Recently, sensors that can imitate human skin have received extensive attention. Capacitive sensors have a simple structure, low loss, no temperature drift, and other excellent properties, and can be ...applied in the fields of robotics, human–machine interactions, medical care, and health monitoring. Polymer matrices are commonly employed in flexible capacitive sensors because of their high flexibility. However, their volume is almost unchanged when pressure is applied, and they are inherently viscoelastic. These shortcomings severely lead to high hysteresis and limit the improvement in sensitivity. Therefore, considerable efforts have been applied to improve the sensing performance by designing different microstructures of materials. Herein, two types of sensors based on the applied forces are discussed, including pressure sensors and strain sensors. Currently, five types of microstructures are commonly used in pressure sensors, while four are used in strain sensors. The advantages, disadvantages, and practical values of the different structures are systematically elaborated. Finally, future perspectives of microstructures for capacitive sensors are discussed, with the aim of providing a guide for designing advanced flexible and stretchable capacitive sensors via ingenious human‐made microstructures.
The advantages, disadvantages, and practical applications of several popular microstructures that are widely employed in capacitive sensors are summarized. A microstructured dielectric layer or electrode can improve sensor sensitivity, reduce hysteresis, and endow the rigid electronic device with excellent elastic stretchability, which is an essential part of next‐generation wearable devices and soft robots.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Drawing on the componential model of creativity (Amabile), we examined how shared leadership and a formally appointed leader's transformational leadership jointly cultivate team creativity in two ...studies. We conducted an experiment with a sample of 109 undergraduate students (32 teams) enrolled in a business plan competition (Study 1) and a field survey based on multisource, time‐lagged data collected from 251 full‐time employees working on 64 research and development teams (Study 2). The results from both studies revealed that shared leadership enhanced team members’ individual creative self‐efficacy and individual creativity, which in turn improved team creativity. Moreover, the results from Study 2 showed that a formally appointed leader's use of different transformational leadership behaviors had different impacts on individual and team creativity. Individual‐focused transformational leadership strengthened the positive effect of shared leadership on team members’ average individual creativity, whereas group‐focused transformational leadership facilitated the translation of teams with high average individual creativity into teams with high levels of team creativity. The theoretical and practical implications of the findings are discussed.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Dielectric elastomer actuators (DEAs) with large electrically-actuated strain can build light-weight and flexible non-magnetic motors. However, dielectric elastomers commonly used in the ...field of soft actuation suffer from high stiffness, low strength, and high driving field, severely limiting the DEA’s actuating performance. Here we design a new polyacrylate dielectric elastomer with optimized crosslinking network by rationally employing the difunctional macromolecular crosslinking agent. The proposed elastomer simultaneously possesses desirable modulus (~0.073 MPa), high toughness (elongation ~2400%), low mechanical loss (tan
δ
m
= 0.21@1 Hz, 20 °C), and satisfactory dielectric properties (
$${\varepsilon }_{{{\rm{r}}}$$
ε
r
= 5.75, tan
δ
e
= 0.0019 @1 kHz), and accordingly, large actuation strain (118% @ 70 MV m
−1
), high energy density (0.24 MJ m
−3
@ 70 MV m
−1
), and rapid response (bandwidth above 100 Hz). Compared with VHB
TM
4910, the non-magnetic motor made of our elastomer presents 15 times higher rotation speed. These findings offer a strategy to fabricate high-performance dielectric elastomers for soft actuators.
Polymer‐based dielectrics have received intensive interest from academic community in the field of high‐power energy storage owing to their superior flexibility and fast charge–discharge ability. ...Recently, how to suppress the loss of polymer‐based dielectrics has been increasingly recognized as a critical point to attain a high charge–discharge efficiency in the film capacitors. Some achievements are made in analyzing the source of loss and suppressing loss via Edison's trial and error method. In this review, the significance of suppressing loss in polymer‐based dielectrics is firstly emphasized. Then, different sources of loss are discussed carefully and an in‐depth analysis of the related measurements is presented. Next, recent research results in suppressing loss are summarized and discussed in detail according to different strategies. Finally, the challenges and opportunities in the loss suppression research for the rational design of high‐efficiency polymer‐based dielectrics are proposed.
How to suppress the loss of polymer‐based dielectrics has been increasingly recognized as a critical point to attain a high charge–discharge efficiency in the film capacitors. The theoretical progress, measurement of properties, and development of materials are reviewed. The challenges and opportunities in loss suppression research for the rational design of high‐efficiency polymer‐based dielectrics are proposed.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Interventional hepatic arterial infusion chemotherapy of infusional fluorouracil, leucovorin, and oxaliplatin (HAIC-FO) displayed an encouraging safety profile and antitumor activity in a previous ...phase II trial and a propensity-score-matching study involving patients with locally advanced hepatocellular carcinoma (HCC).
In this open-label, phase III trial, patients with advanced HCC, previously untreated with systemic therapy, were randomly assigned in a 1:1 ratio to receive HAIC-FO or sorafenib. The primary end point was overall survival (OS) in the intention-to-treat population. An exploratory model for predicting the efficacy of HAIC-FO on the basis of genomic sequencing was developed.
Between May 2017 and May 2020, 262 patients were randomly assigned. The median tumor size was 11.2 cm (interquartile range, 8.5-13.7 cm). Macrovascular invasion was present in 65.6%, and the percentage of patients with > 50% tumor volume involvement of the liver and/or Vp-4 portal vein tumor thrombosis was 49.2%. At data cutoff (October 31, 2020), median OS was 13.9 months for HAIC-FO and 8.2 for sorafenib (hazard ratio HR 0.408; 95% CI, 0.301 to 0.552;
< .001). Tumor downstaging occurred in 16 (12.3% of 130) patients receiving HAIC-FO, including 15 receiving curative surgery or ablation, and finally achieving a median OS of 20.8 months, with a 1-year OS rate of 93.8%. In high-risk subpopulations, OS was significantly longer with HAIC-FO than with sorafenib (10.8 months
5.7 months; HR 0.343; 95% CI, 0.219 to 0.538;
< .001). A newly developed 15-mutant-gene prediction model identified 83% of patients with response to HAIC-FO. HAIC-FO responders had longer OS than HAIC-FO nonresponders (19.3 months
10.6 months; HR 0.323; 95% CI, 0.186 to 0.560;
= .002).
HAIC-FO achieved better survival outcomes than sorafenib in advanced HCC, even in association with a high intrahepatic disease burden.
Polymer dielectrics for energy storage applications usually endure high electric field strength. Adjustment of the composition and structure of the dielectric bulk phase to enhance the dielectric ...breakdown strength has been widely studied. However, the effect of electrode-dielectric interface on the breakdown strength has received little attention, which greatly hinders further development in this field. In this work, an all-organic double-layer dielectric film consisting of poly(vinylidene fluoride) (PVDF) as the matrix and polymethyl methacrylate (PMMA) as the organic nano-interlayer was prepared. By adjusting the electrode-dielectric interface, remarkably improved electric breakdown strength (767.05 MV m
−1
) and discharged energy density (19.08 J cm
−3
) were realized concurrently without sacrificing the charge-discharge efficiency. The experimental results and computational simulations reveal that the surface morphology of dielectrics has a great effect on the electric field distribution at the electrode-dielectric interface, and further affects the leakage current and breakdown strength of the dielectric. The PMMA nano-interlayer modifies the surface defects and increases the Young's modulus at the electrode-dielectric interface, leading to the improvement of insulation performance. These findings offer a new perspective to understand the impact of the electrode-dielectric interface on the polymer dielectric breakdown strength. This work provides a novel paradigm for fabricating polymer dielectrics with high breakdown strength for energy storage.
The surface morphology of dielectric films has a great effect on the insulation performance. Remarkably improved capacitive performance is realized by adjusting the electrode-dielectric interface.
Polymer‐based film capacitors with high breakdown strength and excellent flexibility are crucial in the field of advanced electronic devices and electric power systems. Although massive works are ...carried to enhance the energy storage performances, it is still a great challenge to improve the energy density of polymer composites under the premise of large‐scale industrial production. Herein, a general strategy is proposed to improve the intrinsic breakdown strength and energy storage performances by blending core‐shell structured methyl methacrylate‐butadiene‐styrene (MBS) rubber particles into a polymer matrix. Good compatibility and uniform dispersion state of MBS particles are observed in the matrix. Polarizing microscopy images show that blended films exhibit clear reduction of crystalline grains with the addition of MBS particles. Accordingly, an increased breakdown strength of 515 MV m−1 and discharged energy density of 12.33 J cm−3 are observed in poly(vinylidene fluoride‐co‐hexafluoropropylene)‐based composite films. Through comprehensive characterizations, it is believed that the superior energy storage performance of composite films is attributed to decreased crystalline grains, improved mechanical properties, and restriction on carrier motion. These results provide a novel design of dielectric polymers for high breakdown strength and discharged energy density applications.
All‐organic dielectrics are fabricated by blending core‐shell structured methyl methacrylate‐butadiene‐styrene rubber particles and poly(vinylidene fluoride‐co‐hexafluoropropylene) through solution casting method. The blended composite films are found to increase the breakdown strength and discharged energy density of the polymer matrix. The all‐organic films with quick/simple fabrication, improved dielectric, and energy storage performances provide a novel design of dielectrics for energy storage applications.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The incidence of aggressive neuroendocrine prostate cancers (NEPC) related to androgen-deprivation therapy (ADT) is rising. NEPC is still poorly understood, such as its neuroendocrine differentiation ...(NED) and angiogenic phenotypes. Here we reveal that NED and angiogenesis are molecularly connected through EZH2 (enhancer of zeste homolog 2). NED and angiogenesis are both regulated by ADT-activated CREB (cAMP response element-binding protein) that in turn enhances EZH2 activity. We also uncover anti-angiogenic factor TSP1 (thrombospondin-1, THBS1) as a direct target of EZH2 epigenetic repression. TSP1 is downregulated in advanced prostate cancer patient samples and negatively correlates with NE markers and EZH2. Furthermore, castration activates the CREB/EZH2 axis, concordantly affecting TSP1, angiogenesis and NE phenotypes in tumor xenografts. Notably, repressing CREB inhibits the CREB/EZH2 axis, tumor growth, NED, and angiogenesis in vivo. Taken together, we elucidate a new critical pathway, consisting of CREB/EZH2/TSP1, underlying ADT-enhanced NED and angiogenesis during prostate cancer progression.
With the development of advanced electronic devices and electric power systems, polymer-based dielectric film capacitors with high energy storage capability have become particularly important. ...Compared with polymer nanocomposites with widespread attention, all-organic polymers are fundamental and have been proven to be more effective choices in the process of scalable, continuous, and large-scale industrial production, leading to many dielectric and energy storage applications. In the past decade, efforts have intensified in this field with great progress in newly discovered dielectric polymers, fundamental production technologies, and extension toward emerging computational strategies. This review summarizes the recent progress in the field of energy storage based on conventional as well as heat-resistant all-organic polymer materials with the focus on strategies to enhance the dielectric properties and energy storage performances. The key parameters of all-organic polymers, such as dielectric constant, dielectric loss, breakdown strength, energy density, and charge–discharge efficiency, have been thoroughly studied. In addition, the applications of computer-aided calculation including density functional theory, machine learning, and materials genome in rational design and performance prediction of polymer dielectrics are reviewed in detail. Based on a comprehensive understanding of recent developments, guidelines and prospects for the future development of all-organic polymer materials with dielectric and energy storage applications are proposed.
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IJS, KILJ, NUK, PNG, UL, UM
From the perspective of the integrative model of organizational trust, this study proposes a multi-level model for whether, how, and when differentiated empowering leadership influences followers' ...trust in leaders and their work outcomes. Drawing on a sample of 372 followers from 97 teams in China, it was found that the negative effect of differentiated empowering leadership on followers' trust in leaders became salient when followers' Chinese traditionality was low. Moreover, followers' trust in leaders mediated the effect of differentiated empowering leadership and Chinese traditionality on followers' in-role performance, extra-role performance, and counterproductive work behaviors toward the organization. These findings have implications for managerial theory and practice in the domains of trust and differentiated empowering leadership.
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