Evaluation of Damage Progression in a Composite Material Hip Implant during Long-Term Multiaxial Fatigue

2009 ◽  
pp. 256-256-16 ◽  
Author(s):  
AJ Gavens ◽  
K Liao ◽  
GR Maharaj ◽  
RD Jamison ◽  
KL Reifsnider
Keyword(s):  
Composite Material ◽  
Multiaxial Fatigue ◽  
Hip Implant ◽  
Damage Progression

scholarly journals Comparative analysis of long-term organ damage in patients with systemic lupus erythematosus using belimumab versus standard therapy: a post hoc longitudinal study

2020 ◽  
Vol 7 (1) ◽  
pp. e000412
Author(s):  
Murray B Urowitz ◽  
Robert L Ohsfeldt ◽  
Ronald C Wielage ◽  
John J Dever ◽  
Mehdi Zakerifar ◽  
...  
Keyword(s):  
Propensity Score ◽  
Propensity Score Matching ◽  
Standard Therapy ◽  
Organ Damage ◽  
Systemic Lupus ◽  
Damage Progression ◽  
Damage Accrual ◽  
Post Hoc

ObjectiveLong-term extension (LTE) studies of belimumab in SLE do not include a comparator arm, preventing comparisons between belimumab plus standard therapy and standard therapy alone for organ damage accrual. Propensity score matching can be used to match belimumab-treated patients from LTE studies with standard therapy–treated patients from observational cohort studies. This analysis was designed to compare organ damage progression between treatment groups (belimumab plus standard therapy vs standard therapy alone) in patients with SLE with ≥5 years of follow-up, reproducing our previous study with more generalisable data.MethodsThis exploratory post hoc analysis used a heterogeneous population of US and non-US patients receiving monthly intravenous belimumab from pooled BLISS LTE trials (BEL112234/NCT00712933) and standard therapy–treated patients from the Toronto Lupus Cohort. Sixteen clinical variables were selected to calculate the propensity score.ResultsThe 592 LTE and 381 Toronto Lupus Cohort patients were highly dissimilar across the 16 variables; an adequately balanced sample of 181 LTE and 181 matched Toronto Lupus Cohort patients (mean bias=3.7%) was created using propensity score matching. Belimumab treatment was associated with a smaller increase in Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) over 5 years than standard therapy alone (mean treatment difference=–0.453 (95% CI –0.646 to –0.260); p<0.001). Patients treated with belimumab were 60% less likely to progress to a higher SDI score over any given year of follow-up, compared with standard therapy alone (HR (95% CI) 0.397 (0.275 to 0.572); p<0.001).ConclusionUsing propensity score matching, this highly heterogeneous sample was sufficiently matched to the Toronto Lupus Cohort, suggesting that patients treated with intravenous belimumab may have reduced organ damage progression versus standard therapy alone. This analysis of a large and diverse pooled SLE population was consistent with our previously published US-focused study.

scholarly journals Organ damage in patients treated with belimumab versus standard of care: a propensity score-matched comparative analysis

2019 ◽  
Vol 78 (3) ◽  
pp. 372-379 ◽  
Author(s):  
Murray B Urowitz ◽  
Robert L Ohsfeldt ◽  
Ronald C Wielage ◽  
Kari A Kelton ◽  
Yumi Asukai ◽  
...  
Keyword(s):  
Propensity Score ◽  
Lupus Erythematosus ◽  
Damage Index ◽  
Standard Of Care ◽  
Organ Damage ◽  
Systemic Lupus ◽  
American College Of Rheumatology ◽  
Damage Progression

ObjectivesThe study (206347) compared organ damage progression in patients with systemic lupus erythematosus (SLE) who received belimumab in the BLISS long-term extension (LTE) study with propensity score (PS)-matched patients treated with standard of care (SoC) from the Toronto Lupus Cohort (TLC).MethodsA systematic literature review identified 17 known predictors of organ damage to calculate a PS for each patient. Patients from the BLISS LTE and the TLC were PS matched posthoc 1:1 based on their PS (±calliper). The primary endpoint was difference in change in Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) score from baseline to 5 years.ResultsFor the 5- year analysis, of 567 (BLISS LTE n=195; TLC n=372) patients, 99 from each cohort were 1:1 PS matched. Change in SDI score at Year 5 was significantly lower for patients treated with belimumab compared with SoC (−0.434; 95% CI –0.667 to –0.201; p<0.001). For the time to organ damage progression analysis (≥1 year follow-up), the sample included 965 (BLISS LTE n=259; TLC n=706) patients, of whom 179 from each cohort were PS-matched. Patients receiving belimumab were 61% less likely to progress to a higher SDI score over any given year compared with patients treated with SoC (HR 0.391; 95% CI 0.253 to 0.605; p<0.001). Among the SDI score increases, the proportion of increases ≥2 was greater in the SoC group compared with the belimumab group.ConclusionsPS-matched patients receiving belimumab had significantly less organ damage progression compared with patients receiving SoC.

Graphene oxide in carbon nitride: from easily processed precursors to a composite material with enhanced photoelectrochemical activity and long-term stability

2019 ◽  
Vol 7 (19) ◽  
pp. 11718-11723 ◽  
Author(s):  
Guiming Peng ◽  
Jiani Qin ◽  
Michael Volokh ◽  
Chong Liu ◽  
Menny Shalom
Keyword(s):  
Composite Material ◽  
Graphene Oxide ◽  
Charge Separation ◽  
Carbon Nitride ◽  
Photoelectrochemical Activity ◽  
Term Stability ◽  
Long Term Stability ◽  
Transfer Properties

Herein we report a facile method to grow an ordered carbon nitride (CN) layer with improved charge separation and transfer properties under illumination.

scholarly journals The influence of accelerated aging on the physical and chemical properties of a composite material: a systematic overview

2021 ◽  
Vol 19 (4) ◽  
pp. 310-316
Author(s):  
S. M. Abdulkerimova ◽  
A. A. Kulikova ◽  
M. Yu. Dashtieva
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Artificial Aging ◽  
Chemical Properties ◽  
Accelerated Aging ◽  
Scientific Data ◽  
Dental Composite ◽  
Morphological Properties ◽  
Clinical Conditions

Relevance. Today, dental composite materials are very popular among dentists. The composite material is a filler in the form of particles of various sizes immersed in a polymer matrix. Polymer composites are used for direct filling of all groups of teeth and at different depths of the lesion. Composite materials have optimum mechanical, aesthetic and functional properties. They are simple and easy to use, provide long-term restoration service, and also have a wide price range. All these qualities allowed composite materials to firmly gain a foothold in the practice of dentists around the world. In this regard, clinicians and researchers are constantly trying to significantly improve their physical, mechanical, adaptive and aesthetic properties.Aim. Conduct a systematic assessment of the available scientific data on the effect of accelerated aging of the composite on its physicochemical properties.Materials and methods. In the course of a systematic review of the literature, a study was made of publications in electronic databases such as Google Scholar, PubMed, Research gate, Elibrary. The search results are formatted using the Prisma diagram.Results. Dental composites inevitably age over time and under the influence of environmental factors. To predict the long-term service life of composite restorations, scientists and clinicians are studying the aging behavior of the material. To simulate the clinical conditions of the oral cavity, various methods of artificial aging of dental composite materials have been developed.Conclusions. A study of scientific papers published over the past 10 years on the topic of artificial aging of dental composite materials has shown its unambiguous effect on the mechanical and morphological properties of polymers. The use of methods for simulating clinical conditions made it possible to reduce the study time and analyze the changes obtained.

scholarly journals Accelerated climatic testing of composite coatings on AMg3 aluminum alloy in salt spray medium

2020 ◽  
pp. 78-83
Author(s):  
В.С. ФИЛОНИНА ◽  
К.В. НАДАРАИА ◽  
А.С. ГНЕДЕНКОВ ◽  
И.М. ИМШИНЕЦКИЙ ◽  
Д.В. МАШТАЛЯР ◽  
...  
Keyword(s):  
Composite Material ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Composite Coatings ◽  
Salt Spray ◽  
Composite Polymer ◽  
Climatic Testing ◽  
Salt Fog ◽  
Positive Effect

Представлены результаты ускоренных климатических испытаний композиционных полимерсодержащих покрытий на сплаве алюминия АМг3. Выявлено положительное влияние импрегнированного в поры ПЭО-покрытия композиционного материала на смачиваемость и коррозионную стойкость исследуемых образцов в условиях долговременного воздействия соляного тумана. Наиболее высокую коррозионную стойкость продемонстрировали образцы с четырехкратным нанесением ультрадисперсного политетрафторэтилена. The results of accelerated climatic tests of composite polymer-containing coatings on the AMg3 aluminum alloy are presented in the paper. According to the results of the studies carried out, a positive effect of the penetrated composite material into the pores of a PEO-coating on the wettability and corrosion resistance of the test samples under conditions of long-term exposure to salt fog has been revealed. The highest corrosion resistance was demonstrated by samples with a fourfold (СС-4x) application of superdispersed polytetrafluoroethylene.

Dynamic Stability of Multi-Functional Composite Developed for Application in Permanent Way of Prague Underground

2018 ◽  
Vol 760 ◽  
pp. 147-151
Author(s):  
Karel Kolář ◽  
Jiří Litoš ◽  
Pavel Reiterman ◽  
Miroslav Petrtýl
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Dynamic Stability ◽  
Dynamic Loading ◽  
Rapid Evolution ◽  
Steel Fibers ◽  
Laboratory Model ◽  
Transportation Industry ◽  
Reference Mixture

There are described properties of hardening multi-functional silicate composite during its long-term dynamical loading in the paper. Studied composite was developed for special application in permanent way structure in Prague underground. Dynamic loading was carried out on the laboratory model, in which the composite was applied as a bench of the rail anchoring. Due to loading in early ages was also studied the option of steel fibers addition. Results obtained confirmed impressive potential for practical use during new tracks construction, and quick repairs as well, because of rapid evolution of mechanical properties and sufficient resistance to dynamic loading. Silicate composite with fibers addition had better mechanical properties, however significant improvement during dynamic loading was not recorded in comparison with the reference mixture without fibers. Generally, new composite material confirmed great potential for practical use in transportation industry.

scholarly journals Wheeled Robot Dedicated to the Evaluation of the Technical Condition of Large-Dimension Engineering Structures

Robotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 28
Author(s):  
Jarosław Domin ◽  
Marcin Górski ◽  
Ryszard Białecki ◽  
Jakub Zając ◽  
Krzysztof Grzyb ◽  
...  
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Technical Condition ◽  
Fiber Reinforced Polymer ◽  
Loading Capacity ◽  
Engineering Structures ◽  
Reinforced Polymer ◽  
Wheeled Robot

There are many reasons why engineering structures are at risk of losing their loading capacity during their long-term exploitation, which may lead to hazardous states. In such cases, structures must be strengthened. The most popular technique of strengthening is based on the use of composite materials—fiber-reinforced polymer (FRP) elements attached to the structure with the special resins. FRP elements are applied externally, often in hard to reach places, which makes it difficult to diagnose the durability and quality of such a connection. In this study, a combination of a modern thermographic method was proposed, which makes it possible to assess the degree of damage to the contact of the structure with the composite material along with the running platform (wheeled robot) equipped with a set of diagnostic sensors. The development potential of such a solution for subsequent projects was also indicated.

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