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1.
Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a potentially devastating condition, which may lead to intracranial haemorrhage (ICH) in the fetus or neonate, often with death or major neurological damage as consequence. In the absence of screening, preventive measures are only possible in the next pregnancy of women with an affected child. Controversy exists on the best intervention to minimise the risk of ICH. Most centres have abandoned treatment with serial fetal blood sampling (FBS) and platelet transfusions, because of a high rate of complications and the availability of quite effective non-invasive alternatives. In pregnancies with FNAIT and a previous affected child without ICH, weekly intravenous administration of immunoglobulins to the mother appears close to 100% effective to prevent fetal or neonatal ICH. Some centres add prednisone; this combination leads to slightly higher platelet counts at birth. In pregnant women with a previous child with ICH, the recurrence risk seems particularly high, and more aggressive maternal medical treatment is recommended, starting earlier with immunoglobulins. Whether a higher intravenous immunoglobulin dose or the addition of prednisone is really necessary is unclear. What does seem to be clear is that the use of FBS should be minimised, possibly even abandoned completely. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

2.
Management of maternal red cell alloimmunization has been revolutionized over the last 60 years. Advances in the prevention, screening, diagnosis, and treatment of alloimmune-induced fetal anemia make this condition an exemplar for contemporary practice in fetal therapy. Since survival is now an expectation, attention has turned to optimization of long-term outcomes following an alloimmunized pregnancy. In this review, the current management of red cell alloimmunization is described. Current research and future directions are discussed with particular emphasis on later life outcomes after alloimmune fetal anemia.  相似文献   

3.
DMPP (3,4-dimethylpyrazole phosphate) has been used to reduce nitrogen (N) loss from leaching or denitrification and to improve N supply in agricultural land. However, its impact on soil nitrifying organisms and enzyme activities involved in N cycling is largely unknown. Therefore, an on-farm experiment, for two years, has been conducted, to elucidate the effects of DMPP on mineral N (NH4^+- N and NO3^--N) leaching, nitrifying organisms, and denitrifying enzymes in a rice-oilseed rape cropping system. Three treatments including urea alone (UA), urea + 1% DMPP (DP), and no fertilizer (CK), have been carded out. The results showed that DP enhanced the mean NH4^+-N concentrations by 19.1%-24.3%, but reduced the mean NO3^--N concentrations by 44.9%-56.6% in the leachate, under a two-year rice-rape rotation, compared to the UA treatment. The population of ammonia oxidizing bacteria, the activity of nitrate reductase, and nitrite reductase in the DP treatment decreased about 24.5%-30.9%, 14.9%-43.5%, and 14.7%-31.6%, respectively, as compared to the UA treatment. However, nitrite oxidizing bacteria and hydroxylamine reductase remained almost unaffected by DMPP. It is proposed that DMPP has the potential to either reduce NO3^--N leaching by inhibiting ammonia oxidization or N losses from denitrification, which is in favor of the N conversations in the rice-oilseed rape cropping system.  相似文献   

4.
Examination of the fetal heart has become an established part of mid-trimester anomaly scanning. Along side this has emerged the ability to diagnose congenital heart disease in the fetus with accuracy. Despite this, the development of screening programmes to look for fetal cardiac disease has only been partially successful. Furthermore, when detected, there seems to be little survival advantage associated with prenatal diagnosis. Demonstrating such an advantage is complicated by the nature of fetal cardiac disease, which tends to be severe and is often associated with extra-cardiac abnormalities. More selective studies, mostly involving small numbers of cases, are now beginning to demonstrate both improved survival and reduced morbidity in prenatally diagnosed infants presenting to cardiac intensive care units compared to those with a postnatal diagnosis. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

5.
Fisheries management is the practice of analyzing and selecting options to maintain or alter the structure, dynamics, and interaction of habitat, aquatic biota, and man to achieve human goals and objectives. The theory of fisheries management is: managers or decision makers attempt to maximize renewable `output' from an aquatic resource by choosing from among a set of decision options and applying a set of actions that generate an array of outputs. Outputs may be defined as a tangible catch, a fishing experience, an existence value, or anything else produced or supported by renewable aquatic resources. Overall output is always a mix of tangible and intangible elements. However defined, management goals and objectives are essential components of fisheries management or any other field of renewable natural resource management. Reaching consensus on management goals and objectives has never been a simple task. Beyond the broad and often conflicting goals of an agency, managers must decide who should set specific management objectives — agency personnel, the public, or a combination of the two. Historically, rhetoric aside, fisheries managers in North America nearly always have consulted with professionals in governmental roles to set management objectives. In a strongly pluralistic society, this often resulted in protracted political and legal conflict. Increasingly, there are calls for use of risk assessment to help solve such ecological policy and management problems commonly encountered in fisheries management. The basic concepts of ecological risk assessment may be simple, but the jargon and details are not. Risk assessment (and similar analytical tools) is a concept that has evoked strong reactions whenever it has been used. In spite of the difficulties of defining problems and setting management objectives for complex ecological policy questions, use of risk assessment to help solve ecological problems is widely supported. Ecological risk assessment will be most useful (and objective) in political deliberations when the policy debate revolves around largely technical concerns. To the extent that risk assessment forces policy debate and disagreement toward fundamental differences rather than superficial ones, it will be useful in decision making.  相似文献   

6.
水解酸化—序批式活性污泥法在处理屠宰废水工程中的应用   总被引:10,自引:0,他引:10  
卓奋  张平 《环境工程》1998,16(5):7-9
在实验室研究的基础上,将水解酸化—序批式活性污泥(HA—SBR)处理工艺应用于屠宰废水治理工程中,运行结果表明,在进水CODCr600~2000mg/L、BOD5400~1000mg/L、氨氮40~100mg/L时,处理后出水水质可达到《广州市污水排放标准》新扩改一级标准。该处理工艺除设备简单、占地少、运行管理简便外,还具有剩余污泥量少和不产生污泥膨胀等优点。  相似文献   

7.
余辉 《环境科学研究》2013,26(9):956-965
以琵琶湖富营养化综合治理历程为主线,对琵琶湖30余年的治理过程、资金投入、治理措施、成功经验与成果进行了梳理. 截至2006年,琵琶湖综合整治历时35a,总投资约2.86×1012日元(约相当于1800×108元人民币),参照我国GB 3838—2002《地表水环境质量标准》,目前琵琶湖北湖水质维持在Ⅰ类水平,南湖由Ⅲ~Ⅳ类水恢复到I~Ⅱ类水质. 琵琶湖的治理分为2个阶段:第一阶段为1972—1997年,历时25a,这一阶段在琵琶湖水资源有效利用及防洪防灾上取得很大成就,但水质与环境仍在恶化; 1999年至今为第二阶段,主要目标是水质保护、水源涵养及自然环境与景观保护,目前琵琶湖富营养化已得到有效控制. 琵琶湖采取的综合治理措施主要包括依法治湖、中长期综合治理规划、流域污染源系统控制、自动监测系统及专门研究机构建立以及公众参与等5个方面. 主要治理经验包括:①严格控制氮、磷污染源,管网及大型污水处理设施建设着眼于未来长远规划,污水处理深度除磷脱氮技术的普及是污染源系统控制的关键;②大力提高森林覆盖率以减少面源污染的产生,改善水源涵养及流域生境;③切实做到有法必依、执法必严,实现依法治湖;④高度重视环境教育及公众参与;⑤积极推动各科研机构对环境问题的研究.   相似文献   

8.
Congenital diaphragmatic hernia is a rare disease associated with high mortality and morbidity. Antenatal ultrasound screening identifies more than 70% of cases, providing the opportunity for in utero referral to a tertiary care center for expert assessment and perinatal management. Additional genetic and morphologic assessment may be used to rule out associated anomalies. In isolated cases, the outcome may be predicted prenatally by medical imaging. The combination of lung size and liver herniation is a widely accepted method to stratify fetuses into groups with an increasing degree of pulmonary hypoplasia and corresponding mortality rates. Ultrasound measurement of the observed to expected lung-to-head ratio (o/e LHR) is most widely used. The o/e LHR is an independent predictor of survival and short-term morbidity. Finally, evaluation of stomach position has recently been introduced as an indirect method to estimate severity of the disease in left-sided defects, as it has been shown to correlate with the proportion of intrathoracic liver. Herein, we propose a protocol for the standardized ultrasound assessment of fetuses with isolated CDH and individualized prediction of neonatal outcome.  相似文献   

9.
Feto-fetal transfusion syndrome contributes heavily to high rates of perinatal mortality and morbidity in monochorionic multiple pregnancies. Its prenatal management has been controversial for at least 25 years. We review the recent literature in order to present the basis for a pragmatic reappraisal of the management of this condition. Laser surgery of the chorionic plate inter-twin anastomoses is the best first-line treatment when the syndrome develops before 26 weeks' gestation. Survival (including quality of survival) and gestational age at delivery are improved when compared to serial amnioreduction. Second-line treatment options include repeat-laser, intra-uterine blood transfusion, serial amnioreduction, selective feticide using bipolar cord coagulation or elective delivery, depending upon gestational age and the severity of the disease and its complications. We have found that fetoscopic placental surgery has proven itself over simplicity of amnioreduction. There is no evidence that treatment should be customized according to the stage of the disease at diagnosis. Early recognition of the syndrome through fortnightly serial ultrasound follow-up of all monochorionic pregnancies should ensure timely referral and make up for geographical constraints. Laser surgery should now be available in fetal medicine units that are managing at least 20 cases per year. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

10.
生物流化床在焦化废水治理中的应用   总被引:13,自引:0,他引:13  
采用厌氧 缺氧 好氧工艺流程,以生物膜作为厌氧、缺氧反应器,循环式生物流化床作为好氧反应器进行了焦化废水治理中试应用研究。应用结果表明,上述工艺流程用于焦化废水治理是可行的。当系统进水CODCr浓度小于1200mg/L,系统水力停留时间为44h时,出水CODCr小于250mg/L;较高的进水NH3 N浓度可严重影响NH3 N去除,但对CODCr去除几乎无影响  相似文献   

11.
天然水体环境温度对生物修复工艺除NH+4-N效果影响分析   总被引:1,自引:0,他引:1  
采用弹性填料微孔曝气生物修复方法净化受污染的某饮用水源,探讨了天然水体环境温度变化对生物除NH4^ -N作用效果的影响。结果表明,水体环境温度对生物修复工艺除NH4^ -N作用影响很大,水温越高,生物修复工艺除NH4^ -N效果越好,在较低的水体环境温度下,水温变化对生物修复工艺除NH4^ -N作用效果影响最大;在日常水体环境温度下,水温变化对生物修复工艺除NH4^ -N作用效果影响最小;在水体环境温度较高条件下,水温变化对生物修复工艺除NH4^ -N作用效果影响较小。  相似文献   

12.
上海市郊中小河流氮磷污染特征   总被引:18,自引:2,他引:16  
:①上海市郊中小河流有很高的氮磷和有机负荷,其表层水凯氏氮、总磷和CODCr指标均数倍于V类水的最大允许值.②由于受纳污染物类型和总量上的差异,中小河流氮磷污染存在明显的空间分异:居民区附近的小河流氨氮和磷的污染很重;主要受农田径流影响的小河流,氨氮和磷的污染较轻,但受硝氮污染的风险加大;养殖场附近的小河流,氨氮和磷有突发性暴增的现象.③中小河流氮磷污染,还受河流季节性生态环境演变的影响.随着气温升高和河流表层生物量的增大,表层水NH4+、NO3-因大量消耗而降低;有机N和颗粒态P含量因生物量的增加而上升;NO2-也会因硝化细菌活动的加剧而增加.水溶态磷和总磷也有随着气温和生物活动的增加而增高的趋势,但还要受到水体pH、DO等条件的影响.④在盛夏高温季节,水流滞缓的小河流表层水和底层水的氮磷指标存在明显分异:底层水NH4+、水溶态磷和总反应态磷含量高于表层水;而表层水NO3-和NO2含量高于底层水.这种富营养化水质分层现象的产生是夏季河流表层生物量暴增和底泥氮磷释放加剧的必然结果.至秋季,随着气温的回落,水质分层现象逐渐减弱.  相似文献   

13.
Noroviruses are a common cause of both endemic and epidemic gastroenteritis. These highly infectious viruses usually cause self-limited disease, but chronic infections occur in highly immunocompromised patients and unusual manifestations are also being described in some populations. Histoblood-group antigen expression is now recognized as an important susceptibility factor for many norovirus strains, but a correlate of acquired immunity to infection or illness has not yet been identified. Currently, treatment and prevention strategies rely on non-specific measures. However, virus-like particles containing capsid antigens are undergoing evaluation as a vaccine candidate for illness prevention. This article reviews the biologic properties, epidemiology, clinical features, host susceptibility, diagnosis, and treatment and prevention of norovirus infection.  相似文献   

14.
液膜法处理氨氮废水工艺条件研究   总被引:5,自引:0,他引:5  
采用液膜法处理低浓度氨氮废水,处理后出水中NH_3-N为1mg/L以下,SS、pH、COD均达到工业废水排放标准。对液膜组成及用量,膜增强剂选用,外相废水pH选择等工艺条件及其组合效果进行民试验,结果确定以20%硫酸为内相,6%Span-80 11%液体石蜡 煤油为液膜组成、pH9.0~9.5废水为外相的处理体系,能达到最佳处理效果。  相似文献   

15.
北方城镇中小型污水处理厂进水的水质、水温变化较大,冬季水温在12℃以下,低温对氨氮去除效果有明显影响。根据几种传统生物法污水处理工艺的比较表明,CASS工艺比较适合城镇中小型污水处理厂。为研究出比CASS工艺更适合北方中小城镇污水处理厂的工艺方法,以宁安市污水处理厂为研究对象加入悬浮填料技术并对传统AO工艺进行改造.在污染物去除率、占地面积、工程造价生产成本方面与CASS工艺进行比较。其中,COD和NH3-N污染物去除率分18℃和40℃水温两个周期进行检测对比。以上比较结果为北方城镇中小型污水厂的工艺选择及优化运行提供技术支持及理论依据。  相似文献   

16.
The prenatal detection of urinary tract anomalies is changing paediatric practice but in many areas the impact on clinical outcome remains difficult to quantify. However it is already apparent that termination of pregnancy has reduced the numbers of infants with lethal pulmonary hypoplasia and renal dsyplasia who would previously have been liveborn but destined to succumb as neonates. Similarly, referrals of major non lethal abnormalities such as bladder exstrophy are declining as parents increasingly opt for termination. Fetuses at greatest risk of early onset postnatal renal failure can now be identified with considerable accuracy on prenatal ultrasound. Termination, prompted by quality of life considerations, could result in reduced numbers of infants and young children requiring end stage renal failure treatment in the first few years of life. Pre natal detection of anomalies such as PUJ obstruction and reflux undoubtedly provides an opportunity to avert functional deterioration and minimise urinary infection. But the proportion of children who genuinely benefit has proved difficult to assess. The prenatal detection of mild dilatation is of doubtful benefit in all but a minority of cases. Clinically significant underlying pathology is rare yet this common prenatal finding often generates disproportionate parental anxiety. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

17.
采用淹没式膜法水解-交替脉冲曝气系统对城市污水的处理效能进行研究,讨论了装置进水COD浓度变化对生活污水处理效果的影响、处理工艺沿程COD、NH3-N浓度变化状况、NH3-N的去除、水解对COD去除效果的影响以及进水COD/N比与反硝化的关系。研究表明,该系统能有效地去除COD和NH3-N。进水COD在450mg/L以下时,出水COD基本维持在60mg/L以下;进水NH3-N<50mg/L时,出水NH3-N<10mg/L。  相似文献   

18.
Owing to changes in agricultural practices throughout Europe, with greater emphasis on intensification, traditionally managed hay meadows have become scarce. Their loss has also meant the loss of species diversity. One of the few areas of Europe where traditional management is still practised is in Northern Spain.The hay meadows of Northern Spain can be defined as semi-natural, species-rich communities that are maintained by one or more factors which are under the direct control of man. The traditional management to which they are subjected has led to a high species diversity. For centuries the meadows have been important to man in supporting cattle during the winter. There is now little need for further increase of production. However, the importance of the need for conservation of species diversity and protection of ecologically sensitive areas is now recognised. Although the biological richness of the hay meadows is well known, few studies have been made of the effects of different traditional management regimes on the diversity and floristic composition of these grasslands.A survey was carried out to examine the effects of traditional management on the floristic composition, diversity and production of these meadows. The area studied is situated in the Valdeón valley, northwestern Spain (Cantabrian Mountains) and consists of a deep valley in which arboreal vegetation is represented by beech (Fagus sylvatica) forests. The survival of semi-natural habitats and traditional forms of management and also the low use of chemical fertilisers compared with Northern Europe are the most important reasons for the richness of these habitats. In this study, cutting for hay once per year, non-irrigation non-manuring and grazing in autumn was correlated with high species diversity. The future conservation of these habitats will depend on the formulation of support to continue with traditional management practices.  相似文献   

19.
钝顶螺旋藻处理氨氮废水的研究   总被引:3,自引:0,他引:3  
螺旋藻是一种营养丰富的新型保健食品,利用含氮废水为培养基,研究螺旋藻以NH4-N的处理效率,着重探讨利用生活污水培养螺旋藻的可行性,及其对生活污水的处理效果。研究证明,在NH4-N浓度小于40.0mg/L时,其对NH4-N的去除率最大,可达93%左右。在体积百分比生活污水为80%时,添加NaHCO38mg/L,对NH4-N的去除率达91.8%。同时对螺旋藻化学组分及含铁、锌、锰、铜、硒进行分析,生活污水培养螺旋藻,其所含有机物和氮源,可供螺旋藻生长繁殖,使废水资源化,并减少环境污染;藻粉可作为饲料添加剂,是使废水变为蛋白源的有效途径。  相似文献   

20.
Advances in cardiac surgical techniques taking place over the past 50 years have resulted in the vast majority of children born with congenital cardiac malformations now surviving into adulthood. As the focus shifts from survival to the functional outcomes of our patients, it is increasingly being recognized that a significant proportion of patients undergoing infant cardiac repair experience adverse neurodevelopmental (ND) outcomes. The etiology of abnormal brain development in the setting of congenital heart disease is poorly understood, complex, and likely multifactorial. Furthermore, the efficacy of therapies available for the learning disabilities, attention deficit, and hyperactivity disorders and other ND deficits complicating congenital heart disease is currently uncertain. This situation presents a challenge for prenatal counseling as current antenatal testing does not usually provide prognostic information regarding the likely ND trajectories of individual patients. However, we believe it is important for parents to be informed about potential issues with child development when a new diagnosis of congenital heart disease is disclosed. Parents deserve a comprehensive and thoughtful approach to this subject, which conveys the uncertainties involved in predicting the severity of any developmental disorders encountered, while emphasizing the improvements in outcomes that have already been achieved in infants with congenital heart disease. A balanced approach to counseling should also discuss what local arrangements are in place for ND follow-up. This review presents an up-to-date overview of ND outcomes in patients with congenital heart disease, providing possible approaches to communicating this information to parents during prenatal counseling in a sensitive and accurate manner.  相似文献   

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