bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linkages between White Sturgeon Recruitment and Altered Bed Substrates in the Nechako River, Canada
Authors: McAdam Steven O. , Walters Carl J. , Nistor Craig 
Published: October 2005

AbstractReconstructed recruitment was compared with the relatively limited set of anthropogenic alterations to the Nechako watercourse to identify and investigate potential causes of recruitment failure of Nechako River white sturgeon Acipenser transmontanus. Back‐calculation of historic recruitment shows that recruitment was present but variable from 1946 until 1964. Subsequent to 1964 there was a rapid decline, principally in 1967, and recruitment failure has continued since that time. Flow regulation, which began in 1952 with the completion of Kenney Dam, preceded recruitment failure by 15 years and therefore flow regulation does not supply a simple unicausal explanation for recruitment failure.We propose that sediment input from an upstream channel avulsion in 1961, in combination with elevated flows in 1964 and 1967, led to alterations to riverbed substrates in critical white sturgeon habitat. Using air photos and specific gauge analysis, we identified a “sediment wave” in the upper Nechako River. The timing and location of avulsion sediments indicates that recruitment failure is most likely due to alteration of main channel substrates rather than the loss of off‐channel habitat. Findings are discussed with reference to general hypotheses for recruitment failure in other white sturgeon populations.
Activation of Canonical Wnt Pathway Promotes Proliferation of Retinal Stem Cells Derived from Adult Mouse Ciliary Margin
Authors: Inoue Toshihiro , Kagawa Tetsushi , Fukushima Mikiko , Shimizu Takeshi , Yoshinaga Yutaka , Takada Shinji , Tanihara Hidenobu , Taga Tetsuya 
Published: October 2005

Abstract
Adult retinal stem cells represent a possible cell source for the treatment of retinal degeneration. However, only a small number of stem cells reside in the ciliary margin. The present study aimed to promote the proliferation of adult retinal stem cells via the Wnt signaling pathway. Ciliary margin cells from 8-week-old mice were dissociated and cultured to allow sphere colony formation. Wnt3a, a glycogen synthase kinase (GSK) 3 inhibitor, fibroblast growth factor (FGF) 2, and a FGF receptor inhibitor were then applied in the culture media. The primary spheres were dissociated to prepare either monolayer or secondary sphere cultures. Wnt3a increased the size of the primary spheres and the number of Ki-67–positive proliferating cells in monolayer culture. The Wnt3a-treated primary sphere cells were capable of self-renewal and gave rise to fourfold the number of secondary spheres compared with nontreated sphere cells. These cells also retained their multilineage potential to express several retinal markers under differentiating culture conditions. The Wnt3a-treated cells showed nuclear accumulation of β-catenin, and a GSK3 inhibitor, SB216763, mimicked the mitogenic activity of Wnt3a. The proliferative effect of SB216763 was attenuated by an FGF receptor inhibitor but was enhanced by FGF2, with Ki-67–positive cells reaching over 70% of the total cells. Wnt3a and SB216763 promoted the proliferation of retinal stem cells, and this was partly dependent on FGF2 signaling. A combination of Wnt and FGF signaling may provide a therapeutic strategy for in vitro expansion or in vivo activation of adult retinal stem cells.
Preparation of (Triphenylphosphoranylidene)‐Ketene from (Methoxycarbonylmethylene)‐Triphenylphosphorane
Authors: Schobert Rainer 
Published: October 2005

Abstract

(Triphenylphosphoranylidene)ketene

(Methoxycarbonylmethylene)triphenylphosphorane

Hexamethyldisilazane

Sodium amide
Catalytic Asymmetric Acyl Halide‐Aldehyde Cyclocondensation Reaction
Authors: Nelson Scott G. , Mills Paul M. 
Published: October 2005

Abstract

(
S
)‐Valinol

Triethylamine

Trifluoromethanesulfonic anhydride

(
S
)‐
N
‐Trifluoromethylsulfonyl‐2‐isopropylaziridine

Benzylamine

(2
S
,6
S
)‐4‐Benzyl‐1,7‐bis(trifluoromethylsulfonyl)‐2,6‐disopropyll‐1,4,7‐triazaheptane

Disiopropylethylamine

Trimethylaluminum

Acetyl bromide

Hydrocinnamaldehyde

(4
S
)‐4‐(2‐Phenethyl)oxetane‐2‐one
Alkyne

via

Solid‐Liquid Phase‐Transfer Catalyzed Dehydrohalogenation: Acetylene Dicarboxaldehyde Tetramethyl Acetal and Acetylene Dicarboxaldehyde Dimethyl Acetal
Authors: Akué‐Gédu Rufine , Rigo Benoît 
Published: October 2005

Abstract

2,5‐Dimethoxy‐2,5‐dihydrofuran

Bromine

Dibromo‐2,5‐dimethoxytetrahydrofuran

Methanol

2,3‐Dibromo‐1,1,4,4,‐tetramethoxybutane

Tris[2‐(2‐methoxyethoxy)‐ethyl]amine

Potassium hydroxide

1,1,4,4‐Tetramethoxybut‐2‐yne formic acid

4,4‐Dimethoxybut‐2‐ynal
Catalytic Reduction of Amides to Amines with Hydrosilanes Using a Triruthenium Carbonyl Cluster as the Catalyst
Authors: Motoyama Yukihiro , Itonaga Chikara , Ishida Toshiki , Takasaki Mikihiro , Nagashima Hideo 
Published: October 2005

Abstract

Acenaphthylene

Ruthenium, dodecacarbonyltri‐, triangulo

Phenyldimethylsilane

N
,
N
‐Dimethyl‐3‐phenylpropionamide

N
,
N
‐Dimethyl‐3‐phenylproplyamine
Nomenclature of Polymers
Authors: Schultz J. L. , Wilks E. S. 
Published: October 2005

AbstractPolymer nomenclature is the naming of polymeric materials. The two principal approaches to nomenclature relate to the two methods used for graphical representation of polymers — source based and structure based. Ideally, a structure‐based name should accompany a structure‐based representation of a polymer, while a source‐based name should accompany a source‐based representation. In practice, deviations from this ideal occur frequently; the scientific community prefers representations accompanied by source‐based names because they latter are easier to generate and use. This article explains the principles of both structure‐based and source‐based nomenclatures, and gives examples for regular linear single‐strand organic, double‐strand (ladder and spiro) organic, irregular single‐strand organic, inorganic, and coordination, and alternating, block, graft, periodic, and modified polymers. Stereochemistry in polymers is also covered. Nomenclature styles recommended by the International Union of Pure and Applied Chemistry and used by Chemical Abstracts Service are discussed. A list of abbreviations and acronyms for many common polymers is included.
Ultrasound‐Induced Radical Polymerization
Authors: Kuijpers Martijn W. A. , Kemmere Maartje F. , Keurentjes Jos T. F. 
Published: October 2005

AbstractSonochemistry comprises all chemical effects that are induced by ultrasound. Most of these effects are caused by cavitations, ie, the collapse of microscopic bubbles in a liquid. The chemical effects of ultrasound include the formation of radicals and the enhancement of reaction rates at ambient temperatures. For the development of sustainable polymer processes, ultrasound is an interesting technology, as it allows for polymerizations without the use of initiator. The radicals are generatedin situby cavitation events, which enable a clean and intrinsically safe polymerization reaction. As a result of the high strain rates outside the bubble, cavitation can also induce chain scission, which provides an additional means to control the molecular weight of the produced polymer. This contribution discusses the possibilities, mechanisms, and challenges of several types of ultrasound‐induced radical polymerizations.
Durability of hydrophilic and antimicrobial zeolite coatings under water immersion
Authors: O'Neill Cory , Beving Derek E. , Chen Wilfred , Yan Yushan 
Published: October 2005

AbstractGravity‐independent water separation within the condensing heat exchangers onboard manned spacecraft is achieved by using hydrophilic fin surfaces that promote the wetting and wicking of the condensate on the fin. It is also important for the fin surfaces to be antimicrobial to prevent the bacteria growth that may thrive in the moist environment of the fin surface. For practical and economical reasons, the coating must also be durable under wet conditions. Ag‐exchanged zeolite A (Ag‐ZA) coatings have been shown to have excellent hydrophilicity and are highly antimicrobial. In this study we show that Ag‐ZA coatings are highly durable under wet conditions, maintaining their hydrophilic and antimicrobial properties even after submersion in water for 8 weeks. The durability of the hydrophilic and antimicrobial properties of Ag‐ZA coating make it a preeminent candidate for use in condensing heat exchangers onboard manned spacecraft. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Depression and suicide attempt as risk factors for incident unprovoked seizures
Authors: Hesdorffer Dale C. , Hauser W. Allen , Olafsson Elias , Ludvigsson Petur , Kjartansson Olafur 
Published: October 2005

AbstractMajor depression has been shown to increase the risk for development of epilepsy, but prior studies have not evaluated whether this is due to specific symptoms of depression. We conducted a population‐based case–control study of all newly diagnosed unprovoked seizures among Icelandic children and adults aged 10 years and older to test the hypothesis that major depression is a risk factor for developing unprovoked seizure and epilepsy, and to address whether specific symptoms of depression account for this increased risk. Cases were matched to the next two same sex births from the population registry. Using standardized interviews, we ascertained symptoms of major depression to make a Diagnostic and Statistical Manual, Fourth Edition (DSM‐IV) diagnosis. A history of major depression was 1.7‐fold more common among cases than among controls (95% confidence interval, 1.1–2.7). A history of attempted suicide was 5.1‐fold more common among cases than among controls (95% confidence interval, 2.2–11.5). Attempted suicide increased seizure risk even after adjusting for age, sex, cumulative alcohol intake, and major depression or number of symptoms of depression. Major depression and attempted suicide independently increase the risk for unprovoked seizure. These data suggest that depression and suicide attempt may be due to different underlying neurochemical pathways, each of which is important in the development of epilepsy. Ann Neurol 2005
Reactive compatibilization of polystyrene/poly(ethylene–co–vinyl acetate) (EVA) blends
Authors: Soares Bluma G. , Cario Francisco O. 
Published: October 2005

AbstractA reactive compatibilizer, mercapto‐functionalized EVA (EVASH), in combination with styrene‐butadiene block copolymer (SBS), was used to compatibilize the blends of polystyrene (PS) and ethylene–vinyl acetate copolymer (EVA). The reactive compatibilization was confirmed by the presence of insoluble material and from dynamic‐mechanical analysis. In addition to a more uniform morphology with small phase size, the compatibilization also provided excellent stabilization of the morphology, with an almost complete suppression of coarsening during annealing. As a consequence, a substantial increase on the elongation at break without significant influence on ultimate tensile strength was achieved for compatibilized blends with different compositions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 14–22, 2006
Parameters affecting the free‐radical melt grafting of maleic anhydride onto linear low‐density polyethylene in an internal mixer
Authors: Razavi Aghjeh M. K. , Nazockdast H. , Assempour H. 
Published: October 2005

AbstractOur main objective of this study was to study the parameters affecting the free‐radical melt grafting of maleic anhydride (MA) onto linear low‐density polyethylene (LLDPE) with dicumyl peroxide (DCP) in an internal mixer. The degree of grafting (DG) was measured with titrometry and Fourier transform infrared spectroscopy. The extent of chain‐branching/crosslinking was evaluated with gel content and melt flow index measurements. The flow behavior and melt viscoelastic properties of the grafted samples were measured by using rheometric mechanical spectrometry. Feeding order, DCP and MA concentration, reaction temperature, rotor speed, and grade of LLDPE were among parameters studied. The results show that the reactant concentration (MA and DCP) played a major role in the determination of the grafting yield and the extent of the chain‐branching/crosslinking as competitive side reactions. The order of feeding also had an appreciable effect on the DG and the side reactions. Increasing the rotor speed increased the grafting yield and reduced side reactions by means of intensification of the mixing of reactants into the polyethylene (PE) melt. Chain‐branching dominated the side reactions for lower molecular weight PE, whereas for higher molecular weight PE, chain‐branching led to crosslinking and gel formation. The results of the melt viscoelastic measurements on the grafted samples provided great insight into the understanding of the role of influential parameters on the extent of side reactions and resulting changes in the molecular structure of the grafted samples. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 141–149, 2006
Isotactic polypropylene microfiber prepared by continuous laser‐thinning method
Authors: Suzuki Akihiro , Narusue Shinichi 
Published: October 2005

AbstractAn isotactic polypropylene (i‐PP) microfiber was continuously produced by using a carbon dioxide (CO2) laser‐thinning apparatus developed in our laboratory. The CO2 laser‐thinning apparatus could wind up the obtained microfiber in the range of 100 m min−1 to 2500 m min−1. The diameter of the microfiber decreased and its birefringence increased with increasing winding speed. When the microfiber obtained by irradiating the CO2 laser operated at a power density of 31.8 W cm−2 to the original fiber supplied at 0.30 m min−1 was wound at 1,387 m min−1, the obtained microfiber had a diameter of 3.5 μm and a birefringence of 25 × 10−3. The draw ratio calculated from the supplying and the winding speeds was 4,623‐fold. The SEM photographs showed that the obtained microfibers had a smooth surface without a surface roughened by a laser‐ablation and were uniform in diameter. The wide‐angle X‐ray diffraction photographs of the microfibers wound at 848 and 1,387 m min−1 showed the existence of the oriented crystallites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 27–31, 2006
Photomechanical degradation of thermoplastic elastomers
Authors: Bhowmick Anil K. , Ray Sudip , Shanmugharaj A. M. , Heslop J. , Köppen N. , White J. R. 
Published: October 2005

AbstractThe photodegradation of thermoplastic elastomers designed for outdoor applications was studied with laboratory ultraviolet (UV) exposure in the unstrained state and under tensile strain (25 and 50%). Strained exposure caused a reduction of the strain to failure in subsequent tensile tests. For some combinations of material and exposure conditions, some recovery of extensibility occurred between 2 and 4 weeks. Microscopic examination revealed that this was probably due to embrittlement of the surface region that was sufficiently severe that surface cracks did not propagate into the interior and that the observed recovery did not correspond to repair or improvement of the material. Shielding the sample surface from UV irradiation reduced the formation of surface cracking very significantly, and it was deduced that the principal cause of degradation was photooxidation rather than ozone attack. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 150–161, 2006
Reverse atom transfer radical polymerization of acrylonitrile
Authors: Hou Chen , Qu Rongjun , Ying Liang , Wang Chengguo 
Published: October 2005

AbstractFeCl3 coordinated by succinic acid was used as the catalyst for the first time in azobisisobutyronitrile‐initiated reverse atom transfer radical polymerization of acrylonitrile (AN). N,N‐dimethylformamide (DMF) was used as a solvent to improve the solubility of the ligand. A FeCl3 to succinic acid ratio of 0.5 not only gives the best control of molecular weight and its distribution but also provides rather rapid reaction rate. Effects of different solvents on polymerization of AN were also investigated. The rate of the polymerization in DMF is faster than that in propylene carbonate and toluene. The molecular weight of polyacrylonitrile agrees reasonably well with the theoretical molecular weight in DMF. The rate of polymerization increases with increasing the polymerization temperature, and the apparent activation energy was calculated to be 64.8 kJ mol−1. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 32–36, 2006
Swelling–deswelling kinetics of poly(N‐isopropylacrylamide) hydrogels formed in PEG solutions
Authors: Dogu Yucel , Okay Oguz 
Published: October 2005

AbstractA series of poly(N‐isopropylacrylamide) (PNIPA) hydrogels was prepared by free‐radical crosslinking copolymerization of N‐isopropylacrylamide (NIPA) and N,N′‐methylenebisacrylamide (BAAm) in aqueous solutions of poly(ethylene glycol) of molecular weight 300 g/mol (PEG). The amount of PEG in the polymerization solvent, the crosslinker (BAAm) content, and the gel preparation temperature (Tprep) were varied in the gelation experiments. The hydrogels were characterized by the equilibrium swelling and elasticity tests as well as by the measurements of the deswelling–reswelling kinetics of the hydrogels in response to a temperature change between 25 and 48°C. The rate of deswelling of the swollen gel increases while the rate of reswelling of the collapsed gel decreases as the amount of PEG in the polymerization solvent is increased or as the crosslinker content is decreased. The Tprep effect on the swelling kinetics of the hydrogels was only observed if the PEG content of the polymerization solvent is less than 20%, which is explained with the screening of H‐bonding interactions in concentrated PEG solution. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 37–44, 2006
Nano‐carbon black filled Lyocell fiber as a precursor for carbon fiber
Authors: Zhang Huihui , Guo Liwei , Shao Huili , Hu Xuechao 
Published: October 2005

AbstractIn this work, Lyocell fibers filled with various amounts of carbon black were prepared. Wide angle X‐ray diffraction (WAXD) results showed that carbon black filled Lyocell fibers still had a cellulose II crystal structure and kept the characteristic peak of carbon black at the same time. The results of mechanical properties showed a slight reduction in the carbon black filled Lyocell fiber. Moreover, the heat stabilities of the carbon black filled Lyocell fibers showed no obvious change. The residue of carbon black filled Lyocell fiber at 1000°C was higher than that of Lyocell fiber, implying higher carbon yield could be obtained for the carbon black filled Lyocell precursor. Scanning electron microscopy (SEM) experiments showed that the surface and the cross section of carbon black filled Lyocell fiber were smooth and round, which are consistent with the carbon fiber precursor. The WAXD pattern of carbon black filled Lyocell‐based carbon fiber was different from that of Lyocell‐based carbon fiber. The addition of carbon black transfers the diffraction peak of carbon fiber while keeping the characteristic structure of carbon black. The results of mechanical properties of carbon fibers show that, if an appropriate amount of carbon black was chosen, carbon fiber with better properties than Lyocell‐based carbon fiber could be obtained by using the carbon black filled Lyocell fibers as the precursor. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 65–74, 2006
Modeling of adsorption of anionic surfactants onto cationized lignocellulosic materials
Authors: Zghida Haïfa , Gauthier Robert , Helal Ahmed , Bartegi Aghlab 
Published: October 2005

AbstractCationized lignocellulosic materials (cotton fibers, wood sawdust, and maize‐cob flour) are prepared by grafting quaternary ammonium groups for use as scavengers for anionic surfactants. Generally, rapid adsorption occurs and at saturation leads to a stoichiometric ratio of cationic sites and anionic surfactants such as sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, and sodium oleate. Modeling of these adsorptions is tested using Langmuir, Freundlich, or Jossens equations, the latter giving the best fit with experimental data. The results are compared with the adsorption of chromate and dichromate anions on the same sorbents. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 82–87, 2006
Performance evaluation of high‐cis 1,4‐polybutadienes
Authors: Pires Neusa M. T. , Ferreira Antônio A. , de Lira Clóvis H. , Coutinho Paulo L. A. , Nicolini Luiz F. , Soares Bluma G. , Coutinho Fernanda M. B. 
Published: October 2005

AbstractThis article reports the results of a study comparing commercially available high‐cis polybutadiene rubbers (BRs) proceeding from different production technologies and bearing distinct structural characteristics. The microstructure of these polymers was characterized by Fourier transform infrared spectroscopy; molecular weight and polydispersity values were characterized by size exclusion chromatography (SEC). The degree of branching was characterized by SEC and dynamic mechanical rheological testing (RPA 2000). Glass‐transition temperature was characterized by differential scanning calorimetry, and rheological properties were characterized with an oscillating rheometer rubber process analyzer (RPA 2000). Tire tread formulations were prepared with carbon black HAF N‐339 as a reinforcement filler, and we compared the mechanical properties and performance of the different elastomer compositions. The compositions were characterized by their rheological properties, tensile resistance, resistance to abrasion, resistance to tearing, permanent deformation, resilience, and fatigue properties. The tested compositions obtained from BRs with distinct structural characteristics showed different performances. Neodymium‐salt‐based catalysts produced BRs with higher cis‐1,4 levels and higher linearities. These polymer compositions also showed higher performances in abrasion resistance, fatigue resistance, and resilience tests. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 88–99, 2006
Studies on the electronic transport and optical properties of some new chelate modified polysulfones in thin films
Authors: Rusu G. I. , Airinei A. , Baban C. , Rusu G. G. , Mardare Diana , Rusu Mihaela 
Published: October 2005

AbstractThe studied polymers (chelate modified polysulfones) have been prepared by the polycondensation reaction between chloro‐end‐capped polysulfones and bis(2,4‐dihydroxybenzaldehyde)Cu2+ in the dymethyl sulfoxide/dichlormethane system, in the presence of an aqueous sodium hydroxide solution. The temperature dependence of electrical conductivity and Seebeck coefficient of the respective polymers was investigated using thin‐film samples, deposited from chloroform solutions onto glass substrates. The polymers under study have typical semiconducting properties. The values of some characteristic parameters of the investigated polymers (for example, activation energy of electrical conduction, ratio of carrier mobilities, etc.) have been determined. The nature of the electrical conduction mechanism is discussed. The values of the optical bandgap energy are determined from the absorption spectra. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 100–106, 2006