Search

Thermoelectric materials’ unique merits attract considerable attention. Among those merits, the straight transformation between heat and electricity makes this material potential. The energy of the human body is released in the form of heat, which can be transformed into effective electricity by wearable thermoelectric materials. The nanotechnology‐based materials improve thermoelectric properties and heat absorption abilities for nanostructures will help maintain good electrical conductivity and reduce thermal conductivity. Poly(3,4‐ethylenedioxythiophene) (PEDOT) is extensively investigated for its high conductivity, flexibility, good transparency, and so on. This article reviews its mechanism and describes the preparation techniques and thermoelectric properties of nanotechnology‐based PEDOT, inorganic semiconductor composite, and low‐dimensional metal composite thermoelectric materials. The recent research progress on PEDOT‐based thermoelectric materials, the application of wearable low‐dimensional PEDOT‐based thermoelectric materials, and methods to improve the thermoelectric performance of PEDOT‐based composite materials, device design, and commercialization are specifically discussed.

Background: Gallstone disease is one of the most common gastrointestinal disorders. Despite extensive research exploring the risk factors associated with gallstones, the association between depressive symptoms and gallstones remains inadequately understood. This study aimed to assess the association between depressive symptoms and the prevalence of gallstones among adults in the United States. Methods: In this study, a cross-sectional design utilized data from the National Health and Nutrition Examination Survey (NHANES) spanning the years 2017 to 2020. The assessment of depressive symptoms was conducted through the utilization of the Patient Health Questionnaire-9 (PHQ-9), which assigns total scores ranging from 0 to 27. Participants with PHQ-9 scores equal to or exceeding 10 were categorized as having clinically relevant depressive symptoms. Multivariable adjusted logistic regression and subgroup analysis were used to assess the association between depressive symptoms and gallstone prevalence. Results: A total of 7,797 participants aged 20 years or older were enrolled in this study, of whom 835 had a self-reported history of gallstones. After multiple adjustments, each one-point increase in PHQ-9 scores was associated with a 5 % increase in the risk of gallstones (odds ratio [OR], 1.05; 95 % confidence interval [CI], 1.03, 1.07, P

Abstract Apatinib was the first anti-angiogenic agent approved for treatment of metastatic gastric cancer (GC). However, the emergence of resistance was inevitable. Thus investigating new and valuable off-target effect of apatinib directly against cancer cells is of great significance. Here, we identified extra spindle pole bodies-like 1 (ESPL1) was responsible for apatinib resistance in GC cells through CRISPR genome-wide gain-of-function screening. Loss of function studies further showed that ESPL1 inhibition suppressed cell proliferation, migration and promoted apoptosis in vitro, and accordingly ESPL1 knockdown sensitized GC cells to apatinib. In addition, we found ESPL1 interacted with mouse double minute 2 (MDM2), a E3 ubiquitin protein ligase, and the combination of MDM2 siRNA with apatinib synergistically ameliorated the resistance induced by ESPL1 overexpression. In summary, our study indicated that ESPL1 played a critical role in apatinib resistance in GC cells. Inhibition of MDM2 could rescue the sensitivity of GC cells to apatinib and reverse ESPL1-mediated resistance.

This study investigates the impact of math-gender stereotypes on students’ academic performance using data from the China Education Panel Survey (CEPS), which surveyed nationally representative middle schools in China. Our sample comprises over 2000 seventh-grade students, with an average age of 13 and a standard deviation of 0.711. Among these students, 52.4% are male, and 47.6% are female. Employing a fixed effects model and instrumental variable, our findings are as follows. First, over half of the male students believe that boys are better at math than girls, and they also perceive that their parents and society hold the same belief. In contrast, fewer than half of the female students hold this belief or perception. Intriguingly, among these students, female math performance surpasses that of males. Second, stereotypes hinder female math performance, especially among low-achieving ones, while benefiting high-achieving male students. Finally, perceptions of societal stereotypes have the greatest effect on math performance, followed by self-stereotypes and perceptions of parental stereotypes. Understanding the implications of these findings highlights the importance of addressing math-gender stereotypes to promote equal participation and success for both genders in STEM fields.

A dual-loop current control is discussed for LCL-type shunt active power filters (APFs), where inverter-side current feedback and point of common coupling (PCC) voltage feedforward both provide active damping (AD) effects for LCL resonance. However, two ADs are equivalently applied to different elements of LCL filter with narrow damping boundaries, which causes less robustness against grid impedance variation. Hence, this paper has presented a comprehensive approach to strengthen the system robustness against grid impedance variation. On the basis of phase compensated resonant unit, a delay-compensation scheme is firstly proposed to extend the damping boundary of inverter-side current feedback up to almost Nyquist frequency ( $f_{s}/2$ ). Theory analysis considering PCC voltage feedforward indicates that the control system can keep robust to grid impedance when the initial LCL resonance frequency falls between $f_{s}/3$ and the extended damping boundary. Moreover, a typical weighted proportional-resonant feedforward scheme is suggested to prevent high-frequency resonant units from inducing system instability under a large grid impedance. We finally validate the effectiveness of the proposed approach through experiments.

At the beginning of the 21st century, micro-nano processing technology has developed rapidly, and research on wearable electronic devices has exploded. In particular, flexible thermoelectric materials and thermoelectric generators (TEGs) that have stretchable or foldable properties have been widely studied. Textile-based thermoelectric materials are more suitable for use on the human body than are film or block types of devices, and they are accordingly favoured for wearable smart devices. The design idea of textile thermoelectric materials include the preparation of thermoelectric fibres, textiles, fabric-based films and some novel methods, like using three-dimensional modules to become two-dimensional fabrics by a weaving method, which not to rely something as a base for TE modules. Investigators are thus gaining opportunities to make comfortable and effective fabric TEGs using a wider variety of materials. This article briefly introduces the common methods used to produce textile TEGs. The opportunities and challenges of fabric TEGs are discussed at the end.

In this experiment, the stable output of a dual-frequency laser source is obtained by an acousto-optic modulator due to the Bragg diffraction effect. Furthermore, the non-polarized dual-laser heterodyne interferometer is designed to measure the micro-movement of stacked piezoelectric (PZT) ceramic. This micro-movement can be dynamically determined by comparing the phase difference between the conference beam and measuring beam. The results indicate that the micro-movement of PZT ceramic changes linearly with the driven-voltage in the range of 0–30 V and the sensitivity of movement to voltage is 58.3 nm/V, which is very close to the theoretical value and this laser heterodyne interferometer can be applied for calibrating parameters of PZT ceramic.

Abstract Stainless steels are widely used in hospitals and public transportation vehicles as one of the most common touch surfaces. Retrofitting stainless steel surfaces with an antimicrobial layer can bring potential public health benefits by reducing the ability of inanimate objects, or fomites, to transmit infections. Here, a facile surface conversion reaction between stainless steel and a solution of KMnO4 and CuSO4 is reported, which leads to a conformal and robust oxyhydroxide layer. Microscopy observations show that the layer is amorphous, continuous, and pinhole‐free with a thickness of only 10–15 nm. The coating adheres strongly to stainless steel and can resist rubbing in simulated friction tests, which is attributed to its intermixing with the substrate without forming a sharp interface. Cu ions incorporated into the surface layer can be released into water droplets deposited on the surface and induce antimicrobial activities against bacteria (Pseudomonas aeruginosa PA14) after 30 min of contact.

Thermoelectric material is a kind of functional material that uses the movement of carriers inside a solid to realize the direct mutual conversion of heat and electric energy. It provides a safe, reliable, pollution-free, noise-free, all-solid-state power generation and cooling method and has a wide range of application prospects. Among them, the characteristics of low valence band degeneracy, low effective quality of conduction band, strong phonon non-harmonicity, simple crystal structure and adjustable microstructure have made PbTe-based materials the focus of research in the thermoelectric field. In this review, two latest strategies to improve the thermoelectric properties of PbTe-based materials are discussed, and the challenges for the further development of PbTe-based thermoelectric materials and the prospects for the future are also outlined.

Continued development of lithium-ion batteries is limited by the shortage of Li element. In this situation, the exploration of high-performance sodium-ion batteries is attracting much attention. In this experimental work, Na2/3Ni1/4Mn34O2 film cathode materials were fabricated by excimer laser deposition at different oxygen partial pressures. X-ray diffraction studies and field emission scanning electron microscopy revealed high c-axis orientation and uniform grain distribution, respectively, in the deposited films. Furthermore, after 30 cycles under a current density of 13 mA g−1, the film samples deposited at an oxygen partial pressure of 65 Pa exhibited a high capacity-retention of 91%. The film structure also had a large-current discharge performance, which makes practical applications possible.

Copper chalcogenides have been the subject of extensive research as promising candidates in thermoelectric conversion applications due to their advantageous properties, environmental compatibility, and abundance. The low intrinsic thermal conductivity and high electric conductivity of these materials are born out of the “phonon-liquid electron-crystal” structure between the copper and chalcogens. In this review, strategies for thermoelectric property improvement of copper chalcogenides are discussed. The challenges and the future development of binary copper chalcogenides for further thermoelectric conversion applications are outlined.

Silicon nanoparticles (SiNPs) are the promising materials in the various applications due to their unique properties like large surface area, biocompatibility, stability, excellent optical and electrical properties. Surface, optical and electrical properties are highly dependent on particle size, doping of different materials and so on. Porous structures in silicon nanomaterials not only improve the specific surface area, adsorption, and photoluminescence efficiency but also provide numbers of voids as well as the high surface to volume ratio and enhance the adsorption ability. In this review, we focus on the significance of porous silicon/mesoporous silicon nanoparticles (pSiNPs/mSiNPs) in the applications of energy storage, sensors and bioscience. Silicon as anode material in the lithium-ion batteries (LIBs) faces a huge change in volume during charging/discharging which leads to cracking, electrical contact loss and unstable solid electrolyte interphase. To overcome challenges of Si anode in the LIBs, mSiNPs are the promising candidates with different structures and coating of different materials to enhance electrochemical properties. On the basis of optical properties with tunable wavelength, pSiNPs are catching good results in biosensors and gas sensors. The mSiNPs with different structures and modified surfaces are playing an important role in the detection of biomarkers, drug delivery and diagnosis of cancer and tumors.

Background: The C-reactive protein/lymphocyte ratio (CLR) is a prognostic biomarker of various diseases. However, its significance in acute pancreatitis (AP) remains unknown. The main aim of this study was to investigate the association between the CLR and disease severity in patients with AP. Methods: This cross-sectional study included 476 AP patients [mild acute pancreatitis (MAP), n =176; moderately severe acute pancreatitis (MSAP) and severe acute pancreatitis (SAP), n= 300]. The primary exposure of interest was the baseline CLR. The primary outcome was the incidence of moderate to severe AP. Multivariate logistic regression and restricted cubic spline analyses were performed to evaluate the association between the CLR and the incidence of moderate to severe AP. Receiver operating characteristic (ROC) analysis was conducted to assess the predictive efficacy, sensitivity, and specificity of CLR in predicting the incidence of moderate to severe AP. Results: The mean age of the patients was 44 ± 13.2 years, and 76.5% were male. The distribution of CLR was 31.6 (interquartile range, 4.5, 101.7). Moderate to severe AP occurred in 300 cases (63.0%). After multiple adjustments, CLR was independently associated with the incidence of moderate to severe AP (odds ratio, 1.04; 95% CI: 1.03-1.05; P< 0.001). A nonlinear relationship was found between CLR and the incidence of moderate to severe AP, with a threshold of approximately 45. The effect size and CI below and above the threshold value were 1.061 (1.033-1.089) and 1.014 (0.997-1.031), respectively. The area under the curve (AUC) for CLR was 87.577% (95% CI: 84.443-90.710%) with an optimal cut-off value of 30.835, resulting in a sensitivity of 73.7% and a specificity of 88.6%. Conclusions: There was a nonlinear relationship with a saturation effect between the CLR and the incidence of moderate to severe AP. The CLR measured within 24 h of admission may serve as a promising biomarker for predicting the emergence of moderate to severe AP, thereby providing a more scientifically grounded basis for preventing such cases. Nonetheless, further research is warranted to validate and strengthen these findings. [ABSTRACT FROM AUTHOR]

Aiming at the fact that the rotor winding inter-turn weak faults can hardly be detected due to the strong electromagnetic coupling effect in the excitation system, an interval observer based on current residual is designed. Firstly, the mechanism of the inter-turn short circuit of the rotor winding in the excitation system is modeled under the premise of stable working conditions, and electromagnetic decoupling and system simplification are carried out through Park Transform. An interval observer is designed based on the current residual in the two-phase coordinate system, and the sensitive and stable conditions of the observer is preset. The fault diagnosis process based on the interval observer is formulated, and the observer gain matrix is convexly optimized by linear matrix inequality. The numerical simulation and experimental results show that the inter-turn short circuit weak fault is hardly detected directly through the current signal, but the fault is quickly and accurately diagnosed through the residual internal observer. Compared with the traditional fault diagnosis method based on excitation current, the diagnosis speed and accuracy are greatly improved, and the probability of misdiagnosis also decreases. This method provides a theoretical basis for weak fault identification of excitation systems, and is of great significance for the operation and maintenance of excitation systems. [ABSTRACT FROM AUTHOR]