Promising areas of concrete material science are maximum greening, reducing the carbon footprint, and, at the same time, solving the problems of increasing the cost of raw materials using industrial waste as modifiers for self-compacting concrete mixtures. This study aimed to review, investigate and test from the point of view of theory and practice the possibility of using various industrial types as a nano-modifier in self-compacting concrete with improved performance. The possibility of nano-modification of self-compacting concrete with a complex modifier based on industrial waste has been proved and substantiated theoretically and experimentally. The possibility of improving the technological properties of concrete mixtures using such nanomodifiers was confirmed. The recipe and technological parameters of the process were revealed and their influence on the characteristics of concrete mixes and concretes were expressed and determined. Experimental technological and mathematical dependencies between the characteristics of the technological process and raw materials and the characteristics of concrete mixtures and concretes were determined. The optimization of these parameters was carried out, a theoretical substantiation of the obtained results was proposed, and a quantitative picture was presented, expressed in the increment of the properties of self-compacting concrete mixtures using nano-modifiers from industrial waste concretes based on them. The mobility of the concrete mixture increased by 12%, and the fluidity of the mixture increased by 83%. In relation to the control composition, the concrete strength increased by 19%, and the water resistance of concrete increased by 22%. The ultimate strains decreased by 14%, and elastic modulus increased by 11%. The growing requirements for the quality of building materials, products, and structures ,2,3, theThus, this article focuses attention on high-tech processes for constructing reinforced concrete and concrete buildings and structures of a new type. As is known, in current conditions all over the world, the main requirements are not only high quality and speed of construction of buildings and structures, but also the maximum environmental friendliness and efficiency of such construction in the face of rising prices for energy, raw materials, machinery and equipment, and increased requirements for the wages of workers. Thus, one of the main directions is also greening and achieving maximum efficiency of construction processes in the construction of reinforced concrete buildings and structures. In this regard, one of the promising areas is the development of the most technologically advanced, highly functional concrete mixtures of a new generation, which allows achieving savings using a minimum amount of means for transportation, laying, compaction, care of hardening concrete, the possibility of the fastest construction of buildings and structures with the most attentive ensuring proper quality. Self-compacting concrete mixtures are mixtures of a new generation. They allow bypassing such problems of current construction as the high-density of reinforcement and the impossibility of manual or machine compaction of the concrete mixture in hard-to-reach concrete structures, minimize costs for all stages of the life cycle of the construction process, and ensure the excellent quality of the construction process as soon as possible in the construction of reinforced concrete buildings and structures. From this point of view, concerning improving the quality and manufacturability of self-compacting concrete, many works are known.At the same time, as mentioned above, a critical condition is maximum greening, reducing the carbon footprint, using the possibility of maximum greening of the environment, reducing the environmental burden, and solving the problems of increasing the cost of raw materials. In this regard, the search for technological, constructive, recipe approaches, the use of several types of waste, industrial and agricultural and other wastes of economic entities and humans as modifiers of self-compacting concrete mixtures, are also seen as promising areas.Superplasticizers can produce self-compacting concretes (SCC) containing various particulate materials such as Portland cement, mineral additives, fillers, and fine and exceptionally fine sand. The addition of a superplasticizer makes it possible to preserve the rheological properties of the concrete mixture for a time sufficient for the transportation and molding of products and structures . The infThe use of finely dispersed mineral additives makes it possible to improve the technological characteristics of self-compacting concrete mixtures and the physical and mechanical properties of concrete. At the same time, the most significant effect in the mentioned improvement can be achieved when using rationally selected combinations and dosages of mineral additives together with a superplasticizer, optimizing the granulometric composition of aggregates, which makes it possible to obtain high-strength concrete as a result ,9,10. ThThe structure-forming role of mineral additives is to reduce the induction period of structure formation due to the adsorption of hydrolysis products and to increase the time to reach supersaturation of the liquid phase. Thus, the mineral additive activates the processes of hydration of the binder and promotes an increase in the volume and degree of crystallinity of the formed hydrates, which contributes to the compaction of the structure at the point of contact with the additive with a significant increase in the microhardness of hydrate aggregates .The joint inclusion of a superplasticizer and a mineral additive into a self-compacting concrete mix increases the effect compared with the use of only one of these types of additives. In the example of cement stone, the differences in the relative value of the modulus of elasticity are presented when using only a superplasticizer (an increase of up to 10%) and when using a superplasticizer with a mineral additive (an increase of up to 20%) ,28.Thus, the use of complex additives  makes it possible to reduce the consumption of cement, maintain the workability of concrete mixtures for a long time, increase the density of the structure, and, as a result, the strength, durability, and resistance of concrete under aggressive operating conditions .In , the autOne of the most “focused on the maximum use of industrial waste as modifying additives for self-compacting concrete” are works ,36,37,38Having reviewed and analyzed the previously achieved results and technological methods obtained by other authors ,43,44,45The working hypothesis of the study is the possibility of improving the manufacturability of self-compacting concrete mixtures using nano-modifying additives from several types of waste, thereby making it possible to achieve an increase in the manufacturability, efficiency, and environmental friendliness of the construction process.The study is aimed to review, investigate, and evaluate from the point of view of theory and practice the possibility of using various types of industrial and agricultural waste as nano-modifiers in self-compacting concrete with improved characteristics.-formulation of the problem based on data on the modification of concrete mixtures with a reorientation of the study in the direction of nano-modification with the waste of this type;-conducting approbation studies with a detailed study of the initial components selected based on the most common wastes that accumulate in large quantities and pose the greatest potential threat to the environment;-after selecting, determining, and establishing the initial characteristics of the base raw material-determining the working compositions for optimizing and testing the hypotheses put forward, conducting large-scale experimental studies with fixing the technological characteristics of self-compacting concrete mixtures as criteria and checking them to verify the resulting characteristics of highly functional concrete from such mixtures;-summarizing the results of the study, determining the technological properties of concrete mixes and the performance characteristics of concrete, putting forward subsequent scientific hypotheses, and developing proposals for applied use in building materials science and technology of building processes, determining the goals and objectives of subsequent research, as well as proposals for industrial approbation of the results obtained after their detailed comparison with the results of other authors and understanding of the scientific novelty and place of the research in construction science and practice.The research objectives comprise:The program study is presented in Considering the complexity of the study and its division into the study of the technological parameters of the concrete mixture, and the verification of the results achieved by the characteristics of the obtained concrete, a complete list of the materials and research methods used are presented.When conducting experiments for the preparation of cement pastes and self-compacting concrete mixtures, Portland cement PC 500-D0-N produced by Holcim (Rus) LLC  was used as a binder. The chemical and mineralogical composition of Portland cement clinker is presented in As mineral additives, the following are accepted: fly ash from the Novocherkassk State District Power Plant  and micro-silica grade MS-85 produced by ZIPo LLC . The chemical composition and physical and mechanical characteristics of fly ash are given in Mf = 2.2) produced by Arkhipovsky Quarry JSC  and quartz sand (Mf = 1.2) produced by Quartz Sands LLC . Physical and mechanical properties of aggregates are presented in Granite crushed stone produced by Pavlovsknerud JSC  was used as a coarse aggregate, and quartz sand ; superplasticizer C-3 manufactured by Component LLC . The qualitative characteristics of the additives used are presented in -analytical methods and literature data study;-phenomenological methods for the selection and determination of raw materials, compositions, and the setting of allowable limits and ranges;-experimental studies to verify the selected recipe and technological solutions;-mathematical methods of substantiation and optimization of the developed proposals.The research methods can be conditionally divided into groups:-determination of the characteristics of the initial raw materials by standardized methods for binder and aggregates and research methods of laser granulometry for nano-modifying additives;-determination of the technological characteristics of concrete mixes by standardized methods with verification of the results by the author’s method;-determination of the characteristics of the resulting concrete by standardized methods ,54,55,56Experimental studies were carried out using standardized and unique methods, including:The determination of the granulometric composition of powdered raw materials (fly ash and micro-silica) was carried out using the method of laser granulometry. A Microsizer 201C laser particle analyzer  was used for granulometric analysis .X-ray phase analysis (XPA) of mineral additives was carried out on an X-ray diffractometer HZG-4C .−1).The rheological properties of cement pastes  were studied using a B085-21 rotational viscometer . The results were processed according to the Bingham rheological model :(1)τ=τ0+The workability of a self-compacting concrete mixture is characterized by its ability to slump-flow and fill a given shape under the action of its mass or external forces while maintaining uniformity and solidity. Indicators of the technological properties of self-compacting concrete mixtures are such characteristics as mobility, expressed by the diameter of the flow of a standard cone and fluidity, expressed by the flow time of the concrete mixture from a V-shaped funnel. The mobility of the concrete mixture was estimated by the diameter of the flow in millimeters using a standard cone , the appearance of the cone is shown in To evaluate and verify the results of standard methods, taking into account the specifics of the resulting mixtures, additional tests were carried out using a non-standard method, according to .Compression tests were carried out on 100 mm × 100 mm × 100 mm sample cubes a of six Determination of the elastic modulus and axial compressive strength (three prism samples 100 mm × 100 mm × 400 mm for each SCC composition) was carried out following the requirements of GOST 24452-80 “Concretes. Methods of prismatic, compressive strength, modulus of elasticity and Poisson’s ratio determination” .Measurements of the strains of the concrete samples were carried out with the chain of strain gauges with a base of 50 mm and dial indicators with a division value of 0.001 mm on the experimental prisms. In addition, tests of experimental prisms for axial compression and axial tension were carried out at a constant strain rate to obtain the strength and strain characteristics of concrete and its complete strain diagrams “σ-ε” with descending branches.The water-resistance of SUB samples was determined by the “wet spot” method following the requirements of GOST 12730.5 “Concretes. Methods for determination of water tightness”  on cylinThe water pressure was increased stepwise with 0.2 MPa for 1–5 min and maintained at each step for 16 h . The watAll manufactured prototypes hardened under normal conditions at a temperature of 20 ± 2 °C for 28 days.The study used mathematical planning of the experiment, which aims to increase the efficiency of experiments.In particular, the Box–Wilson method was applied-orthogonal planning of the optimal experiment. The essence of the chosen method is as follows:In the first stage, for some local area of existence of the object under study, the regularities of its behavior are determined by the method of planning the experiment, and as a result of their analysis, the direction to the optimum is determined, in which the parameters should be changed. Next, another experiment is carried out in a new area of the object’s existence, and so on, until optimal conditions are reached.(a)minimizing the number of experiments;(b)changing the parameters that affect the state of the object according to a certain law;(c)using a mathematical method that formalizes the actions of the experimenter in data processing and obtain a mathematical model of the research object;(d)use the logical apparatus when making decisions based on the analysis of the resulting model.Mathematical planning of an experiment is a formalized procedure for choosing the number and conditions for conducting experiments that are necessary and sufficient to solve a problem with the required accuracy. This procedure allows for the following:-revealing the influence of the type of dispersion medium on the efficiency of dispersion of the nano-modifier;-to determine and evaluate the rheological properties of cement pastes with a complex nano-modifier;-based on the data obtained, optimize the compositions according to the criteria of strength and deformability of concrete and the mobility of concrete mixtures.Following the recommendations ,36,37,38The granulometric characteristics of the mineral additives are shown below in Following the data shown in X-ray phase analysis of fly ash and micro-silica particles is shown in 6Si2O13 mullite and an X-ray amorphous phase referred to as a glass, while the main phase is the mullite phase. Micro-silica ;sodium hydroxide solution (concentration 1.5% in terms of Na-solution of sodium hydroxide and superplasticizer (concentration 2.5%).Following the recommendations ,36,37,38The preparation of an aqueous suspension of silica fume was carried out in a laboratory planetary ball mill “Activator-4M” for 8–12 min.After the dispersion process, the predominant part of the micro-silica particles (more than 80%) is in the range of 2 to 35 µm, and the main peak falls at 10 µm.The dispersing ability of liquids was assessed by the kinetics of sedimentation of aqueous suspensions of silica fume , the conThe authors of works ,36,37,38In the presence of alkali, silicon dioxide goes into solution in the form of a silicate ion, followed by interaction with water to form soluble mono silicic acid. When the amount of alkali is small, mono silicic acid can polymerize to form stable colloidal particles. In the soluble sodium silicate formation process, an additional dispersion of amorphous silica occurs with a transition to a highly concentrated state-a lyosol nano dispersed system. In addition, the degree of micro-silica grinding is exclusively influenced by the self-heating temperature of the suspension during grinding, which is achieved mainly due to the work of friction.When micro-silica is dispersed in the medium of sodium hydroxide and superplasticizer solutions, a colloid system stabilized by a surfactant is formed, which retains sedimentation stability for more than 10 days ,37,38.Thus, a solution of sodium hydroxide and a superplasticizer (concentration 2.5%) was chosen as the dispersion medium.Further, following the developed program, it was necessary to evaluate the rheological properties of cement pastes with different content of complex nano-modifiers . The rheDuring experiments on the selected initial formulation and technological parameters, the data ,36,37,38To summarize, it can be noted that the partial replacement of Portland cement with fly ash in 40% slightly increases the water demand and plastic viscosity of the cement paste (P3) as established ,36,37,38Rb,cub), mobility (dsl), and flow (Tfl) parameters served as optimization parameters. The basic composition of concrete was adopted for testing, determined according to the method [To optimize the composition of concrete (modifier) in terms of the consumption of mineral and chemical additives, studies were carried out using the method of orthogonal compositional planning of the 2nd order of Box–Wilson, which, under specific optimal parameters, allows achieving the maximum strength of concrete at the age of 28 days while ensuring the required mobility of concrete mixtures. Thus, the compressive strength –(4) were obtained:The significance of the regression equation coefficients was checked using the Student’s test, and the adequacy of the regression equations to the experimental data was checked using the Fisher criterion.After verification, insignificant coefficients were discarded, resulting in Equations (5)–(7):Graphical interpretation of the obtained polynomial dependencies is shown in 1 and X2 have the greatest influence on the compressive strength of the SCC. The optimal dosage of fly ash introduced to replace part of the cement is a dosage of 40% by weight of cement. As for the dosage of NaOH, the optimal dosage is 0.8% by weight of cement.An analysis of the regression equations shows that the factors XIt should be noted that for compositions No. 3, 4, 7, 8, 11, 12, 15, 16, where the content of fly ash in the SCC composition is 50%, lower values of compressive strength are observed in comparison with other compositions and vary from 28.9 MPa and up to 33.6 MPa; the minimum strength value was recorded for composition No. 22 with a fly ash dosage of 55% and is 27.8 MPa.The X3 factor has a significant impact on mobility, increasing the dosage of the C-3 plasticizer from 1.1% to 1.8% increases the mobility of the self-compacting concrete mix. The maximum value of the mixture flow diameter was recorded for composition No. 22, where the C-3 dosage was 1.8% of the cement weight.3  and X4  have the greatest influence on this indicator. The highest values of fluidity were recorded for compositions No. 13, 14, 16, 20, and 22 and amounted to 25–26 s. The lowest values of fluidity are observed in compositions No. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 23 and vary from 13 to 17 s. An increase in the dosages of superplasticizer and micro-silica additives contributes to an increase in the flow time of the concrete mixture, which can be directly related to an increase in the viscosity of the mixture itself.As for such a parameter as the flowability of a self-compacting concrete mix, the factors XComparative tests of concretes and concrete mixtures of the control composition (CC) and with a complex nano-modifier (CNM) are presented in Comparative tests of the control composition of concrete and nano-modified one show that the alkaline activator in the composition of the complex nano-modifier allows partial replacement (40%) of Portland cement with fly ash while increasing the compressive strength of concrete by 17%, the axial compressive strength by 10%, the strength for axial tension by 19%, and the tensile strength in bending by 11%. Ultimate strains under axial compression and tension decreased by 14% and 12%, respectively. The modulus of elasticity increased by 11%. As for water resistance, its value increased by 22%.As can be seen in Higher indications of the early strength of the CNM composition can be theoretically justified in accordance with ,36,37,38As noted earlier, organomineral additives introduced into the cement system in the form of compositions (mixtures) with a superplasticizer with an optimized particle size distribution of aggregates make it possible to obtain high-tech self-compacting concretes. At the same time, such concrete mixtures are characterized by sufficient viscosity to prevent mixture separation and the sedimentation of large aggregates ,36,37,38b-σb” and tension “εbt-σbt” were constructed. Graphic dependencies are shown in Also, according to the test results, “stress-strain” diagrams of compression “εAfter experimentally obtaining “stress-strain” diagrams for cases of axial compression and cases of axial tension and their changes depending on the composition, their more detailed interpretation should be given with an explanation of the results obtained. So, the resulting stress-strain diagrams, both in compression and tension are presented in A thorough evaluation of the data got in this research with the results of other authors should be made to assess the authors’ contribution to the science and practice of production and construction. To better assess, it is necessary to set the criteria for a comparative assessment, which can be expressed in three aspects. First, this is a research aspect. The second is the technological aspect. And the third aspect is the result got from the point of view of operation of the final product in real construction that are special structures with hard-to-reach concrete. Their evaluation is carried out according to various characteristics and requirements that apply to these concretes.The structure of large-scale studies conducted by Professor Zaichenko N.M. ,36,37,38Summarizing the results of the identified research differences, it can be noted that a large-scale study was conducted in this paper on the nano-modification of self-compacting concrete mixtures with additives of various types. The goal was to improve the technological characteristics of the mixture and the performance characteristics of the resulting concrete. The nano-modifiers were fly ash formed during the operation of the existing state district power station, and micro-silica, which is a waste of industrial production. As a result of the study, high technological and operational indicators of concrete mix and concrete were revealed. The ecological and economic efficiency of the proposed research method, with the proposed technology formulation, has been proven. Thus, the prospects of this study and further vectors of the development of this study have been determined.From the point of view of the technological properties of the obtained self-compacting concrete mixtures, a quantitative assessment of our results is presented. The quantitative increase was up to 83% in the technological and rheological characteristics of the self-compacting concrete obtained.The third aspect of comparison is the result demonstrated by the concrete obtained on the technological mixtures proposed in terms of operational characteristics. The quantitative increase in the strength characteristics was up to 19% and up to 22% for water resistance. The reduction in ultimate strains was up to 14% and the elastic modulus increased by 11%.The increase in strength characteristics is in good agreement with the results of the authors, who previously investigated the use of complex modifiers in self-compacting concrete ,31,32,33Summarizing all three aspects, several elements of novelty can be noted. First, this research is based on large-scale studies of our colleagues around the world, considering the experience of previous studies. Second, the theory of nano-modification of self-compacting concrete mixtures was continued and developed, and specific practical results were obtained, which are proposed for development. The vector of this development is bringing nano-modifiers to an even more dispersed state. In this case, an assessment is made in terms of raw materials and the possibility of establishing the effect of even greater grinding of these components. This makes it possible to identify opportunities for further improving the manufacturability of mixtures and improving the performance characteristics of concrete. The engineering aspect of our study is proposed for implementation in those construction organizations and enterprises to produce commercial self-compacting concrete. These enterprises have the highest ecological burden on the environment and access a large array of accumulated industrial waste. Thus, these enterprises are ready to provide initial raw materials that have already been verified in studies as suitable for use.The observed results can be explained by the fact that the precipitation rate decreases in sodium hydroxide solution, which indicates a finer granulometric composition of the resulting dispersion. In a highly alkaline medium, along with the dispersion of micro-silica aggregates, its dissolution also occurs. In the presence of alkali, silicon dioxide goes into solution in the form of a silicate ion, followed by interaction with water to form soluble monosilicic acid. When the amount of alkali is small, monosilicic acid can polymerize to form stable colloidal particles. In the process of formation of soluble sodium silicate, an additional dispersion of amorphous silica occurs with a transition to a highly concentrated state-a lyosol nanodispersed system. When micro-silica is dispersed in the medium of sodium hydroxide and superplasticizer solutions, a colloidal system stabilized by a surfactant is formed, which retains sedimentation stability for more than 10 days. When replacing 40% of Portland cement with fly ash, a positive effect of a complex additive in the form of a superplasticizer C-3 + NaOH (P4) is observed in terms of SCC resistance to delamination ,37,38.Discussing the obtained results and comparing our conclusions with previous literature studies ,36,37,38For a visualization of the analysis of the proposed solutions, Thus, the most significant factors affecting the effectiveness of nano-modified self-compacting concrete mixtures with improved technological characteristics were grouped and analyzed.Branch 1  of the uBranch 3 of the lower part of the diagram shows the rheological characteristics of SCC mixtures, the values of which directly affect the quality, scope and manufacturability of nano-modified SCC mixtures and composites based on them. On branch 4 of the scheme, the factor of influence of nano-modifiers is presented in quantitative and qualitative aspects, considering their type, origin, and joint interaction. The presented four branches play a decisive role in obtaining effective self-compacting concrete mixtures with improved technological characteristics and concrete based on them.In conclusion, we theoretically and experimentally proved and substantiated the possibility of nano-modification using a complex modifier based on the industrial waste of self-compacting concrete and the possibility of improving the technological properties of concrete mixes using such nano-modifiers.Experimental technological and mathematical dependencies between input factors—the characteristics of the technological process and raw materials and output parameters of the characteristics of concrete mixes and concretes—are determined. The optimization of these parameters was carried out, a theoretical substantiation of the obtained results has been proposed, and a quantitative picture has been presented, expressed in the increment of the properties of self-compacting concrete mixtures using nano-modifiers from industrial waste and concretes based on them. In terms of the mixture, these increases were 12% for slump-flow and 83% for fluidity concerning the control composition, while in terms of concrete, these increases were up to 19% for strength indicators and 22% for water tightness to the control composition. The ultimate strain was decreased by 14%, and elastic modulus increased by 11%.A complex nano-modifier, including such waste as micro-silica and fly ash, gave positive results and demonstrated a synergistic effect in terms of saving raw materials and environmentally friendly disposal. This allows for recommending the proposed method for practical construction industry enterprises, as well as for monolithic concreting of complex densely reinforced structures.An assessment of the results obtained is given and proposals for implementation in the practical industry are developed. According to preliminary estimates, the use of this nano-modifier leads to improving in the environmental situation because of the use of a nano-modifier based on industrial waste in concrete and results in a reduction of the process cost. The cost of the final product was decreased by reducing the cost of raw materials by up to 15%.


Monopterus albus) were exposed to different MET concentrations  for 96 h to examine the effect of MET on the hypothalamic-pituitary-gonadal (HPG) axis and sexual reversal. The results showed that high concentrations of MET exposure increased vitellogenin (VTG) levels in liver and plasma, but plasma sex hormone levels were not affected by MET exposure. MET exposure increased the expression of CYP19A1b and CYP17 that regulate sex hormone production in the brain, but the expression of genes  associated with sex hormone secretion in the ovary and the estrogen receptor genes  in the liver were all suppressed. In addition, the expression of sex-related gene (Dmrt1) was suppressed. This study revealed for the first time that MET has estrogen-like effects and has a strong interference with the expression of HPG axis genes. MET did not show the ability to promote the sexual reversal in M. albus, on the contrary, the genes expression showed that the occurrence of male pathway was inhibited.Metamifop (MET) is a widely used herbicide. It is likely for it to enter water environment when utilized, thus potential impacts may be produced on aquatic animals. Little information is available about its effects on the endocrine system of fish to date. In the current study, female rice field eels ( Endocrine-disrupting chemicals (EDCs) can interfere with various aspects of biological endocrine secretion through intake, accumulation and other ways. Exposure to EDCs are thought to have an irreversible effect on animals during critically susceptible phases of sexual differentiation. Synthetic chemicals particularly used in agriculture are thought to cause endocrine disturbances in wildlife, and herbicides are among the most commonly used agricultural chemicals . For a lAryloxyphenoxypropionate (AOPP) herbicides have been widely used in paddy fields due to their excellent weed control ability. Metamifop (MET) ((R)-2-[4- phenoxy]-2′-fluoro-N-methyl propionanilide), an AOPP herbicide developed by Dongbu Hannong Chemical Co., Ltd (South Korea), can effectively control annual weeds by inhibiting the activity of acetyl-CoA carboxylase (ACCase), thereby interfering with lipid synthesis . Due to Danio rerio) embryos  and juvenile zebrafish  (Oncorhynchus mykiss) , invertebrate (Daphnia magna) , and algae . A study of quizalofop-p-ethyl, also an AOPP herbicide, showed that exposure at sublethal doses increased estrogen axis activity in male zebrafish (Xenopus laevis) were affected by MET, reflecting the endocrine interference effect of MET. To date, the impact of MET on the sex hormone of fish has not been reported, and the underlying mechanism is unclear.MET was reported to be highly toxic to zebrafish ( mg L−1) . Accordi mg L−1) , MET is ebrafish . RecentlM. albus is a commercially important freshwater species in China and very popular for its delicious taste. Although the prodution of M. albus in China was about 307,200 tons in 2020  resulted in a significant increase in plasma vitellogenin (VTG) levels in female M. albus after 4 days of exposure. VTG has been shown to be a biomarker for EDCs  axis were detected to evaluate influence of MET on the endocrine system of M. albus. The results of this work may help elucidate the mechanism of MET action on the endocrine secretion and sex reversal of M. albus. in 2020 , the supal stage . The lowfor EDCs . Therefo−1 was prepared as previously described by Metamifop  was supplied by Hubei JiangMinTaiHua Chemical Co., Ltd. . MET stock solution of 1,000 mg LM. albus with ovary developing at the third stage  were taken from Luoma Lake, Jiangsu Province, China. M. albus were acclimated in polyethylene tanks  of the Jiangsu Special Aquatic Breeding Engineering Laboratory for 1 week. During the acclimation period, the eels were fed with earthworm , with a 14 L: 10 D photoperiod. pH 7.8 ± 0.1; dissolved oxygen 9.0 ± 0.5 mg L−1; temperature 20°C ± 2°C; only exist the aerator working sound. Water was changed every other day. Feeding stopped 1 day before the experiment, and no feeding was given during all the experiment period. According to the results of preliminary experiment, the 96 h LC50 of MET to M. albus was determined to be 0.785 mg L−1. Dechlorinated tap water and 0.08% acetone and 0.0008% Tween 80 dissolved in dechlorinated tap water (v/v) were used as blank and solvent control, respectively. The concentration of MET in the experiment was set at 0.2, 0.4, 0.6, 0.8 mg L−1, respectively, and was determined using high phase liquid chromatography (HPLC). During the experiment, 144 M. albus were selected randomly into six groups, each group with three replications. Then the M. albus were placed in culture tanks . The water tanks used in the experiment were covered with gauze to prevent eels from escaping, and the physicochemical parameters of the water were consistent with those in acclimation period. Tiles were placed as shelter. The test solutions were renewed every 24 h in order to maintain MET concentration constant and dead fish were cleared at the same time.Healthy female M. albus were decapitated on ice and ovary, brain (complex of brain and pituitary) and liver tissues were collected and preserved at −80°C.After 96 h, eels were anesthetized with 3-aminobenzoic acid ethyl ester methanesulfonate (MS-222) . The blood samples were collected by severing the caudal peduncle. The blood was immediately mixed with anticoagulant (0.50‰ EDTA) and centrifuge at 1,500 rpm/min for 30 min to obtain plasma. Then the plasma was extracted and stored at 4°C for analysis. After, the Estradiol (E2), testosterone (T) and vitellogenin (VTG) in anticoagulated plasma and liver were detected by enzyme linked immunosorbent assay (ELISA), ELISA kits from Shanghai QiaoDu Biotechnology Co., Ltd.  were used following the instructions of the manufacturer.® 480 II RT–qPCR machine . The primers were designed by Primer Premier 6.0 and are shown in 2O. Cycling conditions were 95°C for 5 min, followed by 40 cycles of 95°C for 10 s, 60°C for 30 s and 72°C for 30 s. All samples were run in triplicate, and each assay was repeated three times. The threshold cycle (Ct) values were obtained from each sample. Relative gene expression levels were evaluated using 2−△△CT method . The purity, concentration and integrity of RNA samples were detected by Nanodrop, Qubit 2.0, Aglient 2,100, respectively. Single-stranded cDNA was synthesized using HiFiScript cDNA Syntheses Kit  following the instructions. The transcripts of genes were measured by LightCyclerT method .post hoc test. The critical value for statistical significance was p < 0.05. All statistical analyses were conducted using SPSS 26.0 software .Prior to conducting statistical comparisons, the experimental data which were presented as the mean ± standard deviation were assessed for normality and homogeneity of variances using the Shapiro-Wilk test and Levene’s test, respectively. The experimental data were analyzed using unifactor ANOVA, followed by SNK Statistical analysis showed that solvent had no effect on all indicators in this study. Therefore, the solvent group could be used as a control. HPLE analysis of the water samples indicated that the exposure solutions ranged approximately 93–120% of all nominal concentrations . Since ap > 0.05). However, compared with the control group, E2 and T showed a non-significant decrease at 0.2 mg L−1 and 0.4 mg L−1 of MET and a non-significant increase at 0.6 mg L−1 and 0.8 mg L−1 of MET  in the 0.8 mg L−1 treatment compared with the control (p < 0.05) in both 0.6 and 0.8 mg L−1 MET-treated groups than the control group (−1 and 0.4 mg L−1), VTG levels in both plasma and liver did not change significantly.The VTG content in plasma of female  control . In liveol group . HoweverCYP19A1b was upregulated in MET exposure groups compared with the control (by 1.6- to 2.5-folds)   . CYP17 ee groups . FSHβ wa5-folds) . The expectively .CYP19A1a and CYP17 were significantly decreased in all the MET exposed groups compared with the control (p < 0.05). Similarly, FSHR and LHCGR mRNA levels were significantly decreased at all MET concentrations compared to the control . At low MET concentration (0.2 mg L−1), both the expressive of HSD11b2 and 3β-HSD did not occur significant change. However, after the increase of MET concentration, the expressive levels of HSD11b2 and 3β-HSD were decreased. For example, the expressive level of HSD11b2 was significantly decreased when exposure to 0.4, 0.6, and 0.8 mg L−1 MET . Transcription level of 3β-HSD was downregulated by 2-fold in the 0.4 mg/L group (p < 0.05), 0.6-fold in the 0.6 mg L−1 group (p < 0.05) and 0.7-fold in the 0.8 mg L−1 group (p < 0.05).As shown in esr1, esr2a, and esr2b were downregulated in all exposure groups . While under the influence of high concentration of MET (0.8 mg L−1), the expression of the receptor genes esr1, esr2a, and esr2b was recovered compared to other treatment groups.As shown in Dmrt1 expression decreased by about 0.7-fold in the 0.2 and 0.4 mg L−1 group (p < 0.05), and 0.6-fold in the 0.6 mg L−1 group (p < 0.05). foxl3 was downregulated in all exposure groups (by about 2.5- to 3.3- folds). Expression level of JNK1 was slightly increased after exposure to MET (by about 1.2- to 1.3- folds).As shown in M. albus was observed at high concentration of MET exposure (Vitellogenin (VTG), the precursor of yolk proteins, is produced after estrogen combine with specific Estrogen receptors (ESRs) in the liver, while VTG is absent or present at very low concentration in male and juvenile fish . It has exposure , while nM. albus showed no significant change under the influence of MET   , chemicapression . Howeverequences , which rent fish . In the tebrates , is fountebrates . In thisFSHβ and LHβ genes. Negative feedback of sex steroid on gonadotropin mainly includes two: one is reducing the content of gonadotropin releasing hormone (GnRH) receptor on the pituitary to reduce the regulation from GnRH  and luteinizing hormone (LH) are secreted by the pituitary and act by binding to specific receptor  in gonad, which are the primary mediators of signals to induce steroidogenesis and gametogenesis . FSH androm GnRH , the othrom GnRH . In our in vitro . This inokinawae  and Epinus merra . Zhang ee plasma . Thus, tHSD11b2) and 3β-hydroxysteroid dehydrogenase (3β-HSD) are involved in androgen synthesis, which are considered to play an important role in masculinity (HSD11b2 and 3β-HSD expression decreased significantly after MET exposure. Androgen synthesis genes can be suppressed by estrogen-like chemicals, which has been reported in odontesthes bonariensis (Oncorhynchus mykiss (Salmo salar (. The results of the present study were similar to these previous results, which further demonstrate that MET may have estrogenic potency. However, unlike previous studies, plasma T levels did not decrease due to the decreased expression levels of androgen synthesis genes. One explanation for this phenomenon is that production of steroids is a complex process with multiple sensitive control points, so the genes within the steroidogenesis pathway are not transcribed to the same extent and have no simple linear relationship with hormone production. However, whether this reduction in the expression of genes associated with sex steroid levels inhibits the reversal of female M. albus to males requires further investigation.In teleost, the type 2, 11β-hydroxysteroid dehydrogenase (culinity . In the ariensis , Oncorhys mykiss  and Salmmo salar . The resESRs are usually closely related to hormone levels (esr1, esr2a and esr2b in liver decreased to varying degrees, and the expression of ESRs was inconsistent with hormone levels. Previous study demonstrated that basal ESRs levels might be enough to initiate oogenic protein genes (ESRs levels are depleted, transcriptional machinery is activated to regulate the synthesis of oogenesis protein genes (ESRs are decreased under the MET exposure, the levels of transcriptionally generated ESRs still meet the requirements for regulating vitellogenin production. In addition, ESRs are also thought to play a role in sex differentiation due to their involvement in sex steroid signaling (M. albus by inhibiting this mether of oocytes.ESRs are ligand-activated transcription factor that interacts with the response elements in the target gene promoter to activate or inhibit transcription . Both ese levels . The prein genes . When bain genes . This suignaling . Currentignaling . HoweverDmrt1, Foxl3 and JNK1 have been studied. In the present study, the expression of Dmrt1 was inhibited under MET exposure, which is similar to the result of the effect of estrogen compounds on other teleosts (Dmrt1 control the formation, development and maintenance of male reproductive organs (Foxl3 and JNK1 were considered to play a role in sex reversal in M. albus, Foxl3 is thought to promote oocyte degeneration and spermatogenesis, while JNK1 may be important for oocyte growth and differentiation (foxl3 and non-significant upregulation of JNK1 at all MET concentrations may mean that spermatogenesis is inhibited and oocyte development is promoted after MET exposure. This indicates that MET acts more like an estrogen, inhibiting testis development but promoting oocyte development.To further understand the possible impact of MET on sex reversal, the expressions of sex-related genes teleosts . Dmrt1 ce organs . The resntiation . In the M. albus. MET can directly affect the expression of genes on the HPG axis without affecting the level of sex hormones. The exposure of MET increased the expression of CYP19A1b and CYP17, which regulate sex hormone production in the brain, but all genes related to sex hormone secretion in the ovary were suppressed. Furthermore, sex-associated genes did not show a trend of sex reversal after MET influence.The present study shows that MET has estrogenic effects with perturbance on female


Umingmakstrongylus pallikuukensis, which varied depending on the geographical location; and (vi) no association between qiviut cortisol and other pathogen exposure/infection intensity metrics. This study confirmed and further identified important sources of variability in qiviut cortisol levels, while providing important insights on the relationship between GC levels and pathogen exposure/infection intensity. Results support the use of qiviut cortisol as a tool to monitor temporal changes in HPA axis activity at a population level and to inform management and conservation actions.Glucocorticoid (GC) levels are increasingly and widely used as biomarkers of hypothalamic–pituitary–adrenal (HPA) axis activity to study the effects of environmental changes and other perturbations on wildlife individuals and populations. However, identifying the intrinsic and extrinsic factors that influence GC levels is a key step in endocrinology studies to ensure accurate interpretation of GC responses. In muskoxen, qiviut (fine woolly undercoat hair) cortisol concentration is an integrative biomarker of HPA axis activity over the course of the hair’s growth. We gathered data from 219 wild muskoxen harvested in the Canadian Arctic between October 2015 and May 2019. We examined the relationship between qiviut cortisol and various intrinsic  and extrinsic biotic factors , as well as broader non-specific landscape and temporal features . A Bayesian approach, which allows for the joint estimation of missing values in the data and model parameters estimates, was applied for the statistical analyses. The main findings include the following: (i) higher qiviut cortisol levels in males than in females; (ii) inter-annual variations; (iii) higher qiviut cortisol levels in a declining population compared to a stable population; (iv) a negative association between qiviut cortisol and marrow fat percentage; (v) a relationship between qiviut cortisol and the infection intensity of the lungworm  Hair cortisol, an indicator of stress, varied among years, sex and geographical location in wild muskoxen and was associated with poorer body condition and lungworms. These results support use of hair cortisol as a tool for monitoring muskox health and informing management.</p></sec>Climate warming and other anthropogenic changes are occurring at an unprecedented pace worldwide. Understanding the effects that these changes and their associated stressors have on wildlife species is essential for biodiversity conservation . This isOvibos moschatus), an iconic Arctic ungulate species, are essential for the nutrition, economy and culture of local Indigenous communities  and expanding lungworm infections  axis, which leads to the release of glucocorticoids (GCs)  of muskoxen can be used as a biomarker of HPA axis activity during the period of the hair’s growth . Samples were obtained under the Wildlife Research Permit #2016-058 for Nunavut (NU) and the Wildlife Research Permits #WL500257, WL5004469 and WL500664 for the Northwest Territories (NWT).Samples from 219 muskoxen, harvested as part of a community-based muskox health surveillance program in Ekaluktutiak and Kugluktuk, NU, and in Ulukhaktok, NWT, were obtained between October 2015 and May 2019 . The surHunters and guides collected samples using standardized kits available to them at the local wildlife office and/or Hunters and Trappers Organization/Committee. Participation in this program was voluntary and they received financial compensation for each completed kit. Kits were modified from those described by Samples were classified to two different seasons based on their collection date: late fall–early winter (last week of September to end of December) and mid-winter–late winter (January to mid-May). There was a large overlap between the growth periods of some of the late fall-early winter and mid-winter–late winter qiviut samples, as qiviut grows approximately from early April to late November with no growth observed between mid-December and March . HoweverWhen left blank or indicated as ‘unknown’ on the information sheet, the sex of the muskox was determined using genetic analyses as previously detailed by Umingmakstrongylus pallikuukensis (Up) or Varestrongylus eleguneniensis (Ve) based on their caudal morphology following the keys developed by Approximately 5 g from each faecal sample was weighed (as little as 2 g were used if the amount was limited) and analysed using the modified beaker Baermann technique for the presence of protostrongylid lungworm first stage larvae (L1) . ModificNematodirus spp. and Nematodirella spp.), Marshallagia marshallagi, Eimeria spp. or Moniezia spp.) based on their morphological characteristics. The eggs of Teladorsagia boreoarcticus and Ostertagia gruehneri, two major GI parasites of muskoxen, were not counted as egg production occurs mainly throughout the summer  from each faecal sample was weighed and evaluated for the presence of GI parasite eggs and oocysts using the modified Wisconsin double-centrifugation sugar flotation technique . ModificMoniezia spp. as explained above). The correlations between the number of adult worms in the lungs or GI tract and the amount of L1, eggs or oocysts shed in the faeces have not been investigated in muskoxen. However, a study in Svalbard reindeer (Rangifer tarandus platyrhynchus) showed that faecal egg counts were positively associated with adult worm burden for M. marshalli  and species or groups (GI parasites) infecting each muskox.For each animal, qiviut, intermediate hairs and guard hairs from an area free from obvious blood or other contamination were cut away from the skin using a scalpel blade. Qiviut was manually separated from guard and intermediate hairs using forceps and was divided into two subsamples of 0.05 g, which were independently analysed. Qiviut cortisol analyses were done at the Endocrinology Laboratory of the Toronto Zoo following the procedure detailed in Filter paper sets were removed from the freezer and air-dried at room temperature for at least 24 h. They were then eluted following the method described by E. rhusiopathiae with a modified enzyme-linked immunosorbent assay (ELISA) (sample − ODblank)/(ODcont − ODblank) × 100, with ODsample corresponding to the optic density (OD) value measured for the sample, ODcont to the OD value of the positive control, and ODblank to the OD value of the ELISA plate’s blank well (Eluates were tested for antibodies against Brucella using two different indirect enzyme-linked immunoassays (i-ELISA). All samples from hair growth year 2015 (n = 28) were analysed at the Arctic University of Norway, Research Group for Arctic Infection Biology  were analysed at the Canadian Food Inspection Agency National Brucellosis Reference Laboratory  Network (2008), except marrow samples were dried at room temperature instead of in an oven . The perLower jaws were assessed for incisor breakage (both permanent and deciduous). The incisor breakage score was calculated as number of incisors broken/number of incisors examined.Back_fat and incisor_breakage were not included in the original modelling procedure as >25% of records for these variables were missing. The effects of these two variables and their corresponding interactions on qiviut cortisol were later assessed using the subset of animals for which they had been recorded by adding them into the final model.The effects of the different intrinsic , extrinsic abiotic  and extrinsic biotic  factors  on qivius) as these variables were not normally distributed , as well as some others that did not substantially improve the DIC, but for which there was suggestive evidence that they had an ‘important’ effect . From that ‘stage 2’ model, we proceeded through manual backward elimination to simplify the model and sequentially removed the variables or group of variables (i.e. GI parasite egg/oocyst counts) that did not appear to have an ‘important’ effect on qiviut cortisol when considering their 95% CrI. With each removal, the impact on the DIC  were considered not infected and assigned a count of zero. We assumed that the response variable, qiviut cortisol, followed a gamma distribution as its values were positive and right-skewed, and Up_lpg was rescaled using a square-root (sqrt) transformation for better model fit.We considered our missing data as missing at random and consequently the missing data mechanism as ‘ignorable’  . For allParallel Markov chain Monte Carlo (MCMC) chains were run with 900 000 iterations per chain, a burn-in period of 10 000 iterations and thinning of 1000. Results reported here were based on two chains, whereas two additional chains were run  for model diagnostics. Marginal posterior distributions and the parameter trace plots were examined to check the convergence of the chains. Mixing of the chains was assessed visually using the MCMC trace plots for each parameter  and the rjags version 4-10 and coda version 0.19-4 packages were used for Bayesian data analysis and diagnostics . However, we included both Up_lpg and Ve_lpg in the model selection process for research purposes as the two lungworms differ in their life history characteristics , morphology and pathology , as well as the interactions between location and sqrt(Up_lpg) and between sex and season.When assessing the two-by-two correlations between variables, we found a fairly high correlation only between sex and season, with males having lower qiviut cortisol levels in mid-winter–late winter than in late fall–early winter, whereas females had similar qiviut cortisol levels during the two seasons , whereas it was 72.4% on Victoria Island. Infection intensity also varied across sites: it was very low on Victoria Island  and the east mainland , and much higher on the west mainland  , incisor breakage score (n = 152) and their corresponding interactions had no effect on qiviut cortisol (results not shown).When added to the final model, back fat thickness  and relationships between hair GCs and metrics of health (i.e. body condition and pathogen exposure/infection intensity metrics), as well as interactions between geographical location and et al., in press). Sex differences in HCCs could also be an artefact of hair growth patterns and fibre morphological characteristics, which may influence cortisol incorporation into hair . The rut is characterized by reduced nutritional intake and repeated and prolonged aggressive interactions with male counterparts, along with courtship behaviours, which are all highly energetically demanding , but may also be linked to the lower stress experienced after the rut, which may dilute the qiviut cortisol levels, although lower qiviut growth occurs after September. Female qiviut cortisol levels did not differ between the two seasons. Based on the qiviut growth cycle, approximately April–November, qiviut cortisol levels may have been affected by parturition, lactation and early pregnancy. These reproductive status data were not available, thus we were unable to assess their influence.Qiviut cortisol levels were higher in males than in females, consistent with previous findings in wild muskoxen (nto hair . IncreasOdocoileus virginianus) and red deer (Cervus elaphus), HCCs did not vary significantly among fawns, yearlings and adults (>2 years)  and Rocky Mountain goats (Oreamnos americanus) . Differences in qiviut cortisol among geographical locations may reflect variations in biotic and abiotic environmental characteristics. Kugluktuk area is located in a different Bioclimate Subzone from Kent Peninsula and Victoria Island .Qiviut cortisol levels varied among geographical locations. They were lowest in the stable muskox population from the west mainland , higher in the declining Victoria Island population and highest on the east mainland  (Lepus americanus) and rhesus monkeys (Macaca mulatta), in which higher HCCs were associated with increased predation risk and population density, respectively . The impact of some of these factors on GC levels has previously been highlighted in other wildlife species . S.K. was supported by grants from Polar Knowledge Canada [Grant NST-1718-0015], NSERC [Discovery Grant RGPIN/04171-2014 and Northern Supplement RGPNS/316244-2014], ArcticNet, Canada North Outfitting and the Shikar Foundation.The data underlying this article will be shared on reasonable request to the corresponding author.supplementary_coab103Click here for additional data file.


The durability of reinforced concrete (RC) beams strengthened with carbon fiber-reinforced polymer (CFRP) is a worldwide concern in structural engineering. As an important part of the strengthened beam, the performance of the CFRP–concrete interface under hygrothermal environments is a delicate problem. In this paper, the fatigue behavior of CFRP-strengthened RC beams is analyzed by a theoretical model. In the model, CFRP–concrete interface degradation under hygrothermal environments is involved. Since interface debonding and rebar fracture induced by intermediate cracking are two typical failure modes, the damage models of rebar and the CFRP–concrete interface are established. Based on the theoretical model, the failure mode of CFRP-strengthened RC beams can be predicted, and fatigue life can be determined. The results showed that IC debonding is more likely to occur under hygrothermal environments. The accurate prediction of failure modes is essential for fatigue life prediction. Existing reinforced concrete (RC) structures have become weak and dilapidated due to various factors, including vehicle growth, population explosion, and extreme environmental erosion. Fiber-reinforced polymer (FRP) composites have high tensile strength, low self-weight, and good corrosion resistance and have been extensively used to strengthen and rehabilitate RC bridge structures over the past decades ,2,3.There are considerable studies on the static behavior of FRP-strengthened RC beams ,5,6. In The interfacial behavior of the FRP–concrete interface under monotonic loading has been investigated ,12,13, aBridges are serviced in various extreme environments, such as salt spray , hot andFinally, it is necessary to take into consideration the coupling effect of fatigue load and hygrothermal conditions on fatigue behavior of FRP-strengthened RC beams. Based on Huang’s results , Qin 3434 establWith a focus on the durability of CFRP-strengthened RC beams, a theoretical model considering the degradation of the CFRP–concrete interface under hygrothermal environments was proposed. With this model, the accumulated damage of strengthened beams with intermediate flexural crack was analyzed. According to the analysis, two main failure modes were considered: IC debonding and rebar fracture caused by the intermediate crack. Moreover, two corresponding failure criteria were established. The proposed theoretical model and calculation procedure can be used to predict the failure mode of strengthened beams and determine the fatigue life under hygrothermal environments.During the fatigue process, the properties of RC beams degrade because of the concrete cumulative damage. RC beams are vulnerable to cracking because of the low tensile strength of concrete. In the preliminary studies of this research group ,34,35, aSeveral model types are suitable for the description of the interfacial bond–slip relationship, such as the bilinear, cutoff, elastic–plastic, and Popovics models . BecauseTo study the influence of humidity and temperature variations on CFRP–concrete interface degradation, Zheng  conducteciE at the ith cycle degrades because of cumulative damage [in is the cycle number; cE is the initial elastic modulus; and ciN is the fatigue life corresponding to compressive stress, which can be calculated by [ciS is the ratio of the compressive stress cf at the ith cycle.Because of its perfect fatigue resistance, CFRP has been considered a kind of linear elastic material in the whole fatigue process, but the concrete effective modulus e damage , which ce damage :(2)Eci=(lated by :(3)Sci=0The main rebar in this paper is assumed to be elastoplastic. The rebar keeps linear elasticity before yielding, and when the tensile stress i increases, the degradation in concrete elastic modulus ai0, the neutral axis location chi0, and the curvature ρi0. Assuming that the cross-section strain is linear, M is the flexural moment; pb and b are the width of the CFRP and the beam, respectively; sA and s′A are the cross-section areas of tension- and compression-rebar, respectively; h is the height of the RC beam; c is the concrete cover thickness; pt is the thickness of the CFRP; and pE, cE, and s′E are the elastic moduli of the CFRP, concrete in tension, and rebar in compression, respectively.In Equation (4), the first derivative of the interface slips at mid-span Since the behavior of the CFRP–concrete interface is different in the elastic and softening phases, the interfacial slip and stress should be discussed separately. During the elastic stage, the interfacial stress essed as :(6)si(x)Once B and C are constants which can be determined by boundary and continuous conditions [nditions .At the tip of the intermediate crack, the tensile stress of concrete reaches uniaxial tensile strength sE is the elastic modulus; ith cycle, which can be given by:Because the tensile rebar is considered ideal elastoplastic, the expression of the tensile stress ia, the neutral axis height chi0, and the curvature ith cycle, the deflection vi0 at mid-span can be expressed as:From the Equations (4)–(10), the intermediate crack length Fatigue tests on CFRP-strengthened RC beams have been carried out in preliminary research ,41,42. RS–N relationship [siS is the amplitude of applied tensile stress in MPa and iN is the fatigue life of rebar corresponding to siS.As described in tionship  of rebarin is the cycle number of rebar at the stress amplitude By using Miner’s rule, the cumulative damage of rebar Based on Equations (9) and (10), The debonding failure of strengthened RC beams can be divided into two types: intermediate crack (IC) failure and plate end (PE) failure. Due to the existence of strain difference at the CFRP end, PE failure occurs after the separation of CFRP from concrete. Meanwhile, IC debonding failure initiates from the intermediate crack at the mid-span of the beam; this is because the higher interfacial shear stress is around the intermediate crack .PE debonding failure needs to be considered when there is no intermediate crack. To avoid such a debonding failure, it is effective to anchor the end of the CFRP. However, flexural cracks always appear at the mid-span of strengthened RC beams, which increases the possibility of IC debonding failure. Thus, IC debonding failure needs to be involved in this study.The energy release rate in the CFRP–concrete interface under the flexural moment essed as :(14)GR=1P is the external load; In Equation (15), the changing rate of the work performed by external force is:The changing rate of dissipated energy If Based on the prediction model, the fatigue life of CFRP-strengthened RC beams can be calculated. The dimensions and material parameters of the strengthened beam are inputted into the theoretical model.The bond–slip relationships under different environments and fatigue loads are inputted into the theoretical model.The peak and valley values of cyclic loads are inputted into the theoretical model. From the previous step, the degraded elastic modulus and compression stress of concrete can be obtained by Equations (2) and (3). The parameters of the concrete after degradation are entered in the next step.The curvature ach step .i will be the predicted fatigue life.In each step, the cumulative damage to rebar Ds  can be oThe shear stress distribution can be obtained . When thFrom the theory involved in i will be the predicted fatigue life.If As long as either one of the cumulative damages, To verify the effect of the hygrothermal environment on strengthened beams’ fatigue performance, numerical examples for strengthened beams were proposed. At a constant relative humidity of 95%, temperatures varied from 5 °C to 80 °C. Then, the distribution of interfacial stress and failure mode changed accordingly. The predicted fatigue lives corresponding to each failure mode were calculated.The major parameters of bond–slip relationships with and without hygrothermal pretreatments are listed in  27.5 kN a, the co 27.5 kN b, the coBased on the calculation procedure, the tensile stress and cumulative damage of rebar Under the same loading level, the CFRP tensile stress increases with the temperature increase. At the loading level of 27.5 kN, the tensile stress of CFRP at 80 °C, 95% R·H increased by 33% compared with that at 5 °C, 95% R·H. When the loading level was 30 kN, the tensile stress of CFRP at 80 °C, 95% R·H increased by 21% compared with that at 5 °C, 95% R·H when bD reaches 1. In x = 0. The length from the mid-span with an interfacial shear stress of 0 is the debonding length and denoted by bD reaches 1, and so the interfacial shear stresses beyond 200 mm have not been plotted.Based on the calculation procedure, the shear stress distribution sD = 1 and bD = 1, are listed in With the comparison between the cumulative damages of rebar and the CFRP–concrete interface, the failure mode of the strengthened beam can be determined. The predicted failure modes and predicted lives of all specimens, corresponding to bD = 1 decreased obviously with the increase in temperature. sD reached 1 before bD at 5 °C, 95% R·H, which means that the corresponding failure mode was rebar rupture. However, when the temperature reached 20 °C or above at 95% R·H, bD reached 1 first, and the corresponding failure mode was IC debonding. In the case of a strengthened beam tested under a loading level of 30.0 kN, two failure modes (rebar fracture and IC debonding) occur simultaneously at 5 °C, 95% R·H. bD reached 1 first under other environments, and the corresponding failure mode was IC debonding. The research results show that CFRP-strengthened RC beams subjected to fatigue loading with a high loading level are more likely to fail with IC debonding under hygrothermal environments.For a strengthened beam under a loading level of 27.5 kN, the cycle number when Fatigue tests were conducted on the CFRP-strengthened RC beams to verify the proposed theoretical model and calculation procedure. The three-point bending fatigue tests were performed with a MTS-810 testing system. During the fatigue tests, the force-control mode with sine wave was adopted. In addition, the loading frequency was set at 10 Hz, while the stress ratio was 0.2. All RC beams were prepared in accordance with the code of practice. The material parameters and configuration of the CFRP-strengthened RC beam are listed in Pmax was set at 27.5 kN (66% of A total of 26 specimens were prepared and divided into eight groups, which were subjected to different loading levels and hygrothermal environments. Before carrying out the fatigue tests, each group of specimens was exposed to simulated environments for 14 days at 5 °C, 95% R·H; 20 °C, 95% R·H; 50 °C, 95% R·H; and 80 °C, 95% R·H, respectively. According to a preliminary study of this group , the staTypical failure modes are shown in 6 are treated as 2 × 106. Although the fatigue lives at a loading level of 27.5 kN are dispersed because of individual differences, the average lives match well with the predicted results. The maximum relative error is 19.2% compared with the average test results. For the fatigue lives at a loading level of 30 kN, the relative error is 4.2% in the case of IC debonding failure. However, there is a large relative error of 63% in the case of rebar rupture. Therefore, the failure of IC debonding should be taken into consideration when CFRP-strengthened RC beams are subjected to high-level fatigue loads.According to the proposed theoretical model, it is possible to predict the fatigue life of strengthened beams subjected to different loading and environmental conditions. Both the tested and predicted lives are shown in A fatigue life prediction model for CFRP-strengthened RC beams under hygrothermal environments was proposed, with consideration of the interfacial characters of CFRP–concrete. Corresponding failure criteria for rebar fracture and IC debonding were established. The proposed model can be used to analyze the fatigue behavior of strengthened beams and provide a scientific basis for life evaluation and retrofit design of RC bridges. The following conclusions have been drawn:Flexural concrete cracks grew rapidly and remained stable, while the main crack at the mid-span section continued to propagate and caused damage accumulated in rebars. The performance of concrete and the CFRP–concrete interface degraded under fatigue loads and hygrothermal conditions, leading to increases in crack length and deflection.The behavior of the CFRP–concrete interface degraded significantly under hygrothermal environments. When the strengthened beam was subjected to low-temperature conditions, the test failure mode was rebar rupture, which agreed with the model prediction. In the case of high-temperature conditions, the failure mode changed to IC debonding, which was also successfully predicted.The interfacial shear stress exhibited a large increase under a high loading level, leading to IC debonding failure. The accuracy of fatigue life prediction was enhanced with the consideration of failure modes.Fatigue life prediction matched the average test results well, but there were errors caused by specimen discreteness. Further research will be focused on FEM simulation, which will be helpful for improving the proposed model.


Anti‐obesity medications act by suppressing energy intake (EI), promoting energy expenditure (EE), or both. Metformin (Met) and mirabegron (Mir) cause weight loss by targeting EI and EE, respectively. However, anti‐obesity effects during concurrent use of both have yet to be explored. In this study, we investigated the anti‐obesity effects, metabolic benefits, and underlying mechanisms of Met/Mir combination therapy in two clinically relevant contexts: the prevention model and the treatment model. In the prevention model, Met/Mir caused further 12% and 14% reductions in body weight (BW) gain induced by a high‐fat diet compared to Met or Mir alone, respectively. In the treatment model, Met/Mir additively promoted 17% BW loss in diet‐induced obese mice, which was 13% and 6% greater than Met and Mir alone, respectively. Additionally, Met/Mir improved glucose tolerance and insulin sensitivity. These benefits of Met/Mir were associated with increased EE, activated brown adipose tissue thermogenesis, and white adipose tissue browning. Significantly, Met/Mir did not cause cardiovascular dysfunction in either model. Together, the combination of Met and Mir could be a promising approach for the prevention and treatment of obesity by targeting both EI and EE simultaneously. The combined metformin/mirabegron treatment not only prevents the development of diet‐induced obesity but also promotes weight loss in established diet‐induced obesity. Furthermore, metformin/mirabegron treatment induces a greater reduction in body weight than either treatment when used alone. Mechanistically, these benefits on weight loss were mainly achieved by activating brown adipose tissue thermogenesis and promoting subcutaneous white adipose tissue browning, leading to enhanced energy expenditure. BAT is enriched with mitochondria in which uncoupling protein 1 (UCP1) is highly expressed. UCP1 dissipates excess energy as heat in a process known as thermogenesis.In this study, we used Met as an EI suppressant and Mir as an EE booster to investigate the combined effects of Met/Mir in preventing obesity development as well as in treating established DIO in mice. We measured several metabolic parameters and investigated the underlying molecular mechanisms, with a special focus on pathways involved in thermogenesis. We also evaluated the safety of this combination treatment, especially on potential cardiovascular side effects. Our results showed that Met/Mir produced additive effects on the prevention and treatment of obesity compared with monotherapy with either drug, with minimal side effects observed.22.1Mice were fed a HFD and simultaneously received daily gavage with vehicle (Veh), Met, Mir, or Met/Mir for 12 weeks Figure . The bodNext, we measured the body composition using nuclear magnetic resonance (NMR) Figure . No drug2.2Since obesity occurs under a long‐term energy imbalance, we next evaluated the effects of Met/Mir on EI and EE. Consistent with previous reports,2 consumption, CO2 release, and EE when data were expressed as an hourly average and as a 12‐ or 24‐h average post‐drug administration   Figure . No effe) Figure . Additio) Figure . Collect2.4Ucp1 mRNA expression, while Met/Mir significantly upregulated its expression , while Mir and Met/Mir significantly reduced total WAT weight by 43% (–2.05 g) and 63% (–2.96 g), respectively  aims to investigate the association between the gut microbiome and Mir metabolism. The exact mechanism by which Met/Mir improves glucose homeostasis remains an interesting new topic warranting future investigation.This study confirmed that both Met and Mir monotherapy improve glucose tolerance, yet no further enhancement was observed under combined Met/Mir treatment in either of our models. Noticeably, however, Met/Mir additively improved insulin responsiveness under obesogenic conditions, contributing to the protective effect against HFD‐induced weight gain in the prevention model. This superior improvement in insulin responsiveness compared to monotherapy may be attributed to the greater reduction in adiposity that Met/Mir produced, subsequently resulting in improved glucose homeostasis. However, Met/Mir may also have other mechanisms to modulate insulin responsiveness that may explain this additive effect. Met has been found to improve insulin sensitivity via the AMP‐activated protein kinase pathway.Considering that the majority of anti‐obesity pharmacotherapies failed to reach the market due to unwanted side effects as opposed to poor efficacy, it was crucial to evaluate the potential adverse effects of Met/Mir therapy. Mir has been associated with adverse cardiovascular effects4This study is the first to demonstrate that a combination of Met and Mir has an additive effect on preventing and treating obesity, with measurable improvements in glucose homeostasis and minimal adverse effects. Our findings provide a novel route to managing obesity where both EI and EE can be modulated using pre‐existing drugs. From a clinical perspective, this research will provide critical preclinical evidence for future clinical trials in humans.55.1Male 8‐week‐old C57BL/6J mice were purchased from Vital River Laboratory Animal Technology Co., Ltd. . Mice were housed in a specific pathogen‐free animal facility at a standard 12‐h light/12‐h dark cycle with ad libitum access to water and food unless stated otherwise. Mice were acclimatized to the environment for 1 week before the experiments.5.2initial)/BWinitial × 100%.Forty‐eight mice  were divided into four groups based on BW. They were fed a HFD  and concurrently received daily gavage with either Met , Mir , Met/Mir (250/10 mg/kg/day) or Veh at 5:00 p.m. for 12 weeks. The chosen dosages of Met and Mir were based on the previous literature.5.3Mice  were first fed a HFD for 9 weeks to establish a DIO phenotype. Then, 56 DIO mice with an average BW of 41.1 ± 2.3 g (mean ± SD) were divided into four groups based on BW and received daily oral gavage with Veh, Met, Mir, or Met/Mir as described above for five continuous weeks. BW was monitored daily at a fixed time of the day, and BW change was calculated as described above.5.4Spontaneous food and water intake were measured after the mice had acclimatized to a single cage for 24 h with ad libitum access to water and food.5.5Intraperitoneal glucose tolerance tests (IPGTTs) and insulin tolerance tests (ITTs) were performed as previously reported.5.62 release, and ambulatory activity were monitored for 24 h as previously described.Mice were acclimatized to Promethion Metabolic Systems  for 24 h. Then, oxygen consumption, CO5.7A cohort of 24 male mice  was divided into four groups and single housed. The mice received the same amount of HFD based on the food intake of the Met‐treated animals on the previous day, and concurrently received daily gavage of Veh, Met, Mir, or Met/Mir for 2 weeks. Blood glucose levels were measured at 9:00 a.m., both before and after drug administration with HFD pair‐feeding. Mice were fasted for 6 h before performing IPGTT and ITT at 8 and 10 days, respectively, after the commencement of treatments.5.8The body composition of mice was determined using an animal NMR system  at the end of the experiment.5.9The total RNA of adipose tissues was extracted by TRIzol . RNA (1000 ng) was reverse‐transcribed using a Primerscript RT Reagent Kit (Takara). Real‐time PCR was performed using TB Green Premix Ex Taq II (Takara). The CT value of each gene product was normalized to the housekeeping gene 18S ribosomal RNA (Rn18s).5.10Proteins were extracted from adipose tissue by using RIPA lysis buffer containing a protease/phosphatase inhibitor cocktail (Roche). Western blotting was performed following a standard protocol. The antibodies are shown in Table 5.11*p < 0.05, **p < 0.01, and ***p < 0.001.Statistical analyses were performed using GraphPad Prism 9.0 software  based on the design of each experiment and are indicated in each figure legend. The data are presented as mean ± standard error of mean. ns, not significant, Q.P.W. and X.Y.Z. conceived and designed the project, drafted the original manuscript, and reviewed and edited the manuscript. X.Y.Z. and Y.L. performed the majority of experiments and analyzed and interpreted the data. X.Z. contributed to data analysis and interpretation, conducted pair‐feeding‐related experiments, and revised and edited the manuscript. B.C.Z., Z.C.Y., Y.L., A.Q.L., R.X.Z., and Z.Y.L. performed part of the animal work and molecular biology experiments. G.B. reviewed and edited the manuscript. Y.C.S. provided critical guidance for the experimental design, interpreted data, acquired funding, and reviewed, revised, and finalized the manuscript. Q.P.W. oversaw the project, acquired funding, and finalized the manuscript. All authors read and approved the final manuscript.The authors declare they have no conflicts of interest.All animal procedures were performed following standards approved by the Sun Yat‐sen University Committee on Ethics for the Use of Laboratory Animals following the Animal Welfare Legislation of China (Ethics No. SYSU‐IACUC‐2020‐000165) and the Garvan Institute/St. Vincent's Hospital Animal Ethics Committee (Ethics #19_25), Australia.Supporting InformationClick here for additional data file.


Antibiotic resistance is a major global public health problem. The primary cause of antibiotic resistance is inappropriate antibiotic use. In this study, we aimed to verify whether the monthly evaluation of antibiotic prescription improves clinical antibiotic use in outpatient and emergency departments.A minimum of 25% of the prescriptions for antibacterial drugs were randomly selected at the outpatient and emergency departments to enter the monthly evaluation system from July 2016 to June 2019. We analysed the rate of irrational prescription of antibiotics, proportion of the use of antibiotics, and consistency between the evaluation and expert groups after implementing the monthly assessment to validate the role of monthly evaluations.After 3 years of monthly evaluations of antibiotic prescriptions, the utilisation rate of single antibiotics in the outpatient and emergency departments was found to increase each year. Each year, a decreasing trend was observed for the irrational use of antibiotics, whereas the proportion of antibiotics to the total drugs prescribed gradually decreased in the same period. In addition, the consistency of prescription evaluation results between the evaluation and expert groups increased continuously.Monthly evaluation of antibiotic prescriptions is an effective management tool for the rational use of antibiotics in clinical practice. This practice could help reduce the combinative use of antibiotics, rate of irrational antibiotic prescription, and antibiotic use ratio, and play an important role in safe clinical drug use. Since the 1940s, an increasing number of antibiotics have been developed for human use. Antibiotics have saved countless lives in clinical practice, and they are among the most commonly prescribed drugs in human medicine . AntibioThe primary cause of antibiotic resistance is the inappropriate use of antibiotics. Accordingly, it is necessary to reduce the excessive rate of antibiotic prescription and improve the use of antimicrobials to curb resistance . PerformA total of 58 749 antibiotic prescriptions from the outpatient and emergency departments were randomly selected from the Ningbo No. 6  Hospital from July 2016 to June 2019.Drug descriptionPrescribing point review management practices , 2010, China [0, China Scheme of special remediation activity on the clinical application of antimicrobial drugs, 2012, China [2, China Guidelines for clinical use of antimicrobial agents, 2015, China [Clinical guidelinesUpToDate database .The appropriateness of prescription was evaluated based on the following documents and database.We first enabled the IPharmacare Drug Management System . The IPharmacare Drug Management System is established by IPharmacare . The system is used for hospital drug management, including drug approval, prescription restrictions, and random sampling of prescriptions. Every month, 25% of the doctors in our hospital with the right to prescribe antibiotics were randomly selected by this system to evaluate the antibiotics prescribed in the outpatient and emergency departments. Among the doctors selected by the system, if a doctor had made more than 50 prescriptions, we drew 50 prescriptions, and if a doctor had made than 50 prescriptions, we evaluated all prescriptions. An additional parameter was that the number of prescriptions should not be less than 25% of the total prescribed in the hospital.a scheme of special remediation activity for the clinical application of antimicrobial drugs, 2012, China [.The above selection ratio and quantity are based on 2, China .Prescription evaluation teams were established under the leadership of the Medical Services section and consisted of working groups and expert group members. The evaluation team consisted of six clinical pharmacists who conducted an initial evaluation of randomly selected prescriptions, and the expert group consisted of two chief pharmacists and two chief physicians who conducted a re-evaluation of irrationally prescribed antibiotics. For the initial evaluation, the clinical pharmacists assessed sample prescriptions, and prescriptions of antibiotics prescribed irrationally were recorded using Microsoft Excel (2010) spreadsheets. Irrational prescription types, problem descriptions, medication suggestions, and other parameters were then analysed.Next, the prescription evaluation team leader re-evaluated any unreasonable prescriptions, which were then publicised on the hospital intranet for 1 week. The prescription evaluation team leader was contacted for any issues, and experts were organised to re-evaluate the problem to obtain the final evaluation result.The sampling and preliminary evaluation of the previous month were completed before the 15th of each month. The evaluation results were publicised and studied by the entire hospital staff on the 15th of each month. If there were any objections within 7 days, the expert group would start the re-evaluation; otherwise, the evaluation result remained in effect.Unreasonable prescriptions were publicised regularly, and the final result was included in evaluating individual senior professional titles. Every doctor has a benchmark score of 100 each year. For each unqualified prescription, 0.1 point was deducted from the benchmark score. The result of applying for a senior professional position and the income of a doctor were related to the score.P < 0.05 were considered statistically significant. The irrational prescription rates of antibacterial drugs in different years were analysed using the chi-square test.SPSS version 16.0  was used for data processing, and results with After implementing the monthly evaluation system, the rate of single antibiotic prescriptions in the outpatient departments increased each year from July 2016 to June 2019; the rate of single antibiotic prescriptions in the outpatient and emergency departments increased by 3.53 and 2.99 percentage points, respectively. In addition, the rate of combined prescriptions of two antibiotics decreased with time. Notably, the prescription rate in the emergency department was always higher than that in the outpatient department each year. In 2018 and 2019, the rate of triple antibiotic prescriptions was 0.00% (Table An important aspect of the monthly evaluation system was notification to the relevant physician and publication of why the prescription was classified as unreasonable. The effect of this measure was directly reflected in the decrease in the proportion of irrational prescriptions. From July 2016 to June 2019, the rate of irrational prescriptions showed a significant downward trend. The irrationality rate in 2019 decreased by 1.6 percentage points compared with the rate in July–December 2016 Table .Table 3RThese irrational prescriptions consist of four categories of problems: irrational antibiotic combined therapy, irrational usage and dosage, medications not matching the diagnosis, and no indication of antibiotics. From July 2016 to June 2019, the main problem of irrational prescription gradually shifted from irrational usage and dosage to no indication of antibiotics Table .Table 4PConsidering the possibility of misevaluation by the evaluation team, a reassessment system and feedback channel were incorporated into the evaluation system. The number of unqualified prescriptions obtained in each expert group reassessment and the number of unqualified prescriptions obtained in the initial evaluations by clinical pharmacists were summarised to determine the consistency of prescription evaluation results for the initial reassessment. The results showed that from 2016 to 2019, the consistency rate between the initial and re-evaluation results increased Table .Table 5CEnterococcus faecalis [Antibiotics play an important role in modern medicine. The discovery and use of antibiotics have led to medical breakthroughs, such as infection prevention after surgery. Furthermore, antibiotics have made substantial contributions to the control of infectious diseases . As a refaecalis . Althougfaecalis . We are Fortunately, an association between antibiotic use and resistance has been recognised . ProspecIn this study, we established a monthly evaluation system using random sampling and retrospective analysis of antibiotic prescriptions in the outpatient and emergency departments in a hospital. In contrast to the prospective reviews and interventions by clinical pharmacists, the monthly evaluation system was a response to the execution or review of antibiotic prescriptions. The monthly evaluation system supplements prospective review and intervention systems. Its main function is to compensate for human negligence in prescription review and, more importantly, to optimise the qualified prescription. This was demonstrated by the change in the proportion of antibiotics prescribed throughout this study, particularly the reduced rate of irrational prescription of antibiotics. Although the prescriptions approved by clinical pharmacists were qualified and had good curative effects, there was still room for improvement in the management of antibiotics owing to the differences in the experience and prescribing habits of doctors. Once the prescriptions were evaluated, they were reviewed by the evaluation team leader. Following both these rounds of review, the evaluation errors were minimised. The subsequent publicity of the results was one of the keys to the system. A US study suggested that disclosing institutional assessment scores could eventually change clinical practice . SimilarHowever, there were limitations to the study. In this study, we were unable to evaluate whether patients without a prescription required antibiotic treatment. In addition, the system did not achieve the same results for antibiotic prescription management in the emergency department as it did in the outpatient department. There was a decrease in the proportion of single antibiotics prescribed in the emergency department, and there was a significant increase in the proportion of two-dose antibiotics prescribed Table B. These We established a monthly evaluation system of antibiotic prescription with three rounds of evaluation and a public feedback system. We verified the effectiveness of this system in clinical antibiotic use management, which improved the professional level of medical staff, including evaluation team members. At present, the system is running efficiently. However, due to the spread of COVID-19 in 2020, the number of patients decreased considerably. We only intercepted the system data from July 2016 to 2019 for verification to exclude the epidemic factors. More detailed research is needed to develop more effective management systems for antibiotic use.


Background: Antibiotics are frequently prescribed–and overprescribed–at hospital discharge, leading to adverse-events and patient harm. Our understanding of how to optimize prescribing at discharge is limited. Recently, we published the ROAD (Reducing Overuse of Antibiotics at Discharge) Home Framework, which identified potential strategies to improve antibiotic prescribing at discharge across 3 tiers: Tier 1–Critical infrastructure, Tier 2–Broad inpatient interventions, Tier 3–Discharge-specific strategies. Here, we used the ROAD Home Framework to assess the association of stewardship strategies with antibiotic overuse at discharge and to describe pathways toward improved discharge prescribing. Methods: In fall 2019, we surveyed 39 Michigan hospitals on their antibiotic stewardship strategies. For patients hospitalized at participating hospitals July 1, 2017, through July 30, 2019, and treated for community-acquired pneumonia (CAP) and urinary tract infection (UTI), we assessed the association of reported strategies with days of antibiotic overuse at discharge. Days of antibiotic overuse at discharge were defined based on national guidelines and included unnecessary therapy, excess duration, and suboptimal fluoroquinolone use. We evaluated the association of stewardship strategies with days of discharge antibiotic overuse 2 ways: (1) all stewardship strategies were assumed to have equal weight, and (2) strategies weighted using the ROAD Home Framework with tier 3 (discharge-specific) strategies had the highest weight. Results: Overall, 39 hospitals with 20,444 patients  were included. The survey response rate was 100% (39 of 39). Hospitals reported a median of 12  of 33 possible stewardship strategies (Fig. Conclusions: The more stewardship strategies reported, the lower a hospitals’ antibiotic overuse at discharge. However, different pathways to improve discharge antibiotic use exist. Thus, discharge stewardship strategies should be tailored. Specifically, hospitals with limited stewardship resources and infrastructure should consider implementing a discharge-specific strategy straightaway. In contrast, hospitals that already have substantial inpatient infrastructure may benefit from proactively incorporating discharge into their existing strategies.Funding: NoneDisclosures: None


Neoadjuvant therapy favors the prognosis of various cancers, including esophagogastric junction cancer (EGC). However, the impacts of neoadjuvant therapy on the number of dissected lymph nodes (LNs) have not yet been evaluated in EGC.We selected EGC patients from the Surveillance, Epidemiology, and End Results (SEER) database (2006–2017). The optimal number of resected LNs was determined using X-tile software. Overall survival (OS) curves were plotted with the Kaplan–Meier method. Prognostic factors were evaluated using univariate and multivariate COX regression analyses.P = 0.003). The mean LN number of patients with neoadjuvant chemoradiotherapy was 16.3, which was also statistically lower than 17.5 (P = 0.001). In contrast, neoadjuvant chemotherapy caused a significant increase in the number of dissected LNs . For patients with neoadjuvant chemotherapy, the optimal cutoff value was 19. Patients with > 19 LNs had a better prognosis than those with 1–19 LNs (P < 0.05). For patients with neoadjuvant chemoradiotherapy, the optimal cutoff value was 9. Patients with  > 9 LNs had a better prognosis than those with 1–9 LNs (P < 0.05).Neoadjuvant radiotherapy significantly decreased the mean number of LN examination compared to the mean number of patients without neoadjuvant therapy (12.2 vs. 17.5, Neoadjuvant radiotherapy and chemoradiotherapy decreased the number of dissected LNs, while neoadjuvant chemotherapy increased it in EGC patients. Hence, at least 10 LNs should be dissected for neoadjuvant chemoradiotherapy and 20 for neoadjuvant chemotherapy, which could be applied in clinical practice. Esophagogastric junction cancer (EGC) invades the esophagogastric junction and involves the anatomic border between the proximal stomach and esophagus, with an increasing incidence worldwide , 2. The Due to strong invasive properties, a large fraction of EGC patients is detected at a locally advanced stage, and neoadjuvant therapy, including radiotherapy and chemotherapy, is required for most of them –11. AccuWe retrieved patients from the SEER database (2006–2017). Patients between 2004 and 2005 were not included in the study because of the missing chemotherapy data in the SEER database. The inclusion criteria were as follows: (1) positive histology; (2) underwent radical surgery; (3) definite tumor stage (T-category) and nodal stage (N-category), according to the 8th edition of the American Joint Committee on Cancer (AJCC) criteria; (4) first primary tumor; (5) at least one regional lymph node dissection based on pathologic evidence; (6) treatment with/without preoperative radiotherapy and/or chemotherapy; and (7) no distant metastasis. The exclusion criteria were: (1) under 18 years old; (2) unavailable follow-up data; (3) unknown cause of death. We retrieved baseline characteristics, including the year of diagnosis, race, age, sex, histology, grade, marital status, T-category and N-category. The data from all subjects from the SEER database was obtained legally.2 and t-tests. Univariate and multivariate analysis were performed with a Cox proportional hazards regression model to explore prognostic factors for EGC patients with neoadjuvant therapy. The optimal number of LN examination was explored using X-tile software . The overall survival (OS) was analyzed with a Kaplan–Meier analysis. Data were analyzed with PASW Statistics 18. A two-sided p-value < 0.05 was considered to indicate a significant difference.Differences between patients with neoadjuvant therapy and those without were analyzed by χP < 0.05).We enrolled 4028 EGC patients, including 2020 without neoadjuvant therapy, 498 with neoadjuvant chemotherapy, 39 with neoadjuvant radiotherapy, and 1471 with neoadjuvant chemoradiotherapy. The baseline characteristics are summarized in Table P > 0.05). In detail, patients with neoadjuvant chemotherapy had the highest mean number of dissected LNs , while those with neoadjuvant radiotherapy had the lowest mean number of dissected LNs . The mean LN number of patients with neoadjuvant chemoradiotherapy was 16.3, which was still significantly lower than 17.5 for patients without neoadjuvant therapy (P = 0.001).The mean number of dissected LNs was 17.5 among patients without neoadjuvant therapy and 17.3 among patients with neoadjuvant therapy (P > 0.05). This negative result might be related to the small sample size (39 cases). For patients with neoadjuvant chemotherapy, the optimal cutoff value was 19. Patients with > 19 LNs had a better prognosis than those with 1–19 LNs . For patients with neoadjuvant chemoradiotherapy, the optimal cutoff value was 9. Patients with > 9 LNs had a better prognosis than those with 1–9 LNs . Therefore, we divided the entire cohort into three groups according to the optimal number of LN examination: 1–9, 10–19, and > 19 LNs.We determined the optimal cutoff value for the number of dissected LNs using X-tile analysis. The optimal cutoff value was 11 for patients with neoadjuvant radiotherapy. However, the survival of patients with 1–11 LNs and those with > 11 LNs did not differ , T-category, and N-category were prognostic factors for patients with neoadjuvant chemotherapy Table . The mulEGC is a lethal disease with an increasing incidence and a poor prognosis . ConsideHerein, we evaluated the impact of neoadjuvant therapy on the number of dissected LNs in EGC patients using the SEER database. We found that neoadjuvant radiotherapy and chemoradiotherapy decreased the number of dissected LNs in EGC patients, while neoadjuvant chemotherapy increased it. Our results were consistent with previous studies regarding esophageal cancer in which radiotherapy/chemoradiotherapy would cause a decrease in LN number –24. ThesNumerous data, including National Comprehensive Cancer Network (NCCN) guidelines, have indicated that at least 15 LNs should be dissected for patients without neoadjuvant therapy to guarantee accurate staging and survival benefits , 30–32. However, our current study also has some limitations. First, this was a retrospective study with inherent limitations such as selection bias. Hence, a large prospective clinical trial is needed to validate our conclusions. Second, detailed chemoradiotherapy information was missing, including the type and dose of radiotherapy and chemotherapy, delivery methods, and duration of treatment, which might have some impact on the conclusions. Third, the SEER database has no quality-of-life information, which can not be ignored while treating malignant patients.Neoadjuvant radiotherapy and chemoradiotherapy decreased the number of dissected LNs, while neoadjuvant chemotherapy increased it in EGC patients. Hence, at least 10 LNs should be dissected for neoadjuvant chemoradiotherapy and 20 for neoadjuvant chemotherapy, which could be applied in clinical practice.