Rare uterine serosal pregnancy after in vitro fertilization in a woman with bilateral salpingectomy

Objective:To improve the understanding of ectopic pregnancy after bilateral salpingectomy through case analysis and literature review.Method:A case of uterine serosal pregnancy after in vitro fertilization and embryo transfer(IVF-ET)in a woman with bilateral salpingectomy was reported in detail and summarized,and relevant literatures searched in Pubmed were analyzed.Results:The patient had a sudden abdominal pain 18 days after transplantation.Ultrasound showed no pregnancy sac in the intrauterine cavity and bilateral adnexal areas,but there was a large amount of fluid in the Pouch of Douglas,which was an indication for surgical exploration.During the operation,the pregnancy tissue was found on the uterine serosal and cleared in time.And the patient recovered well after surgery.Review of the literatures showed that most of ectopic pregnancies after bilateral salpingectomy were treated surgically and had a good prognosis.Conclusion:Ectopic pregnancy after bilateral salpingectomy is extremely rare and should be early judged by the patients’signs.Surgical treatment timely can achieve good outcome.

Precipitate evolution in Mg-7Gd-3Y-1Nd-1Zn-0.5Zr alloy during isothermal ageing at 240 ℃

The morphology and crystal structure of the precipitates in Mg-7Gd-3Y-1Nd-1Zn-0.5Zr alloy during isothermal ageing at 240 ℃ were investigated using transmission electron microscopy (TEM) and high-angle annular dark- eld scanning transmission electron microscopy (HAADF-STEM). After under-ageing for 2 h, the precipitates in the alloy are ordered solute clusters with rare earth atomic columns exhibiting hexagonal ring structure, zigzag GP zones and β' in its early formation. After peak-ageing for 18 h, the precipitates are mainly β' and new rod-like β'p accompanied with β'. After over-ageing for 100 h, the precipitates are β',β1, long-period stacking ordered (LPSO) building block known as γ′ and 14H-LPSO.β' has the three-dimensional shape of convex lens with smaller length-to-width ratio viewed along <0001>α than that in the EW75 alloy. The excellent thermal stability of this alloy can be attributed to the γ' and 14H-LPSO retarding the growth of β' and β1, low diffusion rate of rare earth atoms and physical character of β' and β1.

Changes of microstructure of different quench sensitivity 7,000 aluminum alloy after end quenching

The quench sensitivity and their influential factors of 7,021, 7,085, and 7,050 alloys were investigated by the end quenching test method and the measurement of electrical conductivity, hardness, and microstructure after aging. The results indicate that 7,050 alloy has the largest changes with hardness decreasing from HV 199 to HV 167,and electrical conductivity increases from 16.6 to18.2 MS m-1when the distance from quenched end increases from 2 to 100 mm. Alloys 7,085 and 7,021 have relatively smaller changes. According to the relationship between the hardness and electrical conductivity of a supersaturated solid solution, 7,050 alloy has higher quench sensitivity than 7,085 and 7,021 alloys. The microstructure of 7,050 alloy with higher major alloy element（Zn ？ Mg ？ Cu） addition and Cu element addition is mostly affected by the changes of distance from quenched end. In 7,050 alloy, the size of intragranular precipitates is from about 10-200 nm, and the（sub） grain boundary precipitates are about 20-300 nm. Alloy 7,085 with lower Cu content is moderately affected, while 7,021 is least affected. It is found that with the increase of distance from quenched end, quenched-induced precipitate preferentially nucleates and grows in the（sub） grain boundary and then on the pre-existing Al3 Zr particles.