bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in weight and dimensions in the drying and carbonation of Portland cement mortars
Authors: Kamimura K. , Sereda P. J. , Swenson E. G. 
Published: July 2012

Summary Small specimens of mortar and paste were cured for 28 days and then subjected to various conditions of drying and carbonation. In general the extent of carbonation, for a given CO2 concentration, depends upon permeability, moisture content and time, but the extent of carbonation shrinkage and ultimate volume stability depend on the compressibility of the aggregate, the water/cement ratio, the maturity of the paste, the drying environment and rate, and on the sequence of drying and carbonation. Some of the practical implications of these results are noted.
The effect of various sulphate solutions on the strength and other properties of cement mortars at temperatures up to 80°C
Authors: Richards John D. 
Published: July 2012

Summary The results indicate that small rises in temperature can reduce and often prevent deterioration of Portland cement mortars in sulphate media, although rises in temperature cause loss of strength in other cements due to changes in crystal structure. The resistance of mortars to the more aggressive magnesium and ammonium sulphates at higher temperatures and the small expansion which occurs above 40°C are conclusively demonstrated.
Tests on end-zone stresses in pre-tensioned concrete I beams
Authors: Arthur P. D. , Ganguli S. 
Published: July 2012

Summary A series of tests to measure the strains in the endzones of pre-tensioned prestressed concrete I beams is described. The variables were limited to the web breadth and the arrangement of prestressing wires. The maximum stress on the end face of a beam when horizontal cracking occurred was found to bear a linear relationship to the cube strength of the concrete at transfer. The strain at cracking was virtually constant. Peak tensile stresses on the end faces as predicted by various methods are compared with stresses obtained from measured strains, and suggestions are made for approximate predictions of stresses. A procedure is proposed for determining whether cracking is likely.
Tricalcium aluminate and related phases in Portland cement
Authors: Moore A. E. 
Published: July 2012

Summary The paper reports an X-ray diffraction study of the effect of impurities on the structure of tricaldum aluminate. A number of workers have shown that Fe2O3 can replace some of the Al2O3 in C3A, and that this is accompanied by an increase in cell size. Estimates of the limiting composition vary from 2 to 10 molar % C3F/(C3F + C3A); the reasons for these differences are discussed. It is shown that silica and magnesia can also enter the C3A lattice and both cause a decrease in the unit cell size. In all the preceding cases the C3A remains cubic; this is also true for additions of Na2O up to about 3 molar %; with higher concentrations the structure becomes orthorhombic. Some measurements of cell size of C3A extracted from Portland cement are also given. In the light of these findings, a structure is postulated for C3A which differs in important respects from the currently accepted one, of Büssem and Eitel.
Redistribution of moments in prestressed concrete continuous beams
Authors: Mallick S. K. , Sastry M. K. L. N. 
Published: July 2012

Summary Twenty-seven three-span and twelve two-span beams, all of rectangular cross-section, were tested to destruction under various arrangements of concentrated loads. The results of these tests are presented. Redistribution of moments was practically complete in the majority of the beams. The curvature distributions along the plastic lengths have been studied and the rotations deduced therefrom are compared with those obtained on the basis of the standard moment-curvature relationship proposed by Guyon.
Some fatigue tests of high-strength concrete in axial compression
Authors: Bennett E. W. , Muir S. E. St J. 
Published: July 2012

Summary A programme of tests was undertaken of concrete prisms in axial compression to study the influence of the static strength and the maximum size of coarse aggregate upon the fatigue strength at one million cycles. Four types of concrete were tested having average static strengths of about 6,000 and 8,500 lb/in2, each made with aggregate of ¾ and ⅜ in. maximum size. The fatigue strength varied between 66 and 71 % of the static strength and, although the percentage values were significantly lower with the higher-strength concrete and with the ⅜ in. aggregate, the actual magnitude of the differences was small. The general strain history was typical of previous fatigue tests, and the ‘run-out’ specimens showed a marked increase in static strength over similar specimens that had not been loaded.
Creep of concrete under uniaxial and biaxial stresses at elevated temperatures
Authors: Arthanari S. , Yu C. W. 
Published: July 2012

Summary This paper deals briefly with the need for data on creep and shrinkage of concrete at elevated temperatures. Tests designed to determine the Poisson's effect under combined stresses on heated concrete are described and it is shown that an effective Poisson's ratio of 0·2 can be assumed for design purposes. General conclusions regarding creep at elevated temperatures have been drawn from tests on sealed and unsealed slab specimens at elevated temperatures.
The Impact of Oral Health on the Academic Performance of Disadvantaged Children
Authors: Seirawan Hazem , Faust Sharon , Mulligan Roseann 
Published: July 2012

Objectives. We measured the impact of dental diseases on the academic performance of disadvantaged children by sociodemographic characteristics and access to care determinants Methods. We performed clinical dental examinations on 1495 disadvantaged elementary and high school students from Los Angeles County public schools. We matched data with academic achievement and attendance data provided by the school district and linked these to the child’s social determinants of oral health and the impact of oral health on the child’s school and the parents’ school or work absences. Results. Students with toothaches were almost 4 times more likely to have a low grade point average. About 11% of students with inaccessible needed dental care missed school compared with 4% of those with access. Per 100 elementary and high school–aged children, 58 and 80 school hours, respectively, are missed annually. Parents averaged 2.5 absent days from work or school per year because of their children’s dental problems. Conclusions. Oral health affects students’ academic performance. Studies are needed that unbundle the clinical, socioeconomic, and cultural challenges associated with this epidemic of dental disease in children.
Evidence in Oral Health Promotion—Implications for Oral Health Planning
Authors: Singh Shenuka 
Published: July 2012

I have explored the debates on evidence-based oral health promotion and examined the practicality of promoting oral health care within a whole system (social, cultural, and environmental) approach. The use of evidence-based decision-making in health services and planning is a viable mechanism to identify optimal health benefits; however, barriers to the effective adoption of evidence-based health practice, including barriers that apply to oral health promotion, have been identified. Evidence-based oral health promotion highlights the importance of examining health promotion activities within a defined social context—a departure from the focus on improving study designs and research methods. Thus, the basis for evidence in health activities is grounded in social and organizational systems. This could contribute to sustainable health efforts.
Engaging Individuals Recently Released From Prison Into Primary Care: A Randomized Trial
Authors: Wang Emily A. , Hong Clemens S. , Shavit Shira , Sanders Ronald , Kessell Eric , Kushel Margot B. 
Published: July 2012

Objectives. Individuals released from prison have high rates of chronic conditions but minimal engagement in primary care. We compared 2 interventions designed to improve primary care engagement and reduce acute care utilization: Transitions Clinic, a primary care–based care management program with a community health worker, versus expedited primary care. Methods. We performed a randomized controlled trial from 2007 to 2009 among 200 recently released prisoners who had a chronic medical condition or were older than 50 years. We abstracted 12-month outcomes from an electronic repository available from the safety-net health care system. Main outcomes were (1) primary care utilization (2 or more visits to the assigned primary care clinic) and (2) emergency department (ED) utilization (the proportion of participants making any ED visit). Results. Both groups had similar rates of primary care utilization (37.7% vs 47.1%; P = .18). Transitions Clinic participants had lower rates of ED utilization (25.5% vs 39.2%; P = .04). Conclusions. Chronically ill patients leaving prison will engage in primary care if provided early access. The addition of a primary care–based care management program tailored for returning prisoners reduces ED utilization over expedited primary care.
Prescription Patterns and Mineral Metabolism Abnormalities in the Cinacalcet Era
Authors: Fukagawa Masafumi , Fukuma Shingo , Onishi Yoshihiro , Yamaguchi Takuhiro , Hasegawa Takeshi , Akizawa Tadao , Kurokawa Kiyoshi , Fukuhara Shunichi 
Published: July 2012

Summary

Background and objectives
Prescription patterns for hemodialysis patients with secondary hyperparathyroidism have varied widely since market introduction of cinacalcet. This study examined associations between prescription patterns and subsequent laboratory values.

Design, setting, participants, & measurements
Using a Mineral and Bone Disorder Outcomes Study for Japanese CKD Stage 5D Patients subcohort, 1716 prevalent hemodialysis patients (4048 sets for repeated measures between January 2008 and July 2009) with an intact parathyroid hormone (iPTH) level >180 pg/ml who used intravenous vitamin D receptor activator (VDRA) without cinacalcet were selected. Prescription patterns were defined based on cinacalcet administration (starting or not) and VDRA dosage change (decreased [<−25%], stable [−25% to 25%], or increased [>25%]). Proportion differences (PDs) were determined for decreasing iPTH levels by at least one category (<180, 180–299, 300–499, and ≥500 pg/ml) and for achieving target phosphorus (3.5–6.0 mg/dl) and calcium (8.4–10.0 mg/dl) levels, adjusting for potential confounders.

Results
The starting cinacalcet and increased VDRA patterns were associated with decreasing iPTH levels (PD, 0.25 and 0.13; 95% confidence intervals [95% CIs], 0.19–0.31 and 0.09–0.17, respectively); combination use had an additive association (PD, 0.34; 95% CI, 0.20–0.42). The starting cinacalcet and decreased VDRA combination was associated with simultaneously achieving target phosphorus (PD, 0.12; 95% CI: 0.04–0.20) and calcium (PD, 0.09; 95% CI, 0.01–0.17) levels.

Conclusions
Certain combinations of cinacalcet and VDRA were associated with decreasing iPTH and achieving targets for phosphorus and calcium. Combinations may prove advantageous versus VDRA alone in managing secondary hyperparathyroidism.
Continuing Disparities in Cardiovascular Risk Factors and Complications Between Aboriginal and Anglo-Celt Australians With Type 2 Diabetes
Authors: Davis Timothy M.E. , Hunt Kerry , McAullay Daniel , Chubb Stephen A.P. , Sillars Brett A. , Bruce David G. , Davis Wendy A. 
Published: July 2012

OBJECTIVE
To determine whether disparities in the nature and management of type 2 diabetes persist between Aboriginal and the majority Anglo-Celt patients in an urban Australian community.

RESEARCH DESIGN AND METHODS
Baseline data from the observational Fremantle Diabetes Study collected from 1993 to 1996 (phase I) and from 2008 to 2011 (phase II) were analyzed. Patients characterized as Aboriginal or Anglo-Celt by self-report and supporting data underwent comprehensive assessment, including questionnaires, examination, and biochemical testing in a single laboratory. Generalized linear modeling with age/sex adjustment was used to examine differences in changes in variables in the two groups between phases I and II.

RESULTS
The indigenous participants were younger at entry and at diabetes diagnosis than the Anglo-Celt participants in both phases. They were also less likely to be educated beyond primary level and were more likely to be smokers. HbA1c decreased in both groups over time (Aboriginal median 9.6% [interquartile range 7.8–10.7%] to 8.4% [6.6–10.6%] vs. Anglo-Celt median 7.1% [6.2–8.4%] to 6.7% [6.2–7.5%]), but the gap persisted (P = 0.65 for difference between phases I and II by ethnic group). Aboriginal patients were more likely to have microvascular disease in both phases. The prevalence of peripheral arterial disease (ankle-brachial index ≤0.90 or lower-extremity amputation) increased in Aboriginal but decreased in Anglo-Celt participants (15.8–29.7 vs. 30.7–21.5%; P = 0.055).

CONCLUSIONS
Diabetes management has improved for Aboriginal and Anglo-Celt Australian patients, but disparities in cardiovascular risk factors and complications persist.
Complexation of some univalent organic cations with benzo-18-crown-6 in nitrobenzene saturated with water
Authors: Makrlík Emanuel , Vaňura Petr , Selucký Pavel 
Published: July 2012

Abstract
From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium C+(aq) + 1·Na+(nb) 1·C+ (nb) + Na+(aq) taking place in the two-phase water-nitrobenzene system (C+ = methylammonium, ethylammonium, propylammonium, ethanolammonium, diethanolammonium, triethanolammonium, cation TRIS+, hydrazinium, hydroxylammonium; 1 = benzo-18-crown-6; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the 1·C+ cationic complex species in nitrobenzene saturated with water were calculated; they were found to increase in the following cation order: triethanolammonium +
A direct method for the decontamination of a fly ash amended wet soil, artificially polluted with dioxins
Authors: Simion Alina , Kakeda Mitsunori , Egashira Naoyoshi , Mitoma Yoshiharu , Simion Cristian 
Published: July 2012

Abstract
We report hereby the first method of direct treatment of a wet soil containing toxic polychloroderivatives. Using a system with metallic Ca and 5% Rh fixed on charcoal in methanol, soil samples artificially polluted with fly ash containing polychloro-dibenzodioxins (PCDDs), polychloro-dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (co-PCBs), and having 69.2% to 84.6% moisture content, were successfully treated and decontaminated. This treatment afforded excellent hydrodechlorination yields for the 29 most toxic congeners of PCDDs, PCDFs and PCBs (98.3% degradation yield based on toxic equivalent quotient — or TEQ) after a 24 h treatment, at room temperature.
Synthesis, characterization and adsorption properties of nanostructured hybrid materials modified by boron and zirconium
Authors: Georgieva Ralitsa , Vassileva Paunka , Detcheva Albena , Voykova Dimitrinka , Gerganova Tsvetelina , Ivanova Yordanka 
Published: July 2012

Abstract
The adsorption properties of two new nanostructured hybrid materials containing B2O3 and ZrO2 were studied. The new organic-inorganic materials were synthesized via a sol-gel method. As a modifying agent, a quantity of 10 wt.% Zr(OPr)4 or B(OCH3)3 was added. The structure of the hybrid materials was investigated by means of (Fourier transform infrared spectroscopy (FTIR), x-ray diffractometry (XRD), scanning electron microscopy (SEM), (atomic force microscopy (AFM) and nuclear magnetic resonance spectroscopy (NMR). Based on the obtained data, the most probable cross-linking mechanism for the derived gels was proposed. The characterization of texture parameters of both materials was carried out with the use of low-temperature adsorption of nitrogen. Adsorption of Cu(II), Fe(III), Cr(III), Cd(II) and Pb(II) ions on both materials was investigated using multi-component solutions with different concentrations and acidity by means of the batch method. Kinetics of adsorption was also investigated. Pseudo-first order, pseudo-second order and intraparticle diffusion models were used to analyze kinetic data. The adsorption was significantly affected by the pH value. Equilibrium data were fitted to linear Langmuir, Freundlich and Dubinin-Radushkevich models and maximum adsorption capacities were calculated.
Conformational isomerism of 1-butene secondary ozonide as studied by means of matrix isolation infrared absorption spectroscopy
Authors: Strazdaite Simona , Bariseviciute Ruta , Ceponkus Justinas , Sablinskas Valdas 
Published: July 2012

Abstract
Theoretical calculations of structures, stability and vibrational spectra of 1-butene secondary ozonide (SOZ) conformers were performed using DFT method B3LYP with a 6-311++G(3df, 3pd) basis set. The calculations predict six staggered structures of 1-butene SOZ. The FTIR spectra of 1-butene SOZ isolated in Ar, N2 and Xe matrices were recorded. It was found that nitrogen is the best suited for the matrix isolation of 1-butene SOZ. The bandwidth of the spectral bands of the ozonide isolated in nitrogen was as narrow as 2 cm−1. For the first time the existence of five conformers of 1-butene SOZ were confirmed experimentally by means of matrix isolation infrared absorption spectroscopy. The equatorial gauche (∠OCCC=−66.1°) conformer was proved theoretically and experimentally to be the most stable. It was found that due to high potential barriers of the conformational transitions annealing of the matrix is useless for the assignment of spectral bands to various conformers of 1-butene SOZ. Using the hot nozzle technique the van’t Hoff experimental plots were made for three additional conformers of 1-butene SOZ and experimental ΔH values for these additional conformers were established. The crystallization problems of 1-butene SOZ are discussed which accounts for the rich conformational diversity of the ozonide as well as high conformational barriers for axial-equatorial transitions.
Synthesis of fluorescent carboxylic acid ligands for construction of monolayers on nanostructures
Authors: Jadhav Sushilkumar 
Published: July 2012

Abstract
Two new long-chain carboxylic acids (1, 2) bearing strong fluorescent group pyrene as ligands for Self-Assembled Monolayers (SAMs) have been synthesized. The multistep targeted synthesis is accomplished by use of Pyren-1-yl methylamine hydrochloride and employing simplified synthetic protocols. Compound 2 contains a chiral center purposely introduced along the atom chain in order to make it suitable for chiro-optical studies of the resulting SAMs.
Synthesis and acid solution properties of a novel betaine zwitterionic surfactant
Authors: Quan Hongping , Zhang Xuan , Lu Hongsheng , Huang Zhiyu 
Published: July 2012

Abstract
An effective and economic route was developed to synthesize a novel betaine zwitterionic surfactant gondoyl dimethyl amidopropyl betaine (GDAB) directly from natural fatty acid gondoic acid. The optimal processing conditions for synthesizing the intermediate and final product were probed: N,N-dimethyl-N′-gondoyl-1,3-propylenediamine was synthesized by the reaction of gondoic acid with N,N-dimethyl-1,3-propylenediamine at 160°C for 6 h, then the intermediate was reacted with sodium chloroacetate in methanol-water system (methanol/water:20% at 60°C and the product was obtained after 6h. The compounds were confirmed by IR and 1HNMR. The properties of GDAB acid solution were investigated and the results indicated that viscosity of acid solution increased with decreasing hydrochloric acid concentration and was mainly controlled by surfactant concentration and temperature. The viscosity of acid solution reached the maximum value when the concentration of hydrochloric acid was 2.28 mo L−1.
Isocratic liquid chromatographic determination of three paraben preservatives in hygiene wipes using a reversed phase core-shell narrow-bore column
Authors: Tzanavaras Paraskevas , Karakosta Theano , Rigas Pantelis , Themelis Demetrius , Zotou Anastasia 
Published: July 2012

Abstract
The first HPLC method for the separation of three paraben preservatives (methyl-, ethyl- and propyl parabens) using a core-shell analytical column is reported in this study. The separation was completed in less than 8 min at a low flow rate of 0.4 mL min−1 and an isocratic mobile phase containing 20% acetonitrile as organic modifier. The backpressure was HPLC equipment. The proposed analytical procedure was validated for linearity (0.5–20 µg L−1), limits of detection (15–43 µg L−1) and quantification (50–142 µg L−1), selectivity, within day (1.3–1.5%) and day-to-day (3.4–4.6%) precision and accuracy. The proposed method has been applied to the determination of the selected paraben preservatives in commercially available hygiene wipes. The mean percent recoveries were found to be in the range of 98.0–98.4%.
Voltammetric determination of Rutin at Screen-Printed carbon disposable electrodes
Authors: Oliveira-Roberth Aline , Santos Diego , Cordeiro Diogo , Lino Fernando , Bara Maria , Gil Eric 
Published: July 2012

Abstract
Rutin is a flavonoid commonly employed for many therapeutic purposes. Although the electroactive phenolic groups of rutin might be oxidized at low applied potential, the adsorption of oxidized species changes the electrode surface. As a consequence, the repeatability and reproducibility of the method decreases, which limits electroanalytical applications. This paper describes the use of disposable screen-printed electrodes as an alternative to improve the electrochemical quantification of rutin in commercial and standard samples. The electrochemical behavior was consistent to what is observed using other carbon electrodes: an adsorption-involved step and a pH-dependent oxidation process. The replacement of the electrodes between the analyses ensured rapid analysis, good intermediate precision and repeatability. The proposed method was successfully applied to rutin determination in pharmaceutical samples of capsules, with the limit of quantification being 0.30 µM.
Selected risk factors of fractures in children — own observation
Authors: Jakubowska-Pietkiewicz Elżbieta , Fendler Wojciech , Młynarski Wojciech , Klich Izabela , Chlebna-Sokół Danuta 
Published: July 2012

Abstract
Bone fractures may depend on Vitamin D Receptor Gene (VDR), bone mineral density, bone turnover markers. Patients and methods. 161 patients were recruited and underwent: skeletal densitometry (DXA) method and bone turnover studies (Osteocalcin and Ntx).The study group was evaluated using restriction enzyme digestion at BsmI (rs1544410), FokI (rs2228570), ApaI (rs7975232) and TaqI (rs731236), polymorphic sites of the VDR gene. Multivariate logistic regression was used to assess factor significance. The model included variables with sex- and age-standardized parameters, VDR genotypes, and bone metabolism marker levels. Results. Factors associated with fractures were: osteocalcin concentration and Z-score BMDt. Odds Ratio (OR) values equaled: 1.01 (95%Confidence Interval (95%CI) 1.00–1.02) for osteocalcin (p=0.006), and 0.66 (95%CI 0.42-1.03; p=0.07) for Z-score BMDt. In patients with reduced bone mass, factors related to fractures were: osteocalcin (0.04) and carriage of BsmI b (0.07) or ApaI a alleles (0.08). ORs were 1.01 (95%CI 1.00–1.02) for OC, 0.29 (95%CI 0.07–1.14) for BsmI, and 2.13 (95%CI 0.91–4.99) for ApaI polymorphic allele carriage. Conclusions. Carriage of BsmI b allele reduces, while carriage of ApaI a allele and heightened osteoclacin level increase the risk of fractures in study children with reduced bone mass. VDR polymorphism, bone mineral density and bone formation’s marker — osteocalcin maybe considered as risk factor for fracure in children from Lodz region.