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551.
A rare complication of twin-to-twin transfusion syndrome (TTTS) is described: myocardial infarction of the recipient fetus. Myocardial infarction and hydrops are considered to be consequences of hypertension in the recipient. No other organs were affected. Pathological signs of intrauterine hypertension were estimated by the thickness of vessel walls and signs of hypertrophied myocardial cells. In the heart of the recipient fetus there was a chronic myocardial infarction near the apex cordis on the anterior wall with an aneurysm 4×5 mm in diameter. Diagnosis was based on light microscopic examination. The poor myocardial systolic function resulted in hydrops. Since the mother was administered β sympathomimetics in therapeutic doses the contribution of the drug to the myocardial infarction is uncertain, but we would like to suggest this as a possible adverse effect in TTTS. The present case is the first reported myocardial infarction in connection with the syndrome. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
552.
Preimplantation genetic diagnosis (PGD) is an alternative to prenatal diagnosis for couples at risk of transmitting genetic disorders to their offspring. We present a fluorescence in situ hybridization (FISH) analysis of embryos obtained after seven PGD cycles in six couples with Robertsonian translocations and male factor infertility: 4 der(13;14), 1 der(14;21) and 1 der(15;21). Of 74 metaphase II (MII) injected oocytes, 61 (82.4%) fertilized normally and cleaved. Of these, 37/61 (60.7%) embryos were of high morphological quality with ≥6 blastomeres. After biopsy of 44 embryos at day 3 of development, seven degenerated, seven arrested in development and 30/44 (68.2%) evolved, of which 25/30 (83.3%) reached the morula/blastocyst stage. Analysis of biopsied blastomeres showed 23/44 (52.3%) of normal/balanced embryos, of which 15 (11 at the morula/blastocyst stage) were transferred in six cycles. One term pregnancy was achieved, which ended by cesarean section at 37 weeks of gestation, giving birth to two healthy newborn. Analysis of 49 embryos (excluding 12 inconclusive cases) showed a predominance of alternate segregation (38/49, 77.6%) over adjacent segregation (7/49, 14.3%), with one (2%) being a polyploid mosaic and three (6.1%) chaotic. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
553.
Little is known about seasonal changes in burrowing activity and burrow architecture in subterranean African mole-rats (Bathyergidae, Rodentia). The solitary genus Heliophobius is the least known genus of this family. We examined burrow systems of the silvery mole-rat ( Heliophobius argenteocinereus) in Malawi in two periods of the dry season. Burrow pattern was influenced by the time of the year, becoming more reticulated at the peak of the dry season when soil was dry and hard. Overall digging activity did not cease during the dry season; yet burrowing strategy changed and the soil was deposited in tunnels rather than transported to mounds. The length of burrow systems was correlated with the body mass of the respective occupants. In spite of their solitary habits – and contrary to the prediction of the aridity food-distribution hypothesis – silvery mole-rats are able to occupy poor habitats with low food supply.  相似文献   
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污水分散式处理有独特的优点,人工湿地是其中主要的方法,特别适合在农村地区因地制宜地处理生活污水,具有运行费用低、处理效果好的特点,在新农村环境建设中发挥了很大作用。但人工湿地用于污染程度高的行业废水处理国内比较少见。该文依据一项中德环保合作项目——人工湿地技术处理蕲春某屠宰厂废水的示范工程,对人工湿地建造有关的设计及运行管理问题进行总结与探讨。  相似文献   
557.
Food and Environmental Virology - Enteric viruses have been described as important contaminants in fresh and ready-to-eat foods such as sandwiches, deli meat and dairy products. This is a...  相似文献   
558.
Nectar acquisition in the honeybee Apis mellifera is a partitioned task in which foragers gather nectar and bring it to the hive, where nest mates unload via trophallaxis (i.e. mouth-to-mouth transfer) the collected food for further storage. Because forager mates exploit different feeding places simultaneously, this study addresses the question of whether nectar unloading interactions between foragers and hive-bees are established randomly, as it is commonly assumed. Two groups of foragers were trained to exploit a different scented food source for 5 days. We recorded their trophallaxes with hive-mates, marking the latter ones according to the forager group they were unloading. We found non-random probabilities for the occurrence of trophallaxes between experimental foragers and hive-bees, instead, we found that trophallactic interactions were more likely to involve groups of individuals which had formerly interacted orally. We propose that olfactory cues present in the transferred nectar promoted the observed bias, and we discuss this bias in the context of the organization of nectar acquisition: a partitioned task carried out in a decentralized insect society.  相似文献   
559.
本文表明农场主之间的联合经营体(partnership arrangements)可能是保障农场经济生存能力和提高效益的途径之一.本文讨论了三种不同协作类型的经验分析,并强调了与协作经营关联的环境改善.在第一个案例中,对牛奶场和种植农场的协作进行了分析,结果表明多样化的提高和轮作具有实质的潜在效益,当协作包括机械时,其潜在效益更高.第二个例子论及生猪育崽和精饲管理的外部综合条件.协作利润源于生物因子和技术因子两方面,诸如提高生长率和增加猪舍的利用率等.最后,本文对一组种植农场协作进行了评估,认为效益的增加主要得益于机械费用的减少和/或来自其它因素的收益,如轮作和管理、营销策略等的改善.  相似文献   
560.
Norovirus (NoV) is recognized as the most common cause of foodborne outbreaks. In 2014, an outbreak of acute gastroenteritis occurred on a cruise ship in Brazil, and NoV became the suspected etiology. Here we present the molecular identification of the NoV strains and the use of sequence analysis to determine modes of virus transmission. Food (cream cheese, tuna salad, grilled fish, orange mousse, and vegetables soup) and clinical samples were analyzed by ELISA, conventional RT-PCR, qRT-PCR, and sequencing. Genogroup GII NoV was identified by ELISA and conventional RT-PCR in fecal samples from 5 of 12 patients tested (41.7%), and in the orange mousse food sample by conventional RT-PCR and qRT-PCR. Two fecal GII NoV samples and the orange mousse GII NoV sample were successfully genotyped as GII.Pe (ORF 1), revealed 98.0–98.8% identities among them, and shared phylogenetically distinct cluster. Establishing the source of a NoV outbreak can be a challenging task. In this report, the molecular analysis of the partial RdRp NoV gene provided a powerful tool for genotyping (GII.Pe) and tracking of outbreak-related samples. In addition, the same fast and simple extraction methods applied to clinical samples could be successfully used for complex food matrices, and have the potential to be introduced in routine laboratories for screening foods for presence of NoV.  相似文献   
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