Total hip revision with custom-made spacer and prosthesis: A case report.

BACKGROUND: Both periprosthetic joint infections (PJIs) and severe femoral segmental defects are catastrophic complications of total hip arthroplasty (THA), and both present a significant challenge in revisional surgery. There are limited data available to guide clinical decision making when both occur concurrently. CASE SUMMARY: A 61-year-old woman presented with a 6-mo history of a sinus tract at the site of her original THA incision. Radiological imaging revealed a total hip joint implant with an ipsilateral segmental femoral defect. Based on histological, radiological, laboratory, and clinical features, a diagnosis of concurrent chronic PJI and segmental femoral defect (Type IIIB, Paprosky classification) was made. After multidisciplinary team discussion, three-dimensional (3D)-printed, custom-made antibiotic spacers were created that could be used to mold antibiotic-loaded cement spacer. These were placed following PJI debridement in the first stage of revision surgery. After the PJI was eliminated, a 3D-printed, custom-made, femoral prosthesis was created to repair the considerable femoral defect. After 20-mo follow-up, the patient had excellent functional outcomes with a near-normal range of hip movement. So far, neither evidence of recurrent infection nor loosening of the prosthesis has been observed. CONCLUSION: We describe a case of "two-stage, custom-made" total hip revision to treat PJI with a concurrent segmental femoral defect. Use of a personalized, 3D-printed spacer and proximal femoral prosthesis led to satisfactory hip function and no early postoperative complications. Use of a customized implant provides surgeons with an alternative option for patients where no suitable spacer or implant is available. However, the long-term function, longevity, and cost-effectiveness of the use of custom-made prostheses have yet to be fully explored.

Analysis of risk factors associated with flexor pollicis longus injury after volar plating of distal radius fractures.

OBJECTIVE: This study was performed to analyze the risk factors associated with flexor pollicis longus (FPL) attrition or rupture after volar plating of distal radius fractures. METHODS: Three hundred thirty-eight patients with distal radius fractures were included in this retrospective study. Univariate analysis and multivariate logistic regression analysis were performed to predict risk factors. RESULTS: Univariate analysis showed that sex, volar tilt, the Soong grade, the plate-to-critical line distance (PCLD), the plate-to-volar rim distance (PVRD), and the time of plate removal were significantly associated with FPL attrition or rupture. Multivariate logistic regression analysis demonstrated that decreased volar tilt, Soong grade 2, PCLD of >2 mm, PVRD of <3 mm, and plate removal at ≥1 year were the risk factors significantly associated with FPL attrition or rupture. CONCLUSIONS: Reduced volar tilt, Soong grade 2, PCLD of >2 mm, and PVRD of <3 mm appear to be risk factors that are significantly associated with FPL attrition or rupture. The findings of this study also suggest that the risk of tendon rupture is lower if a Soong grade 2 plate is removed, the PCLD is >2 mm, the PVRD is <3 mm, or reduced volar tilt is achieved earlier (at <1 year).

Construction of polymeric carbon nitride and dibenzothiophene dioxide-based intramolecular donor-acceptor conjugated copolymers for photocatalytic H2 evolution.

Polymeric carbon nitride (g-C3N4) has succeeded as a striking visible-light photocatalyst for solar-to-hydrogen energy conversion, owing to its economical attribute and high stability. However, due to the lack of sufficient solar-light absorption and rapid photo-generated carrier recombination, the photocatalytic activity of raw g-C3N4 is still unsatisfactory. Herein, new intramolecular g-C3N4-based donor-acceptor (D-A) conjugated copolymers have been readily synthesized by a nucleophilic substitution/condensation reaction between urea and 3,7-dihydroxydibenzo[b,d]thiophene 5,5-dioxide (SO), which is strategically used to improve the photocatalytic hydrogen evolution performance. The experimental results demonstrate that CNSO-X not only improves light utilization, but also accelerates the spatial separation efficiency of the photogenerated electron-hole pairs and increases the wettability with the introduction of SO. In addition, the adsorption energy barrier of CNSO-X to H* has a significant reduction via theoretical calculation. As expected, the CNSO-20 realizes the best photocatalytic H2 evolution activity of 251 µmol h-1 (50 mg photocatalyst, almost 8.5 times higher than that of pure CN) with an apparent quantum yield of 10.16% at 420 nm, which surpasses most strategies for the organic molecular copolymerization of carbon nitride. Therefore, this strategy opens up a novel avenue to develop highly efficient g-C3N4 based photocatalysts for hydrogen production.

Cascading Failure Analysis on Shanghai Metro Networks: An Improved Coupled Map Lattices Model Based on Graph Attention Networks.

Analysis of the robustness and vulnerability of metro networks has great implications for public transport planning and emergency management, particularly considering passengers' dynamic behaviors. This paper presents an improved coupled map lattices (CMLs) model based on graph attention networks (GAT) to study the cascading failure process of metro networks. The proposed model is applied to the Shanghai metro network using the automated fare collection (AFC) data, and the passengers' dynamic behaviors are simulated by GAT. The quantitative cascading failure analysis shows that Shanghai metro network is robust to random attacks, but fragile to intentional attacks. Moreover, there is an approximately normal distribution between instant cascading failure speed and time step and the perturbation in a station which leads to steady state is approximately a constant. The result shows that a station surrounded by other densely distributed stations can trigger cascading failure faster and the cascading failure triggered by low-level accidents will spread in a short time and disappear quickly. This study provides an effective reference for dynamic safety evaluation and emergency management in metro networks.

A self-assembled perylene diimide nanobelt for efficient visible-light-driven photocatalytic H2 evolution.

In this communication, a self-assembled supramolecular system consisting of phosphoric acid substituted perylene diimide (P-PMPDI) has been successfully developed for highly efficient photocatalytic hydrogen evolution. Compared with a carboxylic substituent perylene diimide (P-CMPDI), P-PMPDI showed a superior H2 evolution reaction rate of 11.7 mmol g-1 h-1 and a recorded apparent quantum yield (AQY) of 2.96% at 550 nm.

Enhanced Photocurrent via π-Bridge Extension of Perylenemonoimide-Based Dyes for p-Type Dye-Sensitized Solar Cells and Photoelectrochemical Cells.

Two dyes TB and TSB containing triphenylamine as the donor and perylenemonoimide as the acceptor, with and without bithiophene as π-bridge, respectively, were successfully prepared and characterized for p-type dye-sensitized solar cells (p-DSSCs) and dye-sensitized photoelectrochemical cells (DS-PECs). As a result, TSB with bithiophene π-bridge exhibited a broader absorption spectrum and a higher molar extinction coefficient than TB. Furthermore, the photocurrents of p-DSSCs and DS-PECs for the dye TSB were increased by 26.9 and 32.9%, respectively, compared with those of the dye TB. Meanwhile, the electrochemical impedance spectroscopy of the TSB-based p-DSSC showed the smaller charge-transfer resistance and larger hole lifetime because the longer π-bridge facilitated charge transfer and separation within the dye molecule and effectively prevented the hole recombination process at the NiO/dye interface, resulting in improvement of photoelectric performance. Hence, these results show that the π-bridge extension of dyes has a promising effect on the photocurrent improvement of p-DSSCs and DS-PECs.