The current early warning scores may be insufficient for medical emergency teams (METs) to use in assessing the severity and the prognosis of activated patients. We evaluated the predictive powers of the Modified Early Warning Score (MEWS) and the National Early Warning Score (NEWS) for 28-day mortality and to analyze predictors of 28-day mortality in general ward patients who activate the MET.Adult general ward inpatients who activated the MET in a tertiary referral teaching hospital between March 2009 and December 2016 were included. The demographic and clinical characteristics and physiologic parameters at the time of MET activation were collected, and MEWS and NEWS were calculated.P < 0.001 for all comparisons). The areas under the receiver operating characteristic curves of MEWS and NEWS for 28-day mortality were 0.58  and 0.60 , which were inferior to that of the logistics regression model .A total of 6,729 MET activation events were analyzed. Patients who died within 28 days were younger (mean age 60 vs 62 years), were more likely to have malignancy (72% vs 53%), were more likely to be admitted to the medical department rather than the surgical department (93% vs 80%), had longer intervals from admission to MET activation , and were less likely to activate the MET during nighttime hours (5 PM to 8 AM) (61% vs 66%) compared with those who did not die within 28 days (Both the MEWS and NEWS had poor predictive powers for 28-day mortality in patients who activated the MET. A new scoring system is needed to stratify the severity and prognosis of patients who activated the MET. Patients in general wards can undergo acute deterioration, resulting in poor outcomes including unexpected intensive care unit (ICU) transfer, cardiac arrest, or death. Clinical deterioration is observed in 5%–9% of hospitalized patients in the general wards , 2. TimeThe early warning score (EWS) is a scoring system that assesses the risk of deterioration in hospitalized patients . The EWSThe current EWS systems may be insufficient for METs to use in assessing the severity and the prognosis of activated patients . Many scThis retrospective cohort study was conducted at Asan Medical Center, a tertiary referral teaching hospital with approximately 100,000 adult inpatients per year. Among all MET activation events in adult (aged 18 years or more) general ward patients that occurred between March 2009 and December 2016, the first activation event was included in the study. Exclusion criteria were as follows: activation by cardiac arrest; activation only to aid in equipment manipulation or procedures; activation that resulted in a do-not-resuscitate order; activation with missing data needed for calculation of MEWS and NEWS. The protocols of this study were approved by the institutional review board of Asan Medical Center (IRB No. 2016–0857), which waived the need for informed consent considering the retrospective nature of the study. Data of all study patients were de-identified before analyses to secure patients' personal information.We started operating an MET at our hospital for adult patients on a part-time basis (from 7 AM to 7 PM daily) in March 2008, and expanded its coverage to full-time in March 2009. The MET consists of 3 ICU staffs (intensivist), 4 ICU fellows, 2 internal medicine residents, and 9 dedicated nurses with experience in critical care. At least 1 intensivist or fellow, 1 resident, and 2 dedicated nurses work on every duty.S1 Table).The MET was activated when 1) the measurements of a patient exceeded the pre-defined thresholds in the electronic medical record-based automatic screening system, 2) doctors or nurses called the MET for aid, or 3) code blue was announced for cardiopulmonary arrest, as published previously . The eleAt the end of each MET activation, the MET nurse who participated in the activation event recorded the patient's data based on the medical record. Included data were as follows: age, sex, admission date, diagnosis at admission, comorbidities, date and time of MET activation, interval between admission and MET activation, clinical department at the time of activation, activation method , cause of activation, blood pressure, heart rate, respiratory rate, body temperature, level of consciousness , oxygen supply, peripheral oxygen saturation at the time of activation, do-not-resuscitate order before and after MET activation, MET activities, and the result of MET activation . The causes of activation were categorized into shock, respiratory distress, altered mental status, metabolic acidosis, or others (including hypotension and arrhythmias). In addition, ICU discharge date, hospital discharge date, and date of death in the patients with MET activation were collected annually. Variables that were not documented at the time of MET activation were treated as missing values. The primary outcome was mortality within 28 days after MET activation.U test for continuous variables and the chi-square test for categorical variables. If the patient survived to discharge within 28 days after MET activation, the patient was considered to survive for 28 days. To report predictive performance of MEWS and NEWS at the critical threshold, the cutoff values of MEWS ≥ 5 and NEWS ≥ 7 were used [P values of less than 0.05 were considered statistically significant. All analyses were performed using IBM SPSS Statistics version 21 .Data are presented as either mean with standard deviation or median with interquartile range (IQR). For continuous variables, the range of each quartile and the number of patients in each quartile are presented together. MEWS and NEWS were calculated from data at the time of MET activation. For the level of consciousness collected in the ACDU scale, confused and drowsy mental status were treated as 1 point of MEWS and unresponsive was treated as 3 points of MEWS based on the previous study . Mental ere used . The mulere used . Two-sidS1 Fig).A total of 11,102 MET activation events had occurred during the study period; the median annual number of activations was 17.3  per 1,000 admissions. After excluding activation by cardiac arrest (n = 745), activation to assist with equipment manipulation or procedures (n = 508), activation ended in do-not-resuscitate order , and activation with insufficient data for calculating MEWS and NEWS (n = 854), the remaining 6,729 MET activation events were included in the analysis  were younger (mean age 60 vs 62 years), were more likely to have malignancy (72% vs 53%), were more likely to be admitted to the medical department rather than the surgical department (93% vs 80%), had longer intervals from admission to MET activation , and were less likely to activate the MET during nighttime hours (5 PM to 8 AM) (61% vs 66%) compared with those who did not die within 28 days (survivors) . The physiologic parameters of the patients at the time of MET activation are presented in Table 2. The non-survivors had higher heart rate (114 vs 107 beats per minute) and respiratory rate (27 vs 25 breaths per minute), were less likely to be alert (63% vs 70%), and more likely to be given oxygen therapy (79% vs 66%) than the survivors . The treatment outcomes are shown in Table 3.As a result of MET activation, 2,274 patients (34%) were transferred to the ICU; 1,717 patients (26%) died within 28 days of the activation, and in-hospital mortalities occurred in 2,111 patients (31%). P < 0.001 in both comparisons). The distribution of MEWS and NEWS at the time of MET activation and ICU transfer as well as 28-day mortality rates at each score are plotted in Fig 1. When using a cutoff value of ≥ 5, MEWS had a sensitivity of 58.2%  and a specificity of 53.7%  for 28-day mortality (Table 4). Of the 3,407 patients with MEWS < 5, 827 patients (24%) were transferred to the ICU and 718 patients (21%) died within 28 days. When using a cutoff value of ≥ 7, NEWS had a sensitivity of 79.2%  and a specificity of 34.2%  for 28-day mortality. Among the 2,071 patients with NEWS < 7, 404 patients (20%) were transferred to the ICU and 357 patients (17%) died within 28 days. The AUROC of MEWS and NEWS for 28-day mortality were 0.58  and 0.60 , respectively. The multivariable logistic regression model for 28-day mortality was derived from the clinical and physiologic variables at MET activation . Age, comorbidities, medical department, days from admission, activation during daytime hours, activation by screening, activation causes, vital signs, mental status, and oxygen supply were identified as the predictors of 28-day mortality. The AUROC of the logistic regression model was 0.73 , which was superior to those of MEWS and NEWS .The non-survivors had significantly higher scores in both MEWS and NEWS  than did the survivors   needed to be transferred to the ICU or died within 28 days of MET activation. Our results suggest that it may not be appropriate for the MET to assess the severity of patients and determine the level of treatment solely based on MEWS or NEWS.Shappell et al. and Fernando et al. have evaluated the predictive power of EWS for the treatment outcome in patients with MET activation. Shappell et al. developed logistic regression and machine learning models for predicting in-hospital mortality and compared their discriminatory powers to that of NEWS using the national MET registry from 274 hospitals in the United States . The autWe identified multiple clinical characteristics as well as physiologic parameters at the time of MET activation that were significantly associated with 28-day mortality. Among them, the findings on vital signs, mental status, and oxygen supply are consistent with those of previous studies regarding EWS or MET , 18, 19.The current study is distinct from previous studies investigating the prognostic accuracy of the EWS in that patients with do-not-resuscitate orders were excluded. An important aspect of MET activities is aiding in the decision on a do-not-resuscitate order and providing end-of-life care. However, the decision on a do-not-resuscitate order is mostly based on medical futility and patient autonomy , not on This study is limited in that EWS was only calculated with the measurements at the time of MET activation. The predictive power of EWS may have been higher if we had used EWS at the beginning of acute deterioration before activation of the MET or the worst EWS during the episode of acute deterioration. Nevertheless, as the goal of this study was to investigate whether EWS at the time of activation was useful for the MET in assessing the severity and prognosis of patients, it was appropriate to use EWS at the time of MET activation. Also, we used the ACDU scale and not the alert/voice/pain/unresponsive (AVPU) scale in categorizing the level of consciousness. At our center, the ACDU scale has been used to detect deterioration in mental status earlier. There may be some difference between the EWS calculated based on the ACDU scale and the actual EWS. However, we converted the ACDU scale to the AVPU scale in the EWS based on previously reported data , and theBoth the MEWS and NEWS had poor predictive powers for 28-day mortality in patients who activated the MET, suggesting that MEWS and NEWS may be insufficient for stratifying the severity and prognosis of general ward patients who activate the MET. This warrants the need for the development of a new, practical scoring system for use by the MET in deciding the optimal treatment of patients and the allocation of medical resources.S1 Table(DOCX)Click here for additional data file.S1 FigMET, medical emergency team.(TIF)Click here for additional data file.S2 FigROC, receiver operating characteristic; MEWS, Modified Early Warning Score; NEWS, National Early Warning Score.(TIF)Click here for additional data file.


Nonlinear finite element (FE) analysis of reinforced concrete (RC) structures is characterized by numerous modeling options and input parameters. To accurately model the nonlinear RC behavior involving concrete cracking in tension and crushing in compression, practitioners make different choices regarding the critical modeling issues, e.g., defining the concrete constitutive relations, assigning the bond between the concrete and the steel reinforcement, and solving problems related to convergence difficulties and mesh sensitivities. Thus, it is imperative to review the common modeling choices critically and develop a robust modeling strategy with consistency, reliability, and comparability. This paper proposes a modeling strategy and practical recommendations for the nonlinear FE analysis of RC structures based on parametric studies of critical modeling choices. The proposed modeling strategy aims at providing reliable predictions of flexural responses of RC members with a focus on concrete cracking behavior and crushing failure, which serve as the foundation for more complex modeling cases, e.g., RC beams bonded with fiber reinforced polymer (FRP) laminates. Additionally, herein, the implementation procedure for the proposed modeling strategy is comprehensively described with a focus on the critical modeling issues for RC structures. The proposed strategy is demonstrated through FE analyses of RC beams tested in four-point bending—one RC beam as reference and one beam externally bonded with a carbon-FRP (CFRP) laminate in its soffit. The simulated results agree well with experimental measurements regarding load-deformation relationship, cracking, flexural failure due to concrete crushing, and CFRP debonding initiated by intermediate cracks. The modeling strategy and recommendations presented herein are applicable to the nonlinear FE analysis of RC structures in general. Finite element (FE) analysis is effective for investigating the nonlinear behavior of reinforced concrete (RC) structures and performing parametric studies at lower costs than experimental tests. The nonlinear FE analysis of RC members has been extensively reported, and good agreement is often achieved between numerical and experimental results ,2,3. HowThe major challenges in the nonlinear FE analysis of RC structures include the following: (1) defining the concrete tensile and compressive behaviors with the proper consideration of the strain localization in fracture zones , 2) eff eff2], , the sog cracks ,12,13. TConcrete crushing in compression: The constitutive model for concrete in uniaxial compression is usually provided as a stress–strain relationship in design codes, e.g., Model Codes [el Codes ,15 and Ael Codes . Howeverel Codes ,18,19 hael Codes  modifiedel Codes , assuminBond–slip behavior between concrete and steel reinforcement: In the nonlinear FE analyses of RC structures, the definition of the bond–slip behavior between the concrete and the steel reinforcement is critical for the accurate prediction of the structural responses, crack patterns, and crack widths [k widths ,3. Howevk widths ,23. Therk widths ,25 for aConvergence difficulties: The softening behavior and stiffness degradation of cracking or crushing concrete cause severe convergence difficulties in the static analysis of concrete [concrete ,26. Instconcrete  or expliconcrete  integratMisinterpretation: Misinterpretation refers to the users’ misunderstanding of the processing logic of FE software packages. Misinterpretation may cause the incorrect definition of input data, which may lead to errors in numerical results or aborted analyses [analyses . For insIn light of these challenges, the objective of this study was to develop a robust and reliable modeling strategy to capture the tensile cracking and compressive crushing behavior of RC structures associated with low computational costs and ease of implementation, based on the well-established constitutive relations from fib Model Codes ,15. The The RC members modeled in the present FE study included two slender RC beams subjected to four-point bending in the laboratory, see rocode 2 ; the Poiode 2010 ; the elaSTM A615 ; the elaorted in ; the elaorted in .3) and one steel cylinder roller (diameter of 3) to distribute the load to the RC beam. The beams were loaded to failure. In the reference beam, flexural failure after yielding of the reinforcement was governed by concrete crushing in the compressive side of the beam; the failure of the strengthened beam was due to premature debonding of the CFRP plate initiated by intermediate flexural cracks.In the four-point bending tests, the beams were simply supported on two movable steel supports, giving an effective span of 4.2 m. The steel support at each end consisted of two identical steel plates  were used to monitor the beam specimens. Two strain gauges were installed at the midspan cross-section on the tensile steel reinforcement, and three LVDTs were used to obtain the net deflection at the midspan, as shown in The proposed modeling strategy is discussed in detail, in this section, with special focus on proper modeling of RC considering strain-softening in fracture zones and bond–slip between steel reinforcement and concrete to ensure the reliable prediction of cracking and crushing. The strategy is adapted to the modeling of the RC beams introduced in Considering that the beam geometry and the test configuration were symmetric about the midspan, only one half of the RC beam was modeled in the current FE analyses to reduce the computational cost. The vertical load acting on the beam was defined as a boundary condition in the FE model, inducing a vertical displacement on the top of the steel plate between the load and the beam. The interaction between the steel plate and the beam was set as surface-to-surface contact, which defined the interfacial constraints in the normal direction  and friction in the tangential direction. The coefficient of tangential friction was assumed to be 0.57 according to a previous recommendation . The samThe concrete material is defined in the CDP model implemented in ABAQUS , includiThe concrete plasticity parameters to be defined in the CDP model include (1) dilation angle r et al.  with ther et al.  to accouf ABAQUS ; the val2) can be estimated using Equation (1) according to Mode Code 2010 [The tensile behavior of concrete is characterized by a linear elastic stress–strain relationship before the concrete reaches the tensile strength fct a and a bode 2010 . The Modode 2010 :(1)GF = To validate the adopted concrete tensile behavior, the effects of different modeling choices on the numerical results were investigated and are discussed in relation c proposeSmeared crack method: To simulate the cracks in concrete, the CDP model adopted in the present FE study employs the smeared crack method, where the cracking concrete is treated as a continuum and a physical crack opening Crack band approach: To define the smeared length a, it is reasonable to estimate the band width k regime . The crak regime ,13,44,45entation . However, ABAQUS , is simp, ABAQUS . Even foerred to ,46,47.In the present FE analyses, the crack bands developed in the concrete mesh mainly ran parallel to the mesh lines, owing to the predominant bending effect on the beam. Thus, the crack band width For the FE analysis of RC beams in bending, the concrete compressive behavior is widely defined according to a stress–strain relationship obtained from uniaxial compression tests of standard concrete cylinders. However, the strain in the standard compressive test is the “mean” strain obtained by smearing the measured displacement over the total length of the specimen. Considering that the compressive failure of concrete is initiated by a local shear band formed in one of the fracture zones and the post-peak deformation mainly arises from such a local zone, the “mean” strain naturally underestimates the strain in the critical fracture zone. If the post-peak deformation is expressed by the mean strain, the strain-softening curve tends to depend on the geometry of the specimen ,18—the dIn the present FE study, the relationship based on Model Code 1990  and Modeison see : the ThoTo obtain reliable predictions of the ultimate capacity and the crushing failure of the beam in flexural loading, the post-peak strain localization should be considered in the definition of the constitutive law. The original constitutive model based on the mean strain—mainly the post-peak softening branch—must be modified to better describe the localized strain softening in the critical fracture zone with a reasonable size. The assumed size should be verified according to the size of the simulated crushing zone.Modified compressive behavior considering strain localization: The procedure for modifying the post-peak branch is presented in L of the tested specimen are known, the increased post-peak deformation Considering the strain localization, instead of using Equation (4), the increased deformation after the peak stress The transitivity between Equations (4) and (5) implies that,The scaling rule for determining the localized inelastic strain Identifying the size of crushing zone: The modification of the post-peak strain-softening behavior also requires a proper assumption of the size of the critical fracture zone As the reference constitutive model adopted in the present FE analysis, the Model Code relation is reasonably accurate for specimens with a length of approximately 200 mm , providiIn the adopted CDP model, the concrete damage evolution is characterized by the degradation of the material stiffness  in the post-peak regime of the constitutive law. Considering the damage evolution beyond the peak stress, the initial elastic strain In the present FE analyses, the damage model proposed by Lubliner et al.  is adoptSubstituting Equation (10) into Equation (9) yields the damage variable, as follows:Importantly, the defined damage variable must satisfy the condition that the equivalent plastic strain truss is assigned. The material properties of the steel reinforcement are defined according to the results of standard tensile tests performed in the laboratory. The steel reinforcement, including the longitudinal reinforcing bars and the transverse stirrups, is modeled as a one-dimensional wire, to which the element type The proper modeling of the bond–slip behavior between the concrete and the embedded steel reinforcement is critical for obtaining clear discrete crack bands in the simulated beam model and reasonable flexural responses after the cracking point. In the present FE analyses, the bond between the longitudinal reinforcement and the concrete was assumed to be in good condition, and the bond–slip relationship according to Model Code 2010  is adoptTo implement the bond–slip behavior in the FE model, the use of connectors to build the node-to-node bond is proposed as a reference method. Another commonly applied method using cohesive elements ,54 is ims between the steel reinforcement and the concrete, as indicated by Equation (12). When the connector method is used, for obtaining an accurate simulation of the nodal bond forces and crack widths, the connector spacing (and the length of the steel reinforcement elements) should not exceed the size of the concrete elements.In the connector method, the bond–slip interaction is created using connectors (type: translator) between the nodes of the steel reinforcement and the nodes of the concrete. This method is adopted in the FE analyses as the reference modeling choice to assign the bond–slip behavior. To facilitate the assignment of node-to-node connectors, a Python script is developed to automatically implement multiple wire features between the neighboring nodes of the reinforcement and concrete. These wires can be efficiently defined using a suitable type of connector called translator, which allows uniaxial translation only in the direction of the steel reinforcement between the connected nodes. Considering that the bond–slip behavior is realized by discrete node-to-node connections, the bond force The cohesive method in ABAQUS can model the interfacial bond behavior in either cohesive-contact or cohesive-element approach. The cohesive-contact approach defines the cohesive behavior as part of a contact model with zero interface thickness. For instance, this approach is used in ,25 to efIn the modeling of the CFRP-strengthened beam, the bond between the CFRP plate and the concrete was modeled in the cohesive-element approach, as described in The static analysis procedure is used for the reference FE model to solve the nonlinear response of the RC beam subjected to monotonic loading. To overcome severe convergence difficulties in the static analysis ,26, the According to the proposed modeling strategy, the modeling choices adopted in the reference FE model were validated and analyzed via multiple groups of parametric studies. Additionally, through the parametric studies, the effects of available modeling alternatives were investigated, and the impacts of essential parameters were quantified.The dilation angle—one of the parameters defining the concrete plasticity—should be positive and in the range of 0°–56.3°. Malm 2009)  performe009  perfRC beams .Additionally, a parametric study was performed in the present study to investigate the effects of the dilation angle on the numerical results. ower φ = 5° or hig studies ,57, the As mentioned in µ, which is theoretically smaller than the characteristic increment in the step of the nonlinear solution [µ value that is too large  consider the strain localization in the critical fracture zone and (2) accordingly modify the post-peak strain-softening behavior of the concrete in compression with the verified size of the crushing zone As mentioned in The iterative procedure proposed in The modeling choices to be validated for the bond between the steel reinforcement and the surrounding concrete include the method of assigning the bond and the bond–slip relationship.The proposed connector method for assigning the steel-concrete bond was implemented in the reference model and compared with the cohesive-element method for validation. The numerical results for the flexural responses and crack patterns are shown in The effects of the bond–slip behaviors  on the flexural behavior and crack pattern in the FE analyses were investigated. In a perfect bond, all the degrees of freedom of the reinforcement nodes were constrained to the nearby concrete nodes, and there was no relative slip. The good and poor bond behaviors refer to the two bond–slip relationships provided in Model Code 2010  correspoThe static analysis procedure (aided by the viscoplastic regularization technique) was defined in the reference FE model. It was compared with an FE model using dynamic implicit analysis based on the approach proposed by Chen et al.  for valiThe FE models of the reference RC beam and the CFRP-strengthened beam followed the modeling strategy introduced in The flexural responses are expressed as load–deflection behaviors in Crack patterns and crack widths: The crack pattern documented at the load of 55 kN (the last measurement round) is shown in The experimental and numerical results of crack widths within the constant moment region are presented in Reliable prediction of the fast-growing crack openings after the yield point is crucial, as it is the foundation of advanced modeling with a focus on the consequential issues triggered by the opening of cracks. This was demonstrated by the modeling of the CFRP-strengthened beam; numerical results of the strengthened beam were compared to the experimental measurements with respect to its flexural response, concrete cracking, and CFRP debonding.Flexural behavior and CFRP debonding: The flexural responses of the CFRP-strengthened beam are depicted with load–deflection curves in Crack patterns and cracks widths: Reliable prediction of the IC debonding is highly dependent on the accurate simulation of cracks in the RC beam based on proper modeling options. Crack pattern and crack widths in the FE analysis were checked with the experimental measurements at different load levels. For example, As shown in Consistent approaches for deriving and defining the stress–strain relationships for concrete in tension and compression with consideration of the damage evolution and strain localization in the fracture zones of cracking and crushing concrete, respectively, were comprehensively described;Principles and recommendations for appropriately determining crack band width in structurally meshed concrete continuum to adjust the tensile stress–strain relationships were discussed and proved effective in avoiding the mesh sensitivity problem;An iterative implementation procedure was proposed to modify the concrete compressive stress–strain relationship in the post-peak regime according to the verified size of the crushing zone for considering the strain-localization effect;A simple and robust method was proposed for assigning the steel-concrete reinforcement interaction in ABAQUS using node-to-node connectors, and its accuracy was confirmed via a comparison with the commonly used method based on cohesive elements;Viscoplastic regularization using a properly defined viscosity parameter exhibited the capability to overcome the convergence difficulties encountered in the simulation of cracking or crushing concrete and thus significantly reduced the computational time;The proposed modeling strategy, as exemplified through the FE analyses of a reference RC beam, provided a reliable simulation of nonlinear responses including the development of cracks and resistance to concrete crushing. The ability to capture these effects on this simple case laid the foundation for the accurate modeling of CFRP debonding induced by intermediate flexural cracks in the strengthened beam, which provided an example of modeling RC structures with additional complexity.In this paper, a robust modeling strategy for reliable nonlinear FE analyses of RC structures was proposed. The modeling choices adopted for the reference FE model were validated through parametric studies and comparisons with other commonly used options; the effects of these choices on the numerical results were investigated. The contributions of this study are summarized as follows:Most of the recommendations presented in this paper for the nonlinear concrete model are general and applicable to FE analyses of other quasi-brittle material models with different FE software. The proposed modeling strategies can be directly used to model RC beam and frame structures with different dimensions, loading configuration, and boundary conditions. The current study also paves the way to FE analyses with higher degrees of complexity.


Saccharomyces cerevisiae modulates growth of antibiotic susceptible and resistant Escherichia coli and potentiates bactericidal antibiotic efficiency through modulation of bacterial cellular respiration. The role of MRF in modulating bactericidal impact and cellular metabolic state were assessed in E. coli by monitoring microbial growth and by measuring oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) using the Seahorse XFe96 Analyser, respectively. This work further illustrates the link between bacterial susceptibility to antibiotics (phenotypic resistance) and resistance through modulation of bacterial metabolism. This is the first example of yeast MRF enabling collateral sensitivity to antibiotics in vitro and supports the search for alternative strategies to promote animal health without contributing to the growing issue of antimicrobial resistance.Now more than ever there is a demand to understand the mechanisms surrounding antibiotic resistance and look for alternative ways to impact phenotypic antibiotic outcome. Cellular energetics can be impacted by many bacteriostatic and bactericidal antibiotics, which affect metabolism and energy output, resulting in a reduction of cell growth or induction of cell death respectively. In this study, we provide evidence that a mannan rich fraction (MRF) from the cell wall of  Antibiotic efficiency has been linked to the bioavailability of molecular oxygen contributing to the electron transport chain4. Bacteriostatic and bactericidal antibiotics inhibit cell growth or induce cell death, respectively, and are defined phenotypically based on how they target different cellular processes. Specifically, changes to cellular metabolic state have been linked to changes in the phenotypic output of different antibiotic classes5. These antibiotics modify cellular metabolic status, in particular via respiration by a number of means, such as formation of ROS and production of harmful hydroxyl radicals7, or by way of 8. Bacteriostatic antibiotics target translation9, whereas bactericidal antibiotics are believed to directly influence transcriptional upregulation of metabolic and respiratory genes, and have also been linked to carbon flux through the TCA cycle10. Both classes of antibiotics are capable of modification of cellular energy dynamics via modulation of these processes11. With regard to bactericidal antibiotics, previous work has shown the cellular response induces metabolic lethality via ROS formation suggesting that increasing or accelerating respiration may enhance bactericidal activity8. Attempts to amplify antibiotic activity through combining antibiotic treatments has shown diverse effects on bacterial survival7 and has in some instances had negative implications due to attenuation of bactericidal activity over bacteriostatic lethality8. In general, greater efficiency by means of combinatorial antibiotic treatments have displayed additive, synergistic or antagonist effects, in some instances leading to unpredictable permutations. Dietary mannan-oligosaccharides (MOS), as prebiotic zootechnical feed ingredients, are derived from the outer cell wall of yeast and have been extensively studied as a non-pharmaceutical alternative to antibiotic growth promoters14. MOS, with its ability to bind and limit the colonisation of gut pathogens18, has proven to be an effective feed supplement supporting immunity and digestion19. Further refinement of yeast MOS has led to the isolation of a mannose-rich fraction (MRF) with enhanced activities in immune modulation and intestinal health. In the present study we examine how potentiation of cellular respiration enhances antibiotic efficiency.Due to the prevalence of antibiotic resistance and in trepidation of its future global impact, research into ways in which we can support antibiotic restriction is imperative. Central to enhancing our understanding of antibiotic resistance and susceptibility, are investigations into the core mechanisms involved and ways in which we can potentiate beneficial physiological responses without contributing to resistance. Cellular metabolism is a key mitigator in positively or negatively influencing antibiotic activity15. By examining the respiration profile of Escherichia coli, we gained an insight into how ampicillin, a bactericidal antibiotic, targets growth inhibition and leads to acceleration of cellular respiration. Our data shows that MRF supplemented in the culture media reduced the growth of both sensitive and resistant E. coli and positively influenced phenotypic antibiotic outcome when in combination. The data indicates the link between cellular oxygen consumption rate (OCR) and presence of MRF with respect to the bactericidal lethality of ampicillin. Development of antibiotic target-based resistance and the potential unpredictability of antibiotic combinations encourage exploration of non-pharmaceutical alternative sources such as MRF to reduce resistant populations and enhance antibiotic effectiveness. This research is therefore timely with respect to the search for alternate strategies to promote animal health without contributing to antimicrobial resistance.Previous research determined that bacterial susceptibility to antibiotics is mediated by microbial metabolic regulationE. coli in conjunction with bactericidal antibiotic treatment. When MRF was supplemented (≥ 0.1% (w/v)) in the media of antibiotic susceptible E. coli, with no ampicillin treatment, a significant reduction in final growth measurement (p ≤ 0.01) and maximum optical density (OD) (p ≤ 0.05) was observed  were obtained from Sigma.One Shot TOP10 chemically competent 595nm was adjusted accordingly by spectrophotometer (Shimadzu UV-1601PC).Frozen stocks of bacteria [5% (v/v)] in 70% glycerol were stored at − 70 °C in LB medium. Working plates were prepared by transferring a single colony using spread plate technique to fresh agar and incubating overnight. Streaked plates were stored at 4 °C for up to six months. Fresh inoculum was prepared by isolating a single colony from working plates into approximately 25 mL of LB broth and grown overnight at 37 °C. Optical density (OD) at λ−1) was sterilised at 105 °C for 30 min. If agar was required, 15 g L−1 was added before autoclaving. To facilitate the growth of E. coli, medium was cooled to approximately 55 °C, after which AMP and TET were added to a final concentration of 100 µg mL−1 and 30 µg mL−1, respectively. Agar plates were stored in the dark at 4 °C and were warmed to 37 °C prior to use.LB medium . To this, 20 μL aliquots of the test organism (adjusted to 0.01 OD at λ595nm (approx. 1 × 10–8 cfu mL−1)) was added to each well. A reference control (RC) with no antibiotic was included per MRF concentration. The plate was then incubated under appropriate growth conditions; in this case 37 °C. The OD was read every hour following a 5 s medium shake for a total of 18 h. Optical density measurements following 18 h incubation were taken and compared to the reference control. Glucose (0.1% (w/v)) was used as a positive control. Replicate analysis was conducted using a Tecan Infinite M200 Pro microplate reader. The growth rates in each well were estimated using the same strain in identical media and the experiment was repeated three times independently, with three replicates per sample.MRF [0–0.5% (w/v)] was prepared in MHB broth. Aliquots of 200 μL per well and analysed in triplicate at OD λE. coli cells were diluted into fresh LB media and grown to an OD λ595nm of ∼ 0.3 at 37 °C. Cells were centrifuged at 4000 rpm for 5 min then washed with fresh M9 media. This process was repeated twice. Cells were diluted to 0.015 with fresh M9 minimal medium or M9 supplemented with MRF (0.01 or 0.1% (w/v), respectively). For OCR measurements, 90 μL of diluted cells were seeded onto XF cell culture microplates, precoated with 15 µL poly-d-lysine (PDL) (Sigma) and centrifuged for 10 min at 1400 rpm to enable attachment. Cellular respiration was quantified following addition of 90 μL of fresh M9 media to each well. To assure uniform cellular seeding, basal OCR was measured for two cycles before automated antibiotic injection (20 µL) and then quantified every 6 min for the duration of the experiment post-treatment. To examine cellular energetic state, OCR and ECAR measurements were used to form energy map diagrams.Bacterial respiration expressed as OCR was quantified using an XFe96 Extracellular Flux Analyzer (Seahorse Bioscience). Overnight cultures of susceptible and resistant https://sourceforge.net/projects/growthrates/24. GrowthRate reports correlation coefficient, R, of the best fit line to the natural log of the optical density (ln(OD)) over time for each culture. For each set of replicate cultures, GR reports the mean growth rate, the mean R, max OD and lag time  software, downloadable from e Tables  and S2.p ≤ 0.05.Statistical analyses of results were performed using Minitab statistical software package version 16 (Coventry U.K.). One-way analysis of variance (ANOVA) and Fishers multiple comparisons were carried out to test any significant differences among means, where the confidence level was set at 95%. One-way analysis of variance (ANOVA) and Dunnett’s comparisons were carried out to test any significant differences between each test mean and a control mean, where the confidence level was set at 95%. Significant levels were defined using Supplementary Information.


The value of 0I was increased to approximately 3.1 and 2.9 times the initial value for the PV modules without and with concrete, respectively.Several tests were conducted to ratify the reliability and durability of the solar photovoltaic (PV) devices before deployment in the real field . In the real field, the temperature of the PV modules was varied during the day and night. Nowadays, people have been bearing in mind the deployment of PV modules on concrete roads to make use of the space accessible on roads. In this regard, a comparative study on the failure and degradation behaviors of crystalline Si PV modules with and without a concrete slab was executed via a thermal cycling stress test. The impact of the concrete slab on the performance degradation of PV modules was evaluated. Electroluminescence (EL) results showed that the defect due to thermal cycling (TC) stress was reduced in the PV module with a concrete slab. The power loss due to the thermal cycling was reduced by approximately 1% using a concrete slab for 200 cycles. The  Over the years, the photovoltaic (PV) community has put great efforts into reducing the cost per kWh of PV power, which is mainly dependent on the manufacturing costs of the PV system, its efficiency, and its lifetime. In this regard, extensive research work is going into the study of the reliability and durability of PV modules with a focus on their thermomechanical and corrosive degradation under different operating conditions ,2,3. In Recently, solar-powered roads that incorporate embedded crystalline silicon (c-Si) modules have attracted great interest since they can be used for transportation and power generation. A few examples are finally being rolled out around the world to replace asphalt roads with solar panels ,10. HoweI-V) measurements are performed to determine the PV cell parameters  under the illuminated condition concerning the observed degradation of the PV module performance. An electroluminescence (EL) imaging technique is also used for the detection of defects such as microcracks and poor electrical contacts and the analysis of degradation processes that occur during the test. In this work, a comprehensive study on the failure and degradation behaviors of c-Si PV modules fixed over a concrete slab is performed via a TC stress test, and a relationship between the device performance and TC duration is established. Combined analysis techniques are employed to examine the degradation mechanisms in the PV modules subjected to the TC stress test. Current–voltage (I-V characteristics based on a one-diode model [phI is the photogenerated current and TV (= kT/q) is the thermal voltage .Illuminated de model ,15 of p-de model (1)I= IpshR, sR, n, and 0I:scR and ocR are the inverse of the slope (dI/dV)−1 at short circuit  and open circuit  conditions, respectively. Equations (2)–(5) can be used to extract the values of PV cell parameters using the values of scI, ocV, scR, ocR, mI, and mV of single I-V characteristics under illumination conditions.A one-diode exponential model-based analytical method is used to extract the PV cell parameters of the PV modules at a given temperature under illumination conditions ,17. The 2. The rigid modules included 36 cells, with an Al frame (cell area = 31.2 cm2). The modules were subjected to a thermal cycling (TC) test to evaluate the ability of the module to withstand thermal mismatch, fatigue, and other stresses caused by temperature fluctuations. The test was conducted using an environmental chamber equipped with an automatic temperature control (−40 to 85 °C). The TC stress was conducted using a chamber . First, the temperature of the environmental chamber was decreased from 25 °C to −40 °C in 35 min; then, the temperature was kept constant at −40 °C for 30 min. The temperature was increased from −40 °C to 85 °C in 90 min.The study has been carried out on monocrystalline PV modules (approximately 20 W) with an area of 1540 cmI-V and electroluminescence (EL) measurements and appearance. The PV modules were mounted on a concrete slab to protect the back surface from exposure in an environment . The bacI-V characterization was done after every 20 thermal cycles of each batch. The I-V measurements were carried out under a 100 mW/cm2 intensity AM 1.5G solar spectrum using a Keithley 2420 source-meter along with a solar simulator . All measurements were done after stabilizing the temperature of PV modules (at 25 °C). The illumination intensity of the solar simulator was calibrated using a reference Si solar cell . EL scanning was carried out after every 20 cycles using the EL system  equipped with a camera .I-V characteristics were measured periodically (after every 20 cycles) during the TC test (200 cycles) to profile the progression of degradation. The optical images of the reference PV module before and after TC (100 and 200) cycles are shown in mP, short-circuit current sc,I open-circuit voltage oc,V and efficiency η) were extracted from the I-V curves, and their dependency on the thermal cycling was discussed concerning the EL images. In this study, the c-Si PV modules were fixed on a concrete slab using an isolation box and insulating tape to reduce the heat flow toward the back surface of the PV modules. Thus, two PV modules with a concrete slab were analyzed, while other PV modules without a concrete slab were used as a reference. It is worth noting that the use of the concrete leads to an improvement of the normalized power values compared to that of a reference PV module. I-V characteristics for both the PV modules before and after thermal cycles (100 and 200). These characteristics showed clear signs of series resistance increase, which is mainly attributed to the thermal fatigue undergone by the PV module. The corresponding power-voltage (P-V) characteristics are shown in mP, scI, ocV, and η were determined from the I-V data, and dependency is illustrated in scI and ocV. This degradation is evident after 40 cycles with a significant variance in power loss. The mP value of the PV module with concrete was reduced to 98.9% and 97.1% of its initial value (before TC) after thermal cycling of 100 and 200 cycles, respectively. However, the degradation in the reference PV module was slightly higher than the concrete PV module. The mP value of the reference PV module is reduced to 97.6% and 96.1% of the initial value, respectively. The scI value of the concrete PV module is slightly increased up to 100 cycles, while the reduction in the scI of reference PV module started after 40 cycles. This slight improvement in the scI might be due to the reduction of the resistive loss caused by proper contact formation. The scI values after 200 cycles were reduced by 97.4% and 98.7% for the reference and concrete PV modules, respectively. The ocV value of both the PV modules started to reduce after 20 cycles. However, the rate of reduction of ocV value for the PV module with concrete was higher than the reference PV module. After 200 cycles, the obtained ocV value was reduced by 1.4% and 1.0% for the reference and concrete PV modules, respectively. Moreover, the ocV and scI losses for the concrete PV module were lower compared to those obtained for the reference PV module. The power degradation for the concrete PV module after 200 cycles was approximately 2%, while the maximum power loss measured for the reference module was approximately 3%. These values are below the limit of 5% allowed by the IEC. On the other hand, the η value was reduced to approximately 3% and 2% of its initial value for the reference and concrete PV modules, respectively.The values of sR increases, and consequently, the maximum power of the module decreases. EL images of the PV module with concrete are displayed in To identify the specific degradation mechanisms and module defects that manifest during the TC test, EL images were taken for all modules. shR of the PV module with concrete is initially increased with the increase in the number of thermal cycles. The shR value up to 80 cycles is slightly higher than the initial value . With a further increase in the thermal cycle, the shR value started to decrease. However, the shR value of the reference PV module is constantly decreasing with the increase in the thermal cycle. For the reference PV module, both the surface (front and back) are exposed to the environment. However, the back surface of the PV module with a concrete slab is covered, which isolates the back surface from exposure to the environment. Thus, the impact of TC on the PV module with concrete is slightly lower than the reference PV module. Usually, shR is due to the parallel current flow through a highly conductive path, which is caused by local defective regions [shR values are decreased with the thermal cycle, which results in an increase in the leakage current through the p–n junction or from the edge [shR has a miserable impact on ocV. Therefore, the output power or overall efficiency is reduced. The shR value is reduced to approximately 71% and 91% after thermal cycling of 200 cycles. The performance parameters are directed via PV cell parameters. The origins of the degradation in the performance parameters can be investigated by analyzing the PV cell parameters of the PV cells/modules. The degradation of the performance parameters can also be explained via the PV cell parameters, whose variation is shown in  regions . The def regions ,21. The  regions . The gen regions . Thus, tthe edge . A low vsR slightly decreased up to 100 cycles. With the increase in the number of cycles, sR started to increase. A similar variation in the sR value is obtained for both the PV modules. After 200 cycles, the sR value was increased to approximately 108% and 109% for the reference and concrete PV modules, respectively. The sR of a PV device is the collective resistance of the base material of the PV cell, the contact resistance between PV material and contacts, metallic resistance, etc. Initially, the decrease in the sR value with the increase in the thermal cycle is mainly due to the reduction of the contact resistance. However, furthermore, the increase in thermal cycling caused the rise in the value of sR due to the increase in the contact resistance at the metal contact–solder interface. Both the n and 0I values are increased with an increase in the number of cycles. However, the variation of the n and 0I is lower for the PV modules with concrete. The increment in the value of n is 4% and 5% for the reference and concrete PV modules, respectively. Moreover, the value of 0I is increased to approximately 3.1 and 2.9 times the initial value for the reference and concrete PV modules, respectively. n and 0I are indicative of the recombination in the PV devices, which rigorously reduced the performance of the PV modules [ocV decreases with the increase of 0I [n and 0I values.In both the PV modules, the value of  modules ,24. An ise of I0 . Thus, tocV and scI losses for the concrete PV module were also lower compared to those obtained for the reference PV module. PV cell parameters were determined using an analytical method based on a single diode model. The obtained PV cell parameters were examined to investigate the loss mechanism. The shR value was reduced to approximately 91% and 71% after thermal cycling of 200 cycles for reference PV modules, respectively. However, the sR value was increased for both the PV modules. Moreover, the value of n was slightly increased in both the cases, while the value of 0I was increased to approximately 3.1 and 2.9 times the initial value for the reference and concrete PV modules, respectively.The impact of the concrete slab on the performance degradation of PV modules was evaluated as per IEC standard TC stress testing conditions. EL results showed that the defect due to TC stress was reduced in the PV module with a concrete slab. After 200 thermal cycles, approximately 3% and 2% power loss was obtained for the reference and concrete PV modules, respectively, which revealed that the performance degradation in the concrete PV module was reduced via protecting the backside of the PV modules. The concrete slab can slightly protect the PV module from thermal soaks. Moreover, the


Cracking can facilitate deteriorations of concrete structures via various mechanisms by providing ingress pathways for moisture and aggressive chemicals. In contrast to conventional maintenance methods, self-healing is a promising strategy for achieving automatic crack repair without human intervention. However, in capsule-based self-healing concrete, the dilemma between capsules’ survivability and crack healing efficiency is still an unfathomed challenge. In this study, the feasibility of a novel property-switchable capsule system based on a sustainable biomass component, polylactic acid, is investigated. Capsules with different geometries and dimensions were studied focusing on the compatibility with concrete, including survivability during concrete mixing, influence on mortar and concrete properties, and property evolution of the capsules. The results indicate that the developed elliptical capsules can survive regular concrete mixing with a survival ratio of 95%. In concrete containing 5 vol.% of gravel-level capsules, the compressive strength was decreased by 13.5% after 90 days, while the tensile strength was increased by 4.8%. The incorporation of 2 vol.% of sand-level capsules did not impact the mortar strength. Degradation and switchable properties triggered by the alkaline matrix of cement were observed, revealing the potential of this novel biomass capsule system in achieving both high survivability and self-healing efficiency in concrete. The high brittleness and low ductility make concrete susceptible to cracking in the presence of mechanical loadings or environmental attacks. The formation of cracks in concrete makes it more permeable by providing pathways for the ingress of external moisture and aggressive chemicals and thereby making concrete vulnerable to a variety of deteriorations, such as corrosion of steel reinforcement ,2, carboOne of the novel techniques to achieve a substantial crack capacity of composite materials without human intervention is self-healing. Different self-healing approaches have been investigated in concrete materials, including; (i) autogenous healing based on filling of cracks by hydration of unhydrated cement particles ,16 or caThe encapsulation prevents the participation of the healing agents during the hydration period of cement. Some healing agents, like bacteria, need encapsulation to survive the harsh environment inside the concrete so that they can become active when the cracks are formed ,33,34. AAs shown in In this study, to leverage the physical and chemical features of PLA, capsules with different dimensions and geometry shapes were manufactured through 3D printing to simulate the sizes of coarse and fine aggregates used in concrete. The feasibility of using this novel concept of biomass capsules in self-healing concrete was evaluated by investigating the survivability of capsules in regular concrete mixing, the switchable properties of the capsules in the alkaline environment of concrete and mortar, as well as the influence of the capsules on the property development of mortar and concrete. The degradation behavior of the capsules was investigated through tension test, thermogravimetric (TGA), and microstructure analyses. The self-healing potential of the concrete containing the biomass capsules filled with sodium silicate was also preliminarily evaluated. 1) was used for the manufacturing of gravel-size and sand-size capsules used in concrete and cement paste. The transparent filament (PLA2) was used to manufacture sand-size capsules in the matrix of mortar only. TGA analysis of unaged PLA shows that the onset and burnout temperature ranges are 320–356 °C and 374–443 °C, respectively. Reagent-grade sodium silicate (Na2SiO3) solution, with a composition of 10.6% NaO2 and 26.5% SiO2, was used as a healing agent. Type I/II Ordinary Portland cement, river sand, and all-purpose 3/8-inch gravels were used for mortar and concrete specimens. The specific gravity of the cement, fine aggregate, and coarse aggregate are 3.15, 2.7, and 2.6, respectively. The chemical and mineral compositions of the cement are summarized in PLA 4043D with an L-lactic/D-lactic ratio from 24:1 to 30:1, melting range from 150 °C to 180 °C (302–356 ℉) and a glass transition temperature from 55 °C to 60 °C (131–140 ℉), which is generally selected for 3D printing, was used for dog-bone specimens in a tensile strength test. Two PLA filaments, one white and one transparent, were used in 3D printing. The white filament  through thermal injection. PLA degradation in the alkaline environment was investigated by immersing PLA dog bone specimens in a 0.1 M (mol/L) sodium hydroxide solution with a pH value of 13 under room temperature simulating the alkalinity of regular concrete pore solutions.3, an aspect ratio of 1.5, and a shell thickness of 0.4 mm were designed. The capsule-based healing system was developed by injecting sodium silicate (Na2SiO3) solution. The summary of the capsule dimension and geometry is presented in Hollow elliptical capsules were manufactured via fused deposition modeling (FDM) technique using a precision three-dimensional (3D) printer with a nozzle diameter of 0.4 mm. To obtain a smooth surface finish and accurate dimensions, the 3D printing was performed with an extruder temperature of 205 °C, a bed temperature of 60 °C, and a layer thickness of 0.2 mm at a print speed of 50 mm/s. In this study, the capsules were manufactured at two different size levels: gravel level and sand level. To investigate the influence of dimension and geometry on the survivability of the gravel-level capsules, 12 groups with two minor diameters of 9.5 mm and 19.05 mm simulating the commonly used gravel sizes (i.e. 3/8 inch and ¾ inch), different aspect ratios (major to minor diameter ratios of the ellipsoids) at 1:1:1, 1.5:1:1 and 2:1:1, and a series of shell thickness of 2.0 mm, 1.6 mm, 1.2 mm, 0.8 mm and 0.4 mm were studied. To investigate the compatibility of the biomass capsule in the matrix of mortar, sand-level capsules with a dimension of 7.5 × 5 × 5 mm3 beams were cast based on a cement to sand to gravel ratio of 1:2:3. A water to cement ratio of 0.4 was employed and the water absorption of the aggregates was taken into account to adjust the amount of mixing water. A superplasticizer was used to improve the workability of concrete. A previous study by Lv and Chen [Concrete cylinders with a dimension of 76 mm by 152 mm, and 76 × 76 × 254 mmand Chen  indicateand Chen  followedand Chen , and it 3 were prepared according to ASTM C109 [3 at a volume fraction of 2%. 100 × 100 × 100 mm3 cement paste cubes were also prepared to investigate the influence of elevated temperature on the capsule’s degradation rate. For these cement paste samples, a cement ratio of 0.40 was employed and only two sand-size capsules were embedded. The cubes were covered with plastic wrap to prevent water evaporation followed by demolding after 24 h. After demolding, the mortar and cement paste cubes were cured in saturated lime water at room temperature (23 ± 2 °C) and 50 °C, respectively.Mortar specimens with a dimension of 100 × 100 × 100 mmSTM C109  using TyA tension test was conducted on the dogbone specimens to understand how PLA performs in a simulated service condition of the concrete matrix and to predict how the capsules rupture under tension. The tension test of the raw and aged PLA dog-bone specimens after being immersed in the 0.1 M sodium solution for 7 days, 14 days, 1 month and 3 months were performed on an Instron universal testing machine at a displacement rate of 5.08 mm/min according to ASTM D638 . Three r3 was mixed to ensure a low capsule volume percentage of 0.82%. As shown in To determine the resistance of capsules to concrete mixing, a survivability test was performed by mixing the capsules with concrete in a revolving drum tilting mixer according to ASTM C192 . After tAccording to ASTM C39  and ASTM2 inert atmosphere (flow rate of 20 mL/min). The tangent method was employed for data analysis on the TGA and the derivate TG (DTG) curvesTGA was performed to monitor the degradation behavior of the PLA capsules inside the concrete, mortar, cement paste under different curing conditions. The degraded PLA capsule shells were extracted using tweezers from the fracture surfaces of the specimens after compression and split tension tests. The collected capsule shell chips were cleaned by removing cement residues and were dried at 80 °C for 24 h to eliminate the free water. The TGA tests were carried out on a Perkin Elmer TGA4000  in a temperature range from 30 °C to 800 °C at a heating rate of 10 °C /min under NA proof-of-concept test for the crack-healing capacity of concrete containing the developed biomass capsule system was studied by introducing flexural cracks in concrete beams after 90 days of curing. The release of sodium silicate from the capsules and crack closures were monitored. The concrete beams were loaded in a three-point bending setup by stages on an Instron universal testing machine as shown in The micromorphology of the aged gravel-level capsules in concrete after 90 days and sand-level capsules after being embedded in mortar for 270 days was performed on a digital microscope and a JSM-7401F field-emission scanning electron microscope (SEM)  under an accelerating voltage of 10 kV, respectively. The samples used for imaging were taken from the fracture surface of concrete and mortar specimens after the compression and split tension tests. For the SEM test, the sample surfaces were made conductive by sputtering deposition of a thin layer of gold using a Denton vacuum sputter coater.The survivability of capsules during concrete mixing is characterized by determining the resistance of the capsules to breakage during regular concrete mixing. The capsules which did not break during mixing are denoted as intact capsules, among which the ones that did not leak after mixing are known as active capsules. Therefore, two ratios were determined: (i) intact ratio, which is the percentage of intact capsules, and (ii) survival ratio, which is defined as the ratio of the active capsules to the total number of capsules of each group. It should be noted that the survival ratio is equal to or lower than the intact ratio as leaking can be observed from some intact capsules. Previous research ,86 has sThe influence of aspect ratio on the survivability of the capsules with two different minor diameters (i.e. 9.5 mm and 19.05 mm) is also investigated. As shown in The influence of shell thickness on the survivability of capsules at the 9.5 mm (3/8 in.) gravel level was investigated for two aspect ratios (1.5:1:1 and 2:1:1). As shown in These results highlight the tremendous potential of the biomass capsules to survive the harsh concrete mixing condition and suggest promising strategies for self-healing concrete. Based on the systematic investigation and result analysis of the 12 groups, it can be concluded that, due to PLA’s excellent mechanical properties and the precise 3D printing process, all groups show acceptable survivability with the lowest survival ratio of 85%. To leverage this merit, and maximum the delivery capacity and the switchable properties of the biomass capsules triggered by alkaline degradation of PLA, the group exhibiting the highest survivability with a minor diameter of 9.5 mm, an aspect ratio of 2:1:1, and a shell thickness of 0.4 mm (G6) was selected for the following concrete-level investigations.After addressing the challenge of survivability, the capsules need to be susceptible to concrete cracks to achieve efficient cracking capacity. Upon concrete cracking, the capsules should be able to capture the cracks and rupture to release core healing agents for crack healing. To achieve this goal, in this study, a concept of evolutionary property is proposed. Although the PLA-based biomass capsules are strong enough to survive the concrete mixing process, their mechanical properties would decrease in concrete triggered by the alkaline nature of the cement matrix and the degradation behavior of PLA. To validate this hypothesis, the degradation behavior of PLA and capsules in alkaline solution simulating concrete pore solutions and in the matrices of concrete, mortar and cement under different curing conditions were investigated.The degradation rate of PLA in the 0.1 M sodium hydroxide (NaOH) solution with a pH of 13, which is similar to that of the pore solutions in concrete, was determined by monitoring the tensile strength loss of dog-bone samples over time. Given the importance of switchable properties in controlling the release of healing agents and crack healing, the degradation behavior of PLA capsules in the matrices of concrete, mortar, and cement paste under different curing conditions was investigated via TGA on capsule samples extracted from fracture surfaces of cylinder and cube specimens after strength tests. In addition to the reduced weight loss, decreased thermal stability was also observed from the aged PLA capsules. As shown in The TGA and DTG curves of the unaged and aged sand-level biomass capsules in the matrix of mortar cured in saturated lime solution at 23 °C are shown in In addition to the room temperature, the degradation behavior of the biomass capsules in the matrix of cement paste was also investigated under an elevated temperature of 50 °C. The combined results from the capsules embedded in the matrices of concrete, mortar and cement paste reveal a slow degradation of PLA-based capsule shells during the first 28 days and a significant degradation up-to 90 days indicating the potential of this biomass capsule system to achieve good compatibility with the matrices to eliminate negative impact on workability and strength gain of young concrete and also ensure crack healing in mature concrete. Further investigations in these two aspects are shown in To further understand the compatibility of the two biomass capsule systems in mortar and concrete, the development of the mechanical strength of concrete cylinders and mortar cubes was investigated. Although the degradation rate of the biomass capsules can be accelerated under elevated temperatures, to approximate the strength evolutions of concrete and mortar in real structures, this investigation was conducted on samples cured under room temperature.Influences of the gravel-sized capsules on the development of compressive and splitting tensile strength of concrete cylinders are shown in As shown in Comparing with the observations in concrete, the incorporation of sand-size capsules shows less impact on the compressive strength development of mortar. As shown in This study focuses largely on the feasibility and compatibility of using the PLA-based biomass capsules in concrete. Therefore, in this study, the self-healing capacity of the capsule system was preliminarily investigated based on a fundamental proof-of-concept test. Evidence of inside-out seal-healing agent release via the newly formed cracks was observed on the surface of concrete cylinders during and after the compression and split tension tests see . From coMicromorphology of the biomass capsules in concrete and mortar was characterized by a digital microscope and SEM under different magnifications. As shown in Under SEM, the interface between capsules and the cement matrix can be observed in more detail. From Among the groups with a variety of dimensions and geopmetry shapes, elongated ellipsoidal capsules with a smaller size and higher aspect ratio yielded higher survivability, while shell thickness did not exhibit a discernible effect on the survival ratio of the biomass capsules. By considering survivability and healing agent delivery capacity , capsules with a minor diameter of 9.5 mm, an aspect ratio of 2:2:1 and a shell thickness of 0.4 mm, which yielded intact and survival ratios of 100%, and 95%, respectively, were chosen for further studies on concrete properties. The switchable properties of the biomass capsules were validated by monitoring the alkaline degradation of capsule shell material. It was observed that, after immersing in an alkaline solution (pH 13) for three months, the tensile strength of PLA was decreased by 24.3%, while the Young’s modulus was increased by 26.6%. TGA results showed negligible degradation of PLA in the cementitious matrix during the first 28 days, whereas significant degradation was observed after 90 days under both 23 °C and 50 °C. Decreased thermal stability was also observed from the degraded capsule shells.Concrete containing a 5% volume fraction of gravel-sized biomass capsules showed a reduction in compressive strength of up to 18.5% compared to the plain concrete, while the splitting tensile strength was not negatively impacted. Incorporation of 2 vol.% sand-sized capsules resulted in comparable and even increased compressive strength of mortar.Based on a fundamental proof-of-concept test, the developed biomass capsule system showed promising self-healing prospects as a 0.5 mm wide flexure-induced crack introduced in a concrete beam was healed by solid C-S-H gel, which is formed as reaction products between sodium silicate healing agent, cement hydration products and lime water. The fracture surface of completely ruptured beams showed a 100% breakage ratio of capsules indicating successful release of self-healing agent into the surrounding cracks.The microstructure analysis showed that, due to the aged shells and good interfacial bonding with the cement matrix, the capsules can easily be raptured either transversely or longitudinally. Hardened silicate reaction products and sodium silicate can be observed around the raptured capsules. The mineralization of the capsule shell, indicated by the stripped-off micro-fibrils and embedded cement hydration products, was also observed.The present study evaluates the feasibility and compatibility of using novel PLA-based biomass capsules as a potential carrier for the healing agents in self-healing concrete. Using the 3D printing technique, capsules with a variety of geometries and dimensions were manufactured. Survivability of the capsules during regular concrete mixing was determined based on intact and survival ratios. The effects of the gravel-size and sand-size capsules on the mechanical properties of concrete and mortar were evaluated. To validate the hypothesis of switchable properties of the biomass capsules in the matrix of cement, degradation behavior was monitored using a tension test, TGA, and microstructure analysis. A fundamental proof-of-concept test was also conducted to verify the crack self-healing efficiency of the concrete. The experimental results presented in this paper indicate the possibility of utilizing biomass components as property-switchable capsules to address the current challenges in self-healing concrete. The following conclusions can be drawn:


At the European scale, the most studied topics were related to the environment, food, chemicals, pigments, protein, feed, and drugs. The highest scientific trends and market opportunities analysis identified bioplastics and biostimulants as top emerging concepts at the European level and agricultural, animalfeed, and bluebiotechnology at the European AA level. A bibliographic database of scientific papers published by authors affiliated worldwide, especially focused in Europe and in the European Atlantic Area, and containing the keywords “microalga(e)” or “phytoplankton” was built. A corpus of 79,020 publications was obtained and analyzed using the Orbit Intellixir software to highlight the evolution of the research domain. Publication rates from 1960 to 2019, organization of the research, collaboration networks between countries and organizations, emerging and fading research concepts, major studied species, and associated concepts, as well as journals publishing microalgae research were considered. As a result, of the 79,020 papers published worldwide, 26,137 included authors from Europe (33% of world production) and 6989 from the European Atlantic Area (AA) . The main worldwide scientific research topics found in this study were  Microalgae, with an estimated number of 30,000 to 1,000,000 species, constitute a vast group of microorganisms extensively studied for their ecological functions in marine and freshwater environments and possible use as a source of feed, food, cosmetics, biofuels, nanomaterials, and pharmaceuticals ,3. SinceIn 2018, the scientific production reached 5747 publications per year in the world, 1806 (31% of the world production) publications per year in Europe, and 509 (28% of the European production) publications per year in the AA. From the results explained above, it can be noted that Europe and the European AA follow roughly the same publication trend as the world trend. An increased interest of the scientific community in microalgae can be noticed since 2005, as demonstrated by the rapid increase in the world and European publication rates and the important inflection of the publication slope, as highlighted by Garrido-Cardenas et al. (2018). These authors estimated that a 15-fold acceleration of the publication rate was observed after 2005 [Concerning European countries, the United Kingdom, France, Germany, Spain, and Italy were the main European countries producing scientific publications in the field of microalgae worldwide, with 5818, 5448, 5248, 4106, and 2925 publications, respectively. The five countries of the European AA  were among the seven that published the most with co-authors in the AA. In this top seven, the U.S. and Germany published 836 and 494 scientific publications, respectively, with co-authors from the European AA. phytoplankton, community, bloom, diatoms, distribution, ecosystem, coastal, chlorophyll, zooplankton, photosynthesis, and primary production. This environment/phytoplankton research domain can be differentiated from the microalgae/high-added-value molecules field that contained less and more recent publications, as previously reported [reported . Feed was the predominant emerging concept for the three geographical areas, with a very high growth factors (GF) compared to the rest of the emerging concepts  [hnology) .The 28 countries of the European Union produced 26,137 publications in the field of microalgae and phytoplankton; these papers are analyzed in detail in this section.Within the European Union, countries producing the largest number of publications are France (5445), Germany (5258), Spain (4100), Italy (2852), Netherlands (2353), the United Kingdom (2030), Sweden (1654), Denmark (1446), Poland (1192), Belgium (1189), Portugal (1164), and Finland (904). In addition, between 400 and 600 scientific publications have been published by Greece (556), the Czech Republic (555), Austria (484), and Ireland (416). The production of scientific publications was lower for Switzerland (348), Croatia (343), Hungary (338), and Estonia (319). Regarding the number of scientific papers published until 2019 for the 15 top publisher countries in Europe, France and Germany were the first to produce an important number of publications in Europe, with 100 publications per year since 1996 and 1997, respectively. Spain reached 100 publications per year in 2001, and the U.S. and Italy produced 100 per year in 2007. The number of scientific publications per country continues to increase each year. The city of Paris produced more than 50 scientific publications per year since 2007 and reached more than 100 publications per year since 2017. Wageningen, Lisbon, Kiel, and Barcelona each produced 50 scientific publications per year since the year 2000.environment, with 8962 publications, dominating the domains related to food and chemicals that contain 4275 and 4271 publications, respectively. These keywords cover very broad topics and more specific markets have fewer publications (less than 2000 publications). For example, many publications have been produced in Europe in the field of pigments (1861), proteins (1847), feed (1818), drug (1474), biofuel (1014), and biotechnologies (892). biostimulant (13), bioplastic (14), vaccines (16), biofertilizers (22), and nanotechnology (59).Hydrobiologia was the top publisher in Europe, with 1162 publications and an impact factor of 2.165. The majority of these journals relate to environmental/phytoplankton research and have impact factors ranging from 1.897 to 4.61 for an average of 2.69. The main journals related to the microalgae/high-added value molecules field are Bioresource Technology and Algal Research, with impact factors of 5.807 and 3.745, respectively.Chlorella sp. is the most published genus with almost twice as many publications as Scenedesmus sp. (733) and Chlamydomonas sp. (641). For each of genera, the corresponding emerging concepts are listed in Chlorella sp., the top emerging concepts were biostimulant and agro industrial waste  species).Chlorella sp. in Following the identification of the top 15 microalgae genera studied in Europe, a detailed study of associated and emerging concepts, scientific consortia working on these genera in Europe, research cities, temporal evolution of publications by country, top journals, citations, and top cited papers was performed. The results of this advanced analysis are presented below for https://www.enhancemicroalgae.eu/). To compare on a global scale, 9% of world publications came from the AA, 15% of world authors were from the AA, and 37% of affiliations working in the field of microalgae were located in the AA. In this section, the AA was compared with Europe for (i) the main concepts and topics of scientific publications, (ii) the national contribution to publications, (iii) the networks of collaborations by city and country, as well as (iv) the main journals and citations in the field of microalgae. The EnhanceMicroalgae project is a transnational and inter-regional Atlantic project that aims to evaluate the potential of the European AA in the microalgae industrial sector  (https:/biofuel (+55 publications), drug (+54), health (+44), and bioremediation (+31). In contrast, research topics such as environment (-58), biogas (-30), protein (-29), and chemicals (-26) were less published in the AA as compared to the European average. Other research fields ranging from +10 to -10 are in line with European research priorities , Italy (325), Germany (322), and France (310), followed by Portugal, the Netherlands, the U.S., Belgium, and the United Kingdom that have published each between 100 and 150 publications on microalgae high added-value molecules since 2017. The major AA cities working in this field are Wageningen, Paris, Rome, Lisbon, Barcelona, Almeria, and Nantes with 85, 66, 64, 63, 58, 57, and 50 publications including at least one co-author in the AA, respectively. As shown in microalgae/biomass/growth/cell/concentration. By dismissing these ubiquitous concepts, a network of 18 clusters was created in which model, treatment, acid, lipid, chemical, energy, nutrient, cultivation, green and carbon were the dominant concepts  are concepts .Regardless of their size, the contribution of each country for publications in the AA, namely, Ireland, the United Kingdom, France, Spain, and Portugal, was compared in this section. The United Kingdom mainly contributed to these publications, as the United Kingdom affiliations were identified in 33% of the publications compared to 25% and 24% for France and Spain, respectively. Portugal produced 15% of the scientific publications in the European Area and Ireland was associated with 5% of the publications .The international scientific collaborations of the European AA were analyzed in this section in order to highlight strong collaborations but also to identify collaborations that could be developed for a better sharing of research at geographical and thematic levels. Marine Ecology Progress Series, Estuarine Coastal and Shelf Science, and Journal of Plankton Research with 263, 209, and 193 publications, respectively. As observed in the European database, the journals publishing the highest number of microalgae AA studies are related to environmental/phytoplankton research. The main journals publishing papers related to microalgae/high-added value molecules are Bioresource Technology and Algal Research-Biomass Biofuels and Bioproducts, with impact factors of 5.8 and 3.7, respectively, and Progress in Oceanography (IF 4.27). Despite the dominance of environmental science journals, the two scientific publications with the highest citations in the AA deal with the production of high-added value molecules from microalgae and are entitled “Microalgae for biodiesel production and other applications: A review” and “Biofuels from microalgae-A review of technologies for production, processing and extractions of biofuels and co-products“. These papers were published in 2010 and cited 2610 times and 2124 times, respectively , Germany, Italy, and the Netherlands (particularly from Wageningen).A bibliographic database was built through a literature search performed in February 2019 including all reports published to date. The use of the Scopus database was compulsory to obtain a format compatible with the bibliometric analysis using the Orbit Intellixir software. The keywords “microalgae” and “phytoplankton” were used to list world publications, European publications , and European publications including at at least one author from the Atlantic regions of Portugal, Spain, France, the United Kingdom, and Ireland, as defined in the interregional (Interreg) AA research programs . The keyThe bibliographic database was last updated in February 2019 and it contained 79,020 publications, 111,975 authors, 4446 affiliations, and 931,299 concepts. These references are available on demand to the corresponding author.P being the number of cumulative scientific publications containing the concept at one time.A “concept” designates a word (or group of words) present in the title, summary, or keywords of a publication that can be extracted and identified using a bibliometric software. The occurrence of a concept is the number of documents containing this concept, and co-occurrence the number of documents linking several concepts. The bibliographic database, including references without duplicates, was imported from Scopus (Editor Elsevier) into the Orbit Intellixir bibliometric software and analyzed to quantify the scientific production per year, country, organization, and annual evolution of publication rates. Collaboration networks between countries; public and/or private organizations; as well as major, fading, and emerging research concepts, were graphically represented using the most relevant formats available in the Orbit Intellixir software. Data were analyzed to highlight the latest trends in research topics; identify the most explored research concepts; point out the most studied species; and highlight strengths, opportunities, and collaborations in the research organizations from the European AA. Emerging concepts were defined as concepts that showed the greatest increase in frequency of use in the database over the last 2 years. A manual selection of emerging concepts was performed, as some of them were relevant for our study , whereas others were less . A growth factor (GF) was calculated to highlight the concepts with the highest emergence over the past 2 years (2017-2019). GF was calculated as Equation (1).phytoplankton, community, bloom, diatoms, distribution, ecosystem, coastal, chlorophyll, zooplankton, photosynthesis, and primary production. Focusing at the European AA level in which the Interreg EnhanceMicroalgae project is positioned, the analysis of the 6989 publications revealed that the biofuel, drug, health, and bioremediation topics are more published than at the European average. The major publishers of these AA publications were located in the United Kingdom, France, and Spain, particularly in research poles of Southampton, Vigo, Plouzané, Lisbon, Brest, Nantes, and Plymouth. In contrast, compared to Europe, the AA produced less scientific publications in the field of microalgae-based high added-value molecules (1882 publications), suggesting a scope to extend in term of research, collaboration, and industrial development. The highest scientific trends and market opportunities were highlighted by identifying top emerging concepts such as bioplastics and biostimulants at the European level and agricultural, animal feed, and blue biotechnology at the European AA level. By focusing at the European scale, the most studied topics found in the 26,137 European publications were related to the environment, food, chemicals, pigments, protein, feed, and drugs. Analysis of international cooperation highlighted the strong links and partnerships with the United States, Canada, Norway, and Australia, but identified the possible development of new collaborations with most other countries. Within the European Union, France, Germany, and Spain dominated the scientific productivity, and the most studied and published species were Chlorella sp. and Scenesdesmus sp. A large number of microalgae and cyanobacteria species have received minimal attention, indicating a significant innovation potential for new molecules, new applications, and markets. Finally, this study provides an updated review of quantitative data at three different reading levels, and should allow microalgae stakeholders to guide their investments and projects for future research opportunities and cooperation in the field of microalgae research and bioeconomy.On the basis of the analysis of 79,020 publications at the world, European, and European AA levels, our study aimed to give a relevant overview of microalgae research until 2019, an in-depth analysis of research concepts and collaborations, and a European perspective on emerging topics. Studied microalgae species were also analyzed in detail to highlight their associated concepts, the networks of researchers working in the field, and the potential of development for new applications or new species. The scientific research topics were essentially the same at the world, European, and AA levels, with the main research concepts corresponding to


Botrytis cinerea, the activation of several sugar transporters, from both plant and fungus, illustrates the struggle for carbon resources. In sink tissues, the metabolic use of the sugars mobilized in the synthesis of defence compounds or antifungal barriers is not fully understood.The main soluble sugars are important components of plant defence against pathogens, but the underlying mechanisms are unclear. Upon infection by B. cinerea was used to examine, before and throughout the course of infection, the transcriptional activity of enzymes involved in sugar metabolism. Under different nitrate nutrition regimes, the expression of genes that encode the enzymes of sugar metabolism  was determined and sugar contents were measured before inoculation and in asymptomatic tissues surrounding the lesions after inoculation.In this study, the nitrogen-dependent variation of tomato stem susceptibility to Sl-SUS1 and Sl-SUS3, cell wall invertases Sl-LIN5 to Sl-LIN9 and some fructokinase and phosphofructokinase genes. By contrast, increased susceptibility corresponded to the early repression of several genes that encode cell wall invertase and sucrose synthase. The course of sugar contents was coherent with gene expression.At high nitrogen availability, decreased susceptibility was associated with the overexpression of several genes 2 d after inoculation: sucrose synthases The activation of specific genes that encode sucrose synthase is required for enhanced defence. Since the overexpression of fructokinase is also associated with reduced susceptibility, it can be hypothesized that supplementary sucrose cleavage by sucrose synthases is dedicated to the production of cell wall components from UDP-glucose, or to the additional implication of fructose in the synthesis of antimicrobial compounds, or both. The leaves of healthy plants synthesize carbohydrates through photosynthesis and they export sucrose, which is carried via the phloem and unloaded in sink tissues such as stems, roots or fruit via sucrose transporters (SWEET transporters) or plasmodesmata . Once inSl-LIN5 to Sl-LIN9 code for cell wall invertases, Sl-VI codes for a vacuolar invertase and Sl-NI for a mitochondrial invertase. Sl-SUS1 and Sl-SUS3 to Sl-SUS7 encode six sucrose synthase isozymes. Among the hexokinase genes Sl-HXK1 to Sl-HXK6, three are located in the cytosol and associated with the mitochondrial membrane (Sl-HXK1 to Sl-HXK3), one is plastidial (Sl-HXK4) and two have not been located (Sl-HXK5 and Sl-HXK6). Among the four fructokinases reported in the literature, three are cytosolic  and one is plastidial (Sl-FRK3). In addition, eight putative phosphofructokinases have been identified in the tomato genome (Sl-PFK1 to Sl-PFK8).Most of the genes that encode these enzymes have already been described in tomato. Host sugars play a central role in plant–pathogen interactions . During Botrytis cinerea is a plant pathogenic fungus with a broad host range. Unlike biotrophs, necrotrophic pathogens such as B. cinerea kill host cells and feed on decayed tissues  were sown and the seedlings were transferred 10 d after germination onto 7 × 7 × 6 cm rock wool blocks. After three additional weeks, the plants (bearing three or four leaves) were placed on top of 2-L pots filled with a mixture (1:1 v/v) of vermiculite and pozzolana. From germination to the beginning of the nitrate treatment, the plants were fertigated twice a day with a standard commercial nutrient solution . The nitrate treatments were started 7 weeks after germination. Four nutrient solutions were used, containing nitrate concentrations of 0.5, 2, 10 and 20 mm. It had been previously shown in similar experiments that 10 mm is the optimal concentration for growth, and that 20 mm corresponds to an excess of nitrogen supply, while 0.5 and 2 mm correspond to severe and mild nitrogen stress, respectively. In the solutions with lower nitrate concentrations, the equilibrium in electric charges was maintained by replacing nitrates  with sulphates , up to 7.5 mm SO42− in the solution containing the lowest nitrate concentration (0.5 mm NO3−). This substitution is unlikely to have affected plant growth since tomato is known not to be affected by very high sulphate supply concentrations : 0.5 B, 0.02 Cu2+, 8.2 Fe2+, 0.5 Mn2+, 0.01 MoO42− and 0.1 Zn2+. The plants were fertigated using a drip irrigation system (one dripper per pot) up to nine times a day depending on the climatic demand, with 2-min pulses. All plants received the same amount of water. The pH was adjusted to 6.0 in each treatment by adding H3PO4.Protocols similar to those previously described  were useBotrytis cinerea strain BC1 was grown on plates containing potato dextrose agar medium  in a growth chamber . Conidia were collected in sterile ultra-pure water from the surface of 14-d-old cultures. Each suspension was filtered through a 30-µm mesh sterile filter to remove mycelium fragments, and adjusted to a concentration of 107 conidia mL−1 with the help of a haemocytometer.Botrytis-inoculated plants at each date). Inoculations were carried out in the morning  on the petiole stubs (5–7 mm long) that remained on the stems after excision of the sixth leaf. The wounds received a 10-µL aliquot of either the spore suspension (Botrytis-inoculated plants) or sterile water (mock-inoculated plants).Thirty-five plants were used for each nitrate treatment, corresponding to seven batches of five biological replicates, sampled just before inoculation [0 d post-inoculation (DPI)], and at 2, 4 and 7 DPI ]. During this period, the plants were fertigated manually twice a day until drainage, thus maintaining the nitrate treatments until the end of the experiment.To foster disease development, the Y1/2) + Σ 2n − 1 (Yj + (Yn/2))][I], where Yj was the observed lesion (in mm) at the jth observation time, n was the total number of observations, and I was the interval between each observation .The disease was assessed by measuring the length of the lesion expanding on the stems on a daily basis. The area under the disease progress curve (AUDPC) was computed as: AUDPC =  , where tThe data presented are the averages of five biological replicates  ± standard error. The differences between treatments were analysed using a Kruskal–Wallis test followed by a Wilcoxon rank-sum test when necessary. All the statistical analyses were performed using R software.−1 DW at 0.5 and 2 mm NO3−, compared with 0.038 g g−1 DW at 10 mm NO3− and 0.024 g g−1 DW at 20 mm NO3−. The glucose contents were around 0.062 g g−1 DW regardless of the nitrate treatment. The fructose contents were slightly lower, 0.0049–0.0054 g g−1 DW at 0.5 and 2 mm NO3−, compared with 0.0069–0.0072 g g−1 DW at 10 and 20 mm NO3−  showed significantly different expression levels depending on the nitrate treatment, except for Sl-SUS1, Sl-SUS4 and Sl-NI  relative value. Among all the genes examined, only the expression of Sl-SUS3 at 20 mm NO3− reached a significantly higher mean value than this 1.5 threshold. As for the kinase-encoding genes, a similar trend of higher relative expression for plants grown at 10 and 20 mm NO3− was noted, but the differences were only significant for Sl-HXK1 and Sl-FRK3.As the hexose-to-sucrose ratio was affected by nitrate treatments, we investigated the expression of genes that encode invertase, sucrose synthase, hexokinase, fructokinase and phosphofructokinase . Five amnd Sl-NI . Most ofB. cinerea and incubated for 7 d. The petiole stubs were colonized and lesions developed on the stems within 72–96 h. The AUDPC was computed based on the measurement of lesion lengths between 4 and 7 DPI. As expected based on previous studies, nitrate treatments affected plant susceptibility , no differences between Botrytis and mock-inoculated plants were observed. Fructose and glucose contents decreased between 0 and 7 DPI. Sucrose content dropped between 0 and 2 DPI, and remained roughly constant thereafter at 10 mm NO3−, while at 20 mm NO3− it remained constant between 0 and 4 DPI and slightly increased between 4 and 7 DPI. Contrasts between Botrytis-inoculated and mock-inoculated plants were much more pronounced under low nitrate treatment. Fructose and glucose contents initially decreased after inoculation with Botrytis, but while glucose showed no significant change between 2 and 7 DPI, fructose started to accumulate between 2 and 4 DPI at 0.5 mm NO3−, and 4 DPI at 2 mm NO3−. An opposite pattern was observed in mock-inoculated plants, with an initial rise in glucose and fructose contents, followed by a decrease at 2 DPI. The sucrose content of infected plants started to drop at 4 DPI, while that of mock-inoculated plants started to decrease earlier, at 2 DPI. Thus, the major difference observed between infected and mock-inoculated plants was the accumulation of fructose in infected plants in the low nitrate treatments.The sugar contents were analysed after confirmation by qPCR of the absence of culation . Under sBotrytis-inoculated plants relative to those of mock-inoculated plants measured on the same day (y axis) as well as the gene expressions of inoculated plants relative to those measured before inoculation (x axis) are plotted in Cq are highlighted in The expression of genes involved in sugar metabolism after inoculation was examined. The expressions of sugar metabolism genes in Botrytis inoculation stimulated the expression of Sl-SUS1 and Sl-SUS3 at 2 DPI, but the transcript levels (relative to those of mock-inoculated plants) were much higher for plants grown at 10 and 20 mm NO3− than for plants grown at lower nitrogen levels  and the expression of genes involved in the catabolism of sucrose and the first phosphorylating steps of glycolysis. The metabolites and transcript levels were quantified in symptomless stem tissues surrounding Botrytis lesions. Stems are sink tissues for which little is known regarding the relationship between sugars and the response to infection. The particularity of sink tissues lies in the activity of sucrose synthase, generally not detected in source tissues  and over-optimal (20 mm) nitrogen availability could correspond to the higher stem volumes observed in these treatments. However, the overexpression of Sl-SUS1 is dependent on both infection and high nitrogen availability. Here we highlight the conditional involvement of some specific isoforms of sucrose synthases in a successful defence.In the present work, the inoculation of Sl-LIN6 invertase was overexpressed in all nitrate treatments during the course of infection. In leaves of tomato and Arabidopsis infected by B. cinerea, Sl-LIN6 , 4 (B) and 7 (C) DPI.Supplementary data are available online at mcaa155_suppl_Supplementary_MaterialClick here for additional data file.