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11.
Air samples collected in the German part of the North Sea from March to July 2010 were investigated for organophosphorus compounds (OPs) being applied as flame retardants and plasticizers. The ∑8OPs concentration ranged from 110 to 1400 pg m−3 while tris(2-chloroisopropyl) phosphate (TCPP) dominated all samples with individual concentrations up to 1200 pg m−3. The highest concentrations were observed in continental air masses showing the high influence of industrialized regions including production sites on atmospheric emissions and concentrations. The occurrence of OPs even in oceanic/Arctic air masses shows that OPs can undergo long-range atmospheric transport. Dry particle-bound deposition fluxes from 9 to 240 ng m−2 d−1 for ∑8OPs were estimated leading to a minimum annual flux of 710 ± 580 kg y−1 OPs into the German North Sea. This study presents the first occurrence of OPs in the marine atmosphere together with important information on their long-range transport potential.  相似文献   
12.
Dechlorane Plus (DP) has been determined in surface sediments from three Chinese coastal bays, e.g. Jiaozhou, Sishili and Taozi Bay in North China. DP concentrations ranged from <1.2 to 187 pg g−1 dry weight (dw) (mean: 24.7 pg g−1 dw) in Jiaozhou Bay, <1.2 to 135 pg g−1 dw (mean 69.9 pg g−1 dw) in Sishili Bay and <1.2 to 66.7 pg g−1 dw (mean: 40.4 pg g−1 dw) in Taozi Bay, respectively. Additionally, two dechlorinated species were quantified, which accounted for 0.6-5.1% of the ∑DP concentration.The fsyn values (syn-isomer/(syn- + anti-isomer)) in sediments from Jiaozhou Bay (mean 0.29) were close to the technical DP mixture (0.2-0.4), probably indicating local inputs of DP. In contrast, sediments in Sishili and Taozi Bay showed much lower fsyn values (mean 0.16). During transportation the DP isomers are subject to stereo selective degradation which partly resulted in the relative enrichment of anti-DP in coastal sediments.  相似文献   
13.
In order to obtain a large set of normal control values, the activities of three cytosolic enzymes of purine metabolism and seven lysosomal enzymes were determined in homogenates of chorionic villi derived from induced abortions of normal pregnancies (7th–12th week) in about 100 individual cases. Possible reasons for the rather wide ranges of normal distributions of enzyme activities are discussed. The values are compared: (1) with available data in the literature; (2) with activities determined in decidual homogenates prepared from the same samples; (3) with activities of cells of cultures established and grown from villi in the same samples; and (4) with enzyme activities measured in chorionic biopsies using the same methods. Implications for the prenatal diagnosis of the associated metabolic diseases are considered.  相似文献   
14.
Pigeon homing: the effect of a clock-shift is often smaller than predicted   总被引:1,自引:0,他引:1  
This analysis is based on 103 releases with 6-h clock-shifted pigeons of various ages and experiences. Resetting the internal clock normally leads to a significant change in initial orientation; however, in half of the cases, the induced deflections are significantly smaller than predicted by the sun compass hypothesis. The relative size of the deflections decreases with increasing age and experience (Fig. 3). Only young pigeons with limited experience respond as expected, while old birds show deflections which are, on the average, only slightly more than half of the predicted size, except at extremely familiar sites (Table 2). There is no difference between fast and slow shifts (Fig. 4). It is not possible to clearly specify under what circumstances smaller deflections occur; previous clock-shifts (Fig. 5), familiarity with the release site (Table 4) and duration of the shifting procedure (Table 5) do not seem to be the reasons. Clock-shifting also tends to decrease the vector lengths and has a marked effect on homing performance (Table 7). Nevertheless, considerable numbers of clock-shifted birds return on the day of release before their internal clock has begun to be reset back to normal. The general role of the sun compass in bird orientation is considered and theoretical implications of our findings are discussed in view of the map and compass-model and the possibility that an alternative, non-time-compensating compass is used in parallel with the sun compass.  相似文献   
15.
We report a case of chromosomal mosaicism for monosomy 21 revealed in amniotic fluid cell culture. Ultrasound examination at 19 weeks' gestation showed in utero growth retardation and a complex cardiac malformation. A repeated amniocentesis confirmed the presence of monosomy 21 mosaicism. In view of the sonographically detected fetal abnormalities, termination of pregnancy was elected.  相似文献   
16.
Rapid karyotyping in the second and third trimesters has important implications for the management of pregnancies at risk. From September 1985 to March 1992, 735 amniotic fluid samples sent to our laboratory for rapid karyotyping from 64 different diagnostic centres of the Federal Republic of Germany were included in a comparative study on harvesting for chromosome analysis using the ‘pipette method’ or the ‘in situ’ technique. The average time between preparation of the amniotic fluid and verbal notification of the analysed karyotype was 5·41 days. The ‘pipette method’ needed on average 4·65 days, and the ‘in situ’ technique 5·97 days. In comparison with other more invasive techniques available for rapid karyotyping such as cordocentesis and placental biopsy, amniocentesis and subsequent chromosome harvesting using the ‘pipette method’ and/or the ‘in situ’ technique proved very useful and efficient. The overall incidence of chromosome aberrations was 15·3 per cent. The high rate of structural chromosome aberrations and uncommon aneuploidies found in our investigation (12 per cent) indicates that for rapid karyotyping in the second and third trimesters, conventional cytogenetic techniques cannot be replaced by faster techniques based on fluorescent in situ hybridization on interphase cells in the near future.  相似文献   
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Abstract

The health effects of two pesticides, chlordimeform and propanil, are discussed. Chlordimeform and 2‐methyl‐4‐chloroaniline, a major metabolite of chlordimeform, cause severe hemorrhagic cystitis in humans. In cats, however, only a mild effect on the bladder was noted. The herbicide propanil has produced chloracne in humans, and along with 3,4‐dichloroaniline, hyperkeratosis in rabbits. The contaminants 3,4,3’,4'‐tetrachloroazobenzene and 3,4,3’,4'‐tetrachloroazoxybenzene are responsible for the chloracnegenic characteristics of propanil, 3,4‐dichloroaniline, and methazole.  相似文献   
20.
Indoor plants can remove volatile organic compounds (VOCs) from the air. The majority of knowledge comes from laboratory studies where results cannot directly be transferred to real-life settings. The aim of this study was to develop an experimental test system to assess VOC removal by indoor plants which allows for an improved real-life simulation. Parameters such as relative humidity, air exchange rate and VOC concentration are controlled and can be varied to simulate different real-life settings. For example, toluene diffusion through a needle gave concentrations in the range of 0.10–2.35 μg/L with deviations from theoretical values of 3.2–10.5 %. Overall, the system proved to be functional for the assessment of VOC removal by indoor plants with Hedera helix reaching a toluene removal rate of up to 66.5 μg/m2/h. The mode of toluene exposure (semi-dynamic or dynamic) had a significant influence on the removal rate obtained by H. helix.  相似文献   
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