heavy atom effect
Dotaz
Zobrazit nápovědu
This study aims to investigate the changes in atmospheric deposition trends in Bulgaria, studied using the moss biomonitoring technique since 1995. For the first time, a paired (site-wise) comparison was performed after a critical review of the sampling networks and adjusting for location, the distance between the sampling points, and moss species. Data from the 2005/2006 and 2015/2016 moss surveys were chosen as instrumental neutron activation analysis was employed in both to determine the content of 34 elements (Al, As, Ba, Br, Са, Ce, Cl, Со, Cr, Cs, Fe, Hf, I, K, La, Mn, Na, Nd, Ni, Rb, Sb, Sc, Se, Sr, Ta, Tb, Th, Ti, Tm, U, V, W, Yb, Zn). In addition, Cd, Cu, and Pb were determined using complementary analytical methods: inductively coupled plasma atomic emission spectroscopy in 2015/2016 and atomic absorption spectroscopy in 2005/2006. For the subset of 57 routinely sampled locations in Bulgaria, hierarchical clustering on principal components and multiple factor analysis (MFA) were applied to assess the spatial trends in the 10 years elapsed between the surveys, as well as to characterise the origin of the determined elements. Elevation and distance between the sampling points were used as additional variables in the multiple factor analysis plane to ascertain their effect on the overall variance in the datasets. Distribution maps were constructed to illustrate the deposition patterns for the pollutant Pb. The results were consistent with decreased industrial output in the country, increased coal combustion and transport pollution, and construction of roads.
- MeSH
- Bryophyta * MeSH
- látky znečišťující vzduch analýza MeSH
- monitorování životního prostředí MeSH
- průzkumy a dotazníky MeSH
- stopové prvky analýza MeSH
- těžké kovy analýza MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Geografické názvy
- Bulharsko MeSH
... xix -- International System of Units and Prefixes for Physical Quantities, xxiii -- SECTION 1 -- 1 Atoms ... ... Parvin -- Introduction, 2 Atomic Structure, 2 Particles, 2 -- The Atom and the Nucleus, 3 The Forces, ... ... , 39 Polarity Effect, 39 -- Alternative Dose Measurement Systems, 39 Film Dosimetry, 39 Semiconductor ... ... of Radiation, 49 Stochastic Hereditary Effects, 49 Stochastic Somatic Effects, 50 Nonstochastic Somatic ... ... Effects, 50 Dose Descriptors, 50 Equivalent Dose, 50 Effective Dose, 50 Background Radiation, 52 Legislative ...
Eighth edition xxiii, 615 stran : ilustrace, tabulky ; 28 cm
- MeSH
- nádory radioterapie MeSH
- nukleární lékařství metody MeSH
- radioterapie metody MeSH
- Publikační typ
- učebnice MeSH
- Konspekt
- Učební osnovy. Vyučovací předměty. Učebnice
- Lékařské vědy. Lékařství
- NLK Obory
- radiologie, nukleární medicína a zobrazovací metody
- onkologie
- NLK Publikační typ
- kolektivní monografie
A compromised detection of radiation-induced plasmid DNA fragments results in underestimation of calculated damage yields. Electrophoretic methods are easy and cheap, but they can only detect a part of the fragments, neglecting the shortest ones. These can be detected with atomic force microscopy, but at the expense of time and price. Both methods were used to investigate their capabilities to detect the DNA fragments induced by high-energetic heavy ions. The results were taken into account in calculations of radiation-induced yields of single and double strand breaks. It was estimated that the double strand break yield is twice as high when the fragments are at least partially detected with the agarose electrophoresis, compared to when they were completely omitted. Further increase by 13% was observed when the measured fragments were corrected for the fraction of the shortest fragments up to 300 base pairs, as detected with the atomic force microscopy. The effect of fragment detection on the single strand break yield was diminished.
The monitoring of various elements in the cow milk is important in the agricultural sector. The goal of this study was to determine the concentrations of calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), sodium (Na), nickel (Ni), lead (Pb), and zinc (Zn) in the milk samples coming from different origins (local region in Nitra, nationwide sample represents the common Slovak brands of milk and common brands of milk from Czech Republic widely available in Slovakia). The samples were analyzed using atomic absorption spectrometry. A high level of variability in the Cu, Fe, Na, Ni, and Zn contents was observed. Magnesium was comparatively high in the milk sample from Slovakia (273.23 ± 16.32 μg/mL) against sample from Nitra (230.91 ± 9.48 μg/mL) and Czech Republic (202.70 ± 10.83 μg/mL). Potassium was significantly higher in milk from Nitra region (3301.98 ± 95.66) against SK sample (2925.16 ± 75.74 μg/mL). There were no significant differences in other elements among the three regions. The provisional tolerable weekly intake (PTWI) contribution suggested low dietary exposure to observed toxic metals (Cd, Hg, and Pb) in milk samples. Margin of exposure (MOE) evaluation denoted that even higher consumption of milk poses no high cardiovascular and nephrotoxicity threat. However, Cd and Pb are known for their cumulative effect and the monitoring of these elements in milk is strongly required.
- MeSH
- dietární expozice analýza MeSH
- hodnocení rizik MeSH
- kontaminace potravin analýza MeSH
- mléko chemie normy MeSH
- stopové prvky analýza MeSH
- těžké kovy analýza MeSH
- xenobiotika analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
In this study, 14 commercial products (dietary supplements) containing alga Chlorella vulgaris and cyanobacteria Spirulina platensis, originated from China and Japan, were analysed. UV-vis spectrophotometric method was applied for rapid determination of chlorophylls, carotenoids and pheophytins; as degradation products of chlorophylls. High Performance Thin-Layer Chromatography (HPTLC) was used for effective separation of these compounds, and also Atomic Absorption Spectrometry for determination of heavy metals as indicator of environmental pollution. Based on the results obtained from UV-vis spectrophotometric determination of photosynthetic pigments (chlorophylls and carotenoids), it was confirmed that Chlorella vulgaris contains more of all these pigments compared to the cyanobacteria Spirulina platensis. The fastest mobility compound identified in Chlorella vulgaris and Spirulina platensis using HPTLC method was β-carotene. Spectral analysis and standard calibration curve method were used for identification and quantification of separated substances on Thin-Layer Chromatographic plate. Quantification of copper (Cu2+, at 324.7 nm) and zinc (Zn2+, at 213.9nm) was performed using Flame Atomic Absorption Spectrometry with air-acetylene flame atomization. Quantification of cadmium (Cd2+, at 228.8 nm), nickel (Ni2+, at 232.0nm) and lead (Pb2+, at 283.3nm) by Electrothermal Graphite Furnace Atomic Absorption Spectrometry; and quantification of mercury (Hg2+, at 254nm) by Cold Vapour Atomic Absorption Spectrometry.
- MeSH
- Chlorella vulgaris chemie MeSH
- chlorofyl chemie MeSH
- chromatografie na tenké vrstvě metody MeSH
- karotenoidy chemie MeSH
- potravní doplňky analýza MeSH
- spektrofotometrie atomová metody MeSH
- Spirulina chemie MeSH
- těžké kovy chemie MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Čína MeSH
- Japonsko MeSH
... -- 1.3 Quantum effects -- 1.3.1 Quantum numbers. ? ... ... -- 1.4 Hydrogen atom -- 1.4.1 Spectrum of the hydrogen atom 20 -- 1.5 Electron structure of heavy atoms ... ... 20 -- 1.6 Excitation and ionisation of atoms 22 -- 1.6.1 Binding energy of electrons in an atom 23 - ... ... - 1.7 Principle of mass spectroscopy 24 -- 1.8 Atomic nuclei 26 -- 1.8.1 Binding energy of a nucleus ... ... 27 -- 1.8.2 Magnetic properties of nuclei 28 -- 1.9 Forces acting between atoms 29 -- 1.9.1 Ionic bonds ...
1. elektronické vydání 1 online zdroj (226 stran)
... -- 1.3 Quantum effects -- 1.3.1 Quantum numbers. ? ... ... -- 1.4 Hydrogen atom -- 1.4.1 Spectrum of the hydrogen atom 20 -- 1.5 Electron structure of heavy atoms ... ... 20 -- 1.6 Excitation and ionisation of atoms 22 -- 1.6.1 Binding energy of electrons in an atom 23 - ... ... - 1.7 Principle of mass spectroscopy 24 -- 1.8 Atomic nuclei 26 -- 1.8.1 Binding energy of a nucleus ... ... 27 -- 1.8.2 Magnetic properties of nuclei 28 -- 1.9 Forces acting between atoms 29 -- 1.9.1 Ionic bonds ...
First English edition 224 stran : ilustrace ; 23 cm
- Konspekt
- Lékařské vědy. Lékařství
- Učební osnovy. Vyučovací předměty. Učebnice
- NLK Obory
- fyzika, biofyzika
- NLK Publikační typ
- učebnice vysokých škol
This review describes the features, importance and current state of analytical techniques used for the determination of antimony based on separation, optical, static and dynamic electrochemical principles. Antimony is an environmentally important element coming from industrial activities as well as from eroded deposits of metal ores. It may enter food chain and have toxic effects on human; hence its monitoring is necessary today. The most common analytical technique for the detection is atomic absorption spectrometry, which is however quite expensive. Therefore, novel techniques based on electrochemistry are being developed, because they are cheap, fast, and do not involve any complicated sample pretreatments.
Three monosubstituted 3-phenylselanyl and 3-phenyltellanyl BODIPY derivatives were synthesized and their spectroscopic properties were characterized and compared to those of iodine and chlorine-atoms containing analogues as well as an unsubstituted BODIPY derivative. The fluorescence quantum yields were found to decrease, whereas the intersystem crossing quantum yields (ΦISC), determined by transient spectroscopy, increased in the order of the H → Cl → Se/I → Te substitution. The maximum ΦISC, found for the 3-phenyltellanyl derivative, was 59%. The results are interpreted in terms of the internal heavy-atom effect of the substituents.
Olovo je kumulativní jed, který je zvláště nebezpečný pro malé děti. I při nízké úrovni expozice, která byla dříve považována za bezpečnou, poškozuje vývoj mozku a nervového systému, což vede k poruchám chování a snížení inteligence dětí. Hlavním zdrojem expozice olovu je potrava. Pitná voda může představovat významný příspěvek expozice olovu ve starých budovách s původními olověnými rozvody vody. Cílem prezentované práce bylo získat základní informaci o expozici olovu z pitné vody ve vytipovaných školských zařízeních ve starých budovách v Pardubickém kraji a o možném zdravotním riziku pro děti. V letech 2013 a 2014 byly v součinnosti se Zdravotním ústavem vyšetřeny vzorky pitné vody ve 20 školských zařízeních. Vzorky byly odebrány jak ráno po noční stagnaci vody v potrubí, tak náhodně během dne. Zvýšený obsah olova ve srovnání s dodávanou vodou z vodovodu byl zjištěn ve většině zařízení. V téměř polovině zařízení byly nalezeny zvýšené koncentrace olova i ve vzorcích náhodně odebraných během dne při provozu školy a ve 3 zařízeních bylo zjištěno překročení současného hygienického limitu 10 µg/l. Při charakterizaci rizika vývojové neurotoxicity u dětí byla použita Metodika rozdílu expozic (MOE), doporučená EFSA. Výsledkem je konstatování, že i podlimitní obsah olova v pitné vodě ve školském zařízení může představovat sice malé, ale ne úplně zanedbatelné riziko nepříznivého ovlivnění nervového vývoje u dětí. Do péče o zdravé prostředí předškolních a školních zařízení by proto měla patřit i eliminace tohoto potenciálního rizika.
Lead is a cumulative toxicant that is particularly harmful to young children. Even at lower levels of exposure that were previously considered safe, lead damages brain and nervous system development resulting in behavioural changes and decreased intelligence of children. The main source of lead exposure is food. An important contributor to lead exposure may be the tap water in old buildings, having the original lead plumbing. The aim of the present study was to obtain basic information about lead exposure from drinking water in selected educational facilities placed in old buildings in the Pardubice Region as well as the possible health risks for the children. Between 2013 and 2014, in collaboration with the Public Health Institute, samples of drinking water in 20 educational facilities were examined. The samples were taken both in the morning after overnight water stagnation in the pipes and randomly during the day. In most facilities the lead content was increased as compared to water regularly supplied in the mains. In almost half of the monitored facilities increased lead content was detected even in the samples taken during the day. In three facilities the lead content exceeded the current lead content limit 10 µg/l. To characterize the risk of developmental neurotoxicity in children, the methodology "margin of exposure" (MOE), recommended by EFSA, was used. The result is, that even a lower lead content in drinking water of school facilities than the regulatory limit value may pose a small but not entirely negligible risk of neurodevelopmental effects. Care for the healthy environment at preschool and school facilities should therefore also include the elimination of this potential risk.
- Klíčová slova
- vodovodní potrubí ve starých školoních budovách, hodnocení zdravotních rizik (HRA),
- MeSH
- centrální nervový systém metabolismus růst a vývoj MeSH
- dítě MeSH
- Evropská unie MeSH
- lidé MeSH
- mladiství MeSH
- olovo * izolace a purifikace metabolismus toxicita MeSH
- otrava olovem * diagnóza komplikace metabolismus MeSH
- pitná voda * analýza metabolismus škodlivé účinky MeSH
- poruchy nervového systému vyvolané otravou těžkými kovy diagnóza etiologie prevence a kontrola MeSH
- předškolní dítě MeSH
- školy MeSH
- směrnice pro lékařskou praxi jako téma normy MeSH
- statistika jako téma MeSH
- Světová zdravotnická organizace MeSH
- těhotné ženy MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- předškolní dítě MeSH
- Geografické názvy
- Česká republika MeSH
