Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.748
Filtrar
1.
Nano Lett ; 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39230935

RESUMEN

Two-dimensional valleys and magnetism are rising areas with intriguing properties and practical uses in advanced information technology. By coupling valleys to collinear magnetism, valley degeneracy is lifted in a large number of magnetic valley materials to exploit the valley degree of freedom. Beyond collinear magnetism, new coupling modes between valley and magnetism are few but highly desirable. By tight-binding calculations of a breathing Kagome lattice, we demonstrate a tunable valley structure and valley-contrasting physical properties in noncollinear antiferromagnets. Distinct from collinear magnetism, noncollinear antiferromagnetic order enables valley splittings even without spin-orbit coupling. Both the canting and azimuthal angles of magnetic moments can be used as experimentally accessible knobs to tune valley splittings. Our first-principles calculations of the Fe3C6O6-silicene-Fe3C6O6 heterostructure also exhibit tunable valley splittings in noncollinear antiferromagnetism, agreeing with our tight-binding results. Our work paves avenues for designing novel magnetic valley materials and energy-efficient valleytronic devices based on noncollinear magnetism.

2.
Radiol Case Rep ; 19(11): 4784-4787, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39228944

RESUMEN

Congenital absence of the internal carotid artery is a rare anatomical variant. The primarily reported origins of the ophthalmic artery associated with this variant are the posterior communicating, middle cerebral, and external carotid arteries. We report the case of a patient without an internal carotid artery whose ophthalmic artery originated from the contralateral internal carotid artery. The superior hypophyseal and prechiasmal arteries may contribute to collateral flow to the orbit from the contralateral internal carotid artery.

3.
Thorac Cancer ; 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39257073

RESUMEN

A 41 year-old female with a medical history of Turner syndrome underwent a chest computed tomography (CT) scan which revealed a varicose left pulmonary vein and an endobronchial tumor of the left lower lobe. As venous drainage of each lobe seemed to be respected, surgical resection was considered. During surgical exploration, the absence of fissure and a unique venous trunk was observed. Surgical resection was aborted as only pneumonectomy was possible in this context. Endobronchial resection was performed. To better understand this particular anatomy, a three-dimensional (3D) reconstruction was performed a posteriori. This technique is already commonly used in the preoperative planning of pulmonary segmentectomy. Here, we have shown its interest in a lung malformative context.

4.
Schizophr Bull ; 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39241740

RESUMEN

BACKGROUND: Since the late 1990s, there has been a worldwide surge of scientific interest in the pre-psychotic phase, resulting in the introduction of several clinical tools for early detection. The predictive accuracy of these tools has been limited, motivating the need for methodological and perspectival improvements. The EASE manual supports systematic assessment of anomalous self-experience, and proposes an overall model of understanding how most psychotic experiences may be initially generated on the basis of a unifying, fundamental, pre-reflective distortion of subjectivity. STUDY DESIGN: The EASE is time-consuming, so in order to spread the use of this essential perspective of psychosis risk we selected prototypical and frequent phenomena from the EASE, combining them into SQuEASE-11. To investigate this instrument for clinical relevance, basic psychometric properties, factor structure, and relationships with gold standard instruments and the full EASE, it was administered as an interview in the STEP intervention trial (Melbourne, Australia), with 328 clinical high-risk for psychosis (CHR-P) patients. STUDY RESULTS: The SQuEASE-11 had moderate internal consistency and revealed two correlated factors. Significant relationships were observed between the SQuEASE-11 and the widely used and validated instruments CAARMS, BPRS, SANS, MADRS, DACOBS, and SOFAS. The correlation with the full EASE was very strong. CONCLUSIONS: These 11 items do not necessarily relate specifically to ipseity disturbance, but the SQuEASE-11 seems to be a clinically relevant and brief supplementary first-line interview in CHR-P subjects. It may give a qualified indication of the need for a complete EASE interview, and it may also, importantly, inform treatment planning.

5.
Artículo en Inglés | MEDLINE | ID: mdl-39241799

RESUMEN

The quest for intrinsically ferromagnetic topological materials is a focal point in the study of topological phases of matter, as intrinsic ferromagnetism plays a vital role in realizing exotic properties such as the anomalous Hall effect (AHE) in quasi-two-dimensional materials, and this stands out as one of the most pressing concerns within the field. Here, we investigate a novel higher order member of the MnSb2nTe3n+1family, MnSb12Te19, for the first time combining magnetotransport and angle-resolved photoemission spectroscopy (ARPES) measurements. Our magnetic susceptibility experiments identify ferromagnetic transitions at temperature Tc= 18.7 K, consistent with our heat capacity measurements (T=18.8 K). The AHE is observed for the field along the c-axis below Tc. Our study of Shubinikov-de-Haas (SdH) oscillations provides evidence for Dirac fermions with π Berry phase. Our comprehensive investigation reveals that MnSb12Te19exhibits a FM ground state along with AHE, and hole-dominated transport properties consistent with ARPES measurements.

6.
J Formos Med Assoc ; 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39242224

RESUMEN

BACKGROUND: To evaluate the association between the pulmonary vein (PV) entry site morphology after total anomalous pulmonary vein repair (TAPVC) and postoperative pulmonary vein stenosis (PVS). METHODS: Computed tomography (CT) examination was performed to determine the PV entry site morphology. The width of the PV confluence was divided by the width of the left atrium (LA) to obtain the cPV/LA index. The cPV/LA index was compared between patients with and without postoperative PVS. RESULTS: Fifty-one patients who had undergone CT after TAPVC repair were included, with a median cPV/LA index of 0.5 (interquartile range (IQR) = 0.349-0.654). Among them, 27 patients developed postoperative PVS. The median cPV/LA index after primary TAPVC repair was significantly lower in patients with PVS compared to those without PVS (0.367, IQR = 0.308-0.433 vs. 0.657, IQR = 0.571-0.783, P < 0.0001). Additionally, the cPV/LA index after surgical re-intervention for PVS was significantly smaller in patients who developed recurrent stenosis compared to those who remained free-from re-stenosis after surgical relief (0.459, IQR = 0.349-0.556; vs. 0.706, IQR = 0.628-0.810, P = 0.0045). CONCLUSION: A small PV confluence width is associated with the development of postoperative PVS and recurrent stenosis after surgical relief of PVS. Our results suggest that adequate bilateral pulmonary vein lateralization during TAPVC surgery is crucial.

7.
Rep Prog Phys ; 87(10)2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39222655

RESUMEN

Symmetry-breaking orders can not only compete with each other, but also be intertwined, and the intertwined topological and symmetry-breaking orders make the situation more intriguing. This work examines the archetypal correlated flat band model on a checkerboard lattice at fillingν=2/3and we find that the unique interplay between smectic charge order and topological order gives rise to two novel quantum states. As the interaction strength increases, the system first transitions from a Fermi liquid (FL) into FQAH smectic (FQAHS) state, where the topological order coexists cooperatively with smectic charge order with enlarged ground-state degeneracy and interestingly, the Hall conductivity isσxy=ν=2/3, different from the band-folding or doping scenarios. Further increasing the interaction strength, the system undergoes another quantum phase transition and evolves into a polar smectic metal (PSM) state. This emergent PSM is an anisotropic non-Fermi liquid, whose interstripe tunneling is irrelevant while it is metallic inside each stripe. Different from the FQAHS and conventional smectic orders, this PSM spontaneously breaks the two-fold rotational symmetry, resulting in a nonzero electric dipole moment and ferroelectric order. In addition to the exotic ground states, large-scale numerical simulations are also used to study low-energy excitations and thermodynamic characteristics. We find that the onset temperature of the incompressible FQAHS state, which also coincides with the onset of non-polar smectic order, is dictated by the magneto-roton modes. Above this onset temperature, the PSM state exists at an intermediate-temperature regime. Although theT = 0 quantum phase transition between PSM and FQAHS is first order, the thermal FQAHS-PSM transition could be continuous. We expect the features of the exotic states and thermal phase transitions could be accessed in future experiments.

8.
Artículo en Inglés | MEDLINE | ID: mdl-39248114

RESUMEN

The patient is a 35-week-old, 2.6-kg neonate who was diagnosed prenatally with hypoplastic left heart syndrome and a supracardiac variant of total anomalous pulmonary venous connection. We present the technique of stage 1 hybrid palliation combined with repair of total anomalous pulmonary venous connection. Due to the risk of retrograde aortic arch obstruction from the ductal stents, a reverse Blalock-Taussig shunt was performed as well.


Asunto(s)
Procedimiento de Blalock-Taussing , Síndrome del Corazón Izquierdo Hipoplásico , Procedimientos de Norwood , Humanos , Procedimiento de Blalock-Taussing/métodos , Procedimientos de Norwood/métodos , Síndrome del Corazón Izquierdo Hipoplásico/cirugía , Recién Nacido , Procedimientos Quirúrgicos sin Sutura/métodos , Síndrome de Cimitarra/cirugía , Femenino , Masculino
10.
Adv Sci (Weinh) ; : e2405945, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39229956

RESUMEN

Realizing spin transport between heavy metal and two-dimensional (2D) magnetic materials at high Curie temperature (TC) is crucial to advanced spintronic information storage technology. Here, environmentally stable 2D nonlayered Fe3O4 nanosheets are successfully synthesized using a reproducible process and found that they exhibit vortex magnetic domains at room temperature. A Verwey phase transition temperature (TV) of ≈110 K is identified for ≈3 nm thick nanosheet through Raman characterization and spin Hall device measurement of the Pt/Fe3O4 bilayer. The anisotropic magnetoresistance ratio decreases near TV, while both the spin Hall magnetoresistance ratio and spin mixing conductance (Gr) increase at TV. As the temperature approaches 112 K, the anomalous Hall effect ratio tends to become zero. The maximum Gr reaches ≈5 × 1015 Ω-1m-2 due to the clean and flat interface between Pt and 2D nanosheet. The observed spin transport behavior in Pt/Fe3O4 spin Hall devices indicates that 2D Fe3O4 nanosheets possess potential for high-power micro spintronic storage devices applications.

11.
Rep Prog Phys ; 87(10)2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39151466

RESUMEN

The study of topological band insulators has revealed fascinating phases characterized by band topology indices and anomalous boundary modes protected by global symmetries. In strongly correlated systems, where the traditional notion of electronic bands becomes obsolete, it has been established that topological insulator phases persist as stable phases, separate from the trivial insulators. However, due to the inability to express the ground states of such systems as Slater determinants, the formulation of generic variational wave functions for numerical simulations is highly desirable. In this paper, we tackle this challenge for two-dimensional topological insulators by developing a comprehensive framework for fermionic tensor network states. Starting from simple assumptions, we obtain possible sets of tensor equations for any given symmetry group, capturing consistent relations governing symmetry transformation rules on tensor legs. We then examine the connection between these tensor equations andnon-chiraltopological insulators by constructing edge theories and extracting quantum anomaly data from each set of tensor equations. By exhaustively exploring all possible sets of equations, we achieve a systematic classification of non-chiral topological insulator phases. Imposing the solutions of a given set of equations onto local tensors, we obtain generic variational wavefunctions for the corresponding topological insulator phases. Our methodology provides an important step toward simulating topological insulators in strongly correlated systems. We discuss the limitations and potential generalizations of our results, paving the way for further advancements in this field.

12.
J Vet Cardiol ; 55: 19-25, 2024 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-39116587

RESUMEN

A one-year-old male intact American bulldog was presented for evaluation of previously diagnosed pulmonary stenosis. Echocardiography identified ultra-severe stenosis with an instantaneous trans-pulmonary pressure gradient of 240 mmHg. Angiography confirmed the presence of an anomalous coronary artery with a prepulmonic course of the left coronary artery arising from a single right coronary ostium consistent with a type R2A coronary anomaly. A trans-pulmonary stent was successfully placed transvenously with diameter sizing based on coronary compression testing. No coronary compression was present on postimplantation angiography. A marked reduction in the pressure gradient was obtained on postoperative echocardiography (reduction to 68 mmHg), despite selecting a stent diameter less than the pulmonary annulus diameter. This is the first report of the use of coronary compression testing in transvenous trans-pulmonic stent implantation in a dog with a type R2A coronary artery anomaly. Selection of a stent diameter less than the pulmonary annulus diameter conveyed a clinically relevant reduction in the trans-pulmonic pressure gradient while avoiding coronary compression in this case.

13.
Cureus ; 16(7): e64940, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39156246

RESUMEN

The congenital anomalous origin of the right coronary artery (AORCA) with an incongruous course is a rare malformation that can manifest as exertional chest pain, syncope, arrhythmias, heart failure, and sudden cardiac death. We present a case of a 42-year-old male with a history of hypercholesterolemia who presented with chest pain and dizziness upon exertion for two weeks. The physical examination was unremarkable, and the patient was hemodynamically stable. Initial blood tests were normal. Electrocardiogram (ECG) showed sinus bradycardia at 56 bpm without ST or T wave changes. A cardiac stress test indicated antero-apical inducible ischemia with a moderate probability of stress-induced ischemia. Computed tomography angiography (CTA) revealed an AORCA with a high interarterial course between the pulmonary artery and the aorta. Subsequent left heart catheterization confirmed the anomalous origin and revealed atherosclerotic disease. This anomaly was identified as the cause of the patient's symptoms due to the compression of the right coronary artery (RCA). The patient was treated with aspirin and statin and underwent successful internal mammary artery-RCA bypass grafting. Postoperatively, the patient's symptoms resolved, and there were no further episodes of chest pain.

14.
15.
JACC Asia ; 4(8): 594-606, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39156514

RESUMEN

Background: Pulmonary vein stenosis (PVS) continues to be a major complication after surgical repair of total anomalous pulmonary venous connection (TAPVC). Recent studies suggest that the morphology of pulmonary venous confluence and the left atrium (LA) is associated with PVS. However, there are limited data on the prognostic value of integrating quantitative confluence-atrial morphology into risk stratification. Objectives: This study sought to evaluate the prognostic impact of novel imaging metrics derived from 3-dimensional (3D) computed tomography angiography (CTA) modeling on postsurgical PVS (PPVS) in the supracardiac TAPVC (sTAPVC) setting. Methods: Patients undergoing sTAPVC repair in 2017 to 2022 from 3 centers were retrospectively reviewed. Study investigators developed 3D CTA modeled geometric features to quantify confluence-atrial morphology that were analyzed with regard to PPVS. Results: Of the 162 patients (median age 61 days; 55% having preoperative pulmonary venous obstruction [prePVO]) included, 47 (29%) with PPVS at a median of 1.5 months ([quartile 1-quartile 3: 1.5-3.0 months]). In the univariable analysis, the indexed total volume of the LA and confluence (iTVLC) and the ratio of the corresponding confluence length to the mean distance between the LA and confluence (CCL/mDBLC ratio) were significantly associated with PPVS. In a multivariable model adjusting for prePVO and age, the iTVLC and CCL/mDBLC ratio independently predicted PPVS (HR: 1.15; 95% CI: 1.06-1.25; and HR: 1.20; 95% CI: 1.08-1.35, respectively, all P < 0.01). Specifically, an iTVLC ≥20 cm3/m2 and a CCL/mDBLC ratio ≥7.7 were significantly associated with a reduced risk of PPVS. Conclusions: Quantification of 3D confluence-atrial morphology appears to offer a deeper and better metric to predict PPVS in patients with sTAPVC.

16.
JACC Case Rep ; 29(15): 102442, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39157564

RESUMEN

The following case details a 67-year-old male with a history of heart failure with reduced ejection fraction secondary to cardiac amyloidosis who underwent orthotopic heart transplantation and was later found to have an anomalous left circumflex arising from the right coronary artery in the donor heart.

17.
Artículo en Inglés | MEDLINE | ID: mdl-39159883

RESUMEN

BACKGROUND: To examine the safety and effectiveness of proactive tracheoplasty for pediatric ring-sling complexes. METHODS: We retrospectively collected the data from 304 children who were diagnosed with a ring-sling complex and underwent surgery at three cardiac centers in China between January 2010 and June 2023. Children were categorized into three surgical groups: concurrent sling and tracheal surgery (Group A, n=258), staged sling and tracheal surgery (Group B, n=25), and sling-only surgery (Group C, n=21). We compared perioperative clinical characteristics, tracheal morphology changes, and outcomes across the groups. RESULTS: The median age of the children was 1.2 (IQR: 0.7-1.9) years. The anomalous tracheobronchial arborization rates were higher in Groups A (52.5%) and B (60.0%) than in Group C (15.0%). The preoperative narrow-wide ratio (NWR) was lower in Groups A and B than in Group C, with values of 0.44 (IQR: 0.35-0.52), 0.44 (0.33-0.59), and 0.68 (0.54-0.72), respectively (P<0.001). Preoperative subcarina angles were similar among the groups (P=0.54). After specific surgeries, the NWR and subcarina angle significantly improved in Groups A and B but not in Group C. There were seven in-hospital deaths and two post-discharge deaths. Respiratory symptoms improved in Groups A and B but seven children in Group C remained respiratory dysfunction. Six children presented with residual stenosis of the left pulmonary artery. CONCLUSION: Concurrent sling and tracheal surgeries for children with the ring-sling complex are safe and effective and are especially preferable for those with NWR ≤0.6, long-segment or diffuse tracheal stenosis, anomalous tracheobronchial arborization, and pronounced respiratory symptoms.

18.
Eur J Pediatr ; 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39155320

RESUMEN

Anomalous aortic origin of a coronary artery (AAOCA) is associated with sudden death in the young. Risk stratification and management decision-making remain challenging. Data addressing post-diagnosis perceptions of exercise behavior and safety are lacking. We aimed to determine how AAOCA affects exercise behaviors, safety perceptions, and emotional well-being of patients/parents. Qualitative and quantitative analysis of AAOCA patient-/parent-specific survey was conducted to examine exercise frequency/restrictions, perceived safety of competitive/recreational exercise, and psychosocial well-being. Subgroups stratified by AAOCA subtype, surgical intervention, and physician-driven restrictions were compared using chi-squared and Fisher's exact tests. Cohen's kappa determined agreement in parent/child responses. AAOCA subtypes included 13 (24%) left AAOCA, 36 (67%) right AAOCA, and 5 (9%) other/unknown. Of 54 parents and 41 paired child responses, 22% of patients were physician-restricted from exercise. Parents imposed restrictions on competitive/recreational exercise 34%/26% of the time, respectively. Children without physician restrictions still self-restricted exercise 35% of the time. Parents reported feeling their child was unsafe exercising 61% competitively and 33% recreationally. Twenty-two percent of children reported feeling unsafe exercising, with good agreement to parental perceptions of competitive exercise safety (kappa = 0.779, p < 0.001). One-third of parents and children reported feeling sad, angry, or lonely, and about half reported feeling different. Importantly, 47% of children desired to exercise more. No difference was seen across restriction status, AAOCA subtype, or surgical management strategy. CONCLUSION: There are different perceptions of exercise behavior and safety following AAOCA evaluation, regardless of risk category or management strategy, impacting their well-being. These unmet needs should be at the forefront of care. WHAT IS KNOWN: • AAOCA is one of the leading causes of sudden cardiac death in the young. • Exercise restriction varies according to AAOCA subtype and its perceived risk of inducing myocardial ischemia. WHAT IS NEW: • There are different perceptions of exercise behavior and safety in patients and parents following a diagnosis of AAOCA, impacting their well-being. • Risk category or management strategy has no effect in patients' and parents' perception of exercise safety. • These unmet needs in this population should be at the forefront of care.

19.
Structure ; 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39151418

RESUMEN

Aging workers of the termite Neocapritermes taracua can defend their colony by sacrificing themselves by body rupture, mixing the externally stored blue laccase BP76 with hydroquinones to produce a sticky liquid rich in toxic benzoquinones. Here, we describe the crystal structure of BP76 isolated from N. taracua in its native form. The structure reveals several stabilization strategies, including compact folding, glycosylation, and flexible loops with disulfide bridges and tight dimer interface. The remarkable stability of BP76 maintains its catalytic activity in solid state during the lifespan of N. taracua workers, providing old workers with an efficient defensive weapon to protect their colony.

20.
AME Case Rep ; 8: 75, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39091560

RESUMEN

Background: Anomalous right coronary artery from pulmonary artery (ARCAPA) is one of four known anomalies of the coronary arteries originating from the pulmonary artery. ARCAPA is a rare congenital anomaly that is associated with possible long-term complications including myocardial ischemia and left ventricular dysfunction. Clinical presentation can vary from asymptomatic murmur to angina, dyspnea, fatigue, congestive heart failure, myocardial infarction and even cardiac arrest. Case Description: We present a case of a 52-year-old male who presented to the hospital for intermittent chest pain. The patient was vitally stable and examination was unremarkable. Upon workup, electrocardiogram (EKG) on admission showed no acute ischemic changes and troponin were <0.03 ng/mL. The patient was evaluated by cardiology and had a dobutamine stress echocardiogram (ECHO) for ischemic evaluation. During the recovery phase of dobutamine stress ECHO, the patient reported having 10/10 chest pain with a drop in blood pressure to 90 mmHg systolic. He was subsequently given sublingual nitroglycerin and fluids. Pain did resolve and blood pressure improved after treatment. No wall motion abnormalities were noted on ECHO, but there were inferior ST depressions on EKG during the stress portion of the test. The patient had repeated blood work after the stress test which showed an elevated troponin level of 0.08 ng/mL. The patient was taken to the catheterization lab for diagnostic coronary angiogram. Cardiac catheterization showed a right coronary artery (RCA) arising from the pulmonary artery and diagnosis of isolated ARCAPA was made because of his intermittent chest pain. No intervention was performed as no significant lesions were found. The patient was started on medical therapy including aspirin, beta blocker and statin. The patient did not want to pursue surgery at that point and he did not want any further intervention. He was discharged home with instructions to follow up with cardiology in an outpatient setting to be referred for surgical repair. Conclusions: The purpose of writing this case is to increase awareness among physicians to be able to recognize possible anomalous coronary artery origins during cardiac catheterization and to understand the risk of long-term complications of ARCAPA and need for surgical repair.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA