environmental sample
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Proceedings series
663 s.
In this study a non-conductive biological sample is observed free of charging artefacts when placed on a cooled Peltier stage in the specimen chamber of an alternative form of the environmental scanning electron microscope, equipped with a specially designed hydration system. This system was used to create dynamically changing surrounding conditions leading to controlled dehydration of the sample enabling us to visualize the topographical structure of a rat tongue in the transition region between the liquid and the gas state of water in the microscope specimen chamber.
- MeSH
- jazyk chemie ultrastruktura MeSH
- krysa rodu rattus MeSH
- mikroskopie elektronová rastrovací metody přístrojové vybavení MeSH
- teplota MeSH
- tlak MeSH
- voda chemie MeSH
- vysoušení metody přístrojové vybavení MeSH
- životní prostředí MeSH
- změna skupenství MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
OBJECTIVE: To compare environmental factors that influence body mass index for age (BMI-for-age) between a sample of American and Czech school-aged children. DESIGN: Pilot study. A parent questionnaire and school visits were used to collect data from parents and children. SETTING: Public schools in 1 American and 2 Czech cities. PARTICIPANTS: Forty-five American and 97 Czech 4(th)- through 6(th)-graders and their parents. VARIABLES MEASURED: Parenting style, food socialization and preparation practices, healthful food availability, and children's BMI-for-age were measured. ANALYSIS: Factors from the parental scales were derived using factor analysis. Independent t tests compared environmental factors between American and Czech families. A regression model was used to identify environmental variables associated with BMI-for-age. RESULTS: American parents used authoritative parenting style and positive food socialization practices more often than Czech parents (P <.001). Availability of healthful food and parental involvement in food preparation were higher (P <.001) in Czech households. Positive encouraging socialization practices, less frequent use of negative explanations, and a greater availability of vegetables were associated with lower BMI-for-age in the Czech sample of children. CONCLUSIONS AND IMPLICATIONS: A future study should focus on identifying environmental factors that influence children's BMI-for-age with a large sample of Czech and American parents and their school-aged children.
- MeSH
- dieta etnologie normy MeSH
- dítě MeSH
- dospělí MeSH
- fyziologie výživy dětí MeSH
- index tělesné hmotnosti MeSH
- lidé MeSH
- nadváha epidemiologie MeSH
- pilotní projekty MeSH
- průzkumy a dotazníky MeSH
- rodičovství psychologie MeSH
- shluková analýza MeSH
- sociální chování MeSH
- společenská třída * MeSH
- srovnání kultur MeSH
- životní prostředí * MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- Geografické názvy
- Česká republika MeSH
- Spojené státy americké MeSH
The natural sources of Tl are less bioavailable and hence of less concern in regulation than its anthropogenic sources. Tl is more toxic to mammals than Hg. Cd, Pb, Ag, Cu or Zn and has been responsible for many poisonings. Tl occurs in two oxidation states, Tl(I) and Tl(III), the former being the predominant species in natural environment. In contrast to inorganic compounds, in which the Tl(I) ion is more stable in aqueous solutions than the Tl (III) ion, the latter is more stable in organic compounds. As the Tl concentrations in environmental samples are in the µg kg-1 range or less, it is necessary to use separation and preconcentration techniques, such as coprecipitation. The frequently used methods of Tl fractionation and speciation analysis are extraction, ion exchange and ion chromatography. They are combined with Tl determination using voltammetry, neutron activation analysis, spectrophotometry, mass spectrometry, inductively coupled plasma optical emission spectrometry and electrothermal and hydride-generation AAS.
Expozícia matky znečisťujúcim látkam (xenobiotikám) počas tehotenstva predstavuje aj potenciálnu expozíciu plodu ich transportom cez placentu. Environmentálne xenobiotiká môžu mať nepriaznivý vplyv na kvalitu intrauterinného života a ovplyvniť vývoj senzitívneho imunitného systému plodu. Od r. 1996 prebieha na Slovensku medzinárodný projekt “Epidemiologický výskum alergických ochorení u deti v SR“, zameraný na skúmanie vzťahu medzi vybranými faktormi životného prostredia (vrátane xenobiotík) a vývojom alergických ochorení (AO) u detí. Do projektu bolo zaradených 1978 matiek/1992 novorodencov z 8-ich environmentálne odlišných regiónov SR. U náhodne vybraných matiek (N=360) sa po pôrode (40±2 týždne) odobrali vzorky placenty na histopatologické vyšetrenie a na analýzy koncentrácií vybraných xenobiotík, ako aj vzorky pupočníkovej krvi na vyšetrenie hladiny celkového imunoglobulínu E (uIgE). V 1. roku života bolo na prítomnosť/neprítomnosť AO fyzikálne vyšetrených regionálnymi alergológmi 1326/1992 detí. Zistili sme rozdiely v koncentrácií analyzovaných xenobiotík v placentách medzi regiónmi. Koncentrácie kadmia (Cd) a olova (Pb) pozitívne korelovali s výskytom ischemickej proliferácie placentárneho syncýciotrofoblastu. Celkovo 37, 2 % detí malo pozitívne hodnoty koncentrácie celkové uIgE (>0,35 kU/L). Koncentrácia Cd v placente negatívne korelovala s koncentráciou celkového uIgE (r=-0,2; p<0,001). Incidencia AO u 1-ročných detí bola 13,9 %. Vyšší obsah Pb v placente pozitívne koreloval s vyšším výskytom symptómov astmy (SA) u detí (p< 0,05), pričom SA sa častejšie vyskytovali u detí matiek, ktoré fajčili pred tehotenstvom (25 % vs. 11 %, p<0,05). Monitorovanie individuálnej expozície xenobiotikám počas gravidity je novým prístupom, ktorý môže prispieť k objasneniu kvality intrauterinného života vo vzťahu k atopii.
Maternal exposure to environmental pollutants (xenobiotics) during pregnancy represents potential exposure of the foetus via placental transfer. Environmental xenobiotics may have an adverse effect on the quality of intrauterine life and may affect the sensitisation of foetal immune system. International project „Epidemic investigation of allergic diseases among children in the SR“ focused on the relationship between selected environmental factors (including xenobiotics) and allergy (AD) development in children, has been launched in 1996 in Slovakia. In 8 environmentally different Slovak regions 1978 mothers with their 1992 newborns were recruited. In randomly selected mothers (N=360), set of samples was taken at delivery: placental samples for histopathological and chemical analyses, and umbilical blood samples for the measurements of total IgE (uIgE). Placental concentrations of cadmium (Cd) and lead (Pb) positively correlated with the frequency of ischemic proliferation of syncytiotrophoblast. Positive levels of total uIgE (>0.35 kU/L) were found in 37.2 % children. Placental Cd concentration was in negative correlation with total uIgE (r=-0.2; p<0.001). The incidence of AD was 13.9 % in 1-year-old children. Higher placental Pb concentration positively correlated with the frequency of asthma respiratory symptoms (ARS) in children (p<0.05). ARS in children was higher if mother smoked before pregnancy (25 % vs. 11 %, p<0.05, aOR=2.61; 95%CI: 1.19, 5,69). Monitoring of environmental exposure to xenobiotics during pregnancy represents a new approach towards elucidation of the role of intrauterine life quality in atopy development.
- MeSH
- alergie diagnóza etiologie MeSH
- dítě MeSH
- dospělí MeSH
- kovy MeSH
- lidé MeSH
- matka - expozice noxám MeSH
- placenta fyziologie MeSH
- těhotenství MeSH
- xenobiotika analýza metabolismus škodlivé účinky MeSH
- znečištění životního prostředí MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- přehledy MeSH
- srovnávací studie MeSH
- Geografické názvy
- Slovenská republika MeSH
Samples of lichens, snow and particulate matter (PM10, 24 h) are used for the source identification of air pollution in the heavily industrialized region of Ostrava, Upper Silesia, Czech Republic. An integrated approach that uses different environmental samples for metal concentration and Pb isotope analyses was applied. The broad range of isotope ratios in the samples indicates a combination of different pollution sources, the strongest among them being the metallurgical industry, bituminous coal combustion and traffic. Snow samples are proven as the most relevant indicator for tracing metal(loid)s and recent local contamination in the atmosphere. Lichens can be successfully used as tracers of the long-term activity of local and remote sources of contamination. The combination of PM10 with snow can provide very useful information for evaluation of current pollution sources.
- MeSH
- atmosféra chemie MeSH
- izotopy analýza MeSH
- kovy analýza MeSH
- látky znečišťující vzduch analýza MeSH
- lišejníky metabolismus MeSH
- monitorování životního prostředí metody MeSH
- pevné částice analýza MeSH
- průmysl MeSH
- sníh chemie MeSH
- uhlí analýza MeSH
- znečištění ovzduší analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
