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41.

Objectives

First-trimester ultrasound screening is increasingly performed to detect fetal anomalies early in pregnancy, aiming to enhance reproductive autonomy for future parents. This study aims to display the current practice of first-trimester ultrasound screening in developed countries.

Method

An online survey among 47 prenatal screening experts in developed countries.

Results

First-trimester structural anomaly screening is available in 30 of the 33 countries and is mostly offered to all women with generally high uptakes. National protocols are available in 23/30 (76.7%) countries, but the extent of anatomy assessment varies. Monitoring of scan quality occurs in 43.3% of the countries. 23/43 (53.5%) of the respondents considered the quality of first-trimester ultrasound screening unequal in different regions of their country.

Conclusions

First-trimester screening for structural fetal anomalies is widely offered in developed countries, but large differences are reported in availability and use of screening protocols, the extent of anatomy assessment, training and experience of sonographers and quality monitoring systems. Consequently, this results in an unequal offer to parents in developed countries, sometimes even within the same country. Furthermore, as offer and execution differ widely, this has to be taken into account when results of screening policies are scientifically published or compared.  相似文献   
42.

Objective

We performed a 1-year evaluation of a novel strategy of simultaneously analyzing single nucleotide variants (SNVs), copy number variants (CNVs) and copy-number-neutral Absence-of-Heterozygosity from Whole Exome Sequencing (WES) data for prenatal diagnosis of fetuses with ultrasound (US) anomalies and a non-causative QF-PCR result.

Methods

After invasive diagnostics, whole exome parent-offspring trio-sequencing with exome-wide CNV analysis was performed in pregnancies with fetal US anomalies and a non-causative QF-PCR result (WES-CNV). On request, additional SNV-analysis, restricted to (the) requested gene panel(s) only (with the option of whole exome SNV-analysis afterward) was performed simultaneously (WES-CNV/SNV) or as rapid SNV-re-analysis, following a normal CNV analysis.

Results

In total, 415 prenatal samples were included. Following a non-causative QF-PCR result, WES-CNV analysis was initially requested for 74.3% of the chorionic villus (CV) samples and 45% of the amniotic fluid (AF) samples. In case WES-CNV analysis did not reveal a causative aberration, SNV-re-analysis was requested in 41.7% of the CV samples and 17.5% of the AF samples. All initial analyses could be finished within 2 weeks after sampling. For SNV-re-analysis during pregnancy, turn-around-times (TATs) varied between one and 8 days.

Conclusion

We show a highly efficient all-in-one WES-based strategy, with short TATs, and the option of rapid SNV-re-analysis after a normal CNV result.  相似文献   
43.
Enteric duplications are rare lesions, and relatively few cases have been diagnosed prenatally. We present, to our knowledge, the first case of an associated communicating ileal duplication cyst in a huge omphalocele diagnosed prenatally. The prenatal ultrasound findings revealed four features of the cystic lesion including peristaltic movements of the cystic wall, communication between the cyst and normal bowel lumen, intra-cystic echogenic contents, and echogenic mesenteric tissue (fat) close to the cyst. These distinct characteristics helped us to make a firm in utero diagnosis. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
44.
45.
We aimed to analyse the influence of cholesterol and triglycerides, and of tobacco, coffee and alcohol consumption upon correlations between serum concentrations of organochlorine compounds (OCs) in patients with exocrine pancreatic cancer (EPC). Incident cases of EPC diagnosed in eastern Spain were prospectively identified (N=144). OCs were analysed by high-resolution gas chromatography with electron-capture detection. A strong correlation was observed between hexachlorobenzene (HCB) and beta-hexachlorocyclohexane (beta-HCH) (Spearman's rho=0.758). beta-HCH showed rho>0.4 with p,p'-DDT, p,p'-DDE, PCB138 and PCB153 (all p<0.001). Some correlations among compounds were slightly affected by tobacco, coffee or alcohol consumption. We observed a striking diversity of correlation patterns by strata of cholesterol and triglycerides. Most correlations were higher in the lowest category of triglycerides than in the lowest category of cholesterol. Most coefficients above 0.7 were seen in the lowest category of triglycerides (e.g., OC pairs p,p'-DDT and HCB, p,p'-DDT and beta-HCH, p,p'-DDE and beta-HCH, or HCB and beta-HCH). Correlations among OCs may be stronger when concentrations of triglycerides are low than when they are high. This is compatible with a dilution in the early phases of cancer and with a concentration effect as triglycerides become lower in the advanced phases of the disease.  相似文献   
46.
Predation on gibbons is rarely observed in the wild. However, the gibbons' moderate body size and relatively small social groups suggest high vulnerability to predation. To assess the role of predation and to study their anti-predator behaviour, we presented visual predator models to nine groups of wild white-handed gibbons at Khao Yai National Park, Thailand. We measured subjects' immediate and delayed responses to four potential predators: tiger, clouded leopard, crested serpent eagle and reticulated python. Subjects reliably approached all four predators. In response to tigers and leopards, they additionally produced predator-specific songs and defecated copiously. In terms of delayed responses, distance between mated adults decreased, but only after exposure to the tiger model. In response to eagles and pythons, gibbons consistently vocalised, but this did not always include predator singing, and we found no long-term effects in overall activity or strata use. However, during 6 of 26 predator encounters, the gibbons produced songs with a structure that was intermediate between a duet song and a predator song more than 20 min after the predator encounter, indicating a long-term effect on their vocal behaviour. This study demonstrates that gibbons discriminate between different potential predators and respond to them with adaptive anti-predator behaviour, which include predator-specific vocal responses. We conclude that gibbons are not immune to predation and that terrestrial predators elicit consistent immediate and delayed anti-predation responses.  相似文献   
47.
The present research examined the effects of employee age on managers attributions and actions toward subordinates. The major prediction was that managers attributions would mediate the effects of age on managerial actions. One-hundred and twenty-four undergraduate management students participated in a laboratory experiment in which subordinate age (30 versus 60 years) and performance (high versus low) were manipulated. A laboratory study was conducted so that subordinate credentials and performance levels could be controlled. Analyses indicated that poor performance by older subordinates was attributed more to stable factors than similar performance by younger subordinates. In addition, job simplification was rated as more appropriate and training was recommended as less appropriate for older subordinates. A series of hierarchical regression analyses indicated that the differences in managerial actions were a function of subjects' attributional patterns. Implications of the findings for practice and future research are discussed.  相似文献   
48.
The aim of this study was to determine the maternal population, pregnancy, serum alpha-fetoprotein (AFP) and free β subunit of human chorionic gonadotrophin (FβhCG) parameters in a large series of women attending prenatal clinics before 15 weeks' gestation and to assess the practical problems of population screening for Down's syndrome in the first trimester using these markers. Serum samples were collected from 8600 women attending prenatal clinic booking visits. Maternal serum AFP and FβhCG medians were calculated for each day of gestation (49–104 days), using both dates and ultrasound estimates of gestation. The effects of maternal weight, twin pregnancies, and threatened abortion on AFP and FβhCG levels were analysed. The median age of the population was 27.1 years and the median weight 62.1 kg. Twenty-six per cent of samples were collected before 70 days and 50 per cent before 78 days' gestation. Eighty-nine per cent of all samples had gestational estimates by dates, 60 per cent by ultrasound and 52 per cent by both dates and ultrasound. The AFP median was 5 kU/1 at 49 days, 5.9 kU/1 at 70 days, and 17.9 kU/1 at 100 days. The peak median FβhCG level was 66.4 ng/ml at 64 days, falling to 20.6 ng/ml at 100 days' gestation. Both AFP and FβhCG levels showed log Gaussian distributions but the standard deviation for AFP was 20 per cent greater than that found in the second trimester. AFP and FβhCG levels showed an inverse relationship with maternal weight and were increased in twin pregnancies (1.68 and 1.97 multiples of the median, respectively). AFP and FβhCG can be readily measured in a large screening population in the first trimester. Down's syndrome screening protocols based on these markers could be refined by the use of gestations in individual days but AFP is likely to be a less effective marker and detection rates are likely to be lower than in the second trimester. To realize the potential of first-trimester screening, more women should be encouraged to attend the prenatal clinic in early pregnancy and ultrasound dating should be carried out for all pregnancies at this stage.  相似文献   
49.

Trimethylamine (TMA) is an odorous volatile organic compound emitted by industries. Algal-based biotechnologies have been proven as a feasible alternative for wastewater treatment, although their application to abate polluted air emissions is still scarce. This work comparatively assessed the removal of TMA in a conventional bacterial bubble column bioreactor (BC) and a novel algal-bacterial bubble column photobioreactor (PBC). The PBC exhibited a superior TMA abatement performance compared to the conventional BC. In this sense, the BC reached a removal efficiency (RE) and an elimination capacity (EC) of 78% and 12.1 g TMA m?3 h?1, respectively, while the PBC achieved a RE of 97% and a EC of 16.0 g TMA m?3·h?1 at an empty bed residence time (EBRT) of 2 min and a TMA concentration ~500 mg m?3. The outstanding performance of the PBC allowed to reduce the operating EBRT to 1.5 and 1 min while maintaining high REs of 98 and 94% and ECs of 21.2 and 28.1 g m?3·h?1, respectively. Moreover, the PBC improved the quality of the gas and liquid effluents discharged, showing a net CO2 consumption and decreasing by ~ 30% the total nitrogen concentration in the liquid effluent via biomass assimilation. A high specialization of the bacterial community was observed in the PBC, Mumia and Aquamicrobium sp. being the most abundant genus within the main phyla identified.

GraphicalAbstract

  相似文献   
50.
The aim of this study was to examine the fate of the organothiophosphorus pesticide methidathion during anaerobic digestion of biological waste. Three reactor experiments were conducted under various conditions of temperature, pH and retention time. The influence of pH and temperature as well as the partitioning between solid and aqueous phase were studied in batch experiments. The mesophilic (25, 35 degrees C) reactor experiments showed a decline to about 10% of the maximum methidathion concentration within 30-80 d. In the thermophilic (55 degrees C) reactor experiment, methidathion disappeared within 20 d. The batch experiments showed an abiotic hydrolysis of methidathion over the experiment period of 4 d, accelerated by alkaline conditions (pH 10.5 and 12.8) and high temperatures (55 degrees C). The hydrolysis was also noticeable at a neutral pH, while methidathion was most stable at weakly acid pH values. Methidathion bonded strongly to the biological waste, and the amount released into the water phase was below the maximum aqueous solubility. About 10% of methidathion remained non-extractable. High concentrations of dissolved organic carbon and yeast extract as a model substance for disintegrated cells further reduced the content of methidathion in the water phase, possibly caused by co-sorption to the solid organic matter.  相似文献   
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