This study presents three-point bending fracture tests on glass fiber-reinforced polymer (GFRP) reinforced concrete notched beams. Few studies have been conducted to date to understand the fracture behavior of this type of specimens. The specimens have nominal depth, width, and length equal to 150 mm, 150 mm, and 550 mm. Plain concrete notched beams with the same dimensions are cast from the same batch of concrete to compare the responses with GFRP reinforced concrete notched beams. The notch of the plain concrete specimens is either saw cut or cast. These two notch fabrication methods are compared based on the load responses. The peak load, crack mouth opening displacement (CMOD), GFRP bar slip at two ends, and load point displacement are used to discuss the results of the fracture tests. In addition, digital image analysis is performed to identify the fracture process zone (FPZ) and the location of the neutral axis, which are used to determine the force in the GFRP bar via cross-sectional analysis. Finally, the GFRP bar force versus slip responses are compared with those from the pull-out tests performed on the same bar to show that the bond of the bar in the pull-out tests represents an upper bound limit compared to the behavior in bending. Glass fiber-reinforced polymer (GFRP) bars have become a major alternative to traditional reinforcing steel bars in concrete structures, and they have been perceived by many experts as a promising material in reinforced concrete (RC) technology . GFRP baThere are several advantages in using GFRP bars as reinforcement in concrete members instead of traditional steel bars: (1) GFRP bars are lightweight and corrosion free compared to steel bars; (2) they have high tensile strength and high stiffness-to-weight ratio; 3) they are more durable than steel bars; 4) they are transparent to electromagnetic fields; and 5) RC structures with GFRP bars can be easily demolished if necessary [ they are they are RC strucIn recent times, GFRP reinforced concrete member has been used extensively in many civil engineering projects. In sensitive projects, such as seawalls, dams, and power plants, designers are prone to use GFRP bars due to their corrosion resistance. Piles reinforced with GFRP bars are found to be more durable due to resistance to corrosion compared to piles reinforced with steel bars . For simIn the past, researchers studied extensively FRP reinforced concrete members and established the design guidelines ,13,14. HFew studies were conducted to examine the fracture behavior of steel-reinforced concrete beams using a TPB test set-up. The location of the steel bar in the concrete beam was varied in , and it In this study, the fracture behavior of GFRP reinforced concrete notched beams is examined through TPB tests. Fracture test parameters, namely the CMOD, load point displacement, and peak load, are obtained and analyzed. Plain concrete notched beams are also tested and their behavior compared with the GFRP reinforced notched beams. The effect of casting the notch rather than saw cutting it after the concrete is cured is also investigated by testing plain concrete beams with both cast initial notch and saw cut notch. Finally, DIC is used to obtain the displacement and strain fields on the beam lateral face. The load point displacement (LPD) is also obtained from DIC analysis and compared with the LPD obtained from linear variable displacement transformers (LVDTs). Strain and displacement fields and contour plots from DIC analysis are presented to study the characteristics of the fracture process zone (FPZ) ,23,24,25This study is conducted to gather in-depth knowledge of the fracture behavior of GFRP reinforced notched beams. The bond between the bar and concrete is a key aspect to investigate the use of GFRP bars in reinforced concrete. This paper tackles two aspects: (1) the relationship between the pull-out tests and bending tests; (2) the relationship between the opening of a flexural crack and the slip of the bar.In this Section, the experimental campaign is described. First, the mechanical properties of the concrete and the reinforcing GFRP bar are presented. Then, the geometrical dimensions and the preparation of the specimens for the TPB tests are described. Finally, the test set-up and the procedure are explained.All the notched beam specimens and the cylinders for material characterization were cast from the same batch of concrete. The mixture proportions of different constituents of the concrete by weight were cement (2.6):water (1):fine aggregates (10.3):coarse aggregates (10.5). The maximum aggregate size was 12 mm. The slump test was performed at the beginning of the casting process according to , and theCompressive tests were performed on 150 mm (diameter) by 300 mm (height) cylinders at different ages  according to . At 28 dk and n were 0.56 and 0.5, respectively, according to ACI 318-11 [The tensile strength of concrete was obtained using the following formula from ACI 318-11 :(1)f′t=kI 318-11 . The tenbd was 12.7 mm, and the calculated cross-sectional area (barA) was 127 mm2. The tensile modulus of elasticity of the bar (barE) was 46 GPa [Four notched beams were reinforced with a GFRP bar. The GFRP bars were sand coated and were wrapped spirally with a carbon yarn a. Accords 46 GPa , and theThree bars were tested to determine the average tensile strength and the load versus stroke curves; the results of these tests are shown in D), width (B), and length (L) of the specimens were 150 mm, 150 mm, and 550 mm, respectively. The span (S) was three times the depth of the specimens. A 75 mm long and 3 mm wide concrete notch (a0) was either cast or saw cut at the midspan cross-section for all specimens.In total, nine notched beams were tested in a three-point bending test configuration. Four out of nine beams were reinforced with a GFRP bar. A photo of the test set-up and the specimen is shown in The GFRP bar extended beyond the concrete specimens at both ends. This extension was necessary to allow for the measurement of the bar slip at the free ends of the bar. A photo of the wooden mold used for these specimens is shown in l = 100 mm, centered with respect to the notch. The internal diameter of the PVC pipe was 20 mm. The concrete was poured from the side face of the notched beams, i.e., the notch front was perpendicular to the troweled face of the specimen. This orientation allowed having the molded faces as the top and bottom faces of the specimen when it was placed in the testing rig. Three more specimens were cast in a similar manner  as described above, except they were cast without the bar . The DIC set-up is shown in D), width (B), and length (L). In addition, after the test was completed, three measurements of the length of the initial notch (a0) were taken . The average of these measurements along with their CoV are presented in S) of the specimens. These two cylinders worked as supports for the specimen and rolled on the steel blocks attached to the base. Another cylinder was placed on top of the specimen to apply the load at the midspan. Springs were used to hang the cylinder from a spherically seated block that was attached to the top head of the testing machine. Two steel bearing plates were glued to the bottom of the specimen and were placed on top of the supporting cylinders to reduce the friction between the concrete and the rotating support cylinders. The cylinders had a radius of 0.2D, the steel bearing plates had a width of 0.17D, and the depth of the steel bearing plate was half of its width. The steel fixtures were cleaned of any dust and debris before each test. On the top face of the specimen, between the loading cylinder and concrete, a Z-shaped steel plate was used. This Z-shaped plate had a V-shaped section on the top face, so that the loading cylinder rested firmly on it. Both the Z-shaped plate and the steel bearing plates were longer than the width (B) of the specimen. Two steel bars with semi-spherical- and cylindrical-shaped supports were placed on the extended part of the steel bearing plates on both sides of the specimen. Each steel bar was equipped with a linear variable displacement transformer (LVDT) that reacted off the flange of the Z-shaped plate placed on top of the specimen. The average of these two LVDT readings is named the load point displacement (Δ). It should be mentioned that when the DIC was used, only one LVDT was used to measure the load point displacement. For some specimens with GFRP bars, two additional LVDTs were used to measure the free end slip of the bar at the end cross-sections of the concrete beam. Two aluminum rings were glued to the protruding portion of the bars at the two ends of the concrete beams. The rings were used to mount two aluminum plates that held the LVDTs, which reacted against the surface of concrete. Prior to testing, two C-shaped steel plates were glued on the bottom surface of the notched beams near the edges of the initial notch. Two knives were then screwed in on the C-shaped plates. The knives were used to mount the clip-on-gauge. The TPB test set-up used in this study was based on the draft of the ACI/ASCE 446 Technical Committee report, which was used in [Prior to testing each notched beam (with or without the bar), three measurements were taken for each of the dimensions, i.e., depth  of each test and the average along with its CoV for each group . For the PN_B_X specimens, the first peak load before the descending part was considered as maxF.In this Section, the experimental results of the nine TPB tests on notched beams with and without a GFRP bar reinforcement are reported. F) versus the crack mouth opening displacement (CMOD) responses of all the specimens without a GFRP bar reinforcement. F-CMOD responses of the four notched beams with a GFRP bar reinforcement. A call out of the initial portion of the response is also provided in maxF).maxF. It can be assumed that in the post-peak ascending part of the test, the variation of the force in the GFRP bar with respect to the CMOD is higher when compared to the same variation in the preceding part of the response. For PN_B_1 and PN_B_2, the tests were stopped due to safety reasons when the supporting cylinders reached the outer edge of the steel bearing plates. PN_B_3 and PN_B_4 tests were stopped even earlier due to some technical issues.The post-peak behavior of the CN_X and PN_X specimens features a descending portion characterized by a long tail until the test was stopped at almost zero load. The responses for CN_X and PN_X specimens are consistent with each other, which indicates that casting rather than sawing the notch had no effect. For the PN_B_X specimens, the post-peak behavior shows a descending part followed by an ascending part that starts, on average, at 66% of F) versus the load point displacement (Δ) response for the CN_X and PN_X specimens and PN_B_X specimens, respectively.Specimen PN_B_1 was also stopped earlier (CMOD ~ 2.2 mm) due to the same technical issues; however, it was retested further in stroke control. F-Δ responses of different groups of specimens show slightly different initial slopes from each other. This inconsistency in the F-Δ responses might be originating partly from small adjustments of the specimens and from rotation of the LVDT holders during the test. This kind of trend was observed in previous works [The us works . For somIt should be mentioned that during the PN_B_1 retest, the LVDTs that measured Δ were not used due to some technical issues. F-CMOD and F-Δ responses, respectively, for all the specimens. From F versus CMOD and F versus the left and right free end slips of the bar ξR and ξL, respectively. ξR and ξL are plotted separately to visualize the different behavior of each portion of the bar separated by the bond breaker at midspan.Specimens PN_B_2 and PN_B_3 were equipped with two LVDTs attached to the protruding part of the GFRP bar beyond the concrete beam end cross-sections to measure the free end slip of the bar with respect to concrete. A similar measurement was achieved in the pull-out tests recently published by the authors . Figure R > ξL for the same load level. However, when F > 33 kN, the F-ξR and F-ξL show a different trend. The change in the response seems to be associated with the end of the almost-linear part of the ascending part of the F-CMOD response described above. Eventually, at the end of the test, the left free end of the bar exhibited larger slips compared to the right end. In F, ξR, and ξL are plotted against the CMOD. R-CMOD and ξL-CMOD responses have an initial linear portion followed by a nonlinear response that match with the F-CMOD linear and nonlinear responses in the post-peak ascending part. F-CMOD response. This observation supports the previous statement regarding the bar engagement in the post-peak descending part. It is reasonable to assume that the contribution of the bar to the load bearing capacity of the notched beam before the peak is limited.In Digital image correlation (DIC) was used on five out of nine notched beam specimens to obtain the displacement field and, eventually, the strain field on one of the longitudinal side faces of the specimens . To perfF-Δ responses were obtained from the DIC analysis by using the displacement field. The load point displacement (Δ) was computed by subtracting the average of the vertical displacements at the supports from the vertical displacement at the point of loading [F-Δ responses from DIC analysis for all the specimens. In the call out of F-Δ responses from LVDTs, as pointed out earlier when referring to F-Δ responses from DIC analyses are compared with the F-Δ responses from LVDTs to show the difference between the responses for specimens CN_2 and PN_B_3. These plots show that the LVDT displacements were larger than those from DIC due to the previously mentioned reasons. Researchers have argued that the computation of the vertical displacement considering the location just underneath the loading point can be misleading due to stress concentration [F-Δ responses are reconstructed for each combination of squares for specimens CN_2 and PN_B_3 in F-Δ responses. loading . The verntration . SimilarmaxF). However, the crack started to propagate in the descending part of the load response. For the CN_X and PN_X specimens, crack propagation was associated with a long tail in the post-peak descending part of the load response. The test was stopped when the load was approximately 4% of maxF. For the PN_B_X specimens, the larger values of the CMOD in the post-peak ascending part of the responses (when compared to CN_X and PN_X specimens) were due to the bridging action of the GFRP bar and the possibility of carrying tensile stresses by the bar itself.For all the specimens, micro-damage occurred at the tip of the notch before attaining the peak load  for all the CN_X and PN_X specimens. However, the crack paths were slightly tortuous for the PN_B_X specimens . For PN_Most of the fracture surfaces of the CN_X and PN_X specimens were still wet after the test; however, the fracture surfaces of specimens CN_1 and PN_1 were slightly drier compared to the other specimens, although not fully dry. In The effect of the moisture content on the fracture behavior of concrete is discussed in . The fraThe results presented in this paper and the following analysis refer to a specific type of bar. Further research is needed to investigate the bond behavior of FRP bars with different mechanical and physical properties .FG) was computed using the area under the F-Δ curve [F0) of the specimens was taken into account [FW is the area under the F-Δ curve after adjusting for the self-weight, and a0/D. To compute FG correctly, the end of the tail (to zero load) is required. However, practically, it is not possible to run the test until the load is zero, since the notched beam would break down before it reaches zero load. To tackle this problem, the end tail portion of the response was extrapolated by using the function Y is the load, X is the load point displacement, and a and b are constants that are calibrated by fitting the existing experimental part of the tail response. The fracture energy (FG) for the series CN_X and PN_X is reported in For the CN_X and PN_X specimens, the fracture energy GF=WFF-CMOD response using the following formula [Vβ(α0) is a dimensionless function that depends on α0 andS/D. For all specimens in this paper, β = 3. The elastic modulus (ECMOD) was computed for all the specimens and reported in ECMOD values between the CN_X and PN_X specimens again proves that casting the notch rather than saw cutting it did not have any impact on the fracture properties of the specimens. Moreover, the elastic modulus values of the PN_B_X series specimens are also consistent with the CN_X and PN_X specimens, which, again, indicates that in the first linear part of the response, there is a limited effect of the GFRP bar.The elastic modulus was computed from the initial linear elastic part (30% to 60% of the peak load) of the  formula :(3)CMOD=xx and displacement Δxu profiles along the notch ligament are discussed. These profiles were obtained from the DIC analysis. The Cartesian coordinate system shown in xx profile was constructed by averaging the values of the horizontal strain component within square areas along the ligament of the notch. The size of the squares was 5 mm by 5 mm. The average horizontal strain within the square was computed and plotted against the normalized values of y, i.e., y/(D − a0), corresponding to the centroid of the square.In this Section, the horizontal strain εF-Δ responses from DIC and LVDT for specimen PN_B_3. xx profile for the same specimen. The different colored curves correspond to different loading points shown with the same-color circled markers in the F-Δ response from DIC reported in t) value corresponding to the tensile strength of concrete. εt was computed asECMOD for all specimens reported in t was equal to 0.000159. In t vertical dashed line at y/(D − a0) = 0.42, which is marked with a red square marker. This normalized y value indicates the normalized length of the fracture process zone (FPZ) at the peak load [t line indicates the length of the FPZ for the corresponding load points. xx profile provides the location of the neutral axis for the corresponding load point. It should be mentioned that strain profiles corresponding to points of the load response in the post-peak ascending part were deemed unnecessary, as the neutral axis was basically almost coincident with the outermost fibers of the beam. As the neutral axis reached the outermost fibers on top, averaging the strain over the square provided values of the strain component εxx that were not representative of the actual strain near the top fibers because of the complexity of the stress state. xu profiles for specimen PN_B_3. Δxu was computed by taking two squares on each side of the notch tip. The side of the squares was 5 mm. The squares were placed 10 mm apart on center. The averages of the horizontal displacements within the squares were then computed and subtracted from each other to obtain Δxu. This process was performed along the whole ligament and then plotted against the normalized value of y. The different colored curves in x,eu.eak load . Similarxu. The value of the Δx,eu was equal to 0.0031 mm. In x,eu at y/(D − a0) = 0.43, which, again, indicates the size of the FPZ for that load. It is observed that the sizes of the FPZ at the peak load determined from the εxx and Δxu profiles are consistent. This consistency between these two profiles can also be found for the other load points as well. At the beginning of the post-peak ascending part of the response of The maximum elastic elongation was computed asxx and Δxu profiles were constructed for specimen CN_2 and are reported along with the F-Δ response from DIC in xx profile, and it was y/(D − a0) = 0.36 for CN_2. A similar size of the FPZ at the peak load was obtained from the Δxu profile. The size of the FPZ at the peak load for specimens CN_2 is slightly smaller than that of specimen PN_B_3. To further study the effect of the GFRP bar on the size of the FPZ at the peak, the εxx and Δxu profiles corresponding to the peak load for all specimens  are plotted together in The εbarP) in the PN_B_X specimens was computed using the moment equilibrium [C and T1, respectively. The cohesive zone was defined using Petersson’s bilinear softening curve [T2 and T3.The force in the GFRP bar  at the beginning of the bonded area was determined from DIC analysis. The difference of the horizontal displacements between the two points on each side of the notch corresponding to the beginning of the bonded areas was named Δlu and was obtained from DIC analysis. Two squares (10 mm side) on each side of the notch where the bond breaker ended were used to average the horizontal displacements. The difference of the averages of the displacements corresponded to Δlu. The slip g was then obtained by subtracting the elastic deformation of the bar from Δlu and assuming an equal slip on each side of the notch:The beginning of the cohesive zone was found as the intersection of the εng curve . Δux wasl is the length of the unbonded length due to the presence of the bond breakers.As noted above, barP) versus the slip g for the three PN_B_X specimens for which DIC analysis was available. P versus the loaded end slip g from three pull-out tests of the same GFRP bar embedded in concrete cylinders. These plots refer to an experimental campaign conducted by the authors to study the effect of the bonded length in pull-out tests of GFRP bars [FRP bars . The diaFRP bars . A schemtop plate. The top plate had a hole at the center to pass the GFRP bar through, and it was connected to another plate on the bottom of the cylinder called the bottom plate. The top plate was connected with the bottom plate by 22 mm diameter threaded steel bars featuring frictionless bearings to reduce torsion. This bottom plate was connected to the jaws of the servo-hydraulic machine by means of a square steel plate and a stud. Three LVDTs were attached to the top part of the GFRP bar (120° apart) at a distance of 130 mm from the top surface of the concrete cylinder. The average of these three LVDTs was used to control the test. The slip g for the pull-out tests was computed by subtracting the GFRP bar deformation (between the LVDTs and the beginning of the bonded area) from the average of the LVDT readings.Threaded hollow cylinders were glued at the top end of the bar to improve the gripping of the GFRP bar by the semi-moon jaws of the servo-hydraulic machine. The concrete cylinder reacted against a 25 mm thick steel plate on the top named the barP versus g plots shows that the responses are in good agreement with each other. Interestingly, the barP versus g response of specimen PN_B_2 indicates that the load in the notched beam increases at a different rate with respect to g when compared to the force in the bar in pull-out tests, which suggests that the pull-out tests could be considered an upper bound in terms of the bond behavior of GFRP bars in structural elements. The reason behind this observation could be the effect of bending that is present in the TPB tests of notched beams, which could imply a non-uniform distribution of the interfacial shear stresses along the perimeter of the bar.The bonded length of the pull-out tests was 240 mm. The bonded length on each side of the notch in the beams was 225 mm. Even though the bonded length in the pull-out test was slightly larger than the bonded length of the GFRP bar in each half of the notched beams, the comparison of the pull-out test responses with the xx) are shown in F-Δ plots in The contour plots of the horizontal strain component  was not affected by whether the notch was cast or saw cut.The computation of the fracture energy The computation of the elastic modulus from the initial linear branch of the load versus CMOD response indicated that the bar had a limited effect on the load response prior to the attainment of the first peak load.The size of the fracture process zone (FPZ) did not seem to be affected by the presence of the GFRP bar.The crack path appeared to be more tortuous for the beams reinforced with the GFRP bar.The force in the bar versus the slip at the beginning of the bonded area in notched beams was compared with the load versus loaded end slip of the pull-out tests. It was concluded that, in terms of the bond behavior, pull-out tests could be assumed as an upper bound with respect to the bond phenomenon in structural elements where bending is present.Three-point bending tests of concrete notched beams with and without a GFRP bar as internal reinforcement were carried out using digital image correlation analysis for some of the specimens. The fracture tests were used to determine the fracture behavior of the beams and the effect of the internal reinforcement on the crack propagation, crack mouth opening displacement (CMOD), and crack pattern. In addition, the load in the bar and the slip at the beginning of the bonded area were determined using DIC and cross-sectional moment equilibrium and compared with the results of the pull-out tests. The notch was cast for specimens with the GFRP bar and either cast or cut for specimens without the bar. The following conclusions can be outlined:


However, this decarbonization pathway is dependent on how CO2 uptake by carbonation and carbon capture and utilization is accounted for in the inventory. Our analysis underscores the importance of including demand-side interventions at the heart of decarbonization strategies and highlights the urgent need to discuss how to account for CO2 uptake in national inventories under the Paris Agreement.Decarbonization strategies for the cement and concrete sector have relied heavily on supply-side technologies, including carbon capture and storage (CCS), masking opportunities for demand-side intervention. Here we show that cross-cutting strategies involving both the supply and demand sides can achieve net-zero emissions by 2050 across the entire Japanese cement and concrete cycle without resorting to mass deployment of CCS. Our analysis shows that a series of mitigation efforts on the supply side can reduce 2050 CO A new study finds supply-side efforts alone are unlikely to lead to net-zero emissions across the cement and concrete cycle by 2050, advocating for more efficient use of cement and concrete in the built environment and more strategic options for decarbonization. A prime example is concrete, the most extensively used human-made material in the world2. The chemical reactions and high temperatures required for the production of cement, the binding agent for making concrete, combined with its mass production and use, make its decarbonization one of our most significant challenges4. The share of CO2 emissions arising from the entire cement and concrete cycle in total global energy-related emissions has been increasing in recent decades5, and is now ~10%7. As scientific knowledge regarding climate change advances8, the key question centers on what actions need to be taken, on what scale, and by when, in order to decarbonize the complete cement and concrete cycle.Compliance with internationally agreed upon climate targets depends to a great extent on how to address hard-to-abate industrial sectors9, clinker-to-cement ratio reduction11, low-carbon fuel utilization12, cement substitution with alternative binders14, carbon capture and storage (CCS)16, and carbon capture and utilization (CCU)17. Among these various supply-side measures, industry pledges and policy discussions are particularly dependent on CCS20, even though it belongs to the lowest hierarchy of strategies due to technology lock-in concerns and low resource efficiency21. In contrast, an emerging research stream has shown that significant, but largely untapped, opportunities exist on the demand side through more efficient material use26. However, these studies do not provide a pathway for achieving net-zero emissions by approximately mid-century, an underlying requirement for meeting the 1.5–2 °C climate target8. Recent literature reviews summarizing the large body of available evidence suggest the importance of cross-cutting strategies that span the entire cement and concrete cycle29; however, relevant empirical analyses remain largely lacking. While several pioneering efforts have been undertaken to fill this gap30, they tend to consider only a limited set of concrete end uses and thus do not capture a large part of concrete flows and stocks.A growing body of evidence has shown the potential for emissions reduction through efforts focusing on the supply side of the cement and concrete cycle, including energy efficiency improvements2 emissions arising from each process, and a physicochemical model that quantifies the CO2 uptake associated with concrete carbonation. This integrated approach allows us to explore strategies to achieve net-zero emissions across the cement and concrete cycle while ensuring a dynamic mass balance of stocks and flows in the system. We apply the model to Japan given its significant CO2 emissions (fifth largest in the world31) and the availability of the types of detailed datasets that are required for such a modeling approach. Japan is one of the few countries globally that provides government-managed, rigorous, and long-term data for construction activity by structure type and material intensity. This study first scrutinizes the historical structure and evolution of the cement and concrete cycle and its associated-CO2 emissions and uptake over a 70-year period, from 1950 to 2019. The proposed model is then used to explore 16 strategies (nine supply-side and seven demand-side interventions) for achieving net-zero emissions by 2050. The principal storyline here focuses on whether it is possible to achieve net-zero emissions across the cement and concrete cycle without relying on CCS, which belongs to the lowest tier of mitigation strategies21.The work presented here addresses these knowledge gaps by characterizing the net-zero emission pathway for the cement and concrete cycle using a cohesive modeling framework. Our approach builds on a dynamic material flow analysis (MFA) model, coupled with an emissions model that tracks CO2 fluxes shown in Fig. 32. Around half of the concrete produced was used for constructing buildings; the other half was used for developing infrastructure. Approximately 2% of concrete was lost as construction waste, which represents concrete that was produced but never included in a final product. In Japan, most demolished concrete is downcycled as road base materials, turned into hibernating stock, or landfilled; thus, there is an almost invisible recycling flow to concrete aggregates.The detailed map of the contemporary cement and concrete cycle and associated-CO2, which is equivalent to ~3% of Japan’s total CO2 emissions. Of this amount, cement production accounts for the largest share (83%), followed by transportation (9%) and on-site concrete placement (5%). Despite a large production volume, the share of CO2 emissions from aggregate production is only 2%. The CO2 uptake by concrete carbonation reached 8.2 Mt-CO2 (7.1-10.0 Mt-CO2 interquartile range) in 2019, equivalent to about 24% of concrete-related emissions and ~1% of Japan’s total emissions. In-use stocks act as the largest sink during the service life of buildings and/or infrastructure, absorbing 74% of the total uptake. Another 22% is derived from demolition waste at the end-of-life stage, and the remaining 4% from cement kiln dust and construction waste . Therefore, the long-term evolutionary pattern of in-use stock provides insights into the future development path of the cement and concrete cycle. Historically, in-use concrete stock continued to increase throughout the twentieth century, reaching ~15 Gt, or 115 t per capita, in 2000 , respectively. Importantly, however, even if all of these measures are implemented, the collective mitigation potential is only ~80%, which is 20% short of achieving net-zero emissions. This reflects the fact that emerging supply-side strategies are limited in their potential by the applicable concrete strength class and the availability of industrial waste, suggesting the need for complementary measures.The remaining 20% mitigation gap could be filled by more efficient use of cement and concrete in the built environment through multi-stakeholder actions. Material-efficient design, including performance-based concrete design, use of precast concrete components, post-tensioning, and avoidance of over-design, could bring about additional emissions mitigation of 9% by 2050. Another 11% mitigation could be achieved through more intensive use of buildings and infrastructure, through such means as enhanced sharing practices and consolidation of urban functions. These efforts, together with the supply-side strategies, put us within reach of net-zero emissions. Extending the service life of buildings and infrastructure further provides additional mitigation of 4%, enabling even deeper and faster decarbonization. Construction waste reduction, component reuse, downcycling, and stockpiling of demolition waste together all play a limited role in emissions reduction, but harmonize circular economy principles with deep decarbonization of the sector. Overall, our analysis reveals that it is technically possible to achieve net-zero emissions across the cement and concrete cycle by 2050 through the rapid and ambitious implementation of all the supply- and demand-side strategies spanning the entire value chain.2 emissions and uptake, both of which change depending on strategy implementation  far exceed CO2 uptake and storage by natural carbonation and CCUs (−7 Mt-CO2), resulting in net positive CO2 fluxes in 2050 (4 Mt-CO2). With both supply- and demand-side strategies in place, 2050 CO2 emissions could be reduced more deeply (4 Mt-CO2). Thus, the residual emissions are fully offset by CO2 uptake and storage (−5 Mt-CO2), providing net negative CO2 fluxes (−1 Mt-CO2) across the entire cement and concrete cycle. This condition refers to a state in which emissions associated with production activities are balanced by system-wide uptake and storage, mainly from in-use stock and demolition waste brought about by past cement and concrete production.It is important to note that net-zero emissions, as defined here, refer to a state of equal COion Fig. . With su33 these findings imply the need for absolute decoupling of in-use stocks as well, rather than the relative decoupling due to stock saturation phenomenon observed in several high-income countries  can add compelling reasons for stakeholders to build materially efficient buildings and urban structures. The newly enacted subsidy program for life-cycle carbon-minus houses is innovative in that it includes embodied carbon in the assessment43. However, since only the use of blast furnace slag-containing cement and lifetime extension are explicitly mentioned in the material-related efforts, adjustments will need to be made to encourage more diversified demand-side strategies. The key here is to recognize that the amount of cement and concrete that can be produced and used in a net-zero future is not infinite, and that it is considerably less than current levels. This means that stock growth and turnover must be managed simultaneously so as not to induce excessive use of low or zero carbon materials44.Despite the importance of demand-side strategies, there is absolutely no incentive for the materials industry to promote efficient material use, since the current profits are directly related to the volume of materials sold. More importantly, purchases of cement and concrete currently account for less than 10% of total spending in the building and infrastructure construction sector, suggesting the existence of weak economic incentives to pursue material efficiency, even on the demand side  coordinated policies to raise awareness of the importance of demand-side strategies, (2) revised material flow-related targets that are consistent with national commitments to climate change, and (3) consensus in the accounting methods used to assess CO48, assuming the specific lifetime of each end-use category. More specifically, this is a time-cohort-type approach that derives the in-use concrete stocks from the sum of the concrete inflows embedded in surviving buildings and infrastructure each year. Thus, the in-use stock of concrete is defined as the apparent quantity of material in buildings and infrastructure that are in-use in any given year. Note that since the focus of this study is on domestic demand, international trade is not taken into account here.The analysis begins with a comprehensive understanding of the historical cement and concrete cycle, which is poorly understood due to fragmented statistical data. This challenge is addressed using a systems model encompassing a series of life-cycle stages, including raw material extraction, processing, manufacturing, in-use stocks, demolition, and recycling. The model first quantifies the flow and stock of concrete, based on construction activities and structure-specific material intensities, and then relates them to other material uses such as cement, clinker, aggregates, and water. The basis of the model is the law of mass conservation, which describes the structure and dynamic changes of material flows and stocks over time and space by a series of mass balance equations. The in-use stock of concrete is estimated using the inflow-driven dynamic MFAThis study considers 11 end-use categories of concrete based on national official statistics: (i) residential buildings; (ii) non-residential buildings; (iii) roads; (iv) landslide and flood control; (v) agriculture, forestry and fisheries; (vi) industrial water; (vii) sewerage; (viii) harbors and airports; (x) railways and telecommunications, (xi) parks; and (xii) waste treatment. In this study, residential and non-residential buildings are further broken down into six sub-categories according to structure type: wood, steel-reinforced concrete, reinforced concrete, steel frame, concrete block, and others. System variables and parameters are determined by aggregating various fragmented statistical data on cement, ready-mixed concrete, aggregates, building, infrastructure, and material intensities. Some data are supplemented with information from previous MFA studies and interviews with industry representatives. A more detailed description of the modeling procedures and data sources is provided in Section 1.1 in the Supplementary Information.2 emissions associated with the cement and concrete cycle are calculated based on a comprehensive dataset documenting energy consumption and emission factors used in each process. This approach allows us to track the CO2 emissions associated with electrical and thermal energy consumption, and chemical reactions (the conversion CaCO32 in the kiln) over the entire concrete cycle. The emission sources considered in this study are roughly divided into six major categories: cement production, virgin aggregate production, recycled aggregate production, concrete mixing and batching, concrete on-site placement, and transportation activities. Emissions from the use and dismantling phases are excluded from the model as it is difficult to assign them to a single material. A Japan-specific dataset on the energy consumed and the emissions generated in each process is compiled based on various statistical data and national emission inventories  as a final demand sector rather than as inputs to the production system54. Consequently, the typical input-output analysis does not tell us which final demand is really driving the use of construction materials, including cement and concrete, which are used mainly in the production of fixed capital stocks. We, therefore, endogenize fixed capital by using an augmentation method55 with the fixed capital formation table in the supplementary material of the Japanese input-output table. Please see Section 1.4 and Supplementary Table The process-based MFA described above only captures the material flows for each broad application category, such as buildings, and does not provide any insights into what final demand actually drives them. For example, non-residential buildings can be used as schools or hospitals to meet needs for education or medical services. Thus, to better understand the demand-side drivers of the current cement and concrete cycle, we link estimated material flow data to final demand drivers based on the input-output approach. Specifically, cement flows in 2019 are linked to ~400 sectors using the 2015 Japanese input-output table, which is the most recent data currently available48. Ultimately, using material intensity data for each application, dynamic changes in the flow and stock of buildings and infrastructure can be tied to a series of concrete and associated resource uses.The future concrete flows and stocks are explored and tied with building and infrastructure stock dynamics. In this approach, future per capita building floor space and infrastructure stock are first estimated based on historical observations. A stock-driven dynamic MFA then translates them into newly constructed buildings and infrastructure2 emission mitigation potential of additional strategies. The future population is based on the Shared Socioeconomic Pathway 2, representing a “middle-of-the-road” pathway with moderate population and GDP growth56.We define a baseline scenario as a future in which the way that buildings and infrastructure are manufactured, used, and demolished remains unchanged. This scenario is based on the observation that per capita building floor space and infrastructure stock have been stable since around 2010 , emerging supply-side strategies (three strategies), and demand-side strategies (seven strategies). A brief description of each strategy group is given below, with detailed technical descriptions, assumed parameters, and barriers to implementation to be found in Section 3 of the Supplementary Information.2 emissions. Such measures include improving thermal and electrical efficiency, using low-carbon fuels, reducing clinker-to-cement ratios, lowering transportation emissions, and decarbonizing the electricity supply. The technological potential of these strategies is determined based on best practices from around the world and the long-term vision of the industry to reflect an ambitious, but not unfeasible level of implementation. Although the speed of diffusion of each strategy is influenced by multiple factors, including political and regulatory procedures, infrastructure development, and information accumulation, for simplicity, the speed of implementation is modeled assuming linear growth from 2021 to 205037.Strategies in this category are envisioned to enhance current efforts by industries to reduce CO7 reactive belite cement, belite-ye’elimite-ferrite cement, carbonatable calcium silicate cement, calcium sulfoaluminate, Celitement, and magnesium oxides derived from magnesium silicates. As for CCU, there are two types of CCU to be considered: “concrete curing”, where CO2 gas is injected during the batching and mixing of concrete or during the curing process of precast products, and “mineralization”, where CO2 is mineralized with alkaline substances such as calcium and magnesium to form carbonate minerals. CCU technologies mitigate CO2 emissions through increased CO2 uptake and storage over the service life of the concrete and reduced binder due to an increase in the compressive strength of concrete. The technical potential of these strategies is established based on the applicable strength classes and the availability of industrial wastes. Based on the government’s roadmap57 and a detailed technical review7, the speed of implementation is assumed to be through linear growth from 2030 to 2050.This category includes innovative supply-side interventions, but could take a little time to scale up: using low-carbon cement chemistries and CCUs. We consider six low-carbon cement chemistries that have been identified as being commercially viable in the next decade or so:59. Modeling of its effects requires going beyond the study of a single material and tracing a set of materials together, for example, building materials24. The technical potential of each strategy is set based on various scientific studies. Since strategies in this category can be implemented immediately23, implementation is envisioned to begin in 2021, as is the case with conventional supply-side strategies.Material efficiency strategies refer to demand-side interventions by systems and actors that use concrete in the built environment, such as architects, urban planners, property owners, constructors, general consumers, and waste processors. A total of seven interventions across the cement and concrete cycle are considered here: material-efficient design, construction waste reduction, more intensive use, lifetime extension, component reuse, downcycling, and stockpiling of demolition waste. Since our focus is on the cement and concrete cycle, we do not consider material substitution with, for example, engineered woodIt is important to note that the demand-side strategies considered here are not independent and that they influence each other. A prominent example is the strategies related to lifetime extension and several end-of-life options: the longer a concrete structure lasts through lifetime extension, the less end-of-life material is available for component reuse, downcycling, or waste stockpiling. Our model captures such interactions through a set of mass balance equations that ensure the feasibility of each strategy in terms of mass balance constraints. The interaction of strategies that do not depend on mass balance constraints is further explained in Section 3 of the Supplementary Information.2 emissions when the implementation level of demand-side strategies and the percentage of kiln capacity equipped with CCS are varied from 0% to 100% in 10% intervals. Thus, a total of 121 different scenarios are investigated. In this case, three possible types of CCS can be used in kilns: oxy-fuel firing, pre-combustion, and post-combustion, where CO2 is separated and captured during combustion, pre-combustion, and post-combustion, respectively. Here, the implementation of post-combustion with chemical absorption is determined by referring to the literature60, taking into account its capture efficiency (90%) and energy penalty (2070 MJ/t-CO2 captured)61.While this study sets out to explore a net-zero emission scenario that does not rely on CCS, the role of CCS is investigated in the manner of a sensitivity analysis. Doing so allows us to better understand how demand-side strategies can reduce reliance on CCS. Specifically, we quantify the extent to which different implementation levels of demand-side strategies reduce dependence on CCS. This is done by estimating the net COSupplementary InformationPeer Review File


Epinephelusrankini, described from the waters off Western Australia, has long been regarded as a junior synonym of Epinephelusmultinotatus. However, the two species are discernible as distinct species on the basis of their morphological characteristics and genetic differences by the holotype material and non-type of specimens.The grouper Epinephelusrankini is considered as a valid species and re-described based on the examination of the holotype and additional specimens. Epinephelusrankini can be distinguished from the closely-related species E.multinotatus by the following combination of characters: body dark greyish-brown to chocolate with irregular white blotches , absence of small dark brown spots . Furthermore, genetic differences between the two species strongly support the validity of both species based on molecular analysis . In addition based on the sampling range, E.rankini was observed range from the Abrolhos Islands of Western Australia to south-eastern Indonesia, while E.multinotatus ranges from the Persian Gulf to southern Mozambique.In this study,  Epinephelidae, known as groupers, comprises more than 170 species in 16 genera  is the most diverse, containing approximately 90 valid species    , Epinepheluscraigi , Epinephelustankahkeei  and others being identified as new species  , Epinephr, 1870) , Epinephl, 1842)  being re species . This reEpinephelusrankini Whitley, 1945 was first collected by Mr. F. J. Rankin in the Onslow, Western Australia in late 1944 and then described by Epinephelusmultinotatus   gene] between these two species also strongly support this conclusion. In this paper, we describe the morphological and genetic differences between E.multinotatus and E.rankini and re-describe E.rankini and E.multinotatus as well.uritius) . BetweenE.multinotatus and E.rankini. Specimens of E.rankini from Indonesia and the type locality, as well as specimens of E.multinotatus from Maldives, Seychelles, Africa and Mauritius  were also examined. The sampling information is listed in Suppl. materials E.rankini and E.multinotatus as percentages of standard length are listed in Table Specimens from western Indian Ocean, Western Australia and southeast Indonesia were examined, including the holotypes Fig.  of E.mulE.rankini, E.multinotatus and closely-related species was isolated from fresh dorsal-fin rays using a standard phenol-chloroform protocol and the ethanol precipitation method and then preserved at -20°C. Partial sequences of the mitochondrial COI were amplified using a pair of primers  by polymerase chain reaction (PCR)  . PCR reahttp://www.genecodes.com) software and then the shared 642 bp were extracted from each sequence for subsequent analysis. The intraspecific and interspecific genetic distances were calculated using the Kimura two-parameter (K2P) distance model with MEGA 11  and Epinephelusflavocaeruleus , which clustered with E.multinotatus in the same branch, for analysis together, and Epinepheluschlorostigma  and Epinephelusareolatus , another sister branch that shares a common ancestor with E.multinotatus, as outgroup. The PhyML tree was analysed using the online (http://species.h-its.org/ptp/) version of the programme bPTP . The specific nucleotide substitution is presented in parentheses and the results are presented in the molecular diagnostics section and Suppl. material A total of 34 COI sequences in this study were manually edited using Sequencher 5.4.6 8943166D-DB2D-529F-811A-FBF8FD8361E69A7880BD-7DF2-4F4C-A07B-9371A83FEAF1Type status:Holotype. Occurrence: recordedBy: Whitley; Taxon: taxonID: WAM P.2847-001; scientificNameID: Epinephelusrankini; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; scientificNameAuthorship: ; Location: locality: Western Australian; Record Level: language: en; institutionCode: WAMType status:Paratype. Taxon: scientificNameID: Epinephelusrankini; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Indonesia; Identification: dateIdentified: 2019-4; Record Level: collectionID: ZMUA-epran01; institutionCode: ZMUA; collectionCode: fishType status:Paratype. Taxon: scientificNameID: Epinephelusrankini; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Thevenard Island, Western Australia; Identification: dateIdentified: 2021-11; Record Level: collectionID: ZMUA-epran02; institutionCode: ZMUA; collectionCode: fishType status:Paratype. Taxon: scientificNameID: Epinephelusrankini; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Dirk Hartog Islands, Western Australia; Identification: dateIdentified: 2021-11; Record Level: collectionID: ZMUA-epran03; institutionCode: ZMUA; collectionCode: fishType status:Paratype. Taxon: scientificNameID: Epinephelusrankini; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Indonesia; Identification: dateIdentified: 2021-12; Record Level: collectionID: ZMUA-epran04; institutionCode: ZMUA; collectionCode: fishType status:Paratype. Taxon: scientificNameID: Epinephelusrankini; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Indonesia; Identification: dateIdentified: 2021-11; Event: eventDate: 2006; Record Level: collectionID: ZMUA-epranA; institutionCode: ZMUA; collectionCode: fishType status:Paratype. Taxon: scientificNameID: Epinephelusrankini; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Western Australia; Identification: dateIdentified: 2019-8; Record Level: collectionID: ZMUA-epranB; institutionCode: ZMUA; collectionCode: fishType status:Paratype. Taxon: scientificNameID: Epinephelusrankini; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Western Australia; Identification: dateIdentified: 2019-8; Record Level: collectionID: ZMUA-epranC; institutionCode: ZMUA; collectionCode: fishHead large and head length 2.6 (2.6-2.8) in SL, orbit diameter 6.8 (6.5-6.9) in head; interorbital broadly convex and width 4.5 (4.1-4.5) in head. Snout length 4.08 (3.9-4.2) in head. Mouth large and oblique, length of upper jaw 2.0 (2.0-2.3) in head, maxilla width 7.3 (6.8-7.3) in head, maxillary roundly truncate and extending to rear edge of eye, with small supplemental bone, only visible through dissection.Dorsal fin XI, 16 ~ 17; anal fin III, 8-9; pectoral fin 17–18; pelvic fin I, 5; caudal fin 16-19; lateral-line scales 71-86; lateral scale series 137-163; gill rakers 9-11+14-15; head length 35.3-38.5% SL; eye diameter 5.2-5.7% SL, preorbital length 7.1-7.6% SL and depth 4.3-5.7% SL, interorbital width 7.9-8.6% SL; snout length 8.3-9.4% SL, maxilla width 4.9-5.3% SL, length of upper jaw 15.8-18.9% SL, lower-jaw length 10.1-13.6% SL; body compressed laterally, body depth 34.2-35.3% SL and width 14.9-16.7% SL; predorsal length 30.9-32.6% SL, dorsal-fin base 56.6-58.4% SL, first dorsal spine 4.9-7.2% SL, second dorsal spine 9.9-13.6% SL, longest dorsal spine  10.4-15.5% SL, last dorsal spine 8.6-10.9% SL, longest dorsal ray 11.7-14.7% SL; pre-anal length 63.6-68.0% SL, anal-fin base 7.4-17.1% SL, first anal spine 3.5-4.2% SL, second anal spine 6.5-8.4% SL, third anal spine 8.1-10.2% SL and longest anal ray 14.9-19.2% SL; pectoral-fin length 17.7-19.2% SL; prepelvic length 31.9-36.6% SL, pelvic-fin length 17.4-19.6% SL, pelvic-spine length 9.1-11.1% SL; caudal-fin length 19.3-20.9% SL, caudal-peduncle length 17.1-20.9% SL and depth 10.4-11.5% SL (see Table Epinephelusrankini can clearly be distinguished from most of its congers by the absence of bars and bands in head and body (vs. presence) and diagnosed from confusable species by the following combination of characteristics: head, body and fins black greyish-brown to chocolate with irregular white blotches  ; absence of small dark brown spots ; the lateral-line scales 71-86 (vs. 48-51 in Epinephelusclippertonensis Allen and Robertson 1999); lateral-scale series 137-162 (vs. 92-107 E.erythrurus).Epinephelusrankini is diagnosed by a combination of 10 nucleotide substitutions: COI 276 (A→G), COI 279 (C→T), COI 294 (A→G), COI 351 (T→C), COI 399 (A→G), COI 402 (T→C), COI 442 (A→G), COI 519 (A→G), COI 537 (T→C), COI 552 (T→C). In addition, E.rankini possess 24 nucleotide substitutions when compared to E.multinotatus: COI 105 (T→A), COI 198 (T→C), COI 270 (C→T), COI 273 (T→C), COI 276 (A→G), COI 279 (C→T), COI 294 (A→G), COI 297 (C→T), COI 351 (T→C), COI 366 (G→A), COI 399 (A→G), COI 402 (T→C), COI 442 (A→G), COI 444 (A→C), COI 468 (A→G), COI 484 (C→T), COI 519 (A→G), COI 537 (T→C), COI 552 (T→C), COI 561 (G→A), COI 582 (T→C), COI 603 (G→A), COI 618 (C→T), COI 633 (A→G).Black greyish-brown to chocolate with irregular pale white blotches on the head, body and fins, with the blotches on the front of the head, chest and fins smaller and not obvious and those on both the sides of body larger; the rear margins of the unpaired soft rays have an extremely narrow white edge Fig. a, c, e. Body grey to brown with pale white blotches remaining prominent or fading. The narrow white edge on the posterior margin of the unpaired soft rays also remains or fades Fig. c, e. Wit1Epinephelusrankini is known from the Western Australian waters from the Abrolhos Islands northwards to Cape Leveque and south-eastern Indonesia 111248B3-ACFA-59CB-A5BF-A65548C917FAE666A249-758C-448C-B746-A888F43C5E21Type status:Holotype. Taxon: taxonID: ZMB 9452; scientificNameID: Epinephelusmultinotatus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; scientificNameAuthorship: (Peters 1876); Location: locality: MauritiusType status:Paratype. Occurrence: recordNumber: ZMUA-epmul03-05; ZMUA-epmulD,ZMUA-epmulF, ZMUA-epmulG; individualCount: 6; Taxon: scientificNameID: Epinephelusmultinotatus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Maldives; Event: year: 2020; Record Level: institutionCode: ZMUA; collectionCode: fishType status:Paratype. Occurrence: recordNumber: ZMUA-epmul02; ZMUA-epmulE; individualCount: 2; Taxon: scientificNameID: Epinephelusmultinotatus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: South Africa; Event: year: 2019; Record Level: institutionCode: ZMUA; collectionCode: fishType status:Paratype. Occurrence: recordNumber: SAIAB 77354, 80836; individualCount: 2; Taxon: scientificNameID: Epinephelusmultinotatus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Seychelles; Record Level: institutionCode: SAIAB; collectionCode: fishType status:Paratype. Occurrence: recordNumber: SAIAB 19541, 86850, 86834; individualCount: 3; Taxon: scientificNameID: Epinephelusmultinotatus; kingdom: Animalia; phylum: Chordata; class: Actinopterygii; order: Perciformes; family: Epinephelidae; genus: Epinephelus; Location: locality: Mozambique; Record Level: institutionCode: SAIAB; collectionCode: fishHead large and head length 2.2-2.7 in SL, orbit diameter 6.4-7.5 in head; interorbital broadly convex and width 4.1-5.2 in head. Snout length 3.6-4.6 in head. Mouth large and oblique, length of upper jaw 2.2-2.6 in head, maxilla width 7.1-8.6 in head, maxillary roundly truncate and extending to rear edge of eye, with small supplemental bone, only visible through dissection.Dorsal fin XI, 15 ~ 17; anal fin III, 8; pectoral fin 16–20; pelvic fin I, 5; caudal fin 16-18; lateral-line scales 62-77; lateral scale series 130-151; gill rakers 9-11+15-17; head length 36.5-44.8% SL; eye diameter 5.3-6.1% SL, pre-orbital length 7.4-9.2% SL and depth 5.0-5.9% SL, interorbital width 7.4-8.9% SL; snout length 9.1-10.5% SL, maxilla width 5.0-5.3% SL, length of upper jaw 16.3-17.2% SL, lower-jaw length 11.3-12.0% SL; body compressed laterally, body depth 34.4-41.8% SL and width 14.4-19.8% SL; predorsal length 31.7-37.3% SL, dorsal-fin base 50.4-58.6% SL, first dorsal spine 3.5-5.7% SL, second dorsal spine 7.8-12.0% SL, longest dorsal spine  11.3-14.0% SL, last dorsal spine 8.2-9.8% SL, longest dorsal ray 12.7-14.4% SL; pre-anal length 66.7-71.4% SL, anal-fin base 12.8-17.6% SL, first anal spine 2.6-3.5% SL, second anal spine 5.9-6.4% SL, third anal spine 7.8-10.3% SL and longest anal ray 15.9-16.0% SL; pectoral-fin length 17.0-19.3% SL; prepelvic length 30.9-35.7% SL, pelvic-fin length 16.3-19.4% SL, pelvic-spine length 9.7-10.3% SL; caudal-fin length 19.1-23.1% SL, caudal-peduncle length 16.0-20.6% SL and depth 11.3-11.6% SL (see Table Epinephelusmultinotatus can clearly be distinguished from most of its congers by the absence of bars and bands in head and body (vs. presence), presence of numerous small dark reddish-brown spots (vs. absence or spots of other colour) and diagnosed from confusable species by the following combination of characteristics: head and body pale brownish-grey with irregular and small white blotches ; absence of black saddle blotch (vs. presence of black saddle blotch in Epinephelushowlandi Gunther 1873), the lateral-line scales 62-77 (vs. 48-51 in E.bontoides), lateral-scale series 130-151 .Epinephelusmultinotatus is diagnosed by a combination of 10 nucleotide substitutions: COI 105 (T→A), COI 198 (C→T), COI 270 (T→C), COI 273 (C→T), COI 366 (A→G), COI 484 (C→T), COI 561 (A→G), COI 582 (C→T), COI 618 (T→C), COI 633 (G→A).Pale brownish-grey with irregular and small white blotches above the head and body, and numerous small dark reddish-brown spots below the head and body, sometimes spread all over the body Fig. 22d. The rHead and body pale brownish-grey with white blotches and small dark spots remaining prominent or fading. With prolonged storage time, the body colour gradually turns pale yellowish-brown and the blotches and spots fade Figs b, 2d.2Epinephelusmultinotatus is known from the Persian Gulf to southern Mozambique and also found in the island States   Fig. . JuvenilCOI gene sequences of E.rankini and closely-related species were sequenced or obtained from GenBank in this study. The intraspecific mean distance of E.rankini was 0.0023. The Kimura 2-parameter interspecific distances indicated that E.rankini differs from E.multinotatus by 0.0424, from E.flavocaeruleus by 0.0421, from E.cyanopodus by 0.0439, from E.chlorostigma by 0.0577 and from E.areolatus by 0.0753  and the specimens of E.rankini and E.multinotatus clustered into group 1 and group 2, respectively  is a western Indian Ocean species with a recorded maximum total length (TL) of 100 cm and was previously reported to be distributed from the Persian Gulf to southern Mozambique and eastwards to Western Australia , but encountered the same fate as E.rankini, becoming a synonym of E.multinotatus from the Arabian Gulf and Oman region  between E.rankini and E.flavocaeruleus, that (0.0260) between Epinephelusbruneus (Bloch 1793) and E.moara  and E.geoffroyi , which is consistent with the results obtained by E.flavocaeruleus and E.cyanopodus into the same group, supporting that they are possible synonyms. Epinephelusflavocaeruleus and E.cyanopodus are considered two valid species due to differences in the body colour pattern and geographical distribution Detailed result of the ABGD analysis (Data typeSequence analysis resultsFile: oo_752706.docxhttps://binary.pensoft.net/file/752706Xiaoying Cao, Haohao Wu, Haoran Zhang, Lina Wu, Shaoxiong Ding


The manufacture of elements containing two types of concrete allows for the minimization of the amount of Portland cement by matching the properties of concrete with local structural and durability requirements. The most common production method of the hybrid element is wet–on–hard and wet–on–wet. Casting wet–on–dry is the most common approach while casting wet–on–wet has been used mostly for concrete overlays and screeds. The study focuses on the wet–on–wet method but is applied in the production of vertical and horizontal elements. Bond-behavior and micro properties of the wet–on–wet casting interface of ultra–high–performance concrete (UHPC)–normal strength concretes are investigated. The obtained results indicate the formation of a hybrid interfacial transition zone between the two types of casted concrete. The binder matrix located in this zone appeared to combine properties of both used concrete. Porosity, phase composition, and presumably also strength, changed gradually. Furthermore, despite significant differences in shrinkage, no microcracking or delamination was observed in that zone. The ultimate flexural and compressive strength of the produced elements were either equal to the stronger concrete or were higher than the weaker of the used concrete. A partial replacement of Portland cement with secondary cementitious material (SCM) can reduce the CO2 footprint. Typical SCMs include fly ash, blast furnace slag (BFS), and calcined clay [The annual production of concrete exceeds 30 billion tons worldwide . The majned clay ,5,6. Mosned clay . Howeverned clay .2 footprint, but having insufficient frost durability, with an external layer made of UHPC or HPC [Structural elements such as walls, slabs, and columns exposed to severe environmental conditions and high structural loads can be strengthened by combining UHPC with normal strength/ecological concrete. The combination could include, for example, concrete with a very low COC or HPC ,10. BruhC or HPC . RetrofiC or HPC . Two casC or HPC . In bothC or HPC ,15,16,17C or HPC  concludeC or HPC  studied C or HPC . Others C or HPC , when thC or HPC . In the Previous studies on the wet–on–wet method focus on the mechanical properties ,22,23. TFurthermore, more research and investigation should be added to understand how the hydration process affects the interface microstructure and how it is reflected in the macro bonding performance of the hybrid concrete casted on wet–on–wet.As shown the number of studies related to the wet–on–wet method is rather limited. Understanding the hydration process that takes place in the interface is important due to its effects on the interface. The focus of this study was the determination of the phase composition and microstructure of the binder matrix forming in the interface zone between two-cast wet–on–wet concretes. Additionally, their effect on selected mechanical properties of elements made of hybrid concrete was evaluated.Six combinations of four types of concretes have been used. Including normal strength concrete (NSC), blast furnace slag concrete (BFSC), and ultra–high–performance concrete with (UHPFRC) and without fibers (UHPC). Test samples were cast in vertical or horizontal layers.Portland cement type CEM I 42.5N (Anläggningscement) used was produced by “Cementa” . Ground granulated blast furnace slag (BFS), type merit 5000  used was provided by SweCem . The maximum granite aggregate size used was 8 mm. The OPC to BFS ratio was 50:50. The UHPC concrete contained Portland cement CEMI 42.5N, condensed micro-silica 920D from Elkem , limestone powder “Nordkalk Limus 40” from Nordkalk AB, Norquartz 45 from Sibelco Nordic  as well as micro sand B15 (150 µm) and B35 (350 µm) provided by Baskarpsand AB . A polycarboxylate-based superplasticizer type “MasterGlenium ACE 30” from BASF  was added to all mixes. Steel fibers having lengths of 7 mm and 13 mm were provided by Krampe Harex-Germany . The chemical composition of dry materials used is determined by ICP–SFMS (Inductively coupled plasma mass spectroscopy-sector field) as shown in 3. In the case of the BFSC, a replacement of 50% by weight of Portland cement is made with slag. The ultra-high performance contains 680 kg/m3 Portland cement and had a w/c = 0.3. In the UHPFRC, 20% of steel fibers by cement weight are added to the mix composition. Based on the proportion of fine grains in each of the mix compositions without changing the w/c ratio, different amounts of superplasticizer were adjusted to reach the desired workability [The mixed proportion of concretes used is summarized in kability ,28. All 3 and 100 × 100 × 100 mm3.Two concretes to be cast into the hybrid element were prepared almost at the same time and left stationary until placing in formwork occurred. Molds were marked to define the heights of the bottom and upper layers in a horizontal arrangement and the length in the vertical as shown in The vertical arrangement consisted of two concretes poured simultaneously against a removable plastic lifting plate. The plate was removed after the completion of pouring. No vibration was used after the plate removal. The horizontal arrangement was cast in two layers without using any separating plate. Since the setting of UHPC was longer than NC , the hybSix types of combinations of different types of concrete were made. To mark the hybrid concrete, the following symbols shown in The rheological properties of fresh concrete were evaluated by using a slump flow test by following the SS-EN 12350-8:2019 standard .The microstructure of the ITZ was analyzed using a digital microscope and Scanning Electron Microscope (SEM)–type Jeol JSM-IT100  coupled with energy-dispersive spectrometry (EDS) from Bruker . For the analysis, a part of the interface was cut from 28-day test cubes, where the examined surface was perpendicular to the top surface of the cube . The corThe distribution of porosity as a function of the distance from the interface was estimated based on the SEM images using the image analysis software from ImageJ. All images were taken at a magnification of 1000 times at various locations and distances from the transition zone, as shown in The Gaussian filter was applied to each of the selected areas to reduce the noise and enhance the contrast between the various hydration phases and pores . The thr3 was used. The 28-day flexural strength was determined by following the SS-EN12390-5 “Testing hardened concrete–Part 5: Flexural strength of test specimens” [3 was used.Mechanical properties were assessed based on compressive and flexural strength measurements at 28 days of sampling. The 28-day compressive strength was determined by following the SS-EN 12390-3 “Testing hardened concrete–Part 3: Compressive strength of test specimens” . For eacecimens” . For eacThe recorded slump and slump flow values varied between 25 and 720 mm. The UHPC without fibers achieved the highest slump flow of 720 mm, while the addition of short steel fibers lowered that value to 620 mm. The normal strength concrete had a slump of only 25 mm, as shown in As described earlier, while casting vertical layers, a temporary plate was placed in the mold to separate the two types of concrete during their casting. Shortly after casting, the plate was removed to enable a wet-on-wet connection. Generally, the visual examination of the produced samples after their demolding did not reveal any signs of intermixing. This trend was observed even when the casted concretes had very different workability, for example, fluid-like UPHC and a rather stiff NSC. In all investigated cases the interface appeared as a nearly straight line. Similar results, when casting wet-on-wet, have been observed by others ,40.The situation became significantly more complex when the two layers were casted horizontally to simulate the production of slabs or beams. Here, the fluid UHPC concrete has been cast first, followed by the placement of a stiffer NC concrete, which is shown in Examples of combined images obtained from digital microscope and SEM are shown in The results showed a generally higher amount of unhydrated Portland cement and a lack of coarse aggregates in the case of the UHPC mixes. Both are related to the used mix designs, i.e., higher cement content, the addition of limestone, and lower water-to-cement ratio in comparison with the normal concrete.Two types of transition zones have been identified. The first type was a regular ITZ forming between binder matrix and aggregates, which is known from several earlier studies . In the To study in more detail all types of observed ITZs present in the hybrid concrete, SEM studies at 1000× magnifications have been applied. The investigation focused on microstructure, especially porosity, crack formation, and phase composition.The porosity of the binder matrix was determined directly in the interface zone and in the bulk binder. The bulk binder was assumed not to be affected by the hybrid ITZ and to be located at least 100 µm from the identified interface line. No visible cracks were observed in the interface except for the hybrid N1C2 made of the normal concrete and the blast furnace slag concrete, as shown in . The black areas represent pixels associated with pores. On each studied strip, having a width of 20 µm, three different areas were selected and used to quantify the porosity, which is shown in To obtain the porosity distribution on the interface, the segmentation of images was performed using the ImageJ software, as shown in Figure 7The porosity tended to be higher in the inner layer  compared to the outer layer  of the hybrid concrete, as shown in x-axis and the value of the outer layer on the positive side of the x-axis.The phase composition of the hybrid ITZ was determined by SEM-EDX. All analyzed spots were localized in areas determined as C-S-H based on their grey levels as seen on the SEM-BSE images. Three atomic ratios were calculated and analyzed, i.e., Ca/Si, Al+Fe/Ca, and S/Ca. The results are summarized in 3AH6) [The calculated Ca/Si atomic ratio has been generally higher for the normal strength concretes (N1 and N2) in comparison with the UHPC mixes (U1 and U2) when measured in the bulk binder matrix. These results are related to a lower amount of the formed Portlandite due to the pozzolanic reactions of SF to produce C-S-H gel . The Ca/3AH6) . Thus suMechanical properties were determined based on compressive and flexural strength measurements. The flexural strength was assessed for two casting arrangements, i.e., vertical, and horizontal, as shown in The results of the three-point bending tests performed on samples casted in the vertical arrangement for the UHPC mixes without (U1) and with steel fibers (U2) are shown in Bending test results for the hybrid concretes beams cast in horizontal layers are shown in The 28-day compressive strength of hybrid concretes was determined using vertically cast cubes, The interfacial transition zone formed between two different types of concrete is the key factor, which determines the bond strength and thus the mechanical properties and durability of the casted element structure. The casted interface in the wet–on–wet method when both concrete is poured simultaneously ensured a good bond between the two layers, More research is needed to understand how different properties, e.g., workability or density affect the width of ITZ. Moreover, the used casting technique has an important role in the formed ITZ. For example, variation in the duration of the applied vibration between casted layers should be considered.The hybrid element casted as the wet–on–wet can be a good substitute for the wet–on–hard method. This is due to the good ITZ formed between the layers but also due to the shorter time of the manufacture. There are several practical applications of the hybrid elements such as floors, bridges, columns, and decks that are used to be repaired by the wet–on–hard method to achieve a long life lasting of the structures.○Different workability of combined concretes can result in an uneven interface leading to a lower mechanical strength, especially in the case of horizontally cast layers.○The ITZ formed between two different concretes cast as wet-on-wet differed substantially from the regular ITZ known to form around coarse aggregate particles where the porosity in this area shows a gradual variation. According to the porosity variation, the width of this area is approximately 35 µm.○The binder matrix microstructure and the phase composition tend to transition gradually within the hybrid ITZ.○The observed gradual transition presumably prevented the formation of microcracks due to differential absolute shrinkage values.○The very dense, homogenous, crack-free hybrid ITZ led to the development of excellent mechanical properties. Since the C-S-H gel is mainly responsible for stiffness and strength, the interface of the hybrid concrete has a higher bonding property. None of the observed failures occurred in the hybrid ITZ during flexural strength.Hybrid concretes combining two different types of concretes have been studied. All samples have been produced using the wet-on-wet method. The following conclusions have been formulated:


Antimicrobial resistance is an increasing problem worldwide that has been exacerbated by antibiotic misuse worldwide. Growing antibiotic resistance can be attributed to as well as leads to severe infections, complications, prolonged hospital admissions, and higher mortality. One of the most important goals of administering antimicrobials is to avoid establishing antibiotic resistance during therapy. This can be done by drastically lowering worldwide antimicrobial usage, both in present and future. While current management methods to legislate antimicrobials and educate the healthcare community on the challenges are beneficial, they do not solve the problem of attaining an overall reduction in antimicrobial usage in humans. Application of rapid microbiological diagnostics for identification and antimicrobial susceptibility testing, use of inflammation markers to guide initiation and duration of therapies, reduction of standard antibiotic course durations, individualization of antibiotic treatments, and dosing considering pharmacokinetics are all possible strategies to optimize antibiotic use in everyday clinical practice and reduce the risk of inducing bacterial resistance. Furthermore, to remove any impediments to proper prescribing, strategies to improve antibiotic prescribing and antibiotic stewardship programs should enable clinical reasoning and enhance the prescribing environment. In addition, the well-established association between antimicrobial usage and resistance should motivate efforts to develop antimicrobial treatment regimens that facilitate the evolution of resistance. This review discusses the role of antibiotics, their current application in human medicine, and how the resistance has evolved to the existing antibiotics based on the existing literature. Antibiotics have changed medicine in numerous ways, saving innumerable lives; their discovery was a watershed moment in human history . UnfortuPseudomonas aeruginosa [Antibiotic resistance can be caused by overuse of antibiotics, inappropriate prescribing, poor compliance, extensive agricultural use, poor infection control in hospitals and clinics, and the availability of few new antibiotics . Antibioruginosa . Bacteriruginosa .Antibiotic-resistant bacterial infections are projected to cause over 33,000 fatalities in Europe each year, and antimicrobial resistance is expected to generate 10 million deaths worldwide by 2050 . The comRole of antibiotic resistance in medicine Antibiotic stewardship programs, a collection of strategies, policies, guidelines, or tools aimed at improving antibiotic use, aim to reduce overall antibiotic consumption and inappropriate antibiotic use, which are essential measures to reduce the emergence of resistant bacteria ,8. RecenThe processes, emergence, and diffusion of antibiotic resistance in hospital and community settings have been mapped out using lessons learned from 80 years of clinical antibiotic usage and development . The genBecause well-documented biochemical or genetic alterations fail to explain processes behind antibiotic resistance adequately, it is becoming clear that we need to look at newer, nontraditional mechanisms like epigenetic control. Epigenetic alteration's biological importance in influencing gene expression and other cellular processes is becoming more well acknowledged. Both prokaryotes and eukaryotes are discovering new epigenetic changes, such as phosphorothioation in the bacterial DNA backbone and acetylation of cytidine in eukaryal mRNA -17. AlteStaphylococcus aureus (16.7%) was the most common Gram-positive isolate [Staphylococcus aureus (MRSA) organisms, both were susceptible to erythromycin, and one organism was sensitive to cotrimoxazole, gentamicin, amikacin, and ceftazidime [The study conducted by Peddi and Latha in a rural tertiary hospital setting published in 2021 suggested that  isolate . It was  isolate . The mos isolate . The stutazidime . This shtazidime .Because hospitals vary in size, geography , teaching (vs community), staff antibiotic prescription tendencies, presence or absence of full-time infectious disease physicians, resistance trends, and other factors, antibiotic stewardship programs (ASPs) must differ. One solution is not the answer to all problems. In one hospital, what is a successful ASP intervention is unsuccessful in another . CustomiRapid microbial diagnosticsInfections in the bloodstream are the primary cause of illness and death . TherefoNovel techniques such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have revolutionized clinical microbiology . The comDirect-on-target microdroplet growth assay (DOT-MGA) is a unique method of MALDI-TOF MS to detect antibiotic sensitivity . The bas Klebsiella pneumoniae and Pseudomonas aeruginosa by incubating microdroplets of bacterial suspension with or without antibiotics on a MALDI target surface for a short time to detect bacterial growth and determine its antibiotic sensitivity [Initially, Idelevich et al. developed this technique to assess carbapenem susceptibility insitivity . This tesitivity .Current applicationsLeuconostoc, Fructobacillus, and Lactobacillus species could be recognized to species level [Clustering techniques demonstrate the value of using the complete spectrum and effective classifiers to determine species/strain types that are pretty similar . For exaes level .ClonalityStaphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and β-lactamase strains [Spectral features can also be used to distinguish microbes based on their clonality, such as methicillin-resistant  strains . Also, a strains ,23. Mult strains . The lim strains . It is a strains ,29.Inflammation BiomarkersAntibiotic use and the emergence of resistance have a well-established causal link. The prevalence of multiresistant organisms is higher in individuals receiving long-term antibiotic therapy, and increased fungal infections even in immunocompetent individuals have become a major source of worry . AntibioBiomarkers that represent the immune response of the host may be an appealing technique for predicting the genesis of an inflammatory condition and are intended to offer an assessment of the severity of infection or forecast a difficult course to aid in the selection of the best therapeutic approach and the most appropriate care setting as well as assist the doctor in deciding whether to start or continue antibiotic treatment ,32. WhetWhite blood cells (WBCs) or absolute neutrophil count (ANC), leukocyte surface markers such as CD64 and CD35, soluble diagnostic biomarkers like C-reactive protein (CRP) and procalcitonin, and cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α can be utilized as a diagnostic tool for follow-up or to choose patients who are likely to benefit from a specific treatment. Biomarkers can also be used during therapy follow-up as early indicators of efficacy or treatment toxicity ,32,34.The two most commonly used biomarkers are CRP and procalcitonin . CRP is Procalcitonin-Guided Antibiotic TherapyProcalcitonin (PCT) is a rediscovered biomarker that meets several criteria, particularly when compared to other widely used biomarkers showing greater diagnostic accuracy for various illnesses. PCT is proven helpful in detecting sepsis early and monitoring the antimicrobial treatment plan. PCT can be a beneficial tool for antimicrobial stewardship, and its use can effectively result in a significant decline in antimicrobial therapy administration . NumerouPCT is synthesized in response to endotoxins or mediators, interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6, during bacterial infections and has a strong correlation with the severity and extent of bacterial infections . In addiCompared to C-reactive protein, the biomarker, procalcitonin, shows a more vital and faster modulation for the severity of bacterial infection. As a result, a reasonable decline in procalcitonin concentrations may aid in the earlier discontinuation of antibiotic usage. Furthermore, according to all evidence, procalcitonin-guided treatment can shorten antibiotic treatment times. This is possible even in a relatively brief antibiotic treatment period. However, it is unclear whether the procalcitonin assay will be cost-effective .The average concentration of PCT in human serum is less than 0.1 ng/ml. Individuals with clinical symptoms of lower respiratory tract infection (LRTI) and patients with clinical signs of sepsis have different PCT strategies. Patients with LRTI can stop taking antibiotics if their PCT level is less than 0.25 ng/ml, while patients with sepsis can stop taking antibiotics if their PCT level is less than 0.50 ng/ml. Furthermore, a drop in PCT of 80% or more from the peak level necessitates antibiotic withdrawal for both situations. Every 24 to 48 hours, PCT levels are usually taken. If the baseline PCT level is below the antibiotic termination threshold, a repeat measurement within six to 24 hours is indicated to account for patients who have a late PCT peak. It is vital to remember that PCT levels should always be evaluated using clinical evaluations and other laboratory indicators. Antimicrobial therapy decisions should not be based solely on PCT levels . The conMeta-analysis findings indicated that patients randomized to PCT procedures had much lower antibiotic exposure and related side effects, with a reduction in antibiotic initiation from 86% to 72% and overall exposure from 8.1 to 5.7 days. Antibiotic side effects reduced from 22.1% to 16.3% . While aThe BRAHMS LUMI  test, employed in older diagnostic investigations to detect PCT levels, has a low sensitivity and is less likely to be utilized in clinical settings. Therefore, newer PCT testing solutions have recently been introduced, including the KRYPTOR ; VIDAS system , Liaison BRAHMS PCT , and Elecsys' BRAHMS PCT   have exhLimitationsEvery PCT measurement has limitations, including false-positive and false-negative outcomes. Different infections may elicit different responses, resulting in varying increases in circulating PCT levels. For example, patients with pneumococcal community-acquired pneumonia (CAP) had high PCT levels; however, this was not the case in CAP caused by atypical organisms like mycoplasma. In addition, antimicrobial pretreatment may influence PCT levels, resulting in reduced levels . PatientNewer BiomarkersNewer biomarkers including the soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), soluble urokinase-type plasminogen receptor (suPAR), proadrenomedullin (ProADM), and presepsin indicate that they could play a role in future clinical advances, whether as diagnostic tests, categorization of patients by kind of injury or severity, or assessment of therapeutic activity and efficacy, and during patient follow-up. Presepsin is the most sensitive and specific of the four biomarkers, and it may help distinguish systemic inflammatory response syndrome (SIRS) from sepsis caused by bacterial infection .Micro-RNAs (miR) are a new class of biomarkers recently found. MiRs are tiny molecules (approximately 20 nucleotides) found in eukaryotic cells that modulate post-transcriptional regulation as biologic regulators. Reverse transcription-polymerase chain reaction (RT-PCR) and quantitative PCR can be used to determine their expression. MiR-150, miR-182, and miR-342-5p are the three most dysregulated miRs; miR-150 inhibits lymphocyte immune response development and can be used as an early diagnostic or prognostic marker .Duration of Antibiotic Therapies to Reduce Bacterial ResistanceTraditional antibiotic therapy durations are based on the fact that a week equals seven days, which is why tried-and-true antibiotic regimens are seven to 14 days long. As a result, more time was not better. Furthermore, patients who took longer courses experienced much more significant adverse effects, indicating that longer is worse. Each additional day of antibiotic medication elevated the probability of an unfavorable event by a startling 5%. Importantly, and in line with prior randomized control trials (RCTs), patients who received lengthier antibiotic courses did not have higher survival rates, lower readmission rates, or fewer emergency department visits . CurrentA recent study found that in patients who had previously used antibiotics intermittently, the therapy was less effective than in those who had only used them occasionally ,48. ThisThis can be accomplished by prescribing the shortest course of treatment , even if it requires the pharmacist to break the box. For example, when antibiotics are administered, the duration (or the number of medications) should be indicated on the prescription, allowing the pharmacist to deliver only the amount of tablets or capsules needed (even if this involves breaking the antibiotic pack), preventing overuse of antibiotics .Choosing the Right Antibiotic ClassPseudomonas aeruginosa , and Acinetobacter baumannii  have also been linked to increased use of antimicrobials in a single institution [An excessively homogeneous usage (a few compounds/antibiotic classes) may enhance selection pressure and encourage antimicrobial resistance spread ,50. In atitution -58.Over time, MRSA bacteria have become resistant to all β-lactam antibiotics, macrolides, and aminoglycosides. Enterococci have evolved resistance to vancomycin and ampicillin over time. The usage of cephalosporins has been linked to hospital-acquired infections caused by enterococci . In addihttps://aware.essentialmeds.org/).Antibiotics should be administered only when necessary, and the medicine chosen should be the most narrow-spectrum agent that will be successful. Appropriate usage entails selecting the right antibiotic and the correct dose and duration, all of which might impact the development and carriage of resistance microbes . AntibioChoosing the Right DosageAntibiotic resistance is a public health concern, and the fast rise of resistant bacteria has raised public awareness of the issue. Despite this, antibiotic solid usage laws are missing, and the research of new antibiotics is becoming increasingly costly and complicated. Furthermore, antibiotic resistance can be chosen during antibiotic therapy, as it is widely known that selection takes place both at the site of infection and in the commensal flora -64. A neStreptococcus pneumoniae (PRSP) increases [It is logical to expect, and it has previously been demonstrated in vitro, that greater antibiotic dosages are linked with a lower incidence of resistance development than low doses. This linkage is because increased dosages result in higher drug concentrations at infection sites, such as abscesses, empyemas, and other diseases with many bacteria. As a result, higher dosages are likely to result in less de novo resistance ,58,66-68ncreases .Antibiotic resistance develops in the patient due to delays in starting medication, low dosages, and extended intervals between doses (inadequate pharmacokinetics). Notably, very low antibiotic doses can be selected for low-level resistant mutants, acting as stepping stones to high-level resistance ,71. UndeThe usage of antibiotics and the rise of resistance are unquestionably connected. However, with proper antibiotic regimens, the establishment of resistance can be prevented or at least slowed to some extent. Because bacteria's usual reaction to antibiotic exposure is to generate genetic diversity to withstand the antibiotic's effects and because man's normal flora contains species resistant to every antibiotic, antibiotic usage will always result in the formation of antibiotic resistance. All one can hope for is reducing the harm caused by antibiotic use. We know that we can minimize antibiotic prescription in many illnesses that are now being treated needlessly without jeopardizing the health of our patients. Antimicrobial regimens should be tailored to provide therapeutic effectiveness while simultaneously minimizing the formation and spread of resistance. Careful clinical reasoning is the foundation for making the best antibiotic therapy decisions. We can optimize antibiotic treatment by prescribing the right antibiotic, right dose, application, and correct therapy duration.