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Sudden leaks often occur when constructing shield tunnels within saturated sandy cobble strata. Therefore, it is important to examine the reasons for water seepage and understand the mechanisms behind such problems. This paper presents a study that combines laser scanning technology with the Python programming language to create software for monitoring tunnel deformation. The software was employed in a practical subway tunnel scenario, successfully acquiring deformation data pertaining to the tunnel's structural segment through the analysis of point cloud data from the tunnel lining. Furthermore, the seepage-stress coupling theory was employed to establish a three-dimensional model of shield tunnel excavation, interlinking groundwater and stratigraphic factors with the sequence of shield tunnel excavation. The origins and mechanisms of water damage resulting from seepage and leakage are explicated through an examination of the seepage field, displacement field, and deformation of the tunnel structure pre- and post-excavation. Additionally, on-site monitoring data is considered. The mechanism of tunnel leakage is outlined as follows: Tunnel excavation completion induces alterations in the seepage field, leading to an accelerated inflow of groundwater into the soil beneath the tube sheet during shield excavation. The tube sheet of the shield tunnel, composed of sand and gravel layers, experiences vertical elliptical deformation that exacerbates shifts in the displacement field due to tunnel deformation's inception and progression. Excessive tube sheet deformation triggers fracture cracks, ultimately engendering the creation of seepage channels. These channels, in turn, foster seepage and water damage. The results of this paper provide a reference for preventing and remedying water infiltration and leakage in shield tunnels constructed of sandy cobble strata. [ABSTRACT FROM AUTHOR]

• A method for automatically extracting the location and area of tunnel leakage from 3D laser scanning point clouds. • Segmenting the point cloud data along the tunnel axis based on the width of the tube sheet. • Correcting the intensity of the point cloud using a linear intensity correction model. • Water leakage detection software is prepared based on the method. Water leakage is one of the common tunnel disease problems. Fast and accurate detection is crucial for timely management of leakage disease. This paper introduces a method for automatically extracting the location and area of tunnel leakage from 3D laser scanning point clouds. The method involves three key steps: segmenting the point cloud data along the tunnel axis based on the width of the tube sheet, correcting the intensity of the point cloud using a linear intensity correction model, and binarizing the point cloud data to extract the leakage area and calculate its area. To evaluate the performance of the proposed methodology, water leakage detection software is prepared based on the method, and tests are carried out in the urban subway tunnels in the leakage disease-producing sections. The results show a detection accuracy of 92 % and an improvement in detection efficiency of 7–8 times. The method proposed can be used to quickly and accurately extract the location and area of water leakage from point cloud data. [ABSTRACT FROM AUTHOR]

Abstract In order to increase the strength and lower the cost, this study experimentally investigated the effects of hooked-end steel fiber, basalt fiber and calcium sulfate on mechanical performance of polyvinyl alcohol (PVA) fiber-based engineered cementitious composite (ECC) containing high-volume fly ash. The uniaxial tensile, compression and four-point bending tests were carried out to characterize the mechanical behavior of each mixture. Scanning Electron Microscopy (SEM) image analysis and X-ray CT scan method were used to study the microstructures and distributions of pores. Test results showed that the ultimate strain capacity increases nearly linearly with the growth of stress performance index except the ECC reinforced with calcium sulfate and PVA. Hybridization with basalt fiber and PVA fiber or steel fiber and PVA fiber is more effective for improving mechanical performance within small deformation. ECC reinforced with calcium sulfate and PVA exhibits improved tensile, compressive and flexural strength while maintaining high ductility. The cost performance considering strength/cost and ductility/cost of hybrid mixtures was also discussed. Highlights • Strength performance PVA-ECC containing high-volume fly ash was improved. • Strength of the PVA-ECC was improved while maintaining the inherent high ductility by the addition of calcium sulfate. • The macro and micro effects of the addition of steel fiber, basalt fiber and calcium sulfate into PVA-ECC was discussed. [ABSTRACT FROM AUTHOR]

Proteins and polysaccharides are primary components in mammal soft tissue. In this study, we established a rapid hydrogel to imitate the nature extracellular matrix via silk fibroin (SF) and hyaluronic acid (HA) blend hydrogel. SF/HA hydrogel was prepared effectively, and its formation time was shorted. With the increase of HA content, the water absorption, porosity and breaking strengths of the hydrogel increased, while hydrophilic of the hydrogel was enhanced extremely determined by contact angle decreasing. Especially, the SF/HA hydrogel with a ratio of 5:5 presented the highest water absorption and mechanical properties. The molecule conformation of the composite hydrogel was mainly amorphous structure and contained the small number of β-sheets which gradually decreases with the increase of HA content. In drug release test, accumulative release ratio of the composite gel was about 80% at day 40. And the mass loss of the hydrogel reached approximately 78% in vitro degradation. In vivo, the SF/HA hydrogels presented good histocompatibility and promoted vascular-like tissue regeneration when were implanted subcutaneously of Sprague Dawley rats. This study provides a new approach to fabricate silk-based biomaterials for soft tissue regeneration. [ABSTRACT FROM AUTHOR]

In mountain areas, flexural buckling failure of layered rock slopes due to self-weight is common, and it frequently results in serious disasters. Previous research has focused on qualitatively evaluating slope buckling stability and rarely studied the whole process from deformation to failure. In this work, we intend to quantitatively analyze the progressive movement of buckling landslide by solving the critical buckling sliding displacement. Layered rocks are simplified as an inclined multiple beam model with axial concentrated force. The sliding process of buckling is divided into three stages, which correspond to the upper rock stress reaches tensile strength, the lower rock stress reaches compressive strength, and the rock layers below the maximum uplift height of buckling segment begin to overturn under the action of self-weight. By considering tensile and compressive strength, the calculation method of critical sliding displacement is put forward, and corresponding criterion for assessing slope buckling stability is developed. The feasibility and accuracy of the proposed method were confirmed based on the good agreement among numerical manifold simulation, theoretical calculation and field data. In addition, the parameter sensitivity analysis of layered slopes stability shows that longer, thinner, and steeper soft rock slopes are more prone to buckling failure. The formation of buckling failure will be aggravated for layered rocks with smaller compressive strength, lower geological strength index and higher degree of disturbance, but the value of critical sliding displacement remains unchanged. [ABSTRACT FROM AUTHOR]

Digital notch filters are applied to remove or suppress the narrow-band interferences in digital signals, while preserving other components unchanged. Under the condition of the identical notch bandwidths, a novel design method is put forward in this paper to realize the adaptive notch filter with infinite-impulse response (IIR). Firstly, a specially simplified all-pass filter is introduced to construct an IIR non-adaptive notch filter, which serves as the core part in the adaptive one. Secondly, the criterion of least-mean-square (LMS) is applied to design the desired adaptive notch filter (ANF). The designed ANF can track and suppress multiple non-harmonic interference components simultaneously. Finally, the effectiveness and practicability of the proposed design method are verified by a set of experimental results. [ABSTRACT FROM AUTHOR]

Abstract: A water-soluble polysaccharide (WATP), with a molecular weight of 6.3×104 Da, was isolated from Aster tataricus. According to gas chromatography (GC) analysis, WATP was composed of galactose, glucose, fucose, rhamnose, arabinose and mannose with molar ratios of 2.1:1.3:0.9:0.5:0.3:0.6. The effects of WATP on cell proliferation and apoptosis in human gastric cancer SGC-7901 cells were examined. MTT assay showed that WATP had a perfectly tumor growth inhibitory activity on SGC-7901 cells, but no cytotoxicity on SGC-7901 and primary human polymorphonuclear (PMN) cells analyzed using LDH assay. Flow cytometry analysis indicated that WATP could significantly induce apoptosis of SGC-7901 cells. Furthermore using Rh123 and Fluo-3 as fluorescent probes, respectively, it was found that mitochondrial transmembrane potential (ΔΨ m) of treatment groups was significantly lower than that in un-treatment group and the concentration of calcium in cells exposed to WATP for 24h was increased in a dose dependent manner compared with unexposed group. These results suggest that WATP induces apoptosis of SGC-7901 cells through calcium- and ΔΨ m-dependent pathways, indicating that it is potentially useful as a natural anti-cancer agent. [Copyright &y& Elsevier]

Scarless skin regeneration for full-thickness wounds remains a challenge in skin tissue engineering. The surprising scar-free repair function of fetal skin has inspired that the ideal wound dressing can be designed by recapitulating the biophysical and biochemical properties. However, there is no more powerful effective scaffold put into practice due to their mismatched structures and inappropriate components. Here, a novel bioactive scaffold was detailly designed by mimicking extracellular matrix from its chemical components and biophysical nanostructures. Through introduction of hyaluronic acid (HA) and natural silk fibroin nanofibers (SNFs), the silk fibroin (SF)-based scaffolds with higher porosity (~92.5 %), water-uptake ratio (~96 %) and swelling ratio (~90 %) were facilely prepared by lyophilization. In vitro , human umbilical vein endothelial cells (HUVECs) were seeded in the scaffold with nanostructures. The results showed better cytocompatibility of the scaffolds to support cell spread, proliferation and differentiation. In vivo , effect of the scaffolds on full-thickness skin defects of the nude mouse demonstrated that the SNFs incorporated scaffolds could not only accelerated wound healing (up to 98.2 ± 0.5 % within 4 weeks) but also can regulate collagen arrangement by nanofibers as a template to inhibit the scar forming. This study provides a useful strategy for exploring bioactive SF-based scaffolds by natural SNFs decoration for novel wound dressing and artificial skin. Schematic illustration showing the SF-HA-SNFs scaffold was fabricated into wound dressing or artificial skin to promote cell proliferation and adhesion in vitro , and enhance repair efficacy for skin tissue in vivo , which indicated a promising alternative for wound healing. [Display omitted] • Design bioactive scaffold with natural silk nanofibers (SNFs) decorated firstly. • The scaffold provided a beneficial microenvironment to improve cell growth through chemical and physical cues. • Improved repair efficacy for skin tissue defects in nude mouse was confirmed. • The bioactive scaffold has great potential for scarless reconstruction during skin repair. [ABSTRACT FROM AUTHOR]

Natural silk nanofibers (SNFs) have been attracted more attentions in flexible functional devices and biomaterials. However, its mass production and complex fabrication process remains challenging. In this study, we successfully developed a new physical-chemical strategy to fabricate natural SNFs with high yield (~87%). The natural SNFs performed an excellent dispersion in aqueous solution with uniform diameter (approximately 280 nm) and 10–30 μm length. The high-flexible natural SNFs/single-wall carbon nanotube (CNTs) composite films were prepared to evaluate their potential in electronic devices. The composite films exhibited remarkable dimensional stability, chemical durability, and Young's modulus (498.7 ± 64.4 MPa). Furtherly, the composite films also presented excellent electrical heating properties and potential utilities in electronics. These natural SNFs/CNTs composite films with high-mechanical and electrical features offer new starting materials for bioelectronics devices applications, such as conductive wire, electronical heater, and capacitor. Natural silk nanofibers/carbon nanotubes composite films with high electroconductivity and flexibility are prepared based on facile deconstruction of the silk fibroin fibers. Image 1 • It is the first time to prepare natural silk nanofibers with high yield (~87%). • The silk nanofibers are fabricated by an environment-friendly approach avoiding use of toxic agents. • The SNFs-CNTs composites exhibit good mechanical property, electrical conductivity and energy storage stability. • The SNFs-CNTs composites have versatile utilities in electronic devices. [ABSTRACT FROM AUTHOR]

Abstract: The sequential excitation energy transfer has been studied in a C16Naph(2,6)C4N+, titan yellow (TY) and fluorescein sodium (FS) ternary aqueous covesicle system. The sequential arrays of chromophores with regulated distance, orders, and orientations were constructed on a non-covalent self-organization system through amphiphilic and electrostatic interaction in aqueous media. The naphthalene group, embedded in the interior of the vesicles, TY and FS anchored on surface of the covesicles through electrostatic interaction, which were employed as donor, mediator and acceptor, respectively, based on overlapping absorption and emission spectra. The sequential energy transfer from naphthalene cascading through TY mediator to FS has been studied in the C16Naph(2,6)C4N+, TY and FS ternary aqueous covesicle system. This sequential excitation energy transfer offers a good model for photoenergy transmission system mimicking photosynthetic systems. [Copyright &y& Elsevier]

Abstract: A single chain synthetic amphiphile, 4-(5-dodecyloxynaphthalene-1-oxy) butyl trimethylammonium bromide (C12Naph(1,5)C4N+), can be self-assembled into vesicles in the dilute aqueous solution and subsequently form excimer in the vesicles. The excitation energy transfer has been performed in the C12Naph(1,5)C4N+ aqueous vesicles. The donor, naphthalene group, was embedded in the interior of the vesicles. The acceptor, titan yellow, with two negatively charged polar groups, was bound electrostatically to the positively charged surface of vesicles. The energy transfer efficiency increased with the increase of the concentration of titan yellow acceptor in the range of 0–1.2×10−5 moldm−3. Titan yellow quenched the fluorescence intensity of the naphthalene, which fitted a Stern–Volmer plot, and the Stern–Volmer quenching constant K sv is 1.75×104 dm3 mol−1. [Copyright &y& Elsevier]

The comorbidity of pain and depression is frequently observed in patients suffering from chronic pain and depression. However, the comorbid mechanism is not well elucidated and the therapeutic medication is still inadequate. Oxytocin is a neuropeptide synthesized in the hypothalamus. It has been reported to relieve chronic pain and depressive symptoms. However, the analgesic action and mechanisms of oxytocin have mainly been investigated using peripheral or spinal administration. Because of the advantage of intranasal delivery of oxytocin in crossing the blood-brain barrier, we investigated the effect of intranasal application of oxytocin on neuropathic pain and comorbid depressive symptoms in both female and male mice. In female and male mice receiving spared nerve injury (SNI) surgery, intranasal oxytocin (2.4 μg, daily for 28 days) attenuated depression-like behavior, but did not alleviate mechanical hyperalgesia. Intranasal oxytocin not only inhibited the activation of microglia and astrocytes, but also increased the downregulated oxytocin receptor (OTR) expression, reversed the elevated GluN2A, and restored the decreased BDNF expression in the hippocampus. SNI also decreased OTR expression in the spinal cord and increased spinal GluN2A and BDNF. However, intranasal oxytocin treatment did not change the expression levels of OTR, GluN2A, or BDNF in the spinal cord of neuropathic mice. The results suggest that the oxytocin signaling in the hippocampus is involved in the comorbidity of pain and depression, and intranasal oxytocin may have the potential to treat depressive symptoms in neuropathic pain patients. • Intranasal oxytocin alleviates depressive-like behavior in SNI-operated mice of both sexes. • Intranasal oxytocin reverses SNI-induced decrease in hippocampal OTR in both sexes. • Intranasal oxytocin suppresses SNI-elevated increase in hippocampal GluN2A in both sexes. • Intranasal oxytocin reverses SNI-induced decrease in hippocampal BDNF in both sexes. [ABSTRACT FROM AUTHOR]

Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO), which mediate kynurenine pathway of tryptophan degradation, have emerged as potential new targets in immunotherapy for treatment of cancer because of their critical role in immunosuppression in the tumor microenvironment. In this investigation, we report the structural optimization and structure-activity relationship studies of 1-phenyl-1 H -naphtho[2,3- d ][1,2,3]triazole-4,9-dione derivatives as a new class of IDO1/TDO dual inhibitors. Among all the obtained dual inhibitors, 1-(3-chloro-4-fluorophenyl)-6-fluoro-1 H -naphtho[2,3- d ][1,2,3]triazole-4,9-dione (38) displayed the most potent IDO1 and TDO inhibitory activities with IC 50 (half-maximal inhibitory concentration) values of 5 nM for IDO1 and 4 nM for TDO. It turned out that compound 38 was not a PAINS compound. Compound 38 could efficiently inhibit the biofunction of IDO1 and TDO in intact cells. In LL2 (Lewis lung cancer) and Hepa1-6 (hepatic carcinoma) allograft mouse models, this compound also showed considerable in vivo anti-tumor activity and no obvious toxicity was observed. Therefore, 38 could be a good lead compound for cancer immunotherapy and deserving further investigation. Image 1 • A series of 1-phenyl-1 H -naphtho[2,3- d ][1,2,3]triazole-4,9-dione derivatives were synthesized as dual inhibitors of IDO1/TDO. • Compound 38 exhibited significant activities against IDO1 (IC 50 : 0.005 μM) and TDO (IC 50 : 0.004 μM). • In LL2 and Hepa1-6 allograft models, 38 showed considerable in vivo anti-tumor activity and no obvious toxicity was observed. [ABSTRACT FROM AUTHOR]

Silk fibroin (SF) hydrogels are explored for diverse applications, ranging from cosmetic thickeners to support matrices for drug delivery and regenerative medicine. However, their utilities remain inherent challenges in inadequate mechanical properties and sophisticated process. Hyaluronic acid (HA) is a natural polysaccharide with outstanding physiological activities and superior water retaining capacity. In this study, HA was used as a skeleton of interpenetrating network to fabricate SF/HA hydrogel with high-flexibility and micro or nanofibers networks. The flexibility and water-absorbing quality of SF/HA hydrogels are improved dramatically due to super hydrophilicity of HA addition. By the synergistic effect of HA and solvent exchange, SF molecular conformation is induced efficiently to form β-sheet structures and assembling directly by physical crosslinking, which are determined by structure analysis. Moreover, the condense structure of the SF/HA hydrogel is mainly silk II, which contributes to their high thermal stability. The HA also plays a dominating role in formation of the micro or nanofibers networks on the wall of the SF/HA hydrogels, confirming by elements analysis. Investigation on fibroblast vitality and morphology showed that these SF/HA hydrogels can support cell adhesion, differentiation, and proliferation in vitro and present a better biocompatibility in comparison to pure SF hydrogel. Thus, it is believed that this work provides a facile way to fabricate protein-polysaccharide biomaterials and tissue engineering scaffolds. In this work, we report a new approach to assemble directly high-flexibility and biocompatible silk fibroin (SF)/hyaluronic acid (HA) hydrogel without chemical crosslinking. HA macromolecular chains and β-sheet content enriched contribute to the SF molecules conformational transitions and remarkable mechanical property in terms of physical crosslinking efficiently. Fibroblasts growth, morphology and viability on the hydrogels indicate good alternatives for tissue engineering. Image 1 • Composite hydrogels of silk fibroin and hyaluronic acid were fabricated by novel solvent exchange technique. • Hyaluronic acid acted as a skeleton of interpenetrating network to induce robust silk-based hydrogel formation without chemical agents. • Silk fibroin/hyaluronic acid hydrogels with nano or submicron fibers and good biocompatibility made them as expected candidates for soft tissue repair in future. [ABSTRACT FROM AUTHOR]

Abstract Bacterial infection poses great threats to human health and the emergence of drug-resistant bacteria requires effective methods to eliminate bacteria and avoid bacterial resistant. Photodynamic therapy (PDT), which applies photosensitizers (PSs) to generate reactive oxygen species (ROS) under light irradiation, has attracted widespread concern on bacterial treatment, recently. In this work, we develop a far red/near-infrared (FR/NIR)-emissive fluorescent molecule, AIE-TEA , with aggregation-induced emission (AIE) characteristics, for FR/NIR imaging and PDT of bacteria. Due to AIE characteristics and a certain degree of water dispersity, the AIE-TEA can conduct imaging of bacteria without wash process. Moreover, the AIE-TEA can effectively generate ROS under ultralow power white light irradiation (20 mW cm−2) with quantum yield of up to 83%, which is crucial for PDT of bacteria. The AIE-TEA can selectively kill Gram-positive bacteria (S. aureus) via image-guided PDT. Graphical abstract Image 1 Highlights • A FR/NIR fluorescent photosensitizer with aggregation-induced emission property. • The photosensitizer can conduct imaging of bacteria without wash process. • The photosensitizer can effectively generate ROS under ultralow power white light irradiation with quantum yield of 83%. • The photosensitizer can selectively kill Gram-positive bacteria (S. aureus) via image-guided PDT. [ABSTRACT FROM AUTHOR]

Developing long-lived room temperature phosphorescence (RTP) organic materials through simple and effective strategy is of considerable practical significance in biological imaging, optoelectronics and sensors. However, achieving efficient RTP emission of organic chromophores is challenging because of the inefficient intersystem crossing (ISC), intensive nonradiative decay and susceptible triplet excited states. Here, we present an effective strategy to obtain RTP emission of indole[3, 2- b ]carbazole derivatives via embedding the molecules in the filter paper matrix. Furthermore, t-BuOK play the role of "key" to open the close-knit hydrogen bonds of cellulose, and then the indole[3, 2- b ]carbazole derivative molecules are trapped in the filter paper matrix to realize RTP emission. The present long-lived phosphorescent systems describe an effective strategy to trigger the RTP emission of organic chromophores. [Display omitted] • Three new indole[3, 2- b ]carbazole derivatives are designed and successfully synthesized. • t-BuOK play the role of "key" to open the close-knit hydrogen bonds of cellulose. • RTP emission of indole[3, 2- b ]carbazole derivatives is obtained via embedding the molecules in the filter paper matrix. • We prepared a long-lived paper base RTP material that exhibits phosphorescence lifetimes of 1070 ms. [ABSTRACT FROM AUTHOR]

Abstract: A novel fluorescent compound, 4-(trimethyl ammonium chloride)acetamide-2-(1H-naphtho[2,3-d]imidazol-2-yl)phenol (TMACA-NIP), was synthesized and used as a fluorescent probe for detecting glutathione reduced (GSH). The new NIP-based probe exhibited high fluorescence in water, which was quenched during the presence of copper (II) due to the complexation between TMACA-NIP and Cu2+. But after adding GSH into the TMACA-NIP and Cu2+ system, the fluorescence of TMACA-NIP was recovered because the binding force between GSH and Cu2+ is stronger than that between TMACA-NIP and Cu2+, which destroys the equilibrium between NIP and copper (II) ions and releases the fluorescence probe of TMACA-NIP. This three-component competing system of NIP/Cu2+/GSH can be used to detect GSH simply and rapidly. [Copyright &y& Elsevier]

A single chain synthetic amphiphile, 4-(2-hexadecyloxynaphthalene-6-oxy)butyl trimethylammonium bromide (C16Naph(2,6)C4N+), can self-assemble into vesicles in the dilute solution. The fluorescence resonance energy transfer has been studied in aqueous vesicle solution of C12Naph(1,5)C4N+ and hydrophilic dye fluorescein sodium salt (FS). The donor, naphthalene group, was embedded in the interior of the vesicles. The acceptor, FS with two negatively charged polar groups, was bound electrostatically to the positively charged surface of (C16Naph(2,6)C4N+) vesicles. The FS quenched the fluorescence intensity of the naphthalene, which fitted a Stern–Volmer plot, and the Stern–Volmer quenching-constant K sv is 5.65×105 mol−1. The energy transfer efficiency increased with the increasing concentration of FS acceptor in the range of 0–4.4×10−6 dm3 mol−1 up to ca. 71% which could be ascribed to the ordered arrangement of chromophores inside the vesicles. [Copyright &y& Elsevier]

Mechanofluorochromic (MFC) materials display a photoluminescence color change in response to mechanical grinding and pressing. Development of an effective molecular design strategy to tune MFC activity is still challenging. Herein, seven 9, 10-distyrylanthracene (DSA)-based molecules are designed and synthesized as promising MFC materials. These molecules adopt a five-plane twisted spatial conformation that are composed of an anthryl ring and four phenyl rings. The inclusion of cyano groups and different substituents in this five-plane system causes some changes in the intramolecular charge transfer (ICT) and molecular conformation, which can directly induce new MFC activities. Among seven DSA derivatives, DSA-CN 5 exhibits the highest MFC activity upon grinding. Based on the good sensitivity and repeatability of MFC process as well as suitable stability of the ground state, DSA-CN 5 is selected to fabricate the rewritable papers and can be achieved in inkless printing technologies. [Display omitted] ● Seven new DSA derivatives are designed and successfully synthesized. ● Photophysical properties of DSA derivatives can be easily adjusted. ● DSA-CN 5 was selected to fabricate efficient rewritable papers and can be used in inkless printing technology. ● The printed content can be read distinctly both by the naked eyes and under UV lamp irradiation. [ABSTRACT FROM AUTHOR]

Biogenic amines are generally produced from the degradation of amino acids in biometabolism, which can be used as an important biomarker for food spoilage. Rapid, simple and accurate detection of biogenic amines is an important task for the food safety. Here we synthesize a series of coumarin hydrozone derivatives with high solid-state emission. BDCH2 exhibits a fluorescent switch between the yellow emission (λ em,max = 555 nm) and the NIR region (λ em,max = 720 nm) upon HCl/NH 3 vapor stimuli. The response time for NH 3 vapor is only 2 s. Utilizing this property, BDCH2 as a biogenic amine vapors sensor can be readily applied in the detection of food spoilage for real-time and visual monitoring the freshness of crawfish and fish with quick response, easy visualization and simple operation. [Display omitted] • Fluorophores exhibit concentration-enhanced fluorescence and high solid-state emission. • Fluorophore can rapid response to NH 3 vapor with fine reversibility and processability. • Fluorophore shows a rapid fluorescent switch for real-time and visual monitoring the freshness of crawfish and fish. [ABSTRACT FROM AUTHOR]

A tetraphenylethene (TPE) derivative tetra(3-1 H -benzo[ d ]imidazol-2-yl) -4-hydroxyphenyl)ethene (TBIHPE) which exhibits crystallization-induced emission enhancement (CIEE) induced by tetrahydrofuran (THF) and reversible fluorescence shifting upon HCl fuming and heating or NH 3 fuming was prepared. The CIEE and reversible fluorescence shift process were controlled by imino group and tertiary amine group of 2-(2′-Hydroxyphenyl)benzimidazole (HBI) moiety, respectively. The intermolecular hydrogen bonds between THF and imino group have been observed by single-crystal X-ray structural analysis, which changed the excited-state intramolecular proton transfer (ESIPT) process of TBIHPE, and induced the CIEE phenomena. The fluorescence emission peak of TBIHPE shows blue shift upon HCl fuming stimuli in solid state. Moreover, the fluorescence emission of HCl fumed TBIHPE solid can recover by heating or fuming in NH 3 vapors. Based on the results, the relationship between photophysical properties and protonation-deprotonation stimuli was discussed. Image 1 • We synthesized a novel tetraphenylethene derivative TBIHPE. • TBIHPE was found to be AEE-active. • TBIHPE exhibited CIEE properties. • The fluorescence emission of TBIHPE could be shifted by external stimuli. [ABSTRACT FROM AUTHOR]