Antiplatelet therapy after coronary intervention in Asia and Japan

Currently available clinical database was mostly developed in North America and Europe (Western Countries). Clinical database of Asian patients are still not large enough to develop Asian region specific clinical guidelines, although the population of patients in the majority of Asia countries are increasing rapidly. Marked ethnic and life-style heterogeneity within Asian region also makes it difficult to develop Asian region specific Evidence-based clinical practice guidelines. In general, there are certain differences in the background epidemiology of the athero-sclerotic and thrombotic diseases in Asia countries and Western ones such as Asian patients are more prone to cerebrovascular disease (CVD) than coronary artery disease (CAD). Accordingly, there also are marked differences in the use of antiplatelet agents in Asian patients underwent coronary intervention (such as frequent use of cilostazol) as compared to those living in the Western countries. Currently available database also suggests the difference in side effects of anti -platelet agents in Asian patients as compared to Western ones such as relatively high incidence of hepatic dysfunction with the use of thienopiridine. In the future, it would be important to clarify the detailed difference of Asian patients and Western ones in regards to the effects and side effects of antiplatelet therapy by the multi-national prospective observation registry and clinical trials including equal number of Asian and Western patients. It would also be important for Asian physician to develop scientifically valid methods to import the results of “Global Evidence” with appropriate modification for the clinical practice in patients living in the specific region of Asia.

Role of Multichance Fission in the Description of Fission-Fragment Mass Distributions at High Energies

Fission-fragment mass distributions were measured for ^{237-240}U, ^{239-242}Np, and ^{241-244}Pu populated in the excitation-energy range from 10 to 60 MeV by multinucleon transfer channels in the reaction ^{18}O+^{238}U at the Japan Atomic Energy Agency tandem facility. Among them, the data for ^{240}U and ^{240,241,242}Np were observed for the first time. It was found that the mass distributions for all the studied nuclides maintain a double-humped shape up to the highest measured energy in contrast to expectations of predominantly symmetric fission due to the washing out of nuclear shell effects. From a comparison with the dynamical calculation based on the fluctuation-dissipation model, this behavior of the mass distributions was unambiguously attributed to the effect of multichance fission.

Ultra-strong and damage tolerant metallic bulk materials: A lesson from nanostructured pearlitic steel wires

Structural materials used for safety critical applications require high strength and simultaneously high resistance against crack growth, referred to as damage tolerance. However, the two properties typically exclude each other and research efforts towards ever stronger materials are hampered by drastic loss of fracture resistance. Therefore, future development of novel ultra-strong bulk materials requires a fundamental understanding of the toughness determining mechanisms. As model material we use today’s strongest metallic bulk material, namely, a nanostructured pearlitic steel wire, and measured the fracture toughness on micron-sized specimens in different crack growth directions and found an unexpected strong anisotropy in the fracture resistance. Along the wire axis the material reveals ultra-high strength combined with so far unprecedented damage tolerance. We attribute this excellent property combination to the anisotropy in the fracture toughness inducing a high propensity for micro-crack formation parallel to the wire axis. This effect causes a local crack tip stress relaxation and enables the high fracture toughness without being detrimental to the material’s strength.