Factors affecting the polarity and magnitude of photoresponse of transient photodetectors.

The addition of an insulating layer (I) between one of the metal electrodes (M) and the photoactive semiconducting layer (S) in a standard organic MSM solar cell architecture changes the DC photocurrent response into a strong transient signal. Such a device can, in simple terms, be thought of as a charging voltage source (S) in contact with a charging capacitor (I). The magnitude of the photocurrent signal can be strongly enhanced through the intimate contact of the active layer with the insulating layer, if the various pre-polarizations within the device act synergically. In this study, the effect of the built-in potentials within the device on the polarity and magnitude of the photocurrent response is studied using the well-characterized bulk heterojunction blend system of poly(3-hexylthiophenone):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) as the semiconductor layer, and an ionic liquid as the insulating layer. This study shows that the polarity of the response is not simply determined by the energy level difference of the outer electrodes, but through a delicate interplay of all the energy levels in the device. Furthermore, these observations could be reproduced for devices with a solid-state insulator layer, where possible side-effects of the ionic liquid, such as swelling and doping, could be considered absent.

Peri-operative radiation exposure: Are overweight patients at increased risks?

The aim of this study was to identify if there was a correlation between body mass index (BMI) and intra-operative radiation exposure. A retrospective review of 81 patients who had sliding hip screw fixation for femoral neck fractures in one year was completed, recording body mass index (BMI), screening time, dose area product (DAP), American Society of Anesthesiologists (ASA) grade, seniority of operating surgeon and complexity of the fracture configuration. There was a statistically significant correlation between dose area product and BMI. There was no statistically significant relationship between screening time and BMI. There was no statistical difference between ASA grade, seniority of surgeon, or complexity of fracture configuration and dose area product. Simulated stochastic risks were increased for overweight patients. Overweight patients are exposed to increased doses of radiation regardless of length of screening time. Surgeons and theatre staff should be aware of the increased radiation exposure during fixation of fractures in overweight patients and, along with radiographers, ensure steps are taken to minimise these risks. Whilst such radiation dosages may have little adverse effect for individual patients, these findings may be of more relevance and concern to staff that will be exposed to increased radiation.

On-tip photodetection: a simple and universal platform for optoelectronic screening.

A novel platform for transient photodetector component screening has been developed whereby an optical fiber tip serves as the counter electrode when placed in a variety of dielectric media, connected to a photoresponsive working electrode. The soft processing conditions allow for ubiquitous photodetection for organic and biological systems.

Sucrose as analgesia for neonates experiencing "mild" pain.

Health care professionals who care for neonates have few treatment options for the management of mild, sporadic painful events, such as those associated with venipuncture. A number of research studies have demonstrated sucrose to be an efficacious analgesic for mild procedural pain in neonates. The historical therapy of the "sugar nipple" has even been replaced with sucrose. A discussion of the pharmacologic principles, available research regarding dose-response relationships and implications for nursing care is presented in this article to allow the reader to consider how this adjunctive therapy may be incorporated into care of the neonate. Rather than considering sucrose as a replacement for traditional analgesics, this easily administered and seemingly safe intervention could be used as another adjunctive therapy in treating mild pain for neonates. Future directions of research may identify the precise mechanism of action that sucrose takes in the neonate, the gestational and chronological ages when sucrose is most efficacious, and the consequences of frequent or repeated dosing with term and low birth weight infants.