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Key Clinical Message Spine surgeons should be aware of the possibility of anterior displacement of the grafted bone during PLIF and the potential for severe complications that may arise because of such displacement so that preparations can be made for a proper response. Abstract We report two cases of anterior displacement of the grafted bone after posterior lumbar interbody fusion (Graphical Abstract A‐D). The patients did not require additional surgery. The anterior migration of grafted bone or cage can cause damage to anterior organs and blood vessels. Therefore, a careful surgical procedure is necessary.

Accurate neural networks can be found just by pruning a randomly initialized overparameterized model, leaving out the need for any weight optimization. The resulting subnetworks are small, sparse, and ternary, making excellent candidates for efficient hardware implementation. However, finding optimal connectivity patterns is an open challenge. Based on the evidence that residual networks may be approximating unrolled shallow recurrent neural networks, we conjecture that they contain better candidate subnetworks at inference time when explicitly transformed into recurrent architectures. This hypothesis is put to the test on image classification tasks, where we find subnetworks within the recurrent models that are more accurate and parameter-efficient than both the ones found within feedforward models and than the full models with learned weights. Furthermore, random recurrent subnetworks are tiny: under a simple compression scheme, ResNet-50 is compressed without a drastic loss in performance to $48.55\times $ less memory size, fitting in under 2 megabytes. Code available at: https://github.com/Lopez-Angel/hidden-fold-networks.

Ambient intelligence aims to actualize the environment that sense and utilize information around us without making us perceive the underlying systems. This work extends this concept by allowing us to track the movement and orientation of people and objects instantly. The proposed system can sense and let us know, for example, who met or talked to each other frequently, to whom s/he is often facing in the meeting, what stuffs people often use, where the person left his/her belongings, etc. Such information will help the system to understand the behavior patterns of each person and consequently can support and improve the personal life of users and even their mutual relationship. This article proposes an instant indoor magnetic tracking system that enables us to track the movement and orientation of people and objects by only attaching tiny electronic trackers to them. The size of the prototyped tracker is only 25.4mm × 25.4mm × 10.0mm, and hence it can be readily attached to almost anything and immediately activated. Evaluation results show that the proposed system applies to both room-scale tracking and tabletop scale tracking with 6 DoF (Degrees of Freedom).

Resin–dentin bonding was first achieved through mechanical hybridization between resin and collagen fibrils using a functional monomer containing resin system. In the last decade, new adhesive resin systems were frequently released onto the market within a short-period of time. Before and after commercialization, the bond integrity has been tested by bond tests, and leakage evaluation by researchers, but it is very difficult for clinicians to obtain a comprehensive, up-to-date understanding of their nature and degradation. Although newly developed adhesive resins have attempted to improve the bond strength at least in the first 24 h after bonding, the long-term durability of the bonds has not yet been established analytically. However, numerous recent studies have shown micromorphological evidence of biodegradation of resin–dentin bonds, due to hydrolysis of the resin and collagen fibrils within the bonds. This review mainly summarizes the most recent work in biodegradation of resin–dentin bonds based on micromorphological analyses of data obtained by scanning and transmission electron microscopy.

Chemical modification of gelatin using epigallocatechin gallate (EGCG) promotes bone formation in vivo. However, further improvements are required to increase the mechanical strength and bone-forming ability of fabricated EGCG-modified gelatin sponges (EGCG-GS) for practical applications in regenerative therapy. In the present study, we investigated whether vacuum heating-induced dehydrothermal cross-linking of EGCG-GS enhances bone formation in critical-sized rat calvarial defects. The bone-forming ability of vacuum-heated EGCG-GS (vhEGCG-GS) and other sponges was evaluated by micro-computed tomography and histological staining. The degradation of sponges was assessed using protein assays, and cell morphology and proliferation were verified by scanning electron microscopy and immunostaining using osteoblastic UMR106 cells in vitro. Four weeks after the implantation of sponges, greater bone formation was detected for vhEGCG-GS than for EGCG-GS or vacuum-heated gelatin sponges (dehydrothermal cross-linked sponges without EGCG). In vitro experiments revealed that the relatively low degradability of vhEGCG-GS supports cell attachment, proliferation, and cell–cell communication on the matrix. These findings suggest that vacuum heating enhanced the bone forming ability of EGCG-GS, possibly via the dehydrothermal cross-linking of EGCG-GS, which provides a scaffold for cells, and by maintaining the pharmacological effect of EGCG.

The development of technologies to promote vascularization of engineered tissue would drive major developments in tissue engineering and regenerative medicine. Recently, we succeeded in fabricating three-dimensional (3D) cell constructs composed of mesenchymal stem cells (MSCs). However, the majority of cells within the constructs underwent necrosis due to a lack of nutrients and oxygen. We hypothesized that incorporation of vascular endothelial cells would improve the cell survival rate and aid in the fabrication of biomimetic bone tissues in vitro. The purpose of this study was to assess the impact of endothelial cells combined with the MSC constructs (MSC/HUVEC constructs) during short- and long-term culture. When human umbilical vein endothelial cells (HUVECs) were incorporated into the cell constructs, cell viability and growth factor production were increased after 7 days. Furthermore, HUVECs were observed to proliferate and self-organize into reticulate porous structures by interacting with the MSCs. After long-term culture, MSC/HUVEC constructs formed abundant mineralized matrices compared with those composed of MSCs alone. Transmission electron microscopy and qualitative analysis revealed that the mineralized matrices comprised porous cancellous bone-like tissues. These results demonstrate that highly biomimetic bone tissue can be fabricated in vitro by 3D MSC constructs incorporated with HUVECs.