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Extracorporeal magnetic driving approach is a potential alternative to replace conventional intra-driving methods for the axial flow blood pump, which can minimize external infection brought by through-skin wires and simplify the internal structure. The investigation has been undertaken to study electromagnetic and hydrodynamic characteristics of four novel large gap extracorporeal in magnetic driving systems varying in connection of structure, inclination angular and magnet pole number. Using finite element analysis based simulation and empirical verification, comparison upon performance of four different extracorporeal magnetic schemes was conducted. Using ANSYS, numerical solutions have been obtained consisting of vector plots of 3D magnetic field density and flux plots of 2D mean torque data. W-shape as a preferred scheme has 71.52% and 148.32% increments of the magnetic field density and mean torque on the axial flow blood pump, respectively, over D-T-shape. Experiment has verified the simulation results by direct measurement of magnetic field density, flow rate and pressure head, which has the magnetic field density and torque increased by 38.70% and 145.56%, respectively. Both simulation and experiment indicate that the addition of connection, inclination and magnet pole number would boost the performance; thus, the W-shape is the preferred system. [ABSTRACT FROM AUTHOR]

In order to obtain the dynamic law of blood pump under a large gap and achieve optimal control of pulse frequency during the start-up process, dynamic characteristics of the blood pump were studied. First, the driving torque of the large gap magnetic drive system was solved. Second, the dynamic equilibrium equation, the continuity equation of water flow and the net head-flow equation of the pump during the start-up process were deduced. Then a mathematical model of dynamic characteristics of the pump was established. Taking the start-up process under a coupling distance of 60 mm between the driving electromagnet and the driven permanent magnet as an example, the mathematical model was solved using MATLAB, and the relation between various important parameters such as speed, flow with regard to time were obtained. Then the optimal driver was designed according to the discretization of the acceleration curve and used for blood pump experimental research. By comparing the curves resulted from the numerical solution of the dynamic mathematical model with the experimental characteristic curves, the correctness of the model was demonstrated. The experimental results also confirm that, compared to the driver based on the linear acceleration curve, the optimal driver can significantly shorten the acceleration time, and the efficiency of energy transfer of the driving system is comparatively higher. [ABSTRACT FROM AUTHOR]

Objective: To investigate the proportions of CD4+CD25high T cells and forkhead box p3 (FOXP3) expression in peripheral blood and decidua in patients with unexplained recurrent spontaneous abortion (URSA). Design: Prospective clinical study. Setting: University hospital. Patient(s): 125 URSA patients, 35 normal early pregnant women, and 28 normal nonpregnant women. Intervention(s): Measurements of CD4+CD25high T cells and FOXP3 expression in peripheral blood and decidua. Main Outcome Measure(s): The proportions of CD4+CD25high T cells and FOXP3 expression. Result(s): In peripheral blood, statistically significantly higher proportions of CD4+CD25high T cells and FOXP3 expression were observed in normal early pregnant women compared with normal nonpregnant women and URSA patients; a statistically significantly lower proportion of CD4+CD25high T cells was observed in nonpregnant URSA patients compared with URSA patients who had early miscarriages and normal nonpregnant women. In the decidua, statistically significantly lower proportions of CD4+CD25high T cells and FOXP3 expression were found in URSA patients with early miscarriages compared with normal early pregnant women. Conclusion(s): The CD4+CD25high T cells may play an important role in maintaining a normal pregnancy. The reduction in CD4+CD25high T cells may involve in the pathogenesis of URSA, and is correlated with lower FOXP3 expression. [ABSTRACT FROM AUTHOR]

Highlights • Sandpaper-molded pressure sensor was developed for electronic skins. • The device sensitivity is modulated by the grit number of sandpaper. • The device have broad sensing range and mechanical stability. • The device can monitor various external stimuli through NFC communication. Abstract Wearable pressure sensors fabricated with sandpaper-molded carbon nanotube-polydimethylsiloxane (CNT-PDMS) electrodes are developed for electronic skins. Compared to the lithography method, widely adopted to prepare pressure sensors based on microstructures, the sandpaper molding method is much more cost-effective and scalable. The microhumps templated from the sandpaper are suggested to amplify the external stimuli during device deformation, leading to an improved sensitivity that is ∼20 times of the one without microstructures. Moreover, the detectable range of the sandpaper –molded device covers pressures from 5.0 Pa to 50.0 kPa, with a stimuli-response time around 0.19 s and a cycling stability more than 5000 cycles. The sandpaper-molded devices have been explored for external stimuli detection such as pressing, bending and twisting, and human health monitoring including phonation and pulsing. [ABSTRACT FROM AUTHOR]

Compliant amplification mechanisms amplify input displacement in the desired output direction. However, owing to structural design, parasitic motion can easily be produced in an unexpected direction. The parasitic motion has a negative effect on the motion accuracy of the mechanism. To solve this problem, a topology optimization method for compliant amplification mechanisms with low parasitic displacement was proposed. Based on the variable density topology optimization method, the topology optimization model of the compliant amplification mechanism was established with the goal of increasing the output displacement and reducing the parasitic displacement. Volume ratio was set as constraint condition. The optimization criterion method were used to solve the problem and topology optimized amplification mechanisms (TOAMs) were obtained. Simultaneously, the configuration characteristics and displacement amplification ratios of the mechanism under different virtual spring stiffnesses were compared. To verify the validity of the method, the performance of the TOAM and the typical amplification mechanism (TAM) were compared using finite element simulation. The displacement amplification ratio is 5.95 and 3.17, and the relative parasitic displacement is 0.6% and 10.27%, respectively. Finally, the performance of the TOAM and the TAM was verified by experiments. The displacement amplification ratio is 5.72 and 3.06, and the relative parasitic displacement is 0.95% and 10.64%, respectively. Simulation and experimental results show that the TOAM has a larger displacement amplification ratio and a lower parasitic displacement, which verifies the validity of this method. [ABSTRACT FROM AUTHOR]

The existing process for the preparation of cladded rebars is too complicated for large-scale industrial production. Therefore, this paper proposes a 55#/316L rebar preparation method based on vacuum hot rolling. The microstructure and mechanical properties of the composite interface of the rebar, along with the connecting technique, were studied using transmission electron microscopy, X-ray diffraction, and Vickers hardness testing. The obtained results showed that the minimum thickness of the 55#/316L rebar cladding was 0.25 mm, which was twice that of the M 329M/M 329-11 design standard used in the United States of America. Due to the diffusion of carbon, large numbers of second-phase particles were precipitated on the stainless-steel side, which resulted in intergranular chromium depletion. After multi-pass hot rolling, the minimum bonding strength of the composite interface reached 316.58 MPa, which was considerably higher than the specified value of 210 MPa. In addition, we designed three different types of rebar connection joints: sleeve, groove-welded, and bar-welded. According to the tensile test, the bar-welded joint had higher yield strength (385 MPa) and tensile strength (665 MPa) than the base rebar (376.6 MPa and 655 MPa), as well as a very high corrosion resistance. [ABSTRACT FROM AUTHOR]

Clad rebar is one of the key structures of marine and construction services. Therefore, it is of great importance to acknowledge the mechanical property parameters of the composite region in the structural integrity evaluation of clad rebar. The different base materials of clad rebar (20MnSiV/316L steel, 35#/316L steel, 45#/316L steel, and 55#/316L steel) are researched in this study. The composite area is further refined, and simultaneously, a refinement model of the composite region of clad rebar is established. In view of the fact that a surface hardness experiment is quite easy to conduct, a proposed method consists of obtaining the mechanical property parameters of materials using the surface hardness test. The mechanical property parameters are acquired; moreover, the relationship between yield stress and surface hardness of the stainless steel clad rebar is set up. We used this method to acquire the mechanical parameters of a composite surface uneven area of clad rebar, and we established a mechanical parameters mathematics model of clad rebar, it is a significant basis for a structural integrity evaluation of cladding materials. [ABSTRACT FROM AUTHOR]

Rough- and intermediate-rolled composite billets and finished clad rebars were cut using flying shears. The law of metal rheology and the mechanism of composite interface generation during clad rebar formation were then investigated using metallographic microscopy, electron backscatter diffraction, and scanning electron microscopy. The radial deformation trend of the clad rebars was greater than that of HRB400 rebars and "ears" were more likely to appear during the rolling process. The widths of the decarburization and composite zones and diffusion distances of each element decreased as the cumulative reduction rate increased. Furthermore, as deformation increased, the number of oxides on the composite interface significantly decreased, the proportion of recrystallized grains increased, and the grains became more refined. These changes led to increases in the bond and tensile strengths of the composite interface. According to the research above, the pass filling degree should be within 0.85–0.9 and the cumulative reduction rate should be over 80% when rolling clad rebars. [ABSTRACT FROM AUTHOR]

The extraordinary work hardening ability and fracture toughness of the face-centered cubic medium-entropy alloy (MEA) at cryogenic temperature make them good candidates for harsh applications. In this work, we developed a hierarchical twin architecture in coarse grained CoCrNi MEA using multidirectional cryoforging (MDCF) technique and low-temperature annealing. The unique substructure brought a notable enhancement in the cryogenic tensile strength-ductility balance, as well as an impressive 106-cycle fatigue strength of up to 1100 MPa at cryogenic temperature, which is superior to other cryogenic alloys. The exceptional fatigue property of MDCF-MEA is ascribed to the synergistic effect of high-density dislocations and a dense nanotwin/microband network, providing high strength and the ability to suppress local surface roughening and crack initiation. Our work demonstrates a practical route to further extend CoCrNi MEA for the cryogenic application. [Display omitted] [ABSTRACT FROM AUTHOR]

• Computational modeling of heavy crude oil viscosity. • Machine learning (ML) models for estimation of fluid properties. • Utilization of earthworm optimization algorithm to optimize the hyper-parameters. The properties of crude oil are of great importance for efficient recovery of oil from oil fields. The properties are primarily used in reservoir simulations for prediction of oil recovery in order to save time and obtain the best recovery. Among various crude oil properties, viscosity is the most important one which should be precisely simulated. In this work, a novel approach based on machine learning is developed for estimation of crude oil viscosity as function of input parameters. Multiple distinct tree-based ensemble models are applied on the available dataset in this work to predict heavy-oil viscosity. AdaBoost Decision Trees (ADA-DT), Random Forest (RF), and Extremely Randomized Trees (ERT) are selected tree-based ensembles that used in this work for the simulation of oil viscosity. An Isolation Forest is applied on the dataset to remove outliers and also the earthworm optimization algorithm (EWA) is employed to find the optimum values of models' hyper-parameters. Optimized models of ADA-DT, ERT, and RF have RMSE error rates of 35.42, 27.02, and 58.71. Thus, ERT is selected as the best model of the dataset used in this work. [ABSTRACT FROM AUTHOR]

Highlights • Pressure sensor was developed using CNT-wrapped PDMS microspheres (MSs). • The preparation method for the MSs is simple and scalable. • The device with MSs has a larger sensitivity than the one without MSs. • The sensors with MSs can be used for detecting physiological signals. Abstract High-performance flexible pressure sensors are highly demanded in wearable electronics for various applications. Herein, a flexible pressure sensor was designed using carbon nanotube (CNT)-wrapped polydimethylsiloxane (PDMS) microspheres (MSs). Compared to the device with flat configuration, the sensor with CNT-wrapped PDMS MSs has an enhanced sensitivity of −0.111 kPa−1, with a lowest detectable pressure of 0.02 kPa, response time approximately 0.1 s, as well as a long-term dynamic stability more than 10,000 cycles. The sensors with CNT-wrapped PDMS MSs show the potential to be integrated into wearable electronics for real-timely monitoring the physiological signals. [ABSTRACT FROM AUTHOR]

Highlights • Laser-microengineered pressure sensor was developed for tactile sensing. • The laser-engineered microstructures lead to the enhanced sensitivity. • The device has broad sensing range and mechanical stability. • The device can be used for detecting various external stimuli. Abstract In this study, a laser-microengineered wearable pressure sensor was developed. The sensor offers a sensing range from 0.005 to 50.0 kPa, a sensitivity approximately -0.107 kPa−1, and high durability (>10,000 cycles). The finite element simulation shows that the external forces are amplified and transmitted by the laser-engineered microstructures, contributing to the enhanced sensitivity of the device. The laser-microengineered sensors are promising to be applied in the electronic skin for detecting various external stimuli. [ABSTRACT FROM AUTHOR]

Sensor, the device to detect certain information and convert into corresponding output signals, is of key importance to structural health monitoring (SHM) system. Compared with the traditional sensor, antenna sensor can reduce the size of sensor system and avoid the peripheral circuits, but there are still many challenges in the research of antenna sensors, such as low sensitivity and single sensing function. Here, a dipole antenna responsive to the strain and humidity is proposed. The dipole antenna is prepared by an ordinary office inkjet printer, besides, the capabilities of proposed dipole antenna to sensing the strain and humidity were verified by experiments, however, the effect of temperature is negligible within 25–45 °C. The sensitivities of antenna sensor to sensing applied strain and humidity are − 24.03 kHz/με (−7.63 ppm/με), − 12.38 MHz/%RH (−2123 ppm/%RH). BP network trained with the experimental data can be well used to decouple of the humidity and strain signal response. The antenna sensor proposed in the study is cost-effective and possesses the excellent strain and humidity sensing ability, which provides a new possibility for the sensors of SHM systems. [Display omitted] • A flexible multimode antenna sensor is developed in this study. • The sensor could be used for detection of strain and humidity simultaneously. • The sensor has a potential application in SHM systems. [ABSTRACT FROM AUTHOR]

• A sensor matrix is fabricated by fs laser micro-fabrication. • The performance of the pressure sensing layer is enhanced by the microstructures. • The temperature sensing layer has TCR higher than commercial sensors. • The device can monitor thermal and mechanical stimuli simultaneously. Flexible sensor matrix with functionalities for multiple stimuli detection has prospect applications in structural health monitoring, internet of things, soft robotics, etc. However, fabrication of the sensor matrix in a simple, highly efficient, and scalable manner is still a challenge. To address this, a femtosecond (fs) laser micro-fabrication method is developed to fabricate a sensor matrix integrated with temperature and pressure sensor arrays. Through the programmable control of laser irradiation manner including scanning velocity, laser power, and laser irradiation intervals, the temperature and pressure sensor arrays were fabricated by the fs laser. The temperature sensors have a temperature coefficient of resistance of −0.52%/°C, higher than commercial temperature sensor based on platinum. The pressure sensors deliver a sensitivity of −2.01 kPa−1, a response speed of 0.030 s, a detection window from 0.001 to 80 kPa, and high mechanical stability. When the fs laser micro-fabricated pressure and temperature sensor arrays are integrated together, the sensor matrix could simultaneously detect external mechanical and thermal stimuli. [ABSTRACT FROM AUTHOR]

• Sharp-tip discharge could accelerate the O 2 dissociation. • Energy barrier for O 2 dissociation varies on the discharge intensity. • Electrical potential is inhomogeneous on the oxide layer. • The transfer of electron is anisotropic across the oxide layer. The traditional wisdom that the transfer of electron is isotropic across the oxide layer in Cabrera-Mott model, is powerless in the explanation of reactive nucleation of oxide NWs. In the study, the effect of electron transfer on the dissociation reaction around the tip of oxide NWs is uncovered using molecular dynamics simulation. Based on the simulation, a tip-reaction model is proposed in the interpretation of nucleation of oxide NWs and verified by kelvin probe force microscopy testing. The anisotropy of electron transfer across the oxide layer is found to play a key role in the reactive nucleation of oxide NWs. [ABSTRACT FROM AUTHOR]

An extrusion printing method is developed to prepare carbon nanotube (CNT)-coated microstructured elastomer fibers for resistive and capacitive wearable pressure sensors. The resistive and capacitive sensors exhibit high sensitivity, low detectable limit, fast response time and good mechanical durability. The device can be employed to measure various external stimuli. • Extrusion printing method is developed to prepare microstructured elastomer fibers, which is simple and scalable. • The carbon nanotube (CNT)-coated elastomer fibers can be used for resistive and capacitive wearable pressure sensors. • The devices with CNT-coated elastomer fibers has a higher sensitivity, faster response time, lower detection limit. • The sensors with CNT-coated elastomer fibers can be used for detecting various external stimuli. Microstructured wearable pressure sensors with high sensing performance have promising applications in soft robots, wearable electronics, and biomedical devices. However, current methods for the fabrication of the devices are complex, cost-ineffective, or time-consuming. Inspired by the crystalline ice plant having tiny crystalline beads on its stem, an extrusion printing method is developed to prepare carbon nanotube (CNT)-coated microstructured elastomer fibers for resistive and capacitive wearable pressure sensors. Due to the microstructures on the CNT-coated elastomer fiber, the resistive device has a sensitivity eight times higher than the smooth one, with a fast response time (20 ms), and a detectable limit of ∼5.0 Pa. The capacitive device constructed using CNT-coated microstructured elastomer fiber provides a highest sensitivity of 0.17 kPa−1, a response time around 25 ms, and a detectable limit of 0.02 kPa. The microstructured elastomer fiber based devices demonstrate the ability in measuring various external stimuli, exhibiting the potential for the aforementioned applications. [ABSTRACT FROM AUTHOR]

Corrosion-resistant steel plays a vital role in marine steel structures. This study developed an SS304/HRB400 stainless-steel-clad rebar for application in a cross-sea bridge in Zhejiang Province. CO 2 gas shielded welding was employed in the prefabricated steel structure, with SS304 steel as the welding wire. This study investigated the welding on the corrosion resistance of clad rebars and explored corrosion protection measures for welded joints.The results indicated that refined grains appeared in both stainless steel and carbon steel due to distinct dynamic recrystallization (DRX) during welding. The corrosion resistance, as determined by potentiodynamic polarization curve analysis of the material's interaction with the solution ranked as follows: clad rebar (polished) > clad rebar welding (CRW) > painting the clad rebar after welding (PCRW) > clad rebar (unpolished) > carbon-steel welding (CSW) > carbon-steel bar > cold spraying zinc after clad rebar welding (ZCRW). However, an accelerated corrosion test with four samples for 600 s with a corrosion current of 0.8 A revealed minimal corrosion damage on zinc-coated surfaces. Hence, welding joints for clad steel structures are considered feasible and must be subject to cold zinc spraying after polishing to enhance their corrosion resistance., (© 2024. The Author(s).)

Motion blur is common in video tracking and detection, and severe motion blur can lead to failure in tracking and detection. In this work, a motion-blur hysteresis phenomenon (MBHP) was discovered, which has an impact on tracking and detection accuracy as well as image annotation. In order to accurately quantify MBHP, this paper proposes a motion-blur dataset construction method based on a motion-blur operator (MBO) generation method and self-similar object images, and designs APSF, a MBO generation method. The optimized sub-pixel estimation method of the point spread function (SPEPSF) is used to demonstrate the accuracy and robustness of the APSF method, showing the maximum error (ME) of APSF to be smaller than others (reduced by 86%, when motion-blur length > 20, motion-blur angle = 0), and the mean square error (MSE) of APSF to be smaller than others (reduced by 65.67% when motion-blur angle = 0). A fast image matching method based on a fast correlation response coefficient (FAST-PCC) and improved KCF were used with the motion-blur dataset to quantify MBHP. The results show that MBHP exists significantly when the motion blur changes and the error caused by MBHP is close to half of the difference of the motion-blur length between two consecutive frames. A general flow chart of visual tracking displacement detection with error compensation for MBHP was designed, and three methods for calculating compensation values were proposed: compensation values based on inter-frame displacement estimation error, SPEPSF, and no-reference image quality assessment (NR-IQA) indicators. Additionally, the implementation experiments showed that this error can be reduced by more than 96%.

Background: Epidemiological studies have revealed that sulfur dioxides (SO 2 ) can increase the risk of pregnancy complications such as missed abortion in the first trimester, stillbirth, preterm birth, small for gestational age, gestational diabetes mellitus and preeclampsia, but the mechanisms underlying these findings remains unknown. What is known, however, is that trophoblasts, a type of fetal cell exerting vital immunologic functions to maintain a successful pregnancy, are usually involved in the pathogenic mechanism of pregnancy complications., Objective: To study the effect of SO 2 derivatives (bisulfite and sulfite, 1:3 M/M) on the function of trophoblasts., Methods: Swan.71 trophoblast cells were treated with various concentrations of SO 2 derivatives to determine the effect of SO 2 derivatives on cellular viability by CKK8. Flow cytometry was performed to analyze the effect of SO 2 derivatives on apoptosis, cell cycle and intracellular ROS. Wound healing assay and transwell assay were conducted to examine the migration and invasion of Swan.71 cells. Inflammation-related cytokines in the supernatant (IL-1β, IL-6, IL-8, IL-10 and TNF-α) were measured by IMMULITE®1000 Systems (SIEMENS). The expression level of NLRP3, Caspase1, MMP9, MMP2, STAT3, and p-STAT3 were evaluated by Western Blotting., Results: Exposure to SO 2 derivatives significantly decreased cellular viability, arrested cell cycle at S/G2/M phase and induced cell apoptosis of Swan.71 trophoblasts. In addition, the migration and invasion of Swan.71 cell were significantly inhibited. SO 2 derivatives also significantly increased IL-1β secretion while it is NLRP3/Caspase1 independent. IL-6 secretion was significant inhibited accompanied by decreased STAT3 phosphorylation and expression of MMP2 and MMP9. The intracellular ROS level was significantly suppressed by SO 2 derivatives., Conclusion: SO 2 derivatives exert toxic effects on trophoblasts which results in: suppressing cellular viability and intracellular ROS level, interfering with cell proliferation through arresting cell cycle, inducing cell apoptosis, disturbing inflammation-related cytokines secretion and inhibiting motility. Decreased ROS/IL-6/STAT3 levels play a role in inhibited cell viability, cell cycle arrest, apoptosis and defective motility., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The association between plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism and recurrent pregnancy loss (RPL) risk is still contradictory. We thus performed a meta-analysis., Material and Methods: Relevant studies were searched for in PubMed, Web of Science, Embase, and Cochrane Library. An odds ratio (OR) with a 95% confidence interval (CI) was used to assess the association between PAI-1 4G/5G polymorphism and RPL risk., Results: A total of 22 studies with 4306 cases and 3076 controls were included in this meta-analysis. We found that PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk (OR=1.89; 95% CI 1.34-2.67; P=0.0003). In the subgroup analysis by race, PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk in Caucasians (OR=2.23; 95% CI 1.44-3.46; P=0.0003). However, no significant association was observed in Asians (OR=1.47; 95% CI 0.84-2.59; P=0.18)., Conclusions: In conclusion, this meta-analysis suggests that PAI-1 4G/5G polymorphism might be associated with RPL development in Caucasians.

The control arithmetic is proposed for axial blood pump driven by extracorporeal alternating magnet field based on ventricular work. According to health physiological parameters, the control model is verified by calculation and experiment. The control model used for driving blood pump is derived from the relationship of natural heart and artificial heart. By comparison with others, the control arithmetic based on ventricular work is more helpful in appraising the property of left ventricular aided device (LVAD), in meeting human body's natural need, and in effective use of motor for avoiding motor running at high speed and hence preventing the blood from the destruction caused by a blood pump at high temperature.

This essay introduces the new development of rotary impeller blood pump technology in three design aspects, i.e. pump structure, bearing and seal, control system. Moreover, an expectation for the development trend of artificial heart technology is presented.