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1.
World J Pediatr Congenit Heart Surg ; 13(4): 458-465, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35757951

RESUMEN

BACKGROUND: The management of total anomalous pulmonary venous connection (TAPVC) in neonates and infants is resource-intensive. We describe early and follow-up outcomes after surgical repair of isolated TAPVC at a single institution in a resource-limited setting. METHODS: The data of 316 consecutive patients with isolated TAPVC undergoing repair (January 2010-September 2020) were reviewed. The study setting was a tertiary hospital in southern India that provides subsidized or charitable care. Standard surgical technique was used for repair, circulatory arrest was avoided, and suture-less anastomosis was reserved for small or stenotic pulmonary veins. Surgical and postoperative strategies were directed toward minimizing intensive care unit (ICU) stay. RESULTS: 302 (95.6%) patients were infants and 128 patients (40.5%) were neonates; median weight was 3.3 kg (IQR 2.8-4.0 kg). Obstruction of the TAPVC was seen in 176 patients (56%) and pulmonary hypertension in 278 patients (88%). Seventeen (5.4%) underwent delayed sternal closure. The median postoperative ICU stay was 120 h (IQR 96-192 h), mechanical ventilation was 45 h (IQR 24-82 h), and hospital stay was 13 days (IQR 9-17 days). There were three in-hospital deaths (0.9%). Over a median follow-up period of 53.3 months (IQR 22.9-90.4), pulmonary vein restenosis was seen in 32 patients (10.1%) after a mean of 2.2 months (1-6 months). No perioperative risk factors for restenosis were identified. CONCLUSIONS: Using specific perioperative strategies, it is possible to correct TAPVC with excellent surgical outcomes in low-resource environments. Late pulmonary vein restenosis remains an important complication.


Asunto(s)
Venas Pulmonares , Síndrome de Cimitarra , Constricción Patológica , Humanos , Lactante , Recién Nacido , Venas Pulmonares/anomalías , Venas Pulmonares/cirugía , Estudios Retrospectivos , Factores de Riesgo , Síndrome de Cimitarra/cirugía , Resultado del Tratamiento , Procedimientos Quirúrgicos Vasculares/métodos
2.
Cardiol Young ; 32(2): 185-197, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33843546

RESUMEN

Despite enormous strides in our field with respect to patient care, there has been surprisingly limited dialogue on how to train and educate the next generation of congenital cardiologists. This paper reviews the current status of training and evolving developments in medical education pertinent to congenital cardiology. The adoption of competency-based medical education has been lauded as a robust framework for contemporary medical education over the last two decades. However, inconsistencies in frameworks across different jurisdictions remain, and bridging gaps between competency frameworks and clinical practice has proved challenging. Entrustable professional activities have been proposed as a solution, but integration of such activities into busy clinical cardiology practices will present its own challenges. Consequently, this pivot towards a more structured approach to medical education necessitates the widespread availability of appropriately trained medical educationalists, a development that will better inform curriculum development, instructional design, and assessment. Differentiation between superficial and deep learning, the vital role of rich formative feedback and coaching, should guide our trainees to become self-regulated learners, capable of critical reasoning yet retaining an awareness of uncertainty and ambiguity. Furthermore, disruptive innovations such as "technology enhanced learning" may be leveraged to improve education, especially for trainees from low- and middle-income countries. Each of these initiatives will require resources, widespread advocacy and raised awareness, and publication of supporting data, and so it is especially gratifying that Cardiology in the Young has fostered a progressive approach, agreeing to publish one or two articles in each journal issue in this domain.


Asunto(s)
COVID-19 , Cardiólogos , Cardiología , Educación Médica , Cardiología/educación , Curriculum , Humanos , SARS-CoV-2
3.
J Clin Orthop Trauma ; 25: 101742, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34956831

RESUMEN

Tuberculosis is ancient disease known to mankind. Diagnosis and management of spinal tuberculosis has immensely improved in last few decades. Imaging, particularly MRI, plays important role in diagnosis of spinal tuberculosis and its complications. Four common imaging patterns of spinal tuberculosis include paradiscal type, central type, Anterior subligamentous type, and posterior type. Imaging also plays important role in differentiation of spinal tuberculosis from its mimics, particularly pyogenic spondylitis, and metastasis. Radiological interventions, such as CT guided vertebral biopsy, and percutaneous drainage of cold abscess, are commonly used in management of spinal tuberculosis. Monitoring of therapeutic response is often based on clinical evaluation and imaging. MRI is most common imaging modality used. Signs of healing include bony ankylosis, resolution of marrow edema, decrease in contrast enhancement, and fatty change with in bone marrow. PET CT is recently evaluated for response assessment with promising results. This review summarizes pathophysiology, clinical presentation, imaging features, radiological interventions, and response assessment in spinal tuberculosis.

4.
Cardiol Young ; 31(5): 734-743, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33320078

RESUMEN

OBJECTIVE: This study investigated the impact of the Webinar on deep human learning of CHD. MATERIALS AND METHODS: This cross-sectional survey design study used an open and closed-ended questionnaire to assess the impact of the Webinar on deep learning of topical areas within the management of the post-operative tetralogy of Fallot patients. This was a quantitative research methodology using descriptive statistical analyses with a sequential explanatory design. RESULTS: One thousand-three-hundred and seventy-four participants from 100 countries on 6 continents joined the Webinar, 557 (40%) of whom completed the questionnaire. Over 70% of participants reported that they "agreed" or "strongly agreed" that the Webinar format promoted deep learning for each of the topics compared to other standard learning methods (textbook and journal learning). Two-thirds expressed a preference for attending a Webinar rather than an international conference. Over 80% of participants highlighted significant barriers to attending conferences including cost (79%), distance to travel (49%), time commitment (51%), and family commitments (35%). Strengths of the Webinar included expertise, concise high-quality presentations often discussing contentious issues, and the platform quality. The main weakness was a limited time for questions. Just over 53% expressed a concern for the carbon footprint involved in attending conferences and preferred to attend a Webinar. CONCLUSION: E-learning Webinars represent a disruptive innovation, which promotes deep learning, greater multidisciplinary participation, and greater attendee satisfaction with fewer barriers to participation. Although Webinars will never fully replace conferences, a hybrid approach may reduce the need for conferencing, reduce carbon footprint. and promote a "sustainable academia".


Asunto(s)
COVID-19 , Instrucción por Computador , Educación Médica , Estudios Transversales , Humanos , SARS-CoV-2
5.
Nat Commun ; 11(1): 2339, 2020 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-32393747

RESUMEN

Electron-electron interactions play a critical role in many condensed matter phenomena, and it is tempting to find a way to control them by changing the interactions' strength. One possible approach is to place a studied system in proximity of a metal, which induces additional screening and hence suppresses electron interactions. Here, using devices with atomically-thin gate dielectrics and atomically-flat metallic gates, we measure the electron-electron scattering length in graphene and report qualitative deviations from the standard behavior. The changes induced by screening become important only at gate dielectric thicknesses of a few nm, much smaller than a typical separation between electrons. Our theoretical analysis agrees well with the scattering rates extracted from measurements of electron viscosity in monolayer graphene and of umklapp electron-electron scattering in graphene superlattices. The results provide a guidance for future attempts to achieve proximity screening of many-body phenomena in two-dimensional systems.

6.
Nat Commun ; 10(1): 4008, 2019 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-31488842

RESUMEN

At very small twist angles of ∼0.1°, bilayer graphene exhibits a strain-accompanied lattice reconstruction that results in submicron-size triangular domains with the standard, Bernal stacking. If the interlayer bias is applied to open an energy gap inside the domain regions making them insulating, such marginally twisted bilayer graphene is expected to remain conductive due to a triangular network of chiral one-dimensional states hosted by domain boundaries. Here we study electron transport through this helical network and report giant Aharonov-Bohm oscillations that reach in amplitude up to 50% of resistivity and persist to temperatures above 100 K. At liquid helium temperatures, the network exhibits another kind of oscillations that appear as a function of carrier density and are accompanied by a sign-changing Hall effect. The latter are attributed to consecutive population of the narrow minibands formed by the network of one-dimensional states inside the gap.

7.
Nat Commun ; 10(1): 3334, 2019 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-31350410

RESUMEN

Van der Waals materials and their heterostructures offer a versatile platform for studying a variety of quantum transport phenomena due to their unique crystalline properties and the exceptional ability in tuning their electronic spectrum. However, most experiments are limited to devices that have lateral dimensions of only a few micrometres. Here, we perform magnetotransport measurements on graphene/hexagonal boron-nitride Hall bars and show that wider devices reveal additional quantum effects. In devices wider than ten micrometres we observe distinct magnetoresistance oscillations that are caused by resonant scattering of Landau-quantised Dirac electrons by acoustic phonons in graphene. The study allows us to accurately determine graphene's low energy phonon dispersion curves and shows that transverse acoustic modes cause most of phonon scattering. Our work highlights the crucial importance of device width when probing quantum effects and also demonstrates a precise, spectroscopic method for studying electron-phonon interactions in van der Waals heterostructures.

8.
Science ; 364(6436): 162-165, 2019 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-30819929

RESUMEN

An electrical conductor subjected to a magnetic field exhibits the Hall effect in the presence of current flow. Here, we report a qualitative deviation from the standard behavior in electron systems with high viscosity. We found that the viscous electron fluid in graphene responds to nonquantizing magnetic fields by producing an electric field opposite to that generated by the ordinary Hall effect. The viscous contribution is substantial and identified by studying local voltages that arise in the vicinity of current-injecting contacts. We analyzed the anomaly over a wide range of temperatures and carrier densities and extracted the Hall viscosity, a dissipationless transport coefficient that was long identified theoretically but remained elusive in experiments.

9.
J Indian Soc Pedod Prev Dent ; 37(1): 12-17, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30804302

RESUMEN

Context: The relationship between body mass index (BMI) and dental caries consists of multiple contributing factors. There have been no studies documented in the literature in this part of rural India assessing the prevalence of dental caries in relation to BMI. Hence, an attempt was made to study dental caries in relation to BMI and anthropometric measurements. Aims: The aims were to study dental caries experience in relation to BMI and anthropometric measurements of rural children in Nellore district. Settings and Design: A descriptive cross-sectional study was carried out in Nellore city. Subjects and Methods: A total of 1500 6- and 12-year-old children were examined. Dental caries was examined using the WHO dentition status criteria (1997) and 1-day diet chart was collected from each child followed by collection of anthropometric data. Statistical Analysis Used: Statistical analysis was performed using Chi-square test, Fisher's exact test, and Spearman's correlation test. Results: In the present study, out of all the participants, 59.2% of low weight children, 41.3% of normal weight children, and 25.7% of overweight-obese children were having dental caries. Dental caries was more among low weight children compared to normal weight and overweight-obese children and was statistically significant. Conclusions: All the anthropometric measurements were positively correlated with dental caries except height for age and BMI for age. There was an inverse graded association between the height for age and BMI for age with dental caries in 6- and 12-year-old children.


Asunto(s)
Índice de Masa Corporal , Caries Dental/epidemiología , Factores de Edad , Antropometría , Niño , Estudios Transversales , Caries Dental/etiología , Femenino , Humanos , India/epidemiología , Masculino , Prevalencia , Factores de Riesgo , Población Rural/estadística & datos numéricos , Grosor de los Pliegues Cutáneos , Factores Socioeconómicos , Circunferencia de la Cintura
10.
Proc Natl Acad Sci U S A ; 115(20): 5135-5139, 2018 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-29712870

RESUMEN

Graphene superlattices were shown to exhibit high-temperature quantum oscillations due to periodic emergence of delocalized Bloch states in high magnetic fields such that unit fractions of the flux quantum pierce a superlattice unit cell. Under these conditions, semiclassical electron trajectories become straight again, similar to the case of zero magnetic field. Here, we report magnetotransport measurements that reveal second-, third-, and fourth-order magnetic Bloch states at high electron densities and temperatures above 100 K. The recurrence of these states creates a fractal pattern intimately related to the origin of Hofstadter butterflies. The hierarchy of the fractal states is determined by the width of magnetic minibands, in qualitative agreement with our band-structure calculations.

11.
Congenit Heart Dis ; 13(3): 483-487, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29508558

RESUMEN

BACKGROUND AND OBJECTIVES: The 22q11 deletion syndrome is associated with a wide spectrum of phenotypic features, hence clinical diagnosis is difficult. Individuals with this syndrome are found to have a risk of developing transfusion associated graft-versus-host reaction, if they are given nonirradiated blood. Our aim was to elucidate whether chromosome 22q11 deletion in children with syndromic conotruncal heart defects is associated with platelet abnormality. MATERIALS AND METHODS: The genetic analysis was performed by standard cytogenetic and Fluorescence in situ hybridization technique. The platelet parameters in 39 patients with chromosome 22q11 deletion were compared with 154 cases without deletion. RESULTS: In deletion versus no deletion group, the mean of mean platelet volume (MPV) was 10.5 ± 2.5 vs 7.6 ± 1.5 fL, platelet count was 225 ± 80.7 and 339 ± 127.3 × 10 9 /L and frequency of high MPV was 49% vs 7% (P < .0001). The MPV was associated with a sensitivity of 90.9% and a specificity of 79.6% at a cutoff value of 8.32 fL, (area under the ROC curve 91%). A nonsignificant negative correlation was found between MPV and platelet count (r = -0.152; P = .361) in children with deletion. CONCLUSION: A cutoff value of 8.32 fL for MPV can be an indicator of high risk of chromosome 22q11 deletion in individuals with syndromic conotruncal defects. Individuals with chromosome 22q11 deletion should be given irradiated blood especially during cardiac surgery. Further investigation should clarify the etiology behind variation in frequency of high MPV in different conotruncal lesions.


Asunto(s)
Síndrome de Deleción 22q11/genética , Plaquetas/fisiología , Deleción Cromosómica , Cromosomas Humanos Par 22/genética , Cardiopatías Congénitas/genética , Volúmen Plaquetario Medio/métodos , Síndrome de Deleción 22q11/sangre , Femenino , Cardiopatías Congénitas/sangre , Humanos , Hibridación Fluorescente in Situ , Lactante , Masculino , Estudios Retrospectivos
12.
Science ; 357(6347): 181-184, 2017 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-28706067

RESUMEN

Cyclotron motion of charge carriers in metals and semiconductors leads to Landau quantization and magneto-oscillatory behavior in their properties. Cryogenic temperatures are usually required to observe these oscillations. We show that graphene superlattices support a different type of quantum oscillation that does not rely on Landau quantization. The oscillations are extremely robust and persist well above room temperature in magnetic fields of only a few tesla. We attribute this phenomenon to repetitive changes in the electronic structure of superlattices such that charge carriers experience effectively no magnetic field at simple fractions of the flux quantum per superlattice unit cell. Our work hints at unexplored physics in Hofstadter butterfly systems at high temperatures.

13.
Science ; 351(6277): 1055-8, 2016 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-26912363

RESUMEN

Graphene hosts a unique electron system in which electron-phonon scattering is extremely weak but electron-electron collisions are sufficiently frequent to provide local equilibrium above the temperature of liquid nitrogen. Under these conditions, electrons can behave as a viscous liquid and exhibit hydrodynamic phenomena similar to classical liquids. Here we report strong evidence for this transport regime. We found that doped graphene exhibits an anomalous (negative) voltage drop near current-injection contacts, which is attributed to the formation of submicrometer-size whirlpools in the electron flow. The viscosity of graphene's electron liquid is found to be ~0.1 square meters per second, an order of magnitude higher than that of honey, in agreement with many-body theory. Our work demonstrates the possibility of studying electron hydrodynamics using high-quality graphene.

14.
Oral Health Dent Manag ; 13(1): 49-53, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24603916

RESUMEN

BACKGROUND: Nutrition is one of the important components of health, functional independence and quality of life in elderly population. In this age group, malnutrition is common and the risk of malnutrition increases with the advancing age. Nutritional status acts as a modifying factor in the development of many oral diseases. AIM: To assess the relationship of salivary factors, dental caries and nutritional status among institutionalized elderly people. MATERIALS AND METHODS: A cross-sectional descriptive study was conducted in three old age homes in Nellore city. All the institutionalized elderly aged 50 years and above were included for the study. Pearson co-relation was done to know the relationship of malnutrition, salivary parameters and dental caries experience. RESULTS: A total of 81 subjects with a mean age of 70.12 ± 7.32 yrs participated in the study. 43% of subjects were at risk of malnourishment and 14% were malnourished. Analysis of salivary parameters in relation to nutritional status of subjects revealed that salivary flow rate decreased among malnourished subjects (0.50 ± 0.100) when compared to well-nourished subjects (0.93 ± 0.260). DMFT scores increased in subjects who were malnourished (12.45 ± 5.574) compared to well-nourished subjects (6.34 ± 5.765). Co-relation of nutritional status with salivary parameters and caries experience revealed a positive co-relation between nutritional status and salivary flow rate, where as a negative co-relation was observed between caries experience. CONCLUSION: Prevalence of malnourishment was 14% among the institutionalized elderly. All of them had lower salivary flow rate, buffering capacity and pH with increased caries experience.

15.
J Am Coll Cardiol ; 62(25 Suppl): D34-41, 2013 Dec 24.
Artículo en Inglés | MEDLINE | ID: mdl-24355639

RESUMEN

In 1998, a clinical classification of pulmonary hypertension (PH) was established, categorizing PH into groups which share similar pathological and hemodynamic characteristics and therapeutic approaches. During the 5th World Symposium held in Nice, France, in 2013, the consensus was reached to maintain the general scheme of previous clinical classifications. However, modifications and updates especially for Group 1 patients (pulmonary arterial hypertension [PAH]) were proposed. The main change was to withdraw persistent pulmonary hypertension of the newborn (PPHN) from Group 1 because this entity carries more differences than similarities with other PAH subgroups. In the current classification, PPHN is now designated number 1. Pulmonary hypertension associated with chronic hemolytic anemia has been moved from Group 1 PAH to Group 5, unclear/multifactorial mechanism. In addition, it was decided to add specific items related to pediatric pulmonary hypertension in order to create a comprehensive, common classification for both adults and children. Therefore, congenital or acquired left-heart inflow/outflow obstructive lesions and congenital cardiomyopathies have been added to Group 2, and segmental pulmonary hypertension has been added to Group 5. Last, there were no changes for Groups 2, 3, and 4.


Asunto(s)
Hipertensión Pulmonar/clasificación , Hipertensión Pulmonar/diagnóstico , Anemia Hemolítica/clasificación , Anemia Hemolítica/diagnóstico , Anemia Hemolítica/epidemiología , Animales , Enfermedades del Tejido Conjuntivo/clasificación , Enfermedades del Tejido Conjuntivo/diagnóstico , Enfermedades del Tejido Conjuntivo/epidemiología , Cardiopatías Congénitas/clasificación , Cardiopatías Congénitas/diagnóstico , Cardiopatías Congénitas/epidemiología , Humanos , Hipertensión Pulmonar/epidemiología
16.
Indian J Nucl Med ; 25(4): 168-70, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21712913

RESUMEN

Thyroid carcinoma metastatic to the paranasal sinuses is extremely rare. We report a case of follicular thyroid carcinoma metastatic to the right maxillary sinus, with extension into the right side of the hard palate in a young lady. A radioactive iodine-131 (I-131) scan post total thyroidectomy revealed 0.8% uptake in the neck; the whole body scan revealed a functioning metastasis in the region of the right maxillary antrum. Pathological confirmation of metastasis was done by correlating the fine needle aspirate cytology with the thyroidectomy histology. The patient initially received 40 Gy of external beam radiotherapy, subsequently, she received 110 millicuries of I-131, followed by 50 millicuries 6 months later. She continues to be on follow-up on Eltroxin™ suppression and has remained disease free for the past 4 ½ years.

19.
Ann Pediatr Cardiol ; 2(2): 177-8, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20808638

RESUMEN

Pulmonary arteriovenous malformation (PAVM) is common after cavopulmonary anastomosis. PAVMs appear on chest X-ray film as diffuse opacity in one or both lungs. Angiographically, it appears as spidery diffuse vascularity with near simultaneous opacification of pulmonary arteries and veins.

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