We report on the development of a highly directional, narrow energy band, short time duration proton beam operating at high repetition rate. The protons are generated with an ultrashort-pulse laser ...interacting with a solid target and converted to a pencil-like narrow-band beam using a compact magnet-based energy selector. We experimentally demonstrate the production of a proton beam with an energy of 500 keV and energy spread well below 10Formula: see text, and a pulse duration of 260 ps. The energy loss of this beam is measured in a 2 Formula: see textm thick solid Mylar target and found to be in good agreement with the theoretical predictions. The short time duration of the proton pulse makes it particularly well suited for applications involving the probing of highly transient plasma states produced in laser-matter interaction experiments. This proton source is particularly relevant for measurements of the proton stopping power in high energy density plasmas and warm dense matter.
Background
Transient and persistent acute kidney injury (AKI) could share similar physiopathological mechanisms. The objective of our study was to assess prognostic impact of AKI duration on ICU ...mortality.
Design
Retrospective analysis of a prospective database via cause-specific model, with 28-day ICU mortality as primary end point, considering discharge alive as a competing event and taking into account time-dependent nature of renal recovery. Renal recovery was defined as a decrease of at least one KDIGO class compared to the previous day.
Setting
23 French ICUs.
Patients
Patients of a French multicentric observational cohort were included if they suffered from AKI at ICU admission between 1996 and 2015.
Intervention
None.
Results
A total of 5242 patients were included. Initial severity according to KDIGO creatinine definition was AKI stage 1 for 2458 patients (46.89%), AKI stage 2 for 1181 (22.53%) and AKI stage 3 for 1603 (30.58%). Crude 28-day ICU mortality according to AKI severity was 22.74% (
n
= 559), 27.69% (
n
= 327) and 26.26% (
n
= 421), respectively. Renal recovery was experienced by 3085 patients (58.85%), and its rate was significantly different between AKI severity stages (
P
< 0.01). Twenty-eight-day ICU mortality was independently lower in patients experiencing renal recovery CSHR 0.54 (95% CI 0.46–0.63),
P
< 0.01. Lastly, RRT requirement was strongly associated with persistent AKI whichever threshold was chosen between day 2 and 7 to delineate transient from persistent AKI.
Conclusions
Short-term renal recovery, according to several definitions, was independently associated with higher mortality and RRT requirement. Moreover, distinction between transient and persistent AKI is consequently a clinically relevant surrogate outcome variable for diagnostic testing in critically ill patients.
Laser-driven ion acceleration has been an active research area in the past two decades with the prospects of designing novel and compact ion accelerators. Many potential applications in science and ...industry require high-quality, energetic ion beams with low divergence and narrow energy spread. Intense laser ion acceleration research strives to meet these challenges and may provide high charge state beams, with some successes for carbon and lighter ions. Here we demonstrate the generation of well collimated, quasi-monoenergetic titanium ions with energies ∼145 and 180 MeV in experiments using the high-contrast (<10−9) and high-intensity ( 6 × 10 20 W cm − 2 ) Trident laser and ultra-thin (∼100 nm) titanium foil targets. Numerical simulations show that the foils become transparent to the laser pulses, undergoing relativistically induced transparency (RIT), resulting in a two-stage acceleration process which lasts until ∼2 ps after the onset of RIT. Such long acceleration time in the self-generated electric fields in the expanding plasma enables the formation of the quasi-monoenergetic peaks. This work contributes to the better understanding of the acceleration of heavier ions in the RIT regime, towards the development of next generation laser-based ion accelerators for various applications.
Human enterovirus 71 (EV-71) is a cause of seasonal epidemics of hand, foot and mouth disease, and of less common but severe neurological manifestations. Uncertainty persists regarding the ...circulation of virus populations in several geographical areas and the timescale of their dissemination. We determined EV-71 sequences at loci 1D (VP1 capsid protein) and 3CD (non-structural proteins) in 86 strains recovered in Austria, France and Germany and performed an evolutionary genetic study of extant virus populations. Phylogenetic analyses positioned 78 of the 86 sequences within two clades among subgenogroups C1 and C2. A minor sequence cluster was assigned to subgenogroup C4. Analyses incorporating the available sequences estimated the substitution rate in genogroup C at 3.66 x 10(-3) and 4.46 x 10(-3) substitutions per site year(-1) for loci 1D and 3CD, respectively, assuming a relaxed molecular-clock model for sequence evolution. Most of the 'European' strains belonged to clades C1b and C2b, which originated in 1994 95 % confidence interval (CI), 1992.7-1995.8 and 2002 (95 % CI, 2001.6-2003.8), respectively. Estimates of divergence times for locus 3CD were consistent with those measured for locus 1D. Intertwining between clades representing EV-71 subgenogroups and clades corresponding to other enterovirus types (notably early coxsackievirus A prototype strains) in the 3CD phylogeny is highly indicative of ancestral recombination events. Incongruent phylogenetic patterns estimated for loci 1D and 3CD show that a single tree cannot model the epidemic history of circulating EV-71 populations. The evolutionary timescale of genogroup C estimated for both loci was measured only in decades, indicating recent dissemination.
The root‐knot nematodes are the most devastating worms to worldwide agriculture with Meloidogyne incognita being the most widely distributed and damaging species. This parasitic and ecological ...success seems surprising given its supposed obligatory clonal reproduction. Clonal reproduction has been suspected based on cytological observations but, so far, never confirmed by population genomics data. As a species, M. incognita is highly polyphagous with thousands of host plants. However, different M. incognita isolates present distinct and overlapping patterns of host compatibilities. Historically, four “host races” had been defined as a function of ranges of compatible and incompatible plants. In this study, we used population genomics to assess whether (a) reproduction is actually clonal in this species, (b) the host races follow an underlying phylogenetic signal or, rather represent multiple independent transitions, and (c) how genome variations associate with other important biological traits such as the affected crops and geographical distribution. We sequenced the genomes of 11 M. incognita isolates across Brazil that covered the four host races in replicates. By aligning the genomic reads of these isolates to the M. incognita reference genome assembly, we identified point variations. Analysis of linkage disequilibrium and 4‐gametes test showed no evidence for recombination, corroborating the clonal reproduction of M. incognita. The few point variations between the isolates showed no significant association with the host races, the geographical origin of the samples, or the crop on which they have been collected. Addition of isolates from other locations around the world confirmed this lack of underlying phylogenetic signal. This suggests multiple gains and losses of parasitic abilities and adaptations to different environments account for the broad host spectrum and wide geographical distribution of M. incognita and thus to its high economic impact. This surprising adaptability without sex poses both evolutionary and agro‐economic challenges.
Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet the effects of river network rearrangements on dispersal and lineage diversification remain poorly ...understood. We integrated an unprecedented occurrence dataset of 4,967 species with a newly compiled, time-calibrated phylogeny of South American freshwater fishes-the most species-rich continental vertebrate fauna on Earth-to track the evolutionary processes associated with hydrogeographic events over 100 Ma. Net lineage diversification was heterogeneous through time, across space, and among clades. Five abrupt shifts in net diversification rates occurred during the Paleogene and Miocene (between 30 and 7 Ma) in association with major landscape evolution events. Net diversification accelerated from the Miocene to the Recent (c. 20 to 0 Ma), with Western Amazonia having the highest rates of in situ diversification, which led to it being an important source of species dispersing to other regions. All regional biotic interchanges were associated with documented hydrogeographic events and the formation of biogeographic corridors, including the Early Miocene (c. 23 to 16 Ma) uplift of the Serra do Mar and Serra da Mantiqueira and the Late Miocene (c. 10 Ma) uplift of the Northern Andes and associated formation of the modern transcontinental Amazon River. The combination of high diversification rates and extensive biotic interchange associated with Western Amazonia yielded its extraordinary contemporary richness and phylogenetic endemism. Our results support the hypothesis that landscape dynamics, which shaped the history of drainage basin connections, strongly affected the assembly and diversification of basin-wide fish faunas.
In the context of the radioactive waste management in deep geological formations, U(VI) retention by intact Callovo-Oxfordian claystone (COx) was studied by percolation-type experiments at 20 and ...80 °C. The experimental results were confronted with modelling prediction based on a published adsorption model developed from dispersed media in the 20–80 °C temperature range. For the experiments at 20 °C, the adsorption model allowed to explain the results for the intact system; the retention was weak (Rd ∼ 10 L•kg−1) and the analysis of the COx phases at the end of the experiment confirmed a retention of U by the clay fraction. The adsorption model in temperature also explained the observed trend of increasing retention with increasing temperature. However, it underestimated the temperature effect on the adsorption of U(VI) by the COx clay fraction, and other phases contributed to the retention. Solid-state analysis of the percolation-doped samples indicated a reactivity in the order pyrite>clay>calcite phases. The transposition of the knowledge at 20 °C from the dispersed system to the intact medium was therefore not possible at 80 °C for the studied U(VI)/COx system.
•A setup allowing to obtain retention data in compact clays at 80 °C was designed.•The adsorption model is applicable at 20 °C but underestimates the retention at 80 °C.•Contrary to 20 °C, U adsorption on the clay fraction is not the only retention process at 80 °C.•The reactivity varies according to the order pyrite> clays> calcite at 80 °C.
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