Short-Lived Radioisotope

The isotope ^{98}Tc decays to ^{98}Ru with a half-life of 4.2×10^{6} yr and could have been present in the early Solar System. In this Letter, we report on the first calculations of the production of ^{98}Tc by neutrino-induced reactions in core-collapse supernovae (the ν process). Our predicted ^{98}Tc abundance at the time of solar system formation is not much lower than the current measured upper limit raising the possibility for its detection in the not too distant future. We show that, if the initial abundance were to be precisely measured, the ^{98}Tc nuclear cosmochronometer could be used to evaluate a much more precise value of the duration time from the last core-collapse supernova to the formation of the solar system. Moreover, a unique and novel feature of the ^{98}Tc ν-process nucleosynthesis is the large contribution (∼20%) from charged current reactions with electron antineutrinos. This means that ^{98}Tc becomes a unique new ν-process probe of the temperature of the electron antineutrinos.

[Development of shunt technology especially for idiopathic normal pressure hydrocephalus].

Outcome of the treatment on hydrocephalus especially in idiopathic normal pressure hydrocephalus (iNPH) shows the better outcome after shunting operation according to the evolution of the shunt system and the better management of shunt complications, and also, comprehension of the pathophysiology of NPH. The history of shunt system is benefit for the understanding of the now available shunt system. The first generation system is emerge as the typical standard differential pressure valves. The second generation valves was developed for the management of overdrainage problems and siphoning control. Japanese guidelines of iNPH recommended the use of the programmable valve for shunt system. Now, various shunt system have been developed for the treatment of hydrocephalus. After millennium, the new third generation shunt systems that are consisted with programmable valve and anti-siphon devices, are now line up for the management of iNPH. The new recognition of NPH and the familiarity with these various shunt devices are enable to the new stage of the clinical sciene of the diagnosis and the management of iNPH.