bluuebunny/crossref_metadata_2025_split huggingface dataset:
Streptococcus ictaluri Arthritis, Osteolysis, Myositis, and Spinal Meningitis in Channel Catfish Broodstock
Authors: Camus Alvin C. , Shewmaker P. Lynn , Mauel Michael J. , Wise David J. 
Published: March 2008

Abstract
This report details findings of an investigation into complaints by commercial fingerling producers of low-grade mortalities, poor reproductive success, emaciation, skin lesions, and severely arched backs among broodstock of channel catfish Ictalurus punctatus. Gross lesions involved the jaw, fin bases, and vertebral column. Jaw and fin lesions consisted of small hemorrhagic ulcers and exudate-filled tracts that communicated with underlying joints and destroyed their articular surfaces. Spinal changes, recognized grossly by severe arching of the proximal vertebral column, resulted from the collapse and displacement of vertebral bodies, causing compression of the spinal cord. Affected vertebrae were lysed by pyogranulomatous inflammation that infiltrated into adjacent muscle and the spinal canal. A Streptococcus-like organism was visualized in exudate and isolated repeatedly from lesions, but only once from the kidney of a single fish. Preliminary analysis of a 16S ribosomal DNA sequence showed a close relationship to S. iniae, S. parauberis, and S. canis. Koch's postulates were fulfilled after challenge with and reisolation of the agent from identical lesions that appeared at fin bases at 2 weeks postinjection. Historical evidence and gross and microscopic findings imply the presence of a pathogen of low virulence that is capable of producing severe localized infections after a brief period of septicemia. The disease presents as a chronic debilitating syndrome that is sufficient to inhibit mobility, feeding, and reproductive activity in affected fish. Complete biochemical and molecular characterization of the bacterium (published elsewhere) has established the agent as a novel species, S. ictaluri.
Are the lights coming on? How can we tell? English language learners and literacy assessment
Authors: Toohey Kelleen 
Published: March 2008

Abstract: This article explores definitions of reading comprehension, research on how reading comprehension is assessed, and issues in assessing the reading comprehension of English language learners (ELLs). By way of illustration, I present aspects of the literacy practices of an intermediate-grade ELL in a suburban school of the Lower Mainland of British Columbia. This learner, Aman, is evaluated as being ‘not yet within expectations’ on a reading-comprehension test given by the BC Ministry of Education. The article examines Aman's writing, showing that she has appropriated some important aspects of written language, and argues that her writing and reading comprehension must be supported so that she can achieve as fully as possible the benefits of her education. This case is representative of many ELLs’ trajectories in English literacy learning in BC schools and illustrates some of the human faces behind ELL achievement patterns.
Air‐Stable and Highly Active Dendritic Phosphine Oxide‐ Stabilized Palladium Nanoparticles: Preparation, Characterization and Applications in the Carbon‐Carbon Bond Formation and Hydrogenation Reactions
Authors: Wu Lei , Li Zhi‐Wei , Zhang Feng , He Yan‐Mei , Fan Qing‐Hua 
Published: March 2008

AbstractDendrimer‐stabilized palladium nanoparticles were formed in the reduction of palldium bis(acetylacetonate) [Pd(acac)2] in the presence of phosphine dendrimer ligands using hydrogen in tetrahydrofuran. The resulting Pd nanoparticles were characterized by TEM, 31P NMR and 31P MAS NMR. The results indicated that the dendritic phosphine ligands were oxidized to phosphine oxides. These dendrimer‐stabilized Pd nanoparticles were demonstrated to be efficient catalysts for Suzuki and Stille coupling reactions and hydrogenations. The dendritic wedges served as a stabilizer for keeping the nanoparticles from aggregating, and as a vehicle for facilitating the separation and/or the recycling of the Pd catalyst. In the case of the Suzuki coupling reaction, these Pd nanoparticles exhibited high catalytic efficiency (TON up to 65,000) and air stability as compared with the commonly used homogeneous catalyst tetrakis(triphenylphosphine)palladium [Pd(PPh3)4]. In addition, the results obtained from the bulky dendritic substrate suggest that the Pd nanoparticles might act as reservoir of catalytically active species, and that the reaction is actually catalyzed by the soluble Pd(0) and/or Pd(II) species leached from the nanoparticle surface.
Extensive Re‐Investigations of Pressure Effects in Rhodium‐ Catalyzed Asymmetric Hydrogenations
Authors: Alame Mohamad , Pestre Nathalie , de Bellefon Claude 
Published: March 2008

AbstractThe catalytic hydrogenation of three pro‐chiral substrates methyl Z‐α‐acetamidocinnamate (MAC), methyl 2‐acetamidoacrylate (M‐Acrylate) and ethyl 4‐methyl‐3‐acetamido‐2‐propanoate (E‐EMAP) with rhodium precursors complexed with chiral diphosphines is reported at 1–30 bar hydrogen pressure. A library of 56 chiral diphosphines, including 23 BINAP derivatives, 7 JOSIPHOS, 5 BIPHEP, 3 DUPHOS derivatives, and 18 other ligands, was used. While it was generally accepted that high hydrogen pressure would result in lower ees, it is now demonstrated on a statistical basis that an equivalent distribution between beneficial and detrimental pressure effects on ee prevails and that the hydrogen pressure effect on enantioslectivity is not an isolated phenomenon since more than 33% of the reaction systems studied are strongly affected. In some case, the enantioselectivity can be improved up to 97% just by applying a higher hydrogen pressure. Extension of these conclusions to other non‐chiral reagents is proposed.
Development of a Model System for the Study of Long Distance Electron Transfer in Peptides
Authors: Cordes Meike , Jacques Olivier , Köttgen Agnieszka , Jasper Christian , Boudebous Hassen , Giese Bernd 
Published: March 2008

AbstractWe have designed and synthesized a peptide model in which stepwise electron transfer (ET) through amino acid side chains could be observed. An injection system, which generates an electron hole upon laser irradiation, was connected directly to the aromatic side chain of a modified C‐terminal amino acid. This electron acceptor could be observed by transient absorption spectroscopy. The N‐terminal amino acid tyrosine acts as an electron donor, giving a different signal in the transient absorption spectrum. Additional non‐natural oxidizable aromatic amino acids were synthesized as spectroscopic sensors to detect oxidized amino acid side chains as chemical intermediates in long range ET.
Leaching and fastness behavior of cotton fabrics dyed with different type of dyes using sol‐gel process
Authors: Aķ⋅it Aysun Cireli , Onar Nurhan 
Published: March 2008

AbstractCotton fabrics were dyed with reactive, direct, and basic dyes by sol‐gel process and exhausting process. As to this aim, the solutions of reactive, direct, and basic dyes were prepared by sol‐gel process and then cotton fabrics were treated at 80°C for 10 min with these solutions and dried at 120°C for 20 min. Dyeing solutions contained tetraethyl orthosilicate and 3‐glycidoxypropyl‐trimethoxysilane as precursor, ethanol and water as solvent for sol‐gel process. The wash fastness, light fastness, rubbing fastness and the degree of leaching, the light fading value, and dyeing yield of dyeings were evaluated. Moreover, the effect on dyeing yield, fastnesses, leaching, and fading properties of adding of sodium acetate trihydrate in dyeing solutions for sol‐gel process was firstly studied. It was found that the dyeing yield of dyed cotton fabrics with the direct dyes significantly improved with using sol‐gel process with adding sodium acetate trihydrate in comparison with exhausting process. The color fastness values to washing and to light of the basic dyeing increased with using sol‐gel process without adding sodium acetate trihydrate in comparison with exhausting process. The degree of leaching of dyed fabrics with the basic and reactive dyes decreased with using sol‐gel process with adding sodium acetate trihydrate in comparison with exhausting process. The light fading value of dyed cotton fabrics with the basic and direct dyes after 120 h irridation decreased with using sol‐gel process with adding sodium acetate trihydrate in comparison with exhausting process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The structure and dynamic properties of nitrile–butadiene rubber/poly(vinyl chloride)/hindered phenol crosslinked composites
Authors: Xiang Ping , Zhao Xiu‐Ying , Xiao Da‐Ling , Lu Yong‐Lai , Zhang Li‐Qun 
Published: March 2008

AbstractIn this article, a new nitrile–butadiene rubber (NBR) crosslinked composites containing poly(viny chloride) (PVC) and hindered phenol (AO‐80 and AO‐60) was successfully prepared by melt‐blending procedure. Microstruture and dynamic mechanical properties of the composites were investigated using SEM, DSC, XRD, and DMTA. Most of hindered phenol was dissolved in the NBR/PVC matrix and formed a much fine dispersion. The results of DSC and DMTA showed that strong intermolecular interaction was formed between the hindered phenol and NBR/PVC matrix. The NBR/PVC/AO‐80 crosslinked composites showed only one transition with higher glass transition temperature and higher tan δ value than the neat matrix, whereas for the NBR/PVC/AO‐60 crosslinked composites, a new transition appeared above the glass transition temperature of matrix, which was associated with the intermolecular interaction between AO‐60 and PVC component of the matrix. Both AO‐80 and AO‐60 in the crosslinked composites existed in amorphous form. Furthermore, the chemical crosslinking of composites resulted in better properties of the materials, e.g., considerable tensile strength and applied elastic reversion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Improving the mechanical properties of polypropylene via melt vibration
Authors: Li Youbing , Shen Kaizhi 
Published: March 2008

AbstractThe effect of melt vibration on the mechanical properties of polypropylene prepared by low‐frequency vibration‐assisted injection molding (VAIM) has been investigated. With the application of melt vibration technology, the mechanical properties of polypropylene are improved. The yield strength increases with the increment of the vibration frequency, and a peak stands at a special frequency for VAIM; the elongation at break decreases first and then increases with increasing vibration frequency, and a valley stands at a special frequency. The tensile properties increase sharply at an enlarged vibration pressure amplitude with sharply decreased elongation at break. The Young's modulus and impact strength also increase with the vibration frequency and pressure vibration amplitude. When it is prepared at 59.4 MPa and 0.7 Hz, the maximal yield strength is approximately 40 MPa versus 33.7 MPa for a conventional sample; an 18.7% increase in the tensile strength is produced. Self‐reinforcing and self‐toughening polypropylene molded parts have been found to be prepared at a high vibration frequency or at a large pressure vibration amplitude. Scanning electron micrographs have shown that, in the vibration field, the enhancement of the mechanical properties is attributable to more pronounced spherulite orientation and increased crystallinity in comparison with conventional injection moldings. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, characterization, and redox and electrochromic behaviors of poly(3‐n‐octyloxythiophene)
Authors: Sheng Chen , Wenting Bao , Shijian Tu , Yuechuan Wang 
Published: March 2008

AbstractPoly(3‐n‐octyloxythiophene), a conjugated polymer, which possessed solubility in common organic solvents, was synthesized by electrochemical polymerization in the presence of lithium perchlorate as the supporting electrolyte and sodium dodecyl sulfate as the surfactant in an aqueous medium. Characterizations of the intermediate, monomer, and polymer were performed by NMR spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, and gel permeation chromatography. The process of electrochemical polymerization and the electrochemical redox behaviors were investigated by cyclic voltammetry and the potentiostatic method. A poly(3‐n‐octyloxythiophene) film that was deposited on a platinum electrode was found to exhibit electrochromic behaviors, and it switched electrochemically between blue–green oxidized and dark red reduced states. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Flammability of blends of low‐density polyethylene and ethylene vinyl acetate crosslinked by both dicumyl peroxide and ionizing radiation for wire and cable applications
Authors: Shukri T. M. , Mosnáček J. , Basfar A. A. , Bahattab M. A. , Noireaux P. , Courdreuse A. 
Published: March 2008

AbstractFormulations of chemically crosslinked and radiation‐crosslinked low‐density polyethylene (LDPE) containing an intumescent flame retardant such as ammonium polyphosphate were prepared. The influence of blending LDPE with poly(ethylene vinyl acetate) (EVA) as well as the effects of a coadditive such as talc on flammability was investigated. Chemical crosslinking by dicumyl peroxide and crosslinking by ionizing radiation from an electron‐beam accelerator were both used and compared. An increase in the limiting oxygen index (LOI) was found by the partial replacement of LDPE with EVA. The effect of talc on the flammability depended on the amount of talc in the formulations. The addition of a small amount of talc increased LOI and reduced smoke during cone calorimeter measurements. A higher amount of talc led to a decrease in the LOI values. Formulations crosslinked by ionizing radiation yielded lower LOI values than chemically crosslinked formulations. This could be attributed to the use of trimethylolpropane triacrylate as a crosslinking coagent in formulations crosslinked by ionizing radiation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
[8+2] and [8+3] Cyclization Reactions of Alkenyl Carbenes and 8‐Azaheptafulvenes: Direct Access to Tetrahydro‐1‐azaazulene and Cyclohepta[b]pyridinone Derivatives
Authors: Barluenga José , García‐Rodríguez Jaime , Martínez Silvia , Suárez‐Sobrino Ángel L. , Tomás Miguel 
Published: March 2008

AbstractThe reactivity of Fischer alkenyl carbenes toward 8‐azaheptafulvenes is examined. Alkenyl carbenes react with 8‐azaheptafulvenes with complete regio‐ and stereoselectivity through formal [8+3] and [8+2] heterocyclization reactions, which show an unprecedented dependence on the Cβ substituent at the alkenyl carbene complex. Thus, the formal [8+3] heterocyclization reaction is completely favored in carbene complexes that bear a coordinating moiety to give tetrahydrocyclohepta[b]pyridin‐2‐ones. Otherwise, alkenyl carbenes that lack appropriate coordinating groups undergo a formal [8+2] cyclization with 8‐azaheptafulvenes to give compounds that bear a tetrahydroazaazulene structure. A likely mechanism for these reactions would follow well‐established models and would involve a 1,4‐addition/cyclization in the case of the [8+2] cyclization or a 1,2‐addition/[1,2] shift–metal‐promoted cyclization for the [8+3] reaction. The presence of a coordinating moiety in the carbene would favor the [1,2] metal shift through transition‐state stabilization to lead to the [8+3] product. All these processes provide an entry into the tetrahydroazaazulene and cycloheptapyridone frameworks present in the structure of biologically active molecules.
Intramolecular Diamination of Alkenes with Palladium(II)/Copper(II) Bromide and IPy2BF4: The Role of Halogenated Intermediates
Authors: Muñiz Kilian , Hövelmann Claas H. , Campos‐Gómez Esther , Barluenga José , González José M. , Streuff Jan , Nieger Martin 
Published: March 2008

AbstractThe oxidative intramolecular diamination of alkenes with tethered ureas and related groups as the nitrogen source has been investigated both with the iodonium reagent IPy2BF4 (Py=pyridine) and under palladium catalysis in the presence of copper(II) bromide as a reoxidant. For terminal alkenes, the two procedures enable selective and high‐yielding transformations. Studies with deuterated material led to the conclusion that the reactions proceed through different stereochemical pathways. An advanced protocol for palladium‐catalyzed diamination through six‐membered‐ring annulation was also developed, and the first examples of the intramolecular diamination of internal alkenes are described. In this case, the same stereochemical outcome was observed for the iodonium‐promoted and palladium‐catalyzed transformations. On this basis, it was possible to determine the importance of aminohalogenated intermediates in both diamination reactions. Overall, the disclosed procedures broaden significantly the synthetic applicability of the oxidative intramolecular diamination of alkenes.
High‐throughput screening of chromatographic separations: I. Method development and column modeling
Authors: Coffman Jonathan L. , Kramarczyk Jack F. , Kelley Brian D. 
Published: March 2008

AbstractThe development of purification processes for protein biopharmaceuticals is challenging due to compressed development timelines, long experimental times, and the need to survey a large parameter space. Typical methods for development of a chromatography step evaluate several dozen chromatographic column runs to optimize the conditions. An efficient batch‐binding method of screening chromatographic purification conditions in a 96‐well format with a robotic liquid‐handling system is described and evaluated. The system dispenses slurries of chromatographic resins into filter plates, which are then equilibrated, loaded with protein, washed and eluted. This paper evaluates factors influencing the performance of this high‐throughput screening technique, including the reproducibility of the aliquotted resin volume, the contact time of the solution and resin during mixing, and the volume of liquid carried over in the resin bed after centrifugal evacuation. These factors led to the optimization of a batch‐binding technique utilizing either 50 or 100 µL of resin in each well, the selection of an industrially relevant incubation time of 20 min, and the quantitation of the hold‐up volume, which was as much as one quarter of the total volume added to each well. The results from the batch‐binding method compared favorably to chromatographic column separation steps for a cGMP protein purification process utilizing both hydrophobic interaction and anion‐exchange steps. These high‐throughput screening tools can be combined with additional studies on the kinetics and thermodynamics of protein–resin interactions to provide fundamental information which is useful for defining and optimizing chromatographic separations steps. Biotechnol. Bioeng. 2008;100: 605–618. © 2008 Wiley Periodicals, Inc.
High‐throughput screening of chromatographic separations: II. Hydrophobic interaction
Authors: Kramarczyk Jack F. , Kelley Brian D. , Coffman Jonathan L. 
Published: March 2008

AbstractA high‐throughput screen (HTS) was developed to evaluate the selectivity of various hydrophobic interaction chromatography (HIC) resins for separating a mAb from aggregate species. Prior to the resin screen, the solubility of the protein was assessed to determine the allowable HIC operating region by examining 384 combinations of pH, salt, and protein concentration. The resin screen then incorporated 480 batch‐binding and elution conditions with eight HIC resins in combination with six salts. The results from the screen were reproducible, and demonstrated quantitative recovery of the mAb and aggregate. The translation of the HTS batch‐binding data to lab‐scale chromatography columns was tested for four conditions spanning the range of product binding and selectivity. After accounting for the higher number of theoretical plates in the columns, the purity and recovery of the lab‐scale column runs agreed with the HTS results demonstrating the predictive power of the filterplate system. The HTS data were further analyzed by the calculation of pertinent thermodynamic parameters such as the partition coefficient, KP, and the separation factor, α. The separation factor was used to rank the purification capabilities of the resin and salt conditions explored. Biotechnol. Bioeng. 2008;100: 707–720. © 2008 Wiley Periodicals, Inc.
Implementation and assessment of a molecular biology and bioinformatics undergraduate degree program
Authors: Pham Daphne Q.‐D. , Higgs David C. , Statham Anne , Schleiter Mary Kay 
Published: March 2008

AbstractThe Department of Biological Sciences at the University of Wisconsin‐Parkside has developed and implemented an innovative, multidisciplinary undergraduate curriculum in Molecular Biology and Bioinformatics (MBB). The objective of the MBB program is to give students a hands‐on facility with molecular biology theories and laboratory techniques, an understanding of mathematical and physical concepts, an ability to apply these concepts to MBB, and a proficiency with the computational tools and skills related to bioinformatics. We hypothesized that a greater exposure to bioinformatics methods, more rigorous requirements in math and computer science, and a constant demand for integrating information in hands‐on laboratory courses would help students develop better analytical skills. Indeed, the assessment data support these predictions. Interestingly, 80% of MBB majors apply and are accepted into graduate schools.
Biochemical thermodynamics under near physiological conditions
Authors: Méndez Eduardo 
Published: March 2008

AbstractThe recommendations for nomenclature and tables in Biochemical Thermodynamics approved by IUBMB and IUPAC in 1994 can be easily introduced after the chemical thermodynamic formalism. Substitution of the usual standard thermodynamic properties by the transformed ones in the thermodynamic equations, and the use of appropriate thermodynamic tables can be easily employed in the study of the energetics of biochemical equations, regulatory systems, and metabolic pathways under near physiological conditions.
Use of molecular dynamics data in biochemistry courses
Authors: Mazzé Fernanda M. , Fuzo Carlos A. , Degrève Léo , Ciancaglini Pietro 
Published: March 2008

AbstractThe aim of this manuscript is to explain the application of an amphipathy scale obtained from molecular dynamics simulations and to demonstrate how it can be useful in the protein structure field. It is shown that this scale is easy to be used with the advantage of revealing domains of transmembrane α‐helix of proteins without the need of knowing anything besides the protein primary structure. In addition, it allows the students to correlate concepts of protein structure and function, energy minimization, molecular dynamics simulations, and protein location.
A laboratory exercise to determine human ABO blood type by noninvasive methods
Authors: Martin Michael P. , Detzel Stephen M. 
Published: March 2008

AbstractAnalysis of single‐nucleotide polymorphisms and their association with diseases and nondisease phenotypes is of growing importance in human biology studies. In this laboratory exercise, students determine the genetic basis for their ABO blood type; however, no blood is drawn. Students isolate genomic DNA from buccal mucosa cells that are present in saliva and analyze the DNA on an agarose gel. Subsequently, this DNA is used as a PCR template to amplify exons 6 and 7 of the gene that determines the human ABO phenotype. These PCR products are digested and run on agarose gels to examine the restriction fragment length polymorphisms. A deletion in the O1 allele converts the BstE II site in exon 6 into a Kpn I site, and this feature is used to determine the presence of O1 alleles. The pattern of exon 7 digest products allows students to distinguish among four other common ABO alleles: A1, A2, B, and O2. This exercise introduces students to commonly used molecular biology techniques, such as genomic DNA isolation, PCR, gel electrophoresis, and restriction digests.