Spray cast Al-Si base alloys for stiffness and fatigue strength requirements

Hypereutectic AlSiFe spray-cast alloys exhibit properties similar to those of metal-matrix composite (MMC's) : high Young's modulus and a low coefficient of thermal expansion. These physical properties can be adjusted by changing the Si content of the alloy. The refinement of the microstructure is produced by formation of a large amount of nuclei in the spray. Consolidation done by extrusion (bars, tubes or profiles) and/or forging leads to high mechanical properties, especially very good dynamic properties. High fatigue properties coupled with high modulus, good high temperature behaviour and low thermal expansion, allow their use for applications in the automotive industry. In opposition to MMC's, these materials present the advantage of easy recycling and easy machinability as it is the case for the conventional AlSi alloys. The low oxygen content allows quality joining with conventional arc welding techniques

A new approach for the oocyte genotoxicity assay: adaptation of comet assay on mouse cumulus-oocyte complexes

International audienceConventional genotoxicity tests are technically difficult to apply to oocytes, and results obtained on somatic cells cannot be extrapolated to gametes. We have previously described a comet assay (original-CA) on denuded mouse oocytes, but, invivo, oocytes are not isolated from their surrounding follicular cells. Our objective was to develop a comet assay on cumulus-oocyte complexes (COC-CA) for a more physiological approach to study the genotoxicity of environmental factors on oocytes. For COC-CA, whole COC were exposed directly to exogenous agents after ovulation and removal from oviducts. Three conditions were studied: a negative control group, and two positive control groups, one of which was exposed to hydrogen peroxide (H2O2) and the other group was incubated with cerium dioxide nanoparticles (CeO2 NPs). With both tests, DNA damage was significant in the presence of both H2O2 and CeO2 NPs compared with the negative control. COC-CA offers an interesting tool for assaying the genotoxicity of environmental agents towards germinal cells. Furthermore, COC-CA is less time-consuming and simplifies the protocol of the original-CA, because COC-CA is easier to perform without the washing-out procedure

Live birth rate after female fertility preservation for cancer or haematopoietic stem cell transplantation: a systematic review and meta-analysis of the three main techniques; embryo, oocyte and ovarian tissue cryopreservation

International audienceSTUDY QUESTION What are the chances of achieving a live birth after embryo, oocyte and ovarian tissue cryopreservation (OTC) in female cancer survivors? SUMMARY ANSWER The live birth rates (LBRs) following embryo and oocyte cryopreservation are 41% and 32%, respectively, while for IVF and spontaneous LBR after tissue cryopreservation and transplantation, these rates are 21% and 33%, respectively. WHAT IS KNOWN ALREADY Currently, fertility preservation (FP) has become a major public health issue as diagnostic and therapeutic progress has made it possible to achieve an 80% survival rate in children, adolescents and young adults with cancer. In the latest ESHRE guidelines, only oocyte and embryo cryopreservation are considered as established options for FP. OTC is still considered to be an innovative method, while it is an acceptable FP technique in the American Society for Reproductive Medicine guidelines. However, given the lack of studies on long-term outcomes after FP, it is still unclear which technique offers the best chance to achieve a live birth. STUDY DESIGN, SIZE, DURATION We performed a systematic review and meta-analysis of published controlled studies. Searches were conducted from January 2004 to May 2021 in Medline, Embase and the Cochrane Library using the following search terms: cancer, stem cell transplantation, FP, embryo cryopreservation, oocyte vitrification, OTC and reproductive outcome. PARTICIPANTS/MATERIALS, SETTING, METHODS A total of 126 full-text articles were preselected from 1436 references based on the title and abstract and assessed via the Newcastle–Ottawa Quality Assessment Scale. The studies were selected, and their data were extracted by two independent reviewers according to the Cochrane methods. A fixed-effect meta-analysis was performed for outcomes with high heterogeneity. MAIN RESULTS AND THE ROLE OF CHANCE Data from 34 studies were used for this meta-analysis. Regarding cryopreserved embryos, the LBR after IVF was 41% (95% CI: 34–48, I2: 0%, fixed effect). Concerning vitrified oocytes, the LBR was 32% (95% CI: 26–39, I2: 0%, fixed effect). Finally, the LBR after IVF and the spontaneous LBR after ovarian tissue transplantation were 21% (95% CI: 15–26, I2: 0%, fixed-effect) and 33% (95% CI: 25–42, I2: 46.1%, random-effect), respectively. For all outcomes, in the sensitivity analyses, the maximum variation in the estimated percentage was 1%. LIMITATIONS, REASONS FOR CAUTION The heterogeneity of the literature prevents us from comparing these three techniques. This meta-analysis provides limited data which may help clinicians when counselling patients. WIDER IMPLICATIONS OF THE FINDINGS This study highlights the need for long-term follow-up registries to assess return rates, as well as spontaneous pregnancy rates and birth rates after FP. STUDY FUNDING/COMPETING INTEREST(S) This work was sponsored by an unrestricted grant from GEDEON RICHTER France. The authors have no competing interests to declare. REGISTRATION NUMBER CRD42021264042

No specific adverse pregnancy outcome in singleton pregnancies after assisted reproductive technology (ART) for unexplained infertility

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Étude pronostique du risque d’accouchement, des patientes hospitalisées pour menace d’accouchement prématuré, dans une maternité de niveau III

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