The modified capsular arthroplasty for young patients with developmental dislocation of the hip.

The present study aimed to investigate the clinical results of the modified Codivilla-Hey Groves-Colonna capsular arthroplasty in the treatment of young patients with developmental dislocation of the hip. We retrospectively evaluated 90 patients (92 hips) who underwent the modified capsular arthroplasty from June 2012 to June 2021. Hips were evaluated using the modified hip Harris score (mHHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and the 12-item International Hip Outcome Tool (iHOT-12). The Tönnis osteoarthritis grade and the Severin classification system were used to assess the radiographic outcomes. The average age was 15.7 years (range: 8-26 years). The mean pre-operative mHHS, the WOMAC score and the iHOT-12 score were 83.03, 14.05 and 52.79, respectively. The patients were followed for a mean of 41.1 months (range: 12.1-120.9 months). The patients had a mean mHHS of 83.61 (range: 31.2-97), a WOMAC score of 16.41 (range: 0-51) and an iHOT-12 score of 64.81 (range: 12.9-98.2) at the final follow-up. Capsular thickness had a positive predication on the final functional outcomes. The excellent/good rate of radiological reduction was 79.3%. More than 60% of patients had no/slight osteoarthritis. A total of 54 hips (58.7%) had superior radiographic outcomes. The risk factors for inferior radiographic outcomes were capsular quality (odds ratio [OR]: 0.358, 95% confidence interval [CI]: 0.113-0.931) and capsular thickness (OR: 0.265, 95% CI: 0.134-0.525). Joint stiffness was the most common complication (14.1%). We confirmed the efficacy of this procedure in the treatment of developmental hip dislocation. Patients with poor capsular quality are not suitable for this procedure. With suitable selection according to indications, this procedure can restore the hip rotation center with a low incidence of femoral head necrosis or severe osteoarthritis

Intrinsic Correlation between Hardness and Elasticity in Polycrystalline Materials and Bulk Metallic Glasses

Though extensively studied, hardness, defined as the resistance of a material to deformation, still remains a challenging issue for a formal theoretical description due to its inherent mechanical complexity. The widely applied Teter's empirical correlation between hardness and shear modulus has been considered to be not always valid for a large variety of materials. Here, inspired by the classical work on Pugh's modulus ratio, we develop a theoretical model which establishes a robust correlation between hardness and elasticity for a wide class of materials, including bulk metallic glasses, with results in very good agreement with experiment. The simplified form of our model also provides an unambiguous theoretical evidence for Teter's empirical correlation.Comment: 10 pages, 4 figures and 3 table

Physical Transient Photoresistive Variable Memory Based on Graphene Quantum Dots

Biomaterials have attracted attention as a major material for biodegradable and transient electronic devices. In this work, biocompatible gelatin-doped graphene quantum dot films are reported as active layer switching memories with good electrical properties and physical transient properties. Such nonvolatile memory devices have write-once-read-many electrical properties and a concentrated distribution of low-resistance and high-resistance states. It provides a solution for the current obstacle of resistive memory storage and computing integration. Based on the sensitivity of the device to ultraviolet light, the “OR gate” logic operation is completed. Furthermore, the active layer can be dissolved in deionized water within 15 min, and the gelatin substrate-based device can be destroyed immediately in water, indicating the potential biodegradation and physical transient properties of our fabricated device. Biocompatible memory devices are environmentally friendly, sustainable for safe storage, and low-cost, making them ideal for storage applications

Flexible Transient Resistive Memory Based on Biodegradable Composites

Physical transient electronics have attracted more attention as the basis for building green electronics and biomedical devices. However, there are difficulties in selecting materials for the fabricated devices to take into account both biodegradability and high performance. In this paper, a physically transient resistive random-access memory (RRAM) device was fabricated by using egg protein and graphene quantum dot composites as active layers. The sandwich structure composed of Al/EA:GQD/ITO shows a good write-once-multiple-read memory characteristic, and the introduced GQD improves the switching current ratio of the device. By using the sensitivity of GQDs to ultraviolet light, the logic operation of the “OR gate” is completed. Furthermore, the device exhibits a physical transient behavior and good biodegradability due to the dissolution behavior in deionized water. These results suggest that the device is a favorable candidate for the construction of memory elements for transient electronic systems

Physically Transient, Flexible, and Resistive Random Access Memory Based on Silver Ions and Egg Albumen Composites

Organic-resistance random access memory has high application potential in the field of next-generation green nonvolatile memory. Because of their biocompatibility and environmental friendliness, natural biomaterials are suitable for the fabrication of biodegradable and physically transient resistive switching memory devices. A flexible memory device with physically transient properties was fabricated with silver ions and egg albumen composites as active layers, which exhibited characteristics of write-once-read-many-times (WORM), and the incorporation of silver ions improved the ON/OFF current ratio of the device. The device can not only complete the logical operations of “AND gate” and “OR gate”, but its active layer film can also be dissolved in deionized water, indicating that it has the characteristics of physical transients. This biocompatible memory device is a strong candidate for a memory element for the construction of transient electronic systems

Dual-Tunable Memristor Based on Carbon Nanotubes and Graphene Quantum Dots

Nanocarbon materials have the advantages of biocompatibility, thermal stability and chemical stability and have shown excellent electrical properties in electronic devices. In this study, Al/MWCNT:GQD/ITO memristors with rewritable nonvolatile properties were prepared based on composites consisting of multiwalled carbon nanotubes (MWCNTs) and graphene quantum dots (GQDs). The switching current ratio of such a device can be tuned in two ways. Due to the ultraviolet light sensitivity of GQDs, when the dielectric material is illuminated by ultraviolet light, the charge capture ability of the GQDs decreases with an increasing duration of illumination, and the switching current ratio of the device also decreases with an increasing illumination duration (103–10). By exploiting the charge capture characteristics of GQDs, the trap capture level can be increased by increasing the content of GQDs in the dielectric layer. The switching current ratio of the device increases with increasing GQD content (10–103). The device can be programmed and erased more than 100 times; the programmable switching state can withstand 105 read pulses, and the retention time is more than 104 s. This memristor has a simple structure, low power consumption, and enormous application potential for data storage, artificial intelligence, image processing, artificial neural networks, and other applications

High-Performance Biomemristor Embedded with Graphene Quantum Dots

By doping a dielectric layer material and improving the device’s structure, the electrical characteristics of a memristor can be effectively adjusted, and its application field can be expanded. In this study, graphene quantum dots are embedded in the dielectric layer to improve the performance of a starch-based memristor, and the PMMA layer is introduced into the upper and lower interfaces of the dielectric layer. The experimental results show that the switching current ratio of the Al/starch: GQDs/ITO device was 102 times higher than that of the Al/starch/ITO device. However, the switching current ratio of the Al/starch: GQDs/ITO device was further increased, and the set voltage was reduced (−0.75 V) after the introduction of the PMMA layer. The introduction of GQDs and PMMA layers can regulate the formation process of conductive filaments in the device and significantly improve the electrical performance of the memristor

Comparison of 2.5D and 3D Quantification of Femoral Head Coverage in Normal Control Subjects and Patients with Hip Dysplasia.

Hip dysplasia is characterized by insufficient femoral head coverage (FHC). Quantification of FHC is of importance as the underlying goal of the surgery to treat hip dysplasia is to restore a normal acetabular morphology and thereby to improve FHC. Unlike a pure 2D X-ray radiograph-based measurement method or a pure 3D CT-based measurement method, previously we presented a 2.5D method to quantify FHC from a single anteriorposterior (AP) pelvic radiograph. In this study, we first quantified and compared 3D FHC between a normal control group and a patient group using a CT-based measurement method. Taking the CT-based 3D measurements of FHC as the gold standard, we further quantified the bias, precision and correlation between the 2.5D measurements and the 3D measurements on both the control group and the patient group. Based on digitally reconstructed radiographs (DRRs), we investigated the influence of the pelvic tilt on the 2.5D measurements of FHC. The intraclass correlation coefficients (ICCs) for absolute agreement was used to quantify interobserver reliability and intraobserver reproducibility of the 2.5D measurement technique. The Pearson correlation coefficient, r, was used to determine the strength of the linear association between the 2.5D and the 3D measurements. Student's t-test was used to determine whether the differences between different measurements were statistically significant. Our experimental results demonstrated that both the interobserver reliability and the intraobserver reproducibility of the 2.5D measurement technique were very good (ICCs > 0.8). Regression analysis indicated that the correlation was very strong between the 2.5D and the 3D measurements (r = 0.89, p 0.05). The results of this study provided convincing evidence demonstrating the validity of the 2.5D measurements of FHC from a single AP pelvic radiograph and proved that it could serve as a surrogate for 3D CT-based measurements. Thus it may be possible to use this method to avoid a CT scan for the purpose of estimating 3D FHC in diagnosis and post-operative treatment evaluation of patients with hip dysplasia