Effect of atomic layer deposition on the quality factor of silicon nanobeam cavities

In this work we study the effect of thin-film deposition on the quality factor (Q) of silicon nanobeam cavities. We observe an average increase in the Q of 38±31% in one sample and investigate the dependence of this increase on the initial nanobeam hole sizes. We note that this process can be used to modify cavities that have larger than optimal hole sizes following fabrication. Additionally, the technique allows the tuning of the cavity mode wavelength and the incorporation of new materials, without significantly degrading Q

Post-mortem computed tomography (PMCT) and PMCT-angiography after transvascular cardiac intervention

Background and Purpose: During the last years, Post Mortem Computed Tomography (PMCT) has become an integral part of the autopsy. PMCT-angiography may augment PMCT. Both exams have proven their value in visualizing complications after heart surgery. Therefore, they should also show complications after transvascular interventions. This assumption initiated our project: to evaluate the possibilities of PMCT and PMCT-angiography after transvascular cardiac interventions. Material and Methods: In our archives of characteristic and typical PMCT findings, we searched for observations on preceding transvascular cardiac interventions. Additionally, we reviewed our PMCTangiographies (N=140). Results: After transvascular cardiac interventions, PMCT and PMCT-angiography visualized bleeding, its amount and its origin, cardiac tamponade, free and covered perforations, transvascular implanted valves and their position, catheters and pacemakers with fractures, abnormal loops and bending. Bubbles in the coronary vessels (indicating air embolism) become visible. Conclusion: After transvascular cardiac interventions, PMCT and PMCT-angiography show complications and causes of death. They prove a correct interventional approach and also guide autopsy. In isolated cases, they may even replace autopsy

Skin tension and cleavage lines (Langer' s lines) causing distortion of ante- and postmortem wound morphology

The assessment of individual wounds at autopsy may be complicated by the superimposition of a number of injuries or damage to tissues that occurred after death, either of which has the potential to distort the morphology of the initial injury. Additional factors that may change the shape of wounds are (1) the relationship of the wound to the so-called skin cleavage lines (Langer’s lines) and (2) tension placed on the skin. Three autopsy cases are reported to demonstrate once more how wound morphology may be altered by such factors. In case 1, rectangular stab wounds to the base of the neck in a 53-year-old man, which suggested that a square or rectangular tool may have caused the injuries, were altered to more typical knife stab wounds once skin tension had been released at autopsy. The uppermost wounds, however, continued to gape due to the effects of skin cleavage lines. In case 2, slit-like wounds resembling stab wounds in the neck of a 54-year-old woman found in a river were shown to be circular once skin tension had been released. In case 3, the effects of either cleavage lines or skin tension could be demonstrated on excised wounds from a 43-year-old man whose body had also been found in a river; tensile forces easily changed circular into slit-like wounds. Tension and/or skin cleavage lines may transform round skin defects into slit-like wounds resembling knife stab wounds, round out genuine stab wounds and artefactually lengthen stab wounds. These factors must be taken into consideration carefully when wounds are assessed at the death scene prior to autopsy.Roger W. Byard, Axel Gehl, Michael Tsoko