Theory of electromagnon in the multiferroic Mn perovskites: Vital role of higher harmonic components of the spiral spin order

We study theoretically the electromagnon and its optical spectrum (OS) of the terahertz-frequency regime in the magnetic-spiral-induced multiferroic phases of the rare-earth (R) Mn perovskites, RMnO3, taking into account the elliptical deformation or the higher harmonics of the spiral spin configuration, which has been missed so far. A realistic spin Hamiltonian, which gives phase diagrams in agreement with experiments, resolves a long standing puzzle, i.e., the double-peak structure of the OS with a larger low-energy peak originating from magnon modes hybridized with the zone-edge state. We also predict the magnon branches associated with the electromagnon, which can be tested by neutron-scattering experiment.Comment: 5 pages, 4 figure

Competing Orders and Disorder-induced Insulator to Metal Transition in Manganites

Effects of disorder on the two competing phases, i.e., the ferromagnetic metal and the commensurate charge/lattice ordered insulator, are studied by Monte Carlo simulation. The disorder suppresses the charge/lattice ordering more strongly than the ferromagnetic order, driving the commensurate insulator to the ferromagnetic metal near the phase boundary in the pure case. Above the ferromagnetic transition temperature, on the contrary, the disorder makes the system more insulating, which might cause an enhanced colossal magnetoresistance as observed in the half-doped or Cr-substituted manganites. No indication of the percolation or the cluster formation is found, and there remain the charge/lattice fluctuations instead which are enhanced toward the transition temperature.Comment: 5 pages including 4 figure

Entropy-Driven Reentrant Behavior in CMR Manganites

We discuss the origin of the reentrant behaviors of insulating states above the Curie temperature of the colossal magnetoresistance manganites. We consider a system where charge ordering and ferromagnetism compete with each other. In the presence of randomness which pins charge order fluctuations, entropy-driven reentrant behaviors will appear, which explains the typical temperature dependence of the resistivity for CMR manganites.Comment: 2 pages, 1 figure, submitted to SCES'0

Endometrial Cancer Diagnosed by the Presence of Bone Metastasis and Treated with Zoledronic Acid: A Case Report and Review of the Literature

Bone metastasis from endometrial cancer is rare. We report a case of endometrial cancer which was diagnosed by the presence of bone metastasis and treated with zoledronic acid. A 57-year-old woman complaining of progressive right hip pain consulted an orthopedist. She had no gynecologic complaints. X-rays revealed an osteolytic lesion of the right ischium. Bone scintigraphy was subsequently carried out and showed isotope accumulation in the right ischium. Computed tomography revealed an enlarged uterus; the patient consequently consulted a gynecologist. Histological sections of an endometrial biopsy showed endometrioid adenocarcinoma. Hysterectomy and bilateral salpingo-oophorectomy, as well as bone biopsy of the right ischium, were therefore carried out. A moderately differentiated endometrioid adenocarcinoma was expressed in the corpus. Histopathological examination of the bone biopsy also revealed adenocarcinoma. The final diagnosis was stage IVB endometrial cancer with bone and lung metastasis. Good pain relief was achieved due to chemotherapy. However, 2 months after completion of the chemotherapy, the patient was administered zoledronic acid because her hip pain had gradually increased. Following zoledronic acid administration, the hip pain reduced. Radiotherapy was then given for the right ischial metastasis after the ninth course of zoledronic acid therapy because the metastasis site had increased and the possibility of a pathological fracture had risen. However, the patient died 21 months after the initial treatment because of disease progression

Randomness Effect on Multicritical Phenomena in Double-Exchange Systems

Double-exchange model interacting with adiabatic phonons is studied in the presence of randomness by using the Monte-Carlo method and the systematic size-scaling analysis. A bicritical behavior is found between the ferromagnetic metal and the charge-ordered insulator. We find the distinct response to the randomness between these two states, which agrees well with the experimental results in the colossal magnetoresistance manganites.Comment: 2 pages including 2 figures, Proceedings for ICM200

Carcinosarcoma of the Uterine Corpus with Alpha-Fetoprotein-Producing Hepatoid Adenocarcinoma: A Report of Two Cases

We report two cases of uterine carcinosarcoma associated with alpha-fetoprotein (AFP)-producing hepatoid adenocarcinoma. Samples were obtained from two women aged 63 and 82 years. Serum AFP levels of the two samples were 10,131 and 401 ng/ml, respectively. Histologically, in both cases the tumor cells were composed of hepatoid adenocarcinoma component and sarcoma component including rhabdomyosarcoma. Immunohistochemical analyses revealed that AFP was expressed in the cytoplasm of the carcinomatous component. After surgery, the patients received six courses of carboplatin/paclitaxel chemotherapy, and the serum levels of AFP decreased to normal range. The first patient is alive and well at the 2-year follow-up, while the second patient died of disease 1 year after initial operative treatment. This is, to our knowledge, the second report of carcinosarcoma of the uterine corpus with AFP-producing hepatoid adenocarcinoma, as proven by immunohistochemical analyses

Mechanisms of Neuronal Death in Synucleinopathy

α-synuclein is a key molecule in the pathogenesis of synucleinopathy including Parkinson's disease and multiple system atrophy. In this mini-review, we mainly focus on recent data obtained from cellular models of synucleinopathy and discuss the possible mechanisms of neurodegeneration. Recent progress suggests that the aggregate formation of α-synuclein is cytoprotective and that its precursor oligomer (protofibril) may be cytotoxic. The catechol-derived quinones are the candidate molecules that facilitate the oligomer formation of α-synuclein. Furthermore, the cellular membranes are shown to be the primary targets injured by mutant α-synucleins, and the mitochondrial dysfunction seems to be an initial step in the neuronal death

Three-year survival in primary cardiac angiosarcoma

A healthy 18-year-old girl was referred to our hospital for further evaluations of cardiac angiosarcoma. Transthoracic echocardiography showed an immobile 4.6 cm×3.7 cm cardiac mass. The mass was occupying right atrial chamber and partially, invading into annulus of tricuspid valve on transesophageal echocardiography. At surgery, the mass was seen to be protruding from right atrial appendage and adhering to right side of pericardium. The histological findings were consistent with cardiac angiosarcoma and immunological staining was positive for CD34 and CD31. Afterward, although she received radiochemotherapy, she died of metastasis of cardiac angiosarcoma more than three years after surgical resection

Application of a Microreactor in the Oxidative Dehydrogenation of Propane to Propylene on Calcium Hydroxyapatite and Magnesium ortho-Vanadate Doped and Undoped with Palladium

A microreactor was employed for the oxidative dehydrogenation of propane to propylene in order to suppress a deep oxidation of the resultant propylene to CO and CO2. Magnesium ortho-vanadate, doped and undoped with palladium, and calcium hydroxyapatite, were used as catalysts while the reaction temperature was controlled by steady- and unsteady-state conditions. The enhancement of the selectivity to propylene was the most advantageous effect from using the microreactor, and it occurred when calcium hydroxyapatite was used under an unsteady-state. For example, the selectivity to propylene was 0 and 73.0% using a fixed-bed continuous-flow reactor and the microreactor, respectively, under almost identical propane conversion of 3.1 and 3.2%, respectively. The advantageous effect was also achieved, although to a lesser degree, when magnesium ortho-vanadate was used undoped with palladium under both steady- and unsteady-state conditions. However these advantageous effects of the microreactor were not observed with magnesium ortho-vanadate doped with palladium. With regard to the selectivity to propylene, the redox nature of the catalysts seemed to influence the performance of the microreactor