Commissioning of the novel Continuous Angle Multi-energy Analysis spectrometer at the Paul Scherrer Institut.

We report on the commissioning results of the cold neutron multiplexing secondary spectrometer CAMEA (Continuous Angle Multi-Energy Analysis) at the Swiss Spallation Neutron Source at the Paul Scherrer Institut, Switzerland. CAMEA is optimized for efficient data acquisition of scattered neutrons in the horizontal scattering plane, allowing for detailed and rapid mapping of low-energy excitations under extreme sample environment conditions.

New insights into correlated materials in the time domain-combining far-infrared excitation with x-ray probes at cryogenic temperatures.

Modern techniques for the investigation of correlated materials in the time domain combine selective excitation in the THz frequency range with selective probing of coupled structural, electronic and magnetic degrees of freedom using x-ray scattering techniques. Cryogenic sample temperatures are commonly required to prevent thermal occupation of the low energy modes and to access relevant material ground states. Here, we present a chamber optimized for high-field THz excitation and (resonant) x-ray diffraction at sample temperatures between 5 and 500 K. Directly connected to the beamline vacuum and featuring both a Beryllium window and an in-vacuum detector, the chamber covers the full (2-12.7) keV energy range of the femtosecond x-ray pulses available at the Bernina endstation of the SwissFEL free electron laser. Successful commissioning experiments made use of the energy tunability to selectively track the dynamics of the structural, magnetic and orbital order of Ca2RuO4and Tb2Ti2O7at the Ru (2.96 keV) and Tb (7.55 keV)L-edges, respectively. THz field amplitudes up to 1.12 MV cm-1peak field were demonstrated and used to excite the samples at temperatures as low as 5 K.

Z3-vestigial nematic order due to superconducting fluctuations in the doped topological insulators NbxBi2Se3 and CuxBi2Se3.

A state of matter with a multi-component order parameter can give rise to vestigial order. In the vestigial phase, the primary order is only partially melted, leaving a remaining symmetry breaking behind, an effect driven by strong classical or quantum fluctuations. Vestigial states due to primary spin and charge-density-wave order have been discussed in iron-based and cuprate materials. Here we present the observation of a partially melted superconductivity in which pairing fluctuations condense at a separate phase transition and form a nematic state with broken Z3, i.e., three-state Potts-model symmetry. Thermal expansion, specific heat and magnetization measurements of the doped topological insulators NbxBi2Se3 and CuxBi2Se3 reveal that this symmetry breaking occurs at [Formula: see text] above [Formula: see text], along with an onset of superconducting fluctuations. Thus, before Cooper pairs establish long-range coherence at Tc, they fluctuate in a way that breaks the rotational invariance at Tnem and induces a crystalline distortion.

CAMEA--A novel multiplexing analyzer for neutron spectroscopy.

The analyzer detector system continuous angle multiple energy analysis will be installed on the cold-neutron triple-axis spectrometer RITA-2 at SINQ, PSI. CAMEA is optimized for efficiency in the horizontal scattering plane enabling rapid and detailed mapping of excitations. As a novelty the design employs a series of several sequential upward scattering analyzer arcs. Each arc is set to a different, fixed, final energy and scatters neutrons towards position sensitive detectors. Thus, neutrons with different final energies are recorded simultaneously over a large angular range. In a single data-acquisition many entire constant-energy lines in the horizontal scattering plane are recorded for a quasi-continuous angular coverage of about 60°. With a large combined coverage in energy and momentum, this will result in a very efficient spectrometer, which will be particularly suited for parametric studies under extreme conditions with restrictive sample environments (high field magnets or pressure cells) and for small samples of novel materials. In this paper we outline the concept and the specifications of the instrument currently under construction.

Tuning magnetic spirals beyond room temperature with chemical disorder.

In the past years, magnetism-driven ferroelectricity and gigantic magnetoelectric effects have been reported for a number of frustrated magnets featuring ordered spiral magnetic phases. Such materials are of high-current interest due to their potential for spintronics and low-power magnetoelectric devices. However, their low-magnetic ordering temperatures (typically <100 K) greatly restrict their fields of application. Here we demonstrate that the onset temperature of the spiral phase in the perovskite YBaCuFeO5 can be increased by more than 150 K through a controlled manipulation of the Fe/Cu chemical disorder. Moreover, we show that this novel mechanism can stabilize the magnetic spiral state of YBaCuFeO5 above the symbolic value of 25 °C at zero magnetic field. Our findings demonstrate that the properties of magnetic spirals, including its wavelength and stability range, can be engineered through the control of chemical disorder, offering a great potential for the design of materials with magnetoelectric properties beyond room temperature.

The effect of leukocyte reduction filters on inflammatory mediator release during coronary artery bypass grafting.

BACKGROUND: Extracorporeal circulation used during coronary artery bypass grafting triggers systemic inflammatory response with neutrophil activation which adversely affects ischaemic/reperfused myocardium. One method of myocardial protection during cardiac surgery is the use of blood cardioplegia. Its protective effect is related to cardiac cooling and metabolism reduction, oxygen supply from erythrocytes, and reactive oxygen species scavenging. However, blood cardioplegia is also associated with myocardial damage induced by undesirable morphotic blood elements. AIM: To evaluate the effect of the use of leukocyte reduction filters on the activity of polymorphonuclear neutrophils (PMN) in patients undergoing surgical myocardial revascularisation. PMN activity was evaluated based on measurements of plasma activity of granulocyte enzymes, lysozyme and beta-glucuronidase. METHODS: We studied 40 patients who underwent myocardial revascularisation using extracorporeal circulation. Patients were randomly assigned to two equal groups: in Group I, blood cardioplegia was administered using leukocyte reduction filters, and in Group II, leukocyte reduction filters were not used for blood cardioplegia. Measurements were performed in plasma of arterial and coronary sinus blood samples collected before aortic clamping, immediately after unclamping, and after 25 min of reperfusion. In addition, blood cardioplegic solution samples were collected in Group I from the lines proximal and distal to the filter during first and last administration. Plasma levels of lysozyme and beta-glucuronidase were determined using previously described methods. RESULTS: We found a significant decrease in PMN count in filtered blood cardioplegic solution during its first administration (0.27 ± 0.07 G/L) compared to samples collected before filter passage (1.73 ± 0.049 G/L). Also during last administration, PMN count in filtered blood cardioplegic solution was decreased compared to samples collected before filter passage (0.66 ± 0.35 G/L vs. 3.64 ± 1.14 G/L, respectively). Significantly lower (p < 0.02) plasma beta-glucuronidase levels were found in arterial blood samples in Group I compared to Group II (5.59 ± 1.63 µg/mL immediately after aortic unclamping and 6.59 ± 1.98 µg/mL after 25 min of reperfusion in Group I vs. 10.19 ± 2.66 and 12.83 ± 1.88 µg/mL, respectively, in Group II). Beta-glucuronidase levels in coronary sinus blood samples collected after aortic unclamping and at the end of reperfusion were significantly higher in Group II compared to Group I (p < 0.04). In Group I, plasma lysozyme levels in arterial and venous blood samples did not show significant changes during the surgery. In contrast, plasma lysozyme level in coronary sinus blood samples at the end of reperfusion in Group II was significantly higher compared to that in pre-clamping samples (p < 0.014). CONCLUSIONS: With the use of leukocyte reduction filters, we found significantly lower beta-glucuronidase levels in arterial and coronary sinus blood samples. These findings seem to confirm reduced PMN activation and/or reduced myocardial infiltration by activated PMN. Plasma levels of lysozyme, a characteristic product of PMN degranulation, did not show significant differences between the study groups.

[A large asymptomatic pericardial cyst in the apical region]. / Duza bezobjawowa torbiel osierdzia w okolicy koniuszka serca.

We presented a case of the large asymptomatic pericardial cyst localised near cardiac apex, filled with fluid of water- -equivalent density. The cyst was detected accidentally during transthoracic echocardiography and confirmed by 64-slice multi-detector computed tomography. Repeated transthoracic echocardiography was recommened.

Mitral valve repair in a patient with previous percutaneous annuloplasty with a CARILLON device.

A 67-year-old female patient was referred to our clinic for coronary artery bypass graft and severe mitral regurgitation (MR) treatment. The patient had a history of coronary disease and MR treated in 2007 with a CARILLON device. Left mammary and saphenous vein were used to graft the diseased coronaries. MR was corrected with a saddle ring; however, we had some difficulties anchoring ring sutures to the mitral annulus caused by the protruding CARILLON. The ring was finally stitched, and the patient was weaned from bypass. A transoesophageal echo showed a competent valve. The patient was transferred to the intensive care unit on moderate catecholamines.