Citation: Sampson DM, Gong P, An D, et al. Axial length variation impacts on superficial retinal vessel density and foveal avascular zone area measurements using optical coherence tomography angiography. Invest Ophthalmol Vis Sci. 2017;58:3065-3072. DOI:10.1167/iovs.17-21551 PURPOSE. To evaluate the impact of image magnification correction on superficial retinal vessel density (SRVD) and foveal avascular zone area (FAZA) measurements using optical coherence tomography angiography (OCTA). METHODS.Participants with healthy retinas were recruited for ocular biometry, refraction, and RTVue XR Avanti OCTA imaging with the 3 3 3-mm protocol. The foveal and parafoveal SRVD and FAZA were quantified with custom software before and after correction for magnification error using the Littman and the modified Bennett formulae. Relative changes between corrected and uncorrected SRVD and FAZA were calculated.RESULTS. Forty subjects were enrolled and the median (range) age of the participants was 30 (18-74) years. The mean (range) spherical equivalent refractive error was À1.65 (À8.00 to þ4.88) diopters and mean (range) axial length was 24.42 mm (21.27-28.85). Images from 13 eyes were excluded due to poor image quality leaving 67 for analysis. Relative changes in foveal and parafoveal SRVD and FAZA after correction ranged from À20% to þ10%, À3% to þ2%, and À20% to þ51%, respectively. Image size correction in measurements of foveal SRVD and FAZA was greater than 5% in 51% and 74% of eyes, respectively. In contrast, 100% of eyes had less than 5% correction in measurements of parafoveal SRVD.CONCLUSIONS. Ocular biometry should be performed with OCTA to correct image magnification error induced by axial length variation. We advise caution when interpreting interocular and interindividual comparisons of SRVD and FAZA derived from OCTA without image size correction.

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Graphene oxide (GO) is a type of twodimensional nanomaterial with a single-atom thickness. GO sheets contain pristine regions, oxidized regions, and a small fraction of holes. By stacking GO sheets together, a GO membrane can be fabricated with sufficient mechanical strength. The interlayer nanocapillary network formed from connected interlayer spaces, together with the gaps between the edges of noninterlocked neighboring GO sheets and cracks or holes of the GO sheet, provides passage for molecules or ions to permeate through the GO membrane in an aqueous solution. The characteristics of molecules or ions (e.g., their size, charge, and the interaction with the GO membrane) affect the separation performance of the GO membrane. The contribution of gaps between neighboring GO sheets for separation can be adjusted by changing the GO sheet size and the GO membrane thickness. The interlayer space of the GO membrane can be adjusted by changing the water pH and modifying or reducing the GO sheets to obtain the desired separation performance. The production of the GO membrane is easily scalable and relatively inexpensive, indicating that the GO membrane has promising potential for applications such as water treatment, desalination, anticorrosion, chemical resistance, and controlled release coatings.

MicroRNAs (miRNAs), which are small noncoding RNA molecules, play important roles in the post-transcriptional regulation process. The microRNA-21 gene (miR-21) has been reported to be highly expressed in various solid tumors, including breast cancer. Bone morphogenetic protein-6 (BMP-6) has been identified as an inhibitor of breast cancer epithelial-mesenchymal transition (EMT) through rescuing E-cadherin expression. We initiated experiments to identify the relationships between miR-21 and BMP-6 in breast cancer progression. Real-time PCR analysis showed that miR-21 expression was very high in MDA-MB-231 cells that expressed little BMP-6. A reverse correlation between BMP-6 and miR-21 was also determined in breast cancer tissue samples. Moreover, BMP-6 inhibited miR-21 transcription in MDA-MB-231 cells. In order to investigate how BMP-6 inhibited the miR-21 promoter (miPPR-21), we constructed a series of miPPR-21 reporters. Luciferase assay results indicated that BMP-6 inhibited miPPR-21 activity through the E2-box and AP-1-binding sites. We also demonstrated that both δEF1 and TPA induced miR-21 expression. Using site-directed mutation and CHIP assay, we found that δEF1 induced miPPR-21 activity by binding to the E2-box on miPPR-21. Moreover, TPA triggered miPPR-21 activity through the AP-1 binding sites. BMP-6 treatment significantly reduced the binding of these factors to miPPR-21 by decreasing the expression of δEF1 and c-Fos/c-Jun. We also demonstrated that BMP-6-induced downregulation of miR-21 modified the activity of PDCD4 3′UTR and inhibited MDA-MB-231 cell invasion. δEF1 overexpression and TPA induction blocked this inhibitory effect of BMP-6. In conclusion, BMP-6-induced inhibition of miR-21 suggests that BMP-6 may function as an anti-metastasis factor by a mechanism involving transcriptional repression of miR-21 in breast cancer.

In this work, we prepared Al2O3 ceramic green parts with complex geometry and architecture using an additive manufacturing process based on stereolithography. The rheological and thermal behavior of Al2O3 slurry was firstly examined and used to establish the conditions for molding and debinding. As opposed to previous researches that only focused on manufacture techniques, the sintering behavior and densification process were systematically investigated. In addition, special attentions were paid to the evolution of microstructure between green bodies and sintered parts. The results showed that debound parts were equipped with uniform particle packing and narrow pore size distribution. The dimensions of the Al2O3 parts changed anisotropically with the different processing steps. The densification process was greatly accelerated by the decrease in pore size and annihilating of interconnected pores in which significant grain growth was observed above 1450°C. The sintered part also had a homogeneous microstructure and no interface between adjacent layers. High densification (relative density of 99.1%) and much desirable Vickers hardness (17.9 GPa) of Al2O3 parts were achieved at the sintering temperature of 1650°C.

A recently developed emulsion-templated assembly method promises the scalable, low-cost, and reproducible fabrication of hierarchical nanocrystal (NC) superstructures. These superstructures derive properties from the unique combination of choices of NC building blocks and superstructure morphology and therefore realize the concept of “artificial solids”. To control the final properties of these superstructures, it is essential to control the assembly conditions that yield distinct architectural morphologies. Here, we explore the phase-space of experimental parameters describing the emulsion-templated assembly including temperature, interfacial tension, and NC polydispersity and demonstrate which conditions lead to the growth of the most crystalline NC superstructures or supercrystals. By using a combination of electron microscopy and small-angle X-ray scattering, we show that slower assembly kinetics, softer interfaces, and lower NC polydispersity contribute to the formation of supercrystals with grain sizes up to 600 nm, while reversing these trends yields glassy solids. These results provide a clear path to the realization of higher-quality supercrystals, necessary to many applications.

We design a reflective silver dendritic metasurface that can perform differential operation at visible wavelengths. The metasurface consists of an upper layer of silver dendritic structures, a silica spacer, and a lower layer of silver film. Simulation results show that the metasurface can realize differential operation in red, yellow, and green bands. Such a functionality is readily extended to infrared and communication wavelengths. The metasurface samples that respond to green and red bands are prepared by using the electrochemical deposition method, and their differential operation properties are proved through tests. Silver dendritic metasurfaces that can conduct the mathematical operation in visible light pave the way for realizing miniaturized, integratable all-optical information processing systems. Their differentiation functionality, which is used for real-time ultra-fast edge detection, image contrast enhancement, hidden object detection, and other practical applications, has a great development potential.