Analysis of clinical characteristics of thyroid phenotype in Pendred syndrome based on multiple databases.

OBJECTIVE: This study aimed to provide statistical data support for the development of thyroid phenotype-related follow-up and reference for follow-up duration and project selection by analyzing the clinical characteristics of thyroid phenotype in Pendred syndrome (PDS) based on multiple databases. MATERIALS AND METHODS: PDS-related pathogenic or possibly/pathogenic mutations were searched by Deafness Variation Database (DVD), ClinVar, and PubMed databases, the mutation sites were counted and the characteristics and thyroid phenotypes were analyzed. RESULTS: The median age of hearing phenotype onset in PDS cases reported in multiple databases was 1.0 (1.0, 2.0) years, the median age of thyroid phenotype onset was 14.5 (5.8, 21.0) years, and the median age that thyroid phenotype was more delayed than hearing phenotype was 10.0 (4.0, 17.0) years. There were significant differences in the distribution of onset time between the two phenotypes (Z=-4.560, p<0.01). In these patients, the positive rates of goiter, thyroid nodules, abnormal thyroid function, and perchlorate discharge test (PDT) were 78%, 78%, 69%, and 78%, respectively. Moreover, the number of thyroid phenotype-positive items in the genotype group with frameshift mutation was not significantly higher than that in the group without frameshift mutation (Z=-1.452, p=0.147). CONCLUSIONS: The early missed diagnosis of PDS may be due to the late onset of thyroid phenotype and the non-100% positive rate of examination items. Therefore, multi-item follow-up of the thyroid gland into adulthood will benefit patients. At present, the relationship between genotype and phenotype is still unclear, and prognosis cannot be determined according to genotype.

Fabrication of silicon molds with multi-level, non-planar, micro- and nano-scale features.

A method for single-step fabrication of arbitrary, complex, three-dimensional (3D) silicon structures from the nano- to millimeter-scale at multiple levels on non-planar, curved, or domed surfaces is reported. The fabrication is based on focused or masked ion beam irradiation of p-type silicon followed by electrochemical anodization. The process allows fabrication of a wide range of surface features at multiple heights and with arbitrary orientations by varying the irradiated feature width, ion type, energy fluence, and subsequent anodization conditions. The technology has achieved depth resolution of 10 nm as step heights and is capable of creating lateral features down to 7 nm at high aspect ratios of up to 40, with surface roughness down to 1 nm scaled up to full wafer areas. The single-step ability has seamlessly interfaced a network of complex, integrated micro- to nano-structures in 3D orientations with no alignment required. The final template has been converted to a master copy for nano-imprinting lithography of 3D fluidic structures and optical components.

Reprogramming hMSCs morphology with silicon/porous silicon geometric micro-patterns.

Geometric micro-patterned surfaces of silicon combined with porous silicon (Si/PSi) have been manufactured to study the behaviour of human Mesenchymal Stem Cells (hMSCs). These micro-patterns consist of regular silicon hexagons surrounded by spaced columns of silicon equilateral triangles separated by PSi. The results show that, at an early culture stage, the hMSCs resemble quiescent cells on the central hexagons with centered nuclei and actin/ß-catenin and a microtubules network denoting cell adhesion. After 2 days, hMSCs adapted their morphology and cytoskeleton proteins from cell-cell dominant interactions at the center of the hexagonal surface. This was followed by an intermediate zone with some external actin fibres/ß-catenin interactions and an outer zone where the dominant interactions are cell-silicon. Cells move into silicon columns to divide, migrate and communicate. Furthermore, results show that Runx2 and vitamin D receptors, both specific transcription factors for skeleton-derived cells, are expressed in cells grown on micropatterned silicon under all observed circumstances. On the other hand, non-phenotypic alterations are under cell growth and migration on Si/PSi substrates. The former consideration strongly supports the use of micro-patterned silicon surfaces to address pending questions about the mechanisms of human bone biogenesis/pathogenesis and the study of bone scaffolds.

Influence of the narrow {111} planes on axial and planar ion channeling.

We report channeling patterns where clearly resolved effects of the narrow {111} planes are observed in axial and planar alignments for 2 MeV protons passing through a 55 nm [001] silicon membrane. At certain axes, such as <213> and <314>, the offset in atomic rows forming the narrow {111} planes results in shielding from the large potential at the wide {111} planes, producing a region of shallow, asymmetric potential from which axial channeling patterns have no plane of symmetry. At small tilts from such axes, different behavior is observed from the wide and narrow {111} planes. At planar alignment, distinctive channeling effects due to the narrow planes are observed. As a consequence of the shallow potential well at the narrow planes, incident protons suffer dechanneled trajectories which are excluded from channeling within the wide planes, resulting in an anomalously large scattered beam at {111} alignment.