Search

• 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]

• Out of the four landscape patterns, the most effective cooling scenario is square D, with high canopy closure and concrete paving. • Square D also shows a less fluctuated temperature and humidity, peaking at a later time in comparison with others. • Between the two simulated scenarios of square B with lawn grass and asphalt as the ground cover, lawn grass scenario shows a lower surface temperature. • The simulation also suggests a higher surface temperature of the surrounding buildings when using asphalt as the ground material than when using lawn grass. This research uses empirical data and supplementary computer simulation result to study the summertime cooling effect of different landscape patterns in urban areas in China. It employs field monitoring to collect hourly air temperatures and relative humidity at pedestrian level over five consecutive days in July 2016, and calculates the discomfort index for each scenario in studied urban squares. It also builds simulation models using Citysim and Meteonorm software to further explore the cooling effects of different landscape patterns within the same square. The results from field research show that the difference in cooling and humidification amongst the four landscape patterns is significant, as is the thermal comfort or discomfort caused by such effect. The research finds that the urban square equipped with only hard paving and no canopy coverage could cause extreme discomfort and heatstroke during summertime in the studied climate, whereas the urban square with lawn grass, high canopy closure and thick canopy can reduce discomfort. The simulation analysis further confirm that lawn grass can noticeably reduce the ground surface temperature and the surface temperature of the surrounding buildings than if using asphalt as the ground cover. The findings from this research provide design guidance for the landscape configuration of urban squares in similar climates. [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]