This letter presents a case study addressing the comparison between different synthetic aperture radar (SAR) partial polarimetric options for tropical-vegetation cartography. These options include ...compact polarization (CP), dual polarization (DP), and alternating polarization (AP). They are all derived from fully polarimetric (FP) SAR data acquired by the airborne SAR (AIRSAR) sensor over the French Polynesian Tubuai Island. The classification approach is based on the support vector machine algorithm and is further validated by several ground surveys. For a single frequency band, FP data give significantly better results than any other partial polarimetric configuration. Among the partial polarimetric architectures, the CP mode performs best. In addition, the DP mode shows better performance than the AP mode, highlighting the value of the polarimetric differential phase. The combination of different frequency bands (P-, L-, and C-bands) holds the most significant improvement: The multifrequency diversity adds generally more information than the multipolarization diversity. A noticeable result is the major contribution of the C-band at VV polarization (the only polarization available at C-band with the AIRSAR data set used in this letter) to the classification performance, due to its ability to discriminate between Pinus and Falcata.
Magnetic resonance imaging (MRI) acquisition/processing techniques assess brain volumes to explore neurodegeneration in Alzheimer's disease (AD).
We examined the clinical utility of MSmetrix and ...investigated if automated MRI volumes could discriminate between groups covering the AD continuum and could be used as a predictor for clinical progression.
The Belgian Dementia Council initiated a retrospective, multi-center study and analyzed whole brain (WB), grey matter (GM), white matter (WM), cerebrospinal fluid (CSF), cortical GM (CGM) volumes, and WM hyperintensities (WMH) using MSmetrix in the AD continuum. Baseline (n = 887) and follow-up (FU, n = 95) T1-weighted brain MRIs and time-linked neuropsychological data were available.
The cohort consisted of cognitively healthy controls (HC, n = 93), subjective cognitive decline (n = 102), mild cognitive impairment (MCI, n = 379), and AD dementia (n = 313). Baseline WB and GM volumes could accurately discriminate between clinical diagnostic groups and were significantly decreased with increasing cognitive impairment. MCI patients had a significantly larger change in WB, GM, and CGM volumes based on two MRIs (n = 95) compared to HC (FU>24months, p = 0.020). Linear regression models showed that baseline atrophy of WB, GM, CGM, and increased CSF volumes predicted cognitive impairment.
WB and GM volumes extracted by MSmetrix could be used to define the clinical spectrum of AD accurately and along with CGM, they are able to predict cognitive impairment based on (decline in) MMSE scores. Therefore, MSmetrix can support clinicians in their diagnostic decisions, is able to detect clinical disease progression, and is of help to stratify populations for clinical trials.
Importance Blood transfusion is a mainstay of therapy for trauma-induced coagulopathy, but the optimal modalities for plasma transfusion in the prehospital setting remain to be defined. Objective To ...determine whether lyophilized plasma transfusion can reduce the incidence of trauma-induced coagulopathy compared with standard care consisting of normal saline infusion. Design, Setting, and Participants This randomized clinical trial was performed at multiple centers in France involving prehospital medical teams. Participants included 150 adults with trauma who were at risk for hemorrhagic shock and associated coagulopathy between April 1, 2016, and September 30, 2019, with a 28-day follow-up. Data were analyzed from November 1, 2019, to July 1, 2020. Intervention Patients were randomized in a 1:1 ratio to receive either plasma or standard care with normal saline infusion (control). Main Outcomes and Measures The primary outcome was the international normalized ratio (INR) on arrival at the hospital. Secondary outcomes included the need for massive transfusion and 30-day survival. As a safety outcome, prespecified adverse events included thrombosis, transfusion-related acute lung injury, and transfusion-associated circulatory overload. Results Among 150 randomized patients, 134 were included in the analysis (median age, 34 IQR, 26-49 years; 110 men 82.1%), with 68 in the plasma group and 66 in the control group. Median INR values were 1.21 (IQR, 1.12-1.49) in the plasma group and 1.20 (IQR, 1.10-1.39) in the control group (median difference, −0.01 IQR, −0.09 to 0.08;P = .88). The groups did not differ significantly in the need for massive transfusion (7 10.3% vs 4 6.1%; relative risk, 1.78 95% CI, 0.42-8.68;P = .37) or 30-day survival (hazard ratio for death, 1.07 95% CI, 0.44-2.61;P = .89). In the full intention-to-treat population (n = 150), the groups did not differ in the rates of any of the prespecified adverse events. Conclusions and Relevance In this randomized clinical trial including severely injured patients at risk for hemorrhagic shock and associated coagulopathy, prehospital transfusion of lyophilized plasma was not associated with significant differences in INR values vs standard care with normal saline infusion. Nevertheless, these findings show that lyophilized plasma transfusion is a feasible and safe procedure for this patient population. Trial Registration ClinicalTrials.gov Identifier:NCT02736812
Cometary atmospheres are produced by the outgassing of material, mainly H sub(2)O, CO, and CO sub(2) from the nucleus of the comet under the energy input from the Sun. Subsequent photochemical ...processes lead to the production of other species generally absent from the nucleus, such as OH. Although all comets are different, they all have a highly rarefied atmosphere, which is an ideal environment for nonthermal photochemical processes to take place and influence the detailed state of the atmosphere. We develop a Monte Carlo model of the coma photochemistry. We compute the energy distribution functions (EDF) of the metastable O( super(1)D) and O( super(1)S) species and obtain the red (630 nm) and green (557.7 nm) spectral line shapes of the full coma, consistent with the computed EDFs and the expansion velocity. We show that both species have a severely non-Maxwellian EDF, that results in broad spectral lines and the suprathermal broadening dominates due to the expansion motion. We apply our model to the atmosphere of comet C/1996 B2 (Hyakutake) and 103P/Hartley 2. The computed width of the green line, expressed in terms of speed, is lower than that of the red line. This result is comparable to previous theoretical analyses, but in disagreement with observations. We explain that the spectral line shape does not only depend on the exothermicity of the photochemical production mechanisms, but also on thermalization, due to elastic collisions, reducing the width of the emission line coming from the O( super(1)D) level, which has a longer lifetime.
A new species of Elasmopus is described and figured from specimens collected in different benthic communities of Arcachon Bay. It can be distinguished from its closest relative E. rapax by the palmar ...ornamentation of male gnathopod 2 propodus (shelf and 2 teeth). It preferentially lives on hard bottoms (in mussel fouling of navigation buoys, Sabellaria spinulosa reefs, algal rocky bottoms, Laminaria and Saccorhiza bulbs and as epibiont on the carapace of Maja brachydactyla) but also less abundantly on naked sandy bottoms. An identification key of Atlantic and Mediterranean European species is also given.
The aims of this study were to highlight the impact of minor structural differences (e.g. an aminoacid side chain enlargement by one methylene group), on ion dissociation under collision-induced ...dissociation conditions, and to determine the underlying chemical mechanisms. Therefore, we compared fragmentations of deprotonated aspartic and glutamic acids generated in negative electrospray ionization. Energy-resolved mass spectrometry breakdown curves were recorded and MS
experiments performed on an Orbitrap Fusion for high-resolution and high-mass accuracy measurements. Activated fragmentations were performed using both the resonant and non-resonant excitation modes (i.e., CID and HCD, respectively) in order to get complementary information on the competitive and consecutive dissociative pathways. These experiments showed a specific loss of ammonia from the activated aspartate but not from the activated glutamate. We mainly focused on this specific observed loss from aspartate. Two different mechanisms based on intramolecular reactions (similar to those occurring in organic chemistry) were proposed, such as intramolecular elimination (i.e. Ei-like) and nucleophilic substitution (i.e. SNi-like) reactions, respectively, yielding anions as fumarate and α lactone from a particular conformation with the lowest steric hindrance (i.e. with antiperiplanar carboxyl groups). The detected deaminated aspartate anion can then release CO
as observed in the MS
experimental spectra. However, quantum calculations did not indicate the formation of such a deaminated aspartate product ion without loss of carbon dioxide. Actually, calculations displayed the double neutral (NH
+CO
) loss as a concomitant pathway (from a particular conformation) with relative high activation energy instead of a consecutive process. This disagreement is apparent since the concomitant pathway may be changed into consecutive dissociations according to the collision energy i.e., at higher collision energy and at lower excitation conditions, respectively. The latter takes place by stabilization of the deaminated aspartate solvated with two residual molecules of water (present in the collision cell). This desolvated anion formed is an α lactone substituted by a methylene carboxylate group. The vibrational excitation acquired by (D-H)-NH
during its isolation is enough to allow its prompt decarboxylation with a barrier lower than 8.4kJ/mol. In addition, study of glutamic acid-like diastereomers constituted by a cyclopropane, hindering any side chain rotation, confirms the impact of the three-dimensional geometry on fragmentation pathways. A significant specific loss of water is only observed for one of these diastereomers. Other experiments, such as stable isotope labeling, need to be performed to elucidate all the observed losses from activated aspartate and glutamate anions. These first mechanistic interpretations enhance understanding of this dissociative pathway and underline the necessity of studying fragmentation of a large number of various compounds to implement properly new algorithms for de novo elucidation of unknown metabolites.
Human gingival fibroblasts (HGFs) cell sheets have a potential use for in vivo wound healing due to the ability of HGFs to adopt a contractile phenotype which is typically expressed during ...extracellular matrix tissue remodeling. For this purpose, we developed a chemically detachable platform based on poly(allylamine hydrochloride)/poly(styrene sulfonate) multilayer film built on a sacrificial precursor film which served as a substrate for HGF cell layer formation. The sacrificial precursor film, based on disulfide-containing polycation and polyanion, is degradable under mild conditions compatible for cell sheet detachment. Cellular viability and cell phenotype analysis of HGF show that the designed platform promotes cell phenotype switch into contractile phenotype, maintained after cell sheet lift-off. This contractile phenotype is acquired by fibroblasts during in vivo wound healing and tissue remodeling. HGFs cell sheet fragments, obtained by this detachment process, could be cultured later on showing a good retention of the typical spindle-shape of differentiated cells after 10 days of culture. HGFs cell sheets have great potential applications as autologous substrates for tissue repair and cellular synthetic platforms for research on connective tissue diseases or evaluation of novel therapeutic agents.
Our study aimed to explore the association between early hyperoxemia of the first 24 h on outcomes in patients with severe blunt chest trauma.
In a level I trauma center, we conducted a retrospective ...study of 426 consecutive patients. Hyperoxemic groups were classified in severe (average PaO2 ≥ 200 mmHg), moderate (≥150 and < 200 mmHg) or mild (≥ 100 and < 200 mmHg) and compared to control group (≥60 and < 100 mmHg) using a propensity score based analysis. The first endpoint was the incidence of a composite outcome including death and hospital-acquired pneumonia occurring from admission to day 28. The secondary endpoints were the incidence of death, the number of hospital-acquired pneumonia, mechanical ventilation-free days and intensive care unit-free day at day 28.
The incidence of the composite endpoint was lower in the severe hyperoxemia group(OR, 0.25; 95%CI, 0.09–0.73; P < 0.001) compared with control. The 28-day mortality incidence was lower in severe (OR, 0.23; 95%CI, 0.08–0.68; P < 0.001) hyperoxemia group (OR, 0.41; 95%CI, 0.17–0.97; P = 0.04). Significant association was found between hyperoxemia and secondary outcomes.
In our cohort early hyperoxemia during the first 24 h of admission after severe blunt chest trauma was not associated with worse outcome.
•Effect of hyperoxia remains unexplored in blunt chest trauma•Early hyperoxia may have an anti-bacterial and anti-inflammatory effect•Early hyperoxia is associated with lower incidence of pneumonia after chest trauma•Severe blunt chest trauma may benefit of early hyperoxia
We have carried out a multisite campaign to measure oscillations in the F5 star Procyon A. We obtained high-precision velocity observations over more than three weeks with 11 telescopes, with almost ...continuous coverage for the central 10 days. This represents the most extensive campaign so far organized on any solar-type oscillator. We describe in detail the methods we used for processing and combining the data. These involved calculating weights for the velocity time series from the measurement uncertainties and adjusting them in order to minimize the noise level of the combined data. The time series of velocities for Procyon shows the clear signature of oscillations, with a plateau of excess power that is centered at 0.9 mHz and is broader than has been seen for other stars. The mean amplitude of the radial modes is image cm s super(-1) (2.0 times solar), which is consistent with previous detections from the ground and by the WIRE spacecraft, and also with the upper limit set by the MOST spacecraft. The variation of the amplitude during the observing campaign allows us to estimate the mode lifetime to be image days. We also find a slow variation in the radial velocity of Procyon, with good agreement between different telescopes. These variations are remarkably similar to those seen in the Sun, and we interpret them as being due to rotational modulation from active regions on the stellar surface. The variations appear to have a period of about 10 days, which presumably equals the stellar rotation period or, perhaps, half of it. The amount of power in these slow variations indicates that the fractional area of Procyon covered by active regions is slightly higher than for the Sun.
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