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Sample records for prevent structural failures

  1. Causes and prevention of structural materials failures in naval environments

    Energy Technology Data Exchange (ETDEWEB)

    Agarwala, V.S.; Berman, D.A.; Kohlhaas, G.

    1985-06-01

    An analysis is made of most corrosion-related, naval aircraft, structural materials failure problems. The phenomena of stress corrosion cracking, hydrogen or environmental cracking, corrosion fatigue, and exfoliation corrosion are discussed. Methods of determining hydrogen embrittling effects and hydrogen concentration are related to sustained-load tolerances of cadmium plated high strength steels. An electromechanical test is described to illustrate the hydrogen-induced elastic deformation effect in steels. This test procedure has also been used to calculate the hydrogen diffusion coefficient as well as hydrogen concentration. A technique which can monitor corrosivity of the naval environment aboard ship has been reported. Metallurgical methods of mitigating corrosion, such as heat treatment and alloy development, are described. Mechanistic aspects of corrosion-assisted mechanical failures (cracking) are analyzed and a multidisciplinary approach to solve the problem is described. It is demonstrated that modifications of the crack-tip chemistry can effectively lead to inhibition of corrosion fatigue and stress corrosion cracking in high strength alloy.

  2. Failure analysis and failure prevention in electric power systems

    International Nuclear Information System (INIS)

    Rau, C.A. Jr.; Becker, D.G.; Besuner, P.M.; Cipolla, R.C.; Egan, G.R.; Gupta, P.; Johnson, D.P.; Omry, U.; Tetelman, A.S.; Rettig, T.W.; Peters, D.C.

    1977-01-01

    New methods have been developed and applied to better quantify and increase the reliability, safety, and availability of electric power plants. Present and potential problem areas have been identified both by development of an improved computerized data base of malfunctions in nuclear power plants and by detailed metallurgical and mechanical failure analyses of selected problems. Significant advances in the accuracy and speed of structural analyses have been made through development and application of the boundary integral equation and influence function methods of stress and fracture mechanics analyses. The currently specified flaw evaluation procedures of the ASME Boiler and Pressure Vessel Code have been computerized. Results obtained from these procedures for evaluation of specific in-service inspection indications have been compared with results obtained utilizing the improved analytical methods. Mathematical methods have also been developed to describe and analyze the statistical variations in materials properties and in component loading, and uncertainties in the flaw size that might be passed by quality assurance systems. These new methods have been combined to develop accurate failure rate predictions based upon probabilistic fracture mechanics. Improved failure prevention strategies have been formulated by combining probabilistic fracture mechanics and cost optimization techniques. The approach has been demonstrated by optimizing the nondestructive inspection level with regard to both reliability and cost. (Auth.)

  3. Scaling of structural failure

    Energy Technology Data Exchange (ETDEWEB)

    Bazant, Z.P. [Northwestern Univ., Evanston, IL (United States); Chen, Er-Ping [Sandia National Lab., Albuquerque, NM (United States)

    1997-01-01

    This article attempts to review the progress achieved in the understanding of scaling and size effect in the failure of structures. Particular emphasis is placed on quasibrittle materials for which the size effect is complicated. Attention is focused on three main types of size effects, namely the statistical size effect due to randomness of strength, the energy release size effect, and the possible size effect due to fractality of fracture or microcracks. Definitive conclusions on the applicability of these theories are drawn. Subsequently, the article discusses the application of the known size effect law for the measurement of material fracture properties, and the modeling of the size effect by the cohesive crack model, nonlocal finite element models and discrete element models. Extensions to compression failure and to the rate-dependent material behavior are also outlined. The damage constitutive law needed for describing a microcracked material in the fracture process zone is discussed. Various applications to quasibrittle materials, including concrete, sea ice, fiber composites, rocks and ceramics are presented.

  4. Heart failure: preventing disease and death worldwide.

    Science.gov (United States)

    Ponikowski, Piotr; Anker, Stefan D; AlHabib, Khalid F; Cowie, Martin R; Force, Thomas L; Hu, Shengshou; Jaarsma, Tiny; Krum, Henry; Rastogi, Vishal; Rohde, Luis E; Samal, Umesh C; Shimokawa, Hiroaki; Budi Siswanto, Bambang; Sliwa, Karen; Filippatos, Gerasimos

    2014-09-01

    Heart failure is a life-threatening disease and addressing it should be considered a global health priority. At present, approximately 26 million people worldwide are living with heart failure. The outlook for such patients is poor, with survival rates worse than those for bowel, breast or prostate cancer. Furthermore, heart failure places great stresses on patients, caregivers and healthcare systems. Demands on healthcare services, in particular, are predicted to increase dramatically over the next decade as patient numbers rise owing to ageing populations, detrimental lifestyle changes and improved survival of those who go on to develop heart failure as the final stage of another disease. It is time to ease the strain on healthcare systems through clear policy initiatives that prioritize heart failure prevention and champion equity of care for all. Despite the burdens that heart failure imposes on society, awareness of the disease is poor. As a result, many premature deaths occur. This is in spite of the fact that most types of heart failure are preventable and that a healthy lifestyle can reduce risk. Even after heart failure has developed, premature deaths could be prevented if people were taught to recognize the symptoms and seek immediate medical attention. Public awareness campaigns focusing on these messages have great potential to improve outcomes for patients with heart failure and ultimately to save lives. Compliance with clinical practice guidelines is also associated with improved outcomes for patients with heart failure. However, in many countries, there is considerable variation in how closely physicians follow guideline recommendations. To promote equity of care, improvements should be encouraged through the use of hospital performance measures and incentives appropriate to the locality. To this end, policies should promote the research required to establish an evidence base for performance measures that reflect improved outcomes for patients

  5. On-Board Particulate Filter Failure Prevention and Failure Diagnostics Using Radio Frequency Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sappok, Alex [Filter Sensing Technologies; Ragaller, Paul [Filter Sensing Technologies; Herman, Andrew [CTS Corporation; Bromberg, L. [Massachusetts Institute of Technology (MIT); Prikhodko, Vitaly Y [ORNL; Parks, II, James E [ORNL; Storey, John Morse [ORNL

    2017-01-01

    The increasing use of diesel and gasoline particulate filters requires advanced on-board diagnostics (OBD) to prevent and detect filter failures and malfunctions. Early detection of upstream (engine-out) malfunctions is paramount to preventing irreversible damage to downstream aftertreatment system components. Such early detection can mitigate the failure of the particulate filter resulting in the escape of emissions exceeding permissible limits and extend the component life. However, despite best efforts at early detection and filter failure prevention, the OBD system must also be able to detect filter failures when they occur. In this study, radio frequency (RF) sensors were used to directly monitor the particulate filter state of health for both gasoline particulate filter (GPF) and diesel particulate filter (DPF) applications. The testing included controlled engine dynamometer evaluations, which characterized soot slip from various filter failure modes, as well as on-road fleet vehicle tests. The results show a high sensitivity to detect conditions resulting in soot leakage from the particulate filter, as well as potential for direct detection of structural failures including internal cracks and melted regions within the filter media itself. Furthermore, the measurements demonstrate, for the first time, the capability to employ a direct and continuous monitor of particulate filter diagnostics to both prevent and detect potential failure conditions in the field.

  6. Structural and failure mechanics of sandwich composites

    CERN Document Server

    Carlsson, LA; Carlsson, Leif A

    2011-01-01

    Focusing on important deformation and failure modes of sandwich structures, this volume describes the mechanics behind fracture processes. The text also reviews test methods developed for the cr, structural integrity, and failure mechanisms of sandwich structures.

  7. Preventing blood transfusion failures: FMEA, an effective assessment method.

    Science.gov (United States)

    Najafpour, Zhila; Hasoumi, Mojtaba; Behzadi, Faranak; Mohamadi, Efat; Jafary, Mohamadreza; Saeedi, Morteza

    2017-06-30

    Failure Mode and Effect Analysis (FMEA) is a method used to assess the risk of failures and harms to patients during the medical process and to identify the associated clinical issues. The aim of this study was to conduct an assessment of blood transfusion process in a teaching general hospital, using FMEA as the method. A structured FMEA was recruited in our study performed in 2014, and corrective actions were implemented and re-evaluated after 6 months. Sixteen 2-h sessions were held to perform FMEA in the blood transfusion process, including five steps: establishing the context, selecting team members, analysis of the processes, hazard analysis, and developing a risk reduction protocol for blood transfusion. Failure modes with the highest risk priority numbers (RPNs) were identified. The overall RPN scores ranged from 5 to 100 among which, four failure modes were associated with RPNs over 75. The data analysis indicated that failures with the highest RPNs were: labelling (RPN: 100), transfusion of blood or the component (RPN: 100), patient identification (RPN: 80) and sampling (RPN: 75). The results demonstrated that mis-transfusion of blood or blood component is the most important error, which can lead to serious morbidity or mortality. Provision of training to the personnel on blood transfusion, knowledge raising on hazards and appropriate preventative measures, as well as developing standard safety guidelines are essential, and must be implemented during all steps of blood and blood component transfusion.

  8. Mechanics of Failure Mechanisms in Structures

    CERN Document Server

    Carlson, R L; Craig, J I

    2012-01-01

    This book focuses on the mechanisms and underlying mechanics of failure in various classes of materials such as metallic, ceramic, polymeric, composite and bio-material.  Topics include tensile and compressive fracture, crack initiation and growth, fatigue and creep rupture in metallic materials, matrix cracking and delamination and environmental degradation in polymeric composites, failure of bio-materials such as prosthetic heart valves and prosthetic hip joints, failure of ceramics and ceramic matrix composites, failure of metallic matrix composites, static and dynamic buckling failure, dynamic excitations and creep buckling failure in structural systems. Chapters are devoted to failure mechanisms that are characteristic of each of the materials.  The work also provides the basic elements of fracture mechanics and studies in detail several niche topics such as the effects of toughness gradients, variable amplitude loading effects in fatigue, small fatigue cracks, and creep induced brittleness. Furthe...

  9. Case studies of steel structure failures

    Directory of Open Access Journals (Sweden)

    P. Bernasovský

    2010-01-01

    Full Text Available The contribution deals with some case studies of steel structure failures, which happened in Slovakia a few years ago. Features of cracking are illustrated on real cases of breakdowns in the transmission gas pipelines, at the cement works and in the petrochemical indus-try. All failures were caused by an incorrect technical approach. Possible remedial measures are proposed.

  10. Structures for common-cause failure analysis

    International Nuclear Information System (INIS)

    Vaurio, J.K.

    1981-01-01

    Common-cause failure methodology and terminology have been reviewed and structured to provide a systematical basis for addressing and developing models and methods for quantification. The structure is based on (1) a specific set of definitions, (2) categories based on the way faults are attributable to a common cause, and (3) classes based on the time of entry and the time of elimination of the faults. The failure events are then characterized by their likelihood or frequency and the average residence time. The structure provides a basis for selecting computational models, collecting and evaluating data and assessing the importance of various failure types, and for developing effective defences against common-cause failure. The relationships of this and several other structures are described

  11. Acute heart failure: Epidemiology, risk factors, and prevention.

    Science.gov (United States)

    Farmakis, Dimitrios; Parissis, John; Lekakis, John; Filippatos, Gerasimos

    2015-03-01

    Acute heart failure represents the first cause of hospitalization in elderly persons and is the main determinant of the huge healthcare expenditure related to heart failure. Despite therapeutic advances, the prognosis of acute heart failure is poor, with in-hospital mortality ranging from 4% to 7%, 60- to 90-day mortality ranging from 7% to 11%, and 60- to 90-day rehospitalization from 25% to 30%. Several factors including cardiovascular and noncardiovascular conditions as well as patient-related and iatrogenic factors may precipitate the rapid development or deterioration of signs and symptoms of heart failure, thus leading to an acute heart failure episode that usually requires patient hospitalization. The primary prevention of acute heart failure mainly concerns the prevention, early diagnosis, and treatment of cardiovascular risk factors and heart disease, including coronary artery disease, while the secondary prevention of a new episode of decompensation requires the optimization of heart failure therapy, patient education, and the development of an effective transition and follow-up plan. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  12. Current strategies for preventing renal dysfunction in patients with heart failure: a heart failure stage approach

    Science.gov (United States)

    Issa, Victor Sarli; Andrade, Lúcia; Bocchi, Edimar Alcides

    2013-01-01

    Renal dysfunction is common during episodes of acute decompensated heart failure, and historical data indicate that the mean creatinine level at admission has risen in recent decades. Different mechanisms underlying this change over time have been proposed, such as demographic changes, hemodynamic and neurohumoral derangements and medical interventions. In this setting, various strategies have been proposed for the prevention of renal dysfunction with heterogeneous results. In the present article, we review and discuss the main aspects of renal dysfunction prevention according to the different stages of heart failure. PMID:23644863

  13. A Tool for Preventing Teamwork Failure: the TFP Questionnaire

    DEFF Research Database (Denmark)

    Qvist, Palle; Rebollar, Rubeén; Lidón, Iván

    2010-01-01

    This paper presents the process used to devise the Teamwork Failure Prevention Questionnaire (TFP Questionnaire), a tool that allows teams with problems in functioning to be detected early. The TFP Questionnaire was formulated in a project management course at the University of Zaragoza (Spain...

  14. Chemical cleaning's role in tube failure prevention and correction

    International Nuclear Information System (INIS)

    Shields, K.J.; Dooley, R.B.

    2002-01-01

    Properly applied, chemical cleaning is a valuable tool used to prevent tube failures involving overheating and corrosion due to waterside deposits. In many cases, however, cleaning becomes yet an additional cost associated with correction of tube failure incidents. Discussion is focused on approaches taken to appraise tube waterside cleanliness and determine the need to clean, as typically practiced in conventional fossil plants. Also presented is an assessment of the suitability and limitations of these approaches to plants with heat recovery steam generator (HRSG) units. (orig.)

  15. Structural Bases of Postresuscitative Heart Failure

    Directory of Open Access Journals (Sweden)

    V. T. Dolgikh

    2005-01-01

    Full Text Available An experiment on 106 non-inbred male albino rats undergone 4-minute clinical death from acute blood loss has revealed that the first three days after resuscitation are marked by a concomitance of vascular disorders and cardiomyocytic dystrophic changes, the leading role being played by sludge, stasis, thrombosis, increased vascular permeability, perivascular edema, and hemorrhages. Cardiomyocytic destruction (various contractures, block-like myofibrillolysis, myocytoly-sis is a structural basis of postresuscitative heart failure. Three days later the heart displayed concomitant processes of recovery and damage. Three types of cardiac morphological changes have been identified in relation to the ratio of these processes.

  16. Dispersed Trading and the Prevention of Market Failure

    DEFF Research Database (Denmark)

    Porter, David C.; Tanggaard, Carsten; G. Weaver, Daniel

    With augmented demands on power grids resulting in longer and larger blackouts combined with heightened concerns of terrorist attacks, trading institutions and policy makers have widened their search for systems that avoid market failure during these disturbing events. We provide insight...... into this issue by examining trading behavior at the Copenhagen Stock Exchange during a major blackout. We find that although market quality declined, markets remained functional and some price discovery occurred during the blackout period suggesting that the NOREX structure of interlinked trading systems...... combined with widely dispersed trading locations may be a viable means of protection against market failure during massive power disruptions or terrorist attacks....

  17. Expanded Polytetrafluoroethylene for Chordal Replacement: Preventing Knot Failure.

    Science.gov (United States)

    Miller, Jacob R; Deeken, Corey R; Ray, Shuddhadeb; Henn, Matthew C; Lancaster, Timothy S; Schuessler, Richard B; Damiano, Ralph J; Melby, Spencer J

    2015-12-01

    Expanded polytetrafluoroethylene suture is commonly used for chordal replacement in mitral valve repair, but due to material characteristics, knots can unravel. Our aim was to determine the knot security, including how many throws are necessary to prevent knot failure, with Gore-Tex (W.L. Gore and Associates, Elkton, MD) and the newly available Chord-X (On-X Life Technologies Inc, Austin, TX). Knots were evaluated for maximal load based on: number of throws (6, 8, 10, and 12), tension to secure each throw (10%, 50%, and 85%) and suture type (Gore-Tex CV-5 and Chord-X 3-0). A physiologic force of 2 N was used for comparison. We evaluated 240 knots. For all knots, the mean load to failure was 11.1 ± 5.8 N. Failure occurred due to unraveling in 141 knots (59%) at 7.1 ± 4.1 N and to breaking in 99 (41%) at 16.7 ± 2.0 N (p Gore-Tex failed at higher loads (12.6 ± 6.0 N vs 9.5 ± 5.2 N, p Gore-Tex and 6 Chord-X, unraveled at 2 N, all with fewer than 10 throws. Expanded polytetrafluoroethylene has adequate strength to prevent breakage; however, a risk of knot unraveling at physiologic conditions exists when fewer than 10 throws are performed. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Rock Failure Criteria for Design of Underground Structural Supports.

    Science.gov (United States)

    1985-09-01

    UNDERGROUND STRUCTURAL SUPPORTS PART I: INTRODUCTION Background Failure Criteria Bieniawski (1984) defines a criterion of failure as "an algebraic expres...of load, deformation, stress, strain, or other parameters." Bieniawski listed no less than fourteen failure criteria that have been used in the past...failure. Bieniawski (1984) is of the opinion that to meet the immediate needs of the practical rock engineer, attention should be directed to empiri- cal

  19. An estimation method of system failure frequency using both structure and component failure data

    International Nuclear Information System (INIS)

    Takaragi, Kazuo; Sasaki, Ryoichi; Shingai, Sadanori; Tominaga, Kenji

    1981-01-01

    In recent years, the importance of reliability analysis is appreciated for large systems such as nuclear power plants. A reliability analysis method is described for a whole system, using structure failure data for its main working subsystem and component failure data for its safety protection subsystem. The subsystem named main working system operates normally, and the subsystem named safety protection system acts as standby or protection. Thus the main and the protection systems are given mutually different failure data; then, between the subsystems, there exists common mode failure, i.e. the component failure affecting the reliability of both two. A calculation formula for sytem failure frequency is first derived. Then, a calculation method with digraphs is proposed for conditional system failure probability. Finally the results of numerical calculation are given for the purpose of explanation. (J.P.N.)

  20. Preoperative Prevention of Heart Failure in Noncardiac Surgery

    Directory of Open Access Journals (Sweden)

    V. V. Likhvantsev

    2016-01-01

    Full Text Available Congestive heart failure is consistently associated with adverse outcomes, and is characterized by a twofold increase in mortality in noncardiac surgery. In this regard, developing the methods aimed to prevent and treatacute heart failure (AHF in the intraoperative period remain a challenging problem.Objective. To evaluate the efficacy of preoperative levosimendan infusion in reduction both mortality and duration of treatment of elderly patients with reduced left ventricular ejection fraction in noncardiac surgery.Material and Methods. Design: Multicenter blind randomized placebocontrolled study. Patients: 81 patients operated on abdominal organs. The main endpoint of the study: The length of stay in the Intensive Care Unit (ICU and at the hospital were chosen as the primary endpoints. The secondary endpoints of the study were 30 day and annual mortality, the rate of acute myocardial infarction and stroke.Results. Levosimendan infusion at a rate of 0,05 μg/kg/min — 0,1 μg/kg/min to patients with low left ven tricular ejection fraction just before the surgery reduced the length of stay in ICU for 2 days and required hospital stay for 3 days. NTproBNP showed the best ratio of sensitivity/specificity in predicting 30day mortality in cumulative group: AUC=0,86 (90,77 to 0,93, P<0,0001. From other indicators the most informative were the Inotropes scoring, no change or decrease of a left ventricular ejection fraction, and cardiac index.Conclusion. To reduce perioperative mortality, the intravenous infusion of levosimendan at a rate of 0,05—0,1 μg/kg/min in elderly patients with low left ventricular ejection fraction is recommened as a preoperative preparation the day before the alleged noncardiac surgery.

  1. Damage and failure processes in structural materials

    International Nuclear Information System (INIS)

    Embury, J.D.

    1993-01-01

    At large plastic strains consideration must be given not only to the descriptions of work hardening and texture evolution but also to the process of damage accumulation and the documentation of the various modes of failure which may terminate the plastic history. In this presentation consideration is given first to documenting the various modes of failure and their dependence on stress state. It is then shown that damage accumulation can be studied in a quantitative manner by using model systems in conjunction with FEM calculations. Finally consideration is given to complex forming processes such as ironing to show how studies of damage initiation and accumulation relate to practical engineering problems. (orig.)

  2. On-clip high frequency reliability and failure test structures

    Science.gov (United States)

    Snyder, Eric S.; Campbell, David V.

    1997-01-01

    Self-stressing test structures for realistic high frequency reliability characterizations. An on-chip high frequency oscillator, controlled by DC signals from off-chip, provides a range of high frequency pulses to test structures. The test structures provide information with regard to a variety of reliability failure mechanisms, including hot-carriers, electromigration, and oxide breakdown. The system is normally integrated at the wafer level to predict the failure mechanisms of the production integrated circuits on the same wafer.

  3. Stormwater Volume Control to Prevent Increases in Lake Flooding and Dam Failure Risk

    Science.gov (United States)

    Potter, K. W.

    2017-12-01

    Urban expansion is not often considered a major factor contributing to dam failure. But if urbanization occurs without mitigation of the hydrologic impacts, the risk of dam failure will increase. Of particular concern are increases in the volume of storm runoff resulting from increases in the extent of impervious surfaces. Storm runoff volumes are not regulated for much the U.S, and where they are, the required control is commonly less than 100%. Unmitigated increases in runoff volume due to urbanization can pose a risk to dams. A recent technical advisory committee of Dane County has recommended that the county require 100% control of stormwater volumes for new developments. The primary motivation was to prevent increases in the water levels in the Yahara Lakes, slowly draining lakes that are highly sensitive to runoff volume. The recommendations included the use of "volume trading" to achieve efficient compliance. Such recommendations should be considered for other slowly draining lakes, including those created by artificial structures.

  4. Progressive failure analysis of fibrous composite materials and structures

    Science.gov (United States)

    Bahei-El-din, Yehia A.

    1990-01-01

    A brief description is given of the modifications implemented in the PAFAC finite element program for the simulation of progressive failure in fibrous composite materials and structures. Details of the memory allocation, input data, and the new subroutines are given. Also, built-in failure criteria for homogeneous and fibrous composite materials are described.

  5. Electrical failure during cardiopulmonary bypass: an evaluation of incidence, causes, management and guidelines for preventative measures.

    LENUS (Irish Health Repository)

    Hargrove, M

    2012-02-03

    The incidence of electrical failure during cardiopulmonary bypass (CPB) has been reported to occur in approximately 1 per 1000 cases. While the resultant morbidity and mortality is low, electrical failure is a life-threatening scenario. We report three major electrical failures during CPB in a patient population of 3500 over a 15-year period. These cases involved mains failure and generator shut down, mains failure and generator power surge, and failure of the uninterruptable power supply (UPS), which caused protected sockets to shut down. Protocols for preventative maintenance, necessary equipment, battery backup and guidelines for the successful management of such accidents during CPB are discussed.

  6. Boiler tube failure prevention in fossil fired boilers

    International Nuclear Information System (INIS)

    Townsend, R.D.

    1993-01-01

    It is the common experience of power generating companies worldwide that the main causes of forced outages on power plant are those due to boiler tube failures on fossil units. The main reason for the large number of failures are the severe environmental conditions in fossil boilers as the effects of stress, temperature, temperature gradients, corrosion, erosion and vibration combine to produce degradation of the tube steel. Corrosion by oxidation, by combustion products and by impure boiler water can significantly reduce the tube wall thickness and result in failure of a tube many years before its designed service life. Errors can also occur in the design manufacturer, storage, operation, and maintenance of boiler tubing and the wrong material installed in a critical location can lead to premature failure. Altogether, experts in the US and UK, from many different disciplines, have identified seven broad categories of boiler tube failure mechanisms. 1 tab., 2 figs

  7. Dynamic Failure of Composite and Sandwich Structures

    CERN Document Server

    Abrate, Serge; Rajapakse, Yapa D S

    2013-01-01

    This book presents a broad view of the current state of the art regarding the dynamic response of composite and sandwich structures subjected to impacts and explosions. Each chapter combines a thorough assessment of the literature with original contributions made by the authors.  The first section deals with fluid-structure interactions in marine structures.  The first chapter focuses on hull slamming and particularly cases in which the deformation of the structure affects the motion of the fluid during the water entry of flexible hulls. Chapter 2 presents an extensive series of tests underwater and in the air to determine the effects of explosions on composite and sandwich structures.  Full-scale structures were subjected to significant explosive charges, and such results are extremely rare in the open literature.  Chapter 3 describes a simple geometrical theory of diffraction for describing the interaction of an underwater blast wave with submerged structures. The second section addresses the problem of...

  8. Tools for in service monitoring and testing of riser to prevent failure and extend service life

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Haakon; Bondevik, Jon Olav; Skjerve, Haavard; Tveit, Oeyvind [SeaFlex AS, Asker (Norway)

    2005-07-01

    Exploration and development of new oil and gas fields is heavily dependant on use of flexible pipes and many field developments would not have been possible without them. The number of flexible risers in service is constantly increasing since relatively few offshore projects have reached the estimated operational life and the operational lifetime of several fields in-service has been extended due to new and improved technology. Many risers have been in service over a large number of years. Some risers have been operated under demanding conditions such as severe dynamic loads, high pressure and temperatures. One may in some cases find that risers actually have shorter service life than estimated in the design phase due to the severe operational conditions. In order to extend the use of the riser, some risers may have to be modified and re-terminated and prepared for a new and less demanding application. In order to operate risers safely, it is important to re-assess the fatigue life in order to prevent potential riser failure. The operator should implement methods and tools for in-service monitoring and testing. This paper addresses efficient and reliable methods and tools for monitoring of critical operational parameters as well as in-service riser testing. A brief description of structural failure modes will also be given in order to understand how to interpret test results in view of potential failure modes. (author)

  9. Analyses Of Techniques On Structural Fatigue Failure Detection ...

    African Journals Online (AJOL)

    Machines and structures are subjected to variable loading conditions where the stress cycle does not remain the same during the operation of the machine. Fatigue is undoubtedly one of the most serious of all causes of breakdowns of machines and structures which results in sudden failures. The use of the time domain ...

  10. Hydrogen permeation preventive structural materials

    International Nuclear Information System (INIS)

    Fukushima, Kimichika; Nakahigashi, Shigeo; Imura, Masashi; Terasawa, Michitaka; Ebisawa, Katsuyuki.

    1986-01-01

    Purpose: To provide highly practical wall materials for use in thermonuclear reactors capable of effectively preventing the permeation of hydrogen isotopes such as tritium thereby preventing the contamination of coolants. Constitution: Helium gas is injected into or at the surface of base materials comprising stainless steel plates to form a helium gas region. Alternatively, boron, nitrogen or the compound thereof having a greater helium forming nuclear reaction cross section than that of the base materials is mixed or injected into the base material to form the helium gas region through (n,α) reaction under neutron irradiation. Since the helium gas region constitutes a diffusion barrier for the tritium as the hydrogen isotope, the permeation amount of tritium is significantly suppressed. Helium gas bubbles or lattice defects are formed in the helium gas region under the neutron irradiation, by which the hydrogen isotope capturing effect can also be effected. In this way, permeation of the hydrogen isotope, contamination of the coolants, etc. can be prevented to provide great practical effectives. (Kawakami, Y.)

  11. Failure and preventive costs of mastitis on Dutch dairy farms

    NARCIS (Netherlands)

    Soest, van Felix J.S.; Santman-Berends, Inge M.G.A.; Lam, Theo J.G.M.; Hogeveen, Henk

    2016-01-01

    Mastitis is an important disease from an economic perspective, but most cost assessments of mastitis include only the direct costs associated with the disease (e.g., production losses, culling, and treatment), which we call failure costs (FC). However, farmers also invest time and money in

  12. Failure and preventive costs of mastitis on Dutch dairy farms

    NARCIS (Netherlands)

    van Soest, Felix J S; Santman-Berends, Inge M G A; Lam, Theo J G M|info:eu-repo/dai/nl/14686820X; Hogeveen, Henk

    2016-01-01

    Mastitis is an important disease from an economic perspective, but most cost assessments of mastitis include only the direct costs associated with the disease (e.g., production losses, culling, and treatment), which we call failure costs (FC). However, farmers also invest time and money in

  13. Distributed monitoring for the prevention of cascading failures in operational power grids

    NARCIS (Netherlands)

    M.E. Warnier (Martijn); S.O. Dulman (Stefan); Y. Koç (Yakup); E.J. Pauwels (Eric)

    2017-01-01

    textabstractElectrical power grids are vulnerable to cascading failures that can lead to large blackouts. The detection and prevention of cascading failures in power grids are important problems. Currently, grid operators mainly monitor the states (loading levels) of individual components in a power

  14. Failure mechanisms in energy-absorbing composite structures

    Science.gov (United States)

    Johnson, Alastair F.; David, Matthew

    2010-11-01

    Quasi-static tests are described for determination of the energy-absorption properties of composite crash energy-absorbing segment elements under axial loads. Detailed computer tomography scans of failed specimens were used to identify local compression crush failure mechanisms at the crush front. These mechanisms are important for selecting composite materials for energy-absorbing structures, such as helicopter and aircraft sub-floors. Finite element models of the failure processes are described that could be the basis for materials selection and future design procedures for crashworthy structures.

  15. Advanced composites structural concepts and materials technologies for primary aircraft structures: Structural response and failure analysis

    Science.gov (United States)

    Dorris, William J.; Hairr, John W.; Huang, Jui-Tien; Ingram, J. Edward; Shah, Bharat M.

    1992-01-01

    Non-linear analysis methods were adapted and incorporated in a finite element based DIAL code. These methods are necessary to evaluate the global response of a stiffened structure under combined in-plane and out-of-plane loading. These methods include the Arc Length method and target point analysis procedure. A new interface material model was implemented that can model elastic-plastic behavior of the bond adhesive. Direct application of this method is in skin/stiffener interface failure assessment. Addition of the AML (angle minus longitudinal or load) failure procedure and Hasin's failure criteria provides added capability in the failure predictions. Interactive Stiffened Panel Analysis modules were developed as interactive pre-and post-processors. Each module provides the means of performing self-initiated finite elements based analysis of primary structures such as a flat or curved stiffened panel; a corrugated flat sandwich panel; and a curved geodesic fuselage panel. This module brings finite element analysis into the design of composite structures without the requirement for the user to know much about the techniques and procedures needed to actually perform a finite element analysis from scratch. An interactive finite element code was developed to predict bolted joint strength considering material and geometrical non-linearity. The developed method conducts an ultimate strength failure analysis using a set of material degradation models.

  16. Methods for preventing steam generator failure or degradation

    International Nuclear Information System (INIS)

    Green, S.J.

    1986-01-01

    PWR steam generators have suffered from a variety of degradation phenomena. This paper identifies the corrosion-related defects and their probable causes and suggests approaches to correct and prevent corrosive activity. In the attempt to solve the degradation problems, research programs have concentrated on modifying materials, stresses, and the chemical environment in both new and operating steam generators. The following corrosion-related defects have been studied: tube wastage, denting, primary side (ID) intergranular stress corrosion cracking (IGSCC), OD-initiated intergranular attack (IGA), pitting, and corrosion fatigue. Plants affected by wastage have greatly reduced their problem by adopting an all volatile treatment (AVT). In the case of denting, a less aggressive chemical environment is recommended. Primary side IGSCC responds to temperature reduction, stress relief, and material improvements, while flushing and boric acid addition minimizes OD-initiated IGA. It has further been shown that pitting can be minimized by sludge lancing and by reducing impurity ingress. (author)

  17. Module failure isolation circuit for paralleled inverters. [preventing system failure during power conditioning for spacecraft applications

    Science.gov (United States)

    Nagano, S. (Inventor)

    1979-01-01

    A module failure isolation circuit is described which senses and averages the collector current of each paralled inverter power transistor and compares the collector current of each power transistor the average collector current of all power transistors to determine when the sensed collector current of a power transistor in any one inverter falls below a predetermined ratio of the average collector current. The module associated with any transistor that fails to maintain a current level above the predetermined radio of the average collector current is then shut off. A separate circuit detects when there is no load, or a light load, to inhibit operation of the isolation circuit during no load or light load conditions.

  18. Dispersed trading and the prevention of market failure

    DEFF Research Database (Denmark)

    Porter, David C.; Tanggaard, Carsten; Weaver, Daniel G.

    2008-01-01

    into this issue by examining trading behaviour at the Copenhagen Stock Exchange during a major blackout. We find that although market quality declined, markets remained functional and some price discovery occurred during the blackout period suggesting that the NOREX structure of interlinked trading systems...

  19. A unified approach to failure assessment of engineering structures

    International Nuclear Information System (INIS)

    Harrison, R.P.

    1977-01-01

    A codified procedure for the failure assessment of engineering structures is presented which has as its basis the two criteria approach of Dowling and Townley (Int. J. Press. Vessels and Piping; 3:77 (1975)) and the Bilby, Cottrell and Swinden (Proc. R. Soc.; A272:304 (1963)) and Dugdale (J. Mech. Phys. Sol.; 8:100 (1960)) model of yielding ahead of a crack tip. The procedure consists of independently assessing the risk of failure (a) under linear elastic conditions only and (b) under plastic collapse conditions only. These two limiting criteria are then plotted as a co-ordinate point on a Failure Assessment Diagram. From this a measure of the degree of safety of the structure can be obtained. As examples, several of the HSST vessel tests are used to indicate the simplicity and versatility of the procedure. It is shown how maximum allowable pressures or defect sizes can be obtained and how safety factors can be readily incorporated on any of the parameters used in the assessment. It is also demonstrated how helpful the procedure is in designing not only working structures, but also structures that are to be used for testing. (author)

  20. A multicentre randomized controlled trial of moderate hypothermia to prevent intracranial hypertension in acute liver failure

    DEFF Research Database (Denmark)

    Bernal, William; Murphy, Nicholas; Brown, Sarah

    2016-01-01

    BACKGROUND & AIMS: Animal models and human case series of acute liver failure (ALF) suggest moderate hypothermia (MH) to have protective effects against cerebral oedema (CO) development and intracranial hypertension (ICH). However, the optimum temperature for patient management is unknown...... above management at 36°C in prevention of ICH or in overall survival. This study did not confirm advantage of its prophylactic use. (ISRCTN registration number 74268282; no funding.) LAY SUMMARY: Studies in animals with acute liver failure (ALF) have suggested that cooling (hypothermia) could prevent...

  1. Predicting and preventing organizational failure: learning, stability and safety culture

    International Nuclear Information System (INIS)

    Duffey, R.B.

    2009-01-01

    The physical definition of 'safety culture' is the creation of an organizational and operational structure that places unending emphasis on safety at every level. We propose and prefer the use of the term and the objective of sustaining a 'Learning Environment', where mistakes, outcomes and errors are used as learning vehicles to improve, and we can now define why that is true. Therefore we can manage and quantify safety effectively tracking and analyzing outcomes, using the trends to guide our needed organizational behaviors. (author)

  2. Structuring free form verbal descriptions in equipment failure reports

    International Nuclear Information System (INIS)

    Huzdovich, J.

    1983-01-01

    Information is encoded for convenience in computer sort/search routines used to manage a large number of records. The codes in use for equipment failure reports are limited due to practical considerations, and this limitation forces the reporter to leave out information to satisfy the coding requirements. The free form verbal descriptions, as found in the Generating Availability Data System (GADS) and the Nuclear Plant Reliability Data System (NPRDS), allow for reporting of this non-codable information. A systematic approach to constructing the verbal description based on rules of grammar, especially syntax, results in a structured narrative suitable for computer data management schemes. In addition, the reporter has a full range of descriptive terminology and does not have to select subjectively from a predetermined, limited vocabulary to describe the event. This paper introduces a concept that places in perspective the integration of structured, formal reporting and free form verbal description. A second benefit of this structured narrative is the systematic development of failure mode/failure cause relationships in the event

  3. MEMS Reliability: Infrastructure, Test Structures, Experiments, and Failure Modes

    Energy Technology Data Exchange (ETDEWEB)

    TANNER,DANELLE M.; SMITH,NORMAN F.; IRWIN,LLOYD W.; EATON,WILLIAM P.; HELGESEN,KAREN SUE; CLEMENT,J. JOSEPH; MILLER,WILLIAM M.; MILLER,SAMUEL L.; DUGGER,MICHAEL T.; WALRAVEN,JEREMY A.; PETERSON,KENNETH A.

    2000-01-01

    The burgeoning new technology of Micro-Electro-Mechanical Systems (MEMS) shows great promise in the weapons arena. We can now conceive of micro-gyros, micro-surety systems, and micro-navigators that are extremely small and inexpensive. Do we want to use this new technology in critical applications such as nuclear weapons? This question drove us to understand the reliability and failure mechanisms of silicon surface-micromachined MEMS. Development of a testing infrastructure was a crucial step to perform reliability experiments on MEMS devices and will be reported here. In addition, reliability test structures have been designed and characterized. Many experiments were performed to investigate failure modes and specifically those in different environments (humidity, temperature, shock, vibration, and storage). A predictive reliability model for wear of rubbing surfaces in microengines was developed. The root causes of failure for operating and non-operating MEMS are discussed. The major failure mechanism for operating MEMS was wear of the polysilicon rubbing surfaces. Reliability design rules for future MEMS devices are established.

  4. Thermal stress failure criteria for a structural epoxy

    Science.gov (United States)

    Côté, Patrice; Desnoyers, Nichola

    2011-09-01

    Representative failure data for structural epoxies can be very difficult to find for the optomechanical engineer. Usually, test data is only available for shear configuration at room temperature and fast pull rate. On the other hand, the slowly induced stress at extreme temperature is for many optical systems the worse-case scenario. Since one of the most referenced epoxy for optical assembly is the 3M™ Scotch-Weld™ Epoxy Adhesive EC-2216 B/A Gray, better understanding its behavior can benefit a broad range of applications. The objective of this paper is two-fold. First, review data for critical parameters such as Young's modulus and coefficient of thermal expansion. Secondly, derive failure criteria from correlation between a thermal stress experiment and a finite element model. Instead of pulling out a standard tensile specimen, it is proposed to test thin bondline geometry to replicate an optical device usage. Four test plates are assembled at the Institut National d'Optique (INO) in Quebec City, Canada with bondlines of 50 μm and 133 μm. To detect the failure of the epoxy, the low level vibration signature of a cantilever Invar plate is monitored as temperature changes. Following the finite element analysis, a failure criterion is found to better match the experimental results than generic lap shear data.

  5. Cardiac Resynchronization Therapy prevents progression of renal failure in heart failure patients.

    Science.gov (United States)

    Jeevanantham, Vinodh; Turagam, Mohit; Shanberg, David; Reddy, Madhu; Atoui, Moustapha; Daubert, James P; Dawn, Buddhadeb; Lakkireddy, Dhanunjaya

    The goal of this study is to assess the effect of cardiac resynchronization therapy (CRT) over time on renal function and its impact on mortality. The effect of CRT on renal function in patients with heart failure is not well understood. All patients who underwent CRT implantation at University of Kansas between year 2000 and 2009 were reviewed and patients who had pre and post CRT renal function studied were included in our study. Stages of chronic kidney disease (CKD) were defined based on Kidney Disease Outcome Quality Initiative (KDOQI) guidelines. The effect of CRT on renal and cardiac function were studied at short term (≤6 months post implantation) and long term (>6 months). A total of 588 patients with mean age of 67 ± 12 yrs were included in the study. CRT responders (defined by increase in LVEF ≥ 5%) were 54% during short term follow-up and 65% on long term follow-up. When compared to baseline, there was no significant deterioration in mean Glomerular Filtration Rate (GFR) during follow up. When analyzed based on the stages of CKD, there was significant improvement of renal function in patients with advanced kidney disease. Multivariate logistic regression analysis showed that stable GFR or an improvement in GFR independently predicted mortality after adjusting for co-morbidities. CRT was associated with stabilization of renal function in patients with severe LV dysfunction and improvement in stage 4 and 5 CKD. Improved renal function was associated with a lower mortality. Copyright © 2016 Indian Heart Rhythm Society. Production and hosting by Elsevier B.V. All rights reserved.

  6. [Electrical failure with nerve stimulation: cases report and check list for prevention].

    Science.gov (United States)

    Choquet, O; Feugeas, J-L; Capdevila, X; Manelli, J-C

    2007-03-01

    Functionality of the nerve stimulator and integrity of the electrical circuit should be verified and confirmed before performing peripheral nerve blockade. The clinical cases reported here demonstrate that electrical disconnection or malfunction during nerve localization can unpredictably occur and a checklist is described to prevent the unknown electrical circuit failure.

  7. Predictors of Prevention Failure in College Students Participating in Two Indicated Depression Prevention Programs

    OpenAIRE

    Blanco, Vanessa; Rohde, Paul; Vázquez, Fernando L.; Otero, Patricia

    2014-01-01

    The purpose of this study was to identify subgroups of university students with the highest likelihood of remaining at elevated levels of depressive symptoms six months following the receipt of a depressive prevention intervention on the basis of known risk factors and participation in one of two depression prevention programs. Data from a randomized controlled trial evaluating depression prevention among 133 college students with elevated depressive symptoms were analyzed. Participants were ...

  8. Intralipid prevents and rescues fatal pulmonary arterial hypertension and right ventricular failure in rats.

    Science.gov (United States)

    Umar, Soban; Nadadur, Rangarajan D; Li, Jingyuan; Maltese, Federica; Partownavid, Parisa; van der Laarse, Arnoud; Eghbali, Mansoureh

    2011-09-01

    Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling leading to right ventricular (RV) hypertrophy and failure. Intralipid (ILP), a source of parenteral nutrition for patients, contains γ-linolenic acid and soy-derived phytoestrogens that are protective for lungs and heart. We, therefore, investigated the therapeutic potential of ILP in preventing and rescuing monocrotaline-induced PAH and RV dysfunction. PAH was induced in male rats with monocrotaline (60 mg/kg). Rats then received daily ILP (1 mL of 20% ILP per day IP) from day 1 to day 30 for prevention protocol or from day 21 to day 30 for rescue protocol. Other monocrotaline-injected rats were left untreated to develop severe PAH by day 21 or RV failure by approximately day 30. Saline or ILP-treated rats served as controls. Significant increase in RV pressure and decrease in RV ejection fraction in the RV failure group resulted in high mortality. Therapy with ILP resulted in 100% survival and prevented PAH-induced RV failure by preserving RV pressure and RV ejection fraction and preventing RV hypertrophy and lung remodeling. In preexisting severe PAH, ILP attenuated most lung and RV abnormalities. The beneficial effects of ILP in PAH seem to result from the interplay of various factors, among which preservation and/or stimulation of angiogenesis, suppression and/or reversal of inflammation, fibrosis and hypertrophy, in both lung and RV, appear to be major contributors. In conclusion, ILP not only prevents the development of PAH and RV failure but also rescues preexisting severe PAH.

  9. Evaluations of Structural Failure Probabilities and Candidate Inservice Inspection Programs

    Energy Technology Data Exchange (ETDEWEB)

    Khaleel, Mohammad A.; Simonen, Fredric A.

    2009-05-01

    The work described in this report applies probabilistic structural mechanics models to predict the reliability of nuclear pressure boundary components. These same models are then applied to evaluate the effectiveness of alternative programs for inservice inspection to reduce these failure probabilities. Results of the calculations support the development and implementation of risk-informed inservice inspection of piping and vessels. Studies have specifically addressed the potential benefits of ultrasonic inspections to reduce failure probabilities associated with fatigue crack growth and stress-corrosion cracking. Parametric calculations were performed with the computer code pc-PRAISE to generate an extensive set of plots to cover a wide range of pipe wall thicknesses, cyclic operating stresses, and inspection strategies. The studies have also addressed critical inputs to fracture mechanics calculations such as the parameters that characterize the number and sizes of fabrication flaws in piping welds. Other calculations quantify uncertainties associated with the inputs calculations, the uncertainties in the fracture mechanics models, and the uncertainties in the resulting calculated failure probabilities. A final set of calculations address the effects of flaw sizing errors on the effectiveness of inservice inspection programs.

  10. [Early detection, prevention and management of renal failure in liver transplantation].

    Science.gov (United States)

    Castells, Lluís; Baliellas, Carme; Bilbao, Itxarone; Cantarell, Carme; Cruzado, Josep Maria; Esforzado, Núria; García-Valdecasas, Juan Carlos; Lladó, Laura; Rimola, Antoni; Serón, Daniel; Oppenheimer, Federico

    2014-10-01

    Renal failure is a frequent complication in liver transplant recipients and is associated with increased morbidity and mortality. A variety of risk factors for the development of renal failure in the pre- and post-transplantation periods have been described, as well as at the time of surgery. To reduce the negative impact of renal failure in this population, an active approach is required for the identification of those patients with risk factors, the implementation of preventive strategies, and the early detection of progressive deterioration of renal function. Based on published evidence and on clinical experience, this document presents a series of recommendations on monitoring RF in LT recipients, as well as on the prevention and management of acute and chronic renal failure after LT and referral of these patients to the nephrologist. In addition, this document also provides an update of the various immunosuppressive regimens tested in this population for the prevention and control of post-transplantation deterioration of renal function. Copyright © 2013 Elsevier España, S.L.U. and AEEH y AEG. All rights reserved.

  11. Regenerative Therapy Prevents Heart Failure Progression in Dyssynchronous Nonischemic Narrow QRS Cardiomyopathy

    Science.gov (United States)

    Yamada, Satsuki; Arrell, D Kent; Martinez-Fernandez, Almudena; Behfar, Atta; Kane, Garvan C; Perez-Terzic, Carmen M; Crespo-Diaz, Ruben J; McDonald, Robert J; Wyles, Saranya P; Zlatkovic-Lindor, Jelena; Nelson, Timothy J; Terzic, Andre

    2015-01-01

    Background Cardiac resynchronization therapy using bi-ventricular pacing is proven effective in the management of heart failure (HF) with a wide QRS-complex. In the absence of QRS prolongation, however, device-based resynchronization is reported unsuitable. As an alternative, the present study tests a regenerative cell-based approach in the setting of narrow QRS-complex HF. Methods and Results Progressive cardiac dyssynchrony was provoked in a chronic transgenic model of stress-triggered dilated cardiomyopathy. In contrast to rampant end-stage disease afflicting untreated cohorts, stem cell intervention early in disease, characterized by mechanical dyssynchrony and a narrow QRS-complex, aborted progressive dyssynchronous HF and prevented QRS widening. Stem cell-treated hearts acquired coordinated ventricular contraction and relaxation supporting systolic and diastolic performance. Rescue of contractile dynamics was underpinned by a halted left ventricular dilatation, limited hypertrophy, and reduced fibrosis. Reverse remodeling reflected a restored cardiomyopathic proteome, enforced at systems level through correction of the pathological molecular landscape and nullified adverse cardiac outcomes. Cell therapy of a dyssynchrony-prone cardiomyopathic cohort translated prospectively into improved exercise capacity and prolonged survivorship. Conclusions In narrow QRS HF, a regenerative approach demonstrated functional and structural benefit, introducing the prospect of device-autonomous resynchronization therapy for refractory disease. PMID:25964205

  12. Predictors of Prevention Failure in College Students Participating in Two Indicated Depression Prevention Programs

    Science.gov (United States)

    Blanco, Vanessa; Rohde, Paul; Vázquez, Fernando L.; Otero, Patricia

    2014-01-01

    The purpose of this study was to identify subgroups of university students with the highest likelihood of remaining at elevated levels of depressive symptoms six months following the receipt of a depressive prevention intervention on the basis of known risk factors and participation in one of two depression prevention programs. Data from a randomized controlled trial evaluating depression prevention among 133 college students with elevated depressive symptoms were analyzed. Participants were randomized to a cognitive-behavioral or relaxation training group preventive intervention. Classification tree analysis showed that older age was the strongest risk factor for persistently elevated depression. Additional risk factors were: (1) for younger students, fewer daily pleasant activities; (2) for those with higher level of pleasant activities, higher level of stressful events; and (3) for those with higher level of stressful events, lower assertiveness. Results offer directions for prevention foci, identify specific subgroups of college students to target for depression prevention efforts, and suggest that research aim to help older, non-traditional students or graduating students manage the transition from college to the work force. PMID:24714056

  13. Predictors of prevention failure in college students participating in two indicated depression prevention programs.

    Science.gov (United States)

    Blanco, Vanessa; Rohde, Paul; Vázquez, Fernando L; Otero, Patricia

    2014-04-04

    The purpose of this study was to identify subgroups of university students with the highest likelihood of remaining at elevated levels of depressive symptoms six months following the receipt of a depressive prevention intervention on the basis of known risk factors and participation in one of two depression prevention programs. Data from a randomized controlled trial evaluating depression prevention among 133 college students with elevated depressive symptoms were analyzed. Participants were randomized to a cognitive-behavioral or relaxation training group preventive intervention. Classification tree analysis showed that older age was the strongest risk factor for persistently elevated depression. Additional risk factors were: (1) for younger students, fewer daily pleasant activities; (2) for those with higher level of pleasant activities, higher level of stressful events; and (3) for those with higher level of stressful events, lower assertiveness. Results offer directions for prevention foci, identify specific subgroups of college students to target for depression prevention efforts, and suggest that research aim to help older, non-traditional students or graduating students manage the transition from college to the work force.

  14. Aircraft Loss-of-Control Accident Prevention: Switching Control of the GTM Aircraft with Elevator Jam Failures

    Science.gov (United States)

    Chang, Bor-Chin; Kwatny, Harry G.; Belcastro, Christine; Belcastro, Celeste

    2008-01-01

    Switching control, servomechanism, and H2 control theory are used to provide a practical and easy-to-implement solution for the actuator jam problem. A jammed actuator not only causes a reduction of control authority, but also creates a persistent disturbance with uncertain amplitude. The longitudinal dynamics model of the NASA GTM UAV is employed to demonstrate that a single fixed reconfigured controller design based on the proposed approach is capable of accommodating an elevator jam failure with arbitrary jam position as long as the thrust control has enough control authority. This paper is a first step towards solving a more comprehensive in-flight loss-of-control accident prevention problem that involves multiple actuator failures, structure damages, unanticipated faults, and nonlinear upset regime recovery, etc.

  15. Submarine slope failures due to pipe structure formation.

    Science.gov (United States)

    Elger, Judith; Berndt, Christian; Rüpke, Lars; Krastel, Sebastian; Gross, Felix; Geissler, Wolfram H

    2018-02-19

    There is a strong spatial correlation between submarine slope failures and the occurrence of gas hydrates. This has been attributed to the dynamic nature of gas hydrate systems and the potential reduction of slope stability due to bottom water warming or sea level drop. However, 30 years of research into this process found no solid supporting evidence. Here we present new reflection seismic data from the Arctic Ocean and numerical modelling results supporting a different link between hydrates and slope stability. Hydrates reduce sediment permeability and cause build-up of overpressure at the base of the gas hydrate stability zone. Resulting hydro-fracturing forms pipe structures as pathways for overpressured fluids to migrate upward. Where these pipe structures reach shallow permeable beds, this overpressure transfers laterally and destabilises the slope. This process reconciles the spatial correlation of submarine landslides and gas hydrate, and it is independent of environmental change and water depth.

  16. Margin failures in brittle dome structures: relevance to failure of dental crowns.

    Science.gov (United States)

    Qasim, Tarek; Ford, Chris; Bush, Mark B; Hu, Xiaozhi; Malament, Kenneth A; Lawn, Brian R

    2007-01-01

    Margin cracks in loaded brittle dome structures are investigated. Dome structures consisting of glass shells filled with polymer resin, simulating the essential features of brittle crowns on tooth dentin, provide model test specimens. Disk indenters of diminishing elastic modulus are used to apply axisymmetric loading to the apex of the domes. Previous studies using hard indenters have focused on fractures initiating in the near-contact region of such specimens, including radial cracks at the glass undersurface directly below the contact axis. Here, we focus on fractures initiating at the remote support margins. Margin cracks can become dominant when loading forces are distributed over broad contact areas, as in biting on soft matter, here simulated by balsa wood disks. Cracks preinitiated at the dome edges during the specimen preparation propagate under load around the dome side into segmented, semilunar configurations reminiscent of some all-ceramic crown failures. Finite element analysis is used to determine the basic stress states within the dome structures, and to confirm a shift in maximum tensile stress from the near-contact area to the dome sides with more compliant indenters. 2006 Wiley Periodicals, Inc.

  17. Secondary prevention- an essential component of the comprehensive rehabilitation of patients with heart failure

    Directory of Open Access Journals (Sweden)

    Pop Dana

    2017-12-01

    Full Text Available Heart failure is currently a real public health problem due to the extremely high morbidity and mortality of this disease. In this context, cardiovascular prevention measures should be implemented as early as possible. In addition to classic prevention measures, a number of extremely important specific recommendations should be considered: informing patients about their underlying disease, identifying the cardiovascular and non-cardiovascular factors that have led to cardiac decompensation, reducing daily salt consumption, monitoring body weight, forbidding smoking and recreational substances, conducting a regular exercise program under supervision, and increasing adherence to treatment.

  18. Self-Regulation, Cooperative Learning, and Academic Self-Efficacy: Interactions to Prevent School Failure

    OpenAIRE

    Fernández Río, Francisco Javier; Cecchini Estrada, José Antonio; Méndez Giménez, Antonio; Prieto Saborit, José Antonio

    2017-01-01

    Learning to learn and learning to cooperate are two important goals for individuals. Moreover, self regulation has been identified as fundamental to prevent school failure. The goal of the present study was to assess the interactions between self-regulated learning, cooperative learning and academic self-efficacy in secondary education students experiencing cooperative learning as the main pedagogical approach for at least one school year. 2.513 secondary education students (1.308 males, 1.20...

  19. Failure modes and materials design for biomechanical layer structures

    Science.gov (United States)

    Deng, Yan

    Ceramic materials are finding increasing usage in the area of biomechanical replacements---dental crowns, hip and bone implants, etc.---where strength, wear resistance, biocompatibility, chemical durability and even aesthetics are critical issues. Aesthetic ceramic crowns have been widely used in dentistry to replace damaged or missing teeth. However, the failure rates of ceramic crowns, especially all-ceramic crowns, can be 1%˜6% per year, which is not satisfactory to patients. The materials limitations and underlying fracture mechanisms of these prostheses are not well understood. In this thesis, fundamental fracture and damage mechanisms in model dental bilayer and trilayer structures are studied. Principle failure modes are identified from in situ experimentation and confirmed by fracture mechanics analysis. In bilayer structures of ceramic/polycarbonate (representative of ceramic crown/dentin structure), three major damage sources are identified: (i) top-surface cone cracks or (ii) quasiplasticity, dominating in thick ceramic bilayers; (iii) bottom-surface radial cracks, dominating in thin ceramic bilayers. Critical load P for each damage mode are measured in six dental ceramics: Y-TZP zirconia, glass-infiltrated zirconia and alumina (InCeram), glass-ceramic (Empress II), Porcelain (Mark II and Empress) bonded to polymer substrates, as a function of ceramic thickness d in the range of 100 mum to 10 mm. P is found independent of d for mode (i) and (ii), but has a d 2 relations for mode (iii)---bottom surface radial cracking. In trilayer structures of glass/core-ceramic/polycarbonate (representing veneer porcelain/core/dentin structures), three inner fracture origins are identified: radial cracks from the bottom surface in the (i) first and (ii) second layers; and (iii) quasiplasticity in core-ceramic layer. The role of relative veneer/core thickness, d1/d 2 and materials properties is investigated for three core materials with different modulus (114--270GPa

  20. How change management can prevent the failure of information systems implementation among Malaysian government hospitals?

    Science.gov (United States)

    ChePa, Noraziah; Jasin, Noorhayati Md; Bakar, Nur Azzah Abu

    2017-10-01

    Fail to prevent or control challenges of Information System (IS) implementation have led to the failure of its implementation. Successful implementation of IS has been a challenging task to any organization including government hospitals. Government has invested a big amount of money on information system (IS) projects to improve service delivery in healthcare. However, several of them failed to be implemented successfully due to several factors. This article proposes a prevention model which incorporated Change Management (CM) concepts to avoid the failure of IS implementation, hence ensuring the success of it. Challenges of IS implementation in government hospitals have been discovered. Extensive literature review and deep interview approaches were employed to discover these challenges. A prevention model has been designed to cater the challenges. The model caters three main phases of implementation; pre-implementation, during implementation, and post-implementation by adopting CM practices of Lewin's, Kotter's and Prosci's CM model. Six elements of CM comprising thirteen sub-elements adopted from the three CM models have been used to handle CFFs of Human and Support issues; guiding team, resistance avoidance, IS adoption, enforcement, monitoring, and IS sustainability. Successful practice of the proposed mapping is expected to prevent CFFs to occur, hence ensuring a successful implementation of IS in the hospitals. The proposed model has been presented and successfully evaluated by the domain experts from the selected hospitals. The proposed model is believed to be beneficial for top management, IT practitioners and medical practitioners in preventing IS implementation failure among government hospitals towards ensuring the success implementation.

  1. Intelligent failure-proof control system for structural vibration

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Kazuo [Keio Univ., Yokohama (Japan). Faculty of Science and Technology; Oba, Takahiro [Keio Univ., Tokyo (Japan)

    2000-11-01

    With progress of technology in recent years, gigantism and complication such as high-rise buildings, nuclear reactors and so on have brought about new problems. Particularly, the safety and the reliability for damages in abnormal situations have become more important. Intelligent control systems which can judge whether the situation is normal or abnormal at real time and cope with these situations suitably are demanded. In this study, Cubic Neural Network (CNN) is adopted, which consists of the controllers possessing cubically some levels of information abstracting. In addition to the usual quantitative control, the qualitative control is used for the abnormal situations. And, by selecting a suitable controller, CNN can cope with the abnormal situation. In order to confirm the effectiveness of this system, the structural vibration control problems with sensory failure and elasto-plastic response are dealt with. As a result of simulations, it was demonstrated that CNN can cope with unexpected abnormal situations which are not considered in learning. (author)

  2. Intelligent failure-proof control system for structural vibration

    International Nuclear Information System (INIS)

    Yoshida, Kazuo

    2000-01-01

    With progress of technology in recent years, gigantism and complication such as high-rise buildings, nuclear reactors and so on have brought about new problems. Particularly, the safety and the reliability for damages in abnormal situations have become more important. Intelligent control systems which can judge whether the situation is normal or abnormal at real time and cope with these situations suitably are demanded. In this study, Cubic Neural Network (CNN) is adopted, which consists of the controllers possessing cubically some levels of information abstracting. In addition to the usual quantitative control, the qualitative control is used for the abnormal situations. And, by selecting a suitable controller, CNN can cope with the abnormal situation. In order to confirm the effectiveness of this system, the structural vibration control problems with sensory failure and elasto-plastic response are dealt with. As a result of simulations, it was demonstrated that CNN can cope with unexpected abnormal situations which are not considered in learning. (author)

  3. Antimetabolites in cataract surgery to prevent failure of a previous trabeculectomy.

    Science.gov (United States)

    Thomas, Roger E; Crichton, Andrew; Thomas, Bennett C

    2014-07-28

    Patients having cataract surgery have often earlier undergone a trabeculectomy for glaucoma. However, cataract surgery may be associated with failure of the previous glaucoma surgery and antimetabolites may be used with cataract surgery to prevent such failure. There is no systematic review on whether antimetabolites with cataract surgery prevent failure of a previous trabeculectomy. To assess the effects of antimetabolites with cataract surgery on functioning of a previous trabeculectomy. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 5), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2014), EMBASE (January 1980 to June 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to June 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 10 June 2014. We also searched the Science Citation Index database (July 2013) and reference lists of potentially relevant studies. Randomised controlled trials (RCTs) of antimetabolites with cataract surgery in people with a functioning trabeculectomy. Two review authors independently reviewed the titles and abstracts from the electronic searches. Two review authors independently assessed relevant full-text articles and entered data. We identified no RCTs to test the effectiveness of antimetabolites with cataract surgery in individuals with the intention of preventing failure of a previous trabeculectomy. There are no RCTs of antimetabolites with cataract surgery in people with a functioning trabeculectomy. Appropriately powered RCTs

  4. Single-stage Kanban system with deterioration failures and condition-based preventive maintenance

    International Nuclear Information System (INIS)

    Xanthopoulos, A.S.; Koulouriotis, D.E.; Botsaris, P.N.

    2015-01-01

    Despite the fact that the fields of pull type production control policies and condition-based preventive maintenance have much in common contextually, they have evolved independently up to now. In this investigation, an attempt is made to bridge the gap between these two branches of knowledge by introducing the single-stage Kanban system with deterioration failures and condition-based preventive maintenance. The formalism of continuous time Markov chains is used to model the system and expressions for eight performance metrics are derived. Two important, from a managerial perspective, constrained optimization problems for the proposed model are defined where the objective is the simultaneous optimization of the Kanban policy, the preventive maintenance policy and the inspection schedule under conflicting performance criteria. Multiple instances of each optimization problem are solved by means of the augmented Lagrangian genetic algorithm. The results from the optimization trials coupled by the results from extensive numerical examples facilitate the thorough investigation of the system’s behaviour. - Highlights: • Kanban system with deterioration failures and preventive maintenance is introduced. • The system is modeled as a continuous time Markov chain. • Expressions for eight performance metrics are derived. • The behavior of the system is studied through numerical examples. • Optimization results for selected performance metrics are presented

  5. Sodium Channel β2 Subunits Prevent Action Potential Propagation Failures at Axonal Branch Points.

    Science.gov (United States)

    Cho, In Ha; Panzera, Lauren C; Chin, Morven; Hoppa, Michael B

    2017-09-27

    Neurotransmitter release depends on voltage-gated Na + channels (Na v s) to propagate an action potential (AP) successfully from the axon hillock to a synaptic terminal. Unmyelinated sections of axon are very diverse structures encompassing branch points and numerous presynaptic terminals with undefined molecular partners of Na + channels. Using optical recordings of Ca 2+ and membrane voltage, we demonstrate here that Na + channel β2 subunits (Na v β2s) are required to prevent AP propagation failures across the axonal arborization of cultured rat hippocampal neurons (mixed male and female). When Na v β2 expression was reduced, we identified two specific phenotypes: (1) membrane excitability and AP-evoked Ca 2+ entry were impaired at synapses and (2) AP propagation was severely compromised with >40% of axonal branches no longer responding to AP-stimulation. We went on to show that a great deal of electrical signaling heterogeneity exists in AP waveforms across the axonal arborization independent of axon morphology. Therefore, Na v β2 is a critical regulator of axonal excitability and synaptic function in unmyelinated axons. SIGNIFICANCE STATEMENT Voltage-gated Ca 2+ channels are fulcrums of neurotransmission that convert electrical inputs into chemical outputs in the form of vesicle fusion at synaptic terminals. However, the role of the electrical signal, the presynaptic action potential (AP), in modulating synaptic transmission is less clear. What is the fidelity of a propagating AP waveform in the axon and what molecules shape it throughout the axonal arborization? Our work identifies several new features of AP propagation in unmyelinated axons: (1) branches of a single axonal arborization have variable AP waveforms independent of morphology, (2) Na + channel β2 subunits modulate AP-evoked Ca 2+ -influx, and (3) β2 subunits maintain successful AP propagation across the axonal arbor. These findings are relevant to understanding the flow of excitation in the

  6. DAST in Flight just after Structural Failure of Right Wing

    Science.gov (United States)

    1980-01-01

    conducting in-flight experiments from a remote ground site. DAST explored the technology required to build wing structures with less than normal stiffness. This was done because stiffness requires structural weight but ensures freedom from flutter-an uncontrolled, divergent oscillation of the structure, driven by aerodynamic forces and resulting in structural failure. The program used refined theoretical tools to predict at what speed flutter would occur. It then designed a high-response control system to counteract the motion and permit a much lighter wing structure. The wing had, in effect, 'electronic stiffness.' Flight research with this concept was extremely hazardous because an error in either the flutter prediction or control system implementation would result in wing structural failure and the loss of the vehicle. Because of this, flight demonstration of a sub-scale vehicle made sense from the standpoint of both safety and cost. The program anticipated structural failure during the course of the flight research. The Firebee II was a supersonic drone selected as the DAST testbed because its wing could be easily replaced, it used only tail-mounted control surfaces, and it was available as surplus from the U. S. Air Force. It was capable of 5-g turns (that is, turns producing acceleration equal to 5 times that of gravity). Langley outfitted a drone with an aeroelastic, supercritical research wing suitable for a Mach 0.98 cruise transport with a predicted flutter speed of Mach 0.95 at an altitude of 25,000 feet. Dryden and Langley, in conjunction with Boeing, designed and fabricated a digital flutter suppression system (FSS). Dryden developed an RPRV (remotely piloted research vehicle) flight control system; integrated the wing, FSS, and vehicle systems; and conducted the flight program. In addition to a digital flight control system and aeroelastic wings, each DAST drone had research equipment mounted in its nose and a mid-air retrieval system in its tail. The drones

  7. A novel role of three dimensional graphene foam to prevent heater failure during boiling.

    Science.gov (United States)

    Ahn, Ho Seon; Kim, Ji Min; Park, Chibeom; Jang, Ji-Wook; Lee, Jae Sung; Kim, Hyungdae; Kaviany, Massoud; Kim, Moo Hwan

    2013-01-01

    We report a novel boiling heat transfer (NBHT) in reduced graphene oxide (RGO) suspended in water (RGO colloid) near critical heat flux (CHF), which is traditionally the dangerous limitation of nucleate boiling heat transfer because of heater failure. When the heat flux reaches the maximum value (CHF) in RGO colloid pool boiling, the wall temperature increases gradually and slowly with an almost constant heat flux, contrary to the rapid wall temperature increase found during water pool boiling. The gained time by NBHT would provide the safer margin of the heat transfer and the amazing impact on the thermal system as the first report of graphene application. In addition, the CHF and boiling heat transfer performance also increase. This novel boiling phenomenon can effectively prevent heater failure because of the role played by the self-assembled three-dimensional foam-like graphene network (SFG).

  8. Report of the NASA Ad Hoc Committee on failure of high strength structural materials

    Science.gov (United States)

    Brown, W. F., Jr. (Editor)

    1972-01-01

    An analysis of structural failures that have occurred in NASA programs was conducted. Reports of 231 examples of structural failure were reviewed. Attempts were made to identify those factors which contributed to the failures, and recommendations were formulated for actions which would minimize their effects on future NASA programs. Two classes of factors were identified: (1) those associated with deficiencies in existing materials and structures technology and (2) those attributable to inadequate documentation or communication of that technology.

  9. HIV reservoirs and immune surveillance evasion cause the failure of structured treatment interruptions: a computational study.

    Directory of Open Access Journals (Sweden)

    Emiliano Mancini

    Full Text Available Continuous antiretroviral therapy is currently the most effective way to treat HIV infection. Unstructured interruptions are quite common due to side effects and toxicity, among others, and cannot be prevented. Several attempts to structure these interruptions failed due to an increased morbidity compared to continuous treatment. The cause of this failure is poorly understood and often attributed to drug resistance. Here we show that structured treatment interruptions would fail regardless of the emergence of drug resistance. Our computational model of the HIV infection dynamics in lymphoid tissue inside lymph nodes, demonstrates that HIV reservoirs and evasion from immune surveillance themselves are sufficient to cause the failure of structured interruptions. We validate our model with data from a clinical trial and show that it is possible to optimize the schedule of interruptions to perform as well as the continuous treatment in the absence of drug resistance. Our methodology enables studying the problem of treatment optimization without having impact on human beings. We anticipate that it is feasible to steer new clinical trials using computational models.

  10. Study on structural failure of RPV with geometric discontinuity under severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Mao, J.F., E-mail: jianfeng-mao@163.com [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China); Zhu, J.W. [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Department of Mechanical and Electrical engineering, Huzhou Vocational & Technical College Huzhou, Zhejiang 313000 (China); Bao, S.Y., E-mail: bsy@zjut.edu.cn [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China); Luo, L.J. [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Gao, Z.L. [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China)

    2016-10-15

    Highlights: • The RPV failure is investigated in depth under severe accident. • The creep and plastic damage are the major contributor to RPV failure. • A elastic core is found at the midpoint of the highly-eroded region. • Weakest location has some ‘accommodating’ quality to prevent ductile tearing. • The internal pressure is critical for the determination of structural failure. - Abstract: A severe accident management strategy known as ‘in-vessel retention (IVR)’ is widely adopted in most of advanced nuclear power plants. The IVR mitigation is assumed to be able to arrest the degraded melting core and maintain the structural integrity of reactor pressure vessel (RPV) within a prescribed period of time. This traditional concept of IVR without consideration of internal pressure effect wasn’t challenged until the occurrence of Fukushima accident on 2011, which showed that the structural behavior had not been appropriately assessed, and a certain pressure (up to 8.0 MPa) still existed inside the RPV. Accordingly, the paper tries to address the related issue on whether lower head (LH) integrity can be maintained, when the LH is subjected to the thermal-mechanical loads created during such a severe accident. Because of the presence of the high temperature melt (∼1300 °C) on the inside of RPV, some local material is melted down to create a unique RPV with geometric discontinuity, while the outside of RPV submerged in cavity water will remain in nucleate boiling (at ∼150 °C). Therefore, the failure mechanisms of RPV can span a wide range of structural behaviors, such as melt-through, creep damage, plastic yielding as well as thermal expansion. Through meticulous investigation, it is found that the RPV failure is mainly caused by creep and plasticity, especially for the inside of highly-eroded region. The elastic core (or layer) is found to exist in the proximity of mid-section of the highly-eroded wall. However, the elastic core is squeezed into

  11. Study on structural failure of RPV with geometric discontinuity under severe accident

    International Nuclear Information System (INIS)

    Mao, J.F.; Zhu, J.W.; Bao, S.Y.; Luo, L.J.; Gao, Z.L.

    2016-01-01

    Highlights: • The RPV failure is investigated in depth under severe accident. • The creep and plastic damage are the major contributor to RPV failure. • A elastic core is found at the midpoint of the highly-eroded region. • Weakest location has some ‘accommodating’ quality to prevent ductile tearing. • The internal pressure is critical for the determination of structural failure. - Abstract: A severe accident management strategy known as ‘in-vessel retention (IVR)’ is widely adopted in most of advanced nuclear power plants. The IVR mitigation is assumed to be able to arrest the degraded melting core and maintain the structural integrity of reactor pressure vessel (RPV) within a prescribed period of time. This traditional concept of IVR without consideration of internal pressure effect wasn’t challenged until the occurrence of Fukushima accident on 2011, which showed that the structural behavior had not been appropriately assessed, and a certain pressure (up to 8.0 MPa) still existed inside the RPV. Accordingly, the paper tries to address the related issue on whether lower head (LH) integrity can be maintained, when the LH is subjected to the thermal-mechanical loads created during such a severe accident. Because of the presence of the high temperature melt (∼1300 °C) on the inside of RPV, some local material is melted down to create a unique RPV with geometric discontinuity, while the outside of RPV submerged in cavity water will remain in nucleate boiling (at ∼150 °C). Therefore, the failure mechanisms of RPV can span a wide range of structural behaviors, such as melt-through, creep damage, plastic yielding as well as thermal expansion. Through meticulous investigation, it is found that the RPV failure is mainly caused by creep and plasticity, especially for the inside of highly-eroded region. The elastic core (or layer) is found to exist in the proximity of mid-section of the highly-eroded wall. However, the elastic core is squeezed into

  12. Can we reduce preventable heart failure readmissions in patients enrolled in a Disease Management Programme?

    LENUS (Irish Health Repository)

    Phelan, D

    2012-02-01

    BACKGROUND: Disease Management Programmes (DMPs) are successful in reducing hospital readmissions in heart failure (HF). However, there remain a number of patients enrolled in a DMP who are readmitted with HF. The primary aim of the study was to determine the proportion of preventable readmissions (PR). The secondary aim was to recognise patient characteristics which would identify certain patients at risk of having a PR. METHODS: A retrospective chart search was performed on patients readmitted over a 1-year period. RESULTS: 38.5% of readmissions were classified as PR. None of these patients made prior contact with the DMP. Admission levels of BNP, potassium, urea and creatinine were significantly lower in the PR group. CONCLUSION: DMP have proven benefits in reducing hospital readmission nonetheless a significant proportion of these readmissions are preventable. Further work is required to prospectively analyse why these patients fail to contact the DMP.

  13. Roof Deformation, Failure Characteristics, and Preventive Techniques of Gob-Side Entry Driving Heading Adjacent to the Advancing Working Face

    Science.gov (United States)

    Bai, Jian-biao; Shen, Wen-long; Guo, Guan-long; Wang, Xiang-yu; Yu, Yang

    2015-11-01

    In mining excavation, the roof bending subsidence of gob-side entry driving heading adjacent to the advancing working face (HAWF) can be considerable. Influenced by the original rock pressure, the front and lateral abutment pressure of the adjacent working face, and the front abutment pressure of the current working face, the support body can easily fail, leading to serious instability of the rock mass surrounding the tunnel. To study the stress state and the deformation failure mechanism of the HAWF roof structure, we use on-site survey data, numerical simulation, and theoretical calculations to fit the spatial distribution law of mining abutment pressure piecewise, and establish a dynamic mechanical model of the roof structure. We then propose a roof failure criterion and examine the roof flexure deformation behavioral pattern. We found that the central part of the roof is the main point that controls the surrounding rock. To prevent the deformation and collapse of the roof and rock surrounding the tunnel, we propose techniques that can be applied to HAWF gob-side entry driving, including setting the coal pillar width, the driving stop and restart timing, and other control concepts.

  14. An Enhanced Preventive Maintenance Optimization Model Based on a Three-Stage Failure Process

    Directory of Open Access Journals (Sweden)

    Ruifeng Yang

    2015-01-01

    Full Text Available Nuclear power plants are highly complex systems and the issues related to their safety are of primary importance. Probabilistic safety assessment is regarded as the most widespread methodology for studying the safety of nuclear power plants. As maintenance is one of the most important factors for affecting the reliability and safety, an enhanced preventive maintenance optimization model based on a three-stage failure process is proposed. Preventive maintenance is still a dominant maintenance policy due to its easy implementation. In order to correspond to the three-color scheme commonly used in practice, the lifetime of system before failure is divided into three stages, namely, normal, minor defective, and severe defective stages. When the minor defective stage is identified, two measures are considered for comparison: one is that halving the inspection interval only when the minor defective stage is identified at the first time; the other one is that if only identifying the minor defective stage, the subsequent inspection interval is halved. Maintenance is implemented immediately once the severe defective stage is identified. Minimizing the expected cost per unit time is our objective function to optimize the inspection interval. Finally, a numerical example is presented to illustrate the effectiveness of the proposed models.

  15. Method for preventing micromechanical structures from adhering to another object

    Science.gov (United States)

    Smith, J.H.; Ricco, A.J.

    1998-06-16

    A method for preventing micromechanical structures from adhering to another object includes the step of immersing a micromechanical structure and its associated substrate in a chemical species that does not stick to itself. The method can be employed during the manufacture of micromechanical structures to prevent micromechanical parts from sticking or adhering to one another and their associated substrate surface. 3 figs.

  16. Bioinspired, dynamic, structured surfaces for biofilm prevention

    Science.gov (United States)

    Epstein, Alexander K.

    Bacteria primarily exist in robust, surface-associated communities known as biofilms, ubiquitous in both natural and anthropogenic environments. Mature biofilms resist a wide range of biocidal treatments and pose persistent pathogenic threats. Treatment of adherent biofilm is difficult, costly, and, in medical systems such as catheters, frequently impossible. Adding to the challenge, we have discovered that biofilm can be both impenetrable to vapors and extremely nonwetting, repelling even low surface tension commercial antimicrobials. Our study shows multiple contributing factors, including biochemical components and multiscale reentrant topography. Reliant on surface chemistry, conventional strategies for preventing biofilm only transiently affect attachment and/or are environmentally toxic. In this work, we look to Nature's antifouling solutions, such as the dynamic spiny skin of the echinoderm, and we develop a versatile surface nanofabrication platform. Our benchtop approach unites soft lithography, electrodeposition, mold deformation, and material selection to enable many degrees of freedom—material, geometric, mechanical, dynamic—that can be programmed starting from a single master structure. The mechanical properties of the bio-inspired nanostructures, verified by AFM, are precisely and rationally tunable. We examine how synthetic dynamic nanostructured surfaces control the attachment of pathogenic biofilms. The parameters governing long-range patterning of bacteria on high-aspect-ratio (HAR) nanoarrays are combinatorially elucidated, and we discover that sufficiently low effective stiffness of these HAR arrays mechanoselectively inhibits ˜40% of Pseudomonas aeruginosa biofilm attachment. Inspired by the active echinoderm skin, we design and fabricate externally actuated dynamic elastomer surfaces with active surface microtopography. We extract from a large parameter space the critical topographic length scales and actuation time scales for achieving

  17. Is age a factor in the success or failure of remote monitoring in heart failure? Telemonitoring and structured telephone support in elderly heart failure patients.

    Science.gov (United States)

    Inglis, Sally C; Conway, Aaron; Cleland, John Gf; Clark, Robyn A

    2015-06-01

    There are few data regarding the effectiveness of remote monitoring for older people with heart failure. We conducted a post-hoc sub-analysis of a previously published large Cochrane systematic review and meta-analysis of relevant randomized controlled trials to determine whether structured telephone support and telemonitoring were effective in this population. A post hoc sub-analysis of a systematic review and meta-analysis that applied the Cochrane methodology was conducted. Meta-analyses of all-cause mortality, all-cause hospitalizations and heart failure-related hospitalizations were performed for studies where the mean or median age of participants was 70 or more years. The mean or median age of participants was 70 or more years in eight of the 16 (n=2659/5613; 47%) structured telephone support studies and four of the 11 (n=894/2710; 33%) telemonitoring studies. Structured telephone support (RR 0.80; 95% CI=0.63-1.00) and telemonitoring (RR 0.56; 95% CI=0.41-0.76) interventions reduced mortality. Structured telephone support interventions reduced heart failure-related hospitalizations (RR 0.81; 95% CI=0.67-0.99). Despite a systematic bias towards recruitment of individuals younger than the epidemiological average into the randomized controlled trials, older people with heart failure did benefit from structured telephone support and telemonitoring. These post-hoc sub-analysis results were similar to overall effects observed in the main meta-analysis. While further research is required to confirm these observational findings, the evidence at hand indicates that discrimination by age alone may be not be appropriate when inviting participation in a remote monitoring service for heart failure. © The European Society of Cardiology 2014.

  18. Failure mode maps of a hierarchical sandwich structure made of self-reinforced PET

    Science.gov (United States)

    Velea, Marian N.; Lache, Simona

    2018-02-01

    In previous published works, poly-ethylene terephthalate fiber reinforced poly-ethylene terephthalate (SrPET) combined with poly-ethylene terephthalate foam material have been used to develop novel core topologies for sandwich structures. In this study, failure mode maps are created for a hierarchical sandwich structure made of the SrPET material and PET foam, based on analytical estimates, under quasi-static out of plane compression loading conditions. It is shown that four dominant collapse modes may occur: local buckling, general buckling, shear buckling and core shear failure. Each failure mode has an associated weight that varies with the structure load carrying capacity. Based on the developed failure mode maps, the geometric parameters of the structure under study can be chosen such as the structure has the minimum possible weight by ensuring that the failure modes occur simultaneously. The analytical results are compared with experimental tests previously published.

  19. Maximizing survival benefit with primary prevention implantable cardioverter-defibrillator therapy in a heart failure population.

    Science.gov (United States)

    Levy, Wayne C; Lee, Kerry L; Hellkamp, Anne S; Poole, Jeanne E; Mozaffarian, Dariush; Linker, David T; Maggioni, Aldo P; Anand, Inder; Poole-Wilson, Philip A; Fishbein, Daniel P; Johnson, George; Anderson, Jill; Mark, Daniel B; Bardy, Gust H

    2009-09-08

    Although implantable cardioverter-defibrillator (ICD) therapy reduces mortality in moderately symptomatic heart failure patients with an ejection fraction benefits of ICD treatment in the primary prevention Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). In the placebo arm, predicted 4-year mortality grouped into 5 equal-sized risk groups varied from 12% to 50% (c statistic=0.71), whereas the proportion of SCD in those same risk groups decreased from 52% to 24% of all deaths. ICD treatment decreased relative risk of SCD by 88% in the lowest-risk group versus 24% in the highest-risk group (P=0.009 for interaction) and decreased relative risk of total mortality by 54% in the lowest-risk group versus no benefit (2%) in the highest-risk group (P=0.014 for interaction). Absolute 4-year mortality reductions were 6.6%, 8.8%, 10.6%, 14.0%, and -4.9% across risk quintiles. In highest-risk patients (predicted annual mortality >20%), no benefit of ICD treatment was seen. Projected over each patient's predicted lifespan, ICD treatment added 6.3, 4.1, 3.0, 1.9, and 0.2 additional years of life in the lowest- to highest-risk groups, respectively. A clinical risk prediction model identified subsets of moderately symptomatic heart failure patients in SCD-HeFT in whom single-lead ICD therapy was of no benefit and other subsets in which benefit was substantial.

  20. Melatonin and Fertoprotective Adjuvants: Prevention against Premature Ovarian Failure during Chemotherapy.

    Science.gov (United States)

    Jang, Hoon; Hong, Kwonho; Choi, Youngsok

    2017-06-07

    Premature ovarian failure is one of the side effects of chemotherapy in pre-menopausal cancer patients. Preservation of fertility has become increasingly important in improving the quality of life of completely recovered cancer patients. Among the possible strategies for preserving fertility such as ovarian tissue cryopreservation, co-treatment with a pharmacological adjuvant is highly effective and poses less of a burden on the human body. Melatonin is generally produced in various tissues and acts as a universally acting antioxidant in cells. Melatonin is now more widely used in various biological processes including treating insomnia and an adjuvant during chemotherapy. In this review, we summarize the information indicating that melatonin may be useful for reducing and preventing premature ovarian failure in chemotherapy-treated female patients. We also mention that many adjuvants other than melatonin are developed and used to inhibit chemotherapy-induced infertility. This information will give us novel insights on the clinical use of melatonin and other agents as fertoprotective adjuvants for female cancer patients.

  1. Early diagnosis of the urofacial syndrome is essential to prevent irreversible renal failure

    Directory of Open Access Journals (Sweden)

    Francisco A. Nicanor

    2005-10-01

    Full Text Available INTRODUCTION: The urofacial or Ochoa syndrome is a rare disease characterized by the presence of functional obstructive uropathy associated with peculiar facial features when patients attempt to smile or laugh. Unfortunately, many of these patients remain without proper diagnosis or adequate treatment due to lack of recognition of the disease. This can ultimately result in upper tract deterioration and eventual renal failure. We present our experience with this rare syndrome. MATERIALS AND METHODS: We identified 3 patients who presented initially with acute renal failure, urinary tract infection (UTI and severe dysfunctional elimination. All patients were thoroughly evaluated, including screening for spinal cord anomalies, and were subsequently diagnosed with urofacial syndrome. RESULTS: At the outset, the two older patients (aged 4 and 9 years presented with the typical facial features when attempting to smile or laugh. One patient in the newborn period presented with urinary and fecal retention and septicemia and, to our knowledge, represents the youngest case of urofacial syndrome reported so far. All patients were evaluated with ultrasonography, renal scan, voiding cystourethrogram (VCUG and urodynamics. Findings included hydronephrosis and a thick-walled, trabeculated bladder with poor compliance and detrusor hypereflexia respectively in each patient. All were subsequently treated with clean intermittent catheterization (CIC, antibiotic prophylaxis and anticholinergic therapy. One patient required appendicovesicostomy for CIC due to discomfort secondary to a sensate urethra. CONCLUSIONS: Our series demonstrates that early recognition of this rare syndrome is necessary to adequately treat and prevent upper tract deterioration in these unique individuals. Although the urofacial is difficult to diagnose in infants, cognizance must be maintained in order to prevent severe subsequent sequalae.

  2. Embedded structures in flood defenses : Effects on safety and failures

    NARCIS (Netherlands)

    Aguilar Lopez, J.P.; Kothuis, Baukje; Kok, Matthijs

    2017-01-01

    Flood defenses are exposed to deterioration processes that compromise their stability. These processes are called ‘failure mechanisms’ and they are mostly triggered and/or exacerbated by the hydraulic loads generated during extreme high water events, which are

  3. How simulation of failure risk can improve structural reliability - application to pressurized components and pipes

    OpenAIRE

    Cioclov, Dimitru Dragos

    2013-01-01

    Probabilistic methods for failure risk assessment are introduced, with reference to load carrying structures, such as pressure vessels (PV) and components of pipes systems. The definition of the failure risk associated with structural integrity is made in the context of the general approach to structural reliability. Sources of risk are summarily outlined with emphasis on variability and uncertainties (V&U) which might be encountered in the analysis. To highlight the problem, in its practical...

  4. New Therapeutic Approaches to Prevent or Delay Beta-Cell Failure in Diabetes

    Directory of Open Access Journals (Sweden)

    Ionica Floriana Elvira

    2015-09-01

    Full Text Available Background and aims: The most recent estimates of International Diabetes Federation indicate that 382 million people have diabetes, and the incidence of this disease is increasing. While in type 1 diabetes mellitus (T1DM beta-cell death is autoimmunemediated, type 2 diabetes mellitus (T2DM results from an interaction between genetic and environmental factors that impair beta-cell function and insulin action. Many people with T2DM remain unaware of their illness for a long time because symptoms may take years to appear or be recognized, while the body is affected by excess blood glucose. These patients are often diagnosed only when diabetes complications have already developed. The aim of this article was to perform a review based on literature data on therapeutic modalities to prevent/delay beta cell function decline. Material and Methods: We searched MEDLINE from 2000 to the present to identify the therapeutic approaches to prevent or delay beta-cell failure in patients with T2DM. Results and conclusions: Several common polymorphisms in genes linked to monogenic forms of diabetes appear to influence the response to T2DM pharmacotherapy. Recent studies report the role of the G protein coupled receptor 40 (GPR40, also known as Free Fatty Acids Receptor 1 (FFAR1 in the regulation of beta-cell function- CNX-011-67 (a GPR40 agonist has the potential to provide good and durable glycemic control in T2DM patients.

  5. Intellectual structure of the research in entrepreneurial failure

    Directory of Open Access Journals (Sweden)

    Juan Carlos Díaz Cásero

    2014-07-01

    Full Text Available Inside the discipline of “entrepreneurship”, we intend to approach the state of the art research in the field of “failure entrepreneurship” through analysis of documents dating. Therefore, in this article, in addition to traditional qualitative methods, we use quantitative, bibliometric and social network analysis methods. With them we aim to identify the most cited studies to delineate the key authors and theories that form the intellectual framework of the field of entrepreneurship failure, so that we can describe the relationships among the documents that have a greater impact for the construction of the knowledgebase, identifying critical research issues in the area. The analysis revealed the important boom that this field of “failure” is having within the discipline of “entrepreneurship” and the speed that the studies about it are increasing

  6. Optimisation of Structural Systems by Appropriately Assigning Probabilities of Failure : Application to Rubble Mound Breakwaters

    NARCIS (Netherlands)

    Viet, N.D.; Verhagen, H.J.; Van Gelder, P.H.A.J.M.; Vrijling, J.K.

    2008-01-01

    An appropriate assignment of probabilities of failure to subsystems and components in a structural system can bring a minimum of costs and risk. In this paper, a method for economic optimisation of rubble mound breakwaters using pre-assigned probabilities of failure is presented. Application to a

  7. Endochronic theory for inelasticity and failure analysis of concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Bazant, Z.P.; Bhat, P.D.; Shieh, C.L.

    1976-12-01

    A gradual accumulation of inelastic strain can be most conveniently described in terms of the so-called intrinsic time, whose increment depends on the time increment as well as the strain increments. This approach, which gives a particularly simple description of irreversibility of strain at unloading and cyclic loading, was previously developed for metals and is extended herein to concrete by introducing the hydrostatic pressure sensitivity of inelastic strain, the inelastic dilatancy produced by deviator strains, and the strain-softening tendency at high stress. Failure envelopes are obtained as a collection of the peaks of stress-strain diagrams. By comparison with experimental data from the literature, it is demonstrated that the proposed model predicts quite closely: stress-strain diagrams for concretes of different strength; uniaxial, biaxial and triaxial stress-strain diagrams and failure envelopes; failure envelopes for combined torsion and compression, lateral strains and volume expansion in uniaxial and biaxial tests; the behavior of spirally confined concrete; hysteresis loops or repeated high compression; cyclic creep up to 10/sup 6/ cycles; the strain rate effect; the decrease of long time strength; and the increase of short-time strength due to low stress creep.

  8. Endochronic theory for inelasticity and failure analysis of concrete structures

    International Nuclear Information System (INIS)

    Bazant, Z.P.; Bhat, P.D.; Shieh, C.L.

    1976-12-01

    A gradual accumulation of inelastic strain can be most conveniently described in terms of the so-called intrinsic time, whose increment depends on the time increment as well as the strain increments. This approach, which gives a particularly simple description of irreversibility of strain at unloading and cyclic loading, was previously developed for metals and is extended herein to concrete by introducing the hydrostatic pressure sensitivity of inelastic strain, the inelastic dilatancy produced by deviator strains, and the strain-softening tendency at high stress. Failure envelopes are obtained as a collection of the peaks of stress-strain diagrams. By comparison with experimental data from the literature, it is demonstrated that the proposed model predicts quite closely: stress-strain diagrams for concretes of different strength; uniaxial, biaxial and triaxial stress-strain diagrams and failure envelopes; failure envelopes for combined torsion and compression, lateral strains and volume expansion in uniaxial and biaxial tests; the behavior of spirally confined concrete; hysteresis loops or repeated high compression; cyclic creep up to 10 6 cycles; the strain rate effect; the decrease of long time strength; and the increase of short-time strength due to low stress creep

  9. Evaluation of a cavity flooding strategy for the prevention of reactor vessel failure in a severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Park, Rae Joon; Je, Moo Sung; Park, Chang Kyoo [Korea Atomic Energy Research Institute, TaeJon (Korea, Republic of)

    1994-10-01

    As a part of the evaluation of accident management strategies for severe accident prevention or mitigation in a station blackout scenario for YGN 3 and 4, an external vessel cooling strategy for the prevention of reactor vessel failure has been estimated using the MAAP4 computer code. The sensitivity studies have been performed such as actuating timings and the number of spray pumps used. To explore external vessel cooling strategies, containment spray pumps were actuated by varying time spanning core uncovery, core melting and relocation of molten core material. It was shown that flooding of the reactor cavity using the containment spray system may prevent reactor vessel failure but may not prevent the failure of the relocation of molten core material during the station blackout sequence of YGN 3 and 4. Reactor vessel failure can be prevented by external vessel cooling using condensed water from the operation of two containment spray pumps at the time of core melting and using water from the operation of one containment spray pumps at the time of core melting and using water from the operation of one containment spray pump at the time of core uncovery. (Author) 46 refs., 26 figs., 5 tabs.

  10. Embodied Revelation: A Classic Grounded Theory of Heart Failure Patient Decision Making Surrounding Primary Prevention Implantable Cardioverter Defibrillator Therapy

    OpenAIRE

    Vera Barton-Caro Ph.D.,

    2015-01-01

    The purpose of this classic grounded theory study was to explain the complex decision making process of heart failure (HF) patients considering primary prevention implantable cardioverter defibrillator (ICD) therapy. Sudden cardiac death (SCD) is the leading cause of death for people with HF as well as the primary cause of death in the United States (US). ICDs represent the standard of care as the only effective therapy for primary prevention of SCD. However, a significant proportion of quali...

  11. Structural-Health Aware Failure-Tolerant Engineered to Respond (SAFER) Additively Manufactured Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Structural degradation and failure can cause malfunctions and long-term problems aboard spacecraft, jeopardizing the crew, especially in deep space missions. On...

  12. Serelaxin treatment promotes adaptive hypertrophy but does not prevent heart failure in experimental peripartum cardiomyopathy.

    Science.gov (United States)

    Nonhoff, Justus; Ricke-Hoch, Melanie; Mueller, Mirco; Stapel, Britta; Pfeffer, Tobias; Kasten, Martina; Scherr, Michaela; von Kaisenberg, Constantin; Bauersachs, Johann; Haghikia, Arash; Hilfiker-Kleiner, Denise

    2017-05-01

    angiogenesis and compensatory hypertrophy in the diseased heart, but the effects are not sufficient to prevent heart failure in an experimental PPCM model. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Cardiology.

  13. Self-Regulation, Cooperative Learning, and Academic Self-Efficacy: Interactions to Prevent School Failure.

    Science.gov (United States)

    Fernandez-Rio, Javier; Cecchini, Jose A; Méndez-Gimenez, Antonio; Mendez-Alonso, David; Prieto, Jose A

    2017-01-01

    Learning to learn and learning to cooperate are two important goals for individuals. Moreover, self regulation has been identified as fundamental to prevent school failure. The goal of the present study was to assess the interactions between self-regulated learning, cooperative learning and academic self-efficacy in secondary education students experiencing cooperative learning as the main pedagogical approach for at least one school year. 2.513 secondary education students (1.308 males, 1.205 females), 12-17 years old ( M = 13.85, SD = 1.29), enrolled in 17 different schools belonging to the National Network of Schools on Cooperative Learning in Spain agreed to participate. They all had experienced this pedagogical approach a minimum of one school year. Participants were asked to complete the cooperative learning questionnaire, the strategies to control the study questionnaire and the global academic self-efficacy questionnaire. Participants were grouped based on their perceptions on cooperative learning and self-regulated learning in their classes. A combination of hierarchical and κ -means cluster analyses was used. Results revealed a four-cluster solution: cluster one included students with low levels of cooperative learning, self-regulated learning and academic self-efficacy, cluster two included students with high levels of cooperative learning, self-regulated learning and academic self-efficacy, cluster three included students with high levels of cooperative learning, low levels of self-regulated learning and intermediate-low levels of academic self-efficacy, and, finally, cluster four included students with high levels of self-regulated learning, low levels of cooperative learning, and intermediate-high levels of academic self-efficacy. Self-regulated learning was found more influential than cooperative learning on students' academic self-efficacy. In cooperative learning contexts students interact through different types of regulations: self, co, and

  14. Self-Regulation, Cooperative Learning, and Academic Self-Efficacy: Interactions to Prevent School Failure

    Science.gov (United States)

    Fernandez-Rio, Javier; Cecchini, Jose A.; Méndez-Gimenez, Antonio; Mendez-Alonso, David; Prieto, Jose A.

    2017-01-01

    Learning to learn and learning to cooperate are two important goals for individuals. Moreover, self regulation has been identified as fundamental to prevent school failure. The goal of the present study was to assess the interactions between self-regulated learning, cooperative learning and academic self-efficacy in secondary education students experiencing cooperative learning as the main pedagogical approach for at least one school year. 2.513 secondary education students (1.308 males, 1.205 females), 12–17 years old (M = 13.85, SD = 1.29), enrolled in 17 different schools belonging to the National Network of Schools on Cooperative Learning in Spain agreed to participate. They all had experienced this pedagogical approach a minimum of one school year. Participants were asked to complete the cooperative learning questionnaire, the strategies to control the study questionnaire and the global academic self-efficacy questionnaire. Participants were grouped based on their perceptions on cooperative learning and self-regulated learning in their classes. A combination of hierarchical and κ-means cluster analyses was used. Results revealed a four-cluster solution: cluster one included students with low levels of cooperative learning, self-regulated learning and academic self-efficacy, cluster two included students with high levels of cooperative learning, self-regulated learning and academic self-efficacy, cluster three included students with high levels of cooperative learning, low levels of self-regulated learning and intermediate-low levels of academic self-efficacy, and, finally, cluster four included students with high levels of self-regulated learning, low levels of cooperative learning, and intermediate-high levels of academic self-efficacy. Self-regulated learning was found more influential than cooperative learning on students’ academic self-efficacy. In cooperative learning contexts students interact through different types of regulations: self, co, and

  15. Exercise training in heart failure: from theory to practice. A consensus document of the Heart Failure Association and the European Association for Cardiovascular Prevention and Rehabilitation.

    Science.gov (United States)

    Piepoli, Massimo F; Conraads, Viviane; Corrà, Ugo; Dickstein, Kenneth; Francis, Darrel P; Jaarsma, Tiny; McMurray, John; Pieske, Burkert; Piotrowicz, Ewa; Schmid, Jean-Paul; Anker, Stefan D; Solal, Alain Cohen; Filippatos, Gerasimos S; Hoes, Arno W; Gielen, Stefan; Giannuzzi, Pantaleo; Ponikowski, Piotr P

    2011-04-01

    The European Society of Cardiology heart failure guidelines firmly recommend regular physical activity and structured exercise training (ET), but this recommendation is still poorly implemented in daily clinical practice outside specialized centres and in the real world of heart failure clinics. In reality, exercise intolerance can be successfully tackled by applying ET. We need to encourage the mindset that breathlessness may be evidence of signalling between the periphery and central haemodynamic performance and regular physical activity may ultimately bring about favourable changes in myocardial function, symptoms, functional capacity, and increased hospitalization-free life span and probably survival. In this position paper, we provide practical advice for the application of exercise in heart failure and how to overcome traditional barriers, based on the current scientific and clinical knowledge supporting the beneficial effect of this intervention.

  16. Future Issues and Approaches to Health Monitoring and Failure Prevention for Oil-Free Gas Turbines

    Science.gov (United States)

    DellaCorte, Christopher

    2004-01-01

    Recent technology advances in foil air bearings, high temperature solid lubricants and computer based modeling has enabled the development of small Oil-Free gas turbines. These turbomachines are currently commercialized as small (<100 kW) microturbine generators and larger machines are being developed. Based upon these successes and the high potential payoffs offered by Oil-Free systems, NASA, industry, and other government entities are anticipating Oil-Free gas turbine propulsion systems to proliferate future markets. Since an Oil-Free engine has no oil system, traditional approaches to health monitoring and diagnostics, such as chip detection, oil analysis, and possibly vibration signature analyses (e.g., ball pass frequency) will be unavailable. As such, new approaches will need to be considered. These could include shaft orbit analyses, foil bearing temperature measurements, embedded wear sensors and start-up/coast down speed analysis. In addition, novel, as yet undeveloped techniques may emerge based upon concurrent developments in MEMS technology. This paper introduces Oil-Free technology, reviews the current state of the art and potential for future turbomachinery applications and discusses possible approaches to health monitoring, diagnostics and failure prevention.

  17. Interrelation of structure and operational states in cascading failure of overloading lines in power grids

    Science.gov (United States)

    Xue, Fei; Bompard, Ettore; Huang, Tao; Jiang, Lin; Lu, Shaofeng; Zhu, Huaiying

    2017-09-01

    As the modern power system is expected to develop to a more intelligent and efficient version, i.e. the smart grid, or to be the central backbone of energy internet for free energy interactions, security concerns related to cascading failures have been raised with consideration of catastrophic results. The researches of topological analysis based on complex networks have made great contributions in revealing structural vulnerabilities of power grids including cascading failure analysis. However, existing literature with inappropriate assumptions in modeling still cannot distinguish the effects between the structure and operational state to give meaningful guidance for system operation. This paper is to reveal the interrelation between network structure and operational states in cascading failure and give quantitative evaluation by integrating both perspectives. For structure analysis, cascading paths will be identified by extended betweenness and quantitatively described by cascading drop and cascading gradient. Furthermore, the operational state for cascading paths will be described by loading level. Then, the risk of cascading failure along a specific cascading path can be quantitatively evaluated considering these two factors. The maximum cascading gradient of all possible cascading paths can be used as an overall metric to evaluate the entire power grid for its features related to cascading failure. The proposed method is tested and verified on IEEE30-bus system and IEEE118-bus system, simulation evidences presented in this paper suggests that the proposed model can identify the structural causes for cascading failure and is promising to give meaningful guidance for the protection of system operation in the future.

  18. Constructing an effective prevention mechanism for MSW lifecycle using failure mode and effects analysis.

    Science.gov (United States)

    Chen, Ying-Chu; Wu, Wen-Fang

    2015-12-01

    Municipal solid waste in Taiwan is a valuable source of renewable energy. Phases of municipal solid waste lifecycle (classification, disposal, storage, collection and transportation) before incineration or landfilled face various potential failures. Applying a proper technique to eliminate or decrease potential failures is desirable and needed. Failure Modes and Effects Analysis to municipal solid waste lifecycle was found in literature. This study utilized the Failure Modes and Effects Analysis as a convenient technique for determining, classifying and analyzing common failures in the municipal solid waste lifecycle. As a result, an appropriate risk scoring of severity, occurrence, and detection of failure modes and computing the Risk Priority Number for identifying the high potential failure modes were made. Nineteen failure modes were identified, and nine of them were ranked as the priority items for improvement. Recommended actions for all failure modes were suggested. Occurrences of failures were remarkably reduced after implementing the procedure for six months. The results of this study have minimized potential failures and brought continuous improvement, thus achieving a better protection of the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Failure rate of no-scalpel vasectomy in prevention of pregnancy in Shiraz, Southern Iran

    Directory of Open Access Journals (Sweden)

    S Shakeri

    2006-07-01

    Full Text Available BACKGROUND: Bilateral vasectomy is the most effective method of male contraception but there are still some reports on its failure. This study was undertaken to determine the failure rate of the no-scalpel vasectomy in Shiraz Vasectomy Center, Southern Iran. METHODS: From 2001 to 2003, 3900 no-scalpel vasectomies were done in Nader Kazemi Health Center. The records were studied for any failure in the method. Presence of any live sperm 6 months after surgery or any report of pregnancy post-vasectomy were considered as vasectomy failure. RESULTS:Among 3900 cases, 2928 patients had a complete follow up file while failure in the method was visible among 109 (3.72% cases. CONCLUSION: The low failure rate of no-scalpel method indicated its high efficacy to control the fertility in males but there is still need of performance by expert surgeons in well organized centers. KEYWORDS: Iran, no-scalpel vasectomy, failure rate.

  20. Advanced composites: Design and application. Proceedings of the meeting of the Mechanical Failures Prevention Group

    Science.gov (United States)

    Shives, T. R.; Willard, W. A.

    1979-01-01

    The design and application of advanced composites is discussed with emphasis on aerospace, aircraft, automotive, marine, and industrial applications. Failure modes in advanced composites are also discussed.

  1. An overview of the crash dynamics failure behavior of metal and composite aircraft structures

    Science.gov (United States)

    Carden, Huey D.; Boitnott, Richard L.; Fasanella, Edwin L.; Jones, Lisa E.

    1991-01-01

    An overview of failure behavior results is presented from some of the crash dynamics research conducted with concepts of aircraft elements and substructure not necessarily designed or optimized for energy absorption or crash loading considerations. Experimental and analytical data are presented that indicate some general trends in the failure behavior of a class of composite structures that includes fuselage panels, individual fuselage sections, fuselage frames, skeleton subfloors with stringers and floor beams without skin covering, and subfloors with skin added to the frame stringer structure. Although the behavior is complex, a strong similarity in the static/dynamic failure behavior among these structures is illustrated through photographs of the experimental results and through analytical data of generic composite structural models.

  2. Behaviour of concrete nuclear containment structures upto ultimate failure with special reference to MAPP-1 containment

    International Nuclear Information System (INIS)

    Appa Rao, T.V.S.R.

    1975-01-01

    Theoretical and experimental methods for investigating the behaviour of concrete secondary containment structures subjected to loads upto their ultimate failure have been discussed in the paper. Need for inelastic nonlinear analysis of containments has been emphasized. Different contitutive models of concrete that can be employed in the nonlinear analysis of concrete structures were briefly reviewed. Based on the experimental results obtained in a 1:12 scale model test conducted at the Structural Engineering Research (Regional) Centre, Madras, behaviour of the MAPP-1 containment to internal pressure loading upto its ultimate failure has been discussed. (author)

  3. Discrete Material and Thickness Optimization of laminated composite structures including failure criteria

    DEFF Research Database (Denmark)

    Lund, Erik

    2017-01-01

    This work extends the Discrete Material and Thickness Optimization approach to structural optimization problems where strength considerations in the form of failure criteria are taken into account for laminated composite structures. It takes offset in the density approaches applied for stress...... constrained topology optimization of single-material problems and develops formulations for multi-material topology optimization problems applied for laminated composite structures. The method can be applied for both stress- and strain-based failure criteria. The large number of local constraints is reduced...

  4. The effect of mesh size on failure for shell structures

    NARCIS (Netherlands)

    Walters, C.L.; Schipperen, J.H.A.

    2012-01-01

    More than any other application, simulation of crash events depends on the precise representation of fracture. At the same time, practical considerations typically force the crash analyst to use shell elements for many types of thin-walled structures, such as cars, aircraft, and ships. For these

  5. Optimisation of Structural Systems by Appropriately Assigning Probabilities of Failure: Application to Rubble Mound Breakwaters

    OpenAIRE

    Viet, N.D.; Verhagen, H.J.; Van Gelder, P.H.A.J.M.; Vrijling, J.K.

    2008-01-01

    An appropriate assignment of probabilities of failure to subsystems and components in a structural system can bring a minimum of costs and risk. In this paper, a method for economic optimisation of rubble mound breakwaters using pre-assigned probabilities of failure is presented. Application to a design case shows that the proposed method is useful in estimating the optimal design variables in a conceptual design.

  6. Failure of fragmented parathyroid gland autotransplantation to prevent permanent hypoparathyroidism after total thyroidectomy.

    Science.gov (United States)

    Lorente-Poch, Leyre; Sancho, Juan; Muñoz, Jose Luis; Gallego-Otaegui, Lander; Martínez-Ruiz, Carlos; Sitges-Serra, Antonio

    2017-03-01

    Parathyroid autotransplantation during total thyroidectomy leads to higher rates of postoperative hypocalcaemia. It has been argued, however, that it prevents permanent hypoparathyroidism. The impact of autografted normal parathyroid gland fragments on long-term parathyroid status has not been assessed properly. To clarify this, the short- and long-term parathyroid function was assessed in patients with three glands remaining in situ after total thyroidectomy, in whom the fourth gland was either autotransplanted (Tx) or accidentally resected (AR). Consecutive patients (n = 669) undergoing first-time total thyroidectomy were prospectively studied recording the number of parathyroid glands remaining in situ: PGRIS =4-(glands autografted + glands in the specimen). The study was focused on the subgroup of 186 patients with three parathyroid glands remaining in situ as a result of either accidental resection (AR, n = 76) or autotransplantation into the sternocleidomastoid muscle (Tx, n = 110). Prevalence of postoperative hypocalcaemia, protracted, and permanent hypoparathyroidism were compared between the two groups. Demographic, disease-related, laboratory, and surgical variables were recorded. All patients were followed for at least 1 year. Both groups were comparable in terms of disease and extent of surgery. Mean postoperative serum calcium was the same (AR: 1.97 ± 0.2 vs Tx: 1.97 ± 0.22 mmol/L). Rates of protracted (AR: 24% vs Tx: 25.5%) and permanent hypoparathyroidism (AR: 5.3% vs Tx: 7.3%) were similar in both groups. The prevalence of parathyroid failure syndromes after total thyroidectomy was similar whether a parathyroid gland was inadvertently excised or autotransplanted. Autotransplantation did not influence the permanent hypoparathyroidism rate.

  7. A critical review of rock slope failure mechanisms: The importance of structural geology

    Science.gov (United States)

    Stead, Doug; Wolter, Andrea

    2015-05-01

    Geological structures such as folds, faults, and discontinuities play a critical role in the stability and behaviour of both natural and engineered rock slopes. Although engineering geologists have long recognised the importance of structural geology in slopes, it remains a significant challenge to integrate structural geological mapping and theory into all stages of engineering projects. We emphasise the importance of structural geology to slope stability assessments, reviewing how structures control slope failure mechanisms, how engineering geologists measure structures and include them in slope stability analyses, and how numerical simulations of slopes incorporate geological structures and processes.

  8. Core Competencies and the Prevention of School Failure and Early School Leaving

    Science.gov (United States)

    Bradshaw, Catherine P.; O'Brennan, Lindsey M.; McNeely, Clea A.

    2008-01-01

    There is an increasing awareness that school failure and early school leaving are processes, rather than discrete events, that often co-occur and can have lasting negative effects on children's development. Most of the literature has focused on risk factors for failure and dropout rather than on the promotion of competencies that can increase…

  9. Beneficial effects of Resveratrol, present in grapes in the prevention and treatment of heart disease and failure

    Directory of Open Access Journals (Sweden)

    Ali Movahed

    2015-04-01

    Full Text Available Resveratrol (3, 5, 4- trihydroxystilbene is one of the natural polyphenolic bioactive compounds synthesized by plants to serve many functions, especially defense against fungal infections, environmental stresses and UV radiation. It is found mainly in grapes, green tea, peanuts and berries. This compound has recently received increased attention in medical research, due to its effects on prevention and treatment of many diseases, including cancer, cardiovascular disease, and metabolic syndrome. Over the past two decades, researchers from all over the world studied the beneficial effects of resveratrol against cardiovascular diseases and heart failure in different animal models. Importantly, the results of these studies have been promising and recently this knowledge has been translated into examining the efficacy of resveratrol in humans with heart failure. Since heart failure continues to be a significant cause of cardiovascular mortality in the developed and also developing countries, and despite different medicines available for the treatment of such common chronic systemic diseases, preventive measures to be necessary to combat the incidence of heart problems. In this review article the protective effects of resveratrol and its mechanisms of action on different metabolic pathways with respect to heart disease and failure will be discussed.

  10. Prevention preferable to treatment: 3 case reports of patients experiencing right-sided heart failure after Ebstein anomaly correction

    Science.gov (United States)

    Luo, Ming; Lin, Jing; Qin, Zhen; Du, Lei

    2017-01-01

    Abstract Rationale: Ebstein anomaly is a common congenital heart disease that may induce severe tricuspid regurgitation and dilation of the “atrialized” portion of the right ventricle. Patients who undergo surgery to correct Ebstein anomaly are at high risk of postoperative right-sided heart failure, yet little is known about what pre-, peri-, or postoperative procedures may help reduce this risk. Patient concerns: Here, we describe 3 cases of adults with Ebstein anomaly who underwent corrective surgery and in whom right-sided heart failure occurred with severe tricuspid regurgitation detected by transesophageal echocardiography. Diagnoses: Ebstein anomaly. Intervention: Various approaches were applied to prevent right heart failure: perioperative control of atrial and ventricle arrhythmia, protection of myocardium, reduction of right-side cardiac workload after cardiopulmonary bypass, and mechanical support for right heart. Outcomes: One of the 3 patients died, another experienced kidney failure despite postoperative support on extracorporeal membrane oxygenation, and the third patient survived without complications. Lessons: Our case series suggests that surgical prognosis can be improved through aggressive preoperative treatment, vasoactive and anti-arrhythmia medications, and comprehensive measures designed to reduce myocardial injury, prevent myocardial edema, and reduce pre- and afterload on the right ventricle. PMID:28072699

  11. Field application of cathodic prevention on reinforced concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Bazzoni, A.; Bazzoni, B.; Lazzari, L. [Cescor srl, Milano (Italy); Bertolini, L.; Pedeferri, P. [Politecnico di Milano (Italy). Dept. di Chimica Fisica Applicata

    1996-11-01

    This paper illustrates the results gained during the first three years of cathodic protection application to Frejus highway viaducts in northern Italy. CP applications deal with corrosion control of chloride contaminated structures (cathodic protection application properly said) and the corrosion prevention of new non-contaminated structures, constructed with incorporated cathodic protection systems (so-called cathodic prevention). Both normal and post-tensioned structures are present: in the latter case the problems connected with the risk of hydrogen embrittlement of the tendons are discussed. The paper illustrates also the computerized system for gathering and monitoring data and the criteria adopted to evaluate and control the cathodic protection and cathodic prevention conditions as well as to avoid overprotection.

  12. Vascular access specialist teams for device insertion and prevention of failure.

    Science.gov (United States)

    Carr, Peter J; Higgins, Niall S; Cooke, Marie L; Mihala, Gabor; Rickard, Claire M

    2018-03-20

    one registered clinical trial in progress. No studies could be included in the analysis or review. We assigned one study as awaiting classification, as it has not been accepted for publication. This systematic review failed to locate relevant published RCTs to support or refute the assertion that vascular access specialist teams are superior to the generalist model. A vascular access specialist team has advanced knowledge with regard to insertion techniques, clinical care, and management of vascular access devices, whereas a generalist model comprises nurses, doctors, or other designated healthcare professionals in the healthcare facility who may have less advanced insertion techniques and who care for vascular access devices amongst other competing clinical tasks. However, this conclusion may change once the one study awaiting classification and one ongoing study are published. There is a need for good-quality RCTs to evaluate the efficacy of a vascular access specialist team approach for vascular access device insertion and care for the prevention of failure.

  13. Introduction to structural failure modes for nuclear power facilities

    International Nuclear Information System (INIS)

    Reed, J.W.; Gurbuz, O.

    1993-01-01

    This introduction provides a background of the evaluation methods for earthquakes larger than design basis. Seismic probabilistic risk assessment (SPRA) and seismic margin assessment (SMA) methods are introduced to the reader. The basic parameters used to define seismic capacity for each method are explained. The objectives of both evaluation methods and how they can be used to evaluate the adequacy of a seismic design are discussed. General issues related to computing seismic capacity are reviewed relative to SPRA and SMA. Four companion papers presented in the journal following this introduction discuss the types of information (i.e., dynamic tests, earthquake experience, and analytical data) that are used to determine the real capacity of structures and equipment in nuclear power plants to resist earthquakes. The motivation for discussing these three types of information is presented as an introduction to these papers that following in this journal edition. The purpose of the present paper is to lay the groundwork and provide motivation for these papers

  14. Causes and prevention of splitting/bursting failure of concrete crossties: a computational study

    Science.gov (United States)

    2017-09-17

    Concrete splitting/bursting is a well-known failure mode of concrete crossties that can compromise the crosstie integrity and raise railroad maintenance and track safety concerns. This paper presents a computational study aimed at better understandin...

  15. Reliability technology principles and practice of failure prevention in electronic systems

    CERN Document Server

    Pascoe, Norman

    2011-01-01

    A unique book that describes the practical processes necessary to achieve failure free equipment performance, for quality and reliability engineers, design, manufacturing process and environmental test engineers. This book studies the essential requirements for successful product life cycle management. It identifies key contributors to failure in product life cycle management and particular emphasis is placed upon the importance of thorough Manufacturing Process Capability reviews for both in-house and outsourced manufacturing strategies. The readers? attention is also drawn to the ma

  16. Oxime and atropine failure to prevent intermediate syndrome development in acute organophosphate poisoning

    Directory of Open Access Journals (Sweden)

    Vučinić Slavica

    2013-01-01

    Full Text Available Introduction. Intermediate syndrome (IMS was described a few decades ago, however, there is still a controversy regarding its exact etiology, risk factors, diagnostic parameters and required therapy. Considering that acute poisonings are treated in different types of medical institutions this serious complication of organophosphate insecticide (OPI poisoning is frequently overlooked. The aim of this paper was to present a case of IMS in organophosphate poisoning, which, we believe, provides additional data on the use of oxime or atropine. Case report. After a well-resolved cholinergic crisis, the patient developed clinical presentation of IMS within the first 72 h from deliberate malathion ingestion. The signs of IMS were weakness of proximal limb muscles and muscles innervated by motor cranial nerves, followed by the weakness of respiratory muscles and serious respiratory insufficiency. Malathion and its active metabolite were confirmed by analytical procedure (liquid chromatography-mass spectrometry. Pralidoxime methylsulphate, adiministered as a continuous infusion until day 8 (total dose 38.4 g, and atropine until the day 10 (total dose 922 mg did not prevent the development of IMS, hence the mechanical ventilation that was stopped after 27 h had to be continued until the day 10. Conclusion. Continuous pralidoxime methylsulphate infusion with atropine did not prevent the development of IMS, most likely due to the delayed treatment and insufficient oxime dose but also because of chemical structure and lipophilicity of ingested OPI. A prolonged intensive care monitoring and respiratory care are the key management for the intermediate syndrome. [Projekat Ministarstva nauke Republike Srbije, br. OI 176018, No. 46009

  17. Inhibition of N-type Ca2+ channels ameliorates an imbalance in cardiac autonomic nerve activity and prevents lethal arrhythmias in mice with heart failure.

    Science.gov (United States)

    Yamada, Yuko; Kinoshita, Hideyuki; Kuwahara, Koichiro; Nakagawa, Yasuaki; Kuwabara, Yoshihiro; Minami, Takeya; Yamada, Chinatsu; Shibata, Junko; Nakao, Kazuhiro; Cho, Kosai; Arai, Yuji; Yasuno, Shinji; Nishikimi, Toshio; Ueshima, Kenji; Kamakura, Shiro; Nishida, Motohiro; Kiyonaka, Shigeki; Mori, Yasuo; Kimura, Takeshi; Kangawa, Kenji; Nakao, Kazuwa

    2014-10-01

    Dysregulation of autonomic nervous system activity can trigger ventricular arrhythmias and sudden death in patients with heart failure. N-type Ca(2+) channels (NCCs) play an important role in sympathetic nervous system activation by regulating the calcium entry that triggers release of neurotransmitters from peripheral sympathetic nerve terminals. We have investigated the ability of NCC blockade to prevent lethal arrhythmias associated with heart failure. We compared the effects of cilnidipine, a dual N- and L-type Ca(2+) channel blocker, with those of nitrendipine, a selective L-type Ca(2+) channel blocker, in transgenic mice expressing a cardiac-specific, dominant-negative form of neuron-restrictive silencer factor (dnNRSF-Tg). In this mouse model of dilated cardiomyopathy leading to sudden arrhythmic death, cardiac structure and function did not significantly differ among the control, cilnidipine, and nitrendipine groups. However, cilnidipine dramatically reduced arrhythmias in dnNRSF-Tg mice, significantly improving their survival rate and correcting the imbalance between cardiac sympathetic and parasympathetic nervous system activity. A β-blocker, bisoprolol, showed similar effects in these mice. Genetic titration of NCCs, achieved by crossing dnNRSF-Tg mice with mice lacking CACNA1B, which encodes the α1 subunit of NCCs, improved the survival rate. With restoration of cardiac autonomic balance, dnNRSF-Tg;CACNA1B(+/-) mice showed fewer malignant arrhythmias than dnNRSF-Tg;CACNA1B(+/+) mice. Both pharmacological blockade of NCCs and their genetic titration improved cardiac autonomic balance and prevented lethal arrhythmias in a mouse model of dilated cardiomyopathy and sudden arrhythmic death. Our findings suggest that NCC blockade is a potentially useful approach to preventing sudden death in patients with heart failure. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

  18. Empagliflozin Prevents Worsening of Cardiac Function in an Experimental Model of Pressure Overload-Induced Heart Failure

    Directory of Open Access Journals (Sweden)

    Nikole J. Byrne, BSc

    2017-08-01

    Full Text Available This study sought to determine whether the sodium/glucose cotransporter 2 (SGLT2 inhibitor empagliflozin improved heart failure (HF outcomes in nondiabetic mice. The EMPA-REG OUTCOME (Empagliflozin, Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients trial demonstrated that empagliflozin markedly prevented HF and cardiovascular death in subjects with diabetes. However, despite ongoing clinical trials in HF patients without type 2 diabetes, there are no objective and translational data to support an effect of SGLT2 inhibitors on cardiac structure and function, particularly in the absence of diabetes and in the setting of established HF. Male C57Bl/6 mice were subjected to either sham or transverse aortic constriction surgery to induce HF. Following surgery, mice that progressed to HF received either vehicle or empagliflozin for 2 weeks. Cardiac function was then assessed in vivo using echocardiography and ex vivo using isolated working hearts. Although vehicle-treated HF mice experienced a progressive worsening of cardiac function over the 2-week treatment period, this decline was blunted in empagliflozin-treated HF mice. Treatment allocation to empagliflozin resulted in an improvement in cardiac systolic function, with no significant changes in cardiac remodeling or diastolic dysfunction. Moreover, isolated hearts from HF mice treated with empagliflozin displayed significantly improved ex vivo cardiac function compared to those in vehicle-treated controls. Empagliflozin treatment of nondiabetic mice with established HF blunts the decline in cardiac function both in vivo and ex vivo, independent of diabetes. These data provide important basic and translational clues to support the evaluation of SGLT2 inhibitors as a treatment strategy in a broad range of patients with established HF.

  19. Endovenous administration of bone-marrow-derived multipotent mesenchymal stromal cells prevents renal failure in diabetic mice.

    Science.gov (United States)

    Ezquer, Fernando; Ezquer, Marcelo; Simon, Valeska; Pardo, Fabian; Yañez, Alejandro; Carpio, Daniel; Conget, Paulette

    2009-11-01

    Twenty-five to 40% of diabetic patients develop diabetic nephropathy, a clinical syndrome that comprises renal failure and increased risk of cardiovascular disease. It represents the major cause of chronic kidney disease and is associated with premature morbimortality of diabetic patients. Multipotent mesenchymal stromal cells (MSC) contribute to the regeneration of several organs, including acutely injured kidney. We sought to evaluate if MSC protect kidney function and structure when endovenously administered to mice with severe diabetes. A month after nonimmunologic diabetes induction by streptozotocin injection, C57BL/6 mice presented hyperglycemia, glycosuria, hypoinsulinemia, massive beta-pancreatic islet destruction, low albuminuria, but not renal histopathologic changes (DM mice). At this stage, one group of animals received the vehicle (untreated) and other group received 2 doses of 0.5 x 10(6) MSC/each (MSC-treated). Untreated DM mice gradually increased urinary albumin excretion and 4 months after diabetes onset, they reached values 15 times higher than normal animals. In contrast, MSC-treated DM mice maintained basal levels of albuminuria. Untreated DM mice had marked glomerular and tubular histopathologic changes (sclerosis, mesangial expansion, tubular dilatation, proteins cylinders, podocytes lost). However, MSC-treated mice showed only slight tubular dilatation. Observed renoprotection was not associated with an improvement in endocrine pancreas function in this animal model, because MSC-treated DM mice remained hyperglycemic and hypoinsulinemic, and maintained few remnant beta-pancreatic islets throughout the study period. To study MSC biodistribution, cells were isolated from isogenic mice that constitutively express GFP (MSC(GFP)) and endovenously administered to DM mice. Although at very low levels, donor cells were found in kidney of DM mice 3 month after transplantation. Presented preclinical results support MSC administration as a cell

  20. Can a structured checklist prevent problems with laparoscopic equipment?

    NARCIS (Netherlands)

    Verdaasdonk, E.G.G.; Stassen, L.P.S.; Hoffmann, W.F.; Van der Elst, M.; Dankelman, J.

    2008-01-01

    Background A high incidence of problems with the technical equipment is known to occur during routine laparoscopic procedures. Use of a structured checklist of preparatory measures could help to prevent these problems. This study aimed to determine the extent to which a checklist reduced the number

  1. Development of an Advanced Digital Reactor Protection System Using Diverse Dual Processors to Prevent Common-Mode Failure

    International Nuclear Information System (INIS)

    Shin, Hyun Kook; Nam, Sang Ku; Sohn, Se Do; Chang, Hoon Seon

    2003-01-01

    The advanced digital reactor protection system (ADRPS) with diverse dual processors has been developed to prevent common-mode failure (CMF). The principle of diversity is applied to both hardware design and software design. For hardware diversity, two different types of CPUs are used for the bistable processor and local coincidence logic (LCL) processor. The Versa Module Eurocard-based single board computers are used for the CPU hardware platforms. The QNX operating system and the VxWorks operating system were selected for software diversity. Functional diversity is also applied to the input and output modules, and to the algorithm in the bistable processors and LCL processors. The characteristics of the newly developed digital protection system are described together with the preventive capability against CMF. Also, system reliability analysis is discussed. The evaluation results show that the ADRPS has a good preventive capability against the CMF and is a highly reliable reactor protection system

  2. Predicting and preventing peripheral intravenous cannula insertion failure in the emergency department: Clinician 'gestalt' wins again.

    Science.gov (United States)

    Rippey, James Cr; Carr, Peter J; Cooke, Marie; Higgins, Niall; Rickard, Claire M

    2016-12-01

    Failed attempts at peripheral i.v. cannula (PIVC) insertion in the ED are common. The psychological, physical and economic impact of these failures is significant. We sought to explore whether clinicians of differing experience levels can predict their own likelihood (clinician 'gestalt') of first-time cannula insertion success on any given patient. Data analyses from a prospective self-reported study assessing risk factors for first-time insertion success in a tertiary adult ED. We constructed and compared two simple theoretical clinical decision algorithms in an attempt to improve first-time PIVC insertion success rates. This best algorithm identified a subgroup of 18% of the total PIVC population at higher risk of failure. This 18% comprised 57% of all PIVC failures, and implementation would result in a relative risk reduction of PIVC failure by 31%. When applied to our sample population, an algorithm relying on clinician gestalt to identify patients at high risk of PIVC failure had the greatest potential impact. These patients would be referred to expert PIVC inserters prior to, rather than after, failed attempts. © 2016 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

  3. Coordinated experimental/analytical program for investigating margins to failure of Category I reinforced concrete structures

    International Nuclear Information System (INIS)

    Endebrock, E.; Dove, R.; Anderson, C.A.

    1981-01-01

    The material presented in this paper deals with a coordinated experimental/analytical program designed to provide information needed for making margins to failure assessments of seismic Category I reinforced concrete structures. The experimental program is emphasized and background information that lead to this particular experimental approach is presented. Analytical tools being developed to supplement the experimental program are discussed. 16 figures

  4. Sex-specific cardiovascular structure and function in heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    Gori, Mauro; Lam, Carolyn S. P.; Gupta, Deepak K.; Santos, Angela B. S.; Cheng, Susan; Shah, Amil M.; Claggett, Brian; Zile, Michael R.; Kraigher-Krainer, Elisabeth; Pieske, Burkert; Voors, Adriaan A.; Packer, Milton; Bransford, Toni; Lefkowitz, Martin; McMurray, John J. V.; Solomon, Scott D.

    Aims Women are more likely to develop heart failure with preserved ejection fraction (HFpEF) than men. We studied the relationship between sex and cardiovascular structure and function in patients with HFpEF. Methods and resultsThe study included 279 participants from the PARAMOUNT study (57% women)

  5. Association between renal function and cardiovascular structure and function in heart failure with preserved ejection fraction

    NARCIS (Netherlands)

    Gori, Mauro; Senni, Michele; Gupta, Deepak K.; Charytan, David M.; Kraigher-Krainer, Elisabeth; Pieske, Burkert; Claggett, Brian; Shah, Amil M.; Santos, Angela B. S.; Zile, Michael R.; Voors, Adriaan A.; McMurray, John J. V.; Packer, Milton; Bransford, Toni; Lefkowitz, Martin; Solomon, Scott D.

    2014-01-01

    Aim Renal dysfunction is a common comorbidity in patients with heart failure and preserved ejection fraction (HFpEF). We sought to determine whether renal dysfunction was associated with measures of cardiovascular structure/function in patients with HFpEF. Methods We studied 217 participants from

  6. Structural equation model testing the situation-specific theory of heart failure self-care.

    Science.gov (United States)

    Vellone, Ercole; Riegel, Barbara; D'Agostino, Fabio; Fida, Roberta; Rocco, Gennaro; Cocchieri, Antonello; Alvaro, Rosaria

    2013-11-01

    To test the situation-specific theory of heart failure self-care with structural equation modelling. Several authors have proposed theories on heart failure self-care, but only the situation-specific theory of heart failure self-care by Riegel and Dickson is focused on the process that patients use to perform self-care. This theory has never been tested with structural equation modelling. A secondary analysis of data from a cross-sectional study. Patients with heart failure were recruited in 21 cardiovascular centres across Italy during 2011. Data were collected with a sociodemographic questionnaire, chart abstraction for clinical data and the Self-Care of Heart Failure Index v.6.2. A sample of 417 participants was enrolled in the study (59% males, mean age 72 years). The following propositions were tested and supported: Symptom monitoring correlates with treatment adherence; symptom monitoring and treatment adherence have a direct, positive relationship with symptom recognition and evaluation that in turn have a direct, positive relationship with treatment implementation; treatment implementation has a direct, positive relationship with treatment evaluation. In addition, the following three relationships were found: Symptom monitoring has a direct, positive relationship with treatment implementation; symptom recognition and evaluation have direct, positive relationships with treatment evaluation and symptom monitoring correlates with treatment evaluation. [Correction added on 9th April 2013, after first online publication: '…symptom monitoring correlates with treatment implementation.' has been corrected to read '…symptom monitoring correlates with treatment evaluation.'] The data support the situation-specific theory of heart failure self-care with the addition of three new relationships that emerged from the analysis. Results of this study lend further support to the use of the situation-specific theory of heart failure self-care in research and practice.

  7. Systematic analysis and prevention of human originated common cause failures in relation to maintenance activities at Finnish nuclear power plants

    International Nuclear Information System (INIS)

    Laakso, K.

    2006-12-01

    The focus in human reliability analysis of nuclear power plants has traditionally been on human performance in disturbance conditions. On the other hand, human maintenance failures and design deficiencies, remained latent in the system, have an impact on the severity of a disturbance, e.g. by disabling safety-related equipment on demand. Especially common cause failures (CCFs) of safety related systems can affect the core damage risk to a significant extent. The topic has been addressed in Finnish studies, where experiences of latent human errors have been searched and analysed systematically from the maintenance history stored in the the power plant information systems of the Loviisa and Olkiluoto NPPs. Both the single and multiple errors (CCFs) were classified in detail and documented as error and event reports. The human CCFs involved human, organisational and technical factors. The review of the analysed single and multiple errors showed that instrumentation and control and electrical equipment are more prone to human error caused failure events than the other maintenance objects. The review of the analysed experience showed that most errors stem from the refuelling and maintenance outage periods. More than half of the multiple errors from the outages remained latent to the power operating periods. The review of the analysed multiple errors showed that difficulties with small plant modifications and planning of maintenance and operability were significant sources of common cause failures. The most dependent human errors originating from small modifications could be reduced by a more tailored planning and coverage of their start-up testing programs. Improvements could also be achieved by identifying better in work planning from the operating experiences those complex or intrusive repair and preventive maintenance work tasks and actions which are prone to errors. Such uncertain cases in important equipment require a more tailored work planning of the installation

  8. Prevention and management of brain edema in patients with acute liver failure

    DEFF Research Database (Denmark)

    Wendon, J.; Larsen, Finn Stolze

    2008-01-01

    1. Intracranial pressure is the pressure exerted by the cranial contents on the dural envelope and consists of the partial pressures of the brain, blood, and cerebrospinal fluid. 2. Severe cases of acute liver failure are frequently complicated by brain edema (due to cytotoxic edema) and an incre......1. Intracranial pressure is the pressure exerted by the cranial contents on the dural envelope and consists of the partial pressures of the brain, blood, and cerebrospinal fluid. 2. Severe cases of acute liver failure are frequently complicated by brain edema (due to cytotoxic edema......) and an increase in cerebral blood flow while the cerebrospinal fluid volume remains constant. 3. The development of intracranial hypertension in patients with acute liver failure may be controlled by manipulation of the position, body temperature, plasma tonicity, arterial carbon dioxide tension, and arterial...

  9. Estimation of probability of failure for damage-tolerant aerospace structures

    Science.gov (United States)

    Halbert, Keith

    The majority of aircraft structures are designed to be damage-tolerant such that safe operation can continue in the presence of minor damage. It is necessary to schedule inspections so that minor damage can be found and repaired. It is generally not possible to perform structural inspections prior to every flight. The scheduling is traditionally accomplished through a deterministic set of methods referred to as Damage Tolerance Analysis (DTA). DTA has proven to produce safe aircraft but does not provide estimates of the probability of failure of future flights or the probability of repair of future inspections. Without these estimates maintenance costs cannot be accurately predicted. Also, estimation of failure probabilities is now a regulatory requirement for some aircraft. The set of methods concerned with the probabilistic formulation of this problem are collectively referred to as Probabilistic Damage Tolerance Analysis (PDTA). The goal of PDTA is to control the failure probability while holding maintenance costs to a reasonable level. This work focuses specifically on PDTA for fatigue cracking of metallic aircraft structures. The growth of a crack (or cracks) must be modeled using all available data and engineering knowledge. The length of a crack can be assessed only indirectly through evidence such as non-destructive inspection results, failures or lack of failures, and the observed severity of usage of the structure. The current set of industry PDTA tools are lacking in several ways: they may in some cases yield poor estimates of failure probabilities, they cannot realistically represent the variety of possible failure and maintenance scenarios, and they do not allow for model updates which incorporate observed evidence. A PDTA modeling methodology must be flexible enough to estimate accurately the failure and repair probabilities under a variety of maintenance scenarios, and be capable of incorporating observed evidence as it becomes available. This

  10. Prevention and management of brain edema in patients with acute liver failure

    DEFF Research Database (Denmark)

    Wendon, J.; Larsen, Finn Stolze

    2008-01-01

    1. Intracranial pressure is the pressure exerted by the cranial contents on the dural envelope and consists of the partial pressures of the brain, blood, and cerebrospinal fluid. 2. Severe cases of acute liver failure are frequently complicated by brain edema (due to cytotoxic edema......) and an increase in cerebral blood flow while the cerebrospinal fluid volume remains constant. 3. The development of intracranial hypertension in patients with acute liver failure may be controlled by manipulation of the position, body temperature, plasma tonicity, arterial carbon dioxide tension, and arterial...

  11. Failure of preventive measures against radon penetration from the ground in a new-built family house - a case study

    International Nuclear Information System (INIS)

    Neznal, M.; Neznal, M.; Jiranek, M.; Fronka, A.

    2006-01-01

    structure in contact with soil, i.e. even under walls. Special attention should be devoted to the sealing of joints and pipe penetrations through the insulation. The high-quality insulation may be replaced by a common damp-proofing if some special conditions are met: the house is built with a cellar under the complete house area; no residential rooms are found in the cellar; all year reliable natural ventilation of the cellar is provided; the cellar entrance from the floors above is provided with an automatic closing door system and with door sealing. The above mentioned approach is considered to be sufficient even in cases when the building site is classified close to the lower limit of the high radon index (the radon concentration in soil does not exceed twice the concentration that separates the medium and high radon index). In all other cases, the radon-proof insulation in all structures in direct contact with soil must be completed with either a a sub-slab ventilation system or an air gap ventilation under the insulation. The sub-slab ventilation system should reduce the radon concentration under the foundation plate, or create negative pressure in subsoil compared to indoor air pressure. It is a system of perforated drainage pipes that are inserted into a gravel layer under the foundation plate. To ensure effective operation of sub-slab ventilation, it is recommended to extract the soil air from the sub-slab region by the vertical exhaust pipes. The ventilation system can operate in two ways: a passive ventilation, i.e. the ventilation system is controlled by temperature and pressure indoor/sub-floor differences, or an active one, using a fan. Because the fan is usually installed on the vertical exhaust pipes, each passive system may be easily transformed into an active one. A failure of preventive protective measures in a new-built family house will be described and analysed in the paper. Detailed measurements of sub-slab parameters, continual monitoring of indoor

  12. HIV prevention for Black women: structural barriers and opportunities.

    Science.gov (United States)

    Newman, Peter A; Williams, Charmaine C; Massaquoi, Notisha; Brown, Marsha; Logie, Carmen

    2008-08-01

    Black women bear a disproportionate burden of HIV/AIDS in North America. The purpose of this investigation was to explore Black Canadian women's perspectives on HIV risk and prevention. Four 90-minute focus groups (n=26) and six key informant interviews were conducted in Toronto with Black women of African and Caribbean descent and low socioeconomic status. Data analysis revealed a number of potent barriers to existing HIV preventive interventions: stigma, cultural disconnections, lack of engagement of Black religious institutions, and multiple intersecting forms of discrimination. Recommended HIV prevention opportunities included the Black church, mainstreaming, health care providers, and ethno-specific agencies. HIV prevention strategies for North American Black women, rather than focusing on HIV and individual risk behaviors, may benefit from a primary focus on social and structural factors (e.g., promoting gender equality, economic opportunity, women-controlled prevention technologies and combating racism in health care) thereby integrating HIV prevention into the larger context of community health and survival.

  13. Primary Prevention of Reading Failure: Effect of Universal Peer Tutoring in the Early Grades

    Science.gov (United States)

    Jones, Giavana; Ostojic, Dragana; Menard, Jessica; Picard, Erin; Miller, Carlin J.

    2017-01-01

    Reading is typically considered a survival skill in our technology- and literacy-bound culture. Individuals who struggle with learning to read are at significantly elevated risk for a number of negative outcomes, including school failure, under- and unemployment, and special education placement. Thus, those who do not learn to read fluently will…

  14. Which antibiotic regimen prevents implant failure or infection after dental implant surgery? A systematic review and meta-analysis.

    Science.gov (United States)

    Rodríguez Sánchez, Fabio; Rodríguez Andrés, Carlos; Arteagoitia, Iciar

    2018-04-01

    To assess which antibiotic regimen prevents dental implant failures or postoperative infections following dental implant placement. Systematic review and meta-analysis. Pubmed, Cochrane, Science Direct, and EMBASE via OVID were searched up to August 2017. Only randomized controlled clinical trials (RCT) using antibiotics were included. Outcome measures were set on dental implant failures or postoperative infection incidence after dental implant surgery. Three reviewers independently undertook risk of bias assessment and data extraction. Stratified meta-analyses of binary data using fixed-effects models were performed using Stata 14.0. The risk ratio (RR) and 95% confidence interval (CI) were estimated. Nine articles were included corresponding to 15 RCTs. All RCTs tested only oral amoxicillin. Implant-failure analysis: overall RR = 0.53 (P = .005, 95% CI: 0.34-0.82) and overall NNT = 55 (95% CI, 33-167). Single-dose oral amoxicillin preoperatively (SDOAP) is beneficial (RR = 0.50, CI: 0.29-0.86. P = .012), when compared to postoperative oral amoxicillin (POA): RR = 0.60, CI: 0.28-1.30. P = .197. Postoperative-infection analysis: overall RR = 0.76 (P = 0.250, 95% CI: 0.47-1.22). Neither SDOAP (RR = 0.82, CI = 0.46-1.45, P = .488) nor POA (RR = 0.64, CI = 0.27-1.51, P = .309) are beneficial. I 2  = 0.0%, chi-squared tests P ≈ 1. Only SDOAP is effective and efficacious at preventing implant failures, but it was not significant for postoperative infections following dental implant surgeries. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  15. A Diet Rich in Unsaturated Fatty Acids Prevents Progression Toward Heart Failure in a Rabbit Model of Pressure and Volume Overload

    NARCIS (Netherlands)

    den Ruijter, Hester M.; Verkerk, Arie O.; Schumacher, Cees A.; Houten, Sander M.; Belterman, Charly N. W.; Baartscheer, Antonius; Brouwer, Ingeborg A.; van Bilsen, Marc; de Roos, Baukje; Coronel, Ruben

    2012-01-01

    Background-During heart failure (HF), cardiac metabolic substrate preference changes from fatty acid (FA) toward glucose oxidation. This change may cause progression toward heart failure. We hypothesize that a diet rich in FAs may prevent this process, and that dietary omega 3-FAs have an added

  16. The Past, Present, and Future of HIV Prevention: Integrating Behavioral, Biomedical, and Structural Intervention Strategies for the Next Generation of HIV Prevention

    Science.gov (United States)

    Rotheram-Borus, Mary Jane; Swendeman, Dallas; Chovnick, Gary

    2010-01-01

    In the past 25 years, the field of HIV prevention research has been transformed repeatedly. Today, effective HIV prevention requires a combination of behavioral, biomedical, and structural intervention strategies. Risk of transmitting or acquiring HIV is reduced by consistent male and female-condom use, reductions in concurrent and/or sequential sexual and needle-sharing partners, male circumcision, and treatment with antiretroviral medications. At least 144 behavioral prevention programs have been found effective in reducing HIV transmission acts; however, scale up of these programs has not occurred outside of the United States. A series of recent failures of HIV-prevention efficacy trials for biomedical innovations such as HIV vaccines, treating herpes simplex 2 and other sexually transmitted infections, and diaphragm and microbicide barriers highlights the need for behavioral strategies to accompany biomedical strategies. This challenges prevention researchers to reconceptualize how cost-effective, useful, realistic, and sustainable prevention programs will be designed, delivered, tested, and diffused. The next generation of HIV prevention science must draw from the successes of existing evidence-based interventions and the expertise of the market sector to integrate preventive innovations and behaviors into everyday routines. PMID:19327028

  17. IDENTIFICATION OF OPTIMAL PARAMETERS OF REINFORCED CONCRETE STRUCTURES WITH ACCOUNT FOR THE PROBABILITY OF FAILURE

    Directory of Open Access Journals (Sweden)

    Filimonova Ekaterina Aleksandrovna

    2012-10-01

    The author suggests splitting the aforementioned parameters into the two groups, namely, natural parameters and value-related parameters that are introduced to assess the costs of development, transportation, construction and operation of a structure, as well as the costs of its potential failure. The author proposes a new improved methodology for the identification of the above parameters that ensures optimal solutions to non-linear objective functions accompanied by non-linear restrictions that are critical to the design of reinforced concrete structures. Any structural failure may be interpreted as the bounce of a random process associated with the surplus bearing capacity into the negative domain. Monte Carlo numerical methods make it possible to assess these bounces into the unacc eptable domain.

  18. American Heart Association's Life's Simple 7: Avoiding Heart Failure and Preserving Cardiac Structure and Function.

    Science.gov (United States)

    Folsom, Aaron R; Shah, Amil M; Lutsey, Pamela L; Roetker, Nicholas S; Alonso, Alvaro; Avery, Christy L; Miedema, Michael D; Konety, Suma; Chang, Patricia P; Solomon, Scott D

    2015-09-01

    Many people may underappreciate the role of lifestyle in avoiding heart failure. We estimated whether greater adherence in middle age to American Heart Association's Life's Simple 7 guidelines—on smoking, body mass, physical activity, diet, cholesterol, blood pressure, and glucose—is associated with lower lifetime risk of heart failure and greater preservation of cardiac structure and function in old age. We studied the population-based Atherosclerosis Risk in Communities Study cohort of 13,462 adults ages 45-64 years in 1987-1989. From the 1987-1989 risk factor measurements, we created a Life's Simple 7 score (range 0-14, giving 2 points for ideal, 1 point for intermediate, and 0 points for poor components). We identified 2218 incident heart failure events using surveillance of hospital discharge and death codes through 2011. In addition, in 4855 participants free of clinical cardiovascular disease in 2011-2013, we performed echocardiography from which we quantified left ventricular hypertrophy and diastolic dysfunction. One in four participants (25.5%) developed heart failure through age 85 years. Yet, this lifetime heart failure risk was 14.4% for those with a middle-age Life's Simple 7 score of 10-14 (optimal), 26.8% for a score of 5-9 (average), and 48.6% for a score of 0-4 (inadequate). Among those with no clinical cardiovascular event, the prevalence of left ventricular hypertrophy in late life was approximately 40% as common, and diastolic dysfunction was approximately 60% as common, among those with an optimal middle-age Life's Simple 7 score, compared with an inadequate score. Greater achievement of American Heart Association's Life's Simple 7 in middle age is associated with a lower lifetime occurrence of heart failure and greater preservation of cardiac structure and function. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. The Volume Limit in Fluid Resuscitation to Prevent Respiratory Failure in Massively Burned Children without Inhalation Injury

    OpenAIRE

    Okabayashi, Kiyoshi; Ohtani, Minako; Yamanoue, Takao; Sera, Akihiko; Wada, Seishi; Inoue, Takeshi; Iwasaki, Yasumasa

    2001-01-01

    We evaluated the accurate fluid requirement to prevent respiratory failure during the postresuscitation period in the resuscitation of massively burned children without inhalation injury. Forty-nine children were treated by similar fluid resuscitation and physiologic support protocols. Using a retrospective chart review, the children were divided into three groups as follows: Group N (no lung injury, n = 33, 41.4 ± 18. 7%TBSA burned), Group M (mild-to-moderate lung injury, n = 11, 73.7 ± 17.1...

  20. Correlates of isoniazid preventive therapy failure in child household contacts with infectious tuberculosis in high burden settings in Nairobi, Kenya - a cohort study.

    Science.gov (United States)

    Okwara, Florence Nafula; Oyore, John Paul; Were, Fred Nabwire; Gwer, Samson

    2017-09-16

    Sub-Saharan Africa continues to document high pediatric tuberculosis (TB) burden, especially among the urban poor. One recommended preventive strategy involves tracking and isoniazid preventive therapy (IPT) for children under 5 years in close contact with infectious TB. However, sub-optimal effectiveness has been documented in diverse settings. We conducted a study to elucidate correlates to IPT strategy failure in children below 5 years in high burden settings. A prospective longitudinal cohort study was done in informal settlings in Nairobi, where children under 5 years in household contact with recently diagnosed smear positive TB adults were enrolled. Consent was sought. Structured questionnaires administered sought information on index case treatment, socio-demographics and TB knowledge. Contacts underwent baseline clinical screening exclude TB and/or pre-existing chronic conditions. Contacts were then put on daily isoniazid for 6 months and monitored for new TB disease, compliance and side effects. Follow-up continued for another 6 months. At baseline, 428 contacts were screened, and 14(3.2%) had evidence of TB disease, hence excluded. Of 414 contacts put on IPT, 368 (88.8%) completed the 1 year follow-up. Operational challenges were reported by 258(70%) households, while 82(22%) reported side effects. Good compliance was documented in 89% (CI:80.2-96.2). By endpoint, 6(1.6%) contacts developed evidence of new TB disease and required definitive anti-tuberculosis therapy. The main factor associated with IPT failure was under-nutrition of contacts (p = 0.023). Under-nutrition was associated with IPT failure for child contacts below 5 years in high burden, resource limited settings. IPT effectiveness could be optimized through nutrition support of contacts.

  1. LOW-MOLECULAR-WEIGHT HEPARIN TREATMENT FAILURE IN PREVENTION OF PROSTHETIC MITRAL VALVE THROMBOSIS

    OpenAIRE

    David Šuran; Vojko Kanič; Tatjana Golob Gulič; Husam Franjo Naji; Robert Lipovec

    2009-01-01

    Background Prosthetic heart valve thrombosis (PHVT) represents a dangerous postoperative complication following prosthetic heart valve replacement. Incidence varies according to different data from 0.5–4 % per year following mitral or aortic valve replacement in spite of adequate oral anticoagulation with coumarins. Case report We are presenting a case of prosthetic mitral valve thrombosis as a result of 6-month lowmolecular-weight heparin (LMWH) (nadroparine) treatment failure. Our pat...

  2. The influence of the crust layer on RPV structural failure under severe accident condition

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Jianfeng, E-mail: jianfeng-mao@163.com [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China); Li, Xiangqing [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Bao, Shiyi [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China); Luo, Lijia [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Gao, Zengliang [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Re-manufacturing, Ministry of Education (China)

    2017-05-15

    Highlights: • The crust layer greatly affects the RPV structural behavior. • The RPV failure is investigated in depth under severe accident. • The creep and plastic damage mainly contribute to RPV failure. • An elastic core in RPV wall is essential for ensuring RPV integrity. • The multiaxial state of stress accelerates the total damage evolution. - Abstract: The so called ‘in-vessel retention (IVR)’ is regarded as a severe accident (SA) mitigation strategy, which is widely used in most of advanced nuclear power plants. The effectiveness of IVR strategy is to employ the external water flooding to cool the reactor pressure vessel (RPV). The RPV integrity has to be maintained within a required period during the IVR period. The degraded melting core is assumed to be arrested in the lower head (LH) to form the melting pool that is bounded by upper, side and lower crusts. Consequently, the existence of the crust layer greatly affects the RPV structural behavior as well as failure process. In order to disclose this influence caused by the crust layer, a detailed investigation is conducted by using numerical simulation on the two RPVs with and without crust layer respectively. Taking the RPV without crust layer as a basis for the comparison, the present study assesses the likelihood and potential failure location, time and mode of the LH under the loadings of the critical heat flux (CHF) and slight internal pressure. Due to the high temperature melt on the inside and nucleate boiling on the outside, the RPV integrity is found to be compromised by melt-through, creep, elasticity, plasticity as well as thermal expansion. Through in-depth investigation, it is found that the creep and plasticity are of vital importance to the final structural failure, and the introduction of crust layer results in a significant change on field parameters in terms of temperature, deformation, stress(strain), triaxiality factor and total damage.

  3. Prevention of shrinkage cracking in tight concrete structures

    International Nuclear Information System (INIS)

    Alvaredo, A.M.; Wittmann, F.H.

    1995-01-01

    It is shown that crack formation and propagation in concrete members subjected to restrained shrinkage can be realistically predicted by means of a comprehensive approach including a diffusion analysis and fracture mechanics considerations. The conditions for stable crack propagation regarding dimensions of the concrete member, degree of restraint to the imposed deformation and material properties are discussed. Guidelines on the prevention of shrinkage cracking of concrete structures are given. (author). 10 refs., 5 figs

  4. Success, Failure, and Unfinished Business of Education, Prevention, Policy, and Intervention Programs on Substance Misuse in Brazilian Sport.

    Science.gov (United States)

    Santos, Azenildo M

    2015-01-01

    The current Brazilian situation is such that it is difficult to obtain a worldwide evaluation of failure in education, intervention, or prevention programs. How fragile Brazil's anti-doping system is, its appropriateness as well as its relevance, with needed policy infrastructures for achieving the selected goals, and how wide the gap is between education and prevention program effectiveness between high-performance athletes and recreational practitioners who just want to look good. An additional concern, and ever present flaw regarding Brazil's "common sportsman" in day-to-day society is their not receiving known and necessary "sports education," enabling the development of an "at-risk" population for self-harm. Reflections on public health policy are noted.

  5. Software verification and validation methodology for advanced digital reactor protection system using diverse dual processors to prevent common mode failure

    International Nuclear Information System (INIS)

    Son, Ki Chang; Shin, Hyun Kook; Lee, Nam Hoon; Baek, Seung Min; Kim, Hang Bae

    2001-01-01

    The Advanced Digital Reactor Protection System (ADRPS) with diverse dual processors is being developed by the National Research Lab of KOPEC for ADRPS development. One of the ADRPS goals is to develop digital Plant Protection System (PPS) free of Common Mode Failure (CMF). To prevent CMF, the principle of diversity is applied to both hardware design and software design. For the hardware diversity, two different types of CPUs are used for Bistable Processor and Local Coincidence Logic Processor. The VME based Single Board Computers (SBC) are used for the CPU hardware platforms. The QNX Operating System (OS) and the VxWorks OS are used for software diversity. Rigorous Software Verification and Validation (V and V) is also required to prevent CMF. In this paper, software V and V methodology for the ADRPS is described to enhance the ADRPS software reliability and to assure high quality of the ADRPS software

  6. Embodied Revelation: A Classic Grounded Theory of Heart Failure Patient Decision Making Surrounding Primary Prevention Implantable Cardioverter Defibrillator Therapy

    Directory of Open Access Journals (Sweden)

    Vera Barton-Caro Ph.D.,

    2015-12-01

    Full Text Available The purpose of this classic grounded theory study was to explain the complex decision making process of heart failure (HF patients considering primary prevention implantable cardioverter defibrillator (ICD therapy. Sudden cardiac death (SCD is the leading cause of death for people with HF as well as the primary cause of death in the United States (US. ICDs represent the standard of care as the only effective therapy for primary prevention of SCD. However, a significant proportion of qualifying HF patients declines this invasive, yet life-saving device. The grounded theory is of Embodied revelation. The threat of SCD for ICD candidates consists of four stages: living in conscious denial, heightening of awareness, sanctioning ICD therapy, and living in new assurance. The first stage ends abruptly with the critical juncture of grasping the threat of SCD. This grounded theory has implications for research, nursing and medical practice, as well as bioethical considerations.

  7. Recent Advances In Structural Vibration And Failure Mode Control In Mainland China: Theory, Experiments And Applications

    International Nuclear Information System (INIS)

    Li Hui; Ou Jinping

    2008-01-01

    A number of researchers have been focused on structural vibration control in the past three decades over the world and fruit achievements have been made. This paper introduces the recent advances in structural vibration control including passive, active and semiactive control in mainland China. Additionally, the co-author extends the structural vibration control to failure mode control. The research on the failure mode control is also involved in this paper. For passive control, this paper introduces full scale tests of buckling-restrained braces conducted to investigate the performance of the dampers and the second-editor of the Code of Seismic Design for Buildings. For active control, this paper introduces the HMD system for wind-induced vibration control of the Guangzhou TV tower. For semiactive control, the smart damping devices, algorithms for semi-active control, design methods and applications of semi-active control for structures are introduced in this paper. The failure mode control for bridges is also introduced

  8. Development of A Tabulated Thermo-Viscoplastic Material Model with Regularized Failure for Dynamic Ductile Failure Prediction of Structures under Impact Loading

    Science.gov (United States)

    Buyuk, Murat

    It is important to understand the dynamic failure behavior of structures subjected to impact loading in order to improve the survivability. Materials under impact are utterly affected by large deformations, high strain-rates, temperature softening and varying stress-states, which finally may lead to failure. It is shown that the impact characteristics are prone to change with several independent factors such as; impact speed, material thickness, and shape and orientation of the impacting object. Validated numerical simulations of impact tests reveal that the failure on ductile metals occur at certain locations of the failure locus that is constructed on a space as a function of all three stress invariants, which indicates that the failure depends profoundly on the state-of-stress. It is shown that existing material models are not always successful enough to cover the whole range of the failure locus and predict the failure. Therefore, it is a common practice to use different sets of material model parameters tuned or calibrated to cover a specific region of the failure loci in an ad hoc manner for practical reasons to match particular test results. Even in that case, specially tuned material properties are not capable of predicting these limited cases if differences in the mesh size and pattern need to be considered. In this dissertation a new, generic, thermo-elastic/viscoplastic material model with regularized failure is introduced. The new material model is implemented into a non-linear, explicit dynamics finite element code, LS-DYNA. A von Mises type isotropic, isochoric plasticity is utilized, where isotropic hardening, strain-rate hardening and temperature softening is considered. The model takes adiabatic heating and softening into account due to the plastic work. The constitutive relation is coupled with a new regularized accumulated failure law that is specifically developed to cover a large extent of the failure locus as a function of state

  9. Apixaban: Effective and Safe in Preventing Thromboembolic Events in Patients with Atrial Fibrillation and Renal Failure.

    Science.gov (United States)

    Cortese, Francesca; Scicchitano, Pietro; Gesualdo, Michele; Ricci, Gabriella; Carbonara, Santa; Franchini, Carlo; Pia Schiavone, Brigida Immacolata; Corbo, Filomena; Ciccone, Marco Matteo

    2017-11-17

    Thromboembolic events, principally stroke, represent one of the leading causes of morbidity and mortality among subjects with atrial fibrillation. Chronic kidney disease determines a further increase of thromboembolic events, bleeding and mortality and complicates the pharmacological management of patients with atrial fibrillation, mainly due to the side effects of antiarrhythmic and anticoagulant drugs with renal excretion. Apixaban is a new oral anticoagulant characterized by good bioavailability and renal elimination accounting for only 25%, showing a safety profile and effectiveness in patients with renal impairment. In this manuscript, we reviewed literature data on the use of apixaban in the management of non-valvular atrial fibrillation in patients with renal failure, in order to clarify an often-debated topic in clinical practice. A PubMed search was performed on the terms atrial fibrillation, apixaban and renal failure with the aim of identifying relevant manuscripts, large randomized clinical trials, meta-analyses, and current guidelines. Literature data show that apixaban could represent an interesting alternative to warfarin and other selective antagonists of coagulation factors in patients with impaired renal function. About the risk of major bleeding, apixaban appears to be safer than warfarin in the presence of any degree of renal failure. Apixaban show to be an effective anticoagulant in patients with atrial fibrillation, even superior to warfarin in reducing the risk of stroke and systemic embolism regardless of the presence of renal insufficiency. Moreover, Food and Drug Administration allows the use of apixaban in patients with end stage renal disease on hemodialysis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. Bibliography of information on mechanics of structural failure (hydrogen embrittlement, protective coatings, composite materials, NDE)

    Science.gov (United States)

    Carpenter, J. L., Jr.

    1976-01-01

    This bibliography is comprised of approximately 1,600 reference citations related to four problem areas in the mechanics of failure in aerospace structures. The bibliography represents a search of the literature published in the period 1962-1976, the effort being largely limited to documents published in the United States. Listings are subdivided into the four problem areas: Hydrogen Embrittlement; Protective Coatings; Composite Materials; and Nondestructive Evaluation. An author index is included.

  11. Ethanol-lock therapy for the prevention of central venous access device infections in pediatric patients with intestinal failure.

    Science.gov (United States)

    Cober, M Petrea; Kovacevich, Debra S; Teitelbaum, Daniel H

    2011-01-01

    Central venous access device (CVAD) infections are a major complication in pediatric patients receiving long-term parenteral nutrition (PN) and are particularly prevalent in patients with intestinal failure. This study evaluated the outcomes of outpatient ethanol-lock therapy (ELT) for the prevention of CVAD infections in children with intestinal failure. In this retrospective analysis, the primary outcome measure was the rate of bloodstream infection (BSI) due to CVAD infections per 1,000 catheter days, and secondary measures included type of organisms cultured and complications of ELT. Over the course of 2 years, 15 patients received outpatient ELT. Sixty-seven percent were male; patients had a mean ± standard deviation age at enrollment of 5.6 ± 6.9 years and body weight of 19.9 ± 15.4 kg. Mean duration of ELT was 263 ± 190 days. Mean BSI rate per 1,000 catheter days significantly decreased from 8.0 before ELT to 1.3 after ELT (P ELT included thrombosis (n = 1), difficulty withdrawing blood from the CVAD, requiring thrombolytic administration (n = 3), and repair of the CVAD for leakage/tear (n = 20). The rate of CVAD repair for leakage/tear with ELT was compared to prior rates per 1,000 catheter days and was found to be elevated after initiation of ELT (6.4 ± 10.0 vs 3.1 ± 5.2; P = .20). No signs and symptoms of ethanol intoxication were observed. ELT for the prevention of CVAD infections in pediatric intestinal failure patients significantly decreased BSI rates and may be used for extended periods of time in an outpatient setting.

  12. Failure Analysis and Prevention for the Air Logistics Center Engineer: CAStLE Course Development Summary

    Science.gov (United States)

    2006-09-01

    job 3.0a 2.5 positive 2.0 1.5 1.0 0.5- 0.0- ALC dU t ien V U. C 0 O.2 C 0 CS 2 u. g 2 0 E 0 ) a cn ee cs o eam br Uf nel -oes t Cot LL (D o u( 0 LL...1992. Witherell, Charles E., Mechanical Failure Avoidance - Strategies & Techniques. McGraw-Hill, New York, 1994. - A3 - USAF Academy Center for...Analysis b. x- ray (radiography) c. ultrasound d. magnetic particle e. liquid penetrant 4. Mechanical Testing (BE JUDICIOUS!) a. tensile b. hardness 5

  13. Integrating Preventive Maintenance Scheduling As Probability Machine Failure And Batch Production Scheduling

    Directory of Open Access Journals (Sweden)

    Zahedi Zahedi

    2016-06-01

    Full Text Available This paper discusses integrated model of batch production scheduling and machine maintenance scheduling. Batch production scheduling uses minimize total actual flow time criteria and machine maintenance scheduling uses the probability of machine failure based on Weibull distribution. The model assumed no nonconforming parts in a planning horizon. The model shows an increase in the number of the batch (length of production run up to a certain limit will minimize the total actual flow time. Meanwhile, an increase in the length of production run will implicate an increase in the number of PM. An example was given to show how the model and algorithm work.

  14. Predictability of steel containment response near failure track 3 - structural integrity, dynamic behavior, and seismic design

    International Nuclear Information System (INIS)

    Costello, J.F.; Ludwigsen, J.S.; Luk, V.K.; Hessheimer, M.F.

    2000-01-01

    The Nuclear Power Engineering Corporation of Japan and the US Nuclear Regulatory Commission Office of Nuclear Regulatory Research, are co-sponsoring and jointly funding a Cooperative Containment Research Program at Sandia National Laboratories, Albuquerque, New Mexico, USA. As a part of this program, a steel containment vessel model and contact structure assembly was tested to failure with over pressurization at Sandia on December 11--12, 1996. The steel containment vessel model was a mixed-scale model (1:10 in geometry and 1:4 in shell thickness) of a steel containment for an improved Mark-II Boiling Water Reactor plant in Japan. The contact structure, which is a thick, bell-shaped steel shell separated at a nominally uniform distance from the model, provides a simplified representation of features of the concrete reactor shield building in the actual plant. The objective of the internal pressurization test was to provide measurement data of the structural response of the model up to its failure in order to validate analytical modeling, to find its pressure capacity, and to observe the failure model and mechanisms

  15. Use of an inactivated vaccine for prevention of parvovirus-induced reproductive failure in gilts.

    Science.gov (United States)

    Brown, T T; Whitacre, M D; Robison, O W

    1987-01-15

    Gilts from dams that had been inoculated with inactivated porcine parvovirus (PPV) vaccine before breeding became seronegative to PPV by 26 weeks of age. Vaccination of these gilts with inactivated PPV vaccine at 32 weeks of age resulted in an antibody response that peaked at about 2 weeks after vaccination, with -log10 mean hemagglutination inhibiting (HI) antibody titers of less than 2. In the first-year group (82 gilts), HI titers gradually decreased, 20% of the gilts being seronegative by 6 to 7 weeks after vaccination and 75% being seronegative by 16 weeks after vaccination. In the second-year group, 93 gilts were infected naturally by a field strain of PPV at about 11 weeks after single vaccination with inactivated PPV. Additionally, in the second year, 20 vaccinated and 6 nonvaccinated gilts were immune-challenged with virulent PPV at 10 to 12 weeks after vaccination. Neither field nor challenge PPV infection of vaccinated pregnant gilts caused reproductive failure, even though some of the gilts became seronegative for PPV before challenge. Our findings suggest that single vaccination of gilts with inactivated PPV vaccine should give adequate protection from PPV-induced reproductive failure, even though serum HI titers decrease to an undetectable level shortly before PPV infection.

  16. Cardiac outcome prevention effectiveness of glucocorticoids in acute decompensated heart failure: COPE-ADHF study.

    Science.gov (United States)

    Liu, Chao; Liu, Kunshen

    2014-04-01

    Newly emerging evidence showed that glucocorticoids could potentiate natriuretic peptides' action by increasing the density of natriuretic peptide receptor A, leading to a potent diuresis and a renal function improvement in patients with acute decompensated heart failure (ADHF). Therefore, glucocorticoid therapy may be used in patients with ADHF. One hundred two patients with ADHF were randomized to receive glucocorticoids or standard treatment. Change from baseline in serum creatinine (SCr) at day 7 and cardiovascular death within 30 days were recorded. The study was terminated early because of slow site initiation and patient enrolment. Glucocorticoid therapy seemed to be well tolerated. There was a remarkable SCr reduction after 7 days treatment. The change from baseline in SCr is -0.14 mg/dL in glucocorticoid group versus -0.02 mg/dL in standard treatment group (P glucocorticoid group with odds ratio of 0.26 (3 deaths in glucocorticoid vs. 10 deaths in standard treatment group, P glucocorticoid therapy persisted during the follow-up. Patient-assessed dyspnea and physician-assessed global clinical status were also improved in glucocorticoid group. Limited data indicate that glucocorticoid therapy may be used safely in patients with ADHF in short term. Glucocorticoid therapy did not cause heart failure deterioration. Further investigations are warranted.

  17. Subcellular structures and function of myocytes impaired during heart failure are restored by cardiac resynchronization therapy.

    Science.gov (United States)

    Sachse, Frank B; Torres, Natalia S; Savio-Galimberti, Eleonora; Aiba, Takeshi; Kass, David A; Tomaselli, Gordon F; Bridge, John H

    2012-02-17

    Cardiac resynchronization therapy (CRT) is an established treatment for patients with chronic heart failure. However, CRT-associated structural and functional remodeling at cellular and subcellular levels is only partly understood. To investigate the effects of CRT on subcellular structures and protein distributions associated with excitation-contraction coupling of ventricular cardiomyocytes. Our studies revealed remodeling of the transverse tubular system (t-system) and the spatial association of ryanodine receptor (RyR) clusters in a canine model of dyssynchronous heart failure (DHF). We did not find this remodeling in a synchronous heart failure model based on atrial tachypacing. Remodeling in DHF ranged from minor alterations in anterior left ventricular myocytes to nearly complete loss of the t-system and dissociation of RyRs from sarcolemmal structures in lateral cells. After CRT, we found a remarkable and almost complete reverse remodeling of these structures despite persistent left ventricular dysfunction. Studies of whole-cell Ca(2+) transients showed that the structural remodeling and restoration were accompanied with remodeling and restoration of Ca(2+) signaling. DHF is associated with regional remodeling of the t-system. Myocytes undergo substantial structural and functional restoration after only 3 weeks of CRT. The finding suggests that t-system status can provide an early marker of the success of this therapy. The results could also guide us to an understanding of the loss and remodeling of proteins associated with the t-system. The steep relationship between free Ca(2+) and contraction suggests that some restoration of Ca(2+) release units will have a disproportionately large effect on contractility.

  18. PREDICTION AND PREVENTION OF LIVER FAILURE AFTER MAJOR LIVER PRIMARY AND METASTATIC TUMORS RESECTION

    Directory of Open Access Journals (Sweden)

    A. D. Kaprin

    2016-01-01

    Full Text Available Abstract Purpose of the study. Improvement of results of treatment in patients with primary and metastatic liver cancer by decreasing the risk of post-resection liver failure on the basis of the evaluation of the functional reserves of the liver.Materials and Methods. The study included two independent samples of patients operated about primary or metastatic lesions of the liver at the Department of abdominal Oncology, P. A. Hertsen MORI. The first group included 53 patients who carried out 13C-breath test metallimovie and dynamic scintigraphy of the liver in the preoperative stage in addition to the standard algorithm of examination. Patients of the 2nd group (n=35 had a standard clinical and laboratory examination, the patients were not performed the preoperative evaluation of the functional reserve of the liver, the incidences of total bilirubin, albumin and prothrombin time did not reveal a reduction of liver function. Post-resection liver failure have been established on the basis of the 50/50 criterion in the evaluation on day 5 after surgery.Results. Analysis of operating characteristics of the functional tests showed the absolute methacin breath test sensitivity (SE≥100%, high specificity (SP≥67% of scintigraphy of the liver and the negative predictive value of outcome (VP≥100% at complex use of two diagnostic methods. The incidence of PROPS in the study group was significantly 2 times higher in the control group –15,1% and 26.8%, respectively (p<0.001.Conclusion. The combination of preoperative dynamic scintigraphy of the liver with carrying out 13C-breath methacin test allows you to conduct a comprehensive evaluation of the liver functional reserve and can significantly improve preoperative evaluation and postoperative results of anatomic resection in patients with primary and metastatic liver lesions.

  19. Preventive detection of incipient failure and improvement of availability of French PWR using acoustic emission

    International Nuclear Information System (INIS)

    Audenard, B.; Marini, J.

    1982-08-01

    Laboratory tests, on site experience gained on PWR during start up test as well as during nominal functioning have given FRAMATOME very great confidence in A.E. techniques for preventive detection of incidents. Loose part and leakage monitoring are already being used on an industrial basis. Crack growth detection and monitoring are still in the investigation phase and various. Research and Development programs are presently being carried out

  20. Friction Stir Weld Failure Mechanisms in Aluminum-Armor Structures Under Ballistic Impact Loading Conditions

    Science.gov (United States)

    Grujicic, M.; Pandurangan, B.; Arakere, A.; Yen, C.-F.; Cheeseman, B. A.

    2013-01-01

    A critical assessment is carried out of the microstructural changes in respect of the associated reductions in material mechanical properties and of the attendant ballistic-impact failure mechanisms in prototypical friction stir welding (FSW) joints found in armor structures made of high-performance aluminum alloys (including solution-strengthened and age-hardenable aluminum alloy grades). It is argued that due to the large width of FSW joints found in thick aluminum-armor weldments, the overall ballistic performance of the armor is controlled by the ballistic limits of its weld zones (e.g., heat-affected zone, the thermomechanically affected zone, the nugget, etc.). Thus, in order to assess the overall ballistic survivability of an armor weldment, one must predict/identify welding-induced changes in the material microstructure and properties, and the operative failure mechanisms in different regions of the weld. Toward this end, a procedure is proposed in the present study which combines the results of the FSW process modeling, basic physical-metallurgy principles concerning microstructure/property relations, and the fracture mechanics concepts related to the key blast/ballistic-impact failure modes. The utility of this procedure is demonstrated using the case of a solid-solution strengthened and cold-worked aluminum alloy armor FSW-weld test structure.

  1. Improving Intervention Decisions to Prevent Genocide: Less Muddle, More Structure

    Directory of Open Access Journals (Sweden)

    Robin Gregory

    2018-03-01

    Full Text Available Decisions to intervene in a foreign country to prevent genocide and mass atrocities are among the most challenging and controversial choices facing national leaders. Drawing on techniques from decision analysis, psychology, and negotiation analysis, we propose a structured approach to these difficult choices that can provide policy makers with additional insight, consistency, efficiency, and defensibility. We propose the use of a values-based framework to clarify the key elements of these complex choices and to provide a consistent structure for comparison of the likely benefits, risks, and tradeoffs associated with alternative intervention strategies. Results from a workshop involving Ambassadors and experienced policy makers provide a first test of this new method for clarifying intervention choices. A decision-aiding framework is shown to improve the clarity and relevance of intervention deliberations, laying the groundwork for a more comprehensive and clearer understanding of the threats and opportunities associated with various intervention options.

  2. The use of failure mode and effects analysis to construct an effective disposal and prevention mechanism for infectious hospital waste

    International Nuclear Information System (INIS)

    Ho, Chao Chung; Liao, Ching-Jong

    2011-01-01

    Highlights: → This study is based on a real case in a regional teaching hospital in Taiwan. → We use Failure mode and effects analysis (FMEA) as the evaluation method. → We successfully identify the risk factors of infectious waste disposal. → We propose plans for the detection of exceptional cases of infectious waste. - Abstract: In recent times, the quality of medical care has been continuously improving in medical institutions wherein patient-centred care has been emphasized. Failure mode and effects analysis (FMEA) has also been promoted as a method of basic risk management and as part of total quality management (TQM) for improving the quality of medical care and preventing mistakes. Therefore, a study was conducted using FMEA to evaluate the potential risk causes in the process of infectious medical waste disposal, devise standard procedures concerning the waste, and propose feasible plans for facilitating the detection of exceptional cases of infectious waste. The analysis revealed the following results regarding medical institutions: (a) FMEA can be used to identify the risk factors of infectious waste disposal. (b) During the infectious waste disposal process, six items were scored over 100 in the assessment of uncontrolled risks: erroneous discarding of infectious waste by patients and their families, erroneous discarding by nursing staff, erroneous discarding by medical staff, cleaning drivers pierced by sharp articles, cleaning staff pierced by sharp articles, and unmarked output units. Therefore, the study concluded that it was necessary to (1) provide education and training about waste classification to the medical staff, patients and their families, nursing staff, and cleaning staff; (2) clarify the signs of caution; and (3) evaluate the failure mode and strengthen the effects.

  3. Painful posterior shoulder instability: Anticipating and preventing failure. A study in 25 patients.

    Science.gov (United States)

    Garret, J; Nourissat, G; Hardy, M B; Antonucci, D; Clavert, P; Mansat, P; Godenèche, A

    2017-12-01

    Painful posterior shoulder instability (PPSI) is the least common of the three clinical patterns of posterior shoulder instability. PPSI is defined as pain combined with anatomical evidence of posterior instability but no instability events. We studied a multicentre cohort of 25 patients with PPSI; 23 were identified retrospectively and had a follow-up of at least 2 years and 2 patients were included prospectively. Most patients engaged in sports. All 25 patients underwent surgery, which usually consisted in arthroscopic capsulo-labral reconstruction. The outcome was excellent in 43% of patients; another 43% had improvements but reported persistent pain. The pain remained unchanged or worsened in the remaining 14% of patients. Causes of failure consisted of a missed diagnosis of shoulder osteoarthritis with posterior subluxation, technical errors, and postoperative complications. The main cause of incomplete improvement with persistent pain was presence of cartilage damage. Outcomes were excellent in patients who were free of cartilage damage, bony abnormalities associated with posterior instability (reverse Hill-Sachs lesion, erosion or fracture of the posterior glenoid), technical errors, and postoperative complications. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Becoming a first-class noticer. How to spot and prevent ethical failures in your organization.

    Science.gov (United States)

    Bazerman, Max H

    2014-01-01

    We'd like to think that no smart, upstanding manager would ever overlook or turn a blind eye to threats or wrongdoing that ultimately imperil his or her business. Yet it happens all the time. We fall prey to obstacles that obscure or drown out important signals that things are amiss. Becoming a "first-class noticer," says Max H. Bazerman, a professor at Harvard Business School, requires conscious effort to fight ambiguity, motivated blindness, conflicts of interest, the slippery slope, and efforts of others to mislead us. As a manager, you can develop your noticing skills by acknowledging responsibility when things go wrong rather than blaming external forces beyond your control. Bazerman also advises taking an outsider's view to challenge the status quo. Given the string of ethical failures of corporations around the world in recent years--from BP to GM to JP Morgan Chase--it's clear that leaders not only need to act more responsibly themselves but also must develop keen noticing skills in their employees and across their organizations.

  5. The Financial Benefits of Various Catastrophic Failure Prevention Strategies in a Wind Farm: Two market studies (UK-Spain)

    Science.gov (United States)

    Yürüşen, N. Y.; Tautz-Weinert, J.; Watson, S. J.; Melero, J. J.

    2017-11-01

    Operation of wind farms is driven by the overall aim of minimising costs while maximising energy sales. However, in certain circumstances investments are required to guarantee safe operation and survival of an asset. In this paper, we discuss the merits of various catastrophic failure prevention strategies in a Spanish wind farm. The wind farm operator was required to replace blades in two phases: temporary and final repair. We analyse the power performance of the turbine in the different states and investigate four scenarios with different timing of temporary and final repair during one year. The financial consequences of the scenarios are compared with a baseline by using a discounted cash flow analysis that considers the wholesale electricity market selling prices and interest rates. A comparison with the UK electricity market is conducted to highlight differences in the rate of return in the two countries.

  6. Optimizing production and imperfect preventive maintenance planning's integration in failure-prone manufacturing systems

    International Nuclear Information System (INIS)

    Aghezzaf, El-Houssaine; Khatab, Abdelhakim; Tam, Phuoc Le

    2016-01-01

    This paper investigates the issue of integrating production and maintenance planning in a failure-prone manufacturing system. It is assumed that the system's operating state is stochastically predictable, in terms of its operating age, and that it can accordingly be preventively maintained during preplanned periods. Preventive maintenance is assumed to be imperfect, that is when performed, it brings the manufacturing system to an operating state that lies between ‘as bad as old’ and ‘as good as new’. Only an overhauling of the system brings it to a ‘as good as new’ operating state again. A practical integrated production and preventive maintenance planning model, that takes into account the system's manufacturing capacity and its operational reliability state, is developed. The model is naturally formulated as a mixed-integer non-linear optimization problem, for which an extended mixed-integer linear reformulation is proposed. This reformulation, while it solves the proposed integrated planning problem to optimality, remains quite demanding in terms of computational time. A fix-and-optimize procedure, that takes advantage of some properties of the original model, is then proposed. The reformulation and the fix-and-optimize procedure are tested on some test instances adapted from those available in the literature. The results show that the proposed fix-and-optimize procedure performs quite well and opens new research direction for future improvements. - Highlights: • Integration of production planning and imperfect preventive maintenance is explored. • Imperfect maintenance is modeled using a fitting age reduction hybrid hazard rate. • A practical approximate optimization model for this integration is proposed. • The resulting naturally MINL optimization model is reformulated and solved as a MILP. • An effective fix-and-optimize procedure is proposed for large instances of this MILP.

  7. Iron-regulatory proteins secure iron availability in cardiomyocytes to prevent heart failure.

    Science.gov (United States)

    Haddad, Saba; Wang, Yong; Galy, Bruno; Korf-Klingebiel, Mortimer; Hirsch, Valentin; Baru, Abdul M; Rostami, Fatemeh; Reboll, Marc R; Heineke, Jörg; Flögel, Ulrich; Groos, Stephanie; Renner, André; Toischer, Karl; Zimmermann, Fabian; Engeli, Stefan; Jordan, Jens; Bauersachs, Johann; Hentze, Matthias W; Wollert, Kai C; Kempf, Tibor

    2017-02-01

    Iron deficiency (ID) is associated with adverse outcomes in heart failure (HF) but the underlying mechanisms are incompletely understood. Intracellular iron availability is secured by two mRNA-binding iron-regulatory proteins (IRPs), IRP1 and IRP2. We generated mice with a cardiomyocyte-targeted deletion of Irp1 and Irp2 to explore the functional implications of ID in the heart independent of systemic ID and anaemia. Iron content in cardiomyocytes was reduced in Irp-targeted mice. The animals were not anaemic and did not show a phenotype under baseline conditions. Irp-targeted mice, however, were unable to increase left ventricular (LV) systolic function in response to an acute dobutamine challenge. After myocardial infarction, Irp-targeted mice developed more severe LV dysfunction with increased HF mortality. Mechanistically, the activity of the iron-sulphur cluster-containing complex I of the mitochondrial electron transport chain was reduced in left ventricles from Irp-targeted mice. As demonstrated by extracellular flux analysis in vitro, mitochondrial respiration was preserved at baseline but failed to increase in response to dobutamine in Irp-targeted cardiomyocytes. As shown by 31P-magnetic resonance spectroscopy in vivo, LV phosphocreatine/ATP ratio declined during dobutamine stress in Irp-targeted mice but remained stable in control mice. Intravenous injection of ferric carboxymaltose replenished cardiac iron stores, restored mitochondrial respiratory capacity and inotropic reserve, and attenuated adverse remodelling after myocardial infarction in Irp-targeted mice but not in control mice. As shown by electrophoretic mobility shift assays, IRP activity was significantly reduced in LV tissue samples from patients with advanced HF and reduced LV tissue iron content. ID in cardiomyocytes impairs mitochondrial respiration and adaptation to acute and chronic increases in workload. Iron supplementation restores cardiac energy reserve and function in iron

  8. Fatigue degradation and failure of rotating composite structures - Materials characterisation and underlying mechanisms

    DEFF Research Database (Denmark)

    Gamstedt, Kristofer; Andersen, Svend Ib Smidt

    2001-01-01

    The present review concerns rotating composite structures, in which fatigue degradation is of key concern for in-service failure. Such applications are for instance rotor blades in wind turbines, helicopter rotor blades, flywheels for energy storage,marine and aeronautical propellers, and rolls...... for paper machines. The purpose is to identify areas where impending efforts should be made to make better use of composite materials in these applications. In order to obtain better design methodologies,which would allow more reliable and slender structures, improved test methods are necessary. Furthermore......, the relation between structural, component and specimen test results should be better understood than what is presently the case. Improvedpredictive methods rely on a better understanding of the underlying damage mechanisms. With mechanism-based models, the component substructure or even the material...

  9. A treatment algorithm for children with lupus nephritis to prevent developing renal failure

    Directory of Open Access Journals (Sweden)

    Nilofar Hajizadeh

    2014-01-01

    Full Text Available Chronic kidney disease is one of the most common complication of systemic lupus erythematosus, which if untreated can lead to the end stage renal disease (ESRD. Early diagnosis and adequate treatment of lupus nephritis (LN is critical to prevent the chronic kidney disease incidence and to reduce the development of ESRD. The treatment of LN has changed significantly over the past decade. In patients with active proliferative LN (Classes III and IV intravenous methylprednisolone 1 g/m2/day for 1 3 days then prednisone 0.5 1.0 mg/kg/day, tapered to <0.5 mg/kg/day after 10 12 weeks of treatment plus mycophenolate mofetile (MMF 1.2 g/m2/day for 6 months followed by maintenance lower doses of MMF 1 2 g/day or azathioprine (AZA 2 mg/kg/day for 3 years have proven to be efficacy and less toxic than cyclophosphamide (CYC therapy. Patients with membranous LN (Class V plus diffuse or local proliferative LN (Class III and Class IV should receive either the standard 6 monthly pulses of CYC (0.5 1 g/m2/month then every 3rd month or to a shorter treatment course consisting of 0.5 g/m2 IV CYC every 2 weeks for six doses (total dose 3 g followed by maintenance therapy with daily AZA (2 mg/kg/day or MMF (0.6 g/m2/day for 3 years. Combination of MMF plus rituximab or MMF plus calcineurin inhibitors may be an effective co therapy for those refractory to induction or maintenance therapies. This report introduces a new treatment algorithm to prevent the development of ESRD in children with LN.

  10. Role of core support material in veneer failure of brittle layer structures.

    Science.gov (United States)

    Hermann, Ilja; Bhowmick, Sanjit; Lawn, Brian R

    2007-07-01

    A study is made of veneer failure by cracking in all-ceramic crown-like layer structures. Model trilayers consisting of a 1 mm thick external glass layer (veneer) joined to a 0.5 mm thick inner stiff and hard ceramic support layer (core) by epoxy bonding or by fusion are fabricated for testing. The resulting bilayers are then glued to a thick compliant polycarbonate slab to simulate a dentin base. The specimens are subjected to cyclic contact (occlusal) loading with spherical indenters in an aqueous environment. Video cameras are used to record the fracture evolution in the transparent glass layer in situ during testing. The dominant failure mode is cone cracking in the glass veneer by traditional outer (Hertzian) cone cracks at higher contact loads and by inner (hydraulically pumped) cone cracks at lower loads. Failure is deemed to occur when one of these cracks reaches the veneer/core interface. The advantages and disadvantages of the alumina and zirconia core materials are discussed in terms of mechanical properties-strength and toughness, as well as stiffness. Consideration is also given to the roles of interface strength and residual thermal expansion mismatch stresses in relation to the different joining methods. Copyright 2006 Wiley Periodicals, Inc.

  11. Semiparametric Bayesian analysis of accelerated failure time models with cluster structures.

    Science.gov (United States)

    Li, Zhaonan; Xu, Xinyi; Shen, Junshan

    2017-11-10

    In this paper, we develop a Bayesian semiparametric accelerated failure time model for survival data with cluster structures. Our model allows distributional heterogeneity across clusters and accommodates their relationships through a density ratio approach. Moreover, a nonparametric mixture of Dirichlet processes prior is placed on the baseline distribution to yield full distributional flexibility. We illustrate through simulations that our model can greatly improve estimation accuracy by effectively pooling information from multiple clusters, while taking into account the heterogeneity in their random error distributions. We also demonstrate the implementation of our method using analysis of Mayo Clinic Trial in Primary Biliary Cirrhosis. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Organizational structure for chronic heart failure and chronic obstructive pulmonary disease.

    Science.gov (United States)

    Rinne, Seppo T; Liu, Chuan-Fen; Wong, Edwin S; Hebert, Paul L; Heidenreich, Paul; Bastian, Lori A; Au, David H

    2016-03-01

    In contrast to chronic heart failure (CHF), measures of quality of care for chronic obstructive pulmonary disease (COPD) are poor. Our objective was to examine differences in organizational structure available to support quality of care for patients with CHF and COPD. We performed 2 nationwide surveys exploring organizational structure for the management of CHF and COPD. We surveyed the chief of medicine and the chief of cardiology and pulmonary medicine at 120 Veterans Affairs facilities in the United States. Analogous questions about organizational structure that enhanced adherence to guideline-based care were compared between CHF and COPD surveys. We found large and notable differences in the organizational structure for disease management, with systematically less attention given to COPD than CHF. These differences were evident in multiple processes of care. Key differences included fewer facilities: having COPD clinics than CHF clinics (12.7% vs 50.8%; P organizational structure existed for COPD than CHF. Lack of organizational structure for COPD likely impedes an organization's abilities to encourage high-quality care and avoid recently implemented hospital readmission penalties. Our results suggest the need to develop a systematic approach for healthcare systems to provide essential organizational structure based on the burden of disease in the population.

  13. Failure Analysis of Pitted Copper Pipes Used in Underground Water and Preventive Measures

    Science.gov (United States)

    Nam, Gi-ho; Lee, Jong-kwon; Kim, Kyung-ja

    2018-03-01

    This study performed an experiment on the causes of pitting corrosion in a copper tubing used for a sprinkler system. Corrosion products of a copper tubing that sustained pitting corrosion were collected and cultured in Culture medium [Luria-Bertani, Brain heart infusion, Tryptic soy broth (TSB), R2A]. Four types of bacteria were found through identification: Micrococcus luteus sp (species)., Staphylococcus sp., Sphingomonas sp., and Bacillus sp. The copper toxicity test was performed for each microorganism. Among the four microorganisms, Micrococcus luteus sp. showed good growth in the environment containing copper ions. On the immersion test, changes in pH and Optical density were measured; On the inductively coupled plasma optical emission spectrometry test, the copper concentration of each culture medium was measured. The surface of each copper sample was observed using a scanning electron microscope. The corrosion potential of a copper sample, after 48 h exposure of the TSB medium containing Micrococcus luteus sp., was measured using a potentiodynamic polarization experiment. The next experiment was conducted to prevent microbial corrosion by suppressing the growth of microorganisms. Six 30 ml TSB culture media with controlled pH value of 4, 5, 6, 7, 8, and 9 through HCl and NaOH were manufactured. Then the microorganisms were cultured in 37 °C 133 rpm, of which the growth status was checked every 24 h for 3 days. It was found that microorganisms did not grow on culture media with the pH value of 6 and lower. The same experiment conducted on culture media controlled with acetic acid, nitric acid, and sulfuric acid, also showed no growth of microorganisms on media with pH value of 6 and lower. Six 5 ml TSB culture media each containing 0.5, 0.25, 0.125, 0.0625, 0.0312%, and 0.0156% NaOCl and NaOBr as germicides were manufactured. 0.01 μl of microorganisms were inoculated on the media and cultured in 37 °C for 48 h. It was found that microorganisms did not

  14. A failure of matrix metalloproteinase inhibition in the prevention of rat intracranial aneurysm formation

    International Nuclear Information System (INIS)

    Kaufmann, T.J.; Kallmes, D.F.; Marx, W.F.

    2006-01-01

    We tested the hypothesis that nonspecific matrix metalloproteinase (MMP) inhibition with doxycycline would decrease the incidence of intracranial aneurysm formation in a rat aneurysm model. We performed common carotid artery ligation on 96 Long-Evans rats. A treatment group of 48 animals was chosen at random to receive oral doxycycline (3 mg/kg) in addition to standard rat chow, and the control group of 48 animals received standard rat chow only. The major circle of Willis arteries was dissected at 1 year following carotid ligation, and the proportions of animals with aneurysms were compared between groups using Fisher's exact test. Four animals given oral doxycycline and ten control animals expired before 1 year. Of the examined animals, eight saccular intracranial aneurysms were found in 8 of 45 animals which had received doxycycline (17.8%) and seven saccular intracranial aneurysms were found in 7 of 37 control animals (18.9%). There was no significant difference in aneurysm formation between the doxycycline-treated and control groups (P=0.894). Nonspecific MMP inhibition with doxycycline is not effective in preventing intracranial aneurysm formation in a rat model. (orig.)

  15. Failure to use routine prevention of disability (POD assessment resulting In permanent disability

    Directory of Open Access Journals (Sweden)

    Erika Zoulba

    2016-06-01

    Full Text Available Disability is one of problems in leprosy or Morbus Hansen (MH, which can cause the patient loose his autonomy and may affect his social relationship with family and community. Disability occurs due to neurological inflammation that can manifest as silent neuritis (which develops without any pain. Silent neuritis can be recognized early with a routine prevention of disability (POD assessment. A 19-year-old male patient was referred from a District General Hospital with a history of numbness and stiffness of his 4th and 5th fingers of his left hand since 1 month before admittance. The patient was refered by Community Health Center (CHC or PUSKESMAS after a one year treatment and RFT. During his treatment at the CHC, no assessment of peripheral nerve or POD had ever been performed. The POD assessment at our hospital demonstrated sensory deficit at some points of assessment on both palms and reduced muscle strength of the first and 5th fingers in both hands. Nerve conduction velocity (NCV performed at the outpatient of Neurology Department, showed multiple mononeuropathy MH with irreversible damage. Nerve damage is still considered reversible when it occurs less than 6 months. In this case, the silent neuritis was not detected early and there was delayed treatment; as showed by NCV which revealed a manifestation of irreversible nerve damage. Routine POD assessment may detect the condition and appropriate treatment may overcome the nerve damage.

  16. Conflict transformation, stigma, and HIV-preventive structural change.

    Science.gov (United States)

    Miller, Robin Lin; Reed, Sarah J; Francisco, Vincent T; Ellen, Jonathan M

    2012-06-01

    Over the prior decade, structural change efforts have become an important component of community-based HIV prevention initiatives. However, these efforts may not succeed when structural change initiatives encounter political resistance or invoke conflicting values, which may be likely when changes are intended to benefit a stigmatized population. The current study sought to examine the impact of target population stigma on the ability of 13 community coalitions to achieve structural change objectives. Results indicated that coalitions working on behalf of highly stigmatized populations had to abandon objectives more often than did coalitions working for less stigmatized populations because of external opposition to coalition objectives and resultant internal conflict over goals. Those coalitions that were most successful in meeting external challenges used opposition and conflict as transformative occasions by targeting conflicts directly and attempting to neutralize oppositional groups or turn them into strategic allies; less successful coalitions working on behalf of stigmatized groups struggled to determine an appropriate response to opposition. The role of conflict transformation as a success strategy for working on behalf of stigmatized groups is discussed.

  17. Left Atrial Structure and Function in Heart Failure with Preserved Ejection Fraction: A RELAX Substudy.

    Directory of Open Access Journals (Sweden)

    Siddique A Abbasi

    Full Text Available Given the emerging recognition of left atrial structure and function as an important marker of disease in heart failure with preserved ejection fraction (HF-pEF, we investigated the association between left atrial volume and function with markers of disease severity and cardiac structure in HF-pEF. We studied 100 patients enrolled in the PhosphdiesteRasE-5 Inhibition to Improve CLinical Status and EXercise Capacity in Diastolic Heart Failure (RELAX trial who underwent cardiac magnetic resonance (CMR, cardiopulmonary exercise testing, and blood collection before randomization. Maximal left atrial volume index (LAVi; N = 100, left atrial emptying fraction (LAEF; N = 99; including passive and active components (LAEFP, LAEFA; N = 80, 79, respectively were quantified by CMR. After adjustment for multiple testing, maximal LAVi was only associated with age (ρ = 0.39, transmitral filling patterns (medial E/e' ρ = 0.43, and N-terminal pro-BNP (NT-proBNP; ρ = 0.65; all p<0.05. Lower LAEF was associated with older age, higher transmitral E/A ratio and higher NT-proBNP. Peak VO2 and VE/VCO2 slope were not associated with left atrial structure or function. After adjustment for age, sex, transmitral E/A ratio, CMR LV mass, LV ejection fraction, and creatinine clearance, NT-proBNP remained associated with maximal LAVi (β = 0.028, p = 0.0007 and total LAEF (β = -0.033, p = 0.001. Passive and active LAEF were most strongly associated with age and NT-proBNP, but not gas exchange or other markers of ventricular structure or filling properties. Left atrial volume and emptying function are associated most strongly with NT-proBNP and diastolic filling properties, but not significantly with gas exchange, in HFpEF. Further research to explore the relevance of left atrial structure and function in HF-pEF is warranted.

  18. Are the effects of drugs to prevent and to treat heart failure always concordant? The statin paradox and its implications for understanding the actions of antidiabetic medications.

    Science.gov (United States)

    Packer, Milton

    2018-03-22

    Most treatments for chronic heart failure are effective both in preventing its onset and reducing its progression. However, statins prevent the development of heart failure, but they do not decrease morbidity and mortality in those with established heart failure. This apparent discordance cannot be explained by an effect to prevent interval myocardial infarctions. Instead, it seems that the disease that statins were preventing in trials of patients with a metabolic disorder was different from the disease that they were treating in trials of chronic heart failure. The most common phenotype of heart failure in patients with obesity and diabetes is heart failure with a preserved ejection fraction (HFpEF). In this disorder, the anti-inflammatory effects of statins might ameliorate myocardial fibrosis and cardiac filling abnormalities, but these actions may have little relevance to patients with heart failure and a reduced ejection fraction (HFrEF), whose primary derangement is cardiomyocyte loss and stretch. These distinctions may explain why statins were ineffective in trials that focused on HFrEF, but have been reported to produce with favourable effects in observational studies of HFpEF. Similarly, selective cytokine antagonists were ineffective in HFrEF, but have been associated with benefits in HFpEF. These observations may have important implications for our understanding of the effects of antihyperglycaemic medications. Glucagon-like peptide-1 receptor agonists have had neutral effects on heart failure events in people at risk for HFpEF, but have exerted deleterious actions in HFrEF. Similarly, sodium-glucose co-transporter 2 inhibitors, which exert anti-inflammatory effects and reduce heart failure events in patients who are prone to HFpEF, may not be effective in HFrEF. The distinctions between HFrEF and HFpEF may explain why the effects of drugs on heart failure events in diabetes trials may not be relevant to their use in patients with systolic dysfunction

  19. Efficacy and predictors of success of noninvasive ventilation for prevention of extubation failure in critically ill children with heart disease.

    Science.gov (United States)

    Gupta, Punkaj; Kuperstock, Jacob E; Hashmi, Sana; Arnolde, Vickie; Gossett, Jeffrey M; Prodhan, Parthak; Venkataraman, Shekhar; Roth, Stephen J

    2013-04-01

    The study aimed primarily to evaluate the efficacy of noninvasive ventilation (NIV) and to identify possible predictors for success of NIV therapy in preventing extubation failure in critically ill children with heart disease. The secondary objectives of this study were to assess the efficacy of prophylactic NIV therapy initiated immediately after tracheal extubation and to determine the characteristics, outcomes, and complications associated with NIV therapy in pediatric cardiac patients. A retrospective review examined the medical records of all children between the ages 1 day and 18 years who sustained acute respiratory failure (ARF) that required NIV in the cardiovascular intensive care unit (CVICU) at Lucile Packard Children's Hospital between January 2008 and June 2010. Patients were assigned to a prophylactic group if NIV was started directly after extubation and to a nonprophylactic group if NIV was started after signs and symptoms of ARF developed. Patients were designated as responders if they received NIV and did not require reintubation during their CVICU stay and nonresponders if they failed NIV and reintubation was performed. The data collected included demographic data, preexisting conditions, pre-event characteristics, event characteristics, and outcome data. The outcome data evaluated included success or failure of NIV, duration of NIV, CVICU length of stay (LOS), hospital LOS, and hospital mortality. The two complications of NIV assessed in the study included nasal bridge or forehead skin necrosis and pneumothorax. The 221 eligible events during the study period involved 172 responders (77.8 %) and 49 nonresponders (22.2 %). A total of 201 events experienced by the study cohort received continuous positive airway pressure (CPAP), with 156 responders (78 %), whereas 20 events received bilevel positive airway pressure (BiPAP), with 16 responders (80 %). In the study, 58 events (26.3 %) were assigned to the prophylactic group and 163 events (73

  20. Patient participation in patients with heart failure receiving structured home care--a prospective longitudinal study.

    Science.gov (United States)

    Näsström, Lena; Jaarsma, Tiny; Idvall, Ewa; Årestedt, Kristofer; Strömberg, Anna

    2014-12-18

    Patient participation is important for improving outcomes, respect for self-determination and legal aspects in care. However, how patients with heart failure view participation and which factors may be associated with participation is not known. The aim of this study was therefore to describe the influence of structured home care on patient participation over time in patients diagnosed with heart failure, and to explore factors associated with participation in care. The study had a prospective pre-post longitudinal design evaluating the influence of structured home care on participation in patients at four different home care units. Patient participation was measured using 3 scales and 1 single item. Self-care behavior, knowledge, symptoms of depression, socio- demographic and clinical characteristics were measured to explore factors associated with patient participation. Repeated measure ANOVA was used to describe change over time, and stepwise regression analyses were used to explore factors associated with patient participation. One hundred patients receiving structured heart failure home care were included. Mean age was 82 years, 38 were women and 80 were in New York Heart Association functional class III. One aspect of participation, received information, showed a significant change over time and had increased at both six and twelve months. Better self-care behavior was associated with all four scales measuring different aspects of participation. Experiencing lower degree of symptoms of depression, having better knowledge, being of male sex, being of lower age, cohabiting and having home help services were associated with one or two of the four scales measuring different aspects of participation. Patients experienced a fairly high level of satisfaction with participation in care at baseline, and there was a significant improvement over time for participation with regard to received information after being admitted to structured home care. Higher level of

  1. N-acetylcysteine for prevention of acute renal failure in patients with chronic renal insufficiency undergoing cardiac surgery: a prospective, randomized, clinical trial.

    Science.gov (United States)

    Sisillo, Erminio; Ceriani, Roberto; Bortone, Franco; Juliano, Glauco; Salvi, Luca; Veglia, Fabrizio; Fiorentini, Cesare; Marenzi, Giancarlo

    2008-01-01

    To assess the preventive effect of the antioxidant N-acetylcysteine on postoperative acute renal failure in patients with renal insufficiency undergoing cardiac surgery. Randomized, placebo-controlled, prospective study. University cardiology center. Two hundred fifty-four consecutive patients with chronic renal insufficiency (estimated creatinine clearance acute renal failure (> 25% increase in serum creatinine from baseline) and the in-hospital clinical course were evaluated. Acute renal failure occurred in 46% of patients and was associated with increased in-hospital mortality (7% vs. 0.7%; p = .024). It occurred in 52% of control patients and 40% of N-acetylcysteine-treated patients (p = .06). In-hospital mortality and need for renal replacement therapy were not affected by N-acetylcysteine, but a lower percentage of N-acetylcysteine-treated patients required mechanical ventilation prolonged for > 48 hrs (3% vs. 18%; p 4 days (13% vs. 33%; p acute renal failure in patients with renal insufficiency undergoing cardiac surgery.

  2. Structure and dynamics of deep-seated slope failures in the Magura Flysch Nappe, outer Western Carpathians (Czech Republic

    Directory of Open Access Journals (Sweden)

    I. Baron

    2004-01-01

    Full Text Available Deep-seated mass movements currently comprise one of the main morphogenetic processes in the Flysch Belt of the Western Carpathians of Central Europe. These mass movements result in a large spectrum of slope failures, depending on the type of movement and the nature of the bedrock. This paper presents the results of a detailed survey and reconstruction of three distinct deep-seated slope failures in the Raca Unit of the Magura Nappe, Flysch Belt of the Western Carpathians in the Czech Republic. An interdisciplinary approach has enabled a global view of the dynamics and development of these deep-seated slope failures. The three cases considered here have revealed a complex, poly-phase development of slope failure. They are deep-seated ones with depths to the failure surface ranging from 50 to 110m. They differ in mechanism of movement, failure structure, current activity, and total displacement. The main factors influencing their development have been flysch-bedrock structure, lithology, faulting by bedrock separation (which enabled further weakening through deep weathering, geomorphic setting, swelling of smectite-rich clays, and finally heavy rainfall. All of the slope failures considered here seem to have originated during humid phases of the Holocene or during the Late Glacial.

  3. Astragalus Granule Prevents Ca2+ Current Remodeling in Heart Failure by the Downregulation of CaMKII

    Directory of Open Access Journals (Sweden)

    Sinai Li

    2017-01-01

    Full Text Available Background. Astragalus was broadly used for treating heart failure (HF and arrhythmias in East Asia for thousands of years. Astragalus granule (AG, extracted from Astragalus, shows beneficial effect on the treatment of HF in clinical research. We hypothesized that administration of AG prevents the remodeling of L-type Ca2+ current (ICa-L in HF mice by the downregulation of Ca2+/calmodulin-dependent protein kinase II (CaMKII. Methods. HF mice were induced by thoracic aortic constriction (TAC. After 4 weeks of AG treatment, cardiac function and QT interval were evaluated. Single cardiac ventricular myocyte was then isolated and whole-cell patch clamp was used to record action potential (AP and ICa-L. The expressions of L-type calcium channel alpha 1C subunit (Cav1.2, CaMKII, and phosphorylated protein kinase A (p-PKA were examined by western blot. Results. The failing heart manifested distinct electrical remodeling including prolonged repolarization time and altered ICa-L kinetics. AG treatment attenuated this electrical remodeling, supported by AG-related shortened repolarization time, decreased peak ICa-L, accelerated ICa-L inactivation, and positive frequency-dependent ICa-L facilitation. In addition, AG treatment suppressed the overexpression of CaMKII, but not p-PKA, in the failing heart. Conclusion. AG treatment protected the failing heart against electrical remodeling and ICa-L remodeling by downregulating CaMKII.

  4. On the failure behaviour to striking bow penetration of impacted marine-steel structures

    Directory of Open Access Journals (Sweden)

    Prabowo Aditya Rio

    2018-04-01

    Full Text Available Demands for water transportation modes are continuously increasing as rapid economic and industrial growths in the recent decade. Ship as representative of the water transportation is generally needed to carry various products from one location to another. Besides as product carrier, ship also acts as public facility to transport human across islands for number of reasons, such as tourism and vehicle. Considering its importance, structural damage due to accidental loads or so-called impact can cause unacceptable casualties which threat ship passenger, shipping industry and maritime environment in same time. The most frequent impact phenomena occur in forms of collision and grounding, which are targeting side structure and double bottom consecutively. However, since responses of the impacts on structure are highly nonlinear and vary due to development of ship structures, sustainable analysis as an update of pioneer calculation can be beneficial as rational reference for improving safety and navigational instruments. This work aims to assess failures of the side structures subjected to penetration of striking bow in ship-ship collision scenario. Locations of impact are idealized to happen on after-end, midsection and fore-end to provide complete assessment. Striking bow is to be deployed by varying input velocity to observe significance of the fractures on the side structure. This configuration is implemented on the designed collision scenario, and later calculated using nonlinear finite element method (NLFEM. Summary of the solution indicated that the midsection produced the highest resistance against side collision. Breaching of the inner shell was successfully avoided on the fore-end, but the critical damage to the cargo was observed during bow penetration to the after-end region. This location was recommended to be added by longitudinal framing to increase its resistance against ship collision.

  5. On the failure behaviour to striking bow penetration of impacted marine-steel structures

    Science.gov (United States)

    Prabowo, Aditya Rio; Muttaqie, Teguh; Sohn, Jung Min; Bae, Dong Myung; Setiyawan, Agus

    2018-04-01

    Demands for water transportation modes are continuously increasing as rapid economic and industrial growths in the recent decade. Ship as representative of the water transportation is generally needed to carry various products from one location to another. Besides as product carrier, ship also acts as public facility to transport human across islands for number of reasons, such as tourism and vehicle. Considering its importance, structural damage due to accidental loads or so-called impact can cause unacceptable casualties which threat ship passenger, shipping industry and maritime environment in same time. The most frequent impact phenomena occur in forms of collision and grounding, which are targeting side structure and double bottom consecutively. However, since responses of the impacts on structure are highly nonlinear and vary due to development of ship structures, sustainable analysis as an update of pioneer calculation can be beneficial as rational reference for improving safety and navigational instruments. This work aims to assess failures of the side structures subjected to penetration of striking bow in ship-ship collision scenario. Locations of impact are idealized to happen on after-end, midsection and fore-end to provide complete assessment. Striking bow is to be deployed by varying input velocity to observe significance of the fractures on the side structure. This configuration is implemented on the designed collision scenario, and later calculated using nonlinear finite element method (NLFEM). Summary of the solution indicated that the midsection produced the highest resistance against side collision. Breaching of the inner shell was successfully avoided on the fore-end, but the critical damage to the cargo was observed during bow penetration to the after-end region. This location was recommended to be added by longitudinal framing to increase its resistance against ship collision.

  6. Topology optimization of reinforced concrete structures considering control of shrinkage and strength failure

    DEFF Research Database (Denmark)

    Luo, Yangjun; Wang, Michael Yu; Zhou, Mingdong

    2015-01-01

    -dependent force. Under multi-axial stress conditions, the concrete failure surface is well fitted by two Drucker-Prager yield functions. The optimization problem aims at minimizing the cost function under yield strength constraints on concrete elements and a structural shrinkage volume constraint. In conjunction......To take into account the shrinkage effect in the early stage of Reinforced Concrete (RC) design, an effective continuum topology optimization method is presented in this paper. Based on the power-law interpolation, shrinkage of concrete is numerically simulated by introducing an additional design...... with the adjoint-variable sensitivity information, the enhanced aggregation method is utilized to efficiently reduce the computational effort arisen from large-scale strength constraints. Numerical results reveal that the proposed approach can produce a reasonable solution with the least steel reinforcements...

  7. Evaluation Aspects of Building Structures Reconstructed After a Failure or Catastrophe

    Science.gov (United States)

    Krentowski, Janusz R.; Knyziak, Piotr

    2017-10-01

    The article presents the characteristics of several steel structures, among others modernized industrial dye house, school sports hall, truck repair workshop, that have been rebuilt after a disaster or a catastrophe. The structures were analyzed in detail, and the evaluation and reconstruction processes were described. The emergencies that occurred during exploitation of the buildings were the result of multiple mistakes: incorrectly defined intervals between inspections, errors during periodic inspections, incorrect repair work recommendations. The concepts of reinforcement work implemented by the authors, enabling the long-term future failure-free operation of the objects, were presented. Recommendations for monitoring of the facilities, applied after reinforcement or reconstruction, have been formulated. The methodology for the implementation of specialized investigations, such as geodetic, optical, geological, chemical strength tests, both destructive and non-destructive, has been defined. The need to determine the limit values of deformations, deflections, damage or other faults of structural elements and the entire rebuilt facilities, as well as defining conditions for objects’ withdrawal from operation in subsequent exceptional situations was indicated.

  8. Rate Dependent Multicontinuum Progressive Failure Analysis of Woven Fabric Composite Structures under Dynamic Impact

    Directory of Open Access Journals (Sweden)

    James Lua

    2004-01-01

    Full Text Available Marine composite materials typically exhibit significant rate dependent response characteristics when subjected to extreme dynamic loading conditions. In this work, a strain-rate dependent continuum damage model is incorporated with multicontinuum technology (MCT to predict damage and failure progression for composite material structures. MCT treats the constituents of a woven fabric composite as separate but linked continua, thereby allowing a designer to extract constituent stress/strain information in a structural analysis. The MCT algorithm and material damage model are numerically implemented with the explicit finite element code LS-DYNA3D via a user-defined material model (umat. The effects of the strain-rate hardening model are demonstrated through both simple single element analyses for woven fabric composites and also structural level impact simulations of a composite panel subjected to various impact conditions. Progressive damage at the constituent level is monitored throughout the loading. The results qualitatively illustrate the value of rate dependent material models for marine composite materials under extreme dynamic loading conditions.

  9. Fatigue degradation and failure of rotating composite structures - Materials characterisation and underlying mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Gamstedt, E.K.; Andersen, S.I.

    2001-03-01

    The present review concerns rotating composite structures, in which fatigue degradation is of key concern for in-service failure. Such applications are for instance rotor blades in wind turbines, helicopter rotor blades, flywheels for energy storage, marine and aeronautical propellers, and rolls for paper machines. The purpose is to identify areas where impending efforts should be made to make better use of composite materials in these applications. In order to obtain better design methodologies, which would allow more reliable and slender structures, improved test methods are necessary. Furthermore, the relation between structural, component and specimen test results should be better understood than what is presently the case. Improved predictive methods rely on a better understanding of the underlying damage mechanisms. With mechanism-based models, the component substructure or even the material microstructure could be optimised for best possible fatigue resistance. These issues are addressed in the present report, with special emphasis on test methods, and scaling from damage mechanisms to relevant material properties. (au)

  10. Poorer physical fitness is associated with reduced structural brain integrity in heart failure.

    Science.gov (United States)

    Alosco, Michael L; Brickman, Adam M; Spitznagel, Mary Beth; Griffith, Erica Y; Narkhede, Atul; Raz, Naftali; Cohen, Ronald; Sweet, Lawrence H; Colbert, Lisa H; Josephson, Richard; Hughes, Joel; Rosneck, Jim; Gunstad, John

    2013-05-15

    Physical fitness is an important correlate of structural and functional integrity of the brain in healthy adults. In heart failure (HF) patients, poor physical fitness may contribute to cognitive dysfunction and we examined the unique contribution of physical fitness to brain structural integrity among patients with HF. Sixty-nine HF patients performed the Modified Mini Mental State examination (3MS) and underwent brain magnetic resonance imaging. All participants completed the 2-minute step test (2MST), a brief measure of physical fitness. We examined the associations between cognitive performance, physical fitness, and three indices of global brain integrity: total cortical gray matter volume, total white matter volume, and whole brain cortical thickness. Regression analyses adjusting for demographic characteristics, medical variables (e.g., left ventricular ejection fraction), and intracranial volume revealed reduced performance on the 2MST were associated with decreased gray matter volume and thinner cortex (pphysical fitness is common in HF and associated with reduced structural brain integrity. Prospective studies are needed to elucidate underlying mechanisms for the influence of physical fitness on brain health in HF. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Anisotropic damage and dynamic behavior of reinforced concrete structures until failure

    International Nuclear Information System (INIS)

    Chambart, M.

    2009-09-01

    Dynamic loadings such as impact on reinforced concrete structures lead to degradations and structural failures significantly different to the ones observed for quasi-static loadings. Local effects (spalling, compaction...) and global mechanisms (bending, shear, perforation...) are experimentally observed. Wave propagation due to dynamics loadings can lead to failure in tension in a part of a structure or a component previously in compression. Induced damage anisotropy in concrete is partly responsible for the dissymmetry of behavior between tension and compression. Concrete anisotropy can be modelled by means of a second order damage tensor. In the damage model considered, damage growth is governed by the positive extensions. The model, written in the thermodynamics framework, is robust and is able to compute efficiently Reinforced Concrete (RC) structures. The initial anisotropic model is here extended to dynamics by introducing a viscosity law to govern dynamic damage evolution. The strain rate effect observed experimentally in tension (strength increases with strain rate) is reproduced. In compression no strain rate is introduced since inertial forces seem sufficient to reproduce the strength enhancement in dynamics. One also focuses on regularization issues. For high strain rates the solution is regularized since the characteristic time introduced indirectly defines an internal length and since the damage rate is bounded by a maximum damage rate parameter (visco/delay damage law). This visco/delay regularization is efficient at large strain rates, otherwise, the delay in damage evolution is too small to let damage grow in a wide enough zone. For quasi-static or low speed dynamic cases, the regularization is gained by means of classical non-local damage. For intermediary loading rates where both the strain rate effect and the non-local regularization are needed, a non-local delay-damage model is written (and used in 3D computations). The example of a dynamic

  12. Intravenous renal cell transplantation with SAA1-positive cells prevents the progression of chronic renal failure in rats with ischemic-diabetic nephropathy.

    Science.gov (United States)

    Kelly, Katherine J; Zhang, Jizhong; Han, Ling; Wang, Mingsheng; Zhang, Shaobo; Dominguez, Jesus H

    2013-12-15

    Diabetic nephropathy, the most common cause of progressive chronic renal failure and end-stage renal disease, has now reached global proportions. The only means to rescue diabetic patients on dialysis is renal transplantation, a very effective therapy but severely limited by the availability of donor kidneys. Hence, we tested the role of intravenous renal cell transplantation (IRCT) on obese/diabetic Zucker/SHHF F1 hybrid (ZS) female rats with severe ischemic and diabetic nephropathy. Renal ischemia was produced by bilateral renal clamping of the renal arteries at 10 wk of age, and IRCT with genetically modified normal ZS male tubular cells was given intravenously at 15 and 20 wk of age. Rats were euthanized at 34 wk of age. IRCT with cells expressing serum amyloid A had strong and long-lasting beneficial effects on renal function and structure, including tubules and glomeruli. However, donor cells were found engrafted only in renal tubules 14 wk after the second infusion. The results indicate that IRCT with serum amyloid A-positive cells is effective in preventing the progression of chronic kidney disease in rats with diabetic and ischemic nephropathy.

  13. Numerical modeling of liquefaction-induced failure of geo-structures subjected to earthquakes

    International Nuclear Information System (INIS)

    Rapti, Ioanna

    2016-01-01

    The increasing importance of performance-based earthquake engineering analysis points out the necessity to assess quantitatively the risk of liquefaction. In this extreme scenario of soil liquefaction, devastating consequences are observed, e.g. excessive settlements, lateral spreading and slope instability. The present PhD thesis discusses the global dynamic response and interaction of an earth structure-foundation system, so as to determine quantitatively the collapse mechanism due to foundation's soil liquefaction. As shear band generation is a potential earthquake-induced failure mode in such structures, the FE mesh dependency of results of dynamic analyses is thoroughly investigated and an existing regularization method is evaluated. The open-source FE software developed by EDF R and D, called Code-Aster, is used for the numerical simulations, while soil behavior is represented by the ECP constitutive model, developed at Centrale-Supelec. Starting from a simplified model of 1D SH wave propagation in a soil column with coupled hydro-mechanical nonlinear behavior, the effect of seismic hazard and soil's permeability on liquefaction is assessed. Input ground motion is a key component for soil liquefaction apparition, as long duration of main shock can lead to important nonlinearity and extended soil liquefaction. Moreover, when a variation of permeability as function of liquefaction state is considered, changes in the dissipation phase of excess pore water pressure and material behavior are observed, which do not follow a single trend. The effect of a regularization method with enhanced kinematics approach, called first gradient of dilation model, on 1D SH wave propagation is studied through an analytical solution. Deficiencies of the use of this regularization method are observed and discussed, e.g. spurious waves apparition in the soil's seismic response. Next, a 2D embankment-type model is simulated and its dynamic response is evaluated in dry

  14. Focus on Mechanical Failures: Mechanisms and Detection. Proceedings of the Meeting (45th) of the Mechanical Failures Prevention Group Held in Annapolis, Maryland on April 9 - 11, 1999

    Science.gov (United States)

    1991-04-04

    Dickson, S. Lalonde and L. Shiqiong Catastrophic Temperature Increase During the Separation of High Strength Alloys 79 in Tensile Loading D. D. Make/and...Manitoba FRACTOGRAPHY IN IDENTIFYING FAILURE MECHANISMS J.1. Dickson, S. Lalonde and Li Shiqiong Ddpartement de Gdnie Mdtallurgique Ecole Polytechnique P.O...SYSTEM Marc Monaco Agnes Gardiner Naval Ship Systems Engineering Station Philadelphia, PA 19112 Abstract: The Naval Ship Systems Engineering Station

  15. Burden and Prevention of Adverse Cardiac Events in Patients with Concomitant Chronic Heart Failure and Coronary Artery Disease: A Literature Review.

    Science.gov (United States)

    Lavoie, Louis; Khoury, Hanane; Welner, Sharon; Briere, Jean-Baptiste

    2016-06-01

    Chronic heart failure (HF) or coronary artery disease (CAD) confers risk for thromboembolism and secondary adverse cardiac events (ACEs) (e.g., mortality, myocardial infarction, and stroke). When HF and CAD occur concomitantly, ACE risk is reported to be elevated. We investigated ACEs, their epidemiology, and the resulting burden among patients with concomitant HF and CAD through a structured review of recent literature. Antithrombotic treatment for ACE prevention was assessed. Pertinent databases (PubMed, other) were searched for relevant articles published from January 2004 to March 2015. Data collected included ACE incidence, healthcare resource use, costs, change in quality of life attributed to ACEs, and treatment practice for prevention of ACEs in patients with concomitant HF and CAD. Mortality rates for patients with both HF and CAD ranged from 4.9-12.3% at 30 days to 13.7-86% for periods between 9.9 months and 10 years. Incidence of ACEs among HF patients with CAD is, respectively, at least 82% and 15% higher than for patients without HF or without CAD, except for stroke investigated in two studies. All-cause and HF-related hospitalization is the main driver of the economic burden in patients with HF, the majority of whom had CAD origin. Despite high prevalence of ischemic complications, there is limited evidence to support the use of warfarin-type antithrombotics among HF patients. This study confirms that patients with concomitant HF and CAD are at elevated risk for ACEs and suggests the need for effective new antithrombotic treatments to further decrease ischemic complication rates in this population. © 2016 John Wiley & Sons Ltd.

  16. Improving medication titration in heart failure by embedding a structured medication titration plan.

    Science.gov (United States)

    Hickey, Annabel; Suna, Jessica; Marquart, Louise; Denaro, Charles; Javorsky, George; Munns, Andrew; Mudge, Alison; Atherton, John J

    2016-12-01

    To improve up-titration of medications to target dose in heart failure patients by improving communication from hospital to primary care. This quality improvement project was undertaken within three heart failure disease management (HFDM) services in Queensland, Australia. A structured medication plan was collaboratively designed and implemented in an iterative manner, using methods including awareness raising and education, audit and feedback, integration into existing work practice, and incentive payments. Evaluation was undertaken using sequential audits, and included process measures (use of the titration plan, assignment of responsibility) and outcome measures (proportion of patients achieving target dose) in HFDM service patients with reduced left ventricular ejection fraction. Comparison of the three patient cohorts (pre-intervention cohort A n=96, intervention cohort B n=95, intervention cohort C n=89) showed increase use of the titration plan, a shift to greater primary care responsibility for titration, and an increase in the proportion of patients achieving target doses of angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB) (A 37% vs B 48% vs C 55%, p=0.051) and beta-blockers (A 38% vs B 33% vs C 51%, p=0.045). Combining all three cohorts, patients not on target doses when discharged from hospital were more likely to achieve target doses of ACEI/ARB (pplan. A medication titration plan was successfully implemented in three HFDM services and improved transitional communication and achievement of target doses of evidence-based therapies within six months of hospital discharge. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Digital image analysis of ASB-assisted failure of impacted structural materials

    Directory of Open Access Journals (Sweden)

    Longère Patrice

    2015-01-01

    Full Text Available Experimental analysis of fracture mechanisms is a key point to understand and further reproduce physical phenomena involved in structural material failure. Actually, crack propagation under high loading rate is a strongly coupled thermo-mechanical problem involving large deformation, high strain rate and (quasi adiabatic conditions. The work presented herein aims at analyzing the successive steps of the dynamic deterioration of a high strength structural material, namely the ARMOX500T armor steel, leading to the ultimate fracture. The Kalthoff and Winkler impact test, consisting in impacting the edge of a double notched plate, was retained for that purpose. Images are captured at high frame rate (1M frame/s during the impact loading then analyzed according to a line tracking method. Three stages are accordingly observed: first the progressive development of a weak localization of the deformation within a wide zone behind the notch tips, second the propagation of a narrow band of strong localization, and finally the propagation of a crack. The propagation of the white band is associated to the development of an adiabatic shear band (ASB, as a precursor of the crack. Corresponding displacement fields are identified thanks to the adopted line tracking method, allowing for determining the evolution of mechanical quantities, including notably notch tip shear displacement and velocity, ASB-related white band velocity, global and local shear strain and shear strain rate magnitudes, in view of being implemented into numerical models.

  18. Digital image analysis of ASB-assisted failure of impacted structural materials

    Science.gov (United States)

    Longère, Patrice; Roux, Emile; Cherrier, Olivier; Millot, Thierry; Capdeville, Didier; Petit, Jacques

    2015-09-01

    Experimental analysis of fracture mechanisms is a key point to understand and further reproduce physical phenomena involved in structural material failure. Actually, crack propagation under high loading rate is a strongly coupled thermo-mechanical problem involving large deformation, high strain rate and (quasi) adiabatic conditions. The work presented herein aims at analyzing the successive steps of the dynamic deterioration of a high strength structural material, namely the ARMOX500T armor steel, leading to the ultimate fracture. The Kalthoff and Winkler impact test, consisting in impacting the edge of a double notched plate, was retained for that purpose. Images are captured at high frame rate (1M frame/s) during the impact loading then analyzed according to a line tracking method. Three stages are accordingly observed: first the progressive development of a weak localization of the deformation within a wide zone behind the notch tips, second the propagation of a narrow band of strong localization, and finally the propagation of a crack. The propagation of the white band is associated to the development of an adiabatic shear band (ASB), as a precursor of the crack. Corresponding displacement fields are identified thanks to the adopted line tracking method, allowing for determining the evolution of mechanical quantities, including notably notch tip shear displacement and velocity, ASB-related white band velocity, global and local shear strain and shear strain rate magnitudes, in view of being implemented into numerical models.

  19. L-Carnitine prevents the development of ventricular fibrosis and heart failure with preserved ejection fraction in hypertensive heart disease.

    Science.gov (United States)

    Omori, Yosuke; Ohtani, Tomohito; Sakata, Yasushi; Mano, Toshiaki; Takeda, Yasuharu; Tamaki, Shunsuke; Tsukamoto, Yasumasa; Kamimura, Daisuke; Aizawa, Yoshihiro; Miwa, Takeshi; Komuro, Issei; Soga, Tomoyoshi; Yamamoto, Kazuhiro

    2012-09-01

    Prognosis of heart failure with preserved ejection fraction (HFpEF) remains poor because of unknown pathophysiology and unestablished therapeutic strategy. This study aimed to identify a potential therapeutic intervention for HFpEF through metabolomics-based analysis. Metabolomics with capillary electrophoresis time-of-flight mass spectrometry was performed using plasma of Dahl salt-sensitive rats fed high-salt diet, a model of hypertensive HFpEF, and showed decreased free-carnitine levels. Reassessment with enzymatic cycling method revealed the decreased plasma and left-ventricular free-carnitine levels in the HFpEF model. Urinary free-carnitine excretion was increased, and the expression of organic cation/carnitine transporter 2, which transports free-carnitine into cells, was down-regulated in the left ventricle (LV) and kidney in the HFpEF model. L-Carnitine was administered to the hypertensive HFpEF model. L-Carnitine treatment restored left-ventricular free-carnitine levels, attenuated left-ventricular fibrosis and stiffening, prevented pulmonary congestion, and improved survival in the HFpEF model independent of the antihypertensive effects, accompanied with increased expression of fatty acid desaturase (FADS) 1/2, rate-limiting enzymes in forming arachidonic acid, and enhanced production of arachidonic acid, a precursor of prostacyclin, and prostacyclin in the LV. In cultured cardiac fibroblasts, L-carnitine attenuated the angiotensin II-induced collagen production with increased FADS1/2 expression and enhanced production of arachidonic acid and prostacyclin. L-Carnitine-induced increase of arachidonic acid was canceled by knock-down of FADS1 or FADS2 in cultured cardiac fibroblasts. Serum free-carnitine levels were decreased in HFpEF patients. L-carnitine supplementation attenuates cardiac fibrosis by increasing prostacyclin production through arachidonic acid pathway, and may be a promising therapeutic option for HFpEF.

  20. Exercise training prevents the deterioration in the arterial baroreflex control of sympathetic nerve activity in chronic heart failure patients.

    Science.gov (United States)

    Groehs, Raphaela V; Toschi-Dias, Edgar; Antunes-Correa, Ligia M; Trevizan, Patrícia F; Rondon, Maria Urbana P B; Oliveira, Patrícia; Alves, Maria J N N; Almeida, Dirceu R; Middlekauff, Holly R; Negrão, Carlos E

    2015-05-01

    Arterial baroreflex control of muscle sympathetic nerve activity (ABRMSNA) is impaired in chronic systolic heart failure (CHF). The purpose of the study was to test the hypothesis that exercise training would improve the gain and reduce the time delay of ABRMSNA in CHF patients. Twenty-six CHF patients, New York Heart Association Functional Class II-III, EF ≤ 40%, peak V̇o2 ≤ 20 ml·kg(-1)·min(-1) were divided into two groups: untrained (UT, n = 13, 57 ± 3 years) and exercise trained (ET, n = 13, 49 ± 3 years). Muscle sympathetic nerve activity (MSNA) was directly recorded by microneurography technique. Arterial pressure was measured on a beat-to-beat basis. Time series of MSNA and systolic arterial pressure were analyzed by autoregressive spectral analysis. The gain and time delay of ABRMSNA was obtained by bivariate autoregressive analysis. Exercise training was performed on a cycle ergometer at moderate intensity, three 60-min sessions per week for 16 wk. Baseline MSNA, gain and time delay of ABRMSNA, and low frequency of MSNA (LFMSNA) to high-frequency ratio (HFMSNA) (LFMSNA/HFMSNA) were similar between groups. ET significantly decreased MSNA. MSNA was unchanged in the UT patients. The gain and time delay of ABRMSNA were unchanged in the ET patients. In contrast, the gain of ABRMSNA was significantly reduced [3.5 ± 0.7 vs. 1.8 ± 0.2, arbitrary units (au)/mmHg, P = 0.04] and the time delay of ABRMSNA was significantly increased (4.6 ± 0.8 vs. 7.9 ± 1.0 s, P = 0.05) in the UT patients. LFMSNA-to-HFMSNA ratio tended to be lower in the ET patients (P training prevents the deterioration of ABRMSNA in CHF patients. Copyright © 2015 the American Physiological Society.

  1. Transitions of Care Between Acute and Chronic Heart Failure: Critical Steps in the Design of a Multidisciplinary Care Model for the Prevention of Rehospitalization.

    Science.gov (United States)

    Comín-Colet, Josep; Enjuanes, Cristina; Lupón, Josep; Cainzos-Achirica, Miguel; Badosa, Neus; Verdú, José María

    2016-10-01

    Despite advances in the treatment of heart failure, mortality, the number of readmissions, and their associated health care costs are very high. Heart failure care models inspired by the chronic care model, also known as heart failure programs or heart failure units, have shown clinical benefits in high-risk patients. However, while traditional heart failure units have focused on patients detected in the outpatient phase, the increasing pressure from hospital admissions is shifting the focus of interest toward multidisciplinary programs that concentrate on transitions of care, particularly between the acute phase and the postdischarge phase. These new integrated care models for heart failure revolve around interventions at the time of transitions of care. They are multidisciplinary and patient-centered, designed to ensure continuity of care, and have been demonstrated to reduce potentially avoidable hospital admissions. Key components of these models are early intervention during the inpatient phase, discharge planning, early postdischarge review and structured follow-up, advanced transition planning, and the involvement of physicians and nurses specialized in heart failure. It is hoped that such models will be progressively implemented across the country. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  2. The Impact of Rurality on 30-Day Preventable Readmission, Illness Severity, and Risk of Mortality for Heart Failure Medicare Home Health Beneficiaries.

    Science.gov (United States)

    Chen, Hsueh-Fen; Carlson, Erin; Popoola, Taiye; Suzuki, Sumihiro

    2016-01-01

    To examine the impact of rurality on 30-day preventable readmission, and the illness severity and risk of mortality for 30-day preventable readmissions. We analyzed heart failure Medicare beneficiaries who received home health services for postacute care after hospital discharge in 2009. The study was a cross-sectional design with the unit of analysis as the home health episode for postacute care. Data sources included the following: Medicare Beneficiary Summary File, Medicare Provider Analysis Review, Outcome Assessment Information Set, Home Health Agency Research Identifiable File, and Area Health Resources File. The dependent variables were 30-day preventable readmission, and the extreme/major level of illness severity and of risk of mortality for a 30-day preventable readmission. The key independent variable was rurality defined as remote rural, adjacent rural, and micropolitan areas, with urban areas in the reference group. Home health beneficiaries in remote rural areas had 27% lower 30-day preventable readmission than those in urban areas. Home health beneficiaries in adjacent rural areas were 33% less likely to have high illness severity at readmission due to a preventable condition than those in urban areas. Geographical location affects preventable readmission and illness severity of preventable readmission. Patients' geographic location along with patients' risk factors should be taken into consideration in the risk adjustment model for the financial incentive program that penalizes home health agencies with high preventable readmissions. © 2015 National Rural Health Association.

  3. Prevention of falls, malnutrition and pressure ulcers among older persons - nursing staff's experiences of a structured preventive care process.

    Science.gov (United States)

    Lannering, Christina; Ernsth Bravell, Marie; Johansson, Linda

    2017-05-01

    A structured and systematic care process for preventive work, aimed to reduce falls, pressure ulcers and malnutrition among older people, has been developed in Sweden. The process involves risk assessment, team-based interventions and evaluation of results. Since development, this structured work process has become web-based and has been implemented in a national quality registry called 'Senior Alert' and used countrywide. The aim of this study was to describe nursing staff's experience of preventive work by using the structured preventive care process as outlined by Senior Alert. Eight focus group interviews were conducted during 2015 including staff from nursing homes and home-based nursing care in three municipalities. The interview material was subjected to qualitative content analysis. In this study, both positive and negative opinions were expressed about the process. The systematic and structured work flow seemed to only partly facilitate care providers to improve care quality by making better clinical assessments, performing team-based planned interventions and learning from results. Participants described lack of reliability in the assessments and varying opinions about the structure. Furthermore, organisational structures limited the preventive work. © 2016 John Wiley & Sons Ltd.

  4. Failure analysis and structure optimization of the connecting thread of driving shaft in positive displacement motor

    Directory of Open Access Journals (Sweden)

    Xiaohua Zhu

    2016-05-01

    Full Text Available Due to high efficiency in helping breaking rocks, positive displacement motor has a widespread application in the field of oil and gas drilling engineering. However, service life of positive displacement motor becomes shorter resulting from failure of the driving shaft thread. The three-dimensional simulation model of driving shaft’s connecting thread has been developed based on the principle of virtual work, Von Mises yield criterion, and contact nonlinear theory. This article has put forward the plan to optimize structure of driving shaft with straight thread based on the design principle of double-shouldered thread; besides, fatigue life of driving shaft with straight thread before and after optimization has been assessed by resorting to the multiaxial fatigue principle and Brown–Miller critical plane rule. In line with research results, mechanical properties of driving shaft with straight thread are superior to those of driving shaft with taper thread. Under the load of axial drill pressure with fluctuation and alternating torque, fatigue life of driving shaft with straight thread after optimization is greatly improved. This article has not only provided basis for optimizing connecting thread of driving shaft but also boasts of high engineering value for improving service life of positive displacement motor.

  5. Structuring the STD prevention work in the elderly: educational workshops

    Directory of Open Access Journals (Sweden)

    Vanessa Lopes Munhoz Afonso

    2015-10-01

    Full Text Available Background and Objectives: Report educational experiences orienting the elderly population about sexuality and prevention of sexually transmitted diseases. Case description: A professional experience report of STD prevention group in the elderly at a specialized clinic. The educational gerontology was used as a methodology in the production of workshops held from November/2012 to December/2014 to service users. The workshops entitled “Tenda da Sabedoria”, “Baile dos Idosos” and “Roda de Conversa”addressed the sexuality of the elderly, knowledge about transmission and how to prevent it. Actions are always accompanied by the distribution of educational materials, condoms and referrals to testing users for Hepatitis B and C, HIV and syphilis. The group noticed satisfaction of the elderly, interest and effective participation through learning in a simple and enjoyable way. It was also possible to identify elderly interested in multiplying the knowledge with peers and family. Conclusions: The participatory educational process promotes strengthening of elderly network support, enabling an active channel of communication between staff and users, offering subsidies appropriated to prevention work and treatment of diseases. Keywords: Health of the Elderly; Health Education; Communicable Disease Prevention; Health Promotion.

  6. Advanced composites structural concepts and materials technologies for primary aircraft structures. Structural response and failure analysis: ISPAN modules users manual

    Science.gov (United States)

    Hairr, John W.; Huang, Jui-Ten; Ingram, J. Edward; Shah, Bharat M.

    1992-01-01

    The ISPAN Program (Interactive Stiffened Panel Analysis) is an interactive design tool that is intended to provide a means of performing simple and self contained preliminary analysis of aircraft primary structures made of composite materials. The program combines a series of modules with the finite element code DIAL as its backbone. Four ISPAN Modules were developed and are documented. These include: (1) flat stiffened panel; (2) curved stiffened panel; (3) flat tubular panel; and (4) curved geodesic panel. Users are instructed to input geometric and material properties, load information and types of analysis (linear, bifurcation buckling, or post-buckling) interactively. The program utilizing this information will generate finite element mesh and perform analysis. The output in the form of summary tables of stress or margins of safety, contour plots of loads or stress, and deflected shape plots may be generalized and used to evaluate specific design.

  7. High-Resolution Mapping of Chromatin Conformation in Cardiac Myocytes Reveals Structural Remodeling of the Epigenome in Heart Failure.

    Science.gov (United States)

    Rosa-Garrido, Manuel; Chapski, Douglas J; Schmitt, Anthony D; Kimball, Todd H; Karbassi, Elaheh; Monte, Emma; Balderas, Enrique; Pellegrini, Matteo; Shih, Tsai-Ting; Soehalim, Elizabeth; Liem, David; Ping, Peipei; Galjart, Niels J; Ren, Shuxun; Wang, Yibin; Ren, Bing; Vondriska, Thomas M

    2017-10-24

    Cardiovascular disease is associated with epigenomic changes in the heart; however, the endogenous structure of cardiac myocyte chromatin has never been determined. To investigate the mechanisms of epigenomic function in the heart, genome-wide chromatin conformation capture (Hi-C) and DNA sequencing were performed in adult cardiac myocytes following development of pressure overload-induced hypertrophy. Mice with cardiac-specific deletion of CTCF (a ubiquitous chromatin structural protein) were generated to explore the role of this protein in chromatin structure and cardiac phenotype. Transcriptome analyses by RNA-seq were conducted as a functional readout of the epigenomic structural changes. Depletion of CTCF was sufficient to induce heart failure in mice, and human patients with heart failure receiving mechanical unloading via left ventricular assist devices show increased CTCF abundance. Chromatin structural analyses revealed interactions within the cardiac myocyte genome at 5-kb resolution, enabling examination of intra- and interchromosomal events, and providing a resource for future cardiac epigenomic investigations. Pressure overload or CTCF depletion selectively altered boundary strength between topologically associating domains and A/B compartmentalization, measurements of genome accessibility. Heart failure involved decreased stability of chromatin interactions around disease-causing genes. In addition, pressure overload or CTCF depletion remodeled long-range interactions of cardiac enhancers, resulting in a significant decrease in local chromatin interactions around these functional elements. These findings provide a high-resolution chromatin architecture resource for cardiac epigenomic investigations and demonstrate that global structural remodeling of chromatin underpins heart failure. The newly identified principles of endogenous chromatin structure have key implications for epigenetic therapy. © 2017 The Authors.

  8. Pollution prevention and industrial transformation; Evoking structural changes within companies

    NARCIS (Netherlands)

    de Bruijn, Theo; Hofman, Peter

    2000-01-01

    Pollution prevention has developed as an attractive method for improving the environmental performance of companies. Often the concept is promoted in a project format, for instance in a regional perspective or for a specific sector of industry. This article analyzes the contribution of pollution

  9. American Heart Association’s Life’s Simple 7: Avoiding Heart Failure and Preserving Cardiac Structure and Function

    Science.gov (United States)

    Folsom, Aaron R.; Shah, Amil M.; Lutsey, Pamela L.; Roetker, Nicholas S.; Alonso, Alvaro; Avery, Christy L.; Miedema, Michael D.; Konety, Suma; Chang, Patricia P.; Solomon, Scott D.

    2015-01-01

    BACKGROUND Many people may underappreciate the role of lifestyle in avoiding heart failure. We estimated whether greater adherence in middle age to American Heart Association’s Life’s Simple 7 guidelines -- on smoking, body mass, physical activity, diet, cholesterol, blood pressure, and glucose -- is associated with lower lifetime risk of heart failure and greater preservation of cardiac structure and function in old age. METHODS We studied the population-based Atherosclerosis Risk in Communities Study cohort of 13,462 adults aged 45-64 years in 1987-89. From the 1987-89 risk factor measurements, we created a Life’s Simple 7 score (range 0-14, giving 2 points for ideal, 1 point for intermediate, and 0 points for poor components). We identified 2,218 incident heart failure events using surveillance of hospital discharge and death codes through 2011. In addition, in 4,855 participants free of clinical cardiovascular disease in 2011-13, we performed echocardiography from which we quantified left ventricular hypertrophy and diastolic dysfunction. RESULTS One in four participants (25.5%) developed heart failure through age 85. Yet, this lifetime heart failure risk was 14.4% for those with a middle-age Life’s Simple 7 score of 10-14 (optimal), 26.8% for a score of 5-9 (average), and 48.6% for a score of 0-4 (inadequate). Among those with no clinical cardiovascular event, the prevalence of left ventricular hypertrophy in late life was approximately 40% as common, and diastolic dysfunction was approximately 60% as common, among those with an optimal middle-age Life’s Simple 7 score compared with an inadequate score. CONCLUSIONS Greater achievement of American Heart Association’s Life’s Simple 7 in middle-age is associated with a lower lifetime occurrence of heart failure and greater preservation of cardiac structure and function. PMID:25908393

  10. EFFECT OF MITRAL REGURGITATION ON CHRONIC HEART FAILURE COURSE AND STRUCTURE-FUNCTIONAL HEART STATE

    Directory of Open Access Journals (Sweden)

    V. N. Larina

    2009-01-01

    Full Text Available Aim. To evaluate chronic heart failure (CHF course, functional and structural heart changes in patients with functional mitral regurgitation (MR of various degrees.Material and methods. A total of 104 outpatients (60-85 y. o. with CHF of functional class II-IV by NYHA and functional MR of I-II degrees and MR of III-IV degrees were included into the study groups.Results: Patients in both groups were comparable in sex, age, CHF duration, body mass index, systolic and diastolic blood pressure, clinical state by the clinical state scale, quality of life, anxious and depressive status. The majority of patients with MR III had significant left ventricle (LV systolic dysfunction (p=0,029, severe CHF course (p=0,034, received furosemide (p=0.004 and digoxin (p=0,004. They had significant increase in end-diastolic dimension (p<0,001, end-systolic dimension (p<0,001, left atrium (p=0,004, end-diastolic volume (p<0,001, end-systolic volume (p<0,001, pulmonary artery pressure (p<0,001, decrease in LV relative wall thickness (p=0,021 and LV ejection fraction (p<0,001. Patients of this group were hospitalized because of CHF decompensation and ischemic heart disease exacerbation more often (p=0,045.Conclusion. MR can be considered as one of sensitive predictors of LV geometry and function alteration in CHF patients and play an important role in symptoms development.

  11. EFFECT OF MITRAL REGURGITATION ON CHRONIC HEART FAILURE COURSE AND STRUCTURE-FUNCTIONAL HEART STATE

    Directory of Open Access Journals (Sweden)

    V. N. Larina

    2016-01-01

    Full Text Available Aim. To evaluate chronic heart failure (CHF course, functional and structural heart changes in patients with functional mitral regurgitation (MR of various degrees.Material and methods. A total of 104 outpatients (60-85 y. o. with CHF of functional class II-IV by NYHA and functional MR of I-II degrees and MR of III-IV degrees were included into the study groups.Results: Patients in both groups were comparable in sex, age, CHF duration, body mass index, systolic and diastolic blood pressure, clinical state by the clinical state scale, quality of life, anxious and depressive status. The majority of patients with MR III had significant left ventricle (LV systolic dysfunction (p=0,029, severe CHF course (p=0,034, received furosemide (p=0.004 and digoxin (p=0,004. They had significant increase in end-diastolic dimension (p<0,001, end-systolic dimension (p<0,001, left atrium (p=0,004, end-diastolic volume (p<0,001, end-systolic volume (p<0,001, pulmonary artery pressure (p<0,001, decrease in LV relative wall thickness (p=0,021 and LV ejection fraction (p<0,001. Patients of this group were hospitalized because of CHF decompensation and ischemic heart disease exacerbation more often (p=0,045.Conclusion. MR can be considered as one of sensitive predictors of LV geometry and function alteration in CHF patients and play an important role in symptoms development.

  12. Variable Structure PID Control to Prevent Integrator Windup

    Science.gov (United States)

    Hall, C. E.; Hodel, A. S.; Hung, J. Y.

    1999-01-01

    PID controllers are frequently used to control systems requiring zero steady-state error while maintaining requirements for settling time and robustness (gain/phase margins). PID controllers suffer significant loss of performance due to short-term integrator wind-up when used in systems with actuator saturation. We examine several existing and proposed methods for the prevention of integrator wind-up in both continuous and discrete time implementations.

  13. Prevention

    Science.gov (United States)

    ... Error processing SSI file About Heart Disease & Stroke Prevention Heart disease and stroke are an epidemic in ... secondhand smoke. Barriers to Effective Heart Disease & Stroke Prevention Many people with key risk factors for heart ...

  14. Fragility estimation for seismically isolated nuclear structures by high confidence low probability of failure values and bi-linear regression

    International Nuclear Information System (INIS)

    Carausu, A.

    1996-01-01

    A method for the fragility estimation of seismically isolated nuclear power plant structure is proposed. The relationship between the ground motion intensity parameter (e.g. peak ground velocity or peak ground acceleration) and the response of isolated structures is expressed in terms of a bi-linear regression line, whose coefficients are estimated by the least-square method in terms of available data on seismic input and structural response. The notion of high confidence low probability of failure (HCLPF) value is also used for deriving compound fragility curves for coupled subsystems. (orig.)

  15. Construct validity of the Chinese version of the Self-care of Heart Failure Index determined using structural equation modeling.

    Science.gov (United States)

    Kang, Xiaofeng; Dennison Himmelfarb, Cheryl R; Li, Zheng; Zhang, Jian; Lv, Rong; Guo, Jinyu

    2015-01-01

    The Self-care of Heart Failure Index (SCHFI) is an empirically tested instrument for measuring the self-care of patients with heart failure. The aim of this study was to develop a simplified Chinese version of the SCHFI and provide evidence for its construct validity. A total of 182 Chinese with heart failure were surveyed. A 2-step structural equation modeling procedure was applied to test construct validity. Factor analysis showed 3 factors explaining 43% of the variance. Structural equation model confirmed that self-care maintenance, self-care management, and self-care confidence are indeed indicators of self-care, and self-care confidence was a positive and equally strong predictor of self-care maintenance and self-care management. Moreover, self-care scores were correlated with the Partners in Health Scale, indicating satisfactory concurrent validity. The Chinese version of the SCHFI is a theory-based instrument for assessing self-care of Chinese patients with heart failure.

  16. Features of structural and functional state of the heart in patients with chronic heart failure with comorbid hypertension

    Directory of Open Access Journals (Sweden)

    I. V. Drozdova

    2017-06-01

    Full Text Available The aim - to identify structural and functional features of cardiac remodeling in patients with chronic heart failure associated with hypertension. Materials and Methods. Hemodynamic, structural and functional changes have been studied in 77 patients (21 women and 56 men with chronic heart failure with preserved left ventricular ejection fraction using echocardiography. The first group consisted of 46 patients with heart failure and hypertension, the second group included 31 patients with CHF without hypertension. All groups were comparable to age and sex. Results. In patients with heart failure and a history of hypertension remodeling processes were characterized by increase in LAV (17.8%, p<0.05, LVPWd (16.3%, p<0.05, IVSd (12.7%, p<0.05, RWT (22.4%, p<0.05 and ejection fraction (13.3%, p<0.05, compared with patients without hypertension, with a predominance of eccentric and concentric hypertrophy and diastolic dysfunction by type of abnormal relaxation. Conclusions. In CHF patients with hypertension remodeling processes are characterized by walls thickening, increase in left atrium volume, left ventricular myocardial mass, left ventricular ejection fraction with a predominance of eccentric and concentric hypertrophy and diastolic dysfunction by type of abnormal relaxation that are reasonable to use in practice of medical and social expertise.

  17. Potential seismic structural failure modes associated with the Zion Nuclear Plant. Seismic safety margins research program (Phase I). Project VI. Fragilities

    International Nuclear Information System (INIS)

    1979-10-01

    The Zion 1 and 2 Nuclear Power Plant consists of a number of structures. The most important of these from the viewpoint of safety are the containment buildings, the auxiliary building, the turbine building, and the crib house (or intake structure). The evaluation of the potential seismic failure modes and determination of the ultimate seismic capacity of the structures is a complex undertaking which will require a large number of detailed calculations. As the first step in this evaluation, a number of potential modes of structural failure have been determined and are discussed. The report is principally directed towards seismically induced failure of structures. To some extent, modes involving soil foundation failures are discussed in so far as they affect the buildings. However, failure modes involving soil liquefaction, surface faulting, tsunamis, etc., are considered outside the scope of this evaluation

  18. HIV prevention, structural change and social values: the need for an explicit normative approach.

    Science.gov (United States)

    Parkhurst, Justin O

    2012-06-14

    The fact that HIV prevention often deals with politicised sexual and drug taking behaviour is well known, but structural HIV prevention interventions in particular can involve alteration of social arrangements over which there may be further contested values at stake. As such, normative frameworks are required to inform HIV prevention decisions and avoid conflicts between social goals. This paper provides a conceptual review and discussion of the normative issues surrounding structural HIV prevention strategies. It applies political and ethical concepts to explore the contested nature of HIV planning and suggests conceptual frameworks to inform future structural HIV responses. HIV prevention is an activity that cannot be pursued without making value judgements; it is inherently political. Appeals to health outcomes alone are insufficient when intervention strategies have broader social impacts, or when incidence reduction can be achieved at the expense of other social values such as freedom, equality, or economic growth. This is illustrated by the widespread unacceptability of forced isolation which may be efficacious in preventing spread of infectious agents, but conflicts with other social values. While no universal value system exists, the capability approach provides one potential framework to help overcome seeming contradictions or value trade-offs in structural HIV prevention approaches. However, even within the capability approach, valuations must still be made. Making normative values explicit in decision making processes is required to ensure transparency, accountability, and representativeness of the public interest, while ensuring structural HIV prevention efforts align with broader social development goals as well.

  19. Effect of thermo-mechanical loading histories on fatigue crack growth behavior and the threshold in SUS 316 and SCM 440 steels. For prevention of high cycle thermal fatigue failures

    International Nuclear Information System (INIS)

    Okazaki, Masakazu; Muzvidziwa, Milton; Iwasaki, Akira; Kasahara, Naoto

    2014-01-01

    High cycle thermal fatigue failure of pipes induced by fluid temperature change is one of the interdisciplinary issues to be concerned for long term structural reliability of high temperature components in energy systems. In order to explore advanced life assessment methods to prevent the failure, fatigue crack propagation tests were carried out in a low alloy steel and an austenitic stainless steel under typical thermal and thermo-mechanical histories. Special attention was paid to both the effect of thermo-mechanical loading history on the fatigue crack threshold, as well as to the applicability of continuum fracture mechanics treatment to small or short cracks. It was shown experimentally that the crack-based remaining fatigue life evaluation provided more reasonable assessment than the traditional method based on the semi-empirical law in terms of 'usage factor' for high cycle thermal fatigue failure that is employed in JSME Standard, S017. The crack propagation analysis based on continuum fracture mechanics was almost successfully applied to the small fatigue cracks of which size was comparable to a few times of material grain size. It was also shown the thermo-mechanical histories introduced unique effects to the prior fatigue crack wake, resulting in occasional change in the fatigue crack threshold. (author)

  20. beta-blockade with nebivolol for prevention of acute ischaemic events in elderly patients with heart failure

    NARCIS (Netherlands)

    Ambrosio, Giuseppe; Flather, Marcus D.; Boehm, Michael; Cohen-Solal, Alain; Murrone, Adriano; Mascagni, Flavio; Spinucci, Giulio; Conti, Maria Giovanna; van Veldhuisen, Dirk J.; Tavazzi, Luigi; Coats, Andrew J. S.

    Objectives This subanalysis of the Study of the Effects of Nebivolol Intervention on Outcomes and Hospitalisation in Seniors with Heart Failure (SENIORS) investigates whether treatment with nebivolol, a beta-blocker with nitric oxide-releasing properties, can provide additional benefits besides its

  1. beta-blockade with nebivolol for prevention of acute ischaemic events in elderly patients with heart failure

    NARCIS (Netherlands)

    Ambrosio, G.; Flather, M. D.; Boehm, M.; Cohen-Solal, A.; Murrone, A.; Mascagni, F.; Spinucci, G.; Conti, M. G.; van Veldhuisen, D. J.; Tavazzi, L.; Coats, A. J. S.

    2011-01-01

    Aim. This subanalysis of the Study of the Effects of Nebivolol Intervention on Outcomes and Hospitalisation in Seniors with Heart Failure (SENIORS) investigates whether treatment with nebivolol, a p-blocker with nitric oxide-releasing properties, can provide additional benefits besides its effects

  2. Effect of organizational structures and types of construction on perceptions of factors contributing to project failure in pakistan

    International Nuclear Information System (INIS)

    Gazder, U.; Khan, R.A.

    2018-01-01

    The construction industry is viewed as the regulator of national economy globally. Its importance in Pakistan has increased greatly because of the involvement of international funding agencies in infrastructure projects. The feasibility of such projects is largely dependent upon the satisfaction of multiple stakeholders. Hence, it is important to explore the factors considered by different construction organizations in evaluating the failure of their projects. This study focuses on providing a rating of factors affecting construction project failures in the construction industry of Karachi. In addition to that, difference in perception between professionals belonging to different construction projects and organizational structures has also been evaluated. The results of this study show that factors related to project planning and management are rated higher by professionals in general. Secondly, it was also observed that client satisfaction and its related factors were rated higher by organizations with project based management structures. (author)

  3. Subchronic treatment with acai frozen pulp prevents the brain oxidative damage in rats with acute liver failure.

    Science.gov (United States)

    de Souza Machado, Fernanda; Kuo, Jonnsin; Wohlenberg, Mariane Farias; da Rocha Frusciante, Marina; Freitas, Márcia; Oliveira, Alice S; Andrade, Rodrigo B; Wannmacher, Clovis M D; Dani, Caroline; Funchal, Claudia

    2016-12-01

    Acai has been used by the population due to its high nutritional value and its benefits to health, such as its antioxidant properties. The aim of this study was to evaluate the protective effect of acai frozen pulp on oxidative stress parameters in cerebral cortex, hippocampus and cerebellum of Wistar rats treated with carbon tetrachloride (CCl 4 ). Thirty male Wistar rats (90-day-old) were orally treated with water or acai frozen pulp for 14 days (7 μL/g). On the 15th day, half of the animals received treatment with mineral oil and the other half with CCl 4 (3.0 mL/kg). The cerebral cortex, hippocampus and cerebellum were dissected and used for analysis of creatine kinase activity (CK), thiobarbituric acid reactive substances (TBARS), carbonyl, sulfhydryl, and the activity of antioxidant enzymes catalase (CAT) and superoxide dismutase (SOD). Statistical analysis was performed by ANOVA followed by Tukey's post-test. CCl 4 was able to inhibit CK activity in all tissues tested and to provoke lipid damage in cerebral cortex and cerebellum, and protein damage in the three tissues tested. CCl 4 enhanced CAT activity in the cerebral cortex, and inhibited CAT activity in the hippocampus and cerebellum and reduced SOD activity in all tissues studied. Acai frozen pulp prevented the inhibition of CK, TBARS, carbonyl and CAT activity in all brain structures and only in hippocampus for SOD activity. Therefore, acai frozen pulp has antioxidant properties and maybe could be useful in the treatment of some diseases that affect the central nervous system that are associated with oxidative damage.

  4. Reliability analysis of redundant structures, taking into account the dynamic effects of component failures and repair of damaged components

    International Nuclear Information System (INIS)

    Fujita, Munehisa.

    1990-01-01

    The dissertation explains an approach for further development of a method for the calculation of the reliability of redundant, statically and/or dynamically responding structures, taking into account the dynamic load shift in case of brittle fracture of structural components, and quantifying the favourable effects of repairs with regard to overall reliability. The first approach is done by failure tree analysis, which, however, is shown to be an extremely complex and costly method if the repair effects are included in the analysis. Another, simplified model for calculation of extreme loads is presented, which offers the possibility of assessing the impact of repair by means of the Markovian chain model. (orig.) [de

  5. Structures, stresses, and fluctuations in the delayed failure of colloidal gel

    NARCIS (Netherlands)

    Lindstrom, S.B.; Kodger, T.E.; Sprakel, J.H.B.; Weitz, D.A.

    2012-01-01

    Sample-spanning networks of aggregated colloidal particles have a finite stiffness and deform elastically when subjected to a small shear stress. After some period of creep, these gels ultimately suffer catastrophic failure. This delayed yielding is governed by the association and dissociation

  6. Environmentally Friendly Corrosion Preventative Compounds for Ground Support Structures

    Science.gov (United States)

    Montgomery Eliza L.; Calle, Luz, Marina; Curran, Jerome P.; Kolody, Mark R.

    2013-01-01

    The need to use environmentally friendly technologies throughout future space-related launch programs prompted a study aimed at replacing current petroleum and solvent-based Corrosion Preventive Compounds (CPCs) with environmentally friendly alternatives. The work in this paper focused on the identification and evaluation of environmentally friendly CPCs for use in protecting flight hardware and ground support equipment from atmospheric corrosion. CPCs are used as temporary protective coatings and must survive in the aggressive coastal marine environment that exists throughout the Kennedy Space Center, Florida. The different protection behaviors of fifteen different oily film CPCs, both common petroleum-based and newer environmentally friendly types, were evaluated on various steel and aluminum substrates. CPC and substrate systems were subjected to atmospheric testing at the Kennedy Space Center's Beachside Atmospheric Corrosion Test Site, as well as cyclic accelerated corrosion testing. Each CPC also underwent physical characterization and launch-related compatibility testing. The results for the fifteen CPC systems are presented in this paper.

  7. Corrosion induced failure analysis of subsea pipelines

    International Nuclear Information System (INIS)

    Yang, Yongsheng; Khan, Faisal; Thodi, Premkumar; Abbassi, Rouzbeh

    2017-01-01

    Pipeline corrosion is one of the main causes of subsea pipeline failure. It is necessary to monitor and analyze pipeline condition to effectively predict likely failure. This paper presents an approach to analyze the observed abnormal events to assess the condition of subsea pipelines. First, it focuses on establishing a systematic corrosion failure model by Bow-Tie (BT) analysis, and subsequently the BT model is mapped into a Bayesian Network (BN) model. The BN model facilitates the modelling of interdependency of identified corrosion causes, as well as the updating of failure probabilities depending on the arrival of new information. Furthermore, an Object-Oriented Bayesian Network (OOBN) has been developed to better structure the network and to provide an efficient updating algorithm. Based on this OOBN model, probability updating and probability adaptation are performed at regular intervals to estimate the failure probabilities due to corrosion and potential consequences. This results in an interval-based condition assessment of subsea pipeline subjected to corrosion. The estimated failure probabilities would help prioritize action to prevent and control failures. Practical application of the developed model is demonstrated using a case study. - Highlights: • A Bow-Tie (BT) based corrosion failure model linking causation with the potential losses. • A novel Object-Oriented Bayesian Network (OOBN) based corrosion failure risk model. • Probability of failure updating and adaptation with respect to time using OOBN model. • Application of the proposed model to develop and test strategies to minimize failure risk.

  8. Modelling of Diffuse Failure and Fluidization in geo materials and Geo structures; Modelizacion de la rotura y fluidificacion en geomateriales y geoestructuras

    Energy Technology Data Exchange (ETDEWEB)

    Pastor, M.

    2013-06-01

    Failure of geo structures is caused by changes in effective stresses induced by external loads (earthquakes, for instance), change in the pore pressures (rain), in the geometry (erosion), or in materials properties (chemical attack, degradation, weathering). Landslides can by analysed as the failure of a geo structure, the slope. There exist many alternative classifications of landslides can be analyzed as the failure of a geo structure, the slope. There exist many alternative classifications of landslides, but we will consider here a simple classification into slides and flows. In the case of slides, the failure consists on the movement of a part of the slope with deformations which concentrate in a narrow zone, the failure surface. This can be idealized as localized failure, and it is typical of over consolidated or dense materials exhibiting softening. On the other hand, flows are made of fluidized materials, flowing in a fluid like manner. This mechanism of failure is known as diffuse failure, and has received much less attention by researchers. Modelling of diffuse failure of slopes is complex, because there appear difficulties in the mathematical, constitutive and numerical models, which have to account for a phase transition. This work deals with modeling, and we will present here some tools recently developed by the author and the group to which he belongs. (Author)

  9. The value of second polar body detection 4 hours after insemination and early rescue ICSI in preventing complete fertilisation failure in patients with borderline semen.

    Science.gov (United States)

    Jin, Haixia; Shu, Yimin; Dai, Shanjun; Peng, Zhaofeng; Shi, Senlin; Sun, Yingpu

    2014-01-01

    In this study we evaluated the value of short-time insemination and early rescue intra-cytoplasmic sperm injection (ICSI) in preventing the occurrence of complete fertilisation failure for mild or moderate male infertility patients. A total of 866 couples with borderline semen who underwent in vitro fertilisation treatment in 2010 were included. Regular insemination was performed between January and June of 2010 and short-term insemination was performed from July through December 2010, where, as early as 4h after insemination, oocytes were denuded from cumulus cells and extrusion of the second polar body was evaluated. Of the 4153 mature oocytes with a detectable second polar body 4 h after insemination, 3874 (93.3%) showed signs of fertilisation on Day 1. Where no second polar body was present in any of the retrieved oocytes for a given patient, rescue ICSI was performed immediately. Similar rates of normal fertilisation and percentage of good-quality embryos were obtained between early rescue ICSI and regular ICSI. Clinical pregnancy occurred in 16 of 43 patients (37.2%) receiving early rescue ICSI. Our results showed early rescue ICSI in combination with evaluation of the second polar body 4 h following insemination is an effective method to prevent complete fertilisation failure for patients with mild or moderate male infertility.

  10. A structured analysis of in vitro failure loads and failure modes of fiber, metal, and ceramic post-and-core systems.

    NARCIS (Netherlands)

    Fokkinga, W.A.; Kreulen, C.M.; Vallittu, P.K.; Creugers, N.H.J.

    2004-01-01

    PURPOSE: This study sought to aggregate literature data on in vitro failure loads and failure modes of prefabricated fiber-reinforced composite (FRC) post systems and to compare them to those of prefabricated metal, custom-cast, and ceramic post systems. MATERIALS AND METHODS: The literature was

  11. Calpastatin overexpression prevents progression of S-1,2-dichlorovinyl-L-cysteine (DCVC)-initiated acute renal injury and renal failure (ARF) in diabetes

    International Nuclear Information System (INIS)

    Dnyanmote, Ankur V.; Sawant, Sharmilee P.; Lock, Edward A.; Latendresse, John R.; Warbritton, Alan A.; Mehendale, Harihara M.

    2006-01-01

    Previously we have shown that 90% of streptozotocin (STZ)-induced type-1 diabetic (DB) mice survive from acute renal failure (ARF) and death induced by a normally LD 9 dose (75 mg/kg, i.p.) of the nephrotoxicant S-1,2-dichlorovinyl-L-cysteine (DCVC). This remarkable protection is due to a combination of slower progression of DCVC-initiated renal injury and increased compensatory nephrogenic tissue repair in the DB kidneys. BRDU immunohistochemistry revealed that the DB condition led to 4-fold higher number of proximal tubular cells (PTC) entering S-phase of cell cycle. In the present study, we tested the hypothesis that DB-induced augmentation of PTC into S-phase is accompanied by overexpression of the calpain-inhibitor calpastatin, which endogenously prevents the progression of DCVC-initiated renal injury mediated by the calpain escaping out of damaged PTCs. Immunohistochemical detection of renal calpain and its activity in the urine, over a time course after treatment with the LD 9 dose of DCVC, indicated progressive increase in leakage of calpain into the extracellular spaces of the injured PTCs of the non-diabetic (NDB) kidneys as compared to the DB kidneys. Calpastatin expression was minimally detected in the NDB kidneys, using immunohistochemistry, over the time course. On the other hand, consistently higher number of tubules in the DB kidney showed calpastatin expression over the time course. The lower leakage of calpain in the DB kidneys was commensurate with constitutively higher expression of calpastatin in the S-phase-laden PTCs of these mice. To test the protective role of newly divided/dividing PTCs, DB mice were given the anti-mitotic agent colchicine (CLC) (2 mg/kg and 1.5 mg/kg, i.p., on days 8 and 10 after STZ injection) prior to challenge with a LD 9 dose of DCVC, which led to 100% mortality by 48 h. Mortality was due to rapid progression of DCVC-initiated renal injury, suggesting that newly divided/dividing cells are instrumental in mitigating

  12. Real-Time Smart Grids Control for Preventing Cascading Failures and Blackout using Neural Networks: Experimental Approach for N-1-1 Contingency

    Science.gov (United States)

    Zarrabian, Sina; Belkacemi, Rabie; Babalola, Adeniyi A.

    2016-12-01

    In this paper, a novel intelligent control is proposed based on Artificial Neural Networks (ANN) to mitigate cascading failure (CF) and prevent blackout in smart grid systems after N-1-1 contingency condition in real-time. The fundamental contribution of this research is to deploy the machine learning concept for preventing blackout at early stages of its occurrence and to make smart grids more resilient, reliable, and robust. The proposed method provides the best action selection strategy for adaptive adjustment of generators' output power through frequency control. This method is able to relieve congestion of transmission lines and prevent consecutive transmission line outage after N-1-1 contingency condition. The proposed ANN-based control approach is tested on an experimental 100 kW test system developed by the authors to test intelligent systems. Additionally, the proposed approach is validated on the large-scale IEEE 118-bus power system by simulation studies. Experimental results show that the ANN approach is very promising and provides accurate and robust control by preventing blackout. The technique is compared to a heuristic multi-agent system (MAS) approach based on communication interchanges. The ANN approach showed more accurate and robust response than the MAS algorithm.

  13. Mediterranean Diet and Other Dietary Patterns in Primary Prevention of Heart Failure and Changes in Cardiac Function Markers: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Karina Sanches Machado d’Almeida

    2018-01-01

    Full Text Available Background: Heart failure (HF is a complex syndrome and is recognized as the ultimate pathway of cardiovascular disease (CVD. Studies using nutritional strategies based on dietary patterns have proved to be effective for the prevention and treatment of CVD. Although there are studies that support the protective effect of these diets, their effects on the prevention of HF are not clear yet. Methods: We searched the Medline, Embase, and Cochrane databases for studies that examined dietary patterns, such as dietary approaches to stop hypertension (DASH diet, paleolithic, vegetarian, low-carb and low-fat diets and prevention of HF. No limitations were used during the search in the databases. Results: A total of 1119 studies were identified, 14 met the inclusion criteria. Studies regarding the Mediterranean, DASH, vegetarian, and Paleolithic diets were found. The Mediterranean and DASH diets showed a protective effect on the incidence of HF and/or worsening of cardiac function parameters, with a significant difference in relation to patients who did not adhere to these dietary patterns. Conclusions: It is observed that the adoption of Mediterranean or DASH-type dietary patterns may contribute to the prevention of HF, but these results need to be analyzed with caution due to the low quality of evidence.

  14. Mediterranean Diet and Other Dietary Patterns in Primary Prevention of Heart Failure and Changes in Cardiac Function Markers: A Systematic Review.

    Science.gov (United States)

    Sanches Machado d'Almeida, Karina; Ronchi Spillere, Stefanny; Zuchinali, Priccila; Corrêa Souza, Gabriela

    2018-01-10

    Heart failure (HF) is a complex syndrome and is recognized as the ultimate pathway of cardiovascular disease (CVD). Studies using nutritional strategies based on dietary patterns have proved to be effective for the prevention and treatment of CVD. Although there are studies that support the protective effect of these diets, their effects on the prevention of HF are not clear yet. We searched the Medline, Embase, and Cochrane databases for studies that examined dietary patterns, such as dietary approaches to stop hypertension (DASH diet), paleolithic, vegetarian, low-carb and low-fat diets and prevention of HF. No limitations were used during the search in the databases. A total of 1119 studies were identified, 14 met the inclusion criteria. Studies regarding the Mediterranean, DASH, vegetarian, and Paleolithic diets were found. The Mediterranean and DASH diets showed a protective effect on the incidence of HF and/or worsening of cardiac function parameters, with a significant difference in relation to patients who did not adhere to these dietary patterns. It is observed that the adoption of Mediterranean or DASH-type dietary patterns may contribute to the prevention of HF, but these results need to be analyzed with caution due to the low quality of evidence.

  15. Prevention

    Science.gov (United States)

    ... Contact Aging & Health A to Z Find a Geriatrics Healthcare Professional Medications & Older Adults Making Your Wishes ... Prevention Hearing Loss Heart Attack High Blood Pressure Nutrition Osteoporosis Shingles Skin Cancer Related News Quitting Smoking, ...

  16. Failure of aluminium metal spray/organic duplex coating systems on structural steel

    OpenAIRE

    Sumon, T. A.; Scantlebury, J. D.; Lyon, S. B.

    2013-01-01

    Individually, aluminium metal spray (AMS) and organic paints are well established as effective protective coatings for steel substrates. These coatings are also frequently used together as duplex systems where their combination should produce a synergistic effect. However in certain, mainly marine, environments premature failure of such coatings, involving early blistering of the paint, has been observed in service after 3-5 years. This work aims to understand the mechanisms associated with t...

  17. The Effect of Education on Preventive Behaviors of Failure to Thrive in Mothers with Children Aged One to Five Years: Applied Health Belief Model

    Directory of Open Access Journals (Sweden)

    Mahtab Navabi

    2017-04-01

    Full Text Available Abstract Background: One of the common and important health problems is failure to thrive in childhood. The purpose of this study was to determine the effect of education on preventive behaviors of failure to thrive in mothers with children based on health belief model. Materials and Methods: This study is an interventional one in which 100 mothers with children one to five years involved (samples divided into two case and control groups, each of 50 sampling was done by a simple random method. For collecting information, a researcher-made questionnaire based on the health belief model and performance check list were used. Then, case group was trained for one month. 3 months after training, data were gathered and analyzed by Spss20 software. In addition to descriptive statistics, tests such as Chi-square, paired t-test and independent T-test were used. Results: The mean age of case and control was 29.98±5.51 and 25.35±5.30 years old, respectively. The average age of children was 23.31 ± 13.14 and 27.55 ± 14.01months, respectively. Before the intervention, no significant difference was seen between groups. The average score in case group before intervention was as: knowledge(31.87±14.24, perceived susceptibility(64.23±5.86, perceived severity(64.41±9.34, perceived benefits(61.75±6.79, perceived barriers(67.91±8.14, self-efficacy(68.00±7.87, cues to action(44.53±6.82 and action(70.00±9.77. However, after the intervention, significant differences between groups in all variables were obserred. Conclusion: According to the results, education based on health belief model is recommended for promoting preventive behaviors of failure to thrive.

  18. Isoniazid-Induced Severe Hepatotoxicity: An Infrequent but Preventable Cause of Liver Failure in Children Treated for Latent Tuberculosis Infection

    Directory of Open Access Journals (Sweden)

    Dan Desrochers

    2011-01-01

    Full Text Available Isoniazid (INH monotherapy has gained widespread acceptance as an efficacious therapy for latent tuberculosis infection (LTBI especially in low-prevalence settings. Although INH related hepatotoxicity is well recognized, progression to severe liver dysfunction requiring care at a transplant center remains unpredictable. We report the management of a five year-old girl who developed progressive liver failure due to INH prophylaxis. This highlights the potential severity of INH related hepatic injury and underscores the significance of vigilant clinical monitoring throughout the duration of the therapy in children.

  19. Effects of structured heart failure disease management on mortality and morbidity depend on patients' mood: results from the Interdisciplinary Network for Heart Failure Study.

    Science.gov (United States)

    Gelbrich, Götz; Störk, Stefan; Kreißl-Kemmer, Sonja; Faller, Hermann; Prettin, Christiane; Heuschmann, Peter U; Ertl, Georg; Angermann, Christiane E

    2014-10-01

    Depression is common in heart failure (HF) and associated with adverse outcomes. Randomized comparisons of the effectiveness of HF care strategies by patients' mood are scarce. We therefore investigated in a randomized trial a structured collaborative disease management programme (HeartNetCare-HF™; HNC) recording mortality, morbidity, and symptoms in patients enrolled after hospitalization for decompensated systolic HF according to their responses to the 9-item Patient Health Questionnaire (PHQ-9) during an observation period of 180 days. Subjects scoring <12/≥12 were categorized as non-depressed/depressed, and those ignoring the questionnaire as PHQ-deniers. Amongst 715 participants (69 ± 12 years, 29% female), 141 (20%) were depressed, 466 (65%) non-depressed, and 108 (15%) PHQ-deniers. The composite endpoint of mortality and re-hospitalization was neutral overall and in all subgroups. However, HNC reduced mortality risk in both depressed and non-depressed patients [adjusted hazard ratios (HRs) 0.12, 95% confidence interval (CI) 0.03-0.56, P = 0.006, and 0.49, 95% CI 0.25-0.93, P = 0.03, respectively], but not in PHQ-deniers (HR 1.74, 95% CI 0.77-3.96, P = 0.19; P = 0.006 for homogeneity of HRs). Average frequencies of patient contacts in the HNC arm were 12.8 ± 7.9 in non-depressed patients, 12.4 ± 7.1 in depressed patients, and 5.5 ± 7.2 in PHQ-deniers (P < 0.001). Early after decompensation, HNC reduced mortality risk in non-depressed and even more in depressed subjects, but not in PHQ-deniers. This suggests that differential acceptability and chance of success of care strategies such as HNC might be predicted by appropriate assessment of patients' baseline characteristics including psychological disposition. These post-hoc results should be reassessed by prospective evaluation of HNC in larger HF populations. © 2014 The Authors. European Journal of Heart Failure © 2014 European Society of Cardiology.

  20. Risk and prevention of graft failure in patients with preexisting donor-specific HLA antibodies undergoing unmanipulated haploidentical SCT.

    Science.gov (United States)

    Yoshihara, S; Maruya, E; Taniguchi, K; Kaida, K; Kato, R; Inoue, T; Fujioka, T; Tamaki, H; Ikegame, K; Okada, M; Soma, T; Hayashi, K; Fujii, N; Onuma, T; Kusunoki, Y; Saji, H; Ogawa, H

    2012-04-01

    A role of donor-specific HLA antibodies (DSA) in graft failure after SCT has been suggested, but the relevance of DSA in unmanipulated haploidentical SCT (haplo-SCT) remains unknown. We prospectively examined HLA antibodies using the Luminex-based single Ag assay for 79 adult patients undergoing unmanipulated haplo-SCT. Among them, 16 (20.2%) were HLA Ab-positive, including five patients with antibodies not corresponding to donor HLA Ags and 11 DSA-positive patients. Of the 11 DSA-positive patients, five received treatments to decrease DSA levels, including two, who received plasma exchange and rituximab, two who received platelet transfusions from healthy-related donors having DSA-corresponding HLA Ags and one who received bortezomib. Platelet transfusion was the most simple and effective treatment option for class I DSA. The cumulative incidence of neutrophil recovery was significantly lower in pretransplant (post-treatment) DSA-positive patients than in DSA-negative patients (61.9 vs 94.4%, P=0.026). Notably, three of five patients with high levels of DSA had graft failure. Donors should be selected on the basis of an evaluation of HLA antibodies. If haplo-SCT from donors with HLA Ags that correspond to high levels of DSA must be performed, then recipients should be treated for DSA to improve the chances of successful donor engraftment.

  1. Esthetic failure in implant dentistry.

    Science.gov (United States)

    Fuentealba, Rodrigo; Jofré, Jorge

    2015-01-01

    The definition of failure for dental implants has evolved from lack of osseointegration to increased concern for other aspects, such as esthetics. However, esthetic failure in implant dentistry has not been well defined. Although multiple esthetic indices have been validated for objectively evaluating clinical outcomes, including failure of an implant-supported crown, only one author has determined a failure threshold. On the basis of objective indices, esthetic failures in implant dentistry can be categorized as pink-tissue failures and white-tissue failures. This article discusses esthetic failures, the factors involved in these failures, and their prevention and treatment. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Applicability of the bi-material notch model to analysis of failure initiation in compound structures

    Czech Academy of Sciences Publication Activity Database

    Klusák, Jan; Knésl, Zdeněk

    2008-01-01

    Roč. 4, č. 13 (2008), s. 7-10 ISSN 1801-1217. [Mechanika kompozitních materiálů a konstrukcí. Praha, 13.03.2008] R&D Projects: GA ČR GA101/08/0994 Institutional research plan: CEZ:AV0Z20410507 Keywords : bi-material notch * failure initiation * composite materials Subject RIV: JL - Materials Fatigue, Friction Mechanics http://www.bulletin-am.cz/index.php/vam/issue/view/15

  3. NASA Prototype All Composite Tank Cryogenic Pressure Tests to Failure with Structural Health Monitoring

    Science.gov (United States)

    Werlink, Rudolph J.; Pena, Francisco

    2015-01-01

    This Paper will describe the results of pressurization to failure of 100 gallon composite tanks using liquid nitrogen. Advanced methods of health monitoring will be compared as will the experimental data to a finite element model. The testing is wholly under NASA including unique PZT (Lead Zirconate Titanate) based active vibration technology. Other technologies include fiber optics strain based systems including NASA AFRC technology, Acoustic Emission, Acellent smart sensor, this work is expected to lead to a practical in-Sutu system for composite tanks.

  4. Reliability based topology optimization for continuum structures with local failure constraints

    DEFF Research Database (Denmark)

    Luo, Yangjun; Zhou, Mingdong; Wang, Michael Yu

    2014-01-01

    is employed to aggregate the selected active constraints using a general K–S function, which avoids expensive computational cost from the large-scale nature of local failure constraints. Several numerical examples are given to demonstrate the validity of the present method.......-related) target performance constraints. In order to overcome the stress singularity phenomenon caused by the combined stress and reliability constraints, a reduction strategy on target reliability index is proposed and utilized together with the ε-relaxation approach. Meanwhile, an enhanced aggregation method...

  5. Prevention

    DEFF Research Database (Denmark)

    Halken, S; Høst, A

    2001-01-01

    , breastfeeding should be encouraged for 4-6 months. In high-risk infants a documented extensively hydrolysed formula is recommended if exclusive breastfeeding is not possible for the first 4 months of life. There is no evidence for preventive dietary intervention neither during pregnancy nor lactation...... populations. These theories remain to be documented in proper, controlled and prospective studies. Breastfeeding and the late introduction of solid foods (>4 months) is associated with a reduced risk of food allergy, atopic dermatitis, and recurrent wheezing and asthma in early childhood. In all infants....... Preventive dietary restrictions after the age of 4-6 months are not scientifically documented....

  6. Defective boron nitride nanotubes: mechanical properties, electronic structures and failure behaviors

    Science.gov (United States)

    Wang, Huan; Ding, Ning; Zhao, Xian; Wu, Chi-Man Lawrence

    2018-03-01

    Due to their excellent physical and chemical characteristics, boron nitride nanotubes (BNNTs) are regarded as a complementary addition to carbon nanotubes. Pioneer studies have demonstrated that defects in carbon nanotubes are considered tools for tuning the physical properties of these materials. In the present work, investigation on the mechanical and electronic properties of pristine and defective BNNTs was performed using the density functional theory method. The analysis on the intrinsic strength, stiffness, and failure critical strain of different types of BNNTs was conducted systematically. The computing results showed that the intrinsic strength of BNNTs decreased linearly with the increased Stone–Wales (SW) defect density around the axis. The SW defect density along the axis played a minor role on the changing of mechanical properties of BNNTs. The BNNT with a B vacancy expressed higher intrinsic strength than that of the N vacancy model. The final failure of the pristine BNNTs was due to the fracture of the Type1 bonds under the mechanical strain. Defects like SW or vacancy are served as the initial break site of BNNTs. Applying strain or creating defects are both effective methods for reducing the band gap of BNNTs.

  7. Failure mode prediction for composite structural insulated panels with MgO board facings

    Science.gov (United States)

    Smakosz, Łukasz; Kreja, Ireneusz

    2018-01-01

    Sandwich panels are readily used in civil engineering due to their high strength to weight ratio and the ease and speed of assembly. The idea of a sandwich section is to combine thin and durable facings with a light-weight core and the choice of materials used allows obtaining the desired behaviour. Panels in consideration consist of MgO (magnesium oxide) board facings and expanded polystyrene core and are characterized by immunity to biological corrosion, a high thermal insulation and a relatively low impact on environment. Customizing the range of panels to meet market needs requires frequent size changes, leading to different failure modes, which are identified in a series of costly full-scale laboratory tests. A nonlinear numerical model was created with a use of a commercial ABAQUS code and a user-defined procedure, which is able to reproduce observed failure mechanisms; its parameters were established on the basis of small-scale tests and numerical experiments. The model was validated by a comparison with the results of the full-scale bending and compression tests. The results obtained were in satisfactory agreement with the test data.

  8. Lack of current implantable cardioverter defibrillator guidelines application for primary prevention of sudden cardiac death in Latin American patients with heart failure: a cross-sectional study.

    Science.gov (United States)

    Gonzalez-Zuelgaray, Jorge; Pellizon, Oscar; Muratore, Claudio A; Oropeza, Elsa Silva; Rabinovich, Rafael; Ramos, José Luis; Tentori, Maria Cristina; Reyes, Nicolás; Aguayo, Rubén; Marin, Jorge; Peterson, Brett J

    2013-02-01

    This cross-sectional study evaluated the application of accepted international implantable cardioverter defibrillator (ICD) guidelines for primary prevention of sudden cardiac death in patients with heart failure. The PLASMA (Probabilidad de Sufrir Muerte Arritmica) study was designed to characterize management of cardiac patients in Latin America. Twelve centres included 1958 consecutively admitted patients in cardiology units in 2008 and 2009. Discharged patients were evaluated for primary prevention, ICD indication and prescription by general cardiologists. Of 1711 discharged patients, 1525 (89%) had data available for evaluating indication status. Class I indications for ICD therapy were met for 153 (10%) patients based on collected data. Only 20 (13%, 95% confidence interval: 7.7-18.4%) patients with indication were prescribed an ICD. Patients prescribed an ICD were younger than patients who were not prescribed an ICD (62 vs. 68 years, P Latin America, international guidelines for primary prevention ICD implantation are not well followed. The main reason is that cardiologists believe that patients do not meet indication criteria, even though study data confirm that criteria are met. This poses a significant challenge and underlines the importance of continuous and improved medical education.

  9. [Individuals, structures, and risks: an overview of primary HIV prevention in Portugal].

    Science.gov (United States)

    Sacramento, Octávio

    2016-06-20

    This article debates the principal guidelines and procedures that shape HIV/AIDS prevention in Portugal, focusing on risk reduction in the two major scenarios for spread of the epidemic: sexuality and injection drug use. The analysis views the risks of infection as expressions of practices that are densely interwoven into social structures and cultural frameworks. Based on this conception, the article seeks to evaluate and understand the extent to which preventive strategies take a broad and integrative underlying approach by including individuals and their circumstances. Meanwhile, the study identifies some of the main structural constraints impeding the achievement of more favorable conditions for minimizing risks and adopting safe behaviors. These analytical exercises include not only policy and program guidelines, but also processes in daily reality, showing how the non-implementation of measures already guaranteed by law poses powerful structural barriers to HIV prevention.

  10. 3D Detection, Quantification and Correlation of Slope Failures with Geologic Structure in the Mont Blanc massif

    Science.gov (United States)

    Allan, Mark; Dunning, Stuart; Lim, Michael; Woodward, John

    2016-04-01

    A thorough understanding of supply from landslides and knowledge of their spatial distribution is of fundamental importance to high-mountain sediment budgets. Advances in 3D data acquisition techniques are heralding new opportunities to create high-resolution topographic models to aid our understanding of landscape change through time. In this study, we use a Structure-from-Motion Multi-View Stereo (SfM-MVS) approach to detect and quantify slope failures at selected sites in the Mont Blanc massif. Past and present glaciations along with its topographical characteristics have resulted in a high rate of geomorphological activity within the range. Data for SfM-MVS processing were captured across variable temporal scales to examine short-term (daily), seasonal and annual change from terrestrial, Unmanned Aerial Vehicle (UAV) and helicopter perspectives. Variable spatial scales were also examined ranging from small focussed slopes (~0.01 km2) to large valley-scale surveys (~3 km2). Alignment and registration were conducted using a series of Ground Control Points (GCPs) across the surveyed slope at various heights and slope aspects. GCPs were also used to optimise data and reduce non-linear distortions. 3D differencing was performed using a multiscale model-to-model comparison algorithm (M3C2) which uses variable thresholding across each slope based on local surface roughness and model alignment quality. Detected change was correlated with local slope structure and 3D discontinuity analysis was undertaken using a plane-detection and clustering approach (DSE). Computation of joint spacing was performed using the classified data and normal distances. Structural analysis allowed us to assign a Slope Mass Rating (SMR) and assess the stability of each slope relative to the detected change and determine likely failure modes. We demonstrate an entirely 3D workflow which preserves the complexity of alpine slope topography to compute volumetric loss using a variable threshold. A

  11. THE STUDY ON THE DURABILITY OF SUBMERGED STRUCTURE DISPLACEMENT DUE TO CONCRETE FAILURE

    Directory of Open Access Journals (Sweden)

    M. Mohd

    2016-09-01

    Full Text Available Concrete structures that exposed to marine environments are subjected to multiple deterioration mechanisms. An overview of the existing technology for submerged concrete, pressure resistant, concrete structures which related such as cracks, debonds, and delamination are discussed. Basic knowledge related to drowning durability such as submerged concrete structures in the maritime environment are the durability of a concrete and the ability to resist to weathering, chemical attack, abrasion or other deterioration processes. The measuring techniques and instrumentation for geometrical monitoring of submerged structural displacements have traditionally been categorized into two groups according to the two main groups, namely as geodetic surveying and geotechnical structural measurements of local displacements. This paper aims to study the durability of submerged concrete displacement and harmful effects of submerged concrete structures.

  12. Perioperative glucocorticoid administration for prevention of systemic organ failure in patients undergoing esophageal resection for esophageal carcinoma

    Directory of Open Access Journals (Sweden)

    Antônio Marcos Raimondi

    Full Text Available CONTEXT AND OBJECTIVE: Preoperative glucocorticoid administration has been proposed for reducing postoperative morbidity. This is not widely used before esophageal resection because of incomplete knowledge regarding its effectiveness. The aim here was to assess the effects of preoperative glucocorticoid administration in adults undergoing esophageal resection for esophageal carcinoma. SEARCH STRATEGY: Studies were identified by searching the Cochrane Controlled Trials Register, MEDLINE, EMBASE, Cancer Lit, SCIELO and Cochrane Library, and by manual searching from relevant articles. The last search for clinical trials for this systematic review was performed in December 2004. SELECTION CRITERIA: This review included randomized studies of patients with potentially resectable carcinomas of the esophagus that compared preoperative glucocorticoid administration with placebo. DATA COLLECTION AND ANALYSIS: Data were extracted by the same reviewers, and the trial quality was assessed using Jadad scoring. Relative risk and weighted mean difference with 95% confidence limits were used to assess the significance of the difference between the treatment arms. RESULTS: Four randomized trials involving 146 patients were found. There were no differences in postoperative mortality, sepsis, anastomotic leakage, hepatic and renal failure between the glucocorticoid and placebo groups. There were fewer postoperative respiratory complications (p = 0.005 and multiple postoperative complications (p = 0.004 and lower postoperative plasma interleukin-6 levels (p = 0.00001 with preoperative glucocorticoid administration. There was a higher postoperative PaO2/FiO2 ratio (p = 0.0001 with preoperative glucocorticoid administration. CONCLUSION: Prophylactic administration of glucocorticoids is associated with decreased postoperative complications.

  13. Use of nitroglycerin by bolus prevents intensive care unit admission in patients with acute hypertensive heart failure.

    Science.gov (United States)

    Wilson, Suprat Saely; Kwiatkowski, Gregory M; Millis, Scott R; Purakal, John D; Mahajan, Arushi P; Levy, Phillip D

    2017-01-01

    The purpose of this study was to compare health care resource utilization among patients who were given intravenous nitroglycerin for acute heart failure (AHF) in the emergency department (ED) by intermittent bolus, continuous infusion, or a combination of both. We retrospectively identified 395 patients that received nitroglycerin therapy in the ED for the treatment of AHF over a 5-year period. Patients that received intermittent bolus (n=124) were compared with continuous infusion therapy (n=182) and combination therapy of bolus and infusion (n=89). The primary outcomes were the frequency of intensive care unit (ICU) admission and hospital length of stay (LOS). On unadjusted analysis, rates of ICU admission were significantly lower in the bolus vs infusion and combination groups (48.4% vs 68.7% vs 83%, respectively; PICU admission rate remained, and hospital LOS was 1.9 days shorter compared with infusion therapy alone. Use of intubation (bolus [8.9%] vs infusion [8.8%] vs combination [16.9%]; P=.096) and bilevel positive airway pressure (bolus [26.6%] vs infusion [20.3%] vs combination [29.2%]; P=.21) were similar as was the incidence of hypotension, myocardial injury, and worsening renal function. In ED patients with AHF, intravenous nitroglycerin by intermittent bolus was associated with a lower ICU admission rate and a shorter hospital LOS compared with continuous infusion. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Advanced Materials and Process Technology for Mechanical Failure Prevention (Proceedings of the Meeting of the Mechanical Failures Prevention Group (48th) Held in Wakefield, Massachusetts on 19-21 April 1994,

    Science.gov (United States)

    1994-04-21

    02172-0001 Stress Technology, Inc. 1800 Brighton- Henrietta Town Line Road Ex-Officlu Rochester, NY 14623 Paul L. Howaid Paul Howard Enterprises...eigenstructure) to analytical vibrational behavior. Lack of agreement indicates the need for model improvem%.nt. Use of time-domain behavior was also investigated...popularity. The primary reasons for this are: i) the lack of dependence on complex analytical models of the structural system and ii) the ability to lear on

  15. Structured chronic primary care and health-related quality of life in chronic heart failure.

    NARCIS (Netherlands)

    Bosch, M.C.; Weijden, G.D.E.M. van der; Grol, R.P.T.M.; Schers, H.J.; Akkermans, R.P.; Niessen, L.; Wensing, M.J.P.

    2009-01-01

    BACKGROUND: Structured care is proposed as a lever for improving care for patients with chronic conditions. The purpose of this study was to explore the associations of structured care characteristics, derived from the Chronic Care Model, with health-related quality of life (HRQOL) and optimal

  16. Failure Analysis

    International Nuclear Information System (INIS)

    Iorio, A.F.; Crespi, J.C.

    1987-01-01

    After ten years of operation at the Atucha I Nuclear Power Station a gear belonging to a pressurized heavy water reactor refuelling machine, failed. The gear box was used to operate the inlet-outlet heavy-water valve of the machine. Visual examination of the gear device showed an absence of lubricant and that several gear teeth were broken at the root. Motion was transmitted with a speed-reducing device with controlled adjustable times in order to produce a proper fitness of the valve closure. The aim of this paper is to discuss the results of the gear failure analysis in order to recommend the proper solution to prevent further failures. (Author)

  17. [A Structural Equation Model of Pressure Ulcer Prevention Action in Clinical Nurses].

    Science.gov (United States)

    Lee, Sook Ja; Park, Ok Kyoung; Park, Mi Yeon

    2016-08-01

    The purpose of this study was to construct and test a structural equation model for pressure ulcer prevention action by clinical nurses. The Health Belief Model and the Theory of Planned Behavior were used as the basis for the study. A structured questionnaire was completed by 251 clinical nurses to analyze the relationships between concepts of perceived benefits, perceived barriers, attitude, subjective norm, perceived control, intention to perform action and behavior. SPSS 22.0 and AMOS 22.0 programs were used to analyze the efficiency of the hypothesized model and calculate the direct and indirect effects of factors affecting pressure ulcer prevention action among clinical nurses. The model fitness statistics of the hypothetical model fitted to the recommended levels. Attitude, subjective norm and perceived control on pressure ulcer prevention action explained 64.2% for intention to perform prevention action. The major findings of this study indicate that it is essential to recognize improvement in positive attitude for pressure ulcer prevention action and a need for systematic education programs to increase perceived control for prevention action.

  18. Role of electrocardiography and echocardiography in prevention and predicting outcome of subjects at increased risk of heart failure.

    Science.gov (United States)

    Di Bello, Vitantonio; La Carrubba, Salvatore; Antonini-Canterin, Francesco; Di Salvo, Giovanni; Caso, Pio; La Canna, Giovanni; Erlicher, Andrea; Badano, Luigi; Romano, Maria Francesca; Zito, Concetta; Vriz, Olga; Conte, Lorenzo; Carerj, Scipione

    2015-02-01

    Asymptomatic left ventricular dysfunction (ALVD) is relatively common in both community and high-risk populations. Early pharmacological intervention can improve clinical outcomes in subjects with this condition. This multicentre study consists on electrocardiographic and echocardiographic examination of stage A and B heart failure (HF) asymptomatic subjects with one or more cardiovascular risk factors, to assess the prognostic value of cardiovascular risk factors per se, clinical history, and electrocardiographic and echocardiographic parameters in prediction of progression of HF and/or in development of cardiovascular primary or secondary events. A total of 2142 asymptomatic subjects (mean age 63 years, 1162 males) performed an electrocardiographic and echocardiographic examination. Electrocardiogram (ECG) pathological signs according to Minnesota code and left ventricular dysfunction both systolic and diastolic by echocardiography were evaluated. There were 2002 subjects who were followed up for 26 ± 11 months, observing their primary and secondary end points. At follow up, the study population presented 111 primary end points (5.2%) and 441 secondary end points (20.6%). ECG criteria of LV hypertrophy and signs of ischaemia or previous myocardial infarction (p < 0.0001) were highly significantly related to primary end points. Both ECG and echocardiography (systolic function) are able at Kaplan-Meier cumulative survival curves to predict primary end points (p < 0.0001). Presence or absence of left ventricular systolic and /or diastolic dysfunction has an incremental value in comparison to cardiovascular risk factors, clinical history, and ECG findings to predict both the evolution towards a more severe HF stage (stage C) and also the occurrence of cardiovascular events. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  19. Role of Biomarkers for the Prevention, Assessment, and Management of Heart Failure: A Scientific Statement From the American Heart Association.

    Science.gov (United States)

    Chow, Sheryl L; Maisel, Alan S; Anand, Inder; Bozkurt, Biykem; de Boer, Rudolf A; Felker, G Michael; Fonarow, Gregg C; Greenberg, Barry; Januzzi, James L; Kiernan, Michael S; Liu, Peter P; Wang, Thomas J; Yancy, Clyde W; Zile, Michael R

    2017-05-30

    Natriuretic peptides have led the way as a diagnostic and prognostic tool for the diagnosis and management of heart failure (HF). More recent evidence suggests that natriuretic peptides along with the next generation of biomarkers may provide added value to medical management, which could potentially lower risk of mortality and readmissions. The purpose of this scientific statement is to summarize the existing literature and to provide guidance for the utility of currently available biomarkers. The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through December 2016. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or contemporary clinical practice recommendations. A number of biomarkers associated with HF are well recognized, and measuring their concentrations in circulation can be a convenient and noninvasive approach to provide important information about disease severity and helps in the detection, diagnosis, prognosis, and management of HF. These include natriuretic peptides, soluble suppressor of tumorgenicity 2, highly sensitive troponin, galectin-3, midregional proadrenomedullin, cystatin-C, interleukin-6, procalcitonin, and others. There is a need to further evaluate existing and novel markers for guiding therapy and to summarize their data in a standardized format to improve communication among researchers and practitioners. HF is a complex syndrome involving diverse pathways and pathological processes that can manifest in circulation as biomarkers. A number of such biomarkers are now clinically available, and monitoring their

  20. Tissue factor pathway inhibitor prevents airway obstruction, respiratory failure and death due to sulfur mustard analog inhalation

    Energy Technology Data Exchange (ETDEWEB)

    Rancourt, Raymond C., E-mail: raymond.rancourt@ucdenver.edu; Veress, Livia A., E-mail: livia.veress@ucdenver.edu; Ahmad, Aftab, E-mail: aftab.ahmad@ucdenver.edu; Hendry-Hofer, Tara B., E-mail: tara.hendry-hofer@ucdenver.edu; Rioux, Jacqueline S., E-mail: jacqueline.rioux@ucdenver.edu; Garlick, Rhonda B., E-mail: rhonda.garlick@ucdenver.edu; White, Carl W., E-mail: carl.w.white@ucdenver.edu

    2013-10-01

    Sulfur mustard (SM) inhalation causes airway injury, with enhanced vascular permeability, coagulation, and airway obstruction. The objective of this study was to determine whether recombinant tissue factor pathway inhibitor (TFPI) could inhibit this pathogenic sequence. Methods: Rats were exposed to the SM analog 2-chloroethyl ethyl sulfide (CEES) via nose-only aerosol inhalation. One hour later, TFPI (1.5 mg/kg) in vehicle, or vehicle alone, was instilled into the trachea. Arterial O{sub 2} saturation was monitored using pulse oximetry. Twelve hours after exposure, animals were euthanized and bronchoalveolar lavage fluid (BALF) and plasma were analyzed for prothrombin, thrombin–antithrombin complex (TAT), active plasminogen activator inhibitor-1 (PAI-1) levels, and fluid fibrinolytic capacity. Lung steady-state PAI-1 mRNA was measured by RT-PCR analysis. Airway-capillary leak was estimated by BALF protein and IgM, and by pleural fluid measurement. In additional animals, airway cast formation was assessed by microdissection and immunohistochemical detection of airway fibrin. Results: Airway obstruction in the form of fibrin-containing casts was evident in central conducting airways of rats receiving CEES. TFPI decreased cast formation, and limited severe hypoxemia. Findings of reduced prothrombin consumption, and lower TAT complexes in BALF, demonstrated that TFPI acted to limit thrombin activation in airways. TFPI, however, did not appreciably affect CEES-induced airway protein leak, PAI-1 mRNA induction, or inhibition of the fibrinolytic activity present in airway surface liquid. Conclusions: Intratracheal administration of TFPI limits airway obstruction, improves gas exchange, and prevents mortality in rats with sulfur mustard-analog-induced acute lung injury. - Highlights: • TFPI administration to rats after mustard inhalation reduces airway cast formation. • Inhibition of thrombin activation is the likely mechanism for limiting casts. • Rats given TFPI

  1. Tissue factor pathway inhibitor prevents airway obstruction, respiratory failure and death due to sulfur mustard analog inhalation

    International Nuclear Information System (INIS)

    Rancourt, Raymond C.; Veress, Livia A.; Ahmad, Aftab; Hendry-Hofer, Tara B.; Rioux, Jacqueline S.; Garlick, Rhonda B.; White, Carl W.

    2013-01-01

    Sulfur mustard (SM) inhalation causes airway injury, with enhanced vascular permeability, coagulation, and airway obstruction. The objective of this study was to determine whether recombinant tissue factor pathway inhibitor (TFPI) could inhibit this pathogenic sequence. Methods: Rats were exposed to the SM analog 2-chloroethyl ethyl sulfide (CEES) via nose-only aerosol inhalation. One hour later, TFPI (1.5 mg/kg) in vehicle, or vehicle alone, was instilled into the trachea. Arterial O 2 saturation was monitored using pulse oximetry. Twelve hours after exposure, animals were euthanized and bronchoalveolar lavage fluid (BALF) and plasma were analyzed for prothrombin, thrombin–antithrombin complex (TAT), active plasminogen activator inhibitor-1 (PAI-1) levels, and fluid fibrinolytic capacity. Lung steady-state PAI-1 mRNA was measured by RT-PCR analysis. Airway-capillary leak was estimated by BALF protein and IgM, and by pleural fluid measurement. In additional animals, airway cast formation was assessed by microdissection and immunohistochemical detection of airway fibrin. Results: Airway obstruction in the form of fibrin-containing casts was evident in central conducting airways of rats receiving CEES. TFPI decreased cast formation, and limited severe hypoxemia. Findings of reduced prothrombin consumption, and lower TAT complexes in BALF, demonstrated that TFPI acted to limit thrombin activation in airways. TFPI, however, did not appreciably affect CEES-induced airway protein leak, PAI-1 mRNA induction, or inhibition of the fibrinolytic activity present in airway surface liquid. Conclusions: Intratracheal administration of TFPI limits airway obstruction, improves gas exchange, and prevents mortality in rats with sulfur mustard-analog-induced acute lung injury. - Highlights: • TFPI administration to rats after mustard inhalation reduces airway cast formation. • Inhibition of thrombin activation is the likely mechanism for limiting casts. • Rats given TFPI had

  2. Prevention of brittle fracture of steel structures by controlling the local stress and strain fields

    Directory of Open Access Journals (Sweden)

    Moyseychik Evgeniy Alekseevich

    Full Text Available In the article the author offers a classification of the methods to increase the cold resistance of steel structural shapes with a focus on the regulation of local fields of internal stresses and strains to prevent brittle fracture of steel structures. The need of a computer thermography is highlighted not only for visualization of temperature fields on the surface, but also to control the fields of residual stresses and strains in a controlled element.

  3. Influence of Professional Preparation and Class Structure on HIV, STD, and Pregnancy Prevention Education

    Science.gov (United States)

    Rhodes, Darson L.; Jozkowski, Kristen N.; Hammig, Bart J.; Ogletree, Roberta J.; Fogarty, Erin C.

    2014-01-01

    Objective: The purpose of this study was to determine if education about human immunodeficiency virus (HIV)/sexually transmitted disease (STD) and pregnancy prevention is dependent on professional preparation and/or class structure. Design: A secondary data analysis of the 2006 School Health Policies and Programmes Study (SHPPS) was conducted.…

  4. Structural myocardial changes in chronic heart failure of II functional class based on overweight and abdominal obesity

    Directory of Open Access Journals (Sweden)

    V. Z. Netyazhenko

    2014-04-01

    Full Text Available Abstract. 153 patients with CHF of II functional class, with normal weight, overweight and abdominal obesity I-III degrees Examined. Studied structural myocardial changes at CHF depending on the degree of excess weight. Structural changes of the heart, the extent and type of myocardial hypertrophy of left ventricle depending on the availability of overweight and obesity were revealed. Actuality. Chronic heart failure (CHF is characterized by a high mortality rate and frequency of hospitalization of patients, a significant decline in their quality of life and significant financial burden. CHF is a medical and social problem that a certain dominant in the near future all over the world, because the average life expectancy of patients with the diagnosis ranges from 1,7 to 7 years and the long-term observation is evidence of the increased risk of death, that 5 year more than four times the initial value. The main etiological factors of occurrence, progression and adverse exit of CHF are age, coronary heart disease (CHD, arterial hypertension, valvular heart disease, diabetes and obesity. In general, structural changes of heart in obesity can be divided into the following main components: left ventricle hypertrophy, changes in the structural composition of cardiac tissue, heart obesity, change of the sizes of the right ventricle and left atrium (PL, valvular heart disease. Research objective: to establish the structural changes of CHF of II functional class depending on the availability of overweight and abdominal type of obesity various degrees. Material and methods: 153 patients with CHF of II functional class were examined. Etiological factors of development CHF were hypertensive disease, chronic forms of CAD and the combination of these pathologies. The diagnosis of CHF installed according to WHO criteria, the European society of cardiology and the Association of cardiologists of Ukraine, and classified according to functional classification of

  5. Editorial: Introduction to the Special Issue ;Slope Tectonics: Inherited Structures, Morphology of Deformation and Catastrophic Failure;

    Science.gov (United States)

    Hermanns, R. L.; Oppikofer, T.; Jaboyedoff, M.; Clague, J. J.; Scarascia-Mugnozza, G.

    2017-07-01

    The "Conference on Slope Tectonics" has become an international scientific meeting point to present and discuss a variety of topics related to slope deformation and the deposits of related failures. The first conference took place on February 15-16, 2008 at University of Lausanne (Switzerland). It was followed by a second conference on September 6-10, 2011, in Austria (organized by the Geological Survey of Austria) and a third on September 8-12, 2014, in Norway (organized by the Geological Survey of Norway). The two later events included field trips. It has become a tradition that selected papers from these conference are published - papers from the first conference were published by the Geological Society as Special Publication 351 (Jaboyedoff, 2011), and those from the second conference were published in a special issue of Tectonophysics (Baron and Jaboyedoff, 2013). This special issue of Geomorphology is a collection of papers presented at the Norwegian Conference on Slope Tectonics. This collection of papers focuses on the role of tectonics in gravitationally induced rock-slope instabilities. The slopes either deform over long periods as deep-seated gravitational slope deformation (DSGSD) or more rapidly as rockslides or rock avalanches. The reconstruction of slope deformation is an integral part of the studies captured in this special issue.

  6. Structural and functional changes of the heart in patients with chronic ischemic heart failure, associated with renal dysfunction

    Directory of Open Access Journals (Sweden)

    D. A. Lashkul

    2014-04-01

    Full Text Available Kidney disease is a frequent complication of congestive heart failure (CHF and may contribute to the progression of ventricular dysfunction. Regardless of the degree of heart failure, chronic kidney disease (CKD increases the risk of death and cardiac decompensation. Left ventricular hypertrophy (LVH is a known parameter of cardiac remodelling and has a higher prevalence and incidence among people with impaired kidney function. LVH is an early subclinical marker of cardiovascular disease and heart failure risk, and is probably an intermediary step in the pathway leading from kidney dysfunction to heart failure and its complications. The effects of CKD on other left ventricular and myocardial parameters, however, have been less characterized. The aim of the study was to examine the structural and functional changes, geometric remodeling of the heart in patients with ischemic chronic heart failure, being hospitalized, according to the presence of renal dysfunction. Materials and methods. The study involved 333 patients with ischemic CHF (277 men and 56 women, mean age 59,3±9,4 years. The functional class of heart failure was assessed on the recommendations of the New York Heart Association (NYHA. The etiology of heart failure in 288 (86.5% patients had a combination of coronary artery disease and essential hypertension, in 45 (13.5% – only CAD. 1 FC of heart failure was diagnosed in 9 (2.7% patients, 2 FC - in 106 (31.8%, 3 FC - in 199 (59.8% and 4 FC - 19 (5.7% patients. Diabetes was in 61 (18.3%, myocardial infarction history was in 240 (72.1% patients. Depending on the glomerular filtration rate, patients were divided into 3 groups: 72 with normal GFR (>90 ml/min/1.73m2, 218 with a slight decrease in GFR (60-90 ml/min/1.73m2 and 43 with moderate reduced GFR (<60 ml/min/1.73m2. Echocardiography was performed using the General Electric VIVID 3 system (General Electric Healthcare, USA with the 2.5–3.5 MHz transducer and Doppler technique

  7. Pretreatment of Sialic Acid Efficiently Prevents Lipopolysaccharide-Induced Acute Renal Failure and Suppresses TLR4/gp91-Mediated Apoptotic Signaling

    Directory of Open Access Journals (Sweden)

    Shih-Ping Hsu

    2016-05-01

    Full Text Available Background/Aims: Lipopolysaccharides (LPS binding to Toll-like receptor 4 (TLR4 activate NADPH oxidase gp91 subunit-mediated inflammation and oxidative damage. Recognizing the high binding affinity of sialic acid (SA with LPS, we further explored the preventive potential of SA pretreatment on LPS-evoked acute renal failure (ARF. Methods: We determined the effect of intravenous SA 30 min before LPS-induced injury in urethane-anesthetized female Wistar rats by evaluating kidney reactive oxygen species (ROS responses, renal and systemic hemodynamics, renal function, histopathology, and molecular mechanisms. Results: LPS time-dependently reduced arterial blood pressure, renal microcirculation, and increased blood urea nitrogen and creatinine in the rats. LPS enhanced monocyte/macrophage infiltration and ROS production, and subsequently impaired kidneys with the enhancement of TLR4/NADPH oxidase gp91/Caspase 3/poly-(ADP-ribose-polymerase (PARP-mediated apoptosis in the kidneys. SA pretreatment effectively alleviated LPS-induced ARF. The levels of LPS-increased ED-1 infiltration and ROS production in the kidney were significantly depressed by SA pretreatment. Furthermore, SA pretreatment significantly depressed TLR4 activation, gp91 expression, and Caspase 3/PARP induced apoptosis in the kidneys. Conclusion: We suggest that pretreatment of SA significantly and preventively attenuated LPS-induced detrimental effects on systemic and renal hemodynamics, renal ROS production and renal function, as well as, LPS-activated TLR4/gp91/Caspase3 mediated apoptosis signaling.

  8. Structural Failure Sites in Anterior Vaginal Wall Prolapse: Identification of a Collinear Triad.

    Science.gov (United States)

    Chen, Luyun; Lisse, Sean; Larson, Kindra; Berger, Mitchell B; Ashton-Miller, James A; DeLancey, John O L

    2016-10-01

    To test the null hypothesis that six factors representing potential fascial and muscular failure sites contribute equally to the presence and size of a cystocele: two vaginal attachment factors (apical support and paravaginal defects), two vaginal wall factors (vaginal length and width), and two levator ani factors (hiatus size and levator ani defects). Thirty women with anterior-predominant prolapse (women in a case group) and 30 women in a control group underwent three-dimensional stress magnetic resonance imaging. The location of the anterior vaginal wall at maximal Valsalva was identified with the modified Pelvic Inclination Coordinate System and the six factors measured. Analysis included repeated-measure analysis of variance, logistic regression, and stepwise linear regression. We identified a collinear triad consisting of apical location, paravaginal location, and hiatus size that were not only the strongest predictors of cystocele size, but were also highly correlated with one another (r=0.84-0.89, P<.001) for the presence and size of the prolapse. Together they explain up to 83% of the variation in cystocele size. Among the less significant vaginal factors, vaginal length explained 19% of the variation in cystocele size, but no significant difference in vaginal width existed. Women in the case group were more likely to have abnormalities in collinear triad factors (up to 80%) than vaginal wall factors (up to 23.3%). Combining the strongest collinear triad with the vaginal factors, the model explained 92.5% of the variation in cystocele size. Apical location, paravaginal location, and hiatus size are highly correlated and are strong predictors of cystocele presence and size.

  9. Evaluating stress analysis and failure criteria for offshore structures for Pechora Sea conditions

    Science.gov (United States)

    Nesic, S.; Donskoy, Y.; Zolotukhin, A.

    2017-12-01

    Development of Arctic hydrocarbon resources has faced many challenges due to sensitive environmental conditions including low temperatures, ice cover and terrestrial permafrost and extreme seasonal variation in sunlight. Russian offshore field development in Arctic region is usually associated with annual ice cover, which can cause serious damage on the offshore platforms. The Pechora Sea has claimed as one of the most perspective oil and gas region of the Russian Arctic with seven discovered oil and gas fields and several dozens of structures. Our rough assessment, based on in-place hydrocarbon volumes and recovery factor evaluation concept, indicates that Pechora Sea alone has in-place volumes amounting to ca. 20 billion barrel oil equivalent (BOE). This quantity is enough to secure produced volumes by 2040 exceeding 3 billion BOE [1] that indicates huge resource potential of the region. The environmental conditions are primarily function of water dynamics and ice cover. The sea is covered by the ice for greatest part of the year. In this article, the ice load simulations were performed using explicit dynamic analysis system in ANSYS software to determine best shape and size of an offshore platform for the Pechora Sea ice conditions. Different gravity based structures (GBS) were analyzed: artificial island, hollow cylindrical and conical concrete structures and four-leg GBS. Relationships between the stress, deformations and time were analyzed and important observations from the simulation results were a basis for selecting the most preferable structures.

  10. Tissue factor pathway inhibitor prevents airway obstruction, respiratory failure and death due to sulfur mustard analog inhalation

    Science.gov (United States)

    Rancourt, Raymond C.; Veress, Livia A.; Ahmad, Aftab; Hendry-Hofer, Tara B.; Rioux, Jacqueline S.; Garlick, Rhonda B.; White, Carl W.

    2013-01-01

    Sulfur mustard (SM) inhalation causes airway injury, with enhanced vascular permeability, coagulation, and airway obstruction. The objective of this study was to determine whether recombinant tissue factor pathway inhibitor (TFPI) could inhibit this pathogenic sequence. Methods Rats were exposed to the SM analog 2-chloroethyl ethyl sulfide (CEES) via nose-only aerosol inhalation. One hour later, TFPI (1.5 mg/kg) in vehicle, or vehicle alone, were instilled into the trachea. Arterial O2 saturation was monitored using pulse oximetry. Twelve hours after exposure, animals were euthanized and bronchoalveolar lavage fluid (BALF) and plasma analyzed for prothrombin, thrombin-antithrombin complex (TAT), active plasminogen activator inhibitor-1 (PAI-1) levels, and fluid fibrinolytic capacity. Lung steady-state PAI-1 mRNA was measured by RT-PCR analysis. Airway-capillary leak was estimated by BALF protein and IgM, and by pleural fluid measurement. In additional animals, airway cast formation was assessed by microdissection and immunohistochemical detection of airway fibrin. Results Airway obstruction in the form of fibrin-containing casts were evident in central conducting airways of rats receiving CEES. TFPI decreased cast formation, and limited severe hypoxemia. Findings of reduced prothrombin consumption, and lower TAT complexes in BALF, demonstrated that TFPI acted to limit thrombin activation in airways. TFPI, however, did not appreciably affect CEES-induced airway protein leak, PAI-1 mRNA induction, or inhibition of the fibrinolytic activity present in airway surface liquid. Conclusions Intratracheal administration of TFPI limits airway obstruction, improves gas exchange, and prevents mortality in rats with sulfur mustard-analog-induced acute lung injury. PMID:23727623

  11. IP3 3-kinase B controls hematopoietic stem cell homeostasis and prevents lethal hematopoietic failure in mice

    Science.gov (United States)

    Siegemund, Sabine; Rigaud, Stephanie; Conche, Claire; Broaten, Blake; Schaffer, Lana; Westernberg, Luise; Head, Steven Robert

    2015-01-01

    Tight regulation of hematopoietic stem cell (HSC) homeostasis ensures lifelong hematopoiesis and prevents blood cancers. The mechanisms balancing HSC quiescence with expansion and differentiation into hematopoietic progenitors are incompletely understood. Here, we identify Inositol-trisphosphate 3-kinase B (Itpkb) as an essential regulator of HSC homeostasis. Young Itpkb−/− mice accumulated phenotypic HSC, which were less quiescent and proliferated more than wild-type (WT) controls. Itpkb−/− HSC downregulated quiescence and stemness associated, but upregulated activation, oxidative metabolism, protein synthesis, and lineage associated messenger RNAs. Although they had normal-to-elevated viability and no significant homing defects, Itpkb−/− HSC had a severely reduced competitive long-term repopulating potential. Aging Itpkb−/− mice lost hematopoietic stem and progenitor cells and died with severe anemia. WT HSC normally repopulated Itpkb−/− hosts, indicating an HSC-intrinsic Itpkb requirement. Itpkb−/− HSC showed reduced colony-forming activity and increased stem-cell-factor activation of the phosphoinositide-3-kinase (PI3K) effectors Akt/mammalian/mechanistic target of rapamycin (mTOR). This was reversed by treatment with the Itpkb product and PI3K/Akt antagonist IP4. Transcriptome changes and biochemistry support mTOR hyperactivity in Itpkb−/− HSC. Treatment with the mTOR-inhibitor rapamycin reversed the excessive mTOR signaling and hyperproliferation of Itpkb−/− HSC without rescuing colony forming activity. Thus, we propose that Itpkb ensures HSC quiescence and function through limiting cytokine-induced PI3K/mTOR signaling and other mechanisms. PMID:25788703

  12. Recreation of Small Strains Phenomenon under Pavement Structure and Consequences of Failure to Address It

    Science.gov (United States)

    Fedorowicz, Lidia; Kadela, Marta

    2017-10-01

    This paper describes the small strains phenomenon which occurs in the subgrade under a pavement, a phenomenon documented through in-situ tests and recreated in numerical analyses, which lends a practical engineering aspect to the subject matter. The analyses were preceded by: 1) presentation of the role of constitutive models in structure-subgrade system analysis, 2) reference to methods of modelling in mechanistic procedures and possibility of reliable assessment of criterial values in road structures. These studies were coupled with a description of field tests, which recorded strains in subgrade under a loaded pavement: in zone I directly under the pavement – variable, depending on stiffness of the pavement and the load (about 200÷1000.10-6) and below that, in zone II – ‘stabilised’ (about 1÷5.10-6). In summary, it has been found that the accuracy of numerical analyses of structure-subgrade systems is dependent on the adopted constitutive model of the soil and the numerical calculation area representing the subgrade. Recreation and analysis of the pavement-subgrade system behaviour employed the MCC(OC) critical state model. It was determined that a reliable response of the computational model to the load path used can be obtained with a model that has been previously properly calibrated. The paper justifies the need to carry out further, directed field tests, coupled with numerical analyses employing relevant constitutive models for description of the soil’s performance.

  13. Failure of structural elements made of polymer supported composite materials during the multiyear natural aging

    Science.gov (United States)

    Blinkov, Pavel; Ogorodov, Leonid; Grabovyy, Peter

    2018-03-01

    Modern high-rise construction introduces a number of limitations and tasks. In addition to durability, comfort and profitability, projects should take into account energy efficiency and environmental problems. Polymer building materials are used as substitutes for materials such as brick, concrete, metal, wood and glass, and in addition to traditional materials. Plastic materials are light, can be formed into complex shapes, durable and low, and also possess a wide range of properties. Plastic materials are available in various forms, colors and textures and require minimal or no color. They are resistant to heat transfer and diffusion of moisture and do not suffer from metal corrosion or microbial attack. Polymeric materials, including thermoplastics, thermoset materials and wood-polymer composites, have many structural and non-structural applications in the construction industry. They provide unique and innovative solutions at a low cost, and their use is likely to grow in the future. A number of polymer composite materials form complex material compositions, which are applied in the construction in order to analyze the processes of damage accumulation under the conditions of complex nonstationary loading modes, and to determine the life of structural elements considering the material aging. This paper present the results of tests on short-term compression loading with a deformation rate of v = 2 mm/min using composite samples of various shapes and sizes.

  14. Failure of structural elements made of polymer supported composite materials during the multiyear natural aging

    Directory of Open Access Journals (Sweden)

    Blinkov Pavel

    2018-01-01

    Full Text Available Modern high-rise construction introduces a number of limitations and tasks. In addition to durability, comfort and profitability, projects should take into account energy efficiency and environmental problems. Polymer building materials are used as substitutes for materials such as brick, concrete, metal, wood and glass, and in addition to traditional materials. Plastic materials are light, can be formed into complex shapes, durable and low, and also possess a wide range of properties. Plastic materials are available in various forms, colors and textures and require minimal or no color. They are resistant to heat transfer and diffusion of moisture and do not suffer from metal corrosion or microbial attack. Polymeric materials, including thermoplastics, thermoset materials and wood-polymer composites, have many structural and non-structural applications in the construction industry. They provide unique and innovative solutions at a low cost, and their use is likely to grow in the future. A number of polymer composite materials form complex material compositions, which are applied in the construction in order to analyze the processes of damage accumulation under the conditions of complex nonstationary loading modes, and to determine the life of structural elements considering the material aging. This paper present the results of tests on short-term compression loading with a deformation rate of v = 2 mm/min using composite samples of various shapes and sizes.

  15. Accounting for Uncertainty in Decision Analytic Models Using Rank Preserving Structural Failure Time Modeling: Application to Parametric Survival Models.

    Science.gov (United States)

    Bennett, Iain; Paracha, Noman; Abrams, Keith; Ray, Joshua

    2018-01-01

    Rank Preserving Structural Failure Time models are one of the most commonly used statistical methods to adjust for treatment switching in oncology clinical trials. The method is often applied in a decision analytic model without appropriately accounting for additional uncertainty when determining the allocation of health care resources. The aim of the study is to describe novel approaches to adequately account for uncertainty when using a Rank Preserving Structural Failure Time model in a decision analytic model. Using two examples, we tested and compared the performance of the novel Test-based method with the resampling bootstrap method and with the conventional approach of no adjustment. In the first example, we simulated life expectancy using a simple decision analytic model based on a hypothetical oncology trial with treatment switching. In the second example, we applied the adjustment method on published data when no individual patient data were available. Mean estimates of overall and incremental life expectancy were similar across methods. However, the bootstrapped and test-based estimates consistently produced greater estimates of uncertainty compared with the estimate without any adjustment applied. Similar results were observed when using the test based approach on a published data showing that failing to adjust for uncertainty led to smaller confidence intervals. Both the bootstrapping and test-based approaches provide a solution to appropriately incorporate uncertainty, with the benefit that the latter can implemented by researchers in the absence of individual patient data. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  16. Correlation between intraocular pressure and the biometric structure of the anterior chamber in patients of chronic renal failure with hemodialysis

    Directory of Open Access Journals (Sweden)

    Zhi-Ying Yu

    2017-02-01

    Full Text Available AIM: To investigate the correlation between intraocular pressure(IOPchanges pre- and post-hemodialysis(HDand the biometric structure of the anterior chamber in patients of chronic renal failure. METHODS: Fifty-two patients(take right eye as study onewith hemodialysis that were diagnosed with chronic renal failure by nephrology in our hospital from January 2015 to December 2015 were collected. Fifty-two eyes were divided into four groups based on Shaffer classification combined with ultrasound biomicroscopy(UBMand gonioscopy manifestations: wide angle group, narrow angle group, extremely narrow group and close angle group. Venous blood was collected to get plasma colloid osmotic pressure before HD and within 60s after HD. IOP was measured with rebound intraocular pressure gauge in a supine positon approximately 30min before starting HD, 2h after HD begin and approximately 30min after HD ending. Approximately 30min before and after HD, central corneal thickness was measured with corneal endothelial cell counter, central anterior chamber depth and lens thickness were taken by A scan, angle opening distance, trabecular iris angle, iris thickness and ciliary body thickness were measured by UBM. RESULTS: Plasma osmotic pressure reduced after HD, the difference was statistically significant(t=3.04, PF=41.69, PPPF=6.44, PPt=2.61, PCONCLUSION: The influence of hemodialysis on IOP is related to the biometric structure of the anterior chamber. And extremely narrow angle is risk factor of elevated IOP during hemodialysis, narrow angle may be a risk factor. While patients with wide angle is relatively safe. We suggest to take ocular examination as early as possible for patients with hemodialysis, and focus on patients with narrow angle.

  17. Failure behavior of concrete pile and super-structure dynamic response as a result of soil liquefaction during earthquake

    Science.gov (United States)

    Kaneda, Shogo; Hayashi, Kazuhiro; Hachimori, Wataru; Tamura, Shuji; Saito, Taiki

    2017-10-01

    In past earthquake disasters, numerous building structure piles were damaged by soil liquefaction occurring during the earthquake. Damage to these piles, because they are underground, is difficult to find. The authors aim to develop a monitoring method of pile damage based on superstructure dynamic response. This paper investigated the relationship between the damage of large cross section cementitious piles and the dynamic response of the super structure using a centrifuge test apparatus. A dynamic specimen used simple cross section pile models consisting of aluminum rod and mortar, a saturated soil (Toyoura sand) of a relative density of 40% and a super structure model of a natural period of 0.63sec. In the shaking table test under a 50G field (length scale of 1/50), excitation was a total of 3 motions scaled from the Rinkai wave at different amplitudes. The maximum acceleration of each of the excitations was 602gal, 336gal and 299gal. The centrifuge test demonstrated the liquefaction of saturated soil and the failure behavior of piles. In the test result, the damage of piles affected the predominant period of acceleration response spectrum on the footing of the superstructure.

  18. A probabilistic physics-of-failure model for prognostic health management of structures subject to pitting and corrosion-fatigue

    International Nuclear Information System (INIS)

    Chookah, M.; Nuhi, M.; Modarres, M.

    2011-01-01

    A combined probabilistic physics-of-failure-based model for pitting and corrosion-fatigue degradation mechanisms is proposed to estimate the reliability of structures and to perform prognosis and health management. A mechanistic superposition model for corrosion-fatigue mechanism was used as a benchmark model to propose the simple model. The proposed model describes the degradation of the structures as a function of physical and critical environmental stresses, such as amplitude and frequency of mechanical loads (for example caused by the internal piping pressure) and the concentration of corrosive chemical agents. The parameters of the proposed model are represented by the probability density functions and estimated through a Bayesian approach based on the data taken from the experiments performed as part of this research. For demonstrating applications, the proposed model provides prognostic information about the reliability of aging of structures and is helpful in developing inspection and replacement strategies. - Highlights: ► We model an inventory system under static–dynamic uncertainty strategy. ► The demand is stochastic and non-stationary. ► The optimal ordering policy is proven to be a base stock policy. ► A solution algorithm for finding an optimal solution is provided. ► Two heuristics developed produce high quality solutions and scale-up efficiently.

  19. Failure Assessment

    Science.gov (United States)

    Lutz, Robyn; Nikora, Allen

    2005-01-01

    Three questions to which software developers want accurate, precise answers are "How can the software system fail?", "mat bad things will happen if the software fails?t', and "How many failures will the software experience?". Numerous techniques have been devised to answer these questions; three of the best known are: 1) Software Fault Tree Analysis (SFTA) 2) Software Failure Modes, Effects, and Criticality Analysis (SFMECA 3) Software Fault/Failure Modeling. SFTA and SFMECA have been successfully used to analyze the flight software for a number of robotic planetary exploration missions, including Galileo, Cassini, and Deep Space 1. Given the increasing interest in reusing software components from mission to mission, one of us has developed techniques for reusing the corresponding portions of the SFTA and SFMECA, reducing the effort required to conduct these analyses. SFTA has also been shown to be effective in analyzing the security aspects of software systems; intrusion mechanisms and effects can easily be modeled using these techniques. The Bi- Directional Safety Analysis (BDSA) method combines a forward search (similar to SFMECA) from potential failure modes to their effects, with a backward search (similar to SFTA) from feasible hazards to the contributing causes of each hazard. BDSA offers an efficient way to identify latent failures. Recent work has extended BDSA to product-line applications such as flight-instrumentation displays and developed tool support for the reuse of the failure-analysis artifacts within a product line. BDSA has also been streamlined to support those projects having tight cost and/or schedule constraints for their failure analysis efforts. We discuss lessons learned from practice, describe available tools, and identi@ some future directions for the topic. A substantial amount of research has been devoted to estimating the number of failures that a software system will experience during test and operations, as well as the number of

  20. Handling of the bone long pseudoarthrosis with autologo structural bone graft in failure osteosynthesis

    International Nuclear Information System (INIS)

    Satizabal Azuero, Carlos; Calderon Uribe, Oscar; Alban P, Paulo Antonio; Gamba Sanchez, Cesar Enrique

    2003-01-01

    We find in the literature that the usual way to treat pseudoarthrosis always includes the removal of the material used to stabilize the fractures, with bring along high hospital and social costs for the patient and the family. The treatment we purpose is the appliance of an autologo structural iliac bone graft, trapezoid form, throughout a minimal incision into the lesion. We treated 12 patients that included 14 long bones in a two year period, age range of 23,2 y 12 (86%) patients with femur pseudoarthrosis, 1 (7%) with tibia y 1 (7%) humerus. we obtained 100% consolidation at 5 months after surgery. no complications reported from the patients, and an important reduce in hospital and social costs

  1. The human factor as a cause of failures in building structures

    Directory of Open Access Journals (Sweden)

    Vondráčková Terezie

    2017-01-01

    Full Text Available Human error can be defined as any unintentional or inadequate decision, taken at any level in the hierarchy of an organization, which is, or was inappropriate in a given situation. Human errors can occur in all human activities across an organization - at a managerial, conceptual or technical level – in connection with mistakes in the construction project itself, mistakes made by the investor, mistakes made by those using the building, mistakes in supplier relations, mistakes in the maintenance of the structure, and others. The factors that can affect the reliability of those people making the decisions that lead to the mistakes include the quality of their education, their experience with stress, or lack thereof, as well as issues such as workload, fatigue, workplace ergonomics, working hours, social climate and private matters.

  2. Economic costs and benefits associated with investments in pollution prevention structures

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, G.S.

    1995-09-01

    Both fertilizers and pesticides are primary sources of surface and groundwater contamination in the US. The agrichemical industry came under increased pressures in the mid-1980s to implement environmentally sound management practices and to install containment structures around fertilizer and chemical storage/handling areas to prevent future contamination of existing sites or the movement of contaminants offsite. TVA`s long and successful history of technology transfer to the retail fertilizer industry, as well as the technical expertise of the Agency`s staff, made TVA ideally suited to handle the new environmental challenge. It was during this time period that TVA`s Model Site Demonstration Program (MSD) and Individual Technology Demonstration Program (ITD) were conceived. The general objective of these programs is to provide research, development, and application of pollution prevention technologies and strategies for industries which market or use fertilizers, pesticides, and other agricultural chemicals. From an economic perspective, the installation of pollution prevention structures, as well as adherence to other regulatory requirements carries a real cost to the agrichemical retailer. However, there may also be benefits tied to the adoption of new technology that would offset some or all of the additional operating costs accrued as a result of investment in the environmental technology. This paper attempts to document the economic costs associated with investments in pollution prevention technologies and adherence to environmental regulations at TVA demonstrator sites; as well as the potential benefits an agribusiness dealer may accrue as a result of the environmental investment.

  3. Long-Term Follow-up of Participants with Heart Failure in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

    Science.gov (United States)

    Piller, Linda B.; Baraniuk, Sarah; Simpson, Lara M.; Cushman, William C.; Massie, Barry M.; Einhorn, Paula T.; Oparil, Suzanne; Ford, Charles E.; Graumlich, James F.; Dart, Richard A.; Parish, David C.; Retta, Tamrat M.; Cuyjet, Aloysius B.; Jafri, Syed Z.; Furberg, Curt D.; Saklayen, Mohammad G.; Thadani, Udho; Probstfield, Jeffrey L.; Davis, Barry R.

    2011-01-01

    Background In the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), a randomized, double-blind, practice-based, active-control, comparative effectiveness trial in high-risk hypertensive participants, risk of new-onset heart failure (HF) was higher in the amlodipine (2.5-10 mg/day) and lisinopril (10-40 mg/day) arms compared with the chlorthalidone (12.5-25 mg/day) arm . Similar to other studies, mortality rates following new-onset HF were very high (≥50% at 5 years), and were similar across randomized treatment arms. After the randomized phase of the trial ended in 2002, outcomes were determined from administrative databases. Methods and Results Using national databases, post-trial follow-up mortality through 2006 was obtained on participants who developed new-onset HF during the randomized (in-trial) phase of ALLHAT. Mean follow-up for the entire period was 8.9 years. Of 1761 participants with incident HF in-trial, 1348 died. Post-HF all-cause mortality was similar across treatment groups with adjusted hazard ratios (95% confidence intervals) of 0.95 (0.81-1.12) and 1.05 (0.89-1.25), respectively, for amlodipine and lisinopril compared with chlorthalidone, and 10-year adjusted rates of 86%, 87%, and 83%, respectively. All-cause mortality rates were also similar among those with reduced ejection fractions (84%) and preserved ejection fractions (81%) with no significant differences by randomized treatment arm. Conclusions Once HF develops, risk of death is high and consistent across randomized treatment groups. Measures to prevent the development of HF, especially blood pressure control, must be a priority if mortality associated with development of HF is to be addressed. PMID:21969009

  4. The Unequal Structure of the German Education System: Structural Reasons for Educational Failures of Turkish Youth in Germany.

    Science.gov (United States)

    Fernandez-Kelly, Patricia

    The paper examines the educational experiences of Turkish youth in Germany with special references to the statistical data of Educational Report, PISA surveys. The results of the educational statistics of Germany show that more than group characteristics like social and cultural capital, structural and institutional factors (multi-track system with its selective mechanism, education policy, context of negative reception of Germany, institutional discrimination, and lack of intercultural curriculum) could have a decisive role in hampering the educational and labor market integration and social mobility of Turkish youth. This can be explained by a mix of factors: the education system which does not foster the educational progress of children from disadvantaged families; the high importance of school degrees for accessing to the vocational training system and the labor market; and direct and indirect institutional discrimination in educational area in Germany. Thus, this work suggests that the nature of the education system in Germany remains deeply "unequal," "hierarchical" and "exclusive." This study also demonstrates maintaining the marginalized position of Turkish children in Germany means that the country of origin or the immigrants' background is still a barrier to having access to education and the labor market of Germany.

  5. Effects of mechanical strain on the performance of germanene sheets: Strength, failure behavior, and electronic structure

    Science.gov (United States)

    Ding, Ning; Wang, Huan; Liu, Long; Guo, Weimin; Chen, Xiangfeng; Wu, Chi-Man Lawrence

    2018-02-01

    As a two-dimensional material with a low-buckling structure, germanene has attracted considerable interest because of its excellent physical properties, such as massless Dirac fermions and quantum spin Hall effect. The mechanical characteristics of germanene are of the utmost importance when one is assessing its viability for nanodevices, especially for ones with defects. In this work, the stabilities, mechanical properties, and changes in electronic properties under mechanical strain for both pristine and defective germanene sheets were studied and analyzed with use of density functional theory. The mechanical properties of defect-free germanene exhibited obvious anisotropy along different directions. The mechanical properties of germanene sheets exhibited high sensitivity to the defect parameters, such as the linear density of vacancies, the width of the cracks, and the inflection angles caused by the grain boundaries. In addition, the applied mechanical strain changed the electronic properties of germanene to a large extent. The information obtained will be useful for the understanding and potential application of germanene.

  6. The Causes of School Failure in Secondary School Students: Validation of a Psychosocial Model with Structural Equations.

    Science.gov (United States)

    Chacón Fuertes, Fernando; Huertas Hurtado, Carlos A

    2017-11-20

    The objective of the study was to determine the causal effects of school failure (SF) among secondary school students, belonging to five public schools within the region of Girardota, Colombia, through the validation of a psychosocial model with structural equations. A total of 319 students, 25% more males, enrolled in classes between 6th and 11th year, with an average age of 14 years. Furthermore, 265 parents and 200 teachers were also included in the sample. Participants answered the questions raised in 9 instruments. Of the total number of students, 63.8% were surveyed. The instruments were subjected to a pilot test and to the judgment of experts. In order to reduce the amount of data, exploratory and confirmatory factorial analyses were used. Other techniques of multivariate analysis such as decision trees and linear regressions were also used in order to previously evaluate the relationships between the independent variables (IV) and the dependent variable (DV). Afterwards, the Full SEM was calculated, yielding a model consisting of 34 variables (10 latent and 24 observable), with the following indexes of goodness of fit: CMIN/DF = 1.146, p = .058, IFI = 0.974, TLI = .970, CFI = .974, RMSEA = .027 and PCLOSE = 0.998. Theoretically, the model confirms the predictive value of the selected variables, with respect to school failure. The results are applicable to both the design of educational policies and the direct intervention in the classroom. In both contexts, strategies can be developed that reduce factors that negatively affect school performance, actively linking students, teachers and parents.

  7. The roles of tumor necrosis factor-alpha in colon tight junction protein expression and intestinal mucosa structure in a mouse model of acute liver failure

    Directory of Open Access Journals (Sweden)

    Lv Sa

    2009-09-01

    Full Text Available Abstract Background Spontaneous bacterial peritonitis (SBP is a common clinical disease and one of the most severe complications of acute liver failure (ALF. Although the mechanism responsible for SBP is unclear, cytokines play an important role. The aim of this study was to investigate the effects of tumor necrosis factor-alpha (TNF-α on the structure of the intestinal mucosa and the expression of tight junction (Zona Occludens 1; ZO-1 protein in a mouse model of ALF. Methods We induced ALF using D-galactosamine/lipopolysaccharide (GalN/LPS or GalN/TNF-α and assessed the results using transmission electron microscopy, immunohistochemistry, Western blotting, ELISA and real-time quantitative PCR. The effects of administration of anti-TNF-α IgG antibody or anti-TNF-α R1 antibody before administration of GalN/LPS or GalN/TNF-α, respectively, on TNF-α were also assessed. Results Morphological abnormalities in the intestinal mucosa of ALF mice were positively correlated with serum TNF-α level. Electron microscopic analysis revealed tight junction (TJ disruptions, epithelial cell swelling, and atrophy of intestinal villi. Gut bacteria invaded the body at sites where TJ disruptions occurred. Expression of ZO-1 mRNA was significantly decreased in both ALF models, as was the level of ZO-1 protein. Prophylactic treatment with either anti-TNF-α IgG antibody or anti-tumor necrosis factor-a receptor1 (anti-TNF-α R1 antibody prevented changes in intestinal tissue ultrastructure and ZO-1 expression. Conclusion TNF-α affects the structure of the intestinal mucosa, decreases expression of ZO-1, and affects the morphology of the colon in a mouse model of ALF. It also may participate in the pathophysiological mechanism of SBP complicated to ALF.

  8. Adoption of Smart Structures for Prevention of Health Hazards in Buildings

    Science.gov (United States)

    Oke, Ayodeji; Aigbavboa, Clinton; Ngema, Wiseman

    2017-11-01

    The importance of building quality to the health and well-being of occupants and surrounding neighbors cannot be overemphasized. Smart structures were construed to proffer solution to various issues of sustainable development including social factors that is concerned with health and safety of people. Based on existing literature materials on building quality, smart structures and general aspect of sustainable developments, this study examined the benefits of smart structures in the prevention of various health issues in infrastructural buildings, which has been a concern for stakeholders in the architecture, engineering and construction industry. The criterion for indoor environmental quality was adopted and various health and bodily issues related to building quality were explained. The adoption of smart structure concept will help to manage physical, chemical, biological and psychological factors of building with a view to enhancing better quality of life of occupants.

  9. A socio-structural approach to preventing injection drug use initiation: rationale for the PRIMER study.

    Science.gov (United States)

    Werb, Daniel; Garfein, Richard; Kerr, Thomas; Davidson, Peter; Roux, Perrine; Jauffret-Roustide, Marie; Auriacombe, Marc; Small, Will; Strathdee, Steffanie A

    2016-09-15

    Injection drug use remains a primary driver of HIV and HCV-related harms globally. However, there is a gap in efforts to prevent individuals from transitioning into injecting. People who inject drugs (PWID) play a key role in the transition of others into injecting, and while behavioral interventions have been developed to address this phenomenon, socio-structural approaches remain unexplored. To that end, we hypothesize that certain interventions designed to reduce injecting-related risk behaviors may also reduce the risk that PWID expose and introduce others into injecting. Identifying the preventive potential of existing interventions will inform broader efforts to prevent injecting and related harms. The Preventing Injecting by Modifying Existing Responses (PRIMER) study is a multi-country mixed methods study with an aim to investigate whether specific interventions (e.g., opioid substitution therapy, supervised injection facilities, stable housing, incarceration environments) and related factors (e.g., public injecting and gender) influence the likelihood that PWID initiate others into injecting. This study will (1) investigate the PWID participation in injection initiation; (2) identify factors influencing the risk that PWID expose others to or facilitate injection initiation; (3) describe drug scene roles that increase the risk of PWID facilitating injection initiation; and (4) evaluate the impact of structural, social, or biomedical interventions on the risk that PWID facilitate injection initiation. It does so by pooling observational data from cohort studies of PWID in six cities: Vancouver, Canada; San Diego, USA; Tijuana, Mexico; Paris, Marseille, and Bordeaux, France. Team members are conducting a prospective, multi-site study of PWID (n = 3050) in North America and France that includes quantitative and qualitative data collection through four separate cohort studies of PWID (San Diego, STAHR II; Tijuana, El Cuete IV; Vancouver, V-DUS; Bordeaux

  10. Structural drivers and social protection: mechanisms of HIV risk and HIV prevention for South African adolescents.

    Science.gov (United States)

    Cluver, Lucie Dale; Orkin, Frederick Mark; Meinck, Franziska; Boyes, Mark Edward; Sherr, Lorraine

    2016-01-01

    Social protection is high on the HIV-prevention agenda for youth in sub-Saharan Africa. However, questions remain: How do unconditional cash transfers work? What is the effect of augmenting cash provision with social care? And can "cash plus care" social protection reduce risks for adolescents most vulnerable to infection? This study tackles these questions by first identifying mediated pathways to adolescent HIV risks and then examining potential main and moderating effects of social protection in South Africa. This study was a prospective observational study of 3515 10-to-17-year-olds (56.7% female; 96.8% one-year retention). Within randomly selected census areas in four rural and urban districts in two South African provinces, all homes with a resident adolescent were sampled between 2009/2010 and 2011/2012. Measures included 1) potential structural drivers of HIV infection such as poverty and community violence; 2) HIV risk behaviours; 3) hypothesized psychosocial mediating factors; and 4) types of social protection involving cash and care. Using gender-disaggregated analyses, longitudinal mediation models were tested for potential main and moderating effects of social protection. Structural drivers were associated with increased onset of adolescent HIV risk behaviour (psocial protection were associated with reductions in HIV risk behaviour and psychosocial deprivations. In addition, cash social protection moderated risk pathways: for adolescent girls and boys experiencing more acute structural deprivation, social protection had the greatest associations with HIV risk prevention (e.g. moderation effects for girls: B=-0.08, psocial protection has the greatest prevention effects for the most vulnerable. Social protection comprising unconditional cash plus care was associated with reduced risk pathways through moderation and main effects, respectively. Our findings suggest the importance of social protection within a combination package of HIV-prevention

  11. An investment plan for preventing child injuries using risk priority number of failure mode and effects analysis methodology and a multi-objective, multi-dimensional mixed 0-1 knapsack model

    International Nuclear Information System (INIS)

    Bas, Esra

    2011-01-01

    In this paper, a general framework for child injury prevention and a multi-objective, multi-dimensional mixed 0-1 knapsack model were developed to determine the optimal time to introduce preventive measures against child injuries. Furthermore, the model maximises the prevention of injuries with the highest risks for each age period by combining preventive measures and supervision as well as satisfying budget limits and supervision time constraints. The risk factors for each injury, variable, and time period were based on risk priority numbers (RPNs) obtained from failure mode and effects analysis (FMEA) methodology, and these risk factors were incorporated into the model as objective function parameters. A numerical experiment based on several different situations was conducted, revealing that the model provided optimal timing of preventive measures for child injuries based on variables considered.

  12. Semiexperimental and mass-dependent structures by the mixed regression method: Accurate equilibrium structure and failure of the Kraitchman method for ethynylcyclohexane.

    Science.gov (United States)

    Vogt, Natalja; Demaison, Jean; Rudolph, Heinz Dieter; Juanes, Marcos; Fernández, Jairo; Lesarri, Alberto

    2018-02-14

    The mixed regression method for determination of molecular structures is reviewed and applied to the investigation of ethynylcyclohexane, using both semiexperimental and mass-dependent methods. This methodology provides an efficient and computationally affordable route to obtain accurate molecular reference data, preventing ill-conditioning in the structural least-squares determinations from experimental rotational constants. New supersonic-jet microwave measurements are reported to obtain inertial data for the axial and equatorial species of ethynylcyclohexane, together with all 13 C isotopologues of the equatorial form. The semiexperimental equilibrium (r e SE ) and mass-dependent (r m (2) ) structures of the molecule are compared with high-level ab initio optimizations, showing that both methods deliver compatible structures with accuracies of about 0.002 Å for bond lengths and 0.2° for bond angles. We confirm that dependable predicates can be obtained for a large variety of bonds. Finally, we verify that the substitution method completely fails to determine a reliable structure for the title compound.

  13. The Structure and Nephroprotective Activity of Oligo-Porphyran on Glycerol-Induced Acute Renal Failure in Rats

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2017-05-01

    Full Text Available Porphyran is a sulfate galactan in the cell wall of Porphyra. Its acid hydrolysis product, oligo-porphyran (OP, was prepared and the structure studied by electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS. This oligosaccharide was mainly composed of monosulfate-oligo-galactan, disufate-oligo-galactan, trisulfate-oligo-galactan, trisulfate oligo-methyl-galactan, and 3,6-anhydrogalactose with the degree of polymerization ranging from 1 to 8. The effects of OP were investigated in the glycerol-induced acute renal failure (ARF model. Compared with the normal group, rats from the glycerol-induced group exhibited collecting duct and medullary ascending limb dilation and casts. The OP-treated group exerted a protective effect against glycerol-induced changes. The results showed that the administration of OP markedly decreased mortality in female ARF rats. For male ARF rats, all of which survived, OP significantly decreased the blood urea nitrogen and serum creatinine levels. Ion levels in plasma and urine were significantly changed in ARF rats, whereas OP treatment almost recovered ion levels back to normal. This study showed a noticeable renal morphologic and functional protection by OP in glycerol-induced ARF rats.

  14. When things go wrong: how health care organizations deal with major failures.

    Science.gov (United States)

    Walshe, Kieran; Shortell, Stephen M

    2004-01-01

    Concern about patient safety, caused in part by high-profile major failures in which many patients have been harmed, is rising worldwide. This paper draws on examples of such failures from several countries to analyze how these events are dealt with and to identify lessons and recommendations for policy. Better systems are needed for reporting and investigating failures and for implementing the lessons learned. The culture of secrecy, professional protectionism, defensiveness, and deference to authority is central to such major failures, and preventing future failures depends on cultural as much as structural change in health care systems and organizations.

  15. 3D printed, bio-inspired prototypes and analytical models for structured suture interfaces with geometrically-tuned deformation and failure behavior

    Science.gov (United States)

    Lin, Erica; Li, Yaning; Ortiz, Christine; Boyce, Mary C.

    2014-12-01

    Geometrically structured interfaces in nature possess enhanced, and often surprising, mechanical properties, and provide inspiration for materials design. This paper investigates the mechanics of deformation and failure mechanisms of suture interface designs through analytical models and experiments on 3D printed polymer physical prototypes. Suture waveforms with generalized trapezoidal geometries (trapezoidal, rectangular, anti-trapezoidal, and triangular) are studied and characterized by several important geometric parameters: the presence or absence of a bonded tip region, the tip angle, and the geometry. It is shown that a wide range (in some cases as great as an order of magnitude) in stiffness, strength, and toughness is achievable dependent on tip bonding, tip angle, and geometry. Suture interfaces with a bonded tip region exhibit a higher initial stiffness due to the greater load bearing by the skeletal teeth, a double peak in the stress-strain curve corresponding to the failure of the bonded tip and the failure of the slanted interface region or tooth, respectively, and an additional failure and toughening mechanism due to the failure of the bonded tip. Anti-trapezoidal geometries promote the greatest amplification of properties for suture interfaces with a bonded tip due the large tip interface area. The tip angle and geometry govern the stress distributions in the teeth and the ratio of normal to shear stresses in the interfacial layers, which together determine the failure mechanism of the interface and/or the teeth. Rectangular suture interfaces fail by simple shearing of the interfaces. Trapezoidal and triangular suture interfaces fail by a combination of shear and tensile normal stresses in the interface, leading to plastic deformation, cavitation events, and subsequent stretching of interface ligaments with mostly elastic deformation in the teeth. Anti-trapezoidal suture interfaces with small tip angles have high stress concentrations in the teeth

  16. Agreement between structured checklists and Medicaid claims for preventive dental visits in primary care medical offices.

    Science.gov (United States)

    Pahel, Bhavna T; Rozier, R Gary; Stearns, Sally C

    2010-06-01

    For program evaluation purposes, the feasibility of matching Medicaid claims with physician-completed structured checklists (encounter forms, EFs) was assessed in a pediatric office-based preventive dental program. We examined agreement on visits (weighted kappa) and predictors of a match between EFs and claims (multinomial logit model with practice-level clustering). In total, 34,171 matches occurred between 41,252 EFs and 40,909 claims, representing 82.8 per cent of EFs and 83.5 per cent of claims. Agreement on visits was 56 per cent (weighted kappa = 0.66). Pediatric practices provided the majority of visits (82.4%) and matches. Increasing age of child and residence in same county as the medical practice increased the likelihood of a match. Structured checklists can be combined with claims to better assess provision of preventive dental services in pediatric primary care. However, future research should examine strategies to improve the completion of structured checklists by primary care providers if data beyond claims are to be used for program evaluation.

  17. Budding Uninhibited by Benzimidazole-1 Insufficiency Prevents Acute Renal Failure in Severe Sepsis by Maintaining Anti-Coagulant Functions of Vascular Endothelial Cells.

    Science.gov (United States)

    Matsubara, Yutaka; Matsumoto, Takuya; Yoshiya, Keiji; Yoshida, Ayae; Ikeda, Seiichi; Furuyama, Tadashi; Nakatsu, Yoshimichi; Tsuzuki, Teruhisa; Nomura, Masatoshi; Maehara, Yoshihiko

    2018-03-30

    Severe sepsis is critical to health and can result in acute renal failure (ARF). Tissue factor (TF) and thrombomodulin (TM) play key roles in vascular endothelial functions by helping maintain microcirculation in the kidney. Budding uninhibited by benzimidazole-1 (Bub1) plays a role in Akt and JNK signaling, which control TF and TM, respectively. We hypothesized that Bub1 could control vascular endothelial function in sepsis. The aim of this study was to determine the role of Bub1 in septic ARF. We used Mouse cecum ligation and puncture (CLP) using low Bub1 expressing (Bub1) and wild-type (Bub1) mice in vivo and lipopolysaccharide (LPS) stimulation of human aortic endothelial cell (HAEC) in vitro. Bub1 mice had a higher survival rate after CLP than Bub1. Bub1 mice had more severe ARF after CLP than Bub1 with blood biochemical and pathological analyses. TF expression in Bub1 mice and control HAEC (control) significantly increased in the septic model compared with Bub1 and Bub1 silenced HAEC (siBub1). TM expression in the control significantly decreased after LPS stimulation compared with siBub1. Akt and JNK phosphorylation of siBub1 were attenuated after LPS stimulation. Associations of Bub1 with Akt or JNK after LPS stimulation of HAEC were detected using immunoprecipitation, suggesting that Bub1 is involved in the phosphorylation of Akt and JNK after LPS stimulation. Bub1 insufficiency attenuates TF expression and reduces TM suppression by blocking Akt and JNK phosphorylation, respectively, thus leading to the prevention of ARF and death caused by sepsis.

  18. Management of Arrhythmias in Heart Failure

    Science.gov (United States)

    Masarone, Daniele; Limongelli, Giuseppe; Rubino, Marta; Valente, Fabio; Vastarella, Rossella; Ammendola, Ernesto; Gravino, Rita; Verrengia, Marina; Salerno, Gemma; Pacileo, Giuseppe

    2017-01-01

    Heart failure patients are predisposed to develop arrhythmias. Supraventricular arrhythmias can exacerbate the heart failure symptoms by decreasing the effective cardiac output and their control require pharmacological, electrical, or catheter-based intervention. In the setting of atrial flutter or atrial fibrillation, anticoagulation becomes paramount to prevent systemic or cerebral embolism. Patients with heart failure are also prone to develop ventricular arrhythmias that can present a challenge to the managing clinician. The management strategy depends on the type of arrhythmia, the underlying structural heart disease, the severity of heart failure, and the range from optimization of heart failure therapy to catheter ablation. Patients with heart failure, irrespective of ejection fraction are at high risk for developing sudden cardiac death, however risk stratification is a clinical challenge and requires a multiparametric evaluation for identification of patients who should undergo implantation of a cardioverter defibrillator. Finally, patients with heart failure can also develop symptomatic bradycardia, caused by sinus node dysfunction or atrio-ventricular block. The treatment of bradycardia in these patients with pacing is usually straightforward but needs some specific issue. PMID:29367535

  19. Tumour lysis syndrome and acute renal failure in Burkitt's lymphoma. Description of 2 cases and a review of the literature on prevention and management

    NARCIS (Netherlands)

    Veenstra, J.; Krediet, R. T.; Somers, R.; Arisz, L.

    1994-01-01

    Two patients with Burkitt's lymphoma and acute renal failure are described, one with acute uric acid nephropathy and the other with acute renal failure due to hyperphosphataemia. Renal insufficiency caused by the precipitation of calcium phosphate salts only occurs after starting treatment of the

  20. Structural and functional changes in the heart and clinical features of heart failure with preserved left ventricular ejection fraction in patients after myocardial infarction, comorbided with arterial hypertension

    Directory of Open Access Journals (Sweden)

    V. D. Syvolap

    2013-12-01

    Full Text Available Recently, much attention was paid to left ventricular diastolic dysfunction and its role in the occurrence of chronic heart failure. In patients after myocardial infarction, diastolic dysfunction often precedes systolic dysfunction and predicts prognosis. In patients after myocardial infarction, diastolic dysfunction is caused by a violation of early diastolic relaxation in the area of increasing stiffness. Diastolic dysfunction is formed by hypertrophy, fibrosis, myocardial ischemia and arterial hypertension. Given the important role of diastolic dysfunction in the formation of heart failure in postinfarction patients with concomitant arterial hypertension, the mechanisms of its impact on clinical features and structural-functional changes of the heart is an actual problem. Objective: To determine the structural and functional changes in the heart and clinical features of heart failure with preserved left ventricular ejection fraction in patients after myocardial infarction with concomitant arterial hypertension. Materials and methods: In 91 patients with post-infarction cardiosclerosis and preserved left ventricular ejection fraction (EF > 45 % with arterial hypertension were investigated structural and functional changes in the heart and clinical features of heart failure by assessing clinical status and ultrasound of the heart. Prescription myocardial infarction ranged from 2 months to 3 years. Patients were divided into 3 groups. The first group included 50 patients with diastolic dysfunction and symptoms of heart failure (mean age 64,1 ± 1,2 years. In the second group were 31 patients with diastolic dysfunction without heart failure symptoms (mean age 59,5 ± 1,6 years. The third group consisted of 10 patients without diastolic dysfunction and manifestations of heart failure (mean age 57 ± 2,8 years. Results and discussion: 10% patients with postinfarction cardiosclerosis and concomitant hypertension with diastolic heart failure had NYHA

  1. Insulin Signaling and Heart Failure

    Science.gov (United States)

    Riehle, Christian; Abel, E. Dale

    2016-01-01

    Heart failure is associated with generalized insulin resistance. Moreover, insulin resistant states such as type 2 diabetes and obesity increases the risk of heart failure even after adjusting for traditional risk factors. Insulin resistance or type 2 diabetes alters the systemic and neurohumoral milieu leading to changes in metabolism and signaling pathways in the heart that may contribute to myocardial dysfunction. In addition, changes in insulin signaling within cardiomyocytes develop in the failing heart. The changes range from activation of proximal insulin signaling pathways that may contribute to adverse left ventricular remodeling and mitochondrial dysfunction to repression of distal elements of insulin signaling pathways such as forkhead (FOXO) transcriptional signaling or glucose transport which may also impair cardiac metabolism, structure and function. This article will review the complexities of insulin signaling within the myocardium and ways in which these pathways are altered in heart failure or in conditions associated with generalized insulin resistance. The implications of these changes for therapeutic approaches to treating or preventing heart failure will be discussed. PMID:27034277

  2. Exploring the role of genome and structural ions in preventing viral capsid collapse during dehydration

    Science.gov (United States)

    Martín-González, Natalia; Guérin Darvas, Sofía M.; Durana, Aritz; Marti, Gerardo A.; Guérin, Diego M. A.; de Pablo, Pedro J.

    2018-03-01

    Even though viruses evolve mainly in liquid milieu, their horizontal transmission routes often include episodes of dry environment. Along their life cycle, some insect viruses, such as viruses from the Dicistroviridae family, withstand dehydrated conditions with presently unknown consequences to their structural stability. Here, we use atomic force microscopy to monitor the structural changes of viral particles of Triatoma virus (TrV) after desiccation. Our results demonstrate that TrV capsids preserve their genome inside, conserving their height after exposure to dehydrating conditions, which is in stark contrast with other viruses that expel their genome when desiccated. Moreover, empty capsids (without genome) resulted in collapsed particles after desiccation. We also explored the role of structural ions in the dehydration process of the virions (capsid containing genome) by chelating the accessible cations from the external solvent milieu. We observed that ion suppression helps to keep the virus height upon desiccation. Our results show that under drying conditions, the genome of TrV prevents the capsid from collapsing during dehydration, while the structural ions are responsible for promoting solvent exchange through the virion wall.

  3. Acute heart failure syndrome

    African Journals Online (AJOL)

    Heart failure can be defined as a clinical syndrome in which a structural or functional cardiac abnormality impairs the capacity of the ventricle to fill or eject enough blood for the requirements of the body. Acute heart failure syndrome represents a complex, heterogeneous set of clinical conditions, all with the common.

  4. Vascular wall proteoglycan synthesis and structure as a target for the prevention of atherosclerosis

    Directory of Open Access Journals (Sweden)

    Peter J Little

    2007-03-01

    Full Text Available Peter J Little1, 2, 3, Mandy L. Ballinger1, Narin Osman1,31Cell Biology of Diabetes Laboratory, Baker Heart Research Institute, Melbourne, Australia; Monash University, Departments of 2Medicine and 3Immunology, Central and Eastern Clinical School, Alfred Hospital, Melbourne, AustraliaAbstract: Atherosclerosis is the underlying pathology of most cardiovascular disease and it represents the major cause of premature death in modern societies. Current therapies target risk factors being hypertension, hypercholesterolemia, hypertriglyceridemia and hyperglycemia when diabetes is present however the maximum efficacy of these strategies is often 30% or less. Areas of vascular biology that may lead to the development of a complementary vascular wall directed therapy are: inflammation, oxidation, endothelial dysfunction, diabetes-specific factors —hyperglycemia and advanced glycation endproducts and lipid retention by vascular matrix specifically proteoglycans. The major structural features of proteoglycans that determine low-density lipoprotein (LDL binding are the length and sulfation pattern on the glycosaminoglycan (GAG chains. Emerging data discussed in this review indicates that these structural properties are subject to considerable regulation by vasoactive substances possibly using novel signaling pathways. For example, GAG elongation stimulated by platelet-derived growth factor is not blocked by the receptor tyrosine kinase antagonist, genistein suggesting that there may be a previously unknown signaling pathway involved in this response. Thus, modifying proteoglycan synthesis and structure may represent a prime target to prevent LDL binding and entrapment in the vessel wall and thus prevent the development and progression of atherosclerosis.Keywords: proteoglycans, signaling, lipoproteins, atherosclerosis

  5. Kidney Failure

    Science.gov (United States)

    ... enough red blood cells. This is called kidney failure. If your kidneys fail, you need treatment to ... providers, family, and friends, most people with kidney failure can lead full and active lives. NIH: National ...

  6. Respiratory Failure

    Science.gov (United States)

    Respiratory failure happens when not enough oxygen passes from your lungs into your blood. Your body's organs, such as ... need oxygen-rich blood to work well. Respiratory failure also can happen if your lungs can't ...

  7. Definition of containment failure

    International Nuclear Information System (INIS)

    Cybulskis, P.

    1982-01-01

    Core meltdown accidents of the types considered in probabilistic risk assessments (PRA's) have been predicted to lead to pressures that will challenge the integrity of containment structures. Review of a number of PRA's indicates considerable variation in the predicted probability of containment failure as a function of pressure. Since the results of PRA's are sensitive to the prediction of the occurrence and the timing of containment failure, better understanding of realistic containment capabilities and a more consistent approach to the definition of containment failure pressures are required. Additionally, since the size and location of the failure can also significantly influence the prediction of reactor accident risk, further understanding of likely failure modes is required. The thresholds and modes of containment failure may not be independent

  8. Heart Failure

    DEFF Research Database (Denmark)

    Jorsal, Anders; Wiggers, Henrik; McMurray, John J V

    2018-01-01

    This article briefly discusses the epidemiology of heart failure and diabetes and summarizes the key findings from the recent cardiovascular outcome trials in patients with type 2 diabetes, with a focus on heart failure as an endpoint.......This article briefly discusses the epidemiology of heart failure and diabetes and summarizes the key findings from the recent cardiovascular outcome trials in patients with type 2 diabetes, with a focus on heart failure as an endpoint....

  9. Heart Failure

    Science.gov (United States)

    Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Heart failure does not mean that your heart has stopped ... and shortness of breath Common causes of heart failure are coronary artery disease, high blood pressure and ...

  10. High Structural Stability of Textile Implants Prevents Pore Collapse and Preserves Effective Porosity at Strain

    Directory of Open Access Journals (Sweden)

    Uwe Klinge

    2015-01-01

    Full Text Available Reinforcement of tissues by use of textiles is encouraged by the reduced rate of recurrent tissue dehiscence but for the price of an inflammatory and fibrotic tissue reaction to the implant. The latter mainly is affected by the size of the pores, whereas only sufficiently large pores are effective in preventing a complete scar entrapment. Comparing two different sling implants (TVT and SIS, which are used for the treatment of urinary incontinence, we can demonstrate that the measurement of the effective porosity reveals considerable differences in the textile construction. Furthermore the changes of porosity after application of a tensile load can indicate a structural instability, favouring pore collapse at stress and questioning the use for purposes that are not “tension-free.”

  11. Long-term efficacy of implantable cardiac resynchronization therapy plus defibrillator for primary prevention of sudden cardiac death in patients with mild heart failure: an updated meta-analysis.

    Science.gov (United States)

    Sun, Wei-Ping; Li, Chun-Lei; Guo, Jin-Cheng; Zhang, Li-Xin; Liu, Ran; Zhang, Hai-Bin; Zhang, Ling

    2016-07-01

    Previous studies of implantable cardiac resynchronization therapy plus defibrillator (CRT-D) therapy used for primary prevention of sudden cardiac death have suggested that CRT-D therapy is less effective in patients with mild heart failure and a wide QRS complex. However, the long-term benefits are variable. We performed a meta-analysis of randomized trials identified in systematic searches of MEDLINE, EMBASE, and the Cochrane Database. Three studies (3858 patients) with a mean follow-up of 66 months were included. Overall, CRT-D therapy was associated with significantly lower all-cause mortality than was implantable cardioverter defibrillator (ICD) therapy (OR, 0.78; 95 % CI, 0.63-0.96; P = 0.02; I (2) = 19 %). However, the risk of cardiac mortality was comparable between two groups (OR, 0.74; 95 % CI, 0.53-1.01; P = 0.06). CRT-D treatment was associated with a significantly lower risk of hospitalization for heart failure (OR, 0.67; 95 % CI, 0.50-0.89; P = 0.005; I (2) = 55 %). The composite outcome of all-cause mortality and hospitalization for heart failure was also markedly lower with CRT-D therapy than with ICD treatment alone (OR, 0.67; 95 % CI, 0.57-0.77; P failure events in patients with mild heart failure with a wide QRS complex. However, long-term risk of cardiac mortality was similar between two groups. More randomized studies are needed to confirm these findings, especially in patients with NYHA class I heart failure or patients without LBBB.

  12. Feasibility of including patients with migration background in a structured heart failure management programme: A prospective case-control study exemplarily on Turkish migrants.

    Directory of Open Access Journals (Sweden)

    Roman Pfister

    Full Text Available Structured management programmes deliver optimized care in heart failure patients and improve outcome. We examined the feasibility of including patients with migration background speaking little or no German in a heart failure management programme.After adaption of script material and staff to Turkish language we aimed to recruit 300 Turkish and 300 German (control group patients within 18 months using the operational basis of a local heart failure management programme for screening, contact and inclusion. Of 488 and 1,055 eligible Turkish and German patients identified through screening, 165 Turkish (34% and 335 German (32% patients consented on participation (p = 0.46. General practitioners contributed significantly more of the Turkish (84% than of the German patients (16%, p<0.001. Contact attempts by programme staff were significantly less successful in Turkish (52% than in German patients (60%, p = 0.005 due to significantly higher rate of missing phone numbers (36% vs 25%, invalid address data (28% vs 7% and being unreachable by phone more frequently (39% vs 26%, all p<0.001. Consent rate was significantly higher in successfully contacted Turkish (63% compared to German patients (50%, p<0.001.The inclusion of Turkish minority patients into a heart failure management programme is feasible with higher consent rate than in Germans. However, effort is high due to inherent logistic adaptions and barriers in identification and contacting of patients.DRKS00007780.

  13. Structural actions toward HIV/AIDS prevention in Cartagena, Colombia: a qualitative study.

    Science.gov (United States)

    Quevedo-Gómez, María Cristina; Krumeich, Anja; Abadía-Barrero, César Ernesto; Pastrana-Salcedo, Eduardo Manuel; van den Borne, Hubertus

    2011-07-01

    To obtain a thorough understanding of the complexity and dynamics of the social determination of HIV infection among inhabitants of Cartagena, Colombia, as well as their views on necessary actions and priorities. In a five-year ethnography of HIV/AIDS in collaboration with 96 citizens of Cartagena, different methods and data collection techniques were used. Through 40 in-depth interviews and 30 life histories of inhabitants, the scenario of HIV vulnerability was summarized in a diagram. This diagram was evaluated and complemented through group discussions with key representatives of local governmental and nongovernmental organizations and with people who were interested in the epidemic or affected by it. The diagram illustrates the dynamic and complex interrelationships among structural factors (i.e., social determinants) of HIV infection, such as machismo; lack of work, money, and social services; local dynamics of the performance of the state; and international dynamics of the sexual tourism industry. On the basis of the diagram, groups of key representatives proposed prioritizing structural actions such as reducing socioeconomic inequalities and providing access to health care and education. The social determinants displayed in the diagram relate to historic power forces that have shaped vulnerable scenarios in Cartagena. Collaboration between participants and researchers generates conceptual frameworks that make it possible to understand and manage the complexity of HIV's social determination. This way of understanding effectively connects local inequalities with international flows of power such as sexual tourism and makes evident the strengths and limitations of current approaches to HIV prevention.

  14. Risky Business: condom failures as experienced by female sex workers in Mombasa, Kenya.

    Science.gov (United States)

    Bradburn, Caitlyn K; Wanje, George; Pfeiffer, James; Jaoko, Walter; Kurth, Ann E; McClelland, R Scott

    2017-03-01

    Limited research exists about condom failure as experienced by female sex workers. We conducted a qualitative study to examine how female sex workers in Mombasa, Kenya contextualise and explain the occurrence of condom failure. In-depth, semi-structured interviews were conducted with thirty female sex workers to ascertain their condom failure experiences. We qualitatively analysed interview transcripts to determine how the women mitigate risk and cope with condom failure. Condom failure was not uncommon, but women mitigated the risk by learning about correct use, and by supplying and applying condoms themselves. Many female sex workers felt that men intentionally rupture condoms. Few women were aware of or felt empowered to prevent HIV, STIs, and pregnancy after condom failure. Interventions to equip female sex workers with strategies for minimising the risk of HIV, STIs, and pregnancy in the aftermath of a condom failure should be investigated.

  15. Study of human factors, and its basic aspects focusing the IEA-R1 research reactor operators, aiming at the prevention of accidents caused by human failures

    International Nuclear Information System (INIS)

    Martins, Maria da Penha Sanches

    2008-01-01

    This work presents a study of human factors and possible human failure reasons that can cause incidents, accidents and workers exposition, associated to risks intrinsic to the profession. The objective is to contribute with the operators of IEA-R1 reactor located at IPEN CNEN/S P. Accidents in the technological field, including the nuclear, have shown that the causes are much more connected to human failure than to system and equipment failures, what has led the regulatory bodies to consider studies on human failure. The research proposed in this work is quantitative/qualitative and also descriptive. Two questionnaires were used to collect data. The first of them was elaborated from the safety culture attributes which are described by the International Atomic Energy Agency - IAEA. The second considered individual and situational factors composing categories that could affect people in the work area. A carefully selected transcription of the theoretical basis according to the study of human factors was used. The methodology demonstrated a good reliability degree. Results lead to mediate factors which need direct actions concerning the needs of the group and of the individual. This research shows that it is necessary to have a really effective unit of planning and organization, not only to the physical and psychological health issues but also to the safety in the work. (author)

  16. Vitamin D and Heart Failure.

    Science.gov (United States)

    Marshall Brinkley, D; Ali, Omair M; Zalawadiya, Sandip K; Wang, Thomas J

    2017-10-01

    Vitamin D is principally known for its role in calcium homeostasis, but preclinical studies implicate multiple pathways through which vitamin D may affect cardiovascular function and influence risk for heart failure. Many adults with cardiovascular disease have low vitamin D status, making it a potential therapeutic target. We review the rationale and potential role of vitamin D supplementation in the prevention and treatment of chronic heart failure. Substantial observational evidence has associated low vitamin D status with the risk of heart failure, ventricular remodeling, and clinical outcomes in heart failure, including mortality. However, trials assessing the influence of vitamin D supplementation on surrogate markers and clinical outcomes in heart failure have generally been small and inconclusive. There are insufficient data to recommend routine assessment or supplementation of vitamin D for the prevention or treatment of chronic heart failure. Prospective trials powered for clinical outcomes are warranted.

  17. High-Fiber Diet and Acetate Supplementation Change the Gut Microbiota and Prevent the Development of Hypertension and Heart Failure in Hypertensive Mice.

    Science.gov (United States)

    Marques, Francine Z; Nelson, Erin; Chu, Po-Yin; Horlock, Duncan; Fiedler, April; Ziemann, Mark; Tan, Jian K; Kuruppu, Sanjaya; Rajapakse, Niwanthi W; El-Osta, Assam; Mackay, Charles R; Kaye, David M

    2017-03-07

    Dietary intake of fruit and vegetables is associated with lower incidence of hypertension, but the mechanisms involved have not been elucidated. Here, we evaluated the effect of a high-fiber diet and supplementation with the short-chain fatty acid acetate on the gut microbiota and the prevention of cardiovascular disease. Gut microbiome, cardiorenal structure/function, and blood pressure were examined in sham and mineralocorticoid excess-treated mice with a control diet, high-fiber diet, or acetate supplementation. We also determined the renal and cardiac transcriptome of mice treated with the different diets. We found that high consumption of fiber modified the gut microbiota populations and increased the abundance of acetate-producing bacteria independently of mineralocorticoid excess. Both fiber and acetate decreased gut dysbiosis, measured by the ratio of Firmicutes to Bacteroidetes, and increased the prevalence of Bacteroides acidifaciens . Compared with mineralocorticoid-excess mice fed a control diet, both high-fiber diet and acetate supplementation significantly reduced systolic and diastolic blood pressures, cardiac fibrosis, and left ventricular hypertrophy. Acetate had similar effects and markedly reduced renal fibrosis. Transcriptome analyses showed that the protective effects of high fiber and acetate were accompanied by the downregulation of cardiac and renal Egr1 , a master cardiovascular regulator involved in cardiac hypertrophy, cardiorenal fibrosis, and inflammation. We also observed the upregulation of a network of genes involved in circadian rhythm in both tissues and downregulation of the renin-angiotensin system in the kidney and mitogen-activated protein kinase signaling in the heart. A diet high in fiber led to changes in the gut microbiota that played a protective role in the development of cardiovascular disease. The favorable effects of fiber may be explained by the generation and distribution of one of the main metabolites of the gut

  18. Finite element analysis and CT-based structural rigidity analysis to assess failure load in bones with simulated lytic defects.

    Science.gov (United States)

    Anez-Bustillos, Lorenzo; Derikx, Loes C; Verdonschot, Nico; Calderon, Nathan; Zurakowski, David; Snyder, Brian D; Nazarian, Ara; Tanck, Esther

    2014-01-01

    There is an urgent need to improve the prediction of fracture risk for cancer patients with bone metastases. Pathological fractures that result from these tumors frequently occur in the femur. It is extremely difficult to determine the fracture risk even for experienced physicians. Although evolving, fracture risk assessment is still based on inaccurate predictors estimated from previous retrospective studies. As a result, many patients are surgically over-treated, whereas other patients may fracture their bones against expectations. We mechanically tested ten pairs of human cadaveric femurs to failure, where one of each pair had an artificial defect simulating typical metastatic lesions. Prior to testing, finite element (FE) models were generated and computed tomography rigidity analysis (CTRA) was performed to obtain axial and bending rigidity measurements. We compared the two techniques on their capacity to assess femoral failure load by using linear regression techniques, Student's t-tests, the Bland-Altman methodology and Kendall rank correlation coefficients. The simulated FE failure loads and CTRA predictions showed good correlation with values obtained from the experimental mechanical testing. Kendall rank correlation coefficients between the FE rankings and the CTRA rankings showed moderate to good correlations. No significant differences in prediction accuracy were found between the two methods. Non-invasive fracture risk assessment techniques currently developed both correlated well with actual failure loads in mechanical testing suggesting that both methods could be further developed into a tool that can be used in clinical practice. The results in this study showed slight differences between the methods, yet validation in prospective patient studies should confirm these preliminary findings. © 2013.

  19. Robust Structural Analysis and Design of Distributed Control Systems to Prevent Zero Dynamics Attacks

    Energy Technology Data Exchange (ETDEWEB)

    Weerakkody, Sean [Carnegie Mellon Univ., Pittsburgh, PA (United States); Liu, Xiaofei [Carnegie Mellon Univ., Pittsburgh, PA (United States); Sinopoli, Bruno [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2017-12-12

    We consider the design and analysis of robust distributed control systems (DCSs) to ensure the detection of integrity attacks. DCSs are often managed by independent agents and are implemented using a diverse set of sensors and controllers. However, the heterogeneous nature of DCSs along with their scale leave such systems vulnerable to adversarial behavior. To mitigate this reality, we provide tools that allow operators to prevent zero dynamics attacks when as many as p agents and sensors are corrupted. Such a design ensures attack detectability in deterministic systems while removing the threat of a class of stealthy attacks in stochastic systems. To achieve this goal, we use graph theory to obtain necessary and sufficient conditions for the presence of zero dynamics attacks in terms of the structural interactions between agents and sensors. We then formulate and solve optimization problems which minimize communication networks while also ensuring a resource limited adversary cannot perform a zero dynamics attacks. Polynomial time algorithms for design and analysis are provided.

  20. Structure-Based Design of a Periplasmic Binding Protein Antagonist that Prevents Domain Closure

    Energy Technology Data Exchange (ETDEWEB)

    Borrok, M. Jack; Zhu, Yimin; Forest, Katrina T.; Kiessling, Laura L.; (UW)

    2009-07-31

    Many receptors undergo ligand-induced conformational changes to initiate signal transduction. Periplasmic binding proteins (PBPs) are bacterial receptors that exhibit dramatic conformational changes upon ligand binding. These proteins mediate a wide variety of fundamental processes including transport, chemotaxis, and quorum sensing. Despite the importance of these receptors, no PBP antagonists have been identified and characterized. In this study, we identify 3-O-methyl-D-glucose as an antagonist of glucose/galactose-binding protein and demonstrate that it inhibits glucose chemotaxis in E. coli. Using small-angle X-ray scattering and X-ray crystallography, we show that this antagonist acts as a wedge. It prevents the large-scale domain closure that gives rise to the active signaling state. Guided by these results and the structures of open and closed glucose/galactose-binding protein, we designed and synthesized an antagonist composed of two linked glucose residues. These findings provide a blueprint for the design of new bacterial PBP inhibitors. Given the key role of PBPs in microbial physiology, we anticipate that PBP antagonists will have widespread uses as probes and antimicrobial agents.

  1. Method for estimating failure probabilities of structural components and its application to fatigue problem of internally cooled superconductors

    International Nuclear Information System (INIS)

    Shibui, M.

    1989-01-01

    A new method for fatigue-life assessment of a component containing defects is presented such that a probabilistic approach is incorporated into the CEGB two-criteria method. The present method assumes that aspect ratio of initial defect, proportional coefficient of fatigue crack growth law and threshold stress intensity range are treated as random variables. Examples are given to illustrate application of the method to the reliability analysis of conduit for an internally cooled cabled superconductor (ICCS) subjected to cyclic quench pressure. The possible failure mode and mechanical properties contributing to the fatigue life of the thin conduit are discussed using analytical and experimental results. 9 refs., 9 figs

  2. Myocardial structural, contractile and electrophysiological changes in the guinea-pig heart failure model induced by chronic sympathetic activation

    DEFF Research Database (Denmark)

    Soltysinska, Ewa; Osadchiy, Oleg; Olesen, Søren-Peter

    2011-01-01

    at variable dosage and duration using either subcutaneously implanted osmotic minipumps or daily injections, in an attempt to establish the relevant treatment protocol. We found that 3 months of daily ISO injections (final dose of 1 mg kg(-1), i.p.) promote heart failure evidenced by cardiac hypertrophy...... pressure-volume and stress-strain relationships assessed in isolated, perfused heart preparations), reduced contractile reserve in the presence of acute ß-adrenoceptor stimulation, and pulmonary oedema (increased lung weights). These changes were associated with prolongation of LV epicardial action...

  3. Multi-axial model of anisotropic damage: numerical management of failure and application to the ruin of reinforced concrete structures under impact

    International Nuclear Information System (INIS)

    Leroux, A.

    2012-01-01

    The objective of this research thesis is to develop the most precise possible numeric modelling of reinforced concrete behaviour with application to the design of structures of protection of nuclear plants against violent dynamic loadings (explosions, impacts). After a discussion of existing models, of their benefits and weaknesses, a multi-axial model of anisotropic damage is proposed and implemented with the finite element method. A new procedure of failure management is also proposed which allows the induced anisotropic damage to be taken into account. Impact tests on concrete beams and concrete cubes with longitudinal steel have been performed in order to validate the model [fr

  4. The Innovative Structure Solution for Preventing Salt Intrusion and Retaining Freshwater In Mekong Delta VietNam

    NARCIS (Netherlands)

    Hong, S.T.; Vrijling, J.K.; Stive, M.J.F.

    2013-01-01

    In the Mekong Delta Vietnam, the construction of sluices with the purpose of retaining fresh water and preventing salt water intrusion potentially plays a very important role. However, the structures constructed in small rivers according to local or traditional technology revealed many disadvantages

  5. Mobilizing Communities around HIV Prevention for Youth: How Three Coalitions Applied Key Strategies to Bring about Structural Changes

    Science.gov (United States)

    Chutuape, Kate S.; Willard, Nancy; Sanchez, Kenia; Straub, Diane M.; Ochoa, Tara N.; Howell, Kourtney; Rivera, Carmen; Ramos, Ibrahim; Ellen, Jonathan M.

    2010-01-01

    Increasingly, HIV prevention efforts must focus on altering features of the social and physical environment to reduce risks associated with HIV acquisition and transmission. Community coalitions provide a vehicle for bringing about sustainable structural changes. This article shares lessons and key strategies regarding how three community…

  6. Discontinuous modelling of masonry failure

    OpenAIRE

    VANDOREN, Bram

    2013-01-01

    A robust and efficient numerical model is a valuable engineering tool for predicting the load-bearing capacity and failure mode of masonry structures. Such a computational model consists of three key ingredients: a constitutive law which incorporates the non-linear material responses, a kinematic framework for describing failure mechanisms, and a solution algorithm which is capable of modelling the complete loading behaviour of a structure up to total failure. This work focuses on the latter ...

  7. Mechanism and Prevention of a Chock Support Failure in the Longwall Top-Coal Caving Faces: A Case Study in Datong Coalfield, China

    Directory of Open Access Journals (Sweden)

    Zhu Li

    2018-01-01

    Full Text Available Longwall chock support failures seriously restrain the safety and high-efficiency of mining of extra thick coal seams, as well as causing a great waste of coal resources. During longwall top-coal caving (LTCC, the influential effect of the properties and the movement regulation of top-coal on strata behavior cannot be ignored, since the top-coal is the medium through which the load of the overlying strata is transferred to the chock supports. Taking Datong coalfield as an example, the mechanism of a chock support failure in the LTCC face was investigated. Research findings indicated that the hard top-coal and insufficient chock support capacity were primary reasons for chock support failure accidents. On account of the field-measured results, a new method to determine support capacity was proposed, which fully took the impact of the top-coal strength into consideration. The calculation revealed that the required support capacity had exceeded the existing production maximum, at about 22,000 KN. Since it was unrealistic to simply increase chock support capacity, other approaches, according to the theoretical analysis, were proposed, such as lowering the integrity and strength of the top-coal, and upgrading its crushing effect to weaken the support load effectively during the weighting period, which reduces the likelihood of chock support accidents occurring. Based on this, hydraulic fracturing for hard top-coal and optimization of the caving process (chock supports raised up and down repeatedly by manual operation before moving forward were presented. The proposed solutions were successfully applied in LTCC-west8101 for subsequent mining and achieved substantial benefits. The above research provides valuable references and ideas for the control of strata behavior to ensure safe and highly efficient mining in extremely thick and hard coal seams with the LTCC method.

  8. Mechanism and Prevention of a Chock Support Failure in the Longwall Top-Coal Caving Faces: A Case Study in Datong Coalfield, China

    OpenAIRE

    Zhu Li; Jialin Xu; Shengchao Yu; Jinfeng Ju; Jingmin Xu

    2018-01-01

    Longwall chock support failures seriously restrain the safety and high-efficiency of mining of extra thick coal seams, as well as causing a great waste of coal resources. During longwall top-coal caving (LTCC), the influential effect of the properties and the movement regulation of top-coal on strata behavior cannot be ignored, since the top-coal is the medium through which the load of the overlying strata is transferred to the chock supports. Taking Datong coalfield as an example, the mechan...

  9. Failure criteria for viscoelastic materials

    Science.gov (United States)

    Knauss, W. G.

    1974-01-01

    Research projects concerned with developing a theory of fracture of materials are discussed. The effects of the geometry of the structure and the loads acting on the structure as they influence the failure process are analyzed. The effects of the viscoelastic deformation characteristics of the bulk elastomer on failure behavior are examined. Additional material parameters which control the fracture process are identified.

  10. The Structure of Policy Networks for Injury and Violence Prevention in 15 US Cities

    Science.gov (United States)

    Jonson-Reid, Melissa; Carothers, Bobbi J.; Fowler, Patrick

    2017-01-01

    Objectives: Changes in policy can reduce violence and injury; however, little is known about how partnerships among organizations influence policy development, adoption, and implementation. To understand partnerships among organizations working on injury and violence prevention (IVP) policy, we examined IVP policy networks in 15 large US cities. Methods: In summer 2014, we recruited 15 local health departments (LHDs) to participate in the study. They identified an average of 28.9 local partners (SD = 10.2) working on IVP policy. In late 2014, we sent survey questionnaires to 434 organizations, including the 15 LHDs and their local partners, about their partnerships and the importance of each organization to local IVP policy efforts; 319 participated. We used network methods to examine the composition and structure of the policy networks. Results: Each IVP policy network included the LHD and an average of 21.3 (SD = 6.9) local partners. On average, nonprofit organizations constituted 50.7% of networks, followed by government agencies (26.3%), schools and universities (11.8%), coalitions (11.2%), voluntary organizations (9.6%), hospitals (8.5%), foundations (2.2%), and for-profit organizations (0.7%). Government agencies were perceived as important by the highest proportion of partners. Perceived importance was significantly associated with forming partnerships in most networks; odds ratios ranged from 1.07 (95% CI, 1.02-1.13) to 2.35 (95% CI, 1.68-3.28). Organization type was significantly associated with partnership formation in most networks after controlling for an organization’s importance to the network. Conclusions: Several strategies could strengthen local IVP policy networks, including (1) developing connections with partners from sectors that are not well integrated into the networks and (2) encouraging indirect or less formal connections with important but missing partners and partner types. PMID:28426291

  11. Structuring and validating a cost-effectiveness model of primary asthma prevention amongst children

    NARCIS (Netherlands)

    Ramos, G. Feljandro P.; Kuiper, Sandra; Dompeling, Edward; van Asselt, Antoinette D. I.; de Grauw, Wim J. C.; Knottnerus, J. Andre; van Schayck, Onno C. P.; Schermer, Tjard R. J.; Severens, Johan L.

    2011-01-01

    Background: Given the rising number of asthma cases and the increasing costs of health care, prevention may be the best cure. Decisions regarding the implementation of prevention programmes in general and choosing between unifaceted and multifaceted strategies in particular are urgently needed.

  12. Network Structural Influences on the Adoption of Evidence-Based Prevention in Communities

    Science.gov (United States)

    Fujimoto, Kayo; Valente, Thomas W.; Pentz, Mary Ann

    2009-01-01

    This study examined the impact of key variables in coalition communication networks, centralization and density, on the adoption of evidence-based substance abuse prevention. Data were drawn from a network survey and a corresponding community leader survey that measured leader attitudes and practices toward substance abuse prevention programs. Two…

  13. Research on the Structure, Quality and Measures to Prevent and Combat Soil Erosion in the Village Stejaru from Teleorman County

    Directory of Open Access Journals (Sweden)

    Dana Popa

    2011-10-01

    Full Text Available This study is part of a research project on the influence of agro-livestock activities on surface water quality inTeleorman County. The paper presents structure, quality and measures to prevent and combat soil erosion in relationto agro-livestock activities in this area. The paper presents structure, quality and measures to prevent and combat soilerosion in relation to agro-livestock activities in this area. The research has been done in the whole locality, and tooksoil samples to determine the type and soil texture and soil supply status with major nutrients (N, P, K. Based onthese results and knowing the types of main crops and livestock structure, at Stejaru level, recommendations weremade about avoiding the risks of pollution of surface water by nitrates from agricultural and livestock activities.

  14. Testicular failure

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/000395.htm Testicular failure To use the sharing features on this page, ... Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also ...

  15. Students at risk of educational exclusion in secondary education. Perceptions of teachers involved in special programs about prevention of school failure

    Directory of Open Access Journals (Sweden)

    Francisco Javier AMORES FERNÁNDEZ

    2016-06-01

    Full Text Available School failure in Secondary Education is one of the most serious problems that carries the Spanish educational system today. Initial vocational qualification programs (pcpi were designed to offer a second chance to failed students (or at risk of educational exclusion in this educational stage. This study, for which has been used a mixed or hybrid method research, has provided a number of results that offer a more complete vision on the usefulness of these «Educational reclosing» programs (now Vocational Basic Training, in the centers of the province of Granada, showing viewpoints as interesting as the teachers and students involved in the study. Here the perception of teachers is summarized on these students at risk who, due to several reasons, have been excluded from the mainstream educational system, and doomed to failure. Students that fail not only for learning difficulties or personal problems related to their family, also crash into an educational system that has not been able to provide adequate answers to their needs. 

  16. Hydronephrosis and renal failure following inadequate management of neuropathic bladder in a patient with spinal cord injury: Case report of a preventable complication

    Directory of Open Access Journals (Sweden)

    Vaidyanathan Subramanian

    2012-09-01

    Full Text Available Abstract Background Condom catheters are indicated in spinal cord injury patients in whom intravesical pressures during storage and voiding are safe. Unmonitored use of penile sheath drainage can lead to serious complications. Case report A 32-year old, male person, sustained complete paraplegia at T-11 level in 1985. He had been using condom catheter. Eleven years after sustaining spinal injury, intravenous urography showed no radio-opaque calculus, normal appearances of kidneys, ureters and bladder. Blood urea and Creatinine were within reference range. A year later, urodynamics revealed detrusor pressure of 100 cm water when detrusor contraction was initiated by suprapubic tapping. This patient was advised intermittent catheterisation and take anti-cholinergic drug orally; but, he wished to continue penile sheath drainage. Nine years later, this patient developed bilateral hydronephrosis and renal failure. Indwelling urethral catheter drainage was established. Five months later, ultrasound examination of urinary tract revealed normal kidneys with no evidence of hydronephrosis. Conclusion Spinal cord injury patients with high intravesical pressure should not have penile sheath drainage as these patients are at risk for developing hydronephrosis and renal failure. Intermittent catheterisation along with antimuscarinic drug should be the preferred option for managing neuropathic bladder.

  17. Buckling failures in insect exoskeletons.

    Science.gov (United States)

    Parle, Eoin; Herbaj, Simona; Sheils, Fiona; Larmon, Hannah; Taylor, David

    2015-12-17

    Thin walled tubes are often used for load-bearing structures, in nature and in engineering, because they offer good resistance to bending and torsion at relatively low weight. However, when loaded in bending they are prone to failure by buckling. It is difficult to predict the loading conditions which cause buckling, especially for tubes whose cross sections are not simple shapes. Insights into buckling prevention might be gained by studying this phenomenon in the exoskeletons of insects and other arthropods. We investigated the leg segments (tibiae) of five different insects: the locust (Schistocerca gergaria), American cockroach (Periplaneta americana), death's head cockroach (Blaberus discoidalis), stick insect (Parapachymorpha zomproi) and bumblebee (Bombus terrestris audax). These were tested to failure in cantilever bending and modelled using finite element analysis (FEA). The tibiae of the locust and the cockroaches were found to be approximately circular in shape. Their buckling loads were well predicted by linear elastic FEA, and also by one of the analytical solutions available in the literature for elastic buckling. The legs of the stick insect are also circular in cross section but have several prominent longitudinal ridges. We hypothesised that these ridges might protect the legs against buckling but we found that this was not the case: the loads necessary for elastic buckling were not reached in practice because yield occurred in the material, causing plastic buckling. The legs of bees have a non-circular cross section due to a pollen-carrying feature (the corbicula). We found that this did not significantly affect their resistance to buckling. Our results imply that buckling is the dominant failure mode in the tibia of insects; it likely to be a significant consideration for other arthropods and any organisms with stiff exoskeletons. The interactions displayed here between material properties and cross sectional geometry may provide insights for the

  18. Kidney Failure

    Science.gov (United States)

    ... The Hope Affair A Pairing for Prevention - Boston Classical Music For a Cause A Pairing for Prevention - ... kidney Financial Assistance Kidney patient assistance HelpLine Grants Management System (GMS) login Education & Research Patient Webinars Become ...

  19. Perioperative acute renal failure.

    LENUS (Irish Health Repository)

    Mahon, Padraig

    2012-02-03

    PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

  20. Prevention of pulmonary vascular and myocardial remodeling by the combined tyrosine and serine-/threonine kinase inhibitor, sorafenib, in pulmonary hypertension and right heart failure

    Directory of Open Access Journals (Sweden)

    M. Klein

    2008-06-01

    Full Text Available Inhibition of tyrosine kinases can reverse pulmonary hypertension but little is known about the role of serine-/threonine kinases in vascular and myocardial remodeling. We investigated the effects of sorafenib, an inhibitor of the tyrosine kinases VEGFR, PDGFR and c-kit as well as the serine-/threonine kinase Raf-1, in pulmonary hypertension and right ventricular (RV pressure overload. In monocrotaline treated rats, sorafenib (10 mg·kg–1·d–1 p.o. reduced pulmonary arterial pressure, pulmonary artery muscularization and RV hypertrophy, and improved systemic hemodynamics (table 1. Sorafenib prevented phosphorylation of Raf-1 and suppressed activation of downstream signaling pathways (Erk 1/2. After pulmonary banding, sorafenib, but not the PDGFR/c-KIT/ABL-inhibitor imatinib reduced RV mass and RV filling pressure significantly. Congruent with these results, sorafenib only prevented ERK phosphorylation and vasopressin induced hypertrophy of the cardiomyocyte cell line H9c2 dose dependently (IC50 = 300 nM. Combined inhibition of tyrosine and serine-/threonine kinases by sorafenib prevents vascular and cardiac remodeling in pulmonary hypertension, which is partly mediated via inhibition of the Raf kinase pathway.

  1. Relation of mechanical dyssynchrony with underlying cardiac structure and performance in chronic systolic heart failure: implications on clinical response to cardiac resynchronization.

    Science.gov (United States)

    Tang, Wai Hong Wilson; Mullens, Wilfried; Borowski, Allen G; Tong, Wilson; Shrestha, Kevin; Troughton, Richard W; Martin, Maureen G; Kassimatis, Kathleen; Agler, Debbie; Jasper, Sue; Grimm, Richard A; Starling, Randall C; Klein, Allan L

    2008-12-01

    The aim of this study is to describe the relationship between ventricular mechanical dyssynchrony (VMD) and echocardiographic indices of cardiac remodelling. We evaluated 219 ambulatory patients with chronic systolic heart failure [left ventricular ejection fraction (LVEF) Heart Association functional classes II-IV] who underwent echocardiographic evaluation. The presence of dyssynchrony was defined by Bader criteria (intra-VMD > 40 ms and/or inter-VMD > 38 ms). In our study cohort, 59% of patients had evidence of dyssynchrony (including 44% with intra-VMD and 38% with inter-VMD, and 20% with both). Inter-VMD correlated with QRS width (r = 0.48, P chronic systolic heart failure, evidence of mechanical dyssynchrony is prevalent but the underlying cardiac structure and performance may influence the degree of inter-VMD more so than intra-VMD. Our data suggest that the extent of inter-VMD is directly related to the degree of dilatation of the heart but inversely to diastolic dysfunction.

  2. Experimental heart failure causes depression-like behavior together with differential regulation of inflammatory and structural genes in the brain

    Directory of Open Access Journals (Sweden)

    Anna eFrey

    2014-10-01

    Full Text Available Background-Depression and anxiety are common and independent outcome predictors in patients with chronic heart failure (CHF. However, it is unclear whether CHF causes depression. Thus, we investigated whether mice develop anxiety- and depression-like behavior after induction of ischemic CHF by myocardial infarction (MI.Methods and Results- In order to assess depression-like behavior, anhedonia was investigated by repeatedly testing sucrose preference for 8 weeks after coronary artery ligation or sham operation. Mice with large MI and increased left ventricular dimensions on echocardiography (termed CHF mice showed reduced preference for sucrose, indicating depression-like behavior. 6 weeks after MI, mice were tested for exploratory activity, anxiety-like behavior and cognitive function using the elevated plus maze (EPM, light-dark box (LDB, open field (OF and object recognition (OR tests. In the EPM and OF, CHF mice exhibited diminished exploratory behavior and motivation despite similar movement capability. In the OR, CHF mice had reduced preference for novelty and impaired short-term memory. On histology, CHF mice had unaltered overall cerebral morphology. However, analysis of gene expression by RNA-sequencing in prefrontal cortical, hippocampal, and left ventricular tissue revealed changes in genes related to inflammation and cofactors of neuronal signal transduction in CHF mice, with Nr4a1 being dysregulated both in prefrontal cortex and myocardium after MI. Conclusions-After induction of ischemic CHF, mice exhibited anhedonic behavior, decreased exploratory activity and interest in novelty, and cognitive impairment. Thus, ischemic CHF leads to distinct behavioral changes in mice analogous to symptoms observed in humans with CHF and comorbid depression.

  3. The use of structural equation modeling in generative research: toward the design of a preventive intervention for bereaved children.

    Science.gov (United States)

    West, S G; Sandler, I; Pillow, D R; Baca, L; Gersten, J C

    1991-08-01

    Describes a generative study of processes which may lead to symptomatology in children who have experienced the death of a parent. Based on existing literature, four putative mediating variables were identified: parental demoralization, family warmth, negative family events, and positive stable family events. Structural equation modeling techniques were used to compare several potential causal models involving these variables. The results were most consistent with a model in which bereavement was not directly related to the child symptomatology, but rather its effects were transmitted through these four mediational mechanisms. The implications of the results of the structural modeling for the design and evaluation of preventive interventions are discussed briefly.

  4. Contraceptive failure

    DEFF Research Database (Denmark)

    Rasch, Vibeke

    2002-01-01

    , and 2614 received antenatal care. The variables studied comprise age, partner relationship, number of births, occupational and economical situation, and contraceptive use.Contraceptive failure, defined as contraceptive use (condom, diaphragm, IUD, oral contraception, or another modern method...... to use of condom and oral contraception than women aged 25-34 years. In addition, contraceptive failure was found to be associated with being single, a student, and having given birth twice or more previously. Regarding pregnancy acceptance, being 25-34 years of age was positively associated, whereas...

  5. Where indigenous water management practices overcome failures of structures: The Wadi Laba spate irrigation system in Eritrea

    NARCIS (Netherlands)

    Mehari, A.H.; Schultz, E.; Depeweg, H.

    2005-01-01

    The only source of irrigation water in the Wadi Laba (ephemeral stream) spate irrigation system is the flood, which is highly unpredictable in occurrence and amount. It frequently damages the brushwood and indigenous earthen structures, locally known as agims and musghas, making (re)construction and

  6. The Correlation of PPARα Activity and Cardiomyocyte Metabolism and Structure in Idiopathic Dilated Cardiomyopathy during Heart Failure Progression

    Directory of Open Access Journals (Sweden)

    E. Czarnowska

    2016-01-01

    Full Text Available This study aimed to define relationship between PPARα expression and metabolic-structural characteristics during HF progression in hearts with DCM phenotype. Tissue endomyocardial biopsy samples divided into three groups according to LVEF ((I 45–50%, n=10; (II 30–40%, n=15; (III 60%, n=6 were investigated. The PPARα mRNA expression in the failing hearts was low in Group (I, high in Group (II, and comparable to that of the control in Group (III. There were analogous changes in the expression of FAT/CD36 and CPT-1 mRNA in contrast to continuous overexpression of GLUT-4 mRNA and significant increase of PDK-4 mRNA in Group (II. In addition, significant structural changes of cardiomyocytes with glycogen accumulation were accompanied by increased expression of PPARα. For the entire study population with HF levels of FAT/CD36 mRNA showed a strong tendency of negative correlation with LVEF. In conclusion, PPARα elevated levels may be a direct cause of adverse remodeling, both metabolic and structural. Thus, there is limited time window for therapy modulating cardiac metabolism and protecting cardiomyocyte structure in failing heart.

  7. A Tailored Approach to Launch Community Coalitions Focused on Achieving Structural Changes: Lessons Learned from a HIV Prevention Mobilization Study

    Science.gov (United States)

    Chutuape, Kate S.; Willard, Nancy; Walker, Bendu C.; Boyer, Cherrie B.; Ellen, Jonathan

    2014-01-01

    Public health HIV prevention efforts have begun to focus on addressing social and structural factors contributing to HIV risk, such as unstable housing, unemployment and access to healthcare. With a limited body of evidence-based structural interventions for HIV, communities tasked with developing structural changes need a defined process to clarify their purpose and goals. This paper describes the adaptations made to a coalition development model with the purpose of improving the start-up phase for a second group of coalitions. Modifications focused on preparing coalitions to more efficiently apply structural change concepts to their strategic planning activities, create more objectives that met study goals, and enhance coalition procedures, such as building distributed coalition leadership, to better support the mobilization process. We report on primary modifications to the process, findings for the coalitions and recommendations for public health practitioners that are seeking to start a similar coalition. PMID:26785397

  8. Failure Atlas for Rolling Bearings in Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Tallian, T. E.

    2006-01-01

    This Atlas is structured as a supplement to the book: T.E. Tallian: Failure Atlas for Hertz Contact Machine Elements, 2nd edition, ASME Press New York, (1999). The content of the atlas comprises plate pages from the book that contain bearing failure images, application data, and descriptions of failure mode, image, and suspected failure causes. Rolling bearings are a critical component of the mainshaft system, gearbox and generator in the rapidly developing technology of power generating wind turbines. The demands for long service life are stringent; the design load, speed and temperature regimes are demanding and the environmental conditions including weather, contamination, impediments to monitoring and maintenance are often unfavorable. As a result, experience has shown that the rolling bearings are prone to a variety of failure modes that may prevent achievement of design lives. Morphological failure diagnosis is extensively used in the failure analysis and improvement of bearing operation. Accumulated experience shows that the failure appearance and mode of failure causation in wind turbine bearings has many distinguishing features. The present Atlas is a first effort to collect an interpreted database of specifically wind turbine related rolling bearing failures and make it widely available. This Atlas is structured as a supplement to the book: T. E. Tallian: Failure Atlas for Hertz Contact Machine Elements, 2d edition, ASME Press New York, (1999). The main body of that book is a comprehensive collection of self-contained pages called Plates, containing failure images, bearing and application data, and three descriptions: failure mode, image and suspected failure causes. The Plates are sorted by main failure mode into chapters. Each chapter is preceded by a general technical discussion of the failure mode, its appearance and causes. The Plates part is supplemented by an introductory part, describing the appearance classification and failure classification

  9. Renal Failure Prevalence in Poisoned Patients

    OpenAIRE

    Arefi, Mohammad; Taghaddosinejad, Fakhroddin; Salamaty, Peyman; Soroosh, Davood; Ashraf, Hami; Ebrahimi, Mohsen

    2014-01-01

    Background: Renal failure is an important adverse effect of drug poisoning. Determining the prevalence and etiology of this serious side effect could help us find appropriate strategies for the prevention of renal failure in most affected patients. Objectives: The present study is aimed to identify drugs that induce renal failure and also to find the prevalence of renal failure in patients referred to emergency departments with the chief complaint of drug poisoning, in order to plan better th...

  10. Analysis of failures in concrete containments

    International Nuclear Information System (INIS)

    Moreno-Gonzalez, A.

    1989-09-01

    The function of Containment, in an accident event, is to avoid the release of radioactive substances into the surroundings. Containment failure, therefore, is defined as the appearance of leak paths to the external environment. These leak paths may appear either as a result of loss of leaktightness due to degradation of design conditions or structural failure with containment material break. This document is a survey of the state of the art of Containment Failure Analysis. It gives a detailed description of all failure mechanisms, indicating all the possible failure modes and their causes, right from failure resulting from degradation of the materials to structural failure and linear breake failure. Following the description of failure modes, possible failure criteria are identified, with special emphasis on structural failure criteria. These criteria have been obtained not only from existing codes but also from the latest experimental results. A chapter has been dedicated exclusively to failure criteria in conventional structures, for the purpose of evaluating the possibility of application to the case of containment. As the structural behaviour of the containment building is very complex, it is not possible to define failure through a single parameter. It is therefore advisable to define a methodology for containment failure analysis which could be applied to a particular containment. This methodology should include prevailing load and material conditions together with the behaviour of complex conditions such as the liner-anchorage-cracked concrete interaction

  11. Damage preventing measures for wind turbines. Phase 1- Reliability data

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Fredrik; Eriksson, Emil; Dahlberg, Magnus

    2010-08-15

    The state of existing reliability and failure data in the public sources has been investigated. The prime goal has been to evaluate the data's usefulness for developing damage preventing measures. Some publicly available databases exist, and the data has been presented in several papers in the literature. The results from the investigation can seem quite negative. Detailed data are lacking and the level of detailed reporting has even been decreasing in recent years. Information on the impact of load condition on failures, which is an important question, are lacking throughout in the statistics. Some components dominate the failure statistics. These are for example the gearboxes, where failures lead to long down times. Failures of the electrical system lead to considerably shorter down times but the failure rate is much higher. Severe rotor failures seem to be rare, but they occur and the consequences can be dramatic. Operators and insurance companies are demanding improved insight in damage collection, maintenance and overall damage preventing measures. Closer cooperation with these parties could be a fruitful way of gathering more useful data. Improvements for future databases are suggested. A structure for damage collection is proposed. Comparing experience of damage preventing measures from other industries, knowledge about the nature of the damage mechanism and current practice in the wind industry will be an important tool in the evaluation of different damage preventing measures. This will be done in the following phases of this project

  12. Experimental and Numerical Analyses of Dynamic Deformation and Failure in Marine Structures Subjected to Underwater Impulsive Loads

    Science.gov (United States)

    2012-08-01

    M.Y. He, and A.G. Evans, Application of a dynamic constitutive law to multilayer metallic sandwich panels subject to impulsive loads. Journal of...Impulsive Loads. 9th International Conference on Sandwich Structures, ICSS9, 2010. 146 93. Wadley, H., et al., Compressive response of multilayered ... extrusions . International Journal of Crashworthiness, 2004. 9(5): p. 449-463. 103. D’Alembert, J.R., Recherches sur la courbe que forme une corde tenduë

  13. Parameter Identification of Piecewise Linear Plasticity Metal Models Used in Numerical Modeling of Structures Under Plastic Deformation and Failure

    OpenAIRE

    A. V. Shmeliov; A. G. Kononov; A. V. Omelusik

    2016-01-01

    The article describes the models of metallic materials used in the calculation of deformation and destruction of engineering structures. The reliability of material models can adequately assess the strength characteristics of the designs of new technology in its designing and certification.The article deals with contingencies and true mechanical properties of materials and presents equations of their relationship. It notes that in the software systems mechanical characteristics of materials a...

  14. Reproductive Failure

    African Journals Online (AJOL)

    The need for the establishment of a Reproductive Failure. Clinic at Groote Schuur Hospital was considered long overdue, as it was felt that there were a number of high risk pregnancies continually being lost among the large volume of pregnant women attending the routine, busy and overcrowded antenatal clinics,. Various ...

  15. Failure Modes

    DEFF Research Database (Denmark)

    Jakobsen, K. P.; Burcharth, H. F.; Ibsen, Lars Bo

    1999-01-01

    The present appendix contains the derivation of ten different limit state equations divided on three different failure modes. Five of the limit state equations can be used independently of the characteristics of the subsoil, whereas the remaining five can be used for either drained or undrained...

  16. A Covariance Structure Model Test of Antecedents of Adolescent Alcohol Misuse and a Prevention Effort.

    Science.gov (United States)

    Dielman, T. E.; And Others

    1989-01-01

    Questionnaires were administered to 4,157 junior high school students to determine levels of alcohol misuse, exposure to peer use and misuse of alcohol, susceptibility to peer pressure, internal health locus of control, and self-esteem. Conceptual model of antecendents of adolescent alcohol misuse and effectiveness of a prevention effort was…

  17. Prevention of calcium-induced membrane structural alterations in erythrocyte membranes by flunarizine

    NARCIS (Netherlands)

    Thomas, Peter G.; Zimmermann, A.G.; Verkleij, A.J.

    1988-01-01

    The calcium antagonist flunarizine is shown to be able to prevent particle aggregation, membrane aggregation and blebbing resulting from elevated calcium concentrations. The anti-ischemic effects of flunarizine may therefore result in part from its ability to directly interfere with calcium-membrane

  18. Stress-induced structural remodeling in hippocampus: Prevention by lithium treatment

    Science.gov (United States)

    Wood, Gwendolyn E.; Young, L. Trevor; Reagan, Lawrence P.; Chen, Biao; McEwen, Bruce S.

    2004-03-01

    Chronic restraint stress, psychosocial stress, as well as systemic or oral administration of the stress-hormone corticosterone induces a morphological reorganization in the rat hippocampus, in which adrenal steroids and excitatory amino acids mediate a reversible remodeling of apical dendrites on CA3 pyramidal cell neurons of the hippocampus. This stress-induced neuronal remodeling is accompanied also by behavioral changes, some of which can be prevented with selective antidepressant and anticonvulsive drug treatments. Lithium is an effective treatment for mood disorders and has neuroprotective effects, which may contribute to its therapeutic properties. Thus, we wanted to determine whether lithium treatment could prevent the effects of chronic stress on CA3 pyramidal cell neuroarchitecture and the associated molecular and behavioral measures. Chronic lithium treatment prevented the stress-induced decrease in dendritic length, as well as the stress-induced increase in glial glutamate transporter 1 (GLT-1) mRNA expression and the phosphorylation of cAMP-response element binding in the hippocampus. Lithium treatment, however, did not prevent stress effects on behavior in the open field or the plus-maze. These data demonstrate that chronic treatment with lithium can protect the hippocampus from potentially deleterious effects of chronic stress on glutamatergic activation, which may be relevant to its therapeutic efficacy in the treatment of major depressive disorder and bipolar disorder.

  19. A simple approach to modeling ductile failure.

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Gerald William

    2012-06-01

    Sandia National Laboratories has the need to predict the behavior of structures after the occurrence of an initial failure. In some cases determining the extent of failure, beyond initiation, is required, while in a few cases the initial failure is a design feature used to tailor the subsequent load paths. In either case, the ability to numerically simulate the initiation and propagation of failures is a highly desired capability. This document describes one approach to the simulation of failure initiation and propagation.

  20. New Business Structures Creating Organizational Opportunities and Challenges for Work Disability Prevention.

    Science.gov (United States)

    Ekberg, Kerstin; Pransky, Glenn S; Besen, Elyssa; Fassier, Jean-Baptise; Feuerstein, Michael; Munir, Fehmidah; Blanck, Peter

    2016-12-01

    Purpose Flexible work arrangements are growing in order to develop resource-efficient production and because of advanced technologies, new societal values, changing demographics, and globalization. The article aims to illustrate the emerging challenges and opportunities for work disability prevention efforts among workers in alternate work arrangements. Methods The authors participated in a year-long collaboration that ultimately led to an invited 3-day conference, "Improving Research of Employer Practices to Prevent Disability," held October 14-16, 2015, in Hopkinton, Massachusetts, USA. The collaboration included a topical review of the literature, group conference calls to identify key areas and challenges, drafting of initial documents, review of industry publications, and a conference presentation that included feedback from peer researchers and a roundtable discussion with experts having direct employer experience. Results Both worker and employer perspectives were considered, and four common alternate work arrangements were identified: (a) temporary and contingent employment; (b) small workplaces; (c) virtual work/telework; and (d) lone workers. There was sparse available research of return-to-work (RTW) and workplace disability management strategies with regard to alternate work patterns. Limited research findings and a review of the grey literature suggested that regulations and guidelines concerning disabled workers are often ambiguous, leading to unsatisfactory protection. At the workplace level, there was a lack of research evidence on how flexible work arrangements could be handled or leveraged to support RTW and prevent disability. Potential negative consequences of this lack of organizational guidance and information are higher costs for employers and insurers and feelings of job insecurity, lack of social support and integration, or work intensification for disabled workers. Conclusions Future studies of RTW and workplace disability prevention

  1. Stabilizing two IgG1 monoclonal antibodies by surfactants: Balance between aggregation prevention and structure perturbation.

    Science.gov (United States)

    Wang, Shujing; Wu, Guoliang; Zhang, Xinyi; Tian, Zhou; Zhang, Ning; Hu, Tao; Dai, Weiguo; Qian, Feng

    2017-05-01

    Surfactants are widely used as stabilizers in the biopharmaceutical formulations to minimize protein aggregation. Under a fixed stress condition, the protecting and destabilizing effects of surfactants are hypothesized to be highly dependent on the species and concentrations of surfactants and mAb. Therefore, we here studied the aggregation-prevention and structure-perturbation effects of eight commonly used surfactants (Tw20, Tw80, Brij35, Chaps, TrX-100, SDS, Pluronic F68 and F127) on two IgG1 solution formulations under agitation, using analytical methodologies including visual inspection, OD 350 measurement, HPLC-SEC, circular dicroism, fluorescence spectroscopy and differential scanning calorimetry. We found that: (1) With concentrations range from 0.02 to 2mg/mL, nonionic surfactants were found to offer efficient aggregation-prevention effect, which is superior than the ionic surfactants; and higher surfactant concentration prevented mAb aggregation better especially under prolonged stability test under stress conditions. (2) The surfactant induced structure-perturbation emerged when even higher surfactant concentration (≥2mg/mL) was used, and such effect was surfactant-property dependent; and (3) the two IgG1 demonstrated different aggregation mechanisms and surfactant dependency, especially at high mAb concentrations. In conclusion, surfactants usage in mAb formulations, including the types and concentrations, should strike an optimal balance between the desirable aggregation-prevention and the detrimental structure-perturbation effects, while the consideration of mAb aggregation mechanism and concentration is also required for surfactant assessment. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Age-related changes in the structural parameters of the heart and myocardial remodeling in chronic heart failure in women with overweight and obesity

    Directory of Open Access Journals (Sweden)

    P. P. Bidzilya

    2015-10-01

    Full Text Available According to different authors, the representation of women in the structure of chronic heart failure (CHF ranges from 50% to 60%, however, in clinical studies the number of participants in the female reaches only 20–30%. Aim. To study age-related changes in the structural parameters of the heart and myocardial remodeling in CHF. 216 women of different age groups who have had CHF I–III functional class on the background of normal, overweight and abdominal obesity I–III degree were examined. Methods and results. Structural parameters of the heart and the condition of cardiac remodeling were estimated with echocardiography. Found that in CHF in women with overweight and obesity with age increasing is a more significant dilatation of cardiac chambers, myocardial hypertrophy of the left ventricle and the calcination of valve apparatus. In most cases myocardial remodeling were presented by concentric hypertrophy of the left ventricle. Conclusion. This demonstrates negative impact of increasing age on the restructuring of the heart in conditions of CHF in women with overweight and obesity.

  3. Examining brain structures associated with the motive to achieve success and the motive to avoid failure: A voxel-based morphometry study.

    Science.gov (United States)

    Ming, Dan; Chen, Qunlin; Yang, Wenjing; Chen, Rui; Wei, Dongtao; Li, Wenfu; Qiu, Jiang; Xu, Zhan; Zhang, Qinglin

    2016-01-01

    The motive to achieve success (MAS) and motive to avoid failure (MAF) are two different but classical kinds of achievement motivation. Though many functional magnetic resonance imaging studies have explored functional activation in motivation-related conditions, research has been silent as to the brain structures associated with individual differences in achievement motivation, especially with respect to MAS and MAF. In this study, the voxel-based morphometry method was used to uncover focal differences in brain structures related to MAS and MAF measured by the Mehrabian Achieving Tendency Scale in 353 healthy young Chinese adults. The results showed that the brain structures associated with individual differences in MAS and MAF were distinct. MAS was negatively correlated with regional gray matter volume (rGMV) in the medial prefrontal cortex (mPFC)/orbitofrontal cortex while MAF was negatively correlated with rGMV in the mPFC/subgenual cingulate gyrus. After controlling for mutual influences of MAS and MAF scores, MAS scores were found to be related to rGMV in the mPFC/orbitofrontal cortex and another cluster containing the parahippocampal gyrus and precuneus. These results may predict that compared with MAF, the generation process of MAS may be more complex and rational, thus in the real world, perhaps MAS is more beneficial to personal growth and guaranteeing the quality of task performance.

  4. Kidney (Renal) Failure

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Kidney Failure Kidney failure, also known as renal failure, is ... is kidney failure treated? What is kidney (renal) failure? The kidneys are designed to maintain proper fluid ...

  5. Omega-3 Polyunsaturated Fatty Acid Supplementation to Prevent Arteriovenous Fistula and Graft Failure: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Viecelli, Andrea K; Irish, Ashley B; Polkinghorne, Kevan R; Hawley, Carmel M; Johnson, David W; Mori, Trevor A; Pascoe, Elaine M; Strippoli, Giovanni F M; Lok, Charmaine E; Palmer, Suetonia C

    2018-01-27

    Arteriovenous access failure frequently occurs in people on hemodialysis and is associated with morbidity, mortality and large healthcare expenditures. Omega-3 polyunsaturated fatty acids (omega-3 PUFA) may improve access outcomes via pleiotropic effects on access maturation and function, but may cause bleeding complications. Systematic review with meta-analysis. Adults requiring hemodialysis via arteriovenous fistula or graft. Trials evaluating omega-3 PUFA for arteriovenous access outcomes identified by searches in CENTRAL, MEDLINE, and Embase to 24 January 2017. Omega-3 PUFA. Primary patency loss, dialysis suitability failure, access abandonment, interventions to maintain patency or assist maturation, bleeding, gastrointestinal side-effects, all-cause and cardiovascular mortality, hospitalization, and treatment adherence. Treatment effects were summarized as relative risks (RR) and 95% confidence intervals (CI). Evidence was assessed using GRADE. Five eligible trials (833 participants) with a median follow-up of 12 months compared peri-operative omega-3 PUFA supplementation with placebo. One trial (n=567) evaluated treatment for fistulae and four (n=266) for grafts. Omega-3 PUFA supplementation prevented primary patency loss with moderate certainty (761 participants, RR 0.81, CI 0.68-0.98). Low quality evidence suggested, that omega-3 PUFA may have had little or no effect on dialysis suitability failure (536 participants, RR 0.95, CI 0.73-1.23), access abandonment (732 participants, RR 0.78, CI 0.59-1.03), need for interventions (732 participants, RR 0.82, CI 0.64-1.04), or all-cause mortality (799 participants, RR 0.99, CI 0.51-1.92). Bleeding risk (793 participants, RR 1.40, CI 0.78-2.49) or gastrointestinal side-effects (816 participants, RR 1.22, CI 0.64-2.34) from treatment were uncertain. There was no evidence of different treatment effects for grafts and fistulae. Small number and methodological limitations of included trials. Omega-3 PUFA supplementation

  6. Awareness structure of the people with opinion that nuclear power is effective for preventing global warming

    International Nuclear Information System (INIS)

    Fukae, Chiyokazu

    2006-01-01

    Most of people think that nuclear power generation is not effective for preventing global warming. In this research, the reason why people think so was investigated with using questionnaire survey. As a result, the misunderstanding, the thermal effluent and radioactive substance etc. produced from a nuclear plant promotes global warming, has influenced on this issue. People have negative image against nuclear power in the background of this idea. This negative image is a factor to decrease the evaluation that nuclear power is useful for preventing global warming regardless of the presence of the misunderstanding. By the fear that the accident of the nuclear plant brings the environmental destruction, people evaluate that nuclear power doesn't have the capabilities for environmental preservation. Especially young people have such awareness. It is necessary to learn energy and environmental issues including the merits and demerits of nuclear power objectively in the academic training. (author)

  7. Prophylactic Methylxanthines for Preventing Extubation Failure in the Preterm Neonates with the Gestational Age of ≤30 Weeks: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    M Shivakumar

    2017-09-01

    Full Text Available Background: Preterm neonates are at a high risk of respiratory depression at birth. Incidence of respiratory distress is reported in 60-80% of the neonates born with the gestational age of less than 28 weeks and 15-30% of the neonates with the gestational age of less than 32-34 weeks. The present study aimed to compare the incidence and risk of failed extubation in using caffeine and aminophylline in the preterm neonates with the gestational age of ≤30 weeks in the periextubation period.Methods: This single-centered, parallel, open-label, randomized controlled trial was conducted in a tertiary care referral hospital in India during June 2014-2016. Neonates with the gestational age of ≤30 weeks who were intubated for a minimum of 24 hours were enrolled in the study. Neonates with major anomalies, heart disease, and sepsis were excluded from the study. After the random allocation of the infants to treatment with the standard dose of caffeine citrate and aminophylline methylxanthine, intubation continued for seven consecutive days with or without non-invasive ventilatory support. As the primary objective, the incidence and risk of failed extubation were assessed. Secondary objective of the research was to compare the relative incidence of acute adverse effects, persistent apnea, and the associated morbidities.Results: Neonates treated by caffeine were at a higher risk of extubation failure (1.09 times adjusted with birth weight (31.5% versus 21.4%; RR=1.09; 95% CI: 0.81-1.46; P=0.55, which was not statistically significant. In addition, risk of apnea within seven days and after seven days of methylxanthine therapy was 1.57 (95% CI: 0.95-2.61 and 1.10 (95% CI: 0.95-2.61 times higher in the neonates with caffeine treatment. Also, rate of tachycardia was high in the neonates treated by aminophylline, which was statistically significant (RR=0.27; 95% CI: 0.13-0.56; P

  8. Structural Constraints on the Training of Peer Educators in Hepatitis C Prevention

    Science.gov (United States)

    Treloar, Carla; Rance, Jake; Laybutt, Becky; Crawford, Sione

    2012-01-01

    Despite advances in understanding the structural contexts in which drug use occurs and shifts beyond the individual-level focus of adult education theory, peer education models remain wedded to questions of individual behaviour. Our analysis examines the structural context of peer education and its implications for peer training. People who inject…

  9. A study on effective system depressurization during a PWR vessel bottom break LOCA with HPI failure and gas inflow prevention. ROSA-V/LSTF test SB-PV-05

    International Nuclear Information System (INIS)

    Suzuki, Mitsuhiro; Takeda, Takeshi; Asaka, Hideaki; Nakamura, Hideo

    2006-11-01

    A small break loss-of-coolant accident (SBLOCA) experiment was conducted at the Large Scale Test Facility (LSTF) of ROSA-V program to study effects of accident management (AM) measures on core cooling, which are important in case of total failure of high pressure injection (HPI) system during an SBLOCA at a pressurized water reactor (PWR). The LSTF is a full-height and 1/48 volume-scaled facility simulating a 4-loop Westinghouse-type PWR (3423 MWt). The experiment, SB-PV-05, simulated a PWR vessel bottom SBLOCA with a rupture of nine instrument tubes, which is equivalent to 0.18% cold leg break. It is clarified that AM actions with steam generator (SG) depressurization to achieve a primary loop cooling rate at -55 K/h and auxiliary feedwater supply for 30 minutes are effective to avoid core uncovery by actuating the low pressure injection (LPI) system. It is also shown through the comparison with the previous experiment of SB-PV-03 that prevention of non-condensable gas inflow from the accumulator injection system (AIS) is very important to actuate the LPI to achieve adequate core cooling. This report presents experiment results of SB-PV-05 in detail and shows the effects of gas inflow prevention on core cooling through the estimation of primary coolant mass and energy balance in the primary system. (author)

  10. Ductile failure modeling

    DEFF Research Database (Denmark)

    Benzerga, Ahmed Amine; Leblond, Jean Baptiste; Needleman, Alan

    2016-01-01

    Ductile fracture of structural metals occurs mainly by the nucleation, growth and coalescence of voids. Here an overview of continuum models for this type of failure is given. The most widely used current framework is described and its limitations discussed. Much work has focused on extending void...... growth models to account for non-spherical initial void shapes and for shape changes during growth. This includes cases of very low stress triaxiality, where the voids can close up to micro-cracks during the failure process. The void growth models have also been extended to consider the effect of plastic...... anisotropy, or the influence of nonlocal effects that bring a material size scale into the models. Often the voids are not present in the material from the beginning, and realistic nucleation models are important. The final failure process by coalescence of neighboring voids is an issue that has been given...

  11. Respiratory failure in elderly patients.

    Science.gov (United States)

    Sevransky, Jonathan E; Haponik, Edward F

    2003-02-01

    Elderly individuals comprise an increasing proportion of the population and represent a progressively expanding number of patients admitted to the ICU. Because of underlying pulmonary disease, loss of muscle mass, and other comorbid conditions, older persons are at increased risk of developing respiratory failure. Recognition of this vulnerability and the adoption of proactive measures to prevent decompensation requiring intrusive support are major priorities together with clear delineation of patients' wishes regarding the extent of support desired should clinical deterioration occur. Further, the development of coordinated approaches to identify patients at risk for respiratory failure and strategies to prevent the need for intubation, such as the use of NIV in appropriate patients, are crucial. As soon as endotracheal intubation and mechanical ventilation are implemented strategies that facilitate the liberation of elderly patients from the ventilator are especially important. The emphasis on a team approach, which characterizes geriatric medicine, is essential in coordinating the skills of multiple health care professionals in this setting. Respiratory failure can neither be effectively diagnosed nor managed in isolation. Integration with all other aspects of care is essential. Patient vulnerability to nosocomial complications and the "cascade effect" of these problems such as the effects of medications and invasive supportive procedures all impact on respiratory care of elderly patients. For example, prolonged mechanical ventilation may be required long after resolution of the underlying cause of respiratory failure because of unrecognized and untreated delirium or residual effects of small doses of sedative and/or analgesic agents or other medications in elderly patients with altered drug metabolism. The deleterious impact of the foreign and sometimes threatening ICU environment and/or sleep deprivation on the patient's course are too often overlooked because

  12. Pulmonary venous hypertension and mechanical strain stimulate monocyte chemoattractant protein-1 release and structural remodelling of the lung in human and rodent chronic heart failure models.

    Science.gov (United States)

    Park, John E S; Lyon, Alexander R; Shao, Dongmin; Hector, Lauren R; Xu, Hua; O'Gara, Peter; Pinhu, Liao; Chambers, Rachel C; Wort, S John; Griffiths, Mark J D

    2014-12-01

    The burden of chronic heart failure (HF) is rising owing to an increased survivorship after myocardial infarction (MI). Pulmonary structural remodelling in patients with HF may protect against oedema while causing dyspnoea, the predominant symptom associated with HF. The cellular and molecular mechanisms underlying these processes in HF are poorly understood. We hypothesised that pulmonary venous hypertension (PVH) following MI provides a mechanical stimulus for structural remodelling of the lung via monocyte chemoattractant protein-1 (MCP-1). Human lung microvascular endothelial cells (HLMVEC) and Ea.Hy 926 cells exposed to cyclic mechanical strain (CMS) in vitro were analysed for MCP-1 expression and activation of signalling intermediates. HF was induced in Sprague-Dawley rats 16 weeks after MI; a cohort was rescued with AAV9.SERCA2a gene therapy to reduce PVH. HLMVEC and Ea.Hy 926 cells exposed to CMS upregulated MCP-1 gene expression and protein release in an extracellular-signal-regulated kinase (ERK) 1/2 dependent manner. Supernatants from these experiments stimulated fibroblast (human fetal lung fibroblast -1) and pulmonary artery smooth muscle cell proliferation and differentiation. Total lung collagen, a marker of structural remodelling, and MCP-1 gene expression were increased in the lungs of rats with post-MI HF. SERCA2a gene therapy that attenuated PVH after MI was associated with lower levels of lung collagen and MCP-1 gene expression in the lung. Mechanical strain associated with PVH may stimulate pulmonary structural remodelling through ERK 1/2 dependent induction of MCP-1. These findings provide insights into the pathophysiology of lung remodelling in HF and highlight novel, potential therapeutic targets. 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.

  13. Structuring a college alcohol prevention program on the low level of response to alcohol model: a pilot study.

    Science.gov (United States)

    Schuckit, Marc A; Kalmijn, Jelger A; Smith, Tom L; Saunders, Gretchen; Fromme, Kim

    2012-07-01

    New approaches are needed to bolster the modest effects of campus drinking prevention programs. However, more definitive research on new paradigms is very expensive, and in the current economic climate, progress can be made by evaluating smaller pilot studies. This study describes one such approach. A sample of 18-year-old or older, healthy, drinking freshmen at our university was assigned to 2 groups stratified to be similar on demography, drinking histories, and their level of response (LR) to alcohol. In the spring quarter of the school year, the 32 subjects in each of 2 groups viewed four 45-minute Internet-based videotapes as part of 4 prevention sessions. All 8 modules were based on the same techniques and general content, but the 4 videos for the first group were structured around the validated model of how a low LR affects heavy drinking (the low level of response-based [LRB] Group), with partial mediation by heavier drinking peers, positive alcohol expectancies, and drinking to cope with stress. Videos for the state-of-the-art (SOTA) comparison group did not place the similar prevention messages into the low LR framework. Changes in drinking were evaluated at 3 times: before Module 1, before Module 4, and 1 month after Module 4. Usual and maximum drinks per occasion decreased over time for both high and low LR subjects in both LRB and SOTA groups. As predicted, the low LR students showed greater decreases in the LRB Group, while high LR students showed greater decreases in the more generic SOTA Group. The results support the hypothesis that tailoring prevention efforts to address specific predisposing factors, such as a low LR, may be associated with beneficial effects on drinking quantity. We hope that these data will encourage additional efforts to validate the low LR-based prevention paradigm and test other interventions that are targeted toward predisposing phenotypes such as impulsivity and negative affect. Copyright © 2012 by the Research Society

  14. Prevent recurrence of nuclear disaster (4). Future tasks in the field of structure and components

    International Nuclear Information System (INIS)

    Okamoto, Koji; Takagi, Toshiyuki; Ueda, Susumu

    2012-01-01

    Structure and components subcommittee under the special committee of seismic safety of nuclear power stations of the Atomic Energy Society of Japan discussed future activities related with technical problems of seismic design of structures, components and piping system and evaluation of seismic effects in collaboration with the Japan Society of Mechanical Engineers. These problems were arranged by 'logic of seismic safety' and tabulated just enough, and then their roadmap was prepared. This article described selected relevant problems and discussed safety margins of seismic design and their related problems, referring to state of countermeasures and evaluated results of nuclear power stations after Great East Japan Earthquake occurred in March 11, 2011. Main problems were related with seismic safety margins of structure and components, consideration of ground motion index, rationalization and upgrade of seismic design, application of new technology, integrity evaluation of structure and components after or at earthquake, and upgrade of seismic probabilistic risk assessment methodology. (T. Tanaka)

  15. Failure analysis of buried tanks

    International Nuclear Information System (INIS)

    Watkins, R.K.

    1994-01-01

    Failure of a buried tank can be hazardous. Failure may be a leak through which product is lost from the tank; but also through which contamination can occur. Failures are epidemic -- because buried tanks are out of sight, but also because designers of buried tanks have adopted analyses developed for pressure tanks. So why do pressure tanks fail when they are buried? Most failures of buried tanks are really soil failures. Soil compresses, or slips, or liquefies. Soil is not only a load, it is a support without which the tank deforms. A high water table adds to the load on the tank. It also reduces the strength of the soil. Based on tests, structural analyses are proposed for empty tanks buried in soils of various quality, with the water table at various levels, and with internal vacuum. Failure may be collapse tank. Such collapse is a sudden, audible inversion of the cylinder when the sidefill soil slips. Failure may be flotation. Failure may be a leak. Most leaks are fractures in the welds in overlap seams at flat spots. Flat spots are caused by a hard bedding or a heavy surface wheel load. Because the tank wall is double thick at the overlap, shearing stress in the weld is increased. Other weld failures occur when an end plate shears down past a cylinder; or when the tank is supported only at its ends like a beam. These, and other, failures can be analyzed with justifiable accuracy using basic principles of mechanics of materials. 10 figs

  16. Combinatorial analysis of systems with competing failures subject to failure isolation and propagation effects

    International Nuclear Information System (INIS)

    Xing Liudong; Levitin, Gregory

    2010-01-01

    This paper considers the reliability analysis of binary-state systems, subject to propagated failures with global effect, and failure isolation phenomena. Propagated failures with global effect are common-cause failures originated from a component of a system/subsystem causing the failure of the entire system/subsystem. Failure isolation occurs when the failure of one component (referred to as a trigger component) causes other components (referred to as dependent components) within the same system to become isolated from the system. On the one hand, failure isolation makes the isolated dependent components unusable; on the other hand, it prevents the propagation of failures originated from those dependent components. However, the failure isolation effect does not exist if failures originated in the dependent components already propagate globally before the trigger component fails. In other words, there exists a competition in the time domain between the failure of the trigger component that causes failure isolation and propagated failures originated from the dependent components. This paper presents a combinatorial method for the reliability analysis of systems subject to such competing propagated failures and failure isolation effect. Based on the total probability theorem, the proposed method is analytical, exact, and has no limitation on the type of time-to-failure distributions for the system components. An illustrative example is given to demonstrate the basics and advantages of the proposed method.

  17. Quality investigation of building structure using ground penetrating radar (GPR) as an early study to prevent severe structural damage

    Science.gov (United States)

    Gumai, M. Fariz; Fernando, Stephen; Nugroho, Gatot; Natania, Kana; Widodo

    2017-07-01

    Many infrastructures in Indonesia suffered damage in a short period of time. It proves that there are still many buildings in Indonesia which have questionable quality so a method is needed for checking the quality of the building. Ground Penetrating Radar (GPR) is a method used to describe the structure of the building on the inside that cannot be seen from the outside in this case Parahyangan Reksa Raga (PASAGA) Bridge was examined with 19.7 m × 3.3 m × 1.5 m dimension. Thismethod uses propagation of electromagnetic wave, which will give Radargram response inside a building based on the characteristics of the medium such as magnetic permeability, electric permittivity and electrical conductivity. GPR method is one of geophysical method which is effective, efficient, and environmentally friendly. The measurements were carried out using MALA RAMAC X3M device with frequency 800 MHz. The results show thatindication of fractures was found at less than 1 m depth in the structure from the Radargram display of PASAGA Bridge and supported by the observation data on the surface.

  18. Ultra Structural Characterisation of Tetherin - a Protein Capable of Preventing Viral Release from the Plasma Membrane

    Directory of Open Access Journals (Sweden)

    Ravindra K. Gupta

    2010-04-01

    Full Text Available Tetherin is an antiviral restriction factor made by mammalian cells to protect them from viral infection. It prevents newly formed virus particles from leaving infected cells. Its antiviral mechanism appears to be remarkably uncomplicated. In 2 studies published in PLoS Pathogens electron microscopy is used to support the hypothesis that the tethers that link HIV-1 virions to tetherin expressing cells contain tetherin and are likely to contain tetherin alone. They also show that the HIV-1 encoded tetherin antagonist that is known to cause tetherin degradation, Vpu, serves to reduce the amount of tetherin in the particles thereby allowing their release.

  19. What Is Threatening the Effectiveness of Insecticide-Treated Bednets? A Case-Control Study of Environmental, Behavioral, and Physical Factors Associated with Prevention Failure.

    Science.gov (United States)

    Obala, Andrew A; Mangeni, Judith Nekesa; Platt, Alyssa; Aswa, Daniel; Abel, Lucy; Namae, Jane; Prudhomme O'Meara, Wendy

    2015-01-01

    Insecticide-treated nets are the cornerstone of global malaria control and have been shown to reduce malaria morbidity by 50-60%. However, some areas are experiencing a resurgence in malaria following successful control. We describe an efficacy decay framework to understand why high malaria burden persists even under high ITN coverage in a community in western Kenya. We enrolled 442 children hospitalized with malaria and paired them with age, time, village and gender-matched controls. We completed comprehensive household and neighborhood assessments including entomological surveillance. The indicators are grouped into five domains in an efficacy decay framework: ITN ownership, compliance, physical integrity, vector susceptibility and facilitating factors. After variable selection, case-control data were analyzed using conditional logistic regression models and mosquito data were analyzed using negative binomial regression. Predictive margins were calculated from logistic regression models. Measures of ITN coverage and physical integrity were not correlated with hospitalized malaria in our study. However, consistent ITN use (Adjusted Odds Ratio (AOR) = 0.23, 95%CI: 0.12-0.43), presence of nearby larval sites (AOR = 1.137, 95%CI: 1.02-1.27), and specific types of crops (AOR (grains) = 0.446, 95%CI: 0.24-0.82) were significantly correlated with malaria amongst children who owned an ITN. The odds of hospitalization for febrile malaria nearly tripled when one other household member had symptomatic malaria infection (AOR-2.76, 95%CI:1.83-4.18). Overall, perfect household adherence could reduce the probability of hospitalization for malaria to less than 30% (95%CI:0.12-0.46) and adjusting environmental factors such as elimination of larval sites and growing grains nearby could reduce the probability of hospitalization for malaria to less than 20% (95%CI:0.04-0.31). Availability of ITNs is not the bottleneck for malaria prevention in this community. Behavior change

  20. Parameter Identification of Piecewise Linear Plasticity Metal Models Used in Numerical Modeling of Structures Under Plastic Deformation and Failure

    Directory of Open Access Journals (Sweden)

    A. V. Shmeliov

    2016-01-01

    Full Text Available The article describes the models of metallic materials used in the calculation of deformation and destruction of engineering structures. The reliability of material models can adequately assess the strength characteristics of the designs of new technology in its designing and certification.The article deals with contingencies and true mechanical properties of materials and presents equations of their relationship. It notes that in the software systems mechanical characteristics of materials are given in the true sense.The paper considers the linear and exponential models of materials, their characteristics, and methods to implement them. It considers the models of Johnson-Cook Steinberg-Guinan, Zerilli-Armstrong, Cowper-Symonds, Gurson-Tvergaard that take into account the strain rate and temperature of the material. Describes their applications, advantages and disadvantages. Considers single- and multi-parameter criteria of materials fracture, the prospects for their use. Gives a rational justification for using a piecewise linear plasticity material model *MAT_PIECEWISE_LINEAR_PLASTICITY (024, LS-DYNA software package for the engineering industry, and presents its main parameters.A technique to identify parameters of piecewise linear plasticity metal material models has been developed. The technique consists of the stages, based on the equations of transition from the conventional stress and strain values to the true ones. Taking into consideration the stressstrain state in the neck of the sample is a distinctive feature of the technique.Tensile tests of the round material samples have been conducted. To test the developed technique in the software package ANSYS LS-DYNA PC have been made tensile sample modeling and results comparison to show high convergence.Further improvement of the technique can be achieved through the development of a statistical approach to the analysis of the results of a series of tests. This will allow a kind of

  1. Heart failure - tests

    Science.gov (United States)

    CHF - tests; Congestive heart failure - tests; Cardiomyopathy - tests; HF - tests ... best test to: Identify which type of heart failure (systolic, diastolic, valvular) Monitor your heart failure and ...

  2. The Importance of Identifying Early Changes in Cardiac Structure and Function for the Prevention of Cognitive Impairment and Dementia.

    Science.gov (United States)

    Edwards, Jodi D

    2017-01-01

    Multiple cardiac pathologies have been shown to contribute to progressive cognitive decline and dementia in elderly populations, including left ventricular hypertrophy (LVH), a marker of prolonged exposure to hypertension. Although associations between chronic hypertension and cognitive function are thought to be mediated primarily by these end organ effects, there is increasing evidence that early changes in cardiac structure and function, such as LVH, may independently contribute to cognitive decline and impairment. In the current issue of the Journal of Alzheimer's Disease, Mahinrad and colleagues report important new findings on the association between LVH and cognitive function that are incremental to cardiovascular risk and co-morbidity, including hypertension. Emerging evidence that early changes in cardiac structure and function may independently contribute to cognitive decline in elderly populations has resulted in an increased interest in these preclinical substrates as potential treatment targets for the prevention of cognitive decline and in their putative contributions to the pathogenesis of dementia.

  3. Classroom Goal Structures and HIV and Pregnancy Prevention Education in Rural High School Health Classrooms

    Science.gov (United States)

    Anderman, Eric M.; Cupp, Pamela K.; Lane, Derek R.; Zimmerman, Rick; Gray, DeLeon L.; O'Connell, Ann

    2011-01-01

    Over 5,000 adolescents enrolled in required rural high school health courses reported their perceptions of mastery and extrinsic goal structures in their health classrooms. Data were collected from all students at three time points (prior to HIV and pregnancy instruction, 3 months after instruction, and 1 year after instruction). Results indicated…

  4. Failure analysis of vise jaw holders for hacksaw machine

    Directory of Open Access Journals (Sweden)

    Essam Ali Al-Bahkali

    2018-01-01

    Full Text Available Failure analysis in mechanical components has been investigated in many studies in the last few years. Failure analysis and prevention are important functions in all engineering disciplines. Materials engineers are often the lead role in the analysis of failures, where a component or product fails in service or if a failure occurs during manufacturing or production processing. In any case, one must determine the cause of the failure to prevent future occurrences and/or to improve the performance of the device, component or structure. For example, the vise jaw holders of hacksaws can break due to accidental heavy loads or machine misuse. The parts that break are the stationary and movable vise jaw holders and the connecter power screw between the holders. To investigate the failure of these components, a three-dimensional finite element model for stress analysis was performed. First, the analysis identified the broken components of the hacksaw machine. In addition, the type of materials of the broken parts was identified, a CAD model was built, and the hacksaw mechanism was analyzed to determine the accurate applied loads on the broken parts. After analyzing the model using Abaqus CAE software, the results showed that the location of the high stresses was identical with the high-stress locations in the original, broken parts. Furthermore, the power screw was subjected to a high load, which deformed the power screw. Also, the stationary vise jaw holder was broken by impact because it was not touched by the power screw until the movable vise jaw holder broke. A conclusion is drawn from the failure analysis and a way to improve the design of the broken parts is suggested.

  5. Determination of a tissue-level failure evaluation standard for rat femoral cortical bone utilizing a hybrid computational-experimental method.

    Science.gov (United States)

    Fan, Ruoxun; Liu, Jie; Jia, Zhengbin; Deng, Ying; Liu, Jun

    2018-01-01

    Macro-level failure in bone structure could be diagnosed by pain or physical examination. However, diagnosing tissue-level failure in a timely manner is challenging due to the difficulty in observing the interior mechanical environment of bone tissue. Because most fractures begin with tissue-level failure in bone tissue caused by continually applied loading, people attempt to monitor the tissue-level failure of bone and provide corresponding measures to prevent fracture. Many tissue-level mechanical parameters of bone could be predicted or measured; however, the value of the parameter may vary among different specimens belonging to a kind of bone structure even at the same age and anatomical site. These variations cause difficulty in representing tissue-level bone failure. Therefore, determining an appropriate tissue-level failure evaluation standard is necessary to represent tissue-level bone failure. In this study, the yield and failure processes of rat femoral cortical bones were primarily simulated through a hybrid computational-experimental method. Subsequently, the tissue-level strains and the ratio between tissue-level failure and yield strains in cortical bones were predicted. The results indicated that certain differences existed in tissue-level strains; however, slight variations in the ratio were observed among different cortical bones. Therefore, the ratio between tissue-level failure and yield strains for a kind of bone structure could be determined. This ratio may then be regarded as an appropriate tissue-level failure evaluation standard to represent the mechanical status of bone tissue.

  6. Manual on the Fatigue of Structures. II. Causes and Prevention of Damage. 7. Mechanical Surface Damage,

    Science.gov (United States)

    1981-06-01

    conjuguee du frottement et de la corrosion sur les aciers inoxydables. Corrosion, Vol.19, N°4, pp. 159-170, June July 1971. Archiv. Eisenhüttenwesen, Vol...National Aeronautical Meeting, New-York. 1961. Influence des conditions d’usinage par rectification sur I’etat structural et les contraintes residuelles...Contact Problems. Ph. D. Thesis. University of Minnesota, USA, 1954. Interaction entre le frottement et la corrosion. CoIIoque CEFRACOR, March 1971

  7. Superhydrophilic nanopillar-structured quartz surfaces for the prevention of biofilm formation in optical devices

    Science.gov (United States)

    Han, Soo; Ji, Seungmuk; Abdullah, Abdullah; Kim, Duckil; Lim, Hyuneui; Lee, Donghyun

    2018-01-01

    Bacterial biofilm formation on optical devices such as contact lenses, optical glasses, endoscopic devices, and microscopic slides and lenses are major concerns in the field of medicine and biomedical engineering. To solve these problems, here we present the first report of superhydrophilic transparent nanopillar-structured surfaces with bactericidal properties. To construct bactericidal surfaces, we imitated a topological mechanism found in nature in which nanopillar-structured surfaces cause a mechanical disruption of the outer cell membranes of bacteria, resulting in bacterial cell death. We used nanosphere lithography to fabricate nanopillars with various sharpnesses and heights on a quartz substrate. Water contact angle and light reflectance measurements revealed superhydrophilic, antifogging and antireflective properties, which are important for use in optical devices. To determine bactericidal efficiency, the fabricated surfaces were incubated and tested against two Gram-negative bacteria associated with biofilm formation and various diseases in humans, Pseudomonas aeruginosa and Escherichia coli. The highest bactericidal activity was achieved with nanopillars that measured 300 nm in height and 10 nm in apex diameter. Quartz substrates patterned with such nanopillars killed ∼38,000 P. aeruginosa and ∼27,000 E. coli cells cm-2 min-1, respectively. Thus, the newly designed nanopillar-structured bactericidal surfaces are suitable for use in the development of superhydrophilic and transparent optical devices.

  8. Surviving winter: Food, but not habitat structure, prevents crashes in cyclic vole populations.

    Science.gov (United States)

    Johnsen, Kaja; Boonstra, Rudy; Boutin, Stan; Devineau, Olivier; Krebs, Charles J; Andreassen, Harry P

    2017-01-01

    Vole population cycles are a major force driving boreal ecosystem dynamics in northwestern Eurasia. However, our understanding of the impact of winter on these cycles is increasingly uncertain, especially because climate change is affecting snow predictability, quality, and abundance. We examined the role of winter weather and snow conditions, the lack of suitable habitat structure during freeze-thaw periods, and the lack of sufficient food as potential causes for winter population crashes. We live-trapped bank voles Myodes glareolus on 26 plots (0.36 ha each) at two different elevations (representing different winter conditions) in southeast Norway in the winters 2013/2014 and 2014/2015. We carried out two manipulations: supplementing six plots with food to eliminate food limitation and six plots with straw to improve habitat structure and limit the effect of icing in the subnivean space. In the first winter, all bank voles survived well on all plots, whereas in the second winter voles on almost all plots went extinct except for those receiving supplemental food. Survival was highest on the feeding treatment in both winters, whereas improving habitat structure had no effect. We conclude that food limitation was a key factor in causing winter population crashes.

  9. Acute kidney failure

    Science.gov (United States)

    Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute ... Symptoms of acute kidney failure may include any of the following: Bloody stools Breath odor and metallic taste in the mouth Bruising easily Changes in ...

  10. Types of Heart Failure

    Science.gov (United States)

    ... Venous Thromboembolism Aortic Aneurysm More Types of Heart Failure Updated:May 8,2017 Left-sided heart failure ... This content was last reviewed May 2017. Heart Failure • Home • About Heart Failure Introduction Types of Heart ...

  11. Failures of chain systems

    CSIR Research Space (South Africa)

    James, A

    1997-03-01

    Full Text Available ?C and intermittent exposure at 400--450 ?C. Unlike structural steels, which become softer and more ductile when reheated in service, manga- nese steels become brittle when reheated sufficiently to induce carbide... to form a roughly oval shaped crack until the link section could no longer withstand the applied loading experienced during normal dragline operations, and this resulted in final fast brittle failure. The general...

  12. Compensation or inhibitory failure? Testing hypotheses of age-related right frontal lobe involvement in verbal memory ability using structural and diffusion MRI.

    Science.gov (United States)

    Cox, Simon R; Bastin, Mark E; Ferguson, Karen J; Allerhand, Mike; Royle, Natalie A; Maniega, Susanna Muñoz; Starr, John M; MacLullich, Alasdair M J; Wardlaw, Joanna M; Deary, Ian J; MacPherson, Sarah E

    2015-02-01

    Functional neuroimaging studies report increased right prefrontal cortex (PFC) involvement during verbal memory tasks amongst low-scoring older individuals, compared to younger controls and their higher-scoring contemporaries. Some propose that this reflects inefficient use of neural resources through failure of the left PFC to inhibit non-task-related right PFC activity, via the anterior corpus callosum (CC). For others, it indicates partial compensation - that is, the right PFC cannot completely supplement the failing neural network, but contributes positively to performance. We propose that combining structural and diffusion brain MRI can be used to test predictions from these theories which have arisen from fMRI studies. We test these hypotheses in immediate and delayed verbal memory ability amongst 90 healthy older adults of mean age 73 years. Right hippocampus and left dorsolateral prefrontal cortex (DLPFC) volumes, and fractional anisotropy (FA) in the splenium made unique contributions to verbal memory ability in the whole group. There was no significant effect of anterior callosal white matter integrity on performance. Rather, segmented linear regression indicated that right DLPFC volume was a significantly stronger positive predictor of verbal memory for lower-scorers than higher-scorers, supporting a compensatory explanation for the differential involvement of the right frontal lobe in verbal memory tasks in older age. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  13. Compensation or inhibitory failure? Testing hypotheses of age-related right frontal lobe involvement in verbal memory ability using structural and diffusion MRI

    Science.gov (United States)

    Cox, Simon R.; Bastin, Mark E.; Ferguson, Karen J.; Allerhand, Mike; Royle, Natalie A.; Maniega, Susanna Muñoz; Starr, John M.; MacLullich, Alasdair M.J.; Wardlaw, Joanna M.; Deary, Ian J.; MacPherson, Sarah E.

    2015-01-01

    Functional neuroimaging studies report increased right prefrontal cortex (PFC) involvement during verbal memory tasks amongst low-scoring older individuals, compared to younger controls and their higher-scoring contemporaries. Some propose that this reflects inefficient use of neural resources through failure of the left PFC to inhibit non-task-related right PFC activity, via the anterior corpus callosum (CC). For others, it indicates partial compensation – that is, the right PFC cannot completely supplement the failing neural network, but contributes positively to performance. We propose that combining structural and diffusion brain MRI can be used to test predictions from these theories which have arisen from fMRI studies. We test these hypotheses in immediate and delayed verbal memory ability amongst 90 healthy older adults of mean age 73 years. Right hippocampus and left dorsolateral prefrontal cortex (DLPFC) volumes, and fractional anisotropy (FA) in the splenium made unique contributions to verbal memory ability in the whole group. There was no significant effect of anterior callosal white matter integrity on performance. Rather, segmented linear regression indicated that right DLPFC volume was a significantly stronger positive predictor of verbal memory for lower-scorers than higher-scorers, supporting a compensatory explanation for the differential involvement of the right frontal lobe in verbal memory tasks in older age. PMID:25241394

  14. Preferences of people with advanced heart failure-a structured narrative literature review to inform decision making in the palliative care setting.

    Science.gov (United States)

    Dev, Sandesh; Abernethy, Amy P; Rogers, Joseph G; O'Connor, Christopher M

    2012-09-01

    BACKGROUND AND APPROACH: There is a growing emphasis on the need for high-quality and patient-centered palliative care for patients with heart failure (HF) near end of life. Accordingly, clinicians require adequate knowledge of patient values and preferences, but this topic has been underreported in the HF literature. In response, we conducted a structured narrative review of available evidence regarding patient preferences for HF care near end of life, focusing on circumstances of death, advance care planning, and preferences for specific HF therapies. Patients had widely varying preferences for sudden ("unaware") death versus a death that was anticipated ("aware"), which would allow time to make arrangements and time with family; preferences influenced their choice of HF therapies. Patients and physicians rarely discussed advance care planning; physicians were rarely aware of resuscitation preferences. Advance care planning discussions rarely included preferences for limiting implantable cardioverter defibrillator use, and patients were often uninformed of the option of implantable cardioverter defibrillator deactivation. A substantial minority of patients strongly preferred improved quality of life versus extended survival, but preferences of individuals could not be easily predicted. Current evidence regarding preferences of patients with HF near end of life suggests substantial opportunities for improvement of end-of-life HF care. Most notably, the wide distribution of patient preferences highlights the need to tailor approach to patient wishes, avoiding assumptions of patient wishes. A research agenda and implications for health care provider training are proposed. Copyright © 2012 Mosby, Inc. All rights reserved.

  15. Cardiac remodeling in a new pig model of chronic heart failure: Assessment of left ventricular functional, metabolic, and structural changes using PET, CT, and echocardiography.

    Science.gov (United States)

    Tarkia, Miikka; Stark, Christoffer; Haavisto, Matti; Kentala, Rasmus; Vähäsilta, Tommi; Savunen, Timo; Strandberg, Marjatta; Hynninen, Ville-Veikko; Saunavaara, Virva; Tolvanen, Tuula; Teräs, Mika; Rokka, Johanna; Pietilä, Mikko; Saukko, Pekka; Roivainen, Anne; Saraste, Antti; Knuuti, Juhani

    2015-08-01

    Large animal models are needed to study disease mechanisms in heart failure (HF). In the present study we characterized the functional, metabolic, and structural changes of myocardium in a novel pig model of chronic myocardial infarction (MI) by using multimodality imaging and histology. Male farm pigs underwent a two-step occlusion of the left anterior descending coronary artery with concurrent distal ligation and implantation of a proximal ameroid constrictor (HF group), or sham operation (control group). Three months after the operation, cardiac output and wall stress were measured by echocardiography. Left ventricle (LV) volumes and mass were measured by computed tomography (CT). Myocardial perfusion was evaluated by [(15)O]water and oxygen consumption using [(11)C]acetate positron emission tomography, and the efficiency of myocardial work was calculated. Histological examinations were conducted to detect MI, hypertrophy, and fibrosis. Animals in the HF group had a large anterior MI scar. CT showed larger LV diastolic volume and lower ejection fraction in HF pigs than in controls. Perfusion and oxygen consumption in the remote non-infarcted myocardium were preserved in HF pigs as compared to controls. Global LV work and efficiency were significantly lower in HF than control pigs and was associated with increased wall stress. Histology showed myocyte hypertrophy but not increased interstitial fibrosis in the remote segments in HF pigs. The chronic post-infarction model of HF is suitable for studies aimed to evaluate LV remodeling and changes in oxidative metabolism and can be useful for testing new therapies for HF.

  16. The use of lifetime functions in the optimization of interventions on existing bridges considering maintenance and failure costs

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung-Ie [Department of Civil, Enviromental, and Architectural Enginnering, University of Colorado, Campus Box 428, Boulder, CO 80309-0428 (United States)]. E-mail: yangsione@dreamwiz.com; Frangopol, Dan M. [Department of Civil, Enviromental, and Architectural Enginnering, University of Colorado, Campus Box 428, Boulder, CO 80309-0428 (United States)]. E-mail: dan.frangopol@colorado.edu; Kawakami, Yoriko [Hanshin Expressway Public Corporation, Kobe Maintenance Department, 16-1 Shinko-cho Chuo-ku Kobe City, Hyogo, 650-0041 (Japan)]. E-mail: yoriko-kawakami@hepc.go.jp; Neves, Luis C. [Department of Civil, Enviromental, and Architectural Enginnering, University of Colorado, Campus Box 428, Boulder, CO 80309-0428 (United States)]. E-mail: lneves@civil.uminho.pt

    2006-06-15

    In the last decade, it became clear that life-cycle cost analysis of existing civil infrastructure must be used to optimally manage the growing number of aging and deteriorating structures. The uncertainties associated with deteriorating structures require the use of probabilistic methods to properly evaluate their lifetime performance. In this paper, the deterioration and the effect of maintenance actions are analyzed considering the performance of existing structures characterized by lifetime functions. These functions allow, in a simple manner, the consideration of the effect of aging on the decrease of the probability of survival of a structure, as well as the effect of maintenance actions. Models for the effects of proactive and reactive preventive maintenance, and essential maintenance actions are presented. Since the probability of failure is different from zero during the entire service life of a deteriorating structure and depends strongly on the maintenance strategy, the cost of failure is included in this analysis. The failure of one component in a structure does not usually lead to failure of the structure and, as a result, the safety of existing structures must be analyzed using a system reliability framework. The optimization consists of minimizing the sum of the cumulative maintenance and expected failure cost during the prescribed time horizon. Two examples of application of the proposed methodology are presented. In the first example, the sum of the maintenance and failure costs of a bridge in Colorado is minimized considering essential maintenance only and a fixed minimum acceptable probability of failure. In the second example, the expected lifetime cost, including maintenance and expected failure costs, of a multi-girder bridge is minimized considering reactive preventive maintenance actions.

  17. The use of lifetime functions in the optimization of interventions on existing bridges considering maintenance and failure costs

    International Nuclear Information System (INIS)

    Yang, Seung-Ie; Frangopol, Dan M.; Kawakami, Yoriko; Neves, Luis C.

    2006-01-01

    In the last decade, it became clear that life-cycle cost analysis of existing civil infrastructure must be used to optimally manage the growing number of aging and deteriorating structures. The uncertainties associated with deteriorating structures require the use of probabilistic methods to properly evaluate their lifetime performance. In this paper, the deterioration and the effect of maintenance actions are analyzed considering the performance of existing structures characterized by lifetime functions. These functions allow, in a simple manner, the consideration of the effect of aging on the decrease of the probability of survival of a structure, as well as the effect of maintenance actions. Models for the effects of proactive and reactive preventive maintenance, and essential maintenance actions are presented. Since the probability of failure is different from zero during the entire service life of a deteriorating structure and depends strongly on the maintenance strategy, the cost of failure is included in this analysis. The failure of one component in a structure does not usually lead to failure of the structure and, as a result, the safety of existing structures must be analyzed using a system reliability framework. The optimization consists of minimizing the sum of the cumulative maintenance and expected failure cost during the prescribed time horizon. Two examples of application of the proposed methodology are presented. In the first example, the sum of the maintenance and failure costs of a bridge in Colorado is minimized considering essential maintenance only and a fixed minimum acceptable probability of failure. In the second example, the expected lifetime cost, including maintenance and expected failure costs, of a multi-girder bridge is minimized considering reactive preventive maintenance actions

  18. Mechanical injuries of the eyeball: Frequency, structure, and possibility of the prevention

    Directory of Open Access Journals (Sweden)

    Jovanović Miloš

    2006-01-01

    Full Text Available Introduction. Some factors significant for development of mechanical injuries of the eyeball have been analyzed in the study. Objective. Basic objective of such analysis was prevention and reduction of these injuries. Method. Mechanical injuries of the eyeball in patients hospitalized at the Institute of Eye Disease, CCS in Belgrade, in five year period have been analyzed. Only patients with severe eye injuries were hospitalized. The following parameters were analyzed: sex, age, occupation of patients, residence, time of the inflicted injury, i.e. by months in a year, days in a week and hours in a day, place and way of inflicting the injury as well as visual acuity on admission. In addition, the type of injury was analyzed, i.e. contusion or penetrating with all resulting complications. Finally, the timing of primary surgical management of the eye injury was specified, if required. Results. A total number of hospitalized patients with mechanical eye injuries was 1642 during the last five years, meaning that one injury occurred daily. There were 1381 males and 261 females, meaning that males were 5.3 times more the victims of mechanical eye injuries. Out of all the injured, 861 (52.4% were from rural environment, while 781 (47.6% were urban population. The proportion of injuries of the right or the left eye was nearly equal, while both eyes were simultaneously injured in 21 (1.3% cases. The injuries were inflicted in all ages, but most frequently in working population ranging from 16 to 55 years, accounting for 60.8%. Unfortunately, a lot of the injured were children up to 15 years of age - 19.4%. The most commonly injured were workers - 39.8%, followed by students - 17.5%. A piece of wood was the cause of injury in 21.8%, sharp and pointed objects in 17.2%, hammer and metal in 14.2%, glass in 11.6%, and other different causes in varying percentage. There were also rare causes of injuries, such as those caused by zip, dog bite, rooster’s bill

  19. Respiratory failure in diabetic ketoacidosis

    Science.gov (United States)

    Konstantinov, Nikifor K; Rohrscheib, Mark; Agaba, Emmanuel I; Dorin, Richard I; Murata, Glen H; Tzamaloukas, Antonios H

    2015-01-01

    Respiratory failure complicating the course of diabetic ketoacidosis (DKA) is a source of increased morbidity and mortality. Detection of respiratory failure in DKA requires focused clinical monitoring, careful interpretation of arterial blood gases, and investigation for conditions that can affect adversely the respiration. Conditions that compromise respiratory function caused by DKA can be detected at presentation but are usually more prevalent during treatment. These conditions include deficits of potassium, magnesium and phosphate and hydrostatic or non-hydrostatic pulmonary edema. Conditions not caused by DKA that can worsen respiratory function under the added stress of DKA include infections of the respiratory system, pre-existing respiratory or neuromuscular disease and miscellaneous other conditions. Prompt recognition and management of the conditions that can lead to respiratory failure in DKA may prevent respiratory failure and improve mortality from DKA. PMID:26240698

  20. Structured triacylglycerol containing behenic and oleic acids suppresses triacylglycerol absorption and prevents obesity in rats

    Directory of Open Access Journals (Sweden)

    Takamatsu Kiyoharu

    2010-07-01

    Full Text Available Abstract Background Dietary 1(3-behenoyl-2,3(1-dioleoyl-rac-glycerol (BOO has been reported to inhibit pancreatic lipase activity in vitro and suppress postprandial hypertriacylglycerolemia in humans. In the present study, the anti-obesity activities of BOO and its inhibitory effects on lymphatic triacylglycerol (TAG absorption were investigated in rats. Methods In Experiment 1, rats were fed either BOO or soybean oil (SO diet for 6 weeks. In the BOO diet, 20% of SO was replaced with an experimental oil rich in BOO. In Experiments 2 and 3, rats cannulated in the thoracic duct were administered an emulsions containing trioleoylglycerol (OOO or an oil mixture (OOO:BOO, 9:1. Tri[1-14C]oleoylglycerol (14C-OOO was added to the emulsions administered in Experiment 3. Results No observable differences were detected in food intake or body weight gain between the BOO and SO groups in Experiment 1. Plasma and liver TAG concentrations and visceral fat weights were significantly lower in the BOO group than in the SO group. The apparent absorption rate of fat was significantly lower in the BOO group than in the SO group. In Experiment 2, the lymphatic recovery of oleic and behenic acids was significantly lower at 5 and 6 h after BOO administration than after OOO administration. In Experiment 3, the lymphatic recovery of 14C-OOO was significantly lower at 5 and 6 h after BOO administration than after OOO administration. Conclusions These results suggest that BOO prevents deposition of visceral fat and hepatic TAG by lowering and delaying intestinal absorption of TAG.

  1. Structural Dissection of a Gating Mechanism Preventing Misactivation of Ubiquitin by NEDD8’s E1

    Energy Technology Data Exchange (ETDEWEB)

    Souphron,J.; Waddell, M.; Paydar, A.; Tokgöz-Gromley, Z.; Roussel, M.; Schulman, B.

    2008-01-01

    Post-translational covalent modification by ubiquitin and ubiquitin-like proteins (UBLs) is a major eukaryotic mechanism for regulating protein function. In general, each UBL has its own E1 that serves as the entry point for a cascade. The E1 first binds the UBL and catalyzes adenylation of the UBL's C-terminus, prior to promoting UBL transfer to a downstream E2. Ubiquitin's Arg 72, which corresponds to Ala72 in the UBL NEDD8, is a key E1 selectivity determinant: swapping ubiquitin and NEDD8 residue 72 identity was shown previously to swap their E1 specificity. Correspondingly, Arg190 in the UBA3 subunit of NEDD8's heterodimeric E1 (the APPBP1-UBA3 complex), which corresponds to a Gln in ubiquitin's E1 UBA1, is a key UBL selectivity determinant. Here, we dissect this specificity with biochemical and X-ray crystallographic analysis of APPBP1-UBA3-NEDD8 complexes in which NEDD8's residue 72 and UBA3's residue 190 are substituted with different combinations of Ala, Arg, or Gln. APPBP1-UBA3's preference for NEDD8's Ala72 appears to be indirect, due to proper positioning of UBA3's Arg190. By contrast, our data are consistent with direct positive interactions between ubiquitin's Arg72 and an E1's Gln. However, APPBP1-UBA3's failure to interact with a UBL having Arg72 is not due to a lack of this favorable interaction, but rather arises from UBA3's Arg190 acting as a negative gate. Thus, parallel residues from different UBL pathways can utilize distinct mechanisms to dictate interaction selectivity, and specificity can be amplified by barriers that prevent binding to components of different conjugation cascades.

  2. Etiological Peculiarities in Pediatric Heart Failure

    OpenAIRE

    Angela, Butnariu; Gabriel, Samasca

    2015-01-01

    Heart failure in children presents important characteristic features different from adult congestive failure, from a pathophysiological and mostly from an etiopathogenic point of view. Heart failure in children is, in most cases, a consequence of congenital structural cardiac abnormalities that remained unoperated, underwent a palliative operation or presented post-surgery complications, or of cardiomyopathy. Based on the nature of the clinical presentation, new onset heart failure can be dif...

  3. [Prevention of alcoholism as a social, communicational and structural problem in industry].

    Science.gov (United States)

    König, R

    1991-08-01

    To promote effective aid to alcohol-dependents in a company it is essential to treat the problem "alcohol in the office, workshops and plant" not only as a problem concerning the alcohol-dependents and addicts, but as a problem that has to be jointly tackled by all the company divisions involved and by all the echelons of the firm. It has become evident that the multiplicator directly involved in helping alcohol-dependents must take into consideration the structure and group dynamics within the company before they can work efficiently. The following report deals with the difficulties within a company that are linked to this problem area. Examples serve to show how poorly efficient any aid to alcohol-dependents can be if the persons involved fail to see clearly which prerequisites and approaches are essential. Advice is given how to avoid such pitfalls and misunderstandings.

  4. Modified suture-bridge technique to prevent a marginal dog-ear deformity improves structural integrity after rotator cuff repair.

    Science.gov (United States)

    Ryu, Keun Jung; Kim, Bang Hyun; Lee, Yohan; Lee, Yoon Seok; Kim, Jae Hwa

    2015-03-01

    The arthroscopic suture-bridge technique has proved to provide biomechanically firm fixation of the torn rotator cuff to the tuberosity by increasing the footprint contact area and pressure. However, a marginal dog-ear deformity is encountered not infrequently when this technique is used, impeding full restoration of the torn cuff. To evaluate the structural and functional outcomes of the use of a modified suture-bridge technique to prevent a marginal dog-ear deformity compared with a conventional suture-bridge method in rotator cuff repair. Cohort study; Level of evidence 2. A consecutive series of 71 patients aged 50 to 65 years who underwent arthroscopic rotator cuff repair for full-thickness medium-sized to massive tears was evaluated. Patients were divided into 2 groups according to repair technique: a conventional suture-bridge technique (34 patients; group A) versus a modified suture-bridge technique to prevent a marginal dog-ear deformity (37 patients; group B). Radiographic evaluations included postoperative cuff integrity using MRI. Functional evaluations included pre- and postoperative range of motion (ROM), pain visual analog scale (VAS), the University of California, Los Angeles (UCLA) shoulder rating scale, the Constant score, and the American Shoulder and Elbow Surgeons (ASES) score. All patients were followed up clinically at a minimum of 1 year. When the 2 surgical techniques were compared, postoperative structural integrity by Sugaya classification showed the distribution of types I:II:III:IV:V to be 4:20:2:4:4 in group A and 20:12:4:0:1 in group B. More subjects in group B had a favorable Sugaya type compared with group A (P bridge technique repairs were found in the retear group (P = .03). There were significant differences between healed and retear groups in functional outcome scores, with worse results in the retear group. A modified suture-bridge technique to prevent a marginal dog-ear deformity provided better structural outcomes than a

  5. Failure Detector for Power-Factor Controller

    Science.gov (United States)

    Nola, F. J.

    1982-01-01

    New protective circuits have been developed for power-factor ac motor controllers. Circuits prevent direct current and consequent motor heating that would normally result from failure of solid-state switch in controller. Single-phase power-factor controller with short detector compensates for short-circuit failure in either direction by applying full power to motor. Controller with open detector compensates for open-circuit failure in either direction by turning off power to motor.

  6. Analysis of the thermal comfort and impact properties of the neoprene-spacer fabric structure for preventing the joint damages.

    Science.gov (United States)

    Ghorbani, Ehsan; Hasani, Hossein; Rafeian, Homa; Hashemibeni, Batool

    2013-07-01

    Frequent moves at the joint, plus external factors such as trauma, aging, and etc., are all reasons for joint damages. In order to protect and care of joints, the orthopedic textiles are used. To protect the joints, these textiles keep muscles warm to prevent shock. To produce orthopedic textiles, Neoprene foams have been traditionally used. These foams are flexible and resist impact, but are not comfortable enough and might cause problems for the consumer. This study introduces a new structure consisting of perforated Neoprene foam attached to the spacer fabric and also compares the properties of thermal and moisture comfort and impact properties of this structure in comparison with Neoprene foam. In order to measure the factors related to the samples lateral pressure behavior, a tensile tester was used. A uniform pressure is applied to the samples and a force - displacement curve is obtained. The test continues until the maximum compression force is reached to 50 N. The area under the curve is much greater; more energy is absorbed during the impact. In order to investigate the dynamic heat and moisture transfer of fabrics, an experimental apparatus was developed. This device made the simulation of sweating of human body possible and consisted of a controlled environmental chamber, sweating guarded hot plate, and data acquisition system. The findings show that the Neoprene-spacer fabric structure represents higher toughness values compared to other samples (P ≤ 0.001). Neoprene-spacer fabric structure (A3) has higher rate of moisture transport than conventional Neoprene foam; because of undesirable comfort characteristics in Neoprene. Results of the tests indicate full advantage of the new structure compared with the Neoprene foam for use in orthopedic textiles (P ≤ 0.001).

  7. Cable median barrier failure analysis and prevention.

    Science.gov (United States)

    2012-12-01

    Cross-median crashes have been identified as one of the highest injury or fatality risk crash types. Although crossmedian : crashes account for only 2% to 5% of all median crash events, they are disproportionately represented in the number : and freq...

  8. OBSTETRIC RENAL FAILURE

    Directory of Open Access Journals (Sweden)

    Rajeshwari

    2015-11-01

    common reasons were pregnancy induced hypertension, HELLP syndrome and obstetric haemorrhage and resulted in high risk condition for fetal and maternal mortality. The most effective measures still remain the careful prevention and the aggressive management of the obstetric complications. Ideal care for women with acute renal failure in pregnancy or post-partum requires a multidisciplinary approach that includes maternal-fetal medicine, critical care medicine, nephrology and neonatology specialties.

  9. Structure-Antifungal Activity Relationship of Fluorinated Dihydroguaiaretic Acid Derivatives and Preventive Activity against Alternaria alternata Japanese Pear Pathotype.

    Science.gov (United States)

    Nishiwaki, Hisashi; Nakazaki, Shoko; Akiyama, Koichi; Yamauchi, Satoshi

    2017-08-09

    The structure-activity relationship of the antifungal fluorinated dihydroguaiaretic acid derivatives was evaluated. Some of the newly synthesized lignan compounds were found to show higher antifungal activity against phytopathogenic fungi such as Alternaria alternata (Japanese pear and apple pathotypes) and A. citri than the lead compound, 3-fluoro-3'-methoxylignan-4'-ol (3). The broad antifungal spectrum of 3'-hydroxyphenyl derivative 16 was observed, and the 3'-fluoro-4'-hydroxyphenyl derivative 38 was found to show the highest activity against the A. alternata Japanese pear pathotype, with an EC 50 value of 11 μM. The preventive effect of the potent lignan on the infection of A. alternata in the Japanese pear's leaves was also shown.

  10. Can a combined screening/treatment programme prevent premature failure of renal transplants due to chronic rejection in patients with HLA antibodies: study protocol for the multicentre randomised controlled OuTSMART trial

    Science.gov (United States)

    2014-01-01

    Background Renal transplantation is the best treatment for kidney failure, in terms of length and quality of life and cost-effectiveness. However, most transplants fail after 10 to 12 years, consigning patients back onto dialysis. Damage by the immune system accounts for approximately 50% of failing transplants and it is possible to identify patients at risk by screening for the presence of antibodies against human leukocyte antigens. However, it is not clear how best to treat patients with antibodies. This trial will test a combined screening and treatment protocol in renal transplant recipients. Methods/Design Recipients >1 year post-transplantation, aged 18 to 70 with an estimated glomerular filtration rate >30 mL/min will be randomly allocated to blinded or unblinded screening arms, before being screened for the presence of antibodies. In the unblinded arm, test results will be revealed. Those with antibodies will have biomarker-led care, consisting of a change in their anti-rejection drugs to prednisone, tacrolimus and mycophenolate mofetil. In the blinded arm, screening results will be double blinded and all recruits will remain on current therapy (standard care). In both arms, those without antibodies will be retested every 8 months for 3 years. The primary outcome is the 3-year kidney failure rate for the antibody-positive recruits, as measured by initiation of long-term dialysis or re-transplantation, predicted to be approximately 20% in the standard care group but transplant dysfunction, incidence of infection, cancer and diabetes mellitus, an analysis of adherence with medication and a health economic analysis of the combined screening and treatment protocol. Blood samples will be collected and stored every 4 months and will form the basis of separately funded studies to identify new biomarkers associated with the outcomes. Discussion We have evidence that the biomarker-led care regime will be effective at preventing graft dysfunction and expect this to

  11. Wind Turbine Failures - Tackling current Problems in Failure Data Analysis

    Science.gov (United States)

    Reder, M. D.; Gonzalez, E.; Melero, J. J.

    2016-09-01

    The wind industry has been growing significantly over the past decades, resulting in a remarkable increase in installed wind power capacity. Turbine technologies are rapidly evolving in terms of complexity and size, and there is an urgent need for cost effective operation and maintenance (O&M) strategies. Especially unplanned downtime represents one of the main cost drivers of a modern wind farm. Here, reliability and failure prediction models can enable operators to apply preventive O&M strategies rather than corrective actions. In order to develop these models, the failure rates and downtimes of wind turbine (WT) components have to be understood profoundly. This paper is focused on tackling three of the main issues related to WT failure analyses. These are, the non-uniform data treatment, the scarcity of available failure analyses, and the lack of investigation on alternative data sources. For this, a modernised form of an existing WT taxonomy is introduced. Additionally, an extensive analysis of historical failure and downtime data of more than 4300 turbines is presented. Finally, the possibilities to encounter the lack of available failure data by complementing historical databases with Supervisory Control and Data Acquisition (SCADA) alarms are evaluated.

  12. Evaluation of Existing Structure and Civil Protection Management Framework in Greek Local Authorities: A Questionnaire Survey Demonstrates Why Prevention Fails

    Science.gov (United States)

    Papanikolaou, Dimitrios; Papanikolaou, Ioannis; Diakakis, Michalis; Deligiannakis, Georgios

    2013-04-01

    In the face of a growing number of natural disasters and the increasing costs associated with them, Europe and Greece in particular, have devoted significant efforts and resources in natural hazards mitigation during the last decades. Despite the significant legislative efforts (e.g. 1998/22/EC, 2001/792/EC, 2007/60/EC Directives, 3013/2002 Act) and even though a number of steps has been taken towards improving civil protection, recent catastrophic events have illustrated the weaknesses of current approaches. In particular, in Greece, events such as the 1999 Athens earthquake, the 2007 and 2009 wildfires have shown the inadequacy of prevention and mitigation practices. Given the enhanced civil protection responsibilities, given by the Greek national law (Acts 3013/2002, 3852/2010) to local authorities in Greece, this work analyses and evaluates the existing structure and current management framework under which local authorities function and examines their risk mitigation practices. We conducted the largest questionnaire survey regarding Civil Protections issues, among the municipalities of Greece. To this aim, this work used a innovative online tool to assess current framework. Therefore, a network connecting civil protection departments of municipalities was developed, based on an Internet platform that acted also as a communication tool. Overall, we had feedback either online or offline from 125 municipalities across the country (representing more than one/third of the total municipalities of Greece). Through this network, municipal civil protection officials completed surveys designed to obtain and quantify information on several aspects of civil protection practices and infrastructure. In particular, the examined factors included: (i) personnel and equipment, (ii) inter-agency cooperation, (iii) training, (iv) compliance with existing regulations and (v) persistent problems encountered by civil protection departments, that prevent the effectiveness of current

  13. Development in fracture mechanics and failure assessment

    International Nuclear Information System (INIS)

    Chell, G.G.

    1978-01-01

    Application of the theories of fracture mechanics can help avoid the type of catastrophic failure that has occurred in structures, eg the failure, whilst undergoing a routine test, of a turbogenerator for Hinkly Point power station. The development is described for a procedure for summarising the salient features of fracture theory as applied to steel structures. This is achieved by the introduction of a relatively simple failure assessment diagram which may be used by unspecialised staff. (author)

  14. Management of functional Sprint Fidelis leads at cardiac resynchronization therapy-defibrillator generator replacement: a novel option for preventing inappropriate shocks from lead failure in fragile patients with high risk of sudden death.

    Science.gov (United States)

    Zhu, Dennis W X; Chu, Matthew M; House, Chad M

    2017-12-01

    In patients with a functional Sprint Fidelis lead at generator replacement, the manufacturer recommended to either continue to use the existing lead or replace it with a new lead. For those patients who continue to use a functional Fidelis lead, the risk of inappropriate shocks remains present if the lead fails in the future. We evaluated the feasibility of an alternative approach at the time of cardiac resynchronization therapy-defibrillator (CRT-D) generator replacement in patients with a functional bipolar left ventricular (LV) lead for prevention of inappropriate shocks from future Fidelis lead failure. During the procedure, the pace/sense IS-1 connection pin of the functional Fidelis lead was intentionally inserted into the LV port of the new CRT-D generator, while the existing bipolar LV lead IS-1 connection pin was inserted into the right ventricular (RV) pace/sense port. After such switching, the existing bipolar LV lead was used for functional LV pacing/sensing, while the Fidelis lead was used for functional RV pacing and high voltage shock only and could no longer be used for the purpose of sensing and detecting. This approach precluded oversensing and inappropriate shocks should the functional Fidelis lead fail in the future. Six fragile patients, who were not considered suitable candidates for lead replacement, underwent the alternative approach. During a follow-up of 35 ± 23 months, the CRT-D system functioned normally in five patients. The Fidelis lead fractured in one patient 7 months after generator replacement. The malfunction was detected promptly and the defected lead was replaced. No inappropriate detections or shock was triggered. In CRT-D patients with a functional Fidelis lead and a bipolar LV lead, switching of the Fidelis lead pace/sense IS-1 pin with the bipolar LV lead IS-1 pin at generator replacement did not affect normal system function. This novel approach may be valuable in fragile patients with high risk of sudden death for

  15. B-type natriuretic peptide measurement in primary care; magnitude of associations with cardiovascular risk factors and their therapies. Observations from the STOP-HF (St. Vincent's Screening TO Prevent Heart Failure) study.

    LENUS (Irish Health Repository)

    Conlon, Carmel M

    2012-02-01

    BACKGROUND: An effective prevention strategy for heart failure in primary care requires a reliable screening tool for asymptomatic ventricular dysfunction. Preliminary data indicate that B-type natriuretic peptide (BNP) may be suitable for this task. However, for the most effective use of this peptide, the interrelationships between associated risk factors and their therapies on BNP, and in particular their magnitude of effect, needs to be established in a large primary care population. Therefore, the objective of the study was to establish the extent of the association between BNP, cardiovascular risk factors and their therapies. METHODS: BNP measurement and clinical review was preformed on 1122 primary care patients with cardiovascular risk factors. Multivariate analyses identified significant associates of BNP concentrations which were further explored to establish the magnitude of their association. RESULTS: Associates of BNP were age (1.36-fold increase in BNP\\/decade), female (1.28), beta-blockers (1.90), myocardial infarction (1.36), arrhythmia (1.98), diastolic blood pressure; all p<0.01. A novel method was devised that plotted median BNP per sliding decade of age for the various combinations of these principal associates. CONCLUSIONS: The data presented underline the importance of considering several clinical and therapeutic factors when interpreting BNP concentrations. Most of these variables were associated with increased concentrations, which may in part explain the observed false-positive rates for detecting ventricular dysfunction using this peptide. Furthermore, the design of studies or protocols using BNP as an endpoint or a clinical tool should take particular account of these associations. This analysis provides the foundation for age, risk factor and therapy adjusted reference ranges for BNP in this setting.

  16. Reassessing guidelines for heart failure

    Directory of Open Access Journals (Sweden)

    Helmut Drexler

    2004-03-01

    Full Text Available Significant progress has been made in the last few years in the management of heart failure. In particular several trials have given significant results. It has become apparent that heart failure may be prevented in some patients by treatment of risk factors such as coronary artery disease. Experience with angiotensin-converting enzyme (ACE inhibitors has shown that the survival and symptomatic benefits do last in the long term, and confirm that they are the first-line treatment in heart failure. The results of a number of trials using the angiotensin receptor blockers (ARBs candesartan, valsartan and losartan are presented and discussed. There is also some experience now in the use of candesartan for patients with heart failure and preserved left ventricular systolic function. The COMET trial compared the β-blockers carvedilol and metoprolol tartrate, and suggests that there may be differences in clinical effect between β-blockers. The selective aldosterone receptor blocker eplerenone was evaluated in the EPHESUS trial in post-MI patients with signs of heart failure. Based on these clinical trials, heart failure guidelines are now being updated.

  17. Failure Effects Evaluation for ATC Automation System

    Directory of Open Access Journals (Sweden)

    Rui Li

    2017-01-01

    Full Text Available ATC (air traffic control automation system is a complex system, which helps maintain the air traffic order, guarantee the flight interval, and prevent aircraft collision. It is essential to ensure the safety of air traffic. Failure effects evaluation is an important part of ATC automation system reliability engineering. The failure effects evaluation of ATC automation system is aimed at the effects of modules or components which affect the performance and functionality of the system. By analyzing and evaluating the failure modes and their causes and effects, some reasonable improvement measures and preventive maintenance plans can be established. In this paper, the failure effects evaluation framework considering performance and functionality of the system is established on the basis of reliability theory. Some algorithms for the quantitative evaluation of failure effects on performance of ATC automation system are proposed. According to the algorithms, the quantitative evaluation of reliability, availability, maintainability, and other assessment indicators can be calculated.

  18. Railway-controller-perceived mental work load, cognitive failure and risky commuting.

    Science.gov (United States)

    Elfering, Achim; Grebner, Simone; Haller, Martina

    2012-01-01

    This questionnaire study tests cognitive failures as a mediator of the potential influence of mental work demands and conscientiousness on risky commuting. Participants were 104 railway-controllers (19% female). Failure of memory, attention regulation and action execution were assessed with the Workplace Cognitive Failure (WCF) scale. Mental work demands were measured by the Instrument for Stress-Oriented Task Analysis (ISTA). A structural equation model testing WCF as the mediator of (1) the relationship between mental work demands and risky commuting (p work and also during commuting, thereby reducing commuting safety. The results underline the need for work redesign to improve commuting safety. Commuting accidents occur frequently and at high cost. This study shows that mental work demands of railway staff are related to cognitive failure and risky commuting behaviour such as failing to give way and overlooking stop signs. Primary prevention of commuting accidents should include reduction of mental workload.

  19. Monitoring Corrosion of Steel Bars in Reinforced Concrete Structures

    Science.gov (United States)

    Verma, Sanjeev Kumar; Bhadauria, Sudhir Singh; Akhtar, Saleem

    2014-01-01

    Corrosion of steel bars embedded in reinforced concrete (RC) structures reduces the service life and durability of structures causing early failure of structure, which costs significantly for inspection and maintenance of deteriorating structures. Hence, monitoring of reinforcement corrosion is of significant importance for preventing premature failure of structures. This paper attempts to present the importance of monitoring reinforcement corrosion and describes the different methods for evaluating the corrosion state of RC structures, especially hal-cell potential (HCP) method. This paper also presents few techniques to protect concrete from corrosion. PMID:24558346

  20. Monitoring corrosion of steel bars in reinforced concrete structures.

    Science.gov (United States)

    Verma, Sanjeev Kumar; Bhadauria, Sudhir Singh; Akhtar, Saleem

    2014-01-01

    Corrosion of steel bars embedded in reinforced concrete (RC) structures reduces the service life and durability of structures causing early failure of structure, which costs significantly for inspection and maintenance of deteriorating structures. Hence, monitoring of reinforcement corrosion is of significant importance for preventing premature failure of structures. This paper attempts to present the importance of monitoring reinforcement corrosion and describes the different methods for evaluating the corrosion state of RC structures, especially hal-cell potential (HCP) method. This paper also presents few techniques to protect concrete from corrosion.

  1. Monitoring Corrosion of Steel Bars in Reinforced Concrete Structures

    Directory of Open Access Journals (Sweden)

    Sanjeev Kumar Verma

    2014-01-01

    Full Text Available Corrosion of steel bars embedded in reinforced concrete (RC structures reduces the service life and durability of structures causing early failure of structure, which costs significantly for inspection and maintenance of deteriorating structures. Hence, monitoring of reinforcement corrosion is of significant importance for preventing premature failure of structures. This paper attempts to present the importance of monitoring reinforcement corrosion and describes the different methods for evaluating the corrosion state of RC structures, especially hal-cell potential (HCP method. This paper also presents few techniques to protect concrete from corrosion.

  2. Failure Modes of thin supported Membranes

    DEFF Research Database (Denmark)

    Hendriksen, Peter Vang; Høgsberg, J.R.; Kjeldsen, Ane Mette

    2007-01-01

    Four different failure modes relevant to tubular supported membranes (thin dense films on a thick porous support) were analyzed. The failure modes were: 1) Structural collapse due to external pressure 2) burst of locally unsupported areas, 3) formation of surface cracks in the membrane due to TEC......-mismatches, and finally 4) delamination between membrane and support due to expansion of the membrane on use. Design criteria to minimize risk of failure by the four different modes are discussed. The theoretical analysis of the two last failure modes is compared to failures observed on actual components....

  3. 75 FR 40845 - Preventing Deaths and Injuries of Fire Fighters Using Risk Management Principles at Structure Fires

    Science.gov (United States)

    2010-07-14

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention [Docket Number NIOSH 141-A] Preventing Deaths and Injuries of Fire Fighters Using Risk Management Principles at... Disease Control and Prevention (CDC), Department of Health and Human Services (HHS). ACTION: Notice of...

  4. Effectiveness and predictors of failure of noninvasive mechanical ventilation in acute respiratory failure.

    Science.gov (United States)

    Martín-González, F; González-Robledo, J; Sánchez-Hernández, F; Moreno-García, M N; Barreda-Mellado, I

    2016-01-01

    To assess the effectiveness and identify predictors of failure of noninvasive ventilation. A retrospective, longitudinal descriptive study was made. Adult patients with acute respiratory failure. A total of 410 consecutive patients with noninvasive ventilation treated in an Intensive Care Unit of a tertiary university hospital from 2006 to 2011. Noninvasive ventilation. Demographic variables and clinical and laboratory test parameters at the start and two hours after the start of noninvasive ventilation. Evolution during admission to the Unit and until hospital discharge. The failure rate was 50%, with an overall mortality rate of 33%. A total of 156 patients had hypoxemic respiratory failure, 87 postextubation respiratory failure, 78 exacerbation of chronic obstructive pulmonary disease, 61 hypercapnic respiratory failure without chronic obstructive pulmonary disease, and 28 had acute pulmonary edema. The failure rates were 74%, 54%, 27%, 31% and 21%, respectively. The etiology of respiratory failure, serum bilirubin at the start, APACHEII score, radiological findings, the need for sedation to tolerate noninvasive ventilation, changes in level of consciousness, PaO2/FIO2 ratio, respiratory rate and heart rate from the start and two hours after the start of noninvasive ventilation were independently associated to failure. The effectiveness of noninvasive ventilation varies according to the etiology of respiratory failure. Its use in hypoxemic respiratory failure and postextubation respiratory failure should be assessed individually. Predictors of failure could be useful to prevent delayed intubation. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

  5. Heart failure - medicines

    Science.gov (United States)

    CHF - medicines; Congestive heart failure - medicines; Cardiomyopathy - medicines; HF - medicines ... will need to take most of your heart failure medicines every day. Some medicines are taken once ...

  6. Intestinal failure: a review

    Science.gov (United States)

    Allan, Philip; Lal, Simon

    2018-01-01

    Intestinal failure (IF) is the inability of the gut to absorb necessary water, macronutrients (carbohydrate, protein, and fat), micronutrients, and electrolytes sufficient to sustain life and requiring intravenous supplementation or replacement. Acute IF (types 1 and 2) is the initial phase of the illness and may last for weeks to a few months, and chronic IF (type 3) from months to years. The challenge of caring for patients with IF is not merely the management of the underlying condition leading to IF or the correct provision of appropriate nutrition or both but also the prevention of complications, whether thromboembolic phenomenon (for example, venous occlusion), central venous catheter-related bloodstream infection, IF-associated liver disease, or metabolic bone disease. This review looks at recent questions regarding chronic IF (type 3), its diagnosis and management, the role of the multidisciplinary team, and novel therapies, including hormonal treatment for short bowel syndrome but also surgical options for intestinal lengthening and intestinal transplant. PMID:29399329

  7. Importance analysis for the systems with common cause failures

    International Nuclear Information System (INIS)

    Pan Zhijie; Nonaka, Yasuo

    1995-01-01

    This paper extends the importance analysis technique to the research field of common cause failures to evaluate the structure importance, probability importance, and β-importance for the systems with common cause failures. These importance measures would help reliability analysts to limit the common cause failure analysis framework and find efficient defence strategies against common cause failures

  8. Risk factors for acute renal failure: inherent and modifiable risks.

    Science.gov (United States)

    Leblanc, Martine; Kellum, John A; Gibney, R T Noel; Lieberthal, Wilfred; Tumlin, James; Mehta, Ravindra

    2005-12-01

    Our purpose is to discuss established risk factors in the development of acute renal failure and briefly overview clinical markers and preventive measures. Findings from the literature support the role of older age, diabetes, underlying renal insufficiency, and heart failure as predisposing factors for acute renal failure. Diabetics with baseline renal insufficiency represent the highest risk subgroup. An association between sepsis, hypovolemia, and acute renal failure is clear. Liver failure, rhabdomyolysis, and open-heart surgery (especially valve replacement) are clinical conditions potentially leading to acute renal failure. Increasing evidence shows that intraabdominal hypertension may contribute to the development of acute renal failure. Radiocontrast and antimicrobial agents are the most common causes of nephrotoxic acute renal failure. In terms of prevention, avoiding nephrotoxins when possible is certainly desirable; fluid therapy is an effective prevention measure in certain clinical circumstances. Supporting cardiac output, mean arterial pressure, and renal perfusion pressure are indicated to reduce the risk for acute renal failure. Nonionic, isoosmolar intravenous contrast should be used in high-risk patients. Although urine output and serum creatinine lack sensitivity and specificity in acute renal failure, they remain the most used parameters in clinical practice. There are identified risk factors of acute renal failure. Because acute renal failure is associated with a worsening outcome, particularly if occurring in critical illness and if severe enough to require renal replacement therapy, preventive measures should be part of appropriate management.

  9. Psychosocial risk factors and heart failure hospitalization

    DEFF Research Database (Denmark)

    Rod, Naja Hulvej; Andersen, Ingelise; Prescott, Eva

    2011-01-01

    Prospective studies on the role of psychosocial factors in heart failure development are virtually nonexistent. The authors aimed to address the effect of psychosocial factors on the risk of heart failure hospitalization in men and women free of cardiovascular disease. In 1991-1993, the 8......-fourth of the population reported some degree of vital exhaustion. The vital exhaustion score was associated with a higher risk of heart failure in a dose-response manner (P risk of heart failure in both men (hazard ratio = 1.93, 95% confidence...... in the population, even a modestly higher risk of heart failure associated with vital exhaustion may be of importance in the planning of future preventive strategies for heart failure....

  10. Heart failure - surgeries and devices

    Science.gov (United States)

    CHF - surgery; Congestive heart failure - surgery; Cardiomyopathy - surgery; HF - surgery; Intra-aortic balloon pumps - heart failure; IABP - heart failure; Catheter based assist devices - heart failure

  11. Scenario-based assessment of stored water structure function for flood prevention and irrigation in Nile River

    Science.gov (United States)

    Luo, P.; Takara, K. T.; Watanabe, T.; He, B.; Apip, A.; Duan, W.; Nakagami, K.

    2013-12-01

    Inundation simulation is very import for flood risk management to reduce the damage and economic loss and provide escape information of flood disaster. Paleo-inundation study which is a part of paleo-flood hydrology study is to calculate the inundation conditions under the historical events by using the historical information and modern methods. Paleo-inundation analysis play an important role on reconstructing the flooding and damage conditions, evaluating the historical flood control policy, providing the experiences of historical flood risk management and escape technology. The stored water structure which also called basin scale method is to build some square paddy field to store the water which may over flow from Nile River. The basin scale method has been used for the flood prevention and irrigation in Nile River from 1800s. In this study, the main objectives are to producing the basic process for the paleo-inundation reconstruction and paleo-hydrology analysis in the river basin area which is lack of observed data, to provide a case study for the paleo-inundation reconstruction assessment, and give a discussion on the basic process of paleo-hydrology and paleo-inundation assessment.

  12. Is cost a structural barrier preventing men who have sex with men accessing condoms? A systematic review.

    Science.gov (United States)

    Ubrihien, Ashley; Davies, Stephen C; Driscoll, Tim

    2016-11-01

    A systematic review was undertaken to determine whether cost is a structural barrier preventing men who have sex with men (MSM) accessing condoms. Studies were examined from a range of countries where condoms have been distributed free to particular populations and also those where condoms were available at a cost to the individual. The study inclusion criteria were: published between January 1990 and September 2014 inclusive; published in any language, discussed cost as a barrier to condom use, discussed cost barriers to MSM accessing condoms and included a measure of outcome. Articles were systematically extracted from MEDLINE, Embase, PyschINFO and Informat using the five search terms; Male Homosexuality, Access, Cost, Cost and Cost analysis, Condoms. Sixty-four articles were initially identified and 11 included in the final review. The included studies used cost-utility analysis, qualitative, cross-sectional, cohort or randomised control trial design. Large-scale free distribution programmes and smaller targeted programmes showed positive correlations in reducing the burden of disease from HIV and other sexually transmitted infections through eliminating the issue of cost. Decreasing the cost of condoms, and providing them for no cost, appears to increase their utilisation amongst MSM and possibly reduce the burden from HIV and other sexually transmitted infections. Inequality and stigma remain important barriers to MSM accessing and using condoms particularly in the developing world.

  13. Cardiac structure and function, remodeling, and clinical outcomes among patients with diabetes after myocardial infarction complicated by left ventricular systolic dysfunction, heart failure, or both

    DEFF Research Database (Denmark)

    Shah, Amil M; Hung, Chung-Lieh; Shin, Sung Hee

    2011-01-01

    The mechanisms responsible for the increased risk of heart failure (HF) post-myocardial infarction (MI) may differ between patients with versus without diabetes. We hypothesized that after high-risk MI, patients with diabetes would demonstrate patterns of remodeling that are suggestive of reduced...

  14. Electrical failure analysis for root-cause determination

    International Nuclear Information System (INIS)

    Riddle, J.

    1990-01-01

    This paper outlines a practical failure analysis sequence. Several technical definitions are required. A failure is defined as a component that was operating in a system where the system malfunctioned and the replacement of the device restored system functionality. The failure mode is the malfunctioning behavior of the device. The failure mechanism is the underlying cause or source of the failure mode. The failure mechanism is the root cause of the failure mode. The failure analysis procedure needs to be adequately refined to result in the determination of the cause of failure to the degree that corrective action or design changes will prevent recurrence of the failure mode or mechanism. An example of a root-cause determination analysis performed for a nuclear power industry customer serves to illustrate the analysis methodology

  15. Advanced Heart Failure

    Science.gov (United States)

    ... Artery Disease Venous Thromboembolism Aortic Aneurysm More Advanced Heart Failure Updated:May 9,2017 When heart failure (HF) ... Making This content was last reviewed May 2017. Heart Failure • Home • About Heart Failure • Causes and Risks for ...

  16. Modeling Failure of 3D Fiber Reinforced Foam Core Sandwich Structures with Defects Using a Multi-Scale Finite Element Method

    Data.gov (United States)

    National Aeronautics and Space Administration — Many structures designed today including spacecraft and launch vehicles utilize sandwich composites as primary structures. Current interest surrounds the engineering...

  17. Academic Failure and Child-to-Parent Violence: Family Protective Factors.

    Science.gov (United States)

    Ibabe, Izaskun

    2016-01-01

    A reduction in academic achievement over the course of adolescence has been observed. School failure is characterized by difficulties to teaching school goals. A variety of other behavioral problems are often associated with school failure. Child-to-parent violence has been associated with different school problems. The main objective of current study was to examine the contribution of family variables (parental education level, family cohesion, and positive family discipline) on academic failure and child-to-parent violence of adolescents from a community sample. Moreover, a goal was to explore if academic failure was a valid predictor of child-to-parent violence. To this end, it has been developed a comprehensive statistical model through Structural Equation Modeling (SEM). Participants were 584 children from eight secondary schools in the Basque Country (Spain) and aged between 12 and 18. Among other scales Conflict Tactics Scale and Family Environment Scale were administrated for measuring child-to-parent violence and family cohesion environment, respectively. The structural model revealed that parental education level is a relevant protective factor against academic failure. Positive family discipline (inductive discipline, supervision, and penalty) show a significant association with child-to-parent violence and academic failure. Disciplinary practices could be more efficient to prevent child-to-parent violence or school failure if children perceive a positive environment in their home. However, these findings could be explained by inverse causality, because some parents respond to child-to-parent violence or academic failure with disciplinary strategies. School failure had indirect effects on child-to-parent violence through family cohesion. For all that, education policies should focus on parental education courses for disadvantaged families in order to generate appropriate learning environments at home and to foster improvement of parent

  18. Immune mediated liver failure

    OpenAIRE

    Wang, Xiaojing; Ning, Qin

    2014-01-01

    Liver failure is a clinical syndrome of various etiologies, manifesting as jaundice, encephalopathy, coagulopathy and circulatory dysfunction, which result in subsequent multiorgan failure. Clinically, liver failure is classified into four categories: acute, subacute, acute-on-chronic and chronic liver failure. Massive hepatocyte death is considered to be the core event in the development of liver failure, which occurs when the extent of hepatocyte death is beyond the liver regenerative capac...

  19. Effectiveness of Structured Teaching Programme on Knowledge regarding Risk factors and Prevention of Suicidal Behaviour among Adolescents in a selected College, Salem, Tamil Nadu

    Directory of Open Access Journals (Sweden)

    N Loganathan

    2015-12-01

    Full Text Available Background & Objectives: The aim of this study is to assess the knowledge regarding risk factors and prevention of suicidal behavior, to evaluate the effectiveness of structured teaching programme on knowledge regarding risk factors and prevention of suicidal behaviour among Adolescents, and to associate the pre-test knowledge regarding risk factors and prevention of suicidal behaviour among adolescents with their selected demographic variables.Materials & Methods: A quantitative evaluative approach with a pre-experimental (one group pre test- post test design was adopted; the setting of the study was Sri Vidya Mandir College, Salem, Tamilnadu. A Structured Self-administered questionnaire was used to assess the knowledge of the adolescents. The systematic random sampling technique was used and 60 adolescents involved on Structured Teaching Programme regarding Risk factors and prevention of Suicidal Behaviour by using a Power-point slide presentation followed with pre-test. On 7th day, the post test was conducted. The data collection period of the study was 09.12.2014 to 15.12.2014.Results: The study findings revealed that during Pre-test, the knowledge regarding risk factors and prevention of suicidal behaviour among adolescents, 45(75% had inadequate knowledge, 15(25% had moderately adequate knowledge and none of them had adequate knowledge. During post test, 23 adolescents (38.33% had adequate knowledge, 37(61.67% had moderately adequate knowledge and none of them had inadequate knowledge. The mean score during pre-test was 9.9±3.88 and the mean score during post test was 17.03±4.12. The paired ‘t’ value was 16.84 which were significant at p<0.05 level. Thus it shows that the structured teaching programme was effective in improving knowledge regarding risk factors and prevention of suicidal behaviour among adolescents. There was no significant association found between the pre-test scores on knowledge regarding risk factors and

  20. Prevention of uncontrolled progressive collapse of a high-rise brick building

    Directory of Open Access Journals (Sweden)

    Pakhmurin Oleg

    2018-01-01

    Full Text Available In recent years, there is a trend towards increasing the failure rate of buildings and structures as a result of unforeseen situations. This study is aimed at assessing the operational reliability of the structure to prevent emergencies and progressive collapse. The behavior of structures affected by various factors was analyzed. The operational condition of a building with stone walls and a rigid structural frame constructed in the middle of the 20th century was considered. By means of a detailed instrumental examination, effects of long-term operation, climatic factors and violations during construction on the serviceability of the building were analyzed. Geotechnical conditions of the site were investigated. Necessary re-calculations for load-bearing structural elements and foundations were carried out. An expected failure diagram for vertical load-bearing structures of the building is presented. Proposals for preventing progressive collapse were developed on the basis of the author's technique.

  1. What community-level strategies are needed to secure women's property rights in Western Kenya? Laying the groundwork for a future structural HIV prevention intervention.

    Science.gov (United States)

    Dworkin, Shari L; Lu, Tiffany; Grabe, Shelly; Kwena, Zachary; Mwaura-Muiru, Esther; Bukusi, Elizabeth

    2014-01-01

    Despite the recognized need for structural-level HIV prevention interventions that focus on economic empowerment to reduce women's HIV risks, few science-based programs have focused on securing women's land ownership as a primary or secondary HIV risk reduction strategy. The current study focused on a community-led land and property rights model that was implemented in two rural areas of western Kenya where HIV prevalence was high (24-30%) and property rights violations were common. The program was designed to reduce women's HIV risk at the community level by protecting and enhancing women's access to and ownership of land. Through in-depth interviews with 50 program leaders and implementers of this program we sought to identify the strategies that were used to prevent, mediate, and resolve property rights violations. Results included four strategies: (1) rights-based education of both women and men individually and at the community level, (2) funeral committees that intervene to prevent property grabbing and disinheritance, (3) paralegal training of traditional leaders and community members and local adjudication of cases of property rights violations, and (4) referring property rights violations to the formal justice system when these are not resolved at the community level. Study participants underscored that local mediation of cases resulted in a higher success rate than women experienced in the formal court system, underscoring the importance of community-level solutions to property rights violations. The current study assists researchers in understanding the steps needed to prevent and resolve women's property rights violations so as to bolster the literature on potential structural HIV prevention interventions. Future research should rigorously test property rights programs as a structural HIV prevention intervention.

  2. Characterizing the Structure and Functions of Social Networks of Men Who Have Sex with Men in Ghana, West Africa: Implications for Peer-Based HIV Prevention.

    Science.gov (United States)

    Maina, Geoffrey; Strudwick, Gillian; Lalani, Yasmin; Boakye, Francis; Wilton, Leo; Nelson, LaRon E

    Men who have sex with men (MSM) in Ghana are at an increased risk of contracting HIV. Understanding the social networks of MSM may support the development of HIV prevention strategies for this unique population. This article explores the structure and function of the social networks of MSM from 22 focus groups drawn from two urban and one rural setting in Ghana. Gaining insights into the characteristics of these networks will allow health care providers to design HIV prevention efforts and increase access to these programs. Copyright © 2017 Association of Nurses in AIDS Care. All rights reserved.

  3. Low-rise shear wall failure modes

    International Nuclear Information System (INIS)

    Farrar, C.R.; Hashimoto, P.S.; Reed, J.W.

    1991-01-01

    A summary of the data that are available concerning the structural response of low-rise shear walls is presented. This data will be used to address two failure modes associated with the shear wall structures. First, data concerning the seismic capacity of the shear walls with emphasis on excessive deformations that can cause equipment failure are examined. Second, data concerning the dynamic properties of shear walls (stiffness and damping) that are necessary to compute the seismic inputs to attached equipment are summarized. This case addresses the failure of equipment when the structure remains functional. 23 refs

  4. Angiotensin inhibition in heart failure

    Directory of Open Access Journals (Sweden)

    John JV Mcmurray

    2004-03-01

    Full Text Available Survival in patients with heart failure remains very poor, and is worse than that for most common cancers, including bowel cancer in men and breast cancer in women. The renin-angiotensin-aldosterone system (RAAS is not completely blocked by angiotensin-converting enzyme (ACE inhibition. Blockade of the RAAS at the AT1-receptor has the theoretical benefit of more effective blockade of the actions of angiotensin II. ACE inhibitors (ACE-Is prevent the breakdown of bradykinin: this has been blamed for some of the unwanted effects of ACE-Is although bradykinin may have advantageous effects in heart failure. Consequently, ACE-Is and ARBs might be complementary or even additive treatments; recent trials have tested these hypotheses. The Candesartan in Heart failure Assessment of Reduction in Mortality and morbidity (CHARM programme compared the angiotensin receptor blocker (ARB candesartan (target dose 32 mg once daily to placebo in three distinct but complementary populations of patients with symptomatic heart failure. These were: patients with reduced left ventricular ejection fraction (LVEF who were ACE-I-intolerant (CHARM-Alternative; patients with reduced LVEF who were being treated with ACE-Is (CHARM-Added; and patients with preserved left ventricular systolic function (CHARM-Preserved. There were substantial and statistically significant reductions in the primary composite end point (risk of cardiovascular death or hospital admission for heart failure in CHARM-Alternative. This was also the case in CHARM-Added, supporting and extending the findings of Val-HeFT. In CHARM-Preserved, the effect of candesartan on the primary end point did not reach conventional statistical significance though hospital admission for heart failure was reduced significantly with candesartan. In the CHARM-Overall programme there was a statistically borderline reduction in all-cause mortality with a clear reduction in cardiovascular mortality. All-cause mortality was

  5. Angiotensin inhibition in heart failure

    Directory of Open Access Journals (Sweden)

    John JV McMurray

    2004-03-01

    Full Text Available Survival in patients with heart failure remains very poor, and is worse than that for most common cancers, including bowel cancer in men and breast cancer in women. The renin-angiotensin-aldosterone system (RAAS is not completely blocked by angiotensin-converting enzyme (ACE inhibition. Blockade of the RAAS at the AT1-receptor has the theoretical benefit of more effective blockade of the actions of angiotensin II. ACE inhibitors (ACE-Is prevent the breakdown of bradykinin: this has been blamed for some of the unwanted effects of ACE-Is although bradykinin may have advantageous effects in heart failure. Consequently, ACE-Is and ARBs might be complementary or even additive treatments; recent trials have tested these hypotheses.The Candesartan in Heart failure Assessment of Reduction in Mortality and morbidity (CHARM programme compared the angiotensin receptor blocker (ARB candesartan (target dose 32 mg once daily to placebo in three distinct but complementary populations of patients with symptomatic heart failure. These were: patients with reduced left ventricular ejection fraction (LVEF who were ACE-I-intolerant (CHARM-Alternative; patients with reduced LVEF who were being treated with ACE-Is (CHARM-Added; and patients with preserved left ventricular systolic function (CHARM-Preserved.There were substantial and statistically significant reductions in the primary composite end point (risk of cardiovascular death or hospital admission for heart failure in CHARM-Alternative. This was also the case in CHARM-Added, supporting and extending the findings of Val-HeFT. In CHARM-Preserved, the effect of candesartan on the primary end point did not reach conventional statistical significance though hospital admission for heart failure was reduced significantly with candesartan. In the CHARM-Overall programme there was a statistically borderline reduction in all-cause mortality with a clear reduction in cardiovascular mortality. All-cause mortality was

  6. Probabilistic inspection strategies for minimizing service failures

    Science.gov (United States)

    Brot, Abraham

    1994-09-01

    The INSIM computer program is described which simulates the 'limited fatigue life' environment in which aircraft structures generally operate. The use of INSIM to develop inspection strategies which aim to minimize service failures is demonstrated. Damage-tolerance methodology, inspection thresholds and customized inspections are simulated using the probability of failure as the driving parameter.

  7. Probabilistic inspection strategies for minimizing service failures

    Science.gov (United States)

    Brot, Abraham

    1994-01-01

    The INSIM computer program is described which simulates the 'limited fatigue life' environment in which aircraft structures generally operate. The use of INSIM to develop inspection strategies which aim to minimize service failures is demonstrated. Damage-tolerance methodology, inspection thresholds and customized inspections are simulated using the probability of failure as the driving parameter.

  8. Optimizing service failure and damage control

    OpenAIRE

    Halbheer, D; Gartner, D; Gerstner, E; Koenigsberg, O

    2018-01-01

    Should a provider deliver a reliable service or should it allow for occasional service failures? This paper derives conditions under which randomizing service quality can\\ud benefit the provider and society. In addition to cost considerations, heterogeneity in customer damages from service failures allows the provider to generate profit\\ud from selling damage prevention services or offering compensation to high-damage customers. This strategy is viable even when reputation counts and markets ...

  9. Premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Vujović Svetlana

    2012-01-01

    Full Text Available Premature ovarian failure (POF is the occurrence of hypergonadotropic hypoestrogenic amenorrhea in women under the age of forty years. It is idiopathic in 74-90% patients. Known cases can be divided into primary and secondary POF. In primary POF genetic aberrations can involve the X chromosome (monosomy, trisomy, translocations, deletions or autosomes. Genetic mechanisms include reduced gene dosage and non-specific chromosome effects impairing meiosis, decreasing the pool of primordial follicles and increasing atresia due to apoptosis or failure of follicle maturation. Autoimmune ovarian damage is caused by alteration of T-cell subsets and T-cell mediated injury, increase of autoantibody producing B-cells, a low number of effector/cytotoxic lymphocyte, which decreases the number and activity of natural killer cells. Bilateral oophorectomy, chemotherapy, radiotherapy and infections cause the secondary POF. Symptoms of POF include irritability, nervousness, loss of libido, depression, lack of concentration, hot flushes, weight gaining, dry skin, vaginal dryness, frequent infections etc. The diagnosis is confirmed by the level of FSH of over 40 IU/L and estradiol below 50 pmol/L in women aged below 40 years. Biochemical and other hormonal analysis (free thyroxin, TSH, prolactin, testosterone, karyotype (<30 years of age, ultrasound of the breasts and pelvis are advisable. Optimal therapy is combined estrogen progestagen therapy given in a sequential rhythm, after excluding absolute contraindications. Testosterone can be added to adnexectomized women and those with a low libido. Sequential estrogen progestagen replacement therapy is the first line therapy for ovulation induction in those looking for pregnancy and after that oocyte donation will be advised. Appropriate estro-progestagen therapy improves the quality of life and prevents complications such as cardiovascular diseases, osteoporosis, stroke etc.

  10. [External quality assurance in inpatient medical rehabilitation and prevention centers for mothers, fathers and children: development of instruments for assessing structural quality].

    Science.gov (United States)

    Saupe-Heide, M; Gerlich, C; Lukasczik, M; Musekamp, G; Neuderth, S; Vogel, H

    2013-12-01

    As required by German law, inpatient institutions offering prevention and rehabilitation measures for mothers, fathers and children are obliged to implement external quality assurance measures. In 2 pilot projects funded by the German federal association of health insurance funds, external quality assurance procedures for in-hospital prevention and rehabilitation of mothers and fathers were analyzed with the aim of developing a set of instruments for the description of structural characteristics in this area of health care and to evaluate its appropriateness. Concerning structure-related quality, the project included a) designing and evaluating a questionnaire, b) the definition of assessment criteria for subsequent comparative data analyses, and c) the description and documentation of the current state in the field of rehabilitation and prevention for mothers, fathers and children. To document structural quality comprehensively, a modular questionnaire was developed and tested in a survey of 115 inpatient prevention and rehabilitation institutions for mothers, fathers and children. Involving an expert panel, preliminary basic and selection criteria were defined in order to assure a conducive assessment with regard to structural attributes. The majority of institutions had provider agreements for both prevention and rehabilitation. Measures for mothers/fathers with children were predominant; only 7 institutions exclusively treated mothers and fathers. Institution sizes varied strongly. Major indications included psychosomatics, dermatology, and pneumology. Overall, structural conditions of the institutions showed a high standard. Potential for development was found with regard to some aspects of the conceptual framework of institutional practice and the implementation of the International Classification of Functioning, Disability and Health (ICF) in diagnostics. In this article, the degrees of fulfillment with relation to the structural dimensions are presented

  11. The interaction of NDE and failure analysis

    International Nuclear Information System (INIS)

    Nichols, R.W.

    1988-01-01

    This paper deals with the use of Non-Destructive Examination (NDE) and failure analysis for the assessment of the structural integrity. It appears that failure analysis enables to know whether NDE is required or not, and can help to direct NDE into the most useful directions by identifying the areas where it is most important that defects are absent. It also appears that failure analysis can help the operator to decide which NDE method is best suited to the component studied and provides detailed specifications for this NDE method. The interaction between failure analysis and NDE is then described. (TEC)

  12. Structural damages prevention of the ITER vacuum vessel and ports by elasto-plastic analysis with regards to RCC-MR

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jean-Marc, E-mail: jean-marc.martinez@iter.org [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Jun, Chang Hoon; Portafaix, Christophe; Alekseev, Alexander; Sborchia, Carlo; Choi, Chang-Ho [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St. Paul Lez Durance Cedex (France); Albin, Vincent [SOM Calcul – Groupe ORTEC, 121 ancien Chemin de Cassis – Immeuble Grand Pré, 13009 Marseille (France); Borrelly, Stephane [Sogeti High Tech, RE2, 180 rue René Descartes, Le Millenium – Bat C, 13857 Aix en Provence (France); Cambazar, Magali [Assystem EOS, 117 rue Jacquard, 84120 Pertuis (France); Gaucher, Thomas [SOM Calcul – Groupe ORTEC, 121 ancien Chemin de Cassis – Immeuble Grand Pré, 13009 Marseille (France); Sfarni, Samir; Tailhardat, Olivier [Assystem EOS, 117 rue Jacquard, 84120 Pertuis (France)

    2015-10-15

    Highlights: • ITER vacuum vessel (VV) is a part of the first barrier to confine the plasma. • ITER VV as NPE necessitates a third party organization authorized by the French nuclear regulator to assure design, fabrication, and conformance testing and quality assurance, i.e. ANB. • Several types of damages have to be prevented in order to guarantee the structural integrity with regards to RCC-MR. • It is usual to employ non-linear analysis when the “classical” elastic analysis reaches its limit of linear application. • Several structural analyses were performed with many different global and local models of the whole ITER VV. - Abstract: Several types of damages have to be prevented in order to guarantee the structural integrity of a structure with regards to RCC-MR; the P-type damages which can result from the application to a structure of a steadily and regularly increasing loading or a constant loading and the S-type damages during operational loading conditions which can only result from repeated application of loadings associated to the progressive deformations and fatigue. Following RCC-MR, the S-type damages prevention has to be started only when the structural integrity is guaranteed against P-type damages. The verification of the last one on the ITER vacuum vessel and ports has been performed by limit analysis with elasto-(perfectly)plastic material behavior. It is usual to employ non-linear analysis when the “classical” elastic analysis reaches its limit of linear application. Some elasto-plastic analyses have been performed considering several cyclic loadings to evaluate also more realistic structural margins of the against S-type damages.

  13. Failure analysis for WWER-fuel elements

    International Nuclear Information System (INIS)

    Boehmert, J.; Huettig, W.

    1986-10-01

    If the fuel defect rate proves significantly high, failure analysis has to be performed in order to trace down the defect causes, to implement corrective actions, and to take measures of failure prevention. Such analyses are work-consuming and very skill-demanding technical tasks, which require examination methods and devices excellently developed and a rich stock of experience in evaluation of features of damage. For that this work specifies the procedure of failure analyses in detail. Moreover prerequisites and experimental equipment for the investigation of WWER-type fuel elements are described. (author)

  14. Hydriding failure in water reactor fuel elements

    International Nuclear Information System (INIS)

    Sah, D.N.; Ramadasan, E.; Unnikrishnan, K.

    1980-01-01

    Hydriding of the zircaloy cladding has been one of the important causes of failure in water reactor fuel elements. This report reviews the causes, the mechanisms and the methods for prevention of hydriding failure in zircaloy clad water reactor fuel elements. The different types of hydriding of zircaloy cladding have been classified. Various factors influencing zircaloy hydriding from internal and external sources in an operating fuel element have been brought out. The findings of post-irradiation examination of fuel elements from Indian reactors, with respect to clad hydriding and features of hydriding failure are included. (author)

  15. Plasma membrane disruption: repair, prevention, adaptation

    Science.gov (United States)

    McNeil, Paul L.; Steinhardt, Richard A.

    2003-01-01

    Many metazoan cells inhabit mechanically stressful environments and, consequently, their plasma membranes are frequently disrupted. Survival requires that the cell rapidly repair or reseal the disruption. Rapid resealing is an active and complex structural modification that employs endomembrane as its primary building block, and cytoskeletal and membrane fusion proteins as its catalysts. Endomembrane is delivered to the damaged plasma membrane through exocytosis, a ubiquitous Ca2+-triggered response to disruption. Tissue and cell level architecture prevent disruptions from occurring, either by shielding cells from damaging levels of force, or, when this is not possible, by promoting safe force transmission through the plasma membrane via protein-based cables and linkages. Prevention of disruption also can be a dynamic cell or tissue level adaptation triggered when a damaging level of mechanical stress is imposed. Disease results from failure of either the preventive or resealing mechanisms.

  16. Cost-effectiveness and cost-utility of a structured collaborative disease management in the Interdisciplinary Network for Heart Failure (INH) study.

    Science.gov (United States)

    Neumann, Anja; Mostardt, Sarah; Biermann, Janine; Gelbrich, Götz; Goehler, Alexander; Geisler, Benjamin P; Siebert, Uwe; Störk, Stefan; Ertl, Georg; Angerrmann, Christiane E; Wasem, Jürgen

    2015-04-01

    Non-pharmacological treatment programmes are being developed, in which specialised nurses take care of heart failure (HF) patients. Such disease management programmes might increase survival and quality of life in HF patients, but evidence on their cost-effectiveness remains limited. A prospective economic evaluation piggy-backed onto the randomised controlled Interdisciplinary Network for Heart Failure (INH) Study weighted costs of the intervention HeartNetCare -HF™ (HNC) regarding effectiveness, mortality and quality-adjusted life years (QALYs). To consider uncertainty sensitivity analyses were performed. Compared to usual care (UC), HNC revealed 8,284 euro> per death avoided within the 6 month study follow-up period. The cost-utility analysis showed additional costs of 49,335 euro> per QALY. Although HNC did not reduce short-term re-admission rates of HF patients hospitalised for cardiac decompensation within the first 180 days after discharge, HNC might reduce mortality and increase quality of life in these patients at reasonable costs. Therefore, long-term HNC-effects deserve further evaluation.

  17. Heart failure - home monitoring

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000113.htm Heart failure - home monitoring To use the sharing features on this page, please enable JavaScript. Heart failure is a condition in which the heart is ...

  18. Real System Failures

    Data.gov (United States)

    National Aeronautics and Space Administration — This resource area contains descriptions of actual electronic systems failure scenarios with an emphasis on the diversity of failure modes and effects that can...

  19. Light water reactor lower head failure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rempe, J.L.; Chavez, S.A.; Thinnes, G.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States)] [and others

    1993-10-01

    This document presents the results from a US Nuclear Regulatory Commission-sponsored research program to investigate the mode and timing of vessel lower head failure. Major objectives of the analysis were to identify plausible failure mechanisms and to develop a method for determining which failure mode would occur first in different light water reactor designs and accident conditions. Failure mechanisms, such as tube ejection, tube rupture, global vessel failure, and localized vessel creep rupture, were studied. Newly developed models and existing models were applied to predict which failure mechanism would occur first in various severe accident scenarios. So that a broader range of conditions could be considered simultaneously, calculations relied heavily on models with closed-form or simplified numerical solution techniques. Finite element techniques-were employed for analytical model verification and examining more detailed phenomena. High-temperature creep and tensile data were obtained for predicting vessel and penetration structural response.

  20. Light water reactor lower head failure analysis

    International Nuclear Information System (INIS)

    Rempe, J.L.; Chavez, S.A.; Thinnes, G.L.

    1993-10-01

    This document presents the results from a US Nuclear Regulatory Commission-sponsored research program to investigate the mode and timing of vessel lower head failure. Major objectives of the analysis were to identify plausible failure mechanisms and to develop a method for determining which failure mode would occur first in different light water reactor designs and accident conditions. Failure mechanisms, such as tube ejection, tube rupture, global vessel failure, and localized vessel creep rupture, were studied. Newly developed models and existing models were applied to predict which failure mechanism would occur first in various severe accident scenarios. So that a broader range of conditions could be considered simultaneously, calculations relied heavily on models with closed-form or simplified numerical solution techniques. Finite element techniques-were employed for analytical model verification and examining more detailed phenomena. High-temperature creep and tensile data were obtained for predicting vessel and penetration structural response

  1. Acute liver failure

    DEFF Research Database (Denmark)

    Larsen, Fin Stolze; Bjerring, Peter Nissen

    2011-01-01

    Acute liver failure (ALF) results in a multitude of serious complications that often lead to multi-organ failure. This brief review focuses on the pathophysiological processes in ALF and how to manage these.......Acute liver failure (ALF) results in a multitude of serious complications that often lead to multi-organ failure. This brief review focuses on the pathophysiological processes in ALF and how to manage these....

  2. Creating a Community of Practice to Prevent Suicide Through Multiple Channels: Describing the Theoretical Foundations and Structured Learning of PC CARES.

    Science.gov (United States)

    Wexler, Lisa; McEachern, Diane; DiFulvio, Gloria; Smith, Cristine; Graham, Louis F; Dombrowski, Kirk

    2016-01-01

    It is critical to develop practical, effective, ecological, and decolonizing approaches to indigenous suicide prevention and health promotion for the North American communities. The youth suicide rates in predominantly indigenous small, rural, and remote Northern communities are unacceptably high. This health disparity, however, is fairly recent, occurring over the last 50 to 100 years as communities experienced forced social, economic, and political change and intergenerational trauma. These conditions increase suicide risk and can reduce people's access to shared protective factors and processes. In this context, it is imperative that suicide prevention includes--at its heart--decolonization, while also utilizing the "best practices" from research to effectively address the issue from multiple levels. This article describes such an approach: Promoting Community Conversations About Research to End Suicide (PC CARES). PC CARES uses popular education strategies to build a "community of practice" among local and regional service providers, friends, and families that fosters personal and collective learning about suicide prevention in order to spur practical action on multiple levels to prevent suicide and promote health. This article will discuss the theoretical underpinnings of the community intervention and describe the form that PC CARES takes to structure ongoing dialogue, learning, solidarity, and multilevel mobilization for suicide prevention. © The Author(s) 2016.

  3. Load dependent diastolic dysfunction in heart failure

    NARCIS (Netherlands)

    Gillebert, T. C.; Leite-Moreira, A. F.; de Hert, S. G.

    2000-01-01

    Congestive heart failure may result from cardiovascular overload, from systolic or from diastolic dysfunction. Diastolic left ventricular dysfunction may result from structural resistance to filling such as induced by pericardial constraint, right ventricular compression, increased chamber stiffness

  4. In Support of Failure

    Science.gov (United States)

    Carr, Allison

    2013-01-01

    In this essay, I propose a concerted effort to begin devising a theory and pedagogy of failure. I review the discourse of failure in Western culture as well as in composition pedagogy, ultimately suggesting that failure is not simply a judgement or indication of rank but is a relational, affect-bearing concept with tremendous relevance to…

  5. Acute Liver Failure

    Science.gov (United States)

    ... begins in or spreads to your liver can cause your liver to fail. Shock. Overwhelming infection (sepsis) and shock can severely impair blood flow to the liver, causing liver failure. Many cases of acute liver failure have no apparent ... liver failure often causes complications, including: ...

  6. Structural failures of the blood–gas barrier and the epithelial–epithelial cell connections in the different vascular regions of the lung of the domestic fowl, Gallus gallus variant domesticus, at rest and during exercise

    Science.gov (United States)

    Maina, John N.; Jimoh, Sikiru A.

    2013-01-01

    Summary Structural failure of blood–gas barrier (BGB) and epithelial–epithelial cell connections (EECCs) in different vascular regions of the exchange tissue of the lung was studied in rested and exercised chickens. The number of red blood cells (nRBCs) was counted and protein concentration (PC) measured after lavaging the respiratory system, and blood was sampled to determine the blood lactate levels (BLLs). The numbers of complete BGB breaks (nBGBBs) and those of the EECCs (nEECCBs) were counted in the different vascular territories of the lung. The nRBCs and the PCs increased with increasing exercise intensities but the rate of increase decreased at higher workloads. From rest to the fastest experimental treadmill speed of 2.95 m.sec−1, BLLs increased 4-fold. In all cases, the nEECCBs exceeded those of the BGB, showing that structurally the BGB is relatively weaker than the EECC. The increase in the number of breaks with increasing exercise can be attributed to increase in the pulmonary capillary blood pressure (PCBP) from faster heart rates and higher cardiac outputs, while the leveling out of the measurements made at higher workloads may have arisen from hemodynamic changes that initially ensued from exudation of blood plasma and then flow of blood into the air capillaries on failure of the BGB. The relative differences in the nBGBBs and the nEECCBs in the different vascular regions of the lung were ascribed to diameters of the branches and their points of origin and angles of bifurcation from the pulmonary artery. Presence of RBCs in the air capillaries of the lungs of rested chickens showed that failure of the BGB commonly occurs even in healthy and unstressed birds. Rapid repair and/or defense responses, which were observed, may explain how birds cope with mechanical injuries of the BGB. PMID:23519074

  7. Structural failures of the blood-gas barrier and the epithelial-epithelial cell connections in the different vascular regions of the lung of the domestic fowl, Gallus gallus variant domesticus, at rest and during exercise.

    Science.gov (United States)

    Maina, John N; Jimoh, Sikiru A

    2013-03-15

    Structural failure of blood-gas barrier (BGB) and epithelial-epithelial cell connections (EECCs) in different vascular regions of the exchange tissue of the lung was studied in rested and exercised chickens. The number of red blood cells (nRBCs) was counted and protein concentration (PC) measured after lavaging the respiratory system, and blood was sampled to determine the blood lactate levels (BLLs). The numbers of complete BGB breaks (nBGBBs) and those of the EECCs (nEECCBs) were counted in the different vascular territories of the lung. The nRBCs and the PCs increased with increasing exercise intensities but the rate of increase decreased at higher workloads. From rest to the fastest experimental treadmill speed of 2.95 m.sec(-1), BLLs increased 4-fold. In all cases, the nEECCBs exceeded those of the BGB, showing that structurally the BGB is relatively weaker than the EECC. The increase in the number of breaks with increasing exercise can be attributed to increase in the pulmonary capillary blood pressure (PCBP) from faster heart rates and higher cardiac outputs, while the leveling out of the measurements made at higher workloads may have arisen from hemodynamic changes that initially ensued from exudation of blood plasma and then flow of blood into the air capillaries on failure of the BGB. The relative differences in the nBGBBs and the nEECCBs in the different vascular regions of the lung were ascribed to diameters of the branches and their points of origin and angles of bifurcation from the pulmonary artery. Presence of RBCs in the air capillaries of the lungs of rested chickens showed that failure of the BGB commonly occurs even in healthy and unstressed birds. Rapid repair and/or defense responses, which were observed, may explain how birds cope with mechanical injuries of the BGB.

  8. Structural failures of the blood–gas barrier and the epithelial–epithelial cell connections in the different vascular regions of the lung of the domestic fowl, Gallus gallus variant domesticus, at rest and during exercise

    Directory of Open Access Journals (Sweden)

    John N. Maina

    2013-01-01

    Structural failure of blood–gas barrier (BGB and epithelial–epithelial cell connections (EECCs in different vascular regions of the exchange tissue of the lung was studied in rested and exercised chickens. The number of red blood cells (nRBCs was counted and protein concentration (PC measured after lavaging the respiratory system, and blood was sampled to determine the blood lactate levels (BLLs. The numbers of complete BGB breaks (nBGBBs and those of the EECCs (nEECCBs were counted in the different vascular territories of the lung. The nRBCs and the PCs increased with increasing exercise intensities but the rate of increase decreased at higher workloads. From rest to the fastest experimental treadmill speed of 2.95 m.sec−1, BLLs increased 4-fold. In all cases, the nEECCBs exceeded those of the BGB, showing that structurally the BGB is relatively weaker than the EECC. The increase in the number of breaks with increasing exercise can be attributed to increase in the pulmonary capillary blood pressure (PCBP from faster heart rates and higher cardiac outputs, while the leveling out of the measurements made at higher workloads may have arisen from hemodynamic changes that initially ensued from exudation of blood plasma and then flow of blood into the air capillaries on failure of the BGB. The relative differences in the nBGBBs and the nEECCBs in the different vascular regions of the lung were ascribed to diameters of the branches and their points of origin and angles of bifurcation from the pulmonary artery. Presence of RBCs in the air capillaries of the lungs of rested chickens showed that failure of the BGB commonly occurs even in healthy and unstressed birds. Rapid repair and/or defense responses, which were observed, may explain how birds cope with mechanical injuries of the BGB.

  9. Failure Prediction And Detection In Cloud Datacenters

    Directory of Open Access Journals (Sweden)

    Purvil Bambharolia

    2017-09-01

    Full Text Available Cloud computing is a novel technology in the field of distributed computing. Usage of Cloud computing is increasing rapidly day by day. In order to serve the customers and businesses satisfactorily fault occurring in datacenters and servers must be detected and predicted efficiently in order to launch mechanisms to tolerate the failures occurred. Failure in one of the hosted datacenters may propagate to other datacenters and make the situation worse. In order to prevent such situations one can predict a failure proliferating throughout the cloud computing system and launch mechanisms to deal with it proactively. One of the ways to predict failures is to train a machine to predict failure on the basis of messages or logs passed between various components of the cloud. In the training session the machine can identify certain message patterns relating to failure of data centers. Later on the machine can be used to check whether a certain group of message logs follow such patterns or not. Moreover each cloud server can be defined by a state which indicates whether the cloud is running properly or is facing some failure. Parameters such as CPU usage memory usage etc. can be maintained for each of the servers. Using this parameters we can add a layer of detection where in we develop a decision tree based on these parameters which can classify whether the passed in parameters to the decision tree indicate failure state or proper state.

  10. Heart failure in children - overview

    Science.gov (United States)

    Congestive heart failure - children; Cor pulmonale - children; Cardiomyopathy - children; CHF - children; Congenital heart defect - heart failure in children; Cyanotic heart disease - heart failure in children; Birth ...

  11. An Investigation of Digital Instrumentation and Control System Failure Modes

    International Nuclear Information System (INIS)

    Korsah, Kofi; Cetiner, Mustafa Sacit; Muhlheim, Michael David; Poore, Willis P. III

    2010-01-01

    A study sponsored by the Nuclear Regulatory Commission study was conducted to investigate digital instrumentation and control (DI and C) systems and module-level failure modes using a number of databases both in the nuclear and non-nuclear industries. The objectives of the study were to obtain relevant operational experience data to identify generic DI and C system failure modes and failure mechanisms, and to obtain generic insights, with the intent of using results to establish a unified framework for categorizing failure modes and mechanisms. Of the seven databases studied, the Equipment Performance Information Exchange database was found to contain the most useful data relevant to the study. Even so, the general lack of quality relative to the objectives of the study did not allow the development of a unified framework for failure modes and mechanisms of nuclear I and C systems. However, an attempt was made to characterize all the failure modes observed (i.e., without regard to the type of I and C equipment under consideration) into common categories. It was found that all the failure modes identified could be characterized as (a) detectable/preventable before failures, (b) age-related failures, (c) random failures, (d) random/sudden failures, or (e) intermittent failures. The percentage of failure modes characterized as (a) was significant, implying that a significant reduction in system failures could be achieved through improved online monitoring, exhaustive testing prior to installation, adequate configuration control or verification and validation, etc.

  12. Left atrial appendage occlusion with Amplatzer Cardio Plug is an acceptable therapeutic option for prevention of stroke recurrence in patients with non-valvular atrial fibrillation and contraindication or failure of oral anticoagulation with acenocumarol

    OpenAIRE

    Hawkes, Maximiliano A.; Pertierra, Lucía; Rodriguez-Lucci, Federico; Pujol-Lereis, Virginia A.; Ameriso, Sebastián F.

    2016-01-01

    ABSTRACT Left atrial appendage occlusion (LAAO) appears as a therapeutic option for some atrial fibrillation patients not suitable for oral anticoagulation because an increased hemorrhagic risk or recurrent ischemic events despite anticoagulant treatment. Methods Report of consecutive atrial fibrillation patients treated with LAAO with Amplatzer Cardio Plug because contraindication or failure of oral anticoagulation with acenocumarol. CHA2DS2VASC, HAS-BLED, NIHSS, mRS, procedural complicati...

  13. Unpacking the ‘structural’ in a structural approach for HIV prevention among female sex workers: A case study from China

    Science.gov (United States)

    Huang, Yingying; Muessig, Kathryn E.; Zhang, Ning; Maman, Suzanne

    2015-01-01

    Interventions for HIV prevention among female sex workers (FSWs) in China focus on HIV/sexually transmitted infection (STI) and individual behaviour change. An occupational health framework facilitates intervention across an array of health issues FSWs face including HIV/STI, violence, reproductive health, stigma and substance use. Through a case study of a community-based Jiaozhou (JZ) FSW programme, we developed a conceptual framework incorporating global discussions of structural approaches to HIV prevention with the specific social and structural contexts identified among FSWs in China. Based on ethnographic fieldwork between August 2010 and May 2013, we describe the evolution of this programme to its current occupational health focus and unpack the intervention strategies. We describe the critical features of the programme that have fostered success among FSWs including high-quality clinical services provided within a welcoming setting, responsive outreach work through staff and trained FSW peers, interpersonal and community-level engagement aimed at changing the local social and structural environments of sex work and tailored health education materials. This intervention differs from other projects in China by adopting a more holistic approach to FSW health that incorporates social issues. It also demonstrates the feasibility of structural interventions among FSWs even within an environment that has strong anti-prostitution policies. PMID:25742611

  14. Intestinal Failure (Short Bowel Syndrome)

    Science.gov (United States)

    Intestinal Failure (Short Bowel Syndrome) What is intestinal failure? Intestinal failure occurs when a significant portion of the small ... intestine does. Who is at risk for intestinal failure? N Babies (usually premature) who have had surgery ...

  15. An Experimental Investigation On Minimum Compressive Strength Of Early Age Concrete To Prevent Frost Damage For Nuclear Power Plant Structures In Cold Climates

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Kyungtaek; Kim, Dogyeum; Park, Chunjin; Ryu, Gumsung; Park, Jungjun; Lee, Janghwa [Korea Institute Construction Technology, Goyang (Korea, Republic of)

    2013-06-15

    Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates.

  16. An Experimental Investigation On Minimum Compressive Strength Of Early Age Concrete To Prevent Frost Damage For Nuclear Power Plant Structures In Cold Climates

    International Nuclear Information System (INIS)

    Koh, Kyungtaek; Kim, Dogyeum; Park, Chunjin; Ryu, Gumsung; Park, Jungjun; Lee, Janghwa

    2013-01-01

    Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates

  17. Evaluation of Failure Strength of Woven CFRP Composite Plate Subject to Axial Load by Tan-Cheng Failure Criterion

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Young; Park, Hong Sun; Kang, Min Sung; Lee, Woo Hyung; Choi, Jung Hun; Koo, Jae Mean; Seok, Chang Sung [Sungkyunkwan University, Suwon (Korea, Republic of)

    2009-04-15

    In the manufacture of CFRP(Carbon Fiber Reinforced Polymer Composite) composite structures, various independent components join by bolts and pins. Holes for bolts and pins have an effect on the failure strength of such structures, because those act as notches in structures. The failure characteristic of such structures are different from those of plain plate subject to remote load. In this paper, tensile properties of woven CFRP composite plates with laminates of 0 .deg., 30 .deg. and 45 .deg. were obtained according to ASTM D 3039. By using obtained tensile failure strength and Tan-Cheng failure criterion, tensile failure strength of CFRP laminate with arbitrary fiber angle were evaluated. Also, the degradation of tensile properties by center hole({Phi}10mm) with a remote load was evaluated and the failure strengths were applied to Tan's failure criterion, similarly.

  18. Evaluation of Failure Strength of Woven CFRP Composite Plate Subject to Axial Load by Tan-Cheng Failure Criterion

    International Nuclear Information System (INIS)

    Kim, Sang Young; Park, Hong Sun; Kang, Min Sung; Lee, Woo Hyung; Choi, Jung Hun; Koo, Jae Mean; Seok, Chang Sung

    2009-01-01

    In the manufacture of CFRP(Carbon Fiber Reinforced Polymer Composite) composite structures, various independent components join by bolts and pins. Holes for bolts and pins have an effect on the failure strength of such structures, because those act as notches in structures. The failure characteristic of such structures are different from those of plain plate subject to remote load. In this paper, tensile properties of woven CFRP composite plates with laminates of 0 .deg., 30 .deg. and 45 .deg. were obtained according to ASTM D 3039. By using obtained tensile failure strength and Tan-Cheng failure criterion, tensile failure strength of CFRP laminate with arbitrary fiber angle were evaluated. Also, the degradation of tensile properties by center hole(Φ10mm) with a remote load was evaluated and the failure strengths were applied to Tan's failure criterion, similarly

  19. Investigation on multilayer failure mechanism of RPV with a high temperature gradient from core meltdown scenario

    Energy Technology Data Exchange (ETDEWEB)

    Jianfeng, Mao, E-mail: jianfeng-mao@163.com [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Remanufacturing, Ministry of Education (China); Xiangqing, Li [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Shiyi, Bao, E-mail: bsy@zjut.edu.cn [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Remanufacturing, Ministry of Education (China); Lijia, Luo [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Zengliang, Gao [Institute of Process Equipment and Control Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Engineering Research Center of Process Equipment and Remanufacturing, Ministry of Education (China)

    2016-12-15

    Highlights: • The multilayer failure mechanism is investigated for RPV under CHF. • Failure time and location of RPV are predicted under various SA scenarios. • The structural behaviors are analyzed in depth for creep and plasticity. • The effect of internal pressure and temperature gradient is considered. • The structural integrity of RPV is secured within the required 72 creep hours. - Abstract: The Fukushima accident shows that in-vessel retention (IVR) of molten core debris has not been appropriately assessed, and a certain pressure (up to 8.0 MPa) still exists inside the reactor pressure vessel (RPV). In the traditional concept of IVR, the pressure is supposed to successfully be released, and the temperature distributed among the wall thickness is assumed to be uniform. However, this concept is seriously challenged by reality of Fukushima accident with regard to the existence of both internal pressure and high temperature gradient. Therefore, in order to make the IVR mitigation strategy succeed, the numerical investigation of the lower head behavior and its failure has been performed for several internal pressures under high temperature gradient. According to some requirements in severe accident (SA) management of RPV, it should be ensured that the IVR mitigation takes effect in preventing the failure of the structure within a period of 72 h. Subsequently, the failure time and location have to be predicted under the critical heat flux (CHF) loading condition for lower head, since the CHF is limit thermal boundary before the melt-through of RPV. In illustrating the so called ‘multilayer failure mechanism’, the structural behaviors of RPV are analyzed in terms of the stress, creep strain, deformation, damage on selected paths.

  20. Investigation on multilayer failure mechanism of RPV with a high temperature gradient from core meltdown scenario

    International Nuclear Information System (INIS)

    Jianfeng, Mao; Xiangqing, Li; Shiyi, Bao; Lijia, Luo; Zengliang, Gao

    2016-01-01

    Highlights: • The multilayer failure mechanism is investigated for RPV under CHF. • Failure time and location of RPV are predicted under various SA scenarios. • The structural behaviors are analyzed in depth for creep and plasticity. • The effect of internal pressure and temperature gradient is considered. • The structural integrity of RPV is secured within the required 72 creep hours. - Abstract: The Fukushima accident shows that in-vessel retention (IVR) of molten core debris has not been appropriately assessed, and a certain pressure (up to 8.0 MPa) still exists inside the reactor pressure vessel (RPV). In the traditional concept of IVR, the pressure is supposed to successfully be released, and the temperature distributed among the wall thickness is assumed to be uniform. However, this concept is seriously challenged by reality of Fukushima accident with regard to the existence of both internal pressure and high temperature gradient. Therefore, in order to make the IVR mitigation strategy succeed, the numerical investigation of the lower head behavior and its failure has been performed for several internal pressures under high temperature gradient. According to some requirements in severe accident (SA) management of RPV, it should be ensured that the IVR mitigation takes effect in preventing the failure of the structure within a period of 72 h. Subsequently, the failure time and location have to be predicted under the critical heat flux (CHF) loading condition for lower head, since the CHF is limit thermal boundary before the melt-through of RPV. In illustrating the so called ‘multilayer failure mechanism’, the structural behaviors of RPV are analyzed in terms of the stress, creep strain, deformation, damage on selected paths.

  1. Hospital organisation, management, and structure for prevention of health-care-associated infection: a systematic review and expert consensus.

    Science.gov (United States)

    Zingg, Walter; Holmes, Alison; Dettenkofer, Markus; Goetting, Tim; Secci, Federica; Clack, Lauren; Allegranzi, Benedetta; Magiorakos, Anna-Pelagia; Pittet, Didier

    2015-02-01

    Despite control efforts, the burden of health-care-associated infections in Europe is high and leads to around 37,000 deaths each year. We did a systematic review to identify crucial elements for the organisation of effective infection-prevention programmes in hospitals and key components for implementation of monitoring. 92 studies published from 1996 to 2012 were assessed and ten key components identified: organisation of infection control at the hospital level; bed occupancy, staffing, workload, and employment of pool or agency nurses; availability of and ease of access to materials and equipment and optimum ergonomics; appropriate use of guidelines; education and training; auditing; surveillance and feedback; multimodal and multidisciplinary prevention programmes that include behavioural change; engagement of champions; and positive organisational culture. These components comprise manageable and widely applicable ways to reduce health-care-associated infections and improve patients' safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Dopamine in heart failure and critical care

    NARCIS (Netherlands)

    Smit, AJ

    Dopamine is widely used in critical care to prevent renal function loss. Nevertheless sufficient evidence is still lacking of reduction in end points like mortality or renal replacement therapy. Dopaminergic treatment in chronic heart failure (CHF) has provided an example of unexpected adverse

  3. Effect of conformational propensity of peptide antigens in their interaction with MHC class II molecules. Failure to document the importance of regular secondary structures

    DEFF Research Database (Denmark)

    Sette, A; Lamont, A; Buus, S

    1989-01-01

    In an attempt to define some of the conformational requirements for binding of the antigenic peptide OVA 323-336 to purified IAd molecules, three distinct experimental approaches were applied. First, the effect of introducing proline or glycine residues within the region of OVA 323-336 crucial...... for its IAd binding capacity was analyzed. In most instances these substitutions had little or no effect, suggesting that neither alpha-helical nor beta-sheet regular structures may be strictly required for productive interaction with MHC molecules. Some of the same substitutions were also found to have...... no effect on the capacity of the peptide to stimulate OVA 323-336 specific T cell hybridomas, suggesting that regular structures such as alpha-helices or beta-sheets may not be strictly required for T cell stimulation, either. Second, we introduced, within the OVA 323-336 molecule, structural modifications...

  4. A new mode of clinical failure of porous tantalum rod

    Directory of Open Access Journals (Sweden)

    Oh Kwang-Jun

    2010-01-01

    Full Text Available The area of osteonecrosis of the head of femur affected by the disease process varies from a small localized lesion to a global lesion. Without specific treatment 80% of the clinically diagnosed cases will progress, and most will eventually require arthroplasty. Therefore the goal is to diagnose and treat the condition in the earliest stage. A number of surgical procedures have been described to retard or prevent progression of the disease and to preserve the femoral head. An implant made of porous tantalum has been developed to function as a structural graft to provide mechanical support to the subchondral plate of the necrotic femoral head, and possibly allow bone growth into the avascular region. Porous tantalum implant failure with associated radiological progression of the disease is reported in the literature; however, there is no report of clinical failure of the implant without radiological progression of the disease. We report a case of clinical failure of porous tantalum implant, seven months after surgery without any radiological progression of the disease, and with histopathological evidence of new bone formation around the porous tantalum implant. The patient was succesfully treated by total hip arthroplasty.

  5. Gender-specific changes in laboratory indexes and structural parameters of the left ventricle myocardium in chronic heart failure on the background of diabetes mellitus type 2 and obesity

    Directory of Open Access Journals (Sweden)

    P. P. Bidzilya

    2015-12-01

    Full Text Available Modern studies have shown that the prevalence of cardiovascular disease and chronic heart failure (CHF specifically, in patients with diabetes mellitus (DM is about 50%. Aim. To study gender-specific changes in laboratory indexes and structural myocardial parameters of left ventricle (LV in CHF on the background of diabetes mellitus (DM type 2. 111 patients with I–III functional class of disease with normal, overweight and abdominal obesity I–III degree were examined. Methods and results. Clinical and biochemical blood tests? glomerular filtration rate were used. Structural parameters of the myocardium were estimated with echocardiography. It is established that in CHF on the background of DM type 2 and obesity there is a tendency to develop anemia and renal dysfunction in women. Structural changes of the myocardium is more pronounced in men and presents the prevalence ofLV hypertrophy and dilatation of the heart cavities. Conclusion. This demonstrates different ways of negative impact of gender factor on the laboratory indexes and structural myocardial parameters in CHF on the background of DM type 2 and obesity.

  6. The relationship of diurnal variability and level of glycemia with structural and functional parameters of heart in patients with chronic heart failure and diabetes mellitus type 2

    Directory of Open Access Journals (Sweden)

    Виктор Денисович Сиволап

    2016-01-01

    Full Text Available An important contribution in the development of diabetes mellitus (DM complications makes not only the chronic hyperglycemia but also the intense diurnal glycemia variability (GV. The aim of research was to assess systolic and diastolic heart functions in patients with chronic heart failure (CHF of ischemic genesis on the background of DM type 2 depending on GV profile and the mean level of glycemia during the last 3 month.Methods: There were examined 65 patients who were divided into groups twice on the different categoric indicators. The first indicator – an intensity of glycemia profile (GP variability, the second – the mean calculated level of glucose concentration in patients during the last 3 month. All patients underwent dopplerechocardiography, the standard declination and the coefficient of GP variations were calculated. An assessment of reliability of the results of statistic study was carried out by nonparametric method.Results: in patients with the high GP variability was detected the reliably greater size of the left atrium, decrease of the left ventricle output fraction, tendency to the transition of diastolic dysfunction from the I type to the II one comparing with the group with low GP variability. There was not revealed any reliable difference between groups or correlative connection of the mean level of glycemia with parameters that characterize contractility and diastolic myocardium function.Conclusions: There was revealed the negative influence of the high glycemia variability on systolic and diastolic heart functions, left atrium size and there was not revealed any reliable influence of the mean level of glycemia on cardiohemodynamics

  7. Tensile failure criteria for fiber composite materials

    Science.gov (United States)

    Rosen, B. W.; Zweben, C. H.

    1972-01-01

    The analysis provides insight into the failure mechanics of these materials and defines criteria which serve as tools for preliminary design material selection and for material reliability assessment. The model incorporates both dispersed and propagation type failures and includes the influence of material heterogeneity. The important effects of localized matrix damage and post-failure matrix shear stress transfer are included in the treatment. The model is used to evaluate the influence of key parameters on the failure of several commonly used fiber-matrix systems. Analyses of three possible failure modes were developed. These modes are the fiber break propagation mode, the cumulative group fracture mode, and the weakest link mode. Application of the new model to composite material systems has indicated several results which require attention in the development of reliable structural composites. Prominent among these are the size effect and the influence of fiber strength variability.

  8. Failure of the Hume-Rothery stabilization mechanism in the Ag5Li8 gamma-brass studied by first-principles FLAPW electronic structure calculations

    International Nuclear Information System (INIS)

    Mizutani, U; Asahi, R; Noritake, T; Sato, H; Takeuchi, T

    2008-01-01

    The first-principles FLAPW (full potential linearized augmented plane wave) electronic structure calculations were performed for the Ag 5 Li 8 gamma-brass, which contains 52 atoms in a unit cell and has been known for many years as one of the most structurally complex alloy phases. The calculations were also made for its neighboring phase AgLi B2 compound. The main objective in the present work is to examine if the Ag 5 Li 8 gamma-brass is stabilized at the particular electrons per atom ratio e/a = 21/13 in the same way as some other gamma-brasses like Cu 5 Zn 8 and Cu 9 Al 4 , obeying the Hume-Rothery electron concentration rule. For this purpose, the e/a value for the Ag 5 Li 8 gamma-brass as well as the AgLi B2 compound was first determined by means of the FLAPW-Fourier method we have developed. It proved that both the gamma-brass and the B2 compound possess an e/a value equal to unity instead of 21/13. Moreover, we could demonstrate why the Hume-Rothery stabilization mechanism fails for the Ag 5 Li 8 gamma-brass and proposed a new stability mechanism, in which the unique gamma-brass structure can effectively lower the band-structure energy by forming heavily populated bonding states near the bottom of the Ag-4d band

  9. Choking Prevention

    Science.gov (United States)

    ... Healthy Living Healthy Living Healthy Living Nutrition Fitness Sports Oral Health Emotional Wellness Growing Healthy Sleep Safety & Prevention Safety & Prevention Safety and Prevention Immunizations At Home ...

  10. A quantitative method for Failure Mode and Effects Analysis

    NARCIS (Netherlands)

    Braaksma, A. J. J.; Meesters, A. J.; Klingenberg, W.; Hicks, C.

    2012-01-01

    Failure Mode and Effects Analysis (FMEA) is commonly used for designing maintenance routines by analysing potential failures, predicting their effect and facilitating preventive action. It is used to make decisions on operational and capital expenditure. The literature has reported that despite its

  11. Civil Liability for Failure to Train to Standard.

    Science.gov (United States)

    Sample, John

    1989-01-01

    Reviews the legal concept of "failure to train to standard" from the context of law enforcement. Responsibility for training is discussed, case examples and examples of monetary judgments are given, and recommendations for preventing and limiting liability for failure to train to standard are presented. (16 references) (LRW)

  12. Evaluation and Management of The Child with Failure to Thrive ...

    African Journals Online (AJOL)

    In this review article, the definition, aetiology, evaluation, differential diagnoses, management, prevention and prognosis of failure to thrive are discussed. Failure to thrive (FTT) is a common problem in paediatric practice, affecting 5-10% of under-fives in developed countries with a higher incidence in developing countries.

  13. A Failure Locus for Hydrogen Assisted Failure

    DEFF Research Database (Denmark)

    Fuentes-Alonso, Sandra; Harris, Zach D.; Burns, James T.

    2017-01-01

    important insight into the failure process, enabling to identify critical values of hydrogen concentration and remote stresses that trigger cracking. The work builds upon previous works by the authors and brings important insight into the technologically important problem of hydrogen assisted cracking....

  14. Bone Marrow Failure Secondary to Cytokinesis Failure

    Science.gov (United States)

    2015-12-01

    SUPPLEMENTARY NOTES 14. ABSTRACT Fanconi anemia (FA) is a human genetic disease characterized by a progressive bone marrow failure and heightened...L. Tian, M. Kahkonen, J. Schwartzentruber, M. Kircher, G. University of Washington Centre for Mendelian , F.C. Consortium, J. Majewski, D.A. Dyment

  15. Failure propagation tests and analysis at PNC

    International Nuclear Information System (INIS)

    Tanabe, H.; Miyake, O.; Daigo, Y.; Sato, M.

    1984-01-01

    Failure propagation tests have been conducted using the Large Leak Sodium Water Reaction Test Rig (SWAT-1) and the Steam Generator Safety Test Facility (SWAT-3) at PNC in order to establish the safety design of the LMFBR prototype Monju steam generators. Test objectives are to provide data for selecting a design basis leak (DBL), data on the time history of failure propagations, data on the mechanism of the failures, and data on re-use of tubes in the steam generators that have suffered leaks. Eighteen fundamental tests have been performed in an intermediate leak region using the SWAT-1 test rig, and ten failure propagation tests have been conducted in the region from a small leak to a large leak using the SWAT-3 test facility. From the test results it was concluded that a dominant mechanism was tube wastage, and it took more than one minute until each failure propagation occurred. Also, the total leak rate in full sequence simulation tests including a water dump was far less than that of one double-ended-guillotine (DEG) failure. Using such experimental data, a computer code, LEAP (Leak Enlargement and Propagation), has been developed for the purpose of estimating the possible maximum leak rate due to failure propagation. This paper describes the results of the failure propagation tests and the model structure and validation studies of the LEAP code. (author)

  16. Failure strength and elastic limit for concrete

    International Nuclear Information System (INIS)

    Robutti, G.; Ronzoni, E.; Ottosen, N.S.

    1979-01-01

    Due to increased demand for realistic analysis of structures such as prestressed concrete reactor vessels and reactor containments, the formulation of general constitutive equations for concrete is of considerable importance. In the field of constitutive equations the correct definition of the limit state represented by the concrete failure surface is a fundamental need. In this paper carried out by a Danish-Italian cooperation, several failure criteria obtained by different authors are compared with failure experimental data obtained with triaxial tests on concrete specimens. Such comparison allow to carry out conclusive considerations on the characteristics of the concrete failure surface and on the advantages and disadvantages of the different criteria. Considerations are also reported on the definition of a limit elastic surface, whose knowledge is of fundamental importance for designers of complex structures in concrete. (orig.)

  17. Review of constitutive models and failure criteria for concrete

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jeong Moon; Choun, Young Sun [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-03-01

    The general behavior, constitutive models, and failure criteria of concrete are reviewed. The current constitutive models for concrete cannot satisfy all of mechanical behavior of concrete. Among several constitutive models, damage models are recommended to describe properly the structural behavior of concrete containment buildings, because failure modes and post-failure behavior are important in containment buildings. A constitutive model which can describe the concrete behavior in tension is required because the containment buildings will reach failure state due to ultimate internal pressure. Therefore, a thorough study on the behavior and models under tension stress state in concrete and reinforced concrete has to be performed. There are two types of failure criteria in containment buildings: structural failure criteria and leakage failure criteria. For reinforced or prestressed concrete containment buildings, concrete cracking does not mean the structural failure of containment building because the reinforcement or post-tensioning system is able to resist tensile stress up to yield stress. Therefore leakage failure criteria will be prior to structural failure criteria, and a strain failure criterion for concrete has to be established. 120 refs., 59 figs., 1 tabs. (Author)

  18. Immune mediated liver failure.

    Science.gov (United States)

    Wang, Xiaojing; Ning, Qin

    2014-01-01

    Liver failure is a clinical syndrome of various etiologies, manifesting as jaundice, encephalopathy, coagulopathy and circulatory dysfunction, which result in subsequent multiorgan failure. Clinically, liver failure is classified into four categories: acute, subacute, acute-on-chronic and chronic liver failure. Massive hepatocyte death is considered to be the core event in the development of liver failure, which occurs when the extent of hepatocyte death is beyond the liver regenerative capacity. Direct damage and immune-mediated liver injury are two major factors involved in this process. Increasing evidence has suggested the essential role of immune-mediated liver injury in the pathogenesis of liver failure. Here, we review the evolved concepts concerning the mechanisms of immune-mediated liver injury in liver failure from human and animal studies. Both innate and adaptive immunity, especially the interaction of various immune cells and molecules as well as death receptor signaling system are discussed. In addition, we highlight the concept of "immune coagulation", which has been shown to be related to the disease progression and liver injury exacerbation in HBV related acute-on-chronic liver failure.

  19. Chronic heart failure

    African Journals Online (AJOL)

    associated with a reduction in morbidity and mortality.3. Clinical picture. The symptoms of heart failure are ... crepitations and a third heart sound gallop, are more predictive, but none of them are 100% diagnostic. Therefore ... some abnormality) in heart failure with reduced ejection fraction. A normal ECG should prompt an ...

  20. Success by Failure

    Science.gov (United States)

    Andrews, Benjamin D.

    2017-01-01

    By taking the step to talk openly about his failure, the author stumbled upon one of several important lessons that he learned from this experience. The author recognized that he did not have to pretend anymore. In this article, the author shares his story of developing a "growth mindset" to overcome his own failure and support his…