Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Three-Dimensional printing for hybrid closure of complex muscular ventricular septal defects

The identification and surgical closure of apical complex muscular ventricular septal defects (CMVSD) remains a difficult problem because of their location in the ventricular septum distal to the moderating band

Successful conservation of the endangered forest lichen Lobaria pulmonaria requires knowledge of fine-scale population structure

We explored the fine scale patterns of populations of the lichen Lobaria pulmonaria in its most suitable habitats across Italy, accounting for different developmental stages as well as for a set of biotic and abiotic descriptors. Results revealed that the tree-level probability of occurrence of the species is influenced by an interplay between the forest habitat type and some abiotic and biotic factors whose interactive effects vary during the life cycle of the lichen. Moreover, results indicated that oak (Quercus sp.pl.)-dominated forests provide more suitable habitat conditions for L. pulmonaria than montane mixed forests, with chestnut (Castanea sativa) forests in an intermediate position. The effect of habitat was significant only for adult thalli while the early life stages of the lichen were habitat-independent and were strictly associated with tree-level factors. A positive relationship between bryophyte cover and juvenile thalli was found

Feasibility of percutaneous coronary intervention before mitral NeoChord implantation: Single-center early results

Micro-invasive cardiac surgery identifies procedures performed off-pump, on beating heart. Aim of this single-center retrospective study was to assess early outcomes of a totally micro-invasive strategy (percutaneous coronary intervention-PCI-followed by transapical off-pump NeoChord mitral repair) in patients with concomitant coronary artery disease (CAD) and degenerative mitral regurgitation (MR)

Strabismus and diplopia in a patient with acute myeloid leukemia

Background: Central nervous system (CNS) involvement is a sporadic presenting finding in patients with acute myeloid leukemia (AML) both at diagnosis and at relapse. Moreover patients with CNS localization are often asymptomatic, while sometimes show meningeal signs and symptoms or, extremely rarely, signs of cranial nerve impairment. Case Report: Here we report on a patient with refractory AML who suddenly developed strabismus and diplopia. Both neurological and ophtalmologic examinations were suggestive of a bilateral VI cranial nerve palsy. Noteworthy, both a cranial CT and MRI were substantially normal, while a rachicentesis was performed and cerebrospinal fluid examination was clearly suggestive of a meningeal involvement by AML. Conclusions: This is to our knowledge the first reported case in which the clinical picture of meningeal localization in an AML patient was dominated by an isolated abducens cranial nerve impairment. Moreover it highlights as unexplained strabismus and diplopia can be considered as a potential sign of CNS involvement, even if conventional imaging is negative

Transapical off-pump echo-guided mitral valve repair with neochordae implantation mid-term outcomes

The NeoChord echo-guided transapical beating heart repair is a promising early-stage minimally invasive surgical procedure for degenerative mitral valve (MV) regurgitation (DMR) correction. The technique has been improved since its inception following procedure standardization, patient selection optimization, and learning curve stabilization. We hereby present the mid-term clinical results through three years of our large single center experience