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排序方式: 共有1262条查询结果,搜索用时 281 毫秒
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Elisa Doné Leonardo Gucciardo Tim Van Mieghem Jacques Jani Mieke Cannie Dominique Van Schoubroeck Roland Devlieger Luc De Catte Philipp Klaritsch Steffi Mayer Veronika Beck Anne Debeer Eduardo Gratacos Kypros Nicolaides Jan Deprest 《黑龙江环境通报》2008,28(7):581-591
Congenital diaphragmatic hernia (CDH) can be associated with genetic or structural anomalies with poor prognosis. In isolated cases, survival is dependent on the degree of lung hypoplasia and liver position. Cases should be referred in utero to tertiary care centers familiar with this condition both for prediction of outcome as well as timed delivery. The best validated prognostic indicator is the lung area to head circumference ratio. Ultrasound is used to measure the lung area of the index case, which is then expressed as a proportion of what is expected normally (observed/expected LHR). When O/E LHR is < 25% survival chances are < 15%. Prenatal intervention, aiming to stimulate lung growth, can be achieved by temporary fetal endoscopic tracheal occlusion (FETO). A balloon is percutaneously inserted into the trachea at 26–28 weeks, and reversal of occlusion is planned at 34 weeks. Growing experience has demonstrated the feasibility and safety of the technique with a survival rate of about 50%. The lung response to, and outcome after FETO, is dependent on pre-existing lung size as well gestational age at birth. Early data show that FETO does not increase morbidity in survivors, when compared to historical controls. Several trials are currently under design. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Le Quang Dung Nguyen Viet Linh Nguyen Xuan Thanh Nguyen Duc Cu Vu Van Tu Takaomi Arai 《生态毒理学报》2015,10(3):304-310
Heavy metal concentrations in muscle and their relation to thegrowth of two marine fish species,including tonguefish( Cynoglossus arel) and mullet( Mugil cephalus),were studied. The samples were collected in Bach Dang estuary andconcentrations of heavy metals( As,Cd,Co,Mn,Cu,Zn,Pb,and V) in muscle of the fisheswere determined. The result showed that the accumulated trend of heavy metal is different between fish species. The concentration of As,Zn,Mn,V,Cu,Pb,Co and Cd in tonguefish were 73. 7 ± 30. 6,22. 82 ± 4.87,3. 44 ± 2. 13,1. 61 ± 0. 15,0. 71 ± 0. 13,0. 45 ± 0. 24,0. 03 ± 0. 02 and 0. 02 ± 0. 02 mg·g-1,respectively. Meanwhile the concentration of Zn,As,V,Mn,Cu,Pb,Co and Cd in mullet were 83. 41 ±19. 68,9. 78 ± 1. 92,1. 36 ± 0. 54,1. 29 ± 0. 51,0. 65 ± 0. 12,0. 42 ± 0. 20,0. 06 ± 0. 03 and0. 03 ± 0. 01mg·g-1,respectively. Comparison of metal levels among thesespecies indicated that the concentrations of As and Mn in tonguefish were significantly higher than those in mullet,whereas Zn levels in mullet were found to be higher than that in tonguefish. There is no significant differences of Cd,Co,Cu,Pb and V levels in muscle between two species. Significant inversed relationshipsbetween concentration levels of metals and lengths of tonguefish were found for Mn,Cu and Zn,butnot for As,Cd,Pb,and V. There were no significant relationships between the heavy metal concentrations and the length of mullet. In general,decreasesof the heavy metal concentrations corresponded to the increases of fish body lengths,particularly for As,Co,Cu,Mn and V and the exception for Cd. Terefore reduced risks were associated with consuming biggermullet fish,and increased risks of As and Cd were associated with consuming bigger tonguefish in Bach Dang river mouth. 相似文献
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Gryglewicz G Stolarski M Gryglewicz S Klijanienko A Piechocki W Hoste S Van Driessche I Carleer R Yperman J 《Chemosphere》2006,62(1):135-141
The hydrodechlorination (HDCl) process of 2,3-, 2,4- and 2,5-dichlorobiphenyls was studied over a sulphided Ni-Mo/Al(2)O(3) catalyst in a stirred autoclave at a hydrogen pressure of 3 MPa. The catalysts were prepared by spray-drying. They were characterized by N(2) adsorption, thermogravimetry and scanning electron microscopy with X-ray microanalysis. The reaction temperature of the catalytic HDCl process was varied in the range of 230-290 degrees C. Polychlorinated biphenyls (PCBs) free transformer oil was used as reaction medium. The HDCl degree of dichlorobiphenyl isomers was in the range of 82-93%. The efficiency in the chlorine removal was found to be related to the position of the substituted chlorine atom and decreased as follows 2,4-dichlorobiphenyl approximately 2,5-dichlorobiphenyl>2,3-dichlorobiphenyl. For comparison, the HDCl process of 2,3-dichlorobiphenyl (2,3-PCB) without catalyst was also studied. The chlorine removal was 85% for the catalytic HDCl of 2,3-PCB whereas non-catalytic process led only to 16% of dechlorination in the same operating conditions, i.e. at 290 degrees C after 120 min. Monodichlorobiphenyls were not detected in the reaction products. The data for both catalytic and non-catalytic conversion of 2,3-PCB fit to a first-order model. Kinetic constants and the activation energy of the overall HDCl reaction of 2,3-PCB to biphenyl were evaluated. Compared to non-catalytic process, a nearly threefold decrease in the activation energy was observed in the presence of Ni-Mo/Al(2)O(3) catalyst prepared by spray-drying (48 kJ mol(-1) vs. 124 kJ mol(-1)). 相似文献