Mise au point: cancer du sein et grossesse. Revue de la littérature.

The pregnancy-associated breast cancer seems to have become increasingly common with a high frequency of advanced breast cancer with axillary node metastases and so associated with poor prognosis.English AbstractJournal ArticleReviewSCOPUS: re.jinfo:eu-repo/semantics/publishe

Investigation of the flow establishment of pre-combustion shock trains in a shock tunnel

This work is a fundamental investigation of the behavior of precombustion shock trains in the T4 Stalker Tube at the upper end of the dual-mode combustion regime. Experiments were conducted at a condition that represents flight at Mach 8 at an altitude of 26 km. The test model was a simple axisymmetric duct comprising a short diffuser, an isolator (length/diameter = 4.1), and a constant-area combustor (length/diameter = 15.7). Gaseous hydrogen was used as the fuel and was injected via six portholes equispaced around the perimeter of the duct. Time histories of the surface pressure in the model showed a pressure rise from stable supersonic combustion up to a fuel equivalence ratio of 0.9. At higher fuel levels, a precombustion shock train formed upstream of the point of fuel injection. Between equivalence ratios of 0.9 and 1.1, the shock train established itself and remained stable over a significant portion of the approximately 3 ms test window. Above an equivalence ratio of 1.1, the pressure time histories continued to rise throughout the test window and a stable flow was not established. These results indicate that short-duration facilities like the T4 Stalker Tube can be used for dual-mode combustion studies at fuel levels below a limit that will depend on the particular flow condition and model geometry

Soil Chemical Insights Provided through Vibrational Spectroscopy

Vibrational spectroscopy techniques provide a powerful approach to the study of environmental materials and processes. These multifunctional analytical tools can be used to probe molecular vibrations of solid, liquid, and gaseous samples for characterizing materials, elucidating reaction mechanisms, and examining kinetic processes. Although Fourier transform infrared (FTIR) spectroscopy is the most prominent type of vibrational spectroscopy used in the field of soil science, applications of Raman spectroscopy to study environmental samples continue to increase. The ability of FTIR and Raman spectroscopies to provide complementary information for organic and inorganic materials makes them ideal approaches for soil science research. In addition, the ability to conduct in situ, real time, vibrational spectroscopy experiments to probe biogeochemical processes at mineral interfaces offers unique and versatile methodologies for revealing a myriad of soil chemical phenomena. This review provides a comprehensive overview of vibrational spectroscopy techniques and highlights many of the applications of their use in soil chemistry research