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1.
NPJ Quantum Mater ; 8(1): 7, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38666240

RESUMO

In high-temperature cuprate superconductors, stripe order refers broadly to a coupled spin and charge modulation with a commensuration of eight and four lattice units, respectively. How this stripe order evolves across optimal doping remains a controversial question. Here we present a systematic resonant inelastic x-ray scattering study of weak charge correlations in La2-xSrxCuO4 and La1.8-xEu0.2SrxCuO4. Ultra high energy resolution experiments demonstrate the importance of the separation of inelastic and elastic scattering processes. Long-range temperature-dependent stripe order is only found below optimal doping. At higher doping, short-range temperature-independent correlations are present up to the highest doping measured. This transformation is distinct from and preempts the pseudogap critical doping. We argue that the doping and temperature-independent short-range correlations originate from unresolved electron-phonon coupling that broadly peaks at the stripe ordering vector. In La2-xSrxCuO4, long-range static stripe order vanishes around optimal doping and we discuss both quantum critical and crossover scenarios.

2.
Phys Rev Lett ; 127(22): 227201, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34889637

RESUMO

Spin-orbit Mott insulators composed of t_{2g}^{4} transition metal ions may host excitonic magnetism due to the condensation of spin-orbital J=1 triplons. Prior experiments suggest that the 4d antiferromagnet Ca_{2}RuO_{4} embodies this notion, but a J=0 nonmagnetic state as a basis of the excitonic picture remains to be confirmed. We use Ru L_{3}-edge resonant inelastic x-ray scattering to reveal archetypal J multiplets with a J=0 ground state in the cubic compound K_{2}RuCl_{6}, which are well described within the LS-coupling scheme. This result highlights the critical role of unquenched orbital moments in 4d-electron compounds and calls for investigations of quantum criticality and excitonic magnetism on various crystal lattices.

3.
Br J Surg ; 108(4): 412-418, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33793713

RESUMO

BACKGROUND: Surgical treatment for hepatocellular carcinoma (HCC) is advancing, but a robust prediction model for survival after resection is not available. The aim of this study was to propose a prognostic grading system for resection of HCC. METHODS: This was a retrospective, multicentre study of patients who underwent first resection of HCC with curative intent between 2000 and 2007. Patients were divided randomly by a cross-validation method into training and validation sets. Prognostic factors were identified using a Cox proportional hazards model. The predictive model was built by decision-tree analysis to define the resection grades, and subsequently validated. RESULTS: A total of 16 931 patients from 795 hospitals were included. In the training set (8465 patients), four surgical grades were classified based on prognosis: grade A1 (1236 patients, 14.6 per cent; single tumour 3 cm or smaller and anatomical R0 resection); grade A2 (3614, 42.7 per cent; single tumour larger than 3 cm, or non-anatomical R0 resection); grade B (2277, 26.9 per cent; multiple tumours, or vascular invasion, and R0 resection); and grade C (1338, 15.8 per cent; multiple tumours with vascular invasion and R0 resection, or R1 resection). Five-year survival rates were 73.9 per cent (hazard ratio (HR) 1.00), 64.7 per cent (HR 1.51, 95 per cent c.i. 1.29 to 1.78), 50.6 per cent (HR 2.53, 2.15 to 2.98), and 34.8 per cent (HR 4.60, 3.90 to 5.42) for grades A1, A2, B, and C respectively. In the validation set (8466 patients), the grades had equivalent reproducibility for both overall and recurrence-free survival (all P < 0.001). CONCLUSION: This grade is used to predict prognosis of patients undergoing resection of HCC.


Assuntos
Carcinoma Hepatocelular/diagnóstico , Neoplasias Hepáticas/diagnóstico , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Árvores de Decisões , Feminino , Hepatectomia/métodos , Humanos , Fígado/patologia , Fígado/cirurgia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores/métodos , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida
4.
Phys Rev Lett ; 124(18): 187002, 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32441965

RESUMO

We use resonant inelastic x-ray scattering to investigate charge-stripe correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4}. By differentiating elastic from inelastic scattering, it is demonstrated that charge-stripe correlations precede both the structural low-temperature tetragonal phase and the transport-defined pseudogap onset. The scattering peak amplitude from charge stripes decays approximately as T^{-2} towards our detection limit. The in-plane integrated intensity, however, remains roughly temperature independent. Therefore, although the incommensurability shows a remarkably large increase at high temperature, our results are interpreted via a single scattering constituent. In fact, direct comparison to other stripe-ordered compounds (La_{1.875}Ba_{0.125}CuO_{4}, La_{1.475}Nd_{0.4}Sr_{0.125}CuO_{4}, and La_{1.875}Sr_{0.125}CuO_{4}) suggests a roughly constant integrated scattering intensity across all these compounds. Our results therefore provide a unifying picture for the charge-stripe ordering in La-based cuprates. As charge correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4} extend beyond the low-temperature tetragonal and pseudogap phase, their emergence heralds a spontaneous symmetry breaking in this compound.

5.
Br J Surg ; 107(1): 113-120, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31654406

RESUMO

BACKGROUND: The impact of a wide surgical margin on the outcome of patients with hepatocellular carcinoma (HCC) has not been evaluated in relation to the type of liver resection performed, anatomical or non-anatomical. The aim of this study was to evaluate the impact of surgical margin status on outcomes in patients undergoing anatomical or non-anatomical resection for solitary HCC. METHODS: Data from patients with solitary HCC who had undergone non-anatomical partial resection (Hr0 group) or anatomical resection of one Couinaud segment (HrS group) between 2000 and 2007 were extracted from a nationwide survey database in Japan. Overall and recurrence-free survival associated with the surgical margin status and width were evaluated in the two groups. RESULTS: A total of 4457 patients were included in the Hr0 group and 3507 in the HrS group. A microscopically positive surgical margin was associated with poor overall survival in both groups. A negative but 0-mm surgical margin was associated with poorer overall and recurrence-free survival than a wider margin only in the Hr0 group. In the HrS group, the width of the surgical margin was not associated with patient outcome. CONCLUSION: Anatomical resection with a negative 0-mm surgical margin may be acceptable. Non-anatomical resection with a negative 0-mm margin was associated with a less favourable survival outcome.


ANTECEDENTES: El impacto de un margen quirúrgico (surgical margin, SM) amplio en el resultado de pacientes con carcinoma hepatocelular (hepatocellular carcinoma, HCC) no ha sido evaluado en relación con el tipo de resección hepática realizada: anatómica o no anatómica. El objetivo del presente estudio fue evaluar el impacto del estado del SM en los resultados en pacientes sometidos a resección anatómica o no anatómica por un HCC solitario. MÉTODOS: Los datos de pacientes con un HCC solitario sometidos a resección parcial no anatómica (grupo Hr0) o resección anatómica de un segmento de Couinaud (grupo HrS) entre 2000 y 2007 se obtuvieron a partir de una base de datos nacional de Japón. En los grupos Hr0 y HrS se evaluaron la supervivencia global y la supervivencia libre de recidiva asociadas al estado microscópico del SM y a la amplitud del SM. RESULTADOS: Se incluyeron un total de 4.457 pacientes en el grupo Hr0 y 3.507 en el grupo HrS. Un SM microscópico positivo se asoció con una pobre supervivencia global en ambos grupos. Un SM negativo, pero a una distancia de 0 mm se asoció con una peor supervivencia global y libre de recidiva en comparación con aquellos asociados a un SM más amplio, solo en el grupo Hr0. En el grupo HrS, la amplitud del SM no se asoció con los resultados del paciente. CONCLUSIÓN: La resección anatómica con un SM negativo a una distancia de 0 mm puede ser aceptable. La resección no anatómica con un SM negativo a una distancia de 0 mm se asoció con resultados de supervivencia menos favorables.


Assuntos
Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/cirurgia , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Intervalo Livre de Doença , Humanos , Japão/epidemiologia , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Margens de Excisão , Estudos Prospectivos , Carga Tumoral
7.
Nature ; 571(7765): 376-380, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31316196

RESUMO

The nature of the pseudogap phase of the copper oxides ('cuprates') remains a puzzle. Although there are indications that this phase breaks various symmetries, there is no consensus on its fundamental nature1. Fermi-surface, transport and thermodynamic signatures of the pseudogap phase are reminiscent of a transition into a phase with antiferromagnetic order, but evidence for an associated long-range magnetic order is still lacking2. Here we report measurements of the thermal Hall conductivity (in the x-y plane, κxy) in the normal state of four different cuprates-La1.6-xNd0.4SrxCuO4, La1.8-xEu0.2SrxCuO4, La2-xSrxCuO4 and Bi2Sr2-xLaxCuO6+δ. We show that a large negative κxy signal is a property of the pseudogap phase, appearing at its critical hole doping, p*. It is also a property of the Mott insulator at p ≈ 0, where κxy has the largest reported magnitude of any insulator so far3. Because this negative κxy signal grows as the system becomes increasingly insulating electrically, it cannot be attributed to conventional mobile charge carriers. Nor is it due to magnons, because it exists in the absence of magnetic order. Our observation is reminiscent of the thermal Hall conductivity of insulators with spin-liquid states4-6, pointing to neutral excitations with spin chirality7 in the pseudogap phase of cuprates.

8.
Nature ; 567(7747): 218-222, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30760922

RESUMO

The three central phenomena of cuprate (copper oxide) superconductors are linked by a common doping level p*-at which the enigmatic pseudogap phase ends and the resistivity exhibits an anomalous linear dependence on temperature, and around which the superconducting phase forms a dome-shaped area in the phase diagram1. However, the fundamental nature of p* remains unclear, in particular regarding whether it marks a true quantum phase transition. Here we measure the specific heat C of the cuprates Eu-LSCO and Nd-LSCO at low temperature in magnetic fields large enough to suppress superconductivity, over a wide doping range2 that includes p*. As a function of doping, we find that Cel/T is strongly peaked at p* (where Cel is the electronic contribution to C) and exhibits a log(1/T) dependence as temperature T tends to zero. These are the classic thermodynamic signatures of a quantum critical point3-5, as observed in heavy-fermion6 and iron-based7 superconductors at the point where their antiferromagnetic phase comes to an end. We conclude that the pseudogap phase of cuprates ends at a quantum critical point, the associated fluctuations of which are probably involved in d-wave pairing and the anomalous scattering of charge carriers.

9.
J Phys Condens Matter ; 31(7): 074001, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30523949

RESUMO

SrIrO3 crystallizes in a monoclinic structure of distorted hexagonal perovskite at ambient pressure. The transport measurements show that the monoclinic SrIrO3 is a low-carrier density semimetal, as in the orthorhombic perovskite polymorph. The electronic structure calculation indicates a semimetallic band structure with Dirac bands at two high-symmetry points of Brillouin zone only when spin-orbit coupling is incorporated, suggesting that the semimetallic state is produced by the strong spin-orbit coupling. We argue that the Dirac bands are protected by the non-symmorphic symmetry of lattice.

10.
Phys Rev Lett ; 121(7): 077004, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-30169083

RESUMO

We present a soft x-ray angle-resolved photoemission spectroscopy study of overdoped high-temperature superconductors. In-plane and out-of-plane components of the Fermi surface are mapped by varying the photoemission angle and the incident photon energy. No k_{z} dispersion is observed along the nodal direction, whereas a significant antinodal k_{z} dispersion is identified for La-based cuprates. Based on a tight-binding parametrization, we discuss the implications for the density of states near the van Hove singularity. Our results suggest that the large electronic specific heat found in overdoped La_{2-x}Sr_{x}CuO_{4} cannot be assigned to the van Hove singularity alone. We therefore propose quantum criticality induced by a collapsing pseudogap phase as a plausible explanation for observed enhancement of electronic specific heat.

11.
Transplant Proc ; 50(4): 1074-1076, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29731068

RESUMO

BACKGROUND: Immunocomplex capture fluorescence analysis (ICFA) detects donor-specific antihuman leukocyte antigen (HLA) antibodies (DSA), but the detection sensitivity of HLA class II antibodies using conventional ICFA is as low as 57%. The aim of the study was to improve the detection sensitivity of HLA class II antibodies by ICFA, and compare the ICFA results with the Luminex single-antigen bead test. METHODS: Six DSA-negative kidney transplant donors and recipient pairs and 10 HLA class II DSA-positive pairs were included in the study. The detection sensitivity of modified ICFA was compared with conventional ICFA, and the ICFA results were compared with the Luminex single-antigen bead test. RESULTS: The index value of modified ICFA was higher than that of conventional ICFA. The cutoff value of conventional ICFA was 30,686 (MFI), which was improved to 19,405 using modified ICFA. Regarding the HLA-DQ antibody, 5 samples found to be positive by Luminex single-antigen bead testing were all negative using modified ICFA. The reason for this discrepancy could be related to: (1) the difference in detection sensitivity; (2) the difference in HLA antigen surface expression between naive lymphocytes and synthetic beads; or (3) the structure of synthetic HLA DQ antigen on the Luminex single-antigen beads. CONCLUSION: The index value of the modified ICFA was higher than that of conventional ICFA, and the detection sensitivity of HLA class II antibodies was improved by modified ICFA. Further assessment is necessary to clarify the reasons for divergence between ICFA and Luminex single-antigen bead test results.


Assuntos
Antígenos de Histocompatibilidade Classe II/imunologia , Teste de Histocompatibilidade/métodos , Imunoensaio/métodos , Transplante de Rim , Adulto , Anticorpos/imunologia , Feminino , Imunofluorescência/métodos , Rejeição de Enxerto/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Doadores de Tecidos
12.
Nat Commun ; 9(1): 972, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29511188

RESUMO

The minimal ingredients to explain the essential physics of layered copper-oxide (cuprates) materials remains heavily debated. Effective low-energy single-band models of the copper-oxygen orbitals are widely used because there exists no strong experimental evidence supporting multi-band structures. Here, we report angle-resolved photoelectron spectroscopy experiments on La-based cuprates that provide direct observation of a two-band structure. This electronic structure, qualitatively consistent with density functional theory, is parametrised by a two-orbital ([Formula: see text] and [Formula: see text]) tight-binding model. We quantify the orbital hybridisation which provides an explanation for the Fermi surface topology and the proximity of the van-Hove singularity to the Fermi level. Our analysis leads to a unification of electronic hopping parameters for single-layer cuprates and we conclude that hybridisation, restraining d-wave pairing, is an important optimisation element for superconductivity.

13.
Nature ; 554(7692): 341-345, 2018 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-29446382

RESUMO

The honeycomb lattice is one of the simplest lattice structures. Electrons and spins on this simple lattice, however, often form exotic phases with non-trivial excitations. Massless Dirac fermions can emerge out of itinerant electrons, as demonstrated experimentally in graphene, and a topological quantum spin liquid with exotic quasiparticles can be realized in spin-1/2 magnets, as proposed theoretically in the Kitaev model. The quantum spin liquid is a long-sought exotic state of matter, in which interacting spins remain quantum-disordered without spontaneous symmetry breaking. The Kitaev model describes one example of a quantum spin liquid, and can be solved exactly by introducing two types of Majorana fermion. Realizing a Kitaev model in the laboratory, however, remains a challenge in materials science. Mott insulators with a honeycomb lattice of spin-orbital-entangled pseudospin-1/2 moments have been proposed, including the 5d-electron systems α-Na2IrO3 (ref. 5) and α-Li2IrO3 (ref. 6) and the 4d-electron system α-RuCl3 (ref. 7). However, these candidates were found to magnetically order rather than form a liquid at sufficiently low temperatures, owing to non-Kitaev interactions. Here we report a quantum-liquid state of pseudospin-1/2 moments in the 5d-electron honeycomb compound H3LiIr2O6. This iridate does not display magnetic ordering down to 0.05 kelvin, despite an interaction energy of about 100 kelvin. We observe signatures of low-energy fermionic excitations that originate from a small number of spin defects in the nuclear-magnetic-resonance relaxation and the specific heat. We therefore conclude that H3LiIr2O6 is a quantum spin liquid. This result opens the door to finding exotic quasiparticles in a strongly spin-orbit-coupled 5d-electron transition-metal oxide.

14.
Nat Commun ; 8: 14408, 2017 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-28205553

RESUMO

The excitonic insulator is a long conjectured correlated electron phase of narrow-gap semiconductors and semimetals, driven by weakly screened electron-hole interactions. Having been proposed more than 50 years ago, conclusive experimental evidence for its existence remains elusive. Ta2NiSe5 is a narrow-gap semiconductor with a small one-electron bandgap EG of <50 meV. Below TC=326 K, a putative excitonic insulator is stabilized. Here we report an optical excitation gap Eop ∼0.16 eV below TC comparable to the estimated exciton binding energy EB. Specific heat measurements show the entropy associated with the transition being consistent with a primarily electronic origin. To further explore this physics, we map the TC-EG phase diagram tuning EG via chemical and physical pressure. The dome-like behaviour around EG∼0 combined with our transport, thermodynamic and optical results are fully consistent with an excitonic insulator phase in Ta2NiSe5.

15.
Br J Surg ; 103(13): 1795-1803, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27682642

RESUMO

BACKGROUND: Previous RCTs have failed to demonstrate the usefulness of combining energy devices with the conventional clamp crushing method to reduce blood loss during liver transection. Here, the combination of an ultrasonically activated device (UAD) and a bipolar vessel-sealing device (BVSD) with crush clamping was investigated. METHODS: Patients scheduled to undergo hepatectomy at the University of Tokyo Hospital or Nihon University Itabashi Hospital were eligible for this parallel-group, single-blinded randomized study. Patients were assigned to a control group (no energy device used), an UAD group or a BVSD group. The primary endpoint was the volume of blood loss during liver transection. Outcomes of the control group and the combined energy device groups (UAD plus BVSD) were first compared. Pairwise comparisons among the three groups were made for outcomes for which the combined energy device group was superior to the control group. RESULTS: A total of 380 patients were enrolled between July 2012 and May 2014; 116 patients in the control group, 122 in the UAD group and 123 in the BVSD group were included in the final analysis. Median blood loss during liver transection was lower in the combined energy device group (245 patients) than in the control group (116 patients): median 190 (range 0-3575) versus 230 (range 3-1570) ml (P = 0·048). Pairwise comparison revealed that blood loss was lower in the BVSD group than in the control group (P = 0·043). CONCLUSION: The use of energy devices combined with crush clamping reduced blood loss during liver transection. Registration number: C000008372 (www.umin.ac.jp/ctr/index.htm).


Assuntos
Hemostasia Cirúrgica/instrumentação , Hepatectomia/instrumentação , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Perda Sanguínea Cirúrgica/prevenção & controle , Constrição , Feminino , Hemostasia Cirúrgica/métodos , Hepatectomia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Instrumentos Cirúrgicos , Resultado do Tratamento
16.
J Clin Pharm Ther ; 41(6): 725-726, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27624676

RESUMO

WHAT IS KNOWN AND OBJECTIVE: There have been several reports describing rectovaginal fistula development after bevacizumab treatment, and these fistulas were diagnosed by CT scan or colonoscopy. We report a case of sigmoid-vaginal fistula diagnosed by fistulography. CASE DESCRIPTION: The case is a 53-year-old woman who was treated for chronic myelogenous leukaemia and gynaecological cancers 8 years previously. At 52 years of age, she was diagnosed with colon cancer and had a partial colectomy performed. One year after surgery, colon cancer recurred, and she was treated with anticancer agents, including bevacizumab. During chemotherapy, she complained of a foul smelling discharge from the vagina. Fistulography revealed a sigmoid-vaginal fistula. WHAT IS NEW AND CONCLUSION: This is the first report of vaginal fistulography performed on a patient who was treated with bevacizumab. Fistulography may be useful for detecting sigmoid-vaginal fistula.


Assuntos
Inibidores da Angiogênese/efeitos adversos , Bevacizumab/efeitos adversos , Colo Sigmoide/efeitos dos fármacos , Fístula Vaginal/induzido quimicamente , Inibidores da Angiogênese/uso terapêutico , Bevacizumab/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico
17.
Ann Oncol ; 27(8): 1539-46, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27177863

RESUMO

BACKGROUND: FOLFIRI and FOLFOX have shown equivalent efficacy for metastatic colorectal cancer (mCRC), but their comparative effectiveness is unknown when combined with bevacizumab. PATIENTS AND METHODS: WJOG4407G was a randomized, open-label, phase III trial conducted in Japan. Patients with previously untreated mCRC were randomized 1:1 to receive either FOLFIRI plus bevacizumab (FOLFIRI + Bev) or mFOLFOX6 plus bevacizumab (mFOLFOX6 + Bev), stratified by institution, adjuvant chemotherapy, and liver-limited disease. The primary end point was non-inferiority of FOLFIRI + Bev to mFOLFOX6 + Bev in progression-free survival (PFS), with an expected hazard ratio (HR) of 0.9 and non-inferiority margin of 1.25 (power 0.85, one-sided α-error 0.025). The secondary end points were response rate (RR), overall survival (OS), safety, and quality of life (QoL) during 18 months. This trial is registered to the University Hospital Medical Information Network, number UMIN000001396. RESULTS: Among 402 patients enrolled from September 2008 to January 2012, 395 patients were eligible for efficacy analysis. The median PFS for FOLFIRI + Bev (n = 197) and mFOLFOX6 + Bev (n = 198) were 12.1 and 10.7 months, respectively [HR, 0.905; 95% confidence interval (CI) 0.723-1.133; P = 0.003 for non-inferiority]. The median OS for FOLFIRI + Bev and mFOLFOX6 + Bev were 31.4 and 30.1 months, respectively (HR, 0.990; 95% CI 0.785-1.249). The best overall RRs were 64% for FOLFIRI + Bev and 62% for mFOLFOX6 + Bev. The common grade 3 or higher adverse events were leukopenia (11% in FOLFIRI + Bev/5% in mFOLFOX6 + Bev), neutropenia (46%/35%), diarrhea (9%/5%), febrile neutropenia (5%/2%), peripheral neuropathy (0%/22%), and venous thromboembolism (6%/2%). The QoL assessed by FACT-C (TOI-PFC) and FACT/GOG-Ntx was favorable for FOLFIRI + Bev during 18 months. CONCLUSION: FOLFIRI plus bevacizumab was non-inferior for PFS, compared with mFOLFOX6 plus bevacizumab, as the first-line systemic treatment for mCRC. CLINICAL TRIALS NUMBER: UMIN000001396.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Bevacizumab/administração & dosagem , Camptotecina/análogos & derivados , Neoplasias Colorretais/tratamento farmacológico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Bevacizumab/efeitos adversos , Camptotecina/administração & dosagem , Camptotecina/efeitos adversos , Neoplasias Colorretais/patologia , Intervalo Livre de Doença , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/classificação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Humanos , Japão , Estimativa de Kaplan-Meier , Leucovorina/administração & dosagem , Leucovorina/efeitos adversos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Compostos Organoplatínicos/administração & dosagem , Compostos Organoplatínicos/efeitos adversos , Modelos de Riscos Proporcionais , Resultado do Tratamento
18.
Eur J Vasc Endovasc Surg ; 50(6): 754-60, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26371414

RESUMO

OBJECTIVES: To assess aortic arch morphology and aortic length in patients with dissection, traumatic injury, and aneurysm undergoing TEVAR, and to identify characteristics specific to different pathologies. METHOD: This was a retrospective analysis of the aortic arch morphology and aortic length of dissection, traumatic injury, and aneurysmal patients. Computed tomography imaging was evaluated of 210 patients (49 dissection, 99 traumatic injury, 62 aneurysm) enrolled in three trials that received the conformable GORE TAG thoracic endoprosthesis. The mean age of trauma patients was 43 ± 19.6 years, 57 ± 11.7 years for dissection and 72 ± 9.6 years for aneurysm patients. A standardized protocol was used to measure aortic arch diameter, length, and take-off angle and clockface orientation of branch vessels. Differences in arch anatomy and length were assessed using ANOVA and independent t tests. RESULTS: Of the 210 arches evaluated, 22% had arch vessel common trunk configurations. The aortic diameter and the distance from the left main coronary (LMC) to the left common carotid (LCC) were greater in dissection patients than in trauma or aneurysm patients (p < .001). Aortic diameter in aneurysm patients was greater compared with trauma patients (p < .05). The distances from the branch vessels to the celiac artery (CA) were greater in dissection and aneurysm patients than in trauma patients (p < .001). The take-off angle of the innominate (I), LCCA, and left subclavian (LS) were greater, between 19% and 36%, in trauma patients than in dissection and aneurysm patients (p < .001). Clockface orientation of the arch vessels varies between pathologies. CONCLUSIONS: Arch anatomy has significant morphologic differences when comparing aortic pathologies. Describing these differences in a large sample of patients is beneficial for device designs and patient selection.


Assuntos
Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/diagnóstico por imagem , Dissecção Aórtica/diagnóstico por imagem , Aortografia/métodos , Tomografia Computadorizada por Raios X , Lesões do Sistema Vascular/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Dissecção Aórtica/cirurgia , Aorta Torácica/lesões , Aorta Torácica/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Prótese Vascular , Implante de Prótese Vascular/instrumentação , Procedimentos Endovasculares/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Desenho de Prótese , Estudos Retrospectivos , Stents , Estados Unidos , Lesões do Sistema Vascular/cirurgia , Adulto Jovem
19.
Nat Nanotechnol ; 10(12): 1043-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26389661

RESUMO

Tunable bandgaps, extraordinarily large exciton-binding energies, strong light-matter coupling and a locking of the electron spin with layer and valley pseudospins have established transition-metal dichalcogenides (TMDs) as a unique class of two-dimensional (2D) semiconductors with wide-ranging practical applications. Using angle-resolved photoemission (ARPES), we show here that doping electrons at the surface of the prototypical strong spin-orbit TMD WSe2, akin to applying a gate voltage in a transistor-type device, induces a counterintuitive lowering of the surface chemical potential concomitant with the formation of a multivalley 2D electron gas (2DEG). These measurements provide a direct spectroscopic signature of negative electronic compressibility (NEC), a result of electron-electron interactions, which we find persists to carrier densities approximately three orders of magnitude higher than in typical semiconductor 2DEGs that exhibit this effect. An accompanying tunable spin splitting of the valence bands further reveals a complex interplay between single-particle band-structure evolution and many-body interactions in electrostatically doped TMDs. Understanding and exploiting this will open up new opportunities for advanced electronic and quantum-logic devices.

20.
Phys Rev Lett ; 114(7): 077202, 2015 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-25763972

RESUMO

A complex iridium oxide ß-Li(2)IrO(3) crystallizes in a hyperhoneycomb structure, a three-dimensional analogue of honeycomb lattice, and is found to be a spin-orbital Mott insulator with J(eff)=1/2 moment. Ir ions are connected to the three neighboring Ir ions via Ir-O(2)-Ir bonding planes, which very likely gives rise to bond-dependent ferromagnetic interactions between the J(eff)=1/2 moments, an essential ingredient of Kitaev model with a spin liquid ground state. Dominant ferromagnetic interaction between J(eff)=1/2 moments is indeed confirmed by the temperature dependence of magnetic susceptibility χ(T) which shows a positive Curie-Weiss temperature θ(CW)∼+40 K. A magnetic ordering with a very small entropy change, likely associated with a noncollinear arrangement of J(eff)=1/2 moments, is observed at T(c)=38 K. With the application of magnetic field to the ordered state, a large moment of more than 0.35 µ(B)/Ir is induced above 3 T, a substantially polarized J(eff)=1/2 state. We argue that the close proximity to ferromagnetism and the presence of large fluctuations evidence that the ground state of hyperhoneycomb ß-Li(2)IrO(3) is located in close proximity of a Kitaev spin liquid.

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