Des Plaies pénétrantes des articulations, par le Dr Dechaux,...

Contient une table des matièresAvec mode text

Ultrafast Crystallization Dynamics at an Organic–Inorganic Interface Revealed in Real Time by Grazing Incidence Fast Atom Diffraction

The poor structural properties of organic–inorganic interfaces and their variability represent the main cause of device under-performance. Understanding and controlling the development of these properties in real time has been a difficult experimental challenge. Using a recent technique based on grazing incidence fast atom diffraction (GIFAD), we were able to directly observe during deposition structural transitions in a perylene monolayer on Ag(110). Crystallization from the liquid phase occurs into two distinct structures with drastically different dynamics. Transition to the most compact packing occurs by self-organization only after a second layer has started to build up; subsequent incorporation of molecules from second to first layer triggers an ultrafast crystallization on a macroscopic sale. The final compact crystalline structure shows a long-range order and superior stability, which opens good perspectives for producing in a controlled manner highly ordered hybrid interfaces for photovoltaics and molecular electronics

Recovery of plasma volume after 1 week of exposure at 4,350 m

Ecole Nationale de Ski et D'Alpinisme, BP 24, 74401 Chamonix, France. [email protected] Plasma volume (PV) decreases at high altitude, but is rapidly restored upon return to sea-level (RSL). The aim of this study was (1) to describe PV recovery upon RSL with concomitant changes in major fluid regulating hormones, and (2) to test the hypothesis that PV recovery is promoted by the administration of a plasma expander. Ten male subjects were evaluated at rest and during submaximal exercise at sea-level (SL), after 7 days at 4,350 m (H7), and on RSL, on day 1 (RSL1, rest only) and day 2 (RSL2). PV (measured by carbon monoxide rebreathing), plasma renin (Ren), aldosterone (Aldo), atrial natriuretic factor (ANF) and arginine vasopressin (AVP) were measured at rest and during exercise. The subjects were divided into two groups 1 h before RSL, one group receiving PV expansion (475+/-219 ml) to ensure normovolemia (PVX, n=6), the others serving as controls (Control, n=4). PV decreased by 13.6% in H7 ( n=10), but was restored in RSL2, regardless of PVX. Ren, Aldo and AVP, which were similar in both groups, were reduced in H7, but were higher in RSL2 (rest or exercise). ANF was modified neither by hypoxia nor by PVX. Total water intake was reduced in H7, but remained normal in RSL in both groups, whereas water output dropped in RSL. PVX increased urine flow rate in RSL1 compared with subjects not given PVX. The present results suggest that PV recovery during early RSL is mainly due to a decreased diuresis, promoted at least in part by changes in fluid regulating hormones. However, neither PV recovery, nor hormonal responses were altered with PVX-induced normovolemia upon RSL

Inpatient target discharge weight for early-onset anorexia nervosa: Restoring premorbid BMI percentile to improve height prognosis

International audienceObjective: Early-onset anorexia nervosa (EO-AN) is characterized by restricted food intake leading to low body weight, emerging before 14 years old. Most patients reaching a target body mass index (BMI) around the 25th percentile at hospitalization discharge display an incomplete prospective height catch-up. A better understanding of height prognosis determinants is required. Methods: In 74 children with an EO-AN, we collected height and weight premorbidly, at hospitalization, and at discharge, 6 months, 12 months, and at longer-term follow-up of 36 months. We defined a height prognosis parameter (HPP) as the difference between the height percentile at follow-up times and the premorbid height percentile. We explored the relationship between weight parameters and height catch-up at follow-up with linear regression analyses. Results: A higher weight suppression (WS) - i.e., difference between premorbid and current BMI - at admission and discharge was associated with lower HPP - i.e., a greater loss of height - at 12 months and 36 months follow-up. Similarly, a higher premorbid BMI percentile was associated with a lower HPP at 12 and 36 months. Conclusion: Target discharge weight for EO-AN patients should be tailored and based on premorbid BMI trajectory to improve height prognosis