bluuebunny/crossref_metadata_2025_split huggingface dataset:
Punching shear tests on steel-fibre-reinforced micro-concrete slabs
Authors: Narayanan R. , Darwish I. Y. S. 
Published: October 2009

Synopsis Investigations of the behaviour and strength characteristics of steel-Jihre-reinforced micro-concrete slabs subjected to punching shear are presented and discussed. A total of 12 simply-supported square slabs were tested. The parameters varied were the volume fraction of the fibres, the amount of tensile reinforcement and the concrete strength. The test results confirm that an increase infibre content improved the shear strength of the slabs; the position of the critical shear perimeter around the loaded area was also influenced by the fibre content. Based on these tests, a design method is suggested for evaluating the punching shear strength of fibre-reinforced concrete slabs. The predictions obtained bythe suggested method are shown to be satisfactory by comparing them with the values observed in the tests carried out by the authors and previous investigators.
A theory of transfer bond resistance of deformed reinforcing bars in concrete under lateral pressure
Authors: Navaratnarajah V. , Speare P. R. S. 
Published: October 2009

Synopsis The basic bond mechanism for reinforcing bars in concrete under external pressure is considered and an existing partly cracked elastic theory for bond resistance is extended to cover both uniform and non-uniform distributions of external pressure. Results obtained from this theory are compared with experimental results at various stages of bond failure. The prediction of pull-out force at 0·1 mm free-end slip is found to be satisfactory.
Shear strength of lightweight aggregate concrete beams: design to BS 8l10
Authors: Clarke J. L. 
Published: October 2009

Synopsis Provisions for the use of structural lightweight aggregate concrete are included in British codes of practice but limitations are applied to the design values that may be used. This paper is concerned with the strength in shear, which is limited in the codes to 80% of that for normal-weight concrete of the same compressive strength. The paper reviews the published test data and describes a series of tests on beams, both with and without shear reinforcement. On the basis of the review and the tests it is concluded that the code provisions are unnecessarily conservative.
Analysis of aggregate interlock behaviour at cracks in reinforced concrete
Authors: Soroushian Parviz , Obaseki Kienuwa , Choi Ki-Bong 
Published: October 2009

Synopsis Analytical methods have been developed for predicting the resistance provided by aggregate interlock against sliding-shear deformations at cracks in reinforced concrete. These methods are shown to be capable of predicting test results with a reasonable accuracy, and they are used for an analytical study of the influence on aggregate interlock behaviour of the initial crack width, concrete compressive strength, maximum aggregate size, and the restraint provided against opening. The relative significance of aggregate interlock compared to the dowel action of reinforcing bars in resisting the sliding-shear action across cracks in reinforced concrete was also assessed analytically.
A comparative study of fracture parameters in notched concrete beams
Authors: Alexander M. G. , Blight G. E. 
Published: October 2009

Synopsis The paper compares a number of fracture parameters, both linear and non-linear, obtained from the results of tests carried out on notched concrete beams with depths varying from 100 to 800mm. The parameters were critically investigated, for their ability to describe concrete fracture. The concept of a ‘fracture process’ is introduced. The type of, fracture process as well as the existence of an extensive microcracked zone ahead of the main crack critically affect values of the measured parameters. It was concluded that none of the existing parameters are entirely satisfactory, due primarily to a lack of true size-independence in the relationships. Parameters must he linked to fracture processes, which, together with the presence of the microcracked zone, implies that ultimately a number of non-linear parameters will suit the concrete fracture problem best.
Heat release characteristics of concrete containing ground granulated slag in simulated large pours
Authors: Coole M. J. 
Published: October 2009

Synopsis Simulated large pour studies in which ground granulated blast furnace slags from three European sources were blended with OPC have shown that both the peak temperature and the time to reach this temperature are strongly injhenced by slag source. With a reactive slag and a moderate level of OPC replacement (20–40%) the temperature rise at the centre of a large pour may be higher than that at the centre of an equivalent OPC pour. Five levels of slag replacement were investigated in concrete with a cement content of 315 kg/m3. The compressive strengths of concrete cubes cast from the same mix and stored under matched curing conditions were also determined. Results obtained with concrete under variable loss, semi-adiabatic conditions were compared with those obtained with pastes under isothermal conditions at a single temperature of 20°C. The isothermal results are of little value in predicting behaviour in large pours and can be quite misleading. It therefore follows that care should be taken when selecting a slag source and a slag level for large concrete pours. Reliance should not be placed on published results obtained with other slags or on isothermal calorimetry carried out at 20°C only.
SRPC and modified concretes subjected to severe sulphuric acid attack
Authors: Fattuhi N. I. , Hughes B. P. 
Published: October 2009

Synopsis Mortar and concrete cubes have been immersed in a channel containing a 3% solution of continuously flowing sulphuric acid. The cementitious materials examined were: ordinary Portland cement containing polyvinyl alcohol (PVA) and pulverized-fuel ash; sulphate-resisting Portland cement, and a proprietary dense mortar. The change in weight with time of each cube was measured for up to 81 days. The effect of the PVA was to preserve the integrity of the cubes, and possibly slow down the rate of acid attack. The rate of acid attack on the SRPC concretes was similar to that on OPC concretes. The dense mortar had much improved resistance to sulphuric acid attack, and the improvement was enhanced with increased volume fraction of aggregate.
A new gas permeameter for measuring the permeability of mortar and concrete
Authors: Cabrera J. G. , Lynsdale C. J. 
Published: October 2009

Synopsis A permeability cell for measuring the permeability of mortar and concrete to gas is described. The problems encountered and overcome during the development of the cell are discussed. The cell is designed to test 25 mm diameter mortar samples but can also be used for 50mm diameter concrete specimens. Specimens of heights between 10 and 50mm can be tested. Measurements using the new cell are highly repeatable and reproducible. The cell is very sensitive to the influence of water/cement ratio, age and replacement of cement by pulverized-fuel ash. It can be used to obtain permeability profiles through the depth of a concrete element in order to evaluate the influence of different curing conditions or curing compounds.
3D finite-element modelling of splitting crack propagation
Authors: Lura P. , Plizzari G. A. , Riva P. 
Published: October 2009

Although many experimental results on bond strength are available and splitting is commonly recognised as an important aspect of bond strength, only a few studies on splitting crack development have been published so far. Although, splitting is a 3D phenomenon, the only measurement easily taken in a test is the splitting crack width on the specimen surface. As a result, the crack development inside the specimen is unmonitored. Such being the limits of testing, finite-element (FE) analysis can be a valuable alternative for the study of splitting crack 3D nature and for a better understanding of bond behaviour. However, FE studies are limited by the intrinsic difficulty in correctly modelling the bond. In fact, the models proposed so far are either too complex or too limited for describing actual anchorages and for studying splitting development. The main purpose of this research work is to develop a 3D FE model in which bond is modelled by a simple kinematic interface. The model developed is useful for establishing rational design criteria for anchorages and splices. Such a model is validated by simulating a series of pull-out tests concerning the interaction between a bar and a stirrup, when the concrete cover is split and the stirrup crosses the splitting plane. The comparison between experimental and numerical results shows that the proposed model describes quite well the behaviour of an anchored bar in terms of both bond–slip response and splitting crack width. In spite of its simplicity, the proposed model can be easily expanded to cover more complex structural cases and to develop more rational criteria for the design of anchorages and splices in RC members.
Magnetic cluster developement in In1−x
MnxSb semiconductor alloys
Authors: Rednic Lidia , Deac Iosif , Dorolti Eugen , Coldea Marin , Rednic Vasile , Neumann Manfred 
Published: October 2009

Abstract
X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and magnetic measurements as a function of applied magnetic field and temperature for In1−x
MnxSb (0.05≤x≤0.2) system are reported. Magnetic measurements performed at high and small magnetic field in ZFC and FC indicate the coexistence of ferromagnetic In1−x
MnxSb solid solution and two types of magnetic cluster: ferromagnetic MnSb and ferrimagnetic Mn2Sb. XPS valence band and Mn 2p core level spectra have confirmed the presence of MnSb and Mn2Sb phases. TEM images show some manganese antimonide phase microinclusions with dimension between (30–40) nm.
New mechanism of solution of the k
B
T-problem in magnetobiology
Authors: Kanokov Zakirjon , Schmelzer Jürn , Nasirov Avazbek 
Published: October 2009

Abstract
The effects of ultralow-frequency or static magnetic and electric fields on biological processes is of huge interest for researchers due to the resonant change of the intensity of biochemical reactions, despite the energy in such fields being small in comparison with the characteristic energy k
B
T of the chemical reactions. In the present work, a simplified model to study the effects of weak static magnetic fields on fluctuations of the random ionic currents in blood is presented with a view to solving the k
B
T problem in magnetobiology. An analytic expression for the kinetic energy of the molecules dissolved in certain liquid media is obtained. The values of the magnetic field leading to resonant effects in capillaries are then estimated. The numerical estimates show that the resonant values of the energy of molecules in capillaries and the aorta are different. These estimates prove that under identical conditions, a molecule in the aorta gets 10−9 times less energy than the molecules in blood capillaries. Therefore, the capillaries are very sensitive to the resonant effect. As the magnetic field approaches the resonant value, the average energy of a molecule localized in a capillary is increased by several orders of magnitude as compared to its thermal energy. This amount of energy is sufficient to cause deterioration of certain chemical bonds.
Left ventricular myxoma: Confusing intracardiac mass in a patient with leukemia in remission
Authors: Tanindi Asli , Tacoy Gulten , Hizal Fatma , Turfan Murat , Ereren Emrah , Oktar Levent , Abaci Adnan 
Published: October 2009

Abstract
Cardiac myxomas are the most common primary benign tumors of the heart and appears particularly in the left atrium. Myxomas exhibit a wide spectrum of symptoms from asymptomatic to very serious according to the localisation of the tumours. Only 5% of these tumours occur in the right and left ventricles. We report an unusual case of a 21-year-old woman with a leukemia in remission, in whom routine transthorasic echocardiographic examination demonstrated an incidental left ventricular mass. The patient underwent successful resection of the left ventricular mass under cardiopulmonary bypass through the left atrial approach. Histopathologic examination was diagnostic for myxoma. In this case, the presentation of the mass was atypical for two reasons: the tumour was a cardiac myxoma in the left ventricular localisation and in a patient with leukemia in remission.
Circulating Leptin and Bone Mineral Density in Rheumatoid Arthritis
Authors: AGUILAR-CHAVEZ ERIKA A. , GAMEZ-NAVA JORGE I. , LOPEZ-OLIVO MARIA A. , GALVAN-MELENDRES SILVIA , CORONA-SANCHEZ ESTHER G. , LOAIZA-CARDENAS CARLOS A. , CELIS ALFREDO , CARDONA-MUÑOZ ERNESTO G. , GONZALEZ-LOPEZ LAURA 
Published: October 2009

Objective.To evaluate the association between circulating leptin and bone mineral density (BMD) in patients with rheumatoid arthritis (RA).Methods.One-hundred thirty postmenopausal women with RA were assessed for body mass index (BMI), disease characteristics, history of drug use, rheumatoid factor, and erythrocyte sedimentation rate (ESR). BMD (g/cm2) was determined in the hip and spine by DEXA. Serum leptin concentrations were measured by ELISA. Spearman’s correlation coefficients (rho) were determined between BMD and leptin and other variables. A multiple regression analysis was used to adjust for confounders.Results.Patients’ serum leptin levels varied widely (range 2–128 ng/ml). Thirty-three patients (25%) had osteoporosis. Higher levels of leptin correlated significantly with BMD in the lumbar spine (rho = 0.17, p = 0.04) and total hip (rho = 0.21, p = 0.01). The variables that were negatively correlated with BMD were age, duration of menopause, and ESR. After adjustment for confounders, leptin was no longer associated with BMD. In the multivariate model, factors that remained associated with BMD in the total hip were age (p = 0.021) and BMI (p = 0.003); and the factors that remained associated with BMD in the lumbar spine were BMI (p = 0.03) and ESR (p = 0.01).Conclusion.No relevant association was found between circulating leptin levels and BMD in patients with RA in this cross-sectional study. Followup studies are needed to evaluate whether abnormal leptin levels confer a risk for fractures due to osteoporosis.
Gout in the Axial Skeleton
Authors: KONATALAPALLI RUKMINI M. , DEMARCO PAUL J. , JELINEK JAMES S. , MURPHEY MARK , GIBSON MICHAEL , JENNINGS BRYAN , WEINSTEIN ARTHUR 
Published: October 2009

Objective.Gout typically affects the peripheral joints of the appendicular skeleton and rarely involves the axial joints. The literature on axial gout is limited to case reports and case series. This preliminary study was conducted to identify the frequency and characteristics of axial gout.Methods.Six hundred thirty medical records with ICD codes 274.0, 274.82, and 274.9 for peripheral gout were reviewed. Ninety-two patients had clinical or crystal-proven gout, of which 64 had prior computed tomography (CT) images of the spine performed for various medical reasons. These CT images were reviewed for features of axial gout, which include vertebral erosions mainly at the discovertebral junction and the facet joints, deposits of tophi, and erosions in the vertebral body, epidural space, ligamentum flavum and pars interarticularis.Results.Nine of the 64 patients had radiographic changes suggestive of axial gout. Lumbar vertebrae were most commonly involved, with facet joint erosions being the most common finding. Isolated involvement of the sacroiliac joints was seen in 2 patients. Axial gout had been diagnosed clinically in only one patient.Conclusion.Radiologic changes of axial gout were more common than recognized clinically, with a frequency of 14%. Since not all patients had CT images, it is possible that the frequency of axial involvement was even greater. A prospective study is needed to further define this process.
Increased Expression of Toll-like Receptors in Aseptic Loose Periprosthetic Tissues and Septic Synovial Membranes Around Total Hip Implants
Authors: TAMAKI YASUNOBU , TAKAKUBO YUYA , GOTO KAORU , HIRAYAMA TOMOYUKI , SASAKI KAN , KONTTINEN YRJÖ T. , GOODMAN STUART B. , TAKAGI MICHIAKI 
Published: October 2009

Objective.Toll-like receptors (TLR) are transmembrane proteins found in various cells. They recognize infectious and endogenous threats, so-called danger signals, that evoke inflammation and assist adaptive immune reactions. It has been suggested that TLR play a role in periprosthetic tissues and arthritic synovium. Our objective was to elucidate tissue localization and functional roles of TLR in periprosthetic tissues in 2 different pathologic conditions, aseptic and septic implant loosening.Methods.For immunohistochemistry studies, aseptic synovial-like membranes of periprosthetic connective tissues (n = 15) and septic synovial capsular tissues (n = 5) were obtained at revision surgery and from salvage of infected totally replaced hips, respectively. Osteoarthritic synovial tissues were used for comparison (n = 5). Samples were processed for immunohistopathologic analyses for tissue colocalization of TLR with CD68 and/or CD15 using theAlexa fluorescent system. Total RNA was isolated from frozen tissues and converted into cDNA, TLR 2, 4, 5 and 9 sequences were amplified, and the products were quantified using real-time polymerase chain reaction.Results.Immunofluorescent staining showed colocalization of TLR 2, 4, 5, and 9 with CD68 in the focal monocyte/macrophage aggregates in aseptic synovial-like membranes from loose total hip replacements. TLR 2, 4, 5, and 9 were also found colocalized with CD15+ polymorphonuclear leukocytes and CD68+ mononuclear cells of the synovial membranes from septic total hip replacements. In osteoarthritic synovial tissues, expression of TLR was found only in vascular cells and mononuclear cells, and the reactivity was weak. mRNA levels of TLR 2, 4, 5, and 9 were increased in both aseptic and septic periprosthetic tissues. TLR 2 and 5 were significantly higher than TLR 4 and 9 in aseptic and septic samples.Conclusion.Peri-implant tissues were well equipped with TLR in both aseptic and septic conditions. TLR 2- and TLR 5-mediated responses seemed to dominate. In aseptic loosening, monocytes/ macrophages were the main TLR-equipped cells apparently responsible for alarmin-induced responses. This could lead to production of inflammatory cytokines and extracellular matrix-degrading proteinases after phagocytosis of wear debris derived from an implant, but in septic cases they eventually respond to microbial components. Thus, inflammatory cells in both aseptic and septic tissues were equipped with TLR, providing them with responsiveness to both endogenous and exogenous TLR ligands.
Six and 12 Weeks Treatment Response Predicts Continuation of Tumor Necrosis Factor Blockade in Rheumatoid Arthritis: An Observational Cohort Study from Southern Sweden
Authors: GÜLFE ANDERS , KRISTENSEN LARS ERIK , GEBOREK PIERRE 
Published: October 2009

Objective.To investigate if treatment response predicts continuation of anti-tumor necrosis factor (TNF) treatment in patients with rheumatoid arthritis (RA).Methods.We investigated if treatment response and/or achieving a certain activity state at 6 weeks or 3 months predicts continuation of treatment in an observational cohort of 1789 anti-TNF-naive patients with established RA disease from southern Sweden.Results.Response to treatment at 6 weeks at overall/American College of Rheumatology (ACR20) or good/major level (except ACR70) significantly predicted drug continuation. Response according to all criteria sets at overall/ACR20 and at good/major/ACR70 level predicted drug continuation at 3 months, as did achieving low disease activity at 3 months irrespective of activity index applied. Remaining in a high disease activity state predicted drug discontinuation at both timepoints and according to all criteria sets.Conclusion.Response criteria may be useful aids in deciding on continuation of TNF blockade in RA as early as after 6 weeks of treatment. The various criteria sets perform similarly.
Patients with Moderate Rheumatoid Arthritis (RA) Achieve Better Disease Activity States with Etanercept Treatment Than Patients with Severe RA
Authors: KEYSTONE EDWARD , FREUNDLICH BRUCE , SCHIFF MICHAEL , LI JUAN , HOOPER MICHELE 
Published: October 2009

Objective.This analysis examined clinical and radiographic responses to methotrexate (MTX), etanercept (ETN), and combination ETN and MTX in patients with moderate versus severe rheumatoid arthritis (RA) in both early and late disease.Methods.Data from the Trial of Etanercept and Methotrexate With Radiographic Patient Outcomes (TEMPO) and the Early Rheumatoid Arthritis trials were used. Patients were classified with moderate or severe RA based on Disease Activity Score including 28-joint count (DAS28). Outcomes included DAS28 remission, DAS28 low disease activity, Health Assessment Questionnaire (HAQ), American College of Rheumatology (ACR) scores, Total Sharp Score (TSS) progression, no radiographic progression (annualized change in TSS ≥ 0), change from baseline in TSS, and the change in TSS for patients who had radiographic progression (TSS > 0).Results.Patients with moderate disease generally achieved better clinical outcomes than patients with severe disease, including significant differences in DAS28 remission, low disease activity, and HAQ ≤0.5 at Month 12. Patients with baseline severe disease had higher ACR and DAS responses than patients with moderate disease.Conclusion.Patients with severe RA disease activity achieved substantial clinical improvement with high-dose MTX and/or ETN treatment, but patients with moderate disease were more likely to reach a lower disease activity state. These findings were independent of disease duration. The results support the opportunity for excellent clinical outcomes, particularly with combination therapy, in patients with moderate RA.