Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Am J Physiol Cell Physiol ; 323(5): C1374-C1392, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-36121129

RESUMEN

Chronic obstructive pulmonary disease (COPD) is a leading cause of death and cigarette smoke is the main risk factor. Detecting its earliest stages and preventing a decline in lung function are key goals. The pathogenesis of COPD is complex but has some similarities to cystic fibrosis (CF), a disease caused by mutations in the cftr gene. CF leads to chronic inflammation, abnormal mucus, and cycles of infection. Cigarette smoke exposure also causes CFTR dysfunction, and it is probably not a coincidence that inflammation, mucus obstruction, and infections are also characteristics of COPD, although the exacerbations can be quite different. We review here the acute effects of cigarette smoke on CFTR function and its potential role in COPD. Understanding CFTR regulation by cigarette smoke may identify novel drug targets and facilitate the development of therapeutics that reduce the progression and severity of COPD.


Asunto(s)
Fumar Cigarrillos , Fibrosis Quística , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Fumar Cigarrillos/efectos adversos , Enfermedad Pulmonar Obstructiva Crónica/genética , Fibrosis Quística/genética , Nicotiana , Inflamación
2.
JAMA ; 326(3): 250-256, 2021 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-34283184

RESUMEN

Importance: Medical debt is an increasing concern in the US, yet there is limited understanding of the amount and distribution of medical debt, and its association with health care policies. Objective: To measure the amount of medical debt nationally and by geographic region and income group and its association with Medicaid expansion under the Affordable Care Act. Design, Setting, and Participants: Data on medical debt in collections were obtained from a nationally representative 10% panel of consumer credit reports between January 2009 and June 2020 (reflecting care provided prior to the COVID-19 pandemic). Income data were obtained from the 2014-2018 American Community Survey. The sample consisted of 4.1 billion person-month observations (nearly 40 million unique individuals). These data were used to estimate the amount of medical debt (nationally and by geographic region and zip code income decile) and to examine the association between Medicaid expansion and medical debt (overall and by income group). Exposures: Geographic region (US Census region), income group (zip code income decile), and state Medicaid expansion status. Main Outcomes and Measures: The stock (all unpaid debt listed on credit reports) and flow (new debt listed on credit reports during the preceding 12 months) of medical debt in collections that can be collected on by debt collectors. Results: In June 2020, an estimated 17.8% of individuals had medical debt (13.0% accrued debt during the prior year), and the mean amount was $429 ($311 accrued during the prior year). The mean stock of medical debt was highest in the South and lowest in the Northeast ($616 vs $167; difference, $448 [95% CI, $435-$462]) and higher in poor than in rich zip code income deciles ($677 vs $126; difference, $551 [95% CI, $520-$581]). Between 2013 and 2020, the states that expanded Medicaid in 2014 experienced a decline in the mean flow of medical debt that was 34.0 percentage points (95% CI, 18.5-49.4 percentage points) greater (from $330 to $175) than the states that did not expand Medicaid (from $613 to $550). In the expansion states, the gap in the mean flow of medical debt between the lowest and highest zip code income deciles decreased by $145 (95% CI, $95-$194) while the gap increased by $218 (95% CI, $163-$273) in the nonexpansion states. Conclusions and Relevance: This study provides an estimate of the amount of medical debt in collections in the US based on consumer credit reports from January 2009 to June 2020, reflecting care delivered prior to the COVID-19 pandemic, and suggests that the amount of medical debt was highest among individuals living in the South and in lower-income communities. However, further study is needed regarding debt related to COVID-19.


Asunto(s)
Financiación Personal/economía , Gastos en Salud/estadística & datos numéricos , Disparidades en Atención de Salud/economía , Humanos , Renta , Seguro de Salud/economía , Medicaid/economía , Pacientes no Asegurados , Determinantes Sociales de la Salud , Estados Unidos
3.
Microb Pathog ; 142: 104036, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-32017958

RESUMEN

BACKGROUND: In the immunocompromised conditions following renal transplantation, BK virus can reactivate and cause BK virus associated nephropathy (BKVN). Increased BK viral loads and extended duration of infection have been linked to development of BKVN. The aim of this study was to observe the incidence of BKV infection and BKVN, and kinetics of infection and disease in renal transplantation recipients. METHODS: From 2014 to 2018, we conducted a longitudinal cohort observational study of 139 renal transplantation patients treated at a single clinic. Quantitative PCR assay was conducted to assess longitudinal BK viral loads. Analysis of patient clinical characteristics was performed to determine risk factors for BKV infection and associated disease. RESULTS: Of our cohort, 29 (20.9%) patients developed high BK viremia, and 7 (5.0%) developed biopsy-confirmed BKVN. Clinical parameters associated with diabetes (FBS, HbA1c) and hyperlipidemia (TG, TC, LDL-C) were found to be correlated with development of high BK viremia or BKVN. In 3 of 4 patients receiving intravenous immunoglobulin (IVIG) treatment, BK viral loads were reduced by at least 1 log within 2-3 months of administration. Significant differences were measured in BK viral loads and kidney function between BK viremic patients and BKVN patients by 3-9 months post-transplantation. CONCLUSIONS: We identified diabetes and hyperlipidemia as potential risk factors for development of high BK viremia and/or BKVN. IVIG was seen to be effective in reducing viral titers. The period 3-9 months post-transplantation was identified as important for development of BKVN from high BK viremia.

4.
J Strength Cond Res ; 33(5): 1429-1436, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-28195970

RESUMEN

Chan, APC, Yang, Y, Wong, FKW, Yam, MCH, Wong, DP, and Song, W-F. Reduction of physiological strain under a hot and humid environment by a hybrid cooling vest. J Strength Cond Res 33(5): 1429-1436, 2019-Cooling treatment is regarded as one of good practices to provide safe training conditions to athletic trainers in the hot environment. The present study aimed to investigate whether wearing a commercial lightweight and portable hybrid cooling vest that combines air ventilation fans with frozen gel packs was an effective means to reduce participants' body heat strain. In this within-subject repeated measures study, 10 male volunteers participated in 2 heat-stress trials (one with the cooling vest-COOL condition, and another without-CON condition, in a randomized order) inside a climatic chamber with a controlled ambient temperature 33° C and relative humidity (RH) 75% on an experimental day. Each trial included a progressively incremental running test, followed by a 40-minute postexercise recovery. Core temperature (Tc), heart rate (HR), sweat rate (SR), rating of perceived exertion (RPE), exercise duration, running distance, and power output were measured. When comparing the 2 conditions, a nonstatistically significant moderate cooling effect in rate of increase in Tc (0.03 ± 0.02° C·min for COOL vs. 0.04 ± 0.02° C·min for CON, p = 0.054, d = 0.57), HR (3 ± 1 b·min·min for COOL vs. 4 ± 1 b·min·min for CON, p = 0.229, d = 0.40), and physiological strain index (PSI) (0.20 ± 0.06 unit·min for COOL vs. 0.23 ± 0.06 unit·min for CON, p = 0.072, d = 0.50) was found in the COOL condition during exercise. A nonstatistically significant (p > 0.05) trivial cooling effect (d < 0.2) was observed between the COOL and CON conditions for measures of exercise duration, running distance, power output, SR, and RPE. It is concluded that the use of the hybrid cooling vest achieved a moderate cooling effect in lowering the rate of increase in physiological strain without impeding the performance of progressively incremental exercise in the heat.


Asunto(s)
Regulación de la Temperatura Corporal/fisiología , Crioterapia/métodos , Calor , Humedad , Ropa de Protección , Adolescente , Adulto , Atletas , Temperatura Corporal/fisiología , Diseño de Equipo , Ejercicio Físico/fisiología , Frecuencia Cardíaca/fisiología , Trastornos de Estrés por Calor , Humanos , Masculino , Esfuerzo Físico/fisiología , Carrera/fisiología , Temperatura Cutánea , Sudoración/fisiología , Adulto Joven
5.
Am J Physiol Cell Physiol ; 314(1): C118-C134, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-28978522

RESUMEN

Air pollution stimulates airway epithelial secretion through a cholinergic reflex that is unaffected in cystic fibrosis (CF), yet a strong correlation is observed between passive smoke exposure in the home and impaired lung function in CF children. Our aim was to study the effects of low smoke concentrations on cystic fibrosis transmembrane conductance regulator (CFTR) function in vitro. Cigarette smoke extract stimulated robust anion secretion that was transient, mediated by CFTR, and dependent on cAMP-dependent protein kinase activation. Secretion was initiated by reactive oxygen species (ROS) and mediated by at least two distinct pathways: autocrine activation of EP4 prostanoid receptors and stimulation of Ca2+ store-operated cAMP signaling. The response was absent in cells expressing the most common disease-causing mutant F508del-CFTR. In addition to the initial secretion, prolonged exposure of non-CF bronchial epithelial cells to low levels of smoke also caused a gradual decline in CFTR functional expression. F508del-CFTR channels that had been rescued by the CF drug combination VX-809 (lumacaftor) + VX-770 (ivacaftor) were more sensitive to this downregulation than wild-type CFTR. The results suggest that CFTR-mediated secretion during acute cigarette smoke exposure initially protects the airway epithelium while prolonged exposure reduces CFTR functional expression and reduces the efficacy of CF drugs.


Asunto(s)
Bronquios/efectos de los fármacos , AMP Cíclico/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/agonistas , Células Epiteliales/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Contaminación por Humo de Tabaco/efectos adversos , Aminofenoles/farmacología , Aminopiridinas/farmacología , Comunicación Autocrina/efectos de los fármacos , Benzodioxoles/farmacología , Bronquios/metabolismo , Bronquios/patología , Señalización del Calcio/efectos de los fármacos , Línea Celular , Fibrosis Quística/tratamiento farmacológico , Fibrosis Quística/genética , Fibrosis Quística/metabolismo , Fibrosis Quística/patología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Células Epiteliales/metabolismo , Células Epiteliales/patología , Humanos , Mutación , Quinolonas/farmacología , Subtipo EP4 de Receptores de Prostaglandina E/agonistas , Subtipo EP4 de Receptores de Prostaglandina E/metabolismo , Sistemas de Mensajero Secundario/efectos de los fármacos , Vías Secretoras/efectos de los fármacos
6.
Arthroscopy ; 34(9): 2633-2640, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29804953

RESUMEN

BACKGROUND: To determine the extent to which a strategy of routinely preparing a 5-strand hamstring autograft would increase graft size in anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 64 patients were enrolled in a prospective randomized controlled study comparing 5-strand and quadrupled semitendinosus-gracilis autografts in single-bundle ACL reconstruction (5-strand group, n = 32; 4-strand group, n = 32). In the 5-strand group, the diameter of the 4-strand construct and the subsequent 5-strand graft used were measured, whereas in the 4-strand group, the diameter of the quadrupled graft used was measured. Quadrupled graft diameter and hamstring tendon lengths were correlated with patient gender, height, weight, and body mass index (BMI). RESULTS: The mean diameter of the final graft used in the 5-strand group was 8.8 ± 0.8 mm, whereas that in the 4-strand group was 7.8 ± 0.7 mm (P < .001). The mean increase in graft size achieved with the use of the 5-strand technique was 1.4 ± 0.3 mm. In the 5-strand group, 24 of 32 (75%) patients had graft diameters exceeding 8 mm compared with 9 of 32 (28%) patients in the 4-strand group (P < .001). Quadrupled graft diameter was significantly correlated with patient height and BMI, whereas the gracilis and semitendinosus lengths were significantly correlated with patient height. CONCLUSIONS: The 5-strand hamstring autograft provides a significantly larger diameter graft compared with the quadrupled hamstring autograft in ACL reconstruction. Graft sizes exceeding 8 mm are achievable in 75% of patients with the routine application of this technique. This is significantly more than that obtained with the standard quadrupled hamstring graft. Hamstring tendon length and quadrupled hamstring graft diameter are also significantly correlated with patient height. LEVEL OF EVIDENCE: Level 1, prospective randomized controlled trial.


Asunto(s)
Reconstrucción del Ligamento Cruzado Anterior/métodos , Autoinjertos/anatomía & histología , Tendones Isquiotibiales/trasplante , Adulto , Femenino , Humanos , Masculino , Estudios Prospectivos
7.
J Therm Biol ; 70(Pt A): 21-27, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29074022

RESUMEN

A novel hybrid cooling vest (HCV) incorporated with phase change materials (PCMs) and ventilation fans has been developed for construction workers in Hong Kong to attenuate heat stress and prevent heat-related illnesses, and its effectiveness and practicality have been validated in this study. A total of 140 wear trials involving of 140 workers were conducted in Hong Kong construction sites during the summer time. Each wear trial involves a two-day wear test, of which one day workers wore the HCV (denoted as VEST) during resting, and another day they wore traditional workwear (denoted as CON). Subjects were asked to rate their perceived exertion (RPE), thermal sensations (TS) and 7 other subjective attributes. There were significant differences in the effectiveness on reducing workers' heat strain between VEST and CON in terms of alleviations of heart rate (ΔHR), ΔTS, ΔRPE as well as ΔPeSI (p < 0.001). The practicality of HCV is evidenced by a significant improvement by 0.93-1.34 on the rating scores of perceived cooling effect, sensations of comfort and skin dryness during rest and fatigue recovery in VEST at the level of 0.05, and high ratings of 4.85-5 (rating scale from 1 to 7, and the higher the better) by subjects on the preference, fitness as well as effectiveness to combat heat stress. In addition, a remarkable proportion of 91 per cent of subjects prefer to use this newly designed HCV as a cooling measure during rest. The power to alleviate perceptual heat stain (PeSA) in VEST is about twice of that by rest, which means HCV can notably improve the workers' perceptual heat strain in a limited resting duration. However, the strain alleviation power of HCV nearly remains unchanged with the prolonged rest duration. Thus, the optimal work-rest schedule needs to be investigated in a further study.


Asunto(s)
Industria de la Construcción , Calor , Ropa de Protección/normas , Adulto , Temperatura Corporal , Frecuencia Cardíaca , Hong Kong , Humanos , Masculino , Percepción , Descanso , Sudoración
8.
JAMA ; 326(18): 1873-1874, 2021 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34751712
9.
Ergonomics ; 59(4): 479-95, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26399956

RESUMEN

The purpose of this study was to develop anti-heat stress clothing for construction workers in hot and humid weather. Following DeJonge's functional clothing design process, the design situation was explored, including clothing fabric heat/moisture transporting properties and UV protection and the aspects of clothing ergonomic design (mobility, convenience, and safety). The problem structure was derived from the results of the surveys in three local construction sites, which agreed well with the task requirements and observations. Specifications were consequently described and 30 commercially available fabrics were identified and tested. Fabric testing data and design considerations were inputted in S-smart system to predict the thermal functional performance of the clothing. A new uniform prototype was developed and evaluated. The results of all measurements suggest that the new uniform which incorporated fabrics with superior heat/moisture transporting properties and loose-fitting design could reduce the workers' heat stress and improve their comfort and work performance. Practitioner Summary: The construction workers' uniform currently used in Hong Kong during summer was unsatisfactory. Following DeJonge's functional clothing design process, an anti-heat stress uniform was developed by testing 30 fabrics and predicting clothing thermal functional performance using S-smart system. The new uniform could reduce the workers' heat stress and improve their comfort and work performance.


Asunto(s)
Trastornos de Estrés por Calor/prevención & control , Calor/efectos adversos , Humedad/efectos adversos , Enfermedades Profesionales/prevención & control , Ropa de Protección , Adulto , Industria de la Construcción , Diseño de Equipo , Femenino , Trastornos de Estrés por Calor/etiología , Hong Kong , Humanos , Masculino , Persona de Mediana Edad , Salud Laboral , Encuestas y Cuestionarios , Tiempo (Meteorología) , Adulto Joven
10.
J Anaesthesiol Clin Pharmacol ; 32(1): 84-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27006548

RESUMEN

BACKGROUND AND AIMS: Diabetes affects peripheral and central neurons causing paresthesia, allodynia, hyperalgesia, and spontaneous pain. However, the effect of diabetes on response to epidural steroid injection (ESI) remains unknown. We hypothesized that diabetic patients receiving ESI will have different pain scores compared to nondiabetic patients. We tested a secondary hypothesis that pain reduction differs at different levels of hemoglobin A1c (HbA1c) for patients with diabetes. MATERIAL AND METHODS: Data from 284 consecutive patients given ESIs for radiculopathy were obtained via a manual review of electronic medical records. We initially compared diabetic and nondiabetic groups with respect to balance on baseline demographic and morphometric characteristics. Next, a linear regression model was developed to evaluate the association between existing diabetes and postinjection reduction in pain scores. And finally, we univariably characterized the association between HbA1c and pain reduction. RESULTS: After exclusion of nine patients, 275 patients were analysed, including 55 (20%) who were diabetic. Pain reduction after ESI was comparable in diabetic and nondiabetic patients (Wald test P = 0.61). The degree of pain reduction generally decreased with the level of HbA1c until reaching HbA1c levels of approximately 7.5%, after which point it stayed fairly constant. CONCLUSION: There was no difference in pain reduction after ESIs comparing diabetic with nondiabetic patients; however, for diabetic patients, pain reduction may decrease with uncontrolled diabetes determined by high HbA1c values, thus suggesting pain physicians to take an active role in guiding their patients to have their blood glucose levels better regulated to improve outcomes of their ESIs.

11.
Neurobiol Dis ; 73: 366-76, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25448764

RESUMEN

Despite advances in promoting axonal regeneration after adult central nervous system injury, elicitation of a large number of lesion-passing axons reform active synaptic connections with natural target neurons remains limited. By deleting both Pten and Socs3 in retinal ganglion cells, we report that optic nerve axons after prechiasm lesion robustly reinnervate the hypothalamus, form new synapses with neurons in the suprachiasmatic nucleus (SCN), and re-integrate with the existing circuitry. Photic or electric stimulation of the retinal axons induces neuronal response in SCN. However both the innervation pattern and evoked responses are not completely restored by the regenerating axons, suggesting that combining with other strategies is necessary to overcome the defective rewiring. Our results support that boosting the intrinsic growth capacity in injured neurons promotes axonal reinnervation and rewiring.


Asunto(s)
Axones/fisiología , Hipotálamo/fisiología , Regeneración Nerviosa/fisiología , Nervio Óptico/fisiología , Fosfohidrolasa PTEN , Células Ganglionares de la Retina/fisiología , Proteínas Supresoras de la Señalización de Citocinas , Núcleo Supraquiasmático/fisiología , Sinapsis/fisiología , Animales , Axones/patología , Hipotálamo/patología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Nervio Óptico/patología , Fosfohidrolasa PTEN/genética , Células Ganglionares de la Retina/patología , Proteína 3 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/genética , Núcleo Supraquiasmático/patología , Sinapsis/patología
12.
Proc Natl Acad Sci U S A ; 109(38): 15342-7, 2012 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-22949631

RESUMEN

Heterocysts, cells specialized for nitrogen fixation in certain filamentous cyanobacteria, appear singly in a nonrandom spacing pattern along the chain of vegetative cells. A two-stage, biased initiation and competitive resolution model has been proposed to explain the establishment of this spacing pattern. There is substantial evidence that competitive resolution of a subset of cells initiating differentiation occurs by interactions between a self-enhancing activator protein, HetR, and a diffusible pentapeptide inhibitor PatS-5 (RGSGR). Results presented here show that the absence of a unique membrane protein, PatN, in Nostoc punctiforme strain ATCC 29133 leads to a threefold increase in heterocyst frequency and a fourfold decrease in the vegetative cell interval between heterocysts. A PatN-GFP translational fusion shows a pattern of biased inheritance in daughter vegetative cells of ammonium-grown cultures. Inactivation of another heterocyst patterning gene, patA, is epistatic to inactivation of patN, and transcription of patA increases in a patN-deletion strain, implying that patN may function by modulating levels of patA. The presence of PatN is hypothesized to decrease the competency of a vegetative cell to initiate heterocyst differentiation, and the cellular concentration of PatN is dependent on cell division that results in cells transiently depleted of PatN. We suggest that biased inheritance of cell-fate determinants is a phylogenetic domain-spanning paradigm in the development of biological patterns.


Asunto(s)
Proteínas Bacterianas/fisiología , Cianobacterias/metabolismo , Proteínas de la Membrana/fisiología , Nostoc/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Diferenciación Celular , Linaje de la Célula , ADN Complementario/metabolismo , Epistasis Genética , Eliminación de Gen , Regulación Bacteriana de la Expresión Génica , Proteínas Fluorescentes Verdes/metabolismo , Proteínas de la Membrana/genética , Microscopía Fluorescente/métodos , Fijación del Nitrógeno , Análisis de Secuencia por Matrices de Oligonucleótidos , Sistemas de Lectura Abierta , Fenotipo , Filogenia , Estructura Terciaria de Proteína , Factores de Tiempo , Transcripción Genética
13.
Hong Kong Med J ; 19(3): 222-8, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23568937

RESUMEN

OBJECTIVE. To evaluate the prevalence of dysmenorrhoea, its impact, and management approaches in Hong Kong university students, and to compare between medical and non-medical students for any potential differences in coping strategies. DESIGN. Cross-sectional questionnaire survey. SETTING. The University of Hong Kong, Hong Kong. PARTICIPANTS. A total of 240 undergraduate (128 medical and 112 non-medical) students. MAIN OUTCOME MEASURES. Data on the presence and severity of dysmenorrhoea, its impact on daily life, management approaches, specific strategies, and their self-perceived effectiveness were obtained and analysed. RESULTS. In these subjects, the prevalence of dysmenorrhoea was 80% (95% confidence interval, 75-85%) with a mean (standard deviation) pain score of 5.0 (1.7). The most common impacts on daily life included reduced ability to concentrate and/or disturbance with study (75%) and changes in normal physical activity (60%). Only 6% sought medical advice, while 70% practised self-management. Pain scores and pain affecting normal physical activities were important predictive factors for self-management and for management based on pharmacological or non-pharmacological means. The commonest specific strategies used were a warm beverage (62%), paracetamol (57%), and sleeping (45%), while the most effective strategies were non-steroidal anti-inflammatory drugs (100%), traditional Chinese medicine (93%), and dietary/nutritional supplements (92%). Regarding the comparison of medical and non-medical students, the former used fewer pharmacological strategies among the various management approaches investigated. CONCLUSION. With data showing dysmenorrhoea as a very common condition having a significant impact in the Hong Kong community, primary care doctors should reassure young women with dysmenorrhoea that it is a common experience in the same age-group. Health education on the existence of effective treatment from medical practitioners could help women whose dysmenorrhoea was not controlled by self-management.


Asunto(s)
Dismenorrea/epidemiología , Educación en Salud , Autocuidado/métodos , Estudiantes/estadística & datos numéricos , Estudios Transversales , Dismenorrea/terapia , Femenino , Hong Kong/epidemiología , Humanos , Prevalencia , Índice de Severidad de la Enfermedad , Estudiantes de Medicina/estadística & datos numéricos , Encuestas y Cuestionarios , Universidades , Adulto Joven
14.
Adv Mater ; 35(8): e2210111, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36526265

RESUMEN

A dual-layer interphase that consists of an in-situ-formed lithium carboxylate organic layer and a thin BF3 -doped monolayer Ti3 C2 MXene on Li metal is reported. The honeycomb-structured organic layer increases the wetting of electrolyte, leading to a thin solid electrolyte interface (SEI). While the BF3 -doped monolayer MXene provides abundant active sites for lithium homogeneous nucleation and growth, resulting in about 50% reduced thickness of inorganic-rich components among the SEI layer. A low overpotential of less than 30 mV over 1000 h cycling in symmetric cells is received. The functional BF3  groups, along with the excellent electronic conductivity and smooth surface of the MXene, greatly reduce the lithium plating/stripping energy barrier, enabling a dendrite-free lithium-metal anode. The battery with this dual-layer coated lithium metal as the anode displays greatly improved electrochemical performance. A high capacity-retention of 175.4 mAh g-1 at 1.0 C is achieved after 350 cycles. In a pouch cell with a capacity of 475 mAh, the battery still exhibits a high discharge capacity of 165.6 mAh g-1 with a capacity retention of 90.2% after 200 cycles. In contrast to the fast capacity decay of pure Li metal, the battery using NCA as the cathode also displays excellent capacity retention in both coin and pouch cells. The dual-layer modified surface provides an effective approach in stabilizing the Li-metal anode.

15.
Cartilage ; : 19476035231194769, 2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37592438

RESUMEN

OBJECTIVE: Realignment osteotomy performed concomitantly with cartilage restoration typically requires early restricted weightbearing and can add significant morbidity, potentially leading to an increased risk of early perioperative complications. The purpose of this study was to compare the 30-day complication rates after isolated cartilage restoration (ICR) versus concomitant cartilage restoration and osteotomy (CRO) using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. DESIGN: NSQIP registries between 2006 and 2019 were queried using Current Procedural Terminology codes to identify patients undergoing ICR (autologous chondrocyte implantation, osteochondral autograft transfer, or osteochondral allograft transplantation) and CRO (with concomitant high tibial osteotomy, distal femoral osteotomy, and/or tibial tubercle osteotomy). Complications rates between treatment groups were compared using multivariate logistic regression analyses adjusted for sex, age, steroid use, and respiratory status. RESULTS: A total of 773 ICR and 97 CRO surgical procedures were identified. Mean patient ages were 35.9 years for the ICR group and 31.2 years for the CRO group. Operative time was significantly longer in the CRO group (170.8 min) compared with the ICR group (97.8 min). Multivariate analysis demonstrated no significant differences in rates of PE, VTE, and all-cause readmission between the ICR and CRO groups. No events of wound disruption, SSI and reoperation were found in the CRO group, while the ICR group was characterized by low rates of wound disruption, reoperation, and SSI (<1.1%). CONCLUSIONS: These findings further support concomitant osteotomy with cartilage restoration when appropriate and aid surgeons in the preoperative counseling of patients undergoing cartilage restoration treatment.

16.
Sci Rep ; 13(1): 2657, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36788323

RESUMEN

Musical training has been associated with various cognitive benefits, one of which is enhanced speech perception. However, most findings have been based on musicians taking part in ongoing music lessons and practice. This study thus sought to determine whether the musician advantage in pitch perception in the language domain extends to individuals who have ceased musical training and practice. To this end, adult active musicians (n = 22), former musicians (n = 27), and non-musicians (n = 47) were presented with sentences spoken in a native language, English, and a foreign language, French. The final words of the sentences were either prosodically congruous (spoken at normal pitch height), weakly incongruous (pitch was increased by 25%), or strongly incongruous (pitch was increased by 110%). Results of the pitch discrimination task revealed that although active musicians outperformed former musicians, former musicians outperformed non-musicians in the weakly incongruous condition. The findings suggest that the musician advantage in pitch perception in speech is retained to some extent even after musical training and practice is discontinued.


Asunto(s)
Música , Percepción del Habla , Adulto , Humanos , Música/psicología , Percepción de la Altura Tonal , Discriminación de la Altura Tonal , Lenguaje , Habla , Estimulación Acústica/métodos
17.
J Speech Lang Hear Res ; 66(3): 987-1017, 2023 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-36800502

RESUMEN

PURPOSE: We investigate in this study how individual variability in native language speech perception (termed Perceptual Sensitivity) influences nonnative speech perception in Singaporean Tamil-English bilinguals. Further, we assess if and how contextual and demographic factors influence Perceptual Sensitivity in the acquired languages and if the influence of Perceptual Sensitivity on nonnative speech perception is different across younger and older bilinguals. METHOD: Perceptual Sensitivity in the native languages was examined by implementing Tamil and English gating tasks in 87 Singaporean Tamil-English bilinguals from two age groups (younger: 19-33 years; older: 55-70 years). Mandarin lexical tone discrimination was implemented as a measure of nonnative speech perception. RESULTS: There was a wide range of variability in Perceptual Sensitivity scores in both languages across both age groups. Perceptual Sensitivity in the first native language (L1 Tamil) was a robust predictor of nonnative speech perception across both age groups, especially for the older bilinguals. However, general intelligence emerged as a stronger predictor than Tamil Perceptual Sensitivity in younger bilinguals. The influence of Tamil Perceptual Sensitivity on lexical tone perception was not tone-specific, supporting a general enhancement of lexical tone perception with better Tamil Perceptual Sensitivity. There was an influence of demographic factors on English Perceptual Sensitivity in older bilinguals, but not for Tamil and not in younger bilinguals. CONCLUSIONS: Our findings corroborate with previous studies in showing that native language Perceptual Sensitivity is positively associated with and predicts nonnative speech perception in younger and older adulthood regardless of language similarity but to varying degrees. Specifically, the influence of Perceptual Sensitivity on nonnative speech perception is stronger in older adulthood, suggesting a possible shift in reliance on crystallized language knowledge with age. Proficiency and use, among other demographic and language variables, do not appear to influence L1 Perceptual Sensitivity in a lesser used language (Tamil) as significantly as previously assumed.


Asunto(s)
Multilingüismo , Percepción del Habla , Adulto , Anciano , Humanos , Adulto Joven , Pueblo Asiatico , India , Lenguaje , Fonética , Persona de Mediana Edad
18.
J Speech Lang Hear Res ; 66(10): 4137-4149, 2023 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-37656601

RESUMEN

PURPOSE: This study examines the effects of an auditory training program on the auditory and cognitive abilities of older adults. Auditory rehabilitation programs are generally designed for hearing aid users, and studies have demonstrated benefits for them. In this study, we seek to understand whether such a training program can also benefit older adults who do not wear hearing aids. We also examined if cognitive benefits can indeed be observed as a result of the training. METHOD: Sixty-four older adults were recruited and assigned into three groups: the experimental group (n = 20), the active control group (n = 21), and the no-training control group (n = 23). The experimental group underwent an auditory training program (Listening and Communication Enhancement [LACE]) during the training phase. Meanwhile, the active control group listened to short audio clips and the no-training control group did not participate in any program. An auditory test (Quick Speech-in-Noise [QuickSIN]) and a battery of cognitive tests were conducted before and after the training to examine the participants' performance on auditory ability, short-term memory, and attention. RESULTS: The results showed improvements in auditory and cognitive abilities during the training period. When assessing the training effects by comparing the pre- and the posttraining performances, a significant improvement on the QuickSIN task was found in the training group but not in the other two groups. However, other cognitive tests did not show any significant improvement. That is, the LACE training did not benefit short-term memory and attention. The improved performance on short-term memory during the training was not maintained in the posttraining session. CONCLUSION: Overall, the study has extended the auditory benefit from the LACE training to the typical aging population in terms of improved communication ability, but the effect of training on auditory abilities did not transfer to gains in cognitive abilities.


Asunto(s)
Percepción del Habla , Humanos , Anciano , Trastornos de la Audición , Ruido , Cognición , Pruebas Auditivas
19.
J Neurosci ; 31(24): 8780-5, 2011 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-21677162

RESUMEN

According to the dual stream model of auditory language processing, the dorsal stream is responsible for mapping sound to articulation and the ventral stream plays the role of mapping sound to meaning. Most researchers agree that the arcuate fasciculus (AF) is the neuroanatomical correlate of the dorsal steam; however, less is known about what constitutes the ventral one. Nevertheless, two hypotheses exist: one suggests that the segment of the AF that terminates in middle temporal gyrus corresponds to the ventral stream, and the other suggests that it is the extreme capsule that underlies this sound-to-meaning pathway. The goal of this study was to evaluate these two competing hypotheses. We trained participants with a sound-to-word learning paradigm in which they learned to use a foreign phonetic contrast for signaling word meaning. Using diffusion tensor imaging, a brain-imaging tool to investigate white matter connectivity in humans, we found that fractional anisotropy in the left parietal-temporal region positively correlated with the performance in sound-to-word learning. In addition, fiber tracking revealed a ventral pathway, composed of the extreme capsule and the inferior longitudinal fasciculus, that mediated auditory comprehension. Our findings provide converging evidence supporting the importance of the ventral steam, an extreme capsule system, in the frontal-temporal language network. Implications for current models of speech processing are also discussed.


Asunto(s)
Aprendizaje por Asociación/fisiología , Mapeo Encefálico , Fibras Nerviosas Mielínicas/fisiología , Vías Nerviosas/fisiología , Sonido , Vocabulario , Adulto , Anisotropía , Imagen de Difusión Tensora/métodos , Femenino , Lateralidad Funcional , Humanos , Masculino , Vías Nerviosas/anatomía & histología , Valor Predictivo de las Pruebas , Probabilidad , Adulto Joven
20.
Front Psychol ; 13: 940363, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36248535

RESUMEN

This study sought to understand the effects of tone language repertoire and musical experience on nonnative lexical tone perception and production. Thirty-one participants completed a tone discrimination task, an imitation task, and a musical abilities task. Results showed that a larger tone language repertoire and musical experience both enhanced tone discrimination performance. However, the effects were not additive, as musical experience was associated with tone discrimination performance for single-tone language speakers, but such association was not seen for dual-tone language speakers. Furthermore, among single-tone language speakers, but not among dual-tone language speakers, musical experience and musical aptitude positively correlated with tone discrimination accuracy. It is thus concluded that individuals with varying extents of tone language experience may adopt different strategies when performing tone discrimination tasks; single-tone language speakers may draw on their musical expertise while dual-tone language speakers may rely on their extensive tone language experience instead.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA