bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Artificial Disc: Chemical and Biomechanical Analysis
Authors: Mercuri D. , Leone G. , Barbucci R. , Favaloro R. , Facchini A. , Signori F. , Bronco S. , Ciardelli F. 
Published: June 2008

AbstractSummary:Degeneration of intervertebral discs is the most common cause of back pain. The first phase of this degenerative process involves the nucleus pulposus. A rapid recovery of this structure can prevent further degradation of the annulus fibrosus. Guar Gum is an hydrophilic polysaccharide extracted from the seed endosperm of a plant. Through a cross‐linking procedure a Guar hydrogel was synthesized. The Guar hydrogel could be injected by a syringe and it is a good candidate as a nucleus pulposus substitute. For the preparation of the artificial fibrosus annulus, commercially available polymer materials are tuned to achieve suitable mechanical properties. To achieve this peculiar behaviour, the main strategy investigated is the dispersion of hollow polymer micro spheres in a thermoplastic polymer matrix. Processing conditions and particle content are finely tuned to get the target mechanical behaviour.
Preparation of Porous Protein‐Based Hydogel for Highly Sensitive Protein Chips
Authors: Tanaka Hiroyuki , Shiroya Toshifumi , Hanasaki Minako , Isojima Tatsushi , Takeuchi Hisao , Kawaguchi Haruma 
Published: June 2008

AbstractSummary:Protein chips are important tools for high‐throughput analysis of biological events. We have developed a novel method to prepare a protein‐based hydrogel, that is, a “Three‐Dimensional Nano‐structured Protein Hydrogel” (3‐D NPH), which is composed of protein and polymer nano‐particles. The 3‐D NPH could be easily prepared by dispensing a protein and polymer mixture on a substrate. Surprisingly, gold particles conjugated with protein A diffused into the 3‐D NPH which was made of mouse IgG through the pores. We have shown that the protein chips made with our 3‐D NPH method has tremendously improved sensitivity in detecting protein‐protein interactions compared with that of direct protein immobilization methods.
Stimulations of Responsive Hydrogels: Experimental Investigations and Modelling
Authors: Maurer Gerd 
Published: June 2008

AbstractSummary:Modelling the responses of hydrogels to external stimulations requires a thermodynamic framework for the phase equilibrium between a gel and a surrounding phase and models for describing the Gibbs energies of both phases. The phase equilibrium conditions are described and some appropriate models for describing the thermodynamic properties are presented. These methods are applied to describe (correlate/predict) the swelling of nonionic hydrogels (of n‐isopropyl acrylamide) and ionic hydrogels (of n‐isopropyl acrylamide and sodium methacrylate) in various nonionic and ionic aqueous solutions at 298 K.
Micro and Macro Characterization of PEO‐PPO‐PEO Triblocks Hydrogels
Authors: Fusco S. , Borzacchiello A. , Cohn D. , Netti P. A. 
Published: June 2008

AbstractSummary:Amphiphilic poly(ethylene oxide) ‐ poly(propylene oxide) triblock copolymers are very appealing materials for biomedical application since they can be easily injected as liquid at room temperature while they produce a gel when in the body. On the other hand, these materials no longer hold the gel state when in presence of solvent (as physiological solutions) due to the dilution of the system. To overcome these limitations Cohn and coworkers1 have synthesized a novel thermo‐responsive systems by extending the chain of the commercially available PEO‐PPO copolymer named F127. The aim of this study was to evaluate the effect of the chemical modification on the macroscopic, rheological, and microscopic, transport, properties of these new materials.
Elucidation of the Mechanism of Enhanced Insulin Uptake and Release from pH Responsive Hydrogels
Authors: Tuesca Anthony , Lowman Anthony 
Published: June 2008

AbstractSummary:Environmentally responsive hydrogels composed of poly(methacrylic acid‐g‐ethylene glycol) (P(MAA‐g‐EG)) have shown promise for oral insulin delivery due to their pH responsive complexation behavior. A series of hydrogel formulations were polymerized with varying amounts of crosslinker and varying monomer volume fraction. The mesh size of the network depended primarily on pH, varying from 8.0 to 27.2 nm. Insulin loading efficiency varied directly with crosslink density, ranging from 42.7 to 84.9% of available insulin loaded into the hydrogels. The release of insulin was performed with each polymer formulation at 5 pH levels ranging from 2.7 to 6.8. Insulin release was less than 20% for all formulations tested with insulin for the duration of the 3 hour release study for all pH levels considered except when the pH was 6.8, at which point the release occurred as a burst. Loading studies performed with insulin glargine, an insulin analog with an increased pI, showed the same trends as native insulin. However, the release of insulin glargine only occurred at a pH level above that of the pI of the protein. These results indicate that hydrogen bonds and ionic interactions between the protein and P(MAA‐g‐EG) may strongly influence its loading and release behavior in vitro.
Recurrent metastatic neuroblastoma followed by myelodysplastic syndrome: Possible leukemogenic role of temozolomide
Authors: Kushner Brian H. , Laquaglia Michael P. , Kramer Kim , Modak Shakeel , Cheung Nai‐Kong V. 
Published: June 2008

AbstractAn 8‐year old child had a pelvic MYCN‐nonamplified neuroblastoma (NB) with retroperitoneal nodal extension. Multi‐modality therapy achieved complete remission (CR). Small recurrences confined to left supraclavicular nodes were treated with surgery alone at 4.9, 6.5, 7.5, 9.5, and 12.9 years from diagnosis. Monitoring through 12 months after the last resection showed CR. When she returned 34 months later (16.8 years from diagnosis), she had massive disease in the left neck and upper trunk, without osteomedullary metastases. Salvage therapy featured 11 cycles of temozolomide. She developed myelodysplastic syndrome with 45,XX,der(7)t(7;21) (p15;q11),‐21 at age 24 and refused treatment; 19 months later she was transfusion‐dependent but her NB remained in CR. Pediatr Blood Cancer 2008;51:552–554. © 2008 Wiley‐Liss, Inc.
Virilizing ovarian tumor in a 14‐year‐old female with a prior familial multinodular goiter
Authors: Niedziela Marek 
Published: June 2008

AbstractA 14‐year‐old female presented with intermittent abdominal pain, deepening of voice and amenorrhoea for 4 months. Twelve months earlier she had had a thyroidectomy because of familial multinodular goiter and had, subsequently, received substitution with L‐thyroxine. At the time of admission, a high serum testosterone level was detected. The dexamethasone suppression test confirmed the hormonal autonomy and magnetic resonance imaging (MRI) visualized a solid tumor within the left ovary. The pathological diagnosis after left salpingo‐oophorectomy was Sertoli‐Leydig cell tumor. The patient has remained disease‐free for 6 years. Pediatr Blood Cancer 2008;51:543–545. © 2008 Wiley‐Liss, Inc.
Preparation and characterization of nanocomposite material based on polyurethane acrylate macromonomer
Authors: Fang Shao‐Ming , Zhou Li‐Ming , Gao Li‐Jun , Liu Dong‐Liang , Zhang Hai‐Bo 
Published: June 2008

AbstractIn the present investigation, a macromonomer of polyurethane acrylate (PUA) was synthesized, and novel netlike nanocomposite materials were prepared through in situ polymerization of polyurethane acrylate macromonomers in the presence of organically modified montmorillonite (oMMT). The structure of oMMT was compared with untreated MMT by Fourier transform infrared (FTIR) and X‐ray diffraction (XRD). Transmission electronic microscopy (TEM) studies showed that the silicate layers of oMMT were dispersed homogeneously in the polymer matrix. Tensile test, impact test, and thermal gravity analysis proved that the mechanical and thermal properties of the nanocomposites are superior to those of the pure system, and the mechanical properties of the cured hybrid reach maximum while the content of oMMT is 1.5 wt%. Surprisingly, dynamic mechanical thermal analysis (DMTA) displayed that the glass transition temperature (Tg) of the nanocomposites decreased with increasing the oMMT contents. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
The shock and release behavior of an aerospace‐grade cured aromatic amine epoxy resin
Authors: Hazell P.J. , Stennett C. , Cooper G. 
Published: June 2008

AbstractKnowing the dynamic behavior of polymer materials that are used in the construction of fiber‐reinforced composite materials is particularly important for such materials that are subjected to impact. In this work, we have conducted a number of plate‐impact experiments on a commercially important aromatic amine epoxy resin that is used in the construction of carbon fiber composite materials. The measured Hugoniot in shock velocity–particle velocity space was Us = 2.65 + 1.55 up (ρ0 = 1.141 g/cc), and is similar to the measured Hugoniots of other resins presented by different researchers. We have also measured the longitudinal stress in the shocked material and shown, in common with other polymers, that above a threshold stress, an increase in shear strength with impact stress is observed. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Preparation, structure, and properties of the PTT/SGF composites
Authors: Run Mingtao , Song Hongzan , Hao Yanping , Hu Xiaomin , Yao Chenguang 
Published: June 2008

AbstractShort glass fiber reinforced poly(trimethylene terephthalate) composites (PTT/SGF) were prepared by twin screw extruder. The structural feature and physical properties of these composites were studied by scanning electron microscope, differential scanning calorimetry, thermalgravimetric analyzer, capillary rheometer, universal tester, etc. The glass fiber was modified by the silane coupling agent before being blended with the polymer. The results suggest that there is strong interaction between SGF and PTT matrix, which leads to an increasing on the tensile strength, Young's modulus, impact strength and thermal stability of the composites with proper contents of SGF. Rheological behavior of the PTT/SGF composites melt is complicated, combining a dilate fluid at lower shear rate and a pseudo‐plastic fluid at higher shear rate. The melt apparent viscosity of composites decreases with increasing SGF content because of the rigid fibers improving the flow of the melt. Moreover, the flow activation energy of the composites suggests that the melt with more SGF has lower sensitivity to the processing temperature. In conclusion, the composite with 10–20 wt% content of SGF has better properties. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Ethylene vinyl acetate/Mg‐Al LDH nanocomposites by solution blending
Authors: Kuila T. , Acharya H. , Srivastava S.K. , Bhowmick A.K. 
Published: June 2008

AbstractPartially exfoliated ethylene vinyl acetate (EVA‐40, 40% vinyl acetate content)/layered double hydroxide (LDH) nanocomposites using organically modified layered double hydroxide (DS‐LDH) have been synthesized by solution intercalation method. X‐ray diffraction (XRD) and transmission electron microscopy (TEM) studies of nanocomposites shows the formation of exfoliated LDH nanolayers in EVA‐40 matrix at lower DS‐LDH contents and partially intercalated/exfoliated EVA‐40/MgAl LDH nanocomposites at higher DS‐LDH contents. These EVA‐40/MgAl LDH nanocomposites demonstrate a significant improvement in tensile strength and elongation at break for 3 wt% of DS‐LDH filler loading compare to neat EVA‐40 matrix. Thermogravimetric analysis also shows that the thermal stability of the nanocomposites increases with DS‐LDH content in EVA‐40. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Study of the modification of the properties of (PP/EPR) blends with a view to preserving natural resources when elaborating new formulation and recycling polymers
Authors: Mnif Nizar , Massardier Valérie , Kallel Tasnim , Elleuch Boubaker 
Published: June 2008

AbstractThe aim of the present work is to study how CaCO3, very abundant on earth, can be blended with polypropylene/ethylene propylene rubber (PP/EPR) either to preserve natural resources when elaborating virgin formulations or to simulate mixtures of waste made of CaCO3 filled PP with PP/EPR which could result from end‐of‐life‐vehicles (ELV). The article focuses on the studies of PP/EPR blends, used in the manufacture of automobile fenders, in the presence of nano‐CaCO3 and compatibilizers. Blends of various compositions (with and without compatibilizer and nanoparticles) were prepared using a corotating twin‐screw extruder. The results were compared with the ones presented by a commercial (PP/EPR) blend. The experiments included mechanical tests, differential scanning calorimetry, scanning electron microscopy, and dynamic mechanical analysis experiments. The presence of the compatibilizers in the (PP/EPR) blends decreases the size of elastomer particles, improves the adherence to the interface and improves the mechanical properties. The nano‐CaCO3 would also seem to act as a nucleating agent in the PP/EPR matrix; it increases the cristallinity and the Young modulus of the blends. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Morphology, mechanical, and dielectric breakdown properties of PBT/PET/TPE, PBT/PET/PA66, PBT/PET/LMPE, and PBT/PET/TiO2 blends
Authors: Park Eun‐Soo 
Published: June 2008

AbstractThe morphology and thermal behavior of tertiary blends of poly(butylene terephthalate) [PBT]/poly(ethylene terephthalate) [PET] alloy resin (Alloy)/thermoplastic elastomer (TPE), Alloy/nylon 66 (PA66), Alloy/low molecular weight polyester (LMPE), and Alloy/titanium dioxide (TiO2) have been investigated by scanning electron microscopy, differential scanning calorimetry, and thermogravimetry (TG). In case of TPE and LMPE containing blends did not show any morphological change compared with Alloy whereas for PA66 containing blends, the size of the dispersed phase increased with the increase the PA66 contents. The crystallization peak of Alloy/TPE blends became undetectable with an increasing TPE content. In contrast, the crystallization temperature (Tc1) of Alloy/PA66, Alloy/LMPE, Alloy/TiO2 blends increased significantly as the PA66, LMPE, and TiO2 content increases. TG traces show a significant shift of the weight loss towards higher temperature for Alloy/TiO2 blend whereas Alloy/TPE, Alloy/PA66 and Alloy/LMPE blends slightly decreases in thermal stability than Alloy. To investigate the applicability for insulation material, the prepared blend samples were extruded an electric wire and the breakdown voltage (BDV) of wires was investigated. The melt flow rate of Alloy increased as the amount of TPE increased, and a contrary trend was found when the increase of the amount of TiO2. The dielectric breakdown test applies a voltage that is greater than the product's rated operating voltage for a specific period of time during which dielectric breakdown must not occur. The BDV of Alloy/TPE and Alloy/PA66 blends is higher than other blends before and after thermal aging 225°C for 30 min. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
In situ reinforcement of poly(butylene terephthalate) and butyl rubber by liquid crystalline polymer
Authors: Kumar S. , Rath T. , Mahaling R.N. , Das C.K. , Srivastava R.B. , Yadaw S.B. 
Published: June 2008

AbstractTernary in situ butyl rubber (IIR)/poly(butylene terephthalate) (PBT) and liquid crystalline polymer (LCP) blends were prepared by compression molding. The LCP used was a versatile Vectra A950, and the matrix material was IIR/PBT 50/50 by weight. Morphological, thermal, and mechanical properties of blends were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimetry, and thermogravimetric analysis (TGA). Microscopy study (SEM) showed that formation of fibers is increasing with the increasing amount of LCP A950. Microscopic examination of the fractured surface confirmed the presence of a polymer coating on LCP fibrils. This can be attributed to some interactions including both chemical and physical one. The increased compatibility in polymer blends, consisting of IIR/PBT, by the presence of LCP A950 may be explained by the adsorption phenomena of the polymer chains onto the LCP fibrils. SEM and AFM images provided the evidence of the interaction between IIR/PBT and the LCP. Dynamic mechanical analyses (DMA) and TGA measurements showed that the composites possessed a remarkably higher modulus and heat stability than the unfilled system. Storage modulus for the ternary blend containing 50 wt% of LCP exhibits about 94% increment compared with binary blend of IIR/PBT. From the above results, it is suggested that the LCP A950 can act as reinforcement agent in the blends. Moreover, the fine dispersion of LCP was observed with no extensional forces applied during mixing, indicating the importance of interfacial adhesion for the fibril formation. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Preparation and characterization of chitosan/KSF biocomposite film
Authors: Altınışık Aylin , Seki Yoldaş , Yurdakoç Kadir 
Published: June 2008

AbstractChitosan–clay biocomposites have been prepared in which KSF‐montmorillonite (KSF) is used as filler and diluted acetic acid is used as solvent for dissolving and dispersing chitosan and montmorillonite, respectively. The effect of KSF loadings in biocomposites has been investigated. The characterization with different methods (FTIR, DSC, TGA, SEM, and XRD) on chitosan/KSF biocomposites systems was examined. Morphology and properties of chitosan biocomposites have been studied compared with those of pure chitosan. The FTIR and SEM results indicated the formation of an intercalated‐and‐exfoliated structure at low KSF content and an intercalated‐and‐flocculated structure at high KSF content. The thermal stability and the mechanical properties of the composites were also examined by DSC, TGA/DTG, and tensile strength measurements, respectively. The dispersed clay improves the thermal stability of the matrix systematically with the increase of clay loading. Tensile strength of a chitosan film was enhanced until the clay ratio up to 2 wt% and elongation‐at break decreased with addition of clay into the chitosan matrix. The XRD results confirmed the intercalation of the biopolymer in the clay interlayer by the decrease of 2θ values while the chitosan–clayratio increases. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Effects of resin storage aging on rheological property and consolidation of composite laminates
Authors: Gu Yizhuo , Li Min , Zhang Zuoguang , Li Yanxia 
Published: June 2008

AbstractThe ability to predict the viscosity of thermoset resin is important to understand the manufacturing process of composites and optimize the processing parameters. During resin or prepreg storage course, the cure reaction may happen and the degree of cure increases gradually. The storage aging effect reduces the fluidity of resin, and hence alters the processability of resin. In this article, the rheological properties of an epoxy resin and a bismaleimide resin used in composite autoclave process were measured and a viscosity model was established, which can predict the viscosity progression during cure for different aging degree of resin. Moreover, a computer simulation method was used to study the effects of aging degree on the composite consolidation and the processing operations. It is found that the viscosity model of aged resin can be obtained by modified dual Arrhenius model of fresh resin with the dynamic rheological measurement. The resin aging strongly alters the flowability, so influences composite consolidation. According to the simulated results, the processing parameters need to be adjusted to achieve cured composites with appropriate fiber content. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Synthesis of polyacrylate/poly(ethylene glycol) hydrogel and its absorption properties for heavy metal ions and dye
Authors: Tang Qunwei , Wu Jihuai , Sun Hui , Fan Shijun , Hu De , Lin Jianming 
Published: June 2008

AbstractA novel polyacrylate/poly(ethylene glycol) (PAA/PEG) hydrogel was synthesized by a simple two‐step aqueous prepolymerization method. The deswelling properties were investigated in the case of changing the neutralization degrees of PAA, the pHs and the concentration of multivalent salt solutions. Methyl orange (MO) dye can be adsorbed and released using the swelling–deswelling property of the PAA/PEG hydrogel. The PAA/PEG hydrogel can adsorb MO of 29 mg/g at equilibrium and release about 80% in 30 min. Based on the deswelling property, the dyes in wastewater can be reclaimed and reused. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Diffusion‐weighted MR imaging and apparent diffusion coefficient of the normal fetal lung: preliminary experience
Authors: Manganaro Lucia , Perrone Anna , Sassi Simona , Fierro Francesca , Savelli Sara , Di Maurizio Marco , Tomei Alessandra , Francioso Antonella , La Barbera Laura , Giancotti Antonella , Ballesio Laura 
Published: June 2008

AbstractObjectiveTo assess if a correlation is present between apparent diffusion coefficient (ADC) values and normal lung maturation during gestation to define potential reference values as indicators of the lung development.MethodsOur study included 50 pregnant women (gestational age, GA: 18–36 weeks), with normal fetal development of lungs assessed by a previous obstetric ultrasound (US), and then confirmed by our magnetic resonance (MR) examination. We used T2‐weighted sequences, diffusion‐weighted imaging sequences (DWI) and ADC maps for studying pulmonary tissue. In all cases the resulting ADC values were related to GA using Pearson correlation.ResultsADC values ranged from 1,2 µm2/ms at 18 weeks' gestation to 3,9 µm2/ms at 36 weeks' gestation with a mean value, regardless for the gestational age, of 2, 352 ± 0,623106 µm2/ms. We found a significant correlation between ADC and gestational age (Pearson correlation = 0,816).ConclusionThe ADC values correlate with gestational age since alveolar fluid secretion and angiogenesis increase gradually. Therefore, ADC can be considered as a new parameter for studying lung maturity. Copyright © 2008 John Wiley & Sons, Ltd.
Expectation and knowledge of pregnant women undergoing first and second trimester ultrasound examination in a Chinese population
Authors: Chan Lin Wai , Chan Oi Ka , Chau Mo Ching Macy , Sahota Daljit Singh , Leung Tak Yeung , Fung Tak Yuen , Lau Tze Kin 
Published: June 2008

AbstractObjectiveTo evaluate expectation and knowledge on obstetric ultrasound examination in the first and second trimester in a Chinese population.MethodA cross‐sectional survey was conducted in a university obstetric clinic in Hong Kong. Chinese pregnant women who underwent the first trimester early scan sessions, or the second trimester anomaly scan sessions were invited to complete a self‐administered questionnaire, which contained items on their knowledge, expectation, and sociodemographic characteristics.ResultsIn all 276 eligible pregnant women (117 in the first trimester and 159 in the second trimester) were recruited. Although 249 women (90.2%) claimed they understood the indication of the ultrasound examination, only 93 of them were correct (33.7%). The median perceived overall‐detection rate for structural abnormalities was 66.5%. Living in Hong Kong for more than 7 years was significantly associated with higher knowledge level and expectation from ultrasound examination. Attaining tertiary education level was also significantly associated with higher knowledge level. Over 90% of the pregnant women studied wished to know the fetal gender from the anomaly scan examination.ConclusionKnowledge of Chinese pregnant women on ultrasound was generally unsatisfactory. Understanding their limitation of knowledge and expectations helps to devise appropriate education in the local setting. Copyright © 2008 John Wiley & Sons, Ltd.