bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regional and species specific bioaccumulation of major and trace elements in Arctic seabirds
Authors: Borgå Katrine , Campbell Linda , Gabrielsen Geir W. , Norstrom Ross J. , Muir Derek C.G. , Fisk Aaron T. 
Published: October 2006

Abstract
Twenty-five essential and nonessential elements were analyzed in Arctic seabirds to study the influence of phylogeny, tissue, Arctic region, and diet on avian element accumulation and to identify co-occurrence among metals. Muscle and liver concentrations were positively correlated, generally being higher in liver than in muscle, and generally did not differ by sex. Zinc showed the highest absolute concentrations in all samples (mean, 11.2–26.7 μg/g in muscle, depending on species and area), followed by copper (5.2–7.5 μg/g), arsenic (0.5–5.4 μg/g), selenium (1.0–5.8 μg/g), rubidium (1.4–2.2 μg/g), and cadmium (0.04–1.2 μg/g). Mercury levels ranged from 0.05 to 0.8 μg/g in muscle. The concentrations varied among species (dovekie [Alle alle], black guillemot [Cepphus grylle], thick-billed murre [Uria lomvia], black-legged kittiwake [Rissa tridactyla], northern fulmar [Fulmaris glacialis], ivory gull [Pagophila eburnean], Thayer's gull [Larus thayeri], and glaucous gull [Larus hyperboreus]), and between the northern Baffin Bay (Canada) and the Barents Sea, depending on the element. Whereas some elements (e.g., mercury and zinc) increased in absolute and standardized concentrations with trophic level in the northern Baffin Bay, most elements showed no relationship with trophic level or other dietary descriptors. In absolute concentrations, nonessential elements differed between regions, whereas essential elements differed among species but not within a species across the two regions. Standardized concentrations (element pattern) of both essential elements and nonessential elements generally did not differ between regions but was highly species specific and, thus, determined by the phylogenetic element regulation capacity. The usefulness of multivariate ordination in element wildlife studies is illustrated, which provides additional insight regarding element co-occurrence in wildlife, allows inclusion of species with low sample number, and reduces the possibility of type II errors created by low sample size.
Assessment of stress-related gene expression in the heavy metal-exposed nematodeCaenorhabditis elegans: A potential biomarker for metal-induced toxicity monitoring and environmental risk assessment
Authors: Roh Ji-Yeon , Lee Junho , Choi Jinhee 
Published: October 2006

AbstractThe toxicity of cadmium, lead, chromium, and arsenite on Caenorhabditis elegans was investigated to identify sensitive biomarkers for environmental monitoring and risk assessment. Effects of these metals on stress-related gene expression, growth, reproduction, and mortality of C. elegans were investigated under laboratory conditions. The possibility of using C. elegans as a biosensor for environmental toxicity monitoring was also tested using a green fluorescent protein transgenic nematode. The 24-h median lethal concentrations of cadmium, lead, chromium, and arsenite in C. elegans were 846, 34, 115, and 92 mg/L, respectively. Cadmium exposure led to an increase in the expression of most of the genes tested. The degree of increase was more than threefold compared to control in heat shock protein 16.2, heat shock protein 70, metallothionein 2, cytochrome P450 family protein 35A2, glutathione-S-transferase 4, superoxide dismutase 1, catalase 2, C. elegans p53-like protein 1, and apoptosis enhancer 1 genes. The lead-, chromium-, and arsenite-exposed nematode, on the other hand, showed little change in gene expression. Alterations in growth and reproduction were observed in cadmium- and chromium-exposed worms. To consider a transgenic nematode as a biosensor for toxicity monitoring, the responses of stress-related gene promoters need to be tested with a variety of metals. The overall results suggest that cadmium exhibits a high level of tolerance compared to the other metals tested. Use of the responses of stress-related gene expression therefore has considerable potential as a sensitive biomarker for the diagnosis of cadmium contamination, and C. elegans seems to be a good biological model for this approach.
Desorption resistance of polycyclic aromatic hydrocarbons and duration of exposure
Authors: Chai Yunzhou , Kochetkov Alexander , Reible Danny D. 
Published: October 2006

AbstractThe desorption-resistant fraction of laboratory-spiked phenanthrene in two Louisiana (USA) sediments was not observed to be significantly different, but the two sediments exhibited different condensed-phase organic carbon contents, as defined operationally by the organic carbon remaining after combustion of the sediment at 375°C. Only 3% of the original saturated phenanthrene in the sediments was not readily removed by exposure to a nonpolar polymeric resin and sorbent XAD-2. Allowing the laboratory-spiked contaminants to age for periods of up to three years yielded little difference in the desorption-resistant characteristics of the sediments. Field-contaminated sediments from Utica Harbor (Utica, NY, USA) and Rouge River (Detroit, MI, USA) that had a lengthy (decades to a century) period of contamination, however, exhibited significantly different desorption-resistant contaminant fractions, consistent with the fractions of condensed-phase organic carbon in the sediments. Measurements of the fraction that could be rapidly desorbed using the XAD-2 sorbent also accounted for essentially all desorption to pore water and, thus, provided a good prediction of effective bulk partition coefficients. It was concluded that the condensed-phase organic carbon was a good indicator of the potential for desorption resistance in field-contaminated sediments and that the rapidly desorbing fraction provided a quantitative indicator of its significance.
Development and application of oxygen production rate assessment to uptake of fluorinated organics byLemna minor
Authors: Reinhold Dawn Marie , Saunders F. Michael 
Published: October 2006

AbstractThe effects of contaminant concentration on contaminant removal by Lemna minor were examined under elevated plant densities typical of full surface coverage. Uptake of 3-fluorophenol and 3-trifluoromethylphenol by L. minor was determined at concentrations from 10 to 1,750 μM. Because standardized toxicity tests typically do not measure plant activity of L. minor at high plant densities, an oxygen production rate (OP) assessment was developed with consideration of experimental parameters that may inhibit OP by L. minor, including concentrations of carbonate and phosphate buffer in the media, time of assessment, and mass of L. minor. The OP by L. minor was inhibited by increasing media pH and mass of L. minor. The developed assessment used 0.5 g of L. minor per 60 ml of modified Standard Methods medium. A total of 30 h was needed to determine toxicity of fluorinated phenols, with an exposure period of 24 h, an incubation time of 6 h, and negligible analysis time. At concentrations from 10 to 1,750 μM, 3-trifluoromethylphenol exhibited a sigmoidal toxicity response. However, 3-fluorophenol was neither toxic nor inhibitory at the experimental concentrations tested. Substantial decreases in uptake rate constants were observed for increasing concentrations of both contaminants, indicating that concentration may be a more important indicator of uptake by L. minor compared with decreasing plant activity because of toxicity.
Photoactivated polycyclic aromatic hydrocarbon toxicity in medaka (Oryzias latipes) embryos: Relevance to environmental risk in contaminated sites
Authors: Diamond Stephen A. , Mount David R. , Mattson Vincent R. , Heinis Larry J. , Highland Terry L. , Adams Andy D. , Simcik Matthew F. 
Published: October 2006

AbstractThe hazard for photoactivated toxicity of polycyclic aromatic hydrocarbons (PAHs) has been clearly demonstrated; however, to our knowledge, the risk in contaminated systems has not been characterized. To address this question, a median lethal dose (LD50) for fluoranthene photoactivated toxicity in medaka (Oryzias latipes) embryos was determined experimentally and then compared with ultraviolet-A (UV-A; 320–400 nm) radiation exposures in a PAH-contaminated field site. The dose metric, J/cm2/μg fluoranthene/g egg wet weight, provided the means to estimate risk as the depth where the LD50 level would be exceeded at realistic field PAH concentrations, based on estimates of UV-A exposure. The estimates were made using 30 years of solar radiation data for Duluth (MN, USA) and measurements of water-column UV-A transmittance in a PAH-contaminated field site. Medaka embryo failure was strongly related to tissue PAH concentration and UV-A exposure. The LD50 was estimated to be 12.64 J/cm2/μg fluoranthene/g egg wet weight; the 95% confidence interval was 8.46 to 19.7 J/cm2/μg fluoranthene/g egg wet weight. Embryo failures were characterized by undifferentiated cell proliferation that occurred very early in development. No partial effects or embryo/larval malformations were observed. Estimates of the depth at which the LD50 would be exceeded in the contaminated field site ranged from 10.7 cm (clear-sky conditions and lowest attenuation) to 0.0 cm (cloudy conditions and highest attenuation). Similar calculations were done using water-column attenuation estimates from 12 sites across the Great Lakes (USA). For these, the depths at which the LD50 would be exceeded ranged from 0.00 to 271.6 cm under the conditions described above. These results suggest that PAH phototoxicity may be a risk factor in specific contaminated sites, and they provide a framework for assessing that risk.
Impacts of aircraft deicer and anti-icer runoff on receiving waters from Dallas/Fort worth International Airport, Texas, USA
Authors: Corsi Steven R. , Harwell Glenn R. , Geis Steven W. , Bergman Daniel 
Published: October 2006

AbstractFrom October 2002 to April 2004, data were collected from Dallas/Fort Worth (DFW) International Airport (TX, USA) outfalls and receiving waters (Trigg Lake and Big Bear Creek) to document the magnitude and potential effects of aircraft deicer and anti-icer fluid (ADAF) runoff on water quality. Glycol concentrations at outfalls ranged from less than 18 to 23,800 mg/L, whereas concentrations in Big Bear Creek were less because of dilution, dispersion, and degradation, ranging from less than 18 to 230 mg/L. Annual loading results indicate that 10 and 35% of what was applied to aircraft was discharged to Big Bear Creek in 2003 and 2004, respectively. Glycol that entered Trigg Lake was diluted and degraded before reaching the lake outlet. Dissolved oxygen (DO) concentrations at airport outfalls sometimes were low (&lt;2.0 mg/L) but typical of what was measured in an urban reference stream. In comparison, the DO concentration at Trigg Lake monitoring sites was consistently greater than 5.5 mg/L during the monitoring period, probably because of the installation of aerators in the lake by DFW personnel. The DO concentration in Big Bear Creek was very similar at sites upstream and downstream of airport influence (&gt;5.0 mg/L). Results of toxicity tests indicate that effects on Ceriodaphnia dubia, Pimephales promelas, and Selanastrum capricornutum are influenced by type IV ADAF (anti-icer), not just type I ADAF (deicer) as is more commonly assumed.
Multiphase biokinetic modeling of cadmium accumulation inDaphnia magnafrom dietary and aqueous sources
Authors: Guan Rui , Wang Wen-Xiong 
Published: October 2006

AbstractWe investigated the Cd accumulation dynamics in a freshwater cladoceran, Daphnia magna, and validated the biokinetic accumulation model under nonsteady-state conditions. All biokinetic parameters were monitored for the animals from birth to the adult stage. During the whole exposure period, two factors were observed to play critical roles in affecting Cd bioaccumulation. One was the Cd partitioning between the dissolved and dietary phases. Although the total Cd loads in the exposure media were kept constant, the increasing Cd partitioning from the water to the food promoted Cd bioaccumulation by approximately twofold. The other factor was the growth rate constant, which was comparable with the Cd efflux rate constant in daphnids and significantly influenced Cd accumulation because of its variation in different developmental stages. A multiphase modeling approach was used to simulate such a nonsteady-state process. This approach was viewed as a success, because the model simulations clearly aided in the interpretation of the experimentally observed temporal Cd accumulation in daphnids. Proper application of the kinetic bioaccumulation model undoubtedly will help us to understand time-dependent responses under the nonsteady state, which may be caused by episodic exposure or seasonal fluctuations in food/particle availability.
Metallodielectric Hollow Shells: Optical and Catalytic Properties
Authors: Pastoriza‐Santos Isabel , Pérez‐Juste Jorge , Carregal‐Romero Susana , Hervés Pablo , Liz‐Marzán Luis M. 
Published: October 2006

AbstractMetallodielectric composites with tunable optical properties were prepared by layer‐by‐layer assembly of gold nanorods on polystyrene (PS) spheres and subsequent deposition of SiO2 or TiO2 encapsulating shells through a sol–gel process. The optical properties of the core‐shells were tailored in the visible and the near‐infrared region through the gold nanorod aspect ratio and the gold nanoparticle density. Removal of the PS core by dissolution in an appropriate solvent, such as THF, yielded metallodielectric hollow shells with optical properties identical to those of the original composites. The presence of gold and the porosity of the SiO2 or TiO2 shells, suitable to allow diffusion of reactants and products, make these materials of interest as catalysts, as demonstrated by the reduction of potassium hexacyanoferrate(III) with NaBH4.
Biogas plasticization coupled anaerobic digestion: Batch test results
Authors: Schimel Keith A. 
Published: October 2006

AbstractBiogas has unique properties for improving the biodegradability of biomass solids during anaerobic digestion (AD). This report presents batch test results of the first investigation into utilizing biogas plasticization to “condition” organic polymers during active digestion of waste activated sludge (WAS). Preliminary design calculations based on polymer diffusion rate limitation are presented. Analysis of the 20°C batch test data determined the first order (k1) COD conversion coefficient to be 0.167 day−1 with a maximum COD utilization rate of 11.25 g L−1 day−1. Comparison of these batch test results to typical conventional AD performance parameters showed orders of magnitude improvement. These results show that biogas plasticization during active AD could greatly improve renewable energy yields from biomass waste materials such as MSW RDF, STP sludges, food wastes, animal manure, green wastes, and agricultural crop residuals. Biotechnol. Bioeng. 2007;97: 297–307. © 2006 Wiley Periodicals, Inc.
A gas‐inducible expression system in HEK.EBNA cells applied to controlled proliferation studies by expression of p27Kip1
Authors: Werner Nicola Susann , Weber Wilfried , Fussenegger Martin , Geisse Sabine 
Published: October 2006

AbstractWe describe an efficient inducible gene expression system in HEK.EBNA cells, a well‐established cell system for the rapid transient expression of research‐tool proteins. The transgene control system of choice is the novel acetaldehyde‐inducible regulation (AIR) technology, which has been shown to modulate transgene levels following exposure of cells to acetaldehyde. For application in HEK.EBNA cells, AlcR transactivator plasmids were constructed and co‐expressed with the secreted alkaline phosphatase (SEAP) gene under the control of a chimeric mammalian promoter (PAIR) for acetaldehyde‐regulated expression. Several highly inducible transactivator cell lines were established. Adjustable transgene induction by gaseous acetaldehyde led to high induction levels and tight repression in transient expression trials and in stably transfected HEK.EBNA cell lines. Thus, the AIR technology can be used for inducible expression of any desired recombinant protein in HEK.EBNA cells. A possible application for inducible gene expression is a controlled proliferation strategy. Clonal HEK.EBNA cell lines, expressing the fungal transactivator protein AlcR, were engineered for gas‐adjustable expression of the cell‐cycle regulator p27Kip1. We show that expression of p27Kip1 via transient or stable transfection led to a G1‐phase specific growth arrest of HEK.EBNA cells. Furthermore, production pools engineered for gas‐adjustable expression of p27Kip1 and constitutive expression of SEAP showed enhanced productive capacity. Biotechnol. Bioeng. 2007;96:1155–1166. © 2006 Wiley Periodicals, Inc.
Investigation of metabolic objectives in cultured hepatocytes
Authors: Uygun Korkut , Matthew Howard W.T. , Huang Yinlun 
Published: October 2006

AbstractUsing optimization based methods to predict fluxes in metabolic flux balance models has been a successful approach for some microorganisms, enabling construction of in silico models and even inference of some regulatory motifs. However, this success has not been translated to mammalian cells. The lack of knowledge about metabolic objectives in mammalian cells is a major obstacle that prevents utilization of various metabolic engineering tools and methods for tissue engineering and biomedical purposes. In this work, we investigate and identify possible metabolic objectives for hepatocytes cultured in vitro. To achieve this goal, we present a special data‐mining procedure for identifying metabolic objective functions in mammalian cells. This multi‐level optimization based algorithm enables identifying the major fluxes in the metabolic objective from MFA data in the absence of information about critical active constraints of the system. Further, once the objective is determined, active flux constraints can also be identified and analyzed. This information can be potentially used in a predictive manner to improve cell culture results or clinical metabolic outcomes. As a result of the application of this method, it was found that in vitro cultured hepatocytes maximize oxygen uptake, coupling of urea and TCA cycles, and synthesis of serine and urea. Selection of these fluxes as the metabolic objective enables accurate prediction of the flux distribution in the system given a limited amount of flux data; thus presenting a workable in silico model for cultured hepatocytes. It is observed that an overall homeostasis picture is also emergent in the findings. Biotechnol. Bioeng. 2007;97: 622–637. © 2006 Wiley Periodicals, Inc.
Late adverse effects of short-course preoperative radiotherapy in rectal cancer
Authors: Pollack J , Holm T , Cedermark B , Altman D , Holmström B , Glimelius B , Mellgren A 
Published: October 2006

Abstract

Background
Preoperative radiotherapy improves local control and survival in rectal cancer, but there are few reports on long-term morbidity. The aims of this study were to compare long-term morbidity and quality of life in patients undergoing rectal cancer surgery with or without preoperative radiotherapy.

Methods
A total of 252 patients, randomized within the two Stockholm trials on preoperative radiotherapy in rectal cancer, were alive at a mean of 15 years after surgery. Some 139 of these patients were available for follow-up by questionnaires and clinical examination. Questionnaires regarding medical history and quality of life were completed by all patients. All patients had a clinical examination, and those without a stoma underwent rigid sigmoidoscopy.

Results
Overall, patients who had preoperative radiotherapy experienced significantly more late complications than those who did not (69 versus 43 per cent; P = 0·002). This morbidity consisted mainly of cardiovascular disease (35 versus 19 per cent; P = 0·032), faecal incontinence (12 of 21 versus 11 of 42 patients having anterior resection; P = 0·013) and urinary incontinence (45 versus 27 per cent; P = 0·023). No significant differences between groups were found for hip or pelvic fractures, small bowel obstruction or global quality of life.

Conclusion
Preoperative short-course, high-dose radiotherapy in patients with rectal cancer increases the risk of anal and urinary dysfunction, and may lead to increased cardiovascular morbidity, at long-term follow-up.
Characterization of reflux events after fundoplication using combined impedance–pH recording
Authors: Roman S , Poncet G , Serraj I , Zerbib F , Boulez J , Mion F 
Published: October 2006

Abstract

Background
Laparoscopic fundoplication effectively controls symptoms of gastro-oesophageal reflux disease (GORD) and decreases acid reflux, but its impact on non-acid reflux is not known. The aim of the study was to characterize reflux events after fundoplication using oesophageal combined multichannel intraluminal impedance (MII)–pH monitoring, to demonstrate its efficacy on acid as well as non-acid reflux events.

Methods
Thirty-six patients in whom ambulatory MII–pH recording was performed after laparoscopic fundoplication were reviewed retrospectively. There were 23 symptomatic and 13 asymptomatic patients, whose results were compared with those of 72 healthy volunteers.

Results
Oesophageal acid exposure was low in all but one operated patient, and there was no difference between those with and without symptoms. The median number of reflux events over 24 h was lower after fundoplication (11 in operated patients compared with 44 in healthy volunteers; P &lt; 0·001). Almost all reflux events were non-acid after surgery whereas acid reflux episodes were predominant in healthy volunteers. Proximal reflux events were less common in operated patients. Non-acid reflux events were significantly associated with symptoms after surgery in some patients.

Conclusion
Fundoplication restores a competent barrier for all types of reflux. Reflux events are mostly non-acid after surgery, and such events may be positively correlated with symptoms.
Tissue oxygen saturation, measured by near-infrared spectroscopy, and its relationship to surgical-site infections
Authors: Ives C L , Harrison D K , Stansby G S 
Published: October 2006

Abstract

Background
Surgical-site infections (SSIs) are common after major abdominal and groin bypass surgery. Tissue oxygen tension has been shown to predict these infections accurately. This study assessed whether a non-invasive measurement of tissue oxygenation, tissue oxygen saturation as measured by spectrophotometry, was as accurate.

Methods
Fifty-nine patients having major abdominal or groin bypass surgery had tissue oxygen saturation measured by near-infrared spectrophotometry at the incision site and in the arm before operation, and at 12, 24 and 48 h after surgery. Masked outcome assessments for SSI were made at 7 and 30 days after operation.

Results
In this retrospective analysis, 17 patients (29 per cent) developed an SSI. At 12 h after operation there was a significant difference in tissue oxygen saturation at the surgical site between patients who developed an SSI and those who did not (mean(s.d.) 43·4(18·1) versus 55·8(22·0) per cent; P = 0·032). These oxygen saturation readings were found to be more specific and sensitive in predicting SSIs than the National Nosocomial Infection Surveillance system.

Discussion
There is a difference in postoperative surgical-site oxygen saturation between patients who subsequently develop SSIs and those who do not. Prediction of SSIs provides opportunities for intervention and prevention.