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171.
In this study we evaluated the feasibility of second-trimester transabdominal chorionic villus sampling for prenatal diagnosis of β-thalassaemia in 80 pregnancies at risk presenting in the second trimester at the Antenatal Service. Sampling was carried out from 13 to 20 weeks and was successful in all cases. The amount of chorionic villi obtained varied from 10 to 40 mg, which was sufficient to make fetal diagnosis by oligonucleotide analysis within 10 days from sampling in all cases. No fetal losses occurred. From these results we conclude that transabdominal chorionic villus sampling is a useful procedure for prenatal diagnosis of β-thalassaemia in those couples presenting after the first trimester.  相似文献   
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173.
Twenty woman at risk of carrying a fetus with homozygous beta-thalassemia who underwent fetoscopy and a matched control group of pregnant women were administered the Symptom Questionnaire to evaluate changes in distress. Women who were offered fetoscopy had significantly more anxiety, depression, somatic symptoms and hostility than the control group. Psychological distress significantly decreased after the results of fetoscopy were communicated to the patient, and the decrease was similar in normal control women. Five other patients had a diagnosis of homozygous beta-thalassaemia and their pregnancies were terminated. Their psychological distress increased when they learned the outcome of fetoscopy, but decreased again after termination. Psychological reactions to fetoscopy and amniocentesis appear to be similar, yet women who undergo fetoscopy suffer from more psychological distress.  相似文献   
174.
It is well-known that Bactrocera oleae (olive fruit fly) females attract conspecific males by using 1,7-dioxaspiro[5,5]undecane (1) as the main component of their sex pheromone, and that 1 is produced in the female rectal gland. Although some authors have claimed that B. oleae males also attract females, to date no male-produced female attractants have been found in this species. In this paper, we report the first identification of a substance unique to males and able to attract females. The findings of the study include the following: (1) females responded in a bioassay to hexane extracts obtained from rectal glands of 15-day-old B. oleae males, (2) the presence of (Z)-9-tricosene (2) was consistently and unambiguously identified in these extracts using gas chromatography (GC) and GC-mass spectrometry methods, (3) in preliminary bioactivity tests, low doses (equivalent to a few males) of chemically and stereoisomerically pure synthetic (Z)-9-tricosene (2) attracted olive fruit fly females. Interestingly, compound 2, commonly called muscalure, is also a well-known component of the house fly (Musca domestica) sex pheromone.  相似文献   
175.
Lagrangian models of dispersion in marine environment   总被引:1,自引:0,他引:1  
Turbulent dispersion can be studied successfully by using Lagrangian particle models. In general, the prediction of correct concentration fields is a complex issue when the turbulent field is inhomogeneous and non-stationary. Two classes of Lagrangian dispersion models have been considered in this work, which are based on the Wiener process and the so called “well-mixed” criterion. In order to test the performances of these models and shed light on the underlying physical processes and modeling assumptions, four different numerical models have been compared and tested by means of their long time behavior by considering several study cases concerning idealized marine environment. Furthermore, the coupling of the community model Princeton Ocean Model (POM) with the Lagrangian model LASEMOD (LAgrangian SEa MODel) is used to investigate the temporal and spatial evolution of a passive pollutant released in the vicinity of the coast in the Tyrrhenian Sea basin. The simulation shows with reasonable accuracy the time evolution of both the hydrodynamic and the concentration fields and provides a useful insight into the evaluation of the environmental impact of pollutant releases along the coast.  相似文献   
176.
PE ball milling pretreatment induces higher H2 production and purity by gasification. Ca(OH)2 reacts at solid state with PE boosting H2 and capturing CO2. Ca(OH)2 significantly reduces methanation side-reaction. Polymer thermal recycling for hydrogen production is a promising process to recover such precious element from plastic waste. In the present work a simple but efficacious high energy milling pre-treatment is proposed to boost H2 generation during polyethylene gasification. The polymer is co-milled with calcium and nickel hydroxides and then it is subjected to thermal treatment. Results demonstrate the key role played by the calcium hydroxide that significantly ameliorates hydrogen production. It reacts in solid state with the polyethylene to form directly carbonate and hydrogen. In this way, the CO2 is immediately captured in solid form, thus shifting the equilibrium toward H2 generation and obtaining high production rate (>25 L/mol CH2). In addition, high amounts of the hydroxide prevent excessive methane formation, so the gas product is almost pure hydrogen (~95%).  相似文献   
177.
The Industrial District (I.D.) of Messina was the first public authority to consider useful the application of the Strategic Environmental Assessment (SEA) procedure for the development of an Industrial Plan regarding a coastal area. At the moment the I.D. includes six areas, but the application of the SEA concerns only the area of Pace del Mela (along the north-eastern coast of Sicily), where a “District of the two Seas” will be created, based on the synergetic development between an industrialized niche (shipbuilding) and touristic development (port and hotels). The area in which this type of intervention will occur is not in use at the moment and it was not possible to collect environmental data. For this reason, in order to describe the environmental features of this territory, we took into consideration a few indicators which could be easily identified, necessary for a post evaluation which considers the Environmental Impact Assessment (EIA) of the industrial and suburban structures to be built.  相似文献   
178.
Polycyclic aromatic hydrocarbons (PAHs) are widespread organic pollutants. Soils are a reservoir of PAHs because some soil constituents favour PAH accumulation. Therefore, soil is a key indicator of the degree of contamination. So far, studies mapping soil PAH levels over large territories are very rare. Here, we report the first nation-wide maps of soil PAHs in France. Results were obtained within the French National Soil Monitoring Network, which is the first European network monitoring systematically soil PAHs. We used advanced geostatistics to map PAH distribution over the whole French territory. Our results show clear trends of PAH levels at the nation scale. For instance, the highest PAH levels are found in Northern and Eastern France. This high contamination is explained by the intense industrial activity of these regions during the last century. High levels of PAH are also found near some coastlines. This observation could be explained by long-range atmospheric transportation. In addition, we found that light PAHs are rarely found in French topsoils.  相似文献   
179.
Triasulfuron, a member of the sulfonylureas class of herbicides, was tested under laboratory conditions on the collembolan Onychiurus pseudogranulosus. Pure triasulfuron and commercial formulations at different rates (starting from a dose about 5 times the recommended agricultural rate) were tested separately on one-week old juveniles and adults reared in the laboratory. The persistence of the herbicide at the end of the trials lasting 30 and 60 days was verified by HPLC analysis. Laboratory tests indicated that only the rates exceeding 500 times the soil concentration expected soon after field application of the herbicide directly affected the tested species.  相似文献   
180.
Several samples of airborne particulate matter (PM), collected from 6th November to 6th December 2003 at a coastal site in the south-east of Italy, have been analyzed by different techniques to characterize elemental composition and morphological properties of the inorganic PM fraction and obtain preliminary results on anthropogenic contributions. Al, Cr, Cu, Fe, Mn, V, Pb, Ti, Ca and Zn mass concentrations, evaluated by an inductively coupled plasma atomic emission spectrometer, account for up to l% of the bulk PM mass in the investigated samples. According to geochemical calculations, Ca, Al, Fe and Mn are predominantly of crustal origin, while Cr, Cu, Pb, V, Ti and Zn heavy metals are of anthropogenic origin. Ion chromatography analyses have identified sulfate (SO(4)(2-)) nitrate (NO(3)(-)), sodium (Na(+)), and ammonium (NH(4)(+)) as the main ionic components accounting for up to 38% of the total PM mass and up to 90% of the total ionic mass. Besides ion chromatography, X-ray energy dispersive (EDX) microanalyses have revealed the high variability of Cl: its weight concentration varies from about 24% to below the detection limit (>or=0.5%) in the investigated samples. The marked anti-correlation between the excess of S and the Cl/Na ratio has allowed inferring that reactions between sea salt particles and acidic sulfates, which liberate HCl gas to the atmosphere leaving particles enriched in non-sea-salt sulfates, have significantly contributed to chloride depletion. Morphological analyses by scanning electron microscopy have shown that about 90% of the total sampled particles have a diameter 相似文献   
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