Search

Objective: To determine the frequency of condom breakage and understand if couple took any measure(s) to protect against pregnancy when condom breakage happened. Methods: It''s a prospective follow-up study. A total of 1 562 subjects in 9 districts of Shanghai were selected. Subjects were divided into two groups. Totally 812 subjects were in condom/emergency contraceptive pills(ECP) combined regimen group and 750 subjects were in the group of condom only. Each subject used daily diary card to record the presence or absence of menstrual bleeding or spotting, each act of sexual intercourse, condom problem, together with brief details about use of condom/postcoital ECP. The selected subjects were interviewed at the end of 1st, 3rd, 6th, 9th and 12th month after enrollment with their diary to collect information mentioned above. Results: The total condom breakage rate (CBR) of whole year was 0.53 per 1 000 condoms. The condom breakage ratio per 1 000 person months (CBRp) was 2.58. The result of multiple logistic regression showed that husbands'' age, occupation and couples'' condom using experience might affect the condom breakage. Compared with <30 years old husbands, subjects whose husbands were 30-34 years old and ≥35 years old could have higher CBR (RR=2.29, 4.07, respectively). Compared with subjects whose husbands were medical staff, subjects whose husbands were teacher and scientific technician, manager, worker and service worker could have higher risk of condom breakage (RR=3.88, 9.30, 4.00 and 8.28, respectively). Subjects with condom using experience might have lower risk of condom breakage (RR=0.44). Conclusion: The condom breakage rate was significant associated with husband''s age, husband''s occupation and condom using experience. Those might be the factors affecting the condom breakage. [Copyright &y& Elsevier]

Red-bed soft rock covers a large area in China and is often used as filling materials for highway roadbed and embankment, while the disintegration of red-bed soft rock often causes serious settlement of the roadbed and decreased stability. To thoroughly study the disintegration properties of red-bed soft rock, a series of slake durability tests were performed using different test methods. First, the gradation of disintegrated red-bed soft rock was investigated, and the shape of the gradation curve mainly presented as reverse sigmoidal and hyperbolic. Moreover, the evolution model of the disintegration breakage of red-bed soft rock using the Morgan-Mercer-Florin (MMF) model was derived, and the model parameters were analysed. Based on the test results, the disintegration behaviours of red-bed soft rock were measured by the disintegration ratio; then, the new formula to calculate the disintegration ratio based on the concept of the traditional disintegration ratio was derived using the established model. Finally, the effect of different test methods, i.e., different test devices, drying temperatures and sizes, on disintegration breakage under cyclic wetting and drying was analysed, and the test results showed that the rate of disintegration was accelerated by the slake durability apparatus, a higher drying temperature and a larger size. • The evolution model of disintegration breakage based on the Morgan-Mercer-Florin (MMF) model was derived and verified. • The effect of different test methods, i.e., different test devices, drying temperatures and sizes, on the disintegration breakage under cyclic wetting and drying was analysed. [ABSTRACT FROM AUTHOR]