The medicolegal issue of tissue plasminogen activator in ischemic stroke: a review of judiciary decrees in Taiwan.

PURPOSE: Tissue plasminogen activator (tPA) was approved by the Food and Drug Administration for ischemic stroke treatment since 1996 at the United States of America and also 2002 at Taiwan. Since after it is strongly advertised for a promising benefit to early thrombolysis that is further echoed by a recommendation in clinical guidelines from multiple medical associations in worldwide. Because of an overwhelming data of positive benefit collected in the evidence-based medicine database, legal dispute subsequently occurs when tPA is failed to be administrated in appropriate time. METHODS: In order to elucidate the legal viewpoint for tPA used in ischemic stroke, a review of the domestic judiciary decrees regarding this issue was conducted. Cases in Taiwan were executed from the open access database of the Judicial Yuan, Taiwan. The background, legal dispute and judgment of each case were analyzed. RESULTS: Till August, 2010, there were 6 cases in Taiwan. All cases occurred after 2003. The causes of disputes were a loss of chance for thrombolysis due to a delay of diagnosis (4 cases, 67%) and a failure of thrombolytic treatment after a diagnosis of ischemic stroke (2 cases, 23%). All cases were presented to non-neurologists at initial. Five cases expired or terminated into vegetation before litigation. CONCLUSION: A failure of early diagnosis or treatment after a diagnosis of ischemic stroke are important for medicolegal dispute in tPA usage, which is expected to become prevalent in Taiwan in future. A fatal or poor outcome may be a triggering factor for litigation. Therefore, an improvement of the knowledge and practice to increase early diagnosis of ischemic stroke is the key factor for reducing medicolegal issue regarding tPA use in ischemic stroke. This is particularly true for non-neurologist physicians.

The nanoindentation of a copper substrate by single-walled carbon nanocone tips: a molecular dynamics study.

This study dealt with deep nanoindentation of a copper substrate with single-walled carbon nanocones (SWCNCs) as the proximal probe tip, using molecular dynamics (MD) simulations. As an important feature, during the indentation the end part of the SWCNC tip will suffer a narrowing effect due to the radial component of resistant compression from the substrate and then forms into a somewhat flat arrowhead-like shape. The effective cross-sectional area of the SWCNC tip inside the substrate that the resistant force is acting on therefore is reduced to lower the normal resistant force on the tip. The narrowing effect is more significant for longer SWCNC tips. Two categories of SWCNCs are therefore classified according to whether the SWCNC tip buckles at its part inside or outside the substrate. SWCNCs of the first category defined in this paper are found able to indent into the substrate up to a desired depth. Further analyses demonstrate that a longer SWCNC tip of the first category will encounter smaller repulsive force during the indentation and thus require less net work to accomplish the indentation process. Raising temperatures will weaken the narrowing effect, so an SWCNC tip of the first category also encounters greater repulsive force and larger net work in the indentation process performed at a higher temperature. Notably, a permanent hollow hole with high aspect ratio will be produced on the copper substrate, while copper atoms in close proximity to the hole are only slightly disordered, especially when the indentation is manipulated at a lower temperature by using a longer SWCNC tip.