Biomedical subjects

S Shimoura

Publications and source records attributed to S Shimoura.

11 recordsLinked to original sources

PubMed2006

Observation of strong low-lying E1 strength in the two-neutron halo nucleus 11Li.

An exclusive measurement has been made of the Coulomb dissociation of the two-neutron halo nucleus 11Li at 70 MeV/nucleon at RIKEN. Strong low-energy (soft) E1 excitation is observed, peaked at about Ex = 0.6 MeV with B(E1) = 1.42(18) e2fm2 for Erel < or = 3 MeV, which was largely missed in previous measurements. This excitation represents the strongest E1 transition ever observed at such low excitation energies. The spectrum is reproduced well by a three-body model with a strong two-neutron correlation, which is further supported by the E1 non-energy-weighted cluster sum rule.

Journal Article↗

PubMed2006

Vanishing N = 20 shell gap: study of excited states in (27,28)Ne.

This Letter reports on the (1)H((28)Ne, (28)Ne) and (1)H((28)Ne, (27)Ne) reactions studied at intermediate energy using a liquid hydrogen target. From the cross section populating the first 2(+) excited state of (28)Ne, and using the previously determined BE(2) value, the neutron quadrupole transition matrix element has been calculated to be M(n)=13.8 +/- 3.7 fm(2). In the neutron knockout reaction, two low-lying excited states were populated in (27)Ne. Only one of them can be interpreted by the sd shell model while the additional state may intrude from the fp shell. These experimental observations are consistent with the presence of fp shell configurations at low excitation energy in (27,28)Ne nuclei caused by a vanishing N=20 shell gap at Z=10.

Journal Article↗

PubMed2004

Anomalously hindered E2 strength B(E2;2+(1)-->0+) in 16C.

The electric quadrupole transition from the first 2(+) state to the ground 0(+) state in 16C is studied through measurement of the lifetime by a recoil shadow method applied to inelastically scattered radioactive 16C nuclei. The measured mean lifetime is 77+/-14(stat)+/-19(syst) ps. The central value of mean lifetime corresponds to a B(E2;2+(1)-->0(+)) value of 0.63e(2) fm(4), or 0.26 Weisskopf units. The transition strength is found to be anomalously small compared to the empirically predicted value.

Journal Article↗

PubMed2002

Localized heat urticaria in a patient is associated with a wealing response to heated autologous serum.

We report a case of localized heat urticaria in a 71-year-old woman who developed weals and loss of consciousness after taking a bath. Exposing her skin to heat at 40 degrees C or immersing her hands in water at 40 degrees C produced urticarial lesions and increased her plasma histamine level. Desensitization with hot water improved her symptoms and normalized her plasma histamine level after heat challenge. An intracutaneous injection of her serum produced no reaction, while an injection of her serum that had been heated at 40 degrees C for 15 min induced a weal flare response. Further examination revealed that the weal-inducing activity of her heated serum remained for at least for 6 h and that treatment of her serum at 60 degrees C for 2 h did not abrogate its weal-inducing activity. These findings indicate that certain materials in her serum that are activated by heat are responsible for the development of her anaphylactic and urticarial reactions and that these reactions may be mediated by histamine.

Aged↗

PubMed1993