Bullet fragments have been previously observed in the remains and edible portions of big game animals that were harvested using rifles. The fragmentation issue has attracted attention because traditional hunting bullets are more than 70% lead, which is toxic to humans and scavengers in the ecosystem. We prepared gunshot wounds in ballistic gelatin blocks, and then applied synchrotron X-ray imaging technology to the bullet fragmentation process for the first time. The K edge subtraction (KES) imaging method allowed a clear separation of lead in an image from false positives, including the other major bullet component, copper, and non-lead objects such as bone fragments. The superior brightness of synchrotron radiation was also harnessed to resolve thousands of embedded sub-10 μm fragments, a size range not previously observed using commonly applied X-ray imaging modalities. The results challenge the current understanding of the maximum extent that fragments may be distributed, and the effectiveness of imaging methods used to screen wild game donations at food banks for lead bullet fragments.

Luteolin (LUT) is a flavonoid found in several edible and medicinal plants. It is recognized for its biological activities such as antioxidant, anti-inflammatory, neuroprotective, and antitumor effects. However, the limited water solubility of LUT leads to poor absorption after oral administration. Nanoencapsulation may improve the solubility of LUT. Nanoemulsions (NE) were selected for the encapsulation of LUT due to their biodegradability, stability, and ability to control drug release. In this work, chitosan (Ch)-based NE was developed to encapsulate luteolin (NECh-LUT). A 2³ factorial design was built to obtain a formulation with optimized amounts of oil, water, and surfactants. NECh-LUT showed a mean diameter of 67.5 nm, polydispersity index 0.174, zeta potential of +12.8 mV, and encapsulation efficiency of 85.49%. Transmission electron microscopy revealed spherical shape and rheological analysis verified the Newtonian behavior of NECh-LUT. SAXS technique confirmed the bimodal characteristic of NECh-LUT, while stability analysis confirmed NECh-LUT stability when stored at room temperature for up to 30 days. Finally, in vitro release studies showed LUT controlled release up to 72 h, indicating the promising potential of NECh-LUT to be used as novel therapeutic option to treat several disorders.

Deposition of a carbonaceous contaminant layer on surfaces exposed to radiation exceeding 7–10 eV is ubiquitous in many fields of research. The mechanism of this deposition process is still debated. A scanning transmission x-ray microscope has been used to create and interrogate carbonaceous deposits with photon energies spanning the C 1s ionization edge. For equal fluence, the rate of carbon deposition is proportional to the x-ray absorption spectrum of the deposited material. The results are consistent with a deposition mechanism involving secondary electrons. Implications of this measurement with regard to future generations of high volume photolithography are discussed.

A cryo scanning transmission X-ray microscope, the cryo-STXM, has been designed and commissioned at the Canadian Light Source synchrotron. The instrument is designed to operate from 100 to 4000 eV (λ = 12.4 − 0.31 nm). Users can insert a previously frozen sample, through a load lock, and rotate it ±70° in the beam to collect tomographic data sets. The sample can be maintained for extended periods at 92 K primarily to suppress radiation damage and a pressure on the order of 10⁻⁹ Torr to suppress sample contamination. The achieved spatial resolution (30 nm) and spectral resolution (0.1 eV) are similar to other current soft X-ray STXMs, as demonstrated by measurements on known samples and test patterns. The data acquisition efficiency is significantly more favorable for both imaging and tomography. 2D images, 3D tomograms, and 4D chemical maps of automotive hydrogen fuel cell thin sections are presented to demonstrate current performance and new capabilities, namely, cryo-spectrotomography in the soft X-ray region.