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51.
Long-range transported atmospheric pollutants in snowpacks accumulated at different altitudes in the Tatra Mountains (Slovakia) 总被引:1,自引:0,他引:1
Arellano L Fernández P Tatosova J Stuchlik E Grimalt JO 《Environmental science & technology》2011,45(21):9268-9275
Persistent organic pollutants (POPs), including polychlorobiphenyls (PCB), endosulfans, hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), polybromodiphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs), were analyzed in snowpack samples collected along an altitudinal gradient (1683-2634 meters above sea level) in the High Tatra Mountains (Slovakia). All analyzed compounds were found at all altitudes, pointing to their global distribution. The presence of PBDEs, particularly BDE 209, in the snowpack samples is especially relevant, as it reflects the air transport capacity of this low volatile, very hydrophobic pollutant to remote mountain regions. The most abundant compounds at all altitudes were PAHs, with mean values ranging from 90 to 300 ngL(-1), 1 order of magnitude higher than concentrations of other compounds. PCBs (sum of PCB 28, 52, 101, 118, 153, 138, and 180) and BDE 209 were the dominant organohalogen pollutants, with concentrations from 550 to 1600 pg L(-1) and from 670 to 2000 pgL(-1), respectively. Low brominated PBDEs, endosulfans, HCHs and HCB were consistently found in all samples at lower concentrations. The concentrations of these compounds correlated positively with altitude (i.e., negatively with temperature), which is consistent with cold-trapping effects. The regression coefficients were positive and statistically significant (p < 0.05) for all compounds except BDE 209, endosulfan sulfate, HCB and α-HCH. Contrariwise, the concentrations of BDE 209 and endosulfan sulfate exhibited a statistically significant positive correlation with total particle amount, which agrees with long-range atmospheric transport associated to aerosols according to the physical-chemical properties of these compounds. Snow specific surface area, which determines the maximum amount of each organic compound that can be sorbed by snow, proved utile for describing the distribution of the more volatile compounds, namely α-HCB and HCB, in the snowpack. 相似文献
52.
Phantipha Charoenthaikij Kamolwan Jangchud Anuvat Jangchud Witoon Prinyawiwatkul Hong Kyoon No Joan M. King 《Journal of food science》2010,75(6):S333-S339
Abstract: Selected physicochemical properties and consumer acceptance of bread prepared from composite flour (wheat:germinated brown rice:germinated glutinous brown rice flours at 60:30:10 ratio) were evaluated during storage for 0, 3, and 5 d, and compared with wheat bread (0 d, control). During storage, color profiles and water activity (from 0.947 to 0.932) of crumbs of composite flour breads slightly changed, but moisture content drastically decreased along with increasing crumb hardness (from 4.16 N to 10.37 N). Higher retrogradation in bread crumb was observed particularly for 5-d stored bread (ΔH = 2.24 J/g) compared to that of the fresh composite bread and the control (ΔH = 0.70 and 0.51 J/g, respectively). Mean (n = 116) overall liking score of the fresh composite flour bread (0 d) was slightly lower than that of the control (7.1 compared with 7.6 based on a 9-point hedonic scale). At least 76% of consumers would purchase the fresh composite flour bread if commercially available. Breads were differentiated by textural (moistness, smoothness, and softness) acceptability with canonical correlation of 0.84 to 0.87. The signal-to-noise ratio values of the 5-d stored breads were lower than the control, due mainly to the non-JAR (not-enough) intensity responses for moistness, smoothness, and softness; the mean drop of liking scores for these attributes ranged from 2.42 to 2.98. Flavor acceptability and overall liking were factors influencing consumers’ purchase intent of composite flour breads based on logistic regression analysis. This study demonstrated feasibility of incorporating up to 40% germinated brown rice flour in a wheat bread formulation. Practical Application: Our previous study revealed that flours from germinated brown rice have better nutritional properties, particularly gamma-aminobutyric acid (GABA), than the nongerminated one. This study demonstrated feasibility of incorporating up to 40% germinated brown rice flour in a wheat bread formulation. In the current U.S. market, this type of bread may be sold as frozen bread that would have a longer shelf life, or may be supplied as a food-service product that would be made-to-order or made fresh daily as currently practiced in some major grocery stores. 相似文献
53.
van Drooge BL Grimalt JO Camarero L Catalan J Stuchlík E Torres García CJ 《Environmental science & technology》2004,38(13):3525-3532
Atmospheric samples from two European high-mountain areas showed similar composition of semivolatile organochlorine compounds (SOC), such as polychlorobiphenyls (PCBs), DDTs, endosulfans, hexachlorobenzene (HCB), and hexachlorocyclohexanes (HCHs). Nearly all compounds were predominantly found in the gas phase and only the less volatile such as some PCBs (e.g., 149, 118, 153, 138, and 180) were found in higher abundance in the particulate phase. HCB, 49-85 pg m(-3), is the dominant SOC. This compound is only found in the gas phase exhibiting uniform concentrations irrespective of season and air mass origin. SOC of present use, like HCHs and endosulfans, were found in higher concentrations in the warm periods, 32-46 and 4-10 pg m(-3) in the gas + particulate phases, respectively, reflecting their seasonal pattern of use in many European countries. PCB and 4,4'-DDE, 39-42 and 4-6 pg m(-3) in the gas + particulate phases, respectively, also showed a seasonal trend despite neither the former nor the precursor of the latter (4,4'-DDT) being manufactured with their use drastically restricted since the 1980s. The seasonal differences are mainly due to a higher occurrence of air masses with strong continental inputs in the warm than in the cold periods. In this respect, samples whose air masses traveled at the high troposphere (backward air mass trajectories >6000 m) have been observed to carry considerably smaller PCB and 4,4'-DDE loads (9.3 +/- 2.8 and 0.4 +/- 0.05 pg m(-3), respectively) than overall average. 相似文献
54.
Joan E. Haysom Omid Jafarieh Hanan Anis Karin Hinzer David Wright 《Progress in Photovoltaics: Research and Applications》2015,23(11):1678-1686
Price declines and volume growth of concentrated photovoltaic (CPV) systems are analysed using the learning curve methodology and compared with other forms of solar electricity generation. Logarithmic regression analysis determines a learning rate of 18% for CPV systems with 90% confidence of that rate being between 14 and 22%, which is higher than the learning rates of other solar generation systems (11% for CSP and 12 to 14% for PV). Current CPV system prices are competitive with PV and CSP, which, when combined with the higher learning rate, indicates that CPV is likely to further improve its marketability. A target price of 1 $/W in 2020 could be achieved with a compound growth rate of 67% for the total deployed volume between 2014 and 2020, which would realize a cumulative deployed volume of 7900 MW. Other projections of deployment volumes from commercial sources are converted using the learning rate into future price scenarios, resulting in predicted prices in the range of 1.1 to 1.3 $/W in 2020. © 2014 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. 相似文献
55.
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57.
The accurate establishment and maintenance of DNA methylation patterns is vital for mammalian development and disruption to these processes causes human disease. Our understanding of DNA methylation mechanisms has been facilitated by mathematical modelling, particularly stochastic simulations. Megabase-scale variation in DNA methylation patterns is observed in development, cancer and ageing and the mechanisms generating these patterns are little understood. However, the computational cost of stochastic simulations prevents them from modelling such large genomic regions. Here, we test the utility of three different mean-field models to predict summary statistics associated with large-scale DNA methylation patterns. By comparison to stochastic simulations, we show that a cluster mean-field model accurately predicts the statistical properties of steady-state DNA methylation patterns, including the mean and variance of methylation levels calculated across a system of CpG sites, as well as the covariance and correlation of methylation levels between neighbouring sites. We also demonstrate that a cluster mean-field model can be used within an approximate Bayesian computation framework to accurately infer model parameters from data. As mean-field models can be solved numerically in a few seconds, our work demonstrates their utility for understanding the processes underpinning large-scale DNA methylation patterns. 相似文献
58.
Marta Vallverdú-Prats Ramon Brugada Mireia Alcalde 《International journal of molecular sciences》2022,23(2)
Arrhythmogenic cardiomyopathy is a heritable heart disease associated with desmosomal mutations, especially premature termination codon (PTC) variants. It is known that PTC triggers the nonsense-mediated decay (NMD) mechanism. It is also accepted that PTC in the last exon escapes NMD; however, the mechanisms involving NMD escaping in 5′-PTC, such as reinitiation of translation, are less known. The main objective of the present study is to evaluate the likelihood that desmosomal genes carrying 5′-PTC will trigger reinitiation. HL1 cell lines were edited by CRISPR/Cas9 to generate isogenic clones carrying 5′-PTC for each of the five desmosomal genes. The genomic context of the ATG in-frame in the 5′ region of desmosomal genes was evaluated by in silico predictions. The expression levels of the edited genes were assessed by Western blot and real-time PCR. Our results indicate that the 5′-PTC in PKP2, DSG2 and DSC2 acts as a null allele with no expression, whereas in the DSP and JUP gene, N-truncated protein is expressed. In concordance with this, the genomic context of the 5′-region of DSP and JUP presents an ATG in-frame with an optimal context for the reinitiation of translation. Thus, 5′-PTC triggers NMD in the PKP2, DSG2* and DSC2 genes, whereas it may escape NMD through the reinitiation of the translation in DSP and JUP genes, with no major effects on ACM-related gene expression. 相似文献
59.
Anna Vallverdú-Queralt José Fernando Rinaldi de Alvarenga Ramon Estruch Rosa M. Lamuela-Raventos 《Food chemistry》2013
Sofrito is a key component of the Mediterranean diet, a diet that is strongly associated with a reduced risk of cardiovascular events. In this study, different Mediterranean sofritos were analysed for their content of polyphenols and carotenoids after a suitable work-up extraction procedure using liquid chromatography/electrospray ionisation-linear ion trap quadrupole-Orbitrap-mass spectrometry (LC/ESI-LTQ-Orbitrap-MS) and liquid chromatography/electrospray ionisation tandem triple quadrupole mass spectrometry (LC/ESI-MS-MS). In this way, 40 polyphenols (simple phenolic and hydroxycinnamoylquinic acids, and flavone, flavonol and dihydrochalcone derivatives) were identified with very good mass accuracy (<2 mDa), and confirmed by accurate mass measurements in MS and MS2 modes. The high-resolution MS analyses revealed the presence of polyphenols never previously reported in Mediterranean sofrito. The quantification levels of phenolic and carotenoid compounds led to the distinction of features among different Mediterranean sofritos according to the type of vegetables (garlic and onions) or olive oil added for their production. 相似文献
60.
Joan A. Higgins 《Journal of microscopy》1982,128(1):57-67
The endoplasmic reticulum has the enzymic machinery for the synthesis of both protein and phospholipid and hence plays a central role in its own biogenesis and that of other cellular membranes. The evidence available concerning the biogenesis of the phospholipid bilayer of the endoplasmic reticulum, particularly from the application of fine structural cytochemical methods for the localization of acyltransferases, is reviewed. The observations are consistent with a model in which phospholipid is synthesized in situ at the site of membrane growth. Synthesis is asymmetric, with most enzymes located at the cytoplasmic side of the membrane, and controlled transmembrane movement of phospholipid results in an asymmetric bilayer. 相似文献