Proximity effects induced in graphene by magnetic insulators: first-principles calculations on spin filtering and exchange-splitting gaps.

We report on first-principles calculations of spin-dependent properties in graphene induced by its interaction with a nearby magnetic insulator (europium oxide, EuO). The magnetic proximity effect results in spin polarization of graphene π orbitals by up to 24%, together with a large exchange-splitting band gap of about 36 meV. The position of the Dirac cone is further shown to depend strongly on the graphene-EuO interlayer. These findings point toward the possible engineering of spin gating by the proximity effect at a relatively high temperature, which stands as a hallmark for future all-spin information processing technologies.

Ultimate limit of electron-spin precession upon reflection in ferromagnetic films.

We report the discovery of 180° electron-spin precession in spin-polarized electron-reflection experiments on Fe films on Ag(001), the largest possible precession angle in a single electron reflection. Both experiments as a function of Fe film thickness and ab initio calculations show that the appearance of this ultimate spin precession depends with utmost sensitivity on the relaxation of the Fe surface layers during growth. Similar spin precession is also predicted for other ferromagnetic films.

Proceedings of resources for optimal care of acute care and emergency surgery consensus summit Donegal Ireland.

BACKGROUND: Opportunities to improve emergency surgery outcomes exist through guided better practice and reduced variability. Few attempts have been made to define optimal care in emergency surgery, and few clinically derived key performance indicators (KPIs) have been published. A summit was therefore convened to look at resources for optimal care of emergency surgery. The aim of the Donegal Summit was to set a platform in place to develop guidelines and KPIs in emergency surgery. METHODS: The project had multidisciplinary global involvement in producing consensus statements regarding emergency surgery care in key areas, and to assess feasibility of producing KPIs that could be used to monitor process and outcome of care in the future. RESULTS: Forty-four key opinion leaders in emergency surgery, across 7 disciplines from 17 countries, composed evidence-based position papers on 14 key areas of emergency surgery and 112 KPIs in 20 acute conditions or emergency systems. CONCLUSIONS: The summit was successful in achieving position papers and KPIs in emergency surgery. While position papers were limited by non-graded evidence and non-validated KPIs, the process set a foundation for the future advancement of emergency surgery.

The formation of the smallest fullerene-like carbon cages on metal surfaces.

The nucleation and growth of carbon on catalytically active metal surfaces is one of the most important techniques to produce nanomaterials such as graphene or nanotubes. Here it is shown by in situ electron microscopy that fullerene-like spherical clusters with diameters down to 0.4 nm and thus much smaller than C60 grow in a polymerized state on Co, Fe, or Ru surfaces. The cages appear on the surface of metallic islands in contact with graphene under heating to at least 650 °C and successively cooling to less than 500 °C. The formation of the small cages is explained by the segregation of carbon on a supersaturated metal, driven by kinetics. First principles energy calculations show that the clusters polymerize and can be attached to defects in graphene. Under compression, the polymerized cages appear in a crystalline structure.

Some inflammation-related parameters in patients following normo- and hypothermic cardio-pulmonary bypass.

AIMS: One of the complications of Cardio-Pulmonary Bypass is the Systemic Inflammatory Response Syndrome. Cardio-Pulmonary Bypass can be performed under either normothermic or hypothermic conditions. The aim of this study was to compare some inflammation-related parameters of patients following normothermic and hypothermic bypass. Moreover, attempts were undertaken to detect endotoxin, an inflammatory agent that has been implicated in the Systemic Inflammatory Response Syndrome, in the serum of patients. Levels of serum anti-endotoxin antibodies were estimated since they have been reported to negate the effect of endotoxin in the inflammatory syndrome. METHODS AND RESULTS: Seventeen normothermic and 20 hypothermic cases were studied. Blood specimens were collected pre-, off- and post-bypass. Pertinent clinical and surgical data were collected. Hematological parameters (leukocyte, neutrophil and platelet counts) and liver function tests were determined by standard procedures. Endotoxin was determined by the Limulus Lysate Assay and anti-endotoxin antibodies by an enzyme immunoassay. Complement (C3 and C4) levels were determined by radial immunodiffusion. There were increases in leukocyte and neutrophil, and a decline in platelet numbers in both groups of patients. There was a decline in C3 and C4 levels in both groups of patients. Endotoxin was not detected in sera, and anti-endotoxin antibody levels were similar, in both groups of patients. CONCLUSION: There were no significant differences in most of the altered inflammation-related parameters between the two groups of patients. Some of the findings might be partly due to hemo-dilution. The hydrophobic nature of endotoxin among other factors, might have hindered its detection in serum.

Levantamento de bacteremias em hospital geral: HCPA, 1980-1983 / Survey of bacteremias in a general hospital: HCPA, 1980-1983

As hemoculturas positivas surgidas no HCPA durante um período de 40 meses consecutivos foram estudadas, constatando-se que ocorrem 4,7 hemoculturas positivas por mil pacientes por ano. Esses achados foram avaliados sob ponto de vista bacteriológico, terapêutico e prognóstico