Raman micro-spectroscopy can be used to investigate the developmental stage of the mouse oocyte

In recent years, the uptake of assisted reproductive techniques such as in vitro fertilisation has risen exponentially. However, there is much that is still not fully understood about the biochemical modifications that take place during the development and maturation of the oocyte. As such, it is essential to further the understanding of how oocyte manipulation during these procedures ultimately affects its developmental potential; yet, there are few methods currently available which are capable of providing a quantitative measure of oocyte quality. Raman spectroscopy enables investigation of the global biochemical profile of intact cells without the need for labelling. Here, Raman spectra were acquired from the ooplasm of mouse oocytes at various stages of development, from late pre-antral follicles, collected after in vitro maturation within their ovarian follicles and from unstimulated and stimulated ovulatory cycles. Using a combination of univariate and multivariate statistical methods, it was found that ooplasm lipid content could be used to discriminate between different stages of oocyte development. Furthermore, the spectral profiles of mature oocytes revealed that oocytes which have developed in vitro are protein-deficient when compared to in vivo grown oocytes. Finally, the ratio of two Raman peak intensities, namely 1605:1447 cm21, used as a proxy for the protein-to-lipid ratio of the ooplasm, was shown to be indicative of the oocyte’s quality. Together, results indicate that Raman spectroscopy may present an alternative analytical tool fo

Etude par coupes a basse temperature de l'espace cranio-pharyngo-mandibulaire. [A study of the cranio-pharyngo-mandibular space by sections at low temperature]

After acrylic injections into the vessels and mandibular block anaesthesia the pterygo-mandibular space is studied in 38 anatomical pieces. 538 colour slides have been obtained from anatomical cuts at low temperature with the scannigraph system. The results point out that a cranio-pharyngo-mandibular space is clearly distinguished laterally, from a medial maxillo-pharyngeal space. There is no transversal communication between them. On the contrary, the cranio-pharyngo-mandibular space communicates, forward and upward, with the temporal space; forward and downward, with the sub-mandibular space. The cranio-pharyngo-mandibular space contains an interpterygoid space communicating with the oval foramen by a "chimney" largely filled by the emissary pterygoid veins. A pericondilar plexus of veins is also observed. The cranio-pharyngo-mandibular space is characterised by the cellulo-adipose tissue by which it is filled and which guides the diffusion of injected solutions to the oval foramen

Phase Diagrams for Systems with Low Free Energy Variation: A Coupled Theory/Experiments Method Applied to Li-Graphite

The paper presents a fast and efficient method to compute phase diagrams using first-principles methods and statistical physics coupled with experimental techniques. The method is applied to lithium intercalated graphite for which evidence of experimental anomalies have recently questioned the currently accepted stage II/stage I two-phase transformation in the 0.5 ≤ x ≤ 1.0 composition range. Our coupled experimental and theoretical analysis has led to a full determination of the Li_xC_6 phase diagram in this range of composition, revealing previously unknown phase transitions and the characterization of at least two new phases