bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water-soluble copolymers of 2-methacryloyloxyethyl phosphate: Synthesis and properties
Authors: Annenkov Vadim V. , Pal'shin Victor A. , Danilovtseva Elena N. 
Published: August 2014

AbstractNew water-soluble polymers with phosphate groups based on 2- methacryloyloxyethyl phosphate have been synthesized by copolymerization with 1-vinyl-2-pyrrolidone and 1-vinylimidazole. The obtained copolymers are polyelectrolytes showing high inclination to aggregation in aqueous medium according to light scattering data. Copolymer of 1-vinylimidazole shows ampholyte properties with isoelectric point at pH 6.8 (6.4 in 0.1M NaCl). Condensation of silicic acid in the presence of this copolymer results in composite particles containing aggregated or non-aggregated copolymer coils with embedded silica.
A review on modeling of the thermal conductivity of polymeric nanocomposites
Authors: Jafari Nejad Sh. Jafari 
Published: August 2014

AbstractThis review reports recent advances in the field of thermal conductivity of polymeric nanocomposites. Thermally conductive polymeric nanocomposites can be used for replacing metal parts in several applications, such as liquid cooling and ventilation garment, power electronics, electric motors and generators, heat exchangers, etc., because the polymers have some privileges such as light weight, corrosion resistance, lower manufacturing cost and ease of processing. In this study, the thermal conductivity measurement and modeling of polymeric nanocomposites are discussed in general, and detailed examples are also drawn from the scientific literature. Many theoretical models are available to predict the thermal conductivity of nanocomposites. The simplest of these are mixture rules such as series, parallel, and geometric models. However, the series model typically over predicts the thermal conductivity, whereas the parallel model tends to under predict the thermal conductivity of the nanocomposites. Other models such as the Hamilton-Crosser model and the Lewis-Nielsen model are based on particle size, geometry, and the manner of particle packing in the matrix. Also, there are various effective medium approaches (EMA) like the Maxwell-Garnett (MG) approximation to analyze the thermal transport behaviour in heterogeneous media such as thermal conductivity of some composite structures.
Dissolution of natural polymers in ionic liquids: A review
Authors: Meng Zhuojun , Zheng Xuejing , Tang Keyong , Liu Jie , Qin Shufa 
Published: August 2014

AbstractNatural polymers are produced by living organisms, e.g. plants, animals, microorganisms. Natural polymer materials have gained increasing attention due to their high strength and stiffness combined with carbon neutral, biocompatibility, biodegradability, renewability and sustainability. However, due to the strong interand intra-molecular hydrogen bonds, many natural polymers are extremely difficult to be dissolved in water or traditional organic solvents. The processing difficulties tremendously limit the applications of natural polymers in many fields. Recently, using ionic liquids (ILs) as novel solvents to dissolve natural polymers has attracted increasing attention. ILs has been shown to be highly effective at dissolving some natural polymers to technically useful concentrations. In this article, the structure and basic properties of ILs are introduced; the recent progress is reviewed in the dissolution of several important natural polymers using ionic liquids, including cellulose, chitin and chitosan, wool keratin fibers, silk fibroin and collagen fibers. The dissolution mechanisms of natural polymers using ILs as solvents are analyzed. The structure and properties of native and regenerated natural polymers are discussed in details.
Synthesis and characterization of high molecular weight and low dispersity polystyrene homopolymers by RAFT polymerization
Authors: Jin Cheng , Liu Chun , Jiang Bo , in Qin-jian 
Published: August 2014

AbstractHigh molecular weight polystyrene homopolymers with low dispersity were synthesized by a reversible addition-fragmentation chain transfer (RAFT) polymerization method using 0.03 and 0.3 wt% of cumyl dithiobenzoate (CDB) vs. styrene (St) and the azobis(isobutyronitrile) initiator, at the polymerization temperature of 60 or 70 °C. The optimal high molecular weight polystyrene via this synthetic scheme shows Mw = 46.5×104, Mn = 33.3×104, and a dispersity of 1.40. The polystyrene chain contains a dithiobenzoate C=S moiety and thus can be used as a macro-chain-transfer agent for the polymerization of other monomers and for the synthesis of diversified block copolymers under mild conditions. The changes of the polystyrene molecular weight and dispersity were studied by the influences of the initial concentration ratio of CDB to styrene ([CDB]0/[St]0), the polymerization temperature, and the polymerization time. The PS molecular weight is inversely proportional to the [CDB]0/[St]0 ratio. Decreasing CDB from 0.3 to 0.03 wt%, a high MW PS was obtained, while the dispersity was observed to increase from 1.10 to 1.40. The PS molecular weight increases with the increase of the reaction time, while the dispersity of PS varies little from 1.12 to 1.23. The molecular weight and dispersity increase with the increase of the polymerization temperature. As the temperature arises from 60°C to 70°C, the conversion increases considerably from 25.8% to 39.9%, and the dispersity increases slightly from 1.15 to 1.17. As the temperature reaches 80°C, the conversion increases considerably to 64.7%, and the dispersity increases to 1.53. The polymer molecular weight of the polystyrene prepared by the RAFT method is suitable for the applications of engineering materials.
Synthesis of new photobactericidal polymers by “click chemistry” and a study of their biological activity
Authors: Memmi Abdelmajid , Granet Robert , Aouni Mahjoub , Bakhrouf Amina , Krausz Pierre 
Published: August 2014

AbstractPhotobactericidal plastic materials have been synthesized from cellulose and natural or synthetic porphyrins. The photosensitizer was covalently linked to a cellulose fatty ester by means of a Huisgen cyclo addition reaction resulting in high yields and degrees of substitution (DS). The polymers obtained were characterized by UV vis., IR and 1H NMR spectroscopy. Photobactericidal properties were evaluated on the three pathogenic strains E. coli, S. aureus and P. aeruginosa. A total killing of the bacteria was achieved with plastics with DS values higher than 1% upon illumination.
Contact angle hysteresis on plasma treated polyethylene terephthalate
Authors: Bachurová Marcela , Wiener Jakub 
Published: August 2014

AbstractKnowledge of contact angle hysteresis is important to the understanding of surface wettability and to controlling further surface wetting behaviour. The wettability can be affected by surface modification. This study is a look on surfaces modified by the usage of plasma. We describe the effect of plasma treatments on contact angle hysteresis by the use of Diffuse Coplanar Surface Dielectric Barrier Discharge (DCSBD). Modification of the surface was achieved using textile made from polyethylene terephthalate (PET). Results have shown that both advancing and receding contact angle were significantly reduced by the process. The contact angle hysteresis was decreased after the plasma treatment as was observed by measurement taken at various time intervals and this fact correspond with introduction of functional groups detected by X - ray photoelectron spectroscopy (XPS).
Synthesis and characterization of polymethylsilsesqui oxane microspheres by the two-step sol-gel method
Authors: Wang Jiangbo , Xin Zhong 
Published: August 2014

AbstractPolymethylsilsesquioxane (PMSQ) microspheres with an average diameter of 30nm to 6μm were prepared from methyltrimethoxysilane (MTMS) by a two-step sol-gel method in the presence of hexadecyl trimethyl ammonium chloride (HTAC). The reaction conditions including the concentration of HTAC, water/MTMS ratio, pH value and the temperature in condensation reaction were examined, and aggregation of the microspheres was not observed during the preparation process. Moreover, the structure and thermal stability of PMSQ microspheres were investigated by FT-IR, XRD, TGA, and so on.
Optimization of 4-vinylpyridine nitroxide mediated controlled radical polymerization: Effect of initiator protection and complexation with C60
Authors: Lessard Benoît H. , Marić Milan 
Published: August 2014

AbstractNitroxide mediated polymerization (NMP) of 4-vinylpyridine (4VP) using 2-([tert-butyl[1-(diethoxyphosphoryl)-2,2-dimethylpropyl]amino]oxy)-2-methyl pro pionic acid (BlocBuilder)-derived initiators was studied. Controlled homo polymerization of 4VP using 10 mol% [tert-butyl[1-(diethoxyphosphoryl)-2,2- dimethylpropyl]amino] nitroxide (SG1) relative to BlocBuilder was limited to low conversions (X = 0.20-0.30) due to interaction between the pyridine group of 4VP and BlocBuilder’s carboxylic acid group. Converting BlocBuilder into a succinimidyl ester terminated form (NHS-BlocBuilder) resulted in 4VP polymerizations with a linear increase in number average molecular weight, M̅n, versus X to X = 0.80, while maintaining a narrow molecular weight distribution ( M̅w/M̅n<1.2). Final poly(4VP) samples were determined to be pseudo-“living” by subsequent chain extension with a fresh batch of 4VP, with very few dead chains. Attempts to homopolymerize 4VP in the presence of as little as 0.04 wt% C60 relative to 4VP resulted in inhibition, preventing the polymerization from exceeding beyond X = 0.40 and thus 4VP/C60 complexation has to be done post-polymerization.
Functional flexible substrate in altering substitution phenylene core of fluorinated poly(arylene ether)s
Authors: Lee Chun-Che , Huang Wen-Yao 
Published: August 2014

AbstractWe proposed three degrees n” of phenyl substition on the middle phenylene core of novel poly(arylene ether)s (PAEs). The PAEs were prepared via nucleophilic displacement of fluorine atoms on the terminal benzene ring with trifluoromethylactivated bisfluoro monomer. The thermal property of polymers showed ~273 °C glass transition point and ~457 °C decomposition temperature for 5% weight loss. In addition, investigations revealed that spiro-annulated textures resulted from multisubstituted phetaphenylene moiety and trifluoromethyl groups. Furthermore, PAE films were experimentally demonstrated to have wide-range solubility, high transparencies greater than 90% in visible light region, low coefficient of thermal expansion about 30 ppm/°C, low polarities below 2.8 at 1 kHz, and hydrophobicities
Surface characterization of polymer foils
Authors: Kolská Zdenka , Řezníčková Alena , Švorčík Václav 
Published: August 2014

AbstractElectrokinetic potential (zeta potential) for selected 21 polymer foils was studied. The results on zeta potential are supplemented with contact angle measurements (goniometry) and with the results on surface roughness measured by atomic force microscopy (AFM). Zeta potential was determined using two approaches: streaming current and streaming potential at pH=6.0-6.2. Two electrolyte solutions with KCl (concentrations 0.001 and 0.005 mol/dm3) and KNO3 (0.001 mol/dm3) were used in the experiments. Zeta potential was shown to depend on surface chemistry, polarity, roughness and morphology of the polymer foils.
The properties, morphology and structure of BPDA/ PPD/ BOA polyimide fibers
Authors: Huang Senbiao , Gao Zhongmin , Ma Xiaoye , Qiu Xuepeng , Gao Lianxun 
Published: August 2014

AbstractA family of random copoly(amic acid)s (coPAAs) containing the 2-(4- aminophenyl)-5-aminobenzoxazole (BOA) moiety were synthesized in DMAc, followed by dry-jet wet spinning process into as-spun PAA fibers. The modified polyimide (PI) fibers were obtained from PAA fibers after imidized and drawn in a furnace. The mechanical properties of fibers were improved by incorporating BOA into BPDA/PPD backbone. SEM photo showed that the cross-section of each stage fibers was round and voids free. Besides, the “skin-core” and microfibrillar structure were not observed. The thermal properties of PI fibers were also investigated. The results showed that the PI fibers owned excellent thermal stability, moreover, the dimensional stability and the microphase separation of fibers were improved by heat-drawn stage. The Tg were found to be around 290°C by TMA and DMA. The X-ray (WAXD and SAXS) experiments indicated that the longitudinal stacks, the molecular orientation and the structural homogeneity of PI fiber were improved in the preparation process of fibers.
Evaluation of potential antiamnesic activities of aqueous extract of Vitex trifolia leaves against scopolamine induced amnesia and in normal rats
Authors: Mohanbabu Amberkar Vittal Rao , Kishore Meena Kumari Kamal , Chandrashekar Bangalore Revanna , Pradeepa Hoskeri Dakappa , Christopher Rockson , Nandit Purnanand Banawalikar 
Published: August 2014

Abstract

Background: The goal of this study was to evaluate the cerebroprotective and cognition-enhancing activities of the aqueous Vitex trifolia (Vt) L. (Verbenaceae) leaf extract against scopolamine-induced amnesia and in normal rats.

Methods: Reference or working memory and long-term memory in rodents were tested by experimental paradigms like passive avoidance (PA) and T-maze (TM), respectively. TM and Morris water maze (MWM) were used to screen putative spatial or localization task and the navigation memory-enhancing activities of Vt extract, respectively. In both the PA and TM models, scopolamine (0.5 mg/kg, intraperitoneal, 30 min prior to the trial) was used to induce amnesia, and donepezil (3 mg/kg/day for 15 days) was used as a standard antiamnesic drug. In MWM, two doses of Vt extract were tested against normal control rats. The aqueous Vt extract was prepared as a suspension in 0.5% carboxymethyl cellulose and administered orally at two doses (10 and 20 mg/kg/day) for 15 days to the respective group of rats.

Results: The higher dose (20 mg/kg) of plant extract exhibited significant (p<0.01) antiamnesic activity in the PA and TM models vs. the control. In the MWM test, at probe trial, Vt extract 20 mg/kg showed the least escape latency time, which was statistically significant (p<0.01) and exhibited maximum percentage of time spent in the probe quadrant by 60.75%.

Conclusions: These results partly substantiate the traditional use of Vt leaves for improvement of cognition, indicating that daily administration of Vt leaves differentially could modulate short- and long-term learning and memory in rats probably through its battery of anticholinesterase, procholinergic, anti-inflammatory, antioxidant, and neuroprotective activities.
Definitions of radioisotope thick target yields
Authors: Otuka Naohiko , Takács Sandor 
Published: August 2014

Abstract
Definitions of thick target yields are reviewed
in relation to their documentation for the experimental nuclear
reaction data library (database).
Researchers reporting experimental thick target yields are urged
to define their yields clearly with an appropriate unit in order to compile
them in the experimental data library (EXFOR) in a consistent manner,
and also to properly utilise them for comparison with other
experimental and evaluated yields.
Measurement of yield of residues produced in 12C+natY reaction and subsequent separation of 97Ru
from Y target using cation exchange resin
Authors: Maiti Moumita , Lahiri Susanta 
Published: August 2014

Abstract
This paper reports the yield of no-carrier-added (NCA) radionuclides produced in 12C6+ induced reaction on
natural yttrium target at 10 different incident energies in the range of 40 to 75 MeV by the stacked-foil
technique, followed by off-line γ-ray spectroscopy. It also reports the radiochemical separation of NCA 97Ru
from the bulk yttrium target. 97Ru was produced in the yttrium matrix through
89Y(12C, 4n)97,97mRh(EC)97Ru and
89Y(12C, p3n)97Ru reactions along with the radioisotopes 98Rh,
97Rh, 97mRh, 93Tc, 94Tc, 95Tc and
93mMo. Irradiated target was allowed to cool for the complete decay of short-lived residues and
97Ru was then separated from the bulk yttrium using the cation exchanger DOWEX-50WX4 in an ion exchange column as
well as via solid-liquid extraction (SLX). A total of ∼88% NCA 97Ru was separated in column
chromatography without any contamination of bulk, whereas quantitative separation of NCA Ru was achieved in SLX.
Preparation and characterization of graphite/resin composite bipolar plates for polymer electrolyte membrane fuel cells
Authors: Chen Hui , Xia Xiao-Hong , Yang Li , He Yue-de , Liu Hong-bo 
Published: August 2014

Abstract
Preparing conductive composite bipolar plates for fuel cells by compression molding is a promising research direction. The very key point is how to choose the conductivity filler and binder to meet the requirement. In this article, natural graphite and expanded graphite were used as the filler, and phenolic resin and epoxy resin were used as the binder. The composite bipolar plates were prepared by solution intercalation mixing, compression molding, and curing. The variations in electrical conductivity and mechanical properties were evaluated with the resin content. The results show that the types of fillers and binders have significant effects on the performance of composite bipolar plates, and that the thermal stability of all composite bipolar plates is very good at the fuel-cell working temperature. The corrosion current densities were <16 μA/cm2, which indicates that the composites developed in this work meet many attributes of bipolar plates for use in polymer electrolyte membrane fuel cells.
Durability study of ramie fiber fabric reinforced phenolic plates under humidity conditions
Authors: Xian Guijun , Yin Peng , Kafodya Innocent , Li Hui , Wang Wei-lun 
Published: August 2014

Abstract
A durability study of a ramie fiber fabric reinforced phenolic resin (RFRP) plate under 50%, 85%, and 98% relative humidity for 6 months at room temperature was performed. Water absorption and desorption, tensile and short beam shear strengths of the RFRP plates were investigated as a function of exposure time. RFRP samples show strong hydrophilic characteristics and the saturated water content varies from 0.73% to 4.5% with relative humidity ranging from 50% to 98%. After 6 months of exposure to 98% relative humidity, an abnormal extra amount of moisture was absorbed, which may have resulted from cracks in the resin matrix or from debonding between fiber and resin due to swelling of the fibers with high moisture content. It was found that the tensile modulus is more susceptible to moisture uptake, which is ascribed to the degradation of ramie fibers with the water ingress. An approximate linearity between the mechanical properties and the moisture content is observed if the abnormal extra water uptake is neglected. Both tensile and short beam shear strengths of the RFRP samples recovered remarkably when samples were fully dried at 60°C, indicating a low degree of permanent degradation occurred due to the exposure.
Dialogizität und sequenzielle Verdichtung in der Forenkommunikation: Editieren als kommunikatives Verfahren
Authors: Lindemann Katrin , Ruoss Emanuel , Weinzinger Caroline 
Published: August 2014

Abstract
Drawing both on conversation analysis and text linguistics, this article retraces the emergence of a new communicative practice in an online discussion forum: Based on data from an academic learning environment, we demonstrate how peers in a student study group start using the “edit button” which allows them to modify in retrospect not only their own but also other people’s posts. This communicative practice of post editing in online discussion forums develops in four stages: It starts out as simple postings of messages on a discussion board. Next, the collocutors make use of the edit button to change their own posts, and, in a dialogical manner that of their discussion partners. Finally, it comes down to a complex form of exchange between the interlocutors who innovatively use the edit button within a single post. By using the edit button in innovative ways the participants bring together sequentially related messages in a single post that are usually spread over multiple posts. We argue that the emergence of this innovative use of the strategy of “sequential compression” (sequenzielle Verdichtung), as we shall call it, may be understood as an answer both to the affordances of asynchronous communication in discussion forums and to the learning situation which is characterized by pressure of time calling for new and innovative strategies.
“Big Data” and the Electronic Health Record
Authors: Ross M. K. , Wei Wei , Ohno-Machado L. 
Published: August 2014

Summary
Objectives: Implementation of Electronic Health Record (EHR) systems continues to expand. The massive number of patient encounters results in high amounts of stored data. Transforming clinical data into knowledge to improve patient care has been the goal of biomedical informatics professionals for many decades, and this work is now increasingly recognized outside our field. In reviewing the literature for the past three years, we focus on “big data” in the context of EHR systems and we report on some examples of how secondary use of data has been put into practice.
Methods: We searched PubMed database for articles from January 1, 2011 to November 1, 2013. We initiated the search with keywords related to “big data” and EHR. We identified relevant articles and additional keywords from the retrieved articles were added. Based on the new keywords, more articles were retrieved and we manually narrowed down the set utilizing predefined inclusion and exclusion criteria.
Results: Our final review includes articles categorized into the themes of data mining (pharmacovigilance, phenotyping, natural language processing), data application and integration (clinical decision support, personal monitoring, social media), and privacy and security.
Conclusion: The increasing adoption of EHR systems worldwide makes it possible to capture large amounts of clinical data. There is an increasing number of articles addressing the theme of “big data”, and the concepts associated with these articles vary. The next step is to transform healthcare big data into actionable knowledge.
Big Data: Are Biomedical and Health Informatics Training Programs Ready?
Authors: Hersh W. , Jai Ganesh A. U. , Otero P. 
Published: August 2014

Summary
Objective: The growing volume and diversity of health and biomedical data indicate that the era of Big Data has arrived for healthcare. This has many implications for informatics, not only in terms of implementing and evaluating information systems, but also for the work and training of informatics researchers and professionals. This article addresses the question: What do biomedical and health informaticians working in analytics and Big Data need to know?
Methods: We hypothesize a set of skills that we hope will be discussed among academic and other informaticians.
Results: The set of skills includes: Programming - especially with data-oriented tools, such as SQL and statistical programming languages; Statistics - working knowledge to apply tools and techniques; Domain knowledge - depending on one’s area of work, bioscience or health care; and Communication - being able to understand needs of people and organizations, and articulate results back to them.
Conclusion: Biomedical and health informatics educational programs must introduce concepts of analytics, Big Data, and the underlying skills to use and apply them into their curricula. The development of new coursework should focus on those who will become experts, with training aiming to provide skills in “deep analytical talent” as well as those who need knowledge to support such individuals.