Performance Test Research Articles

In-Plane Mechanical Properties Test of Prefabricated Composite Wall with Light Steel and Tailings Microcrystalline Foamed Plate

The tailings microcrystalline foamed plate (TMF plate), produced from industrial waste tailings, has limited research regarding its use in high-performance building walls. Its brittleness under stress poses challenges. To improve its mechanical properties, a prefabricated light steel-tailings microcrystalline foamed plate composite wall (LS-TMF composite wall) has been proposed. This LS-TMF composite wall system integrates assembly, sustainability, insulation, and decorative functions, making it a promising market option. To study the in-plane performance of the composite wall, compression and seismic performance tests were conducted. The findings indicate that the light steel keel, steel bar, and TMF plate in the composite wall demonstrated good working performance. Strengthening the TMF plate enhanced the restraint on the light steel keel and improved the composite wall’s compressive performance. Increasing the thickness of the light steel keel further improved the compressive stability. Under horizontal cyclic loading, failure occurred at the light steel keel embedding location. Increasing the strength of the TMF plate was beneficial for the seismic performance of the composite wall. This structural configuration—incorporating light steel keels, TMF plates, and fly ash blocks—enhanced thermal insulation and significantly improved in-plane stress performance. However, the splicing plate structure adversely affected the seismic performance of the composite wall.

Field-based physical fitness assessment in preschool children in China

BackgroundPhysical fitness in the preschool years is considered a marker of current and future health. Therefore, understanding physical fitness levels of preschool children is necessary. Furthermore, the use of field-based methods to measure physical fitness is essential for assessing children in authentic venues such as schools. Hence, the main purpose of this study was to describe the physical fitness of Chinese preschool children across field-based methods considering a statement of confidence intervals for reference in physical fitness in each age and genders.MethodsA total of 619 children (296 boys and 323 girls) aged 3–6 years old from China participated in the present study. Physical fitness was measured using the Chinese National Physical Fitness Measurement (CNPFM-Pre) battery, which included the tennis ball throw (upper-limb muscular strength), standing long jump (lower-limb muscular strength), shuttle run test (speed-agility), double-leg timed hop (coordination), sit-and-reach (flexibility), and balance beam test (dynamic balance).ResultsThe results revealed significant differences in gender for standing long jump (SLJ; η2 = 0.012, p = 0.007), tennis ball throw (TT; η2 = 0.081, p < 0.001), sit-and-reach (SR; η2 = 0.114, p < 0.001), and one-legged stance test (OST; η2 = 0.037, p < 0.001). Age had positive effects on all physical fitness performance tests, as the shuttle run test (η2 = 0.672, p < 0.001), SLJ (η2 = 0.513, p < 0.001), TT (η2 = 0.394, p < 0.001), double-legged timed hop test (DTH; η2 = 0.445, p < 0.001), SR (η2 = 0.069, p < 0.001), balance beam test (BBT; η2 = 0.367, p < 0.001), and OST (η2 = 0.336, p < 0.001). Older preschool children performed better than their younger counterparts in all the tests. No significant interactions between age groups and gender were found.ConclusionsThis study provided age- and gender-specific physical fitness performance data in Chinese preschool children. Gender differences in physical fitness tests performance already exists at the preschool age. All physical fitness component results increased with age in this cohort. These findings can help healthcare, physical education, and pediatric professionals understand the physical fitness development of preschool children at different ages and help design sports tasks for preschool boys and girls.

Hyaluronic Acid-Modified Luteolin-Copper Complex Nanodelivery System for Bacterial Prostatitis.

Bacterial prostatitis is a common disease of the male genitourinary system, which seriously affects the normal life and health of male patients. Antibiotics are commonly used in the clinical treatment of bacterial prostatitis, but the efficacy of fluoroquinolones is gradually declining due to the increasing drug resistance of bacteria. Hence, it is necessary to find new antibacterial drugs to treat bacterial prostatitis. Luteolin is a natural flavonoid compound with many pharmacological activities such as antibacterial and anti-inflammatory activities, but its poor water solubility and low structural stability seriously limit its clinical application. In this study, we designed a targeting drug delivery system via a luteolin-copper complex grafted with hyaluronic acid. The results of the characterization proved the successful synthesis of the system. The results of the in vitro performance test show that the system has a good antibacterial effect and excellent blood compatibility and can be effectively released under different pH conditions. The prepared nanodrug delivery system not only provides a new idea for the treatment of bacterial prostatitis but also lays a theoretical and practical foundation for the wide application of luteolin in clinical practice.

High Stability Control of a Magnetic Suspension Flywheel Based on SA-BPNN and CNN+LSTM+ATTENTION

Compared to traditional, static-based flywheel systems, vehicle-mounted magnetic suspension flywheels face more complex operating conditions, and existing control strategies usually regard disturbances in vehicles under different operating conditions to be the same problem. Therefore, it is necessary to determine the interference from complex operating conditions and reasonably distinguish among them under different operating conditions to provide flywheel systems with strong stability (the rotor offset was less than 0.025 mm). Thus, this paper proposes a high-stability control strategy for flywheels based on the classification of vehicle-driving conditions and designs its control strategy by taking the vehicle-mounted magnetic suspension flywheel with a virtual inertia spindle as an example. First, according to the different vehicle working conditions and the varying interference intensities affecting the flywheel system, the working mode is divided into four modes. Considering the obvious differences in each working mode, it is proposed to use BP neural network optimization based on the simulated annealing algorithm (SA-BPNN) to determine the flywheel’s working condition. A relatively simple neural network can improve the response speed of the whole system. It also has a good effect. Secondly, it is proposed to use deep learning models based on convolutional neural networks, long short-term memory networks and attention mechanisms (CNN+LSTM+ATTENTION) to train the corresponding control parameters under each working condition to judge and predict the control parameters under different working conditions. Three evaluation parameters are used to evaluate the training results, and all achieved good results. Finally, the classification of working conditions and performance tests are carried out. The experimental results show the effectiveness and superiority of the proposed control strategy.

Experimental and theoretical study on axial compression behaviour of the modular combined column

Between the modular units of the modular steel building, there exists a combination of the adjacent modular columns. Due to the gaps between the modular columns and the lack of horizontal connections, the integrity of the modular steel structure is weak, which limits the use of modular steel structures in high-rise buildings. This paper proposes a kind of modular combined column realized the connection of modular single columns through the connectors and concrete, which can improve the integrity of the modular steel building. The assembly process of this new modular combined column is described. For axial compressive performance tests, four modular combined column specimens were designed, each with different height or different number of connecting plates. The axial compressive bearing capacity, ductility, stiffness, and other mechanical parameters of the specimens were analyzed according to the phenomena and load-displacement curves of the test. Then, the axial compression failure mode of the modular combined column specimens is compared and analyzed in conjunction with the finite element model. The results indicate that the axial compressive performance and ductility of the combined column suggested in this research are exceptional. The connector can enhance the overall mechanical qualities of the combined column by augmenting the restraining impact of concrete. Finally, the theoretical equation of the axial compression bearing capacity of the modular combined column is obtained by employing the superposition principle, and the equation's reliability is confirmed, along with the test results and the results of the numerical analysis.

6689 A Multicentric Study for Validation of the Diagnostic Accuracy of ACR-TIRADS in a Mexican population

Abstract Disclosure: M. Romero Ibarguengoitia: None. I.A. Villarreal-Ondarza: None. J. Mercado Basurto: None. A. González Cantu: None. The diagnostic performance of ultrasonographic ACR-TIRADS classification to evaluate thyroid nodules is poorly studied in a Mexican population. The aim was to assess the diagnostic accuracy of ACR-TIRADS classification for identifying malignant thyroid nodules in adults aged &amp;gt;18 years. This retrospective research study was conducted in 4 medical centers in Northern Mexico from 2022 to 23 to obtain ACR-TIRADS classification of nodules from thyroid ultrasound. Information about Bethesda classification after fine needle aspiration and cytology from thyroidectomy was analyzed for diagnostic performance tests. A total of 160 patients were included. Thyroid nodules were classified as TIRADS 3 in 12%, TIRADS 4 in 44%, and TIRADS 5 in 41%. Twenty-six (16%) were classified as Bethesda 1, 39 (24%) were classified as Bethesda 5, and 30 (19%) were classified as Bethesda 6. The sensitivity (S) of TIRADS 4 was 41%, specificity (E) was 50%, positive predictive value (PPV) was 59%, negative predictive value (NPV) was 32%, and accuracy was 44%. The S of TIRADS 5 was 51%, E 77%, PPV 80%, NPV 47%, and accuracy of 61%. When comparing with other populations, the performance was the same as the Turkish (their accuracy was 59.93%) population but lower than a population from China (their accuracy was 86%) and Germany (PPV 100% for TIRADS 5). The proportion of malignancy in our sample compared with a reference sample from Germany was lower, 36 vs. 85% for TIRADS 3, 59 vs. 85% for TIRADS 4, and 80% vs. 100%, p&amp;lt; 0.001. Concerning Bethesda's classification, the proportion of malignancy was the same according to the reference sample from the American Thyroid Association. In conclusion, there was a moderate accuracy of the ACR-TIRADS classification system in our population, the same in comparison with the Turkish population; slightly lower than what is reported in a population from Germany and China. Presentation: 6/1/2024

Longitudinal comparison of the relationship of energy intake with body composition and physical performance in elite female basketball and volleyball players

Abstract Purpose To maximise sporting success, disciplines such as basketball and volleyball need to improve their methods of analysing the sporting performance and fitness of their athletes. Although energy intake quantities have been established at a theoretical level for women to perform at a sporting level, it has been found that these energy intake levels are not met or followed and that, despite this, the performance of female players is not diminished. Thus, the purpose of this research study was to describe and compare the anthropometric characteristics of these two disciplines and to identify the differences in actual and theoretical energy intake, as well as to observe physical performance in both disciplines. Methods Anthropometric data, continuous quantitative data, training time and characteristics, and energy intake data were collected. Performance tests included upper and lower body strength, speed, agility, and endurance tests. Dietary monitoring showed lower intakes of total energy, carbohydrate and protein than theoretically recommended. However, the athletes experienced overall improvements in performance and body composition. Results The mean total energy intake was 20.2 ± 4.3 kcal·kg−1·day−1. The minimum individual mean intake was 9.8 kcal·kg−1·day−1 and the maximum was 25.95 kcal·kg−1·day−1. Carbohydrates accounted for 54.3% ± 8.8% of the energy intake; 20.3% ± 6.5% from fats; 25.4% ± 5.7% from proteins. Conclusions Current data suggest that, although a cause-effect relationship between dietary intake and BC performance cannot be determined, elite athletes in these sports disciplines may experience beneficial outcomes despite having lower total energy, CHO, protein, and fat intakes than previously recommended in the literature.

Prediction on seismic performance levels of reinforced concrete beams by considering crack development

The plastic rotation angle or deflection is typically used as the indicator to evaluate the earthquake-induced damage and classify the seismic performance levels of reinforced concrete (RC) beams. Herein, one of the most important issues is to determine the seismic performance level limits of RC beams. Whereas, different countries provided their specific method to determine the limit values by considering the loading-carrying capacity of RC beams, which could not be used to describe the earthquake-induced seepage of structures, especially for underground structures. Therefore, in this study, the seismic performance level limits of RC beams were predicted by using the machine learning methods and considering the development of cracks. Firstly, the seismic performance level limits of RC beams were presented after discussing the methods in different codes and the development of cracks. Then an earthquake performance test database of RC beams was established after collecting 452 test results of RC beams, and Pearson correlation analysis was conducted for feature selection to determine the input mechanical parameters and dimensional parameters for machine learning. Meanwhile, the correlation between the inputs and limit values was analyzed using the mutual information method. Regression models of seven machine learning methods were then established to predict the performance level limits of RC beams, and the hyperparameters of the machine learning models were optimized with the TPE optimization algorithm and cross-validation. The generalization ability of the prediction models was evaluated and the accuracy of predicted results by different methods was analyzed. Finally, the predicted seismic performance level limits of RC beams could be used to evaluate the earthquake-induced damage of RC beams by combining them with the seismic behavior of RC beams.

Distributed Ledger-Based Authentication and Authorization of IoT Devices in Federated Environments

One of the main security challenges when federating separate Internet of Things (IoT) administrative domains is effective Identity and Access Management, which is required to establish trust and secure communication between federated IoT devices. The primary goal of the work is to develop a “lightweight” protocol to enable authentication and authorization of IoT devices in federated environments and ensure the secure communication of IoT devices. We propose a novel Lightweight Authentication and Authorization Framework for Federated IoT (LAAFFI) which takes advantage of the unique fingerprint of IoT devices based on their configuration and additional hardware modules, such as Physical Unclonable Function, to provide flexible authentication and authorization based on Distributed Ledger technology. Moreover, LAAFFI supports IoT devices with limited computing resources and devices not equipped with secure storage space. We implemented a prototype of LAAFFI and evaluated its performance in the Hyperledger Fabric-based IoT framework. Three main metrics were evaluated: latency, throughput (number of operations or transactions per second), and network resource utilization rate (transmission overhead introduced by the LAAFFI protocol). The performance tests conducted confirmed the high efficiency and suitability of the protocol for federated IoT environments. Also, all LAAFFI components are scalable as confirmed by tests. We formally evaluated LAAFFI security using Verifpal as a formal verification tool. Based on the models developed for Verifpal, we validated their security properties, such as message secrecy, authenticity, and freshness. Our results show that the proposed solution can improve the security of federated IoT environments while providing zero-day interoperability and high scalability. Compared to existing solutions, LAAFFI is more efficient due to the use of symmetric cryptography and algorithms adapted for operations involving IoT devices. LAAFFI supports multiple authorization mechanisms, and since it also offers authentication and accountability, it meets the requirements of Authentication, Authorization and Accounting (AAA). It uses Distributed Ledger (DL) and smart contracts to ensure that the request complies with the policies agreed between the organizations. LAAFFI offers authentication of devices belonging to a single organization and different organizations, with the assurance that the encryption key will be shared with another device only if the appropriate security policy is met. The proposed protocol is particularly useful for ensuring the security of federated IoT environments created ad hoc for special missions, e.g., operations conducted by NATO countries and disaster relief operations Humanitarian Assistance and Disaster Relief (HADR) involving military forces and civilian services, where immediate interoperability is required.

Estimation of random incidence sound transmission loss of panels based on normal incidence sound transmission loss measurements

The performance of building sound insulation is an important parameter for evaluating the quality of construction projects. So far, the sound insulation performance testing of building walls requires the installation of large-dimensioned wall samples in specialized sound insulation laboratories, which is time-consuming and costly. If small-dimensioned components of the wall panels can be applied and quickly tested at the project site, it could significantly improve efficiency and reduce costs. To address this issue, this paper investigates a method for estimating the random incidence sound transmission loss of wall panels based on the measurement of the normal incidence sound transmission loss of corresponding small samples. Initially, the sound transmission loss of single-layer and composite structures is theoretically analyzed based on the theories of Equivalent Single Layer method and Layer-Wise method. Subsequently, the random incidence sound transmission loss is estimated by the normal incidence sound transmission loss. The methodology for estimating the random incidence sound transmission loss of wall panels proposed in this study offers both a practical approach and theoretical support for the rapid assessment of the sound insulation performance of building walls. This study is of great significance for improving the quality of construction projects and inspection efficiency.

Embodying anticipated affect enhances proactive behavior in 5-year-old children

Imagining anticipated affects can foster future-oriented behavior in adults. However, children often still have difficulties in vividly imagining how they will feel in a specific episode (affective episodic future thinking [EFT]). We investigated whether enacting anticipated affects helps children to imagine how they will feel and whether this enhances proactive behavior in turn. A total of 90 5-year-old children were randomly assigned to one of three groups. In the embodiment group, children were instructed to imagine and physically enact how positive and negative they would feel in an upcoming performance test. Children in the EFT-only group underwent a similar procedure but did not enact their future affect. In the control group, children were reminded of the upcoming test only without receiving a prompt to imagine the upcoming test. After the manipulation, children had the opportunity to play one of three games. One game was relevant for the test. Children’s choice to play the relevant game in advance of the test served as an indicator for proactive behavior. Mechanisms (e.g., detailedness of the envisioned event) and moderators (theory of mind and neuroticism) of the link between embodied EFT and proactive behavior were explored. Children in the embodiment group chose the relevant game above chance level, but they did not choose the relevant game more often than children in the EFT-only group and the control group. Those results were independent of the assumed mediators and moderators.

In-vivo left atrial surface motion and strain measurement using novel mesh regularized image block matching method with 4D-CTA

Atrial strain and motion play important roles in evaluation of stroke risks for patients with atrial fibrillation. While cardiac computed tomographic angiography (CTA) provides detailed left atrial morphology with unparallel image resolution, finding a suitable strain measurement method for CTA remains a considerable challenge. In this paper, for the first time, we introduced a mesh regularized image block matching method to estimate 3D left atrial (LA) surface strain with 4D CTA. A series of performance tests with ex-vivo phantom and in-vivo 4D-CTA data were deployed. In conclusion, our proposed method could provide reliable LA motion and strain data within limited time.

Development of Fluorine-Free Electrolytes for Aqueous-Processed Olivine-Type Phosphate Cathodes.

Environmental impacts and resource availability are significant concerns for the future of lithium-ion batteries. This study focuses on developing novel fluorine-free electrolytes compatible with aqueous-processed cobalt-free cathode materials. The new electrolyte contains lithium 1,1,2,3,3-pentacyanopropenide (LiPCP) salt. After screening various organic carbonates, a mixture of 30:70 wt.% ethylene carbonate and dimethyl carbonate was chosen as the solvent. The optimal salt concentration, yielding the highest conductivity of 9.6 mS·cm-1 at 20 °C, was 0.8 mol·kg-1. Vinylene carbonate was selected as a SEI-stabilizing additive, and the electrolyte demonstrated stability up to 4.4 V vs. Li+/Li. LiFePO4 and LiMn0.6Fe0.4PO4 were identified as suitable cobalt-free cathode materials. They were processed using sodium carboxymethyl cellulose as a binder and water as the solvent. Performance testing of various cathode compositions was conducted using cyclic voltammetry and galvanostatic cycling with the LiPCP-based electrolyte and a standard LiPF6-based one. The optimized cathode compositions, with an 87:10:3 ratio of active material to conductive additive to binder, showed good compatibility and performance with the new electrolyte. Aqueous-processed LiFePO4 and LiMn0.6Fe0.4PO4 achieved capacities of 160 mAh·g-1 and 70 mAh·g-1 at C/10 after 40 cycles, respectively. These findings represent the first stage of investigating LiPCP for the development of greener and more sustainable lithium-ion batteries.

Effects of different pre-exercise strategies on jumping performance in female volleyball players.

The present study aimed to compare different pre-exercise strategies on jumping performance in female volleyball players. Fifteen healthy female volleyball players (age=18±0.6 years; training experience = 7.3±1.4 years; height = 164.8±5.4 cm; body mass = 57.2±8.1 kg) volunteered to participate in the study. Three different pre-exercise conditions (5 repetition maximum knee extension, electromyostimulation [EMS] and ischemic preconditioning [IPC]) were applied to the subjects and compared to a control condition performing a standardized warmup. Subjects performed the squat jump and 15 sec repeated countermovement jumps following a rest period. Measures associated with jumping performance were collected and compared between conditions. Rating of perceived exertion was also collected after each performance test. No pre-exercise condition outperformed a standardized warm-up on inducing improvements in jumping performance and in fact, EMS and IPC conditions resulted in performance decrements compared to control (P<0.05). We conclude that a standardized warm-up is enough to induce improvements in jumping performance in female volleyball players. Future research should examine alternative strategies alongside standardized warm-up to determine how best to prepare for jumping and related sport-specific tasks in female volleyball players.

Microstructure and wear resistance of laser cladding AlCoCrFeNiSiB high-entropy alloy with high boron content

In this study, a wear-resistant coating of high boron content Al1.5CoCr2Fe1.5NiSi0.5B2 high-entropy alloy (HEA) was prepared on X65 pipeline steel by laser cladding. The coating underwent microhardness testing, wear performance testing, and analyses including scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD). The results revealed a dual-phase structure of body-centered cube (BCC) and face-entered cube (FCC) in the coating, with the presence of Fe1.1Cr0.9B0.9 phase distributed within the BCC. Utilizing high-resolution transmission electron microscopy (HRTEM) characterization, irregular atomic arrangement regions within the BCC structure were observed. Through the calculation of the α2 and ε parameters of the coating, the degree of lattice distortion in the BCC and FCC phases was quantitatively described. The results suggested that the addition of a substantial amount of boron could strengthen the lattice distortion effect, leading to improved hardness and wear resistance of the coating. The average microhardness of the coating was 912 HV, about 5 times higher than X65 substrate, improved by more than 10 % compared with other AlCoCrFeNi-based high-entropy alloys and B-containing high-entropy alloys. The wear rate was 4.78 × 10−6 mm/N·m, wear performance is nearly 10 times higher than other AlCoCrFeNi HEA without boron, 2 times higher than HEA with born. The wear mechanism of the coating was identified as abrasive and oxidative wear.

Soil nematode community profiling using reference-free mito-metagenomics

Nematodes are ubiquitous and diverse components of soil ecosystems worldwide. The 18S-based metabarcoding is known to have low species-level resolution and introduce bias in PCR. The mito-metagenomics (MMG) approach involves directly sequencing pooled samples, yields numerous mitochondrial reads that can be assembled into full or partial mitogenomes. This method circumvents the challenges associated with PCR-based metabarcoding and hold significant promise in biodiversity and phylogeny study. However, a reference database is typically required to extract mito-reads/contigs and provide taxonomic or phylogenetic context, thereby limiting its applicability. In this study, we introduced a novel reference-free pipeline for MMG assembly and diversity estimation. This pipeline has been integrated into a snakemake workflow, enabling the generation of output that is readily useable for phylogeny reconstruction in a single run. The performance tests have indicated that this new approach surpasses reference-based methods in soil nematode community profiling. We demonstrated that assembly quality improves with increasing sequencing depth, recommending an average of 1–2 Gb per species to achieve acceptable MMG assembly. Our pipeline presents an opportunity to create high-resolution phylogenies and assess diversity for poorly understood taxa, including neglected microscopic eukaryotes.

Tribological properties of graphene oxide reinforced aramid paper-based composites

Self-lubricating paper-based composites can provide technological solutions such as low friction and extended service life for the aerospace airframe kinematic mechanical components. To improve the tribological properties of aramid short fibers, this study chemically combined graphene oxide (GO) with aramid nanofibers (ANF) through intermolecular forces, creating a self-lubricating GO-reinforced aramid paper-based composite GO/ANF. Mechanical performance tests have shown that the introduction of GO can significantly improve the fracture strength, Young's modulus, and toughness of paper-based composites. The frictional performance test results show that compared with ANF, the GO/ANF paper-based composites can maintain the lowest coefficient of friction (COF) and wear under high load and high sliding rate conditions. When the amount of GO added is 1 wt%, the COF and volume wear rate of GO/ANF paper-based composites are reduced by 23 % and 89 %, respectively. Mechanism analysis indicates that synergistic effects and friction transfer films are important factors contributing to the excellent performance of paper-based composites. This GO/ANF paper-based composite has good application prospects as a good anti-wear liner material in self-lubricating sliding bearing.

Design and Performance Test of an Implementable Rectenna Encapsulated in a Human Tissue Bio-Case Model

Design and Performance Test of an Implementable Rectenna Encapsulated in a Human Tissue Bio-Case Model

B-254 Analytical and Clinical Performance Evaluation of Plasma pTau217 in a Clinical Diagnostic Laboratory

Abstract Background Blood-based biomarkers provide an accessible and cost-effective tool for diagnosing Alzheimer’s disease (AD). Among these biomarkers, phosphorylated tau 217 (pTau217) shows promise for both AD diagnosis and differential diagnosis, as well as for facilitating access to emerging disease-modifying therapies. The ALZpath SIMOA pTau-217 v2 assay is a digital immunoassay designed for quantifying pTau-217 in human EDTA plasma samples. This study assesses the analytical performance of plasma pTau217 assays as a Laboratory Developed Test (LDT) appropriate for diagnostic application. Methods In this analytical study, we evaluate accuracy, precision, detection limits, linearity, and analyte stability. Plasma pTau217 levels were measured using the ALZpath pTau217 v2 assay on a single Quanterix HD-X SIMOA Analyzer platform at BC Neuroimmunology Lab. Inc. Vancouver, British Columbia, Canada. As a clinical testing laboratory, our validation procedures are in accordance with CAP and CLIA requirements, with a primary focus on adhering to CLSI guidelines for both analytical and clinical performance testing. To determine a reference range and cut-off, samples of Amyloid PET-confirmed cases (n=263) and healthy subjects between the ages of 55 and 95, with a roughly equal ratio of males to females (n=219), were tested. Results The ALZpath pTau217 assay demonstrates an analytical measurement range of 0.0046 - 3.4056 ng/L, with a limit of blank (LoB) of 0.0019 ng/L, a limit of detection (LoD) of 0.0046 ng/L, and a limit of quantification (LoQ) of 0.03 ng/L. Linearity spans from 0.06 to 1.75 ng/L, with repeatability showing intra-laboratory precision above LoQ ≤ 20% CV. Stability is maintained at 4⁰C for ≤ 1 week, at room temperature for ≤ 72 hrs, at -20⁰C for ≤ 2 weeks, and at -70⁰C for ≤ 3 weeks, with freeze/thaw cycles tolerated up to 6 times. Moreover, interference is not detected at the maximum concentrations tested for albumin, unconjugated bilirubin, biotin, hemoglobin, creatinine, and heterophilic antibodies. The reference range was determined using the 95% reference interval, resulting in 0.398 ng/L. ROC analysis yielded an AUC of 0.932 with a Youden index of 0.338 ng/L. At the Youden index, sensitivity was 90.0% with a specificity of 85.6%. Specificity reached 95.5% at the upper cut point of 0.471 ng/L, while sensitivity was 94.8% at the lower cut point of 0.242 ng/L. Conclusions The outstanding analytical performance of pTau217 supports its adoption as a reliable screening and diagnostic tool in clinical practice, aiding clinicians in the accurate diagnosis of AD.

Design and Experiment of Compound Transplanter for Sweet Potato Seedling Belt

To address the issues of high labor intensity, excessive manpower requirements, low planting spacing qualification rates, low planting depth qualification rates, and low operational efficiency associated with sweet potato transplanting, a sweet potato seedling belt transplanter has been designed. This machine can perform multiple processes: precision tillage and ridge shaping, orderly seedling feeding from rolls, the efficient separation of seedlings from the belt, flexible gripping and shaping, precise soil covering and the mechanism of exposing seedling tips. A three-factor, three-level orthogonal test was carried out using the forward speed of the machine, the pitch of the screw belt and the rotational speed of the screw as the influencing factors of the performance test, and the qualified rate of planting spacing and the qualified rate of planting depth as the evaluation indexes. The test results indicated that the significance order of the factors affecting the qualification rate for planting spacing with the optimal combination of factors was as follows: a forward speed of 0.3 m·s−1, a ribbon spacing of 60 mm, and a screw speed of 160 rpm. Field trials confirmed that under optimal conditions, the average qualification rate for planting spacing was 90.37%, meeting relevant technical standards and agronomic requirements.