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21.
The main goal of the paper was to assess the pattern of risk factors having an impact on the onset of early wheezing phenotypes in the birth cohort of 468 two-year olds and to investigate the severity of respiratory illness in the two-year olds in relation to both wheezing phenotypes, environmental tobacco smoke (ETS) and personal PM2.5 exposure over pregnancy period (fine particulate matter). The secondary goal of the paper was to assess possible association of early persistent wheezing with the length of the baby at birth. Pregnant women were recruited from ambulatory prenatal clinics in the first and second trimester of pregnancy. Only women 18–35 years of age, who claimed to be non-smokers, with singleton pregnancies, without illicit drug use and HIV infection, free from chronic diseases were eligible for the study. In the statistical analysis of respiratory health of children multinomial logistic regression and zero-inflated Poisson regression models were used. Approximately one third of the children in the study sample experienced wheezing in the first 2 years of life and in about two third of cases (67%) the symptom developed already in the first year of life. The early wheezing was easily reversible and in about 70% of infants with wheezing the symptom receded in the second year of life. The adjusted relative risk ratio (RRR) of persistent wheezing increased with maternal atopy (RRR = 3.05; 95%CI: 1.30–7.15), older siblings (RRR = 3.05; 95%CI: 1.67–5.58) and prenatal ETS exposure (RRR = 1.13; 95%CI: 1.04–1.23), but was inversely associated with the length of baby at birth (RRR = 0.88; 95%CI: 0.76–1.01). The adjusted incidence risk ratios (IRR) of coughing, difficult breathing, runny/stuffy nose and pharyngitis/tonsillitis in wheezers were much higher than that observed among non-wheezers and significantly depended on prenatal PM2.5 exposure, older siblings and maternal atopy. The study shows a clear inverse association between maternal age or maternal education and respiratory illnesses and calls for more research efforts aiming at the explanation of factors hidden behind proxy measures of quality of maternal care of babies. The data support the hypothesis that burden of respiratory symptoms in early childhood and possibly in later life may be programmed already in prenatal period when the respiratory system is completing its growth and maturation.  相似文献   
22.
In this study the values of subcooled vapor pressures (log PL) were estimated for 209 trans chloroazobenzenes (Ct-ABs) that fill some gaps in analytical and experimental data on these compounds. There are 209 chloro derivatives of trans azobenzenes that are relatively stable and more environmentally relevant than 209 chloro cis congeners. The calculations models were based on the Quantitative Structure-Property Relationship (QSPR) scheme using the semi-empirical method (PM6) in molecular package (MOPAC) software and density functional theory (DFT) method using B3LYP functional and 6-311++G** basis set) in Gaussian 03 software method and the artificial neural networks (ANNs) prediction. The values of log PL predicted by models used varied between ?3.94 to ?2.66 for Mono-; ?4.85 to ?2.97 for Di-; ?5.18 to ?3.17 for Tri-; ?6.02 to ?3.77 for Tetra-; ?6.64 to ?4.64 for Penta-; ?7.36 to ?4.76 for Hexa-; ?7.54 to ?5.79 for Hepta-; ?7.75 to ?6.64 for Octa-; ?7.89 to ?7.44 for Nona-Ct-Abs; and ?8.09 and ?8.13 for Deca-Ct-AB. Based on these values Ct-ABs can be grouped localized among relatively low (log PL ?4 to ?2) and low (log PL < ?4) mobile Persistent Organic Pollutants (POPs). Both the calculation methods employed were characterized by similar prediction ability of subcooled vapor pressure values of Ct-ABs, while those of PM6 are much more efficient due to a cheaper hardware used and around 300-fold less time spent on calculations.  相似文献   
23.
Environmental Science and Pollution Research - The paper evaluates the contents of total forms of selected heavy metals (Zn, Cu, Ni and Pb) as well as the activity of catalase (CAT), dehydrogenases...  相似文献   
24.
Mussels of the genus Mytilus are widespread in both northern and southern hemispheres. Mytilus taxa are very important components of marine coastal ecosystems, but are difficult to differentiate morphologically. Sequencing and Sequenom MassARRAY iPLEX genotyping technology was used to identify and verify novel SNP markers in three European taxa of Mytilus: M. edulis, M. galloprovincialis, and M. trossulus. SNPs were localized in coding and non-coding sequences of some functionally important genes. Eight SNPs located in genes of the histone family, hsp70 and p53, were discovered and applied as novel markers for Mytilus taxa on a large European scale. Five of these differentiated the M. trossulus genome, two M. galloprovincialis, and one M. edulis. Other SNPs differentiated populations within taxa. The new SNPs will be a valuable tool for population studies of European Mytilus mussels. The percentage of polymorphic SNPs ranged from 19 to 100 % in 24 samples of mussels studied. Populations from Scotland, Mecklenburg Bight, and Norway had over 90 % polymorphic loci. Most loci were in Hardy–Weinberg equilibrium in all samples except for the one from Scotland. The highest percentages of heterozygotes were observed in the Atlantic (Banyuls and Vigo) and North Sea (Tjarno and Westerschelde) populations. An excess of homozygotes was observed in samples from Scotland, Norway, and the Barents Sea. Correspondence and Structure analysis also demonstrated the great heterogeneity of these three samples.  相似文献   
25.
The use of surfactants in a bioremediation process is aimed at increasing the efficiency of the removal of hydrophobic contaminants from the environment. The subjects of the study were three alkyl polyglucosides (APGs) of different alkyl chain length: Glucopon 215 CS UP, Glucopon 600 CS UP, and Glucopon 650 EC. The impact of these surfactants on the surface properties of the test strain Pseudomonas fluorescens ATCC 14700, as well as on the biodegradation of diesel was tested. It was observed, that the length of alkyl chain has an influence on the cell surface properties. The modification of the cell surface hydrophobicity and the electrokinetic potential on the bacteria cells is dependent on the structure of Glucopon molecules. The elongation of alkyl chains in surfactant molecule caused an increase of the hydrophobic properties and a reduction of the electrokinetic potential on the bacteria cells. Moreover, the use of APGs below critical micelle concentration caused an increase of diesel oil biodegradation, especially in the case of Glucopons with longer alkyl chain (Glucopon 600 CS UP and 650 EC). The better diesel oil removal by tested strain after surfactant addition was correlated with the hydrophobic properties of bacteria strain.  相似文献   
26.
(210)Pb geochronology is a widely used tool in sedimentological studies aimed at the absolute ages of modern sediments (up to 100 years). (210)Pb activities required to model sedimentation regimes are measured using either alpha, gamma or beta spectrometry. Sediment accumulation rates derived from (210)Pb activity profiles measured by these methods are often used interchangeably in mass balance studies. Yet there is a lack of investigations considering the comparability of data derived using different analytical methods. Differences between methods could be caused by different behaviors of (210)Pb and (210)Po (used for alpha measurement) in the marine environment. In gamma spectrometry errors may arise when many gamma emitters are measured simultaneously and their activity peaks overlap. In alpha spectrometry chemical separation of (210)Po may result in analytical error due to incomplete sample dissolution. In the present study we evaluate total, supported and excess (210)Pb activities and their use in deriving sediment accumulation rates and (210)Pb excess inventories for three sediment cores collected from the Barents Sea. (210)Pb activities derived by alpha and gamma methods are shown to agree within counting error and there is also good agreement in the derived sediment accumulation rates. The inherent compatibility of analytical results based on alpha or gamma techniques is established.  相似文献   
27.
This study was undertaken to evaluate zinc's influence on the resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease. The experiment was conducted in a greenhouse of the University of Warmia and Mazury (UWM) in Olsztyn, Poland. Plastic pots were filled with 3 kg of sandy loam with pHKCl – 7.0 each. The experimental variables were: zinc applied to soil at six doses: 100, 300, 600, 1,200, 2,400 and 4,800 mg of Zn2+ kg?1 in the form of ZnCl2 (zinc chloride), and species of plant: oat (Avena sativa L.) cv. Chwat and white mustard (Sinapis alba) cv. Rota. Soil without the addition of zinc served as the control. During the growing season, soil samples were subjected to microbiological analyses on experimental days 25 and 50 to determine the abundance of organotrophic bacteria, actinomyces and fungi, and the activity of dehydrogenases, catalase and urease, which provided a basis for determining the soil resistance index (RS). The physicochemical properties of soil were determined after harvest. The results of this study indicate that excessive concentrations of zinc have an adverse impact on microbial growth and the activity of soil enzymes. The resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease decreased with an increase in the degree of soil contamination with zinc. Dehydrogenases were most sensitive and urease was least sensitive to soil contamination with zinc. Zinc also exerted an adverse influence on the physicochemical properties of soil and plant development. The growth of oat and white mustard plants was almost completely inhibited in response to the highest zinc doses of 2,400 and 4,800 mg Zn2+ kg?1.  相似文献   
28.
Determination of seven congeners of PCBs was carried out for sewage sludge before, during and after thermophilic digestion. The overall content of heavy metals (Zn, Cu, Ni, Cd, Pb, Cr) in sludge before and after digestion was determined. Moreover the concentration of heavy metals in particular chemical fractions of the sludge was analyzed. After the thermophilic digestion total concentration of seven PCBs was reduced by 47%, which suggests that thermophilic digestion affects PCB reduction positively. On the 10th d of the process, concentration of lower chlorinated PCBs increased, whereas those of higher chlorinated PCBs decreased. The thermophilic digestion process showed no accumulation of the studied heavy metals in the mobile fractions (exchangeable and carbonate) of the stabilized sewage sludge, except for nickel. The highest increase in zinc, copper, cadmium, and chromium concentration was observed in the organic-sulfide fraction, whereas the highest increase in lead was found in the residual fraction of the sludge. In case of nickel both fractions of organic-sulfide and exchangeable-carbonate fractions were enriched.  相似文献   
29.
30.
Organic and conventional crops were studied by identifying the relationship between persistent organic pollutants in cereals, vegetables and soil. The residues of organochlorine pesticides and polychlorinated biphenyls (PCBs) were determined in grains (rye and wheat), vegetables (carrots and beets) and soil collected from the fields. PCB residues recorded in the beets from organic farming were as high as 3.71 ppb dry weight (dry wt.), while in the soil from conventional farming of beets 0.53 ppb dry wt. Among vegetables, higher concentrations of pesticides were detected in organically grown beets (190.63 ppb dry wt.). Soil samples from the organic farming contained lower levels of organochlorine pesticide residues compared to the conventional farming. Taking into account toxicity equivalent (TEQ), the conventionally grown carrots accumulated the most toxic PCBs. Non-ortho and mono-ortho PCBs were also noted in the grain of conventionally grown rye and amounted to 3.05 pg-TEQ/g wet wt.  相似文献   
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