5 research outputs found
Has COVID-19 Delayed the Diagnosis and Worsened the Presentation of Type 1 Diabetes in Children?
Objective: To evaluate whether the diagnosis of pediatric type 1 diabetes or its acute complications changed during the early phase of the coronavirus disease 2019 (COVID-19) pandemic in Italy.
Research design and methods: This was a cross-sectional, Web-based survey of all Italian pediatric diabetes centers to collect diabetes, diabetic ketoacidosis (DKA), and COVID-19 data in patients presenting with new-onset or established type 1 diabetes between 20 February and 14 April in 2019 and 2020.
Results: Fifty-three of 68 centers (77.9%) responded. There was a 23% reduction in new diabetes cases in 2020 compared with 2019. Among those newly diagnosed patient who presented in a state of DKA, the proportion with severe DKA was 44.3% in 2020 vs. 36.1% in 2019 (P = 0.03). There were no differences in acute complications. Eight patients with asymptomatic or mild COVID-19 had laboratory-confirmed severe acute respiratory syndrome coronavirus 2.
Conclusions: The COVID-19 pandemic might have altered diabetes presentation and DKA severity. Preparing for any "second wave" requires strategies to educate and reassure parents about timely emergency department attendance for non-COVID-19 symptoms
Solidification and Turbulence (Non-laminar) during Magma Ascent: Insights from 2D and 3D Analyses of Bubbles and Minerals in an Etnean Dyke
Solidification, emplacement and fluid dynamics of a sub-volcanic rock at Mt Etna have been investigated
through two-dimensional (2D) and three-dimensional (3D) textural analyses of the hosted
bubbles and minerals. This rock is a 4 3m thick aphyric dyke (DK) that solidified at a depth of
100–300 m, below the pristine surface level. Seven samples from the dyke rim (DK1) to core (DK7)
have been analysed in two dimensions by using a high-resolution scanner, a transmission optical
microscope and scanning electron microscopy imaging with back-scattered electrons, and in three
dimensions by microfocus X-ray computed tomography. Field observations and mesoscopic polished
rock surfaces show bubble-rich, -poor and -free patches even in rock pieces of a few cubic
centimetres, with changes in sizes and shapes; even so, their shapes and spatial arrangement can
never be attributed to high degrees of strain. In parallel, the amount of bubbles irregularly varies
from dyke rim to core, whereas plagioclase (plg), clinopyroxene (cpx), titanomagnetite (timt), and
olivine (ol) show only limited variations. The fabric of bubbles retrieved by 3D orientation of their
maximum length (i.e. elongation) is invariably random in space for each DK sample. These bubble
features have been attributed to transitional to turbulent flows; that is, non-laminar regimes
(Reynolds number>1000), predicted for a long time from numerical models and that occurred
before the crystallization of minerals. Water solubility, volume of bubbles, magma density and viscosity
models indicate that, at pressure higher than 10 MPa, 1wt % H2O was dissolved in the original
trachybasaltic magma, which, in turn, was close to its liquidus temperature. As the pressure
decreased at very shallow levels, the magma significantly degassed and volatile exsolution
induced marked crystallization (mostly plg followed by cpx). The viscosity of the system increased,
decelerating and halting the magmatic suspension. The textures and fabrics of bubbles were suddenly
frozen in, despite crystals continuing to grow under the effect of cooling rate variables from
the inner (DK7) to outer (DK1) dyke portions. Fluid-dynamic computations suggest that the DK trachybasaltic
magma ascended with a velocity of few metres per second in a transitional to turbulent
regime, before the growth of minerals.Published1511–15333V. Proprietà dei magmi e dei prodotti vulcaniciJCR Journa
The Skaros effusive sequence at Santorini (Greece): Petrological and geochemical constraints on an interplinian cycle
Santorini volcanic complex (Greece) is the result of a long evolutionary history, marked by the alternation of explosive (Plinian) eruptions and interplinian low explosive/effusive eruptive cycles. Products emitted during the interplinian stages are well exposed along the rim of the calderic structure formed during the major Minoan (3.6 ka) Plinian eruption. We conducted a systematic sampling of the basaltic to dacitic lavas erupted by the interplinian volcanic centre of Skaros, active between 67 and 54 ka. The continuously exposed products of the Skaros lifecycle offer the tremendous opportunity to reconstruct the petrological evolution of the volcanic centre, and in turn to provide new insights on the behaviour of Santorini feeding system during interplinian stages. The combination of whole-rock, mineral chemistry and synchrotron X-ray computed microtomography analyses enabled us to decipher the main physico-chemical parameters of the Skaros plumbing system that drove ascent and differentiation processes of magmas. Results indicate that the main magma ponding zone beneath Skaros centre extended from 12 to 4 km b.s.l., where it underwent frequent refilling by basaltic melts. In the later evolutionary stage of the Skaros system, the basaltic replenishment became less frequent allowing the ultimate differentiation of magma towards dacitic composition. The shallow nature of the magma ponding zone, sited well above the H2O saturation depth, favoured the continuous degassing and inhibited the increase of vapor pressure during differentiation, preventing the onset of explosive eruptions, as in case of the major explosive events at Santorini