bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamics of 17α-Ethynylestradiol exposure in rainbow trout (Oncorhynchus mykiss): Absorption, tissue distribution, and hepatic gene expression pattern
Authors: Skillman Ann D. , Nagler James J. , Hook Sharon E. , Small Jack A. , Schultz Irvin R. 
Published: October 2006

Abstract17α-Ethynylestradiol (EE2) is a synthetic estrogen identified in sewage effluents. To understand better the absorption kinetics of EE2 and the induction of vitellogenin (VTG) and estrogen receptor α (ERα) mRNA, we subjected male rainbow trout (Onchorynchus mykiss) to continuous water exposures of 125 ng/L of EE2 for up to 61 d. Trout were either repetitively sampled for blood plasma or serially killed at selected time intervals. Vitellogenin, ERα mRNA, and EE2 were measured using enzymelinked immunosorbent assay and using quantitative polymerase chain reaction and gas chromatography–mass spectrometry, respectively. In separate experiments, trout were exposed to EE2 for 7 d, and hepatic gene expression was assessed using a low- and high-density cDNA microarray. The EE2 was rapidly absorbed by the trout, with an apparent equilibrium at 16 h in plasma and liver. The ERα mRNA levels also increased rapidly, reaching near-peak levels by 48 h. In contrast, plasma levels of VTG continuously increased for 19 d. After 61 d, tissues with the highest levels of VTG were the liver, kidney, and testes. Microarray-based gene expression studies provided unexpected results. In some cases, known estrogen-responsive genes (e.g., ERα) were unresponsive, whereas many of the genes that have no apparent link to estrogen function or EE2 toxicity were significantly altered in expression. Of the two microarray approaches tested in the present study, the high-density array appeared to be superior because of the improved quality of the hybridization signal and the robustness of the response in terms of the number of genes identified as being EE2 responsive.
Multilevel evaluation of nonylphenol toxicity in fourth-instar larvae ofChironomus riparius(Diptera, Chironomidae)
Authors: Lee Se-Bum , Choi Jinhee 
Published: October 2006

AbstractThe multilevel biomarker approach, wherein different biological responses ranging from molecular to physiological are evaluated, is essential to determine the general health status of an organism in pollutant biomonitoring programs. Furthermore, it permits extrapolation of the relationship between responses at different levels of biological organization. The aim of this study was to develop, under laboratory conditions, a multilevel biomarker approach for evaluating the toxicological response of nonylphenol (NP) in Chironoms riparius. To investigate the effect of NP on C. riparius, an acute toxicity test was performed measuring 24-h median lethal concentration. Responses on molecular, biochemical, and physiological levels were subsequently investigated on sublethal exposure. To assess molecular-level effects, we investigated DNA damage and the expression of heat shock protein 70 (HSP70) gene, whereas biochemical-level responses were determined by investigation of various enzymes activities. Growth and development were investigated as physiological-level responses. The biomarkers found to be most sensitive to NP treatment were HSP70 gene expression and DNA strand break. After having been studied with lower concentration levels with longer exposure period, these biomarkers could be considered early warning signs of exposure to low concentrations of chemical exposure. Statistically significant correlations were observed between DNA damage and the development descriptor; however, a mechanistic study appears to be necessary to establish causal relationships. This approach could be applied in environmental biomonitoring programs, and the data obtained from this study should constitute an important contribution to knowledge of the toxicology of NP in C. riparius, about which little data is available.
Bioavailability of polycyclic aromatic hydrocarbons in field-contaminated Anacostia River (Washington, DC) sediment
Authors: Lu Xiaoxia , Reible Danny D. , Fleeger John W. 
Published: October 2006

AbstractSediment–water partitioning behavior and bioavailability of five polycyclic aromatic hydrocarbons (PAHs; phenanthrene, pyrene, chrysene, benzo[k]fluoranthene, and benzo[a]pyrene) were measured in field-contaminated sediment collected from moderately polluted regions of the Anacostia River (Washington, DC, USA). Much of the sediment PAH burden was resistant to desorption: Effective partition coefficients were 2- to 10-fold greater than expected from literature values, and more than 80% of PAHs remained sorbed after treatment of the sediment with a nonionic polymeric adsorbent (Amberlite XAD-2) for 20 h. Bioaccumulation, elimination, and assimilation of each PAH in the deposit-feeding tubificid oligochaete Ilyodrilus templetoni were measured and compared with the equivalent measurements from laboratory-inoculated sediment. Ilyodrilus templetoni effectively accessed the desorption-resistant fraction of these organic contaminants, as exhibited by high single-gut passage assimilation efficiencies (ASEs) of the five PAHs (60% &lt; ASE &lt; 90%). However, steady-state accumulations of PAHs by I. templetoni were very low and consistent with low pore-water concentrations. The present results suggest that steady-state accumulation of PAHs is controlled by pore-water concentrations and is not necessarily related to route of uptake or assimilation efficiencies.
Survey of carbamate and organophosphorous pesticide export from a South Florida (USA) agricultural watershed: Implications of sampling frequency on ecological risk estimation
Authors: Wilson P. Chris , Foos Jane Ferguson 
Published: October 2006

Abstract
The objectives of the present study were to characterize the presence of selected carbamate and organophosphorous pesticides in Ten Mile Creek (Fort Pierce, FL, USA) and to evaluate the implications of sampling frequency on ecological risk estimates. Ten Mile Creek originates in a predominately agricultural watershed that is drained by an extensive network of crosslinked canals. Water samples were collected daily or every other day and were analyzed for azinphos-methyl, chlorpyrifos, diazinon, dimethoate, ethion, fenamiphos, malathion, methidathion, carbaryl, carbofuran, 3-hydroxycarbofuran, methiocarb, methomyl, oxamyl, and propoxur. A total of 457 samples were analyzed for the carbamate suite, and a total of 332 samples were analyzed for the organophosphorous suite. Carbaryl was detected in eight samples; half of these detections occurred on four consecutive days (October 26–29, 2001) at concentrations ranging from 0.33 to 0.95 μg/L. Methomyl was detected in samples collected on five consecutive days (March 30–April 3, 2002) at concentrations ranging from 1.0 to 2.2 μg/L. Oxamyl was detected in four samples, three of which occurred on three consecutive days (February 17–19, 2002) at concentrations ranging from 6.2 to 6.8 μg/L. The carbamates propoxur, 3-hydroxycarbofuran, carbofuran, and methiocarb were not detected. Diazinon and ethion were the only organophosphorous pesticides detected. Diazinon was detected at 0.9 and 0.7 μg/L on January 5, 2002, and on January 6, 2002, respectively. Ethion was detected in 18 consecutive samples (August 3–20, 2001). The mean, maximum, minimum, and median detected concentrations were 0.38, 0.61, 0.30, and 0.33 μg/L, respectively. Results indicate that frequent sampling is necessary to characterize the presence of these pesticides in this intensively drained watershed. This conclusion also may apply to similar canalized watersheds.
Synthesis of low and high chlorinated toxaphene and comparison of their toxicity by zebrafish (Danio rerio) embryo test
Authors: Kapp Thomas , Kammann Ulrike , Vobach Michael , Vetter Walter 
Published: October 2006

AbstractToxaphene, also known as camphechlor, is a persistent organochlorine pesticide of complex composition. It is technically produced by photochlorination of camphene with elemental chlorine gas under ultraviolet irradiation. In the present work, a novel, laboratory-scale synthesis using sulfuryl chloride as a chlorinating reagent is described. This approach allowed the degree of chlorination of the resulting mixtures to be arbitrarily adjusted by varying the reaction conditions. Both the compositions and the chlorine contents of the low- and high-chlorinated mixtures acquired using this method were similar to those of environmentally altered toxaphene and technical toxaphene, respectively. For comparison of these mixtures regarding toxicity, they were subjected to the zebrafish (Danio rerio) embryo test. Median effective concentrations (EC50s) were calculated based on the presence of lethal and nonlethal embryonic malformations. Surprisingly, low-chlorinated toxaphene, comprising compounds that also are present in environmentally transformed toxaphene, exhibited a twofold-higher toxicity (according to the EC50 for nonlethal effects) toward the test organisms compared with high-chlorinated toxaphene, the composition of which resembled that of the technical product. Although the effective concentrations in the embryo test were much higher than those in aquatic ecosystems burdened with toxaphene, the present results lead to the assumption that toxaphene is becoming more toxic during transformation in the environment. A decrease in the total amount of toxaphene during environmental breakdown would then be compensated for, at least in part, by the higher toxicity of weathered toxaphene in sediments, soils, and biota of contaminated ecosystems.
Effects of an organophosphorous insecticide on survival, fecundity, and development of Hylyphantes graminicola (Sundevall) (Araneae: Linyphiidae)
Authors: Deng Lingling , Dai Jiayin , Cao Hong , Xu Muqi 
Published: October 2006

Abstract
The effects of an organophosphorous insecticide, methamidophos, on fecundity and development of the spider Hylyphantes graminicola (Sundevall) (Araneae: Linyphiidae) were assessed under laboratory conditions. Susceptibility of adults of both sexes to the insecticide and its influence on fecundity of females and development of offspring were investigated. At 48 h after topical application in adults, the median lethal dose (LD50) and 10% lethal dose (LD10) were 0.35 and 0.12 μg/spider, respectively, for males and 0.52 and 0.16 μg/spider, respectively, for females. Methamidophos had detrimental effects on fecundity of females; number of eggs per clutch, total egg mass, and clutch size decreased significantly. The hatching rate of eggs from LD10-treated females was slightly higher than the rate in the controls, but the hatching rate of eggs from LD50-treated females was lower than the rate in the controls. However, no significant differences were observed in hatching time and development time across treatments. Development time of spiderlings from LD50-treated females was significantly longer than the time in the controls, and body sizes of the first spiderlings from insecticide-treated females were larger than those in the controls. However, matured offspring were smaller than those in the controls. It was concluded that methamidophos has long-term effects on H. graminicola, and that this may affect the development of spider populations in the field.
Multi‐model statistical process monitoring and diagnosis of a sequencing batch reactor
Authors: Yoo Chang Kyoo , Villez Kris , Lee In‐Beum , Rosén Christian , Vanrolleghem Peter A. 
Published: October 2006

AbstractBiological processes exhibit different behavior depending on the influent loads, temperature, microorganism activity, and so on. It has been shown that a combination of several models can provide a suitable approach to model such processes. In the present study, we developed a multiple statistical model approach for the monitoring of biological batch processes. The proposed method consists of four main components: (1) multiway principal component analysis (MPCA) to reduce the dimensionality of data and to remove collinearity; (2) multiple models with a posterior probability for modeling different operating regions; (3) local batch monitoring by theT2‐ andQ‐statistics of the specific local model; and (4) a new discrimination measure (DM) to identify when the system has shifted to a new operating condition. Under this approach, local monitoring by multiple models divides the entire historical data set into separate regions, which are then modeled separately. Then, these local regions can be supervised separately, leading to more effective batch monitoring. The proposed method is applied to a pilot‐scale 80‐L sequencing batch reactor (SBR) for biological wastewater treatment. This SBR is characterized by nonstationary, batchwise, and multiple operation modes. The results obtained for the pilot‐scale SBR indicate that the proposed method has the ability to model multiple operating conditions, to identify various operating regions, and also to determine whether the biosystem has shifted to a new operating condition. Our findings show that the local monitoring approach can give more reliable and higher resolution monitoring results than the global model. Biotechnol. Bioeng. 2007;96:687–701. © 2006 Wiley Periodicals, Inc.
Growth of Rhodospirillum rubrum on synthesis gas: Conversion of CO to H2 and poly‐β‐hydroxyalkanoate
Authors: Do Young S. , Smeenk Jerod , Broer Karl M. , Kisting Clint J. , Brown Robert , Heindel Theodore J. , Bobik Thomas A. , DiSpirito Alan A. 
Published: October 2006

AbstractTo examine the potential use of synthesis gas as a carbon and energy source in fermentation processes, Rhodospirillum rubrum was cultured on synthesis gas generated from discarded seed corn. The growth rates, growth and poly‐β‐hydroxyalkanoates (PHA) yields, and CO oxidation/H2 evolution rates were evaluated in comparison to the rates observed with an artificial synthesis gas mixture. Depending on the gas conditioning system used, synthesis gas either stimulated or inhibited CO‐oxidation rates compared to the observations with the artificial synthesis gas mixture. Inhibitory and stimulatory compounds in synthesis gas could be removed by the addition of activated charcoal, char‐tar, or char‐ash filters (char, tar, and ash are gasification residues). In batch fermentations, approximately 1.4 mol CO was oxidized per day per g cell protein with the production of 0.75 mol H2 and 340 mg PHA per day per g cell protein. The PHA produced from R. rubrum grown on synthesis gas was composed of 86% β‐hydroxybutyrate and 14% β‐hydroxyvalerate. Mass transfer of CO into the liquid phase was determined as the rate‐limiting step in the fermentation. Biotechnol. Bioeng. 2007;97: 279–286. © 2006 Wiley Periodicals, Inc.
Effective immobilization of subunit protein in mesoporous silica modified with ethanol
Authors: Itoh Tetsuji , Ishii Ryo , Ebina Takeo , Hanaoka Takaaki , Ikeda Takuji , Urabe Yoko , Fukushima Yoshiaki , Mizukami Fujio 
Published: October 2006

AbstractEthoxylated FSM‐type mesoporous silica (folded‐sheet mesoporous material) with a pore diameter of 6.2 nm (FSM6.2) remarkably enhances rigidly of the structure in aqueous solutions. The esterified material could be used successfully as an adsorbent to accommodate subunit protein, methemoglobin (Fe3+). Furthermore, methemoglobin (Fe3+) in the pores of ethoxy‐FSM is maintained a peroxidase activity similar to the native, indicating methemoglobin retains its fore subunit structure in the pores of FSM6.2. Biotechnol. Bioeng. 2007;97: 200–205. © 2006 Wiley Periodicals, Inc.
Enhanced high copy number plasmid maintenance and heterologous protein production in an Escherichia coli biofilm
Authors: O'Connell Heather A. , Niu Chen , Gilbert Eric S. 
Published: October 2006

AbstractEscherichia coli has been widely used for heterologous protein production (HPP). To determine whether a biofilm environment could benefit E. coli HPP using high copy number plasmids, we compared plasmid maintenance and HPP by E. coli ATCC 33456 containing plasmid pEGFP (a pUC family vector) cultivated in biofilms and in suspended culture. Cells were grown with or without antibiotic selective pressure in flow cells or chemostats for up to 6 days. In biofilms, antibiotic selective pressure increased the plasmid copy number (PCN), but by 144 h, biofilms grown in antibiotic‐free media had comparable plasmid concentrations. In the chemostat, the PCN declined steadily, although 100 ppm ampicillin in the medium slowed the rate of plasmid loss. Production of green fluorescent protein (GFP), a representative heterologous protein, was quantified by flow cytometry. In biofilms, at ampicillin concentrations ≥33 ppm, strongly fluorescent cells comprised more than half of the population by 48 h. In the chemostat, more than 50% of the population was non‐fluorescent by 48 h in media containing 100 ppm ampicillin, and strongly fluorescent cells were <10% of the population. Biofilm structure was determined by confocal microscopy. Maximum biofilm thickness ranged from 30 to 45 microns, with no significant changes in biofilm structure after 48 h. Plasmid multimer percentages were similar to inocula for cells cultivated in either biofilms or the chemostat. The results indicate that the biofilm environment enhanced both plasmid maintenance and cellular GFP concentrations, and that low levels of antibiotic increased the beneficial effect. Biotechnol. Bioeng. 2007;97: 439–446. © 2006 Wiley Periodicals, Inc.
Predicting sentinel node status in AJCC stage I/II primary cutaneous melanoma
Authors: Kruper Laura L. , Spitz Francis R. , Czerniecki Brian J. , Fraker Douglas L. , Blackwood‐Chirchir Anne , Ming Michael E. , Elder David E. , Elenitsas Rosalie , Guerry DuPont , Gimotty Phyllis A. 
Published: October 2006

AbstractBACKGROUND.Sentinel lymph node (SLN) status is an important prognostic factor for survival for patients with primary cutaneous melanoma. To address the issue of selecting patients at high and low risk for a positive SLN, prognostic factors were sought that predict SLN involvement by examining characteristics of both the primary tumor and the patient within the context of a biological model of melanoma progression.METHODS.The study included 682 patients with primary vertical growth phase (VGP) melanoma and no clinical evidence of metastatic disease who underwent SLN biopsy (1995–2003). Logistic regression and classification tree analyses were used to investigate the association between SLN positivity and Breslow thickness, Clark level, tumor infiltrating lymphocytes (TIL), ulceration, mitotic rate (MR), lesion site, gender, and age.RESULTS.In all, 88 of the 682 patients had ≥1 positive SLN (12.9%). In the multivariate analysis, MR, TIL, and thickness were found to be independent prognostic factors for SLN positivity. In the classification tree, four different risk groups were defined, ranging from minimal risk (2.1%) to high risk (40.4%). In lesions ≤2.0 mm, MR was important in risk‐stratifying patients, and in lesions >2.0 mm TIL was important.CONCLUSIONS.By incorporating biologically based variables such as VGP, TIL, and MR along with thickness into a prognostic model, both patients at high risk and minimal risk for SLN positivity can be identified. If validated, this model can be used in patient management and trial design to select patients to undergo or be spared SLN biopsy. Cancer 2006. © 2006 American Cancer Society.
Fabrication and characterization of PLLA–chitosan hybrid scaffolds with improved cell compatibility
Authors: Jiao Yanpeng , Liu Zonghua , Zhou Changren 
Published: October 2006

AbstractTo combine the individual advantages of synthetic and natural polymers, poly(L‐lactic acid) (PLLA)–chitosan hybrid scaffolds were fabricated. PLLA sponges were prepared by particulate‐leaching, and then PLLA–chitosan hybrid scaffolds were obtained by dipping the PLLA sponges in chitosan solution and subsequently freeze–drying. Physicochemical properties of the scaffolds were characterized by scanning electron microscopy (SEM), water uptake test, and mechanical strength measurement. Moreover, cell adhesion, cell proliferation, and cell viability on the scaffolds were evaluated through osteoblast‐like cell culture. The experimental results indicated that, PLLA sponges exhibited macroporous structure and the interconnected microporous structure of chitosan was formed within the macropores of PLLA sponges. The incorporation of chitosan reinforced PLLA sponges in dependence on chitosan content. The hybrid scaffolds had higher water uptake ability compared with PLLA sponges. Particularly, the hybrid scaffolds exhibited excellent cell attachment efficiency, cell proliferation, and cell viability. This study suggests that the hybrid scaffolds obtain good mechanical strength from PLLA and excellent cell compatibility from chitosan. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Changes in desmoglein 1 expression and subcellular localization in cultured keratinocytes subjected to anti‐desmoglein 1 pemphigus autoimmunity
Authors: Cirillo Nicola , Gombos Fernando , Lanza Alessandro 
Published: October 2006

AbstractThe complexity of pemphigus acantholysis together with the weak expression of desmoglein 1 (Dsg1) in cultured keratinocytes have made the study on the pathogenic action of anti‐Dsg1 antibodies quite difficult. The pathophysiology of the acantholytic phenomenon could depend on the reduction of Dsg1 adhesion function occurring after its massive internalization or decrease of its synthesis. Here, we have investigated this hypothesis by using sera of patients having antibodies against Dsg1 or monoclonal anti‐Dsg1 antibodies to simulate pemphigus autoimmunity in Dsg1‐rich keratinocytes. Similar to pemphigus foliaceus (PF) and vulgaris (PV) sera, monoclonal anti‐Dsg1 antibodies induced transient internalization of Dsg1 and reduced the adhesion strength among keratinocytes. However, binding of IgG to Dsg1 did not determine its early depletion from the adhesion complexes but reduced the amount of Dsg1 found in the Triton X‐100 soluble pool of proteins. Taken together, our results represent the first demonstration that anti‐Dsg1 antibodies induce similar alterations on the subcellular distribution of Dsg1 irrespective of the disease where they come from. Furthermore, the present study provides insight into the mechanisms underlying epithelial blistering observed in the skin type of pemphigus. J. Cell. Physiol. 210: 411–416, 2007. © 2006 Wiley‐Liss, Inc.
Complete graphs with no rainbow path
Authors: Thomason Andrew , Wagner Peter 
Published: October 2006

AbstractMotivated by questions in Ramsey theory, we consider colorings of the edges of the complete graph Kn that contain no rainbow path Pt+1 of length t. If fewer than t colors are used then certainly there is no rainbow Pt+1. We show that, if at least t colors are used, then very few colorings are possible if t ≤ 5 and these can be described precisely, whereas the situation for t ≥ 6 is qualitatively different. © 2006 Wiley Periodicals, Inc. J Graph Theory 54: 261–266, 2007
Identification of certain chemical agents in complex organic solutions by gas chromatography/tandem mass spectrometry
Authors: Mei‐ling Lei , Hai‐ling Xi , Da‐nian Xu , Zhi‐sheng Chen 
Published: October 2006

AbstractAnalytical methods that are used for the detection and identification of chemicals related to the Chemical Weapons Convention in complex organic solutions were developed. A matrix modified by the addition of complex diesel oil background compounds and interferences was used for the development of a gas chromatography‐mass spectrometry or gas chromatography‐tandem mass spectrometry (GC‐MS or GC‐MS/MS) method for unambiguous identification of the scheduled chemicals. Co‐elution of diethyl N,N‐dimethylphosphoramidate and ethyl N,N‐dimethylphosphoramidocyanidate, which are not separated by GC, was identified by GC‐MS. Although GC‐MS can identify the compounds, GC‐MS/MS identification has greater accuracy and sensitivity in the case of complex matrixes. Four scheduled chemicals were accurately and selectively identified against numerous interfering substances by GC‐MS/MS. The fragmentation chemistry of these compounds using MS/MS analysis was investigated. Copyright © 2006 John Wiley & Sons, Ltd.