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Purpose: Total Knee Arthroplasty (TKA) is a highly invasive procedure causing severe postoperative pain, which hampers early mobility. Effective pain management is crucial for optimal recovery. This study aimed to evaluate how adductor canal block (ACB) and femoral nerve block (FNB) affect opioid use and inflammation factor levels in elderly TKA patients. Methods: This prospective observational study included 120 patients who received TKA, and divided them into three groups, based on the different nerve block technique: ACB, FNB, and no intervention before general anesthesia (CON). Postoperative opioid consumption, pain assessment, inflammation factor, knee function recovery and other clinical indicators were recorded. Results: The CON group had significantly higher cumulative sufentanil consumption compared to the ACB and FNB groups at both 12 h and 48h postoperative (P< 0.001). Compared with the CON group, the ACB and FNB groups persistently had lower pain scores until 12 h at rest and 24 h during motion after surgery. The ACB group showed significantly lower serum concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) compared to the CON group at 24 h postoperative (P=0.017, P=0.009), and IL-6 levels remained significantly lower at 72 h postoperative (P=0.005). Both ACB and FNB groups achieved earlier ambulation compared to the CON group (P=0.002). On the first day postoperative, both the ACB and FNB groups showed significantly better knee motion (P< 0.001), quadriceps strength (P< 0.001), and daily mobilization (P< 0.001) compared to the CON group. Additionally, the ACB group exhibited superior quadriceps strength (P< 0.001) and daily mobilization (P< 0.001) compared to the FNB group. Conclusion: The ACB and FNB groups exhibited comparable clinical efficacy outcomes in terms of pain scores and opioid consumption. However, the ACB group experienced reduced postoperative inflammation and improved knee recovery, especially in quadriceps strength. [ABSTRACT FROM AUTHOR]

In this study, equimolar amounts of poly(l‐lactic acid) (PLLA) and poly(d‐lactide acid) (PDLA) were melt‐blended with PBSA, to obtain a novel and environmentally friendly PBSA/sc‐PLA blend, through in situ formation of stereo‐complex poly(lactic acid) (sc‐PLA). Differential scanning calorimetry and wide‐angle X‐ray diffractometry confirmed the formation of sc‐PLA in PBSA matrix. The sc‐PLA was uniformly dispersed in PBSA matrix. Up to 20 wt% sc‐PLA concentration, the PBSA/sc‐PLA blends showed solid‐like flow behavior in the low‐frequency region. Moreover, sc‐PLA could reinforce the PBSA matrix. The Young's modulus, yield strength, and storage modulus of PBSA/sc‐PLA blend increased with increase in sc‐PLA content. In addition, the heat deflection temperatures of PBSA/sc‐PLA blends increased on incorporation of sc‐PLA, thus enhancing the heat resistance. Compared with neat PBSA, the hydrolytic degradation of PBSA/sc‐PLA blends was improved. This work provides an effective strategy to obtain high performance PBSA materials and expand the application scope of PBSA. [ABSTRACT FROM AUTHOR]

HVDC cable accessories with environment-friendly insulating material and flexible compatibility other than ethylene propylene diene monomer (EPDM) are demanded in the global market. In this paper, the authors present their newly developed silicone rubber (SiR) insulated cable joints and terminations as a potential answer to that call. Simulation models were built in computer programs. Three most venerable spots in the insulator were identified. SiR insulated accessories with optimised conductivity were produced and tested according to Cigre TB 496 and IEC 62895:2017. The test objects passed the type test with good success. It proved that with proper design, manufacturing and installation, SiR insulated cable accessories are able to provide good service in the power system networks.

The usage of a guided bone regeneration (GBR) membrane that prevents the ingrowth of fibroblast cells and enhances the regeneration rate is an effective strategy for bone regeneration therapy. Herein, LAPONITE® (LAP) nanoplatelets, a bioactive clay with good osteoinductivity, were incorporated within a regenerated silk fibroin (RSF) microfibrous mat via electrospinning. The as-prepared RSF-LAP hybrid microfibrous mats had an interconnected structure with pore size significantly smaller than that of the fibroblast cells, leading to an effective prevention of fibroblast cell ingrowth into the defect sites. As per the water contact angle measurements, the incorporation of LAP significantly improved the hydrophilicity of the RSF microfibrous mats. The in vitro cell experiment results show that the RSF-LAP microfibrous mats exhibited better cell adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs) than the pristine RSF microfibrous mats. Moreover, the RSF-LAP microfibrous mats promoted osteogenic differentiation by upregulating alkaline phosphatase (ALP) activity and osteo-specific gene expression. Therefore, the results suggest that this easily fabricated LAP-incorporated RSF microfibrous mat has great potential to be a promising biomaterial for GBR applications. [ABSTRACT FROM AUTHOR]

Due to the rapid development of the voltage-source converter (VSC), the demands for HVDC cables have increased significantly. Although more than ten VSC-HVDC projects are under construction and many more are in operations globally, the testing criteria for HVDC XLPE cables are mainly referenced to test guideline TB 496 recommended by CIGRE. Due to the large stray capacitance of the VSC-HVDC cables, the switching impulse overvoltage stress of the cables is the main electrical parameter concerned, a unified overvoltage factor of 2.1 p.u. being generally accepted. However, the switching impulse overvoltage stress of a VSC-HVDC cable system depends on not only the VSC topology but also the cable parameters and the volt-ampere characteristics of the dc cable surge arresters used. This paper studies the switching impulse overvoltage stresses for the dc cable system of a symmetrical monopole VSC-HVDC transmission system using the modular multilevel converter technology. The studies were performed according to the key technical parameters for a typical 1000-MW/320-kV VSC-HVDC transmission scheme, the XLPE dc cable links being assumed. The results show that a switching impulse overvoltage level of 2.3 p.u. should be applied during the type test of the overvoltage capability of the HVDC cables. [ABSTRACT FROM AUTHOR]

The most critical positions of a prefabricated cable accessory, from the electrical point of view, are the interfaces between the stress cone and its surroundings. Accordingly, the contact pressure on those interfaces needs to be carefully designed to assure both good dielectric strength and smooth installation of the stress cone. Nevertheless, since stress cones made from rubber are under large deformation after installation, their internal stress distribution is neither practical to measure directly by planting sensors, nor feasible to compute accurately with the conventional theory of linear structural mechanics. This paper presents one sophisticated method for computing the mechanical stress distribution in rubber stress cones of cable accessories by employing hyperelastic models in a computation model based on the finite element method. This method offers accurate results for rubber bodies of complex geometries and large deformations. Based on the method, a case study of a composite prefabricated termination for extruded cables is presented, and the sensitivity analysis is given as well. [ABSTRACT FROM AUTHOR]