We report on four electron paramagnetic resonance sensors for dynamic magnetic field measurements at 36 mT, 100 mT, 360 mT, and 710 mT. The sensors are based on grounded co-planar microwave resonators operating at about 1 GHz and 3 GHz, realized using printed circuit board technology, and on single-chip integrated microwave oscillators operating at about 10 GHz and 20 GHz, realized using complementary metal-oxide-semiconductor technology. The sensors are designed to mark precisely the moment when a time-dependent magnetic field attains a specific value. The trigger from the sensor can be used to preset the output of real-time magnetic field measurement systems, called "B-trains," which are in operation at several large synchrotron installations, including five of the CERN's particle accelerators. We discuss in detail the performance achieved, in particular, the magnetic field resolution that is in the range of 0.1 nT/Hz1/2-6 nT/Hz1/2. The effects of material anisotropy and temperature are also discussed. Finally, we present a detailed characterization of the sensors with field ramps as fast as 5 T/s and field gradients as strong as 12 T/m.
We report on two ferrimagnetic resonance (FMR) sensors for absolute dynamic magnetic field measurements at 36 and 100 mT. The sensors are designed to mark precisely and reproducibly the moment when a time-transient magnetic field attains a specific value. The trigger from the sensor can then be used for real-time magnetic field measurement systems, called "B-trains," which are in operation at several large synchrotron installations including five of CERN's particle accelerators. We discuss in detail the design, the operation, and the performance of the FMR sensors based on two different types of printed circuit board (PCB) resonator structures.
Until the law in the United Kingdom (UK) changed in May 2016 so called "legal highs" or "new psychoactive substances" were freely available in high street shops across the UK. Following prohibition these drugs are still easily purchased illegally via the internet. We report a case of a patient who self-administered 3-fluorophenmetrazine intravenously with catastrophic consequences. Adverse effects were almost immediate with symptoms of malaise and tachycardia. Two days post administration he was transferred to the intensive therapy unit with acute kidney injury and irreversible four limb ischaemia. He required a period of renal replacement therapy and bilateral lower limb amputation. This case highlights the fact that new psychoactive substances have many unintended adverse effect which have not been previously described. Multiple routes of administration are used by people taking these agents including intravenously. Medical practitioners should always consider ingestion of new psychoactive substances in the differential diagnosis of acutely ill patients.
