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1.
Phys Rev Lett ; 132(16): 160401, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38701449

RESUMEN

Finding a local Hamiltonian H[over ^] that has a given many-body wave function |ψ⟩ as its ground state, i.e., a parent Hamiltonian, is a challenge of fundamental importance in quantum technologies. Here we introduce a numerical method, inspired by quantum annealing, that efficiently performs this task through an artificial inverse dynamics: a slow deformation of the states |ψ(λ(t))⟩, starting from a simple state |ψ_{0}⟩ with a known H[over ^]_{0}, generates an adiabatic evolution of the corresponding Hamiltonian. We name this approach inverse quantum annealing. The method, implemented through a projection onto a set of local operators, only requires the knowledge of local expectation values, and, for long annealing times, leads to an approximate parent Hamiltonian whose degree of locality depends on the correlations built up by the states |ψ(λ)⟩. We illustrate the method on two paradigmatic models: the Kitaev fermionic chain and a quantum Ising chain in longitudinal and transverse fields.

2.
Catheter Cardiovasc Interv ; 99(1): 140-144, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34463417

RESUMEN

Ascending aorta pseudoaneurysm (AAP) is a rare but life-threatening complication of atherosclerosis, endocarditis, chest trauma, transcatheter or cardio-thoracic procedures. Since surgical repair is burdened by high morbidity and mortality, percutaneous closure is nowadays considered a valuable cost-effective therapeutic alternative. Due to unpredictability and complexity of local anatomy, no standardized technique and device are advised. In this setting, 3D printing technology could significantly help in planning trans-catheter approach. This article reports on a 3D printed model-guided percutaneous closure of a huge AAP using an Amplatzer Septal Occluder (Abbott, Plymouth MN) implanted by the recently commercialized Amplatzer Trevisio Intravascular Delivery System.


Asunto(s)
Aneurisma Falso , Dispositivo Oclusor Septal , Aneurisma Falso/diagnóstico por imagen , Aneurisma Falso/etiología , Aneurisma Falso/cirugía , Aorta/diagnóstico por imagen , Aorta/cirugía , Cateterismo Cardíaco , Humanos , Impresión Tridimensional , Resultado del Tratamiento
3.
Catheter Cardiovasc Interv ; 99(1): E22-E30, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34652048

RESUMEN

OBJECTIVE: To evaluate the GORE® Cardioform ASD Occluder (GCO) (WL Gore & Associates, Flagstaff, AZ) device for "complex" atrial septal defects (ASD) closure. BACKGROUND: Transcatheter ASD closure is still challenging in "complex" clinical/anatomic settings. This study evaluated the results of GCO in closure of "complex" ASD in a tertiary referral center. METHODS: Between January 2020 and March 2021, 72 patients with significant ASD were submitted to transcatheter closure with GCO at our Institution. Based on clinical/anatomic characteristics, they were classified as "complex" (n = 36, Group I) or "simple" (n = 36, Group II). We considered as "complex", defects with rim deficiency (< 5 mm) other than antero-superior, relatively large (diameter/patient weight > 1.2 or diameter/patient BSA > 20 mm/m2 ) or within a multifenestrated septum. Procedure results and early outcome were compared between the groups. RESULTS: Absolute and relative ASD size (20 ± 4 vs. 15 ± 3 mm, p < 0.0001; 0.9 ± 0.3 vs. 0.4 ± 0.2 mm/kg, p < 0.0001; 23 ± 7 vs. 12 ± 5 mm/m2 , p < 0.0001), QP/QS (2.0 ± 0.8 vs. 1.4 ± 0.3, p < 0.001), procedure and fluoroscopy times (73 ± 36 vs. 43 ± 21 min, p < 0.0001; 16 ± 9 vs. 9 ± 4 min, p < 0.0001, procedure feasibility (94.4 vs. 100%, p < 0.0001) and overall complication rate (13.9 vs. 0%, p < 0.0001) were significantly different between the groups. Successful closure of "surgical" ASDs was achieved in 92% of cases. Complete closure at last follow-up evaluation did not significantly differ between the groups (97.1 vs. 100%, p = NS), as was wireframe fractures rate (49.1% in the overall population), without clinical, EKG and echocardiographic consequences. CONCLUSIONS: Percutaneous treatment with GCO device is effective and safe in high percentage of "complex" ASDs.


Asunto(s)
Defectos del Tabique Interatrial , Dispositivo Oclusor Septal , Cateterismo Cardíaco/efectos adversos , Ecocardiografía Transesofágica , Defectos del Tabique Interatrial/diagnóstico por imagen , Defectos del Tabique Interatrial/terapia , Humanos , Diseño de Prótesis , Factores de Tiempo , Resultado del Tratamiento
4.
Catheter Cardiovasc Interv ; 99(7): 2043-2053, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35420259

RESUMEN

BACKGROUND: To date, extensive experience in transcatheter closure of fenestrated atrial septal aneurysm (ASA) in the pediatric population is limited. METHODS: To report on procedural feasibility, efficacy, and long-term outcome, we enrolled all children submitted to an attempt of transcatheter closure of fenestrated ASA at two, large volume, pediatric cardiology units (Naples and Massa, Italy) between April 2000 to May 2020. RESULTS: This retrospective study included 139 patients (median age 9 years [range 2-18] and weight 36 kg [range 10-102]); 19 (13.7%) children were ≤20 kg (range 10-20) and 14 (10.1%) were ≤5 years old. Single perforation was observed in 28 patients (20.1%), while 111 patients (79.9%) had multifenestrated ASA. The median size of the main defect was 15 mm (range 6-34) and 25 patients (18%) had a defect ≥20 mm. The procedural success rate was 99% (95% confidence interval [CI]: 94.9-99.8) using a single device in 75 (69%), two devices in 31 (28%), and three devices in 3 (3%) cases. Early minor adverse events (AEs) occurred in four patients (2.8%). Late minor AEs were recorded in one patient (0.7%) over a median follow-up of 5 years ([range 0-18 years; total 890.2 person-years, and with 30 patients (22%) followed ≥10 years). Neither mortality nor major AEs were recorded. Freedom from AEs was 99.1% at 10-15 years (95% CI: 93.5-99.8%), without any difference according to atrial septum anatomy or patient age and weight. CONCLUSION: Transcatheter closure of fenestrated ASA is technically feasible and effective in children with excellent long-term outcomes.


Asunto(s)
Aneurisma Cardíaco , Defectos del Tabique Interatrial , Dispositivo Oclusor Septal , Adolescente , Cateterismo Cardíaco , Niño , Preescolar , Estudios de Factibilidad , Aneurisma Cardíaco/etiología , Humanos , Estudios Retrospectivos , Resultado del Tratamiento
5.
Echocardiography ; 39(5): 724-731, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35466466

RESUMEN

OBJECTIVES: This study aimed to identify clinical, hemodynamic, or echocardiographic predictive features of persistent duct-dependency of pulmonary circulation (PDDPC) after effective percutaneous relief of pulmonary atresia with the intact ventricular septum (PA-IVS) or critical pulmonary stenosis (CPS). METHODS: From 2010 to 2021, 55 neonates with PA-IVS or CPS underwent percutaneous right ventricle (RV) decompression at our Institution. After successfully relief of critical obstruction, 27 patients (group I) showed PDDPC, whereas RV was able to support the pulmonary circulation in the remaining 28 patients (group II). Clinical, hemodynamic, and echocardiographic features of these two groups were compared. RESULTS: No significant difference in clinical and hemodynamic data was found between the groups, although the group I had a lower oxygen saturation at hospital admission. However, tricuspid valve (TV) diameter <8.8 mm, TV z-score ←2.12, tricuspid/mitral valve annular ratio <.78, pulmonary valve diameter <6.7 mm, pulmonary valve z-score ←1.17, end-diastolic RV area <1.35 cm2 , end-systolic right atrium area >2.45 cm2 , percentage amount of interatrial right-to-left shunt >69.5%, moderate/severe tricuspid regurgitation, RV systolic pressure >42.5 mmHg, tricuspid E/E' ratio >6.6 showed each significant predictive value of PDDPC. These parameters were used to build a composite echocardiographic score (PDDPC-score), assigning one point each above the respective cut-off value. A score ≥4.00 showed high sensitivity (100%) and specificity (86%) in predicting PDDPC. CONCLUSION: Clinical and hemodynamic features fail to predict the short-term fate of the pulmonary circulation after successful treatment of PA-IVS/CPS. However, a simple, composite echocardiographic score is useful to predict PDDPC and could be crucial in the management of this frail subset of patients.


Asunto(s)
Cardiopatías Congénitas , Atresia Pulmonar , Estenosis de la Válvula Pulmonar , Válvula Pulmonar , Constricción Patológica , Ecocardiografía , Cardiopatías Congénitas/cirugía , Humanos , Recién Nacido , Atresia Pulmonar/diagnóstico por imagen , Atresia Pulmonar/cirugía , Estenosis de la Válvula Pulmonar/diagnóstico por imagen , Estenosis de la Válvula Pulmonar/cirugía , Resultado del Tratamiento
6.
J Card Surg ; 37(10): 3200-3206, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35900295

RESUMEN

OBJECTIVE: To evaluate the GORE® Cardioform ASD Occluder (GCA)(WL Gore & Associates) device for closure of ostium secundum atrial septal defects (ASDs) with predicted indication for surgical correction. BACKGROUND: Closure of large ASD in small children by transcatheter approach is still challenging. This study evaluated the results of GCA in this subset of patients in a tertiary referral center. METHODS: Between January 2020 and March 2022, 97 children underwent transcatheter ASD closure at our Institution. Of them, 38 had a large defect (diameter/weight > 1.2 or diameter/body surface area > 20 mm/m2 ), predicted suitable for surgery and underwent closure with GCA. Procedure results and midterm outcome are reported. RESULTS: Patients' age and weight were 5.5 ± 1.5 years and 19.7 ± 4.7 kg, respectively. Absolute and relative ASD size was 21.5 ± 3.6 mm, 1.1 ± 0.2 mm/kg, and 27.7 ± 4.6 mm/m2 , respectively, resulting in QP/QS of 2.0 ± 0.8. Three patients were sent to surgery after balloon sizing. Four of the remaining 35 patients who underwent device deployment, needed rescue or elective surgery due to device embolization (n = 1), device instability (n = 2) or new-onset tricuspid valve regurgitation (n = 1). Procedure feasibility was 88.6%. Major complications were recorded in two patients (5.7%). Minor complications were recorded in five patients (14.3%). Complete closure at discharge was 90.3% (28/31 pts) rising to 100% at the last follow-up evaluation. Wireframe fracture rate at the 6 months examination was 52%, without clinical and instrumental consequences. CONCLUSIONS: Percutaneous treatment with GCA device is effective and safe in a high percentage of ASD children with predicted indications for surgical correction.


Asunto(s)
Defectos del Tabique Interatrial , Dispositivo Oclusor Septal , Cateterismo Cardíaco/métodos , Niño , Defectos del Tabique Interatrial/cirugía , Humanos , Diseño de Prótesis , Resultado del Tratamiento
7.
Cardiol Young ; 32(12): 1930-1937, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34961571

RESUMEN

BACKGROUND: Growing evidence has emphasised the importance of ventricular performance in functionally single-ventricle patients, particularly concerning diastolic function. Cardiac MRI has been proposed as non-invasive alternative to pre-Fontan cardiac catheterisation in selected patients. AIM OF THE STUDY: To identify clinical and cardiac magnetic resonance predictors of high pre-Fontan end-diastolic ventricular pressure. METHOD: In a retrospective single-centre study, 38 patients with functionally univentricular heart candidate for Fontan intervention, who underwent pre-Fontan cardiac catheterisation, beside a comprehensive cardiac MRI, echocardiographic, and clinical assessment were included. Medical and surgical history, cardiac magnetic resonance, cardiac catheterisation, echocardiographic, and clinical data were recorded. We investigated the association between non-invasive parameters and cardiac catheterisation pre-Fontan risk factors, in particular with end-diastolic ventricular pressure. Moreover, the impact of conventional invasive pre-Fontan risk factor on post-operative outcome as also assessed. RESULTS: Post-operative complications were associated with higher end-diastolic ventricular pressure and Mayo Clinic indexes (p < 0.01 and p = 0.05, respectively). At receiver operating characteristic curve analysis end-diastolic ventricular pressure ≥ 10.5 mmHg predicted post-operative complications with a sensitivity of 75% and specificity of 88% (AUC: 0.795, 95% CI 0.576;1.000, p < 0.05). At multivariate analysis, both systemic right ventricle (OR: 23.312, 95% CI: 2.704-200.979, p < 0.01) and superior caval vein indexed flow (OR: 0.996, 95% CI: 0.993-0.999, p < 0.05) influenced end-diastolic ventricular pressure ≥ 10.5 mmHg. CONCLUSIONS: A reduced superior caval vein flow, evaluated at cardiac magnetic resonance, is associated with higher end-diastolic ventricular pressure a predictor of early adverse outcome in post-Fontan patients.


Asunto(s)
Procedimiento de Fontan , Cardiopatías Congénitas , Humanos , Presión Ventricular , Estudios Retrospectivos , Vena Cava Superior/cirugía , Diástole , Procedimiento de Fontan/efectos adversos , Ventrículos Cardíacos , Cardiopatías Congénitas/diagnóstico por imagen , Cardiopatías Congénitas/cirugía , Imagen por Resonancia Magnética
8.
BMC Med Educ ; 22(1): 642, 2022 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-35999626

RESUMEN

BACKGROUND: Through the provision of advice and counselling, general practitioners (GPs) play an important part in promoting physical activity (PA). Lack of knowledge is a key barrier to engaging in such practice. Little is known about the knowledge and attitudes of current medical students and their preparedness to engage in PA promoting practice in the future. This study aimed to investigate the PA knowledge, attitudes and behaviours of medical students attending an Australian university. METHODS: A sample of 107 pre-clinical medical students from an Australian university completed an online survey. Questions asked about age, sex and past-week PA behaviour (using the International Physical Activity Questionnaire-Short form) as well as understanding of key PA messages and perceptions of the role of a GP, confidence to engage in PA promoting practices and satisfaction with current medical school training (responses were on 5-point Likert scale). Descriptive statistics (proportions, means) were used to summarise demographic and attitudinal measures. RESULTS: Almost all students (92%) were categorised as being moderately or highly active in the past-week. Knowledge of key PA messages was moderate (3.6 ± 0.9), however understanding of key messages about the dose of PA varied (ranging from 0% to 80.4% agreement). GPs were regarded as having a role to play in promoting PA; with high agreement that discussing the benefits of PA is a part of the role of a GP (4.7 ± 0.5). There was only moderate agreement that participants had received training in the health benefits of PA (3.1 ± 1.0) and in PA counselling (3.2 ± 1.0). Students indicated lower levels of satisfaction with this training (2.5 ± 0.9). CONCLUSIONS: Students in this study were typically physically active, had positive attitudes toward PA and felt that it was the role of the GP to engage in PA promoting practices. Students understood key PA messages, and while they reportedly received some training in providing PA counselling, they were somewhat dissatisfied with this training.


Asunto(s)
Estudiantes de Medicina , Australia , Ejercicio Físico , Conocimientos, Actitudes y Práctica en Salud , Humanos , Encuestas y Cuestionarios , Universidades
9.
Int J Mol Sci ; 23(21)2022 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-36361932

RESUMEN

Polydeoxyribonucleotide (PDRN) is an agonist of the A2A adenosine receptor derived from salmon trout sperm. Selenium (Se) is a trace element normally present in the diet. We aimed to investigate the long-term role of PDRN and Se, alone or in association, after ischemia-reperfusion (I/R) in rats. The animals underwent 1 h testicular ischemia followed by 30 days of reperfusion or a sham I/R and were treated with PDRN or Se alone or in association for 30 days. I/R significantly increased hypoxia-inducible factor 1-α (HIF-1α) in Leydig cells, malondialdehyde (MDA), phosphorylated extracellular signal-regulated kinases 1/2 (pErk 1/2), and apoptosis decreased testis weight, glutathione (GSH), testosterone, nuclear factor erythroid 2-related factor 2 (Nrf2), induced testicular structural changes, and eliminated HIF-1α spermatozoa positivity. The treatment with either PDRN or Se significantly decreased MDA, apoptosis, and HIF-1α positivity of Leydig cells, increased testis weight, GSH, testosterone, and Nrf2, and improved the structural organization of the testes. PDRN and Se association showed a higher protective effect on all biochemical, structural, and immunohistochemical parameters. Our data suggest that HIF-1α could play important roles in late testis I/R and that this transcriptional factor could be modulated by PDRN and Se association, which, together with surgery, could be considered a tool to improve varicocele-induced damages.


Asunto(s)
Daño por Reperfusión , Selenio , Ratas , Masculino , Animales , Polidesoxirribonucleótidos/farmacología , Factor 2 Relacionado con NF-E2/análisis , Selenio/farmacología , Selenio/análisis , Ratas Sprague-Dawley , Semen , Testículo , Isquemia , Daño por Reperfusión/tratamiento farmacológico , Subunidad alfa del Factor 1 Inducible por Hipoxia/análisis , Reperfusión , Testosterona/análisis
10.
Echocardiography ; 38(4): 707-715, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33729605

RESUMEN

We report applications of novel high-frame rate blood speckle tracking (BST) echocardiography in a series of infants with congenital heart disease (CHD). BST echocardiography was highly feasible, reproducible, and fast. High-frame rate BST provided complimentary information to conventional color-Doppler data enhancing the visualization and understanding of anomalous blood trajectories (eg, shunt direction, regurgitant volumes, and stenotic jets) and vortex formation. High-frame rate BST echocardiography is a new, promising imaging tool that may be helpful for deeper understanding of complex CHD physiology.


Asunto(s)
Ecocardiografía , Cardiopatías Congénitas , Velocidad del Flujo Sanguíneo , Corazón , Cardiopatías Congénitas/diagnóstico por imagen , Humanos , Lactante
11.
Acta Paediatr ; 110(8): 2336-2343, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33948967

RESUMEN

Congenital heart disease (CHD) and cardiomyopathies represent the two most important causes of paediatric heart failure (HF) in developed countries. We made a review of the literature on pathophysiology and clinical presentation of paediatric HF in children with CHD. Two main pathophysiologic models can be identified: the 'over-circulation failure', characterised by signs and symptoms of congestion or hypoperfusion, due respectively to volume or pressure overload, and the 'pump failure'. CONCLUSIONS: The comprehension of the HF pathophysiology in paediatric patients with CHD is of paramount importance for the optimal management and for addressing the best therapeutic choices.


Asunto(s)
Cardiomiopatías , Cardiopatías Congénitas , Insuficiencia Cardíaca , Niño , Cardiopatías Congénitas/complicaciones , Insuficiencia Cardíaca/etiología , Humanos
12.
Proc Natl Acad Sci U S A ; 115(14): 3547-3550, 2018 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-29555763

RESUMEN

The quantum motion of nuclei, generally ignored in the physics of sliding friction, can affect in an important manner the frictional dissipation of a light particle forced to slide in an optical lattice. The density matrix-calculated evolution of the quantum version of the basic Prandtl-Tomlinson model, describing the dragging by an external force of a point particle in a periodic potential, shows that purely classical friction predictions can be very wrong. The strongest quantum effect occurs not for weak but for strong periodic potentials, where barriers are high but energy levels in each well are discrete, and resonant Rabi or Landau-Zener tunneling to states in the nearest well can preempt classical stick-slip with nonnegligible efficiency, depending on the forcing speed. The resulting permeation of otherwise unsurmountable barriers is predicted to cause quantum lubricity, a phenomenon which we expect should be observable in the recently implemented sliding cold ion experiments.

13.
J Clin Monit Comput ; 35(5): 1149-1157, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-32816177

RESUMEN

During one-lung ventilation (OLV), titrating the positive end-expiratory pressure (PEEP) to target a low driving pressure (∆P) could reduce postoperative pulmonary complications. However, it is unclear how to conduct PEEP titration: by stepwise increase starting from zero PEEP (PEEPINCREMENTAL) or by stepwise decrease after a lung recruiting manoeuvre (PEEPDECREMENTAL). In this randomized trial, we compared the physiological effects of these two PEEP titration strategies on respiratory mechanics, ventilation/perfusion mismatch and gas exchange. Patients undergoing video-assisted thoracoscopic surgery in OLV were randomly assigned to a PEEPINCREMENTAL or PEEPDECREMENTAL strategy to match the lowest ∆P. In the PEEPINCREMENTAL group, PEEP was stepwise titrated from ZEEP up to 16 cm H2O, whereas in the PEEPDECREMENTAL group PEEP was decrementally titrated, starting from 16 cm H2O, immediately after a lung recruiting manoeuvre. Respiratory mechanics, ventilation/perfusion mismatch and blood gas analyses were recorded at baseline, after PEEP titration and at the end of surgery. Sixty patients were included in the study. After PEEP titration, shunt decreased similarly in both groups, from 50 [39-55]% to 35 [28-42]% in the PEEPINCREMENTAL and from 45 [37-58]% to 33 [25-45]% in the PEEPDECREMENTAL group (both p < 0.001 vs baseline). The resulting ∆P, however, was lower in the PEEPDECREMENTAL than in the PEEPINCREMENTAL group (8 [7-11] vs 10 [9-11] cm H2O; p = 0.03). In the PEEPDECREMENTAL group the PaO2/ FIO2 ratio increased significantly after intervention (from 140 [99-176] to 186 [152-243], p < 0.001). Both the PEEPINCREMENTAL and the PEEPDECREMENTAL strategies were able to decrease intraoperative shunt, but only PEEPDECREMENTAL improved oxygenation and lowered intraoperative ΔP.Clinical trial number NCT03635281; August 2018; "retrospectively registered".


Asunto(s)
Ventilación Unipulmonar , Humanos , Pulmón , Rendimiento Pulmonar , Respiración con Presión Positiva , Mecánica Respiratoria
14.
Cardiol Young ; 30(1): 1-11, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31910934

RESUMEN

We reviewed the recent literature for echocardiographic assessment of mitral valve abnormalities in children. A literature search was performed within the National Library of Medicine using the keywords "mitral regurgitation and/or stenosis, children." The search was refined by adding the keywords "echocardiographic definition, classification, and evaluation." Thirty-one studies were finally included. Significant advances in echocardiographic imaging of mitral valve defects, mainly due to the implementation of three-dimensional technology, contribute to a better understanding of the underlying anatomy. However, heterogeneity between classification systems of mitral valve disease severity is a serious problem. For regurgitant lesions, there is only very limited evidence from small studies that support the adoption of quantitative/semi-quantitative indexes commonly employed in adults. Despite the lack of evidence base, qualitative evaluation of regurgitation severity is often employed. For stenotic lesions, no clear categorisation based on trans-valvular echocardiography-derived "gradients" has been consistently applied to define mild, moderate, or severe obstruction across different paediatric age ranges. Quantitative parameters such as valve area have also been poorly validated in children. Adult recommendations are frequently applied without validation for the paediatric age. In conclusion, significant advances in the anatomical evaluation of mitral valve diseases have been made, thanks to three-dimensional echocardiography; however, limitations remain in the quantitative/semi-quantitative estimation of disease severity, both with respect to valvular regurgitation and stenosis. Because adult echocardiographic recommendations should not be simply translated to the paediatric age, more specific paediatric guidelines and standards for the assessment of mitral valve diseases are needed.


Asunto(s)
Ecocardiografía Doppler/métodos , Insuficiencia de la Válvula Mitral/diagnóstico , Estenosis de la Válvula Mitral/diagnóstico , Válvula Mitral/diagnóstico por imagen , Niño , Humanos , Válvula Mitral/anomalías , Insuficiencia de la Válvula Mitral/congénito , Estenosis de la Válvula Mitral/congénito
15.
Phys Rev Lett ; 123(26): 266601, 2019 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-31951426

RESUMEN

We investigate the effects of disorder on a periodically driven one-dimensional model displaying quantized topological transport. We show that, while instantaneous eigenstates are necessarily Anderson localized, the periodic driving plays a fundamental role in delocalizing Floquet states over the whole system, henceforth allowing for a steady-state nearly quantized current. Remarkably, this is linked to a localization-delocalization transition in the Floquet states at strong disorder, which occurs for periodic driving corresponding to a nontrivial loop in the parameter space. As a consequence, the Floquet spectrum becomes continuous in the delocalized phase, in contrast with a pure-point instantaneous spectrum.

16.
J Magn Reson Imaging ; 49(5): 1222-1235, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30614102

RESUMEN

Our purpose is to provide an overview and to systematically review the strengths and limitations of studies on pediatric and adolescent normal values for cardiovascular MRI parameters. A literature search was performed within the National Library of Medicine using the following keywords: normal, reference values, cardiovascular magnetic resonance imaging, and children/pediatric. Eleven published studies evaluating cardiovascular MRI measurements in normal children were included in the present analysis. Our results revealed reasonable consistencies in the protocols employed for cardiovascular MRI. Inter- and intraobserver variability analyses were performed in most studies and generally showed acceptable reproducibility. However, several numerical and methodological limitations emerged. Besides small sample sizes (the largest study enrolled 114 subjects), data for some structures (pulmonary arteries, aortic arch) were limited, and neonates/infants were poorly represented (eg, only two studies). There was heterogeneity regarding measurement normalization (eg, for gender, age, or both), and data were mostly expressed as mean values, while z-scores (commonly used in pediatric echocardiography) were rarely employed. Theoretically, a z-score or a standard deviation of ±2 is considered pathological. Furthermore, differences among races and ethnic groups were not evaluated. In conclusion, our analyses revealed an important need for generation of pediatric and adolescent cardiovascular MRI nomograms built over a wide population of healthy children, using consistent methodologies and with consideration of potentially relevant confounders. More data on expected abnormal values in specific CHD populations (eg, univentricular hearts) also need to be defined. Level of Evidence: 2 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2019;49:1222-1235.


Asunto(s)
Cardiopatías Congénitas/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Nomogramas , Adolescente , Niño , Femenino , Corazón/diagnóstico por imagen , Cardiopatías Congénitas/terapia , Humanos , Lactante , Recién Nacido , Masculino , Reproducibilidad de los Resultados
17.
Int Orthop ; 43(1): 77-83, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30187098

RESUMEN

PURPOSE: This series assessed the clinical and radiographic outcomes of total hip arthroplasty (THA) with femoral shortening osteotomy for the management of patients with Crowe type IV hip dysplasia. METHODS: Only patients with Crowe type IV hip dysplasia who underwent primary THA combined with a subtrochanteric transverse osteotomy with an uncemented monoblock conical stem were included. The clinical and radiographic evaluations were performed before and immediately after surgery, and at last follow-up. The hip function was assessed with the Harris Hip Score (HHS). RESULTS: Seventy-four patients (102 hips) with a mean age of 53.9 (range, 20-83) were evaluated at an average follow-up of 11.3 years (range, 5-25). Stem revision occurred in two (1.9%) cases, with a survivorship of 95.9% (95%IC, 91.9-99.9%) at ten years. The average HHS increased from 44 (range, 15-78) pre-operatively to 90.3 (range, 62-100) at last follow-up (p < 0.001). Osteotomy site non-union and early dislocation were observed in 3.9 and 3.8%, respectively. No cases of nerve palsy were reported. CONCLUSIONS: THA with a monoblock conical stem associated with subtrochanteric transverse osteotomy provides good long-term survival, clinical and radiographic results. It may be considered an effective management of patients with Crowe IV hip dysplasia.


Asunto(s)
Artroplastia de Reemplazo de Cadera/instrumentación , Artroplastia de Reemplazo de Cadera/métodos , Fémur/cirugía , Luxación Congénita de la Cadera/cirugía , Osteotomía/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Fémur/diagnóstico por imagen , Estudios de Seguimiento , Luxación Congénita de la Cadera/clasificación , Luxación Congénita de la Cadera/diagnóstico por imagen , Prótesis de Cadera , Humanos , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Estudios Retrospectivos , Adulto Joven
18.
Phys Rev Lett ; 120(10): 106601, 2018 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-29570317

RESUMEN

We study Thouless pumping out of the adiabatic limit. Our findings show that despite its topological nature, this phenomenon is not generically robust to nonadiabatic effects. Indeed, we find that the Floquet diagonal ensemble value of the pumped charge shows a deviation from the topologically quantized limit which is quadratic in the driving frequency for a sudden switch on of the driving. This is reflected also in the charge pumped in a single period, which shows a nonanalytic behavior on top of an overall quadratic decrease. Exponentially small corrections are recovered only with a careful tailoring of the driving protocol. We also discuss thermal effects and the experimental feasibility of observing such a deviation.

19.
Pediatr Cardiol ; 39(3): 627-632, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29453685

RESUMEN

Transcatheter closure of arterial duct (AD) remains challenging in low-weight patients and using Amplatzer Duct Occluder devices is still considered off-label in infants < 6 kg. This study aimed to report a large, single-center experience of percutaneous AD closure in infants < 6 kg as well as to compare the most frequently used devices, Amplatzer Duct Occluder type I (ADO I) and Amplatzer Duct Occluder type II Additional Sizes devices (ADO II-AS) (St. Jude Medical Corp, St. Paul, MN, USA). From March 2000 to March 2017, among the 762 patients submitted to percutaneous closure of AD at our Institution, 33 were infants < 6 kg (age 4.8 ± 2.1 months; weight 5.0 ± 0.9 kg). Fourteen patients (45%) underwent ADO I (Group I) and 19 patients ADO II-AS (Group II) device implantation. AD diameter was 2.6 ± 0.8 (range 1.5-4.0) mm resulting in QP/QS of 2.6 ± 0.0.9 (range 1.1-4.5). Successful device deployment was achieved in all patients without procedural morbidity or mortality. Procedural and fluoroscopy times were not significantly different between the groups. However, total X-ray absorbed dose was significantly higher in Group I (121 ± 69 vs 29 ± 16 mGy/cm2, p < 0.01). Immediate, 24 h, and mid-term (46 ± 37 months, median 39) complete occlusion were recorded in 72.7, 90.9, and 97% of patients, respectively without significant difference between the groups. In conclusion, transcatheter closure of AD with Amplatzer Duct Occluder devices is feasible, safe, and effective also in infants less than 6 kg, without significant difference between the most commonly used devices, namely, ADO I and ADO II-AS.


Asunto(s)
Cateterismo Cardíaco/instrumentación , Conducto Arterioso Permeable/cirugía , Dispositivo Oclusor Septal , Conducto Arterioso Permeable/clasificación , Conducto Arterioso Permeable/diagnóstico por imagen , Femenino , Fluoroscopía , Humanos , Lactante , Recién Nacido de Bajo Peso , Masculino , Diseño de Prótesis , Radiografía , Resultado del Tratamiento
20.
Monaldi Arch Chest Dis ; 88(1): 895, 2018 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-29557576

RESUMEN

One of the major complications of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) is pulmonary vein stenosis (PVS). The natural history of PVS, especially when it involves more than one vein, leads to severe and irreversible pulmonary hypertension with end-stage right heart failure that can require, in extreme cases, even heart-lung transplantation. We report the case of a young patient who underwent RFCA for a single lasting episode of AF and developed PVS years later. He was treated with ballon venoplasty followed by stent implantation in left pulmonary vein because of PVS relief. This reported case emphasizes the need of an adequate indication for RFCA for AF, considering the benefit-risk ratio especially in young patients with normal cardiac function.


Asunto(s)
Fibrilación Atrial/terapia , Ablación por Catéter/efectos adversos , Venas Pulmonares/diagnóstico por imagen , Venas Pulmonares/efectos de la radiación , Angiografía , Atletas , Fibrilación Atrial/complicaciones , Fibrilación Atrial/fisiopatología , Cateterismo Cardíaco/instrumentación , Ablación por Catéter/métodos , Constricción Patológica , Humanos , Enfermedad Iatrogénica , Masculino , Tomografía Computarizada Multidetector/métodos , Venas Pulmonares/patología , Estenosis de Vena Pulmonar/diagnóstico por imagen , Estenosis de Vena Pulmonar/patología , Estenosis de Vena Pulmonar/terapia , Stents , Resultado del Tratamiento , Adulto Joven
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