Rebound Rate Research Articles

Investigations on the Performance of Shotcrete Using Artificial Lightweight Shale Ceramsite as Coarse Aggregate.

In this study, a type of artificial lightweight shale ceramsite (ALSC) was used as the coarse lightweight aggregate for shotcrete (LAS), of which the mechanical properties, chloride penetration ion resistance, and rebound behavior were investigated. Based on the experimental results on compressive, tensile, and bond strength, LAS meet the strength requirements, and the replacement rate of fly ash (FA) and silica fume (SF) are suggested to be kept at ~15% and 10%, respectively, to result in the best mechanical properties of LAS. Adding FA and SF to the mixture significantly improved the chloride ion penetration resistance (CPR) of LAS because of morphology effects and secondary hydration of FA and SF that lead to a denser microstructure of the mixture. The electric flux and chloride ion migration coefficient (DRCM) of LAS decreased by 56% and 67%, respectively, with FA increasing from 0 to 10%. The electric flux and DRCM further decreased by 71% (153C) and 66% (3.24 m2/s), respectively, with FA increasing from 10 to 20%. As 5–10% SF was further added, the electric flux and DRCM of LAS decreased to extremely low levels; for instance, with FA = 10% and SF = 10%, DRCM = 1.61 m2/s, and the electric flux was too small and could be ignored. The contact stresses between aggregate and shotcrete mixtures were measured to investigate the rebound trend of ALSC in shotcrete. According to the analyses of the theoretical model of the rebound behavior of aggregate in shotcrete proposed by Armelin and Banthia, because of the reduced contact stresses between ALSC and mortar and the smaller density of LAS compared with normal-weight aggregate, the rebound rate of ALSC was about half of that of normal-weight aggregate in the shooting process of the shotcrete.

Performance comparison test of new sprayed engineered cementitious composites and C25 sprayed concrete

The Wulingtou tunnel in Xuancheng City is faced with complex geological conditions in the construction process, and the construction is difficult. The research team of Anhui University of Science and Technology applied the new sprayed engineered cementitious composites (NS-ECC) to the initial support structure of K43 + 546.3-K43 + 556.7 section of the tunnel. The mechanical properties of NS-ECC were significantly improved compared with that of single fiber (1% volume content), and the compressive strength is ‘positive hybrid effect’. In this paper, the ordinary C25 sprayed concrete (SC-C25) was compared with NS-ECC to precisely evaluate their performance. Slump and rebound rate tests and uniaxial compression tests under four water-containing states and five loading rates were carried out, and the differences in performance were studied in detail via scanning electron microscope and nuclear magnetic resonance tests and based on energy evolution and transformation characteristics. Results show that the real water absorption and rebound rate of SC-C25 were significantly higher than those of NS-ECC. Increasing the water content reduced the compressive strength, peak strain and energy storage density of both cements yet increased their elastic modulus. In the saturated water state, increasing the loading rate also increased the compressive strength, elastic modulus and energy storage density limit values of both cements yet decreased their peak strain. NS-ECC reported higher strength, peak strain, energy storage density and sensitivity to the ‘Strain rate effect’, under the saturated state, its peak stress is 32.92 MPa, peak strain is 0.65%, the energy storage density limit is 0.01MJ/m3, and the elastic energy conversion rate reaches 95.9%, which are better than SC-C25.

On the evolution mechanism of permeability during gas drainage: Insights from deformation field, gas pressure field and temperature field

Permeability is an important factor affecting efficient gas drainage, ensuring coal mine process safety, ecological environment protection and clean energy capture. We develop a gas drainage physical simulation device with multi-physical coupling to study the dynamic response mechanism of permeability during gas drainage and explore the basic relationship between the interaction between boreholes and permeability during parallel borehole drainage. By installing 48 pressure sensors, 14 temperature sensors, and 9 displacement sensors in a test box, gas drainage tests of parallel boreholes with spacings of 250, 504, and 784 mm were carried out. The results show that during gas drainage in parallel boreholes, the dynamic evolution law of permeability in different spatial positions of the coal reservoir has apparent differences. The permeability near the borehole area exhibits a fast decline rate and a large recovery amplitude, and vice versa. The gas pressure, coal deformation, and coal temperature influence the periodical permeability evolution. In the early stage of drainage, gas pressure and coal temperature play a leading role in reducing permeability. In the middle and late stages, coal deformation slowly increases permeability. When the borehole spacing was 250 mm, the permeability decay rate and rebound rate were high with interaction between the boreholes; a drainage superposition area makes the permeability spatial variation difference between the boreholes significant. A correlation is observed between borehole spacing, gas migration rate, and permeability. The study is expected to have a substantial guiding significance for efficient gas drainage, decreasing greenhouse gas emissions, and improving coal mine process safety.

Estimating team possessions in high-level European basketball competition

The focus of this work is to estimate the number of team possessions in Euroleague basketball for seasons 2017–18, 2018–19 and 2019–20. To achieve this goal, we implemented the approaches proposed by Kubatko, et al. (2007). The statistical analysis on Euroleague data suggests a model similar to the one which is currently used in NBA with one, minor, difference. In Euroleague data, the coefficient of the percentage of the free throw attempts that ends a current possession is slightly higher than the corresponding coefficient in NBA (0.454 vs. 0.44). In a second stage, we have implemented the estimated Euroleague possessions equation in order to construct indicators for the performance evaluation of each Euroleague team. The most important indexes for team performance evaluation are the Net Rating and the Four Factors of Dean Oliver (2003). However, by applying a backwards stepwise regression analysis, a slightly improved model, in terms of fit to the data, has been identified. The new proposed “Three Pillars” model includes the offensive and defensive True Shooting percentage , Offensive Rebound percentage and Turnover percentage. Hence, this new proposed “Three Pillars” model can be used for the performance evaluation of European teams instead of the standard Four Factors model.

How has the COVID-19 pandemic changed the diagnosis of rectus sheath hematoma and its follow-up?

There has been an increased incidence of rectus sheath hematoma (RSH) due to chronic cough attacks and anti-coagulant therapy due to the COVID-19 pandemic. The present study aims to determine, in which parameters differ before and during the diagnosis of RSH in COVID-19 patients and what may be expected during diagnosis and follow-up. Thirty-five patients diagnosed with RSH were evaluated retrospectively between March 2016 and March 2021. The COVID-19 group comprised 11 patients. Various information including patient history and time of discharge/death were retrieved and compared between the experimental groups. The rates of hypotension on admission (p=0.011) and the rates of defense and rebound (p=0.030) were higher in the patients with COVID-19 than in those without. Although there was no difference in terms of bleeding width, there was a greater decrease in the hemoglobin levels (p=0.009) in the COVID-19 patients and the need for erythrocyte suspension (p=0.040) increased significantly in that group. The present study constitutes the first evaluation of RSH in COVID-19 patients. The clinical situation is serious due to high rates of hypotension, defense or rebound, and decreases in hemoglobin levels in COVID-19 patients. This makes the clinical management of RSH more difficult, resulting in longer hospitalization. Despite these difficulties, COVID-19 infection does not increase morbidity or mortality.

Comparative study on the successive impact behavior of composites in ship structures

Composite materials are categorized to be highly sensitive to low-velocity impact events. This feature is considered as a serious limitation for their application in engineering. Therefore, understanding impact energy absorption is critical in improving composite material damage tolerance and especially under successive impacts. This work was dedicated to an experimental investigation that aims to study and compare the energy absorption ability and damage behavior of PVC-foam sandwich and GFRP laminated composites under multiple impacts occurring at small energy levels. For this purpose, low-velocity impact repeated tests were carried out until total absorption of the impact initial energy was reached. A relative energy absorption index and a rebound index were proposed in order to assess energy absorption capacity. The results indicated that, directly after the first impact, the sandwich composite formed from two 4mm laminated skins absorbed 80% of the initial impact energy, in comparison to approximately 60% for 8mm laminated composite. This performance of sandwich composite is attributed to the damping ability of the core. Also, the impact velocity rebound rate of this composite was found to be higher than that of laminates. However, impact damage is greater in composite sandwiches than in laminates.

Glacial isostatic adjustment near the center of the former Patagonian Ice Sheet (48°S) during the last 16.5 kyr

Our understanding of glacial isostatic rebound across Patagonia is highly limited, despite its importance to constrain past ice volume estimates and better comprehend relative sea-level variations. With this in mind, our research objective is to reconstruct the magnitude and rate of Late Glacial and Holocene glacial isostatic adjustment near the center of the former Patagonian Ice Sheet. We focus on Larenas Bay (48°S; 1.26 km2), which is connected to Baker Channel through a shallow (7.4 m) and narrow (ca. 150 m across) inlet, and hence has the potential to record periods of basin isolation and marine ingression. The paleoenvironmental evolution of the bay was investigated through a sedimentological analysis of a 9.2 m long radiocarbon-dated sediment core covering the last 16.8 kyr. Salinity indicators, including diatom paleoecology, alkenone concentrations and CaCO3 content, were used to reconstruct the bay's connectivity to the fjord. Results indicate that Larenas Bay was a marine environment before 16.5 cal kyr BP and after 9.1 cal kyr BP, but that it was disconnected from Baker Channel in-between. We infer that the postglacial rebound started before 16.5 cal kyr BP and that it outpaced global sea-level rise until slightly before 9.1 cal kyr BP. During the Late Glacial and early Holocene, the center of the former Patagonian Ice Sheet experienced an absolute uplift of ca. 96 m, at an average rate of 1.3 cm/yr. During the remainder of the Holocene, glacial isostatic adjustment continued (ca. 20 m), but at a slower average pace of 0.2 cm/yr. Comparisons between multi-millennial variations in the salinity indicators and existing records of global sea-level rise suggest that the glacial isostatic adjustment rate also fluctuated within these time intervals, likely in response to glacier dynamics. More specifically, most of the glacial isostatic adjustment registered between 16.5 – 9.1 cal kyr BP seems to have occurred before meltwater pulse 1A (14.5 – 14.0 kyr BP). Likewise, it appears that the highest glacial isostatic rebound rates of the last 9.1 kyr occurred during the late Holocene, most likely in response to glacier recession from their Neoglacial maxima. This implies a relatively rapid response of the local solid earth to ice unloading, which agrees with independent modelling studies investigating contemporary uplift. We conclude that the center of the former Patagonian Ice Sheet experienced a glacial isostatic adjustment of ca. 116 m over the last 16.5 kyr, and that >80% occurred during the Late Glacial and early Holocene.

Facile preparation of a phenolic aerogel with excellent flexibility for thermal insulation

An ambient pressure drying, cost-effective and environment-friendly synthesis method for aerogels has been continuously pursued by scholars.However, phenolic aerogels are usually rigid and prepared from phenol and aldehyde monomers through complicated and long-time supercritical drying processes, which limit their production efficiency. This paper introduces an ambient pressure drying method for preparing lightweight and low-thermal-conductivity phenolic aerogels with excellent flexibility. The prepared flexible phenolic aerogels (FPAs) have a complete 3D network structure, low thermal conductivity (approximately 0.03 W/(m·K)) and excellent compressibility and recovery performance (compression strain can reach 50%, and rebound rate can reach 80%). Given their simple synthesis, simple scaling up and excellent mechanical properties, such flexible phenolic aerogels may have great potential to serve as thermal insulating materials.

Clinical Relevance of Isoagglutinin Rebound in Adult ABO-Incompatible Living Donor Liver Transplantation.

ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) can be performed successfully. However, anti-ABO isoagglutinin rebound may cause antibody-mediated rejection (AMR) and graft loss. The risk threshold of isoagglutinin rebound is still not defined. 76 ABO-I LDLT recipients were divided into group A (n = 56) with low isoagglutinin titers (<1:256), and group B (n = 20) with high isoagglutinin titers (≥1:256), at initial assessment for liver transplantation. The last 12 patients in group B received a modified desensitization regimen by adding bortezomib to deplete plasma cells. Six (10.7%) patients in group A and 10 (50.0%) patients in group B had postoperative isoagglutinin rebound (p < 0.001). Three patients (5.54%) in group A and two patients (10%) in group B developed clinical AMR (p = 0.602). The cutoff value of postoperative isoagglutinin rebound to cause clinical AMR was ≥1:1024. Among the 12 patients in group B with bortezomib administration, isoagglutinin rebounded up to 1:128 only, and no clinical AMR occurred. In conclusion, the patients with high isoagglutinin titers had a higher rate of postoperative isoagglutinin rebound. Isoagglutinin rebound ≥1:1024 is risky for developing clinical AMR. Adding bortezomib into the desensitization regimen may mitigate isoagglutinin rebound, and avoid clinical AMR.

Spraying characteristics of mining wet shotcrete

Taking the shotcrete in the coal mine as the background, the wet shotcreting technology is adopted to carry out the spraying characteristics test. Given the mix proportion of shotcrete in the coal mine, considering the influence of air pressure and sprayed distance, the spraying characteristics of shotcrete are studied, and the prediction model of mass flow rate is established. Based on the collected sprayed material in the process of shotcreting, the spatial distribution and composition of the sprayed materials are revealed. The research results show that the mass flow rate of shotcrete is more intensive in the central area around the axis of shotcrete. By comparing the mass distribution of shotcrete under different air pressures, it is found that excessive air pressure will cause in-place material collapsing during the placement process, resulting in a poor support effect. In addition, the relationship between spraying-up time and rebound rate, and the optimal initial spraying-up time are obtained. This paper provides theoretical and technical support for further study of spraying characteristics of wet shotcreting technology, which is helpful to promote the popularization and application of wet shotcrete.

Analysis of Decay of Photocatalytic Effect of Titanium Dioxide Electrode

Titanium Dioxide (TiO2) has been studied for its important photocatalytic semiconductor characteristics. Among many applicable areas of TiO2 photocatalysts, we have been studying to use as an anode electrode of the marine wet solar cells or marine microbial fuel cell. These studies include the analysis of TiO2 electrode prepared by the screen-printing method, and also the dye sensitizing effect on TiO2 electrode. In those studies, it was appeared that there is an open circuit potential that shifted to noble direction after TiO2 electrode was irradiated by the light source and measured its electrochemical properties. This phenomenon usually occurred after a few minutes the electrode showed its photocatalytic characteristics. It is unclear which caused the potential loss during the measurement. In this study, we have been trying to understand the mechanism affecting the potential degradation of the TiO2 electrode and the factors affecting that decay.The TiO2 electrodes were prepared by screen printing method. Type 329J4L stainless steel which exhibits duel phase properties was used as a base substrate for the electrode. Firstly, the surface of the substrate was polished and the substrate was cleaned with acetone using the ultrasonic cleaner for 10 minutes. Then, the substrate was passivated with 10% nitric acid (HNO3) solution at 60 ºC for 30 minutes. After that, the substrate was screen printed with TiO2 paste followed by heat treating for 60 minutes and the first layer of TiO2 was formed. For the second layer forming, the substrate was again screen printed with TiO2 paste and heat treated for 30 minutes. With these processes, double-layered heterojunction TiO2 electrode was prepared. The electrode was then coated with insulating epoxy resins and prepared ready for the electrochemical measurements and analysis.The electrochemical measurements of TiO2 electrodes were performed in an artificial seawater used as an electrolyte. The irradiation was carried out on the electrodes using a calibrated Xenon lamp with 150 W (wavelength ranging from 250 nm to 800 nm). The lamp was set to produce an output light intensity of 10.5 mW/cm2. The saturated calomel electrode (SCE) was used as the reference electrode. During the photopotential measurement, the potentials dropped to active direction as the electrodes were exposed to the light irradiation. But the potential values were ennobled rapidly after a few minutes the electrode was irradiated. Preliminary examinations showed that there is a relation between the rebounded potential values (open circuit potential loss) and the heat treatment temperatures of the electrodes. For example, the rebound rate of the electrode with second layer heat treatment temperature of 150 ºC was higher and longer compared to that of the electrode with 550 ºC one. Detailed mechanism was yet under investigation. Those investigation includes the photopotential measurement and the electrochemical impedance spectroscopy (EIS) analysis. The surfaces of the electrodes before and after the measurements of photopotential were compared and observed using the scanning electron microscope (SEM). The X-ray powder diffraction (XRD) analysis and differential thermal analysis (DTA) were also included for analysis of decay mechanism of photocatalytic on the TiO2 electrode. The results of those analyses and the mechanism affecting the open circuit potential decay in the TiO2 electrode will be presented to the upcoming ECS conference meeting.

Factors associated with fingolimod rebound: A single center real-life experience

Background It is still controversial whether the relapse experienced after discontinuation of fingolimod treatment is a rebound. Increasing cases of rebound have been reported in the literature. The rate of fingolimod rebound in patients after fingolimod cessation is reported between 5% and 52%. The present study aims to determine the rate of rebound after discontinuation of fingolimod treatment and the factors affecting the rebound.Methods This retrospective cohort study consists of adult MS patients who have been admitted to the Hacettepe University Hospital Neurology MS Center outpatient clinic between 2012 and 2020.Results During the study period, 642 patients received fingolimod and 23.1% discontinued the fingolimod treatment. Thirteen of 126 patients had a rebound (10.3%) after fingolimod discontinuation. The patients in the rebound group were significantly younger and washout period were significantly longer than those in the non-rebound group. After discontinuation of fingolimod treatment, the EDSS score of the rebound group was significantly higher than the non-rebound group, while Annualized Relapse Rates were similar.Conclusion Younger age, longer washout time, and previous treatment preferences may increase the occurrence probability of rebound. It is recommended that patients should be closely monitored after fingolimod discontinuation and appropriate disease-modifying therapy should be initiated as soon as possible.

Effect of Facial Parameters on the Incidence of Rejection and Artifacts on the Video Head Impulse Test

Background and Objectives: The video head impulse test (vHIT) is a useful tool that uses a high-speed infrared video camera and an inertial accelerometer to quantify the vestibulo-ocular reflex. Despite advancements in recording technology, physicians should be aware of measurement artifacts induced by examiners. However, little is known about the impact of facial anatomy on artifacts. Therefore, we investigated how variance in facial anatomy affects measurement artifacts. Materials and Methods: This study enrolled nine subjects from November 2018 through November 2019. A digital camera was used to measure facial parameters, including head ratio, binocular spacing, nasofrontal angle, depth of nasion, and pupil ratio. Two examiners performed vHITs with ICS Impulse System (GN Otometrics). All impulses were assessed for artifacts, including rejection, notch during head impulse (notchduring), notch after head impulse (notchafter), and rebound. Results: The rejection rate was significantly correlated with depth of nasion, as measured by the experienced examiner, and with pupil ratio, as measured by the inexperienced examiner. notchduring rate was significantly correlated with nasofrontal angle, as measured by the inexperienced examiner. Rebound rate was significantly correlated with head ratio, as measured by both examiners. Conclusions: Measurement artifacts were significantly correlated with head ratio, depth of nasion, nasofrontal angle, and pupil ratio. (J Clinical Otolaryngol 2021;32:101-110)

Markov modelling of viral load adjusting for CD4 orthogonal variable and multivariate conditional autoregressive mapping of the HIV immunological outcomes among ART patients in Zimbabwe

BackgroundThis study aimed to jointly model HIV disease progression patterns based on viral load (VL) among adult ART patients adjusting for the time-varying “incremental transients states” variable, and the CD4 cell counts orthogonal variable in a single 5-stage time-homogenous multistate Markov model. We further jointly mapped the relative risks of HIV disease progression outcomes (detectable VL (VL ≥ 50copies/uL) and immune deterioration (CD4 < 350cells/uL) at the last observed visit) conditional not to have died or become loss to follow-up (LTFU).MethodsSecondary data analysis of individual-level patients on ART was performed. Adjusted transition intensities, hazard ratios (HR) and regression coefficients were estimated from the joint multistate model of VL and CD4 cell counts. The mortality and LTFU transition rates defined the extent of patients’ retention in care. Joint mapping of HIV disease progression outcomes after ART initiation was done using the Bayesian intrinsic Multivariate Conditional Autoregressive prior model.ResultsThe viral rebound from the undetectable state was 1.78times more likely compared to viral suppression among patients with VL ranging from 50-1000copies/uL. Patients with CD4 cell counts lower than expected had a higher risk of viral increase above 1000copies/uL and death if their VL was above 1000copies/uL (state 2 to 3 (λ23): HR = 1.83 and (λ34): HR = 1.42 respectively). Regarding the time-varying effects of CD4 cell counts on the VL transition rates, as the VL increased, (λ12 and λ23) the transition rates increased with a decrease in the CD4 cell counts over time. Regardless of the individual’s VL, the transition rates to become LTFU decreased with a decrease in CD4 cell counts. We observed a strong shared geographical pattern of 66% spatial correlation between the relative risks of detectable VL and immune deterioration after ART initiation, mainly in Matabeleland North.ConclusionWith high rates of viral rebound, interventions which encourage ART adherence and continual educational support on the barriers to ART uptake are crucial to achieve and sustain viral suppression to undetectable levels. Area-specific interventions which focus on early ART screening through self-testing, behavioural change campaigns and social support strategies should be strengthened in heavily burdened regions to sustain the undetectable VL. Sustaining undetectable VL lowers HIV transmission in the general population and this is a step towards achieving zero HIV incidences by 2030.

Routine Cancer Screening Rates Rebound After Deep Drop From Pandemic Fear.

Routine Cancer Screening Rates Rebound After Deep Drop From Pandemic Fear.

Electric water heater flexibility potential and activation impact in system operator perspective – Norwegian scenario case study

Simultaneous activation of demand side flexibility on thermostatically controlled loads will cause adverse impacts later in the form of rebounds. Distribution system operators must know the characterisation of the impact, as they are responsible for voltage quality of power delivery and suffer the loss of lifespan of network components due to overloading. In this paper, characterising parameters for flexibility activation on electric water heaters (EWHs) are proposed and flexibility potentials are computed considering smart activation methods for the Norwegian scenario. The proposed parameters are rebound percentage, delay, ramp rates, second peak distance, activation error, flexible power, and temperature deviation. Four scenarios with different levels of flexible power and activation time are developed in the Norwegian context for quantification of the flexibility potentials and the parameters. The highest average flexible power potential is 53.9% at 8:00 a.m. for a duration of 61 min. EWHs flexibility activation can serve as Frequency Containment Reserves (FCR) at peak demand hours with high ramp-up and ramp-down rates of 48.5% and 23.8% per minute and as Frequency Restoration Reserves (FRR) during non-peak hours.

Application of Advanced Composite Cementitious Materials and High Performance Admixtures in High Performance Shotcrete

In this paper, the influence of liquid alkali-free accelerator and advanced composite cementitious materials on the mechanical properties, durability and workability of shotcrete was studied. The important role of the two materials in the performance improvement of shotcrete was clarified. The technical measures proposed were verified by field test. The results show that: In terms of workability, the composite use of alkali-free accelerator and functional admixture can achieve fast setting and high early strength of shotcrete, thus effectively reducing the rebound rate; In terms of mechanical properties, functional admixture can effectively improve the early mechanical properties of shotcrete, while alkali-free accelerator can ensure the long-term development of mechanical properties; In terms of durability, the use of functional admixtures can effectively improve the compactness of shotcrete, and the test results of 56d electric flux are lower than 1000C.

Does actual cropland water consumption change with evaporation potential in the Lower Yellow River?

The North China Plain (NCP) is one of the most important regions for food production in China; however, the typical winter wheat–summer maize cropping system has created a continuous decline in groundwater levels, triggering serious ecological problems. Additionally, changes in the evaporation potential in the NCP have altered from decreasing to sharply increasing. Therefore, it is critical to understand the actual cropland water consumption (i.e., the actual evapotranspiration, AET) and crop water use efficiency (WUE) under this new trend. This understanding is significant for agricultural water management in the NCP. This study investigated the historical AET and WUE trends for the winter wheat–summer maize cropping system during 1992–2014. This investigation was based on a long-term AET dataset obtained using a large lysimeter from 1992 to 2014 at the Yucheng Comprehensive Experiment Station of the Chinese Academy of Sciences near the Lower Yellow River. The results showed that annual AET decreased pre-2008 and rebounded post-2008. The rebound rate of annual AET from 2008 to 2014 was more than three times the annual decrease rate of AET from 1992 to 2008. The significant increase in summer maize AET mainly contributed to the rebound of the annual AET after 2008. Following the changes in AET and crop yield, the annual WUE had evidently increased for 1992–2008 and sharply decreased from 2008 to 2014. The significant decrease in winter wheat WUE mainly contributed to the annual decrease in WUE post-2008. Climate change, agricultural management, and crop yields were observed to regulate the changes in AET and WUE. In the context of accelerating climate change and the increased frequency of extreme climatic events, strategies to improve WUE by the Lower Yellow River have been proposed, which may also be helpful in the NCP and similar regions worldwide.

Efficacy and Safety of Propranolol vs Atenolol in Infants With Problematic Infantile Hemangiomas

Propranolol has become the first-line therapy for problematic infantile hemangiomas (IHs) that require systemic therapy. However, different adverse events have been reported during propranolol treatment. The positive efficacy and safety of atenolol raise the question of whether it could be used as a promising therapy for IH. To compare the efficacy and safety of propranolol vs atenolol in infants (between age 5 and 20 weeks) with problematic IHs who required systemic therapy. This was a prospective, multicenter, randomized, controlled, open-label clinical trial conducted in collaboration among 6 separate investigation sites in China from February 1, 2015, to December 31, 2018. A total of 377 patients met the criteria for inclusion and were randomized to the propranolol (190 [50.4%]) and atenolol (187 [49.6%]) groups. Data were analyzed in June 2020. Participants were randomized to receive either propranolol or atenolol for at least 6 months. They completed efficacy assessments at 2 years after the initial treatment. The primary outcome was any response or nonresponse at 6 months. The key secondary outcome was changes in the hemangioma activity score. Of 377 participants, 287 (76.1%) were female, and the mean (SD) age was 10.2 (4.0) weeks in the propranolol group and 9.8 (4.1) weeks in the atenolol group. After 6 months of treatment, in the propranolol and atenolol groups, the overall response rates were 93.7% and 92.5%, respectively (difference, 1.2%; 95% CI, -4.1% to 6.6%). At 1 and 4 weeks after treatment, and thereafter, the hemangioma activity score in the atenolol group aligned with the propranolol group (odds ratio, 1.034; 95% CI, 0.886-1.206). No differences between the propranolol group and atenolol group were observed in successful initial responses, quality of life scores, complete ulceration healing times, or the rebound rate. Both groups presented a similar percentage of complete/nearly complete responses at 2 years (82.1% vs 79.7%; difference, 2.4%; 95% CI, -5.9% to 10.7%). Adverse events were more common in the propranolol group (70.0% vs 44.4%; difference, 25.6%; 95% CI, 15.7%-34.8%), but the frequency of severe adverse events did not differ meaningfully between the groups. In this randomized clinical trial, when compared with propranolol, atenolol had similar efficacy and fewer adverse events in the treatment of infants with problematic IHs. The results suggest that oral atenolol can be used as an alternative treatment option for patients with IH who require systemic therapy. ClinicalTrial.gov Identifier: NCT02342275.

Workability, strength and toughness properties of different types of fiber-reinforced wet-mix shotcrete

The main focus of this study is to investigate the effects of macro steel (ST), forta-ferro (FF) and polyamide (PA) synthetic fibers on the slump, compressive, splitting tensile, flexural strength, flexural toughness and rebound rate of wet-mix shotcrete. The toughness capacities of fiber reinforced shotcrete (FRS) mixes was also evaluated in accordance with the JSCE SF-4 and CECS 13-2009 standards. The fiber volume fractions added into the shotcrete mixes are 0.25%, 0.5%, and 1%. The test results showed that when the fiber ratio is increased from 0.25% to 1%, slump values for all the FRS mixes decreased significantly and the highest decrease occurred for the PAFRS mixes. The ST fibers are highly more effective than PA and FF synthetic fibers to enhance the strength and toughness capacities of concrete due to ST fibers have higher tensile strength and outstanding geometrical shape. The CECS 13-2009 and JSCE-SF4 standards are sufficient to calculate the toughness capacities of FRS specimens up to their limit deflection values. However, if higher deflection values were used by these two standards, the significant contribution of all fibers in the inelastic region would be more realistically taken into account.