Toward surface-enhanced Raman imaging of latent fingerprints.

Exposure to light or heat, or simply a dearth of fingerprint material, renders some latent fingerprints undetectable using conventional methods. We begin to address such elusive fingerprints using detection targeting photo- and thermally stable fingerprint constituents: surface-enhanced Raman spectroscopy (SERS). SERS can give descriptive vibrational spectra of amino acids, among other robust fingerprint constituents, and good sensitivity can be attained by improving metal-dielectric nanoparticle substrates. With SERS chemical imaging, vibrational bands' intensities recreate a visual of fingerprint topography. The impact of nanoparticle synthesis route, dispersal methodology-deposition solvent, and laser wavelength are discussed, as are data from enhanced vibrational spectra of fingerprint components. SERS and Raman chemical images of fingerprints and realistic contaminants are shown. To our knowledge, this represents the first SERS imaging of fingerprints. In conclusion, this work progresses toward the ultimate goal of vibrationally detecting latent prints that would otherwise remain undetected using traditional development methods.

Photo- and thermal-degradation studies of select eccrine fingerprint constituents.

Photo- and thermal-degradation studies on eccrine fingerprint components are presented herein. Dilute distinct solutions of urea, lactic acid, and seven amino acids were deposited on steel coupons and Teflon disks, exposed to artificial sunlight or heat, extracted, and analyzed. This aim of this study was to determine whether the investigated eccrine components, previously determined to be Raman active for a parallel study, experienced photo- or thermally induced degradation, and if so, to determine the rate and identify any detectable products. Neither the amino acids nor urea exhibited photo-degradation; however, when heated for a period of three minutes, the onset of thermal-degradation was initiated at 100 degrees C for the amino acids and 100 degrees C for urea. Lactic acid, the major polymerization initiator of superglue fuming, showed photochemical and thermal-degradation. These results could be used for future development of new latent fingerprint visualization methods, especially when lactic acid is degraded.

Enhancing the quality of aged latent fingerprints developed by superglue fuming: loss and replenishment of initiator.

The recovery and identification of latent fingerprints from a crime scene are crucial to many investigations. The cyanoacrylate (superglue) fuming method (CFM), which develops fingerprints by growing a polymer coating over the print residue, is a powerful method but encounters severe limitations when prints are aged or exposed to harsh environmental conditions. We examine the aging process and how the changes that occur to a fingerprint residue over time influence the growth of polymer during development. We identify loss of initiator by erosion and degradation that, when coupled with a loss of water from the print residue, result in a decreased ability to polymerize ethylcyanoacrylate. Then, we present a methodology by which the ability of aged latent fingerprints to polymerize ethylcyanoacrylate is recovered. Two print enhancement agents, acetic acid and ammonia, are demonstrated to improve the growth of polymer from the print ridges by over an order of magnitude, while retaining the integrity of the print structure. Comparison between the two enhancement agents indicate that the enhancement occurs due to ridge coating by the ammonia or acetic acid and pH control of the latent print.

Preoperative vaginal preparation with baby shampoo compared with povidone-iodine before gynecologic procedures.

STUDY OBJECTIVE: The objective of this study was to compare the postoperative infection rates between patients receiving either povidone-iodine (PI) or baby shampoo vaginal preparations before gynecologic surgery. DESIGN: Cohort study (Canadian Task Force classification II-2). SETTING: University referral center for gynecologic endoscopy. PATIENTS: All patients underwent minimally invasive gynecologic surgery including hysteroscopy or laparoscopy. INTERVENTIONS: The agents used for vaginal preparation were either baby shampoo in a 1:1 dilution with sterile normal saline solution or PI 7.5% scrub solution. MEASUREMENTS AND MAIN RESULTS: Charts were reviewed for evidence of infection within 30 days of surgery (symptoms of urinary tract infection, abdominal or vaginal wound infections, temperature > 100.4 degrees F, and fungal or bacterial vaginitis). A total of 249 cases were collected; 96 subjects underwent surgery before the change to baby shampoo and 153 subjects after. Both groups were well matched for the types of surgery performed, age, risk factors for postoperative infections, and the postoperative diagnosis. The infection rates were 14/96 (14.6%) with PI preparation versus 18/153 (11.8%) with baby shampoo (p = .52). CONCLUSION: Baby shampoo should be studied as an alternative to PI because it is a nonirritating, inexpensive mild detergent. This preliminary study suggests that baby shampoo is as effective as PI in preventing postoperative infection.

Understanding the chemistry of the development of latent fingerprints by superglue fuming.

Cyanoacrylate fuming is a widely used forensic tool for the development of latent fingerprints, however the mechanistic details of the reaction between the fingerprint residue and the cyanoacrylate vapor are not well understood. Here the polymerization of ethyl-cyanoacrylate vapor by sodium lactate or alanine solutions, two of the major components in fingerprint residue, has been examined by monitoring the time dependence of the mass uptake and resultant polymer molecular weight characteristics. This data provides insight into the molecular level actions in the efficient development of latent fingerprints by superglue fuming. The results show that the carboxylate moiety is the primary initiator of the polymerization process and that a basic environment inhibits chain termination while an acidic environment promotes it. The results also indicate that water cannot be the primary initiator in this forensic technique.

Laparoscopic treatment of bowel endometriosis.

The most common site of extragenital endometriosis is the intestinal tract, which accounts for approximately 80% of all extragenital endometriosis. The symptoms of intestinal endometriosis are crampy pain, flatulence, painful tenesmus, hyper-peristalsis, progressive constipation, diarrhea alternating with constipation, and occasionally rectal bleeding. As endometriosis in this location often undergoes fibrotic changes, it can be resistant to hormonal therapy, which makes surgical therapy the only option for many women. Until recently, laparoscopic treatment of bowel endometriosis was thought to be impossible. Development of several safe and effective techniques for laparoscopic treatment of intestinal endometriosis has made such treatment possible. In this chapter, the authors describe five proven techniques for treatment of intestinal endometriosis: shaving, disk excision, anterior rectal wall excision, segmental resection, and appendectomy.

Trace-fiber color discrimination by electrospray ionization mass spectrometry: a tool for the analysis of dyes extracted from submillimeter nylon fibers.

The application of electrospray ionization mass spectrometry (ESI-MS) to trace-fiber color analysis is explored using acidic dyes commonly employed to color nylon-based fibers, as well as extracts from dyed nylon fibers. Qualitative information about constituent dyes and quantitative information about the relative amounts of those dyes present on a single fiber become readily available using this technique. Sample requirements for establishing the color identity of different samples (i.e., comparative trace-fiber analysis) are shown to be submillimeter. Absolute verification of dye mixture identity (beyond the comparison of molecular weights derived from ESI-MS) can be obtained by expanding the technique to include tandem mass spectrometry (ESI-MS/MS). For dyes of unknown origin, the ESI-MS/MS analyses may offer insights into the chemical structure of the compound-information not available from chromatographic techniques alone. This research demonstrates that ESI-MS is viable as a sensitive technique for distinguishing dye constituents extracted from a minute amount of trace-fiber evidence. A protocol is suggested to establish/refute the proposition that two fibers--one of which is available in minute quantity only--are of the same origin.