473 research outputs found
Unlined Length Effect on the Tunnel Face Stability and Collapse Mechanisms in c-ϕ Soils: A Numerical Study with Advanced Mesh Adaptive Strategies
This paper presents a stability study on the collapse mechanisms of a plane-strain tunnel face in c-ϕ soils using the upper bound finite element method with rigid translatory moving elements (UBFELA-RTME) and nonlinear programming technique. Practical considerations are given to the unlined length influence behind the tunnel face. An advanced mesh adaptive updating strategy is adopted, aiming to improve the computational efficiency, the accuracy of upper-bound solutions, as well as the produced collapse mechanisms. The unlined length influence on the face stability and collapse mechanism of the tunnel face are determined with various combinations of tunnel depth ratios, soil friction angles, and dilatancy angles. Using the UBFELA-RTME with the Davis’s approach and a mesh adapting strategy, the non-associated plasticity flow rule can be well approximated. The developed technique was validated against different numerical methods, and it is concluded that the tunnel face stability can be improved by increasing soil friction and dilatancy angles, and yet weakens as the unlined length increases where a mesh-liked collapse zone gradually appears on the tunnel vault top. It gradually evolves to a global collapse failure till the ground surface. The findings contribute to a better understanding of the ground surface failure under the unlined support length influence in tunnel construction
Determination of the motor unit behavior of lumbar erector spinae muscles through surface EMG decomposition technology in healthy female subjects
Introduction: The aims of this study were to determine the motor unit behavior of the erector spinae muscles and to assess whether differences exist between the dominant/non-dominant sides of the back muscles.
Methods: Nine healthy women, aged 21.7 years (±0.7), performed a back extension test. Surface electromyographic decomposition data were collected from both sides of the erector spinae and decomposed into individual motor unit action potential trains. The mean firing rate for each motor unit was calculated, and a regression analysis was performed against the corresponding recruitment thresholds.
Results: The mean firing rate ranged from 15.9 to 23.9 pulses per second (pps) and 15.8 to 20.6 pps on the dominant and non-dominant sides, respectively. However, the early motor unit potential s of the non-dominant lumbar erector spinae muscles were recruited at a lower firing rate.
Conclusions: This technique may further our understanding of individuals with back pain and other underlying neuromuscular diseases
Torque-angle-velocity relationships and muscle performance of professional and youth soccer players
Soccer matches consist of a variety of different activities, including repeated sprints. Time to attain velocity (TTAV), load range (LR) and the torque-angle-velocity relationship (TAV3D) represent an important measurement of muscle performance however there are few studies related. The aim of this study was to compare these outcomes between soccer players of different age category. Seventeen professional (PRO) and seventeen under-17 (U17) soccer players were assessed for concentric knee flexion/extension at 60, 120 and 300 °/s. For the extensor muscles, differences were found in favor of the U17 group for TTAV and LR outcomes at 120 °/s, however, the PRO group maintained higher torques in both movement directions in comparison to the U17 in TAV3D evaluation. These results suggest that muscle performance of the PRO group is more efficient than the U17 group
The Vehicle, Spring 1972
Vol. 14, No. 3
Table of Contents
HarvestAnne Bradypage 3
poemJann Briesacherpage 5
Monday MorningJohn Harthpage 6
cartoon montageV. Gene Myerspage 8
From Winter to Spring is 3 Years LongCathie Kayserpage 10
FascinationBettie Jane Williamspage 12
The Arithmetic ProblemJanice Forbuspage 12
The Three A.M. Summer Nightpage 13
AccidentMaude Dailypage 13
The DisciplinarianGeorge J. Bueningpage 14
Photography Credits
Jim Diaspage 3, 4, 5, 6, 7, 11, 12, 13, 14
CoverV. Gene Myershttps://thekeep.eiu.edu/vehicle/1027/thumbnail.jp
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Single-shot 3D coherent diffractive imaging of core-shell nanoparticles with elemental specificity.
We report 3D coherent diffractive imaging (CDI) of Au/Pd core-shell nanoparticles with 6.1 nm spatial resolution with elemental specificity. We measured single-shot diffraction patterns of the nanoparticles using intense x-ray free electron laser pulses. By exploiting the curvature of the Ewald sphere and the symmetry of the nanoparticle, we reconstructed the 3D electron density of 34 core-shell structures from these diffraction patterns. To extract 3D structural information beyond the diffraction signal, we implemented a super-resolution technique by taking advantage of CDI's quantitative reconstruction capabilities. We used high-resolution model fitting to determine the Au core size and the Pd shell thickness to be 65.0 ± 1.0 nm and 4.0 ± 0.5 nm, respectively. We also identified the 3D elemental distribution inside the nanoparticles with an accuracy of 3%. To further examine the model fitting procedure, we simulated noisy diffraction patterns from a Au/Pd core-shell model and a solid Au model and confirmed the validity of the method. We anticipate this super-resolution CDI method can be generally used for quantitative 3D imaging of symmetrical nanostructures with elemental specificity
Effectiveness of early compared with conservative rehabilitation for patients having rotator cuff repair surgery: an overview of systematic reviews
Aim/objective
The aim is to critically analyse and discuss the current literature and determine the effectiveness of ehabilitation for patients after surgical repair of rotator cuff tears for range of motion (ROM), pain, functional status and retear rates; in addition, an update of new literature is included.
Design
Overview of systematic reviews.
Data sources
A search was performed with no restrictions to date of publication and language in the following databases: EBSCO, AMED, CINAHL, SPORTDiscus, EMBASE, Cochrane, LILACS, MEDLINE, PEDro, Scielo, SCOPUS and Web of Knowledge. The PRISMA guideline was followed to develop this review and the R-AMSTAR tool was used for critical appraisal of included reviews.
Eligibility criteria
Only systematic reviews and randomised controlled trials (RCTs) comparing the effectiveness of early with conservative rehabilitation, after surgical repair of the rotator cuff, were included. Moreover, the studies should report ROM, pain, functional status and/or retears rates before and after 3–24 months of the surgery.
Results
10 systematic reviews and 11 RCTs were included for the final analysis. Conflicting results and conclusions were presented by the systematic reviews, the use of primary studies varied; also the methodological quality of the reviews was diverse. This updated review, with new meta-analysis, showed no difference for function, pain, ROM or retears ratio between early and conservative rehabilitation.
Summary/Conclusions
Early mobilisation may be beneficial, particularly for small and medium tears; however, more studies with higher quality are required, especially for patients with large tears who have been given less attention
Kinetoplastids:related protozoan pathogens, different diseases
Kinetoplastids are a group of flagellated protozoans that include the species Trypanosoma and Leishmania, which are human pathogens with devastating health and economic effects. The sequencing of the genomes of some of these species has highlighted their genetic relatedness and underlined differences in the diseases that they cause. As we discuss in this Review, steady progress using a combination of molecular, genetic, immunologic, and clinical approaches has substantially increased understanding of these pathogens and important aspects of the diseases that they cause. Consequently, the paths for developing additional measures to control these “neglected diseases” are becoming increasingly clear, and we believe that the opportunities for developing the drugs, diagnostics, vaccines, and other tools necessary to expand the armamentarium to combat these diseases have never been better
The Vehicle, Fall 1970
Vol. 13, No. 1
Table of Contents
A Thought Written in a Locked RoomJudy Huntpage 1
The Eggshell MoonWilliam Probeckpage 2
PoemBarb Parkerpage 3
4/5, May, 1970J. Michael Sainpage 5
A TreeRichard Stickannpage 6
both or noneMichelle Hallpage 6
The TrainSteve Sestinapage 8
Attempted DiscoveryDonald R. Johnsonpage 16
Island of SmokeVerna L. Jonespage 18
AwakeRobert Bladepage 19
PoemMary Klinkerpage 19
In ChurchMuriel Poolpage 21
PoemBarb Parkerpage 21
PoemMichelle Hallpage 22
Pod\u27nerVerna L. Jonespage 23
Rain and Other ThingsCarol Staniecpage 24
PoemAnn Graffpage 24
Examination of StudentdomMelvin Zaloudekpage 26
Women\u27s LiberationTonya Mortonpage 27
Morning Reflections on the Evening NewsPrudence Herberpage 29
Art and Photography Credits
Jim Diaspage 4
Mike Dorseypages 7, 20
David Griffithpages 8, 17, 25
Cover PhotographyMark McKinneyhttps://thekeep.eiu.edu/vehicle/1024/thumbnail.jp
Single-shot 3D coherent diffractive imaging of core-shell nanoparticles with elemental specificity
We report 3D coherent diffractive imaging (CDI) of Au/Pd core-shell nanoparticles with 6.1 nm spatial resolution with elemental specificity. We measured single-shot diffraction patterns of the nanoparticles using intense x-ray free electron laser pulses. By exploiting the curvature of the Ewald sphere and the symmetry of the nanoparticle, we reconstructed the 3D electron density of 34 core-shell structures from these diffraction patterns. To extract 3D structural information beyond the diffraction signal, we implemented a super-resolution technique by taking advantage of CDI’s quantitative reconstruction capabilities. We used high-resolution model fitting to determine the Au core size and the Pd shell thickness to be 65.0 ± 1.0 nm and 4.0 ± 0.5 nm, respectively. We also identified the 3D elemental distribution inside the nanoparticles with an accuracy of 3%. To further examine the model fitting procedure, we simulated noisy diffraction patterns from a Au/Pd core-shell model and a solid Au model and confirmed the validity of the method. We anticipate this super-resolution CDI method can be generally used for quantitative 3D imaging of symmetrical nanostructures with elemental specificity
Treatment effect modification due to comorbidity : Individual participant data meta-analyses of 120 randomised controlled trials
BACKGROUND: People with comorbidities are underrepresented in clinical trials. Empirical estimates of treatment effect modification by comorbidity are lacking, leading to uncertainty in treatment recommendations. We aimed to produce estimates of treatment effect modification by comorbidity using individual participant data (IPD). METHODS AND FINDINGS: We obtained IPD for 120 industry-sponsored phase 3/4 trials across 22 index conditions (n = 128,331). Trials had to be registered between 1990 and 2017 and have recruited ≥300 people. Included trials were multicentre and international. For each index condition, we analysed the outcome most frequently reported in the included trials. We performed a two-stage IPD meta-analysis to estimate modification of treatment effect by comorbidity. First, for each trial, we modelled the interaction between comorbidity and treatment arm adjusted for age and sex. Second, for each treatment within each index condition, we meta-analysed the comorbidity-treatment interaction terms from each trial. We estimated the effect of comorbidity measured in 3 ways: (i) the number of comorbidities (in addition to the index condition); (ii) presence or absence of the 6 commonest comorbid diseases for each index condition; and (iii) using continuous markers of underlying conditions (e.g., estimated glomerular filtration rate (eGFR)). Treatment effects were modelled on the usual scale for the type of outcome (absolute scale for numerical outcomes, relative scale for binary outcomes). Mean age in the trials ranged from 37.1 (allergic rhinitis trials) to 73.0 (dementia trials) and percentage of male participants range from 4.4% (osteoporosis trials) to 100% (benign prostatic hypertrophy trials). The percentage of participants with 3 or more comorbidities ranged from 2.3% (allergic rhinitis trials) to 57% (systemic lupus erythematosus trials). We found no evidence of modification of treatment efficacy by comorbidity, for any of the 3 measures of comorbidity. This was the case for 20 conditions for which the outcome variable was continuous (e.g., change in glycosylated haemoglobin in diabetes) and for 3 conditions in which the outcomes were discrete events (e.g., number of headaches in migraine). Although all were null, estimates of treatment effect modification were more precise in some cases (e.g., sodium-glucose co-transporter-2 (SGLT2) inhibitors for type 2 diabetes-interaction term for comorbidity count 0.004, 95% CI -0.01 to 0.02) while for others credible intervals were wide (e.g., corticosteroids for asthma-interaction term -0.22, 95% CI -1.07 to 0.54). The main limitation is that these trials were not designed or powered to assess variation in treatment effect by comorbidity, and relatively few trial participants had >3 comorbidities. CONCLUSIONS: Assessments of treatment effect modification rarely consider comorbidity. Our findings demonstrate that for trials included in this analysis, there was no empirical evidence of treatment effect modification by comorbidity. The standard assumption used in evidence syntheses is that efficacy is constant across subgroups, although this is often criticised. Our findings suggest that for modest levels of comorbidities, this assumption is reasonable. Thus, trial efficacy findings can be combined with data on natural history and competing risks to assess the likely overall benefit of treatments in the context of comorbidity
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