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Abstract Background The arachnoid granulations (AGs) are herniations of the arachnoid membrane into the dural venous sinuses on the surface of the brain. Previous morphological studies of AGs have been limited in scope and only one has mentioned surface area measurements. The purpose of this study was to investigate the topographic distribution of AGs on the superior surface of the cerebral cortex. Methods En face images were taken of the superior surface of 35 formalin-fixed human brains. AGs were manually identified using Adobe Photoshop, with a pixel location containing an AG defined as 'positive'. A set of 25 standard fiducial points was marked on each hemisphere for a total of 50 points on each image. The points were connected on each hemisphere to create a segmented image. A standard template was created for each hemisphere by calculating the average position of the 25 fiducial points from all brains. Each segmented image was mapped to the standard template using a linear transformation. A topographic distribution map was produced by calculating the proportion of AG positive images at each pixel in the standard template. The AG surface area was calculated for each hemisphere and for the total brain superior surface. To adjust for different brain sizes, the proportional involvement of AGs was calculated by dividing the AG area by the total area. Results The total brain average surface area of AGs was 78.53 ± 13.13 mm2 (n = 35) and average AG proportional involvement was 57.71 × 10-4 ± 7.65 × 10-4. Regression analysis confirmed the reproducibility of AG identification between independent researchers with r2 = 0.97. The surface AGs were localized in the parasagittal planes that coincide with the region of the lateral lacunae. Conclusion The data obtained on the spatial distribution and en face surface area of AGs will be used in an in vitro model of CSF outflow. With an increase in the number of samples, this analysis technique can be used to study the relationship between AG surface area and variables such as age, race and gender.

Purpose: Loss of corneal transparency is one of the major causes of visual loss, generating a considerable health and economic burden globally. Corneal transplantation is the leading treatment procedure, where the diseased cornea is replaced by donated corneal tissue. Despite the rise of cornea donations in the past decade, there is still a huge gap between cornea supply and demand worldwide. 3D bioprinting is an emerging technology that can be used to fabricate tissue equivalents that resemble the native tissue, which holds great potential for corneal tissue engineering application. This study evaluates the manufacturability of 3D bioprinted acellular corneal grafts using low-cost equipment and software, not necessarily designed for bioprinting applications. This approach allows access to 3D printed structures where commercial 3D bioprinters are cost prohibitive and not readily accessible to researchers and clinicians., Methods: Two extrusion-based methods were used to 3D print acellular corneal stromal scaffolds with collagen, alginate, and alginate-gelatin composite bioinks from a digital corneal model. Compression testing was used to determine moduli., Results: The printed model was visually transparent with tunable mechanical properties. The model had central radius of curvature of 7.4 mm, diameter of 13.2 mm, and central thickness of 0.4 mm. The compressive secant modulus of the material was 23.7 ± 1.7 kPa at 20% strain. 3D printing into a concave mold had reliability advantages over printing into a convex mold., Conclusions: The printed corneal models exhibited visible transparency and a dome shape, demonstrating the potential of this process for the preparation of acellular partial thickness corneal replacements. The modified printing process presented a low-cost option for corneal bioprinting.

Background: 3D-printed patient-specific anatomical models are becoming an increasingly popular tool for planning reconstructive surgeries to treat oral cancer. Currently there is a lack of information regarding model accuracy, and how the resolution of the computed tomography (CT) scan affects the accuracy of the final model., Purpose: The primary objective of this study was to determine the CT z-axis resolution necessary in creating a patient specific mandibular model with clinically acceptable accuracy for global bony reconstruction. This study also sought to evaluate the effect of the digital sculpting and 3D printing process on model accuracy., Study Design: This was a cross-sectional study using cadaveric heads obtained from the Ohio State University Body Donation Program., Independent Variables: The first independent variable is CT scan slice thickness of either 0.675 , 1.25, 3.00, or 5.00 mm. The second independent variable is the three produced models for analysis (unsculpted, digitally sculpted, 3D printed)., Main Outcome Variable: The degree of accuracy of a model as defined by the root mean square (RMS) value, a measure of a model's discrepancy from its respective cadaveric anatomy., Analyses: All models were digitally compared to their cadaveric bony anatomy using a metrology surface scan of the dissected mandible. The RMS value of each comparison evaluates the level of discrepancy. One-way ANOVA tests (P < .05) were used to determine statistically significant differences between CT scan resolutions. Two-way ANOVA tests (P < .05) were used to determine statistically significant differences between groups., Results: CT scans acquired for 8 formalin-fixed cadaver heads were processed and analyzed. The RMS for digitally sculpted models decreased as slice thickness decreased, confirming that higher resolution CT scans resulted in statistically more accurate model production when compared to the cadaveric gold standard. Furthermore, digitally sculpted models were significantly more accurate than unsculpted models (P < .05) at each slice thickness., Conclusions: Our study demonstrated that CT scans with slice thicknesses of 3.00 mm or smaller created statistically significantly more accurate models than models created from slice thicknesses of 5.00 mm. The digital sculpting process statistically significantly increased the accuracy of models and no loss of accuracy through the 3D printing process was observed., (Copyright © 2023 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

A chemical synthesis method is presented for the fabrication of high-definition segmented metal-oxide-metal (MOM) nanowires in two different ferroelectric oxide systems: Au-BaTiO(3)-Au and Au-PbTiO(3)-Au. This method entails electrodeposition of segmented nanowires of Au-TiO(2)-Au inside anodic aluminum oxide (AAO) templates, followed by topotactic hydrothermal conversion of the TiO(2) segments into BaTiO(3) or PbTiO(3) segments. Two-terminal devices from individual MOM nanowires are fabricated, and their ferroelectric properties are measured directly, without the aid of scanning probe microscopy (SPM) methods. The MOM nanowire architecture provides high-quality end-on electrical contacts to the oxide segments, and allows direct measurement of properties of nanoscale volume, strain-free oxide segments. Unusually high ferroelectric responses, for chemically synthesized oxides, in these MOM nanowires are reported, and are attributed to the lack of residual strain in the oxides. The ability to measure directly the active properties of nanoscale volume, strain-free oxides afforded by the MOM nanowire architecture has important implications for fundamental studies of not only ferroelectric nanostructures but also nanostructures in the emerging field of multiferroics.