Uniparental disomy in fetuses diagnosed with balanced Robertsonian translocations: risk estimate

Forty-two fetuses with non-homologous Robertsonian translocations were analyzed for uniparental disomy (UPD). One fetus with a de novo translocation t(13q;14q) had maternal isodisomy of chromosome 14. In a summary of the published data (including the present study), 315 cases were analyzed for UPD after prenatal diagnosis of balanced Robertsonian translocations, of these two fetuses had UPD, giving a risk estimate of 0.65% (CI 0.2–2.3). This risk justifies the recommendation of UPD analysis in fetuses diagnosed prenatally with Robertsonian translocations, with the emphasis on the chromosomes known to contain imprinted genes, such as 14 and 15. We also discuss the possibility of UPD in offspring of Robertsonian translocation carriers with normal karyotype. Based on the risk for UPD in fetuses with Robertsonian translocation we suggest to test these fetuses for UPD and to do so on amniocytes rather than chorionic villi when the risk for unbalanced karyotype is ∼1%, comparable to the risk for UPD. Copyright © 2002 John Wiley & Sons, Ltd.     

Human maternal uniparental disomy for chromosome 16 and fetal development

Two severely growth-retarded fetuses found to have maternal uniparental disomy (UPD) for chromosome 16 and trisomy 16 placental mosaicism both had an unfavourable outcome. Antenatally, the first case was complicated by an unexplained raised maternal serum alpha-fetoprotein concentration, preterm premature rupture of the membranes, and growth retardation detectable at 21 weeks' gestation, whilst the other had an unexplained raised maternal serum human chorionic gonadotrophin level, a two-vessel cord on ultrasound, and cessation of growth at 25 weeks. At post-mortem, both babies had an imperforate anus. Fetal maternal UPD may explain the poor outcome that occurs in some cases of confined placental mosaicism for chromosome 16 and is also associated with specific fetal abnormalities.     

Late-onset isolated cystic hygroma: The obstetrical significance,management, and outcome

We add two cases of prenatally diagnosed late-onset isolated cystic hygroma to the eight cases reported previously in the English literature. The obstetrical significance, management, and outcome of this entity are reviewed. A retrospective study of late-onset isolated cystic hygromas delivered in one medical centre between 1978 and 1992 was made. The medical records of these newborns served as the basis of the present report. A Medline search of the English literature was carried out. Over a period of 15 years, we observed 11 cases of late-onset congenital isolated cystic hygroma, two of whom had prenatal sonographic diagnosis. In one case, a Caesarean section was performed due to a huge lesion. All cases underwent surgical excision with a favourable outcome. Of the eight prenatally diagnosed cases reported previously, one died at birth due to inability to ventilate and two required a tracheostomy. Late-onset isolated cystic hygroma should be differentiated from the early-onset nuchal cystic hygroma. The differential diagnosis is important, as late-onset isolated cystic hygroma does not require any prenatal intervention, but special awareness during labour and Caesarean section in extreme cases. Transport to a perinatal centre with expert neonatal, respiratory, and paediatric surgical care is recommended. The prognosis in general is favourable.     

棕色碳气溶胶来源、性质、测量与排放估算

随着对碳气溶胶吸光性认识的提高,近年来吸光有机碳——BrC(brown carbon,棕色碳)的吸光问题成为继BC(black carbon,黑碳)之后国际大气环境领域的新热点. 基于已有的研究报道,将BrC大体分为焦油类物质、类腐殖质(HULIS)和其他吸光性有机气溶胶三大类,其来源包括一次排放和二次生成2种. 由于BrC缺少BC所具有的类石墨烯结构,致使颗粒间较为分散,加之含氧官能团比重较高,因而在水及有机溶剂中均有较强的可溶性. BrC的光学性质通常借助AAE(ngstrm吸收波长指数)、MAE(质量吸收效率)、RI(折射率)及SSA(单次散射反照率)来表示,其中由于BrC分子结构中缺少sp2杂化成分,形成了区别于BC的典型特征,即AAE>1(而对于BC,其AAE=1)). 虽然已有借助于光学法、热光法、化学法和质谱法进行BrC测定的报道,但目前没有公认的标准测定方法和参考物质,测定结果实际依赖于选定的测定方式. 在排放估算研究方面,BrC远落后于BC,致使有些排放估算方法多以相伴的BC排放量作为参照. 建议今后对BrC研究应主要面向气候影响、生成机理、测定方法、排放因子与控制策略等领域来展开.      

新时代社会主义生态文明建设理路的新转向

生态文明关系人民福祉、关乎民族未来。新中国成立以来,我国对生态环境问题经历了由重视不足到逐步重视再到纳入中国特色社会主义总体布局和战略布局的重大转变。党的十八大后形成的习近平生态文明思想,植根于中国古代生态智慧,在马克思恩格斯生态理论的指导下,在深刻总结新中国成立以来实践经验的基础上提出来的。应当从五位一体总体布局和四个全面战略布局的高度理解和把握习近平生态文明思想,才能在其科学指导下,开创中国特色社会主义生态文明新时代。     

生态时代消费问题的中国方案——读《自然之境:“消费—生态”悖论的伦理探究》

<正>建设生态文明,必须在节约能源资源和保护生态环境方面形成相应的产业结构、增长方式、消费模式。消费是人的本质的表现和确认,也是人的本质不断升华、不断发展的重要条件。此前全球金融危机的一个深刻结论是,传统消费模式是一条资源环境难以支撑的负重之路。因此,转变经济发展方式和消费方式成为当下生态文明建设的重要环节。曾建平教授所著的《自然之境:消费—生态悖论的伦理探究》(中国人民大学出版社2018年     

The significance of fetal ventriculomegaly: etiology,short- and long-term outcomes

Fetal cerebral ventriculomegaly (VM) is diagnosed when the width of one or both ventricles, measured at the level of the glomus of the choroid plexus (atrium), is ≥ 10 mm. VM can result from different processes: abnormal turnover of the cerebrospinal fluid (CSF), neuronal migration disorders, and destructive processes. In a high percentage of cases, it is associated with structural malformations of the central nervous system (CNS), but also of other organs and systems. The rate of associated malformations is higher (≥60%) in severe VM (>15 mm) and lower (10–50%) in cases of borderline VM (10–15 mm). When malformations are not present, aneuploidies are found in 3–15% of borderline VM; the percentage is lower in severe VM. The neurodevelopmental outcome of isolated VM is normal in > 90% of cases if the measurement of ventricular width is between 10 and 12 mm; it is less favorable when the measurement is > 12 mm. Copyright © 2009 John Wiley & Sons, Ltd.     

甘肃武山地热田水化学与地热水起源

通过对武山地热田地热水和地下冷水的水化学和同位素分析,结果表明武山地热水的出露温度为18.2~42.1℃,TDS含量为238~255 mg/L,属于低矿化度的HCO3型水。相对于地下冷水,地热水有更高的S iO2、F含量,说明经历了比冷水更长的循环深度。水化学特征表明武山地热水为大气降水与岩石相互作用的初级阶段。武山冷水和地热水的同位素沿着西北大气降水线分布,由于地热水的水岩相互作用时间较长,有更低的δD和δ18O值,说明武山地热水是大气来源的。综合运用各种地热温标估算武山地热水的热储温度范围在70~106℃之间,按照甘肃东部的平均地温梯度(35℃/km),得出武山地热水循环深度为1.74~2.77 km,属于中低温地热系统。此研究为今后可持续开发武山地热水提供了科学依据。     

渔业配额制度的起源、特点及展望

渔业配额制度是在渔业资源过度捕捞所导致的渔业危机和传统的投入控制管理失效的历史背景下,基于渔业资源生态特性而构建的一种产出控制的渔业管理模式。它是在总可捕量基础上发展起来的,并在冰岛、 新西兰等国家得以成功实施。该制度具有专属性、 可转让性、 激励性等外在法律特征。学者对于配额制度的法律特性持不同观点,认同其准物权的特性是主流观点。资源的生物特性以及制度的实质内涵告诉我们,无论是国际配额还是国内配额,制度要想取得实效,必须牢牢遵循不得超越总可捕量的共同义务这一要旨,通过落实有限准入、 加强监管等多种手段来保障这种共同义务的履行,才能实现资源的永续利用。     

Behavioral frequency: Relationship between conditioning and extinction

Operant conditioning data pertaining to bar pressing in rats show that (1) different schedules of reinforcement during training lead to differential behavior during extinction as measured by number of responses, but not as measured by number of response units and (2) animals show a response frequency/unit of time which is directly proportional to the response frequency/unit of time acquired during training.     

Origin of Metazoa: Sponges as Living Fossils

Geodia cydonium  , which code for proteins. The analyses of their deduced amino acid sequences allowed a molecular biological approach to solve the problem of monophyly of Metazoa. Molecules of the extracellular matrix/basal lamina, with the integrin receptor, fibronectin, and galectin as prominent examples, cell-surface receptors (tyrosine kinase receptor), elements of sensory systems (crystallin, metabotropic glutamate receptor), and homologs/modules of an immune system (immunoglobulin like molecules, scavenger receptor cysteine-rich, and short consensus repeats, rhesus system) classify the Porifera as true Metazoa. As living fossils, provided with simple, primordial molecules allowing cell-cell and cell-matrix adhesion as well as processes of signal transduction as known in a more complex manner from higher Metazoa, they also show peculiarities not known in other metazoan phyla. Tissues of sponges are rich in telomerase activity, suggesting a high plasticity in the determination of cell lineages. It is concluded that molecular biological studies with sponges as model will not only help to understand the evolution of Protoctista to Metazoa but also the complex, hierarchial regulatory network of cells in higher Metazoa.