100 μA-100 kV Photon-counting X-ray Computed Tomography System Using an LSO-MPPC Detector and a High-Speed Comparator and its Application to Gadolinium Imaging

A high-sensitive x-ray computed tomography (CT) system is useful for decreasing absorbed dose for patients, and we performed preliminary experiments for first-generation photon-counting CT using a high-sensitive single detector. X-ray photons are detected using an LSO [Lu₂(SiO₄)O] single crystal scintillator and a multipixel photon counter (MPPC). The photocurrent from the MPPC is amplified by a current-voltage amplifier and an integrator, and the event pulse is sent to a high-speed comparator. Logical pulses are then produced by the comparator and are counted by a counter card. Tomography is accomplished by repeated linear scans and rotations of an object, and projection curves of the object are obtained by the linear scan. The count rate decreased with increase in lower level voltage of the comparator V_l, and the maximum count rate was 265 kcps at a V_l of 0.4 V. The exposure time for obtaining a tomogram was 10 minutes at a scan step of 0.5 mm and a rotation step of 1.0°. The image contrast of gadolinium medium slightly varied with change in V_l. We carried out low-dose-rate photon-counting CT at a tube current of 100 μA and a tube voltage of 100 kV. The energy-dispersive effect of the CT image was confirmed by selecting V_l. The absorbed dose for objects can be reduced using the linear detector consisting of plural LSO-MPPC detectors.     

Exploring willingness to engage with law enforcement among syringe service program participants in New York City

BackgroundIn New York City (NYC), 1,487 unintentional overdose deaths occurred in 2017, largely driven by the presence of fentanyls in the illicit drug market. In response to fentanyl-involved overdoses, law enforcement entities both nationally and in NYC have taken a new interest in overdose events. This study explored attitudes toward and willingness to engage with police among NYC syringe service program (SSP) participants, a population likely to have had experiences with overdose and/or police.MethodsBetween March and July 2017, 332 surveys were conducted with a convenience sample of NYC SSP participants.ResultsMost respondents (76%) reported ever being arrested for a drug-related crime. Few respondents (5%) reported a previous arrest in the context of an overdose event. Of the 62 respondents who had witnessed an overdose in the previous 12 months, 25% had not called 911 because of concerns about law enforcement. Over half (51%) of all respondents reported they would not be willing to aid police in their investigation of the person who supplied the drugs.ConclusionPolice investigations of both fatal and non-fatal drug overdose events have the potential to exacerbate mistrust of law enforcement and discourage emergency medical service utilization among PWUD.     

Conceptualising learning through simulation: An expansive approach for professional and personal learning

This paper explores different ways of conceptualising the learning that occurs as student nurses engage in simulation experiences. The conceptual frameworks discussed in this paper draw upon the work of Benner and Sutphen (2007) and Engeström (1994). Benner and Sutphen's work highlights the complex nature of situated knowledge in practice disciplines such as nursing. They suggest that knowledge must be constantly integrated within the curriculum through pedagogies of interpretation, formation, contextualisation and performance. These pedagogies present a framework, which may enhance our understanding of the impact of simulation upon student learning. Engeström's work on activity theory, recognises the links between learning and the environment of work and highlights the possibilities for learning to inspire change, innovation and the creation of new ideas. His notion of expansive learning offers nurse education a means of reconceptualising the learning that occurs during simulation. Together these frameworks present an opportunity for nurse education to articulate and theorise the learning inherent in simulation activities.