Flat bands and Dirac cones in breathing lattices.

In breathing pyrochlores and kagomes, couplings between neighbouring tetrahedra and triangles are free to differ. Breathing lattices thus offer the possibility to explore a different facet of the rich physics of these systems. Here we consider nearest-neighbour classical Heisenberg interactions, both ferromagnetic and antiferromagnetic, and study how the anisotropy of breathing lattices modifies the mode spectrum of pyrochlore and kagome systems. The nature and degeneracy of the flat bands are shown to be preserved for any value of the anisotropy. These flat bands can coexist with Dirac nodes at the [Formula: see text] point when the model becomes particle-hole symmetric. We also derive the nature of the ground state for the breathing kagome lattice, which bears a spontaneous chirality when neighbouring triangles are alternatively ferromagnetic and antiferromagnetic.

Field-Selective Anomaly and Chiral Mode Reversal in Type-II Weyl Materials.

Three-dimensional condensed matter incarnations of Weyl fermions generically have a tilted dispersion-in sharp contrast to their elusive high-energy relatives where a tilt is forbidden by Lorentz invariance, and with the low-energy excitations of two-dimensional graphene sheets where a tilt is forbidden by either crystalline or particle-hole symmetry. Very recently, a number of materials (MoTe_{2}, LaAlGe, and WTe_{2}) have been identified as hosts of so-called type-II Weyl fermions whose dispersion is so strongly tilted that a Fermi surface is formed, whereby the Weyl node becomes a singular point connecting electron and hole pockets. We here predict that these systems have remarkable properties in the presence of magnetic fields. Most saliently, we show that the nature of the chiral anomaly depends crucially on the relative angle between the applied field and the tilt, and that an inversion-asymmetric overtilting creates an imbalance in the number of chiral modes with positive and negative slopes. The field-selective anomaly gives a novel magneto-optical resonance, providing an experimental way to detect concealed Weyl nodes.

Possible observation of highly itinerant quantum magnetic monopoles in the frustrated pyrochlore Yb2Ti2O7.

The low-energy elementary excitations in frustrated quantum magnets have fascinated researchers for decades. In frustrated Ising magnets on a pyrochlore lattice possessing macroscopically degenerate spin-ice ground states, the excitations have been discussed in terms of classical magnetic monopoles, which do not contain quantum fluctuations. Here we report unusual behaviours of magneto-thermal conductivity in the disordered spin-liquid regime of pyrochlore Yb2Ti2O7, which hosts frustrated spin-ice correlations with large quantum fluctuations owing to pseudospin-1/2 of Yb ions. The analysis of the temperature and magnetic field dependencies shows the presence of gapped elementary excitations. We find that the gap energy is largely suppressed from that expected in classical monopoles. Moreover, these excitations propagate a long distance without being scattered, in contrast to the diffusive nature of classical monopoles. These results suggests the emergence of highly itinerant quantum magnetic monopole, which is a heavy quasiparticle that propagates coherently in three-dimensional spin liquids.

Topology and interactions in a frustrated slab: tuning from Weyl semimetals to C>1 fractional Chern insulators.

We show that, quite generically, a [111] slab of spin-orbit coupled pyrochlore lattice exhibits surface states whose constant energy curves take the shape of Fermi arcs, localized to different surfaces depending on their quasimomentum. Remarkably, these persist independently of the existence of Weyl points in the bulk. Considering interacting electrons in slabs of finite thickness, we find a plethora of known fractional Chern insulating phases, to which we add the discovery of a new higher Chern number state which is likely a generalization of the Moore-Read fermionic fractional quantum Hall state. By contrast, in the three-dimensional limit, we argue for the absence of gapped states of the flat surface band due to a topologically protected coupling of the surface to gapless states in the bulk. We comment on generalizations as well as experimental perspectives in thin slabs of pyrochlore iridates.

Anomalous Hall effect from frustration-tuned scalar chirality distribution in Pr2Ir2O7.

We study the anomalous Hall effect due to noncoplanar magnetism on a pyrochlore structure. We focus on the frustration-induced spatial inhomogeneity of different magnetic low-temperature regimes, between which one can efficiently tune using an external magnetic field. We incorporate nonmagnetic scattering on a phenomenological level so that we can distinguish between the effects of short-range correlations and short-range coherence. We obtain a Hall conductivity (σ(H)) as a function of field strength and direction which compares well to the experimental data of Pr(2)Ir(2)O(7). In particular, we show that the observed peak in σ(H) for H[parallel][111] signals the crossover from zero-field spin ice to kagome ice.

Tetrahedral magnetic order and the metal-insulator transition in the pyrochlore lattice of Cd2Os2O7.

Cd2Os2O7 shows a peculiar metal-insulator transition at 227 K with magnetic ordering in a frustrated pyrochlore lattice, but its magnetic structure in the ordered state and the transition origin are yet uncovered. We observed a commensurate magnetic peak by resonant x-ray scattering in a high-quality single crystal. X-ray diffraction and Raman scattering experiments confirmed that the transition is not accompanied with any spatial symmetry breaking. We propose a noncollinear all-in-all-out spin arrangement on the tetrahedral network made of Os atoms. Based on this we suggest that the transition is not caused by the Slater mechanism as believed earlier but by an alternative mechanism related to the formation of the specific tetrahedral magnetic order on the pyrochlore lattice in the presence of strong spin-orbit interactions.

Off-center rattling and anisotropic expansion of type-I clathrates studied by Raman scattering.

Dynamical motions of the guest ions in type-I clathrates Sr8Ga16Si(30-x)Gex and Ba8Ga16Si(30-x)Gex have been studied by Raman scattering spectroscopy, to clarify the role of guest vibration modes in these systems with unusual thermal transport behaviors. An anomalous decrease of the guest energies with decreasing temperature is observed for both systems. The Ge-doping expands the cage surrounding the 6d site anisotropically for Sr8Ga16Si(30-x)Gex, but isotropically for Ba8Ga16Si(30-x)Gex. Especially for Sr8Ga16Si(30-x)Gex, off-center rattling arises simultaneously with the anisotropic expansion, and it is confirmed that these anomalies play a crucial role to suppress lattice thermal conductivity in these systems.

Pressure-induced superconductor-insulator transition in the spinel compound CuRh2S4.

We performed resistivity measurements in CuRh2S4 under quasihydrostatic pressure of up to 8.0 GPa, and found a pressure-induced superconductor-insulator transition. Initially, with increasing pressure, the superconducting transition temperature T(c) increases from 4.7 K at ambient pressure to 6.4 K at 4.0 GPa, but decreases at higher pressures. With further compression, superconductivity in CuRh2S4 disappears abruptly at a critical pressure P(SI) between 5.0 and 5.6 GPa, when it becomes an insulator.

Content of phylloquinone and menaquinone in the tissues of mummichog Fundulus heteroclitus fed diets containing different forms of vitamin K.

The contents of vitamin K in the plasma and tissues (kidney, liver and gonad) of mummichog Fundulus heteroclitus fed diets supplemented with different vitamin K groups were determined. The vitamin K mainly detected in the gastrointestinal tract of each experimental group was the one supplemented in the respective diet, and all other forms of vitamin K were observed at low concentrations. This implies that the main vitamin K source for mummichog is their food. Further evidence that the main vitamin K source is the food is that the elevation of vitamin K concentrations in the plasma and other tissues in this experiment was brought about by vitamin K added to the feed. The phylloquinone-rich diet raised the phylloquinone concentration in the plasma and the tissues much higher than the diets supplemented with short and/or long chain menaquinones. This indicates that phylloquinone is more easily accumulated into the body of fish than the menaquinone homologues. There were apparent differences in absorption and deposition of vitamin K between females and males. This may be a factor in the high mortality in male mummichog during the spawning season but further clarification of the causes of the mortality is required.

Clinicopathological study of mucous pooling referred to as mucinous component (MUC) in colorectal submucosal invasive carcinomas.

We investigated the significance of a pool of mucin, individually termed mucinous component (MUC), at the leading invasion edge of colorectal submucosal invasive carcinoma (SIC). In particular, we studied the correlation between pathological adverse prognostic factors and stainability of the mucosubstances and tumor-associated glycoconjugates in MUC. We demonstrated that MUCs were present in 21% of SICs, and 20% of SICs with MUC were involved in metastasis or recurrence, while only 6% of SICs without MUC were positive for it (p=0.005). SICs with MUC showed strong staining of carcinoembryonic antigen and Ulex europaeus I in the MUCs as well as in the cancer cells with high-grade atypia. Moreover, the mucins in MUCs predominantly stained for sialomucin. This study was the first to investigate the importance of mucous nodules in colorectal SIC. We concluded that MUC in SIC would be an important adverse prognostic factor, and that we should at least consider employing a similar treatment strategy for it to advanced colorectal carcinoma.

Abdominosacral repair for a rectovaginal fistula with anastomotic stenosis after low anterior resection report of a case.

The management of a postoperative rectovaginal fistula after low anterior resection for rectal cancer is difficult and requires reconstruction of the anastomotic site and fistula. The results of reconstructive operation are often unsatisfactory. Herein, we describe our reconstruction technique using the posterior approach through the vaginal lumen for a high rectovaginal fistula repair. This reconstructive operation is useful for postoperative rectovaginal fistulas accompanied by severe stenosis of the anastomotic site following low anterior resection for rectal cancer.

[A complication with hepatic arterial infusion chemotherapy--a case of sepsis related to catheter tip dislocation to the duodenal bulb].

Extra-arterial dislocation of a catheter is one of the complications with hepatic arterial infusion chemotherapy. The authors report a case of sepsis related to catheter tip dislocation to the duodenal bulb. A 69-year-old man underwent sigmoidectomy for sigmoid colon cancer and partial hepatectomy for synchronous metastasis to the liver. We performed hepatic arterial catheterization via the femoral artery, and the patient underwent prophylactic hepatic arterial infusion chemotherapy with 5-FU. Thirty months later, computed tomography during arteriography (CTA) using a port system revealed the dislocation of catheter tip to the duodenal bulb. He showed no symptoms, so we kept him under observation. Sepsis occurred because of the dislocated catheter 39 months later. After removal of the catheter, the symptoms of sepsis disappeared.

Ileosigmoid anastomosis with exclusion of transected ileal loop for intestinal fistula following total cystectomy of bladder cancer. Report of a case.

We report in this article a new technique of surgical treatment of enterocutaneous or enterovaginal fistula after total cystectomy for three cases of bladder cancer. The surgical outcome was successful in these patients, showing good performance status after this operation. It would seem that this technique is a good indication for enteric fistulas in the bottom of the pelvic cavity, which were difficult to be managed even under the control of total parenteral nutrition.

[Complete responses in patients with unresectable liver metastases from colorectal cancer with weekly high-dose 5-FU plus one-shot CDDP HAI].

Thirty-two patients with unresectable liver metastases from colorectal cancer, treated by intermittent hepatic arterial infusion of high-dose 5-FU combined with CDDP, were assessed. As a result of this treatment, the overall response rate was 65.6%, and eight patients (25%) which contained three autopsy cases revealed a complete response. The mean doses of 5-FU and CDDP which was administered in the eight patients were 24.3 g and 65 mg, respectively. One of the eight patients showed complete disappearance of liver metastasis on the CT scan after arterial infusion of 4.5 g of 5-FU, and necrosis or disappearance of the tumor was present in more than 2/3 of the whole lesion. Autopsy showed focal or zonal necrosis, distorted reconstruction of architecture, and cholangiolitis of the liver which were administered more than 15 g of 5-FU. Intermittent hepatic arterial infusion of high-dose 5-FU combined with CDDP is proved to be a useful locoregional chemotherapy for liver metastasis from colorectal cancer. We should evolve new treatment modalities for extrahepatic metastases, as HAI combined with the systemic chemotherapeutic regimen.

[Complications related to hepatic arterial infusion chemotherapy for liver metastasis from colorectal cancer].

UNLABELLED: We evaluated the complications of hepatic arterial infusion (HAI) chemotherapy in patients (pts) with hepatic metastasis from colorectal cancer. The subjects consisted of 61 pts with hepatic metastasis from colorectal cancer, who were treated by combined chemotherapy with 5-FU and CDDP weekly or continuously. Indwelling route of catheter: 30 via gastroduodenal artery (GDA) at the time of laparotomy ('LP'), 21 via femoral artery (FA) and catheter tip in PHA ('PHA'), 10 via FA and catheter tip is inserted with steel coil into the GDA ('GDA-coil'). Complications resulting in interruption of therapy occurred in 19 pts (31%), and the 'GDA-coil' method had a lower rate of complication than others. There was no difference in the incidence rate of complications between the two chemotherapy regimens. The complications of this therapy were: 8 (13%) cases of hepatic arterial occlusion, 3 (5%) cases of duodenal ulcer, 4 (7%) cases of catheter tip dislocation, 2 (3%) cases of catheter tip dislocation to the duodenal bulb, and 1 (2%) case of liver abscess. Hepatic arterial occlusion occurred frequently in LP. Up to 67% of patients with duodenal ulcer had hepatic arterial occlusion at the same time. All pts with catheter tip dislocation were 'PHA', and all pts with catheter tip dislocation to the duodenal bulb were 'LP'. IN CONCLUSION: 1. The best indwelling route for the catheter is by the 'GDA-coil' method. 2. To diagnose complications soon, regular CTA or DSA is necessary.

[Anabolic steroid abuse and mental disorder].

The literature on the psychiatric aspects of anabolic steroids (AS) abuse in the United States is reviewed. Since the 1980s the use of AS has become prevalent among adults and adolescents who are concerned with muscle size and strength, and the abuse of these agents is regarded as a serious drug problem. Researchers noticed that illicit, high-dose use of AS may produce not only somatic adverse effects but behavioral changes. Several studies using psychometry and questionnaires suggested that characteristic psychological phenomena such as increased aggression and irritability may be observed in AS abusers. Although the evidence determining the addictive potential of AS is limited, some authors provide evidence that the long-term use of AS may lead to a mental disorder which meets the DSM-III-R criteria of psychoactive substance abuse. Detailed case reports of AS-induced mental disorders are scarce, but characteristic symptoms, particularly major mood disturbances, have been recognized. Violent crimes committed by abusers taking large doses of AS have also been highlighted. In these cases the dangerous behavior appears to have been induced by aggression, grandiosity, and rage. This review indicates that empirical data specifying psychiatric effects of AS are not sufficient at present, and more attention needs to be paid to trends in AS abuse in Japan.

Suicide and aging in Japan: an examination of treated elderly suicide attempters.

Although individuals aged 65 and over accounted for 12% of the total population of Japan in 1990, suicides in this age group consisted of 29% of all suicides. The elderly population of Japan is expected to grow rapidly to 24% of the total population by the year 2020, and suicide prevention for the elderly is an urgent mental health problem. Among a total of 1,216 elderly patients who were admitted to the Department of Psychiatry at Tokyo Metropolitan Geriatric Hospital between April 1980 and March 1990, 50 were hospitalized immediately after suicide attempts in order to study their psychosociomedical problems. Because early diagnosis of depression and initiation of proper treatment are indispensable--even if patients do not show obvious depressive symptoms--those who develop persistent somatization and/or delirium should be considered highly suicidal and given special attention. With the cooperation of mental health professionals, it is necessary to educate general practitioners, the public, and the elderly themselves about characteristics of psychiatric disorders and various problems associated with aging. Further research on other elderly Japanese populations, as well as research that examines suicide completion, is needed to confirm the findings of the present study.