Surface terminations control charge transfer from bulk to surface states in topological insulators.

Topological insulators (TI) hold significant potential for various electronic and optoelectronic devices that rely on the Dirac surface state (DSS), including spintronic and thermoelectric devices, as well as terahertz detectors. The behavior of electrons within the DSS plays a pivotal role in the performance of such devices. It is expected that DSS appear on a surface of three dimensional(3D) TI by mechanical exfoliation. However, it is not always the case that the surface terminating atomic configuration and corresponding band structures are homogeneous. In order to investigate the impact of surface terminating atomic configurations on electron dynamics, we meticulously examined the electron dynamics at the exfoliated surface of a crystalline 3D TI (Bi 2 Se 3 ) with time, space, and energy resolutions. Based on our comprehensive band structure calculations, we found that on one of the Se-terminated surfaces, DSS is located within the bulk band gap, with no other surface states manifesting within this region. On this particular surface, photoexcited electrons within the conduction band effectively relax towards DSS and tend to linger at the Dirac point for extended periods of time. It is worth emphasizing that these distinct characteristics of DSS are exclusively observed on this particular surface.

Quantum entanglement control of electron-phonon systems by light irradiation.

We numerically study the dynamics of quantum entanglement between interacting electron-phonon and qubit-spin systems under photoirradiation, employing a model of multiple spins and boson modes. The interplay of the antiferromagnetic exchange and electron-phonon interactions provides us with a phase diagram, wherein each phase is characterized by the ground state property of the electron-phonon system. Light irradiation of the electron-phonon system facilitates the generation of quantum entanglement, according to the spin configuration and the phonon state in the ground state. Analyses using the quantum mutual information and the singular values of the reduced density matrix indicate that the quantum mechanical effect of the irradiated light appears in the state of the material.

[A case of liver nocardiosis associated with Crohn's disease while treating infliximab].

A 23-year-old man, complaining of chronic diarrhea, was given a diagnosis of Crohn's disease. He responded well to steroid therapy and infliximab administration. However, high fever appeared on the 28th day of hospitalization, and CT scan revealed multiple liver abscesses. Gram-positive branched rods were harvested by ultrasonography guided puncture examination. As Nocardia infection was suspected, sulfamethoxazole-trimethoprim was started immediately, and his clinical course improved dramatically. Afterwards, Nocardia farcinica was isolated from the culture of the liver abscess. This case is the first report of liver nocardiosis associated with Crohn's disease. Generally, Nocardia infection can be successfully treated by sulfamethoxazole-trimethoprim therapy. Liver nocardiosis is very rare but could be an important complication for patients with Crohn's disease.

[Case of autoimmune pancreatitis accompanied by autoimmune hemolytic anemia].

A 70-year-old man was initially referred to our hospital complaining of back pain and jaundice. Autoimmune pancreatitis was diagnosed. He responded well to steroid therapy. When he was 73-years-old, he was referred to our hospital again because of anemia. He had a low hemoglobin level of 9.3g/dl, and positive Coombs tests, which were suggestive of autoimmune hemolytic anemia. His laboratory data revealed the recurrence of autoimmune pancreatitis, although he had no symptoms. Steroid therapy was very effective on both occasions. This case is the second reported case of autoimmune pancreatitis accompanied by autoimmune hemolytic anemia in Japan.

Nonlinearity in the dynamics of photoinduced nucleation process.

Coherent nonlinear dynamics of photoinduced cooperative phenomena at 0 K is studied by numerical calculations on a model of molecular crystals. We found that the photoinduced nucleation process is triggered only when a certain amount of excitation energy is supplied in a narrow part of the system; i.e., there exists the smallest size of the cluster of excited molecules which makes the nucleation possible. As a result, the portion of the cooperatively converted molecules is nonlinearly dependent on the photoexcitation strength, which has been observed in various materials.

Nonlinear optical response of wave packets on quantized potential energy surfaces.

We calculated the dynamics of nuclear wave packets in coupled electron-vibration systems and their nonlinear optical responses. We found that the quantized nature of the vibrational modes is observed in pump-probe spectra particularly in weakly interacting electron-vibration systems such as cyanine dye molecules. Calculated results based on a harmonic potential model and molecular orbital calculations are compared with experimental results, and we also found that the material parameters regarding the geometrical structure of potential energy surfaces are directly determined by accurate measurement of time-resolved spectra.

Liver disease in hepatitis C virus carriers identified at blood donation and their outcomes with or without interferon treatment: Study on 1019 carriers followed for 5-10 years.

AIM: To portray liver disease and project outcomes in carriers of hepatitis C virus (HCV) in the general population. METHODS: Liver disease was evaluated in 1019 individuals who were found with HCV infection at blood donation, and they were followed for 5-10 years with or without receiving interferon (IFN). RESULTS: At baseline, chronic hepatitis was detected in 529 (51.9%) HCV carriers and more frequently in men than in women (62.6% [299/478]vs 42.5% [230/541], P < 0.01); cirrhosis was diagnosed in five (0.5% [three men included]) and hepatocellular carcinoma (HCC) in one (0.1% [man]). Of the carriers who were followed for 5 years or longer, loss of HCV-RNA from serum was achieved in 61 (31.0%) of the 197 treated with interferon (IFN) and only one of the 211 (0.5%) without IFN (P < 0.0001). HCC developed in 14 carriers including six ofthe 211 (2.8%) without IFN and eight of the 197 (4.1%) with IFN (six non-responders included). Follow ups of the 949 carriers identified age (P < 0.002), male gender (P < 0.01) and cirrhosis at the baseline (P < 0.0001) as factors contributing to the development of HCC. Cumulative incidence rates of HCC during 10 years among carriers found with chronic hepatitis increased in parallel with the age at the baseline. CONCLUSION: Identification of HCV carriers in the general population and treating those indicated with IFN would help decrease the development of HCC and lift its medical, as well as economic, burdens off society.