bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro T2 relaxivities of the Gd-based contrast agents (GBCAs) in human blood at 1.5 and 3 T
Authors: Shen Yaqi , Goerner Frank L , Heverhagen Johannes T , Snyder Christopher , Hu Daoyu , Li Xiaoming , Runge Val M 
Published: September 2018

Background The availability of data in the medical literature for the T2 relaxivities of the Gd-based contrast agents (GBCAs) is limited. A comprehensive comparison between the agents available commercially (other than in Europe) is lacking, with no data available that most closely reflect the clinic, which is in human whole blood at body temperature. Purpose To complement the existing literature by determining T2 relaxivity data for eight GBCAs in vitro. Material and Methods The relaxivities of eight GBCAs diluted in human whole blood at 1.5 and 3 T were determined at 37 ± 0.5 °C. Gd was in the range of 0–4 mM. Multi-echo sequences with variable echo times were acquired using a phantom containing a dilution series with each agent, and SigmaPlot 12.0 was used to calculate the R2 relaxation rate and finally r2. Statistical comparisons between agents and field strengths were conducted. Results The relationship between R2 vs. Gd was observed to be linear at 1.5 and 3 T, with a mild increase in r2 from 1.5 to 3 T for all GBCAs. T2 relaxivity data were compared with prior results. The GBCAs are closely clustered into two groups, with higher r2 noted for the two lipophilic (those with partial hepatobiliary excretion) compounds. Conclusion The r2 values at 1.5 and 3 T, determined for the eight GBCAs still clinically available (other than in Europe), provide a definitive baseline for future evaluations, including theoretical calculations of signal intensity and their clinical impact on T2-weighted scans.
Influence of Maternity Leave on Exclusive Breastfeeding: Analysis from Two Surveys Conducted in the Federal District of Brazil
Authors: Monteiro Fernanda Ramos , Buccini Gabriela dos Santos , Venâncio Sônia Isoyama , da Costa Teresa H. M. 
Published: September 2018

Background: Since the 1980s, Brazil has implemented several initiatives to support breastfeeding. Maternity leave, paid in full for 16 weeks, has been available since 1988. However, few studies in Brazil have analyzed the impacts of maternity leave on breastfeeding using population-based indicators. Research aim: The aim was to analyze the association between maternity leave and exclusive breastfeeding interruption in children younger than 4 months residing in the Federal District of Brazil, in 2008 and 2014. Methods: Data from two surveys were used: the 2008 Second National Survey on Prevalence of Breastfeeding and the 2014 Monitoring of Infant Feeding Practices. The sample included 1,742 mothers with children younger than 4 months residing in the Federal District and using the Public Unified Health System. The main independent variable was the mother being on maternity leave and the outcome was interruption of exclusive breastfeeding. Multiple analyses were performed to test the association between maternity leave and the risk of interrupting exclusive breastfeeding, adjusting for socioeconomic, demographic, and biomedical characteristics. Results: In 2008 and 2014, the prevalence of exclusive breastfeeding was 60% and 71.4% and prevalence of maternity leave was 27% and 41%, respectively. The lack of maternity leave was strongly associated with interruption of exclusive breastfeeding in 2008 (prevalence ratio [PR] = 1.78, 95% confidence interval [CI] [1.12, 2.82]) and in 2014 (PR = 3.95, 95% CI [1.88, 8.31]) after adjusting for confounding variables. Conclusion: Not being on maternity leave was strongly associated with the interruption of exclusive breastfeeding among employed women residing in the Federal District.
Pneumonia in patients with systemic lupus erythematosus: Epidemiology, microbiology and outcomes
Authors: García-Guevara G , Ríos-Corzo R , Díaz-Mora A , López-López M , Hernández-Flores J , Fragoso-Loyo H , Ávila-Vázquez J , Pulido-Ramírez A L , Carrillo-Maravilla E , Jakez-Ocampo J , Sifuentes-Osornio J , Llorente L , Atisha-Fregoso Y 
Published: September 2018

Background and objective Pneumonia remains the main cause of mortality in patients with systemic lupus erythematosus (SLE). The aim of the study was to establish the clinical characteristics, microbiology and risk factors for poor prognosis in patients with SLE and pneumonia. Methods We reviewed medical records of patients with SLE (American College of Rheumatology criteria) and pneumonia who attended the emergency room in a single tertiary care center (January 2010–March 2015). We collected demographics, treatment and disease activity (SLEDAI-2K) data. Severity scales of pneumonia (CURB-65 (acronym for risk factors measured: confusion, urea nitrogen, respiratory rate, blood pressure, 65 years of age and older) and Pneumonia Severity Index (PSI)) were obtained. A negative composite outcome was defined as need for mechanical ventilation, septic shock or death secondary to pneumonia up to 30 days after discharge. We conducted a univariate and multivariable analysis. Results We studied 158 patients (76% women) with 187 episodes of pneumonia. There were no differences in age, SLE duration, SLE activity, treatment or comorbidities between patients with negative composite outcome vs the other group. In 53 episodes, patients presented with a negative composite outcome. Of these, 46 (24.6%) required intubation, 13 (7%) developed shock and 12 (6.4%) died. The most common bacteria isolated was S. aureus, and we observed a high percentage of nonhabitual microorganisms. Fifteen percent of patients who presented with a negative outcome had low values on CURB-65 and PSI scales. Conclusion Patients with SLE and pneumonia have a high risk of complications and present with a high percentage of nonhabitual microorganisms. Severity scales for pneumonia can misclassify as low risk SLE patients with poor prognosis.
Improvement of the Properties of Polyethylene with Chlorinated Polyethylene (CPE)
Authors: Marossy Kálmán , Bárczy Pál 
Published: September 2018

Blends of high density polyethylene (HDPE) and chlorinated polyethylene (CPE) have been tested across the whole concentration range. Polyethylene is used to modify the properties of CPE in the elastomer industry, but modification of the properties of polyethylene with CPE is still not usual. Conventional mechanical tests and dynamic mechanical tests were carried out. The blends were found to be multiphase systems of excellent technological compatibility. Between 10 and 15% by weight CPE increased the modulus of polyethylene. X-ray scattering studies showed that the blends contained structural units not present either in the polyethylene or in the CPE. The blends were melt processable and may have industrial applications, too.
The Effect of Solvent on the Miscibility of Blends of Poly 1-[4-(3-carboxy-4-hydroxy-phenylazo)benzene Sulphonamido -1,2-ethanediyl, sodium salt)] (PAZO) and Polyhydroxybutyrate, (PHB)
Authors: Sharma *Lakshmi , Nishida Koji , Kanaya Toshiji 
Published: September 2018

The commercial world demands new photonic materials, pandering to the consumer's every whim. The target now is to produce an eco-friendly, cost-effective photonic material. This is possible by blending poly 1-[4-(3-carboxy-4-hydroxy-phenylazo)benzene sulphonamido-1,2-ethanediyl, sodium salt)], (PAZO), with polyhydroxybutyrate, (PHB). We analysed the behaviour of PAZO/PHB blends in various solvents, dependent on the solubility parameter calculations for amorphous PHB. Differential Scanning Calorimetry was employed to determine the glass transition temperatures and to assess miscibility. This paper aims to address and establish the effect of the solvent on the miscibility of PHB/PAZO blends. We have established that a complex, is formed at high PHB concentrations, via the O-H bond of the PHB and PAZO in all solvents.
Tensile and Impact Performance of Polypropylene Microcomposite System: Effect of Novel Silica Ash Filler
Authors: Chaudhary Deeptangshu S , Jollands Margaret C 
Published: September 2018

Polypropylene (PP) was used to study filler-polymer interactions when rice hull ash (silica ash) is used as a microfiller. Two sizes (47 and 20 μm) of silica ash particles were studied to obtain quantitative data on the composites' mechanical performance. The smaller particle size was obtained after communizing the original size. Nucleating effects were found, suggesting that there is a moderate polymer-filler interaction during melt-processing. A comparison of the effects of increasing filler loading and increasing surface treatment indicated that at higher filler loadings, the effect of surface treatment was not dominant. Reducing the filler particle size was found to improve tensile modulus and impact strength. Removal of silica ash impurity by burning it off resulted in a significant increase in the above mentioned properties; however, similar results were not obtained after surface treatment of the unburnt ash. The results indicate that there is a possible trade-off between using the silica ash without burning, thus saving on the cost of burning off the impurities, and using the “burnt” ash and saving on the cost of surface modification.
FT-IR Study of the Morphological Interactions in PHB/PAZO Blends and their Dependence on Solvent Variation
Authors: Sharma Lakshmi , Nishida Koji , Kanaya Toshiji 
Published: September 2018

In this article, we demonstrate the vital role the solvent plays in influencing the resultant blend morphology in semi-crystalline PHB/PAZO blends. We will establish the relationship between the blend's FT-IR profiles and the morphology. We will also investigate the possible formation of a PHB/PAZO complex, previously reported. PHB/PAZO blends were prepared in chloroform, acetone and toluene, chosen because of the similarity of their solubility parameter to that of amorphous PHB. The FT-IR spectral bands in PHB responsible for changes in morphology were observed in the 950-1350 cm−1 region. These bands denote the amorphous band at 1185 cm−1, the asymmetric C-O-C vibrations, the CH2 wag and twist at 1231 cm−1 and a crystal vibration at 1279 cm−1. A series of less prominent bands sensitive to the crystalline and amorphous regions were also observed. We deduced that penetration of PHB's crystalline shell by the solvent does occur and is crucial to complex formation and to blend miscibility.
Pultruded Hybrid Fibre (Glass/Carbon) Reinforced Unsaturated Polyester Composites: Mechanical and Thermal Properties
Authors: Chen Chin-Hsing , Lien Kung-Chin 
Published: September 2018

A feasibility study on the pultrusion of hybrid fibre (glass/carbon) reinforced unsaturated polyester composites has been conducted using a proprietary method. This was in order to obtain the best mechanical and thermal properties and the optimum price composites for pultrusion. The static mechanical properties (flexural strength, flexural modulus and notched Izod impact strength), dynamic mechanical properties (dynamic storage modulus, E' and dynamic loss tangent, tanδ) and thermal properties (weight loss by thermogravimetric analysis, TGA) of pultruded hybrid fibre reinforced unsaturated polyester composites were investigated because they are of great interest and importance in structural applications, and very sensitive to the processing conditions. Results show that the flexural modulus increased with increasing carbon fibre content. The flexural strength and notched Izod impact strength increased with decreasing carbon fibre content. The E' increased with increasing carbon fibre content, calcium carbonate content and postcure temperatures. The peak in the loss tangent was shifted to a higher temperature when the carbon fibre content was increased. From TGA, the weight loss of the pultruded composites increased with decreasing carbon fibre content in an inert (N2 gas) atmosphere. Furthermore, they increased with increasing carbon fibre content in an air atmosphere.
Coated Nano-Sized CaCO3 Reinforced Semi-Crystalline EPDM
Authors: Zhou Yabin , Wang Shifeng , Zhang Yong , Zhang Yinxi 
Published: September 2018

Nano-sized calcium carbonate (CaCO3) was used to reinforce a semi-crystalline ethylene-propylene-diene monomer rubber (EPDM). For comparison, micron-sized CaCO3 was also studied. It was found that both nano-sized CaCO3 and micron-sized CaCO3 improved the mechanical properties of the EPDM vulcanizates, and nano-sized CaCO3 exhibited better reinforcement effect than micron-sized CaCO3. The difference in reinforcement effects of nano-sized CaCO3 and micron-sized CaCO3 was explained in terms of the filler particle size and the crosslink density of the vulcanizates. The nano-sized CaCO3 was also modified by titanate, borate, and aluminate-titanate complex coupling agents and used to reinforce EPDM vulcanizates. The results showed that titanate coupling agent coated nano-sized CaCO3 exhibited the best reinforcement ability. FE-SEM micrographs showed that stearic acid, titanate, and aluminate-titanate complex coupling agents could improve the dispersion of the CaCO3 in the rubber matrix remarkably, whereas borate coupling agent could not. The effect of modified nano-sized CaCO3 on the dynamical mechanical properties was also studied. Incorporation of CaCO3 reduced the glass transition temperature (Tg) of the vulcanizates. In comparison with nano-sized CaCO3, micron-sized CaCO3 depressed the Tg more remarkably.
Essential Work of Fracture (EWF) of Multilayer Films
Authors: Poisson C. , Fournier J.E. , Lacrampe M.F. , Krawczak P. 
Published: September 2018

The potential of a fracture mechanics approach (Essential Work of Fracture or EWF method) to determine the toughness of PE/PEgMAH/PA multilayer films has been investigated. The films had been modified either by blending EVA in the PE and PEgMAH layers or by inserting clay nanoparticles in the PA layer. The method was first calibrated on PE and PA single layer films. An analysis of the sensitivity of the toughness, assessed by the EWF method, to both sample geometry and test conditions has been carried out, so as to optimise the testing procedure for these materials. Then these optimal test conditions have been used to characterise PE- and PA-based multilayer films. The results show that the Essential Work of Fracture method is relevant for this type of structure, and may be more sensitive to the film composition variations than standard tensile mechanical tests, especially when the composition modification affects the layer of lowest rigidity and tensile strength.
Effects of Coating Structures on Interfacial Properties of Carbon Fibre/Polyarylacetylene Composites
Authors: Zhang X.Z. , Huang Y.D. , Wang T.Y. , Hu L.J. 
Published: September 2018

Carbon fibres (CF) were modified with different coatings, including vinyltrimethoxysilane (VMS) and vinyl-silsesquioxane (VMS-SSO). VMS-SSO was obtained by the sol-gel hydrolytic condensation of VMS. The structure of VMS-SSO was characterised by FT-IR, NMR (1H, 13C and 29Si) and UV-MALDI-TOF MS. The VMS-SSO included several structures such as cage, semi-cage and ladder. Interlaminar shear strength (ILSS) and interfacial shear strength (IFSS) were measured to evaluate the effects of the coating structure on the interfacial properties of carbon fibre/polyarylacetylene (CF/PAA) composites. The ILSS and IFSS of CF/PAA composites treated with VMS and VMS-SSO coatings showed that VMS-SSO coating had a better treatment effect than VMS. The fracture surface of the CF/PAA composites treated with different coatings was observed by SEM. The complex structures of the VMS-SSO seem to be the main reason for the different degrees of improvement in the interfacial adhesion.
Chemical, Structural and Thermal Changes in PET Caused by Solvent Induced Polymer Crystallisation
Authors: Rajendran S. , Mishra S.P. 
Published: September 2018

The structural and thermal properties of solvent-induced poly(ethylene terephthalate) (PET) polyester have been investigated. Flat, high twist and spun yarns were treated with trichloroacetic acid-methylene chloride (TCAMC) mixed solvent for 5 min at about 25 °C. The treatment influenced the solvent- induced crystallisation in PET, and the high interacting power of TCAMC with PET was substantiated. An increase in X-ray crystallinity was observed in the treated flat yarn but the orientation was reduced. The variation in crystallinity was measured by X-ray and DSC techniques and is discussed. The melting and recrystallisation behaviour of the crystallites were indicated by DSC measurements. The treatment improved the crystallite stability and perfection. Flat yarn exhibited a distribution of the more stable crystals with higher heat of fusion than the respective spun and high twist yarns. The study shows that the crystalline structure reorganises to a more stable and uniform form as a result of the treatment. Double melting peaks were seen in the DSC of the high twist treated samples.
Phase Transition and Degradation Characteristics of Poly(urethane-Siloxane) Copolymers
Authors: Yeh Jen-Taut , Shu Yao-Chi 
Published: September 2018

Poly(urethane-siloxane) (PU-Si) copolymers consisting of soft and hard phases presented a two-phase structure when analysed by differential scanning calorimetry. The copolymers showed a narrow glass transition region of soft segment between −116 °C and −119 °C and a narrow breadth of this transition within 3 °C. Both results indicated that the copolymers had a high degree of phase separation. The stress-strain curves showed that the copolymer with high phase separation exhibited low tensile strength. The hard phase presented several endothermic regions above room temperature. The first and second endothermic regions, which can be regarded as a short-range ordering and a long-range ordering respectively, appeared at about 60~120 °C and 160~200 °C. An endothermic peak appeared at around 200 °C which was attributable to a crystalline region. Two-stage degradation of copolymers was clearly observable in thermogravimetric analysis (TGA). Although the degradation of the copolymers was similar to that of typical polyurethane (PU), the shoulder of the derivative thermogram (DTG) curve was different. To examine this unique shoulder, the copolymers were examined using a slower heating rate. There were four stages of degradation, which was again different from the behaviour of PU. Degradation of the hard phase occurred between 200~400 °C in two stages, resulting from two distinct hard-segment types. Degradation of the soft phase occurred between 400~600 °C and there were also two stages related to the decomposition of PDMS soft segments and macroclics.
Synthesis and Properties of Poly(Methylphenylsiloxane) Containing Methacryloyl Groups
Authors: Sun J.T. , Huang Y..D. 
Published: September 2018

Methacryloxypropyltrimethoxysilane (MPTS) was used as the modified monomer to synthesise polymethylphenylsiloxane containing methacryloyl groups (PMPS-M) through co-hydrolysis and polycondensation with other silane monomers. The effects of MPTS on the synthesis and on the thermal and adhesive properties of PMPS-M were investigated by using Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), differential thermogravimetry (DTG), scanning electron microscopy (SEM), and measurements of adhesion using a shear test. The results indicated that PMPS-M with good storage stability was synthesised successfully when the amount of MPTS was less than 8 wt%. PMPS-M had higher thermal stability than PMPS. The onset degradation temperature for PMPS-M containing 8 wt% MPTS was 518 °C, while it was 463 °C for PMPS. The improvement in thermal stability may be due to the protective effect of the methacryloyl groups, as observed under SEM. The shear strength of PMPS-M was 4.2 MPa when containing about 8 wt% MPTS, about 50% higher than that of PMPS. The shear strength of PMPS-M was also higher than that of PMPS at high temperatures.
Incremental Damage Development in a 3D Woven Carbon Fibre Composite
Authors: King S. , Stewart G. , McIlhagger A.T. , Quinn J.P. 
Published: September 2018

Interest in 3D woven carbon fibre composites has increased within industries such as aerospace, automotive and marine, due to their high strength to weight ratio, their increased tailorability and their capacity to be manufactured into near net shape preforms, thereby reducing parts count, assembly time, labour intensity and costs. It is vital that critical areas of concern such as damage (and in particular damage initiation and development) are studied and understood, thereby reducing the limiting factors to their acceptance. The damage initiation and subsequent intervals of development for ILSS (Interlaminar Shear Strength) were determined experimentally. Particular focus is paid to the significance of binder edge and binder middle testing and the influence of through-the-thickness (T-T-T) reinforcement in relation to damage types and development. Control samples for binder edge and binder middle loading locations were tested to failure as a means of determining an average point of failure, allowing the generation of testing intervals. The performance and architecture of samples from each incremental interval were characterised using a combination of graphical analysis and optical microscopy with the aid of dye-penetrant to highlight fibre damage and matrix cracking. Samples displayed specific damage initiation points, thus allowing the generation of a damage guide relating to applied force. In addition, the results imply that a relationship exists between the location of applied load and subsequent damage, thus showing the significant influence played by the T-T-T binder loading location on damage development within 3D woven carbon fibre composites. Some of the preliminary data shown in this paper was presented at IMC23 at the University of Ulster, UK in August 2006 and at Texcomp 8 in Nottingham, UK October 2006.
An Investigation into the Effect of Compaction on the Mechanical Performance of a 3D Reinforced Advanced Composite
Authors: Stewart G. , McIlhagger A.T. , Quinn J.P. , King S. 
Published: September 2018

Industries such as aerospace, marine, automotive and construction are now embracing advanced composites processed using resin infusion techniques. These composites consist of complex fibrous reinforcements and polymeric matrices. They can offer lower costs and equivalent or greater performance than can composites produced via more expensive traditional techniques such as autoclaving. As a result they are gaining increasing acceptance. One such material is a 3D fibre reinforced composite which possesses superior strength and stiffness in the through-the-thickness (T-T-T) direction compared to 2D composites due to their T-T-T binder tows. However, due to the T-T-T binder it is harder to achieve the required high fibre volume fraction (Vf) for optimum performance. This paper investigates a 3D fibre reinforced composite and how its structure and mechanical properties are affected by increasing Vf. Some preliminary results in this paper were presented as a conference paper at IMC23 in August 2006.