bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of low salinity on cadmium accumulation and calcium homeostasis in the shore crab (carcinus maenas) at fixed free Cd2+ concentrations
Authors: Burke Jonathan , Handy Richard D. , Roast Stephen. D. 
Published: November 2004

Abstract
Increased Cd toxicity at low salinity has been attributed to increased free Cd2+ ion concentration ([Cd2+]sw), but transfer to dilute seawater also stimulates physiological ionic regulation in crabs. In this study, Cd accumulation and Ca homeostasis in the shore crab (Carcinus maenas) were explored at fixed [Cd2+]sw to reveal the physiological events during sublethal Cd exposure. Crabs were exposed to 3.4 or 34 μg/L [Cd2+]sw in both 100% seawater (SW) and 33% SW for up to 10 d and sampled for hemolymph composition as well as gill and hepatopancreas Ca, Cd, and Ca-ATPase activity. Cadmium exposure ameliorated the expected fall in hemolymph osmotic pressure and NaCl at low salinity and generally protected tissue Ca from decline. Cadmium exposure alone (within salinity) inhibited Ca-ATPase, but this was offset by stimulation of Ca-ATPase at low salinity. The Ca-ATPase activity in the anterior and posterior gills showed different responses to Cd/low salinity stress. Crabs were more sensitive to a 10-fold increase in [Cd2+]sw at low salinity. Overall, we conclude that exposure to a fixed sublethal [Cd2+]sw reveals a compensatory physiological response that is driven primarily by salinity rather than Cd2+ free ion concentration. Physiological responses are therefore important during low-level Cd exposure in dilute seawater.
Assessment of the mutagenic potency of sewage sludges contaminated with polycyclic aromatic hydrocarbons by an Ames fluctuation assay
Authors: Pérez Assay Sandra , Reifferscheid Georg , Eichhorn Peter , Barceló Damià 
Published: November 2004

Abstract
The mutagenicity of crude extracts and subfractions of two samples of a reference sewage sludge material and two sewage sludges from two wastewater treatment plants (WWTP), one urban and the other one urban mixed with industrial, was assessed using an Ames fluctuation assay based on 384-well microtiter plates with liquid cultures. Crude extracts of sludges were obtained by ultrasonic extraction with dichloromethane/methanol, and further column fractionation yielded two fractions, one of which containing mutagenic polycyclic aromatic hydrocarbons (PAHs). Quantitative analysis performed by gas chromatographymass spectrometry gave sum concentrations of the 16 PAHs listed as priority pollutants by the U.S. Environmental Protection Agency at levels between 1,305 and 2,442 μg/kg. Subjecting crude extracts and column fractions to the mutagenicity assay with Salmonella strains TA98 and TA100 provided good qualitative correlation between the presence of mutagenic PAH and the induction of gene mutations. In general, the crude extracts and the PAH-fractions induced positive responses in the assay with both bacterial strains on metabolic activation by S9 rat-liver homogenate, whereas direct-acting mutagens were not detectable. In the assay with the real sludge samples of two different WWTPs, TA98 proved to be more sensitive than TA100; however, similar sensitivities of the tester strains were observed for two reference sewage sludge materials of the same origin. The outcomes of the Ames fluctuation assay demonstrated its performance as a cost-effective and relatively rapid screening tool to assess the genotoxic potential of complex environmental samples.
A protocol to estimate the release of anthropogenic hydrocarbons from contaminated soils
Authors: Loehr Raymond C. , Lamar Michael R. , Poppendieck Dustin G. 
Published: November 2004

Abstract
An operational protocol, appropriate for a tier 1 or tier 2 type relative risk evaluation of a site that has polycyclic aromatic hydrocarbon (PAH) or petroleum hydrocarbon impacted soils, was developed to estimate the fraction of anthropogenic hydrophobic hydrocarbons that will be released rapidly from such soils. The development of this protocol used over 400 datasets from 40 different field samples to establish and verify the operational protocol. The datasets resulted from four-month kinetic desorption studies of these field samples. Based on the chemicals evaluated, the protocol has greatest application to two, three, and four ring-PAH and to diesel range aliphatic hydrocarbons. The protocol is a simple batch desorption analysis that uses established methods and is conducted for 7 d. The protocol results were verified with specific correlation relationships (r2 = 0.81 to 0.96) to estimate the rapidly releasing fraction (F value) that is obtained in a full, four-month chemical release evaluation.
Influence of dissolved organic matter source on silver toxicity to Pimephales promelas
Authors: VanGenderen Eric J. , Ryan Adam C. , Tomasso Joseph R. , Klaine Stephen J. 
Published: November 2004

Abstract
In the environment, the formation of organic and inorganic silver complexes can decrease Ag bioavailability (toxicity) to aquatic organisms. However, current water quality regulations do not consider the protective effects of water quality parameters such as dissolved organic carbon (DOC) concentration. To determine the effect of DOC concentration and source on silver toxicity, nine different natural organic matter isolates were used in 96-h static-renewal toxicity tests with fathead minnow (Pimephales promelas). The 96-h dissolved silver median lethal concentrations (LC50) among different sources of dissolved organic matter varied by up to fivefold (4.5–23.3 μg/L). Further, toxicity tests with organic matter from the site with the lowest 96-h LC50 value suggested only limited additional attenuation of silver toxicity when DOC concentration was increased from 5.1 to 14.0 mg/L. With this site excluded, we found little more than a twofold difference among 96-h dissolved Ag LC50s for the remaining sources (10.1–23.3 μg/L). However, significant toxicological differences among sites remained. It was apparent that organic matter from different sources varied both chemically and toxicologically, but no conclusions could be drawn that related compositional variation to observed Ag toxicity for these isolates.
Evaluation of polychlorinated biphenyl bioaccumulation patterns in white sea urchins (Lytechinus pictus) using multiple approaches
Authors: Noblet James A. , Zeng Eddy Y. , Ritter Kerry J. 
Published: November 2004

Abstract
The bioaccumulation of polychlorinated biphenyls (PCBs) from three amended field-contaminated sediments (with total PCB concentrations of ∼4, 10, and 100 μg/g dry wt) by white sea urchins (Lytechinus pictus) was evaluated using multiple statistical and theoretical approaches. Similarity analysis of the PCB bioaccumulation patterns, based on the concept of ecological communities, showed that the PCB patterns in the sea urchins and source sediments were essentially identical for all three sediment concentrations. However, affinity analysis did show some preference for bioaccumulation of higher-molecular-weight and more hydrophobic congeners by the urchins. The affinity analysis also showed that within a homologous series, bioaccumulation increased with increasing hydrophobicity. The biota-sediment accumulation factor (BSAF) profiles for the two lower concentration sediments (A and B) were found to be statistically different from the high concentration sample (sediment C) by a multivariate analysis of variance (MANOVA). The relationship between the measured apparent organic carbon-normalized partition coefficients (KOC) and octanol-water partition coefficient (Kow) (log based) suggested a significant departure from thermodynamic equilibrium. A nonequilibrium, steady-state bioaccumulation model was found to correctly predict the observed experimental bioaccumulation patterns. To improve the model performance, a hydrophobic term was introduced to account for the drop-off in BSAF profiles with log Kow ≥ 6.5. This study showed that nonequilibrium, steady-state models are far superior to equilibrium partitioning-based models for understanding the bioaccumulation of organic chemicals by sea urchins.
Developmental toxicity of in ovo exposure to polychlorinated biphenyls: II. Effects of maternal or paternal exposure on second-generation nestling American
Authors: Fernie Kim , Bortolotti Gary , Drouillard Ken , Smits Judit , Marchant Tracy 
Published: November 2004

Abstract
The development of second-generation nestling American kestrels (Falco sparverius) was altered by in ovo exposure of only one parent to polychlorinated biphenyls (PCBs). Polychlorinated biphenyls appear to alter nestling development through both maternally and paternally mediated effects. In 1998, F0 parent kestrels consumed approximately 5 to 7 μg total PCBs/g bird/d (Aroclors® 1248:1254: 1260) for approximately 100 d prior to eggs hatching; these eggs, containing total PCB concentrations of 34.1 μg/g, produced 13 F1 offspring, which were then paired in 1999 with unexposed kestrels to examine developmental effects of maternal or paternal in ovo PCB exposure. Using a toxicokinetics model, eggs from the maternally exposed group had predicted PCB levels of 0.03 to 0.34 μg/g, with enriched higher chlorinated congeners. Polychlorinated biphenyl concentrations in eggs of all generations have recently been found in eggs and nestlings of free-ranging eagles. Consistent with the first generation, maternally exposed F2 females generally were larger, had altered growth rates, and delayed maximal growth and fledging compared with control females. Maternally exposed F2 males were heavier but had shorter bones, grew more quickly and earlier, and fledged 2 d later than control males. In the maternally exposed group, concentrations of plasma triiodothyronine were elevated in F2 females but suppressed in F2 males. Paternally exposed F2 hatchlings of both sexes were comparable in size to controls with the exception of having longer tarsi bones, but subsequently showed slower, delayed growth (both sexes) and fledging (females) and lower thyroxine concentrations (males). The alterations in thyroid hormones in the F2 generation are discussed in light of the enrichment of higher chlorinated PCB congeners and hydroxylated PCB congeners. The developmental changes in the kestrel nestlings are likely a function of several possible mechanisms involving maternal PCB deposition, parental behavior, and neurobehavioral and endocrine–thyroid function in nestlings.
Preparation and Multicolor Electrochromic Performance of a WO3/Tris(2,2′‐bipyridine)ruthenium(II)/Polymer Hybrid Film
Authors: Yagi Masayuki , Sone Koji , Yamada Miki , Umemiya Saori 
Published: November 2004

AbstractA tungsten trioxide (WO3)/tris(2,2′‐bipyridine)ruthenium(II) ([Ru(bpy)3]2+; bpy=2,2′‐bipyridine)/poly(sodium 4‐styrenesulfonate) (PSS) hybrid film was prepared by electrodeposition from a colloidal triad solution containing peroxotungstic acid (PTA), [Ru(bpy)3]2+, and PSS. A binary solution of [Ru(bpy)3]2+ and PTA (30 vol % ethanol in water) gradually gave an orange precipitate, possibly caused by the electrostatic interaction between the cationic [Ru(bpy)3]2+ and the anionic PTA. The addition of PSS to the binary PTA/[Ru(bpy)3]2+ solution remarkably suppressed this precipitation and caused a stable, colloidal triad solution to form. The spectrophotometric measurements and lifetime analyses of the photoluminescence from the excited [Ru(bpy)3]2+ ion in the colloidal triad solution suggested that the [Ru(bpy)3]2+ ion is partially shielded from electrostatic interaction with anionic PTA by the anionic PSS polymer chain. The formation of the colloidal triad made the ternary [Ru(bpy)3]2+/PTA/PSS solution much more redox active. Consequently, the rate of electrodeposition of WO3 from PTA increased appreciably by the formation of the colloidal triad, and fast electrodeposition is required for the unique preparation of this hybrid film. The absorption spectrum of the [Ru(bpy)3]2+ ion in the film was close to its spectrum in water, but the photoexcited state of the [Ru(bpy)3]2+ ion was found to be quenched completely by the presence of WO3 in the hybrid film. The cyclic voltammogram (CV) of the hybrid film suggested that the [Ru(bpy)3]2+ ion performs as it is adsorbed onto WO3 during the electrochemical oxidation. An ohmic contact between the [Ru(bpy)3]2+ ion and the WO3 surface could allow the electrochemical reaction of adsorbed [Ru(bpy)3]2+. The composition of the hybrid film, analyzed by electron probe microanalysis (EPMA), suggested that the positive charge of the [Ru(bpy)3]2+ ion could be neutralized by partially reduced WO3− ions, in addition to Cl− and PSS units, based on the charge balance in the film. The electrostatic interaction between the WO3− ion and the [Ru(bpy)3]2+ ion might be responsible for forming the electron transfer channel that causes the complete quenching of the photoexcited [Ru(bpy)3]2+ ion, as well as the formation of the ohmic contact between the [Ru(bpy)3]2+ ion and WO3. A multicolor electrochromic performance of the WO3/[Ru(bpy)3]2+/PSS hybrid film was observed, in which transmittances at 459 and 800 nm could be changed, either individually or at once, by the selection of a potential switch. Fast responses, of within a few seconds, to these potential switches were exhibited by the electrochromic hybrid film.
Macroscopic Order and Electro‐Optic Response of Dipolar Chromophore–Polymer Materials
Authors: Pereverzev Yuriy V. , Prezhdo Oleg V. , Dalton Larry R. 
Published: November 2004

AbstractThis Minireview considers the key factors that govern the organization of macroscopic polarization in nonlinear optical systems obtained by electric poling of organic dipolar chromophores dissolved in polymer matrices. The macroscopic electric polarization depends on the thermodynamic state of the dipole system. The dependence of the paraelectric and antiferroelectric states of dipolar chromophores on the chromophore concentration and the strength of the poling field is discussed. Phase transitions between the para‐ and antiferroelectric states are investigated within the limits of the Ising and isotropic models for the chromophore dipoles and are considered for varying chromophore concentration, poling field strength, and macroscopic shape of the sample used for poling. The macroscopic polarization and electro‐optic coefficient of the material change drastically upon phase transition. The theories are compared with the experimental data on the electro‐optic coefficient dependence on the chromophore concentration. The isotropic dipole model shows excellent agreement with experiment for the chromophore systems most commonly used in nonlinear optics.
Activating CD94:NKG2C and inhibitory CD94:NKG2A receptors are expressed by distinct subsets of committed CD8+ TCR αβ lymphocytes
Authors: Arlettaz Lionel , Villard Jean , de Rham Casimir , Degermann Sylvie , Chapuis Bernard , Huard Bertrand , Roosnek Eddy 
Published: November 2004

AbstractA subset of CD8+ T cells express the natural killer cell receptors CD94:NKG2A or CD94:NKG2C. We found that although many CD8+ T cells transcribe CD94 and NKG2C, expression of a functional CD94:NKG2C receptor is restricted to highly differentiated effector cells. CD94:NKG2A is expressed by a different subset consisting of CCR7+ memory cells and CCR7– effector cells. Since NKG2A can only be induced on naive CD8+ T cells while CD94– memory cells are refractory, it is likely that commitment to the CD94:NKG2A+ subset occurs during the first encounter with antigen. CCR7+CD94:NKG2A+ T cells recirculate through lymph nodes where upon activation, they produce large quantities of IFN‐γ. These cells occur as a separate CD94:NKG2A+ T cell lineage with a distinct TCR repertoire that differs from that of the other CD8+CD94– T cells activated in situ.
CC chemokine receptor 2 regulates leukocyte recruitment and IL‐10 production during acute polymicrobial sepsis
Authors: Feterowski Carolin , Mack Matthias , Weighardt Heike , Bartsch Bernadett , Kaiser‐Moore Simone , Holzmann Bernhard 
Published: November 2004

AbstractChemokine receptors are important for recruiting leukocytes to sites of infection and may contribute to immune cell activation. The present study investigated the role of the chemokine receptor CCR2 in polymicrobial septic peritonitis. The results showed that peritoneal production of the CCR2 ligands CCL2 and CCL12 in septic mice was largely independent of the common Toll‐like receptor signaling adaptor MyD88. Antibody blockade of CCR2 reduced the recruitment of macrophages and neutrophils to the infected peritoneal cavities of both wild‐type and MyD88‐deficient mice, suggesting that CCR2 engagement contributes to the MyD88‐independent cellular response against polymicrobial septic peritonitis. Notably, administration of blocking CCR2 antibodies markedly increased local and systemic IL‐10 levels in septic wild‐type mice, whereas IL‐10 was not detected in MyD88‐deficient mice irrespective of whether CCR2 was blocked or not. Inhibition of CCR2 directly augmented Toll‐like receptor‐induced IL‐10, but not TNF and IL‐6, production of macrophages in vitro. Concomitant with enhanced IL‐10 production, CCR2 blockade caused impaired bacterial clearance and aggravated kidney injury in wild‐type, but not MyD88‐null mice. These results indicate that CCR2 engagement modulates the innate immune response to polymicrobial septic peritonitis by both MyD88‐dependent and ‐independent processes and suggest that a major function of CCR2 in sepsis is to attenuate IL‐10 production and IL‐10‐mediated suppression of host defense.
Effector and regulatory T cells derived from the same T cell clone differ in MHC class II‐peptide multimer binding
Authors: Nolte‐‘t Hoen Esther N. M. , Amoroso Maria Grazia , Veenstra Jetty , Grosfeld‐Stulemeyer Mayken C. , van Eden Willem , Broeren Chris P. M. , Wauben Marca H.  M. 
Published: November 2004

AbstractMHC class II‐peptide multimers are a valuable tool for antigen‐specific detection of CD4+ T cells. However, it has been proposed that T cells in a hypo‐responsive state can have diminished binding of such multimers. In the present study, we investigated this phenomenon at the clonal level. We found that anergic CD4+ T cells had a reduced capacity to bind MHC class II‐peptide multimers compared to their non‐anergic counterparts. Increasing the incubation temperature, time, or MHC‐peptide valency could not equalize multimer binding by anergic and non‐anergic T cells. Neither anergic T cells nor non‐anergic T cells internalized the MHC class II‐peptide dimers efficiently, and in both cases the dimers bound to the plasma membrane at locations containing a low amount of raft‐associated lipids. Disruption of lipid rafts, however, led to decreased dimer binding by non‐anergic T cells and to a lesser extent by anergic T cells. Finally, we show that the depth of the anergic state of the T cell, which determines its ability to regulate other T cell responses, correlates with the reduced dimer binding. We here demonstrate for the first time differential MHC class II‐peptide multimer binding by regulatory (anergic) and effector T cells with identical TCR.
Imaging and analysis of nanowires
Authors: Bell David C. , Wu Yue , Barrelet Carl J. , Gradečak Silvija , Xiang Jie , Timko Brian P. , Lieber Charles M. 
Published: November 2004

AbstractWe used vapor‐liquid‐solid (VLS) methods to synthesize discrete single‐element semiconductor nanowires and multicomposition nanowire heterostructures, and then characterized their structure and composition using high‐resolution electron microscopy (HRTEM) and analytical electron microscopy techniques. Imaging nanowires requires the modification of the established HRTEM imaging procedures for bulk material to take into consideration the effects of finite nanowire width and thickness. We show that high‐resolution atomic structure images of nanowires less than 6 nm in thickness have lattice “streaking” due to the finite crystal lattice in two dimensions of the nanowire structure. Diffraction pattern analysis of nanowires must also consider the effects of a finite structure producing a large reciprocal space function, and we demonstrate that the classically forbidden 1/3 {422} reflections are present in the [111] zone axis orientation of silicon nanowires due to the finite thickness and lattice plane edge effects that allow incomplete diffracted beam cancellation. If the operating conditions are not carefully considered, we found that HRTEM image delocalization becomes apparent when employing a field emission transmission electron microscope (TEM) to image nanowires and such effects have been shown to produce images of the silicon lattice structure outside of the nanowire itself. We show that pseudo low‐dose imaging methods are effective in reducing nanowire structure degradation caused by electron beam irradiation. We also show that scanning TEM (STEM) with energy dispersive X‐ray microanalysis (EDS) is critical in the examination of multicomponent nanowire heterostructures. Microsc. Res. Tech. 64:373–389, 2004. © 2004 Wiley‐Liss, Inc.
Probing photonic and optoelectronic structures by Apertureless Scanning Near‐Field Optical Microscopy
Authors: Bachelot Renaud , Lerondel Gilles , Blaize Sylvain , Aubert Sebastien , Bruyant Aurelien , Royer Pascal 
Published: November 2004

AbstractThis report presents the Apertureless Scanning Optical Near‐Field Microscope as a powerful tool for the characterization of modern optoelectronic and photonic components with sub‐wavelength resolution. We present an overview of the results we obtained in our laboratory over the past few years. By significant examples, it is shown that this specific probe microscopy allows for in situ local quantitative study of semiconductor lasers in operation, integrated optical waveguides produced by ion exchange (single channel or Y junction), and photonic structures. Microsc. Res. Tech. 64:441–452, 2004. © 2004 Wiley‐Liss, Inc.
Electronic management of change process
Authors: Garland R. Wayne 
Published: November 2004

AbstractProtection safeguards must reliably and effectively detect, diagnose, and control process deviations before the deviations can result in loss events such as fires and explosions. Any process change can potentially affect protection safeguards. Therefore, it is critical to identify process changes and assess their impact on layers of protection, safety instrumented systems (SIS), operating procedures, and alarms. Process change designs should be reviewed, and any needed modifications to safeguards should be implemented as part of the change. Existing management of change processes rely primarily on human knowledge and interaction among various functional groups, making them highly susceptible to human error. In an effort to reduce the risk involved with process changes, we developed a standardized, electronic management of change (eMOC) system and process, which facilitates reviews of process changes, update of company process safety information (PSI), and notification of affected personnel. It also enhances the ability to track and audit changes. Implementation included all necessary software and development/selection of training. The system is web based and includes a standardized electronic form with checklists (including some flexibility for site or division variation) and an automatic workflow routing. All system functions were automated including routing of documents and drawings, record keeping, approvals, notification, tracking, reporting, printing, searching, and audit trails. The process has now been in use for more than 1.5 years and has been used for over 3500 process changes with good results. The major advantages of the system identified by users are tracking, documentation and compliance, automatic routing, and automatic reminders. © 2004 American Institute of Chemical Engineers Process Saf Prog, 2004