bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experiments on the distortion of steel bars across cracks in reinforced concrete slabs
Authors: Morley C. T. 
Published: July 2012

Summary Long narrow model concrete slabs were bent in such a way that strains were everywhere uniaxial, thus simulating a yield line at different angles to the bars in a layer of mild-steel tensile reinforcement, so that the effect of distortion of steel across cracks could be directly measured. Most slabs were tested with zero membrane force normal to the yield line, but others were tested in proportional loading with different ratios of moment to membrane force. Separate analysis of the stresses in the steel and concrete shows that distortion of steel was insignificant at all stages after cracking.
A three-dimensional stress distribution problem in the anchorage zone of a post-tensioned concrete beam
Authors: Sundara Raja Iyengar K. T. , Yogananda C. V. 
Published: July 2012

Summary The results of a theoretical investigation carried out in the Department of Civil Engineering of the Indian Institute of Science to determine the stress distribution in the anchorage zone of a post-tensioned concrete beam are described. The problem was idealized as that of a circular concrete beam with a co-axial cable duct due to the application of circular concentrated load at one of its ends. A three-dimensional elasticity solution satisfying all the equations is given and the resulting numerical results are compared with those of other investigators.
A consistent limit-analysis theory for reinforced concrete slabs
Authors: Save M. 
Published: July 2012

Summary The paper aims to show that a consistent limit-analysis theory for reinforced concrete slabs can include the recent advances in yield-line theory. It starts by accepting a physical yield criterion for an element of a slab (a bending moment criterion), derives the yield surface in moment space, assumes plastic potential (normality law) and shows that yielding can occur in the form of yield lines and also of yielding regions. The fundamental theorems of limit analysis are then stated. Nodal-force theory is defined and the concept of upper-bound moment field is examined. Connexions between various approaches to nodal-forces formulae are noted, and particular aspects, such as the intersection of yield lines and the existence of torque in the yield lines, are discussed.
Differential thermal analysis in vacuo of pastes of Portland cement and of β-dicalcium silicate
Authors: Mikhail R. Sh. , Hussein A. T. , Gouda V. K. 
Published: July 2012

Summary Differential thermal analysis curves were obtained for a Portland cement paste and a fl-dicalcium silicate paste (β-C2S paste), by heating in vacuo and in air up to 1,200°C. The vacuum thermograms of both pastes showed a first single endotherm at 140 to 143°C which is mainly characteristic for the decomposition of tobermorite gel. For the Portland cement paste, this includes also the decomposition of the smaller amounts of aluminate hydrated salts. A second peak which appeared at 360 to 385°C is due to the decomposition of calcium hydroxide. Thermograms obtained by heating in air differ considerably from those obtained in vacuo. The first endothermal effect which mainly characterizes the decomposition of the tobermorite gel showed more than one peak; and the temperature, shape and area of the peaks are all affected by heating in air. These effects may be due to the reversibility of the reaction and to the liability of the dehydrated products to be rehydrated at an accelerated rate in the presence of air. At high temperatures, DTA in vacuo seems to be a useful technique for resolving some peaks which apparently are fused into a single effect in the air thermogram.
The shear strength of rectangular reinforced and prestressed concrete beams
Authors: Ojha S. K. 
Published: July 2012

Summary This paper describes a method of calculating the shear strength of reinforced and prestressed concrete rectangular beams under one or two point loads. A new failure criterion for the concrete of the compression zone has been developed with the help of the ‘distortion energy’ principle. A comparison with other criteria shows that this hypothesis describes the failure pattern of concrete with reasonable safety. The inclination of shear cracks has been introduced as an independent variable in this method. The expressions developed cover bending failure as a special case. The calculated results show good agreement with experimental evidence.
Tumor Necrosis Factor‐α Inhibits Transforming Growth Factor‐β–Stimulated Myofibroblastic Differentiation and Extracellular Matrix Production in Human Gingival Fibroblasts
Authors: Arancibia Rodrigo , Oyarzún Alejandro , Silva Daniel , Tobar Nicolás , Martínez Jorge , Smith Patricio C. 
Published: July 2012

Background: Fibroblasts play a critical role during wound healing and chronic inflammation through the synthesis and assembly of extracellular matrix (ECM) molecules. These responses may be modulated by soluble cytokines and growth factors present in tissues. In the present study, we evaluate whether transforming growth factor‐β1 (TGF‐β1) and tumor necrosis factor‐α (TNF‐α) modulate myofibroblastic differentiation and the production of ECM components.Methods: Primary cultures of human gingival fibroblasts (HGFs) were stimulated with recombinant TGF‐β1 and TNF‐α. Protein levels of α‐smooth muscle actin (α‐SMA), type I collagen, heat shock protein‐47 (HSP‐47), fibronectin (FN), ED‐A‐FN, and periostin and activation of the Smad pathway were evaluated through Western blot analysis. α‐SMA and actin fibers were identified by immunofluorescence. TGF‐β1, TNF‐α, and α‐SMA were identified by immunohistochemistry in biopsies of inflamed human gingival tissues. TGF‐β1 activity was evaluated using a plasminogen activator inhibitor‐1 (PAI‐1) reporter transfected in HGFs.Results: TGF‐β1 stimulated the differentiation of myofibroblasts as evidenced by strong expression of α‐SMA and ED‐A‐FN. Moreover, TGF‐β1 induced the production of type I collagen, HSP‐47, FN, and periostin. Costimulation with TNF‐α and TGF‐β1 significantly reduced the expression of all the above‐mentioned proteins. TNF‐α also inhibited the activation of the Smad2/3 pathway and the activity of the PAI‐1 reporter.Conclusions: TNF‐α inhibits several cell responses induced by TGF‐β1, including the differentiation of myofibroblasts, the activation of the Smad signaling pathway, and the production of key molecules involved in tissue repair, such as type I collagen, FN, and periostin. The interaction between cytokines may explain the delayed tissue repair observed in chronic inflammation of gingival tissues.
e-Cigarette Awareness, Use, and Harm Perceptions in US Adults
Authors: Pearson Jennifer L. , Richardson Amanda , Niaura Raymond S. , Vallone Donna M. , Abrams David B. 
Published: July 2012

Objectives. We estimated e-cigarette (electronic nicotine delivery system) awareness, use, and harm perceptions among US adults. Methods. We drew data from 2 surveys conducted in 2010: a national online study (n = 2649) and the Legacy Longitudinal Smoker Cohort (n = 3658). We used multivariable models to examine e-cigarette awareness, use, and harm perceptions. Results. In the online survey, 40.2% (95% confidence interval [CI] = 37.3, 43.1) had heard of e-cigarettes, with awareness highest among current smokers. Utilization was higher among current smokers (11.4%; 95% CI = 9.3, 14.0) than in the total population (3.4%; 95% CI = 2.6, 4.2), with 2.0% (95% CI = 1.0, 3.8) of former smokers and 0.8% (95% CI = 0.35, 1.7) of never-smokers ever using e-cigarettes. In both surveys, non-Hispanic Whites, current smokers, young adults, and those with at least a high-school diploma were most likely to perceive e-cigarettes as less harmful than regular cigarettes. Conclusions. Awareness of e-cigarettes is high, and use among current and former smokers is evident. We recommend product regulation and careful surveillance to monitor public health impact and emerging utilization patterns, and to ascertain why, how, and under what conditions e-cigarettes are being used.
Identifying the Core Elements of Effective Community Health Worker Programs: A Research Agenda
Authors: Arvey Sarah R. , Fernandez Maria E. 
Published: July 2012

Community health workers (CHWs) are increasingly being incorporated into health programs because they are assumed to effectively deliver health messages in a culturally relevant manner to disenfranchised communities.Nevertheless, the role of CHWs—who they are, what they do, and how they do it—is tremendously varied. This variability presents a number of challenges for conducting research to determine the effectiveness of CHW programs, and translating research into practice.We discuss some of these challenges and provide examples from our experience working with CHWs. We call for future research to identify the “core elements” of effective CHW programs that improve the health and well-being of disenfranchised communities.
Reducing Childhood Obesity by Eliminating 100% Fruit Juice
Authors: Wojcicki Janet M. , Heyman Melvin B. 
Published: July 2012

The Healthy Hunger-Free Kids Act of 2010 presents an opportunity to change the nutritional quality of foods served in low-income childcare centers, including Head Start centers. Excessive fruit juice consumption is associated with increased risk for obesity. Moreover, there is recent scientific evidence that sucrose consumption without the corresponding fiber, as is commonly present in fruit juice, is associated with the metabolic syndrome, liver injury, and obesity. Given the increasing risk of obesity among preschool children, we recommend that the US Department of Agriculture’s Child and Adult Food Care Program, which manages the meal patterns in childcare centers such as Head Start, promote the elimination of fruit juice in favor of whole fruit for children.
Troponin T for the Detection of Dialysis-Induced Myocardial Stunning in Hemodialysis Patients
Authors: Breidthardt Tobias , Burton James O. , Odudu Aghogho , Eldehni Mohamed Tarek , Jefferies Helen J. , McIntyre Christopher W. 
Published: July 2012

Summary

Background and objectives
Circulating troponin T levels are frequently elevated in patients undergoing long-term dialysis. The pathophysiology underlying these elevations is controversial.

Design, setting, participants, & measurements
In 70 prevalent hemodialysis (HD) patients, HD-induced myocardial stunning was assessed echocardiographically at baseline and after 12 months. Nineteen patients were not available for the follow-up analysis. The extent to which predialysis troponin T was associated with the occurrence of HD-induced myocardial stunning was assessed as the primary endpoint.

Results
The median troponin T level in this hemodialysis cohort was 0.06 ng/ml (interquartile range, 0.02–0.10). At baseline, 64% of patients experienced myocardial stunning. These patients showed significantly higher troponin T levels than patients without stunning (0.08 ng/ml [0.05–0.12] versus 0.02 ng/ml [0.01–0.05]). Troponin T levels were significantly correlated to measures of myocardial stunning severity (number of affected segments: r=0.42; change in ejection fraction from beginning of dialysis to end of dialysis: r=−0.45). In receiver-operating characteristic analyses, predialytic troponin T achieved an area under the curve of 0.82 for the detection of myocardial stunning. In multivariable analysis, only ultrafiltration volume (odds ratio, 4.38 for every additional liter) and troponin T (odds ratio, 9.33 for every additional 0.1 ng/ml) were independently associated with myocardial stunning. After 12 months, nine patients had newly developed myocardial stunning and showed a significant increase in troponin T over baseline (0.03 ng/ml at baseline versus 0.05 ng/ml at year 1).

Conclusions
Troponin T levels in HD patients are associated with the presence and severity of HD-induced myocardial stunning.
Hemodialysis-Induced Regional Left Ventricular Systolic Dysfunction
Authors: Assa Solmaz , Hummel Yoran M. , Voors Adriaan A. , Kuipers Johanna , Westerhuis Ralf , de Jong Paul E. , Franssen Casper F.M. 
Published: July 2012

Summary

Background and objectives
The hemodialysis procedure may acutely induce regional left ventricular systolic dysfunction. This study evaluated the prevalence, time course, and associated patient- and dialysis-related factors of this entity and its association with outcome.

Design, setting, participants, & measurements
Hemodialysis patients (105) on a three times per week dialysis schedule were studied between March of 2009 and March of 2010. Echocardiography was performed before dialysis, at 60 and 180 minutes intradialysis, and at 30 minutes postdialysis. Hemodialysis-induced regional left ventricular systolic dysfunction was defined as an increase in wall motion score in more than or equal to two segments.

Results
Hemodialysis-induced regional left ventricular systolic dysfunction occurred in 29 (27%) patients; 17 patients developed regional left ventricular systolic dysfunction 60 minutes after onset of dialysis. Patients with hemodialysis-induced left ventricular systolic dysfunction were more often male, had higher left ventricular mass index, and had worse predialysis left ventricular systolic function (left ventricular ejection fraction). The course of blood volume, BP, heart rate, electrolytes, and acid–base parameters during dialysis did not differ significantly between the two groups. Patients with hemodialysis-induced regional left ventricular systolic dysfunction had a significantly higher mortality after correction for age, sex, dialysis vintage, diabetes, cardiovascular history, ultrafiltration volume, left ventricular mass index, and predialysis wall motion score index.

Conclusions
Hemodialysis induces regional wall motion abnormalities in a significant proportion of patients, and these changes are independently associated with increased mortality. Hemodialysis-induced regional left ventricular systolic dysfunction occurs early during hemodialysis and is not related to changes in blood volume, electrolytes, and acid–base parameters.
A Randomized Trial Comparing Buttonhole with Rope Ladder Needling in Conventional Hemodialysis Patients
Authors: MacRae Jennifer M. , Ahmed Sofia B. , Atkar Rajneet , Hemmelgarn Brenda R. 
Published: July 2012

Summary

Background and objectives
Buttonhole needling is reported to be associated with less pain than standard needling. The purpose of this study was to compare patient perceived pain and fistula complications in buttonhole and standard needling.

Design, setting, participants, & measurements
In this study, 140 conventional hemodialysis patients were randomly assigned to buttonhole or standard needling. The primary outcome was patient perceived pain with needling at 8 weeks. Fistula complications of hematoma, bleeding postdialysis, and infection were tracked.

Results
Median pain score at 8 weeks using a visual analog scale from 0 to 10 cm was similar for standard and buttonhole needling (1.2 [0.4–2.4] versus 1.5 [0.5–3.4]; P=0.57). Rate of hematoma formation in standard needling was higher (436 versus 295 of 1000 hemodialysis sessions; P=0.03). Rate of no bleeding postdialysis was 23.6 and 28.3 per 1000 in standard and buttonhole needling, respectively (P=0.40). Rate of localized signs of infection in standard versus buttonhole needling was 22.4 versus 50 per 1000 (P=0.003). There was one episode of Staphylococcal aureus bacteremia during the 8 weeks with buttonhole needling and no episodes with standard needling (P=1.00). Within 12 months of follow-up, another two buttonhole needling episodes developed S. aureus bacteremia, and nine buttonhole needling episodes had needling site abscesses requiring intravenous antibiotics versus zero standard needling episodes (P=0.003).

Conclusions
Patients had no difference in pain between buttonhole and standard needling. Although fewer buttonhole needling patients developed a hematoma, there was an increased risk of bacteremia and localized signs of infection. Routine use of buttonhole needling is associated with increased infection risk.
IgA Anti-transglutaminase Autoantibodies at Type 1 Diabetes Onset Are Less Frequent in Adult Patients and Are Associated With a General Celiac-Specific Lower Immune Response in Comparison With Nondiabetic Celiac Patients at Diagnosis
Authors: Tiberti Claudio , Panimolle Francesca , Bonamico Margherita , Shashaj Blegina , Filardi Tiziana , Lucantoni Federica , Nenna Raffaella , Costantino Francesco , Lenzi Andrea , Morano Susanna 
Published: July 2012

OBJECTIVE
To evaluate the celiac-associated humoral autoimmunity in child, adolescent, and adult patients at type 1 diabetes (DM1) onset and to determine whether DM1 celiac-specific humoral immunoreactivity occurs similarly to that in nondiabetic patients at celiac disease (CD) diagnosis.

RESEARCH DESIGN AND METHODS
IgA anti-transglutaminase autoantibody (IgA-tTGAb) was detected in 654 new-onset DM1 sera. IgA-tTGAb+ DM1 sera were subsequently analyzed for IgG-tTG, deamidated gliadin (DGP), and actin antibodies, and results were compared with those found in 83 screen-detected nondiabetic patients at CD diagnosis.

RESULTS
A total of 12.8% DM1 sera were IgA-tTGAb+, with a lower autoantibody frequency in adult patients aged &gt;18 years (6.8 vs. 15.1%, aged ≤18 years; P = 0.005). IgA-tTGAb titers, IgG-tTGAb, and DGPAb frequency/titers and mean number of celiac-autoantibody positivities per patient were significantly lower in IgA-tTGAb+ DM1 compared with nondiabetic CD patients.

CONCLUSIONS
Age of diabetes onset is negatively associated with risk of CD. The celiac-specific humoral immunoreactivity at DM1 onset is significantly lower compared with that found in nondiabetic patients at CD diagnosis.
Growth-Differentiation Factor 15 Predicts Worsening of Albuminuria in Patients With Type 2 Diabetes
Authors: Hellemons Merel E. , Mazagova Magdalena , Gansevoort Ron T. , Henning Robert H. , de Zeeuw Dick , Bakker Stephan J.L. , Lambers-Heerspink Hiddo J. , Deelman Leo E. 
Published: July 2012

OBJECTIVEDevelopment of micro- or macroalbuminuria is associated with increased risk of cardiorenal complications, particularly in diabetes. For prevention of transition to micro- or macroalbuminuria, more accurate prediction markers on top of classical risk markers are needed. We studied a promising new marker, growth-differentiation factor (GDF)-15, to predict transition to increasing stage of albuminuria in type 2 diabetes mellitus (T2DM). In addition, we looked at the GDF-15 potential in nondiabetic subjects with hypertension (HT).RESEARCH DESIGN AND METHODSCase and control subjects were selected from the PREVEND cohort, a large (n = 8,592), prospective general population study on the natural course of albuminuria, with &gt;10 years of follow-up and repeated albuminuria measurements. We found 24 T2DM and 50 HT case subjects transitioning from normo- to macroalbuminuria and 9 T2DM and 25 HT case subjects transitioning from micro- to macroalbuminuria (average follow-up 2.8 years). Control subjects with stable albuminuria were pair matched for age, sex, albuminuria status, and diabetes duration. GDF-15 was measured in samples prior to albuminuria transition.RESULTSPrior to transition, GDF-15 was significantly higher in case subjects with T2DM than in control subjects (median [IQR] 1,288 pg/mL [885–1,546] vs. 948 pg/mL [660–1,016], P &lt; 0.001). The odds ratio for transition in albuminuria increased significantly per SD of GDF-15 (2.9 [95% CI 1.1–7.5], P = 0.03). GDF-15 also improved prediction of albuminuria transition, with significant increases in C statistic (from 0.87 to 0.92, P = 0.03) and integrated discrimination improvement (0.148, P = 0.001). In HT, GDF-15 was also independently associated with transition in albuminuria stage (2.0 [1.1–3.5], P = 0.02) and improved prediction significantly.CONCLUSIONSWe identified GDF-15 as a clinically valuable marker for predicting transition in albuminuria stage in T2DM beyond conventional risk markers. These findings were confirmed in nondiabetic HT subjects.
Effect of selenium in organic and inorganic form on liver, kidney, brain and muscle of Wistar rats
Authors: Sochor Jiri , Pohanka Miroslav , Ruttkay-Nedecky Branislav , Zitka Ondrej , Hynek David , Mares Petr , Zeman Ladislav , Adam Vojtech , Kizek Rene 
Published: July 2012

Abstract
Selenium is a micronutrient, localized in the active sites of enzymes such as glutathione peroxidase and thioredoxin reductase, and participating together with these enzymes in an antioxidant defence system of organisms against free radicals. Administration of selenium is necessary for maintaining oxidative homeostasis. The present experiment is aimed at investigation of selenium impact on basal metabolic processes and selected antioxidants in a Wistar rat model, fed selenium in organic and inorganic forms. Liver, kidney, brain and muscle were sampled during a month-long feeding with four different doses of selenium (0.075 mg or 1.5 mg of inorganic and/or organic selenium per kg of feed). We found a significant reduction in glutathione level in liver tissue regardless of the form of the administered selenium. On the other hand, selenium caused a decreased glutathione reductase level in the liver and metallothionein level in the liver, kidney and muscle.
The effects on soil/water/plant/animal systems by platinum group elements
Authors: Sobrova Pavlina , Zehnalek Josef , Adam Vojtech , Beklova Miroslava , Kizek Rene 
Published: July 2012

Abstract
Emissions of toxic substances such as oxides of carbon, nitrogen, sulphur, and, in addition, aromatic hydrocarbons, aldehydes and heavy metals are the most serious problem of road traffic affecting landscape. Platinum group elements (PGE), which are the main component of the catalyst, are one of the main sources of heavy metals in the environment. Here, we review the way by which emissions and forms of the emitted PGE end up in the environment especially to the soil-water-plant-animal system. The major points discussed are the following: 1) the main sources of PGE emission are automobile exhaust catalysts; 2) hospitals, where platinum is widely used to treat malignant neoplasm, and urban waste water belonging to other important sources of PGE in the environment; 3) soil is one of the most important components of the environment that may be contaminated with platinum metals; 4) phytotoxicity of PGE depends on the following conditions: the concentration of metals in the soil, time of exposure, the chemical form of metal, the chemical composition of exposed soil and plant species; 5) animals are also endangered by the increasing concentration of PGE in the environment. Moreover, we pay our attention to thiol-based mechanisms of how an organism protects itself against platinum group elements.
Corrosion resistance of stainless steel covered by 4-aminobenzoic acid films
Authors: Adamczyk Lidia , Pietrusiak Anna , Bala Henryk 
Published: July 2012

Abstract
The protective, anticorrosion properties of 4-aminobenzoic acid (4-ABA) films are evaluated in the paper. The 4-ABA films were electrodeposited on the surface of both X20Cr13 stainless steel and glassy carbon electrodes by galvanostatically and cyclic voltammetry methods. The protective properties of the resulting films on stainless steel were investigated in the aggressive medium of acidified (pH=4) 0.25 mol dm−3 K2SO4 in the absence and with the presence of 0.5 mol dm−3 KCl. Morphology of the 4-ABA films was examined using scanning electron microscopy.