In order to investigate the effect of phase change materials on the frost resistance of concrete in cold regions, hollow steel balls were used in this paper for the macroscopic encapsulation of the phase change material to replace some of the coarse aggregates in the preparation of phase change concrete. On the premise of ensuring reasonable mechanical properties, concrete mixed with different contents and different surface treatments of grouting steel balls were tested for the compressive strength and splitting tensile strength to determine the optimum content of phase change steel balls and investigate the frost resistance of phase change concrete. At the same time, industrial CT was used to explore the internal pore evolution pattern of concrete during the freeze–thaw period. The test results show that the optimum content of steel balls is 75%; during the freeze–thaw process, the mass loss, relative dynamic elastic modulus loss, and strength loss of phase change concrete are all lower than those of ordinary concrete, and the increase in porosity of phase change concrete is also significantly lower than that of ordinary concrete; the addition of phase change materials can optimise the distribution of the internal pore in concrete, improve its internal pore structure, and enhance its frost resistance. Phase change materials can make use of latent heat to store energy, and these materials can store or emit large amounts of heat through changes in their phase state to regulate the room temperature ,2. AccorThe encapsulation of phase change materials is generally carried out by physical mixing methods, including macro-encapsulation and micro/nano-encapsulation, but the latter is too expensive and may have a negative impact on the mechanical properties of the corresponding structure, as well as building materials. In contrast, the macro-encapsulation of phase change materials in carriers such as light aggregates, spheres, and slabs, which are larger in volume, compared to micro/nano-encapsulated carriers, does not have much impact on the structural function of the building and has the advantages of simple production methods, low costs, the direct replacement of concrete aggregates, etc. As a result, this technology has received widespread interest from various studies ,9,10,11.In recent years, phase change materials have been used in buildings for energy efficiency, both for comfort and for reducing energy losses ,13. HadjIn terms of temperature control in mass concrete, the incorporation of phase change materials can help to transfer the accumulated heat of hydration within mass concrete , alleviaAs icing on road surfaces has been difficult to tackle effectively in winter, especially in cold regions, many scientists have conducted in-depth research in recent years on using phase change materials to speed up ice and snow melting on pavements. Nayak et al.  used finThis research aims at studying the effect of PCM on the freeze–thaw resistance of concrete by using macroscopic encapsulation of PCM. Hollow steel balls containing phase change material were used to replace some of the coarse aggregates to modify concrete with guaranteed mechanical properties and the maximum amount of PCM added. On the premise of ensuring reasonable mechanical properties, concrete mixed with different contents and different surface treatments of grouting steel balls were tested for mechanical properties to determine the optimum admixture of phase change steel balls. Furthermore, rapid freeze–thaw tests were conducted on phase change concrete, and its freeze-resistance performance was studied by comparing and analysing the loss of mass, relative dynamic elastic modulus, and mechanical properties during freeze–thaw. In addition, industrial CT was used for nondestructive testing of concrete, and an in-depth analysis of the effect of phase change concrete on internal pore evolution and pore distribution during freeze–thaw was carried out.PO42.5 ordinary silicate cement was used, its chemical composition and related basic properties are shown in 3, and the mass of phase change material was 63% of the steel-ball-containing PCM.The main component of the phase change material used in this test was tetradecane, which accounted for over 95%. The latent heat of phase change for the organic phase change material with a phase change temperature of 2 °C was found to be about 191.59 J/g. The hollow steel balls made of stainless steel 304 with an inner diameter of 23 mm and an outer diameter of 25 mm were used to encapsulate the phase change material. A 1 mm diameter hole was made in the upper part of the balls, and the balls were filled with phase change material through a syringe and then sealed by welding. Compared to other carrier materials such as ceramic pellets, the steel ball has the characteristics of a strong ability to contain phase change material and a good sealing effect; therefore, it is not easy to cause phase change material leakage. The steel ball was fully filled with PCM, the density of the phase change steel ball was 1743 kg/m3 for the grouting steel ball.For the preparation of grouting steel balls, the hollow steel balls with the same inner diameter and outer diameter were used. A hole with a diameter of 6 mm was made in the upper part of steel balls, and then the balls were filled with cement slurry. After the cement slurry had dried slightly, the total mass of the hollow steel ball and the cement slurry was weighed to obtain a density of 2439 kg/mIn this paper, 75% volume of large coarse aggregate (20~30 mm) was replaced by an equal volume of phase change steel balls to prepare phase change concrete, and a control group was set up as shown in In this test, in order to investigate the effect of grouting steel balls with different surfaces on mechanical properties of concrete, the surface of a portion of the balls was treated with a metal repairing agent, thus classifying the grouting steel balls into two types: smooth surface and rough surface.Grouting steel balls were used to replace 25%, 50%, 75%, and 100% volume of large coarse aggregate (20~30 mm) by equal volume, corresponding to the mix ratio design of concrete, as shown in All concrete specimens were demoulded at 24 h after casting and cured in standard curing boxes for 28 days.Compressive and splitting tensile tests were carried out on concrete with four different contents of grouting steel ball in the paper, and the test results were analysed to determine the optimum content for subsequent frost resistance tests on concrete admixed with phase change steel balls.The specimen size chosen for compressive and splitting tensile tests was 100 mm × 100 mm × 100mm, with reference to GB/T50081-2019. MTS universal testing machine  was used, shown in The concrete with the appropriate amount of phase change steel balls was prepared by referring to the results of the mechanical properties test. A rapid freeze–thaw test was carried out according to the test method specified in GBT50082; the equipment produced by Tianjin Gangyuan Test Instrument Co. Ltd.  used is shown in The specimens with dimensions of 100 mm × 100 mm × 100 mm were immersed in water for 4 days and then removed for the freeze–thaw cycle test. During the test, the temperature in the centre of specimens was controlled from a minimum of (−18 ± 2) °C to a maximum of (5 ± 2) °C. Before the freeze–thaw test and after every 50 freeze–thaw cycles, the mass and the dynamic modulus of elasticity, as well as the strength, were measured. The mass loss, the relative dynamic modulus of elasticity, and the strength loss were calculated from the average of three specimens. The DT-20 dynamic elastic modulus tester produced by Tianjin Gangyuan Test Instrument Co. Ltd.  was used, as shown in Industrial CT  produced by Sanying Precision Instruments Co., Ltd.  was employed to scan concrete specimens, and the CT data were processed using Avizo software to investigate the changes in the internal pore structure of phase change concrete and ordinary concrete under different freeze–thaw cycles. For both ordinary concrete and phase change concrete, only one specimen from each was scanned by CT with 0, 50, 100, 150, and 200 freeze–thaw cycles. In order to decrease the error caused by the boundary, the 100 mm × 100 mm × 100 mm specimen was cut into 80 mm × 80 mm× 80 mm in the postprocessing and pore structure analysis. After the samples were scanned by CT, Voxel Studio Recon software was used for reconstruction. The reconstruction resolution was 1100 × 1100 × 1100 PPI. Before the industrial CT scanning, the instrument self-examination and parameter setting work were carried out. After setting the voltage as 385 kV and current as 1.3 mA, the DR Film was taken for correction. The correction scanning was performed before every CT scanning, and parameters were set as the same for every scanning.The variation in compressive strength of concrete mixed with different contents and different surfaces of grouting steel balls is shown in It can be concluded from The effects of grouting steel balls with different dosing and surface treatments on splitting tensile strength of concrete are shown in According to Based on the above compressive strength and splitting tensile strength results, the optimum content of grouting steel balls is initially determined to be 75%, and the rough surface of the steel ball is more effective in modifying the concrete; the conclusions were applied to the subsequent freeze–thaw test.Based on the comparison of the mass loss rate and relative dynamic elastic modulus of ordinary concrete and phase change concrete during freeze–thaw, presented in The changes in compressive strength of concrete during freeze–thaw are shown in 3 accounts for the most, while that of less than 0.01 mm3 accounts for the least, and it is similar in the other three ranges.It can be seen from 3 in ordinary concrete decreases, and the proportion of pores within 1~10 mm3 increases continuously; the proportion of pores with the volume of 0.1~1 mm3 fluctuates; the proportion of pores with a volume greater than 10 mm3 gradually decreases before 150 freeze–thaw cycles and rebounds slightly at 200 cycles, with the pattern of change being the opposite of that of less than 0.01 mm3 pores. In the same case, the proportion of pores with the volume of 0.1~1 mm3 in phase change concrete tends to increase and then decrease, and fluctuations occur in all four other ranges.As freeze–thaw cycles increase, the proportion of pores within 0.01~0.1 mmFrom In this paper, the mechanical properties of concrete mixed with grouting steel balls were studied. The optimum content of steel balls was determined under the premise of ensuring the reasonable mechanical properties of concrete. Additionally, phase change materials were prepared into phase change coarse aggregate by being packed into hollow steel balls and then encapsulated macroscopically, so as to prepare phase change concrete according to the optimal dosage of steel ball in the frost resistance effect research. The main conclusions are as follows:(1)The incorporation of grouting steel balls can reduce compressive strength and increase the splitting tensile strength of concrete to varying degrees, and the balls with the rough surface have a better effect on the modification of concrete; combining the results of compressive strength and splitting tensile strength, the optimum dosing of grouting steel balls can be initially determined to be 75%.(2)During the freeze–thaw process, all the freeze-resistance indexes of phase change concrete are better than those of ordinary concrete. In the early freeze–thaw period (50 cycles), the difference in compressive strength loss between ordinary concrete and phase change concrete is not significant, while the improvement in splitting tensile strength of phase change concrete is more obvious at this time. In the middle freeze–thaw period (100–150 freeze–thaw cycles), the difference between them increases greatly and the advantage of phase change materials in improving the reduction of compressive strength is significant. In the late freeze–thaw period (200 freeze–thaw cycles), the difference in strength loss between the two types of concrete is not obvious.(3)Throughout the whole freeze–thaw process, the change in porosity of phase change concrete is significantly lower than that of ordinary concrete, and its internal deterioration is lesser. The addition of phase change materials optimises the pore structure distribution in concrete and improves the internal pore structure.


Several studies demonstrate that endoplasmic reticulum (ER) stress-mediated epithelial-mesenchymal transition (EMT) is involved in the process of bleomycin (BLM)-induced pulmonary fibrosis. Tauroursodeoxycholic acid (TUDCA), a bile acid with chaperone properties, is an inhibitor of ER stress. This study aimed to investigate the preventive effects of TUDCA on BLM-induced EMT and lung fibrosis.The model of lung fibrosis was established by intratracheal injection with a single dose of BLM (3.0 mg/kg). In TUDCA + BLM group, mice were intraperitoneally injected with TUDCA (250 mg/kg) daily.BLM-induced alveolar septal destruction and inflammatory cell infiltration were alleviated by TUDCA. BLM-induced interstitial collagen deposition, as determined by Sirius Red staining, was attenuated by TUDCA. BLM-induced elevation of pulmonary α-smooth muscle actin (α-SMA) and reduction of pulmonary E-cadherin were attenuated by TUDCA. BLM-induced pulmonary Smad2/3 phosphorylation was suppressed by TUDCA. BLM-induced elevation of Ki67 and PCNA was inhibited by TUDCA in mice lungs. In addition, BLM-induced elevation of HO-1 (heme oxygenase-1) and 3-NT (3-nitrotyrosine) was alleviated by TUDCA. Finally, BLM-induced upregulation of pulmonary GRP78 and CHOP was attenuated by TUDCA.These results provide evidence that TUDCA pretreatment inhibits Smad2/3-medited EMT and subsequent lung fibrosis partially through suppressing BLM-induced ER stress and oxidative stress.The online version contains supplementary material available at 10.1186/s12890-021-01514-6. Idiopathic pulmonary fibrosis (IPF) is characterized by excessive deposition of collagen, leading to death due to the lack of effective therapies , 2. BleoThere is increasing evidence that alveolar epithelial damage and lung fibrosis are associated with oxidative stress . ClinicaThe objective of this study is to investigate whether TUDCA has a therapeutic effect on BLM-induced EMT and subsequent lung fibrosis in a mouse model. Our results provide experimental evidence that TUDCA attenuates pulmonary EMT and subsequent lung fibrosis partially through suppressing BLM-induced oxidative stress and ER stress.BLM was purchased from HiSUN PFIZER Pharmaceuticals Co., Ltd; Zhejiang, China. TUDCA was prepared from EMD Millipore Corporation; Billerica, MA. Adult male C57BL/6 J  mice were provided by Beijing Vital River Laboratory Animal Technology Co., Ltd  and housed under a natural day/night cycle room with comfortable environment . Mice were supplied with enough food and water. Based on the previous studies of our laboratory and power calculation analysis, 80 mice were used in this study , 12. EigThe left lungs of the mice were collected and fixed with 4% paraformaldehyde solution. Lung tissue sections were stained with hematoxylin eosin (H&E) and observed under a light microscope by a blinded and experienced investigator. Morphological changes were scored absent (0), mild (1), moderate (2) or severe injury (3) based on the presence of exudates, hyperemia/congestion, neutrophilic infiltrates, intraalveolar hemorrhage/debris, and cellular hyperplasia. HE staining and pathological scores were conducted based on the existing literature . Mice inThe protein extraction and quantitative analysis were carried out based on the existing literature . Briefly2O2. Antigen retrieval was performed in the boiled citrate buffer for 4 min at an interval of 5 min, total 3 times. After inactivation of endogenous peroxidase and serum blocking, primary antibodies were incubated at 4℃ overnight. Then, goat anti-rabbit and goat anti-mouse IgG (1: 1000) were incubated 2 h at 37℃. Eventually, aspirate the primary antibody with a pipette, color reaction was detected with biotin-streptavidin peroxidase system [Pulmonary α-SMA, p-Smad3, 3-NT and Ki67 were detected using immunohistochemistry (IHC). Briefly, lung tissues were fixed in paraformaldehyde, dehydrated and embedded. Endogenous peroxidases were blocked in 3% He system . Moreovee system , 12. TenTgf-β , 18S . Gene expression was normalized to 18S.Total RNA extraction was referred to existing literature  and cDNAP < 0.05 was regarded as statistically significant.Statistical analyses were performed using SPSS software (version 23.0). Figures were produced using GraphPad Prism 7.0. The normality of distribution was analyzed using Kolmogorov–Smirnov test. Continuous variables were expressed as means ± S.E.M. or medians with interquartile ranges. Differences among different groups in normally distributed data were analyzed by ANOVA and Tukey's test. Data non-normally distributed were analyzed by nonparametric test . There was no death in Control and TUDCA groups. Bleomycin exposure induced death on the 4–7th and 14–17th days after the administration. Eight mice were died in the process of BLM-induced pulmonary fibrosis. There was no difference of healthy condition between Control and TUDCA groups. BLM exposure induced a dim hair, decreased appetite, activity and body weight. The healthy condition was better in Control and TUDCA groups than these in BLM and BLM + TUDCA groups. The average weight in four groups was as follows: Control: 25.0 g, TUDCA: 24.3 g, BLM: 19.5 g, BLM + TUDCA: 21.1 g. To investigate whether TUDCA alleviate BLM-induced pathological damage and collagen deposition of pulmonary fibrosis. H&E staining and Sirius Red staining was performed on lung tissue sections. According to H&E staining, the main histological damages in BLM-treated mice was alveolar septal destruction. Interestingly, pretreatment with TUDCA attenuated BLM-induced alveolar septal destruction in mice lungs  takes part in the process of BLM-evoked lung fibrosis , 25. HO-GRP78, an ER chaperone and a marker of ER stress, was elevated in lungs of BLM-treated mice. After pretreatment with TUDCA, the expression of GRP78 was decreased Fig. a, b. In In this study, we evaluated whether TUDCA pretreatment had a prophylactic effect on BLM-induced lung fibrosis in mice. Our results suggested that TUDCA alleviated BLM-induced pulmonary EMT and subsequent lung fibrosis. The specific findings include: (1) TUDCA pretreatment inhibits BLM-induced pulmonary TGF-β/Smad2/3 signaling activation; (2) TUDCA pretreatment prevents the elevation of α-SMA and reversed the reduction of E-cadherin during BLM-induced lung fibrosis; (3) TUDCA alleviates BLM-evoked collagen deposition in the mice lungs.Several studies suggest that pulmonary ER stress plays an important role in BLM-induced lung fibrosis , 12. TUDSmad2/3-mediated EMT of alveolar epithelial cells is involved in the pathogenesis of BLM-induced lung fibrosis , 23. In Though, the pathogenesis of IPF remains unclear. Nowadays, it is thought that IPF always results from an abnormal wound healing response to epithelial injury in genetically susceptible individuals . MoreoveIncreasing data have demonstrated that excess ROS taken part in the process of BLM-evoked lung fibrosis , 25. N-aIn this study, we have focused on protection effect of TUDCA pretreatment against TGF-β/Smad2/3-mediated EMT in the process of BLM-induced lung fibrosis. Nevertheless, there are a few limitations in this study. Firstly, the current study only investigated the preventive effect on BLM-induced pulmonary EMT and subsequent lung fibrosis by using a single dose of TUDCA. This is a prophylactic experiment. However, the treatment effect of TUDCA on BLM-induced lung fibrosis is not unclear. Secondly, this study did not explore the exact mechanism which TUDCA inhibited TGF-β/Smad2/3-mediated EMT in BLM-evoked lung fibrosis. Thirdly, only BLM-induced pulmonary fibrosis model was used in the current study. Because it has been found to have the possibility of self-recovery in a mouse model and species difference, multiple administrations and new suitable fibrosis models are needed in the future work. Thus, further research is necessary to investigate the effects of different TUDCA doses on BLM-evoked EMT and lung fibrosis. Fourthly, only part markers of EMT were measured in mice lungs. In order to evaluate the effect of TUDCA on BLM-evoked EMT, more in vitro experiments should be performed. Different pulmonary epithelial cells were selected and used. The change of morphology in pulmonary epithelial cells was observed. Additionally, wound healing, migration and invasion should be conducted in pulmonary epithelial cells. Besides, the levels of mRNAs and protein of markers in EMT, included E-cadherin, ZO-1, N-cadherin, Vimentin, α-SMA and Fibronectin, should be measured using RT-PCR and western blotting. Moreover, E-cadherin and α-SMA were also detected through immunohistochemistry. Not only that, EMT related nuclear transcription factors, such as Snail, ZEB and Twist, would be evaluated using western blotting and immunofluorescence.In summary, the aim of this study is to explore the effects of TUDCA on BLM-induced lung fibrosis in a mouse model. Our results showed that TUDCA suppressed pulmonary TGF-β/Smad2/3-mediated EMT in the process of BLM-induced lung fibrosis. We found that TUDCA alleviated pulmonary cell proliferation and collagen deposition during BLM-induced lung fibrosis. The present study provides experimental evidence that TUDCA prevents pulmonary EMT and subsequent lung fibrosis partially through suppressing BLM-induced oxidative stress and ER stress. Therefore, TUDCA may be used as a potential prophylactic drug for lung fibrosis.Additional file 1. The experimental protocol.Additional file 2. Antibodies information.


Current methods of experimentally degrading the specialized extracellular matrix (ECM), perineuronal nets (PNNs) have several limitations. Genetic knockout of ECM components typically has only partial effects on PNNs, and knockout of the major ECM component aggrecan is lethal in mice. Direct injection of the chondroitinase ABC (ChABC) enzyme into the mammalian brain is effective at degrading PNNs in vivo but this method typically lacks consistent, localized spatial targeting of PNN degradation. PNNs also regenerate within weeks after a ChABC injection, thus limiting the ability to perform long‐term studies. Previous work has demonstrated that viral delivery of ChABC in mammalian neurons can successfully degrade PNNs for much longer periods, but the effects are similarly diffuse beyond the injection site. In an effort to gain cell‐specific targeting of ChABC, we designed an adeno‐associated virus encoding ChABC under the control of the Cre‐LoxP system. We show that this virus is effective at targeting the synthesis of ChABC to Cre‐expressing mouse neurons in vivo. Although ChABC expression is localized to the Cre‐expressing neurons, we also note that ChABC is apparently trafficked and secreted at projection sites, as was previously reported for the non‐Cre dependent construct. Overall, this method allows for cell‐specific targeting of ChABC and long‐term degradation of PNNs, which will ultimately serve as an effective tool to study the function of cell‐autonomous regulation of PNNs in vivo. This novel approach may also aid in determining whether specific, long‐term PNN loss is an appropriate strategy for treatment of neurodevelopmental disorders associated with PNN pathology. Cre‐Dependent AAV‐ChABC Construct: To express chondroitinaseABC (ChABC) in a Cre‐recombinase dependent way, a shuttle plasmid containing a double floxed mCherry under the control of human synapsin promoter was used for the viral vector backbone, pAAV‐hSyn‐DIO‐mCherry. We tested this virus in mice expressing a tamoxifen‐regulated Cre recombinase in hippocampal area CA2.fx1 AAVadeno‐associated virusCA2Cornu Ammonis 2ChABCchondroitinase ABCIPintraperitonealPNNsperineuronal netsWFAWisteria floribunda agglutinin1The function of the specialized extracellular matrix (ECM), perineuronal nets (PNNs), has been effectively studied by degrading PNNs in vivo and in vitro using the exogenous enzyme chondroitinase ABC (ChABC). ChABC is a bacterial enzyme that catalyzes the degradation of the N‐glycosaminoglycan chains of chondroitin sulfate proteoglycans (CSPGs). ChABC has been found to improve functional recovery from spinal cord injury by targeting the upregulation of CSPGs and promoting structural plasticity at the site of injury  Animal Care and Use Committee and were in accordance with the United States National Institutes of Health guidelines for care and use of animals.Male mice, approximately 12 weeks of age, were group‐housed under a 12:12 light/dark cycle with access to food and water 2.2CC. In this AAV virus, the ChABC‐P2A‐mCherry cassette is flanked by both a loxP and a lox2722 site, such that when the cassette is inverted, two loxP sites will be flipped into a head to tail configuration and the intervening sequence between the head to tail loxP sites is deleted leaving only one loxP site behind. This loxP site is paired with the variant lox2722 site at the other end of the cassette, and the Cre enzyme does not invert or recombine the two distinct lox sites, thereby locking the cassette in one orientation that allows expression by the hSyn promoter. We also encoded a cleavable fluorescent reporter protein, mCherry, in the gene cassette via a P2A site such that mCherry will be expressed in cells that synthesize the ChABC enzyme, but not bound to the ChABC protein .In an effort to degrade PNNs with cell‐specificity, we designed a Cre‐dependent AAV that encodes the PNN‐degrading enzyme ChABC with a cleavable mCherry fluorescent protein linked to ChABC. The Cre‐loxP system can be used to specifically express a double‐floxed gene cassette in all cells that contain the Cre enzyme. The double‐floxed inverse orientation (DIO) arrangement takes advantage of the principle that the Cre enzyme is able to invert any DNA sequence that is flanked by two identical loxP sites in a head to head orientation, while the Cre enzyme deletes any DNA between head to tail loxP sites , KOZAK sequence to initiate translation  and P2A sequences to cleave ChABC from mCherry , used for cloning into pAAV‐hSyn‐DIO‐mCherry. The chondroitinase (ChABC) sequence is unformatted.For the ChABC gene insert, we used the synthetic chondroitinase gene sequence “Y133”’ that was published in lentiviral‐ChABC studies . The capsid‐encoding plasmid was Rep2/Cap5; pDP5rs . The ChABC cDNA and P2A sequence were subcloned into the AAV shuttle vector as an Xba I restriction fragment and verified for correct orientation by PCR Figure b. DNA se2.5Amigo2‐iCreERT2+) mice ‐Tg(Amigo2‐icre/ERT2)1Ehs (Wisteria floribunda agglutinin (WFA).After the virus infusion surgery, mice recovered from surgery for 2 weeks. Mice were then administered tamoxifen for 1 day  to permit Cre activity and induce recombination of the unpacked viral genome. A total of four mice were used for qualitative analysis of ChABC‐AAV expression and PNN degradation. Mice were arbitrarily assigned to two groups (2 per group) that would receive either tamoxifen or vehicle control (corn oil). The number of animals used and the tamoxifen dosing were based on the results of a pilot experiment, in which we found that 3 or 7 days of tamoxifen treatment resulted in a dose‐dependent loss of PNNs. Seven days of tamoxifen treatment is our typical protocol for maximal Cre activation  to label PNNs, rabbit anti‐PCP4  or mouse anti‐regulator of G‐protein signaling 14 (RGS‐14)  to label CA2 pyramidal cells, or guinea pig anti‐ZNT3 antibody  to label axons from the dentate gyrus (mossy fibers). Sections were washed three times in PBS and incubated in combinations of the following secondary antibodies at 1:500 for 40 min at room temperature: streptavidin Alexa‐488 (Invitrogen #S11226), goat anti‐rabbit A633 (Invitrogen #A21071), goat anti‐mouse A488 (Invitrogen # A11008), or goat anti‐guinea pig A633 (Invitrogen #A21105). Sections were mounted with Vectashield antifade mounting medium with DAPI (Vector Laboratories #H‐1500). Images were acquired on a Zeiss laser scanning confocal (LSM510 NLO) or a Zeiss light microscope using controlled camera settings. Images from the different wavelengths were pseudo‐colored for figure clarity.3Amigo2‐iCreERT2+ mice, to selectively target CA2 neurons . We infused the contralateral hemisphere with a vehicle  as control. We also added a no‐tamoxifen control Amigo2‐iCreERT2+ mouse that received AAV‐ChABC and saline infusions but no tamoxifen treatment. We found that the mCherry fluorescent reporter that is encoded in the AAV construct was expressed unilaterally in the AAV‐ChABC‐infused hemisphere and selectively in CA2 neurons, as defined by the CA2 marker PCP4 . Overall, this approach is advantageous in (a) targeting ChABC synthesis to a specific cell‐type and (b) addressing limitations of PNN regeneration such that ChABC synthesis and PNN degradation is sustained over time after Cre recombination. Note that the small number of animals in each case (two in each group) precluded quantitative analysis. Nevertheless, these data, combined with our pilot studies using higher tamoxifen doses and robustness of the evident effect, showed that qualitatively, PNNs were lost and staining for mossy fibers was increased in the stratum pyramidale. Lowering the dose of tamoxifen even further, or lowering the viral dose, in the case of studies using non‐inducible Cre, could further restrict the effects or spread of the ChABC, but effects would depend on the specific cell types studied. Future studies will be required to determine the effects of this construct on the integrity of specific PNN components and how they may be altered over time.By using a Cre‐dependent construct, we are now able to target the synthesis of ChABC with cell‐type specificity and, in our case, in an inducible manner, degrade PNNs in the targeted region. We successfully expressed ChABC selectively in hippocampal CA2 neurons using our conditional CA2 Cre‐expressing mouse line. The results of our study did, however, reveal limitations in the viral delivery of ChABC. First, degradation of PNNs surrounding the non‐pyramidal neurons in the neighboring CA1 and CA3 regions was observed, suggesting that ChABC‐expressing neurons will still traffic and secrete the enzyme to their terminals. This is very similar to what was previously reported for the non‐Cre dependent ChABC virus, in which viral delivery of ChABC produced widespread effects in both ipsilateral and contralateral hippocampus, in addition to similar outcomes in other targeted brain regions (Alves et al., In conclusion, this novel method is effective at targeting neurons in vivo with cell‐type selectively and overcomes limitations related to PNN regeneration over time. Moreover, the observed mossy fiber sprouting is also indicative of functional outcomes, a finding that is consistent with a previous study that observed regeneration of lesioned corticospinal axons after treatment with the non Cre‐dependent ChABC virus (Zhao et al., The authors declare no conflicts of interest.KEC, BG, and GMA performed experiments. KEC analyzed the data. KEC, BG, GMA, and SMD designed and coordinated the investigations. KEC wrote the manuscript with input from BG, GMA, and SMD.https://publons.com/publon/10.1111/ejn.15050.The peer review history for this article is available at


A total of 17,931 ligands were screened from the ZINC15 database. LibDock is applied for structure-based screening followed by absorption, distribution, metabolic, and excretion, and toxicity prediction. Molecular docking was conducted to confirm the binding affinity mechanism between the ligand and c-MET. Molecular dynamics simulations were used to assess the stability of ligand-c-MET complexes.Two new natural compounds ZINC000005879645 and ZINC000002528509 were found to bind to c-MET in the ZINC database, showing higher binding affinity. In addition, they were predicted to have lower rodent carcinogenicity, Ames mutagenicity, developmental toxicity potential, and high tolerance to cytochrome P4502D6. Molecular dynamics simulation shows that ZINC000005879645 and ZINC000002528509 have more favorable potential energies with c-MET, which could exist stably in the natural environment.This study suggests that ZINC000005879645 and ZINC000002528509 are ideal latent inhibitors of c-MET targeting. As drug candidates, these 2 compounds have low cytotoxicity and hepatotoxicity as well as important implications for the design and improvement of c-MET target drugs. Currently, the standard treatment for patients with GBM is surgical resection and radiotherapy, accompanied by temozolomide or Carmustine chips. However, the heterogeneity and instability of GBM in its growth and differentiation make it prone to multiple resistance to radiation and chemical treatments. Therefore, the prognosis of most patients with GBM is poor and the therapeutic effect is not ideal.Glioblastoma (GBM) is the most common primary malignant brain tumor in the clinical central nervous system, which has a high degree of proliferation and invasion, accounting for 12% to 15% of all brain tumors. c-MET is associated with a variety of oncogene products and regulatory proteins and has a strong role in promoting cell proliferation. It is involved in various processes in vivo, such as cell signal transduction and cytoskeletal reconstruction, and is an important factor in regulating the process of cell proliferation, differentiation, and repair. The c-MET gene encodes the receptor of the stem cell growth factor (HGF) ligand. In the classic HGF/c-MET signaling pathway, the binding of HGF to c-MET leads to the dimerization of c-MET and the self-phosphorylation of hydroxy-terminal tyrosine, thereby activating the downstream mitogen-activated protein kinase (MAPK) signaling pathway, phosphoinoside-3 kinase signaling pathway, and RAS-related C3 botox substrate 1-cell division cyclin 42 signaling pathway. c-MET is phosphorylated without HGF by binding to epidermal growth factor receptor, cell adhesion molecules, and abnormal prothrombin. Regardless of the pathway in which c-MET is activated, dimerization, phosphorylation, and kinase activation are necessary for malignant lesions in neurogenic tumors. c-MET was highly expressed in GBM cells, blood vessels, and peri-necrotic areas. At the subcellular level, c-MET was presented in the cytoplasm and in the cell membrane. c-MET has also been connected to the stem cell phenotype in glioma by regulating sphere formation, cell proliferation, and differentiation.,8c-MET is a member of the receptor tyrosine kinases superfamily, cell surface receptors that are heterodimers made up of a-chains and transmembrane d-chains (1145 k da) connected by disulfide bonds normally expressed in epithelial cells of various organs.,10 Tivantinib inhibits c-MET by blocking the signaling cascade, promoting apoptosis, and inhibiting cell growth. However, there are some limitations. In some cases, Tivantinib failed 2 phase III studies involving second-line treatment of Met-high, advanced, hepatocellular carcinoma, despite its success during phase II studies. Consequently, the aim of this study was to screen natural compounds from natural drugs that are more effective than Tivantinib in treating cancer.In summary, c-MET kinase promotes GBM cell proliferation, migration, invasion, and angiogenesis. Therefore, the selection of effective c-MET kinase inhibitors plays an important role in drug development and cancer treatment. Currently, there are 2 kinds of c-MET inhibitors in the clinic. One is the monoclonal antibody against c-MET. One is small molecule kinase inhibitors. Tivantinib (ARQ197) is the first ATP competitive c-met inhibitor. Tivantinib selectively inhibits non-activated c-MET and inhibits self-phosphorylation of c-MET.,13 In recent years, several targeted drugs have been reported to inhibit c-MET. In this study, a series of structural biological and chemical methods  were used to screen and identify lead compounds with potential regulatory functions for c-MET. Our study also predicted the absorption, distribution, metabolism, excretion, and toxicity of these compounds. This study provides a list of drug candidates and their pharmacological properties, providing the research object for the development of c-MET inhibitors.Natural products, as lead compounds, can be transformed into new drugs through appropriate structural modification, which is an important source of new drug research in the pharmaceutical industry.22.1Discovery Studio is a suite of software designed to simulate small and large molecule systems, which is designed to screen, design, and modify potential drugs through structural chemistry and structural biology calculations, thereby identifying and refining a wide range of lead compounds and candidate drugs approaches. The LibDock and absorption, distribution, metabolism, and excretion (ADME) modules of Discovery Studio 4.5 software  are applied in virtual screening. CDOCKER is used for docking research. Natural Products database in the ZINC database was used to screen c-MET inhibitors as a selection. The Irwin and Shoichet laboratories, which is in the department of pharmaceutical chemistry at the University of California, San Francisco, providing the ZINC database as a free commercial compound database.2.2 LibDock is a rigid docking program. It uses grids placed at binding sites and polar and non-polar probes to calculate protein hotspots. To form favorable interactions, the hotspots are furtherly used to align ligands, as well as the Smart Minimiser algorithm and CHARMm force field  for ligand minimization. All ligand positions were ranked by ligand scores after minimization. The 2.45 Å crystal structure of c-MET in conjunction with Tivantinib is downloaded from the protein database and imported into LibDock's work environment. The chemical structure of c-MET is shown in Figure  With a root mean square (RMS) gradient tolerance of 12.277, 2000 steps were performed in the minimization, which resulted in an RMS gradient of 0.09778. To define binding sites the prepared proteins were used, the Tivantinib binding site was selected as the active site for docking. Using LibDock, all prepared ligands were docked at defined active sites for virtual screening. According to the LibDock score, all docking positions are sorted and grouped by compound name.The ligand-binding pocket region of c-MET was selected to identify new compounds that might inhibit c-MET as the binding site. Virtual filtering is performed using the LibDock module of Discovery Studio 4.5.2.3The ADME module of Discovery Studio 4.5 is used to calculate the ADME of selected compounds, also used the DS4.5 toxicity prediction by Komputer assistive technology (TOPKAT) module to calculate all potential compounds toxicity and other properties, including its water-soluble, blood-brain barrier permeability, cytochrome P4502D6 (CYP2D6), liver toxicity, human intestinal absorption, plasma protein (PPB) levels, rodent carcinogenicity, Ames, respectively and developmental toxicity potential. These pharmacological properties should be taken into full consideration when selecting c-MET drug candidates.2.4,18 Next, remove the water molecules and add the hydrogen atoms to the proteins. The initial compound, Tivantinib, was extracted from the binding site and then realigned into the crystalline structure of c-MET to demonstrate the reliability of the combination pattern. The force field of CHARMm36 is applied to the receptors and ligands. The definition of the binding site sphere of c-MET is that as the region within a radius of 16 Å from the geometric center of mass of the ligand Tivantinib. The ligand is combined with the residues in the binding spot during the docking. When it was ready to identify the hit structure, and docking it into the c-MET binding pocket, the CDOCKER process was performed.,20 Based on CDOCKER interaction, different postures of each test molecule can be analyzed.The CDOCKER module of Discovery Studio 4.5 is applied for molecular docking research. CDOCKER can produce high-precision docking results as a molecular docking method on the basis of CHARMm36 field. While allowing the ligand to bend during docking the receptor remains rigid. For each complex posture, the CHARMm energy (interaction energy plus ligand strain) and interaction energy indicate the ligand-binding affinity. From the protein database, we can obtain the crystal structure of c-MET. During rigid and semi-flexible docking processes, crystallized water molecules are generally removed for fixed water molecules may affect the formation of receptor-ligand complexes.2.5The best binding conformations of each compounds-c-MET complex were chosen for molecular dynamics simulation. an orthorhombic box was built for the ligand-receptor complex was put into an orthorhombic box and solvated with an explicit periodic boundary solvation water model. Solidum (ionic strength of 0.145) chloride was poured into the system for the sake of simulating the physiological environment. Then, the CHARMM force field and energy minimization were prepared for the system (500 steps of steepest descent and 500 steps of conjugated gradient), with result showing that the final RMS gradient of 0.227. The system was slowly driven from an initial temperature (296 K) to the target temperature (320 K) in 2 ps, and equilibration simulations were performed for 5 ps. Molecular dynamics simulation (production module) was run for 25 ps and the time step was 1 fs. The simulation was run with the normal pressure and temperature system (300 K) during the process. Long-range electrostatics were calculated by the particle mesh Ewald algorithm, and all bonds involving hydrogen were fixed by the linear constraint solver algorithm. Select initial complex setting as a reference, Discovery Studio 4.5 analysis trajectory protocol was used for a trajectory determined for RMS deviation (RMSD), potential energy, and structural characteristics.Experiment to verify the therapeutic effect of the 2 selected compounds and c-MET expression in U251 cells.2.62 until the cells cover the bottom of the flask. Cells were passaged for just 1 time and cultured. The logarithmic growth phase of cells was selected for experimental use. Cell morphology was examined under a light microscope .U251 cell lines (GBM cell lines) were cultured in high glucose DMEM medium supplemented with 10% fetal bovine serum, cultured in a 37°C and 5% CO2.72 at 37°C for 72 h. The operation was carried out according to the instructions of the ELISA detection kit, and the c-MET expression of U251 cells was measured.U251 cells were seeded into 96-well plates at a density of 5 × 103/well, and each group had 3 duplicate wells. After 24 h, Tivantinib, Phyllanthin (ZINC5879645), and 4′-Hydroxycarvedilol (ZINC2528509) were added into 96-well plates with increasing drug concentrations and then cultured in 5% CO33.1The ligand-binding pocket played an important part in the regulatory sites of c-MET. Therefore, we chose this pocket region as the reference site. A total of 17,931 ligands were screened from the ZINC15 database, which was marked as for-sale, biogenic, and named. Select the chemical structure of c-MET as the receptor to contrast the pharmacologic properties between it and other compounds. The compounds which scored in the top 20 were listed in Table 3.2ADME module of Discovery Studio 4.5 was used to predict the Pharmacologic properties of the whole selected ligands with Tivantinib first, including aqueous solubility level, BBB level, CYP2D6 binding, human intestinal absorption level, hepatotoxicity, and PPB binding properties , as well as Ames mutagenicity were predicted using a computational method in the TOPKAT module Table . Consequ3.3To study ligand blinding mechanisms of these compounds with c-MET. ZINC000005879645 and ZINC000002528509 were docked into the molecule structure of c-MET by CDOCKER module, and CDOCKER potential energy was calculated and displayed as shown in Table 3.4For the sake of estimating the stabilities of the ligand-c-MET complexes in the natural environmental circumstances, a molecular dynamics simulation module was established. The molecular docking experiment was used to get the original conformations through CDOCKER module. RMSD curves and potential energy chart of each complex were shown in Fig. 3.5, and 4′-Hydroxycarvedilol (ZINC2528509) for 72 hours. The level of c-MET secretion in, Tivantinib, Phyllanthin, and 4′-Hydroxycarvedilol group was found lower than that in the blank group, and the level of c-MET secretion in Phyllanthin and 4′-Hydroxycarvedilol group was lower than that in the Tivantinib group. It is suggested that Tivantinib, Phyllanthin, and 4′-Hydroxycarvedilol group has an inhibitory effect on the level of c-MET secretion of U251 cells compared with the blank group 45, and 44 c-MET, encoded by proto-oncogene. Met, is a highly binding receptor tyrosine kinase belonging to the RON subfamily and is the only known receptor of scatter factor or HGF. The interaction between c-MET and membrane receptors affects the role of signal molecules such as HGF/c-Met signal pathway and vascular endothelial growth factor and its receptor, and further affects the process of tumor invasion, metastasis, and neovascularization, which leads to the emergence of tumor drug resistance, and is an important reason for the failure of drug therapy. Therefore, the key to inhibiting tumor growth is to find an inhibitor of c-MET to limit its activity, so as to resist tumor growth. At present, there are more than a dozen small-molecule c-met kinase inhibitors in the preclinical or clinical research stage used as single-drug therapy or in combination with other targeted drugs or chemotherapy drugs to treat multiple malignant tumors. As a result, the results of this study can also be applied to other tumors.GBM is the primary brain tumor with the highest incidence in the skull, among which GBM has a very high degree of malignancy. Even after radiotherapy and chemotherapy, the median survival of patients is very short. In addition, crizotinib is cytotoxic. Although most of the adverse events such as digestive symptoms and visual impairment were grade 1, other serious adverse events such as interstitial pneumonia, liver injury, and QT prolongation were also reported. Tivantinib (ARQ-197) (selected as a reference drug in this study) is an oral, highly selective, non-ATP competitive c-MET receptor tyrosine kinase inhibitor. It has been shown to be effective as a second-line treatment for a variety of solid tumors in early clinical trials. Therefore, there is an urgent need to screen more compounds targeting c-MET for clinical applications.At the moment, crizotinib, a therapeutic drug, has been approved by the Food and Drug Administration as a dual inhibitor of c-MET-ALK. But it also has some limitations. First, Crizotinib is resistant and a crizotinib-resistant tumor became susceptible to crizotinib retreatment in a non-small cell lung cancer patient. The future of Tivantinib, like many other drugs, depends on choosing the right patient. Some researchers have shown that patients with high expression of tumor MET showed great survival benefits compared with the placebo group; for patients with low expression of tumor MET, there was no difference between the Tivantinib group and placebo group, which indicated that Tivantinib still had a number of defects. Therefore, there is an urgent need to screen more compounds targeting c-MET for clinical applications.Although phase I and II trials of Tivantinib in second-line use showed encouraging results, the manufacturer's press release said that the phase III study of Tivantinib in the treatment of hepatocellular carcinoma did not achieve the ultimate goal of improving overall survival.In this study, LibDock, ADME/TOPKAT, CDOCKER, and Molecular Dynamics Simulation, 5 sections of Discovery Studio were used for virtual screening and analysis. As a result, 17931 biogenic-for-sale-named ligands were screened from the ZINC15 database for virtual screening. Compared with other compounds, compounds with a high LibDock score showed better energy optimization and a stable conformation. After the calculation of the module, 8827 compounds were found to be eligible to bind stably with c-MET than Tivantinib. The top 20 compounds were selected and pooled for further study on the basis of the LibDock score.ADME and toxicity predictions of the selected compounds were used to evaluate the pharmacologic properties of these compounds. Outcomes illustrated that ZINC000005879645 and ZINC000002528509 were regarded as safe drugs and chosen for the following study. Since they could dissolve in water and also had a good absorption level. Additionally, they did not have hepatotoxicity and they were noninhibitors of CYP2D6. Besides, these 2 compounds were also found to have less mutagenicity, rodent carcinogenicity, and developmental toxicity potential compared with other compounds. Therefore, ZINC000005879645 and ZINC000002528509 were regarded as safe drug candidates. For another, the remaining drugs still had a possible function in drug development despite they possessed toxicities or negative effects. In view of all the results above, ZINC000005879645 and ZINC000002528509 were selected as ideal lead compounds and further analysis was performed.The bonding mechanism and chemical bonds of the selected candidate compounds were also researched. CDOCKER module computation illustrated that the CDOCKER interaction energy of ZINC000008220033 and ZINC000001529323 was obviously lower than the reference ligand Tivantinib , which could indicate that these 2 compounds had a higher binding affinity with c-MET than Tivantinib.Finally, their stabilities in the natural environment were investigated by molecular dynamics simulation. Calculation of RMSD and potential energy of these ligand-MGMT complexes demonstrated the trajectories of complexes reached equilibrium after 18 ps. With time going by, RMSD and potential energy of these complexes got stabilized gradually, which showed ZINC000005879645 and ZINC000002528509 could interact with c-MET and the complexes were stable in the natural environment. On account of the results, these 2 compounds could be used for drug development and refinement.This study elucidated that the most important step in current drug designation was to screen ideal lead compounds. In this study, a battery of computer-aided virtual techniques was used to identify possible inhibitors of c-MET. LibDock is applied for structure-based screening followed by ADME and toxicity prediction.Molecular docking was conducted to confirm the binding affinity mechanism between the ligand and c-MET. Molecular dynamics simulations were used to assess the stability of ligand-c-MET complexes. The results showed these 2 compounds might have the most potential effect on GBM. But it is all known that no single drug could be directly marketed without thousands of refinement and improvement. Therefore, their refinement and improvement are of great significance in the following research. ovarian tumors, esophageal cancer, and GBM. Therefore, efficient compounds inhibiting c-MET can be exploited therapeutically. We chose the expression level of c-MET as the evaluation indicator to access the drug effect. In ELISA assay, the level of c-MET expression in Phyllanthin (ZINC5879645) and 4′-Hydroxycarvedilol (ZINC2528509) group was lower than that in the Tivantinib group. Consequently, the results demonstrated that the effect of Phyllanthin and 4′-Hydroxycarvedilol was better than that of Tivantinib in anti-GBM.Then, ELISA in vitro was carried out to evaluate the effects of potential compounds in the study. c-MET is overexpressed in carcinomas and other solid tumors such as small cell lung cancer in human,Although this study was well-designed and precise measurements have been conducted, it still has some shortcomings. Further experiments, for instance, animal testing, need to be performed to confirm our results, and more indicators, such as half-maximal inhibitory concentration and half-maximal effective concentration, should be assessed in the future.5This study conducted a battery of computer-aided structural and chemistry techniques  to screen and identify the ideal lead compounds with functions to possibly inhibit c-MET. Two compounds, ZINC000005879645 and ZINC000002528509, were selected as safe drug candidates, and they played important role in c-MET inhibitor development. Besides, a list of drug candidates with pharmacologic properties was provided, which could make a great contribution to c-MET or other proteins in medication design and improvement.YY Hou and HQ Xie designed experiments; WZ Yang wrote the manuscript; JL Ge, JA Ren, JC Li, and Jing Wang carried out experiments; GJ Dou, ZY Zhang, and XH Wang analyzed experiments results.Writing – original draft: Yuanyuan Hou, Haoqun Xie, Gaojing Dou.Writing – review & editing: Yuanyuan Hou, Gaojing Dou, Wenzhuo Yang, Junliang Ge, Junan Ren, Juncheng Li, Jing Wang, Zhiyun Zhang, Xinhui Wang, Baolin Zhou.


HCD with higher RH had a more positive influence on quality improvement. The L* values, the apparent stickiness, and the cooking properties of the noodle body were improved by HCD while good sensory and texture quality of noodles were still maintained after the dehydration process.Humidity-controlled dehydration (HCD) was innovatively applied in this paper to control the growth of microorganisms in fresh wet noodles (FWN). Effects of HCD treatment with different temperatures , relative humidity  and treatment time (5–32 min) on the total plate count (TPC), the shelf-life, and qualities of FWN were investigated. The results showed that HCD reduced the initial microbial load on the fresh noodles and extended the shelf-life up to 14–15 days under refrigeration temperature (10 °C). A 1.39 log Fresh wet noodles (FWN) are prone to be contaminated by microorganisms in production and distribution due to the high-water activity and rich nutrient content ,2. ThereA lot of research and attempt has been done for validation and improvement of the fresh-keeping techniques of FWN under room temperature. Decreasing pH by the addition of organic acid into fresh noodles had been proven to be an effective preservation method , while dw), and hurdle technology had been tried for preservation purposes in terms of process improvement in the FWN field [In addition to the above chemical methods, physical treatments, like heat and radiation could also kill microorganisms . Most prWN field ,11. MoreWN field . AlthougWN field .In general, the industrial drying process of noodle products was often at low temperature with divided steps, and the humidity of the hot air was usually taken into consideration for fine dried noodles, Udon noodles, and pasta products ,14. EmpiWheat flour was obtained from Yihai Kerry Grain and Oil Industry, and the protein, ash, and moisture contents were 11.28 ± 0.15%, 0.44 ± 0.09%, and 13.18 ± 0.07%, respectively. The table salt used in the noodles was from the local supermarket. Other reagents used were of analytical grade.The formula of the fresh wet noodle in this study consisted of 1000 g of flour, 340 mL distilled water, and 10 g NaCl. For noodle processing, the flour, distilled water, and NaCl were put into a vacuum mixer  and mixed for 7 min under a vacuum degree of −0.08 MPa to form the noodle dough. The dough was put into a plastic bag that was sterilized by ultraviolet radiation beforehand and then rested for 25 min at 25 °C. Then, the dough was passed through a small roller noodle machine  gradually. The thickness was reduced from 2 mm to 1.5 mm with the roller gap and finally reduced to 1 mm to obtain a dough sheet. The dough sheet was passed through the noodle machine to get the resultant noodle strands with the dimensions of 1.0 mm in both width and thickness. The water content of the noodle body was about 34% after noodle preparation.The above fresh noodles were thermally treated by using automatic noodle drying equipment . The dehydration temperature and relative humidity were adjusted to 40, 60, 80 °C, and 50%, 70%, 90% with different combinations before operations. In this paper, the noodle sample treated under the temperature of 40 °C and RH of 50% was abbreviated as sample “40 °C-50%” and so on. Since the dehydration speed varied according to the thermal treatments, the dehydration time was different depending on the conditions when the water content of all the noodle samples was reduced from 34% to the same level (about 30%). The moisture content variations and the corresponding dehydration time of the HCD treated noodles were listed in The HCD treated noodles (25 g) in different storage stages were sampled, pulverized, and mixed with 225 mL of 0.85% aseptic physiological saline. The mixture was homogenized by a stomacher machine  for 60 s before transferred to make different series of dilutions using 0.85% aseptic physiological saline. 1 mL of appropriate dilutions was pipetted onto sterile plate count agar plates and incubated at 36 °C for 48 ± 2 h before the examination of the total plate counts (TPC) according to GB/T 4789.2-2016 . The yeaL* value of the HCD treated noodles in different storage days were measured by a Chroma Meter  equipped with a D65 illuminant. Ten thin strips of the noodles were closely arrayed as a line, and measurement was carried out at 4 testing points on the surface of each noodle sample. L* is a measurement of noodle brightness  according to CIE L*, a*, and b* system, and each of the sample points was tested three times.The change of V0 is the volume (mL) of sodium thiosulfate consumed by a blank sample, V1 is the volume (mL) of sodium thiosulfate consumed by a fully gelatinized noodle sample, V2 is the volume (mL) of sodium thiosulfate consumed by the ungelatinized sample.The degree of gelatinization in the noodles was measured based on the starch-iodine complexes reaction, according to the method reported by Wootton et al. . The HCDThe cooking loss of the HCD noodles was determined as described by AACC Method 66–50 . The rawThe texture properties of the uncooked and cooked HCD noodles were determined using a TA-XT2i texture analyzer . The P/35 probe was used to measure the apparent stickiness of uncooked HCD noodles. The hardness of cooked HCD noodles was measured according to the description of Wu et al. with some modifications . Fresh wThe uncooked and cooked HCD fresh noodles were prepared for sensory evaluation using quantitative descriptive analysis (QDA) according to the method of Costa et al. . The senThe morphology of fresh wet noodles after the HCD treatment under different conditions was investigated using a scanning electron microscope . Noodle samples were rinsed, eluted, and freeze-dried. The samples were then mounted with double-sided carbon adhesive tabs on aluminum stubs, and coated with gold-palladium. The surface and cross-section of the noodles were observed and photographed at an accelerating voltage of 1.0 kV.p < 0.05) was applied to determine if a significant difference existed between the two mean values.All of the above-mentioned tests were carried out in triplicate and the results are expressed as the mean ± standard deviation. SPSS 17.0 software  was used for the analysis of variance (ANOVA), and a significant difference between any two means was calculated by using Duncan’s multiple range tests. A 0.95 confidence level (p < 0.05) with the increase of relative humidity or temperature, respectively. In this study, the moisture content of fresh wet noodles was settled to the same level of 30% to evaluate the effect of HCD on storage quality of fresh wet noodles. Therefore, the RH and HCD time would depend on each other, since, at higher RH, the time needed to dry the product is longer due to the lower moisture gradient between product and air. This result indicated that HCD could inhibit the growth of microbes to a certain degree, and it had a more positive effect under the condition of either higher RH and temperatures, or longer HCD time. By comparison, the initial TPC of 40 °C-70%, 60 °C-70% and 80 °C-70% samples were lower than that of the control by 0.37, 0.85, 1.54 log10 CFU/g, respectively, and a maximum inactivation level of 1.94 log10 CFU/g for the initial TPC of the HCD noodles was achieved in this study under the conditions of 80 °C-90%. As mentioned by Chau et al. [10 reduction) after 3 min of thermal dehydration. All the microorganisms, no matter it is spoilage or pathogenic bacteria, prefer to grow in high-aw conditions and some foodborne pathogens were able to survive in foods with low aw as well as in dry environments [10 reduction) was achieved for yeasts and molds in FWN when the RH was increased to 90%. A high level of relative humidity in environments should have led to a large number of microbes growing, but the high-moisture hot air during HCD induced microbial cell killing instead. Therefore, HCD with higher RH (longer HCD time) had a more positive influence on reducing both TPC and YMC, and we speculated that some heat-resistant bacteria could be inactivated under high temperatures with higher humidity.The effect of HCD on the initial bacterial content including TPC and YMC was shown in u et al. , heat tru et al. . Inspireu et al. ,24. In tronments ,26. Exce6 CFU/g and hence the quality analysis of noodle samples would be terminated in this study [10 CFU/g would quickly exceed the threshold level in 3–4 days during storage at 10 °C, and soon the fresh wet noodles would deteriorate. After HCD treatment, the shelf-life of FWN was extended up to 9–15 days with the increase of treating temperature and RH. The initial TPC is one of the most important factors that affect the shelf-life of fresh wet noodles, and in general, the shelf-life of FWN with a lower initial bacterial load could be prolonged. After HCD treatment, the initial TPC of sample 60 °C-90% was reduced by 1.39 log10 CFU/g compared with the control, and the shelf-life of which was extended up to more than 12 days. Since there was no significant difference (p > 0.05) in initial TPC between the sample 40 °C-90% and 60 °C-50%, and between the sample 60 °C-70% and 80 °C-50%, we could not distinguish the corresponding samples (with same water content of 30%) in terms of TPC variations and shelf-life.According to the report of Li et al. , the freis study . As showThe change of YMC of FWN during storage was similar to that of TPC and was listed in L* value during storage  and were increased to some extent with the increase of dehydration temperature which indicated a brighter color. This was mainly due to that moderate thermal treatment could inactivate enzymes especially the polyphenol oxidase [L* value (ΔL) was 6.95 after 3 d of storage for sample 40 °C-50%, which was only 0.83 for sample 80 °C-90%. For HCD samples treated at 60 and 80 °C, the change of L* value during storage was less with increasing relative humidity from 50% to 90% since the dehydration time was accordingly extended from 3–5 min to 18–23 min, respectively . The micrographs of the surface A–F and tMaintaining integrity during cooking is crucially important for improving noodle quality . After tThe tensile force and hardness of the cooked HCD noodles were primarily affected by the dehydration temperature, and then the relative humidity. Wagner et al.  have repChanges in sensory properties for uncooked and cooked HCD noodles were listed in In this study, thermal dehydration with humidity-controlled hot air was innovatively applied as an effective way to control the initial microbial load in the fresh wet noodles before storage. HCD treatment could significantly reduce the microbial load in noodle bodies and prolong the shelf-life. The storage stability of color and apparent stickiness of the FWN was greatly improved after the humidity-controlled dehydration process, meanwhile, the textual and cooking properties also benefited a lot from the process. The humidity-controlled dehydration treatment seemed like a promising technique to pretreat the fresh wet noodles before packaging and distribution. However, further research is needed to optimize the conditions depending on the water content added in practical production when considering the economic benefits.


Concrete is susceptible to damage during and after high-temperature exposure (most frequently in fire). The concrete partial strength re-gain after a high-temperature exposure obtained by the rehydration process is undoubtedly an advantage of this construction material. However, to use fire-damaged concrete, one has to know why the strength deteriorates and what makes the partial re-gain. Within this framework, the paper aims to find what factors influence the strength re-gain. Moreover, an attempt is made to introduce a measure collecting various influences such as the modified heat accumulation factor—accounting only for that which is important for the process, the temperature decomposing cement paste . Several factors, i.e., peak temperature, heating time and rate, cooling regime, post-fire re-curing, concrete composition, age of concrete at exposure, porosity, load level at exposure, and heat accumulation are presented by their influence on the relative residual compressive strength, i.e., a portion of initial strength that is obtained after temperature exposure and strength re-gain. Since the relative strength unifies various concretes, a more general assessment and discussion are presented based on the experimental results and correlation factors. As fundamental influences determining the residual strength, the heating time, peak temperature, cooling, or post-heating re-curing regimes are found with the load level at exposure being inadequately examined. This paper also shows the superiority of the modified heat accumulation factor, but the results obtained are not satisfactory, and additional experimental data are necessary to develop a theoretical model of the residual strength. Concrete provides the best fire resistance out of typically used construction materials. Compared to timber or steel, concrete has low thermal conductivity, high heat capacity, and its strength degrades slower with increasing temperature. As a result, it is a material that performs well not only as a separator between fire-affected spaces but also as a material for elements that need to perform under extreme thermal conditions. The vast majority of concrete structures can withstand fire conditions for the designed duration. This is due to the fact that concrete properties at high temperatures are well known and examined .Standards provide safe approaches and mathematical models ,3,4 thatDestructive and non-destructive assessment of strength is possible ,12,13,14From both research and practical perspectives, the residual strength of concrete is a complex matter , because-At 100 °C, bound water is being evaporated;-At 180 °C, hydrate calcium silicate is beginning to dehydrate;-At 500 °C, the decomposition of calcium hydroxide is observed;-At 700 °C, the decomposition of calcium silicate hydrate occurs.Since concrete is a composite material , its final properties vary depending on the ratio and type of components used, but subjected to fire, other variables influence the properties. When a cement paste is exposed to high temperatures, the following physicochemical reactions are observed :-At 100 These phenomena cause a degradation of the mechanical properties of the cement paste . In addiAfter the concrete is cooled down to ambient temperature, it retains residual strength that is affected not only by the mentioned factors but also by the cooling regime, post-fire re-curing regime, and time. There exists a correlation between strength at high temperature and residual strength, but they cannot be treated in the same way.This review paper summarizes up-to-date progress in experimental research on the residual strength of concrete after high-temperature exposure. The results of the tests on the most important factors that influence concrete residual strength are presented and discussed in the following sections of the article. Each section is dedicated to a separate factor. Although there are consistent results for obvious factors, such as peak temperature and heating time, the influence of less pronounced factors, such as the w/c ratio and cement type, still requires further research. Furthermore, current research lacks a general approach to the influences that will lead to a function or algorithm capable of assessing the residual strength of concrete.According to , the strIn ,24,25, cThe HSC (high-strength concrete) samples  and the Moreover, the results demonstrate that the relative loss of strength is higher for HSC than for NSC. A similar conclusion was reached in ,33. Corr-Normal-strength concrete (NSC) with a w/c ratio of 0.5;-High-strength concrete (HSC) with a w/c ratio of 0.37.The heating time, that is, how long the peak temperature is kept, is crucial in assessing the residual strength of concrete, which is demonstrated in the research presented . In 23]23], thisAt 28 days, samples were heated at a rate of 10 °C/min to target temperatures 300, 500, and 700 °C and kept for 1, 3, 6, and 9 h. The samples were tested after 24 h of cooling at room temperature . In 36]36], concCylindrical samples (100 mm in diameter and 200 mm high) were tested in  at the aCylindrical specimens were also tested in  by exposData reported by different authors result in the strength dispersion presented in Although the gas temperature in a fire can rise extremely fast, as presented in Although there are very different heating rates (3.5 and 10 °C/min) in , the tes-High-temperature environment cooling—concrete and environment maintain a high temperature for a long time, and slow temperature lowering from peak value to ambient is performed. This type of cooling corresponds to what happens in the inner parts of the fire-affected elements. The relatively high thermal capacity of concrete and low thermal conductivity cause temperature changes inside elements to be slow, both during heating up and cooling down.-Cooling at the ambient temperature environment—hot concrete is kept at room temperature for cooling. This can be equated to the occurrence in the outer parts of fire-affected elements.-Water cooling—hot concrete is treated with cold water and cooled down. This type can be compared with the outer parts of fire-affected elements covered by water used to extinguish the fire.After heating or a fire, an element subjected to high temperature cools down, and how it happens is called the cooling regime. There exist three basic types of the regime used in tests:According to the available research , the deg2 accompanied by the expansion and thus further deterioration of concrete.Similar tests are presented in ,42,43, aIn , cubic sCubic specimens (100 mm) specimens were tested 90 days after casting in . TemperaIn , water aA difference in the cooling regime for various peak temperatures is presented in . TemperaThree cooling methods were examined in : that isThe cooling regime is an important factor in the evaluation of the residual strength of the concrete. According to , rapid cThe available data indicate that water cooling results in lower residual strength directly after cooling. Nevertheless, after post-fire re-curing, the difference between residual strengths for different cooling types becomes small and can be neglected.The recovery of the strength of concrete due to post-fire re-curing is important when assessing the residual strength of concrete, and it was proven in many articles . This reThe difference between them is defined by the supply of water, from full immersion for a whole amount of time to no water at all. In , concretIn , variousThe re-curing method shows differences in the first 7 days, water re-curing rates at 100% of increase, while air curing rates at 50%, but later, the growth becomes linear and very similar for both methods. In , concretIn , the resSelf-compacting concrete samples were examined in  by heatiInitially, the insufficient concrete strength over time can become high enough to carry the necessary stresses. Correlation calculated for re-curing time and residual strength displays a positive relation  and is expected to have an essential influence on the behavior of concrete. A comprehensive study on aggregate behavior at elevated temperatures in  providesIn , residua2 content) after exposure to elevated temperatures (from 200 to 1000 °C). The results showed that the crushed aggregate regained a higher residual strength value. In [In , a compaalue. In , researcalue. In  researchIn , the recIn , tests wResearch carried out on the influence of aggregate type on relative residual strength proves that the limited influence exists and the change is especially noticeable for heavy-weight concrete . In the Concrete strength is among other functions a function of the water to cement ratio, so naturally, it influences residual strength. Very few papers tackle cement dosage, and even fewer address cement types. In , concretOther w/c ratios (0.31 and 0.45) were examined in . For allIn , concretFour types of concrete with fly ash replacement for Portland cement were tested in . The infThe role of peak temperature and fly ash dosage on the residual strength of lightweight concrete was examined in . The levIn , the resAnother cement replacement, ground granulated blast furnace slag (GGBFS), was investigated in . Mixes wThe available test data prove that the w/c ratio does not have a big influence on the residual strength; only in cases of drastically different ratios, the initial strength differs by a noticeable margin. The rate at which the concrete regains strength is similar for all tested w/c ratios. The cement type (binder additives) is crucial; pozzolans or slag  plays anMany additives can improve concrete properties. Macro-additives, such as polypropylene or steel fibers  and micrPP fibers improve residual compressive strength directly after cooling but to a very limited degree. It should not be taken into account when assessing the residual strength of concrete. More tests need to be performed on the influence of PP fibers on the re-curing rate. Channels made by melted PP fibers are impossible to repair, as they do not regenerate. The pore structure of concrete without PP can be restored to a value similar to the initial one, while concrete with PP cannot regain its previous state. In , it was Porosity, pore size, and pore distribution are the primary factors influencing the strength, durability, and permeability of concrete. Research already done in this area is collected in In , an MIT An interesting relation was observed in , compariPorosity is rapidly growing, with temperature increasing above 400 °C and having a great impact on the strength of concrete. The calculated correlation factors between porosity after exposure and residual strength shows a significant negative porosity influence . This reFire can happen in a building regardless of its age. Both very old buildings and new buildings (or even still under construction) can experience exposure to fire situations. The behavior of concrete at high temperatures will be different in the mentioned cases. Moisture and the amount of concrete that was already hydrated influence both hot and residual strength but also the re-curing rate. In ,116, conThe level of load at exposure is an important issue that needs to be addressed, as every building is constantly subjected to loads. Strength at high temperature is positively affected by load level, as it reduces the speed of decrease of strength ,119,120.The hot and residual strengths of concrete depend on the dehydration of the cement gel. Dehydration is mainly related to high exposure to heat, both the peak temperature and the exposure time. The factor that evaluates high-temperature exposure is the heat accumulation factor. It is defined as the area under the temperature–time curve. This idea was proposed in , and varThe heat accumulation factor can be calculated in two ways , as origH400 follows a certain decreasing line  was again higher in the Hr400 variation. However, the data of NSC and HSC behave similarly. With this in mind, for future reference, NSC and HSC can be treated identically, and separation is unnecessary.Thus, nonlinear exponential fitting was made. The RAlthough experimental research on the residual strength of concrete is extensive, the results appear to be incomplete. The main factors influencing residual strength  are already identified. Other factors, but with less pronounced effects  have also been examined. However, some factors do not contribute to the strength, such as common additives, or the influence is not straightforward, such as porosity. However, with this in mind, experimental research can be limited to the temperature range 300–700 °C because the residual strength for temperatures up to 300 °C and more than 750 °C can be obtained only on the basis of the peak temperature. Moreover, the limit of two hours of high-temperature exposure can be used, as the main strength loss occurs within this period, and later, the impact is minimal.Both essential factors influencing the residual strength  exhibit a negative linear influence on the residual strength, while for the other factors, the influence is not so straightforward, as the correlation factors are smaller. Thus, nonlinear functions would properly govern these relationships. Furthermore, the influence of the peak temperature on the residual strength is not as direct as on the hot concrete strength. Only the strength directly after cooling is highly dependent on the peak temperature reached. A similar conclusion is drawn for the cooling regime; e.g., for water cooling, its negative impact is apparent in the early stage of recurring but for the longer re-curing time, the impact diminishes. The influence of rapid cooling is also limited to the external layers, and it is not deciding for whole structure load capacity.What should be stressed is the ability of concrete to regain its strength due to the rehydration of cement paste. Therefore, re-curing time and type are crucial for assessing the residual strength of concrete. From this perspective, it is not surprising that the influence of the w/c ratio can be omitted. However, there are reports where a lower w/c ratio results in a higher residual strength. This problem may be posed by cement type, as there is not enough comparative research focusing on the type of cement and its influence on residual strength. There exists also an indirect relationship between rehydration and porosity that requires further research. Porosity is notably higher after high-temperature exposure, and reversal is possible if the temperature was not greater than 800 °C. Moreover, lower porosity results in higher residual strength directly after cooling, but after re-curing, this difference is equalized.The time after cooling and its type also regulate the residual strength. Directly after water cooling, a lower residual strength is obtained. Nevertheless, the re-curing significantly reduces the influence of cooling type. However, additional consideration of these phenomena is necessary for the external part of an element that is severely damaged. The internal part, which is crucial from a residual strength point of view, is immune to damages caused by different types of cooling. The interaction between layers of heated and cooled concrete should also be studied. The transient temperature field and associated strain and stress can contribute to material damage and strength reduction. Moreover, the possible volume changes due to chemical reactions and thermal expansion would also be considered.There is also a need for more research on the influence of PP fibers on regaining residual strength. Changes in concrete structure left by PP fibers are evident, and their impact needs to be assessed. More research is also needed to determine the relation between preload level and residual strength, as it can be important in practice.Hr400 gives more coherent results than the unmodified H400 as demonstrated by correlation factors, and therefore, it can be used to assess the residual strength of concrete.Since the ability of concrete to regain its strength due to rehydration determines the residual strength, only temperatures above 400 °C should be taken into account, because the decomposition of cement paste starts at this temperature. The modified heat accumulation factor The research presented in the paper signifies the determination of the peak temperature and the heating time of the residual strength. The other factors do not directly influence the residual strength. However, as concrete regains its strength due to the rehydration of cement paste, the re-curing time and type are also crucial factors.The proposed modified heat accumulation factor can be considered as a measure that collects all influences. However, more research needs to be done to increase accuracy and prove that the modified accumulation factor is universal, i.e., if in changing experimental conditions, the same values of the factor are associated with the same values of the residual strength. If not, other measures of damage should be considered.If the other measures of damage are proposed, they should take into account that the derivative of residual strength regarding heating time is constant, and the residual strength can be described as a logarithmical function of re-curing time and type. Thus, to create a function that will precisely assess the residual strength of concrete, one needs to solve an equation system that takes all influential variables into account. Considering only part of the variables will result in an approximate solution. A comprehensive function of residual strength can be found only after the above-mentioned factors, extended by necessary research, are rationalized by mathematical function, compressed to the equation system, and then solved.


Antimony (Sb) is a trace element applied widely in modern industry. A large number of tailing solid wastes are left and accumulated in the mining area after purifying the precious antimony from the antimony ores, causing serious pollution to the environment. The major aim of this study is to investigate the feasibility of utilizing antimony tailing coarse aggregate (ATCA) as a complete substitute for natural coarse aggregate (NCA) in high-strength concrete. Concrete specimens with 25%, 50%, 75%, and 100% ATCA replacing the NCA in conventional concrete were prepared for evaluating the performance of ATCA concrete. The investigators find that ATCA concrete has good workability, and the mechanical properties and long-term behavior (shrinkage and creep) of ATCA concrete with all replacement levels are superior to those of NCA concrete. The durability indices of ATCA concrete, such as the frost-resistant, chloride permeability, and resistance to carbonation, are better than those of NCA concrete. While the alkali activity and cracking sensitivity behavior of ATCA concrete seem to be decreased, nevertheless, the difference is not significant and can be neglected. The researchers demonstrate that all of the control indices of ATCA concrete meet the requirements of the current industry standards of China. Overall, ATCA can be used in concrete to minimize environmental problems and natural resources depletion. Concrete is one of the most popularly used building and construction materials and has been widely researched ,2,3. In China is the largest consumer and producer of concrete in the world. Meanwhile, China has the richest antimony deposits in the world and produces millions of tons of antimony ore tailing. Since the beginning of the 20th century, China has become the world’s largest producer of antimony and its compounds . A largeMetal tailing has long been considered a worldwide environmental problem for the earth and aquatic pollution ,13. Thes2 emission in the concrete production process.Onuaguluchi and Eren ,20 invesZhao et al.  studied As mentioned above, although the literature on other metal ore tailing utilizing in concrete is relatively rich, little investigation on the utilization of antimony ore tailing as CA has been reported. The goal of this research is to study the feasibility of ATCA as a complete substitute for natural coarse aggregate (NCA). The workability, mechanical property, long-term performance, and durability of ATCA concrete and NCA concrete are studied and compared in the present work.The rest of this paper is organized as follows. 3, the specific surface area was 312 m2/kg, the normal consistency was 27.7%, and the initial and final setting time was 168 min and 207 min, respectively. The compressive strength of cement mortar at 3 days, 7 days, and 28 days iwas 26.7 MPa, 38.5 MPa and 52.8 MPa, respectively. The main chemical composition of cement is shown in In this investigation, Ordinary Portland cement with a strength class of 42.5, in accordance with Chinese Standard GB 175-2007 was used . For theThe ATWR was obtained by 5-point sampling method in the antimony waste ore stacking area in Xikuangshan (XKS). The XKS Sb mine, located near Lenshuijiang City, Hunan Province, China, is the largest Sb mines in the world ,38,39. DThe concrete mix proportion was determined through multiple trial mixes with the absolute volume method. Poly-carboxylate superplasticizer was added to concrete with 0.2% by the weight of cementitious materials. The workability of fresh concrete is a key factor in assessing whether it can be applied to construction projects. CA is the largest component of the concrete mix ratio, playing an important role as the skeleton. The shape and particle size of CA will affect the construction performance of concrete. The slump, air content, setting time, and apparent density was tested based on the Chinese Standard GB/T 50080-2016 . The worThe workability of fresh concrete, such as the slump, setting time, air content, and apparent density, is listed in It is important to understand the development of strength, especially at the early age of concrete structures ,48. The As illustrated in The tensile strength of concrete is a vital factor in evaluating the crack resistance of structures . The splThe test result of prism compressive strength and elastic modulus for NCA concrete and ATCA concrete are shown in 4 MPa, 3.94 × 104 MPa, 4.04 × 104 MPa, and 4.11 × 104 MPa, respectively. Compared with T0, the percentage increase was 3%, 4%, 7%, and 9%, respectively. While for the long-term elastic modulus, when the curing age was 180 days, the percentage increase was 3%, 6%, 9%, and 11%, respectively. Since compressive strength is an adequate index for mechanical properties, a close relationship exists between compressive strength and elastic modulus of ATAC concrete.As can be seen, from In this section, the mechanical behaviors such as cube compressive strength, splitting tensile strength, prism compressive strength, and elastic modulus of all the samples were tested simultaneously. The results show that the mechanical behavior of ATCA concrete with all replacement levels were superior to NCA concrete. Furthermore, at a certain curing age, the mechanical behavior of concrete containing ATCA is enhanced with the increased replacement level. This might be due to the superior mechanical property of ATCA, and better bond between cement and ATCA for the irregular surface. In related research, Shettima et al.  reportedThe shrinkage of concrete is one of the main causes of structural cracking . The CA The drying shrinkage and creep were tested simultaneously in the laboratory with constant temperature and humidity based on the Chinese Standard GB/T 50082-2009 . The dim−6, 309 × 10−6, 315 × 10−6, 318 × 10−6, and 329 × 10−6, which were, respectively, 3%, 4%, 6%, and 9% less than those of the controlled sample.The test results of drying shrinkage are shown in The creep tests of concrete specimens with loading ages of 7 days and 28 days were conducted, and the creep coefficients were used to denote the creep performance. The test results are shown in In this section, the drying shrinkage and creep of all the samples were tested at the same time. The results showed the drying shrinkage and creep of ATCA concrete with all replacement levels were superior to those of the controlled sample. Furthermore, the drying shrinkage and creep of ATCA concrete decreased with the increased replacement level of ATCA. The factor for lower drying shrinkage and creep of ATCA concrete could be attributed to the higher compressive strength of ATCA, and better bond between cement and ATCA. To further study the feasibility of ATCA for concrete, the durability behavior is discussed in the next section.Durability is the most critical factor affecting the life cycle of concrete structures. Some indices such as freezing and thawing, carbonation, and chloride ion penetration have been investigated in the related studies. Since there may be some impurities in the tailing aggregates, the cracking sensitivity and alkali activity should be paid attention to as well. In this section, the durability performance such as freezing and thawing, alkali activity, chloride ion penetration, cracking sensitivity, and carbonation was studied systematically. The dimensions of the specimens used for the experimental study are listed in The frost resistance ability of concrete is expressed by surface peeling and relative dynamic modulus of elasticity, which is measured by the ultrasonic method . The tes2O, Na2O) in the concrete, causing expansion, crack, or even damage in concrete. In order to evaluate the alkali-silicic acid reaction of ATCA aggregates, the alkali activity experiment was conducted. For 14 days, all samples were placed in the NaOH solution, of which the concentration was 1 mol/L, and the temperature was (80 ± 2) °C. The length of the sample was measured, by which the expansion rate of length was calculated, and the alkali activity of aggregate was evaluated.Under complex conditions, certain minerals in the aggregate could react chemically with the alkali .High-strength concrete structures are more prone to cracking , and craThe test result of carbonation depth is shown in (1)ATCA as a complete substitution for NCA in concrete possesses good workability, which is nearly the same as NCA concrete.(2)ATCA as a complete substitution for NCA in concrete possesses perfect physical and mechanical properties. The cubic compressive strength, cubic splitting tensile strength, prism compressive strength, and elastic modulus of ATCA concrete with all replacement levels is superior to that of NCA concrete.(3)The drying shrinkage and creep of ATCA concrete decrease with the increased replacement level of ATCA. Furthermore, the drying shrinkage and creep of ATCA concrete with all replacement levels are superior to the controlled sample.(4)The ability of resistance to carbonation, the frost-resistant, and the chloride permeability performance of ATCA concrete are enhanced. While the alkali activity and cracking sensitivity behavior of the samples with ATCA seem to be decreased. Nevertheless, the difference is not significant and can be neglected.(5)It is found that all of the control indices meet the requirements of the current industry standards of China. The utilization of ATCA as a complete substitute for NCA in high-strength concrete has very important environmental and economic benefits.Based on the systematical studying of the performance of antimony tailing coarse aggregate (ATCA) concrete and the comparison with natural coarse aggregate (NCA) concrete, the researchers have the following main conclusions:


This review summarizes currently available literature for or against a role of AMPK in MET-mediated protection against DOX cardiotoxicity. It also highlights the emerging evidence suggesting distinct roles of the AMPK subunit isoforms in mediating the functions of unique AMPK holoenzymes composed of different combinations of isoforms. Moreover, the review provides a perspective regarding future studies that may help fully elucidate the relationship between MET, AMPK and DOX cardiotoxicity.Doxorubicin (DOX) is an extremely effective and wide-spectrum anticancer drug, but its long-term use can lead to heart failure, which presents a serious problem to millions of cancer survivors who have been treated with DOX. Thus, identifying agents that can reduce DOX cardiotoxicity and concurrently enhance its antitumor efficacy would be of great clinical value. In this respect, the classical antidiabetic drug metformin (MET) has stood out, appearing to have both antitumor and cardioprotective properties. MET is proposed to achieve these beneficial effects through the activation of AMP-activated protein kinase (AMPK), an essential regulator of mitochondrial homeostasis and energy metabolism. AMPK itself has been shown to protect the heart and modulate tumor growth under certain conditions. However, the role and mechanism of the hypothesized MET-AMPK axis in DOX cardiotoxicity and antitumor efficacy remain to be firmly established by  This mini-review will extract evidence from currently available literature for or against a role of AMPK in MET-mediated protection against DOX cardiotoxicity. For the effects of MET and AMPK in antitumor therapies, the readers are referred to other review articles published elsewhere (The anthracycline doxorubicin (DOX) has been widely used for over 5 decades and is a highly effective chemotherapeutic agent for the treatment of a broad spectrum of cancers including various solid tumors and leukemia. Unfortunately, DOX chemotherapy can cause severe cardiotoxic effects –3. Acutelsewhere –24.per se  including superoxide anions . Apparently, further clinical trials are needed to confirm the cardioprotective effects of MET in cancer patients treated with DOX. MET has been suggested to antagonize DOX cardiotoxicity through several mechanisms (left panel in Metformin (MET) is an oral biguanide agent that was first utilized to treat diabetes in France in 1957  and apprper se should improve the application of DOX in antitumor therapy.Several epidemiological studies, meta-analyses and animal studies have revealed that MET has anti-neoplastic and chemopreventive activities , 81 despin vivo.AMP-activated protein kinase (AMPK) is a heterotrimeric protein kinase composed of a catalytic α subunit and two regulatory subunits (β and γ). Each subunit has multiple isoforms encoded by distinct genes , and they combine to form 12 different AMPK holoenzymes . All isoin vivo in immunodeficient mice  to QL and a research grant from the American Osteopathic Association  to TN.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.