Hallmarks of quantum mechanics include superposition and entanglement. In the context of large complex systems, these features should lead to situations as envisaged in the 'Schrödinger's cat' thought experiment (where the cat exists in a superposition of alive and dead states entangled with a radioactive nucleus). Such situations are not observed in nature. This may be simply due to our inability to sufficiently isolate the system of interest from the surrounding environment-a technical limitation. Another possibility is some as-yet-undiscovered mechanism that prevents the formation of macroscopic entangled states. Such a limitation might depend on the number of elementary constituents in the system or on the types of degrees of freedom that are entangled. Tests of the latter possibility have been made with photons, atoms and condensed matter devices. One system ubiquitous to nature where entanglement has not been previously demonstrated consists of distinct mechanical oscillators. Here we demonstrate deterministic entanglement of separated mechanical oscillators, consisting of the vibrational states of two pairs of atomic ions held in different locations. We also demonstrate entanglement of the internal states of an atomic ion with a distant mechanical oscillator. These results show quantum entanglement in a degree of freedom that pervades the classical world. Such experiments may lead to the generation of entangled states of larger-scale mechanical oscillators, and offer possibilities for testing non-locality with mesoscopic systems. In addition, the control developed here is an important ingredient for scaling-up quantum information processing with trapped atomic ions.

AimsIn patients with systolic heart failure (SHF) a high prevalence of sleep-disordered breathing (SDB) has been documented. The purpose of this study was to investigate the prevalence and type of SDB in patients with heart failure with normal left ventricular ejection fraction (HFNEF). Methods and resultsTwo hundred and forty-four consecutive patients (87 women, aged 65.3 + 1.4 years) with HFNEF underwent capillary blood gas analysis, measurement of NT-proBNP concentrations, echocardiography, cardiopulmonary exercise testing (CPX), cardiorespiratory polygraphy, and simultaneous right and left heart catheterization. Sleep-disordered breathing was defined as an apnoea-hypopnoea-index (AHI) 5/h. Sleep-disordered breathing was documented in 69.3% of all patients, 97 patients (39.8%) presented with OSA and 72 patients (29.5%) with CSA. With an increasing impairment of diastolic function the proportion of SDB, and CSA in particular, increased. Patients with SDB performed worse on CPX and six-minute walk test. Partial pressure of CO 2 was lower in CSA, whereas AHI, left atrial diameter, NT-proBNP, LVEDP, PAP, and PCWP were higher. ConclusionThere is a high prevalence of SDB in HFNEF. In parallel to SHF, CSA patients in particular are characterized by a more impaired cardiopulmonary function. Whether SDB is of prognostic relevance in HFNEF needs to be determined.--

In patients with CHF, CSA and OSA are independently associated with an increased risk for ventricular arrhythmias and appropriate cardioverter-defibrillator therapies.