresolved complex mixture) and the distribution of hopanes (C-29-C-36) and steranes (C-27-C-29) suggested localized petroleum-derived hydrocarbon inputs to the core sediments. Series of LABs were found in most sediment samples also pointing to domestic sewage anthropogenic contributions to the sediment OM.EU Erasmus Mundus Joint Doctorate fellowship (FUECA, University of Cadiz, Spain)EUEuropean Commission [FP7-ENV-2011, 282845, FP7-534 ENV-2012, 308392]MINECO project INTERCARBON [CGL2016-78937-R]info:eu-repo/semantics/publishedVersio
Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications
Superparamagnetic iron oxide nanoparticles
can providemultiple benefits for biomedical applications
in aqueous environments such asmagnetic separation or
magnetic resonance imaging. To increase the colloidal
stability and allow subsequent reactions, the introduction
of hydrophilic functional groups onto the particles’
surface is essential. During this process, the original
coating is exchanged by preferably covalently bonded
ligands such as trialkoxysilanes. The duration of the
silane exchange reaction, which commonly takes more
than 24 h, is an important drawback for this approach. In
this paper, we present a novel method, which introduces
ultrasonication as an energy source to dramatically
accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove
the generic character, different functional groups were
introduced on the surface including polyethylene glycol
chains, carboxylic acid, amine, and thiol groups. Their
colloidal stability in various aqueous buffer solutions as
well as human plasma and serum was investigated to
allow implementation in biomedical and sensing
applications.status: publishe
Validity and reliability of total body volume and relative body fat mass from a 3-dimensional photonic body surface scanner
OBJECTIVE: Three-dimensional photonic body surface scanners (3DPS) feature a tool to estimate total body volume (BV) from 3D images of the human body, from which the relative body fat mass (%BF) can be calculated. However, information on validity and reliability of these measurements for application in epidemiological studies is limited. METHODS: Validity was assessed among 32 participants (men, 50%) aged 20-58 years. BV and %BF were assessed using a 3DPS (VitusSmart XXL) and air displacement plethysmography (ADP) with a BOD POD(R) device using equations by Siri and Brozek. Three scans were obtained per participant (standard, relaxed, exhaled scan). Validity was evaluated based on the agreement of 3DPS with ADP using Bland Altman plots, correlation analysis and Wilcoxon signed ranks test for paired samples. Reliability was investigated in a separate sample of 18 participants (men, 67%) aged 25-66 years using intraclass correlation coefficients (ICC) based on two repeated 3DPS measurements four weeks apart. RESULTS: Mean BV and %BF were higher using 3DPS compared to ADP, (3DPS-ADP BV difference 1.1 +/- 0.9 L, p<0.01; %BF difference 7.0 +/- 5.6, p<0.01), yet the disagreement was not associated with gender, age or body mass index (BMI). Reliability was excellent for 3DPS BV (ICC, 0.998) and good for 3DPS %BF (ICC, 0.982). Results were similar for the standard scan and the relaxed scan but somewhat weaker for the exhaled scan. CONCLUSIONS: Although BV and %BF are higher than ADP measurements, our data indicate good validity and reliability for an application of 3DPS in epidemiological studies
Thrombin-receptor antagonist vorapaxar in acute coronary syndromes
BACKGROUND
Vorapaxar is a new oral protease-activated–receptor 1 (PAR-1) antagonist that inhibits
thrombin-induced platelet activation.
METHODS
In this multinational, double-blind, randomized trial, we compared vorapaxar with
placebo in 12,944 patients who had acute coronary syndromes without ST-segment
elevation. The primary end point was a composite of death from cardiovascular causes,
myocardial infarction, stroke, recurrent ischemia with rehospitalization, or urgent
coronary revascularization.
RESULTS
Follow-up in the trial was terminated early after a safety review. After a median follow-up
of 502 days (interquartile range, 349 to 667), the primary end point occurred in 1031
of 6473 patients receiving vorapaxar versus 1102 of 6471 patients receiving placebo
(Kaplan–Meier 2-year rate, 18.5% vs. 19.9%; hazard ratio, 0.92; 95% confidence interval
[CI], 0.85 to 1.01; P = 0.07). A composite of death from cardiovascular causes,
myocardial infarction, or stroke occurred in 822 patients in the vorapaxar group
versus 910 in the placebo group (14.7% and 16.4%, respectively; hazard ratio, 0.89;
95% CI, 0.81 to 0.98; P = 0.02). Rates of moderate and severe bleeding were 7.2% in the
vorapaxar group and 5.2% in the placebo group (hazard ratio, 1.35; 95% CI, 1.16 to 1.58;
P<0.001). Intracranial hemorrhage rates were 1.1% and 0.2%, respectively (hazard
ratio, 3.39; 95% CI, 1.78 to 6.45; P<0.001). Rates of nonhemorrhagic adverse events
were similar in the two groups.
CONCLUSIONS
In patients with acute coronary syndromes, the addition of vorapaxar to standard
therapy did not significantly reduce the primary composite end point but significantly
increased the risk of major bleeding, including intracranial hemorrhage