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51.
Human cytomegalovirus (CMV) is an ubiquitous pathogen, with a high worldwide seroprevalence. When acquired in the prenatal period, congenital CMV (cCMV) is a major cause of neurodevelopmental sequelae and hearing loss. cCMV remains an underdiagnosed condition, with no systematic screening implemented in pregnancy or in the postnatal period. Therefore, imaging takes a prominent role in prenatal diagnosis of cCMV. With the prospect of new viable therapies, accurate and timely diagnosis becomes paramount, as well as identification of fetuses at risk for neurodevelopmental sequelae. Fetal magnetic resonance imaging (MRI) provides a complementary method to ultrasound (US) in fetal brain and body imaging. Anterior temporal lobe lesions are the most specific finding, and MRI is superior to US in their detection. Other findings such as ventriculomegaly, cortical malformations and calcifications, as well as hepatosplenomegaly, liver signal changes and abnormal effusions are unspecific. However, when seen in combination these should raise the suspicion of fetal infection, highlighting the need for a full fetal assessment. Still, some fetuses deemed normal on prenatal imaging are symptomatic at birth or develop delayed cCMV-associated symptoms, leaving room for improvement of diagnostic tools. Advanced MR sequences may help in this field and in determining prognosis, but further studies are needed. 相似文献
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Paula Paíga Kaline Amaral Wanderley Severino Alves Júnior C.M. Delerue-Matos 《毒物与环境化学》2015,97(6):687-699
Carbamate compounds are an important group of cholinesterase inhibitors. There is a need for creating awareness regarding the risks of the inadequate carbamate use in the residential areas due to potential adverse human effects. Carbaryl is a commonly used pesticide worldwide. A simple, fast, and high-throughput method was developed employing liquid chromatography with fluorescence detector to determine carbaryl residues in rat feces. The extraction was performed by using a rapid, easy, cheap, effective, reliable, and safe (QuEChERS) method, using acetonitrile as the extracting solvent. The parameters for the performance of the extraction method were optimized, such as ratio of mass of sample per volume of extraction solvent, QuEChERS content, and cleanup columns. Linear response was obtained for all calibration curves (solvent and matrix-matched) over the established concentration range (5–500 μg/L) with a correlation coefficients higher than 0.999. The achieved recovery was 97.9% with relative standard deviation values of 1.1% (n = 4) at 167 μg/kg fortified concentration level and the limits of detection and quantification were 27.7 and 92.3 µg/kg, respectively. 相似文献
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Immediate behavioural responses to earthquakes in Christchurch,New Zealand,and Hitachi,Japan 总被引:1,自引:0,他引:1
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Michael K. Lindell Carla S. Prater Hao Che Wu Shih‐Kai Huang David M. Johnston Julia S. Becker Hideyuki Shiroshita 《Disasters》2016,40(1):85-111
This study examines people's immediate responses to earthquakes in Christchurch, New Zealand, and Hitachi, Japan. Data collected from 257 respondents in Christchurch and 332 respondents in Hitachi revealed notable similarities between the two cities in people's emotional reactions, risk perceptions, and immediate protective actions during the events. Respondents' physical, household, and social contexts were quite similar, but Hitachi residents reported somewhat higher levels of emotional reaction and risk perception than did Christchurch residents. Contrary to the recommendations of emergency officials, the most frequent response of residents in both cities was to freeze. Christchurch residents were more likely than Hitachi residents to drop to the ground and take cover, whereas Hitachi residents were more likely than Christchurch residents to evacuate immediately the building in which they were situated. There were relatively small correlations between immediate behavioural responses and demographic characteristics, earthquake experience, and physical, social, or household context. 相似文献
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Sam M. Jones Jelle S. van Zweden Christoph Grüter Cristiano Menezes Denise A. Alves Patrícia Nunes-Silva Tomer Czaczkes Vera L. Imperatriz-Fonseca Francis L. W. Ratnieks 《Behavioral ecology and sociobiology》2012,66(1):1-12
Recent research has shown that entrance guards of the stingless bee Tetragonisca angustula make less errors in distinguishing nestmates from non-nestmates than all other bee species studied to date, but how they
achieve this is unknown. We performed four experiments to investigate nestmate recognition by entrance guards in T. angustula. We first investigated the effect of colony odours on acceptance. Nestmates that acquired odour from non-nestmate workers
were 63% more likely to be rejected while the acceptance rate of non-nestmates treated with nestmate odour increased by only
7%. We further hypothesised that guards standing on the wax entrance tube might use the tube as an odour referent. However,
our findings showed that there was no difference in the acceptance of non-nestmates by guards standing on their own colony’s
entrance tube versus the non-nestmate’s entrance tube. Moreover, treatment of bees with nestmate and non-nestmate resin or
wax had a negative effect on acceptance rates of up to 65%, regardless of the origin of the wax or resin. The role of resin
as a source of recognition cues was further investigated by unidirectionally transferring resin stores between colonies. Acceptance
rates of nestmates declined by 37% for hives that donated resin, contrasting with resin donor hives where acceptance of non-nestmates
increased by 21%. Overall, our results confirm the accuracy of nestmate recognition in T. angustula and reject the hypothesis that this high level of accuracy is due to the use of the wax entrance tubes as a referent for
colony odour. Our findings also suggest that odours directly acquired from resin serve no primary function as nestmate recognition
cues. The lack of consistency among colonies plus the complex results of the third and fourth experiments highlight the need
for further research on the role of nest materials and cuticular profiles in understanding nestmate recognition in T. angustula. 相似文献
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Axel?HochkirchEmail author Tamara?Mertes Julia?Rautenberg 《Die Naturwissenschaften》2012,99(3):217-224
Biological invasions can affect the structure and function of ecosystems and threaten native plant species. Since most weeds
rely on mutualistic relationships in their new environment, they may act as new competitors for pollinators. Pollinator competition
is likely to be density dependent, but it is often difficult to disentangle competition caused by flower quality from effects
caused by flower quantity. In order to test the effects of the presence and number of flowers of the invasive weed Bunias orientalis on the insect visitation rates in a native species (Sinapis arvensis), we performed two replacement experiments using plants with standardised flower numbers. The visitation rates in S. arvensis were significantly higher than in B. orientalis and the number of insect visits dropped significantly with increasing density of S. arvensis flowers. These results suggest that intraspecific competition among flowers of S. arvensis is stronger than the competitive effect of alien flowers. As flowers of B. orientalis do not seem to distract visitors from S. arvensis, it is unlikely that pollinator competition between these two plant species plays a crucial role. However, it cannot be excluded
that mass blossom stands of B. orientalis may distract flower visitors from native species. 相似文献