Thoracic spine stab injury with a retained knife.

A female was admitted to a Major Trauma Centre with an isolated thoracic spine stab injury involving a retained knife. The patient was haemodynamically stable with an unremarkable peripheral neurological examination. A CT scan with three-dimensional image reconstruction showed the knife blade lodged in the T11 vertebra with its tip close to the spinal cord, aorta and inferior vena cava. A multidisciplinary trauma team, including anaesthetists, vascular, neurosurgeons and general surgeons, agreed on the treatment strategy. The lodged knife was safely withdrawn in the operating theatre with the patient in a prone position under sedation and local anaesthesia. Following the procedure, neurological examination remained normal, and an MRI scan revealed no spinal cord injury. We discuss the management of penetrating spinal injuries, the importance of detailed preoperative imaging, timely multidisciplinary input and how to safely remove a knife when a prone position prevents standard airway management.

Single-pollen analysis by laser-induced breakdown spectroscopy and Raman microscopy.

The application of laser-induced breakdown spectroscopy to the analysis of single biological microparticles (bioaerosols) is described, exemplified here for a range of pollens. Spectra were recorded by exposure of the pollen to a single laser pulse from a Nd:YAG laser (lambda = 1064 nm, Ep approximately 30 mJ). The intensities of the single-pulse laser-induced breakdown spectra fluctuated dramatically, but an internal signal calibration procedure was applied that referenced elemental line intensities to the carbon matrix of the sample (represented by molecular bands of CN and C2). This procedure allowed us to determine relative element concentration distributions for the different types of pollen. These pollens exhibited some distinct concentration variations, for both major and minor (trace) elements in the biomatrix, through which ultimately individual pollens might be identified and classified. The same pollen samples were also analyzed by Raman microscopy, which provided molecular compositional data (even with spatial resolution). These data allowed us to distinguish between biological and nonbiological specimens and to obtain additional classification information for the various pollen families, complementing the laser-induced breakdown spectroscopy measurement data.