The decoherence criterion

The decoherence mechanism signals the limits beyond which the system dynamics approaches the classical behavior. We show that in some cases decoherence may also signal the limits beyond which the system dynamics has to be described by quantum field theory, rather than by quantum mechanics.Comment: revised paper, in print on Mod. Phys. Lett.

Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81 years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16-2.61) and patients with dementia (HR 1.75, 95% CI 1.06-2.90) had a higher risk of death at one year. The Kaplan-Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population

Determination of 13C/12C Carbon Isotope Ratio

Isotopomers 12CO2 and 13CO2 absorbed into polystyrene films provide narrow, sharp, and well-resolved IR absorption bands for the î3 antisymmetric stretching mode. This is exploited to set up an inexpensive FT-IR-based method for the measurement of the carbon isotope ratio. Accuracy of 2.5‰ ä13C units is readily achieved already at a low resolution of 2 cm-1

Effect of chronic administration of tacrolimus and cyclosporine on human gastrointestinal permeability.

The antirejection drug tacrolimus (FK506) has been reported to impair intestinal permeability in an early stage after orthotopic liver transplantation (OLT), and cyclosporine (CsA) has shown a similar effect in animals. We studied the chronic effect of FK506 and CsA on gastroduodenal and intestinal permeability and on blood endotoxin levels in patients 2 to 3 years after OLT. Thirty-two OLT patients (22 men and 10 women; mean age, 44.8 +/- 7.1) who had received CsA (n = 19) or FK506 (n = 13) and 10 healthy volunteers (6 male and 4 female, mean age 41.7 +/- 5.4) were assessed for gastroduodenal permeability by recovery in urine of sucrose after oral administration and for intestinal permeability by recovery in urine after oral loads of rhamnose and lactulose, which evaluate the intracellular and paracellular routes, respectively. In all subjects, plasma levels of endotoxins also were assessed. Gastroduodenal permeability was similar in patients and controls (0.03 +/- 0.003 versus 0.04 +/- 0.01%, P = NS). In regard to intestinal permeability, passage through the intracellular route was significantly reduced in OLT patients compared with controls (1.13 +/- 0.06 versus 2.74 +/- 0.17%, P <.01), but paracellular permeability was unchanged (0.14 +/- 0.007 versus 0.13 +/- 0.01%, P = NS). Serum endotoxin levels were similar in all subjects. We conclude that chronic administration of FK506 or CsA induces a clinically irrelevant, selective dysfunction of monosaccharide absorption, but does not affect gastroduodenal or intestinal permeabilit