The paper presents the results of laboratory tests and the complete results of the implementation of the Sprint fast-setting concrete technology used during the reinstallation of the concrete pavement of the DK50 road (the Młodzieszyn bypass). The problem of concrete pavement repair is related to economic and social costs and, above all, to long repair time. After an extensive analysis of various technologies, the authors created a dedicated solution, which, based on commonly existing materials, allows for a very quick repair of the existing pavement. The obtained properties of the fast-setting concrete allow the maintenance of rheological parameters for 2 h from its production and to install the mixture of the consistency of class S3/S4, while the obtained compressive strength exceeds 25 MPa within 6 h of installation. The concrete parameters obtained after 24 h show a strength exceeding 40 MPa, and after 28 days—exceeding 60 MPa. The tensile strength at shattering exceeds 5 MPa, while the tensile strength at flexural strength exceeds 7 MPa. In addition, all parameters of the fast-setting concrete meet the highest requirements currently set for newly built concrete pavement loaded by very heavy traffic. The most important parameter is the possibility to shorten the repair time of concrete pavement to one day, significantly reducing the social costs associated with closing a single lane or the entire road. An important element of the presented technology is the possibility of producing the mixture at a stationary concrete batching plant, and in the future—with the use of bags for patching potholes in road pavement. In the last 10 years, in Poland, we have observed a rapid increase in the number of roads built in cement concrete technology, resulting from the fact that the main routes of motorways and expressways have been completed. The rapidly expanding road network requires preparation for possible repairs of the surface, which must be made under traffic within a certain operational time, minimizing difficulties for road users ,3,4,5. TOn the analyzed section of 2.4 km of the national road No. 50 of the Młodzieszyn bypass, work was carried out by a consortium of OAT and SAT companies in the period April–September 2019, under constant traffic in the field of repairing the concrete pavement by replacing slabs, levelling them, sealing expansion joints, roughening, and utilizing roadside reinforcements.The selection of the type of materials for the design of Sprint 8 quick-setting concrete was based on the requirements of the technical specification . CEM I 53] was used. The design of the concrete mix began with determining the proportions between the aggregate of fractions 2/8 and 8/16 and sand in order to obtain the maximum saturation of the aggregate and the minimum free space between the grains. In the process of designing the mineral mix, granite aggregate of 2/8 and 8/16 mm fractions with a density of 2.65, and 0/2 mm sand with a density of 2.64 [g/cmIn order to eliminate the possible risk of alkali–silica reaction (ASR), tests were carried out to determine the reactivity of the aggregate. The category of alkaline reactivity of the aggregates was determined on the basis of elongation measurements of mortar and concrete samples (direct methods), performed according to the PB/2/18 (long-term 365 days) or PB/1/18 (short-term 14 days) test procedures, respectively. Accelerated elongation testing of mortar samples according to PB/1/18 is carried out separately for fine aggregate 0/2 mm and coarse aggregate of fraction 2/8 and 8/16 mm. The R0 reactivity category is assigned to the aggregate if the elongation of the samples after 14 days of immersion of the mortar bars in a 1 M NaOH solution at 80 °C is not greater than 0.10% (coarse aggregate) or 0.15% (fine aggregate) [The symbols R0 and R1 denote the degree of reactivity of the aggregate: R0 not reactive and R1 potentially reactive. The following symbols are used in The test results obtained in the field of fine aggregate 0/2 mm and granite aggregate 2/8 and 8/16 mm meet the requirements of the test procedures and the aggregates have been classified as R0, i.e., non-reactive.The next step was the appropriate selection of cement to ensure high early compressive strength. The key stage was the selection of chemical admixtures that ensured maintaining the liquid consistency for 2 h and obtaining a minimum of 20 MPa after 8 h.The detailed composition of the designed recipes is presented in As part of the experimental research carried out in the central laboratory in Warsaw, over 300 samples were prepared and tested in order to determine the required properties. As part of the quality control of the delivered quick-setting concrete for the implementation of the investment of the General Directorate for National Roads and Motorways  for the Compressive strength tests were performed according to PN-EN 12390-3  after 8 The compressive strength was determined in accordance with the PN-EN 12390-3 standard after 8 and 24 h and after 28 days of concrete curing. As part of the compressive strength assessment, more than 150 samples were tested in accordance with the requirements of the EN 12390-2 standard. The test results are shown in When analyzing the results of the quick-setting concrete compressive strength test, it should be noted that the most important requirement, i.e., a minimum of 20 MPa after 8 h, was met because the average result was 27.48 ± 3.6 MPa. The results of the compressive strength after 24 h are 42.77 ± 2.5 MPa, which, in the authors’ opinion, allows the road pavement to be approved for traffic. The compressive strength was also assessed after 28 days in accordance with the requirements of the GDDKiA technical specification [Flexural strength was determined in accordance with PN-EN 12390-5 after 28 days of curing. A total of 12 samples were prepared for the test, in accordance with the requirements of the EN 12390-2 standard. The tensile strength was determined in accordance with PN-EN 12390-6 for 15 samples in accordance with the requirements of EN 12390-2. The test results are presented in The flexural strength results obtained for the Sprint 8 quick-setting concrete met the requirements for concrete pavements for roads with very heavy traffic KR7, as they reached a minimum of 5.5 MPa for tensile strength and exceeded 3.7 MPa in the tensile strength test. Analyzing the obtained results, we can see that the average flexural strength obtained was 7.9 ± 0.7 MPa and the average tensile strength was 5.1 ± 0.2 MPa.Concrete frost resistance was tested in accordance with PN-B-06250:1988  using thWhen analyzing the results of compressive strength tests obtained in the frost resistance test, it should be noted that the decrease in compressive strength after 150 cycles of freezing and thawing is only 2.3%. The tested samples of high-speed concrete built into the road surface met the condition required in the technical specification, because the decrease in compressive strength was less than 20% and the weight loss of the samples was less than 5%.Resistance to freezing and thawing in the presence of de-icing salts was carried out in accordance with the procedure described in EN 12.390 PKN-CEN/TS 12390-9 . Sealed 2 and the average weight loss determined after 28 and 56 test cycles was less than 1.0 kg/m2. The ratio of weight loss after 56 days to weight loss after 28 days was less than the required result 2. The freeze–thaw resistance values obtained in the presence of de-icing salts meet the requirements of the FT2 category for freeze–thaw specified in EN 13877-2:2013-08 [During the evaluation, it should be noted that for each of the samples, the weight loss of a single sample was less than 1.5 kg/m:2013-08 .In order to perform a technical and economic analysis of the comparison of concrete pavement repair technologies, two technologies  were compared. The performed analysis consists of calculations of both road management costs related to the renovation and social costs of users and environmental costs.-2;The area of occupation of the surface for the replacement of a single slab, taking into account the space needed for technological service, including machine settings—4.5 m × 30 m = 135 m-Occupation of the roadway to a width of 3.5 m, traffic lane + 0.5 m, marking = 4.0 mThe basis for calculating the costs of the road administrator related to the renovation of the concrete pavement were the analyzed costs of concrete production, costs of technological facilities and labor, costs of concrete curing in the analyzed period, costs of occupying the right-of-way and costs of temporary traffic organization for the purposes of the works. In order to compare the costs of replacing slabs in the analyzed technologies, i.e., from traditional concrete pavement and quick-setting concrete, the following rates were adopted:2/day. For the purposes of further analysis we assume, therefore, 135 m2 × pln 10/m2—pln 1350/day;-Costs of maintenance of the implemented temporary traffic organization—pln 500/day;-Cost of technological facilities and labor—pln 4000/day;-Costs of concrete care—pln 500/day;-3;Costs of traditional surface concrete—pln 500/m-3.Fast-setting concrete delivered from an external manufacturer—pln 3000/m4.0 m/8.0 m = 56%—the rate for occupying the right-of-way when the roadway is occupied more than 50%—pln 10 m3 of C35/45 cement concrete is needed to replace one slab.Calculations of the costs of replacing one slab of concrete pavement were made assuming that the slab has dimensions of 4.0 m × 6.0 m and a thickness of 0.25 m; i.e., 6.0 mA summary of the road manager’s costs of replacing one slab of concrete pavement is presented in When analyzing the costs of replacing one concrete slab, it should be noted that when comparing only the purchase cost of concrete, we obtain a much higher price for quick-setting concrete. However, if we analyze all the costs, such as road lane occupation, technical service costs of temporary traffic organization, maintenance costs, we can clearly see that the total cost of renovation using a traditional concrete mix is pln 75,500 and is four times higher than the comparable quick-setting concrete mix. However, the social costs of users and environmental costs must be considered in order to fully evaluate the cost comparison of high speed concrete technologies.-Cost of operating vehicles based on technical data: type of vehicle , topography , road function , technical condition of the surface according to SOSN , and travel speed of the motor vehicle;-Cost of time for road infrastructure users in passenger transport and goods;-The cost of road accidents and casualties;-The cost of emission of toxic exhaust components.A very important, but often neglected, element of the analysis of the life cycle costs of concrete pavements are the costs of road users and the costs of the natural environment. For this purpose, the Manual for the Assessment of Economic Efficiency of Road and Bridge Projects of the Road and Bridge Research Institute in Warsaw was used. The economic cost categories of refurbishment are calculated on the basis of four main cost categories:○Vehicle operating costs:In order to determine the costs of users and the environment, in accordance with the results of the GPR 2020/2021, data on the average daily annual traffic (SDRR) was determined at the measurement point No. 10906 DK50 on the section from km 66 + 010 to km 78 + 725. On this basis, the SDR for heavy vehicles and the SDR for passenger vehicles were determined. Detailed calculations as well as coefficients and their values used for further calculations were used in accordance with the instructions for assessing the economic effectiveness of road and bridge projects, IBDiM, and economic conditions for the operation of passenger regional transport in Poland according to the following formulas:-e = pln 96,525;Renovation in the traditional concrete technology, K-e = pln 3217.Renovation in the technology of fast-setting concrete, KAccording to the Formula (1), the difference between the cost of operation at a speed of V = 90 km/h and the cost of operation at a speed limited to V = 40 km/h was calculated. The obtained result is the real cost incurred by users, related to the operation of vehicles during repair works:○Time costs of road infrastructure users in passenger transport:In the course of carrying out works in the traditional concrete technology for a period of 30 days, the costs of operating vehicles in connection with the speed limit from 90 km/h to 40 km/h incurred by traffic users amount to pln 96,525; in the case of using high-speed concrete, they amount to only pln 3217 and constitute only 3.3% of the costs incurred by drivers in the traditional surface concrete technology.-c = pln 11,266;Renovation in traditional concrete technology, K-c = pln 376.Renovation in the technology of fast-setting concrete, KAccording to the Formula (2), the difference in cost between the standard cost at a speed of V = 90 km/h and the cost at a speed limited to V = 40 km/h was calculated; the result is the difference, which is the real cost incurred by users related to the time of road infrastructure users in passenger transport:○Costs of road accidents and victims of road infrastructure users:The time costs of road infrastructure users in passenger and freight transport due to the speed limit from 90 km/h to 40 km/h incurred by traffic users amount to pln 11,266; in the case of using high-speed concrete, they amount to only pln 376 and account for only 3.3% of the costs incurred by drivers in the traditional surface concrete technology.-w = pln 174,135;Renovation in the traditional concrete technology, K-w = pln 5804.Renovation in the technology of fast-setting concrete, KAnalyzing the risk of road accidents on the section covered by the study, i.e., 1 km, taking into account the average costs of a road accident and accident victims, we obtain costs estimated on the basis of the risk of an event occurring during the works in individual technologies, taking into account the time of their implementation:○Environmental pollution costs of road infrastructure users:The risk of an accident in the long term of the works is significantly higher than in the case of one-day works, the risk of costs incurred in the case of traditional surface concrete is estimated at pln 174,155, and in the case of high-speed concrete technology only pln 5804, which proves a significant reduction in the risk of an accident and minimizes social costs.-s = pln 36,985;Renovation in traditional concrete technology, K-s = pln 1233.Renovation in the technology of fast-setting concrete, KSubstituting the individual coefficients into the Formula (4), and in particular the unit costs of environmental pollution in relation to the type of vehicle and the type of terrain on which the given vehicle is moving, we obtain the costs of environmental pollution of road infrastructure users:2 emissions, and road noise. The greatest nuisance for the environment is generated by traffic restrictions related to the execution of works, in the traditional surface concrete technology they amount to pln 36,985, and in the quick-setting concrete technology, only pln 1233, which is 3.3% of the costs compared to the traditional concrete technology. The costs of users and the environment are hidden costs, very often they are not directly analyzed and generated for the investor and, thus, are most often omitted in the process of determining the cost of renovation. In order to show the actual costs incurred by the road user and the environment, a tabular summary was made, taking into account the conditions prevailing at the time before the renovation, i.e., for the travel speed of V = 90 km/h and with the traffic limited to the speed of V = 40 km/h. Such a comparison of the costs and possible benefits of reducing the repair time from 30 to 1 day is presented in The costs of environmental pollution mainly consist of air pollution with nitrogen oxides NO, carbon dioxide COIn the case of the traditional surface concrete technology, the costs of users and the environment are pln 318,911; in the case of the use of high-speed concrete technology, the costs are only pln 10,630. Analyzing the obtained results, it can be concluded that the greatest impact on such a large difference is the costs of road accidents, which account for 55% of the costs, and the costs of vehicle operation, which account for 30% of the costs of users and the environment.However, the most important conclusion from the analysis is the possibility of generating savings for users and the environment through the use of quick-setting concrete, amounting to pln 308,281.The aim of the research project was to design and implement a quick-setting concrete that meets the requirements of the contracting authority, i.e., to achieve a minimum of 20 MPa after 8 h and workability up to 2 h. During the renovation of the Młodzieszyn bypass, an average of 24.5 MPa was achieved after 8 h and over 42.8 MPa after 24 h of construction. In addition, the concrete mix maintained the consistency of S4 after 2 h of transport to the construction site, which greatly facilitated the placement of concrete. Analyzing the obtained concrete compressive parameters, a thesis can be put forward that after one day such a surface can be loaded with heavy traffic because the obtained compressive strength exceeded 42.8 MPa. The results of testing such features as flexural tensile strength and splitting significantly exceeded the requirements and amounted to 7.9 MPa and 5.1 MPa, respectively. In accordance with the requirements for surface concretes, frost resistance was determined after 150 cycles of alternating freezing and thawing to obtain a decrease in compressive strength of 2.3% and a loss of mass of 0.29%. It is worth noting that none of the tested samples showed cracks or damage after the frost resistance test. Such results testify to the very high quality and durability of the discussed concrete. In addition, the experimentally determined resistance to freezing and thawing in the presence of salt (NaCl) proves its resistance to combined exposure to frost and de-icing salt. The fast-setting concrete offered by Lafarge met all the requirements contained in the technical specification and can be successfully used as an alternative solution for the repair or partial replacement of concrete pavement for very heavy traffic. The most important advantage of this solution is shortening the repair time to 24 h and reducing the nuisance for users by lowering economic and social costs. When analyzing the costs of renovation in traditional technology and quick-setting concrete, the full costs of the road infrastructure manager should be taken into account. These costs should include not only the costs of the concrete mix but also the costs of occupying the right-of-way, maintenance costs, costs of technological facilities, and maintenance. After making full calculations, it turns out that the use of fast-setting concrete is economically justified. A very important element of the analysis is the possibility of generating additional economic benefits for road users and the natural environment, which in the analyzed case amount to over pln 308,000.(1)The compressive strength was 27.5 MPa after 8 h and more than 42.8 MPa after 24 h, which means that this concrete meets the highest requirements for repair concretes.(2)Values of frost resistance after 150 cycles of alternating freezing and thawing as well as determination of resistance to de-icing agents testify to very high quality and durability of concrete.(3)The concrete mix tested during delivery and after 2 h of transport was characterized by high workability and the marked consistency was at the level of S3/S4.(4)An example of the practical use of concrete during the renovation of the Młodzieszyn bypass allows to shorten the time of repair or replacement of the concrete surface to one day, minimizing economic and social costs for road users and the road administrator.(5)In further research plans, the authors plan further research on the possibility of shortening the time of repair or replacement of the concrete pavement through the use of new polymer admixtures and additives for concrete.Based on the research and analysis of high-speed concrete carried out by the authors, the following conclusions can be drawn:Future directions and limitations—The presented solution, apart from tests in the laboratory, was industrially implemented on the national road No. 50 during the renovation of the concrete pavement. Renovation of the road with a concrete surface was carried out for the General Directorate for National Roads and Motorways. The obtained test results of the built-in fast-setting concrete were positively assessed in terms of quality and test results obtained. Further modifications of the concrete composition are planned in the near future, aimed at obtaining early compressive strength after 6 h, and not after 8 h as before.


The total days of antibiotic usage during the entire NICU stay also showed a significant reduction . After adjusting for confounders, the reduction in antibiotic usage was associated with decreased odds of having an adverse composite short-term outcome . To assess the continuity of antibiotic stewardship in the NICU, data from 2021 were also analyzed and compared to 2016. The median duration of an initial antibiotic course further decreased from 5.0 days in 2016 to 4.0 days in 2021 (p < 0.001). The proportion of an initial antibiotic course in which antibiotics were used for ≤3 days increased . Total antibiotic usage days during the entire NICU stay also decreased from 10.0 days in 2016 to 7.0 days in 2021 (p = 0.010). The finding of this study strongly suggests that restricting antibiotic use in VLBW infants is beneficial and can be achieved safely and effectively in China.Antibiotics are essential for treating neonatal sepsis, but abuse or inappropriate use of antibiotics have harmful adverse effects. The inappropriate use of antibiotics has led to the significant increase in bacterial antimicrobial resistance in the neonatal intensive care unit (NICU). The aim of this study was to retrospectively analyze the changes in antibiotic usages in a NICU after the implementation of an antibiotic stewardship program and to determine the impact of this implementation on the short-term clinical outcomes of very low birth weight (VLBW) infants. The antibiotic stewardship program was initiated in the NICU in early 2015. For analysis, all eligible VLBW infants born from 1 January 2014 to 31 December 2016 were enrolled, and we classified the year 2014 as pre-stewardship, 2015 as during stewardship, and 2016 as post-stewardship. A total of 249 VLBW infants, including 96 cases in the 2014 group, 77 cases in the 2015 group, and 76 cases in the 2016 group, were included for final analysis. Empirical antibiotics were used in over 90% of VLBW infants in all three groups during their NICU stay. Over the 3-year period, the duration of an initial antibiotic course was significantly reduced. The proportion of patients receiving an initial antibiotic course for ≤3 days gradually increased (2.1% vs. 9.1% vs. 38.2%,  Neonatal sepsis remains one of the leading causes for neonatal mortality and morbidity. Antibiotics are essential for treating neonatal sepsis, but abuse or inappropriate use of antibiotics have harmful adverse effects. A number of studies have suggested that the unnecessary early use of antibiotics increases the incidence in premature infants of clinically adverse outcomes such as late-onset sepsis (LOS), necrotizing enterocolitis (NEC), and severe intraventricular hemorrhage (IVH) ,2. OtherEscherichia spp. and Klebsiella, were resistant to the widely used third-generation cephalosporins. The increase in MDR bacterial infections in newborns due to antibiotic abuse has made treatment more difficult and economically burdensome for developing countries [More importantly, the inappropriate use of antibiotics has led to a significant increase in bacterial antimicrobial resistance and the spread of bacterial antibiotic-resistant genes. As a result, neonatal multidrug-resistant (MDR) bacterial infections are now a global challenge . By mergountries . This haountries .Wang MJ et al. recently reported survey data about the abuse of antibiotics in 24 neonatal intensive care units (NICU) in Hunan Province, China. They found that in very low birth weight (VLBW) infants (newborns with birth weight less than 1500 g), on average, antibiotics were administered for more than half of the duration of their hospital stay . RecogniA total of 351 VLBW infants were admitted during the study period. The flow diagram of enrollment is presented in p > 0.05). The proportion of Apgar scores ≤ 7 at 5 min was higher in the 2016 group than in the 2014 group  , in vitro fertilization (IVF), premature rapture of membrane (PROM), cesarean delivery, invasive mechanical ventilation for the first 3 days after birth, and antepartum antibiotics usage were not statistically significant  .p < 0.001). The proportion of the initial antibiotic courses in which antibiotics were used for ≤3 days gradually increased , while the proportion of initial antibiotic courses >7 days significantly decreased . Total antibiotic usage days during the entire NICU stay also showed a significant reduction, with the median total antibiotic usage days decreasing from 27.0 days in 2014 to 21.0 days in 2015 and then to 10.0 days in 2016 (p < 0.001). The antibiotic use rate (AUR) also declined significantly over the period of the study with the median of 64% in 2014 decreasing to 39% in 2015 and then further to 12% in 2016 (p < 0.001). These findings illustrate that the duration of antibiotic use in this NICU was significantly reduced after the initiation and implementation of the antibiotic stewardship program in 2015 . The difference in the days of hospitalization among the three groups was also not statistically significant (p > 0.05). However, the differences among the three groups were statistically significant in the incidence of severe IVH, with a lower incidence of severe IVH seen in 2016 than that in 2014 . There were significant reductions in the days to full enteral feedings over the 3 years. The median days to full enteral feeding in 2016 was 17.0 days as compared to 21.5 days in 2015, and 26.0 days in 2014 (p < 0.001). These data strongly suggest that reducing the antibiotic usage days over the 3-year period in VLBW infants was not associated with an increased incidence of worse short-term adverse clinical outcomes. If anything, it is associated with improved short-term outcomes in VLBW infants , and severe bronchopulmonary dysplasia (BPD), , and an approximately 18% increase in risk of clinical composite adverse outcomes for every 10% increase in AUR .To further determine the association between antibiotic use and short-term adverse clinical outcomes, the presence of any of the following conditions are defined as composite adverse outcomes: death, NEC, LOS, severe IVH, severe ROP, and severe BPD. Using logistic regression analysis, an association was identified between the composite adverse outcome with both the number of days of early antibiotic use and the AUR. There was an increased risk of clinical composite adverse outcome in the >7 days group when compared to the ≤3 days group (p < 0.01). After adjusting for confounders, the risk of having a composite adverse outcome in infants who received more than 7 days of antibiotics as the initial antibiotic course was 5.1-fold  higher than those received 0–3 days as the initial antibiotic course. Since there was a significant reduction in antibiotic use in 2016, the adjusted OR for composite adverse outcome in 2016 was also significantly reduced (p < 0.001) when using that of 2014 as a baseline reference  (p < 0.001). The median duration of the initial antibiotic course decreased from 5.0 days in 2016 to 4.0 days in 2021 (p < 0.001). The proportion of the initial antibiotic courses in which antibiotics were used for ≤3 days increased , while the proportion of initial antibiotic courses > 7 days significantly decreased . Total antibiotic usage days during the entire NICU stay also decreased from 10.0 days in 2016 to 7.0 days in 2021 (p = 0.010). The AUR also declined significantly over the period of the study with the median of 12% in 2016 decreasing to 7% in 2021 (p < 0.001).VLBW infants in the 2021 group have greater gestational age, higher birth weight, lower proportion of males and surfactant usage, and a higher proportion of cesarean delivery compared to 2016  . Comparep > 0.05). The difference in the days of hospitalization among the two groups was not statistically significant (p > 0.05). However, the median of days to full enteral feedings in the 2021 groups statistically increased when compared to 2016 . The results suggest that the antibiotic use strategy was maintained in 2021, and that antibiotic usage was substantially reduced . Multivariate logistic regression analysis indicates that the risk of composite short-term adverse outcome in VLBW infants increases by approximately 17% for every 10% increase in AUR. After the implementation of an antibiotic stewardship program in 2015 in the NICU, the outcomes of the VLBW infants cared for in the NICU in 2016 were indeed improved. This study illustrates that by implementing an antibiotic stewardship program, the antibiotic abuse in VLBW infants in developing countries such as China can be safely and effectively reduced without increasing the clinical complications, the possibility of which concerned some care providers. The study also demonstrates that the adjustment to the antibiotic stewardship program is sustainable, confirming its safety. In fact, better outcomes may be achieved with more restrictive use of antibiotics in VLBW infants.Premature infants, especially those with VLBW, are at high risk of developing bacterial infections or sepsis . FurtherIt is recommended that empirical antibiotics may be discontinued if the blood culture remains negative after 48 h and the child’s clinical presentation does not indicate ongoing infection . This suA large data set study of 135 hospitals in the United Kingdom from 2010 to 2017 confirmed that antibiotic usage did not correlate with patient morbidity and mortality . Other sAs a retrospective study, it does have inherent limitations. The first limitation is that the main data are more than 6 years old, even though this study employed recent data from 2021 to demonstrate the continued influence of this antibiotic usage strategy. Due to possible practice changes over the last 5 years, we did not include the data from 2021 for logistic regression analysis. Secondly, the reduction in antibiotic abuse may decrease the emergence of MDR bacterial pathogens in the NICU. Unfortunately, the authors do not have data about the effects of antibiotic practice changes in VLBW infants on the prevalence of MDR in this NICU. Another limitation of this study is that as a single-center retrospective cohort study with a time span of >3 years, it is possible that the effect of daily practice changes is not controlled through multivariate regression analysis. A multi-center clinical trial is needed to confirm the effects and the safety of restricting antibiotic use in VLBW infants. Nevertheless, this study is one of the first aimed at improving the antibiotic use strategy for VLBW infants in China, with notable improvements in terms of antibiotic practice. We hope that this study will encourage more related studies, in an effort to improve the prognosis of VLBW infants in China.This is a single-center retrospective cohort study performed in the NICU of Xiangya Hospital of Central South University. The authors initiated an antibiotic stewardship program in early 2015. In order to examine the longitudinal effect of this stewardship program, all eligible VLBW infants from 2014 to 2016 were enrolled into the study and divided the study population into three groups based on their delivery dates: in 2014, 2015, and 2016. For analysis, the year 2014 was classified as pre-stewardship, 2015 as during stewardship, and 2016 as post-stewardship.From 1 January 2014 to 31 December 2016, the VLBW infants admitted to the NICU were enrolled and the following data were collected from the medical records: (1) gestational age, birth weight, sex, and relevant resuscitation in the delivery room; (2) relevant maternal perinatal data; (3) initial NICU respiratory management; (4) duration of antibiotic use ; (5) days to full enteral feeding, and duration of hospitalization; (6) major short-term outcomes including death, late onset sepsis (LOS), necrotizing enterocolitis (NEC), severe intraventricular hemorrhage (IVH), severe bronchopulmonary dysplasia (BPD), and ≥3 stage retinopathy of prematurity (ROP).The exclusion criteria include (1) those admitted after 24 h of birth; (2) those with culture proven early onset sepsis (EOS); (3) those who died within 1 week of life; (4) those with major malformations; (5) those with suspected or confirmed genetic metabolic diseases; (6) those with incomplete medical records. During the three years of the study, there were no major changes in the respiratory support equipment and strategies, NICU physical environment, or staffing conditions. The routine testing of various specimens was performed by the clinical laboratory of Xiangya Hospital of Central South University.To assess the continuity and impacts of antibiotic stewardship interventions, data from 2021 were also employed and compared to 2016. The same inclusion and exclusion standards were applied, and similar data were collected. In 2021, a total of 105 VLBW infants were recruited, and after excluding 12 cases hospitalized after 24 h of birth and 3 cases with suspected or confirmed genetic metabolic disorders, 90 VLBW infants were eventually enrolled.The study was approved by the Ethics Committee of Xiangya Hospital of Central South University and conducted in full compliance with medical ethics standards. Clinical data were collected retrospectively from the hospital medical records. A waiver for parental informed consent had been granted from the Institutional Ethics Committee .The definition of sepsis was based on the most recent criteria outlined by the China National Committee , and hast-test was used for normally distributed variables between two groups. The Kruskal-–Wallis H test was used for non-normally distributed variables, and comparisons between groups used the mean rank’s post hoc multiple comparison of Kruskal–Wallis H test. The categorical data were expressed as rates (%) and the Chi-square test or Fisher’s exact probability method, and the Chi-square splitting method were used for comparisons between groups. For comparisons across groups, the test level was modified to a statistically significant difference of p < 0.0167. Univariable and multivariable logistic regressions were used to evaluate the associations between antibiotic use and the composite clinical short-term adverse outcome  as the dependent variable, and grouping variables, early antibiotic course distribution and AUR as independent variables, correcting for confounding factors such as gestational age, birth weight, Apgar scores, etc. Two-sided p < 0.05 was considered as representing statistical significance.Statistical analysis was performed using SPSS 22.0 statistical software . Normally distributed data were expressed as mean and standard (With the introduction of an antibiotic stewardship program which includes formulating specific guidelines and provider education for the diagnosis and treatment of sepsis in VLBW infants, the duration of empirical antibiotic use in VLBW infants was significantly reduced. The reduction in antibiotic usage was associated with a decreased odds of having an adverse composite short-term outcome, suggesting that restricting antibiotic use in VLBW infants is beneficial and can be achieved safely and effectively in China. The study also demonstrates that the antibiotic stewardship program in a NICU is sustainable.


Then, the Scipy library combined with GA-ANN is used for the multi-objective optimization of concrete mix proportions to balance the compressive strength and costs of concrete. Moreover, an AI-based concrete mix proportion design system is developed, utilizing a user-friendly GUI to meet specific strength requirements and adapt to practical needs. This system enhances optimization design capabilities and sets the stage for future advancements. Overall, this study focuses on optimizing concrete mixture design using hybrid intelligent modeling and multi-objective optimization, which contributes to providing a novel and practical solution for improving the efficiency and accuracy of concrete mixture design in the construction industry.Concrete mixture design has been a key focus in concrete research. This study presents a new method for concrete mixture design by combining artificial neural networks (ANN), genetic algorithms (GA), and Scipy libraries for hybrid intelligent modeling. This method enables the prediction of concrete mechanical properties and the optimization of mix proportions with single or multi-objective goals. The GA is used to optimize the structure and weight parameters of ANN to improve prediction accuracy and generalization ability (R Concrete is a typical construction material generally composed of cement, sand, aggregates, and water. Characterized by strong plasticity and easy construction, concrete has been the most widely used material in various constructions, such as encompassing residential buildings, bridges, tunnels, and roads ,2. The sThe conventional approach for concrete mixture design relies on a trial-and-error methodology, which is not only time consuming but also cost intensive ,5. Parti2 = 0.92) indicates that machine learning models can accurately estimate the compressive strength of SCC. In addition, Xue et al. [In recent years, artificial intelligence (AI) has experienced rapid development, which has enabled efficient processing and analysis of large datasets while also simulating human thinking and behavior . Machinee et al.  proposedAlthough ANNs have many advantages, they still possess certain limitations. If the amount of data is insufficient, it may cause the network to overfit or underfit, thus affecting the prediction accuracy . DespiteBased on these considerations, this study proposes the utilization of machine learning (ML) techniques for performance prediction and multi-objective optimization of concrete materials. Specifically, a reliable dataset is collected from real engineering projects, and the correlation between data features and independent variables is analyzed. Subsequently, a GA-ANN model is established to predict the compressive strength of concrete, and the accuracy of this model is thoroughly evaluated. Finally, a multi-objective search algorithm (Scipy library) is employed to achieve the optimization of the concrete mixture within the desired strength range and under cost constraints.In conclusion, this study combines ANN and GA to optimize the structure and weight parameters of the ANN model, which improves prediction accuracy and generalization. Scipy library is utilized for multi-objective optimization of concrete mixtures, contributing to making trade-offs between different goals and obtaining concrete mixtures that meet both strength requirements and cost considerations. Last but not least, based on a hybrid intelligent modeling approach, a GUI software V1.0 is developed, which not only predicts the compressive strength of concrete but also provides guidance for engineers and researchers in the concrete mixture design process. By incorporating AI technology, the software enhances the efficiency and accuracy of concrete mixture design, allowing for the optimization of various performance characteristics.The dataset used in this study comes from the CCCC Second Harbor Engineering Company LTD and contains 500 data. Eight input variables are considered in the data set, cemented materials including cement (OPC), fly ash (F), and admixtures (AD), fine aggregate (F-A), coarse aggregate (C-A), in addition to water (W) and superplasticizer (SP). The compressive strength and cost of the concrete prepared are obtained experimentally, with results that are taken as the output value.Moreover, During the sample mixture compaction and curing method, a standard procedure was followed. The curing temperature was maintained at 20 ± 2 °C, and the relative humidity was kept at no less than 95%. The strength was tested using a 150 × 150 × 150 mm test block and in accordance with the standard (GB/T 50081-2019) [In this dataset, Artificial neural networks (ANNs) are a typical ML model inspired by the structure and function of the human brain . ANNs co2) [The mathematical operations performed via ANNs are based on linear algebra, matrix multiplication, and calculus . In the 2) . These mThe ANN is composed of multiple neuronal models connected according to certain rules. The commonly used neuronal model is the fully connected neuron named ‘M-P neuron model’. The multi-layer perceptron structure and general formula for MP neurons in an ANN can be expressed in Equation (1) .(1)yj=fReLU function is a popular activation function in ML models . CompareThe sigmoid function is defined as Equation (2):The hyperbolic tangent function is defined as Equation (3):The ReLU function is defined as Equation (4):In ANN models, the weights between neurons are commonly initialized randomly. The ANN is then trained using an optimization algorithm, such as gradient descent or backpropagation, with the aim of minimizing a cost function. This cost function quantifies the difference between the predicted outputs generated by the ANN and the actual outputs observed in the training data. The optimization algorithm iteratively adjusts the weights in order to improve the accuracy of the predictions and reduce the cost function to its minimum value ,27. The 2) [The test dataset is used to verify the predictive ability of the optimized artificial neural network model. To make a more comprehensive and better comparison, some statistical error analysis parameters are used as criteria for evaluating the model . Importa2) . These p2) :(5)MSE=1Step 1: Collect the dataset and perform data mining.GA originated from computer simulation studies conducted on biological systems is a stochastic global search optimization method . It simux1), FA (x2), MP (x3), Admixture (x4), F-A (x5), C-A (x6), Water (x7), and SP (x8), while the output vector is compressive strength (T1) and a correlation equation between input and output vectors is established. To show the relationship between input and output vectors, a heatmap can be used. By combining knowledge from materials science, it is possible to explain the reasons for the influence on concrete performance.The dataset includes input vectors and output vectors. The input vectors in this article are OPC  belong to this type , shown iThen, determine the parameters of individual neurons, weights, and biases. According to Equation (1), the output signals of each neuron can be calculated , as seenix), hidden layer, and output layer (y), as specifically illustrated in Finally, determine the multi-layer perceptron (MLP), including the input layer  Establish the fitness function. One characteristic of GA is its ability to obtain search information using only the objective function of the problem at hand. The objective function is reflected in the evaluation of individual fitness for minimization problems , which i(b) Individual selection. GA uses selection decisions to choose superior individuals and eliminate inferior ones. High-fitness individuals are then passed on to the next generation. The proportionate fitness scaling method is a classic selection decision method that calculates an individual’s selection probability based on its fitness value , shown i(c) Genetic crossover. Crossover is the process of replacing and recombining parts of genes from two parent individuals to generate a new individual. When designing the crossover operator, one must consider the individual encoding design. Simulated binary crossover (SBX) is a frequently used crossover operator in continuous optimization methods, and the selected gene changes followed Equations (13) and (14) .(13)yi1(d) Genetic mutation. Introducing mutations not only improves the local search ability of the GA but also maintains diversity among individuals in the population. The simplest mutation method is uniform mutation, which replaces the original gene value of each gene in the individual with a uniformly distributed random number within a certain range , with a Step 4: Optimize ANN with GA shown in .Machine learning models are trained and evaluated. Training an ML model is an iterative process that requires constantly adjusting the parameters of model to improve its accuracy and efficiency. Evaluating an ML model involves measuring its performance with a test dataset. If the performance of the model is not satisfactory, it is necessary to go back to previous steps with adjustments until the desired results are achieved.Optimization algorithms systematically explore potential solutions to approximate the optimal solution, making them invaluable in various domains, such as engineering, computer science, physics, and economics ,29. TheiScipy provides a variety of optimization algorithms that can be used to solve different types of optimization problems. Based on Scipy, the optimization algorithms are used to find the optimal solution for a given problem. The problem can be either to maximize or minimize an objective function. Furthermore, ‘scipy.optimize.minimize’ is a function available in the ‘scipy’ library that offers a unified interface for minimizing different optimization algorithms, such as nonlinear least squares, nonlinear programming, and root finding, which are defined as Equations (16)–(20) . It is cIn nonlinear least squares, where the non-linear model is In nonlinear programming, where Root finding is the process of finding the zero of a function by approximating the zero point repeatedly. For instance, the Newton method uses the Taylor series expansion to estimate the value of the function The Scipy library includes a function called Scipy.optimize, which uses an iterative-based optimization algorithm to find the minimum or maximum value of an objective function. The algorithm works by determining the gradient and Hessian matrix of the objective function in the direction of the step matrix of the variable vector in the next step. The gradient and Hessian matrices represent the first and second derivatives of the objective function at a specific point ,32.For evaluating the influence of various components of raw materials on the mechanical properties of concrete, the third part conducts a correlation analysis on the complex relationships between various raw material parameter variables based on statistical analysis methods. Then, a GA-ANN model is established to predict the compressive strength of concrete and compared with the ANN model. Finally, combined with the Scipy algorithm, a multi-objective optimization design is conducted to obtain a mix ratio that meets both the high strength and low economic cost of concrete. At the same time, an expert evaluation system is established to assist in concrete design.The construction of the ANN model relies on datasets comprising input and output labels . In thisThe preprocessing of the dataset generally consists of two parts: one is the reasonable division of the dataset, and the other is the normalization or standardization of the dataset. The dataset is divided mainly to complete the training and testing of the model, and the common allocation rates for training, validation, and testing are 60%, 20%, and 20%, as shown in GA can optimize the structure and weight parameters of ANN, improving their prediction accuracy and generalization ability ,22. GA iWhen optimizing ANN, selecting the right network parameters is crucial. These parameters can have a significant impact on the performance of the network and prediction accuracy. This study employed a feedback-type topology structure consisting of eight input vectors and one output vector for the prediction of compressive strength. The established ANN has four hidden layers, each containing 50 neurons, with an epoch of 200 times, a learning rate of 0.001, a training batch size of 2, a testing batch size of 40, and a ReLU activation function, which has been one of the latest and most commonly used functions ,35. CommIn addition to selecting neural network parameters, it is crucial to dynamically adjust model parameters during the training process to improve the performance and prediction accuracy of ANNs. After applying a GA optimization algorithm to optimize the parameters of the ANN, a population size of 8, parent mating at 4, 2000 generations, and a 5% mutation rate were chosen. To ensure that the GA converges to an optimal ANN structure and weight parameters, several techniques can be employed, including the selection process, crossover operation, mutation operation, fitness evaluation, and generation count. Random changes are introduced in the genetic material of individuals through mutation operations, which helps prevent premature convergence to suboptimal solutions. The genetically optimized ANN demonstrated a decreasing curve relationship between the loss function and the iteration number, indicating improved performance. This implies that as the number of iterations increases, the network loss gradually decreases, and the network fitting effect improves. 2 greater than 0.95, and RMSE and MAE both less than 10, indicating a high fitting accuracy to the dataset. The conclusion shows that GA-ANN is suitable for predicting the strength performance of concrete with good accuracy.Finally, it is necessary to evaluate the model to continuously optimize the algorithm and improve its accuracy and performance in practice. 2 = 0.95) and the value of ANN (R2 = 0.80), indicating high accuracy in predicting concrete strength. These results suggest that the ANN model optimized by GA has better prediction accuracy than the ANN model alone, and the correlation coefficient R2 increases by about 15%. This finding demonstrates that GA can optimize the structure and parameters of neural network models and improve their prediction performance. GA searched for a better network structure by increasing, decreasing, or changing the connection mode between the layers and obtained the number of hidden layers in the neural network and the number of neurons. Moreover, GA can optimize the parameters of the neural network, but the resulting optimization result is usually a parameter combination rather than the visual graph structure, so it is difficult to show the details clearly. In summary, GA can improve prediction performance, providing an effective method for the practical application of concrete performance prediction.The GA-ANN model was trained and evaluated by dividing the dataset into training, validation, and testing datasets. The error analysis shows that the GA-ANN model has excellent learning and fitting performance. To further verify the optimization effect of GA on the network structure, an ANN model with the same number of hidden layers and neurons was built to compare with GA-ANN. The prediction value is shown in The purpose of multi-objective optimization is to find a set of solutions that optimize multiple interdependent objectives, ensuring that all objective functions are optimal or close to optimal ,38. HoweTo balance the need for improved concrete strength and lower cost, the Scipy library will be utilized for multi-objective optimization of concrete mixtures. First, two conflicting functions should be established, i.e., the target function of compressive strength and the content of each component raw material, which could be represented using the GA-ANN prediction model. By inputting the parameters of each experimental variable of the concrete into the established GA-ANN model, the compressive strength values with high accuracy were obtained. The target function for maximum compressive strength is briefly expressed in Equation (23). After collecting the information on raw materials, the relationship formula between the cost of eight experimental variables and the total price of concrete is established (as shown in Equation (25)), and the raw material prices are listed in B1, and the lower boundary is B2. After establishing two conflicting equations that require optimization, the range for eight variables was determined based on the basic range of concrete mix proportions. Boundary condition indicates whether the decision variables have a boundary (1) or not (0). The upper boundary is In recent years, the rapid development of AI technology has greatly accelerated the process of intelligence and information in all walks of life and brought new opportunities and challenges to traditional industries ,40. In tAs the database grows larger and the complexity of ANN increases, computers need to have greater computing power, which is coordinated computing via a personal computer and a cloud computing server. The concrete mixture design system uses a GUI, which can obtain some concrete mixture design schemes, that satisfy the highest compressive strength and the lowest cost. The input module of the system includes cement (OPC), fly ash (FA), mineral powder (MP), other admixtures (AD), fine aggregate (F-A) and coarse aggregate (C-A), superplasticizer (SP), and water (W), and the output module is concrete mixture design schemes. The expert evaluation system provides great assistance and convenience for engineers and researchers because the performance prediction and the design results are based on the modeling of 487 tests in the database. The researcher can verify the test according to the mix ratio provided by the model and then adjust it according to the experience, reducing a lot of manual attempt time. In addition, through the design of GUI, researchers and engineers are also able to enrich the performance of concrete through the GA-ANN model and Scipy library, such as mobility, durability, toughness, etc., to better adapt to actual needs, and will conduct more in-depth research and exploration in the future.(1)Material preparation: select the appropriate raw materials to determine their particle size distribution.(2)Mixing design: determine the appropriate boundary conditions for raw material content, input the preliminary mixture into GA-ANN software (V1.0) for performance prediction, and then determine the design objectives and requirements , and finally run the five sets of preliminary mixing ratios in the program.(3)Expert review: evaluate whether the preliminary mixture meets the objectives and requirements, and score the five groups of mix ratios. If the requirements are not met, repeat steps (2) to adjust until the objectives and requirements are met to obtain the optimized mixture.(4)Sample preparation: the concrete is prepared according to the optimized mixture ratio, and the feasibility of the mixture is further verified.In this study, to realize precise mixture design of concrete, a new software used for hybrid design method combining GA-ANN and Scipy optimization algorithm is proposed. The specific process of this method is described as follows:Furthermore, to demonstrate the feasibility and utility of this hybrid design approach, the following is a schematic diagram of the application of specific hybrid design examples.During the process (2) mixing design, the concrete mix design software operates as shown in Example 1: Single objective—maximum compressive strengthDuring the process (3), it is necessary to rely on specific project requirements to carry out expert evaluation. First, the strength of the five mixed design proportions obtained in the process are tested (2). Then, the price of concrete per cubic meter of sample is calculated based on Equation (25). Expert evaluation is a scoring system based on the target performance requirements. Below are three examples of expert evaluation scoring:The single target design follows the principle of highest intensity. Within the software, after entering the target strength range and running it, the output mix proportion data are displayed in groups, ranked from high to low according to strength. The mixture with the highest strength scores 10 points, and each lower rank reduces by two points, with the mix with the lowest strength scoring 0 points. The first set of data obtained is the mixed proportion data with the highest design strength and can be easily selected as the single target design. For example, in Example 2: Single objective—minimum economic costThe single target design follows the principle of minimum cost. Use the economic cost principle and Equation (22) for price calculation. After ranking the prices from high to low, apply the same scoring criteria as in the intensity principle. Then, select the mix proportion with the lowest price per cubic meter of concrete as the target design mix proportion. For instance, in Example 3: Multi-objectiveThe multi-objective design of fixed-strength range and economic cost. Obtain five sets of concrete mix designs within the target strength range and rank them based on both strength and price in descending order, using the same scoring method as mentioned above. The final score is obtained by adding up the scores. For example, in Consequently, Scipy offers several advantages: versatility, ease of use, and performance, which provide a user-friendly interface and comprehensive documentation, making it relatively easy for researchers and engineers to implement and apply multi-objective optimization. Scipy is known for its efficient and robust implementation of optimization algorithms. It leverages optimized numerical routines and algorithms, resulting in faster convergence and improved computational efficiency. Hybrid models are highly flexible and scalable for various multi-objective solving problems. Using both ANN expression ability and Scipy’s optimization algorithm, multiple objective functions were established, and a set of balanced optimal solutions were found. It provides decisionmakers the ability to make trade-offs between different goals and obtain good solutions, which improves efficiency and accuracy. That is the reason why the hybrid methods can optimize not only a single target of compressive strength but also the design for both cost and strength.This article introduces a novel method for designing concrete mixes, which utilizes ANN, GA, and Scipy library for hybrid intelligent modeling. By predicting the mechanical properties of concrete, this method can also establish objective functions that effectively optimize the single or multi-objective proportion design of specific mixtures.(1)2) compared to ANN. GA-ANN achieves excellent training results , indicating high accuracy in predicting concrete strength.Genetic algorithms (GA) can optimize ANN structure and weight parameters, improving prediction accuracy and generalization. The results show a 19% increase in correlation coefficient (R(2)To balance the need for higher concrete compressive strength and lower cost, the Scipy library was utilized for the multi-objective optimization of concrete mixture. The multi-objective design framework mainly includes two parts: determine the range for ingredients proportions and boundary conditions and establish two conflicting functions, including the target function of strength and the cost of concrete. Through the experimental validation, the accuracy of the model reached 97.3%, and the best proportion reached 46.3 MPa, which met both the compressive strength and the low-cost requirements. It is proved that the obtained target compressive strength is basically consistent with the experimental value,(3)Based on the established ML models, this paper further builds a concrete mixture design graphical user interface (GUI) software (V1.0), which not only can predict the compressive strength of concrete but also provide reliable guidance for researchers and engineers to concrete mixture design.(4)This study introduces an innovative method that integrates artificial intelligence technology into concrete research, allowing for multi-objective design and property prediction. By combining AI with concrete technology, it maximizes the information processing capabilities in the concrete industry. However, further research is needed to enhance the interpretability, accuracy, and generalization of artificial neural networks. This will contribute to future advancements in the field of concrete and the continued development of AI applications.


Rapid point-of-care testing for respiratory pathogens has gained increasing popularity, but its impact on antibiotic consumption is unclear. Thus, the aim of this systematic review and meta-analysis was to estimate the effect of rapid point-of-care testing on antibiotic prescriptions.The search for this systematic review with meta-analysis was performed in February 2023. Randomized controlled trials investigating the impact of testing for respiratory pathogens in all-aged patients were included regardless of the comparator. The main outcome was the antibiotic prescription rate. Analyses were stratified by test type, test setting, and patient age. A random-effects Mantel-Haenszel model was used to calculate risk ratios with 95% confidence intervals. Risk of bias was assessed for included studies, and the quality of the evidence was rated according to GRADE.A total of 754 abstracts were screened, and 10 studies were included in the analysis. Risk of bias was high in 2, low in 4, and had some concerns in 4 studies. Four studies analyzed influenza and respiratory syncytial virus tests, and 6 studies analyzed multiplex  testing. The prescription rate was 48.2% (496/1029) in the influenza and respiratory syncytial virus test group and 48.7% (540/1109) in the control group . The prescription rate in the multiplex testing group was 54.3% (1554/2859), and it was 57.3% (1336/2326) in the control group . In an age-stratified analysis, the prescription rates showed no evidence of a difference .We found moderate-quality evidence that rapid point-of-care testing for respiratory pathogens does not decrease the antibiotic prescription rate. Interventions to reduce antibiotic prescriptions are needed as overuse of antibiotics has been declared one of the key issues in medicine . AntibioPoint-of-care C-reactive protein testing has been shown to reduce antibiotic prescriptions . IntroduThe aim of this systematic review and meta-analysis was to analyze the impact of rapid point-of-care microbial testing of respiratory pathogens on antibiotic prescriptions in acute infections.We searched the PubMed, Scopus, and Web of Science databases on February 15, 2023. The complete search strategy is provided in the We included randomized controlled studies that compared rapid point-of-care viral and/or bacterial polymerase chain reaction (PCR) testing regardless of the blinding and comparator. We excluded all observational studies. Studies that did not present any original data  were excluded. Non-English-language reports were also excluded.Our main outcome was the antibiotic prescription rate. We defined antibiotic prescription as any antibiotic given for any indication during the study period. The secondary outcome was the antibiotic treatment duration in days. Stratified analyses between the test type , test setting (outpatients or inpatients), and age of the patients (children or adults) were conducted. “Multiplex test” means that a single sample is analyzed for several viruses and/or bacteria using the PCR method.The following data were extracted by 1 author from each included study to a predesigned Excel worksheet: authors, journal, country, setting, main outcomes, secondary outcomes, number of participants in each group, number of antibiotic prescriptions, antibiotic treatment duration.Cochrane Handbook of Systematic Reviews [This review was conducted according to the guidelines in the  Reviews . StudiesRisk of bias was assessed according to the Cochrane risk of bias 2.0 tool . Risk ofThe study protocol was registered with PROSPERO.Our search yielded a total of 754 unique items. After screening of titles and abstracts, we further assessed 19 studies and included 10 studies for analysis  13–15, . Five stThe overall risk of bias was high in 2 studies, had some concerns in 4 studies, and was low in 4 studies . Most isAntibiotic prescription rate was assessed in all 10 studies, with 7323 patients. The prescription rate was 52.7% in the intervention group and 54.6% in the control group  . We rankIn outpatients, the antibiotic prescription rate was 18.7% (138/789) in the testing group and 14.0% (113/805) in the control group  . The quaThree studies with 1603 patients analyzed the antibiotic prescription rate in children, and the rate was 25.9% (416/1603) in the testing group and 24.7% (310/1254) in the control group  . Five stFive studies with 2561 patients analyzed antibiotic treatment duration, and we found low-quality evidence that antibiotic treatment duration was not shorter in the intervention group  , Table 2Based on the findings of this review, rapid point-of-care pathogen testing in acute respiratory infections does not reduce antibiotic prescriptions or shorten treatment duration. Additional analyses based on the study setting and patient age did not show benefit of rapid pathogen testing in any of these subgroups.The findings of this study are consistent with the literature as all previously published randomized trials  have failed to show a reduction in antibiotic prescription rates. The reason for this is most likely the fact that, despite a viral pathogen finding, the decision to prescribe antibiotics comes from the clinical ensemble, where other laboratory parameters, such as C-reactive protein and white blood cell count, also play an important role. In addition to these considerations, there are also several nonmedical factors influencing the antibiotic prescription decision, such as patient preferences and physician attitudes , 29. TheBordetella pertussis, Chlamydia pneumoniae, or Mycoplasma pneumonia) as 3 of the outpatient studies used influenza and RSV testing [Hypothetically the beneficial impact of rapid viral testing would especially be seen in children, as children have a very high burden of viral infections . However testing , 25, 26. testing . Thus thFuture studies are needed to better guide antibiotic prescriptions and to reduce the burden of antibiotic treatment, especially in children, who are more susceptible to antibiotic-related short-term and long-term harms. A combination study of classic laboratory parameters, pathogen findings, and some novel biomarkers or tests could provide an algorithm-based approach to antibiotic prescriptions. Introduction of rapid quantitative analyses of viral loads in the respiratory tract may also help to predict the actual importance of microbial findings . HoweverOur main strength is that we did not have any notable protocol deviations. Most of the limitations came from the quality and heterogeneity of the included studies. Risk of bias rose mostly from the lack of blinding or improper randomization processes. Heterogeneity between the study settings, interventions, and comparators was clear and caused concerns. We aimed to control for this by conducting subgroup and sensitivity analyses, but the results remained similar in all subgroups. Due to these factors, the quality of evidence remained between very low and moderate.Our systematic review found moderate-quality evidence that rapid point-of-care testing for respiratory pathogens does not reduce antibiotic prescription rates. The antibiotic prescription rate was even higher in the outpatient setting in the point-of-care testing group. Further strategies and studies are needed to provide evidence-based interventions for antibiotic prescription reduction.ofad443_Supplementary_DataClick here for additional data file.


The impact that occurs on the runner’s foot when it lands on the ground depends on numerous factors: footwear, running technique, foot strike and landing pattern, among others. However, the surface is a decisive factor that can be selected by the runner to improve their sports practice, thereby avoiding injuries. This study aimed to assess the number and magnitude of accelerations in impact (produced by the runner when their foot strikes the ground) on three different surfaces  in order to know how to prevent injuries. Thirty amateur runners (age 22.6 ± 2.43 years) participated in the study. They had to run consecutively on three different surfaces at the same speed, with a three axis-accelerometer placed on the sacrum and wearing their own shoes. The results showed that the running impacts differed based on the type of surface. Higher mean acceleration (MA) and mean peak acceleration (PA) in the impacts were observed on concrete compared to the other two surfaces. There were small differences for MA: 1.35 ± 0.1 g (concrete) vs. 1.30 ± 0.1 g (synthetic track) SD: 0.43  and 1.30 ± 0.1 g (grass) SD: 0.36 , and small differences for PA: 3.90 ± 0.55 g (concrete) vs. 3.68 ± 0.45 g (synthetic track) SD 0.42  and 3.76 ± 0.48 g (grass) SD 0.27 , implying that greater impacts were produced on concrete compared to synthetic track and grass. The number of peaks of 4 to 5 g of total acceleration was greater for concrete, showing small differences from synthetic track: SD 0.23 . Additionally, the number of steps was higher on synthetic track (34.90 ± 2.67), and small differences were shown compared with concrete (33.37 ± 2.95) SD 0.30  and with grass (35.60 ± 3.94) SD 0.36 . These results may indicate a change in technique based on the terrain. Given the increasing popularity of running, participants must be trained to withstand the accelerations in impact that occur on different surfaces in order to prevent injuries. Running is one of the most practiced sports today, and its popularity is increasing, as evidenced by the increase in the number of participants in all the great marathons year after year. This growth in popularity has simultaneously been accompanied by an increase in the incidence of running injuries . RepetitSome populations, such as amateur runners, showed an injury prevalence of around 58%, with male runners with and without previous injuries making up 72.4% and 72.6% of this group, respectively . The cauOne of the concepts that should be clarified is the term “impact”; this term encompasses impact force peaks and impact acceleration peaks . The varOne approach to quantify these variables has been the use of instrumented insoles to design cushioned footwear to improve impact attenuation on aggressive surfaces ,12,13. AAccelerometers have been used to assess impact differences between running barefooted and running in shoes ,16,17, aAlthough impacts vary from surface to surface, amateur runners tend to use the same running shoes over different surfaces . In factTherefore, this study aimed to assess the number and magnitude of the accelerations in impacts produced by runners wearing their own shoes and running consecutively on three different surfaces: grass, synthetic track, and concrete. Another of the features of this study was the innovative location of accelerometers, near to the runner’s center of mass (CM). This could help to select the most suitable surfaces for a workout, which will help trainers and athletes to reduce the risk of injury. The hypothesis for the study is that running on concrete surfaces generates higher accelerations in impacts than running on grass and on a synthetic track, when the runner’s foot strike in landing on the ground.In this study, we proposed to position the accelerometers close to the CM of the individuals studied in order to record the magnitude and acceleration in the impacts from the most global point of the runner. Considering how these impacts may influence the runner in the race, this may enable trainers to look for facilities to plan training sessions and manage loads in such a way that the risk of injury to athletes can be reduced.In addition, from an ecological perspective, and taking into consideration what has previously been observed regarding changes of shoes, this research considers that if athletes can carry out this type of field test with the shoes they use in their training sessions, the results will present a more realistic picture of what happens in reality, bringing the results closer to the implementation of actions, which is not as far away as in other studies.A comparative, descriptive study design was applied wherein the participants had to run on three different surfaces  with an accelerometer registering the magnitude of the acceleration in the impacts in each step and on each surface.A total of 30 amateur runners, 8 females and 22 males  participated in the study. All of them were Sport Sciences degree students and amateur runners with good technique who were familiar with the facilities in which the study was carried out, and who had at least 2 years of experience. As an exclusion criterion, the athletes had to have no lower limb injuries in the last 2 years. Before the trial, the subjects were informed about the purposes and risks of the investigation, and each participant signed a written informed consent document in accordance with the Declaration of Helsinki . The stu®, Almería, Spain), with two three-axis-accelerometers (1000 Hz) that were securely placed on the sacrum, parallel to the lumbar spine, and strongly fixed with two Tarmak elastic straps   a. The ac France) b. Each p®, Almería, Spain), and filtered at 12 Hz using a Butterworth 4th order filter . This frequency was previously selected according to the residual analysis results [The data of accelerations in impacts were obtained using Qüiko software v. 0.905 , that is, the resultant acceleration obtained using the vectorial sum of the acceleration in each axis  registered during the impacts (measured in g).-The mean total acceleration (MA), that is, the average of the total accelerations registered during the impacts (measured in g).-The mean peak total acceleration (PA), that is, the average of the maximum total accelerations registered during the impacts (measured in g).-The number of peaks of total acceleration in the impacts (NI), that is, the number of maximum total accelerations registered during the impacts. All the NI were grouped considering their magnitude of acceleration, within the following ranges: 0 to <1 g, 1 to <2 g, 2 to <3 g, 3 to <4 g, and 4 to <5 g.-The number of running steps (NS), that is, the number of strides taken over 40 m.The variables defined below were obtained during the middle four consecutive steps made during running on each surface:The selected variables were naturally log-transformed to satisfy the data normality assumptions (Kolmogorov–Smirnov test). A mixed linear model was used to compare the effect of the terrain  as a fixed effect and of the athletes as a random effect on the running acceleration in the impacts. Magnitude-based inferences  were detDescriptive data of the MA, PA, NI, and NS of each surface for the synthetic track, grass, and concrete, respectively, are presented in In this study, a comparison of accelerations in impacts of amateur runners running at a constant velocity on three surfaces  was carried out. The results showed that the running impacts differed based on the type of surface, indicating that the runners possibly changed their running technique on the different surfaces.Higher mean and peak total accelerations in the impacts were observed while the runner ran on concrete, as compared to the other two surfaces. The findings imply that the runner is subject to greater biomechanical loads on concrete, as shown in previous studies ,6,26. ThThe results indicate that upon each runner´s foot striking the ground, around two peaks of acceleration were generated with each step. Comparing the synthetic track and concrete , a higheAnother important observation is that the number of steps was higher on the synthetic track and grass than on concrete . This inA novelty of this study was the definition of the variable number of peaks of total accelerations in the impacts (NI), and its classification according to its magnitude. In addition, the location of the sensor could also affect the data registered. The majority of the studies placed accelerometers on the tibia; on the proximal anteromedial aspects of the right tibia ; on the Previous research in biomechanics has shown that running technique varies based on velocity in running  and gaitGiven the increasing popularity of running, athletes must be trained to withstand different loads on different surfaces. Runners should train their technique on a combination of surfaces, and not just on a synthetic track. Running on a synthetic track and grass could be more suitable during training periods, as these surfaces produce fewer peak accelerations in impacts. Running on concrete could be limited to competitions in which this surface is usually chosen by the organizers of these events. On concrete, runners could try to increase their stride frequency to reduce the high acceleration in the impacts and, as a consequence, reduce the risk of injury. The hypothesis that running on concrete surfaces results in higher accelerations in impacts when the runner´s foot strikes the ground was confirmed; this indicates that prolonged training periods on such a surface could lead to an increased risk of injuries. Thus, runners are advised to use a combination of surfaces while preparing for competitions.


We aimed to develop a roadmap for conducting regular, sustainable, and strategic qualitative assessments of antibiotic use in medical institutions within the Republic of Korea.A literature review on the current state of qualitative antibiotic assessments was conducted, followed by one open round to collect ideas, two scoring rounds to establish consensus, and one panel meeting between them. The expert panel comprised 20 experts in infectious disease or antibiotic stewardship.The response rate for all three surveys was 95% (19/20), while the panel meeting attendance rate was 90% (18/20). The following long-term goals were defined to assess the annual use of antibacterial and antifungal agents in all medical institutions, including clinics. The panel agreed that random sampling of antibiotic prescriptions was the most suitable method of selecting antibiotics for qualitative assessment, with the additional possibility of evaluating specific antibiotics or infectious diseases that warrant closer evaluation for promoting appropriate antibiotic use. The plan for utilization of results from evaluation involves providing feedback while maintaining anonymity and disclosure. It includes a quantitative assessment of antibiotic prescriptions and resistance rates to compare against institutional benchmarks. Furthermore, it was agreed to link the evaluation findings to the national antibiotic stewardship programme, enabling policy and institutional approaches to address frequently misused items, identified during the evaluation.This study provides a framework for establishing a qualitative assessment of antimicrobial use for medical institutions at a national level in the Republic of Korea.The online version contains supplementary material available at 10.1186/s13756-023-01319-8. Qualitative assessments of antibiotic use play an essential role in antibiotic stewardship programs (ASPs), as they not only identify patterns of inappropriate antibiotic prescribing and establish intervention strategies but also evaluate the effectiveness of these interventions –4. GivenSince the 2000s, various countries, including Australia, the United States, Europe, and the Republic of Korea (ROK), have conducted qualitative antibiotic assessments, with approximately 20–55% of antibiotic prescriptions in these countries deemed inappropriate –11. AustTo ensure systematic and sustainable qualitative antibiotic assessments for effective implementation in ASPs, it is essential to develop a framework outlining the current assessment method and scope, as well as long-term goals for the future. Therefore, this study aimed to create a comprehensive framework for conducting regular and strategic qualitative antibiotic assessments in Korean medical institutions.A modified Delphi study was conducted between June and August of 2022, which included three rounds of online surveys and a virtual meeting with an expert panel. Panellists were selected to include a range of experts and policymakers involved in antibiotic use and stewardship . The expThe study process is outlined in Fig. The first round of the survey aimed to gather insights and ideas from the expert panel. A questionnaire consisting of open-ended questions and a summary of the literature review were distributed to the panel members via email /(N/2), where ‘ne’ represents the number of panel experts who rated a given item as ‘agree’, and ‘N’ represents the total number of panellists. CVR values ranged from − 1 to + 1, with higher values indicating greater agreement among experts. CVR values above the cut-off level  were generally considered to have achieved a sufficient level of agreement. The minimum CVR values were determined based on the number of experts participating in each round, which were 0.44 for 18 participants and 0.47 for 19 participants [We calculated content validity ratios (CVRs) to analyse the responses provided in the second and third surveys and select the items that showed the highest levels of agreement among the panel members. The formula used to calculate CVR was as follows: CVR = . Eighteen expert panellists (90%) participated in the virtual meeting , a shortage of qualified personnel, lack of institutional support (both scoring 4.84), limited awareness among management (4.79), the absence of computerised programs (4.42), inadequate long-term planning (4.05), and lack of agreed-upon evaluation criteria (3.84).Table Table Regarding ways to encourage organisations to participate in antibiotic quality assessments, ‘establishing payment/incentives  and incorporating the assessment into medical quality assessment or accreditation evaluation  were strongly recommended by the panellists. For reporting/feedback methods, there was a strong consensus for anonymised disclosure through reports with quantitative assessments of antibiotic use and resistance rates and for individual healthcare organisations to view their results through a private website . By contrast, publishing quality assessment results to the public or disclosing regional and national results to sites that reveal individual evaluation results of medical institutions, such as Health Insurance Review and Assessment Service (HIRA), was not preferred .Regarding strategies for linkage to ASPs, there was a positive consensus on reporting quality assessment results to management and staff within healthcare organisations . Additionally, a policy and regulatory approach  and the implementation of healthcare professional education initiatives  for frequent misuse of antibiotics identified in qualitative evaluation results were agreed upon by the experts . While there was positive consensus regarding public disclosure and the promotion of qualitative analysis results on antibiotic use among the general population, three experts remained neutral (16/19, CVR = 0.684; Table The significance of this study lies in the establishment of goals and detailed methods for conducting qualitative assessment of antibiotics, both today and long-term. Given the absence of standard recommendations for qualitative antibiotic assessments, the experts who participated in the survey were presented with various approaches currently being used in different countries. By identifying the strengths and weaknesses of these approaches, a more objective application of qualitative antibiotic assessments in the ROK can hopefully be achieved.The consensus reached regarding the long-term goal for qualitative assessment of antibiotics involved conducting annual assessments by the KDCA for antibacterial and antifungal agents. Antibiotics prescribed for specific periods will be assessed through random sampling, and evaluations will be conducted for particular antibiotics or diseases as needed. The short-term goals largely align with the long-term goals, except that primary hospitals, clinics, specialised medical institutions, and hospitals with fewer than 300 beds will not be included in qualitative antibiotic assessments. These findings indicate that infectious disease or ASP experts in the ROK acknowledge the significance of qualitative assessments of antibiotics, even at present, and agree on the necessity of expanding the assessments to eventually include clinics. There is currently no consensus regarding the frequency of antibiotic evaluations, with experts agreeing on an annual evaluation for the long term. In the short term, annual evaluations are deemed unfeasible owing to resource constraints. It may be necessary to initiate a 2–5 years cycle, but the long-term goal is to gradually increase the frequency of evaluations to an annual basis, as is currently done in Australia .Determining how to select the antibiotics to be evaluated is crucial, as it is connected to the required resources. In this study, there was a long-term consensus on using random sampling while also incorporating time periods. Evaluating all patients would be labour-intensive; therefore, random sampling presents a sustainable assessment method in the long run. In the ROK, qualitative assessments of antibiotic prescriptions were conducted in 2018 and 2019 using a 1-day complete enumeration and a 2-days random sampling method, respectively. Despite including more institutions in the second survey, the rates of inappropriate antibiotic prescriptions were similar in both surveys [Evaluating the duration of antibiotic use is an important aspect of qualitative assessment but is difficult to conduct using point surveillance methods . In 2021The lack of expert consensus on using HIRA data for qualitative assessment of antibiotic prescriptions to minimise the labour input required from individual institutions is noteworthy, as only 47.4% of respondents agreed to its use. This could be due to concerns surrounding code shifting and the unavailability of clinical data in the HIRA database, as previously reported . The surIt was agreed that after assessments are conducted, the feedback method should involve anonymising and publicly disclosing the data, as well as including it in the antibiotic use/resistance report. In the ROK, KONAS conducts quantitative assessments of antibiotics, and annual antibiotic resistance reports are published through Kor-GLASS, the Korean national antimicrobial resistance surveillance system based on the GLASS platform –25. The It is noteworthy that the entire expert panel agreed on the utilization of the results of the qualitative assessment for the national ASP. The qualitative assessment results enable physicians to identify antibiotics that are being prescribed incorrectly and can be used as evidence to improve the use of those antibiotics. The qualitative assessment implemented at a national level provide an opportunity to reduce the amount of antibiotics used inappropriately, which may be related to decrease in antibiotic resistance. It is expected that the integration of antibiotic qualitative assessment into healthcare quality assessment or the introduction of incentive systems will increase the interest and participation of medical institutions in ASPs. However, three experts in this Delphi survey took a neutral attitude to public disclosure and publicizing the results of the qualitative assessment. Therefore, the strategy for linking the results of the qualitative assessment and the national ASP needs to be discussed further.This study had some limitations. Firstly, there are several unanswered questions about conducting a large-scale, population-based assessment of antibiotic appropriateness. We did not discuss what criteria should be used to assess antibiotic appropriateness, how many cases should be sampled from each hospital, or who should actually perform the antibiotic appropriateness audits. Further research is warranted to address these questions. Secondly, the international applicability of this study is limited because the survey was only administered to experts in the ROK. However, the study framework itself could be used as a template in other countries, and the methodology presented could also be used to make country-specific adjustments. Lastly, consensus/closing criteria applied in studies using Delphi procedure are varied because there is no standard for that criteria . In thisThis Delphi survey established an expert consensus regarding both short- and long-term roadmaps for conducting qualitative assessments of antibiotics in the ROK. The plan for quality assessment of antibiotic use included target institutions, evaluation interval, assessment tool, methods for data extraction, and target antibiotics. The plan for utilization of results from evaluation included engagement in qualitative antibiotic assessment, reporting/feedback methods, and ASP linkage. This practice has not yet been standardised worldwide. Its outcomes are expected to promote active qualitative assessments of antibiotics and to appropriately link evaluation results to individual medical institutions and the national ASP.Additional file 1: A questionnaire consisting of open-ended questions and a summary of the literature review.Additional file 2. Table S1: The response rate of the expertise panel in each round. Table S2: Proposed plan for qualitative assessment of antibiotic use. Table S3: How to best use assessment data.