bluuebunny/crossref_metadata_2025 huggingface dataset:
Parsing neural mechanisms of social and physical risk identifications
Authors: Qin Jungang , Han Shihui
Published: June 2008

Psychometric studies of risk perception have categorized personal risks into social and physical domains. To investigate whether and how the human brain differentiates social and physical risks, we scanned human adults using functional magnetic resonance imaging when they identified potential risks involved in social and physical behaviors. We found that the identification of risky behaviors in both domains induced increased activations in the anterior medial prefrontal cortex (MPFC, BA9/10)/ventral anterior cingulate (ACC) and posterior cingulate (PCC) relative to identification of safe behaviors. However, social risks induced stronger anterior MPFC activation whereas physical risks were associated with stronger ventral ACC activity. In addition, anterior MPFC activity was negatively correlated with the rating scores of the degree of social risk whereas PCC activity was positively correlated with the rating scores of the degree of physical risk. Relative to an autobiographical control task, the social risk identification task induced stronger sustained activity in the left supplementary motor area/dorsal ACC and increased transient activity in bilateral posterior insula. The physical risk identification task, however, resulted in stronger sustained activity in the right cuneus/precuneus and increased transient activation in bilateral amygdala. Our results indicate the existence of distinct neural mechanisms underlying social and physical risk identifications and provide neural bases for the psychometric categorization of risks into different domains. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Effects of 5‐HT drugs in prefrontal cortex during memory formation and the ketamine amnesia‐model
Authors: Liy‐Salmeron Gustavo , Meneses Alfredo
Published: June 2008

This article describes a series of experiments investigating the effects of systemic or intraprefrontal administration of serotonergic agents on ketamine induced memory deficits in rats. First, rats were trained on an operant autoshaping task. Immediately after training, rats were injected with different doses of drug or saline. Following drug administration, rats were tested after 1.5 h for short‐term memory (STM) and 24 h for long‐term memory (LTM) of conditioned response. An increase or decrease in number of conditioned responses was an index of retention. The major results of this work show that ketamine impaired STM and this effect was reversed, by either systemic or intraprefrontal cortex administration of the agonist 5‐HT1A/78‐OH‐DPAT, the 5‐HT receptor antagonists MDL100907 (5‐HT2A), SB‐399885 (5‐HT6), and SB‐269970 (5‐HT7). The ketamine STM‐impairment effect was not altered by the 5‐HT1Aantagonist WAY 100635 or the 5‐HT1Bantagonist SB‐224289. Notably, prefrontal cortex inhibition of translation or transcription interrupted STM without affecting LTM suggesting different signaling mechanisms. The interacting effect of NMDA and serotonin agents in memory function is an interesting and important area of study;both receptors are considered to be important targets for the development of antipsychotic medication. Particularly, 5‐HT1A/7, 5‐HT2A5‐HT6, and 5‐HT7receptors present in prefrontal cortex, represent important targets for development of drugs for the treatment of SMT‐deficits. © 2008 Wiley‐Liss, Inc.
Studying the feasibility of using microirrigation systems for vegetable production in a canal command area
Authors: Kumar Satyendra , Imtiyaz M. , Kumar A.
Published: June 2008

Field investigations were carried out for 3 years with the aim of studying the feasibility of using microsprinkler and drip irrigation systems for vegetable production in a canal command area. These systems were compared with the existing flood irrigation method for onion production with four irrigation levels, viz. 0.60, 0.80, 1.00 and 1.20 of irrigation water to cumulative pan evaporation ratio (IW/CPE). Microsprinkler and drip irrigation systems were also compared with fertigation rate of 100 (50:25:25 NPK), 150 (75:37.5:37.5 NPK) and 200 (100: 50: 50 NPK) kg ha−1. Microirrigation systems resulted in higher onion yield and greater profitability than surface irrigation at each irrigation schedule. However, microsprinklers indicated better economics than a drip irrigation system. Microsprinkler, drip and surface irrigation system with 1.20 IW/CPE of irrigation produced maximum crop yields of 34.34, 33.10 and 22.57 t ha−1, respectively. Increased crop yield with microsprinkler and drip irrigation is the factor behind higher profitability than existing surface irrigation. Reduction in nutrient application by 25% in fertigation from the dose of flood irrigation did not reduce yield and net returns significantly. But net return was significantly higher in microsprinkler (Rs 67 334 ha−1) than drip (Rs 59 930 ha−1) fertigation. The overall results of the present study favoured microsprinkler over existing irrigation methods for onion production in a canal command area with higher profit under limited available surface water. Copyright © 2008 John Wiley & Sons, Ltd.
A novel low‐friction surface for biomedical applications: Modification of poly(dimethylsiloxane) (PDMS) with polyethylene glycol(PEG)‐DOPA‐lysine
Authors: Chawla Kanika , Lee Seunghwan , Lee Bruce P. , Dalsin Jeffrey L. , Messersmith Phillip B. , Spencer Nicholas D.
Published: June 2008

Aqueous biocompatible tribosystems are desirable for a variety of tissue‐contacting medical devices. L‐3,4‐dihydroxyphenylalanine (DOPA) and lysine (K) peptide mimics of mussel adhesive proteins strongly interact with surfaces and may be useful for surface attachment of lubricating polymers in tribosystems. Here, we describe a significant improvement in lubrication properties of poly (dimethylsiloxane) (PDMS) surfaces when modified with PEG‐DOPA‐K. Surfaces were characterized by optical and atomic force microscopy, contact angle, PM‐IRRAS, and X‐ray photoelectron spectroscopy. Such surfaces, tested over the course of 200 rotations (∼8 m in length), maintained an extremely low friction coefficient (μ) (0.03 ± 0.00) compared to bare PDMS (0.98 ± 0.02). These results indicate the potential applications of PEG‐DOPA‐K for the modification of device surfaces. Extremely low μ values were maintained over relatively long length scales and a range of sliding speeds without the need for substrate pre‐activation and in the absence of excess polymer in aqueous solution. These results were only obtained when DOPA was bound to lysine (modification with PEG‐DOPA did not have an effect on μ) suggesting the critical role of lysine in obtaining a lowered friction coefficient. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
E1A physically interacts with RUNX3 and inhibits its transactivation activity
Authors: Cha Eun‐Jeong , Oh Byung‐Chul , Wee Hee‐Jun , Chi Xin‐Zi , Goh Yun‐Mi , Lee Kyeong‐Sook , Ito Yoshiaki , Bae Suk‐Chul
Published: June 2008

The adenoviral gene, termed early region 1A (E1A), is crucial for transformation and has been used very effectively as a tool to determine the molecular mechanisms that underlie the basis of cellular transformation. pRb, p107, p130, p300/CBP, p400, TRRAP, and CtBP were identified to be E1A‐binding proteins and their roles in cellular transformation have been established. Although the major function of E1A is considered to be the regulation of gene expression that is critical for differentiation and cell cycle exit, one of the most significant questions relating to E1A transformation is how E1A mediates this regulation. RUNX3 is a transcription factor that was first described as a gastric cancer tumor suppressor but is now known to be involved in many different cancers. Exogenous expression of RUNX3 strongly inhibits the growth of cells. Here, we show that the adenovirus oncoprotein E1A interacts with RUNX3 in vitro and in vivo. RUNX3 interacts with the N‐terminus (amino acids 2‐29) of E1A, which is known to interact with p300/CBP, p400, and TRRAP. E1A interacts directly with the Runt domain of RUNX3 but does not interfere with CBFβ‐RUNX3 interactions. In addition, E1A inhibits the transactivation activity of RUNX3 on the p21WAF1/CIP1 promoter. Consistent with these observations, the growth inhibition induced by RUNX3 is reduced by E1A. These results demonstrate that E1A specifically binds to RUNX3 and inactivates its transactivation activity. We propose that one of the mechanisms for the oncogenic activity of E1A is the inhibition of RUNX3, similar to that of RB and p300/CBP. J. Cell. Biochem. 105: 236–244, 2008. © 2008 Wiley‐Liss, Inc.
Differential effect of materials for surface hemostasis on red blood cell morphology
Authors: Smith Carr J. , Vournakis John N. , Demcheva Marina , Fischer Thomas H.
Published: June 2008

The design of devices for surface (topical) hemostasis has been based on maximizing activation of platelets and accelerating coagulation pathways. The studies reported herein examine another aspect of blood contact with topical hemostasis materials, i.e., surface binding of red blood cells (RBCs) and related alterations in RBC morphology. Whole blood was allowed to contact poly‐N‐acetyl glucosamine (pGlcNAc) containing materials: pGlcNAc nanofibers with parallel polymer alignment (β‐pGlcNAc), chitin, and chitosan. The effect on RBC morphology and function via contact with the artificial surfaces on the cell's morphology was examined with scanning and transmission electron microscopy (TEM). β‐pGlcNAc was found to densely bind RBCs and induce a stomatocytic‐like morphology. Chitin and chitosan also bound RBCs, but with approximately 10‐fold lower levels and with less distinct general morphologies. β‐pGlcNAc is thus unique in the nature of its interaction with RBCs. These studies indicate that the differential ability of various materials to bind and alter the morphology of RBCs at the artificial surface interface with blood is an important consideration in the design of devices for surface hemostasis. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
Rapid detection of microorganisms with nanoparticles and electron microscopy
Authors: Naja Ghinwa , Hrapovic Sabahudin , Male Keith , Bouvrette Pierre , Luong John H. T.
Published: June 2008

Rapid detection of microorganisms is highly desirable. A procedure has been developed based on interactions between gold nanoparticles and proteins of microorganisms (Escherichia coli, Rhodococcus rhodochrous, and Candida sp.) followed by scanning electron microscopy (SEM). The nanoparticle‐cell interaction was confirmed by ultraviolet resonance Raman spectroscopy (UVRS) in the SEM focus. Cell suspensions in a buffer were interacted with gold nanoparticles (<10 nm in diameter) prepared from tetrachloroauric acid and sodium borohydride. Possible interference of elevated salt concentrations was eliminated by dialysis in deionized water. Small (10 μL) aliquots of cell‐nanoparticle suspensions were dried on a silicon wafer and photographed under an SEM. Characteristic bacterial or yeast cell images in the micrographs indicated the actual presence of microorganisms in the suspension examined. This was further confirmed by UV resonance Raman spectroscopy. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
Nurse staffing ratios: Trends and policy implications for hospitalists and the safety net
Authors: Conway Patrick H. , Tamara Konetzka R. , Zhu Jingsan , Volpp Kevin G. , Sochalski Julie
Published: June 2008

BACKGROUND:

Mandated minimum nurse‐to‐patient staffing ratio legislation was passed in California in 1999 and implemented January 1, 2004. Nurse staffing legislation is being considered in at least 25 other states.

OBJECTIVES:

The objectives of this study were: (1) to evaluate nurse staffing trends in California from 1993 to 2004, (2) to identify types of hospitals below minimum staffing ratios and staffing changes in 2004, the first year post‐implementation; and (3) to discuss possible implications of nurse staffing on hospitalists and their hospital‐based initiatives.

DESIGN, SETTING, PATIENTS:

We analyzed data from the medical‐surgical units of all short‐term acute‐care general hospitals in California from 1993 to 2004. The annual hospital staffing ratio is composed of the combined hours of registered nurses and licensed vocational nurses and total number of patient days on medical‐surgical units.

RESULTS:

Nurse staffing ratios were relatively unchanged from 1993 to 1999 and then increased significantly from 1999 to 2004, with the largest increase in 2004, the year the nurse staffing ratio was implemented. Types of hospitals more likely to be below minimum ratios had a high Medicaid/uninsured patient population and were government owned, nonteaching, urban, and in more competitive markets. Most hospitals below ratios were considered part of the health care “safety net.”

CONCLUSIONS:

Nurse staffing legislation may increase nurse staffing. However, mandated nurse staffing ratios without mechanisms to help achieve ratios may force hospitals, especially safety‐net hospitals, to make tradeoffs in other services or investments with unintended negative consequences for patients. Nurse staffing likely influences the outcomes of hospitalist‐led quality initiatives, but these effects need to be explored further. Journal of Hospital Medicine 2008;3:193–199. © 2008 Society of Hospital Medicine.
New and old challenges of sports drug testing
Authors: Botrè Francesco
Published: June 2008

This brief note gives a general overview on the activity of the antidoping laboratories accredited by the World Anti‐Doping Agency (WADA), outlining the evolution, over the last four decades, of the analytical methods and techniques in the detection of prohibited substances and methods. Special emphasis is given to the future trends of the fight against doping in sports, as seen from the perspective of a laboratory scientist, in the wider context of fair play, health protection, and perception of the activity of the antidoping laboratories by the general public. Copyright © 2008 John Wiley & Sons, Ltd.
Molecular structure and vibrational spectra of 3 (or 4 or 6)‐methyl‐5‐nitro‐2‐pyridinethiones: FT‐IR, FT‐Raman and DFT quantum chemical calculations
Authors: Wandas M. , Lorenc J. , Kucharska E. , Ma̧czka M. , Hanuza J.
Published: June 2008

IR and Raman spectra (RS) of polycrystalline 3‐(or 4 or 6)‐methyl‐5‐nitro‐2‐pyridinethione have been measured and analyzed by means of density functional theory (DFT) quantum chemical calculations. The B3LYP/6‐311G(2d,2p) approach has been applied for both the thiol and thione tautomers due to the possibility of the formation of these two thiole forms. Molecular structures of these compounds have been optimized starting from different molecular geometries of the thiol group and thione group. Two conformations of the 2‐mercaptopyridine, trans and cis, have been taken into account. It was shown that the studied compounds appear in the solid state in the thione form. The effect of the hydrogen‐bond formation in the studied compounds has been considered. Copyright © 2008 John Wiley & Sons, Ltd.
Electrical, Morphological and Rheological Study of Melt‐Mixed Polystyrene/Copper Nanowire Nanocomposites
Authors: Lin Bin , Gelves Genaro A. , Haber Joel A. , Pötschke Petra , Sundararaj Uttandaraman
Published: June 2008

Polystyrene and copper nanowires were melt‐mixedat 200 °C and 50 rpm in 5 mL and 15 mL DSM co‐rotating conical micro‐compounders (DSM5 and DSM 15), respectively. The electrical, morphological and rheological properties of the resulting nanocomposites were studied. The electrical percolation of nanocomposites is between 1.0 and 2.0 vol.‐% for the composites prepared in DSM5 and above 2.0 vol.‐% for the composites prepared in DSM15. SEM micrographs show smaller copper nanowire agglomerates inside polystyrene from DSM15 than those from DSM5. However, TEM micrographs reveal that both single copper nanowires and nanowire bundles coexist in the polymer matrix for the samples prepared in both micro‐compounders. No obvious microstructure transition is detected by the dynamic rheological data at 200 °C.

magnified image
Constructing the Phase Diagram of an Aqueous Solution of Poly(N‐isopropyl acrylamide) by Controlled Microevaporation in a Nanoliter Microchamber
Authors: Zhou Xuechang , Li Junfang , Wu Chi , Zheng Bo
Published: June 2008

This paper describes a poly(dimethylsiloxane) (PDMS)‐based microfluidic platform for constructing the phase diagram of poly(N‐isopropyl acrylamide) (PNIPAM) in aqueous solution. The PNIPAM solution was delivered into a nanoliter chamber through the main microchannel. An osmotic pressure difference was established between the chamber and the control microchannel by flowing a high‐concentration salt solution in the control microchannel. Controlled evaporation of water resulted in increasing concentration of PNIPAM. A phase diagram of PNIPAM was built by measuring the cloud points at different concentrations, with a minimum point at ≈40 wt.‐%. The microfluidic platform has the advantages of low sample consumption and rapid heat exchange rates, and allows studying viscous polymer solution.

magnified image
Interrupted Wet‐Spinning Process for Chitosan Hollow Fiber Elaboration
Authors: Araiza Rocio Nohemi Rivas , Rochas Cyrille , David Laurent , Domard Alain
Published: June 2008

Summary:Chitosan hollow fiber formation with a variable internal diameter was performed from a new wet‐spinning method in interrupted coagulation conditions by means of water washings. The main objective of the present study is to provide a better understanding of the physicochemical events involved during the chitosan fiber formation by this new wet‐spinning method.
Hydrogel of Guar Gum in Experimental Osteoarthritis in Rats
Authors: Cunha Pablyana L. R. , Castro Rondinelle R. , Rocha Francisco A. C. , Feitosa Judith P. A.
Published: June 2008

Summary:Commercial Guar Gum, a galactomannan polysaccharide, was purified by the use of two subsequent methods, including precipitation with Fehling solution in order to eliminate protein impurities. The protein content (3.6%) was totally removed. Glutaraldehyde cross‐linked gels were prepared with purified (GGP) and unpurified gum (GGU). The viscosity of the gels is similar to that of Hylan G‐F 20, a commercial substitute of hyaluronic acid, used in viscosupplementation in human osteoarthritis. Guar Gums (gel and solution) were injected intra‐articularly into the knee joints of rats subjected to experimental OA and the effect in hypernociception and cells influx measured. GGU promoted hypernociception and cell influx in naïve rats. GGP was innocuous to naïve rats and inhibited hypernociception, both as a gel or solution, to the same extent as Hylan G‐F20. GGP promotes analgesia in OA due to its carbohydrate component.
Synthesis of a New Hydrogel, Based on Guar Gum, for Controlled Drug Release
Authors: Panariello G. , Favaloro R. , Forbicioni M. , Caputo E. , Barbucci R.
Published: June 2008

Summary:Guar gum (GG) polymer was crosslinked in order to obtain a new hydrogel. The GG hydrogel has been characterized by means of FT‐IR spectroscopy, the determination of the water content, at different pH values, rheological measurements and in vitro release studies. The GG hydrogel shows a maximum water uptake at acid and basic pH values. The mechanical properties are investigated in order to verify the thixotropic behaviour of the material. In vitro release studies are conducted to evaluate the application of the GG hydrogel as a matrix for controlled drug release.
Kinetic Study of Bovine Serum Albumin (BSA) Released from Alginate‐Ca2+/PNIPAAm Hydrogels
Authors: Piai Juliana F. , de Moura Márcia R. , Rubira Adley F. , Muniz Edvani C.
Published: June 2008

Summary:In this work the releasing of Bovine Serum Albumin (BSA) from thermosensitive hydrogels of alginate‐Ca2+/PNIPAAm was investigated. The hydrogels are constituted of PNPAAm network interpenetrated in alginate‐Ca2+ network, so the hydrogels are IPN‐typed. The PNIPAAm network was synthesized in the first step in which the sodium alginate remained soluble. The alginate‐Ca2+ network was formed in the second step by immersion the membrane obtained on the first step in aqueous calcium chloride. It was changed the amount of NIPAAm in the feed solution of the first step. The fractions of BSA released as a function of time were treated according to the mathematical model recently published by our lab [J. Coll. Interf. Sci. 2007, 310, 128] that allows predicting the whole profile of solute released from polymer networks. This mathematical model is based in the partition phenomena. The amount of BSA released from alginate‐Ca2+/PNIPAAm hydrogels changes inversely to both amount of PNIPAAm and temperature. Thus, the IPN‐typed matrixes of alginate‐Ca2+/PNIPAAm may be considered as smart hydrogels for release the BSA because the amount and rate of released BSA can be tailored by the amount of PNIPAAm in the hydrogel and by the control of temperature. Finally, the whole profile of released BSA can be adequately fitted by the model based in the partition phenomenon. From that model the kinetic parameter t1/2 and rate constant of releasing, kR, were calculated for the different hydrogels investigated in this work.
Relaxation behavior study of silicone rubber crosslinked network under static and dynamic compression by electric response
Authors: Chen Ling , Chen Guohua
Published: June 2008

The macroscopical deformation and the microcosmic molecule motions of the polymer matrix under static and dynamic compression can be studied by observing and analyzing the corresponding electric response of its electrically conductive composite. The resistance of silicone rubber/graphite nanosheet nanocomposite under static and dynamic compression changes in different ways, which reflects clearly the corresponding deformation characteristics: under static compression, resistance relaxation occurs, according to which it is concluded that the constant strain transforms over time from the initial elastic one to the viscoelastic one; under dynamic compression, the resistance rises with continuously increasing strain, in terms of which it is considered that short relaxation times may not allow the transformation of strain to happen and the elastic strain is dominative. A similar expression of Burgers equation was adopted here for describing resistance relaxation of SR/GN nanocomposite and the Burger's model without the dashpot in series for the crosslinked polymer network was also used to model the corresponding deformation characteristics of the polymer matrix. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Dynamic mechanical properties of sisal fiber reinforced polyester composites fabricated by resin transfer molding
Authors: Sreekumar P.A. , Saiah Redouan , Saiter Jean Marc , Leblanc Nathalie , Joseph Kuruvilla , Unnikrishnan G. , Thomas Sabu
Published: June 2008

The dynamic mechanical properties of sisal fiber reinforced polyester composites fabricated by resin transfer molding (RTM) were investigated as a function of fiber content, frequency, and temperature. Investigation proved that at all temperature range the storage modulus (E′) value is maximum for the composites having fiber loading of 40 vol%. The loss modulus (E″) and damping peaks (tan δ) were lowered with increasing fiber content. The height of the damping peaks depends upon the fiber content and the fiber/matrix adhesion. The extent of the reinforcement was estimated from the experimental storage modulus, and it has been found that the effect of reinforcement is maximum at 40 vol% fiber content. As the fiber content increases the Tg from tan δ curve showed a positive shift. The loss modulus, storage modulus, and damping peaks were evaluated as a function of frequency. The activation energy for the glass transition increases upon the fiber content. Cole–Cole analysis was made to understand the phase behavior of the fiber reinforced composites. Finally, attempts were made to correlate the experimental dynamic properties with theoretical predictions. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Structure, interaction and thermal study in electrolyte of polyethylene oxide/silica/ammonium thiocynate nanocomposites
Authors: Pandey Kamlesh , Dwivedi Mrigank Mauli , Tripathi Mridula
Published: June 2008

Composite polymer electrolyte consisting of polymer (polyethylene oxide, PEO) and nanosized ceramic filler with different concentrations of salt have been synthesized and characterized. X‐ray diffraction analysis shows that polymer salt complex has been intercalated into the naometric silicate layers. IR spectra reveal that the polymer structure in the ceramic interlayer is similar to that of polymer salt complexes and there is a strong interaction between PEO:SiO2 and polymer‐salt complexes. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Preparation and thermal decomposition of PS/AG microspheres
Authors: Zhao Wen , Zhang Qiuyu , Zhang Junping , Zhang Hepeng
Published: June 2008

PS/Ag microspheres were prepared by electroless silver plating on PS microspheres. SEM, EDS, and XRD approved the successful formation of silver coatings on PS microspheres. The thermogravimetric analysis was studied using a TGA system. The Ozawa and Coats‐Redfern methods were exploited to calculate activation energy and determine thermal decomposition mechanism. The thermal decomposition mechanism of pure PS microspheres was also investigated to draw comparisons with the mechanism of PS/Ag microspheres. It has been found that the thermal decomposition mechanism of PS/Ag microspheres and PS microspheres were both A2 model. The activation energy of PS microspheres and PS/Ag microspheres is 76.76 kJ/mol and 78.61 kJ/mol, respectively. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Elastomeric composites based on ethylene–propylene–diene monomer rubber and conducting polymer‐modified carbon black
Authors: Domenech S.C. , Bendo L. , Mattos D.J.S. , Borges N.G. , Zucolotto V. , Mattoso L.H.C. , Soldi V.
Published: June 2008

Thermally stable elastomeric composites based on ethylene–propylene–diene monomer (EPDM) and conducting polymer‐modified carbon black (CPMCB) additives were produced by casting and crosslinked by compression molding. CPMCB represent a novel thermally stable conductive compound made via “in situ” deposition of intrinsically conducting polymers (ICP) such as polyaniline or polypyrrole on carbon black particles. Thermogravimetric analysis showed that the composites are thermally stable with no appreciable degradation at ca. 300°C. Incorporating CPMCB has been found to be advantageous to the processing of composites, as the presence of ICP lead to a better distribution of the filler within the rubber matrix, as confirmed by morphological analysis. These materials have a percolation threshold range of 5–10 phr depending on the formulation and electrical dc conductivity values in the range of 1 × 10−3 to 1 × 10−2 S cm−1 above the percolation threshold. A less pronounced reinforcing effect was observed in composites produced with ICP‐modified additives in relation to those produced only with carbon black. The results obtained in this study show the feasibility of this method for producing stable, electrically conducting composites with elastomeric characteristics. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Preparation and characterization of poly(styrene‐b‐butadiene‐b‐styrene)/montmorillonite nanocomposites
Authors: Chen Zhonghua , Feng Runcai
Published: June 2008

With some polymerizable small molecules grafting onto the montmorillonite surface, we disposed the clay through in‐situ emulsion polymerization, and the structure of the modified montmorillonites were studied through Fourier transform infrared spectroscopy (FTIR) and X‐ray diffraction (XRD). The nanocomposites of poly(styrene‐b‐butadiene‐b‐styrene) (SBS)/montmorillonite with excellent mechanical properties were prepared by mixing SBS and the modified montmorillonite on the double rollers at 150°C. The exfoliation of the layered silicates was confirmed by XRD analysis and transmission electron microscopy (TEM) observation. After mechanical kneading of the molten nanocomposites, the exfoliation structure of the silicates is still stable for polystyrene macromolecules grafting onto the silicates. Upon the addition of the modified montmorillonite, the tensile strength, elongation at break and tear strength of the nanocomposites increased from 22.6 MPa to 31.1 MPa, from 608% to 948%, from 45.32 N/mm to 55.27 N/mm, respectively. The low‐temperature point of glass‐transition temperature (Tg) of the products was about −77°C, almost constant, but the high‐temperature point increased from 97°C to 106°C. In addition, the nanocomposites of SBS and modified montmorillonites showed good resistance to thermal oxidation and aging. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Effects of magnesium hydroxide and its surface modification on crystallization and rheological behaviors of polypropylene
Authors: Chen Xiaolang , Yu Jie , Guo Shaoyun , Luo Zhu , He Min
Published: June 2008

In this article, polypropylene composites filled with magnesium hydroxide (PP filled with MH) were prepared in corotating twin‐screw extruder. The effects of MH particles content and types of treatment agents on the crystallization and melting behaviors, crystal structure, and rheological properties of PP/MH composites were studied by differential scanning calorimetry (DSC), a wide‐angle X‐ray diffraction, and dynamic rheological measurements. The DSC results show that MH particles act as a good heterogeneous nucleation effect on PP. Surface treatment of MH weakens its heterogeneous nucleation effect. The nucleating efficiency of MH on PP is found to depend strongly on its content and type of treatment agents. The dynamic rheological behaviors of MH filled PP is found that the complex viscosity (η*) increases with increasing MH content, whereas with increasing filler concentration the network structure becomes the prevailing process, which raises the η* values, especially at the low frequency zone. The η* values of the composites, however, decrease with the addition of various treatment agents. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Effect of nanoparticles on mode‐I fracture toughness of polyurethane foams
Authors: Saha Mrinal C. , Kabir Md. E. , Jeelani Shaik
Published: June 2008

Mode‐I fracture toughness of rigid polyurethane (PUR) foam modified with nanosize particles of different shapes and sizes have been examined using a single edge notched bend (SENB) specimen under three‐point bending configuration. The PUR foams with density of 260 kg/m3 and four different types of nanoparticles, namely, nano TiO2 (5, 10, and 35 nm), nanoclay, carbon nanofibers (CNFs), and multiwall carbon nanotubes (MWNTs) are considered. Nanophased PUR foams are prepared through the infusion of nanoparticles into liquid PUR foam precursor in the range of 0.5–2 wt% with 0.5‐wt% increment using a sonochemical method. The linear elastic fracture mechanics (LEFM) model has been used to determine the mode‐I fracture toughness. The fracture toughness data have been validated with the plain strain fracture criteria and found to be appropriate. It is observed that the infusion of CNF at 0.5‐wt% loading shows the highest enhancement in fracture toughness (about 28%) over neat counter part. Among different sized nano TiO2, 5 nm nanoparticles show the highest improvement (about 16%) at a doping of 1.0 wt%. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Melt compounding of various polymers with organoclay by shear flow
Authors: Koyama Terumasa , Tanoue Shuichi , Iemoto Yoshiyuki , Maekawa Tomokazu , Unryu Tsunemune
Published: June 2008

We studied melt compounding of polymer/organoclay composites by shear flow in a rotating cylindrical mixer to investigate an effect of shear stress on the dispersion state of clay. The commercial organoclay, which is intercalated by dimethyl benzyl stearyl ammonium ion between clay platelets, and four kinds of commercial polymer (polystyrene (PS), poly(lactic acid) (PLA), polyamide(PA6), and poly(butylene succinate) (PBS)) were used in this study. According to the TEM photographs, there is exfoliated clay in PA6/organoclay composite, but the exfoliated clay cannot be seen in other polymer/organoclay composites. We calculated the value of clay dispersion from the low magnification TEM photograph, called the dispersion coefficient to consider the micro level dispersion of the clay in a polymer matrix. Generally, the dispersion coefficient increases with shear stress. However, the dispersion coefficients in case using PA6 and PBS as the matrix, whose melts have low viscosity, are larger than those in case using PS and PLA, whose melts have high viscosity. According to XRD results, d001 peak originated from organoclay mostly shifted to the low value of angle for PA6/organoclay composite and began shifting to the low value of angle for PBS/organoclay composite. However, there is a peak for PS and PLA based organoclay composites. From the cases of PA6 and PBS in the DMA results, the storage modulus increases with an addition of organoclay. These results imply that low viscosity polymer is typical easy to get the composites with intercalated clay by melt compounding. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Phytomodulatory potentials of Aloe vera against Salmonella OmpR‐mediated inflammation
Authors: Rishi Praveen , Rampuria Anjali , Tewari Rupinder , Koul Ashwani
Published: June 2008

Mediators released during inflammatory response play an essential role in eliminating microbes or microbial products. However, the uncontrolled release of cytotoxic substances characterized by extensive inflammation may adversely affect normal tissues. Under such conditions it is important to manage the hyperinflammation in order to change the clinical manifestations of the disease. Accordingly, the present study was designed to evaluate the modulation of Salmonella OmpR mediated inflammation by Aloe vera, a plant known to contain antiinflammatory ingredients. It was observed that outer‐membrane proteins (OMPs) extracted from the wild type strain of S. typhimurium caused inflammation of greater magnitude compared with the OMPs extracted from its mutant construct as evident from the oedema test as well as the hyperalgesic (flicking) response of the animals under experimental conditions. However, Aloe vera applied topically, administered intraperitoneally or in combination modulated the inflammatory response. The maximum effect was observed with the combined formulation indicating modulation at local as well as systemic levels. The results reveal that this modulation could be due to the potential of Aloe vera to decrease peroxidative damage via a decrease in the levels of monokines (TNF‐α, IL‐1 and IL‐6) and an increase in the level of superoxide dismutase (SOD). Moreover, the presence of SOD in Aloe vera itself might be responsible for enhancing its levels in the macrophages. On the other hand, no significant change in the catalase activity was observed by Aloe vera treatment. The use of Aloe vera, therefore, seems to have a promising role in the modulation of Salmonella OmpR mediated inflammation. Copyright © 2008 John Wiley & Sons, Ltd.
RetractedDecreased FKBP12.6 expression and enhanced endothelin receptor signaling associated with arrhymogenesis in myocardial infarction rats
Authors: He Haibo , Shi Mengqiong , Zeng Xiaowei , Yang Xianzhe , Yang Jun , Wu Limao , Li Lianda
Published: June 2008

Scientific Deception: Retraction of a Fraudulent Paper

Andrew Coats
Elizabeth M. Williamson

We the editors of the International Journal of Cardiology and Phytotherapy Research regretfully report a case of scientific fraud. We have been made aware that two manuscripts published around the same time contain similar figures and tables. Upon further investigation the manuscript published in Phytotherapy Research 1 appears to have included falsely reproduced experiments with no acknowledgement of original source data and has consequently been retracted. The manuscript published in the International Journal of Cardiology 2 stands and there is no criticism of the authors of this paper.

1. He H, Shi M, Zeng X, Yang X, Yang J, Wu L, Li L.
Decreased FKBP12.6 expression and enhanced endothelin receptor signaling
associated with arrhymogenesis in myocardial infarction rats.
Phytother Res. 2008 Aug;22(8):1115‐24.
Doi: 10.1002/ptr.2470

2. Zhang Y, Huang ZJ, Dai DZ, Feng Y, Na T, Tang XY, Dai Y.
Downregulated FKBP12.6 expression and upregulated endothelin signaling contribute to elevated diastolic calcium and arrhythmogenesis in rat cardiomyopathy produced by l‐thyroxin. International Journal of Cardiology, [Epub ahead of print] Doi:10.1016/j.ijcard.2008.05.018
Pachypodol, a flavonol from the leaves of Calycopteris floribunda, inhibits the growth of CaCo 2 colon cancer cell line in vitro
Authors: Ali Husne‐Ara , Chowdhury A. K. Azad , Rahman Abul K. M. , Borkowski Tomasz , Nahar Lutfun , Sarker Satyajit D.
Published: June 2008

Calycopteris floribunda Lam., commonly known as ‘goichia lata or goache lata’, is a large climbing woody shrub from Bangladesh, and well distributed in a number of other south‐east Asian countries. Traditionally, C. floribunda has been used in colic, as an antihelminthic, astringent and carminative, and for the treatment of diarrhoea, dysentery, jaundice and malaria in many countries including Bangladesh. Pachypodol (5,4′‐dihydroxy‐3,7,3′‐trimethoxyflavone) has been isolated from the leaves of C. floribunda by repeated column chromatography on silica gel, and the structure confirmed by spectroscopic means. While the general toxicity of pachypodol was determined by the brine shrimp lethality assay, the cytotoxic potential of this flavonoid has been evaluated by the Promega's CellTiter 96 Non‐Radioactive Cell Proliferation Assay using the CaCo‐2 colon cancer cell line (IC50 = 185.6 µM). A summary of the biological activities of pachypodol reported to date is also presented. Copyright © 2008 John Wiley & Sons, Ltd.
Combined 13C NMR and DFT/GIAO studies of the polyketides Aurasperone A and Fonsecinone A
Authors: de Lazaro Sergio , Campos Francinete Ramos , Rodrigues‐Fo Edson , Barison Andersson , Daolio Cristina , Ferreira Antonio G. , Polo Victor , Longo Elson , Andrés Juan
Published: June 2008

Structural characterization by NMR spectroscopy and DFT calculations was performed for two dimeric naphtho‐γ‐pyrones, the polyketides Aurasperone A and Fonsecinone A. Experimental data (13C NMR chemical shifts and interatomic geometries) were found to be in reasonable agreement with theoretical ones, obtained at B3LYP level for three different basis sets (6‐31G/6‐31G(d)/6‐31G(d,p)). Additionally, the dipolar moments calculation allowed explaining the different solubility for these molecules. The 13C NMR theoretical chemical shifts were calculated with the GIAO method and the solvent effects were taken into account by means of the PCM approximation. In this work, the DFT/GIAO methodology shows to be a reliable tool in the assignment of experimental NMR chemical shifts of similar molecules. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Seven‐year performance evaluation of a permeable reactive barrier
Authors: Richards Peter
Published: June 2008

In June and July 2001, the Massachusetts Department of Environmental Protection (MassDEP) installed a permeable reactive barrier (PRB) to treat a groundwater plume of chlorinated solvents migrating from an electronics manufacturer in Needham, Massachusetts, toward the Town of Wellesley's Rosemary Valley wellfield. The primary contaminant of concern at the site is trichloroethene (TCE), which at the time had a maximum average concentration of approximately 300 micrograms per liter directly upgradient of the PRB. The PRB is composed of a mix of granular zero‐valent iron (ZVI) filings and sand with a pure‐iron thickness design along its length between 0.5 and 1.7 feet. The PRB was designed to intercept the entire overburden plume; a previous study had indicated that the contaminant flux in the bedrock was negligible. Groundwater samples have been collected from monitoring wells upgradient and downgradient of the PRB on a quarterly basis since installation of the PRB. Inorganic parameters, such as oxidation/reduction potential, dissolved oxygen, and pH, are also measured to determine stabilization during the sampling process. Review of the analytical data indicates that the PRB is significantly reducing TCE concentrations along its length. However, in two discrete locations, TCE concentrations show little decrease in the downgradient monitoring wells, particularly in the deep overburden. Data available for review include the organic and inorganic analytical data, slug test results from nearby bedrock and overburden wells, and upgradient and downgradient groundwater‐level information. These data aid in refining the conceptual site model for the PRB, evaluating its performance, and provide clues as to the reasons for the PRB's underperformance in certain locations. © 2008 Wiley Periodicals, Inc.
Citizen board issues and local newspaper coverage of risk, remediation, and environmental management: Six U.S. nuclear weapons facilities
Authors: Greenberg Michael , Lowrie Karen , Hollander Justin , Burger Joanna , Powers Charles , Gochfeld Michael
Published: June 2008

We examined site‐specific advisory board (SSAB) minutes and local newspaper coverage of the Fernald, Hanford, Idaho, Oak Ridge, Rocky Flats, and Savannah River sites of the U.S. Department of Energy (US DOE) in order to determine the importance of risk‐related issues related to remediation and other forms of environmental management. About one‐third of SSAB issues were risk‐related, and these were disproportionately major issues at meetings. The media focused on risks associated with remediation and other forms of waste management. The analysis implies that contractors and government officials need to establish and maintain communications with advisory panels and accentuate these contacts well in advance of contemplated new actions. © 2008 Wiley Periodicals, Inc.
Identification of pyrene‐degradation pathways: Bench‐scale studies using Pseudomonas fluorescens 29L
Authors: Husain Saleha
Published: June 2008

This article summarizes the bench‐scale studies to identify pyrene‐degradation pathways using an environmental microbial isolate, Pseudomonas fluorescens 29L. Strain 29L was grown on 50 mg of pyrene per liter of mineral medium. At a pyrene biodegradation rate of 14.7 mg/L of medium/day, 82.38 percent of pyrene was degraded in six days. Naphthalene and phenanthrene accounted for 1.09 percent and 3.69 percent, respectively, of the carbon mass from pyrene in the late log phase. Substituted benzene compounds accounted for 26.10 percent of the carbon mass from pyrene in the late log phase. In the stationary phase, carboxylic acids accounted for 10.44 percent of the carbon mass from pyrene. Strain 29L mutants were used for enzyme assays. Pyrene is oxidized by monoxygenases and dioxygenases, and the oxidized ring is cleaved. These enzymes were induced in the presence of pyrene and their activities peaked in the late log phase. No gentisate 1,2‐dioxygenase activity was detected in Strain 29L wild type (WT), whereas mutant M15 did not show any catechol 2,3‐dioxygenase activity. This indicates the possibility of multiple branchings in the pyrene‐biodegradation pathways. In conclusion, multiple degradative pathways are operating concurrently in this strain. The study shows the versatility of Pseudomonas fluorescens Strain 29L for pyrene degradation. It also emphasizes the need to study pyrene‐degradation pathways in other microorganisms so as to enhance the bioremediation potential for the in situ treatment of pyrene‐contaminated sites. © 2008 Wiley Periodicals, Inc.
A PARTICIPATORY APPROACH TO INCREASING PRODUCTIVITY OF MAIZE THROUGH STRIGA HERMONTHICA CONTROL IN NORTHEAST NIGERIA
Authors: KAMARA A. Y. , ELLIS-JONES J. , AMAZA P. , OMOIGUI L. O. , HELSEN J. , DUGJE I. Y. , KAMAI N. , MENKIR A. , WHITE R. W.
Published: June 2008

Striga hermonthica is a parasitic weed that attacks maize, sorghum and other staple cereal crops and has long been considered one of the greatest biotic constraints to cereal production in Africa. Use of resistant or tolerant maize varieties, a maize–legume rotation using trap crops that stimulate suicidal germination of Striga and the application of nitrogen fertilizer are all effective in reducing infestation and damage. This paper reports on the use of a participatory research and extension approach in assessing the performance and scaling-up of integrated Striga control packages in three agro-ecological zones in Borno State, Nigeria. The participatory process which encourages close interaction between research, extension and farmers, involved 30 local communities and 228 farmers representing 193 farmer groups in identifying their own problems and seeking solutions to them. Results showed not only effective Striga control but productivity increases of over 200%. The involvement of local farmers and groups in the evaluation process, firstly, helped to confirm that Striga control can best be achieved using soyabean followed by Striga-resistant maize together with productivity-increasing management practices and, secondly, promoted farmer-to-farmer extension. A participatory adoption assessment exercise indicated widespread adoption of new varieties and management practices, despite the need for increased labour. Great potential exists to scale out the results to similar areas of Guinea and Sudan savannas in the West Africa region.
THE ROLE OF CATTLE MANURE IN ENHANCING ON-FARM PRODUCTIVITY, MACRO- AND MICRO-NUTRIENT UPTAKE, AND PROFITABILITY OF MAIZE IN THE GUINEA SAVANNA
Authors: FRANKE A. C. , SCHULZ S. , OYEWOLE B. D. , DIELS J. , TOBE O. K.
Published: June 2008

An on-farm trial was conducted in the northern Guinea savanna of Nigeria, over a period of five years, with the objectives of quantifying the effects on maize of applying cattle manure in combination with synthetic fertilizer with regard to soil characteristics, yield, plant nutrition and profitability. Maize grain yield was significantly increased by the annual application of cattle manure, compared to maize receiving an equal amount of N through synthetic fertilizer, but only from the third year of the experiment. The application of manure resulted in higher soil Kjel N, Bray-I P and exchangeable K values, and an increased N utilization efficiency by maize, suggesting that yield-limiting factors other than N deficiencies were of lesser importance than in the treatment receiving sole inorganic fertilizer. Nutrients other than N applied via the manure, particularly P, K and/or B, may have contributed to the higher grain yields in treatments receiving manure. A partial budgeting analysis revealed that, over a 5-year period, investments in the application of manure, in combination with synthetic fertilizer, resulted in higher margins than the application of fertilizer alone. However, analyses of marginal rates of return of changes from low urea N to high urea N or additional manure applications suggested that it was more profitable to invest in additional urea than in organic manure in the first two years of the experiment. The results suggested that manure applications, even when applied at relatively high rates, did not serve as a quick fix to on-farm soil fertility problems, but over a longer period, manure applied in combination with synthetic fertilizers did provide a significant and profitable contribution to enhanced cereal production.