Leader humor: A double-edged sword.

Leader humor has been considered one of the most promising yet least understood influential tools by psychologists and management scholars. Here, I review the growing body of research on leader humor and its implications for followers and organizations, showing that despite being theorized as a positive leadership tool, leader humor can function as a double-edged sword in bringing both beneficial and detrimental outcomes for followers and organizations.In the process, I identify six distinct mechanisms (three positive and three negative) through which leader humor affects followers. In a way, leader humor can be used to reduce or increase the social and psychological distance between leaders and followers. I also discuss the directions for future research on leader humor.

Highly Biocompatible Polyester-Based Piezoelectric Elastomer with Antitumor and Antibacterial Activity for Ultrasound-Enhanced Piezoelectric Therapy.

Currently, the use of piezoelectric materials to provide sustainable and noninvasive bioelectric stimulation to eradicate tumor cells and accelerate wound healing has raised wide attention. The development of a multifunctional piezoelectric elastomer with the ability to perform in situ tumor therapy as well as wound repair is of paramount importance. However, current piezoelectric materials have a large elastic modulus and limited stretchability, making it difficult to match with the dynamic curvature changes of the wound. Therefore, by copolymerizing lactic acid, butanediol, sebacic acid, and itaconic acid to develop a piezoelectric elastomer (PLBSIE), we construct a new ultrasound-activated PLBSIE-based tumor/wound unified therapeutic platform. Excitedly, it showed outstanding piezoelectric performance and high stretchability, and the separated carrier could react with water to generate highly cytotoxic reactive oxygen species (ROS), contributing to effectively killing tumor cells and eliminating bacteria through piezoelectric therapy. In addition, ultrasound-triggered piezoelectric effects could promote the migration and differentiation of wound-healing-related cells, thus accelerating wound healing. Herein, such a piezoelectric elastomer exerted a critical role in postoperative tumor-induced wound therapy and healing with the merits of possessing multifunctional abilities. Taken together, the developed ultrasound-activated PLBSIE will offer a comprehensive treatment for postoperative osteosarcoma therapy.

Hierarchical Fusion Network with Enhanced Knowledge and Contrastive Learning for Multimodal Aspect-Based Sentiment Analysis on Social Media.

Aspect-based sentiment analysis (ABSA) is a task of fine-grained sentiment analysis that aims to determine the sentiment of a given target. With the increased prevalence of smart devices and social media, diverse data modalities have become more abundant. This fuels interest in multimodal ABSA (MABSA). However, most existing methods for MABSA prioritize analyzing the relationship between aspect-text and aspect-image, overlooking the semantic gap between text and image representations. Moreover, they neglect the rich information in external knowledge, e.g., image captions. To address these limitations, in this paper, we propose a novel hierarchical framework for MABSA, known as HF-EKCL, which also offers perspectives on sensor development within the context of sentiment analysis. Specifically, we generate captions for images to supplement the textual and visual features. The multi-head cross-attention mechanism and graph attention neural network are utilized to capture the interactions between modalities. This enables the construction of multi-level aspect fusion features that incorporate element-level and structure-level information. Furthermore, for this paper, we integrated modality-based and label-based contrastive learning methods into our framework, making the model learn shared features that are relevant to the sentiment of corresponding words in multimodal data. The results, based on two Twitter datasets, demonstrate the effectiveness of our proposed model.

The mediating effects of dysfunctional attitudes and moderating effect of sex between stressful life events and depressive symptoms among Chinese college students.

Stressful life events (SLEs) closely correlates with depressive symptoms. Although vulnerability-stress model suggests SLEs interacted with dysfunctional attitudes (DA) to predict depression, the mediation role of DA is poorly understood. Therefore, this study intended to investigate the mediating role of DA and the moderating role of sex between SLEs and self-reported depression. A cross-sectional survey was conducted with a sample of 7769 Chinese college students. Participants were assessed in terms of self-reported SLEs, DA and depression variables. Results showed that there were significant sex differences in both SLE and DA. DA mediated the association between SLE and self-reported depression. The moderated mediation model analysis showed that the interaction of SLEs and sex significantly predicted DA in mediator variable model and self-reported depression in dependent variable model. Results indicated that DA partially mediated the association between SLEs and self-reported depression, and sex moderates the association between SLEs and both DA and self-reported depression, which females have bigger changes of DA and depressive symptoms across low and high levels of SLEs than males.

Force-Triggered Atropisomerization of a Parallel Diarylethene to Its Antiparallel Diastereomers.

This paper describes a mechanical approach to inducing the atropisomerization of a parallel diarylethene into its antiparallel diastereomers exhibiting distinct chemical reactivity. A congested parallel diarylethene mechanophore in the (Ra,Sa)-configuration with mirror symmetry is atropisomerized to its antiparallel diastereomers with C2 symmetry under ultrasound-induced force field. The resulting stereochemistry-converted material gains symmetry-allowed reactivity toward conrotatory photocyclization.

Self-Healing Binder for High-Voltage Batteries.

Lithium-ion batteries are core components of flexible electronic devices. However, deformation types, such as impinging, bending, stretching, folding, and twisting, can cause internal cracks and, eventually, damage these batteries. The cracks separate the active particles from the conductive particles and the binder, as well as the electrode from the collector. Self-healing binders can alleviate this mechanical damage and improve the stress response of active material particles during high rates of charging and discharging of these batteries and the operation at a high voltage, thereby enhancing their cycle performance. In the present study, a thermoplastic intrinsic self-healing polymer (TISP) binder is proposed. The TISP is obtained by polymerization of butanediol (2,3-BDO), propylene glycol (1,3-PDO), succinic acid (SuA), sebacic acid (SeA), and iconic acid (IA). The hydroxyl and ester groups in its structure can form diverse bonds including the hydrogen and ion-dipole with active particles and the current collector, thereby producing elevated adhesion. Its properties, including a low glass transition temperature (-60 °C), amorphous structure, and low cross-link density, improve the mobility of polymer chains at 40 °C, and this facilitates structural recovery and the maintenance of strong adhesions. Owing to its higher occupied molecular orbital (HOMO) level than the electrolyte solvent, the TISP is likely oxidized before the main component of the electrolyte during charging. This decomposition produces a chemical passivation interphase on the cathode which reduces side reactions of LiCoO2 and the electrolyte under high-voltage conditions. Tests reveal that a LiCoO2 electrode battery using the TISP as a binder retains 162.4 mAh g-1 after 349 cycles at 4.5 V, and this represents an 86.5% capacity retention. In addition, heating (40 °C, 1 h) of a scratch-damaged electrode can recover a specific capacity of 156.6 mAh g-1 after 349 cycles at 4.5 V. Relative to a battery without any mechanical scratch, this capacity recovery represents approximately 96%, and this demonstrates the importance of the TISP to the high-voltage damaged electrode.

3D-Printed Bionic Ear for Sound Identification and Localization Based on In Situ Polling of PVDF-TrFE Film.

Bionic acoustic sensors are an indispensable part to realize interactions between humans and robotics. In this work, a PVDF-TrFE sensor array with multiple active pixels combined with a 3D-printed bionic ear model is prepared, which can accurately detect sounds with different frequencies and locate the sound source from different directions. The PVDF-TrFE sensor array can clearly identify the sound within 25 cm, and the error between the accepted sound frequency and the original input frequency is less than 0.001%. Through the algorithm analysis of the input signal, the location of the sound source can be immediately analyzed. Compared with other acoustic sensors, this sensor has the advantages of being self-powered, small size, and high flexibility, which holds great potential for bionic applications.

Incorporation of a Tethered Alcohol Enables Efficient Mechanically Triggered Release in Aprotic Environments.

Polymers that release small molecules in response to mechanical force are promising for a wide variety of applications. While offering a general platform for mechanically triggered release, previous mechanophore designs based on masked 2-furylcarbinol derivatives are limited to polar protic solvent environments for efficient release of the chemical payload. Here, we report a masked furfuryl carbonate mechanophore incorporating a tethered primary alcohol that enables efficient release of a hydroxycoumarin cargo in the absence of a protic solvent. Density functional calculations also implicate an intramolecular hydrogen bonding interaction between the tethered alcohol and the carbonyl oxygen of the carbonate that reduces the activation barrier for carbonate fragmentation leading to molecular release. This new mechanophore design expands the generality of the masked 2-furylcarbinol platform for mechanically triggered release, enabling the implementation of this strategy in a wider range of chemical environments.

Harnessing the Power of Force: Development of Mechanophores for Molecular Release.

Polymers that release small molecules in response to mechanical force are promising materials for a variety of applications ranging from sensing and catalysis to targeted drug delivery. Within the rapidly growing field of polymer mechanochemistry, stress-sensitive molecules known as mechanophores are particularly attractive for enabling the release of covalently bound payloads with excellent selectivity and control. Here, we review recent progress in the development of mechanophore-based molecular release platforms and provide an optimistic, yet critical perspective on the fundamental and technological advancements that are still required for this promising research area to achieve significant impact.

5-Aryloxy substitution enables efficient mechanically triggered release from a synthetically accessible masked 2-furylcarbinol mechanophore.

Polymers that release small molecules in response to mechanical force are attractive materials for a wide variety of applications. Here, we report a new mechanophore platform based on a masked 2-furylcarbinol derivative that incorporates a 5-aryloxy group, which serves as both an electron-rich substituent to accelerate molecular release and the position of polymer attachment proximal to the furan-maleimide junction. The mechanophore is readily synthesized and efficiently releases both phenol and arylamine payloads following mechanical activation.

Mechanically Triggered Release of Functionally Diverse Molecular Payloads from Masked 2-Furylcarbinol Derivatives.

Polymers that release functional small molecules in response to mechanical force are appealing targets for drug delivery, sensing, catalysis, and many other applications. Mechanically sensitive molecules called mechanophores are uniquely suited to enable molecular release with excellent selectivity and control, but mechanophore designs capable of releasing cargo with diverse chemical functionality are limited. Here, we describe a general and highly modular mechanophore platform based on masked 2-furylcarbinol derivatives that spontaneously decompose under mild conditions upon liberation via a mechanically triggered reaction, resulting in the release of a covalently installed molecular payload. We identify key structure-property relationships for the reactivity of 2-furylcarbinol derivatives that enable the mechanically triggered release of functionally diverse molecular cargo with release kinetics being tunable over several orders of magnitude. In particular, the incorporation of an electron-donating phenoxy group on the furan ring in combination with an α-methyl substituent dramatically lowers the activation barrier for fragmentation, providing a highly active substrate for molecular release. Moreover, we find that phenoxy substitution enhances the thermal stability of the mechanophore without adversely affecting its mechanochemical reactivity. The generality and efficacy of this molecular design platform are demonstrated using ultrasound-induced mechanical force to trigger the efficient release of a broad scope of cargo molecules, including those bearing alcohol, phenol, alkylamine, arylamine, carboxylic acid, and sulfonic acid functional groups.

Associations between feelings/behaviors during COVID-19 pandemic lockdown and depression/anxiety after lockdown in a sample of Chinese children and adolescents.

BACKGROUND: Children and adolescents may be more susceptible to mental disorders due to COVID-19 pandemic than adults. This study aimed to identify correlated factors for depression/anxiety among children and adolescents after COVID-19 pandemic lockdown. METHODS: An online survey by cluster sampling was conducted after lockdown in 5175 Chinese children and adolescents with informed consents from their parents. The 9-item Patient Health Questionnaire and the 7-item Generalized Anxiety Disorder scales with 10-point cutoff were used to measure depression and anxiety, separately. Stepwise logistic regression was conducted. Stata 15.1 Version was used. RESULTS: 12.33% and 6.26% of all participants reported depression and anxiety after lockdown, separately. Suicidal ideation, quarreling with parents, insomnia, difficulty in concentrating during online learning, and anxious and depressed mood during lockdown were positively associated with depression and anxiety after lockdown. Missing teachers was negatively associated with both depression and anxiety. Living in urban and not living with parents were positively associated with depression. LIMITATIONS: The past history and familial history of mental disorders have not been collected. The recall biases for collecting self-reporting information might exist, and the causal inferences cannot be drawn. CONCLUSIONS: The prevalence of depression and anxiety in children and adolescents might decline a bit after lockdown but is still at a high level after lockdown. Gatekeepers should pay more attention to modifiable factors of psychological well-being in children and adolescents, including family and school contexts and even feelings and behaviors during COVID-19 pandemic lockdown.

Effects of Annealing on Electrochemical Properties of Solvothermally Synthesized Cu2SnS3 Anode Nanomaterials.

Cu2SnS3, as a modified material for high-capacity tin-based anodes, has great potential for lithium-ion battery applications. The solvothermal method is simple, convenient, cost-effective, and easy to scale up, and has thus been widely used for the preparation of nanocrystals. In this work, Cu2SnS3 nanoparticles were prepared by the solvothermal method. The effects of high-temperature annealing on the morphology, crystal structure, and electrochemical performance of a Cu2SnS3 nano-anode were studied. The experimental results indicate that high-temperature annealing improves the electrochemical performance of Cu2SnS3, resulting in higher initial coulombic efficiency and improved cycling and rate characteristics compared with those of the as-prepared sample.

Mechanically Triggered Small Molecule Release from a Masked Furfuryl Carbonate.

Stimuli-responsive polymers that release small molecules under mechanical stress are appealing targets for applications ranging from drug delivery to sensing. Here, we describe a modular mechanophore design platform for molecular release via a mechanically triggered cascade reaction. Mechanochemical activation of a furan-maleimide Diels-Alder adduct reveals a latent furfuryl carbonate that subsequently decomposes under mild conditions to release a covalently bound cargo molecule. The computationally guided design of a reactive secondary furfuryl carbonate enables the decomposition and release to proceed quickly at room temperature after unmasking via mechanical force. This general strategy is demonstrated using ultrasound-induced mechanical activation to release a fluorogenic coumarin payload from a polymer incorporating a chain-centered mechanophore.

Mechanochemical Regulation of a Photochemical Reaction.

We introduce the concept of mechanochemically gated photoswitching. Mechanical regulation of a photochemical reaction is exemplified using a newly designed mechanophore based on a cyclopentadiene-maleimide Diels-Alder adduct. Ultrasound-induced mechanical activation of the photochemically inert mechanophore in polymers generates a diarylethene photoswitch via a retro-[4 + 2] cycloaddition reaction that photoisomerizes between colorless and colored states upon exposure to UV and visible light. Control experiments demonstrate the thermal stability of the cyclopentadiene-maleimide adduct and confirm the mechanical origin of the "unlocked" photochromic reactivity. This technology holds promise for applications such as lithography and stress-sensing, enabling the mechanical history of polymeric materials to be recorded and read on-demand.

UV and NIR-Responsive Layer-by-Layer Films Containing 6-Bromo-7-hydroxycoumarin Photolabile Groups.

This paper describes polyelectrolyte multilayer films prepared by the layer-by-layer (LbL) technique capable of undergoing dissolution upon exposure to either ultraviolet or near-infrared light. Film dissolution is driven by photochemical deprotection of a random methacrylic copolymer with two types of side chains: (i) 6-bromo-7-hydroxycoumarinyl esters, photocleavable groups that are known to have substantial two-photon photolysis cross sections, and (ii) cationic residues from the commercially available monomer N,N-dimethylaminoethyl methacrylate (DMAEMA). In addition, the dependence of stability of both unirradiated and irradiated films on pH provides experimental evidence for the necessity of disrupting both ion-pairing and hydrophobic interactions between polyelectrolytes to realize film dissolution. This work therefore provides both new fundamental insight regarding photolabile LbL films and expands their applied capabilities to nonlinear photochemical processes.

Self-Cleaning Membranes from Comb-Shaped Copolymers with Photoresponsive Side Groups.

In this study, we present a novel self-cleaning, photoresponsive membrane that is capable of removing predeposited foulant layers upon changes in surface morphology in response to UV or visible light irradiation while maintaining stable pore size and water permeance. These membranes were prepared by creating thin film composite (TFC) membranes by coating a porous support membrane with a thin layer of novel comb-shaped graft copolymers at two side-chain lengths featuring polyacrylonitrile (PAN) backbones and photoreactive side chains, synthesized by atom transfer radical polymerization (ATRP). Photoregulated control over membrane properties is attained through a light-induced transition, where the side chains switch between a hydrophobic spiropyran (SP) state and a zwitterionic, hydrophilic merocyanine (MC) state. The light-induced switch between the SP and MC forms changes surface hydrophilicity and causes morphological changes on the membrane surface as evidenced by atomic force microscopy (AFM). Before any phototreatment, the as-coated membrane surface comprises mostly hydrophobic SP groups that allow the adsorption of organic solutes such as proteins the membrane surface, reducing flow rate. Once exposed to UV light, conversion of the SP groups to hydrophilic MC groups leads to the release of adsorbed molecules and the full recovery of the initial water flux. A fouled membrane in the more hydrophilic MC form is also capable of self-cleaning upon conversion to the less hydrophilic SP form by visible light irradiation. The self-cleaning behavior observed for this system, where the surface became less hydrophilic but also experienced a morphological change, demonstrates a novel mechanism that has a mechanical component in addition to the changes in hydrophilicity. It is also the first report, to our knowledge, of self-cleaning performance accompanied by a decrease in hydrophilicity.

Preparation and Properties of Novel Thermoplastic Vulcanizate Based on Bio-Based Polyester/Polylactic Acid, and Its Application in 3D Printing.

Thermoplastic vulcanizate (TPV) combines the high elasticity of elastomers and excellent processability of thermoplastics. Novel bio-based TPV based on poly (lactide) (PLA) and poly (1,4-butanediol/2,3-butanediol/succinate/itaconic acid) (PBBSI) were prepared in this research. PBBSI copolyesters were synthesized by melting polycondensation, and the molecular weights, chemical structures and compositions of the copolyesters were characterized by GPC, NMR and FTIR. Bio-based 2,3-butanediol was successfully incorporated to depress the crystallization behavior of the PBBSI copolyester. With an increase of 2,3-butanediol content, the PBBSI copolyester transformed from a rigid plastic to a soft elastomer. Furthermore, the obtained TPV has good elasticity and rheological properties, which means it can be applied as a 3D-printing material.

Triggered Release of Encapsulated Cargo from Photoresponsive Polyelectrolyte Nanocomplexes.

Combining the numerous advantages of using light as a stimulus, simple free radical random copolymerization, and the easy, all-aqueous preparation of polyelectrolyte complexes (PECs), we prepared photolabile PEC nanoparticles and demonstrated their rapid degradation under UV light. As a proof of concept demonstration, the dye Nile Red was encapsulated in the PECs and successfully released into the surrounding solution as the polyelectrolyte nanocomplex carriers dissolved upon light irradiation.

Stimuli-Responsive Free-Standing Layer-By-Layer Films.

Free-standing, stimuli-responsive polyelectrolyte multilayer films enabled by light-induced degradation of sacrificial compartments are introduced. Two examples are described: i) a triple responsive film that uses light, redox, and pH for different functions, and ii) different wavelengths of light for different functions. This approach to multiresponsive materials offers simple design and chemical synthesis while enabling different stimuli to perform separate functions in the same material.