bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave-assisted ionic liquid phase synthesis of phthalonitrile polymers
Authors: Selvakumar Palaniappan , Sarojadevi Muthusamy , Sundararajan Pudupadi 
Published: August 2011

Abstract
A novel, efficient methodology for the synthesis of phthalonitrile derivatives was investigated, using ionic liquid (IL) and microwave media as well as both simultaneously. Phthalonitrile monomers containing imide linkages were prepared from the reaction between aromatic dianhydrides, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BPTA), pyromellitic dianhydride (PMDA), 4,4′-(hexafluroisopropylidene) diphthalic anhydride (6FDA), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BTDA) and the end-capping agent 4-(3-aminophenoxy)phthalonitrile through the imidization reaction. The use of the IL1-butyl-3-methyl imidazoliumchloride as a solvent significantly increased the rate and yield of the reaction. The use of microwave irradiation and reaction parameters significantly shortened the reaction time while enhancing the purity. The polymerization of the prepared phthalonitrile monomers was carried out with 3 wt% of aromatic diamine 4,4′-oxydianiline (ODA) curing agent under microwave irradiation. It is shown that condensation was successfully carried out using the recyclable IL medium under microwave irradiation.
Ultrasound assisted process of PA6/clay nanocomposites: mechanical, rheological and barrier properties
Authors: Swain Sarat K. 
Published: August 2011

Abstract
Polymer/clay nanocomposites were prepared by the single screw extruder with an attached die to an ultrasound of variable amplitude. The structure and morphology of nanocomposites were studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Mechanical properties such as Young’s modulus, elongation, breaking stress, toughness, yield stress and yield stain of ultrasonically treated nanocomposites were changed significantly in comparison to untreated nanocomposites. From rheology data, it was found that the complex viscosities of nanocomposites were increased with clay loading and decreased after ultrasonic treatment. It was found that both clay and ultrasonic intensity played a vitalrole in the dispersion of clay in the polymer matrix. From the differential scanning calorimeter (DSC) results it was found that the addition of clay in the nylon 6 matrix leads to a decrease of crystallization and this property increased ultrasonic amplitude. The oxygen permeability of PA6/clay nanocomposites was measured and it was found that a substantial reduction in oxygen permeability was observed by increasing clay loading.
A comparative study of polyelectrolyte induced metachromasy
Authors: Nandini Ratnakar , Vishalakshi Bedalamole 
Published: August 2011

AbstractThe interaction of two cationic dyes, namely crystal violet (CV), with anionic polyelectrolytes, namely sodium carrageenate (NaCar) and sodium heparinate (NaHep), has been investigated by spectrophotometric method. The polymers induced metachromasy in the dye resulting in the shift of the absorption maxima of the dyes towards shorter wavelengths. The stability of the complexes formed between crystal violet and sodium carrageenate was found to be greater than that formed between crystal violet and sodium heparinate. This fact was further confirmed by reversal studies using alcohols, urea surfactants and electrolytes. The interaction parameters revealed that binding between crystal violet and sodium carrageenate was mainly due to electrostatic interaction while that between crystal violet and sodium heparinate is found to involve both electrostatic and hydrophobic forces.
Applicability of time temperature superposition principle to an immiscible blend of polyphenyleneoxide and polyamide
Authors: Hardikar Narendra A. , Bobba Somasekhar , Jha Roshan 
Published: August 2011

Abstract
The immiscible blend of polyphenyleneoxide (PPO) and polyamide (PA) is used in several applications exposed to high temperature. The complexity of numerical modeling of such materials is dependent on their thermorheological behavior with significant simplification possibilities, if the material is found to follow the time temperature superposition (TTS) principle and show thermorheological simplicity (TRS). Hence as a precursor to selecting accurate constitutive modeling approach, the paper investigates the applicability of the TTS principle and the nature of thermorheological behavior to the blend. Dynamic mechanical analysis (DMA)frequency scans were performed in the range of 0.1–100 rad/s from 0°C to 210°C at 10°C intervals. Temperature dependency was observed on the Cole-Cole plot pointing to the thermorheological complexity and the need for vertical shift factors. 2-D minimization algorithm was used to shift the isotherms horizontally and vertically to obtain master curves. Except, in the vicinity of glass transition temperature T

g
, the isotherms overlap to form a master curve, but further analysis considering various conditions indicate that in a strict sense TTS is not applicable to the blend when both storage G′ and loss modulus G″ are considered. However, a continuous master curve of storage modulus spanning 31 decades of time is obtained using horizontal shifting alone when loss modulus is neglected. Further testing is required to ascertain if relaxation modulus can be approximated with storage modulus alone before taking recourse to characterization methods developed for thermorheologically complex (TRC) materials.
Structural and electrical characterization of plasticized PVA: AgI polymer electrolyte
Authors: Prajapati Govind K. , Roshan Rupesh , Gupta Prem N. 
Published: August 2011

Abstract
The development of new polymeric systems with high ionic conductivity is one of the main objectives in the field of polymer materials with application point of view. In the present work, Ag+ion conducting solvent free composite polymer electrolyte thin films have been prepared using polyvinyl alcohol (PVA) as host polymer and polyethylene glycol (PEG) as plasticizer by standard solution cast technique. The structural characteristics of the prepared films have been obtained from X-ray diffraction (XRD) patterns. Maximum room temperature ionic conductivity of order of 10-5S cm-1 is obtained using complex admittance (B-G) spectroscopy. The temperature dependent conductivity shows two distinct regions of Arrhenius type thermally activated behavior before and after glass transition temperature. Dielectric constant, ε′ and dielectric loss, ε″ of the samples increases with temperature which is similar in behavior as that of conductivity. The activation energy for ion conduction has been calculated from temperature dependent conductivity curve and its minimum value is found to be 0.30 eV for PVA-PEG-20% AgI polymer electrolyte sample. High value of transference number shows that samples are ionic in nature which is confirmed by Wagner’s polarization technique.
Probabilistic Heterogeneous Patent Protection and Innovation Incentives
Authors: Spinesi Luca 
Published: August 2011

Abstract
Using a general equilibrium framework, this paper shows that imperfect and heterogeneous patent protection across industries affects the relative innovation incentives of firms and the skill premium. It is found that tighter patent enforcement in some industries allows a patent enforcement externality effect to emerge, whereby varieties with relatively softer patent protection have relatively stronger innovation incentives. The theoretical mechanisms hold for a wide range of the elasticity of substitution between varieties and also hold in a North-South framework when IPR harmonization is considered. A numerical simulation shows that merging both endogenous technological change and institutional aspects in the form of imperfect and heterogeneous IPR protection can contribute to explaining the different innovation and wage inequality performances of the U.S. and the EU regions.
Limited Overlap Between Intermediate Hyperglycemia as Defined by A1C 5.7–6.4%, Impaired Fasting Glucose, and Impaired Glucose Tolerance
Authors: Saukkonen Tuula , Cederberg Henna , Jokelainen Jari , Laakso Mauri , Härkönen Pirjo , Keinänen-Kiukaanniemi Sirkka , Rajala Ulla 
Published: August 2011

OBJECTIVE
We compared the prevalences and overlap between intermediate hyperglycemia (IH), defined by a hemoglobin A1c (A1C) 5.7–6.4%, impaired fasting glucose (IFG), and impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS
Oral glucose tolerance test results and A1C measurements were evaluated as markers of IH in an unselected cohort of 486 nondiabetic adults from Finland.

RESULTS
The overall prevalence of IH was 34%. Prevalences of isolated A1C 5.7–6.4%, IGT, and IFG were 8.0, 13.2, and 4.5%, respectively. Overlap between these three markers was uncommon. Isolated A1C 5.7–6.4% was associated with a higher BMI compared with isolated IFG and IGT and with a more adverse lipid profile compared with isolated IFG.

CONCLUSIONS
Prevalence of isolated IH was high, with limited overlap between the definitions. Differences in cardiovascular disease risk factors were observed among the groups. This study demonstrates that an A1C of 5.7–6.4% detects, in part, different individuals with IH compared with IFG and IGT.
Adapting Models of Chronic Care to Provide Effective Diabetes Care for Refugees
Authors: Heerman William J. , Wills Morgan J. 
Published: August 2011

IN BRIEF
Adapting current models of diabetes care for refugees requires careful attention to diverse cultures, the refugee experience with trauma, and different paradigms of health and illness. Improving health literacy and self-efficacy, forming community partnerships, and providing community education will create the best chance for high-quality diabetes care in the refugee population in the United States.
Statistical and evolutionary optimisation of operating conditions for enhanced production of fungal l-asparaginase
Authors: Baskar Gurunathan , Renganathan Sahadevan 
Published: August 2011

AbstractA three-level central composite design of the Response Surface Methodology and the Artificial Neural Network-linked Genetic Algorithm were applied to find the optimum operating conditions for enhanced production of l-asparaginase by the submerged fermentation of Aspergillus terreus MTCC 1782. The various effects of the operating conditions, including temperature, pH, inoculum concentration, agitation rate, and fermentation time on the experimental production of l-asparaginase, were fitted to a second-order polynomial model and non-linear models using Response Surface Methodology and the Artificial Neural Network, respectively. The Artificial Neural Network model fitted well, achieving a higher coefficient of determination (R 2 = 0.999) than the second-order polynomial model (R 2 = 0.962). The l-asparaginase activity (38.57 IU s mL−1) predicted under the optimum conditions of 32.08°C, pH of 5.85, inoculum concentration of 1 vol. %, agitation rate of 123.5 min−1, and fermentation time of 55.1 h was obtained using the Artificial Neural Networklinked Genetic Algorithm in very close agreement with the activity of 37.84 IU mL−1 achieved in confirmation experiments.
Iterative Modernism
Authors: De Block Greet , De Meulder Bruno 
Published: August 2011

This article traces the implicit spatial project of Belgian engineers during the interwar period. By analyzing infrastructure planning and its inscribed spatial ideas as well as examining the hybrid modernity advocated by engineers and politicians, this article contributes to both urban and transport history.Unlike colleagues in countries such as Germany, Italy and the United States, Belgian engineers were not convinced that highways offered a salutary new order to a nation traumatized by the First World War. On the contrary, the Ponts et Chaussées asserted that this new limited access road would tear apart the densely populated areas and the diverse regional identities in Belgium. In their opinion, only an integration of existing and new infrastructure could harmonize the historically fragmented and urbanized territory. Tirelessly, engineers produced infrastructure plans, strategically interweaving different transport systems, which had to result in an overall transformation of the territory to facilitate modern production and export logics.
Lack of Th17 Cell Generation in Patients with Severe Burn Injuries
Authors: Inatsu Akihito , Kogiso Mari , Jeschke Marc G. , Asai Akira , Kobayashi Makiko , Herndon David N. , Suzuki Fujio 
Published: August 2011

Abstract
Immunodeficient patients with severe burn injuries are extremely susceptible to infection with Candida albicans. In addition to Th1 cells, IL-17–producing CD4+ T cells (Th17 cells) have recently been described as an important effector cell in host anti-Candida resistance. In this study, therefore, we tried to induce Th17 cells in cultures of severely burned patient PBMC by stimulation with the C. albicans Ag (CAg). In the results, the biomarkers for Th17 cells (IL-17 production and intracellular expression of IL-17 and retinoic acid receptor-related orphan receptor γt) were not displayed by burn patient PBMC stimulated with CAg, whereas these biomarkers of Th17 cells were detected in cultures of healthy donor PBMC stimulated with CAg. Burn patient sera were shown to be inhibitory on CAg-stimulated Th17 cell generation in healthy donor PBMC cultures; however, Th17 cells were induced by CAg in healthy donor PBMC cultures supplemented with burn patient sera that were previously treated with anti–IL-10 mAb. Also, the biomarkers of Th17 cells were not induced by CAg in healthy donor PBMC cultures supplemented with rIL-10. IL-10 was detected in serum specimens derived from severely burned patients. These results indicate that Th17 cells are not generated in burn patient PBMC cultures supplemented with CAg. IL-10, produced in response to burn injuries, is shown to be inhibitory on Th17 cell generation. The high susceptibility of severely burned patients to C. albicans infection might be influenced if burn-associated IL-10 production is intervened.
Allogeneic HLA-A*02–Restricted WT1-Specific T Cells from Mismatched Donors Are Highly Reactive but Show Off-Target Promiscuity
Authors: Falkenburg Willem J. J. , Melenhorst J. Joseph , van de Meent Marian , Kester Michel G. D. , Hombrink Pleun , Heemskerk Mirjam H. M. , Hagedoorn Renate S. , Gostick Emma , Price David A. , Falkenburg J. H. Frederik , Barrett A. John , Jedema Inge 
Published: August 2011

Abstract
T cells recognizing tumor-associated Ags such as Wilms tumor protein (WT1) are thought to exert potent antitumor reactivity. However, no consistent high-avidity T cell responses have been demonstrated in vaccination studies with WT1 as target in cancer immunotherapy. The aim of this study was to investigate the possible role of negative thymic selection on the avidity and specificity of T cells directed against self-antigens. T cell clones directed against the HLA-A*0201–binding WT1126–134 peptide were generated from both HLA-A*02–positive (self-HLA–restricted) and HLA-A*02–negative [nonself (allogeneic) HLA [allo-HLA]-restricted] individuals by direct ex vivo isolation using tetramers or after in vitro priming and selection. The functional avidity and specificity of these T cell clones was analyzed in-depth. Self-HLA–restricted WT1-specific clones only recognized WT1126–134 with low avidities. In contrast, allo-HLA–restricted WT1 clones exhibited profound functional reactivity against a multitude of HLA-A*02–positive targets, even in the absence of exogenously loaded WT1 peptide, indicative of Ag-binding promiscuity. To characterize this potential promiscuity, reactivity of the T cell clones against 400 randomly selected HLA-A*0201–binding peptides was investigated. The self-HLA–restricted WT1-specific T cell clones only recognized the WT1 peptide. In contrast, the allo-HLA–restricted WT1-reactive clones recognized besides WT1 various other HLA-A*0201–binding peptides. In conclusion, allogeneic HLA-A*02–restricted WT1-specific T cells isolated from mismatched donors may be more tumor-reactive than their autologous counterparts but can show specific off-target promiscuity of potential clinical importance. As a result of this, administration of WT1-specific T cells generated from HLA-mismatched donors should be performed with appropriate precautions against potential off-target effects.
A Series of Energy‐Transfer Copolymers Derived from Fluorene and 4,7‐Dithienylbenzotriazole for High Efficiency Yellow, Orange, and White Light‐Emitting Diodes
Authors: Zhang Lianjie , Hu Sujun , Chen Junwu , Chen Zhenhui , Wu Hongbin , Peng Junbiao , Cao Yong 
Published: August 2011

AbstractEight random and alternating copolymers PF‐DTBTA derived from 2,7‐fluorene and 4,7‐dithienylbenzotriazole (DTBTA) were synthesized. Thin solid films of the energy‐transfer copolymers possess high absolute photoluminescence (PL) quantum yields (ΦPL) between 60−72%. Inserting PVK layer between anode and emissive layer could show higher electroluminescence (EL) performances due to PVK‐enhanced hole injection. Random copolymers PF‐DTBTA1−15, with DTBTA molar contents from 1% to 15%, displayed yellow EL spectra with high external quantum efficiency (EQEmax) up to 5.78%. PF‐DTBTA50, the alternating copolymer, showed an orange EL with EQEmax of 3.3%. The good ΦPL and EQEmax of the PF‐DTBTA50 with very high DTBTA content indicate that DTBTA is a high efficiency chromophore with very low concentration quenching effects in the solid state PL and EL processes. PF‐DTBTA0.03−0.1 could emit white EL due to partial energy transfer from fluorene segments to DTBTA units. Moreover, white EL devices, with forward‐viewing maximum luminous efficiency up to 11 cd/A and stable white EL spectra (CIE coordinates of (0.33, 0.43)) in high current range from 5 mA to 60 mA, could be realized from the non‐doped polymer with simple binary structure. Our results suggest that DTBTA has big potential to construct high performanced EL polymers or oligomers.
Evolving role of biomarkers in acute cerebrovascular disease
Authors: Kernagis Dawn N. , Laskowitz Daniel T. 
Published: August 2011

AbstractThe development of a clinically validated biomarker of acute cerebral ischemia would have the potential to facilitate the use of time‐sensitive reperfusion strategies, allow for individualization of patient care by predicting relative risk of hemorrhage and volume of penumbral tissue, and add valuable prognostic information for patients presenting with acute stroke. Additionally, a stroke biomarker might benefit early stage clinical research by serving as a surrogate measure of ischemic injury. Although at present there are no clinically validated biomarkers of acute stroke, previous studies have focused on markers associated with different components of the ischemic cascade, including microglial activation, inflammation, oxidative stress, neuronal injury, hemostasis, and endothelial dysfunction. Evolving technologies have provided high throughput approaches to investigate potential gene and protein signatures, and methods to measure newly discovered markers of cell death and immune responses. Prior to defining the clinical utility of stroke biomarkers, it is critical to understand the inherent limitations of a biomarker‐based approach and define its potential value for providing adjunctive diagnostic and prognostic information. The identification and validation of a clinically relevant biomarker, or panel of markers, of stroke will ultimately require incorporation of both stringent research design and assessment in the clinical context in which the marker will be used. Ann Neurol 2012;
Insights into large‐scale cell‐culture reactors: I. Liquid mixing and oxygen supply
Authors: Sieblist Christian , Jenzsch Marco , Pohlscheidt Michael , Lübbert Andreas 
Published: August 2011

AbstractIn the pharmaceutical industry, it is state of the art to produce recombinant proteins and antibodies with animal‐cell cultures using bioreactors with volumes of up to 20 m3. Recent guidelines and position papers for the industry by the US FDA and the European Medicines Agency stress the necessity of mechanistic insights into large‐scale bioreactors. A detailed mechanistic view of their practically relevant subsystems is required as well as their mutual interactions, i.e., mixing or homogenization of the culture broth and sufficient mass and heat transfer. In large‐scale bioreactors for animal‐cell cultures, different agitation systems are employed. Here, we discuss details of the flows induced in stirred tank reactors relevant for animal‐cell cultures. In addition, solutions of the governing fluid dynamic equations obtained with the so‐called computational fluid dynamics are presented. Experimental data obtained with improved measurement techniques are shown. The results are compared to previous studies and it is found that they support current hypotheses or models. Progress in improving insights requires continuous interactions between more accurate measurements and physical models. The paper aims at promoting the basic mechanistic understanding of transport phenomena that are crucial for large‐scale animal‐cell culture reactors.
Insights into large‐scale cell‐culture reactors: II. Gas‐phase mixing and CO2 stripping
Authors: Sieblist Christian , Hägeholz Oliver , Aehle Mathias , Jenzsch Marco , Pohlscheidt Michael , Lübbert Andreas 
Published: August 2011

AbstractMost discussions about stirred tank bioreactors for cell cultures focus on liquid‐phase motions and neglect the importance of the gas phase for mixing, power input and especially CO2 stripping. Particularly in large production reactors, CO2 removal from the culture is known to be a major problem. Here, we show that stripping is mainly affected by the change of the gas composition during the movement of the gas phase through the bioreactor from the sparger system towards the headspace. A mathematical model for CO2‐stripping and O2‐mass transfer is presented taking gas‐residence times into account. The gas phase is not moving through the reactor in form of a plug flow as often assumed. The model is validated by measurement data. Further measurement results are presented that show how the gas is partly recirculated by the impellers, thus increasing the gas‐residence time. The gas‐residence times can be measured easily with stimulus‐response techniques. The results offer further insights on the gas‐residence time distributions in stirred tank reactors.
Gaze and viewing angle influence visual stabilization of upright posture
Authors: Ustinova K.I. , Perkins J. 
Published: August 2011

AbstractFocusing gaze on a target helps stabilize upright posture. We investigated how this visual stabilization can be affected by observing a target presented under different gaze and viewing angles. In a series of 10‐second trials, participants (N= 20, 29.3 ± 9 years of age) stood on a force plate and fixed their gaze on a figure presented on a screen at a distance of 1 m. The figure changed position (gaze angle: eye level (0°), 25° up or down), vertical body orientation (viewing angle: at eye level but rotated 25° as if leaning toward or away from the participant), or both (gaze and viewing angle: 25° up or down with the rotation equivalent of a natural visual perspective). Amplitude of participants’ sagittal displacement, surface area, and angular position of the center of gravity (COG) were compared. Results showed decreased COG velocity and amplitude for up and down gaze angles. Changes in viewing angles resulted in altered body alignment and increased amplitude of COG displacement. No significant changes in postural stability were observed when both gaze and viewing angles were altered. Results suggest that both the gaze angle and viewing perspective may be essential variables of the visuomotor system modulating postural responses.