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排序方式: 共有341条查询结果,搜索用时 921 毫秒
331.
Environmental Geochemistry and Health - Environmental isotope techniques were applied to study the hydrochemical characteristics of groundwater in Soc Trang Province, Southern Vietnam, in frame of...  相似文献   
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In goitred gazelles (Gazella subgutturosa), sexual dimorphism of larynx size and position is reminiscent of the case in humans, suggesting shared features of vocal ontogenesis in both species. This study investigates the ontogeny of nasal and oral calls in 23 (10 male and 13 female) individually identified goitred gazelles from shortly after birth up to adolescence. The fundamental frequency (f0) and formants were measured as the acoustic correlates of the developing sexual dimorphism. Settings for LPC analysis of formants were based on anatomical dissections of 5 specimens. Along ontogenesis, compared to females, male f0 was consistently lower both in oral and nasal calls and male formants were lower in oral calls, whereas the first two formants of nasal calls did not differ between sexes. In goitred gazelles, significant sex differences in f0 and formants appeared as early as the second week of life, while in humans they emerge only before puberty. This result suggests different pathways of vocal ontogenesis in the goitred gazelles and in humans.  相似文献   
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Objective

We aimed to investigate how the presence of fetal anomalies and different X chromosome variants influences Cell-free DNA (cfDNA) screening results for monosomy X.

Methods

From a multicenter retrospective survey on 673 pregnancies with prenatally suspected or confirmed Turner syndrome, we analyzed the subgroup for which prenatal cfDNA screening and karyotype results were available. A cfDNA screening result was defined as true positive (TP) when confirmatory testing showed 45,X or an X-chromosome variant.

Results

We had cfDNA results, karyotype, and phenotype data for 55 pregnancies. cfDNA results were high risk for monosomy X in 48/55, of which 23 were TP and 25 were false positive (FP). 32/48 high-risk cfDNA cases did not show fetal anomalies. Of these, 7 were TP. All were X-chromosome variants. All 16 fetuses with high-risk cfDNA result and ultrasound anomalies were TP. Of fetuses with abnormalities, those with 45,X more often had fetal hydrops/cystic hygroma, whereas those with “variant” karyotypes had different anomalies.

Conclusion

Both, 45,X or X-chromosome variants can be detected after a high-risk cfDNA result for monosomy X. When there are fetal anomalies, the result is more likely a TP. In the absence of fetal anomalies, it is most often an FP or X-chromosome variant.  相似文献   
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This study aimed at statistically investigating the association between the internal exposure of children and young adults to uranium (U) and epidemiologically relevant external determinants of exposure. The investigation was performed with data from two studies within the framework of the German health-related environmental monitoring program: The German Environmental Survey for Children (GerES IV) conducted by the Federal Environment Agency (Umweltbundesamt) with data on 1,780 children 3–14 years of age and their home environment and the German Environmental Specimen Bank (ESB, section: human specimens) with data on 2,253 students 20–29 years of age. Both studies provided data on the U levels in human urine for all probands. GerES IV furthermore provided an extensive environmental and demographic database on, e.g., U levels in drinking water. The data from GerES IV and ESB were linked by GIS to spatially relevant exposure information, including background values of U in stream sediments and in upper and lower soils, U levels in mosses and particulate matter in the lower atmosphere, precipitation and elevation as well as forest density. Bivariate correlation analysis and two decision tree models showed moderate but significant associations between U in human urine and U levels in drinking water, stream sediments and upper and lower soils. Future investigations considering additional epidemiologically relevant data sets may differentiate the results. Furthermore, the sample design of future environmental epidemiology studies should take the spatial evaluation of the data into greater account.  相似文献   
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Environmental Science and Pollution Research - Per- and polyfluoroalkyl substances (PFASs) are today considered important constituents of the continuously growing substance group of persistent...  相似文献   
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