bluuebunny/crossref_metadata_2025_split huggingface dataset:
DNA methylation alterations in response to pesticide exposure in vitro
Authors: Zhang Xiao , Wallace Andrew D. , Du Pan , Kibbe Warren A. , Jafari Nadereh , Xie Hehuang , Lin Simon , Baccarelli Andrea , Soares Marcelo Bento , Hou Lifang 
Published: July 2012

AbstractAlthough pesticides are subject to extensive carcinogenicity testing before regulatory approval, pesticide exposure has repeatedly been associated with various cancers. This suggests that pesticides may cause cancer via nonmutagenicity mechanisms. The present study provides evidence to support the hypothesis that pesticide‐induced cancer may be mediated in part by epigenetic mechanisms. We examined whether exposure to seven commonly used pesticides (i.e., fonofos, parathion, terbufos, chlorpyrifos, diazinon, malathion, and phorate) induces DNA methylation alterations in vitro. We conducted genome‐wide DNA methylation analyses on DNA samples obtained from the human hematopoietic K562 cell line exposed to ethanol (control) and several organophosphate pesticides (OPs) using the Illumina Infinium HumanMethylation27 BeadChip. Bayesian‐adjusted t‐tests were used to identify differentially methylated gene promoter CpG sites. In this report, we present our results on three pesticides (fonofos, parathion, and terbufos) that clustered together based on principle component analysis and hierarchical clustering. These three pesticides induced similar methylation changes in the promoter regions of 712 genes, while also exhibiting their own OP‐specific methylation alterations. Functional analysis of methylation changes specific to each OP, or common to all three OPs, revealed that differential methylation was associated with numerous genes that are involved in carcinogenesis‐related processes. Our results provide experimental evidence that pesticides may modify gene promoter DNA methylation levels, suggesting that epigenetic mechanisms may contribute to pesticide‐induced carcinogenesis. Further studies in other cell types and human samples are required, as well as determining the impact of these methylation changes on gene expression. Environ. Mol. Mutagen. 2012. © 2012 Wiley Periodicals, Inc.
Association of endocrine-disrupting chemicals with total organic carbon in riverine water and suspended particulate matter from the Pearl River, China
Authors: Gong Jian , Ran Yong , Chen Diyun , Yang Yu , Zeng Eddy Y. 
Published: July 2012

Abstract
The distribution of endocrine-disrupting chemicals (EDCs) and its relationship with dissolved and particulate organic carbon (DOC and POC) was investigated in selected rivers of the Pearl River Delta, South China. The aqueous concentrations (average; ng/L) and particulate concentrations (average; ng/g, dry wt) for 4-tert-octylphenol (OP), 4-nonylphenol (NP), bisphenol A (BPA), and estrone (E1) were in the ranges of not detectable to 153 (31.8), 276 to 2,457 (1,178), 8.4 to 628 (161), and less than 1.5 to 11.5 (3.2), respectively, and 4.4 to 402 (98.1), 342 to 12,053 (4,922), 12.3 to 758 (128), and not detectable to 14.4, respectively. The highly significant correlation of EDCs with DOC and POC, and the similar regression slopes, implied the critical importance of DOC and POC on the distribution, transport, and fate of EDCs in the aquatic environment. The in situ particle–water partition coefficients (log KOC) for OP (4.89 ± 0.41), NP (5.05 ± 0.33), and BPA (4.34 ± 0.50) were close to those reported by other field studies, but one to two orders of magnitude higher than those predicted with n-octanol–water partition coefficient (KOW). The higher KOC values were attributed to the combined effects of low EDC concentrations, nonlinear sorption, and heterogeneity of POC and DOC. Moreover, a regression between in-situ KOC and KOW for phenolic xenoestrogens was observed (log KOC = 0.625 × log KOW + 2.28, r2 = 0.99), suggesting that hydrophobicity contributed predominantly to the overall sorption of OP, NP, and BPA. Environ. Toxicol. Chem. 2012; 31: 2456–2464. © 2012 SETAC
How do stream organisms respond to, and influence, the concentration of titanium dioxide nanoparticles? A mesocosm study with algae and herbivores
Authors: Kulacki Konrad J. , Cardinale Bradley J. , Keller Arturo A. , Bier Raven , Dickson Helen 
Published: July 2012

Abstract
The biologically active properties of many nanomaterials, coupled with their rapidly expanding production and use, has generated concern that certain types of nanoparticles could have unintended impacts when released into natural ecosystems. In the present study, the authors report the results of an experiment in which they grew three common species of stream algae as monocultures and together as polycultures in the biofilms of stream mesocosms that were exposed to 0, 0.1, or 1.0 ppm nanoparticle titanium dioxide (nTiO2). The nTiO2 did not alter the growth trajectory of any algal biofilm over 10+ generations. However, Ti accrual in biofilms not only differed among the algal species but was also higher in polycultures than in the average monoculture. Variation in accrual among species compositions was readily predicted by differences in the total biomass achieved by the different biofilms. When biofilms were fed to the herbivorous snail Physa acuta at the end of the experiment, initial concentrations of nTiO2 did not alter short-term rates of herbivory. However, because of differences in palatability among the algae, biofilm composition influenced the amount of nTiO2 that accumulated in the herbivore tissue. The results have important implications for understanding how efficiently nTiO2 is removed from surface waters and the potential transfer of nanomaterials to higher trophic levels. Environ. Toxicol. Chem. 2012; 31: 2414–2422. © 2012 SETAC
Analysis of regional recurrence after negative sentinel lymph node biopsy for head and neck melanoma
Authors: McDonald Kelly , Page Andrew J. , Jordan Sumanas W. , Chu Carrie , Hestley Andrea , Delman Keith A. , Murray Douglas R. , Carlson Grant W. 
Published: July 2012

AbstractBackgroundThe head and neck have a rich lymphatic drainage and complex anatomy, which complicate sentinel lymph node (SLN) biopsy for melanoma. The incidence of regional recurrence after a negative SLN biopsy has been shown to be higher than that at other sites. Compounding factors in this scenario were analyzed to determine their impact on both SLN status and survival.MethodsA retrospective review of a prospective database of 315 patients who underwent SLN biopsy for head and neck melanoma from 1994 to 2009 was performed. A false‐negative SLN biopsy was defined as a regional recurrence in a previously mapped nodal basin.ResultsIn all, 267 patients (84.8%) were SLN negative (SLN−) and 48 patients (15.2%) were SLN positive (SLN+). The false‐negative SLN biopsy occurred in 17 patients (6.4%). The mean follow‐up was 37.6 months (3–152 months). The false‐negative SLN and SLN+ patients were similar with respect to patient age and sex and primary melanoma tumor thickness and ulceration. The site of the primary melanoma and the lymphatic drainage patterns did not influence the false‐negative biopsy rate. The mean survival was SLN− 119.3 months (95% confidence interval [CI], 106.1–132.5, p < .001), SLN+ 73.4 months (95% CI, 52.3–94.4), and the false‐negative SLN 70.7 months (95% CI, 54.2–87.1).ConclusionsThe risk of a false‐negative SLN biopsy in head and neck melanoma is independent of primary site and lymphatic drainage pattern. Patients with head and neck melanoma who have a regional recurrence after a negative SLN biopsy do not have a worse survival than that of patients who are initially SLN positive. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
“Mystic” transient recurrent nerve palsy after thyroid surgery
Authors: Altorjay Áron , Rüll Miklós , Paál Balázs , Csáti Géza , Szilágyi Anna 
Published: July 2012

AbstractBackgroundThe mechanism of transient recurrent laryngeal nerve (RLN) palsy remains unclear.MethodsSamples were harvested from the RLN adjacent thyroid capsule and perineural fascia during 223 lobectomies and 89 RLNs from cadavers were used for histologic and immunohistologic evaluation. Intraoperative chromoendoscopic features of the RLN were compared with postoperative ear, nose, and throat examinations.ResultsThose nerves that macroscopically seem to be single‐branched (35 of 89 = 39.3%), microscopically consist of multiple fascicles in most of the cases (23 of 35 = 65.7%), resembling a plexus more than a single cord. Chronic lymphocytic infiltration of the thyroid capsule adjacent to the RLN was present in 29% (65 of 223) of the cases. The perineural fascia showed lymphocytic (18 of 223 = 8.1%) or granulocytic (7 of 223 = 3.1%) infiltration.ConclusionsThe origin of transient RLN palsy is multifactorial: plexus shaped microscopic nerve structure with or without branches, frame‐like adventitial tissue, variable epineurium, inflammatory changes that involve not only the thyroid capsule but the perineural fascia, resultant nerve edema, and diffuse microhemorrhages by injury of fragile capillaries. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
A new angle to mandibular reconstruction: The scapular tip free flap
Authors: Yoo John , Dowthwaite Samuel A. , Fung Kevin , Franklin Jason , Nichols Anthony 
Published: July 2012

AbstractBackgroundThe purpose of this study was to review our experience with the scapular tip free flap for mandibular reconstruction, describe the surgical approach, and highlight specific clinical applications.MethodsA retrospective review of all patients undergoing oromandibular reconstruction using a scapular tip free flap at the London Health Sciences Centre was undertaken. Patient demographics, surgical data, and early outcomes were collated.ResultsTwenty patients were identified. The majority involved mandibular angle and short segment defects (16 of 20). Average length of the segmental defect was 6.2 cm with the longest measuring 8 cm. A single patient required an osteotomy. Six were revision cases. No vein grafts were required. One complete flap failure occurred.ConclusionsThe natural scapular angle makes the scapular tip flap ideal for mandibular angle reconstruction. Short bone segments can be harvested with little donor‐site morbidity. The long pedicle length may obviate vein grafts. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Update and external validation of a head and neck cancer prognostic model
Authors: Datema Frank R. , Ferrier Marciano B. , Vergouwe Yvonne , Moya Ana , Molenaar Jan , Piccirillo Jay F. , Baatenburg de Jong Robert J. 
Published: July 2012

AbstractBackgroundThe purpose of this study was to update and external validation of a prognostic model that is able to predict the survival probability of newly diagnosed patients with head and neck cancer.MethodsOur original prognostic model is based on historical data of 1371 patients with primary head and neck cancer, diagnosed and treated in the Leiden University Medical Center, between 1981 and 1999. The model contains the predictors age, sex, tumor site, TNM‐classification, prior tumors, and comorbidity. We updated the model with follow‐up data until January 2010. The updated model was then externally validated in 598 patients with head and neck cancer from the Siteman Cancer Center/Barnes‐Jewish Hospital, St. Louis, Missouri.ResultsMedian follow‐up was 5.5 years (range, 0–25.5). Only 2.5% of patients were lost to follow‐up. During follow‐up 1099 patients (80.2%) passed away. Discrimination of the updated prognostic model was good, with a C‐index of 0.73 after internal validation. The discrimination was slightly lower in the external validation set (C‐index, 0.69). The predicted 2‐year and 5‐year survival rates correlated satisfactorily with some slight deviations from the perfect calibration line.ConclusionsWe used recent follow‐up information to update the Leiden prognostic model for newly diagnosed patients with head and neck cancer. The model showed acceptably good calibration and discrimination results in internal and external validation procedures. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Pilot, randomized trial of resistance exercise during radiation therapy for head and neck cancer
Authors: Rogers Laura Q. , Anton Philip M. , Fogleman Amanda , Hopkins–Price Patricia , Verhulst Steven , Rao Krishna , Malone James , Robbs Randy , Courneya Kerry S. , Nanavati Parashar , Mansfield Sara , Robbins K. Thomas 
Published: July 2012

AbstractBackgroundThe purpose of this study was to determine the feasibility of a randomized trial of resistance exercise in patients with head and neck cancer receiving radiation.MethodsFifteen patients with head and neck cancer receiving radiation were randomized to resistance exercise (using resistance bands) or control group. Resistance exercise occurred at the radiation therapy site (weeks 1–6) and home (weeks 7–12).ResultsNo serious adverse events occurred related to resistance exercise. Medium to large effect size differences favoring resistance exercise versus control group were noted for perceived fatigue at 6 weeks (smaller increase in fatigue for resistance exercise group; 7.4 vs 15.4, effect size [d] = −0.64), quality of life at 6 weeks (−7.0 vs −14.4, d = 0.52), and chair rise time (seconds) at 6 and 12 weeks (−1.6 vs 0.4, d = −.63 and −1.9 vs 0.1, d = −0.60, respectively).ConclusionsResistance exercise is safe and feasible in patients with head and neck cancer receiving radiation; a definitive trial is warranted. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Demographic diversity, communication and learning behaviour in healthcare groups
Authors: Curşeu Petru Lucian 
Published: July 2012

SUMMARYAn integrative model of group learning was tested in a sample of 40 healthcare groups (434 respondents), and the results show that age diversity reduces the frequency of face‐to‐face communication whereas educational diversity reduces the frequency of virtual communication in healthcare groups. Frequency of communication (both face‐to‐face and virtual), in turn, positively impacts on the emergence of trust and psychological safety, which are essential drivers of learning behaviours in healthcare groups. Additional results show that average educational achievement within groups is conducive for communication frequency (both face‐to‐face and virtual), whereas mean age within groups has a negative association with the use of virtual communication in healthcare groups. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of viscosity variation on natural convection flow of water–alumina nanofluid in an annulus with internal heat generation
Authors: Nasrin Rehena , Alim M.A. , Chamkha Ali J. 
Published: July 2012

AbstractHeat transfer enhancement in a horizontal annulus using the variable viscosity property of an Al2O3–water nanofluid is investigated. Two different viscosity models are used to evaluate heat transfer enhancement in the annulus. The base case uses the Pak and Cho model and the Brinkman model for viscosity which take into account the dependence of this property on temperature and nanoparticle volume fraction. The inner surface of the annulus is heated uniformly by a constant heat flux qw and the outer boundary is kept at a constant temperature Tc. The nanofluid generates heat internally. The governing equations are solved numerically subject to appropriate boundary conditions by a penalty finite‐element method. It is observed that for a fixed Prandtl number Pr = 6.2, Rayleigh number Ra = 104 and solid volume fraction ϕ = 10%, the average Nusselt number is enhanced by diminishing the heat generation parameter, mean diameter of nanoparticles, and diameter of the inner circle. The mean temperature for the fluids (nanofluid and base fluid) corresponding to the above mentioned parameters is plotted as well. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21016
Forced convection and entropy generation inside a channel with a heat‐generating porous block
Authors: Delavar Mojtaba Aghajani , Hedayatpour Mehdi 
Published: July 2012

AbstractThe flow pattern and heat transfer in a composite system containing a porous region has received considerable attention due to its importance in many engineering applications. In this study a thermal lattice Boltzmann model with nine velocities, D2Q9, is employed to investigate the fluid flow, heat transfer, and entropy generation inside a channel with a heat‐generating porous block. The effects of the porous block's length, porosity, and the Reynolds number, overflow pattern, heat transfer, and entropy generation were studied. The mentioned parameters have different effects on heat transfer and conjugate phenomena. By increasing the block length, Reynolds number, and porosity the dimensionless entropy generation will reduce. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21017
Finding the most appropriate precipitation probability distribution for stochastic weather generation and hydrological modelling in Nordic watersheds
Authors: Li Zhi , Brissette Francois , Chen Jie 
Published: July 2012

AbstractSix precipitation probability distributions (exponential, Gamma, Weibull, skewed normal, mixed exponential and hybrid exponential/Pareto distributions) are evaluated on their ability to reproduce the statistics of the original observed time series. Each probability distribution is also indirectly assessed by looking at its ability to reproduce key hydrological variables after being used as inputs to a lumped hydrological model. Data from 24 weather stations and two watersheds (Chute‐du‐Diable and Yamaska watersheds) in the province of Quebec (Canada) were used for this assessment. Various indices or statistics, such as the mean, variance, frequency distribution and extreme values are used to quantify the performance in simulating the precipitation and discharge. Performance in reproducing key statistics of the precipitation time series is well correlated to the number of parameters of the distribution function, and the three‐parameter precipitation models outperform the other models, with the mixed exponential distribution being the best at simulating daily precipitation. The advantage of using more complex precipitation distributions is not as clear‐cut when the simulated time series are used to drive a hydrological model. Although the advantage of using functions with more parameters is not nearly as obvious, the mixed exponential distribution appears nonetheless as the best candidate for hydrological modelling. The implications of choosing a distribution function with respect to hydrological modelling and climate change impact studies are also discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Water balance of the Salado–Juramento river basin (Argentina)
Authors: Virginia Venturini , Krepper Carlos 
Published: July 2012

AbstractA lumped water balance model was used to derive a monthly water storage series in the Salado–Juramento southern basin, for the period 1954–1986. The evapotranspiration term was estimated using the Bouchet's complementary relationship. Different evapotranspiration formulas following the concepts of potential evapotranspiration and wet environmental evapotranspiration were used. The regional average groundwater levels and the specific yield were used to tune Bouchet's equation. The extrapolation of the water storage series to a secular period (1901–2002) was achieved using a synthetic annual discharge series. The water storage was deficient for most of the century, i.e. more than 60 years; nevertheless in the last 30 years, the system recovers half of the water previously lost. The singular spectral analysis showed that a significant low‐frequency signal is present in the water storage and precipitation series. The main cause of water storage variability would be given by precipitation, in spite of the vast anthropogenic changes on the basin. Anthropogenic effects would be reflected in the river discharges, where no significant signal is detected before 1970; however, an annual signal is insinuated after that year. The conclusions of this work could be different if we only looked at the 1954–1986 period. The results of that period suggest that the basin is primarily accumulating water instead of being mainly in deficit. Thus, here we demonstrated the importance of the secular analysis to illustrate the complete basin behaviour. Copyright © 2012 John Wiley & Sons, Ltd.
Surface water–groundwater interaction at restored streams and associated reference reaches
Authors: Daniluk Timothy L. , Lautz Laura K. , Gordon Ryan P. , Endreny Theodore A. 
Published: July 2012

AbstractStream restoration goals include improving habitat and water quality through reconstruction of morphological features found at analogous, pristine stream reaches. Enhancing hyporheic exchange may facilitate achieving these goals. Although hyporheic exchange at restoration sites has been explored in a few previous studies, comparative studies of restored versus reference or control streams are largely absent. We hypothesized that restoration cross‐vanes enhance hyporheic exchange, resulting in biogeochemical alteration of stream water chemistry in the streambed. Two streams restored using cross‐vanes to control erosion and improve habitat were compared with their associated reference reaches, which provided the basis for the restoration design. Thirteen temperature profile rods with vertically stacked sensors were installed at each site for 2 weeks. Heat tracing was used to quantify vertical flux in the streambed from the diurnal temperature fluctuations in the subsurface. Stream water and bed pore waters from mini‐piezometers were analysed for ion and nutrient chemistry. In general, mean vertical flux rates through the streambed were small throughout reference sites (−0.3 to 0.3 m/day) and at most locations at restored sites. Immediately adjacent to cross‐vanes, vertical flux rates were larger (up to 3.5 m/day). Geochemistry of pore waters shows distinct differences in the sources for the reference and restored sites. Strong downwelling zones adjacent to cross‐vanes showed high dissolved oxygen (10.75 mg/l) and geochemistry in the streambed similar to surface water. Reference sites had lower dissolved oxygen in the streambed (0.66–5.14 mg/l), and geochemical patterns suggest a mixture of discharging groundwater and surface water in the hyporheic zone. Restored sites also clearly show sulfate and nitrate reduction occurring in the streambed, which is not observed at the reference sites. The stream restoration sites studied here enhance rapid hyporheic exchange, but upwelling of groundwater has a stronger influence on streambed geochemistry at reference sites. Copyright © 2012 John Wiley & Sons, Ltd.