Prospective intervention trial of a screening protocol to identify fetal trisomy 18 using maternal serum alpha-fetoprotein,unconjugated oestriol,and human chorionic gonadotropin

Two prenatal centres in New England, routinely using a screening protocol for fetal Down syndrome that included maternal serum alpha-fetoprotein (AFP), unconjugated oestriol (uE3), and human chorionic gonadotropin (hCG) measurements in combination with maternal age, adopted a separate screening protocol for trisomy 18. That protocol identified a pregnancy as being at high risk when AFP, uE3, and hCG measurements all fell at or below specified cut-offs (0.75, 0.60, and 0.55 multiples of the median, respectively), regardless of maternal age. Among the first 19 491 women screened, 98 (0.5 per cent) were found to have values which placed them in the high-risk category. Four of these women were subsequently found not to be pregnant. In two others, samples from non-pregnant individuals were found to have been incorrectly submitted for analysis in place of the samples from the pregnant women. All of the remaining 92 women were counselled and offered amniocentesis and fetal karyotyping. Eighty-eight (96 per cent) accepted. Karyotypes or birth outcomes were available on all 92 pregnancies. Six cases of trisomy 18 and one case of Turner syndrome were identified by karyotype. One case of trisomy 18 was identified for every 14 unaffected pregnancies offered amniocentesis. In the present prospective study, an estimated 85 per cent of the cases of trisomy 18 were identified. However, given the small number ofcases (six), the 95 per cent confidence interval for the detection rate is broad (40–95 per cent).     

蒙德评价法在硫化氢储罐区的应用

采用英国帝国化学公司(ICI)蒙德火灾爆炸毒性指数评价方法分析了硫化氢储罐区的潜在危险性,对储罐区采取安全措施前后的火灾、爆炸、中毒等危险进行预测,从硫化氢储罐区的安全管理和消防措施等方面提出了对策.     

铬天青S分光光度法测定痕量铝的研究

研究了铝-铬天青S（GAS）-溴化十六烷基吡啶（CPB）分光光度法测定水样中痕量铝的最佳实验条件。结果表明：铝-铬天青S（GAS）-溴化十六烷基吡啶（CPB）三元显色体系的最大吸收波长为640nm；．最佳显色时间30min；显色剂铬天青S（GAS）最佳用量2．00mL（0．5g／L）；最佳显色pH5．5。在实验确定的最佳条件下，测定结果有较好的稳定性，较高的准确度。     

1,2,4-三氯苯降解菌的分离及其降解质粒的研究

 以1,2,4-三氯苯为唯一碳源,从天津化工厂氯苯生产车间的土壤中分离到1株1,2,4-三氯苯的降解菌THSL-1.通过形态观察和16SrDNA序列测定,该菌株被初步鉴定为施氏假单胞菌(Pseudomonasstutzeri).经质粒检测,在菌株THSL-1中发现1条质粒条带,将所获得质粒转化到E.coli.JM109中,转化子能以1,2,4-三氯苯为唯一碳源生长,且对1,2,4-三氯苯有降解作用.因此,可以认为该质粒携带降解1,2,4-三氯苯的基因.选用HindIII、BamHI、XholI3种限制性内切酶分别对质粒pTHSL-1进行单酶切、双酶切,最终确定质粒平均大小为40.2kb.     

环境保护图书网络管理系统的开发及应用

在多年环保图书管理工作的基础上，自主研发了一套图书网络管理系统，该系统基于ASP VBScript语言开发，采用B／S结构设计模型，适合于中小型企事业单位局域网的图书自动化管理。     

体态语言在图书馆读者服务工作中的应用

本文从体态语言对图书馆读者服务工作的影响层面切入,解读了什么是体态语言,并详细介绍了在读者服务工作中应如何运用体态语言和提高运用的途径     

硫化氢废气净化进展

综合论述了目前对H2S废气净化的多种方法并加以比较，指出了适用范围。此外，还是出用废物制取脱硫剂的研究方向，该法制取的脱硫剂稳定性好，脱硫效率高，制取方便且成本低，是对H2S废气净化及废物综合利用的新方法。     

Rapid prenatal diagnosis of trisomy 18 and triploidy in interphase nuclei of uncultured amniocytes by non-radioactive in situ hybridization

Two biotinylated chromosome-specific DNA probes were used to quantify the number of chromosomes 18 and 1 in uncultured amniocytes. Thirty-three samples of uncultured amniocytes were hybridized with a chromosome 18-specific DNA probe. Uncultured cells from two of the 33 samples were also hybridized with a chromosome 1-specific probe. Thirty of the samples were disomic with respect to chromosome 18; two samples were trisomic with respect to chromosome 18, and one sample was trisomic with respect to chromosomes 1 and 18. The two cases of trisomy 18 and the single case of triploidy were identified on uncultured celis within 48-72 h after amniocentesis. They were found among five samples from pregnant women who had amniocentesis because of an ultrasonographically identified fetal malformation. A trisomic karyotype could be diagnosed with certainty in uncultured amniocytes because the majority of the responding nuclei exhibited three hybridization signals. In normal cells, the majority of nuclei exhibited two signals. In no cases was there discordance between the genotype as predicted by in situ hybridization and that determined by cytogenetic analysis.     

Umbilical cord pseudocyst in trisomy 18

Prenatal diagnosis of cord defects by means of ultrasound examination is possible and highly accurate. Although this is a rare pathological finding, we report two cases in which umbilical cord pseudocysts were associated with trisomy 18. These observations underscore the need of umbilical blood sampling for establishing the karyotype in fetuses with such umbilical cord anomalies and the importance of careful examination of placentas and infants born with such defects.     

镍、锌、铝对羊角月芽藻(Selenastrum capricornutum)生长及酶活性影响研究

研究了不同浓度镍、锌、铝对常见绿藻羊角月芽藻（Ｓ．ｃａｐｒｉｃｏｒｎｕｔｕｍ）生长速度、蛋白质含量、ＡＴＰ水平、葡萄糖－６－磷酸脱氢酶（Ｇ６ＰＤＨ）、酸性磷酸酶及硝酸还原酶活性的影响．结果表明３种金属离子在所试浓度范围内对羊角月芽藻的生长速度均有抑制作用，但单位藻培养物中蛋白质含量却随着金属离子浓度的增加而增加；高浓度金属离子对酶活性有明显抑制作用；藻细胞中ＡＴＰ水平随着金属离子浓度的增加而下降．提出金属离子对藻类生物产生影响的机理可能是：高浓度金属离子的存在，打破了生物最佳的各种营养元素生物可利用性的平衡．并讨论了藻类生长及生化活性对金属离子反应的相关性．