Optron: Better Medical Image Registration via Optimizing in the Loop

Previously, in the field of image registration, there are mainly two paradigms, the traditional optimization-based methods, and the deep-learning-based methods. We designed a robust training architecture that is simple and generalizable. We present Optron, a general training architecture incorporating the idea of optimizing-in-the-loop. By iteratively optimizing the prediction result of a deep learning model through a plug-and-play optimizer module in the training loop, Optron introduces pseudo ground truth to an unsupervised training process. This pseudo supervision provides more direct guidance towards model training compared with unsupervised methods. Utilizing this advantage, Optron can consistently improve the models' performance and convergence speed. We evaluated our method on various combinations of models and datasets, and we have achieved state-of-the-art performance on the IXI dataset, improving the previous state-of-the-art method TransMorph by a significant margin of +1.6% DSC. Moreover, Optron also consistently achieved positive results with other models and datasets. It increases the validation DSC on IXI for VoxelMorph and ViT-V-Net by +2.3% and +2.2% respectively, demonstrating our method's generalizability. Our implementation is publicly available at https://github.com/miraclefactory/optronComment: 10 pages, 5 figures, 4 table

A knee-point-based evolutionary algorithm using weighted subpopulation for many-objective optimization

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Among many-objective optimization problems (MaOPs), the proportion of nondominated solutions is too large to distinguish among different solutions, which is a great obstacle in the process of solving MaOPs. Thus, this paper proposes an algorithm which uses a weighted subpopulation knee point. The weight is used to divide the whole population into a number of subpopulations, and the knee point of each subpopulation guides other solutions to search. Besides, Additionally, the convergence of the knee point approach can be exploited, and the subpopulation-based approach improves performance by improving the diversity of the evolutionary algorithm. Therefore, these advantages can make the algorithm suitable for solving MaOPs. Experimental results show that the proposed algorithm performs better on most test problems than six other state-of-the-art many-objective evolutionary algorithms

3D bioactive composite scaffolds for bone tissue engineering

Bone is the second most commonly transplanted tissue worldwide, with over four million operations using bone grafts or bone substitute materials annually to treat bone defects. However, significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma, cancer, infection and arthritis. Developing bioactive three-dimensional (3D) scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering (BTE). A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts. However, individual groups of materials including polymers, ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone. Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds. This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers, hydrogels, metals, ceramics and bio-glasses in BTE. Scaffold fabrication methodology, mechanical performance, biocompatibility, bioactivity, and potential clinical translations will be discussed

Four-Arm δ‑Ornithine-Based Polypeptoids Resensitize Voriconazole against Azole-Resistant C. albicans

Worldwide Candida albicans infections cause a huge burden in healthcare and the efficacy of traditional antifungals is diminished because of the rapid development of antifungal resistance. It is necessary to develop new antifungals or new strategies to make multidrug-resistant (MDR) C. albicans to resensitize to existing antifungal drugs. In this work, a series of 4-arm polypeptoids (FAPs) were synthesized through grafting linear ε-l-lysine or δ-ornithine-based oligopeptides to a trimeric lysine core. The most potent 4R-O7 exhibited excellent activities toward three sensitive and two MDR C. albicans strains with MIC values as low as 24–48 μg/mL (vs 375 μg/mL for ε-polylysine, ε-PL). The mechanism studies revealed that 4R-O7 penetrated the cell membrane and generated ROS to kill cells. 4R-O7 exhibited a synergistic effect (FICI < 0.5) with voriconazole (VOR) and also assisted VOR to restore its efficacy to MDR C. albicans. In addition, the combined use of 4R-O7 and VOR significantly improved the elimination efficacy of mature C. albicans biofilms and enhanced the potency in a mouse subcutaneous C. albicans infection model

Enhanced Ferromagnetism in Nanoscale GaN:Mn Wires Grown on GaN Ridges

The problem of weak magnetism has hindered the application of magnetic semiconductors since their invention, and on the other hand, the magnetic mechanism of GaN-based magnetic semiconductors has been the focus of long-standing debate. In this work, nanoscale GaN:Mn wires were grown on the top of GaN ridges by metalorganic chemical vapor deposition (MOCVD), and the superconducting quantum interference device (SQUID) magnetometer shows that its ferromagnetism is greatly enhanced. Secondary ion mass spectrometry (SIMS) and energy dispersive spectroscopy (EDS) reveal an obvious increase of Mn composition in the nanowire part, and transmission electron microscopy (TEM) and EDS mapping results further indicate the correlation between the abundant stacking faults (SFs) and high Mn doping. When further combined with the micro-Raman results, the magnetism in GaN:Mn might be related not only to Mn concentration, but also to some kinds of built-in defects introduced together with the Mn doping or the SFs