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• A novel failure criterion, accounting for various degrees of concrete cracking and confinement levels, is presented to estimate the bond strength between steel rebar and concrete. • An interlock capacity coefficient, considering the surface properties of both concrete and steel rebars, is presented to adjusts concrete compressive strength. • Opening of concrete crack at the peak bond stress, alongside sliding, proves crucial to the failure criterion. • A practical computation approach is presented to estimate the bond strength of cracked RC members with commonly used confinement configurations. This study delves into the intricate relationship between concrete cracking and bond strength, a critical factor in transferring forces between concrete and steel rebars. While previous research has often overlooked the impact of concrete cracking on bond strength and overestimated the beneficial effects of external confinement, this study aims to fill these gaps. A new failure criterion is introduced to predict bond strength of steel rebar in cracked concrete, considering the influence of concrete crack roughness and steel rebar surface features on force transfer at their interface. This criterion incorporates an interlock capacity coefficient that considers crack kinematics and the mentioned factors, enhancing the evaluation of effective compressive strength of cracked concrete in the limit analysis. Leveraging the Mohr-Coulomb failure criterion, an adaptable failure criterion accounts for crack kinematics, concrete damage, and confinement level to assess force transfer at the concrete/steel rebar interface. The developed criterion offers a practical calculation method to estimate bond strength in cracked reinforced concrete (RC) members with various confinement setups. Validation of this criterion and approach involved comparison against experimental results from 127 specimens, confirming its effectiveness and reliability in predicting bond strength in real-world scenarios. [ABSTRACT FROM AUTHOR]

A self–reporting molecularly–imprinted electrochemical sensor is prepared for the detection of Zearalenone (ZEA). Firstly, the reduced graphene nanoribbons and reduced graphene oxide (rGNR–rGO) were simultaneously modified onto a glassy carbon electrode (GCE) to improve the sensor's sensitivity. After electrodepositing copper nanoparticles onto the rGNR–rGO/GCE, cyclic voltammetry scanning was performed in potassium ferrocyanide solution, and copper hexacyanoferrate (CuHCF) was deposited onto rGNR–rGO/GCE to further improve the sensor's sensitivity while giving it self–reporting capability. Then, molecularly–imprinted polymer films were prepared on the CuHCF/rGNR–rGO/GCE to ensure the selectivity of the sensor. It is found that the linear range of ZEA detection by the constructed sensor is 0.25–500 ng·mL −1, with a detection limit of 0.09 ng·mL −1. This sensor shows the merits of good selectivity, high sensitivity and accurate detection, providing a great possibility for the precise detection of low concentration ZEA in food. [Display omitted] • rGNR–rGO were co-modified onto GCE to improve the sensitivity of the sensor. • CuHCF was formed in [Fe(CN) 6 ]3−/4– solution by CV scanning CuNPs/rGNR–rGO/GCE. • CuHCF can increase sensitivity while giving the sensor self-reporting capability. • MIP is generated on the electrode by electropolymerization to improve selectivity. • The sensor has a linear range of 0.25–500 ng/mL and a detection limit of 0.09 ng/mL. [ABSTRACT FROM AUTHOR]

• CuMOFs was combined with MIP to improve the recognition ability of the sensor. • RGO was modified on GCE to improve the stability and sensitivity of the sensor. • Fe 3 O 4 can simplify the preparation process and amplify the electrochemical signal. • MMIP-CuMOFs can serve as signal probe via in situ forming copper hexacyanoferrate. • MMIP-CuMOFs/RGO/GCE exhibited excellent detection performance for bisphenol A. In this work, novel magnetic molecularly imprinted CuMOFs (MMIP-CuMOFs) were synthesized and applied to construct an electrochemical bisphenol A sensor. The constructed sensor used an electrode modified with reduced graphene oxide (RGO/GCE) as the sensing platform to improve its stability and sensitivity. The Fe 3 O 4 nanoparticles in magnetic MOFs simplified the preparation process. Moreover, the combination of CuMOFs and molecular imprinting methodology was beneficial for improving the detection specificity, and the electroactive copper hexacyanoferrate generated by the reaction of Cu2+ in CuMOFs with potassium ferricyanide was used as the signal probe. The sensor showed a good linear relationship in the range of 0.5 to 500 nmol/L, with a low detection limit of 0.18 nmol/L. In addition, the sensor had good selectivity, repeatability (RSD = 2.59 %), and a good recovery rate for actual milk sample detection (99.8–102.49 %). This technique holds great promise for the detection of detrimental substances in food. [ABSTRACT FROM AUTHOR]

[Display omitted] • Changes in the key flavor substances were elucidated during broad bean fermentation. • The core microorganisms during the fermentation process were identified. • The pathways and mechanisms for forming the key flavor substances were established. Pixian Douban (PXDB) is a popular Chinese condiment for its distinctive flavor. Broad bean fermentation (Meju) is the most important process in the formation of flavor substances. Key flavors were analyzed qualitatively and quantitatively, and metagenomic technology was applied to study the microbial diversity during broad bean fermentation. In addition, the main metabolic pathways of key flavors were explored. Results indicated that Staphylococcus_gallinarum was the main microorganism in the microbial community, accounting for 39.13%, followed by Lactobacillus_agilis , accounting for 13.76%. Aspergillus_flavus was the fungus with the highest species abundance, accounting for 3.02%. The KEGG Pathway enrichment analysis showed that carbohydrate metabolism and amino acid metabolism were the main metabolic pathways. Glycoside hydrolase and glycosyltransferase genes were the most abundant, accounting for more than 70% of the total number of active enzyme genes. A total of 113 enzymes related to key flavors and 39 microorganisms corresponding to enzymes were annotated. And Staphylococcus_gallinarum, Lactobacillus_agilis, Weissella_confusa, Pediococcus_acidilactici, Staphylococcus_kloosii, Aspergillus_oryzae, and Aspergillus_flavus played a key role in the metabolic pathway. This study reveals the formation mechanism of key flavors in fermented broad bean, it is important for guiding the industrial production of PXDB and improving product quality. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pseudomonas umsongensis GO16 is a metabolically versatile bacterium. • GO16 grows with waste-derived substrates (hydrolysed PET, glycerol, butyrate etc.) • GO16 produces a blend of short and medium chain length polyhydroxyalkanoates PHA. • PHAs are blended on the level of PHA granule in GO16. • PHA blends offer better mechanical and physical properties. Polyhydroxyalkanoates (PHAs) are biological polyesters, viewed as a replacement for petrochemical plastic. However, they suffer from suboptimal physical and mechanical properties. Here, it was shown that a metabolically versatile Pseudomonas umsongensis GO16 can synthesise a blend of short chain length (scl) and medium chain length (mcl)-PHA. A defined mix of butyric (BA) and octanoic acid (OA) in different ratios was used. The PHA monomer composition varied depending on the feeding strategy. When OA and BA were fed at 80:20 ratio it showed 14, 8, 77 and 1 mol% of (R)-3-hydroxybutyrate, (R)-3-hydroxyhexanoate, (R)-3-hydroxyoctanoate and (R)-3-hydroxydecanoate respectively. The polymer characterisation clearly shows that polyhydroxybutyrate (PHB) and mcl-PHA are produced individually. The two polymers are blended on the PHA granule level, as demonstrated by fluorescence microscopy and yeast two-hybrid assay. The resulting blend has a specific viscoelasticity compared to PHB and PHO. Mcl-PHA acts as a plasticiser and reduces PHB brittleness. [ABSTRACT FROM AUTHOR]

[Display omitted] • A molecularly imprinted electrochemical sensor for ZEA detection was developed. • O-GNRs was prepared by cutting CNTs using an improved Hummers' oxidation method. • The rGNRs and AuNPs are electrodeposited on GCE to amplify electrochemical signals. • MIP is generated on the electrode by electropolymerization to improve selectivity. • The sensor has a linear range of 1–500 ng/mL and the detection limit is 0.34 ng/mL. In this work, a highly sensitive and selective molecularly imprinted electrochemical sensor is exploited to detect zearalenone (ZEA) by the synergistic effect of reduced graphene nanoribbons (rGNRs) and gold nanoparticles (AuNPs). The oxidized GNRs are firstly produced by an improved Hummers' oxidation method, and then reduced and modified together with AuNPs onto a glassy carbon electrode by electrodeposition technique to realize collaborative amplification of electrochemical signal. The molecularly imprinted polymer film with specific recognition sites can be generated on the modified electrode by electropolymerization. The effect of experimental conditions is systematically investigated to obtain the best detection performance. It is found that the constructed sensor shows a wide linear range of 1–500 ng·mL−1 for ZEA with a detection limit as low as 0.34 ng·mL−1. Obviously, our constructed molecularly imprinted electrochemical sensor shows great potential in the application of precisely detecting ZEA in food. [ABSTRACT FROM AUTHOR]

In this paper, the effects of load ratio, elastic mismatch and plastic mismatch on the fatigue crack growth behavior of zirconium-titanium-steel composite plate are discussed in detail. Firstly, considering the crack closure effect caused by load ratio, different effective driving force models of crack tip are studied. The results show that Daniel's two parameter driving force model has the best normalization effect. Then, based on the material inhomogeneity theory, the equation of actual stress intensity factor at crack tip is obtained, and the crack growth rate equation considering elastic mismatch is obtained. Furthermore, the influence of plastic mismatch is studied. Finally, by dividing the influence area of the elastic-plastic mismatch and combining the respective crack growth criteria, the crack growth rate equation considering the load ratio and elastic-plastic mismatch is obtained. • The effects of property mismatch of composites are discussed in detail. • The influence areas of different property mismatches are divided in detail. • The crack propagation law of Zr/Ti/steel composite plate is obtained. [ABSTRACT FROM AUTHOR]

Abstract: Alzheimer’s disease (AD) is the most common cause of dementia, and currently there is no clinical treatment to cure it or to halt its progression. Aggregation and fibril formation of β-amyloid peptides (Aβ) are central events in the pathogenesis of AD. Many efforts have been spent on the development of effective inhibitors to prevent Aβ fibrillogenesis and cause disaggregation of preformed Aβ fibrils. In this study, the conjugates of ferrocene and Gly-Pro-Arg (GPR) tripeptide, Boc-Gly-Pro-Arg(NO2)-Fca-OMe (4, GPR–Fca) and Fc-Gly-Pro-Arg-OMe (7, Fc–GPR) (Fc: ferrocene; Fca: ferrocene amino acid) were synthesized by HOBT/HBTU protocol in solution. These ferrocene GPR conjugates were employed to inhibit Aβ1–42 fibrillogenesis and to disaggregate preformed Aβ fibrils. The inhibitory properties of ferrocene GPR conjugates on Aβ1–42 fibrillogenesis were evaluated by thioflavin T (ThT) fluorescence assay, and confirmed by atomic force microscopy (AFM) analysis. The interaction between the ferrocene GPR conjugates and Aβ1–42 was monitored by electrochemical means. Our results showed that both GPR and GPR–Fca can significantly inhibit the fibril formation of Aβ1–42, and cause disaggregation of the preformed fibrils. As expected, GPR–Fca shows stronger inhibitory effect on Aβ1–42 fibrillogenesis than that of its parent peptide GPR. In contrast, Fc–GPR shows no inhibitory effect on fibrillogenesis of Aβ1–42. Furthermore, GPR–Fca demonstrates significantly protection against Aβ-induced cytotoxicity and exhibits high resistance to proteolysis and good lipophilicity. [Copyright &y& Elsevier]

Abstract: The intracellular α-synuclein (α-syn) protein, whose conformational change and aggregation have been closely linked to the pathology of Parkingson''s disease (PD), is highly populated at the presynaptic termini and remains there in the α-helical conformation. In this study, circular dichroism confirmed that natively unstructured α-syn in aqueous solution was transformed to its α-helical conformation upon addition of trifluoroethanol (TFE). Electrochemical and UV–visible spectroscopic experiments reveal that both Cu (I) and Cu (II) are stabilized, with the former being stabilized by about two orders of magnitude. Compared to unstructured α-syn (Binolfi et al., J. Am. Chem. Soc. 133 (2011) 194–196), α-helical α-syn stabilizes Cu (I) by more than three orders of magnitude. Through the measurements of H2O2 and hydroxyl radicals (OHtions containing different forms of Cu (II) (free and complexed by unstructured or α-helical α-syn), we demonstrate that the significantly enhanced Cu (I) binding affinity helps inhibit the production of highly toxic reactive oxygen species, especially the hydroxyl radicals. Our study provides strong evidence that, as a possible means to prevent neuronal cell damage, conversion of the natively unstructured α-syn to its α-helical conformation in vivo could significantly attenuate the copper-modulated ROS production. [Copyright &y& Elsevier]

Abstract: Reactions between ethylenediamine solutions of K4Ge9 and triphenylindium yielded three novel Zintl ions, [In(Ge9)2]5− (1), [(Ge9)2In(C6H5)]4− (2), and [Ge9{In(C6H5)3}2}]4− (3). Species 1 exhibits an indium metal atom coordinated by two nine-atom germanium cages which bond to the central metal in an η 3-mode. The “staggered” arrangement of the two clusters confers the indium metal centre an octahedral coordination geometry. Species 2 displays trigonal planar coordination around the indium atom with an [In(C6H5)]2+ moiety acting as a bridge between the two halves of a [Ge9–Ge9]6− dimer. Finally, species 3 is composed of a [Ge9]4− deltahedral Zintl ion acting as a Lewis base to two In(C6H5)3 moieties. All three anions were characterized in the solid-state by single-crystal X-ray diffraction in [K(2,2,2-crypt)]5[1]·2en, [K(2,2,2-crypt)]4[2]·3tol and [K(2,2,2-crypt)]4[3], respectively. The existence of the anions in solution was confirmed by electrospray mass-spectrometry. DFT level calculations were also conducted on all of the cluster anions. [Copyright &y& Elsevier]

Abstract: Ferrocene (Fc) and its conjugates have attracted considerable attention in recent years due to their unique electrochemical behavior and significant biological activities such as antitumor, antimalarial, and antifungal. Arg-Gly-Asp (RGD)-containing peptides, because of their selective binding to integrins which are highly expressed in tumor-induced angiogenesis, play a key role in cancer targeted therapy. In this study, Fc–RGD and Fc–Am–RGD (Fc: ferrocenoyl; Am: 6-aminohexanoic acid) conjugates were synthesized, and the antitumor activities in vitro were investigated. The cell uptake of the conjugates by B16 murine melanoma cells was measured using HPLC-electrochemical method. The antitumor activities of the conjugates were also evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and flow cytometric measurements. The experimental results revealed that Fc–RGD and Fc–Am–RGD exhibit more effective antitumor activities than their parent compounds RGD and Fc-COOH. Moreover, it is found that Fc–Am–RGD yields the lowest IC50 values of 5.2±1.4μM toward B16 cells. The HPLC-electrochemical studies confirmed that the insertion of flexible alkyl spacer Am between Fc and RGD significantly increases the cell uptake toward B16 cells and consequently improves the antitumor activity. Our results suggest that Fc–RGD and Fc–Am–RGD conjugates are potential candidates for cancer treatment. [Copyright &y& Elsevier]

Pixian broad-bean paste (PXDB) is a traditional Chinese fermented condiment with a distinct flavor. The flavors stems from its strong relationship to local microorganisms. This study analyzed changes in key aroma compounds, organic acids, free amino acids (FAA), and the microbial community during different fermentation stages in order to study the correlation between flavors and microbes. Results indicated that the presence of key aroma compounds and organic acids initially increased, then decreased. Changes in total FAA content were divided into two stages due to the addition of chili pepper, however, both stages displayed an increase in FAA levels as fermentation time increased. High-throughput sequencing was used to study the microbial community and succession. Lactobacillus , Prevotella 9 , Ruminococcaceae ucg-014 , Lysinibacillus , Enterococcus , Weissella , Escherichia-Shigella, Sphingomonas, Aspergillus , Zygosaccharomyces , Candida, and Pichia presented as the primary microorganism during fermentation process. Simultaneously, it was found that bacteria genera indicated a stronger potential correlation with flavors, versus fungi genera. Escherichia-Shigella , Leuconostoc , Acetobacter , Chromohalobacter , Candida , Mortierella , Plectosphaerella , Podoscypha, and Podospora displayed a significant correlation with flavors (isoamyl alcohol, 2,5-dimethylpyrazine, phenethyl alcohol, 2,3,5,6-tetramethylpyrazine, citric acid, serine, asparagine, glutamate, etc.). This study provides an improved understanding on formation mechanisms of flavors, and guidance for screening PXDB fermentation strains. • Change of key aroma compounds, organic acids and free amino acids were expounded. • Eight bacterial genera and four fungal genera presented as the core microorganism. • Nine microbial genera displayed a significant correlation with main flavors. • Bacteria indicated a stronger potential correlation with flavors, versus fungi. [ABSTRACT FROM AUTHOR]

• A numerical model to predict flexural behavior of hybrid RC beams was proposed. • TCM was used to simplify the analysis of tension stiffening effect. • LSM was developed to simplify the description of softening behavior of concrete. • Simplified multilinear moment–curvature curve of hybrid RC beams was suggested. Hybrid fiber reinforced polymer (FRP)-steel reinforced concrete (RC) beams exhibit different flexural failure modes with different reinforcement ratios and the contributions from tensile region and compressive region of the beams to flexural behavior vary accordingly. Therefore, a general model to predict the global nonlinear behavior of hybrid FRP-steel RC beams featured by common flexural failure modes is critical to analysis and design. In this paper, flexural behavior of a hybrid FRP-steel RC beam is considered as the systematic combination of mechanical behavior of FRP and steel RC tension chords and concrete strut. The Tension Chord Model (TCM) for steel and its extended application for FRP, properly considering the bond performance between FRP/steel reinforcement and the surrounding concrete, are employed to represent the tension stiffening effect in tensile region; the Linear Softening Model (LSM), incorporating the compressive fracture energy and considering the confinement effect, is applied to predict the softening behavior of compressive concrete. Based on the primary principles of equilibrium and compatibility, the aforementioned two models are assembled to numerically evaluate the advanced moment–curvature relationship and flexural behavior. Due to the proper combination and application of mechanical models, the global evaluation process is significantly simplified and avoids the lengthy iterative calculations performed in conventional numerical methods. Finally, the proposed calculational model is validated by comparisons between the predictions and experimental results of hybrid FRP-steel RC beams with common flexural failure modes available in the literature. [ABSTRACT FROM AUTHOR]

Constantly striving to develop a facile and scalable way to construct advanced electrodes is essential for the advancement of batteries and electrocatalysis. In this work, an artful K 2 FeO 4 oxidation cooperated with subsequent annealing process is proposed to produce 3D FeS embedded into N, S co–doped carbon nanotube/graphene (FeS/NSCNT/NSG) framework, which simultaneously achieves successful exfoliation of graphite, effective N, S co–doping and desirable integration of 3D framework by FeS and carbon matrix. The adopted procedure is simple, rapid and recyclable. Furthermore, the obtained FeS/NSCNT/NSG exhibits a unique 3D architecture, high doping level and favorable FeS dispersion status, thus displaying excellent performance towards lithium–ion batteries and oxygen evolution reaction. Undoubtedly, our research opens a new pathway for the development of advanced electrodes for energy storage and conversion devices. An artful K 2 FeO 4 oxidation assisted strategy can be used to produce 3D FeS/NSCNT/NSG framework, which realizes successful exfoliation of graphite, effective N, S co–doping and delicate assembly of multiple components, thus exhibiting good performance towards lithium–ion batteries and oxygen evolution reaction. [Display omitted] • An artful K 2 FeO 4 oxidation assisted strategy was proposed to produce 3D FeS/NSCNT/NSG. • The K 2 FeO 4 oxidation method is very simple, rapid and recyclable. • The adopted method achieves the goal of "one–stone–three–birds. • FeS/NSCNT/NSG shows unique 3D architecture and favorable FeS dispersion status. • FeS/NSCNT/NSG displays promising application towards LIBs and OER. [ABSTRACT FROM AUTHOR]

Arranging a hybrid combination of longitudinal fiber reinforced polymer (FRP) bars and longitudinal steel bars in the tensile zone of a concrete beam is able to sufficiently exploit the superior properties of both FRP and steel materials to achieve a satisfactory ductility level. As the foundation of analysis and design of hybrid FRP-steel reinforced concrete (RC) members, study of tensile behavior of concrete chords with FRP-steel reinforcement is essential and necessary. In this paper, the average crack spacing of hybrid (Glass Fiber Reinforced Polymer-GFRP and steel) RC chords is analytically estimated. Subsequently, the Tension Chord Model (TCM) is extended to predict the tensile behavior of hybrid GFRP-steel RC chords. Finally, the presented models are effectively validated by experimental results of concrete chords reinforced with GFRP bars and steel bars in different combinations available in the literature, and detailed discussions about analytical and experimental results are also performed. [ABSTRACT FROM AUTHOR]