Foveal pit morphological changes in asymptomatic carriers of the G11778A mutation with Leber’s hereditary optic neuropathy

AIM:To investigate the foveal pit morphology changes in unaffected carriers and affected Leber’s hereditary optic neuropathy(LHON)patients with the G11778 A mutation from one family.METHODS:This study was a prospective cross-sectional study.Both eyes from 16 family members(age from 9 to 47 y)with the G11778 A mutation were analyzed and compared with 1 eye from 20 normal control subjects.Eleven family members with the G11778 A mutation but without optic neuropathy were classified as unaffected carriers(n=22 eyes).Five family members(n=10 eyes)expressed the LHON phenotype and were classified as affected patients.Retinal images of all the subjects were taken by optical coherence tomography(OCT),and an automatic algorithm was used to segment the retina to eight layers.Horizontal and vertical OCT images centered on the fovea were used to measure intra-retinal layer thicknesses and foveal morphometry.RESULTS:Thicker foveal thickness,thinner foveal pit depth,and flatter foveal slopes were observed in unaffected carriers and affected LHON patients(all P<0.001).Further,the slopes of all four sectors in the LHON were flatter than those in the unaffected carriers(all P<0.001).Compared with the control group,affected LHON patients had a thinner retinal nerve fiber layer(RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),and total retina(all P<0.01).The retinal nerve fiber layer(RNFL)of affected patients was 38.0%thinner than that of controls while the GCL+IPL was 40.1%thinner.CONCLUSION:The foveal pit morphology shows changes in both unaffected carriers and affects patients.RNFL and GCL+IPL are thinner in affected LHON patients but not in unaffected carriers.

Influence of Coupled Chemo-Mechanical Process on Corrosion Characteristics in Reinforcing Bars

We studied the corrosion characteristics of reinforcing bars in concrete under different corrosion conditions. The area-box （AB） value was used to classify the shape of pitting corrosion morphology in meso-scale, and fractographs of reinforcing bars with different corrosion morphology were discussed in micro- and macro-scales. The results show that the existence of the tensile stress affects the corrosion characteristics of reinforcing bars. The pitting morphology and fractograph of reinforcing bars exhibit a statistical fractal feature. The linear regression model fits the relationship between fractal dimensions of corrosion morphology and fractal dimension of fractograph fairly well. Using fractal dimension as the characterization parameter can not only reflect the characteristics of pitting corrosion morphology in reinforcing bars, but also reveal the fracture feature of corroded reinforcing bars.

Discovery and implications of catenary-bead subaqueous dunes

Measurements of topography at the segment of bifurcation between the South Channel and North Channel in the Yangtze Estuary were conducted, and a new type of subaqueous dune was discovered. This structure, newly defined as a catenary-bead dune, consists of a catenary dune and its associated elliptical pit bedform. Based on this finding, the nomenclature of "morphology of dune associated with accompanying bedform" is first proposed. The measured data indicate a mean height and wavelength of 1.29 m and 31.89 m, respectively; wavelength/height ratio(L/H) of 14 to 56; and elliptical pits of mean and maximum depth 0.98 m and 1.98 m, respectively. Flow information was obtained using an Acoustic Doppler Current Profile(ADCP), and the bed material components were gathered with a bottom sampler. The results show mean flood and ebb velocities of 0.27 and 0.78 m s?1, respectively, with shorter duration of flood tide than ebb tide. The silt, very fine sand, and fine sand fractions were within the ranges 21.6–23.4%, 28.2–32.2%, and 39.7–41.6%, respectively, revealing complex bed material composition. Water depth at the study site varies from 13 to 17 m. This finding will enrich the study of dunes and provide important data for geomorphological research. Moreover, the results are significant for engineering applications to estuaries.