The free-electron laser (FEL) has become an important tool for producing high-intensity photon beams, especially in the infrared. Synchrotron radiation's primary spectral domains are in the ...ultraviolet and X-ray region. FEL's are therefore excellent complimentary facilities to synchrotron radiation sources. While FEL's have seen only limited use in experimentation, recently developed programs at Vanderbilt University in Nashville, TN, are swiftly rectifying this situation. This review paper examines practical experience obtained through pioneering programs using the Vanderbilt FEL, which currently hosts one of the largest FEL materials research programs. Results will be discussed in three areas: two-photon absorption in germanium, FEL-assisted internal photoemission measurements of interface energy barriers (FELIPE), and wavelength-specific laser diamond ablation.
A blood culture study comparing the performance of the new high-volume Bactec resin media to hypertonic medium was conducted in adult patients seen in the emergency department. Twenty milliliters of ...blood was divided equally among three media: hypertonic (NR8A), aerobic high-volume resin (HV26), and anaerobic high-volume resin (HV27). During a 5.5-month period, 2,724 blood cultures were collected; there were 417 (15.3%) positive cultures, of which 233 (8.6%) yielded pathogens and 184 (6.8%) contaminants. For the 257 isolates recovered from 233 cultures yielding pathogens, the isolation rates were: NR8A-194 (75.5%), HV26-204 (79.4%), and HV27-189 (73.5%). We conclude that in this emergency department patient population, the rate and speed of recovery of pathogenic microorganisms is comparable in high-volume resin media and the hypertonic medium but that the high-volume resin media still has a definite advantage over standard nonradiometric media in adults because high-volume blood cultures (20 mL) can be performed using a two-bottle collection set rather than a three-bottle set.
To determine if iodine tincture is a more effective skin antiseptic for blood culture collection than povidone-iodine, an iodophor.
Pairwise comparisons across phases. In phases 1 and 3, blood ...culture skin preparation was performed with the iodophor; in phases 2 and 4, skin preparation was performed with iodine tincture.
Emergency department of a large urban teaching hospital.
All adult patients seen in the emergency department who had blood cultures collected because a systemic bacterial infection was suspected.
The blood culture contamination rate for the iodophor and iodine tincture skin preparations.
A total of 8467 blood cultures were collected during the study, and 421 (4.97%) were classified as contaminated. The contamination rate for the blood cultures collected using the iodophor was 6.25%, and the contamination rate for the cultures using iodine tincture was 3.74%; this difference is statistically significant (P < .00001).
The effectiveness of the skin antiseptic may be an important factor in determining contamination rate in blood culturing. If these results are confirmed by others, then institutions that have a high blood culture contamination rate when using an iodophor for skin preparation should consider changing to iodine tincture.
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