Test Variables Research Articles

Performance Evaluation of Architectural Modular Member with Ultra-High-Performance Fiber-Reinforced Concrete for Application

As the modular industry expands, the most widely used building materials are primarily concrete, steel, and wood. However, the use of wood and steel is severely limited compared to concrete for reasons such as durability and economy. To overcome these shortcomings, we aimed to apply ultra-high-performance fiber-reinforced concrete (UHPFRC), which has excellent compressive strength and tensile strength, high durability, and minimal reinforcement with steel fibers. In this study, research was conducted on the development of unit box-type architectural modules using UHPFRC with a compressive strength of 120 MPa and a tensile strength of greater than 7 MPa. Various amounts of steel fibers (Vf = 1.0, 1.5, and 2.0%) were evaluated to determine the optimal mixing ratio of UHPFRC, in which both the durability and mechanical performance were assessed. The compressive strength and tensile strength of UHPFRC were found to be 132 MPa and 10.1 MPa, respectively, while its resistance to chloride penetration averaged 14.47 coulombs, indicating superior durability compared to conventional concrete. To reduce the weight of the unit components of the architectural modular system, both normal concrete (NC) components and UHPFRC were applied. The main variables in the flexural tests were the cross-sectional thickness, steel fiber content, and presence of an insulation material, comprising a total of three variables for evaluating the flexural performance. The application of UHPFRC with a compressive strength of 120 MPa, a cross-sectional thickness of 120 mm, and a 10 mm diameter reinforcement provided a similar performance to that of NC components while reducing concrete usage by 60% compared to NC components. Additionally, structural analysis was performed to prototype the unit box-type modular structure using UHPFRC. The modular structural system developed in this study was found to reduce construction costs by 18.7% compared to traditional steel structural systems. Further research is necessary to address issues such as floor slab vibration and noise, connections, and expansion to multistory buildings for commercialization of modular structures using UHPFRC.

Nonlinear finite element and machine learning modeling of tubed reinforced concrete columns under eccentric axial compression loading

There is still insufficient data on the behavior of tubed-reinforced concrete columns (TRCCs) under the eccentric compression. Thus, this research work comprehensively examines the eccentric compression behavior of TRCCs using nonlinear finite element modeling and machine learning (ML). To do this, numerical simulation and parametric analysis based on existing investigations were conducted. In addition to the existing 22 specimens with limited test variables, additional 188 specimens were developed to cover a wide range of parameters, including the load eccentricity, transverse reinforcement spacing, columns’ slenderness ratio, yield strength of steel, and outer steel tube diameter. Additionally, six ML models were created to estimate the ultimate load results. The results indicated that increasing the outer steel tube yield strength and diameter, and reducing the load eccentricity, slenderness ratio, and spacing of the transverse reinforcement enhanced the load-carrying capacity of the columns. The Gaussian process regression model demonstrated superior performance metrics in comparison to other ML models, with the highest R2 values (0.998613 in training and 0.99823 in testing stages) and lowest root mean square error values (0.007213 in training and 0.008471 in testing stages). To save money, time, and resources compared to laboratory testing, an online-based prediction program is finally presented to predict the columns’ ultimate load.

Cardiodynamic adjustments in skilled civil aircraft pilots while unexpected emergency conditions appeared during a simulated flight within a homemade Airbus A300 cockpit

To highlight which cardiodynamic adjustments take place in civil aircraft pilots when unexpected mechanical accidents occur while they are in flight, in 8 skilled pilots we detected the mean blood arterial pressure (MAP) and heart rate (HR) while a unexpected failing of one engine occurred when they were engaged in a simulated flight with a homemade Airbus A300 cockpit. Comparing these two cardiovascular variables in a simulated flight test, just as when the accident happened, together with the values assessed in a simulated control flight without accidents, by the non-parametric Wilcoxon test for paired data it has been found a significant increase of MAP’s median (+ 20.3%, P = 0.008) without significant increase in HR one. However, in several tested pilots this sudden MAP increase tended to progressively recover baseline values while simulating the flight despite the event triggering this functional response was still present.We concluded that the cardiovascular apparatus of skilled aircraft civil pilots adapts in such a way of sudden respond to unexpected emergency conditions by adjusting mean arterial blood pressure for adequate blood flow to limb muscles, and this happens without a concomitant tachycardia response in order to maintain an optimal mechanical/metabolic efficiency of the heart.

Visible minority status and occupation were associated with increased COVID-19 infection in Greater Vancouver British Columbia between June and November 2020: an ecological study.

The COVID-19 pandemic has highlighted health disparities, especially among specific population groups. This study examines the spatial relationship between the proportion of visible minorities (VM), occupation types and COVID-19 infection in the Greater Vancouver region of British Columbia, Canada. Provincial COVID-19 case data between June 24, 2020, and November 7, 2020, were aggregated by census dissemination area and linked with sociodemographic data from the Canadian 2016 census. Bayesian spatial Poisson regression models were used to examine the association between proportion of visible minorities, occupation types and COVID-19 infection. Models were adjusted for COVID-19 testing rates and other sociodemographic factors. Relative risk (RR) and 95% Credible Intervals (95% CrI) were calculated. We found an inverse relationship between the proportion of the Chinese population and risk of COVID-19 infection (RR = 0.98 95% CrI = 0.96, 0.99), whereas an increased risk was observed for the proportions of the South Asian group (RR = 1.10, 95% CrI = 1.08, 1.12), and Other Visible Minority group (RR = 1.06, 95% CrI = 1.04, 1.08). Similarly, a higher proportion of frontline workers (RR = 1.05, 95% CrI = 1.04, 1.07) was associated with higher infection risk compared to non-frontline. Despite adjustments for testing, housing, occupation, and other social economic status variables, there is still a substantial association between the proportion of visible minorities, occupation types, and the risk of acquiring COVID-19 infection in British Columbia. This ecological analysis highlights the existing disparities in the burden of diseases among different visible minority populations and occupation types.

Analisa Karakteristik Pengujian Co-Firing Biomassa Bagasse Tebu di PLTU Rembang Kapasitas 2×315 MW

Energy utilization in power plants in Indonesia significantly relies on fossil energy sources, especially those obtained from power plants that use coal as the main fuel. The aim of testing co-firing of sugarcane bagasse biomass is to determine the effect of co-firing on the reliability and main parameters of coal-fired power plants and to obtain an overview of the feasibility of implementing co-firing which includes aspects of operational technical evaluation, production cost evaluation and environmental evaluation. The biomass effectiveness test was carried out at PLTU Rembang, with test variables of 100% coal, co-firing test of 1.25% and 2.5% sugarcane bagasse biomass with a maximum operational load of 315 MW for 6 hours. The results of data analysis were carried out descriptively. The tested sugarcane bagasse biomass had a calorific value of 2947 kCal/kg. Meanwhile, the coal used in PLTU Rembang has a calorific value of 4286 kcal/kg. The SO2 emission test results decreased in the Co-firing test of 1.25% sugarcane bagasse and increased in the Co-firing test of 2.5% sugarcane bagasse compared to the 100% coal test, while the NOx emission test results produced during the co-firing test firing 1.25% and 2.5% sugarcane bagasse biomass has a lower value than using 100% coal. The cost of co-firing electricity production from sugarcane bagasse biomass is 1.25% and 2.5% cheaper than the cost of producing 100% coal electricity. To reduce electricity production costs, the sugarcane bagasse biomass co-firing scheme needs to be emphasized by referring to HPT determination in accordance with PLN Perdir No.0004/DIR/2022, so that co-firing electricity production costs can be more economical.

Relationship between ankle dorsiflexion range of motion and sprinting and jumping ability in young athletes

ObjectivesTo investigate the relationship between predicted risk of injury based on the dichotomous classification of the weight-bearing lunge (WBL) test scores and variables related to jumping and sprinting ability in young athletes. Furthermore, to compare the impact of the classical dichotomous classification versus a more specific quartile subdivision of the WBL test scores on the explored variables. DesignCross-sectional study. Participants125 healthy athletes (mean age 10.38 (SD = 2.28) years) were recruited. Main outcome measuresAnkle dorsiflexion was evaluated with the WBL test, jumping distance with the standing long jump (SLJ) test, and maximal running speed with the 14-m and 28-m sprint test. ResultsAthletes with WBL test scores lower than 10 cm exhibited significantly poorer results for the SLJ test as well as lower 14-m and 28-m sprint times than those with WBL test scores higher than 10 cm (p < 0.05). Likewise, when WBL test scores were subdivided by quartiles, a positive trend between range of motion and improved performance was shown. ConclusionsReduced ankle dorsiflexion mobility may affect sprinting and jumping ability in young athletes. In addition, a more detailed classification of ankle restriction by quartiles is proposed in this study in order to prevent injury and enhance athletic performance.

Effects of sustained natural apophyseal glides versus rocabado 6 × 6 program in subjects with cervicogenic headache

BackgroundCervicogenic headache is designated as the most common type of secondary headache that results from conditions affecting the neck’s bony components, muscles, and intervertebral discs rather than the head itself.ObjectiveThe purpose was to determine the effects of Sustained Natural Apophyseal Glides (SNAGs) versus the Rocabado 6 × 6 program in subjects with cervicogenic headaches.MethodsThis study was a randomized clinical trial. The sample size was 38, and participants aged 20–60 years (mean age 40.22 ± 9.66) suffering from cervicogenic headaches were randomly allocated using the lottery method into two groups with 19 participants in each group. Assessment of subjects was done before starting treatment and by the end of the 8th week for all the variables. Outcome measures were the Neck Disability Index (NDI), 6-item Headache Impact Test (HIT-6), Flexion-Rotation test (FRT) to assess the rotation range of motion at the level of C1-C2 (goniometer) and the Numeric Pain Rating Scale (NPRS) for the intensity of pain. Data analysis was done by SPSS (IBM) 25. To check the normality of the data the Shapiro-Wilk test was used.ResultsIn the Shapiro-Wilk test p-value of all the testing variables i.e. NDI, HIT-6 score, FRT and NPRS was > 0.05, data was normally distributed and parametric tests were used. Group A showed a considerable improvement (p < 0.05) in all variables compared to Group B, while within-group analysis of both groups shows that all outcome measures show significant results (p < 0.05).ConclusionIt was concluded that both SNAGs and Rocabado’s 6 × 6 exercises were effective for the treatment of cervicogenic headache but the effects of headache SNAG were superior and produced more improvement in intensity of headache, disability, frequency of headache, duration of headache as compared to Rocabado 6 × 6 exercises.Trial registration numberThis study was registered at ClinicalTrials.gov ID: NCT05865808 on date 19/05/2023.

Repairing Performance of Polymer-Modified Cement-Based Thin Spray-On Liners on Pre-Cracked Rock-like Specimens

With the development of coal mining and the increase in excavation depth, the stress on roadway surrounding rock is also increasing. This creates conditions for crack development in the roadway, so it is urgent to develop rock repair materials with excellent performance. The ability of thin spray-on liner (TSL) to repair rock and concrete opens up the possibility of reusing abandoned roadways. The ability of TSL to support the surrounding rock is also important in preventing the generation of roadway waste. In this paper, styrene–acrylic emulsion (SAE), vinyl acetate–ethylene copolymer emulsion (VAE), and polyvinyl alcohol powder (PVA) were used to prepare three TSLs. Rock-like materials were configured using cement mortar according to similar principles. Three types of TSLs were tested for basic properties such as viscosity and mechanical strength, which provided data to support the explanation of the repair performance of TSLs. Three TSLs were used to repair pre-cracked rock-like specimens (PR). The number of brushing times and the angle of PR’s cracks were regarded as test variables. Changes in the mechanical strength of repaired PRs were tested by compressive and flexural tests. TSL repair performance was evaluated with the help of mechanical strength changes. Results show that polyvinyl alcohol powder modified cement-based thin spray-on liner is most suitable for repairing rock cracks; as the thickness of the brush slurry increases, its repair performance continues to improve. This paper can provide experience and a theoretical basis for the research of other rock repair materials, and it is also instructive for repairing shotcrete in the roadway.

Assisting the implementation of screening for type 1 diabetes by using artificial intelligence on publicly available data

The type 1 diabetes community is coalescing around the benefits and advantages of early screening for disease risk. To be accepted by healthcare providers, regulatory authorities and payers, screening programmes need to show that the testing variables allow accurate risk prediction and that individualised risk-informed monitoring plans are established, as well as operational feasibility, cost-effectiveness and acceptance at population level. Artificial intelligence (AI) has the potential to contribute to solving these issues, starting with the identification and stratification of at-risk individuals. ASSET (AI for Sustainable Prevention of Autoimmunity in the Society; www.asset.healthcare) is a public/private consortium that was established to contribute to research around screening for type 1 diabetes and particularly to how AI can drive the implementation of a precision medicine approach to disease prevention. ASSET will additionally focus on issues pertaining to operational implementation of screening. The authors of this article, researchers and clinicians active in the field of type 1 diabetes, met in an open forum to independently debate key issues around screening for type 1 diabetes and to advise ASSET. The potential use of AI in the analysis of longitudinal data from observational cohort studies to inform the design of improved, more individualised screening programmes was also discussed. A key issue was whether AI would allow the research community and industry to capitalise on large publicly available data repositories to design screening programmes that allow the early detection of individuals at high risk and enable clinical evaluation of preventive therapies. Overall, AI has the potential to revolutionise type 1 diabetes screening, in particular to help identify individuals who are at increased risk of disease and aid in the design of appropriate follow-up plans. We hope that this initiative will stimulate further research on this very timely topic.Graphical

CRITICAL ANALYSIS OF POWDER FLOW BEHAVIOUR OF DIRECTLY COMPRESSIBLE COPROCESSED EXCIPIENTS

The aim of this pre-formulation study was to adopt simple linear regression modelling and correlation statistics to understand the associations between pharmacopoeial powder test methods using datasets generated from five commercial brands of directly compressible excipients with a specific focus to inferential implications in formulation design. Powder characterization was conducted using protocols defined in Chapter &lt;1174&gt; and &lt;616&gt; of the United States Pharmacopoeia (USP41-NF36). The study adopted a linear regression modelling analytics and correlation statistics using the fitting algorithm of OriginPro® (OriginPro, Version 2021b, OriginLab Corporation, Northampton, MA, USA). In the results, the modulus of Pearson’s product moment correlation coefficient was used to measure the strength of the linear association between test variables and a correlation matrix generated. Strong positive correlation modulus of Hausner’s Ratio (HR) with Carr’s index (r=+0.999) and static angle of repose (r=+0.932) were evident. Bulk density strongly correlates with tap density in the positive direction (r=+0.911). Tap density also shows a slight negative correlation with HR (r=-0.230), Carr’s index (r=-0.228), and static angle of repose (r==-0.421), while Carr’s index strongly correlated with static angle of repose (r=+0.933). In conclusion, modelling bivariate powder flow datasets has provided a powerful but simplistic statistical relationship for characterizing the modulus of association between HR, Carr’s index, and static angle of repose of the model excipients useful in preformulation design of pharmaceutical formulations.

Experimental investigation on strengthening lap joints subjected to bending in glulam timber beams using CFRP sheets

Abstract Strengthening the carpentry joints is considered a big challenge for designers to maintain the joined timber elements’ load transfer and integrity. This research work investigates different techniques to strengthen the lap joints in glulam timber beams using carbon fiber-reinforced polymer (CFRP) sheets. For this purpose, 12 specimens of glulam timber beams were tested using the four-point loading method. One of the glulam timber specimens was an intact nonlapped specimen, and the others were lapped at mid-span using half-height lap joints. The lap joints were strengthened using different configurations of the CFRP sheets. The test variables were the clamping scheme, bond length, and reinforcement ratio of the CFRP sheets. The analysis of the test results indicates that the CFRP strengthening configuration could be more effective in strengthening the lapped glulam timber beams when the reinforcement ratio of the longitudinal CFRP sheets was equal to 0.303%, and the wrapping CFRP sheets continued beyond the lapped joint by a distance equal to the beam height. Such a strengthening configuration could succeed in increasing the effective stiffness and ultimate load of the lapped timber specimen to 109 and 110%, respectively, relative to those of the intact nonlapped specimen. Moreover, the results reveal that increasing the length or the reinforcement ratio of the longitudinal CFRP sheets without increasing the width of the wrapping CFRP sheets could not succeed in achieving the required improvements in the structural behavior of the lapped timber beams.

Discriminant ability of novel cognitive-motor assessments to distinguish between fallers and non-fallers – Preliminary findings

Introduction&#x0D; Falls are a major cause for injuries in older adults and are associated with motor and cognitive impairments (Hsu, 2012). Thus, sensitive assessment tools capturing subtle changes in motor and cognitive functioning are crucial for the prediction of falls. Aim of this study was to test the ability of a novel, instrumented, cognitive-motor assessment battery, to distinguish between older persons who experienced a fall in the past 12 months (fallers) and persons who did not (non-fallers) as well as its added value to predict fall status compared to gold-standard clinical fall risk assessments.&#x0D; Methods&#x0D; This is a secondary analysis using baseline data of an international randomized controlled trial. Participants (age &gt; 60, categorized in two groups: fallers and non-fallers) performed five instrumented tests (Reaction time test (psychomotor speed), Flexibility test (mental flexibility), Go/No-Go task (inhibition), Sway test (postural control), and Coordinated Stability test (dynamic balance control), as well as the Timed-up and Go (TUG) test as a gold standard assessment. Binominal logistic regression analyses were conducted for each cognitive-motor assessment separately to identify test variables significantly associated with group assignment which could then be included in a further logistic regression model. Furthermore, a Receiver Operating Characteristic (ROC) analysis was performed.&#x0D; Results&#x0D; Preliminary results of n = 38 showed among the instrumented assessments only inhibition (p = .016) and dynamic balance control (p = .014) were significantly associated with fall status and therefore included in the second regression model. In this second model, both functions contributed significantly in predicting fall status (inhibition: p = .040, dynamic balance control: p = .028). This regression model was statistically significant and resulted in a good amount of explained variance (χ2(2) = 14.283 (p = .001), R2 = .418) with a sensitivity of 84.2% and a specificity of 73.7%. Similarly, the ROC analysis showed significant Area under the Curve (AUC) values only for inhibition (AUC = .751, p = .008) and dynamic balance control (AUC = .765, p = .005), whereas the AUC value of the TUG test remained non-significant (AUC = .681, p = .056).&#x0D; Discussion/Conclusion&#x0D; Based on this preliminary analysis, two tests of the novel instrumented cognitive-motor assessment battery assessing inhibition and dynamic balance control were able to distinguish between fallers and non-fallers and these tests showed better discriminative properties compared with the TUG. This supports the results of previous research which showed only limited discriminant validity of the TUG in terms of fall risk (Schoene et al., 2013). Therefore, the cognitive-motor assessments might provide an added value for clinical fall risk assessment. The study is still ongoing, and thus, the complete results (of N = 145) will be presented at the conference.&#x0D; References&#x0D; Hsu, C. L., Nagamatsu, L. S., Davis, J. C., &amp; Liu-Ambrose, T. (2012). Examining the relationship between specific cognitive processes and falls risk in older adults: A systematic review. Osteoporosis International, 23, 2409-2424. https://doi.org/10.1007/s00198-012-1992-z&#x0D; Schoene, D., Wu, S. M. S., Mikolaizak, A. S., Menant, J., Smith, S. T., &amp; Delbaere, K. (2013). Discriminative ability and predictive validity of the timed up and go test in identifying older people who fall: Systematic review and meta-analysis. Journal of the American Geriatrics Society, 61, 202-208. https://doi.org/10.1111/jgs.12106

The Value of Strength as a Predictor of Musculoskeletal Injury in Canadian Armed Forces Basic Infantry Candidates.

Musculoskeletal injuries (MSKI) impact military organizations by threatening their operational readiness, warranting investigation into relevant factors to inform risk reduction strategies. While several self-reported and physical performance measures have been associated with MSKI among military personnel, few have been validated and none have been reported in Canadian basic infantry candidates. The purpose of this study was to investigate associations between self-reported and physical performance measures and MSKI, and determine their validity as predictors of MSKI, in Canadian basic infantry candidates. This was a planned secondary analysis of a study tracking MSKI at a basic infantry training facility in Ontario, Canada approved by Defence Research & Development Canada. Before the basic infantry training, consenting candidates completed a baseline testing session including self-reported questionnaires, measures of anthropometry, and physical performance previously associated with MSKI (ankle dorsiflexion test, Y-Balance Test, Isometric Mid-Thigh Pull, and the Fitness for Operational Requirements of CAF Employment (FORCE) evaluation). All MSKI reported by candidates were diagnosed by licensed healthcare providers. From a total sample of 129 candidates, 76% (n = 98) were used to determine any associations between baseline testing variables and MSKI and to develop a predictive model (Development Sample), while 24% (n = 33) were used to offer preliminary validation of the same predictive model (Validation Sample). The binary logistic regression and independent sample t-testing determined independent associations with MSKI in the Development Sample. All continuous variables and dichotomous variables previously associated with MSKI risk (Smoker Yes/No, previous history of MSKI, and physical inactivity) were entered into a backward stepwise logistic regression analysis to assess the predictive association with MSKI incidence in the Development Sample. The regression model was then applied to the Validation Sample. A total of 35 MSKI were diagnosed by Health Services Centre staff. The majority of the MSKI were acute (63%), sustained to the hip, knee, and ankle (74%). The most common diagnoses were strains and sprains (71%). Uninjured participants performed significantly better on the Relative Isometric Mid-Thigh Pull, FORCE 20 mR, FORCE ILS, and FORCE Estimated VO2peak compared to injured participants. Logistic regression analysis showed that the only variable with significant independent association with diagnosed MSKI incidence was self-reported previous history of MSKI. However, the backward stepwise logistic regression analysis retained self-reported previous history of MSKI, FORCE SBD, FORCE Estimated VO2peak, and Isometric Mid-Thigh Pull Peak Force as predictors of MKSI. The logistic regression model including these variables could predict MSKI with an accuracy of 79% in the Development Sample and 67% in the Validation Sample. This study provides preliminary support for the value of measures of absolute muscular strength and cardiorespiratory fitness as predictors of MSKI in Canadian basic infantry candidates. Given the associations between physical performance measures and MSKI, and their necessity during occupational tasks, it is recommended that Canadian basic infantry training facilities integrate resistance training with external loads to best prepare their candidates to meet their occupational demands and potentially minimize MSKI. Further investigations to confirm the predictive capacity of these variables in a larger sample across additional facilities are warranted.

Experimental Research on Fatigue Behavior of Reinforced UHPC-NC Composite Beams under Cyclic Loading.

Ultra-high-performance concrete (UHPC), a new cement-based material that offers high mechanical strength and good durability, has been widely applied in construction and rehabilitation projects in recent years. An optimum bending system is achieved by positioning the UHPC layer at the bottom tensile zone of the composite beam and placing the normal-strength concrete (NC) layer at the upper compression zone, which is described as the UHPC-NC composite beam. The fatigue behavior of reinforced UHPC-NC composite beams was described in this study, with an emphasis on the effects of UHPC layer thickness and fatigue load level on the fatigue life of the beam, deformation of the interface between UHPC and NC layers, as well as the bending stiffness of the beam. A total of 9 reinforced UHPC-NC composite beams were tested under cyclic loading. The test variables include UHPC layer thicknesses (zero, 200, and 360 mm), reinforcement ratios (1.184% and 1.786%), and the upper load levels (0.39~0.65). The results showed that good bonding had been achieved without delamination between UHPC and NC layers prior to the final fatigue failure of the beam, and the bending stiffness of the composite beam experienced a three-stage reduction under cyclic loading. Furthermore, an equation was proposed to predict the stiffness reduction coefficient of UHPC-NC composite beams under cyclic loading.

Abstract WP226: Perioperative Stroke and Cardiac Anomalies Associated With Posterior Cerebral Artery Stenosis in Children With Moyamoya

Introduction: Moyamoya is a progressive steno-occlusive arteriopathy of the intracranial circulation affecting the anterior circulation and less often the posterior circulation. Risk factors and severity of disease progression in children with moyamoya and posterior cerebral artery (PCA) stenosis have not been well described in the literature. Previous research has shown an association between PCA stenosis and increased risk of post-operative stroke. We wanted to further explore this relationship in children with moyamoya and delineate the associated risk factors. Methods: Children with moyamoya who underwent surgical revascularization at our institution between December 2015 and December 2022 were reviewed for presence of PCA stenosis. Clinical and radiographic features were compared between children with moyamoya with and without PCA involvement. Categorical variables were compared using Fisher's exact test and continuous variables using Wilcoxon rank-sum. Associations between perioperative stroke and PCA stenosis were analyzes using a multivariate logistic regression. Results: In our cohort of 160 children with moyamoya, 45 (28%) had PCA stenosis; 26 of these 45 (57%) had PCA stenosis at time of diagnosis. Of the 19 children who did not have PCA stenosis at time of diagnosis but developed it during follow up, the median time to development of PCA stenosis was 1.0 years. Children with moyamoya and PCA stenosis had significant more cardiac anomalies than those without (p=0.02). Other associated disorders were found in 13 (28%) including trisomy 21 (6, 13%), cranial radiation (2,4%) and NF1 (3,7%). Interestingly, we found no significant difference in age, sex or prevalence of bilateral disease between the groups. Children with moyamoya and PCA stenosis had a 3.5 higher odds of having a stroke within 2 weeks of surgery (p=0.049). Conclusion: Children with moyamoya and PCA stenosis had a 3 fold higher odds of perioperative stroke compared to those without PCA stenosis. Genetic evaluations may be warranted given association of PCA stenosis and cardiac anomalies.

Hip and Pelvis Movement Patterns in Patients With Femoroacetabular Impingement Syndrome Differ From Controls and Change After Hip Arthroscopy During a Step-Down Pivot-Turn Task

Background: Alterations in hip kinematics during functional tasks occur in positions that cause anterior impingement in patients with femoroacetabular impingement (FAI) syndrome. However, tasks that do not promote motions of symptomatic hip impingement remain understudied. Purpose: To compare movement patterns of the hip and pelvis during a step-down pivot-turn task between patients with FAI and controls as well as in patients with FAI before and after hip arthroscopy. Study Design: Controlled laboratory study. Methods: Three-dimensional motion capture was acquired in 32 patients with FAI and 27 controls during a step-down pivot-turn task. An FAI subsample (n = 14) completed testing 9.2 ± 2.0 months (mean ± SD; range, 5.8-13.1 months) after hip arthroscopy. Statistical parametric mapping analysis was used to analyze hip and pelvis time series waveforms (1) between the FAI and control groups, (2) in the FAI group before versus after hip arthroscopy, and (3) in the FAI group after hip arthroscopy versus the control group. Continuous parametric variables were analyzed by paired t test and nonparametric variables by chi-square test. Results: There were no significant differences in demographics between the FAI and control groups. Before hip arthroscopy, patients with FAI demonstrated reduced hip flexion ( P = .041) and external rotation ( P = .027), as well as decreased anterior pelvic tilt ( P = .049) and forward rotation ( P = .043), when compared with controls. After hip arthroscopy, patients demonstrated greater hip flexion ( P &lt; .001) and external rotation of the operative hip ( P &lt; .001), in addition to increased anterior pelvic tilt ( P≤ .036) and pelvic rise ( P≤ .049), as compared with preoperative values. Postoperatively, the FAI group demonstrated greater hip flexion ( P≤ .047) and lower forward pelvic rotation ( P = .003) as compared with the control group. Conclusion: Movement pattern differences between the FAI and control groups during the nonimpingement-related step-down pivot-turn task were characterized by differences in the sagittal and transverse planes of the hip and pelvis. After hip arthroscopy, patients exhibited greater hip flexion and external rotation and increased pelvic anterior tilt and pelvic rise as compared with presurgery. When compared with controls, patients with FAI demonstrated greater hip flexion and lower pelvic forward rotation postoperatively. Clinical Relevance: These findings indicate that hip and pelvis biomechanics are altered even during tasks that do not reproduce the anterior impingement position.

Machine learning based on blood test biomarkers predicts fast progression in advanced NSCLC patients treated with immunotherapy

ObjectiveFast progression (FP) represents a desperate situation for advanced non-small cell lung cancer (NSCLC) patients undergoing immune checkpoint inhibitor therapy. We aimed to develop a predictive framework based on machine...

P340 The association between colon pseudopolyps presence and clinical adverse events in UC patients treated with biologics

Abstract Background Colon pseudopolyps (aka post-inflammatory polyps) are potential marks of previous severe ulcerative colitis (UC) activity. The association between outcomes of patients treated for UC with biologics and presence (or lack of presence) of pseudopolyps, are unclear. Methods A single center, noninterventional retrospective cohort review study was performed on real-life data of adult patients with moderate-to-severe UC who were treated with biologics (infliximab, vedolizumab, ustekinumab) for a minimum of 6 months. The difference in first occurence of treatment failure defined as a negative composite outcome (need for steroid rescue therapy, biologic switch, IBD-related hospitalization and/or surgery) between two groups (with or without pseudopolyps) was investigated. Participants’ characteristics were assessed using descriptive statistics. Normal distribution was assessed using Kolmogorov-Smirnov and Shapiro-Wilk tests. Categorical variables were analyzed using Chi-square test and continuous variables using Mann-Whitney test. Kaplan-Meier analysis and log-rank test were used in order to assess difference in therapy duration between two groups. Results Total of 92 patients (51% females; smokers 17%; 24% with pseudopolyps) were included. There were no differences in key baseline characteristics such as age, sex, smoking status, extraintestinal manifestations, serum albumin and CRP as well as fecal calprotectin levels between groups of patients with or without pseudopolyps. Median duration of follow up was 18.5 months (IQR 8-37). Presence of pseudopolyps was not associated with a higher risk for treatment failure; there was no statisticaly significant difference in the occurrence (χ2(1, N =91)=1.38, p=0.31) of negative composite outcomes or time to develop negative composite factor (χ2(1, N =91)=1.57, p=0.21). Conclusion In our cohort we have failed to detect any association between presence of colon pseudopolyps and rates of first occurence of treatment failure in UC patients treated with biologics.

P667 Benefit of 5-ASA continuation on UC disease outcomes following initiation of a biologic

Abstract Background In the era of advanced therapeutics for treatment of ulcerative colitis (UC) the benefit of routinely prescribed concomitant 5-aminosalicylate (5-ASA) compounds is still unclear. Methods A single centre, noninterventional retrospective cohort review study was performed on real-life data of adult patients with moderate-to-severe UC who were treated with biologics (infliximab, vedolizumab, ustekinumab) for a minimum of 6 months with or without concomitant use of 5-ASA. The difference in further treatment failure defined as a clinical negative composite outcome (need for steroid rescue therapy, biologic switch, IBD-related hospitalization and/or surgery) in two groups (5-ASA + biologic combination therapy vs biologic monotherapy) was assessed. Participants’ characteristics were assessed using descriptive statistics. Normal distribution was assessed using Kolmogorov-Smirnov and Shapiro-Wilk tests. Categorical variables were analysed using Chi-square test and continuous variables with Mann-Whitney test. Kaplan-Meier analysis and log-rank test were used in order to assess difference in therapy duration between two groups. Results Total of 104 patients (47.1% females; smokers 17.6%; concomitant stable dose oral 5-ASA 33%) were included. There were no differences in key baseline characteristics such as age, sex, smoking status, extraintestinal manifestations, serum albumin and CRP as well as fecal calprotectin levels between groups of patients receiving 5-ASA co-treatment and patients without 5-ASA. Median duration of therapy was 21 months (IQR 9-40). Concomitant use of 5-ASA was not associated with improved clinical outcomes; there was no statistically significant difference in the occurrence (χ2(1, N =102)=2.2, p=0.14) or time to develop (χ2(1, N =102)=1.12, p=0.29; Figure 1.) negative composite outcomes. Conclusion In our cohort we have failed to detect any benefit of 5-ASA continuation on significant clinical adverse events or hospitalisations in UC following initiation of a biologic.

Belief That Caffeine Ingestion Improves Performance in a 6-Minute Time Trial Test without Affecting Pacing Strategy.

Thirteen recreationally trained males in long-distance running (age: 38.5 ± 11.9 years, 11.0 ± 8.8 years of running experience) performed a 6 min time trial test in each experimental condition (caffeine-informed/placebo ingested (placebo) and non-ingested (control)) separated by 7 days. The total distance covered was measured, and partial times of each 400 m were used to analyze the pacing strategy. Heart rate and kinematic variables were recorded for each split. In addition, the rate of perceived exertion and prevalence of caffeine side effects was measured using questionnaires. Placebo ingestion improved running performance in the 6 min time trial test (1668 ± 139 m placebo vs. 1642 ± 158 m control, t = 2.49; p = 0.03; moderate ES = 0.69), while pacing, heart rate, RPE, and kinematic variables were similar between conditions (p > 0.05 in all cases). Minor side effects were reported. Beliefs of caffeine ingestion can improve running performance at speeds around maximal aerobic speed in recreationally trained runners without affecting pacing strategy so this "nutritional" strategy could be useful in competition scenarios. As a practical application, recreationally trained runners could improve ≈5 s in 1500 m or mile competitions.