Acute myocardial infarction (AMI), also recognized as a “heart attack,” is one leading cause of death globally, and cardiac myoglobin (cMb), an important cardiac biomarker, is used for the early ...assessment of AMI. This paper presents an ultrasensitive, label-free electrochemical aptamer-based sensor (aptasensor) for cMb detection using polyethylenimine (PEI)-functionalized reduced graphene oxide (PEI–rGO) thin films. PEI, a cationic polymer, was used as a reducing agent for graphene oxide (GO), providing highly positive charges on the rGO surface and allowing direct immobilization of negatively charged single-strand DNA aptamers against cMb via electrostatic interaction without any linker or coupling chemistry. The presence of cMb was detected on Mb aptamer-modified electrodes using differential pulse voltammetry via measuring the current change due to the direct electron transfer between the electrodes and cMb proteins (Fe3+/Fe2+). The limits of detection were 0.97 pg mL–1 (phosphate-buffered saline) and 2.1 pg mL–1 (10-fold-diluted human serum), with a linear behavior with logarithmic cMb concentration. The specificity and reproducibility of the aptasensors were also examined. This electrochemical aptasensor using polymer-modified rGO shows potential for the early assessment of cMb in point-of-care testing applications.
One of the greatest challenges for widespread utilization of solar energy is the low conversion efficiency, motivating the needs of developing more innovative approaches to improve the design of ...solar energy conversion equipment. Solar cell is the fundamental component of a photovoltaic (PV) system. Solar cell's precise modelling and estimation of its parameters are of paramount importance for the simulation, design, and control of PV system to achieve optimal performances. It is nontrivial to estimate the unknown parameters of solar cell due to the nonlinearity and multimodality of search space. Conventional optimization methods tend to suffer from numerous drawbacks such as a tendency to be trapped in some local optima when solving this challenging problem. This paper aims to investigate the performance of eight state-of-the-art metaheuristic algorithms (MAs) to solve the solar cell parameter estimation problem on four case studies constituting of four different types of PV systems: R.T.C. France solar cell, LSM20 PV module, Solarex MSX-60 PV module, and SS2018P PV module. These four cell/modules are built using different technologies. The simulation results clearly indicate that the Coot-Bird Optimization technique obtains the minimum RMSE values of 1.0264E-05 and 1.8694E-03 for the R.T.C. France solar cell and the LSM20 PV module, respectively, while the wild horse optimizer outperforms in the case of the Solarex MSX-60 and SS2018 PV modules and gives the lowest value of RMSE as 2.6961E-03 and 4.7571E-05, respectively. Furthermore, the performances of all eight selected MAs are assessed by employing two non-parametric tests known as Friedman ranking and Wilcoxon rank-sum test. A full description is also provided, enabling the readers to understand the capability of each selected MA in improving the solar cell modelling that can enhance its energy conversion efficiency. Referring to the results obtained, some thoughts and suggestions for further improvements are provided in the conclusion section.
Total hip arthroplasty (THA) patients with limited lumbar flexion (LF) have increased rates of dislocation. An instrumented spinal fusion is a well-recognized cause whose risk increases with ...increasing number of levels fused. However, many patients without an instrumented fusion (IF) also exhibit abnormal spinopelvic mobility. The purpose of this study was to understand the proportion of THA patients without an IF that have a stiff spine (SS) and behave as if they are surgically fused.
A retrospective analysis was performed on 6340 primary THA patients, all of whom had preoperative spinopelvic measurements. Any IF of the lumbar spine was observed on the lateral standing radiograph and recorded. SS was classified by LF ≤ 20°, and the percentage of patients with an IF and limited LF was determined.
Three hundred fifty-six (6%) patients had a SS, and only 67 (19%) had an IF. Of the entire 6340 patients, 207 (3%) had an IF. Of these 207, only 67 (32%) had a SS.
The vast majority (81%) of THA patients with a SS do not have an IF. We recommend preoperative spinopelvic assessment of all patients undergoing THA, as only a minority of those with limited LF have an IF and may otherwise be overlooked. Lumbar degenerative disc disease is common in THA patients, limits the available LF in the same way an IF might and potentially increases the risk of dislocation in this subset of patients.
III.
Critical cancer pathways often cannot be targeted because of limited efficiency crossing cell membranes. Here we report the development of a Salmonella-based intracellular delivery system to address ...this challenge. We engineer genetic circuits that (1) activate the regulator flhDC to drive invasion and (2) induce lysis to release proteins into tumor cells. Released protein drugs diffuse from Salmonella containing vacuoles into the cellular cytoplasm where they interact with their therapeutic targets. Control of invasion with flhDC increases delivery over 500 times. The autonomous triggering of lysis after invasion makes the platform self-limiting and prevents drug release in healthy organs. Bacterial delivery of constitutively active caspase-3 blocks the growth of hepatocellular carcinoma and lung metastases, and increases survival in mice. This success in targeted killing of cancer cells provides critical evidence that this approach will be applicable to a wide range of protein drugs for the treatment of solid tumors.
The optimal force applied during ligament balancing in total knee arthroplasty (TKA) is not well understood. We quantified the effect of increasing distraction force on medial and lateral gaps ...throughout the range of knee motion, both prior to and after femoral resections in tibial-first gap-balancing TKA. Twenty-five consecutive knees in 21 patients underwent robotic-assisted TKA. The posterior cruciate ligament was resected, and the tibia was cut neutral to the mechanical axis. A digital ligament tensioning tool recorded gaps and applied equal mediolateral loads of 70 N (baseline), 90 N, and 110 N from 90 degrees to full extension. A gap-balancing algorithm planned the femoral implant position to achieve a balanced knee throughout flexion. After femoral resections, gap measurements were repeated under the same conditions. Paired
-tests identified gap differences between load levels, medial/lateral compartments, and flexion angle. Gaps increased from 0 to 20 degrees in flexion, then remain consistent through 90 degrees of flexion. Baseline medial gap was significantly smaller than lateral gap throughout flexion (
<0.05). Increasing load had a larger effect on the lateral versus medial gaps (
<0.05) and on flexion versus extension gaps. Increasing distraction force resulted in non-linear and asymmetric gap changes mediolaterally and from flexion to extension. Digital ligament tensioning devices can give better understanding of the relationship between joint distraction, ligament tension, and knee stiffness throughout the range of flexion. This can aid in informed surgical decision making and optimal soft tissue tensioning during TKA.
Spinal stiffness has been shown to increase risk of dislocation due to impingement and instability. Increasing anteversion of the acetabular component has been suggested to prevent dislocation, but ...little has been discussed in terms of femoral or global offset restoration. The purpose of this study is to quantify dislocation rates after primary THA using standard versus high-offset femoral components and to determine how differences in offset affect impingement-free range of motion in a stiff spine cohort using a novel impingement model.
A total of 12,365 patients undergoing THA from 2016 to 2018 were retrospectively reviewed to determine dislocation rates and utilization of standard- versus high-offset stems. For 50 consecutive patients with spinal stiffness, a CT-based computer software impingement modeling system assessed bony or prosthetic impingement during simulated range of motion. The model was run 5 times for each patient with varying offsets. Range of motion was simulated in each scenario to determine the degree at which impingement occurred.
There were 51 dislocations for a 0.41% dislocation rate. Total utilization of high-offset stems in the entire cohort was 49%. Of those patients who sustained a dislocation, 49 (96%) utilized a standard-offset stem. The impingement modeling demonstrated 5 degrees of added range of motion until impingement for every 1 mm offset increase.
In the impingement model, high-offset stems facilitated greater ROM before bony impingement and resulted in lower dislocation rates. In the setting of high-risk THA due to spinal stiffness, surgeons should consider the use of high-offset stems and pay attention to offset restoration.
Impingement is a leading cause for instability resulting in revision total hip arthroplasty (THA). Impingement can be prosthetic, bony, or soft tissue. The purpose of this study is to investigate, ...using a virtual simulation, whether bony or prosthetic impingement presents first in well-positioned THAs.
Twenty-three patients requiring THA were planned for a ceramic-on-poly cementless construct using dynamic planning software. Cups were orientated at 45° inclination and 25° anteversion when standing. Femoral components and neck lengths were positioned to reproduce native anteversion and match contralateral leg length and offset. The type and location of impingement was then recorded with recreation of anterior and posterior impingement during standard and extreme ranges of motion (ROM).
In standard ROM, flexion produced both prosthetic and bony impingement and extension resulted in prosthetic impingement in models with lipped liners. In extreme ROM, anterior impingement was 78% bony in 32-mm articulations, and 88% bony in 36-mm articulations. Posterior impingement was 65% prosthetic in 32-mm articulations, and 55% prosthetic in 36-mm articulations. Dual mobility cups showed the greatest risk of posterior prosthetic impingement in hyperextension (74%).
In standard ROM, both bony and prosthetic impingement occurred in flexion, while prosthetic impingement occurred in extension in models with lipped liners. In hyperextension, prosthetic impingement was more common than bony impingement, and was exclusively the cause of impingement when a lip was used. In flexion, impingement was primarily bony with the use of a 36-mm head. The risk of posterior prosthetic impingement was greatest with dual mobility cups.
3.
An enhanced version of the moth flame optimization algorithm is proposed in this paper for rapid and precise parameter extraction of solar cells. The proposed OBLVMFO algorithm’s novelty lies ...primarily in the improved search strategies, where two modifications are proposed to maintain a proper balance between exploration and exploitation. Firstly, an opposition-based learning mechanism is employed to initialize the search population for the purpose of enhancing the global search. Secondly, Lévy flight distribution is used to prevent the stagnation of solutions in local minima. The implementation of intelligent rules such as OBL and Lévy flight distribution significantly improves the performance of the standard MFO. The developed OBLVMFO performed adequately and is reliable in terms of RMSE compared to other methodologies such as MFO, ALO, SCA, MRFO, and WOA. The best optimized value of RMSE achieved by OBLVMFO is 6.060E−04, 1.3600E−05, and 7.0001E−06 for STE 4/100 (polycrystalline), LSM 20 (monocrystalline), and SS2018P (polycrystalline) PV modules, respectively. The experiments performed on the benchmark test function revealed that the OBLVMFO has a 61% faster convergence speed than the standard version of MFO, which improves solution accuracy. In addition to this, two non-parametric tests: Friedman ranking and Wilcoxon rank sum are performed for the validation.
•A novel OBLVMFO algorithm is proposed for parameter extraction of solar cell models.•Two modifications are anticipated to overcome the limitations of original MFO algorithm.•The performance of OBLVMFO is tested on standard benchmark functions and practical measured datasets.•The proposed OBLVMFO algorithm is 61% faster than standard version of MFO algorithm.
Gels formed by semiflexible filaments such as most biopolymers exhibit non-linear behavior in their response to shear deformation, e.g., with a pronounced strain stiffening and negative normal ...stress. These negative normal stresses suggest that networks would collapse axially when subject to shear stress. This coupling of axial and shear deformations can have particularly important consequences for extracellular matrices and collagenous tissues. Although measurements of uniaxial moduli have been made on biopolymer gels, these have not directly been related to the shear response. Here, we report measurements and simulations of axial and shear stresses exerted by a range of hydrogels subjected to simultaneous uniaxial and shear strains. These studies show that, in contrast to volume-conserving linearly elastic hydrogels, the Young's moduli of networks formed by the biopolymers are not proportional to their shear moduli and both shear and uniaxial moduli are strongly affected by even modest degrees of uniaxial strain.
Patients with adverse spinopelvic mobility have higher complication rates following total hip arthroplasty (THA). Risk factors include a stiff lumbar spine, standing posterior pelvic tilt ≤ −10°, and ...a severe sagittal spinal deformity (pelvic incidence minus lumbar lordosis mismatch ≥20°). The purpose of this study is to define the spinopelvic risk factors and quantify the prevalence of risk factors for pathologic spinopelvic mobility.
A retrospective cohort analysis from January 2014 to February 2020 was performed on a multicenter series of 9414 primary THAs by 168 surgeons, all with preoperative spinopelvic measurements in the supine, standing, and flex-seated positions. All patients were included. The prevalence of adverse spinopelvic mobility and frequency of each spinopelvic risk factor was calculated.
The cohort was 52% female, 48% male, with an average age of 65 years. Thirteen percent of patients exhibited adverse spinopelvic mobility and 17% had one or more of the 3 risk factors. Adverse mobility was found in 35% of patients with at least 1 risk factor, 47% with at least 2 risk factors, and 57% with all 3 risk factors.
Forty-six percent of patients had spinopelvic pathology driven by one or more of the risk factors. Number of risk factors present and risk of adverse spinopelvic mobility were positively correlated, with 57% of patients with all 3 risk factors exhibiting adverse spinopelvic mobility. Although this study defines the prevalence of these risk factors in this highly selected cohort, it does not report incidence in a general THA population.
Prognostic Level IV.
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