bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of 2‐(9H‐carbazole‐9‐yl)ethyl methacrylate: Electrochemical impedance spectroscopic study of poly(2‐(9H‐carbazole‐9‐yl)ethyl methacrylate) on carbon fiber
Authors: Ates Murat , Uludag Nesimi , Sarac A. Sezai 
Published: April 2011

AbstractIn this contribution, 2‐(9H‐carbazol‐9‐yl) ethyl methacrylate (CzEMA) monomer was chemically synthesized. The monomer characterization was performed by FT‐IR, 1H‐NMR, 13C‐NMR, and melting point analysis. The electropolymerization of CzEMA was studied onto carbon fiber microelectrodes (CFMEs) as an active electrode material in 0.1M sodium perchlorate (NaClO4)/acetonitrile (ACN) solution. The electropolymerization experiments were done from 1 mM to 10 mM. The detailed characterization of the resulting electrocoated Poly (CzEMA)/CFME thin films was studied by various techniques, i.e., cyclic voltammetry (CV), Scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). The effects of initial monomer concentrations (1, 3, 5, and 10 mM) during the preparation of modified electrodes were examined by EIS. Capacitive behaviors of modified CFMEs were defined via Nyquist, Bode‐magnitude, and Bode‐phase plots. Variation of capacitance values by initial monomer concentration and specific capacitance values are presented. The highest specific capacitance value electrocoated polymer thin film by CV method in the initial monomer concentration of 5 mM with a charge of 52.74 mC was obtained about 424.1 μF cm−2. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation and characterization of chitosan‐coated hydroxyapatite nanoparticles as a promising non‐viral vector for gene delivery
Authors: Wang Jian‐Wen , Chen Ching‐Yi , Kuo Yi‐Ming 
Published: April 2011

AbstractChitosan‐coated hydroxyapatite (CS‐HAp) nanoparticles have been prepared successfully by a modified dropping method. Variations of the final solution pH values, concentration of CS, and CS/HAp volume ratio were examined for their effects on particle size, intensity of surface charge, and tendency of particle formation. The smallest nanoparticles carry a positive charge with 40–50 nm in width and 60–70 nm can be obtained when the CS/HAp ratio is 1 by controlling the final solution pH value at 6.5. The ability of nanoparticles to complex DNA, toxicity of nanoparticles, and the effect of CS‐HAp nanoparticle on transferring DNA were also investigated. Transgene expression in HeLa and NIH3T3 cell on the nanoparticles were significant after 2 days. Agarose gel electrophoresis indicated a probable multiple interaction between DNA and CS‐HAp while the interaction between DNA appears to be only ionic interaction. No toxic effect on the cells was seen with CS‐HAp. Lipofectin, however, was observed to engender marked cytotoxicity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Fabrication of electrospun nonwoven mats of polyvinylidene fluoride/polyethylene glycol/fumed silica for use as energy storage materials
Authors: Nguyen Thuy Thi Thu , Park Jun Seo 
Published: April 2011

AbstractNonwoven mats were fabricated from a polyvinylidene fluoride (PVDF)/polyethylene glycol 1000 Da (PEG 1000) blend by the electrospinning process. PEG 1000 is a low‐temperature phase change material that acts as a heat storage material, while PVDF serves as a supporting material to afford a mechanically strong form‐stable structure. Addition of fumed silica to electrospun (e‐spun) PVDF/PEG 1000 nanofibers helped prevent the leakage of molten PEG 1000 during the solid–liquid phase change, as confirmed by field emission scanning electron microscopy. It was also found that the addition of fumed silica helps improve the mechanical strength of the PVDF/PEG 1000 nonwoven mats. The thermal properties of PVDF/PEG 1000 and PVDF/PEG 1000/fumed silica composite nonwoven mats were investigated by differential scanning calorimetry. There were no significant changes in the melting temperature and heat of fusion of PEG 1000 after 100 heating/cooling cycles, thereby confirming that these nonwoven mats have high thermal stability. The fumed‐silica‐incorporated PVDF/PEG 1000 nonwoven mats had large energy storage capacity and excellent mechanical strength. Hence, the aforementioned types of mats are thought to have various applications in energy storage and in the manufacture of thermoregulating textiles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Influence of folate conjugation on the cellular uptake degree of poly(allylamine hydrochloride) microcapsules
Authors: Peng Caiyu , Zhang Yuying , Tong Weijun , Gao Changyou 
Published: April 2011

AbstractThe microcapsules in drug delivery systems can prevent degradation of drugs and help to control the release rate. To enhance the targeted delivery effect of the microcapsules to cancer cells, some specific ligands such as folic acid (FA) are necessarily further conjugated. Herein, covalent poly(allylamine hydrochloride) (PAH) multilayers were fabricated on CaCO3 microparticles under the cross‐linking of glutaraldehyde, which were further immobilized with different amount of FA molecules via the spacer of diamino terminated poly(ethylene glycol) (PEG). As a comparison study, four types of microcapsules, i.e., the PAH capsules, the PAH capsules grafted with PEG, and the PAH capsules conjugated with two different amount of FA via the PEG spacer were prepared. Their chemical and physical structures were confirmed by infrared spectroscopy, UV–vis spectroscopy and scanning electron microscopy. In vitro cell culture found that the cellular uptake of the PAH capsules grafted with PEG was reduced significantly compared with that of the pure PAH capsules. The FA‐modified microcapsules could be selectively delivered into HepG2 tumor cells which overexpress FA receptors but not into the endothelial cells. The number of HepG2 cells which ingested the FA‐conjugated capsules showed a positive correlation with FA amount. The results indicate that these FA conjugated capsules have a high selectivity to be delivered to tumor cells, endowing them with a larger opportunity functioning as targeted delivery vehicle for anticancer drugs. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of surface functionalization on the physicomechanical properties of a novel biofunctional copolymer
Authors: Sailaja Gopalakrishnanchettiar Sivakamiammal , Ramesh Parameswar , Varma Harikrishna 
Published: April 2011

AbstractThe physicomechanical properties of functionally active poly(hydroxyethyl methacrylate‐co‐methyl methacrylate) [poly(HEMA‐co‐MMA)] are evaluated. It has been reported that the surface phosphorylated poly(HEMA‐co‐MMA) is capable of eliciting direct bone bonding when implanted in vivo. Hence, it is important to examine the physicomechanical property of the copolymer as a function of surface modification. The properties assessed are differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), equilibrium swelling, compressive strength, and dynamic mechanical analysis. According to the DSC data, the glass transition temperature, Tg of poly(HEMA‐co‐MMA) is not significantly altered by surface phosphorylation. The TGA results demonstrated that unmodified and surface phosphorylated copolymers have similar degradation profile. The differential thermal analysis further supports the data. The equilibrium swelling of functionalized poly(HEMA‐co‐MMA) in phosphate buffer saline ascertained that surface phosphorylation significantly increased the hydrophilicity of the copolymer. The study further illustrated that the percentage of equilibrium swelling appreciably increases with increase in HEMA content in the copolymer and reached a plateau after 100 h. Both compressive strength and compressive modulus of poly (HEMA‐co‐MMA) decreased due to surface phosphorylation while dynamic storage modulus value was not altered. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A new method for the preparation of gelatin nanoparticles: Encapsulation and drug release characteristics
Authors: Naidu B. Vijaya Kumar , Paulson Allan T. 
Published: April 2011

AbstractA new and simple method was developed to produce gelatin nanoparticles of ∼ 30–40 nm for use as carriers for drug release applications. The nanoparticles were uniform in size and well dispersed. An anticancer drug, 5‐fluorouracil, was encapsulated with an efficiency as high as 85%. The nanoparticles showed sustained release of 5‐fluorouracil, and release rates varied with amount of crosslinking in the nanoparticles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Isothermal crystallization and melting behavior of polypropylene with lanthanum complex of cyclodextrin derivative as a β‐nucleating agent
Authors: Zeng Anran , Zheng Yuying , Qiu Shangchang , Guo Yong 
Published: April 2011

AbstractA novel highly active β‐nucleating agent, β‐cyclodextrin complex with lanthanum (β‐CD‐MAH‐La), was introduced to isotactic polypropylene (iPP). Its influence on isothermal crystallization and melting behavior of iPP was investigated by differential scanning calorimeter (DSC), wide‐angle X‐ray diffraction (WAXD), and polarized light microscopy (PLM). WAXD results demonstrated that β‐CD‐MAH‐La was an effective β‐nucleating agent, with β‐crystal content of iPP being strongly influenced by the content of β‐CD‐MAH‐La and the isothermal crystallization temperature. The isothermal crystallization kinetics of pure iPP and iPP/β‐CD‐MAH‐La was described appropriately by Avrami equation, and results revealed that β‐CD‐MAH‐La promoted heterogeneous nucleation and accelerated the crystallization of iPP. In addition, the equilibrium melting temperature (T) of samples was determined using linear and nonlinear Hoffman‐Weeks procedure. Finally, the Lauritzen‐Hoffman secondary nucleation theory was applied to calculate the nucleation parameter (Kg) and the fold surface energy (σe), the value of which verify that the addition of β‐CD‐MAH‐La reduced the creation of new surface for β‐crystal and then led to faster crystallization rate. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The adsorption behavior of Cu(II), Pb(II), and Co(II) of ethylene vinyl acetate‐clinoptilolite nanocomposites
Authors: Mthombo T. S. , Mishra A. K. , Mishra S. B. , Mamba B. B. 
Published: April 2011

AbstractIn this study, ethylene vinyl acetate (EVA) was mixed with clinoptilolite (C), a natural zeolite, to prepare EVA‐C nanocomposites. The films were characterized by SEM‐EDS, XRD, and FT‐IR, and heavy metal removal was studied using the batch technique. The effects of the initial pH value and concentration of solutions, contact time, and filler dosage on the adsorption capacity of the composites were investigated. To study the influence of pretreatment on the filler, clinoptilolite was activated using KCl, NaCl, and HCl. Adsorption results show that equilibrium was reached after 24 h, and that sorption reached its maximum at pH values between 5 and 7. The selectivity trend was observed to be Pb > Cu > Co, which was consistent for both single and mixed metal‐ion solutions. Pretreatment significantly increased adsorption capacity of the composite, but was dependent on the conditioning reagent. Nanocomposites filled with HCl‐activated particles demonstrated a high adsorption capacity of between 70 and 80% for all three metals, while KCl‐activated particles were the least efficient with a maximum adsorption capacity of 69% for Pb(II), 54% for Cu(II) and 48% for Co(II). The adsorption data were then fitted to both Langmuir and Freundlich isotherms over the entire concentration range, and the Langmuir isotherm showed a better fit of the experimental sorption data than the Freundlich isotherm. The results obtained show that this simple methodology which can be up‐scaled has great potential for the preparation of a wide variety of similar particle‐filled adsorbent nanocomposites in other environmental remediation applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Improvement of tensile properties and elastic recovery in ethylene vinyl acetate copolymer/multiwalled carbon nanotube nanocomposite foams
Authors: Yu Duck‐Ryul , Kim Gue‐Hyun 
Published: April 2011

AbstractIn this study, ethylene vinyl acetate (EVA) copolymer/multiwalled carbon nanotube (MWCNT) nanocomposite foams were prepared to improve tensile properties without sacrificing elongation at break and compression set of EVA foams by using melt compounding method, the most compatible with current industrial applications. Without any modification of MWCNT and special treatment, a significant improvement of the mechanical properties including elastic recovery was observed for the EVA/MWCNT foams with only 1 phr MWCNT. Improvement of tensile strength and modulus without sacrificing elongation at break and elastic recovery of EVA/MWCNT foams with 1 phr MWCNT may have significant implications toward the elastomeric applications. Cell size and cell density of EVA and EVA/MWCNT foams were also investigated for various content of dicumyl peroxide. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Luminescent properties of europium complexes with bis(diphenylphosphino)alkane dioxides
Authors: Pekarkova Pavla , Spichal Zdenek , Taborsky Petr , Necas Marek 
Published: April 2011

ABSTRACTEu(NO3)3⋅5H2O and EuCl3⋅6H2O were allowed to react with bis(diphenylphosphino)alkane dioxides Ph2P(O)(CH2)nP(O)Ph2 (n = 2, 4, 6) to obtain polymeric and binuclear complexes. The prepared compounds were structurally characterized by X‐ray diffraction. Luminescence measurements (emission and excitation spectra, quantum yields, lifetimes) were compared with crystallographic data in order to find a relationship between luminescent properties of the Eu(III) complexes and their structures. The Eu(III) polymers, especially [Eu(dpphO2)2Cl2]+Cl–}n, have shown extremely long luminescence lifetimes, up to 3.73 ms, as a result of a highly protecting hydrophobic shield. Copyright © 2011 John Wiley & Sons, Ltd.
Synergistic effects between silibinin and antibiotics on methicillin‐resistant Staphylococcus aureus isolated from clinical specimens
Authors: Kang Hyun‐Kyung , Kim Hye‐Young , Cha Jeong‐Dan 
Published: April 2011

AbstractMethicillin‐resistant Staphylococcus aureus (MRSA) is a dangerous microorganism, and creates serious medical problems. It causes many types of infections in humans and often acquires multi‐drug resistance. In this study, silibinin was evaluated against 20 clinical isolates of MRSA, either alone or in combination with ampicillin or oxacillin, using a checkerboard assay. The silibinin exhibited good activity against isolates of MRSA, and MRSA ATCC33952 and MSSA ATCC25923, with minimum inhibitory concentrations/minimum bactericidal concentrations (MICs/MBCs) ranging between 2–8/4–16 μg/mL, for ampicillin 2–1024/2–2048 μg/mL, and for oxacillin 0.25–32/0.5–64 μg/mL. The range of MIC50 and MIC90 were 0.5–4 μg/mL and 2–8 μg/mL, respectively. The MICs/MBCs for the combination of silibinin plus oxacillin or ampicillin were reduced by ≥4‐fold against the MRSA isolates tested, demonstrating a synergistic effect, as defined by a fractional inhibitory concentration index (FICI) of ≤0.5. Furthermore, a time‐kill study evaluating the growth of the tested bacteria showed that growth was completely attenuated after 2–5 h of treatment with the 1/2 MIC of silibinin, regardless of whether it was administered alone or with oxacillin (1/2 MIC) or ampicillin (1/2 MIC). In conclusion, silibinin exerted synergistic effects when administered with oxacillin or ampicillin and the antibacterial activity and resistant regulation of silibinin against clinical isolates of MRSA might be useful in controlling MRSA infections.
Surface activation of dyed fabric for cellulase treatment
Authors: Schimper Christian B. , Ibanescu Constanta , Bechtold Thomas 
Published: April 2011

AbstractSurface activation of fabric made from cellulose fibres, such as viscose, lyocell, modal fibres and cotton, can be achieved by printing of a concentrated NaOH‐containing paste. From the concentration of reducing sugars formed in solution, an increase in intensity of the cellulase hydrolysis by a factor of six to eight was observed, which was mainly concentrated at the activated parts of the fabric surface. This method of local activation is of particular interest for modification of materials that have been dyed with special processes to attain an uneven distribution of dyestuff within the yarn cross‐section, e.g., indigo ring‐dyed denim yarn for jeans production. Fabrics made from regenerated cellulose fibres were used as model substrate to express the effects of surface activation on indigo‐dyed material. Wash‐down experiments on indigo‐dyed denim demonstrated significant colour removal from the activated surface at low overall weight loss of 4‐5%. The method is of relevance for a more eco‐friendly processing of jeans in the garment industry.
Total Synthesis of Plakortide E and Biomimetic Synthesis of Plakortone B
Authors: Sun Xiao‐Yu , Tian Xiang‐Yin , Li Zhen‐Wu , Peng Xiao‐Shui , Wong Henry N. C. 
Published: April 2011

AbstractThe total synthesis of plakortide E (1 a) is reported. A novel palladium‐catalyzed approach towards 1,2‐dioxolanes as well as an alternative substrate‐controlled route leading exclusively to cis‐highly substituted 1,2‐dioxolanes have been developed. A lipase‐catalyzed kinetic resolution was employed to provide optically pure 1,2‐dioxolane central cores. Coupling of the central cores and side chains was achieved by a modified Negishi reaction. All four isomeric structures of plakortide E methyl ester, namely, 26 a–d were synthesized. One of the structures, 26 d, was shown to be identical with the natural plakortide E methyl ester on the basis of 1H, 13C NMR spectra and specific rotation comparisons. With the plakortide E methyl ester (4S,6R,10R)‐(−)‐cis‐26 d and its other three isomers in hand, we successfully converted them into (3S,4S,6R,10R)‐plakortone B (2 a), and its isomers ent‐2 a, 2 b and ent‐2 b via an intramolecular oxa‐Michael addition/lactonization cascade reaction. Finally, saponification converted 1,2‐dioxolane 26 d into plakortide E (1 a) whose absolute configuration (4S,6R,10R) was confirmed by comparison of spectral and physical data with those reported.
Urocortin‐expressing olivocochlear neurons exhibit tonotopic and developmental changes in the auditory brainstem and in the innervation of the cochlea
Authors: Kaiser Alexander , Alexandrova Olga , Grothe Benedikt 
Published: April 2011

AbstractThe mammalian cochlea is under direct control of two groups of cholinergic auditory brainstem neurons, the medial and the lateral olivocochlear neurons. The former modulate the electromechanical amplification in outer hair cells and the latter the transduction of inner hair cells to auditory nerve fibers. The lateral olivocochlear neurons express not only acetylcholine but a variety of co‐transmitters including urocortin, which is known to regulate homeostatic responses related to stress; it may also be related to the ontogeny of hearing as well as the generation of hearing disorders. In the present study, we investigated the distribution of urocortin‐expressing lateral olivocochlear neurons and their connectivity and distribution of synaptic terminals in the cochlea of juvenile and adult gerbils. In contrast to most other rodents, the gerbil's audiogram covers low frequencies similar to humans, although their communication calls are exclusively in the high‐frequency domain. We confirm that in the auditory brainstem urocortin is expressed exclusively in neurons within the lateral superior olive and their synaptic terminals in the cochlea. Moreover, we show that in adult gerbils urocortin expression is restricted to the medial, high‐frequency processing, limb of the lateral superior olive and to the mid and basal parts of the cochlea. The same pattern is present in juvenile gerbils shortly before hearing onset (P 9) but transiently disappears after hearing onset, when urocortin is also expressed in low‐frequency processing regions. These results suggest a possible role of urocortin in late cochlear development and in the processing of social calls in adult animals. J. Comp. Neurol. 519:2758–2778, 2011. © 2011 Wiley‐Liss, Inc.
Cell‐type‐specific consequences of reelin deficiency in the mouse neocortex, hippocampus, and amygdala
Authors: Boyle Maureen P. , Bernard Amy , Thompson Carol L. , Ng Lydia , Boe Andrew , Mortrud Marty , Hawrylycz Michael J. , Jones Allan R. , Hevner Robert F. , Lein Ed S. 
Published: April 2011

AbstractThe disrupted cortical lamination phenotype in reeler mice and subsequent identification of the Reelin signaling pathway have strongly informed models of cortical development. We describe here a marker‐based phenotyping approach to reexamine the cytoarchitectural consequences of Reelin deficiency, using high‐throughput histology and newly identified panels of highly specific molecular markers. The resulting cell‐type‐level cytoarchitectural analysis revealed novel features of abnormal patterning in the male reeler mouse not obvious with less specific markers or histology. The reeler cortex has been described as a rough laminar inversion, but the data presented here are not compatible with this model. The reeler cortex is disrupted in a more complex fashion, with some regions showing a mirror‐image laminar phenotype. Major rostrocaudal and cell‐type‐specific differences in the laminar phenotype between cortical areas are detailed. These and similar findings in hippocampus and amygdala have implications for mechanisms of normal brain development and abnormalities in neurodevelopmental disorders. J. Comp. Neurol. 519:2061–2089, 2011. © 2011 Wiley‐Liss, Inc.
Compact Folding of Isolated Four‐Residue Neutral Peptide Chains: H‐Bonding Patterns and Entropy Effects
Authors: Plowright Richard J. , Gloaguen Eric , Mons Michel 
Published: April 2011

AbstractThe intrinsic folding of isolated neutral tetrapeptides is investigated by IR‐UV double‐resonance laser spectroscopy coupled to quantum chemistry (DFT‐D) calculations. Laser‐desorbed jet‐cooled Ac‐(Ala)3‐Phe‐NH2 as well as two other related four‐residue molecules are shown to fold according to the same 14‐7L‐X‐10II′‐7L compact, β‐hairpin‐like backbone pattern, leading to a remarkable closed daisy chain of H‐bonds along the molecule. Thermodynamic calculations confronted to the abundances observed show that these laser‐desorbed peptides are best described by a finite conformational temperature (typically ca. 300–450 K), which suggests that not only enthalpy but also entropy effects play an important role in selecting these structures within this temperature range.
A pairing‐free certificateless authenticated key agreement protocol
Authors: He Debiao , Chen Jianhua , Hu Jin 
Published: April 2011

SUMMARYMany certificateless two‐party authenticated key agreement schemes using bilinear pairings have been proposed. But the relative computation cost of the pairing is approximately twenty times higher than that of the scalar multiplication over elliptic curve group In order to improve the performance we propose a certificateless two‐party authenticated key agreement scheme without bilinear pairings in this paper. A security proof under random oracle model is also provided. Copyright © 2011 John Wiley & Sons, Ltd.
Construction of UHV AC test base of SGCC
Authors: Tao Yao , Shu‐sen Li , Xiong Wu 
Published: April 2011

SUMMARYIn order to research ultra high voltage (UHV) transmission technology systematically, State Grid Corporation of China launched the UHV AC test base project to provide strong technical support for UHV grid construction. The facilities including UHV power supply, UHV test lines, equipments qualified field, electromagnetic environmental laboratory, climate laboratory, UHV corona cage, impulse test field were built at the test base. Much useful experience had been achieved through the construction and research in the fields of UHV electromagnetic environment, external insulation characteristic, equipment technical requirements, equipments manufactory, electrical design, construction, test, and operation. It accelerated the construction of the UHV pilot project of China. Copyright © 2011 John Wiley & Sons, Ltd.