Wasted concrete was often used as a recycled aggregate instead natural stone in fresh concrete to reduce the environmental impact in a decade. However, because of the residual mortar interface, the performance of recycled aggregate was weaker. In this paper, the recycled aggregate was prewetted, and the effects of prewetted degree on the workability, strength, and durability of concrete were studied. The properties of the interfacial transition zone (ITZ), including microhardness, pore structure, and width, were also investigated. The results show that the workability intensity increased with the increase in prewetted degree from 0% to 100%, while the strength was first increased and then decreased with the optimal value of 43.3 MPa when the prewetted degree was 50–65%. The water absorption and chloride ion diffusion coefficient were also decreased by approximately 10% at minimum with the prewetted degree around 55% because of the declined fraction of pores larger than 50 μm and smaller porosity. The width of ITZ was first sharply decreased with a prewetted degree of 50–65%, then increased again with higher moisture, while microhardness of the ITZ showed the opposite trend and reached 82.7 MPa at maximum, at 50%. The appropriate moisture (50–65%) improved the pore structure and hydration products with an internal curing effect. When the moisture content was too high, the excess water was released from aggregate to the matrix, causing a higher water–cement ratio at ITZ; the porosity and the number of macrospores were increased to weaken the performance of concrete. With the rapid development of urbanization and industrialization, a huge amount of construction waste is generated every year ,2. In ChCompared with natural aggregates, the surface of recycled aggregates is usually attached to old mortar, so the physical properties, especially water absorption and crushing index, are significantly different ,17,18,19The old mortar attached to wasted concrete plays a key role in aggregate quality. Akbarnezhad et al.  found thSince the wasted concrete with porous attached mortar increased the water absorption, which was harmful to the strength and compact microstructure of concrete, the absorbed water could also play the internal curing effect to improve the interface properties of concrete. Yang  proved tIn this paper, recycled pure mortar aggregate was used to partially replace natural aggregate, and the moisture content of recycled aggregate was controlled by prewetting treatment. The effect of recycled aggregate with different moisture content on mechanical properties and durability was studied, and the interfacial structure of recycled concrete was investigated to reveal the mechanism of the internal curing effect of the prewetting recycled aggregate. The biggest highlight of this paper is exploring the effect of pure recycled mortar aggregate moisture content on concrete performance, which has a particular guiding significance for the application of low-quality recycled aggregate in concrete.P·O 42.5 Portland cement and fly ash were used as binders. The chemical composition was tested by XRF and is shown in Natural stone and recycled concrete with sizes of 5 to 16.5 mm were both selected as natural coarse aggregate (NA) and recycled coarse aggregate (RA), respectively. The recycled aggregate was obtained from the crushed C30 concrete by a hummer crusher. The natural appearance of two coarse aggregates is presented in The slump of recycled concrete was tested according to standard GB/T 50080 (test method for the performance of ordinary concrete mixtures) . The comm0. Then the concrete specimen was put into the water, keeping the distance between the bottom surface to the liquid level of 2 ± 1 mm. The mass tm of the specimen was recorded at the corresponding time point , and the water absorption per unit area of the concrete was calculated as follows:I is the water adsorption capacity per unit area in mm, tm is the mass of the test block at different times in g, A is the contact area between the test block and water, and d is the density of water, taken as 1000 g/mm3.The water adsorption test was carried out according to ASTM C1585 . The tesThe electric flux test was followed by the standard method for the long-term performance and durability of ordinary concrete . The cylThe rapid chloride ion migration coefficient was determined according to the standard for test methods of long-term performance and durability of ordinary concrete . A Φ100 A Dhv-1000 digital microhardness tester was used to test the microhardness changes in recycled concrete in the multiple interfacial transition zone (ITZ). The concrete slices cured for 28 d, with a thickness of 10 mm, were polished with 400, 800, 1000, and 2000 mesh sandpaper and vacuum dried at 60 °C to constant weight. The test load was 0.5 kN. The indenter was pressed into the surface of the test block and unloaded automatically after holding for 10 s. The prismatic indentation under a 400× microscope and the measurement of its diagonal length are shown in X-ray diffraction (XRD) was used to analyze the phase composition of the concrete interface; the cement mortar around the aggregate was scraped from tested concrete samples, as shown in After curing for 28 d, recycled concrete specimens were cut into cubes of 40 mm × 40 mm × 40 mm for porosity test using the nuclear magnetic resonance method. Small samples with aggregate and concrete matrix were prepared, cleaned in an ultrasonic cleaner for 5 min, and dried in a 45 °C vacuum-drying oven for 24 h. The micromorphology of the recycled concrete matrix and the interfacial area is observed by a GeminiSEM500 Schottky field emission scanning electron microscope produced by Carl Zeiss, Jena, Germany.The proportion of recycled concrete was mainly obtained through a trial mix and further optimized based on previous research results. Recycled aggregate concrete was prepared with aggregates with different moisture contents. The moisture content of the saturated surface of dry (SSD) recycled aggregate was 100%, and the moisture content of recycled aggregate was controlled by spray pot prewetting and drying to be 50%, 55%, 60%, 65%, 75%, or 100%, respectively. Air-dry recycled aggregate with a moisture of 25% was the control group. Seven groups of recycled concrete with different moisture contents were prepared and denoted as AD, W50, W55, W60, W65, W75, and W100. The mix proportion details are listed in According to the research method of aggregate characteristics , the morThe internal pore size distribution and cumulative porosity of natural aggregate and recycled aggregate are shown in The workability of concrete was sensitively affected by the free water in the fresh mixture. Since the water absorption of RA was higher than NA, more water was absorbed in wetting the RA particles during the mixing process, causing the decline of the real W/B ratio and an adverse effect on workability. So, with the prewetting degree increase in RA, the water absorption effect was weak; even the water in the aggregate was released into the mixture to improve the workability when the moisture content was exceeded. Relevant studies also showed that the slump of recycled concrete was the smallest when dry recycled aggregate was used, while it increased significantly when the recycled aggregate was saturated surface dry ,49,50. SThe compressive strengths of recycled concrete at 7 d and 28 d with different prewetting aggregates are presented in From the results, the compressive strength of recycled concrete performed similarly at 7 d and 28 d, but the strength increments of prewetting aggregates were higher after 7 d. Since the recycled aggregate surface was porose and rough, it was supposed that if the moisture in aggregate was low, part of the mixed water was absorbed to form a water layer on the particle surface and reduced the real W/B so that the strength was increased. However, with the moisture of the aggregate raised, the water absorption effect was reduced, even the water was released from the aggregate into the matrix, causing a loose and weakened structure, and the strength was decreased. On the other hand, the absorbed water in the aggregate supports the internal curing to form more hydration products in the long term, so the strength increases more after an early age. Poon’s study found that the compressive strength of recycled concrete was highest when the recycled aggregate was in the dry state , while BThe main reason was that the effective water–cement ratio in the interfacial transition zone (ITZ) was adjusted by recycled aggregates of various moisture. When the water content was lower than 65%, mixed water was absorbed into aggregates, and the ITZ structure was compact and hard for water transport. However, if the moisture was exceeded, more water was released into ITZ, increasing the porosity and deteriorating the compactness so that the water adsorption was increased again.−4 g/(cm2·s1/2) and 6.04 × 10−4 g/(cm2·s1/2), respectively. With the water content of prewetting aggregate increased, the initial and secondary water adsorption coefficients were reduced by 2.37–5.73% and 6.13–14.7%, respectively, when the moisture content was 50–65%, then increased by about 9.98% and 6.95% to 75%.The water adsorption coefficient of recycled concrete was also calculated and shown in To further investigate the change in the pore structure of recycled concrete with a different aggregate prewetting degree, the pore size distribution was measured by NMR, and the results are in −12 m2/s, which was lower by about 10% than that of AD. Once the moisture reached 100%, the diffusion coefficient increased to 38.56 × 10−12 m2/s, which was 10.3% higher than in AD. Zhao et al. [Chloride penetration is the main factor causing steel corrosion in concrete. The effect of aggregate moisture on chloride penetration was evaluated by chloride ion diffusion coefficient, and o et al.  also proMicrohardness can be used to quantitatively analyze the micromechanical properties and width of ITZ of recycled concrete. The microhardness around ITZ of recycled concrete with natural aggregate (NA-NM) and recycled aggregate (RA-NM) was comparatively studied and shown in In 2 in ITZ. The diffraction peaks of CaCO3 appeared at 29.4°, 39.4°, and 43.15°, which might be caused by carbonization. The diffraction peaks are marked in The XRD patterns from ITZ of recycled concrete with different prewetting aggregates are presented in The morphology of ITZ in recycled concrete was observed by scanning electron microscopy (SEM) and presented in The moisture migration of recycled aggregates with different prewetting degrees followed the different laws at the early mixing stage . When thHowever, when using saturated dry recycled aggregate, the water stored in the aggregate was released into the slurry under the action of centrifugal force, and the effective water–cement ratio of the interfacial transition zone and matrix increased. The high water–cement ratio at the interface led to an increase in the width of the ITZ and a decrease in microhardness and compressive strength. At the same time, the internal porosity of the recycled aggregate concrete with high moisture content was larger, and it was much higher than in the groups with slow and appropriate levels of prewetting, reaching 7.01%. The water absorption rate of concrete capillary water increased, and external ions were more likely to invade the interior of concrete and the chloride ion erosion resistance of recycled concrete.(1)Recycled aggregate made from crushed concrete had a rough surface, round particle shape, and higher porosity than natural aggregate. The water absorption and crushing index were 25 times and 2.5 times higher than those of natural aggregate;(2)With the prewetted degree continuously increasing from 0% to 100%, the slump of concrete was enlarged by 500%, while the strength was higher than the plain group at 50–65% and reached the maximum of 40.5 MPa. The appropriate moisture content of recycled aggregate would balance the water absorption in concrete at an early age, and more water would be released into the matrix to increase the real W/B ratio if the prewetted degree was too high;(3)The permeability of recycled concrete was also first decreased and then highly increased with the prewetted degree of aggregate increasing from 0% to 100%, and was optimal when aggregate was prewetted to 50–55%. The internal curing effect of wet aggregate declined the porosity by 0.77–6.30% and reduced the fraction of pores larger than 50 nm. When the moisture increased further, the porosity increased significantly;(4)The microhardness demonstrated that the width of the ITZ of recycled aggregate was larger than natural aggregate. However, with the prewetted degree of 50–60%, the width decreased to 90–100 μm, and the microhardness in ITZ ranged at 42.7–82.7, which was even higher than that of natural aggregate. The morphology also proved that with the prewetted degree of 50–60%, the ITZ was more compact with fewer cracks than another status;(5)Prewetted degree influenced the driving force of water absorption at an early age and the internal curing efficiency. At an appropriate prewetted degree, the water absorption was mitigated, thinner water film formed at the aggregate surface, which caused a compact microstructure formation, and the water in the aggregate migrated gently to promote the hydration by internal curing effect. Exceeded water might rapidly release into the matrix, increasing the porosity and causing a loose ITZ, which was weak for strength and impermeability.The physical performance of recycled aggregate was less than that of natural stone. To improve the properties of recycled concrete, the aggregate was prewetted to various degrees, and the results proved that the strength, impermeability, and ITZ properties were all improved at appropriate prewetted degrees. Below are some conclusions:


Textile-reinforced concrete (TRC) is a cement-based composite material that uses textile as a reinforcement material. The weft-direction fiber bundles in the traditional orthogonally arranged warp–weft textile hardly bear force, and its bonding strength with the weft fiber bundle is not ideal. Under the action of force, a small included angle between the stressed fiber bundle and the stressed direction can effectively increase the anchoring effect of their fibers in the matrix, resulting in higher bonding and reinforcement efficiency. To improve the utilization rate of fibers and the bonding strength between the textile and the concrete matrix, an arrangement along the diagonal of the grids was proposed in this paper. The flexural properties of basalt TRC plates with orthogonal grids (OG-BTRC) and plates with nonorthogonal grids (NOG-BTRC) with different grid angles and grid sizes with different laying methods, namely, a side layout (SL) and diagonal layout (DL), were studied through four-point bending tests. A comparative analysis was carried out with an ABAQUS simulation and the test results. The results showed that with a decrease in the grid angle, the BTRC specimens gradually showed a failure mode of multiple cracks, and most of the cracks appeared in the pure bending area; as the grid angle decreased, the BTRC specimens exhibited excellent flexural bearing capacity, good ductility, and high toughness. The total number of cracks on the specimen increased when it failed, while the spacing of the cracks decreased, and the fracture morphology appeared as fine and uniform features. The toughness of the specimen with a small grid angle using the DL laying method was greater than that using the SL laying method. The software simulation value matched the test data well, which proved that the test result was reliable. Textile-reinforced concrete (TRC) has been studied for decades as a new building material . HoweverIn the process of concrete cracking, cracks extend from the edge to the inside. A certain angle exists between the warp–weft textile in the cracked area and the crack, which is not the optimal arrangement. Mobasher et al. showed that at a very small orientation of 6°, the composite exhibited higher tensile-load-carrying capacity than a composite tested in the fiber orientation, that is, at 0° . TherefoTo ensure the strength of the composite material, the concrete matrix mix ratio was adjusted.2, Al2O3, CaO, FeO, Fe2O3, and TiO2. The filament surface is easily wetted and exhibits high alkaline resistance. Therefore, fiber roving is suitable for cement-based composite applications.In the experiment, continuous basalt fiber, a new high-performance inorganic fiber material made of basalt ore after high-temperature melting and drawing, was selected as the fiber material. Its main components are SiOThe grid angles were divided into four: 30°, 45°, 60°, and 90°. The grid sizes were divided into two: 20 mm × 20 mm and 40 mm × 40 mm. To ensure structural integrity, the textiles were impregnated with a special binder mixed with epoxy resin, curing agent, and absolute ethanol, wherein the volume ratio of epoxy resin to curing agent was 5:1. The epoxy resin penetrated into the fiber bundle, and after the epoxy resin and the curing agent were fully reacted, the synergistic force capacity of the textile and the concrete matrix could be effectively improved. The mechanical properties of the impregnated fiber bundles are shown in In order to reduce the influence of an uneven distribution of concrete strength, a large size of 800 mm × 400 mm × 20 mm thin-plate specimens was used in this experiment, as shown in The prepared specimens were placed at room temperature for 24 h and then removed from the mold. Next, the specimens were cured in a standard curing box for 28 days and then taken out. The cured 800 mm × 400 mm × 20 mm thin-plate specimens were processed and divided into 400 mm × 100 mm × 20 mm sections required for the four-point bending tests, as shown in The loading method of the four-point bending test of the thin plate is shown in The specification points out that the load F and the mid-span deflection ω are related to the size of the bending specimen. To better compare the bending performance of different specimens, the test results were expressed in the form of bending stress at midspan deflection curves.σ denotes the bending stress, F denotes the bending load, l denotes the span of the specimen, b denotes the width of the specimen, and h denotes the thickness of the specimen.The calculation formula of bending stress is shown in the following formula :σ=Flbh2Toughness, as an important parameter used to characterize the properties of fiber-reinforced cement-based composites, is used to describe the ability of composites to absorb energy during load failure. With the improvement of the toughness of the composite material, its various mechanical properties will be greatly enhanced. To describe the flexural resistance of the material in the four-point bending test, the toughness was compared using the calculation formula in the specification ASTM/C 1609, which is as follows :UT=∫Pdf=The BTRC specimens had three failure modes in the test: (1) tensile failure caused by the breaking of weft fiber bundles in the textile; (2) debonding failure caused by slippage between the textile and the concrete matrix; (3) shear failure of the composite material along the oblique section. The specimens with a grid size of 20 mm × 20 mm and the SL laying method mostly suffered tensile failure due to breaking of the weft fiber bundles; most of the specimens with a grid size of 20 mm × 20 mm and the DL laying method suffered debonding failure; and the specimens with a grid size of 40 mm × 40 mm all suffered tensile failure due to breaking of the weft fiber bundles. When statistical test data were obtained, the maximum and minimum values in the data were discarded, and the valid data within the interval were taken as the reference standard.In Through the comparison of The graph and data from Concrete is a brittle material, the failure process of PC specimens is short, and no obvious warning is given before a failure: this is known as a typical brittle failure. Only one crack appeared at the time of failure and continued to develop to the upper part of the specimen as the load increased, until the specimen was finally destroyed; the 40 mm × 40 mm basalt textile had a poor effect on enhancing the flexural performance of concrete, and only one wide crack appeared. As the load increased, the crack width increased continuously, and damage occurred as the fiber bundles between the cracks were pulled off. The concrete specimens embedded with 20 mm × 20 mm basalt textile showed obvious strain-hardening behavior, and the failure mode changed from brittle failure to ductile failure. A main crack was generated from bottom to top. When the crack reached the textile layer, it stopped extending upward and continued to generate fine microcracks around the main crack. When the intermediate textile slipped with the concrete matrix, the crack quickly extended upward from the middle layer until it was damaged. When DL-NOG45-BTRC20 failed, a crack first occurred near one of the loading points and stopped extending when it developed to the middle layer. At that time, a second crack occurred near the other loading point as the load increased continuously. As the second crack reached the middle layer, the previous crack continued to extend upwards, damaging the concrete. At that time, two cracks occurred in the specimen, one of which ran through the cross-section. DL-NOG30-BTRC20 had a large deformation when it was greatly deformed with the appearance of two to four cracks. First, two main cracks were generated near the two loading points, which gradually cracked from the bottom to the top, but they stopped when they reached the middle layer, and then secondary cracks appeared in the pure bending section, that is, between the two main cracks. With the increase in the number of secondary cracks, the bearing capacity of the specimen also gradually weakened, and the two main cracks penetrated the middle layer upwards, damaging the material. The textile played a good role in constraining the development of cracks in the concrete matrix, as shown in This paper used ABAQUS finite element software to run a simulation and verify the accuracy of the tests.First of all, during the period of creating parts, 3D, deformable, solid, and extrusion were chosen for the concrete part; 3D, deformable, wire, and extrusion were chosen for the fiber part; and 3D, analytical rigid, and extruded shell were chosen for the support part. Material properties were then given. For the concrete part, density, elastic, concrete damaged plasticity and concrete tension damage were selected. For the fiber part, density, elastic and plastic were selected. A solid, homogeneous section was chosen for the concrete and a truss was chosen for the fiber. Next, the assembly process was performed, as shown in The running results are shown in (1)As the grid angle decreased, the BTRC specimen exhibited excellent flexural bearing capacity, good ductility, and high toughness, and the total number of cracks in the pure bending section of the specimen increased, the crack spacing decreased, and the crack morphology appeared as fine and uniform features.(2)The toughness of the specimen with a small grid angle and a DL laying method was greater than that with a SL laying method.(3)As the grid size decreased, the ultimate bending stress and ultimate deflection of the specimen increased greatly. The change in grid size hardly affected the cracking stress and cracking deflection of the specimen.(4)The simulation results verified the reinforcing effect of the textile on concrete and the retarding effect on cracks in the tests. The simulation value obtained by the finite element software had a high degree of agreement with the test data results. Thus, the four-point bending test results were reliable.In this paper, a new textile laying method and grid angles were studied. Four-point bending tests of BTRC plates with different grid angles, laying methods, and grid sizes were used. All data on ultimate bending strength and deformation capacity were analyzed. Different types of cracking modes were analyzed, and finite element software was used to verify the reliability of the test data. The conclusions drawn are as follows:


Clostridioides difficile infection, especially among older adults.More than 80% of antibiotics are prescribed in the outpatient setting, of which 30% are inappropriate. The National Action Plan for Combating Antimicrobial Resistance called for a 50% decrease in outpatient antibiotic use by 2020. Inappropriate antibiotics are associated with adverse reactions and Before and after study.We performed a quality improvement initiative at the University of Colorado Seniors Clinic. Providers received education on antibiotic guidelines, electronic antibiotic order sets were introduced with standardized stop dates. Antibiotic use data were collected for 6 months before and 6 months after the intervention, from December to May to avoid seasonal variation. Descriptive statistics and linear mixed-effects regression models were used for this comparison.P = .0003), pharyngitis , and otitis .Total antibiotic prescriptions for acute respiratory conditions decreased from 137 prescriptions before the intervention  to 112 prescriptions after the intervention , driven primarily by decreases in antibiotic prescriptions for pneumonia, sinusitis, and bronchitis. Prescriptions for broad-spectrum antibiotics declined following the intervention including decreases in levofloxacin from 12 (9%) to 3 (3%) and amoxicillin-clavulanate from 15 (12%) to 7 (7%). We detected significant reductions in prescribed antibiotic durations (days) after the intervention for sinusitis (estimate, −2.0; 95% CI, −3.1 to −1.0; Low-cost interventions were initially successful in changing patterns of antibiotic use and decreasing overall antibiotic prescribing among older patients in the outpatient setting. Long-term follow-up studies are needed to determine the sustainability and clinical impact of these interventions. The availability of limited antibiotic options for resistant organisms poses a threat particularly to vulnerable populations including older adults and immunocompromised patients. Although antibiotic stewardship tends to focus on the hospital setting, outpatient antimicrobial use contributes to >80% of prescribed antibiotics, and 30% of prescribed outpatient antibiotics are considered inappropriate. The majority of these are for antibiotic prescriptions for upper respiratory conditions. Prior large-scale studies have repeatedly demonstrated that antibiotics are overprescribed for outpatient acute respiratory conditions, and the rate of inappropriate prescriptions ranges from 35% to 76% based on the specific condition.Rising antimicrobial resistance is a global public health crisis, resulting in 2.8 million infections and 35,900 deaths yearly.Clostridiodes difficile infection. According to the US Centers for Disease Control and Prevention (CDC), there are 223,900 cases of C. difficile infection and >12,800 deaths yearly. Older adults are at higher risk of adverse effects and complications associated with antibiotic prescriptions; however, they may also receive prescriptions at a higher rate due to increased concern for severe infections or nonspecific symptoms. In a large cohort of low-risk elderly patients, 46% of patients with nonbacterial acute upper respiratory infection received an antibiotic prescription.Not only do inappropriate antibiotic prescriptions contribute to an increase in antimicrobial resistance, but antibiotics are also associated with serious adverse effects such as drug–drug interactions, allergic reactions, neurologic or psychiatric effects, and  The CDC has formulated guidance for antimicrobial stewardship in the outpatient setting, but implementing those guidelines and changing patterns of antibiotic use among providers is a challenge. The most effective interventions have used a combination of strategies, incorporating technology (electronic prescribing decision support), personnel support , organization , and patient education .Acknowledging the key role that outpatient antibiotic use plays in fueling antimicrobial resistance, the US National Action Plan called for a decrease in outpatient antimicrobial use by 50% by 2020.The goals of this study were to implement and evaluate initial effects of multifaceted low-cost interventions to decrease antibiotic use, and we focused on prescriptions within a geriatric clinic. We hypothesized that there would be inappropriate antibiotic selection and duration for common upper respiratory conditions especially bronchitis and sinusitis and that our intervention could decrease duration of prescribed antibiotics and increase prescription concordance with guidelines.We performed a quality improvement initiative at the University of Colorado Seniors Clinic to decrease antibiotic use in acute respiratory conditions. The intervention was targeted toward improving clinician knowledge and providing tools for clinicians to provide nonantibiotic recommendations to patients presenting with acute respiratory symptoms. This protocol was submitted to the Colorado Multiple Institutional Review Board, which did not consider it to be human subject research.To obtain preintervention data, we collected antibiotic type, duration, and indication for antibiotic prescriptions for acute respiratory tract conditions from December 1, 2017, to May 31, 2018. Data were derived through a newly developed electronic heath record report, incorporating diagnosis codes and prescription data on dose and duration. This report was validated over multiple months by a team of Epic software specialists , clinical data managers, and infectious disease physicians. Acute respiratory tract infections included acute sinusitis, acute pharyngitis, acute otitis media, acute bronchitis, pneumonia, and acute exacerbation of chronic obstructive pulmonary disease (COPD). (Supplementary Images 2 and 3). Finally, in January 2019, we rolled out viral prescription pads, which provided instructions and recommendations for symptomatic relief for a viral syndrome (Supplementary Image 1). Comparison intervention data on antimicrobial prescriptions, indication, and duration were collected from December 1, 2018, to May 31, 2019, to avoid seasonal variation in antibiotic use.The interventions performed included 4 components and was introduced in June 2018 in a stepwise design. First, an infectious disease physician (L.C.) attended a meeting with the clinic faculty to provide in-person education on antibiotic guidelines. One geriatric physician (S.C.) and the geriatric pharmacist (D.F.) were coinvestigators on this project and met at regular intervals with the infectious disease faculty throughout the project. The geriatric pharmacist was integrated in the clinic and was available for antibiotic-related questions during clinic hours. Second, in July 2018, we implemented electronic antibiotic order sets for common ambulatory infectious syndromes that were prepopulated with first- and second-line antibiotic choices, indications, and durations, and instructed providers on their availability and usage. Third, beginning in November 2018, patient education posters were displayed in the clinic waiting areasP values are reported. The duration of antibiotic was set to 5 for missing values for azithromycin, which were part of composite prescription orders. Number of antibiotic prescriptions for individual providers was calculated for pre- and postintervention periods. Significance was defined as P < .05 and all statistical analyses were conducted in SAS version 9.4 software .Antibiotic use data before and following all interventions were obtained for analysis. Antibiotic data after individual intervention were not compared because there was a delay in validating our database. Frequency and percent were calculated for categorical variables by indications for pre- and postintervention time points. Median durations and interquartile ranges (IQRs) were calculated for antibiotic use overall and for respiratory indications. Antibiotic use before and after the intervention was compared using linear mixed regression models with provider as a random effect. Estimates, 95% confidence intervals, and Prior to the intervention, 362 total antibiotic prescriptions for 263 patients were given during 8,557 clinic visits, accounting for 42.3 antibiotic prescriptions per 1,000 clinic visits. Following the intervention, 324 antibiotic prescriptions were given during 8,442 clinic visits accounting for 38.3 prescriptions per 1,000 clinic visits, a decrease of 9.6%. Patients were similar in age and sex in the pre- and postintervention periods   Table . For sin1) Table . Followi1) Table . The timLastly, we explored whether the change in prescriptions was driven by individual prescribers. Of the 362 antibiotic prescriptions before the intervention, 266 (72%) were given by 4 providers Fig. . Followi who reported a decrease of 17%. Another recent large study from the Veterans’ Affairs health system showed an overall annual reduction of 3.9% from 2011–2018 across 1,200 outpatient clinics.In this pilot-phase quality improvement intervention, we first demonstrated the prevalence and types of inappropriate antibiotic prescribing in one of our clinics. We were able to accurately quantify the outpatient antibiotic use with the help of our newly created electronic report. By focusing on specific aspects of antibiotic prescribing, we were then able to decrease the use of broad-spectrum antibiotics as well as total antibiotic use  for certain acute respiratory conditions through a multistep intervention. Using a low-cost, less resource-intense approach, we were able to demonstrate a modest decrease in antibiotic use (10%), which is similar to that of a prior study by March-Lopez et al, and evaluating institution and clinic-level data has been challenging. Here, we were able to utilize report-building tools in the electronic health record system (Epic software) to track all antibiotic prescriptions generated in the outpatient setting. This allowed us to measure the impact of our intervention on the prescription, indication, and duration of antibiotics.One of the biggest challenges in implementing outpatient antimicrobial stewardship programs is the capability to appropriately track data of outpatient antibiotic use. Most prior studies have used large administrative claims database, Multifaceted antimicrobial stewardship interventions have shown to be successful in decreasing antibiotic consumption and improving overall antibiotic use. We implemented multiple low-cost interventions including an interactive session with providers, use of posters, and antibiotic order panels in the electronic record system. A flexible approach that can be tailored to individual clinic and practice settings has a better chance of being successful.Next, although antibiotic stewardship programs are most active in the inpatient setting, the most effective type of intervention for decreasing outpatient prescriptions is not known. Multiple different approaches have been tried to improve antibiotic prescribing including educational approaches, behavioral approaches, and technological support. The types of prescribing errors differed between infections. For sinusitis, lack of an indication for antibiotics, and excessive duration of antibiotics were common errors. Excessive antibiotic duration was noted in ∼50% of sinusitis patients. In other studies, the highest rates of unnecessary prescribing have been noted for acute bronchitis, acute sinusitis, and viral upper respiratory infections, where azithromycin, fluoroquinolones, and amoxicillin-clavulanate comprise a majority of the inappropriate antibiotic prescriptions. Consistent with these studies, azithromycin was the most prescribed antibiotic in our population as well. Before the intervention, the geriatric clinic had higher use of narrower-spectrum antibiotics, particularly doxycycline, compared to previous studies; however, the intervention was able to limit the duration of antibiotics for those already prescribed the appropriate agent.Our intervention was able to both decrease antibiotic prescriptions and better match the antibiotic and duration to guideline-based recommendations. In a prior study, we demonstrated that 81% of antibiotic prescriptions for acute sinusitis and 48% of antibiotic prescriptions for pharyngitis were inappropriate. However, with our intervention, nearly all providers had a decrease in the number of total prescriptions , caused some underestimation of antibiotic prescriptions if alternate methods of prescribing, for example written or telephone prescriptions were used. Furthermore, there may be a discrepancy between antibiotic prescription and actual antibiotic use. Additional limitations include our inability to evaluate change in prescriptions after each intervention and overlap between a couple of the interventions  with the postintervention data collection period.In summary, low-cost interventions can be successfully used to improve antibiotic prescriptions to decrease overall outpatient antibiotic use. Longer-term sustainability of these interventions and scalability to other clinics and infectious syndromes should be evaluated.


To improve the deformation performance of recycled concrete with tailings (TRC), its carbonization characteristics and deterioration mechanism with different polypropylene fiber content were analyzed macroscopically and microscopically. The results showed that the fiber had little effect on the compressive strength, which increased first and then decreased, with the optimum content being 0.6%. The splitting tensile strength first increased and then tended to be stable, with the optimum dosage ranging from 0.6% to 0.9%. The more the content, the higher the peak strain and the lower the elastic modulus. The rising section of its constitutive curve changed little, while the falling section became more gentle. Carbonization made the relative dynamic elastic modulus change small with a trend of first increasing and then decreasing, and the optimum content was 0.6–0.9%. When the fiber content was small, the influence on the carbonization depth did not remain significant, but when it was large, the depth increased obviously, and this critical content was about 0.6%. Microscopically, through nuclear-magnetic resonance (NMR) and scanning electron microscope (SEM) analysis, due to the strong tensioning effect of the fiber, when a small amount was added, the porosity and pore structure had not been significantly changed, so the impact on its resistance to carbonization was not obvious. However, after excessive addition, the interface transition zone (ITZ) between different materials became larger, resulting in a significant increase of its harmful cracks and a great impact on the anti-carbonization ability, with the optimal content being about 0.6%. This study provides a theoretical reference for the deformation performance improvement measure of TRC, which would be helpful for the rapid promotion and application of green concrete in engineering practice. With the expansion of urbanization and the three-dimensional development of urban space, the infrastructure of China has also undergone earth-shaking changes. By the end of 2018, the housing construction area and highway mileage were 8.8 and 8.75 times the corresponding area in 2000 . It is aFor fiber concrete, Meesala et al.  studied For tailing concrete, Filho et al.  replacedPresently, some scholars have made systematic research on RAC, tailing concrete, and fiber concrete separately, while studies on TRC with fiber are even rarer. Professor Wang Sheliang from Xi’an University of Architecture and Technology conducted a systematic macro and micro study on the carbonization ,21, sulfQinling ordinary Portland cement p.o.42.5) and the sand in Bahe River were used. The natural coarse aggregate (NCA) was artificially crushed stone, while the recycled coarse aggregate (RCA) was produced by a factory in Xi’an, with particle size of 5–20 mm and continuous grading. The IOT comes from a tailings pond in Shangluo, Shaanxi Province. The gradation curve, main components, and physical performance indicators of the above-mentioned materials were detailed in my last article [2.5 and tTo increase its fluidity, a polycarboxylic acid-based high-performance water reducer was used, which met the requirements of GB50119-2013 , and theBased on the previous research conclusions of our group on the mechanical properties and deformation properties of RAC ,26 and TThe main procedures and parameters of carbonation test was shown as The influence of fiber content before and after carbonization on the cube compressive strength of TRC is shown in According to As can be seen from nP is the relative dynamic elastic modulus of the i-th concrete test block after the corresponding carbonization age. nf (f0) is the fundamental frequency of the non-carbonized surface of the i-th test block after carbonization for the n-th (0-th) day (Hz). id is the carbonization depth of the i-th measuring point, and n is the total number of measuring points. In case of coarse aggregate blocking at the measuring point or cross coupling carbonization (edge carbonization) around the carbonization surface, the point with small fluctuation shall be selected around the corresponding point.The design and calculation of dynamic elastic modulus and carbonization depth were carried out in accordance with the requirements of the specification . To faciAs can be seen from From The microstructure of concrete directly affects its macro mechanical properties and durability . Therefo2 distribution spectrum was related to the pore size of porous materials. The larger the pore size, the greater the freedom degree of pore water and the longer the relaxation time. The Y-coordinate was the signal intensity, and its amplitude reflected the number of pores, the larger the amplitude, the greater the number of pores [2 relaxation curve was usually a multi-peak curve. The position of each peak corresponded to pore size, whose peak area was the definite integral of the T2 curve, and its value represented directly the pores’ number [The X-coordinate in the Tof pores . The T2 ’ number . The cha’ number .Based on the NMR results, the NMR signal quantity per unit volume was proportional to the porosity, and the values before and after carbonization could be obtained, as shown in Comparing In general, the fiber had positive and negative influences on the matrix structure, and the two worked together to produce the above-mentioned main mechanical and durability change characteristics, which had a greater impact on the tensile and deformation properties. However, when the content was large, its negative effect increased significantly. From the perspective of the text, the optimal dosage was 0.6%.(1)Polypropylene fiber had little effect on cube compressive strength and axial compressive strength, showing a trend of increasing first and then decreasing, with the best content of 0.6%. The splitting tensile strength increased obviously, increased first, and then tended to be stable, and the optimum content was 0.6–0.9%. The higher the content was, the greater the peak strain. The elastic modulus fluctuated slightly, the greater the content, the lower the elastic modulus. It can optimize the ductility of the prismatic test block and reduce the fluctuation of the falling section of the constitutive curve. The situation after carbonization was similar to that before carbonization, the position of certain peak points was approximately unchanged, and made their corresponding values fluctuate less.(2)Carbonization made the relative dynamic elastic modulus change less. As the fiber content increased, its value approximately increased first and then decreased, with a peak content of 0.6–0.9%. When the content was small, it had little effect on the carbonization depth, when it was large, the carbonization depth increased greatly and the carbonization resistance deteriorated seriously. The content in this critical state obtained approximately 0.6%.(3)Through NMR and SEM analysis, the fiber had a strong pulling effect, a small amount of addition can greatly improve its deformation ability, and had little effect on the pore diameter and porosity. However, after excessive addition, the contact area between different materials would increase. At the same time, the stress concentration phenomenon of the fiber after being stressed would also cause the harmful gaps in the concrete to increase, reducing the anti-carbonization ability, and the optimum mixing amount was approximately 0.6%.Through the analysis of the carbonization characteristics and deterioration mechanism of TRC with different carbonization cycles and fiber contents, the following conclusions can be drawn:2 corrosion is not degraded.Through macro and microanalysis, when the content of polypropylene fiber was 0.6%, its porosity and pore structure reached the optimum. At this time, TRC can not only obtain the best mechanical and deformation properties but also its resistance to CO


A Mach–Zehnder fiber optic sensor with high refractive index response sensitivity was developed. By fabricating a waist-enlarged bitaper structure on the interference arm of a single mode–multimode–single mode (SMS) Mach–Zehnder interferometer (MZI), the spectral contrast and response sensitivity were improved. Subsequently, the response sensitivity was further improved by etching the interference arm. When a beam of light was introduced into the sensor, due to the structural mismatch between the multimode fiber and the normal transmission light, the difference between the low-order mode and the high-order mode was generated in the fiber core and the fiber cladding. In the process of transmission in the sensing arm, due to the different refractive indices of the core and cladding, the optical path difference of the high-order mode and the low-order mode was different, which eventually generated interference fringes. The experimentally measured response sensitivity of SMS MZI in the range of 1.351 RIU to 1.402 RIU is 57.623 nm/RIU; the response sensitivity of a single mode–multimode–bitaper–multimode–single mode (SMBMS) MZI is 61.607 nm/RIU; and the response sensitivity of the etched SMBMS (ESMBMS) MZI is 287.65 nm/RIU. The response sensitivity of the new ESMBMS MZI is three times higher than that of the original SMS MZI. The sensor has the characteristics of compact structure, high sensitivity, easy manufacture, and a wide range of refractive index measurements, and can be used in food processing, pharmaceutical manufacturing and other fields. The refractive index is a commonly used process control index in food production, pharmaceutical development, and other fields. By measuring the refractive index of liquid substances, the composition of the substance can be identified, the concentration determined, and the degree of purity and quality judged. Traditional electronic sensors cannot work in harsh environments, such as high salinity and strong oxidation ,2. In reOptical fiber wavelength-dependent sensors are divided into various types according to their structure, such as the fiber Michelson , U-shapeSince the 1990s, the optical fiber MZI, used to measure the refractive index, began to develop rapidly as a new generation of sensors. In 1994, Liang  measure In order to further improve the response sensitivity of the sensor, many researchers explored methods to change the structure of the MZI sensing arm, such as adding a fiber taper structure. In 2019, Liao et al.  designedEtching the MZI sensing arm is also a commonly used method in improving the refractive index sensitivity. In 2011, Changping Tang  developeIn this paper, based on the principle of double-beam interference, three sensors were designed, fabricated, and compared. The first was a fiber sensor, based on single mode–multimode–single mode (SMS) MZI. The second specific structure was realized by melting a waist-enlarged bitaper in the middle of the sensing arm of the first sensor; the specific structure was single mode–multimode–bitaper–multimode–single mode (SMBMS). The third was realized by etching the sensing arm with hydrofluoric acid on the basis of the second sensing structure, which was referred to as ESMBMS for short. The principle of interference sensing, the fabrication method of the optical fiber cone structure, the analysis of the spectral mode, and the corrosion mechanism of the optical fiber by hydrofluoric acid were analyzed; experiments were designed to measure the sensitivity response of the refractive index of various sensors. Finally, a high-sensitivity refractive index sensor was obtained by making waist-enlarged bitaper and etching. For the convenience of comparison, we summarize the characteristics, advantages, and disadvantages of various sensing structures in The basic structure of the fiber MZI involved in this paper is SMS MZI, as shown in LPm0 and LPn0  are in the multimode fiber, the phase difference between them is:L is the length of the fiber and LP0m and LP0n. The equation for the effective refractive index is as follows:neff is the effective refractive index, n is the refractive index in the medium, s is the distance traveled by the light, and L is the length of the interference arm. Equation (2) shows that when the refractive index of the medium and L are constant, the mode with the higher order has a larger diffusion angle. That is, the effective refractive index of the high-order mode is greater than that of the low-order mode.The occurrence of the interference phenomenon depends on the optical path difference between the two beams. It can be seen from the structure that the core path and cladding path of the MZI sensing arm are of equal length. There is a direct relationship to the frequency spectrum of wavelengths, which is the effective refractive index difference between the different light wave modes. Assuming two different guided modes I is the output light intensity of the MZI, 1I and 2I are the light intensity of the guided mode LPm,0 and the light intensity of LPn0 in the interference core. According to Equation (3), the phase difference equation corresponding to the valley is as follows:The intensity of the output light can be expressed as:m is an integer, representing the interference order and Substituting Equation (1) into Equation (4), we obtain:L is constant, the shift amount of the interference valley wavelength changes with the change of the refractive index of the external liquid. Therefore, the refractive index of the sucrose solution is measured by monitoring the shift in the wavelength of the m-th valley of the MZI.According to Equations (4) and (5), Equation (6) is obtained:In order to enhance the sensitivity of the fiber MZI, the SMBMS MZI was developed on the basis of the SMS MZI, as shown in The following section focused on analyzing the response characteristics of the optical fiber waist-enlarged bitaper. The inverted taper was composed of a multimode fiber and an inverted taper fiber with a gradually enlarged diameter. The waist-enlarged bitaper part played the role of expanding the beam of the fundamental mode spot. The waist-enlarged bitaper directly affected the propagation response characteristics of the beam in it, as shown in ω(z) and the wavefront curvature radius R(z), used to describe the propagation response characteristics of Gaussian beams [The propagation response characteristics of Gaussian beams in tapered fibers are given by the spot size an beams .(7)ω2. In the sensing system, a fiber cleaver  was used to obtain a flat fiber end, and make a waist-enlarged bitaper based on commercial fusion splicers. Multimode optical fiber has a core diameter of 40 µm and a cladding diameter of 125 µm. By increasing the splicing time to 500 ms, and increasing the splicing strength to 155 unit, the waist-enlarged bitaper is obtained. Since the refractive index sensitivity response of the SMBMS type structure sensor was still very low, in order to further improve the refractive index sensitivity, the SMBMS type structure sensor was improved. As shown in When the sensing arm was etched, the diameter of the interference arm decreased, which increased the coupling degree between the cladding mode and the ambient refractive index. The change of the refractive index caused the change of the phase difference of the transmitted light in the fiber, and then the change of the refractive index was measured by measuring the change of the interference spectrum. In this experiment, the sensing arm was used to sense the change of refractive index, which was reflected on the spectrum, that is, the wave valley moved. By measuring the drift of the valley, the change in the refractive index was measured.2) material. Hydrofluoric acid dissolves silica mainly for the following two reasons: First, hydrofluoric acid solution contains fluoride ions, which combine with silicon ions in SiO2 to form complex ions. Second, the hydrogen ions in the hydrofluoric acid solution form water with the oxygen ions in the SiO2. The reaction equation can be expressed as follows:The etching solution often used in the optical fiber chemical etching method is a hydrofluoric acid solution. The cladding of optical fibers is generally made of silicon dioxide ξeff and different modes, based on OptiFiber. The wavelength ξ are 0.0199164 nm−1, 0.0300104 nm−1, and 0.0412538 nm−1. Therefore, the parameter Δneff calculated from Equation (15) are 0.002392458, 0.003604999, and 0.004955613. In other words, as the sensing arm is spliced with waist-enlarged bitaper and etched, higher-order modes are excited, affecting the optical path of transmitted light in the optical fiber core and cladding. Subsequently, the refractive index responses of the three sensors were measured experimentally.Considering the modal dispersion, we established the relationship between ΔnThe length of the sensing arm of the SMS MZI is about 20 mm. From In view of the low refractive index sensitivity of SMS MZI, an improvement was made on the basis of SMS MZI, by melting a waist-enlarged bitaper in the middle of the sensing arm. The photo of the waist-enlarged bitaper is shown in From Since the refractive index sensitivity of SMBMS MZI was still low, improvements were made on the basis of SMBMS MZI. The method used was to corrode the sensing arm of SMBMS MZI with hydrofluoric acid for 20 min. The waist-enlarged bitaper is shown in It can be seen from In this paper, a high-sensitivity MZI was designed and fabricated. The single mode fiber and the multimode fiber were directly spliced by a commercial fusion splicer to form a coupling point. The multimode fiber was in the middle of the sensing arm, and a waist-enlarged bitaper was fused in the middle of the sensing arm, used to realize beam adjustment. Finally, the cladding of the sensing arm was etched with hydrofluoric acid to reduce its diameter, which in turn achieved improved response sensitivity. Fourier transform analysis shows that both the waist-enlarged bitaper and erosion excite higher-order modes, resulting in a larger optical path difference for light transmitted in the optical fiber core and cladding. The refractive index sensitivity responses of these three sensors were experimentally investigated, and the refractive index sensitivity of SMS MZI is 57.623 nm/RIU, with a linearity of 0.9795; the refractive index sensitivity of SMBMS MZI is 61.607 nm/RIU, with a linearity of 0.9545; and the refractive index sensitivity of ESMBMS MZI is 287.65 nm/RIU, with a linearity of 0.9843. It is shown that ESMBMS MZI has a very high refractive index sensitivity and good linearity. As the new ESMBMS MZI, designed in this paper, possesses the advantages of high sensitivity, good linearity, low cost, and simple fabrication, it has a high practical value and good application prospects for future production.


Simple sensing protocols for the detection of illicit drugs are needed. Electrochemical sensing is especially attractive in this respect, as its cost together with the analytical accuracy aspires to replace still frequently used colorimetric tests. In this work, we have shown that the interfacial transfer of protonated heroin can be followed at the electrified water-1,2-dichloroethane interface. We have comprehensively studied the interfacial behavior of heroin alone and in the presence of its major and abundant cutting agents, caffeine and paracetamol. To maximally increase developed sensing protocol applicability we have designed and 3D printed a platform requiring only a few microliters of the aqueous and the organic phase. The proposed sensing platform was equipped with a cavity hosting a short section of Ag/AgCl electrode, up to 20 µL of the aqueous phase and the end of the micropipette tip being used as a casing of a fused silica capillary having 25 µm as the internal pore diameter. The volume of the organic phase was equal to around 5 µL and was present inside the micropipette tip. We have shown that under optimized conditions heroin can be detected in the presence of caffeine and paracetamol existing in a sample with 10,000 times excess over the analyte of interest. The calculated limit of detection equal to 1.3 µM, linear dynamic range spanning to at least 50 µM, good reproducibility, and very low volume of needed sample is fully in line with forensic demands. In Europe, although very popular, make a smaller contribution to the total illicit drugs market. Heroin is the best known and most common opiate. Only in 2019, heroin trafficking was confirmed in 99 countries. In 2019 the amount of seized heroin in Europe was record-breaking and has tripled since 2016. For the given year, heroin represented 27% of the total number of drugs sold worldwide.As many as 62 million people were using opioids for non-medical purposes in 2019-estimation says2. In a pure form it appears as a white powder3, which is rare for the street samples5. The color of the illegal heroin samples vary depending on their contamination originating from the production process, added cutting agents, and ranges from white, through cream, beige, to medium and dark brown 6. In the European Union, heroin purity at the retail level is estimated within the range from 18 to 30% occasionally being elevated7. The street sample filling is mainly assured with cutting agents which are commonly added to many illicit drugs and make an additional burden to the sensing device's functionality11. The main cutting agents of heroin are paracetamol and/or caffeine, which were found in 90% (!) of heroin street samples in Europe. According to an elegant review by Broséus et al. the presence of these adulterants in seized heroin powders was confirmed in 128 countries12. Accordingly, there is an obvious need for a sensing methodology development that can detect heroin directly from street samples. At the same time, illegal sample testing is expected to be selective, simple in terms of manufacturing, portable, easy in operation, and cheap. In a view of heroin street samples composition, the sensing device providing linear dynamic range within µM range will suffice. These requirements are within the capability of electrochemical detection. This broadly defined methodology appears to be an excellent choice for the rapid and highly sensitive determination of narcotic substances13. Drugs such as cocaine15, fentanyl17, or tetrahydrocannabinol19 can be directly detected by following their consecutive redox reactions or indirectly after smart electrode surface engineering20. A few electroanalytical works focused on the analyte of interest exist in the literature. Rodriguez et al. studied direct oxidation of heroin at carbon paste electrodes providing similar output as compared with the high-performance liquid chromatography21. Garrido et al. investigated the voltammetric oxidation of heroin and its metabolites on glassy carbon electrodes and proposed the mechanism of its oxidation22. The strategy of electrochemically detecting heroin in street samples was comprehensively studied by Florea et al. with graphite screen-printed electrode with focus given to two pH values, this is 7.0 and 12.023.Heroin (systematic name (IUPAC): -7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol acetate) is also known as diacetylmorphine and diamorphine. It can be synthesized by acetylation of morphine or extracted from poppy seeds where it occurs naturally. Heroin is classified as a drug with the highest addiction potentiala (7.6)24, and hence, positively charged. As such, heroin may undergo electrochemically controlled interfacial ion transfer reaction across the electrified liquid–liquid interface (eLLI) which was confirmed in a work published by Gulaboski et al. 25. Electrochemical studies at the eLLI not only provide direct insight into molecular partitioning and pharmacochemical parameters but also can be directly employed in the detection based on the simple interfacial ion transfer reactions (sensing not limited to oxidation/reduction reactions)26. In a view of illicit drugs sensing, eLLI was successfully applied to detect and fully understand the interfacial behavior of cocaine together with its numerous cutting agents27. Also, we have shown that ionic currents originating from the ephedrine  transfer across eLLI suffice for its quantification in urine29. Reports describing the interfacial behavior of other regulated molecules such as gamma-aminobutyric acid30, and a few opioids and amphetamine-like drugs25 are also available in the literature.With tertiary amine functionality present within heroin structure, this illicit drug may be protonated at pH < pK31. We have proposed a very straightforward sensing platform that is derived from a 3D printed support with a cavity hosting a few microliters of the aqueous phase  and a single pore microcapillary being filled with a few µL of the organic phase. eLLI miniaturization has a few crucial benefits over traditional macroscopic counterparts: (i) minimal consumption of the chemicals; (ii) lower capacitive currents; (iii) higher mass transfer to eLLI and (iv) improved stability of the soft junction governed by the pre-adjusted microscopic aperture surface wettability32. Approaches used to miniaturize eLLI can be based on metal wire templated glass capillary33, pulled glass capillaries34, patterned glass slides35, laser-ablated polymeric films36, micro-punched films37, apertures fabricated in the SiN chips40, or simply are based on porous materials such as zeolites, mesoporous silica of fiberglass membranes44. Miniaturization protocols are also frequently applied during sample preparation aiming at e.g. analyte extraction from the investigated matrix45. In this work, the eLLI was miniaturized with the fused silica microcapillary hosted in a micropipette tip46. Heroin, caffeine and paracetamol formulations (model street samples) were subjected to analysis in the constructed sensing platforms using only a few µL of each phase.Our work is focused on understanding the heroin behavior at the eLLI. The electroanalytical signals originating from the charged heroin species transfer across the polarized soft junction were used to plot ionic partition diagrams , derive physicochemical, and analytical descriptors . Heroin sensing was performed in the presence of its major cutting agents: caffeine and paracetamol. As reported by Kaliszczak et al. caffeine is active at the electrified water-1,2-dichloroethane interface, and hence, may potentially interfere during heroine detection−1, Cayman Chemical Company); paracetamol ; caffeine ; tetrapropylammonium chloride , sodium chloride ; 1,2 – dichloroethane ; were all used as received. As the organic phase electrolyte, we have used a salt synthesized from the potassium tetrakis(4-chlorophenyl) borate  and bis(triphenylphosphoranylidene)ammonium chloride . KTPBCl and BTPPACl were first separately dissolved in the 1:2 MeOH:H2O mixture and further added dropwise to each other. Resulting precipitate (BTPPATPBCl) was recrystallized from acetone. Next, the appropriate mass of crystals was further dissolved in 1,2 – dichloroethane to obtain 5 mM solution serving as the organic phase. The aqueous phase used to form ITIES was either 10 mM NaCl or 10 mM NaCl in a Britton–Robinson Buffer (BRB) buffer with a pH in the range from 2 to 11 (most often pH 2 or 5.5). The value of pH was adjusted with 1 M NaOH. BRB buffer was prepared from a stock solution of the buffer matrix being a mixture of boric acid (H3BO3), ortho phosphoric acid (H3PO4), acetic acid (CH3COOH) and sodium chloride (NaCl). The desired pH value for BRB was adjusted with a pH meter  using a polymer pH electrode .Heroin  supported with NOVA 1.11.1 software. The measuring system was studied with four electrode configuration. The macroscopic electrified liquid–liquid interface was polarized using two counter electrodes (Pt wires) placed in the aqueous and the organic phase. The potential drop across planar soft junction was measured between two Ag/AgCl electrodes each placed in the Luggin capillary present on the aqueous and the organic phase side of the liquid–liquid interface.The liquid–liquid interface formed at the end of the tip located within the 3D printed microliter volume aqueous phase droplet was polarized using two electrode configuration. The Ag/AgCl wire was protruding through the bottom of the droplet cavity whereas Ag/AgTPBCl was immersed inside the micropipette tip and remained in contact with the organic phase.Macroscopic liquid–liquid interface scheme:Microscopic liquid–liquid interface scheme:3D printed platforms were designed in the Thinkercad software and further exported as the .stl files. All section of the constructed device were printed with either Prusa Mini + or Prusa i3 MK3S . Before fabrication, the design was sliced in the Prusa Slicer software using following parameters: 0.15 mm speed; PLA filament; 20% filling; 215 °C as the temperature for the heating nozzle for the first layer and 210 °C for the remaining layers; the table temperature was 60 °C during entire printing process. The polylactic acid filament was from Fibrelogy. The silver wire protruding through the aperture located below the cavity dedicated for the droplet deposition was secured with the silicone sealant to avoid any possible aqueous phase leakage. Before application for sensing, the silver wire was contacted to 1 M HCl and the sufficient anodic potential was applied against pseudoreference electrode (second Ag wire) so that the AgCl layer was formed at its surface.47. First, the short section of the capillary having 25 µm as the pore internal diameter and hydrophobic pore interior was sliced with a ceramic knife (around 3–4 mm). Next, this section was inserted into the end of heat shrinkable micropipette tip dedicated for up to 20 µL volume. Bunsen burner was used to entrap the tip into shrined polymeric casing, whereas tweezers allowed the postiong of the capillary within the end of the tip so that only around 100 µm remained in contact with the tip. Again, we have used ceramic knife to remove the excess of the tubing. Microtip prepared in such manner was filled with the organic phase and was further inserted into the aqueous phase droplet using the 3D printed support.The fused silica microcapillary based supports for the electrified liquid–liquid interface were prepared according to protocol published recently in our groupa value (7.6)24 tertiary amine present within heroin structure is protonated and hence, exists in a cationic form. It can transfer across the eLLI when sufficient Galvani potential difference is applied and the resulting ionic currents can be probed with all techniques offered by the electroanalytical toolbox. Figure + (0.17)/Slope− (0.17) = 1), whereas the peak to peak separation is 73 mV for 15 µM heroin . Based on the obtained CVs we have plotted the calibration curves  for heroin was calculated using the equation:Below its pKgure + 0.7/Slope− gure + 0.7/Slope− 49  calculated using Eq.  is relatively hydrophobic and predominantly partitions to the organic phase. At pH > 5, the mechanisms of the interfacial charge transfer reactions changes. The existence of the neutral form of heroin in the organic phase facilitates the transfer of protons from the aqueous to the organic phase upon forward polarization . As the pH increases the fraction of the interfacially transferring charge originating from the simple heroin cation drops on account of facilitated transfer of protons.The best fit for the experimental points depicted in Fig. To evaluate the performance of the eLLI based sensing protocol, the interfacial behavior of heroin was studied in the presence of its major cutting agents at the macroscopic soft junction. Figure −1 .Figure see Fig. B,D,F whi46. The organic phase was always added to the microtip (volume ~ 5 µL) and the LLI was formed inside the aqueous phase droplet at the tip ingress  that will prevent the organic phase evaporation. This is further confirmed by the comparison of the electroanalytical output of the proposed methodology with the existing state-of-the-art summarized in Table The result of this verification study is summarized in Fig. In this work, we have studied the interfacial behaviour of heroin alone and in the presence of caffeine or/and paracetamol at the electrified liquid–liquid interface. Two latter compounds are the main cutting agents found in the vast majority of heroin street samples. Heroin undergoes the electrochemically controlled ion transfer across the water – 1,2-dichloroethane solutions interface within the available potential window. At optimized aqueous phase pH equal to 5.5 the cutting agents either affected the voltammetric signal originating from the heroin interfacial transfer nor the voltammetric detection sensitivity. To fully reveal the analytical potential of the developed procedure we have 3D printed the sensing platform hosting up to 20 µL of the aqueous phase and the end of the microtip  being used as the support of the polarizable soft junction. We have proved that the developed heroin sensing platforms fully meet forensic demands.Supplementary Figures.


To reveal the differences between the mechanical properties of solid waste coarse aggregate concrete and natural coarse aggregate concrete (NCAC) under equal strength, the basic mechanical properties of coarse aggregate concrete with seven different solid wastes  were tested, and the trends in failure morphology, elastic modulus, and the stress–strain full curves of the different solid waste coarse aggregate concretes were analyzed and compared with NCAC. Finally, the interfacial structure of the concrete was characterized by SEM. The results showed that C30 strength grade concrete was prepared with different solid waste coarse aggregates; however, the 28 d compressive strength, split tensile strength, axial compression strength, flexural strength, and elastic modulus of the concrete was 35.26–47.35, 2.13–3.35, 26.43–42.70, 2.83–3.94, and 17.3–31.2, respectively. The modulus of elasticity of the solid waste coarse aggregate concrete was smaller than the NCAC under equal strength, with a maximum difference of 45%. The peak compressive strain and ultimate compressive strain were larger than the NCAC, with a maximum difference of 43%. The crushing value of the solid waste coarse aggregate affected the splitting tensile strength, flexural strength, and modulus of elasticity of the concrete to a greater extent than the compressive strength. The transition zone at the concrete interface of the coarse aggregates with different solid wastes varied widely. The porous micro-pumping effect of the self-combusted gangue and self-combusted gangue vitrified reinforced the concrete interface transition zone, and the polished surface of sheet waste, uncombusted gangue, and recycled concrete aggregate surface adhesion weakened the interface transition zone; Finally, the uniaxial compressive stress–strain curve model for concrete with different solid waste coarse aggregates was established based on the Guo Zhenhai model. China is the largest developing country in the world, but the rapid development and industrialization has undermined the harmonious development of human beings and the environment. With various mining, energy, heavy industry, chemical industry, civil engineering, and other industries as representatives, more than 5 billion tons of solid waste are generated each year, accounting for more than 2 million hectares, and the total amount of solid waste accumulated over the years exceeds 60 billion tons ,2. The ma, εh, εb, and H, had obvious regularity with the increase in the replacement ratio. It was suggested to take the critical state as the final damage state of the intrinsic model to fully consider the ductility of the material distribution damage stage and to avoid the size effect of the local damage stage. Yun [In recent years, research enthusiasm for “solid waste” as aggregates of concrete has continuously improved at home and abroad. For example, YuxiangTang et al.  proposedage. Yun  et al. uage. Yun  that couage. Yun  et al. iage. Yun  studied age. Yun  studied age. Yun  studied age. Yun  studied age. Yun  studied age. Yun  studied age. Yun ,19 studiage. Yun  and Zhanage. Yun  studied age. Yun ,23,24 anage. Yun  carried age. Yun ,27 and Wage. Yun ,29 carriage. Yun ,34,35,36age. Yun . The traIn this paper, combined with the current ranking of the accumulated amount of solid waste in China, based on an analysis of the different physical and chemical properties of solid waste, natural coarse aggregate (NCA), such as limestone gravel, was taken as the baseline control group, and seven solid wastes were selected as follows: self-combusted coal gangue ceramicite (SCC), self-combusted coal gangue (SCG), unburned coal gangue (UCG), recycled concrete aggregate (RCA), iron waste rock (IWR), marble sheet waste (MSW), and granite sheet waste (GSW). They were all siliceous aggregates. The continuous-graded coarse aggregate, with a size of 5–20 mm, was prepared using the same process, which replaced 100% of the natural aggregates to prepare the C30 concrete, respectively, and the C30 concrete was prepared by completely replacing the NCA. Through the mechanical properties test and the microscopic characterization of 168 specimens with different sizes and eight ratios, the effects of the surface morphology and the crushing value of the solid waste coarse aggregate on the compressive strength, splitting tensile strength, flexural strength, axial compressive strength, elastic modulus, and compressive stress–strain curve of the solid waste coarse aggregate concrete were studied. The constitutive relationship between the microstructural characteristics and macroscopic behavior of the different solid waste coarse aggregate concretes was revealed, and the constitutive model of the concrete considering the characteristic parameters of the solid waste coarse aggregate was established, which provides theoretical guidance and technical support for the application of solid waste coarse aggregate concrete in engineering.Firstly, the raw solid waste was prepared into different sizes of single-graded coarse aggregate by jaw crushing → screening, and other preparation processes, and then graded according to “Recycled Coarse Aggregate for Concrete” (GB/T25177-2010) and, finally, coarse aggregates with a particle size of 5–20 mm with a continuous gradation was obtained, and the particle size and gradation of the eight different coarse aggregates were almost the same. The macro- and micromorphologies of the seven kinds of solid coarse aggregates are shown in It can clearly be seen from 0) and porosity (P0) that the coarse aggregates of the NCA, UCG, IWR, MSW, and GSW met the requirements of class I , the coarse aggregate of the RCA met the requirements of class II , and the coarse aggregate of the SCG met the requirements of class III .It can be seen from m) of the NCA, IWR, MSW, and GSW was less than 3%, which met the requirements of class I (≤3%). The Wm of the SCC and UCG was less than 5%, which met the requirements of class II (≤5%). The Wm of the SCG and RCA was less than 8%, which met the requirements of class III (≤8%).The water absorption  of the NCA, UCG, and IWR were less than 10%, which met the requirements of class I (≤10%). The Qa of the RCA, MSW, and GSW was less than 20%, which met the requirements of class II (≤20%). The Qa of the SCC and SCG was less than 30%, which met the requirements of class III (≤30%).In conclusion, the seven solid waste coarse aggregates selected in this experiment had different granular shapes, apparent densities, water absorption, crushing values, and mineral compositions, and they were significantly different from the NCA in the technical properties, but they still met the requirements of the different classes of coarse aggregates in GB/T 5177-2010.The binding materials were cement (P·O 42.5R), fly ash (F-II), and slag (S95), and the main technical properties and chemical constituents are shown in Natural aggregate concrete (NCAC) formulated with natural sand and stone was used as the reference group, and a total of eight concrete proportions with different coarse aggregates, mix slump of 30 to 50 mm, and strength grade of C30 was designed. There were three groups of cubic specimens with molding sizes of 100 × 100 × 100 mm, two groups of prismatic specimens with a size of 100 × 100 × 300 mm, and one group of prismatic specimens with a size of 100 × 100 × 400 mm, and a total of 18 specimens in each mixing ratio and 144 specimens with eight mix ratios. In order to test the accuracy of the prediction model, another four groups of 12 prismatic specimens with sizes of 100 × 100 × 300 mm and 12 cubic specimens with sizes of 100 × 100 × 100 mm were formed for a total of 168 specimens.According to “Specification for mix proportion design of ordinary concrete” (JGJ 55-2011) and “Technical specification for lightweight aggregate concrete” (JGJ 51-2002), the test mix proportion of the concrete was calculated and finally determined, as shown in All specimens were maintained in a standard curing room until the specified ages, and the mechanical tests were carried out in accordance with the relevant test methods in the “Standard for test methods of concrete physical and mechanical properties” (GB/T 50081-2019). Cubic specimens of 100 × 100 × 100 mm were used for tests on the compressive and splitting tensile strength, prismatic specimens of 100 × 100 × 300 mm were used for the axial compressive strength, elastic modulus, and stress–strain curve, and prismatic specimens of 100 × 100 × 400 mm were used for the flexural strength. The cubic and axial compression tests were carried out on the electro-hydraulic servo universal testing machine (1000 kN), using a displacement control loading system, and the loading rate was controlled at 0.01 mm/s. The dynamic data acquisition system, strain gauge, and extensometer were used to collect the test data in the stress–strain test of the concrete, and the complete stress–strain curve under compression was plotted. The splitting tensile and flexural tests were carried out on an electro-hydraulic servo universal testing machine (300 kN). The loading mode of the tests is shown in 3. After being pumped to the vacuum state, the surface was sprayed and placed under SEM. The surface morphology of the samples was observed by JSM-7500F in a cold field (accelerated voltage: 5 kV).A scanning electron microscope (SEM) was used on the above 28 day old specimens. After the cube compressive strength test, the interface between the cement paste and aggregate was selected from the fragments, and the observation surface of the samples was required to be as flat, small, and thin as possible, of which the maximum did not exceed 1 cmThe mechanical properties of the concrete with different coarse aggregates are shown in cu), splitting tensile strength (fts), axial compressive strength (fcp), flexural strength (ftm), and elastic modulus (E) of the concrete with solid waste coarse aggregates were taken as the average values of three specimens. It can be seen from cu and fcp of the concrete with seven kinds of coarse aggregates was IWRC > MSWC > GSWC > RCAC > NCAC > UCGC > SCCC > SCGC. The order of fts was NCAC > GSWC > IWRC > MSWC > SCGC > RCAC > UCAC > SCCC. The order of ftm was NCAC > IWRC > GSWC > MSWC > RCAC > SCGC > IWRC > UCGC. The axial compression ratio (fcp/fcu), tension–compression ratio (fts/fcu), and compression ratio (ftm/fcu) of the seven solid waste coarse aggregate concretes were 0.74–0.93, 0.062–0.091, and 0.079–0.108, respectively. It can be observed from 2 was formed by hydration and enriched on the surface of the attached slurry.The cubic compressive strength  is far less than that of strain gauge (10−6 mm) of ascending section. Third, due to the lack of data in the descending section, the dispersion was large. Therefore, the error of the descending section of the concrete stress–strain relationship curve is large. A lot of work still needs to be done on the parameters of the descending section in the future. However, as long as sufficient information is available, satisfactory results can be obtained through statistical analysis.It can be clearly seen from In summary, the full stress–strain curves of concrete with different solid waste coarse aggregates can explain the failure characteristics of concrete with different solid waste coarse aggregates more accurately, and the establishment of the principal structure models of different solid waste coarse aggregates can be applied to finite element analysis, which is also the basis for structural strength calculation, section ductility analysis, and structural internal force analysis.In order to test the accuracy of the fitting equation, three representative groups of NCAC, UCGC, and SCGC were selected, and six specimens of each group were formed and tested for the uniaxial compressive stress–strain curve of concrete after standard curing for 28 d. The test results showed that the error of NCAC is 4.83%, the error of UCGC is 8.92%, and the error of SCGC is 6.17%, which indicates that the modified Guo Zhenhai compressive stress–strain full curve prediction model has a better fit for both rising and falling sections and is recommended to be used.The elastic modulus of concrete is a necessary parameter to calculate the stress, deformation, and crack of structure and is an important index of engineering material performance. It can be seen from As mentioned above, most of the solid waste coarse aggregates had complex components, fluctuating quality, poor mechanical properties and stability, and other defects, leading to different solid waste coarse aggregate concrete moduli of elasticity less than the NCAC.(1)Although the different solid waste coarse aggregate concrete met the design requirements of the C30 concrete, the uniaxial failure process and morphology were different. Most of the coarse aggregates fractured in the failure sections of SCCC and SCGC, while they partially fractured in the UCGC and RCAC. The failure characteristics of GSWC, MSWC, and IWRC were similar to those of the NCAC, and the failure was mostly bonding failure between the coarse aggregate and cement mortar;(2)The uniaxial compressive stress–strain full curves of different solid waste coarse aggregate concrete have different shapes, and the slope of the rising section of the uniaxial compressive stress–strain full curve is smaller than that of NCAC, so the modulus of elasticity of different solid waste coarse aggregate concrete is smaller than that of NCAC. The effect of technical properties of solid waste coarse aggregates on the descending part is more obvious than that on the ascending part, and the peak compressive strain and ultimate compressive strain were both larger than those of the NCAC. All seven different solid waste coarse aggregate concrete damage forms showed typical brittle damage characteristics;(3)The micro-pumping of SCC and SCG mad the concrete have a better structure in the interfacial transition zone, but it was insufficient to compensate for the decrease in concrete strength caused by the breakage of the SCC and SCG. Because of the polished surfaces of the MSW and GSW, and the interfacial adhesions of the RCA and UCG, the interfacial transition zone was still the weakest area in the concrete under the present test conditions. For solid waste coarse aggregate concrete, the structure of the interfacial transition zone was key to its mechanical properties;(4)As a more mature principal structure model of ordinary concrete, the Guo Zhenhai model is still applicable to the description of the compressive stress–strain curve of solid waste coarse aggregate concrete. The compressive stress–strain curve of the solid waste coarse aggregate concrete was greatly influenced by the crushing value of solid waste coarse aggregate, pore structure, surface characteristics, etc. The establishment of a uniaxial compressive stress–strain full curve model of the different solid waste coarse aggregate concrete can provide a reference for the calculation analysis and design of different solid waste coarse aggregate concrete structures.


The efficacy of tivantinib may have some potential in treating MET-high hepatocellular carcinoma, and we aim to compare tivantinib with placebo for the treatment of MET-high hepatocellular carcinoma.  Several databases including PubMed, Cochrane Library, Web of Science, EBSCO, and EMbase have been systematically searched through March 2022, and we included studies regarding the treatment of MET-high hepatocellular carcinoma by using tivantinib versus placebo. P=0.21), progression-free survival (P=0.13), time to progression (P=0.38), or grade ≥3 anemia (P=0.50) but increases the incidence of grade ≥3 neutropenia (P=0.04).  We finally include three RCTs. In comparison with placebo for MET-high hepatocellular carcinoma, tivantinib reveals no significant influence on overall survival ( Tivantinib may provide no additional benefits for MET-high hepatocellular carcinoma. It is widely accepted that hepatocellular carcinoma results in poor prognosis . AdvanceP=0.03) [MET has been found to promote tumour development and metastasis by binding to hepatocyte growth factor (HGF) . One smaP=0.03) .Several studies have explored the application of tivantinib for MET-high hepatocellular carcinoma, with conflicting results . This meSeveral databases including Cochrane Library, PubMed, Web of Science, EBSCO, and EMbase have been systematically searched through March 2022, and we use the search terms “tivantinib” and “hepatocellular carcinoma”. Inclusion criteria are as follows: (1) patients are diagnosed as MET-high hepatocellular carcinoma, (2) treatments are tivantinib versus placebo, (3) outcomes should include overall survival, and (4) only RCT design is involved. We exclude patients with the history of HIV infection or liver transplantation.α-fetoprotein (AFP) > 200 ng/mL, and detailed methods of two groups.Two investigators extract the same information such as first author, patient number, age, female, Eastern Cooperative Oncology Group (ECOG) performance status, Overall survival is regarded as the primary outcome. Secondary outcomes are time to progression, progression-free survival, grade ≥3 neutropenia, and anemia. Progression-free survival indicates the time from randomization to the date of first disease progression or death. Time to progression is the time from randomization to the date of the first disease progression . NeutropThe risk of bias tool mainly includes performance bias, attrition bias, selection bias, reporting bias, detection bias, and other potential sources of bias . They ar2 statistic, and its value more than 50% suggests substantial heterogeneity [P < 0.05P < 0.05 is statistically significant.We assess RR or HR with 95% CI for outcomes. Heterogeneity is assessed by Iogeneity . The ranogeneity . We condThis meta-analysis was based on previously studies, so ethical approval and patient consent were not needed. It was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement and Cochrane Handbook for Systematic Reviews of Interventions . Review n = 85) or abstracts (n = 179). Two studies were removed because of the same patient samples after reading the full articles and three RCTs were ultimately included [included . The totincluded , and thets n = 17. Two stuincluded , two stuincluded , and twoincluded .P=0.21) for MET-high hepatocellular carcinoma in comparison with placebo, but significant heterogeneity is seen .Significant heterogeneity is observed. Thus, 95% prediction interval of overall survival is calculated, and it ranges from −1.24 to 2.80, which also shows no statistical difference between two groups. In addition, the study conducted by Santoro et al. may cause the heterogeneity . After eP=0.13; P=0.38; P=0.04; P=0.50; Comparised with placebo for MET-high hepatocellular carcinoma, tivantinib does not affect progression-free survival (HR = 0.77; 95% CI = 0.55 to 1.08; MET-high hepatocellular carcinoma commonly results in poor prognosis, but tivantinib treatment may have the potential in improving its overall survival . This stConsidering these negative results, several reasons may account for them. Firstly, MET expression may be not associated with the resistance to sorafenib in advanced hepatocellular carcinoma. Secondly, tivantinib may be not the effective MET inhibitor. Thirdly, there is lack of persistent MET activation after sorafenib therapy in advanced hepatocellular carcinoma . In addiDuring the sensitivity analysis, we find no heterogeneity after excluding one study . Among tRegarding the adverse events in this meta-analysis, tivantinib results in the increase in grade ≥3 neutropenia in MET-high hepatocellular carcinoma but has no obvious in grade ≥3 anemia. Tivantinib at the dose of 240 mg twice daily is not well tolerant for patients, and more methods should be used to control the adverse events. We should consider three shortcomings. Firstly, only three RCTs are involved, and we need more RCTs to confirm these findings. Secondly, there is significant heterogeneity which may result from different durations and doses of tivantinib. Thirdly, the underlying diseases of patients may affect the pooling results.Tivantinib may show no obvious improvement in clinical outcomes for MET-high hepatocellular carcinoma.


A prior study demonstrated suboptimal antibiotic prescribing in the emergency department (ED) at 77.4% for uncomplicated lower respiratory tract infections (LRTI), urinary tract infections (UTI), and acute bacterial skin and skin structure infections (ABSSSI). This study measured the effect of indication-based antibiotic order sentences (AOS) on prescribing.IRB-approved quasi-experiment of adults prescribed antibiotics in ED for uncomplicated LRTI, UTI, or ABSSSI from January - June 2019 (pre-group) or September - December 2021 (post-group). Exclusion: hospital admission, immunocompromised, active cancer, or prophylactic antibiotics. AOS are lean process, electronic discharge prescriptions retrievable by name or indication; AOS implementation occurred July 2021. Optimal prescribing was defined as the correct antibiotic selection, dose, and duration per local and national guidelines. Seven-day endpoints: antibiotic escalation, ED or hospital readmission, any outpatient contact, and reported adverse drug event (ADE). Descriptive and bivariate statistics performed. Variables considered for multivariable logistic regression had p< 0.2 or plausible association with optimal prescribing.294 patients included: 147-pre and 147-post. Patient characteristics are in Table 1. Overall optimal prescribing improved from 12 (8.2%) to 34 (23.1%) (p< 0.001). Breakdown of optimal prescribing in pre- and post-groups: selection 90 (61.2%) vs 117 (79.6%) (p< 0.001), dose 99 (67.3%) vs 115 (78.2%) (p=0.036), duration 38 (25.9%) vs 50 (34%) (p=0.126). After adjustment, AOS were independently associated with optimal prescribing (Table 2). Secondary endpoints: antibiotic escalation 10 (6.8%) vs 7 (4.8%) (p=0.662), hospital or ED readmission 12 (8.2%) vs 10 (6.8%) (p=0.658), outpatient contact 31 (21.1%) vs 28 (19%) (p=0.662), and ADE 2 (1.4%) vs 4 (2.7%) (p=0.684). Post-hoc analysis showed suboptimal uptake of AOS by ED prescribers.AOS is an efficient and promising antimicrobial stewardship strategy; provider re-education is needed to increase AOS uptake.All Authors: No reported disclosures.