Syn-exhumation coupling of oceanic and continental units along the western edge of the alpine corsica: A review

The Alpine Corsica represents a segment of the Alpine collisional belt. In its western edge, it is characterized by the close association of continental units deformed under high-pressure metamorphic conditions (Lower Units) and oceanic units showing a metamorphism ranging from high-pressure (Schistes Lus-trés Complex) to very low-grade conditions (Upper Units). This paper provides a complete review of the relationships between the continental and oceanic units in selected five areas where the stratigraphic features, deformation history, metamorphic P-T path and tectonic setting are available for each unit. The collected data indicate that the oceanic units occur not only at the top of the continental ones, as generally proposed in the literature, but also intercalated within them. Such relationships were achieved at shallow structural level during the late stage of exhumation, when the continental units were tectonically coupled with the oceanic units which were dragged as slices from the orogenic wedge. The coupling probably occurred immediately before the transition from syn-to post-orogenic geodynamic regime that affected the whole Alpine-Apennine collisional system in the early Oligocene. After the coupling, the stack of oceanic and continental units experienced a further exhumation-related deformation before their final exposure at the surface

Evidences for a Late Cretaceous continental arc in the Central Pontides: new insights on alternative geodynamic reconstructions for the Neotethys in Northern Turkey

The Intra-Pontide Suture Zone (IPSZ) is the less known one among the suture zones present in Turkey. The IPSZ is well exposed along the Daday-Arac-Kursunlu and Tosya – Emirköy geotraverses where several tectonic units can be recognized. Most of these units are characterized by the occurrence of basic rocks reflecting distinct tectonic origins and geochemical signatures. The study of the basic rocks emerges as an important tool for the geodynamic reconstruction as it can reveal the occurrence of of different types of oceanic basins, the development of a magmatic arc or the presence of rifting-related magmatism. The study of the geotraverses indicates that the imbricate stack of the IPSZ consists of four distinct tectonic units whose successions bear basic rocks: the Aylı Dağ ophiolite Unit, the Arkot Dağ Mèlange and two metamorphic units, referred to as Daday and Devrekani Units. This imbricate stack is probably the result of several episodes of out-of-sequence thrusts that affected the whole IPSZ. The Aylı Dağ Unit includes an about 5 km-thick ophiolite sequence topped by the middle Bathonian to early Callovian radiolarian cherts. In addition, a metamorphic sole is present at the base of the serpentinized peridotites. The geochemical evaluation of pillow-basalts and dykes highlights subduction-related characteristics, similar to IAT- and BABB-type lavas generated above intra-oceanic subduction systems. The Arkot Dağ Mèlange consists of an assemblage of slide-blocks, with different size and lithology, enclosed in a Late Santonian sedimentary matrix. The slide-blocks also include ophiolitic lithologies, mainly represented by basalts, but gabbros and peridotites are also found. The slide-blocks of basalts display affinites to IAT- and BABB-type magmas, signifying the involvement of subduction component, whereas no MORB-like basalt have been found. The Daday unit is characterized by metasedimentary and metabasic rocks deformed under blueschist to subgreenschist metamorphic facies conditions. The metasedimentary rocks include mica-bearing schists, fine-grained marbles and black quartzites. The metabasic lithologies, on the other hand, comprise actinolite-bearing schists and Naamphibole- bearing varieties possibly derived from basaltic and gabbroic protoliths. The metabasic rocks have a wide range of chemical compositions, displaying N-MORB-, E-MORB-, OIB- BABB- and IAT-type signatures. The Devrekani Unit is represented by an assemblage of amphibolites, marbles and micaschists showing a metamorphic climax developed under upper amphibolite facies in the Late Jurassic time. The amphibolites display EMORB-, OIB- BABB- and IAT-type signatures. The geochemical signature of the studied basic rocks provide the evidence that all the basic rocks from the tectonic units of IPSZ are derived by a supra-subduction zone. This finding can provide new nsights for the recostruction of the sgeodynamic history of the Intra-Pontide domain

The Intra-Pontide ophiolites in Northern Turkey revisited: From birth to death of a Neotethyan oceanic domain

The Anatolian peninsula is a key location to study the central portion of the Neotethys Ocean(s) and to understand how its western and eastern branches were connected. One of the lesser known branches of the Mesozoic ocean(s) is preserved in the northern ophiolite suture zone exposed in Turkey, namely, the Intra-Pontide suture zone. It is located between the Sakarya terrane and the Eurasian margin (i.e., Istanbul-Zonguldak terrane) and consists of several metamorphic and non-metamorphic units containing ophiolites produced in supra-subduction settings from the Late Triassic to the Early Cretaceous. Ophiolites preserved in the metamorphic units recorded pervasive deformations and peak metamorphic conditions ranging from blueschist to eclogite facies. In the non-metamorphic units, the complete oceanic crust sequence is preserved in tectonic units or as olistoliths in sedimentary mélanges. Geochemical, structural, metamorphic and geochronological investigations performed on ophiolite-bearing units allowed the formulation of a new geodynamic model of the entire "life" of the Intra-Pontide oceanic basin(s). The reconstruction starts with the opening of the Intra-Pontide oceanic basins during the Late Triassic between the Sakarya and Istanbul-Zonguldak continental microplates and ends with its closure caused by two different subductions events that occurred during the upper Early Jurassic and Middle Jurassic. The continental collision between the Sakarya continental microplate and the Eurasian margin developed from the upper Early Cretaceous to the Palaeocene. The presented reconstruction is an alternative model to explain the complex and articulate geodynamic evolution that characterizes the southern margin of Eurasia during the Mesozoic era. Keywords: Intra-Pontide suture zone, Central Pontides, Northern Turkey, Ophiolites, Neotethys Ocean, Geodynamic

Persistent pulmonary congestion before discharge predicts rehospitalization in heart failure: a lung ultrasound study

BACKGROUND: B-lines evaluated by lung ultrasound (LUS) are the sonographic sign of pulmonary congestion, a major predictor of morbidity and mortality in patients with heart failure (HF). Our aim was to assess the prognostic value of B-lines at discharge to predict rehospitalization at 6 months in patients with acute HF (AHF). METHODS: A prospective cohort of 100 patients admitted to a Cardiology Department for dyspnea and/or clinical suspicion of AHF were enrolled (mean age 70 ± 11 years). B-lines were evaluated at admission and before discharge. Subjects were followed-up for 6-months after discharge. RESULTS: Mean B-lines at admission was 48 ± 48 with a statistically significant reduction before discharge (20 ± 23, p 15) (log rank χ(2) 20.5, p 15 before discharge (hazard ratio [HR] 11.74; 95 % confidence interval [CI] 1.30-106.16) was an independent predictor of events at 6 months. CONCLUSIONS: Persistent pulmonary congestion before discharge evaluated by ultrasound strongly predicts rehospitalization for HF at 6-months. Absence or a mild degree of B-lines identify a subgroup at extremely low risk to be readmitted for HF decompensation

Subpopulations of anti-β2glycoprotein I antibodies with different pathogenic potential: fine specificity against the domains of β2glycoprotein I

Objective: Anti-β2glycoprotein I antibodies (a-β2GPI) are a laboratory criterion for the antiphospholipid syndrome (APS) and were demonstrated to be involved in the pathogenesis of APS. However, they can also be detected in asymptomatic subjects. It has been suggested that a-β2GPI against Domain1 (D1) associate with thrombosis, while those recognizing Domain4/5 (D4/5) have been identified in non-thrombotic conditions. We evaluate the specificity of a- β2GPI in different clinical situations. Methods: We studied 39 one-year-old healthy children born to mothers with systemic autoimmune diseases (SAD) (15 (38.4%) were born to mothers who were a-β2GPI positive), 33 children with atopic dermatitis (AD) and 55 patients with APS (50 adults and 5 paediatrics). All subjects were IgG a-β2GPI positive. IgG a-β2GPI were performed by homemade ELISA, while IgG a-β2GPI D1 and D4/5 were tested on research ELISAs containing recombinant β2GPI domains antigens. Results: One-year-old children and AD children displayed preferential reactivity for D4/5; patients with APS recognized preferentially D1. We also found a good correlation between a-β2GPI and D4/5 in one-year-old (r=0.853) and AD children (r=0.879) and between a-β2GPI and D1 in the APS group (r=0.575). No thrombotic events were recorded in both groups of children. Conclusions: A-β2GPI found in non-thrombotic conditions (healthy children born to mothers with SAD and AD children) mostly recognize D4/5, in contrast to the prevalent specificity for D1 in the APS group. The different specificity could at least partially explain the "innocent" profile of a-β2GPI in children

the intra pontide suture zone in the tosya kastamonu area northern turkey

ABSTRACTWe present the first detailed geological map of the tectonic units documented in the easternmost branch of the Intra-Pontide suture (IPS) zone in the Tosya-Kastamonu area (Northern Turkey). The Main Map is at 1:50,000 scale and covers an area of about 350 km2. It derived from 1:25,000 scale classic field mapping and represents a detailed overview of the complexities documented in the IPS zone, a tectonic nappe stack originating from the closure of the Intra-Pontide Oceanic basin and the subsequent collision between the Istanbul-Zonguldak terrane and the Sakarya composite terrane. The map shows the orientations of superposed foliations, fold axes and mineral lineations on the basis of geometric cross-cutting relationships documented within the five tectonic units of the IPS zone and provides information on its present-day architecture resulting from activity of the North Anatolian Fault

Burial and exhumation history of the Daday Unit (Central Pontides, Turkey): implications for the closure of the Intra-Pontide oceanic basin

In northern Turkey, the Intra-Pontide suture zone represents one of the first-order tectonic structures located between the Istanbul-Zonguldak and the Sakarya continental terranes. It consists of an east-west trending assemblage of deformed and variably metamorphosed tectonic units, including sedimentary rocks and ophiolites derived from a NeoTethyan oceanic basin, known as Intra-Pontide oceanic basin. One of these units is represented by the Daday Unit that consists of an assemblage of block-in-matrix derived from a supra-subduction oceanic crust and related deep-sea sedimentary cover of Middle Jurassic age. This setting has been acquired during the Late Jurassic by underplating at 26-38 km of depth associated with blueschist facies metamorphism (D1 phase). The following D2, D3 and D4 phases developed in a time span running from Albian to late Paleocene during the exhumation of the Daday Unit from 26-38 km to uppermost structural levels. The high geothermal gradient detected during the development of the D2 phase seems to be consistent with the exhumation of the Daday Units during a continent-arc collisional setting. The tectonic structures of the Intra-Pontide suture zone, resulting from the previously described tectonic history, are unconformably sealed by the late Paleocene - Eocene deposits. This tectonic setting was intensely reworked by the activity of the North Anatolian Fault Zone, producing the present-day geometrical relationships of the Intra-Pontide suture zone of central Pontides

PEGylation Promotes Hemoglobin Tetramer Dissociation

Hemoglobin conjugated with poly(ethylene glycol) (PEG) acts as an oxygen carrier free in plasma, substituting red blood cells in supplementing oxygen in hypo-oxygenation pathologies. Given the complexity of oxygen delivery controls, subtle structural and functional differences in PEGylated hemoglobins might be associated with distinct physiological responses and, potentially, adverse effects. We have compared hemoglobin PEGylated under anaerobic conditions, called PEG-Hb(deoxy), with hemoglobin PEGylated under aerobic conditions, called PEG-Hb(oxy), a product that mimics Hemospan, produced by Sangart, Inc. SDS PAGE and MALDI-TOF analyses demonstrated that PEG conjugation yields products characterized by a broad distribution of PEG/hemoglobin ratios. The elution profiles in size-exclusion chromatography indicate that both products exhibit a more homogeneous distribution of molecular weight/hydrodynamic volume under deoxy conditions and at higher concentrations. PEG-Hb(oxy) shows high oxygen affinity, low modulation of allosteric effectors, almost no cooperativity, a fast and monophasic CO binding, and a limited dependence of functional properties on concentration, whereas PEG-Hb(deoxy) exhibits oxygen binding curves that significantly depend on protein concentration, and a slow CO binding, similar to native hemoglobin. PEGylated CO-hemoglobins, probed by flash photolysis, exhibited a lower amplitude for the geminate rebinding phase with respect to native hemoglobin and a negligible T state bimolecular CO rebinding phase. These findings are explained by an increased dissociation of PEGylated hemoglobins into dimers and perturbed T and R states with decreased quaternary transition rates. These features are more pronounced for PEG-Hb(oxy) than PEG-Hb(deoxy). The detected heterogeneity might be a source of adverse effects when PEGylated Hbs are used as blood substitutes

Pulmonary arterial hypertension and interstitial lung fibrosis in systemic sclerosis: One-stop shop assessment with cardiac and chest ultrasound

Background: Interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are common complications of systemic sclerosis (SSc). Echocardiography evaluates PAH, and chest sonography detects even mild ILC as ultrasound lung comets (ULC), i.e. multiple comet-tails fanning out from the lung surface and originating from subpleural interlobular septa thickened by fibrosis. Aim: to assess ILD and PAH by integrated cardiac and chest ultrasound in SSc. Materials and methods: We enrolled 30 consecutive SSc patients (age=54?13 years, 23 females) in the Rheumatology Clinic of Pisa University. In all, we assessed Systolic Pulmonary Arterial Pressure (SPAP), from maximal velocity of tricuspid regurgitation flow, and ULC score with chest sonography (summing the number of ULC from each scanning space of anterior and posterior right and left chest, from second to fifth intercostal space). All patients underwent plasma assay for anti-topoisomerase antibodies (anti-Scl70), associated with development of pulmonary fibrosis. Twenty-eight patients also underwent High Resolution Computed Tomography, HRCT (from 0=no fibrosis to 3=honey combing). Results: ULC number - but not SPAP - was correlated to HRCT fibrosis and presence SSc-70 antibodies (see figure). ULC number was similar in localized or diffuse forms (16?20 vs. 21?19, p=ns) and was unrelated to SPAP (r=0.216, p=ns). Conclusions: Cardiac and chest sonography assessment of SPAP and ULC allow a complete, simple, radiation-free characterization of vascular and interstitial lung involvement in SSc - all in one setting and with the same instrument, same transducer and the same sonographer. In particular, ULC number, but not SPAP, is associated with HRCT evidence of lung fibrosis and presence of Scl-70 antibodies