In view of the problems of traditional repair materials for anchorage concrete of expansion joints, such as ease of damage and long maintenance cycles, the design of polyurethane concrete was optimized in this article, which could be used for rapid repair of concrete in anchorage zone of expansion joints. A new type of carbon fiber grid–polyurethane concrete system was designed, which makes the carbon fiber grid have an excellent synergistic effect with the quick-hardening and high-strength polyurethane concrete, and improved the flexural bearing capacity of the polyurethane concrete. Through the four-point bending test, the influence of the parameters such as the number of grid layers, grid width, and grid density on the flexural bearing capacity of polyurethane concrete beams was tested. The optimum preparation process parameters of carbon fiber grid were obtained to improve the flexural performance of polyurethane concrete. Compared with the Normal specimen, C-80-1’s average flexural strength increased by 47.7%, the failure strain along the beam height increased by 431.1%, and the failure strain at the bottom of the beam increased by 68.9%. The best width of the carbon fiber grid was 80 mm, and the best number of reinforcement layers was one layer. The test results show that the carbon fiber grid could improve the flexural bearing capacity of polyurethane concrete. The carbon fiber grid–polyurethane concrete system provides a new idea for rapid repair of the anchorage zone of bridge expansion joints, and solves the problems such as ease of damage and long maintenance cycles of traditional repair materials, which can be widely used in the future. The bridge expansion joint’s anchoring zone is the most prone to damaged device in the bridge structure, and it is difficult to rapidly repair without interrupt traffic. Polyurethane concrete is a composite material composed of two components with polyurethane as the binder and cement and aggregate as the filler ,2, whichCurrently, many studies are more focused on the research of polyurethane cement, and aggregates have not yet been added to polyurethane concrete composite materials. Kexin Zhang evaluated the bonding performance of polyurethane cement by steel bar pullout test and flexural strength tests of concrete axial tension . Jifeng In this study, the carbon fiber fabric grid was designed to improve the flexural performance of polyurethane concrete composites, so as to play an important role in future maintenance and reinforcement fields. The fiber fabric grid is a unidirectional or bidirectional, natural or synthetic fiber tow arranged in a regular matrix with high strength and minimum weight. So it can be used as a reinforcement method for existing reinforced concrete components, and is suitable for the situations where steel bars cannot be used because of potential corrosion problems . Meier, Carbon fiber has many advantages such as excellent durability, high tensile strength and strong corrosion resistance. There is no requirement regarding the thickness of the protective layer of the corresponding concrete elements as long as they meet the transfer bond stress. Therefore, the carbon fiber fabric grid has obvious advantages in structural repairs ,21. In aAt present, there is relatively little research on the synergy of polyurethane concrete and carbon fiber grid, and the influence of carbon fiber grid on the flexural performance of polyurethane concrete has not been studied by predecessors. In this paper, the influence of the carbon fiber grid on the flexural performance of polyurethane concrete is discussed, which has a certain reference value for the future research and implementation of the carbon fiber grid–polyurethane concrete system.Polyurethane is generally defined as the polymer compound containing repeated polyurethane bond structure units -[-NH-CO-O-]- on the polymer backbone . The polThe organic polyurethane prepared by the reaction of combined polyether and PAPI is used as the main body. The more common and inexpensive cement is used as the filler, which is filled in the polyurethane and mixed with the aggregate to form an organic–inorganic composite material with high strength and toughness.(1)PAPI: Polymethylene polyphenyl polyisocyanate , macromolecule, increased structural integrity, and flexibility.(2)Combined polyether: Produced by Shandong Yisheng Polyurethane Co., Ltd. , the main ingredients are polyether polyol, silicone oil, epoxy catalyst EZ01, and a colorless transparent liquid at room temperature. The main material composition of the combined polyethers is shown in (3)Aggregate gradation: AC-10 fine-grained concrete typical gradation  and the (4)Cement: Portland cement (average particle size = 1.455 µm), produced by Yatai Group Harbin Cement Co, Ltd. . According to the T0502-2005 cement fineness test method, T0505-2020 cement setting time test method, and T0506-2005 cement mortar strength test method (ISO method) in “Testing Methods of Cement and Concrete for Highway Engineering” (JTG 3420-2020) . Under t(5)Reinforced material: There are three kinds of reinforced materials in this test: carbon fiber grid, steel-strand grid, and steel-wire grid. The carbon fiber grid is woven from multiple 24 K carbon fiber bundles. In the 24 K fiber type, each fiber bundle includes 24,000 carbon fiber precursors. The carbon fiber precursors used in this experiment were polyacrylonitrile-based carbon fiber precursors. The reinforced materials are shown in The mix proportion of polyurethane concrete is shown in To explore the influence of the type, width, number of layers, and grid density of reinforced materials on the flexural performance of polyurethane concrete, 13 groups of specimens were designed. The form of the reinforced material is shown in (1)Fabric cutting: Cut the carbon fiber grid, steel-strand grid, and steel-wire grid required for the experiment into suitable sizes.(2)Reinforced material handling: Fix both ends of the carbon fiber grid, steel-strand grid, and steel-wire grid on the iron fixed table. Prepare polyurethane solution, and the ratio of PAPI and combined polyether of polyurethane is 1:1. The polyurethane solution is fully mixed and evenly coated on the surface of the reinforced fabric by using a stirring rod. After the reinforced fabric is left standing for 5 min, prepare the bending specimens.(3)Polyurethane concrete configuration: First, dry the cement and aggregate at 100~110 °C for 2 h  to completely remove the free water. Then, mix the dried aggregate and cement thoroughly with the combined polyether. Lastly, pour the PAPI into the well-mixed mixture, stir for 6 min, and prepare to pour specimens. During mixing, the laboratory temperature is 20 °C.(4)Specimens pouring: Fix the 100 × 100 × 400 mm mold on the vibrating equipment and pour it in batches. Pour the mixed polyurethane concrete and use a steel ruler to calibrate the thickness of the pouring. After full and uniform vibration, a layer of treated reinforced material is laid on the surface. Then, pour the remaining polyurethane concrete into the mold, cover the surface of the fabric, and continue vibration. After the vibration is completed, the mold is removed from the vibration equipment, and the test is performed after curing for 24 h. The configuration process is shown in Some of the prepared specimens are shown in The schematic diagram and physical diagram of the sample model are shown in There are no relevant test procedures for polyurethane concrete, therefore, the four-point bending test was used to evaluate the bending performance of concrete ,27,28,29F—Ultimate load (N);L—Distance between supports (mm);b—Specimen width (mm);h—Specimen height (mm).At room temperature, when the polyurethane concrete beam is subjected to load, the load–deflection curve presents a linear elastic change, which is approximately a straight line. As the increase of load, cracks appear at the bottom, and then extend vertically, and the specimen is destroyed. At high temperature, when the specimen bears the load, the load–deflection curve shows a linear elastic change before reaching the failure load. With the increase of load, small cracks appear in the middle of the bottom of the pure bending section of the specimen, but then the crack in the middle of the bottom of the Normal-60 °C specimen expands vertically upwards, and the specimen is destroyed. However, after cracks appear at the bottom of the C-80-1-60 °C specimen, with the increase of load, the crack propagation direction changes from vertical propagation to vertical and horizontal propagation. The transverse cracks propagation is accompanied by energy consumption. At the same time, the carbon fiber grid and the upper polyurethane concrete are stressed together, which improves the flexural performance of the specimens, as shown in From the perspective of molecular structure, polyurethane is a kind of block polymer. Its molecular chain generally consists of two parts. At room temperature, one part is in a high elastic state, which is called soft segment. The other part is in a glassy or crystalline state, called a hard segment. Generally, the soft segment consists of flexible long chains of polymer polyol, and the hard segment consists of isocyanate. The soft segment and hard segment are alternately arranged to form a repeated structural unit. In addition to the carbamate groups, there are also a large number of polar groups in the polyurethane molecular chain, such as esters, ethers, and urea . BecauseThe load–deflection curves of polyurethane concrete specimens with different reinforced materials are shown in The failure strains of specimens with different reinforced materials along beam heights are shown in The average failure strains at the bottom of the beam are shown in The load–deflection curves of specimens with reinforced materials of different grid widths are shown in The failure strains along beam height of specimens with different carbon fiber grid widths are shown in The average failure strains at the bottom of the beam are shown in The average failure strains at the bottom of the beam are shown in The grid density of carbon fiber grid also affects the flexural performance of polyurethane concrete , as showThe average failure strain at the bottom of the beam is shown in Ductility is also one of the important factors for evaluating the deformability of specimens. The study of related RC beams uses ductility to evaluate the bending performance, such as Karimipour Arash et al. ,28. So tCohn and Bartlett  defined Under the conditions of high-temperature, the failure form of polyurethane concrete is plastic. The effect of carbon fiber grid on the flexural performance and ductility of polyurethane concrete was tested at 60 °C. The ultimate load of the C-80-1-60 °C specimen is 19.7% lower than that of C-80-1 specimen and still 40.1% higher than that of Normal-60 °C specimen, and i-2 is 35.7% higher than i-1, as shown in the (1)The reinforcement of carbon fiber grid on the flexural performance of polyurethane concrete is better than that of the steel-wire grid and steel-strand grid. The flexural strength of polyurethane concrete was reduced by laying of steel-wire grid. Compared with the Normal specimen, the flexural strength of the specimens reinforced by the carbon fiber grid and steel-strand grid increased by 47.7 and 13.3%, respectively.(2)The average ultimate load of the polyurethane concrete beam reinforced by the carbon fiber grid increased by 47.3% compared with that of the Normal specimen. The average failure strain of polyurethane concrete beam reinforced by the carbon fiber grid increased by 68.9% compared with that of the Normal specimen.(3)The best reinforcement layer of carbon fiber grid for strengthening the flexural capacity of polyurethane concrete is one layer, and the best reinforcement width is 80 mm. The number of longitudinal carbon fiber strips plays a significant role.(4)The density of the carbon fiber grid also affects the enhancement of flexural performance of polyurethane concrete. The optimal grid density is 20 × 20 mm, which shows better transverse force transmission than the other grid densities, and is more conducive to improving the flexural capacity of polyurethane concrete.Through the four-point bending test, the polyurethane concrete beams were tested, in order to obtain how the carbon fiber grid can improve flexural bearing capacity of polyurethane concrete. By analyzing the test results, the following conclusions can be drawn:


The influence of a wet environment on the fatigue behaviour of high-strength concrete has become more important in recent years with the expansion of offshore wind energy systems. According to the few investigations documented in the literature, the fatigue resistance of specimens submerged in water is significantly lower compared to that of specimens in dry conditions. However, it is still not clear how the wet environment and the moisture content in concrete influence its fatigue behaviour and which damage mechanisms are involved in the deterioration process. Here the results of a joint project are reported, in which the impact of moisture content in concrete on fatigue deterioration are investigated experimentally and numerically. Aside from the number of cycles to failure, the development of stiffness and acoustic emission (AE) hits are analysed as damage inductors and discussed along with results of microstructural investigations to provide insights into the degradation mechanisms. Subsequently, an efficient numeric modelling approach to water-induced fatigue damage is presented. The results of the fatigue tests show an accelerated degradation behaviour with increasing moisture content of the concrete. Further, it was found that the AE hits of specimens submerged in water occur exclusively close to the minimum stress level in contrast to specimens subjected to dry conditions, which means that additional damage mechanisms are acting with increasing moisture content in the concrete. Oneschkow et al. [Hümme [The number of fatigue-loaded concrete structures in wet environments has significantly increased in recent years with the expansion of offshore wind energy systems. Such structures are exposed to millions of load cycles within their service life due to wind, waves and rotor movement. In contrast to dry fatigue-loaded structures, a significantly higher water content in the microstructure of the concrete occurs as a result of the offshore exposure. Fatigue investigations documented in the literature indicate a significantly lower fatigue resistance of high-strength concrete specimens submerged in water compared to those exposed to dry conditions ,4,5,6,7.w et al. ,5,8). AcSørensen [Hümme [Although the phenomenon of the water-induced damage of cyclically loaded concrete has been recognised in the literature, there is still a pronounced lack of knowledge concerning the underlying damage mechanisms involved in the deterioration process. Various hypotheses regarding water-induced damage mechanisms have been documented in the literature, but these have not yet been experimentally validated Sørensen  and Hümmn [Hümme , for exan [Hümme .Well-instrumented fatigue investigations on high-strength concretes with varied moisture contents have been conducted in a joint project of the Priority Programme SPP 2020 ‘Cyclic Deterioration of High-Performance Concrete in an Experimental-Virtual Lab’, funded by the German Research Foundation. The main aim of the project was to investigate and describe the water-induced damage mechanisms of fatigue loaded high-strength concretes. A numerical model for water-induced damage mechanisms has been developed and implemented additionally to assess the hypotheses derived from the experimental fatigue investigations. The model is validated in further stages of the project from the results of microstructural investigations such as nuclear magnetic resonance (NMR) or nano-indentation testing. Moreover, the influence of load frequencies on the water-induced fatigue damage was investigated in another project.In this paper, the respective number of cycles to failure of fatigue loaded high-strength concretes with varied moisture contents are presented. The development of stiffness and acoustic emission (AE) hits are additionally analysed as damage indicators and discussed along with the results of microstructural investigations to provide insight into the moisture-dependent degradation mechanisms. A numerically phenomenological description of fatigue damage is presented by combining the phase-field approach to damage with a porous media theory. A local lifetime variable is obtained that reflects the progressive degradation of fatigue damage resistance.cmf,150 = 113 MPa. The second part of the investigation considering various load frequencies was carried out on a dry mix of high-strength concrete for which the detailed composition was not provided. The concrete used was assigned to the strength class C90/105, according to the manufacturer’s specifications and called HPC-1 in following.The first part of the fatigue tests was carried out on a reference dry mix of high-strength concrete in the Priority Programme SPP 2020 called RH1 ,14. The rding to  by usingh = 300 mm and diameter of d = 100 mm were used in the investigations. Regarding the manufacturing process, the concrete was filled into plastic formworks in two equal layers and each layer compacted on a vibratory table. The formworks were removed two days after concreting. The test specimens were cut at both ends and prepared by grinding and fine polishing to ensure a centric loading and a uniform stress distribution. The different moisture contents of the concrete were adjusted as outlined below. Cylindrical specimens with a height of series D were dried at 105 ± 5 °C to a constant mass, beginning at an age of 90 days. These specimens only contain non-evaporable, essentially chemically bound water in their microstructure. Specimens in series C were stored in a climate chamber under standardized conditions  for at least 90 days, beginning immediately after the concreting process. Moisture gradients are reduced and the specimens show a lower overall moisture content due to the long storage time. Direct moisture exchange between the test specimens and the environment was prevented in series M by sealing the specimens with aluminium-coated butyl tape immediately after the grinding process. Series WS consists of test specimens that were permanently submerged in water (directly after the concreting process until testing) and stored at a constant temperature of 20 °C. The test specimens in series D, C and WS were sealed before testing to prevent drying during the fatigue tests. The specimens in the seriesWST were stored in a manner similar to the WS series. However, these specimens were tested underwater without being sealed. Fatigue tests were carried out on concrete specimens with a minimum age of 90 days.Test specimens in WS, i.e., full saturation. One week prior to the fatigue exposure, the specimens were moisture-sealed with epoxy resin coating (except for the end faces) to prevent the samples from drying during testing.Microstructural investigations were carried out on mortar samples. Fresh concrete of the RH1 mix was sieved to 2 mm to retain the typical concrete matrix composition. This mortar was cast in tubes with a diameter of 10 mm, moisture-sealed during curing, cut to 30 mm lengths after 28 days and polished at the end faces. The specimens were stored for over 90 days submerged in water to receive moisture conditioning of type minS = 0.05, maxS = 0.65 and tf = 1.0 Hz. The reference compressive strength of the concrete was determined before the cyclical tests as the mean value of three compressive strengths by using the specimens from the same batch and storage conditions as in cyclical tests. An overview of the reference compressive strength for each concrete and the value of moisture content for each storage condition is given in WST series with different load frequencies of tf = 0.35, 1.0, 5.0 and 10.0 Hz to determine the impact of the load frequency on the water-induced fatigue deterioration. An overview of the number of macroscopic fatigue tests is given in The macroscopic experimental investigations were performed in a 2.5 MN class 0.5 servohydraulic testing machine (according to ISO 7500-1 ). A specThe axial force, axial deformations, surface temperature and AE activity were measured during all cyclical tests with a sampling rate of 300 Hz. The axial deformations of the specimens were measured using three laser distance sensors positioned on the circumference, each offset by 120° to the other. Six AE sensors with a wideband frequency response within the range of 250 to 1600 kHz were attached to the specimens. The sensors were positioned at 60° from one another, alternately in the upper and lower third of the specimen. A specific threshold value of 40 dB was selected to separate useful AE signals (AE hits) from the background noise . The meaWS. The samples were wrapped in cling film to prevent drying during the NMR measurement and placed in a BRUKER minispec mq10 instrument (0.235 T) with a custom probe head. The T2 relaxation from the CPMG sequence was recorded for 1600 repetitions  method were performed on moisture-sealed mortar samples from storage condition ues, see ). After milar to , to recemilar to  yielded (compare ). Despit. The S-N curves of DNV GL [fib Model Code 2010 [D and WST (Δ10 Nflog = 2.5). It should be mentioned that the result of the series D refers to one run-out, i.e., the real number of cycles to failure is unknown. The values of the storage conditions C and M are spread between the conditions WST and D, while the number of cycles to failure of the storage condition M is lower than for the condition C. The mean value of the storage condition C is located near to the value of fib Model Code 2010. It was found, additionally, that the results of numbers of cycles to failure of specimens in the series WS and WST are located close to each other. This indicates that the moisture content in the concrete—and not the wet environment—is substantially responsible for the accelerated fatigue damage. It is clear from A summary of the numbers of cycles to failure f DNV GL  for wet ode 2010  for dry WST. The impact of load frequency on fatigue behavior of high-strength concrete specimens with varied moisture contents are investigated and analysed by means of AE hits in further stages of the project. The test results for tf = 0.35 Hz show the lowest number of cycles to failure (10 Nflog = 3.69). By contrast, specimens loaded with the highest load frequency of 10 Hz reach the highest number of cycles to failure (10 Nflog = 4.42). Thus, the results suggest that the water-induced fatigue damage due to fatigue increases significantly with decreasing the load frequency.The numbers of cycles to failure depending on the load frequency are shown in sE) in the decreasing branch of the sinusoidal strain curve using the strains at the maximum and minimum (peak) stresses. Based on the development of stiffness in the fatigue process, the gradient, i.e., the stiffness degradation per load cycle, in phase II of the development of stiffness is also analysed as damage indicator. The slope of the development of stiffness in phase II, referred to as N/fN = 0.20 to 0.80 as follows:The stiffness degradation per load cycle was analysed throughout the test duration depending on the moisture content of the concrete. The stiffness was calculated for each load cycle as the secant modulus  and dry specimen (D) with a rapidly decrease of the values from −2.23 to −0.82. The rapid decrease might indicate that additional damage mechanisms are acting when a certain value of moisture content in the concrete is exceeded. The mean values of the logarithmic gradient of stiffness in phase II depending on loading frequency are plotted in tf = 10.0 Hz.The results are shown as mean values in In summary, the results of the logarithmic gradient of stiffness indicate that the value of stiffness reduction per load cycle increases with increased moisture content and decreased loading frequency. This correlates very well with the results of the number of cycles to failure.C . However, the number of AE hits (maxHit and minHit) increases rapidly in the last third of phases II and in phase III. By contrast, the AE hits of water-saturated test specimens occur mainly near to the minimum stress level (minHit). Hits close to the maximum stress level can only be observed at the end of phase II and in phase III. In the latter phase III, the number of AE hits increases rapidly in a manner similar to storage condition C. The difference in the AE signals and signal occurrence between both storage conditions indicates that additional damage mechanisms are acting with increasing moisture content in the concrete, which led to an accelerated degradation process due fatigue loading.The AE activity was analysed as a second damage indicator to obtain insight into the moisture-dependent fatigue deterioration of the concrete. C a and WS C .(6)Welollowing ,31,32, tHence, the fracture contribution cit form ,34, whereen used ,34. The According to the classical Terzaghi theorem, the constitutive modelling corresponds to Thus, the balance of linear momentum takes the following form:The fluid volume flux Here, the second-order permeability tensor K  is additflow PDE  within aThe fluid pressure p using Coleman-Noll inequality condition reads:Recall that the regularized fracture energy density Hence, the following form was adopted according to ,36, wherHere, Here, Here, The Macaulay bracket is used in this equation. For an alternative description of crack irreversibility, see . For recThe capability of the phase-field damage modelling due to the fatigue load is illustrated by a representative numerical example. The boundary value problem, and material properties, are described in previous works ,33. FollNext, the pressure evolution at a cut inside the high-strength concrete specimen is provided in The resulting force-displacement curves in the dry and water-saturated state are investigated in As an extension of the previous investigations, the influence of water saturation on damage under cyclical loading is considered. The number of cycles to failure versus forces for both dry and wet cases are presented in minS = 0.05, maxS = 0.65 and tf = 1.0 Hz). The impact of load frequency on the water-induced fatigue damage was examined additionally using load frequencies of tf = 0.35–10 Hz. The numbers of cycles to failure were determined and compared with S-N curves of DNV GL [fib Model Code 2010 [10 Nflog = 2.5 was found between water-saturated and dried concrete specimens.The number of cycles to failure showed a significant reduction with increasing moisture contents in the concrete. The largest difference in the numbers of cycles to failure of ΔThe moisture content in the concrete—and not the water as an environment—was identified as being primarily responsible for accelerated fatigue deterioration of concrete.The results for the development of stiffness showed an increased stiffness degradation per load cycle with increasing moisture content. The results indicated additionally the presence of a certain moisture content, beyond which different or additional mechanisms of fatigue damage arise.The water-induced fatigue damage was distinguished from conventional fatigue damage based on the occurrence of the AE hits. Compared to specimens stored in a climate chamber, the point of occurrence of AE hits of water-saturated concrete specimens shifts from a maximum to minimum stress level. This difference in the results confirms that additional damage mechanisms are acting with increasing moisture content in concrete, which lead to an accelerated degradation process due to fatigue loading.Investigations with respect to the influence of the load frequency show a significant reduction of fatigue resistance and increasing stiffness degradation per load cycle in phase II with decreasing load frequency.Tomann [Considering the moisture distribution results from NMR testing, moisture redistribution and degradation patterns were visible in the size range predicted by Tomann  for the The numerical results confirm that the fatigue effect for water-saturated concretes leads to a reduction in the damage resistance compared to dry concretes. The numerical prediction coincides well with the results from experiments.The purpose of the current paper was to determine the influence of the moisture content and the wet environment on the fatigue behavior of high-strength concrete. Experimentally, the fatigue tests were conducted on high-strength concrete specimens with different moisture content. The fatigue tests were carried out at constant stress levels and load frequency throughout the entire set of investigations regarding the impact of moisture content (f DNV GL  for wet ode 2010  for dry In spite of these findings and advances, a detailed understanding of water-induced damage mechanisms is still lacking. For this purpose, further microstructural investigations regarding porosity, pore size distribution and nanoscale moisture content are to be conducted in further stages of the research project. The impact of loading frequency and further parameter such as stress level on water-induced fatigue damage are investigated and analysed by means of AE analysis. The modelling of damage mechanisms is validated from the results of microstructural investigations.


Background: Acute respiratory infections (ARIs) are commonly treated with antibiotics in outpatient settings, but many infections are caused by viruses and antibiotic treatment is therefore inappropriate. FebriDx®, a rapid point-of-care test that can differentiate viral from bacterial infections, can inform antibiotic treatment decisions.Objectives: The primary aim of this study is to conduct a literature-based US economic evaluation of a novel rapid point-of-care test, FebriDx®, that simultaneously measures two key infection biomarkers, C-reactive protein (CRP) and Myxovirus resistance protein A (MxA), to accurately differentiate viral from bacterial infection.Methods: A budget impact model was developed based on a review of published literature on antibiotic prescribing for ARIs in the United States. The model considers the cost of antibiotic treatment, antibiotic resistant infections, antibiotic-related adverse events, and point-of-care testing. These costs were extrapolated to estimate savings on a national level.Results: The expected national cost to treat ARIs under standard of care was US $8.25 billion, whereas the expected national cost of FebriDx point-of-care-guided ARI treatment was US $5.74 billion. Therefore, the expected national savings associated with FebriDx® rapid point-of-care testing was US $2.51 billion annually.Conclusions: FebriDx, a point of care test that can reliably aid in the differentiation of viral and bacterial infections, can reduce antibiotic misuse and, therefore, antibiotic resistant infections. This results in significant cost savings, driven primarily by the reduction in antibiotic resistant infections. Clostridium difficile infections.Acute respiratory infections (ARIs) are common in outpatient settings and account for 41% of all antibiotics prescribed in ambulatory settings, about half of which are medically unnecessary.Antibiotic misuse is a significant economic burden on the health-care system. US antibiotic expenditure totaled US $8.8 billion in 2015, the majority of which was attributable to antibiotic prescribing in outpatient settings.Clinicians often rely on medical history and physical exams to determine if antibiotics are warranted, but physical examination alone has poor accuracy for diagnosis of ARIs.®  is an example of a rapid diagnostic test that provides both the clinician and patient with information about the cause of a patient’s infection to guide appropriate decisions about antibiotic prescriptions. The primary aim of this study is to conduct a US economic evaluation of FebriDx, a novel, rapid point-of-care test that simultaneously measures two key infection biomarkers, C-reactive protein and Myxovirus resistance protein A (MxA) to accurately differentiate viral from bacterial infection.Simple, inexpensive tests that can guide antibiotic prescription in the outpatient setting have been identified as a successful strategy to reduce inappropriate prescription of antibiotics.FebriDx is a 10-minute, point-of-care test that uses fingerstick blood to identify a host response to a bacterial or viral infection to identify which patients may require antibiotics. C-reactive protein is a non-specific acute phase protein that is elevated in both viral and bacterial infections and MxA is elevated in acute viral infections. MxA specifically recognizes newly synthesized viral nucleoproteins or nucleocapsid proteins and forms large intracellular MxA-nucleoprotein immune complexes that accumulate and aggregate in the cytoplasm of infected cells to inhibit viral replication.The diagnostic accuracy of FebriDx to distinguish between bacterial and viral ARI has been evaluated in multi-center US trials. The FebriDx test was determined to have both high sensitivity (up to 95%) to detect a bacterial infection and up to 99% negative predictive value to safely rule out a bacterial infection.This economic evaluation was developed based on a literature review of US-based ARI studies indexed on PubMed. The search for key model inputs was restricted to English-language studies of large, real-world US datasets, published between 2010 and 2020. Costs were estimated from a payer perspective, and all costs were inflated to 2020 US dollars using the Consumer Price Index.Three key populations were considered in the economic model: (1) the US patient population diagnosed with each ARI annually; (2) the patient population with each ARI condition treated with antibiotics under standard of care; and (3) the patient population for whom antibiotic treatment was appropriate. The overall and condition-specific population sizes were estimated from large US-based outpatient studies. The model included the costs attributable to antibiotics, follow-up care, antibiotic resistance, and diagnostic testing. Patients treated with prescription antibiotics incur the direct cost of the antibiotic. A subset of patients treated with antibiotics also incur the follow-up costs associated with treating drug-related adverse events in outpatient clinics, EDs, and hospitals. Patients treated with antibiotics also incur the cost of antibiotic resistant infections, regardless of whether the antibiotic prescription was appropriate.Patients suffering from ARIs who received antibiotics were typically prescribed penicillins, macrolides, cephalosporins, sulfonamides, or fluoroquinolones as monotherapy or combination therapy. The class of antibiotic depended on ARI condition, and each antibiotic was associated with specific adverse event rates and costs. The study assumed that all reported adverse events required follow-up treatment.The impact of FebriDx testing on antibiotic prescription rates was estimated based on test sensitivity and specificity. FebriDx can rule out viral infection with up to 95% sensitivity and 94% specificity.Tables S1 & S2 in the Online Supplementary Material). The size of each patient population is presented in US outpatient ambulatory care centers and EDs see about 57.9 million patient visits for ARIs annually.Antibiotics are necessary to treat some persistent or severe bacterial respiratory infections, but they are ineffective and inappropriate for treatment of viral infections.ARIs are commonly treated with penicillin, macrolide, and cephalosporin antibiotics. Fluroquinolone, sulfonamide, and tetracycline antibiotics are generally reserved for patients with a penicillin allergy.Patients treated with antibiotics experience a variety of adverse events including gastrointestinal distress, rash, anaphylaxis, and Stevens-Johnson syndrome.A longitudinal study of adverse drug events found that 73% of patients experiencing antibiotic-associated adverse events sought care in an outpatient clinic, while the remainder were treated in the ED.Each antibiotic had a unique distribution of adverse events, which occurred at different rates. For example, penicillin and sulfonamide antibiotics accounted for a larger proportion of adverse reactions than other antibiotic types.There are several types of antibiotics included in each class, but azithromycin, amoxicillin, amoxicillin-clavulanate, doxycycline, and levofloxacin were among the most common antibiotics prescribed for ARIs.The cost of second-line inappropriate antibiotics for viral conditions were also included when estimating the total cost of antibiotic treatment. Antibiotics are ineffective for viral conditions, and 8.9% of viral ARI patients return for a second antibiotic prescription when their symptoms are not resolved by the first antibiotic.The total expected cost of antibiotic treatment for ARIs was a weighted sum of the product of each cost and the probability of incurring the cost, calculated as follows:where $(outpatient visit)=US $245, $(ED visit)=US $1156, and $=US $14 679. The probability of each event was specific to the condition and antibiotic type as described in The expected national cost to treat ARIs under standard of care was US $8.25 billion, including the cost of antibiotics, antibiotic-related adverse events, and antibiotic resistance. Using a presumed Medicare reimbursement of US $23, the expected national cost associated with a FebriDx guided ARI treatment was US $5.74 billion and the savings associated with the use of FebriDx totaled US $2.51 billion. The benefit of FebriDx varied depending on the type of ARI .A sensitivity analysis was conducted to assess the cost drivers of the model by varying each parameter by 20%  and resuThe model is also sensitive to the reimbursed cost of FebriDx and the size of the population seeking treatment for ARIs. The cost of antibiotic resistance also has an impact because 100% of patients exposed to antibiotics incur the risk and the expected cost of an antibiotic resistant infection. Incidence of adverse events has a less significant impact on the model because although adverse events add considerably to cost of care, relatively few (11.02%) patients experienced adverse events that required follow-up care.Antibiotic stewardship efforts have increased in the United States in recent years, driven by the human and economic cost of antibiotic-resistant infections and adverse events.Although these results are encouraging, there are limitations to this model that should be considered. This model is literature-based and, therefore, there is some inherent uncertainty in model parameters. Although this uncertainty was mitigated by estimating parameters from large national studies where possible, the parameters are not all nationally representative. The real-world performance of diagnostics can also be influenced by patient characteristics, including the length of symptoms and the severity of the ARI, as well as disease prevalence. The model does not consider costs of “missed” bacterial infections because delaying antibiotics or using a “watchful waiting” approach does not significantly increase complication rates in most acute respiratory infections managed in an outpatient setting.This model demonstrates that use of FebriDx in the outpatient setting can lead to a considerable reduction in unnecessary antibiotic prescriptions, which will in turn lead to a reduction in antimicrobial resistance and adverse events. The model does not consider the benefits of enhanced workflow and efficiency in emergency and urgent care settings, rapid identification of bacterial infection, and the reduced risk of increased morbidity or sepsis associated with delayed treatment, nor does this model include costs of other testing and acceleration of antimicrobial resistance associated with the ongoing COVID-19 pandemic. Preventing antimicrobial resistance not only saves health-care costs, it also can prevent loss of life. It is estimated that 10 million people will die due to drug-resistant infection by 2050 if action is not taken to reduce misuse of antimicrobials.FebriDx is a simple, rapid point-of-care test that aids in the differentiation of viral from bacterial ARIs reducing the misuse of antibiotics and, therefore, combatting the growing threat of antibiotic resistance. FebriDx-guided ARI diagnosis demonstrated a US $2.51 billion cost savings compared to the standard of care approach of guiding antibiotic treatment of ARIs in US outpatient settings. The cost savings were driven by the reduction in antibiotic resistance associated with a lower antibiotic prescription rate as well as avoided return visits for drug related adverse events.


The aim of the research was to determine how the admixture of nanosilica affects the structure and mechanical performance of cement concrete exposed to high temperatures . The structural tests were carried out on the cement paste and concrete using the methods of thermogravimetric analysis, mercury porosimetry, and scanning electron microscopy. The results show that despite the growth of the cement matrix’s total porosity with an increasing amount of nanosilica, the resistance to high temperature improves. Such behavior is the result of not only the thermal characteristics of nanosilica itself but also of the porosity structure in the cement matrix and using the effective method of dispersing the nanostructures in concrete. The nanosilica densifies the structure of the concrete, limiting the number of the pores with diameters from 0.3 to 300 μm, which leads to limitation of the microcracks, particularly in the coarse aggregate-cement matrix contact zone. This phenomenon, in turn, diminishes the cracking of the specimens containing nanosilica at high temperatures and improves the mechanical strength. However, concrete is a quasi-brittle material, shows weak resistance to cracking and low tensile and flexural strength . The dev dioxide ,11.2 and new nanometric generation of superplasticizers (SP). Many investigations are carried out within the range of using carbon nanomaterials, mainly nanotubes and graphene, in the cement composites [In concrete technology, the nanosilica is used on the industrial scale as well as nanometric titanium dioxide TiOmposites . Most of2), commonly known as nanosilica. The nanosilica (NS) can replace in the future the silica fume (SF). NS reacts with lime (CH) during cement hydration and generates the production of hydrated calcium silicates (C–S–H) phase, improving the mechanical strength and durability of concrete [One of the best-recognized nanomaterials used in concrete technology is silicon dioxide . Such an approach is innovative in the description of the durability of the concrete modified with NS at high temperatures. After analyzing the mortars modified with nanoparticles ,40. For In addition, the method of preparing the specimens for the mechanical tests was in accordance with the standard laboratory method. A unique process of applying the commercial NS suspension to the mixing water was used to ensure the best possible NS dispersion in the cement matrix. The method has been previously developed by one of the authors . The tec3 was used for preparing the concrete and mortar specimens. The chemical composition of the cement is presented in 3. The grain size distribution curves of the sand and gravel are presented in 3. The size of NS particles was from 20 nm to 160 nm. The tap water conforming to EN 1008 [The ordinary Portland cement CEM I 42.5  with a specific density of 3.11 g/cm EN 1008  was usedThe constant water to cement ratio, w/c = 0.5, and contents of NS equal to 0, 1, 3, and 5% have been adopted in the designed cement pastes and concrete. The water contained in the dispersion was included in the mixing water. The paste specimens have been marked P0, P1, P3, and P5, according to the nanoadmixture content. The concrete specimens have been marked C0, C1, C3, and C5, according to the nanoadmixture content. The number corresponds to a percentage of the nanomaterial regarding the cement mass in the paste and concrete, respectively.Before mixing the liquid components of the pastes with cement, the given amount of NS was added to the mixing water . The obtPreparation of the concrete mixes consisted in mixing the aggregate with cement in the laboratory mixer. Then, 2/3 of the mixing water was added to the mixed dry components, and the mechanical mixing was continued. The NS dispersion was mixed with the remaining 1/3 of mixing water and prepared in the same way as in the case of the cement paste, agitating by 5 min. Next, the given amount of SP  was addeThe specimens were demolded after 24 h. Until testing, they were stored in water at the temperature of 20 ± 2 °C. Before structural and mechanical tests, the specimens were removed from the water and dried to the constant mass in the laboratory drier at temperature 105 °C.Transmission electron microscopic analysis (TEM) was used for the NS examination. The FEI Tecnai G2 F20 S . Twin equipment was used with an accelerating voltage of 200 kV. The scanning electron microscopy (SEM) (FE-SEM Hitachi SU8020) equipped with the Energy Dispersive Spectroscopy (EDS) analyzer  was used for the determination of elemental content. The samples were excited with 20 keV electrons during elemental analysis. Before analysis, the samples were thoroughly ground and placed over a double-sided conductive carbon tape glued to the carbon SEM stub.The particles size distribution was determined by Dynamic Light Scattering (DLS) with Zetasizer Nano ZS apparatus . The NS sample was 1000-fold diluted with deionized water until a transparent solution was obtained. The measurements were conducted immediately after dilution of the suspension and after 15 min of ultrasonication.Temperature programmed desorption measurements were carried out in the synthetic airflow  using a combined thermogravimetric (TG) and mass spectrometric (MS) analysis system consisting of the thermobalance  and a mass spectrometer . A heating rate of 10 K/min with the final temperature of 1000 °C was applied. The mass spectrometer was used as a detector to determine water  and carbon dioxide (m/z 44), both desorbing from samples during controlled heating in the thermobalance.The analyzed materials X-ray diffraction (XRD) patterns were collected by an Empyrean PANalytical X-ray diffractometer  equipped with a copper tube . The measurement range in the 2θ range was 5–55° with a step size of 0.05. The PDF-4 + 2020 International Centre for Diffraction Data database and High Score Plus software  were used for phase determination.SEM images of concrete specimens were taken using a Hitachi TM3000 electron microscope. After heating to 200, 400, 600, and 800 °C and at reference 20 °C, the cuboidal specimens with a few millimeter slices were cut from the concrete’s middle part. These cross-sections were then analyzed using an SEM microscope. The specimens were cut with a diamond saw. The surfaces of the concrete specimens were not additionally treated, which made it possible to observe the scratches and cracks resulting directly from the action of high temperature on the tested concrete.Mercury intrusion porosimetry (MIP) was applied to assess the concrete’s pore characteristics. The central sections were cut out from the cubical specimens 50 mm × 50 mm × 50 mm. Then specimens sizes were about 7 mm × 7 mm × 2 mm. The test samples were selected to contain both coarse aggregate and the cement matrix. For each composite, two tests were conducted to verify the repeatability of the results. Before the tests, the specimens were dried to constant mass at 40 °C. The mercury surface tension was set to 0.48 N/m, and the contact angle was 140 degrees upon intrusion. The samples were put into measurement cells and filled with mercury in a low-pressure chamber. Subsequently, the cells were inserted into a pressure chamber and subjected to high pressures (up to ca. 413 MPa).The tests of the mechanical properties of the concrete specimens were carried out at 20 °C and after heating at 200, 400, 600, and 800 °C. The specimens for heating were initially dried to the constant mass at 105 °C when they reached the age of 28 days. After weighing, the specimens were put into the medium-temperature oven  and heated. The heating cycle at the given temperature has covered the heat to the proper temperature at the rate of 1 °C/min, maintaining this temperature for one hour, and cooling at the rate of 1 °C/min . After hThe flexural strength was determined according to EN 12390-5 . Three-pThe compressive strength was determined according to EN 12390-3  on the c3SiO5—alite (C3S), (ICDD 00-049-0442); Ca2SiO4—belite (C2S), (ICDD 00-033-0302); Portlandite, Ca(OH)2 (ICDD 00-044-1481).Energy Dispersive X-ray Analysis gives elemental composition of cement pastes at 28 days . The vis2. The amorphous phase is not visible on the diffractograms but affects the absolute intensity of reflections. Therefore, for the samples with the addition of colloidal SiO2 , the absolute reflection’s intensity is lower than P0.All the samples exhibit similar phase composition to reference sample P0. The difference between the samples is the amount of amorphous phase SiO2O and CO2 within the time are shown in In The MIP method is widely used to describe porosity structure in porous materials, including cement-based composites . It is uModification of concrete with NS led to diminished porosity as compared to the reference concrete C0 in the case of two compositions, C1 and C3. Within the range from 30 to 300 μm, the specimens with NS have demonstrated slightly lower porosity than the reference concrete without the nanoadmixture. The admixture of NS significantly influences the porosity structure in the cement matrix, which is reflected in the average size of the pores and median of their volume in the specimens modified with NS . ConcernThe flexural strength results of the concrete specimens after 28 days of curing in the water at 20 °C are presented in An influence of high temperature on the flexural strength of the tested concrete specimens was evaluated for the samples initially heated to the constant mass at 105°. The initial drying to the constant mass is used in most temperature tests of concrete . The bigSimilar to the flexural strength, the most significant rise of the compressive strength in relation to the concrete C0 was observed for the concrete C3 containing 3% of NS. The growths of the compressive strength were 13, 17, 17, 16, and 18% at temperatures 105, 200, 400, 600, and 800 °C, respectively.Evaluation of the structural damages of the tested concrete was carried out based on the SEM observations of the heated concrete specimens. Since no cracks were observed at temperatures of 105 and 200 °C, these cases have been excluded from the analysis. The presence of NS limited the cracking in the cement matrix observed at 400 °C. Decomposition of the hydration products in these specimens is slower than in the unmodified concrete. The microstructural changes of the cement paste can be primarily attributed to the release of water and initiation of the hydrates’ decomposition. The TG analysis of the cement pastes  shows thThe increase of the flexural strength of the concrete modified with NS compared to unmodified concrete at 20 °C is slight, and for the tested specimens was a maximum of 5.7%. The obtained results are hard to compare to those reported in the literature due to the various compositions of the concrete, including multiple sizes and contents of the applied NS. However, some influence of NS on the flexural strength of the cement concrete is demonstrated. For the concrete C5, a downfall of the flexural strength in reference to the concrete without NS was noted, mainly due to the increased total porosity of the concrete C5. A positive effect of NS admixture on the flexural strength of concrete has been observed within the considered temperature range.The favorable effect of NS on the compressive strength of concrete at 20 °C was observed. The highest increase of the strength, by 13.7%, was noted for the concrete C3. It is hard to compare the obtained results with the investigations reported by other authors. The literature data show that the growths of the concrete strength in the presence of NS are smaller than for the cement pastes or mortars. According to the authors’ opinion, the NS content in the concrete C3 was so close to the optimum that despite the increasing porosity, the amount of water was sufficient to wet the NS particles and react to cement’s components to create more C–S–H phase with the higher stiffness. The above explanation has been indirectly confirmed by TG and MS investigations on the cement pastes.The presence of NS in the concrete improved the compressive strength at a high temperature. The effect was less significant than the flexural strength; the increase averaged about 20% within the temperature range from 105 to 600 °C. What is essential, at 800 °C, a favorable effect of NS on maintaining the compressive strength was also observed (an increase by 18% in relation to the concrete C0 in the case of the concrete C3). It has been observed that in specimens C3 at 800 °C, the main crack occurred in the cement matrix and not on the coarse aggregate border. The above phenomenon could be the reason for the higher residual strength at this temperature, which, in turn, could be evidence of strengthening the coarse aggregate—cement matrix contact zone. ITZ is a crucial place in ordinary concrete from the point of view of durability at a high temperature. The described phenomenon seems to be very interesting and needs further investigation.The improvement of the mechanical performance of the concrete containing NS at a temperature up to 600 °C is caused by compaction of the structure and the creation of the C–S–H phase with high stiffness (resulting from the longer silicate chain C–S–H). This explanation was confirmed by TG and MS investigations. The above assumptions require further testing with the use, for instance, the nanoindentation technique or atomic force microscopy.In general, a positive influence of NS admixture on the concrete mechanical performance at a high temperature was demonstrated. It has been confirmed that there is an optimum content of NS enabling the creation of the best structure at the given concrete composition, which, in turn, allows the improved concrete resistance to high temperature. For the tested concrete compositions, the optimum content of NS was 3% of the cement mass.The method of dispersing NS in the mixing water appeared ineffective in the case of the concrete C5. The superplasticizer content was too low to evenly disperse the large amount of NS in the cement matrix, which led to the increased porosity and worse mechanical performance of the concrete.On the basis of the conducted investigations of the structure and mechanical performance of the concrete modified with NS at the high temperature, the following conclusions can be formulated:


Antibiotic-tolerant bacterial biofilms are notorious in causing PJI. Antibiotic loaded calcium sulfate bead (CSB) bone void fillers and PMMA cement and powdered vancomycin (VP) have been used to achieve high local antibiotic concentrations; however, the effect of drainage on concentration is poorly understood. We designed an in vitro flow reactor which provides post-surgical drainage rates after knee revision surgery to determine antibiotic concentration profiles. Tobramycin and vancomycin concentrations were determined using LCMS, zones of inhibition confirmed potency and the area under the concentration–time curve (AUC) at various time points was used to compare applications. Concentrations of antibiotcs from the PMMA and CSB initially increased then decreased before increasing after 2 to 3 h, correlating with decreased drainage, demonstrating that concentration was controlled by both release and flow rates. VP achieved the greatest AUC after 2 h, but rapidly dropped below inhibitory levels. CSB combined with PMMA achieved the greatest AUC after 2 h. The combination of PMMA and CSB may present an effective combination for killing biofilm bacteria; however, cytotoxicity and appropriate antibiotic stewardship should be considered. The model may be useful in comparing antibiotic concentration profiles when varying fluid exchange is important. However, further studies are required to assess its utility for predicting clinical efficacy. Periprosthetic joint infections (PJI) present many challenges for orthopedic surgeons as the economic burden and incidence rate increases . These i4) hemihydrate void filler beads have also been used because they are compatible with many classes of antibiotics [To treat bacterial biofilm PJIs, antibiotics such as vancomycin and the aminoglycosides tobramycin and gentamicin are often mixed into bone cement to provide locally high concentrations and broad spectrum coverage against Gram positive and negative pathogens . Broad sibiotics  and becaibiotics ,12,13. Mibiotics .Elution kinetics of antibiotics within each body cavity is an important factor in treating bacterial biofilm infections. It is important for the antibiotics to maintain or surpass the minimum inhibitory concentration (MIC), as bacterial biofilms require higher than MIC concentrations for an extended time to eradicate biofilm bacteria . Whilst Staphylococcus aureus and Pseudomonas aeruginosa using a diffusion filter disc assay. We hypothesized that the addition of antibiotic loaded beads to an antibiotic loaded PMMA spacer would produce a greater area under the curve of antibiotics over 48 h than the PMMA spacer alone and the vancomycin powder would be rapidly washed out. Our primary outcome measure was the area under the curve (AUC) of antibiotic concentration at various timepoint over a period of 48 h. The aim of the present study was to develop a method to allow direct comparison of the antibiotic concentration profile when released from non-absorbable and absorbable depots compared to direct addition of antibiotic as a powder in an artificial draining knee model. We designed a continuous flow reactor system to mimic drainage rates following revision which was in the size range of a human knee, to support a full sized PMMA bone cement spacer as well as a clinically relevant number of absorbable calcium sulfate beads. Using this system, we measured the antibiotic profile kinetics of the three local antibiotic administration methods using Liquid Chromatography Mass Spectrometry (LCMS) and the potency of the antibiotic was confirmed against reference strains of −1.019, where y = flow rate and x = time, was calculated and used to determine the flow rates used in this study  A and tob10). The CSBv+tplusSpacerv+t released greater VAN concentrations than the Spacerv+t throughout the duration of the study, including up to a 2.3 log difference at 48 h (p = 0.0024) and were significantly different at 5 min, 3 h and every subsequent timepoint until the study was completed at 48 h .While VP had the greatest release of VAN for the first 30 min of operation A, after  at 48 h B .The CSBs of TOB A. The CS 5 and 6 B. This dv+tplusSpacerv+t achieved greater antibiotic AUC of TOB at all time points and was significantly greater at 12 and 24 h compared to the Spacerv+t alone  (p < 0.05). However, there was a steady increase in AUC achieved by the Spacerv+t and the CSBv+tplusSpacerv+t which became greater  than that of the VP at 12 h. The rate of increase in AUC achieved by the CSBv+tplusSpacerv+t was greater than the Spacerv+t alone which was significantly greater (p < 0.05) at all time points. The CSBctively) . For VANS. aureus UAMS-1  and the CSBv+tplusSpacerv+t for the first 20 min of operation. However, after 2 h of initiating flow rates, VP lost all potency .Against  potency A. SimilaP. aeruginosa PAO1, potency patterns demonstrated a similar trend to S. aureus . Against . aureus B. The SpIn our study, we introduce a continuous flow-through reactor system designed based on drainage in the human knee following PJI revision surgery, to study the antibiotic concentration profile over time based on the elution from antibiotic loaded PMMA bone cement, absorbable CSB and as a single bolus added in powder form. The continual replenishment of eluant creates an “infinite sink” for the antibiotic . Flow thThe fluctuating concentration profiles demonstrated the utility of the flow through system with variable flow. The vancomycin powder initially demonstrated high concentrations in the effluent but was steadily and rapidly washed out so that after two hrs it was below detection limits by LCMS A and faip = 0.0024). For tobramycin, the addition of CSB increased concentrations by a log difference of 0.77 (p = 0.014). The ZOI assays were generally consistent with the LCMS data showing that the antibiotics did retain potency after elution. The concentration kinetic profile of antibiotics released from PMMA and CSB was different from that of the powder bolus. There was an initial high concentration, which presumably occurred from burst release in the period between adding the eluant and the time taken to collect the first sample. There was then a steady decrease in concentration for the first hr or two before the concentration increased again. The increase can be contributed to the reduction in flow through flow rate, so while elution likely remained relatively constant over this time, the washout rate was reduced since the concentration in the system is equal to the rate of elution minus the rate of washout, assuming antibiotic is not being degraded. Such fluctuations would not be seen in release assays with periodic exchanges, however further clinical data or appropriate animal PJI models are required to demonstrate how well our model compares to antibiotic kinetics delivered locally in a human joint. While these patterns were similar for antibiotic loaded PMMA with and without CSB, the concentration of both vancomycin and tobramycin was higher when both were combined. A previous study used partial fluid exchange and found the addition of vancomycin loaded CSB to PMMA spacers increased concentrations of antibiotics administered . We foun of 0.77 B  and significantly greater at h 12 and 24 for tobramycin . Badha et al. reported the minimal biofilm eradication concentration (MBEC) on bone and muscle to be 100–750 ug/mL of a 1:1 vancomycin and tobramycin combination maintained for a minimum 24 h [v+tplusSpacerv+t, but only the CSBv+tplusSpacerv+t maintained levels above this concentration for the 24 h duration  at 2 h, however at later time points the CSBto elute . For botmum 24 h . Our modduration A. We acknowledge several limitations of this study. First, only one commercially available calcium sulfate material was used. Not all commercially available materials have the same ability to mix and may not have the same elution profile . Second,v+tplusSpacerv+t provided higher concentrations of antibiotics and a larger AUC at 24 and 48 h than other methods assessed. This suggests the combination of PMMA and CSB may present an optimal combination for killing biofilm bacteria; however, cytotoxicity and appropriate antibiotic stewardship should be considered. We further conclude that the model may be useful in comparing the antibiotic concentration profiles from different local applications when varying fluid exchange is important but recognized that the model is relatively complex to operate and that further in vitro and animal studies are required to assess its utility for predicting clinical efficacy.In conclusion VP initially resulted in the largest vancomycin concentrations, however, within 2 h, concentrations dropped below inhibitory levels. CSBA continuous flow reactor system  was desiOnce drainage flow was initiated, 2.5 mL of effluent samples were manually collected at 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, and 55 min, and 1, 2, 3, 4, 5, 6, 7, 8, 12, 18, 24, and 48 h thereafter. The samples were stored at −20 °C until ready for analysis when the samples were defrosted on ice to room temperature.For our antibiotic choice we used vancomycin (VAN) and tobramycin (TOB) as these antibiotics are commonly mixed into bone cement and absorbable beads in revision surgery to provide locally high concentrations over sufficient time to control biofilm bacteria ,34,35. v+t) of size 4.8 mm were prepared using Stimulan® Rapid Cure (SRC)  10-cc mixing kits. Then, 20 g of CaSO4 SRC powder was combined with 240 mg Tobramycin Sulfate (TOB)  and 1000 mg Vancomycin Hydrochloride (VAN)  [Antibiotic loaded calcium sulfate beads  . After c™ P SpeedSet™ Radiopaque Bone Cement construction kits . Each unloaded spacer (Spaceru) was prepared combining 40 g of Simplex™ PMMA bone cement powder and 20 mL of the methyl methacrylate liquid monomer included in the kit. The contents were mixed into a uniform paste that was added to a circular silicone mold mat of 3.45 cm in diameter . The spacers were removed after approximately 30 min at 20 °C [v+t) was prepared using the same protocol, but included adding 2 g VAN and 2 g TOB to the dry mixture before adding the liquid monomer similar to the CSBv+t procedure above. PMMA bone cement spacer mimics were prepared using Simplexat 20 °C . The antA VAN bolus of 1000 mg VAN powder (VP) was weighed out and directly poured into the reactor system immediately before initiating flow. Three different methods of antibiotic administration were studied: (a) an antibiotic-loaded spacer alone, (b) an antibiotic-loaded spacer and antibiotic-loaded CSB, and (c) an unloaded spacer and vancomycin powder bolus (VP). For the latter, the unloaded spacer was used to ensure similarity in volume and liquid levels between the three experimental arms. Each arm was performed in three independent replicates.Quantification of antibiotics was developed using a single quadrupole mass spectrometer coupled to a 1260 infinity II series liquid chromatography stack (LCMS) . Liquid chromatography separation was conducted with a Poroshell 120-SB-C18 column  . Determination of vancomycin and tobramycin concentrations were assessed based on an adaptation of a previously published method .In order to test our primary outcome and compare the antibiotic exposure provided by each administration method Prism 8 (Graph Pad Version 8.4.3) was used to determine the area under the curve (AUC) of antibiotic concentrations from the linear data. Using this software, the AUC was determined for the 2 h, 12 h, 24 h and 48 h time points for each antibiotic administration method and for both VAN and TOB concentrations.Pseudomonas aeruginosa PAO1  and Staphylococcus aureus UAMS-1  were used in this study to determine the antimicrobial potency of each effluent sample taken at different time points. P. aeruginosa and S. aureus were grown overnight in Tryptic Soy Broth  at 37 ℃ under shaker conditions (200 RPM). Each overnight culture was diluted 1%. Then, 100 µL of the diluted culture was added to a sterile Petri dish containing 24 mL of 1.5% Tryptic Soy Agar  and spread to cover the surface. Each plate was left to dry for approximately 10 min before adding six sterile filter discs  in a circular formation with one disc in the center. Then, 10 µL of each effluent sample was pipetted onto its corresponding disc then incubated for 24 h at 37 ℃. After incubation, an image was taken of each Petri plate to analyze the zone of inhibition (ZOI) using NIH ImageJ [To assess the VAN and TOB potency of each effluent sample, the zone of inhibition (ZOI) was measured using the Kirby-Bauer method . While tH ImageJ . ImageJ Each antibiotic administration arm was performed in independent triplicate runs and the average of each method was used for analysis. The LCMS data and AUC data were converted to the geometric mean by taking the Log of each value before calculating the average values used for analysis. Statistical comparisons between different antibiotic administration methods were completed through Excel (Microsoft Version 16.39) software using an unpaired two-tailed, Student’s t-test assuming equal variances. A P-value less than 0.05 was considered statistically significant.v+t values from CSBv+tplusSpacerv+t and then plotted.Log differences between antibiotic administration methods were completed for LCMS data through Excel (Microsoft Version 16.39). The log of each value was calculated before subtracting Spacer


Concrete undergoes shrinkage regardless of the influence of external forces. The deformation of concrete is crucial for the structural stability of high-rise and large-scale buildings. In this study, the shrinkage and compressive creep of 70–90 MPa high-strength concrete used in high-rise buildings were evaluated based on the curing conditions , and the existing prediction models were examined. It was observed that the curing condition does not significantly affect the mechanical properties of high-strength concrete, but the use of limestone coarse aggregate increases the elastic modulus when compared to granite coarse aggregate. The autogenous shrinkage of high-strength concrete is greater than that of normal-strength concrete owing to self-desiccation, resulting in a large variation from the value predicted by the model. The drying shrinkage was observed to be similar to that predicted by the model. Compressive creep was affected by the curing conditions, compressive strength, loading level, and loading age. The compressive creep of high-strength concrete varied significantly from the prediction results of ACI 209; ACI 209 was modified based on the measured values. The shrinkage and compressive creep characteristics of high-strength concrete must be reflected to predict the deformation of an actual structure exposed to various conditions. Concrete is a composite composed of cement, aggregate, water, and admixture. It is a nonhomogeneous material owing to its internal pores, which are absent in homogeneous materials such as iron. It may exhibit various deformation characteristics when compared to typical homogeneous materials. It undergoes various deformations based on the presence or absence of an external force. Autogenous shrinkage, drying shrinkage, and shrinkage caused by carbonation may be observed in the absence of an external force. Compressive creep is a physical phenomenon in which the deformation of a member under a continuous load increases over time even without the application of additional loads following the elastic deformation caused by loading; it is typically observed in the presence of an external force ,3,4,5,6.Recently, the use of high-strength concrete of 80 MPa or higher at construction sites has been increasing owing to the increasing demand for high-rise buildings. In general, high-strength concrete may have different elastic modulus depending on the type of coarse aggregate ,8. The eTherefore, various models have been developed to predict the behavior of concrete structures, which are expressed considering the concrete mix and the influence of the environment ,13,14,15Moon  comparedLee et al.  conducteHaranki  evaluateOjha et al.  evaluateAs explained earlier, further research is required on the applicability of the existing prediction models, and database construction is required for high-strength concrete. Additionally, the shrinkage and compressive creep of high-strength concrete must be predicted through experimental verification and the verification of the construction site conditions. For high-strength concrete, it has been reported that the difference between the measured and predicted values tends to increase with the increase in age ,20.Typically, the compressive creep test of concrete requires data for more than six months, and studies that can be used at actual construction sites remain limited ,22,23.In this study, the mechanical properties of 70, 80, and 90 MPa high-strength concrete based on limestone and granite coarse aggregates applied to high-rise structures are evaluated, and the shrinkage and compressive creep are analyzed based on the curing conditions. Furthermore, the existing shrinkage and compressive creep models are compared to produce modified formulas.In this study, high-strength concrete with water/binder (W/B) ratios of 0.24, 0.27, and 0.29 was used. The specimen ID of high-strength concrete was constructed using the compressive strength, curing condition, coarse aggregate condition, and fiber condition (90 MPa). The autogenous shrinkage, drying shrinkage, and compressive creep of high-strength concrete were then evaluated under sealed and unsealed conditions. v/v) was applied to secure the fire resistance performance of high-strength concrete, as shown in To control the compressive strength of high-strength concrete, the amount of binder and aggregate was adjusted, and the target slump flow and air contents were satisfied in all specimens. The compressive strength and elastic modulus of high-strength concrete based on limestone and granite coarse aggregates were evaluated to select coarse aggregates for high-strength concrete. In the compressive creep test, the loading level was set to 40% of the compressive strength at 28 days of age, and the measurements were performed for two years after loading. The creep strain was calculated by subtracting the instantaneous elastic strain and shrinkage immediately after loading from the total strain measured in the compressive creep test, as shown in The models used to predict the shrinkage and compressive creep of concrete have been proposed and modified by various researchers in previous studies. In this study, the prediction models that are mainly examined in South Korea were selected and compared with the experimental results for high-strength concrete.The autogenous shrinkage and drying shrinkage of high-strength concrete were compared with the CEB code  and EuroWhen a comparison is performed for 90 F to compare the compressive strength based on the fiber addition, it is observed that the compressive strength tends to decrease by approximately 3% when fibers are added . AdditioIn this study, the shrinkage behavior was evaluated until 180 days of age to compare and examine shrinkage behavior at early ages.−6);−6);onstants ;The results of the autogenous shrinkage measurement of high-strength concrete were compared with the autogenous shrinkage prediction formulas of Eurocode 2 and the CEB code. The autogenous shrinkage measurements of high-strength concrete were approximately twice as high as the autogenous shrinkage values predicted using Eurocode 2 and the CEB code.Miyazawa and Tazawa  proposedTherefore, the compressive creep under the unsealed condition (drying creep) is significantly affected by the drying shrinkage, and this influence is expected to decrease as the compressive strength increases. Additionally, it is observed that the measured drying shrinkage values of high-strength concrete are similar to the predicted drying shrinkage values of Eurocode 2 and the CEB code.When fibers are added, the autogenous shrinkage and drying shrinkage are reduced by approximately 2–4%. This is because the fibers restrict the concrete matrix and inhibit moisture movement .At 720 days of age, the compressive creep coefficients of (90 N), 90 F, 80 F, and 70 F are 0.45, 0.39, and 0.36 under sealed conditions and (0.69), 0.71, 0.81, and 1.05, respectively, under unsealed conditions. The compressive creep coefficient under the unsealed condition is approximately 1.58 to 2.91 times higher than that under the sealed condition. This can be attributed to the fact that no drying shrinkage is observed under the sealed conditions. The difference in the compressive creep coefficient decreases with the increase in the compressive strength. This is because the drying shrinkage decreases with the increase in the compressive strength. Loading is applied to concrete after 28 days of age during the laboratory tests. However, it is necessary to consider both autogenous shrinkage and drying shrinkage for actual buildings because concrete structures are fabricated based on the construction period.Under the unsealed condition, the compressive creep coefficient of 90 MPa concrete increases by approximately 3% owing to fiber addition. This can be attributed to the fact that the interfacial structure of concrete is weakened and the creep strain increases owing to the addition of fibers with a lower elastic modulus than that of concrete ,33.When the compressive creep coefficient of high-strength concrete is analyzed using ACI 209, the predicted values are evaluated to be approximately 1.42 to 2.07 times higher than the measured values under the unsealed condition and approximately 2.13 to 2.65 times higher under the sealed condition. The prediction of compressive creep using ACI 209 is the method mainly used in Korea. However, this method cannot reflect the compressive creep characteristics of high-strength concrete with a strength of 70 MPa or higher. Additionally, the increase in the difference in the compressive creep coefficient is attributed to the high elastic modulus of high-strength concrete based on limestone coarse aggregate .Additionally, the total strain calculated by the compression creep coefficient predicted by using ACI 209 is significantly different from the measured total strain regardless of the curing conditions, as shown in The compressive strength and elastic modulus of high-strength concrete were evaluated to be approximately 2% higher under the sealed condition than under the unsealed condition based on the curing conditions. This is attributed to the moisture conserved in the concrete under sealed conditions. Additionally, the compressive strength and elastic modulus of the high-strength concrete increased by approximately 4% when limestone coarse aggregate was used.The autogenous shrinkage increases, and the drying shrinkage decreases with the increase in the compressive strength of the concrete. Particularly, the autogenous shrinkage of high-strength concrete increases owing to the self-desiccation caused by the hydration of unhydrated cement, which cannot be implemented by the existing models. Autogenous shrinkage and drying shrinkage occur simultaneously under the unsealed conditions in actual structures. Therefore, both autogenous shrinkage and drying shrinkage must be considered to predict the overall shrinkage of high-strength concrete. Furthermore, modified formulas were derived using the autogenous shrinkage prediction model proposed by a previous study, which reflected the autogenous shrinkage development characteristics of high-strength concrete.The compressive creep coefficient of high-strength concrete was evaluated to be approximately 1.58 to 2.91 times higher under the unsealed condition than under the sealed condition based on the curing conditions and was also affected by the compressive strength, loading level, and loading age. Additionally, the coarse aggregates affect the elastic modulus and compressive creep of high-strength concrete, which varies depending on various conditions, which cannot be reflected by the existing models. The shrinkage and compressive creep characteristics must be reflected to improve the prediction accuracy for the deformation of high-strength concrete because actual structures are exposed to more conditions than in laboratory tests. Therefore, ACI-209 proposed modified formulas to derive the ultimate creep coefficient by reflecting the compressive creep characteristics of high-strength concrete based on the curing condition and compressive strength.High-strength concrete has different internal structures because it contains more binders than normal-strength concrete. Therefore, the shrinkage and compressive creep of the main structural members must be accurately predicted to ensure structural stability in high-rise buildings where high-strength concrete is used. The accurate prediction of the deformation characteristics of high-strength concrete requires the construction of databases considering conditions such as compressive strength, curing condition, and coarse aggregate. In addition, future studies should investigate the correspondence between the compressive deformation of concrete members of buildings and the predicted values of the compressive deformation of concrete based on material values.


Background: Disruption of alternative splicing (AS) is frequently observed in cancer and might represent an important signature for tumor progression and therapy. Exon skipping (ES) represents one of the most frequent AS events, and in non-small cell lung cancer (NSCLC) MET exon 14 skipping was shown to be targetable. Methods: We constructed neural networks (NN/CNN) specifically designed to detect MET exon 14 skipping events using RNAseq data. Furthermore, for discovery purposes we also developed a sparsely connected autoencoder to identify uncharacterized MET isoforms. Results: The neural networks had a Met exon 14 skipping detection rate greater than 94% when tested on a manually curated set of 690 TCGA bronchus and lung samples. When globally applied to 2605 TCGA samples, we observed that the majority of false positives was characterized by a blurry coverage of exon 14, but interestingly they share a common coverage peak in the second intron and we speculate that this event could be the transcription signature of a LINE1 (Long Interspersed Nuclear Element 1)-MET  fusion. Conclusions: Taken together, our results indicate that neural networks can be an effective tool to provide a quick classification of pathological transcription events, and sparsely connected autoencoders could represent the basis for the development of an effective discovery tool. In humaer 2020)  has beenhttps://pubmed.ncbi.nlm.nih.gov/, accessed on 01 March 2021) we observed that the identification of this skipping event is mainly done using DNA-based amplicon-mediated target enrichment [Notably, MET exon 14 skipping is the only ES event encompassing a massive number of citations (119 from 2015 to 2021 reported in the PUBMED repository). MET exon 14 skipping is a splicing aberration that results in deletion of the MET juxtamembrane domain, which contains negative regulatory sites of the MET receptor. Thus, exon 14 deletion results in impaired receptor ubiquitin-mediated receptor degradation, decreased turnover and increased downstream signaling ,9. MET erichment , where trichment . We neverichment ,18 predirichment  a convolTo the best of our knowledge, we did not find any tool designed specifically to detect an exon skipping event as MET exon 14 skipping. In this manuscript, we investigated different neural network architectures to provide sensitive and rapid detection of MET exon 14 skipping events using RNAseq data. Standard Neural Network (NN), Convolutional Neural Network (CNN), and a Sparsely Connected Autoencoder (SCA) were thus compared in detail on different datasets. With respect to models predicting ES events, as well as other generalist CNNs ,22, whicTo detect MET exon 14 skipping events, an NN made of six layers was built; As a training set for the NN, we used data from amplified WT MET and exon 14 skipping MET .Specifically, we split the MET reads in random non-overlapping subgroups of 1000 reads. Although at 1000 reads, coverage of the detection of METΔ14 becomes a bit blurry—Each of the above-mentioned subgroups was converted in 31 and 16 k-mers. MET expression was represented by the amount of each k-mers spanning over MET exons, and these data were used to train the NN. We observed that the learning curve at 16 k-mers was slightly better than the one at 31 k-mers (not shown), and thus we ran the following analyses using the 16 k-mers representation of MET. As training sets, we also used k-mer count frequency  for fullAs test sets, we used subsets of WT and exon 14 skipping MET from cell lines characterized by a physiological MET expression. NN performance was investigated using as test set: (i) subsets made of random not overlapping subgroups of 500, 1000 and 5000 reads, converted in 16 k-mer counts, (ii) k-mer count frequency on full MET locus, (iii) k-mer count frequency on MET exons 13 ÷ 15 and (iv) coverage frequency for MET exons 13 ÷ 15.The detection efficiency of METΔ14 using 16 k-mers frequency counts showed best performances at 500 and 1000 reads coverage, To validate the METΔ14 discovery potential of the above-described NN, we used a set of 690 RNAseq samples from the TCGA bronchus and lung dataset. The 690 samples were manually inspected using the Broad’s integrative genomics viewer (IGV)  and we dUsing the NN trained with the coverage frequency for MET exons 13 ÷ 15, we extended the METΔ14 discovery to 2605 TCGA tumor tissues; We could detect only one METΔ14 in 280 bladder samples. Then, we detected few false METΔ14 in cervix, corpus uteri, heart/mediastinum/pleura, kidney and skin samples, The above observation also applies to the other false METΔ14 detected in corpus uteri, heart/mediastinum/pleura, kidney and skin samples; supplementary A possible explanation could be that we are observing the transcriptional effect of a LINE1-MET fusion, which was firstly described a few years ago in triple negative breast cancers . We furtTo detect MET exon 14 skipping events, we constructed a CNN made by a 1D convolutional layer, 1D Max pooling layer, a flat fully connected dense layer with 50 nodes and an output layer with one node; The results are organized  on the bWe validated the CNN model using the kernel 100, which is one of the best performing kernels independently by the coverage of the test set . The valOur group have recently published a paper on the use of SCA for the identification of hidden functional regulatory elements in single cell RNAseq data . We testWe used MET exon 14 skipping as a case study for the detection of genetic variants in cancer driver genes through deep learning. In recent years, a lot of evidence has indicated that MET inhibitors have a good anti-tumor effect in patients with MET exon 14 skipping mutation, suggesting that MET exon 14 skipping may be a new target for NSCLC patients . Thus, tIt is notable that, digging into the published literature, all the found exon skipping tools use nucleotide sequence analysis to infer skipping events, and they are only able to predict skipping events in a generalist way. Since we could not find any tool providing the detection of a unique skipping event in a gene over a large cohort of specimens, we designed specific neural networks for the identification of MET exon 14 skipping, using transcript expression information. We designed a conventional neural network (NN) made of four fully connected hidden layers and a convolutional neural network (CNN) made of one 1D convolutional layer, one 1D max pooling layer and a fully connected dense layer. Although we performed an automated optimization of the hyperparameters, the prediction efficacy of our CNN and NN comes from the special attention we put on defining the optimal representation of the data for each architecture, i.e kmer counts for CNN and coverage from NN.The NN and the CNN training was done using the RNAseq data of a lung cancer cell line expressing amplified form of the wild type MET , and a gastric cancer cell line expressing exon 14 skipped MET (HS746T). HS746T cell line was selected because, to the best of our knowledge, it is the only cell line displaying amplification of MET exon 14 skipping isoform. MET gene amplification has been observed in about 2–5% of gastroesophageal cancers and represents an oncogenic driver and therapeutic target ,32. MET https://www.cancer.gov/tcga, accessed on 1 March 2020) bronchus and lung collection (1310 samples) showing a MET coverage of at least 5000 reads. Given the manual curation of this dataset, i.e., each single sample was inspected on IGV browser for the presence of MET exon 14 skipping, it represents a robust instrument to quantify the predictive performance of our neural network models.Since we could not compare our models with respect to pre-existing methods for MET exon 14 skipping, we manually curated a set of TCGA data to provide an objective evaluation of the performance of our tool. Specifically, we manually curated a cohort of WT and exon 14 skipped samples made of the 690 RNAseq samples belonging to the TCGA . Notably, the high sensitivity is obtained by CNN with a training based on kmer counts spanning among MET exon 13 and exon 15. Instead, in the case of the NN the optimal sensitivity was obtained with a training based on coverage data encompassing the region among MET exon 13 and exon 15.Our analysis, using both CNN and NN, on 2605 TCGA tumors ; NCI-H596 (lung adenocarcinoma); Hs746T (gastric adenocarcinoma) cell lines were purchased from ATCC ; EBC-1  were acquired from HSRRB cell bank . All cells were kept in culture for less than 4 weeks and used between passage 2 and 10. Cells were grown in recommended media  supplemented with 50 units/mL penicillin , 50 mg/mL streptomycin , 2 mM glutamine  and 10% Foetal Bovine Serum  as indicated. Cells were maintained at 37 °C in a 5% COWe generated RNAseq data from EBC-1 , a non-sTotal RNA was extracted from cell lines using Trizol reagent , following the manufacturer indication. Total RNA was quantified using the Qubit 2.0 fluorimetric Assay  and sample integrity, based on the RIN (RNA integrity number), was assessed using an RNA ScreenTape assay on TapeStation 4200 .https://github.com/relipmoc/skewer accessed on 1 March 2021) Read were mapped using STAR on ENSEMBL HG38 human genome assembly.Libraries were prepared from 400 ng of total RNA using the RNAseq  sequencing service (Next Generation Diagnostics srl) which included rRNA-Globin depletion, library preparation, quality assessment and sequencing on a NovaSeq 6000 sequencing system using a paired-end, 300 cycle strategy (2 × 150) . Read were trimmed to remove adapters sequences using skewer  was generated using the cell lines with MET amplification: EBC-1 and Hs746T. EBC-1 and Hs746T reads were organized in subgroups of 1000 reads, randomly selected and not overlapping. This approach generated a large set of samples for the training the NN, i.e., 1447 subsets for EBC-1 and 846 for Hs746T. Subsampled reads were associated to MET exons  was generated using the cell lines with physiological MET expression: A549 and NCI-H596. A549 and NCI-H596 reads were organized in subgroups of 500, 1000 and 5000 reads, randomly selected and not overlapping. Subsampled reads were associated with MET exons  was generated using the RNAseq data used for the 16/31 k-mers training and test sets. For the training, reads were organized in subgroups of 1000 reads, randomly selected and not overlapping, for the test set, reads were organized in subgroups of 500, 1000 and 5000 reads. Subsampled reads were used to calculate coverage associated with MET exons 13, 14 and 15.We registered a TCGA project for the study of MET exon 14 skipping events, to obtain access to TCGA raw sequencing data, i.e., RNAseq BAM files. Since the size of the TCGA transcription data exceeds 200 TB, we progressively downloaded the BAM files on the basis of the cancer tissue locus. Then, from each BAM file, we extracted the reads encompassing MET locus . We kept only samples where the MET locus was covered by at least 5000 reads. To define 5000 reads as the minimal coverage for MET, we inspected the expected coverage for exons 13, 14 and 15 in A549 (WT MET cell line), in NCI-H596 (METΔ14 cell line) and in random subsets of 5000, 1000, 500 and 250 reads from NCI-H596, https://github.com/autonomio/talos, accessed on 01 January 2021), which is an automated tool to define the optimal combination of the hyperparameters. Specifically, Talos takes as input the hyperparameter space to be investigated. Then, Talos performs all possible combinations and selects the optimal configuration of the hyperparameters.We constructed a NN made of 6 layers. The input layer has variable size depending on the type of input (k-mers or coverage). 1st and 2nd hidden layers are made of 256 nodes, 3rd and 4th are made of 128 nodes, all using RELU (rectified linear unit) as activation function and 0.1 as dropout rate. The output layer is made by 1 node, associated with a sigmoid activation function. We implemented the models in python (version 3.7) using TensorFlow package (version 2.0.0), Keras (version 2.3.1), pandas (version 0.25.3), numpy (version 1.17.4), matplotlib (version 3.1.2), sklearn (version 0.22), scipy (version 1.3.3). Optimization was done using Adam (Adaptive moment estimation), with the following parameters lr = 0.01, beta_1 = 0.9, beta_2 = 0.999, epsilon = 1e−08, decay = 0.0, loss = ‘mean_squared_error’. Hyperparameter optimization was done using Talos  using TensorFlow package (version 2.0.0), Keras (version 2.3.1), pandas (version 0.25.3), numpy (version 1.17.4), matplotlib (version 3.1.2), sklearn (version 0.22), scipy (version 1.3.3). Optimization was done using Adam (Adaptive moment estimation) using the following parameters lr = 0.01, beta_1 = 0.9, beta_2 = 0.999, epsilon = 1e−08, decay = 0.0, loss = ‘mean_squared_error’. Hyperparameter optimization was done using Talos as done for NN.Autoencoders learning is based on an encoder function that projects input data onto a lower dimensional space. Then, autodecoder function recovers the input data from the low-dimensional projections minimizing the reconstruction. We implemented the models in python (version 3.7) using TensorFlow package (version 2.0.0), Keras (version 2.3.1), pandas (version 0.25.3), numpy (version 1.17.4), matplotlib (version 3.1.2), sklearn (version 0.22), scipy (version 1.3.3). Optimization was done using Adam (Adaptive moment estimation) with the following parameters lr = 0.01, beta_1 = 0.9, beta_2 = 0.999, epsilon = 1e−08, decay = 0.0, loss = ‘mean_squared_error’. RELU (rectified linear unit) was used as activation function for the dense layer.Taken together, our results indicate that neural networks can be an effective tool to provide a quick classification of pathological transcription events, and sparsely connected autoencoders could represent the basis for the development of an effective discovery tool in this field.