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Insensitive energetic materials are promising in the defense weapons field. However, energetic materials still suffer from great challenges and the concern about their safety limits their utilization. In this work, insensitive energetic explosive 3,3′-diamino-4,4′-azoxyfurazan/hexahydro-1,3,5-trinitro-1,3,5-triazine (DAAF/RDX) microspheres were fabricated by self-assembly method. Rod-like DAAF/RDX was prepared by mechanical ball milling for comparison. DAAF/RDX composites with different mass ratios (90:10, 80:20, and 70:30) were obtained. The morphologies and structures of as-obtained DAAF/RDX composites were characterized by scanning electron microscopy (SEM), powder x-ray diffraction (PXRD) and fourier transform infrared spectroscopy (FT-IR). The results showed that DAAF/RDX microspheres exhibited regular shaped microspheres with sizes from 0.5 to 1.2 μm. There was no crystal transition during the modification process. The thermal properties of as-obtained materials were then evaluated by differential scanning calorimetry (DSC) and materials studio software. DAAF/RDX microspheres showed an advanced decomposition peak temperature compared with rod-like DAAF/RDX. The binding energy and peak temperature values at zero βi (TP0) of DAAF/RDX (90:10) increased by 36.77 kJ/mol, 1.6 °C, and 58.11 kJ/mol, 12.3 °C compared to DAAF/RDX (80:20) and DAAF/RDX (70:30), indicating the better thermal stability of DAAF/RDX (90:10). The characteristic drop height (H50) of DAAF/RDX (higher than 100 cm) composites was higher than that of raw RDX (25 cm), suggesting significant improvements in mechanical safety. The preparation of DAAF/RDX microspheres is promising for the desensitization of RDX and useful for the formation of other materials and future wide applications.

An experimental work is presented that aims to improve our understanding of water–rock reaction, under both neutral and acidic conditions, and its effects on the mechanical deterioration of sandstone in Chongqing, southwest China, where a lot of heritage rock statues are carved in the same strata. SCB tests were conducted to evaluate the weakening of fracture toughness of Chongqing sandstone after water and acid erosions, and a high-speed camera was employed to capture its cracking behaviors under different hydrochemical conditions. Microstructural observation was also carried out to investigate the cracking path at a micro-scale, and the chemical analyses of sandstone soaking water in a duration of up to 120 days allows to reveal the evolving process of water–rock reaction. The results show that compared to acid solutions of pH = 3 and 5, the strength weakening effect of distilled water on Chongqing sandstone is more severe. Crack propagation rates captured by the high-speed camera vary between 20 and 60 mm/s in the SCB tests. There is no significant difference in the data for dry and water-saturated samples, and the same for the samples in the two acid fluids. Yet the crack growth rates of the latter two groups are apparently greater than those of the former two. The chemical reaction between water / acid solutions and Chongqing sandstone is mainly pertinent to the cementation and grain boundaries, which weakens grain contacts and promote crack propagation. This mechanism results in a low KIC, long crack length, i.e., more tortuosity along grain boundaries, and high crack propagation rate.

Salmonella spp. is one of the most serious foodborne pathogens causing millions of infection cases annually, especially in resource-limited areas. The standard culture method (2-3 days) and current nucleic acid amplification-based testing are not suitable for on-site testing in rural areas with heavy Salmonella spp. burden. Here, we developed a colorimetric recombinase polymerase amplification (RPA) method for fast and sensitive Salmonella spp. testing in 1 h. Specifically, the invA gene from the genomic DNA of Salmonella spp. was amplified isothermally to produce double-stranded DNA (dsDNA) amplicons, which were directly quantified by a photosensitization colorimetric assay. The proposed method offered the lowest detectable concentration of 5 × 103 colony-forming units/mL (cfu/mL), which is much lower than that of ELISA (105-107 cfu/mL). The detectable limit could be further pushed down to 3 cfu/mL upon coupling with bacteria pre-enrichment for 6 h. Analysis of synthetic milk samples confirmed the high precision (90%) and specificity (95%) of the method for Salmonella spp. testing. Moreover, use of a DNA releaser could further simplify the whole testing operation. Because RPA features low-temperature amplification (25-42 °C) without the need for specific instruments and the dsDNA-based photosensitization colorimetric assay served as a simple and facile readout for RPA, our method thus allows fast and low-cost Salmonella spp. testing in food samples.

Photodynamic therapy (PDT) has been extensively investigated for decades for tumor treatment because of its non-invasiveness, spatiotemporal selectivity, lower side-effects, and immune activation ability. It can be a promising treatment modality in several medical fields, including oncology, immunology, urology, dermatology, ophthalmology, cardiology, pneumology, and dentistry. Nevertheless, the clinical application of PDT is largely restricted by the drawbacks of traditional photosensitizers, limited tissue penetrability of light, inefficient induction of tumor cell death, tumor resistance to the therapy, and the severe pain induced by the therapy. Recently, various photosensitizer formulations and therapy strategies have been developed to overcome these barriers. Significantly, the introduction of nanomaterials in PDT, as carriers or photosensitizers, may overcome the drawbacks of traditional photosensitizers. Based on this, nanocomposites excited by various light sources are applied in the PDT of deep-seated tumors. Modulation of cell death pathways with co-delivered reagents promotes PDT induced tumor cell death. Relief of tumor resistance to PDT with combined therapy strategies further promotes tumor inhibition. Also, the optimization of photosensitizer formulations and therapy procedures reduces pain in PDT. Here, a systematic summary of recent advances in the fabrication of photosensitizers and the design of therapy strategies to overcome barriers in PDT is presented. Several aspects important for the clinical application of PDT in cancer treatment are also discussed.

Two-dimensional (2D) materials, such as transition metal dichalcogenides (TMDs), black phosphorus (BP), MXene and borophene, have aroused extensive attention since the discovery of graphene in 2004. They have wide range of applications in many research fields, such as optoelectronic devices, energy storage, catalysis, owing to their striking physical and chemical properties. Among them, anisotropic 2D material is one kind of 2D materials that possess different properties along different directions caused by the intrinsic anisotropic atoms’ arrangement of the 2D materials, mainly including BP, borophene, low-symmetry TMDs (ReSe2 and ReS2) and group IV monochalcogenides (SnS, SnSe, GeS, and GeSe). Recently, a series of new devices has been fabricated based on these anisotropic 2D materials. In this review, we start from a brief introduction of the classifications, crystal structures, preparation techniques, stability, as well as the strategy to discriminate the anisotropic characteristics of 2D materials. Then, the recent advanced applications including electronic devices, optoelectronic devices, thermoelectric devices and nanomechanical devices based on the anisotropic 2D materials both in experiment and theory have been summarized. Finally, the current challenges and prospects in device designs, integration, mechanical analysis, and micro-/nano-fabrication techniques related to anisotropic 2D materials have been discussed. This review is aimed to give a generalized knowledge of anisotropic 2D materials and their current devices applications, and thus inspiring the exploration and development of other kinds of new anisotropic 2D materials and various novel device applications.

A particle-based discrete element model combined with digital image processing to take into account the grain geometry and size distribution is used to investigate the mechanical and microcracking behavior of Beishan granite (BG), a typical crystalline rock potential for nuclear waste disposal in China. First, the procedure to construct a digital image-based grain-based model is introduced. The unsupervised K-means clustering algorithm is used to determine mineral boundaries, and four micro-parameters are assigned according to the Weibull distribution to reflect micro-heterogeneity of rock. Then, the model is calibrated to the macro-properties of BG obtained from laboratory tests, and consistency between model simulation and laboratory test results of both microcracking processes and failure modes is found. It is shown that intragrain cracks are initiated successively in quartz, feldspar, and mica; and their numbers in quartz and feldspar are much more than that in mica. Crack cluster, forking cracks and cataclastic microcracking are typical in quartz, while the “voids” is found in mica. Grain property heterogeneity has a significant impact on micro-cracking behavior and macro-properties of the model, with greater heterogeneity resulting in a lower uniaxial compression strength and elastic modulus, and a more scattered distribution of microcrack inclination. The modeling procedures presented here provide an effective method for investigating mechanical and damage behavior of granites, with specific consideration of heterogeneity involving the distribution of mineral grains and their mechanical properties.

In recent years, nanomaterials and nanotechnology have emerged as vital factors in the medical field with a unique contribution to cancer medicine. Given the increasing number of cancer patients, it is necessarily required to develop innovative strategies and therapeutic modalities to tackle hypoxia, which forms a hallmark and great barrier in treating solid tumors. The present review details the challenges in nanotechnology-based hypoxia, targeting the strategies and solutions for better therapeutic performances. The interaction between hypoxia and tumor is firstly introduced. Then, we review the recently developed engineered nanomaterials towards multimodal hypoxia tumor therapies, including chemotherapy, radiotherapy, and sonodynamic treatment. In the next part, we summarize the nanotechnology-based strategies for overcoming hypoxia problems. Finally, current challenges and future directions are proposed for successfully overcoming the hypoxia tumor problems.

The exfoliation of phosphorene from black phosphorus to afford mono-elemental two-dimensional (2D) materials (Xenes) has caused a boom in various fields since 2014. Among the Xenes, an emerging class of material, 2D pnictogens, which includes phosphorene, arsenene, antimonene, and bismuthene, has drawn a great deal of attention in the field of catalysis owing to their high specific surface area, mechanical properties, biocompatibility, and optical and electrical performance. With the development of interdisciplinary research, it has become a new trend of scientific research, especially the application of catalysis in medicine, to break the barriers between disciplines and achieve multidisciplinary joint investigation. Herein, firstly, the structures, general properties, and synthetic methods of 2D pnictogen (group VA) materials are reviewed. Then, we summarize the various state-of-the-art catalytic applications of the 2D pnictogen family, such as photocatalysis, electrocatalysis, and medical catalysis, especially in terms of strategies to improve their catalytic performance, such as doping, functionalization, and heterostructures. We also shed some light on the cross-subject of photocatalytic and electrocatalytic processes for biomedical applications. Finally, we summarize the research progress, outlooks, and challenges for these 2D catalysts in terms of their catalytic performance, characterization, reaction mechanisms, exploration of new systems, and commercial applications. This review aims to highlight the catalytic effects of 2D pnictogen materials in enhancing the performance of reactions.

We have studied the photophysics of tetrafurylethene, an aggregation-induced emission luminogen with exceptionally short intramolecular O-O distances of 2.80 Å and a significant red-shifted morphochromism (27 nm) when going from the aggregate to the crystal. The short O-O distances, which are substantially smaller than the sum of the van der Waals radii (3.04 Å), are due to the fact that the oxygen atoms act as an electronic bridge connecting the furan rings on opposite ends of the central double bond, giving rise to a circular delocalization of the π-electron density across the rings. In the excited state the O-O distance is further reduced to 2.70 Å; the increased O-O interaction causes a narrowing of the HOMO-LUMO gap, resulting in the red morphochromism of the emission. Our results show the structural origin of the red-shifted emission lies in close O-O contacts, paving the way for understanding the clusteroluminescence of oxygen-rich non-conjugated systems that emit visible light.

Smart materials and surfaces with tunable functionalities are of great interest, especially for intelligent devices. However, achieving high sensitivity, fast response, simple operations and multi-response is still challenging. Here, a new strategy that utilizes the formation or dissociation of anion–π+ interactions to control the non-radiative decay of the molecules on the surface of the aggregation-induced emission (AIE) nanoparticles (NPs) is proposed for the first time. The ultrasensitive modulation of the fluorescence of the AIE NPs can be realized by a trace amount of acid. By using the AIE NPs to functionalize the silicon surface, a smart surface that possesses tunable fluorescence and wettability with an ultrafast response is obtained. Under acid vapor stimuli, multiple wetting status and wettability patterns can be precisely controlled on the AIE luminogen (AIEgen)-functionalized surface due to variation of the surface polarity. The introduced strategy is an innovative way of developing organic fluorescent NPs with tunable multi-functionalities, which can be used to develop ultrasensitive sensors and intelligent devices.

The emergence of novel two-dimensional (2D) monoelemental materials (Xenes) has shown remarkable potential for their applications in different fields of technology, as well as addressing new discoveries in fundamental science. Xenes (e.g., borophene, silicene, germanene, stanene, phosphorene, arsenene, antimonene, bismuthene, and tellurene) are of particular interest because they are the most chemically tractable materials for synthetic exploration. Owing to their excellent physical, chemical, electronic and optical properties, Xenes have been regarded as promising agents for biosensors, bioimaging, therapeutic delivery, and theranostics, as well as in several other new bio-applications. In this tutorial review, we summarize their general properties including the classification of Xenes according to their bulk properties. The synthetic and modification methods of Xenes are also presented. Furthermore, the representative Xene nanoplatforms for various biomedical applications are highlighted. Finally, research progress, challenges, and perspectives for the future development of Xenes in biomedicines are discussed.

Ammonia electro-oxidation is an extremely significant reaction with regards to the nitrogen cycle, hydrogen economy, and wastewater remediation. The design of efficient electrocatalysts for use in the ammonia electro-oxidation reaction (AOR) requires comprehensive understanding of the mechanism and intermediates involved. In this study, aggregation-induced emission (AIE), a robust fluorescence sensing platform, is employed for the sensitive and qualitative detection of hydrazine (N

To realize the multi-targets detection, tracking and identification by the dissimilar sensors fusion in the air early-warning and surveillance system, the multi-targets joint detection, tracking and recognition strategy based on the random finite set model for the dissimilar sensors fusion is studied. Through the unified description of the target’s kinematics state and target recognition attribute state, the multi-targets state is modeled as a global state described by a random finite set. By analyzing the kinematic sensor and attribute sensor models, the various sensors are modeled as a global sensor, and then each dissimilar sensor measurement is modeled as a global measurement described by a random finite set. According to the global state and the global measurement model, the process of multi-targets joint detection, tracking and recognition by dissimilar sensors fusion is described as a Bayesian filtering process, and the corresponding strategy of multi-targets joint detection, tracking and recognition has been proposed. Simulated experiment is given to prove the correctness and effectiveness of the proposed strategy.

Considering two temperature layers model of 5 kW SOFC (solid oxide fuel cell) stack not only dramatically reduces complexity of the model, but also shows the higher precision, which should be preferred in the controller design. Taylor series for the model are adopted, and then based on the static output power point, the constrained predictive controller is designed considering the fuel exhaustion and thermal constraints. The temperature and its gradient, output power, and fuel exhaustion are emphatically analyzed, which can ensure the fast power tracking and thermal safety simultaneously. Besides, the control standards of the fuel exhaustion show more rigorous compared to operating safety, which is comprehensively considered during controller design. The result shows that although power tracking process accelerated with the increase of the current regulation rate, the risk coefficient of the operating safety is increasing too.

As a high order and non-linear complex system, a control-oriented reduced order model is first designed for the 5kW solid oxide fuel cell (SOFC) system, and then its dynamic and static performances with the four temperature layers, three temperature layers, and two temperature layers are respectively discussed. Although the simulation results show some theoretical design error with the different operating points in the different temperature layer system model, including the electrical static output characteristics (V-P characteristic curve, current density distribution), thermal static output characteristic (solid layer temperature, temperature distribution at the air side), and fluid static output characteristics (H 2 O > H 2 and O 2 ), the reduced order system model can reflect the static characteristics of the SOFC stand-alone system pretty accurately. As the response curve and response time scale of dynamic output characteristics (current density, fuel cell output voltage, and system output power) tend the same in the different temperature layers model, thus it can be argued that the characteristics of the original model are very effectively retained in the reduced order model. Finally, two temperature layers model not only dramatically reduces the complexity of the model, but also shows the higher precision, which should be preferred in the controller design.

Immunomodulation of macrophages against cancer has emerged as an encouraging therapeutic strategy. However, there exist two major challenges in effectively activating macrophages for antitumor immunotherapy. First, ligation of signal regulatory protein alpha (SIRPα) on macrophages to CD47, a "don't eat me" signal on cancer cells, prevents macrophage phagocytosis of cancer cells. Second, colony stimulating factors, secreted by cancer cells, polarize tumor-associated macrophages (TAMs) to a tumorigenic M2 phenotype. Here, it is reported that genetically engineered cell-membrane-coated magnetic nanoparticles (gCM-MNs) can disable both mechanisms. The gCM shell genetically overexpressing SIRPα variants with remarkable affinity efficiently blocks the CD47-SIRPα pathway while the MN core promotes M2 TAM repolarization, synergistically triggering potent macrophage immune responses. Moreover, the gCM shell protects the MNs from immune clearance; and in turn, the MN core delivers the gCMs into tumor tissues under magnetic navigation, effectively promoting their systemic circulation and tumor accumulation. In melanoma and breast cancer models, it is shown that gCM-MNs significantly prolong overall mouse survival by controlling both local tumor growth and distant tumor metastasis. The combination of cell-membrane-coating nanotechnology and genetic editing technique offers a safe and robust strategy in activating the body's immune responses for cancer immunotherapy.

Powder dusting method is the most practically useful approach for latent fingerprint development in the crime scene. Herein, a general powder dusting method has been explored for latent fingerprint development based on aggregation-induced emission luminogens (AIEgens). A series of tetraphenylethene (TPE) derivatives with multiple diphenylamine (DPA), namely, TPE-DPA, TPE-2DPA and TPE-4DPA, were selected as candidates to dope with magnetic powders and applied for latent fingerprint development. After screening, the magnetic powder 3 doped with TPE-4DPA proves to be the best, in terms of fluorescent intensity, resolution and adhesiveness. Afterwards, the magnetic powder 3 was applied for visualization of latent fingerprint on various smooth and porous substrates, including glass, stainless steel, leaf, ceram, plastic bag, lime wall, wood and paper money. Specific details, such as island, core, termination and bifurcation, can be clearly observed for the fluorescent fingerprint images.

Nanozymes are nanomaterials exhibiting intrinsic enzyme-like characteristics that have increasingly attracted attention, owing to their high catalytic activity, low cost and high stability. This combination of properties has enabled a broad spectrum of applications, ranging from biological detection assays to disease diagnosis and biomedicine development. Since the intrinsic peroxidase activity of Fe3O4 nanoparticles (NPs) was first reported in 2007, >40 types of nanozymes have been reported that possess peroxidase-, oxidase-, haloperoxidase- or superoxide dismutase-like catalytic activities. Given the complex interdependence of the physicochemical properties and catalytic characteristics of nanozymes, it is important to establish a standard by which the catalytic activities and kinetics of various nanozymes can be quantitatively compared and that will benefit the development of nanozyme-based detection and diagnostic technologies. Here, we first present a protocol for measuring and defining the catalytic activity units and kinetics for peroxidase nanozymes, the most widely used type of nanozyme. In addition, we describe the detailed experimental procedures for a typical nanozyme strip-based biological detection test and demonstrate that nanozyme-based detection is repeatable and reliable when guided by the presented nanozyme catalytic standard. The catalytic activity and kinetics assays for a nanozyme can be performed within 4 h.

Thallium (Tl) is an extremely toxic heavy metal and exists in very low concentrations in the environment, but its sensing is largely underexplored as compared to its neighboring elements in the periodic table (especially mercury and lead). In this work, we developed a ratiometric phosphorescent nanoprobe for thallium detection based on Mn-doped ZnSe quantum dots (QDs) and water-soluble carbon dots (C-dots). Upon excitation with 360 nm, Mn-doped ZnSe QDs and C-dots can emit long-lived and spectrally resolved phosphorescence at 580 and 440 nm, respectively. In the presence of thallium, the phosphorescence emission from Mn-doped ZnSe QDs could be selectively quenched, while that from C-dots retained unchanged. Therefore, a ratiometric phosphorescent probe was thus developed, which can eliminate the potential influence from both background fluorescence and other analyte-independent external environment factors. Several other heavy metal ions caused interferences to thallium detection but could be efficiently masked with EDTA. The proposed method offered a detection limit of 1 μg/L, which is among the most sensitive probes ever reported. Successful application of this method for thallium detection in biological serum as well as in environmental water and soil samples was demonstrated.

Overexpression and crystallization of uric acid have been recognized as the course of hyperuricemia and gout, which is produced via xanthine oxidase (XOD)-catalyzed oxidation of xanthine. Therefore, the medicinal therapy of hyperuricemia and gout is majorly based on the inhibition of the XOD enzymatic pathway. The spectroscopic nature of xanthine and uric acid, namely both absorption (near the ultraviolet region) and emission (non-fluorescent) characteristics, hinders optical assay development for XOD analysis. Therefore, the state-of-the-art analysis of XOD and the screening of XOD inhibitors are majorly based on chromatography. Here, we found the near ultraviolet absorption of uric acid overlapped well with the absorption of a large bandgap semiconductor quantum dots, ZnS. On the other hand, the intrinsic weak fluorescence of ZnS QDs can be substantially improved via transition metal ion doping. Therefore, herein, we developed an inner filter effect-based assay for XOD analysis and inhibitor screening with Mn-doped ZnS QDs. The phosphorescence of Mn-doped ZnS QDs could be quenched by uric acid generated from xanthine catabolism by XOD, leading to the phosphorescence turn-off detection of XOD with a limit of detection (3σ) of 0.02 U L-1. Furthermore, the existence of XOD inhibitors could inhibit the XOD enzymatic reaction, resulting in weakened phosphorescence quenching. Therefore, the proposed assay could also be explored for the facile screening analysis of XOD inhibitors, which is important for the potential medicinal therapy of hyperuricemia and gout.

A new flavolignan acylglycoside, namely phillygenin 4-O-(2′′-trans-cinnamoyl)-α-L-rhamnopyranoside (1), along with a known phenolic acid (ellagic acid, 2) and three known flavonol glycosides (kaempferol 3-O-β-D-glucopyranoside (3), kaempferol 3-O-α-L-rhamnopyranoside (4), and quercetin 3-O-β-D-glucopyranoside (5), was isolated and purified from the fallen needles of Pinus banksiana by repeated column chromatography. The structures of these secondary metabolites were mainly elucidated by the extensive use of 1D and 2D NMR experiments, together with IR, UV, and FAB MS spectra. Among the four known compounds, 2 and 4 have never been found in this conifer species previously.

The glass transition temperature (Tg) is an important physical parameter and signifies the reversible transition process between the glassy state and the rubbery state in polymeric materials. Herein, a simple yet reliable method, denoted as ADEtect, utilizing aggregation-induced emission luminogens (AIEgens) for Tg measurement was developed. The fluorescent images of AIEgen-doped polymer films taken at different temperatures were monitored by a camera under the same settings. By using a MATLAB program, the grayscale of the selected area in each image was calculated. This value decreased steadily with increasing the temperature, and a significant change was observed at Tg. By plotting a graph of the second derivative of relative grayscale against temperature, the Tg of a polymer can be unambiguously determined from the lowest point. The present method shows performance comparable to that of conventional DSC measurement in terms of sensitivity and reliability. Besides, it can measure multiple samples in par...

Although the capability of supramolecular pseudorotaxane/rotaxane systems as ligands for coordination with actinides has been identified by the on-going emerging of uranyl-organic polyrotaxane compounds, it is, however, still unknown how supramolecular inclusion affects the coordination assembly of the simple "axle" ligand with uranyl species. Herein, a semi-rigid organic dicarboxylate compound [BzBPCEt]Br2 (L1 ) is selected as a small-molecule "axle" ligand and the corresponding cucurbit[7]uril (CB7)-based [2]pseudorotaxane ligand, [BzBPCEt]Br2 @CB7 (L1 @CB7) has been also synthesized through CB7-based inclusion in this work. A detailed comparison between uranyl complexes from the "axle" ligand L1 and those from pseudorotaxane L1 @CB7 has been conducted, demonstrating the significant role of CB7-based inclusion in distinguishing supramolecular pseudorotaxane ligands from small-molecule dicarboxylates in uranyl coordination assembly. Notably, the impact of supramolecular inclusion on the "axle" linker in the system with cucurbituril macrocycles involved is established for the first time. Detailed structure decipherment suggests that the significant effect of CB7 is attributed to hydrothermal stabilization of the "axle" ligand or increased steric hindrance to the groups nearby originated from the bulky size of macrocyclic CB7.

Phytochemical investigation of the n-BuOH fraction of the 70% EtOH extract of Juglans sigillata green husks afforded a new isoflavone triglycoside, named 3′-methoxy-5′-hydroxy-isoflavone-7-O-(2″,6″-di-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (1), along with two known epimeric ellagitannins, pedunculagin (2) and 2,3-O-4,4′,5,5′,6,6′-hexahydroxydiphenoyl-(α/β)-glucose (3). Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence.

In this study, the concentration gradient inside evaporating binary sessile droplets of 30, 50, and 60 vol % tetrahydrofuran (THF)/water mixtures was investigated. The 5 μL THF/water droplets were evaporated on a transparent hydrophobic substrate. This is the first demonstration of local concentration mapping within an evaporating binary droplet utilizing the aggregation-induced emission material. During the first two evaporation stages of the binary droplet, the local concentration can be directly visualized by the change of fluorescence emission intensity. Time-resolved average and local concentrations can be estimated by using the pre-established function of fluorescence intensity versus water volume fraction.

This work focused on the effect of NH4Cl on pretreatment of eucalyptus for xylose recovery rate. Response surface methodology (RSM) was applied to design the experiments, and the optimum pretreatment conditions were determined, resulting in 77.45% xylose recovery rate. A quadratic polynomial equation for predicting the xylose recovery rate was developed. The experimental results were in good agreement with predicted values. Composition analysis proved that NH4Cl pretreatment had a good effect on hemicellulose in eucalyptus, and the physical surface of the eucalyptus showed an apparently damaged surface after pretreatment with NH4Cl in scanning electron microscopy (SEM) images.

Daidzin (DZ) and genistin (GEN) are the main glucosidic components of soy isoflavone; the detection of DZ and GEN can provide insight for the appropriate ingestion of soy products. An indirect competitive chemiluminescence immunoassay (icCLIA) method based on N-(aminobutyl)-N-(ethylisoluminol) (ABEI) as chemiluminescent (CL) label was developed to assay DZ in soy products. Meanwhile, GEN also could be determined due to the cross reaction with DZ monoclonal antibody (MAb). Fluorescein isothiocyanate (FITC) was used to label the pure DZ antigen to compete with DZ in toy products. Magnetic beads (MBs) capped with anti-FITC antibody were both the solid phase and separator. The chemiluminescence signal produced by the emission of photons from ABEI was inversely proportional to the amount of DZ and GEN in the sample solution. The method was linear to 6000 ng/mL DZ with a detection limit of 1.34 ng/mL. The intra-assay imprecision results [mean (coefficient of variation, CV)] were less than 6%. The average recoveries ranged from 92 to 98%. The relationship between the proposed method and high-performance liquid chromatography (HPLC) exhibited a correlation. The proposed method demonstrates acceptable performance for rapid quantification of DZ and GEN and can be used to rapidly detect these substances in soy products.

The visualization of microphase separation in immiscible polymer blends is of great academic and industrial significance as the phase-separated structures are directly associated with the properties and performances of the blend materials and ultimately influence the corresponding product quality. However, conventional techniques for detecting microphase separation are generally expensive and time-consuming with troublesome and even destructive sample preparation procedures. Complicated and highly material-dependent chemical reactions or interactions are often involved in some characterization approaches. In this work, we demonstrated a simple, fast, and powerful method for high-contrast visualization and differentiation of micrometer-sized phase separation in polymer blends using luminogens with aggregation-induced emission characteristics (AIEgens) as fluorescent probes. This method relies on the sensitive fluorescence response of AIEgens to the change of environmental rigidity and polarity and operates...

Despite the prosperity of rotaxane coordination polymers with rotaxane molecules serving as main-chain linkers, side-chain metal-organic polypseudorotaxanes with mobilizable macrocyclic host molecules on the side chain have not been reported yet. Here a new type of coordiantion-driven cucurbit[6]uril-bearing side-chain polypseudorotaxanes with two-dimensional trimeric uranyl-oxalate as main chains have been synthesized through hydrothermal reaction of uranyl with a unique in situ-formed semi-hydrolytic single-ended carboxylated pseudorotaxane ligand in the presence of oaxlate coligand. Interestingly, a simple variance of substitution site of coordination groups could lead to two different supramolecular isomers. Further mechanism analysis indicated that condition-dependent hydrolysis of the cyano groups of pseudorotaxane ligand as well as the participation of oxalate group into the coordination of uranyl contributes to the formation of this new type of side-chain polypseudorotaxanes.

A mixed-ligand system provides an alternative route to tune the structures and properties of metal–organic compounds by introducing functional organic or inorganic coligands. In this work, five new uranyl-based polyrotaxane compounds incorporating a sulfate or oxalate coligand have been hydrothermally synthesized via a mixed-ligand method. Based on C6BPCA@CB6 (C6BPCA = 1,1′-(hexane-1,6-diyl)bis(4-(carbonyl)pyridin-1-ium), CB6 = cucurbit[6]uril) ligand, UPS1 (UO2(L)0.5(SO4)(H2O)·2H2O, L = C6BPCA@CB6) is formed by the alteration of initial aqueous solution pH to a higher acidity. The resulting 2D uranyl polyrotaxane sheet structure of UPS1 is based on uranyl-sulfate ribbons connected by the C6BPCA@CB6 pseudorotaxane linkers. By using oxalate ligand instead of sulfate, four oxalate-containing uranyl polyrotaxane compounds, UPO1–UPO4, have been acquired by tuning reaction pH and ligand concentration: UPO1 (UO2(L)0.5(C2O4)0.5(NO3)·3H2O) in one-dimensional chain was obtained at a low pH value range (1.47–1.89) ...

The first reversible solid-state single-crystal-to-single-crystal isomerisation mediated by the change of uranyl-ligand coordination modes, that is from seven-coordinated uranium(vi) of α-UP to six-coordinated uranium(vi) of the supramolecular isomer, β-UP, has been achieved in the uranyl polyrotaxane system by a temperature-induced strategy.

Recently, emerging 2D material‐supported metal single‐atom catalysts (SACs) are receiving enormous attention in heterogeneous catalysis. Due to their well‐defined, precisely located metal centers, unique metal–support interaction and identical coordination environment, these catalysts serve as excellent models for understanding the fundamental issues in catalysis as well as exhibiting intriguing practical applications. Understanding the correlations between metal–support combinations and the catalytic performance at the atomic level can be achieved on the SACs@2D materials nanoplatforms. Herein, recent advances of metal SACs on various types of 2D materials are reviewed, especially their exciting applications in the fields of chemicals, energy, and the environment. Based on the summary and perspectives, this work should contribute to the rational design of perfect metal SACs with versatile properties., The marriage of single metal atoms and 2D materials yields powerful nanoplatforms. The unique advantages, how to synthesize and characterize various 2D material‐supported metal single‐atoms and their diverse applications in chemical production, energy, and the environment are reviewed. The recent advances and research gaps of this emerging field are also summarized.

Nanomaterials are playing an advancing critical role in the prevention, diagnosis, and treatment of today’s human problems. By engineering with multi-active probes including biocompatible molecules, drugs, and target ligands, nanomaterials are able to inhibit or enhance the immune responses and prevent the detection ability of the immune system, thus treating autoimmune diseases. The present discussion systematically reviews the recent progress to treat autoimmune inflammation using nanomaterials of 0D, 1D, 2D, and composite systems. In addition, emphasis has laid on the using of nanomaterials-based immunotherapeutic strategies and the related autoimmune pathogenesis. Briefly discussions on current challenges and speculates on future directions have been provided to complement our drawbacks of present treatments on the basis of fascinating nanomaterials and novel nanotechnologies.

β-agonists are phenylethanolamines with different substituent groups on the aromatic ring and the terminal amino group which have the effect of nutrition redistribution and can accumulate in body tissues causing acute or chronic poisoning when consumed. Therefore, it is very important to establish a fast screening method for the detection of several kinds of β-agonists in food safety control. In this study, the aptamer-agonists (AP-Ago) has screened out by Isothermal Titration Calorimetric method. AP-Ago was a single-strand DNA with 22 base-pairs. The dissociation constant (Kd) to phenylethanolamine (PHL) was 3.34 × 10(-5)mol L(-1). The AP-Ago based electrode was constructed by self-assembling on gold electrode. A label-free electrochemical aptasensor was then developed with AP-Ago-based gold electrode, which was sensitive to phenylethanolamine(PHL), clenbuterol (CLB), ractopamine (RAC), salbutamol (SAL) and procaterol (PRO). The detection limits were 0.04 ng/mL (RAC), 0.35 pg/mL (CLB), 1.0 pg/mL (PHL), 0.53 pg/mL (SAL) and 1.73 pg/mL(PRO), respectively, The detection time was 15 min. The reproductivity of the mentioned aptasensor is good with RSD of 2.09%. Comparing with ELISA and HPLC on β-agonists detection in actual sample, this aptasensor is advantage of fewer steps and fast screen-detection of these five β-agonists or their mixtures. This study suggests that the aptasensor can be developed to a rapid screening means with multi-β-agonists (may be one or more) in sample.

The root barks of Sophora japonica L., a plant widely used in traditional Chinese medicine, were extracted with 70 % Me2CO. The antibacterial activity of the crude extracts and fractions from the subsequent purification was evaluated against two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram-negative bacteria (Klebsiella pneumonia and Escherichia coli). Further purification of the EtOAc fraction, which exhibited the strongest bacterial inhibitory activity among the resultant fractions, led to the isolation of three new acylated flavonol glycosides, quercetin 3-O-(4″-(E)-caffeoyl)-α-rhamnopyranoside (1), quercetin 3-O-(4″-(Z)-caffeoyl)-α-rhamnopyranoside (2) and kaempferol 3-O-(4″-galloyl)-α-rhamnopyranoside (3), as well as a known flavonol glycoside, kaempferol 3-O-α-arabinofuranoside (4). Structures of the isolated compounds were elucidated by spectroscopic techniques such as 1D and 2D NMR, and other chemical methods. Acylated flavonol glycosides 1–3 are new natural compounds, and their structures were elucidated here for the first time. Antibacterial study indicated that compounds 1–3 showed bacteria inhibitory effects, especially against S. aureus. Compound 3 was the most potent one, with MIC values of 25, 0.78, 6.25 and 50 μg/mL against B. subtilis, S. aureus, K. pneumonia and E. coli, respectively, while compound 4 did not exhibit antibacterial capability.

The first 3D actinide polyrotaxane framework (named IHEP-URCP-2) has been obtained based on windmill-like six-connected high-nuclear oligomeric uranyl nodes under hydrothermal conditions. Notably, the in situ formed pseudorotaxane ligand simultaneously plays dual roles of both a bulky pseudorotaxane linker and a supramolecular guest.

Traditional digital holographic imaging algorithms need multiple iterations to obtain focused reconstructed image, which is time-consuming. In terms of phase retrieval, there is also the problem of phase compensation in addition to focusing task. Here, a new method is proposed for fast digital focus, where we use U-type convolutional neural network (U-net) to recover the original phase of microscopic samples. Generated data sets are used to simulate different degrees of defocused image, and verify that the U-net can restore the original phase to a great extent and realize phase compensation at the same time. We apply this method in the construction of real-time off-axis digital holographic microscope and obtain great breakthroughs in imaging speed.

Nanobodies consist of a single domain variable fragment of a camelid heavy-chain antibody. Nanobodies have potential applications in biomedical fields because of their simple production procedures and low cost. Occasionally, nanobody clones of interest exhibit low affinities for their target antigens, which, together with their short half-life limit bioanalytical or therapeutic applications. Here, we developed a novel platform we named fenobody, in which a nanobody developed against H5N1 virus is displayed on the surface of ferritin in the form of a 24mer. We constructed a fenobody by substituting the fifth helix of ferritin with the nanobody. TEM analysis showed that nanobodies were displayed on the surface of ferritin in the form of 6 × 4 bundles, and that these clustered nanobodies are flexible for antigen binding in spatial structure. Comparing fenobodies with conventional nanobodies currently used revealed that the antigen binding apparent affinity of anti-H5N1 fenobody was dramatically increased (∼360-fold). Crucially, their half-life extension in a murine model was 10-fold longer than anti-H5N1 nanobody. In addition, we found that our fenobodies are highly expressed in Escherichia coli, and are both soluble and thermo-stable nanocages that self-assemble as 24-polymers. In conclusion, our results demonstrate that fenobodies have unique advantages over currently available systems for apparent affinity enhancement and half-life extension of nanobodies. Our fenobody system presents a suitable platform for various large-scale biotechnological processes and should greatly facilitate the application of nanobody technology in these areas.

π-Bonds connected with aromatic rings were generally believed as the standard structures for constructing highly efficient fluorophores. Materials without these typical structures, however, exhibited only low fluorescence quantum yields and emitted in the ultraviolet spectral region. In this work, three molecules, namely bis(2,4,5-trimethylphenyl)methane, 1,1,2,2-tetrakis(2,4,5-trimethylphenyl)ethane, and 1,1,2,2-tetraphenylethane, with nonconjugated structures and isolated phenyl rings were synthesized and their photophysical properties were systematically investigated. Interestingly, the emission spectra of these three molecules could be well extended to 600 nm with high solid-state quantum yields of up to 70%. Experimental and theoretical analyses proved that intramolecular through-space conjugation between the “isolated” phenyl rings played an important role for this abnormal phenomenon.

2D materials (e.g., graphene, graphene analogues), with unique physical and chemical properties, shows intriguing potential for the realization of versatile biomedical applications. Tremendous attention has been attracted on 2D material based nanocarriers, which play a crucial role in therapeutic drug, gene, and biomedical agent delivery for cancer theranostics. This review provides an up-to-date review on the development of nanocarriers based on 2D materials beyond graphene, including basic and emerging synthesis methods, the catalog of 2D material-based nanocarriers, biosafety, surface functional engineering, the realization of stimuli-responsive controllable release and biomedical applications. Among the properties and performance to be summarized, there is particular focus on nanocarriers loading capability, biosafety, and therapy efficiency and so on. Finally, by addressing major issues and challenges, some prospects for future directions in this area are provided.

Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence., Early detection and appropriate management of chronic kidney disease can reduce the progression of kidney failure and cardiovascular disease. The urine albumin to creatinine ratio (UACR) test is a standard urine test for identifying individuals at high risk of developing progressive kidney disease. In this study, IDATPE, a novel fluorescent probe with aggregation-induced emission (AIE) features, is successfully developed for creatinine detection and quantitation. An excellent correlation between fluorescent light intensity and creatinine concentration is achieved. In addition, BSPOTPE, a reported excellent AIE bioprobe for human serum albumin (HSA) quantitation, is used together with IDATPE in artificial urine for UACR testing. The mutual interference of HSA and creatinine when the bioprobes are used for quantitation is characterised, with promising results. Further improvements and potential applications in CKD quantitation are highlighted.

Crystallization induced S···S interactions leading to an unusual luminescent phenomenon., In this work we have investigated the aggregation-induced emission (AIE) behaviour of 1,1,2,2-tetra(thiophen-2-yl)ethene (tetrathienylethene, TTE). The semi-locked and fully-locked derivatives (sl-TTE and fl-TTE) have been synthesized to better understand the mechanism behind the solid state photoluminescence of TTE. TTE is a typical AIEgen and its luminescence can be explained through the mechanistic understanding of the restriction of intramolecular motions (RIM). The emissive behaviour of TTE in the THF/water aggregates and crystal state have also been studied, revealing a remarkable red-shift of 35 nm. A similar red-shift emission of 37 nm from the THF/water aggregates to the crystal state is also observed for (E)-1,2-di(thiophen-2-yl)ethene (trans-dithienylethene, DTE). Crystal analysis has revealed that the emission red-shifts are ascribable to the presence of strong sulfur–sulfur (S···S) intra- and intermolecular interactions that are as close as 3.669 Å for TTE and 3.679 Å for DTE. These heteroatom interactions could help explain the photoluminescence of non-conventional luminophores as well as the luminescence of non-conjugated biomacromolecules.

Two highly symmetrical (3,4)-connected uranyl-organic frameworks (UOFs) were synthesized by a judicious combination of D3h -symmetrical triangular [UO2 (COO)3 ]- and Td symmetrical tetrahedral tetrakis(4-carboxyphenyl)methane (H4 MTB). These two as-synthesized UOFs possess similar structural units and coordination modes but totally different topological structures, namely ctn net and bor net. Solvent-induced interpenetration and a morphology change are observed. The two compounds exhibit crystal transformation via a dissolution-crystallization process. Adsorption experiments in CH3 OH solution indicate that both of them can selectively remove positively charged dyes over negatively charged and neutral dyes. Moreover, the electronic structural and bonding properties of the two compounds were systematically explored by density functional theory (DFT) calculations.

The hierarchical assembly of well-organized submoieties could lead to more complicated superstructures with intriguing properties. We describe herein an unprecedented polyrotaxane polythreading framework containing a two-fold nested super-polyrotaxane substructure, which was synthesized through a uranyl-directed hierarchical polythreading assembly of one-dimensional polyrotaxane chains and two-dimensional polyrotaxane networks. This special assembly mode actually affords a new way of supramolecular chemistry instead of covalently linked bulky stoppers to construct stable interlocked rotaxane moieties. An investigation of the synthesis condition shows that sulfate can assume a vital role in mediating the formation of different uranyl species, especially the unique trinuclear uranyl moiety [(UO2 )3 O(OH)2 ](2+) , involving a notable bent [O=U=O] bond with a bond angle of 172.0(9)°. Detailed analysis of the coordination features, the thermal stability as well as a fluorescence, and electrochemical characterization demonstrate that the uniqueness of this super-polyrotaxane structure is mainly closely related to the trinuclear uranyl moiety, which is confirmed by quantum chemical calculations.

The Muchanghe landslide is located on the left bank of the Muchang River in Dongping reservoir, Hubei Province, China. During reservoir impoundment, cracking and dislocation deformations occurred at the front and middle parts of the Muchanghe landslide. Once the landslide was triggered, the river could be blocked, which would lead to a serious threat to upstream flood control safety. In this study, the engineering geological properties and deformation characteristics of the Muchanghe landslide during impoundment were analyzed. A 3-D limit equilibrium method was proposed for the stability analysis of this asymmetric landslide. Based on the proposed 3-D method, a visualization program (JSlope3D) was developed and applied to evaluate the stability of the Muchanghe landslide. The results indicated that the stability of the landslide gradually decreases with the rise of impounding water level in the Dongping reservoir. When the impounding water level reaches an elevation of 490 m (normal pool level), the calculated factor of safety predicted that the landslide would be in an unstable state. To prevent the generation of a landslide failure, a reinforcement scheme involving the cutting back of the slope and backfill was proposed to improve the stability of the landslide. Using the proposed 3-D method, the Muchanghe landslide, after stabilization, was stable at different impoundment water levels and can satisfy the requirements of the design specification.