bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modification of maleic anhydride–styrene copolymer with noradrenaline by chemical and enzymatic methods
Authors: Karakus Gulderen , Yenidunya Ali Fazil , Zengin Haci Bayram , Polat Zubeyde Akin 
Published: June 2011

AbstractMaleic anhydride copolymer was modified with another biologically active agent, noradrenaline (NA), using both chemical and enzymatic methods. The modification and synthesized products were named as follows: chemical modification, MASTNAc; enzymatic modification, MASTNAe; enzymatically synthesized MASTNA from individual monomers, MASTNAem. Chemical and enzymatic reactions were performed at 70°C and 38°C, respectively. In the chemical reactions azobisisobutyronitrile was used as the initiator. In the enzymatic reactions, an extracellular extract, including an enzyme with peroxidase‐like activity, was used. All the reactions were performed in an organic medium, methyl ethyl ketone. Structural characterization of the copolymer and modified copolymer were carried out by Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H NMR). FTIR and 1H NMR spectra confirmed that NA was successfully covalently bound onto the MAST copolymer backbone by both chemical and enzymatic methods. Surface morphology of the samples was studied by scanning electron microscopy. Results obtained indicated that chemical and enzymatic addition of NA to MAST backbone yielded products having quite similar physical and chemical properties. On the other hand, MASTNA‐modified copolymer synthesized by individual monomers appeared to be different in its chemical structure. Furthermore, enzymatic modification and synthesis appeared to provide a good alternative method because it required much milder conditions such as low temperature, and better product qualities: higher solubility in water, higher yield and purity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Mechanical and viscoelastic properties of soybean oil thermoset reinforced with jute fabrics and carded lyocell fiber
Authors: Adekunle Kayode , Patzelt Christian , Kalantar Adib , Skrifvars Mikael 
Published: June 2011

AbstractComposites and hybrid composites were manufactured from renewable materials based on jute fibers, regenerated cellulose fibers (Lyocell), and thermosetting polymer from soybean oil. Three different types of jute fabrics with biaxial weave architecture but different surface weights, and carded Lyocell fiber were used as reinforcements. Hybrid composites were also manufactured by combining the jute reinforcements with the Lyocell. The Lyocell composite was found to have better mechanical properties than other composites. It has tensile strength and modulus of about 144 MPa and 18 GPa, respectively. The jute composites also have relatively good mechanical properties, as their tensile strengths and moduli were found to be between 65 and 84 MPa, and between 14 and 19 GPa, respectively. The Lyocell‐reinforced composite showed the highest flexural strength and modulus, of about 217 MPa and 13 GPa, respectively. In all cases, the hybrid composites in this study showed improved mechanical properties but lower storage modulus. The Lyocell fiber gave the highest impact strength of about 35 kJ/m2, which could be a result of its morphology. Dynamic mechanical analysis showed that the Lyocell reinforced composite has the best viscoelastic properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Chemical modification and synthesizing conditions of nanocomposite hydrogels with high mechanical strength crosslinked by hydrophilic reactive microgels
Authors: Qin Xuping , Zhao Fang , Feng Shengyu 
Published: June 2011

AbstractSeries of polyacrylamide hydrogels with high mechanical strength were synthesized using hydrophilic reactive microgels (HRM) with CC double bonds as crosslinkers. The hydrophilic microgels were prepared by inverse emulsion photopolymerization and then were chemical modified by N‐methylolacrylamide (NMA) to obtain HRM. Chemical‐modifying conditions affecting the HRM double bound content were investigated. The maximum double‐bond content was 1.82% at the optimum conditions of NMA 8 g, hydrochloric acid 0.8 mL, reaction temperature 60°C, and time 4 h. The mechanical properties of the hydrogels were significantly enhanced by using HRM as crosslinkers instead of the conventional crosslinkers. These HRM hydrogels were studied by varying such parameters as HRM content, monomer concentration, HRM double‐bond content, and the initiator dosage. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
The Recent Updates of Therapeutic Approaches Against Aβ for the Treatment of Alzheimer's Disease
Authors: Ling Shucai , Zhou Jing , Rudd John A. , Hu Zhiying , Fang Marong 
Published: June 2011

AbstractOne of the main neuropathological lesions observed in brain autopsy of Alzheimer's disease (AD) patients is the extracellular senile plaques mainly composed of amyloid‐beta (Aβ) peptide. Recently, treatment strategies have focused on modifying the formation, clearance, and accumulation of this potentially neurotoxic peptide. β‐ and γ‐secretase are responsible for the cleavage of amyloid precursor protein (APP) and the generation of Aβ peptide. Treatments targeting these two critical secretases may therefore reduce Aβ peptide levels and positive impact on AD. Vaccination is also an advanced approach against Aβ. This review focuses on recent advances of our understanding of this key peptide, with emphasis on Aβ peptide synthesis, accumulation and neurotoxicity, and current therapies including vaccination and two critical secretase inhibitors. MicroRNAs (miRNAs) are a class of conserved endogenous small noncoding RNAs, known to regulate the expression of complementary messenger RNAs, involved in AD development. We therefore address the relationship of miRNAs in the brain and Aβ generation, as a novel therapeutic approach to the treatment of AD while also providing new insights on the etiology of this neurological disorder. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
High‐Intensity Resistance Training with Insufficient Recovery Time Between Bouts Induce Atrophy and Alterations in Myosin Heavy Chain Content in Rat Skeletal Muscle
Authors: De Souza Rodrigo Wagner Alves , Aguiar Andreo Fernando , Carani Fernanda Regina , Campos Gerson Eduardo Rocha , Padovani Carlos Roberto , Silva Maeli Dal Pai 
Published: June 2011

AbstractThe aim of this study was to test whether high‐intensity resistance training with insufficient recovery time between bouts, could result in a decrease of muscle fiber cross‐sectional area (CSA), alter fiber‐type frequencies and myosin heavy chain (MHC) isoform content in rat skeletal muscle. Wistar rats were divided into two groups: trained (Tr) and control (Co). Tr group were subjected to a high‐intensity resistance training program (5 days/week) for 12 weeks, involving jump bouts into water, carrying progressive overloads based on percentage body weight. At the end of experiment, animals were sacrificed, superficial white (SW) and deep red (DR) portions of the plantaris muscle were removed and submitted to mATPase histochemical reaction and SDS‐PAGE analysis. Throughout the experiment, both groups increased body weight, but Tr was lower than Co. There was a significant reduction in IIA and IID muscle fiber CSA in the DR portion of Tr compared to Co. Muscle fiber‐type frequencies showed a reduction in Types I and IIA in the DR portion and IID in the SW portion of Tr compared to Co; there was an increase in Types IIBD frequency in the DR portion. Change in muscle fiber‐type frequency was supported by a significant decrease in MHCI and MHCIIa isoforms accompanied by a significant increase in MHCIIb isoform content. MHCIId showed no significant differences between groups. These data show that high‐intensity resistance training with insufficient recovery time between bouts promoted muscle atrophy and a transition from slow‐to‐fast contractile activity in rat plantaris muscle. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Increased Expression of Sodium Channel Subunit Nav1.1 in the Injured Dorsal Root Ganglion After Peripheral Nerve Injury
Authors: Wang Wei , Atianjoh Fidelis , Gauda Estelle B. , Yaster Myron , Li Yunqing , Tao Yuan‐Xiang 
Published: June 2011

AbstractThe mechanisms underlying neuropathic pain induction are very complex but might involve abnormal spontaneous activity in the sensory dorsal root ganglion (DRG). Voltage‐gated sodium channels in the DRG are essential for the genesis of abnormal spontaneous neuronal activity. In this study, we examined the changes in expression of the voltage‐gated sodium channel Nav1.1 in the DRG after peripheral nerve injury. Western blot analysis showed that the level of Nav1.1 protein in the ipsilateral L5 DRG was significantly increased on Days 3 and 7 after fifth lumbar spinal nerve ligation. Immunohistochemical study further confirmed a marked increase in the percentage of Nav1.1‐positive cells in the ipsilateral DRG on Day 3 after fifth lumbar spinal nerve ligation. Similarly, on Day 7 after sciatic nerve axotomy, the amount of Nav1.1 protein and the percentage of Nav1.1‐positive cells in the ipsilateral L5 DRG were also significantly increased. Our results suggest that an early increase in DRG Nav1.1 expression after peripheral nerve injury might be involved in the induction of neuropathic pain. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Extrahepatic and Intrahepatic Human Portal Interstitial Cajal Cells
Authors: Rusu M.C. , Pop F. , Hostiuc S. , Curcă G.C. , Streinu‐Cercel A. 
Published: June 2011

AbstractPortal interstitial cells of Cajal (PICCs), acting as vascular pacemakers, were previously only identified in nonhumans. Moreover, there is no evidence available about the presence of such cells within the liver. The objective of the study is to evaluate whether or not PICCs are identifiable in humans and, if they are, whether or not they are following the scaffold of portal vein (PV) branches within the liver. We obtained extrahepatic PVs and liver samples from six adult human cadavers, negative for liver disease, in accordance with ethical rules. They were stained with hematoxylin‐eosin (HE) and Giemsa, and then we performed immunohistochemistry on formalin‐fixed paraffin‐embedded specimens for CD117/c‐kit, a marker of the Cajal's cells. Immune labeling was also performed for S‐100 protein, desmin, glial fibrillary acidic protein (GFAP), neurofilaments, α‐smooth muscle actin (α‐SMA), and CD34. c‐kit‐Positive PICCs were identified within the extrahepatic PV, in portal spaces, and septa. On adjacent sections, these PICCs were negative for all the other antibodies used. In conclusion, our study confirms the presence of extrahepatic PICCs on humans, which may act as a possible intrinsic pacemaker in the human PV. However, the intrahepatic PICCs, which were evidenced here for the first time, are in need for further experimental studies to evaluate their functional role. A promising further direction of the study is the PICCs role in the idiopathic portal hypertension. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
Stiff, Multistimuli‐Responsive Supramolecular Hydrogels as Unique Molds for 2D/3D Microarchitectures of Live Cells
Authors: Komatsu Harunobu , Tsukiji Shinya , Ikeda Masato , Hamachi Itaru 
Published: June 2011

AbstractSupramolecular hydrogels constructed through molecular self‐assembly of small molecules have unique stimuli‐responsive properties; however, they are mechanically weak in general, relative to conventional polymer gels. Very recently, we developed a zwitterionic amino acid tethered amphiphilic molecule 1, which gave rise to a remarkably stiff hydrogel comparable with polymer‐based agarose gel, retaining reversible thermal‐responsive properties. In this study, we describe that rational accumulation of multiple and orthogonal noncovalent interactions in the supramolecular nanofibers of 1 played crucial roles not only in the mechanical reinforcement but also in the multistimuli responsiveness. That is, the zwitterionic amino acid moiety and the CC double bond unit of the hydrogelator 1 can function as a pH‐responsive unit and a light‐responsive unit, respectively. We also demonstrated that this stiff and multistimuli‐responsive supramolecular hydrogel 1 is applied as a unique mold for 2D and 3D‐patterning of various substances. More significantly, we succeeded in the fabrication of a collagen gel for spatial patterning, culturing, and differentiation of live cells by using hydrogel 1 molds equipped with 2D/3D microspace channels (100–200 μm in diameter).
Synthesis and Photophysical Properties of Dimethoxybis(3,3,3‐trifluoropropen‐1‐yl)benzenes: Compact Chromophores Exhibiting Violet Fluorescence in the Solid State
Authors: Shimizu Masaki , Takeda Youhei , Higashi Masahiro , Hiyama Tamejiro 
Published: June 2011

AbstractDimethoxybis(3,3,3‐trifluo‐ropropen‐1‐yl)benzenes were prepared through palladium‐catalyzed double cross‐coupling reactions of diiododimethoxybenzenes with CF3C≡CZnCl, followed by reduction of CF3C≡C groups with LiAlH4 or H2 in the presence of the Lindlar catalyst. The edges of the absorption spectra of 1,2‐(MeO)2‐4,5‐(CF3CHC=CH)2benzenes 1 and 1,3‐(MeO)2‐4,6‐(CF3CH=CH)2benzenes 2 in cyclohexane ranged from 348 to 360 nm, whereas the absorption spectra of 1,4‐(MeO)2‐2,5‐[(E)‐CF3CH=CH]2 benzene ((E)‐3) ended at 406 nm. These findings indicate that the effective conjugation length of (E)‐3 was significantly larger than those of 1 and 2. Consistently, 1 and 2 in cyclohexane exhibited fluorescence with emission maxima in the UV region, whereas (E)‐3 in cyclohexane emitted violet light with an emission maximum at 407 nm. All the fluorescence spectra of 1–3 in various solvents redshifted as the solvent polarity increased. The photoluminescence of 1, E‐1, Z‐1, 2, E‐2, E‐2H, Z‐2, E‐3, E‐3H, Z‐3 in the solid states was also observed with emission maxima in the violet region. It is important to note that the quantum yields of (E)‐3 in a neat thin film and in a doped polymer film were 0.37 and 0.49, respectively. Density functional theory calculations suggested that the fluorine atoms contribute to a slight extension of both the HOMOs and the LUMOs, as well as narrowing of the HOMO–LUMO gaps when compared with the corresponding fluorine‐free analogues. In the case of (E)‐3, it is suggested that the HOMO–LUMO transition includes charge transfer from the ethereal oxygen atoms to the C(sp2)CF3 moieties.
Microwave‐Assisted Tandem Transformation on an Ionic‐Liquid Support: Efficient Synthesis of Pyrrolo/Pyridobenzimidazolones and Isoindolinone‐Fused Benzimidazoles
Authors: Thummanagoti Suman , Yellol Gorakh S. , Sun Chung‐Ming 
Published: June 2011

AbstractA tandem transformation that involves the formation of three bonds and two heterocyclic rings in a one‐pot fashion through amino‐alkylation of an ionic‐liquid‐immobilized diamine with keto acids followed by successive double intramolecular cyclizations to afford a tricyclic framework has been explored. This tandem cyclization has been utilized to develop a rapid and efficient method to synthesize various pyrrolo[1,2‐a]benzimidazolones and pyrido[1,2‐a]benzimidazolones on an ionic‐liquid support by using focused microwave irradiation. The application of this tandem cyclization was further extended to the aromatic keto acids to provide isoindolinone‐fused benzimidazoles, a structurally heterogeneous library with skeletal diversity. The outcome of the cascade reaction was confirmed by the X‐ray crystallographic study of the product directly attached to the ionic‐liquid support. Use of the ionic liquid as a soluble support facilitates purification by simple precipitation along with advantages like high loading capacity, homogeneous reaction conditions, and monitoring of the reaction progress by regular conventional spectroscopic methods, whereas application of microwave irradiation greatly accelerates the rate of the reactions.
Bio‐entity network for analysis of protein–protein interaction networks
Authors: Ren Li‐Hong , Shen Yi‐Zhen , Ding Yong‐Sheng , Chou Kuo‐Chen 
Published: June 2011

AbstractProtein–protein interactions (PPIs) are vitally important for every process in a living cell. Information about these interactions can improve our understanding of diseases and provide the basis to revolutionize therapeutic treatments. However, since PPIs are involved with extremely complicated biological processes, it is necessary to develop novel tools to deal with this kind of network systems. To realize this, a bio‐entity network approach is introduced to show the topology structure of dynamic and collective performances of PPI networks and analyze the variance of the protein node that plays an important role in the PPI network. Also, spectrum analysis is used to capture the discrete and stochastic feature of PPIs. The yeast protein interaction network is considered as a paradigm. It is demonstrated that the proposed approach can easily and clearly identify the hub‐proteins that have the most impact on the PPI system concerned. It is expected that the bio‐entity network approach as presented in this paper might become a useful tool in system biology.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
How do we establish a biological marker for a behaviorally defined disorder? Autism as a test case
Authors: Yerys Benjamin E. , Pennington Bruce F. 
Published: June 2011

AbstractWe discuss the recent push to develop support vector machines and other cluster analyses as a means for biological signatures as early screens for autism. These methods not only hold great promise but also require careful consideration prior to implementation. We outline three validity tests and potential methods for addressing them. Autism Res 2011,4:239–241. © 2011 International Society for Autism Research, Wiley Periodicals, Inc.
Some implications of biofuel development for engineering infrastructures in the United States
Authors: Ng Tze Ling , Cai Ximing , Ouyang Yanfeng 
Published: June 2011

AbstractUnder the US Environmental Protection Agency's Renewable Fuel Standard (RFS) program, mandates to increase the consumption of renewable fuels in transportation in the USA are leading to the emergence of a biofuel economy with infrastructure implications. This shift requires immediate consideration, as current engineering infrastructures may not be sufficient to support the realization of the mandates. New biorefineries will need to be established where suitable land is available and the climate is appropriate for growing feedstocks. Investments may need to be made to accommodate increases in local, regional, and national traffic from the transport of feedstocks and finished biofuels. Further, the large water demands of biorefineries and of growing feedstocks impose even greater pressure on water supply utilities. Higher sediment and nutrient runoffs from more intensive cultivation of corn (as feedstock for ethanol) have negative water quality effects that may lead to the need for upgrading drinking‐water treatment facilities. Any infrastructure expansion should be conducted strategically, keeping in mind resource constraints, and environmental and social impacts. To understand the infrastructure needs and bottlenecks of biofuel development, a systems approach encompassing all aspects of the problem is essential. Research is needed to quantify the interdependencies, resiliency, and sustainability of the entire system in meeting biofuel goals. Research is also needed to integrate the social and physical aspects of the problem into a holistic framework for planning and management purposes. This paper reviews the literature to gain insights into some implications of biofuel development for engineering infrastructures in the USA. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd
Near‐field dosimetry for in vitro exposure of human cells at 60 GHz
Authors: Zhadobov Maxim , Sauleau Ronan , Augustine Robin , Le Quément Catherine , Le Dréan Yves , Thouroude Daniel 
Published: June 2011

AbstractDue to the expected mass deployment of millimeter‐wave wireless technologies, thresholds of potential millimeter‐wave‐induced biological and health effects should be carefully assessed. The main purpose of this study is to propose, optimize, and characterize a near‐field exposure configuration allowing illumination of cells in vitro at 60 GHz with power densities up to several tens of mW/cm2. Positioning of a tissue culture plate containing cells has been optimized in the near‐field of a standard horn antenna operating at 60 GHz. The optimal position corresponds to the maximal mean‐to‐peak specific absorption rate (SAR) ratio over the cell monolayer, allowing the achievement of power densities up to 50 mW/cm2 at least. Three complementary parameters have been determined and analyzed for the exposed cells, namely the power density, SAR, and temperature dynamics. The incident power density and SAR have been computed using the finite‐difference time‐domain (FDTD) method. The temperature dynamics at different locations inside the culture medium are measured and analyzed for various power densities. Local SAR, determined based on the initial rate of temperature rise, is in a good agreement with the computed SAR (maximal difference of 5%). For the optimized exposure setup configuration, 73% of cells are located within the ±3 dB region with respect to the average SAR. It is shown that under the considered exposure conditions, the maximal power density, local SAR, and temperature increments equal 57 mW/cm2, 1.4 kW/kg, and 6 °C, respectively, for the radiated power of 425 mW. Bioelectromagnetics 33:55–64, 2012. © 2011 Wiley Periodicals, Inc.
Two‐compartment method for determination of the oxygen transfer rate with electrochemical sensors based on sulfite oxidation
Authors: Glazyrina Julia , Materne Eva , Hillig Friederike , Neubauer Peter , Junne Stefan 
Published: June 2011

AbstractThe dissolved oxygen concentration is a crucial parameter in aerobic bioprocesses due to the low solubility of oxygen in water. The present study describes a new method for determining the oxygen transfer rate (OTR) in shaken‐culture systems based on the sodium sulfite method in combination with an electrochemical oxygen sensor. The method replaces the laborious titration of the remaining sulfite by an on‐line detection of the end point of the reaction. This method is a two‐step procedure that can be applied in arbitrary flasks that do not allow the insertion of electrodes. The method does not therefore depend on the type of vessel in which the OTR is detected. The concept is demonstrated by determination of the OTR for standard baffled 1‐L shake flasks and for opaque Ultra Yield™ flasks. Under typical shaking conditions, kLa values in the standard baffled flasks reached values up to 220 h‐1, whereas the kLa values of the Ultra Yield flasks were significantly higher (up to 422 h‐1).