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Amorphous metallic glasses (MGs) convert to crystalline solids upon annealing at a high temperature. Such a phase change, however, does not occur with the local melting caused by damage cascades introduced by ion irradiation, although the resulting thermal spikes can reach temperatures > 1000 K. This is because the quenching rate of the local melting zone is several orders of magnitude higher than the critical cooling rate for MG formation. Thus the amorphous structure is sustained. This mechanism increases the highest temperature at which irradiated MG sustains amorphous phase. More interestingly, if an irradiated MG is pre-annealed to form a polycrystalline structure, ion irradiation can locally convert this crystalline phase to an amorphous phase if the grains are nanometers in size and comparable to the damage cascade volume size. Combining pre-annealing and site selective ion irradiation, patterned crystalline-amorphous heterogeneous structures have been fabricated. This finding opens new doors for various applications.
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INTRODUCTION: In 2015 the British Medical Ultrasound Society released a referral justification document for rejection of inappropriate ultrasound referrals to help manage increasing demand and ensure correct utilisation of diagnostic imaging tests. In our trust, referrals that were not aligned with the guidance were cancelled and returned to general practitioners, providing reasons for cancellation and advising other diagnostic tests if appropriate.Methodology: In total, 1000 cases cancelled between April and August 2019 were retrospectively audited by a team of clinical specialist sonographers. Interoperator agreement against BMUS justification guidelines and safety of this cancellation process were established. Duplicate imaging referrals, referrals made that should have been placed on management pathways or referrals cancelled by the patient directly were excluded in the safety assessment. RESULTS: There was strong agreement amongst sonographers regarding cancellations. After exclusions, 389 cases were included for review. The majority (90.5%) required no onward imaging and were therefore deemed cancelled appropriately. There were 37 patients found with pathology on subsequent imaging, two of which were found to have cancer and the remainder with benign pathology. CONCLUSIONS: Overall, we found the cancellation process to be safe and the justification document easy to utilise in practice. This process has ensured a minimal waiting time for ultrasound imaging is maintained and that demand can be managed to meet the available capacity.
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The most common mechanism of traumatic injury is ground-level fall. The objective of this study was to understand how patients sustaining falls and their outcomes have evolved. An institutional trauma database was used to identify adult patients who suffered a fall and were admitted to a Level I trauma center during two distinct time periods: 1998 to 2003 (past) and 2008 to 2013 (current). Data on anticoagulant use and comorbidities was gathered by retrospective chart review of patients treated during 2003 and 2013. Univariable analyses and multivariable regression were used to evaluate demographics and outcomes. A total of 6116 patients were identified, with a 24 per cent increase in number of falls between groups. Current fall patients are older (70 vs 66 years, P < 0.001), more often admitted to intensive care (28 vs 12%, P < 0.001), have longer lengths of stay (5 vs 4 days, P < 0.001), are frequently discharged to skilled nursing facilities (24 vs 8%, P < 0.001), and have higher mortality (5 vs 3%, P = 0.002). The adjusted odds of mortality for patients treated during 2003 and 2013 was associated with age, gender, injury severity score, and Glasgow Coma Scale score. Current fall patients use more health care resources and have worse outcomes, despite advances in trauma and geriatric care.