Mesoderm induction by transforming growth factor β: Medium conditioned by TGF-β-treated ectoderm enhances the inducing activity

Dedicated to Professor Dr. Tuneo Yamada on the occasion of his 80th birthday.     

In vitro characteristics of human fetal cells obtained from chorionic villus sampling and amniocentesis

In vitro characteristics of human fetal cells have been investigated after chorionic villus sampling at the first trimester and amniocentesis at the second trimester of pregnancy. Light microscopy revealed heterogeneous morphology of cell types in both the chorionic villus culture and the amniotic fluid cultures. Based on the experiments performed, chorionic villus cells are more sensitive to pronase, trypsin, and versene during subculture and have a higher DNA content per single cell and release more [¹²⁵I]-Beta-human chorionic gonadotropin into culture medium than those found in amniotic fluid cells. The practical applications of this study are discussed.     

云南省利用水泥回转窑处置危险废物的前景

利用独特的设备和水泥窑的工艺特点,用废物代替水泥生产中的原材料,合理处置危险废物,使环境治理和循环经济达到有效的结合,是一项废物处理和资源化的新途径,是水泥生产企业可持续发展的方向之一,具有广阔的发展前景。     

关于高矿化度矿井水对生态环境的影响及防治对策

1 矿区概况 永夏矿区属华北晚古生界聚煤区,含煤地层主要为石炭二迭系。 区内地下水发育,按其岩性、地质年代及富水性,可分为第四系孔隙潜水、第三系孔隙承压力、上二迭裂隙承压水、上石炭系岩溶高承压水及奥陶系岩溶高承压水等五个含水层。第四系浅层地下水分布广泛,沉积稳定,富水性较强,渗透性能好。水位埋     

高邮市基本农田环境质量监测与评价

根据近两年高邮市试点工作经验，介绍基本农田分等定级的环境监测与评价方法，认为积极开展农田环境监测并进行科学评价是基本农田保护的重要工作内容。     

用煤矸石制取水玻璃的研究

本文研究了用煤矸石制取水玻璃的可行性，利用正交试验，研究了焙烧温度、焙烧时间、反应温度、ＮａＯＨ浓度、渣样粒度等因素对制取过程的影响，确定了最佳操作条件。     

Vitamins,folic acid and neural tube defects: Comments on investigations in the United States

No clear answer concerning whether multivitamin/folate supplementation prevents neural tube defects (NTDs) is provided by three studies in the United States. All these studies are occurrence in nature, no recurrence studies having been conducted. The Atlanta Birth Defects Study is subject to pronounced memory and recall biases, the length between event and interview being as long as 16 years. In a second study (Boston University), objections can be raised to certain aspects of the experimental design, and the claim that 22 per cent of women started vitamins sufficiently early after pregnancy diagnosis to influence NTD formation is suspicious. Our NICHD case control study of 541 women in California and Illinois revealed no evidence for multivitamins or folic acid preventing NTDs. U.S. public policy-makers face difficulties in applying results of recurrence or occurrence studies in high-risk areas to low-risk areas in the U.S.