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We report the properties of an A-site spinel magnet, CoAl2-xGaxO4, and analyze its anomalous, low-temperature magnetic behavior, which is derived from inherent, magnetically frustrated interactions. Rietveld analysis of the x-ray diffraction profile for CoAl2-xGaxO4revealed that the metallic ions were randomly distributed in the tetrahedral (A-) and octahedral (B-) sites in the cubic spinel structure. The inversion parameterηcould be controlled by varying the gallium (Ga) composition in the range 0.055 ⩽η⩽ 0.664. The composition-induced Néel-to-spin-glass (NSG) transition occurred between 0.05 ⩽η⩽ 0.08 and was verified by measurements of DC-AC susceptibilitiesχand thermoremanent magnetization (TRM) below the Néel transition temperatureTN. The relaxation rate and derivative with respect to temperature of TRM increased at bothTNand the spin glass (SG) transition temperatureTSG. The TRM decayed rapidly above and below these transitions. TRM was highly sensitive to macroscopic magnetic transitions that occurred in both the Néel and SG phases of CoAl2-xGaxO4. In the vicinity of the NSG boundary, there was a maximum of the TRM relaxation rate atTmax
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BACKGROUND: Petrous internal carotid artery aneurysms are very rare vascular lesions, which may present with otalgia and life-threatening massive otorrhoea. CASE REPORT: An 84-year-old woman presented at a local otolaryngology clinic with progressive otalgia due to an acute exacerbation of chronic otitis media. She was referred with left-sided massive otorrhoea following Eustachian tube catheterisation. She suffered another massive otorrhoea with epistaxis during left-sided ear cleaning at a clinic visit. Contrast-enhanced computed tomography and computed tomography angiography revealed a left-sided aneurysm and adjacent stenosis at the left internal carotid artery. Coil embolisation of the petrous internal carotid artery aneurysm was performed with percutaneous transluminal angioplasty followed by dilatation of the stenosis. CONCLUSION: Computed tomography angiography should be performed immediately when a patient reports massive otorrhoea. Endovascular occlusion is a treatment option as it avoids complications of open surgical ligation procedures.
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Aneurisma , Enfermedades de las Arterias Carótidas , Trompa Auditiva , Aneurisma Intracraneal , Femenino , Humanos , Anciano de 80 o más Años , Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/cirugía , Constricción Patológica/patología , Dolor de Oído , Aneurisma/complicaciones , Enfermedades de las Arterias Carótidas/complicaciones , Cateterismo , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/patología , Aneurisma Intracraneal/cirugíaRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Solids with competing interactions often undergo complex phase transitions with a variety of long-periodic modulations. Among such transition, devil's staircase is the most complex phenomenon, and for it, CeSb is the most famous material, where a number of the distinct phases with long-periodic magnetostructures sequentially appear below the Néel temperature. An evolution of the low-energy electronic structure going through the devil's staircase is of special interest, which has, however, been elusive so far despite 40 years of intense research. Here, we use bulk-sensitive angle-resolved photoemission spectroscopy and reveal the devil's staircase transition of the electronic structures. The magnetic reconstruction dramatically alters the band dispersions at each transition. Moreover, we find that the well-defined band picture largely collapses around the Fermi energy under the long-periodic modulation of the transitional phase, while it recovers at the transition into the lowest-temperature ground state. Our data provide the first direct evidence for a significant reorganization of the electronic structures and spectral functions occurring during the devil's staircase.
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AIMS: To study the mechanism of the antibacterial action of tea polyphenols such as catechins and theaflavins against Bacillus coagulans, and the interaction of epigallocatechin gallate (EGCg) or theaflavin 3,3'-di-O-gallate (TFDG) with the surface of B. coagulans cells was investigated. METHODS AND RESULTS: The antibacterial activities of EGCg and TFDG against B. coagulans cells were measured by counting of the viable cells after the mixing with each polyphenol. Bactericidal effect of TFDG was shown at the concentration of greater than or equal to 62·5 mg l-1 ; however, at the same concentration, EGCg did not. According to the results of two dimensional (2D)-electrophoresis analysis, TFDG seemed to interact with cytoplasmic membrane proteins. The activity of the glucose transporters of the cells decreased 40% following the treatment with TFDG of 62·5 mg l-1 ; however, this decrease was only slight in case of EGCg. This result was in accordance with the strength of their bactericidal activities. CONCLUSION: Our results suggest that the direct interaction between membrane proteins and TFDG is an important factor in the antibacterial activity of polymerized catechins, affecting their functions and leading to cell death. SIGNIFICANCE AND IMPACT OF THE STUDY: Tea polyphenols can effectively use the prevention of product spoilage in the food and beverage industry.
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Antibacterianos/farmacología , Bacillus coagulans/efectos de los fármacos , Biflavonoides/farmacología , Catequina/análogos & derivados , Bacillus coagulans/metabolismo , Biflavonoides/metabolismo , Catequina/metabolismo , Catequina/farmacología , Membrana Celular/efectos de los fármacos , Glucosa/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Viabilidad Microbiana/efectos de los fármacos , Polifenoles/química , Polifenoles/farmacología , Té/químicaRESUMEN
The chiral crystal is characterized by a lack of mirror symmetry and inversion center, resulting in the inequivalent right- and left-handed structures. In the noncentrosymmetric crystal structure, the spin and momentum of electrons are expected to be locked in the reciprocal space with the help of the spin-orbit interaction. To reveal the spin textures of chiral crystals, we investigate the spin and electronic structure in a p-type semiconductor, elemental tellurium, with the simplest chiral structure by using spin- and angle-resolved photoemission spectroscopy. Our data demonstrate that the highest valence band crossing the Fermi level has a spin component parallel to the electron momentum around the Brillouin zone corners. Significantly, we have also confirmed that the spin polarization is reversed in the crystal with the opposite chirality. The results indicate that the spin textures of the right- and left-handed chiral crystals are hedgehoglike, leading to unconventional magnetoelectric effects and nonreciprocal phenomena.
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The major breakthroughs in understanding of topological materials over the past decade were all triggered by the discovery of the Z2-type topological insulator-a type of material that is insulating in its interior but allows electron flow on its surface. In three dimensions, a topological insulator is classified as either 'strong' or 'weak'1,2, and experimental confirmations of the strong topological insulator rapidly followed theoretical predictions3-5. By contrast, the weak topological insulator (WTI) has so far eluded experimental verification, because the topological surface states emerge only on particular side surfaces, which are typically undetectable in real three-dimensional crystals6-10. Here we provide experimental evidence for the WTI state in a bismuth iodide, ß-Bi4I4. Notably, the crystal has naturally cleavable top and side planes-stacked via van der Waals forces-which have long been desirable for the experimental realization of the WTI state11,12. As a definitive signature of this state, we find a quasi-one-dimensional Dirac topological surface state at the side surface (the (100) plane), while the top surface (the (001) plane) is topologically dark with an absence of topological surface states. We also find that a crystal transition from the ß-phase to the α-phase drives a topological phase transition from a nontrivial WTI to a normal insulator at roughly room temperature. The weak topological phase-viewed as quantum spin Hall insulators stacked three-dimensionally13,14-will lay a foundation for technology that benefits from highly directional, dense spin currents that are protected against backscattering.
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INTRODUCTION: The current study aimed to compare cytology using SurePath® (SP)-LBC and biliary tissue histology (BTH) for the diagnosis of biliary disease. METHODS: Between January 2014 and December 2016, 57 patients underwent endoscopic retrograde cholangiopancreatography for the diagnosis of biliary disease. Biliary cytological samples were processed using SP-LBC and subsequently BTH was performed. A final diagnosis was confirmed by surgery (23 malignant cases) and clinical follow-up (34 benign and malignant cases): 18 extrahepatic cholangiocarcinoma; 17 intrahepatic/hilar cholangiocarcinoma (intra/H-CC); eight other malignant disease; and 14 benign biliary disease. The diagnoses made using SP-LBC and BTH were classified into four categories: (1) benign; (2) indeterminate; (3) suspicious for malignancy/malignant; and (4) inadequate. In addition, diagnostic accuracy was compared between SP-LBC and BTH. RESULTS: Although 23% (13/57) of BTH samples were classified as inadequate, all SP-LBC cases were classified as adequate. Among 43 malignant cases, 11 normal, four indeterminate and 28 suspicious for malignancy/malignant were found using SP-LBC (26%, 9% and 65%, respectively), in contrast to 10 inadequate, nine normal, 10 indeterminate and 14 suspicious for malignancy/malignant observed using BTH (23%, 21%, 23%, and 33%, respectively). The identification of malignant cells was strikingly different between SP-LBC and BTH. Furthermore, limited to intra/H-CC, accuracy was significantly higher using SP-LBC than using BTH (P < .001). CONCLUSIONS: SP-LBC of the biliary tract is a useful and reliable method for diagnosing biliary malignant disease and has an advantage over BTH for detecting malignant cells and accurately diagnosing intra/H-CC.
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Neoplasias de los Conductos Biliares/patología , Colangiocarcinoma/patología , Citodiagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de los Conductos Biliares/diagnóstico por imagen , Colangiocarcinoma/diagnóstico por imagen , Colangiopancreatografia Retrógrada Endoscópica , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Experimental determinations of bulk band topology in the solid states have been so far restricted to only indirect investigation through the probing of surface states predicted by electronic structure calculations. We here present an alternative approach to determine the band topology by means of bulk-sensitive soft x-ray angle-resolved photoemission spectroscopy. We investigate the bulk electronic structures of the series materials, Ce monopnictides (CeP, CeAs, CeSb, and CeBi). By performing a paradigmatic study of the band structures as a function of their spin-orbit coupling, we draw the topological phase diagram and unambiguously reveal the topological phase transition from a trivial to a nontrivial regime in going from CeP to CeBi induced by the band inversion. The underlying mechanism of the phase transition is elucidated in terms of spin-orbit coupling in concert with their semimetallic band structures. Our comprehensive observations provide a new insight into the band topology hidden in the bulk states.
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Adenosina Desaminasa/deficiencia , Inmunodeficiencia Combinada Grave/diagnóstico , Anticuerpos Monoclonales Humanizados/uso terapéutico , Exantema/etiología , Femenino , Fiebre de Origen Desconocido/etiología , Humanos , Lactante , Infliximab/uso terapéutico , Inmunodeficiencia Combinada Grave/tratamiento farmacológicoRESUMEN
Neuroblastoma is a vascularized pediatric tumor derived from neural crest stem cells that displays vasculogenic mimicry and can express a number of stemness markers, such as SOX2 and NANOG. Tumor relapse is the major cause of succumbing to this disease, and properties attributed to cancer stem-like cells (CSLC), such as drug-resistance and cell plasticity, seem to be the key mechanisms. However, the lack of controllable models that recapitulate the features of human neuroblastoma limits our understanding of the process and impedes the development of new therapies. In response to these limitations, we engineered a perfusable, vascularized in vitro model of three-dimensional human neuroblastoma to study the effects of retinoid therapy on tumor vasculature and drug-resistance. METHODS: The in vitro model of neuroblastoma was generated using cell-sheet engineering and cultured in a perfusion bioreactor. Firstly, we stacked three cell sheets containing SKNBE(2) neuroblastoma cells and HUVEC. Then, a vascular bed made of fibrin, collagen I and HUVEC cells was placed onto a collagen-gel base with 8 microchannels. After gelling, the stacked cell sheets were placed on the vascular bed and cultured in the perfusion bioreactor (perfusion rate: 0.5 mL/min) for 4 days. Neuroblastoma models were treated with 10µM isotretionin in single daily doses for 5 days. RESULTS: The bioengineered model recapitulated vasculogenic mimicry (vessel-like structure formation and tumor-derived endothelial cells-TECs), and contained CSLC expressing SOX2 and NANOG. Treatment with Isotretinoin destabilized vascular networks but failed to target vasculogenic mimicry and augmented populations of CSLCs expressing high levels of SOX2. Our results suggest that CSLCs can transdifferentiate into drug resistant CD31+-TECs, and reveal the presence of an intermediate state STEC (stem tumor-derived endothelial cell) expressing both SOX2 and CD31. CONCLUSION: Our results reveal some roles of SOX2 in drug resistance and tumor relapse, and suggest that SOX2 could be a therapeutic target in neuroblastoma.
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Resistencia a Antineoplásicos/efectos de los fármacos , Isotretinoína/farmacología , Neuroblastoma/irrigación sanguínea , Neuroblastoma/tratamiento farmacológico , Ingeniería de Tejidos/métodos , Ensayos de Selección de Medicamentos Antitumorales/instrumentación , Ensayos de Selección de Medicamentos Antitumorales/métodos , Células Endoteliales/efectos de los fármacos , Células Endoteliales/patología , Regulación Neoplásica de la Expresión Génica , Humanos , Proteína Homeótica Nanog/genética , Proteína Homeótica Nanog/metabolismo , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/patología , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/patología , Neuroblastoma/mortalidad , Perfusión , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismoRESUMEN
Weyl fermions have been observed as three-dimensional, gapless topological excitations in weakly correlated, inversion-symmetry-breaking semimetals. However, their realization in spontaneously time-reversal-symmetry-breaking phases of strongly correlated materials has so far remained hypothetical. Here, we report experimental evidence for magnetic Weyl fermions in Mn3Sn, a non-collinear antiferromagnet that exhibits a large anomalous Hall effect, even at room temperature. Detailed comparison between angle-resolved photoemission spectroscopy (ARPES) measurements and density functional theory (DFT) calculations reveals significant bandwidth renormalization and damping effects due to the strong correlation among Mn 3d electrons. Magnetotransport measurements provide strong evidence for the chiral anomaly of Weyl fermions-namely, the emergence of positive magnetoconductance only in the presence of parallel electric and magnetic fields. Since weak magnetic fields (approximately 10 mT) are adequate to control the distribution of Weyl points and the large fictitious fields (equivalent to approximately a few hundred T) produced by them in momentum space, our discovery lays the foundation for a new field of science and technology involving the magnetic Weyl excitations of strongly correlated electron systems such as Mn3Sn.
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Tumor suppressor TP53 is frequently mutated in colorectal cancer (CRC), and most mutations are missense type. Although gain-of-functions by mutant p53 have been demonstrated experimentally, the precise mechanism for malignant progression in in vivo tumors remains unsolved. We generated ApcΔ716 Trp53LSLâ¢R270H villin-CreER compound mice, in which mutant p53R270H was expressed in the intestinal epithelia upon tamoxifen treatment, and examined the intestinal tumor phenotypes and tumor-derived organoids. Mutant Trp53R270H, but not Trp53-null mutation accelerated submucosal invasion with generation of desmoplastic microenvironment. The nuclear accumulation of p53 was evident in ApcΔ716 Trp53R270H/R270H homozygous tumors like human CRC. Although p53 was distributed to the cytoplasm in ApcΔ716 Trp53+/R270H heterozygous tumors, it accumulated in the nuclei at the invasion front, suggesting a regulation mechanism for p53 localization by the microenvironment. Importantly, mutant p53 induced drastic morphological changes in the tumor organoids to complex glandular structures, which was associated with the acquisition of invasiveness. Consistently, the branching scores of human CRC that carry TP53 mutations at codon 273 significantly increased in comparison with those of TP53 wild-type tumors. Moreover, allografted ApcΔ716 Trp53R270H/R270H organoid tumors showed a malignant histology with an increased number of myofibroblasts in the stroma. These results indicate that nuclear-accumulated mutant p53R270H induces malignant progression of intestinal tumors through complex tumor gland formation and acquisition of invasiveness. Furthermore, RNA sequencing analyses revealed global gene upregulation by mutant p53R270H, which was associated with the activation of inflammatory and innate immune pathways. Accordingly, it is possible that mutant p53R270H induces CRC progression, not only by a cell intrinsic mechanism, but also by the generation or activation of the microenvironment, which may synergistically contribute to the acceleration of submucosal invasion. Therefore, the present study indicates that nuclear-accumulated mutant p53R270H is a potential therapeutic target for the treatment of advanced CRCs.
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Regulación Neoplásica de la Expresión Génica , Neoplasias Intestinales/patología , Neoplasias Hepáticas/secundario , Mutación , Proteína p53 Supresora de Tumor/genética , Proteína de la Poliposis Adenomatosa del Colon/metabolismo , Animales , Progresión de la Enfermedad , Perfilación de la Expresión Génica , Humanos , Neoplasias Intestinales/genética , Neoplasias Intestinales/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Invasividad Neoplásica , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Microambiente Tumoral , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
We use a surface-selective angle-resolved photoemission spectroscopy and unveil the electronic nature on the topmost layer of Sr_{2}RuO_{4} crystal, consisting of slightly rotated RuO_{6} octahedrons. The γ band derived from the 4d_{xy} orbital is found to be about three times narrower than that for the bulk. This strongly contrasts with a subtle variation seen in the α and ß bands derived from the one-dimensional 4d_{xz/yz}. This anomaly is reproduced by the dynamical mean-field theory calculations, introducing not only the on-site Hubbard interaction but also the significant Hund's coupling. We detect a coherence-to-incoherence crossover theoretically predicted for Hund's metals, which has been recognized only recently. The crossover temperature in the surface is about half that of the bulk, indicating that the naturally generated monolayer of reconstructed Sr_{2}RuO_{4} is extremely correlated and well isolated from the underlying crystal.
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We present an angle-resolved photoemission study of the electronic structure of the three-dimensional pyrochlore iridate Nd_{2}Ir_{2}O_{7} through its magnetic metal-insulator transition. Our data reveal that metallic Nd_{2}Ir_{2}O_{7} has a quadratic band, touching the Fermi level at the Γ point, similar to that of Pr_{2}Ir_{2}O_{7}. The Fermi node state is, therefore, a common feature of the metallic phase of the pyrochlore iridates. Upon cooling below the transition temperature, this compound exhibits a gap opening with an energy shift of quasiparticle peaks like a band gap insulator. The quasiparticle peaks are strongly suppressed, however, with further decrease of temperature, and eventually vanish at the lowest temperature, leaving a nondispersive flat band lacking long-lived electrons. We thereby identify a remarkable crossover from Slater to Mott insulators with decreasing temperature. These observations explain the puzzling absence of Weyl points in this material, despite its proximity to the zero temperature metal-insulator transition.
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Objective:To implore the effect of continuous positive airway pressure (CPAP) therapy on dizziness patients and its mechanism. Method:Seventy-five dizziness patients were enrolled. All patients accepted polysomnographic test, dizziness handicap inventory, Pitsburgh sleep quality index and Epworth sleepiness scale before and after CPAP therapy. Patients were divided into two groups according to a polysomnographic test: OSAHS group (AHI≥15) and without OSAHS group (AHI<15); divided into three groups according to dizziness handicap inventory score: mild dizziness group (0
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Presión de las Vías Aéreas Positiva Contínua , Mareo/terapia , Apnea Obstructiva del Sueño/complicaciones , Adulto , Anciano , Mareo/etiología , Humanos , Persona de Mediana Edad , Sueño , Apnea Obstructiva del Sueño/terapia , VértigoRESUMEN
Infective endocarditis (IE) of infants is rare, most of which occur associated with congenital heart disease or its cardiac surgery. We experienced a case of sudden death of a four-month-old male infant without congenital heart disease. It was elucidated by postmortem examination that the dead had suffered severe IE, which led him to death. In the microbiological genetic analysis using histological section, the pathogen causing inflammation in the present case was identified as Lactococcus lactis subspecies, although Staphylococci have been reported to be common and important one. Previously reported infectious diseases by Lactococcus lactis subspecies were all adult cases and this is the first report of an infantile death due to Lactococcal IE according to our knowledge. Any fatal disease may be included in sudden death cases targeted for forensic autopsy, even if it is rare. It is expected for forensic pathologists that they note such case and share each experience among themselves and other medical fields to develop a strategy for prevention.
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Endocarditis Bacteriana/microbiología , Infecciones por Bacterias Grampositivas/microbiología , Lactococcus/aislamiento & purificación , Muerte Súbita del Lactante/etiología , Autopsia , Humanos , Lactante , MasculinoRESUMEN
Strong spin-orbit coupling fosters exotic electronic states such as topological insulators and superconductors, but the combination of strong spin-orbit and strong electron-electron interactions is just beginning to be understood. Central to this emerging area are the 5d transition metal iridium oxides. Here, in the pyrochlore iridate Pr2Ir2O7, we identify a non-trivial state with a single-point Fermi node protected by cubic and time-reversal symmetries, using a combination of angle-resolved photoemission spectroscopy and first-principles calculations. Owing to its quadratic dispersion, the unique coincidence of four degenerate states at the Fermi energy, and strong Coulomb interactions, non-Fermi liquid behaviour is predicted, for which we observe some evidence. Our discovery implies that Pr2Ir2O7 is a parent state that can be manipulated to produce other strongly correlated topological phases, such as topological Mott insulator, Weyl semimetal, and quantum spin and anomalous Hall states.
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BACKGROUND: A small accessory facet with articular surface morphology is occasionally seen on the talus, bordering on the lateral end of the sinus tarsi. This facet has been named the accessory anterolateral talar facet. However, few anatomical studies have addressed this facet. Here we present the precise morphology of accessory anterolateral talar facet with emphasis on anatomical correlation between the presence of this facet and the angle of the infero-lateral surface of the talus (talar infero-lateral surface - TILS angle). MATERIALS AND METHODS: A total of 22 (11 male, 11 female) adult cadavers with no known pathological conditions in the talocalcaneal joints were examined during educational dissection at Nagoya City University Medical School in 2013. After exclusion of 1 joint due to the poor condition of the talus, 43 talus (22 right, 21 left) were analysed. We judged the presence of the accessory anterolateral talar facet and measured TILS angle. We performed statistical analysis on the point of laterality, gender difference and the difference in the TILS angles in tali with or without the accessory anterolateral talar facets. RESULTS: An accessory anterolateral talar facet was identified in 11 (26%) of the 43 specimens. Of the 21 cadavers with paired talar specimens, 5 displayed the facet bilaterally. CONCLUSIONS: There was no sex difference and no significant laterality, however we found that TILS angle was significantly larger in accessory anterolateral talar facet positive samples than in negative ones.
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Approximately 20% of Beckwith-Wiedemann syndrome (BWS) cases are caused by mosaic paternal uniparental disomy of chromosome 11 (pUPD11). Although pUPD11 is usually limited to the short arm of chromosome 11, a small minority of BWS cases show genome-wide mosaic pUPD (GWpUPD). These patients show variable clinical features depending on mosaic ratio, imprinting status of other chromosomes, and paternally inherited recessive mutations. To date, there have been no reports of a mosaic GWpUPD patient with an autosomal recessive disease caused by a paternally inherited recessive mutation. Here, we describe a patient concurrently showing the clinical features of BWS and autosomal recessive cystinuria. Genetic analyses revealed that the patient has mosaic GWpUPD and an inherited paternal homozygous mutation in SLC7A9. This is the first report indicating that a paternally inherited recessive mutation can cause an autosomal recessive disease in cases of GWpUPD mosaicism. Investigation into recessive mutations and the dysregulation of imprinting domains is critical in understanding precise clinical conditions of patients with mosaic GWpUPD.