Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Sci Rep ; 13(1): 9737, 2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-37322040

RESUMEN

Dominantly inherited GAA repeat expansions in FGF14 are a common cause of spinocerebellar ataxia (GAA-FGF14 ataxia; spinocerebellar ataxia 27B). Molecular confirmation of FGF14 GAA repeat expansions has thus far mostly relied on long-read sequencing, a technology that is not yet widely available in clinical laboratories. We developed and validated a strategy to detect FGF14 GAA repeat expansions using long-range PCR, bidirectional repeat-primed PCRs, and Sanger sequencing. We compared this strategy to targeted nanopore sequencing in a cohort of 22 French Canadian patients and next validated it in a cohort of 53 French index patients with unsolved ataxia. Method comparison showed that capillary electrophoresis of long-range PCR amplification products significantly underestimated expansion sizes compared to nanopore sequencing (slope, 0.87 [95% CI, 0.81 to 0.93]; intercept, 14.58 [95% CI, - 2.48 to 31.12]) and gel electrophoresis (slope, 0.84 [95% CI, 0.78 to 0.97]; intercept, 21.34 [95% CI, - 27.66 to 40.22]). The latter techniques yielded similar size estimates. Following calibration with internal controls, expansion size estimates were similar between capillary electrophoresis and nanopore sequencing (slope: 0.98 [95% CI, 0.92 to 1.04]; intercept: 10.62 [95% CI, - 7.49 to 27.71]), and gel electrophoresis (slope: 0.94 [95% CI, 0.88 to 1.09]; intercept: 18.81 [95% CI, - 41.93 to 39.15]). Diagnosis was accurately confirmed for all 22 French Canadian patients using this strategy. We also identified 9 French patients (9/53; 17%) and 2 of their relatives who carried an FGF14 (GAA)≥250 expansion. This novel strategy reliably detected and sized FGF14 GAA expansions, and compared favorably to long-read sequencing.


Asunto(s)
Ataxia de Friedreich , Ataxias Espinocerebelosas , Humanos , Canadá , Ataxia de Friedreich/genética , Ataxias Espinocerebelosas/genética , Expansión de Repetición de Trinucleótido
2.
Polymers (Basel) ; 14(21)2022 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-36365699

RESUMEN

Poly (methacrylic acid) (PMAA) solutions are known to exhibit a lower critical solution temperature (LCST). A temperature-composition phase diagram of PMAA has been constructed by standard cloud point determination through transmittance measurements, and also by studying the steady states reached under phase separation. This allows us to reconstruct the binodal curve describing the phase behavior of PMAA for both low and high concentration regimes, and to determine accurately the LCST temperature. In a second step, the structures formed following a temperature jump above the cloud point and their evolution in time have been investigated at the nanoscale using small angle neutron scattering (SANS). This approach shows that the formation of phase-separated nanostructures is a slow process, requiring more than 12 h. The formed structures are then shown to depend on the amplitude of the temperature jump above the cloud point. An original mechanism of phase separation is identified in the semi-dilute regime. The growth of micrometric-size droplets with an inner structure displaying the rheological properties of a gel leads to the formation of a percolating network which hinders the influence of gravity. Such a result can explain the slow kinetics of the PMAA LCST transition.

3.
Appl Opt ; 52(7): 1505-11, 2013 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-23458805

RESUMEN

A fast graphics processing unit implementation of the finite-difference time-domain model was used to determine the computational effort required to accurately characterize the mean scattering functions of randomly orientated aspherical particles. The influence of the number of randomized rotational positions on the accuracy of the mean scattering phase function curve was appraised. In general, multiplying the number of orientations by 100 gives increased accuracy of factor 10. Dependent on particle shape, certain regions of the phase function were insensitive to particle orientation. In addition, an error in a key previous publication on scattering by aspherical particles was identified.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...