Heterogeneous Organohydrogel Toward Automated and Interference-Free Gradient Feeding of Drugs in Cell Screening.

Cell-based microarrays are widely used in the fields of drug discovery and toxicology. Precise gradient generation and automated drug feeding are essential for high-throughput screening of live cells in tiny droplets. However, most existing technologies either require sophisticated robotic equipment or cause mechanical/physiological interference with cells. Here, a heterogeneous organohydrogel is presented for automated gradient drug feeding, while ensuring minimal interference with cells. The heterogeneous organohydrogel comprises three crucial components. The bottom surface can automatically generate gradients functioning as a gradient generator, the organohydrogel bulk allows unidirectional transport of drugs without backflow, and the top surface with hydrophilic arrays can firmly anchor the cell-based droplet array to evaluate the concentration-dependent bioeffects of drugs accurately. Such a unique structure enables universal screening of different cell types and drugs dissolved in different solvents, requiring neither additional accessories nor arduous drug functionalization. The heterogeneous organohydrogel with unprecedented automation and non-interference possesses the enormous potential to be a next-generation platform for drug screening.

[Advances in Research of the Effects and Mechanisms of Polyethylene Microplastics on Soil Nitrogen Transformation].

In the agricultural lands of China, polyethylene is the main component of microplastics （MPs）, with characteristics such as small size, wide distribution, easy accumulation, and difficult degradation. Therefore, it may have an impact on the elemental cycling process of the soil. On the basis of reviewing the key literatures in the past few years, this study systematically analyzed and summarized the key factors and processes of the polyethylene microplastics （PE-MPs） affecting soil nitrogen transformation. On the one hand, PE-MPs directly affected the activities of microorganisms and key enzymes related to soil nitrogen transformation by enriching microorganisms, selecting colonized microbial populations, and releasing additives. On the other hand, PE-MPs had indirect impacts on the activities of microorganisms and key enzymes related to soil nitrogen transformation by affecting soil physicochemical properties of soil and changing the microenvironment for microbial growth. Moreover, phthalates, an important additive of the MPs, may be the key factor affecting soil nitrogen transformation in the short-term. Finally, we posed key scientific issues that should be further studied in order to provide scientific support for nitrogen nutrition regulation and ecological risk assessment of soils contaminated by PE-MPs.

DFT study of electron donor-acceptor (EDA) complexes: mechanism exploration and theoretical prediction.

Organic synthesis methods initiated by visible light have received increasing attention from synthetic chemists. Reactions initiated by EDA complexes do not require the use of toxic or expensive photoredox catalysts, unlike traditional photoreaction processes. However, this kind of reaction requires a particular structure for the substrate, so it is important to study the detailed and systematic reaction mechanism for its design. EDA complexes of substituted 1H-indole and substituted benzyl bromide derivatives were studied by density functional theory (DFT). The difference between EDA complexes with substituents of different kinds and locations were compared by theoretical study and a new EDA complex was predicted.

Study on the multifunctional spatial-temporal evolution and coupling coordination of cultivated land: A case study of Hebei Province, China.

The rational use of cultivated land can guarantee food security and thus is highly important for ensuring social stability, economic development and national security. The current study investigated the multifunctional temporal and spatial variation characteristics of cultivated land and explored the spatial and temporal characteristics of the multifunction and coupling coordination degrees of cultivated land throughout Hebei Province. Based on the administrative division data, statistical yearbook data and land use status data of the impacted areas, a multifunctional evaluation index system of cultivated land was established. The CRITIC weight method and entropy weight method were used to determine the weight of the index, the comprehensive index model was used to determine the production, social security, ecology and landscape functions of cultivated land of Hebei Province in different periods, the coupling coordination model was used to explore the multifunctional coupling coordination degree of cultivated land in each county, and spatial autocorrelation analysis was performed to determine the correlation of the multifunctional coupling coordination degrees. From 2000 to 2020, the production, social security and landscape function of cultivated land in Hebei Province trended upward; the ecological function trended slightly downward. The multifunctional coupling coordination degree of cultivated land in Hebei Province trended significantly upward and changed from limited coordination to intermediate coordination. Furthermore, it exhibited strong agglomeration and a significant positive spatial correlation, forming a 'V'-type change rule of first decreasing and then increasing. Hebei Province exhibited remarkable spatial and temporal characteristics of the multifunction and coupling coordination degrees of cultivated land. Regions could thus customize different cultivated land functions to maximize the benefits of cultivated land use. The findings of this study may provide a scientific basis and theoretical support for sustainably using and managing cultivated land resources in areas with similar human geographical environments.

Cascaded Heteroporous Nanocomposites for Thermo-Adaptive Passive Radiation Cooling.

Passive radiative cooling is a promising technology for heat dissipation that does not consume energy. However, current radiative cooling materials can only exhibit subambient cooling under atmospheric conditions and struggle to process specific heat accumulation. Thus, a passive thermal regulation mechanism adapted to wide-temperature-range applications is required to match device heating systems. Herein, a heteroporous nanocomposite film (HENF) with thermo-adaptive radiation cooling performance is reported. Compared to conventional porous cooling films with limited scattering efficiencies, the HENFs with multistage scattering have a strong emissivity of 96.5% (8-13 µm) and a high reflectivity of 97.3% (0.3-2.5 µm), resulting in an ultrahigh cooling power of 114 W m-2. In such HENFs, theoretical analyses have confirmed the spectrum management superiority of the heteroporous unit in terms of the scattering efficiency strength, with their cascading effect enhancing the overall film-cooling efficiency. The high mechanical performance, phase-transition features, and environmental adaptive properties of HENFs are also exhibited. Importantly, HENFs synergistically couple thermal dissipation and absorption to effectively process heat accumulation and counteract thermal shock in heating devices. It is anticipated that thermo-adaptive HENFs will act as a promising platform for device surface thermal regulation over a wide temperature range.

Liquid-Like Surfaces with Enhanced De-Wettability and Durability: From Structural Designs to Potential Applications.

Liquid-like surfaces (LLSs) with dynamic repellency toward various pollutants (e.g., bacteria, oil, and ice), have shown enormous potential in the fields of biology, environment, and energy. However, most of the reported LLSs cannot meet the demands for practical applications, particularly in terms of de-wettability and durability. To solve these problems, considerable progress has been made in enhancing the de-wettability and durability of LLSs in complex environments. Therefore, this review mainly focuses on the recent progress in LLSs, encompassing designed structures and repellent capabilities, as well as their diverse applications, offering greater insights for the targeted design of desired LLSs. First, a detailed overview of the development of LLSs from the perspective of their molecular structural evolution is provided. Then highlight recent approaches for enhancing the dynamic de-wettability and durability of LLSs by optimizing their structural designs, including linear, looped, crosslinked, and hybrid structures. Later, the diverse applications and unique advantages of recently developed LLSs, including repellency (e.g., liquid anti-adhesion/transportation/condensation, anti-icing/scaling/waxing, and biofouling repellency) are summarized. Finally, Perspectives on potential innovative advancements and the promotion of technology selection to advance this exciting field are offered.

Bio­Inspired Magnetic­Responsive Supramolecular­Covalent Semi­Convertible Hydrogel.

Bio-inspired magnetic-responsive hydrogel is confined in exceedingly narrow spaces for soft robots and biomedicine in either gel state or magnetofluidic sol state. However, the motion of the gel state magnetic hydrogel will be inhibited in various irregular spaces due to the fixed shape and size and the sol-state magnetofluid gel may bring unpredictable residues in the confined narrow space. Inspired by the dynamic liquid lubricating mechanism of biological systems, novel magnetic-responsive semi-convertible hydrogel (MSCH) is developed through imbedding magnetic-responsive gelatin and amino-modified Fe3O4 nanoparticles network into the covalent network of polyvinyl alcohol, which can be switched between gel state and gel-sol state in response to magnetic stimuli. It can be attributed the disassembly of triple-helix structures of the gelatin under the action of the magnetic field, driven by force from the magnetic particles conjugated on the gelatin chain through electrostatic interactions, while the covalent network retains the hydrogel structural integrity. This leads to a sol layer on the MSCH surface enabling the MSCH to pass effectively through the confined channel or obstacle under magnetic field. The present MSCH will provide an alternative mode for magnetic field-related soft robots or actuators.

Land scale division and multifunctional evaluation for Fuping County, China, based on DEM-based watershed analysis.

Land is the spatial background and basic carrier of human survival and development. The study of land function evaluation at different scales can promote the harmonious coexistence of humans and nature. Taking Fuping County, Hebei Province, China, as an example, this study establishes the theoretical framework of county-level land scale division using a digital elevation model (DEM)-based watershed analysis method and establishes the theory and methodological system of land function evaluation from the perspective of the characteristic scale. The multifunctionality of the land was evaluated using the Carnegie-Ames-Stanford approach (CASA), the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model and comprehensive index evaluation. By using the methods of DEM-based watershed analysis, dominant factor differentiation and layer superposition, a three-level scale system of 'subwatershed scale-land chain scale-land segment scale' and a multifunctional multiscale evaluation index system containing 18 evaluation indices were established. The single-function and multifunction evaluation results of land at different scales were obtained by the comprehensive index method and Getis-Ord Gi* index method. The accuracy of land function evaluation results mainly depends on the selection of the measurement scale. The land measurement scale determined by DEM-based watershed analysis is close to the intrinsic scale of land function evaluation. The scale effect of land function in different temporal and spatial ranges is also evident and shows obvious spatial heterogeneity and difference. At larger scales, individual functions show synergistic effects.

A Viscous-Biofluid Self-Pumping Organohydrogel Dressing to Accelerate Diabetic Wound Healing.

Viscous biofluids on wounds challenge conventional "water-absorbing" wound dressings in efficient drainage due to their poor fluidity, generally causing prolonged inflammation, anti-angiogenesis, and delayed wound closure. Herein, it is reported that a self-pumping organohydrogel dressing (SPD) with aligned hydrated hydrogel channels, prepared by a three-dimensional-templated wetting-enabled-transfer (3D-WET) polymerization process, can efficiently drain viscous fluids and accelerate diabetic wound healing. The asymmetric wettability of the hydrophobic-hydrophilic layers and aligned hydrated hydrogel channels enable unidirectional and efficient drainage of viscous fluids away from the wounds, preventing their overhydration and inflammatory stimulation. The organogel layer can adhere onto the skin around the wounds but can be easily detached from the wet wound area, avoiding secondary trauma to the newly formed tissues. Taking a diabetic rat model as an example, the SPD can significantly downregulate the inflammation response by ≈70.8%, enhance the dermal remodeling by ≈14.3%, and shorten wound closure time by about 1/3 compared with the commercial dressing (3M, Tegaderm hydrocolloid thin dressing). This study sheds light on the development of the next generation of functional dressings for chronic wounds involving viscous biofluids.

Chemical Design of Supramolecular Reversible Adhesives for Promising Applications.

Supramolecular reversible adhesives have garnered significant attention due to their potential applications in various fields. These adhesives exhibit remarkable properties such as reversible adhesion, self-healing, and high flexibility. This concept aims to present a comprehensive overview of the current research progress in developing supramolecular reversible adhesives. Firstly, the fundamentals of supramolecular chemistry and the principles underlying the design and synthesis of reversible adhesive systems are discussed. Next, the concept focuses on characterizing the reversible adhesion strength of supramolecular adhesive systems that have been developed. The adhesion performance of supramolecular reversible adhesives is summarized, highlighting their unique characteristics and promising applications. Finally, the challenges and future perspectives in the field of supramolecular reversible adhesives are discussed. The comprehensive overview provided in this concept aims to inspire further research and innovation in this exciting field.

Assembly and Utility of a Drawstring-Mimetic Supramolecular Complex.

Inspired by the drawstring structure in daily life, here we report the development of a drawstring-mimetic supramolecular complex at the molecular scale. This complex consists of a rigid figure-of-eight macrocyclic host molecule and a flexible linear guest molecule which could interact through three-point non-covalent binding to form a highly selective and efficient host-guest assembly. The complex not only resembles the drawstring structure, but also mimics the properties of a drawstring with regard to deformations under external forces. The supramolecular drawstring can be utilized as an interlocked crosslinker for poly(methyl acrylate), and the corresponding polymer samples exhibit comprehensive enhancement of macroscopic mechanical performance including stiffness, strength, and toughness.

Facile synthesis of Ag lattice doped mesoporous In2O3 nanocubes for high performance ethanol sensing.

Ag lattice doped In2O3 with a mesoporous structure was synthesized through a combination of hydrothermal and calcination methods. The structural and morphological characteristics were assessed using XRD, SEM, TEM, TGA, BET, and XPS analyses. Gas sensing measurements revealed that the 7.0 mol% Ag-doped In2O3 sensor displayed a response of 420 towards 100 ppm ethanol at 140 °C, which was 19 times higher than that of the pure In2O3 gas sensor. Density functional theory calculations indicated that Ag-doped In2O3 exhibited enhanced adsorption performance, higher adsorption energy, and electron transfer, resulting in higher sensitivity to ethanol. These findings were also supported by the electronic band structure, work function, and DOS analyses. These results indicated that the Ag doped mesoporous In2O3 has high potential for the preparation of high-performance ethanol sensors in practical applications.

Co-doped RuO2 nanoparticles with enhanced catalytic activity and stability for the oxygen evolution reaction.

Efficient and durable electrocatalysts for the oxygen evolution reaction (OER) play an important role in the use of hydrogen energy. Rutile RuO2, despite being considered as an advanced electrocatalyst for the OER, performs poorly in stability due to its easy oxidative dissolution at very positive (oxidizing) potentials. Herein, we report a type of Co-doped RuO2 nanoparticle for boosting OER catalytic activity and stability in alkaline solutions. The replacement of Ru by Co atoms with a lower ionic valence and smaller electronegativity can promote the generation of O vacancies and increase the electron density around Ru, thus enhancing the adsorption of oxygen species and inhibiting the peroxidative dissolution of RuO2 during the OER process. It was found that Ru0.95Co0.05Oy exhibited excellent OER performance with overpotentials as low as 217 mV at 10 mA cm-2 and 290 mV at 100 mA cm-2 in 1 M KOH, as well as outstanding stability in continuous testing for 50 h at a current density of 100 mA cm-2, and nearly no significant degradation after the accelerated durability test of 2000 cycles.

Bimetallic metal-organic framework-derived bamboo-like N-doped carbon nanotube-encapsulated Ni-doped MoC nanoparticles for water oxidation.

Molybdenum carbide materials with unique electronic structures have received special attention as water-splitting catalysts, but their structural stability in the alkaline water electrolysis process is not satisfactory. This study reports an in situ pyrolysis method for preparing NiMo-based metal-organic framework (MOF)-derived chain-mail oxygen evolution reaction (OER) electrocatalysts and bamboo-like N-doped carbon nanotube (NCNT)-encapsulated Ni-doped MoC nanoparticles (NiMoC-NCNTs). The NCNTs can provide chain mail shells to protect the inner highly reactive Ni-doped MoC cores from electrochemical corrosion by the alkaline electrolyte and regulate their catalytic properties through charge redistribution. Benefiting from high N-doping with abundant pyridinic moieties and abundant active sites of the periodic bamboo-like nodes, the as-prepared NiMoC-NCNTs display an outstanding activity for the OER with an overpotential of 310 mV at 10 mA cm-2 and a superior long-term stability of 50 h. Density functional theory calculations reveal that the excellent electrocatalytic activity of NiMoC-NCNTs comes from the electron transfer from NiMoC nanoparticles to NCNTs, resulting in a decrease in the local work function at the carbon surface and optimized free efficiencies of OER intermediates on C sites. This work provides an effective approach to improve the structural stability of fragile catalysts by equipping them with carbon-based chain.

Construction of n-type homogeneous to improve interfacial carrier transfer for enhanced photoelectrocatalytic hydrolysis.

Photoelectrocatalyzed hydrogen production plays an important role in the path to carbon neutrality. The construction of heterojunctions provides an ideal example of an oxygen precipitation reaction. In this work, the performance of the n-n type heterojunction CeBTC@FeBTC/NIF in the photoelectronically coupled catalytic oxygen evolution reaction (OER) reaction is presented. The efficient transfer of carriers between components enhances the catalytic activity. Besides, the construction of heterojunctions optimizes the energy level structure and increases the absorption of light, and the microstructure forms holes with a blackbody effect that also enhances light absorption. Consequently, CeBTC@FeBTC/NIF has excellent photoelectric coupling catalytic properties and requires an overpotential of only 300 mV to drive a current density of 100 mA cm-2 under illumination. More importantly, the n-n heterojunction was found to be effective in enhancing charge and photogenerated electron migration by examining the carrier density of each component and carrier diffusion at the interface.

Evidence for the transportation of aggregated microplastics in the symplast pathway of oilseed rape roots and their impact on plant growth.

As an emerging contaminant, microplastics are absorbed by crops, causing diverse impacts on plants. Plants may have different physiological responses to different uptake modes of microplastics various stage of growth. In this study, the distribution of polystyrene (PS) microspheres in the roots of oilseed rape and the physiological responses at different growth stages were investigated by confocal laser scanning microscope, scanning electron microscopy, and biochemical analysis. This study, conducted via scanning electron microscopy, discovered that agglomerates of microspheres, rather than individual plastic pellets, were taken up by plant roots in solution for the first time. The agglomerates subsequently migrate into the vascular bundles of the root system. Moreover, this study provided the proof for the first time that PS is transported in plants via the symplast system. On the physiological and biochemical function, the exposure of PS at the flowering and bolting stages caused oxidative stress on oilseed rape. That is, the addition of PS with different particle sizes significantly increased peroxidase (POD), malondialdehyde (MDA), photosynthetic rate, chlorophyll content and inhibited superoxide dismutase (SOD) content in oilseed rape at different developmental stages. These changes regulated the chloroplast structure and chlorophyll synthesis, maintained a high photosynthetic rate, and mitigated the toxicity of PS. In addition, correlation analysis showed that MDA and citric acid contents were significantly positively correlated with chlorophyll contents (p < 0.05), which suggested that the 80 nm PS treatment stimulated organic acid secretion in oilseed rape at the bolting stage to maintain a higher chlorophyll content. This study expands the current understanding of the effects of microplastics on crop growth, and the results holding significant implications for exploring the impact of microplastics on vegetables during various developmental stages and for future risk assessment.

MOF-derived S-doped NiCo2O4 hollow cubic nanocage for highly efficient electrocatalytic oxygen evolution.

Inducing the surface reconstruction of spinels is critical for improving the electrocatalytic oxygen evolution reaction (OER) activity. Herein, S-doped NiCo2O4 hollow cubic nanocage was synthesized by anion etching Metal-Organic Frameworks (MOFs) template and air annealing strategies. The hollow structure possesses a large specific surface area and pore size, facilitating active site exposure and mass transport. S2- doping regulates the electronic structure, reducing the oxidation potential of Ni sites during the OER process, thus promoting the surface reconstruction into γ-NiOOH active species. Meanwhile, S2- doping enhances conductivity, accelerating interfacial charge transfer. As a result, S-NiCo2O4-6 exhibits superior OER activity (262 mV overpotential @ 10 mA cm-2) and stability in 1.0 M KOH solution. Furthermore, 20 % Pt/C‖S-NiCo2O4-6 only needs 1.832 V to achieve 50 mA (the electrochemical active area is 4 cm2) in a homemade anion exchange membrane (AEM) electrolyzer. This work proposes a novel approach for preparing efficient anion-doped spinel-based OER electrocatalysts.

Electro-oxidation and UV irradiation coupled method for in-site removing pollutants from human body fluids in swimming pool.

A comprehensive study was conducted to investigate how ultraviolet (UV) irradiation combined with electrochemistry (EC) can efficiently remove human body fluids (HBFs) related pollutants, such as urea/creatinine/hippuric acid, from swimming pool water (SPW). In comparison with the chlorination, UV, EC, and UV/chlorine treatments, the EC/UV treatment exhibited the highest removal rates for these typical pollutants (TPs) from HBFs in synthetic SPW. Specifically, increasing the operating current of the EC/UV process from 20 to 60 mA, as well as NaCl content from 0.5 to 3.0 g/L, improved urea and creatinine degradation while having no influence on hippuric acid. In contrast, EC/UV process was resilient to changes in water parameters (pH, HCO3-, and actual water matrix). Urea removal was primarily attributable to reactive chlorine species (RCS), whereas creatinine and hippuric acid removal were primarily related to hydroxyl radical, UV photolysis, and RCS. In addition, the EC/UV procedure can lessen the propensity for creatinine and hippuric acid to generate disinfection by-products. We can therefore draw the conclusion that the EC/UV process is a green and efficient in-situ technology for removing HBFs related TPs from SPW with the benefits of needless chlorine-based chemical additive, easy operation, continuous disinfection efficiency, and fewer byproducts production.

Theoretical Study on Spectrum and Luminescence Mechanism of Cy5.5 and Cy7.5 Dye Based on Density Functional Theory (DFT).

Cy5.5 and 7.5 are the most commonly used NIR 2-region fluoresceins, which have good luminescence properties and important biomedical tracer applications. In this paper, their molecular non-covalent interactions, UV-Vis absorption spectra, main bond lengths, electrostatic potential distributions, frontier molecular orbitals (HOMO and LUMO) and energy gaps were calculated by density functional theory (DFT). We found that the differences in the luminescence properties and energy gaps of Cy5.5 and Cy7.5 molecules may be caused by the length of the conjugated chains between the two aromatic rings in the molecule. By calculating the relevant molecular characteristics, this paper can provide ideas and theoretical basis for the relevant modification and application, as well as the development of new fluorescent dyes.