bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of relatively nontoxic thermal stabilizers on photodegradation of poly(vinyl chloride)
Authors: Xiang Xiuqin , Chen Shuangjun , Zhang Jun , Huang Xin
Published: December 2009

The influence of relatively nontoxic thermal stabilizers including different types of organic calcium complex (Ca/Zn system of liquid stabilizers) and organotin on photodegradation of poly(vinyl chloride) (PVC) was investigated by color difference measurement, viscosity‐average molecular weight determination, UV–vis spectroscopy, Fourier transform infrared (FTIR), and thermogravimetric (TG) analysis. PVC films containing relatively nontoxic thermal stabilizers were prepared by solution casting and then exposed to xenon‐arc light source with the irradiance of 0.51 W/(m2·nm) at 65°C. Two major chain processes, photodehydrochlorination and photo‐oxidation, occur simultaneously during photodegradation of PVC. It has been confirmed by both color difference and UV–vis spectra that during the former 300 h of irradiation, organic calcium complex stabilizers retard photodehydrochlorination as well as initial color development of PVC films while organotin stabilizers remarkably accelerate photodehydrochlorination after 100 h. Relative carbonyl index (RCI) is first introduced to the analysis of FTIR results, which implies that organotin has a better ability to inhibit photo‐oxidation than organic calcium complex and ensures longer stabilization time. The antioxidation of mercaptan organotin has been observed because it is an effective decomposer of peroxides and hydroperoxides. TG analysis reveals that some unstable structures generated due to the irradiation of ultraviolet can easily split away off from PVC macromolecular backbones under relatively low temperature. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Ionic liquids as plasticizers/lubricants for polylactic acid
Authors: Park Kuil , Ha Jin Uk , Xanthos Marino
Published: December 2009

In this study, two ionic liquids (IL) with different anions (decanoate, tetrafluoroborate) but with the same phosphonium‐based cation were evaluated as potential plasticizers and lubricants for polylactic acid (PLA). Both ILs at 5 wt% were well dispersible and partly miscible with PLA as evidenced by scanning electron microscopy, SEM, and glass transition temperature, Tg, characterization, as well as from solubility parameters calculations. However, phase separation in the PLA system containing the IL with tetrafluoroborate anions was observed 1 year after melt processing. The IL containing the tetrafluoroborate anion showed higher thermal stability compared with the IL containing decanoate as confirmed by thermogravimetric analysis. This was translated in corresponding behaviors of the PLA blends. The effects of the IL containing the tetrafluoroborate anion were more pronounced on lubrication as evidenced by lower values of coefficient of friction that could also be correlated with lower contact angle; this IL could then be considered as a more effective, overall, plasticizer than the IL containing the decanoate anion based on reduced flexural modulus and brittleness as well as Tg suppression results. The extent of plasticization, however, could also be related to the molecular weight reduction during melt processing that occurred in the presence of both ILs, but to different degrees. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Adhesion and delamination failure mechanisms in alternating layered polyamide and polyethylene with compatibilizer
Authors: Du Qin , Jiang Genjie , Li Jiang , Guo Shaoyun
Published: December 2009

The effects of compatibilizer and the number of layers on the interfacial adhesion and delamination model of coextruded microlayer samples consisting of alternating layers of high‐density polyethylene (HDPE) and polyamide 6 (PA6) were studied with T‐peel test. When more maleic anhydride‐grafted HDPE was incorporated into HDPE layer, the interfacial delamination model changed from adhesive to cohesive failure in the case of bilayer samples. For high‐layer samples, the results of X‐ray photoelectron spectroscopy showed that the areal density of copolymers at the interfaces increased with increasing number of layers due to strong and durable shearing forces during microlayer coextrusion. Scanning electron microscopy observation revealed that the interfacial delamination model changed from single‐ to multiple‐interface delamination when the number of layers increased from 16 to 32. The crack propagation included a large number of layer–layer jumps. The peel strength of microlayer samples was found to be greatly influenced by the interfacial delamination mechanisms. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Operating window for the peeling of polyimide film
Authors: Wang Han‐Yi , Liu Ta‐Jo , Liu Shur‐Fen , Jeng Jhy‐Long
Published: December 2009

The peeling behavior of polyimide film coated on steel substrates was experimentally investigated and compared with existing models. An operating window for peeling, which is defined as a closed domain for steady and defect‐free peeling, is presented in terms of peeling force versus residual solvent content. The window is bounded by two major defects: the film becomes too brittle for peeling at high peeling force, and stick‐slip striation defect appears at low peeling force. There exists a critical residual solvent content below which the adhesion between the polyimide film and the substrate is too strong and then peeling is impossible. Existing models for predicting steady peeling and the onset of peeling defects have been modified and applied to setup the boundaries of the operating window. There also exists another operating window for drying of polyimide and is presented in the form of drying temperature versus film thickness. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Real‐time ultrasonic characterization of the chain orientation of high density polyethylene melts during processing
Authors: Lin Congmei , Wang Shan , Sun Huimin , Li Jiang , Guo Shaoyun
Published: December 2009

In an attempt to understand the relationships between the evolution of ultrasonic signal and the change of molecular structure during processing, shear‐induced chain orientation and its subsequent disorientation of high‐density polyethylene (HDPE) melts with different melt indices were studied using a noninvasive and nondestructive ultrasonic technique. The molecular structural development during orientation and disorientation of these melts was manifested in the ultrasonic velocity. Two models were developed to describe the relaxation processes of orientation and disorientation, respectively. The effects of shear rate and temperature on the maximal degree of orientation and the relaxation time of orientation and disorientation were also explored. These results from the ultrasonic measurements were compared with ones obtained through rheological measurements, X‐ray diffraction (XRD), and infrared dichroism measurements. The experimental results indicated that the ultrasonic technique was sensitive and promising for the real‐time monitoring of the evolution of molecular structure during polymer processing. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
The processing of polypropylene cast films. I. Impact of material properties and processing conditions on film formation
Authors: Aniunoh Kenneth , Harrison Graham M.
Published: December 2009

Material properties have a significant impact on the response of polymers to industrial flow processes such as film casting. During film casting, molten polymer is extruded through an (approximately) rectangular die and then cooled rapidly. Subsequent biaxial stretching can be employed to manipulate the film properties. In this work, we investigate the effect of polymer viscosity (molecular weight), draw ratio, and die temperature on polypropylene film formation. We measure the width, two components of the velocity vector, and the temperature profiles throughout the film web. The polymer rheology and the die temperature affect the film geometry and temperature profiles in the air‐gap. The magnitude of the machine direction velocity component depends on both the machine and transverse position in the film. The velocity shows a maximum at the centerline and decreases toward the film edge. The measured transverse velocity component, a consequence of the film neck‐in, is seen to decrease from the film edges to the centerline. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Formation and characterization of polyethylene blends for autoclave‐based expanded‐bead foams
Authors: Behravesh Amir H. , Park Chul B. , Lee Eung K.
Published: December 2009

Blends of linear‐low‐density polyethylene (LLDPE), low‐density polyethylene (LDPE), and high‐ density polyethylene (HDPE) were foamed and characterized in this research. The goal was to generate clear dual peaks from the expanded polyethylene (EPE) foam beads made from these blends in autoclave processing. Three blends were prepared in a twin‐screw mixing extruder at two rotational speeds of 5 and 50 rpm: Blend1 (LLDPE with 20 wt% HDPE), Blend 2 (LLDPE with 20 wt% LDPE), and Blend 3 (LLDPE with 10 wt% HDPE and 10 wt% LDPE). The differential scanning calorimetric (DSC) measurement was taken at two cooling rates: 5 and 50°C/min. Although no dual peaks were present, the results showed that blending with HDPE has a more noticeable effect on the DSC curve of LLDPE than blending with LDPE. Also, the rotational speed and cooling rate affected the shape of the DSC curves and the percentage area below the onset point. The DSC characterization of the batch foamed blends revealed multiple peaks at certain temperatures, which may be mainly due to the annealing effect during the gas saturation process. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Model identification of a twin screw extruder for thermoplastic vulcanizate (TPV) applications
Authors: Trifkovic M. , Sheikhzadeh M. , Choo K. , Rohani S.
Published: December 2009

Multi‐input multi‐output (MIMO) models of a twin‐screw co‐rotating extruder for thermoplastic vulcanizate (TPV) are developed using the process identification techniques. The process inputs are screw speed (SS) and barrel temperature (WT). The three outputs are motor load (ML), melt temperature (MT), and melt pressure (MP). Two appropriate rubbers for TPV applications with different physical and mechanical properties are used for the experimentation. The process model is obtained from the experimental input–output data using various identification techniques such as least squares and prediction error. Recursive online model identification is performed on the process to update the model parameters in real time. To perform the identification studies, the process data was transferred via OPC server from the local PLC (Programmable Logic Controller) to the Advanced Control and Identification toolbox in MATLAB software. The effect of rubber properties and two curative agents (Peroxide and Phenolic) in the TPV experiment are studied on the final identified models. This comprehensive model identification study provided sufficient accurate models for further model based process analysis and control for TPV applications. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
BIPV: merging the photovoltaic with the construction industry
Authors: Pagliaro Mario , Ciriminna Rosaria , Palmisano Giovanni
Published: December 2009

BIPV (Building Integrated Photovoltaics) is a multifunctional technology that unifies the photovoltaic module with the overall building outer surface providing the building with several new functions while producing a portion or total building electricity usage. Increasing the aesthetic, functional and environmental value of a building at a much lower cost than in the recent past, new PV technologies will soon originate a market growth as intense as the growth of traditional PV market has been in the last 5 years. Copyright © 2009 John Wiley & Sons, Ltd.

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Separation of local bulk and surface recombination in crystalline silicon from luminescence reabsorption
Authors: Giesecke J. A. , Kasemann M. , Schubert M. C. , Würfel P. , Warta W.
Published: December 2009

Spontaneous photoemission of crystalline silicon provides information on excess charge carrier density and thereby on electronic properties such as charge carrier recombination lifetime and series resistance. This paper is dedicated to separating bulk recombination from surface recombination in silicon solar cells and wafers by exploiting reabsorption of spontaneously emitted photons. The approach is based on a comparison between luminescence images acquired with different optical short pass filters and a comprehensive mathematical model. An algorithm to separate both front and back surface recombination velocities and minority carrier diffusion length from photoluminescence (PL) images on silicon wafers is introduced. This algorithm can likewise be used to simultaneously determine back surface recombination velocity and minority carrier diffusion length in the base of a standard crystalline silicon solar cell from electroluminescence (EL) images. The proposed method is successfully tested experimentally. Copyright © 2009 John Wiley & Sons, Ltd.
Screen printing metallization of boron emitters
Authors: Lago R. , Pérez L. , Kerp H. , Freire I. , Hoces I. , Azkona N. , Recart F. , Jimeno J. C.
Published: December 2009

This paper analyzes the influence of the composition of screen printing metal pastes on contacting boron emitters for crystalline silicon solar cells, optimized on the basis of commercial Ag‐paste Ferro 3347 by adding silicon and aluminum. Aluminum provides a lower contact resistance, while silicon prevents the spiking and alloying of aluminum with the silicon of the substrate. The best pastes have turned out to be high Si‐concentrated, which have provided a final specific contact resistance of 3–4 mΩ cm2on screen printed boron emitters diffused at 1000°C for 8 min, with shunt conductance lower than 0.6 mS/cm2. The final fill factors have been better than 77.5% and open circuit voltages have exceeded 605 mV on Czochralski (Cz)ntype 0.7 Ω cm solar cells. These results have proven the feasibility of our screen printing process forp+nn+structures. Copyright © 2009 John Wiley & Sons, Ltd.
Information Systems Project Manager Soft Competencies: A Project-Phase Investigation
Authors: Skulmoski Gregory J. , Hartman Francis T.
Published: December 2009

This article investigates the soft competencies by project phase that information systems (IS) project managers require for project success. The authors conducted 33 qualitative interviews to collect data from a sample of 22 IS project managers and business leaders located in Calgary, Alberta, Canada. The authors identified the key competencies for each of the IS project phases (initiation, planning, implementation, and close-out). The competencies were sorted into competency categories: personal attributes (e.g., eye for details), communication (e.g., effective questioning), leadership (e.g., create an effective project environment), negotiations (e.g., consensus building), professionalism (e.g., lifelong learning), social skills (e.g., charisma), and project management competencies (e.g., manage expectations). Each of the most important competencies is discussed and interconnections among competencies identified. How this research can be used by the practitioner and academic communities and the broader implications of this research are examined.
Non‐Destructive Sub‐Surface Chemical Characterization of Air‐Exposed Plasma Polymers by Energy‐Resolved XPS
Authors: Girard‐Lauriault Pierre‐Luc , Retzko Iris , Swaraj Sufal , Matsubayashi Nobuyuki , Gross Thomas , Mix Renate , Unger Wolfgang E. S.
Published: December 2009

Plasma polymers containing oxygen‐ and nitrogen‐based surface chemistries were prepared from allyl alcohol, allylamine and acrylic acid. Established selective chemical derivatisation procedures with trifluoroacetic anhydride (TFAA) and 4‐trifluoromethyl benzaldehyde (TFBA) were used to determine alcohols and amines, respectively. Samples were analysed by energy‐resolved XPS (ERXPS), enabling XPS depth resolution. We demonstrated that slightly aged plasma polymers prepared from allyl alcohol and allylamine present a homogeneous sub‐surface chemistry within the range of the XPS information depth (≈10 nm); this was clearly not the case for their acrylic acid counterparts. Furthermore, it is shown that standard derivatisation reactions result in homogeneous changes of the chemistry.

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Characterization of spin crossover crystal surface by AFM
Authors: Chong C. , Berini B. , Boukheddaden K. , Codjovi E. , Linarès J. , Garcia Y. , Naik A. D. , Varret F.
Published: December 2009

Imaging nano‐domains in spin crossover (SCO) compounds remains so far an unreached goal. We report on the first AFM tapping‐mode investigation of SCO single crystals, performed at room temperature with the well known mononuclear compound [Fe(ptz)6](BF4)2 (ptz = 1‐propyl‐tetrazole) and the trinuclear supramolecular compound [Fe3(hyetrz)6(H2O)6](CF3SO3)6 (hyetrz = 4‐(2′‐hydroxyethyl)‐1,2,4‐triazole) which shows a gradual spin conversion centred at room temperature. The natural surface of the former crystal revealed a volatile coating of the scanned area attributed to the transport of adsorbed water under the effect of interaction with the AFM tip. The second one showed astonishing leopard‐skin patterns assigned to the effect of atmospheric humidity on this hygroscopic compound. Their origin is discussed. We suggest the use of fluid coating layers as a general method for revealing the nano‐patterning of physical properties (e.g. like‐spin domains) at the surface of dielectric materials.

AFM‐tapping images of [Fe3(hyetrz)6(H2O)6](CF3SO3)6 at room temperature and ambient atmosphere.

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Electronic ferroelectricity, charge ordering and structural phase transitions in LuFe2O4(LuFeO3)n (n = 0 and 1)
Authors: Yang Huaixin , Zhang Ying , Qin Yuanbin , Ma Chao , Tian Huanfan , Li Jianqi
Published: December 2009

The nature of the charge order, multiferroic features, and structural phase transitions in LuFe2O4(LuFeO3)n (n = 0 and 1) materials have been extensively investigated. In situ transmission electron microscopy (TEM) investigations on LuFe2O4 (n = 0) show the presence of well‐defined charge‐ordered states at low temperatures that could give rise to a notable ferroelectric polarization. Measurements of the structural and physical properties on LuFe2O4(LuFeO3)n (n = 1) demonstrate that the intercalation of the LuFeO3‐block could lead to visible changes in the dielectric properties and the charge ordering (CO) features. Measurements of ferroelectric properties suggest that Mn substitution for Fe in Lu2Fe2Fe1–xMnxO7 (0 < x ≤ 0.86) can notably suppress the conducting leakage current and results in clear hysteresis loops in the polarization–electric field switching curves.
Investigation of graphene–SiC interface by nanoscale electrical characterization
Authors: Sonde Sushant , Giannazzo Filippo , Raineri Vito , Rimini Emanuele
Published: December 2009

We have carried out an investigation of graphene/4H‐SiC (0001) interface by nanoscale current transport measurements. Graphene was deposited by mechanical exfoliation of HOPG. Novel Scanning Probe Current Mapping and Scanning Probe Current Spectroscopy are found to be useful for non‐destructive characterization of graphene. Presence of graphene lowers Schottky barrier height on 4H‐SiC (0001). Observed barrier heights (0.8 ± 0.1 eV) are comparable but higher than reported in literature for 6H‐SiC (0001). Current mapping of graphene deposited on 4H‐SIC(0001). Highly conductive regions in the current maps correspond to graphene in the morphological maps.

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Structure and stability of cub‐Pr2O3 films on Si(111) under post deposition annealing conditions
Authors: Gevers S. , Weisemoeller T. , Zimmermann B. , Deiter C. , Wollschläger J.
Published: December 2009

Ultra thin heteroepitaxial Pr2O3 films on Si(111) were characterized by X‐ray diffraction and X‐ray reflectometry to determine the film and interface structure. These results exhibit two oxide phases within the praseodymia film after preparation which can be assigned to different oxygen stoichiometries. After post deposition annealing of the films at different temperatures up to 600 °C the surface was studied by spot profile analysis low energy electron diffraction, with regard to the stability of the film surface.

The results show that terraces with mono‐atomic step heights and mosaics can be found at the film surfaces after annealing at 300 °C. Higher annealing temperatures do not cause further changes of structure and morphology except of a slight increase of the mosaic spread due to lateral strain effects within the oxide film. These results indicate that the films are stable at temperatures as high as 600 °C. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AlInGaN UV‐C photodetectors with an insertion layer of high work function metal
Authors: Lee Han Cheng , Su Yan Kuin , Lin Jia Ching , Huang Chun Yuan , Cheng Yi Cheng , Chang Kuo Jen
Published: December 2009

Aluminum indium gallium nitride (AlInGaN) metal‐insulator‐semiconductor (MIS) UV‐C photodetectors (PDs) were fabricated using a Ni/Pd/Au contact and a Ni/Au contact. With the inserting of the high work function metal (palladium, Pd), compared with the conventional Ni/Au contact, the multilayer Ni/Pd/Au contact can significantly reduce the dark current. The dark current of UV‐C AlInGaN PDs with a multilayer Ni/Pd/Au contact can be relatively improved by 59.5%. Under the 5 V applied bias, the photo/dark current ratio of PDs with a conventional Ni/Au contact and a multilayer Ni/Pd/Au contact were 9.2 and 4.2×102, respectively. Furthermore, the responsivity of UV‐C AlInGaN PDs (280 nm) with a multilayer Ni/Pd/Au contact can be achieved to the value of 12.7 mA/W under a bias of 5 V. The UV‐C AlInGaN PDs with a multilayer Ni/Pd/Au contact have a better responsivity and rejection ratio than those of PDs with a conventional Ni/Au contact. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dissociative and molecular adsorption of water on α ‐Al2O3(0001)
Authors: Wippermann S. , Schmidt W. G. , Thissen P. , Grundmeier G.
Published: December 2009

A systematic analysis of the adsorption of water monomers, small water clusters and water thin films on α ‐Al2O3(0001) surfaces on the basis of density functional theory calculations is performed. In agreement with most existing studies, our calculations favor the dissociative adsorption for low coverages.

For water‐rich conditions, however, the formation of hexagons of alternating dissociatively and molecularly adsorbed water monomers is predicted. Accordingly, the adsorption energy per water molecule decreases from about 1.5 eV for single adsorbed molecules to about 1.2 eV for thin films. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of dispersion interactions on the adsorption of PTCDA on Ag(110)
Authors: Scholz Reinhard , Abbasi Afshin
Published: December 2009

The interaction of PTCDA with Ag(110) is analysed with second order Møller‐Plesset perturbation theory (MP2), including the main part of the dispersion interactions at an ab initio level. On rigid substrate clusters, the optimized adsorbate geometry consists of a nearly flat perylene core, surrounded by carboxylic oxygens closer to the substrate, but with anhydride atoms at a larger height. The average height of the carbon core is found at 2.68 Å, in excellent agreement with the value of 2.59 Ädetermined in recent X‐ray standing wave measurements. In sharp contrast to the rather flat MP2 geometry, the lack of dispersion interactions in density functional theory (DFT) results in an unrealistic bent adsorbate geometry. The calculated core level shifts and the vibrational fingerprint reproduce the observed trends. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Protection of human HepG2 cells against oxidative stress by the flavonoid epicatechin
Authors: Martín María Angeles , Ramos Sonia , Mateos Raquel , Izquierdo‐Pulido María , Bravo Laura , Goya Luis
Published: December 2009

Flavanols, such as epicatechin (EC), constitute an important part of the human diet; they can be found in green tea, grapes and cocoa and possess different biological activities such as antioxidant, anti‐inflammatory and anticarcinogenic. This study investigated the potential chemo‐protective effect of EC against oxidative stress induced by tert‐butylhydroperoxide (t‐BOOH) on human HepG2 cells. Cell viability by lactate dehydrogenase assay and markers of oxidative status: reduced glutathione (GSH), malondialdehyde (MDA), reactive oxygen species (ROS), glutathione peroxidase (GPx) and glutathione reductase (GR) were evaluated. Pretreatment of cells with EC for 20 h prevented the enhanced cell damage and GPx and GR activities as well as the decrease in GSH induced by t‐BOOH. The increased ROS generation induced by t‐BOOH was also partly prevented by a pretreatment for 20 h with EC. In addition, pretreatment of cells with EC for 20 h recovered the t‐BOOH‐induced MDA concentration to control values. A pretreatment for 2 h with EC did not reduce cell damage but partly recovered GSH, reduced ROS levels and muffled the increase of GPx and GR after exposure to t‐BOOH. Treatment of HepG2 cells with concentrations of EC in the micromolar range confers a significant protection against oxidative stress. Copyright © 2009 John Wiley & Sons, Ltd.
Pharmacological basis for the medicinal use ofZanthoxylum armatumin gut, airways and cardiovascular disorders
Authors: Gilani Syed Naeemuddin , Khan Arif‐ullah , Gilani Anwarul Hassan
Published: December 2009

This study describes the gut, airways and cardiovascular modulatory activities ofZanthoxylum armatumDC. (Rutaceae) to rationalize some of its medicinal uses. The crude extract ofZanthoxylum armatum(Za.Cr) caused concentration‐dependent relaxation of spontaneous and high K+(80 mM)‐induced contractions in isolated rabbit jejunum, being more effective against K+and suggestive of Ca++antagonist effect, which was confirmed when pretreatment of the tissues with Za.Cr shifted Ca++concentration‐response curves to the right, like that caused by verapamil. Za.Cr inhibited the castor‐oil‐induced diarrhea in mice at 300–1000 mg/kg. In rabbit tracheal preparations, Za.Cr relaxed the carbachol (1 μM) and high K+‐induced contractions, in a pattern similar to that of verapamil. In isolated rabbit aortic rings, Za.Cr exhibited vasodilator effect against phenylephrine (1 μM) and K+‐induced contractions. When tested in guinea pig atria, Za.Cr caused inhibition of both atrial force and rate of spontaneous contractions, like that caused by verapamil. These results indicate thatZanthoxylum armatumexhibits spasmolytic effects, mediated possibly through Ca++antagonist mechanism, which provides pharmacological base for its medicinal use in the gastrointestinal, respiratory and cardiovascular disorders. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of Echinacea extracts on macrophage antiviral activities
Authors: Senchina David S. , Martin Aisha E. , Buss Janice E. , Kohut Marian L.
Published: December 2009

Type I interferons are a class of cytokines synthesized by leukocytes such as macrophages that limit viral replication. We hypothesized that one mechanism whereby Echinacea spp. extracts may enhance immunity is through modulating interferon‐associated macrophage pathways. We used herpes simplex viral infection in the murine macrophage cell line RAW264.7 and monitored virus‐induced cell death, interferon secretion, and two intracellular proteins that indicate activation of interferon pathways. Cells were incubated with control media or extracts from four different species (E. angustifolia, E. purpurea, E. tennesseensis, E. pallida). Cells incubated with extracts prior to infection showed very modest enhancement of viability, and no increase in the secretion of interferons α or β as compared to control cells. Virus‐infected macrophages treated with extracts from E. purpurea showed a small (<2‐fold) induction of guanylate binding protein (GBP) production, but no effect of extracts from other species was observed. In virus‐infected cells, all the extracts increased the amount of inducible nitric oxide synthase (iNOS) protein, and this effect varied by type of extraction preparation. Together, these results suggest that any potential antiviral activities of Echinacea spp. extracts are likely not mediated through large inductions of Type I interferon, but may involve iNOS. Copyright © 2009 John Wiley & Sons, Ltd.
Pycnogenol® treatment of acute hemorrhoidal episodes
Authors: Belcaro Gianni , Cesarone Maria Rosaria , Errichi Bruno , Di Renzo Andrea , Grossi Maria Giovanna , Ricci Andrea , Dugall Mark , Cornelli Umberto , Cacchio Marisa , Rohdewald Peter
Published: December 2009

We investigated the efficacy of orally and topically applied Pycnogenol® for the management of acute hemorrhoidal attacks in a controlled, randomized study with 84 subjects. Within less than 48 h of onset of an acute attack, patients were enrolled and signs and symptoms were scored. This evaluation was repeated after seven days' treatment and again seven days following treatment cessation. The decrease in scores was significantly more pronounced in the Pycnogenol®‐treated groups than in the control group given placebo (p < 0.05), showing the efficacy of Pycnogenol® for relieving signs and symptoms of acute external hemorrhoids. In a group of patients given topical (0.5%) Pycnogenol® in addition to oral Pycnogenol® the improvement in symptoms set in significantly faster and was more pronounced. The most prominent symptom, hemorrhoidal bleeding, was completely absent in all patients treated with Pycnogenol® for seven days and also at the 14 days follow‐up. In contrast, bleedings were still observed in the control group during the two weeks follow‐up. This study indicates that Pycnogenol®, both in oral and in topical form, is effective for controlling this common, disabling health problem. The application of Pycnogenol® eases the management of acute hemorrhoidal attacks and help avoid bleedings. Copyright © 2009 John Wiley & Sons, Ltd.
In vitro antiviral activity of neem (Azardirachta indica L.) bark extract against herpes simplex virus type‐1 infection
Authors: Tiwari Vaibhav , Darmani Nissar A , Yue Beatrice Y. J. T. , Shukla Deepak
Published: December 2009

Herpes simplex virus type 1 (HSV‐1) causes significant health problems from periodical skin and corneal lesions to encephalitis. We report here that an aqueous extract preparation from the barks of neem plant Azardirachta indica acts as a potent entry inhibitor against HSV‐1 infection into natural target cells. The neem bark extract (NBE) significantly blocked HSV‐1 entry into cells at concentrations ranging from 50 to 100 μg/ml. The blocking activity of NBE was observed when the extract was pre‐incubated with the virus but not with the target cells, suggesting a direct antiHSV‐1 property of the neem bark. Further, virions treated with NBE failed to bind the cells which implicate a role of NBE as an attachment step blocker. Cells treated with NBE also inhibited HSV‐1 glycoprotein‐mediated cell–cell fusion and polykaryocytes formation suggesting an additional role of NBE at the viral fusion step. These findings open a potential new avenue for the development of NBE as a novel antiherpetic microbicide. Copyright © 2009 John Wiley & Sons, Ltd.
Propolis immunomodulatory action in vivo on Toll‐like receptors 2 and 4 expression and on pro‐inflammatory cytokines production in mice
Authors: Orsatti C. L. , Missima F. , Pagliarone A. C. , Bachiega T. F. , Búfalo M. C. , Araújo J. P. , Sforcin J. M.
Published: December 2009

Propolis is a bee product and its immunomodulatory action has been the subject of intense investigation lately. The recent discovery and characterization of the family of Toll‐like receptors (TLR) have triggered a great deal of interest in the field of innate immunity due to their crucial role in microbial recognition and development of the adaptive immune response. This work aimed to evaluate propolis's effect on TLR‐2 and TLR‐4 expression and on the production of pro‐inflammatory cytokines (IL‐1β and IL‐6). Male BALB/c mice were treated with propolis (200 mg/kg) for three consecutive days, and TLR‐2 and TLR‐4 expression as well as IL‐1β and IL‐6 production were assessed in peritoneal macrophages and spleen cells. Basal IL‐1β production and TLR‐2 and TLR‐4 expression were increased in peritoneal macrophages of propolis‐treated mice. TLR‐2 and TLR‐4 expression and IL‐1β and IL‐6 production were also upregulated in the spleen cells of propolis‐treated mice. One may conclude that propolis activated the initial steps of the immune response by upregulating TLRs expression and the production of pro‐inflammatory cytokines in mice, modulating the mechanisms of the innate immunity. Copyright © 2009 John Wiley & Sons, Ltd.
Modulatory effects of curcumin and resveratrol on lung carcinogenesis in mice
Authors: Malhotra Anshoo , Nair Praveen , Dhawan D. K.
Published: December 2009

The aim of the present study is to explore the chemopreventive potential of curcumin and resveratrol during promotional phase of benzo(a)pyrene (BP) induced lung carcinogenesis in mice. The mice were segregated into five groups which included normal control, BP‐treated, BP+curcumin‐treated, BP+resveratrol‐treated and BP+curcumin+resveratrol‐treated groups. The BP treatment resulted in a significant increase in the levels of lipid peroxidation (LPO). On the other hand, reduced glutathione (GSH) levels and the activities of superoxide dismutase (SOD) were found to be significantly decreased following BP treatment. Administration of curcumin to BP‐treated mice decreased the levels of LPO significantly. Further, treatment of resveratrol to BP‐treated mice significantly elevated the activities of SOD. Combined treatment of curcumin and resveratrol, kowever, showed significant improvement in LPO and GSH levels as well as in the activities of SOD. Histo‐architectural studies showed well‐differentiated signs of lung carcinogenesis following BP administration to mice. Although treatments with resveratrol and curcumin given separately to BP‐treated mice showed appreciable improvement in the histo‐architecture of the lung, combined treatment resulted in a noticeable improvement in the lung histo‐architecture. Copyright © 2009 John Wiley & Sons, Ltd.
Efficacy of blackcurrant oil soft capsule, a Chinese herbal drug, in hyperlipidemia treatment
Authors: Fa‐lin Zhao , Zhen‐yu Wu , Yan Hou , Tao Zhang , Kang Li
Published: December 2009

Blackcurrant oil soft capsule (BOSC) is an effective and safe herbal medicine for the treatment of hyperlipidemia and has been approved for the market in China. No studies have been performed, however, to confirm whether BOSC is effective in reducing the serum lipid level in a large‐scale ordinary or special patient population. In this study, we conducted an observational study at five investigative sites that was designed to further investigate the efficacy of BOSC on serum lipid level lowering in a large‐scale target patient population and include a relative factors analysis for the serum lipid decrease. Serum total cholesterol (TC), triglycerides (TGs) and high density lipoprotein‐cholesterol (HDL‐C) were measured before and after drug administration. TC and TGs were detected by enzymatic analysis, while HDL‐C was detected by PTA‐Mg2+ precipitation. A total of 2,154 dyslipidemic patients were recruited and took BOSC 1.8 g b.i.d. every day for 6 weeks. In terms of serum lipid lowering, the overall curative rate was 37.19%, the marked effective rate was 52.28% and the effective rate was 79.06%. The corresponding effective rate of TC, TGs and HDL‐C was 80.98%, 78.28% and 67.07%, respectively. Multivariate analyses with adjustment for centers, gender and age indicated that BOSC was almost ineffective in patients with a disease course <36 months (OR: 0.467, 95% CI: 0.359–0.607) and was effective in mild hyperlipidemia (OR: 3.176, 2.535–3.978) and in subjects with lower BMIs (BMI <24: 3.472, 2.171–5.552; BMI between 24 and 28: 2.310, 1.832–2.911 compared with BMI ≥ 28). No serious adverse events were reported during the study period. Therefore, we conclude that BOSC is effective in decreasing TC and TG levels and in increasing the serum HDL‐C level, especially in mildly hyperlipidemic patients and those with a lower BMI. Moreover, because it is a natural raw material, BOSC may be safer and more effective in the treatment of hyperlipidemia. Copyright © 2009 John Wiley & Sons, Ltd.
Recognition of viral nucleic acids in innate immunity
Authors: Yoneyama Mitsutoshi , Fujita Takashi
Published: December 2009

Viral infections are detected by sensor molecules, which initiate innate antiviral responses, including the activation of type I interferons (IFNs) and proinflammatory cytokines. These cytokines are responsible for not only inhibiting viral replication in infected cells but also regulating the induction of adaptive immunity, leading to the swift eradication of viruses. Recent advances in the identification of pathogen receptors in the innate immune system have revealed that distinct types of sensors play a role in the detection of viral nucleic acids in different ways; Toll‐like receptors (TLRs), which detect viral DNA or RNA in endosomal compartments in immune cells, retinoic acid inducible gene‐I (RIG‐I)‐like receptors (RLRs), which recognise viral RNA in the cytoplasm, and DNA sensors, which detect cytoplasmic viral DNA. Since these sensors have to exclusively recognise viral infections, it is intriguing to understand how they distinguish self nucleic acids from foreign viral ones. Here, we review the current knowledge of the recognition of viral nucleic acids by these sensor molecules and the signal transduction machinery. Copyright © 2009 John Wiley & Sons, Ltd.
Defective interfering viruses and their potential as antiviral agents
Authors: Marriott A. C. , Dimmock N. J.
Published: December 2009

Defective interfering (DI) virus is simply defined as a spontaneously generated virus mutant from which a critical portion of the virus genome has been deleted. At least one essential gene of the virus is deleted, either in its entirety, or sufficiently to make it non‐functional. The resulting DI genome is then defective for replication in the absence of the product(s) of the deleted gene(s), and its replication requires the presence of the complete functional virus genome to provide the missing functions. In addition to being defective DI virus suppresses production of the helper virus in co‐infected cells, and this process of interference can readily be observed in cultured cells. In some cases, DI virus has been observed to attenuate disease in virus‐infected animals. In this article, we review the properties of DI virus, potential mechanisms of interference and progress in using DI virus (in particular that derived from influenza A virus) as a novel type of antiviral agent. Copyright © 2009 John Wiley & Sons, Ltd.
Singular ℋ︁2 control of discrete‐time systems: From frequency to time domain
Authors: Stefanovski Jovan
Published: December 2009

Necessary and sufficient conditions for the existence of a minimizing discrete‐time ℋ︁2 control, when assumptions are the internal stabilizability and left‐ and right‐invertibility of transfer matrices G12 and G21, are presented. Unlike the existing approach with a transformation into a disturbance decoupling problem with a measurement feedback and internal stability, we use a direct approach: from frequency to time domain. The first main result gives a necessary and sufficient existence condition for ℋ︁2 control: that a minimal realization of the infimal controller is stabilizing. The second main result presents a realization of an optimal controller that has a state observer form, identical to the form of the regular case, except that the state‐feedback gain matrix and the observer gain matrix are replaced by some stabilizing matrices. Copyright © 2009 John Wiley & Sons, Ltd.
Angioarchitecture of squamous cell carcinoma from hamster buccal pouch: a scanning electron microscopy study
Authors: De Oliveira Laura Beatriz Oliveira , Bampi Vinícius Faccin , Gomes Carolina Ferreira , De Souza Maria Antonieta Lopes
Published: December 2009

Tumoral angiogenesis has been widely studied by histochemical analysis but little has been done regarding morphology of these new vessels. The objective of this study was to perform a qualitative analysis of the angiogenic response to chemical induction with dimethylbenzanthracene (DMBA) and carbamide peroxide of squamous cell carcinoma in pouches of Syrian hamsters after different periods of treatment. Twenty‐four Syrian golden hamsters, divided into three groups of eight animals each, had their right jugal pouches treated with a 5% DMBA solution three times a week and a 10% carbamide peroxide two times a week for 55, 70 and 90 days. The left pouch was considered the control. After tumor induction, five animals in each group had their pouches prepared for analysis under scanning electron microscopy and three animals for analysis under light microscopy. The control pouches showed a vascular system composed by few main vessels running parallel to the longest axis of the pouch with some branches. In the pouches submitted to tumor induction, a well‐differentiated squamous cell carcinoma was present since 55 days induction in all samples. The new vascular system showed the presence of many tortuous vessels and the majority of them were veins and capillaries. Terminal loops were extremely sinuous adopting a glomerular or corkscrew shape. These tumor vessels are different from normal vessels, presenting irregular diameters, outpouchings and constrictions. Angiogenesis of sprouting and intussusceptive kind could be identified in the tumor pouches, and they were more frequent as the tumor developed. SCANNING 31: 188–194, 2009. © 2009 Wiley Periodicals, Inc.
Erneuerung des Innenkorrosionsschutzes der Triebwasserleitungen im Pumpspeicherkraftwerk Markersbach
Authors: Gelhaar Andreas , Schneider Andreas , Lang Ingo
Published: December 2009

Im Pumpspeicherwerk Markersbach der Vattenfall Europe Generation AG wurde 2007 und 2008 der Korrosionsschutz der beiden Triebwasserleitungen (Durchmesser ca. 6 m) und Niederdruck‐ Verteilerrohrleitungen (Durchmesser bis zu 8,7 m) erneuert. Die zu bearbeitende Stahloberfläche betrug ca. 50000 m2. Die Korrosionsschutzmaßnahme beinhaltete das Abstrahlen der Altbeschichtung mit Herstellung des Oberflächenvorbereitungsgrades Sa 2 1/2 und den Neuaufbau eines 4‐schichtigen Beschichtungssystems. Durch die objektspezifischen Verhältnisse mit einem Gefälle der ca. 1000 m langen Triebwasserleitung von bis zu 58 % war für die Durchführung der Arbeiten der Einsatz eines speziellen Befahrwagens erforderlich. Die Herstellung von für Korrosionsschutzarbeiten geeigneten klimatischen Bedingungen erfolgte durch das Einleiten von entfeuchteter und erwärmter Luft. Der folgende Beitrag beschreibt die Durchführung der Korrosionsschutzarbeiten sowie deren Qualitätssicherung und geht auf bei der Bauausführung aufgetretene Besonderheiten ein.

Refreshment of the inner corrosion protection of the works water pipelines of the hydro storage pump power plant Markersbach.

The corrosion protection of the works water pipelines (diameter approx. 6 m) and the low pressure distributor pipeline (diameter up to 8,7 m) of the hydro storage pump power plant Markersbach of Vattenfall Europe Generation AG was modernised in 2007 and 2008. The steel surface to be worked on constituted approx. 50000 m2. The corrosion protection measure comprised the blasting of the old coating and the creation of the surface preparation level of Sa 2 1/2 and the rebuilding of a 4‐layer coating system. Due to the object‐specific conditions of approx. 1000 m long works water pipeline with an incline of up to 58 %, the use of a special carriage was necessary for the accomplishment of the works. The creation of suitable climatic conditions for the corrosion protection works was achieved via the intake of dehumidified and pre‐heated air. This article describes the accomplishment of the corrosion protection works as well as their quality assurance and discusses the particularities that occurred during the execution of the construction work.
Vilssteg als Wahrzeichen des Mäandertals
Authors: Bauer Martin
Published: December 2009

Im Zuge einer städtebaulichen Maßnahme im niederbayerischen Vilstal wurde zur Aufwertung des Flussgebietes eine Fußgängerbrücke errichtet. Mit einer filigranen abgespannten Konstruktion gelang ein Bauwerk, das sich sowohl landschaftlich in das Gelände einfügt als auch den Erschließungsgedanken von Schule und Sportgelände erfüllt. Im nachfolgenden Beitrag werden die Geschichte des Vilsstegs sowie dessen Konstruktion und Bau näher erläutert.

Vilssteg – a pedestrian bridge as a landmark for the Bavarian Mäandertal.

In the course of an urban development in the Lower Bavarian Vilstal a pedestrian bridge has been erected to upvalue the surroundings of the river. With a filigree guyed construction, a building structure has been succeeded which fits scenically into the terrain as well as it fulfils the development idea of school and sports ground. The following paper comments on the history of the Vilssteg and its construction.
Hangar für drei Großraumflugzeuge
Authors: Kraus Matthias , Niebuhr Hans Joachim
Published: December 2009

Am Flughafen Düsseldorf International ist ein neuer Hangar, die Halle 7, gebaut worden. Es handelt sich hierbei um das größte Bauprojekt der Flughafengesellschaft seit der Terminalerweiterung in den Jahren von 1998 bis 2004. Mit Abmessungen von ca. 210 m x 90 m ist die Flugzeughalle die größte am Düsseldorf Airport beziehungsweise in Nordrhein‐Westfalen. Sie bietet zeitgleich Platz für drei Großraumflugzeuge. Im Wesentlichen ist das Haupttragwerk als reine Stahlkonstruktion und bei den Stützen auch in Verbundbauweise ausgeführt worden. Neben der Flugzeughalle sind ein zweigeschossiger Anbau mit Lager‐, Aufenthalts‐ und Sozialräumen sowie ein viergeschossiger Bürotrakt mit einem Technikbereich im Keller in Massivbauweise entstanden. Im Folgenden wird die Konstruktion des Hangars vorgestellt, die Anbauten in Massivbauweise sind nicht Bestandteil dieses Beitrages.

Hangar for three wide‐bodied aircrafts.

At Düsseldorf International Airport a new Hangar referred to as Hall 7 has been built. It is the biggest project of the Airport Corporation since the extension of the terminal in the years 1998‐2004. With dimensions of about 210 m width and 90 m depth, the aero plane hangar is the largest one at Düsseldorf Airport and North Rhine‐Westphalia. The building has a maintenance capacity of three wide‐bodied long‐haul aircrafts. The structure is mainly designed as steel construction, although some of the columns are designed as composite members as well. Adjacently behind the hangar a two storey outbuilding with stocking and social rooms and a four storey office building with technical equipment in the basement were built as massive concrete construction. In the following the hangar will be presented, the additional outbuildings are not included in this essay.