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• Effect of three TiO 2 incorporation methods on photocatalytic (PC) efficiency of ECC is studied. • Effect of three TiO 2 incorporation methods on mechanical properties of ECC is studied. • Porous microstructure promotes the PC efficiency by increasing the exposure surface of ECC. • Alkaline environment of ECC consumes nitrate acid and promotes PC reactions. Titanium dioxide (TiO 2) nanoparticles have been incorporated in concrete to impart photocatalytic (PC) properties, such as the self-cleaning and air purification functionalities, which are dependent on PC reactions near the exterior surfaces of the concrete exposed to light. This study experimentally investigates the effect of three TiO 2 incorporation methods and surface patterns on the air-purifying functionality and mechanical properties of PC Engineered Cementitious Composites (PC-ECC). The air-purifying functionality was evaluated by measuring the nitrogen oxides (NO x) concentration change with the presence of PC-ECC plate specimens exposed to ultraviolet (UV) irradiation; uniaxial tensile and four-point bending tests were conducted to evaluate the tensile and flexural properties of the PC-ECC plates; scanning electron microscopy (SEM) was used to characterize the surface morphology of the plates; energy dispersive spectroscopy (EDS) was used to map the element distribution on the surface. Test results indicate that the amount of TiO 2 nanoparticles is reduced by 90% when TiO 2 is incorporated through a thin layer on the exterior surface of the ECC plate, while PC functionality and mechanical properties are retained. Incorporating TiO 2 through polyurethane coating reduces the NO x abatement efficiency by 70–80%, compared with directly mixing the TiO 2 nanoparticles in ECC. The reduced PC efficiency is attributed to the dense microstructure and low alkali content of the coating. This study advances the fundamental knowledge for designing functionally graded PC concrete with optimized PC efficiency and mechanical properties. [ABSTRACT FROM AUTHOR]

Highlights • 5% TiO 2 in ECC saturates air-purification ability while preserving tensile properties. • The optimized TiO 2 -doped ECC sustains a tensile strain capacity of 4.0%. • Alterations in tensile properties of ECC by TiO 2 are understood by micromechanics. • Both site effect and dilution effect are operative in ECC when TiO 2 is added. Abstract Engineered Cementitious Composites (ECC) provides a unique platform to develop high-performance and multifunctional construction materials with strain-hardening properties and exceptional crack control capability. ECC incorporating titanium dioxide (TiO 2) nanoparticles has intrinsically embodied photocatalytic properties, such as air-purifying functionality. However, there remains a lack of fundamental knowledge on how the presence of TiO 2 nanoparticles affects fiber/matrix interface and macro tensile properties of ECC. There is a need to establish a holistic understanding of the role of TiO 2 nanoparticles in ECC at multiple scales. To this end, this study experimentally investigates the effect of TiO 2 content (up to 15% of binder) on the fiber/matrix interface and on the tensile properties of ECC. A micromechanical model is used to link the multiscale material properties and interpret the test data of the TiO 2 -doped ECC. Results show that changes in the macroscopic tensile properties as a result of TiO 2 addition can be traced back to the matrix and fiber/matrix interface properties. The research findings provide insights into the underlying mechanisms of tensile property modifications by TiO 2 nanoparticles, as well as establishing a reference for the design of photocatalytic ECC for balanced functional and mechanical properties. [ABSTRACT FROM AUTHOR]

Despite the intuition that synchronization of different nodes in coupled oscillator networks results from information exchange between them, it has recently been shown that remote nodes could be partially synchronous even when they are separated by intermediately unsynchronized nodes. Here based on electro-optic system, we report on a more stronger form of such synchronization pattern that is termed as secure remote synchronization, in which two remotely separated nodes could have identically synchronized dynamical behaviors while the rest of the network are both statistically and information-theoretically incoherent relative to the two synchronized nodes. The generalized form of mirror symmetry in the network structure is identified to be a key mechanism allowing for secure remote synchronization. Moreover, this synchronization mode is robust against a wild range of system parameters and noise perturbing the intermediary dynamics. The lack of information about the synchronized dynamics in the rest of the network suggests that our results could potentially lead to network-based solutions for secure key distribution and secure communication. [ABSTRACT FROM AUTHOR]

• UV-B irradiation reduced oxidative stress and CI of cold-stored tomato fruit. • UV-B irradiation induced gene expression and activation of SOD and CAT. • SIUVR8 silence counteracted UV-B-induced gene expression of SOD and CAT. • UV-B induced cold tolerance by activating SOD and CAT dependently on SIUVR8. The impact of ultraviolet-B (UV-B) treatment on oxidative stress, cold damage, and antioxidant enzymes and the role of the UV-B photoreceptor SlUVR8 in tomatoes during cold storage were investigated. Mature-green tomato fruit were irradiated with 1, 10, or 100 μmol m−2 s-1 UV-B for 1, 3, or 6 h respectively before cold-storage. The chilling injury index (CI), H 2 O 2 , O 2 −, ion leakage, and malondialdehyde (MDA) content in tomatoes stored at 2 ℃ increased during storage, while irradiation with 10 μmol m−2 s-1 UV-B for 3 h before storage significantly reduced H 2 O 2 and O 2 −, membrane damage and chilling injury. Expression of CuZuSOD , FeSOD and CAT1 and the activities of their encoded enzymes superoxide dismutase (SOD) and catalase (CAT) were markedly raised in UV-B-pre-irradiated tomatoes and correlated significantly with the reductions in H 2 O 2 , O 2 −, ion leakage, MDA, and CI, which suggested that UV-B pre-irradiation might exert its effects by activating the antioxidant enzymes. Silencing SlUVR8 dramatically counteracted the UV-B-mediated effects on enzyme expression while the contents of H 2 O 2 , O 2 −, ion leakage, MDA, together with the CI in SlUVR8 -silenced tomatoes were significantly higher. The data showed that silencing of SlUVR8 not only suppressed UV-B-activated SOD and CAT expression, but also prevented UV-B-alleviated oxidative stress and chilling injury. The findings indicated that SlUVR8 was required for UV-B-induced cold tolerance in tomato fruit and demonstrated that UV-B irradiation before cold storage activated SOD and CAT in an SlUVR8-dependent manner. [ABSTRACT FROM AUTHOR]

• A lipid and protein co-oxidation model containing fish oil and WPI was established. • Resveratrol significantly suppressed lipid oxidation and protein carbonylation. • Formation of MDA-bound proteins in WPI was restrained by resveratrol. • Decrease in protein digestibility under oxidation was mitigated by resveratrol. • Phenol-protein interactions also contribute to physicochemical changes in WPI. In this study, the impact of resveratrol (RES) on co-oxidation of lipid and protein in a fish oil-fortified whey protein isolate (WPI) emulsion was investigated. Oil-in-water (O/W) emulsions containing 1% fish oil, 6 mg/mL of WPI and RES (0.08 ~ 2 mM) were oxidatively stressed using a Fenton system at 25 °C for 24 h. The incorporation of RES significantly suppressed lipid oxidation (TBARS) and protein carbonylation. Oxidation-induced decrease on protein sulfhydryl content and surface hydrophobicity were partially attenuated by RES, but protein tryptophan fluorescence was further decreased with the increased concentration of RES. Visualization of protein patterns and MDA-bound protein suggested that RES is capable of inhibiting protein modification induced by secondary products of lipid oxidation. Significant decrease in protein digestibility under oxidizing condition was also mitigated by RES. Our study contributes to the exploration of complicated interactions between oxidized lipids and proteins when phenolic compounds are present. [ABSTRACT FROM AUTHOR]

• Impacts of relative humidity (RH) on tensile properties of ECC is elucidated. • Its mechanism is revealed by the response of matrix and fiber/matrix interface to RH. • It advances the standardization of ECC preparation of property characterization. In recent years, broad interests in ductile Engineered Cementitious Composites (ECC) have been accompanied by increasing amount of laboratory investigations of this material. Both wet and air curing have been applied in the preparation of specimens. However, the effect of curing condition on mechanical properties of ECC has yet to be elucidated. This research attempts to fill this knowledge gap. Specifically, experiments were conducted to investigate property changes at different length scales under three curing relative humidity (RH) levels. Macroscopic properties including composite first crack strength, ultimate tensile strength and strain capacity, and crack pattern of ECC reinforced with PVA fibers were recorded. As well, matrix fracture toughness and fiber/matrix interface properties were measured. Correlation of macro-properties and micromechanical parameters was interpreted using a previously developed micromechanical model. The changes of tensile properties and crack pattern were found traceable to RH effects on the matrix and fiber/matrix interface properties. The findings of this study reveal the underlying mechanisms of property differences in specimens cured under different RH. The knowledge gained provides a better understanding of the effects of curing conditions on ECC specimens used in property characterization, and is particularly relevant to maintaining consistency in standardized testing of ECC. [ABSTRACT FROM AUTHOR]

• Basalt fiber-ECC with unique strain-hardening and multiple-cracking behavior has been developed. • BF-ECC demonstrates an average crack width below 10 μm and crack spacing less than 3 mm. • The tight and saturated cracks are attributed to the bridging behavior of basalt fiber in matrix. Fiber plays a key role in the mechanical properties of Engineered Cementitious Composites (ECC), a new generation of fiber-reinforced concrete with excellent ductility and exceptional crack control capability. However, ECC loses its high ductility when exposed to fire, as the synthetic fibers typically used in ECC melt resulting in a loss of crack-bridging ability in elevated temperatures. In this study, the feasibility of using basalt fiber, an inorganic fiber with high-temperature resistance, to develop ECC is investigated experimentally. The results show that basalt fiber reinforced ECC (BF-ECC) exhibits a very unique strain-hardening and multiple-cracking behavior when compared with typical ECCs. The tensile stress–strain curve of BF-ECC is relatively smooth, with average crack width below 10 μm and crack spacing less than 3 mm. The unique features of BF-ECC are interpreted based on the bridging behavior of basalt fibers. This work paves the way for further developing ECC with high-temperature resistance. [ABSTRACT FROM AUTHOR]

• SHCCs are developed using basalt fiber and calcium aluminate cement. • Tensile stress–strain relationship of SHCC at high temperature is studied. • Compressive stress–strain relationship of SHCC at high temperatures is studied. • Strain-rate effect and specific energy absorption of BF-SHCC are studied. • DIF and strain rate of BF-SHCC at elevated temperatures are calculated. In this study, a basalt fiber strain-hardening cementitious composite (BF-SHCC) with good high-temperature mechanical performance was developed, and its static and dynamic compressive properties at elevated temperatures were investigated. The BF-SHCC lost its strain-hardening behavior at 200 °C. At a constant strain rate, the dynamic compressive strength and specific energy absorption of the BF-SHCC showed an increasing trend over the temperature ranges of 20–200 and 400–600 °C. The tensile and compressive properties of the BF-SHCC depended on its microstructure. [ABSTRACT FROM AUTHOR]

• Through metabolites analysis, 1896 annotated metabolites were obtained. • Differences among compounds were found between mature and immature fruits. • The correlations were found between the antioxidant activities and VC content. Acerola cherry (Malpighia emarginata D.C.) is a tropical fruit of great economic and nutritional value due to its high content of vitamin C. However, there is little information available about which ripening stage of Acerola cherry can provide the best nutrients. In the current study, the chemical variation at two developmental stages (immature and mature) were investigated by metabolic profiling, and the biological properties of Acerola cherry and its antioxidant assays at four developmental stages were measured, respectively. Through comprehensive metabolites analysis via ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry system (UPLC-QTOF), 1896 annotated metabolite features were obtained, and 133 metabolites were finally identified according to the MS/MS fragments compared with these standards in in-house database. Statistically differences in the levels of amino acids, flavonoids, lipids, terpenoids and ascorbic acids were found between mature and immature fruits. Interestingly, most of differential accumulated amino acids, flavonoids, lipids, and terpenoids predominantly accumulated in the mature fruits and ascorbic acid predominantly accumulated in the immature fruits. On the other hand, their antioxidant activities were compared. The alcoholic extract of immature acerola fruit possessed better scavenging ability of DPPH and ABTS than the mature one. The well correlations were found between the antioxidant potential with its content of ascorbic acid (r = 0.9803 and 0.9897, respectively). In conclusion, Acerola cherry showed very different metabolite profile and antioxidant activities during the fruit ripening development. The maturity of Acerola cherry has to be considered when it is being used for health food products. [ABSTRACT FROM AUTHOR]

• TiO 2 in ECC is effective in NO x abatement. • Increasing fly ash content is found to enhance the NO x abatement rate and efficiency. • The improvement in NO x abatement rate and efficiency is related to microstructure modification. • A first-order reaction model can effectively capture the NO x abatement through PC reactions. Titanium dioxide (TiO 2) nanoparticles have been incorporated in cementitious composites to achieve photocatalytic (PC) functions such as self-cleaning and air purifying functions. This study experimentally investigates the effect of TiO 2 nanoparticles and fly ash on the nitrogen oxides (NO x) abatement rate and efficiency of Engineered Cementitious Composites (ECC) that has retained strain-hardening properties and tensile ductility. Emphasis is placed on understanding the fundamental mechanisms through research on the microstructures and chemical environment of the composite material. A first-order chemical reaction model is applied to analyze the PC reaction rate and residual NO x concentration. Test results indicate that the PC reaction rate and efficiency increase with the TiO 2 content from 0 to 5%, and the fly ash to cement ratio from 0 to 2.2. Using the low-calcium fly ash further increases the PC reaction rate and efficiency. The microstructure change originated from different fly ash contents and types are closely related to PC efficiency changes. This study advances the fundamental knowledge for engineering the cementitious composites to achieve the optimal PC functions. [ABSTRACT FROM AUTHOR]

Using Martian resource to construct a site on Mars is a superior choice to instead of transporting all the construction materials from Earth to the Mas with incredibly high cost. This study proposes a developed Martian concrete composed of sulfur and magnetite, heated by microwave to meet the energy-poor environment on Mars. A lattice Boltzmann model is developed to determine the optimal microwave power and heating time for Martian concrete casting. The compressive strength and microstructure of Martian concrete casted by microwave are measured by test. Finally, a 3D printed device is conceived to prepare Martian concrete and the four-layered specimen is casted to simulate the 3D print process. The results indicate that the compressive strength of Martian concrete casted by microwave can reach 1.78 kgf/mm2 (17.44 MPa) on earth, which is corresponding to 4.62 kgf/mm2 on Mars. Since the heating rate of magnetite under microwave is very high, if possible, the low microwave power and long heating time should be chosen to reduce the temperature gradient in matrix and reduce the possibility of sulfur matrix boiling. In addition, the strength of four-layered (simulated 3D printed) Martian concrete can reach 1.21 kgf/mm2 (11.86 MPa) on earth, which is corresponding to 3.15 kgf/mm2 on Mars. [Display omitted] [ABSTRACT FROM AUTHOR]

• High refractive index polyimides with as high as more than 1.8 of RI value were developed. • Solubility was greatly improved realizing the use of easy processing method. • PI showed high-low-high cycles of RI in film state under redox condition. Soluble high refractive index polyimides have extensive applications in optical devices due to their ease of processing and versatility. In this work, selenide-containing polyimides were designed and synthesized via amine-dianhydride polycondensation. Two selenide containing diamines, e.g. bis(3-trifluoromethyl-4-aminophenyl)selenide (BTFAPS) and bis(4-aminophenyl)selenide (BAPS) were reacted with 4,4′-(Hexafluoroisopropylidene)diphthalic anhydride (6FDA) for the preparation of selenide containing polyimides. Comparison with its oxygen and sulfur counterparts, the selenide-containing PIs have better solubility, higher refractive index, and can bring redox responsiveness. This is due to the trifluoromethyl base, which possesses a large free volume, and the selenium element, which has a higher molar refraction and redox activities than even sulfur. Various techniques, such as nuclear magnetic resonance, gel permeation chromatography, Fourier transformed infrared spectroscopy and wide angle X-ray diffraction were used for characterizing the polymers structure. Differential scanning calorimetry, thermogravimetric analysis, ultraviolet-visible spectroscopy, spectroscopic ellipsometry and X-ray photoelectron spectroscopy were used to characterize the properties of the polymers. [ABSTRACT FROM AUTHOR]

Elicitation represents one of the most efficient techniques for improving metabolite biosynthesis and biomass accumulation in plant cell cultures. Melatonin (MLT) has been extensively studied for its multiregulatory functions, but its elicitation roles in medicinal plants remain largely unknown. Herein, we investigated the effects of MLT on triterpenoid saponin biosynthesis and root growth in hairy root cultures of Psammosilene tunicoides , an endangered Chinese medicinal plant famous for its pain-relieving capabilities. Exogenous MLT significantly boosted saponin accumulation, promoted primary root thickness and elongation, and increased biomass production compared with the control in P. tunicoides hairy roots, particularly when 10 mg L− 1 MLT was applied for two days. Furthermore, the reactive oxygen species (ROS), nitric oxide (NO), and Ca2+ contents, as well as antioxidant enzyme activities, were initially triggered after MLT treatments. Additionally, MLT raised the diverse phytohormone profiles that were related to plant secondary metabolism (salicylic acid, jasmonic acid, abscisic acid) and growth (indoleacetic acid (IAA) conjugates, cytokinins, and strigolactone) but decreased free IAA levels in hairy roots. Analysis of comparative transcriptome data revealed that multiple differentially expressed genes (DEGs) might be the key regulators in MLT-elicited networks, especially genes that were associated with signal transduction (POD , NR, and CDPK), transcription factor regulation (WRKYs , NACs, and AR2/ERFs), terpenoid metabolism (HMGS , DXS , GPPS, and SE) and root growth (COBL7 and Egase). These findings demonstrated that MLT elicitors could simultaneously improve saponin biosynthesis and primary root growth in P. tunicoides hairy roots, mainly by enhancing the ROS-mediated signaling cascade and coregulating the associated phytohormonal and transcriptional pathways. • Melatonin enhanced saponin synthesis/ primary root growth in P. tunicoides hairy root. • Second messengers and antioxidant enzymatic activities were triggered by melatonin. • Melatonin altered the phynotype-related hormone profiles, including reduced IAA level. • RNA-seq revealed the transcriptional chains in melatonin-elicited processes. • Melatonin up-expressed DEGs in saponin synthesis (DXS , SE) / root growth (COBL , Egase). [ABSTRACT FROM AUTHOR]

Calcium sulfoaluminate (CSA) cements have lower carbon dioxide (CO 2) emissions during production compared with conventional ordinary Portland cement (OPC). However, the high cost of production is a significant limitation of the application of CSA cements. This paper aims to improve the use efficiency of CSA clinker by adding OPC and anhydrite. The low-carbon OPC-CSA clinker-anhydrite system is expected to contain less CSA clinker while showing excellent performance. A design methodology was developed to optimize the component of the OPC-CSA clinker-anhydrite blended system. The hydration mechanism of the ternary system was investigated using isothermal conduction calorimetry, X-ray diffraction (XRD), and thermogravimetric analysis (TGA), and thermodynamic modelling was used to predict the amount of hydration products. The results showed that ettringite is the main hydration products of the OPC-CSA clinker-anhydrite system, and the addition of OPC provides portlandite for the formation of ettringite. The ternary system is characterized by rapid development of strength and low CO 2 emissions. The compressive strength at 4 h and the CO 2 emissions are about 10 MPa and 500 kg/t, respectively. In addition, the ternary system, composed of 27.9 wt% CSA clinker, 32.5 wt% anhydrite, and 39.6 wt% OPC has the highest compressive strength at 28 d and the lowest CO 2 intensity. [ABSTRACT FROM AUTHOR]

Alternative low-carbon cements could contribute significantly to CO 2 reduction in the cement industry. However, the existing methods require the input of the actual production data, and thus cannot be used to calculate CO 2 emissions of alternative low-carbon cements that are not yet produced in cement plants. This study aims to develop a model to analyze the theoretical CO 2 emissions of alternative low-carbon cements. The novelty of this model is that it can be used to calculate the fuel consumed in the production of new low-carbon cements based on the theory of heat balance, and then predict their CO 2 emissions. The model is used to calculate CO 2 emissions of several low-carbon binders and ordinary Portland cement (OPC). The results show that the direct CO 2 emissions of OPC clinker calculated by this model approach the value derived from the cement plants and the Cement Sustainability and Initiative (CSI). Calcium sulfoaluminate (CSA) clinker has the direct CO 2 emissions of 0.540 kg/kg, 34% lower than OPC clinker, while its cost of raw materials is over four times that of OPC clinker. High-belite calcium sulfoaluminate (HB-CSA) clinker, with the direct CO 2 emissions comparable to CSA clinker, lowers its cost of raw materials by half as it requires less expensive bauxite. Moreover, CO 2 emissions from HB-CSA cement production can be further reduced by the use of high volume of supplementary cementitious materials (SCMs). The knowledge gained provides a valuable reference for the design of new low-carbon binders. [ABSTRACT FROM AUTHOR]

Innovations in the cement industry strive towards achieving an eco-friendly alternative to traditional cement. A low-carbon cement, calcium sulfoaluminate-activated supersulfated cement (CSA-SSC), has been recently developed. This cement consists of 80% granulated blastfurnace slag (GBFS), 15% anhydrite, and 5% high-belite calcium sulfoaluminate cement (HB-CSA) clinker. The hydration mechanism of CSA-SSC was experimentally investigated using isothermal calorimetry, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy, and was numerically studied using thermodynamic modeling. CSA-SSC shows a moderate compressive strength at the early stage, which is mainly attributed to the rapid formation of ettringite from the hydration of C 4 A 3 S ¯ with CaSO 4 in HB-CSA clinker. Meanwhile, the hydration of f-CaO in HB-CSA clinker supplies an alkaline environment for the dissolution of GBFS and the formation of more ettringite. In the late stage, apart from ettringite, the hydration of GBFS forms C–S–H, leading to the continuous increase in late strength. A statistical analysis reveals that the high volume of GBFS in CSA-SSC results in a very low direct CO 2 emission, which is only 8.7% of that of Portland cement. [Display omitted] • CSA-SSC is comprised of 80% GBFS, 15% anhydrite and 5% HB-CSA clinker. • The carbon dioxide emission of CSA-SSC is 72.0 kg/t, 8.7% of that of PC. • CSA-SSC shows relatively higher compressive strength than PC and other types of SSCs. • The hydration of CSA-SSC produces ettringite from beginning and C–S–H at later stage. • CSA-SSC has a high ratio of compressive strength to amount of non-evaporable water. [ABSTRACT FROM AUTHOR]

• PCE-type GA was synthesized by grafting acylamino groups and hydroxyl groups. • PCE-type GA led to shorter grinding duration with homogenized particle morphology. • Cement ground by PCE-type GA showed higher fluidity and mechanical strength. Modified polycarboxylate-type (PCE-type) grinding aid (GA) by grafting acylamino group and hydroxyl group into the backbone of PCE polymer was synthesized, and its possibility to be adopted as cement GA was estimated in this research. The grindability of PCE-type GA was measured in terms of grinding duration as well as particle size distribution, and the grindability of PCE-type GA was systematically compared with that of triethanolamine (TEA) and ordinary PCE-type superplasticizer. The cement hydration kinetics, the microstructure, and the physical–mechanical properties of ground cement samples in the function of PCE-based GA were analyzed. The results indicated that PCE-type GA was more effective in cement grinding process than TEA as well as PCE-type superplasticizer, exhibiting shortened grinding duration, optimized particle size distribution, and homogenized particle morphology. And cement ground by PCE-type GA was characterized with lower water demand, higher fluidity property, and increased mechanical strength, ascribed to the dispersion capability of PCE polymer as well as the unified cement particle size distribution. The application of PCE-type GA could slightly prolong the induction period of the ground cement, but gently enhance the hydration degree. Lower porosity and denser microstructure with higher density of cement hydration products uniformly distributing in the hardened matrix could be achieved with PCE-type GA adopted in the ground cement. [ABSTRACT FROM AUTHOR]