Preimplantation genetic diagnosis using FISH for carriers of Robertsonian translocations: the Portuguese experience

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.     

锅炉监控仪表的改进与实践

在原有"锅炉高低水位报警器"的基础上,研制出锅炉智能监控仪表.该仪表系统实现了自动操作、失误防护、报警及连锁保护等功能,对锅炉各类事故有积极的预防作用.     

燃煤锅炉低温烟气余热利用探讨

针对燃煤锅炉燃烧产生的低温烟气仍具有一定温度的现象,提出通过增设超导热管空气预热器对这部分低温烟气余热加以回收的设想,对锅炉送风进行预热,探讨烟气余热利用可达到的送风温度、节能效果及可能产生的经济效益。     

乌鲁木齐市采暖锅炉烟尘初始排放情况浅析

根据近几年的监测数据,对乌鲁木齐市采暖锅炉烟尘初始排放情况进行分析,并对其超标排放的原因提出了见解。     

燃煤锅炉脱硫除尘装置改造

燃煤锅炉的湿式脱硫除尘装置常因净化液管路出现故障而影响到生产,主要是因为安装在其内的陶瓷嘴受高温烟尘的影响而爆裂,通过安装结构简单、性能可靠的自控系统使装置保持连续正常工作。     

工业锅炉环境污染控讨与控制

对工业锅炉运行中造成环境污染的因素及危害进行分析,结合实际,制定了减少危害的措施。     

湿法脱硫系统优化分析

分析了运用烟塔合一等技术对现有湿法脱硫系统简化的可行性.在湿法脱硫系统中,利用冷却塔排烟气代替烟囱排烟,取消烟囱和GGH换热器,将增压风机和引风机合二为一,可提高能源的利用效率,减少设备的投资,降低系统运行及维护费用.     

BLEVE: The case of water and a historical survey

After a short update of the current more accepted definition of BLEVE, the special features of water BLEVEs are analyzed. The stronger overpressure wave generated in the case of water as compared to that of other substances is justified in terms of volume change. Through a comparison with liquefied pressurized propane, three possibilities are analyzed: the simultaneous contribution of both the liquid and the preexisting vapor, the contribution of the liquid flash vaporization, and the contribution of the pre-existing vapor. Also a historical survey on a set of 202 BLEVE accidents –the largest sample of BLEVE accidents surveyed until now– is presented. LPG was the most common substances in this set of accidents. However, water and LNG (11% of water and 4% of LNG in the studied cases) have also been involved. Impact failure (44.8%) and human factor (30.3%) were the most common causes of BLEVEs. Transport, storage, process plants, and transfer were the activities in which more accidents occurred.     

锅炉变频调速给水系统节能作用分析

变频调速在锅炉给水系统中应用，可以调节给水流量，降低能耗，减少厂用电压波动，减轻工人的劳动强度，降低操作机构的维修费用。     

锅炉温控炉拱的设计及燃烧技术性能

论述了将小型链条炉排工业锅炉的炉拱设计成在运行中可以全量调节的结构,以适应燃用多种煤种的需要,并减少与固定拱操作有关的意外伤亡事故。这项技术有创新性,适用性和推广价值