bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface oxidation of low‐density polyethylene films to improve their susceptibility toward environmental degradation
Authors: Roy P. K. , Surekha P. , Rajagopal C. 
Published: June 2011

AbstractPolyethylene wastes, particularly as films, have accumulated over the last several decades resulting in a major visual litter problem. The aim of this study was to investigate the ability of chemical reagents to oxidize the low‐density polyethylene (LDPE) film surface to increase their susceptibility toward photodegradation and thermal degradation. Three chemical agents, namely, potassium permanganate, potassium persulfate, and benzoyl peroxide, were used to oxidize the film surface to generate chromophoric groups, such as carbonyl groups, which are the main reason for the enhanced environmental degradation of photolytic polymers, such as ethylene–carbon monoxide and ethylene–vinyl ketone copolymers. For the chemical treatment, LDPE films of 70 ± 5 μm thickness were prepared by a film‐blowing technique and subsequently reacted with the aforementioned oxidizing agents. To aid the oxidation process, the reaction with potassium persulfate and potassium permanganate was performed under microwave irradiation heating. In the case of benzoyl peroxide aided oxidation, the films were subjected to repeated coating–heating treatments up to a maximum of 10 cycles. The treated films were subjected to accelerated aging, that is, xenon‐arc weathering and air‐oven aging (at 70°C), for extended time periods. The chemical and physical changes induced as a result of aging were followed by the monitoring of changes in the mechanical, structural, and thermal properties. The results indicate that the surface‐oxidized LDPE films exhibited enhanced susceptibility toward degradation; however, the extent was reduced as compared to photolytic or other degradable compositions. The ability of the chemicals to initiate degradation followed the order potassium persulfate < potassium permanganate < benzoyl peroxide. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Improvement in impact‐, tensile‐, and dynamic properties of injection molded wheat‐pulp‐polypropylene composites through fiber finishing
Authors: Sykacek Eva , Grzeskowiak Bogdan , Edlhofer Gerwig , Mundigler Norbert 
Published: June 2011

AbstractThis study was focused on the improvement of mechanical properties of injection molded wheat‐pulp polypropylene (PP) composites through fiber surface modifications. Ten different sizing and finishing agents, including fats, starch derivatives, and polysiloxanes were used as surfactants for the cellulosic pulp. As a result of polydimethylsiloxane treatment (0.3 wt %), impact strength was increased by 85%, tensile strength by 23%, and an augmentation in tensile modulus of 12% was also achieved. In consideration of the dynamic mechanical properties, the stronger effects of the modifiers on the storage‐ modulus were observed with increasing temperature. A new approach quantifying the extent of the dispersion of the pulp fibers using image analysis through transmission light micrographs was tested. The enhancement of tensile strength, tensile modulus, and impact strength could be attributed to the improved dispersion of the cellulosic fibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A compatibilized composite of recycled polypropylene filled with cellulosic fiber from recycled corrugated paper board: Mechanical properties, morphology, and thermal behavior
Authors: Lin Zhidan , Chen Chao , Guan Zixian , Tan Shaozao , Zhang Xiuju 
Published: June 2011

AbstractThis article deals with the feasibility of using recycled corrugated paper board (rPF) as the reinforcing material for recycled plastics. The composites of recycled polypropylene (rPP) and rPF were prepared by extrusion compounding and injection molding, and the rPP/rPF composites compatibilized by maleic anhydride grafted PP (PP‐g‐MA), maleic anhydride grafted ethylene‐1‐octene copolymer (POE‐g‐MA), and maleic anhydride grafted styrene‐ethylene‐butylene‐styrene copolymer (SEBS‐g‐MA) were also prepared. The crystallization and melting behavior, mechanical properties, thermal stability, and morphology of these composites were studied. The results indicated that rPF promoted the crystallization, enhanced the strength and toughness of rPP/rPF composites to some extent while decreased thermal stability at the same time. PP‐g‐MA and POE‐g‐MA improved the dispersion and interface adhesion of rPF, and further upgraded the mechanical properties and vicat softening temperatures. Among these compatibilizers, PP‐g‐MA was most favorable to the strength improvement while POE‐g‐MA was most favorable to the toughness improvement. As for SEBS‐g‐MA, it had no obvious modification effect. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
FT‐IR studies on the curing behavior of polycardanol from naturally renewable resources
Authors: Zhou Qun , Cho Donghwan , Ho Park Won , Keun Song Bong , Kim Hyun‐Joong 
Published: June 2011

AbstractIn the present study, the curing behavior of polycardanol prepared by enzymatic oxidative polymerization of thermally treated cashew nut shell liquid, which can be available from naturally renewable resources, was explored in the presence of methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate (Co‐Naph). The curing behavior was monitored varying Co‐Naph concentration and curing temperature by means of Fourier transform infrared (FT‐IR) spectroscopy. The result revealed that the characteristic absorption bands were significantly affected by the given curing condition, resulting mainly from the unsaturated moiety in the polycardanol molecule. The extent of curing of polycardanol strongly depended on curing temperature, showing a typically sigmoidal curve reaching almost 1.0 upon processing at 200°C for 120 min. The thermal curing conditions for preparing polycardanol with an optimal state of cure were provided in the work. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Novel sulfur—containing benzophenone derivative as radical photoinitiator for photopolymerization
Authors: Pietrzak Marek , Wrzyszczyński Andrzej 
Published: June 2011

AbstractA novel, highly efficient, polymerizable sulfur‐containing photoinitiator for free radical polymerization, benzophenone thio‐acetic acid (BP‐S‐CH2‐COOH) was synthesized, characterized, and compared to photoinitiator parameters of the benzophenone (BP) and benzophenone/(phenylthio)acetic acid couple. The photoinitiator possesses a greatly redshifted UV maximal absorption in comparison to BP. Laser flash photolysis studies suggest that photoinitiator radicals are generated by photocleavage of CS bond. Photopolymerization of 2‐ethyl‐2‐(hydroxymethyl)‐1,3‐propanediol triacrylate (TMPTA) demonstrated that one‐component system BPSCH2COOH is more efficient for polymerization than two‐component system. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Modeling of nonisothermal film blowing process for non‐Newtonian fluids by using variational principles
Authors: Kolarik Roman , Zatloukal Martin 
Published: June 2011

AbstractIn this work, nonisothermal film blowing process analysis for non‐Newtonian polymer melts has been performed theoretically by using minimum energy approach and the obtained predictions were compared with both, theoretical and experimental data (internal bubble pressure, take‐up force, bubble shape, velocity and temperature profiles) taken from the open literature. For this purpose, recently proposed generalized Newtonian model depending on three principal invariants of the deformation rate tensor, D, and its absolute defined as
$\sqrt {D \cdot D}$
has been used. It has been found that film blowing model predictions are in very good agreement with the corresponding experimental data. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Development of Embryonic Gill Vasculature in the Yellow Stingray, Urobatis Jamaicensis
Authors: Basten Bethany L. , Sherman Robin L. , Lametschwandtner Alois , Spieler Richard E. 
Published: June 2011

AbstractCorrosion casting was utilized to examine the development of gill vasculature in embryonic yellow stingrays, Urobatis jamaicensis (formerly Urolophus jamaicensis). The most marked changes in vascular configuration of the gills occur in the earliest castable stages of gestation. These changes included development of afferent external gill filament vessels and progression from paired dorsal aortae to a single fused dorsal aorta. Internal gill vasculature was found to nearly match that of an adult by the time the external gill filaments had fully regressed and yolk sac had been exhausted (>47 mm disc width). Examination of embryo casts also revealed characteristics of the branchial vasculature not previously reported in adult specimens. These include the presence of pre‐lamellar sphincters, intertrematic branches, afferent distributing arteries, which supply blood to many afferent filament arteries resulting in greater interconnection of the filaments, and observation that the afferent branchial artery in the first hemibranch supplies blood directly to afferent filament arteries on the dorsal half of this arch. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Volumetric Analysis of the African Elephant Ventricular System
Authors: Maskeo Busisiwe C. , Spocter Muhammed A. , Haagensen Mark , Manger Paul R. 
Published: June 2011

AbstractThis study used magnetic resonance imaging (MRI) to determine the volume of the ventricular system in the brain of three adult male African elephants (Loxodonta africana). The ventricular system of the elephant has a volume of ∼240 mL, an order of magnitude larger than that seen in the adult human. Despite this large size, allometric analysis indicates that the volume of the ventricles in the elephant is what one would expect for a mammal with an ∼5 kg brain. Interestingly, our comparison with other mammals revealed that primates appear to have small relative ventricular volumes, and that megachiropterans and microchiropterans follow different scaling rules when comparing ventricular volume to brain mass indicating separate phylogenetic histories. The current study provides context for one aspect of the elephant brain in the broader picture of mammalian brain evolution. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Expression of Mortalin Detected in Human Liver Cancer by Tissue Microarrays
Authors: Chen Xi , Xu Bo , Li Hongyan , Yang Ling , Zuo Ji , Liu Wen , Liu Chenghai 
Published: June 2011

AbstractMortalin is a highly conserved molecular chaperone in the heat shock protein (HSP) 70 family, which plays a role in carcinogenesis. The relationship between tumors and the expression of Mortalin is not fully elucidated. In this study, human tumor specimens from various organs of liver cancer at different stages and cultured liver cancer cells were used to study the expression pattern of Mortalin. Through immunohistochemistry we showed that Mortalin was significantly higher in tumors than in adjacent benign tissues. Using liver tissue microarrays tested on hepatocellular carcinomas, Mortalin expression was consecutively higher with advanced tumor stages. Mortalin expression on the cultured liver cancer cells were characterized with immunocytochemistry, Real‐time PCR, and western blot. The results showed that the expression level is markedly higher in the SMMC 7721 (a liver‐derived tumor cell line) than in the HL 7702 (a normal liver cell line) in the protein level only. Understanding the role of Mortalin in tumors may lead to development of a new therapeutic target in cancer treatment. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Effects of Advanced Age on the Morphometry and Degenerative State of the Cervical Spine in a Rat Model
Authors: Laing Andrew C. , Cox Riley , Tetzlaff Wolfram , Oxland Thomas 
Published: June 2011

AbstractAging causes changes in the geometry of the human cervical spine that may influence the tissue response to applied loads. Rat models are often used to study spinal cord injuries (SCI) and have the potential to enhance our understanding of the effect of age on SCI. The goal of this study was to characterize the morphometry and degenerative state of the cervical spine in Fisher 344 rats, and to determine the influence of age on these variables. Fifteen rats were split into three age groups: young adult (3 months of age), aged (12–18 months) and geriatric (30 months). Following tissue harvest we used a μCT scanner to image the cervical and upper thoracic spine from each specimen. Analysis software was used to measure variables including canal pinch diameter (the most rostral point on the dorsal aspect of a vertebral body to the most caudal aspect of the lamina on the immediately rostral vertebra), vertebral canal depth, width, and area, vertebral body height, depth, width, and area, and intervertebral disc thickness. Orthopaedic surgeons used midsagittal images to rate the degenerative state of the intervertebral discs. For all measures except disc thickness there was a significant increase (mean (SD) = 15.0 (9.7)%) for the aged compared to young specimens (P < 0.05). There were significant differences between the aged and geriatric specimens for only vertebral body depth (P = 0.016) and area (P = 0.020). Intervertebral disc degeneration was significantly greater on the ventral aspect of the spinal column (P < 0.001), with a trend toward increased degeneration in the geriatric specimens (P = 0.069). The results suggest that age‐related morphometric differences may need to be accounted for in experimental aging models of SCI in rats. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Development and Expression of Amyloid‐β Peptide 42 in Retinal Ganglion Cells in Rats
Authors: Wang Jianqiang , Zhu Chunfang , Xu Yirong , Liu Bin , Wang Minchen , Wu Kaiyun 
Published: June 2011

AbstractThe previous studies have shown that Amyloid‐β peptide (Aβ) was mainly found in neurons of neurodegenerative diseases, such as Alzheimer's disease (AD) and glaucoma and little is known about its expression in normal nerve cells. The aim of the present study was to investigate the expression of amyloid‐β peptide 42 (Aβ‐42) in retinal ganglion cells of the postnatal rats. Rats were divided into seven experimental groups: 3, 6, 13, 15, 25, 60, and 90 days postnatal groups. Rats from 15 and 25 days postnatal groups were further divided into light‐exposure and non light‐exposure group. Cryosections or flat‐mounted retinas of rat eyes were used for testing Aβ‐42 by immunocytochemistry staining. Aβ‐42 expression was not observed in rats within 13 days after birth, but was easily detectable in all groups of rats over 15 days after birth. In addition, the expression of Aβ‐42 in retina was increasing as the rats got older, reached to highest level in 60 days after birth. Furthermore, the expression of Aβ‐42 was not detected in rats kept under dark indicating that light is required for the expression of Aβ‐42 in retina. This is the first report showing that normal retinal ganglion cells express Aβ‐42, and that the expression of Aβ‐42 in retinal ganglion cells requires the exposure to light. These data suggest that Aβ‐42 may play a important role in vision development. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Solution‐Processable n‐Type Organic Field‐Effect Transistor (OFET) Materials Based on Carbonyl‐Bridged Bithiazole and Dioxocyclopentene‐Annelated Thiophenes
Authors: Nitani Masashi , Ie Yutaka , Tada Hirokazu , Aso Yoshio 
Published: June 2011

AbstractA series of electronegative π‐conjugated compounds composed of carbonyl‐bridged bithiazole and alkyl‐substituted dioxocyclopenta[b]thiophene were synthesized as a candidate for solution‐processable n‐type organic semiconductor materials and characterized on the basis of photophysical and electrochemical properties. Cyclic voltammetry measurements showed that the first half‐wave reduction potentials of these compounds are between −0.97 and −1.14 V versus ferrocene/ferrocenium, which corresponds to lowest unoccupied molecular orbital energy levels between −3.83 and −3.66 eV. Thanks to hexyl or dodecyl groups in the molecules, the compounds are sufficiently soluble to realize the fabrication of their thin films through a spin‐coating method. As a result, the prepared organic field‐effect transistors based on these newly developed compounds exhibited n‐channel characteristics not only under vacuum but also in air, and the best field‐effect electron mobility observed under vacuum was 0.011 cm2 V−1 s−1 with an on/off ratio of 108 and a threshold voltage of 16 V.
Photoinduced Reversible Topographical Changes on Diarylethene Microcrystalline Surfaces with Biomimetic Wetting Properties
Authors: Nishikawa Naoki , Uyama Ayaka , Kamitanaka Takashi , Mayama Hiroyuki , Kojima Yuko , Yokojima Satoshi , Nakamura Shinichiro , Tsujii Kaoru , Uchida Kingo 
Published: June 2011

AbstractReversible topographical changes were observed on a photochromic diarylethene microcrystalline film surface by alternate irradiation with UV and visible light. Two types of surfaces were prepared from this film: 1) Storage of the film at 30 °C for 24 hours in the dark after UV irradiation afforded a surface that was covered with needle‐shaped crystals, whose diameter and length were approximately 1 μm and 10 μm, respectively, and showed a superhydrophobic lotus effect. 2) Storage of the film at 70 °C for 3 hours in the dark caused the needle‐shaped crystals to be converted into larger rod‐like crystals (5∼8 μm wide and 20∼30 μm long) by Ostwald ripening and a disappearance of the lotus effect. The obtained activation energy of the formation of the needle‐ and rod‐shaped crystals was 143 and 162 kJ mol−1, respectively. Subsequent UV irradiation to the surface, which was followed by storage at 50 °C for 1 hour in the dark, gave a doubly rough structure; small needle‐shaped crystals were formed between the larger rod‐shaped crystals. The surface showed both superhydrophobic properties and the pinned effect of the water droplet: the petal effect. Fractal analysis of both surfaces were carried out using a box‐counting method, and the lotus effect was observed in the presence of smaller‐sized crystals, whilst the petal effect was observed with larger sized crystals (ca. 100 μm). We demonstrated that the hydrophobic property was controlled by the distribution in crystal size of the closed‐ring isomer of the diarylethene. Visible‐light irradiation of both rough surfaces afforded surfaces with cubic‐shaped micro‐crystals of the open‐ring isomer.
Modeling and control of an airbrake electro‐hydraulic smart actuator
Authors: Rubagotti Matteo , Carminati Marco , Clemente Giampiero , Grassetti Riccardo , Ferrara Antonella 
Published: July 2011

AbstractIn this paper, an accurate model of an airbrake electro‐hydraulic smart actuator is obtained by physical considerations, and then different control strategies (variable‐gain proportional control, PT1 control with switching integrator, and second order sub‐optimal sliding mode control) are proposed and analyzed. This application is innovative in the avionic field, and is one of the first attempts to realize a fly‐by‐wire system for airbrakes, oriented to its immediate employment and installation on current aircraft. The project was carried on with the participation of the Italian Ministry of Defense, and was commissioned to MAG, a leading provider of integrated systems and aviation services for aerospace.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Serum inverts and improves the fluorescence response of an aptamer beacon to various vitamin D analytes
Authors: Bruno John G. , Carrillo Maria P. , Phillips Taylor , Edge Allison 
Published: June 2011

ABSTRACTA dominant aptamer loop structure from a library of nearly 100 candidate aptamer sequences developed against immobilized 25‐hydroxyvitamin D3 (calcidiol) was converted into a 5′‐TYE 665 and 3′‐Iowa black‐labelled aptamer beacon. The aptamer beacon exhibited a mild 'lights on' reaction in buffer as a function of increasing concentrations of several vitamin D analogues and metabolites, with a limit of detection of approximately 200 ng/mL, and was not specific for any particular congener. In 10% or 50% human serum, the same aptamer beacon inverted its fluorescence behaviour to become a more intense 'lights off' reaction with an improved limit of detection in the range 4–16 ng/mL. We hypothesized that this drastic change in fluorescence behaviour was due to the presence of creatinine and urea in serum, which might destabilize the quenched beacon, causing an increase in fluorescence followed by decreasing fluorescence as a function of vitamin D concentrations that may bind and quench increasingly greater fractions of the denatured beacons. However, the results of several control experiments in the presence of physiological or greater concentrations of creatinine and urea, alone or combined in buffer, failed to produce the beacon fluorescence inversion. Other possible mechanistic hypotheses are also discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Multifunctional organic–inorganic composite luminescent nanospheres
Authors: Zhu Yanyu , Zhao Yaoyao , Ma Yingxin , Deng Mingliang , Wang Leyu 
Published: June 2011

ABSTRACTA simple general strategy was successfully developed for the preparation of magnetic–luminescent multifunctional nanocomposites by incorporating fluorescent (pyrene) and magnetic (Fe3O4) components simultaneously into a poly(styrene‐co‐methacrylic acid) [poly(St‐co‐MAA)] copolymer matrix. The nanospheres so prepared were characterized using scanning electron microscopy (SEM), powder X‐ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The prepared magnetic–fluorescent inorganic–organic nanocomposites have excellent magnetic and photoluminescent properties. They can be used in magnetic separation of trace amounts of sample, fluorescence detection and imaging applications, including magnetic resonance imaging (MRI) and fluorescence imaging. The fluorescence quenching of the nanospheres in the presence of different amounts of Cu2+ ions was also investigated. Under optimal experimental conditions, the relative fluorescence intensity of the composite nanosphere colloidal solution is proportional to the concentration of Cu2+ ions, which indicates that these multifunctional nanocomposites can be used for the magnetic separation and fluorescence detection of Cu2+ ions. Copyright © 2011 John Wiley & Sons, Ltd.