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Atomically precise ultradoping of silicon is possible with atomic resists, area-selective surface chemistry, and a limited set of hydride and halide precursor molecules, in a process known as atomic precision advanced manufacturing (APAM). It is desirable to expand this set of precursors to include dopants with organic functional groups and here we consider aluminium alkyls, to expand the applicability of APAM. We explore the impurity content and selectivity that results from using trimethyl aluminium and triethyl aluminium precursors on Si(001) to ultradope with aluminium through a hydrogen mask. Comparison of the methylated and ethylated precursors helps us understand the impact of hydrocarbon ligand selection on incorporation surface chemistry. Combining scanning tunneling microscopy and density functional theory calculations, we assess the limitations of both classes of precursor and extract general principles relevant to each.

IntroductionItaly has been one of the most affected countries by Covid-19 pandemic. Our University General Hospital, Policlinico of “Tor Vergata” (PTV) in Rome, has become a Covid Hub in order to manage the spread of the epidemic. Thus, our Psychiatric Emergency Service (PES)’s access has been partially limited. Direct indicators of PES activity, as admission rates, can be useful for evaluating the psychological impact of Covid epidemic.ObjectivesTo assess psychiatric admittance rates to PES of PTV before and during Covid-19 global pandemic.MethodsData from our PES register have been obtained and analyzed. We compared all the psychiatric access during the trimester March – May 2019 and 2020. All patients have been characterized according to clinical features.ResultsA marked reduction of the number of patients presenting to PES has been observed (76 patients) in the 57-day period (March 11–May 04, 2020) of lockdown compared to the same period in 2019 (266 patients). The cutback was visible for all diagnostic groups, except for “Borderline Personality Disorder” diagnosis which have slightly increased. On the other hand, hospitalization rates in our psychiatric inpatients unit remained steady.ConclusionsAlthough larger study are needed to understand the mental consequences of the lockdown experience, people’s fear of potential infection might explain our results. Interestingly, personality disorder patients represent an exception to it, suggesting the importance of the clinical characteristics of fearless, engagement in dangerous behavior and detachment from reality. These findings might be helpful to improve psychosocial crisis interventions during the pandemic.

In a first section, Marangoni convection induced by a temperature gradient is studied around a single air bubble. The bubble is introduced under a downward facing heating element into a liquid layer heated from upper and cooled from below (silicone oils Pr = 16.7 and Pr = 228 or FC-72, Pr = 12.3). In this configuration stationary thermocapillary convection can be followed by the oscillatory convection. Firstly the 3D oscillatory thermocapillary convection is presented for a silicone oil (Pr = 16.7). Then, the critical threshold between the stationary state and the first oscillatory mode is determined. The influence of the liquid kind on this threshold is presented for one layer height. Moreover, other parameters (horizontal wall temperature, layer height) are tested for one liquid. At least, we consider heat transfer induced by this convection, and we discuss the results versus the convection state. The second section of this paper concerns preliminary results on Marangoni convection with boiling around a single vapor bubble growing under a downward facing heating element into a subcooled liquid (FC-72). The oscillatory thermocapillary convection is observed. It occurs during the growth from a critical bubble radius. The influence of the subcooling level on its occurrence threshold is shown.

Four-week-old Swiss male mice were placed 20 cm from a color television screen switched on for 5 continuous days/week, 9 ± 2 h/Day for 106 days. The control group was nonexposed. The average magnetic field was 0.8 μT at the front of the exposed mice cage, and 0.23 μT at the back. Hematologic and cortisol values were measured on Days 0, 22, 57, and 106. Statistical analysis on weight and hematological values were performed using analysis of variance for repeated measures involving baseline values, group, time, and interaction between group and time as fixed factors. Polymorphonuclear neutrophils were significantly lower in the exposed group than control, but no interaction between time and exposure was found. On Day 22, erythrocytes, hemoglobin, hematocrit, and mean corpuscular hemoglobin were significantly higher in the exposed group. An interaction between time and group was found. Day 57 cortisol values of the exposed group were significantly higher than control, and on Day 106, values of the exposed gr...

This is the 2nd part of a survey study conducted on 530 people (270 men, 260 women) living or not in vicinity of cellular phone base stations. Comparison of complaints frequencies for 16 Non Specific Health Symptoms was done with the CHI-Square test with Yates correction. Our results show significant increase (p 5 years), excepted for irritability significantly increased after > 5 years. Other electromagnetic factors (electrical transformers, radio-television transmitters,...) have effects on the frequency of some symptoms reported by the subjects.

Resume Une etude en aveugle a ete conduite sur 13 jeunes femmes (âge moyen < 30 ans) dont 6 travaillaient au moins 4 h/j, 5 jours par semaine, depuis plus d’un mois devant un ecran d’ordinateur. Des precautions particulieres ont ete prises dans la selection des sujets de l’experience : meme type de traitement contraceptif pour le groupe expose et non expose aux ecrans, absence de traitement psychotrope en cours, absence de decalage horaire recent, faible exposition a la television pour le groupe non expose aux ecrans d’ordinateurs. Le dosage radio-immunologique de la 6-sulfatoxymelatonine a ete pratique sur les urines recueillies au cours de la nuit chez les femmes exposees et non exposees. L’analyse des resultats (Test non parametrique des rangs de Mann-Withney) met en evidence une excretion beaucoup plus faible (– 54 %), significativement plus basse (p

Resume Les transferts thermiques induits par la convection thermocapillaire generee par une bulle d'air introduite sous une paroi chauffee dans une couche d'huile de silicone sont quantifies experimentalement sous gravite normale par mesures directes avec un fluxmetre. Une etude systematique est effectuee en fonction de la taille de la bulle et du gradient de temperature pour deux viscosites. Le regime d'ecoulement autour de la bulle (stationnaire ou oscillatoire) est determine par ombroscopie. Deux comportements de transferts de chaleur sont mis en evidence. L'existence de ces comportements est conditionnee par le nombre de Prandtl et est independante du regime d'ecoulement. Pour citer cet article : C. Reynard et al., C. R. Mecanique 331 (2003).

A survey study was conducted, using a questionnaire, on 530 people (270 men, 260 women) living or not in proximity to cellular phone base stations. Eighteen different symptoms (Non Specific Health ...

A survey study using questionnaire was conducted in 530 people (270 men, 260 women) living or not in vicinity of cellular phone base stations, on 18 Non Specific Health Symptoms. Comparisons of complaints frequencies (CHI-SQUARE test with Yates correction) in relation with distance from base station and sex, show significant (p 300 m or not exposed to base station, till 300 m for tiredness, 200 m for headache, sleep disturbance, discomfort, etc. 100 m for irritability, depression, loss of memory, dizziness, libido decrease, etc. Women significantly more often than men (p < 0.05) complained of headache, nausea, loss of appetite, sleep disturbance, depression, discomfort and visual perturbations. This first study on symptoms experienced by people living in vicinity of base stations shows that, in view of radioprotection, minimal distance of people from cellular phone base stations should not be < 300 m.

A survey study, using a questionnaire, was conducted in 161 students and workers in a French engineering school on symptoms experienced during use of digital cellular phones. A significant increase in concentration difficulties (p

Problems related to the interpretation of results and clinical consequences of analysis in Immunohematology laboratory are discussed. On the basis of an Hospital-Based HTA (HB-HTA) approach, most common errors of the analytical processes have been highlighted, divided in preanalytical, analytical and post analytical phase. For each phase, the adoption of automated instruments has enabled a strong reduction of errors, monitored by using indicators related to the analytical phases.

The 3D periodic state, following the steady thermocapillary convection state, around an air bubble immersed in a low-Prandtl-number silicone oil layer under a heated wall was experimentally investigated on the ground and during parabolic flights. This oscillation was observed under reduced gravity conditions for the first time. Consequently, the initiation of this oscillation seems to be independent of gravity and so of buoyancy convection. The reduced and increased gravity conditions showed that the gravity level modifies the oscillation. Its frequency increases with the gravity level. The comparison with the results obtained on the ground shows the bubble aspect ratio is not a relevant parameter when the gravity varies.

Resume Une etude a ete conduite au moyen d'un questionnaire, chez 83 non utilisateurs et 78 utilisateurs de telephones mobiles cellulaires de type digital. Les resultats obtenus ont ete analyses au moyen du test non parametrique du Chi-carre. Il n'est pas mis en evidence de differences significatives entre les utilisateurs et les non utilisateurs de portables pour les symptomes generaux, tels que maux de tete, difficultes de concentration, perte de memoire, fatigue et perturbations du sommeil. Dans le groupe utilisateurs de portables, il est observe des differences significatives (p

The aim of this work is to study the porosity of three-dimensional and two-dimensional packing of stiff cylindrical fibres according to their aspect ratio. First, we have carried out an experimental study of the porosity for 3D and 2D packing. In this last case, the elementary representative surfaces have been determined. Then, an attempt of interpretation of the porosity variations for 2D stacks has been realized on the basis of the excluded volume theory and a variation law has been proposed. To conclude, we have studied the relevance of a simplified packing model based on a single geometry of the defects.

This study focused on local measurements realized in the dilute zone of a CFB cold pilot. The investigations were carried out using a phase Doppler particle analyzer (PDPA). The hydrodynamic characteristics of the solid phase (size, axial and transversal velocities) were measured at different heights in the CFB riser. Temporal evolutions of the particle velocity and size were determined as well as mean values along the vertical and horizontal axis. The systematic study according to the position in the riser shows a segregation phenomenon and typical velocity profiles for this type of two-phase flow.

This study focused on the measurement of solid mass flux in the riser of a CFB cold pilot. The investigations were carried out using a Phase Doppler Particle Analyser (PDPA). Inconsistencies in PDPA results were observed when investigating flows with high particle densities. It appears that the performance of the measuring technique was affected by the optical thickness of the measured medium, thus producing substantial overestimation of the global solid phase quantity (e.g. solid mass flux). To determine the origin of these inconsistencies, the measuring system was subjected to complete recalibration. It was found that in flows with high particle densities, noisy Doppler signals tend to be split into several parts by the burst detector system, thus producing inconsistencies in the number of particles counted. The parameters associated with the splitting events were analysed, and a post-processing algorithm was developed to limit PDPA measuring errors. The aim of the post-processing algorithm was to rebuild the data and to recover the original measurements. The reconstitution process was applied to solid mass flux measurements in a CFB cold pilot.

Experimental studies have been carried out on fluid flow through porous media made up of randomly packed monodisperse fibers. The permeability and the Kozeny-Carman parameter kk are deduced from experimental results. The variations of the permeability increase exponentially with the porosity. The parameter kk is a decreasing function of the porosity ε and tends asymptotically to a value close to that deduced from a modified Ergun relation. The important decrease, observed for small aspect ratios, is certainly an effect of the cut sections of fibers. The results in terms of parameter kk are systematically compared to those deduced from various theoretical models. The variation laws of the parameter kk, deduced from different models, present important discrepancies with our experimental results.

We present the results of our analysis on the operative efficiency of the Day Hospital since it opened on 27/04/92 in the Division of Urology of ULSS 4 Parma. This study has been performed by comparing both median stays in hospital for the numerically more representative surgical operations (prostatectomy, TURP, TURV) and by using the DRG system. The DRG specific cost for every hospitalization has also been calculated. Both systems show an increase in the number of treated cases and a decrease in the average hospitalization. This positive trend has been confirmed by the analysis of the costs.

Experimental analysis of the heat transfer in an unconsolidated porous medium was conducted. A fluid flowed through the medium in an upward direction. The fluid was heated by one or both of the vertical sides. Several flow and thermal configurations were examined, single-phase and phase-change. Experimental analysis was carried out on the set of temperature values measured throughout the enclosure. All the temperatures in the medium were evaluated by using polynomial fitting from local readings. The validity of the technique is confirmed by the good correspondence, for single-phase flow, between the experimental and calculated temperatures obtained with a numerical model. In phase-change conditions, the experimental observations revealed the formation of zones. In the case of forced convection for steady-state conditions, three zones were observed and localized: a liquid-saturated zone at the bottom, a vapor zone at the top, and a phase-change zone between them. For a liquid initially at rest, these three zones were also observed during a finite time.

The interaction of a pulsed (100 and 50 Hz) magnetic field (90 μT) with the effect of atropine on small intestine transit was studied in mice. Both frequencies of the magnetic field significantly potentiated the atropine-induced delay in intestinal transit but did not affect intestinal transit per se. This result further strengthens previous observations on interactions between electromagnetic fields and the actions of drugs. © 1992 Wiley-Liss, Inc.

A buoy based instrument platform (the "O-buoy") was designed, constructed, and field tested for year-round measurement of ozone, bromine monoxide, carbon dioxide, and meteorological variables over Arctic sea ice. The O-buoy operated in an autonomous manner with daily, bi-directional data transmissions using Iridium satellite communication. The O-buoy was equipped with three power sources: primary lithium-ion battery packs, rechargeable lead acid packs, and solar panels that recharge the lead acid packs, and can fully power the O-buoy during summer operation. This system was designed to operate under the harsh conditions present in the Arctic, with minimal direct human interaction, to aid in our understanding of the atmospheric chemistry that occurs in this remote region of the world. The current design requires approximately yearly maintenance limited by the lifetime of the primary power supply. The O-buoy system was field tested in Elson Lagoon, Barrow, Alaska from February to May 2009, and here we describe the design and present preliminary data.

An experimental setup was designed to study direct-contact evaporators using a liquid dispersed in another immiscible liquid. The study was carried out on an n-pentane–water system to determine the influence of different parameters on these systems, and consequently to construct a model for this type of evaporator. An optical probe was used to measure the local void fraction. At different column abscissas along a selected diameter, the local void fraction variations were determined. The shape of the curves can be attributed to the different processes occurring in the spray column. A one-dimensional heat transfer model in the spray column was established. Simplifying assumptions were used to establish and resolve the set of equations governing heat transfer and two-phase flow. The vaporization process induces a volumetric expansion of the two-phase mixture. A theoretical model was used, in which the coalescence between the spherical fluid particles is taken into account. Different coalescence laws dependent on particle density were introduced into the theoretical model and then tested. The numerical results are discussed and compared with the experimental data obtained for the n-pentane–water system.

International audience; Liquid convective instabilities during a single vapour bubble growth in subcooled FC-72 are experimentally investigated. The bubble was created on an artificial nucleation site located on a downward facing heating element. For a non-degassed liquid, convective instabilities were observed using a shadowgraphy method and tracer particles. Both stationary and oscillatory modes were observed, and this instability was found to be Marangoni convection. Comparing results with a degassed and a non-degassed liquid, it was found that the onset of Marangoni convection was due to the presence of non-condensable gases in the liquid. Finally, the combination of Marangoni convection and condensation enables us to highlight a thermal oscillator, with a change in the type of oscillatory motion during the condensation phase.

International audience

The authors examined immunological disorders in 6 individuals who had been exposed occupationally to environmental electromagnetic fields. Comparable effects on mice exposed in a similar environment were also investigated. The human subjects had worked 8 hr/day for 5 yr in a laboratory located above electrical transformers and high-tension cables, and in which there were low-frequency electromagnetic fields of 0.2-6.6 microtesla (microT). The 6 control subjects (matched for socioeconomic parameters, sex, and age) had worked away from the immediate vicinity of transformers and high-tension cables. The authors found statistically significantly lower total lymphocyte, CD4, and CD3 counts, and significantly increased natural killer (NK) cells, in exposed subjects vs. controls. Six months after exposure had ceased, total lymphocyte counts had increased, as had CD4, CD3, and CD19 counts (+13%, +28%, +22%, and +17%, respectively), and NK cell counts were decreased by 26% (not significant) in the same human subjects. In the second part of this study, 12 Swiss male mice housed in cages were exposed in the same room in which the human subjects had been exposed (i.e., 5-microT, 50-Hz magnetic field) for 109 days; 12 additional mice were used as unexposed controls. The total lymphocyte, leukocyte, polymorphonuclear neutrophil, CD4, and NK counts of the exposed mice at 109 days were significantly lower than those of controls. In addition, plasma glucose levels (at 30 days) and amylase activity (at 109 days) were significantly lower, whereas plasma sodium and chloride levels were significantly elevated at 109 days. Results from this study suggest that chronic exposure to a 0.2-6.6-microT magnetic field can lead to decreased immunological parameters (total lymphocytes and CD4 counts) in both humans and mice. The increase in some values once exposure was terminated suggests a causal relationship with exposure to electromagnetic fields, as do the changes in mice, particularly the changes in total lymphocyte and CD4 counts.

Le present travail concerne une etude experimentale de la croissance d'une bulle de vapeur unique dans un bain de FC-72 sous refroidi a pression atmospherique. La configuration physique encore peu rencontree dans la litterature se caracterise par des effets gravitationnels stabilisants : la bulle croit sous un element chauffant (a flux parietal impose constant) a partir d'un site de nucleation artificiel indente en son centre. Une etude de la dynamique de la croissance de la bulle est effectuee a partir d'un traitement d'images permettant d'acceder a l'evolution temporelle des differents parametres geometriques associes a la bulle, tels que le diametre maximal, la hauteur, le volume, les contours. Une analyse de certains parametres permet de montrer notamment l'influence de la puissance de chauffe sur les transferts de masse et de chaleur. Par ailleurs, une observation par ombroscopie des differents modes d'instabilites convectives est presentee. L'influence de la presence d'incondensables sur le declenchement de l'instabilite est discutee.

In this paper a database of sessile drop evaporation on a heated surface under gravity conditions is presented. For this an experimental setup is presented. It includes the part which allows evaporating the drop under controlled conditions and the data acquisition system. The drop is deposited on a heated surface maintained at constant temperature. Two systems were studied: water PTFE (non wetting couple) in which the wetting angle is higher than π/2 and water‐aluminum (wetting couple) in which the wetting angle is less than π/2. Two types of measurements are implemented: the first one is an optical method which enables measurements of drop geometrical parameters and consequently the drop evaporation rate. The second one corresponds to a thermal fluxmeter. This later allows the determination of the heat flux and drop temperature. The evaporation rate as well as the geometrical parameters (contact angle, wetting diameter) are determined for several operating conditions: wall temperature and drop size for t...

Heat exchanges during boiling are of high interest for cooling systems. The objective of this work is to investigate heat transfer around a single vapor bubble, the influence of the liquid subcooling and of the heat flux applied on the nucleation surface. Experiments on subcooled pool boiling at atmospheric pressure for a single vapor bubble were conducted and the obtained results are presented. The bubble was created on a downward facing heating element. Generation of the single bubble was achieved on an artificial cavity; the indentation was made on a fluxmeter (Captec Entreprise®). FC‐72 was used as the test liquid, and its subcooling was maintained to 8 and 14K. Two heating powers were applied on the nucleation surface, and maintained constant during each experiment. Evolutions of bubble size and shape, as a function of wall superheat and liquid subcooling, were followed and studied using a 25 fps video camera. The effect of heating power and subcooling on growth periods were found to be significant. Total heat fluxes during bubble growth were measured using the fluxmeter, for different levels of subcooling and heating powers. Image and data processing has enabled us to show up influence of bubble growth on heat transfer and to determine nucleation periodicity. These preliminary results are discussed.

Routing protocols present a convergence latency for all routers to update their tables after a fault occurs and the network topology changes. During this time interval, which in the Internet has been shown to be of up to minutes, packets may be lost before reaching their destinations. In order to allow nodes to continue communicating during the convergence latency interval, we propose the use of alternative routes called detours. In this work we introduce new criteria for selecting detours based on network connectivity. Detours are chosen without the knowledge of which node or link is faulty. Highly connected components present a larger number of distinct paths, thus increasing the probability that the detour will work correctly. Experimental results were obtained with simulation on random Internet-like graphs generated with the Waxman method. Results show that the fault coverage obtained through the usage of the best detour is up to 90%. When the three best detours are considered, the fault coverage is up to 98%.

This is the 2nd part of a survey study conducted on 530 people (270 men, 260 women) living or not in vicinity of cellular phone base stations. Comparison of complaints frequencies for 16 Non Specific Health Symptoms was done with the CHI-Square test with Yates correction. Our results show significant increase (p0.05) in relation with age of subjects (elder subjects are more sensitive) and also, that the facing location is the worst position for some symptoms studied, especially for distances till 100 m from base stations. No significant difference is observed in the frequency of symptoms related to the duration of exposure (from1 year to5 years), excepted for irritability significantly increased after5 years. Other electromagnetic factors (electrical transformers, radio-television transmitters,...) have effects on the frequency of some symptoms reported by the subjects.

A survey study using questionnaire was conducted in 530 people (270 men, 260 women) living or not in vicinity of cellular phone base stations, on 18 Non Specific Health Symptoms. Comparisons of complaints frequencies (CHI-SQUARE test with Yates correction) in relation with distance from base station and sex, show significant (p0.05) increase as compared to people living300 m or not exposed to base station, till 300 m for tiredness, 200 m for headache, sleep disturbance, discomfort, etc. 100 m for irritability, depression, loss of memory, dizziness, libido decrease, etc. Women significantly more often than men (p0.05) complained of headache, nausea, loss of appetite, sleep disturbance, depression, discomfort and visual perturbations. This first study on symptoms experienced by people living in vicinity of base stations shows that, in view of radioprotection, minimal distance of people from cellular phone base stations should not be300 m.

A survey study, using questionnaire, was conducted in 161 students and workers in a French engineering school on symptoms experienced during use of digital cellular phones. A significant increase in concentration difficulty (p0.05) was reported by users of 1800-MHz (DCS) cellular phones compared to 900-MHz (GSM) phone users. In users of cellular phones, women significantly (p0.05) complained more often of sleep disturbance than men. This sex difference for sleep complaint is not observed between women and men non-users of cellular phone. The use of both cellular phones and VDT significantly (p0.05) increased concentration difficulty. Digital cellular phone users also significantly (p0.05) more often complained of discomfort, warmth, and picking on the ear during phone conversation in relation with calling duration per day and number of calls per day. The complaint of warmth on the ear might be a signal to users for stopping the call.

Space Technology and Applications International Forum (STAIF-2000), ALBUQUERQUE, NM, JAN 30-FEB 03, 2000; International audience; This paper concerns an experimental study on thermocapillary convection at the interface between an air bubble and a silicone oil with a low Prandtl number. The silicone oil layer is heated from above and cooled from below in order to obtain a vertical temperature gradient. When the temperature gradient is increased and a critical value is exceeded, oscillations appear in the liquid. This oscillatory thermocapillary convection is analyzed versus the temperature gradient and the bubble aspect ratio. A non intrusive optical measurement technique based on shadow technique is developed. Three oscillations modes are observed in a vertical section of experiment cell. The systematic study shows the influence of the temperature gradient and of the bubble size on their associated characteristic frequencies. The values obtained are close to 1 Hz.

A low-doses treatment with cuprum 4CH, 24 and 5 hr before neostigmine (50 μg/kg/IP) administration, has been done in the female mouse. This treatment significanlty reduces (Kruskal-Wallis—P < 0.02) the facilitating action of neostigmine on intestinal transit. Cuprum 4CH treatment administered alone has no significant effect on transit.

Portable cellular phones and their relay stations emit ultra-high frequency waves (microwaves) with amplitude modulation and extremely low frequency pulsation. The user is absorbed by the head and reaches the nervous structures leading to increased brain temperature. The general population is exposed to a distant field with an electromagnetic intensity which depends on the distance from the emitting antennas, the presence of "passive re-emitters", and the number of communications processed by the relay station. Among the main biological effects, "radio-frequency disease", electroencephalogram disturbances, and blood pressure disorders as well as risk of cancer have been observed in humans and animals.

It has recently become clear that the B cell antigen receptor, membrane immunoglobulin (mIg) is part of a complex composed of a number of different polypeptides. In a manner analogous to the T cell receptor, mIg has been found to be associated with several tyrosine kinases, and other proteins, which although not kinases themselves become targets of kinase activity upon binding of mIg to antigen. Thus the B cell receptor complex appears to be a structure whose function during signal transduction is to facilitate the interaction of tyrosine kinases with their proper substrates, and to coordinate the phosphorylation of these proteins with the binding of antigen to mIg. In an effort to understand the nature of the interactions which mediate the organization of the B cell receptor complex, we have explored binding of components of the complex including Ig-alpha and Ig-beta to IgM. Previous results have indicated that binding was mediated by transmembrane domains. Our results indicate that extracellular domains of IgM may also contribute to its association with Ig alpha and beta and other members of the B cell receptor complex.

Des etudes experimentales de l'ecoulement d'un fluide a travers un milieu poreux constitue de fibres monodisperses empilees aleatoirement sont realisees. Les milieux fibreux etudies ont des porosites variant de 0,35 a 0,90. Ces porosites sont obtenues a l'aide de fibres dont le rapport d'aspect L/d varie de 4 a 70. Les lois de perte de charge en fonction de la vitesse du fluide sont determinees systematiquement pour chaque milieu poreux. Une analyse detaillee est effectuee pour les faibles vitesses d'ecoulement. L'influence de la direction de l'ecoulement sur les lois de perte de charge est etudiee. Celles-ci sont etablies suivant deux directions perpendiculaires. Les resultats obtenus mettent en evidence un comportement du milieu fibreux globalement isotrope vis a vis de l'ecoulement du fluide. La permeabilite et le parametre de Kozeny Carman k k sont deduits des resultats experimentaux. Les variations de la permeabilite en fonction de la porosite suivent une loi de type exponentiel. Le parametre de Kozeny Carman k k decroit en fonction de la porosite e(L/d) et tend asymptotiquement vers une valeur proche de celle deduite de la relation d'Ergun modifiee. La decroissance importante, observee pour les petits rapports d'aspect, est sans doute due aux effets induits par les surfaces de base des fibres. Ces effets deviennent negligeables pour les grands rapports d'aspect. Les resultats en terme de permeabilite et de parametre de Kozeny Carman sont compares systematiquement avec les modeles proposes dans la litterature. Generalement, ces modeles supposent des cylindres de grande longueur, disposes en reseaux simples. L'ecoulement est soit parallele, soit perpendiculaire a l'axe des cylindres. Les lois de variation du parametre k k , deduites des differents modeles, presentent des ecarts importants avec les resultats experimentaux. Ces resultats semblent montrer qu'une disposition des fibres en reseaux simples ne permet pas une description convenable des ecoulements a travers les empilements aleatoires de fibres.

Keratosis punctata palmaris et plantaris (KPPP) of Buschke-Fischer-Brauer is an autosomal dominant genodermatosis characterized by disseminated cup-shaped horny papules with central depression containing keratotic plugs. The disease is circumscribed on the palms and soles; associated abnormalities are unusual. The microscopic findings show normal structure of the epidermis with massive orthokeratotic hyperkeratosis, hypergranulosis and acanthosis; dermis is slightly compressed below the epidermis level by the keratotic plugs and free of inflammatory infiltrates. We describe a female of 37 years old (proband) affected by KPPP and her familiar pedigree showing that dermatosis is dominantly inherited. The clinical features of KPPP are like the first reports of Brauer (keratoderma dissipatum hereditarium palmoplantare). The criteria used to diagnose and classify the hereditary palmoplantar keratoderma are also discussed.

A 42-year-old Italian man affected with a multisystemic disease is presented. The main features were: polyneuropathy, organomegaly (liver, spleen and lymph nodes enlargement), endocrinopathy (loss of libido, low plasmatic levels of testosterone), monoclonal protein (k-light chains only in 100-fold-concentrated urine sample, without other signs of plasmocytic proliferation), skin changes. Clinical skin alterations were striking: diffuse thickening, hyperpigmentation, hyperhidrosis , hypertrichosis, while histo- and immunopathological examination of skin biopsies showed proliferation of dermal collagen fibers and deposition of melanin in the epidermis. These findings were suggestive for the diagnosis of Crow-Fukase (POEMS) syndrome, associated with peculiar angiofollicular lymph node hyperplasia (Castleman's disease). The patient was followed up for 15 months with steroids, systemic chemotherapy, plasma-exchange and immunomodulating drugs. A massive anasarca complicated the picture leading him to death. Actually the pathomechanisms of this rare disease have not been fully elucidated. The relations between this syndrome and some malignant lymphoproliferative diseases (i.e. osteosclerotic myeloma) are controversial; at least a part of its features could be either reactive or tissue-specific-antibody mediated. A genetic influence should be suggested from the Japanese reports.

An homeopathic treatment with cuprum 4 CH, 24 and 5 hours before neostigmine (50 micrograms/kg/IP) administration has been done in the mouse. This treatment significantly reduces (Kruskal-Wallis: p less than 0.02) the faciliting action of neostigmine on intestinal transit.