Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
2.
Phys Rev Lett ; 132(13): 136402, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38613311

RESUMEN

We investigate the electronic structure of 2H-NbS_{2} and h-BN by angle-resolved photoemission spectroscopy (ARPES) and photoemission intensity calculations. Although in bulk form, these materials are expected to exhibit band degeneracy in the k_{z}=π/c plane due to screw rotation and time-reversal symmetries, we observe gapped band dispersion near the surface. We extract from first-principles calculations the near-surface electronic structure probed by ARPES and find that the calculated photoemission spectra from the near-surface region reproduce the gapped ARPES spectra. Our results show that the near-surface electronic structure can be qualitatively different from the bulk electronic structure due to partially broken nonsymmorphic symmetries.

4.
Artículo en Inglés | MEDLINE | ID: mdl-38439523

RESUMEN

Tietz albinism-deafness syndrome (TADS) is a rare and severe manifestation of Waardenburg syndrome that is primarily linked to mutations in MITF. In this report, we present a case of TADS resulting from a novel c.637G>C mutation in MITF (p.Glu213Gln; GenBank Accession number: NM_000248). A 3-year-old girl presented with congenital generalized hypopigmentation of the hair, skin, and irides along with complete sensorineural hearing loss. Histopathological and electron microscopy investigations indicated that this variant did not alter the number of melanocytes in the skin but significantly impaired melanosome maturation within melanocytes. Comprehensive melanin analysis revealed marked reductions in both eumelanin (EM) and pheomelanin (PM) rather than changes in the EM-to-PM ratio observed in oculocutaneous albinism. We conducted an electrophoretic mobility shift assay to investigate the binding capability of the identified variant to DNA sequences containing the E-box motif along with other known variants (p.Arg217del and p.Glu213Asp). Remarkably, all three variants exhibited dominant-negative effects, thus providing novel insights into the pathogenesis of TADS. This study sheds light on the genetic mechanisms underlying TADS and offers a deeper understanding of this rare condition and its associated mutations in MITF.

8.
Biomedicines ; 11(5)2023 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-37239117

RESUMEN

Studies evaluating xanthine oxidoreductase (XOR) activities in comprehensive liver diseases are scarce, and different etiologies have previously been combined in groups for comparison. To accurately evaluate XOR activities in liver diseases, the plasma XOR activities in etiology-based comprehensive liver diseases were measured using a novel, sensitive, and accurate assay that is a combination of liquid chromatography and triple quadrupole mass spectrometry to detect [13C2, 15N2]uric acid using [13C2, 15N2]xanthine as a substrate. We also mainly evaluated the association between the plasma XOR activities and parameters of liver tests, purine metabolism-associated markers, oxidative stress markers, and an inflammation marker. In total, 329 patients and 32 controls were enrolled in our study. Plasma XOR activities were generally increased in liver diseases, especially in the active phase, such as in patients with hepatitis C virus RNA positivity, those with abnormal alanine transaminase (ALT) levels in autoimmune liver diseases, and uncured hepatocellular carcinoma patients. Plasma XOR activities were numerically highest in patients with acute hepatitis B. Plasma XOR activities were closely correlated with parameters of liver tests, especially serum ALT levels, regardless of etiology and plasma xanthine levels. Our results indicated that plasma XOR activity might reflect the active phase in various liver diseases.

9.
Phys Rev Lett ; 130(18): 186402, 2023 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-37204880

RESUMEN

We study the electronic structure of the ferromagnetic spinel HgCr_{2}Se_{4} by soft-x-ray angle-resolved photoemission spectroscopy (SX-ARPES) and first-principles calculations. While a theoretical study has predicted that this material is a magnetic Weyl semimetal, SX-ARPES measurements give direct evidence for a semiconducting state in the ferromagnetic phase. Band calculations based on the density functional theory with hybrid functionals reproduce the experimentally determined band gap value, and the calculated band dispersion matches well with ARPES experiments. We conclude that the theoretical prediction of a Weyl semimetal state in HgCr_{2}Se_{4} underestimates the band gap, and this material is a ferromagnetic semiconductor.

10.
Nat Commun ; 14(1): 1945, 2023 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-37029104

RESUMEN

In crystalline materials, electron-phonon coupling (EPC) is a ubiquitous many-body interaction that drives conventional Bardeen-Cooper-Schrieffer superconductivity. Recently, in a new kagome metal CsV3Sb5, superconductivity that possibly intertwines with time-reversal and spatial symmetry-breaking orders is observed. Density functional theory calculations predicted weak EPC strength, λ, supporting an unconventional pairing mechanism in CsV3Sb5. However, experimental determination of λ is still missing, hindering a microscopic understanding of the intertwined ground state of CsV3Sb5. Here, using 7-eV laser-based angle-resolved photoemission spectroscopy and Eliashberg function analysis, we determine an intermediate λ=0.45-0.6 at T = 6 K for both Sb 5p and V 3d electronic bands, which can support a conventional superconducting transition temperature on the same magnitude of experimental value in CsV3Sb5. Remarkably, the EPC on the V 3d-band enhances to λ~0.75 as the superconducting transition temperature elevated to 4.4 K in Cs(V0.93Nb0.07)3Sb5. Our results provide an important clue to understand the pairing mechanism in the kagome superconductor CsV3Sb5.

11.
Ann Thorac Surg ; 115(4): e97-e99, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-35378088

RESUMEN

A single coronary artery with a single ostium from sinus 2 (2 R L Cx) is rare and difficult to transfer. A 6-day-old male neonate was diagnosed with dextro-transposition of the great arteries with an intact ventricular septum at birth. Computed tomography revealed the presence of a single coronary artery with a single ostium from sinus 2 (2 R L Cx). We performed a new coronary transfer technique involving a tubular pouch using the original aortic tissue for this single coronary artery. The postoperative course was uneventful, and postoperative computed tomography revealed a smooth coronary route with no stenosis.


Asunto(s)
Anomalías de los Vasos Coronarios , Transposición de los Grandes Vasos , Tabique Interventricular , Recién Nacido , Humanos , Masculino , Transposición de los Grandes Vasos/diagnóstico por imagen , Transposición de los Grandes Vasos/cirugía , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/cirugía , Constricción Patológica , Anomalías de los Vasos Coronarios/diagnóstico por imagen , Anomalías de los Vasos Coronarios/cirugía , Angiografía Coronaria
12.
J Card Surg ; 37(12): 4797-4802, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36335627

RESUMEN

BACKGROUND AND AIM: Transcatheter device closure has become the first treatment option for atrial septal defects (ASD). Surgical ASD closure, although still implemented, is cosmetically inferior to transcatheter closure. This study aimed to evaluate the feasibility as well as short- and long-term clinical outcomes of the right posterolateral minithoracotomy approach for surgical ASD closure. METHODS: In total, 102 consecutive patients underwent posterolateral minithoracotomy for ASD between January 2014 and December 2021 at our center. Early surgical outcomes, cosmetic findings, and skin perception were evaluated over 1 year of postoperative follow-up using a self-satisfaction survey (1: very good, 2: good, 3: normal, 4: not good, 5: bad), Cavendish score, and shoulder joint function (angles of flexion, extension, and abduction). RESULTS: No patient required conversion to median sternotomy. Only one patient required reoperation due to bleeding. Postoperative echocardiography revealed no residual shunt at discharge in all patients. The mean follow-up period was 3.7 years (range: 0.3-7.1 years), during which the questionnaire was answered by 69 of 98 patients who were evaluated after more than 1 year. The mean self-satisfaction survey scores for cosmetic findings and skin perception were 1.3 ± 0.6 and 1.2 ± 0.5, respectively. The Cavendish score was under Grade 1 in all patients. Shoulder flexion and abduction were normal at 180° in all patients, except one, while extension was normal at 50° in all patients, except three. CONCLUSIONS: Our procedure achieved not only good early surgical outcomes but also excellent long-term cosmetic and shoulder function results.


Asunto(s)
Defectos del Tabique Interatrial , Hombro , Humanos , Resultado del Tratamiento , Estudios Retrospectivos , Hombro/cirugía , Toracotomía/métodos , Defectos del Tabique Interatrial/cirugía , Cateterismo Cardíaco/métodos
14.
Asian Cardiovasc Thorac Ann ; 30(6): 726-728, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34747227

RESUMEN

Re-Norwood operation is technically difficult to perform and is a high risk procedure due to the underlying hypocardiac function. Herein, we describe our successful re-Norwood operation approach in a 6-month old infant with persistent severe cyanosis and aortic re-coarctation. Our procedure was performed using femoral artery cannulation to protect cerebrospinal and lower body perfusion. Safe reopening of the chest was achieved, despite strong adhesions due to prior surgeries. Our repair and anastomosis techniques are described in detail. Cardiac circulation and function improved post-surgery. The patient was maintained on anti-heart failure drug therapy after surgery while awaiting a Glenn procedure.


Asunto(s)
Coartación Aórtica , Síndrome del Corazón Izquierdo Hipoplásico , Procedimientos de Norwood , Coartación Aórtica/cirugía , Cateterismo , Arteria Femoral/diagnóstico por imagen , Arteria Femoral/cirugía , Humanos , Síndrome del Corazón Izquierdo Hipoplásico/cirugía , Lactante , Resultado del Tratamiento
16.
J Card Surg ; 36(9): 3078-3084, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34080233

RESUMEN

BACKGROUND: The high incidence of postoperative pulmonary venous obstruction (PVO) is a major mortality-associated concern in patients with right atrial isomerism and extracardiac total anomalous pulmonary venous connection (TAPVC). We evaluated new anatomical risk factors for reducing the space behind the heart after TAPVC repair. METHODS: Eighteen patients who underwent TAPVC repair between 2014 and 2020 were enrolled. Sutureless technique was used in 12 patients and conventional repair in six patients. The angle between the line perpendicular to the vertebral body and that from the vertebral body to the apex was defined as the "vertebral-apex angle (V-A angle)." The ratio of postoperative and preoperative angles, indicating the apex's lateral rotation, was compared between patients with and without PVO. RESULTS: The median (interquartile range) age and body weight at repair were 102 (79-176) days and 3.8 (2.6-4.8) kg, respectively. The 1-year survival rate was 83% (median follow-up, 29 [11-36] months). PVO occurred in seven patients (39%), who showed an obstruction of one or two branches in the apex side. The postoperative V-A angle (46° [45°-50°] vs. 36° [29°-38°], p = 0.001) and the ratio of postoperative and preoperative V-A angles (1.27 [1.24-1.42] vs. 1.03 [0.98-1.07], p = 0.001) were significantly higher in the PVO group than in the non-PVO group. The cut-off values of the postoperative V-A angle and ratio were 41° and 1.17, respectively. CONCLUSION: A postoperative rotation of the heart apex into the ipsilateral thorax was a risk factor for branch PVO after TAPVC repair.


Asunto(s)
Venas Pulmonares , Enfermedad Veno-Oclusiva Pulmonar , Síndrome de Cimitarra , Humanos , Lactante , Estudios Retrospectivos , Factores de Riesgo , Rotación , Síndrome de Cimitarra/diagnóstico por imagen , Síndrome de Cimitarra/cirugía , Resultado del Tratamiento
17.
Nat Mater ; 20(8): 1093-1099, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34017119

RESUMEN

Control of the phase transition from topological to normal insulators can allow for an on/off switching of spin current. While topological phase transitions have been realized by elemental substitution in semiconducting alloys, such an approach requires preparation of materials with various compositions. Thus it is quite far from a feasible device application, which demands a reversible operation. Here we use angle-resolved photoemission spectroscopy and spin- and angle-resolved photoemission spectroscopy to visualize the strain-driven band-structure evolution of the quasi-one-dimensional superconductor TaSe3. We demonstrate that it undergoes reversible strain-induced topological phase transitions from a strong topological insulator phase with spin-polarized, quasi-one-dimensional topological surface states, to topologically trivial semimetal and band insulating phases. The quasi-one-dimensional superconductor TaSe3 provides a suitable platform for engineering the topological spintronics, for example as an on/off switch for a spin current that is robust against impurity scattering.

18.
Graefes Arch Clin Exp Ophthalmol ; 259(8): 2175-2180, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33625563

RESUMEN

PURPOSE: To assess the vascular pattern of choroidal vortex veins at the horizontal watershed zone in normal eyes using optical coherence tomography (OCT). METHODS: We retrospectively studied 207 normal eyes of 207 patients whose fellow eyes were diagnosed with unilateral retinal diseases without choroidal involvement. Venous anastomosis between the superior and inferior vortex veins and deviation of the horizontal watershed zone were evaluated using 12 × 12-mm en face OCT images. Central choroidal thickness (CCT) was measured on B-mode OCT images. RESULTS: Vortex vein anastomosis was observed in 92 eyes (44.4%) at the horizontal watershed zone. Superior or inferior deviation of the horizontal watershed was ascertained in 69 eyes (33.3%). The frequency of the anastomosis and deviation did not differ significantly between age groups (P = 0.56 and 0.96, respectively). Mean CCT of all eyes was 221 ± 80 µm. CCT was significantly greater in eyes with anastomosis than in those without (233 ± 73 µm vs 210 ± 83 µm, P < 0.05). However, CCT did not differ significantly between eyes with and without deviation of the horizontal watershed zone (223 ± 74 µm vs 219 ± 82 µm). CONCLUSIONS: Venous anastomosis at the horizontal watershed zone as well as superior or inferior deviation of the zone were frequently observed in normal eyes. CCT was greater in eyes with than in those without anastomosis, suggesting subclinical vortex vein congestion.


Asunto(s)
Coroides , Tomografía de Coherencia Óptica , Angiografía con Fluoresceína , Humanos , Estudios Retrospectivos
19.
Oncology ; 99(4): 203-214, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33279908

RESUMEN

AIM: The aim of this retrospective study was to investigate the efficacy and safety of ramucirumab treatment under real-world conditions and to clarify the role of albumin-bilirubin (ALBI) score in predicting outcomes. METHODS: Between June 2019 and May 2020, a total of 16 patients with advanced hepatocellular carcinoma (HCC) treated with ramucirumab in Gunma Saiseikai Maebashi Hospital and its affiliated hospitals was included. RESULTS: The median age was 71 (interquartile range [IQR] 65-74) years old, and 12 patients (75.0%) were male. The modified ALBI (mALBI) grade was 1, 2a, and 2b at baseline in 4 (25.0%), 3 (18.8%), and 9 patients (56.3%), respectively. The Barcelona Clinic Liver Cancer stage was intermediate and advanced stage in 1 (6.3%) and 15 patients (93.8%), respectively. The serum α-fetoprotein at baseline was 4,911 (IQR 2,091-17,377) ng/mL. The disease control rate in patients with mALBI grade1 + 2a was significantly higher than in those with mALBI grade 2b (100 vs. 28.6%, p = 0.028). The patients with mALBI grade 1 + 2a had a significantly better overall survival (OS) and longer progression-free survival (PFS) than those with mALBI grade 2b (median OS 6.7 vs. 3.0 months; p = 0.036, median PFS 7.5 vs. 1.4 months; p = 0.002). The number of cycles of ramucirumab treatment was significantly correlated with the ALBI score (r = -0.452, p = 0.030). The patients with mALBI grade 1 + 2a showed a low incidence of adverse events (AEs) and discontinuation due to AEs. CONCLUSIONS: Advanced HCC patients with mALBI grade 1 + 2a may be a good indication for ramucirumab treatment.


Asunto(s)
Anticuerpos Monoclonales Humanizados/efectos adversos , Antineoplásicos/efectos adversos , Bilirrubina/sangre , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Albúmina Sérica Humana/análisis , Anciano , Carcinoma Hepatocelular/sangre , Carcinoma Hepatocelular/epidemiología , Carcinoma Hepatocelular/patología , Femenino , Humanos , Japón/epidemiología , Pruebas de Función Hepática , Neoplasias Hepáticas/sangre , Neoplasias Hepáticas/epidemiología , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Supervivencia sin Progresión , Estudios Retrospectivos , alfa-Fetoproteínas/análisis , Ramucirumab
20.
Sci Rep ; 10(1): 19505, 2020 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-33177540

RESUMEN

Pachychoroid spectrum diseases have attracted increasing attention, though their pathophysiology has yet to be fully elucidated. In this study, we assessed the vascular diameters of vortex veins in pachychoroid spectrum diseases such as central serous chorioretinopathy (CSC), pachychoroid neovasculopathy without polypoidal lesions (PNV), and pachychoroid neovasculopathy with polypoidal lesions (polypoidal choroidal vasculopathy: PCV). In a retrospective case series of 94 eyes with CSC, 60 eyes with PNV and 57 with PCV, we binarized en face optical coherence tomography (OCT) images of choroidal vortex veins and analyzed the mean diameter of vortex veins. The presence of anastomosis between the superior and inferior vortex veins and central choroidal thickness (CCT) were also evaluated using OCT images. CSC showed significantly larger mean diameter of vortex veins than PCV (P < 0.05). Anastomosis between superior and inferior vortex veins was observed in over 90% of eyes with each pachychoroid spectrum disease. The patients with CSC were the youngest, followed by PNV patients, and then patients with PCV. The largest CCT values were observed in CSC eyes, followed by PNV eyes, and then PCV eyes. CCT correlated with the mean diameter of vortex veins (rs = 0.51, P < 0.01). These findings suggest that congestion of vortex veins might show gradual amelioration corresponding to the development of anastomosis between the superior and inferior vortex veins during the course of progression of pachychoroid spectrum diseases. Moreover, the mean diameter of vortex veins can be used as a parameter indicating choroidal congestion.


Asunto(s)
Coriorretinopatía Serosa Central/diagnóstico por imagen , Coriorretinopatía Serosa Central/patología , Enfermedades de la Coroides/diagnóstico por imagen , Coroides/irrigación sanguínea , Coroides/diagnóstico por imagen , Vena Retiniana/diagnóstico por imagen , Adulto , Anciano , Coriorretinopatía Serosa Central/complicaciones , Coroides/patología , Enfermedades de la Coroides/complicaciones , Enfermedades de la Coroides/patología , Neovascularización Coroidal/diagnóstico por imagen , Neovascularización Coroidal/patología , Progresión de la Enfermedad , Femenino , Angiografía con Fluoresceína , Fondo de Ojo , Humanos , Masculino , Persona de Mediana Edad , Segmento Posterior del Ojo/irrigación sanguínea , Segmento Posterior del Ojo/diagnóstico por imagen , Desprendimiento de Retina/diagnóstico por imagen , Desprendimiento de Retina/patología , Epitelio Pigmentado de la Retina/diagnóstico por imagen , Epitelio Pigmentado de la Retina/patología , Vena Retiniana/patología , Estudios Retrospectivos , Tomografía de Coherencia Óptica
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...