bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Encoded Layer‐By‐Layer Coated Microparticles As Protease Sensors
Authors: Stubbe Barbara G. , Gevaert Kevin , Derveaux Stefaan , Braeckmans Kevin , De Geest Bruno G. , Goethals Marc , Vandekerckhove Joel , Demeester Joseph , De Smedt Stefaan C. 
Published: June 2008

AbstractProteases are important pharmaceutical targets for new drugs because of their involvement in numerous disease processes. This study evaluates whether photophysically encoded microparticles carrying fluorescently labeled protease substrates (peptides) at their surface show potential for detecting proteases in a sample. Layer‐by‐layer (LbL) polyelectrolyte coatings, containing a red‐labeled peptidic trypsin substrate, are carefully designed and applied at the surface of the encoded microparticles. The peptide‐loaded LbL coatings lose their red fluorescence upon incubation in a trypsin solution, indicating that LbL‐coated microparticles show potential to screen for the presence of active proteases in biological samples.
Prolactin levels in Western Lowland gorillas
Authors: Laughlin Shannon , Meehan Thomas , Zinaman Michael J. 
Published: June 2008

AbstractHyperprolactinemia is known to cause menstrual irregularity and infertility in humans. However, little is known about the role of prolactin in menstruation and fertility in Western Lowland gorillas. To create a database of prolactin values in gorillas, we have performed immunoassays on serum specimens dating back to 1983 from nine female gorillas at the Brookfield Zoo. We matched these samples with documented behavioral data to correlate menstrual timing. In addition, we ran other reproductive hormones both to aid in determining the phase of the menstrual cycle and to evaluate the effect of the prolactin on suppression of these hormones during the premenarchal and postpartum phases. We found that values for luteinizing hormone, follicle‐stimulating hormone, estradiol and progesterone cycle in very similar patterns to humans. Based on the 59 available samples, prolactin was found to be higher in gorillas than in humans in nearly every phase of the menstrual cycle (range 49.9–93.7 ng/mL) and such levels do not appear to alter the reproductive axis as it does in humans. Thus, prolactin may have a different impact on fertility in gorillas than it does in humans. Am. J. Primatol. 70: 897–900, 2008. © 2008 Wiley‐Liss, Inc.
Proximal femoral anatomy of a sivaladapid primate from the late middle Eocene Pondaung formation (central Myanmar)
Authors: Marivaux Laurent , Beard K. Christopher , Chaimanee Yaowalak , Jaeger Jean‐Jacques , Marandat Bernard , Soe Aung Naing , Tun Soe Thura , Kyaw Aung Aung 
Published: June 2008

AbstractThe postcranial anatomy of the Asian sivaladapid adapiforms is still virtually undocumented, whereas dental remains of these primates have been known for several decades. Little is known about their positional behavior as a result. In this article, we describe a partial left femur of a medium‐sized primate preserving its entire proximal portion and a significant length of its shaft. This fossil was recently recovered from the fossiliferous locality of Thamingyauk in the late middle Eocene Pondaung Formation (central Myanmar). This femur is considered to pertain to the same individual as two tarsal elements (fragmentary talus and calcaneus) from the same locality (same location), and attributed to a medium‐sized sivaladapid adapiform primate (Kyitchaungia takaii). This new postcranial element provides the first documentation of femoral anatomy among Sivaladapidae from Asia. The mechanical implications deriving from the musculoskeletal interpretation of this bone indicate an animal that probably engaged in a kind of active arboreal quadrupedalism with some degree of proficiency in leaping. Even though many musculoskeletal aspects suggest that branch walking and running were important parts of its locomotor repertoire, in other details it appears that relatively complex movements at the hip joint were actually possible and probably associated with climbing or some hindlimb suspensory activities. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Efficient and rapid synthesis of optically active polyamides in the presence of tetrabutylammonium bromide as ionic liquids under microwave irradiation
Authors: Mallakpour Shadpour , Taghavi Mehdi 
Published: June 2008

AbstractThere is increasing interest in using ionic liquids (ILs) as solvents for polymerization processes. The use of an inexpensive and readily available IL such as tetrabutylammonium bromide (TBAB) as a solvent for clean synthesis and catalytic processes is becoming widely recognized and accepted. This article reports an extension of a microwave method, describing the synthesis of optically active polyamides (PAs) in TBAB. Polycondensation reactions of diacid 5‐(3‐methyl‐2‐phthalimidylpentanoylamino) isophthalic acid with different diisocyanates such as 4, 4′‐methylenebis(phenyl isocyanate), toluylene‐2,4‐diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate were carried out in the presence of TBAB as a molten salt under microwave irradiation and with a conventional heating method, and they were compared with polymerizations in a traditional solvent such as 1‐methyl‐2‐pyrrolidone. A series of optically active PAs with high yields and inherent viscosities ranging from 0.20 to 0.60 dL/g were obtained. These PAs were characterized with Fourier transform infrared spectroscopy, specific rotation measurements, 1H‐NMR, elemental analysis, thermogravimetric analysis, and differential scanning calorimetry. All data agreed with the proposed structures. Some physical properties and structural characterizations of these PAs are reported. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and characterization of novel hyperbranched poly(amine‐ester) films crosslinked by glutaraldehyde
Authors: Wei Xiu‐Zhen , Zhu Li‐Ping , Zhu Bao‐Ku , Xu You‐Yi 
Published: June 2008

AbstractNovel films based on hydroxyl terminated hyperbranched poly (amine‐ester) (HPAE‐OH) of different generation were prepared by crosslinking the terminal hydroxyl groups of HPAE with glutaraldehyde (GA). The progress of crosslinking reaction was characterized by Fourier transform infrared (FTIR) and viscosity measurement. The surface morphology of the crosslinked HPAE films was characterized by field emission scanning electron microscope (FE‐SEM) and atomic force microscopy. The results suggested that the films have homogenously dense interior matrices and smooth surface. The hydrophilicity/hydrophobicity of the crosslinked HPAE films was characterized by the water contact angle measurement. Variable swelling behavior in different solvents was also studied. The in vitro biocompatibility of the film was investigated by the bovine hemoglobin (Hb) adsorption measurement. And these results showed that these crosslinked HPAE films had excellent hydrophilicity, variable swelling behavior in different solvents, and relative low protein absorption. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Inverse gas chromatography for the determination of the dispersive surface free energy and acid–base interactions of a sheet molding compound. I. Matrix material and glass
Authors: Mills Ryan H. , Tze William T. Y. , Gardner Douglas J. , van Heiningen Adriaan 
Published: June 2008

AbstractSheet molding compound is a material composed of a polyester thermosetting matrix with a thermoplastic, an inorganic filler, a metal oxide, reinforcement fibers, and material performance enhancers embedded in the crosslinked matrix. To achieve the optimum mechanical properties required for the composite material, the surface free energy of the polyester composite needs to be understood. In this study, the composite matrix and glass reinforcement fibers are compared with respect to their surface free energy and acid–base characteristics on the basis of inverse gas chromatography measurements. The inverse gas chromatography results for the matrix and glass are compared to previous results found for sized and unsized cellulosic fibers. The inverse gas chromatography data are used to assess chemical modifications performed on the biobased fibers to predict improvements in the fiber/matrix interaction, and this provides inferences on the overall composite cohesion. Our results show first that any fiber reinforcement system for the polyester composite material has to be acidic to promote good adhesion as the matrix system is very basic and second that the individual dispersive surface energies of the components of the matrix interact in a weighted average to determine the overall surface energy of the composite. Also, a commercial glass reinforcement sized for polyester has been found to have a lower interaction parameter than literature values for cellulosic fibers. This finding suggests that cellulosic fibers might have an advantage in competing with a conventional glass‐fiber reinforcement system in fiber/matrix bonding for sheet molding compound composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Characterization and microstructure study of low‐density polyethylene by Fourier transform infrared spectroscopy and temperature rising elution fractionation
Authors: Mahdavi Hossein , Nook Mojtaba Enayati 
Published: June 2008

AbstractInfrared spectroscopy is a powerful technique for studying the microstructure and determining the short‐chain branch distribution of polyethylene. In this work, the types and amounts of short‐chain branches in low‐density polyethylene were investigated with Fourier transform infrared spectroscopy, and a new and simple method for the determination of butyl short branches was discovered. The amount of each unsaturated species in low‐density polyethylene was also determined with Fourier transform infrared after the bromination of samples. Furthermore, the resin was fractionated by preparative temperature rising elution fractionation, and the branch distribution and melting endotherm of each fraction were analyzed with attenuated total reflectance/Fourier transform infrared and differential scanning calorimetry. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Levitation and movement of tripalmitin‐based cationic lipospheres on a dielectrophoresis‐based lab‐on‐a‐chip device
Authors: Fabbri Enrica , Borgatti Monica , Manaresi Nicolò , Medoro Gianni , Nastruzzi Claudio , Di Croce Silvia , Tosi Azzurra , Mazzitelli Stefania , Mancini Irene , Guerrieri Roberto , Gambari Roberto 
Published: June 2008

AbstractDielectrophoresis (DEP) is a very valuable approach for designing and developing laboratory‐on‐a‐chip (lab‐on‐a‐chip) devices that are able to manipulate microparticles and cells. Lab‐on‐a‐chip technology will enable laboratory testing to move from laboratories using complex equipment to nonlaboratory settings. We used a lab‐on‐a‐chip device, the SmartSlide, which carries 193 parallel electrodes and generates up to 50 cylinder‐shaped DEP cages able to entrap microparticles and cells within DEP cages and move them along the chip. For lab‐on‐a‐chip technology, the characterization of microparticles exhibiting a differential ability to be DEP‐caged, levitated, and moved is important for the development of both diagnostic and therapeutic protocols. We determined whether the SmartSlide could be used to levitate and move tripalmitin‐based lipospheres carrying increasing concentrations of dihexadecyl dimethyl ammonium bromide (DHDAB) as a cationic surfactant. The data obtained with this DEP‐based platform showed that DEP caging, levitation, and movement of the cationic lipospheres depended on the percentage of DHDAB. Tripalmitin lipospheres containing 6% DHDAB could be DEP‐caged and manipulated. On the contrary, lipospheres containing 12% DHDAB did not exhibit an efficient ability to be DEP‐caged and moved throughout the chip. To our knowledge, this is the first report on the possible use of a DEP‐based lab‐on‐a‐chip device for guided manipulation of lipospheres. This information might be of interest in the fields of drug discovery, delivery, and diagnosis. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dispersion and noncovalent modification of multiwalled carbon nanotubes by various polystyrene‐based polymers
Authors: Zhao Wei , Liu Yi‐Tao , Feng Qing‐Ping , Xie Xu‐Ming , Wang Xiao‐Hao , Ye Xiong‐Ying 
Published: June 2008

AbstractThis article investigated the dispersion and modification of multiwalled carbon nanotubes (MWCNTs) through solution mixing based on the noncovalent interactions between polystyrene (PS) and MWCNTs. It was found that the interactions were robust enough to stabilize the debundled MWCNTs in solution after vigorous sonication. The PS attached, which altered the surface properties of MWCNTs and made them easily soluble in organic solvents, can remain even after careful washing with solvents. Besides, many other PS‐based polymers were proved to retain the ability to disperse MWCNTs to form stable solutions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Architecture of rod consisting of hyperbranched pendant chains‐coil block copolymers by ATRP approach
Authors: Ishizu Koji , Takano Satoshi , Murakami Takuya , Uchida Satoshi , Ozawa Masaaki 
Published: June 2008

AbstractAtom transfer radical polymerization (ATRP) was applied to a novel synthesis of rod consisting of hyperbranched pendant chains‐coil block copolymers. The procedure included the following steps: (1) esterification reaction of poly(ethylene glycol) methyl ether (PEO) with 2‐bromoisobutyryl bromide (BIBB) yielded a PEO‐Br macroinitiator, (2) ATRP method of 2‐hydroxylethyl methacrylate (HEMA) using PEO‐Br provided PEO‐block‐poly(2‐hydroxyethyl methacrylate) (PHEMA) block copolymers, (3) esterification of PEO‐block‐PHEMA with BIBB yielded block‐type polyinitiator, and (4) ATRP of HEMA‐Br inimer using block‐type polyinitiator provided coil‐rod (consisting of hyperbranched pendant chains) block copolymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Dynamische Simulation des sommerlichen Temperaturverhaltens eines Büroraumes mit einer modifizierten CFD‐Technik
Authors: Pfrommer Peter , Zitzmann Tobias 
Published: June 2008

AbstractDie im Rahmen des Forschungsprojektes “THERMEX Coburg” entwickelte adaptive Freeze‐Flow‐Technik FREEZECONT ermöglicht dynamische Langzeitsimulationen mit dem CFD‐Programm ANSYS CFX. Die neue Rechentechnik wird zunächst anhand von sechstägigen Simulationen des sommerlichen Temperaturverhaltens eines gängigen Büroraumes mit Nachtlüftungsstrategie mit und ohne Bauteilaktivierung demonstriert. Eine weitere Studie befasst sich mit dem Vergleich zwischen dynamischen CFD‐Berechnungen (mit FREEZECONT) und denjenigen zonaler Gebäudesimulationsprogramme am Beispiel TRNSYS. Schließlich erlaubt CFX/FREEZECONT erste praxisrelevante Aussagen über den Einfluss von abgehängten Akustikbaffeln auf das dynamisch thermische Verhalten eines Büroraumes.
Temperaturentwicklung und Beanspruchung von Tunnelschalen im Brandfall
Authors: Hörrle Dominik , Mayer Peter‐Michael 
Published: June 2008

AbstractBrand ist im Tunnelbau einer der maßgebenden Lastfälle. Nachweisverfahren und Rechenmodelle sind derzeit noch in der Entwicklung. In diesem Aufsatz soll auf analytische Weise gezeigt werden, zu welchen Temperaturen es beim Brand an der Innenseite der Tunnelschale kommen kann und wie diese abschätzbar sind. Erlangt man so Kenntnis über eine zutreffende Temperaturzeitkurve, kann, unter bestimmten Randbedingungen, die instationäre Wärmeleitungsgleichung gelöst werden. Dadurch ist der Temperaturverlauf im Querschnitt zu jeder Zeit in jeder Tiefe analytisch gegeben und wird für einige Beispiele berechnet. Die Ergebnisse werden mit Messergebnissen realer Brandversuche verglichen und die Gültigkeit der dem analytischen Lösungsweg geschuldeten Vereinfachungen verifiziert. Anschließend wird das Lösungsmodell verwendet, um zeitabhängige Dehnungen und Krümmungen in Beispielquerschnitten (Schichtenmodell aus [1]) zu ermitteln und dort den Einfluss etwa der Temperaturleitfähigkeit aufzuzeigen.
Correlation between symmetry breaker position and the preferences of conformationally constrained homopeptides: A molecular dynamics investigation
Authors: Torras Juan , Zanuy David , Crisma Marco , Toniolo Claudio , Betran Oscar , Alemán Carlos 
Published: June 2008

AbstractThe conformational tendencies of Cα,α‐diethylglycine (Deg)‐based peptides have been studied in solution using all atom molecular dynamics simulations. Specifically, the conformational effects of breaking the symmetry of the host Tfa‐(Deg)5‐OtBu (Tfa, trifluoroacetyl; OtBu, tert‐butoxy) pentapeptide with punctual replacements at different sequence positions of one Deg residue by its corresponding guest chiral analogue, L‐α‐aminobutyric acid (L‐Abu), have been examined by simulating the following peptides: Tfa‐(Deg)5‐OtBu, Tfa‐(Deg)2‐L‐Abu‐(Deg)2‐OtBu, Tfa‐(Deg)3‐L‐Abu‐Deg‐OtBu, and Tfa‐(Deg)4‐L‐Abu‐OtBu. Simulations show that only the Deg homopeptide is able to stabilize a 2.05 helix, even though a kinked arrangement with all the Deg residues adopting a fully‐extended conformation was found to be stable when the L‐Abu residue is introduced in the middle of the sequence. On the other hand, when the L‐Abu residue is closer to the C‐end of the sequence, the peptide chain prefers a partially folded 310‐helix. Additional simulations on Tfa‐(Deg)3‐L‐Abu‐(Deg)3‐OtBu highlighted that, when the size of the Deg segments increases, their tendency to adopt a 2.05 helix predominates over the preferred folded conformation of L‐Abu. The overall picture extracted after more than 300 ns of molecular dynamics simulation is that breaking the α‐carbon symmetry of achiral Cα‐tetrasubstituted amino acids is a promising strategy to build up polypeptides with modulated conformational tendencies. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 695–706, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Rapid cloning and purification of proteins: Gateway vectors for protein purification by self‐cleaving tags
Authors: Gillies Alison R. , Hsii Judy F. , Oak Seachol , Wood David W. 
Published: June 2008

AbstractWe have combined Invitrogen's Gateway® cloning technology with self‐cleaving purification tags to generate a new system for rapid production of recombinant protein products. To accomplish this, we engineered our previously reported ΔI‐CM cleaving intein to include a Gateway cloning recognition sequence, and demonstrated that the resulting Gateway‐competent intein is unaffected. This intein can therefore be used in several previously reported purification methods, while at the same time being compatible with Gateway cloning. We have incorporated this intein into a set of Gateway vectors, which include self‐cleaving elastin‐like polypeptide (ELP), chitin binding domain (CBD), phasin (polyhydroxybutyrate‐binding), or maltose binding domain (MBD) tags. These vectors were verified by Gateway cloning of TEM‐1 β‐lactamase and Escherichia coli catalase genes, and the expressed target proteins were purified using the four methods encoded on the vectors. The purification methods were unaffected by replacing the ΔI‐CM intein with the Gateway intein. It was observed that some purification methods were more appropriate for each target than others, suggesting utility of this technology for rapid process identification and optimization. The modular design of the Gateway system and intein purification method suggests that any tag and promoter can be trivially added to this system for the development of additional expression vectors. This technology could greatly facilitate process optimization, allowing several targets and methods to be tested in a high‐throughput manner. Biotechnol. Bioeng. 2008;101: 229–240. © 2008 Wiley Periodicals, Inc.
Phenomenological model of fungal biofilters for the abatement of hydrophobic VOCs
Authors: Vergara‐Fernández Alberto , Hernández Sergio , Revah Sergio 
Published: June 2008

AbstractThis work describes the growth of filamentous fungi in biofilters for the degradation of hydrophobic VOCs. The study system was n‐hexane and Fusarium solani B1. The system is mathematically described and the main physical, kinetic data and morphological parameters were obtained by independent experiments and validated with data from laboratory experiments. The model describes the increase in the transport area by the growth of the filamentous cylindrical mycelia and its relation with n‐hexane elimination in quasi‐stationary state in a biofilter. The model describing fungal growth includes Monod–Haldane kinetic and hyphal elongation and ramification. A specific surface area of transport (SSAT) of 1.91 × 105 m2 m−3 and a maximum elimination capacity (EC) of 248 g m−3 h−1 were obtained by the mathematical model simulation, with a 10% of error with respect to the experimental EC. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc.
Immobilization of cellulose fibrils on solid substrates for cellulase‐binding studies through quantitative fluorescence microscopy
Authors: Moran‐Mirabal Jose M. , Santhanam Navaneetha , Corgie Stephane C. , Craighead Harold G. , Walker Larry P. 
Published: June 2008

AbstractCellulases, enzymes capable of depolymerizing cellulose polymers into fermentable sugars, are essential components in the production of bioethanol from lignocellulosic materials. Given the importance of these enzymes to the evolving biofuel industry considerable research effort is focused on understanding the interaction between cellulases and cellulose fibrils. This manuscript presents a method that addresses challenges that must be overcome in order to study such interactions through high‐resolution fluorescence microscopy. First, it is shown that cellulose can be immobilized on solid substrates through a polymer lift‐off technique. The immobilized cellulose aggregates present characteristic morphologies influenced by the patterned feature size used to immobilize it. Thus, through a variety of pattern sizes, cellulose can be immobilized in the form of cellulose particles, cellulose mats or individual cellulose fibrils. Second, it is shown that both cellulose and Thermobifida fusca cellulases Cel5A, Cel6B, and Cel9A can be fluorescently tagged and that the labeling does not inhibit the capability of these cellulases to depolymerize cellulose. The combination of the immobilization technique together with fluorescence labeling yields a system that can be used to study cellulose–cellulase interactions with spatial and temporal resolution not available through more conventional techniques which measure ensemble averages. It is shown that with such a system, the kinetics of cellulase binding onto cellulose fibrils and mats can be followed through sequences of fluorescence images. The intensity from the images can then be used to reconstruct binding curves for the cellulases studied. It was found that the complexity of cellulose morphology has a large impact on the binding curve characteristics, with binding curves for individual cellulose fibrils closely following a binding saturation model and binding curves for cellulose mats and particles deviating from it. The behavior observed is interpreted as the effect pore and interstice penetration play in cellulase binding to the accessible surface of cellulose aggregates. These results validate our method for immobilizing nanoscale cellulose fibrils and fibril aggregates on solid supports and lay the foundation for future studies on cellulase–cellulose interactions. Biotechnol. Bioeng. © 2008 Wiley Periodicals, Inc.