In a previous work, conductive concrete, based on amorphous carbon with a mechanism that operates as a microbial fuel cell was investigated. The objective of the present study is to develop additional materials for highly conductive concrete, to mitigate the concentration of H2S in sewer pipes. Adsorption experiments were conducted to elucidate the role of the H2S reduction. Additionally, electricity-producing bacteria (EPB), isolated from a municipal wastewater treatment plant, were inoculated to improve the H2S reduction. The experimental results showed that inoculation with EPB could decrease the concentration of H2S, indicating that H2S was biologically oxidized by EPB. Several types of new materials containing acetylene black, or magnetite were discovered for use as conductive concrete, and their abilities to enhance the biological oxidation of H2S were evaluated. These conductive concretes were more effective than the commercial conductive concrete, based on amorphous carbon, in decreasing the H2S concentration in sewer pipes.Hydrogen sulfide (H The growing sanitary infrastructure, including sewer pipeline networks and effluent wastewater systems, is an undesirable trend for managers who must increasingly accommodate a larger portion of their finances for their operation and maintenance. Hydrogen sulfide  [2S from the anaerobic slime layer of sewer pipes is to design the optimal gradient and flow velocity to prevent the trapping of grit and organic sediments. Despite their efficacies, these approaches suffer from several major drawbacks when applied to real conditions on a larger scale. There are similarities between the H2S removal by the oxygen injection and air pressurization, as described by Gutierrez (2008) and Mohanakrishnan (2008). These methods have the advantages of organic matter obliteration, acidic gas control, and environmentally friendly treatment [2S in a short time and has a good oxidation potential. A variety of chlorines that are used as disinfectants are highly reactive and readily oxidize sulfur to sulfides. However, the residual chlorines, even at low concentrations, are hazardous to the aquatic environments. Devai and Delaune (2002) proposed potassium permanganate to be the most effective chemical, followed by hydrogen peroxide and sodium hypochlorite, in reducing the sulfide products [Several studies on the biocorrosion of concrete sewers have heightened the understanding of the mechanism of concrete deterioration by H2S ,7,8,9,10reatment ,12,13,14reatment ,16. Presreatment . The useproducts . Howeverproducts . 2S emissions in sewer pipelines, the inhibition of the sulfate-reducing bacteria (SRB) activity also contributes to a low H2S-related pipe damage. Another approach to control H2S is the pH elevation shock for the deactivation of anaerobic bacteria. The supplementation of magnesium hydroxide or sodium hydroxide to increase the pH to 9–12 in a rapid contact time, can inhibit SRB in the slime layer by 50% with a long effective period (up to a few weeks) and prevent H2S from forming a gas phase [2O2) for 6 h or longer [Several studies have shown that in addition to the chemical oxidation that suppresses the Has phase . This isas phase ,21,22. Jr longer . However2S emersion and corrosion in sewers disregard the fact that there are many long-standing pipelines. The corrosion problem of sewer systems in a state of deterioration and collapse remains a concern for global authorities under the budget and operating maintenance pressures. Further investigations are thus required to establish the feasibility of real sewer infrastructure and a more economic efficiency. However, the aforementioned studies conducted to mitigate the H2S formation in the anaerobic sediment. Previously, conductive concrete, based on amorphous carbon, which operates as a microbial fuel cell (MFC), was developed. This method employs movement through the electronic pathway from the sediment layer to the surface water through the conductive concrete material. Thus, SRB can be easily activated, significantly decreasing the biogenic corrosion issues. Herein, the mechanism of conductive concrete using different materials and the contributions of electricity-producing bacteria (EPB) to the reduction of generated sulfide were elucidated. First, the mechanism by which the commercially used conductive materials suppress the H2S inhibition was investigated. Then, trials using new conductive materials, combined with the EPB inoculation were conducted to verify the biological oxidation of H2S reduction. Finally, the new conductive concrete was assessed to determine the effect of the H2S reduction.To overcome the limitations of previous studies, research was conducted to provide preventive solutions to obtain a more sustainable material, to combat the biocorrosion of concrete sewers and to minimize the H2S is generated by the sulfate-reducing bacteria in the anaerobic environment of the biofilm layer. Previous work has concentrated on elucidating the H2S reduction in three ways: adsorption on amorphous carbon, chemical oxidation, and biological processes. One possible explanation for this is the combination of the adsorption capacity of conductive substances and the biological oxidation. An experimental scheme in which an electronic pathway is blocked inside the conductive concrete has no effect on the sulfide reduction. The only way to reduce H2S formed in the conductive concrete is via biological oxidation. H2S removal occurs in the anodic section of the conductive concrete surface of the biofilm layer, the EPB activity releases electrons accompanied by the H2S oxidation of the organic matter. Subsequently, the electrons transfer to the electron acceptors through the electronic pathway inside the conductive concrete. Finally, at the liquid–air interface, oxygen, as an electron acceptor, reacts to produce water.Therefore, in this study, the work plan assumed the oxidation of sulfide by electron-releasing bacteria, as shown in 2S reduction was assessed. The experiments involving the inoculation of EPB were conducted, and the results were compared to investigate the efficiency of the conductive concrete.The aforementioned methods for testing the adsorption capacity of the different conductive materials were examined, and the effect of the H-3 and surface area of 1.9 m2/g). Its content was approximately 50 wt.%  (S50), with a water-to-powder ratio of 42%.San-earth M5C, commercially manufactured by Sankosha Co., Ltd., Tokyo, Japan (abbreviated as S), contained amorphous carbon produced from oil refining as a conductive component, with a maximum size of 0.3 mm (a specific gravity of approximately 1.285 g/cm-3 and surface area of 50–68 m2/g). Its contents were approximately 5 wt.% D5 and 10 wt.% D10, with water-to-powder ratios of 50% D5 and 62% D10.Denka Black (trade name of Denka Acetylene Black) was manufactured by Denka Co., Ltd., Tokyo, Japan (abbreviated as D), with a mean size of 35 nm (a specific gravity of approximately 0.04 g/cm-2/g). Its contents were approximately 5 wt.% M5, 25 wt.% M25, and 50 wt.% M50, with water-to-powder ratios of 38% M25 and 40% M50.Magnetite MTB-30 (trade name Magnetite) was manufactured by Morishita Bengara Kogyo Co., Ltd., Iga City, Japan (abbreviated as M), with a mean size of 0.5 µm (surface area of 13.3 mAll experiments were performed at room temperature (24 °C ± 0.1) using distilled water . The reagents used were of special grade obtained from Kishida Chemical Co., Ltd., Nacalai Tesque Co., Ltd., Osaka, Japan and FUJIFILM Wako Chemicals Industries, Ltd., Tokyo, Japan. The materials used as conductive concrete  and thei3 and a specific surface area of 0.3350 m2/g. Subsequently, all concrete samples without aggregates were cured and treated with an alum-based scouring removal agent.Ordinary Portland cement (OPC), manufactured by Sumitomo Osaka Cement Co., Ltd., Tokyo, Japan, was used as the normal concrete. This OPC had a specific gravity of 3.15 g/cmThe geometry of the cup-shaped specimens prepared using OPC, San-earth, and the new conductive concretes (Denka Black and Magnetite MTB-30) is shown in The electrical resistivities of the new conductive concrete materials were measured using a chemical impedance analyzer (model: IM3590) manufactured by Hioki Co., Ltd., Nagano, Japan, based on the widely used four-electrode method . These specimens were cured in water for 27 days, considering that the actual conduits are wet. Because concrete contains several electrolytes, the electrical resistivity changes with the application time. The electrical resistivities reported in this study were the values after 5 min, which were confirmed by the preliminary experiments that became stable, even in the low-frequency region, where it takes a longer time to converge to a constant value. The applied voltage and power frequency during the measurements were set to 0.3 V and 50 Hz, respectively. 2/L by nitrogen bubbling, were prepared for each conductive material, and Na2S.9H2O was added to reach a concentration of 20.5 mg S/L. The pH was maintained in the range of 7.0 ± 0.1. The adsorption apparatus was immediately sealed with a butyl rubber plug and then shaken. Samples were collected after a predetermined period to measure the sulfide ion concentration over time, considering that the sulfide oxidation during the sample preparation was negligible. All experiments were performed in triplicates. Sulfide was quantified by colorimeter, using the reagents to form methylene blue, according to the US EPA method (376.2).To confirm that the concrete materials do not contribute significantly to the effect of the sulfide reduction, San-earth (S50), Denka Black (D10), and magnetite (M50) tests were performed to determine the adsorption capacity. Three vials containing 100 mL of distilled water with a dissolved oxygen concentration of less than 0.1 mg OMorganella morganii and Proteus alimentorum were identified from the excess sludge, and two species, Proteus mirabilis and Shigella sonnei were identified from the digested sludge with a homology of more than 99.7%. These are typical intestinal bacteria, while those other than P. alimentorum are EPBs [P. alimentorum, this belongs to the Proteus genus (including P. mirabilis) and is also an EPB [The excess and digested sludge collected from the Ube City Wastewater Treatment Plant were isolated and cultivated in Luria–Bertani broth  at 30 °C. DNA was extracted using a Mora-Extract kit , according to the instructions of the manufacturer. A polymerase chain reaction was performed with the touchdown method using primers GC-341f and 518r for the amplification of the 200 bp 16S rDNA, which were analyzed using a DNA sequencer Ion S5  ,27. The are EPBs ,29,30. Ro an EPB ,31,32. 2S reduction. Each specimen was filled with 0.14 L of the digested sludge—suspended solids (SSs) concentration of 17,160 mg/L and volatile suspended solids (VSSs) concentration of 12,800 mg/L—thoroughly mixed with 1.12 L of synthetic wastewater.Two samples of OPC and San-earth were prepared to assess the contribution of EPB in the H4Cl, 2 mM K2HPO4, 2 NaHCO3, 0.02 yeast extract, 0.7 (NH4)2HPO4, 0.75 KCl, 0.42 FeCl3, 6H2O, 0.81 MgCl2, 6H2O, 0.25 MgSO4, 7H2O, 0.15 CaCl2, 6H2O, and 0.018 CoCl2, 6H2O [The synthetic wastewater containing the following compositions was prepared, as described by Zhou (2006)—(g/L distilled water): 2 glucose, 0.85 NHl2, 6H2O . M. morganii, P. alimentorum, P. mirabilis, and S. sonnei were added, each at approximately 108 CFU/mL. The experiment was started with the stabilized mixture, and the performance of the sulfide reduction was evaluated, based on the measurements of pH, sulfate ions, and sulfide concentrations over time. The pH and dissolved oxygen were measured using a pH meter (D-72) and DO meter (OM-71-2), respectively . Magnesium sulfate and glucose were added on days 5, 10, and 15.Other experiments were similarly set up with OPC and San-earth specimens. Microbial suspensions of The sulfate concentration in the water samples was measured using the barium sulfate turbidimetric method, according to the US EPA method (375.4) after filtration through a 0.45-µm membrane filter.The subjects of the different conductive concretes were asked to pay close attention, to evaluate the effect of the sulfide reduction over a long-term period. The specimens were used and filled with 0.14 L of the sludge mixture (a volume ratio of 1:1), comprising the excess (SS concentration of 6080 mg/L and VSS concentration of 5210 mg/L) and digested sludge , thoroughly mixed with 1.12 L of artificial wastewater (as described above). The experiment was started with the stabilized mixture, and the performance of the sulfide reduction was evaluated, based on the measurements of pH, sulfate ions, and sulfide concentrations over time. Once the results confirmed that sulfate was nearly completely consumed by SRB, a substrate of glucose (100 mg/L) and magnesium sulfate (33 mg S/L) was instantaneously added.The results obtained from the preliminary measurements of the electrical resistivity of various conductive concretes are presented in Denka Black improved the concrete conductivity more effectively than magnetite and San-earth. M50 had the lowest electricity resistivity, which is approximately the same as that of D10 (only 10% weight content of Denka Black). M50 and S50 had the same conductive substance content, and the resistivity of San-earth was higher than that of magnetite. There was a significant difference between the conductivity effect of the new conductive materials used in this study and that of the commercially conductive concrete of San-earth.2S adsorption experiment. The equilibrium was achieved after approximately 8 h.In the sulfide adsorption experiments, the most conductive materials, Denka Black (D10), San-earth (S50), and magnetite (M50), were chosen for the H2S adsorption, followed by San-earth and Magnetite (M50), which were considered the best adsorption materials. 2S, specimens of OPC and San-earth, with and without the EPB inoculation, were used to evaluate the pH, and sulfate, and sulfide concentrations for 20 days. To assess the role of the EPB activity in suppressing the efficiency of the HAs shown in 2S reduction (69%), whereas OPC with the inoculation and Sun-earth without the inoculation had percentages of 41% and 37%, respectively.To evaluate this effect quantitatively and more intuitively, the average sulfide concentration over the 20-day experimental period was calculated, and the reduction percentages of sulfide in the EPB strains inoculated with OPC and San-earth with and without the inoculation of EPB were compared, as shown in 2S in the specimen material, especially the conductive concrete. 2S inhibition. In this experiment, traditional concrete (OPC), commercial conductive concrete , and a highly conductive material (D10) were considered, in association with the EPB inoculation, to assess the advanced capacity of the H2S inhibition.The results indicated that concrete with a high density of conductive substances and EPB communities significantly affects the H2S, and a representative example is shown. The results obtained from monitoring the pH, sulfate, and sulfide concentrations for 134 days are presented in The reduction percentage of the sulfides relative to OPC, calculated from the average sulfide concentration after 134 days, is shown in 2S reduction. When the weight content of the conductive substances of Denka Black, magnetite, D10, M25, and M50 reached a high percentage of the H2S inhibition . The reduction rate for San-earth (S50) was more than 40%.The column chart shows a few characteristics of concrete. D5 and M5 did not exhibit a H2S by electricity-generating bacterial communities in effluent wastewater. Previous studies used a temperature of approximately 24–30 °C, a hydraulic retention time, and pH, as those used in this experiment, which were proposed to be appropriate for activating the MFCs [2S at the root of the conductive concrete. For the EPB-inoculated specimens, the OPC-inoculated specimens with a high resistivity resulted in a reduction in H2S , suggesting that the adsorption of a material does not contribute to the main mechanism for eliminating H2S, even though its capacity is reduced for the sulfide reduction. Previous findings failed to provide a clear explanation of the adsorption capacity and biological oxidation, particularly regarding the Hhibition . Moreoveeduction  is conceeduction : M50 > D2S. A linear correlation  was observed . Therefore, on using conductive concrete in sewer systems, sulfide ions may often exist at lower levels and pose a lower risk of H2S-related pipe damage. Although, these findings should be scrutinized, the inoculation of the EPB communities significantly accelerated the sulfide oxidation when highly conductive concrete was used. Further studies on this topic are therefore needed to select a conductive material that is less expensive and more effective in reducing sulfides. Furthermore, the transfer electrons via the electronic pathway inside the conductive material to oxygen as electron acceptors at the water–air interface, is crucial. Additionally, the convexity or concavity of the surface of the material must be considered as a factor in decreasing the sulfide reduction.Conductive concrete did not reduce sulfides when the conductivity was less than 0.12 (1/(Ω-m)), but almost all materials with higher conductivities revealed an evident deep reduction of Hrelation  was obta2S suppression was found, this study partially substantiated that the inoculation with EPB enables the biological oxidation to reduce the sulfide generation significantly. Further studies using the same experimental setup are needed, including the measurement of the compressive strength of the material, estimation of the manufacturing cost, trials to use less expensive conductive materials with higher sulfide reduction effects, based on the mechanism determined in this study, or a long-term demonstration study using real sewage water.The findings of this study provide a better understanding of the mechanism of the sulfide reduction by conductive concrete in sewage pipes. The current investigation determined a highly conductive concrete that showed a higher sulfide reduction than that achieved with the commercially manufactured conductive concrete. Specifically, the results for the conductive materials using Denka Black of 10 wt.% (D10) and magnetite of 50 wt.% (M50) helped clarify the role of highly conductive concrete, in comparison with the San-earth (S50) sample. Although a lower contribution of the adsorption process from the conductive materials to the effect of the H


Staphylococcus aureus is a prevalent etiological agent of health care associated and community acquired infections. Antibiotic abuse resulted in developing multidrug resistance in S. aureus that complicates treatment of infections. Targeting bacterial virulence using FDA approved medication offers an alternative to the antibiotics with no stress on bacterial viability. Using nanomaterials as anti-virulence agent against S. aureus virulence factors is a valuable approach. This study aims to investigate the impact of metformin (MET), metformin nano (MET-Nano), silver metformin nano structure (Ag-MET-Ns) and silver nanoparticles (AgNPs) on S. aureus virulence and pathogenicity. The in vitro results showed a higher inhibitory activity against S. aureus virulence factors with both MET-Nano and Ag-MET-Ns treatment. However, genotypically, it was found that except for agrA and icaR genes that are upregulated, the tested agents significantly downregulated the expression of crtM, sigB, sarA and fnbA genes, with Ag-MET-Ns being the most efficient one. MET-Nano exhibited the highest protection against S. aureus infection in mice. These data indicate the promising anti-virulence activity of nanoformulations especially Ag-MET-Ns against multidrug resistant S. aureus by inhibiting quorum sensing signaling system. A new formation of silver metformin nanostructure.S. aureus virulence factors.The in vitro inhibition of Nano structure form improves the activity of anti-virulence agents. S. aureus is a common causative agent of healthcare associated infections as well as community acquired infections, including soft-tissue, cutaneous infections and severe systemic infections , secreted enzymes , secreted toxins , biofilm formation and staphyloxanthin production , staphylococcal accessory regulator (sarA) and accessory gene regulator (agr). QS in S. aureus is regulated by agr operon. It is responsible for upregulation of the genes encoding superantigens, cytotoxins, and secreted enzymes. SigB gene is involved in induction of many stress genes and partially in expression of SarA and production of staphyloxanthin  is the fundamental regulator of bacterial virulence. Several regulatory loci regulate the development of crtM gene, catalyzes the first step in staphyloxanthin biosynthesis . The synthesis of PIA requires four gene products. These products are encoded in the icaADBC operon that is negatively regulated by icaR gene  enzyme, encoded by One of the therapeutic trends required to counteract multidrug resistant (MDR) infections caused by bacteria is the use of nanoparticles that have distinct physical and chemical characteristics in comparison with their bulk matter , tryptone soya agar (TSA), tryptone soya broth (TSB), Mueller Hinton agar (MHA) and Mueller Hinton broth (MHB) were the products of Oxoid . Other chemicals were of pharmaceutical grade. Metformin (MET) and silver were purchased commercially from Sigma Chemical Company, St. Louis, Mo, USA.S. aureus ATCC 6538, in addition to six clinical MDR isolates of S. aureus  were used. The standard strain was kindly gifted by the stock culture collection of Microbiology and Immunology Department, Faculty of pharmacy, Al Mansoura University, while clinical isolates were refreshed from the stock culture collection of Microbiology and Immunology Department, Faculty of pharmacy, Zagazig University. These six isolates were selected based on higher production of virulence factors among 20 clinical isolates screened. They were isolated from patients suffering from burn and wound infections in addition to blood infections and pneumonia; the sources are blood (SA2), burn swab (SA8 and SA9), surgical wound swab (SA12 and SA14) and endotracheal aspirate (SA17).In this study, To maintain the isolates, cultures were maintained in MHB with 10–15% glycerol added after growth. The cultures were kept at −80 °C.The formulations of metformin nano (MET-Nano), silver metformin nanostructure (Ag-MET-Ns) and silver nanoparticles (AgNPs) were prepared as follows:Silver nanoparticles were synthesized by mixing of silver nitrate (1 mM) solution with PVP (50 mg/mL) 1:1 v/v and maintained under stirring until a homogeneous solution was obtained followed by irradiation at 40 kGy gamma ray. Metformin nano was prepared by addition of tween 80 (10%) and isopropyl alcohol (0.02%) dropwise into aqueous metformin (100 mg/mL) under continuous stirring using homogenizer at 10000 rpm for 30 min. The solution was then sonicated using ultrasonic sonicator for 1 h. Silver metformin nanostructure was prepared by dropwise addition of silver nanoparticles colloid  into a mixture of aqueous metformin (100 mg/mL), tween 80 (10%) and isopropyl alcohol (0.02%) under continuous stirring using homogenizer at 10,000 rpm for 30 min. The solution was then sonicated using ultrasonic sonicator for 1 h.For validation of nanoformulation, the size and stability of the provided Ag-MET-Ns were characterized by using size distribution and zeta potential measurements. The Fourier transforms infrared spectroscopy (FT-IR) was used to estimate the Ag-MET-Ns function moiety  with sterile saline and then were 1:100 diluted to reach 106 CFU/mL with MHB. Aliquots of 50 µL of serially diluted tested agents were added to the wells of microtiter plate. The bacterial suspension was delivered in aliquots of 50 µL to the wells of microtiter plate. Following overnight incubation at 37 °C, the lowest concentrations of the tested agents that inhibit the bacterial visible growth were calculated and considered as the MIC values.The minimum inhibitory concentrations (MICs) of MET, MET-Nano , Ag-MET-Ns (100 mg/mL-50 ppm) and AgNPs (50 ppm) against the tested isolates were assessed using the broth micro-dilution method using 96-well microtiter plate according to the Clinical and Laboratory Standards Institute (CLSI) guidelines . The experiment was done in duplicate. The biofilm forming capacity was assessed according to the criteria of Stepanović et al.  were added for 15 min to stain the biofilms, washed three times with water and dried. The bound dye was solubilized with 150 µL/well of 33% glacial acetic acid. The ODć et al. .The biofilm inhibitory activities of the tested agents against the tested isolates were performed in the presence of 1/10 MIC of them using the same procdure. The percentage (%) of biofilm inhibition was estimated using from the following formula;OD 570 nm—Treated OD 570 nm)/Control OD 570 nm] × 100.% of biofilm inhibition = [. The experiment was performed in duplicate.The inhibitory activities of the tested agents against staphyloxanthin pigment were assessed  by qRT-PCR. Primers used in this study are listed in Table S. aureus isolate was extracted and purified using TRIzol Reagent  following the manufacturer protocol. Reverse trancription using QuantiTect Reverse Transcription Kit was performed for cDNA synthesis. Afterthat, the cDNA was amplified using Thermo Scientific Maximas SYBR Green/Fluorescein qPCR Master Mix. The average threshold cycle (CT) values were normalized to the housekeeping gene (16 s rRNA) in S. aureus. The relative gene expression of treated isolate was compared to that in the untreated ones according to the 2−∆∆Ct method , Egypt . Bacterial load in mice tissues was determined as previously described with some modifications  with equal weights (15–20 g) were used. Mice were devided into seven random groups (5 mice/group). In group 1, mice were intraperitoneally injected with 100 µL of untreated bacteria in sterile PBS. In group 2, mice were injected with 100 µL of MET-treated bacteria, group 3 was injected with 100 µL of MET-Nano-treated bacteria, while group 4 was injected with 100 µL of Ag-MET-Ns-treated bacteria and group 5 was injected with 100 µL of AgNPs-treated bacteria. Two negative control groups are also included; group 6, mice were injected with 100 µL of sterile PBS and group 7, mice were left uninoculated. At room temperature, all groups received normal feeding and aeration. Mice were euthanized after 24 h, livers and kidneys were aseptically isolated, homogenized and plated for viable count that expressed as colony forming unit per gram (CFU/g).Using mice as an infection model, the effect of the tested agents on P < 0.05 for signifcance.The effect of the tested agents on virulence factors expression was analyzed by GraphPad Prism 8 software using One Way ANOVA followed by Dunnett’s Multiple Comparison tests at The size distribution analysis of MET-Nano and Ag-MET-Ns was performed using DLS Zeta Sizer Technique. As shown in Fig. −1, 1660 cm−1 and 620 cm−1. The broad peak at 3330 cm−1 can be specified to N–H stretching, while the band at 1660 cm−1 is assigned to N absorption. The band found at 617 cm−1 can be specified to C-H out of plane bending and C-N–C deformation. After the synthesis of Ag-MET-Ns, the decrease in the intensity of peaks may be due to physical binding of AgNPs to NH groups of MET that recommends their role in the stabilization of Ag-MET-Ns  and Metformin nano (MET-Nano) were similar. The MIC was greatly decreased by the combination of MET and AgNPs (Ag-MET-Ns) than either MET, MET-Nano or AgNPs alone. Considering the increased sensitivity to MET, the MICs were decreased by 2–32 folds, while for MET-Nano (2–16) folds and in case of AgNPs, (4–32) folds  as shown in Fig. The activity of the tested agents against S. aureus was estimated spectrophotometrically. The tested agents showed significant inhibition of staphyloxanthin pigment production compared to the controls at (P < 0.05) as shown in Fig. The ability of the tested agents to inhibit staphyloxanthin pigment production of S. aureus ATCC 6538 virulence genes. The 2−∆∆Ct method was used to analyze the obtained results. The tested agents significantly downregulated the expression of QS regulatory genes; crtM, sigB, sarA and fnbA, while agrA and icaR were upregulated when treated with the tested agents in comparison to the untreated controls  each, whereas the highest inhibitory activity found with Ag-MET-Ns (60%). With regards to sigB gene expression, the lowest percentage inhibition found with MET (25%), followed by MET-Nano and AgNPs (< 40%) each, whereas Ag-MET-Ns showed the highest inhibitory activity (65.75%). In addition, Ag-MET-Ns showed the highest inhibition of fnbA (55.17%), while against sarA, the inhibitory activities of MET-Nano and AgNPs were more or less similar , with the highest reduction observed with Ag-MET-Ns (55.15%), however, lower inhibition of 33.92%, 39.28% and 41.13% was found with MET, AgNPs and MET-Nano, respectively. On the other hand, the expression level of agrA was significantly increased; up to 69.4% with AgNPs, 91.7% with MET, with maximum upregulation  (155.6%) with Ag-MET-Ns, while no significant increase was observed with MET-Nano. Similarly, icaR expression was significantly increased in the presence of sub-MICs of the tested agents; 86.4% with AgNPs, 135.8% with MET-Nano, while Ag-MET-Ns achieved the highest percentage (148.3%). However, no significant increase was found after treatment with MET.The qRT-PCR was performed to investigate the impact of the tested agents on the expression of ols Fig. . The expP < 0.05). The results were expressed as log CFU/g of organ  that are liberated inside neutrophils and macrophages, and thus deactivate it, giving S. aureus the merit of evading innate immunity -based compounds is on the rise because of silver broad spectrum of action and little likelihood of developing bacterial resistance in comparison to current antibiotic regimens  to ensure that the inhibitory effect of the tested agents is due to inhibition of bacterial virulence factors instead of affecting their growth.Metformin is a widely prescribed oral hypoglycemic over the world  exhibited higher synergistic activity than that of MET-Nano or AgNPs alone , cspA gene that encode CspA cold shock protein and hfq gene encoding Hfq protein that acts as a multifunctional regulator in bacteria . These results suggest further studies to investigate the mechanism of action of such formulations. The variation in the results may be attributed to the fact that staphyloxanthin can reduce the fluidity of cell membrane and stabilize its structure, modifying its chemical composition and its function  nanoparticles (AgWPA-NPs). However, Singh et al. (+ treated biofilms in spite of the variation in gene expression as shown by fold change values. The variation in the effect of tested agents on different isolates may be also due to the difference in the sources of the isolates. It was previously reported that there is variation in virulence genes expression in strains of Pseudomonas aeruginosa isolated from different sources (Sameet et al. In this study, the effect of the tested agents on the downregulation of QS regulating genes nes Fig. . Among ag et al.  reportedh et al.  found noS. aureus pathogenesis were determined in vivo, the highest protection was found with mice group injected with sub-MIC of MET-Nano; being the most effective among the tested inhibitors. In addition, Metformin nano showed much lower accumulation than the bulk metformin or metal nanoparticles, therefore reducing cytotoxicity occurring after exposure. Similarly, Li et al. (S. aureus is a leading cause of life-threatening MDR infections worldwide. With shortage of new antibiotic development, novel approaches are required such as repurposing the FDA approved drugs against bacterial QS system. The oral hypoglycemic agent metformin exhibited better anti-QS activity against MDR S. aureus when it was nanoformulated. Its antibacterial and anti-QS activities were augmented when combined with silver nanoemulsion.The inhibitory activities of the tested inhibitors against i et al.  showed ti et al. , it was i et al.  observed


The development of substance use disorders involves long-lasting adaptations in specific brain areas that result in an elevated risk of relapse. Some of these adaptations are regulated by the mTOR network, a signalling system that integrates extracellular and intracellular stimuli and modulates several processes related to plasticity. While the role of the mTOR network in cocaine- and alcohol-related disorders is well established, little is known about its participation in opiate use disorders.To use a heroin self-administration and a withdrawal protocol that induce incubation of heroin-seeking in male rats and study the associated effects on the expression of several genes related to the mTOR system and, in the specific case of Rictor, its respective translated protein and phosphorylation.Igf1r, Igf2r, Akt2 and Gsk3a in the basolateral complex of the amygdala, which was not as evident at 30 days of withdrawal. We also found an increase in the expression of Rictor (a protein of the mTOR complex 2) after heroin self-administration compared to the saline group, which was occluded at the 30-day withdrawal period. The activation levels of Rictor, measured by the phosphorylation rate, were also reduced after heroin self-administration, an effect that seemed more apparent in the protracted withdrawal group.We found that heroin self-administration elicited an increase in the expression of the genes These results suggest that heroin self-administration under extended access conditions modifies the expression profile of activators and components of the mTOR complexes and show a putative irresponsive mTOR complex 2 after withdrawal from heroin use. The development of compulsive drug use and the elevated risk of relapse even after protracted abstinence periods are two cardinal aspects of substance use disorders that involve synaptic plasticity processes , six genes coding upstream second messengers of the network , three coding components mTOR complexes  and three genes coding for downstream mediators and effectors . Given that we found an increase in the expression of Rictor, a regulator protein specific to mTORC2, and that the increased activity of this protein could contribute to explaining some of the results obtained, we decided to analyse the total levels of this protein and its phosphorylation at the threonine 1135 residue, an essential regulator of mTORC2 recruitment.In this study, we aimed to assess the possible relationship between the mTOR network and opioid consumption and risk for relapse. For this purpose, we submitted rats to a heroin self-administration protocol under extended access conditions, a paradigm that induces escalation of drug intake and increased motivation for consumption , between 300 and 320 g of weight at the beginning of the experiments. The animals were kept in the vivarium in a light–dark cycle (on at 08:00 am), at a constant temperature (20 ± 2 °C) and relative humidity (50% ± 10%), with ad libitum access to water and food . Since their arrival, the animals were housed in groups of three until catheterisation surgery, 1 week before the start of the self-administration sessions. Subsequently, they were single-housed to prevent potential damage to the catheters. All the animals were maintained and handled according to European Union guidelines for the care of laboratory animals , and the Ethical Committee of UNED approved all the experimental procedures. With the aim of complying with the reduction principle of the 3Rs, these animals belong to a subset of the rats used in our previous experiments , vehicle withdrawal 1 day , heroin withdrawal 30 days , vehicle withdrawal 30 days , heroin withdrawal 1 day seeking test  and heroin withdrawal seeking test . The rats of the HW1, VhW1, HW30 and Vh30 groups were only used for tissue harvest and molecular analysis and did not undergo extinction tests, while the HTest1 and HTest30 groups were only used for the behavioural tests of incubation of heroin-seeking.Animals were initially preassigned to vehicle or heroin self-administration groups. After the self-administration phase, the following groups were matched for the consumption of either heroin or saline: heroin withdrawal 1 day , and a polyvinyl chloride catheter  was inserted into the right jugular vein of the animal approximately at the level of the atrium and secured there with surgical thread. The catheter was fixed subcutaneously around the neck, exiting the skin at the midscapular region. A pedestal of dental cement was then mounted on the skull of the rat to attach the tethering system. After surgery, the rats were allowed to recover for 7 days and an NSAID was added to the drinking water (meloxicam—Metacam™: 15 drops of a 1.5 g/ml solution per 500 ml of water). Until the end of the self-administration procedure, the catheters were flushed daily with a sterile saline solution containing sodium heparin (100 IU/ml) and gentamicin (1 mg/ml) to maintain catheter patency and to prevent infections.Twelve operant conditioning chambers  (Coulborne Instruments), each equipped with a microliter injection pump, were used for the heroin self-administration and seeking tests. A catheter was connected to the rat and held in place with a spring-tether system, and a rotating swivel, which allowed the animals to move freely inside the chamber. Two levers placed 14 cm apart were available throughout all the sessions, one of them inactive.A week after recovering from surgery, the rats underwent 10 daily sessions of either heroin or vehicle self-administration. During the light phase of the light cycle, for 6 h rats were allowed daily access to heroin  or its vehicle alone under a fixed-ratio 1 reinforced schedule. The house light was off during the sessions, although we allowed some environmental light to respect the light/dark cycle of the animals. During these sessions, one active lever press resulted in a heroin infusion (100 μl delivered over 5 s) and a cue light was switched on for 10 s. Each active lever press was followed by a 40-s time-out during which the responses had no effects but were still registered. In the first two self-administration sessions, two sucrose pellets were placed on the active lever to facilitate the acquisition of self-administration behaviour.The rats of the HTest1 and HTest30 groups underwent seeking tests 1 day or 1 month after the last self-administration session. These tests were performed under the same conditions as the self-administration sessions, but the active lever presses were not followed by an infusion, and the duration of the sessions was 3 h. During the withdrawal period, the animals were still handled daily but their catheters were no longer flushed with the gentamicin/heparin solution.Rats of the HW1, VhW1, HW30 and Vh30 groups were weighed and euthanised by decapitation 1 day or 1 month after the last self-administration session, between 11:00 and 13:00 a.m. The rat’s brain was extracted and submerged in isopentane chilled on dry ice for ten seconds and stored at − 70 °C.  and tempered at − 20 °C in a cryostat chamber . After 1 h, slices about 300 μm thick were collected and dissected with sterile equipment. The BCA dissection was performed following Paxinos and Watson, Samples were weighed and homogenised with a pellet pestle  in HEPES buffer  prepared in diethylpyrocarbonate (DEPC)-treated water, and containing sucrose , protease inhibitors (Roche complete EDTA-free 11.873.580.001) and phosphatase inhibitors (Roche PhosSTOP 04.906.837.001) and sodium butyrate . The homogenates were kept on ice for 10 min and then centrifuged for 10 min at 1000 g at 4 °C. The supernatant was separated into three different tubes: an aliquot equivalent to 3–4 mg of tissue (≤ 80 μL) in a tube with 800 μL of QIAzol  for RNA isolation; another aliquot in a tube with loading buffer for western blotting; and the rest into an empty tube for protein quantification and other experiments. All the aliquots were stored at − 70 °C.Gapdh as a reference gene and the reaction efficiencies were obtained using LinRegPCR software  and treatment  and withdrawal  as between-subject factors.t-test to compare the means of the active lever presses during the seeking tests of the HTest1 and HTest30 groups. We also carried out an ANCOVA with inactive lever presses as a covariate in order to control the influence of this variable.For the analysis of the incubation of drug-seeking, we performed a For the analysis of the biochemical variables, we used a two-way ANOVA with two factors: treatment (Two levels: heroin and vehicle) and withdrawal (two levels: 1 day and 30 days). In the case of a significant interaction, a simple effect analysis with a Bonferroni correction was performed.10, square root or reciprocal transformations. If the assumptions were still violated, a Kruskal–Wallis non-parametric test was performed instead of ANOVAs.Prior to these tests, we checked for normality and homoscedasticity and applied logThe statistical analyses were performed using SPSS 24 (IBM) and InVivoStat (Mockett Media). The graphs were designed using PRISM 6 (Graphpad software Inc.). The diagrams of the signalling pathways were created with BioRender.com.F9,374 = 4.48, p < 0.0001), indicating that the behaviour changed throughout the sessions. We also found an effect of the treatment factor , and a session × treatment interaction   Fig. . The posp = 0.028, d = 1.335), even when controlling the inactive lever presses as a covariate   displayed more active lever presses than the rats in the short withdrawal group (HTest1) , Gsk3a , Igf1r  and Igf2r  . The simple effects analysis showed that the animals had higher levels of Rictor expression after heroin self-administration compared to their controls  and that there was an increase after the withdrawal in the expression of Rictor in the BLA of the rats that self-administered vehicle , while the rats that self-administered heroin had already elevated levels before withdrawal  . It must be noted that even if this effect seems to be specific to the HW30 group, the treatment × withdrawal interaction was not significant .Although we did not find significant changes in the levels of Rictor or phospho-Rictor (thr1135) corrected for the total protein loaded, there was a significant effect of the Treatment in the phosphor-Rictor (th1135)/Rictor ratio  . This is interesting because, in a previous study, we found a similar effect in rats that had self-administered morphine, and this effect persisted after 15 extinction sessions . Other studies have shown that the peak of “incubated” heroin-seeking in withdrawn rats occurs at around 6 days (Shalev et al.


In this paper, the strength characteristics and erosion resistance of solid waste incineration (MSWI) powder were studied. Firstly, the optimum process for the preparation of regenerated powder from MSWI bottom slag by ball milling was determined as follows: rotational speed 350 r/min, time 45 min. The strength activity index of regenerated powder reached the maximum when the substitute content of powder was 30%. Secondly, the semi-erosion method was used to study the strength variation rule of mortar with different content of MSWI powder in semi-immersion of salt solution. It was found that the higher the content of MSWI powder, the greater the anti-erosion coefficient of mortar specimen. Finally, the capillary rise test, crystallization test and capillary pore water absorption test were used to study the total porosity, coarse capillary-pore porosity and fine-capillary pore porosity of concrete containing MSWI powder. The results showed that, with the increase in MSWI powder content, the above pore structure properties were improved. The results revealed the transport and crystallization process of salt solution in concrete mixed with MSWI powder and the mechanism of corrosion resistance. With the continuous development of construction engineering, concrete structure is widely used in construction, bridge, road and other structural engineering. The durability mechanism of concrete structure has become the focus of global attention, which is the most critical index affecting construction quality. In practical engineering, the durability of concrete materials is mostly damaged by sulfate and chloride, which is also the most complicated and destructive cause of concrete structure damage ,2,3,4,5.2SO4-Thenardite, Na2SO4·10H2O-Mirabilite, and Na2SO4·7H2O-Sodium sulfite heptahydrate. Among them, Na2SO4·10H2O was difficult to maintain at a stable state and was easily decomposed into Na2SO4 and Na2SO4·7H2O. The changes of temperature and humidity also had a significant influence on the chemical composition of sodium sulfate crystals. The sulfate resistance of concrete was affected by its shape and appearance, permeability resistance and compactness [Sodium sulfate was the most widely distributed sulfate solution in nature and had the most serious erosion to concrete ,7. Accorpactness ,18,19,20pactness ,22,23,24pactness ,26,27,282 so as to improve the structure of concrete transition zone and enhance the sulfate erosion resistance of concrete. Fly ash can also increase the resistance of HPC to sulfate corrosion [2 generated in the secondary hydration reaction of concrete; thus, the sulfate resistance of concrete can be improved. However, as a new type of admixture, there is little research on urban-life incinerations for bottom slag with respect to the durability of concrete.In view of the study on the durability of concrete by mineral admixtures, Qin Lixiang believed that using more fly ash instead of cement can reduce the pore structure of cement concrete and the content of Ca(OH)orrosion . When thorrosion , but theorrosion . The addorrosion , and the42−/Cl− solution erosion performance of mortar samples containing MSWI was studied to discuss the variation of anti-corrosion coefficient with the amount of fine powder. The crystallization transport process of salt solution in bottom slag recycled concrete was also studied. By studying the change of porosity of recycled concrete containing MSWI bottom slag and the correlation between capillary pore gaps and different factors, the mechanism of the salt crystallization resistance of recycled concrete containing MSWI bottom slag was revealed.In this paper, the anti-SOThe MSWI residue used in this experiment was obtained from a waste incineration power plant in Huai’an city, Jiangsu Province. The samples randomly selected on site were generally gray and black, and after drying, they were gray and white with a slight odor, as shown in The ordinary Portland cement of strength grade 42.5 was used, which was in line with the general Portland cement (GB175-2009) standard provisions. The adoption of standard sand was in line with China’s new standard ISO. The industrial grade anhydrous sodium sulfate and anhydrous sodium chloride were >99.0% and 99.5%, respectively. The recycled concrete containing MSWI was tested using natural sand and gravel in accordance with JCJ 52-2006 standards, and polycarboxylic acid high-efficiency water-reducing agent was used as the water-reducing agent.In this experiment, the influence of ball mill rotation speeds and ball grinding time on MSWI residue regeneration was considered. Firstly, the grinding time was 30 min, and the bottom slag was ground at the rotation speed of 200 r/min, 250 r/min, 300 r/min, 350 r/min, 400 r/min, and 450 r/min to obtain the fine powder. The residue ratio was measured by a 80-mesh sieve, and the specific surface area of MSWI residue was measured by a laser particle size analyzer to find out the optimal speed of the ball mill under fixed grinding time. Under the optimum speed of ball mill, the influence of time factors on the regeneration efficiency of MSWI bottom slag was determined. The bottom slag was ground for 15 min, 30 min, 45 min and 60 min at the optimal speed, and the screening residual rate of micro-powder was determined using a 80-mesh sieve. The specific surface area of micro-powders was determined by a laser particle-size analyzer, and the optimal ball milling time was determined.The Dkz-6000 electric bending test machine and automatic constant pressure compression test machine are used for mortar strength tests. According to the method required in GB17671-1999 , the morThe erosion and damage of sodium sulfate crystals on mortar specimens containing MSWI were investigated in the laboratory. Sodium sulfate solution mainly entered cement-based materials through capillary action. In this experiment, the method of semi-immersion experiment was adopted, and the mortar specimen was formed by a triple mold of 40 mm × 40 mm × 160 mm. After standard curing for 28 days, the specimens were divided into two groups, which were first heated and dried in the oven. The first group was half-soaked in clean water, and the second group was half-soaked in 5% sodium sulfate solution see . The efftw is the mass change rate of the specimen when the age of erosion is t; tm is the mass of the specimen when the erosion age is t, unit/kg; m0 is the initial mass of the specimen, unit/kg.After the mortar specimen containing MSWI was corroded by sodium sulfate solution, the specimen expanded and its surface spalled, resulting in mass loss. The water on the surface of the specimen dried and then the water was poured on an electronic scale for quality measurements. The accuracy of electronic scale needed to reach 0.01 so as to accurately calculate the rate of mass change. The mass change rate of specimens is calculated by Formula (1):The influence of physical erosion of mortar specimen containing MSWI by sodium sulfate crystallization can be evaluated by calculating the corrosion resistance coefficient. The compressive and corrosion resistance coefficient referred to the ratio of the compressive strength of specimens with the same curing age and the same mixing ratio soaked in salt solution and water. The flexural and corrosion resistance coefficients referred to the ratio of flexural strength of specimens with the same curing age and the same mix soaked in salt solution and clean water, as described in Formulas (2) and (3).miK is the compressive corrosion resistance coefficient of the specimen at the i th erosion age; miR1 is the compressive strength of the specimen at the i th erosion age in salt solution, unit/MPa; miR2 is the ith erosion age of the specimen in clear water compressive strength, unit/MPa; niK is the flexural and corrosion resistance coefficient of the specimen at the i th erosion age; niR1 is the flexural and corrosion-resistant coefficient of the specimen in the salt solution at the i th erosion age, unit/MPa; niR2 is the compressive strength of the specimen at the i th erosion age in clean water, unit/MPa.C0 was taken from the mixture of sodium chloride and saturated Ca(OH)2. Cement-based materials and sodium chloride solution were sealed in a beaker and then placed in a curing chamber for one week.For chloride ion erosion tests of mortar containing MSWI, S1–S4 samples with different dosage of MSWI were prepared according to C1 (mol/L) was measured. Then, continue to add 50 mL (V4) of distilled water and a small amount of Ca(OH)2 solution into the beaker to make the solution a saturated Ca(OH)2 solution. The beaker was sealed in the curing chamber for three days, and the equilibrium solution was taken out from the beaker. The concentration of chloride ions in the equilibrium solution was C2 (mol/L), and the formula is shown in (4):C01 is the concentration of AgNO3, unit mol/L; V1 is the capacity of AgNO3 consumed by the first titration, unit mL; V2 is the capacity of AgNO3 consumed by the second titration, unit mL.After a week, the transparent liquid was removed from the beaker and its chloride ion concentration V0 volume is 100 mL; C0 is the concentration of NaCl solution saturated with Ca(OH)2; W1 is the binding amount of all chloride ions , in unit 10−3; gM is the total amount of gel material (cement and micro-powder), unit g; m is dry sample mass, unit g; m0 is the water requirement of cementing material (cement and powder) per unit mass, and the value is 0.25; W1 is the dimensionless ratio of cementitious material to the total amount of cementitious material and sand; α is the degree of hydration, α = M1/m0; W2 is the chemical binding amount of chlorine ion per unit mass of gel (cement and micro-powder), unit 10−3. W3 is the physical adsorption amount of chloride ion per unit mass of gel (cement and micro-powder), unit 10−3; V3 is the first equilibrium solution used for titration, unit mL.The calculation formulas for the binding amount of chloride ions are shown in (5), (6), (7) and (8):All concrete specimens used in this experiment were tested in accordance with the standard JGJ 55-2000 , and them1 measured by an electronic balance. Then, it was placed in the curing chamber at 90% relative humidity for 30 days. When water diffusions in concrete reache equilibrium state, the mass m2 of the same specimen was measured again. Under the condition of T = 105 °C, the specimen was dried to a constant weight and finally weighed m3 after cooling to calculate concrete porosity. The specific equations are shown in (9), (10) and (11):P1 is the coarse capillary porosity; P2 is the total porosity; P3 is the fine capillary porosity; M1 is the mass of saturated, unit kg; M2 is the mass of concrete specimen placed at 90% relative humidity for 30 d, unit kg; M3 is the mass of dry concrete specimen, unit kg; ρ1 is the density of concrete specimen, unit kg/m3; wρ is the density of water in kg/m3.The porosity of concrete can be obtained indirectly from the water loss rate of saturated concrete specimen. Concrete samples were made of 100 mm × 100 mm × 100 mm by the vibration molding method. After curing for 28 d and vacuum saturation, the water on the surface of the concrete samples was wiped with a dry cloth first. The mass of the samples was VS = L/T of osmotic crystallization rate is calculated, and the unit is cm/s. The experiment was carried out at room temperature, and the experimental device is shown in For the capillary rise experiment and capillary crystallization experiment of reclaimed concrete containing MSWI, 150 mm of side length concrete was first made according to the mix ratio. After 28 d curing in the curing room, a cylinder with a diameter of 100 mm and height of 150 mm was drilled on the concrete specimen with the core machine, and moisture was dried in the oven. The core body was half immersed in sodium sulfate solution, and the rising height of the surface of the core body of different specimens was measured. The remaining holes of concrete after core removal were closed. In the use of 5% sulfuric acid solution drops into the hole, crystallization from the surface of the concrete test block penetration time T and the concrete side wall thickness L were tested. Through the relation between the time T of crystallization penetrating out from the surface of concrete test block and the inner wall thickness L of concrete, the formula W at 10 time points in 24 h. The experimental device is shown in For capillary water absorption tests of reclaimed MSWI concrete, a concrete cube with a side length of 100 mm should be made. After curing for 28 d, it should be sealed with oxidized grease around it and placed into a drying box for drying. The test block was semi-immersed in a solution of sodium sulfate with a water surface height of 5 cm. It was taken out every once in a while and dried with a wet cloth. The weight of the test piece was immediately weighed. The experimental measurement time was the accumulated water absorption ΔAt a fixed time of 30 min and 45 min, the cumulative pass rate of 80 mesh corresponding to different speeds is shown in The specific surface area of MSWI powder at different rotational speeds is shown in 2/g, which obviously exceeded the specific surface area specification of conventional cement. The continuous increase in speed accelerates the wear of the machine and the consumption of electric energy; thus, 350 r/min was selected as the optimal speed.Based on the above experimental results and analysis, when the rotational speed was 350 r/min, the residue ratio of 80 mesh regenerated powder had reached a high level, and the specific surface area of the regenerated powder reached 7000–8000 cmThe compressive test results and strength activity indexes of different powder dosages are shown in The test results of 28 d flexural strength of mortar containing MSWI with different dosage are shown in The content of calcium oxide in MSWI powder was lower than that of cement, and there were few effective hydration products that can promote strength growth in the early stage. Therefore, the strength of mortar specimens containing MSWI was lower than that of pure mortar. On the other hand, MSWI powder was rich in silicon oxide and alumina, which can promote the pozzolanic reaction and effectively increase the later strength of cement-based materials. When the amount of MSWI powder was small, aluminum acid ions, sulfate ions and some unhydrated calcium oxide in cement-based materials were hydrated and regenerated into crystals, thus increasing the strength of mortar. However, the mass substitution of MSWI powder significantly reduced the content of calcium oxide in the paste, resulting in a reduction in crystals formed by aluminate ions as sulfate ions.2 in the mortar specimen dissolves, SO42− radical ions in the external solution also enter the interior of the specimen to carry out chemical reactions, thereby increasing the mass of the MSWI-containing mortar specimen [1 specimen was 12% higher than that of the S2 specimen when eroded for 180 d. The mass increase in the S1 specimen was 20% higher than that of the S3 specimen, and the mass increase in the S1 specimen was 27% higher than that of the S4 specimen.specimen . It can 42− ion erosion, SO42− ions entered the mortar structure and participated in the reaction, forming sodium sulfate crystals with filling and compacting effect, and the strength of the specimen increased at this time. However, as the erosion age further increased, the accumulation of sodium sulfate crystals caused the specimen to expand and form micro-cracks, which reduced the strength of the specimen. From the beginning of erosion to the age of 180 d, the compressive corrosion resistance coefficients of the four groups of specimens were S1 < S2 < S3 < S4, and the compressive corrosion resistance coefficients of S1, S2, S3 and S4 at 180 d were 0.92, 0.97, 0.98 and 1.02, respectively, indicating that MSWI powder as an active admixture can resist sulfate erosion in mortar.− ions did not erode the internal structure of green mortar significantly under semi-immersion conditions. No damage such as spalling and cracking was found on the surface of the MSWI-containing mortar specimens with different contents [contents .The research showed that the cement hydration products—calcium silicate hydrate (C-S-H) gel—not only had chemical adsorption to chloride ions but also have physical adsorption to chloride ions, and physical adsorption contributes greatly to the total adsorption amount . Since 2 in cement-based materials to form hydrated aluminate phase and other derivatives. The aluminate hydrate reacts with chloride ions to form Friede salts, so the cement-based material had a strong chemical combination with chloride ions. Due to the high specific surface area (7000–8000 cm2/g) of MSWI powder particles, more chloride ions can be adsorbed on the surface of MSWI particles so that the physical adsorption capacity of MSWI-containing mortar increases.The compressive strength test results of concrete specimens containing MSWI are shown in The pore structure and porosity were key factors affecting the strength of cement-based materials, which were also decisive factors for the resistance of cement-based materials to salt solutions. When the porosity was large and the pores were interconnected, the corrosion resistance of cement-based materials was poor. On the contrary, when the porosity was smaller, the concrete was more compact, and the erosion resistance of concrete can be better obtained. Therefore, the concrete containing MSWI had better corrosion resistance.With the increase in MSWI powder content, the compressive strength and flexural strength of mortar specimens at various ages showed a decreasing trend, and the reduction in flexural strength was larger than that of compressive strength. The micro-powder had little influence on the strength of recycled mortar in the early stage, but it had significant influences on the strength in the later stage. The strength activity index of regenerated powder was about 55% when the content of regenerated powder was 30%.With the passage of the sample’s half-soaking time in sodium sulfate solutions, the mass loss rate of mortar decreased gradually with the increase in MSWI content, while the corrosion resistance coefficient increased first and then decreased. Under the condition of constant w/c ratio, the salt crystal erosion resistance of mortar can be improved effectively with the addition of MSWI powder.The cement-based materials containing MSWI had a high ability to bind chloride ions. With the aging of curing, the performance of cement-based materials to bind chloride ions decreased. The total porosity, coarse capillary porosity and fine capillary porosity of recycled concrete decreased with increasing MSWI powder content.The amount of MSWI powder can affect the capillary height, absorption and crystallization rate of sulfate solution in concrete. The capillary rise height, osmotic crystallization rate and 5% sodium sulfate solution were linearly correlated with capillary porosity, but they were linearly independent of capillary porosity; thus, capillary porosity played a key role in capillary transport, migration and the crystallization of sulfate solution in recycled concrete.42−/Cl− erosion resistance of concrete.The MSWI powder had a certain strength activity, and it was feasible to replace part of the cement as a mineral admixture. It was not only beneficial to reduce the environmental problems caused by MSWI bottom slag, in line with the concept of green and sustainable development, but it also can make concrete more dense and improve the SOThe main conclusions of this paper are as follows:


Understanding the rate and composition of bacterial co-infection is important to determine antibiotic therapy in SARS-CoV-2 infection, but those vary according to healthcare settings and regional differences. We evaluated the rate of bacterial co-infection in hospitalized patients with COVID-19 in a single tertiary hospital in South Korea.Legionella pneumophilia PCR, and sputum multiplex PCR for Mycoplasma pneumoniae and Chlamydia pneumoniae. Characteristics and outcomes of patients were evaluated according to antibiotics exposure prior to hospitalization.In this retrospective study, all the adult patients with COVID-19 hospitalized between Feb 2020 and Dec 2021 were included. Bacterial co-infection rate was assessed by results of sputum cultures, blood cultures, pneumococcal urinary antigen, Legionella urinary antigen, sputum Of 367 adult patients, 300 (81.7%) patients having sputum culture results were included in the analysis. Of these, 127 (42.3%) had a history of antibiotic exposure within 1 month before hospitalization. The coinfection rate within 48 hours of hospitalization was confirmed in 8.3% (25/300): 6.4% (11/163) of patients without prior antibiotic exposure and 11% (14/127) of patients with prior antibiotic exposure. In the group without prior antibiotic exposure, pathogens responsible for community-onset infections were isolated, whereas nosocomial pathogens were predominantly isolated in the antibiotic-exposed group. Empirical antibiotics were used in 144 (66%) of 275 patients without positive results for microbiological tests. Empirical antibiotic use in patients without positive results for microbiological tests was not significantly associated with 30-day mortality or in-hospital mortality after adjusting covariates including age, sex, comorbidity, anti-inflammatory treatment, and COVID-19 severity.In this study with a high rate of microbiological testing, bacterial co-infection was not frequent, and the results varied depended on previous exposure to antibiotics. Given the rarity of bacterial co-infection and the lack of potential benefits of empirical antibiotic therapy, the antibiotic use in patients with COVID-19 should be restricted as an important target of antibiotic stewardship.All Authors: No reported disclosures.


Immunoglobulin (Ig)G4-related disease (IgG4-RD) with retroperitoneal fibrosis (RPF) is a rare, fibroinflammatory disease involving the soft tissues of the retroperitoneum. A 73-year-old man with IgG4-related RPF affecting the abdominal aorta and iliac arteries was treated with steroids and mycophenolate mofetil. The prevalence of the disease remains unknown because it is often misdiagnosed and can mimic many malignant, infectious, and inflammatory conditions. Autoimmune pancreatitis is a common presenting condition of IgG4-RD. Because As IgG4-RD is responsive to steroids, diagnosing IgG4-related RPF early can prevent the exposure of patients with RPF to unnecessary diagnostic and therapeutic interventions. Retroperitoneal fibrosis (RPF) is a rare heterogeneous disease of unknown etiology characterized by inflammation and fibrosis of the retroperitoneum that often presents a diagnostic challenge. Immunoglobulin (Ig)G4-related RPF (IgG4-RPF) is a progressive fibroinflammatory immune-mediated disease characterized by mass-forming, potentially destructive, inflammation and fibrosis in the soft tissues of the retroperitoneum. It is associated with elevation of serum IgG4 levels and infiltration of IgG4-positive plasma cells in single or multiple organ tissue sites. The diagnosis will often be delayed owing to an absence of clinical symptoms or because differentiation from other disease processes can be challenging. Therefore, a high level of diligence is required in the investigation of this condition when it is suspected. We have reported such a case of IgG4-related disease (IgG4-RD) with RPF affecting the abdominal aorta and common iliac arteries. The patient provided written informed consent for the report of his case details and imaging studies.A 73-year-old white man had presented to the emergency department with a 3-week history of left flank pain radiating to the groin and associated with dark urine. His background included hypercholesterolemia, chronic obstructive pulmonary disease, and an episode of pancreatitis 20 months previously that had been suspected to be related to statin use . He deniMycobacterium tuberculosis  were negative.On physical examination, his height was 181 cm and his weight was 86 kg. His blood pressure was 177/89 mm Hg, and his heart rate was 65 bpm. His abdomen was soft, with some tenderness in the lower abdomen and both flanks. He had no skin or subcutaneous lesions. His full blood count and renal and liver function test results were normal, his erythrocyte sedimentation rate was 82 mm/h, and his C-reactive protein level was 36 mg/L. His serum IgG4 levels were increased at 3.26 g/L , and the test results for rheumatoid factor, antithyroid peroxidase antibodies, antinuclear antibodies, antineutrophil cytoplasmic antibodies, and PR3/myeloperoxidase antibodies were negative. In addition, serology for hepatitis B and C virus, human immunodeficiency virus, syphilis, and On presentation, a computed tomography (CT) angiogram showed extensive para-aortic soft tissue changes around the abdominal aorta and common iliac arteries causing left ureteral obstruction and moderate hydronephrosis of the left kidney . At thisA subsequent positron emission tomography (PET)-CT scan  revealedIgG4-RPF was diagnosed, and the patient began oral steroid therapy (1 mg/kg weight) and mycophenolate mofetil, which was titrated to 1 g twice daily. A ureteral stent was inserted to relieve the hydronephrosis. A repeat CT angiogram at 1 month demonstrated a stable appearance of the aortic wall thickening with no relapse of the hydronephrosis. Repeat CT and magnetic resonance imaging scans of the chest, abdomen, and pelvis at 12 months after his initial presentation demonstrated resolution of the retroperitoneal soft tissue changes with no evidence of hydronephrosis or ureteral dilatation. The mediastinal disease noted on the PET-CT scan had also resolved . ClinicaRPF is a rare disorder characterized by the presence of chronic inflammation and fibrosis in the retroperitoneal space.IgG4-RD is a progressive fibroinflammatory condition believed to be secondary to dysregulation of the CD4 T-lymphocytes and plasmablasts. The hallmark features of IgG4-RD include lymphoplasmacytic inflammation, infiltration by IgG4-positive plasma cells, and distinct storiform fibrosis. It is a rare systemic autoimmune disease that can affect a variety of structures . The correlation of autoimmune pancreatitis and elevated serum IgG4 levels was first identified in 2001 by Hamano et al,The characteristics of IgG4-RPF are similar to those of idiopathic RPF, except that a male predominance, older age, and greater incidence of postrenal acute kidney injury are prominent with IgG4-RPF.IgG4-RD often involves the aorta and includes IgG4 aortitis and IgG4 (chronic) periaortitis or periarteritis (IgG4-CP). Chronic periaortitis is a rare fibroinflammatory disorder that incorporates idiopathic RPF, inflammatory abdominal aortic aneurysms, perianeurysmal RPF, and IgG4-related periaortitis. Aortic involvement in IgG4-RD can be complicated by aortic wall dilatation, dissections, and inflammatory aneurysms. Aortitis must be treated urgently because inflammatory aneurysms can have a rapid growth rate and are at risk of rupture if they have a large diameter. Ig4-CP most predominately affects the infrarenal abdominal aorta and iliac arteries and can overlap with IgG4-RPF. It can be difficult to differentiate between IgG4-CP and IgG4-RPF, such as in our case, because both conditions can demonstrate similar radiologic findings of nonspecific inflammatory or fibrotic tissues in the periaortic retroperitoneum that encases adjacent structures. Similar to IgG4-RPF, patients with IgG4-CP will demonstrate a good clinical response to steroids. In general, no significant differences exist in the response to therapy and relapse rates between these two groups. However, theoretically, the risk of developing aortic aneurysms is increased with IgG4-CP, which should alert the physician to perform close monitoring for this complication.18F-fluorodeoxyglucose PET-CT examinations for the detection of vascular inflammation in patients with IgG4-RD. It can be difficult to obtain tissue samples from the retroperitoneal lesions; thus, 18F-fluorodeoxyglucose PET can be used to reveal sites of other active inflammatory lesions more amenable to tissue sampling, such as the mediastinal lesions in our patient. Otherwise, para-aortic tissue would need to be considered for biopsy. This can be a difficult and challenging area to access for biopsy and is a high-risk procedure owing to the potential arterial complications.The reference standard for the diagnosis of IgG4-RD involves confirmation of the histologic features such as storiform fibrosis, which is characteristic of IgG4-RPF and is more sensitive and specific than elevated serum IgG4 levels. Umehara et alKhosroshahi et alAlmeqdadi et alRPF due to IgG4-RD is a rare clinical condition, and the spectrum of clinical manifestations is highly varied. Early diagnosis and differentiating IgG4-RPF from other diseases can result in success with medical treatment and prevent unnecessary surgical intervention. In the present case, we demonstrated successful resolution with the use of corticosteroids and immunomodulation with mycophenolate mofetil.


Silica-fume–polyvinyl-alcohol-fiber-reinforced concrete (SPRC) is a green and environmentally friendly composite material incorporating silica fume and polyvinyl alcohol fiber into concrete. To study the impact resistance of SPRC, compressive-strength and drop hammer impact tests were conducted on SPRC with different silica-fume and polyvinyl-alcohol-fiber contents. The mechanical and impact resistance properties of the SPRC were comprehensively analyzed in terms of the compressive strength, ductility ratio and impact-energy-dissipation variation. Based on the impact resistance of the SPRC, the impact life of SPRC with different failure probabilities was predicted by incorporating the Weibull distribution model, and an impact damage evolution equation for SPRC was established. The impact life of SPRC under the action of silica-fume content, polyvinyl-alcohol-fiber content and failure probability was analyzed in depth by the response surface method (RSM). The research results show that, when the content of silica fume is 10% and the content of polyvinyl alcohol fiber is 1%, the compressive strength and impact resistance of SPRC are the best. The RSM response model can effectively predict and describe the impact life of SPRC specimens under the action of three factors. Concrete is widely used in engineering as an integral part of the construction field ,2. For eCurrently, the problem of how to enhance the impact resistance of concrete has been widely studied by researchers. To enhance impact resistance, some researchers have incorporated fibers in concrete . ExampleSilica fume is the industrial waste produced by ferroalloying plants. Incorporation of silica fume in concrete can reduce the amount of cement and save mineral resources. The reuse of silica fume can improve the environment, save energy, reduce emissions and reduce secondary pollution. Importantly, silica fume has high activity, pozzolanic activity and a microaggregate filling reaction, which can improve the mechanical properties and durability of concrete . Silica Polyvinyl alcohol (PVA) fiber is a synthetic fiber with acid resistance, alkali resistance, high strength and high modulus. As a reinforcing fiber, it has the advantages of high deformation capacity, superior tensile properties and excellent fracture properties, which have been recognized by the material-science and engineering community ,33,34. LSome scholars have improved the mechanical properties and durability of concrete by mixing fiber and mineral materials ,43,44,45The cement was P.O 42.5 grade ordinary silicate cement from Wuhan Xinhua Company. The aggregates were from Wuhan. The coarse aggregate was ordinary graded gravel with particle size of 5 to 25 mm. The fine aggregate was Grade II medium sand with continuous grading and a fineness modulus of 2.83. The fly ash was Grade I fly ash from Henan Hengyuan New Materials Co. Ltd. The silica fume was produced by Henan Yixiang New Materials Co. Ltd. Polyvinyl alcohol fiber was produced by Kuraray Japan. The detailed parameters of silica fume, fly ash, cement and polyvinyl alcohol fiber are shown in 3. The mixing proportion is shown in The SPRC was based on C40 concrete (the cube compressive strength of 150mm side length was 40 MPa) as the base mix ratio. The 100 mm × 100 mm × 100 mm cubed specimens were taken for the compressive-strength test, and three specimens were made from each group. Cylindrical Φ 150 mm × 63 mm specimen test blocks were taken for the drop-hammer impact tests, and six specimens were made from each group. The water–binder ratio was 0.43, the content of the silica fume  was varied by cement weight, and the content of polyvinyl alcohol fibers  was varied by the volume of the entire mixture. The water-reducing agent content was 1 kg/mThe specimens were prepared by an HJS-60 type twin-shaft concrete test mixer. Considering that polyvinyl alcohol fibers tend to agglomerate, the fibers were torn and dispersed by hand before being added to the mixer. In the mixing process, the first step was to add gravel and sand and mix for 1 min; then, cement, fly ash and silica fume were added and mixed for 1 min; finally, part of the water and the water-reducing agent were added and mixed for 2 min. The second step was to add the treated polyvinyl alcohol fiber evenly into the mixer and to continue to mix for 2 min after adding; then, the remaining water and water-reducing agent were added and mixing was continued for 2 min. To avoid uneven distribution of polyvinyl alcohol fiber in the concrete, the mixing time was extended appropriately. After mixing, the mix was poured into molds for full pounding. After pounding, the specimens were placed in a cool place for 24 h to demold, and the specimens were stored in a standard maintenance room for maintenance treatment.The compressive-strength tests were performed according to the standards specified in GB/T 50081-2019  and CECSThe impact test method adopted was the drop-hammer impact test method recommended by the American Concrete Association ACI 544 standard . The met2 crystals attached to the interfacial transition zone, which leads to the increased porosity and looser network structure in this region. Silica fume has high volcanic ash activity. The SiO2 in silica fume can react with Ca(OH)2 crystals produced by cement hydration to generate a C-H-S gel by a secondary hydration reaction, which reduces the pore volume and pore distribution in the interfacial transition zone and improves the network structure in this region, increasing the compressive strength.The compressive-strength test results and compressive-strength changes are shown in With the increase in polyvinyl alcohol fiber content, the compressive-strength growth rate of SPRC was also significantly improved. This is because, when the specimen is subjected to load, the stress is often formed at the crack tip inside the specimen. With continuous loading, the stress at this tip also increases, leading to the extension of cracks inside the specimen, thus forming more cracks and eventually causing damage to the specimen. The polyvinyl alcohol fiber bridging effect exists, and fiber incorporation will form a complex force system in the concrete. This causes the concrete to be subjected to an external load, and polyvinyl alcohol fiber will form a reverse stress at the crack tip to offset part of the energy generated by the external load, thereby delaying the growth and extension of cracks so that the tolerance has been increased, and the strength has been improved.However, a high silica-fume content and a high polyvinyl-alcohol-fiber content are not always better. When the content of silica fume exceeds 10%, the compressive-strength growth rate of the SPRC begins to decline. This is because the specific surface area of the silica-fume particles is large. When the silica-fume content is too large, silica-fume particles will adsorb more free water in cement composites. This reduces the content of water involved in the cement hydration reaction, and the hydration degree of the cement-based composites decreases, resulting in a downward trend in the compressive strength with a continuous increase in silica-fume content. When the polyvinyl-alcohol-fiber content is more than 1%, the compressive-strength growth rate of the SPRC also shows a downward trend, which is due to excessive fiber content that makes the cementitious material unable to be fully wrapped, which causes stress defects inside the specimen, resulting in compressive strength decreases with increasing polyvinyl alcohol fiber content.The strength of the impact resistance of SPRC is reflected by the impact energy consumption In Equation (1): 2), 9.81 m/s2;In Equation (2): As seen from After the specimen is subjected to repeated drop-hammer impacts, the internal cracks will extend and expand after the impact load. With the increasing number of impacts, the damage deterioration inside the concrete will gradually intensify, and the specimen will eventually experience failure damage. Due to a large number of irregular microcracks, micropores and other defects in concrete, the damage to a concrete structure under repeated drop-hammer impacts has great randomness. Impact damage can be regarded as a kind of random distribution variable that must conform to a certain statistical law. The Weibull distribution model ,50,51 haIn Equation (3): Due to the similarity of the failure mechanism between the impact failure and fatigue failure of specimens, the impact life In Equation (4): Its cumulative distribution function In Equation (5), After determining the survival rate Then, the failure probability function The survival rate function Taking the natural logarithm twice for both sides of Equation (9), Equation (10) is obtained.Let Equation (10) can be used to test whether the test data obey the distribution law of the Weibull probability density function, and the test data are subjected to linear regression analysis to find the parameters To verify whether the impact life of specimens conforms to the Weibull distribution, there should be a good performance relationship between In Equation (12): Through Equation (9) to Equation (12), with From Equation (13) can be obtained by deformation according to Equation (8) to Equation (12). The impact life of the SPRC under different failure probabilities The parameters In the previous section, the impact life of SPRC with different failure probabilities was predicted using the Weibull probability density function, but the damage variation in the SPRC from the first impact load until impact damage occurred was not systematically studied. In this section, the macroscopic-damage evolution law of each group of specimens after repeated drop-hammer impacts was studied by establishing the SPRC impact-damage model using the Weibull distribution.With the increase in drop-hammer-impact times, the function value of the Weibull distribution failure probability function also gradually increases, which is an increasing function. From the process of damage deterioration under impact loading, it is clear that the impact-damage degree of the concrete increases with the number of impacts, and with the superposition of impact damage to concrete from each impact load, the fatigue damage from impact loading is a growth process. It can be considered that the damage degree and failure probability accumulate simultaneously in the process of drop-hammer impact.After According to the impact-damage-evolution equation in Response surface method (RSM) is an optimization method that responds to core elements by multiple factors . The funIn Equation (15), RSM analysis design and results are shown in The variance analysis of the impact life response model of the SPRC is shown in The RSM scheme was imported into Design-Expert to analyze the effect of the variation in Factor A (silica-fume dosing), Factor B  and Factor C (failure probability) on the significance of the impact life of SPFC. The contour map and 3D response surface map derived from the model are shown in Through the analysis of As seen from As seen from With the increase in silica-fume and polyvinyl-alcohol-fiber content, the compressive strength and impact energy dissipation of SPRC first increase and then decrease. When the silica-fume content is 10% and the polyvinyl-alcohol-fiber content is 1%, the compressive strength and impact resistance of SPRC are the best, and these values are 26.6% and 154.23% higher than those of the benchmark concrete, respectively.The SPRC impact life test results obey the Weibull distribution probability density function well; thus, the Weibull distribution model can be used to effectively predict the impact life of SPRC under different failure probabilities.The equation of the SPRC impact damage evolution is established based on the Weibull distribution model. The predicted values of the model are in high consistency with the experimental results. This indicates that the model has high reliability and can accurately describe the damage degradation process of the SPFC under repeated impact loading.The RSM model was established by combining the level changes of the three factors. The results show that the model has high significance, validity and reliability. Therefore, the impact life of SPRC under the action of these three factors can be effectively predicted.SPRC was prepared and tested for compressive strength and impact resistance, and the results were analyzed in depth using the Weibull distribution model and RSM. The following conclusions can be drawn from the results obtained:


In highway transportation infrastructure such as highways and tunnels, the proportion of concrete consumption is the highest, and concrete cracks are common concrete problems. Concrete cracks will greatly affect the bearing capacity and safety of the structure, easily leading to the interruption of transportation lines, causing great economic losses, and endangering personnel safety. Therefore, the effective identification and timely reporting of concrete cracks is of great significance for the maintenance of infrastructure such as roads and tunnels. In this paper, the CaNet, a deep learning network for identifying concrete cracks, is proposed, which takes ResNet50 as the backbone network. In order to capture the area with a small proportion of cracks, we added coordinate attention to the residual unit of ResNet50 to capture the cross-channel information, direction-aware information, and position-sensitive information from many vertical and horizontal directions so that the network can more accurately locate the narrow crack area. In experiments 3.2 and 3.3, the CaNet has an accuracy rate of 89.6%, which is higher than that of the compared network. In addition, the recall, F1 score, and precision of the CaNet network are 86%, 85%, and 87% , respectively. Therefore, the CaNet model is effective for identifying concrete cracks. The rapid take-off of the world economy benefits from the stable and sustainable development of the transportation industry to a certain extent. Highways and tunnels are the carriers of the land transportation industry , and theIn real life, manual patrol inspection is still used for the patrol inspection and maintenance of cracks on the surface of highways and tunnels, relying on close observation with the help of width measuring instruments, tape, and other measuring instruments to complete the collection of crack information and mark and record the crack information in time . HoweverTo solve the problems encountered in manual inspection, the traditional digital image processing technology for concrete cracks is widely used . For exaCompared with the traditional digital image processing technology, the extensive promotion of deep learning has greatly improved the ability of concrete crack feature extraction and feature expression . At the Based on ResNet50 in the ResNet series  as the bThe CaNet is proposed: coordinate attention is introduced, which enhances the extraction of micro features of concrete cracks and improves the recognition accuracy of crack images by 6.2% to ResNet50.Compared with several neural networks set up in the experiment, the CaNet has a higher recognition rate in the identification of concrete cracks.The main contributions of this paper are as follows:In the second section, we introduced the dataset (2.1) used in this paper and the constituent elements of the CaNet (2.2); the third chapter introduces the experiment performed in this paper, in which 3.1 describes the hardware and software configured for this experiment; 3.2 tests the practicality of the model; 3.3 tests the effectiveness of coordinated attention; 3.4 tests the comparison with other models. The fourth chapter introduces the conclusions and shortcomings of this paper.The quality of the concrete crack dataset can greatly affect the designed network , 20. ThiIn CaNet, the main structure of ResNet50 is used. On each floor, 1 × 1 and 3 × 3, coordinate attention is added between convolution blocks. The network structure of CaNet is shown in In the field of recognising concrete crack images, the depth convolution neural network has produced ideal results recently . The amox represents the input characteristic diagram of RB; H represents the output characteristic diagram of RB; F represents the residual mapping of the network. The dimension of input x must be the same. If the dimension is different, Wq linear projection should not be added to the shortcut connection, as shown in the following formula:ResNet50 is a network structure commonly used in various fields, which is formed by stacking different residual blocks. Residual block (RB) is shown in formula :The 2D global pool is used to calculate channel attention in the most widely used squeeze and stimulate (SE) attention mechanism. However, SE only takes into account the coding of information between crack channels for concrete crack images, ignoring the significance of concrete crack location data, which is crucial for capturing the object structure in concrete crack recognition. Using the convolution layer to calculate the spatial attention information of concrete cracks, BAM  and CBAMIn order to address this issue, Hou et al.  suggesteSpecific implementation process isX is encoded using a pooling kernel of size  or , respectively.Each channel of input c channel with h height can be expressed asThe crack features output of c channel with w width can be expressed asThe crack features output of F1 stands for 1 × 1 convolution kernel; δ indicates nonlinear activation function; f ∈ ℝC/r×(H+W) represents the intermediate feature map for coding the spatial information of cracks, and r represents the reduction rate of control block size.After the transformation in information embedding, this part concatenates the feature map after f ∈ ℝC/r×(H+W) in step 2 into fh ∈ ℝC/r×H and fw ∈ ℝC/r×W. Then, use 1 × 1 convolution kernels to transform fh and fw.σ stands for the sigmoid function. Both Fh and Fw represent 1 × 1 convolution. gh and gw represent weight characteristics.Divide gh and gw with input X and output coordinate attention block Y, as shown in the following equation.Use multiplication to fuse weights In this experiment, the network training and testing environments were carried out on a platform. The experimental parameters of training and testing are shown in The concrete crack dataset used this time is the Surface Crack Detection public dataset with 40000 images, which are divided into two types, crack free images and crack images. In all experiments of this paper, according to the ratio of 7 : 2 : 1, the dataset will be divided into the training set, test set, and verification set.Concrete is indispensable in today's construction projects and is the most widely used building material. It is widely used in the construction of infrastructure such as roads, bridges, housing construction, tunnels, and dams. Concrete cracks are the most common quality problem in concrete subprojects. Due to the low tensile strength of concrete and the combined effects of internal and external influences, such as shrinkage and creep, external temperature changes, and foundation deformation, concrete in construction and operation is used. Structures often have cracks to varying degrees and forms, and it is still impossible to completely prevent and eliminate them. Therefore, efficient inspection and monitoring of concrete cracks have become the key to ensuring the quality of concrete projects. Accurately identifying the length, direction, and width of cracks in concrete structures plays an important role in judging the disease degree and operating conditions of the structure.Surface-based crack identification is a considerable task in health monitoring of structures. If cracks continue to expand, they will reduce the effective bearing surface area and can lead to structural failure over time. On the one hand, the detection process of manual cracks is time-consuming and labor-intensive, subject to the subjective judgment of inspectors, and for high-rise buildings and bridges, due to the large operational limitations, manual inspection may also be difficult to perform. On the other hand, although the image recognition technology of AI has been improved dramatically, and the technology of automatically detecting cracks through image recognition has been developed, most of them still require manual image acquisition work, and a lot of high-resolution image data are obtained, but it still takes a considerable amount of time and cost to record the crack detection and make the result file. Therefore, in this paper, we build a convenient and accurate crack identification model based on coordinate attention and test the model on real-world data  At present, the focus of the research is to identify the concrete crack images of highways and tunnels to complete the classification task. Later, it can be extended to the detection task of wall cracks and metal cracks. (2) The data in this network training are all from the public dataset. In the future, cameras, smartphones, and other shooting equipment should be used to collect concrete crack images in different scenes, expand the dataset, and improve the generalization of the model.