α-Clustering in atomic nuclei from first principles with statistical learning and the Hoyle state character.

A long-standing crucial question with atomic nuclei is whether or not α clustering occurs there. An α particle (helium-4 nucleus) comprises two protons and two neutrons, and may be the building block of some nuclei. This is a very beautiful and fascinating idea, and is indeed plausible because the α particle is particularly stable with a large binding energy. However, direct experimental evidence has never been provided. Here, we show whether and how α(-like) objects emerge in atomic nuclei, by means of state-of-the-art quantum many-body simulations formulated from first principles, utilizing supercomputers including K/Fugaku. The obtained physical quantities exhibit agreement with experimental data. The appearance and variation of the α clustering are shown by utilizing density profiles for the nuclei beryllium-8, -10 and carbon-12. With additional insight by statistical learning, an unexpected crossover picture is presented for the Hoyle state, a critical gateway to the birth of life.

Rod-shaped Nuclei at Extreme Spin and Isospin.

The anomalous rod shape in carbon isotopes has been investigated in the framework of the cranking covariant density functional theory, and two mechanisms to stabilize such a novel shape with respect to the bending motion, extreme spin, and isospin are simultaneously discussed for the first time in a self-consistent and microscopic way. By adding valence neutrons and rotating the system, we have found the mechanism stabilizing the rod shape; i.e., the σ orbitals (parallel to the symmetry axis) of the valence neutrons, important for the rod shape, are lowered by the rotation due to the Coriolis term. The spin and isospin effects enhance the stability of the rod-shaped configuration. This provides a strong hint that a rod shape could be realized in nuclei towards extreme spin and isospin.

Existence of an exotic torus configuration in high-spin excited states of 40Ca.

We investigate the possibility of the existence of the exotic torus configuration in the high-spin excited states of (40)Ca. We here consider the spin alignments about the symmetry axis. To this end, we use a three-dimensional cranked Skyrme Hartree-Fock method and search for stable single-particle configurations. We find one stable state with the torus configuration at the total angular momentum J=60 h and an excitation energy of about 170 MeV in all calculations using various Skyrme interactions. The total angular momentum J=60 h consists of aligned 12 nucleons with the orbital angular momenta Λ=+4, +5, and +6 for spin-up or -down neutrons and protons. The obtained results strongly suggest that a macroscopic amount of circulating current breaking the time-reversal symmetry emerges in the high-spin excited state of (40)Ca.

Linear chain structure of four-α clusters in 16O.

We investigate the linear chain configurations of four-α clusters in 16O using a Skyrme cranked Hartree-Fock method and discuss the relationship between the stability of such states and angular momentum. We show the existence of a region of angular momentum (13-18ℏ) where the linear chain configuration is stabilized. For the first time we demonstrate that stable exotic states with a large moment of inertia (ℏ2/2Θ∼0.06-0.08 MeV) can exist.

Microscopic study of the triple-α reaction.

We present a microscopic dynamical study of the reactions involving three 4He clusters. We show that the much discussed triple-α linear chain configuration of 12C is formed with a certain lifetime and subsequently makes a transition to a triangular configuration of 12C and then to a configuration near the ground state. Time-dependent Hartree-Fock theory coupled with a density constraint is used to study the properties of these configurations.

Coexistence of covalent superdeformation and molecular resonances in an unbound region of 12Be.

The generalized two-center cluster model, which can treat static structures and dynamical reactions in excited states, is applied to the light neutron-rich system, 12Be=alpha+alpha+4N. We discuss the change of the neutrons' configuration around two alpha cores from the covalent structure to the ionic one. We show that, in the unbound region above particle-decay thresholds, the ionic configurations appear as the molecular resonances of alpha+8He, 6He+6He, and 5He+7He. A new type of superdeformation is possible, and we find here a covalent superdeformation with a hybrid configuration of both the covalent and ionic structures. The excitation of these exotic structures through the two-neutron transfer reaction is also discussed.

Signatures for multi-alpha-condensed states.

An experimental way of testing Bose-Einstein condensation of alpha clusters in the atomic nucleus is reported. The enhancement of cluster emission and the multiplicity partition of possible emitted clusters could be direct signatures for the condensed states. The barrier for the emission of clusters, such as (8)Be and (12)C(O(+)(2)), is calculated and compared with the barrier for the sequential emission of 2 or 3alpha particles from the compound nucleus. For the calculations, a simple approach using a folded Woods-Saxon potential is used.

Equilateral-triangular shape in 14C.

An equilateral-triangular shape of three alpha clusters surrounded by excess neutrons is suggested for 14C, based on the molecular-orbit model. It is found that the attractive interaction between an excess neutron and an alpha particle stabilizes the K(pi)=0(+) and 3(-) rotational bands, which demonstrates an equilateral-triangular symmetry. This K(pi)=3(-) band at 3 MeV below the 10Be+alpha threshold energy corresponds to the experimentally observed band built on top of the second 3(-) state. A positive-parity rotational band (0(+), 2(+), 4(+)) arises similarly. These two bands suggest a molecular 3-alpha structure stabilized by the excess neutrons and can be viewed as a realization of the alpha crystallization in the dilute nuclear medium.

[A case of Vibrio cholerae non-O1 septicemia with liver cirrhosis].

A case of Vibrio cholerae non-O1 septicemia is described in this paper. A 45-year-old male with a three year history of liver cirrhosis, was admitted to our division with hematemesis, abdominal pain, high fever and a loss of consciousness. Three days before onset of symptoms, he traveled to Ishigaki Island and ate a raw lobster. Two days after, his temperature rose to 39.7 degrees C and the blood pressure dropped to 36/- mmHg. By endoscopic examination, an ulcer was found in the stomach, and the bleeding was stopped by electrical coagulation. Blood culture showed growth of V. cholerae non-O1. The organism was found to be sensitive to OFLX, CZX, MINO, LMOX and CP. Although DIC, infections of fungus and MRSA occurred as complications, he recovered by adequate procedures. Subsequently, he left this division after eight weeks. There are various reports related to V. cholerae non-O1 septicemia in foreign countries, but few cases have been reported in Japan. And these cases had severe underlying diseases such as leukemia and liver cirrhosis.

[Pharmacokinetics of cefodizime in patients undergoing hemodialysis].

The object of this study was to establish the most effective regimen of cefodizime (CDZM) for patients with chronic renal failure undergoing hemodialysis (HD). T 1/2 beta of CDZM upon 1 g intravenous administration was 3.50 +/- 0.72 hours in an on-HD group, and it was 11.26 +/- 3.89 hours in an off-HD group. When CDZM was administered consecutively at a dose of 1 g or 2 g only after HD, the serum concentration of CDZM was maintained at levels sufficient to exert antibacterial activity, and no tendency for accumulation was observed. The most effective regimen of CDZM to HD patients, therefore, has been that in which concluded to administration was done only after completion of HD, in a dose of 1 g for mild infections and that of 2 g for severe infections.

[Pharmacokinetics of cefotiam in patients undergoing continuous ambulatory peritoneal dialysis].

The pharmacokinetics of cefotiam (CTM) was investigated in 7 patients undergoing continuous ambulatory peritoneal dialysis (CAPD). One gram of CTM was infused either intravenously (i.v. group) or intraperitoneally (i.p. group). In the i.v. group, the serum concentration of CTM at 6 hours after infusion was 25.9 mg/L and the half-life value was 5.09 hours, while the peak value of CTM in dialysate was 12.4 mg/L. In the i.p. group without peritonitis, the dialysate concentration of CTM at 6 hours after infusion was 108.6 mg/L. The serum concentration at 15 minutes after infusion was 3.0 mg/L, the corresponding peak value was 14.0 mg/L at 4 and 6 hours after infusion.

[Pharmacokinetics of cefmenoxime in renal-failure patients undergoing continuous arteriovenous hemofiltration].

We investigated the pharmacokinetics of cefmenoxime (CMX) administrated to renal-failure patients undergoing continuous arteriovenous hemofiltration (CAVH). CAVH was carried out with a filter (0.5 m2) employing a PAN-50P (hollow fiber type) made of polyacrylonitrile membrane, with a blood flow rate of 100 ml/min and a filtration rate of 1,200 ml/hr. At 5 and 300 minutes after the CMX administration, the concentrations of CMX in the serum were 126.8 mg/L and 31.5 mg/L, respectively. The T1/2 beta was 3.55 hours. In 300 minutes after the administration of CMX, the total amount of CMX contained in the filtrate corresponded to 11.6% of the administered dose.