Real-time analysis of large-scale neuronal imaging enables closed-loop investigation of neural dynamics.

Large-scale imaging of neuronal activities is crucial for understanding brain functions. However, it is challenging to analyze large-scale imaging data in real time, preventing closed-loop investigation of neural circuitry. Here we develop a real-time analysis system with a field programmable gate array-graphics processing unit design for an up to 500-megabyte-per-second image stream. Adapted to whole-brain imaging of awake larval zebrafish, the system timely extracts activity from up to 100,000 neurons and enables closed-loop perturbations of neural dynamics.

Metal-organic frameworks with fine-tuned interlayer spacing for microwave absorption.

Designing a functional, conductive metal-organic framework (cMOF) is highly desired. Substantial efforts have been dedicated to increasing the intralayer conjugation of the cMOFs, while less dedication has been made to tuning the interlayer charge transport of the metal-organic nanosheets for the controllable dielectric property. Here, we construct a series of conductive bimetallic organic frameworks of (ZnxCu3-x) (hexahydroxytriphenylene)2 (ZnCu-HHTP) to allow for fine-tuned interlayer spacing of two-dimensional frameworks, by adjusting the ratios of Zn and Cu metal ions. This approach for atomistic interlayer design allows for the finely control of the charge transport, band structure, and dielectric properties of the cMOF. As a result, Zn3Cu1-HHTP, with an optimal dielectric property, exhibits high-efficiency absorption in the gigahertz microwave range, achieving an ultra-strong reflection loss of -81.62 decibels. This study not only advances the understanding of the microstructure-function relationships in cMOFs but also offers a generic nanotechnology-based approach to achieving controllable interlayer spacing in MOFs for the targeted applications.

Effects of periodic heat events on the reproduction and longevity of female and male Agasicles hygrophila (Coleoptera: Chrysomelidae).

Alternanthera philoxeroides (Amaranthaceae), commonly known as alligator weed, is a globally invasive and detrimental perennial weed. Agasicles hygrophila serves as an important biocontrol agent for alligator weeds. However, during mid-summer, when temperatures increase, A. hygrophila populations experience a significant decline, leading to ineffective weed control. This study has examined the impact of periodic heat events on the reproduction and survival of A. hygrophila females and males using various mating combinations and durations of temperature treatments. The results demonstrated significant effects on all of the studied parameters across mating combinations when compared with the control. Under the same temperature combination, the fecundity and survival rates of females, as well as the egg-hatching rate, decreased significantly with increasing repeated heat exposure. Furthermore, the egg-hatching rate varied significantly among different temperatures and time-interval combinations. In addition, the females displayed greater sensitivity to heat stress than males in terms of fecundity. These findings enhance our understanding of A. hygrophila population dynamics during summer and provide insights into the release of biocontrol agents in diverse regions with varying climates.

Biomimetic chiral hydrogen-bonded organic-inorganic frameworks.

Assembly ubiquitously occurs in nature and gives birth to numerous functional biomaterials and sophisticated organisms. In this work, chiral hydrogen-bonded organic-inorganic frameworks (HOIFs) are synthesized via biomimicking the self-assembly process from amino acids to proteins. Enjoying the homohelical configurations analogous to α-helix, the HOIFs exhibit remarkable chiroptical activity including the chiral fluorescence (glum = 1.7 × 10-3) that is untouched among the previously reported hydrogen-bonded frameworks. Benefitting from the dynamic feature of hydrogen bonding, HOIFs enable enantio-discrimination of chiral aliphatic substrates with imperceivable steric discrepancy based on fluorescent change. Moreover, the disassembled HOIFs after recognition applications are capable of being facilely regenerated and self-purified via aprotic solvent-induced reassembly, leading to at least three consecutive cycles without losing the enantioselectivity. The underlying mechanism of chirality bias is decoded by the experimental isothermal titration calorimetry together with theoretic simulation.

Recent bio-applications of covalent organic framework-based nanomaterials.

Appearing as a new class of functional organic materials, covalent organic frameworks (COFs) have aroused a huge wave of interest in versatile fields ever since they were first proposed in 2005. Thanks to but not limited to their ultralight weights, high surface areas, ordered channels, variable functional groups and well-defined crystal structures, the applications of COF-based biomaterials in the fields of drug loading and delivery, photodynamic therapy, photothermal therapy, bioimaging, etc. are comprehensively summarized and introduced. The existing challenges and future prospects for this emerging but hot research direction are also discussed. It is hoped that this review will serve as a guidance for future research on COFs as multifunctional bioplatforms.

Biomolecules meet organic frameworks: from synthesis strategies to diverse applications.

Biomolecules are essential in pharmaceuticals, biocatalysts, biomaterials, etc., but unfortunately they are extremely susceptible to extraneous conditions. When biomolecules meet porous organic frameworks, significantly improved thermal, chemical, and mechanical stabilities are not only acquired for raw biomolecules, but also molecule sieving, substrate enrichment, chirality property, and other functionalities are additionally introduced for application expansions. In addition, the intriguing synergistic effect stemming from elaborate and concerted interactions between biomolecules and frameworks can further enhance application performances. In this paper, the synthesis strategies of the so-called bio-organic frameworks (BOFs) in recent years are systematically reviewed and classified. Additionally, their broad applications in biomedicine, catalysis, separation, sensing, and imaging are introduced and discussed. Before ending, the current challenges and prospects in the future for this infancy-stage but significant research field are also provided. We hope that this review will offer a concise but comprehensive vision of designing and constructing multifunctional BOF materials as well as their full explorations in various fields.

Versatile Structural Engineering of Metal-Organic Frameworks Enabling Switchable Catalytic Selectivity.

The structure engineering of metal-organic frameworks (MOFs) forms the cornerstone of their applications. Nonetheless, realizing the simultaneous versatile structure engineering of MOFs remains a significant challenge. Herein, a dynamically mediated synthesis strategy to simultaneously engineer the crystal structure, defect structure, and nanostructure of MOFs is proposed. These include amorphous Zr-ODB nanoparticles, crystalline Zr-ODB-hz (ODB = 4,4'-oxalyldibenzoate, hz = hydrazine) nanosheets, and defective d-Zr-ODB-hz nanosheets. Aberration-corrected scanning transmission electron microscopy combined with low-dose high-angle annular dark-field imaging technique vividly portrays these engineered structures. Concurrently, the introduced hydrazine moieties confer self-reduction properties to the respective MOF structures, allowing the in situ installation of catalytic Pd nanoparticles. Remarkably, in the hydrogenation of vanillin-like biomass derivatives, Pd/Zr-ODB-hz yields partially hydrogenated alcohols as the primary products, whereas Pd/d-Zr-ODB-hz exclusively produces fully hydrogenated alkanes. Density functional theory calculations, coupled with experimental evidence, uncover the catalytic selectivity switch triggered by the change in structure type. The proposed strategy of versatile structure engineering of MOFs introduces an innovative pathway for the development of high-performance MOF-based catalysts for various reactions.

Recent Progress on Phase Engineering of Nanomaterials.

As a key structural parameter, phase depicts the arrangement of atoms in materials. Normally, a nanomaterial exists in its thermodynamically stable crystal phase. With the development of nanotechnology, nanomaterials with unconventional crystal phases, which rarely exist in their bulk counterparts, or amorphous phase have been prepared using carefully controlled reaction conditions. Together these methods are beginning to enable phase engineering of nanomaterials (PEN), i.e., the synthesis of nanomaterials with unconventional phases and the transformation between different phases, to obtain desired properties and functions. This Review summarizes the research progress in the field of PEN. First, we present representative strategies for the direct synthesis of unconventional phases and modulation of phase transformation in diverse kinds of nanomaterials. We cover the synthesis of nanomaterials ranging from metal nanostructures such as Au, Ag, Cu, Pd, and Ru, and their alloys; metal oxides, borides, and carbides; to transition metal dichalcogenides (TMDs) and 2D layered materials. We review synthesis and growth methods ranging from wet-chemical reduction and seed-mediated epitaxial growth to chemical vapor deposition (CVD), high pressure phase transformation, and electron and ion-beam irradiation. After that, we summarize the significant influence of phase on the various properties of unconventional-phase nanomaterials. We also discuss the potential applications of the developed unconventional-phase nanomaterials in different areas including catalysis, electrochemical energy storage (batteries and supercapacitors), solar cells, optoelectronics, and sensing. Finally, we discuss existing challenges and future research directions in PEN.

Modulation of the assembly fashion among metal-organic frameworks for enantioretentive epoxide activation.

Highly enantioretentive alcoholysis of epoxides is an important way to synthesize enantiopure ß-alkoxy alcohols, which are irreplaceable intermediates demanded by biomedicines, fine chemicals and other industries. In this report, we exploit a series of Zr-based metal-organic frameworks (Zr-MOFs) as the catalysts to achieve high activity and enantioretentivity in the alcoholysis of styrene oxide via modulating their assembly fashions. It is explored that hcp-UiO-66 not only exhibits a ∼10 fold improved catalytic activity than both hxl-CAU-26 and fcc-UiO-66 of varied assemblies but also maintains superior product enantioretentivity. Theoretic calculations together with experimental proof discloses the origin of distinct catalytic activity caused by different assembly fashions. This assembly modulation strategy offers a potential protocol for seeking high-performance catalysts among MOFs by virtue of their rich polymorphisms.

Conductive Metal-Organic Frameworks with Tunable Dielectric Properties for Boosting Electromagnetic Wave Absorption.

Metal-organic frameworks (MOFs) manifest enormous potential in promoting electromagnetic wave (EMW) absorption thanks to the tailored components, topological structure, and high porosity. Herein, rodlike conductive MOFs (cMOFs) composed of adjustable metal ions of Zn, Cu, Co, or Ni and ligands of hexahydroxytriphenylene (HHTP) are prepared to attain tunable dielectric properties for a tailored EMW absorption. Specifically, the influences of the cMOFs' composition, charge transport characteristic, topological crystalline structure, and anisotropy microstructure on dielectric and EMW absorption performance are ascertained, advancing the understanding of EMW attenuation mechanisms of MOFs. The boosted conductive and polarization losses derived from the conjugation effects and terminal groups, as well as shape anisotropy, lead to a prominent EMW absorption of the cMOFs. The Cu-HHTP confers a minimum reflection loss (RLmin) of -63.55 dB at the thickness of 2.9 mm and a maximum effective absorption bandwidth of 5.2 GHz. Moreover, Zn-HHTP showcases the absorption superiority in the S-band (2-4 GHz) with an RLmin of -62.8 dB at a thickness of 1.9 mm. This work not only hoists the mechanistic understanding of the structure-function relationships for the cMOFs but also offers guidelines for preparing functional MOF materials.

Single Site Coordination Enabled Construction of Metal-Diketimine-Linked Covalent Organic Frameworks for Boosted Electrooxidation of Biomass Derivative.

Aromatic aldehydes are widely used for the construction of covalent organic frameworks (COFs). However, due to the high flexibility, high steric hindrance, and low reactivity, it remains challenging to synthesize COFs using ketones as building units, especially the highly flexible aliphatic ones. Here, the single nickel site coordination strategy is reported to lock the configurations of the highly flexible diketimine to transform discrete oligomers or amorphous polymers into highly crystalline nickel-diketimine-linked COFs (named as Ni-DKI-COFs). The strategy has been successfully extended to the synthesis of a series of Ni-DKI-COFs by the condensation of three flexible diketones with two tridentate amines. Thanks to the ABC stacking model with high amount and easily accessible single nickel (II) sites on their 1D channels, Ni-DKI-COFs are exploited as well-defined electrocatalyst platforms for efficiently electro-upgrading biomass-derived 5-Hydroxymethylfurfural (HMF) into value-added 2,5-furandicarboxylic acid (FDCA) with a 99.9% yield and a 99.5% faradaic efficiency as well as a high turnover frequency of 0.31 s-1 .

Host-Plant Selection Behavior of Ophraella communa, a Biocontrol Agent of the Invasive Common Ragweed Ambrosia artemisiifolia.

Understanding the host-selection behavior of herbivorous insects is important to clarify their efficacy and safety as biocontrol agents. To explore the host-plant selection of the beetle Ophraella communa, a natural enemy of the alien invasive common ragweed (Ambrosia artemisiifolia), we conducted a series of outdoor choice experiments in cages in 2010 and in open fields in 2010 and 2011 to determine the preference of O. communa for A. artemisiifolia and three non-target plant species: sunflower (Helianthus annuus), cocklebur (Xanthium sibiricum), and giant ragweed (Ambrosia trifida). In the outdoor cage experiment, no eggs were found on sunflowers, and O. communa adults rapidly moved from sunflowers to the other three plant species. Instead, adults preferred to lay eggs on A. artemisiifolia, followed by X. sibiricum and A. trifida, although very few eggs were observed on A. trifida. Observing the host-plant selection of O. communa in an open sunflower field, we found that O. communa adults always chose A. artemisiifolia for feeding and egg laying. Although several adults (<0.02 adults/plant) stayed on H. annuus, no feeding or oviposition were observed, and adults quickly transferred to A. artemisiifolia. In 2010 and 2011, 3 egg masses (96 eggs) were observed on sunflowers, but they failed to hatch or develop into adults. In addition, some O. communa adults crossed the barrier formed by H. annuus to feed and oviposit on A. artemisiifolia planted in the periphery, and persisted in patches of different densities. Additionally, only 10% of O. communa adults chose to feed and oviposit on the X. sibiricum barrier. These findings suggest that O. communa poses no threat to the biosafety of H. anunuus and A. trifida and exhibits a robust dispersal capacity to find and feed on A. artemisiifolia. However, X. sibiricum has the potential to be an alternative host plant for O. communa.

Antioxidant, antibacterial, and anti-inflammatory Periplaneta americana remnant chitosan/polysaccharide composite film: In vivo wound healing application evaluation.

Periplaneta americana (P. americana), which is widely used for wound healing in China, produces a large amount of solid waste (P. americana remnant) after pharmaceutical production extraction. P. americana remnant chitosan (PAC) has a low molecular weight, low crystallinity, and easily modifiable structural properties. In this study, PAC and P. americana remnant polysaccharide (PAP) were used as raw materials to prepare a composite film (PAPCF). The good biocompatibility of the composite film was verified by cell proliferation assays and protein adsorption assays. The bioactivity of the composite film was assessed by antibacterial and in vivo/vitro antioxidant assays to evaluate its potential as a wound dressing. The wound healing experiment revealed that PAPCF improved wound closure and collagen deposition, decreased reactive oxygen species levels, and attenuated the inflammatory response, enabling rapid wound healing from the inflammatory phase to the proliferative phase in mice. Additionally, PAPCF was administered only once, reducing the chance of infection from multiple deliveries. In summary, this paper presents an easy-to-administer, cost-effective, and effective dressing candidate for wound treatment based on the environmental concept of resource reuse.

A strategic analysis of incorporating corporate environmental responsibility into managerial incentive design: a differential game approach.

As corporations' environmental impacts come under greater scrutiny from global financial, regulatory, and societal stakeholders, management scholars have increasingly focused on the role corporate governance plays in undertaking corporate environmental responsibility (CER). This paper combines managerial incentives and CER in a dynamic environment to formulate a differential game model of managerial incentive design in a duopolistic market, investigating whether companies with profit-maximizing interests are motivated to provide their professional managers with incentives related to CER and the impact of such incentives on corporate profitability, social welfare and emissions reduction. The results demonstrate the following: (1) Employing professional managers increases the emissions reduction efforts of firms and giving incentives to professional managers further increases the emissions reduction level of firms. (2) When a firm employs a professional manager and pays him or her a fixed salary, it generates slightly less income than it does when a manager is not employed; however, if the professional manager is given CER-related incentives, the firm's income is greatly increased. (3) As long as professional managers are employed, social welfare increases regardless of whether professional managers are given incentive pay. (4) The emissions reduction of a firm increases with an increase in the income distribution coefficient π1. This paper extends the existing CER decision-making model by considering different managerial incentive designs, providing new insights into CER and enterprise organizational strategy and offering useful policy recommendations and a scientific basis for environmental governance, which is expected to be useful for finding ways to balance economic development and environmental protection.

A gradient Sn4+@Sn2+ core@shell structure induced by a strong metal oxide-support interaction for enhanced CO2 electroreduction.

Oxidation states of Sn in tin oxides are hard to regulate due to the uncontrollable evolution during the electrochemical CO2 reduction reaction (CO2RR), thus limiting the adsorption capabilities and reaction kinetics. Herein, we propose a metal oxide-support interaction-mediated strategy to modify the electronic properties of tin oxides. A gradient Sn4+@Sn2+ core@shell structure was formed as a result of electron transfer from g-C3N4 to anchored SnO2, unlike reduced graphene oxide (rGO)-supported SnO2 with Sn4+-rich surfaces. Such unique structures were revealed by the depth profiles of X-ray photoelectron spectra, and they enhanced the adsorption and stabilization of the *CO2˙- intermediate and accelerated the reaction kinetics. Consequently, SnO2/g-C3N4 delivered a faradaic efficiency of 95.1% for the C1 products at -1.06 V, exceeding those of SnO2/rGO and most reported catalysts. Moreover, the performances were sustained for 70 h without obvious degradation. This work offers an alternative route to efficient catalyst design by combining oxidation state regulation and metal oxide-support interaction and contributes to the development of sustainable technologies for achieving carbon neutrality.

[Genetic diversity and population structure of germplasm resources of Amomum villosum based on SSR markers].

Amomum villosum, serving as an important medicinal material, is complex in the genetic background of germplasm resources. Exploring the genetic diversity and genetic relationship of germplasm resources is conducive to clarifying the germplasm source and genetic background of A. villosum, so as to improve the efficiency of parent selection and variety breeding of A. villosum. Seventy-one pairs of SSR primers were used for PCR amplification of 84 A. villosum samples by polyacrylamide gel electrophoresis. Fifty-four pairs of SSR primers with high polymorphism were screened out for the analysis of genetic diversity. The results showed that 293 alleles were detected from 84 germplasm resources by 54 pairs of SSR primers, with an average of 5.32 alleles for each pair of primers, and a variation range of 3-8, and the primer AVL12 marked the highest number of alleles. The PIC value of each locus varied from 0.068 7 to 0.828 9, with an average of 0.529 9, and the highest was marked by AVL24. The genetic diversity of A. villosum was the highest in Yunnan, followed by Guangxi, and the lowest was found in Guangdong. The population structure analysis and cluster analysis showed that the samples were classified into two groups. In terms of origin, samples from Yunnan and Guangxi had a close genetic relationship, and there was no obvious differentiation of A, villosum resources from different origins. In this study, 54 pairs of SSR markers were used to analyze the genetic diversity and population structure of 84 germplasm resources, which can reflect the genetic relationship between A. villosum samples from different germplasm sources and different populations, thus providing a theoretical basis for the collection, research, and breeding of A. villosum resources.

Research on mechanisms to incentivize corporate environmental responsibility based on a differential game approach.

As major polluters, enterprises are expected to behave responsibly toward the natural environment. However, enterprises often do not pay enough attention to the environment and may even be environmentally irresponsible. Encouraging enterprises to actively accept environmental responsibility is the key to solving the problem of environmental pollution. This paper uses a differential game model to study the impact of different governmental incentive mechanisms on corporate environmental responsibility (CER). The results of the study show that independent, noncooperative decision-making by the government and the enterprise is not desirable. If the government provides a monetary incentive to the enterprise or sets a corporate pollution threshold to stimulate enterprises' acceptance of environmental responsibility, environmental quality can be improved. These results lead to useful policy recommendations and a scientific basis for environmental governance, which is expected to be helpful for finding ways to balance economic development and environmental protection in developing countries more generally.

Isoreticular Series of Two-Dimensional Covalent Organic Frameworks with the kgd Topology and Controllable Micropores.

Two-dimensional (2D) covalent organic frameworks (COFs) possess designable pore architectures but limited framework topologies. Until now, 2D COFs adopting the kgd topology with ordered and rhombic pore geometry have rarely been reported. Here, an isoreticular series of 2D COFs with the kgd topology and controllable pore size is synthesized by employing a C6-symmetric aldehyde, i.e., hexa(4-formylphenyl)benzene (HFPB), and C3-symmetric amines i.e., tris(4-aminophenyl)amine (TAPA), tris(4-aminophenyl)trazine (TAPT), and 1,3,5-tris[4-amino(1,1-biphenyl-4-yl)]benzene (TABPB), as building units, referred to as HFPB-TAPA, HFPB-TAPT, and HFPB-TABPB, respectively. The micropore dimension down to 6.7 Å is achieved in HFPB-TAPA, which is among the smallest pore size of reported 2D COFs. Impressively, both the in-plane network and stacking sequence of the 2D COFs can be clearly observed by low-dose electron microscopy. Integrating the unique kgd topology with small rhombic micropores, these 2D COFs are endowed with both short molecular diffusion length and favorable host-guest interaction, exhibiting potential for drug delivery with high loading and good release control of ibuprofen.

Hetero-Shelled Hollow Structure Coupled with Non-Thermal Plasma Inducing Spatial Charge Rearrangement for Superior NO Conversion and Sulfur Resistance.

Facilitating the mass transfer and spatial charge separation is a great challenge for achieving efficient oxidation of NO and outstanding sulfur resistance. Herein, a hydrothermal-assisted confinement growth technique is used to fabricate well-defined three-dimensional CuOx@MnOx hetero-shelled hollow-structure catalysts. By integrating the coupled plasma space reactor and the porous hierarchical structure of the catalyst, excellent stability (10 h) and high conversion of NO (93.86%) are reached under the concentration of SO2 (1000 mg m-3 ) and NO (200 mg m-3 ). Impressively, precise surface characterization and detailed density functional theory calculations show that the spatial hetero-shelled micro-reactor can orient the redox pairs transportation, facilitating the combination of NO with the surface coordinately unsaturated O atoms, and also prevent the poisoning of SO2 molecules due to the curvature and surface charge effect in the non-thermal plasma equipment.

Organic microporous crystals driven by pure C-H⋯π interactions with vapor-induced crystal-to-crystal transformations.

Organic porous crystals constructed by only a single kind of weak molecular interaction are invaluable to understanding the nature of the formation of organic porous materials and developing new types of porous materials. Here, we designed and synthesized two pure organic compounds of PBO and PBS through integrating planar dibenzothiophene/dibenzofuran and two phenothiazine groups together with twisted C-N bonds, which form organic microporous crystals with very good stability against strong acids and bases VIA pure C-H⋯π interactions. Accordingly, the effective absorption of toluene has been successfully realized with an adsorbing capacity of 6.20 mmol g-1, regardless of the interference of water vapor. Excitingly, these microporous materials exhibit interesting crystal-to-crystal transformation (CCT) properties accompanied by changed pore size on being exposed to different organic vapors. Therefore, the desorption process of toluene could be completed through a simple exposure to dichloromethane (DCM) vapor and the second transformation of the crystal occurred in this process.