bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of tapioca starch‐poly(lactic acid)‐Cloisite NA+ nanocomposite foams
Authors: Lee Siew‐Yoong , Hanna Milford A. 
Published: August 2008

AbstractTapioca starch, poly(lactic acid), and Cloisite NA+ nanocomposite foams, with four clay contents (1, 3, 5, 7, wt %), were prepared by melt‐intercalation method. Selected structural, thermal, physical, and mechanical properties were characterized using X‐ray diffraction (XRD), scanning electron microscopy, differential scanning calorimetry, and an Instron universal testing machine, respectively. XRD results indicated that the 1 wt % nanocomposite foam did not show the characteristic basal reflection of the nanoclay. The 3, 5, and 7 wt % nanocomposite foams produced a mixture of intercalated and tactoid structures. The d001‐spacing of 3, 5, 7 wt % nanocomposite foams produced increases of 11.40, 11.15, and 10.67 Å, respectively, compared to that of the pristine clay. The morphological study showed that the nanocomposite foams exhibited a noticeably reduced cell size, more compact cells, and increased cell density. Increasing clay content caused a decrease in melting temperature (Tm). Bulk spring index and bulk compressibility were influenced (P < 0.05) significantly with the addition of different amounts of clay. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polymer/carbon nanotube nanocomposites via noncovalent grafting with end‐functionalized polymers
Authors: Lee Sun Hwa , Park Ji Sun , Lim Bo Kyung , Kim Sang Ouk 
Published: August 2008

AbstractPolymer/carbon nanotube nanocomposites were fabricated with end‐functionalized polymers as dispersants. End‐functionalized polymers having amine or carboxylic acid were noncovalently grafted to multiwalled nanotubes (MWNTs). The functional groups of the polymers interacted with the defect sites of purified MWNTs through zwitterionic interactions or hydrogen bonding. This approach provided both an improved dispersion state of MWNTs in an organic solution and polymer matrix and good interfacial adhesion between MWNTs and a matrix. Physical properties, such as the electrical resistivity and mechanical strength, of polystyrene/MWNT nanocomposites were greatly improved through this simple noncovalent functionalization. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Spectroscopic and thermogravimetric analysis of PANI/PPy composite polymer electrode: Its application to electrochemical investigation of pharmaceutical formulation
Authors: Tiwari D. C. , Jain Rajeev , Sharma Shraddha 
Published: August 2008

AbstractThe electrochemical preparation of polyaniline/polypyrrole (PANI/PPy) conducting polymer composite film on Tin oxide glass electrode from an aqueous solution containing a pyrrole monomer, p‐toluenesulphonate electrolyte on to a polyaniline polymer doped with sulfuric acid, and sodium perchlorate is reported. The prepared PANI/PPy composite films were characterized by FTIR spectroscopy, UV–vis spectroscopy, and thermogravimetric analysis and scanning electron microscopy. Optical band gaps of these films were evaluated from UV–vis absorption studies. The optical band gap measurements of both direct and indirect allowed transition, showed a dual band gap for composite film. This type of dual band gaps for a composite polymer film was reported for the first time. The FTIR and UV–vis study showed the composite of PANI/PPy formed through the bond formation between PANI‐PPY and dopant anions. Scanning electron microscopic studies confirmed the formation of composite with increased particle size. The TGA results showed that PANI/PPy polymer composite film was thermally stable than either PANI or PPy films. This PANI/PPy composite polymer electrode was used for cyclic voltammetric investigation of cefpodoxime proxetil drug in pharmaceutical formulation. The cyclic voltammetric data of composite electrode for cefpodoxime proxetil drug are compared with glassy carbon electrode. The current obtained on polymer electrode was around three time than that of glassy carbon electrode. The voltagramm also showed two reduction peaks C1 (∼57 μA) and C2 (∼70.0 μA) at potentials 1.2 and 1.6 V, respectively, at concentration 1 mM, which are absent for glassy carbon electrode. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Formation of silver nanoparticles created in situ in an amphiphilic block copolymer film
Authors: Park Jung Tae , Koh Joo Hwan , Lee Kyung Ju , Seo Jin Ah , Min Byoung Ryul , Kim Jong Hak 
Published: August 2008

AbstractIn this work, silver nanoparticles were synthesized with an amphiphilic diblock copolymer, polystyrene‐block‐poly(1‐vinyl‐2‐pyrrolidone) (PS‐b‐PVP), as a template film. First, microphase‐separated amphiphilic PS‐b‐PVP (70 : 30 wt %) was synthesized through atom transfer radical polymerization. The self‐assembled block copolymer film was used to template the growth of silver nanoparticles by the introduction of a silver trifluoromethanesulfonate precursor and an ultraviolet irradiation process. The in
situ formation of silver nanoparticles with an average size of 4–6 nm within the block copolymer template film was confirmed with transmission electron microscopy, ultraviolet–visible spectroscopy, and wide‐angle X‐ray scattering. Fourier transform infrared spectroscopy also demonstrated the selective incorporation and in
situ formation of silver nanoparticles within the hydrophilic poly(1‐vinyl‐2‐pyrrolidone) domains, which were mostly due to the stronger interaction strength of the silver with the carbonyl oxygens of poly(1‐vinyl‐2‐pyrrolidone) in the block copolymer. This work provides a simple route for the in
situ synthesis of silver nanoparticles within a polymer film. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Investigation of the ultradrawing properties of gel spun fibers of ultra‐high molecular weight polyethylene/carbon nanotube blends
Authors: Yeh Jen‐Taut , Lin Shui‐Chuan , Chen Kan‐Nan , Huang Kuo‐Shien 
Published: August 2008

AbstractThe carbon nanotubes (CNTs) contents, ultrahigh‐molecular‐weight polyethylene (UHMWPE) concentrations and temperatures of UHMWPE, and CNTs added gel solutions exhibited significant influence on their rheological and spinning properties and the drawability of the corresponding UHMWPE/CNTs as‐prepared fibers. Tremendously high shear viscosities (ηs) of UHMWPE gel solutions were found as the temperatures reached 140°C, at which their ηs values approached the maximum. After adding CNTs, the ηs values of UHMWPE/CNTs gel solutions increase significantly and reach a maximum value as the CNTs contents increase up to a specific value. At each spinning temperature, the achievable draw ratios obtained for UHMWPE as‐prepared fibers prepared near the optimum concentration are significantly higher than those of UHMWPE as‐prepared fibers prepared at other concentrations. After addition of CNTs, the achievable draw ratios of UHMWPE/CNTs as‐prepared fibers prepared near the optimum concentration improve consistently and reach a maximum value as their CNTs contents increase up to an optimum value. To understand these interesting drawing properties of the UHMWPE and UHMWPE/CNTs as‐prepared fibers, the birefringence, thermal, morphological, and tensile properties of the as‐prepared and drawn fibers were investigated. Possible mechanisms accounting for these interesting properties are proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Solubility of alkanes in a polystyrene matrix
Authors: Bernardo Gabriel , Vesely Drahosh 
Published: August 2008

AbstractThe solubilities of seven alkanes in a matrix of uncrosslinked polystyrene were measured at several different temperatures. A gravimetric method reported earlier was used to monitor the sorption of the solvents. The experimental measurements showed unambiguously that the solubility of the alkanes diffusing into a polystyrene matrix reached a constant and reproducible value typical for each system and temperature. These values could be interpreted very well with the Flory–Huggins solubility parameter (χ = a(entropic contribution to x) + b(enthalpic contribution to x)/T[absolute temperature in Kelvin (K)]) or with the van't Hoff equation (ln KS = ΔS/R(gas constant) − ΔH/RT, where KS is the equilibrium constant, ΔS is the entropy change, and ΔH is the enthalpy change). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Solubility and phase separation of poly(L,D‐lactide) copolymers
Authors: Rissanen Marja , Puolakka Arja , Nousiainen Pertti , Kellomäki Minna , Ellä Ville 
Published: August 2008

AbstractIn this study, the solubility and precipitation properties of medical‐grade stereocopolymers were investigated. The solubility of the polymers was tested with eight different organic solvents and four nonsolvents. The solubility of poly(L,D‐lactide) stereocopolymers was highly dependent on the L/D ratio of the copolymer. The phase‐separation ability was tested by cloud‐point titration with a solvent and a nonsolvent. The solvent was in all cases dichloromethane, and the nonsolvents were n‐hexane, methanol, ethanol, and isopropyl alcohol. The results showed that n‐hexane was the most efficient nonsolvent. Methanol and ethanol showed quite similar precipitation properties. Isopropyl alcohol was the least efficient nonsolvent of those studied. Also, the L/D ratio of the copolymer had an effect on the precipitation properties. The precipitation happened most easily when the L content was high. The molecular weight of the copolymer had only a slight effect on the phase separation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, characterization, and thermal studies of polyamides and polyimides containing two silarylene units in the main chain
Authors: Tagle L. H. , Terraza C. A. , Leiva A. , Devilat F. 
Published: August 2008

AbstractPolyamides (PAs) and polyimides (PIs) containing two silarylene units were synthesized and characterized by their spectroscopic properties. Bis(4‐aminophenyl)methylphenylsilane was employed as a unique diamine, whereas acid dichloride and dianhydride monomers contained combinations of methyl and phenyl groups bonded to the silicon atom. The PAs were obtained in dimethylformamide solutions, and the PIs were prepared by thermal cyclization of the respective poly(amic acid)s (PAAs). The yields were low (32–51%), and the inherent viscosities for PAAs were slightly higher than the PA values. The low inherent viscosities were indicative of oligomeric species. The thermal stability was also evaluated by thermogravimetric analysis and differential scanning calorimetry analysis. In both series, the glass‐transition temperatures increased with the replacement of methyl groups by aromatic rings according to the lower mobility of the polymeric chain. On the other hand, an increase in the aromatic content also increased the thermal stability of the PAs and PIs, and this was registered through their thermal decomposition temperatures. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Gründung von Offshore‐Windenergieanlagen – Entscheidungshilfen für Entwurf und Bemessung
Authors: Lesny Kerstin 
Published: August 2008

AbstractVon den Investitionskosten eines Offshore‐Windparks entfallen rd. 25% für Herstellung und Installation der Gründungsstrukturen, da die Gründung für die jeweiligen Standortbedingungen innerhalb des Parks ausgelegt werden muss und eine Vorfertigung an Land nur begrenzt möglich ist. Die Entwicklung sicherer aber zugleich wirtschaftlicher Gründungsalternativen ist daher von großer Bedeutung. In diesem Beitrag werden verschiedene aus dem Offshore‐Ingenieurwesen übernommene Gründungskonzepte in einem Systemvergleich einander gegenübergestellt und die Gründungswahl für die vorhandenen Randbedingungen in Nord‐ und Ostsee diskutiert. Danach kommt nicht jede Gründungsvariante für jeden Standort gleichermaßen in Frage. Maßgebliches Kriterium ist vor allem die Baugrundsituation vor Ort, aber auch der damit verbundene Aufwand für Herstellung und Installation.
EMS‐WSV – Ein Erhaltungsmanagementsystem für Verkehrswasserbauwerke
Authors: Kühni Katrin , Bödefeld Jörg , Kunz Claus 
Published: August 2008

AbstractDas Bundeswasserstraßennetz in Deutschland hat einschließlich der dazugehörigen Infrastrukturbauwerke wie z. B. Schleusen, Wehre, Düker, Kanalbrücken, Brücken und Leuchttürme, ein Anlagevermögen von rund 40 Mrd. €. Die Altersstruktur der Verkehrswasserbauwerke wird zunehmend ungünstiger. Bei Schleusen sind mehr als 35% der Bauwerke älter als 80 Jahre, sie haben also ihre bisher vorgesehene Nutzungsdauer überschritten. Voraussetzung für eine technisch sinnvolle und wirtschaftliche Instandhaltung der Ingenieurbauwerke ist ein IT‐gestütztes Erhaltungsmanagementsystem (EMS), basierend auf regelmäßigen Bauwerksinspektionen. Der Beitrag beschreibt die Vorgehensweise der Wasser‐ und Schifffahrtsverwaltung (WSV) im Rahmen der Inspektion der bundeseigenen Verkehrswasserbauwerke und gibt einen Überblick über den Stand der Entwicklung eines Erhaltungsmanagementsystems, das von der Bundesanstalt für Wasserbau (BAW) erarbeitet wird.
Numerische Untersuchungen zur Pfropfenbildung in offenen Profilen in Abhängigkeit des Einbringverfahrens
Authors: Henke Sascha , Grabe Jürgen 
Published: August 2008

AbstractBei der Rammung von offenen Profilen, wie z. B. Rohrprofile, kann sich der Boden im Innern des Profils verspannen und schließlich einen Pfropfen bilden. Dieser Effekt ist für das Einbringen eher hinderlich, jedoch für die Abtragung von Axiallasten nützlich. Es ist aber bislang schwierig vorherzusagen, ob sich in einem gerammten Profil tatsächlich eine Verspannung bzw. ein Pfropfen bildet und wie groß dieser dann ist. Es liegen hierfür lediglich wenige experimentelle Daten vor. In diesem Beitrag werden numerische Untersuchungen vorgestellt, bei denen die Rammung von offenen Stahlbau‐ und Rohrprofilen numerisch untersucht wird. Anhand der horizontalen Spannungen und der Porenzahlverteilung innerhalb der Profile sind Rückschlüsse auf die Neigung der Profile zur Pfropfenbildung in Abhängigkeit des Rammverfahrens möglich. Zudem können anhand der numerischen Ergebnisse vertiefte Kenntnisse über die Mechanismen, die zu einer Pfropfenbildung führen oder diese verhindern, gewonnen werden.
The effect of heating rate onEscherichia colimetabolism, physiological stress, transcriptional response, and production of temperature‐induced recombinant protein: A scale‐down study
Authors: Caspeta Luis , Flores Noemí , Pérez Néstor O. , Bolívar Francisco , Ramírez Octavio T. 
Published: August 2008

AbstractAt the laboratory scale, sudden step increases from 30 to 42°C can be readily accomplished when expressing heterologous proteins in heat‐inducible systems. However, for large scale‐cultures only slow ramp‐type increases in temperature are possible due to heat transfer limitations, where the heating rate decreases as the scale increases. In this work, the transcriptional and metabolic responses of a recombinantEscherichia colistrain to temperature‐induced synthesis of pre‐proinsulin in high cell density cultures were examined at different heating rates. Heating rates of 6, 1.7, 0.8, and 0.4°C/min were tested in a scale‐down approach to mimic fermentors of 0.1, 5, 20, and 100 m3, respectively. The highest yield and concentration of recombinant protein was obtained for the slowest heating rate. As the heating rate increased, the yield and maximum recombinant protein concentration decreased, whereas a larger fraction of carbon skeletons was lost as acetate, lactate, and formate. Compared to 30°C, the mRNA levels of selected heat‐shock genes at 38 and 42°C, as quantified by qRT‐PCR, increased between 2‐ to over 42‐fold when cultures were induced at 6, 1.7, and 0.8°C/min, but no increase was observed at 0.4°C/min. Only small increases (between 1.5‐ and 4‐fold) in the expression of the stress genesspoTandrelAwere observed at 42°C for cultures induced at 1.7 and 6°C/min, suggesting that cells subjected to slow temperature increases can adapt to stress. mRNA levels of genes from the transcription–translation machinery (tufB,rpoA, andtig) decreased between 40% and 80% at 6, 1.7 and 0.8°C/min, whereas a transient increase occurred for 0.4°C/min at 42°C. mRNA levels of the gene coding for pre‐proinsulin showed a similar profile to transcripts of heat‐shock genes, reflecting a probable analogous induction mechanism. Altogether, the results obtained indicate that slow heating rates, such as those likely to occur in conventional large‐scale fermentors, favored heterologous protein synthesis by the thermo‐inducible expression system used in this report. Knowledge of the effect of heating rate on bacterial physiology and product formation is useful for the rational design of scale‐down and scale‐up strategies and optimum recombinant protein induction schemes. Biotechnol. Bioeng. 2009;102: 468–482. © 2008 Wiley Periodicals, Inc.
Quantitative characterization of virus‐like particles by asymmetrical flow field flow fractionation, electrospray differential mobility analysis, and transmission electron microscopy
Authors: Pease Leonard F. , Lipin Daniel I. , Tsai De‐Hao , Zachariah Michael R. , Lua Linda H.L. , Tarlov Michael J. , Middelberg Anton P.J. 
Published: August 2008

AbstractHere we characterize virus‐like particles (VLPs) by three very distinct, orthogonal, and quantitative techniques: electrospray differential mobility analysis (ES‐DMA), asymmetric flow field‐flow fractionation with multi‐angle light scattering detection (AFFFF‐MALS) and transmission electron microscopy (TEM). VLPs are biomolecular particles assembled from viral proteins with applications ranging from synthetic vaccines to vectors for delivery of gene and drug therapies. VLPs may have polydispersed, multimodal size distributions, where the size distribution can be altered by subtle changes in the production process. These three techniques detect subtle size differences in VLPs derived from the non‐enveloped murine polyomavirus (MPV) following: (i) functionalization of the surface of VLPs with an influenza viral peptide fragment; (ii) packaging of foreign protein internally within the VLPs; and (iii) packaging of genomic DNA internally within the VLPs. These results demonstrate that ES‐DMA and AFFFF‐MALS are able to quantitatively determine VLP size distributions with greater rapidity and statistical significance than TEM, providing useful technologies for product development and process analytics. Biotechnol. Bioeng. 2009; 102: 845–855. © 2008 Wiley Periodicals, Inc.
Recombinant mussel adhesive protein as a gene delivery material
Authors: Hwang Dong Soo , Kim Kyoung Ro , Lim Seonghye , Choi Yoo Seong , Cha Hyung Joon 
Published: August 2008

AbstractEfficient target gene delivery into eukaryotic cells is important for biotechnological research and gene therapy. Gene delivery based on proteins, including histones, has recently emerged as a powerful non‐viral DNA transfer technique. Here, we investigated the potential use of a recombinant mussel adhesive protein, hybrid fp‐151, as a gene delivery material, in view of its similar basic amino acid composition to histone proteins, and cost‐effective and high‐level production in Escherichia coli. After confirming DNA binding affinity, we transfected mammalian cells (human 293T and mouse NIH/3T3) with foreign genes using hybrid fp‐151 as the gene delivery carrier. Hybrid fp‐151 displayed comparable transfection efficiency in both mammalian cell lines, compared to the widely used transfection agent, Lipofectamine™ 2000. Our results indicate that this mussel adhesive protein may be used as a potential protein‐based gene‐transfer mediator. Biotechnol. Bioeng. 2009;102: 616–623. © 2008 Wiley Periodicals, Inc.
Plasminogen activator, but not systemic antibiotic therapy, prevents abscess formation in an experimental model of secondary peritonitis
Authors: Buyne O R , Bleichrodt R P , van Goor H , Verweij P E , Hendriks T 
Published: August 2008

Abstract

Background
Intra-abdominal abscesses are sources of recurrent or ongoing abdominal sepsis. They are an important target for prevention and treatment during or after surgical treatment of peritonitis. Experimental data suggest that fibrinolytic therapy may be effective when antibiotics are not.

Methods
Peritonitis was induced via intra-abdominal injection of a faeces and bacteria mixture in male Wistar rats. Surgical debridement was performed after 1 h. Next to untreated controls, animals were treated with antibiotics (ceftriaxone plus metronidazole), recombinant tissue plasminogen activator (rtPA) or both. Abdominal fluid samples were taken at 24, 72 and 120 h for interleukin 6, interleukin 10 and tumour necrosis factor α measurements and cell counts. After 5 days the abdomen was inspected for the presence of abscesses.

Results
Antibiotics did not significantly affect abscess formation. However, giving rtPA significantly reduced the number of rats with abscesses and the abscess load per rat, both in the absence and presence of concomitant antibiotic therapy. No adverse side-effects were observed and no meaningful differences in the local inflammatory response were found.

Conclusion
In this rat model, rtPA consistently reduced abscess formation after surgical treatment of secondary peritonitis. It therefore represents a promising adjuvant to conventional therapy.
Developing programming tools to reach a deeper understanding of advanced programming concepts
Authors: Licea Guillermo , Juárez J. Reyes , Martínez Luis G. , Aguilar Leocundo 
Published: August 2008

AbstractThis article describes the experience and results obtained teaching non‐common Java features, in advanced undergraduate object‐oriented programming courses. The teaching approach proposed helps students to reach a deeper level of programming expertise, while accomplishing specific assignments that integrate a class framework that supports implementation of medium size client–server applications. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 16: 305–314, 2008; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae20127
Reye's and Reye's‐like syndromes
Authors: Pugliese Agostino , Beltramo Tiziana , Torre Donato 
Published: August 2008

AbstractThe review reports various questions about Reye's syndrome and Reye's‐like syndromes. Although there is a significant decrease in the classic Reye's syndrome cases, because of the reduced employment of salicylates in children (salicylate seems to be the most important inducing factor of the syndrome in paediatric subjects affected by viral infection), the problem is still of interest considering the presence of different Reye's‐like forms. All these pathological situations are associated with various aetiologic or predisposing causes that are examined in the text. Particular attention is placed on metabolic disorders, especially of fatty acid metabolism, and also of one amino acid. In fact, a latent form can also be the basis of possible biochemical disturbances induced by various exogenous factors such as viral infections, particularly of the respiratory tract (more rarely of bacterial aetiology), or produced by microbial toxins, or by chemical substances, including some therapeutic drugs. A full discussion of biochemical mechanisms of salicylate‐induced Reye's syndrome is reported. Finally a possible diagnostic differentiation from classic Reye's syndrome and Reye's‐like syndromes plus therapeutic prospects are briefly examined. Copyright © 2008 John Wiley & Sons, Ltd.