Search

• Adult zebrafish are more sensitive to F-53B than embryos, with a lower 96 h LC50. • F-53B exposure impairs the gill structure of zebrafish. • F-53B exposure leads to an increase in erythrocyte numbers in zebrafish. • F-53B decreases egg production and increases the GSI in zebrafish. • F-53B disrupts steroidogenic gene expression and sex hormone production in zebrafish. 6:2 Chlorinated polyfluorinated ether sulfonate, commonly known as F-53B, is widely used as a mist suppressant in various industries and is frequently detected in the environment. Despite its prevalent presence, the adverse effects of F-53B are not well understood and require future investigation. This study utilized zebrafish embryos and adults to examine the toxic effects of F-53B. Our findings revealed that F-53B impaired gill structure and increased erythrocyte numbers in adult zebrafish. Notably, F-53B demonstrated a higher sensitivity for inducing mortality (LC 50 at 96 h) in adult zebrafish compared to embryos. Additionally, F-53B disrupted the expression of critical steroidogenic genes and hindered sex hormone production, which negatively affecting egg production. In conclusion, this study underscores the detrimental impact of F-53B on gill structure and reproductive toxicity in zebrafish, providing valuable insights into its overall toxicity. [ABSTRACT FROM AUTHOR]

Repetitive self-healing is important for ensuring the long-term effectiveness of cementitious materials. However, research on in-situ preservation and carbonisation of ammonia water (NH 3 ∙H 2 O) to enhance repetitive self-healing of ammonium bicarbonate (NH 4 HCO 3) has not yet been conducted. Attempted to strengthen the preservation and carbonisation of NH 3 ∙H 2 O with superabsorbent polymer (SAP) and modified biochar (BC) in this study. Capturing carbon dioxide (CO 2) and preserving NH 3 ∙H 2 O were maximally achieved and multidimensionally analysed. Physical characteristics were found to be vital in the physicochemical mechanism of CO 2 capture. Through modifications involving acid, alkali, urea, and deionised water in various types of BC (bamboo, corn straw, rice husk ash), rice husk ash was sensitive to pore structure and specific areas whereas bamboo was insensitive to physical characteristics. Furthermore, the optimised particle size range of SAP was selected through a stable equilibrium water absorption rate, achieving maximum retention of NH 3 ∙H 2 O repeatedly. Subsequently, composite artificial aggregates (CAAs) were prepared by appropriately mixing BCs, SAPs, and NH 4 HCO 3 to accelerate carbonisation. 7 % CAAs minimised autogenous shrinkage within 60 days, while 5 % CAAs maximised the healing percentage after 60 days, further elaborating on the unifying healing relationship between the individual and the entirety. • Multidimensional analysis identified sensitive factors of BCs in absorbing carbon. • The stable equilibrium water absorption rate of SAPs maximised NH 3 ∙H 2 O retention. • Increased the regeneration potential of NH 4 HCO 3 through SAPs and BCs. • CAA mitigated shrinkage and enhanced repetitive self-healing simultaneously. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biodegradable microfiber materials for sustainable air filtration were developed. • A novel fiber toughening strategy inspired by earthworms was proposed. • The mechanical properties of microfiber materials were significantly improved. • The filter materials have suitable filtration efficiency and low pressure drop. Fully renewable and biodegradable polylactic acid (PLA) microfiber filters are attractive candidates for traditional unsustainable filters due to their unique advantages of maintaining mechanical strength while in service and rapidly degrading after waste. However, the toughness of sustainable PLA melt-blown microfibers (PLAMFs) with high polymeric chain orientation is poor, which makes it difficult to meet the requirements of air filtration applications. Here, a facile but effective polymeric chain limited domain rearrangement (PLR) strategy inspired by earthworms is developed to toughen PLAMFs. In this process, the short-time and high-temperature heat treatment can quickly break the original hydrogen bonds between polymeric chains and form new ones, which stimulates the thermal movement of polymeric chains from the low entropy position to the high entropy position, resulting in the intrinsically toughening of PLAMFs while maintaining strength. The resulting PLR-PLAMFs and PLR PLA melt-blown nonwovens (PLR-PLAMNs) exhibit enhanced toughness of 146.32 MJ m−3 (an increase of 143.99 %) and 0.80 MJ m−3 (an increase of 66.67 %), respectively. Moreover, toughened PLA melt-blown nonwovens (PLAMNs) after corona electret (CE) treatment exhibit high filtration efficiency (>90.00 % PM 0.3 removal) and extremely low pressure drop (<0.02 % atmospheric pressure), which is highly promising for application in sustainable air filtration. [ABSTRACT FROM AUTHOR]

[Display omitted] [ABSTRACT FROM AUTHOR]

The small time-step due to the small size of microcapsules using the discrete element method (DEM) requires a significant number of computations when analyzing the force condition of microcapsules for mixing self-healing concrete. In this study, a speed-up method with a reduced Young's modulus is proposed to correct the particle contact force after establishing the relationship between the maximum contact force and the Young's modulus of particles in the collision process by using theoretical derivations and data fitting. The proposed method was verified using a stirred box model with the DEM and a stirred tank model with computational fluid dynamics–DEM. The effects of different particle numbers, impeller speeds, and time-step sizes on the accuracy of the proposed method were investigated. The results demonstrated the feasibility of analyzing the maximum contact force between particles using the speed-up method with a reduced Young's modulus. [Display omitted] • The relationship between maximum contact force and Young's modulus was obtained. • A speed-up method for CFD-DEM simulation of contact force was proposed. • The applicability and accuracy of the speed-up method was verified. • The computational efficiency was significantly improved due to the speed-up method. [ABSTRACT FROM AUTHOR]

Early-age creep of seawater sea sand concrete has a profound effect on construction engineering. This study investigates the ramifications of seawater and sea sand on the early-age creep behavior of concrete subjected to different compressive stresses. To discern the impact of seawater and sea sand on deformation, creep tests were conducted. In parallel, mechanical tests, shrinkage deformation tests, and capillary water absorption tests were conducted to elucidate the influence of seawater and sea sand on macroscopic performance. Moreover, mercury intrusion porosimetry and scanning electron microscopy were deployed to scrutinize the concrete's pore structure and microstructure. The findings reveal that seawater and sea sand precipitate augmented shrinkage and creep deformations in concrete, with seawater exerting a more pronounced effect. Furthermore, seawater and sea sand diminish the porosity of concrete, optimizing its pore structure by curtailing the count of large pores and augmenting the number of gel pores and capillary pores, thereby bolstering its durability. Seawater also reduces the critical stress threshold for the manifestation of nonlinear creep in early-age concrete, while sea sand exerts a minimal influence. These insights hold substantial implications for comprehending the influence of seawater and sea sand on the early-age creep of concrete and offer valuable guidance for their practical deployment in engineering projects. • Creep in seawater sea sand concrete under varying stress levels was investigated. • Seawater exerted a more pronounced effect of shrinkage and creep deformations. • Seawater curtailed large pores, and augmented gel pores and capillary pores. • The seawater's pronounced effect on durability of concrete was revealed. [ABSTRACT FROM AUTHOR]

High-performance analysis of heavy metal ions is great importance in both environment and food safety. In this work, a facile and reliable colorimetric sensor was presented for simultaneous detection of Cu2+ and Cr3+ based on indicator-displacement assay (IDA). As a typical silicate nanomaterials, ZnSiO 3 hollow nanosphere (ZSHS) exhibited an outstanding ion exchange capacity. Zincon was incorporated with the ZSHS to form a zincon/ZSHS hybrid ionophore with a blue color. Upon the addition of Cr3+, IDA reaction and selective ion exchange occurred with the color change of zincon/ZSHS ionophore from blue to yellow. With such a design, colorimetric measurement of Cr3+ was realized. The linear concentration for Cr3+ detection ranged from 0.5 μM to 75 μM with the LOD of 83.2 nM. Furthermore, we also screened different kinds of complexing agents that may respond with zincon/ZSHS ionophore and various metal ions. It was found that tartaric acid (TA) showed the chelation capability of Zn2+-TA is stronger than that of Zn2+-zincon. Thus zincon/ZSHS/TA presented a yellow color due to the chelation reaction of Zn2+-TA, releasing the zincon as a free state. After addition of Cu2+, a stronger chelation reaction of Cu2+-zincon occurred. This process involved in the color change from yellow to blue and realized colorimetric measurement of Cu2+. The detection limit of Cu2+ was calculated to be 43.7 nM with linear range from 0.1 to 20 μM. In addition, the zincon/ZSHS nanoprobe was successfully applied for simultaneous measurement of Cu2+ and Cr3+ in sorghum and river water, indicating that the zincon/ZSHS nanoprobe provided a promising sensing platform in environment and food safety. Image 1 • ZSHS were introduced for colorimetric measurement of Cr3+ and Cu2+ within 5 min. • ZSHS exhibited an outstanding ion exchange capacity to Cr3+. • Tartaric acid was successfully screened to overcome the disadvantages of traditional IDA-strategy in selectivity. [ABSTRACT FROM AUTHOR]

In this study, direct detection of fluazinam was realized using a fluorescent sensor using disulfide quantum dots (MoS 2 QDs) via inner filter effect (IFE). The maximum excitation of as-prepared MoS 2 QDs presented a complementary spectral-overlap with the maximum absorption of fluazinam. Thus the occurrence of inner filter effect led to the significant fluorescence quenching of MoS 2 QDs. Additionally, fluorescent quenching efficiency of MoS 2 QDs could be enhanced by the effects of π-π stacking, hydrogen bond and electrostatic interaction between fluazinam and MoS 2 QDs, and these non-chemical bond responses also promoted the selectivity for fluazinam detection. Under the optimum conditions, the IFE-based fluorescent sensor exhibited a relative wide linear range from 50 nM to 25 μM with the LOD of 2.53 nM (S/N = 3). In addition, a paper-based sensor was established by cross-linking the MoS 2 QDs into cellulose membrane for naked-eyed detection and digital analysis of fluazinam. The paper-based sensor presented a liner range from 10 μM to 800 μM for fluazinam detection with the LOD of 2.26 μM. Additionally, the acceptable recoveries were obtained for fluazinam detection in the spiked samples of tomato, potato and cucumber, indicating that the proposed method provided an effective sensing platform for real applications of fluazinam detection in food safety. Image 1 • MoS 2 QDs were introduced as fluorescent readout for measurement of fluazinam. • A paper-based sensor was developed using MoS 2 QDs for fluazinam detection. • Nake-eyed and digital readout were realized by an IISV system. • This strategy presented a model to develop fluorescence sensors based on IFE. [ABSTRACT FROM AUTHOR]

[Display omitted] • CRISPR/Cas12a was used for colorimetric and fluorescent dual-identification of MRSA. • Our approach provides a universal platform for diagnosing various pathogenic microorganisms. • CRISPR/Cas12a and AuNPs-DNA probe enable rapid on-site pathogen detection. Accurate identification of Staphylococcus aureus (S. aureus) is crucial for food safety and clinical diagnosis. Particularly, identifying drug-resistant strains guides effective treatment and prevention of infectious diseases. Herein, we presented a highly efficient programmable CRISPR/Cas12a system for identification of methicillin-resistant S. aureus (MRSA). Genus-specific gene (spec gene) and methicillin-resistant gene (mecA gene) of S. aureus were amplified by PCR. According to the sequences of spec gene and mecA gene, corresponding programmable crRNAs were designed and prepared to construct CRISPR/Cas12a system, which recognized and bound to the PCR products through complementary interactions to activate the trans -cleavage activity of Cas12a. This led to the indiscriminate digestion of surrounding FQ-reporter, releasing a distinct fluorescence signal for MRSA identification. In addition, we devised a pair of AuNPs-DNA probes for colorimetric recognition of S. aureus. Target-triggered trans -cleavage for linker probe led to an non-aggregation of AuNPs-DNA probes pair. This led to a noticeable appearance of red color, enabling naked-eye detection. Thus, MRSA identification was realized with remarkable sensitivity and exceptional selectivity. Successful identification of MRSA in clinical samples validated the practical applications of the proposed CRISPR/Cas12a assay, establishing it as a universal platform for diagnosing pathogenic microorganisms with versatility and compatibility. [ABSTRACT FROM AUTHOR]

[Display omitted] • AgNTs@AuNHs with Ag nano-triangle core and Au nano-hexagonal shell was firstly synthesized. • AgNTs@AuNHs has strong surface plasmon resonance. • AgNTs@AuNHs can be etched by Pb2+ and Cu2+ in the presence of Na 2 S 2 O 3. • AgNTs@AuNHs is applied for simultaneous detection of Pb2+ and Cu2+. A colorimetric gold nanohexagonals coated silver nanotriangles (AgNTs@AuNHs) nanoprobe has been constructed for the ultrasensitive detection of trace Pb2+ and Cu2+, based on the fact that Pb2+ and Cu2+ as the catalyzer can selectively enhance the etching rate of AgNTs@AuNHs by S 2 O 3 2−. In the presence of Pb2+, the inner AgNTs within the AgNTs@AuNHs undergo complete etching to form the hollow AuNHs, leading to the marked decrease in both absorbance and chrominance at 585 nm. In contrast, Cu2+ initiates an etching reaction on the AgNTs, subsequently extending to the AuNHs. These transformations give rise to the formation of hollow gold nanotriangles, accompanied by pronounced red-shifts in the absorption peaks of the detection system. The distinct optical responses induced by Pb2+ and Cu2+ in the AgNTs@AuNHs nanoprobe enable the sensitive and selective detection and quantification of these heavy metal ions. Furthermore, we successfully extracted RGB data from the color changes of AgNTs@AuNHs nanoprobe, enabling a straightforward visual readout for detection of Pb2+ and Cu2+. This method yields satisfactory recoveries when applied to the analysis of Pb2+ and Cu2+ in river water, rice, and onion samples, with detection results closely matching those obtained using ICP-MS. These results collectively underscore the practical applicability of the AgNTs@AuNHs nanoprobe. [ABSTRACT FROM AUTHOR]

• Mechanical properties of T9, T11, and T14 are calculated by molecular dynamics. • Deformation process of tobermorite is investigated through uniaxial tensile test. • T9 shows the strongest loading resistance compared to T11 and T14. • Water in the interlayer region decrease the tensile resistance of tobermorite. The calcium silicate hydrate (C-S-H) structure has been indicated its atomic structure in the early stage of hydration resembles the geometry of tobermorite which is a natural calcium silicate hydrate. The mechanical properties of tobermorite crystals were investigated based on molecular dynamics (MD) method in this study. Uniaxial tension simulation in the z-direction was performed to the layered structure of tobermorite 9 Å, 11 Å and 14 Å at molecular level. The stress–strain relationships were obtained, and the structure analysis of tobermorite was carried out in terms of the relative concentration profile and mean square displacement. It has been found that tobermorite 9 Å has the greatest tensile strength compared with tobermorite 11 Å and 14 Å. It also shows that strong interaction between interlayer Ca ions and silicon-oxygen tetrahedra will increase the resistance of tensile loading. These findings may contribute to have a deep knowledge of the intrinsic property of C-S-H. [ABSTRACT FROM AUTHOR]

Gemcitabine (GEM) is commonly used as the first-line chemotherapeutic agent for treating pancreatic cancer (PC) patients. However, drug resistance is a major hurdle in GEM-based chemotherapy for PC. Recent studies have shown that pyroptosis, a type of programmed death, plays a significant regulatory role in cancer development and therapy. In this study, we observed an increase in the expression of Caspase-1 (CASP1)/ Gasdermin-D (GSDMD) in PC and found that high expression of CASP1 and GSDMD was associated with poor overall survival (OS) and progression-free survival (PFS) of PC patients. Knockdown of either CASP1 or GSDMD resulted in the inhibition of cell viability and migration in PC cells. More importantly, the knockdown of CASP1 or GSDMD enhanced GEM-induced cell death in PC cells. Interestingly, subsequent investigations demonstrated that enzymatically active CASP1 promoted GEM-induced cell death in PC cells. The activation of CASP1 by the DPP8/DPP9 inhibitor (Val-boroPro, VbP) increased GEM-induced cell death by inducing pyroptosis. These findings suggest that inhibiting CASP1 to suppress its oncogenic effects or activating it to promote cell pyroptosis both enhance the sensitivity of PC cells to GEM therapy. [ABSTRACT FROM AUTHOR]

• Stress singularity, displacement and strain discontinuities were described by XFEM. • Crack propagation criterion for heterogeneous materials was proposed. • Failure pattern of microcapsule including rupture or debonding were realized. • Predictive model for microcapsule cracking was proposed based on XFEM and ML. The cracking behavior of microcapsules in cement-based self-healing materials is essential for releasing healing agents during crack healing. In this study, the extended finite element method and machine learning were combined to predict the competitive behavior of microcapsule debonding and rupture. The fracture criterion based on energy was developed to investigate the interaction of the crack and microcapsule for heterogeneous materials. The artificial neural network was trained on 1031 datasets from extended finite element method (XFEM) simulations, and the mean square error (MSE) was 3.7E-3 and the overall R 2 was 0.94 in 16 epochs. With the proposed model, the cracking behavior of microcapsules can be judged accurately and instantly without extensive computation, which can help clarify the release condition of healing agents encapsulated in microcapsules so as to guide the design of intelligent composite materials. [ABSTRACT FROM AUTHOR]

In this study, self-healing cementitious materials based on urea-formaldehyde microcapsules were investigated. Electrochemical impedance spectroscopy tests were conducted on specimens with a single crack and a model describing the relationship between the impedance parameters and the degree of damage was established by equivalent circuit fitting. The model was applied to multi-crack specimens that were representative of actual engineering conditions and the coefficients of the model of the multi-crack specimens were determined. Based on this model, the trends of the repair rate for different self-healing times were obtained. The dynamic elastic modulus of all the specimens was tested for verifying the reliability of this model, and the repair rate of the dynamic elastic modulus was calculated according to a similar method. It is found that the repair rate of the dynamic elastic modulus and the damage repair rate were not uniform in value, but with a similar variation trend. The results demonstrated the reliability of the proposed non-destructive method. [ABSTRACT FROM AUTHOR]

• Microcapsules had dual effects on the mechanical properties of self-healing concrete. • With microcapsules incorporation, the chloride migration coefficient decreased obviously. • The influence on the long-term shrinkage of self-healing concrete was acceptable. • Microstructure of concrete was modified mainly due to the presence of microcapsules. • There is a need to balance the amount of microcapsules for the future practical application. Microcapsule-based self-healing concrete was used in a tunnel engineering project in the Qianhai area, Shenzhen and the concrete performance was investigated using laboratory and field tests. The physical properties of the microcapsules and the microstructure of the self-healing concrete were experimentally investigated. The effects of the microcapsules on the strength, permeability, and long-term shrinkage of the self-healing concrete were also investigated. The self-healing efficiency was evaluated using a compressive strength test and a rapid chloride migration (RCM) test. The results indicated that the self-healing functionality of the concrete containing 10% microcapsules gradually increased over time. The microcapsules had both positive and negative effects on the microstructure of the self-healing concrete. The use of the microcapsules resulted in a significant increase in the long-term shrinkage but the amount of shrinkage is acceptable for practical applications. No significant difference of the strain evolution was observed between the experimental and control groups in the field test, indicating that the use of microcapsule-based self-healing concrete is feasible and promising to improve the durability of concrete structures, especially in coastal civil engineering. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials are widely produced and applied in biological and environmental fields because of their outstanding physical and chemical properties, which pose a threat to the safety of living organisms and the ecological environment. Therefore, understanding how carbon nanomaterials and their derivatives work on organisms is becoming important. In recent years, more and more researchers have explored the damage of carbon nanomaterials to organisms at the molecular level. This review pays special emphasis on how proteins response to the main carbon nanomaterials (fullerene, carbon nanotubes, graphene and their derivatives). In addition, how to use the interaction between carbon nanomaterials and proteins to do some beneficial things for human and the development of safe nanomaterials is simply discussed. Finally, some suggestions have been made to lay a theoretical foundation for future research. Unlabelled Image • Fullerene and their derivatives exhibit different effects on the structure or activity of the proteins • Both positive and negative impacts of CNTs on proteins were summarized. • The interactions of graphene and its derivatives with proteins are reviewed. [ABSTRACT FROM AUTHOR]

• Cracked mortar specimens subjected to dry-wet cycles in chemical solutions. • The softening trend of the specimens increased after dry-wet cycles. • A certain distinction existed in the damage degree of the specimens. • The crack propagation was perpendicular to the prefabricated crack orientation. The mechanical behaviors and failure characteristics of cracked mortar specimens subjected to dry-wet cycles in different chemical solutions were investigated in this paper. A non-penetrating crack with a certain inclination and length was prefabricated in each specimen by embedding a copper sheet when casting mortar and then removing it when the mortar initially set. Through our experiments, the stress-strain curve, peak strain and strength, crack position and crack orientation, failure characteristics and damage degradation mechanisms of cracked mortar specimens were measured and analyzed. To identify the degree of damage deterioration of the specimens, the damage variable was expressed in terms of changes in elasticity. The tests showed that the peak strength initially decreased and then increased with the continuous increase of the inclination angle. A remarkable weakening trend occurred in the specimens subjected to dry-wet cycles in different chemical solutions. The initial crack location, orientation and failure features of the cracked specimens were not affected by the chemical solutions and dry-wet cycles, but the crack inclination angle had very significant effect. The microcrack initiation of cracked specimens occurred earlier after dry-wet cycles than under natural condition, and the time of the microcrack extension after dry-wet cycles was longer than it was under the natural state. [ABSTRACT FROM AUTHOR]

Abstract Let M be an n (> 2) -dimensional closed orientable submanifold in an (n + p) -dimensional space form R n + p (c). We obtain an optimal upper bound for the second eigenvalue of a class of elliptic operators on M defined by L T f = − div (T ∇ f) , where T is a general symmetric, positive definite and divergence-free (1 , 1) -tensor on M. The upper bound is given in terms of an integration involving tr T and | H T | 2 , where tr T is the trace of the tensor T and H T = ∑ i = 1 n A (T e i , e i) is a normal vector field associated with T and the second fundamental form A of M. Furthermore, we give the sufficient and necessary conditions when the upper bound is attained. Our main theorem can be viewed as an extension of the famous "Reilly inequality". The operator L T can be regarded as a natural generalization of the well-known operator L r which is the linearized operator of the first variation of the (r + 1) -th mean curvature for hypersurfaces in a space form. As applications of our main theorem, we generalize the results of Grosjean [17] and Li–Wang [20] in codimension one to arbitrary codimension. [ABSTRACT FROM AUTHOR]

Abstract High-performance measurement of methyl parathion (MP) is of great importance in both agricultural and environmental surveillance. Herein, we presented a facile fluorescent biosensor to indirectly measure MP using N-doped carbon dots (N-CDS) based on the inner filter effect (IFE). Methyl parathion was employed as the substrate of alkaline-catalytic hydrolysis, and p-nitrophenol (p-NP) was obtained by rapid the hydrolysis reaction under strong alkaline conditions without enzymes. Interestingly, the absorption band of p-NP appeared at 403 nm, which presented an overlapping spectrum with the excitation of N-CDs (410 nm). Due to its strong molar absorptivity, p-NP played the part of a powerful absorber in IFE to influence the excitation of fluorophore (N-CDs). Through the competitive absorption, the fluorescence intensity of N-CDs decreased extremely. With optimum conditions selected, the fluorescent sensor presented a concentration-dependent fluorescent response (ΔF) to MP ranging from 0.075 to 15 ppm (R2 =0.9956). The limit of detection was calculated to be 1.87 ppb (S/N = 3) with good selectivity. Successful measurement of MP in spiked river water and apple samples demonstrated that as-proposed optical sensor provided an alternative strategy for real applications in environmental and food safety control. Graphical abstract fx1 Highlights • N-doped carbon dots were innovatively introduced as fluorescent signal readout for measurement of methyl parathion. • This strategy realized the quantitative analysis for MP via enzyme-free process rather than enzymatic hydrolysis of MP. • This work could serve as a good model for the design of new fluorescence biosensors based on inner filter effect. • MP was successfully measured in river water and apple sample with high selectivity and satisfactory detection limit. [ABSTRACT FROM AUTHOR]

• DAA has both repetitive self-healing and autonomous compensation for shrinkage. • The dual functions of DAA are both independent and synergistic of each other. • Increasing available extracted calcium by the extrinsic supplement. A difunctional artificial aggregate (DAA) was developed to address autogenous shrinkage caused by self-desiccation of concrete during early hydration in this study. Through in-situ combination with a tri-component healing agent, comprising ammonium acetate CH 3 CCONH 4 , ammonium bicarbonate NH 4 HCO 3 , and ammonium carbamate NH 2 COONH 4 , repetitive self-healing for cracks can be achieved. The expansion product can provide additional free calcium to enhance the self-healing process. Compensatory self-healing is triggered by exposing the internal tri-component to over-expansion, where both expansion compensation and repetitive self-healing are independent but interact with each other. At a 2% DAA dosage, appropriate compensation for hydration expansion was achieved while maintaining specimen volume integrity. The compensatory self-healing of the 4% group was effective for 60 days, while the 8% group exhibited the lowest self-desiccation effect and densest pore structure. In the twice self-healing experiment involving the 0% and 2% groups, various measurements were taken to evaluate healing efficiency, including sound velocity, compressive strength, and quantitative characterisation of calcium carbonate (CaCO 3). Results showed a higher healing rate for the second self-healing compared to the first (167.13%, 37.76%, and 12.4% compared to 146.05%, 23.36%, and 7.2%, respectively). This confirmed that the self-healing efficiency increased with the regeneration of NH 4 HCO 3 , which increased with the number of self-healings. [ABSTRACT FROM AUTHOR]

In this study, experimental investigations were conducted on the self-healing potential of concrete. Sulfoaluminate based expansive agents (CSA), crystalline admixture (CA), and calcium hydrogen phosphate were used as part of cementitious materials, and porous ceramsites served as the carrier for sodium carbonate solution. The quantification of the widths/areas of the cracks was performed to examine the feasibility of the approach and optimize mix proportions. A gas permeability test was conducted on two preferred mixes to investigate the change in the gas permeability of pre-cracked samples. After curing in still water for 28 d, the pre-cracked specimens with ceramsites containing sodium carbonate, and appropriate dosages of additives exhibited considerable efficiency in surface crack closure and healing in gas permeability. The SEM results indicated the deeper formation of healing products (CaCO 3 ) in the cracks of the suggested mix when compared to that in the control mix. A healing mechanism was discussed based on the experimental results. [ABSTRACT FROM AUTHOR]

A new type of microcapsule based on n-octadecane core and poly(melamine-formaldehyde)/silicon carbide (PMF/SiC) shell was designed for near-infrared light harvesting, light-heat conversion, thermal energy storage and heat-transfer enhancement. A series of hybrid microcapsules were successfully synthesized through in situ polymerization in an oil-in-water emulsion stabilized by sodium salt of styrene-maleic anhydride copolymer and SiC synergistically. The scanning electron microscopic investigation revealed that the microcapsules presented regular spherical morphology. The chemical compositions and crystalline structures of the resultant microcapsules were characterized by energy-dispersive X-ray, Fourier transform infrared spectroscopy and X-ray powder diffraction, confirming that SiC nanoparticles have been embedded in the PMF shell. Thermogravimetric analysis and a temperature-regulated test indicated that the prepared microcapsules possessed high thermal stability and good thermoregulating ability. Differential scanning calorimetry examination showed that the resulting hybrid microcapsules can maintain high effective core content and high encapsulation efficiency, and the supercooling crystallization was obviously suppressed after the incorporation of nano-SiC. Compared with PMF microcapsules, thermal transfer properties of the PMF/SiC microcapsules were significantly improved, and the thermal conductivity increased by 60.34% after the addition of 7% nano-SiC. Furthermore, the synthesized hybrid microcapsules effectively absorbed near-infrared light and demonstrated good photothermal conversion performance under light radiation. [ABSTRACT FROM AUTHOR]

• Small particle size PE-MP and PS-MP inhibited Chlorella vulgaris colony formation. • PS-MP inhibited colony formation compared with PE-MPs exposure. • PS-MP decreased the photosynthetic pigment contents in Chlorella vulgaris. • High concentration of PE-MP decreased the photosynthetic efficiency and TSP contents. • Chlorella vulgaris could be colonized on microplastics. Microplastics, plastic particles and fragments smaller than 5 mm are ubiquitous in various aquatic environments, but the hazards of microplastics with different particle sizes, concentrations and materials are not well understood. This study investigated the toxicity of polyethylene microplastics (PE-MPs) with different concentrations and particle sizes or polystyrene microplastics (PS-MPs) on freshwater algae Chlorella vulgaris Beij (C. vulgaris) for 11 days. Results indicated that the growth, colony formation, photosynthetic pigment contents and soluble intracellular polysaccharides were unaffected, whereas the photosynthetic efficiency and the total soluble protein (TSP) contents were remarkably decreased at 11 d with the increased concentration of PE-MP exposure. The growth, photosynthetic efficiency, soluble intracellular polysaccharides and TSP contents were unaffected after exposure to PE-MPs with different particle sizes or PS-MPs. By contrast, the colony formation and photosynthetic pigment contents were remarkably decreased after exposure to PS-MPs compared with the control or PE-MPs with the same particle size. The C. vulgaris colonization on microplastics was proven by scanning electron microscopy, indicating that the adsorption effects were the main harmful pathways of different microplastics to algal. Our results suggested that microplastics have limited harmful effects on algae, mainly in adsorption and shading. [ABSTRACT FROM AUTHOR]

• A microcapsule fiber-reinforced cement-based composite was prepared. • The best combination of mechanical properties is obtained by range analysis. • The microcapsule content is the main factor influencing the mechanical properties. • SEM/EDS confirmed that the composite has self-healing capacity. This study combined the microcapsule self-healing system with fiber reinforced concrete (FRC), and investigated the effects of microcapsule content, mineral admixture type, mineral admixture content, and fiber type on tensile and compressive strength, ductility, and self-healing properties of the fiber-reinforced microcapsule self-healing cementitious composites by the orthogonal test method. For the uniaxial tensile and cubic compression tests, the optimum tensile strength group consists of a 2.2 mass ratio of GGBS, PE fiber, and no microcapsules. The optimum compressive strength group consists of a 2.2 mass ratio of GGBS, hybrid fiber, and no microcapsules. Microcapsule content and fiber type are the main factors affecting tensile properties, and an increase in the microcapsule content will reduce the tensile strength and compressive strength of the matrix. The optimum tensile strain group consists of 10% microcapsule content and a 2.2 mass ratio of GGBS and PE fiber. The results of the energy-based steady-state crack propagation test show that the fiber type is the most critical factor affecting the ductility, and the tensile ductility of the PE fiber group is higher than that of the PVA fiber group. The scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDS) diagram proved the healing effect of the fiber-reinforced microcapsule self-healing cementitious composite. [ABSTRACT FROM AUTHOR]

In this study, the vibration characteristics of composite laminated plates with variable stiffness were studied using a modal analysis experiment based on the hammering method and a free vibration attenuation experiment. Twenty-five variable stiffness laminates fabricated from carbon fiber-reinforced resin matrix composite prepregs were manufactured via an automated fiber placement process. By varying the parameters, such as the fiber angle (<0°|15°>, <15°|30°>, <30°|45°>, <45°|60°>, <60°|75°>, <74°|89°>), curve ply ratio (0, 0.5, 1), and the number of layers (8, 12, 16), these laminates were tested in a dynamic signal analyzer to obtain their modal frequency and modal damping. These parameters were observed to significantly affect the modal parameters. As experimental investigations on the vibration characteristics of variable stiffness composite laminates are very rare, this study can be considered a reference for future work. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fluorescence sensor array based on Tb@UiO-66-(COOH) 2 and Eu@UiO-66-(COOH) 2 was used to discriminate green tea samples according to fluorescence quenching effect of tea polyphenols. • Five tea polyphenols were successfully discriminated with high accuracy. • Various concentrations of Catechin Hydrate were identified precisely. • Green tea samples within different categories and grades were classified accurately. A facile and rapid fluorescence sensor array based on Tb (III) and Eu (III) doped Zr (IV) metal–organic frameworks was proposed for Chinese green tea discrimination. According to large porosity of Tb@UiO-66-(COOH) 2 and Eu@UiO-66-(COOH) 2 , phenolic hydroxyl groups of tea polyphenols could coordinate with free carboxylic acid groups and was captured into the pores, which led to the disturbance of electronic structure of ligand and inhibited the energy transfer efficiency from ligand to Tb (III) and Eu (III) center, causing the fluorescence quenching effect. Based on Hierarchy Cluster Analysis and Linear Discrimination Analysis, the fluorescence sensor array was employed for successful tea polyphenols classification through the analysis of different fluorescence quenching effect to tea polyphenols. Green tea samples within different categories and grades were also successfully discriminated using this assay according to tea polyphenols, providing a new method for Chinese green tea identification. [ABSTRACT FROM AUTHOR]

• We demonstrated that Syringaresinol can amelirate the IL-1β-stimulated ECM degradation and inflammation in mouse chondrocyte by inhibiting the NFκB pathways in vitro. In vivo, it can decrease the OARSI scores in DMM mouse models. Besides, these results mean that Syr might be a potential candidate for OA prevention and treatment. Osteoarthritis (OA) is a now regarded as a worldwide whole joint disease with synovial inflammation, cartilage degeneration, and subchondral sclerosis. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used drugs for OA treatment which only relieve the symptoms and restrain the progression of OA. However, various severe adverse effects often occur in patients with long-term NSAIDs use, which heavily burdens the healthcare system and impacts the quality of life. Therefore, it is much imperative to identify alternative drugs with increased efficacy. Syringaresinol (Syr), a naturally occurring phytochemical which belonging to the lignan group of polyphenols, shows anti-tumor and anti-oxidant activities, which to benefit human health. Studies has shown Syr can regulate the inflammatory response by modulating the secretion and expression level of cytokines IL-6, IL-8, and tumor necrosis factor (TNF)-α. it also shows the inhibitory effect on NF-κB pathway in mouse cells. In the present study, we aimed to demonstrate the anti-inflammatory effects of Syr in OA. In vitro Syr treatment in IL-1β-activated mouse chondrocytes significantly restrained the expression of NO, PGE2, IL-6, TNF-α, INOS, COX-2 and MMP-13. Moreover, it considerably ameliorated the degradation of aggrecan and collagen II. Furthermore, the phosphorylation of the NF-kB signaling pathway was significantly suppressed by Syr. Moreover, in vivo , the cartilage degeneration was attenuated and the increased Osteoarthritis Research Society International (OARSI) scores were reversed in the DMM + Syr group, comprared to those in the DMM group. In sum, our study demonstrated that Syr can attenuate the inflammation in vitro and further verified its effect on OA in vivo. Thus, Syr might be a potent therapeautic alternative for OA treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • AgNCs has a strong surface plasmon resonance. • AgNCs can be catalytically etched by Cu2+ in the presence of H 2 O 2 solution. • AgNCs nanoprobe is used for sensitive detection of Cu2+ baed on etching strategy. • Nake-eye recognition of Cu2+ can be realized with dual-singal output. In this study, an efficient and simple colorimetric method for sensing of Cu2+ was established using inhibition effect of Cu2+ to the etching reaction of silver nanocubes (AgNCs) induced by H 2 O 2. The etching reaction of AgNCs changes its morphology and absorbance with the visual appearance from yellow to colorless. On the contrary, the presence of Cu2+ can significantly inhibit the etching progress. Thus Cu2+ induces the obvious absorbance enhancement compared with AgNCs/H 2 O 2 system. This design realizes colorimetric detection of Cu2+ based on the inhibition effect of etching reaction using AgNCs nanoprobe. The colorimetric response of AgNCs nanoprobe in ΔAbs 417.5 shows the linearity with the increasing concentrations of Cu2+ from 0.01 to 40 μM with good selectivity. The concentration limit of Cu2+ efficaciously discriminated by the naked eye is as low as 0.01 μM. Furthermore, the Euclidean distance (ED) of the difference map in RGB change before and after response with Cu2+ is applied for further visualization recognition of Cu2+. All the above results indicate the outstanding practicability and accuracy of the proposed assay for Cu2+ sensing. [ABSTRACT FROM AUTHOR]

Lithium ion batteries (LIBs) for high performance require separators with auspicious reliability and safety. Keeping LIBs reliability and safety in view, microporous polyacrylonitrile (PAN)/polyurethane (PU) nonwoven composite separator have been developed by electrospinning technique. The physical, electrochemical and thermal properties of the PAN/PU separator were characterized. Improved ionic conductivity up to 2.07 S cm −1 , high mechanical strength (10.38 MPa) and good anodic stability up to 5.10 V are key outcomes of resultant membranes. Additionally, high thermal stability displaying only 4% dimensional change after 0.5 h long exposure to 170 °C in an oven, which could be valuable addition towards the safety of LIBs. Comparing to commercialized polypropylene based separators, resulting membranes offered improved internal short-circuit protection function, offering better rate capability and enhanced capacity retention under same observation conditions. These fascinating characteristics endow these renewable composite nonwovens as promising separators for high power LIBs battery. [ABSTRACT FROM AUTHOR]

The separation of oil and water is a worldwide challenge due to the ever-increasing amount of oily industrial wastewater and polluted oceanic waters, as well as the increasing frequency of oil spill accidents. As the leader of advanced fibrous materials, electrospun nanofibers combine the properties of tunable wettability, large surface area, high porosity, good connectivity, fine flexibility, and ease of scalable synthesis from various materials (polymer, ceramic, carbon, etc.), and they hold great potential for many emerging environmental applications, including the separation of oily wastewater. In this review, the recent progress in the design and fabrication of electrospun nanofibrous materials with tunable surface wettability for oil/water separation applications is summarized and highlighted. This review covers the research and development starting from the design concepts and the synthesis of nanofibrous sorbents, nanofibrous membranes, and nanofibrous aerogels for effective oil/water separation. The review concludes with a brief forecast of challenges and future directions in this rapidly expanding field. [ABSTRACT FROM AUTHOR]

Concerns over global climate change have led to strong research emphasis worldwide on reducing the emission of greenhouse gases like CO 2 . One avenue for carbon emission reduction is using CO 2 capture and storage from industrial sources. Having low toxicity and low vapor pressure and being resistant to oxidation, natural amino acids could be a better choice over current carbon capture materials. In this study, we pioneered a unique phase change amino acid salt solvent concept in which amino acid salt solution was turned into a CO 2 -rich phase and a CO 2 -lean phase upon simple bubbling with CO 2 and most importantly, this solution captured the most CO 2 (∼90%) in the CO 2 -rich phase. Bicarbonate was found to be dominant in the CO 2 -rich phase, which had a high CO 2 loading capacity and good regenerability and cycling properties. Such a phase change amino acid salt solvent may provide unique solutions for industries to reduce CO 2 and other harmful emissions. [ABSTRACT FROM AUTHOR]

• A self-healing system was investigated in different humidity environments. • Excellent healing efficiency was achieved using the self-healing system. • Self-healing system reduced drying shrinkage and mechanical strength. • Healing mechanism of the super absorbent polymer under wet-dry cycle was explored. Super absorbent polymers, which allow better moisture retention within cracks for extended periods, can be beneficial in facilitating the autogenous self-healing process of concrete incorporated with carbonate-built lightweight aggregates. In the present study, the combined effect of super absorbent polymers and mineral additives, the calcium source provider, on the self-healing properties of self-healing lightweight concrete was investigated. In addition to determining the effect on compressive strength and drying shrinkage, a destructive test by flexural strength and a non-destructive test through electrical impedance spectroscopy were conducted to evaluate self-healing efficiency under different curing regimes. The results showed that the strength was increased by adding mineral additives, while it decreased with increasing the dosage and size of super absorbent polymers. In addition, the application of super absorbent polymers has significantly improved the healing efficiency, especially by 56.1% with adding the large size of super absorbent polymers in the wet-dry cycle. Furthermore, through the analysis of electrical impedance spectroscopy, the super absorbent polymers of large particle size were proved to have excellent moisture retention within cracks in the wet-dry cycles. According to microscopic observation, the potential mechanism was proposed that the swollen super absorbent polymers were possible to further improve self-healing efficiency in the wet environment. [ABSTRACT FROM AUTHOR]

• Triaxial behavior of microcapsule-based concrete was investigated. • The effect of microcapsules on triaxial strength declined with confinement pressure. • Microcapsules improved the plastic capacity and post-peak bulk modulus of concrete. • Concrete behavior under large axial strain was controlled by granular skeletons. To promote the application of microcapsule-based self-healing concrete in engineering structures, it is important to study the mechanical behaviour under complex stress conditions. Accordingly, this study aims to investigate the mechanical behaviour of microcapsule-based self-healing concrete under the triaxial compression state with large axial strain. The self-healing concrete was prepared by mixing different dosages of UF/Epoxy microcapsules, and the influence of confinement pressure, large axial strain, and microcapsule dosage on the mechanical behaviour of concrete was investigated through uniaxial compression, conventional triaxial compression, and mercury intrusion porosimetry (MIP) test. The results show that incorporating microcapsules reduced the cohesive strength and internal friction angle of the concrete. In contrast, the influence of microcapsule dosage on triaxial strength was rapidly weakened with increasing confinement pressure. Both the incorporation of microcapsules and the application of confinement pressure can improve the plastic deformation capacity and reduce the brittleness of the specimens. In addition, microcapsules may increase the bulk modulus of the specimens in the hardening stage. It should be noted that under the action of triaxial loading with large axial strain, the ultimate strengths of specimens with different microcapsule dosages are similar, and concrete behaviour is mainly controlled by the granular skeleton. [ABSTRACT FROM AUTHOR]

• DE-71 affected the locomotor activity without impaired secondary motoneurons. • DE-71 decreased the ACh contents in zebrafish larvae. • DE-71 exposure impaired the calcium homeostasis in zebrafish larvae. • Calcium channel agonist mitigated the locomotor impairment induced by DE-71. Polybrominated diphenyl ethers (PBDEs) can induce neurotoxicity, but the mechanism of their toxicity on the cholinergic system and locomotion behavior remains unclear. In this paper, zebrafish embryos were exposed to DE-71 (0, 1, 3, 10, 30, and 100 µg/L) until 120 h post fertilization, and its effects on the behavior and cholinergic system of zebrafish larvae and its possible mechanism were investigated. Results indicated a general locomotor activity impairment in the light-dark transition stimulation without affecting the secondary motoneurons. However, with the extension of test time in the dark or light, the decreased locomotor activity was diminished, a significant decrease only observed in the 100 µg/L DE-71 exposure groups in the last 10 min. Furthermore, whole-body acetylcholine (ACh) contents decreased after DE-71 exposure, whereas no changes in NO contents and inducible nitric oxide synthase activity were found. The expression of certain genes encoding calcium homeostasis proteins (e.g., grin1a, camk2a , and crebbpb) and the concentrations of calcium in zebrafish larvae were significantly decreased after DE-71 exposure. After co-exposure with calcium channel agonist (±)-BAY K8644, calcium concentrations, ACh contents, and locomotor activity in the light-dark transition stimulation was significantly increased compared with the same concentrations of DE-71 exposure alone, whereas no significant difference was observed compared with the control, indicating that calcium homeostasis is involved in the impairment of cholinergic neurotransmission and locomotor activity. Overall, our results suggested that DE-71 can impair the cholinergic system and locomotor activity by impairing calcium homeostasis. Our paper provides a better understanding of the neurotoxicity of PBDEs. [ABSTRACT FROM AUTHOR]

Highlights: [•] Innovative fabrication of nanofiber-net-binary structured chitosan membrane. [•] Solution–structure relationships were established. [•] Polyethyleneimine/chitosan based quartz crystal microbalance sensors were studied. [•] Rapid response and low detection limit of 5ppm for formaldehyde were presented. [Copyright &y& Elsevier]

[Display omitted] • This is the first time for a novel nitrogen-doped carbon dots for "turn-on" sensing of ATP based on AIEE effect. • The proposed method exhibited easy preparation of CDs, quick response (3 min) and wide range of linear rage (1–2000 μM). • The sensor reveals great potential application to ATP in real sample analysis. In this work, a nitrogen-doped carbon dots (CDs) was successfully synthesized by hydrothermal synthesis of polyethylenimine (PEI) and citric acid. The as-prepared CDs suffered from aggregation-caused quenching (ACQ) with a high concentration, but after adding adenosine triphosphate (ATP), the CDs aggregated. The generation of aggregates caused the rotation of the surface groups on CDs and reduced the non-radiation decay. The QY of CDs in water was 9.25 %, and increased to 16.60 % and 63.38% in the addition of 100 and 1000 μM ATP. And then, the enhancement of the radiation rate led to the aggregation induced enhancement effect (AIEE). Moreover, we also found that the proportion of precursors for CDs synthesis was a key factor in the occurrence of AIEE. Therefore, such CDs would be excellent candidates as fluorescent probes for the label-free detection of ATP. Our proposed method exhibited simple and easy preparation of nanoprobe, quick response (3 min), wide range of linear rage (1–2000 μM) and eco-friendly. In addition, the method performed successfully as a "turn-on" sensor for detection of ATP in the tablet with a recovery of 100.1~106.9% and RSD below 3.5%. [ABSTRACT FROM AUTHOR]

Abstract: Since 2006, a rapid development has been achieved in a subject area, so called electro-spinning/netting (ESN), which comprises the conventional electrospinning process and a unique electro-netting process. Electro-netting overcomes the bottleneck problem of electrospinning technique and provides a versatile method for generating spider-web-like nano-nets with ultrafine fiber diameter less than 20nm. Nano-nets, supported by the conventional electrospun nanofibers in the nano-fiber/nets (NFN) membranes, exhibit numerious attractive characteristics such as extremely small diameter, high porosity, and Steiner tree network geometry, which make NFN membranes optimal candidates for many significant applications. The progress made during the last few years in the field of ESN is highlighted in this review, with particular emphasis on results obtained in the author’s research units. After a brief description of the development of the electrospinning and ESN techniques, several fundamental properties of NFN nanomaterials are addressed. Subsequently, the used polymers and the state-of-the-art strategies for the controllable fabrication of NFN membranes are highlighted in terms of the ESN process. Additionally, we highlight some potential applications associated with the remarkable features of NFN nanostructure. Our discussion is concluded with some personal perspectives on the future development in which this wonderful technique could be pursued. [Copyright &y& Elsevier]

Highlights: [•] Innovative amino acid (AA) and AA-complex based solid sorbents were developed for CO2 capture. [•] Complexed AA had improved AA water solubility and higher CO2 adsorption capacity. [•] The factors affecting CO2 adsorption properties were investigated. [•] AA sorbents could eliminate corrosion concerns and retain AA’s unique properties. [ABSTRACT FROM AUTHOR]

Abstract: A red-clay core from north of New Zealand contains a 21cm-thick layer of the 340thousand-year old Rangitawa ash. Uranium and thorium isotope measurements on this core show that ash continuously contributes to sediments overlying the ash layer, ranging from ~58% immediately above the ash to ~8% at the core top. Rather than from an upward bioturbation or subsequent volcanic eruptions, the ash in sediments is most likely sourced from suspended Rangitawa ash in the nepheloid layer that has steadily re-deposited at the core site ever since the Whakamaru super-eruption. We suggest that this lateral transport bears important influence on interpreting marine sediment proxy records. [Copyright &y& Elsevier]

Biomimetic nanofibrous scaffolds mimicking important features of the native extracellular matrix provide a promising strategy to restore functions or achieve favorable responses for tissue regeneration. This review provides a brief overview of current state-of-the-art research designing and using biomimetic electrospun nanofibers as scaffolds for tissue engineering. It begins with a brief introduction of electrospinning and nanofibers, with a focus on issues related to the biomimetic design aspects. The review next focuses on several typical biomimetic nanofibrous structures (e.g. aligned, aligned to random, spiral, tubular, and sheath membrane) that have great potential for tissue engineering scaffolds, and describes their fabrication, advantages, and applications in tissue engineering. The review concludes with perspectives on challenges and future directions for design, fabrication, and utilization of scaffolds based on electrospun nanofibers. [ABSTRACT FROM AUTHOR]

Abstract: Cellulose nanowhiskers as a kind of renewable and biocompatible nanomaterials evoke much interest because of its versatility in various applications. Herein, for the first time, a novel controllable fabrication of spider-web-like nanoporous networks based on jute cellulose nanowhiskers (JCNs) deposited on the electrospun (ES) nanofibrous membrane by simple directly immersion-drying method is reported. Jute cellulose nanowhiskers were extracted from jute fibers with a high yield (over 80%) via a 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)/NaBr/NaClO system selective oxidization combined with mechanical homogenization. The morphology of JCNs nanoporous networks/ES nanofibrous membrane architecture, including coverage rate, pore-width and layer-by-layer packing structure of the nanoporous networks, can be finely controlled by regulating the JCNs dispersions properties and drying conditions. The versatile nanoporous network composites based on jute cellulose nanowhiskers with ultrathin diameters (3–10nm) and nanofibrous membrane supports with diameters of 100–300nm, would be particularly useful for filter applications. [Copyright &y& Elsevier]

Abstract: This paper describes the detection of formaldehyde through analyses of the resonance frequency signal from quartz crystal microbalance (QCM) sensors coated with a novel organic–inorganic hybrid sensing coating. Nanoporous titanium dioxide (TiO2) fibers with high Brunauer–Emmett–Teller (BET) surface area (68.72m2/g) were fabricated by electrospinning a sol–gel titanium tetraisopropoxide (TIP)/polystyrene (PS) composite solution and following calcination process. Ethylene glycol (EG) dispersed TiO2 nanofibers were drop casted onto the electrode of QCM, followed by the functionalization of the sensing polyethyleneimine (PEI) on the fibers. The nanoporous TiO2 fibers covered with PEI layers worked as a highly sensitive sensing interface to provide output signal for weight changes during exposure to formaldehyde vapor. The developed formaldehyde-selective sensors exhibited rapid response and low detection limit (1ppm) at room temperature. This is because the high specific surface area of the electrospun nanoporous TiO2 fibers and efficient nucleophilic addition reaction between formaldehyde molecules and primary amine groups of PEI. Our new synthetic methodology promises to be a powerful approach to fabricating hybrid organic–inorganic nanostructures on QCM for gas sensing and chemical analysis. [Copyright &y& Elsevier]

Abstract: Let be an -dimensional () minimal Lagrangian isotropic submanifold in an indefinite complex space form. We show that the dimension of satisfies with , a positive integer. When , we give a classification of such submanifolds. [Copyright &y& Elsevier]

Abstract: A novel strategy for highly sensitive colorimetric detection of gaseous formaldehyde was developed based on Methyl Yellow-impregnated electro-spinning/netting (ESN) nylon 6 nano-fiber/nets (NFN). The sensor presented a significant reflectance intensity decreasing band at 550nm which induce the visual color changes from yellow to red after exposure to formaldehyde and allowed for the detection of formaldehyde with a low detection limit of 50ppb. Upon exposure to a series of volatile organic compounds (VOCs), only formaldehyde could induce a yellow-to-red color change observable by the naked eye, which clearly exhibited that Methyl Yellow-impregnated nylon 6 NFN membranes could act as highly selective and sensitive strips to detect formaldehyde with minor interference from other VOCs. Additionally, the colorimetric sensor showed good reproducibility under cyclic sensing experiments. Furthermore, the colorimetric responses were visualized quantitative by using a color-differentiation map prepared form converted RGB (red, green and blue) values. As-prepared Methyl Yellow-impregnated nylon 6 NFN sensor strips successfully combined with the visualized detection of color map and fascinating structure of NFN membranes, which indicated promising composite materials as a simple and economical alternative to replace the traditional formaldehyde sensors and facilitated the design and development of other label-free colorimetric sensors toward various analytes based on the NFN template. [Copyright &y& Elsevier]

Abstract: For the first time, two-dimensional (2D) gelatin nano-nets are fabricated by regulating the solution properties and several process parameters during electrospinning/electro-netting. The spider-web-like nano-nets that comprise interlinked one-dimensional (1D) ultrathin nanowires (10–35nm) are stacked layer-by-layer and widely distributed in the three-dimensional (3D) porous membranes. The final morphology of the gelatin nano-nets, including nanowire diameter, area density and pore-width of the nano-nets, is highly dependent on the solution concentration, salt concentration, kinds of solvents, applied voltage, ambient temperature and relative humidity (RH). The occurrence of rapid phase separation on the splitting-film and the formation of hydrogen bond among gelatin molecules during electro-netting are proposed as the possible mechanisms for the formation of these spider-web-like nano-nets. [Copyright &y& Elsevier]

Abstract: Here we report a novel fabrication approach to highly sensitive formaldehyde sensors by the surface modification of the electrospun nanofibrous membranes. The three-dimensional fibrous membranes comprising nanoporous polystyrene (PS) fibers were electrospun deposition on quartz crystal microbalance (QCM), followed by the functionalization of the sensing polyethyleneimine (PEI) on the membranes. The morphology and Brunauer–Emmett–Teller (BET) surface area of the fibrous PS membranes with fiber diameter of 110–870nm were controllable by tuning the concentrations of PS solutions. After PEI modification, PEI particles in clusters of varying sizes (50nm to 1.2μm) were immobilized onto the surface of the bead-on-string structured nanoporous fibers. The developed formaldehyde-selective sensors exhibited fast response and low detection limit (3ppm) at room temperature. This high sensitivity is attributed to the high surface-area-to-volume ratio (∼47.25m2/g) of the electrospun porous PS membranes and efficient nucleophilic addition reaction between formaldehyde molecules and primary amine groups of PEI. [Copyright &y& Elsevier]

Abstract: APOBEC3G (A3G) is an intrinsic antiretroviral factor which can inhibit Hepatitis B virus (HBV) replication. This antiviral activity mainly depends on A3G incorporation into viral particles. However, the mechanisms of A3G packaging into HBV particles have not been well characterized. In this paper, we demonstrated that A3G interacted with the HBV core protein (HBc) directly in co-transfected HepG2 cells using the fluorescence resonance energy transfer (FRET) approach. In addition, we further found that this interaction did not require other factors in vitro using surface plasmon resonance (SPR) technology on BIAcore 3000. While cellular RNA or viral RNA was added to A3G protein solution before flow through the BIAcore chip, the interaction was not affected. In conclusion, these results suggest the possibility that A3G is incorporated into HBV viral particles via direct binding with HBc protein. [Copyright &y& Elsevier]

Abstract: A novel formaldehyde sensor was fabricated by electrospinning deposition of nanofibrous polyethyleneimine (PEI)/poly(vinyl alcohol) (PVA) membranes as sensitive coatings on quartz crystal microbalance (QCM). The morphology of the porous three-dimensional PEI/PVA membranes comprising fibers with diameter of 40nm to 1.8μm was controllable by tuning the compositions of polymers and solvents in PEI/PVA solutions. The resultant sensors showed a fast response to formaldehyde and a linear relationship upon increasing the formaldehyde concentrations due to the reversible interaction between formaldehyde molecules and amine groups of PEI. The sensor responses were reversible and reproducible towards formaldehyde in the concentration range of 10–255ppm at room temperature. The sensitivity of fibrous membrane coated QCM sensors formed from the cosolvent of water and ethanol was three times higher than that of corresponded flat membrane coated QCM sensors when exposed to 255ppm of formaldehyde. Relative humidity in testing chamber was proved to be the key parameter to affect the sensor sensitivity. Additionally, the fibrous PEI/PVA membrane coated QCM sensors exhibited a good selectivity to formaldehyde when tested with competing vapors. [Copyright &y& Elsevier]

• CA treatment reduced the water absorption rate and crushing value of RCA. • CA treatment decreased the capillary water absorption of RCA. • CA treatment improved the resistance to chloride ion diffusion of RAC. • The micro-pores and micro-cracks in ITZ were filled by CA. The crystallizer (CA) treatment on recycled concrete aggregate (RCA) can improve its quality and further benefit the utilisation of RCA in manufacturing recycled aggregate concrete (RAC). Unfortunately, the long-term properties of RAC with CA treated RCA have not been fully explored yet. Therefore, this paper is aim to evaluate the performance of CA treatment on RCA and the durability and permeability of corresponding RAC. To achieve the goal, the permeability of RAC with different RCA replacement ratios was investigated by capillary water absorption test and rapid chloride migration test, and the effects of CA on the interfacial transition zone (ITZ) and pore structure were determined through mercury intrusion porosimetry and scanning electron microscope. The results showed that CA treatment significantly improved the chloride diffusion resistance of RAC due to the calcium silicate hydrate (C-S-H) formed by the reaction between CA treatment and calcium-rich hydrates. The formed C-S-H can partially fill the pores and micro-cracks in adhesive mortar and ITZ, compact the microstructure and reduce the pore size, thus improving the permeability of RAC. [ABSTRACT FROM AUTHOR]

Organophosphorus insecticides, which are widely used to control parasitic infections, could accumulat in the environment and organisms, and their potential toxicity is a great concern. In this study, common carp (Cyprinus carpio L.) was exposed to different concentrations of trichlorfon (0, 0.1, 0.5, and 1.0 mg/L) for 28 days. The oxidative stress in brain and liver, the neurotransmitter contents in brain, and immune responses were investigated. Results revealed more severe oxidative stress effects in liver than in brain, including significant suppressive activities of superoxide dismutase, glutathione peroxidase, and total antioxidant capacity (T-AOC); reduced glutathione content; and increased reactive oxygen species and malondialdehyde contents in liver. Meanwhile, only the T-AOC activity decreased in the brain of trichlorfon-exposed groups. For neurotransmitters, the contents of 5-hydroxyindoleacetic acid, choline, and acetylcholine were all reduced after trichlorfon exposure. In the immune responses, alkaline phosphatase activity significantly decreased, while the lysozyme content significantly increased upon exposure to trichlorfon. Meanwhile, trichlorfon significantly increased the contents of inflammatory cytokines, namely, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-12, and transforming growth factor β, and significantly decreased the IL-10 content. Moreover, histological observations showed increased numbers of melano-macrophage centers in the head kidney and spleen of exposed common carp. Taken together, the results demonstrated that trichlorfon induced more severe oxidative stresses in liver than in brain, with the presence of neurotoxicity. Trichlorfon could also affect the immune responses in common carp. • Trichlorfon induced more severe oxidative stress in the liver than in the brain. • AChE activity in the brain was inhibited after trichlorfon exposure. • Trichlorfon reduced neurotransmitters concentrations. • Trichlorfon induced inflammatory response in common carp. [ABSTRACT FROM AUTHOR]