Follicular fluid and blood levels of persistent organic pollutants and reproductive outcomes among women undergoing assisted reproductive technologies

Persistent organic pollutants (POPs) are industrial chemicals resistant to degradation and have been shown to have adverse effects on reproductive health in wildlife and humans. Although regulations have reduced their levels, they are still ubiquitously present and pose a global concern. Here, we studied a cohort of 185 women aged 21-43 years with a median of 2 years of infertility who were seeking assisted reproductive technology (ART) treatment at the Carl von Linne Clinic in Uppsala, Sweden. We analyzed the levels of 9 organochlorine pesticides (OCPs), 10 polychlorinated biphenyls (PCBs), 3 polybrominated diphenyl ethers (PBDEs), and 8 perfluoroalkyl substances (PFASs) in the blood and follicular fluid (FF) samples collected during ovum pick-up. Impact of age on chemical transfer from blood to FF was analyzed. Associations of chemicals, both individually and as a mixture, to 10 ART endpoints were investigated using linear, logistic, and weighted quantile sum regression, adjusted for age, body mass index, parity, fatty fish intake and cause of infertility. Out of the 30 chemicals, 20 were detected in more than half of the blood samples and 15 in FF. Chemical transfer from blood to FF increased with age. Chemical groups in blood crossed the blood-follicle barrier at different rates: OCPs > PCBs > PFASs. Hexachlorobenzene, an OCP, was associated with lower anti-Miillerian hormone, clinical pregnancy, and live birth. PCBs and PFASs were associated with higher antral follicle count and ovarian response as measured by ovarian sensitivity index, but also with lower embryo quality. As a mixture, similar findings were seen for the sum of PCBs and PFASs. Our results suggest that age plays a role in the chemical transfer from blood to FF and that exposure to POPs significantly associates with ART outcomes. We strongly encourage further studies to elucidate the underlying mechanisms of reproductive effects of POPs in humans

New Materials in the Design and Manufacturing of Hot Structures for Aircraft Engines – Allvac 718Plus

Several efforts have been made to develop an alloy with the same versatility as the most common superalloy, Alloy 718, but with an ability to meet operating requirements for aircraft engine parts at 50 \ubaC higher temperature, i.e. 700 \ubaC. None of these alloy development efforts have been very successful for various reasons. Today a new promising alloy, Allvac 718Plus, has emerged as result of a joint effort between metal producers and aircraft engine companies. The weldability of this new alloy was examined in comparison with that of alloy 718 both by normal Varestraint and by Tranvarestraint testing. The results indicate that the weldability of 718Plus is at par with alloy 718 which also makes this alloy an interesting candidate for the Volvo Aero assembly type hot structural parts. However, the alloy must be offered in form of sheet material and as castings before the full potential can be used in such structures

Severe gastritis in guinea-pigs infected with Helicobacter pylori

Journal of Medical Microbiology47121123-1129JMMI