Neotethys closure history of Anatolia: insights from 40Ar–39Ar geochronology and P–T estimation in high pressure metasedimentary rocks

The multiple high-pressure (HP), low-temperature (LT) metamorphic units of Western and Central Anatolia offer a great opportunity to investigate the subduction- and continental accretion-related evolution of the eastern limb of the long-lived Aegean subduction system. Recent reports of the HP–LT index mineral Fe-Mg-carpholite in three metasedimentary units of the Gondwana-derived Anatolide–Tauride continental block (namely the Afyon Zone, the Ören Unit and the southern Menderes Massif) suggest a more complicated scenario than the single-continental accretion model generally put forward in previous studies. This study presents the first isotopic dates (white mica 40Ar–39Ar geochronology), and where possible are combined with P–T estimates (chlorite thermometry, phengite barometry, multi-equilibrium thermobarometry), on carpholite-bearing rocks from these three HP–LT metasedimentary units. It is shown that, in the Afyon Zone, carpholite-bearing assemblages were retrogressed through greenschist-facies conditions at c. 67–62 Ma. Early retrograde stages in the Ören Unit are dated to 63–59 Ma. In the Kurudere–Nebiler Unit (HP Mesozoic cover of the southern Menderes Massif), HP retrograde stages are dated to c. 45 Ma, and post-collisional cooling to c. 26 Ma. These new results support that the Ören Unit represents the westernmost continuation of the Afyon Zone, whereas the Kurudere–Nebiler Unit correlates with the Cycladic Blueschist Unit of the Aegean Domain. In Western Anatolia, three successive HP–LT metamorphic belts thus formed: the northernmost Tavşanlı Zone (c. 88–82 Ma), the Ören–Afyon Zone (between 70 and 65 Ma), and the Kurudere–Nebiler Unit (c. 52–45 Ma). The southward younging trend of the HP–LT metamorphism from the upper and internal to the deeper and more external structural units, as in the Aegean Domain, points to the persistence of subduction in Western Anatolia between 93–90 and c. 35 Ma. After the accretion of the Menderes–Tauride terrane, in Eocene times, subduction stopped, leading to continental collision and associated Barrovian-type metamorphism. Because, by contrast, the Aegean subduction did remain active due to slab roll-back and trench migration, the eastern limb (below Southwestern Anatolia) of the Hellenic slab was dramatically curved and consequently teared. It therefore is suggested that the possibility for subduction to continue after the accretion of buoyant (e.g. continental) terranes probably depends much on palaeogeography.

First Clinical Experience With Celt ACD(®) : A Femoral Arterial Puncture Closure Device

Introduction This prospective nonrandomized study compared the safety and efficacy of a novel arterial closure device (ACD) in common femoral artery procedures to that of the FDA submitted historical manual pressure control group, who underwent either a diagnostic angiogram (DA) or a percutaneous coronary intervention (PCI) procedure. Methods and Results A total of 55 patients were enrolled in this study of the novel ACD. Of the 55 patients, 39 were enrolled in the DA group and 16 were enrolled in the PCI group. Six patients were excluded. A device was deployed in 49 patients. Time to hemostasis (TTH), time to ambulation (TTA), device function, and device-related vascular complications were measured. In the device group, the TTH for the combined DA and PCI patients was 32 seconds (0.54 ± 0.93 minutes), significantly lower when compared with 16.0 ± 12.2 minutes (P < 0.0001) for the control group. Overall major vascular complication rate did not differ significantly, device group (1/49) and the historical control group (1/217). TTA in the combined PCI and DA device group was 226.4 ± 231.9 at the German site (site ambulation policy). In the Irish site, the average TTA in the PCI group was 187 minutes (n = 8) and 85 minutes (n = 14) in the DA group. Conclusion The Celt ACD® device is safe, effective, and significantly decreases the TTH compared to manual pressure and has a low vascular complications rate. The device may be effective in early ambulation and discharge of patients postcoronary intervention procedures.

C'est le moment où ressurgissent les rêves

Interview. Pasqualina Perrig-Chiello étudie depuis des années le développement des gens qui se trouvent au milieu de leur vie, entre 40 et 60 ans.

Percutaneous closure of patent foramen ovale in patients with cryptogenic embolism: a network meta-analysis

BACKGROUND Up to 40% of ischaemic strokes are cryptogenic. A strong association between cryptogenic stroke and the prevalence of patent foramen ovale (PFO) suggests paradoxical embolism via PFO as a potential cause. Randomized trials failed to demonstrate superiority of PFO closure over medical therapy. METHODS AND RESULTS Randomized trials comparing percutaneous PFO closure against medical therapy or devices head-to-head published or presented by March 2013 were identified through a systematic search. We performed a network meta-analysis to determine the effectiveness and safety of PFO closure with different devices when compared with medical therapy. We included four randomized trials (2963 patients with 9309 patient-years). Investigated devices were Amplatzer (AMP), STARFlex (STF), and HELEX (HLX). Patients allocated to PFO closure with AMP were less likely to experience a stroke than patients allocated to medical therapy [rate ratio (RR) 0.39; 95% CI: 0.17-0.84]. No significant differences were found for STF (RR 1.01; 95% CI: 0.44-2.41), and HLX (RR, 0.71; 95% CI: 0.17-2.78) when compared with medical therapy. The probability to be best in preventing strokes was 77.1% for AMP, 20.9% for HLX, 1.7% for STF, and 0.4% for medical therapy. No significant differences were found for transient ischaemic attack and death. The risk of new-onset atrial fibrillation was more pronounced for STF (RR 7.67; 95% CI: 3.25-19.63), than AMP (RR 2.14; 95% CI: 1.00-4.62) and HLX (RR 1.33; 95%-CI 0.33-4.50), when compared with medical therapy. CONCLUSIONS The effectiveness of PFO closure depends on the device used. PFO closure with AMP appears superior to medical therapy in preventing strokes in patients with cryptogenic embolism.