RESUMO
The cuprate high-temperature superconductors exhibit many unexplained electronic phases, but the superconductivity at high doping is often believed to be governed by conventional mean-field Bardeen-Cooper-Schrieffer theory1. However, it was shown that the superfluid density vanishes when the transition temperature goes to zero2,3, in contradiction to expectations from Bardeen-Cooper-Schrieffer theory. Our scanning tunnelling spectroscopy measurements in the overdoped regime of the (Pb,Bi)2Sr2CuO6+δ high-temperature superconductor show that this is due to the emergence of nanoscale superconducting puddles in a metallic matrix4,5. Our measurements further reveal that this puddling is driven by gap filling instead of gap closing. The important implication is that it is not a diminishing pairing interaction that causes the breakdown of superconductivity. Unexpectedly, the measured gap-to-filling correlation also reveals that pair breaking by disorder does not play a dominant role and that the mechanism of superconductivity in overdoped cuprate superconductors is qualitatively different from conventional mean-field theory.
RESUMO
BACKGROUND: We designed a novel ankle foot orthosis (AFO), namely, ideal training AFO (IT-AFO), with motion feedback on the hemiparetic lower limb to improve ambulation in individuals with stroke-related hemiplegia. We, therefore sought to compare the kinematic parameters of gait between IT-AFO with and without dynamic control and conventional anterior-type AFO or no AFO. METHODS: Gait parameters were measured using the RehaWatch® system in seven individuals with hemiplegia (mean 51.14 years). The parameters were compared across four conditions: no AFO, conventional anterior AFO, IT-AFO without dynamic control, and IT-AFO with dynamic control, with three trials of a 10-m walk test for each. RESULTS: The dorsiflexion angle increased during the swing phase when the IT-AFO was worn, and it was larger with dynamic control. These data can confirm drop foot improvement; however, the difference between the parameters with- and without-AFO control conditions was not significant in the swing phase. The IT-AFO with or without dynamic control enhanced the loading response to a greater extent between the hemiparetic and unaffected lower limbs than conventional AFO or no AFO. The duration of the stance phase on the hemiparetic lower limb was also longer when using IT-AFO with and without dynamic control than that when using conventional AFO, which improved asymmetry. User comfort and satisfaction was greater with IT-AFO than with the other conditions. CONCLUSIONS: The IT-AFO with dynamic control improved gait pattern and weight shifting to the hemiparetic lower limb, reducing gait asymmetry. The difference with and without dynamic control of IT-AFO is not statistically significant, and it is limited by sample size. However, this study shows the potential of IT-AFO in applying positive motion feedback with gait training. TRIAL REGISTRATION: Taipei Medical University-Joint Institutional Review Board. N201510010 . Registered 12 February 2015. http://ohr.tmu.edu.tw/main.php .
Assuntos
Retroalimentação Sensorial , Órtoses do Pé , Transtornos Neurológicos da Marcha/reabilitação , Reabilitação do Acidente Vascular Cerebral/instrumentação , Adulto , Idoso , Idoso de 80 Anos ou mais , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Retroalimentação Sensorial/fisiologia , Feminino , Transtornos Neurológicos da Marcha/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Desenho de Prótese/métodos , Acidente Vascular Cerebral/complicaçõesRESUMO
Hydroxypropyl methylcellulose (HPMC) and curdlan (CL) were used to prepare uniform films. The influence of the composition ratios and drying temperature on the microstructures, compatibility and physical performance of HPMC/CL films were studied. The crystalline peaks corresponding to CL component of HPMC/CL films increased with the increasing CL content. Increasing CL content resulted in increased hydrogen bonds in HPMC/CL film, reduced transmittance at 500 nm, oxygen permeability and water solubility of the HPMC/CL films. Higher drying temperature led to increased phase separation and decreased physical properties of pure HPMC film, and led to increased compatibility, cross-section smoothness, oxygen barrier property and mechanical properties of pure CL and blending films.
Assuntos
Dessecação , Oxigênio , Derivados da Hipromelose/química , Temperatura , beta-GlucanasRESUMO
Spasticity measured by manual tests, such as modified Ashworth scale (MAS), may not sufficiently reflect mobility function in stroke survivors. This study aims to identify additional ambulatory information provided by the pendulum test. Clinical assessments including Brünnstrom recovery stage, manual muscle test, MAS, Tinetti test (TT), Timed up and go test, 10-m walk test (10-MWT), and Barthel index were applied to 40 ambulant chronic stroke patients. The pendular parameters, first swing excursion (FSE) and relaxation index (RI), were extracted by an electrogoniometer. The correlations among these variables were analyzed by the Spearman and Pearson partial correlation tests. After controlling the factor of motor recovery (Brünnstrom recovery stage), the MAS of paretic knee extensor was negatively correlated with the gait score of TT (r = - 0.355, p = 0.027), while the FSE revealed positive correlations to the balance score of TT (r = 0.378, p = 0.018). RI were associated with the comfortable speed of 10-MWT (r = 0.367, p = 0.022). These results suggest a decrease of knee extensor spasticity links to a better gait and balance in chronic stroke patients. The pendular parameters can provide additional ambulatory information, as complementary to the MAS. The pendulum test can be a potential tool for patient selection and outcome assessment after spasticity treatments in chronic stroke population.