A randomized, double blind, placebo controlled multicenter trial of murine anti-CD4 monoclonal antibody therapy in rheumatoid arthritis

To assess the feasibility and advantages of functional motion-mode (M-mode) sonography in pediatric patients with various non-cardiac M-mode applications, 50 patients aged 6 days to 14.5 years with megaureter, diaphragmatic palsy and spinal cord malformation were studied. In addition to initial conventional brightness-mode gray-scale ultrasound. M-mode sonography was performed for evaluation of motion and possible impairment. The findings were compared with other imaging results. The impact of the sonographic results on clinical management was evaluated retrospectively. Impaired motion was demonstrated by conventional sonography in all cases. Only M-mode sonography enabled adequate documentation for comparison with follow-up examinations, but allowed only semiquantitative assessment. Thus even gradual improvement or deterioration can be followed in an unbiased way by using a better-documented investigation for comparison, though an objective 'ranking', especially of diaphragmatic movement, could not be achieved. M-mode sonography enables a non-invasive and non-ionizing evaluation and documentation of motion impairment in pediatric patients. It improves documentation of motion and enables a better comparison with previous findings. It is especially useful for follow-up in evolving disease.     

Durability of FRP Composite Bridge Deck Materials under Freeze-Thaw and Low Temperature Conditions

Fiber-reinforced polymer (FRP) composites, especially lightweight sandwich structures, are rapidly finding their way into civil infrastructure application. FRP composite panels are particularly attractive as bridge deck systems due to their high strength, low density, and durability, which are of importance to the bridge industry. Most of the vast amount of durability data for FRP has been generated for aerospace and automotive applications, which involve very different service conditions than civil infrastructure. For civil engineering applications, it is essential to examine the durability performance of FRP materials under weathering conditions. The ultimate goal of this research is to develop a reliable framework for durability assessment of FRP decks, including laboratory testing procedure and finite-element simulation capability. Such a framework should be applicable to all types of FRP deck construction. In this paper, specimens of typical FRP bridge deck skin materials are subjected to freeze-thaw cycling between 4.4 and ?17.8°C in media of dry air, distilled water, and saltwater, and constant freeze at ?17.8°C . The selected deck is used as an example for demonstration purposes. In addition, selected specimens are subjected to simultaneous environmental exposure conditions and sustained loading of 25% ultimate strain. It should be emphasized that most of the environmental conditions reported in the literature produce minor deterioration of a single composite property, and the assessment of such effect on this single property becomes unreliable because of a large property variation. Therefore, in this paper we use multiple mechanical properties as performance indices for damage evaluation. Based on findings from this work, it is concluded that freeze-thaw cycling between 4.4 and ?17.8°C alone and up to 1,250 h and 625 cycles caused very insignificant or no change in the flexural strength, storage modulus, and loss factor of the FRP specimens conditioned in dry air, distilled water, and saltwater. Small reductions in storage modulus (about 1% or less) were observed when specimens were prestrained and subjected to 250 freeze-thaw cycles in distilled water and saltwater. Changes in flexural strength were statistically insignificant, since they were within the data scatter.     

Durable Repairs on Marine Bridge Piles

Durable repairs of bridge piles exposed to a marine environment require a proper repair design, which includes understanding and preventing the deterioration mechanism in such environments and proper construction methods. To understand how repair systems work, it is important to recognize which deterioration mechanism the system prevents and controls. Conversely, to understand why a system does not work, one must determine the deterioration mechanisms that the system failed to control. The deterioration mechanism should be addressed before repair construction starts so that an appropriate solution can be achieved. Also, construction practices that accelerate deterioration mechanisms should be recognized and avoided. This paper describes efficient construction methods that can be incorporated in the construction of bridge pile repairs. It also gives recommendations to increase the life of a bridge pile repair by analyzing deterioration of repaired structures, defining the cause of deterioration, providing suggestions to enhance the performance of the repair by practical and feasible actions, and giving an integrated approach to bridge repair construction processes.     

Penetrating neck trauma

Penetrating neck trauma can pose significant diagnostic and therapeutic challenges for emergency physicians. Factors contributing to these problems are complex anatomy, proximity of vital structures, and potential for rapid deterioration of airway, vascular, or neurologic injuries. Other contributing factors are the lack of consensus in the literature regarding appropriate evaluation and management of penetrating neck injuries, and insufficient resources or experienced personnel at some institutions. This review focuses on the key components of the history and physical examinations that allow for an assessment of the severity and type of structures involved. In addition, current methods of airway management, as well as ways to manage penetrating neck trauma efficiently and cost effectively, are discussed.     

In Situ Performance Testing of Deteriorating Water Tanks for Durability Assessment

Reports of failure of existing concrete structures due to a lack of durability, rather than a deficiency in structural strength, has made concrete technologists, engineers, and researchers focus research on the parameters influencing durability performance with respect to time. Systematic performance monitoring, with respect to chosen durability parameters of existing concrete structures, will decide the direction of future research in this area. Inferences based on laboratory simulations and testing need to be confirmed by in situ field measurements and studies. In situ condition rating and performance monitoring surveys have been conducted by many researchers, scientists, and professional associations, and reported in literature. Inferences of few such studies are summarized and discussed. Deterioration of concrete structures constructed in recent times is observed at relatively faster rates, and has been mainly attributed to cracking. Cracking is associated with the use of faster-hydrating portland cements with increased fineness and the tricalcium silicate (C3S) content to support the high speed of modern construction. In the present research, a case study of deteriorated water tank structures situated in the semitropical region of India is presented. Some selected parameters—such as concrete cover, carbonation depth, chloride concentration, compressive strength, etc. which influence long term durability of structures—have been measured.     

Bayesian Network Enhanced with Structural Reliability Methods: Application

The enhanced Bayesian network (eBN) methodology described in the companion paper facilitates the assessment of reliability and risk of engineering systems when information about the system evolves in time. We present the application of the eBN: (1) to the assessment of the life-cycle reliability of a structural system; (2) to the optimization of a decision on performing measurements in that structural system; and (3) to the risk assessment of an infrastructure system subject to natural hazards and deterioration of constituent structures. In all applications, observations of system performances or the hazards are made at various points in time and the eBN efficiently includes these observations in the analysis to provide an updated probabilistic model of the system at all times.     

Medical technology assessment: economic evaluation of new technologies

Growing expenditures in health care made it necessary to find control mechanisms to evaluate expenditure. Medical technology assessment is becoming a valuable tool to assist policymakers in controlling new medical technologies. This review deals with the increasing importance of economic evaluation as part of medical technology assessment and describes various techniques by which an economic evaluation can be performed.     

Policies to influence the spatial distribution of physicians: a conceptual review of selected programs and empirical evidence

To increase the usefulness of existing physician location literature for policy evaluation, literature is grouped into intraurban and urban-rural studies. A conceptual overview of physician location literature is presented. Consensus results, if any, are discussed. A list of hypotheses suggested by the literature is then utilized in a discussion of economic social, prior exposure, and professional development incentives embodied in selected public and private sector programs. Programs are evaluated by type of incentive mechanism and geographic target area to determine if present program structures are based on a solid empirical foundation. This assessment indicates that, in general, use of prevalent location incentive mechanisms is not justified by a consensus of empirical evidence.     

Improving telephone follow-up after ambulatory surgery

BACKGROUND: An increasing proportion of patients attended at hospital emergence departments (HED) are elderly people. OBJECTIVES: a) To check the reliability of the usual medical assessment to detect the cognitive deterioration in elderly people attended at HED, compared with that performed systematically by means of an evaluation test of cognitive functions; b) to study the applicability of such a test in HED, on the basis of the time necessary for its administration, and c) to describe the deterioration prevalence in that group of patients and identify the possible associated risks for its detection in patients. PATIENTS AND METHODS: Prospective study including patients aged > or = 60 years attended at a HED, using the orientation, memory and concentration test (OMC) to perform the cognitive assessment. RESULTS: A total of 352 patients who had no exclusion criteria out of the 536 attended during the study period were included. Cognitive deterioration was not detected in 111 patients (31.5%); it was mild in 147 (41.8%), moderate in 71 (20.2%) and severe in 23 (6.5%). In patients with moderate-severe deterioration according to the OMC test, such a deterioration was detected by the usual medical evaluation in 7% of cases. The mean time in completing the test was 2.6 +/- 0.9 minutes. An age > or = 80 years was associated with an increased relative risk for detecting moderate-severe cognitive deterioration (1.98; 95% CI, 1.42-2.78; p < 0.001), whereas the discharge diagnosis of respiratory disease was associated with a decrease of the relative risk (0.41; 95% CI, 0.19-0.89; p < 0.05). No association was observed with other factors, such as gender, home residence or final destination from the emergency department. CONCLUSIONS: The prevalence of cognitive deterioration in elderly people attended at HED is high and increases with age. The OMC test can be administered at HED to detect cognitive deterioration, which is not frequently detected by the usual medical assessment.     

Framework for Evaluating the Performance of Engineering Consultants

The evaluation of consultant’s performance is crucial to the success of a consulting assignment especially when today’s construction projects are becoming more sophisticated, large-scale, and risky. However, since individual clients have developed their own consultant’s performance evaluation (CPE) procedures, the sharing of performance information, though desirable, may not be too meaningful as the results of evaluation could be inconsistent. There is a need to examine whether a unified framework can be derived for CPE. The aim of this paper is to improve the transparency and rigorousness of CPE through the establishment of an evaluating framework for gauging the performance of engineering consultants. In this paper, a comprehensive set of evaluation criteria is identified, and the significance of these criteria is discussed through an empirical survey. Then, a multicriteria model for evaluating the performance of engineering consultants is presented. The results indicate that once an acceptable CPE framework is devised, the performance scores can be utilized for various purposes, including monitor and control, incentive and sanction, preselection, technical assessment, and bid evaluation.     

Realistic Assessment for Safety and Service Life of Reinforced Concrete Decks in Girder Bridges

The lack of safety of deck slabs in bridges generally causes frequent repair and strengthening. The repair induces great loss of economy, not only due to direct cost by repair, but also due to stopping the public use of such structures during repair. The major reason for this frequent repair is mainly due to the lack of a realistic and accurate assessment system for bridge decks. The purpose of the present paper is therefore to develop a realistic assessment system which can estimate reasonably the safety, as well as the service life of concrete bridge decks, based on the deterioration models that are derived from both the traffic loads and environmental effect. A deterioration model due to chloride ingress is first established. The damage models due to repetitive traffic loads considering the dry and wet conditions of deck slabs are proposed. These models are used to calculate the remaining life of a bridge deck slab. A prediction method for service life of deck slab due to loading and environmental effects is developed based on material, as well as structural evaluation. The proposed method includes the assessment of corrosion in material level, and the analyses of flexure, shear, and fatigue in structural level. Finally, an assessment system for prediction of safety and remaining service life is developed based on the theories established in this study. The developed assessment system will allow the correct diagnosis of damage state and the realistic prediction of service life of concrete decks in girder bridges.     

Environmental Fatigue and Static Behavior of RC Beams Strengthened with Carbon-Fiber-Reinforced Polymer

Many countries around the world have tremendous needs to repair and strengthen their transportation infrastructure. Almost everywhere, traffic loads have reached levels largely exceeding design expectations. Northern countries also experience severe winter conditions that are combined with an extensive use of deicing salts and accelerate structural deterioration. In Canada, the extent of deterioration has prompted many authorities, including the federal and provincial governments, to investigate the potential use of fiber-reinforced polymer products to extend the life of their existing structures. However, it is widely recognized that the large-scale implementation of these products is often impaired by the lack of data on their durability. This paper presents an experimental project undertaken in order to assess the durability of reinforced concrete beams externally strengthened with two types of carbon-fiber-reinforced polymer (CFRP). The beams were first exposed to either wet-dry cycles or continuous immersion in water and then were loaded in fatigue. Finally, they were tested quasi-statically under four-point bending up to failure. The test results presented here provide some insights on the potential long-term performance of CFRP-strengthened beams exposed to severe environmental conditions.     

Thermo-Chemo-Mechanics of ASR Expansion in Concrete Structures

The critical nature of the alkali-silica reaction (ASR) on premature concrete deterioration requires the quantitative assessment, in time and space, of the chemomechanical impact of ASR expansion on the dimensional stability of concrete structures. In particular, the coupled problem of heat diffusion and ASR kinetics can be critical, as the ASR is a thermoactivated chemical reaction. The quantitative analysis of these coupled effects on both material and structural level is the main objective of this paper. Starting from the governing micromechanisms of ASR expansion, a chemoelastic model is developed that accounts for ASR kinetics and the swelling pressure exerted by the ASR reaction products on the skeleton. This chemoelastic model is a first-order engineering approach to capture timescale and magnitude of ASR expansion. It is shown that the realistic prediction of ASR structural effects requires the consideration of two timescales: (a) A latency time associated with the dissolution of reactive silica; and (2) a characteristic time associated with the ASR product formation. In addition, a dimensional analysis of the governing equations reveals that the ASR deterioration of “massive” concrete structures is driven by the simultaneous activation of heat diffusion and reaction kinetics within a surface layer defined by a characteristic ASR heat diffusion length. In turn, in “slender” structures, it is the simultaneous activation of moisture diffusion and ASR kinetics that drives the surface layer delamination. This is illustrated through finite-element case studies of ASR effects in structures of different dimensions: a concrete gravity dam and a bridge box girder.     

Systems redesign in rehabilitation

A performance improvement team overhauled its facility's rehabilitation systems. A rehabilitation care plan was revised and an integrated assessment reduced 29 pages of documentation to 17 pages. Case management goals and documentation are integrated into one care plan.     

Preliminary Assessment and Rating of Stream Channel Stability near Bridges

The primary cause of bridge failure in the United States is scour and channel instability around the bridge foundations. The ability to assess channel stability in the vicinity of bridges is needed to alert engineers to possible unstable conditions at the bridge foundations, to design stable road crossings, and to mitigate against erosion at those structures. This information is valuable for stream stabilization projects as well, particularly for cases where the reach to be restored includes a bridge. However, a systematic methodology for rapidly assessing channel stability that is applicable at bridges located in the various regions of the country does not currently exist. In this study, an assessment method for the preliminary documentation and rating of channel stability near bridges was developed, based on prior stability assessment methods as well as observations at bridges in 13 physiographic regions of the continental United States. This method provides an assessment of channel stability conditions as they affect bridge foundations. It is intended for a quick assessment of conditions for the purpose of documenting conditions at bridges and for judging whether more extensive geomorphic studies or complete hydraulic and sediment transport analyses are needed to assess the potential for adverse conditions developing at a particular bridge in the future.     

Riemann Solvers with Runge–Kutta Discontinuous Galerkin Schemes for the 1D Shallow Water Equations

The spectrum of this survey turns on the evaluation of some eminent Riemann solvers (or the so-called solver), for the shallow water equations, when employed with high-order Runge–Kutta discontinuous Galerkin (RKDG) methods. Based on the assumption that: The higher is the accuracy order of a numerical method, the less crucial is the choice of Riemann solver; actual literature rather use the Lax-Friedrich solver as it is easy and less costly, whereas many others could be also applied such as the Godunov, Roe, Osher, HLL, HLLC, and HLLE. In practical applications, the flow can be dominated by geometry, and friction effects have to be taken into consideration. With the intention of obtaining a suitable choice of the Riemann solver function for high-order RKDG methods, a one-dimensional numerical investigation was performed. Three traditional hydraulic problems were computed by this collection of solvers cooperated with high-order RKDG methods. A comparison of the performance of the solvers was carried out discussing the issue of L1-errors magnitude, CPU time cost, discontinuity resolution and source term effects.     

Chemo-Mechanical Effects in Mortar Beams Subjected to Water Hydrolysis

Reliable predictions of the long-term behavior of concrete structures require both an accurate knowledge of the various degradation mechanisms that affect the structures over their lifetime and the use of simulation tools. Leaching due to aggressive water can be responsible for a loss of mechanical properties and stability of concrete structures. This paper focuses on coupled chemo-mechanical effects on concrete structures subjected to aggressive water inducing calcium leaching. Experimental investigations on mortar bending beams and their analysis are detailed. The response of leached mortar beams is deduced from these tests. It is found that the stiffness of mortar decreases, along with its strength, as the chemical attack progresses. The size effect on geometrically similar bending beams at various stages of degradation is studied experimentally. Due to leaching, the brittleness of the structures is increased and the fracture energy decreases.     

Tank Simulation for the Optimization of Water Distribution Networks

In this paper an original approach to the simulation of floating-on-the-system tanks as decision variables for water distribution system design optimization is presented, aiming to bridge the gap between traditional engineering practice and mathematical considerations needed for genetic algorithms (GAs). The paper includes a systematic and detailed critical overview of various mathematical approaches in literature, as well as a novel, more “engineering oriented” approach to the simulation of tanks as decision variables for water distribution system design optimization, describing in detail assumptions and impacts to the evaluation of potential solutions. Tank simulation is based on two decision variables: capacity and minimum normal operational level, omitting risers. Shape and ratio between emergency/total capacities are taken into consideration as design parameters. Assessment of tank performance is carried out by four criteria for the normal daily operational cycle, differentiating between operational and filling capacity, as well as two further criteria for emergency flows. The original design and operational mathematical assumptions are implemented in a fuzzy multiobjective GA model, which is applied to the well-known example from literature “Anytown” water distribution network to benchmark the results.