Search

Purpose [18F]-2-Fluoro-2-deoxy-D-glucose PET/CT (FDG PET/CT) is a sensitive and quantitative technic for detecting inflammatory process. Glucose uptake is correlated with an increased anaerobic glycolysis seen in activated inflammatory cells such as monocytes, lymphocytes, and granulocytes. The aim of the study was to assess the inflammatory status at the presumed peak of the inflammatory phase in non-critically ill patients requiring admission for COVID-19. Methods Patients admitted with COVID-19 were prospectively enrolled. FDG PET/CT was performed from day 6 to day 14 of the onset of symptoms. Depending on FDG PET/CT findings, patients’ profiles were classified as “inflammatory” or “low inflammatory.” FDG PET/CT data were compared with chest CT evolution and short-term clinical outcome. All inflammatory sites were reported to screen potential extra-pulmonary tropism. Results Thirteen patients were included. Maximum standardized uptake values ranged from 4.7 to 16.3 in lungs. All patients demonstrated increased mediastinal lymph nodes glucose uptake. Three patients (23%) presented mild nasopharyngeal, two patients (15%) bone marrow, and five patients (38%) splenic mild increase in glucose uptake. No patient had significant digestive focal or segmental glucose uptake. There was no significant physiological myocardial glucose uptake in all patients except one. There was no correlation between PET lung inflammatory status and chest CT evolution or short-term clinical outcome. Conclusion Inflammatory process at the presumed peak of the inflammatory phase in COVID-19 patients is obvious in FDG PET/CT scans. Glucose uptake is heterogeneous and typically focused on lungs. Trial registration NCT04441489. Registered 22 June 2020 (retrospectively registered). Electronic supplementary material The online version of this article (10.1007/s00259-020-04968-8) contains supplementary material, which is available to authorized users.

ObjectiveInformation regarding the impact of COVID-19 in children with brain-based disabilities, or those at risk of developing such conditions, remains scarce. The objective was to evaluate if children with brain-based disabilities are more likely to (1) develop COVID-19, (2) develop complications from the disease, and (3) to have a poorer prognosis.Study designWe conducted a rapid review using search strategies iteratively developed and tested by an experienced medical information specialist in consultation with the review team and a panel of knowledge users. Searches were initially performed on April 18th, 2021, and updated on October 31st, 2020. Four reviewers individually performed study selection using pilot-tested standardized forms. Single reviewers extracted the data using a standardized extraction form that included study characteristics, patients’ characteristics, and outcomes reported.ResultsWe identified 1448 publications, of which 29 were included. Studies reported data on 2288 COVID-19 positive children, including 462 with a brain-based disability, and 72 at risk of developing such disability. Overall, the included studies showed a greater risk to develop severe COVID-19 disease in children with brain-based disabilities. Although mortality is very low, the case-fatality rate appeared to be higher in children with disabilities compared to children without disabilities.ConclusionsOur review shows that children with brain-based disabilities are overrepresented in hospitalization numbers compared to children without disabilities. However, most studies included children that were hospitalized from COVID-19 in secondary and tertiary care centers. Results of this review should therefore be interpreted with caution.

In this work we explore the new catalog of galactic open clusters that became available recently, containing 1750 clusters that have been re-analysed using the Gaia DR2 catalog to determine the stellar memberships. We used the young open clusters as tracers of spiral arms and determined the spiral pattern rotation speed of the Galaxy and the corotation radius, the strongest Galactic resonance. The sample of open clusters used here increases the last one from Dias et al. (2019) used in the previous determination of the pattern speed by dozens objects. In addition, the distances and ages values are better determined, using improvements to isochrone fitting and including an updated extinction polynomial for the Gaia DR2 photometric band-passes, and the Galactic abundance gradient as a prior for metallicity. In addition to the better age determinations, the catalog contains better positions in the Galactic plane and better proper motions. This allow us to discuss not only the present space distribution of the clusters, but also the space distribution of the clusters's birthplaces, obtained by integration of the orbits for a time equal to their age. The value of the rotation velocity of the arms ($28.5 \pm 1.0$ km s$^{-1}$ kpc$^{-1}$) implies that the corotation radius ($R_c$) is close to the solar Galactic orbit ($R_c/R_0 = 1.01\pm0.08$), which is supported by other observational evidence discussed in this text. A simulation is presented, illustrating the motion of the clusters in the reference frame of corotation. We also present general statistics of the catalog of clusters, like spatial distribution, distribution relative to height from the Galactic plane, and distribution of ages and metallicity. An important feature of the space distribution, the corotation gap in the gas distribution and its consequences for the young clusters, is discussed., Comment: 19 pages, 10 figures, 1 table. Accepted for publication in Frontiers in Astronomy and Space Sciences

This paper describes a technique designed to measure the in-situ acceleration signals that will be used to drive a road simulator in the study of road bike vibration transmission in a laboratory setting. To measure the signals, a bike mounted by a cyclist and towed by a motor vehicle is used. A road simulator using actuators driven by a digital signal is described. The impulse response of the bike used to measure road data is convoluted with the road acceleration in order to obtain the required actuator signal. The reproduction capacity of the simulator is evaluated by comparing the frequency content as well as the time statistical parameters of the acceleration signal measurement with road to the acceleration obtained on the simulator. On a granular road with a broadband excitation spectrum, the vertical excitation obtained with the simulator adequately mimics the measured road acceleration. This technique can be used to compare vibration transmission characteristics among different road bikes., The authors gratefully acknowledge financial support from the National Science and Engineering Council of Canada (NSERC) and the participation of Cervélo and Vroomen-White Design.

Previous single country research has raised concerns that: (1) the DSM-IV diagnosis of alcohol abuse (AA) is met primarily through the hazardous use criterion related to drinking and driving and (2) that the hazardous use and social consequences AA criteria primarily reflect varying socioeconomic and cultural factors rather than psychiatric disorder.Using representative cross-national data from the 21 countries in the World Mental Health surveys, adults meeting DSM-IV lifetime criteria for AA but not dependence from 10 developed (n=46,071) and 11 developing (n=49,761) countries were assessed as meeting AA with the hazardous use or the social consequences criteria.Between 29.3% (developed) and 16.2% (developing) of respondents with AA met only the hazardous use criterion. AA cases with and without hazardous use were similar in age-of-onset, course, predictors, and psychopathological consequences in both developed and developing countries.Despite some associations of the AA criteria with socioeconomic factors, the hazardous use and social consequences criteria were significantly associated with psychiatric predictors and sequelae. The findings indicate that these criteria reflect psychiatric disorder and are appropriate for inclusion as DSM-5 Alcohol Use Disorder criteria.These findings support a psychiatric rather than a sociocultural view of the hazardous use and social consequences symptoms and provide evidence that they are appropriate diagnostic criteria cross-nationally with utility in a wide range of socioeconomic environments. This suggests consideration for their adoption by ICD-11. Further research is needed on the implications of these results for prevention and treatment.

Recently it has been proposed that there are two types of SN Ia progenitors -- short-lived and long-lived. On the basis of this idea, we develope a theory of a unified mechanism for the formation of the bimodal radial distribution of iron and oxygen in the Galactic disc. The underlying cause for the formation of the fine structure of the radial abundance pattern is the influence of spiral arms, specifically, the combined effect of the corotation resonance and turbulent diffusion. From our modelling we conclude that to explain the bimodal radial distributions simultaneously for oxygen and iron and to obtain approximately equal total iron output from different types of supernovae, the mean ejected iron mass per supernova event should be the same as quoted in literature if maximum mass of stars, that eject heavy elements, is $50 M_{\odot}$. For the upper mass limit of $70 M_{\odot}$ the production of iron by a supernova II explosion should be increased by about 1.5 times., Comment: 7 pages, 6 figures, MNRAS submitted

A chemical evolution model for the bimodal-like abundance distribution in the external galaxy M51 recently derived on the basis of HST data for more than a half million red supergiants is developed. It is shown that, like in our Galaxy, formation of fine structure of the radial abundance pattern -- a rather steep gradient in the internal part of the disc and a plateau in the middle part -- is due to the influence of the spiral arms, the bend in the slope of the distribution being arose near the corotation resonance. Our model strongly suggests that M51 is surrounded by overabundant gas infalling onto its disc., Comment: 12 pages, 7 figures, submitted to MNRAS

Teleseismic receiver functions (RF) allow us to image the spatial variation of the crust-mantle boundary (Moho) along a tight array spanning from south of the Himalayas to the centre of the Tibetan Plateau. This approach is cross-tested with wide-angle reflection imaging (WARR). Highlighted by each of the two independent methods, a complex architecture of the Moho with dipping and overlapping segments indicating lithospheric imbrication, is confirmed. The joint use of the two methods reveals an increase of the average crustal P-to-S-wave-velocity ratio from south to the centre of the Lhasa block. This may be due to lowered S-wave velocity confined in specific layers, that may be interpreted as partial melt. This accounts for half of the relative increase in the delay of direct teleseismic S-wave arrivals with respect to P-wave arrivals from south to north, suggesting a similar anomaly in the shallower mantle.

We present proper motion measurements of pre-main sequence (PMS) stars associated with major star-forming regions of the southern hemisphere (Chamaeleon, Lupus, Upper Scorpius - Ophiuchus, Corona Australis), situated in the galactic longitude range l = 290\degr to l = 360\degr. A list of PMS stars as complete as possible was established based on the Herbig and Bell catalogue and many new catalogues like the PDS survey, the catalogue of Herbig Ae/Be stars by Th\'e et al. (1994), X-rays surveys, etc. The measurements made use of public material (mainly AC2000 and USNO--A2.0 catalogues) as well as scans of SERC-J Schmidt plates with the MAMA measuring machine (Paris) and Valinhos CCD meridian circle observations (Brazil). We derived proper motions for 214 stars, with an accuracy of 5 to 10 mas/yr depending mainly on the difference of epochs between the position sources. The main characteristics of the sample are discussed. We show that systematic motions of groups of stars exist, which are not explained by the reflex solar motion., Comment: 14 pages, LaTeX, 12 PostScript figures, 6 tables; figures 3, 6 and 7 replaced, tables 3 and 4 updated. Accepted for publication in A&A