Volatile tritiated organic acids in stack effluents and in air surrounding contaminated materials

A small fraction of the tritium released into the atmosphere from tritium-handling or solid waste storage facilities was shown to be in the form of volatile organic acids. The same compounds were also found, but at a much higher proportion, in the tritium evolved at room temperature from highly contaminated materials placed under air atmospheres. This might be due to the oxidation and labeling of hydrocarbon(s) by mechanisms that are presumably of a radiolytic nature. The new forms could have an impact on operational requirements and waste management strategies within a tritium facility and a fusion reactor hall. Further data are needed to assess the related doses.     

Status of the Closed-Cycle Dilution Refrigerator Development for Space Astrophysics

The closed-cycle dilution refrigerator for space applications is an on-going development to improve the performance of the open-cycle dilution refrigerator successfully used on the Planck mission. This solution has been considered in various projects in X-ray and far-infrared space instruments for astrophysics (ATHENA, SPICA) and in advanced studies for future CMB polarization surveys (COrE). It is shown that for sub-Kelvin applications, this refrigerator is fully competitive with some ADR-based solutions. Compared to ADR, the main advantages are (1) a stable cooling power adapted to long uninterrupted sky surveys (2) a low mass of the coldest stages (3) the absence of magnetic field. We present the current status of the development and discuss the options for the \(^{3}\) He compressor.     

Synthesis of ferroquine enantiomers: first investigation of effects of metallocenic chirality upon antimalarial activity and cytotoxicity

Ferroquine (FQ) is a new antimalarial agent with a high blood schizotoncidal activity. Previous studies on this compound were done with racemate mixtures. As FQ possesses planar chirality, pure enantiomers were obtained by enzymatic resolution in order to compare their antimalarial activities and cytotoxicities. (+)-FQ and (-)-FQ were equally active in vitro, at nanomolar concentrations. Both enantiomers were slightly less active than the racemate in vivo; cytotoxicities were similar. Actually, the racemate represents the optimal formulation. To the best of our knowledge, this is the first investigation of biological activities of compounds with metallocenic chirality.     

Prognostic sperm factors in intra-uterine insemination with partner's sperm

We studied the prognostic value of sperm characteristics for the outcome of intra-uterine insemination with partner sperm (IUIPS). A total of 712 cycles of IUIPS following induction of ovulation with gonadotrophin (hMG/hCG) for 277 sterile couples attending the assisted reproductive technology centre of Poissy Hospital (78300-France) between January 1991 and December 1994 was studied retrospectively. Ninety-two clinical pregnancies were obtained giving an overall rate of 12.9% per cycle. None of the characteristics of the sperm as assessed initially correlated with outcome. In contrast, the number of motile spermatozoa given (n) affected outcome: for n < 1 x 10(6) the pregnancy rate was 2%; for n = 5 to 8 x 10(6) the rate was 19%. However, for +/- 8 x 10(6) the proportion of biochemical pregnancies and miscarriages was 40% which was significantly higher than for smaller concentration. The resort of IVF following 4 IUIPS failures leads to a pregnancy rate per cycle of only 6.7%.     

Effects of exposure to halogenated organic compounds combined with dietary restrictions on the antioxidant defense system in herring gull chicks

The Herring gull (HG) (Larus argentatus) is naturally exposed to halogenated organic compounds such as polychlorinated biphenyls (PCBs) through its diet. During periods of food scarcity, arctic seabirds experience lipid mobilization, allowing stored lipid soluble contaminants to re-enter the body circulation. In the present study, we investigated the effects of PCB exposure and fasting on the antioxidant defense system in HG chicks. Forty newly hatched chicks were exposed to contaminated cod liver oil for 6 weeks and then fasted for 1 week. We assessed the hepatic total oxyradical scavenging capacity (TOSC) against peroxynitrite, hydroxyl and peroxyl radicals, and measured glutathione (reduced: GSH, and oxidized: GSSG) levels and the enzymatic activities of catalase, glutathione peroxidase, glutathione reductase and superoxide dismutase. The results show that fasting significantly increased the HOC levels in the HG chick livers. Limited effects were observed on antioxidant responses; significant effects were only found for catalase (CAT) activity, Se-dependent GPX activity and the GSH/GSSG ratio in the exposed and fasted group. CAT and Se-dependent GPX activities correlated negatively with the PCB concentrations within this group, and a nonlinear relationship between glutathione and contaminant levels was also found. These effects were generally not observed after exposure or fasting alone and were likely related to the high PCB levels induced by the combination of exposure and fasting.