500 research outputs found
Challenges in Quantifying 8-OHdG and 8-Isoprostane in Exhaled Breath Condensate
Exhaled breath condensate (EBC) has attracted substantial interest in the last few years, enabling the assessment of airway inflammation with a non-invasive method. Concentrations of 8-Hydroxydesoxyguanosine (8-OHdG) and 8-isoprostane in EBC have been suggested as candidate biomarkers for lung diseases associated with inflammation and oxidative stress. EBC is a diluted biological matrix and consequently, requires highly sensitive chemical analytic methods (picomolar range) for biomarker quantification. We developed a new liquid chromatography coupled to tandem mass spectrometry method to quantify 8-OHdG and 8-isoprostane in EBC simultaneously. We applied this novel biomarker method in EBC obtained from 10 healthy subjects, 7 asthmatic subjects, and 9 subjects with chronic obstructive pulmonary disease. Both biomarkers were below the limit of detection (LOD) despite the good sensitivity of the chemical analytical method (LOD = 0.5 pg/mL for 8-OHdG; 1 pg/mL for 8-isoprostane). This lack of detection might result from factors affecting EBC collections. These findings are in line with methodological concerns already raised regarding the reliability of EBC collection for quantification of 8-OHdG and 8-isoprostane. Precaution is therefore needed when comparing literature results without considering methodological issues relative to EBC collection and analysis. Loss of analyte during EBC collection procedures still needs to be resolved before using these oxidative stress biomarkers in EBC
P1‐245: Mapping local structural hippocampal changes in Alzheimer's disease and normal aging on MR imaging at 3T
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Alfvén waves in the near-PSBL lobe: Cluster observations
Electromagnetic low-frequency waves in the magnetotail lobe close to the PSBL (Plasma Sheet Boundary Layer) are studied using the Cluster spacecraft. The lobe waves show Alfvénic properties and transport their wave energy (Poynting flux) on average toward the Earth along magnetic field lines. Most of the wave events are rich with oxygen (O+) ion plasma. The rich O+ plasma can serve to enhance the magnetic field fluctuations, resulting in a greater likelihood of observation, but it does not appear to be necessary for the generation of the waves. Taking into account the fact that all events are associated with auroral electrojet enhancements, the source of the lobe waves might be a substorm-associated instability, i.e. some instability near the reconnection site, or an ion beam-related instability in the PSBL
Towards Reference Values for Malondialdehyde on Exhaled Breath Condensate: A Systematic Literature Review and Meta-Analysis.
Many pathological conditions and certain airway exposures are associated with oxidative stress (OS). Malondialdehyde (MDA) is an end-product of the oxidation of lipids in our cells and is present in all biological matrices including exhaled breath condensate (EBC). To use MDA as a biomarker of OS in EBC, a reference interval should be defined. Thus, we sought to summarize reference values reported in healthy adult populations by performing a systematic review and meta-analysis using a standardized protocol registered in PROSPERO (CRD42020146623). Articles were retrieved from four major databases and 25 studies with 28 subgroups were included. Defining the distribution of MDA measured in reference populations with a detection combined with a separation technique still represents a challenge due to the low number of studies available, different analytical methods used, and questionable methodological qualities of many studies. The most salient methodological drawbacks have been in data collection and reporting of methods and study results by the researchers. The lack of compliance with the recommendations of the European Respiratory Society and American Thoracic Society was the major limitation in the current research involving EBC. Consequently, we were unable to establish a reference interval for MDA in EBC
An Epidemiological and biomolecular survey of cystic echinococcosis in cattle in Sardinia
Although Cystic Echinococcosis (CE) is still a
health, economic and social problem of great importance
in Sardinia today, not all aspects of it have
been studied, and in particular its epidemiology in
cattle. This note updates the epidemiological data
on Bovine CE in Sardinia, and with the help of
advances made in biomolecular taxonomy identifies
the strains of Echinococcus granulosus in cattle
Nephrops norvegicus in the Adriatic Sea: Connectivity modeling essential fish habitats and management area network
AbstractKnowledge of connectivity among subpopulations is fundamental in the identification of the appropriate geographical scales for stock status evaluation and management, the identification of areas with greater retention rates, and space‐based fisheries management. Here, an integration of hydrodynamic, biological, and habitat models results is used to assess connectivity and support the definition of essential fish habitats (EFH) in the Adriatic Sea, with reference to Nephrops norvegicus, an important benthic commercial resource, the recruitment of which is strongly related to larval dispersal from spawning to recruitment areas. We explored oceanographic and biological connectivity in the Adriatic Sea under a wide and representative variety of oceanographic conditions (winters 2006–2012) by tracking 3D trajectories of larvae released from different areas. We used a Lagrangian model that features a specific larval behavior module with explicit dependence on environmental parameters (i.e., temperature and sediment type) and that is driven by high‐resolution hydrodynamic and meteorological data. The results were used to partition the area in which Nephrops was observed into 20 homogenous management subareas; to assess the connection between spawning, recruitment, and harvesting grounds; and to identify potential subpopulation boundaries as well as the connectivity among the potential subpopulations. The results suggest the presence of at least three distinct subpopulations, which need to be independently managed and conserved, and confirms that the Jabuka‐Pomo pit is the most important spawning area, but alone it cannot sustain Nephrops populations throughout the Adriatic Sea. The results also show the importance to move from particle‐tracking to approaches based on integrated models
In search of phylogenetic congruence between molecular and morphological data in bryozoans with extreme adult skeletal heteromorphy
peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=tsab20© Crown Copyright 2015. This document is the author's final accepted/submitted version of the journal article. You are advised to consult the publisher's version if you wish to cite from it
Emission and propagation of Saturn kilometric radiation: magneto-ionic modes, beaming pattern and polarization state
The Cassini mission crossed the source region of the Saturn kilometric
radiation (SKR) on 17 October 2008. On this occasion, the Radio and Plasma Wave
Science (RPWS) experiment detected both local and distant radio sources, while
plasma parameters were measured in situ by the magnetometer (MAG) and the
Cassini Plasma Spectrometer (CAPS). A goniopolarimetric inversion was applied
to RPWS 3-antenna electric measurements to determine the wave vector k and the
complete state of polarization of detected waves. We identify broadband
extraordinary (X) as well as narrowband ordinary (O) mode SKR at low
frequencies. Within the source region, SKR is emitted just above the X mode
cutoff frequency in a hot plasma, with a typical electron-to-wave energy
conversion efficiency of 1% (2% peak). The knowledge of the k-vector is then
used to derive the locus of SKR sources in the kronian magnetosphere, that
shows X and O components emanating from the same regions. We also compute the
associated beaming angle at the source theta'=(k,-B) either from (i) in situ
measurements or a model of the magnetic field vector or from (ii) polarization
measurements. Obtained results, similar for both modes, suggest
quasi-perpendicular emission for local sources, whereas the beaming pattern of
distant sources appears as a hollow cone with a frequency-dependent constant
aperture angle: theta'=75{\deg}+/-15{\deg} below 300kHz, decreasing at higher
frequencies to reach theta'(1000kHz)=50{\deg}+/-25{\deg}. Finally, we
investigate quantitatively the SKR polarization state, observed to be strongly
elliptical at the source, and quasi-purely circular for sources located beyond
approximately 2 kronian radii. We show that conditions of weak mode coupling
are achieved along the ray path, under which the magneto-ionic theory
satisfactorily describes the evolution of the observed polarization
Risk of Complications in Patients Undergoing Completion Thyroidectomy after Hemithyroidectomy for Thyroid Nodule with Indeterminate Cytology: An Italian Multicentre Retrospective Study
There is still controversy as to whether patients undergoing a completion thyroidectomy
after a hemithyroidectomy for a thyroid nodule with an indeterminate cytology have a comparable, increased or decreased risk of complications compared to those submitted to primary thyroid surgery. The main aim of this study was to investigate this topic. Patients undergoing a thyroidectomy for thyroid nodular disease with an indeterminate cytology in four high-volume thyroid surgery centres in Italy, between January 2017 and December 2020, were retrospectively analysed. Based on the
surgical procedure performed, four groups were identified: the TT Group (total thyroidectomy), HT Group (hemithyroidectomy), CT Group (completion thyroidectomy) and HT + CT Group (hemithyroidectomy with subsequent completion thyroidectomy). A total of 751 patients were included. As for the initial surgery, 506 (67.38%) patients underwent a total thyroidectomy and 245 (32.62%) a hemithyroidectomy.
Among all patients submitted to a hemithyroidectomy, 66 (26.94%) were subsequently
submitted to a completion thyroidectomy. No statistically significant difference was found in terms of complications comparing both the TT Group with the HT + CT Group and the HT Group with the CT Group. The risk of complications in patients undergoing a completion thyroidectomy after a hemithyroidectomy for a thyroid nodule with an indeterminate cytology was comparable to that of patients submitted to primary thyroid surgery (both a total thyroidectomy and hemithyroidectomy)
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