UO2 samples doped with 6, 11, 22 mol% lanthanum were examined before and after air oxidation. To verify the formation of uranium–lanthanum‐mixed oxide solid solutions, powder X‐ray diffraction (XRD) ...analyses of the crystalline phases in the materials were carried out. The presence of oxygen vacancies in the La‐doped UO2 samples was identified by Raman spectrometry. It was evidenced by changes induced in the Raman spectra by air oxidation. This latter was carried out either by increasing the Raman laser power or by thermally treating the samples at 500 K for 370 h. In addition, oxidation behavior differences of pure and La‐doped UO2 samples were reported by comparing XRD and Raman results of the samples before and after air oxidation. It was shown that the concentration of the M4O9 (M: U, La) phase increased with increasing content of La, whereas inhibition for the formation of M3O8 phase was observed.
Recently, novel container-less laser heating experimental data have been published on the melting behaviour of pure PuO2 and PuO2-rich compositions in the uranium dioxide–plutonium dioxide system. ...Such data showed that previous data obtained by more traditional furnace heating techniques were affected by extensive interaction between the sample and its containment. It is therefore paramount to check whether data so far used by nuclear engineers for the uranium-rich side of the pseudo-binary dioxide system can be confirmed or not. In the present work, new data are presented both in the UO2-rich part of the phase diagram, most interesting for the uranium–plutonium dioxide based nuclear fuel safety, and in the PuO2 side. The new results confirm earlier furnace heating data in the uranium-dioxide rich part of the phase diagram, and more recent laser-heating data in the plutonium-dioxide side of the system. As a consequence, it is also confirmed that a minimum melting point must exist in the UO2–PuO2 system, at a composition between x(PuO2)=0.4 and x(PuO2)=0.7 and 2900K⩽T⩽3000K. Taking into account that, especially at high temperature, oxygen chemistry has an effect on the reported phase boundary uncertainties, the current results should be projected in the ternary U–Pu–O system. This aspect has been extensively studied here by X-ray diffraction and X-ray absorption spectroscopy. The current results suggest that uncertainty bands related to oxygen behaviour in the equilibria between condensed phases and gas should not significantly affect the qualitative trend of the current solid–liquid phase boundaries.
Context.
Transition disks are protoplanetary disks with dust-depleted cavities, possibly indicating substantial clearing of their dust content by a massive companion. For several known transition ...disks, dark regions interpreted as shadows have been observed in scattered light imaging and are hypothesized to originate from misalignments between distinct regions of the disk.
Aims.
We aim to investigate the presence of misalignments in transition disks. We study the inner disk (<1 au) geometries of a sample of 20 well-known transition disks with Very Large Telescope Interferometer (VLTI) GRAVITY observations and use complementary
12
CO and
13
CO molecular line archival data from the Atacama Large Millimeter/submillimeter Array (ALMA) to derive the orientation of the outer disk regions (>10 au).
Methods.
We fit simple parametric models to the visibilities and closure phases of the GRAVITY data to derive the inclination and position angle of the inner disks. The outer disk geometries were derived from Keplerian fits to the ALMA velocity maps and compared to the inner disk constraints. We also predicted the locations of expected shadows for significantly misaligned systems.
Results.
Our analysis reveals six disks to exhibit significant misalignments between their inner and outer disk structures. The predicted shadow positions agree well with the scattered light images of HD 100453 and HD 142527, and we find supporting evidence for a shadow in the south of the disk around CQ Tau. In the other three targets for which we infer significantly misaligned disks, V1247 Ori, V1366 Ori, and RY Lup, we do not see any evident sign of shadows in the scattered light images. The scattered light shadows observed in DoAr 44, HD 135344 B, and HD 139614 are consistent with our observations, yet the underlying morphology is likely too complex to be described properly by our models and the accuracy achieved by our observations.
Conclusions.
The combination of near infrared and submillimeter interferometric observations allows us to assess the geometries of the innermost disk regions and those of the outer disk. Whereas we can derive precise constraints on the potential shadow positions for well-resolved inner disks around Herbig Ae/Be stars, the large statistical uncertainties for the marginally resolved inner disks around the T Tauri stars of our sample make it difficult to extract conclusive constraints for the presence of shadows in these systems.
Context.
Planets form during the first few Myr of the evolution of the star-disk system, possibly before the end of the embedded phase. The properties of very young disks and their subsequent ...evolution reflect the presence and properties of their planetary content.
Aims.
We present a study of the Class II/F disk population in L1688, the densest and youngest region of star formation in Ophiuchus. We also compare it to other well-known nearby regions of different ages, namely Lupus, Chamaeleon I, Corona Australis, Taurus and Upper Scorpius.
Methods.
We selected our L1688 sample using a combination of criteria (available ALMA data,
Gaia
membership, and optical and near-IR spectroscopy) to determine the stellar and disk properties, specifically stellar mass (
M
⋆
), average population age, mass accretion rate (
Ṁ
acc
) and disk dust mass (
Ṁ
dust
). We applied the same procedure in a consistent manner to the other regions.
Results.
In L1688 the relations between
Ṁ
acc
and
M
⋆
,
M
dust
and
M
⋆
, and
Ṁ
acc
and
M
dust
have a roughly linear trend with slopes 1.8–1.9 for the first two relations and ~1 for the third, which is similar to what found in the other regions. When ordered according to the characteristic age of each region, which ranging from ~ 0.5 to ~5 Myr,
Ṁ
acc
decreases as
t
−1
, when corrected for the different stellar mass content;
M
dust
follows roughly the same trend, ranging between 0.5 and 5 Myr, but has an increase of a factor of ~3 at ages of 2–3 Myr. We suggest that this could result from an earlier planet formation, followed by collisional fragmentation that temporarily replenishes the millimeter-size grain population. The dispersion of
Ṁ
acc
and
M
dust
around the best-fitting relation with
M
⋆
, as well as that of
Ṁ
acc
versus
M
dust
are equally large. When adding all the regions together to increase the statistical significance, we find that the dispersions have continuous distributions with a log-normal shape and similar widths (~0.8 dex).
Conclusions.
This detailed study of L1688 confirms the general picture of Class II/F disk properties and extends it to a younger age. The amount of dust observed at ~1 Myr is not sufficient to assemble the majority of planetary systems, which suggests an earlier formation process for planetary cores. The dust mass traces to a large extent the disk gas mass evolution, even if the ratio
M
dust
/
M
disk
at the earliest age (0.5–1 Myr) is not known. Two properties are still not understood: the steep dependence of
Ṁ
acc
and
M
dust
on
M
⋆
and the cause of the large dispersion in the three relations analyzed in this paper, in particular that of the
Ṁ
acc
versus
M
dust
relation.
Abstract Reanalyses are utilized for calculating climatological trends due to their focus on temporal consistency. ERA5 reanalysis family has proven to be a valuable and widely used product for trend ...extraction. This study specifically examines long‐term trends in total annual precipitation across two climatic hotspots: the Alps and Italy. It is acknowledged by reanalysis producers that variations in the observational systems used for data assimilation impact water cycle components like precipitation. This understanding highlights the need of assessing to what extent temporal variations in ERA5 precipitation amounts are solely a result of climate variations and the influence of changes in the observational system impacting simulation accuracy. Our research examines the differences between ERA5 and similar reanalyses against homogenized, trend‐focused observational datasets. We find that discerning the climatological signal within ERA5 adjustments for observational system variations is challenging. The trend in ERA5 from 1940 to 1970 shows distinct patterns over the Alps and, to a lesser extent, Italy, diverging from later ERA5 trends and those in other reanalyses. Notably, ERA5 shows an increasing, although nonlinear, trend in the deviation between ERA5 and the observational datasets. Improving future reanalysis interpretability could involve adopting a model‐only integration for the same period, akin to the ERA‐20C and ERA‐20CM approach.
Fabry disease is an X-linked lysosomal deficiency of α-galactosidase A that results in cellular accumulation of galactoconjugates, mainly globotriaosylceramide, particularly in blood vessels. ...Neuroradiological findings include ischemic stroke, white matter lesions, vascular abnormalities (vertebrobasilar dolichoectasia and vessel tortuosity), and posterior thalamus involvement (the so called
pulvinar sign
). The purpose of our study was to investigate the presence of the increased pulvinar signal intensity on T1-weighted imaging –
pulvinar sign
and its relationship with other clinical findings, in a non-selected cohort of Fabry patients.
Methods
We performed a prospective analysis of two populations of patients (36 subjects) with Fabry disease. Patients were followed-up at the Department of Internal Medicine of the Bichat Hospital in Paris (France) and at the Neurological Clinic of the University Hospital of Padova (Italy). Brain MR studies of each patient included T1- and T2- weighted images, FLAIR sequences, and in some cases diffusion weighted images.
Results
A total of 36 patients (16 males, 20 females) were investigated in 14 families. The
pulvinar sign
was found in 5 male patients, but not in female patients. Seven patients had had at least one stroke (territorial or lacunar). There was no correlation between stroke and the pulvinar sign. All patients with the
pulvinar sign
had hypertrophic cardiomyopathy. Four patients out of five with the
pulvinar sign
were on dialysis or had a kidney transplantation.
Conclusions
Our findings suggest that the
pulvinar sign
is a highly specific sign of Fabry disease, found in male patients with cardiac signs and severe kidney involvement.
Adult-onset Still's disease (AOSD) is a rare inflammatory condition characterized by fever, rash, and arthritis. Because of its rarity, clinical trials are inherently small and often uncontrolled. ...Our objective was to develop recommendations for the use of interleukin (IL)-1 inhibitors in the management of patients with AOSD, based on the best evidence and expert opinion.
A panel of 10 experts (9 rheumatologists and 1 pediatrician) was established. The first step was dedicated to a comprehensive literature review and development of statements. Two separate literature searches were performed on the MEDLINE (Pubmed), EMBASE, and BIOSIS databases through April 2018 to identify (1) differences and similarities between AOSD and pediatric Still's disease (systemic juvenile idiopathic arthritis SJIA) and (2) the efficacy and safety of IL-1 inhibitors in AOSD treatment. In the second step, the statements were submitted in a Delphi process to a panel of 67 rheumatologists. Consensus threshold was set at 66%: positive, > 66% of voters selected scores 3 to 5; negative, > 66% of voters selected scores 1 or 2. In the third step, the voting results were analyzed, and the statements were finalized.
Eleven statements were developed. Forty-six of 67 rheumatologists (72%) participated in the Delphi process. A positive consensus was reached after the first round of voting and was full (> 95%) on the majority of statements. A large consensus was achieved in considering AOSD and SJIA as the same disease. The use of anti-IL-1 therapies in refractory patients was considered quite safe and effective both as the first and as a subsequent line of biologic treatment, especially in systemic patients. Because of the lack of head-to-head comparisons, a different profile of efficacy among IL-1 inhibitors could not be established. There was a large consensus that failure of the first IL-1 inhibitor does not preclude response to another one. The lack of studies comparing early versus late treatment did not allow to draw conclusions; however, data from SJIA suggest a better response in early treatment.
The Delphi method was used to develop recommendations that we hope will help clinicians in the management of patients with AOSD refractory to conventional therapies.
Identification of new drugs is strongly needed for sarcomas. Insulin-like growth factor-I receptor (IGF-IR) was found to provide a major contribution to the malignant behavior of these tumors, ...therefore representing a very promising therapeutic target. In this study, we analyzed the therapeutic potential of a novel kinase inhibitor of IGF-IR, NVP-AEW541, in Ewing's sarcoma, osteosarcoma, and rhabdomyosarcoma, the three most frequent solid tumors in children and adolescents. NVP-AEW541 inhibits IGF-I-mediated receptor activation and downstream signaling. Ewing's sarcoma cells were generally found to be more sensitive to the effects of this drug compared with rhabdomyosarcoma and osteosarcoma, in agreement with the high dependency of this neoplasm to IGF-IR signaling. NVP-AEW541 induced a G1 cell cycle block in all cells tested, whereas apoptosis was observed only in those cells that show a high level of sensitivity. Concurrent exposure of cells to NVP-AEW541 and other chemotherapeutic agents resulted in positive interactions with vincristine, actinomycin D, and ifosfamide and subadditive effects with doxorubicin and cisplatin. Accordingly, combined treatment with NVP-AEW541 and vincristine significantly inhibited tumor growth of Ewing's sarcoma xenografts in nude mice. Therefore, results encourage inclusion of this drug especially in the treatment of patients with Ewing's sarcoma. For the broadest applicability and best efficacy in sarcomas, NVP-AEW541 may be combined with vincristine, actinomycin D, and ifosfamide, three major drugs in the treatment of sarcomas.
Background and Aims
The light‐struck taste is a fault occurring in light‐exposed white wine containing methionine and a high concentration of riboflavin (RF) and bottled in clear bottles. These ...conditions induce the formation of methanethiol and dimethyl disulfide, responsible for a cabbage‐like aroma. In order to decrease the risk of wine spoilage, a low concentration of RF should be obtained in wine either by preventing RF release from yeast during winemaking or by removing RF from wine.
Methods and Results
Fifteen commercial Saccharomyces strains intended for the wine industry were tested for RF production, which was also evaluated when two yeast‐based nutrients were added into the must for one of these strains. The RF released during vinification was strain‐dependent and a concentration from 30 to 170 μg/L was found in wine. A high concentration of RF was released in the presence of the yeast‐based nutrients because of either the yeast metabolism or the RF contained in the nutrient itself. The ability of different inorganic (bentonite, charcoal, zeolite, kaolin) and organic adjuvants (egg‐white proteins, polyvinylpolypyrrolidone) to deplete RF in wine was evaluated. A relatively low level of charcoal (50 mg/L) removed up to 60% of RF in wine, although its effectiveness was related to the charcoal source. A high concentration of bentonite (1 g/L) was needed to effectively decrease the risk of wine spoilage.
Conclusions
A critical RF concentration in white wine can be prevented by applying one or more approaches in winemaking: using low RF‐producing yeast strains in fermentation, selecting suitable yeast nutrients or adsorbing RF by insoluble charcoal or bentonite.
Significance of the Study
The research highlights suitable tools to prevent light‐struck taste in white winemaking.
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