RESUMEN
Octave-spanning, 12.5 fs, (1.9 cycle) pulses with 115 µJ energy in the short-wavelength mid-infrared spectral range (1-2.5 µm) have been generated via phase-mismatched cascaded nonlinear frequency conversion using organic DAST (4-N, N-dimethylamino-4'-N'-methylstilbazolium tosylate) crystal. Such ultrafast cascading effect is ensured by the interaction of a pump pulse with the exceptionally large effective nonlinearity of the DAST crystal and experiencing nonresonant, strongly phase-mismatched, Kerr-like negative nonlinearity.
RESUMEN
We demonstrate for the first time (to our knowledge) characterization of ultrashort IR pulses by self-referenced spectral interferometry. Both sub-55-fs pulses from 1.4 µm to 2 µm and broadband 2.5-cycle pulses at 1.65 µm (13 fs FWHM) are characterized.
RESUMEN
BACKGROUND: The addition of spironolactone, an aldosterone antagonist, to standard therapy can reduce the risk of both morbidity and mortality in patients with severe heart failure. OBJECTIVE: To evaluate the use of spironolactone in class III and IV heart failure patients in four urban teaching hospitals. METHODS: We conducted a concurrent medical record review of 163 patients with documented heart failure admitted to a general medicine service over a 5-week period. Data retrieved included patient demographics, heart failure class, left ventricular ejection fraction, spironolactone contraindications, spironolactone use, dose and frequency, and other heart failure medication use, dose and frequency. All data reflected patients' baseline status. RESULTS: Our patient population was 80% white people, 61% male, with a mean age of 70 years (35-99). A total of 114 had class III or IV heart failure (70%). Angiotensin-converting enzyme inhibitors or appropriate alternative were prescribed in 117 (72%) patients, whereas beta-blockers were used in 121 (74%) patients. Fifty-seven patients met spironolactone ideal candidate criteria. Of these, eight (14%) were appropriately prescribed spironolactone. CONCLUSIONS: Three years after publication of the Randomized Aldactone Evaluation Study, spironolactone is underutilized in the treatment of heart failure. Results of this study indicated that the majority of patients in class III or IV heart failure were not prescribed spironolactone. Improvements in spironolactone prescribing are needed.