Controlled imbibition in a porous medium from a soft wet material (poultice).

We provide a first approach of the mechanisms of liquid imbibition in a porous medium from a wet paste in contact with this substrate. Through Magnetic Resonance Imaging (MRI) we first show that, in contrast with intuition, the liquid can invade the substrate even if it has a larger pore size than the paste, which induces a lower capillary pressure in the substrate. This phenomenon happens because the paste can easily shrink. We then show that the imbibition stops when the capillary pressure in the substrate balances the stress needed to further contract the paste. The dynamics of the process then mainly results from the competition of these two effects plus the pressure gradient associated with the liquid flow through the paste. This in particular shows that the liquid penetration in a porous medium, from a poultice in contact with this medium, may be controlled by adjusting the poultice characteristics.

Characterization of the surface physico-chemistry of plasticized PVC used in blood bag and infusion tubing.

Commercial infusion tubing and blood storage devices (tubing, blood and platelets bags) made of plasticized PVC were analyzed by spectroscopic, chromatographic and microscopic techniques in order to identify and quantify the additives added to the polymer (lubricants, thermal stabilizers, plasticizers) and to put into evidence their blooming onto the surface of the devices. For all the samples, deposits were observed on the surface but with different kinds of morphologies. Ethylene bis amide lubricant and metallic stearate stabilizers were implicated in the formation of these layers. In contact with aqueous media, these insoluble deposits were damaged, suggesting a possible particulate contamination of the infused solutions.

Increasing leptin level in abstaining alcohol-dependent women.

INTRODUCTION: Leptin, hormone secreted by the fat tissue, changes the signaling of dopamine in the nucleus accumbens, which directly affects the sensitivity of reward and modulation of abstinence. AIMS: To evaluate the level of serum leptin and its relation to nutritional status among alcoholic abstainers and non-abstinent. METHODS: Patients of both sexes, over 18 years old and who used alcohol as their primary drug were included in the study. Abstaining patients were separated according to the time without the use of the drug as A2 (1-3 month-abstainers) and A3 (4 month and over-abstainers). Waist circumference (WC), body fat percentage (%BF) and weight and height were measured to calculate Body Mass Index (BMI). Blood samples were collected for leptin measurement. RESULTS: Mean levels of leptin, leptin/BMI, leptin/%BF were higher in all women categories. Abstaining women (A2) also showed higher leptin, leptin/BMI and leptin/ %BF than non-abstinent (p = 0.039; p = 0.023; p = 0.023). Statistical differences were also shown among abstaining women A2 and A3 as well a significant positive association between leptin levels and BMI and leptin and WC in active female drinkers (leptin × BMI: r = 0.91; p < 0.01; leptin × WC: r = 0.87; p = 0.001). However, a significant association was not shown among these results in abstaining women (leptin × BMI: r = 0.28; p = 0.37/ leptin × WC: r = -0.32, p = 0.92). CONCLUSION: Our results suggest that leptin levels seem to increase only in abstaining women. This result can be related to the length of abstinence.

The crack tip: a nanolab for studying confined liquids.

We study the equilibrium properties of a liquid phase condensed at the nanoscale between the surfaces of a sharp crack in fused silica in a moist controlled atmosphere. The extension of the condensed phase along the fracture is measured by in situ atomic force microscopy phase imaging and it is shown to be determined by a critical distance between the opposite crack surfaces, which is an increasing function of humidity. The present technique is very promising for measuring the properties of confined liquids at the nanoscale as well as for modeling the physics and chemistry of slow crack propagation in glasses.

Glass breaks like metal, but at the nanometer scale.

We report in situ atomic force microscopy experiments which reveal the presence of nanoscale damage cavities ahead of a stress-corrosion crack tip in glass. Their presence might explain the departure from linear elasticity observed in the vicinity of a crack tip in glass. Such a ductile fracture mechanism, widely observed in the case of metallic materials at the micrometer scale, might be also at the origin of the striking similarity of the morphologies of fracture surfaces of glass and metallic alloys at different length scales.

An outbreak of Staphylococcus aureus strains with reduced susceptibility to glycopeptides in a French general hospital.

We describe the isolation of Staphylococcus aureus isolates with glycopeptide heteroresistant subpopulation from 15 patients (11 with colonizations and 4 with infections) in a French hospital. Non of the patients were previously treated with glycopeptides. The 15 isolates belonged to 2 different pulsotypes unrelated to other methicillin-resistant S. aureus isolates from the same hospital.

[Alexithymia. Evaluation, quantitative and clinical data]. / L'alexithymie. Evaluation, données quantitatives et cliniques.

Alexithymia is a concept created by Sifneos in 1972 to describe a disturbance in affective and cognitive functions characterised by an inability to find words to describe feelings or emotions. The term "alexithymia" is derived from the Greek and means "no words for feelings". The salient clinical features of alexithymia include difficulties recognizing and verbalizing feelings, endless description of physical symptoms instead of emotions, concrete speech and thougth closely tied to external events, paucity of fantasy life. Precisely, alexithymia is an inability to associate one's visual image, thoughts and fantasies with a specific emotional state. For Sifneos, "emotions" and "feelings" are different facts. He differentiates "visceral emotions" (biologic side of the affect and lying in structures of the limbic system as the hippocampus and the amygdaloid complex) and "feelings emotions" (psychologic side of the affect). For him, animals experience "visceral emotion", but only human experience "feeling emotions". Alexithymia is regarded as one of several possible risk factors that seem to increase the susceptibility to physical disease. Alexithymia describes some psychological features which has been initially described by Marty and Psychosomatic French School: a specific cognitive style characterized by a lack of absence of fantasies and a preoccupation with the minute details of external events ("pensée opératoire"). Alexithymia is a difficult concept to operationalize and only few instruments are sufficiently reliable and valid. Several scales are used to measure alexithymia but only the Beth Israel Questionnaire (BIQ) and the Toronto Alexithymie Scale (TAS) can be regarded as having sufficient psychometric properties. The first questionnaire, the BIQ--a scale created by Sifneos--, is the most widely used instrument which is a 17-items forced-choice questionnaire completed by the interviewer. The TAS is a 26-items self-report measure rated on a five-point Likert scale. The Shalling Sifneos Psychosomatic Scale (SSPS) and the M.M.P.I. Alexithymia Scale lack of validation and reliability. Furthermore the SSPS and the MMPI AS show little or no relation with BIQ or with TAS, thus limiting the comparability and generalizability of results from the studies that use them. The TAS is considered as internally consistent and to have a stable, replicable factor structure. Other measures as content analysis test, projective test (Rorschach, T.AT., SAT9) or others self-assessment questionnaires are not frequently used.(ABSTRACT TRUNCATED AT 400 WORDS)