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Abstract Testicular adrenal rest tumor (TART) is a prevalent complication associated with congenital adrenal hyperplasia (CAH), culminating in gonadal dysfunction and infertility. Early hormonal intervention is preventive, but excessive glucocorticoid poses risks. Developing reliable methods for early TART diagnosis and monitoring is crucial. The present study aims to formulate a scoring system to identify high-risk infertility through analysis of TART ultrasound features. Grayscale and power Doppler ultrasound were employed in this retrospective study to evaluate testicular lesions in male CAH patients. Lesion assessment encompassed parameters such as range, echogenicity, and blood flow, and these were subsequently correlated with semen parameters. Results of 49 semen analyzes from 35 patients demonstrated a notable inverse correlation between lesion scores and both sperm concentration (rs = − 0.83, P

Lymphatic metastasis is the main cause of early-stage tumor spread, making the identification and therapy of metastatic sentinel lymph nodes (SLNs) are highly desirable in clinic. Currently, suspected malignant SLNs typically undergo a series of independent operations in clinical practice, including imaging, staining, sentinel lymph node biopsy (SLNB) and lymph node dissection (LND), which brings inconvenience to diagnosis and treatment, and may cause postoperative complications for patients. Moreover, the ordinary removal of tumor-draining lymph nodes (TDLNs) may do harm to systemic immunity required for tumor eradication. Hence, we utilized the hybrid nanosystem (SPIOs + RPPs) we constructed before for the integrated staining, ultrasound imaging, and therapy of metastatic SLNs. In this study, SPIOs + RPPs could migrate into SLNs successfully to stain them black for easy visual identification. Beyond staining, the hybrid nanosystem could realize contrast enhanced ultrasound (CEUS) imaging in SLNs. Meanwhile, it could inhibit cancer cells to lower the tumor burden and reverse immune-suppressive microenvironment of metastatic SLNs effectively via magnetic hyperthermia immunotherapy in VX2 tumor-bearing rabbits with popliteal fossa lymph node metastasis. These findings indicate that SPIOs + RPPs is a potential multifunctional theranostic agent for detection and therapy of lymphatic metastasis.

The use of High Strength Concrete Filled Steel Tube (HSCFST) members has become widespread, but there is limited research on their creep behavior. This study examines the creep and shrinkage characteristics of HSCFST columns subjected to axial loading by testing fifteen specimens with various steel ratios over a period of 365 days. The experimental data is then compared to the predictions made by the creep prediction models MC 90, ACI 209, and AFREM. The results indicate that the creep coefficients of HSCFST specimens are significantly lower than those of plain concrete specimens. By the end of 365 days, the creep coefficient of plain concrete is more than twice that of concrete in HSCFST. The steel ratio has a slight effect on the creep of CFST specimens, with the creep coefficient decreasing as the steel ratio increases. The comparison of the results shows that the MC 90 and ACI 209 models overestimate the creep of concrete, while the AFREM model underestimates it. Furthermore, the ACI 209 model is modified based on the experimental results by applying a correction factor of concrete strength, which significantly improves its accuracy and makes it suitable for predicting the creep of high strength plain concrete and HSCFST.

Abstract Testicular microcirculation is closely related to spermatogenic function and seminiferous tubular function. The diagnosis and monitoring of testicular diseases can be associated with testicular microcirculation; however, there are currently no effective non‐invasive methods for super‐resolution imaging of testicular microcirculation. In this study, we introduced state‐of‐the‐art graph‐based tracking with the Kalman motion model algorithm to non‐invasively image human testicular microcirculation for the first time with a regular frame‐rate clinical ultrasound imaging system (37 Hz). Two distinct testicular vessels with an 81 µm separation were resolved in the testicular vasculature, surpassing all other imaging modalities. In a retrospective study, we performed contrast‐enhanced ultrasound examinations(CEUS) and ultrasound localization microscopy (ULM) processing on the included 76 infertile patients and 15 healthy controls from August 2021 to May 2023 and obtained super‐resolution images of testicular microcirculation with sub‐diffraction resolution. Through the results of one‐way analysis of variance tests and receiver operating characteristic analyses, we found that the ULM‐based parameters hold promise as clinical guidance for differentiating between non‐obstructive and obstructive male infertility. The mean vessel diameter achieved an area under the curve (AUC) of 0.920 (95% confidence interval [CI]: 0.847–0.994, p

To understand the role of paddy soils in the global carbon cycle, it is necessary to analyze the characteristics of the organic carbon pool at different soil depths. It was hypothesized that soil organic carbon fractions including labile organic carbon fraction I (LOCF-I), labile organic carbon fraction II (LOCF-II), and recalcitrant organic carbon (ROC) distributed differently within the soil profile. In this study, soil was collected from 27 typical rice fields in Guangdong Province, south China. The carbon fractions of the paddy field soils were analyzed and compared over a 0–60 cm depth profile. The relationship between carbon content and the physical and chemical properties of the soils was further analyzed using correlation analysis and structural equation modeling. The results showed that soil total organic carbon concentration in paddy fields was increased by 22.1% during the last four decades. In the soil organic carbon pool of 0–60 cm profile, the proportion of 67.31 to 70.31% in ROC, 21.75 to 22.06% in LOCF-I, and 7.7 to 10.63% was recorded, respectively, indicating that ROC was the dominating fraction. Storage of soil total organic carbon and fractions all decreased with the increase in soil depth. Correlation and path analysis showed that total nitrogen was the main driving factor affecting the soil carbon fractions, whereas pH and soil bulk density indirectly affected the content of carbon fractions by influencing total nitrogen. The results imply the importance of soil total nitrogen in paddy carbon management of rice cultivation.

BackgroundThe issue of low physical activity (PA) levels among the youth is a longstanding concern. Smartphone applications offer a promising avenue for delivering interventions that are both accessible and engaging. Up to now, there appears to be a gap in the literature, with no systematic reviews assessing the efficacy of smartphone apps in encouraging increased physical activity among healthy young adults.ObjectiveTo synthesize the effects of a smartphone app-based intervention on PA and PA-related psychological correlates in healthy young adults (18-35 years old).MethodsA search was conducted on eighteen databases: PubMed, Medline, Web of Science, SPORTDiscus, Scopus, Academic Search Premier, Communication and Mass Media Complete, Article First, Biomed Central, BioOne, EBSCOHost, JSTOR, ProQuest, SAGE Reference Online, ScienceDirect, SpringerLink, Taylor&Francis, and Wiley Online. The search covered the period up until December 2023. This research included all randomized controlled trials (RCTs) that evaluated the effectiveness of smartphone app-based interventions on PA and PA related psychological outcomes in healthy young adults. The overall impact was determined by vote counting based on the direction of effect and aggregating p values. The quality of the evidence was evaluated using an 8-item scale. This study has been registered in the PROSPERO database with the identification number CRD42023390033.ResultsA total of 8403 articles were retrieved, and based on the predefined inclusion and exclusion criteria, seven articles were selected for inclusion. Among these articles, four high-quality RCTs were identified, and the results of vote counting and combining p values methods suggested that smartphone-based app interventions did not demonstrate significant effectiveness in improving PA and PA-related psychological outcomes. However, some improvements were observed. The analysis results, which were categorized into fitness apps and health apps based on the characteristics of the interventions, also failed to demonstrate significant intervention effects.ConclusionThe findings indicate that, currently, there are no significant effects of smartphone app interventions on improving PA and PA-related psychological outcomes in healthy young adults aged 18-35 years. It is important to note that these findings should be interpreted with caution due to the limited number of included studies. Future research should focus on employing high-quality study designs to determine the true effects of interventions and analyze various smartphone app interventions. These analyses should encompass different app characteristics (e.g., fitness app and health app), various combinations (e.g., fitness app alone and fitness app in combination with other interventions), diverse intervention goals (e.g., PA and PA along with other outcomes), and multiple intervention characteristics (e.g., frequency and duration).

【Objective】Taking the lower reaches of Danshui River, a major regulated river in Guangdong Province, as the research object, the temporal and spatial dynamic changes of pollutants in its main tributaries were investigated.【Method】Through the method of remote sensing image interpretation combined with field investigation, monitoring points were arranged for different land use function areas in tributary basins of the lower reaches of the Danshui River in Guangdong Province, and monthly field monitoring of water quality in cross sections was carried out. Single factor evaluation method, comprehensive pollution index method and anomaly coefficient method were used to evaluate and analyze the spatio-temporal variation characteristics of water quality.【Result】In the main tributaries of the lower reaches of the Danshui River, except for Maxi River, the monitoring indexes of the catchment sections of other tributaries were significantly higher than those of the source water quality, and TN was the main pollution factor. During the study period, the NH4+-N compliance rate increased from 69.70% to 79.17%, and the COD compliance rate increased from 68.94% to 70.08%.In terms of annual variation, the fluctuation of the comprehensive pollution index of the Maxi River was the most stable, and the fluctuation of the Dali River was more severe, which was obviously higher in January, April, November and December compared with other months. The contribution rate of NH4+-N in the Dali River accounted for 15%-37%, and the TN was an important water pollutant in the Dali River. The TN pollution index in dry period was significantly higher than that in wet period, however, the TP pollution index was slightly lower than that in wet period. In general, the comprehensive pollution index of each tributary in the dry period was higher than that in the wet period. Spatially, the water quality of the west bank tributaries of the Danshui River was better than that of the east bank. Industrial zone, urban living area and rural residential area had a great impact on the TN, NH4+-N and TP flowing through the river section, respectively.【Conclusion】In the lower reaches of the Danshui River, the water quality of the Maxi River on the west bank is generally better, while that of the Dakeng River, the Shatian River and the Dali River on the east bank is relatively poor. The pollution indexes of various tributaries have no obvious change rules during the year, and the pollution indexes of the river reaches near industrial, urban and rural residential areas are higher than those of other river reaches.

The large-amplitude fluctuations of ultrasound in high-energy ultrasonic stress relieving cause the crystal grains or lattices in the high residual stress zone to vibrate or creep alternately. This triggers secondary effects such as ultrasonic softening and dislocation movement. The sound field also produces periodic shock waves or intermittent shock waves, which form local pressure gradients at the wave front. These pressure gradients cause local heating of the grain boundary, accelerating material softening and promoting slip between grains, ultimately resulting in residual stress elimination. This technique was applied to detect the welding residual stress of the upper chord of the main truss of Sanguantang Bridge by using an ultrasonic stress meter. After the measurement, it was found that the welding residual stress in some areas was too large, and the welding residual stress needed to be eliminated. The welding seam was re-inspected after the residual stress relief operation was completed. The test results showed a maximum reduction rate of 63.91% and an average overall reduction rate ranging from 24.52% to 37.23%. The reduction effect is more significant in areas with higher welding residual stress.

This paper mainly explores the distribution of welding residual stress of U-rib stiffened plates of steel box girders and examines the influence of welding residual stress over the natural frequencies of these plates. The research focuses on two aspects, namely, the distribution of welding residual stress, and the dynamic behavior of U-rib stiffened plates in the context of that distribution. Firstly, we build two finite element models to analyses the welding process and study the dynamic behavior. Next, the authors discussed how different geometric parameters, as well as welding parameters, affect the residual stress distribution. In addition, the welding residual stress curves were fitted for steel box girders of varied sizes, and a simplified formula was deduced for the distribution of welding residual stress. After that, the simplified formula was applied to analyze the natural frequencies of stiffened plates in multiple sets of models. Through the analysis of natural frequency under different boundary conditions, it was learned that the welding residual stress has a remarkable influence on the natural frequencies of stiffened plates.

Great advances have been made with the lattice Boltzmann (LB) method for complicated fluid phenomena and fundamental thermal processes over the past three decades. This paper presents a systematic overview of the LB method from 1990 to 2018, based on bibliometric analysis and the Science Citation Index Expanded (SCI-E) database. The results show that China took the leading position in this field, followed by the USA and UK. The Chinese Academy of Sciences had the most publications, while the Los Alamos National Laboratory was first as far as highest average citation per paper and h-index are concerned. Physical Review E was the most productive journal and “Mechanics” was the most frequently used subject category. Keyword analysis indicated that recent research has focused on the natural convection and heat transfer of nanofluid or multiphase flow in complex porous media. Hydrothermal treatment of nanofluid with shape factor on the conditions, such as variable magnetic fields, thermal radiation and slipping boundary, were the research hotspots. Further research perspectives mainly explore the multiscale models for coupling multiple transport phenomena, morphology optimization of porous parameters, new nanoparticles with shape factor, multicomponent LB method considering Knudsen diffusion effect, LB-based hybrid methods, radiation performance or boiling-heat transfer of nanofluid, and the active control of droplets, may continue to attract more attention. Moreover, some new applications, such as phase change of metal foam, erosion induced by nanaofluid, anode circulating, 3D modeling in thermal systems with vibration, and magnetohydrodynamics microfluid devices, could be of interest going forward.

Phosphorus (P) is an essential element for crop production and a key source of nonpoint pollution in agroecosystems. In this study, we sought to analyze P levels and the factors affecting soil P availability, via P adsorption, in a typical field system that is characterized by the year-round cultivation of vegetables. A total of 190 sites were sampled from vegetable fields in Guangdong Province, South China. Within the research area, average concentrations of 124.49 mg P kg-1 and 1.55 g P kg-1 were recorded for available P (AP) and total P (TP), respectively, which are 8.53- and 1.78-fold higher, respectively, than the corresponding values recorded in 1980. The determined P adsorption maximum (Qm) averaged at 488.38 mg kg-1, which represents a reduction of 16% compared to the values obtained four decades ago. Accumulations of both TP and AP were found to be negatively correlated with the soil’s maximum adsorption buffering capacity (MBC), although no significant correlations with the soil binding energies (k) and Qm, were seen. However, soil pH was found to be significantly correlated with k and Qm. Furthermore, both free Mn oxides (Mnd) and silt concentrations in the soil were found to contribute to explaining the variations in Qm. Collectively, the findings of this study provide evidence to indicate that there has been an excessive accumulation of P in the perennial vegetable fields of Guangdong Province over the past four decades, which may have had negative effects on the P supply potential of the soil by reducing the maximum adsorption buffering capacity.

Deflection is a crucial indicator to reflect the operating condition of girder bridges, which can be used to evaluate structure condition and identify abnormal loading. The paper analyzed the deflection characteristics of long-span girder bridges based on the coupling vibration between stochastic traffic stream and bridge. First, the latest research advances were integrated to form an analytical model of the coupling vibration between stochastic traffic stream and bridge. Then, a generalized Pareto distribution model based on peaks-over-threshold theory was established to predict the extreme girder deflection. Next, a cellular automaton based microsimulation method was proposed to model the traffic loads on bridges, which utilized the intelligent driver car-following model and acceptance distance based lane-changing model. Finally, these theories were applied in the case study of a long-span prestressed concrete continuous girder bridge. It is discovered from the study that, under the coupling vibration between stochastic traffic stream and bridge, the predicted extreme deflection of the case bridge is far lower than the specified design value. Hence, a grading warning model was established and employed to the analysis of deflection monitoring data of the bridge, showing a wide potential prospect of application.

While the effects of carbon on soil nitrogen (N) cycle have been extensively studied, it is not clearly understood how co-existing macronutrients, such as phosphorus (P), affect the N cycle in agroecosystems. In this study, P amendment effects on nitrification in a fertile agricultural soil were investigated under a typical N-P amendment rate. In a laboratory incubation study, soils were amended with urea, monopotassium phosphate and a mixture of urea and monopotassium phosphate at the same rate. In soils that received no amendments (control), P only, urea only, and urea plus P amendment, nitrification occurred within the first five days, with an average net nitrification rate of 5.30, 5.77, 16.66 and 9.00 mg N kg−1d−1, respectively. Interestingly, nitrification in urea-treated soils was retarded by P addition where a N:P ratio seemed to be a key factor impeding nitrification. This was also supported by the response of ammonia-oxidizing bacteria (AOB), which was more sensitive to P addition than ammonia-oxidizing archaea (AOA). The outcome of this study showed that application of P fertilizer suppressed the nitrification process in urea amended soil, suggesting that a synergistic aspect of N and P nutrient management should be further explored to retard N losses from agricultural systems.

Escherichia coli O157:H7 is one of the leading bacterial pathogens causing foodborne illness. In this study, an impedance immunosensor based on the use of magnetic nanobeads and screen-printed interdigitated electrodes was developed for the rapid detection of E. coli O157:H7. Magnetic nanobeads coated with anti-E. coli antibody were mixed with an E. coli sample and used to isolate and concentrate the bacterial cells. The sample was suspended in redox probe solution and placed onto a screen-printed interdigitated electrode. A magnetic field was applied to concentrate the cells on the surface of the electrode and the impedance was measured. The impedance immunosensor could detect E. coli O157:H7 at a concentration of 104.45 cfu·mL−1 (~1400 bacterial cells in the applied volume of 25 μL) in less than 1 h without pre-enrichment. A linear relationship between bacteria concentration and impedance value was obtained between 104 cfu·mL−1 and 107 cfu·mL−1. Though impedance measurement was carried out in the presence of a redox probe, analysis of the equivalent circuit model showed that the impedance change was primarily due to two elements: Double layer capacitance and resistance due to electrode surface roughness. The magnetic field and impedance were simulated using COMSOL Multiphysics software.

Basic oxygen furnace (BOF) steelmaking is widely used in the metallurgy field. The slagging reaction is a necessary process that oxidizes C, Mn, Si, P, S, and other impurities and therefore directly affects the quality of the resultant steel. Relevant research has suggested that intensifying the stirring effect can accelerate the slagging reaction and that the dynamic characteristics of the top blow are the key factor in exploring the related complex physical and chemical phenomena. To address the issue, the standard k-ω turbulence model and level-set method were adopted in the present work and a fluid dynamics model was developed for a BOF. Accordingly, the slag–metal–gas emulsion interaction and stirring effect were investigated, and the interference mechanism of a multi-nozzle supersonic coherent jet was revealed. Finally, a self-adjustment method based on fuzzy control is proposed for the oxygen lance. The results indicate that the transfer efficiency of jet kinetic energy at the gas–liquid interface is the critical factor for the slagging reaction and that multi-nozzle oxygen lances with a certain twisted angle have important advantages with respect to stirring effects and splashing inhibition. The fuzzy control method predicts that the optimal nozzle twist angle is within the range of 7.2° to 7.8°. The results presented herein can provide theoretical support and beneficial reference information for BOF steelmaking.

Active magnetic bearings (AMBs) commonly use pulse-width modulation to reduce analogous hardware and manufacturing costs, but they experience sensing process, sensing accuracy and stability problems. To address these issues, a synchronous sampling-based direct current estimation (SS-DCE) method is proposed herein with a bistate switching power amplifier. First—considering the reluctance evolution mechanism of AMBs—a coupling relation mathematical model between rotor displacement and voltage/current is presented to acquire the rotor position from the working coil current alone. Then—assuming that the switching current was an approximately triangular signal—a DCE for the rotor position was established based on the estimation inductance of the charging/discharging phase. Finally—to decrease the phase shift caused by the self-sensing filters and position estimation algorithms—the SS-DCE method was introduced to conduct precise position detection for rotors with high velocities. The simulation and experimental results indicated that the proposed method could improve the sensing accuracy and stability. Compared to other AMB position estimation methods, the simple linearity of the SS-DCE method was greatly improved and could be controlled below 4%. Evaluation using frequency response analysis showed that the SS-DCE method had excellent dynamic accuracy and could perform at a higher phase margin, especially for the uprising/landing transient state. Moreover, there was a phase margin of 158° at the natural frequency of 19.26 HZ, and the peak sensitivity in the 50–250 μm range reached 10.7 dB.

Numerical simulation is an important method used in studying the evolution mechanisms of lake water quality. At the same time, lake water quality inversion technology using the characteristics of spatial optical continuity data from remote sensing satellites is constantly improving. It is, however, a research hotspot to combine the spatial and temporal advantages of both methods, in order to develop accurate simulation and prediction technology for lake water quality. This paper takes Donghu Lake in Wuhan as its research area. The spatial data from remote sensing and water quality monitoring information was used to construct a multi-source nonlinear regression fitting model (genetic algorithm (GA)-back propagation (BP) model) to invert the water quality of the lake. Based on the meteorological and hydrological data, as well as basic water quality data, a hydrodynamic model was established by using the MIKE21 model to simulate the evolution rules of water quality in Donghu Lake. Combining the advantages of the two, the best inversion results were used to provide a data supplement for optimization of the water quality simulation process, improving the accuracy and quality of the simulation. The statistical results were compared with water quality simulation results based on the data measured. The results show that the water quality simulation of chlorophyll a and nitrate nitrogen mean square errors fell to 17% and 24%, from 19% and 31% respectively, after optimization using remote sensing spatial information. The model precision was thus improved, and this is consistent with the actual pollution situation of Donghu Lake.

In the bridge engineering, there are some problems about the dynamics that traditional theory cannot solve. So, the theory about stress waves is introduced to solve the related problems. This is a new attempt that the mechanic theory is applied to practical engineering. The stress wave at a junction of the structure composed of beams and strings is investigated in this paper. The structure is studied because the existence of a soft rope makes the transmission of the force in the bridge structure different from the traditional theory, and it is the basis for further research. The equilibrium equations of the displacement and the internal force are built based on the hypothesis. The fast Fourier transform (FFT) numerical algorithm is used to express an incident pulse of arbitrary shape. The analytical solutions are substantiated by comparing with the finite element programs. The conclusion that if the cross section of the string is relatively small, then the energy density of the structure is relatively large, which is disadvantageous to the structure, can be obtained from this paper.

In this research a DNA aptamer, which was selected through SELEX (systematic evolution of ligands by exponential enrichment) to be specific against the H5N1 subtype of the avian influenza virus (AIV), was used as an alternative reagent to monoclonal antibodies in an impedance biosensor utilizing a microfluidics flow cell and an interdigitated microelectrode for the specific detection of H5N1 AIV. The gold surface of the interdigitated microelectrode embedded in a microfluidics flow cell was modified using streptavidin. The biotinylated aptamer against H5N1 was then immobilized on the electrode surface using biotin–streptavidin binding. The target virus was captured on the microelectrode surface, causing an increase in impedance magnitude. The aptasensor had a detection time of 30 min with a detection limit of 0.0128 hemagglutinin units (HAU). Scanning electron microscopy confirmed the binding of the target virus onto the electrode surface. The DNA aptamer was specific to H5N1 and had no cross-reaction to other subtypes of AIV (e.g., H1N1, H2N2, H7N2). The newly developed aptasensor offers a portable, rapid, low-cost alternative to current methods with the same sensitivity and specificity.

Rapid and specific detection of avian influenza virus (AIV) is urgently needed due to the concerns over the potential outbreaks of highly pathogenic H5N1 influenza in animals and humans. Aptamers are artificial oligonucleic acids that can bind specific target molecules, and show comparable affinity for target viruses and better thermal stability than monoclonal antibodies. The objective of this research was to use a DNA-aptamer as the specific recognition element in a portable Surface Plasmon Resonance (SPR) biosensor for rapid detection of AIV H5N1 in poultry swab samples. A SPR biosensor was fabricated using selected aptamers that were biotinylated and then immobilized on the sensor gold surface coated with streptavidin via streptavidin-biotin binding. The immobilized aptamers captured AIV H5N1 in a sample solution, which caused an increase in the refraction index (RI). After optimizing the streptavidin and aptamer parameters, the results showed that the RI value was linearly related (R2 = 0.99) to the concentration of AIV in the range of 0.128 to 1.28 HAU. Negligible signal ( < 4% of H5N1) was observed from six non-target AIV subtypes. The AIV H5N1 in poultry swab samples with concentrations of 0.128 to 12.8 HAU could be detected using this aptasensor in 1.5 h.

HIFU has been shown to be a more suitable alternative for the treatment of primary solid tumors and metastatic diseases than other focal heat ablation techniques due to its noninvasive and extracorporeal nature. However, similar to other focal heat ablation techniques, HIFU is still in need of refinements due to tumor recurrence.In this work, we investigated the effectiveness of an adjunct treatment regimen using doxorubicin (DOX)-loaded, injectable, in situ-forming, and phase-inverting PLGA as the second line of defense after HIFU ablation to destroy detrimental residual tumors and to prevent tumor recurrence. All of the statistical analyses were performed using the Statistical Package for the Social Sciences 18.0 (SPSS, Inc., Chicago, IL, USA), and p

Salmonella Typhimurium is one of the most dangerous foodborne pathogens and poses a significant threat to human health. The objective of this study was to develop a portable impedance immunosensing system for rapid and sensitive detection of S. Typhimurium in poultry. The developed portable impedance immunosensing system consisted of a gold interdigitated array microelectrode (IDAM), a signal acquisitive interface and a laptop computer with LabVIEW software. The IDAM was first functionalized with 16-Mercaptohexadecanoic acid, and streptavidin was immobilized onto the electrode surface through covalent bonding. Then, biotin-labelled S. Typhimurium-antibody was immobilized onto the IDAM surface. Samples were dropped on the surface of the IDAM and the S. Typhimurium cells in the samples were captured by the antibody on the IDAM. This resulted in impedance changes that were measured and displayed with the LabVIEW software. An equivalent circuit of the immunosensor demonstrated that the largest change in impedance was due to the electron-transfer resistance. The equivalent circuit showed an increase of 35% for the electron-transfer resistance value compared to the negative control. The calibration result indicated that the portable impedance immunosensing system could be used to measure the standard impedance elements, and it had a maximum error of measurement of approximately 13%. For pure culture detection, the system had a linear relationship between the impedance change and the logarithmic value of S. Typhimurium cells ranging from 76 to 7.6 × 106 CFU (colony-forming unit) (50 μL)−1. The immunosensor also had a correlation coefficient of 0.98, and a high specificity for detection of S. Typhimurium cells with a limit of detection (LOD) of 102 CFU (50 μL)−1. The detection time from the moment a sample was introduced to the display of the results was 1 h. To conclude, the portable impedance immunosensing system for detection of S. Typhimurium achieved an LOD that is comparable with commercial electrochemical impedance instruments. The developed impedance immunosensor has advantages in portability, low cost, rapid detection and label-free features showing a great potential for in-field detection of foodborne pathogens.

Over the past decade, the development of high-speed railways in China has gained worldwide attention. With the speeding up of the running train, the coupling vibration of the train-bridge system is aggravated, especially for railways built in a soft soil environment. In this paper, the dynamic features of the train-bridge system when considering and failing to consider pilesoil interaction are investigated, i.e., the "train-bridge-pier-pile-soil" (TBPPS) and "train-bridge-pier" (TBP) models. The study is based on a practical high-speed railway project in Hainan Province, where a 32 m span simply-supported box girder bridge with a four-shaft locomotive using two-system suspension model is studied. Results indicate that the natural frequency of the bridge is obviously reduced when the pile-soil interaction is considered, and the vertical vibration frequency of the bridge girder is increased from 4.87 Hz to 5.46 Hz. Moreover, the resonance speed is 500 km/h both for TBP and TBPPS. The results of bridge dynamic load factors, wheel load reduction rates, and train vibration acceleration are significantly different for TBP and TBPPS, and it is not safe if the pile-soil interaction is not considered. Therefore, it is recommended that the pile-soil interaction is extremely important for the train-bridge system when evaluating the safety and smoothness of train running. If the pile-soil interaction is not involved, the derivation will be significantly large. [ABSTRACT FROM AUTHOR]

The main focus of target tracking is robustness and efficiency. Because of challenges such as background clutter, occlusion, and rotation, high robustness and efficiency cannot be achieved simultaneously. A tracking framework of perceptual correlation filter is improved to achieve high-speed computation between real-time trackers. The main contribution to high-speed computing speed comes from improved depth feature compression, which is realized by combining content-aware features with multiple automatic encoders. In the pre-training stage, an automatic encoder is trained for each class separately. In order to obtain the feature map suitable for target tracking, the orthogonal loss function is added to the training stage and the fine-tuning self-encoder stage. Experiments show that the improved algorithm demonstrates great improvement in accuracy and speed. [ABSTRACT FROM AUTHOR]

Campylobacter jejuni is one of the leading causes of foodborne human gastrointestinal diseases. Poultry and poultry products have been identified as the major transmission routes to humans for this pathogenic bacterium. The objective of this research was to develop a rapid and sensitive immunosensor for detection of C. jejuni in poultry products on the basis of a quartz crystal microbalance (QCM) using magnetic nanobeads (MNBs) for separation of target pathogen and gold nanoparticles for amplification of the measurement. A QCM sensor in a flow cell was prepared by immobilizing the mouse anti–C. jejuni monoclonal antibody (mAb1) on the sensor surface to specifically capture C. jejuni. Rabbit anti–C. jejuni polyclonal antibody (pAb1) was conjugated with MNBs to capture and separate C. jejuni from food matrices. MNB–pAb1–C. jejuni complexes were injected into the flow cell to bind with the mAb1 immobilized on the QCM sensor surface. Goat anti-rabbit immunoglobulin G polyclonal antibody conjugated with gold nanoparticles was injected into the flow cell to bind with pAb1 on MNBs. Finally, resonant frequency was measured with a QCM analyzer, and the change in resonant frequency was correlated to the cell number of C. jejuni. The specificity of this immunosensor was confirmed with different strains of Campylobacter, Salmonella, and other foodborne pathogens commonly colonized in the broiler gastrointestinal tract. Samples of broiler carcass wash and ground turkey were spiked with C. jejuni at different concentrations for use in tests. Results showed that the QCM immunosensor could rapidly detect C. jejuni in poultry products, with a detection limit of 20 to 30 CFU/mL without preenrichment, and a total detection time of less than 30 min. Characteristics of C. jejuni captured by the antibody immobilized on the surface of the QCM sensor were visualized by using atomic force microscopy. This highly adaptive and flexible method could provide the poultry industry a more rapid, sensitive, and effective method for detection of major foodborne pathogens in poultry products. [ABSTRACT FROM AUTHOR]

This paper shows a more exact and practical finite element model of the steel girder deck pavement. Based on Mindlin thick plate theory, a 12-node solid thick plate element was constituted to analyze the pavement. The computation result was compared with that by traditional 4-node and 8-node thick plate finite element, and is satisfactory. A combined plate beam element method is presented to investigate the stiffened plate. A 6-node solid thin plate element was constituted to analyze the top plate based on Kirchhoff thin plate theory. The stiffeners acting as the vertical supporting function mainly are taken as Euler beam elements. A method of using the linear interpolation to realize the longitudinal displacement and the cubic Hermite interpolation to the vertical displacement is presented to analyze the stiffeners. In addition, it is essential to consider the displacement coordination between the top plate and stiffeners. A node-to-node contact scheme, which is applicable for three-dimensional contact analyses involving large deformations, was used to treat the contact problem between pavement and stiffened plate by Lagrange multiplier methods. [ABSTRACT FROM AUTHOR]

In order to detect the multiple avian influenza viruses (AIVs) rapidly, specifically and sensitively, a LabVIEW and microelectrode array-based impedance biosensor was developed and demonstrated. A laptop with LabVIEW software was used to generate excitation signals at different frequencies with an audio card and measure the impedance of target viruses through a data acquisition card. The audio card of the laptop was used as a function generator, while a data acquisition card was used for data communication. A virtual instrument was programmed with LabVIEW to provide a platform for impedance measurement, data processing, and control. Six interdigitated microelectrodes were placed at the bottom of six wells on a microplate to form six sensors for different AIVs and controls. Then, AIV specific ligands were immobilized on the microelectrode surface to capture target viruses. To enhance the sensitivity, AIV specific aptamers conjugated gold nanoparticles and thiocyanuric acid were employed to form a network structure and used as an amplifier. Results of the measured impedance were compared with a commercial IM6 impedance analyzer, and the error was less than 5%. The developed biosensor was portable with the sensitivity and specificity for applications to on-site or in-field rapid screening of avian influenza viruses. [ABSTRACT FROM AUTHOR]

A fast algorithm for determining the installation force of parallel strand cables is proposed in this paper. Because cable-stayed bridges are flexible structures, the algorithm must consider the sag effect of cable stays as well as the prestressing loss caused by displacements of the deck and the pylon when erecting stay cables with a strand-by-strand method. Based on the principle of the isotension method for parallel strand cables, two basic problems involved in the stretching process and the corresponding numerical computing method are fully demonstrated in this paper. To consider the nonlinearity of cables, catenary theory is used for determining the cable shape and cable forces during the entire loading process. According to said method, a corresponding calculation program was compiled, followed by an additional error analysis. Case studies are provided to compare the results calculated by the program with data measured from an ongoing road-rail cable-stayed bridge and from other calculation methods. The results confirm that this computing method can ensure both efficiency and accuracy and is equally applicable to the problem of cable replacement. [ABSTRACT FROM AUTHOR]

In this research a DNA aptamer, which was selected through SELEX (systematic evolution of ligands by exponential enrichment) to be specific against the H5N1 subtype of the avian influenza virus (AIV), was used as an alternative reagent to monoclonal antibodies in an impedance biosensor utilizing a microfluidics flow cell and an interdigitated microelectrode for the specific detection of H5N1 AIV. The gold surface of the interdigitated microelectrode embedded in a microfluidics flow cell was modified using streptavidin. The biotinylated aptamer against H5N1 was then immobilized on the electrode surface using biotin--streptavidin binding. The target virus was captured on the microelectrode surface, causing an increase in impedance magnitude. The aptasensor had a detection time of 30 min with a detection limit of 0.0128 hemagglutinin units (HAU). Scanning electron microscopy confirmed the binding of the target virus onto the electrode surface. The DNA aptamer was specific to H5N1 and had no cross-reaction to other subtypes of AIV (e.g., H1N1, H2N2, H7N2). The newly developed aptasensor offers a portable, rapid, low-cost alternative to current methods with the same sensitivity and specificity. [ABSTRACT FROM AUTHOR]

A typical solid-state drive contains several independent channels that can be operated in parallel. To exploit this channel-level parallelism, a variety of works proposed to split consecutive write sequences into small segments and schedule them to different channels. This scheme exploits the parallelism but breaks the spatial locality of write traffic; thus, it is able to significantly degrade the efficiency of garbage collection. This paper proposes a channelaware write reordering (CAWR) mechanism to schedule write requests to different channels more intelligently. The novel mechanism encapsulates correlated pages into a cluster beforehand. All pages belonging to a cluster are scheduled to the same channels to exploit spatial locality, while different clusters are scheduled to different channels to exploit the parallelism. As CAWR covers both garbage collection and I/O performance, it outperforms existing schemes significantly. Trace-driven simulation results demonstrate that the CAWR mechanism reduces the average response time by 26% on average and decreases the valid page copies by 10% on average, while achieving a similar hit ratio to that of existing mechanisms. [ABSTRACT FROM AUTHOR]

Rapid and specific detection of avian influenza virus (AIV) is urgently needed due to the concerns over the potential outbreaks of highly pathogenic H5N1 influenza in animals and humans. Aptamers are artificial oligonucleic acids that can bind specific target molecules, and show comparable affinity for target viruses and better thermal stability than monoclonal antibodies. The objective of this research was to use a DNA-aptamer as the specific recognition element in a portable Surface Plasmon Resonance (SPR) biosensor for rapid detection of AIV H5N1 in poultry swab samples. A SPR biosensor was fabricated using selected aptamers that were biotinylated and then immobilized on the sensor gold surface coated with streptavidin via streptavidin-biotin binding. The immobilized aptamers captured AIV H5N1 in a sample solution, which caused an increase in the refraction index (RI). After optimizing the streptavidin and aptamer parameters, the results showed that the RI value was linearly related (R2 = 0.99) to the concentration of AIV in the range of 0.128 to 1.28 HAU. Negligible signal (<4% of H5N1) was observed from six non-target AIV subtypes. The AIV H5N1 in poultry swab samples with concentrations of 0.128 to 12.8 HAU could be detected using this aptasensor in 1.5 h. Keywords: aptamer; surface plasmon resonance; biosensor [ABSTRACT FROM AUTHOR]

Plastic inserts may enhance the performance of a product, enlarge its application scope or make it possible to apply plastic in situations where this material may not have been applied previously. The type of insert may vary from metal to plastic, ceramic, glass, or fireproof materials on a macro-scale. Glass is a typical type of fragile material. As an insert, this fragile part is easily broken or scraped during the processing of PVC injection molding, and flashes may occur at the shared boundaries of PVC and insert. The proper gap should be set between the core or cavity and the insert. In this paper, the function of the pressure attenuation and the shear flowing distribution variation along the runner is set to get the optimal gap distribution. First, two types of power loss functions are set. These functions relate pressure and shearing flow during transverse filling in a runner. Second, the summation of the two types of power loss is obtained using functions that are proportional and inversely proportional to the mold gap. Third, by discretizeing the long and narrow runner, according to the pressure distribution, the optimal gap is obtained at each point. Next, the simplified algorithm and the post-processing calculations of the fitting gap at arbitrary points are proposed. As an application, the experimental procedures and results of injection forming circular freeform materials which are used in vehicles as PVC-lined safety inserts are described in detail. Through geometrical measurement and mechanical testing on PVC and glass, we have shown that the mold gap distribution and the processing operations can ensure the technical requirement of the plastic part with fragile insert. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this paper is to investigate the corrosion and the tarnish behaviour of 925Ag75Cu and 925Ag40Cu35Zn alloys in synthetic sweat at 37 °C and H2S atmosphere at room temperature. The alloys were in two hardening states, viz., aging at 250 °C for 4 h and 70 % cold rolling + aging at 200 °C for 4 h, and tested by means of static corrosion, examined by XRD, SEM, EDS and XPS. The results show the corrosion and the tarnish in synthetic sweat at 37 °C of these two 925Ag alloys are induced by Cl− and OH− anions. The tarnish of 925Ag40Cu35Zn alloy is much slower than that of 925Ag75Cu alloy, and the white AgCl and the grayish black Ag2O produced by corrosion are difficult to deposit on the surface of 925Ag40Cu35Zn alloy resulting in grayish black corrosion film. The corrosion and the tarnish in H2S atmosphere at room temperature of these two 925Ag alloys are induced by S2− anion. The corrosion and the tarnish of 925Ag40Cu35Zn alloy are much slower than 925Ag75Cu alloy. This is because Zn in 925Ag40Cu35Zn alloy reacts earliest with H2S to form white ZnS, which significantly retards the reaction between Ag or/and Cu and H2S to form grayish black Ag2S and black Cu2S. [Copyright &y& Elsevier]

A novel TiO 2nanowire bundle microelectrode based immunosensor was demonstrated as a more sensitive, specific, and rapid technology for detection of Listeria monocytogenes. TiO 2nanowire bundle was prepared through a hydrothermal reaction of alkali with TiO 2powder and connected to gold microelectrodes with mask welding. Monoclonal antibodies were immobilized on the surface of a TiO 2nanowire bundle to specifically capture L. monocytogenes. Impedance change caused by the nanowire−antibody−bacteria complex was measured and correlated to bacterial number. This nanowire bundle based immunosensor could detect as low as 10 2cfu/ml of L. monocytogenesin 1 h without significant interference from other foodborne pathogens. [ABSTRACT FROM AUTHOR]

PURPOSE: To investigate the cervical vertebral health status of ordinary college students, analyze the factors affecting the cervical vertebrae of ordinary college students. METHODS: The "Investigation on Cervical Spine Health Status of College Students" questionnaires were distributed to college students (18-25 years old). A total of 578 questionnaires were returned, including 262 for male and 316 for female. Chi-square test is used for counting data. Single Factor Logistic Regression Analysis was used to analyze the factors influencing neck and shoulder pain. RESULTS: 1) 71.1% of college students have occasional mild neck and shoulder pain, and prevalence rate of female is higher than that of male (56.5 vs 43.5%, P < 0.05). 2) Among students with neck and shoulder pain, more than 50% of them have the following symptoms: occasional or even frequent dizziness, fatigue or heavy head (71.5%, P<0.01); inattention (59.2%, P<0.01); insomnia, dreaminess or chest tightness (59.4%, P<0.01); anxiety and irritability because of neck and shoulder pain (53.3%, P < 0.01). 3) Lying in bed watching TV (OR = 1.707, P < 0.01, 95%CI: [1.086, 2.684]), working at the desk for 4 hours continuously with an interval of less than 10 minutes (OR= 2.573, P < 0.01, 95%CI: [1.565, 4.228]), using electronic equipment for 4 hours continuously with an interval of less than 10 minutes (OR = 2.100, P < 0.01, 95%CI: [1.353, 3.260]) and the number of physical exercises in a week (OR = 0.741, P < 0.01, 95%CI: [0.598, 0.918]) affect the cervical problems of college students. 4) 56.5% of the college students with neck and shoulder pain choose massage or rest by themselves or others to solve their neck and shoulder problem, and only 29.8% of them choose traction. 5) In terms of cognition of cervical problems, more than 80% of people do not know much about it, but nearly 90% of them are willing to improve cervical problems through sports. CONCLUSIONS: Sedentary behavior is the main cause of neck and shoulder pain among college students. Strengthening physical exercise and increasing college students' attention to cervical problems are conducive to preventing the occurrence of neck and shoulder pain. [ABSTRACT FROM AUTHOR]

Avian toe-legged disease poses serious threat to ostrich farms worldwide. Despite its severity, the underlying pathogenic mechanism of toe- legged disease in ostrich remains elusive. Our study aims to explore the connection between toe leg disease and articular cartilage with prime focus on the underlying mechanism in the pathogenesis of the disease. For this purpose, 18 male ostriches, comprising three groups: group A (6 healthy), group B (6 with mild disease), and group C (6 with severe disease), all aged 3 months were selected. Histopathological changes in tarsal joints of ostriches with leg and toe disease were observed using radiological examination (X-ray), Hematoxylin and Eosin (H&E), Safranin O-staining, and Masson trichome staining. The chondrocytes were evaluated for apoptosis and changes in the expression of Bcl-2 and Bax in articular cartilage using TdTmediated dUTP Nick-End Labeling (TUNEL), and Immunohistochemistry (IHC). The results indicated that the tarsal joints of ostriches with leg and toe disease exhibit pathological changes such as thickening of the periosteum, decreased number of chondrocytes, shallow staining of cartilage matrix, incomplete tidemark, and decreased collagen. In comparison to Group A, there was a significant decrease in cell apoptosis (P<0.01) while the expression of apoptosis proteins Bcl-2 and Bax was found to be significantly increased (P<0.01) in the tarsal cartilage of groups B and C. In conclusion, our findings suggest that excessive chondrocyte apoptosis may be the underlying pathogenic mechanism for toe and leg disease in ostriches. These findings offer valuable insights for the diagnosis and treatment of ostriches with toe-legged disease. [ABSTRACT FROM AUTHOR]

Accurate and efficient estimation of tension in hangers is very important since hangers are the vital component of suspension bridges. But for hangers with shock absorber, the existing tension estimation methods are not suitable because they are based on a single cable model and cannot consider the effect of shock absorbers. To this end, the effect of the shock absorber is taken into account by using the degree-of-freedom condensation method, and a finite element method for tension estimation of hangers with shock absorber is proposed in this paper. Finally, the proposed method is applied in the Aizhai Bridge and Huangpu Pearl River Bridge to estimate the tension of hangers with shock absorber, the tested results show that as compared with other methods, the proposed method is a more accurate and convenient method for engineering application. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of atomized slightly acidic electrolyzed water (SAEW) treatment during vacuum precooling on the quality of Chinese little greens during low temperature circulation and shelf life. The effects of vacuum precooling, vacuum precooling combined with tap water treatment and vacuum precooling combined with SAEW treatment on the appearance quality, nutritional components, antioxidant substances and free radical scavenging capacity of Chinese little greens were analyzed under low temperature ((4 ± 1) ℃) distribution and shelf conditions ((20 ± 1) ℃). The results showed that vacuum precooling + tap water treatment could slow down the yellowing and wilting, maintain higher nutritional quality and antioxidant capacity of Chinese little greens when compared to the control (without vacuum precooling or spraying tap water) and vacuum precooling groups. Furthermore, compared to vacuum precooling + tap water treatment, vacuum precooling + SAEW treatment could delay the yellowing and ageing process, suppress the decline in sensory quality and chlorophyll content, maintain higher titratable acid, soluble protein and soluble sugar contents, and retard the decrease in the contents of bioactive substances such as carotenoids, ascorbic acid, folic acid and total phenols and free radical (1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radial and superoxide anion radical) scavenging capacity, thereby inhibiting the accumulation of nitrite and malondialdehyde and prolonging the shelf life of postharvest Chinese little greens. It is thus clear that the combination of vacuum precooling with SAEW treatment can effectively relieve the yellowing and ageing process of postharvest Chinese little greens and maintain good commodity characteristics.