Emergence of the less common cannabinoid Δ8 -Tetrahydrocannabinol in a doping sample

Δ⁸ -Tetrahydrocannabinol (Δ⁸ -THC) as isomer of the well-known Δ⁹ -THC has a similar mode of action, and the potency was estimated to be two thirds compared with Δ⁹ -THC. Content of Δ⁸ -THC in plant material is low, but formulations containing Δ⁸ -THC in high concentrations are gaining popularity. Δ⁸ -THC is to be regarded as prohibited substance according to the Prohibited List of the World Anti-Doping Agency (WADA). Contradictory results between initial testing procedure and confirmatory quantitation for 11-Nor-9-carboxy-Δ⁹ -tetrahydrocannabinol (Δ⁹ -THC-COOH) of a doping control sample gave rise for follow-up testing procedures. After alkaline hydrolysis and liquid-liquid extraction, the sample was analyzed by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) using isocratic elution instead of gradient elution, which is used for standard procedure. Isocratic elution resulted in two peaks instead of one using gradient elution. Both peaks showed same fragmentation. Using certified reference materials, one peak could be assigned to Δ⁹ -THC-COOH and the other one with higher intensity to the less common 11-Nor-9-carboxy-Δ⁸ -Tetrahydrocannabinol (Δ⁸ -THC-COOH) in a concentration of approximately 1200 ng/ml. As complementary method, gas chromatography tandem mass spectrometry (GC-MS/MS) can also be used for identification. Here Δ⁸ - and Δ⁹ -THC-COOH can be distinguished by chromatography and by fragmentation. Additional investigations of doping control samples containing Δ⁹ -THC-COOH revealed the simultaneous presence of Δ⁸ -THC-COOH in low concentrations (0.22-8.91 ng/ml) presumably due to plant origin. Percentage of Δ⁸ -THC-COOH varies from 0.05 to 2.83%. In vitro experiments using human liver microsomes showed that Δ⁸ -THC is metabolized in the same way as Δ⁹ -THC.

Optical pumping of quantum dot micropillar lasers

Arrays of quantum dot micropillar lasers are an attractive technology platform for various applications in the wider field of nanophotonics. Of particular interest is the potential efficiency enhancement as a consequence of cavity quantum electrodynamics effects, which makes them prime candidates for next generation photonic neurons in neural network hardware. However, particularly for optical pumping, their power-conversion efficiency can be very low. Here we perform an in-depth experimental analysis of quantum dot microlasers and investigate their input-output relationship over a wide range of optical pumping conditions. We find that the current energy efficiency limitation is caused by disadvantageous optical pumping concepts and by a low exciton conversion efficiency. Our results indicate that for non-resonant pumping into the GaAs matrix (wetting layer), 3.4% (0.6%) of the optical pump is converted into lasing-relevant excitons, and of those only 2% (0.75%) provide gain to the lasing transition. Based on our findings, we propose to improve the pumping efficiency by orders of magnitude by increasing the aluminium content of the AlGaAs/GaAs mirror pairs in the upper Bragg reflector.

[Sustainable Strategies for Health Promotion in Urban Districts]

In a city district striving to sustainably develop into a healthy living environment for its residents, cooperation with locally active players as well as network management and the inclusion of citizens and local businesses as non-professional multipliers are particularly promising strategies for developing effective ways of promoting health and integrating them into existing structures in order to reach the target group.

Bispectral index versus COMFORT score to determine the level of sedation in paediatric intensive care unit patients: a prospective study

INTRODUCTION

Most clinicians give sedatives and analgesics according to their professional experience and the patient's estimated need for sedation. However, this approach is prone to error. Inadequate monitoring of sedation and analgesia may contribute to adverse outcomes and complications. With this in mind, data obtained continuously using nonstimulating methods such as bispectral index (BIS) may have benefits in comparison with clinical monitoring of sedation. The aim of this prospective observational trial was to evaluate the use of electroencephalographic (EEG) BIS for monitoring sedation in paediatric intensive care unit (PICU) patients.

METHODS

Forty paediatric patients (<18 years) were sedated for mechanical ventilation in a cardiac surgical and general PICU. In each paediatric patient BIS and COMFORT score were obtained. The study protocol did not influence ongoing PICU therapy. BIS and corresponding COMFORT score were collected three times for each patient. Measurements with the best starting EEG impedances were analyzed further. Deep sedation was defined as a COMFORT score between 8 and 16, and light sedation as a score between 17 and 26. Biometric and physiological data, and Pediatric Risk of Mortality III scores were also recorded.

RESULTS

There was a good correlation (Spearman's rho 0.651; P = 0.001) between BIS and COMFORT score in the presence of deep sedation and low starting impedance. Receiver operating characteristic (ROC) analysis revealed best discrimination between deep and light sedation at a BIS level of 83.

CONCLUSION

In the presence of deep sedation, BIS correlated satisfactorily with COMFORT score results if low EEG impedances were guaranteed.