Automatic Quantification of Radiographic Wrist Joint Space Width of Patients With Rheumatoid Arthritis.

PubMed

Huo, Yinghe; Vincken, Koen L; van der Heijde, Desiree; de Hair, Maria J H; Lafeber, Floris P; Viergever, Max A

2017-11-01

Objective: Wrist joint space narrowing is a main radiographic outcome of rheumatoid arthritis (RA). Yet, automatic radiographic wrist joint space width (JSW) quantification for RA patients has not been widely investigated. The aim of this paper is to present an automatic method to quantify the JSW of three wrist joints that are least affected by bone overlapping and are frequently involved in RA. These joints are located around the scaphoid bone, viz. the multangular-navicular, capitate-navicular-lunate, and radiocarpal joints. Methods: The joint space around the scaphoid bone is detected by using consecutive searches of separate path segments, where each segment location aids in constraining the subsequent one. For joint margin delineation, first the boundary not affected by X-ray projection is extracted, followed by a backtrace process to obtain the actual joint margin. The accuracy of the quantified JSW is evaluated by comparison with the manually obtained ground truth. Results: Two of the 50 radiographs used for evaluation of the method did not yield a correct path through all three wrist joints. The delineated joint margins of the remaining 48 radiographs were used for JSW quantification. It was found that 90% of the joints had a JSW deviating less than 20% from the mean JSW of manual indications, with the mean JSW error less than 10%. Conclusion: The proposed method is able to automatically quantify the JSW of radiographic wrist joints reliably. The proposed method may aid clinical researchers to study the progression of wrist joint damage in RA studies. Objective: Wrist joint space narrowing is a main radiographic outcome of rheumatoid arthritis (RA). Yet, automatic radiographic wrist joint space width (JSW) quantification for RA patients has not been widely investigated. The aim of this paper is to present an automatic method to quantify the JSW of three wrist joints that are least affected by bone overlapping and are frequently involved in RA. These joints are located around the scaphoid bone, viz. the multangular-navicular, capitate-navicular-lunate, and radiocarpal joints. Methods: The joint space around the scaphoid bone is detected by using consecutive searches of separate path segments, where each segment location aids in constraining the subsequent one. For joint margin delineation, first the boundary not affected by X-ray projection is extracted, followed by a backtrace process to obtain the actual joint margin. The accuracy of the quantified JSW is evaluated by comparison with the manually obtained ground truth. Results: Two of the 50 radiographs used for evaluation of the method did not yield a correct path through all three wrist joints. The delineated joint margins of the remaining 48 radiographs were used for JSW quantification. It was found that 90% of the joints had a JSW deviating less than 20% from the mean JSW of manual indications, with the mean JSW error less than 10%. Conclusion: The proposed method is able to automatically quantify the JSW of radiographic wrist joints reliably. The proposed method may aid clinical researchers to study the progression of wrist joint damage in RA studies.

Radiographic changes and factors associated with subsequent progression of damage in weight-bearing joints of patients with rheumatoid arthritis under TNF-blocking therapies-three-year observational study.

PubMed

Matsushita, Isao; Motomura, Hiraku; Seki, Eiko; Kimura, Tomoatsu

2017-07-01

The long-term effects of tumor necrosis factor (TNF)-blocking therapies on weight-bearing joints in patients with rheumatoid arthritis (RA) have not been fully characterized. The purpose of this study was to assess the radiographic changes of weight-bearing joints in patients with RA during 3-year of TNF-blocking therapies and to identify factors related to the progression of joint damage. Changes in clinical variables and radiological findings in 243 weight-bearing joints (63 hips, 54 knees, 71 ankles, and 55 subtalar joints) in 38 consecutive patients were investigated during three years of treatment with TNF-blocking agents. Multivariate logistic regression analysis was used to identify risk factors for the progression of weight-bearing joint damage. Seventeen (14.5%) of proximal weight-bearing joints (hips and knees) showed apparent radiographic progression during three years of treatment, whereas none of the proximal weight-bearing joints showed radiographic evidence of improvement or repair. In contrast, distal weight-bearing joints (ankle and subtalar joints) displayed radiographic progression and improvement in 20 (15.9%) and 8 (6.3%) joints, respectively. Multivariate logistic analysis for proximal weight-bearing joints identified the baseline Larsen grade (p < 0.001, OR:24.85, 95%CI: 5.07-121.79) and disease activity at one year after treatment (p = 0.003, OR:3.34, 95%CI:1.50-7.46) as independent factors associated with the progression of joint damage. On the other hand, multivariate analysis for distal weight-bearing joints identified disease activity at one year after treatment (p < 0.001, OR:2.13, 95%CI:1.43-3.18) as an independent factor related to the progression of damage. Baseline Larsen grade was strongly associated with the progression of damage in the proximal weight-bearing joints. Disease activity after treatment was an independent factor for progression of damage in proximal and distal weight-bearing joints. Early treatment with TNF-blocking agents and tight control of disease activity are necessary to prevent the progression of damage of the weight-bearing joints.

Quantification of joint inflammation in rheumatoid arthritis by time-resolved diffuse optical spectroscopy and tracer kinetic modeling

NASA Astrophysics Data System (ADS)

Ioussoufovitch, Seva; Morrison, Laura B.; Lee, Ting-Yim; St. Lawrence, Keith; Diop, Mamadou

2015-03-01

Rheumatoid arthritis (RA) is characterized by chronic synovial inflammation, which can cause progressive joint damage and disability. Diffuse optical spectroscopy (DOS) and imaging have the potential to become potent monitoring tools for RA. We devised a method that combined time-resolved DOS and tracer kinetics modeling to rapidly and reliably quantify blood flow in the joint. Preliminary results obtained from two animals show that the technique can detect joint inflammation as early as 5 days after onset.

Micro-Energy Rates for Damage Tolerance and Durability of Composite Structures

NASA Technical Reports Server (NTRS)

Chamis, Christos C.; Minnetyan, Levon

2006-01-01

In this paper, the adhesive bond strength of lap-jointed graphite/aluminum composites is examined by computational simulation. Computed micro-stress level energy release rates are used to identify the damage mechanisms associated with the corresponding acoustic emission (AE) signals. Computed damage regions are similarly correlated with ultrasonically scanned damage regions. Results show that computational simulation can be used with suitable NDE methods for credible in-service monitoring of composites.

Resistance welding graphite-fiber composites

NASA Technical Reports Server (NTRS)

Lamoureux, R. T.

1980-01-01

High-strength joints are welded in seconds in carbon-reinfored thermoplastic beams. Resistance-welding electrode applies heat and pressure to joint and is spring-loaded to follow softening material to maintain contact; it also holds parts together for cooling and hardening. Both transverse and longitudinal configurations can be welded. Adhesive bonding and encapsulation are more time consuming methods and introduce additional material into joint, while ultrasonic heating can damage graphite fibers in composite.

The Characteristics of Fatigue Damage in the Fuselage Riveted Lap Splice Joint

NASA Technical Reports Server (NTRS)

Piascik, Robert S.; Willard, Scott A.

1997-01-01

An extensive data base has been developed to form the physical basis for new analytical methodology to predict the onset of widespread fatigue damage in the fuselage lap splice joint. The results of detailed destructive examinations have been cataloged to describe the physical nature of MSD in the lap splice joint. ne catalog includes a detailed description, e.g., crack initiation, growth rates, size, location, and fracture morphology, of fatigue damage in the fuselage lap splice joint structure. Detailed examinations were conducted on a lap splice joint panel removed from a full scale fuselage test article after completing a 60,000 cycle pressure test. The panel contained a four bay region that exhibited visible outer skin cracks and regions of crack link-up along the upper rivet row. Destructive examinations revealed undetected fatigue damage in the outer skin, inner skin, and tear strap regions. Outer skin fatigue cracks were found to initiate by fretting damage along the faying surface. The cracks grew along the faying surface to a length equivalent to two to three skin thicknesses before penetrating the outboard surface of the outer skin. Analysis of fracture surface marker bands produced during full scale testing revealed that all upper rivet row fatigue cracks contained in a dim bay region grow at similar rates; this important result suggests that fracture mechanics based methods can be used to predict the growth of outer skin fatigue cracks in lap splice structure. Results are presented showing the affects of MSD and out-of-plane pressure loads on outer skin crack link-up.

Shear sensing in bonded composites with cantilever beam microsensors and dual-plane digital image correlation

NASA Astrophysics Data System (ADS)

Baur, Jeffery W.; Slinker, Keith; Kondash, Corey

2017-04-01

Understanding the shear strain, viscoelastic response, and onset of damage within bonded composites is critical to their design, processing, and reliability. This presentation will discuss the multidisciplinary research conducted which led to the conception, development, and demonstration of two methods for measuring the shear within a bonded joint - dualplane digital image correlation (DIC) and a micro-cantilever shear sensor. The dual plane DIC method was developed to measure the strain field on opposing sides of a transparent single-lap joint in order to spatially quantify the joint shear strain. The sensor consists of a single glass fiber cantilever beam with a radially-grown forest of carbon nanotubes (CNTs) within a capillary pore. When the fiber is deflected, the internal radial CNT array is compressed against an electrode within the pore and the corresponding decrease in electrical resistance is correlated with the external loading. When this small, simple, and low-cost sensor was integrated within a composite bonded joint and cycled in tension, the onset of damage prior to joint failure was observed. In a second sample configuration, both the dual plane DIC and the hair sensor detected viscoplastic changes in the strain of the sample in response to continued loading.

Concept for a fast analysis method of the energy dissipation at mechanical joints

NASA Astrophysics Data System (ADS)

Wolf, Alexander; Brosius, Alexander

2017-10-01

When designing hybrid parts and structures one major challenge is the design, production and quality assessment of the joining points. While the polymeric composites themselves have excellent material properties, the necessary joints are often the weak link in assembled structures. This paper presents a method of measuring and analysing the energy dissipation at mechanical joining points of hybrid parts. A simplified model is applied based on the characteristic response to different excitation frequencies and amplitudes. The dissipation from damage is the result of relative moments between joining partners und damaged fibres within the composite, whereas the visco-elastic material behaviour causes the intrinsic dissipation. The ambition is to transfer these research findings to the characterisation of mechanical joints in order to quickly assess the general quality of the joint with this non-destructive testing method. The inherent challenge for realising this method is the correct interpretation of the measured energy dissipation and its attribution to either a bad joining point or intrinsic material properties. In this paper the authors present the concept for energy dissipation measurements at different joining points. By inverse analysis a simplified fast semi-analytical model will be developed that allows for a quick basic quality assessment of a given joining point.

Detection of fastener loosening in simple lap joint based on ultrasonic wavefield imaging

NASA Astrophysics Data System (ADS)

Gooda Sahib, M. I.; Leong, S. J.; Chia, C. C.; Mustapha, F.

2017-12-01

Joints in aero-mechanical structures are critical elements that ensure the structural integrity but they are prone to damages. Inspection of such joints that have no prior baseline data is really challenging but it can be possibly done using the Ultrasonic Propagation Imager (UPI). The feasibility of applying UPI for detection of loosened fastener is investigated in this study. A simple lap joint specimen made by connecting two pieces of 2.5mm thick SAE304 stainless steel plates using five M6 screws and nuts has been used in this study. All fasteners are tightened to 10Nm but one of them is completely loosened to simulate the damage. The wavefield data is processed into ultrasonic wavefield propagation video and a series of spectral amplitude images. The spectral images showed noticeable amplitude difference at the loosened fastener, hence confirmed the feasibility of using UPI for structural joints inspection. A simple contrast maximization method is also introduced to improve the result.

Computer-Based Radiographic Quantification of Joint Space Narrowing Progression Using Sequential Hand Radiographs: Validation Study in Rheumatoid Arthritis Patients from Multiple Institutions.

PubMed

Ichikawa, Shota; Kamishima, Tamotsu; Sutherland, Kenneth; Fukae, Jun; Katayama, Kou; Aoki, Yuko; Okubo, Takanobu; Okino, Taichi; Kaneda, Takahiko; Takagi, Satoshi; Tanimura, Kazuhide

2017-10-01

We have developed a refined computer-based method to detect joint space narrowing (JSN) progression with the joint space narrowing progression index (JSNPI) by superimposing sequential hand radiographs. The purpose of this study is to assess the validity of a computer-based method using images obtained from multiple institutions in rheumatoid arthritis (RA) patients. Sequential hand radiographs of 42 patients (37 females and 5 males) with RA from two institutions were analyzed by a computer-based method and visual scoring systems as a standard of reference. The JSNPI above the smallest detectable difference (SDD) defined JSN progression on the joint level. The sensitivity and specificity of the computer-based method for JSN progression was calculated using the SDD and a receiver operating characteristic (ROC) curve. Out of 314 metacarpophalangeal joints, 34 joints progressed based on the SDD, while 11 joints widened. Twenty-one joints progressed in the computer-based method, 11 joints in the scoring systems, and 13 joints in both methods. Based on the SDD, we found lower sensitivity and higher specificity with 54.2 and 92.8%, respectively. At the most discriminant cutoff point according to the ROC curve, the sensitivity and specificity was 70.8 and 81.7%, respectively. The proposed computer-based method provides quantitative measurement of JSN progression using sequential hand radiographs and may be a useful tool in follow-up assessment of joint damage in RA patients.

Crack Damage Parameters and Dilatancy of Artificially Jointed Granite Samples Under Triaxial Compression

NASA Astrophysics Data System (ADS)

Walton, G.; Alejano, L. R.; Arzua, J.; Markley, T.

2018-06-01

A database of post-peak triaxial test results was created for artificially jointed planes introduced in cylindrical compression samples of a Blanco Mera granite. Aside from examining the artificial jointing effect on major rock and rock mass parameters such as stiffness, peak strength and residual strength, other strength parameters related to brittle cracking and post-yield dilatancy were analyzed. Crack initiation and crack damage values for both the intact and artificially jointed samples were determined, and these damage envelopes were found to be notably impacted by the presence of jointing. The data suggest that with increased density of jointing, the samples transition from a combined matrix damage and joint slip yielding mechanism to yield dominated by joint slip. Additionally, post-yield dilation data were analyzed in the context of a mobilized dilation angle model, and the peak dilation angle was found to decrease significantly when there were joints in the samples. These dilatancy results are consistent with hypotheses in the literature on rock mass dilatancy.

Comparison of Tensile Damage Evolution in Ti6A14V Joints Between Laser Beam Welding and Gas Tungsten Arc Welding

NASA Astrophysics Data System (ADS)

Gao, Xiao-Long; Zhang, Lin-Jie; Liu, Jing; Zhang, Jian-Xun

2014-12-01

The present paper studied the evolution of tensile damage in joints welded using laser beam welding (LBW) and gas tungsten arc welding (TIG) under a uniaxial tensile load. The damage evolution in the LBW joints and TIG-welded joints was studied by using digital image correlation (DIC) technology and monitoring changes in Young's modulus during tensile testing. To study the mechanism of void nucleation and growth in the LBW joints and TIG-welded joints, test specimens with various amounts of plastic deformation were analyzed using a scanning electron microscope (SEM). Compared with TIG-welded joints, LBW-welded joints have a finer microstructure and higher microhardness in the fusion zone. The SEM analysis and DIC test results indicated that the critical strain of void nucleation was greater in the LBW-welded joints than in the TIG-welded joints, while the growth rate of voids was lower in the LBW-welded joints than in the TIG-welded joints. Thus, the damage ratio in the LBW joints was lower than that in the TIG-welded joints during tensile testing. This can be due to the coarser martensitic α' and the application of TC-1 welding rods in the TIG-welded joint.

Flaw Tolerance In Lap Shear Brazed Joints. Part 2

NASA Technical Reports Server (NTRS)

Wang, Len; Flom, Yury

2003-01-01

This paper presents results of the second part of an on-going effort to gain better understanding of defect tolerance in braze joints. In the first part of this three-part series, we mechanically tested and modeled the strength of the lap joints as a function of the overlap distance. A failure criterion was established based on the zone damage theory, which predicts the dependence of the lap joint shear strength on the overlap distance, based on the critical size of a finite damage zone or an overloaded region in the joint. In this second part of the study, we experimentally verified the applicability of the damage zone criterion on prediction of the shear strength of the lap joint and introduced controlled flaws into the lap joints. The purpose of the study was to evaluate the lap joint strength as a function of flaw size and its location through mechanical testing and nonlinear finite element analysis (FEA) employing damage zone criterion for definition of failure. The results obtained from the second part of the investigation confirmed that the failure of the ductile lap shear brazed joints occurs when the damage zone reaches approximately 10% of the overlap width. The same failure criterion was applicable to the lap joints containing flaws.

Modeling thermal and irradiation-induced swelling effects on the integrity of Ti3SiC2/SiC joints

NASA Astrophysics Data System (ADS)

Nguyen, Ba Nghiep; Henager, Charles H.; Kurtz, Richard J.

2017-11-01

Previously, results for CVD-SiC joined by a solid state displacement reaction to form a dual-phase SiC/MAX phase joint subsequently irradiated at 800 °C to 5 dpa indicated some cracking in the joint. This paper elucidates the cracking origin by developing a model that accounts for differential thermal expansion and irradiation-induced swelling between the substrate and joint materials by using a continuum damage mechanics approach with support from micromechanical modeling. Damage accumulation in joined specimens irradiated at four temperatures (300 °C, 400 °C, 500 °C and 800 °C) is analyzed. We assume the experimental irradiation dose is sufficient to cause saturation swelling in SiC. The analyses indicate that the SiC/MAX joint survives irradiation-induced swelling at all the irradiation temperatures considered. The joint experiences only minor damage when heated to and irradiated at 800 °C as well as cooling to room temperature. The prediction agrees with the experimental findings available for this case. However, the joint heated to 300 °C suffers severe damage during irradiation-induced swelling at this temperature, and additional damage after cooling to room temperature. Irradiation at 400 °C and subsequent cooling to room temperature produced similar damage to the irradiation 300 °C case, but to a lesser extent. The joint heated to 500 °C and irradiated at this temperature suffered only very minor damage, but further moderate damage occurred after cooling to room temperature.

Modeling thermal and irradiation-induced swelling effects on the integrity of Ti 3SiC 2/SiC joints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Ba Nghiep; Henager, Charles H.; Kurtz, Richard J.

Previously, results for CVD-SiC joined by a solid state displacement reaction to form a dual-phase SiC/MAX phase joint subsequently irradiated at 800 °C to 5 dpa indicated some cracking in the joint. Here, this paper elucidates the cracking origin by developing a model that accounts for differential thermal expansion and irradiation-induced swelling between the substrate and joint materials by using a continuum damage mechanics approach with support from micromechanical modeling. Damage accumulation in joined specimens irradiated at four temperatures (300 °C, 400 °C, 500 °C and 800 °C) is analyzed. We assume the experimental irradiation dose is sufficient to causemore » saturation swelling in SiC. The analyses indicate that the SiC/MAX joint survives irradiation-induced swelling at all the irradiation temperatures considered. The joint experiences only minor damage when heated to and irradiated at 800 °C as well as cooling to room temperature. The prediction agrees with the experimental findings available for this case. However, the joint heated to 300 °C suffers severe damage during irradiation-induced swelling at this temperature, and additional damage after cooling to room temperature. Irradiation at 400 °C and subsequent cooling to room temperature produced similar damage to the irradiation 300 °C case, but to a lesser extent. Finally, the joint heated to 500 °C and irradiated at this temperature suffered only very minor damage, but further moderate damage occurred after cooling to room temperature.« less

Modeling thermal and irradiation-induced swelling effects on the integrity of Ti 3SiC 2/SiC joints

DOE PAGES

Nguyen, Ba Nghiep; Henager, Charles H.; Kurtz, Richard J.

2017-09-08

Previously, results for CVD-SiC joined by a solid state displacement reaction to form a dual-phase SiC/MAX phase joint subsequently irradiated at 800 °C to 5 dpa indicated some cracking in the joint. Here, this paper elucidates the cracking origin by developing a model that accounts for differential thermal expansion and irradiation-induced swelling between the substrate and joint materials by using a continuum damage mechanics approach with support from micromechanical modeling. Damage accumulation in joined specimens irradiated at four temperatures (300 °C, 400 °C, 500 °C and 800 °C) is analyzed. We assume the experimental irradiation dose is sufficient to causemore » saturation swelling in SiC. The analyses indicate that the SiC/MAX joint survives irradiation-induced swelling at all the irradiation temperatures considered. The joint experiences only minor damage when heated to and irradiated at 800 °C as well as cooling to room temperature. The prediction agrees with the experimental findings available for this case. However, the joint heated to 300 °C suffers severe damage during irradiation-induced swelling at this temperature, and additional damage after cooling to room temperature. Irradiation at 400 °C and subsequent cooling to room temperature produced similar damage to the irradiation 300 °C case, but to a lesser extent. Finally, the joint heated to 500 °C and irradiated at this temperature suffered only very minor damage, but further moderate damage occurred after cooling to room temperature.« less

Recent Advances in Tissue Engineering Strategies for the Treatment of Joint Damage.

PubMed

Stephenson, Makeda K; Farris, Ashley L; Grayson, Warren L

2017-08-01

While the clinical potential of tissue engineering for treating joint damage has yet to be realized, research and commercialization efforts in the field are geared towards overcoming major obstacles to clinical translation, as well as towards achieving engineered grafts that recapitulate the unique structures, function, and physiology of the joint. In this review, we describe recent advances in technologies aimed at obtaining biomaterials, stem cells, and bioreactors that will enable the development of effective tissue-engineered treatments for repairing joint damage. 3D printing of scaffolds is aimed at improving the mechanical structure and microenvironment necessary for bone regeneration within a damaged joint. Advances in our understanding of stem cell biology and cell manufacturing processes are informing translational strategies for the therapeutic use of allogeneic and autologous cells. Finally, bioreactors used in combination with cells and biomaterials are promising strategies for generating large tissue grafts for repairing damaged tissues in pre-clinical models. Together, these advances along with ongoing research directions are making tissue engineering increasingly viable for the treatment of joint damage.

Adhesive Characterization and Progressive Damage Analysis of Bonded Composite Joints

NASA Technical Reports Server (NTRS)

Girolamo, Donato; Davila, Carlos G.; Leone, Frank A.; Lin, Shih-Yung

2014-01-01

The results of an experimental/numerical campaign aimed to develop progressive damage analysis (PDA) tools for predicting the strength of a composite bonded joint under tensile loads are presented. The PDA is based on continuum damage mechanics (CDM) to account for intralaminar damage, and cohesive laws to account for interlaminar and adhesive damage. The adhesive response is characterized using standard fracture specimens and digital image correlation (DIC). The displacement fields measured by DIC are used to calculate the J-integrals, from which the associated cohesive laws of the structural adhesive can be derived. A finite element model of a sandwich conventional splice joint (CSJ) under tensile loads was developed. The simulations indicate that the model is capable of predicting the interactions of damage modes that lead to the failure of the joint.

Progressive Damage Analysis of Bonded Composite Joints

NASA Technical Reports Server (NTRS)

Leone, Frank A., Jr.; Girolamo, Donato; Davila, Carlos G.

2012-01-01

The present work is related to the development and application of progressive damage modeling techniques to bonded joint technology. The joint designs studied in this work include a conventional composite splice joint and a NASA-patented durable redundant joint. Both designs involve honeycomb sandwich structures with carbon/epoxy facesheets joined using adhesively bonded doublers.Progressive damage modeling allows for the prediction of the initiation and evolution of damage within a structure. For structures that include multiple material systems, such as the joint designs under consideration, the number of potential failure mechanisms that must be accounted for drastically increases the complexity of the analyses. Potential failure mechanisms include fiber fracture, intraply matrix cracking, delamination, core crushing, adhesive failure, and their interactions. The bonded joints were modeled using highly parametric, explicitly solved finite element models, with damage modeling implemented via custom user-written subroutines. Each ply was discretely meshed using three-dimensional solid elements. Layers of cohesive elements were included between each ply to account for the possibility of delaminations and were used to model the adhesive layers forming the joint. Good correlation with experimental results was achieved both in terms of load-displacement history and the predicted failure mechanism(s).

Lamb wave propagation in Z-pin reinforced co-cured composite pi-joints

NASA Astrophysics Data System (ADS)

Swenson, Eric D.; Soni, Som R.; Kapoor, Hitesh

2010-04-01

This paper presents an initial study on Lamb wave propagation characteristics in z-pin reinforced, co-cured composite pi-joints for the purposes of structural health monitoring (SHM). Pi-joint test articles were designed and created to replicate a co-cured, all composite skin-spar joint found within a typical aircraft wing structure. Because pi-joints exhibit various complex damage modes, formal studies are required if SHM systems are to be developed to monitor these types of joints for potential damage. Experiments were conducted on a undamaged (healthy) and damaged test articles where Lamb waves were excited using one lead zirconate titanate (PZT) transducer. A three-dimensional (3D) scanning laser Doppler vibrometer (LDV) was used to collect high-density scans of both the in-plane and out-of-plane velocity measurements. In the damaged test article, where delamination, matrix cracking, and fiber breakage can clearly be seen, changes in both the fundamental antisymmetric A0 and symmetric S0 Lamb wave modes are apparent. In both test articles, the effects of narrow geometry, discontinuity due to the attachment of the web, and thickness has detectable effects on Lamb wave propagation. From the comparisons between Lamb waves propagating through the undamaged and damaged test articles, it is clear that damage can be detected using Lamb waves in z-pin reinforced, co-cured composite pi-joints for this case of extensive damage.

Lamb Wave Damage Quantification Using GA-Based LS-SVM.

PubMed

Sun, Fuqiang; Wang, Ning; He, Jingjing; Guan, Xuefei; Yang, Jinsong

2017-06-12

Lamb waves have been reported to be an efficient tool for non-destructive evaluations (NDE) for various application scenarios. However, accurate and reliable damage quantification using the Lamb wave method is still a practical challenge, due to the complex underlying mechanism of Lamb wave propagation and damage detection. This paper presents a Lamb wave damage quantification method using a least square support vector machine (LS-SVM) and a genetic algorithm (GA). Three damage sensitive features, namely, normalized amplitude, phase change, and correlation coefficient, were proposed to describe changes of Lamb wave characteristics caused by damage. In view of commonly used data-driven methods, the GA-based LS-SVM model using the proposed three damage sensitive features was implemented to evaluate the crack size. The GA method was adopted to optimize the model parameters. The results of GA-based LS-SVM were validated using coupon test data and lap joint component test data with naturally developed fatigue cracks. Cases of different loading and manufacturer were also included to further verify the robustness of the proposed method for crack quantification.

Lamb Wave Damage Quantification Using GA-Based LS-SVM

PubMed Central

Sun, Fuqiang; Wang, Ning; He, Jingjing; Guan, Xuefei; Yang, Jinsong

2017-01-01

Lamb waves have been reported to be an efficient tool for non-destructive evaluations (NDE) for various application scenarios. However, accurate and reliable damage quantification using the Lamb wave method is still a practical challenge, due to the complex underlying mechanism of Lamb wave propagation and damage detection. This paper presents a Lamb wave damage quantification method using a least square support vector machine (LS-SVM) and a genetic algorithm (GA). Three damage sensitive features, namely, normalized amplitude, phase change, and correlation coefficient, were proposed to describe changes of Lamb wave characteristics caused by damage. In view of commonly used data-driven methods, the GA-based LS-SVM model using the proposed three damage sensitive features was implemented to evaluate the crack size. The GA method was adopted to optimize the model parameters. The results of GA-based LS-SVM were validated using coupon test data and lap joint component test data with naturally developed fatigue cracks. Cases of different loading and manufacturer were also included to further verify the robustness of the proposed method for crack quantification. PMID:28773003

Fully automated joint space width measurement and digital X-ray radiogrammetry in early RA.

PubMed

Platten, Michael; Kisten, Yogan; Kälvesten, Johan; Arnaud, Laurent; Forslind, Kristina; van Vollenhoven, Ronald

2017-01-01

To study fully automated digital joint space width (JSW) and bone mineral density (BMD) in relation to a conventional radiographic scoring method in early rheumatoid arthritis (eRA). Radiographs scored by the modified Sharp van der Heijde score (SHS) in patients with eRA were acquired from the SWEdish FarmacOTherapy study. Fully automated JSW measurements of bilateral metacarpals 2, 3 and 4 were compared with the joint space narrowing (JSN) score in SHS. Multilevel mixed model statistics were applied to calculate the significance of the association between ΔJSW and ΔBMD over 1 year, and the JSW differences between damaged and undamaged joints as evaluated by the JSN. Based on 576 joints of 96 patients with eRA, a significant reduction from baseline to 1 year was observed in the JSW from 1.69 (±0.19) mm to 1.66 (±0.19) mm (p<0.01), and BMD from 0.583 (±0.068) g/cm 2 to 0.566 (±0.074) g/cm 2 (p<0.01). A significant positive association was observed between ΔJSW and ΔBMD over 1 year (p<0.0001). On an individual joint level, JSWs of undamaged (JSN=0) joints were wider than damaged (JSN>0) joints: 1.68 mm (95% CI 1.70 to 1.67) vs 1.54 mm (95% CI 1.63 to 1.46). Similarly the unadjusted multilevel model showed significant differences in JSW between undamaged (1.68 mm (95% CI 1.72 to 1.64)) and damaged joints (1.63 mm (95% CI 1.68 to 1.58)) (p=0.0048). This difference remained significant in the adjusted model: 1.66 mm (95% CI 1.70 to 1.61) vs 1.62 mm (95% CI 1.68 to 1.56) (p=0.042). To measure the JSW with this fully automated digital tool may be useful as a quick and observer-independent application for evaluating cartilage damage in eRA. NCT00764725.

Detection of damage in welded structure using experimental modal data

NASA Astrophysics Data System (ADS)

Abu Husain, N.; Ouyang, H.

2011-07-01

A typical automotive structure could contain thousands of spot weld joints that contribute significantly to the vehicle's structural stiffness and dynamic characteristics. However, some of these joints may be imperfect or even absent during the manufacturing process and they are also highly susceptible to damage due to operational and environmental conditions during the vehicle lifetime. Therefore, early detection and estimation of damage are important so necessary actions can be taken to avoid further problems. Changes in physical parameters due to existence of damage in a structure often leads to alteration of vibration modes; thus demonstrating the dependency between the vibration characteristics and the physical properties of structures. A sensitivity-based model updating method, performed using a combination of MATLAB and NASTRAN, has been selected for the purpose of this work. The updating procedure is regarded as parameter identification which aims to bring the numerical prediction to be as closely as possible to the measured natural frequencies and mode shapes data of the damaged structure in order to identify the damage parameters (characterised by the reductions in the Young's modulus of the weld patches to indicate the loss of material/stiffness at the damage region).

Progressive Damage Modeling of Durable Bonded Joint Technology

NASA Technical Reports Server (NTRS)

Leone, Frank A.; Davila, Carlos G.; Lin, Shih-Yung; Smeltzer, Stan; Girolamo, Donato; Ghose, Sayata; Guzman, Juan C.; McCarville, Duglas A.

2013-01-01

The development of durable bonded joint technology for assembling composite structures for launch vehicles is being pursued for the U.S. Space Launch System. The present work is related to the development and application of progressive damage modeling techniques to bonded joint technology applicable to a wide range of sandwich structures for a Heavy Lift Launch Vehicle. The joint designs studied in this work include a conventional composite splice joint and a NASA-patented Durable Redundant Joint. Both designs involve a honeycomb sandwich with carbon/epoxy facesheets joined with adhesively bonded doublers. Progressive damage modeling allows for the prediction of the initiation and evolution of damage. For structures that include multiple materials, the number of potential failure mechanisms that must be considered increases the complexity of the analyses. Potential failure mechanisms include fiber fracture, matrix cracking, delamination, core crushing, adhesive failure, and their interactions. The joints were modeled using Abaqus parametric finite element models, in which damage was modeled with user-written subroutines. Each ply was meshed discretely, and layers of cohesive elements were used to account for delaminations and to model the adhesive layers. Good correlation with experimental results was achieved both in terms of load-displacement history and predicted failure mechanisms.

Cohesive Laws and Progressive Damage Analysis of Composite Bonded Joints, a Combined Numerical/Experimental Approach

NASA Technical Reports Server (NTRS)

Girolamo, Donato; Davila, Carlos G.; Leone, Frank A.; Lin, Shih-Yung

2015-01-01

The results of an experimental/numerical campaign aimed to develop progressive damage analysis (PDA) tools for predicting the strength of a composite bonded joint under tensile loads are presented. The PDA is based on continuum damage mechanics (CDM) to account for intralaminar damage, and cohesive laws to account for interlaminar and adhesive damage. The adhesive response is characterized using standard fracture specimens and digital image correlation (DIC). The displacement fields measured by DIC are used to calculate the J-integrals, from which the associated cohesive laws of the structural adhesive can be derived. A finite element model of a sandwich conventional splice joint (CSJ) under tensile loads was developed. The simulations, in agreement with experimental tests, indicate that the model is capable of predicting the interactions of damage modes that lead to the failure of the joint.

Whole-body MRI assessment of disease activity and structural damage in rheumatoid arthritis: first step towards an MRI joint count.

PubMed

Axelsen, Mette Bjørndal; Eshed, Iris; Duer-Jensen, Anne; Møller, Jakob M; Pedersen, Susanne Juhl; Østergaard, Mikkel

2014-05-01

The aim of this study was to investigate the ability of whole-body MRI (WBMRI) to visualize inflammation [synovitis, bone marrow oedema (BME) and enthesitis] and structural damage in patients with RA. The 3T WBMR images were acquired in a head-to-toe scan in 20 patients with RA and at least one swollen or tender joint. Short Tau Inversion Recovery and pre- and post-contrast T1-weighted images were evaluated for readability and the presence/absence of inflammation (synovitis, BME and enthesitis) and structural damage (erosions and fat infiltrations) in 76 peripheral joints, 30 entheseal sites and in the spine. The readability was >70% for all individual joints, except for the most peripheral joints of the hands and feet. Synovitis was most frequent in the wrist, first tarsometatarsal, first CMC joints and glenohumeral joints (67-61%); BME in the wrist, CMC, acromioclavicular and glenohumeral joints (45-35%) and erosions in the wrist, MTP and CMC joints (19-16%). Enthesitis at ≥ 1 site was registered in 16 patients. BME was frequently seen in the cervical (20%) but not the thoracic and lumbar spine, while fat infiltrations and erosions were rare. The intrareader agreement was high (85-100%) for all pathologies. The agreement between WBMRI and clinical findings was low. Peripheral and axial inflammation and structural damage at joints and entheses was frequently identified by WBMRI, and more frequently than by clinical examination. WBMRI is a promising tool for evaluation of the total inflammatory load of inflammation (an MRI joint count) and structural damage in RA patients.

Fatigue damage behavior of a surface-mount electronic package under different cyclic applied loads

NASA Astrophysics Data System (ADS)

Ren, Huai-Hui; Wang, Xi-Shu

2014-04-01

This paper studies and compares the effects of pull-pull and 3-point bending cyclic loadings on the mechanical fatigue damage behaviors of a solder joint in a surface-mount electronic package. The comparisons are based on experimental investigations using scanning electron microscopy (SEM) in-situ technology and nonlinear finite element modeling, respectively. The compared results indicate that there are different threshold levels of plastic strain for the initial damage of solder joints under two cyclic applied loads; meanwhile, fatigue crack initiation occurs at different locations, and the accumulation of equivalent plastic strain determines the trend and direction of fatigue crack propagation. In addition, simulation results of the fatigue damage process of solder joints considering a constitutive model of damage initiation criteria for ductile materials and damage evolution based on accumulating inelastic hysteresis energy are identical to the experimental results. The actual fatigue life of the solder joint is almost the same and demonstrates that the FE modeling used in this study can provide an accurate prediction of solder joint fatigue failure.

Analysis of Network Vulnerability Under Joint Node and Link Attacks

NASA Astrophysics Data System (ADS)

Li, Yongcheng; Liu, Shumei; Yu, Yao; Cao, Ting

2018-03-01

The security problem of computer network system is becoming more and more serious. The fundamental reason is that there are security vulnerabilities in the network system. Therefore, it’s very important to identify and reduce or eliminate these vulnerabilities before they are attacked. In this paper, we are interested in joint node and link attacks and propose a vulnerability evaluation method based on the overall connectivity of the network to defense this attack. Especially, we analyze the attack cost problem from the attackers’ perspective. The purpose is to find the set of least costs for joint links and nodes, and their deletion will lead to serious network connection damage. The simulation results show that the vulnerable elements obtained from the proposed method are more suitable for the attacking idea of the malicious persons in joint node and link attack. It is easy to find that the proposed method has more realistic protection significance.

A dual-phase microstructural approach to damage and fracture of Ti3SiC2/SiC joints

NASA Astrophysics Data System (ADS)

Nguyen, Ba Nghiep; Henager, Charles H.; Kurtz, Richard J.

2018-02-01

The microcracking mechanisms responsible for Ti3SiC2/SiC joint damage observed at the macroscopic scale after neutron irradiation experiments are investigated in detail. A dual-phase microstructural approach to damage and fracture of Ti3SiC2/SiC joints is developed that uses a finely discretized two-phase domain based on a digital image of an actual microstructure involving embedded Ti3SiC2 and SiC phases. The behaviors of SiC and Ti3SiC2 in the domain are described by the continuum damage mechanics (CDM) model reported in Nguyen et al., J. Nucl. Mater., 2017, 495:504-515. This CDM model describes microcracking damage in brittle ceramics caused by thermomechanical loading and irradiation-induced swelling. The dual-phase microstructural model is applied to predict the microcracking mechanisms occurring in a typical Ti3SiC2/SiC joint subjected to heating to 800 °C followed by irradiation-induced swelling at this temperature and cooling to room temperature after the applied swelling has reached the maximum swelling levels observed in the experiments for SiC and Ti3SiC2. The model predicts minor damage of the joint after heating but significant microcracking in the SiC phase and along the boundaries between SiC and Ti3SiC2 as well as along the bonding joint during irradiation-induced swelling and cooling to room temperature. These predictions qualitatively agree with the limited experimental observations of joint damage at this irradiation temperature.

Seismic damage analysis of the outlet piers of arch dams using the finite element sub-model method

NASA Astrophysics Data System (ADS)

Song, Liangfeng; Wu, Mingxin; Wang, Jinting; Xu, Yanjie

2016-09-01

This study aims to analyze seismic damage of reinforced outlet piers of arch dams by the nonlinear finite element (FE) sub-model method. First, the dam-foundation system is modeled and analyzed, in which the effects of infinite foundation, contraction joints, and nonlinear concrete are taken into account. The detailed structures of the outlet pier are then simulated with a refined FE model in the sub-model analysis. In this way the damage mechanism of the plain (unreinforced) outlet pier is analyzed, and the effects of two reinforcement measures (i.e., post-tensioned anchor cables and reinforcing bar) on the dynamic damage to the outlet pier are investigated comprehensively. Results show that the plain pier is damaged severely by strong earthquakes while implementation of post-tensioned anchor cables strengthens the pier effectively. In addition, radiation damping strongly alleviates seismic damage to the piers.

Fatigue damage assessment of high-usage in-service aircraft fuselage structure

NASA Astrophysics Data System (ADS)

Mosinyi, Bao Rasebolai

As the commercial and military aircraft fleets continue to age, there is a growing concern that multiple-site damage (MSD) can compromise structural integrity. Multiple site damage is the simultaneous occurrence of many small cracks at independent structural locations, and is the natural result of fatigue, corrosion, fretting and other possible damage mechanisms. These MSD cracks may linkup and form a fatigue lead crack of critical length. The presence of MSD also reduces the structure's ability to withstand longer cracks. The objective of the current study is to assess, both experimentally and analytically, MSD formation and growth in the lap joint of curved panels removed from a retired aircraft. A Boeing 727-232 airplane owned and operated by Delta Air Lines, and retired at its design service goal, was selected for the study. Two panels removed from the left-hand side of the fuselage crown, near stringer 4L, were subjected to extended fatigue testing using the Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility located at the Federal Aviation Administration (FAA) William J. Hughes Technical Center. The state of MSD was continuously assessed using several nondestructive inspection (NDI) methods. Damage to the load attachment points of the first panel resulted in termination of the fatigue test at 43,500 fatigue cycles, before cracks had developed in the lap joint. The fatigue test for the second panel was initially conducted under simulated in-service loading conditions for 120,000 cycles, and no cracks were detected in the skin of the panel test section. Artificial damage was then introduced into the panel at selected rivets in the critical (lower) rivet row, and the fatigue loads were increased. Visually detectable crack growth from the artificial notches was first seen after 133,000 cycles. The resulting lead crack grew along the lower rivet row, eventually forming an 11.8" long unstable crack after 141,771 cycles, at which point the test was terminated. Posttest fractograpic examinations of the crack surfaces were conducted, revealing the presence of subsurface MSD at the critical rivet row of the lap joint. Special attention was also given to the stringer clips that attach the fuselage frames to the stringers, since they also experienced cracking during the fatigue tests. The performance of the different conventional and emerging NDI methods was also assessed, and some of the emerging NDI methods were quite effective in detecting and measuring the length of subsurface cracks. Delta Air Lines conducted a separate destructive investigation on the state of damage along the right-hand side of the fuselage, near stringer 4R. A comparison of these two studies showed that the lap joint on the left hand-side of the aircraft, along stringer 4L, had better fatigue life than the one on the opposite side, along stringer 4R. The cause of the difference in fatigue life was investigated by close examination of the rivet installation qualities, and was found to be a result of better rivet installation along the lap joint at stringer 4L. Finite element models for both the skin and substructures of the panels were developed and geometrically nonlinear finite element analyses were conducted to verify the loading conditions and to determine near-field parameters governing MSD initiation and growth. Fatigue crack growth predictions based on the NASGRO equation were in good agreement with the experimental crack growth data for through-the-thickness cracks. For subsurface cracks, simulation of crack growth was found to correlate better with fractography data when an empirical crack growth model was used. The results of the study contribute to the understanding of the initiation and growth of MSD in the inner skin layer of a lap joint, and provide valuable data for the evaluation and validation of analytical methodologies to predict MSD initiation and growth and a better understanding on the effect of manufacturing quality on damage accumulation along the lap joint.

Segmentation of hand radiographs using fast marching methods

NASA Astrophysics Data System (ADS)

Chen, Hong; Novak, Carol L.

2006-03-01

Rheumatoid Arthritis is one of the most common chronic diseases. Joint space width in hand radiographs is evaluated to assess joint damage in order to monitor progression of disease and response to treatment. Manual measurement of joint space width is time-consuming and highly prone to inter- and intra-observer variation. We propose a method for automatic extraction of finger bone boundaries using fast marching methods for quantitative evaluation of joint space width. The proposed algorithm includes two stages: location of hand joints followed by extraction of bone boundaries. By setting the propagation speed of the wave front as a function of image intensity values, the fast marching algorithm extracts the skeleton of the hands, in which each branch corresponds to a finger. The finger joint locations are then determined by using the image gradients along the skeletal branches. In order to extract bone boundaries at joints, the gradient magnitudes are utilized for setting the propagation speed, and the gradient phases are used for discriminating the boundaries of adjacent bones. The bone boundaries are detected by searching for the fastest paths from one side of each joint to the other side. Finally, joint space width is computed based on the extracted upper and lower bone boundaries. The algorithm was evaluated on a test set of 8 two-hand radiographs, including images from healthy patients and from patients suffering from arthritis, gout and psoriasis. Using our method, 97% of 208 joints were accurately located and 89% of 416 bone boundaries were correctly extracted.

Preliminayr Study on Diffraction Enhanced Radiographic Imaging for a Canine Model of Cartilage Damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muehleman,C.; Li, J.; Zhong, Z.

2006-01-01

Objective: To demonstrate the ability of a novel radiographic technique, Diffraction Enhanced Radiographic Imaging (DEI), to render high contrast images of canine knee joints for identification of cartilage lesions in situ. Methods: DEI was carried out at the X-15A beamline at Brookhaven National Laboratory on intact canine knee joints with varying levels of cartilage damage. Two independent observers graded the DE images for lesions and these grades were correlated to the gross morphological grade. Results: The correlation of gross visual grades with DEI grades for the 18 canine knee joints as determined by observer 1 (r2=0.8856, P=0.001) and observer 2more » (r2=0.8818, P=0.001) was high. The overall weighted ? value for inter-observer agreement was 0.93, thus considered high agreement. Conclusion: The present study is the first study for the efficacy of DEI for cartilage lesions in an animal joint, from very early signs through erosion down to subchondral bone, representing the spectrum of cartilage changes occurring in human osteoarthritis (OA). Here we show that DEI allows the visualization of cartilage lesions in intact canine knee joints with good accuracy. Hence, DEI may be applicable for following joint degeneration in animal models of OA.« less

Total-Body Irradiation Produces Late Degenerative Joint Damage in Rats

PubMed Central

Hutchinson, Ian D.; Olson, John; Lindburg, Carl A.; Payne, Valerie; Collins, Boyce; Smith, Thomas L.; Munley, Michael T.; Wheeler, Kenneth T.; Willey, Jeffrey S.

2014-01-01

Purpose Premature musculoskeletal joint failure is a major source of morbidity among childhood cancer survivors. Radiation effects on synovial joint tissues of the skeleton are poorly understood. Our goal was to assess long-term changes in the knee joint from skeletally mature rats that received total-body irradiation while skeletal growth was ongoing. Materials and Methods 14 week-old rats were irradiated with 1, 3 or 7 Gy total-body doses of 18 MV x-rays. At 53 weeks of age, structural and compositional changes in knee joint tissues (articular cartilage, subchondral bone, and trabecular bone) were characterized using 7T MRI, nanocomputed tomography (nanoCT), microcomputed tomography (microCT), and histology. Results T2 relaxation times of the articular cartilage were lower after exposure to all doses. Likewise, calcifications were observed in the articular cartilage. Trabecular bone microarchitecture was compromised in the tibial metaphysis at 7 Gy. Mild to moderate cartilage erosion was scored in the 3 and 7 Gy rats. Conclusions Late degenerative changes in articular cartilage and bone were observed after total body irradiation in adult rats exposed prior to skeletal maturity. 7T MRI, microCT, nanoCT, and histology identified potential prognostic indicators of late radiation-induced joint damage. PMID:24885745

A dual-phase microstructural approach to damage and fracture of Ti 3SiC 2/SiC joints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Ba Nghiep; Henager, Charles H.; Kurtz, Richard J.

We investigate the microcracking mechanisms responsible for Ti 3SiC 2/SiC joint damage observed at the macroscopic scale after neutron irradiation experiments in detail. A dual-phase microstructural approach to damage and fracture of Ti 3SiC 2/SiC joints is developed that uses a finely discretized two-phase domain based on a digital image of an actual microstructure involving embedded Ti 3SiC 2 and SiC phases. The behaviors of SiC and Ti 3SiC 2 in the domain are described by the continuum damage mechanics (CDM) model reported in Nguyen et al., J. Nucl. Mater., 2017, 495:504–515. This CDM model describes microcracking damage in brittlemore » ceramics caused by thermomechanical loading and irradiation-induced swelling. The dual-phase microstructural model is applied to predict the microcracking mechanisms occurring in a typical Ti 3SiC 2/SiC joint subjected to heating to 800 °C followed by irradiation-induced swelling at this temperature and cooling to room temperature after the applied swelling has reached the maximum swelling levels observed in the experiments for SiC and Ti 3SiC 2. The model predicts minor damage of the joint after heating but significant microcracking in the SiC phase and along the boundaries between SiC and Ti 3SiC 2 as well as along the bonding joint during irradiation-induced swelling and cooling to room temperature. Our predictions qualitatively agree with the limited experimental observations of joint damage at this irradiation temperature.« less

Swollen joint count in psoriatic arthritis is associated with progressive radiological damage in hands and feet.

PubMed

Simon, P; Pfoehler, C; Bergner, R; Schreiber, M; Pfreundschuh, M; Assmann, G

2012-01-01

Psoriatic arthritis (PsA) may progress to joint damage. Determining clinical predictors of joint damage assessed by radiography is important. The aim of this study was to determine clinical factors as possible predictors for radiological damage in hands and feet of PsA patients with a 12-month follow-up. We conducted a retrospective study on 53 PsA patients who were taking disease-modifying anti-rheumatic drugs (DMARDs) and/or tumour necrosis factor (TNF)-alpha-blockers at a fixed dosage. The patients were observed in 118 follow-up visits (intervals of 12 months ± 3 months), according to a clinical and radiological protocol which included the documentation of the number of swollen and tender joints in hands and feet, the applied therapy, psoriasis, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and global health assessment. Outcome was defined as radiographic damage of hands and feet (Ratingen score). For the statistical analysis the Chi-Square test for 2x2 crosstables (with Fisher's correction, as required) was used. Progressive radiological damage was more frequent among patients with an increasing swollen joint count (8 of 26 visits; 30.8%) than among those with a stable or decreased number of swollen joints (5 of 89 visits; 5.6%; p=0.001). The analysis of the patients stratified into the different treatment modalities resulted in a significant higher rate of radiological progress (20.8%) in patients on DMARD therapy compared with TNF-alpha blocking agents (0%) (p=0.009). During a 12-month follow-up of PsA patients, an increasing number of swollen joints heralds progression of radiological damage. TNF-alpha-blocker therapy appears to be superior to DMARDs in the protection from radiological progress.

A dual-phase microstructural approach to damage and fracture of Ti 3SiC 2/SiC joints

DOE PAGES

Nguyen, Ba Nghiep; Henager, Charles H.; Kurtz, Richard J.

2017-12-05

We investigate the microcracking mechanisms responsible for Ti 3SiC 2/SiC joint damage observed at the macroscopic scale after neutron irradiation experiments in detail. A dual-phase microstructural approach to damage and fracture of Ti 3SiC 2/SiC joints is developed that uses a finely discretized two-phase domain based on a digital image of an actual microstructure involving embedded Ti 3SiC 2 and SiC phases. The behaviors of SiC and Ti 3SiC 2 in the domain are described by the continuum damage mechanics (CDM) model reported in Nguyen et al., J. Nucl. Mater., 2017, 495:504–515. This CDM model describes microcracking damage in brittlemore » ceramics caused by thermomechanical loading and irradiation-induced swelling. The dual-phase microstructural model is applied to predict the microcracking mechanisms occurring in a typical Ti 3SiC 2/SiC joint subjected to heating to 800 °C followed by irradiation-induced swelling at this temperature and cooling to room temperature after the applied swelling has reached the maximum swelling levels observed in the experiments for SiC and Ti 3SiC 2. The model predicts minor damage of the joint after heating but significant microcracking in the SiC phase and along the boundaries between SiC and Ti 3SiC 2 as well as along the bonding joint during irradiation-induced swelling and cooling to room temperature. Our predictions qualitatively agree with the limited experimental observations of joint damage at this irradiation temperature.« less

Clinical synovitis in a particular joint is associated with progression of erosions and joint space narrowing in that same joint, but not in patients initially treated with infliximab.

PubMed

Klarenbeek, N B; Güler-Yüksel, M; van der Heijde, D M F M; Hulsmans, H M J; Kerstens, P J S M; Molenaar, T H E; de Sonnaville, P B J; Huizinga, T W J; Dijkmans, B A C; Allaart, C F

2010-12-01

To assess the relationship between joint tenderness, swelling and joint damage progression in individual joints and to evaluate the influence of treatment on these relationships. First-year data of the Behandel Strategieën (BeSt) study were used, in which patients recently diagnosed as having rheumatoid arthritis (RA) were randomly assigned into four different treatment strategies. Baseline and 1-year x-rays of the hands and feet were assessed using the Sharp-van der Heijde score (SHS). With generalised estimating equations, 3-monthly assessments of tender and swollen joints of year 1 were related to erosion progression, joint space narrowing (JSN) progression and total SHS progression at the individual joint level (definition > 0.5 SHS units) in year 1, corrected for potential confounders and within-patient correlation for multiple joints per patient. During year 1, 59% of all 13 959 joints analysed were ever tender and 45% ever swollen, 2.1% showed erosion progression, 1.9% JSN progression and 3.6% SHS progression. Swelling and tenderness were both independently associated with erosion and JSN progression with comparable OR, although with higher OR in the hands than in the feet. Local swelling and tenderness were not associated with local damage progression in patients initially treated with infliximab. Clinical signs of synovitis are associated with erosion and JSN progression in individual joints after 1 year in RA. A disconnect between synovitis and joint damage progression was observed at joint level in patients who were treated with methotrexate and infliximab as initial treatment, confirming the disconnect between synovitis and the development of joint damage in tumour necrosis factor blockers seen at patient level.

Frequency of radiographic damage and progression in individual joints in children with juvenile idiopathic arthritis.

PubMed

Giancane, Gabriella; Pederzoli, Silvia; Norambuena, Ximena; Ioseliani, Maka; Sato, Juliana; Gallo, Maria Chiara; Negro, Giorgia; Pistorio, Angela; Ruperto, Nicolino; Martini, Alberto; Ravelli, Angelo

2014-01-01

To evaluate the presence and progression of radiographic joint damage, as assessed with the adapted Sharp/van der Heijde score (SHS), in individual joints in the hand and wrist in patients with juvenile idiopathic arthritis (JIA) and to compare progression of damage among different JIA categories. A total of 372 radiographs of both wrists and hands obtained at first observation and at last followup visit (after 1-10 years) in 186 children with polyarticular-course JIA were evaluated. All radiographs were scored using the adapted SHS by 2 independent readers. Radiographic assessment included evaluation of joint space narrowing (JSN) and erosions on baseline and last followup radiographs and of progression of radiographic changes from baseline to last followup radiographs. Both JSN and erosions occurred in all adapted SHS areas. Overall, radiographic damage and progression were more common in the wrist and less common in metacarpophalangeal (MCP) joints. The hamate and capitate areas appeared particularly vulnerable to cartilage loss. Erosions were identified most frequently in the hamate and capitate bones as well as in the second and third metacarpal bases. Patients with extended oligoarthritis were distinctly less susceptible to JSN in hand joints, whereas patients with polyarthritis showed a greater tendency to developing erosions in hand joints. Radiographic joint damage and progression in our patients with JIA were seen most commonly in the wrist and less commonly in MCP joints. The frequency and localization of structural abnormalities differed markedly across disease categories. Copyright © 2014 by the American College of Rheumatology.

Effect of Heat Input on the Tensile Damage Evolution in Pulsed Laser Welded Ti6Al4V Titanium Sheets

NASA Astrophysics Data System (ADS)

Liu, Jing; Gao, Xiaolong; Zhang, Jianxun

2016-11-01

The present paper is focused on studying the effect of heat input on the tensile damage evolution of pulsed Nd:YAG laser welding of Ti6Al4V alloy under monotonic loading. To analyze the reasons that the tensile fracture site of the pulsed-laser-welded Ti6Al4V sheet joints changes with the heat input under monotonic loading, the microstructure of the sample with different nominal strain values was investigated by in situ observation. Experiment results show that the tensile ductility and fatigue life of welded joints with low heat input are higher than that of welded joints with high heat input. Under tensile loads, the critical engineering strain for crack initiation is much lower in the welded joint with high heat input than in the welded joints with low and medium heat input. And the microstructural damage accumulation is much faster in the fusion zone than in the base metal for the welded joints with high input, whereas the microstructural damage accumulation is much faster in the base metal than in the fusion zone for the welded joints with low input. Consequently, the welded joints fractured in the fusion zone for the welds with high heat input, whereas the welded joints ruptured in the base metal for the welds with low heat input. It is proved that the fine grain microstructure produced by low heat input can improve the critical nominal strain for crack initiation and the resistance ability of microstructural damage.

Evidence of cartilage repair by joint distraction in a canine model of osteoarthritis.

PubMed

Wiegant, Karen; Intema, Femke; van Roermund, Peter M; Barten-van Rijbroek, Angelique D; Doornebal, Arie; Hazewinkel, Herman A W; Lafeber, Floris P J G; Mastbergen, Simon C

2015-02-01

Knee osteoarthritis (OA) is a degenerative joint disorder characterized by cartilage, bone, and synovial tissue changes that lead to pain and functional impairment. Joint distraction is a treatment that provides long-term improvement in pain and function accompanied by cartilage repair, as evaluated indirectly by imaging studies and measurement of biochemical markers. The purpose of this study was to evaluate cartilage tissue repair directly by histologic and biochemical assessments after joint distraction treatment. In 27 dogs, OA was induced in the right knee joint (groove model; surgical damage to the femoral cartilage). After 10 weeks of OA development, the animals were randomized to 1 of 3 groups. Two groups were fitted with an external fixator, which they wore for a subsequent 10 weeks (one group with and one without joint distraction), and the third group had no external fixation (OA control group). Pain/function was studied by force plate analysis. Cartilage integrity and chondrocyte activity of the surgically untouched tibial plateaus were analyzed 25 weeks after removal of the fixator. Changes in force plate analysis values between the different treatment groups were not conclusive. Features of OA were present in the OA control group, in contrast to the generally less severe damage after joint distraction. Those treated with joint distraction had lower macroscopic and histologic damage scores, higher proteoglycan content, better retention of newly formed proteoglycans, and less collagen damage. In the fixator group without distraction, similarly diminished joint damage was found, although it was less pronounced. Joint distraction as a treatment of experimentally induced OA results in cartilage repair activity, which corroborates the structural observations of cartilage repair indicated by surrogate markers in humans. Copyright © 2015 by the American College of Rheumatology.

Characteristics of Asperity Damage and Its Influence on the Shear Behavior of Granite Joints

NASA Astrophysics Data System (ADS)

Meng, Fanzhen; Zhou, Hui; Wang, Zaiquan; Zhang, Chuanqing; Li, Shaojun; Zhang, Liming; Kong, Liang

2018-02-01

Surface roughness significantly affects the shear behavior of rock joints; thus, studies on the asperity damage characteristics and its influence on the shear behavior of joints are extremely important. In this paper, shear tests were conducted on tensile granite joints; asperity damage was evaluated based on acoustic emission (AE) events; and the influence of asperity damage on joint shear behavior was analyzed. The results indicated that the total AE events tended to increase with normal stress. In addition, the asperity damage initiation shear stress, which is defined as the transition point from slow growth to rapid growth in the cumulative events curve, was approximately 0.485 of the peak shear strength regardless of the normal stress. Moreover, 63-85% of the AE events were generated after the peak shear stress, indicating that most of the damage occurred in this stage. Both the dilation and the total AE events decreased with shear cycles because of the damage inflicted on asperities during the previous shear cycle. Two stages were observed in the normal displacement curves under low normal stress, whereas three stages (compression, dilation and compression again) were observed at a higher normal stress; the second compression stage may be caused by tensile failure outside the shear plane. The magnitude of the normal stress and the state of asperity are two important factors controlling the post-peak stress drop and stick-slip of granite joints. Serious deterioration of asperities will stop stick-slip from recurring under the same normal stress because the ability to accumulate energy is decreased. The AE b-value increases with the number of shear cycles, indicating that the stress concentration inside the fault plane is reduced because of asperity damage; thus, the potential for dynamic disasters, such as fault-slip rockbursts, will be decreased.

Low Activation Joining of SiC/SiC Composites for Fusion Applications: Thermomechanical Modeling of Dual-Phase Microstructures and Dissimilar Material Joints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Ba Nghiep; Henager, Charles H.; Kurtz, Richard J.

2016-09-30

Finite element (FE) continuum damage mechanics (CDM) models have been developed to simulate and model dual-phase joints and cracked joints for improved analysis of SiC materials in nuclear environments. This report extends the analysis from the last reporting cycle by including preliminary thermomechanical analyses of cracked joints and implementation of dual-phase damage models.

IL-1β, in contrast to TNFα, is pivotal in blood-induced cartilage damage and is a potential target for therapy.

PubMed

van Vulpen, Lize F D; Schutgens, Roger E G; Coeleveld, Katja; Alsema, Els C; Roosendaal, Goris; Mastbergen, Simon C; Lafeber, Floris P J G

2015-11-05

Joint bleeding after (sports) trauma, after major joint surgery, or as seen in hemophilia in general leads to arthropathy. Joint degeneration is considered to result from the direct effects of blood components on cartilage and indirectly from synovial inflammation. Blood-provided proinflammatory cytokines trigger chondrocytes and induce the production of cartilage-degrading proteases. In the presence of erythrocyte-derived iron, cytokines stimulate radical formation in the vicinity of chondrocytes inducing apoptosis. To unravel the role of interleukin (IL) 1β and tumor necrosis factor (TNF) α in the pathogenesis of this blood-induced cartilage damage, the effect of antagonizing these cytokines was examined in human in vitro cultures. Addition of recombinant human IL-1β monoclonal antibody or IL-1 receptor antagonist resulted in a dose- and time-dependent protection of cartilage from blood-induced damage. In higher concentrations, almost complete normalization of cartilage matrix proteoglycan turnover was achieved. This was accompanied by a reduction in IL-1β and IL-6 production in whole blood cultures, whereas TNFα production remained unaffected. Interestingly, addition of a TNFα monoclonal antibody, although demonstrated to inhibit the direct (transient) effects of TNFα on cartilage, exhibited no effect on blood-induced (prolonged) cartilage damage. It is demonstrated that IL-1β is crucial in the development of blood-induced joint damage, whereas TNFα is not. This hierarchical position of IL-1β in blood-induced joint damage warrants studies on targeting IL-1β to potentially prevent joint degeneration after a joint bleed. © 2015 by The American Society of Hematology.

Hydrogels as a Replacement Material for Damaged Articular Hyaline Cartilage

PubMed Central

Beddoes, Charlotte M.; Whitehouse, Michael R.; Briscoe, Wuge H.; Su, Bo

2016-01-01

Hyaline cartilage is a strong durable material that lubricates joint movement. Due to its avascular structure, cartilage has a poor self-healing ability, thus, a challenge in joint recovery. When severely damaged, cartilage may need to be replaced. However, currently we are unable to replicate the hyaline cartilage, and as such, alternative materials with considerably different properties are used. This results in undesirable side effects, including inadequate lubrication, wear debris, wear of the opposing articular cartilage, and weakening of the surrounding tissue. With the number of surgeries for cartilage repair increasing, a need for materials that can better mimic cartilage, and support the surrounding material in its typical function, is becoming evident. Here, we present a brief overview of the structure and properties of the hyaline cartilage and the current methods for cartilage repair. We then highlight some of the alternative materials under development as potential methods of repair; this is followed by an overview of the development of tough hydrogels. In particular, double network (DN) hydrogels are a promising replacement material, with continually improving physical properties. These hydrogels are coming closer to replicating the strength and toughness of the hyaline cartilage, while offering excellent lubrication. We conclude by highlighting several different methods of integrating replacement materials with the native joint to ensure stability and optimal behaviour. PMID:28773566

Hydrogels as a Replacement Material for Damaged Articular Hyaline Cartilage.

PubMed

Beddoes, Charlotte M; Whitehouse, Michael R; Briscoe, Wuge H; Su, Bo

2016-06-03

Hyaline cartilage is a strong durable material that lubricates joint movement. Due to its avascular structure, cartilage has a poor self-healing ability, thus, a challenge in joint recovery. When severely damaged, cartilage may need to be replaced. However, currently we are unable to replicate the hyaline cartilage, and as such, alternative materials with considerably different properties are used. This results in undesirable side effects, including inadequate lubrication, wear debris, wear of the opposing articular cartilage, and weakening of the surrounding tissue. With the number of surgeries for cartilage repair increasing, a need for materials that can better mimic cartilage, and support the surrounding material in its typical function, is becoming evident. Here, we present a brief overview of the structure and properties of the hyaline cartilage and the current methods for cartilage repair. We then highlight some of the alternative materials under development as potential methods of repair; this is followed by an overview of the development of tough hydrogels. In particular, double network (DN) hydrogels are a promising replacement material, with continually improving physical properties. These hydrogels are coming closer to replicating the strength and toughness of the hyaline cartilage, while offering excellent lubrication. We conclude by highlighting several different methods of integrating replacement materials with the native joint to ensure stability and optimal behaviour.

Cyclic loading increases friction and changes cartilage surface integrity in lubricin-mutant mouse knees

PubMed Central

Drewniak, Elizabeth I; Jay, Gregory D; Fleming, Braden C; Zhang, Ling; Warman, Matthew L; Crisco, Joseph J

2012-01-01

Objective To investigate the effects of lubricin gene dosage and cyclic loading on whole joint coefficient of friction and articular cartilage surface integrity in mouse knee joints. Methods Joints from mice with 2 (Prg4+/+), 1 (Prg4+/−), or no (Prg4−/−) functioning lubricin alleles were subjected to 26 hours of cyclic loading using a custom-built pendulum. Coefficient of friction values were measured at multiple time points. Contralateral control joints were left unloaded. Following testing, joints were examined for histologic evidence of damage and cell viability. Results At baseline, the coefficient of friction values in Prg4−/− mice were significantly higher than those in Prg4+/+ and Prg4+/− mice (P < 0.001). Cyclic loading continuously increased the coefficient of friction in Prg4−/− mouse joints. In contrast, Prg4+/− and Prg4+/+ mouse joints had no coefficient of friction increases during the first 4 hours of loading. After 26 hours of loading, joints from all genotypes had increased coefficient of friction values compared to baseline and unloaded controls. Significantly greater increases occurred in Prg4−/− and Prg4+/− mouse joints compared to Prg4+/+ mouse joints. The coefficient of friction values were not significantly associated with histologic evidence of damage or loss of cell viability. Conclusion Our findings indicate that mice lacking lubricin have increased baseline coefficient of friction values and are not protected against further increases caused by loading. Prg4+/− mice are indistinguishable from Prg4+/+ mice at baseline, but have significantly greater coefficient of friction values following 26 hours of loading. Lubricin dosage affects joint properties during loading, and may have clinical implications in patients for whom injury or illness alters lubricin abundance. PMID:21905020

[Application of temporomandibular joint dics reduction in the operation of condylar sagittal fracture].

PubMed

Wenli, Zeng; Wuchao, Zhou; Jingkun, Zhang; Yisen, Shao; Weihong, Xi

2017-10-01

To explore the selection of temporomandibular joint (TMJ) disc reduction and fixation methods in condylar sagittal fracture surgery. A total of 36 patients with condylar fractures were chosen. The follow-up period was more 6 months. All 36 cases of condylar sagittal fracture were fixed with long screw. In the operation, the displaced joint disc was repositioned and fixed. The fixed method included direct suture (22 cases) and anchorage (14 cases). Clinical followups were performed before surgery and 1 month, 3 months, 6 months and 1 year after surgery. Clinicians recorded data related to the Fricton craniomandibular index (CMI) and evaluated the postoperative joint function during followup before surgery and 6 months after surgery. In both groups, function of TMJ significantly improved after surgery. The CMI decreased from 0.213±0.162 and 0.273±0.154 to 0.059±0.072 and 0.064±0.068 (P<0.05), respectively. No statistical difference was observed between the two groups in palpation index (PI), dysfunction index (DI) and CMI (P>0.05) before or after surgery. Both methods could effectively improve the dysfunction of the TMJ caused by trauma. The selection of joint disc reduction and fixation methods is based on the displacement and damage degree of the joint disc.

A case-study in the clinical epidemiology of psoriatic arthritis: multistate models and causal arguments

PubMed Central

O'Keeffe, Aidan G; Tom, Brian D M; Farewell, Vernon T

2011-01-01

In psoriatic arthritis, permanent joint damage characterizes disease progression and represents a major debilitating aspect of the disease. Understanding the process of joint damage will assist in the treatment and disease management of patients. Multistate models provide a means to examine patterns of disease, such as symmetric joint damage. Additionally, the link between damage and the dynamic course of disease activity (represented by joint swelling and stress pain) at both the individual joint level and otherwise can be represented within a correlated multistate model framework. Correlation is reflected through the use of random effects for progressive models and robust variance estimation for non-progressive models. Such analyses, undertaken with data from a large psoriatic arthritis cohort, are discussed and the extent to which they permit causal reasoning is considered. For this, emphasis is given to the use of the Bradford Hill criteria for causation in observational studies and the concept of local (in)dependence to capture the dynamic nature of the relationships. PMID:22163372

High-Resolution Methods for Diagnosing Cartilage Damage In Vivo

PubMed Central

Novakofski, Kira D.; Pownder, Sarah L.; Koff, Matthew F.; Williams, Rebecca M.; Potter, Hollis G.; Fortier, Lisa A.

2016-01-01

Advances in current clinical modalities, including magnetic resonance imaging and computed tomography, allow for earlier diagnoses of cartilage damage that could mitigate progression to osteoarthritis. However, current imaging modalities do not detect submicrometer damage. Developments in in vivo or arthroscopic techniques, including optical coherence tomography, ultrasonography, bioelectricity including streaming potential measurement, noninvasive electroarthrography, and multiphoton microscopy can detect damage at an earlier time point, but they are limited by a lack of penetration and the ability to assess an entire joint. This article reviews current advancements in clinical and developing modalities that can aid in the early diagnosis of cartilage injury and facilitate studies of interventional therapeutics. PMID:26958316

Development of Guidelines for In-Situ Repair of SLS-Class Composite Flight Hardware

NASA Technical Reports Server (NTRS)

Weber, Thomas P., Jr.; Cox, Sarah B.

2018-01-01

The purpose of composite repair development at KSC (John F. Kennedy Space Center) is to provide support to the CTE (Composite Technology for Exploration) project. This is a multi-space center effort with the goal of developing bonded joint technology for SLS (Space Launch System) -scale composite hardware. At KSC, effective and efficient repair processes need to be developed to allow for any potential damage to composite components during transport or launch preparation. The focus of the composite repair development internship during the spring of 2018 was on the documentation of repair processes and requirements for process controls based on techniques developed through hands-on work with composite test panels. Three composite test panels were fabricated for the purpose of repair and surface preparation testing. The first panel included a bonded doubler and was fabricated to be damaged and repaired. The second and third panels were both fabricated to be cut into lap-shear samples to test the strength of bond of different surface preparation techniques. Additionally, jointed composite test panels were impacted at MSFC (Marshall Space Flight Center) and analyzed for damage patterns. The observations after the impact tests guided the repair procedure at KSC to focus on three repair methods. With a finalized repair plan in place, future work will include the strength testing of different surface preparation techniques, demonstration of repair methods, and repair of jointed composite test panels being impacted at MSFC.

Whole-body vibration of mice induces articular cartilage degeneration with minimal changes in subchondral bone.

PubMed

McCann, M R; Yeung, C; Pest, M A; Ratneswaran, A; Pollmann, S I; Holdsworth, D W; Beier, F; Dixon, S J; Séguin, C A

2017-05-01

Low-amplitude, high-frequency whole-body vibration (WBV) has been adopted for the treatment of musculoskeletal diseases including osteoarthritis (OA); however, there is limited knowledge of the direct effects of vibration on joint tissues. Our recent studies revealed striking damage to the knee joint following exposure of mice to WBV. The current study examined the effects of WBV on specific compartments of the murine tibiofemoral joint over 8 weeks, including microarchitecture of the tibia, to understand the mechanisms associated with WBV-induced joint damage. Ten-week-old male CD-1 mice were exposed to WBV (45 Hz, 0.3 g peak acceleration; 30 min/day, 5 days/week) for 4 weeks, 8 weeks, or 4 weeks WBV followed by 4 weeks recovery. The knee joint was evaluated histologically for tissue damage. Architecture of the subchondral bone plate, subchondral trabecular bone, primary and secondary spongiosa of the tibia was assessed using micro-CT. Meniscal tears and focal articular cartilage damage were induced by WBV; the extent of damage increased between 4 and 8-week exposures to WBV. WBV did not alter the subchondral bone plate, or trabecular bone of the tibial spongiosa; however, a transient increase was detected in the subchondral trabecular bone volume and density. The lack of WBV-induced changes in the underlying subchondral bone suggests that damage to the articular cartilage may be secondary to the meniscal injury we detected. Our findings underscore the need for further studies to assess the safety of WBV in the human population to avoid long-term joint damage. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

78 FR 6251 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-30

... airplanes. This proposed AD was prompted by reports of cracks and heat damage on pivot joint components... proposing this AD to detect and correct heat damage and cracks in the pivot pin, truck beam lugs, and inner... joint components have been found with cracks or heat damage. There have been 11 such findings on Model...

The role of tissue damage in whiplash associated disorders: Discussion paper 1

PubMed Central

Bogduk, Nikolai; Ivancic, Paul C.; McLean, Samuel A.; Siegmund, Gunter P.; Winkelstein, Beth

2011-01-01

STUDY DESIGN Non-systematic review of cervical spine lesions in whiplash-associated disorders (WAD). OBJECTIVE To describe whiplash injury models in terms of basic and clinical science, to summarize what can and cannot be explained by injury models, and to highlight future research areas to better understand the role of tissue damage in WAD. SUMMARY OF BACKGROUND DATA The frequent lack of detectable tissue damage has raised questions about whether tissue damage is necessary for WAD and what role it plays in the clinical context of WAD. METHODS Non-systematic review. RESULTS Lesions of various tissues have been documented by numerous investigations conducted in animals, cadavers, healthy volunteers and patients. Most lesions are undetected by imaging techniques. For zygapophysial (facet) joints, lesions have been predicted by bioengineering studies and validated through animal studies; for zygapophysial joint pain, a valid diagnostic test and a proven treatment are available. Lesions of dorsal root ganglia, discs, ligaments, muscles and vertebral artery have been documented in biomechanical and autopsy studies, but no valid diagnostic test is available to assess their clinical relevance. The proportion of WAD patients in whom a persistent lesion is the major determinant of ongoing symptoms is unknown. Psychosocial factors, stress reactions and generalized hyperalgesia have also been shown to predict WAD outcomes. CONCLUSION There is evidence supporting a lesion-based model in WAD. Lack of macroscopically identifiable tissue damage does not rule out the presence of painful lesions. The best available evidence concerns zygapophysial joint pain. The clinical relevance of other lesions needs to be addressed by future research. PMID:22020601

MRI evidence of persistent joint inflammation and progressive joint damage despite clinical remission during treatment of early rheumatoid arthritis.

PubMed

Forslind, K; Svensson, B

2016-01-01

To determine the value of magnetic resonance imaging (MRI) of bones and joints in patients with recent-onset rheumatoid arthritis (RA) treated for 2 years from diagnosis with disease-modifying anti-rheumatic drugs (DMARDs) and glucocorticoids. Thirteen patients with early RA were treated according to clinical practice and followed with MRI, radiographs, and Disease Activity Score calculated on 28 joints (DAS28) at inclusion (baseline) and after 1, 4, 7, 13, and 25 months. MRI of the dominant wrist and metacarpophalangeal (MCP) joints were assessed for synovitis, bone oedema, and erosions using the RA MRI Score (RAMRIS) and for tenosynovitis by an MRI tenosynovitis scoring method. Radiographs were assessed by the van der Heijde modified Sharp score (SHS). Clinical remission was defined by a DAS28 < 2.6. MRI at baseline detected inflammation in joints and tendons in all patients as well as erosions in 10 out of 13 patients. Over time, the erosion score increased while the synovitis and tenosynovitis scores remained almost unchanged. Bone oedema strongly correlated with synovitis. Synovitis and tenosynovitis correlated well with the erosion score at baseline but not thereafter. The MRI changes showed that joint damage started early and continued in the presence of persistent synovial and tenosynovial inflammation. The observations made in this small study suggest that the treatment goal of 'clinical remission' should be supplemented by a 'joint remission' goal. To this end, MRI is an appropriate tool. Further studies are needed to evaluate the optimal use of MRI in early RA.

Validation of automatic joint space width measurements in hand radiographs in rheumatoid arthritis.

PubMed

Schenk, Olga; Huo, Yinghe; Vincken, Koen L; van de Laar, Mart A; Kuper, Ina H H; Slump, Kees C H; Lafeber, Floris P J G; Bernelot Moens, Hein J

2016-10-01

Computerized methods promise quick, objective, and sensitive tools to quantify progression of radiological damage in rheumatoid arthritis (RA). Measurement of joint space width (JSW) in finger and wrist joints with these systems performed comparable to the Sharp-van der Heijde score (SHS). A next step toward clinical use, validation of precision and accuracy in hand joints with minimal damage, is described with a close scrutiny of sources of error. A recently developed system to measure metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints was validated in consecutive hand images of RA patients. To assess the impact of image acquisition, measurements on radiographs from a multicenter trial and from a recent prospective cohort in a single hospital were compared. Precision of the system was tested by comparing the joint space in mm in pairs of subsequent images with a short interval without progression of SHS. In case of incorrect measurements, the source of error was analyzed with a review by human experts. Accuracy was assessed by comparison with reported measurements with other systems. In the two series of radiographs, the system could automatically locate and measure 1003/1088 (92.2%) and 1143/1200 (95.3%) individual joints, respectively. In joints with a normal SHS, the average (SD) size of MCP joints was [Formula: see text] and [Formula: see text] in the two series of radiographs, and of PIP joints [Formula: see text] and [Formula: see text]. The difference in JSW between two serial radiographs with an interval of 6 to 12 months and unchanged SHS was [Formula: see text], indicating very good precision. Errors occurred more often in radiographs from the multicenter cohort than in a more recent series from a single hospital. Detailed analysis of the 55/1125 (4.9%) measurements that had a discrepant paired measurement revealed that variation in the process of image acquisition (exposure in 15% and repositioning in 57%) was a more frequent source of error than incorrect delineation by the software (25%). Various steps in the validation of an automated measurement system for JSW of MCP and PIP joints are described. The use of serial radiographs from different sources, with a short interval and limited damage, is helpful to detect sources of error. Image acquisition, in particular repositioning, is a dominant source of error.

Using magnetic resonance imaging to determine the compartmental prevalence of knee joint structural damage.

PubMed

Stefanik, J J; Niu, J; Gross, K D; Roemer, F W; Guermazi, A; Felson, D T

2013-05-01

To describe the prevalence of magnetic resonance imaging (MRI) detected structural damage in the patellofemoral joint (PFJ) and tibiofemoral joint (TFJ) in a population-based cohort. A secondary aim was to evaluate the patterns of compartmental involvement in knees with pain, between men and women, and in different age and body mass index (BMI) categories. We studied 970 knees, one knee per subject, from the Framingham Osteoarthritis Study, a population-based cohort study of persons 51-92 years old. Cartilage damage and bone marrow lesions (BMLs) were assessed using the Whole Organ Magnetic Resonance Imaging Score (WORMS). The prevalence of isolated PFJ, isolated TFJ, and mixed structural damage was determined using the following definitions: any cartilage damage, full thickness cartilage loss, any BML, and the combination of full thickness cartilage loss with any BML. The mean age and BMI was 63.4 years and 28.6 m/kg(2), respectively; 57% were female. Isolated PFJ damage occurred in 15-20% of knees and isolated TFJ damage occurred in 8-17% of knees depending on the definition used. The prevalence of isolated PFJ damage was greater than isolated TFJ damage using all definitions except the any BML definition. This pattern was similar between genders and among age and BMI categories. In those with knee pain, isolated PFJ was at least as common as TFJ damage depending on the definition used. Using MRI to assess knee joint structural damage, isolated PFJ damage was at least as common as, if not more common than, isolated TFJ damage. Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

The value of HEAD-US system in detecting subclinical abnormalities in joints of patients with hemophilia.

PubMed

De la Corte-Rodriguez, Hortensia; Rodriguez-Merchan, E Carlos; Alvarez-Roman, M Teresa; Martin-Salces, Mónica; Martinoli, Carlo; Jimenez-Yuste, Víctor

2018-03-01

Prevention of hemarthrosis is the key factor in the adequate management of people with hemophilia (PWH). If hemarthrosis occurs, early diagnosis of joint damage is essential to make personalized treatments. This study is aimed at gaining an understanding of the ability of point-of-care ultrasound (US) using the `Hemophilia Early Arthropathy Detection with Ultrasound´ (HEAD-US) protocol to detect abnormalities in joints without history of hemarthrosis and clinically asymptomatic joints of PWH. The sample included 976 joints from 167 PWH (mean age 24.86 years). Data were collected from routine practice over a 3-year period and analyzed based on history of hemarthrosis and results of clinical (HJHS 2.1) and HEAD-US examinations. In our series, 14% of patients exhibited HEAD-US signs of incipient arthropathy in joints with no history of bleeding and with a HJHS 2.1 score of 0. The most severely involved joint was the right ankle. Synovitis, articular cartilage and subchondral bone damage scores in joints with subclinical findings were slower than in joints with previous hemarthroses or HJHS 2.1 > 1 Conclusions: Our study demonstrates that HEAD-US is better than hemarthrosis records and the HJHS 2.1 scale in detecting the early signs of joint damage in PWH.

Tissue structure modification in knee osteoarthritis by use of joint distraction: an open 1-year pilot study

PubMed Central

Intema, Femke; Van Roermund, Peter M; Marijnissen, Anne C A; Cotofana, Sebastian; Eckstein, Felix; Castelein, Rene M; Bijlsma, Johannes W J; Mastbergen, Simon C; Lafeber, Floris P J G

2011-01-01

Background Modification of joint tissue damage is challenging in late-stage osteoarthritis (OA). Few options are available for treating end-stage knee OA other than joint replacement. Objectives To examine whether joint distraction can effectively modify knee joint tissue damage and has the potential to delay prosthesis surgery. Methods 20 patients (<60 years) with tibiofemoral OA were treated surgically using joint distraction. Distraction (∼5 mm) was applied for 2 months using an external fixation frame. Tissue structure modification at 1 year of follow-up was evaluated radiographically (joint space width (JSW)), by MRI (segmentation of cartilage morphology) and by biochemical markers of collagen type II turnover, with operators blinded to time points. Clinical improvement was evaluated by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Visual Analogue Scale (VAS) pain score. Results Radiography demonstrated an increase in mean and minimum JSW (2.7 to 3.6 mm and 1.0 to 1.9 mm; p<0.05 and <0.01). MRI revealed an increase in cartilage thickness (2.4 to 3.0 mm; p<0.001) and a decrease of denuded bone areas (22% to 5%; p<0.001). Collagen type II levels showed a trend towards increased synthesis (+103%; p<0.06) and decreased breakdown (−11%; p<0.08). The WOMAC index increased from 45 to 77 points, and VAS pain decreased from 73 to 31 mm (both p<0.001). Conclusions Joint distraction can induce tissue structure modification in knee OA and could result in clinical benefit. No current treatment is able to induce such changes. Larger, longer and randomised studies on joint distraction are warranted. PMID:21565898

Kirschner-wire fixation for postburn flexion contracture deformity and consequences on articular surface.

PubMed

Sungur, Nezih; Ulusoy, Mustafa Gürhan; Boyacgil, Süreyya; Ortaparmak, Hülya; Akyüz, Mihriban; Ortak, Turgut; Koçer, Uğur; Sensöz, Omer

2006-02-01

Kirschner-wire (K-wire) fixation for 3-6 weeks is an approved method for stabilization of the fingers after the release of flexion contracture deformity. On the other hand, articular surface damage in small joints due to pin fixation is still a topic of debate. Reports claiming permanent joint destruction due to this procedure exist in the literature. To clarify this doubt, a prospective study was carried out in 72 patients with flexion contracture of the hand fingers. After the surgical release of the deformity, immobilization of the interphalangeal (IP) and metacarpophalangeal (MCP) joints was carried out with K-wire fixation for 3 weeks. Clinical evaluation of the patients was accomplished with total active motion (TAM), grip, and pinch force measurements, whereas magnetic resonance (MR) and radionuclide imaging were used as radiodiagnostic tools. Mean follow-up period of the patients was 32 months. Satisfactory results were obtained in terms of functional and esthetic aspects. Evaluation of the data derived from the clinical and radiologic measurements revealed no permanent articular surface damage. K-wire fixation was documented to be an invaluable therapeutic approach not only to prevent recurrence of the contracture deformity but also to stabilize the skin graft effectively. This technique was concluded to provide effective immobilization without permanent articular damage.

Multifrequency Eddy Current Inspection of Corrosion in Clad Aluminum Riveted Lap Joints and Its Effect on Fatigue Life

NASA Astrophysics Data System (ADS)

Okafor, A. C.; Natarajan, S.

2007-03-01

Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

Fatigue Damage Monitoring of a Composite Step Lap Joint Using Distributed Optical Fibre Sensors

PubMed Central

Wong, Leslie; Chowdhury, Nabil; Wang, John; Chiu, Wing Kong; Kodikara, Jayantha

2016-01-01

Over the past few decades, there has been a considerable interest in the use of distributed optical fibre sensors (DOFS) for structural health monitoring of composite structures. In aerospace-related work, health monitoring of the adhesive joints of composites has become more significant, as they can suffer from cracking and delamination, which can have a significant impact on the integrity of the joint. In this paper, a swept-wavelength interferometry (SWI) based DOFS technique is used to monitor the fatigue in a flush step lap joint composite structure. The presented results will show the potential application of distributed optical fibre sensor for damage detection, as well as monitoring the fatigue crack growth along the bondline of a step lap joint composite structure. The results confirmed that a distributed optical fibre sensor is able to enhance the detection of localised damage in a structure. PMID:28773496

Increased expression of damage-associated molecular patterns (DAMPs) in osteoarthritis of human knee joint compared to hip joint.

PubMed

Rosenberg, John H; Rai, Vikrant; Dilisio, Matthew F; Sekundiak, Todd D; Agrawal, Devendra K

2017-12-01

Osteoarthritis (OA) is a degenerative disease characterized by the destruction of cartilage. The greatest risk factors for the development of OA include age and obesity. Recent studies suggest the role of inflammation in the pathogenesis of OA. The two most common locations for OA to occur are in the knee and hip joints. The knee joint experiences more mechanical stress, cartilage degeneration, and inflammation than the hip joint. This could contribute to the increased incidence of OA in the knee joint. Damage-associated molecular patterns (DAMPs), including high-mobility group box-1, receptor for advanced glycation end products, and alarmins (S100A8 and S100A9), are released in the joint in response to stress-mediated chondrocyte and cartilage damage. This facilitates increased cartilage degradation and inflammation in the joint. Studies have documented the role of DAMPs in the pathogenesis of OA; however, the comparison of DAMPs and its influence on OA has not been discussed. In this study, we compared the DAMPs between OA knee and hip joints and found a significant difference in the levels of DAMPs expressed in the knee joint compared to the hip joint. The increased levels of DAMPs suggest a difference in the underlying pathogenesis of OA in the knee and the hip and highlights DAMPs as potential therapeutic targets for OA in the future.

Low Activation Joining of SiC/SiC Composites for Fusion Applications: Modeling Miniature Torsion Tests with Elastic and Elastic-Plastic Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.

2015-03-01

The use of SiC and SiC-composites in fission or fusion environments requires joining methods for assembling systems. The international fusion community designed miniature torsion specimens for joint testing and irradiation in test reactors with limited irradiation volumes. These torsion specimens fail out-of-plane when joints are strong and when elastic moduli are within a certain range compared to SiC, which causes difficulties in determining shear strengths for joints or for comparing unirradiated and irradiated joints. A finite element damage model was developed that indicates fracture is likely to occur within the joined pieces to cause out-of-plane failures for miniature torsion specimensmore » when a certain modulus and strength ratio between the joint material and the joined material exists. The model was extended to treat elastic-plastic joints such as SiC/epoxy and steel/epoxy joints tested as validation of the specimen design.« less

Studies of cartilaginous tissue using Raman spectroscopy method

NASA Astrophysics Data System (ADS)

Timchenko, Pavel E.; Timchenko, Elena V.; Volova, Larisa T.; Dolgyshkin, Dmitry A.; Markova, Maria D.; Kylabyhova, A. Y.; Kornilin, Dmitriy V.

2016-10-01

The work presents the results of studies of samples of human articular surface of the knee joint, obtained by Raman spectroscopy implementedduring endoprosthesis replacement surgery . The main spectral characteristics of articular surface areas with varying degrees of cartilage damage were detected at 956 cm-1, 1066 cm-1 wavenumbers, corresponding to phosphate and carbonate, and at 1660 cm-1, 1271 cm-1 wavenumbers, corresponding to amide I and amide III. Criteria allowing to identify the degree of articular hyaline cartilage damage were introduced.

Joint bleeds in von Willebrand disease patients have significant impact on quality of life and joint integrity: a cross-sectional study.

PubMed

van Galen, K P M; Sanders, Y V; Vojinovic, U; Eikenboom, J; Cnossen, M H; Schutgens, R E G; van der Bom, J G; Fijnvandraat, K; Laros-Van Gorkom, B A P; Meijer, K; Leebeek, F W G; Mauser-Bunschoten, E P

2015-05-01

Joint bleeds (JB) are reported in a minority of patients with von Willebrand disease (VWD) but may lead to structural joint damage. Prevalence, severity and impact of JB in VWD are largely unknown. The aim of this study was to assess JB prevalence, onset, treatment and impact on health-related quality of life (HR-QoL) and joint integrity in moderate and severe VWD. In the Willebrand in the Netherlands study 804 moderate and severe VWD patients [von Willebrand factor (VWF) activity ≤30U dL(-1)] completed a questionnaire on occurrence, sites and consequences of JB. To analyse JB number, onset, treatment and impact on joint integrity we additionally performed a patient-control study on medical file data comparing patients with JB to age, gender, factor VIII (FVIII)- and VWF activity matched VWD patients without JB. Of all VWD patients 23% (184/804) self-reported JB. These 184 patients reported joint damage more often (54% vs. 18%, P < 0.001) and had lower HR-QoL (SF36, P < 0.05) compared to VWD patients not reporting JB. Of 55 patients with available JB data, 65% had the first JB before age 16. These 55 patients used more clotting factor concentrate (CFC; median dose 43 vs. 0 IE FVIII kg(-1) year(-1) , P < 0.001), more often had X-ray joint damage (44% vs. 11%, P = 0.001] and chronic joint pain (44% vs. 18%, P = 0.008) compared to 55 control VWD patients without JB. In conclusion, joint bleeds are reported by 23% of moderate and severe VWD patients, mostly start in childhood, are associated with more CFC use, joint pain, lower HR-QoL and significantly more radiological and self-reported joint damage. © 2015 John Wiley & Sons Ltd.

FEM investigation of concrete silos damaged and reinforced externally with CFRP

NASA Astrophysics Data System (ADS)

Kermiche, Sihem; Boussaid, Ouzine; Redjel, Bachir; Amirat, Abdelaziz

2018-03-01

The present work investigates the reinforcement of concrete wheat-grain silos under initial damage. The reinforcement is achieved by mounting bands of carbon fiber reinforced polymer (CFRP) on the external walls of the silo. 4 modes of reinforcement are adapted according to the width of the band, the gap between two bands, the height of reinforcement and the number of layers achieved through banding. Analytical analyses were conducted using the Reimbert method and the Eurocode 1 Part 4 method, as well as numerically through the finite element software Abaqus. Results show that the normal pressure reaches a peak value when approaching the silo hopper. Initial damage in a concrete silo was first determined using a 3D geometrical model, while the damage analyses were conducted to optimize the CFRP reinforcement by mounting 2 CFRP bands close together above and below the cylinder-hopper joint. Increasing the number of banding layers could produce better performance as the damage was slightly decreased from 0.161 to 0.152 for 1 and 4 layers respectively.

Computational predictive methods for fracture and fatigue

NASA Technical Reports Server (NTRS)

Cordes, J.; Chang, A. T.; Nelson, N.; Kim, Y.

1994-01-01

The damage-tolerant design philosophy as used by aircraft industries enables aircraft components and aircraft structures to operate safely with minor damage, small cracks, and flaws. Maintenance and inspection procedures insure that damages developed during service remain below design values. When damage is found, repairs or design modifications are implemented and flight is resumed. Design and redesign guidelines, such as military specifications MIL-A-83444, have successfully reduced the incidence of damage and cracks. However, fatigue cracks continue to appear in aircraft well before the design life has expired. The F16 airplane, for instance, developed small cracks in the engine mount, wing support, bulk heads, the fuselage upper skin, the fuel shelf joints, and along the upper wings. Some cracks were found after 600 hours of the 8000 hour design service life and design modifications were required. Tests on the F16 plane showed that the design loading conditions were close to the predicted loading conditions. Improvements to analytic methods for predicting fatigue crack growth adjacent to holes, when multiple damage sites are present, and in corrosive environments would result in more cost-effective designs, fewer repairs, and fewer redesigns. The overall objective of the research described in this paper is to develop, verify, and extend the computational efficiency of analysis procedures necessary for damage tolerant design. This paper describes an elastic/plastic fracture method and an associated fatigue analysis method for damage tolerant design. Both methods are unique in that material parameters such as fracture toughness, R-curve data, and fatigue constants are not required. The methods are implemented with a general-purpose finite element package. Several proof-of-concept examples are given. With further development, the methods could be extended for analysis of multi-site damage, creep-fatigue, and corrosion fatigue problems.

Computational predictive methods for fracture and fatigue

NASA Astrophysics Data System (ADS)

Cordes, J.; Chang, A. T.; Nelson, N.; Kim, Y.

1994-09-01

The damage-tolerant design philosophy as used by aircraft industries enables aircraft components and aircraft structures to operate safely with minor damage, small cracks, and flaws. Maintenance and inspection procedures insure that damages developed during service remain below design values. When damage is found, repairs or design modifications are implemented and flight is resumed. Design and redesign guidelines, such as military specifications MIL-A-83444, have successfully reduced the incidence of damage and cracks. However, fatigue cracks continue to appear in aircraft well before the design life has expired. The F16 airplane, for instance, developed small cracks in the engine mount, wing support, bulk heads, the fuselage upper skin, the fuel shelf joints, and along the upper wings. Some cracks were found after 600 hours of the 8000 hour design service life and design modifications were required. Tests on the F16 plane showed that the design loading conditions were close to the predicted loading conditions. Improvements to analytic methods for predicting fatigue crack growth adjacent to holes, when multiple damage sites are present, and in corrosive environments would result in more cost-effective designs, fewer repairs, and fewer redesigns. The overall objective of the research described in this paper is to develop, verify, and extend the computational efficiency of analysis procedures necessary for damage tolerant design. This paper describes an elastic/plastic fracture method and an associated fatigue analysis method for damage tolerant design. Both methods are unique in that material parameters such as fracture toughness, R-curve data, and fatigue constants are not required. The methods are implemented with a general-purpose finite element package. Several proof-of-concept examples are given. With further development, the methods could be extended for analysis of multi-site damage, creep-fatigue, and corrosion fatigue problems.

Evaluation of joint findings with gait analysis in children with hemophilia.

PubMed

Cayir, Atilla; Yavuzer, Gunes; Sayli, Revide Tülin; Gurcay, Eda; Culha, Vildan; Bozkurt, Murat

2014-01-01

Hemophilic arthropathy due to recurrent joint bleeding leads to physical, psychological and socioeconomic problems in children with hemophilia and reduces their quality of life. The purpose of this study was to evaluate joint damage through various parameters and to determine functional deterioration in the musculoskeletal system during walking using kinetic and kinematic gait analysis. Physical examination and kinetic and kinematic gait analysis findings of 19 hemophilic patients aged 7-20 years were compared with those of age, sex and leg length matched controls. Stride time was longer in the hemophilia group (p=0.001) compared to the age matched healthy control group, while hip, knee and ankle joint rotation angles were more limited (p=0.001, p=0.035 and p=0.001, respectively). In the hemophilia group, the extensor moment of the knee joint in the stance phase was less than that in the control group (p=0.001). Stride time was longer in the severe hemophilia group compared to the mild-moderate hemophilia and control groups (p=0.011 and p=0.001, respectively). Rotation angle of the ankle was wider in the control group compared to the other two groups (p=0.001 for both). Rotation angle of the ankle joint was narrower in the severe hemophilia group compared to the others (p=0.001 for each). Extensor moment of the knee joint was greater in the control group compared to the other two groups (p=0.003 and p=0.001, respectively). Walking velocity was higher in the control group compared to the severe hemophilia group. Kinetic and kinematic gait analysis has the sensitivity to detect minimal changes in biomechanical parameters. Gait analysis can be used as a reliable method to detect early joint damage.

Quantitative metal magnetic memory reliability modeling for welded joints

NASA Astrophysics Data System (ADS)

Xing, Haiyan; Dang, Yongbin; Wang, Ben; Leng, Jiancheng

2016-03-01

Metal magnetic memory(MMM) testing has been widely used to detect welded joints. However, load levels, environmental magnetic field, and measurement noises make the MMM data dispersive and bring difficulty to quantitative evaluation. In order to promote the development of quantitative MMM reliability assessment, a new MMM model is presented for welded joints. Steel Q235 welded specimens are tested along the longitudinal and horizontal lines by TSC-2M-8 instrument in the tensile fatigue experiments. The X-ray testing is carried out synchronously to verify the MMM results. It is found that MMM testing can detect the hidden crack earlier than X-ray testing. Moreover, the MMM gradient vector sum K vs is sensitive to the damage degree, especially at early and hidden damage stages. Considering the dispersion of MMM data, the K vs statistical law is investigated, which shows that K vs obeys Gaussian distribution. So K vs is the suitable MMM parameter to establish reliability model of welded joints. At last, the original quantitative MMM reliability model is first presented based on the improved stress strength interference theory. It is shown that the reliability degree R gradually decreases with the decreasing of the residual life ratio T, and the maximal error between prediction reliability degree R 1 and verification reliability degree R 2 is 9.15%. This presented method provides a novel tool of reliability testing and evaluating in practical engineering for welded joints.

Experimental Investigation of the Influence of Joint Geometric Configurations on the Mechanical Properties of Intermittent Jointed Rock Models Under Cyclic Uniaxial Compression

NASA Astrophysics Data System (ADS)

Liu, Yi; Dai, Feng; Fan, Pengxian; Xu, Nuwen; Dong, Lu

2017-06-01

Intermittent joints in rock mass are quite sensitive to cyclic loading conditions. Understanding the fatigue mechanical properties of jointed rocks is beneficial for rational design and stability analysis of rock engineering projects. This study experimentally investigated the influences of joint geometry (i.e., dip angle, persistency, density and spacing) on the fatigue mechanism of synthetic jointed rock models. Our results revealed that the stress-strain curve of jointed rock under cyclic loadings is dominated by its curve under monotonic uniaxial loadings; the terminal strain in fatigue curve is equal to the post-peak strain corresponding to the maximum cyclic stress in the monotonic stress-strain curve. The four joint geometrical parameters studied significantly affect the fatigue properties of jointed rocks, including the irreversible strains, the fatigue deformation modulus, the energy evolution, the damage variable and the crack coalescence patterns. The higher the values of the geometrical parameters, the lower the elastic energy stores in this jointed rock, the higher the fatigue damage accumulates in the first few cycles, and the lower the fatigue life. The elastic energy has certain storage limitation, at which the fatigue failure occurs. Two basic micro-cracks, i.e., tensile wing crack and shear crack, are observed in cyclic loading and unloading tests, which are controlled principally by joint dip angle and persistency. In general, shear cracks only occur in the jointed rock with higher dip angle or higher persistency, and the jointed rock is characterized by lower fatigue strength, larger damage variable and lower fatigue life.

A review of typical thermal fatigue failure models for solder joints of electronic components

NASA Astrophysics Data System (ADS)

Li, Xiaoyan; Sun, Ruifeng; Wang, Yongdong

2017-09-01

For electronic components, cyclic plastic strain makes it easier to accumulate fatigue damage than elastic strain. When the solder joints undertake thermal expansion or cold contraction, different thermal strain of the electronic component and its corresponding substrate is caused by the different coefficient of thermal expansion of the electronic component and its corresponding substrate, leading to the phenomenon of stress concentration. So repeatedly, cracks began to sprout and gradually extend [1]. In this paper, the typical thermal fatigue failure models of solder joints of electronic components are classified and the methods of obtaining the parameters in the model are summarized based on domestic and foreign literature research.

Raman spectroscopy of synovial fluid as a tool for diagnosing osteoarthritis

NASA Astrophysics Data System (ADS)

Esmonde-White, Karen A.; Mandair, Gurjit S.; Raaii, Farhang; Jacobson, Jon A.; Miller, Bruce S.; Urquhart, Andrew G.; Roessler, Blake J.; Morris, Michael D.

2009-05-01

For many years, viscosity has been the primary method used by researchers in rheumatology to assess the physiochemical properties of synovial fluid in both normal and osteoarthritic patients. However, progress has been limited by the lack of methods that provide multiple layers of information, use small sample volumes, and are rapid. Raman spectroscopy was used to assess the biochemical composition of synovial fluid collected from 40 patients with clinical evidence of knee osteoarthritis (OA) at the time of elective surgical treatment. Severity of knee osteoarthritis was assessed by a radiologist using Kellgren/Lawrence (K/L) scores from knee joint x rays, while light microscopy and Raman spectroscopy were used to examine synovial fluid (SF) aspirates (2 to 10 μL), deposited on fused silica slides. We show that Raman bands used to describe protein secondary structure and content can be used to detect changes in synovial fluid from osteoarthritic patients. Several Raman band intensity ratios increased significantly in spectra collected from synovial fluid in patients with radiological evidence of moderate-to-severe osteoarthritis damage. These ratios can be used to provide a ``yes/no'' damage assessment. These studies provide evidence that Raman spectroscopy would be a suitable candidate in the evaluation of joint damage in knee osteoarthritis patients.

Numerical and Experimental Evaluation on the Residual Stresses of Welded Joints

NASA Astrophysics Data System (ADS)

Huh, Sun Chul; Park, Wonjo; Yang, Haesug; Jung, Haeyoung; Kim, Chuyoung

Wings for the defense industry such as fighters, missiles, and rockets should show no deformation or damage on the structure. The structures of existing wings had holes for weight reduction. The plates and frames were fixed with rivets or screws, which limited the weight reduction possible. In this study, an improvement was made in jointing methods through EB welding and laser welding. Welding strength was measured through tension testing. In addition, finite element analysis was performed for the welding process so as to deduce the optimum welding condition.

Evaluation of traction stirrup distraction technique to increase the joint space of the shoulder joint in the dog: A cadaveric study.

PubMed

Devesa, V; Rovesti, G L; Urrutia, P G; Sanroman, F; Rodriguez-Quiros, J

2015-06-01

The objective of this study was to evaluate technical feasibility and efficacy of a joint distraction technique by traction stirrup to facilitate shoulder arthroscopy and assess potential soft tissue damage. Twenty shoulders were evaluated radiographically before distraction. Distraction was applied with loads from 40 N up to 200 N, in 40 N increments, and the joint space was recorded at each step by radiographic images. The effects of joint flexion and intra-articular air injection at maximum load were evaluated. Radiographic evaluation was performed after distraction to evaluate ensuing joint laxity. Joint distraction by traction stirrup technique produces a significant increase in the joint space; an increase in joint laxity could not be inferred by standard and stress radiographs. However, further clinical studies are required to evaluate potential neurovascular complications. A wider joint space may be useful to facilitate arthroscopy, reducing the likelihood for iatrogenic damage to intra-articular structures. Copyright © 2015 Elsevier Ltd. All rights reserved.

The beneficial effects of exercise on cartilage are lost in mice with reduced levels of ECSOD in tissues.

PubMed

Pate, Kathryn M; Sherk, Vanessa D; Carpenter, R Dana; Weaver, Michael; Crapo, Silvia; Gally, Fabienne; Chatham, Lillian S; Goldstrohm, David A; Crapo, James D; Kohrt, Wendy M; Bowler, Russell P; Oberley-Deegan, Rebecca E; Regan, Elizabeth A

2015-03-15

Osteoarthritis (OA) is associated with increased mechanical damage to joint cartilage. We have previously found that extracellular superoxide dismutase (ECSOD) is decreased in OA joint fluid and cartilage, suggesting oxidant damage may play a role in OA. We explored the effect of forced running as a surrogate for mechanical damage in a transgenic mouse with reduced ECSOD tissue binding. Transgenic mice heterozygous (Het) for the human ECSOD R213G polymorphism and 129-SvEv (wild-type, WT) mice were exposed to forced running on a treadmill for 45 min/day, 5 days/wk, over 8 wk. At the end of the running protocol, knee joint tissue was obtained for histology, immunohistochemistry, and protein analysis. Sedentary Het and WT mice were maintained for comparison. Whole tibias were studied for bone morphometry, finite element analysis, and mechanical testing. Forced running improved joint histology in WT mice. However, when ECSOD levels were reduced, this beneficial effect with running was lost. Het ECSOD runner mice had significantly worse histology scores compared with WT runner mice. Runner mice for both strains had increased bone strength in response to the running protocol, while Het mice showed evidence of a less robust bone structure in both runners and untrained mice. Reduced levels of ECSOD in cartilage produced joint damage when joints were stressed by forced running. The bone tissues responded to increased loading with hypertrophy, regardless of mouse strain. We conclude that ECSOD plays an important role in protecting cartilage from damage caused by mechanical loading. Copyright © 2015 the American Physiological Society.

Validation of automatic joint space width measurements in hand radiographs in rheumatoid arthritis

PubMed Central

Schenk, Olga; Huo, Yinghe; Vincken, Koen L.; van de Laar, Mart A.; Kuper, Ina H. H.; Slump, Kees C. H.; Lafeber, Floris P. J. G.; Bernelot Moens, Hein J.

2016-01-01

Abstract. Computerized methods promise quick, objective, and sensitive tools to quantify progression of radiological damage in rheumatoid arthritis (RA). Measurement of joint space width (JSW) in finger and wrist joints with these systems performed comparable to the Sharp–van der Heijde score (SHS). A next step toward clinical use, validation of precision and accuracy in hand joints with minimal damage, is described with a close scrutiny of sources of error. A recently developed system to measure metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints was validated in consecutive hand images of RA patients. To assess the impact of image acquisition, measurements on radiographs from a multicenter trial and from a recent prospective cohort in a single hospital were compared. Precision of the system was tested by comparing the joint space in mm in pairs of subsequent images with a short interval without progression of SHS. In case of incorrect measurements, the source of error was analyzed with a review by human experts. Accuracy was assessed by comparison with reported measurements with other systems. In the two series of radiographs, the system could automatically locate and measure 1003/1088 (92.2%) and 1143/1200 (95.3%) individual joints, respectively. In joints with a normal SHS, the average (SD) size of MCP joints was 1.7±0.2 and 1.6±0.3  mm in the two series of radiographs, and of PIP joints 1.0±0.2 and 0.9±0.2  mm. The difference in JSW between two serial radiographs with an interval of 6 to 12 months and unchanged SHS was 0.0±0.1  mm, indicating very good precision. Errors occurred more often in radiographs from the multicenter cohort than in a more recent series from a single hospital. Detailed analysis of the 55/1125 (4.9%) measurements that had a discrepant paired measurement revealed that variation in the process of image acquisition (exposure in 15% and repositioning in 57%) was a more frequent source of error than incorrect delineation by the software (25%). Various steps in the validation of an automated measurement system for JSW of MCP and PIP joints are described. The use of serial radiographs from different sources, with a short interval and limited damage, is helpful to detect sources of error. Image acquisition, in particular repositioning, is a dominant source of error. PMID:27921071

Numerical Simulation of Tension Properties for Al-Cu Alloy Friction Stir-Welded Joints with GTN Damage Model

NASA Astrophysics Data System (ADS)

Sun, Guo-Qin; Sun, Feng-Yang; Cao, Fang-Li; Chen, Shu-Jun; Barkey, Mark E.

2015-11-01

The numerical simulation of tensile fracture behavior on Al-Cu alloy friction stir-welded joint was performed with the Gurson-Tvergaard-Needleman (GTN) damage model. The parameters of the GTN model were studied in each region of the friction stir-welded joint by means of inverse identification. Based on the obtained parameters, the finite element model of the welded joint was built to predict the fracture behavior and tension properties. Good agreement can be found between the numerical and experimental results in the location of the tensile fracture and the mechanical properties.

Durability assessments of concrete using electrical properties and acoustic emission testing

NASA Astrophysics Data System (ADS)

Todak, Heather N.

Premature damage deterioration has been observed in pavement joints throughout the Midwestern region of the United States. Over time, severe joint damage creates a transportation safety concern and the necessary repairs can be an extreme economic burden. The deterioration is due in part to freeze-thaw damage associated with fluid accumulation at the pavement joints. This very preventable problem is an indication that current specifications and construction practices for freeze-thaw durability of concrete are inadequate. This thesis serves to create a better understanding of moisture ingress, freeze-thaw damage mechanisms, and the effect of variations in mixture properties on freeze-thaw behavior of concrete. The concepts of the nick point degree of saturation, sorptivity rates, and critical degree of saturation are discussed. These factors contribute to service life, defined in this study as the duration of time a concrete element remains below levels of critical saturation which are required for damage development to initiate. A theoretical model and a simple experimental procedure are introduced which help determine the nick point for a series of 32 concrete mixtures with unique mixture proportions and air entrainment properties. This simple experimental procedure is also presented as a method to measure important electrical properties in order to establish the formation factor, a valuable measure of concrete transport properties. The results of freeze-thaw testing with acoustic emission monitoring are presented to help understand and quantify damage development in concrete specimens when conditioned to various degrees of saturation. This procedure was used to study the relationship between air entrainment properties and the critical degree of saturation. Applying the concepts of degree of saturation and sorptivity, a performance-based model is proposed as a new approach to specifications for freeze-thaw durability. Finally, a conceptual model is presented to illustrate the effect of various changes in mixture proportions and air void properties on service life.

Smoking in combination with antibodies to cyclic citrullinated peptides is associated with persistently high levels of survivin in early rheumatoid arthritis: a prospective cohort study

PubMed Central

2014-01-01

Introduction High levels of the oncoprotein survivin may be detected in the majority of patients with early rheumatoid arthritis (RA). Survivin is a sensitive predictor of joint damage and persistent disease activity. Survivin-positive patients are often poor responders to antirheumatic and biological treatment. The aim of this study was to investigate the reproducibility of survivin status and its significance for clinical and immunological assessment of RA patients. Methods Survivin levels were measured in 339 patients from the Better Anti-Rheumatic FarmacOTherapy (BARFOT) cohort of early RA at baseline and after 24 months. The association of survivin status with joint damage (total Sharp-van der Heijde score), disease activity (Disease Activity Score based on evaluation of 28 joints (DAS28)), functional disability (Health Assessment Questionnaire (HAQ)), and pain perception (Visual Analogue Scale (VAS)) was calculated in the groups positive and negative for survivin on both occasions, and for the positive-negative and negative-positive groups. Results In 268 patients (79%) the levels of survivin were similar at baseline and after 24 months, 15% converted from survivin-positive to survivin-negative, and 5% from survivin-negative to survivin-positive. A combination of smoking and antibodies against cyclic citrullinated peptides (aCCP) predicted persistently (baseline and 24 months) high levels of survivin (odds ratio 4.36 (95% CI: 2.64 to 7.20), P < 0.001), positive predictive value 0.66 and specificity 0.83). The independent nature of survivin and aCCP was demonstrated by statistical and laboratory analysis. Survivin positivity on both test occasions was associated with the progression of joint damage, significantly higher DAS28 and lower rate of remission at 24 and 60 months compared to negative-negative patients. Survivin status was less associated with changes in HAQ and VAS. Conclusions Survivin is a relevant and reproducible marker of severe RA. Persistently high levels of survivin were associated with smoking and the presence of aCCP and/or RF antibodies and predicted persistent disease activity and joint damage. PMID:24428870

Damage prognosis of adhesively-bonded joints in laminated composite structural components of unmanned aerial vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrar, Charles R; Gobbato, Maurizio; Conte, Joel

2009-01-01

The extensive use of lightweight advanced composite materials in unmanned aerial vehicles (UAVs) drastically increases the sensitivity to both fatigue- and impact-induced damage of their critical structural components (e.g., wings and tail stabilizers) during service life. The spar-to-skin adhesive joints are considered one of the most fatigue sensitive subcomponents of a lightweight UAV composite wing with damage progressively evolving from the wing root. This paper presents a comprehensive probabilistic methodology for predicting the remaining service life of adhesively-bonded joints in laminated composite structural components of UAVs. Non-destructive evaluation techniques and Bayesian inference are used to (i) assess the current statemore » of damage of the system and, (ii) update the probability distribution of the damage extent at various locations. A probabilistic model for future loads and a mechanics-based damage model are then used to stochastically propagate damage through the joint. Combined local (e.g., exceedance of a critical damage size) and global (e.g.. flutter instability) failure criteria are finally used to compute the probability of component failure at future times. The applicability and the partial validation of the proposed methodology are then briefly discussed by analyzing the debonding propagation, along a pre-defined adhesive interface, in a simply supported laminated composite beam with solid rectangular cross section, subjected to a concentrated load applied at mid-span. A specially developed Eliler-Bernoulli beam finite element with interlaminar slip along the damageable interface is used in combination with a cohesive zone model to study the fatigue-induced degradation in the adhesive material. The preliminary numerical results presented are promising for the future validation of the methodology.« less

Association between -174G/C and -572G/C interleukin 6 gene polymorphisms and severe radiographic damage to the hands of Mexican patients with rheumatoid arthritis: a preliminary report.

PubMed

Zavaleta-Muñiz, S A; Gonzalez-Lopez, L; Murillo-Vazquez, J D; Saldaña-Cruz, A M; Vazquez-Villegas, M L; Martín-Márquez, B T; Vasquez-Jimenez, J C; Sandoval-Garcia, F; Ruiz-Padilla, A J; Fajardo-Robledo, N S; Ponce-Guarneros, J M; Rocha-Muñoz, A D; Alcaraz-Lopez, M F; Cardona-Müller, D; Totsuka-Sutto, S E; Rubio-Arellano, E D; Gamez-Nava, J I

2016-12-19

Several interleukin 6 gene (IL6) polymorphisms are implicated in susceptibility to rheumatoid arthritis (RA). It has not yet been established with certainty if these polymorphisms are associated with the severe radiographic damage observed in some RA patients, particularly those with the development of joint bone ankylosis (JBA). The objective of the present study was to evaluate the association between severe radiographic damage in hands and the -174G/C and -572G/C IL6 polymorphisms in Mexican Mestizo people with RA. Mestizo adults with RA and long disease duration (>5 years) were classified into two groups according to the radiographic damage in their hands: a) severe radiographic damage (JBA and/or joint bone subluxations) and b) mild or moderate radiographic damage. We compared the differences in genotype and allele frequencies of -174G/C and -572G/C IL6 polymorphisms (genotyped using polymerase chain reaction-restriction fragment length polymorphism) between these two groups. Our findings indicated that the -174G/C polymorphism of IL6 is associated with severe joint radiographic damage [maximum likelihood odds ratios (MLE_OR): 8.03; 95%CI 1.22-187.06; P = 0.03], whereas the -572G/C polymorphism of IL6 exhibited no such association (MLE_OR: 1.5; 95%CI 0.52-4.5; P = 0.44). Higher anti-cyclic citrullinated peptide antibody levels were associated with more severe joint radiographic damage (P = 0.04). We conclude that there is a relevant association between the -174G/C IL6 polymorphism and severe radiographic damage. Future studies in other populations are required to confirm our findings.

S100A8/A9, a potent serum and molecular imaging biomarker for synovial inflammation and joint destruction in seronegative experimental arthritis.

PubMed

Geven, Edwin J W; van den Bosch, Martijn H J; Di Ceglie, Irene; Ascone, Giuliana; Abdollahi-Roodsaz, Shahla; Sloetjes, Annet W; Hermann, Sven; Schäfers, Michael; van de Loo, Fons A J; van der Kraan, Peter M; Koenders, Marije I; Foell, Dirk; Roth, Johannes; Vogl, Thomas; van Lent, Peter L E M

2016-10-24

Seronegative joint diseases are characterized by a lack of well-defined biomarkers since autoantibodies are not elevated. Calprotectin (S100A8/A9) is a damage-associated molecular pattern (DAMP) which is released by activated phagocytes, and high levels are found in seronegative arthritides. In this study, we investigated the biomarker potential of systemic and local levels of these S100 proteins to assess joint inflammation and joint destruction in an experimental model for seronegative arthritis. Serum levels of S100A8/A9 and various cytokines were monitored during disease development in interleukin-1 receptor antagonist (IL-1Ra) -/- mice using ELISA and multiplex bead-based immunoassay, and were correlated to macroscopic and microscopic parameters for joint inflammation, bone erosion, and cartilage damage. Local expression of S100A8 and S100A9 and matrix metalloproteinase (MMP)-mediated cartilage damage in the ankle joints were investigated by immunohistochemistry. In addition, local S100A8 and activated MMPs were monitored in vivo by optical imaging using anti-S100A8-Cy7 and AF489-Cy5.5, a specific tracer for activated MMPs. Serum levels of S100A8/A9 were significantly increased in IL-1Ra -/- mice and correlated with macroscopic joint swelling and histological inflammation, while serum levels of pro-inflammatory cytokines did not correlate with joint swelling. In addition, early serum S100A8/A9 levels were prognostic for disease outcome at a later stage. The increased serum S100A8/A9 levels were reflected by an increased expression of S100A8 and S100A9 within the ankle joint, as visualized by molecular imaging. Next to inflammatory processes, serum S100A8/A9 also correlated with histological parameters for bone erosion and cartilage damage. In addition, arthritic IL-1Ra -/- mice with increased synovial S100A8 and S100A9 expression showed increased cartilage damage that coincided with MMP-mediated neoepitope expression and in vivo imaging of activated MMPs. Expression of S100A8 and S100A9 in IL-1Ra -/- mice strongly correlates with synovial inflammation, bone erosion, and cartilage damage, underlining the potential of S100A8/A9 as a systemic and local biomarker in seronegative arthritis not only for assessing inflammation but also for assessing severity of inflammatory joint destruction.

Robust control of multi-jointed arm with a decentralized autonomous control mechanism

NASA Technical Reports Server (NTRS)

Kimura, Shinichi; Miyazaki, Ken; Suzuki, Yoshiaki

1994-01-01

A decentralized autonomous control mechanism applied to the control of three dimensional manipulators and its robustness to partial damage was assessed by computer simulation. Decentralized control structures are believed to be quite robust to time delay between the operator and the target system. A 10-jointed manipulator based on our control mechanism was able to continue its positioning task in three-dimensional space without revision of the control program, even after some of its joints were damaged. These results suggest that this control mechanism can be effectively applied to space telerobots, which are associated with serious time delay between the operator and the target system, and which cannot be easily repaired after being partially damaged.

Study on Fatigue Performance of Composite Bolted Joints with Bolt-Hole Delamination

NASA Astrophysics Data System (ADS)

Liu, M. J.; Yu, S.; Zhao, Q. Y.

2018-03-01

Fatigue performance of composite structure with imperfections is a challenging subject at present. Based on cohesive zone method and multi-continuum theory, delamination evolution response and fatigue life prediction of a 3D composite single-lap joint with a bolt-hole have been investigated through computer codes Abaqus and Fe-safe. Results from the comparison of a perfect composite bolted joint with another defect one indicates that a relatively small delamination damage around the bolt hole brings about significant degradation of local material performance. More notably, fatigue life of stress concentration region of composite bolted joints is highly sensitive to external loads, as an increase of 67% cyclic load amplitude leads to an decrease of 99.5% local fatigue life in this study. However, the numerical strategy for solving composite fatigue problems is meaningful to engineering works.

Test Validation of the Repair to the Space Station Solar Alpha Rotary Joint

NASA Technical Reports Server (NTRS)

Allmon, Curtis; Wilkinson, Will; Loewenthal, Stu

2010-01-01

The Solar Array Alpha Joint Lubrication Interval Test (SARJ LITE) test rig was built as a method to evaluate the performance of the grease repair on the Starboard SARJ of the International Space Station (ISS) . The on-orbit SARJ was temporarily parked after receiving significant damage on one of its race ring surfaces as a result of inadequate lu brication (high dry contact friction) and unaccounted for roller traction kinematics. In a scaled down rig, flight-like roller bearings wer e preloaded and cycled on a nitrided 15-5 race surface. Grease was ad ded to the track and with instrumentation monitoring performance, trending data will be extracted and used to determine lubrication interva ls for both Port and Starboard ISS SARJ?s. The grease lubrication was found to be effective in eliminating the high friction that contributed to the onorbit race damage.

The cation channel Trpv2 is a new suppressor of arthritis severity, joint damage, and synovial fibroblast invasion.

PubMed

Laragione, Teresina; Cheng, Kai F; Tanner, Mark R; He, Mingzhu; Beeton, Christine; Al-Abed, Yousef; Gulko, Pércio S

2015-06-01

Little is known about the regulation of arthritis severity and joint damage in rheumatoid arthritis (RA). Fibroblast-like synoviocytes (FLS) have a central role in joint damage and express increased levels of the cation channel Trpv2. We aimed at determining the role of Trpv2 in arthritis. Treatment with Trpv2-specific agonists decreased the in vitro invasiveness of FLS from RA patients and arthritic rats and mice. Trpv2 stimulation suppressed IL-1β-induced expression of MMP-2 and MMP-3. Trpv2 agonists, including the new and more potent LER13, significantly reduced disease severity in KRN serum- and collagen-induced arthritis, and reduced histologic joint damage, synovial inflammation, and synovial blood vessel numbers suggesting anti-angiogenic activity. In this first in vivo use of Trpv2 agonists we discovered a new central role for Trpv2 in arthritis. These new compounds have the potential to become new therapies for RA and other diseases associated with inflammation, invasion, and angiogenesis. Copyright © 2015 Elsevier Inc. All rights reserved.

THE CATION CHANNEL TRPV2 IS A NEW SUPPRESSOR OF ARTHRITIS SEVERITY, JOINT DAMAGE AND SYNOVIAL FIBROBLAST INVASION

PubMed Central

Laragione, Teresina; Cheng, Kai F.; Tanner, Mark R.; He, Mingzhu; Beeton, Christine; Al-Abed, Yousef; Gulko, Pércio S.

2015-01-01

Little is known about the regulation of arthritis severity and joint damage in rheumatoid arthritis (RA). Fibroblast-like synoviocytes (FLS) have a central role in joint damage and express increased levels of the cation channel Trpv2. We aimed at determining the role of Trpv2 in arthritis. Treatment with Trpv2-specific agonists decreased the in vitro invasiveness of FLS from RA patients and arthritic rats and mice. Trpv2 stimulation suppressed IL-1β-induced expression of MMP-2 and MMP-3. Trpv2 agonists, including the new and more potent LER13, significantly reduced disease severity in KRN serum- and collagen-induced arthritis, and reduced histologic joint damage, synovial inflammation, and synovial blood vessel numbers suggesting anti-angiogenic activity. In this first in vivo use of Trpv2 agonists we discovered a new central role for Trpv2 in arthritis. These new compounds have the potential to become new therapies for RA and other diseases associated with inflammation, invasion and angiogenesis. PMID:25869297

Low Activation Joining of SiC/SiC Composites for Fusion Applications: Modeling Miniature Torsion Tests with Elastic and Elastic-Plastic Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.

2015-06-30

The international fusion community designed miniature torsion specimens for joint testing and irradiation in test reactors with limited irradiation volumes since SiC and SiC-composites used in fission or fusion environments require joining methods for assembling systems. Torsion specimens fail out-of-plane when joints are strong and when elastic moduli are comparable to SiC, which causes difficulties in determining shear strengths for many joints or for comparing unirradiated and irradiated joints. A finite element damage model was developed to treat elastic joints such as SiC/Ti3SiC2+SiC and elastic-plastic joints such as SiC/epoxy and steel/epoxy. The model uses constitutive shear data and is validatedmore » using epoxy joint data. The elastic model indicates fracture is likely to occur within the joined pieces to cause out-of-plane failures for miniature torsion specimens when a certain modulus and strength ratio between the joint material and the joined material exists. Lower modulus epoxy joints always fail in plane and provide good model validation.« less

Low Activation Joining of SiC/SiC Composites for Fusion Applications: Modeling Miniature Torsion Tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.

2014-06-30

The use of SiC and SiC-composites in fission or fusion environments appears to require joining methods for assembling systems. The international fusion community has designed miniature torsion specimens for joint testing and for irradiation in HFIR. Therefore, miniature torsion joints were fabricated using displacement reactions between Si and TiC to produce Ti3SiC2 + SiC joints with CVD-SiC that were tested in shear prior to and after HFIR irradiation. However, these torsion specimens fail out-of-plane, which causes difficulties in determining a shear strength for the joints or for comparing unirradiated and irradiated joints. A finite element damage model has been developedmore » that indicates fracture is likely to occur within the joined pieces to cause out-of-plane failures for miniature torsion specimens when a certain modulus and strength ratio between the joint material and the joined material exists. The implications for torsion shear joint data based on this sample design are discussed.« less

Spectrally formulated user-defined element in Abaqus for wave motion analysis and health monitoring of composite structures

NASA Astrophysics Data System (ADS)

Khalili, Ashkan

Wave propagation analysis in 1-D and 2-D composite structures is performed efficiently and accurately through the formulation of a User-Defined Element (UEL) based on the wavelet spectral finite element (WSFE) method. The WSFE method is based on the first order shear deformation theory which yields accurate results for wave motion at high frequencies. The wave equations are reduced to ordinary differential equations using Daubechies compactly supported, orthonormal, wavelet scaling functions for approximations in time and one spatial dimension. The 1-D and 2-D WSFE models are highly efficient computationally and provide a direct relationship between system input and output in the frequency domain. The UEL is formulated and implemented in Abaqus for wave propagation analysis in composite structures with complexities. Frequency domain formulation of WSFE leads to complex valued parameters, which are decoupled into real and imaginary parts and presented to Abaqus as real values. The final solution is obtained by forming a complex value using the real number solutions given by Abaqus. Several numerical examples are presented here for 1-D and 2-D composite waveguides. Wave motions predicted by the developed UEL correlate very well with Abaqus simulations using shear flexible elements. The results also show that the UEL largely retains computational efficiency of the WSFE method and extends its ability to model complex features. An enhanced cross-correlation method (ECCM) is developed in order to accurately predict damage location in plates. Three major modifications are proposed to the widely used cross-correlation method (CCM) to improve damage localization capabilities, namely actuator-sensor configuration, signal pre-processing method, and signal post-processing method. The ECCM is investigated numerically (FEM simulation) and experimentally. Experimental investigations for damage detection employ a PZT transducer as actuator and laser Doppler vibrometer as sensor. Both numerical and experimental results show that the developed method is capable of damage localization with high precision. Further, ECCM is used to detect and localize debonding in a composite material skin-stiffener joint. The UEL is used to represent the healthy case whereas the damaged case is simulated using Abaqus. It is shown that the ECCM successfully detects the location of the debond in the skin-stiffener joint.

Change of synovial vascularity in a single finger joint assessed by power doppler sonography correlated with radiographic change in rheumatoid arthritis: comparative study of a novel quantitative score with a semiquantitative score.

PubMed

Fukae, Jun; Kon, Yujiro; Henmi, Mihoko; Sakamoto, Fumihiko; Narita, Akihiro; Shimizu, Masato; Tanimura, Kazuhide; Matsuhashi, Megumi; Kamishima, Tamotsu; Atsumi, Tatsuya; Koike, Takao

2010-05-01

To investigate the relationship between synovial vascularity assessed by quantitative power Doppler sonography (PDS) and progression of structural bone damage in a single finger joint in patients with rheumatoid arthritis (RA). We studied 190 metacarpophalangeal (MCP) joints and 190 proximal interphalangeal (PIP) joints of 19 patients with active RA who had initial treatment with disease-modifying antirheumatic drugs (DMARDs). Patients were examined by clinical and laboratory assessments throughout the study. Hand and foot radiography was performed at baseline and the twentieth week. Magnetic resonance imaging (MRI) was performed at baseline. PDS was performed at baseline and the eighth week. Synovial vascularity was evaluated according to both quantitative and semiquantitative methods. Quantitative PDS was significantly correlated with the enhancement rate of MRI in each single finger joint. Comparing quantitative synovial vascularity and radiographic change in single MCP or PIP joints, the level of vascularity at baseline showed a significant positive correlation with radiographic progression at the twentieth week. The change of vascularity in response to DMARDs, defined as the percentage change in vascularity by the eighth week from baseline, was inversely correlated with radiographic progression in each MCP joint. The quantitative PDS method was more useful than the semiquantitative method for the evaluation of synovial vascularity in a single finger joint. The change of synovial vascularity in a single finger joint determined by quantitative PDS could numerically predict its radiographic progression. Using vascularity as a guide to consider a therapeutic approach would have benefits for patients with active RA.

Sustained inhibition of progressive joint damage with rituximab plus methotrexate in early active rheumatoid arthritis: 2-year results from the randomised controlled trial IMAGE.

PubMed

Tak, Paul P; Rigby, William; Rubbert-Roth, Andrea; Peterfy, Charles; van Vollenhoven, Ronald F; Stohl, William; Healy, Emma; Hessey, Eva; Reynard, Mark; Shaw, Tim

2012-03-01

In the IMAGEstudy, rituximab plus methotrexate (MTX) inhibited joint damage and improved clinical outcomes at 1 year in MTX-naïve patients with early active rheumatoid arthritis. The aim of this study was to assess joint damage progression and clinical outcomes over 2 years. Patients (n=755) were randomised to receive rituximab 2×500 mg+MTX, 2×1000 mg+MTX or placebo+MTX. The placebo-controlled period continued to week 104. Two-year end points were defined as secondary or exploratory and included change in total Genant-modified Sharp score (mTSS), total erosion score and joint space narrowing score from baseline to week 104. Clinical efficacy and physical function end points were also assessed. At 2 years, rituximab 2×1000 mg+MTX maintained inhibition of progressive joint damage versus MTX alone (mTSS change 0.41 vs 1.95; p<0.0001 (79% inhibition)), and a higher proportion of patients receiving rituximab 2×1000 mg+MTX had no radiographic progression over 2 years compared with those receiving MTX alone (57% vs 37%; p<0.0001). Contrary to 1-year results, exploratory analysis of rituximab 2×500 mg+MTX at 2 years showed that progressive joint damage was slowed by ∼61% versus placebo+MTX (mTSS, exploratory p=0.0041). Improvements in clinical signs and symptoms and physical function seen after 1 year in rituximab-treated patients versus those receiving placebo were maintained at year 2. Safety profiles were similar between groups. Treatment with rituximab 2×1000 mg+MTX was associated with sustained improvements in radiographic, clinical and functional outcomes over 2 years. Clinical trials.gov identifier NCT00299104.

Arthritis

MedlinePlus

... or have trouble moving around, you might have arthritis. Most kinds of arthritis cause pain and swelling in your joints. Joints ... joint can become severely damaged. Some kinds of arthritis can also cause problems in your organs, such ...

A Patient-Specific Foot Model for the Estimate of Ankle Joint Forces in Patients with Juvenile Idiopathic Arthritis.

PubMed

Prinold, Joe A I; Mazzà, Claudia; Di Marco, Roberto; Hannah, Iain; Malattia, Clara; Magni-Manzoni, Silvia; Petrarca, Maurizio; Ronchetti, Anna B; Tanturri de Horatio, Laura; van Dijkhuizen, E H Pieter; Wesarg, Stefan; Viceconti, Marco

2016-01-01

Juvenile idiopathic arthritis (JIA) is the leading cause of childhood disability from a musculoskeletal disorder. It generally affects large joints such as the knee and the ankle, often causing structural damage. Different factors contribute to the damage onset, including altered joint loading and other mechanical factors, associated with pain and inflammation. The prediction of patients' joint loading can hence be a valuable tool in understanding the disease mechanisms involved in structural damage progression. A number of lower-limb musculoskeletal models have been proposed to analyse the hip and knee joints, but juvenile models of the foot are still lacking. This paper presents a modelling pipeline that allows the creation of juvenile patient-specific models starting from lower limb kinematics and foot and ankle MRI data. This pipeline has been applied to data from three children with JIA and the importance of patient-specific parameters and modelling assumptions has been tested in a sensitivity analysis focused on the variation of the joint reaction forces. This analysis highlighted the criticality of patient-specific definition of the ankle joint axes and location of the Achilles tendon insertions. Patient-specific detection of the Tibialis Anterior, Tibialis Posterior, and Peroneus Longus origins and insertions were also shown to be important.

The Role of High-resolution Peripheral Quantitative Computed Tomography as a Biomarker for Joint Damage in Inflammatory Arthritis.

PubMed

Tam, Lai-Shan

2016-10-01

Since 2011, members of the SPECTRA Collaboration (Study grouP for xtrEme-Computed Tomography in Rheumatoid Arthritis) have investigated the validity, reliability, and responsiveness of high-resolution peripheral quantitative computed tomography (HR-pQCT) as a biomarker for joint damage in inflammatory arthritis. Presented in this series of articles are a systematic review of HR-pQCT-related findings to date, a review of selected images of cortical and subchondral trabecular bone of metacarpophalangeal (MCP) joints, results of a consensus process to standardize the definition of erosions and their quantification, as well as an examination of the effect of joint flexion on width and volume assessment of the joint space.

Physiotherapy in Rheumatoid Arthritis

PubMed Central

Kavuncu, Vural; Evcik, Deniz

2004-01-01

Rheumatoid arthritis (RA) is a chronic and painful clinical condition that leads to progressive joint damage, disability, deterioration in quality of life, and shortened life expectancy. Even mild inflammation may result in irreversible damage and permanent disability. The clinical course according to symptoms may be either intermittent or progressive in patients with RA. In most patients, the clinical course is progressive, and structural damage develops in the first 2 years. The aim of RA management is to achieve pain relief and prevent joint damage and functional loss. Physiotherapy and rehabilitation applications significantly augment medical therapy by improving the management of RA and reducing handicaps in daily living for patients with RA. In this review, the application of physiotherapy modalities is examined, including the use of cold/heat applications, electrical stimulation, and hydrotherapy. Rehabilitation treatment techniques for patients with RA such as joint protection strategies, massage, exercise, and patient education are also presented. PMID:15266230

Modeling thermal and irradiation-induced swelling effects on the integrity of Ti 3 SiC 2 /SiC joints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Ba Nghiep; Henager, Charles H.; Kurtz, Richard J.

Previously, results for CVD-SiC joints created using solid state displacement reactions to form a dual-phase SiC/MAX phase irradiated at 800°C and 5 dpa indicated some extent of cracking in the joint and along the CVD-SiC/joint interface. This paper elucidates the origin of cracking by thermomechanical modeling combined with irradiation-induced swelling effects using a continuum damage approach with support of micromechanical modeling. Three irradiation temperatures (400°C, 500°C and 800°C) are considered assuming experimental irradiation doses in a range leading to saturation swelling in SiC. The analyses indicate that a SiC/MAX joint heated to 400°C fails during irradiation-induced swelling at this temperaturemore » while it experiences some damage after being heated to 500°C and irradiated at the same temperature. However, it fails during cooling from 500°C to room temperature. The joint experiences minor damage when heated to and irradiated at 800°C but does not fail after cooling. The prediction agrees with the experimental findings available for this case.« less

Kinetics of Accumulation of Damage in Surface Layers of Lithium-Containing Aluminum Alloys in Fatigue Tests with Rigid Loading Cycle and Corrosive Effect of Environment

NASA Astrophysics Data System (ADS)

Morozova, L. V.; Zhegina, I. P.; Grigorenko, V. B.; Fomina, M. A.

2017-07-01

High-resolution methods of metal physics research including electron, laser and optical microscopy are used to study the kinetics of the accumulation of slip lines and bands and the corrosion damage in the plastic zone of specimens of aluminum-lithium alloys 1441 and B-1469 in rigid-cycle fatigue tests under the joint action of applied stresses and corrosive environment. The strain parameters (the density of slip bands, the sizes of plastic zones near fracture, the surface roughness in singled-out zones) and the damage parameters (the sizes of pits and the pitting area) are evaluated.

Risk factors for cartilage damage and osteoarthritis of the elbow joint: case-control study and systematic literature review.

PubMed

Spahn, Gunter; Lipfert, Jens Uwe; Maurer, Constance; Hartmann, Bernd; Schiele, Rainer; Klemm, Holm-Torsten; Grifka, Joachim; Hofmann, Gunther O

2017-04-01

This case-control study compares patients with healthy elbows to a group of symptomatic patients with cartilage damage/osteoarthritis. The control group (n = 126) was recruited during routine medical examinations of patients (general medical offices). Included in the case group were a total of 92 patients who were undergoing arthroscopy as a result of chronic elbow discomfort. All patients were questioned with regard to occupational stress and athletic stress. A significantly increased risk of cartilage damage/osteoarthritis was found with subjectively perceived increased stress in occupational settings: OR = 3.8 (95% CI 2.1-6.7); p < 0.001; for the individual stresses of the elbow joint in occupational settings, the following severities in effects were found: Exposure to heavy work OR = 3.9 (95% CI 2.2-6.8); Force OR = 3.7 (95% CI 2.1-6.5); Vibration OR = 4.6 (95% CI 2.5-8.5); Repetition OR = 9.2 (95% CI 3.6-23.3); p < 0.001. Elbow-stressing sport types represent a potential risk factor for the development of cartilage damage/osteoarthritis of the elbow joint: OR = 2.5 (95% CI 1.3-4.7); p = 0.003. Cartilage damage/radiographic osteoarthritis of the elbow joint are rare with respect to the overall prevalence of osteoarthritis. In the large number of patients with cartilage damage/radiographic osteoarthritis of the elbow joint, occupational or athletic stress factors and injuries sustained, in addition to other causes (rheumatism, gout), can prove as possible causes of these as secondary to symptomatic forms of osteoarthritis.

Audio-based bolt-loosening detection technique of bolt joint

NASA Astrophysics Data System (ADS)

Zhang, Yang; Zhao, Xuefeng; Su, Wensheng; Xue, Zhigang

2018-03-01

Bolt joint, as the commonest coupling structure, is widely used in electro-mechanical system. However, it is the weakest part of the whole system. The increase of preload tension force can raise the reliability and strength of the bolt joint. Therefore, the pretension force is one of the most important factors to ensure the stability of bolt joint. According to the way of generating pretension force, the pretension force can be monitored by bolt torque, degrees and elongation. The existing bolt-loosening monitoring methods all require expensive equipment, which greatly restricts the practicality of the bolt-loosening monitoring. In this paper, a new method of bolt-loosening detection technique based on audio is proposed. The sound that bolt is hit by a hammer is recorded on the Smartphone, and the collected audio signal is classified and identified by support vector machine algorithm. First, a verification test was designed and the results show that this new method can identify the damage of bolt looseness accurately. Second, a variety of bolt-loosening was identified. The results indicate that this method has a high accuracy in multiclass classification of the bolt looseness. This bolt-loosening detection technique based on audio not only can reduce the requirements of technical and professional experience, but also make bolt-loosening monitoring simpler and easier.

Segmentation and determination of joint space width in foot radiographs

NASA Astrophysics Data System (ADS)

Schenk, O.; de Muinck Keizer, D. M.; Bernelot Moens, H. J.; Slump, C. H.

2016-03-01

Joint damage in rheumatoid arthritis is frequently assessed using radiographs of hands and feet. Evaluation includes measurements of the joint space width (JSW) and detection of erosions. Current visual scoring methods are timeconsuming and subject to inter- and intra-observer variability. Automated measurement methods avoid these limitations and have been fairly successful in hand radiographs. This contribution aims at foot radiographs. Starting from an earlier proposed automated segmentation method we have developed a novel model based image analysis algorithm for JSW measurements. This method uses active appearance and active shape models to identify individual bones. The model compiles ten submodels, each representing a specific bone of the foot (metatarsals 1-5, proximal phalanges 1-5). We have performed segmentation experiments using 24 foot radiographs, randomly selected from a large database from the rheumatology department of a local hospital: 10 for training and 14 for testing. Segmentation was considered successful if the joint locations are correctly determined. Segmentation was successful in only 14%. To improve results a step-by-step analysis will be performed. We performed JSW measurements on 14 randomly selected radiographs. JSW was successfully measured in 75%, mean and standard deviation are 2.30+/-0.36mm. This is a first step towards automated determination of progression of RA and therapy response in feet using radiographs.

Structural health management of aerospace hotspots under fatigue loading

NASA Astrophysics Data System (ADS)

Soni, Sunilkumar

Sustainability and life-cycle assessments of aerospace systems, such as aircraft structures and propulsion systems, represent growing challenges in engineering. Hence, there has been an increasing demand in using structural health monitoring (SHM) techniques for continuous monitoring of these systems in an effort to improve safety and reduce maintenance costs. The current research is part of an ongoing multidisciplinary effort to develop a robust SHM framework resulting in improved models for damage-state awareness and life prediction, and enhancing capability of future aircraft systems. Lug joints, a typical structural hotspot, were chosen as the test article for the current study. The thesis focuses on integrated SHM techniques for damage detection and characterization in lug joints. Piezoelectric wafer sensors (PZTs) are used to generate guided Lamb waves as they can be easily used for onboard applications. Sensor placement in certain regions of a structural component is not feasible due to the inaccessibility of the area to be monitored. Therefore, a virtual sensing concept is introduced to acquire sensor data from finite element (FE) models. A full three dimensional FE analysis of lug joints with piezoelectric transducers, accounting for piezoelectrical-mechanical coupling, was performed in Abaqus and the sensor signals were simulated. These modeled sensors are called virtual sensors. A combination of real data from PZTs and virtual sensing data from FE analysis is used to monitor and detect fatigue damage in aluminum lug joints. Experiments were conducted on lug joints under fatigue loads and sensor signals collected were used to validate the simulated sensor response. An optimal sensor placement methodology for lug joints is developed based on a detection theory framework to maximize the detection rate and minimize the false alarm rate. The placement technique is such that the sensor features can be directly correlated to damage. The technique accounts for a number of factors, such as actuation frequency and strength, minimum damage size, damage detection scheme, material damping, signal to noise ratio and sensing radius. Advanced information processing methodologies are discussed for damage diagnosis. A new, instantaneous approach for damage detection, localization and quantification is proposed for applications to practical problems associated with changes in reference states under different environmental and operational conditions. Such an approach improves feature extraction for state awareness, resulting in robust life prediction capabilities.

A Fatigue Crack Size Evaluation Method Based on Lamb Wave Simulation and Limited Experimental Data

PubMed Central

He, Jingjing; Ran, Yunmeng; Liu, Bin; Yang, Jinsong; Guan, Xuefei

2017-01-01

This paper presents a systematic and general method for Lamb wave-based crack size quantification using finite element simulations and Bayesian updating. The method consists of construction of a baseline quantification model using finite element simulation data and Bayesian updating with limited Lamb wave data from target structure. The baseline model correlates two proposed damage sensitive features, namely the normalized amplitude and phase change, with the crack length through a response surface model. The two damage sensitive features are extracted from the first received S0 mode wave package. The model parameters of the baseline model are estimated using finite element simulation data. To account for uncertainties from numerical modeling, geometry, material and manufacturing between the baseline model and the target model, Bayesian method is employed to update the baseline model with a few measurements acquired from the actual target structure. A rigorous validation is made using in-situ fatigue testing and Lamb wave data from coupon specimens and realistic lap-joint components. The effectiveness and accuracy of the proposed method is demonstrated under different loading and damage conditions. PMID:28902148

Lamb wave propagation in a restricted geometry composite pi-joint specimen

NASA Astrophysics Data System (ADS)

Blackshire, James L.; Soni, Som

2012-05-01

The propagation of elastic waves in a material can involve a number of complex physical phenomena, resulting in both subtle and dramatic effects on detected signal content. In recent years, the use of advanced methods for characterizing and imaging elastic wave propagation and scattering processes has increased, where for example the use of scanning laser vibrometry and advanced computational models have been used very effectively to identify propagating modes, scattering phenomena, and damage feature interactions. In the present effort, the propagation of Lamb waves within a narrow, constrained geometry composite pi-joint structure are studied using 3D finite element models and scanning laser vibrometry measurements, where the effects of varying sample thickness, complex joint curvatures, and restricted structure geometries are highlighted, and a direct comparison of computational and experimental results are provided for simulated and realistic geometry composite pi-joint samples.

Evolution of the Deformation Behavior of Sn-Rich Solders during Cyclic Fatigue

NASA Astrophysics Data System (ADS)

Wentlent, Luke Arthur

Continuous developments in the electronics industry have provided a critical need for a quantitative, fundamental understanding of the behavior of SnAgCu (SAC) solders in both isothermal and thermal fatigue conditions. This study examines the damage behavior of Sn-based solders in a constant amplitude and variable amplitude environment. In addition, damage properties are correlated with crystal orientation and slip behavior. Select solder joints were continuously characterized and tested repeatedly in order to eliminate the joint to joint variation due to the anisotropy of beta-Sn. Characterization was partitioned into three different categories: effective properties and slip behavior, creep mechanisms and crystal morphology development, and atomic behavior and evolution. Active slip systems were correlated with measured properties. Characterization of the mechanical behavior was performed by the calculation and extrapolation of the elastic modulus, work, effective stiffness, Schmid factors, and time-dependent plasticity (creep). Electron microscopy based characterization methods included Scanning Electron Microscopy (SEM), Electron Backscattering Diffraction (EBSD), and Transmission Electron Microscopy (TEM). Testing showed a clear evolution of the steady-state creep mechanism when the cycling amplitudes were varied, from dislocation controlled to diffusion controlled creep. Dislocation behavior was examined and shown to evolve differently in single amplitude vs. variable amplitude testing. Finally, the mechanism of the recrystallization behavior of the beta-Sn was observed. This work fills a gap in the literature, providing a systematic study which identifies how the damage behavior in Sn-alloys depends upon the previous damage. A link is made between the observed creep behavior and the dislocation observations, providing a unified picture. Information developed in this work lays a stepping stone to future fundamental analyses as well as clarifying aspects of the mechanistic behavior of Sn and Sn-based alloys.

Distinguishing erosive osteoarthritis and calcium pyrophosphate deposition disease.

PubMed

Rothschild, Bruce M

2013-04-18

Erosive osteoarthritis is a term utilized to describe a specific inflammatory condition of the interphalangeal and first carpal metacarpal joints of the hands. The term has become a part of medical philosophical semantics and paradigms, but the issue is actually more complicated. Even the term osteoarthritis (non-erosive) has been controversial, with some suggesting osteoarthrosis to be more appropriate in view of the perspective that it is a non-inflammatory process undeserving of the "itis" suffix. The term "erosion" has also been a source of confusion in osteoarthritis, as it has been used to describe cartilage, not bone lesions. Inflammation in individuals with osteoarthritis actually appears to be related to complicating phenomena, such as calcium pyrophosphate and hydroxyapatite crystal deposition producing arthritis. Erosive osteoarthritis is the contentious term. It is used to describe a specific form of joint damage to specific joints. The damage has been termed erosions and the distribution of the damage is to the interphalangeal joints of the hand and first carpal metacarpal joint. Inflammation is recognized by joint redness and warmth, while X-rays reveal alteration of the articular surfaces, producing a smudged appearance. This ill-defined, joint damage has a crumbling appearance and is quite distinct from the sharply defined erosions of rheumatoid arthritis and spondyloarthropathy. The appearance is identical to those found with calcium pyrophosphate deposition disease, both in character and their unique responsiveness to hydroxychloroquine treatment. Low doses of the latter often resolve symptoms within weeks, in contrast to higher doses and the months required for response in other forms of inflammatory arthritis. Reconsidering erosive osteoarthritis as a form of calcium pyrophosphate deposition disease guides physicians to more effective therapeutic intervention.

Distinguishing erosive osteoarthritis and calcium pyrophosphate deposition disease

PubMed Central

Rothschild, Bruce M

2013-01-01

Erosive osteoarthritis is a term utilized to describe a specific inflammatory condition of the interphalangeal and first carpal metacarpal joints of the hands. The term has become a part of medical philosophical semantics and paradigms, but the issue is actually more complicated. Even the term osteoarthritis (non-erosive) has been controversial, with some suggesting osteoarthrosis to be more appropriate in view of the perspective that it is a non-inflammatory process undeserving of the “itis” suffix. The term “erosion” has also been a source of confusion in osteoarthritis, as it has been used to describe cartilage, not bone lesions. Inflammation in individuals with osteoarthritis actually appears to be related to complicating phenomena, such as calcium pyrophosphate and hydroxyapatite crystal deposition producing arthritis. Erosive osteoarthritis is the contentious term. It is used to describe a specific form of joint damage to specific joints. The damage has been termed erosions and the distribution of the damage is to the interphalangeal joints of the hand and first carpal metacarpal joint. Inflammation is recognized by joint redness and warmth, while X-rays reveal alteration of the articular surfaces, producing a smudged appearance. This ill-defined, joint damage has a crumbling appearance and is quite distinct from the sharply defined erosions of rheumatoid arthritis and spondyloarthropathy. The appearance is identical to those found with calcium pyrophosphate deposition disease, both in character and their unique responsiveness to hydroxychloroquine treatment. Low doses of the latter often resolve symptoms within weeks, in contrast to higher doses and the months required for response in other forms of inflammatory arthritis. Reconsidering erosive osteoarthritis as a form of calcium pyrophosphate deposition disease guides physicians to more effective therapeutic intervention. PMID:23610748

Computational Methods for Failure Analysis and Life Prediction

NASA Technical Reports Server (NTRS)

Noor, Ahmed K. (Compiler); Harris, Charles E. (Compiler); Housner, Jerrold M. (Compiler); Hopkins, Dale A. (Compiler)

1993-01-01

This conference publication contains the presentations and discussions from the joint UVA/NASA Workshop on Computational Methods for Failure Analysis and Life Prediction held at NASA Langley Research Center 14-15 Oct. 1992. The presentations focused on damage failure and life predictions of polymer-matrix composite structures. They covered some of the research activities at NASA Langley, NASA Lewis, Southwest Research Institute, industry, and universities. Both airframes and propulsion systems were considered.

Inhibition of joint damage and improved clinical outcomes with rituximab plus methotrexate in early active rheumatoid arthritis: the IMAGE trial.

PubMed

Tak, P P; Rigby, W F; Rubbert-Roth, A; Peterfy, C G; van Vollenhoven, R F; Stohl, W; Hessey, E; Chen, A; Tyrrell, H; Shaw, T M

2011-01-01

Rituximab is an effective treatment in patients with established rheumatoid arthritis (RA). The objective of the IMAGE study was to determine the efficacy of rituximab in the prevention of joint damage and its safety in combination with methotrexate (MTX) in patients initiating treatment with MTX. In this double-blind randomised controlled phase III study, 755 MTX-naïve patients with active RA were randomly assigned to MTX alone, rituximab 2×500 mg + MTX or rituximab 2×1000 mg + MTX. The primary end point at week 52 was the change in joint damage measured using a Genant-modified Sharp score. 249, 249 and 250 patients were randomly assigned to MTX alone, rituximab 2×500 mg + MTX or rituximab 2×1000 mg + MTX, respectively. At week 52, treatment with rituximab 2×1000 mg + MTX compared with MTX alone was associated with a reduction in progression of joint damage (mean change in total modified Sharp score 0.359 vs 1.079; p=0.0004) and an improvement in clinical outcomes (ACR50 65% vs 42%; p<0.0001); rituximab 2×500 mg + MTX improved clinical outcomes (ACR50 59% vs 42%; p<0.0001) compared with MTX alone but did not significantly reduce the progression of joint damage. Safety outcomes were similar between treatment groups. Treatment with rituximab 2×1000 mg in combination with MTX is an effective therapy for the treatment of patients with MTX-naïve RA. ClinicalTrials.gov identifier NCT00299104.

Evaluation of Longitudinal Joints of HMA Pavements in Tennessee

DOT National Transportation Integrated Search

2010-05-01

Longitudinal joints between lanes of hot-mix asphalt (HMA) pavements are commonly susceptible to moisture damage and other failures. In 2006, the Tennessee Department of Transportation (TDOT) identified longitudinal joint failure as one of the major ...

The lexicon of polyethylene wear in artificial joints.

PubMed

McKellop, Harry A

2007-12-01

The analysis of wear on polyethylene components that have been retrieved after use in patients has provided invaluable understanding of how wear occurs in vivo, and how it may be minimized through improved materials and implant design. The great number of such studies that have been published over the past three decades has lead to an extensive vocabulary to describe the tribology of prosthetic joints. However, these also have led to some confusion, due to the occasional misuse of terms from classical tribology, along with the use of multiple terms to describe the same wear phenomenon, and vice versa. The author has proposed that our understanding of wear in artificial joints may be enhanced by recognizing that there are four general subject areas: Modes, Mechanisms, Damage and Debris. Wear Mode 1 occurs when the two bearing surfaces are articulating against each other in the manner intended by the implant designer. Mode 2 occurs when a bearing surface articulates against a non-bearing surface. Mode 3 occurs when third-body abrasive particles have become entrapped between the two bearing surfaces, and Mode 4 occurs when two non-bearing surfaces are wearing against each other. The least wear occurs in Mode 1, whereas severe wear typically occurs in Modes 2, 3 and 4. The classical wear mechanisms that apply to prosthetic joints include adhesion, abrasion and fatigue. These can occur in varying amounts in either of the four wear modes. As used in the literature for the past three decades, wear "damage" can best be defined as the change surface texture or morphology that is caused by the action of the wear mechanisms. Although a wide variety of terms have been used, an overview of the literature indicates that about eight terms have been sufficient to describe the types of damage that occur on retrieved polyethylene components, i.e., burnishing, abrasion, scratches, plastic deformation, cracks, pits, delamination, and embedded third bodies. The author suggests that, as far as possible, investigators endeavor to limit their descriptions of surface damage to these terms and, importantly, to clearly and consistently distinguish the classical wear mechanisms from the types of damage produced by those mechanisms. Wear debris refers to the billions of particles, some measuring in nanometers, that are generated by the wear mechanisms, and that initiate biological reactions, such as osteolysis, that may lead to the failure of the implant. As the methods for recovering wear debris from joint fluids and tissues are improved, investigators are using a growing number of terms to describe them. As with the types of damage, it will be important in the coming years to maximize clarity and minimize redundancy of the vocabulary in this important area of research.

Early osteoarthritis of the patellofemoral joint.

PubMed

Arendt, Elizabeth A; Berruto, Massimo; Filardo, Giuseppe; Ronga, Mario; Zaffagnini, Stefano; Farr, Jack; Ferrua, Paolo; Grassi, Alberto; Condello, Vincenzo

2016-06-01

Patellofemoral joint cartilage lesions are associated with a variety of clinical situations including blunt trauma, lateral patella dislocations, or as a secondary development in the setting of abnormal joint loading. There is a need for more clarity on how to best address these lesions. Most specifically, when is it necessary to surgically treat these lesions of the patella and trochlea and which technique to use? This review will focus on the spectrum of patellofemoral disease/injury and their treatment strategies, with special emphasis on cartilage damage and early osteoarthritis. Chapter sections will review the most common scenarios of cartilage damage in the patellofemoral joint, with an attempt to summarize current treatment, their outcomes, remaining challenges and unanswered questions.

An accurate fatigue damage model for welded joints subjected to variable amplitude loading

NASA Astrophysics Data System (ADS)

Aeran, A.; Siriwardane, S. C.; Mikkelsen, O.; Langen, I.

2017-12-01

Researchers in the past have proposed several fatigue damage models to overcome the shortcomings of the commonly used Miner’s rule. However, requirements of material parameters or S-N curve modifications restricts their practical applications. Also, application of most of these models under variable amplitude loading conditions have not been found. To overcome these restrictions, a new fatigue damage model is proposed in this paper. The proposed model can be applied by practicing engineers using only the S-N curve given in the standard codes of practice. The model is verified with experimentally derived damage evolution curves for C 45 and 16 Mn and gives better agreement compared to previous models. The model predicted fatigue lives are also in better correlation with experimental results compared to previous models as shown in earlier published work by the authors. The proposed model is applied to welded joints subjected to variable amplitude loadings in this paper. The model given around 8% shorter fatigue lives compared to Eurocode given Miner’s rule. This shows the importance of applying accurate fatigue damage models for welded joints.

Infliximab in active early rheumatoid arthritis

PubMed Central

Breedveld, F; Emery, P; Keystone, E; Patel, K; Furst, D; Kalden, J; St, C; Weisman, M; Smolen, J; Lipsky, P; Maini, R

2004-01-01

Objective: To examine the impact of the combination of infliximab plus methotrexate (MTX) on the progression of structural damage in patients with early rheumatoid arthritis (RA). Methods: Subanalyses were carried out on data for patients with early RA in the Anti-TNF Therapy in RA with Concomitant Therapy (ATTRACT) study, in which 428 patients with active RA despite MTX therapy received placebo with MTX (MTX-only) or infliximab 3 mg/kg or 10 mg/kg every (q) 4 or 8 weeks with MTX (infliximab plus MTX) for 102 weeks. Early RA was defined as disease duration of 3 years or less; 82 of the 428 patients (19%) met this definition. Structural damage was assessed with the modified van der Heijde-Sharp score. The changes from baseline to week 102 in total modified van der Heijde-Sharp score were compared between the infliximab plus MTX groups and the MTX-only group. Results: The erosion and joint space narrowing scores from baseline to week 102 in the cohort of patients with early RA decreased significantly in each infliximab dose regimen compared with the MTX-only regimen. Consistent benefit was seen in the joints of both hands and feet. Conclusions: Infliximab combined with MTX inhibited the progression of structural damage in patients with early RA during the 2 year period of treatment. Early intervention with infliximab in patients with active RA despite MTX therapy may provide long term benefits by preventing radiographic progression and preserving joint integrity. PMID:14722203

Assessment of congruence and impingement of the hip joint in professional ballet dancers: a motion capture study.

PubMed

Charbonnier, Caecilia; Kolo, Frank C; Duthon, Victoria B; Magnenat-Thalmann, Nadia; Becker, Christoph D; Hoffmeyer, Pierre; Menetrey, Jacques

2011-03-01

Early hip osteoarthritis in dancers could be explained by femoroacetabular impingements. However, there is a lack of validated noninvasive methods and dynamic studies to ascertain impingement during motion. Moreover, it is unknown whether the femoral head and acetabulum are congruent in typical dancing positions. The practice of some dancing movements could cause a loss of hip joint congruence and recurrent impingements, which could lead to early osteoarthritis. Descriptive laboratory study. Eleven pairs of female dancer's hips were motion captured with an optical tracking system while performing 6 different dancing movements. The resulting computed motions were applied to patient-specific hip joint 3-dimensional models based on magnetic resonance images. While visualizing the dancer's hip in motion, the authors detected impingements using computer-assisted techniques. The range of motion and congruence of the hip joint were also quantified in those 6 recorded dancing movements. The frequency of impingement and subluxation varied with the type of movement. Four dancing movements (développé à la seconde, grand écart facial, grand écart latéral, and grand plié) seem to induce significant stress in the hip joint, according to the observed high frequency of impingement and amount of subluxation. The femoroacetabular translations were high (range, 0.93 to 6.35 mm). For almost all movements, the computed zones of impingement were mainly located in the superior or posterosuperior quadrant of the acetabulum, which was relevant with respect to radiologically diagnosed damaged zones in the labrum. All dancers' hips were morphologically normal. Impingements and subluxations are frequently observed in typical ballet movements, causing cartilage hypercompression. These movements should be limited in frequency. The present study indicates that some dancing movements could damage the hip joint, which could lead to early osteoarthritis.

Acoustic emissions (AE) monitoring of large-scale composite bridge components

NASA Astrophysics Data System (ADS)

Velazquez, E.; Klein, D. J.; Robinson, M. J.; Kosmatka, J. B.

2008-03-01

Acoustic Emissions (AE) has been successfully used with composite structures to both locate and give a measure of damage accumulation. The current experimental study uses AE to monitor large-scale composite modular bridge components. The components consist of a carbon/epoxy beam structure as well as a composite to metallic bonded/bolted joint. The bonded joints consist of double lap aluminum splice plates bonded and bolted to carbon/epoxy laminates representing the tension rail of a beam. The AE system is used to monitor the bridge component during failure loading to assess the failure progression and using time of arrival to give insight into the origins of the failures. Also, a feature in the AE data called Cumulative Acoustic Emission counts (CAE) is used to give an estimate of the severity and rate of damage accumulation. For the bolted/bonded joints, the AE data is used to interpret the source and location of damage that induced failure in the joint. These results are used to investigate the use of bolts in conjunction with the bonded joint. A description of each of the components (beam and joint) is given with AE results. A summary of lessons learned for AE testing of large composite structures as well as insight into failure progression and location is presented.

Effect of Intermetallic on Electromigration and Atomic Diffusion in Cu/SnAg3.0Cu0.5/Cu Joints: Experimental and First-Principles Study

NASA Astrophysics Data System (ADS)

Zhou, Wei; Liu, Lijuan; Li, Baoling; Wu, Ping

2009-06-01

Electromigration phenomena in a one-dimensional Cu/SnAg3.0Cu0.5/Cu joint were investigated with current stressing. The special effect of intermetallic compound (IMC) layers on the formation of serious electromigration damage induced by nonuniform current density distribution was discussed based on experimental results. Meanwhile, hillocks were observed both at the anode and near the cathode of the joint, and they were described as the result of diffusion of atoms and compressive stress released along grain boundaries to the relatively free surface. Moreover, the diffusion behavior of Cu at the cathode was analyzed with the electromigration equation, and the stability of Ag atoms in the solder during electromigration was evaluated with a first-principles method.

Buckling of a Longitudinally Jointed Curved Composite Panel Arc Segment for Next Generation of Composite Heavy Lift Launch Vehicles: Verification Testing Analysis

NASA Technical Reports Server (NTRS)

Farrokh, Babak; Segal, Kenneth N.; Akkerman, Michael; Glenn, Ronald L.; Rodini, Benjamin T.; Fan, Wei-Ming; Kellas, Sortiris; Pineda, Evan J.

2014-01-01

In this work, an all-bonded out-of-autoclave (OoA) curved longitudinal composite joint concept, intended for use in the next generation of composite heavy lift launch vehicles, was evaluated and verified through finite element (FE) analysis, fabrication, testing, and post-test inspection. The joint was used to connect two curved, segmented, honeycomb sandwich panels representative of a Space Launch System (SLS) fairing design. The overall size of the resultant panel was 1.37 m by 0.74 m (54 in by 29 in), of which the joint comprised a 10.2 cm (4 in) wide longitudinal strip at the center. NASTRAN and ABAQUS were used to perform linear and non-linear analyses of the buckling and strength performance of the jointed panel. Geometric non-uniformities (i.e., surface contour imperfections) were measured and incorporated into the FE model and analysis. In addition, a sensitivity study of the specimens end condition showed that bonding face-sheet doublers to the panel's end, coupled with some stress relief features at corner-edges, can significantly reduce the stress concentrations near the load application points. Ultimately, the jointed panel was subjected to a compressive load. Load application was interrupted at the onset of buckling (at 356 kN 80 kips). A post-test non-destructive evaluation (NDE) showed that, as designed, buckling occurred without introducing any damage into the panel or the joint. The jointed panel was further capable of tolerating an impact damage to the same buckling load with no evidence of damage propagation. The OoA cured all-composite joint shows promise as a low mass factory joint for segmented barrels.

In Vivo Dual Fluorescence Imaging to Detect Joint Destruction.

PubMed

Cho, Hongsik; Bhatti, Fazal-Ur-Rehman; Lee, Sangmin; Brand, David D; Yi, Ae-Kyung; Hasty, Karen A

2016-10-01

Diagnosis of cartilage damage in early stages of arthritis is vital to impede the progression of disease. In this regard, considerable progress has been made in near-infrared fluorescence (NIRF) optical imaging technique. Arthritis can develop due to various mechanisms but one of the main contributors is the production of matrix metalloproteinases (MMPs), enzymes that can degrade components of the extracellular matrix. Especially, MMP-1 and MMP-13 have main roles in rheumatoid arthritis and osteoarthritis because they enhance collagen degradation in the process of arthritis. We present here a novel NIRF imaging strategy that can be used to determine the activity of MMPs and cartilage damage simultaneously by detection of exposed type II collagen in cartilage tissue. In this study, retro-orbital injection of mixed fluorescent dyes, MMPSense 750 FAST (MMP750) dye and Alexa Fluor 680 conjugated monoclonal mouse antibody immune-reactive to type II collagen, was administered in the arthritic mice. Both dyes were detected with different intensity according to degree of joint destruction in the animal. Thus, our dual fluorescence imaging method can be used to detect cartilage damage as well as MMP activity simultaneously in early stage arthritis. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Characterization of the surface and interfacial properties of the lamina splendens

NASA Astrophysics Data System (ADS)

Rexwinkle, Joe T.; Hunt, Heather K.; Pfeiffer, Ferris M.

2017-06-01

Joint disease affects approximately 52.5 million patients in the United States alone, costing 80.8 billion USD in direct healthcare costs. The development of treatment programs for joint disease and trauma requires accurate assessment of articular cartilage degradation. The articular cartilage is the interfacial tissue between articulating surfaces, such as bones, and acts as low-friction interfaces. Damage to the lamina splendens, which is the articular cartilage's topmost layer, is an early indicator of joint degradation caused by injury or disease. By gaining comprehensive knowledge on the lamina splendens, particularly its structure and interfacial properties, researchers could enhance the accuracy of human and animal biomechanical models, as well as develop appropriate biomimetic materials for replacing damaged articular cartilage, thereby leading to rational treatment programs for joint disease and injury. Previous studies that utilize light, electron, and force microscopy techniques have found that the lamina splendens is composed of collagen fibers oriented parallel to the cartilage surface and encased in a proteoglycan matrix. Such orientation maximizes wear resistance and proteoglycan retention while promoting the passage of nutrients and synovial fluid. Although the structure of the lamina splendens has been explored in the literature, the low-friction interface of this tissue remains only partially characterized. Various functional models are currently available for the interface, such as pure boundary lubrication, thin films exuded under pressure, and sheets of trapped proteins. Recent studies suggest that each of these lubrication models has certain advantages over one another. Further research is needed to fully model the interface of this tissue. In this review, we summarize the methods for characterizing the lamina splendens and the results of each method. This paper aims to serve as a resource for existing studies to date and a roadmap of the investigations needed to gain further insight into the lamina splendens and the progression of joint disease.

Monosodium urate crystal deposition associated with the progress of radiographic grade at the sacroiliac joint in axial SpA: a dual-energy CT study.

PubMed

Zhu, Junqing; Li, Aiwu; Jia, Ertao; Zhou, Yi; Xu, Juan; Chen, Shixian; Huang, Yinger; Xiao, Xiang; Li, Juan

2017-05-02

Previous studies have revealed that ankylosing spondylitis (AS), as the progenitor of axial spondyloarthritis (AxSpA), has been characterized by the insidiously progressive nature of sacroiliitis and spondylitis. Dual-energy computed tomography (DECT) has recently been used to analyse the deposition of monosodium urate (MSU) crystals with higher sensitivity and specificity. However, it remains unclear whether the existence of the MSU crystal deposition detected by DECT at the sacroiliac joint in patients with AxSpA also is associated with the existing structural damage. Here, we performed this study to show the DECT MSU crystal deposits in AxSpA patients without coexisting gout and to ascertain the relationship between the MSU crystal deposition and the structural joint damage of sacroiliac joints. One hundred and eighty-six AxSpA patients without coexisting gout were recruited. The plain radiographs of the sacroiliac joint were obtained, along with the DECT scans at the pelvis and the clinical variables. All statistics based on the left or right sacroiliac joint damage grading (0-4) were calculated independently. Bivariate analysis and ordinal logistic regression was performed between the clinical features and radiographic grades at the sacroiliac joint. At the pelvis, large quantities of MSU crystal deposition were found in patients with AxSpA. The average MSU crystal volume at the left sacroiliac joint, the right sacroiliac joint, and the pelvis were 0.902 ± 1.345, 1.074 ± 1.878, and 5.272 ± 9.044 cm 3 , values which were correlated with serum uric acid concentrations (r = 0.727, 0.740, 0.896; p < 0.001). In bivariate analysis, wide clinical variables were associated with the changes in sacroiliac joint damage. Further, the AxSpA duration, BASFI score, and the volume of MSU crystal at both sides of sacroiliac joint were associated with the progress of radiographic grade at the sacroiliac joints in the ordinal logistic models (left AOR = 1.180, 3.800, 1.920; right AOR = 1.190, 3.034, 1.418; p < 0.01). Large quantities of MSU crystal deposition detected by DECT were found at the pelvis in AxSpA patients without coexisting gout. In addition to AxSpA duration and BASFI score, the MSU crystal deposition at the sacroiliac joint is associated with the progress of radiographic grade at sacroiliac joints in those patients.

Hyperspectral imaging for detection of arthritis: feasibility and prospects

NASA Astrophysics Data System (ADS)

Milanic, Matija; Paluchowski, Lukasz A.; Randeberg, Lise L.

2015-09-01

Rheumatoid arthritis (RA) is a disease that frequently leads to joint destruction. It has a high incidence rate worldwide, and the disease significantly reduces patients' quality of life. Detecting and treating inflammatory arthritis before structural damage to the joint has occurred is known to be essential for preventing patient disability and pain. Existing diagnostic technologies are expensive, time consuming, and require trained personnel to collect and interpret data. Optical techniques might be a fast, noninvasive alternative. Hyperspectral imaging (HSI) is a noncontact optical technique which provides both spectral and spatial information in one measurement. In this study, the feasibility of HSI in arthritis diagnostics was explored by numerical simulations and optimal imaging parameters were identified. Hyperspectral reflectance and transmission images of RA and normal human joint models were simulated using the Monte Carlo method. The spectral range was 600 to 1100 nm. Characteristic spatial patterns for RA joints and two spectral windows with transmission were identified. The study demonstrated that transmittance images of human joints could be used as one parameter for discrimination between arthritic and unaffected joints. The presented work shows that HSI is a promising imaging modality for the diagnostics and follow-up monitoring of arthritis in small joints.

Failure analysis of single-bolted joint for lightweight composite laminates and metal plate

NASA Astrophysics Data System (ADS)

Li, Linjie; Qu, Junli; Liu, Xiangdong

2018-01-01

A three-dimensional progressive damage model was developed in ANSYS to predict the damage accumulation of single bolted joint in composite laminates under in-plane tensile loading. First, we describe the formulation and algorithm of this model. Second, we calculate the failure loads of the joint in fibre reinforced epoxy laminated composite plates and compare it with the experiment results, which validates that our model can appropriately simulate the ultimate tensile strength of the joints and the whole process of failure of structure. Finally, this model is applied to study the failure process of the light-weight composite material (USN125). The study also has a great potential to provide a strong basis for bolted joints design in composite Laminates as well as a simple tool for comparing different laminate geometries and bolt arrangements.

Durability predictions of adhesively bonded composite structures using accelerated characterization methods

NASA Technical Reports Server (NTRS)

Brinson, H. F.

1985-01-01

The utilization of adhesive bonding for composite structures is briefly assessed. The need for a method to determine damage initiation and propagation for such joints is outlined. Methods currently in use to analyze both adhesive joints and fiber reinforced plastics is mentioned and it is indicated that all methods require the input of the mechanical properties of the polymeric adhesive and composite matrix material. The mechanical properties of polymers are indicated to be viscoelastic and sensitive to environmental effects. A method to analytically characterize environmentally dependent linear and nonlinear viscoelastic properties is given. It is indicated that the methodology can be used to extrapolate short term data to long term design lifetimes. That is, the method can be used for long term durability predictions. Experimental results for near adhesive resins, polymers used as composite matrices and unidirectional composite laminates is given. The data is fitted well with the analytical durability methodology. Finally, suggestions are outlined for the development of an analytical methodology for the durability predictions of adhesively bonded composite structures.

The role of IL‐23 receptor signaling in inflammation‐mediated erosive autoimmune arthritis and bone remodeling

PubMed Central

Razawy, Wida; van Driel, Marjolein

2018-01-01

Abstract The IL‐23/Th17 axis has been implicated in the development of autoimmune diseases, such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA). RA and PsA are heterogeneous diseases with substantial burden on patients. Increasing evidence suggests that the IL‐23 signaling pathway may be involved in the development of autoimmunity and erosive joint damage. IL‐23 can act either directly or indirectly on bone forming osteoblasts as well as on bone resorbing osteoclasts. As IL‐23 regulates the activity of cells of the bone, it is conceivable that in addition to inflammation‐mediated joint erosion, IL‐23 may play a role in physiological bone remodeling. In this review, we focus on the role of IL‐23 in autoimmune arthritis in patients and murine models, and provide an overview of IL‐23 producing and responding cells in autoimmune arthritic joints. In addition, we discuss the role of IL‐23 on bone forming osteoblasts and bone resorbing osteoclasts regarding inflammation‐mediated joint damage and bone remodeling. At last, we briefly discuss the clinical implications of targeting this pathway for joint damage and systemic bone loss in autoimmune arthritis. PMID:29148561

A comparative MRI study of cartilage damage in gout versus rheumatoid arthritis.

PubMed

Popovich, Ivor; Lee, Arier C L; Doyle, Anthony; McHaffie, Alexandra; Clarke, Andrew; Reeves, Quentin; Dalbeth, Nicola; McQueen, Fiona M

2015-08-01

Magnetic resonance imaging (MRI) is useful for detecting joint inflammation and damage in the inflammatory arthropathies. This study aimed to investigate MRI cartilage damage and its associations with joint inflammation in patients with gout compared with a group with rheumatoid arthritis (RA). Forty patients with gout and 38 with seropositive RA underwent 3T-MRI of the wrist with assessment of cartilage damage at six carpal sites, using established scoring systems. Synovitis and bone oedema (BME) were graded according to Rheumatoid Arthritis MRI Scoring System criteria. Cartilage damage was compared between the groups adjusting for synovitis and disease duration using logistic regression analysis. Compared with RA, there were fewer sites of cartilage damage and lower total damage scores in the gout group (P = 0.02 and 0.003), adjusting for their longer disease duration and lesser degree of synovitis. Cartilage damage was strongly associated with synovitis in both conditions (R = 0.59, P < 0.0001 and R = 0.52, P = 0.0045 respectively) and highly correlated with BME in RA (R = 0.69, P < 0.0001) but not in gout (R = 0.095, P = 0.56). Cartilage damage is less severe in gout than in RA, with fewer sites affected and lower overall scores. It is associated with synovitis in both diseases, likely indicating an effect of pro-inflammatory cytokine production on cartilage integrity. However, the strong association between cartilage damage and BME observed in RA was not identified in gout. This emphasizes differences in the underlying pathophysiology of joint damage in these two conditions. © 2015 The Royal Australian and New Zealand College of Radiologists.

Toward patient-specific articular contact mechanics

PubMed Central

Ateshian, Gerard A.; Henak, Corinne R.; Weiss, Jeffrey A.

2015-01-01

The mechanics of contacting cartilage layers is fundamentally important to understanding the development, homeostasis and pathology of diarthrodial joints. Because of the highly nonlinear nature of both the materials and the contact problem itself, numerical methods such as the finite element method are typically incorporated to obtain solutions. Over the course of five decades, we have moved from an initial qualitative understanding of articular cartilage material behavior to the ability to perform complex, three-dimensional contact analysis, including multiphasic material representations. This history includes the development of analytical and computational contact analysis methods that now provide the ability to perform highly nonlinear analyses. Numerical implementations of contact analysis based on the finite element method are rapidly advancing and will soon enable patient-specific analysis of joint contact mechanics using models based on medical image data. In addition to contact stress on the articular surfaces, these techniques can predict variations in strain and strain through the cartilage layers, providing the basis to predict damage and failure. This opens up exciting areas for future research and application to patient-specific diagnosis and treatment planning applied to a variety of pathologies that affect joint function and cartilage homeostasis. PMID:25698236

Influence of interface ply orientation on fatigue damage of adhesively bonded composite joints

NASA Technical Reports Server (NTRS)

Johnson, W. S.; Mall, S.

1985-01-01

An experimental study of cracked-lap-shear specimens was conducted to determine the influence of adherend stacking sequence on debond initiation and damage growth in a composite-to-composite bonded joint. Specimens consisted of quasi-isotropic graphite/epoxy adherends bonded together with either FM-300 or EC 3445 adhesives. The stacking sequence of the adherends was varied such that 0 deg, 45 deg, or 90 deg plies were present at the adherend-adhesive interfaces. Fatigue damage initiated in the adhesive layer in those specimens with 0 deg nd 45 deg interface plies. Damage initiated in the form of ply cracking in the strap adherend for the specimens with 90 deg interface plies. The fatigue-damage growth was in the form of delamination within the composite adherends for specimens with the 90 deg and 45 deg plies next to the adhesive, while debonding in the adhesive resulted for the specimens with 0 deg plies next to the adhesive. Those joints with the 0 deg and 45 deg plies next to either adhesive has essentially the same fatigue-damage-initiation stress levels. These stress levels were 13 and 71 percent higher, respectively, than those for specimens with 90 deg plies next to the EC 3445 and FM-300 adhesives.

A Biomimetic Structural Health Monitoring Approach Using Carbon Nanotubes

NASA Astrophysics Data System (ADS)

Liu, Yingtao; Rajadas, Abhishek; Chattopadhyay, Aditi

2012-07-01

A self-sensing nanocomposite material has been developed to track the presence of damage in complex composite structures. Multiwalled carbon nanotubes are integrated with polymer matrix to develop a novel bonding material with sensing capabilities. The changes of the piezoresistance in the presence of damage are used to monitor the condition of bonded joints, where the usual bonding material is replaced by the self-sensing nanocomposite. The feasibility of this concept is investigated through experiments conducted on single-lap joints subject to monotonic tensile loading conditions. The results show that the self-sensing nanocomposite is sensitive to crack propagation within the matrix material. An acoustic emission-based sensing technique has been used to validate these results and shows good correlation with damage growth. A digital image correlation system is used to measure the shear strain field in the joint area.

Deficiency of Hyaluronan Synthase 1 (Has1) Results in Chronic Joint Inflammation and Widespread Intra-Articular Fibrosis in a Murine Model of Knee Joint Cartilage Damage

PubMed Central

Chan, Deva D.; Xiao, Wenfeng; Li, Jun; de la Motte, Carol A.; Sandy, John D.; Plaas, Anna

2015-01-01

Objective Articular cartilage defects commonly result from traumatic injury and predispose to degenerative joint diseases. To test the hypothesis that aberrant healing responses and chronic inflammation lead to osteoarthritis, we examined spatiotemporal changes in joint tissues after cartilage injury in murine knees. Since intra-articular injection of hyaluronan (HA) can attenuate injury-induced osteoarthritis in wild-type (WT) mice, we investigated a role for HA in the response to cartilage injury in mice lacking HA synthase 1 (Has1−/−). Design Femoral groove cartilage of WT and Has1−/− mice was debrided to generate a non-bleeding wound. Macroscopic imaging, histology, and gene expression were used to evaluate naïve, sham-operated, and injured joints. Results Acute responses (1–2 weeks) in injured joints from WT mice included synovial hyperplasia with HA deposition and joint-wide increases in expression of genes associated with inflammation, fibrosis, and extracellular matrix (ECM) production. By 4 weeks, some resurfacing of damaged cartilage occurred, and early cell responses were normalized. Cartilage damage in Has1−/− mice also induced early responses; however, at 4 weeks, inflammation and fibrosis genes remained elevated with widespread cartilage degeneration and fibrotic scarring in the synovium and joint capsule. Conclusions We conclude that the ineffective repair of injured cartilage in Has1−/− joints can be at least partly explained by the markedly enhanced expression of particular genes in pathways linked to ECM turnover, IL-17/IL-6 cytokine signaling, and apoptosis. Notably, Has1 ablation does not alter gross HA content in the ECM, suggesting that HAS1 has a unique function in the metabolism of inflammatory HA matrices. PMID:26521733

Experimental Studies on the Mechanical Behaviour of Rock Joints with Various Openings

NASA Astrophysics Data System (ADS)

Li, Y.; Oh, J.; Mitra, R.; Hebblewhite, B.

2016-03-01

The mechanical behaviour of rough joints is markedly affected by the degree of joint opening. A systematic experimental study was conducted to investigate the effect of the initial opening on both normal and shear deformations of rock joints. Two types of joints with triangular asperities were produced in the laboratory and subjected to compression tests and direct shear tests with different initial opening values. The results showed that opened rock joints allow much greater normal closure and result in much lower normal stiffness. A semi-logarithmic law incorporating the degree of interlocking is proposed to describe the normal deformation of opened rock joints. The proposed equation agrees well with the experimental results. Additionally, the results of direct shear tests demonstrated that shear strength and dilation are reduced because of reduced involvement of and increased damage to asperities in the process of shearing. The results indicate that constitutive models of rock joints that consider the true asperity contact area can be used to predict shear resistance along opened rock joints. Because rock masses are loosened and rock joints become open after excavation, the model suggested in this study can be incorporated into numerical procedures such as finite-element or discrete-element methods. Use of the model could then increase the accuracy and reliability of stability predictions for rock masses under excavation.

Damage detection of rotating wind turbine blades using local flexibility method and long-gauge fiber Bragg grating sensors

NASA Astrophysics Data System (ADS)

Hsu, Ting-Yu; Shiao, Shen-Yuan; Liao, Wen-I.

2018-01-01

Wind turbines are a cost-effective alternative energy source; however, their blades are susceptible to damage. Therefore, damage detection of wind turbine blades is of great importance for condition monitoring of wind turbines. Many vibration-based structural damage detection techniques have been proposed in the last two decades. The local flexibility method, which can determine local stiffness variations of beam-like structures by using measured modal parameters, is one of the most promising vibration-based approaches. The local flexibility method does not require a finite element model of the structure. A few structural modal parameters identified from the ambient vibration signals both before and after damage are required for this method. In this study, we propose a damage detection approach for rotating wind turbine blades using the local flexibility method based on the dynamic macro-strain signals measured by long-gauge fiber Bragg grating (FBG)-based sensors. A small wind turbine structure was constructed and excited using a shaking table to generate vibration signals. The structure was designed to have natural frequencies as close as possible to those of a typical 1.5 MW wind turbine in real scale. The optical fiber signal of the rotating blades was transmitted to the data acquisition system through a rotary joint fixed inside the hollow shaft of the wind turbine. Reversible damage was simulated by aluminum plates attached to some sections of the wind turbine blades. The damaged locations of the rotating blades were successfully detected using the proposed approach, with the extent of damage somewhat over-estimated. Nevertheless, although the specimen of wind turbine blades cannot represent a real one, the results still manifest that FBG-based macro-strain measurement has potential to be employed to obtain the modal parameters of the rotating wind turbines and then locations of wind turbine segments with a change of rigidity can be estimated effectively by utilizing these identified parameters.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.

The international fusion community has designed a miniature torsion specimen for neutron irradiation studies of joined SiC and SiC/SiC composite materials. Miniature torsion joints based on this specimen design were fabricated using displacement reactions between Si and TiC to produce Ti3SiC2 + SiC joints with CVD-SiC and tested in torsion-shear prior to and after neutron irradiation. However, many of these miniature torsion specimens fail out-of-plane within the CVD-SiC specimen body, which makes it problematic to assign a shear strength value to the joints and makes it difficult to compare unirradiated and irradiated joint strengths to determine the effects of themore » irradiation. Finite element elastic damage and elastic-plastic damage models of miniature torsion joints are developed that indicate shear fracture is likely to occur within the body of the joined sample and cause out-of-plane failures for miniature torsion specimens when a certain modulus and strength ratio between the joint material and the joined material exists. The model results are compared and discussed with regard to unirradiated and irradiated joint test data for a variety of joint materials. The unirradiated data includes Ti3SiC2 + SiC/CVD-SiC joints with tailored joint moduli, and includes steel/epoxy and CVD-SiC/epoxy joints. The implications for joint data based on this sample design are discussed.« less

Detection and assessment of flaws in friction stir welded joints using ultrasonic guided waves: experimental and finite element analysis

NASA Astrophysics Data System (ADS)

Fakih, Mohammad Ali; Mustapha, Samir; Tarraf, Jaafar; Ayoub, Georges; Hamade, Ramsey

2018-02-01

Ultrasonic guided waves (GWs), e.g. Lamb waves, have been proven effective in the detection of defects such as corrosion, cracking, delamination, and debonding in both composite and metallic structures. They are a significant tool employed in structural health monitoring. In this study, the ability of ultrasonic GWs to assess the quality of friction stir welding (FSW) was investigated. Four friction stir welded AZ31B magnesium plates processed with different welding parameters and a non-welded plate were used. The fundamental symmetric (S0) Lamb wave mode was excited using piezoelectric wafers (PZTs). Further, the S0 mode was separated using the "Improved complete ensemble empirical mode decomposition with adaptive noise (Improved CEEMDAN)" technique. A damage index (DI) was defined based on the variation in the amplitude of the captured wave signals in order to detect the presence and asses the severity of damage resulting from the welding process. As well, computed tomography (CT) scanning was used as a non-destructive testing (NDT) technique to assess the actual weld quality and validate predictions based on the GW approach. The findings were further confirmed using finite element analysis (FEA). To model the actual damage profile in the welds, "Mimics" software was used for the 3D reconstruction of the CT scans. The built 3D models were later used for evaluation of damage volume and for FEA. The damage volumes were correlated to the damage indices computed from both experimental and numerical data. The proposed approach showed high sensitivity of the S0 mode to internal flaws within the friction stir welded joints. This methodology has great potential as a future classification method of FSW quality.

Meniscus Induced Cartilaginous Damage and Non-linear Gross Anatomical Progression of Early-stage Osteoarthritis in a Canine Model

PubMed Central

Kahn, David; Mittelstaedt, Daniel; Matyas, John; Qu, Xiangui; Lee, Ji Hyun; Badar, Farid; Les, Clifford; Zhuang, Zhiguo; Xia, Yang

2016-01-01

Background: The predictable outcome of the anterior cruciate ligament transection (ACLT) canine model, and the similarity to naturally occurring osteoarthritis (OA) in humans, provide a translatable method for studying OA. Still, evidence of direct meniscus-induced cartilaginous damage has not been identified, and gross-anatomical blinded scoring of early-stage OA has not been performed. Objective: A gross anatomical observation and statistical analysis of OA progression to determine meniscus induced cartilaginous damage, to measure the macroscopic progression of OA, and to address matters involving arthroscopic and surgical procedures of the knee. Method: Unblinded assessment and blinded scoring of meniscal, tibial, femoral, and patellar damage were performed for control and at four time points following unilateral ACLT: 3-week (N=4), 8-week (N=4), 12-week (N=5), and 25-week (N=4). Mixed-model statistics illustrates damage (score) progression; Wilcoxon rank-sum tests compared time-point scores; and Wilcoxon signed-rank tests compared ACLT and contralateral scores, and meniscus and tibia scores. Result: Damage was manifest first on the posterior aspect of the medial meniscus and subsequently on the tibia and femur, implying meniscal damage can precede, coincide with, and aggravate cartilage damage. Damage extent varied chronologically and was dependent upon the joint component. Meniscal damage was evident at 3 weeks and progressed through 25-weeks. Meniscal loose bodies corresponded to tibial cartilage damage location and extent through 12 weeks, followed by cartilage repair activity after complete meniscal degeneration. Conclusion: This study provides additional information for understanding OA progression, identifying OA biomarkers, and arthroscopic and meniscectomy procedures. PMID:28144379

A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

NASA Technical Reports Server (NTRS)

Harris, Charles E.; Piascik, Robert S.; Newman, James C., Jr.

1999-01-01

An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

NASA Technical Reports Server (NTRS)

Harris, C. E.; Piascik, R. S.; Newman, J. C., Jr.

2000-01-01

An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

Experimental studies of diffusion welding of YBCO to copper using solder layers

NASA Astrophysics Data System (ADS)

Xie, Y.; Ouyang, Z.; Shi, L.; Kuang, Z.; Meng, M.

2017-02-01

The welding technology is of great importance in YBCO application. To make better joints, the diffusion welding of YBCO tape to copper has been carried out in a vacuum environment. In consideration of high welding temperature (above 200°C) could do damage to the material performance, a new kind of diffusion welding method with temperature below 200 °C has been developed recently. A new welding appliance which can offer pressure over 35Kg/mm2 and controlled temperature has been designed and built; several YBCO coated conductors joints soldered with different melting points of tins has been tested. The results showed that the diffusion can perfectly connect YBCO to copper as well as stainless steel and resistance of the joint was low, and the YBCO tape could bear 217°C for at least 15mins.

Histomorphology and innate immunity during the progression of osteoarthritis: Does synovitis affect cartilage degradation?

PubMed

Wang, Huan; Wang, Qingguo; Yang, Meijuan; Yang, Lili; Wang, Weili; Ding, Haobin; Zhang, Dong; Xu, Jing; Tang, Xuezhang; Ding, Haitao; Wang, Qingfu

2018-02-01

Osteoarthritis (OA) is a common chronic degenerative disease that affects all joints. At present, the pathological processes and mechanisms of OA are still unclear. Innate immunity, a key player in damage to the structure of the joint and the mechanism by which the host attempts to repair OA, affects all pathological stages of the disease. In the present study, our aim was to assess changes in innate immunity during the pathological processes of OA in articular cartilage (AC) and the synovial membrane (SM), which are the major structures in joints, and to systematically examine the histological changes in AC and SM in mild, moderate and severe cases of OA, in order to further speculate about the manner in which the interactions of AC and SM are facilitated by innate immunity. Histological methods (including HE and Safranin O-fast green staining), immunofluorescent double staining, TUNEL stain, and Western blots were used to assess the morphological changes within AC and SM tissues in healthy and mild, moderate, or severe OA rats. Our results showed that the damage to AC and SM within the joints progressively worsened in different degrees during the course of the disease, and that the innate immune system was closely involved in the AC and SM during each stage of OA. These findings also confirmed that SM may affect the pathological changes in AC through the innate immune system, and therefore affect the progress of OA. © 2017 Wiley Periodicals, Inc.

Clustered multistate models with observation level random effects, mover-stayer effects and dynamic covariates: modelling transition intensities and sojourn times in a study of psoriatic arthritis.

PubMed

Yiu, Sean; Farewell, Vernon T; Tom, Brian D M

2018-02-01

In psoriatic arthritis, it is important to understand the joint activity (represented by swelling and pain) and damage processes because both are related to severe physical disability. The paper aims to provide a comprehensive investigation into both processes occurring over time, in particular their relationship, by specifying a joint multistate model at the individual hand joint level, which also accounts for many of their important features. As there are multiple hand joints, such an analysis will be based on the use of clustered multistate models. Here we consider an observation level random-effects structure with dynamic covariates and allow for the possibility that a subpopulation of patients is at minimal risk of damage. Such an analysis is found to provide further understanding of the activity-damage relationship beyond that provided by previous analyses. Consideration is also given to the modelling of mean sojourn times and jump probabilities. In particular, a novel model parameterization which allows easily interpretable covariate effects to act on these quantities is proposed.

Exploring cartilage damage in gout using 3-T MRI: distribution and associations with joint inflammation and tophus deposition.

PubMed

Popovich, I; Dalbeth, N; Doyle, A; Reeves, Q; McQueen, F M

2014-07-01

Few imaging studies have investigated cartilage in gout. Magnetic resonance imaging (MRI) can image cartilage damage and also reveals other features of gouty arthropathy. The objective was to develop and validate a system for quantifying cartilage damage in gout. 3-T MRI scans of the wrist were obtained in 40 gout patients. MRI cartilage damage was quantified using an adaptation of the radiographic Sharp van der Heijde score. Two readers scored cartilage loss at 7 wrist joints: 0 (normal), 1 (partial narrowing), 2 (complete narrowing) and concomitant osteoarthritis was recorded. Bone erosion, bone oedema and synovitis were scored (RAMRIS) and tophi were assessed. Correlations between radiographic and MRI cartilage scores were investigated, as was the reliability of the MRI cartilage score and its associations. The GOut MRI Cartilage Score (GOMRICS) was highly correlated with the total Sharp van der Heijde (SvdH) score and the joint space narrowing component (R = 0.8 and 0.71 respectively, p < 0.001). Reliability was high (intraobserver, interobserver ICCs = 0.87 [0.57-0.97], 0.64 [0.41-0.79] respectively), and improved on unenhanced scans; interobserver ICC = 0.82 [0.49-0.95]. Cartilage damage was predominantly focal (82% of lesions) and identified in 40 out of 280 (14%) of joints. Cartilage scores correlated with bone erosion (R = 0.57), tophus size (R = 0.52), and synovitis (R = 0.55), but not bone oedema scores. Magnetic resonance imaging can be used to investigate cartilage in gout. Cartilage damage was relatively uncommon, focal, and associated with bone erosions, tophi and synovitis, but not bone oedema. This emphasises the unique pathophysiology of gout.

LOW ACTIVATION JOINING OF SIC/SIC COMPOSITES FOR FUSION APPLICATIONS: MODELING DUAL-PHASE MICROSTRUCTURES AND DISSIMILAR MATERIAL JOINTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.

2016-03-31

Finite element continuum damage models (FE-CDM) have been developed to simulate and model dual-phase joints and cracked joints for improved analysis of SiC materials in nuclear environments. This report extends the analysis from the last reporting cycle by including results from dual-phase models and from cracked joint models.

Talar Fractures in Children: A Possible Injury After Go-Karting Accidents.

PubMed

Kamphuis, Saskia J M; Meijs, Claartje M E M; Kleinveld, Sanne; Diekerhof, Carel H; van der Heijden, Frank H W M

2015-01-01

Go-karting is an increasingly popular high-energy sport enjoyed by both children and adults. Because of the speeds involved, accidents involving go-karts can lead to serious injury. We describe 6 talar fractures in 4 patients that resulted from go-karting accidents. Talar fractures can cause severe damage to the tibiotalar joint, talocalcaneal or subtalar joint, and the talonavicular joint. This damage can, in turn, lead to complications such as avascular necrosis, arthritis, nonunion, delayed union, and neuropraxia, which have the potential to cause long-term disability in a child. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

A Fiber Optic Doppler Sensor and Its Application in Debonding Detection for Composite Structures

PubMed Central

Li, Fucai; Murayama, Hideaki; Kageyama, Kazuro; Meng, Guang; Ohsawa, Isamu; Shirai, Takehiro

2010-01-01

Debonding is one of the most important damage forms in fiber-reinforced composite structures. This work was devoted to the debonding damage detection of lap splice joints in carbon fiber reinforced plastic (CFRP) structures, which is based on guided ultrasonic wave signals captured by using fiber optic Doppler (FOD) sensor with spiral shape. Interferometers based on two types of laser sources, namely the He-Ne laser and the infrared semiconductor laser, are proposed and compared in this study for the purpose of measuring Doppler frequency shift of the FOD sensor. Locations of the FOD sensors are optimized based on mechanical characteristics of lap splice joint. The FOD sensors are subsequently used to detect the guided ultrasonic waves propagating in the CFRP structures. By taking advantage of signal processing approaches, features of the guided wave signals can be revealed. The results demonstrate that debonding in the lap splice joint results in arrival time delay of the first package in the guided wave signals, which can be the characteristic for debonding damage inspection and damage extent estimation. PMID:22219698

A fiber optic Doppler sensor and its application in debonding detection for composite structures.

PubMed

Li, Fucai; Murayama, Hideaki; Kageyama, Kazuro; Meng, Guang; Ohsawa, Isamu; Shirai, Takehiro

2010-01-01

Debonding is one of the most important damage forms in fiber-reinforced composite structures. This work was devoted to the debonding damage detection of lap splice joints in carbon fiber reinforced plastic (CFRP) structures, which is based on guided ultrasonic wave signals captured by using fiber optic Doppler (FOD) sensor with spiral shape. Interferometers based on two types of laser sources, namely the He-Ne laser and the infrared semiconductor laser, are proposed and compared in this study for the purpose of measuring Doppler frequency shift of the FOD sensor. Locations of the FOD sensors are optimized based on mechanical characteristics of lap splice joint. The FOD sensors are subsequently used to detect the guided ultrasonic waves propagating in the CFRP structures. By taking advantage of signal processing approaches, features of the guided wave signals can be revealed. The results demonstrate that debonding in the lap splice joint results in arrival time delay of the first package in the guided wave signals, which can be the characteristic for debonding damage inspection and damage extent estimation.

The numerical high cycle fatigue damage model of fillet weld joint under weld-induced residual stresses

NASA Astrophysics Data System (ADS)

Nguyen Van Do, Vuong

2018-04-01

In this study, a development of nonlinear continuum damage mechanics (CDM) model for multiaxial high cycle fatigue is proposed in which the cyclic plasticity constitutive model has been incorporated in the finite element (FE) framework. T-joint FE simulation of fillet welding is implemented to characterize sequentially coupled three-dimensional (3-D) of thermo-mechanical FE formulation and simulate the welding residual stresses. The high cycle fatigue damage model is then taken account into the fillet weld joints under the various cyclic fatigue load types to calculate the fatigue life considering the residual stresses. The fatigue crack initiation and the propagation in the present model estimated for the total fatigue is compared with the experimental results. The FE results illustrated that the proposed high cycle fatigue damage model in this study could become a powerful tool to effectively predict the fatigue life of the welds. Parametric studies in this work are also demonstrated that the welding residual stresses cannot be ignored in the computation of the fatigue life of welded structures.

Experimental Investigation on the Fatigue Mechanical Properties of Intermittently Jointed Rock Models Under Cyclic Uniaxial Compression with Different Loading Parameters

NASA Astrophysics Data System (ADS)

Liu, Yi; Dai, Feng; Dong, Lu; Xu, Nuwen; Feng, Peng

2018-01-01

Intermittently jointed rocks, widely existing in many mining and civil engineering structures, are quite susceptible to cyclic loading. Understanding the fatigue mechanism of jointed rocks is vital to the rational design and the long-term stability analysis of rock structures. In this study, the fatigue mechanical properties of synthetic jointed rock models under different cyclic conditions are systematically investigated in the laboratory, including four loading frequencies, four maximum stresses, and four amplitudes. Our experimental results reveal the influence of the three cyclic loading parameters on the mechanical properties of jointed rock models, regarding the fatigue deformation characteristics, the fatigue energy and damage evolution, and the fatigue failure and progressive failure behavior. Under lower loading frequency or higher maximum stress and amplitude, the jointed specimen is characterized by higher fatigue deformation moduli and higher dissipated hysteresis energy, resulting in higher cumulative damage and lower fatigue life. However, the fatigue failure modes of jointed specimens are independent of cyclic loading parameters; all tested jointed specimens exhibit a prominent tensile splitting failure mode. Three different crack coalescence patterns are classified between two adjacent joints. Furthermore, different from the progressive failure under static monotonic loading, the jointed rock specimens under cyclic compression fail more abruptly without evident preceding signs. The tensile cracks on the front surface of jointed specimens always initiate from the joint tips and then propagate at a certain angle with the joints toward the direction of maximum compression.

The role of IL-23 receptor signaling in inflammation-mediated erosive autoimmune arthritis and bone remodeling.

PubMed

Razawy, Wida; van Driel, Marjolein; Lubberts, Erik

2018-02-01

The IL-23/Th17 axis has been implicated in the development of autoimmune diseases, such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA). RA and PsA are heterogeneous diseases with substantial burden on patients. Increasing evidence suggests that the IL-23 signaling pathway may be involved in the development of autoimmunity and erosive joint damage. IL-23 can act either directly or indirectly on bone forming osteoblasts as well as on bone resorbing osteoclasts. As IL-23 regulates the activity of cells of the bone, it is conceivable that in addition to inflammation-mediated joint erosion, IL-23 may play a role in physiological bone remodeling. In this review, we focus on the role of IL-23 in autoimmune arthritis in patients and murine models, and provide an overview of IL-23 producing and responding cells in autoimmune arthritic joints. In addition, we discuss the role of IL-23 on bone forming osteoblasts and bone resorbing osteoclasts regarding inflammation-mediated joint damage and bone remodeling. At last, we briefly discuss the clinical implications of targeting this pathway for joint damage and systemic bone loss in autoimmune arthritis. © 2017 The Authors. European Journal of Immunology published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Loading Analysis of Composite Wind Turbine Blade for Fatigue Life Prediction of Adhesively Bonded Root Joint

NASA Astrophysics Data System (ADS)

Salimi-Majd, Davood; Azimzadeh, Vahid; Mohammadi, Bijan

2015-06-01

Nowadays wind energy is widely used as a non-polluting cost-effective renewable energy resource. During the lifetime of a composite wind turbine which is about 20 years, the rotor blades are subjected to different cyclic loads such as aerodynamics, centrifugal and gravitational forces. These loading conditions, cause to fatigue failure of the blade at the adhesively bonded root joint, where the highest bending moments will occur and consequently, is the most critical zone of the blade. So it is important to estimate the fatigue life of the root joint. The cohesive zone model is one of the best methods for prediction of initiation and propagation of debonding at the root joint. The advantage of this method is the possibility of modeling the debonding without any requirement to the remeshing. However in order to use this approach, it is necessary to analyze the cyclic loading condition at the root joint. For this purpose after implementing a cohesive interface element in the Ansys finite element software, one blade of a horizontal axis wind turbine with 46 m rotor diameter was modelled in full scale. Then after applying loads on the blade under different condition of the blade in a full rotation, the critical condition of the blade is obtained based on the delamination index and also the load ratio on the root joint in fatigue cycles is calculated. These data are the inputs for fatigue damage growth analysis of the root joint by using CZM approach that will be investigated in future work.

[Arthroscopy-guided fracture management. Ankle joint and calcaneus].

PubMed

Schoepp, C; Rixen, D

2013-04-01

Arthroscopic fracture management of the ankle and calcaneus requires a differentiated approach. The aim is to minimize surgical soft tissue damage and to visualize anatomical fracture reduction arthroscopically. Moreover, additional cartilage damage can be detected and treated. The arthroscopic approach is limited by deep impressions of the joint surface needing cancellous bone grafting, by multiple fracture lines on the articular side and by high-grade soft tissue damage. An alternative to the minimally invasive arthroscopic approach is open arthroscopic reduction in conventional osteosynthesis. This facilitates correct assessment of surgical reduction of complex calcaneal fractures, otherwise remaining non-anatomical reduction might not be fluoroscopically detected during surgery.

Maximum-likelihood techniques for joint segmentation-classification of multispectral chromosome images.

PubMed

Schwartzkopf, Wade C; Bovik, Alan C; Evans, Brian L

2005-12-01

Traditional chromosome imaging has been limited to grayscale images, but recently a 5-fluorophore combinatorial labeling technique (M-FISH) was developed wherein each class of chromosomes binds with a different combination of fluorophores. This results in a multispectral image, where each class of chromosomes has distinct spectral components. In this paper, we develop new methods for automatic chromosome identification by exploiting the multispectral information in M-FISH chromosome images and by jointly performing chromosome segmentation and classification. We (1) develop a maximum-likelihood hypothesis test that uses multispectral information, together with conventional criteria, to select the best segmentation possibility; (2) use this likelihood function to combine chromosome segmentation and classification into a robust chromosome identification system; and (3) show that the proposed likelihood function can also be used as a reliable indicator of errors in segmentation, errors in classification, and chromosome anomalies, which can be indicators of radiation damage, cancer, and a wide variety of inherited diseases. We show that the proposed multispectral joint segmentation-classification method outperforms past grayscale segmentation methods when decomposing touching chromosomes. We also show that it outperforms past M-FISH classification techniques that do not use segmentation information.

Histopathologic evaluation of the effects of etodolac in established adjuvant arthritis in rats: evidence for reversal of joint damage.

PubMed

Weichman, B M; Chau, T T; Rona, G

1987-04-01

Histopathologic evaluation of hindpaws from control rats with established adjuvant arthritis showed severe alterations in soft tissue and bone, as well as progressive, moderate-to-severe articular changes. Following treatment with etodolac for 28 days, soft tissue and articular changes were rated mild, and bone changes were rated moderate, but with remodeling. These findings indicate that etodolac partially reversed the joint damage in these rats.

In situ damage detection in frame structures through coupled response measurements

NASA Astrophysics Data System (ADS)

Liu, D.; Gurgenci, H.; Veidt, M.

2004-05-01

Due to the existence of global modes and local modes of the neighbouring members, damage detection on a structure is more challenging than damage on isolated beams. Detection of an artificial circumferential crack on a joint in a frame-like welded structure is studied in this paper using coupled response measurements. Similarity to real engineering structures is maintained in the fabrication of the test frame. Both the chords and the branch members have hollow sections and the branch members have smaller sizes. The crack is created by a hacksaw on a joint where a branch meets the chord. The methodology is first demonstrated on a single hollow section beam. The test results are then presented for the damaged and undamaged frame. The existence of the damage is clearly observable from the experimental results. It is suggested that this approach offers the potential to detect damage in welded structures such as cranes, mining equipment, steel-frame bridges, naval and offshore structures.

Toward a mechanistic understanding of the damage evolution of SnAgCu solder joints in accelerated thermal cycling test

NASA Astrophysics Data System (ADS)

Mahin Shirazi, Sam

Accelerated thermal cycling (ATC) tests are the most commonly used tests for the thermo-mechanical performance assessment of microelectronics assemblies. Currently used reliability models have failed to incorporate the microstructural dependency of lead free solder joint behavior and its microstructure evolution during cycling. Thus, it is essential to have a mechanistic understanding of the effect of cycling parameters on damage evolution and failure of lead free solder joints in ATC. Recrystallization has been identified as the damage rate controlling mechanism in ATC. Usually it takes 1/3 of life for completion of recrystallization regardless of cycling parameters. Thus, the life of the solder joints can be predicted by estimating global recrystallization. The objective of the first part of the study was to examine whether the damage scenario applies in service is the same as the harsh thermal cycling tests (i.e. 0/100 °C and -40/125 °C) commonly used in industry. Microstructure analysis results on a variety of lead free solder SnAgCu assemblies subjected to the both harsh (0/100 °C) and mild (20/80 °C) ATC confirmed similar failure mechanism under the both testing conditions. Sn grain morphology (interlaced versus beach ball) has a significant effect on the thermo-mechanical performance (and thus the model) of the lead free solder joints. The longer thermal cycling lifetime observed in the interlaced solder joints subjected to the ATC compared to the beach ball structure was correlated to the different initial microstructure and the microstructure evolution during cycling. For the modeling proposes, the present study was focused on Sn-Ag-Cu solder joints with either a single Sn grain or beach ball structure. Microstructural analysis results of the simulated thermal cycling experiment revealed that, the life can be approximated as determined by the accumulation of a certain amount of work during the high temperature dwells. Finally the effect of precipitates spacing on acceleration factor was investigated. Results indicated that a smaller initial precipitate spacing would tend to result in a longer life in mild thermal cycling/service (where there is lower stresses). Accordingly, it is essential to incorporate the dependence of damage rate (i.e. recrystallization) on precipitate coarsening in any predictions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henager, Jr., C. H.; Nguyen, Ba N.; Kurtz, Richard J.

The international fusion community has designed a miniature torsion specimen for neutron irradiation studies of joined SiC and SiC/SiC composite materials. For this research, miniature torsion joints based on this specimen design were fabricated using displacement reactions between Si and TiC to produce Ti 3SiC 2 + SiC joints with SiC and tested in torsion-shear prior to and after neutron irradiation. However, many miniature torsion specimens fail out-of-plane within the SiC specimen body, which makes it problematic to assign a shear strength value to the joints and makes it difficult to compare unirradiated and irradiated strengths to determine irradiation effects.more » Finite element elastic damage and elastic–plastic damage models of miniature torsion joints are developed that indicate shear fracture is more likely to occur within the body of the joined sample and cause out-of-plane failures for miniature torsion specimens when a certain modulus and strength ratio between the joint material and the joined material exists. The model results are compared and discussed with regard to unirradiated and irradiated test data for a variety of joint materials. The unirradiated data includes Ti 3SiC 2 + SiC/CVD-SiC joints with tailored joint moduli, and includes steel/epoxy and CVD-SiC/epoxy joints. Finally, the implications for joint data based on this sample design are discussed.« less

Influence of interface ply orientation on fatigue damage of adhesively bonded composite joints

NASA Technical Reports Server (NTRS)

Johnson, W. S.; Mall, S.

1986-01-01

An experimental study of cracked-lap-shear specimens was conducted to determine the influence of adherend stacking sequence on debond initiation and damage growth in a composite-to-composite bonded joint. Specimens consisted of quasi-isotropic graphite/epoxy adherends bonded together with either FM-300 or EC 3445 adhesives. The stacking sequence of the adherends was varied such that 0 deg, 45 deg, or 90 deg plies were present at the adherend-adhesive interfaces. Fatigue damage initiated in the adhesive layer in those specimens with 0 deg and 45 deg interface plies. Damaage initiated in the form of ply cracking in the strap adherend for the specimens with 90 deg interface plies. The fatigue-damage growth was in the form of delamination within the composite adherends for specimens with the 90 deg and 45 deg plies next to the adhesive, while debonding in the adhesive resulted for the specimens with 0 deg plies next to the adhesive. Those joints with the 0 deg and 45 deg plies next to either adhesive has essentially the same fatigue-damage-initiation stress levels. These stress levels were 13 and 71 percent higher, respectively, than those for specimens with 90 deg plies next to the EC 3445 and FM-300 adhesives.

Multi-Scale Computational Modeling of Ni-Base Superalloy Brazed Joints for Gas Turbine Applications

NASA Astrophysics Data System (ADS)

Riggs, Bryan

Brazed joints are commonly used in the manufacture and repair of aerospace components including high temperature gas turbine components made of Ni-base superalloys. For such critical applications, it is becoming increasingly important to account for the mechanical strength and reliability of the brazed joint. However, material properties of brazed joints are not readily available and methods for evaluating joint strength such as those listed in AWS C3.2 have inherent challenges compared with testing bulk materials. In addition, joint strength can be strongly influenced by the degree of interaction between the filler metal (FM) and the base metal (BM), the joint design, and presence of flaws or defects. As a result, there is interest in the development of a multi-scale computational model to predict the overall mechanical behavior and fitness-for-service of brazed joints. Therefore, the aim of this investigation was to generate data and methodology to support such a model for Ni-base superalloy brazed joints with conventional Ni-Cr-B based FMs. Based on a review of the technical literature a multi-scale modeling approach was proposed to predict the overall performance of brazed joints by relating mechanical properties to the brazed joint microstructure. This approach incorporates metallurgical characterization, thermodynamic/kinetic simulations, mechanical testing, fracture mechanics and finite element analysis (FEA) modeling to estimate joint properties based on the initial BM/FM composition and brazing process parameters. Experimental work was carried out in each of these areas to validate the multi-scale approach and develop improved techniques for quantifying brazed joint properties. Two Ni-base superalloys often used in gas turbine applications, Inconel 718 and CMSX-4, were selected for study and vacuum furnace brazed using two common FMs, BNi-2 and BNi-9. Metallurgical characterization of these brazed joints showed two primary microstructural regions; a soft, ductile a-Ni phase that formed at the joint interface and a hard, brittle multi-phase centerline eutectic. CrB and Ni3B type borides were identified in the eutectic region via electron probe micro-analysis, and a boron diffusion gradient was observed in the BM adjacent to the joint. The volume fraction of centerline eutectic was found to be highly dependent on the extent of the boron diffusion that occurred during brazing and therefore a function of the primary process parameters; hold time, temperature, FM/BM composition, and joint gap. Thermo-Calc(TM) and DICTRA(TM) simulations were used to model the BM dissolution, isothermal solidification and phase transformations that occurred during brazing to predict the final joint microstructure based on these process parameters. Good agreement was found between experimental and simulated joint microstructures at various joint gaps demonstrating the application of these simulations for brazed joints. However, thermodynamic/kinetic databases available for brazing FMs were limited. A variety of mechanical testing was performed to determine the mechanical properties of CMSX-4/BNi-2 and IN718/BNi-2 brazed joints including small-scale tensile tests, standard-size butt joints and lap shear tests. Small-scale tensile testing provided a novel method for studying microstructure-property relationships in brazed joints and indicated that both joint strength and ductility decrease significantly with an increase in the volume fraction of centerline eutectic. In-situ observations during small-scale testing also showed strain localization and crack initiation occurs around the hard, eutectic phases in the joint microstructure during loading. The average tensile strength for standard-size IN718/BNi-2 butt joints containing a low volume fraction of centerline eutectic was found to be 152.8 ksi approximately 90% of the BM yield strength (˜170 ksi). The average lap shear FM stress was found to decrease from 70 to 20 ksi for IN718/BNi-2 joints and from 50 to 15 ksi for CMSX-4/BNi-2 as the overlap was increased from 1T to 5T due to non-uniform stress/strain distribution across the joint. Digital image correlation techniques and FEA models of the lap shear brazed joints were developed to assess the strain distributions across the overlap. Results were used to validate the use of damage zone models for predicting the load carrying capacity of lap shear brazed joints and suggest that the damage zone is independent of the overlap length. To account for the presence of flaws and defects in fitness-for-service assessments of brazed joints determination of the average fracture toughness (KIC) is necessary. Currently no standard exists to measure the KIC for brazed joints, so three test methods were evaluated in this investigation on IN718/BNi-2 brazed joints. The compact tension and double cantilever beam test methods were found to give the most conservative KIC values of 16.42 and 14.42 ksivin respectively. Linear-elastic FEA models of the test specimens were used to validate the calculated KIC values. Similar to joint strength the fracture toughness appeared to be strongly influenced by the volume fraction of centerline eutectic phases. (Abstract shortened by ProQuest.).

Basic radiological assessment of synovial diseases: a pictorial essay

PubMed Central

Turan, Aynur; Çeltikçi, Pınar; Tufan, Abdurrahman; Öztürk, Mehmet Akif

2017-01-01

The synovium is a specialized tissue lining the synovial joints, bursae, and tendon sheaths of the body. It is affected by various localized or systemic disorders. Synovial diseases can be classified as inflammatory, infectious, degenerative, traumatic, hemorrhagic, and neoplastic. Damage in other intraarticular structures, particularly cartilages, generally occurs as a part of pathologic processes involving the synovium, leading to irreversible joint destruction. Imaging has an essential role in the early detection of synovial diseases prior to irreversible joint damage. Obtaining and understanding characteristic imaging findings of synovial diseases enables a proper diagnosis for early treatment. This article focuses on the recent literature that is related with the role of imaging in synovial disease. PMID:28638696

Cost-effectiveness of open graded base course with doweled and nondoweled transverse joints : research brief.

DOT National Transportation Integrated Search

2010-09-01

Most of the damage to concrete pavement results from poor drainage, which can lead to increased freeze-thaw damage, and when combined with heavy loading can contribute to cracking, spalling and surface damage that causes driver discomfort from increa...

The OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging (MRI) Scoring System: Updated Recommendations by the OMERACT MRI in Arthritis Working Group.

PubMed

Østergaard, Mikkel; Peterfy, Charles G; Bird, Paul; Gandjbakhch, Frédérique; Glinatsi, Daniel; Eshed, Iris; Haavardsholm, Espen A; Lillegraven, Siri; Bøyesen, Pernille; Ejbjerg, Bo; Foltz, Violaine; Emery, Paul; Genant, Harry K; Conaghan, Philip G

2017-11-01

The Outcome Measures in Rheumatology (OMERACT) Rheumatoid Arthritis (RA) Magnetic Resonance Imaging (MRI) scoring system (RAMRIS), evaluating bone erosion, bone marrow edema/osteitis, and synovitis, was introduced in 2002, and is now the standard method of objectively quantifying inflammation and damage by MRI in RA trials. The objective of this paper was to identify subsequent advances and based on them, to provide updated recommendations for the RAMRIS. MRI studies relevant for RAMRIS and technical and scientific advances were analyzed by the OMERACT MRI in Arthritis Working Group, which used these data to provide updated considerations on image acquisition, RAMRIS definitions, and scoring systems for the original and new RA pathologies. Further, a research agenda was outlined. Since 2002, longitudinal studies and clinical trials have documented RAMRIS variables to have face, construct, and criterion validity; high reliability and sensitivity to change; and the ability to discriminate between therapies. This has enabled RAMRIS to demonstrate inhibition of structural damage progression with fewer patients and shorter followup times than has been possible with conventional radiography. Technical improvements, including higher field strengths and improved pulse sequences, allow higher image resolution and contrast-to-noise ratio. These have facilitated development and validation of scoring methods of new pathologies: joint space narrowing and tenosynovitis. These have high reproducibility and moderate sensitivity to change, and can be added to RAMRIS. Combined scores of inflammation or joint damage may increase sensitivity to change and discriminative power. However, this requires further research. Updated 2016 RAMRIS recommendations and a research agenda were developed.

Outcome predictors of intra-articular glucocorticoid treatment for knee synovitis in patients with rheumatoid arthritis – a prospective cohort study

PubMed Central

2014-01-01

Introduction Intra-articular glucocorticoid treatment (IAGC) is widely used for symptom relief in arthritis. However, knowledge of factors predicting treatment outcome is limited. The aim of the present study was to identify response predictors of IAGC for knee synovitis in patients with rheumatoid arthritis (RA). Methods In this study 121 RA patients with synovitis of the knee were treated with intra-articular injections of 20 mg triamcinolone hexacetonide. They were followed for six months and the rate of clinical relapse was studied. Non-responders (relapse within 6 months) and responders were compared regarding patient characteristics and knee joint damage as determined by the Larsen-Dale index. In addition, matched samples of serum and synovial fluid were analysed for factors reflecting the inflammatory process (C-reactive protein, interleukin 6, tumour necrosis factor alpha, vascular endothelial growth factor), joint tissue turnover (cartilage oligomeric matrix protein, metalloproteinase 3), and autoimmunity (antinuclear antibodies, antibodies against citrullinated peptides, rheumatoid factor). Results During the observation period, 48 knees relapsed (40%). Non-responders had more radiographic joint damage than responders (P = 0.002) and the pre-treatment vascular endothelial growth factor (VEGF) level in synovial fluid was significantly higher in non-responders (P = 0.002). Conclusions Joint destruction is associated with poor outcome of IAGC for knee synovitis in RA. In addition, higher levels of VEGF in synovial fluid are found in non-responders, suggesting that locally produced VEGF is a biomarker for recurrence of synovial hyperplasia and the risk for arthritis relapse. PMID:24950951

The association between patella alta and the prevalence and worsening of structural features of patellofemoral joint osteoarthritis: The Multicenter Osteoarthritis Study

PubMed Central

Stefanik, J.J.; Zhu, Y.; Zumwalt, A.C.; Gross, K.D.; Clancy, M.; Lynch, J. A.; Frey Law, L.A.; Lewis, C.E.; Roemer, F.W.; Powers, C.M.; Guermazi, A.; Felson, D.T.

2010-01-01

Objective To examine the relationship between patella alta and the prevalence and worsening at follow-up of structural features of patellofemoral joint (PFJ) osteoarthritis (OA) on MRI. Methods The Multicenter Osteoarthritis (MOST) Study is a cohort study of persons aged 50-79 years with or at risk for knee OA. Patella alta was measured using the Insall-Salvati ratio (ISR) on the baseline lateral radiograph and cartilage damage, bone marrow lesions (BMLs), and subchondral bone attrition (SBA) were graded on MRI at baseline and at 30 months follow-up in the PFJ. We examined the association of the ISR with the prevalence and worsening of cartilage damage, BMLs, and SBA in the PFJ using logistic regression. Results 907 knees were studied (mean age 62, BMI 30, ISR 1.10), 63% from female subjects. Compared with knees in the lowest ISR quartile at baseline, those in the highest had 2.4 (95% CI 1.7, 3.3), 2.9 (2.0, 4.3), and 3.5 (2.3, 5.5) times the odds of having lateral PFJ cartilage damage, BMLs, and SBA respectively, and 1.5 (95% CI 1.1, 2.0), 1.3 (0.9, 1.8), and 2.2 (1.4, 3.4) times the odds of having medial PFJ cartilage damage, BMLs, and SBA respectively. Similarly, those with high ISRs were also at risk for worsening of cartilage damage and BMLs over time than those with low ISRs. Conclusion A high ISR, indicative of patella alta, is associated with structural features of OA in the PFJ. Additionally, the same knees have increased risk of worsening of these same features over time. PMID:20506169

Brief report: reconstruction of joint hyaline cartilage by autologous progenitor cells derived from ear elastic cartilage.

PubMed

Mizuno, Mitsuru; Kobayashi, Shinji; Takebe, Takanori; Kan, Hiroomi; Yabuki, Yuichiro; Matsuzaki, Takahisa; Yoshikawa, Hiroshi Y; Nakabayashi, Seiichiro; Ik, Lee Jeong; Maegawa, Jiro; Taniguchi, Hideki

2014-03-01

In healthy joints, hyaline cartilage covering the joint surfaces of bones provides cushioning due to its unique mechanical properties. However, because of its limited regenerative capacity, age- and sports-related injuries to this tissue may lead to degenerative arthropathies, prompting researchers to investigate a variety of cell sources. We recently succeeded in isolating human cartilage progenitor cells from ear elastic cartilage. Human cartilage progenitor cells have high chondrogenic and proliferative potential to form elastic cartilage with long-term tissue maintenance. However, it is unknown whether ear-derived cartilage progenitor cells can be used to reconstruct hyaline cartilage, which has different mechanical and histological properties from elastic cartilage. In our efforts to develop foundational technologies for joint hyaline cartilage repair and reconstruction, we conducted this study to obtain an answer to this question. We created an experimental canine model of knee joint cartilage damage, transplanted ear-derived autologous cartilage progenitor cells. The reconstructed cartilage was rich in proteoglycans and showed unique histological characteristics similar to joint hyaline cartilage. In addition, mechanical properties of the reconstructed tissues were higher than those of ear cartilage and equal to those of joint hyaline cartilage. This study suggested that joint hyaline cartilage was reconstructed from ear-derived cartilage progenitor cells. It also demonstrated that ear-derived cartilage progenitor cells, which can be harvested by a minimally invasive method, would be useful for reconstructing joint hyaline cartilage in patients with degenerative arthropathies. © AlphaMed Press.

Structural Damage Detection with Piezoelectric Wafer Active Sensors

NASA Astrophysics Data System (ADS)

Giurgiutiu, Victor

2011-07-01

Piezoelectric wafer active sensors (PWAS) are lightweight and inexpensive enablers for a large class of damage detection and structural health monitoring (SHM) applications. This paper starts with a brief review of PWAS physical principles and basic modelling and continues by considering the various ways in which PWAS can be used for damage detection: (a) embedded guided-wave ultrasonics, i.e., pitch-catch, pulse-echo, phased arrays, thickness mode; (b) high-frequency modal sensing, i.e., the electro-mechanical (E/M) impedance method; (c) passive detection, i.e., acoustic emission and impact detection. An example of crack-like damage detection and localization with PWAS phased arrays on a small metallic plate is given. The modelling of PWAS detection of disbond damage in adhesive joints is achieved with the analytical transfer matrix method (TMM). The analytical methods offer the advantage of fast computation which enables parameter studies and carpet plots. A parametric study of the effect of crack size and PWAS location on disbond detection is presented. The power and energy transduction between PWAS and structure is studied analytically with a wave propagation method. Special attention is given to the mechatronics modeling of the complete transduction cycle from electrical excitation into ultrasonic acoustic waves by the piezoelectric effect, the transfer through the structure, and finally reverse piezoelectric transduction to generate the received electric signal. It is found that the combination of PWAS size and wave frequency/wavelength play an important role in identifying transduction maxima and minima that could be exploited to achieve an optimum power-efficient design. The multi-physics finite element method (MP-FEM), which permits fine discretization of damaged regions and complicated structural geometries, is used to study the generation of guided waves in a plate from an electrically excited transmitter PWAS and the capture of these waves as electric signals at a receiver PWAS. Wave diffraction from a hole damage is illustrated through time-frame snapshots. The paper ends with conclusions and suggestions for further work.

Does metaphyseal cement augmentation in fracture management influence the adjacent subchondral bone and joint cartilage?: an in vivo study in sheep stifle joints.

PubMed

Goetzen, Michael; Hofmann-Fliri, Ladina; Arens, Daniel; Zeiter, Stephan; Stadelmann, Vincent; Nehrbass, Dirk; Richards, R Geoff; Blauth, Michael

2015-01-01

Augmentation of implants with polymethylmethacrylate (PMMA) bone cement in osteoporotic fractures is a promising approach to increase implant purchase. Side effects of PMMA for the metaphyseal bone, particularly for the adjacent subchondral bone plate and joint cartilage, have not yet been studied. The following experimental study investigates whether subchondral PMMA injection compromises the homeostasis of the subchondral bone and/or the joint cartilage.Ten mature sheep were used to simulate subchondral PMMA injection. Follow-ups of 2 (4 animals) and 4 (6 animals) months were chosen to investigate possible cartilage damage and subchondral plate alterations in the knee. Evaluation was completed by means of high-resolution peripheral quantitative computed tomography (HRpQCT) imaging, histopathological osteoarthritis scoring, and determination of glycosaminoglycan content in the joint cartilage. Results were compared with the untreated contralateral knee and statistically analyzed using nonparametric tests.Evaluation of the histological osteoarthritis score revealed no obvious cartilage damage for the treated knee; median histological score after 2 months 0 (range 4), after 4 months 1 (range 5). There was no significant difference when compared with the untreated control site after 2 and 4 months (P = 0.23 and 0.76, respectively). HRpQCT imaging showed no damage to the metaphyseal trabeculae. Glycosaminoglycan measurements of the treated joint cartilage after 4 months revealed no significant difference compared with the untreated cartilage (P = 0.24).The findings of this study support initial clinical observation that PMMA implant augmentation of metaphyseal fractures appears to be a safe procedure for fixation without harming the subchondral bone plate and adjacent joint cartilage.

Accuracy of magnetic resonance imaging to detect cartilage loss in severe osteoarthritis of the first carpometacarpal joint: comparison with histological evaluation.

PubMed

Saltzherr, Michael S; Coert, J Henk; Selles, Ruud W; van Neck, Johan W; Jaquet, Jean-Bart; van Osch, Gerjo J V M; Oei, Edwin H G; Luime, Jolanda J; Muradin, Galied S R

2017-03-14

Magnetic resonance imaging (MRI) is increasingly used for research in hand osteoarthritis, but imaging the thin cartilage layers in the hand joints remains challenging. We therefore assessed the accuracy of MRI in detecting cartilage loss in patients with symptomatic osteoarthritis of the first carpometacarpal (CMC1) joint. Twelve patients scheduled for trapeziectomy to treat severe symptomatic osteoarthritis of the CMC1 joint underwent a preoperative high resolution 3D spoiled gradient (SPGR) MRI scan. Subsequently, the resected trapezium was evaluated histologically. The sections were scored for cartilage damage severity (Osteoarthritis Research Society International (OARSI) score), and extent of damage (percentage surface area). Each MRI scan was scored for the area of normal cartilage, partial cartilage loss and full cartilage loss. The percentages of the total surface area with any cartilage loss and full-thickness cartilage loss were calculated using MRI and histological evaluation. MRI and histological evaluation both identified large areas of overall cartilage loss. The median (IQR) surface area of any cartilage loss on MRI was 98% (82-100%), and on histological assessment 96% (87-98%). However, MRI underestimated the extent of full-thickness cartilage loss. The median (IQR) surface area of full-thickness cartilage loss on MRI was 43% (22-70%), and on histological evaluation 79% (67-85%). The difference was caused by a thin layer of high signal on the articulating surface, which was interpreted as damaged cartilage on MRI but which was not identified on histological evaluation. Three-dimensional SPGR MRI of the CMC1 joint demonstrates overall cartilage damage, but underestimates full-thickness cartilage loss in patients with advanced osteoarthritis.

Hip Replacement: MedlinePlus Health Topic

MedlinePlus

... damage. The most common cause of damage is osteoarthritis . Osteoarthritis causes pain, swelling, and reduced motion in your ... Food and Drug Administration) Genetics Genetics Home Reference: osteoarthritis (National Library of Medicine) Images Hip joint replacement - ...

Three-Dimensional Geometric Nonlinear Contact Stress Analysis of Riveted Joints

NASA Technical Reports Server (NTRS)

Shivakumar, Kunigal N.; Ramanujapuram, Vivek

1998-01-01

The problems associated with fatigue were brought into the forefront of research by the explosive decompression and structural failure of the Aloha Airlines Flight 243 in 1988. The structural failure of this airplane has been attributed to debonding and multiple cracking along the longitudinal lap splice riveted joint in the fuselage. This crash created what may be termed as a minor "Structural Integrity Revolution" in the commercial transport industry. Major steps have been taken by the manufacturers, operators and authorities to improve the structural airworthiness of the aging fleet of airplanes. Notwithstanding, this considerable effort there are still outstanding issues and concerns related to the formulation of Widespread Fatigue Damage which is believed to have been a contributing factor in the probable cause of the Aloha accident. The lesson from this accident was that Multiple-Site Damage (MSD) in "aging" aircraft can lead to extensive aircraft damage. A strong candidate in which MSD is highly probable to occur is the riveted lap joint.

Effect of Retrograde Reaming for Tibiotalocalcaneal Arthrodesis on Subtalar Joint Destruction: A Cadaveric Study.

PubMed

Lowe, Jason A; Routh, Lucas K; Leary, Jeffrey T; Buzhardt, Paul C

2016-01-01

Recent published data have suggested successful union of subtalar and tibiotalar joints without formal debridement during tibiotalocalcaneal (TTC) fusion procedures. Although previous studies have reported on the importance of the proper guidewire starting point and trajectory to obtain appropriate hindfoot alignment for successful fusion, to our knowledge, no studies have quantified the amount of articular damage to the subtalar joint with retrograde reaming. We hypothesized that reaming would destroy >50% of the posterior facet of the subtalar joint. The bilateral lower extremities of 5 cadavers were obtained and the subtalar joints exposed. Retrograde TTC nail guidewires were inserted, and a 12-mm reamer was passed through the subtalar and ankle joints. Pre- and postreaming images of the subtalar joint were obtained to compare the amount of joint destruction after reaming. We found an average of 5.89% articular destruction of the talar posterior facet and an average of 4.01% articular destruction of the posterior facet of the calcaneus. No damage to the middle facets of the subtalar joint was observed. TTC nailing is a successful procedure for ankle and subtalar joint fusion. Published studies have reported successful subtalar union using TTC nailing without formal open debridement of the subtalar joint, preserving the soft tissue envelope. TTC nail insertion using a 12-mm reamer will destroy 5.89% and 4.01% of the respective talar and calcaneal posterior facets of the subtalar joint. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Sulforaphane Modulates Joint Inflammation in a Murine Model of Complete Freund's Adjuvant-Induced Mono-Arthritis.

PubMed

Silva Rodrigues, João Francisco; Silva E Silva, Cristiane; França Muniz, Thayanne; de Aquino, Alana Fernanda; Neuza da Silva Nina, Larissa; Fialho Sousa, Nagila Caroline; Nascimento da Silva, Luis Claudio; de Souza, Breno Glaessner Gomes Fernandes; da Penha, Tatiana Aranha; Abreu-Silva, Ana Lúcia; de Sá, Joicy Cortez; Soares Fernandes, Elizabeth; Grisotto, Marcos Augusto Grigolin

2018-04-24

Rheumatoid arthritis (RA) is characterized by inflammation of one or more joints, and affects ~1% of the adult population worldwide. Sulforaphane (SFN) is a natural compound that has been suggested as an antioxidant. Here, SFN’s effects were evaluated in a murine mono-arthritis model. Mono-arthritis was induced in mice by a single intra-articular injection of Complete Freund’s Adjuvant (CFA-10 µg/joint, in 10 µL) into the ipsilateral joint. The contralateral joint received an equal volume of PBS. On the 4th day post-joint inflammation induction, animals received either SFN (10 mg/kg) or vehicle (3% DMSO in saline), intraperitoneally (i.p.), twice a day for 3 days. Joint swelling and secondary mechanical allodynia and hyperalgesia were evaluated over 7 days post-CFA. After this period, animals were culled and their blood and synovial fluid samples were collected for analysis of cell populations, cytokine release and thioredoxin reductase (TrxR) activity. Knee joint samples were also collected for histology. SFN reduced joint swelling and damage whilst increasing the recruitment of Ly6C⁺ and Ly6G⁺ cells to CFA-injected joints. SFN-treated animals presented down-regulation of CD11b and CD62L on synovial fluid Ly6G⁺ cells. Synovial fluid samples obtained from CFA-injected joints and plasma samples of SFN-treated mice presented higher levels of IL-6 and increased activity of TrxR, in comparison with controls. These results indicate that SFN reduces knee joint damage by modulating cell activation/migration to the joints, cytokine production and increasing the activity of TrxR, and therefore, may represent an alternative treatment to joint inflammation.

Evaluation of the novel avocado/soybean unsaponifiable Arthrocen to alter joint pain and inflammation in a rat model of osteoarthritis

PubMed Central

Goudarzi, Ramin; Reid, Allison

2018-01-01

Background Avocado/soybean unsaponifiables such as Arthrocen have been reported to reduce cartilage catabolism and chondrocytic synthesis of inflammatory mediators associated with osteoarthritis (OA). While there is some clinical evidence that avocado/soybean unsaponifiables can reduce OA pain, no preclinical studies have corroborated this observation. The present study determined whether addition of an avocado/soybean unsaponifiable (Arthrocen) to the drinking water of OA rats reduced direct and referred joint pain. Methods OA was induced in male Wistar rats by intra-articular injection of sodium monoiodoacetate (MIA: 0.3mg) and animals were allowed to recover for 14 days. Arthrocen was added to the drinking water which was available to animals ad libitum. On day 30, joint pain was assessed by dynamic incapacitance while referred pain was determined by von Frey hair algesiometry. Results The joint damage induced by MIA injection was severe and was consistent with end-stage OA. Arthrocen consumption (approximately 35 mg/day) attenuated the joint oedema associated with MIA injection. Hindlimb weight bearing also significantly improved in Arthrocen-treated rats (P<0.05); however, von Frey hair mechanosensitivity was unaffected by this treatment. Conclusions These data indicate that Arthrocen has the potential to reduce joint inflammation and pain associated with end-stage OA. PMID:29489828

Modeling and testing miniature torsion specimens for SiC joining development studies for fusion

DOE PAGES

Henager, Jr., C. H.; Nguyen, Ba N.; Kurtz, Richard J.; ...

2015-08-05

The international fusion community has designed a miniature torsion specimen for neutron irradiation studies of joined SiC and SiC/SiC composite materials. For this research, miniature torsion joints based on this specimen design were fabricated using displacement reactions between Si and TiC to produce Ti 3SiC 2 + SiC joints with SiC and tested in torsion-shear prior to and after neutron irradiation. However, many miniature torsion specimens fail out-of-plane within the SiC specimen body, which makes it problematic to assign a shear strength value to the joints and makes it difficult to compare unirradiated and irradiated strengths to determine irradiation effects.more » Finite element elastic damage and elastic–plastic damage models of miniature torsion joints are developed that indicate shear fracture is more likely to occur within the body of the joined sample and cause out-of-plane failures for miniature torsion specimens when a certain modulus and strength ratio between the joint material and the joined material exists. The model results are compared and discussed with regard to unirradiated and irradiated test data for a variety of joint materials. The unirradiated data includes Ti 3SiC 2 + SiC/CVD-SiC joints with tailored joint moduli, and includes steel/epoxy and CVD-SiC/epoxy joints. Finally, the implications for joint data based on this sample design are discussed.« less

S100A8/A9 as a biomarker for synovial inflammation and joint damage in patients with rheumatoid arthritis.

PubMed

Kang, Kwi Young; Woo, Jung-Won; Park, Sung-Hwan

2014-01-01

S100A8 and S100A9 are major leukocyte proteins, known as damage-associated molecular patterns, found at high concentrations in the synovial fluid of patients with rheumatoid arthritis (RA). A heterodimeric complex of S100A8/A9 is secreted by activated leukocytes and binds to Toll-like receptor 4, which mediates downstream signaling and promotes inflammation and autoimmunity. Serum and synovial fluid levels of S100A8/A9 are markedly higher in patients with RA than in patients with osteoarthritis or miscellaneous inflammatory arthritis. Serum levels of S100A8/A9 are significantly correlated with clinical and laboratory markers of inflammation, such as C-reactive protein, erythrocyte sedimentation rate, rheumatoid factor, and the Disease Activity Score for 28 joints. Significant correlations have also been found between S100A8/A9 and radiographic and clinical assessments of joint damage, such as hand radiographs and the Rheumatoid Arthritis Articular Damage score. In addition, among known inflammatory markers, S100A8/A9 has the strongest correlation with total sum scores of ultrasonography assessment. Furthermore, baseline levels of S100A8/A9 are independently associated with progression of joint destruction in longitudinal studies and are responsive to change during conventional and biologic treatments. These findings suggest S100A8/A9 to be a valuable diagnostic and prognostic biomarker for RA.

Quantitative power Doppler ultrasound measures of peripheral joint synovitis in poor prognosis early rheumatoid arthritis predict radiographic progression.

PubMed

Sreerangaiah, Dee; Grayer, Michael; Fisher, Benjamin A; Ho, Meilien; Abraham, Sonya; Taylor, Peter C

2016-01-01

To assess the value of quantitative vascular imaging by power Doppler US (PDUS) as a tool that can be used to stratify patient risk of joint damage in early seropositive RA while still biologic naive but on synthetic DMARD treatment. Eighty-five patients with seropositive RA of <3 years duration had clinical, laboratory and imaging assessments at 0 and 12 months. Imaging assessments consisted of radiographs of the hands and feet, two-dimensional (2D) high-frequency and PDUS imaging of 10 MCP joints that were scored for erosions and vascularity and three-dimensional (3D) PDUS of MCP joints and wrists that were scored for vascularity. Severe deterioration on radiographs and ultrasonography was seen in 45 and 28% of patients, respectively. The 3D power Doppler volume and 2D vascularity scores were the most useful US predictors of deterioration. These variables were modelled in two equations that estimate structural damage over 12 months. The equations had a sensitivity of 63.2% and specificity of 80.9% for predicting radiographic structural damage and a sensitivity of 54.2% and specificity of 96.7% for predicting structural damage on ultrasonography. In seropositive early RA, quantitative vascular imaging by PDUS has clinical utility in predicting which patients will derive benefit from early use of biologic therapy. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Analysis of EDZ Development of Columnar Jointed Rock Mass in the Baihetan Diversion Tunnel

NASA Astrophysics Data System (ADS)

Hao, Xian-Jie; Feng, Xia-Ting; Yang, Cheng-Xiang; Jiang, Quan; Li, Shao-Jun

2016-04-01

Due to the time dependency of the crack propagation, columnar jointed rock masses exhibit marked time-dependent behaviour. In this study, in situ measurements, scanning electron microscope (SEM), back-analysis method and numerical simulations are presented to study the time-dependent development of the excavation damaged zone (EDZ) around underground diversion tunnels in a columnar jointed rock mass. Through in situ measurements of crack propagation and EDZ development, their extent is seen to have increased over time, despite the fact that the advancing face has passed. Similar to creep behaviour, the time-dependent EDZ development curve also consists of three stages: a deceleration stage, a stabilization stage, and an acceleration stage. A corresponding constitutive model of columnar jointed rock mass considering time-dependent behaviour is proposed. The time-dependent degradation coefficient of the roughness coefficient and residual friction angle in the Barton-Bandis strength criterion are taken into account. An intelligent back-analysis method is adopted to obtain the unknown time-dependent degradation coefficients for the proposed constitutive model. The numerical modelling results are in good agreement with the measured EDZ. Not only that, the failure pattern simulated by this time-dependent constitutive model is consistent with that observed in the scanning electron microscope (SEM) and in situ observation, indicating that this model could accurately simulate the failure pattern and time-dependent EDZ development of columnar joints. Moreover, the effects of the support system provided and the in situ stress on the time-dependent coefficients are studied. Finally, the long-term stability analysis of diversion tunnels excavated in columnar jointed rock masses is performed.

Flight Set 360L006 STS-34 field joint protection system, thermal protection system, and systems tunnel components, volume 4

NASA Technical Reports Server (NTRS)

Wilkinson, J. P.

1990-01-01

The performance of the thermal protection system, field joint protection system, and systems tunnel components of Flight Set 360L006, are documented, as evaluated by postflight hardware inspection. The condition of both motors was similar to previous flights. Sixteen aft edge hits were noted on the ground environment instrumentation thermal protection system. Each hit left a clean substrate, indicating that the damage was caused by nozzle severance debris and/or water impact. No National Space and Transporation System debris criteria for missing thermal protection system were violated. One 5.0 by 1.0 in. unbond was observed on the left hand center field joint K5NA closeout and was elevated to an in-flight anomaly (STS-34-M-4) by the NASA Ice/Debris team. Aft edge damage to the K5NA and an associated black streak indicate that burning debris from the nozzle severance system was the likely cause of the damage. Minor divots caused by debris were seen on previous flights, but this is the first occurrence of a K5NA unbond. Since the unbond occurred after booster separation there is no impact on flight safety and no corrective actions was taken. The right hand center field joint primary heater failed the dielectric withstanding voltage test after joint closeout. The heater was then disabled by opening the circuit breaker, and the redundant heater was used. The redundant heater performed nominally during the launch countdown. A similar condition occurred on Flight 4 when a secondary joint heater failed the dielectric withstanding voltage test.

Experimental investigation of reinforced bonded joints for composite laminates.

PubMed

Bisagni, Chiara; Furfari, Domenico; Pacchione, Marco

2018-02-01

An experimental study has been carried out to investigate the behaviour of co-bonded carbon fibre reinforced plastics joints with a novel design incorporating a through the thickness local reinforcement. Different specimens were manufactured to investigate static and fatigue behaviour, as well as delamination size after impact and damage tolerance characteristics. The mechanical performances of the specimens with local reinforcement, consisting of the insertion of spiked thin metal sheets between co-bonded laminates, were compared with those ones obtained from specimens with purely co-bonded joints. This novel design demonstrated by tests that damage progression under cycling load results significantly delayed by the reinforcements. A significant number of experimental results were obtained that can be used to define preliminary design guidelines.

Experimental investigation of reinforced bonded joints for composite laminates

PubMed Central

Bisagni, Chiara; Furfari, Domenico; Pacchione, Marco

2017-01-01

An experimental study has been carried out to investigate the behaviour of co-bonded carbon fibre reinforced plastics joints with a novel design incorporating a through the thickness local reinforcement. Different specimens were manufactured to investigate static and fatigue behaviour, as well as delamination size after impact and damage tolerance characteristics. The mechanical performances of the specimens with local reinforcement, consisting of the insertion of spiked thin metal sheets between co-bonded laminates, were compared with those ones obtained from specimens with purely co-bonded joints. This novel design demonstrated by tests that damage progression under cycling load results significantly delayed by the reinforcements. A significant number of experimental results were obtained that can be used to define preliminary design guidelines. PMID:29568127

Review of Vibration-Based Helicopters Health and Usage Monitoring Methods

DTIC Science & Technology

2001-04-05

FM4, NA4, NA4*, NB4 and NB48* (Polyshchuk et al., 1998). The Wigner - Ville distribution ( WVD ) is a joint time-frequency signal analysis. The WVD is one...signal processing methodologies that are of relevance to vibration based damage detection (e.g., Wavelet Transform and Wigner - Ville distribution ) will be...operation cost, reduce maintenance flights, and increase flight safety. Key Words: HUMS; Wavelet Transform; Wigner - Ville distribution ; O&S; Machinery

Monitoring of bolted joints using piezoelectric active-sensing for aerospace applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Gyuhae; Farrar, Charles R; Park, Chan - Yik

2010-01-01

This paper is a report of an initial investigation into tracking and monitoring the integrity of bolted joints using piezoelectric active-sensors. The target application of this study is a fitting lug assembly of unmanned aerial vehicles (UAVs), where a composite wing is mounted to a UAV fuselage. The SHM methods deployed in this study are impedance-based SHM techniques, time-series analysis, and high-frequency response functions measured by piezoelectric active-sensors. Different types of simulated damage are introduced into the structure, and the capability of each technique is examined and compared. Additional considerations encountered in this initial investigation are made to guide furthermore » thorough research required for the successful field deployment of this technology.« less

30 CFR 220.011 - Schedule of allowable direct and allocable joint costs and credits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... household applicances, and purchases of insurance against damages to or loss of personal property are... approval. (h) Damages and losses to NPSL property. All costs necessary for the repair or replacement of NPSL property made necessary because of damages or losses incurred by fire, flood, storm, theft...

Demonstrating damage tolerance of composite airframes

NASA Technical Reports Server (NTRS)

Poe, Clarence C., Jr.

1993-01-01

Commercial transport aircraft operating in the United States are certified by the Federal Aviation Authority to be damage tolerant. On 28 April 1988, Aloha Airlines Flight 243, a Boeing 727-200 airplane, suffered an explosive decompression of the fuselage but landed safely. This event provides very strong justification for the damage tolerant design criteria. The likely cause of the explosive decompression was the linkup of numerous small fatigue cracks that initiated at adjacent fastener holes in the lap splice joint at the side of the body. Actually, the design should have limited the damage size to less than two frame spacings (about 40 inches), but this type of 'multi-site damage' was not originally taken into account. This cracking pattern developed only in the high-time airplanes (many flights). After discovery in the fleet, a stringent inspection program using eddy current techniques was inaugurated to discover these cracks before they linked up. Because of concerns about safety and the maintenance burden, the lap-splice joints of these high-time airplanes are being modified to remove cracks and prevent new cracking; newer designs account for 'multi-site damage'.

Exercise may decrease further destruction in the adult haemophilic joint.

PubMed

Harris, S; Boggio, L N

2006-05-01

The effect of exercise on adult haemophilic joints was investigated. Forty-six subjects with existing joint disease were evaluated and range of motion (ROM) in joints was measured. The effect of exercise of large joint ROM in haemophilia was evaluated by comparing the ranges of motion in subjects who exercised at least three times weekly against those subjects who did not exercise. The exercise group showed improvement in the majority of joint ranges of motion compared with the non-exercise group (P = 0.003). Thus regular exercise may help reduce further destruction in haemophilic joints by strengthening muscle ligaments and tendons surrounding the joint thereby protecting them from damage caused by recurrent haemarthrotic events.

Osteoarthritis year in review 2014: mechanics--basic and clinical studies in osteoarthritis.

PubMed

Moyer, R F; Ratneswaran, A; Beier, F; Birmingham, T B

2014-12-01

The purpose of this review was to highlight recent research in mechanics and osteoarthritis (OA) by summarizing results from selected studies spanning basic and clinical research methods. Databases were searched from January 2013 through to March 2014. Working in pairs, reviewers selected 67 studies categorized into four themes--mechanobiology, ambulatory mechanics, biomechanical interventions and mechanical risk factors. Novel developments in mechanobiology included the identification of cell signaling pathways that mediated cellular responses to loading of articular cartilage. Studies in ambulatory mechanics included an increased focus on instrumented knee implants and progress in computational models, both emphasizing the importance of muscular contributions to load. Several proposed biomechanical interventions (e.g., shoe insoles and knee braces) produced variable changes in external knee joint moments during walking, while meta-analysis of randomized clinical trials did not support the use of lateral wedge insoles for decreasing pain. Results from high quality randomized trials suggested diet with or without exercise decreased indicators of knee joint load during walking, whereas similar effects from exercise alone were not detected with the measures used. Data from longitudinal cohorts suggested mechanical alignment was a risk factor for incidence and progression of OA, with the mechanism involving damage to the meniscus. In combination, the basic and clinical studies highlight the importance of considering multiple contributors to joint loading that can evoke both protective and damaging responses. Although challenges clearly exist, future studies should strive to integrate basic and clinical research methods to gain a greater understanding of the interactions among mechanical factors in OA and to develop improved preventive and therapeutic strategies. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Natural progression of blood-induced joint damage in patients with haemophilia: clinical relevance and reproducibility of three-dimensional gait analysis.

PubMed

Lobet, S; Detrembleur, C; Francq, B; Hermans, C

2010-09-01

A major complication in haemophilia is the destruction of joint cartilage because of recurrent intraarticular and intramuscular bleeds. Therefore, joint assessment is critical to quantify the extent of joint damage, which has traditionally been evaluated using both radiological and clinical joint scores. Our study aimed to evaluate the natural progression of haemophilic arthopathy using three-dimensional gait analysis (3DGA) and to assess the reproducibility of this technique. We hypothesized that the musculoskeletal function was relatively stable in patients with haemophilia. Eighteen adults with established haemophilic arthropathies were evaluated twice by 3DGA (mean follow-up: 18 +/- 5 weeks). Unexpectedly, our findings revealed infraclinical deterioration of gait pattern, characterized by a 3.2% decrease in the recovery index, which is indicative of the subject's ability to save energy while walking. A tendency towards modification of segmental joint function was also observed. Gait analysis was sufficiently reproducible with regards to spatiotemporal parameters as well as kinetic, mechanical and energetic gait variables. The kinematic variables were reproducible in both the sagittal and frontal planes. In conclusion, 3DGA is a reproducible tool to assess abnormal gait patterns and monitor natural disease progression in haemophilic patients.

The research and development of damage tolerant carbon fiber composites

NASA Astrophysics Data System (ADS)

Miranda, John Armando

This record of study takes a first hand look at corporate research and development efforts to improve the damage tolerance of two unique composite materials used in high performance aerospace applications. The professional internship with The Dow Chemical Company---Dow/United Technologies joint venture describes the intern's involvement in developing patentable process technologies for interleave toughening of high temperature resins and their composites. The subsequent internship with Hexcel Corporation describes the intern's involvement in developing the damage tolerance of novel and existing honeycomb sandwich structure technologies. Through the Doctor of Engineering professional internship experience this student exercised fundamental academic understanding and methods toward accomplishing the corporate objectives of the internship sponsors in a resource efficient and cost-effective manner. Also, the student gained tremendous autonomy through exceptional training in working in focused team environments with highly trained engineers and scientists in achieving important corporate objectives.

Numerical damage models using a structural approach: application in bones and ligaments

NASA Astrophysics Data System (ADS)

Arnoux, P. J.; Bonnoit, J.; Chabrand, P.; Jean, M.; Pithioux, M.

2002-01-01

The purpose of the present study was to apply knowledge of structural properties to perform numerical simulations with models of bones and knee ligaments exposed to dynamic tensile loading leading to tissue damage. Compact bones and knee ligaments exhibit the same geometrical pattern in their different levels of structural hierarchy from the tropocollagen molecule to the fibre. Nevertheless, their mechanical behaviours differ considerably at the fibril level. These differences are due to the contribution of the joints in the microfibril-fibril-fibre assembly and to the mechanical properties of the structural components. Two finite element models of the fibrous bone and ligament structure were used to describe damage in terms of elastoplastic laws or joint decohesion processes.

Articular cartilage. Part II. The osteoarthritic joint.

PubMed

Muehleman, C; Arsenis, C H

1995-05-01

Articular hyaline cartilage, though a metabolically active tissue, has limited capacity for repair. Though the integrity of the cartilage is dependent upon a certain level of force placed upon it, excessive force leads to damage. It is when the breakdown of the cartilage exceeds the capacity of the cartilage for repair that osteoarthritis results. At present, pharmacologic treatment of osteoarthritis is focused toward the control of pain and stiffness. This treatment, however, masks the symptoms of the disease and effectively allows the patient to do further damage to the joint.

NEUTRON RADIATION DAMAGE IN CCD CAMERAS AT JOINT EUROPEAN TORUS (JET).

PubMed

Milocco, Alberto; Conroy, Sean; Popovichev, Sergey; Sergienko, Gennady; Huber, Alexander

2017-10-26

The neutron and gamma radiations in large fusion reactors are responsible for damage to charged couple device (CCD) cameras deployed for applied diagnostics. Based on the ASTM guide E722-09, the 'equivalent 1 MeV neutron fluence in silicon' was calculated for a set of CCD cameras at the Joint European Torus. Such evaluations would be useful to good practice in the operation of the video systems. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Joint Inversion of 3d Mt/gravity/magnetic at Pisagua Fault.

NASA Astrophysics Data System (ADS)

Bascur, J.; Saez, P.; Tapia, R.; Humpire, M.

2017-12-01

This work shows the results of a joint inversion at Pisagua Fault using 3D Magnetotellurics (MT), gravity and regional magnetic data. The MT survey has a poor coverage of study area with only 21 stations; however, it allows to detect a low resistivity zone aligned with the Pisagua Fault trace that it is interpreted as a damage zone. The integration of gravity and magnetic data, which have more dense sampling and coverage, adds more detail and resolution to the detected low resistivity structure and helps to improve the structure interpretation using the resulted models (density, magnetic-susceptibility and electrical resistivity). The joint inversion process minimizes a multiple target function which includes the data misfit, model roughness and coupling norms (crossgradient and direct relations) for all geophysical methods considered (MT, gravity and magnetic). This process is solved iteratively using the Gauss-Newton method which updates the model of each geophysical method improving its individual data misfit, model roughness and the coupling with the other geophysical models. For solving the model updates of magnetic and gravity methods were developed dedicated 3D inversion software codes which include the coupling norms with additionals geophysical parameters. The model update of the 3D MT is calculated using an iterative method which sequentially filters the priority model and the output model of a single 3D MT inversion process for obtaining the resistivity model coupled solution with the gravity and magnetic methods.

Exploring the existence of a stayer population with mover-stayer counting process models: application to joint damage in psoriatic arthritis.

PubMed

Yiu, Sean; Farewell, Vernon T; Tom, Brian D M

2017-08-01

Many psoriatic arthritis patients do not progress to permanent joint damage in any of the 28 hand joints, even under prolonged follow-up. This has led several researchers to fit models that estimate the proportion of stayers (those who do not have the propensity to experience the event of interest) and to characterize the rate of developing damaged joints in the movers (those who have the propensity to experience the event of interest). However, when fitted to the same data, the paper demonstrates that the choice of model for the movers can lead to widely varying conclusions on a stayer population, thus implying that, if interest lies in a stayer population, a single analysis should not generally be adopted. The aim of the paper is to provide greater understanding regarding estimation of a stayer population by comparing the inferences, performance and features of multiple fitted models to real and simulated data sets. The models for the movers are based on Poisson processes with patient level random effects and/or dynamic covariates, which are used to induce within-patient correlation, and observation level random effects are used to account for time varying unobserved heterogeneity. The gamma, inverse Gaussian and compound Poisson distributions are considered for the random effects.

Monitoring of fatigue damage in composite lap-joints using guided waves and FBG sensors

NASA Astrophysics Data System (ADS)

Karpenko, Oleksii; Khomenko, Anton; Koricho, Ermias; Haq, Mahmoodul; Udpa, Lalita

2016-02-01

Adhesive bonding is being increasingly employed in many applications as it offers possibility of light-weighting and efficient multi-material joining along with reduction in time and cost of manufacturing. However, failure initiation and progression in critical components like joints, specifically in fatigue loading is not well understood, which necessitates reliable NDE and SHM techniques to ensure structural integrity. In this work, concurrent guided wave (GW) and fiber Bragg grating (FBG) sensor measurements were used to monitor fatigue damage in adhesively bonded composite lap-joints. In the present set-up, one FBG sensor was strategically embedded in the adhesive bond-line of a lap-joint, while two other FBGs were bonded on the surface of the adherends. Full spectral responses of FBG sensors were collected and compared at specific intervals of fatigue loading. In parallel, guided waves were actuated and sensed using PZT wafers mounted on the composite adherends. Experimental results demonstrated that time-of-flight (ToF) of the fundamental modes transmitted through the bond-line and spectral response of FBG sensors were sensitive to fatigue loading and damage. Combination of guided wave and FBG measurements provided the desired redundancy and synergy in the data to evaluate the degradation in bond-line properties. Measurements taken in the presence of continuously applied load replicated the in-situ/service conditions. The approach shows promise in understanding the behavior of bonded joints subjected to complex loading.

The effect of fatigue cracks on fastener flexibility, load distribution, and fatigue crack growth

NASA Astrophysics Data System (ADS)

Whitman, Zachary Layne

Fatigue cracks typically occur at stress risers such as geometry changes and holes. This type of failure has serious safety and economic repercussions affecting structures such as aircraft. The need to prevent catastrophic failure due to fatigue cracks and other discontinuities has led to durability and damage tolerant methodologies influencing the design of aircraft structures. Holes in a plate or sheet filled with a fastener are common fatigue critical locations in aircraft structure requiring damage tolerance analysis (DTA). Often, the fastener is transferring load which leads to a loading condition involving both far-field stresses such as tension and bending, and localized bearing at the hole. The difference between the bearing stress and the tensile field at the hole is known as load transfer. The ratio of load transfer as well as the magnitude of the stresses plays a significant part in how quickly a crack will progress to failure. Unfortunately, the determination of load transfer in a complex joint is far from trivial. Many methods exist in the open literature regarding the analysis of splices, doublers and attachment joints to determine individual fastener loads. These methods work well for static analyses but greater refinement is needed for crack growth analysis. The first fastener in a splice or joint is typically the most critical but different fastener flexibility equations will all give different results. The constraint of the fastener head and shop end, along with the type of fastener, affects the stiffness or flexibility of the fastener. This in turn will determine the load that the fastener will transfer within a given fastener pattern. However, current methods do not account for the change in flexibility at a fastener as the crack develops. It is put forth that a crack does indeed reduce the stiffness of a fastener by changing its constraint, thus lessening the load transfer. A crack growth analysis utilizing reduced load transfer will result in a slower growing crack versus an analysis that ignores the effect.

Non-terminal animal model of post-traumatic osteoarthritis induced by acute joint injury

PubMed Central

Boyce, Mary K.; Trumble, Troy N.; Carlson, Cathy S.; Groschen, Donna M.; Merritt, Kelly A.; Brown, Murray P.

2013-01-01

Objective Develop a non-terminal animal model of acute joint injury that demonstrates clinical and morphological evidence of early post-traumatic osteoarthritis (PTOA). Methods An osteochondral (OC) fragment was created arthroscopically in one metacarpophalangeal (MCP) joint of 11 horses and the contralateral joint was sham operated. Eleven additional horses served as unoperated controls. Every 2 weeks, force plate analysis, flexion response, joint circumference, and synovial effusion scores were recorded. At weeks 0 and 16, radiographs (all horses) and arthroscopic videos (OC injured and sham joints) were graded. At week 16, synovium and cartilage biopsies were taken arthroscopically from OC injured and sham joints for histologic evaluation and the OC fragment was removed. Results Osteochondral fragments were successfully created and horses were free of clinical lameness after fragment removal. Forelimb gait asymmetry was observed at week 2 (P=0.0012), while joint circumference (P<0.0001) and effusion scores (P<0.0001) were increased in injured limbs compared to baseline from weeks 2 to 16. Positive flexion response of injured limbs was noted at multiple time points. Capsular enthesophytes were seen radiographically in injured limbs. Articular cartilage damage was demonstrated arthroscopically as mild wear-lines and histologically as superficial zone chondrocyte death accompanied by mild proliferation. Synovial hyperemia and fibrosis were present at the site of OC injury. Conclusion Acute OC injury to the MCP joint resulted in clinical, imaging, and histologic changes in cartilage and synovium characteristic of early PTOA. This model will be useful for defining biomarkers of early osteoarthritis and for monitoring response to therapy and surgery. PMID:23467035

Corrosion Damage and Wear Mechanisms in Long-Term Retrieved CoCr Femoral Components for Total Knee Arthroplasty.

PubMed

Arnholt, Christina M; MacDonald, Daniel W; Malkani, Arthur L; Klein, Gregg R; Rimnac, Clare M; Kurtz, Steven M; Kocagoz, Sevi B; Gilbert, Jeremy L

2016-12-01

Metal debris and ion release has raised concerns in joint arthroplasty. The purpose of this study was to characterize the sources of metallic ions and particulate debris released from long-term (in vivo >15 years) total knee arthroplasty femoral components. A total of 52 CoCr femoral condyles were identified as having been implanted for more than 15 years. The femoral components were examined for incidence of 5 types of damage (metal-on-metal wear due to historical polyethylene insert failure, mechanically assisted crevice corrosion at taper interfaces, cement interface corrosion, third-body abrasive wear, and inflammatory cell-induced corrosion [ICIC]). Third-body abrasive wear was evaluated using the Hood method for polyethylene components and a similar method quantifying surface damage of the femoral condyle was used. The total area damaged by ICIC was quantified using digital photogrammetry. Surface damage associated with corrosion and/or CoCr debris release was identified in 51 (98%) CoCr femoral components. Five types of damage were identified: 98% of femoral components exhibited third-body abrasive wear (mostly observed as scratching, n = 51/52), 29% of femoral components exhibited ICIC damage (n = 15/52), 41% exhibited cement interface damage (n = 11/27), 17% exhibited metal-on-metal wear after wear-through of the polyethylene insert (n = 9/52), and 50% of the modular femoral components exhibited mechanically assisted crevice corrosion taper damage (n = 2/4). The total ICIC-damaged area was an average of 0.11 ± 0.12 mm 2 (range: 0.01-0.46 mm 2 ). Although implant damage in total knee arthroplasty is typically reported with regard to the polyethylene insert, the results of this study demonstrate that abrasive and corrosive damage occurs on the CoCr femoral condyle in vivo. Copyright © 2016 Elsevier Inc. All rights reserved.

Orthopaedic management of haemophilia arthropathy of the ankle.

PubMed

Pasta, G; Forsyth, A; Merchan, C R; Mortazavi, S M J; Silva, M; Mulder, K; Mancuso, E; Perfetto, O; Heim, M; Caviglia, H; Solimeno, L

2008-07-01

Joint bleeding, or haemarthrosis, is the most common type of bleeding episode experienced by individuals with haemophilia A and B. This leads to changes within the joints, including synovial proliferation, which results in further bleeding and chronic synovitis. Blood in the joint can also directly damage the cartilage, and with repeated bleeding, there is progressive destruction of both cartilage and bone. The end result is known as haemophilic arthropathy. The joints most commonly affected are the knees, elbows and ankles, although any synovial joint may be involved. In the ankle, both the tibiotalar and subtalar joints may be affected and joint bleeding and arthropathy can lead to a number of deformities. Haemophilic arthropathy can be prevented through regular factor replacement prophylaxis and implementing physiotherapy. However, when necessary, there are multiple surgical and non-surgical options available. In early ankle arthropathy with absent or minimal joint changes, both radioisotopic and chemical synoviorthesis can be used to reduce the hypertrophied synovium. These procedures can decrease the frequency of bleeding episodes, minimizing the risk of articular cartilage damage. Achilles tendon lengthening can be performed, in isolation or in combination with other surgical measures, to correct Achilles tendon contractures. Both arthroscopic and open synovectomies are available as a means to remove the friable villous layer of the synovium and are often indicated when bleeding episodes cannot be properly controlled by factor replacement therapy or synoviorthesis. In the later stages of ankle arthropathy, other surgical options may be considered. Debridement may be indicated when there are loose pieces of cartilage or anterior osteophytes, and can help to improve the joint function, even in the presence of articular cartilage damage. Supramalleolar tibial osteotomy may be indicated in patients with a valgus deformity of the hindfoot without degenerative radiographic findings. Joint fusion, or arthrodesis, is the treatment of choice in the advanced stages of ankle arthropathy although total ankle replacement is currently available. Early ankle replacement components were associated with a poor outcome, but as implant designs have improved, there have been successful outcomes achieved. As the ankle is a commonly affected joint in many individuals with haemophilia, it is important to add to the knowledge base to validate indications and timing of surgical and non-surgical interventions in ankle arthropathy.

Joint Instability and Osteoarthritis

PubMed Central

Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

2015-01-01

Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA. PMID:25741184

Joint instability and osteoarthritis.

PubMed

Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

2015-01-01

Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA.

Using a surrogate contact pair to evaluate polyethylene wear in prosthetic knee joints.

PubMed

Sanders, Anthony P; Lockard, Carly A; Weisenburger, Joel N; Haider, Hani; Raeymaekers, Bart

2016-01-01

With recent improvements to the properties of ultra-high molecular weight polyethylene (UHMWPE) used in joint replacements, prosthetic knee and hip longevity may extend beyond two decades. However, it is difficult and costly to replicate such a long in vivo lifetime using clinically relevant in vitro wear testing approaches such as walking gait joint simulators. We advance a wear test intermediate in complexity between pin-on-disk and knee joint simulator tests. The test uses a surrogate contact pair, consisting of a surrogate femoral and tibial specimen that replicate the contact mechanics of any full-scale knee condyle contact pair. The method is implemented in a standard multi-directional pin-on-disk wear test machine, and we demonstrate its application via a two-million-cycle wear test of three different UHMWPE formulations. Further, we demonstrate the use of digital photography and image processing to accurately quantify fatigue damage based on the reduced transmission of light through a damage area in a UHMWPE specimen. The surrogate contact pairs replicate the knee condyle contact areas within -3% to +12%. The gravimetric wear test results reflect the dose of crosslinking radiation applied to the UHMWPE: 35 kGy yielded a wear rate of 7.4 mg/Mcycles, 55 kGy yielded 1.0 mg/Mcycles, and 75 kGy (applied to a 0.1% vitamin E stabilized UHMWPE) yielded 1.5 mg/Mcycles. A precursor to spalling fatigue is observed and precisely measured in the radiation-sterilized (35 kGy) and aged UHMWPE specimen. The presented techniques can be used to evaluate the high-cycle fatigue performance of arbitrary knee condyle contact pairs under design-specific contact stresses, using existing wear test machines. This makes the techniques more economical and well-suited to standardized comparative testing. © 2015 Wiley Periodicals, Inc.

Attenuation of early phase inflammation by cannabidiol prevents pain and nerve damage in rat osteoarthritis

PubMed Central

Philpott, Holly T.; O'Brien, Melissa; McDougall, Jason J.

2017-01-01

Abstract Osteoarthritis (OA) is a multifactorial joint disease, which includes joint degeneration, intermittent inflammation, and peripheral neuropathy. Cannabidiol (CBD) is a noneuphoria producing constituent of cannabis that has the potential to relieve pain. The aim of this study was to determine whether CBD is anti-nociceptive in OA, and whether inhibition of inflammation by CBD could prevent the development of OA pain and joint neuropathy. Osteoarthritis was induced in male Wistar rats (150-175 g) by intra-articular injection of sodium monoiodoacetate (MIA; 3 mg). On day 14 (end-stage OA), joint afferent mechanosensitivity was assessed using in vivo electrophysiology, whereas pain behaviour was measured by von Frey hair algesiometry and dynamic incapacitance. To investigate acute joint inflammation, blood flow and leukocyte trafficking were measured on day 1 after MIA. Joint nerve myelination was calculated by G-ratio analysis. The therapeutic and prophylactic effects of peripheral CBD (100-300 μg) were assessed. In end-stage OA, CBD dose-dependently decreased joint afferent firing rate, and increased withdrawal threshold and weight bearing (P < 0.0001; n = 8). Acute, transient joint inflammation was reduced by local CBD treatment (P < 0.0001; n = 6). Prophylactic administration of CBD prevented the development of MIA-induced joint pain at later time points (P < 0.0001; n = 8), and was also found to be neuroprotective (P < 0.05; n = 6-8). The data presented here indicate that local administration of CBD blocked OA pain. Prophylactic CBD treatment prevented the later development of pain and nerve damage in these OA joints. These findings suggest that CBD may be a safe, useful therapeutic for treating OA joint neuropathic pain. PMID:28885454

Attenuation of early phase inflammation by cannabidiol prevents pain and nerve damage in rat osteoarthritis.

PubMed

Philpott, Holly T; OʼBrien, Melissa; McDougall, Jason J

2017-12-01

Osteoarthritis (OA) is a multifactorial joint disease, which includes joint degeneration, intermittent inflammation, and peripheral neuropathy. Cannabidiol (CBD) is a noneuphoria producing constituent of cannabis that has the potential to relieve pain. The aim of this study was to determine whether CBD is anti-nociceptive in OA, and whether inhibition of inflammation by CBD could prevent the development of OA pain and joint neuropathy. Osteoarthritis was induced in male Wistar rats (150-175 g) by intra-articular injection of sodium monoiodoacetate (MIA; 3 mg). On day 14 (end-stage OA), joint afferent mechanosensitivity was assessed using in vivo electrophysiology, whereas pain behaviour was measured by von Frey hair algesiometry and dynamic incapacitance. To investigate acute joint inflammation, blood flow and leukocyte trafficking were measured on day 1 after MIA. Joint nerve myelination was calculated by G-ratio analysis. The therapeutic and prophylactic effects of peripheral CBD (100-300 μg) were assessed. In end-stage OA, CBD dose-dependently decreased joint afferent firing rate, and increased withdrawal threshold and weight bearing (P < 0.0001; n = 8). Acute, transient joint inflammation was reduced by local CBD treatment (P < 0.0001; n = 6). Prophylactic administration of CBD prevented the development of MIA-induced joint pain at later time points (P < 0.0001; n = 8), and was also found to be neuroprotective (P < 0.05; n = 6-8). The data presented here indicate that local administration of CBD blocked OA pain. Prophylactic CBD treatment prevented the later development of pain and nerve damage in these OA joints. These findings suggest that CBD may be a safe, useful therapeutic for treating OA joint neuropathic pain.

15 CFR 990.14 - Coordination.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OIL POLLUTION ACT REGULATIONS NATURAL RESOURCE... restoration is achieved without double recovery of damages. For joint assessments, trustees must designate one... there is no double recovery of damages. (3) Trustees may develop pre-incident or incident-specific...

Analysis Concerning the Inspection Threshold for Multi-Site Damage.

DOT National Transportation Integrated Search

1993-12-01

Periodic inspections, at a prescribed interval, for Multi-Site Damage (MS) in longitudinal fuselage lap-joints start when the aircraft has accumulated a certain number of flights, the inspection threshold. The work reported here was an attempt to obt...

Fatigue crack damage detection using subharmonic component with nonlinear boundary condition

NASA Astrophysics Data System (ADS)

Wu, Weiliang; Shen, Yanfeng; Qu, Wenzhong; Xiao, Li; Giurgiutiu, Victor

2015-03-01

In recent years, researchers have focused on structural health monitoring (SHM) and damage detection techniques using nonlinear vibration and nonlinear ultrasonic methods. Fatigue cracks may exhibit contact acoustic nonlinearity (CAN) with distinctive features such as superharmonics and subharmonics in the power spectrum of the sensing signals. However, challenges have been noticed in the practical applications of the harmonic methods. For instance, superharmonics can also be generated by the piezoelectric transducers and the electronic equipment; super/subharmonics may also stem from the nonlinear boundary conditions such as structural fixtures and joints. It is hard to tell whether the nonlinear features come from the structural damage or the intrinsic nonlinear boundary conditions. The objective of this paper is to demonstrate the application of nonlinear ultrasonic subharmonic method for detecting fatigue cracks with nonlinear boundary conditions. The fatigue crack was qualitatively modeled as a single-degree-of-freedom (SDOF) system with non-classical hysteretic nonlinear interface forces at both sides of the crack surfaces. The threshold of subharmonic generation was studied, and the influence of crack interface parameters on the subharmonic resonance condition was investigated. The different threshold behaviors between the nonlinear boundary condition and the fatigue crack was found, which can be used to distinguish the source of nonlinear subharmonic features. To evaluate the proposed method, experiments of an aluminum plate with a fatigue crack were conducted to quantitatively verify the subharmonic resonance range. Two surface-bonded piezoelectric transducers were used to generate and receive ultrasonic wave signals. The fatigue damage was characterized in terms of a subharmonic damage index. The experimental results demonstrated that the subharmonic component of the sensing signal can be used to detect the fatigue crack and further distinguish it from inherent nonlinear boundary conditions.

Fatigue crack damage detection using subharmonic component with nonlinear boundary condition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Weiliang, E-mail: wwl@whu.edu.cn; Qu, Wenzhong, E-mail: qwz@whu.edu.cn, E-mail: xiaoli6401@126.com; Xiao, Li, E-mail: qwz@whu.edu.cn, E-mail: xiaoli6401@126.com

In recent years, researchers have focused on structural health monitoring (SHM) and damage detection techniques using nonlinear vibration and nonlinear ultrasonic methods. Fatigue cracks may exhibit contact acoustic nonlinearity (CAN) with distinctive features such as superharmonics and subharmonics in the power spectrum of the sensing signals. However, challenges have been noticed in the practical applications of the harmonic methods. For instance, superharmonics can also be generated by the piezoelectric transducers and the electronic equipment; super/subharmonics may also stem from the nonlinear boundary conditions such as structural fixtures and joints. It is hard to tell whether the nonlinear features come frommore » the structural damage or the intrinsic nonlinear boundary conditions. The objective of this paper is to demonstrate the application of nonlinear ultrasonic subharmonic method for detecting fatigue cracks with nonlinear boundary conditions. The fatigue crack was qualitatively modeled as a single-degree-of-freedom (SDOF) system with non-classical hysteretic nonlinear interface forces at both sides of the crack surfaces. The threshold of subharmonic generation was studied, and the influence of crack interface parameters on the subharmonic resonance condition was investigated. The different threshold behaviors between the nonlinear boundary condition and the fatigue crack was found, which can be used to distinguish the source of nonlinear subharmonic features. To evaluate the proposed method, experiments of an aluminum plate with a fatigue crack were conducted to quantitatively verify the subharmonic resonance range. Two surface-bonded piezoelectric transducers were used to generate and receive ultrasonic wave signals. The fatigue damage was characterized in terms of a subharmonic damage index. The experimental results demonstrated that the subharmonic component of the sensing signal can be used to detect the fatigue crack and further distinguish it from inherent nonlinear boundary conditions.« less

Effects of radiofrequency probe application on irrigation fluid temperature in the wrist joint.

PubMed

Sotereanos, Dean G; Darlis, Nickolaos A; Kokkalis, Zinon T; Zanaros, George; Altman, Gregory T; Miller, Mark Carl

2009-12-01

Radiofrequency (RF) probes used in wrist arthroscopy may raise joint fluid temperature, increasing the risk of capsular and ligamentous damage. The purposes of the current study were to measure joint fluid temperature during wrist arthroscopy with the use of RF probes, and to determine whether using an outlet portal will reduce the maximum temperature. We performed wrist arthroscopy on 8 cadaveric arms. Ablation and coagulation cycles using RF probe were performed at documented locations within the joint. This was done for 60-second intervals on both the radial and ulnar side of the wrist, to mimic clinical practice. We used 4 fiberoptic phosphorescent probes to measure temperature (radial, ulnar, inflow-tube, and outflow-tube probes) and measured joint fluid temperature with and without outflow. There was a significant difference between wrists with and without outflow when examining maximum ablation temperatures (p < .002). All specimens showed higher maximum and average ablation temperatures without outflow. Maximum joint temperatures, greater than 60 degrees C, were observed in only no-outflow conditions. In performing RF ablation during wrist arthroscopy, the use of an outlet portal reduces the joint fluid temperature. Without an outlet portal, maximum temperatures can exceed desirable levels when using ablation; such temperatures have the potential to damage adjacent tissues. It is useful to maintain adequate outflow when using the radiofrequency probes during wrist arthroscopy.

Numerical Investigation of T-joints with 3D Four Directional Braided Composite Fillers Under Tensile Loading

NASA Astrophysics Data System (ADS)

Li, Xiao-kang; Liu, Zhen-guo; Hu, Long; Wang, Yi-bo; Lei, Bing; Huang, Xiang

2017-02-01

Numerical studied on T-joints with three-dimensional four directional (3D4D) braided composite fillers was presented in this article. Compared with conventional unidirectional prepreg fillers, the 3D braided composite fillers have excellent ability to prevent crack from penetrating trigone fillers, which constantly occurred in the conventional fillers. Meanwhile, the 3D braided composite fillers had higher fiber volume fraction and eliminated the fiber folding problem in unidirectional prepreg fillers. The braiding technology and mechanical performance of 3D4D braided fillers were studied. The numerical model of carbon fiber T-joints with 3D4D braided composite fillers was built by finite element analysis software. The damage formation, extension and failing process of T-joints with 3D4D braided fillers under tensile load were investigated. Further investigation was extended to the effect of 3D4D braided fillers with different braiding angles on mechanical behavior of the T-joints. The study results revealed that the filling area was the weakest part of the T-joints where the damage first appeared and the crack then rapidly spread to the glue film around the filling area and the interface between over-laminate and soleplate. The 3D4D braided fillers were undamaged and the braiding angle change induced a little effect on the bearing capacity of T-joints.

Double-button Fixation System for Management of Acute Acromioclavicular Joint Dislocation

PubMed Central

Torkaman, Ali; Bagherifard, Abolfazl; Mokhatri, Tahmineh; Haghighi, Mohammad Hossein Shabanpour; Monshizadeh, Siamak; Taraz, Hamid; Hasanvand, Amin

2016-01-01

Background: Surgical treatments for acromioclavicular (AC) joint dislocation present with some complications. The present study was designed to evaluate the double-button fixation system in the management of acute acromioclavicular joint dislocation. Methods: This cross sectional study, done between February 2011 to June 2014, consisted of 28 patients who underwent surgical management by the double-button fixation system for acute AC joint dislocation. Age, sex, injury mechanism, dominant hand, side with injury, length of follow up, time before surgery, shoulder and hand (DASH), constant and visual analogue scale (VAS) scores, and all complications of the cases during the follow up were recorded. Results: The mean age of patients was 33.23±6.7 years. Twenty four patients (85.71%) were male and four (14.28%) were female. The significant differences were observed between pre-operation VAS, constant shoulder scores and post-operation measurements. There were not any significant differences between right and left coracoclavicular, but two cases of heterotrophic ossifications were recorded. The mean follow-up time was 16.17±4.38 months. Conclusion: According to the results, the double-button fixation system for management of acute acromioclavicular joint dislocation has suitable results and minimal damage to the soft tissues surrounding the coracoclavicular ligaments. PMID:26894217

Treatment of TMJDS with helium-neon laser beam irradiation on the acupoints

NASA Astrophysics Data System (ADS)

Li, Ping

1993-03-01

Through He-NE laser stimulation of acupuncture points, we treated and observed 50 cases of Temporomandibular Joint Dysfunction Syndrome (TMJDS). The results proved that this treatment was very effective for relieving the patient's pain. In cases which had structural disturbances and organic damage such as limitation of mouth-opening and joint clink, there was less improvement of symptoms and no relief for joint clink.

Plating To Reinforce Welded Joints

NASA Technical Reports Server (NTRS)

Otousa, J. E.

1982-01-01

Electrodeposition used to strengthen welded joints gouged, nicked, or suffered other mechanical damage. Plating cell, typically of acrylic plastic such as poly (Methylmetacrylate), is assembled around part to be plated. Areas not to be plated are masked with plater's tape. Weld area is plated in standard nickel-plating process.

[Sacroiliac joint disorders in Abidjan: epidemiological, clinical, radiological and etiological characteristics].

PubMed

Diomandé, Mohamed; Eti, E; Ouattara, B; Cheteu, K E; Kouakou Ehaulier Soh, C L; Gbané-Koné, M; Djaha Kouassi, Jean-Mermoze; Kouakou N'zué, M

2014-10-01

The sacroiliac joint remains unknown in sub-Saharan Africa. Studies about the sacroiliac diseases are rare Aim : Describe the epidemiological, clinical, radiological and etiological characteristics of sacroiliac joint diseases in Abidjan Methods : Retrospective and descriptive study concerning 17 patients hospitalized from February 2003 to April 2010 in the department of rheumatology of university hospital center of Cocody (Abidjan) for buttock pain or others functional signs evoking sacroiliac joint which were attested by radiographic lesions. We were interested on the epidemiological, clinical and radiological characteristics and the etiologies in the sacroiliac disease. The hospital prevalence of sacroiliac diseases was 0.55% corresponding in 17 of 3067 rheumatological diseases. The female sex predominated (82.35%) and the mean age of 25.58 years. Gyneco-obstetric events were the predominant risk factors (47.05%). Sacroiliac damage was manifested by inflammatory pain (64.7%) localized at the buttock or lumbar spine, radiating to the thigh (52.9%) and was accompanied by functional disability (82.2%) and fever was not present every time (64.7%). The physical findings were the tripod sign positive (58.8%), the monopodal backing positive (41.2%) and palpation painful of sacroiliac joint. The standard radiograph revealed a blurring aspect and widening of joint space associated with demineralization (68.4%), a joint space narrowing and erosion of articular banks (23.5%). The etiologies found were bacterial arthritis (82.3%) mainly pyogenic (70.58%), osteoarthritis (11.7%) and ankylosing spondylitis (5.9%). Sacroiliac joint diseases are rare in rheumatology practice in Abidjan, concern younger subjects and are dominated by pyogenic sacroiliitis.

Association of Baseline Knee Sagittal Dynamic Joint Stiffness during Gait and 2-year Patellofemoral Cartilage Damage Worsening in Knee Osteoarthritis

PubMed Central

Chang, Alison H.; Chmiel, Joan S.; Almagor, Orit; Guermazi, Ali; Prasad, Pottumarthi V.; Moisio, Kirsten C.; Belisle, Laura; Zhang, Yunhui; Hayes, Karen; Sharma, Leena

2016-01-01

Objective Knee sagittal dynamic joint stiffness (DJS) describes the biomechanical interaction between change in external knee flexion moment and flexion angular excursion during gait. In theory, greater DJS may particularly stress the patellofemoral (PF) compartment and thereby contribute to PF osteoarthritis (OA) worsening. We hypothesized that greater baseline knee sagittal DJS is associated with PF cartilage damage worsening 2 years later. Methods Participants all had OA in at least one knee. Knee kinematics and kinetics during gait were recorded using motion capture systems and force plates. Knee sagittal DJS was computed as the slope of the linear regression line for knee flexion moments vs. angles during the loading response phase. Knee MRI scans were obtained at baseline and 2 years later. We assessed the association between baseline DJS and baseline-to-2-year PF cartilage damage worsening using logistic regression with generalized estimating equations. Results Our sample had 391 knees (204 persons): mean age 64.2 years (SD 10.0); BMI 28.4 kg/m2 (5.7); 76.5% women. Baseline knee sagittal DJS was associated with baseline-to-2-year cartilage damage worsening in the lateral (OR=5.35, 95% CI: 2.37–12.05) and any PF (OR=2.99, 95% CI: 1.27–7.04) compartment. Individual components of baseline DJS (i.e., change in knee moment or angle) were not associated with subsequent PF disease worsening. Conclusion Capturing the concomitant effect of knee kinetics and kinematics during gait, knee sagittal DJS is a potentially modifiable risk factor for PF disease worsening. PMID:27729289

Controlled, cross-sectional MRI evaluation of joint status in severe haemophilia A patients treated with prophylaxis vs. on demand

PubMed Central

Oldenburg, J; Zimmermann, R; Katsarou, O; Theodossiades, G; Zanon, E; Niemann, B; Kellermann, E; Lundin, B

2015-01-01

In patients with haemophilia A, factor VIII (FVIII) prophylaxis reduces bleeding frequency and joint damage compared with on-demand therapy. To assess the effect of prophylaxis initiation age, magnetic resonance imaging (MRI) was used to evaluate bone and cartilage damage in patients with severe haemophilia A. In this cross-sectional, multinational investigation, patients aged 12–35 years were assigned to 1 of 5 groups: primary prophylaxis started at age <2 years (group 1); secondary prophylaxis started at age 2 to <6 years (group 2), 6 to <12 years (group 3), or 12−18 years (group 4); or on-demand treatment (group 5). Joint status at ankles and knees was assessed using Compatible Additive MRI scoring (maximum and mean ankle; maximum and mean of all 4 joints) and Gilbert scores in the per-protocol population (n = 118). All prophylaxis groups had better MRI joint scores than the on-demand group. MRI scores generally increased with current patient age and later start of prophylaxis. Ankles were the most affected joints. In group 1 patients currently aged 27−35 years, the median of maximum ankle scores was 0.0; corresponding values in groups 4 and 5 were 17.0 and 18.0, respectively [medians of mean index joint scores: 0.0 (group 1), 8.1 (group 2) and 13.8 (group 4)]. Gilbert scores revealed outcomes less pronounced than MRI scores. MRI scores identified pathologic joint status with high sensitivity. Prophylaxis groups had lower annualized joint bleeds and MRI scores vs. the on-demand group. Primary prophylaxis demonstrated protective effects against joint deterioration compared with secondary prophylaxis. PMID:25470205

Distribution and nature of fault architecture in a layered sandstone and shale sequence: An example from the Moab fault, Utah

USGS Publications Warehouse

Davatzes, N.C.; Aydin, A.

2005-01-01

We examined the distribution of fault rock and damage zone structures in sandstone and shale along the Moab fault, a basin-scale normal fault with nearly 1 km (0.62 mi) of throw, in southeast Utah. We find that fault rock and damage zone structures vary along strike and dip. Variations are related to changes in fault geometry, faulted slip, lithology, and the mechanism of faulting. In sandstone, we differentiated two structural assemblages: (1) deformation bands, zones of deformation bands, and polished slip surfaces and (2) joints, sheared joints, and breccia. These structural assemblages result from the deformation band-based mechanism and the joint-based mechanism, respectively. Along the Moab fault, where both types of structures are present, joint-based deformation is always younger. Where shale is juxtaposed against the fault, a third faulting mechanism, smearing of shale by ductile deformation and associated shale fault rocks, occurs. Based on the knowledge of these three mechanisms, we projected the distribution of their structural products in three dimensions along idealized fault surfaces and evaluated the potential effect on fluid and hydrocarbon flow. We contend that these mechanisms could be used to facilitate predictions of fault and damage zone structures and their permeability from limited data sets. Copyright ?? 2005 by The American Association of Petroleum Geologists.

Ankle rehabilitation device with two degrees of freedom and compliant joint

NASA Astrophysics Data System (ADS)

Racu (Cazacu, C.-M.; Doroftei, I.

2015-11-01

We propose a rehabilitation device that we intend to be low cost and easy to manufacture. The system will ensure functionality but also have a small dimensions and low mass, considering the physiological dimensions of the foot and lower leg. To avoid injure of the ankle joint, this device is equipped with a compliant joint between the motor and mechanical transmission. The torque of this joint is intended to be adjustable, according to the degree of ankle joint damage. To choose the material and the dimensions of this compliant joint, in this paper we perform the first stress simulation. The minimum torque is calculated, while the maximum torque is given by the preliminary chosen actuator.

Pushover analysis of reinforced concrete frames considering shear failure at beam-column joints

NASA Astrophysics Data System (ADS)

Sung, Y. C.; Lin, T. K.; Hsiao, C. C.; Lai, M. C.

2013-09-01

Since most current seismic capacity evaluations of reinforced concrete (RC) frame structures are implemented by either static pushover analysis (PA) or dynamic time history analysis, with diverse settings of the plastic hinges (PHs) on such main structural components as columns, beams and walls, the complex behavior of shear failure at beam-column joints (BCJs) during major earthquakes is commonly neglected. This study proposes new nonlinear PA procedures that consider shear failure at BCJs and seek to assess the actual damage to RC structures. Based on the specifications of FEMA-356, a simplified joint model composed of two nonlinear cross struts placed diagonally over the location of the plastic hinge is established, allowing a sophisticated PA to be performed. To verify the validity of this method, the analytical results for the capacity curves and the failure mechanism derived from three different full-size RC frames are compared with the experimental measurements. By considering shear failure at BCJs, the proposed nonlinear analytical procedures can be used to estimate the structural behavior of RC frames, including seismic capacity and the progressive failure sequence of joints, in a precise and effective manner.

Effects of Welding Parameters on Mechanical Properties in Electron Beam Welded CuCrZr Alloy Plates

NASA Astrophysics Data System (ADS)

Jaypuria, Sanjib; Doshi, Nirav; Pratihar, Dilip Kumar

2018-03-01

CuCrZr alloys are attractive structural materials for plasma-facing components (PFC) and heat sink element in the International Thermonuclear Experimental Reactor (ITER) fusion reactors. This material has gained so much attention because of its high thermal conductivity and fracture toughness, high resistance to radiation damage and stability at elevated temperatures. The objective of this work is to study the effects of electron beam welding parameters on the mechanical strength of the butt welded CuCrZr joint. Taguchi method is used as the design of experiments to optimize the input parameters, such as accelerating voltage, beam current, welding speed, oscillation amplitude and frequency. The joint strength and ductility are the desired responses, which are measured through ultimate tensile strength and percent elongation, respectively. Accelerating voltage and welding speed are found to have significant influence on the strength. A combination of low amplitude and high-frequency oscillation is suggested for the higher joint strength and ductility. There is a close agreement between Taguchi predicted results and experimental ones. Fractographic analysis of joint and weld zone analysis are carried out to study the failure behaviour and microstructural variation in the weld zone, respectively.

The characterization of widespread fatigue damage in fuselage structure

NASA Technical Reports Server (NTRS)

Piascik, Robert S.; Willard, Scott A.; Miller, Matthew

1994-01-01

The characteristics of widespread fatigue damage (WSFD) in fuselage riveted structure were established by detailed nondestructive and destructive examinations of fatigue damage contained in a full size fuselage test article. The objectives of this were to establish an experimental data base for validating emerging WSFD analytical prediction methodology and to identify first order effects that contribute to fatigue crack initiation and growth. Detailed examinations were performed on a test panel containing four bays of a riveted lap splice joint. The panel was removed from a full scale fuselage test article after receiving 60,000 full pressurization cycles. The results of in situ examinations document the progression of fuselage skin fatigue crack growth through crack linkup. Detailed tear down examinations and fractography of the lap splice joint region revealed fatigue crack initiation sites, crack morphology, and crack linkup geometry. From this large data base, distributions of crack size and locations are presented and discussions of operative damage mechanisms are offered.

The characterization of widespread fatigue damage in fuselage structure

NASA Technical Reports Server (NTRS)

Piascik, Robert S.; Willard, Scott A.; Miller, Matthew

1994-01-01

The characteristics of widespread fatigue damage (WSFD) in fuselage riveted structure were established by detailed nondestructive and destructive examinations of fatigue damage contained in a full size fuselage test article. The objectives of this work were to establish an experimental data base for validating emerging WSFD analytical prediction methodology and to identify first order effects that contribute to fatigue crack initiation and growth. Detailed examinations were performed on a test panel containing four bays of a riveted lap splice joint. The panel was removed from a full scale fuselage test article after receiving 60,000 full pressurization cycles. The results of in situ examinations document the progression of fuselage skin fatigue crack growth through crack linkup. Detailed tear down examinations and fractography of the lap splice joint region revealed fatigue crack initiation sites, crack morphology and crack linkup geometry. From this large data base, distributions of crack size and locations are presented and discussions of operative damage mechanisms are offered.

Clinical characteristics of RA patients with secondary SS and association with joint damage.

PubMed

Brown, Lindsay E; Frits, Michelle L; Iannaccone, Christine K; Weinblatt, Michael E; Shadick, Nancy A; Liao, Katherine P

2015-05-01

Secondary SS (sSS) is a common extra-articular manifestation of RA. There are conflicting data regarding the association of sSS with worse joint damage. This study aims to characterize sSS patients in an RA cohort and study the association between sSS and joint damage. We conducted a cross-sectional study of RA patients with ≥1 year of follow-up at a large academic centre. Subjects with co-morbid diseases that can also result in sicca symptoms were excluded from the analysis. Subjects were considered to have sSS if they were reported as having sSS by their rheumatologist at recruitment into the cohort and had the diagnosis confirmed by chart review. The primary outcome was Sharp score using bilateral hand radiographs at recruitment. We constructed a linear regression model to determine the association of sSS status and Sharp score adjusted by age, gender, disease duration and ACPA and RF status. We studied 829 RA subjects, mean age 57 years, 83% female, mean RA duration 13 years, 74% seropositive; 85 subjects (10.3%) had sSS. We observed a female predominance (95.3%), longer mean disease duration (16.9 years) and higher frequency of RF or ACPA positive among patients with sSS and RA. Having sSS at baseline was associated with higher Sharp scores (P = 0.03), independent of age, gender, RA disease duration and seropositive disease. In our RA cohort, RA subjects with sSS had worse joint damage, suggesting that sSS is a marker of more aggressive disease. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

20 CFR 10.712 - How much of any settlement or judgment must be paid to the United States?

Code of Federal Regulations, 2014 CFR

2014-04-01

... entire amount of the award; (ii) Subtract the amount of award representing damage to real or personal... Damage $0.00 (iii) Subtotal A (Line a minus Line b) $100,000.00 (iv) Amount Allocated for Loss of... which is permitted under the state law and for damage to her vehicle (documented at $50,000.00). A joint...

20 CFR 10.712 - How much of any settlement or judgment must be paid to the United States?

Code of Federal Regulations, 2013 CFR

2013-04-01

... entire amount of the award; (ii) Subtract the amount of award representing damage to real or personal... Damage $0.00 (iii) Subtotal A (Line a minus Line b) $100,000.00 (iv) Amount Allocated for Loss of... which is permitted under the state law and for damage to her vehicle (documented at $50,000.00). A joint...

20 CFR 10.712 - How much of any settlement or judgment must be paid to the United States?

Code of Federal Regulations, 2012 CFR

2012-04-01

... entire amount of the award; (ii) Subtract the amount of award representing damage to real or personal... Damage $0.00 (iii) Subtotal A (Line a minus Line b) $100,000.00 (iv) Amount Allocated for Loss of... which is permitted under the state law and for damage to her vehicle (documented at $50,000.00). A joint...

Screening Adhesively Bonded Single-Lap-Joint Testing Results Using Nonlinear Calculation Parameters

DTIC Science & Technology

2012-03-01

versus displacement response for single-lap-joints bonded with damage-tolerant adhe- sives, such the polyurea adhesive plotted in Figure 2, is much...displacement response for a single-lap-joint bonded with a polyurea adhesive. Complex x-y plots are commonly fitted using the Levenberg-Marquardt...expected decrease in maximum strength for the polyurea in compar- ison to the epoxy, which could have been obtained using a traditional analysis approach

Osteoarthritis screening using Raman spectroscopy of dried human synovial fluid drops

NASA Astrophysics Data System (ADS)

Esmonde-White, Karen A.; Mandair, Gurjit S.; Esmonde-White, Francis W. L.; Raaii, Farhang; Roessler, Blake J.; Morris, Michael D.

2009-02-01

We describe the use of Raman spectroscopy to investigate synovial fluid drops deposited onto fused silica microscope slides. This spectral information can be used to identify chemical changes in synovial fluid associated with osteoarthritis (OA) damage to knee joints. The chemical composition of synovial fluid is predominately proteins (enzymes, cytokines, or collagen fragments), glycosaminoglycans, and a mixture of minor components such as inorganic phosphate crystals. During osteoarthritis, the chemical, viscoelastic and biological properties of synovial fluid are altered. A pilot study was conducted to determine if Raman spectra of synovial fluid correlated with radiological scoring of knee joint damage. After informed consent, synovial fluid was drawn and x-rays were collected from the knee joints of 40 patients. Raman spectra and microscope images were obtained from the dried synovial fluid drops using a Raman microprobe and indicate a coarse separation of synovial fluid components. Individual protein signatures could not be identified; Raman spectra were useful as a general marker of overall protein content and secondary structure. Band intensity ratios used to describe protein and glycosaminoglycan structure were used in synovial fluid spectra. Band intensity ratios of Raman spectra indicate that there is less ordered protein secondary structure in synovial fluid from the damage group. Combination of drop deposition with Raman spectroscopy is a powerful approach to examining synovial fluid for the purposes of assessing osteoarthritis damage.

Behnken during EVA 4 - Expedition 16 / STS-13 Joint Operations

NASA Image and Video Library

2008-03-21

S123-E-007816 (21 March 2008) --- Astronaut Robert L. Behnken, STS-123 mission specialist, participates in the mission's fourth scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the 6-hour, 24-minute spacewalk, Behnken and astronaut Mike Foreman (out of frame), mission specialist, replaced a failed Remote Power Control Module -- essentially a circuit breaker -- on the station's truss. The spacewalkers also tested a repair method for damaged heat resistant tiles on the space shuttle. This technique used a caulk-gun-like tool named the Tile Repair Ablator Dispenser to dispense a material called Shuttle Tile Ablator-54 into purposely damaged heat shield tiles. The sample tiles will be returned to Earth to undergo extensive testing on the ground.

Foreman during EVA 4 - Expedition 16 / STS-13 Joint Operations

NASA Image and Video Library

2008-03-21

S123-E-007832 (21 March 2008) --- Astronaut Mike Foreman, STS-123 mission specialist, participates in the mission's fourth scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the 6-hour, 24-minute spacewalk, Foreman and astronaut Robert L. Behnken (out of frame), mission specialist, replaced a failed Remote Power Control Module -- essentially a circuit breaker -- on the station's truss. The spacewalkers also tested a repair method for damaged heat resistant tiles on the space shuttle. This technique used a caulk-gun-like tool named the Tile Repair Ablator Dispenser to dispense a material called Shuttle Tile Ablator-54 into purposely damaged heat shield tiles. The sample tiles will be returned to Earth to undergo extensive testing on the ground.

Behnken during EVA 4 - Expedition 16 / STS-13 Joint Operations

NASA Image and Video Library

2008-03-21

S123-E-007907 (21 March 2008) --- Astronaut Robert L. Behnken, STS-123 mission specialist, participates in the mission's fourth scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the 6-hour, 24-minute spacewalk, Behnken and astronaut Mike Foreman (out of frame), mission specialist, replaced a failed Remote Power Control Module -- essentially a circuit breaker -- on the station's truss. The spacewalkers also tested a repair method for damaged heat resistant tiles on the space shuttle. This technique used a caulk-gun-like tool named the Tile Repair Ablator Dispenser to dispense a material called Shuttle Tile Ablator-54 into purposely damaged heat shield tiles. The sample tiles will be returned to Earth to undergo extensive testing on the ground.

Behnken and Foreman during EVA 4 - Expedition 16 / STS-13 Joint Operations

NASA Image and Video Library

2008-03-21

S123-E-007838 (21 March 2008) --- Astronauts Robert L. Behnken (top) and Mike Foreman, both STS-123 mission specialists, participate in the mission's fourth scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the 6-hour, 24-minute spacewalk, Behnken and Foreman replaced a failed Remote Power Control Module -- essentially a circuit breaker -- on the station's truss. The spacewalkers also tested a repair method for damaged heat resistant tiles on the space shuttle. This technique used a caulk-gun-like tool named the Tile Repair Ablator Dispenser to dispense a material called Shuttle Tile Ablator-54 into purposely damaged heat shield tiles. The sample tiles will be returned to Earth to undergo extensive testing on the ground.

Behnken during EVA 4 - Expedition 16 / STS-13 Joint Operations

NASA Image and Video Library

2008-03-21

S123-E-007906 (21 March 2008) --- Astronaut Robert L. Behnken, STS-123 mission specialist, participates in the mission's fourth scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the 6-hour, 24-minute spacewalk, Behnken and astronaut Mike Foreman (out of frame), mission specialist, replaced a failed Remote Power Control Module -- essentially a circuit breaker -- on the station's truss. The spacewalkers also tested a repair method for damaged heat resistant tiles on the space shuttle. This technique used a caulk-gun-like tool named the Tile Repair Ablator Dispenser to dispense a material called Shuttle Tile Ablator-54 into purposely damaged heat shield tiles. The sample tiles will be returned to Earth to undergo extensive testing on the ground.

Behnken during EVA 4 - Expedition 16 / STS-13 Joint Operations

NASA Image and Video Library

2008-03-21

S123-E-007909 (21 March 2008) --- Astronaut Robert L. Behnken, STS-123 mission specialist, participates in the mission's fourth scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the 6-hour, 24-minute spacewalk, Behnken and astronaut Mike Foreman (out of frame), mission specialist, replaced a failed Remote Power Control Module -- essentially a circuit breaker -- on the station's truss. The spacewalkers also tested a repair method for damaged heat resistant tiles on the space shuttle. This technique used a caulk-gun-like tool named the Tile Repair Ablator Dispenser to dispense a material called Shuttle Tile Ablator-54 into purposely damaged heat shield tiles. The sample tiles will be returned to Earth to undergo extensive testing on the ground.

Behnken and Foreman during EVA 4 - Expedition 16 / STS-13 Joint Operations

NASA Image and Video Library

2008-03-21

S123-E-007839 (21 March 2008) --- Astronauts Mike Foreman (foreground) and Robert L. Behnken, both STS-123 mission specialists, participate in the mission's fourth scheduled session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the 6-hour, 24-minute spacewalk, Foreman and Behnken replaced a failed Remote Power Control Module -- essentially a circuit breaker -- on the station's truss. The spacewalkers also tested a repair method for damaged heat resistant tiles on the space shuttle. This technique used a caulk-gun-like tool named the Tile Repair Ablator Dispenser to dispense a material called Shuttle Tile Ablator-54 into purposely damaged heat shield tiles. The sample tiles will be returned to Earth to undergo extensive testing on the ground.

Progression of cartilage damage and meniscal pathology over 30 months is associated with an increase in radiographic tibiofemoral joint space narrowing in persons with knee OA--the MOST study.

PubMed

Crema, M D; Nevitt, M C; Guermazi, A; Felson, D T; Wang, K; Lynch, J A; Marra, M D; Torner, J; Lewis, C E; Roemer, F W

2014-10-01

To determine the association of MRI-assessed worsening of tibiofemoral cartilage damage, meniscal damage, meniscal extrusion, separately and together, with progression of radiographic joint space narrowing (JSN). The Multicenter Osteoarthitis Study (MOST) Study is a cohort study of subjects with or at risk for knee osteoarthritis (OA). Knees with radiographic OA Kellgren-Lawrence grade 2 at baseline and with baseline and 30-month 1.0 T MRIs were selected for reading using the WORMS system for cartilage damage, meniscal damage, and meniscal extrusion. The association of worsening of cartilage damage, meniscal damage, and/or meniscal extrusion with increases in the JSN was performed using logistic regression. A total of 276 knees (one per subject) were included (women 68.5%, mean age 62.9 ± 7.8, mean body mass index (BMI) 30.2 ± 5.0). Worsening of each MRI feature was associated with any increase in JSN (P < 0.01). Worsening of cartilage damage was more frequently observed than worsening of meniscal damage and extrusion, and was significantly associated with both slow and fast progression of JSN. An increasing risk of JSN worsening was associated with increasing number of worsening MRI features (P for trend < 0.0001). Worsening of tibiofemoral cartilage damage, meniscal damage, and meniscal extrusion are independent predictors of JSN progression in the same compartment. Worsening of cartilage damage is more frequently observed in JSN when compared to meniscal worsening. A strong cumulative effect on JSN progression is observed for worsening of more than one MRI feature. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

The detrimental effects of iron on the joint: a comparison between haemochromatosis and haemophilia.

PubMed

van Vulpen, Lize F D; Roosendaal, Goris; van Asbeck, B Sweder; Mastbergen, Simon C; Lafeber, Floris P J G; Schutgens, Roger E G

2015-08-01

Joint damage due to (recurrent) joint bleeding in haemophilia causes major morbidity. Although the exact pathogenesis has not been fully elucidated, a central role for iron is hypothesised. Likewise, in hereditary haemochromatosis joint destruction is caused by iron overload. A comparison between these types of arthropathy could provide more insight in the influence of iron in inducing joint damage. A literature review was performed to compare both disorders with respect to their clinical and histological characteristics, and preclinical studies on the influence of iron on different joint components were reviewed. Similarities in the features of arthropathy in haemochromatosis and haemophilia are cartilage degeneration, subchondral bone changes with osteophyte and cyst formation, and osteoporosis. In both disorders synovial inflammation and proliferation are seen, although this is much more explicit in haemophilia. Other substantial differences are the age at onset, the occurrence of chondrocalcinosis radiographically and calcium pyrophosphate dihydrate deposition disease in haemochromatosis, and a rapid progression with joint deformity and neovascularisation in haemophilia. Preclinical studies demonstrate detrimental effects of iron to all components of the joint, resulting in synovial inflammation and hyperplasia, chondrocyte death, and impaired osteoblast function. These effects, particularly the synovial changes, are aggravated in the presence of a pro-inflammatory signal, which is prominent in haemophilic arthropathy and minimal in haemochromatosis. Additional research is needed to further specify the role of iron as a specific target in treating these types of arthropathy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

An Orthopedic Perspective. Does Running Cause Osteoarthritis?

ERIC Educational Resources Information Center

Pascale, Mark; Grana, William A.

1989-01-01

Discusses the development of osteoarthritis and whether running and other impact loading sports promote it. Although these sports do not cause arthritis in normal weight bearing limbs, they can accelerate it in damaged joints. It is important to identify people with preeexisting joint disease so they can choose nonimpact-loading aerobic exercise.…

Non-destructive testing techniques based on nonlinear methods for assessment of debonding in single lap joints

NASA Astrophysics Data System (ADS)

Scarselli, G.; Ciampa, F.; Ginzburg, D.; Meo, M.

2015-04-01

Nonlinear ultrasonic non-destructive evaluation (NDE) methods can be used for the identification of defects within adhesive bonds as they rely on the detection of nonlinear elastic features for the evaluation of the bond strength. In this paper the nonlinear content of the structural response of a single lap joint subjected to ultrasonic harmonic excitation is both numerically and experimentally evaluated to identify and characterize the defects within the bonded region. Different metallic samples with the same geometry were experimentally tested in order to characterize the debonding between two plates by using two surface bonded piezoelectric transducers in pitch-catch mode. The dynamic response of the damaged samples acquired by the single receiver sensor showed the presence of higher harmonics (2nd and 3rd) and subharmonics of the fundamental frequencies. These nonlinear elastic phenomena are clearly due to nonlinear effects induced by the poor adhesion between the two plates. A new constitutive model aimed at representing the nonlinear material response generated by the interaction of the ultrasonic waves with the adhesive joint is also presented. Such a model is implemented in an explicit FE software and uses a nonlinear user defined traction-displacement relationship implemented by means of a cohesive material user model interface. The developed model is verified for the different geometrical and material configurations. Good agreement between the experimental and numerical nonlinear response showed that this model can be used as a simple and useful tool for understanding the quality of the adhesive joint.

Quantitative histological grading methods to assess subchondral bone and synovium changes subsequent to medial meniscus transection in the rat

PubMed Central

Kloefkorn, Heidi E.; Allen, Kyle D.

2017-01-01

Aim of the Study The importance of the medial meniscus to knee health is demonstrated by studies which show meniscus injuries significantly increase the likelihood of developing osteoarthritis (OA), and knee OA can be modeled in rodents using simulated meniscus injuries. Traditionally, histological assessments of OA in these models have focused on damage to the articular cartilage; however, OA is now viewed as a disease of the entire joint as an organ system. The aim of this study was to develop quantitative histological measures of bone and synovial changes in a rat medial meniscus injury model of knee OA. Materials and Methods To initiate OA, a medial meniscus transection (MMT) and a medial collateral ligament transection (MCLT) were performed in 32 male Lewis rats (MMT group). MCLT alone served as the sham procedure in 32 additional rats (MCLT sham group). At weeks 1, 2, 4, and 6 post-surgery, histological assessment of subchondral bone and synovium was performed (n = 8 per group per time point). Results Trabecular bone area and the ossification width at the osteochondral interface increased in both the MMT and MCLT groups. Subintimal synovial cell morphology also changed in MMT and MCLT groups relative to naïve animals. Conclusions OA affects the joint as an organ system, and quantifying changes throughout an entire joint can improve our understanding of the relationship between joint destruction and painful OA symptoms following meniscus injury. PMID:27797605

Quasi-static elastography comparison of hyaline cartilage structures

NASA Astrophysics Data System (ADS)

McCredie, A. J.; Stride, E.; Saffari, N.

2009-11-01

Joint cartilage, a load bearing structure in mammals, has only limited ability for regeneration after damage. For tissue engineers to design functional constructs, better understanding of the properties of healthy tissue is required. Joint cartilage is a specialised structure of hyaline cartilage; a poroviscoelastic solid containing fibril matrix reinforcements. Healthy joint cartilage is layered, which is thought to be important for correct tissue function. However, the behaviour of each layer during loading is poorly understood. Ultrasound elastography provides access to depth-dependent information in real-time for a sample during loading. A 15 MHz focussed transducer provided details from scatterers within a small fixed region in each sample. Quasi-static loading was applied to cartilage samples while ultrasonic signals before and during compressions were recorded. Ultrasonic signals were processed to provide time-shift profiles using a sum-squared difference method and cross-correlation. Two structures of hyaline cartilage have been tested ultrasonically and mechanically to determine method suitability for monitoring internal deformation differences under load and the effect of the layers on the global mechanical material behaviour. Results show differences in both the global mechanical properties and the ultrasonically tested strain distributions between the two structures tested. It was concluded that these differences are caused primarily by the fibril orientations.

Muscle Damage following Maximal Eccentric Knee Extensions in Males and Females

PubMed Central

2016-01-01

Aim To investigate whether there is a sex difference in exercise induced muscle damage. Materials and Method Vastus Lateralis and patella tendon properties were measured in males and females using ultrasonography. During maximal voluntary eccentric knee extensions (12 reps x 6 sets), Vastus Lateralis fascicle lengthening and maximal voluntary eccentric knee extensions torque were recorded every 10° of knee joint angle (20–90°). Isometric torque, Creatine Kinase and muscle soreness were measured pre, post, 48, 96 and 168 hours post damage as markers of exercise induced muscle damage. Results Patella tendon stiffness and Vastus Lateralis fascicle lengthening were significantly higher in males compared to females (p<0.05). There was no sex difference in isometric torque loss and muscle soreness post exercise induced muscle damage (p>0.05). Creatine Kinase levels post exercise induced muscle damage were higher in males compared to females (p<0.05), and remained higher when maximal voluntary eccentric knee extension torque, relative to estimated quadriceps anatomical cross sectional area, was taken as a covariate (p<0.05). Conclusion Based on isometric torque loss, there is no sex difference in exercise induced muscle damage. The higher Creatine Kinase in males could not be explained by differences in maximal voluntary eccentric knee extension torque, Vastus Lateralis fascicle lengthening and patella tendon stiffness. Further research is required to understand the significant sex differences in Creatine Kinase levels following exercise induced muscle damage. PMID:26986066

Early detection of aging cartilage and osteoarthritis in mice and patient samples using atomic force microscopy

NASA Astrophysics Data System (ADS)

Stolz, Martin; Gottardi, Riccardo; Raiteri, Roberto; Miot, Sylvie; Martin, Ivan; Imer, Raphaël; Staufer, Urs; Raducanu, Aurelia; Düggelin, Marcel; Baschong, Werner; Daniels, A. U.; Friederich, Niklaus F.; Aszodi, Attila; Aebi, Ueli

2009-03-01

The pathological changes in osteoarthritis-a degenerative joint disease prevalent among older people-start at the molecular scale and spread to the higher levels of the architecture of articular cartilage to cause progressive and irreversible structural and functional damage. At present, there are no treatments to cure or attenuate the degradation of cartilage. Early detection and the ability to monitor the progression of osteoarthritis are therefore important for developing effective therapies. Here, we show that indentation-type atomic force microscopy can monitor age-related morphological and biomechanical changes in the hips of normal and osteoarthritic mice. Early damage in the cartilage of osteoarthritic patients undergoing hip or knee replacements could similarly be detected using this method. Changes due to aging and osteoarthritis are clearly depicted at the nanometre scale well before morphological changes can be observed using current diagnostic methods. Indentation-type atomic force microscopy may potentially be developed into a minimally invasive arthroscopic tool to diagnose the early onset of osteoarthritis in situ.

Comparison of 2 fluid ingress/egress systems for canine stifle arthroscopy using computed tomography.

PubMed

Warnock, Jennifer J; Nemanic, Sarah; O'Donnell, Matthew D; Wiest, Jason E

2014-11-01

To evaluate volume of extra-articular fluid egress and complications associated with 2 fluid ingress/egress techniques for stifle arthroscopy. Ex vivo study. Canine cadavers (n = 14). Four cadavers (8 stifles) were used to validate 3D computed tomographic (CT) methods to quantify stifle joint intra- and extra-articular volumes of iodinated contrast medium. Ten canine cadavers (20 stifles) had preoperative CT, followed by stifle arthroscopy using a 10% solution of iodinated contrast enhanced ingress fluid delivered by pressure bag (2PB) or by arthroscopic peristaltic pump (3FP). All 3FP limbs had an additional fluid egress portal placed by cannula and obturator. Arthroscopy was limited to 20 minutes/joint. The volume of the contrast medium egress into the soft tissues was measured on postoperative 3D CT reconstructed images. Mean percentage of total ingress fluids administered that remained in the joint and extra-articular tissues postoperatively was 8.8 ± 1.2% in 3FP and 33.2 ± 8% in 2PB (P = .014). Two 3FP joints had 4-5 mm egress obturator tracks on the proximal medial trochlear ridge. Two 2PB joints had severe joint collapse from extracapsular fluid precluding further examination. Intermittent visual blurring by joint fluid mixing or fat pad fragmentation/dissolution was noted in 2PB joints. A superior technique was not identified: 2PB had greater egress fluid tissue accumulation, whereas 3FP had better viewing of intra-articular structures with less tissue egress fluid accumulation; however, cartilage damage was induced with the egress obturator. © Copyright 2014 by The American College of Veterinary Surgeons.

Damage tolerance of bonded composite aircraft repairs for metallic structures

NASA Astrophysics Data System (ADS)

Clark, Randal John

This thesis describes the development and validation of methods for damage tolerance substantiation of bonded composite repairs applied to cracked plates. This technology is used to repair metal aircraft structures, offering improvements in fatigue life, cost, manufacturability, and inspectability when compared to riveted repairs. The work focuses on the effects of plate thickness and bending on repair life, and covers fundamental aspects of fracture and fatigue of cracked plates and bonded joints. This project falls under the UBC Bonded Composite Repair Program, which has the goal of certification and widespread use of bonded repairs in civilian air transportation. This thesis analyses the plate thickness and transverse stress effects on fracture of repaired plates and the related problem of induced geometrically nonlinear bending in unbalanced (single-sided) repairs. The author begins by developing a classification scheme for assigning repair damage tolerance substantiation requirements based upon stress-based adhesive fracture/fatigue criteria and the residual strength of the original structure. The governing equations for bending of cracked plates are then reformulated and line-spring models are developed for linear and nonlinear coupled bending and extension of reinforced cracks. The line-spring models were used to correct the Wang and Rose energy method for the determination of the long-crack limit stress intensity, and to develop a new interpolation model for repaired cracks of arbitrary length. The analysis was validated using finite element models and data from mechanical tests performed on hybrid bonded joints and repair specimens that are representative of an in-service repair. This work will allow designers to evaluate the damage tolerance of the repaired plate, the adhesive, and the composite patch, which is an airworthiness requirement under FAR (Federal Aviation Regulations) 25.571. The thesis concludes by assessing the remaining barriers to certification of bonded repairs, discussing the results of the analysis, and making suggestions for future work. The developed techniques should also prove to be useful for the analysis of fibre-reinforced metal laminates and other layered structures. Some concepts are general and should be useful in the analysis of any plate with large in-plane stress gradients that lead to significant transverse stresses.

Monoarticular Arthritis.

PubMed

Singh, Namrata; Vogelgesang, Scott A

2017-05-01

Monoarticular arthritis is inflammation characterized by joint pain, swelling, and sometimes periarticular erythema. Although chronic causes are seen, the onset is often acute. An infected joint can quickly lead to permanent damage, making it a medical emergency. However, acute gout presenting as monoarticular arthritis is often so uncomfortable it requires urgent attention. Monoarticular crystalline arthritis is common and a septic joint is a medical emergency so it is no surprise that these diagnoses come to mind with complaint of inflammation in 1 joint. However, there are many causes of monoarticular arthritis that clinicians must consider. Copyright © 2016 Elsevier Inc. All rights reserved.

Central sensitization as the mechanism underlying pain in joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type.

PubMed

Di Stefano, G; Celletti, C; Baron, R; Castori, M; Di Franco, M; La Cesa, S; Leone, C; Pepe, A; Cruccu, G; Truini, A; Camerota, F

2016-09-01

Patients with joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type (JHS/EDS-HT) commonly suffer from pain. How this hereditary connective tissue disorder causes pain remains unclear although previous studies suggested it shares similar mechanisms with neuropathic pain and fibromyalgia. In this prospective study seeking information on the mechanisms underlying pain in patients with JHS/EDS-HT, we enrolled 27 consecutive patients with this connective tissue disorder. Patients underwent a detailed clinical examination, including the neuropathic pain questionnaire DN4 and the fibromyalgia rapid screening tool. As quantitative sensory testing methods, we included thermal-pain perceptive thresholds and the wind-up ratio and recorded a standard nerve conduction study to assess non-nociceptive fibres and laser-evoked potentials, assessing nociceptive fibres. Clinical examination and diagnostic tests disclosed no somatosensory nervous system damage. Conversely, most patients suffered from widespread pain, the fibromyalgia rapid screening tool elicited positive findings, and quantitative sensory testing showed lowered cold and heat pain thresholds and an increased wind-up ratio. While the lack of somatosensory nervous system damage is incompatible with neuropathic pain as the mechanism underlying pain in JHS/EDS-HT, the lowered cold and heat pain thresholds and increased wind-up ratio imply that pain in JHS/EDS-HT might arise through central sensitization. Hence, this connective tissue disorder and fibromyalgia share similar pain mechanisms. WHAT DOES THIS STUDY ADD?: In patients with JHS/EDS-HT, the persistent nociceptive input due to joint abnormalities probably triggers central sensitization in the dorsal horn neurons and causes widespread pain. © 2016 European Pain Federation - EFIC®

Structural health monitoring of compression connectors for overhead transmission lines

NASA Astrophysics Data System (ADS)

Wang, Hong; Wang, Jy-An John; Swindeman, Joseph P.; Ren, Fei; Chan, John

2017-04-01

Two-stage aluminum conductor steel-reinforced (ACSR) compression connectors are extensively used in US overhead transmission lines. The connectors are made by crimping a steel sleeve onto a steel core and an aluminum sleeve over electrical conducting aluminum strands. The connectors are designed to operate at temperatures up to 125°C, but their performance is increasingly degrading because of overloading of lines. Currently, electric utilities conduct routine line inspections using thermal and electrical measurements, but these methods do not provide information about the structural integrity of connectors. In this work, structural health monitoring (SHM) of compression connectors was studied using electromechanical impedance (EMI) analysis. Lead zirconate titanate (PZT)-5A was identified as a smart material for SHM. A flexible high-temperature bonding layer was used to address challenges in PZT integration due to a significant difference in the coefficients of thermal expansion of PZT and the aluminum substrate. The steel joint on the steel core was investigated because it is responsible for the ultimate tensile strength of the connector. Tensile testing was used to induce structural damage to the joint, or steel core pullout, and thermal cycling introduced additional structural perturbations. EMI measurements were conducted between the tests. The root mean square deviation (RMSD) of EMI was identified as a damage index. The use of steel joints has been shown to enable SHM under simulated conditions. The EMI signature is sensitive to variations in structural conditions. RMSD can be correlated to the structural health of a connector and has potential for use in the SHM and structural integrity evaluation.

US/Russian Joint Film Test

NASA Technical Reports Server (NTRS)

Slater, Richard

1996-01-01

A joint U.S./Russian film test was conducted during MIR Mission 18 to evaluate the effects of radiation on photographic film during long-duration space flights. Two duplicate sets of film were flown on this MIR mission: one set was processed and evaluated by the NASA/JSC Photographic Laboratory, and the other by the RKK Energia's Photographic Laboratory in Moscow. This preliminary report includes only the results of the JSC evaluation (excluding the SN-10 film which was not available for evaluation at the time this report was written). The final report will include an evaluation by JSC of the SN-10 film and an evaluation of the test data by the RKK Energia. ISC's evaluation of the test data showed the positive film flown was damaged very little when exposed to approximately 8 rads of radiation. Two of the three negative films were significantly damaged and the third film was damaged only moderately.

US/Russian Joint Film Test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slater, R.

1996-04-01

A joint U.S./Russian film test was conducted during MIR Mission 18 to evaluate the effects of radiation on photographic film during long-duration space flights. Two duplicate sets of film were flown on this MIR mission: one set was processed and evaluated by the NASA/JSC Photographic Laboratory, and the other by the RKK Energia`s Photographic Laboratory in Moscow. This preliminary report includes only the results of the JSC evaluation (excluding the SN-10 film which was not available for evaluation at the time this report was written). The final report will include an evaluation by JSC of the SN-10 film and anmore » evaluation of the test data by the RKK Energia. ISC`s evaluation of the test data showed the positive film flown was damaged very little when exposed to approximately 8 rads of radiation. Two of the three negative films were significantly damaged and the third film was damaged only moderately.« less

Obesity & osteoarthritis

PubMed Central

King, Lauren K.; March, Lyn; Anandacoomarasamy, Ananthila

2013-01-01

The most significant impact of obesity on the musculoskeletal system is associated with osteoarthritis (OA), a disabling degenerative joint disorder characterized by pain, decreased mobility and negative impact on quality of life. OA pathogenesis relates to both excessive joint loading and altered biomechanical patterns together with hormonal and cytokine dysregulation. Obesity is associated with the incidence and progression of OA of both weight-bearing and non weight-bearing joints, to rate of joint replacements as well as operative complications. Weight loss in OA can impart clinically significant improvements in pain and delay progression of joint structural damage. Further work is required to determine the relative contributions of mechanical and metabolic factors in the pathogenesis of OA. PMID:24056594

Long-term follow-up of the cervical spine with conventional radiographs in patients with rheumatoid arthritis.

PubMed

Blom, M; Creemers, M C W; Kievit, W; Lemmens, J A M; van Riel, P L C M

2013-01-01

To investigate the prevalence of cervical spine damage due to rheumatoid arthritis (RA) in the long term and to investigate which disease-specific factors are related to this damage. Patients with early RA from the Nijmegen inception cohort with 6 to 12 years of follow-up were included. Conventional radiographs of the cervical spine were obtained at baseline, 3, 6, 9, and 12 years and scored for erosions of C1 and C2, anterior atlantoaxial subluxation (AAS) and atlantoaxial impaction (AAI). Disease-specific factors, such as disease activity, functionality, and peripheral joint damage, at baseline, 3, 6, and 9 years, were compared between patients with and without cervical spine damage at 9 years. A total of 196 patients were included, of whom 134 had radiographs at 9 years. Cervical spine damage was present in 16% (22/134) of the patients at 9 years. During the total 12 years of follow-up, AAS and erosions of C2 were observed most frequently. Erosions of C1 and AAI were very rare. Patients with cervical spine damage at 9 years had a higher number of erosions of the peripheral joints and failed more disease-modifying anti-rheumatic drugs (DMARDs) at 3, 6, and 9 years. Patients without peripheral erosive disease at 3 years were unlikely to develop cervical spine damage within 9 years of disease duration. The prevalence of cervical spine damage due to RA was 16% at 9 years. Patients without peripheral erosive disease at 3 years were unlikely to develop cervical spine damage at 9 years.

Greater inadvertent muscle damage in direct anterior approach when compared with the direct superior approach for total hip arthroplasty.

PubMed

Amanatullah, D F; Masini, M A; Roger, D J; Pagnano, M W

2016-08-01

We wished to quantify the extent of soft-tissue damage sustained during minimally invasive total hip arthroplasty through the direct anterior (DA) and direct superior (DS) approaches. In eight cadavers, the DA approach was performed on one side, and the DS approach on the other, a single brand of uncemented hip prosthesis was implanted by two surgeons, considered expert in their surgical approaches. Subsequent reflection of the gluteus maximus allowed the extent of muscle and tendon damage to be measured and the percentage damage to each anatomical structure to be calculated. The DA approach caused substantially greater damage to the gluteus minimus muscle and tendon when compared with the DS approach (t-test, p = 0.049 and 0.003, respectively). The tensor fascia lata and rectus femoris muscles were damaged only in the DA approach. There was no difference in the amount of damage to the gluteus medius muscle and tendon, piriformis tendon, obturator internus tendon, obturator externus tendon or quadratus femoris muscle between approaches. The posterior soft-tissue releases of the DA approach damaged the gluteus minimus muscle and tendon, piriformis tendon and obturator internus tendon. The DS approach caused less soft-tissue damage than the DA approach. However the clinical relevance is unknown. Further clinical outcome studies, radiographic evaluation of component position, gait analyses and serum biomarker levels are necessary to evaluate and corroborate the safety and efficacy of the DS approach. Cite this article: Bone Joint J 2016;98-B1036-42. ©2016 The British Editorial Society of Bone & Joint Surgery.

COMPARISON BETWEEN COMPUTED TOMOGRAPHIC ARTHROGRAPHY, RADIOGRAPHY, ULTRASONOGRAPHY, AND ARTHROSCOPY FOR THE DIAGNOSIS OF FEMOROTIBIAL JOINT DISEASE IN WESTERN PERFORMANCE HORSES.

PubMed

Nelson, Brad B; Kawcak, Chris E; Goodrich, Laurie R; Werpy, Natasha M; Valdés-Martínez, Alejandro; McIlwraith, C Wayne

2016-07-01

The femorotibial joints are a common source of lameness in Western performance horses. The objective of this prospective study was to compare the radiography, ultrasonography, computed tomographic arthrography (CTA), and arthroscopy findings in horses with lameness localized to the femorotibial joints. Twenty-five stifles in 24 horses were included and were evaluated with all four of these diagnostic methods. Defects detected in femorotibial joint structures were compared between diagnostic methods using a McNemar's test to evaluate for disagreement. Cranial medial meniscotibial desmopathy was most detected on arthroscopy (in 14/25 cases) and was only detected on ultrasonography in three out of 11 (27.3%) arthroscopically observed cases, but was detected on CTA in nine out of 12 (75%) arthroscopically observed cases. Medial meniscal injury located on the craniolateral border was most detected on arthroscopy (n = 9) and was detected on CTA in five cases, but on ultrasonography in 0 cases. Detection of articular cartilage defects on the medial femoral condyle was most detected with arthroscopy (24/25, 96% cases) and was also detected on CTA in 12/20 (60%) cases with a significant disagreement identified between modalities (P = 0.02). Cranial and caudal cruciate ligament defects were detected on CTA in 6/22 (27.3%) and 7/19 (36.8%) cases, respectively, and with arthroscopy in 3/25 (12%) and 2/25 (8%) cases, respectively. The use of CTA detected more defects in the cruciate ligaments, proximal tibia, and ligament entheses than the other diagnostic methods, but was not reliable for detection of articular cartilage damage on the medial femoral condyle. © 2016 American College of Veterinary Radiology.

A Multidisciplinary Approach to Health Monitoring and Materials Damage Prognosis for Metallic Aerospace Systems

DTIC Science & Technology

2013-03-01

framework of orientation distribution functions and crack-induced texture o Quantify effects of temperature on damage behavior and damage monitoring...measurement model was obtained from hidden Markov modeling (HMM) of joint time-frequency (TF) features extracted from the PZT sensor signals using the...considered PZT sensor signals recorded from a bolted aluminum plate. About only 20% of the samples of a signal were first randomly selected as

Analysis and Characterization of Damage and Failure Utilizing a Generalized Composite Material Model Suitable for Use in Impact Problems

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Carney, Kelly S.; DuBois, Paul; Khaled, Bilal; Hoffarth, Canio; Rajan, Subramaniam; Blankenhorn, Gunther

2016-01-01

A material model which incorporates several key capabilities which have been identified by the aerospace community as lacking in state-of-the art composite impact models is under development. In particular, a next generation composite impact material model, jointly developed by the FAA and NASA, is being implemented into the commercial transient dynamic finite element code LS-DYNA. The material model, which incorporates plasticity, damage, and failure, utilizes experimentally based tabulated input to define the evolution of plasticity and damage and the initiation of failure as opposed to specifying discrete input parameters (such as modulus and strength). The plasticity portion of the orthotropic, three-dimensional, macroscopic composite constitutive model is based on an extension of the Tsai-Wu composite failure model into a generalized yield function with a non-associative flow rule. For the damage model, a strain equivalent formulation is utilized to allow for the uncoupling of the deformation and damage analyses. In the damage model, a semi-coupled approach is employed where the overall damage in a particular coordinate direction is assumed to be a multiplicative combination of the damage in that direction resulting from the applied loads in the various coordinate directions. Due to the fact that the plasticity and damage models are uncoupled, test procedures and methods to both characterize the damage model and to covert the material stress-strain curves from the true (damaged) stress space to the effective (undamaged) stress space have been developed. A methodology has been developed to input the experimentally determined composite failure surface in a tabulated manner. An analytical approach is then utilized to track how close the current stress state is to the failure surface.

Quadriceps Weakness, Patella Alta and Structural Features of Patellofemoral Osteoarthritis: The Multicenter Osteoarthritis Study

PubMed Central

Stefanik, Joshua J.; Guermazi, Ali; Zhu, Yanyan; Zumwalt, Ann C.; Gross, K. Douglas; Clancy, Margaret; Lynch, John A.; Segal, Neil A.; Lewis, Cora E.; Roemer, Frank W.; Powers, Christopher M.; Felson, David T.

2011-01-01

Objective To determine the relationship between quadriceps weakness and cartilage damage and bone marrow lesions (BMLs) in the patellofemoral joint (PFJ), and if this relationship is modified by patella alta. Methods The Multicenter Osteoarthritis (MOST) Study is a cohort study of persons aged 50–79 years with or at risk for knee OA. Concentric knee extensor strength was measured using an isokinetic dynamometer. Patella alta was measured using the Insall-Salvati ratio (ISR) on the lateral radiograph, and cartilage damage and bone marrow lesions (BMLs) were graded on MRI in the PFJ. We determined the association between quadriceps weakness with cartilage damage and BMLs in the PFJ among those knees with (ISR≥1.2) and without patella alta (ISR<1.2) using multiple binomial regression. Results 807 knees were studied (mean age 62 years, BMI 30, ISR 1.10), 64% from female subjects. Compared with knees in the highest strength tertile, those in the lowest had 10.2% {95% Confidence Interval (CI) 3–18}, 9.1% (95% CI 2–16), and 7.1% (95% CI 1–13) higher prevalence of lateral PFJ cartilage damage, medial PFJ cartilage damage, and lateral PFJ BMLs, respectively. The association between quadriceps weakness with cartilage damage and BMLs was not different between knees with and with out patella alta in the lateral PFJ. Conclusion Quadriceps weakness was associated with PFJ cartilage damage and BMLs. While both patella alta and quadriceps weakness are associated with PFJ damage, the combination of the two was not associated with more damage than either of these factors alone. PMID:21702087

Compact Telerobot Hand

NASA Technical Reports Server (NTRS)

Rosheim, Mark; Trechsel, Hans

1993-01-01

Anthropomorphic telerobotic hand contains actuators, joints, sensors, and complex wiring harnesses. Glove protects interior components of hand from dirt and damage. Imitates motions of human fingers and wrist in lifelike and dexterous way. Incorporates pitch/yaw joints in wrist and head knuckles. Hand modular; so fingers removable, interchangeable units. Feature simplifies servicing and maintenance, which must be done frequently in such complex mechanism.

Mechanical joining of materials with limited ductility: Analysis of process-induced defects

NASA Astrophysics Data System (ADS)

Jäckel, M.; Coppieters, S.; Hofmann, M.; Vandermeiren, N.; Landgrebe, D.; Debruyne, D.; Wallmersberger, T.; Faes, K.

2017-10-01

The paper shows experimental and numerical analyses of the clinching process of 6xxx series aluminum sheets in T6 condition and the self-pierce riveting process of an aluminum die casting. In the experimental investigations the damage behavior of the materials when using different tool parameters is analyzed. The focus of the numerical investigations is the damage prediction by a comparison of different damage criteria. Moreover, strength-and fatigue tests were carried out to investigate the influence of the joining process-induced damages on the strength properties of the joints.

Joint distraction attenuates osteoarthritis by reducing secondary inflammation, cartilage degeneration and subchondral bone aberrant change.

PubMed

Chen, Y; Sun, Y; Pan, X; Ho, K; Li, G

2015-10-01

Osteoarthritis (OA) is a progressive joint disorder. To date, there is not effective medical therapy. Joint distraction has given us hope for slowing down the OA progression. In this study, we investigated the benefits of joint distraction in OA rat model and the probable underlying mechanisms. OA was induced in the right knee joint of rats through anterior cruciate ligament transaction (ACLT) plus medial meniscus resection. The animals were randomized into three groups: two groups were treated with an external fixator for a subsequent 3 weeks, one with and one without joint distraction; and one group without external fixator as OA control. Serum interleukin-1β level was evaluated by ELISA; cartilage quality was assessed by histology examinations (gross appearance, Safranin-O/Fast green stain) and immunohistochemistry examinations (MMP13, Col X); subchondral bone aberrant changes was analyzed by micro-CT and immunohistochemistry (Nestin, Osterix) examinations. Characters of OA were present in the OA group, contrary to in general less severe damage after distraction treatment: firstly, IL-1β level was significantly decreased; secondly, cartilage degeneration was attenuated with lower histologic damage scores and the lower percentage of MMP13 or Col X positive chondrocytes; finally, subchondral bone abnormal change was attenuated, with reduced bone mineral density (BMD) and bone volume/total tissue volume (BV/TV) and the number of Nestin or Osterix positive cells in the subchondral bone. In the present study, we demonstrated that joint distraction reduced the level of secondary inflammation, cartilage degeneration and subchondral bone aberrant change, joint distraction may be a strategy for slowing OA progression. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Development of three-dimensional prints of arthritic joints for supporting patients' awareness to structural damage.

PubMed

Kleyer, Arnd; Beyer, Laura; Simon, Christoph; Stemmler, Fabian; Englbrecht, Matthias; Beyer, Christian; Rech, Jürgen; Manger, Bernhard; Krönke, Gerhard; Schett, Georg; Hueber, Axel J

2017-02-10

Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) result in severe joint destruction and functional disability if left untreated. We aim to develop tools that help patients with RA and PsA to understand and experience the impact of inflammatory joint disease on the integrity of their (juxta-articular) bone and increase adherence to medical treatment. In this study, we used high-resolution peripheral quantitative computed tomography (HR-pQCT) to develop 3D prototypes of patients' finger joints. HR-pQCT (XtremeCT, Scanco) measurements were performed in healthy individuals and patients with inflammatory joint disease, followed by a 3D print using the objet30 printer. Healthy participants (n = 10), and patients (n = 15 with RA and 15 with PsA) underwent a detailed, standardized interview with demonstration of printed joints. Utilizing HR-pQCT images of metacarpophalangeal (MCP) heads, high quality and exact 3D prints as prototypes were created. Erosions in different sizes and the trabecular network printed in detail were visualized, demonstrating structural reduction in arthritic vs. healthy bone. After demonstration of 3D prints (healthy vs. erosive joint, visual and haptic) 26/39 (66%) participants (including healthy volunteers) were deeply affected, often quoting "shock". Of the patients with RA and PsA, 13/15 (86%) and 11/15 (73%), respectively, stated that they would rethink their attitude to medication adherence. More importantly, 21/24 patients with RA or PsA (87.5%) expressed that they would have wished to see such 3D prints during their first disease-specific conversations. Using arthro-haptic 3D printed prototypes of joints may help to better understand the impact of inflammatory arthritides on bone integrity and long-term damage.

Comparison of the Tendon Damage Caused by Four Different Anchor Systems Used in Transtendon Rotator Cuff Repair

PubMed Central

Zhang, Qing-Song; Liu, Sen; Zhang, Qiuyang; Xue, Yun; Ge, Dongxia; O'Brien, Michael J.; Savoie, Felix H.; You, Zongbing

2012-01-01

Objectives. The objective of this study was to compare the damage to the rotator cuff tendons caused by four different anchor systems. Methods. 20 cadaveric human shoulder joints were used for transtendon insertion of four anchor systems. The Healix Peek, Fastin RC, Bio-Corkscrew Suture, and Healix Transtend anchors were inserted through the tendons using standard transtendon procedures. The areas of tendon damage were measured. Results. The areas of tendon damage (mean ± standard deviation, n = 7) were 29.1 ± 4.3 mm2 for the Healix Peek anchor, 20.4 ± 2.3 mm2 for the Fastin RC anchor, 23.4 ± 1.2 mm2 for the Bio-Corkscrew Suture anchor, 13.7 ± 3.2 mm2 for the Healix Transtend anchor inserted directly, and 9.1 ± 2.1 mm2 for the Healix Transtend anchor inserted through the Percannula system (P < 0.001 or P < 0.001, compared to other anchors). Conclusions. In a cadaver transtendon rotator cuff repair model, smaller anchors caused less damage to the tendon tissues. The Healix Transtend implant system caused the least damage to the tendon tissues. Our findings suggest that smaller anchors should be considered when performing transtendon procedures to repair partial rotator cuff tears. PMID:22811923

Seismic response and damage detection analyses of an instrumented steel moment-framed building

USGS Publications Warehouse

Rodgers, J.E.; Celebi, M.

2006-01-01

The seismic performance of steel moment-framed buildings has been of particular interest since brittle fractures were discovered at the beam-column connections in a number of buildings following the M 6.7 Northridge earthquake of January 17, 1994. A case study of the seismic behavior of an extensively instrumented 13-story steel moment frame building located in the greater Los Angeles area of California is described herein. Response studies using frequency domain, joint time-frequency, system identification, and simple damage detection analyses are performed using an extensive strong motion dataset dating from 1971 to the present, supported by engineering drawings and results of postearthquake inspections. These studies show that the building's response is more complex than would be expected from its highly symmetrical geometry. The response is characterized by low damping in the fundamental mode, larger accelerations in the middle and lower stories than at the roof and base, extended periods of vibration after the cessation of strong input shaking, beating in the response, elliptical particle motion, and significant torsion during strong shaking at the top of the concrete piers which extend from the basement to the second floor. The analyses conducted indicate that the response of the structure was elastic in all recorded earthquakes to date, including Northridge. Also, several simple damage detection methods employed did not indicate any structural damage or connection fractures. The combination of a large, real structure and low instrumentation density precluded the application of many recently proposed advanced damage detection methods in this case study. Overall, however, the findings of this study are consistent with the limited code-compliant postearthquake intrusive inspections conducted after the Northridge earthquake, which found no connection fractures or other structural damage. ?? ASCE.

Quantitative in vivo HR-pQCT imaging of 3D wrist and metacarpophalangeal joint space width in rheumatoid arthritis.

PubMed

Burghardt, Andrew J; Lee, Chan Hee; Kuo, Daniel; Majumdar, Sharmila; Imboden, John B; Link, Thomas M; Li, Xiaojuan

2013-12-01

In this technique development study, high-resolution peripheral quantitative computed tomography (HR-pQCT) was applied to non-invasively image and quantify 3D joint space morphology of the wrist and metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA). HR-pQCT imaging (82 μm voxel-size) of the dominant hand was performed in patients with diagnosed rheumatoid arthritis (RA, N = 16, age: 52.6 ± 12.8) and healthy controls (CTRL, N = 7, age: 50.1 ± 15.0). An automated computer algorithm was developed to segment wrist and MCP joint spaces. The 3D distance transformation method was applied to spatially map joint space width, and summarized by the mean joint space width (JSW), minimal and maximal JSW (JSW.MIN, JSW.MAX), asymmetry (JSW.AS), and distribution (JSW.SD)-a measure of joint space heterogeneity. In vivo precision was determined for each measure by calculating the smallest detectable difference (SDD) and root mean square coefficient of variation (RMSCV%) of repeat scans. Qualitatively, HR-pQCT images and pseudo-color JSW maps showed global joint space narrowing, as well as regional and focal abnormalities in RA patients. In patients with radiographic JSN at an MCP, JSW.SD was two-fold greater vs. CTRL (p < 0.01), and JSW.MIN was more than two-fold lower (p < 0.001). Similarly, JSW.SD was significantly greater in the wrist of RA patients vs. CTRL (p < 0.05). In vivo precision was highest for JSW (SDD: 100 μm, RMSCV: 2.1%) while the SDD for JSW.MIN and JSW.SD were 370 and 110 μm, respectively. This study suggests that in vivo quantification of 3D joint space morphology from HR-pQCT, could improve early detection of joint damage in rheumatological diseases.

Quantitative In Vivo HR-pQCT Imaging of 3D Wrist and Metacarpophalangeal Joint Space Width In Rheumatoid Arthritis

PubMed Central

Burghardt, Andrew J.; Lee, Chan Hee; Kuo, Daniel; Majumdar, Sharmila; Imboden, John B.; Link, Thomas M.; Li, Xiaojuan

2013-01-01

In this technique development study, high-resolution peripheral quantitative computed tomography (HR-pQCT) was applied to non-invasively image and quantify 3D joint space morphology of the wrist and metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA). HR-pQCT imaging (82μm voxel-size) of the dominant hand was performed in patients with diagnosed rheumatoid arthritis (RA, N=16, age:52.6±12.8) and healthy controls (CTRL, N=7, age:50.1±15.0). An automated computer algorithm was developed to segment wrist and MCP joint spaces. The 3D distance transformation method was applied to spatially map joint space width, and summarized by the mean joint space width (JSW), minimal and maximal JSW (JSW.MIN, JSW.MAX), asymmetry (JSW.AS), and distribution (JSW.SD) – a measure of joint space heterogeneity. In vivo precision was determined for each measure by calculating the smallest detectable difference (SDD) and root mean square coefficient of variation (RMSCV%) of repeat scans. Qualitatively, HR-pQCT images and pseudo-color JSW maps showed global joint space narrowing, as well as regional and focal abnormalities in RA patients. In patients with radiographic JSN at an MCP, JSW.SD was two-fold greater versus CTRL (p<0.01), and JSW.MIN was more than two-fold lower (p<0.001). Similarly, JSW.SD was significantly greater in the wrist of RA patients versus CTRL (p<0.05). In vivo precision was highest for JSW (SDD: 100μm, RMSCV: 2.1%) while the SDD for JSW.MIN and JSW.SD were 370 and 110μm, respectively. This study suggests that in vivo quantification of 3D joint space morphology from HR-pQCT, could improve early detection of joint damage in rheumatological diseases. PMID:23887879

Electromigration analysis of solder joints under ac load: A mean time to failure model

NASA Astrophysics Data System (ADS)

Yao, Wei; Basaran, Cemal

2012-03-01

In this study, alternating current (ac) electromigration (EM) degradation simulations were carried out for Sn95.5%Ag4.0%Cu0.5 (SAC405- by weight) solder joints. Mass transport analysis was conducted with viscoplastic material properties for quantifying damage mechanism in solder joints. Square, sine, and triangle current wave forms ac were used as input signals. dc and pulsed dc (PDC) electromigration analysis were conducted for comparison purposes. The maximum current density ranged from 2.2×106A/cm2 to 5.0×106A/cm2, frequency ranged from 0.05 Hz to 5 Hz with ambient temperature varying from 350 K to 450 K. Because the room temperature is nearly two-thirds of SAC solder joint's melting point on absolute temperature scale (494.15 K), viscoplastic material model is essential. Entropy based damage evolution model was used to investigate mean time to failure (MTF) behavior of solder joints subjected to ac stressing. It was observed that MTF was inversely proportional to ambient temperature T1.1 in Celsius and also inversely proportional to current density j0.27 in A/cm2. Higher frequency will lead to a shorter lifetime with in the frequency range we studied, and a relationship is proposed as MTF∝f-0.41. Lifetime of a solder joint subjected to ac is longer compared with dc and PDC loading conditions. By introducing frequency, ambient temperature and current density dependency terms, a modified MTTF equation was proposed for solder joints subjected to ac current stressing.

Co-existent sickle cell disease and juvenile rheumatoid arthritis. Two cases with delayed diagnosis and severe destructive arthropathy.

PubMed

Nistala, K; Murray, K J

2001-09-01

We describe 2 pediatric patients with sickle cell disease (SCD) who developed seropositive juvenile rheumatoid arthritis (JRA). Both patients have severe joint damage, the compound effect of both disease processes. The bone and cartilage destruction, which poses serious therapeutic challenges, highlights the difficulty of making a diagnosis of chronic inflammatory disease in the setting of SCD. There may be a correlation between increased levels of tumor necrosis factor-alpha in the synovial tissue of joints damaged by arthritis and local sickling. The resultant ischemia and corresponding inflammatory infiltrates could in turn worsen existing synovial proliferation and cartilage destruction as well as trigger further sickling.

Associated lateral/medial knee instability and its relevant factors in anterior cruciate ligament-injured knees.

PubMed

Yuuki, Arata; Muneta, Takeshi; Ohara, Toshiyuki; Sekiya, Ichiro; Koga, Hideyuki

2017-03-01

Associations of lateral/medial knee instability with anterior cruciate ligament (ACL) injury have not been thoroughly investigated. The purposes of this study were to investigate whether lateral/medial knee instability is associated with ACL injury, and to clarify relevant factors for lateral/medial knee instability in ACL-injured knees. One hundred and nineteen patients with unilateral ACL-injured knees were included. Lateral/medial knee instability was assessed with varus/valgus stress X-ray examination for both injured and uninjured knees by measuring varus/valgus angle, lateral/medial joint opening, and lateral/medial joint opening index. Manual knee instability tests for ACL were evaluated to investigate associations between lateral/medial knee instability and anterior and/or rotational instabilities. Patients' backgrounds were evaluated to identify relevant factors for lateral/medial knee instability. Damage on the lateral collateral ligament (LCL) on MRI was also evaluated. All parameters regarding lateral knee instability in injured knees were significantly greater than in uninjured knees. There were significant correlations between lateral knee instability and the Lachman test as well as the pivot shift test. Patients with LCL damage had significantly greater lateral joint opening than those without LCL damage on MRI. Sensitivity of LCL damage on MRI to lateral joint opening was 100%, while its specificity was 36%. No other relevant factors were identified. In medial knee instability, there were also correlations between medial knee instability and the Lachman test/pivot shift test. However, the correlations were weak and other parameters were not significant. Lateral knee instability was greater in ACL-deficient knees than in uninjured knees. Lateral knee instability was associated with ACL-related instabilities as well as LCL damage on MRI, whereas MRI had low specificity to lateral knee instability. On the other hand, the association of medial knee instability on ACL-related instability was less than that of lateral knee instability. Level IV, case series with no comparison group. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Image Registration-Based Bolt Loosening Detection of Steel Joints

PubMed Central

2018-01-01

Self-loosening of bolts caused by repetitive loads and vibrations is one of the common defects that can weaken the structural integrity of bolted steel joints in civil structures. Many existing approaches for detecting loosening bolts are based on physical sensors and, hence, require extensive sensor deployment, which limit their abilities to cost-effectively detect loosened bolts in a large number of steel joints. Recently, computer vision-based structural health monitoring (SHM) technologies have demonstrated great potential for damage detection due to the benefits of being low cost, easy to deploy, and contactless. In this study, we propose a vision-based non-contact bolt loosening detection method that uses a consumer-grade digital camera. Two images of the monitored steel joint are first collected during different inspection periods and then aligned through two image registration processes. If the bolt experiences rotation between inspections, it will introduce differential features in the registration errors, serving as a good indicator for bolt loosening detection. The performance and robustness of this approach have been validated through a series of experimental investigations using three laboratory setups including a gusset plate on a cross frame, a column flange, and a girder web. The bolt loosening detection results are presented for easy interpretation such that informed decisions can be made about the detected loosened bolts. PMID:29597264

Image Registration-Based Bolt Loosening Detection of Steel Joints.

PubMed

Kong, Xiangxiong; Li, Jian

2018-03-28

Self-loosening of bolts caused by repetitive loads and vibrations is one of the common defects that can weaken the structural integrity of bolted steel joints in civil structures. Many existing approaches for detecting loosening bolts are based on physical sensors and, hence, require extensive sensor deployment, which limit their abilities to cost-effectively detect loosened bolts in a large number of steel joints. Recently, computer vision-based structural health monitoring (SHM) technologies have demonstrated great potential for damage detection due to the benefits of being low cost, easy to deploy, and contactless. In this study, we propose a vision-based non-contact bolt loosening detection method that uses a consumer-grade digital camera. Two images of the monitored steel joint are first collected during different inspection periods and then aligned through two image registration processes. If the bolt experiences rotation between inspections, it will introduce differential features in the registration errors, serving as a good indicator for bolt loosening detection. The performance and robustness of this approach have been validated through a series of experimental investigations using three laboratory setups including a gusset plate on a cross frame, a column flange, and a girder web. The bolt loosening detection results are presented for easy interpretation such that informed decisions can be made about the detected loosened bolts.

Method for Estimating Thread Strength Reduction of Damaged Parent Holes with Inserts

NASA Technical Reports Server (NTRS)

Johnson, David L.; Stratton, Troy C.

2005-01-01

During normal assembly and disassembly of bolted-joint components, thread damage and/or deformation may occur. If threads are overloaded, thread damage/deformation can also be anticipated. Typical inspection techniques (e.g. using GO-NO GO gages) may not provide adequate visibility of the extent of thread damage. More detailed inspection techniques have provided actual pitch-diameter profiles of damaged-hardware holes. A method to predict the reduction in thread shear-out capacity of damaged threaded holes has been developed. This method was based on testing and analytical modeling. Test samples were machined to simulate damaged holes in the hardware of interest. Test samples containing pristine parent-holes were also manufactured from the same bar-stock material to provide baseline results for comparison purposes. After the particular parent-hole thread profile was machined into each sample a helical insert was installed into the threaded hole. These samples were tested in a specially designed fixture to determine the maximum load required to shear out the parent threads. It was determined from the pristine-hole samples that, for the specific material tested, each individual thread could resist an average load of 3980 pounds. The shear-out loads of the holes having modified pitch diameters were compared to the ultimate loads of the specimens with pristine holes. An equivalent number of missing helical coil threads was then determined based on the ratio of shear-out loads for each thread configuration. These data were compared with the results from a finite element model (FEM). The model gave insights into the ability of the thread loads to redistribute for both pristine and simulated damage configurations. In this case, it was determined that the overall potential reduction in thread load-carrying capability in the hardware of interest was equal to having up to three fewer threads in the hole that bolt threads could engage. One- half of this potential reduction was due to local pitch-diameter variations and the other half was due to overall pitch-diameter enlargement beyond Class 2 fit. This result was important in that the thread shear capacity for this particular hardware design was the limiting structural capability. The details of the method development, including the supporting testing, data reduction and analytical model results comparison will be discussed hereafter.

Composite skid landing gear design investigation

NASA Astrophysics Data System (ADS)

Shrotri, Kshitij

A Composite Skid Landing Gear Design investigation has been conducted. Limit Drop Test as per Federal Aviation Regulations (FAR) Part 27.725 and Crash test as per MIL STD 1290A (AV) were simulated using ABAQUS to evaluate performance of multiple composite fiber-matrix systems. Load factor developed during multiple landing scenarios and energy dissipated during crash were computed. Strength and stiffness based constraints were imposed. Tsai-Wu and LaRC04 physics based failure criteria were used for limit loads. Hashin's damage initiation criteria with Davila-Camanho's energy based damage evolution damage evolution law were used for crash. Initial results indicate that all single-composite skid landing gear may no be feasible due to strength concerns in the cross member bends. Hybridization of multiple composites with elasto-plastic aluminum 7075 showed proof of strength under limit loads. Laminate tailoring for load factor optimization under limit loads was done by parameterization of a single variable fiber orientation angle for multiple laminate families. Tsai-Wu failure criterion was used to impose strength contraints. A quasi-isotropic N = 4 (pi/4) 48 ply IM7/8552 laminate was shown to be the optimal solution with a load failure will be initiated as matrix cracking under compression and fiber kinking under in-plane shear and longitudinal compression. All failures under limit loads being reported in the metal-composite hybrid joint region, the joint was simulated by adhesive bonding and filament winding, separately. Simply adhesive bonding the metal and composite regions does not meet strength requirements. A filament wound metal-composite joint shows proof of strength. Filament wound bolted metal-composite joint shows proof of strength. Filament wound composite bolted to metal cross member radii is the final joining methodology. Finally, crash analysis was conducted as per requirements from MIL STD 1290A (AV). Crash at 42 ft/sec with 1 design gross weight (DGW) lift was simulated using ABAQUS. Plastic and friction energy dissipation in the reference aluminum skid landing gear was compared with plastic, friction and damage energy dissipation in the hybrid composite design. Damage in composites was modeled as progressive damage with Hashin's damage initiation criteria and an energy based damage evolution law. The latter meets requirements of aircraft kinetic energy dissipation up to 20 ft/sec (67.6 kJ) as per MIL STD 1290A (AV). Weight saving possibility of up to 49% over conventional metal skid landing gear is reported. The final design recommended includes Ke49/PEEK skids, 48 ply IM7/8552 (or IM7/PEEK) cross member tapered beams and Al 7075 cross member bend radii, the latter bolted to the filament wound composite-metal tapered beam. Concerns in composite skid landing gear designs, testing requirements and future opportunities are addressed.

Tumor necrosis factor inhibitor therapy but not standard therapy is associated with resolution of erosion in the sacroiliac joints of patients with axial spondyloarthritis

PubMed Central

2014-01-01

Introduction Radiography is an unreliable and insensitive tool for the assessment of structural lesions in the sacroiliac joints (SIJ). Magnetic resonance imaging (MRI) detects a wider spectrum of structural lesions but has undergone minimal validation in prospective studies. The Spondyloarthritis Research Consortium of Canada (SPARCC) MRI Sacroiliac Joint (SIJ) Structural Score (SSS) assesses a spectrum of structural lesions (erosion, fat metaplasia, backfill, ankylosis) and its potential to discriminate between therapies requires evaluation. Methods The SSS score assesses five consecutive coronal slices through the cartilaginous portion of the joint on T1-weighted sequences starting from the transitional slice between cartilaginous and ligamentous portions of the joint. Lesions are scored dichotomously (present/absent) in SIJ quadrants (fat metaplasia, erosion) or halves (backfill, ankylosis). Two readers independently scored 147 pairs (baseline, 2 years) of scans from a prospective cohort of patients with SpA who received either standard (n = 69) or tumor necrosis factor alpha (TNFα) inhibitor (n = 78) therapy. Smallest detectable change (SDC) was calculated using analysis of variance (ANOVA), discrimination was assessed using Guyatt’s effect size, and treatment group differences were assessed using t-tests and the Mann–Whitney test. We identified baseline demographic and structural damage variables associated with change in SSS score by univariate analysis and analyzed the effect of treatment by multivariate stepwise regression adjusted for severity of baseline structural damage and demographic variables. Results A significant increase in mean SSS score for fat metaplasia (P = 0.017) and decrease in mean SSS score for erosion (P = 0.017) was noted in anti-TNFα treated patients compared to those on standard therapy. Effect size for this change in SSS fat metaplasia and erosion score was moderate (0.5 and 0.6, respectively). Treatment and baseline SSS score for erosion were independently associated with change in SSS erosion score (β = 1.75, P = 0.003 and β = 0.40, P < 0.0001, respectively). Change in ASDAS (β = −0.46, P = 0.006), SPARCC MRI SIJ inflammation (β = −0.077, P = 0.019), and baseline SSS score for fat metaplasia (β = 0.085, P = 0.034) were independently associated with new fat metaplasia. Conclusion The SPARCC SSS method for assessment of structural lesions has discriminative capacity in demonstrating significantly greater reduction in erosion and new fat metaplasia in patients receiving anti-TNFα therapy. PMID:24755322

Antioxidant Effect of Spirulina (Arthrospira) maxima on Chronic Inflammation Induced by Freund's Complete Adjuvant in Rats

PubMed Central

Gutiérrez-Rebolledo, Gabriel Alfonso; Galar-Martínez, Marcela; García-Rodríguez, Rosa Virginia; Chamorro-Cevallos, Germán A.; Hernández-Reyes, Ana Gabriela

2015-01-01

Abstract One of the major mechanisms in the pathogenesis of chronic inflammation is the excessive production of reactive oxygen and reactive nitrogen species, and therefore, oxidative stress. Spirulina (Arthrospira) maxima has marked antioxidant activity in vivo and in vitro, as well as anti-inflammatory activity in certain experimental models, the latter activity being mediated probably by the antioxidant activity of this cyanobacterium. In the present study, chronic inflammation was induced through injection of Freund's complete adjuvant (CFA) in rats treated daily with Spirulina (Arthrospira) maxima for 2 weeks beginning on day 14. Joint diameter, body temperature, and motor capacity were assessed each week. On days 0 and 28, total and differential leukocyte counts and serum oxidative damage were determined, the latter by assessing lipid peroxidation and protein carbonyl content. At the end of the study, oxidative damage to joints was likewise evaluated. Results show that S. maxima favors increased mobility, as well as body temperature regulation, and a number of circulating leukocytes, lymphocytes, and monocytes in specimens with CFA-induced chronic inflammation and also protects against oxidative damage in joint tissue as well as serum. In conclusion, the protection afforded by S. maxima against development of chronic inflammation is due to its antioxidant activity. PMID:25599112

Returning to Overuse Activity Following a Supraspinatus and Infraspinatus Tear Leads to Joint Damage in a Rat Model

PubMed Central

Reuther, Katherine E.; Thomas, Stephen J.; Evans, Elisabeth F.; Tucker, Jennica J.; Sarver, Joseph J.; Ilkhani-Pour, Sarah; Gray, Chancellor F.; Voleti, Pramod; Glaser, David L.; Soslowsky, Louis J.

2013-01-01

Large rotator cuff tears (supraspinatus and infraspinatus) are common in patients that perform overhead activities (laborers, athletes). In addition, following large cuff tears, these patients commonly attempt to return to pre-injury activity levels. However, there is a limited understanding of the damaging effects on the uninjured joint tissues when doing so. Therefore, the objective of this study was to investigate the effect of returning to overuse activity following a supraspinatus and infraspinatus tear on shoulder function and the structural and biological properties of the intact tendons and glenoid cartilage. Forty rats underwent four weeks of overuse followed by detachment of the supraspinatus and infraspinatus tendons and were then randomized into two groups: return to overuse or cage activity. Ambulatory measurements were performed over time and structural and biologic properties of the adjacent tendons and cartilage were evaluated. Results demonstrated that animals returning to overuse activity did not have altered shoulder function but despite this, did have altered cartilage and tendon properties. These mechanical changes corresponded to altered transcriptional regulation of chondrogenic genes within cartilage and tendon. This study helps define the mechanical and biologic mechanisms leading to joint damage and provides a framework for treating active cuff tear patients. PMID:23764174

Antioxidant Effect of Spirulina (Arthrospira) maxima on Chronic Inflammation Induced by Freund's Complete Adjuvant in Rats.

PubMed

Gutiérrez-Rebolledo, Gabriel Alfonso; Galar-Martínez, Marcela; García-Rodríguez, Rosa Virginia; Chamorro-Cevallos, Germán A; Hernández-Reyes, Ana Gabriela; Martínez-Galero, Elizdath

2015-08-01

One of the major mechanisms in the pathogenesis of chronic inflammation is the excessive production of reactive oxygen and reactive nitrogen species, and therefore, oxidative stress. Spirulina (Arthrospira) maxima has marked antioxidant activity in vivo and in vitro, as well as anti-inflammatory activity in certain experimental models, the latter activity being mediated probably by the antioxidant activity of this cyanobacterium. In the present study, chronic inflammation was induced through injection of Freund's complete adjuvant (CFA) in rats treated daily with Spirulina (Arthrospira) maxima for 2 weeks beginning on day 14. Joint diameter, body temperature, and motor capacity were assessed each week. On days 0 and 28, total and differential leukocyte counts and serum oxidative damage were determined, the latter by assessing lipid peroxidation and protein carbonyl content. At the end of the study, oxidative damage to joints was likewise evaluated. Results show that S. maxima favors increased mobility, as well as body temperature regulation, and a number of circulating leukocytes, lymphocytes, and monocytes in specimens with CFA-induced chronic inflammation and also protects against oxidative damage in joint tissue as well as serum. In conclusion, the protection afforded by S. maxima against development of chronic inflammation is due to its antioxidant activity.

75 FR 81427 - Airworthiness Directives; The Boeing Company Model 747-200C, -200F, -400, -400D, and -400F Series...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-28

.... This AD results from a structural review of affected skin lap joints for widespread fatigue damage. We are issuing this AD to prevent fatigue cracking in certain lap joints, which could result in rapid... operation beyond 15,000 total flight cycles after doing the proposed modification. Boeing stated that...

Finite Element Modeling of Viscoelastic Behavior and Interface Damage in Adhesively Bonded Joints

DTIC Science & Technology

2012-01-01

eccentricity of the axis of a lap joint gives rise to transverse or peel stresses at the Report Documentation Page Form ApprovedOMB No. 0704-0188...Computers and Structures 29, 1011 (1988). 21 S. Roy and J. N. Reddy, Tire Sci. Technol. 16, 146 (1988). 22 S. Roy and J. N. Reddy, Intl. J. Numer

Neutrophils: Beneficial and Harmful Cells in Septic Arthritis

PubMed Central

Boff, Daiane; Crijns, Helena; Teixeira, Mauro M.

2018-01-01

Septic arthritis is an inflammatory joint disease that is induced by pathogens such as Staphylococcus aureus. Infection of the joint triggers an acute inflammatory response directed by inflammatory mediators including microbial danger signals and cytokines and is accompanied by an influx of leukocytes. The recruitment of these inflammatory cells depends on gradients of chemoattractants including formylated peptides from the infectious agent or dying cells, host-derived leukotrienes, complement proteins and chemokines. Neutrophils are of major importance and play a dual role in the pathogenesis of septic arthritis. On the one hand, these leukocytes are indispensable in the first-line defense to kill invading pathogens in the early stage of disease. However, on the other hand, neutrophils act as mediators of tissue destruction. Since the elimination of inflammatory neutrophils from the site of inflammation is a prerequisite for resolution of the acute inflammatory response, the prolonged stay of these leukocytes at the inflammatory site can lead to irreversible damage to the infected joint, which is known as an important complication in septic arthritis patients. Thus, timely reduction of the recruitment of inflammatory neutrophils to infected joints may be an efficient therapy to reduce tissue damage in septic arthritis. PMID:29401737

Current trends of microorganisms and their sensitivity pattern in paediatric septic arthritis: A prospective study from tertiary care level hospital.

PubMed

Motwani, Girish; Mehta, Rujuta; Aroojis, Alaric; Vaidya, Sandeep

2017-01-01

Early treatment of septic arthritis is essential before irreversible damage to the articular cartilage occurs. Clinicians often start empirical antibiotic therapy for symptomatic relief while awaiting a definitive culture report. In present day parlance with variations in different centres in the private and public sector and rampant antibiotic abuse, a lot of resistance is being seen in the flora and their sensitivity patterns. Hence it is imperative to document and analyze these changing trends. The authors conducted a retrospective analysis of prospectively gathered data of 60 patients under 14 years of age. Joint arthrotomy was performed as a standard therapeutic protocol and the drained pus or synovial fluid was sent for gram stain and culture by 2 different methods: conventional agar plate method and BACTEC Peds Plus/F bottle method. Antibiotic susceptibility tests were done by the disc diffusion method of Clinical Laboratory Standards Institute (CLSI). The commonest presenting age group was below 1 year (80% patients) including 24 neonates. There were 19 hospital and 41 community acquired cases of septic arthritis. The hip (56%) was the commonest affected joint followed by knee (28%), shoulder joint (11%) and elbow (5%). Microorganism was isolated in 53% isolates of joint fluid only (36 culture positive patients). Conventional agar methods of culture showed positive report in only 42% patients (15/36 patients) while with the BACTEC method the yield was 71%. In the Community acquired septic arthritis, methicillin sensitive Staphylococcus aureus was isolated as commonest microbe while resistant variety of gram negative bacilli including E. coli and Klebsiella were found as predominant organism causing hospital acquired nosocomial infection of joints. The results strikingly differ in terms of response to treatment as most patients (11/19 patients) showed significant resistance to the most commonly practiced empirical antibiotic regimen of ampicillin-cloxacillin group in routine practice. When cefazolin was used as empirical antibiotic, it has shown good response and better sensitivity in 82% patients (27/33 patients). S. aureus is still the most common organism in septic arthritis. The BACTEC system was found to improve the yield of clinically significant isolates. Though a significant resistance to common antibiotic regimen is noticed, the strain is susceptible to cephalosporin group of antibiotics. We recommend the use of cephalosporine antibiotics as an empirical therapy till culture and sensitivity report are available.

Tenascin-C Prevents Articular Cartilage Degeneration in Murine Osteoarthritis Models.

PubMed

Matsui, Yuriyo; Hasegawa, Masahiro; Iino, Takahiro; Imanaka-Yoshida, Kyoko; Yoshida, Toshimichi; Sudo, Akihiro

2018-01-01

Objective The objective of this study was to determine whether intra-articular injections of tenascin-C (TNC) could prevent cartilage damage in murine models of osteoarthritis (OA). Design Fluorescently labeled TNC was injected into knee joints and its distribution was examined at 1 day, 4 days, 1 week, 2 weeks, and 4 weeks postinjection. To investigate the effects of TNC on cartilage degeneration after surgery to knee joints, articular spaces were filled with 100 μg/mL (group I), 10 μg/mL (group II) of TNC solution, or control (group III). TNC solution of 10 μg/mL was additionally injected twice after 3 weeks (group IV) or weekly after 1 week, 2 weeks, and 3 weeks (group V). Joint tissues were histologically assessed using the Mankin score and the modified Chambers system at 2 to 8 weeks after surgery. Results Exogenous TNC was maintained in the cartilage and synovium for 1 week after administration. Histological scores in groups I and II were better than scores in group III at 4 and 6 weeks, but progressive cartilage damage was seen in all groups 8 weeks postoperatively. Sequential TNC injections (groups IV and V) showed significantly better Mankin score than single injection (group II) at 8 weeks. Conclusion TNC administered exogenously remained in the cartilage of knee joints for 1 week, and could decelerate articular cartilage degeneration in murine models of OA. We also showed that sequential administration of TNC was more effective than a single injection. TNC could be an important molecule for prevention of articular cartilage damage.

Vectra DA for the objective measurement of disease activity in patients with rheumatoid arthritis.

PubMed

Segurado, O G; Sasso, E H

2014-01-01

Quantitative and regular assessment of disease activity in rheumatoid arthritis (RA) is required to achieve treatment targets such as remission and to optimize clinical outcomes. To assess inflammation accurately, predict joint damage and monitor treatment response, a measure of disease activity in RA should reflect the pathological processes resulting in irreversible joint damage and functional disability. The Vectra DA blood test is an objective measure of disease activity for patients with RA. Vectra DA provides an accurate, reproducible score on a scale of 1 to 100 based on the concentrations of 12 biomarkers that reflect the pathophysiologic diversity of RA. The analytical validity, clinical validity, and clinical utility of Vectra DA have been evaluated for patients with RA in registries and prospective and retrospective clinical studies. As a biomarker-based instrument for assessing disease activity in RA, the Vectra DA test can help monitor therapeutic response to methotrexate and biologic agents and assess clinically challenging situations, such as when clinical measures are confounded by non-inflammatory pain from fibromyalgia. Vectra DA scores correlate with imaging of joint inflammation and are predictive for radiographic progression, with high Vectra DA scores being associated with more frequent and severe progression and low scores being predictive for non-progression. In summary, the Vectra DA score is an objective measure of RA disease activity that quantifies inflammatory status. By predicting risk for joint damage more effectively than conventional clinical and laboratory measures, it has the potential to complement these measures and optimise clinical decision making.

Wear of ultra-high molecular weight polyethylene against damaged and undamaged stainless steel and diamond-like carbon-coated counterfaces.

PubMed

Firkins, P; Hailey, J L; Fisher, J; Lettington, A H; Butter, R

1998-10-01

The wear of ultra-high molecular weight polyethylene (UHMWPE) in artificial joints and the resulting wear debris-induced osteolysis remains a major clinical concern in the orthopaedic sector. Third-body damage of metallic femoral heads is often cited as a cause of accelerated polyethylene wear, and the use of ceramic femoral heads in the hip is gaining increasing favour. In the knee prostheses and for smaller diameter femoral heads, the application of hard surface coatings, such as diamond-like carbon, is receiving considerable attention. However, to date, there has been little or no investigation of the tribology of these coatings in simulated biological environments. In this study, diamond-like carbon (DLC) has been compared to stainless steel in its undamaged form and following simulated third-body damage. The wear of UHMWPE was found to be similar when sliding against undamaged DLC and stainless steel counterfaces. DLC was found to be much more damage resistant than DLC. Under test conditions that simulate third-body damage to the femoral head, the wear of UHMWPE was seven times lower against DLC than against stainless steel (P < 0.05). The study shows DLC has considerable potential as a femoral bearing surface in artificial joints.

Assembly Test Article (ATA)

NASA Technical Reports Server (NTRS)

Ricks, Glen A.

1988-01-01

The assembly test article (ATA) consisted of two live loaded redesigned solid rocket motor (RSRM) segments which were assembled and disassembled to simulate the actual flight segment stacking process. The test assembly joint was flight RSRM design, which included the J-joint insulation design and metal capture feature. The ATA test was performed mid-November through 24 December 1987, at Kennedy Space Center (KSC), Florida. The purpose of the test was: certification that vertical RSRM segment mating and separation could be accomplished without any damage; verification and modification of the procedures in the segment stacking/destacking documents; and certification of various GSE to be used for flight assembly and inspection. The RSRM vertical segment assembly/disassembly is possible without any damage to the insulation, metal parts, or seals. The insulation J-joint contact area was very close to the predicted values. Numerous deviations and changes to the planning documents were made to ensure the flight segments are effectively and correctly stacked. Various GSE were also certified for use on flight segments, and are discussed in detail.

Innate Immunity Sensors Participating in Pathophysiology of Joint Diseases: A Brief Overview

PubMed Central

Gallo, Jiri; Raska, Milan; Konttinen, Yrjö T.; Nich, Christophe; Goodman, Stuart B.

2015-01-01

The innate immune system consists of functionally specialized “modules” that are activated in response to a particular set of stimuli via sensors located on the surface or inside the tissue cells. These cells screen tissues for a wide range of exogenous and endogenous danger/damage-induced signals with the aim to reject or tolerate them and maintain tissue integrity. In this line of thinking, inflammation evolved as an adaptive tool for restoring tissue homeostasis. A number of diseases are mediated by a maladaptation of the innate immune response, perpetuating chronic inflammation and tissue damage. Here, we review recent evidence on the cross talk between innate immune sensors and development of rheumatoid arthritis, osteoarthritis, and aseptic loosening of total joint replacements. In relation to the latter topic, there is a growing body of evidence that aseptic loosening and periprosthetic osteolysis results from long-term maladaptation of periprosthetic tissues to the presence of by-products continuously released from an artificial joint. PMID:25747032

Root Cause Investigation of the Starboard Solar Alpha Rotary Joint Anomaly on the International Space Station

NASA Technical Reports Server (NTRS)

Taylor, Deneen; Enriquez, Carlos; McCann, David; McFatter, Justin

2010-01-01

The Solar Alpha Rotary Joint (SARJ) is a single-axis pointing mechanism used to orient the solar power generating arrays relative to the sun for the International Space Station (ISS). Approximately 83 days after its on-orbit installation, one of the two SARJ mechanisms aboard the ISS began to exhibit high current draw. Later inspections via Extravehicular Activity (EVA) discovered that the case hardened steel race ring on the outboard side of the joint had extensive damage to one of its three rolling surfaces. A far-reaching investigation of the anomaly was undertaken, comprising metallurgical inspections, coupon tests, traction kinematics tests, detailed bearing measurements, and thermal and structural analyses. The investigation found that the race ring damage had been caused by high bearing edge stresses that resulted from inadequate lubrication of the rolling contact. The profile of the roller bearings and the metallurgical properties of the race ring were also found to be significant contributing factors.

Giant Cells Osseous Tumor in the Tarsal Canal after Lateral Ankle Sprain

PubMed Central

Lughi, Marcello

2018-01-01

Ankle sprain can cause injuries to the anatomic structures surrounding the tibiotarsal joint. A possible extra-articular pathology is to be hypothesized and diagnosed as early as possible. The subtalar joint, for anatomical and functional reasons, is one of the most damaged joints following an ankle sprain. In spite of this, its involvement is often underestimated. The clinical case presented in the present article is referred to a giant cells osseous tumor in the tarsal canal that was diagnosed 2 months after an inversion ankle sprain. PMID:29675509

[Comparative evolution surgical accesses to temporo-mandibular joint].

PubMed

Sysoliatin, P G; Novikov, A I; Sysoliatin, S P; Bobylev, N G; Brega, I N

2007-01-01

In experiment on 30 corpses of adult people criteria of an operational wound (depth of a wound, a corner of operational action, an axis of operational action, a corner of an inclination of operational action) were studied at preauricularis, intrauricularis, intrauriculo-temporalis and posterior mandibullaris access to temporo-mandibular joint (TMJ). New surgical intrauriculo-temporalis access to the joint is substantrated. On the basis of the analysis of 289 operations at 268 patients the indications to a choice of surgical access were developed at various diseases and damages of TMJ.

Microstructural effects on constitutive and fatigue fracture behavior of TinSilverCopper solder

NASA Astrophysics Data System (ADS)

Tucker, Jonathon P.

As microelectronic package construction becomes more diverse and complex, the need for accurate, geometry-independent material constitutive and failure models increases. Evaluations of packages based on accelerated environmental tests (such as accelerated thermal cycling or power cycling) only provide package-dependent reliability information. In addition, extrapolations of such test data to life predictions under field conditions are often empirical. Besides geometry, accelerated environmental test data must account for microstructural factors such as alloy composition or isothermal aging condition, resulting in expensive experimental variation. In this work, displacement-controlled, creep, and fatigue lap shear tests are conducted on specially designed SnAgCu test specimens with microstructures representative to those found in commercial microelectronic packages. The data are used to develop constitutive and fatigue fracture material models capable of describing deformation and fracture behavior for the relevant temperature and strain rate ranges. Furthermore, insight is provided into the microstructural variation of solder joints and the subsequent effect on material behavior. These models are appropriate for application to packages of any geometrical construction. The first focus of the thesis is on Pb-mixed SnAgCu solder alloys. During the transition from Pb-containing solders to Pb-free solders, joints composed of a mixture of SnPb and SnAgCu often result from either mixed assemblies or rework. Three alloys of 1, 5 and 20 weight percent Pb were selected so as to represent reasonable ranges of Pb contamination expected from different 63Sn37Pb components mixed with Sn3.0Ag0.5Cu. Displacement-controlled (constant strain rate) and creep tests were performed at temperatures of 25°C, 75°C, and 125°C using a double lap shear test setup that ensures a nearly homogeneous state of plastic strain at the joint interface. Rate-dependent constitutive models for Pb-contaminated SnAgCu solder alloys ranging from the traditional time-hardening creep model to the viscoplastic Anand model are described. The second focus of the thesis is on fatigue damage accumulation in SnAgCu solder alloys. While, typical fatigue fracture models are empirical, recently a non-empirical model termed Maximum Entropy Fracture Model (MEFM) was proposed. MEFM is a thermodynamically consistent and information theory inspired damage accumulation theory for ductile solids. This model has been validated recently for Sn3.8Ag0.7Cu solder alloy, and uses a single damage accumulation parameter to relate the probability of fracture to accumulated entropic dissipation. Isothermal cycling fatigue tests on Sn3.0Ag0.5Cu and mixed SnPb/Sn3.0Ag0.5Cu solder alloys at varying strain rates and temperatures are conducted using a custom-built microscale mechanical tester capable of submicron displacement resolution. MEFM is applied here in conjunction with the Anand viscoplasticity model to predict the softening occurring over successive cycles as a result of damage accumulation. The damage accumulation parameters for Sn3.0Ag0.5Cu in different aged states are related to a microstructural parameter which quantitatively describes the state of coarsening. In addition, damage accumulation parameters for the three mixed solder alloys are reported. This approach allows for a non-empirical prediction of both constitutive and fracture behavior of packages of different geometries and different microstructural states under thermo-mechanical fatigue. Approaches to solder joint reliability predictions from materials science and mechanics perspectives differ dramatically. Materials science methods identify key failure mechanisms, but most models cannot predict failure. In contrast, mechanics approaches often provide estimates of joint lifetime, but fail to provide insight into microstructural influences. This work attempts to connect the two fields by relating constitutive behavior and fatigue fracture models for different alloys and aging conditions to one or more microstructural parameters.

Low dose native type II collagen prevents pain in a rat osteoarthritis model

PubMed Central

2013-01-01

Background Osteoarthritis is the most widespread joint-affecting disease. Patients with osteoarthritis experience pain and impaired mobility resulting in marked reduction of quality of life. A progressive cartilage loss is responsible of an evolving disease difficult to treat. The characteristic of chronicity determines the need of new active disease modifying drugs. Aim of the present research is to evaluate the role of low doses of native type II collagen in the rat model of osteoarthritis induced by sodium monoiodoacetate (MIA). Methods 1, 3 and 10 mg kg-1 porcine native type II collagen were daily per os administered for 13 days starting from the day of MIA intra-articular injection. Results On day 14, collagen-treated rats showed a significant prevention of pain threshold alterations induced by MIA. Evaluation were performed on paws using mechanical noxious (Paw pressure test) or non-noxious (Electronic Von Frey test) stimuli, and a decrease of articular pain was directly measured on the damaged joint (PAM test). The efficacy of collagen in reducing pain was as higher as the dose was lowered. Moreover, a reduced postural unbalance, measured as hind limb weight bearing alterations (Incapacitance test), and a general improvement of motor activity (Animex test) were observed. Finally, the decrease of plasma and urine levels of CTX-II (Cross Linked C-Telopeptide of Type II Collagen), a biomarker of cartilage degradation, suggests a collagen-dependent decrease of structural joint damage. Conclusions These results describe the preclinical efficacy of low dosages of native type II collagen as pain reliever by a mechanism that involves a protective effect on cartilage. PMID:23915264

In vivo cyclic compression causes cartilage degeneration and subchondral bone changes in mouse tibiae

PubMed Central

Ko, Frank C.; Dragomir, Cecilia; Plumb, Darren A.; Goldring, Steven R.; Wright, Timothy M.; Goldring, Mary B.; van der Meulen, Marjolein C.H.

2013-01-01

Objectives Alterations in the mechanical loading environment in joints may have both beneficial and detrimental effects on articular cartilage and subchondral bone and subsequently influence the development of osteoarthritis (OA). We used an in vivo tibial loading model to investigate the adaptive responses of cartilage and bone to mechanical loading and to assess the influence of load level and duration. Methods We applied cyclic compression of 4.5 and 9.0N peak loads to the left tibia via the knee joint of adult (26-week-old) C57Bl/6 male mice for 1, 2, and 6 weeks. Only 9.0N loading was utilized in young (10-week-old) mice. The changes in articular cartilage and subchondral bone were analyzed by histology and microcomputed tomography. Results Loading promoted cartilage damage in both age groups, with increased damage severity dependent upon the duration of loading. Metaphyseal bone mass increased in the young mice, but not in the adult mice, whereas epiphyseal cancellous bone mass decreased with loading in both young and adult mice. Articular cartilage thickness decreased, and subchondral cortical bone thickness increased in the posterior tibial plateau in both age groups. Both age groups developed periarticular osteophytes at the tibial plateau in response to the 9.0N load, but no osteophyte formation occurred in adult mice subjected to 4.5N peak loading. Conclusion This non-invasive loading model permits dissection of temporal and topographical changes in cartilage and bone and will enable investigation of the efficacy of treatment interventions targeting joint biomechanics or biological events that promote OA onset and progression. PMID:23436303

Failure Predictions of Out-of-Autoclave Sandwich Joints with Delaminations under Flexure Loads

NASA Technical Reports Server (NTRS)

Nordendale, Nikolas; Goyal, Vinay; Lundgren, Eric; Patel, Dhruv; Farrokh, Babak; Jones, Justin; Fischetti, Grace; Segal, Kenneth

2015-01-01

An analysis and a test program was conducted to investigate the damage tolerance of composite sandwich joints. The joints contained a single circular delamination between the face-sheet and the doubler. The coupons were fabricated through out-of-autoclave (OOA) processes, a technology NASA is investigating for joining large composite sections. The four-point bend flexure test was used to induce compression loading into the side of the joint where the delamination was placed. The compression side was chosen since it tends to be one of the most critical loads in launch vehicles. Autoclave cure was used to manufacture the composite sandwich sections, while the doubler was co-bonded onto the sandwich face-sheet using an OOA process after sandwich panels were cured. A building block approach was adopted to characterize the mechanical properties of the joint material, including the fracture toughness between the doubler and facesheet. Twelve four-point-bend samples were tested, six in the sandwich core ribbon orientation and six in sandwich core cross-ribbon direction. Analysis predicted failure initiation and propagation at the pre-delaminated location, consistent with experimental observations. A building block approach using fracture analyses methods predicted failure loads in close agreement with tests. This investigation demonstrated a small strength reduction due to a flaw of significant size compared to the width of the sample. Therefore, concerns of bonding an OOA material to an in-autoclave material was mitigated for the geometries, materials, and load configurations considered.

Failure Predictions of Out-of-Autoclave Sandwich Joints with Delaminations Under Flexure Loads

NASA Technical Reports Server (NTRS)

Nordendale, Nikolas A.; Goyal, Vinay K.; Lundgren, Eric C.; Patel, Dhruv N.; Farrokh, Babak; Jones, Justin; Fischetti, Grace; Segal, Kenneth N.

2015-01-01

An analysis and a test program was conducted to investigate the damage tolerance of composite sandwich joints. The joints contained a single circular delamination between the face-sheet and the doubler. The coupons were fabricated through out-of-autoclave (OOA) processes, a technology NASA is investigating for joining large composite sections. The four-point bend flexure test was used to induce compression loading into the side of the joint where the delamination was placed. The compression side was chosen since it tends to be one of the most critical loads in launch vehicles. Autoclave cure was used to manufacture the composite sandwich sections, while the doubler was co-bonded onto the sandwich face-sheet using an OOA process after sandwich panels were cured. A building block approach was adopted to characterize the mechanical properties of the joint material, including the fracture toughness between the doubler and face-sheet. Twelve four-point-bend samples were tested, six in the sandwich core ribbon orientation and six in sandwich core cross-ribbon direction. Analysis predicted failure initiation and propagation at the pre-delaminated location, consistent with experimental observations. A building block approach using fracture analyses methods predicted failure loads in close agreement with tests. This investigation demonstrated a small strength reduction due to a flaw of significant size compared to the width of the sample. Therefore, concerns of bonding an OOA material to an in-autoclave material was mitigated for the geometries, materials, and load configurations considered.

Failure Predictions of Out-of-Autoclave Sandwich Joints with Delaminations Under Flexure Loads

NASA Technical Reports Server (NTRS)

Nordendale, Nikolas; Goyal, Vinay; Lundgren, Eric; Patel, Dhruv; Farrokh, Babak; Jones, Justin; Fischetti, Grace; Segal, Kenneth

2015-01-01

An analysis and a test program was conducted to investigate the damage tolerance of composite sandwich joints. The joints contained a single circular delamination between the face-sheet and the doubler. The coupons were fabricated through out-of-autoclave (OOA) processes, a technology NASA is investigating for joining large composite sections. The four-point bend flexure test was used to induce compression loading into the side of the joint where the delamination was placed. The compression side was chosen since it tends to be one of the most critical loads in launch vehicles. Autoclave cure was used to manufacture the composite sandwich sections, while the doubler was co-bonded onto the sandwich face-sheet using an OOA process after sandwich panels were cured. A building block approach was adopted to characterize the mechanical properties of the joint material, including the fracture toughness between the doubler and face-sheet. Twelve four-point-bend samples were tested, six in the sandwich core ribbon orientation and six in sandwich core cross-ribbon direction. Analysis predicted failure initiation and propagation at the pre-delaminated location, consistent with experimental observations. Fracture analyses methods predicted failure loads in close agreement with tests. This investigation demonstrated a strength reduction of 10 percent due to a flaw of significant size compared to the width of the sample. Therefore, concerns of bonding an OOA material to an in-autoclave material was mitigated for the geometries, materials, and load configurations considered.

A Mechanistic Thermal Fatigue Model for SnAgCu Solder Joints

NASA Astrophysics Data System (ADS)

Borgesen, Peter; Wentlent, Luke; Hamasha, Sa'd.; Khasawneh, Saif; Shirazi, Sam; Schmitz, Debora; Alghoul, Thaer; Greene, Chris; Yin, Liang

2018-02-01

The present work offers both a complete, quantitative model and a conservative acceleration factor expression for the life span of SnAgCu solder joints in thermal cycling. A broad range of thermal cycling experiments, conducted over many years, has revealed a series of systematic trends that are not compatible with common damage functions or constitutive relations. Complementary mechanical testing and systematic studies of the evolution of the microstructure and damage have led to a fundamental understanding of the progression of thermal fatigue and failure. A special experiment was developed to allow the effective deconstruction of conventional thermal cycling experiments and the finalization of our model. According to this model, the evolution of damage and failure in thermal cycling is controlled by a continuous recrystallization process which is dominated by the coalescence and rotation of dislocation cell structures continuously added to during the high-temperature dwell. The dominance of this dynamic recrystallization contribution is not consistent with the common assumption of a correlation between the number of cycles to failure and the total work done on the solder joint in question in each cycle. It is, however, consistent with an apparent dependence on the work done during the high-temperature dwell. Importantly, the onset of this recrystallization is delayed by pinning on the Ag3Sn precipitates until these have coarsened sufficiently, leading to a model with two terms where one tends to dominate in service and the other in accelerated thermal cycling tests. Accumulation of damage under realistic service conditions with varying dwell temperatures and times is also addressed.

Chronic Changes in the Articular Cartilage and Meniscus Following Traumatic Impact to the Lapine Knee

PubMed Central

Fischenich, Kristine M.; Button, Keith D.; Coatney, Garrett A.; Fajardo, Ryan S.; Leikert, Kevin M.; Haut, Roger C.; Haut Donahue, Tammy L.

2014-01-01

The objective of this study was to induce anterior cruciate ligament (ACL) and meniscal damage, via a single tibiofemoral compressive impact, in order to document articular cartilage and meniscal changes post impact. Tibiofemoral joints of Flemish Giant rabbits were subjected to a single blunt impact that ruptured the ACL and produced acute meniscal damage. Animals were allowed unrestricted cage activity for 12 weeks before euthanasia. India ink analysis of the articular cartilage revealed higher degrees of surface damage on the impacted tibias (p=0.018) and femurs (p<0.0001) compared to controls. Chronic meniscal damage was most prevalent in the medial central and medial posterior regions. Mechanical tests revealed an overall 19.4% increase in tibial plateau cartilage thickness (p=0.026), 34.8% increase in tibial plateau permeability (p=0.054), 40.8% increase in femoral condyle permeability (p=0.029), and 20.1% decrease in femoral condyle matrix modulus (p=0.012) in impacted joints compared to controls. Both the instantaneous and equilibrium moduli of the lateral and medial menisci were decreased compared to control (p<0.02). Histological analyses revealed significantly increased presence of fissures in the medial femur (p = 0.036). In both the meniscus and cartilage there was a significant decrease in GAG coverage for the impacted limbs. Based on these results it is clear that an unattended combined meniscal and ACL injury results in significant changes to the soft tissues in this experimental joint 12 weeks post injury. Such changes are consistent with a clinical description of mid to late stage PTOA of the knee. PMID:25523754

Prevalence and relevance of antibodies to type-I and -II collagen in synovial fluid of dogs with cranial cruciate ligament damage.

PubMed

de Rooster, H; Cox, E; van Bree, H

2000-11-01

To measure and compare synovial fluid antibody titers to type-I and -II collagen in stifle joints with instability caused by complete or partial cranial cruciate ligament (CCL) rupture and joints with osteoarthrosis secondary to other pathologic changes in dogs. 82 dogs with diseased stifle joints. Synovial fluid samples were collected from 7 dogs with clinically normal stifles (control group) and 82 dogs with diseased joints (50 stifle joints with complete rupture of the CCL, 20 with partial damage of the CCL, and 12 joints with radiographic signs of osteoarthritis secondary to other arthropathies). Synovial fluid samples were tested for autoantibodies to type-I and -II collagen by an ELISA. In dogs with complete and partial CCL rupture, synovial fluid antibody titers to type-I and -II collagen were significantly increased, compared with control dogs. Forty-eight percent (24/50) of samples from dogs with complete CCL rupture and 35% (7/20) of samples from dogs with partial CCL rupture had antibody titers to type-I collagen that were greater than the mean plus 2 standard deviations of the control group titers. Synovial fluid antibody titers to type-II collagen were high in 40% of the dogs with partial or (8/20) complete (20/50) CCL rupture. Dogs with osteoarthrosis secondary to other pathologic changes had significantly increased synovial fluid antibodies to type-I and -II collagen, compared with control dogs. Increases in autoantibodies to collagen in synovial fluid are not specific for the type of joint disorder. It is unlikely that the anticollagen antibodies play an active role in the initiation of weakening of the CCL.

Health Professionals' Perceptions of the Effects of Exercise on Joint Health in Rheumatoid Arthritis Patients.

PubMed

Halls, Serena; Law, Rebecca-Jane; Jones, Jeremy G; Markland, David A; Maddison, Peter J; Thom, Jeanette M

2017-09-01

Although exercise is an important factor in the management of rheumatoid arthritis (RA), research indicates that patients perceive that health professionals (HPs) are uncertain about the place of exercise in treatment and its relationship with joint damage. The present study investigated the perceptions of HPs regarding the effects of exercise on joint health in RA patients. A questionnaire investigating perceptions of exercise and joint health was distributed via professional networks and websites. Confirmatory factor analysis (CFA) was used to analyse questionnaire data and develop a focus group interview guide. Focus groups were conducted with multidisciplinary teams (MDTs) of rheumatology HPs and analysed using framework analysis. A total of 137 rheumatology HPs (95 female; 27-65 years of age) completed questionnaires. CFA showed that a four-factor model provided a marginally acceptable fit. Analysis of four focus groups (n = 24; 19 female; 30-60 years of age) identified five themes relating to HPs' perceptions of exercise and joint health in RA patients: 'Exercise is beneficial', 'Concerns about damage to joints', 'Patients have barriers to exercise', 'HP knowledge differs' and 'Patients may think service delivery is vague'. HPs were highly aware of the benefits and importance of exercise for RA patients. However, to remove the patient perception that HPs lack certainty and clarity regarding exercise it is important to ensure: (i) consistent promotion of exercise across the whole MDT; (ii) clear provision of information regarding rest, joint protection and exercise; (iii) HP education to ensure consistent, accurate knowledge, and understanding of the potential for conflicting advice when promoting exercise as part of an MDT. Copy © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Creating Defense Excellence: Defense Addendum to Road Map for National Security

DTIC Science & Technology

2001-05-15

occasionally distrust political appointees—many of whom can be young , inexperienced academics—as “interlopers” who can severely damage well-established...centralization, lost managerial competence, and the loss of Service esprit de corps. The centralized approach may instill greater efficiency toward a...This is necessary because the evolution of joint warfighting and defense economics has shifted many past roles and responsibilities to joint and

75 FR 13046 - Airworthiness Directives; The Boeing Company Model 747-200C, -200F, -400, -400D, and -400F Series...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-18

.... This proposed AD results from a structural review of affected skin lap joints for widespread fatigue damage. We are proposing this AD to prevent fatigue cracking in certain lap joints, which could result in...., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service...

Leg Injuries and Disorders

MedlinePlus

... are important for motion and standing. Playing sports, running, falling, or having an accident can damage your legs. Common leg injuries include sprains and strains, joint dislocations, and fractures. ...

Characterization of articular cartilage and subchondral bone changes in the rat anterior cruciate ligament transection and meniscectomized models of osteoarthritis.

PubMed

Hayami, Tadashi; Pickarski, Maureen; Zhuo, Ya; Wesolowski, Gregg A; Rodan, Gideon A; Duong, Le T

2006-02-01

Osteoarthritis (OA) is a chronic joint disease characterized by cartilage destruction, subchondral bone sclerosis, and osteophyte formation. Subchondral bone stiffness has been proposed to initiate and/or contribute to cartilage deterioration in OA. The purpose of this study was to characterize subchondral bone remodeling, cartilage damage, and osteophytosis during the disease progression in two models of surgically induced OA. Rat knee joints were subjected either to anterior cruciate ligament transection (ACLT) alone or in combination with resection of medial menisci (ACLT + MMx). Histopathological changes in the surgical joints were compared with sham at 1, 2, 4, 6, and 10 weeks post-surgery. Using a modified Mankin scoring system, we demonstrate that articular cartilage damage occurs within 2 weeks post-surgery in both surgical models. Detectable cartilage surface damage and proteoglycan loss were observed as early as 1 week post-surgery. These were followed by the increases in vascular invasion into cartilage, in loss of chondrocyte number and in cell clustering. Histomorphometric analysis revealed subchondral bone loss in both models within 2 weeks post-surgery followed by significant increases in subchondral bone volume relative to sham up to 10 weeks post-surgery. Incidence of osteophyte formation was optimally observed in ACLT joints at 10 weeks and in ACLT + MMx joints at 6 weeks post-surgery. In summary, the two surgically induced rat OA models share many characteristics seen in human and other animal models of OA, including progressive articular cartilage degradation, subchondral bone sclerosis, and osteophyte formation. Moreover, increased subchondral bone resorption is associated with early development of cartilage lesions, which precedes significant cartilage thinning and subchondral bone sclerosis. Together, these findings support a role for bone remodeling in OA pathogenesis and suggest that these rat models are suitable for evaluating bone resorption inhibitors as potential disease-modifying pharmaco-therapies.

[Cytokines in bone diseases. Anti-cytokine therapies for bone and joint diseases].

PubMed

Tanaka, Yoshiya

2010-10-01

The efficacy of biologics targeting inflammatory cytokines such as TNF and IL-6 for bone and joint diseases has been emerging. Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic synovitis and bone damage. By the use of TNF-inhibitors, clinical remission, structural remission and functional remission have become possible during the treatment of RA. Especially, the progress of joint and bone destruction is completely suppressed by TNF-inhibitors in the vast majority of RA patients. On the other hand, anti-RANKL antibody inhibits joint destruction as well as systemic osteoporosis, though no effects on synovitis of RA. Thus, differential efficacy of different therapies in bone destruction and osteoporosis would warrant further study to clarify the mechanisms of bone and joints diseases.

Damage Control Surgery and the Joint Solution

DTIC Science & Technology

2017-06-01

IV. THE SERVICES ’ OPERATE, TRAIN AND EQUIP FOR DEPLOYMENT OF DCS 13 V. COURSES OF ACTION 20 VI. CONCLUSION...Figure 14: Notional Service Enlisted Specialty Training Timeline 25 Figure 15: Timeline of Events for Base Hospital #28...implications for casualty care. Lastly, a short excerpt on how each Service organizes, trains and equips their personnel for the delivery of damage control

Overcoming Barriers to Firewise Actions by Residents. Final Report to Joint Fire Science Program

Treesearch

James D. Absher; Jerry J. Vaske; Katie M. Lyon

2013-01-01

Encouraging the public to take action (e.g., creating defensible space) that can reduce the likelihood of wildfire damage and decrease the likelihood of injury is a common approach to increasing wildfire safety and damage mitigation. This study was designed to improve our understanding of both individual and community actions that homeowners currently do or might take...

Arthroscopic Management of Scaphoid-Trapezium-Trapezoid Joint Arthritis.

PubMed

Pegoli, Loris; Pozzi, Alessandro

2017-11-01

Scaphoid-trapezium-trapezoid (STT) joint arthritis is a common condition consisting of pain on the radial side of the wrist and base of the thumb, swelling, and tenderness over the STT joint. Common symptoms are loss of grip strength and thumb function. There are several treatments, from symptomatic conservative treatment to surgical solutions, such as arthrodesis, arthroplasties, and prosthesis implant. The role of arthroscopy has grown and is probably the best treatment of this condition. Advantages of arthroscopic management of STT arthritis are faster recovery, better view of the joint during surgery, and possibility of creating less damage to the capsular and ligamentous structures. Copyright © 2017 Elsevier Inc. All rights reserved.

Further Simplification of the Simple Erosion Narrowing Score With Item Response Theory Methodology.

PubMed

Oude Voshaar, Martijn A H; Schenk, Olga; Ten Klooster, Peter M; Vonkeman, Harald E; Bernelot Moens, Hein J; Boers, Maarten; van de Laar, Mart A F J

2016-08-01

To further simplify the simple erosion narrowing score (SENS) by removing scored areas that contribute the least to its measurement precision according to analysis based on item response theory (IRT) and to compare the measurement performance of the simplified version to the original. Baseline and 18-month data of the Combinatietherapie Bij Reumatoide Artritis (COBRA) trial were modeled using longitudinal IRT methodology. Measurement precision was evaluated across different levels of structural damage. SENS was further simplified by omitting the least reliably scored areas. Discriminant validity of SENS and its simplification were studied by comparing their ability to differentiate between the COBRA and sulfasalazine arms. Responsiveness was studied by comparing standardized change scores between versions. SENS data showed good fit to the IRT model. Carpal and feet joints contributed the least statistical information to both erosion and joint space narrowing scores. Omitting the joints of the foot reduced measurement precision for the erosion score in cases with below-average levels of structural damage (relative efficiency compared with the original version ranged 35-59%). Omitting the carpal joints had minimal effect on precision (relative efficiency range 77-88%). Responsiveness of a simplified SENS without carpal joints closely approximated the original version (i.e., all Δ standardized change scores were ≤0.06). Discriminant validity was also similar between versions for both the erosion score (relative efficiency = 97%) and the SENS total score (relative efficiency = 84%). Our results show that the carpal joints may be omitted from the SENS without notable repercussion for its measurement performance. © 2016, American College of Rheumatology.

Implication of general anaesthetic and sedation techniques in temporomandibular joint disorders - a systematic review.

PubMed

Talaván-Serna, J; Montiel-Company, J M; Bellot-Arcís, C; Almerich-Silla, J M

2017-02-01

The purpose of this study was to conduct a systematic review of the literature on temporomandibular joint damage directly related to general anaesthesia and sedation. We searched MEDLINE, SCOPUS and the COCHRANE Library for titles and abstracts containing terms related to the subject. The search delimiters were analytical and descriptive studies with abstracts in Spanish, German, English or French, with no time limit. The search was updated in January 2015. Of the 398 articles found, 89 were duplicates and only 28 were of interest. Of these, 23 (82.14%) were case and case series reports, 4 (14.28%) were longitudinal studies and 1 (3.57%) was a cross-sectional study. General anaesthesia and sedation are risk factors for temporomandibular joint damage because of the drop in muscle tone caused by the drugs employed and because of airway management manoeuvres involving the joint. Joint complications have been described with spontaneous ventilation as well as with ventilation assisted by a face or laryngeal mask and with intubation. They are more frequent in women and/or patients with previous temporomandibular problems. Proper assessment is required both before and after anaesthesia or sedation in order to foresee and avoid or minimize temporomandibular complications. The data should be treated with caution, as the evidence of case and case series reports is not of a high standard and the small number of analytical studies is not entirely comparable. General anaesthesia and sedation techniques can influence the onset of temporomandibular joint disorders. More studies are needed to provide better clinical evidence. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The effects of high-dose methotrexate on the development of cartilage lesions in a lapine model of osteoarthrosis.

PubMed

Neidel, J; Schroers, B; Sintermann, F

1998-01-01

To determine whether systemic administration of methotrexate (MTX) can prevent joint destruction in experimental osteoarthrosis (OA) in rabbits, the disorder was induced unilaterally in the knee joints of 40 rabbits by partial medial meniscectomy and sectioning of the medial collateral and both cruciate ligaments. A sham operation (arthrotomy only) was performed in another four animals. Effects on the cartilage of the femoral condyles were studied after 6 and 12 weeks. Twelve weeks after induction, femoral and tibial osteophyte formation was demonstrated on radiographs in all cases. Marked cartilage damage was found histologically (median Mankin score 10 vs 1 for non-operated controls; P < 0.05, Wilcoxon test). Cartilage proteoglycan (GAG) content (dye binding assay) was reduced in operated joints [63 +/- 8 (mean +/- SEM) vs 75 +/- 6 micrograms chondroitin sulfate/mg cartilage wet weight], and the leukocyte count in the joints was elevated (226 +/- 14 vs 7 +/- 3 leukocytes per microliter joint aspirate after injection of 0.5 ml saline solution; both P < 0.05, Wilcoxon test). The rate of GAG synthesis was unchanged (ex vivo labelling with 35S-sulfate). Treatment with MTX (30 mg x kg body weight-1 x week-1 i.m., starting 12 h postoperatively) reduced cartilage damage (median Mankin score 8 vs 10 for placebo, P < 0.05, Mann-Whitney U-test), but had no significant effect on the other parameters tested. No significant MTX effects were observed on cartilage from nonoperated joints. Our data indicate that MTX may have a limited therapeutic effect in experimental OA in the rabbit.

ELER software - a new tool for urban earthquake loss assessment

NASA Astrophysics Data System (ADS)

Hancilar, U.; Tuzun, C.; Yenidogan, C.; Erdik, M.

2010-12-01

Rapid loss estimation after potentially damaging earthquakes is critical for effective emergency response and public information. A methodology and software package, ELER-Earthquake Loss Estimation Routine, for rapid estimation of earthquake shaking and losses throughout the Euro-Mediterranean region was developed under the Joint Research Activity-3 (JRA3) of the EC FP6 Project entitled "Network of Research Infrastructures for European Seismology-NERIES". Recently, a new version (v2.0) of ELER software has been released. The multi-level methodology developed is capable of incorporating regional variability and uncertainty originating from ground motion predictions, fault finiteness, site modifications, inventory of physical and social elements subjected to earthquake hazard and the associated vulnerability relationships. Although primarily intended for quasi real-time estimation of earthquake shaking and losses, the routine is also equally capable of incorporating scenario-based earthquake loss assessments. This paper introduces the urban earthquake loss assessment module (Level 2) of the ELER software which makes use of the most detailed inventory databases of physical and social elements at risk in combination with the analytical vulnerability relationships and building damage-related casualty vulnerability models for the estimation of building damage and casualty distributions, respectively. Spectral capacity-based loss assessment methodology and its vital components are presented. The analysis methods of the Level 2 module, i.e. Capacity Spectrum Method (ATC-40, 1996), Modified Acceleration-Displacement Response Spectrum Method (FEMA 440, 2005), Reduction Factor Method (Fajfar, 2000) and Coefficient Method (ASCE 41-06, 2006), are applied to the selected building types for validation and verification purposes. The damage estimates are compared to the results obtained from the other studies available in the literature, i.e. SELENA v4.0 (Molina et al., 2008) and ATC-55 (Yang, 2005). An urban loss assessment exercise for a scenario earthquake for the city of Istanbul is conducted and physical and social losses are presented. Damage to the urban environment is compared to the results obtained from similar software, i.e. KOERILoss (KOERI, 2002) and DBELA (Crowley et al., 2004). The European rapid loss estimation tool is expected to help enable effective emergency response, on both local and global level, as well as public information.

Interphalangeal Osteoarthritis Radiographic Simplified (iOARS) score: a radiographic method to detect osteoarthritis of the interphalangeal finger joints based on its histopathological alterations.

PubMed

Sunk, Ilse-Gerlinde; Amoyo-Minar, Love; Stamm, Tanja; Haider, Stefanie; Niederreiter, Birgit; Supp, Gabriela; Soleiman, Afschin; Kainberger, Franz; Smolen, Josef S; Bobacz, Klaus

2014-11-01

To develop a radiographic score for assessment of hand osteoarthritis (OA) that is based on histopathological alterations of the distal (DIP) and proximal (PIP) interphalangeal joints. DIP and PIP joints were obtained from corpses (n=40). Plain radiographies of these joints were taken. Joint samples were prepared for histological analysis; cartilage damage was graded according to the Mankin scoring system. A 2×2 Fisher's exact test was applied to define those radiographic features most likely to be associated with histological alterations. Receiver operating characteristic curves were analysed to determine radiographic thresholds. Intraclass correlation coefficients (ICC) estimated intra- and inter-reader variability. Spearman's correlation was applied to examine the relationship between our score and histopathological changes. Differences between groups were determined by a Student's t test. The Interphalangeal Osteoarthritis Radiographic Simplified (iOARS) score is presented. The score is based on histopathological changes of DIP and PIP joints and follows a simple dichotomy whether OA is present or not. The iOARS score relies on three equally ranked radiographic features (osteophytes, joint space narrowing and subchondral sclerosis). For both DIP and PIP joints, the presence of one x-ray features reflects interphalangeal OA. Sensitivity and specificity for DIP joints were 92.3% and 90.9%, respectively, and 75% and 100% for PIP joints. All readers were able to reproduce their own readings in DIP and PIP joints after 4 weeks. The overall agreement between the three readers was good; ICCs ranged from 0.945 to 0.586. Additionally, outcomes of the iOARS score in a hand OA cohort revealed a higher prevalence of interphalangeal joint OA compared with the Kellgren and Lawrence score. The iOARS score is uniquely based on histopathological alterations of the interphalangeal joints in order to reliably determine OA of the DIP and PIP joints radiographically. Its high specificity and sensitivity together with the dichotomous approach renders the iOARS score reliable, fast to perform and easy to apply. This tool may not only be valuable in daily clinical practice but also in clinical and epidemiological trials. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

A Case Report of an Acromioclavicular Joint Ganglion Associated with a Rotator Cuff Tear.

PubMed

Tanaka, Suguru; Gotoh, Masafumi; Mitsui, Yasuhiro; Shirachi, Isao; Okawa, Takahiro; Higuchi, Fujio; Shiba, Naoto

2017-04-13

We report a case of subcutaneous ganglion adjacent to the acromioclavicular joint with massive rotator cuff tear [1-7]. An 81-year-old woman presented with a ganglion adjacent to the acromioclavicular joint that had first been identified 9 months earlier. The ganglion had recurred after having been aspirated by her local physician, so she was referred to our hospital. The puncture fluid was yellowish, clear and viscous. Magnetic resonance imaging identified a massive rotator cuff tear with multi- lobular cystic lesions continuous to the acromioclavicular joint, presenting the "geyser sign". During arthroscopy, distal clavicular resection and excision of the ganglion were performed together with joint debridement. At present, the ganglion has not recurred and the patient has returned to normal daily activity. In this case, the ganglion may have developed subsequent to the concomitant massive cuff tear, due to subcutaneous fluid flow through the damaged acromioclavicular joint.

Valuation of damages to recreational trout fishing in the Upper Northeast due to acidic deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Englin, J.E.; Cameron, T.A.; Mendelsohn, R.E.

1991-04-01

This report documents methods used to estimate economic models of changes in recreational fishing due to the acidic deposition. The analysis was conducted by Pacific Northwest Laboratory (PNL) and its subcontractors for the US Environmental Protection Agency (EPA) and the US Department of Energy (DOE) in support of the National Acidic Precipitation Assessment Program (NAPAP). The primary data needed to estimate these models were collected in the 1989 Aquatic Based Recreation Survey (ABRS), which was jointly funded by the DOE and the EPA's Office of Policy Planning and Evaluation. 11 refs., 5 figs., 15 tabs.

Biomedical, translational and clinical research on PDT of TMJ

NASA Astrophysics Data System (ADS)

Kamenoff, J.

2017-02-01

Electromagnetic energy of laser light has some typical properties which are found to be a premise for discussions on laser irradiation abilities to control the severe and chronic disorders in TMJ. In world literature PDT application is recommended when soft tissues in TMJ are damaged, in cases of degenerative diseases of discus articularis, medial and lateral distensions of joint ligaments, chronic inflammatory processes in TMJ, occlusion trauma, etc. The aim of our clinical study was to analyze the theoretical achievements up to now in depth and basing on our clinic al observations suggest new methods guaranteeing high therapeutic efficacy of Photodynamic therapy.

Evaluation of a collagenase generated osteoarthritis biomarker in the synovial fluid from elbow joints of dogs with medial coronoid disease and unaffected dogs.

PubMed

Prink, Adam; Hayashi, Kei; Kim, Sun-Young; Kim, James; Kapatkin, Amy

2010-01-01

To evaluate whether synovial fluid concentrations of an osteoarthritis biomarker in dysplastic canine elbows with medial coronoid disease (MCD) are elevated compared with unaffected elbows and to determine if these concentrations correlate to the degree of articular cartilage damage. Cross sectional clinical study. Dogs (n=19; 35 elbows) with MCD and dogs (8; 16 elbows) with unaffected elbows. Concentrations of a collagenase-generated cleavage neoepitope of type II collagen (Col2-3/4C(long mono), or C2C) in joint fluid from elbows were analyzed and compared between dogs with MCD and unaffected dogs. Correlation of C2C concentration with subjective grading of articular cartilage surface damage was also evaluated. Mean (+/-SD) C2C concentration from MCD dogs was significantly higher (112.3+/-24.8 ng/mL) than in unaffected dogs (76.1+/-16.9 ng/mL; P<.05). There was a moderate correlation between cartilage damage grade and increasing C2C concentrations (P<.05, r=0.62) C2C concentrations are elevated in the synovial fluid of dogs with MCD compared with unaffected elbows, and a moderate, significant correlation was identified between these concentrations and subjective grading of articular cartilage damage. This preliminary data suggest that C2C concentrations in synovial fluid may have potential as a biomarker for diagnosis of articular cartilage damage associated with MCD and as a means of objectively determining the degree of articular cartilage damage.

Adalimumab with Methotrexate in Treatment-Naïve Japanese Patients with Rheumatoid Arthritis at Risk of Progressive Structural Joint Damage: A Postmarketing Observational Study.

PubMed

Ito, Yukiko; Hozumi, Kaori; Okada, Yukiko; Kurimoto, Sarina

2017-06-01

The objective of this study was to evaluate the real-world safety and effectiveness of adalimumab with methotrexate (MTX) in disease-modifying antirheumatic drug (DMARD)- and biologic-naïve Japanese patients with rheumatoid arthritis (RA) at risk of progressive structural joint damage. This multicenter, prospective, observational, postmarketing surveillance study was conducted between February 2013 and April 2015 at 84 centers in Japan. Patients with RA at risk of progressive structural joint damage were enrolled and initiated treatment with adalimumab and MTX. Adverse events were recorded up to week 28. Effectiveness/disease activity was assessed using the Disease Activity Score based on a 28-joint count with erythrocyte sedimentation rate and C-reactive protein (DAS28-4ESR and DAS28-4CRP), Clinical Disease Activity Index, and Simplified Disease Activity Index at 0, 4, 12, and 24 weeks. DAS28-4CRP response was evaluated in the low-dose (<8 mg/week) and high-dose (≥8 mg to ≤16 mg/week) MTX groups at week 24. One hundred fifty-seven of 163 patients comprised the safety cohort: mean (SD) age, 56.5 (13.9) years; females, 65.6%; rheumatoid factor positive, 73.2%; anti-cyclic citrullinated peptide antibody positive, 66.9%; bone erosions, 51.6%; mean disease duration, 9.5 months. The majority of patients (≥80%) had moderate or high disease activity at baseline, and ≥50% with available data achieved remission or low disease activity at week 24 (DAS28-4CRP <3.2). Five serious adverse drug reactions occurred in four patients, including pyelonephritis, Pneumocystis jiroveci pneumonia, interstitial lung disease, pleurisy, and pericarditis; the outcomes were either recovered or recovering. Significant improvements/reductions in disease activity over 24 weeks were noted in all effectiveness measures (P < 0.0001). Most of the population achieved DAS28-4CRP remission (<2.6) at week 24 regardless of the MTX dose. Adalimumab in combination with MTX could be a beneficial treatment option for DMARD- and biologic-naïve Japanese patients with RA at risk of progressive structural joint damage. AbbVie GK and Eisai. ClinicalTrials.gov identifier, NCT01783730.

Pelvic joint fusion in patients with severe pelvic girdle pain – a prospective single-subject research design study

PubMed Central

2014-01-01

Background The fusion of the pelvic joints in patients with severe pelvic girdle pain (PGP) is a controversial and insufficiently studied procedure. The aims of this study were to evaluate physical function and pain after sacroiliac joint (SIJ) fusion. Methods A single-subject research design study with repeated measurements was conducted; pre-operatively and at 3, 6 and 12 months post-operatively. The outcome measures considered were the Oswestry disability index (ODI), visual analogue scale (VAS), and SF-36. Eight patients with severe PGP received open-accessed unilateral anterior SIJ fusion and fusion of the pubic symphysis. Results Seven patients reported positive results from the surgery. At 1 year post-operation, significant (p < 0.001) reductions in ODI (54 to 37) and VAS (82 to 57) were reported. The physical functioning, bodily pain, and social functioning scores in the SF-36 were also improved. Conclusion Positive and significant changes in disability and pain at 1 year after SIJ fusion were observed. Despite these positive results, open accessed anterior fusion of the SIJ was associated with adverse events and complications such as infection and nerve damage. PMID:24629145

Contribution for new genetic markers of rheumatoid arthritis activity and severity: sequencing of the tumor necrosis factor-alpha gene promoter.

PubMed

Fonseca, João Eurico; Cavaleiro, João; Teles, José; Sousa, Elsa; Andreozzi, Valeska L; Antunes, Marília; Amaral-Turkman, Maria A; Canhão, Helena; Mourão, Ana F; Lopes, Joana; Caetano-Lopes, Joana; Weinmann, Pamela; Sobral, Marta; Nero, Patrícia; Saavedra, Maria J; Malcata, Armando; Cruz, Margarida; Melo, Rui; Braña, Araceli; Miranda, Luis; Patto, José V; Barcelos, Anabela; da Silva, José Canas; Santos, Luís M; Figueiredo, Guilherme; Rodrigues, Mário; Jesus, Herberto; Quintal, Alberto; Carvalho, Teresa; da Silva, José A Pereira; Branco, Jaime; Queiroz, Mário Viana

2007-01-01

The objective of this study was to assess whether clinical measures of rheumatoid arthritis activity and severity were influenced by tumor necrosis factor-alpha (TNF-alpha) promoter genotype/haplotype markers. Each patient's disease activity was assessed by the disease activity score using 28 joint counts (DAS28) and functional capacity by the Health Assessment Questionnaire (HAQ) score. Systemic manifestations, radiological damage evaluated by the Sharp/van der Heijde (SvdH) score, disease-modifying anti-rheumatic drug use, joint surgeries, and work disability were also assessed. The promoter region of the TNF-alpha gene, between nucleotides -1,318 and +49, was sequenced using an automated platform. Five hundred fifty-four patients were evaluated and genotyped for 10 single-nucleotide polymorphism (SNP) markers, but 5 of these markers were excluded due to failure to fall within Hardy-Weinberg equilibrium or to monomorphism. Patients with more than 10 years of disease duration (DD) presented significant associations between the -857 SNP and systemic manifestations, as well as joint surgeries. Associations were also found between the -308 SNP and work disability in patients with more than 2 years of DD and radiological damage in patients with less than 10 years of DD. A borderline effect was found between the -238 SNP and HAQ score and radiological damage in patients with 2 to 10 years of DD. An association was also found between haplotypes and the SvdH score for those with more than 10 years of DD. An association was found between some TNF-alpha promoter SNPs and systemic manifestations, radiological progression, HAQ score, work disability, and joint surgeries, particularly in some classes of DD and between haplotypes and radiological progression for those with more than 10 years of DD.

Contribution for new genetic markers of rheumatoid arthritis activity and severity: sequencing of the tumor necrosis factor-alpha gene promoter

PubMed Central

Fonseca, João Eurico; Cavaleiro, João; Teles, José; Sousa, Elsa; Andreozzi, Valeska L; Antunes, Marília; Amaral-Turkman, Maria A; Canhão, Helena; Mourão, Ana F; Lopes, Joana; Caetano-Lopes, Joana; Weinmann, Pamela; Sobral, Marta; Nero, Patrícia; Saavedra, Maria J; Malcata, Armando; Cruz, Margarida; Melo, Rui; Braña, Araceli; Miranda, Luis; Patto, José V; Barcelos, Anabela; da Silva, José Canas; Santos, Luís M; Figueiredo, Guilherme; Rodrigues, Mário; Jesus, Herberto; Quintal, Alberto; Carvalho, Teresa; da Silva, José A Pereira; Branco, Jaime; Queiroz, Mário Viana

2007-01-01

The objective of this study was to assess whether clinical measures of rheumatoid arthritis activity and severity were influenced by tumor necrosis factor-alpha (TNF-α) promoter genotype/haplotype markers. Each patient's disease activity was assessed by the disease activity score using 28 joint counts (DAS28) and functional capacity by the Health Assessment Questionnaire (HAQ) score. Systemic manifestations, radiological damage evaluated by the Sharp/van der Heijde (SvdH) score, disease-modifying anti-rheumatic drug use, joint surgeries, and work disability were also assessed. The promoter region of the TNF-α gene, between nucleotides -1,318 and +49, was sequenced using an automated platform. Five hundred fifty-four patients were evaluated and genotyped for 10 single-nucleotide polymorphism (SNP) markers, but 5 of these markers were excluded due to failure to fall within Hardy-Weinberg equilibrium or to monomorphism. Patients with more than 10 years of disease duration (DD) presented significant associations between the -857 SNP and systemic manifestations, as well as joint surgeries. Associations were also found between the -308 SNP and work disability in patients with more than 2 years of DD and radiological damage in patients with less than 10 years of DD. A borderline effect was found between the -238 SNP and HAQ score and radiological damage in patients with 2 to 10 years of DD. An association was also found between haplotypes and the SvdH score for those with more than 10 years of DD. An association was found between some TNF-α promoter SNPs and systemic manifestations, radiological progression, HAQ score, work disability, and joint surgeries, particularly in some classes of DD and between haplotypes and radiological progression for those with more than 10 years of DD. PMID:17408492

The combined therapy with chondroitin sulfate plus glucosamine sulfate or chondroitin sulfate plus glucosamine hydrochloride does not improve joint damage in an experimental model of knee osteoarthritis in rabbits.

PubMed

Roman-Blas, Jorge A; Mediero, Aránzazu; Tardío, Lidia; Portal-Nuñez, Sergio; Gratal, Paula; Herrero-Beaumont, Gabriel; Largo, Raquel

2017-01-05

Osteoarthritis is the most common chronic joint disorder especially during aging. Although with controversies, glucosamine, both in its forms of sulfate and hydrochloride, and chondroitin sulfate are commonly employed to treat osteoarthritis. Due to the modest improve in the symptoms observed in patients treated with these drugs alone, a formulation combining both agents has been considered. The discrepant results achieved for pain control or structural improvement in osteoarthritis patients has been attributed to the quality of chemical formulations or different bias in clinical studies. The current study has been designed to test the effects of two different combined formulations with adequate pharmaceutical grade of these drugs in osteoarthritic joints, and to explore the underlying mechanisms modulated by both formulations in different osteoarthritis target tissues. Knee osteoarthritis was surgically induced in experimental rabbits. Some animals received the combined therapy (CT)1, (chondroitin sulfate 1200mg/day + glucosamine sulfate 1500mg/day), or the CT2 ((chondroitin sulfate 1200mg/day + glucosamine hydrochloride 1500mg/day). Neither CT1 nor CT2 significantly modified the cartilage damage or the synovial inflammation observed in osteoarthritic animals. Treatments were also unable to modify the presence of pro-inflammatory mediators, and the synthesis of metalloproteinases in the cartilage or in the synovium of osteoarthritic animals. Combined therapies did not modify the decrease in the subchondral bone mineral density observed in osteoarthritic rabbits. Therapies of chondroitin sulfate plus glucosamine sulfate or chondroitin sulfate plus glucosamine hydrochloride failed to improve structural damage or to ameliorate the inflammatory profile of joint tissues during experimental osteoarthritis. Published by Elsevier B.V.

Baseline serum level of matrix metalloproteinase-3 as a biomarker of progressive joint damage in rheumatoid arthritis patients.

PubMed

Galil, Sahar Mahfouz Abdel; El-Shafey, Abeer Mohamed; Hagrass, Hoda A; Fawzy, Faten; Sammak, Ahmed El

2016-04-01

Matrix metalloproteinase-3 (MMP-3) plays a pivotal role in the destruction of bone and degradation of cartilage components in rheumatoid arthritis (RA). We aimed in this study to analyze the relation between baseline levels of MMP-3 and the progression of joint damage in RA. Eighty-one untreated RA patients with joint symptoms for <1 year were evaluated at baseline and after 12 months as regards erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP) and plain X-ray of both hands and wrists. Baseline levels of MMP-3 were measured by enzyme-linked immunosorbent assay and magnetic resonance imaging (MRI) of hands/wrists was performed. Disease Activity Score (DAS28) and Health Assessment Questionnaire (HAQ) were performed at baseline evaluation and after 12 months. The baseline MMP-3 levels were significantly higher in the high-progression group compared with the low-progression one (95.75 ± 42.84 vs. 50.45 ± 12.83, P < 0.001). There was a positive correlation between baseline levels of MMP-3 and MRI erosion score and other baseline clinical parameters, except for HAQ and the van der Heijde modification of the Sharp scoring system (SvdH) scores, while after 12 months, there were high positive correlations between MMP-3 and SvdH score, as well as all parameters except for ESR. Serum baseline levels of MMP-3 are strong prognostic markers of disease activity, and act well as an early predictor of progressive joint damage in recent-onset RA disease. © 2014 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Preliminary clinical report of flexible videoarthroscopy in diagnostic knee and hip arthroscopy.

PubMed

Bouaicha, Samy; Dora, Claudio; Puskas, Gabor J; Koch, Peter P; Wirth, Stephan H; Meyer, Dominik C

2012-01-01

Compared to rigid arthroscopic optics, a flexible camera system offers theoretically significant advantages: It has the potential to adapt to the naturally curved surface of joints, to move within the joint without stress to the cartilage or capsule and thereby to reduce the number of portals needed. Former studies evaluated flexible fiberoptic systems which were insufficient regarding image resolution. This is the first report on a new flexible videoendoscope with the so called "chip-on-the-tip" technology used in human joints. With a plasma sterilized 3.9 diameter flexible video endoscopy system (Visera ENF V, OLYMPUS) commonly used in diagnostic rhino-laryngoscopy, we performed preliminary testing in cadaveric knee joints. After successful feasibility testing we utilized the tool in two qualitative diagnostic knee and five hip arthroscopies in combination with conventional rigid 30° and 70° arthroscopes (STORZ). Qualitative evaluation showed superior visualisation of the posterior aspects of the knee joint as insertion of the posterior medial and lateral meniscal horn, tibial insertion of the posterior cruciate ligament and the posterolateral capsulo-ligamentous corner with acceptable image resolution and clarity compared to the rigid arthroscope. In the hip, it was possible to pass around the femoral neck, avoiding additional portals. There seemed to be virtually no risk for cartilage damage at all. Difficulties of the system were scope handling, navigation and orientation within the joint as well as potential damage to the tool itself. This is to our knowledge the first report on flexible videoarthroscopy. Some of the expectations were met, such as to reach virtually every corner the joint with minimal risk for the cartilage or other joint structures and with acceptable image quality. However, there are many significant disadvantages which question the routine use of such a videoendoscopic system with its present technical features. © 2012 – IOS Press and the authors. All rights reserved

Hand Surgery In World War II. Medical Department, United States Army,

DTIC Science & Technology

1955-09-01

Few of these patients presented deep cicatrices , latent infection was minimal, and as a rule the position of function was maintained. DEBARKATION...HOSPITAL 217 Many patients were received with large dorsal cicatrices which, although healed, were unstable. Joints and tendons not directly injured by...burns were frequently damaged by constriction and immobility because of superimposed cicatrices . Joint stiffness was likely to be even more pronounced

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paulus, Wilfred; Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor; Rahman, Irman Abdul

Lead-free solders are important material in nano and microelectronic surface mounting technology for various applications in bio medicine, environmental monitoring, spacecraft and satellite instrumentation. Nevertheless solder joint in radiation environment needs higher reliability and resistance to any damage caused by ionizing radiations. In this study a lead-free 99.0Sn0.3Ag0.7Cu wt.% (SAC) solder joint was developed and subjected to various doses of gamma radiation to investigate the effects of the ionizing radiation to micromechanical hardness of the solder. Averaged hardness of the SAC joint was obtained from nanoindentation test. The results show a relationship between hardness values of indentations and the incrementmore » of radiation dose. Highest mean hardness, 0.2290 ± 0.0270 GPa was calculated on solder joint which was exposed to 5 Gray dose of gamma radiation. This value indicates possible radiation hardening effect on irradiated solder. The hardness gradually decreased to 0.1933 ± 0.0210 GPa and 0.1631 ± 0.0173 GPa when exposed to doses 50 and 500 gray respectively. These values are also lower than the hardness of non irradiated sample which was calculated as 0.2084 ± 0.0.3633 GPa indicating possible radiation damage and needs further related atomic dislocation study.« less

Radiofrequency ablation of chondroblastoma using a multi-tined expandable electrode system: initial results.

PubMed

Tins, Bernhard; Cassar-Pullicino, Victor; McCall, Iain; Cool, Paul; Williams, David; Mangham, David

2006-04-01

The standard treatment for chondroblastoma is surgery, which can be difficult and disabling due to its apo- or epiphyseal location. Radiofrequency (RF) ablation potentially offers a minimally invasive alternative. The often large size of chondroblastomas can make treatment with plain electrode systems difficult or impossible. This article describes the preliminary experience of RF treatment of chondroblastomas with a multi-tined expandable RF electrode system. Four cases of CT guided RF treatment are described. The tumour was successfully treated in all cases. In two cases, complications occurred; infraction of a subarticular chondroblastoma in one case and cartilage and bone damage in the unaffected compartment of a knee joint in the other. Radiofrequency treatment near a joint surface threatens the integrity of cartilage and therefore long-term joint function. In weight-bearing areas, the lack of bone replacement in successfully treated lesions contributes to the risk of mechanical failure. Multi-tined expandable electrode systems allow the treatment of large chondroblastomas. In weight-bearing joints and lesions near to the articular cartilage, there is a risk of cartilage damage and mechanical weakening of the bone. In lesions without these caveats, RF ablation appears promising. The potential risks and benefits need to be evaluated for each case individually.

The International Space Station Solar Alpha Rotary Joint Anomaly Investigation

NASA Technical Reports Server (NTRS)

Harik, Elliot P.; McFatter, Justin; Sweeney, Daniel J.; Enriquez, Carlos F.; Taylor, Deneen M.; McCann, David S.

2010-01-01

The Solar Alpha Rotary Joint (SARJ) is a single-axis pointing mechanism used to orient the solar power generating arrays relative to the sun for the International Space Station (ISS). Approximately 83 days after its on-orbit installation, one of the two SARJ mechanisms aboard the ISS began to exhibit high drive motor current draw. Increased structural vibrations near the joint were also observed. Subsequent inspections via Extravehicular Activity (EVA) discovered that the nitrided case-hardened steel bearing race on the outboard side of the joint had extensive damage to one of its three rolling surfaces. A farreaching investigation of the anomaly was undertaken. The investigation included metallurgical inspections, coupon tests, traction kinematics tests, detailed bearing measurements, and thermal and structural analyses. The results of the investigation showed that the anomaly had most probably been caused by high bearing edge stresses that resulted from inadequate lubrication of the rolling contact. The profile of the roller bearings and the metallurgical properties of the race ring were also found to be significant contributing factors. To mitigate the impact of the damage, astronauts cleaned and lubricated the race ring surface with grease. This corrective action led to significantly improved performance of the mechanism both in terms of drive motor current and induced structural vibration.

The International Space Station Solar Alpha Rotary Joint Anomaly Investigation

NASA Technical Reports Server (NTRS)

Harik, Elliot P.; McFatter, Justin; Sweeney, Daniel J.; Enriquez, Carlos F.; Taylor, Deneen M.; McCann, David S.

2010-01-01

The Solar Alpha Rotary Joint (SARJ) is a single-axis pointing mechanism used to orient the solar power generating arrays relative to the sun for the International Space Station (ISS). Approximately 83 days after its on-orbit installation, one of the two SARJ mechanisms aboard the ISS began to exhibit high drive motor current draw. Increased structural vibrations near the joint were also observed. Subsequent inspections via Extravehicular Activity (EVA) discovered that the nitrided case hardened steel bearing race on the outboard side of the joint had extensive damage to one of its three rolling surfaces. A far-reaching investigation of the anomaly was undertaken. The investigation included metallurgical inspections, coupon tests, traction kinematics tests, detailed bearing measurements, and thermal and structural analyses. The results of the investigation showed that anomaly had most probably been caused by high bearing edge stresses that resulted from inadequate lubrication of the rolling contact. The profile of the roller bearings and the metallurgical properties of the race ring were also found to be significant contributing factors. To mitigate the impact of the damage astronauts cleaned and lubricated the race ring surface with grease. This corrective action led to significantly improved performance of the mechanism both in terms of drive motor current and induced structural vibration.

Tibial tuberosity to trochlear groove distance and its association with patellofemoral osteoarthritis-related structural damage worsening: data from the osteoarthritis initiative.

PubMed

Haj-Mirzaian, Arya; Guermazi, Ali; Hakky, Michael; Sereni, Christopher; Zikria, Bashir; Roemer, Frank W; Tanaka, Miho J; Cosgarea, Andrew J; Demehri, Shadpour

2018-04-30

To determine whether the tibial tuberosity-to-trochlear groove (TT-TG) distance is associated with concurrent patellofemoral joint osteoarthritis (OA)-related structural damage and its worsening on 24-month follow-up magnetic resonance imaging (MRI) in participants in the Osteoarthritis Initiative (OAI). Six hundred subjects (one index knee per participant) were assessed. To evaluate patellofemoral OA-related structural damage, baseline and 24-month semiquantitative MRI Osteoarthritis Knee Score (MOAKS) variables for cartilage defects, bone marrow lesions (BMLs), osteophytes, effusion, and synovitis were extracted from available readings. The TT-TG distance was measured in all subjects using baseline MRIs by two musculoskeletal radiologists. The associations between baseline TT-TG distance and concurrent baseline MOAKS variables and their worsening in follow-up MRI were investigated using regression analysis adjusted for variables associated with tibiofemoral and patellofemoral OA. At baseline, increased TT-TG distance was associated with concurrent lateral patellar and trochlear cartilage damages, BML, osteophytes, and knee joint effusion [cross-sectional evaluations; overall odds ratio 95% confidence interval (OR 95% CI): 1.098 (1.045-1.154), p < 0.001]. In the longitudinal analysis, increased TT-TG distance was significantly related to lateral patellar and trochlear cartilage, BML, and joint effusion worsening (overall OR 95% CI: 1.111 (1.056-1.170), p < 0.001). TT-TG distance was associated with simultaneous lateral patellofemoral OA-related structural damage and its worsening over 24 months. Abnormally lateralized tibial tuberosity may be considered as a risk factor for future patellofemoral OA worsening. • Excessive TT-TG distance on MRI is an indicator/predictor of lateral-patellofemoral-OA. • TT-TG is associated with simultaneous lateral-patellofemoral-OA (6-17% chance-increase for each millimeter increase). • TT-TG is associated with longitudinal (24-months) lateral-patellofemoral-OA (5-15% chance-increase for each millimeter).

Damage Progression in Bolted Composites

NASA Technical Reports Server (NTRS)

Minnetyan, Levon; Chamis, Christos C.; Gotsis, Pascal K.

1998-01-01

Structural durability, damage tolerance, and progressive fracture characteristics of bolted graphite/epoxy composite laminates are evaluated via computational simulation. Constituent material properties and stress and strain limits are scaled up to the structure level to evaluate the overall damage and fracture propagation for bolted composites. Single and double bolted composite specimens with various widths and bolt spacings are evaluated. The effect of bolt spacing is investigated with regard to the structural durability of a bolted joint. Damage initiation, growth, accumulation, and propagation to fracture are included in the simulations. Results show the damage progression sequence and structural fracture resistance during different degradation stages. A procedure is outlined for the use of computational simulation data in the assessment of damage tolerance, determination of sensitive parameters affecting fracture, and interpretation of experimental results with insight for design decisions.

Damage Progression in Bolted Composites

NASA Technical Reports Server (NTRS)

Minnetyan, Levon; Chamis, Christos; Gotsis, Pascal K.

1998-01-01

Structural durability,damage tolerance,and progressive fracture characteristics of bolted graphite/epoxy composite laminates are evaluated via computational simulation. Constituent material properties and stress and strain limits are scaled up to the structure level to evaluate the overall damage and fracture propagation for bolted composites. Single and double bolted composite specimens with various widths and bolt spacings are evaluated. The effect of bolt spacing is investigated with regard to the structural durability of a bolted joint. Damage initiation, growth, accumulation, and propagation to fracture are included in the simulations. Results show the damage progression sequence and structural fracture resistance during different degradation stages. A procedure is outlined for the use of computational simulation data in the assessment of damage tolerance, determination of sensitive parameters affecting fracture, and interpretation of experimental results with insight for design decisions.

ACEE composite structures technology

NASA Technical Reports Server (NTRS)

Klotzsche, M. (Compiler)

1984-01-01

The NASA Aircraft Energy Efficiency (ACEE) Composite Primary Aircraft Structures Program has made significant progress in the development of technology for advanced composites in commercial aircraft. Commercial airframe manufacturers have demonstrated technology readiness and cost effectiveness of advanced composites for secondary and medium primary components and have initiated a concerted program to develop the data base required for efficient application to safety-of-flight wing and fuselage structures. Oral presentations were compiled into five papers. Topics addressed include: damage tolerance and failsafe testing of composite vertical stabilizer; optimization of composite multi-row bolted joints; large wing joint demonstation components; and joints and cutouts in fuselage structure.

Lamb Wave-Based Structural Health Monitoring on Composite Bolted Joints under Tensile Load

PubMed Central

Yang, Bin; Xuan, Fu-Zhen; Xiang, Yanxun; Li, Dan; Zhu, Wujun; Tang, Xiaojun; Xu, Jichao; Yang, Kang; Luo, Chengqiang

2017-01-01

Online and offline monitoring of composite bolted joints under tensile load were investigated using piezoelectric transducers. The relationships between Lamb wave signals, pre-tightening force, the applied tensile load, as well as the failure modes were investigated. Results indicated that S0/A0 wave amplitudes decrease with the increasing of load. Relationships between damage features and S0/A0 mode were built based on the finite element (FE) simulation and experimental results. The possibility of application of Lamb wave-based structure health monitoring in bolted joint-like composite structures was thus achieved. PMID:28773014

Camera Based Closed Loop Control for Partial Penetration Welding of Overlap Joints

NASA Astrophysics Data System (ADS)

Abt, F.; Heider, A.; Weber, R.; Graf, T.; Blug, A.; Carl, D.; Höfler, H.; Nicolosi, L.; Tetzlaff, R.

Welding of overlap joints with partial penetration in automotive applications is a challenging process, since the laser power must be set very precisely to achieve a proper connection between the two joining partners without damaging the backside of the sheet stack. Even minor changes in welding conditions can lead to bad results. To overcome this problem a camera based closed loop control for partial penetration welding of overlap joints was developed. With this closed loop control it is possible to weld such configurations with a stable process result even under changing welding conditions.

Fatigue failure of pb-free electronic packages under random vibration loads

NASA Astrophysics Data System (ADS)

Saravanan, S.; Prabhu, S.; Muthukumar, R.; Gowtham Raj, S.; Arun Veerabagu, S.

2018-03-01

The electronic equipment are used in several fields like, automotive, aerospace, consumer goods where they are subjected to vibration loads leading to failure of solder joints used in these equipment. This paper presents a methodology to predict the fatigue life of Pb-free surface mounted BGA packages subjected to random vibrations. The dynamic characteristics of the PCB, such as the natural frequencies, mode shapes and damping ratios were determined. Spectrum analysis was used to determine the stress response of the critical solder joint and the cumulative fatigue damage accumulated by the solder joint for a specific duration was determined.

Osteoprotegerin reduces the development of pain behaviour and joint pathology in a model of osteoarthritis

PubMed Central

Sagar, Devi Rani; Ashraf, Sadaf; Xu, Luting; Burston, James J; Menhinick, Matthew R; Poulter, Caroline L; Bennett, Andrew J; Walsh, David A; Chapman, Victoria

2014-01-01

Background Increased subchondral bone turnover may contribute to pain in osteoarthritis (OA). Objectives To investigate the analgesic potential of a modified version of osteoprotegerin (osteoprotegerin-Fc (OPG-Fc)) in the monosodium iodoacetate (MIA) model of OA pain. Methods Male Sprague Dawley rats (140–260 g) were treated with either OPG-Fc (3 mg/kg, subcutaneously) or vehicle (phosphate-buffered saline) between days 1 and 27 (pre-emptive treatment) or days 21 and 27 (therapeutic treatment) after an intra-articular injection of MIA (1 mg/50 µl) or saline. A separate cohort of rats received the bisphosphonate zoledronate (100 µg/kg, subcutaneously) between days 1 and 25 post-MIA injection. Incapacitance testing and von Frey (1–15 g) hind paw withdrawal thresholds were used to assess pain behaviour. At the end of the study, rats were killed and the knee joints and spinal cord removed for analysis. Immunohistochemical studies using Iba-1 and GFAP quantified levels of activation of spinal microglia and astrocytes, respectively. Joint sections were stained with haematoxylin and eosin or Safranin-O fast green and scored for matrix proteoglycan and overall joint morphology. The numbers of tartrate-resistant acid phosphatase-positive osteoclasts were quantified. N=10 rats/group. Results Pre-emptive treatment with OPG-Fc significantly attenuated the development of MIA-induced changes in weightbearing, but not allodynia. OPG-Fc decreased osteoclast number, inhibited the formation of osteophytes and improved structural pathology within the joint similarly to the decrease seen after pretreatment with the bisphosphonate, zoledronate. Therapeutic treatment with OPG-Fc decreased pain behaviour, but did not improve pathology in rats with established joint damage. Conclusions Our data suggest that early targeting of osteoclasts may reduce pain associated with OA. PMID:23723320

Three-Dimensional Biomechanical Analysis of Rearfoot and Forefoot Running

PubMed Central

Knorz, Sebastian; Kluge, Felix; Gelse, Kolja; Schulz-Drost, Stefan; Hotfiel, Thilo; Lochmann, Matthias; Eskofier, Björn; Krinner, Sebastian

2017-01-01

Background: In the running community, a forefoot strike (FFS) pattern is increasingly preferred compared with a rearfoot strike (RFS) pattern. However, it has not been fully understood which strike pattern may better reduce adverse joint forces within the different joints of the lower extremity. Purpose: To analyze the 3-dimensional (3D) stress pattern in the ankle, knee, and hip joint in runners with either a FFS or RFS pattern. Study Design: Descriptive laboratory study. Methods: In 22 runners (11 habitual rearfoot strikers, 11 habitual forefoot strikers), RFS and FFS patterns were compared at 3.0 m/s (6.7 mph) on a treadmill with integrated force plates and a 3D motion capture analysis system. This combined analysis allowed characterization of the 3D biomechanical forces differentiated for the ankle, knee, and hip joint. The maximum peak force (MPF) and maximum loading rate (LR) were determined in their 3 ordinal components: vertical, anterior-posterior (AP), and medial-lateral (ML). Results: For both strike patterns, the vertical components of the MPF and LR were significantly greater than their AP or ML components. In the vertical axis, FFS was generally associated with a greater MPF but significantly lower LR in all 3 joints. The AP components of MPF and LR were significantly lower for FFS in the knee joint but significantly greater in the ankle and hip joints. The ML components of MPF and LR tended to be greater for FFS but mostly did not reach a level of significance. Conclusion: FFS and RFS were associated with different 3D stress patterns in the ankle, knee, and hip joint, although there was no global advantage of one strike pattern over the other. The multimodal individual assessment for the different anatomic regions demonstrated that FFS seems favorable for patients with unstable knee joints in the AP axis and RFS may be recommended for runners with unstable ankle joints. Clinical Relevance: Different strike patterns show different 3D stress in joints of the lower extremity. Due to either rehabilitation after injuries or training in running sports, rearfoot or forefoot running should be preferred to prevent further damage or injuries caused by inadequate biomechanical load. Runners with a history of knee joint injuries may benefit from FFS whereas RFS may be favorable for runners with a history of ankle joint injuries. PMID:28812039

Gas-tungsten arc welding of aluminum alloys

DOEpatents

Frye, Lowell D.

1984-01-01

A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

Elbow Pain

MedlinePlus

... tear damage than are many other joints. Seek emergency care if you have: An obvious deformity in ... http://www.mayoclinic.org/symptoms/elbow-pain/basics/definition/SYM-20050874 . Mayo Clinic Footer Legal Conditions and ...

Rationale for a randomized controlled trial comparing two prophylaxis regimens in adults with severe hemophilia A: the Hemophilia Adult Prophylaxis Trial

PubMed Central

Ragni, Margaret V

2011-01-01

A major goal of comprehensive hemophilia care is to prevent occurrence of bleeds by prophylaxis or regular preventive factor, one or more times weekly. Although prophylaxis is effective in reducing bleeding and joint damage in children, whether it is necessary to continue into adulthood is not known. The purpose of this article is to describe a Phase III randomized controlled trial to evaluate prophylaxis comparing two dose regimens in adults with severe hemophilia A. I hypothesize that adults with mature cartilage and joints are less susceptible to joint bleeds and joint damage, and that once-weekly recombinant factor VIII prophylaxis, with up to two rescue doses per week, is as effective as thrice-weekly prophylaxis in reducing bleeding frequency, but less costly and more acceptable, with higher quality of life. The ultimate goal of this project is to determine whether once-weekly prophylaxis is any worse than thrice-weekly prophylaxis in reducing joint bleeding frequency, while potentially utilizing less factor, at lower cost, leading to a better quality of life. This is an innovative concept, as it challenges the current paradigm of thrice-weekly prophylaxis in adults, which is based on dosing in children. Furthermore, this trial will assess interdose thrombin generation, a novel tissue factor-based assay of hemostasis, to determine if individualized thrombin generation can predict more individualized prophylaxis dosing, which would be practice changing. PMID:21939418

Antioxidant response of soybean seedlings to joint stress of lanthanum and acid rain.

PubMed

Liang, Chanjuan; Wang, Weimin

2013-11-01

Excess of rare earth elements in soil can be a serious environmental stress on plants, in particular when acid rain coexists. To understand how such a stress affects plants, we studied antioxidant response of soybean leaves and roots exposed to lanthanum (0.06, 0.18, and 0.85 mmol L(-1)) under acid rain conditions (pH 4.5 and 3.0). We found that low concentration of La3+ (0.06 mmol L(-1)) did not affect the activity of antioxidant enzymes (catalase and peroxidase) whereas high concentration of La3+ (≥0.18 mmol L(-1)) did. Compared to treatment with acid rain (pH 4.5 and pH 3.0) or La3+ alone, joint stress of La3+ and acid rain affected more severely the activity of catalase and peroxidase, and induced more H2O2 accumulation and lipid peroxidation. When treated with high level of La3+ (0.85 mmol L(-1)) alone or with acid rain (pH 4.5 and 3.0), roots were more affected than leaves regarding the inhibition of antioxidant enzymes, physiological function, and growth. The severity of oxidative damage and inhibition of growth caused by the joint stress associated positively with La3+ concentration and soil acidity. These results will help us understand plant response to joint stress, recognize the adverse environmental impact of rare earth elements in acidic soil, and develop measures to eliminate damage caused by such joint stress.

The effect of nonablative laser energy on joint capsular properties. An in vitro histologic and biochemical study using a rabbit model

NASA Technical Reports Server (NTRS)

Hayashi, K.; Thabit, G. 3rd; Vailas, A. C.; Bogdanske, J. J.; Cooley, A. J.; Markel, M. D.

1996-01-01

The purpose of this study was to evaluate the effect of laser energy at nonablative levels on joint capsular histologic and biochemical properties in an in vitro rabbit model. The medial and lateral portions of the femoropatellar joint capsule from both stifles of 12 mature New Zealand White rabbits were used. Specimens were divided into three treatment groups (5 watts, 10 watts, and 15 watt) and one control group using a randomized block design. Specimens were placed in a 37 degrees bath of lactated Ringer's solution and laser energy was applied using a holmium:yttrium-aluminum-garnet laser in four transverse passes across the tissue at a velocity of 2 mm/sec with the handpiece set 1.5 mm from the synovial surface. Histologic analysis revealed thermal alteration of collagen (fusion) and fibroblasts (pyknosis) at all energy densities, with higher laser energy causing significantly greater morphologic changes over a larger area (P < 0.05). Application of laser energy did not significantly alter the biochemical parameters evaluated, including type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I Collagen content and nonreducible corsslinks were not significantly altered.

Experimental studies of glued Aluminum-glass joints

NASA Astrophysics Data System (ADS)

Ligaj, B.; Wirwicki, M.; Karolewska, K.; Jasińska, A.

2018-04-01

Glued steel-glass or aluminum-glass joints are to be found, among other things, in vehicles (cars, buses, trains, trams) as windscreen assembly pieces for the supporting structure. For the purposes of the experiments, samples were made in which the top beam was made of the AW-2017A aluminum alloy and the bottom beam was made of thermally reinforced soda-lime glass whereas the glued joints were made of one-component polyurethane glue Körapur 175. The tests were performed under four-point bending conditions at monotonic incremental bending moment values on the Instron 5965 durability machine. The experimental study of the durability of glued joints under four-point bending conditions with the monotonic incremental bending moment allows to determine the values of stresses, whose value is related to initiation of damage of the tested joint.

Design, Fabrication and Characterization of High Temperature Joints in Ceramic Composites

NASA Technical Reports Server (NTRS)

Singh, M.

1999-01-01

Ceramic joining has been recognized as one of the enabling technologies for the successful utilization of ceramic components in a number of demanding, high temperature applications. Various joint design philosophies and design issues have been discussed along with an affordable, robust ceramic joining technology (ARCJoinT). A wide variety of silicon carbide-based composite materials, in different shapes and sizes, have been joined using this technology. This technique is capable of producing joints with tailorable thickness and composition. The room and high temperature mechanical properties and fractography of ceramic joints have been reported. These joints maintain their mechanical strength up to 1200 C in air. This technology is suitable for the joining of large and complex shaped ceramic composite components and with certain modifications, can be applied to repair of ceramic components damaged in service.

Design, Fabrication, and Characterization of High Temperature Joints in Ceramic Composites

NASA Technical Reports Server (NTRS)

Singh, M.

1999-01-01

Ceramic joining has been recognized as one of the enabling technologies for the successful utilization of ceramic components in a number of demanding, high temperature applications. Various joint design philosophies and design issues have been discussed along with an affordable, robust ceramic joining technology (ARCJoinT). A wide variety of silicon carbide-based composite materials, in different shapes and sizes, have been joined using this technology. This technique is capable of producing joints with tailorable thickness and composition. The room and high temperature mechanical properties and fractography of ceramic joints have been reported. These joints maintain their mechanical strength up to 1200C in air. This technology is suitable for the joining of large and complex shaped ceramic composite components and with certain modifications, can be applied to repair of ceramic components damaged in service.

Autoinflammatory Diseases

MedlinePlus

... damage. Vision loss. Hearing loss. Mental retardation. Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS) is associated ... red spots on the skin caused by burst blood vessels (purpura). Joint pain. Permanent shortening of a muscle ...

Reliability aspects of a composite bolted scarf joint. [in wing skin splice

NASA Technical Reports Server (NTRS)

Reed, D. L.; Eisenmann, J. R.

1975-01-01

The design, fabrication, static test, and fatigue test of both tension and compression graphite-epoxy candidates for a wing splice representative of a next-generation transport aircraft was the objective of the reported research program. A single-scarf bolted joint was selected as the design concept. Test specimens were designed and fabricated to represent an upper-surface and a lower-surface panel containing the splice. The load spectrum was a flight-by-flight random-load history including ground-air-ground loads. The results of the fatigue testing indicate that, for this type of joint, the inherent fatigue resistance of the laminate is reflected in the joint behavior and, consequently, the rate of damage accumulation is very slow under realistic fatigue loadings.

Patterned CoCrMo and Al2 O3 surfaces for reduced free wear debris in artificial joint arthroplasty.

PubMed

Tarabolsi, Mohamad; Klassen, Thomas; Mantwill, Frank; Gärtner, Frank; Siegel, Frank; Schulz, Arndt-Peter

2013-12-01

Surface wear of corresponding tribological pairings is still a major problem in the application of artificial joint surgery. This study aims at developing wear reduced surfaces to utilize them in total joint arthroplasty. Using a pico-second laser, samples of medical CoCrMo metal alloy and Al2 O3 ceramic were patterned by laser material removal. The subsequent tribological investigations employed a ring-on-disc method. The results showed that those samples with modified surfaces show less mass or volume loss than those with a regular, smooth surface. Using calf serum as lubricating medium, the volume loss of the structured CoCrMo samples was eight times lower than that of regular samples. By structuring Al2 O3 surfaces, the wear volume could be reduced by 4.5 times. The results demonstrate that defined surface channels or pits enable the local sedimentation of wear debris. Thus, the amount of free debris could be reduced. Fewer abrasives in the lubricated so-called three-body-wear between the contact surfaces should result in less surface damage. Apart from direct influences on the wear behavior, less amounts of free debris of artificial joints should also be beneficial for avoiding undesired reactions with the surrounding soft tissues. The results from this study are very promising. Future investigations should involve the use of simulators meeting the natural conditions in the joint and in vivo studies with living organisms. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

High‐resolution ultrasonography of the first metatarsal phalangeal joint in gout: a controlled study

PubMed Central

Wright, Stephen A; Filippucci, Emilio; McVeigh, Claire; Grey, Arthur; McCarron, Maura; Grassi, Walter; Wright, Gary D; Taggart, Allister J

2007-01-01

Objective To compare high‐resolution ultrasound (HRUS) with conventional radiography in the detection of erosions in the first metatarsophalangeal joints (1st MTPJs) of patients with gout and to identify the characteristic sonographic features of gout. Methods HRUS examination of the 1st MTPJs of both feet was performed by two independent sonographers. The presence of joint and soft‐tissue pathology was recorded. x Ray examination of the feet was performed on the same day and reported by the same radiologist. Results 39 male patients with gout and 22 age‐matched control subjects (14 with an inflammatory arthropathy and 8 disease free) were studied. The agreement on erosion between HRUS and x ray was poor, κ = 0.229 (non‐weighted), with McNemar's test being significant (p<0.001) indicating a large number of false negative x rays. 22 MTPJs in patients with gout had never been subjected to a clinical attack of acute gout. In these MTPJs, there were 10 erosions detected by HRUS and 3 erosions on x ray. HRUS features significantly more prevalent in the patients with gout were hard and soft tophus‐like lesions (p<0.01) and the double contour sign (p<0.01). Conclusions These data show that HRUS may assist in the management of gout in two ways: first, by aiding in the diagnosis by identifying the sonographic features that may be representative of the disease, and, second, by allowing the early detection of erosive joint damage and/or tophaceous deposits even in clinically silent joints. PMID:17185326

Histopomorphic Evaluation of Radiofrequency Mediated Débridement Chondroplasty

PubMed Central

Ganguly, Kumkum; McRury, Ian D; Goodwin, Peter M; Morgan, Roy E; Augé II, Wayne K

2010-01-01

The use of radiofrequency devices has become widespread for surgical ablation procedures. When ablation devices have been deployed in treatment settings requiring tissue preservation like débridement chondroplasty, adoption has been limited due to the collateral damage caused by these devices in healthy tissue surrounding the treatment site. Ex vivo radiofrequency mediated débridement chondroplasty was performed on osteochondral specimens demonstrating surface fibrillation obtained from patients undergoing knee total joint replacement. Three radiofrequency systems designed to perform débridement chondroplasty were tested each demonstrating different energy delivery methods: monopolar ablation, bipolar ablation, and non-ablation energy. Treatment outcomes were compared with control specimens as to clinical endpoint and histopomorphic characteristics. Fibrillated cartilage was removed in all specimens; however, the residual tissue remaining at the treatment site displayed significantly different characteristics attributable to radiofrequency energy delivery method. Systems that delivered ablation-based energies caused tissue necrosis and collateral damage at the treatment site including corruption of cartilage Superficial and Transitional Zones; whereas, the non-ablation system created a smooth articular surface with Superficial Zone maintenance and without chondrocyte death or tissue necrosis. The mechanism of radiofrequency energy deposition upon tissues is particularly important in treatment settings requiring tissue preservation. Ablation-based device systems can cause a worsened state of articular cartilage from that of pre-treatment. Non-ablation energy can be successful in modifying/preconditioning tissue during débridement chondroplasty without causing collateral damage. Utilizing a non-ablation radiofrequency system provides the ability to perform successful débridement chondroplasty without causing additional articular cartilage tissue damage and may allow for other cartilage intervention success. PMID:20721322

Novel Ultrasound Joint Selection Methods Using a Reduced Joint Number Demonstrate Inflammatory Improvement when Compared to Existing Methods and Disease Activity Score at 28 Joints.

PubMed

Tan, York Kiat; Allen, John C; Lye, Weng Kit; Conaghan, Philip G; D'Agostino, Maria Antonietta; Chew, Li-Ching; Thumboo, Julian

2016-01-01

A pilot study testing novel ultrasound (US) joint-selection methods in rheumatoid arthritis. Responsiveness of novel [individualized US (IUS) and individualized composite US (ICUS)] methods were compared with existing US methods and the Disease Activity Score at 28 joints (DAS28) for 12 patients followed for 3 months. IUS selected up to 7 and 12 most ultrasonographically inflamed joints, while ICUS additionally incorporated clinically symptomatic joints. The existing, IUS, and ICUS methods' standardized response means were -0.39, -1.08, and -1.11, respectively, for 7 joints; -0.49, -1.00, and -1.16, respectively, for 12 joints; and -0.94 for DAS28. Novel methods effectively demonstrate inflammatory improvement when compared with existing methods and DAS28.

Roller Testing to Mimic Damage of the ISS SARJ Ring and Durability Test to Simulate Fifteen Years of SARJ Operation Using the Damaged Surface

NASA Technical Reports Server (NTRS)

Krantz, Timothy L.; Elchert, Justin P.; DellaCorte, Christopher; Dube, Michael J.

2016-01-01

The International Space Station's starboard Solar Alpha Rotary Joint (SARJ) experienced a breakdown of the joint's race ring surface. The starboard SARJ mechanism was cleaned and lubricated with grease. To provide some guidance on the expected behavior of the damaged SARJ ring with continued operations, experiments were conducted using rollers and a vacuum roller test rig. The approach of the experimental work involved three main steps: (1) initiate damage using conditions representative of the SARJ with inadequate lubrication; (2) propagate the damage by operating the test rollers without lubrication; and (3) assess the durability of the roller by testing to simulate the equivalent of 15 years of SARJ operation on the damaged surface assuming adequate grease lubrication. During the rig testing, additional and/or replacement grease was introduced at regular intervals to maintain good lubrication in the rig. The damage to the nitride layer continued even after application of grease. The grease lubrication proved to be effective for limiting the value of the axial force that can be developed. Limiting the axial force on the SARJ mechanism is important since the larger the axial force the more concentrated the load pressure becomes on the blend-radius location on the SARJ roller. After the testing simulating 15 years of SARJ operations, the wear depths were the order of 0.2 mm for the nitrided 15-5 roller and the order of 0.06 mm for the mating 440C roller. Metallographic inspections were done to search for indications of impending fatigue or other fracture indications that might eventually propagate and cause structural failure. There were no indications or features found that could eventually compromise structural integrity.

Characterization of cartilage defects detected by MRI in Kellgren-Lawrence grade 0 or 1 knees.

PubMed

Taguchi, Kenji; Chiba, Ko; Okazaki, Narihiro; Kido, Yasuo; Miyamoto, Takashi; Yonekura, Akihiko; Tomita, Masato; Uetani, Masataka; Osaki, Makoto

2017-09-01

Osteoarthritis of the knee is generally evaluated by plain X-rays, which are incapable of detecting small cartilage damage. There are some patients who have small cartilage defects on MRI with no abnormal findings on plain X-rays. In this study, the prevalence and regional characteristics of cartilage defects detected by MRI were studied in cases with normal X-ray findings (Kellgren-Lawrence grade 0 and 1). Relationships between the cartilage defects and OA risk factors such as obesity and leg alignment were also investigated. A total of 51 knees of Kellgren-Lawrence grade 0 or 1 without knee joint pain were included. Fat-suppressed spoiled-gradient recalled (SPGR) sagittal images were scanned by 3 T MRI, and the presence of cartilage damage was confirmed. Cartilage damage was visualized three-dimensionally, and its location and morphology were analyzed. On a full length standing radiograph of the lower extremities, leg alignment and other parameters were measured, and their associations with cartilage damage were analyzed. Cartilage defects were detected in 26% of women aged >50 years. Cartilage damage was located on the medial femoral condyle near the intercondylar notch, and was mostly elliptically shaped in the anteroposterior direction. Subjects with damaged cartilage were not obese and did not have abnormal leg alignment. It should be borne in mind that some elderly women may have damaged cartilage on the intercondylar notch side of the medial joint, even though plain X-rays appear normal, and this cannot be predicted by obesity or leg alignment. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Prednisone

MedlinePlus

... improves when the drug is decreased or discontinued. Avascular Necrosis of Bone For reasons that are not known, ... joint damage, most often of the hips. In avascular necrosis (or osteonecrosis, meaning “bone death”) of the hip, ...

Abatacept Injection

MedlinePlus

... with daily activities, and joint damage caused by rheumatoid arthritis (a condition in which the body attacks its ... that fight infection). People who have had severe rheumatoid arthritis for a long time may have a greater ...

Quantitative versus semiquantitative MR imaging of cartilage in blood-induced arthritic ankles: preliminary findings.

PubMed

Doria, Andrea S; Zhang, Ningning; Lundin, Bjorn; Hilliard, Pamela; Man, Carina; Weiss, Ruth; Detzler, Gary; Blanchette, Victor; Moineddin, Rahim; Eckstein, Felix; Sussman, Marshall S

2014-05-01

Recent advances in hemophilia prophylaxis have raised the need for accurate noninvasive methods for assessment of early cartilage damage in maturing joints to guide initiation of prophylaxis. Such methods can either be semiquantitative or quantitative. Whereas semiquantitative scores are less time-consuming to be performed than quantitative methods, they are prone to subjective interpretation. To test the feasibility of a manual segmentation and a quantitative methodology for cross-sectional evaluation of articular cartilage status in growing ankles of children with blood-induced arthritis, as compared with a semiquantitative scoring system and clinical-radiographic constructs. Twelve boys, 11 with hemophilia (A, n = 9; B, n = 2) and 1 with von Willebrand disease (median age: 13; range: 6-17), underwent physical examination and MRI at 1.5 T. Two radiologists semiquantitatively scored the MRIs for cartilage pathology (surface erosions, cartilage loss) with blinding to clinical information. An experienced operator applied a validated quantitative 3-D MRI method to determine the percentage area of denuded bone (dAB) and the cartilage thickness (ThCtAB) in the joints' MRIs. Quantitative and semiquantitative MRI methods and clinical-radiographic constructs (Hemophilia Joint Health Score [HJHS], Pettersson radiograph scores) were compared. Moderate correlations were noted between erosions and dAB (r = 0.62, P = 0.03) in the talus but not in the distal tibia (P > 0.05). Whereas substantial to high correlations (r range: 0.70-0.94, P < 0.05) were observed between erosions, cartilage loss, HJHS and Pettersson scores both at the distal tibia and talus levels, moderate/borderline substantial (r range: 0.55-0.61, P < 0.05) correlations were noted between dAB/ThCtAB and clinical-radiographic constructs. Whereas the semiquantitative method of assessing cartilage status is closely associated with clinical-radiographic scores in cross-sectional studies of blood-induced arthropathy, quantitative measures provide independent information and are therefore less applicable for that research design.

The anterolateral ligament (ALL) and its role in rotational extra-articular stability of the knee joint: a review of anatomy and surgical concepts.

PubMed

Roessler, Philip P; Schüttler, Karl F; Heyse, Thomas J; Wirtz, Dieter C; Efe, Turgay

2016-03-01

The anterolateral ligament of the knee (ALL) has caused a lot of rumors in orthopaedics these days. The structure that was first described by Segond back in 1879 has experienced a long history of anatomic descriptions and speculations until its rediscovery by Claes in 2013. Its biomechanical properties and function have been examined recently, but are not yet fully understood. While the structure seems to act as a limiter of internal rotation and lateral meniscal extrusion its possible proprioceptive effect remains questionable. Its contribution to the pivot shift phenomenon has been uncovered in parts, therefore it has been recognized that a concomitant anterolateral stabilization together with ACL reconstruction may aid in prevention of postoperative instability after severe ligamentous knee damages. However, there are a lot of different methods to perform this procedure and the clinical outcome has yet to be examined. This concise review will give an overview on the present literature to outline the long history of the ALL under its different names, its anatomic variances and topography as well as on histologic examinations, imaging modalities, arthroscopic aspects and methods for a possible anterolateral stabilization of the knee joint.

Balloon osteoplasty--a new technique for reduction and stabilisation of impression fractures in the tibial plateau: a cadaver study and first clinical application.

PubMed

Ahrens, Philipp; Sandmann, Gunther; Bauer, Jan; König, Benjamin; Martetschläger, Frank; Müller, Dirk; Siebenlist, Sebastian; Kirchhoff, Chlodwig; Neumaier, Markus; Biberthaler, Peter; Stöckle, Ulrich; Freude, Thomas

2012-09-01

Fractures of the tibial plateau are among the most severe injuries of the knee joint and lead to advanced gonarthrosis if the reduction does not restore perfect joint congruency. Many different reduction techniques focusing on open surgical procedures have been described in the past. In this context we would like to introduce a novel technique which was first tested in a cadaver setup and has undergone its successful first clinical application. Since kyphoplasty demonstrated effective ways of anatomical correction in spine fractures, we adapted the inflatable instruments and used the balloon technique to reduce depressed fragments of the tibial plateau. The technique enabled us to restore a congruent cartilage surface and bone reduction. In this technique we see a useful new method to reduce depressed fractures of the tibial plateau with the advantages of low collateral damage as it is known from minimally invasive procedures.

Spider Silk Spun and Integrated into Composites

DTIC Science & Technology

2009-02-20

and elongation of sericin is lower than those of fibroin and, finally, (0 local shear damage is dominant in damaged sericin between fibres, while the... sericin at fibre-joint often shows microflow. These analytical studies are presently being expanded to include synthetic composites made of both...with sericin . Such a cocoon consists of three main parts: an outermost loose mesh structure, the middle shell layers and the innermost tetelette; all

Electromigration Failure Mechanism in Sn-Cu Solder Alloys with OSP Cu Surface Finish

NASA Astrophysics Data System (ADS)

Chu, Ming-Hui; Liang, S. W.; Chen, Chih; Huang, Annie T.

2012-09-01

Organic solderable preservative (OSP) has been adopted as the Cu substrate surface finish in flip-chip solder joints for many years. In this study, the electromigration behavior of lead-free Sn-Cu solder alloys with thin-film under bump metallization and OSP surface finish was investigated. The results showed that severe damage occurred on the substrate side (cathode side), whereas the damage on the chip side (cathode side) was not severe. The damage on the substrate side included void formation, copper dissolution, and formation of intermetallic compounds (IMCs). The OSP Cu interface on the substrate side became the weakest point in the solder joint even when thin-film metallization was used on the chip side. Three-dimensional simulations were employed to investigate the current density distribution in the area between the OSP Cu surface finish and the solder. The results indicated that the current density was higher along the periphery of the bonding area between the solder and the Cu pad, consistent with the area of IMC and void formation in our experimental results.

In-field implementation of impedance-based structural health monitoring for insulated rail joints

NASA Astrophysics Data System (ADS)

Albakri, Mohammad I.; Malladi, V. V. N. Sriram; Woolard, Americo G.; Tarazaga, Pablo A.

2017-04-01

Track defects are a major safety concern for the railroad industry. Among different track components, insulated rail joints, which are widely used for signaling purposes, are considered a weak link in the railroad track. Several joint-related defects have been identified by the railroad community, including rail wear, torque loss, and joint bar breakage. Current track inspection techniques rely on manual and visual inspection or on specially equipped testing carts, which are costly, timeconsuming, traffic disturbing, and prone to human error. To overcome the aforementioned limitations, the feasibility of utilizing impedance-based structural health monitoring for insulated rail joints is investigated in this work. For this purpose, an insulated joint, provided by Koppers Inc., is instrumented with piezoelectric transducers and assembled with 136 AREA rail plugs. The instrumented joint is then installed and tested at the Facility for Accelerated Service Testing, Transportation Technology Center Inc. The effects of environmental and operating conditions on the measured impedance signatures are investigated through a set of experiments conducted at different temperatures and loading conditions. The capabilities of impedance-based SHM to detect several joint-related damage types are also studied by introducing reversible mechanical defects to different joint components.

Numerical Investigation of the Dynamic Properties of Intermittent Jointed Rock Models Subjected to Cyclic Uniaxial Compression

NASA Astrophysics Data System (ADS)

Liu, Yi; Dai, Feng; Zhao, Tao; Xu, Nu-wen

2017-01-01

Intermittent jointed rocks, which exist in a myriad of engineering projects, are extraordinarily susceptible to cyclic loadings. Understanding the dynamic fatigue properties of jointed rocks is necessary for evaluating the stability of rock engineering structures. This study numerically investigated the influences of cyclic loading conditions (i.e., frequency, maximum stress and amplitude) and joint geometric configurations (i.e., dip angle, persistency and interspace) on the dynamic fatigue mechanisms of jointed rock models. A reduction model of stiffness and strength was first proposed, and then, sixteen cyclic uniaxial loading tests with distinct loading parameters and joint geometries were simulated. Our results indicate that the reduction model can effectively reproduce the hysteresis loops and the accumulative plastic deformation of jointed rocks in the cyclic process. Both the loading parameters and the joint geometries significantly affect the dynamic properties, including the irreversible strain, damage evolution, dynamic residual strength and fatigue life. Three failure modes of jointed rocks, which are principally controlled by joint geometries, occur in the simulations: splitting failure through the entire rock sample, sliding failure along joint planes and mixed failure, which are principally controlled by joint geometries. Furthermore, the progressive failure processes of the jointed rock samples are numerically observed, and the different loading stages can be distinguished by the relationship between the number of broken bonds and the axial stress.

Increased physical activity severely induces osteoarthritic changes in knee joints with papain induced sulfate-glycosaminoglycan depleted cartilage

PubMed Central

2014-01-01

Introduction Articular cartilage needs sulfated-glycosaminoglycans (sGAGs) to withstand high pressures while mechanically loaded. Chondrocyte sGAG synthesis is regulated by exposure to compressive forces. Moderate physical exercise is known to improve cartilage sGAG content and might protect against osteoarthritis (OA). This study investigated whether rat knee joints with sGAG depleted articular cartilage through papain injections might benefit from moderate exercise, or whether this increases the susceptibility for cartilage degeneration. Methods sGAGs were depleted from cartilage through intraarticular papain injections in the left knee joints of 40 Wistar rats; their contralateral joints served as healthy controls. Of the 40 rats included in the study, 20 rats remained sedentary, and the other 20 were subjected to a moderately intense running protocol. Animals were longitudinally monitored for 12 weeks with in vivo micro-computed tomography (μCT) to measure subchondral bone changes and single-photon emission computed tomography (SPECT)/CT to determine synovial macrophage activation. Articular cartilage was analyzed at 6 and 12 weeks with ex vivo contrast-enhanced μCT and histology to measure sGAG content and cartilage thickness. Results All outcome measures were unaffected by moderate exercise in healthy control joints of running animals compared with healthy control joints of sedentary animals. Papain injections in sedentary animals resulted in severe sGAG-depleted cartilage, slight loss of subchondral cortical bone, increased macrophage activation, and osteophyte formation. In running animals, papain-induced sGAG-depleted cartilage showed increased cartilage matrix degradation, sclerotic bone formation, increased macrophage activation, and more osteophyte formation. Conclusions Moderate exercise enhanced OA progression in papain-injected joints and did not protect against development of the disease. This was not restricted to more-extensive cartilage damage, but also resulted in pronounced subchondral sclerosis, synovial macrophage activation, and osteophyte formation. PMID:24472689

The tribology of metal-on-metal total hip replacements.

PubMed

Scholes, S C; Unsworth, A

2006-02-01

Total hip surgery is an effective way of alleviating the pain and discomfort caused by diseased or damaged joints. However, in the majority of cases, these joints have a finite life. The main reason for failure is osteolysis (bone resorption). It is well documented that an important cause of osteolysis, and therefore the subsequent loosening and failure of conventional metal- or ceramic-on-ultra-high molecular weight polyethylene joints, is the body's immunological response to the polyethylene wear particles. To avoid this, interest has been renewed in metal-on-metal joints. The intention of this paper is to review the studies that have taken place within different laboratories to determine the tribological performance of new-generation metal-on-metal total hip replacements. These types of joint offer a potential solution to enhance the longevity of prosthetic hip systems; however, problems may arise owing to the effects of metal ion release, which are, as yet, not fully understood.

Surgical Approaches to the Proximal Interphalangeal Joint.

PubMed

Cheah, Andre Eu-Jin; Yao, Jeffrey

2016-02-01

The proximal interphalangeal (PIP) joint may be affected by many conditions such as arthropathy, fractures, dislocations, and malunions. Whereas some of these conditions may be treated nonsurgically, many require open surgical intervention. Open interventions include implant arthroplasty or arthrodesis for arthropathy, open reduction internal fixation, or hemi-hamate arthroplasty for dorsal fracture-dislocations. Volar plate arthroplasty and corrective osteotomy for malunion about the PIP joint are also surgeries that may be required. The traditional approach to the PIP joint has been dorsal, which damages the delicate extensor apparatus with subsequent development of an extensor lag. This has led surgeons to explore volar and lateral approaches to the PIP joint. In this article, we describe each of these surgical approaches, discuss their advantages and disadvantages, and provide some guidance on which approach to choose based on the surgery that is to be performed. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

A Multi-Objective Advanced Design Methodology of Composite Beam-to-Column Joints Subjected to Seismic and Fire Loads

NASA Astrophysics Data System (ADS)

Pucinotti, Raffaele; Ferrario, Fabio; Bursi, Oreste S.

2008-07-01

A multi-objective advanced design methodology dealing with seismic actions followed by fire on steel-concrete composite full strength joints with concrete filled tubes is proposed in this paper. The specimens were designed in detail in order to exhibit a suitable fire behaviour after a severe earthquake. The major aspects of the cyclic behaviour of composite joints are presented and commented upon. The data obtained from monotonic and cyclic experimental tests have been used to calibrate a model of the joint in order to perform seismic simulations on several moment resisting frames. A hysteretic law was used to take into account the seismic degradation of the joints. Finally, fire tests were conducted with the objective to evaluate fire resistance of the connection already damaged by an earthquake. The experimental activity together with FE simulation demonstrated the adequacy of the advanced design methodology.

23 CFR 668.113 - Program and project procedures.

Code of Federal Regulations, 2010 CFR

2010-04-01

... program. This work may involve joint site inspections to view damage and reach tentative agreement on type... be sufficient to identify the approved disaster or catastrophe and to permit a determination of the...

Cartilage and bone damage in rheumatoid arthritis

PubMed Central

Maśliński, Włodzimierz; Prochorec-Sobieszek, Monika; Nieciecki, Michał; Sudoł-Szopińska, Iwona

2018-01-01

Rheumatoid arthritis (RA), which is a chronic inflammatory disease with a multifactorial aetiology, leads to partial or permanent disability in the majority of patients. It is characterised by persistent synovitis and formation of pannus, i.e. invasive synovial tissue, which ultimately leads to destruction of the cartilage, subchondral bone, and soft tissues of the affected joint. Moreover, inflammatory infiltrates in the subchondral bone, which can lead to inflammatory cysts and later erosions, play an important role in the pathogenesis of RA. These inflammatory infiltrates can be seen in magnetic resonance imaging (MRI) as bone marrow oedema (BME). BME is observed in 68–75% of patients in early stages of RA and is considered a precursor of rapid disease progression. The clinical significance of synovitis and bone marrow oedema as precursors of erosions is well established in daily practice, and synovitis, BME, cysts, hyaline cartilage defects and bone erosions can be detected by ultrasonography (US) and MRI. A less explored subject is the inflammatory and destructive potential of intra- and extra-articular fat tissue, which can also be evaluated in US and MRI. Finally, according to certain hypotheses, hyaline cartilage damage may trigger synovitis and lead to irreversible joint damage, and MRI may be used for preclinical detection of cartilage biochemical abnormalities. This review discusses the pathomechanisms that lead to articular cartilage and bone damage in RA, including erosion precursors such as synovitis and osteitis and panniculitis, as well as the role of imaging techniques employed to detect early cartilage damage and bone erosions. PMID:29853727

Popliteal tendon transposition for stabilization of the cranial cruciate ligament deficient stifle joint in dogs: an experimental study.

PubMed

Monnet, E; Schwarz, P D; Powers, B

1995-01-01

Popliteal tendon transposition was performed in five dogs with surgically induced cranial cruciate ligament rupture. After a lateral approach to the stifle joint, the popliteal tendon was severed distal to the sesamoid bone and transposed cranially onto the tibial crest to mimic the sagittal orientation of the cranial cruciate ligament. The origin of the popliteal tendon on the lateral femoral condyle was preserved. Lameness was not clinically detectable 2 months after surgery. At 6 months postoperatively, there was minimal radiographic and histopathologic evidence of degenerative joint disease in the stifle joints that had underwent surgery. There was no gross or microscopic evidence of meniscal damage found at necropsy 6 months after surgery. Biomechanical studies are warranted before recommending the procedure.

Aircraft Fatigue - with Particular Emphasis on Australian Operations and Research.

DTIC Science & Technology

1983-04-01

its research on the fatigue behaviour of full-scale alluminium -alloy structures by undertaking a major investigation using surplus wings from North...on the corrosion fatigue of Taper-Lok bolted joints in D6AC steel. In March 1973 the RAAF finally took delivery of its first F-IliC, and among the...development of multiple defects, corrosion /stress corrosion , detvrirrat- ion of bonded joints, undetected cracks or damage, inadquate repairs 2r untested

A structural health monitoring fastener for tracking fatigue crack growth in bolted metallic joints

NASA Astrophysics Data System (ADS)

Rakow, Alexi Schroder

Fatigue cracks initiating at fastener hole locations in metallic components are among the most common form of airframe damage. The fastener hole site has been surveyed as the second leading initiation site for fatigue related accidents of fixed wing aircraft. Current methods for inspecting airframes for these cracks are manual, whereby inspectors rely on non-destructive inspection equipment or hand-held probes to scan over areas of a structure. Use of this equipment often demands disassembly of the vehicle to search appropriate hole locations for cracks, which elevates the complexity and cost of these maintenance inspections. Improved reliability, safety, and reduced cost of such maintenance can be realized by the permanent integration of sensors with a structure to detect this damage. Such an integrated system of sensors would form a structural health monitoring (SHM) system. In this study, an Additive, Interleaved, Multi-layer Electromagnetic (AIME) sensor was developed and integrated with the shank of a fastener to form a SHM Fastener, a new SHM technology targeted at detection of fastener hole cracks. The major advantages of the SHM Fastener are its installation, which does not require joint layer disassembly, its capability to detect inner layer cracks, and its capability to operate in a continuous autonomous mode. Two methods for fabricating the proposed SHM Fastener were studied. The first option consisted of a thin flexible printed circuit film that was bonded around a thin metallic sleeve placed around the fastener shank. The second option consisted of coating sensor materials directly to the shank of a part in an effort to increase the durability of the sensor under severe loading conditions. Both analytical and numerical models were developed to characterize the capability of the sensors and provide a design tool for the sensor layout. A diagnostic technique for crack growth monitoring was developed to complete the SHM system, which consists of the sensor, data acquisition hardware, algorithm, and diagnostic display. The AIME sensor design, SHM Fastener, and complete SHM system are presented along with experimental results from a series of single-layer and bolted double lap joint aluminum laboratory specimens to validate the capability of these sensors to monitor metallic joints for fastener hole cracks. Fatigue cracks were successfully tracked to over 0.7 inches from the fastener hole in these tests. Sensor output obtained from single-layer fatigue specimens was compared with analytical predictions for fatigue crack growth versus cycle number showing a good correlation in trend between sensor output and predicted crack size.

Global Gene Expression Differences in Joints of Mice with Divergent Post Traumatic Osteoarthritis Phenotypes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kibui, J.

Osteoarthritis (OA) is a debilitating joint disease characterized by cartilage degradation which prompts pain, stiffness and swelling. Contributing factors include age, genetics, obesity, injury and overuse of joints. OA is defined by an acute phase and a chronic phase whereby inflammation and degeneration of articular cartilage and other tissues is followed by joint pain and limited mobility. Patients remain asymptomatic until substantial joint damage has occurred and therefore rely on long term surgical joint replacement and pain management as their sole treatment options. For this reason, there is an increasing need to identify early stage osteoarthritis biomarkers. Our study aimedmore » to identify and characterize gene expression variances in 3 different mouse strains (STR/ort, C57BL/6 and MRL/MpJ) with different susceptibility to post traumatic osteoarthritis (PTOA). Through RNA sequence analysis of whole knee joint RNA, we identified differentially expressed genes associated with the initial stages of PTOA in relation to mice with divergent phenotypes. These results will help elucidate potential mechanisms responsible for PTOA outcomes.« less

The effects PCSO-524®, a patented marine oil lipid and omega-3 PUFA blend derived from the New Zealand green lipped mussel (Perna canaliculus), on indirect markers of muscle damage and inflammation after muscle damaging exercise in untrained men: a randomized, placebo controlled trial.

PubMed

Mickleborough, Timothy D; Sinex, Jacob A; Platt, David; Chapman, Robert F; Hirt, Molly

2015-01-01

The purpose of the present study was to evaluate the effects of PCSO-524®, a marine oil lipid and n-3 LC PUFA blend, derived from New Zealand green- lipped mussel (Perna canaliculus), on markers of muscle damage and inflammation following muscle damaging exercise in untrained men. Thirty two untrained male subjects were randomly assigned to consume 1200 mg/d of PCSO- 524® (a green-lipped mussel oil blend) or placebo for 26 d prior to muscle damaging exercise (downhill running), and continued for 96 h following the muscle damaging exercise bout. Blood markers of muscle damage (skeletal muscle slow troponin I, sTnI; myoglobin, Mb; creatine kinase, CK), and inflammation (tumor necrosis factor, TNF-α), and functional measures of muscle damage (delayed onset muscle soreness, DOMS; pressure pain threshold, PPT; knee extensor joint range of motion, ROM; isometric torque, MVC) were assessed pre- supplementation (baseline), and multiple time points post-supplementation (before and after muscle damaging exercise). At baseline and 24 h following muscle damaging exercise peripheral fatigue was assessed via changes in potentiated quadriceps twitch force (∆Qtw,pot) from pre- to post-exhaustive cycling ergometer test in response to supra-maximal femoral nerve stimulation. Compared to placebo, supplementation with the green-lipped mussel oil blend significantly attenuated (p < 0.05) sTnI and TNF-α at 2, 24, 48, 72 and 96 h., Mb at 24, 48, 72, 96 h., and CK-MM at all-time points following muscle damaging exercise, significantly reduced (p < 0.05) DOMS at 72 and 96 h post-muscle damaging exercise, and resulted in significantly less strength loss (MVC) and provided a protective effect against joint ROM loss at 96 h post- muscle damaging exercise. At 24 h after muscle damaging exercise perceived pain was significantly greater (p < 0.05) compared to baseline in the placebo group only. Following muscle damaging exercise ∆Qtw,pot was significantly less (p < 0.05) on the green-lipped mussel oil blend compared to placebo. Supplementation with a marine oil lipid and n-3 LC PUFA blend (PCSO-524®), derived from the New Zealand green lipped mussel, may represent a useful therapeutic agent for attenuating muscle damage and inflammation following muscle damaging exercise.

The effect of boundary constraints on finite element modelling of the human pelvis.

PubMed

Watson, Peter J; Dostanpor, Ali; Fagan, Michael J; Dobson, Catherine A

2017-05-01

The use of finite element analysis (FEA) to investigate the biomechanics of anatomical systems critically relies on the specification of physiologically representative boundary conditions. The biomechanics of the pelvis has been the specific focus of a number of FEA studies previously, but it is also a key aspect in other investigations of, for example, the hip joint or new design of hip prostheses. In those studies, the pelvis has been modelled in a number of ways with a variety of boundary conditions, ranging from a model of the whole pelvic girdle including soft tissue attachments to a model of an isolated hemi-pelvis. The current study constructed a series of FEA models of the same human pelvis to investigate the sensitivity of the predicted stress distributions to the type of boundary conditions applied, in particular to represent the sacro-iliac joint and pubic symphysis. Varying the method of modelling the sacro-iliac joint did not produce significant variations in the stress distribution, however changes to the modelling of the pubic symphysis were observed to have a greater effect on the results. Over-constraint of the symphysis prevented the bending of the pelvis about the greater sciatic notch, and underestimated high stresses within the ilium. However, permitting medio-lateral translation to mimic widening of the pelvis addressed this problem. These findings underline the importance of applying the appropriate boundary conditions to FEA models, and provide guidance on suitable methods of constraining the pelvis when, for example, scan data has not captured the full pelvic girdle. The results also suggest a valid method for performing hemi-pelvic modelling of cadaveric or archaeological remains which are either damaged or incomplete. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Gas-tungsten arc welding of aluminum alloys

DOEpatents

Frye, L.D.

1982-03-25

The present invention is directed to a gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to profice a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surface are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy continguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

Comparative Study of 3-Dimensional Woven Joint Architectures for Composite Spacecraft Structures

NASA Technical Reports Server (NTRS)

Jones, Justin S.; Polis, Daniel L.; Segal, Kenneth N.

2011-01-01

The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate initiated an Advanced Composite Technology (ACT) Project through the Exploration Technology Development Program in order to support the polymer composite needs for future heavy lift launch architectures. As an example, the large composite structural applications on Ares V inspired the evaluation of advanced joining technologies, specifically 3D woven composite joints, which could be applied to traditionally manufactured barrel segments. Implementation of these 3D woven joint technologies may offer enhancements in damage tolerance without sacrificing weight. However, baseline mechanical performance data is needed to properly analyze the joint stresses and subsequently design/down-select a preform architecture. Six different configurations were designed and prepared for this study; each consisting of a different combination of warp/fill fiber volume ratio and preform interlocking method (z-fiber, fully interlocked, or hybrid). Tensile testing was performed for this study with the enhancement of a dual camera Digital Image Correlation (DIC) system which provides the capability to measure full-field strains and three dimensional displacements of objects under load. As expected, the ratio of warp/fill fiber has a direct influence on strength and modulus, with higher values measured in the direction of higher fiber volume bias. When comparing the z-fiber weave to a fully interlocked weave with comparable fiber bias, the z-fiber weave demonstrated the best performance in two different comparisons. We report the measured tensile strengths and moduli for test coupons from the 6 different weave configurations under study.

78 FR 61164 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-03

... have been found in inner cylinder pivot bores due to friction-generated heat damage. More frequent lubrication reduces friction in the joint. Also, the Boeing 767-200/-300/-300F maintenance planning document...

49 CFR 840.3 - Notification of railroad accidents.

Code of Federal Regulations, 2012 CFR

2012-10-01

... hospital; (2) The evacuation of a passenger train; (3) Damage to a tank car or container resulting in...) Accidents involving joint operations must be reported by the railroad that controls the track and directs...

49 CFR 840.3 - Notification of railroad accidents.

Code of Federal Regulations, 2011 CFR

2011-10-01

... hospital; (2) The evacuation of a passenger train; (3) Damage to a tank car or container resulting in...) Accidents involving joint operations must be reported by the railroad that controls the track and directs...

49 CFR 840.3 - Notification of railroad accidents.

Code of Federal Regulations, 2013 CFR

2013-10-01

... hospital; (2) The evacuation of a passenger train; (3) Damage to a tank car or container resulting in...) Accidents involving joint operations must be reported by the railroad that controls the track and directs...

49 CFR 840.3 - Notification of railroad accidents.

Code of Federal Regulations, 2010 CFR

2010-10-01

... hospital; (2) The evacuation of a passenger train; (3) Damage to a tank car or container resulting in...) Accidents involving joint operations must be reported by the railroad that controls the track and directs...

49 CFR 840.3 - Notification of railroad accidents.

Code of Federal Regulations, 2014 CFR

2014-10-01

... hospital; (2) The evacuation of a passenger train; (3) Damage to a tank car or container resulting in...) Accidents involving joint operations must be reported by the railroad that controls the track and directs...

Joint cartilage thickness and automated determination of bone age and bone health in juvenile idiopathic arthritis.

PubMed

Twilt, Marinka; Pradsgaard, Dan; Spannow, Anne Helene; Horlyck, Arne; Heuck, Carsten; Herlin, Troels

2017-08-10

BoneXpert is an automated method to calculate bone maturation and bone health index (BHI) in children with juvenile idiopathic arthritis (JIA). Cartilage thickness can also be seen as an indicator for bone health and arthritis damage. The objective of this study was to evaluate the relation between cartilage thickness, bone maturation and bone health in patients with JIA. Patients with JIA diagnosed according ILAR criteria included in a previous ultrasonography (US) study were eligible if hand radiographs were taken at the same time as the US examination. Of the 95 patients 67 met the inclusion criteria. Decreased cartilage thickness was seen in 27% of the examined joints. Decreased BHI was seen in half of the JIA patient, and delayed bone maturation was seen in 33% of patients. A combination of decreased BHI and bone age was seen in 1 out of 5 JIA patients. Decreased cartilage thickness in the knee, wrist and MCP joint was negatively correlated with delayed bone maturation but not with bone health index. Delayed bone maturation and decreased BHI were not related to a thinner cartilage, but a thicker cartilage. No relation with JADAS 10 was found. The rheumatologist should remain aware of delayed bone maturation and BHI in JIA patients with cartilage changes, even in the biologic era.

Osteoarticular Expression of Musashi-1 in an Experimental Model of Arthritis

PubMed Central

O'Valle, Francisco; Peregrina, Magdalena; Crespo-Lora, Vicente; Galindo-Moreno, Pablo; Roman, Maria; Aneiros-Fernandez, Jose; Aguilar, David; Gonzalez-Rey, Elena; Delgado, Mario; Hernandez-Cortes, Pedro

2015-01-01

Background. Collagen-induced arthritis (CIA), a murine experimental disease model induced by immunization with type II collagen (CII), is used to evaluate novel therapeutic strategies for rheumatoid arthritis. Adult stem cell marker Musashi-1 (Msi1) plays an important role in regulating the maintenance and differentiation of stem/precursor cells. The objectives of this investigation were to perform a morphological study of the experimental CIA model, evaluate the effect of TNFα-blocker (etanercept) treatment, and determine the immunohistochemical expression of Msi1 protein. Methods. CIA was induced in 50 male DBA1/J mice for analyses of tissue and serum cytokine; clinical and morphological lesions in limbs; and immunohistochemical expression of Msi1. Results. Clinically, TNFα-blocker treatment attenuated CIA on day 32 after immunization (P < 0.001). Msi1 protein expression was significantly higher in joints damaged by CIA than in those with no lesions (P < 0.0001) and was related to the severity of the lesions (Spearman's rho = 0.775, P = 0.0001). Conclusions. Treatment with etanercept attenuates osteoarticular lesions in the murine CIA model. Osteoarticular expression of Msi1 protein is increased in joints with CIA-induced lesion and absent in nonlesioned joints, suggesting that this protein is expressed when the lesion is produced in order to favor tissue repair. PMID:26064941

Pregnancy and oral contraceptive use do not significantly influence outcome in long term rheumatoid arthritis.

PubMed

Drossaers-Bakker, K W; Zwinderman, A H; van Zeben, D; Breedveld, F C; Hazes, J M W

2002-05-01

Oral contraceptives (OC) and pregnancy are known to have an influence on the risk of onset of rheumatoid arthritis (RA). Pregnancy itself has beneficial effects on the activity of the disease, with relapses post partum. It is not known, however, whether OC and pregnancies influence the ultimate outcome of RA. To explore whether OC use and pregnancies influence the 12 year outcome in RA as measured by radiological damage and disability. In a prospective inception cohort of 132 female patients with recent RA according to the 1987 American College of Rheumatology criteria-a cohort initially gathered to study the association between hormonal factors and the onset of RA-outcome was assessed in a follow up after 12 years. The outcome was evaluated in 112 (85%) women by the radiological damage of hands and feet as measured with the Sharp score modification van der Heijde (SHS), the damage of the large joints measured with the Larsen score (LS) of large joints (0-60), and the disability measured with the Health Assessment Questionnaire (HAQ). The median values of each outcome variable were calculated for several subgroups of patients stratified for OC use and pregnancies before and after onset of the disease and the tertiles of the total number of months of OC use and of pregnancies. The association of OC use and pregnancies before and after onset of the disease with the outcome variables was calculated using Spearman's rank correlation (r(s)). The combined influence of OC use and pregnancies on the SHS, LS, and HAQ at 12 years was estimated using ordinal polytomous logistic regression. The median values of the SHS, LS, and HAQ showed a trend towards less radiological joint damage and less disability in women with long term OC use and multiple pregnancies. This difference, however, was not significant, except for the HAQ score in women with three or more pregnancies in life. There was no association between pregnancies, however defined, and any parameter of RA outcome after 12 years (maximum r(s)=-0.10). The only significant correlation was found between OC use before symptom onset and the LS (r(s)=-0.22, p<0.05). The combination of hormonal variables explained no more than a maximum of 3% of the variance of the 12 year outcome as measured by the SHS. OC use and pregnancy do not significantly influence outcome in long term RA. There is, however, a trend for patients with multiple pregnancies and long term OC use to have less radiographic joint damage and a better functional level.

Flood Damages- savings potential for Austrian municipalities and evidence of adaptation

NASA Astrophysics Data System (ADS)

Unterberger, C.

2016-12-01

Recent studies show that the number of extreme precipitation events has increased globally and will continue to do so in the future. These observations are particularly true for central, northern and north-eastern Europe. These changes in the patterns of extreme events have direct repercussions for policy makers. Rojas et al. (2013) find that until 2080, annual damages could increase by a factor of 17 (from €5,5 bn/year today to € 98 bn/year in 2080) in the event that no adaptation measures are taken. Steininger et al. (2015) find that climate and weather induced extreme events account for an annual current welfare loss of about € 1 billion in Austria. As a result, policy makers will need to understand the interaction between hazard, exposure and vulnerability, with the goal of achieving flood risk reduction. Needed is a better understanding of where exposure, vulnerability and eventually flood risk are highest, i.e. where to reduce risk first and which factors drive existing flood risk. This article analyzes direct flood losses as reported by 1153 Austrian municipalities between 2005 and 2013. To achieve comparability between flood damages and municipalities' ordinary spending, a "vulnerability threshold" is introduced suggesting that flood damages should be lower than 5% of municipalities' average annual ordinary spending. It is found that the probability that flood damages exceed this vulnerability threshold is 12%. To provide a reliable estimate for that exceedance probability the joint distribution of damages and spending is modelled by means of a copula approach. Based on the joint distribution, a Monte Carlo simulation is conducted to derive uncertainty ranges for the exceedance probability. To analyze the drivers of flood damages and the effect they have on municipalities' spending, two linear regression models are estimated. Hereby obtained results suggest that damages increase significantly for those municipalities located along the shores of the river Danube and decrease significantly for municipalities that experienced floods in the past- indicating successful adaptation. As for the relationship between flood damages and municipalities' spending, the regression results indicate that flood damages have a significant positive impact.

A personalized 3D-printed prosthetic joint replacement for the human temporomandibular joint: From implant design to implantation.

PubMed

Ackland, David C; Robinson, Dale; Redhead, Michael; Lee, Peter Vee Sin; Moskaljuk, Adrian; Dimitroulis, George

2017-05-01

Personalized prosthetic joint replacements have important applications in cases of complex bone and joint conditions where the shape and size of off-the-shelf components may not be adequate. The objective of this study was to design, test and fabricate a personalized 3D-printed prosthesis for a patient requiring total joint replacement surgery of the temporomandibular joint (TMJ). The new 'Melbourne' prosthetic TMJ design featured a condylar component sized specifically to the patient and fixation screw positions that avoid potential intra-operative damage to the mandibular nerve. The Melbourne prosthetic TMJ was developed for a 58-year-old female recipient with end-stage osteoarthritis of the TMJ. The load response of the prosthesis during chewing and a maximum-force bite was quantified using a personalized musculoskeletal model of the patient's masticatory system developed using medical images. The simulations were then repeated after implantation of the Biomet Microfixation prosthetic TMJ, an established stock device. The maximum condylar stresses, screw stress and mandibular stress at the screw-bone interface were lower in the Melbourne prosthetic TMJ (259.6MPa, 312.9MPa and 198.4MPa, respectively) than those in the Biomet Microfixation device (284.0MPa, 416.0MPa and 262.2MPa, respectively) during the maximum-force bite, with similar trends also observed during the chewing bite. After trialing surgical placement and evaluating prosthetic TMJ stability using cadaveric specimens, the prosthesis was fabricated using 3D printing, sterilized, and implanted into the female recipient. Six months post-operatively, the prosthesis recipient had a normal jaw opening distance (40.0 mm), with no complications identified. The new design features and immediate load response of the Melbourne prosthetic TMJ suggests that it may provide improved clinical and biomechanical joint function compared to a commonly used stock device, and reduce risk of intra-operative nerve damage during placement. The framework presented may be useful for designing and testing customized devices for the treatment of debilitating bone and joint conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

A maximum entropy fracture model for low and high strain-rate fracture in TinSilverCopper alloys

NASA Astrophysics Data System (ADS)

Chan, Dennis K.

SnAgCu solder alloys exhibit significant rate-dependent constitutive behavior. Solder joints made of these alloys exhibit failure modes that are also rate-dependent. Solder joints are an integral part of microelectronic packages and are subjected to a wide variety of loading conditions which range from thermo-mechanical fatigue to impact loading. Consequently, there is a need for non-empirical rate-dependent failure theory that is able to accurately predict fracture in these solder joints. In the present thesis, various failure models are first reviewed. But, these models are typically empirical or are not valid for solder joints due to limiting assumptions such as elastic behavior. Here, the development and validation of a maximum entropy fracture model (MEFM) valid for low strain-rate fracture in SnAgCu solders is presented. To this end, work on characterizing SnAgCu solder behavior at low strain-rates using a specially designed tester to estimate parameters for constitutive models is presented. Next, the maximum entropy fracture model is reviewed. This failure model uses a single damage accumulation parameter and relates the risk of fracture to accumulated inelastic dissipation. A methodology is presented to extract this model parameter through a custom-built microscale mechanical tester for Sn3.8Ag0.7Cu solder. This single parameter is used to numerically simulate fracture in two solder joints with entirely different geometries. The simulations are compared to experimentally observed fracture in these same packages. Following the simulations of fracture at low strain rate, the constitutive behavior of solder alloys across nine decades of strain rates through MTS compression tests and split-Hopkinson bar are presented. Preliminary work on using orthogonal machining as novel technique of material characterization at high strain rates is also presented. The resultant data from the MTS compression and split-Hopkinson bar tester is used to demonstrate the localization of stress to the interface of solder joints at high strain rates. The MEFM is further extended to predict failure in brittle materials. Such an extension allows for fracture prediction within intermetallic compounds (IMCs) in solder joints. It has been experimentally observed that the failure mode shifts from bulk solder to the IMC layer with increasing loading rates. The extension of the MEFM would allow for prediction of the fracture mode within the solder joint under different loading conditions. A fracture model capable of predicting failure modes at higher strain rates is necessary, as mobile electronics are becoming ubiquitous. Mobile devices are prone to being dropped which can induce loading rates within solder joints that are much larger than experienced under thermo-mechanical fatigue. A range of possible damage accumulation parameters for Cu6Sn 5 is determined for the MEFM. A value within the aforementioned range is used to demonstrate the increasing likelihood of IMC fracture in solder joints with larger loading rates. The thesis is concluded with remarks about ongoing work that include determining a more accurate damage accumulation parameter for Cu6Sn 5 IMC, and on using machining as a technique for extracting failure parameters for the MEFM.

Thermographic and microscopic evaluation of LARS knee ligament tearing.

PubMed

Pătraşcu, Jenel Marian; Amarandei, Mihaela; Kun, Karla Noemy; Borugă, Ovidiu; Totorean, Alina; Andor, Bogdan; Florescu, Sorin

2014-01-01

Damage to knee articular ligaments causes important functional problems and adversely affects particularly the stability of the knee joint. Several methods were developed in order to repair damage to the anterior cruciate ligament (ACL), which employ autografts, allografts, as well as synthetic ligaments. One such synthetic scaffold, the ligament advanced reinforcement system (LARS) synthetic ligament is made of non-absorbing polyethylene terephthalate fibers whose structure allow tissue ingrowths in the intra-articular part, improving the stability of the joint. The LARS ligament is nowadays widely used in modern knee surgery in the Europe, Canada, China or Japan. This paper evaluates LARS ligament from two perspectives. The first regards a study done by the Orthopedics Clinic II, Timisoara, Romania, which compared results obtained by employing two techniques of ACL repair - the Bone-Tendon-Bone (BTB) or LARS arthroscopic, intra-articular techniques. This study found that patients treated with the BTB technique presented with an IKDC score of 45.82±1.14 units preoperative, with increasing values in the first nine months after each implant post-surgical ligament restoration, reaching an average value of 75.92 ± 2.88 units postoperative. Patients treated with the LARS technique presented with an IKDC score of 43.64 ± 1.11 units preoperative, and a score of 77.32 ± 2.71 units postoperative. The second perspective describes the thermographic and microscopic analysis of an artificial knee ligament tearing or loosening. The objective of the study was to obtain information regarding the design of artificial ligaments in order to expand their lifespan and avoid complications such as recurring synovitis, osteoarthritis and trauma of the knee joint. Thermographic data has shown that tearing begins from the inside out, thus improving the inner design of the ligament would probably enhance its durability. An optical microscope was employed to obtain images of structural damage in the inner layers, for use in further analysis of the tears. In conclusion, the LARS artificial ligament, like the BTB technique, displays both advantages and disadvantages. It is important to understand that these two options of ACL lesion repair are not competing. LARS could, in addition to its use in primary ACL ruptures, be utilized in revisions of autologous graft rupture post primary ACL repair.

A new method for isolation of polyethylene wear debris from tissue and synovial fluid.

PubMed

Visentin, Manuela; Stea, Susanna; Squarzoni, Stefano; Antonietti, Barbara; Reggiani, Matteo; Toni, Aldo

2004-11-01

Sub-micron-sized ultrahigh molecular-weight polyethylene (PE) debris is generated in the joint space as a result of articulation and cyclic loading of an orthopaedic implant. Its characterization requires isolation and subsequent analysis by ultra-structural methods. An innovative method based on the digestion of paraffin-embedded tissue samples was proposed. Tissue slices were digested with sodium hypochlorite directly on polycarbonate filter. The same procedure could be applied also to fresh synovial fluid. Plastic particles were not lost or damaged during treatment. Chemical identification of particles was done by micro-Raman spectroscopy that confirmed purity of retrieved PE particles. Size and shape of PE particles were characterised using scanning electron microscopy and were comparable in number and morphology to the retrieval by other authors. Equivalent diameter ranged from 0.48 to 0.95microm and particle number ranged from 9 to 23x10(9)/cm(3).

ALPHA-CTX is associated with subchondral bone turnover and predicts progression of joint space narrowing and osteophytes in osteoarthritis

PubMed Central

Huebner, Janet L; Bay-Jensen, Anne C; Huffman, Kim M; He, Yi; Leeming, Diana J; McDaniel, Gary E; Karsdal, Morten A; Kraus, Virginia B

2014-01-01

Objective To evaluate joint tissue remodeling, with urinary collagen biomarkers, uALPHA CTX and uCTXII, and their association with osteoarthritis (OA) severity, progression, and localized knee bone turnover. Methods Participants (N=149) with symptomatic and radiographic knee OA underwent fixed flexion knee radiography at baseline and 3 years, and late-phase bone scintigraphy of both knees at baseline, scored semi-quantitatively for osteophyte (OST) and joint space narrowing (JSN) severity and uptake intensity with scores summed across knees. Urinary concentrations of ALPHA CTX and CTXII were determined by ELISA. Immunohistochemistry of human OA knees was performed to localize the joint tissue origin of the biomarker epitopes. Results uALPHA CTX correlated strongly with intensity of bone scintigraphic uptake, and JSN and OST progression (risk ratio=13.2 and 3, respectively). uCTXII was strongly associated with intensity of bone scintigraphic uptake, with JSN and OST severity, and OA progression based on OST. uALPHA CTX localized primarily to high bone turnover areas in subchondral bone; CTXII localized to the bone-cartilage interface, the tidemark, and damaged articular cartilage. Conclusion Baseline uALPHA CTX, localized to high turnover areas of subchondral bone, was associated with dynamic bone turnover of knees signified by scintigraphy, and progression of both OST and JSN. uCTXII correlated with JSN and OST severity, and progression of OST. To our knowledge, this represents the first report of serological markers reflecting subchondral bone turnover. These collagen markers may be useful for non-invasive detection and quantification of active subchondral bone turnover and joint remodeling in knee OA. PMID:24909851

Estimating unknown parameters in haemophilia using expert judgement elicitation.

PubMed

Fischer, K; Lewandowski, D; Janssen, M P

2013-09-01

The increasing attention to healthcare costs and treatment efficiency has led to an increasing demand for quantitative data concerning patient and treatment characteristics in haemophilia. However, most of these data are difficult to obtain. The aim of this study was to use expert judgement elicitation (EJE) to estimate currently unavailable key parameters for treatment models in severe haemophilia A. Using a formal expert elicitation procedure, 19 international experts provided information on (i) natural bleeding frequency according to age and onset of bleeding, (ii) treatment of bleeds, (iii) time needed to control bleeding after starting secondary prophylaxis, (iv) dose requirements for secondary prophylaxis according to onset of bleeding, and (v) life-expectancy. For each parameter experts provided their quantitative estimates (median, P10, P90), which were combined using a graphical method. In addition, information was obtained concerning key decision parameters of haemophilia treatment. There was most agreement between experts regarding bleeding frequencies for patients treated on demand with an average onset of joint bleeding (1.7 years): median 12 joint bleeds per year (95% confidence interval 0.9-36) for patients ≤ 18, and 11 (0.8-61) for adult patients. Less agreement was observed concerning estimated effective dose for secondary prophylaxis in adults: median 2000 IU every other day The majority (63%) of experts expected that a single minor joint bleed could cause irreversible damage, and would accept up to three minor joint bleeds or one trauma related joint bleed annually on prophylaxis. Expert judgement elicitation allowed structured capturing of quantitative expert estimates. It generated novel data to be used in computer modelling, clinical care, and trial design. © 2013 John Wiley & Sons Ltd.

Growing Three-Dimensional Cartilage-Cell Cultures

NASA Technical Reports Server (NTRS)

Spaulding, Glenn F.; Prewett, Tacey L.; Goodwin, Thomas J.

1995-01-01

Process for growing three-dimensional cultures of mammalian cartilage from normal mammalian cells devised. Effected using horizontal rotating bioreactor described in companion article, "Simplified Bioreactor for Growing Mammalian Cells" (MSC-22060). Bioreactor provides quiescent environment with generous supplies of nutrient and oxygen. Initiated with noncartilage cells. Artificially grown tissue resembles that in mammalian cartilage. Potential use in developing therapies for damage to cartilage by joint and back injuries and by such inflammatory diseases as arthritis and temporal-mandibular joint disease. Also used to test nonsteroid anti-inflammation medicines.

The F-35 JSF: Beginning of the End for Blue-Water Ops?

DTIC Science & Technology

2010-04-06

DAMAGED BY INGESTING DEBRIS, THE RESULT OF SWITCHING TO A SINGLE-ENGINE AIRCRAFT FOR THE NAW’S PRIMARY FIGHTER. THE LOCKHEED MARTIN F-35 LIGHTNING II JOINT...States Navy Thesis: Single-engine aircraft have long been considered unsuitable for Naval Aviation, but now the future of blue-water operations is...dependent on the success and reliability of an aircraft · powered by a single engine, the Lockheed -Martin F-35Lightning II Joint Strike Fighter

D.I.M.E.F.I.L.: A Wordwide Campaign for Life

DTIC Science & Technology

2007-05-01

Joint Advanced Warfighting School in partial satisfaction of the requirements of a Master of Science Degree in Joint Campaign Planning and Strategy...of them. Al-Tamini stated his job was to “get a bomber to the best spot for an attack, where he can inflict the most damage.” Sometimes he...majority of militants were unmarried males 20-29 years old from families with both parents living and 6-10 siblings, and who completed secondary

Thermomechanical behavior of tin-rich (lead-free) solders

NASA Astrophysics Data System (ADS)

Sidhu, Rajen Singh

In order to adequately characterize the behavior of ball-grid-array (BGA) Pb-free solder spheres in electronic devices, the microstructure and thermomechanical behavior need to be studied. Microstructure characterization of pure Sn, Sn-0.7Cu, Sn-3.5Ag, and Sn-3.9Ag-0.7Cu alloys was conducted using optical microscopy, scanning electron microscopy, transmission electron microscopy, image analysis, and a novel serial sectioning 3D reconstruction process. Microstructure-based finite-element method (FEM) modeling of deformation in Sn-3.5Ag alloy was conducted, and it will be shown that this technique is more accurate when compared to traditional unit cell models for simulating and understanding material behavior. The effect of cooling rate on microstructure and creep behavior of bulk Sn-rich solders was studied. The creep behavior was evaluated at 25, 95, and 120°C. Faster cooling rates were found to increase the creep strength of the solders due to refinement of the solder microstructure. The creep behavior of Sn-rich single solder spheres reflowed on Cu substrates was studied at 25, 60, 95, and 130°C. Testing was conducted using a microforce testing system, with lap-shear geometry samples. The solder joints displayed two distinct creep behaviors: (a) precipitation-strengthening (Sn-3.5Ag and Sn-3.9Ag-0.7Cu) and (b) power law creep accommodated by grain boundary sliding (GBS) (Sn and Sn-0.7Cu). The relationship between microstructural features (i.e. intermetallic particle size and spacing), stress exponents, threshold stress, and activation energies are discussed. The relationship between small-length scale creep behavior and bulk behavior is also addressed. To better understand the damage evolution in Sn-rich solder joints during thermal fatigue, the local damage will be correlated to the cyclic hysteresis behavior and crystal orientations present in the Sn phase of solder joints. FEM modeling will also be utilized to better understand the macroscopic and local strain response of the lap shear geometry.

Targeting of viral interleukin-10 with an antibody fragment specific to damaged arthritic cartilage improves its therapeutic potency

PubMed Central

2014-01-01

Introduction We previously demonstrated that a single-chain fragment variable (scFv) specific to collagen type II (CII) posttranslationally modified by reactive oxygen species (ROS) can be used to target anti-inflammatory therapeutics specifically to inflamed arthritic joints. The objective of the present study was to demonstrate the superior efficacy of anti-inflammatory cytokines when targeted to inflamed arthritic joints by the anti-ROS modified CII (anti-ROS-CII) scFv in a mouse model of arthritis. Methods Viral interleukin-10 (vIL-10) was fused to anti-ROS-CII scFv (1-11E) with a matrix-metalloproteinase (MMP) cleavable linker to create 1-11E/vIL-10 fusion. Binding of 1-11E/vIL-10 to ROS-CII was determined by enzyme-linked immunosorbent assay (ELISA), Western blotting, and immune-staining of arthritic cartilage, whereas vIL-10 bioactivity was evaluated in vitro by using an MC-9 cell-proliferation assay. Specific in vivo localization and therapeutic efficacy of 1-11E/vIL-10 was tested in the mouse model of antigen-induced arthritis. Results 1-11E/vIL-10 bound specifically to ROS-CII and to damaged arthritic cartilage. Interestingly, the in vitro vIL-10 activity in the fusion protein was observed only after cleavage with MMP-1. When systemically administered to arthritic mice, 1-11E/vIL-10 localized specifically to the arthritic knee, with peak accumulation observed after 3 days. Moreover, 1-11E/vIL-10 reduced inflammation significantly quicker than vIL-10 fused to the control anti-hen egg lysozyme scFv (C7/vIL10). Conclusions Targeted delivery of anti-inflammatory cytokines potentiates their anti-arthritic action in a mouse model of arthritis. Our results further support the hypothesis that targeting biotherapeutics to arthritic joints may be extended to include anti-inflammatory cytokines that lack efficacy when administered systemically. PMID:25029910

Transportation Infrastructure Robustness : Joint Engineering and Economic Analysis

DOT National Transportation Integrated Search

2017-11-01

The objectives of this study are to develop a methodology for assessing the robustness of transportation infrastructure facilities and assess the effect of damage to such facilities on travel demand and the facilities users welfare. The robustness...

[Homeostasis and Disorder of Musculoskeletal System.Progress in the treatment of rheumatoid arthritis.

PubMed

Tanaka, Yoshiya

Rheumatoid arthritis is a systemic autoimmune disease characterized by inflammation and joint damage that causes significant morbidity and mortality. Rapid and appropriate intervention using disease-modifying anti-rheumatic drugs(DMARDs)is prerequisite to halt joint destruction and long-term functional disabilities. Recent progress in the treatment strategy has brought about paradigm shift for the management of the disease, namely, the combined use of methotrexate, a synthetic DMARD, and a biologic DMARD targeting TNF, IL-6 and T cells has revolutionized treatment of rheumatoid arthritis. Clinical remission is now realistic targets for the treatment, achieved by a large proportion of rheumatoid arthritis patients, which leads to structural remission without damage in bone and cartilage as well as functional remission. Furthermore, orally available small but strong molecules targeting Janus kinase(JAK)are emerging. When DMARDs are prescribed, appropriate selection of DMARDs, adequate screening, regular monitoring and systemic management are required.

The Relationship between Working Conditions and Adverse Health Symptoms of Employee in Solar Greenhouse.

PubMed

Zhang, Min; Wang, Xiu Feng; Cui, Xiu Min; Wang, Jian; Yu, Shi Xin

2015-02-01

To determine the correlation between the working environment and the health status of employees in solar greenhouse, 1171 employees were surveyed. The results show the 'Greenhouse diseases' are affected by many factors. Among general uncomforts, the morbidity of the bone and joint damage is the highest and closely related to labor time and age. Planting summer squash and wax gourd more easily cause skin pruritus. Asthma-related cough, eye disease, and skin pruritus are significantly correlated with the cultivation of wax gourd. The application of inorganic fertilizer and fertigation dramatically induce the bone and joint damage. The smell of covering film greatly influence skin pruritus. Personal protection is badly scanty and normative occupational health and safety need to be completed. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Caffeine suppresses homologous recombination through interference with RAD51-mediated joint molecule formation

PubMed Central

Zelensky, Alex N.; Sanchez, Humberto; Ristic, Dejan; Vidic, Iztok; van Rossum-Fikkert, Sari E.; Essers, Jeroen; Wyman, Claire; Kanaar, Roland

2013-01-01

Caffeine is a widely used inhibitor of the protein kinases that play a central role in the DNA damage response. We used chemical inhibitors and genetically deficient mouse embryonic stem cell lines to study the role of DNA damage response in stable integration of the transfected DNA and found that caffeine rapidly, efficiently and reversibly inhibited homologous integration of the transfected DNA as measured by several homologous recombination-mediated gene-targeting assays. Biochemical and structural biology experiments revealed that caffeine interfered with a pivotal step in homologous recombination, homologous joint molecule formation, through increasing interactions of the RAD51 nucleoprotein filament with non-homologous DNA. Our results suggest that recombination pathways dependent on extensive homology search are caffeine-sensitive and stress the importance of considering direct checkpoint-independent mechanisms in the interpretation of the effects of caffeine on DNA repair. PMID:23666627

Sensate Scaffolds Can Reliably Detect Joint Loading

PubMed Central

Bliss, C. L.; Szivek, J. A.; Tellis, B. C.; Margolis, D. S.; Schnepp, A. B.; Ruth, J. T.

2008-01-01

Treatment of cartilage defects is essential to the prevention of osteoarthritis. Scaffold-based cartilage tissue engineering shows promise as a viable technique to treat focal defects. Added functionality can be achieved by incorporating strain gauges into scaffolds, thereby providing a real-time diagnostic measurement of joint loading. Strain-gauged scaffolds were placed into the medial femoral condyles of 14 adult canine knees and benchtop tested. Loads between 75 and 130 N were applied to the stifle joints at 30°, 50°, and 70° of flexion. Strain-gauged scaffolds were able to reliably assess joint loading at all applied flexion angles and loads. Pressure sensitive films were used to determine joint surface pressures during loading and to assess the effect of scaffold placement on joint pressures. A comparison of peak pressures in control knees and joints with implanted scaffolds, as well as a comparison of pressures before and after scaffold placement, showed that strain-gauged scaffold implantation did not significantly alter joint pressures. Future studies could possibly use strain-gauged scaffolds to clinically establish normal joint loads and to determine loads that are damaging to both healthy and tissue-engineered cartilage. Strain-gauged scaffolds may significantly aid the development of a functional engineered cartilage tissue substitute as well as provide insight into the native environment of cartilage. PMID:16941586

Preventing Collateral Damage in Crohn’s Disease: The Lémann Index

PubMed Central

Fiorino, Gionata; Bonifacio, Cristiana; Peyrin-Biroulet, Laurent

2016-01-01

Crohn’s disease [CD] is a chronic progressive and destructive condition. Half of all CD patients will develop bowel damage at 10 years. As in rheumatic diseases, preventing the organ damage consequent to CD complications [fistula, abscess, and/or stricture] is emerging as a new therapeutic goal for these patients in clinical practice. This might be the only way to alter disease course, as surgery is often required for disease complications. Similar to the joint damage in rheumatoid arthritis, bowel damage has also emerged as a new endpoint in disease-modification trials such as the REACT trial. Recently, the Lemann Index [LI] has been developed to measure CD-related bowel damage, and to assess damage progression over time, in order to evaluate the impact of therapeutic strategies in terms of preventing bowel damage. While validation is pending, recent reports suggested that bowel damage is reversible by anti-tumour necrosis factor [TNF] therapy. The Lémann index may play a key role in CD management, and should be implemented in all upcoming disease-modification trials in CD. PMID:26744441

Deregulation upon DNA damage revealed by joint analysis of context-specific perturbation data

PubMed Central

2011-01-01

Background Deregulation between two different cell populations manifests itself in changing gene expression patterns and changing regulatory interactions. Accumulating knowledge about biological networks creates an opportunity to study these changes in their cellular context. Results We analyze re-wiring of regulatory networks based on cell population-specific perturbation data and knowledge about signaling pathways and their target genes. We quantify deregulation by merging regulatory signal from the two cell populations into one score. This joint approach, called JODA, proves advantageous over separate analysis of the cell populations and analysis without incorporation of knowledge. JODA is implemented and freely available in a Bioconductor package 'joda'. Conclusions Using JODA, we show wide-spread re-wiring of gene regulatory networks upon neocarzinostatin-induced DNA damage in Human cells. We recover 645 deregulated genes in thirteen functional clusters performing the rich program of response to damage. We find that the clusters contain many previously characterized neocarzinostatin target genes. We investigate connectivity between those genes, explaining their cooperation in performing the common functions. We review genes with the most extreme deregulation scores, reporting their involvement in response to DNA damage. Finally, we investigate the indirect impact of the ATM pathway on the deregulated genes, and build a hypothetical hierarchy of direct regulation. These results prove that JODA is a step forward to a systems level, mechanistic understanding of changes in gene regulation between different cell populations. PMID:21693013

Deregulation upon DNA damage revealed by joint analysis of context-specific perturbation data.

PubMed

Szczurek, Ewa; Markowetz, Florian; Gat-Viks, Irit; Biecek, Przemysław; Tiuryn, Jerzy; Vingron, Martin

2011-06-21

Deregulation between two different cell populations manifests itself in changing gene expression patterns and changing regulatory interactions. Accumulating knowledge about biological networks creates an opportunity to study these changes in their cellular context. We analyze re-wiring of regulatory networks based on cell population-specific perturbation data and knowledge about signaling pathways and their target genes. We quantify deregulation by merging regulatory signal from the two cell populations into one score. This joint approach, called JODA, proves advantageous over separate analysis of the cell populations and analysis without incorporation of knowledge. JODA is implemented and freely available in a Bioconductor package 'joda'. Using JODA, we show wide-spread re-wiring of gene regulatory networks upon neocarzinostatin-induced DNA damage in Human cells. We recover 645 deregulated genes in thirteen functional clusters performing the rich program of response to damage. We find that the clusters contain many previously characterized neocarzinostatin target genes. We investigate connectivity between those genes, explaining their cooperation in performing the common functions. We review genes with the most extreme deregulation scores, reporting their involvement in response to DNA damage. Finally, we investigate the indirect impact of the ATM pathway on the deregulated genes, and build a hypothetical hierarchy of direct regulation. These results prove that JODA is a step forward to a systems level, mechanistic understanding of changes in gene regulation between different cell populations.

Intra-articular Recombinant Human Proteoglycan 4 Mitigates Cartilage Damage Following Destabilization of the Medial Meniscus in the Yucatan Minipig

PubMed Central

Waller, Kimberly A.; Chin, Kaitlyn E.; Jay, Gregory D.; Zhang, Ling X.; Teeple, Erin; McAllister, Scott; Badger, Gary J.; Schmidt, Tannin A.; Fleming, Braden C.

2016-01-01

Background Lubricin, or proteoglycan 4 (PRG4), is a glycoprotein responsible for joint boundary lubrication. PRG4 has been previously shown to be down-regulated following traumatic joint injury such as a meniscal tear. There is preliminary evidence suggesting that intra-articular injection of PRG4 post-injury will reduce cartilage damage in rat models of surgically-induced post-traumatic osteoarthritis. Objective To determine the efficacy of intra-articular injection of full length recombinant human lubricin (rhPRG4) for reducing cartilage damage after medial meniscus destabilization (DMM) in a pre-clinical large animal model. Study Design Controlled laboratory study Methods Unilateral DMM was performed in 29 Yucutan minipigs. One week post-DMM, animals received 3 weekly intra-articular injections (3cc/injection): 1) rhPRG4 [1.3mg/ml; n=10], 2) rhPRG4+hyaluronan [1.3mg/ml rhPRG4 and 3mg/ml hyaluronan (~950 kDA); n=10], and 3) phosphate buffered saline [PBS; n=9]. Hind limbs were harvested 26 weeks post-surgery. Cartilage integrity was evaluated using macroscopic (India Ink) and microscopic (Safranin O-fast green and hematoxylin & eosin) scoring systems. Secondary outcomes evaluated using ELISA included PRG4 levels in synovial fluid, CTX-II concentrations in urine and serum, and IL-1β levels in synovial fluid and serum. Results The rhPRG4 group had significantly less macroscopic cartilage damage in the medial tibial plateau compared to the PBS group (p=.002). No difference was found between the rhPRG4+hyaluronan and PBS groups (p=.23). However, no differences in microscopic damage scores were observed between the three groups (p=.70). PRG4 production was elevated in the rhPRG4 group synovial fluid compared to the PBS group (p=.033). The rhPRG4 group presented significantly lower urinary CTX-II levels, but not serum levels, when compared to the PBS (p=.013) and rhPRG4+hyaluronan (p=.011) groups. In serum and synovial fluid, both rhPRG4 (p=.006; p=.017) and rhPRG4+hyaluronan groups (p=.009; p=.03) presented decreased IL-1β levels. Conclusion All groups exhibited significant cartilage degeneration following DMM surgery. However, animals treated with rhPRG4 had the least amount of cartilage damage and less inflammation, providing evidence that intra-articular injections of rhPRG4 may slow the progression of post-traumatic osteoarthritis. Clinical Relevance Patients with meniscal trauma are at high risk for post-traumatic osteoarthritis. This study demonstrates that an intra-articular injection regimen of rhPRG4 may attenuate cartilage damage following meniscal injury. PMID:28129516

Mechanical characterization of 3D printed anisotropic cementitious material by the electromechanical transducer

NASA Astrophysics Data System (ADS)

Ma, Guowei; Zhang, Junfei; Wang, Li; Li, Zhijian; Sun, Junbo

2018-07-01

3D concrete printing is an innovative and promising construction method that is rapidly gaining ground in recent years. This technique extrudes premixed concrete materials through a nozzle to build structural components layer upon layer without formworks. The build-up process of depositing filaments or layers intrinsically produce laminated structures and create weak joints between adjacent layers. It is of great significance to clearly elaborate the mechanical characteristics of 3D printed components response to various applied loads and the different performance from the mould-cast ones. In this study, a self-developed 3D printing system was invented and applied to fabricate concrete samples. Three points bending test and direct double shear test were carried out to investigate the mechanical properties of 3D printed prisms. The anisotropic behaviors were probed by loading in different directions. Meanwhile, piezoelectric lead zirconate titanate (PZT) transducers were implemented to monitor the damage evolution of the printed samples in the loading process based on the electromechanical impedance method. Test results demonstrate that the tensile stresses perpendicular to the weaken interfaces formed between filaments were prone to induce cracks than those parallel to the interfaces. The damages of concrete materials resulted in the decrease in the frequency and a change in the amplitude in the conductance spectrum acquired by mounted PZT patches. The admittance signatures showed a clear gradation of the examined damage levels of printed prisms exposed to applied loadings.

Improved damage imaging in aerospace structures using a piezoceramic hybrid pin-force wave generation model

NASA Astrophysics Data System (ADS)

Ostiguy, Pierre-Claude; Quaegebeur, Nicolas; Masson, Patrice

2014-03-01

In this study, a correlation-based imaging technique called "Excitelet" is used to monitor an aerospace grade aluminum plate, representative of an aircraft component. The principle is based on ultrasonic guided wave generation and sensing using three piezoceramic (PZT) transducers, and measurement of reflections induced by potential defects. The method uses a propagation model to correlate measured signals with a bank of signals and imaging is performed using a roundrobin procedure (Full-Matrix Capture). The formulation compares two models for the complex transducer dynamics: one where the shear stress at the tip of the PZT is considered to vary as a function of the frequency generated, and one where the PZT is discretized in order to consider the shear distribution under the PZT. This method allows taking into account the transducer dynamics and finite dimensions, multi-modal and dispersive characteristics of the material and complex interactions between guided wave and damages. Experimental validation has been conducted on an aerospace grade aluminum joint instrumented with three circular PZTs of 10 mm diameter. A magnet, acting as a reflector, is used in order to simulate a local reflection in the structure. It is demonstrated that the defect can be accurately detected and localized. The two models proposed are compared to the classical pin-force model, using narrow and broad-band excitations. The results demonstrate the potential of the proposed imaging techniques for damage monitoring of aerospace structures considering improved models for guided wave generation and propagation.

Robot Position Sensor Fault Tolerance

NASA Technical Reports Server (NTRS)

Aldridge, Hal A.

1997-01-01

Robot systems in critical applications, such as those in space and nuclear environments, must be able to operate during component failure to complete important tasks. One failure mode that has received little attention is the failure of joint position sensors. Current fault tolerant designs require the addition of directly redundant position sensors which can affect joint design. A new method is proposed that utilizes analytical redundancy to allow for continued operation during joint position sensor failure. Joint torque sensors are used with a virtual passive torque controller to make the robot joint stable without position feedback and improve position tracking performance in the presence of unknown link dynamics and end-effector loading. Two Cartesian accelerometer based methods are proposed to determine the position of the joint. The joint specific position determination method utilizes two triaxial accelerometers attached to the link driven by the joint with the failed position sensor. The joint specific method is not computationally complex and the position error is bounded. The system wide position determination method utilizes accelerometers distributed on different robot links and the end-effector to determine the position of sets of multiple joints. The system wide method requires fewer accelerometers than the joint specific method to make all joint position sensors fault tolerant but is more computationally complex and has lower convergence properties. Experiments were conducted on a laboratory manipulator. Both position determination methods were shown to track the actual position satisfactorily. A controller using the position determination methods and the virtual passive torque controller was able to servo the joints to a desired position during position sensor failure.

Numerical analysis of installation damage of a pre-damaged geogrid with rectangular apertures

NASA Astrophysics Data System (ADS)

Dong, Yan-li; Guo, Hui-juan; Han, Jie; Zhang, Jun

2018-06-01

The geogrid can be damaged in the process or during construction if sufficient care is not exercised. In this study, the numerical software-FLAC was adopted to investigate the responses of pre-damaged geogrids with rectangular apertures when subjected to a uniaxial tensile load at different directions relative to the orientations of ribs in air. To simulate the combined loss of ribs and junction strength, specimens were pre-damaged by reducing certain amount of stiffness of the geogrid ribs. The geogrid ribs were modeled using beam elements jointed rigidly at nodes and subjected to tension in one direction. The numerical study demonstrated that the pre-damaged geogrid with rectangular apertures had similar responses when it was subjected to tension at the loading directions. The pre-damaged geogrids under 30° tension are the most sensitivity to the damage. With the increase of the degree of damage, the tensile strengths decreased relative quickly. An increase of the degree of installation damage of ribs decreased the tensile strength/stiffness of the geogrid with rectangular apertures. A higher reduction factor RFID due to installation damage is suggested when the geogrid is subjected to 30° tension relative to the orientation of ribs.

Evaluation of a Veress needle for the fluid egress system of stifle arthroscopy in toy dog breeds.

PubMed

Cha, Jae-Gwan; Lee, Hae Beom; Cheong, Hye-Yeon; Heo, Su-Young; Ragetly, Guillaume R

2016-01-01

The aim of this study was to evaluate the use of a Veress needle as a fluid egress system for stifle arthroscopy in toy dog breeds. Cadaveric canine stifle joints (n = 32) were prepared to induce an artificial intra-articular haemorrhagic effect, followed by stifle arthroscopy. The stifles were randomly assigned to one of three groups, and a fluid egress portal was established using a Veress needle (VN), a standard egress cannula (SE), or an intravenous catheter stylet (CS). Time to establish the egress portal, arthroscopic visibility, and egress portal performance were evaluated during the arthroscopy. After the arthroscopic examinations, iatrogenic cartilage lesions were identified and analysed using the percentage area of cartilage damage (%ACD). The overall arthroscopic visibility and egress portal performance were not significantly different among the groups. The egress portal establishment was faster for the VN (33 sec) and the CS (34 sec) groups than for the SE (43 sec) group (p = 0.001). On gross joint examination, no iatrogenic laceration was found in the VN group, whereas four out of 10 of the SE and two out of 10 of the CS specimens had linear cartilage excoriation on the stifle joints. The %ACD score of the VN group was lower than those of the SE group (p = 0.009) and the CS group (p = 0.001). The Veress needle method used in this study was useful to establish a fluid egress system and limit iatrogenic cartilage excoriations. This technique could become the method of choice for stifle arthroscopy, especially in smaller dogs.

Effects of Fiber Orientation on the Frictional Properties and Damage of Regenerative Articular Cartilage Surfaces

PubMed Central

Accardi, Mario Alberto; McCullen, Seth D.; Callanan, Anthony; Chung, Sangwon; Cann, Philippa M.

2013-01-01

Articular cartilage provides a low-friction, wear-resistant surface for diarthrodial joints. Due to overloading and overuse, articular cartilage is known to undergo significant wear and degeneration potentially resulting in osteoarthritis (OA). Regenerative medicine strategies offer a promising solution for the treatment of articular cartilage defects and potentially localized early OA. Such strategies rely on the development of materials to restore some aspects of cartilage. In this study, microfibrous poly(ɛ-caprolactone) scaffolds of varying fiber orientations (random and aligned) were cultured with bovine chondrocytes for 4 weeks in vitro, and the mechanical and frictional properties were evaluated. Mechanical properties were quantified using unconfined compression and tensile testing techniques. Frictional properties were investigated at physiological compressive strains occurring in native articular cartilage. Scaffolds were sheared along the fiber direction, perpendicular to the fiber direction and in random orientation. The evolution of damage as a result of shear was evaluated via white light interferometry and scanning electron microscopy. As expected, the fiber orientation strongly affected the tensile properties as well as the compressive modulus of the scaffolds. Fiber orientation did not significantly affect the equilibrium frictional coefficient, but it was, however, a key factor in dictating the evolution of surface damage on the surface. Scaffolds shear tested perpendicular to the fiber orientation displayed the highest surface damage. Our results suggest that the fiber orientation of the scaffold implanted in the joint could strongly affect its resistance to damage due to shear. Scaffold fiber orientation should thus be carefully considered when using microfibrous scaffolds. PMID:23688110

Evaluation of pipe-type cable joint restraint systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silver, D.A.; Seman, G.W.

1990-03-01

the purpose of this project was to evaluate two systems for restraining the movement of 345kV high-pressure oil-filled (HPOF) cable joints during load cycling. Problems with joints and adjacent cables due to thermomechanical bending (TMB) experienced by the Consolidated Edison Company of New York and Public Service Electric Gas Company of New Jersey are reviewed. Some approaches to reducing or preventing TMB induced damage to HPOF pipe type cable joints are discussed. The design and operation of a special test apparatus for simulating TMB effects under laboratory conditions is described. One of the two joint restraint systems evaluated under thismore » project was developed by PSE G and employed wedging devices, which could be retrofitted into existing installations, that limited the longitudinal movement of the joints during load cycling. The other system developed by Pirelli Cable Corporation applied the restraining force to the cylindrical portion of the hand applied joint insulation by means of support spiders and steel rods attached to the reducer faces. The test results show that the PSE G restraint system can effectively limit joint longitudinal movement while causing a minimal amount of mechanical disturbance to the joint stress cones. The test results obtained with the PCC system are inconclusive and indicate that further refinement and testing are required to demonstrate the effectiveness of this promising joint restraint system.« less

Virtual Passive Controller for Robot Systems Using Joint Torque Sensors

NASA Technical Reports Server (NTRS)

Aldridge, Hal A.; Juang, Jer-Nan

1997-01-01

This paper presents a control method based on virtual passive dynamic control that will stabilize a robot manipulator using joint torque sensors and a simple joint model. The method does not require joint position or velocity feedback for stabilization. The proposed control method is stable in the sense of Lyaponov. The control method was implemented on several joints of a laboratory robot. The controller showed good stability robustness to system parameter error and to the exclusion of nonlinear dynamic effects on the joints. The controller enhanced position tracking performance and, in the absence of position control, dissipated joint energy.

Influence of arthritis and non-arthritis related factors on areal bone mineral density (BMDa) in women with longstanding inflammatory polyarthritis: a primary care based inception cohort.

PubMed

Pye, Stephen R; Marshall, Tarnya; Gaffney, Karl; Silman, Alan J; Symmons, Deborah P M; O'Neill, Terence W

2010-05-28

The aim of this analysis was to determine the relative influence of disease and non-disease factors on areal bone mineral density (BMDa) in a primary care based cohort of women with inflammatory polyarthritis. Women aged 16 years and over with recent onset inflammatory polyarthritis were recruited to the Norfolk Arthritis Register (NOAR) between 1990 and 1993. Subjects were examined at both baseline and follow up for the presence of tender, swollen and deformed joints. At the 10th anniversary visit, a sub-sample of women were invited to complete a bone health questionnaire and attend for BMDa (Hologic, QDR 4000). Linear regression was used to examine the association between BMDa with both (i) arthritis-related factors assessed at baseline and the 10th anniversary visit and (ii) standard risk factors for osteoporosis. Adjustments were made for age. 108 women, mean age 58.0 years were studied. Older age, decreasing weight and BMI at follow up were all associated with lower BMDa at both the spine and femoral neck. None of the lifestyle factors were linked. Indices of joint damage including 10th anniversary deformed joint count and erosive joint count were the arthritis-related variables linked with a reduction in BMDa at the femoral neck. By contrast, disease activity as determined by the number of tender and or swollen joints assessed both at baseline and follow up was not linked with BMDa at either site. Cumulative disease damage was the strongest predictor of reduced femoral bone density. Other disease and lifestyle factors have only a modest influence.

Effects of Methylsulfonylmethane (MSM) on exercise-induced oxidative stress, muscle damage, and pain following a half-marathon: a double-blind, randomized, placebo-controlled trial.

PubMed

Withee, Eric D; Tippens, Kimberly M; Dehen, Regina; Tibbitts, Deanne; Hanes, Douglas; Zwickey, Heather

2017-01-01

Oxidative stress and muscle damage occur during exhaustive bouts of exercise, and many runners report pain and soreness as major influences on changes or breaks in training regimens, creating a barrier to training persistence. Methylsulfonylmethane (MSM) is a sulfur-based nutritional supplement that is purported to have pain and inflammation-reducing effects. To investigate the effects of MSM in attenuating damage associated with physical exertion, this randomized, double-blind, placebo-controlled study evaluated the effects of MSM supplementation on exercise-induced pain, oxidative stress and muscle damage. Twenty-two healthy females ( n  = 17) and males ( n  = 5) (age 33.7 ± 6.9 yrs.) were recruited from the 2014 Portland Half-Marathon registrant pool. Participants were randomized to take either MSM (OptiMSM®) ( n  = 11), or a placebo ( n  = 11) at 3 g/day for 21 days prior to the race and for two days after (23 total). Participants provided blood samples for measurement of markers of oxidative stress, and completed VAS surveys for pain approximately one month prior to the race (T 0 ), and at 15 min (T 1 ), 90 min (T 2 ), 1 Day (T 3 ), and 2 days (T 4 ) after race finish. The primary outcome measure 8-hydroxy-2-deoxyguanine (8-OHdG) measured oxidative stress. Secondary outcomes included malondialdehyde (MDA) for oxidative stress, creatine kinase (CK) and lactate dehydrogenase (LDH) as measures of muscle damage, and muscle (MP) and joint pain (JP) recorded using a 100 mm Visual Analogue Scale (VAS). Data were analyzed using repeated and multivariate ANOVAs, and simple contrasts compared post-race time points to baseline, presented as mean (SD) or mean change (95% CI) where appropriate. Running a half-marathon induced significant increases in all outcome measures ( p  < 0.001). From baseline, 8-OHdG increased significantly at T 1 by 1.53 ng/mL (0.86-2.20 ng/mL CI, p  < 0.001) and T 2 by 1.19 ng/mL (0.37-2.01 ng/mL CI, p  < 0.01), and fell below baseline levels at T 3 by -0.46 ng/mL (-1.18-0.26 CI, p  > 0.05) and T 4 by -0.57 ng/mL (-1.27-0.13 CI, p  > 0.05). MDA increased significantly at T 1 by 7.3 μM (3.9-10.7 CI, p  < 0.001). Muscle damage markers CK and LDH saw significant increases from baseline at all time-points ( p  < 0.01). Muscle and joint pain increased significantly from baseline at T 1 , T 2 , and T 3 ( p  < 0.01) and returned to baseline levels at T 4 . Time-by-treatment results did not reach statistical significance for any outcome measure, however, the MSM group saw clinically significant (Δ > 10 mm) reductions in both muscle and joint pain. Participation in a half-marathon was associated with increased markers of oxidative stress, muscle damage, and pain. MSM supplementation was not associated with a decrease from pre-training levels of oxidative stress or muscle damage associated with an acute bout of exercise. MSM supplementation attenuated post-exercise muscle and joint pain at clinically, but not statistically significant levels.

Radiographic Severity of Rheumatoid Arthritis in African-Americans: Results from the CLEAR Registry

PubMed Central

Bridges, S. Louis; Causey, Zenoria L.; Burgos, Paula I.; Huynh, B. Quynh N.; Hughes, Laura B.; Danila, Maria I.; van Everdingen, Amalia; Ledbetter, Stephanie; Conn, Doyt L.; Tamhane, Ashutosh; Westfall, Andrew O.; Jonas, Beth L.; Callahan, Leigh F.; Smith, Edwin A.; Brasington, Richard; Moreland, Larry W.; Alarcón, Graciela S.; van der Heijde, Désirée M.

2010-01-01

Objective To describe radiographic changes in African-Americans with rheumatoid arthritis (RA) from the CLEAR (Consortium for the Longitudinal Evaluation of African-Americans with Early Rheumatoid Arthritis) Registry, a multicenter observational study. Methods Self-declared African-American patients, were enrolled in CLEAR I, a longitudinal cohort of early RA (disease duration <2 years) from 2000 to 2005; or in CLEAR II, a cross-sectional cohort (any disease duration), from 2006 to the present. Demographic and clinical data were obtained, and sets of hand/wrist and foot radiographs were scored using the modified Sharp/van der Heijde scoring system. Results A total of 357 and 418 patients, respectively, have been enrolled into CLEAR I and CLEAR II. We report here an interim analysis of radiographic severity in these patients. For the CLEAR I cohort, 294 patients had a mean radiographic score of 2.89 at the baseline visit; 32.0% showed either erosions (25.9%) or joint space narrowing (JSN) (19.4%). At the 36-month visit the mean score was 5.65; 44.2% had erosions, 41.5% JSN and 55.4% had either. Among those patients without radiographic damage at baseline, 18.9% had progressed at the 36-month visit, compared to 57.1% of those with baseline damage (p<0.0001). For the CLEAR II cohort, 167 patients with RA of any duration, 65.3% exhibited joint erosions, 65.3% JSN and 74.8% exhibited either. The mean radiographic score was 33.42. Conclusion This is the largest radiographic study of African American RA patients. Damage occurs early in the disease and is associated with radiographic progression at 3 years of disease duration. The CLEAR Registry will provide a valuable resource for future analyses of genetic, clinical, and environmental factors associated with radiographic severity of RA in African-Americans. PMID:20461784

Tibial coverage, meniscus position, size and damage in knees discordant for joint space narrowing – data from the Osteoarthritis Initiative

PubMed Central

Bloecker, K.; Guermazi, A.; Wirth, W.; Benichou, O.; Kwoh, C.K.; Hunter, D.J.; Englund, M.; Resch, H.; Eckstein, F.

2013-01-01

SUMMARY Introduction Meniscal extrusion is thought to be associated with less meniscus coverage of the tibial surface, but the association of radiographic disease stage with quantitative measures of tibial plateau coverage is unknown. We therefore compared quantitative and semi-quantitative measures of meniscus position and morphology in individuals with bilateral painful knees discordant on medial joint space narrowing (mJSN). Methods A sample of 60 participants from the first half (2,678 cases) of the Osteoarthritis Initiative cohort fulfilled the inclusion criteria: bilateral frequent pain, Osteoarthritis Research Society International (OARSI) mJSN grades 1–3 in one, no-JSN in the contra-lateral (CL), and no lateral JSN in either knee (43 unilateral mJSN1; 17 mJSN2/3; 22 men, 38 women, body mass index (BMI) 31.3 ± 3.9 kg/m2). Segmentation and three-dimensional quantitative analysis of the tibial plateau and meniscus, and semi-quantitative evaluation of meniscus damage (magnetic resonance imaging (MRI) osteoarthritis knee score – MOAKS) was performed using coronal 3T MR images (MPR DESSwe and intermediate-weighted turbo spin echo (IW-TSE) images). CL knees were compared using paired t-tests (between-knee, within-person design). Results Medial tibial plateau coverage was 36 ± 9% in mJSN1 vs 45 ± 8% in CL no-JSN knees, and was 31 ± 9% in mJSN2/3 vs 46 ± 6% in no-JSN knees (both P < 0.001). mJSN knees showed greater meniscus extrusion and damage (MOAKS), but no significant difference in meniscus volume. No significant differences in lateral tibial coverage, lateral meniscus morphology or position were observed. Conclusions Knees with medial JSN showed substantially less medial tibial plateau coverage by the meniscus. We suggest that the less meniscal coverage, i.e., less mechanical protection may be a reason for greater rates of cartilage loss observed in JSN knees. PMID:23220556

[Joint dislocation after total knee arthroplasty as an ankle fracture complication. Case report].

PubMed

Hrubina, M; Skoták, M

2012-01-01

Joint dislocation after total knee arthroplasty is a rare complication. It is described as the result of ligamentous instability. Here we report the case of an 82-year-old women who underwent primary total knee arthroplasty (TKA) for advanced primary grade III gonarthrosis. At 3 post-operative months the joint was stable and painless, with radiographic evidence of good TKA alignment and integration. At 4 months the patient suffered injury to the ankle involving a bimalleolar fracture and damage to knee soft tissues. The fracture was surgically treated. Subsequently, dorsal tibial dislocation was manifested. This was managed by individual intramedullary nail arthrodesis. At 8 months following the operation, the knee condition was satisfactory, with rigid arthrodesis and leg shortening of 4 cm. The patient was satisfied because she was free of pain and able to walk. Arthrodesis of the knee joint with an individual nail is an option for a definitive treatment of TKA instability. When other joints, such as ankle or hip joints, are injured, it is recommended to pay attention also to any TKA implanted previously because of potential development of instability or infection.

Musculoskeletal disease burden of hereditary hemochromatosis.

PubMed

Sahinbegovic, Enijad; Dallos, Tomáš; Aigner, Elmar; Axmann, Roland; Manger, Bernhard; Englbrecht, Matthias; Schöniger-Hekele, Maximilian; Karonitsch, Thomas; Stamm, Tanja; Farkas, Martin; Karger, Thomas; Stölzel, Ulrich; Keysser, Gernot; Datz, Christian; Schett, Georg; Zwerina, Jochen

2010-12-01

To determine the prevalence, clinical picture, and disease burden of arthritis in patients with hereditary hemochromatosis. In this cross-sectional observational study of 199 patients with hemochromatosis and iron overload, demographic and disease-specific variables, genotype, and organ involvement were recorded. The prevalence, intensity, and localization of joint pain were assessed, and a complete rheumatologic investigation was performed. Radiographs of the hands, knees, and ankles were scored for joint space narrowing, erosions, osteophytes, and chondrocalcinosis. In addition, the number and type of joint replacement surgeries were recorded. Joint pain was reported by 72.4% of the patients. Their mean ± SD age at the time of the initial joint symptoms was 45.8 ± 13.2 years. If joint pain was present, it preceded the diagnosis of hemochromatosis by a mean ± SD of 9.0 ± 10.7 years. Bony enlargement was observed in 65.8% of the patients, whereas synovitis was less common (13.6%). Joint space narrowing and osteophytes as well as chondrocalcinosis of the wrist and knee joints were frequent radiographic features of hemochromatosis. Joint replacement surgery was common, with 32 patients (16.1%) undergoing total joint replacement surgery due to severe OA. The mean ± SD age of these patients was 58.3 ± 10.4 years at time of joint replacement surgery. Female sex, metacarpophalangeal joint involvement, and the presence of chondrocalcinosis were associated with a higher risk of early joint failure (i.e., the need for joint replacement surgery). Arthritis is a frequent, early, and severe symptom of hemochromatosis. Disease is not confined to involvement of the metacarpophalangeal joints and often leads to severe damage requiring the replacement of joints. Copyright © 2010 by the American College of Rheumatology.

Assessment of precast beam-column using capacity demand response spectrum subject to design basis earthquake and maximum considered earthquake

NASA Astrophysics Data System (ADS)

Ghani, Kay Dora Abd.; Tukiar, Mohd Azuan; Hamid, Nor Hayati Abdul

2017-08-01

Malaysia is surrounded by the tectonic feature of the Sumatera area which consists of two seismically active inter-plate boundaries, namely the Indo-Australian and the Eurasian Plates on the west and the Philippine Plates on the east. Hence, Malaysia experiences tremors from far distant earthquake occurring in Banda Aceh, Nias Island, Padang and other parts of Sumatera Indonesia. In order to predict the safety of precast buildings in Malaysia under near field ground motion the response spectrum analysis could be used for dealing with future earthquake whose specific nature is unknown. This paper aimed to develop of capacity demand response spectrum subject to Design Basis Earthquake (DBE) and Maximum Considered Earthquake (MCE) in order to assess the performance of precast beam column joint. From the capacity-demand response spectrum analysis, it can be concluded that the precast beam-column joints would not survive when subjected to earthquake excitation with surface-wave magnitude, Mw, of more than 5.5 Scale Richter (Type 1 spectra). This means that the beam-column joint which was designed using the current code of practice (BS8110) would be severely damaged when subjected to high earthquake excitation. The capacity-demand response spectrum analysis also shows that the precast beam-column joints in the prototype studied would be severely damaged when subjected to Maximum Considered Earthquake (MCE) with PGA=0.22g having a surface-wave magnitude of more than 5.5 Scale Richter, or Type 1 spectra.

Crystal-proven Gout and Characteristic Gout Severity Factors are Associated with Cardiovascular Disease.

PubMed

Disveld, Iris J M; Fransen, Jaap; Rongen, Gerard A; Kienhorst, Laura B E; Zoakman, Sahel; Janssens, Hein J E M; Janssen, Matthijs

2018-04-15

Our aim was to examine the prevalence of cardiovascular disease (CVD) in patients with crystal-proven gout compared to arthritis controls. Further, we analyzed the association between characteristic gout severity factors and CVD to provide further support for a pathogenetic relationship between gout and CVD. Patients with arthritis referred for diagnosis were consecutively included in the Gout Arnhem-Liemers cohort. Joint fluid analysis was performed in all referred patients; controls were negative for crystals. Patients' characteristics and different manifestations of CVD and gout severity factors (disease duration, attack frequency, tophi, affected joints, high serum urate acid level, joint damage) were collected. Gout patients were compared with controls for the prevalence of CVD. In addition, the association between characteristic gout severity factors and presence of CVD was analyzed. Data from 700 gout patients and 276 controls were collected. CVD was present in 47% (95% CI 44%-51%) and 24% (95% CI 19%-29%) of gout patients and controls, respectively. Corrected for confounders, gout was still strongly associated with an increased prevalence of CVD compared to controls (OR 3.39, 95% CI 2.37-4.84). In patients with gout, disease duration ≥ 2 years, oligo- or polyarthritis, serum urate acid > 0.55 mmol/l at presentation, and joint damage were independently (p < 0.05) associated with prevalent CVD. Crystal-proven gout was strongly associated with an increased prevalence of CVD. In patients with gout, characteristic gout severity factors were associated with CVD.

Clinical application of arthroscopy in the diagnosis and treatment of anterior impingement syndrome of the ankle joint in physical workers.

PubMed

Wu, Wen-Te; Chen, Zhi-Wei; Zhou, Yu-Cheng

2012-10-01

To evaluate the clinical application of arthroscopy in the diagnosis and treatment of anterior impingement syndrome of the ankle joint in physical workers. A retrospective study was carried out at the Department of Orthopedics, the First Hospital affiliated to Nanhua University, Hengyang, China from March 2005 to December 2011. Seventeen cases of anterior impingement syndrome of the ankle joint were confirmed, and treated through arthroscopy. All these patients conformed to regular follow-up postoperatively, and clinical details, as well as postoperative prognosis were retrieved and analyzed retrospectively. The efficacy was evaluated by the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot-ankle scoring system, and pain relief was assessed by visual analogue scoring (VAS). Anterolateral impingement syndrome was found in 11 patients, anteromedial impingement syndrome in 4, while anterior impingement syndrome in 2 via arthroscopic examination. The VAS was reduced from 5.2-1.1, and the AOFAS score was elevated from 76.4-95.8 postoperatively; both of which demonstrated statistical differences when compared to preoperative scores. It was also found that concomitant cartilage damage was an indicator of poor prognosis in arthroscopic treatment of impingement syndrome of the ankle joint. Satisfactory results could be achieved for physical workers with anterior impingement syndrome treated by arthroscopy. As the cartilage damage is an indicator of poor prognosis, an early operation is advocated when the prognosis of anterior impingement syndrome is confirmed.

Outcome predictors of intra-articular glucocorticoid treatment for knee synovitis in patients with rheumatoid arthritis - a prospective cohort study.

PubMed

Weitoft, Tomas; Rönnelid, Johan; Knight, Ann; Lysholm, Jörgen; Saxne, Tore; Larsson, Anders

2014-06-20

Intra-articular glucocorticoid treatment (IAGC) is widely used for symptom relief in arthritis. However, knowledge of factors predicting treatment outcome is limited. The aim of the present study was to identify response predictors of IAGC for knee synovitis in patients with rheumatoid arthritis (RA). In this study 121 RA patients with synovitis of the knee were treated with intra-articular injections of 20 mg triamcinolone hexacetonide. They were followed for six months and the rate of clinical relapse was studied. Non-responders (relapse within 6 months) and responders were compared regarding patient characteristics and knee joint damage as determined by the Larsen-Dale index. In addition, matched samples of serum and synovial fluid were analysed for factors reflecting the inflammatory process (C-reactive protein, interleukin 6, tumour necrosis factor alpha, vascular endothelial growth factor), joint tissue turnover (cartilage oligomeric matrix protein, metalloproteinase 3), and autoimmunity (antinuclear antibodies, antibodies against citrullinated peptides, rheumatoid factor). During the observation period, 48 knees relapsed (40%). Non-responders had more radiographic joint damage than responders (P = 0.002) and the pre-treatment vascular endothelial growth factor (VEGF) level in synovial fluid was significantly higher in non-responders (P = 0.002). Joint destruction is associated with poor outcome of IAGC for knee synovitis in RA. In addition, higher levels of VEGF in synovial fluid are found in non-responders, suggesting that locally produced VEGF is a biomarker for recurrence of synovial hyperplasia and the risk for arthritis relapse.

Analysis of Bonded Joints Between the Facesheet and Flange of Corrugated Composite Panels

NASA Technical Reports Server (NTRS)

Yarrington, Phillip W.; Collier, Craig S.; Bednarcyk, Brett A.

2008-01-01

This paper outlines a method for the stress analysis of bonded composite corrugated panel facesheet to flange joints. The method relies on the existing HyperSizer Joints software, which analyzes the bonded joint, along with a beam analogy model that provides the necessary boundary loading conditions to the joint analysis. The method is capable of predicting the full multiaxial stress and strain fields within the flange to facesheet joint and thus can determine ply-level margins and evaluate delamination. Results comparing the method to NASTRAN finite element model stress fields are provided illustrating the accuracy of the method.

Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays

PubMed Central

Guetterman, Timothy C.; Fetters, Michael D.; Creswell, John W.

2015-01-01

PURPOSE Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. METHODS We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. RESULTS The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. CONCLUSIONS Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. PMID:26553895

NASA airframe structural integrity program

NASA Technical Reports Server (NTRS)

Harris, Charles E.

1991-01-01

NASA has initiated a research program with the long-term objective of supporting the aerospace industry in addressing issues related to the aging commercial transport fleet. The interdisciplinary program combines advanced fatigue crack growth prediction methodology with innovative nondestructive examination technology with the focus on multi-site damage (MSD) at riveted connections. A fracture mechanics evaluation of the concept of pressure proof testing the fuselage to screen for MSD has been completed. Also, a successful laboratory demonstration of the ability of the thermal flux method to detect disbonds at riveted lap splice joints has been conducted. All long-term program elements have been initiated and the plans for the methodology verification program are being coordinated with the airframe manufacturers.

NASA airframe structural integrity program

NASA Technical Reports Server (NTRS)

Harris, Charles E.

1990-01-01

NASA initiated a research program with the long-term objective of supporting the aerospace industry in addressing issues related to the aging of the commercial transport fleet. The program combines advanced fatigue crack growth prediction methodology with innovative nondestructive examination technology with the focus on multi-stage damage (MSD) at rivited connections. A fracture mechanics evaluation of the concept of pressure proof testing the fuselage to screen for MSD was completed. A successful laboratory demonstration of the ability of the thermal flux method to detect disbonds at rivited lap splice joints was conducted. All long-term program elements were initiated, and the plans for the methodology verification program are being coordinated with the airframe manufacturers.

The tether inspection and repair experiment (TIRE)

NASA Technical Reports Server (NTRS)

Wood, George M.; Loria, Alberto; Harrison, James K.

1988-01-01

The successful development and deployment of reusable tethers for space applications will require methods for detecting, locating, and repairing damage to the tether. This requirement becomes especially important whenever the safety of the STS or the Space Station may be diminished or when critical supplies or systems would be lost in the event of a tether failure. A joint NASA/PSN study endeavor has recently been initiated to evaluate and address the problems to be solved for such an undertaking. The objectives of the Tether Inspection and Repair Experiment (TIRE) are to develop instrumentation and repair technology for specific classes of tethers defined as standards, and to demonstrate the technologies in ground-based and in-flight testing on the STS.

Histochemistry as a Unique Approach for Investigating Normal and Osteoarthritic Cartilage

PubMed Central

Musumeci, G.; Castrogiovanni, P.; Mazzone, V.; Szychlinska, M. A.; Castorina, S.; Loreto, C.

2014-01-01

In this review article, we describe benefits and disadvantages of the established histochemical methods for studying articular cartilage tissue under normal, pathological and experimental conditions. We illustrate the current knowledge on cartilage tissue based on histological and immunohistochemical aspects, and in conclusion we provide a short overview on the degeneration of cartilage, such as osteoarthritis. Adult articular cartilage has low capacity to repair itself, and thus even minor injuries may lead to progressive damage and osteoarthritic joint degeneration, resulting in significant pain and disability. Numerous efforts have been made to implement the knowledge in the study of cartilage in the last years, and histochemistry proved to be an especially powerful tool to this aim. PMID:24998926

Techniques of Force and Pressure Measurement in the Small Joints of the Wrist.

PubMed

Schreck, Michael J; Kelly, Meghan; Canham, Colin D; Elfar, John C

2018-01-01

The alteration of forces across joints can result in instability and subsequent disability. Previous methods of force measurements such as pressure-sensitive films, load cells, and pressure-sensing transducers have been utilized to estimate biomechanical forces across joints and more recent studies have utilized a nondestructive method that allows for assessment of joint forces under ligamentous restraints. A comprehensive review of the literature was performed to explore the numerous biomechanical methods utilized to estimate intra-articular forces. Methods of biomechanical force measurements in joints are reviewed. Methods such as pressure-sensitive films, load cells, and pressure-sensing transducers require significant intra-articular disruption and thus may result in inaccurate measurements, especially in small joints such as those within the wrist and hand. Non-destructive methods of joint force measurements either utilizing distraction-based joint reaction force methods or finite element analysis may offer a more accurate assessment; however, given their recent inception, further studies are needed to improve and validate their use.

Human ossicular-joint flexibility transforms the peak amplitude and width of impulsive acoustic stimulia)

PubMed Central

Gottlieb, Peter K.; Vaisbuch, Yona

2018-01-01

The role of the ossicular joints in the mammalian middle ear is still debated. This work tests the hypothesis that the two synovial joints filter potentially damaging impulsive stimuli by transforming both the peak amplitude and width of these impulses before they reach the cochlea. The three-dimensional (3D) velocity along the ossicular chain in unaltered cadaveric human temporal bones (N = 9), stimulated with acoustic impulses, is measured in the time domain using a Polytec (Waldbronn, Germany) CLV-3D laser Doppler vibrometer. The measurements are repeated after fusing one or both of the ossicular joints with dental cement. Sound transmission is characterized by measuring the amplitude, width, and delay of the impulsive velocity profile as it travels from the eardrum to the cochlea. On average, fusing both ossicular joints causes the stapes velocity amplitude and width to change by a factor of 1.77 (p = 0.0057) and 0.78 (p = 0.011), respectively. Fusing just the incudomalleolar joint has a larger effect on amplitude (a factor of 2.37), while fusing just the incudostapedial joint decreases the stapes velocity on average. The 3D motion of the ossicles is altered by fusing the joints. Finally, the ability of current computational models to predict this behavior is also evaluated.

Derivation and test of elevated temperature thermal-stress-free fastener concept

NASA Technical Reports Server (NTRS)

Sawyer, J. W.; Blosser, M. L.; Mcwithey, R. R.

1985-01-01

Future aerospace vehicles must withstand high temperatures and be able to function over a wide temperature range. New composite materials are being developed for use in designing high-temperature lightweight structures. Due to the difference between coefficients of thermal expansion for the new composite materials and conventional high-temperature metallic fasteners, innovative joining techniques are needed to produce tight joints at all temperatures without excessive thermal stresses. A thermal-stress-free fastening technique is presented that can be used to provide structurally tight joints at all temperatures even when the fastener and joined materials have different coefficients of thermal expansion. The derivation of thermal-stress-free fasteners and joint shapes is presented for a wide variety of fastener materials and materials being joined together. Approximations to the thermal-stress-free shapes that result in joints with low-thermal-stresses and that simplify the fastener/joint shape are discussed. The low-thermal-stress fastener concept is verified by thermal and shear tests in joints using oxide-dispersion-strengthened alloy fasteners in carbon-carbon material. The test results show no evidence of thermal stress damage for temperatures up to 2000 F and the resulting joints carried shear loads at room temperature typical of those for conventional joints.

Evaluation of a new methodology to simulate damage and wear of polyethylene hip replacements subjected to edge loading in hip simulator testing.

PubMed

Partridge, Susan; Tipper, Joanne L; Al-Hajjar, Mazen; Isaac, Graham H; Fisher, John; Williams, Sophie

2018-05-01

Wear and fatigue of polyethylene acetabular cups have been reported to play a role in the failure of total hip replacements. Hip simulator testing under a wide range of clinically relevant loading conditions is important. Edge loading of hip replacements can occur following impingement under extreme activities and can also occur during normal gait, where there is an offset deficiency and/or joint laxity. This study evaluated a hip simulator method that assessed wear and damage in polyethylene acetabular liners that were subjected to edge loading. The liners tested to evaluate the method were a currently manufactured crosslinked polyethylene acetabular liner and an aged conventional polyethylene acetabular liner. The acetabular liners were tested for 5 million standard walking cycles and following this 5 million walking cycles with edge loading. Edge loading conditions represented a separation of the centers of rotation of the femoral head and the acetabular liner during the swing phase, leading to loading of the liner rim on heel strike. Rim damage and cracking was observed in the aged conventional polyethylene liner. Steady-state wear rates assessed gravimetrically were lower under edge loading compared to standard loading. This study supports previous clinical findings that edge loading may cause rim cracking in liners, where component positioning is suboptimal or where material degradation is present. The simulation method developed has the potential to be used in the future to test the effect of aging and different levels of severity of edge loading on a range of cross-linked polyethylene materials. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1456-1462, 2018. © 2017 Wiley Periodicals, Inc.

Time-resolved acoustic emission tomography in the laboratory: tracking localised damage in rocks

NASA Astrophysics Data System (ADS)

Brantut, N.

2017-12-01

Over the past three decades, there has been tremendous technological developments of laboratory equipment and studies using acoustic emission and ultrasonic monitoring of rock samples during deformation. Using relatively standard seismological techniques, acoustic emissions can be detected, located in space and time, and source mechanisms can be obtained. In parallel, ultrasonic velocities can be measured routinely using standard pulse-receiver techniques.Despite these major developments, current acoustic emission and ultrasonic monitoring systems are typically used separately, and the poor spatial coverage of acoustic transducers precludes performing active 3D tomography in typical laboratory settings.Here, I present an algorithm and software package that uses both passive acoustic emission data and active ultrasonic measurements to determine acoustic emission locations together with the 3D, anisotropic P-wave structure of rock samples during deformation. The technique is analogous to local earthquake tomography, but tailored to the specificities of small scale laboratory tests. The fast marching method is employed to compute the forward problem. The acoustic emission locations and the anisotropic P-wave field are jointly inverted using the Quasi-Newton method.The method is used to track the propagation of compaction bands in a porous sandstone deformed in the ductile, cataclastic flow regime under triaxial stress conditions. Near the yield point, a compaction front forms at one end of the sample, and slowly progresses towards the other end. The front is illuminated by clusters of Acoustic Emissions, and leaves behind a heavily damaged material where the P-wave speed has dropped by up to 20%.The technique opens new possibilities to track in-situ strain localisation and damage around laboratory faults, and preliminary results on quasi-static rupture in granite will be presented.

Influence of the optimization methods on neural state estimation quality of the drive system with elasticity.

PubMed

Orlowska-Kowalska, Teresa; Kaminski, Marcin

2014-01-01

The paper deals with the implementation of optimized neural networks (NNs) for state variable estimation of the drive system with an elastic joint. The signals estimated by NNs are used in the control structure with a state-space controller and additional feedbacks from the shaft torque and the load speed. High estimation quality is very important for the correct operation of a closed-loop system. The precision of state variables estimation depends on the generalization properties of NNs. A short review of optimization methods of the NN is presented. Two techniques typical for regularization and pruning methods are described and tested in detail: the Bayesian regularization and the Optimal Brain Damage methods. Simulation results show good precision of both optimized neural estimators for a wide range of changes of the load speed and the load torque, not only for nominal but also changed parameters of the drive system. The simulation results are verified in a laboratory setup.

Radiocarbon dating reveals minimal collagen turnover in both healthy and osteoarthritic human cartilage.

PubMed

Heinemeier, Katja M; Schjerling, Peter; Heinemeier, Jan; Møller, Mathias B; Krogsgaard, Michael R; Grum-Schwensen, Tomas; Petersen, Michael M; Kjaer, Michael

2016-07-06

The poor regenerative capacity of articular cartilage presents a major clinical challenge and may relate to a limited turnover of the cartilage collagen matrix. However, the collagen turnover rate during life is not clear, and it is debated whether osteoarthritis (OA) can influence it. Using the carbon-14 ((14)C) bomb-pulse method, life-long replacement rates of collagen were measured in tibial plateau cartilage from 23 persons born between 1935 and1997 (15 and 8 persons with OA and healthy cartilage, respectively). The (14)C levels observed in cartilage collagen showed that, virtually, no replacement of the collagen matrix happened after skeletal maturity and that neither OA nor tissue damage, per se, influenced collagen turnover. Regional differences in (14)C content across the joint surface showed that cartilage collagen located centrally on the joint surface is formed several years earlier than collagen located peripherally. The collagen matrix of human articular cartilage is an essentially permanent structure that has no significant turnover in adults, even with the occurrence of disease. Copyright © 2016, American Association for the Advancement of Science.

3D motion analysis of the wrist splint effect to wrist joint movement.

PubMed

Shin, Joong-Il; Park, Soo-Hee

2017-06-01

[Purpose] This study aimed to investigate the degree of straightness of the wrist joint, depending on the use of a wrist splint while opening a bottle cap. Its results may provide data for later studies on preventing accidents at workplaces and improving efficiency. [Subjects and Methods] Thirty Male and Female in their twenties who did not have hand-related diseases, fractures, or history that included neurological impairments associated with the hand were selected as subjects of the study. Wrist splints were made to fit the hand and lower arm of each subject. Evaluation assignments were carried out without and with the splints after 10 minutes of rest. To analyze the wrist movement in opening the bottle cap, a three-dimensional movement analyzing system by Zebris was used. [Results] Wrist angle decreased while opening caps of four different diameters while wearing splints, but not when splints were not worn. This means that wearing a splint may aid weakened wrist muscles. [Conclusion] Future studies should be conducted among subjects with damaged wrist muscles and evaluate the subjects in actual workplaces to obtain more objective and more valid data.

The Influence of PV Module Materials and Design on Solder Joint Thermal Fatigue Durability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bosco, Nick; Silverman, Timothy J.; Kurtz, Sarah

Finite element model (FEM) simulations have been performed to elucidate the effect of flat plate photovoltaic (PV) module materials and design on PbSn eutectic solder joint thermal fatigue durability. The statistical method of Latin Hypercube sampling was employed to investigate the sensitivity of simulated damage to each input variable. Variables of laminate material properties and their thicknesses were investigated. Using analysis of variance, we determined that the rate of solder fatigue was most sensitive to solder layer thickness, with copper ribbon and silicon thickness being the next two most sensitive variables. By simulating both accelerated thermal cycles (ATCs) and PVmore » cell temperature histories through two characteristic days of service, we determined that the acceleration factor between the ATC and outdoor service was independent of the variables sampled in this study. This result implies that an ATC test will represent a similar time of outdoor exposure for a wide range of module designs. This is an encouraging result for the standard ATC that must be universally applied across all modules.« less

[Modified Cheng's Juanbi Decoction downregulates expression of prostaglandin E receptor 4 in synovial tissue in rats with adjuvant arthritis].

PubMed

Xu, Xia; Cheng, Hui; Cao, Jian; DU, Huan; Meng, Qingwei; Guo, Mengyuan

2017-06-01

Objective To investigate the effect of modified Cheng's Juanbi Decoction on the expression of prostaglandin E receptor 4 (PTGER4), the T cell receptor in the synovial tissues, in rats with adjuvant arthritis (AA). Methods A rat model of AA was established by subcutaneous injection of Freund's complete adjuvant at the vola pedis combined with ice-water bath and blowing. The degree of joint swelling and arthritis index were determined in each group. The quantitative real-time PCR was performed to assess the effect of modified Cheng's Juanbi Decoction on the mRNA expression of PTGER4in the synovial tissue. Results Cheng's Juanbi Decoction significantly alleviated the damage in the joints and synovial tissues in the AA rats. High-dose (the content of crude drug: 4 g/mL) Cheng's Juanbi Decoction significantly reduced the mRNA expression of PTGER4 in the synovial tissues. Conclusion Cheng's Juanbi Decoction can reduce the level of PTGER4 mRNA in the synovial tissue in AA rats.

Nonlinear Wave Mixing Technique for Nondestructive Assessment of Infrastructure Materials

NASA Astrophysics Data System (ADS)

Ju, Taeho

To operate safely, structures and components need to be inspected or monitored either periodically or in real time for potential failure. For this purpose, ultrasonic nondestructive evaluation (NDE) techniques have been used extensively. Most of these ultrasonic NDE techniques utilize only the linear behavior of the ultrasound. These linear techniques are effective in detecting discontinuities in materials such as cracks, voids, interfaces, inclusions, etc. However, in many engineering materials, it is the accumulation of microdamage that leads to degradation and eventual failure of a component. Unfortunately, it is difficult for linear ultrasonic NDE techniques to characterize or quantify such damage. On the other hand, the acoustic nonlinearity parameter (ANLP) of a material is often positively correlated with such damage in a material. Thus, nonlinear ultrasonic NDE methods have been used in recently years to characterize cumulative damage such as fatigue in metallic materials, aging in polymeric materials, and degradation of cement-based materials due to chemical reactions. In this thesis, we focus on developing a suit of novel nonlinear ultrasonic NDE techniques based on the interactions of nonlinear ultrasonic waves, namely wave mixing. First, a noncollinear wave mixing technique is developed to detect localized damage in a homogeneous material by using a pair of noncollinear a longitudinal wave (L-wave) and a shear wave (S-wave). This pair of incident waves make it possible to conduct NDE from a single side of the component, a condition that is often encountered in practical applications. The proposed noncollinear wave mixing technique is verified experimentally by carrying out measurements on aluminum alloy (AA 6061) samples. Numerical simulations using the Finite Element Method (FEM) are also conducted to further demonstrate the potential of the proposed technique to detect localized damage in structural components. Second, the aforementioned nonlinear mixing technique is adapted to develop an NDE technique for characterizing thermal aging of adhesive joints. To this end, a nonlinear spring model is used to simulate the effect of the adhesive layer. Based on this nonlinear spring model, analytical expressions of the resonant wave generated by the adhesive layers is obtained through an asymptotic analysis when the adhesive layer thickness is much smaller than the pertinent wavelength. The solutions are expressed in terms of the properties of the adhesive layer. The nonlinear spring model shows a good agreement with the finite layer model solutions in the limit of a small thickness to wavelength ratio. Third, to demonstrate the effectiveness of this newly developed technique, measurements are conducted on adhesive joint samples made of two aluminum adherends bonded together by a polymer adhesive tape. The samples are aged in a thermal chamber to induce thermal ageing degradation in the adhesive layer. Using the developed wave-mixing technique in conjunction with the nonlinear spring model, we show that the thermal aging damage of the adhesive layer can be quantified from only one side of the sample. Finally, by mixing two L-waves, we develop a mixing technique to nondestructively evaluate the damage induced by alkali-silica reaction (ASR) in concrete. Experimental measurements are conducted on concrete prism samples that contain reactive aggregates and have been subjected to different ASR conditioning. This new technique takes into consideration of the significant attenuation caused by ASR-induced microcracks and scattering by the aggregates. The measurement results show that the ANLP has a much greater sensitivity to ASR damage than other parameters such as attenuation and wave speed. More remarkably, it is also found that the measured acoustic nonlinearity parameter is well-correlated with the reduction of the compressive strength induced by ASR damage. Thus, ANLP can be used to nondestructively track ASR damage in concrete.

Saposin C Coupled Lipid Nanovesicles Specifically Target Arthritic Mouse Joints for Optical Imaging of Disease Severity

PubMed Central

Qi, Xiaoyang; Flick, Matthew J.; Frederick, Malinda; Chu, Zhengtao; Mason, Rachel; DeLay, Monica; Thornton, Sherry

2012-01-01

Rheumatoid arthritis is a chronic inflammatory disease affecting approximately 1% of the population and is characterized by cartilage and bone destruction ultimately leading to loss of joint function. Early detection and intervention of disease provides the best hope for successful treatment and preservation of joint mobility and function. Reliable and non-invasive techniques that accurately measure arthritic disease onset and progression are lacking. We recently developed a novel agent, SapC-DOPS, which is composed of the membrane-associated lysosomal protein saposin C (SapC) incorporated into 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) lipid nanovesicles. SapC-DOPS has a high fusogenic affinity for phosphatidylserine-enriched microdomains on surfaces of target cell membranes. Incorporation of a far-red fluorophore, CellVue Maroon (CVM), into the nanovesicles allows for in vivo non-invasive visualization of the agent in targeted tissue. Given that phosphatidylserine is present only on the inner leaflet of healthy plasma membranes but is “flipped” to the outer leaflet upon cell damage, we hypothesized that SapC-DOPS would target tissue damage associated with inflammatory arthritis due to local surface-exposure of phosphatidylserine. Optical imaging with SapC-DOPS-CVM in two distinct models of arthritis, serum-transfer arthritis (e.g., K/BxN) and collagen-induced arthritis (CIA) revealed robust SapC-DOPS-CVM specific localization to arthritic paws and joints in live animals. Importantly, intensity of localized fluorescent signal correlated with macroscopic arthritic disease severity and increased with disease progression. Flow cytometry of cells extracted from arthritic joints demonstrated that SapC-DOPS-CVM localized to an average of 7–8% of total joint cells and primarily to CD11b+Gr-1+ cells. Results from the current studies strongly support the application of SapC-DOPS-CVM for advanced clinical and research applications including: detecting early arthritis onset, assessing disease progression real-time in live subjects, and providing novel information regarding cell types that may mediate arthritis progression within joints. PMID:22470501

Reliability of Tin Silver Copper and mixed solders under variable loading conditions

NASA Astrophysics Data System (ADS)

Jaradat, Younis

Industry use of lead free solder joints necessitates accurate modeling in predicting life in service. Yet, current extrapolations of accelerated test results do not actuate realistic conditions. This research focuses on joint properties of Pb-mixed and Pb-free solder alloys in order to explain material behavior subject to certain test conditions, i.e., varying cycling amplitudes. Additionally, this research will begin with extensive studies on backward compatible solder joints from the material's behavior to its reliability under displacement and load controlled fatigue tests. We address the evolution of the joint's microstructure ergo its properties and performance (mixed solder joints). The present work reports results of reflowing 30 mil SAC305 balls onto Cu, and ENIG coated BGA pads with different amounts of SnPb paste, aging and/or cycling the joints and inspecting the microstructure by cross polarizer microscopy and SEM. We found that the addition of small amounts of Pb had significant effects on solidification during cool-down from reflow, and consequently the initial microstructure. In terms of the varying cycling amplitude study, we note how realistic service conditions are almost never well approximated by cycling with fixed amplitudes. Recent results have demonstrated the consistent breakdown of common damage accumulation rules. In isothermal cycling tests the remaining life, after a step-down in amplitude, was invariably shorter than predicted by such a rule, while a step-up tended to have the opposite effect. The present work offers a mechanistic explanation for this and the basis for a practical approach to the assessment of life under service conditions. Realistic BGA joints were cycled individually in a micromechanical tester, monitoring the solder stiffness and the inelastic energy deposition. Cycling was seen to first cause rapid hardening, followed by leveling off in a 'cyclic saturation' stage and eventually the initiation and growth of a crack until failure. A temporary increase in amplitude during cycling caused a lasting reduction in hardness, and thus enhanced inelastic energy deposition and damage evolution, after the fact. This factor dominates during repeated increases and decreases, eventually shortening the remaining life dramatically

Autonomous sensing of composites with carbon nanotubes for structural health monitoring

NASA Astrophysics Data System (ADS)

Liu, Yingtao; Yekani Fard, Masoud; Rajadas, Abhishek; Chattopadhyay, Aditi

2012-04-01

The development of structural health monitoring techniques leads to the integration of sensing capability within engineering structures. This study investigates the application of multi walled carbon nanotubes in polymer matrix composites for autonomous damage detection through changes in electrical resistance. The autonomous sensing capabilities of fiber reinforced nanocomposites are studied under multiple loading conditions including tension loads. Single-lap joints with different joint lengths are tested. Acoustic emission sensing is used to validate the matrix crack propagation. A digital image correlation system is used to measure the shear strain field of the joint area. The joints with 1.5 inch length have better autonomous sensing capabilities than those with 0.5 inch length. The autonomous sensing capabilities of nanocomposites are found to be sensitive to crack propagation and can revolutionize the research on composite structural health management in the near future.

Redundant drive current imbalance problem of the Automatic Radiator Inspection Device (ARID)

NASA Technical Reports Server (NTRS)

Latino, Carl D.

1992-01-01

The Automatic Radiator Inspection Device (ARID) is a 4 Degree of Freedom (DOF) robot with redundant drive motors at each joint. The device is intended to automate the labor intensive task of space shuttle radiator inspection. For safety and redundancy, each joint is driven by two independent motor systems. Motors driving the same joint, however, draw vastly different currents. The concern was that the robot joints could be subjected to undue stress. It was the objective of this summer's project to determine the cause of this current imbalance. In addition it was to determine, in a quantitative manner, what was the cause, how serious the problem was in terms of damage or undue wear to the robot and find solutions if possible. It was concluded that most problems could be resolved with a better motor control design. This document discusses problems encountered and possible solutions.

Bonded composite to metal scarf joint performance in an aircraft landing gear drag strut. [for Boeing 747 aircraft

NASA Technical Reports Server (NTRS)

Howell, W. E.

1974-01-01

The structural performance of a boron-epoxy reinforced titanium drag strut, which contains a bonded scarf joint and was designed to the criteria of the Boeing 747 transport, was evaluated. An experimental and analytical investigation was conducted. The strut was exposed to two lifetimes of spectrum loading and was statically loaded to the tensile and compressive design ultimate loads. Throughout the test program no evidence of any damage in the drag strut was detected by strain gage measurements, ultrasonic inspection, or visual observation. An analytical study of the bonded joint was made using the NASA structural analysis computer program NASTRAN. A comparison of the strains predicted by the NASTRAN computer program with the experimentally determined values shows excellent agreement. The NASTRAN computer program is a viable tool for studying, in detail, the stresses and strains induced in a bonded joint.

Response of knee fibrocartilage to joint destabilization

PubMed Central

Dyment, N.A; Hagiwara, Y.; Jiang, X.; Huang, J.; Adams, D.J.; Rowe, D.W.

2015-01-01

Objective A major challenge to understanding osteoarthritis pathology is identifying the cellular events that precede the onset of cartilage damage. The objective of this study is to determine the effect of joint destabilization on early changes to fibrocartilage in the joint. Design/Methods The anterior cruciate ligament was transected in collagen reporter mice (Col1GFP and ColXRFP). Mineralization labels were given every two weeks to measure new mineralized cartilage apposition. Novel fluorescent histology of mineralized tissue was used to characterize the changes in fibrocartilage at 2 and 4 weeks post-injury. Results Changes in fibrocartilaginous structures of the joint occur as early as two weeks after injury and are well developed by four weeks. The alterations are seen in multiple entheses and in the medial surface of the femoral and tibial condyles. In the responding entheses, mineral apposition towards the ligament midsubstance results in thickening of the mineralize fibrocartilage. These changes are associated with increases in ColX-RFP, Col1-CFP reporter activity and alkaline phosphatase enzyme activity. Mineral apposition also occurs in the fibrocartilage of the non-articular regions of the medial condyles by 2 weeks and develops into osteophytes by 4 weeks post-injury. An unexpected observation is punctate expression of tartrate resistant acid phosphatase activity in unmineralized fibrochondrocytes adjacent to active appositional mineralization. Discussion These observations suggest that fibrocartilage activates prior to degradation of the articular cartilage. Thus clinical and histological imaging of fibrocartilage may be an earlier indicator of disease initiation and may indicate a more appropriate time to start preventative treatment. PMID:25680653

Comparative Study of 3-Dimensional Woven Joint Architectures for Composite Spacecraft Structures

NASA Technical Reports Server (NTRS)

Jones, Justin S.; Polis, Daniel L.; Rowles, Russell R.; Segal, Kenneth N.

2011-01-01

The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate initiated an Advanced Composite Technology (ACT) Project through the Exploration Technology Development Program in order to support the polymer composite needs for future heavy lift launch architectures. As an example, the large composite structural applications on Ares V inspired the evaluation of advanced joining technologies, specifically 3D woven composite joints, which could be applied to segmented barrel structures needed for autoclave cured barrel segments due to autoclave size constraints. Implementation of these 3D woven joint technologies may offer enhancements in damage tolerance without sacrificing weight. However, baseline mechanical performance data is needed to properly analyze the joint stresses and subsequently design/down-select a preform architecture. Six different configurations were designed and prepared for this study; each consisting of a different combination of warp/fill fiber volume ratio and preform interlocking method (Z-fiber, fully interlocked, or hybrid). Tensile testing was performed for this study with the enhancement of a dual camera Digital Image Correlation (DIC) system which provides the capability to measure full-field strains and three dimensional displacements of objects under load. As expected, the ratio of warp/fill fiber has a direct influence on strength and modulus, with higher values measured in the direction of higher fiber volume bias. When comparing the Z-fiber weave to a fully interlocked weave with comparable fiber bias, the Z-fiber weave demonstrated the best performance in two different comparisons. We report the measured tensile strengths and moduli for test coupons from the 6 different weave configurations under study.

Application of High-Impact Polystyrene (HIPS) as a Graphene Nanoparticle Reinforced Composite Thermoplastic Adhesive

NASA Astrophysics Data System (ADS)

Stitt, Erik

Adhesive bonding is a more efficient joining method for composites than traditional mechanical fasteners and provides advantages in weight reduction, simplicity, and cost. In addition, the utilization of mechanical fasteners introduces stress concentrations and damage to the fiber-matrix interface. Adhesive bonding with thermoset polymers distributes mechanical loads but also makes disassembly for repair and recycling difficult. The ability to utilize thermoplastic polymers as adhesives offers an approach to address these limitations and can even produce a reversible adhesive joining technology through combining conductive nanoparticles with a thermoplastic polymer. The incorporation of the conductive nanoparticles allows for selective heating of the adhesive via exposure to electromagnetic (EM) radiation and simultaneously can augment the mechanical properties of the adhesive and the adhesive joint. This approach provides a versatile mechanism for efficiently creating and reversing structural adhesive joints across a wide range of materials. In this work, a high-impact polystyrene (HIPS) co-polymer containing butadiene as a toughness modifier is compounded with graphene nano-platelets (GnP) for investigation as a thermoplastic adhesive. The properties of the bulk composite adhesive are tailored by altering the morphology, dispersion, and concentration of GnP. The thermal response of the material to EM radiation in the microwave frequency spectrum was investigated and optimized. Surface treatments of the adhesive films were explored to enhance the viability of this nanoparticle thermoplastic polymer to function as a reversible adhesive. As a result, it has been shown that lap-shear strengths of multi-material joints produced from aforementioned thermoplastic adhesives were comparable to similar thermoset bonded joints.

Optimization of process parameters for drilled hole quality characteristics during cortical bone drilling using Taguchi method.

PubMed

Singh, Gurmeet; Jain, Vivek; Gupta, Dheeraj; Ghai, Aman

2016-09-01

Orthopaedic surgery involves drilling of bones to get them fixed at their original position. The drilling process used in orthopaedic surgery is most likely to the mechanical drilling process and there is all likelihood that it may harm the already damaged bone, the surrounding bone tissue and nerves, and the peril is not limited at that. It is very much feared that the recovery of that part may be impeded so that it may not be able to sustain life long. To achieve sustainable orthopaedic surgery, a surgeon must try to control the drilling damage at the time of bone drilling. The area around the holes decides the life of bone joint and so, the contiguous area of drilled hole must be intact and retain its properties even after drilling. This study mainly focuses on optimization of drilling parameters like rotational speed, feed rate and the type of tool at three levels each used by Taguchi optimization for surface roughness and material removal rate. The confirmation experiments were also carried out and results found with the confidence interval. Scanning electrode microscopy (SEM) images assisted in getting the micro level information of bone damage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays.

PubMed

Guetterman, Timothy C; Fetters, Michael D; Creswell, John W

2015-11-01

Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. © 2015 Annals of Family Medicine, Inc.

Clinical and radiological features of rheumatoid arthritis in British black Africans.

PubMed

Ravindran, Vinod; Seah, May-Ai; Elias, David A; Choy, Ernest H; Scott, David L; Gordon, Patrick A

2008-01-01

The objective of this study was to determine whether radiographic damage is different in British black African patients with rheumatoid arthritis compared to Caucasian patients. Data on demographics, disease- and disability-related variables were obtained from all black African patients and their age-, gender- and disease-duration-matched Caucasian controls. After all features identifying the patients were concealed, X-rays of hands and feet were scored by using the Sharp/van der Heijde method. Data were analysed using Mann-Whitney U test, t test and chi (2) test. Sixty-four patients (32 in each ethnic group) were studied. The median age was 52 years and median disease duration 6 years. Seventy-two percent of patients were female. Black Africans and Caucasians did not differ significantly in rheumatoid factor positivity, disease-modifying anti-rheumatic drugs and biological treatment use. British black African patients had significantly more tender joints and disability. Joint space narrowing was significantly greater in Caucasian patients [48 (27-85) vs 56 (34-107), p = 0.01]. Caucasian patients had more number of erosions (172 vs 220) and higher erosion score; however, the difference in the erosion scores was not statistically significant [2 (0-48) vs 4.5 (0-46), p = 0.17]. Radiographic damage was less severe in black African patients with rheumatoid arthritis compared to their age-, gender- and disease-duration-matched Caucasian controls. A large prospective study is required to confirm the findings of this study and to establish the factors which might be accountable for any differences in the expression of rheumatoid arthritis in this ethnic group.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stanislavskii, L.Ya.

Large turbogenerators with built-up rotor designs operating in U.S.S.R. power plants were studied to obtain data on reliability, failures, and performance characteristics for normal and abnormal operating conditions. Data for 23 turbogenerators manufactured by domestic and foreign firms were analyzed. The studies showed that the reliability factor of the joints of built-up rotors should be equal to approximately 6 to provide a monolithic built-up rotor. At lower built-up rotor joint reliability factors, weakening of the joints occurred during their operation, leading to extreme generator vibration, damage to the insulating sockets at the joint, burning of the joints and sometimes breakagemore » of the screws holding the joints. When it is necessary to restore the monolithic nature of the joints of a rotor its design should permit replacement of the tightening devices (tie rods, screws). If this is not possible the built-up rotor becomes unsuitable for operation. During abnormal conditions there are maximum temperatures in the joint of a built-up rotor about 50 percent greater than in the end part of the rotor. Thus special structural measures are necessary to improve the electrical contact in the joints of the built-up parts of the rotors of large turbogenerators. In all cases where they are not dictated by construction requirements (supercooled turbogenerators), the use of built-up rotors is unfavorable. (LCL)« less

Direct measurement of hoop strains in the intact and torn human medial meniscus.

PubMed

Jones, R Spencer; Keene, G C R; Learmonth, D J A; Bickerstaff, D; Nawana, N S; Costi, J J; Pearcy, M J

1996-07-01

OBJECTIVE: To measure the circumferential or hoop strains generated in the medial meniscus during loading of the knee joint and to examine the effect of longitudinal and radial tears in the meniscus on these strain values. DESIGN: An in vitro investigation measuring the circumferential strains in the medial menisci of cadaveric human knees as they were loaded in a materials testing machine. BACKGROUND: The menisci transmit approximately 50% of the load through the knee, the rest being transmitted by direct contact of the articular cartilage. Damage to the menisci will alter the pattern of load transmission as will meniscectomy. This study examined the changes in the mechanics of the meniscus in situ as a result of simulated tears to assess the effect of its load carrying capacity and the implications of surgery to remove part or all of a damaged meniscus. METHODS: Nineteen human cadaveric knees were tested. Windows were made in the joint capsule and strain gauges inserted into the anterior, middle and posterior sections of the medial meniscus. The knees were then loaded to three times body weight at speeds of 50 and 500 mm/min, with the knee joint at 0 degrees and 30 degrees of flexion. The tests were repeated following the creation of a longitudinal or a radial tear in the meniscus. RESULTS: The intact menisci showed significantly less strain in the posterior section compared to the anterior and middle sections (P < 0.003, with strains of 1.54%, 2.86% and 2.65% respectively). With a longitudinal tear this pattern changed with strains decreasing anteriorly and increasing posteriorly. There were also significant differences at different angles of knee joint flexion not seen in the intact meniscus. 50% radial tears reduced the strains anteriorly whilst a complete radial tear completely defunctioned the meniscus. CONCLUSIONS: This study has shown that there are significantly different hoop strains produced in different sections of the medial meniscus under load and the patterns of strain distribution are disturbed by meniscal tears. RELEVANCE: These results provide important data for mathematical models which must include non-uniform behaviour. They also have implications for the surgical management of torn menisci. Undamaged portions should be preserved and the integrity of the circumferential fibres maintained to ensure the menisci retain a load bearing capability.

History of the Joint Chiefs of Staff. The Joint Chiefs of Staff and the War in Vietnam, 1960-1968. Part 2

DTIC Science & Technology

2012-01-01

antiaircraft fire.4- Ambassador Taylor recommended to Washington that the three cancelled missions be rescheduled "at once" for the morning of 8 February...officials did authorize a rescheduling of the VNAF strike even though Mr. McNamara doubted that it would do much damage, because it was essential "to...scheduled for 1 March, so that the raids would not coincide with the opening of a major Communist world conclave in Moscow that same day. Rescheduled for

A clamping force measurement system for monitoring the condition of bolted joints on railway track joints and points

NASA Astrophysics Data System (ADS)

Tesfa, B.; Horler, G.; Thobiani, F. Al; Gu, F.; Ball, A. D.

2012-05-01

Many industrial structures associated with railway infrastructures rely on a large number of bolted joint connections to ensure safe and reliable operation of the track and trackside furniture. Significant sums of money are spent annually to repair the damage caused by bolt failures and to maintain the integrity of bolted structures. In the UK, Network Rail (the organization responsible for rail network maintenance and safety) conducts corrective and preventive maintenance manually on 26,000 sets of points (each having approximately 30 bolted joints per set), in order to ensure operational success and safety for the travelling public. Such manual maintenance is costly, disruptive, unreliable and prone to human error. The aim of this work is to provide a means of automatically measuring the clamping force of each individual bolted joint, by means of an instrumented washer. This paper describes the development of a sensor means to be used in the washer, which satisfies the following criteria. Sense changes in the clamping force of the joint and report this fact. Provide compatibility with the large dynamic range of clamping force. Satisfy the limitations in terms of physical size. Provide the means to electronically interface with the washer. Provide a means of powering the washer in situ. Provide a solution at an acceptable cost. Specifically the paper focuses on requirements 1, 2 and 3 and presents the results that support further development of the proposed design and the realization of a pre-prototype system. In the paper, various options for the force sensing element (strain gage, capacitor, piezo-resistive) have been compared, using design optimization techniques. As a result of the evaluation, piezo-resistive sensors in concert with a proprietary force attenuation method, have been found to offer the best performance and cost trade-off The performance of the novel clamping force sensor has been evaluated experimentally and the results show that a smart washer can be developed to monitor the condition of bolted joints as found on railway track and points.

Effect of Boundary Condition on the Shear Behaviour of Rock Joints in the Direct Shear Test

NASA Astrophysics Data System (ADS)

Bahaaddini, M.

2017-05-01

The common method for determination of the mechanical properties of the rock joints is the direct shear test. This paper aims to study the effect of boundary condition on the results of direct shear tests. Experimental studies undertaken in this research showed that the peak shear strength is mostly overestimated. This problem is more pronounced for steep asperities and under high normal stresses. Investigation of the failure mode of these samples showed that tensile cracks are generated at the boundary of sample close to the specimen holders and propagated inside the intact materials. In order to discover the reason of observed failure mechanism in experiments, the direct shear test was simulated using PFC2D. Results of numerical models showed that the gap zone size between the upper and lower specimen holders has a significant effect on the shear mechanism. For the high gap size, stresses concentrate at the vicinity of the tips of specimen holders and result in generation and propagation of tensile cracks inside the intact material. However, by reducing the gap size, stresses are concentrated on asperities, and damage of specimen at its boundary is not observed. Results of this paper show that understanding the shear mechanism of rock joints is an essential step prior to interpreting the results of direct shear tests.

Fatigue injury risk in anterior cruciate ligament of target side knee during golf swing.

PubMed

Purevsuren, Tserenchimed; Kwon, Moon Seok; Park, Won Man; Kim, Kyungsoo; Jang, Seung Ho; Lim, Young-Tae; Kim, Yoon Hyuk

2017-02-28

A golf-related ACL injury can be linked with excessive golf play or practice because such over-use by repetitive golf swing motions can increase damage accumulation to the ACL bundles. In this study, joint angular rotations, forces, and moments, as well as the forces and strains on the ACL of the target-side knee joint, were investigated for ten professional golfers using the multi-body lower extremity model. The fatigue life of the ACL was also predicted by assuming the estimated ACL force as a cyclic load. The ACL force and strain reached their maximum values within a short time just after ball-impact in the follow-through phase. The smaller knee flexion, higher internal tibial rotation, increase of the joint compressive force and knee abduction moment in the follow-through phase were shown as to lead an increased ACL loading. The number of cycles to fatigue failure (fatigue life) in the ACL might be several thousands. It is suggested that the excessive training or practice of swing motion without enough rest may be one of factors to lead to damage or injury in the ACL by the fatigue failure. The present technology can provide fundamental information to understand and prevent the ACL injury for golf players. Copyright © 2017. Published by Elsevier Ltd.

Intermetallic Growth Induced Large-Scale Void Growth and Cracking Failure in Line-Type Cu/Solder/Cu Joints Under Current Stressing

NASA Astrophysics Data System (ADS)

Chen, Zhuo; Tian, Wenya; Li, Junhui; Zhu, Wenhui

2018-04-01

In order to study the electromigration (EM) behavior of solder joints in electronics packaging, especially under high-current and high-temperature working conditions, line-type Cu/solder/Cu butting samples were prepared to observe the microstructural evolution under 1.0 × 104 A/cm2 current stressing. A prominent polarity effect was found such that the Cu6Sn5 intermetallic compound (IMC) layer at the anode side, which thickened linearly with time, was much thicker than that at the cathode side. Compared to the samples subjected to thermal aging at the same temperature of 180°C, EM enhanced the Cu3Sn growth at both the anode and the cathode. Two distinct types of damage were observed after extended duration of current stressing. Back-flow of Cu into Cu3Sn was found at the Cu3Sn/Cu6Sn5 interface of the anode side, causing large voids, while strip cracks developed at the cathode solder/Cu6Sn5 interface, causing a significant increase of joint electrical resistance. With the mass transport characteristics that determine the IMC growth and vacancy accumulation analyzed in detail at each interface, formation mechanisms of the two types of damages are discussed.

75 FR 47796 - Availability of the Draft Joint Environmental Impact Statement/Environmental Impact Report for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-09

... damage to adjacent beachfront structures, including the heavily used rail line that runs along the beach... miles (100 kilometers) south of Los Angeles at the southern end of Orange County near the border of San...

Influence of third-body particles originating from bone void fillers on the wear of ultra-high-molecular-weight polyethylene

PubMed Central

Cowie, Raelene M; Carbone, Silvia; Aiken, Sean; Cooper, John J; Jennings, Louise M

2016-01-01

Calcium sulfate bone void fillers are increasingly being used for dead space management in infected arthroplasty revision surgery. The presence of these materials as loose beads close to the bearing surfaces of joint replacements gives the potential for them to enter the joint becoming trapped between the articulating surfaces; the resulting damage to cobalt chrome counterfaces and the subsequent wear of ultra-high-molecular-weight polyethylene is unknown. In this study, third-body damage to cobalt chrome counterfaces was simulated using particles of the calcium sulfate bone void fillers Stimulan® (Biocomposites Ltd., Keele, UK) and Osteoset® (Wright Medical Technology, TN, USA) using a bespoke rig. Scratches on the cobalt chrome plates were quantified in terms of their density and mean lip height, and the damage caused by the bone void fillers was compared to that caused by particles of SmartSet GMV PMMA bone cement (DePuy Synthes, IN, USA). The surface damage from Stimulan® was below the resolution of the analysis technique used; SmartSet GMV caused 0.19 scratches/mm with a mean lip height of 0.03 µm; Osteoset® led to a significantly higher number (1.62 scratches/mm) of scratches with a higher mean lip height (0.04 µm). Wear tests of ultra-high-molecular-weight polyethylene were carried out in a six-station multi-axial pin on plate reciprocating rig against the damaged plates and compared to negative (highly polished) and positive control plates damaged with a diamond stylus (2 µm lip height). The wear of ultra-high-molecular-weight polyethylene was shown to be similar against the negative control plates and those damaged with third-body particles; there was a significantly higher (p < 0.001) rate of ultra-high-molecular-weight polyethylene wear against the positive control plates. This study showed that bone void fillers of similar composition can cause varying damage to cobalt chrome counterfaces. However, the lip heights of the scratches were not of sufficient magnitude to increase the wear of ultra-high-molecular-weight polyethylene above that of the negative controls. PMID:27312481

Recent progress in the joint velocity-scalar PDF method

NASA Technical Reports Server (NTRS)

Anand, M. S.

1995-01-01

This viewgraph presentation discusses joint velocity-scalar PDF method; turbulent combustion modeling issues for gas turbine combustors; PDF calculations for a recirculating flow; stochastic dissipation model; joint PDF calculations for swirling flows; spray calculations; reduced kinetics/manifold methods; parallel processing; and joint PDF focus areas.

Atlanto-occipital dislocation--part 2: The clinical use of (occipital) condyle-C1 interval, comparison with other diagnostic methods, and the manifestation, management, and outcome of atlanto-occipital dislocation in children.

PubMed

Pang, Dachling; Nemzek, William R; Zovickian, John

2007-11-01

The diagnosis of atlanto-occipital dislocation (AOD) remains problematic as a result of a lack of reliable radiodiagnostic criteria. In Part 1 of the AOD series, we showed that the normal occiput-C1 joint in children has an extremely narrow joint gap (condyle-C1 interval [CCI]) with great left-right symmetry. In Part 2, we used a CCI of 4 mm or greater measured on reformatted computed tomographic (CT) scans as the indicator for AOD and tested the diagnostic sensitivity and specificity of CCI against published criteria. The clinical manifestation, neuroimaging findings, management, and outcome of our series of patients with AOD are also reported. For diagnostic sensitivity, we applied the CCI criterion on 16 patients who fulfilled one or more accepted radiodiagnostic criteria of AOD and who showed clinical and imaging hallmarks of the syndrome. All 16 patients had plain cervical spine x-rays, head CT scans, axial cervical spine CT scans with reconstruction, and magnetic resonance imaging scans. The diagnostic yield and false-negative rate of CCI were compared with those of four published "standard" tests, namely Wholey's dens-basion interval, Powers' ratio, Harris' basion-axis interval, and Sun's interspinous ratio. The diagnostic value of "nonstandard" indicators such as cervicomedullary deficits, tectorial membrane and other ligamentous damage, perimedullary subarachnoid hemorrhage, and extra-axial blood at C1-C2 were also assessed. For diagnostic specificity, we applied CCI and the "standard" and "nonstandard" tests on 10 patients from five classes of non-AOD upper cervical injuries. The false-positive diagnostic rates for AOD of all respective tests were documented. The CCI criterion was positive in all 16 patients with AOD with a diagnostic sensitivity of 100%. Fourteen patients had bilateral AOD with disruption and widening of both OC1 joints. Two patients had unilateral AOD with only one joint wider than 4 mm. The abnormal CCI varied from 5 to 34 mm. Eight patients showed blatant left-right joint asymmetry in either CCI or anatomic conformation. The diagnostic sensitivities for the "standard" tests are as follows: Wholey's, 50%; Powers', 37.5%; Harris', 31%; and Sun's, 25%, with false-negative rates of 50, 62.5, 69, and 75%, respectively. The sensitivities for the "nonstandard" indicators are: tectorial membrane damage, 71%; perimedullary blood, 63%; and C1-C2 extra-axial blood, 75%, with false-negative rates of 29, 37, and 25%, respectively. Fifteen patients with AOD had occiput-cervical fusion. There were one early and two delayed deaths (19% mortality); two patients (12%) had complete or severe residual high quadriplegia, but 11 children (69%) enjoyed excellent neurological recovery. CCI was normal in all 10 patients with non-AOD upper cervical injuries with a diagnostic specificity of 100%. The false-positive rates for the four "standard" tests were: Sun's, 60%; Harris', 50%; Wholey's, 30%; and Powers', 10%; for the "nonstandard" indicator, the rates were: cervicomedullary deficits, 70%; tectorial membrane damage, 40%; C1-C2 extra-axial blood, 40%; and perimedullary blood, 30%. The CCI criterion has the highest diagnostic sensitivity and specificity for AOD among all other radiodiagnostic criteria and indicators. CCI is easily computed from reconstructed CT scans, has almost no logistical or technical distortions, can capture occiput-C1 joint dislocation in all three planes, and is unaffected by congenital anomalies or maturation changes of adjacent structures. Because CCI is the only test that directly measures the integrity of the actual joint injured in AOD and a widened CCI cannot be concealed by postinjury changes in the head and neck relationship, it surpasses others that use changeable landmarks.

Sandia/Stanford Unified Creep Plasticity Damage Model for ANSYS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, David M.; Vianco, Paul T.; Fossum, Arlo F.

2006-09-03

A unified creep plasticity (UCP) model was developed, based upon the time-dependent and time-independent deformation properties of the 95.5Sn-3.9Ag-0.6Cu (wt.%) soldier that were measured at Sandia. Then, a damage parameter, D, was added to the equation to develop the unified creep plasticity damage (UCPD) model. The parameter, D, was parameterized, using data obtained at Sandia from isothermal fatigue experiments on a double-lap shear test. The softwae was validated against a BGA solder joint exposed to thermal cycling. The UCPD model was put into the ANSYS finite element as a subroutine. So, the softwae is the subroutine for ANSYS 8.1.

Damage of chromosoms under irradiation of human blood lymphocytes and development of bystander effect.

PubMed

Shemetun, O V

2016-12-01

the research the distribution of radiation induced damages among chromosomes and their bands in irra diated in vitro human blood lymphocytes and in unirradiated bystander cells.Material and methods of research: cultivation of human peripheral blood lymphocytes by semi micromethod D.A. Hungerford, modeling of radiation induced bystander effect in mixed cultures consisting of irradiated in vitro and non irradiated blood lymphocytes from persons of different gender, GTG staining of metaphase chromosomes and their cytogenetic analysis. Break points in chromosomes under the formation of aberrations were identified in exposed in vitro human peripheral blood lymphocytes in doses 0.25 Gy (95 breaks in 1248 cells) and 1.0 Gy (227 breaks in 726 cells) and in non irradiated bystander cells under their joint cultivation with irradiated in vitro human lymphocytes (51 breaks in 1137 cells at irradiation of adjacent populations of lymphocytes in dose 0.25 Gy and 75 breaks in 1321 cells at irradiation of adjacent population of lymphocytes in a dose 1.0 Gy). The distribution of injuries among the chromo somes and their bands was investigated. in radiation exposed in vitro human peripheral blood lymphocytes as well as in bystander cells the fre quency of damaged bands and number of breaks which localized in them exceeded the control value (p < 0.01). As under direct radiation exposure, as under formation of breaks due to induction of bystander effect, chromosomes were damaged according to their relative length. Location of bands with increasing number of breaks coincided with the «hot spots» of chromosome damage following irradiation and fragile sites. More sensitive to damage were G negative euchromatin chromosome bands, in which were localized 82 88 % breaks. Damageability of telomeric regions in the irradiated cells had no significant difference from the control, while in bystander cells was lower than control value (p < 0.05). O. V. Shemetun.

A Single-Lap Joint Adhesive Bonding Optimization Method Using Gradient and Genetic Algorithms

NASA Technical Reports Server (NTRS)

Smeltzer, Stanley S., III; Finckenor, Jeffrey L.

1999-01-01

A natural process for any engineer, scientist, educator, etc. is to seek the most efficient method for accomplishing a given task. In the case of structural design, an area that has a significant impact on the structural efficiency is joint design. Unless the structure is machined from a solid block of material, the individual components which compose the overall structure must be joined together. The method for joining a structure varies depending on the applied loads, material, assembly and disassembly requirements, service life, environment, etc. Using both metallic and fiber reinforced plastic materials limits the user to two methods or a combination of these methods for joining the components into one structure. The first is mechanical fastening and the second is adhesive bonding. Mechanical fastening is by far the most popular joining technique; however, in terms of structural efficiency, adhesive bonding provides a superior joint since the load is distributed uniformly across the joint. The purpose of this paper is to develop a method for optimizing single-lap joint adhesive bonded structures using both gradient and genetic algorithms and comparing the solution process for each method. The goal of the single-lap joint optimization is to find the most efficient structure that meets the imposed requirements while still remaining as lightweight, economical, and reliable as possible. For the single-lap joint, an optimum joint is determined by minimizing the weight of the overall joint based on constraints from adhesive strengths as well as empirically derived rules. The analytical solution of the sin-le-lap joint is determined using the classical Goland-Reissner technique for case 2 type adhesive joints. Joint weight minimization is achieved using a commercially available routine, Design Optimization Tool (DOT), for the gradient solution while an author developed method is used for the genetic algorithm solution. Results illustrate the critical design variables as a function of adhesive properties and convergences of different joints based on the two optimization methods.

Race, ethnicity, and disease outcomes in juvenile idiopathic arthritis: a cross-sectional analysis of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry.

PubMed

Ringold, Sarah; Beukelman, Timothy; Nigrovic, Peter A; Kimura, Yukiko

2013-06-01

To measure the associations between self-reported race and ethnicity and disease outcomes, including joint damage, pain, and functional ability, in children with juvenile idiopathic arthritis (JIA). A cross-sectional analysis of children with JIA enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry between May 2010 and March 2012. Mann-Whitney U test and chi-square testing were used to compare patient characteristics between race (white, African American, or Asian) and ethnicity (Non-Hispanic and Non-Latino; Hispanic or Latino) categories. Logistic regression was used to measure the associations between each race or ethnicity category and the outcome of interest. Race category was available for 4292 of 4682 children (93% white, 5% African American, Asian 3%). Ethnicity data were available for 4644 (11% Hispanic or Latino). African American children with polyarticular-course JIA had an elevated OR for joint damage on radiographic imaging compared to white children (OR 1.9, 95% CI 1.0-3.1; p = 0.04). Hispanic/Latino children had increased odds of having disability scores > 75th percentile (OR 1.5, 95% CI 1.1-2.1; p < 0.01) compared to non-Hispanic/Latino children; however, these odds were no longer significant when the cohort was limited to children with polyarticular-course JIA. Asian children had decreased odds of higher pain and functional disability compared to white children (p < 0.05). Race and ethnicity were variably associated with joint damage, pain, and functional ability. Understanding outcome variation between different race and ethnicity groups may help to optimize care for children with JIA.

Concepts and challenges in the use of mesenchymal stem cells as a treatment for cartilage damage in the horse.

PubMed

Zayed, Mohammed; Adair, Steve; Ursini, Tena; Schumacher, James; Misk, Nabil; Dhar, Madhu

2018-03-20

Osteoarthritis (OA), the most common form of joint disease affecting humans and horses, is characterized by the advance and decline of cartilage and loss of function of the affected joint. The progression of OA is steadily accompanied with biochemical events, which interfere with the cytokines and proteolytic enzymes responsible for progress of the disease. Recently, regenerative therapies have been used with an assumption that mesenchymal stem cells (MSCs) possess the potential to prevent the advancement of cartilage damage and potentially regenerate the injured tissue with an ultimate goal of preventing OA. We believe that despite various challenges, the use of allogenic versus autologous MSCs in cartilage regeneration, is a major issue which can directly or indirectly affect the other factors including, the timing of implantation, dose or cell numbers for implantation, and the source of MSCs. Current knowledge reporting some of these challenges that the clinicians might face in the treatment of cartilage damage in horses are presented. In this regard we conducted two independent studies. In the first study we compared donor matched bone marrow and synovial fluid - derived equine MSCs in vitro, and showed that the SFMSCs were similar to the BMMSCs in their proliferation, expression of CD29, CD44 and CD90, but, exhibited a significantly different chondrogenesis. Additionally, 3.2-21% of all SFMSCs were positive for MHC II, whereas, BMMSCs were negative. In the second study we observed that injection of both the autologous and allogenic SFMSCs into the tarsocrural joint resulted in elevated levels of total protein and total nucleated cell counts. Further experiments to evaluate the in vivo acute or chronic response to allogenic or autologous MSCs are imperative. Copyright © 2018 Elsevier Ltd. All rights reserved.

A biomechanical evaluation to optimize the configuration of a hinged external fixator for the primary treatment of severely displaced intraarticular calcaneus fractures with soft tissue damage.

PubMed

Besch, Lutz; Schmidt, Ina; Mueller, Michael; Daniels-Wredenhagen, Mark; Hilgert, Ralf-Eric; Varoga, Deike; Seekamp, Andreas

2008-01-01

The purpose of this investigation was to develop an optimized hinged external fixator for the primary treatment of dislocated, intra-articular calcaneus fractures with associated soft tissue damage. To this end, a calcaneus model was made out of a polyurethane block, and a steel cylinder served as the ankle joint and was connected to a synthetic model of the tibia via a metal clamp. A saw cut served as the fracture in the model. A Steinmann nail and Schanz screw were placed in defined positions in the model and connected medially and laterally with longitudinal support rods. The fixator allowed a total of 20 degrees of plantar- and dorsiflexion, with rotation in the virtual axis of the upper ankle joint. Changes in the model fracture were measured during cyclical strain, and at different screw positions in the model tibia and calcaneus. Miniature force sensors located on the longitudinal support rods, and a plantar tension spring, were used to measure pressure and tension. Reproducible values were determined and, with the optimal configuration, shifting within the osteotomy was minimal. In the experimental configuration, optimal tibial screw placement was 70 mm proximal to the rotation axis of the upper ankle joint, and optimal placement of the Steinmann nail was in the posterior surface of the calcaneus. These findings indicated that the hinged fixator allows 20 degrees of ankle movement without alteration of the rotation axis, and suggest that this type of external fixator can be used in all types of calcaneal fracture regardless of the soft tissue damage. ACFAS Level of Clinical Evidence: 5c.

[Potential influence of nutrition with supplements on healthy and arthritic joints. II. Nutritional quantity, supplements, contamination].

PubMed

Wilhelmi, G

1993-01-01

A short period of fasting leads, in the mouse, to usually reversible damage to chondrocytes and in patients with rheumatoid arthritis often to a temporary improvement. Slight hypo-alimentation and a low-caloric diet reduce the spontaneous development of osteo-arthritis in the mouse, whereas a high-caloric diet promotes the disease. In man, mice, and, in particular, fattened animals, obesity is often associated with forms of osteo-arthritis. In such cases, it may be assumed that metabolic damage to cartilage is involved as well as damage due to weight-bearing forces. Elderly people, i.e., persons with a predisposition to osteo-arthritis, often suffer from a generalized vitamin deficiency. Vitamins E, B2, and C have been shown to exert an inhibitory effect on osteo-arthritis in animals, and it has been found that supplementation therapy, particularly with vitamin E and the combination of vitamins B1, B6, and B12, can exert a beneficial effect on the symptomatology of human degenerative joint disease. Mineral deficits in calcium, zinc and selenium (Kashin-Beck disease; endemic osteo-arthritis deformans) can provoke skeletal damage in humans and animals. On the other hand, calcium, iron, and copper have been reported to give rise to storage diseases, in some cases with involvement of articular cartilage. There have been indications that chondrotoxic damage may result from food contaminants. So far very little is known about the influence of phytopharmacodynamic substances (other than derivatives of rutin and rhein) on osteo-arthritis. The large gaps in our knowledge of the chondrotropic properties of the constituents of food and common stimulants underline the need for further investigations.

Contingent Valuation Assessment of the Economic Damages of Pollution to Marine Recreational Fishing (1989)

EPA Pesticide Factsheets

Paper develops a fully utility-theoretic model for the demand for recreational fishing access days, applied to a sample of Texas Gulf Coast anglers. The model employs contingent valuation and travel cost data jointly to calibrate a utility function.

Inspection criteria ensure quality control of parallel gap soldering

NASA Technical Reports Server (NTRS)

Burka, J. A.

1968-01-01

Investigation of parallel gap soldering of electrical leads resulted in recommendation on material preparation, equipment, process control, and visual inspection criteria to ensure reliable solder joints. The recommendations will minimize problems in heat-dwell time, amount of solder, bridging conductors, and damage of circuitry.

Technical feasibility of personalized articulating knee joint distraction for treatment of tibiofemoral osteoarthritis.

PubMed

Struik, T; Jaspers, J E N; Besselink, N J; van Roermund, P M; Plomp, S; Rudert, M J; Lafeber, F P J G; Mastbergen, S C

2017-11-01

Knee osteoarthritis is a highly prevalent degenerative joint disorder characterized by joint tissue damage and pain. Knee joint distraction has been introduced as a joint preserving surgical procedure to postpone knee arthroplasty. An often used standard externally fixation device for distraction poses a burden to patients due to the absence of joint flexion during the 6weeks treatment. Therefore, a personalized articulating distraction device was developed. The aim of this study was to test technical feasibility of this device. Based on an often applied rigid device, using equal bone pin positions and connectors, a hinge mechanism was developed consisting of a cam-following system for reproducing the complex joint-specific knee kinematics. In support, a device was developed for capturing the joint-specific sagittal plane articulation. The obtained kinematic data were translated into joint-specific cam shapes that were installed bilaterally in the hinge mechanism of the distraction device, as such providing personalized knee motion. Distraction of 5mm was performed within a range of motion of 30deg. joint flexion. Pre-clinical evaluation of the working principle was performed on human cadaveric legs and system stiffness characteristics were biomechanically evaluated. The desired range of motion was obtained and distraction was maintained under physiologically representative loading. Moreover, the joint-specific approach demonstrated tolerance of deviations from anatomical and alignment origin during initial placement of the developed distraction device. Articulation during knee distraction is considered technically feasible and has potential to decrease burden and improve acceptance of distraction therapy. Testing of clinical feasibility is warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

Imaging tools to measure treatment response in gout.

PubMed

Dalbeth, Nicola; Doyle, Anthony J

2018-01-01

Imaging tests are in clinical use for diagnosis, assessment of disease severity and as a marker of treatment response in people with gout. Various imaging tests have differing properties for assessing the three key disease domains in gout: urate deposition (including tophus burden), joint inflammation and structural joint damage. Dual-energy CT allows measurement of urate deposition and bone damage, and ultrasonography allows assessment of all three domains. Scoring systems have been described that allow radiological quantification of disease severity and these scoring systems may play a role in assessing the response to treatment in gout. This article reviews the properties of imaging tests, describes the available scoring systems for quantification of disease severity and discusses the challenges and controversies regarding the use of imaging tools to measure treatment response in gout. © The Author 2018. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of the bond-slip relationship on the flexural capacity of R.C. joints damaged by corrosion

NASA Astrophysics Data System (ADS)

Imperatore, Stefania

2016-06-01

In moderate and aggressive environmental condition, old reinforced concrete structures are often subjected to corrosive phenomena. Corrosion causes cracking, loss of diameter in reinforcement and variation of the bond behavior between steel and concrete. Then, in presence of cyclic actions like the seismic ones, old R.C. elements vary their ultimate drift, ductility, plastic rotation capacity and energy dissipation with the corrosion level. The problem is of current interest: the issue has been introduced in some paragraph of the Model Code 2010 and a committee is now drafting a new document on assessment strategies on existing concrete structures also damaged by corrosion. In this work, a first step on the analysis of the impact of the corrosion on the seismic behavior of R.C. elements is assessed: by mean FEM analyses, of a poor detailed column/foundation joint is analyzed in a parametric way in order to evaluate the influence of the bond-slip degradation by corrosion on the element flexural capacity.

Photodynamic damage to cartilage and synovial tissue grafted on a chick's chorioallantoic membrane

NASA Astrophysics Data System (ADS)

Fisher, M.; Nahir, A. M.; Kimel, Sol

1997-09-01

Rheumatoid arthritis (RA) is a chronic inflammatory disease of the synovial joints causing pain deformities and disability. The highly vascular inflamed synovium has aggressive and destructive characteristics, it invades, erodes and gradually destroys cartilage and underlying bone. Photodynamic therapy (PDT) was performed using the chick chorioallantoic membrane (CAM) model to investigate the vitality of synovium and cartilage implanted on the CAM. Synovium, obtained from human patients, was grafted onto the CAM; gross microscopy and histology proved its vitality 7 days post grafting. Cartilage obtained from rabbit knee joint was also maintained on the CAM for 7 days. Its vitality was demonstrated by histology and by measuring metabolic and enzymatic activity of cartilage cells (chondrocytes) as well as the collagen and proteoglycans content. Selective PDT was performed using aluminum phthalocyanine tetrasulfonate (AlPcS4), a hydrophilic compound, soluble in biological solutions, as a photosensitizer. After irradiation with a diode laser (lambda equals 670 nm, 10 mW) damage was observed in vascularized synovium grafts, whereas avascular cartilage remained intact.

Engineering tendon and ligament tissues: present developments towards successful clinical products.

PubMed

Rodrigues, Márcia T; Reis, Rui L; Gomes, Manuela E

2013-09-01

Musculoskeletal diseases are one of the leading causes of disability worldwide. Among them, tendon and ligament injuries represent an important aspect to consider in both athletes and active working people. Tendon and ligament damage is an important cause of joint instability, and progresses into early onset of osteoarthritis, pain, disability and eventually the need for joint replacement surgery. The social and economical burden associated with these medical conditions presents a compelling argument for greater understanding and expanding research on this issue. The particular physiology of tendons and ligaments (avascular, hypocellular and overall structural mechanical features) makes it difficult for currently available treatments to reach a complete and long-term functional repair of the damaged tissue, especially when complete tear occurs. Despite the effort, the treatment modalities for tendon and ligament are suboptimal, which have led to the development of alternative therapies, such as the delivery of growth factors, development of engineered scaffolds or the application of stem cells, which have been approached in this review. Copyright © 2012 John Wiley & Sons, Ltd.

Pulsed CO2 laser for intra-articular cartilage vaporization and subchondral bone perforation in horses

NASA Astrophysics Data System (ADS)

Nixon, Alan J.; Roth, Jerry E.; Krook, Lennart P.

1991-05-01

A pulsed carbon dioxide laser was used to vaporize articular cartilage in four horses, and perforate the cartilage and subchondral bone in four horses. Both intercarpal joints were examined arthroscopically and either a 1 cm cartilage crater or a series of holes was created in the third carpal bone of one joint. The contralateral carpus served as a control. The horses were evaluated clinically for 8 weeks, euthanatized and the joints examined radiographically, grossly, and histologically. Pulsed carbon dioxide laser vaporized cartilage readily but penetrated bone poorly. Cartilage vaporization resulted in no greater swelling, heat, pain on flexion, lameness, or synovial fluid reaction than the sham procedure. Laser drilling resulted in a shallow, charred hole with a tenacious carbon residue, and in combination with the thermal damage to deeper bone, resulted in increased swelling, mild lameness and a low-grade, but persistent synovitis. Cartilage removal by laser vaporization resulted in rapid regrowth with fibrous and fibrovascular tissue and occasional regions of fibrocartilage at week 8. The subchondral bone, synovial membrane, and draining lymph nodes appeared essentially unaffected by the laser cartilage vaporization procedure. Conversely, carbon dioxide laser drilling of subchondral bone resulted in poor penetration, extensive areas of thermal necrosis of bone, and significant secondary damage to the apposing articular surface of the radial carpal bone. The carbon dioxide laser is a useful intraarticular instrument for removal of cartilage and has potential application in inaccessible regions of diarthrodial joints. It does not penetrate bone sufficiently to have application in subchondral drilling.

Fractional calculus model of articular cartilage based on experimental stress-relaxation

NASA Astrophysics Data System (ADS)

Smyth, P. A.; Green, I.

2015-05-01

Articular cartilage is a unique substance that protects joints from damage and wear. Many decades of research have led to detailed biphasic and triphasic models for the intricate structure and behavior of cartilage. However, the models contain many assumptions on boundary conditions, permeability, viscosity, model size, loading, etc., that complicate the description of cartilage. For impact studies or biomimetic applications, cartilage can be studied phenomenologically to reduce modeling complexity. This work reports experimental results on the stress-relaxation of equine articular cartilage in unconfined loading. The response is described by a fractional calculus viscoelastic model, which gives storage and loss moduli as functions of frequency, rendering multiple advantages: (1) the fractional calculus model is robust, meaning that fewer constants are needed to accurately capture a wide spectrum of viscoelastic behavior compared to other viscoelastic models (e.g., Prony series), (2) in the special case where the fractional derivative is 1/2, it is shown that there is a straightforward time-domain representation, (3) the eigenvalue problem is simplified in subsequent dynamic studies, and (4) cartilage stress-relaxation can be described with as few as three constants, giving an advantage for large-scale dynamic studies that account for joint motion or impact. Moreover, the resulting storage and loss moduli can quantify healthy, damaged, or cultured cartilage, as well as artificial joints. The proposed characterization is suited for high-level analysis of multiphase materials, where the separate contribution of each phase is not desired. Potential uses of this analysis include biomimetic dampers and bearings, or artificial joints where the effective stiffness and damping are fundamental parameters.

Detecting severity of delamination in a lap joint using S-parameters

NASA Astrophysics Data System (ADS)

Islam, M. M.; Huang, H.

2018-03-01

The scattering parameters (S-parameters) represent the frequency response of a two-port linear time-invariant network. Treating a lap joint structure instrumented with two piezoelectric wafer active transducers (PWaTs) as such a network, this paper investigates the application of the S-parameters for detecting the severity of delamination in the lap joint. The pulse-echo signal calculated from the reflection coefficients, namely the S 11 and S 22-parameters, can be divided into three signals, i.e. the excitation, resonant, and echo signals, based on their respective time spans. Analyzing the effects of the delamination on the resonant signal enables us to identify the resonance at which the resonant characteristics of the PWaTs are least sensitive to the delamination. Only at this resonance, we found that the reflection coefficients and the amplitude of the first arrival echo signal changed monotonously with the increase of the delamination length. This discovery is further validated by the time-domain pitch-catch signal calculated from the transmission coefficient (i.e. the S 21-parameter). In addition, comparing the pulse-echo signals obtained from both PWaTs enables us to determine the side of the lap joint that the delamination is located at. This work establishes the S-parameters as an effective tool to evaluate the effects of damage on the PWaT resonant characteristics, based on which the PWaT resonance can be selected judiciously for damage severity detection. Correlating the reflection and transmission coefficients also provide addition validations that increase the detection confidence.

Characterization of arthralgia induced by PD-1 antibody treatment in patients with metastasized cutaneous malignancies.

PubMed

Buder-Bakhaya, Kristina; Benesova, Karolina; Schulz, Carsten; Anwar, Hoda; Dimitrakopoulou-Strauss, Antonia; Weber, Tim F; Enk, Alexander; Lorenz, Hanns-Martin; Hassel, Jessica C

2018-02-01

PD-1 antibodies (PD1ab) are increasingly used in metastatic melanoma and other malignancies. Arthralgia is an underestimated side effect of PD-1 antibody treatment with unknown cause. Our aim was to characterize PD1ab-induced arthralgia. We retrospectively included patients with metastatic cutaneous malignancies treated with pembrolizumab or nivolumab ± ipilimumab at the National Center for Tumor Diseases (Heidelberg) between 01/2013 and 09/2016. Arthralgia was characterized by laboratory diagnostics, imaging, and if indicated, rheumatologic consultation. 26 of 195 patients (13.3%) developed arthralgia. The median onset of symptoms was 100 days (7-780 days). Most frequently, arthralgia involved large joints (shoulders, knees) in a predominantly symmetrical pattern. Only two patients were seropositive for rheumatoid factor and/or anti-citrullinated protein antibodies. Ten patients developed the clinical picture of arthritis, with seven of them showing synovitis in MRI or PET/CT. Five patients showed inflammation in joints pre-damaged by osteoarthritis. In 11 patients arthralgia could not be specified. The majority of patients was satisfactorily treated with non-steroidal anti-inflammatory drugs (NSAIDs), 23.1% required additional low-dose corticosteroids and only 7.6% of our patients received further immunosuppressive treatment. Patients with arthralgia showed a better treatment response and improved PFS and OS. Arthralgia is frequent during PD1ab treatment. The clinical picture varies between synovitis of predominantly large joints, progressive osteoarthritis and arthralgia without evident joint damage. Vast majority of cases can be satisfactorily managed by NSAID and/or low-dose corticosteroids.