ABSTRACT
The energetic convenience of electrolytic water splitting is limited by thermodynamics. Consequently, significant levels of hydrogen production can only be obtained with an electrical energy consumption exceeding 45 kWh kg(-1)H2. Electrochemical reforming allows the overcoming of such thermodynamic limitations by replacing oxygen evolution with the oxidation of biomass-derived alcohols. Here we show that the use of an original anode material consisting of palladium nanoparticles deposited on to a three-dimensional architecture of titania nanotubes allows electrical energy savings up to 26.5 kWh kg(-1)H2 as compared with proton electrolyte membrane water electrolysis. A net energy analysis shows that for bio-ethanol with energy return of the invested energy larger than 5.1 (for example, cellulose), the electrochemical reforming energy balance is advantageous over proton electrolyte membrane water electrolysis.
ABSTRACT
AIM: The aim of this paper was to evaluate how many patients with syncope should be hospitalized according to the 2001 European Society of Cardiology (ESC) Guidelines on the management of syncope. METHODS: Starting from August 2002 we prompted a Syncope Unit (SU), as a multi-disciplinary functional structure including the Emergency Department. One of the main objectives of the SU was the implementation of the 2001 ESC Guidelines on Syncope and of the relevant criteria for hospitalization. All the clinical data concerning the patients presenting with syncope were prospectively collected and stored in a dedicated database. RESULTS: Between September 1, 2002 and April 30, 2003, 402 patients were observed for a syncope. Out of these, 19 had a cardiogenic syncope, 3 focal neurologic disorders, 25 a severe trauma, 4 severe orthostatic hypotension and 5 carotid syncope. Therefore, 56 patients out of 402 were found to have indication to therapeutical hospitalization. Among the remaining 346 patients, 83 patients were found to have a structural heart disease and/or an abnormal ECG, 1 had syncope during exercise, 3 presented a familial history of sudden death. Thirty-three were found to have severe comorbidities and further 14 had occasional indication to hospitalization. Thus, 190 out of the 402 patients with syncope (47.3%) presented at least 1 criterion for hospitalization according to the ESC Guidelines. CONCLUSION: The implementation of the ESC Guidelines on Syncope is technically feasible. Nevertheless, even when the Guidelines are strictly observed, a high percentage of patients with syncope has still to be hospitalized. Our data suggest that new criteria should be established for a safe Emergency Department discharge of the patients with syncope, particularly of those with structural heart disease or abnormal ECG.
Subject(s)
Cardiology , Hospitalization , Practice Guidelines as Topic , Societies, Medical , Syncope , Death, Sudden/etiology , Electrocardiography , Europe , Exercise , Heart Diseases/complications , Heart Diseases/diagnosis , Humans , Hypotension, Orthostatic/complications , Middle Aged , Nervous System Diseases/complications , Prospective Studies , Recurrence , Syncope/diagnosis , Syncope/etiology , Syncope/therapy , Wounds and Injuries/complicationsABSTRACT
This study was carried out to assess the sensitivity of single photon bone absorptiometry (SPBA) as an early screening tool for osteoporosis and select the optimum site for measurement. We measured bone mineral density (BMD) at the distal tenth of both radius and ulna (D-BMD) and at the ultradistal radius, a site distal to the point at which the radius and ulna are 8 mm apart (UD-BMD). Our study group consisted of 107 healthy women aged 25-60 years (mean +/- SD: 45.8 +/- 10.0), subdivided according to age into 3 groups: Group 1: 25-40 years, Group 2: 41-50 years, Group 3: 51-60 years. When comparison was made to Group 1, D-BMD was found significantly reduced only in Group 3 (p < 0.0001), while UD-BMD was found reduced in both Groups 2 (p < 0.02) and 3 (p < 0.0001). The percent reduction of BMD in Groups 2 and 3 with respect to Group 1 was significantly greater at the ultradistal site than at the distal tenth of the radius and ulna (p < 0.0001 versus D-BMD). Despite limits inherent in the cross-sectional study design, our results suggest that forearm SPBA indicates post-menopausal bone loss irrespective of scanning site, but detects pre-menopausal loss sensitively only at the ultradistal site. Ultradistal measurement would therefore seem suitable for early screening for osteoporosis as an alternative or in addition to the generally used more proximal site.
