Hierarchically Superstructured Anisotropic Carbon Particles by Multiscale Assembly Driven by Spinodal Decomposition.

Hierarchical superstructures have novel shape-dependent properties, but well-defined anisotropic carbon superstructures with controllable size, shape, and building block dimensionality have rarely been accomplished thus far. Here, a hierarchical assembly technique is presented that uses spinodal decomposition (SD) to synthesize anisotropic oblate particles of mesoporous carbon superstructure (o-MCS) with nanorod arrays by integrating block-copolymer (BCP) self-assembly and polymer-polymer interface behaviors in binary blends. The interaction of major and minor phases in binary polymer blends leads to the formation of an anisotropic oblate particle, and the BCP-rich phase enables ordered packing and unidirectional alignment of carbon nanorods. Consequently, this approach enables precise control over particles' size, shape, and over the dimensionality of their components. Exploiting this functional superstructure, o-MCS are used as an anode material in potassium-ion batteries, and achieve a notable specific capacity of 156 mA h g-1 at a current density of 2 A g-1, and long-term stability for 3000 cycles. This work presents a significant advancement in the field of hierarchical superstructures, providing a promising strategy for the design and synthesis of anisotropic carbon materials with controlled properties, offering promising applications in energy storage and beyond.

Spinodal Decomposition-Driven Structural Hierarchy of Mesoporous Inorganic Materials for Energy Applications.

ConspectusMesoporous inorganic materials (MIMs) directed by block copolymers (BCPs) have attracted tremendous attention due to their high surface area, large pore volume, and tunable pore size. The structural hierarchy of inorganic materials with designed meso- and macrostructures combines the benefits of mesoporosity and tailored macrostructures in which macropores have increased ion/mass transfer and large capacity to carry guest material and have a macroscale particle morphology that permits close packing and a low surface energy. Existing methods for hierarchically structured MIMs require complicated multistep procedures including preparation of sacrificial macrotemplates (e.g., foams and colloidal spheres). Despite considerable efforts to control the macrostructures of mesoporous materials, major challenges remain in the formation of a structural hierarchy with ordered mesoporosity.In polymer science, spinodal decomposition (SD) is a physical phenomenon that spontaneously produces a wide variety of macroscale heterostructures from interconnected networks to isolated droplets. Exploitation of SD is a promising method to achieve precise control of the macrostructure (e.g., macropore, particle morphology) and mesostructure (e.g., pore size and structure, composition) of inorganic materials. However, this approach for tailoring the structural hierarchy of MIMs is unexplored due to the lack of effective systems that can control the complex thermodynamic interactions of inorganic precursor/polymer blends and the phase-separation kinetics.In this Account, we present our recent research progress on the development of synthesis systems that combine unique SD behaviors and BCP self-assembly in polymer blends. To generate macropores in MIMs, we have exploited interconnected macrostructures of SD induced by designed quench conditions of multicomponent blends containing BCP. These strategies enable control of the size of the macropores of the nanostructures independently and can be extended to various compositions (e.g., carbon, SiO2, TiO2, WO3, TiNb2O7, TiN). We also control the macroscopic morphology of the MIMs into spherical particles (e.g., solid and hollow mesoporous spheres) by using SD induced by increasing the mixing entropy penalty of polymer blends that consist BCP, homopolymer(s), and inorganic precursors. Furthermore, interfacial tension between polymers determines the macroscopic morphology of MIMs, from isotropic to anisotropic mesoporous particles (e.g., oblate, bowl, 2D nanosheet). The interfacial states of the homopolymer determine the pore orientation and particle morphology of BCP-directed MIMs.We also highlight the application of the hierarchically structured MIMs in energy storage devices. Generated macropores facilitate ion/mass transfer in lithium-ion batteries and stable accommodation of a large amount of sulfur in lithium-sulfur batteries. Designed morphologies of MIMs are beneficial to achieve high packing density as electrode materials in potassium-ion batteries and thereby achieve high volumetric capacities.Recent advances in SD-driven synthesis for the structural hierarchy of MIMs will inspire how polymer science can be used as a platform for preparing the designed inorganic materials. Additionally, broadening the polymer and composition repertoire will guide in novel frontiers in the design and applications of MIMs in various fields.

Preference for utilitarian or hedonic value options during a pandemic crisis: The moderation effects of childhood socioeconomic status and sensation-seeking.

This research investigated hospitality consumers' relative preferences for utilitarian or hedonic value under COVID-19 pandemic conditions. A series of four experiments and one secondary data analysis showed that the salience of the infectious disease threat increased consumers' preferences for hospitality options that provide relatively more utilitarian than hedonic value. Additionally, we identified two individual differences (i.e., childhood socioeconomic status (SES) & sensation-seeking) that moderated the effect of the infectious disease threat on the preferred hospitality consumption value. Specifically, the higher the childhood SES, the higher was the preference for the utilitarian value option, and the lower the level of sensation-seeking, the greater was the preference for the utilitarian value option. This research extends our understanding of the influence of the infectious disease threat on preference changes in hospitality decisions.

Cellular Expression and Functional Roles of All 26 Neurotransmitter GPCRs in the C. elegans Egg-Laying Circuit.

Maps of the synapses made and neurotransmitters released by all neurons in model systems, such as Caenorhabditis elegans have left still unresolved how neural circuits integrate and respond to neurotransmitter signals. Using the egg-laying circuit of C. elegans as a model, we mapped which cells express each of the 26 neurotransmitter GPCRs of this organism and also genetically analyzed the functions of all 26 GPCRs. We found that individual neurons express many distinct receptors, epithelial cells often express neurotransmitter receptors, and receptors are often positioned to receive extrasynaptic signals. Receptor knockouts reveal few egg-laying defects under standard laboratory conditions, suggesting that the receptors function redundantly or regulate egg-laying only in specific conditions; however, increasing receptor signaling through overexpression more efficiently reveals receptor functions. This map of neurotransmitter GPCR expression and function in the egg-laying circuit provides a model for understanding GPCR signaling in other neural circuits.SIGNIFICANCE STATEMENT Neurotransmitters signal through GPCRs to modulate activity of neurons, and changes in such signaling can underlie conditions such as depression and Parkinson's disease. To determine how neurotransmitter GPCRs together help regulate function of a neural circuit, we analyzed the simple egg-laying circuit in the model organism C. elegans We identified all the cells that express every neurotransmitter GPCR and genetically analyzed how each GPCR affects the behavior the circuit produces. We found that many neurotransmitter GPCRs are expressed in each neuron, that neurons also appear to use these receptors to communicate with other cell types, and that GPCRs appear to often act redundantly or only under specific conditions to regulate circuit function.

Polymer Interface-Dependent Morphological Transition toward Two-Dimensional Porous Inorganic Nanocoins as an Ultrathin Multifunctional Layer for Stable Lithium-Sulfur Batteries.

Two-dimensional (2D) porous inorganic nanomaterials have intriguing properties as a result of dimensional features and high porosity, but controlled production of circular 2D shapes is still challenging. Here, we designed a simple approach to produce 2D porous inorganic nanocoins (NCs) by integrating block copolymer (BCP) self-assembly and orientation control of microdomains at polymer-polymer interfaces. Multicomponent blends containing BCP and homopoly(methyl methacrylate) (hPMMA) are designed to undergo macrophase separation followed by microphase separation. The balanced interfacial compatibility of BCP allows perpendicularly oriented lamellar-assembly at the interfaces between BCP-rich phase and hPMMA matrix. Disassembly of lamellar structures and calcination yield ultrathin 2D inorganic NCs that are perforated by micropores. This approach enables control of the thickness, size, and chemical composition of the NCs. 2D porous and acidic aluminosilicate NC (AS-NC) is used to fabricate an ultrathin and lightweight functional separator for lithium-sulfur batteries. The AS-NC layer acts as an ionic sieve to selectively block lithium polysulfides. Abundant acid sites chemically capture polysulfides, and micropores physically exclude them, so sulfur utilization and cycle stability are increased.

Impact of the COVID-19 pandemic on travelers' preference for crowded versus non-crowded options.

Crowding is a critical determinant of consumers' satisfaction with and preferences for different shopping and travel situations. When considering a selection of travel and hospitality options, travelers are influenced by perceived crowding. This research examined how the current health crisis (i.e., the COVID-19 pandemic) affects travelers' preferences for crowded and non-crowded options. Specifically, we predicted that travelers would have a diminished preference for crowded (vs. non-crowded) travel and hospitality options when the ongoing pandemic is salient. We demonstrated that the primary effect of the salience of the threat was persistent across different travel categories and contexts. We also found that travelers with high levels of sensation seeking and a high need for uniqueness show the opposite pattern, suggesting a possible recovery strategy from the pandemic. Five experimental studies provide several theoretical and managerial implications for travel and hospitality business marketers.

Preference for robot service or human service in hotels? Impacts of the COVID-19 pandemic.

Robots and artificial intelligence (AI) technologies are becoming more prominent in the tourism industry. Nowadays, consumers are faced with multiple options involving both human and robot interactions. A series of experimental studies were implemented. Four experiments demonstrated that consumers had a more positive attitude toward robot-staffed (vs. human-staffed) hotels when COVID-19 was salient. The results were different from previous studies, which were conducted before the COVID-19 pandemic. Since the moderating role of perceived threat in consumers' preference for robot-staffed hotels was significant, the respondents' preference was attributed to the global health crisis. This research provides a number of theoretical and managerial implications by improving the understanding of technology acceptance during a health crisis.

How the COVID-19 pandemic affected hotel Employee stress: Employee perceptions of occupational stressors and their consequences.

This study sought to examine the impacts of the global coronavirus pandemic on hotel employees' perceptions of occupational stressors and their consequences. Paired t-tests and structural equation modeling were applied to examine the responses of 758 hotel employees in the United States. The findings showed that occupational stressors after the outbreak of the pandemic consisted of three domains: traditional hotel-work stressors, unstable and more demanding hotel-work-environment stressors, and unethical hotel-labor-practices-borne stressors. The impacts of these stressors differed from the hypothesis that traditional hotel-work stressors positively affect job satisfaction and organizational commitment. The findings showed that job satisfaction and organizational commitment significantly explained job performance, subjective well-being, and prosocial behavior, but they did not significantly influence turnover intention. Hotel employees' pre-pandemic perceptions of occupational stressors and their consequences also differed significantly from their perceptions after the pandemic had broken out.

Polymer Interfacial Self-Assembly Guided Two-Dimensional Engineering of Hierarchically Porous Carbon Nanosheets.

Two-dimensional (2D) carbon nanosheets with micro- and/or mesopores have attracted great attention due to unique physical and chemical properties, but well-defined nanoporous carbon nanosheets with tunable thickness and pore size have been rarely realized. Here, we develop a polymer-polymer interfacial self-assembly strategy to achieve hierarchically porous carbon nanosheets (HNCNSs) by integrating the migration behaviors of immiscible ternary polymers with block copolymer (BCP)-directed self-assembly. The balanced interfacial compatibility of BCP allows the migration of a BCP-rich phase to the interface between two immiscible homopolymer major phases (i.e., homopoly(methyl methacrylate) and homopolystyrene), where the BCP-rich phase spreads thinly to a thickness of a few nanometers to decrease the interfacial tension. BCP-directed coassembly with organic-inorganic precursors constructs an ordered mesostructure. Carbonization and chemical etching yield ultrathin HNCNSs with hierarchical micropores and mesopores. This approach enables facile control over the thickness (5.6-75 nm) and mesopore size (25-46 nm). As an anode material in a potassium ion battery, HNCNSs show high specific capacity (178 mA h g-1 at a current density of 1 A g-1) with excellent long-term stability (2000 cycles), by exploiting the advantages of the hierarchical pores and 2D nanosheet morphology (efficient ion/electron diffusion) and of the large interlayer spacing (stable ion insertion).

Evolutionary Conservation of a GPCR-Independent Mechanism of Trimeric G Protein Activation.

Trimeric G protein signaling is a fundamental mechanism of cellular communication in eukaryotes. The core of this mechanism consists of activation of G proteins by the guanine-nucleotide exchange factor (GEF) activity of G protein coupled receptors. However, the duration and amplitude of G protein-mediated signaling are controlled by a complex network of accessory proteins that appeared and diversified during evolution. Among them, nonreceptor proteins with GEF activity are the least characterized. We recently found that proteins of the ccdc88 family possess a Gα-binding and activating (GBA) motif that confers GEF activity and regulates mammalian cell behavior. A sequence similarity-based search revealed that ccdc88 genes are highly conserved across metazoa but the GBA motif is absent in most invertebrates. This prompted us to investigate whether the GBA motif is present in other nonreceptor proteins in invertebrates. An unbiased bioinformatics search in Caenorhabditis elegans identified GBAS-1 (GBA and SPK domain containing-1) as a GBA motif-containing protein with homologs only in closely related worm species. We demonstrate that GBAS-1 has GEF activity for the nematode G protein GOA-1 and that the two proteins are coexpressed in many cells of living worms. Furthermore, we show that GBAS-1 can activate mammalian Gα-subunits and provide structural insights into the evolutionarily conserved determinants of the GBA-G protein interface. These results demonstrate that the GBA motif is a functional GEF module conserved among highly divergent proteins across evolution, indicating that the GBA-Gα binding mode is strongly constrained under selective pressure to mediate receptor-independent G protein activation in metazoans.

Direct access to hierarchically porous inorganic oxide materials with three-dimensionally interconnected networks.

Hierarchically porous oxide materials have immense potential for applications in catalysis, separation, and energy devices, but the synthesis of these materials is hampered by the need to use multiple templates and the associated complicated steps and uncontrollable mixing behavior. Here we report a simple one-pot strategy for the synthesis of inorganic oxide materials with multiscale porosity. The inorganic precursor and block copolymer are coassembled into an ordered mesostructure (microphase separation), while the in situ-polymerized organic precursor forms organic-rich macrodomains (macrophase separation) around which the mesostructure grows. Calcination generates hierarchical meso/macroporous SiO2 and TiO2 with three-dimensionally interconnected pore networks. The continuous 3D macrostructures were clearly visualized by nanoscale X-ray computed tomography. The resulting TiO2 was used as the anode in a lithium ion battery and showed excellent rate capability compared with mesoporous TiO2. This work is of particular importance because it (i) expands the base of BCP self-assembly from mesostructures to complex porous structures, (ii) shows that the interplay of micro- and macrophase separation can be fully exploited for the design of hierarchically porous inorganic materials, and therefore (iii) provides strategies for researchers in materials science and polymer science.

Anisotropic lens-shaped mesoporous carbon from interfacially perpendicular self-assembly for potassium-ion batteries.

Anisotropic lens-shaped nitrogen-doped carbon (Lens-NMC) with unidirectionally aligned mesopores was achieved via perpendicular block copolymer self-assembly at the polymer interface. Lens-NMC is applied as a potassium-ion battery anode material as a next-generation battery system.

Control of oocyte growth and meiotic maturation in Caenorhabditis elegans.

In sexually reproducing animals, oocytes arrest at diplotene or diakinesis and resume meiosis (meiotic maturation) in response to hormones. Chromosome segregation errors in female meiosis I are the leading cause of human birth defects, and age-related changes in the hormonal environment of the ovary are a suggested cause. Caenorhabditis elegans is emerging as a genetic paradigm for studying hormonal control of meiotic maturation. The meiotic maturation processes in C. elegans and mammals share a number of biological and molecular similarities. Major sperm protein (MSP) and luteinizing hormone (LH), though unrelated in sequence, both trigger meiotic resumption using somatic Gα(s)-adenylate cyclase pathways and soma-germline gap-junctional communication. At a molecular level, the oocyte responses apparently involve the control of conserved protein kinase pathways and post-transcriptional gene regulation in the oocyte. At a cellular level, the responses include cortical cytoskeletal rearrangement, nuclear envelope breakdown, assembly of the acentriolar meiotic spindle, chromosome segregation, and likely changes important for fertilization and the oocyte-to-embryo transition. This chapter focuses on signaling mechanisms required for oocyte growth and meiotic maturation in C. elegans and discusses how these mechanisms coordinate the completion of meiosis and the oocyte-to-embryo transition.

ß-COP Suppresses the Surface Expression of the TREK2.

K2P channels, also known as two-pore domain K+ channels, play a crucial role in maintaining the cell membrane potential and contributing to potassium homeostasis due to their leaky nature. The TREK, or tandem of pore domains in a weak inward rectifying K+ channel (TWIK)-related K+ channel, subfamily within the K2P family consists of mechanical channels regulated by various stimuli and binding proteins. Although TREK1 and TREK2 within the TREK subfamily share many similarities, ß-COP, which was previously known to bind to TREK1, exhibits a distinct binding pattern to other members of the TREK subfamily, including TREK2 and the TRAAK (TWIK-related acid-arachidonic activated K+ channel). In contrast to TREK1, ß-COP binds to the C-terminus of TREK2 and reduces its cell surface expression but does not bind to TRAAK. Furthermore, ß-COP cannot bind to TREK2 mutants with deletions or point mutations in the C-terminus and does not affect the surface expression of these TREK2 mutants. These results emphasize the unique role of ß-COP in regulating the surface expression of the TREK family.

Nanoscale Three-Dimensional Network Structure of a Mesoporous Particle Unveiled via Adaptive Multidistance Coherent X-ray Tomography.

Mesoporous nanoparticles provide rich platforms to devise functional materials by customizing the three-dimensional (3D) structures of nanopores. With the pore network as a key tuning parameter, the noninvasive and quantitative characterization of these 3D structures is crucial for the rational design of functional materials. This has prompted researchers to develop versatile nanoprobes with a high penetration power to inspect various specimens sized a few micrometers at nanoscale 3D resolutions. Here, with adaptive phase retrievals on independent data sets with different sampling frequencies, we introduce multidistance coherent X-ray tomography as a noninvasive and quantitative nanoprobe to realize high-resolution 3D imaging of micrometer-sized specimens. The 3D density distribution of an entire mesoporous silica nanoparticle was obtained at 13 nm 3D resolution for quantitative physical and morphological analyses of its 3D pore structure. The morphological features of the whole 3D pore network and pore connectivity were examined to gain insight into the potential functions of the particles. The proposed multidistance tomographic imaging scheme with quantitative structural analyses is expected to advance studies of functional materials by facilitating their structure-based rational design.

Recent advances in amorphous electrocatalysts for oxygen evolution reaction.

Oxygen evolution reaction (OER) has attracted great attention as an important half-reaction in the electrochemical splitting of water for green hydrogen production. However, the inadequacy of highly efficient and stable electrocatalysts has impeded the development of this technology. Amorphous materials with long-range disordered structures have exhibited superior electrocatalytic performance compared to their crystalline counterparts due to more active sites and higher structural flexibility. This review summarizes the preparation methods of amorphous materials involving oxides, hydroxide, phosphides, sulfides, and their composites, and introduces the recent progress of amorphous OER electrocatalysts in acidic and alkaline media. Finally, the existing challenges and future perspectives for amorphous electrocatalysts for OER are discussed. Therefore, we believe that this review will guide designing amorphous OER electrocatalysts with high performance for future energy applications.

Preparation of Practical High-Performance Electrodes for Acidic and Alkaline Media Water Electrolysis.

The synthesis of electrocatalyst and the electrode preparation were merged into a one-step process and proved to be a versatile method to synthesize metal oxide electrocatalysts on the conductive carbon paper (CP). Very simply, the metal precursor deposited on the CP was thermally treated by a torch-gun for just 6 s, resulting in the formation of RuO2 , Co3 O4 , and mixed oxide nanoparticles. The material could be directly used as working electrode for oxygen evolution reaction (OER). Compared with commercial and other state-of-the-art electrocatalysts, the fabricated electrode showed a superior electrocatalytic activity for OER in 1 m HClO4 and 1 m KOH in terms of not only a low overpotential to reach 10 mA cm-2 but also a high current density at 1.6 VRHE with satisfying a long-term stability. The novel strategy without requiring time-consuming and uneconomical steps could be expanded to the preparation of various metal oxides on conductive substrates towards diverse electrocatalytic applications.

What influences company attachment and job performance in the COVID-19 era?: Airline versus hotel employees.

Airline and hotel employees are experiencing multiple forms of precariousness amid the COVID-19 pandemic, which have increased workers' distrust of their respective airline/hotel businesses and affected job performance and retention. This research builds and tests two sturdy theoretical frameworks to explain airline and hotel employees' job performance and behavior during the COVID-19 pandemic. The frameworks, developed using a quantitative method, adequately account for employees' company attachment and job performance by using their perceived job insecurity, life satisfaction, and job satisfaction as the key antecedents; while employees' perceived job insecurity influences the formation of attachment to the company and job performance. The mediating nature of life and job satisfaction is also examined alongside the moderating role of two different industry types (airline versus hotel). The results show that the process of generating job performance differs between airline and hotel employee groups. The research implications and value are discussed.

ß-COP Regulates TWIK1/TREK1 Heterodimeric Channel-Mediated Passive Conductance in Astrocytes.

Mature astrocytes are characterized by a K+ conductance (passive conductance) that changes with a constant slope with voltage, which is involved in K+ homeostasis in the brain. Recently, we reported that the tandem of pore domains in a weak inward rectifying K+ channel (TWIK1 or KCNK1) and TWIK-related K+ channel 1 (TREK1 or KCNK2) form heterodimeric channels that mediate passive conductance in astrocytes. However, little is known about the binding proteins that regulate the function of the TWIK1/TREK1 heterodimeric channels. Here, we found that ß-coat protein (COP) regulated the surface expression and activity of the TWIK1/TREK1 heterodimeric channels in astrocytes. ß-COP binds directly to TREK1 but not TWIK1 in a heterologous expression system. However, ß-COP also interacts with the TWIK1/TREK1 heterodimeric channel in a TREK1 dependent manner and enhances the surface expression of the heterodimeric channel in astrocytes. Consequently, it regulates TWIK1/TREK1 heterodimeric channel-mediated passive conductance in astrocytes in the mouse brain. Taken together, these results suggest that ß-COP is a potential regulator of astrocytic passive conductance in the brain.

The impact of COVID-19 on consumer evaluation of authentic advertising messages.

This study investigates the relationship between the COVID-19 threat and consumer evaluation of a product with authenticity appeals in advertisements. We propose that threatening situations like COVID-19 motivate consumers to lower their uncertainty and increase their preference for products with authentic advertising messages. Because individuals react differently to threatening environments according to their early-life experiences, commonly reflected in childhood socioeconomic status, we examined whether childhood socioeconomic status moderates the relationship between threat and consumer evaluation of authenticity in advertisements. First, secondary data from Google Trends provided empirical support for our predictions. In additional experimental studies, participants evaluated different target products in four studies that either manipulated (Studies 2 and 3) or measured (Studies 4 and 5) COVID-19 threat. Our results provide converging evidence that consumers positively evaluate products with authentic advertising messages under the COVID-19 threat. Consumers' motivation to lower their uncertainty underlies the effect of COVID-19 threat on their evaluation of authentic messages (Study 3). This attempt to reduce uncertainty is more likely to occur for consumers with relatively higher childhood socioeconomic status (Studies 4 and 5). These findings suggest that using authenticity appeals during a pandemic could effectively reduce consumers' perceived uncertainty and generate positive consumer evaluations.