Branch-cut algorithm with second-order residues in phase unwrapping.

This Letter presents a novel, to the best of our knowledge, branch-cut algorithm for unwrapping phase maps acquired through fringe projection systems. The algorithm exposes second-order residues with vortex phase structures, computed from the original wrapped phase distribution using a second-order derivative that considers the wrap cycle. Remarkably, it reveals a consistent vorticity direction associated with these vortex structures, significantly facilitating branch-cut connections between residues, regardless of whether they carry the same or opposite charges. This innovative approach challenges a longstanding misconception in conventional branch-cut methods, which traditionally connected matched residues only when they had opposite charges. As a result, the algorithm provides a highly accurate methodology for explaining how phase behavior relates to surface characteristics. Its effectiveness is demonstrated through both computer simulations and practical experiments.

Wrap-type phase unwrapping utilizing arctangent operation as a differential amplifier through shifted phase maps.

This paper introduces a novel phase unwrapping algorithm based on the investigation of the arctangent function. Acting as a differential amplifier associated with nonlinear response, the arctangent operation facilitates distinguishing various wrap types. Phase jumps from two shifted-wrapped maps aligned on the same grids are combined as a pair to function as differential mode inputs. This discerns wraps from continuous and discontinuous surfaces through distinct outputs (threshold phase values). Simulations and experiments validate the feasibility of the proposed wrap-type identification. A complete mathematical form is derived to explain the effects of shifted wraps due to various causes. This paper significantly contributes to the foundational understanding of the 2π ambiguity problem in phase unwrapping.

Fabrication and in vitro investigation of hyperbranched poly-lysine-grafted warp knitted polypropylene sling for potential treatment of stress urinary incontinence.

Polypropylene (PP) sling implantation is the most commonly performed procedure for women with stress urinary incontinence (SUI). However, concerns have arisen regarding complications caused by slings, including the common issue of erosion, which can be attributed to various factors such as the body's response and bacterial contamination. To address these concerns, we have developed a rectangular mesh self-locking edge sling with a large pore size and lightweight design. Promising results have been obtained from preliminary in vivo mechanical reliability tests, including uniaxial tensile tests. In comparative in vitro fixed load tensile tests and simulated Tension-free Vaginal Tape (TVT) and Transobturator Vaginal Tape inside-out (TVT-O) technique tests using commercial slings, our sling demonstrated less transverse wrinkling. Both slings achieved an effective porosity of over 45% under the TVT technique. However, the commercial sling experienced a significant reduction in effective porosity during the TVT-O technique, whereas our sling maintained a stable effective porosity with minimal wrinkling. Furthermore, we successfully developed cationic hydration rejection-driven antibacterial-anti-fouling coatings on the surface of our sling by grafting hyperbranched poly-lysine (HBPL) mediated by polynorepinephrine. The HBPL coating imparts a positive charge and hydrophilicity to the sling, resulting in elevated bactericidal activity and reducing protein adhesion. An optimal grafting concentration of 20 mg mL-1 was selected, confirming the stability and biocompatibility of the sling coating. This coating is expected to reduce the likelihood of postoperative erosion. Overall, our research represents significant advancements in improving the safety and performance of PP slings for stress urinary incontinence, potentially leading to a reduction in complications following surgery.

Latest Trends on the Attenuation of Systemic Foreign Body Response and Infectious Complications of Synthetic Hernia Meshes.

Throughout the past few years, hernia incidence has remained at a high level worldwide, with more than 20 million people requiring hernia surgery each year. Synthetic hernia meshes play an important role, providing a microenvironment that attracts and harbors host cells and acting as a permanent roadmap for intact abdominal wall reconstruction. Nevertheless, it is still inevitable to cause not-so-trivial complications, especially chronic pain and adhesion. In long-term studies, it was found that the complications are mainly caused by excessive fibrosis from the foreign body reaction (FBR) and infection resulting from bacterial colonization. For a thorough understanding of their complex mechanism and providing a richer background for mesh development, herein, we discuss different clinical mesh products and explore the interactions between their structure and complications. We further explored progress in reducing mesh complications to provide varied strategies that are informative and instructive for mesh modification in different research directions. We hope that this work will spur hernia mesh designers to step up their efforts to develop more practical and accessible meshes by improving the physical structure and chemical properties of meshes to combat the increasing risk of adhesions, infections, and inflammatory reactions. We conclude that further work is needed to solve this pressing problem, especially in the analysis and functionalization of mesh materials, provided of course that the initial performance of the mesh is guaranteed.

Circular fringe projection profilometry: erratum.

In this erratum, an error in Eq. (14) in our recently published Letter [Opt. Lett.41, 4951 (2016)10.1364/OL.41.004951OPLEDP0146-9592] is corrected.

Circular fringe projection profilometry.

In this Letter, a novel three-dimensional (3D) measurement method, called the circular fringe projection profilometry (CFPP), is proposed. Similar to the conventional fringe projection profilometry, CFPP also requires fringe pattern projection and capture, phase demodulation, and phase unwrapping. However, it works with a totally different mechanism. CFPP recovers the height of a point by calculating its distance to the optical center of a projector along the optical axis. This distance is calculated with the aid of the divergence angle of a projected light ray and the distance between the measured point and the optical axis. The distance between the measured point and the optical axis is detected by a camera with telecentric lenses, while the divergence angle can be calculated from the phase of a captured circular fringe pattern. The validity of CFPP is confirmed by a set of experiments.