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1.
J Sports Sci ; 37(13): 1521-1533, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30810467

RESUMEN

Improvements in running economy (RE) are thought to lead to improvements in running performance (P). Multiple interventions have been designed with the aim of improving RE in middle and long-distance runners. The aim of this study was to assess the effect of interventions of at least 2-weeks' duration on RE and P and to determine whether there is a relationship between changes in RE (ΔRE) and changes in running performance (ΔP). A database search was carried out in Web of Science, Scopus and SPORTDiscus. In accordance with a PRISMA checklist 10 studies reporting 12 comparisons between interventions and controls were included in the review. There was no correlation between percentage ΔRE and percentage ΔP (r = 0.46, P = 0.936, 12 comparisons). There was a low risk of reporting bias but an unclear risk of bias for other items. Meta-analyses found no statistically significant differences between interventions and controls for RE (SMD (95% CI) = -0.37 (-1.43, 0.69), 204 participants, p = 0.49) or for P (SMD (95% CI) = -0.65 (-26.02, 24.72, 204 participants, p = 0.99). There is a need for studies of greater statistical power, methodological quality, duration and homogeneity of intervention and population. Standardised measures of performance and greater control over non-intervention training are also required.


Asunto(s)
Rendimiento Atlético/fisiología , Metabolismo Energético , Acondicionamiento Físico Humano/métodos , Carrera/fisiología , Humanos , Consumo de Oxígeno , Intercambio Gaseoso Pulmonar , Factores de Tiempo
4.
BMC Public Health ; 16(1): 821, 2016 08 18.
Artículo en Inglés | MEDLINE | ID: mdl-27538455

RESUMEN

BACKGROUND: Alcohol plays a complex role in society. A recent study showed that over half of Irish adults drink hazardously. Adolescents report increased levels of alcohol consumption. Previous research has inferred the influence of the parent on their adolescent. Thus, the aim of the current study was to investigate the association between adolescent alcohol consumption and their parent's consumption pattern and attitude toward alcohol use in Southern Ireland. METHODS: A cross-sectional survey was undertaken in November 2014. This involved distributing a survey to adolescents (n = 982) in their final two years of second level education and at least one of their parents from a local electorate area in Southern Ireland. This survey included: alcohol use, self- reported height and weight, smoking status, mental health and well-being along with attitudinal questions. Chi-square tests and multivariate logistic regression were utilised. RESULTS: A 37 % response rate was achieved. Over one-third (34.2 %) of adolescents and 47 % of parents surveyed reported hazardous drinking. Over 90 % of parents disagreed with allowing their adolescent to get drunk and rejected the idea that getting drunk is part of having fun as an adolescent. The majority (79.5 %) of parents surveyed believed that their alcohol consumption pattern set a good example for their adolescent. Multivariate logistic regression highlights the association between adolescent hazardous alcohol consumption and hazardous drinking by the father. Furthermore either parent permitting their adolescent to drink alcohol on special occasions was associated with hazardous alcohol consumption in the adolescent. CONCLUSION: The findings of this research notes a liberal attitude to alcohol and increased levels of consumption by the parent are linked to hazardous adolescent drinking behaviour. Future action plans aimed at combatting adolescent hazardous alcohol consumption should also be aimed at tackling parents' attitudes towards and consumption of alcohol.


Asunto(s)
Conducta del Adolescente/psicología , Consumo de Bebidas Alcohólicas/psicología , Actitud , Padres/psicología , Consumo de Alcohol en Menores/psicología , Adolescente , Adulto , Intoxicación Alcohólica/psicología , Estudios Transversales , Conducta Peligrosa , Femenino , Humanos , Irlanda , Modelos Logísticos , Masculino , Encuestas y Cuestionarios , Adulto Joven
5.
J Card Surg ; 31(2): 103-5, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26748778

RESUMEN

BACKGROUND: Repair of unroofed coronary sinus defect in the presence of left superior vena cava is challenging and requires prosthetic graft material to redirect flow to the right atrium. This may potentially cause a supra-mitral gradient or pulmonary venous obstruction. METHODS: Three patients with unroofed coronary sinus in the presence of a left superior vena cava (LSVC) underwent modified cavo-atrial anastomosis (Warden technique) to achieve reimplantation of the LSVC in a retro-aortic fashion to the right atrial appendage. RESULTS: Three patients recovered well with no evidence of an intracardiac shunt. Postoperative echocardiography demonstrated normal venous flows in the LSVC. CONCLUSION: This modified technique offers correction of this systemic venous anomaly without the need for any additional graft material.


Asunto(s)
Implantación de Prótesis Vascular/métodos , Procedimientos Quirúrgicos Cardiovasculares/métodos , Seno Coronario/anomalías , Vena Cava Superior/anomalías , Anastomosis Quirúrgica/métodos , Preescolar , Seno Coronario/cirugía , Atrios Cardíacos/cirugía , Humanos , Lactante , Masculino , Enfermedad Veno-Oclusiva Pulmonar/etiología , Estudios Retrospectivos , Resultado del Tratamiento , Vena Cava Superior/trasplante
6.
Cardiol Young ; 24(3): 478-84, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23732114

RESUMEN

We determined the relationship between aortic arch anatomy in tetralogy of Fallot with pulmonary stenosis and chromosomal or genetic abnormality, by performing analysis of 257 consecutive patients undergoing surgical repair from January, 2003 to March, 2011. Chromosomal or genetic abnormality was identified in 49 of the 257 (19%) patients. These included trisomy 21 (n = 14); chromosome 22q11.2 deletion (n = 16); other chromosomal abnormalities (n = 9); CHARGE (n = 2); Pierre Robin (n = 2); and Kabuki, Alagille, Holt-Oram, Kaufman McKusick, Goldenhar, and PHACE (n = 1 each). Aortic anatomy was classified as left arch with normal branching, right arch with mirror image branching, left arch with aberrant right subclavian artery, or right arch with aberrant left subclavian artery. Associated syndromes occurred in 33 of 203 (16%) patients with left arch and normal branching (odds ratio 1); three of 36 (8%) patients with right arch and mirror image branching (odds ratio 0.4, 95% confidence interval 0.1-1.6); seven of eight (88%) patients with left arch and aberrant right subclavian artery (odds ratio 36, 95% confidence interval 4-302); and six of 10 (60%) patients with right arch and aberrant left subclavian artery (odds ratio 8, 95% confidence interval 2-26). Syndromes were present in 13 of 18 (72%) patients with either right or left aberrant subclavian artery (odds ratio 15, 95% confidence interval 4-45). Syndromes in patients with an aberrant subclavian artery included trisomy 21 (n = 4); chromosome 22q11.2 deletion (n = 5); and Holt-Oram, PHACE, CHARGE, and chromosome 18p deletion (n = 1 each). Aberrant right or left subclavian artery in tetralogy of Fallot with pulmonary stenosis is associated with an increased incidence of chromosomal or genetic abnormality, whereas right aortic arch with mirror image branching is not. The assessment of aortic arch anatomy at prenatal diagnosis can assist counselling.


Asunto(s)
Aneurisma/complicaciones , Aneurisma/genética , Anomalías Cardiovasculares/complicaciones , Anomalías Cardiovasculares/genética , Aberraciones Cromosómicas , Trastornos de Deglución/complicaciones , Trastornos de Deglución/genética , Estenosis de la Válvula Pulmonar/complicaciones , Estenosis de la Válvula Pulmonar/genética , Arteria Subclavia/anomalías , Tetralogía de Fallot/complicaciones , Tetralogía de Fallot/genética , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios Retrospectivos
8.
Pediatr Cardiol ; 34(7): 1567-76, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23479308

RESUMEN

In most newborns with left heart obstruction, the choice between a single-ventricle or biventricular management pathway is clear. However, in some neonates with a "borderline" left ventricle, this decision is difficult. Existing criteria do not reliably identify neonates who will have a good long-term outlook after biventricular repair (BVR). The objective of this study was prospective assessment of the outcome after BVR for newborns in whom the left ventricle (LV) was considered "borderline" by an expert group. This study was a prospective follow-up evaluation of neonates with obstructive left heart disease related to a "borderline" LV who underwent biventricular management between January 2005 and April 2011. Of 154 neonates who required intervention for left heart obstruction, 13 (7.8 %) met the echocardiographic (echo) inclusion criteria. At the first and last echo, the z-scores were respectively -1.76 ± 1.37 and -0.66 ± 1.47 (p = 0.013) for the mitral valve, -1.02 ± 1.57 and -0.23 ± 1.78 (p = 0.056) for the aortic valve, and 13.77 ± 5.8 and 20.85 ± 8.9 ml/m(2) (p = 0.006) for the LV end-diastolic volume. At this writing, all 12 survivors are clinically well. However, LV diastolic dysfunction and pulmonary artery hypertension was present in 5 (36 %) of 12 patients. Endocardial fibroelastosis (EFE) was detected in five patients at the last follow-up echo, but only in two patients preoperatively. Cardiac magnetic resonance imaging did not confirm EFE in any of assessed patients. The study authors could not reliably predict the outcome after BVR for neonates with left heart obstruction and a "borderline" LV. The presence of EFE with consequent diastolic dysfunction is more important than LV volume in determining the outcome. Prospective identification of EFE remains challenging.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Ecocardiografía/métodos , Ventrículos Cardíacos/diagnóstico por imagen , Síndrome del Corazón Izquierdo Hipoplásico/diagnóstico por imagen , Función Ventricular Izquierda/fisiología , Toma de Decisiones , Femenino , Estudios de Seguimiento , Ventrículos Cardíacos/fisiopatología , Ventrículos Cardíacos/cirugía , Humanos , Síndrome del Corazón Izquierdo Hipoplásico/fisiopatología , Síndrome del Corazón Izquierdo Hipoplásico/cirugía , Recién Nacido , Masculino , Pronóstico , Estudios Prospectivos
9.
Cardiovasc Intervent Radiol ; 46(1): 136-141, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36261506

RESUMEN

PURPOSE: Portal vein thrombus (PVT) can worsen portal hypertension and hepatic decompensation in patients with cirrhosis and impact liver transplant outcomes. This retrospective case series describes large bore mechanical thrombectomy of PVT with the Inari FlowTriever device during, or remotely after, transjugular intrahepatic portosystemic shunt (TIPS) placement. MATERIALS AND METHODS: Ten patients with PVT were treated with large bore thrombectomy. All patients had underlying cirrhosis, complicated by portal hypertension with acute/subacute PVT. Thrombectomy was performed either with TIPS placement, or via a previously placed thrombosed shunt. Median time from TIPS placement to thrombectomy was 3 years. RESULTS: Thrombectomy was technically successful in all patients with a majority achieving complete resolution of PVT in a single session. During mean follow-up of 13.3 months, all patients achieved complete resolution of PVT without recurrence. CONCLUSION: Large bore mechanical thrombectomy together with TIPS is a feasible and effective treatment of acute/subacute PVT in cirrhotic patients with portal hypertension, often with complete resolution in a single session.


Asunto(s)
Hipertensión Portal , Derivación Portosistémica Intrahepática Transyugular , Trombosis , Trombosis de la Vena , Humanos , Vena Porta/cirugía , Vena Porta/patología , Derivación Portosistémica Intrahepática Transyugular/efectos adversos , Estudios Retrospectivos , Trombosis de la Vena/diagnóstico por imagen , Trombosis de la Vena/cirugía , Trombosis de la Vena/complicaciones , Trombosis/complicaciones , Trombectomía/efectos adversos , Hipertensión Portal/complicaciones , Hipertensión Portal/cirugía , Cirrosis Hepática/etiología , Resultado del Tratamiento
10.
Cardiol Young ; 22(2): 178-83, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21851759

RESUMEN

OBJECTIVE: To assess the cardiac catheterisation findings of all children in whom cardiac magnetic resonance imaging found great artery stenosis. METHODS: We conducted a retrospective analysis of all 45 consecutive children with congenital cardiac disease who were undergoing cardiac catheterisation for intervention on cardiac magnetic resonance-defined great vessel stenosis, between January, 2006 and August, 2008. RESULTS: Following cardiac magnetic resonance, 60 significant great vessel stenoses were identified and referred to cardiac catheterisation for intervention. All patients were catheterised within a median and interquartile range of 84 and 4-149 days, respectively, of cardiac magnetic resonance. At cardiac catheterisation, the children were aged 11.5 years - with an interquartile range of 3.8-16.9 years - and weighed 34 kilograms - with an interquartile range of 15-56 kilograms. Comparing cardiac magnetic resonance and cardiac catheterisation findings, 53 (88%) findings were concordant and seven were discordant. In six of seven (86%) discordant observations, cardiac magnetic resonance defined moderate-severe great vessel stenosis - involving three branch pulmonary arteries and three aortas. This was not confirmed by cardiac catheterisation, which revealed mild stenoses and haemodynamic gradients insufficient for intervention. In one patient, a mild, proximal right pulmonary artery narrowing was found at cardiac catheterisation, which was not mentioned in the cardiac magnetic resonance report. There was no difference between discordant and concordant groups on the basis of patient age, weight, interval between cardiac magnetic resonance and cardiac catheterisation, or type of lesion. CONCLUSION: Invasive assessment confirmed cardiac magnetic resonance-diagnosed great vessel stenosis in the majority of this cohort. The predominant discordant finding was lower catherisation gradient than predicted by morphologic and functional cardiac magnetic resonance assessment. Flow volume diversion - for example, unilateral pulmonary artery stenosis - and anaesthetic effects may account for some differences. Prospective refinement of cardiac magnetic resonance and interventional data may further improve the validity of non-invasive imaging thresholds for intervention.


Asunto(s)
Estenosis de la Válvula Aórtica/terapia , Cateterismo Cardíaco/métodos , Constricción Patológica/terapia , Imagen por Resonancia Magnética/métodos , Arteria Pulmonar/patología , Adolescente , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/diagnóstico , Niño , Preescolar , Constricción Patológica/complicaciones , Constricción Patológica/diagnóstico , Cardiopatías Congénitas/complicaciones , Humanos , Estudios Retrospectivos
11.
iScience ; 25(10): 105153, 2022 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-36204263

RESUMEN

Carbon capture from both stationary emitters and dilute sources is critically needed to mitigate climate change. Carbon dioxide separation methods driven by electrochemical stimuli show promise to sidestep the high-energy penalty and fossil-fuel dependency associated with the conventional pressure and temperature swings. Compared with a batch process, electrochemically mediated carbon capture (EMCC) operating in a continuous flow mode offers greater design flexibility. Therefore, this review introduces key advances in continuous flow EMCC for point source, air, and ocean carbon captures. Notably, the main challenges and future research opportunities for practical implementation of continuous flow EMCC processes are discussed from a multi-scale perspective, from molecules to electrochemical cells and finally to separation systems.

12.
PLoS One ; 17(5): e0267668, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35522608

RESUMEN

BACKGROUND: Hand-wrist bone age assessment methods are not possible on typical EOS 2D/3D images without body position modifications that may affect spinal position. We aimed to identify and assess lesser known bone age assessment alternatives that may be applied retrospectively and without the need for extra imaging. MATERIALS AND METHODS: After review of 2857 articles, nine bone age methods were selected and applied retrospectively in pilot study (thirteen individuals), followed by evaluation of EOS images of 934 4-24-year-olds. Difficulty of assessment and time taken were recorded, and reliability calculated. RESULTS: Five methods proved promising after pilot study. Risser 'plus' could be applied with no difficulty in 89.5% of scans (836/934) followed by the Oxford hip method (78.6%, 734/934), cervical (79.0%, 738/934), calcaneus (70.8%, 669/934) and the knee (68.2%, 667/934). Calcaneus and cervical methods proved to be fastest at 17.7s (95% confidence interval, 16.0s to 19.38s & 26.5s (95% CI, 22.16s to 30.75s), respectively, with Oxford hip the slowest at 82.0 s (95% CI, 76.12 to 87.88s). Difficulties included: regions lying outside of the image-assessment was difficult or impossible in upper cervical vertebrae (46/934 images 4.9%) and calcaneus methods (144/934 images, 15.4%); position: lower step length was associated with difficult lateral knee assessment & head/hand position with cervical evaluation; and resolution: in the higher stages of the hip, calcaneal and knee methods. CONCLUSIONS: Hip, iliac crest and cervical regions can be assessed on the majority of EOS scans and may be useful for retrospective application. Calcaneus evaluation is a simple and rapidly applicable method that may be appropriate if consideration is given to include full imaging of the foot.


Asunto(s)
Vértebras Cervicales , Articulación de la Rodilla , Humanos , Proyectos Piloto , Reproducibilidad de los Resultados , Estudios Retrospectivos
13.
Front Immunol ; 13: 890517, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35711466

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its associated symptoms, named coronavirus disease 2019 (COVID-19), have rapidly spread worldwide, resulting in the declaration of a pandemic. When several countries began enacting quarantine and lockdown policies, the pandemic as it is now known truly began. While most patients have minimal symptoms, approximately 20% of verified subjects are suffering from serious medical consequences. Co-existing diseases, such as cardiovascular disease, cancer, diabetes, and others, have been shown to make patients more vulnerable to severe outcomes from COVID-19 by modulating host-viral interactions and immune responses, causing severe infection and mortality. In this review, we outline the putative signaling pathways at the interface of COVID-19 and several diseases, emphasizing the clinical and molecular implications of concurring diseases in COVID-19 clinical outcomes. As evidence is limited on co-existing diseases and COVID-19, most findings are preliminary, and further research is required for optimal management of patients with comorbidities.


Asunto(s)
COVID-19 , COVID-19/epidemiología , Control de Enfermedades Transmisibles , Humanos , Pandemias , Cuarentena , SARS-CoV-2
14.
Global Spine J ; 12(2): 244-248, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32935571

RESUMEN

STUDY DESIGN: Retrospective cross-sectional study. OBJECTIVES: It is generally believed that the apical vertebra has the largest axial rotation in adolescent idiopathic scoliosis. We investigated the relationship between apical axial vertebral rotation (apicalAVR) and maximal axial vertebral rotation (maxAVR) in both major and minor curves using biplanar stereo-imaging. METHODS: EOS 2D/3D biplanar radiograph images were collected from 332 patients with adolescent idiopathic scoliosis (Cobb angle range 10°-122°, mean age 14.7 years). Based on the X-ray images, with the help of 3D full spine reconstructions Cobb angle, curvature level, apicalAVR and maxAVR were determined. These parameters were also determined for minor curves in Lenke 2, 3, 4, 6 type patients. Maximal thoracic rotation and maximal thoracolumbar/lumbar rotation were calculated. Statistical analysis was performed with descriptive statistics, Shapiro-Wilk test, and Wilcoxon signed-rank test. RESULTS: The apical vertebrae were the most rotated vertebra in only 40.4% of the major curves, and 31.7% in minor curves. MaxAVR significantly exceeded apicalAVR values in the major curves (P < .001) as well as in minor curves (P < .001). The 2 parameters differed significantly in each severity group and Lenke type. CONCLUSIONS: The apical vertebrae were not the most rotated vertebra in more than half of cases investigated indicating that apicalAVR and maxAVR should be considered as 2 distinct parameters, of which maxAVR fully describes the axial dimension of scoliosis. Furthermore, the substitution of maxAVR for the apicalAVR should be especially avoided in double and triple curves, as the apical vertebra was even less commonly the most rotated in minor curves.

15.
Antibodies (Basel) ; 11(2)2022 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-35645208

RESUMEN

Questions and concerns regarding the efficacy and immunogenicity of coronavirus disease 2019 (COVID-19) vaccines have plagued scientists since the BNT162b2 mRNA vaccine was introduced in late 2020. As a result, decisions about vaccine boosters based on breakthrough infection rates and the decline of antibody titers have commanded worldwide attention and research. COVID-19 patients have displayed continued severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-spike-protein-specific antibodies and neutralizing antibodies in longitudinal studies; in addition, cytokine activation has been detected at early steps following SARS-CoV-2 infection. Epitopes that are highly reactive and can mediate long-term antibody responses have been identified at the spike and ORF1ab proteins. The N-terminal domain of the S1 and S2 subunits is the location of important SARS-CoV-2 spike protein epitopes. High sequence identity between earlier and newer variants of SARS-CoV-2 and different degrees of sequence homology among endemic human coronaviruses have been observed. Understanding the extent and duration of protective immunity is consequential for determining the course of the COVID-19 pandemic. Further knowledge of memory responses to different variants of SARS-CoV-2 is needed to improve the design of the vaccine.

16.
J Pediatr Orthop B ; 30(4): 337-345, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32694432

RESUMEN

The aim of the study was to assess the correlation between femoral neck-shaft angles (NSAs) and skeletal maturity in EOS reconstructions from a large population of children. Full-body three-dimensional (3D) reconstructions were generated from 1005 children and young adults (4-24 years old; 449 male, 556 female) using the EOS three-dimensional/3D scanner, with images taken during routine clinical practice. The true NSAs were measured and assessed for correlation with individuals' chronological age and bone age, based on cervical vertebral morphology. Statistical analysis was performed using Spearman correlation, independent t-test and multiple linear regression. NSAs of older and younger individuals within each bone age group and chronological age were further assessed by t-test. NSA values fell from mean 131.89° ± 6.07° at 4 years old to 128.85° ± 4.46° at the age of 16, with only minor decreases thereafter. Significantly higher NSAs (3.16° and 4.45°, respectively) were found in those with a bone age advanced or delayed by more two or more stages compared to their peers of the same chronological age (P < 0.001; P < 0.001). Similarly, within most bone age stages, individuals of advanced or delayed chronological age exhibited elevated values (mean difference ranged from 2.9° to 8.9°, P < 0.05). Incorporation of bone age assessment into proximal femoral evaluation allowed identification of 'fast maturing' and 'slow maturing' sub-categories in developing children, with different expected NSAs. The earlier ossification seen in faster-maturing individuals may lead to the NSA becoming fixed in a more immature valgus conformation.


Asunto(s)
Cuello Femoral , Procedimientos de Cirugía Plástica , Adolescente , Adulto , Niño , Preescolar , Diáfisis , Femenino , Fémur/diagnóstico por imagen , Cuello Femoral/diagnóstico por imagen , Humanos , Imagenología Tridimensional , Masculino , Adulto Joven
17.
ACS Appl Mater Interfaces ; 13(17): 20260-20268, 2021 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-33886258

RESUMEN

Three-dimensional (3D) printed, hierarchically porous nickel molybdenum (NiMo) electrocatalysts were synthesized and evaluated in a flow-through configuration for the hydrogen evolution reaction (HER) in 1.0 M KOH(aq) in a simple electrochemical H-cell. 3D NiMo electrodes possess hierarchically porous structures because of the resol-based aerogel precursor, which generates superporous carbon aerogel as a catalyst support. Relative to a traditional planar electrode configuration, the flow-through configuration allowed efficient removal of the hydrogen bubbles from the catalyst surface, especially at high operating current densities, and significantly decreased the overpotentials required for HER. An analytical model that accounted for the electrokinetics of HER as well as the mass transport with or without the flow-through configuration was developed to quantitatively evaluate voltage losses associated with kinetic overpotentials and ohmic resistance due to bubble formation in the porous electrodes. The chemical composition, electrochemical surface area (ECSA), and roughness factor (RF) were also systematically studied to assess the electrocatalytic performance of the 3D printed, hierarchically porous NiMo electrodes. An ECSA of 25163 cm2 was obtained with the highly porous structures, and an average overpotential of 45 mV at 10 mA cm-2 was achieved over 24 h by using the flow-through configuration. The flow-through configuration evaluated in the simple H-cell achieved high electrochemical accessible surface areas for electrochemical reactions and provided useful information for adaption of the porous electrodes in flow cells.

18.
PLoS Comput Biol ; 5(4): e1000345, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19360132

RESUMEN

When coordinating movements, the nervous system often has to decide how to distribute work across a number of redundant effectors. Here, we show that humans solve this problem by trying to minimize both the variability of motor output and the effort involved. In previous studies that investigated the temporal shape of movements, these two selective pressures, despite having very different theoretical implications, could not be distinguished; because noise in the motor system increases with the motor commands, minimization of effort or variability leads to very similar predictions. When multiple effectors with different noise and effort characteristics have to be combined, however, these two cost terms can be dissociated. Here, we measure the importance of variability and effort in coordination by studying how humans share force production between two fingers. To capture variability, we identified the coefficient of variation of the index and little fingers. For effort, we used the sum of squared forces and the sum of squared forces normalized by the maximum strength of each effector. These terms were then used to predict the optimal force distribution for a task in which participants had to produce a target total force of 4-16 N, by pressing onto two isometric transducers using different combinations of fingers. By comparing the predicted distribution across fingers to the actual distribution chosen by participants, we were able to estimate the relative importance of variability and effort of 1:7, with the unnormalized effort being most important. Our results indicate that the nervous system uses multi-effector redundancy to minimize both the variability of the produced output and effort, although effort costs clearly outweighed variability costs.


Asunto(s)
Dedos/fisiología , Modelos Neurológicos , Destreza Motora/fisiología , Movimiento/fisiología , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Equilibrio Postural/fisiología , Simulación por Computador , Humanos , Músculo Esquelético/inervación , Esfuerzo Físico/fisiología , Análisis y Desempeño de Tareas
19.
Nat Commun ; 11(1): 4412, 2020 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-32887872

RESUMEN

Capture and conversion of CO2 from oceanwater can lead to net-negative emissions and can provide carbon source for synthetic fuels and chemical feedstocks at the gigaton per year scale. Here, we report a direct coupled, proof-of-concept electrochemical system that uses a bipolar membrane electrodialysis (BPMED) cell and a vapor-fed CO2 reduction (CO2R) cell to capture and convert CO2 from oceanwater. The BPMED cell replaces the commonly used water-splitting reaction with one-electron, reversible redox couples at the electrodes and demonstrates the ability to capture CO2 at an electrochemical energy consumption of 155.4 kJ mol-1 or 0.98 kWh kg-1 of CO2 and a CO2 capture efficiency of 71%. The direct coupled, vapor-fed CO2R cell yields a total Faradaic efficiency of up to 95% for electrochemical CO2 reduction to CO. The proof-of-concept system provides a unique technological pathway for CO2 capture and conversion from oceanwater with only electrochemical processes.

20.
BJR Case Rep ; 5(2): 20180109, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31501708

RESUMEN

The purpose of the study was to investigate and review the multimodality imaging findings of gastric lipomas. Seven patients with gastric lipomas identified by CT imaging at a single institution between 2003 and 2017 were retrospectively evaluated. Patient demographics, clinical presentation, non-invasive imaging, endoscopic, and pathological findings were recorded.The most common location for gastric lipoma was the gastric antrum (3/7). The mean lipoma size was 2.7 cm ± 0.8 cm. Six out of seven lipomas demonstrated homogenous fat attenuation with mean Hounsfield units (HU) between -80 and -120. A single lipoma measuring -50 HU demonstrated soft tissue septations. In addition to routine CT and MRI, gastric lipomas were diagnosed on the low-dose CT protocols such as coronary calcium scoring, renal stone, and positron emission tomography-CT (PET-CT). Our CT findings corroborate those reported previously. Soft tissue septations visualized in one lesion likely represented post-biopsy changes, adding this etiology to a differential which previously included only ulceration. Cases characterized by MRI are rare in the literature, and our study provides one such example. To our knowledge this study represents the first documentation of gastric lipomas on PET-CT and other low-dose CT imaging protocols.

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