146 research outputs found
Abcès hypophysaire chez un hémodialysé chronique traité médicalement : à propos d’une observation
L’abcès hypophysaire est une pathologie rare et fatale en absence de traitement adéquat .Il est à évoquer devant un tableau clinique d’hypertension intracrânienne, une dysrégulation hormonale hypophysaire et un contexte infectieux. Une conduite thérapeutique basée sur une antibiothérapie pourrait être tenté si diagnostic précoce. Nous rapportons un cas d’abcès hypophysaire survenant chez un hémodialysé chronique pris en charge par une antibiothérapie seule dont l’évolution était favorable avec un recul de 2 ans
Buried anti resonant reflecting optical waveguide based on porous silicon material for an integrated Mach Zehnder structure
Rich polymorphism of a rod-like liquid crystal (8CB) confined in two types of unidirectional nanopores
We present a neutron and X-rays scattering study of the phase transitions of
4-n-octyl-4'-cyanobiphenyl (8CB) confined in unidirectional nanopores of porous
alumina and porous silicon (PSi) membranes with an average diameter of 30 nm.
Spatial confinement reveals a rich polymorphism, with at least four different
low temperature phases in addition to the smectic A phase. The structural study
as a function of thermal treatments and conditions of spatial confinement
allows us to get insights into the formation of these phases and their relative
stability. It gives the first description of the complete phase behavior of 8CB
confined in PSi and provides a direct comparison with results obtained in bulk
conditions and in similar geometric conditions of confinement but with reduced
quenched disorder effects using alumina anopore membranesComment: Accepted in EPJ E - Soft Matte
Dynamics of 8CB confined into porous silicon probed by incoherent neutron backscattering experiments
Confinement in the nanochannels of porous silicon strongly affects the phase
behavior of the archetype liquid-crystal 4-n-octyl-4-cyanobiphenyl (8CB). A
very striking phenom- enon is the development of a short-range smectic order,
which occurs on a very broad temperature range. It suggests in this case that
quenched disorder effects add to usual finite size and surface interaction
effects. We have monitored the temperature variation of the molecular dynamics
of the confined fluid by incoherent quasielastic neutron scat- tering. A
strongly reduced mobility is observed at the highest temperatures in the liquid
phase, which suggests that the interfacial molecular dynamics is strongly
hindered. A continuously increasing slowdown appears on cooling together with a
progressive growth of the static correlation lengt
M004 In aortic stenosis, 2D speckle tracking differentiates left ventricular dysfunction load- to remodelling-dependant
BackgroundIn aortic stenosis, it is not known which between longitudinal, radial and circumferential contraction is influenced by loading conditions or remodelling. To test our hypothesis and to understand left ventricular function recovery, we investigated patients at early, i.e. 7 days (contractility enhancement load-dependant) and at late follow-up, i.e. 3 months (contractility enhancement remodelling-dependant) after transcutaneous aortic valve implantation (TAVI).Methods and ResultsTwenty-three subjects (AS: valve orifice < or =0.7cm2; 14 female; mean age, 84+/-6 years) were studied. All subjects of the study had conventional 2D-Doppler echocardiography and speckle tracking analysis (GE HealthCare). Speckle tracking was sampled in short-axis view for radial and circumferential strain and in apical 4, 3 and 2-chamber view for averaged longitudinal strain. Measurements were performed before, 7 days and 3 months after TAVI. Mean pressure gradient decreased from 41±20mmHg to 10±3mmHg (p<0.001) while aortic valve area increased from 0.6±0.1 to 1.7±0.2cm2 (p<0.001) after implantation. Biplane Simpson EF was 50±10 %, 51±13 and 58±11 % at baseline, 7-day and 3-month follow-up (p=0.01), respectively. Improvement of circumferential strain found 7 days after TAVI is sustained at 3 months. Radial strain increased shortly after TAVI, then decreased at 3 months and was compensated by improvement of longitudinal strain (see figure).ConclusionIn patients with aortic stenosis, radial contraction is load dependant, circumferential contraction is both load- and remodelling-dependant, whereas longitudinal contraction is remodeling-dependant
Molecular dynamics of glycerol and glycerol-trehalose bioprotectant solutions nanoconfined in porous silicon
Glycerol and trehalose-glycerol binary solutions are glass-forming liquids
with remarkable bioprotectant properties. Incoherent quasielastic neutron
scattering (QENS) is used to reveal the different effects of nanoconfinement
and addition of trehalose on the molecular dynamics in the normal liquid and
supercooled liquid phases, on a nanosecond timescale. Confinement has been
realized in straight channels of diameter D=8 nm formed by porous silicon. It
leads to a faster and more inhomogeneous relaxation dynamics deep in the liquid
phase. This confinement effect remains at lower temperature where it affects
the glassy dynamics. The glass transitions of the confined systems are shifted
to low temperature with respect to the bulk ones. Adding trehalose tends to
slow down the overall glassy dynamics and increases the non-exponential
character of the structural relaxation. Unprecedented results are obtained for
the binary bioprotectant solution, which exhibits an extremely non-Debye
relaxation dynamics as a result of the combination of the effects of
confinement and mixing of two constituents
Canopy Temperature Efficiency as Indicators for Drought Tolerance in Durum Wheat (Triticum Durum Desf.) in Semi Arid Conditions
Durum wheat (Triticum durum Desf.) is one of the more widely cultivated crops in the Mediterranean basin, where drought is the main abiotic stress limiting its production. This study was conducted on the experimental site of station ITGC in Setif, Algeria. The objectives of this study were (i) to determine differences in canopy temperature (CT) and canopy temperature depression (CTD) of different durum wheat under both well-watered and moisture stressed conditions and (ii) to correlate canopy temperature (CT) and canopy temperature depression (CTD) with drought resistance indices value and yield of durum wheat (Triticum durum Desf.) under both conditions. The results of study showed a significant difference between CT and CTD under both conditions and among genotypes. Under dryland conditions, grain yield and mean CTD were correlated positively (r = 0.32**), this correlation is similar to other studies (Blum et al., 1989; Royo et al., 2002). Similar results of correlation between canopy temperature (CT), canopy temperature depression (CTD) and grain yield suggest that the use of CT and CTD in screening for highly tolerant varieties to drought is similar. The significant correlation of CT and CTD with Mean productivity (MP) and Stress tolerance index (STI) suggests that CTD and/or CT can be favorite selection criteria in plant breeding for drought tolerance
Relationship between Flag Leaf Reflectance and Canopy Temperature in Durum Wheat (Triticum durum Desf.) Cultivars under Stressed and Irrigated Conditions
Optical technologies can be developed as practical tools for monitoring plant health by providing unique spectral signatures that can be related to specific plant stresses. The objectives of this study were (i) to determine differences in canopy temperature and leaf reflectance of different durum wheat under both well-watered and moisture stressed conditions and (ii) evaluate the relationships between canopy temperature and leaf reflectance at Red and Blue (RB) wavelength. We use numerical image analysis by Mesurim Pro (Version 3.3) softwarefor estimate leaf reflectance at Red and Blue (RB) wavelength.In this study irrigation treatments affect significantly flag leaf reflectance at RB and canopy temperature. Significant correlations were registered between leaf reflectance and canopy temperature under both conditions irrigated and non irrigated; these best correlations proved the efficiency of using leaf reflectance at RB in screening for drought tolerance in durum wheat cultivars
Molecular dynamics of a short range ordered smectic phase nanoconfined into porous silicon
4-n-octyl-4-cyanobiphenyl (8CB) has been recently shown to display an unusual
sequence of phases when confined into porous silicon (PSi). The gradual
increase of oriented short-range smectic (SRS) correlations in place of a phase
transition has been interpreted as a consequence of the anisotropic quenched
disorder induced by confinement in PSi. Combining two quasielastic neutron
scattering experiments with complementary energy resolutions, we present the
first investigation of the individual molecular dynamics of this system. A
large reduction of the molecular dynamics is observed in the confined liquid
phase, as a direct consequence of the dynamical boundary conditions imposed by
the confinement. Temperature fixed window scans (FWS) reveal a continuous
'glass-like' reduction of the molecular dynamics of the confined liquid and SRS
phases on cooling down to 250 K, where a solid-like behavior is finally reached
by a two steps crystallization process
Unassisted and carbon dioxide-assisted hydro- and Steam-distillation: modelling kinetics, energy consumption And chemical and biological activities of volatile oils
The demand for more suitable eco-friendly extraction processes has grown over the last few
decades and driven research to develop efficient extraction processes with low energy consumption
and low costs, but always assuring the quality of the volatile oils (VOs). The present study estimated
the kinetic extraction and energy consumption of simultaneous hydro- and steam-distillation (SHSD),
and SHSD assisted by carbon dioxide (SHSDACD), using an adopted modelling approach. The two
isolation methods influenced the VOs yield, chemical composition and biological activities, namely,
antioxidant, anti-glucosidase, anti-acetylcholinesterase and anti-inflammatory properties. SHSDACD
provided higher VOs yields than the SHSD at a shorter extraction time: 2.8% at 30 min vs. 2.0% at
120 min, respectively, for Rosmarinus officinalis, 1.5% at 28 min vs. 1.2% at 100 min, respectively, for
Lavandula angustifolia, and 1.7% at 20 min vs. 1.6% at 60 min, respectively, for Origanum compactum.
The first order and sigmoid model fitted to SHSD and SHSDACD, respectively, with R2 value at 96%
and with mean square error (MSE) < 5%, where the k distillation rate constant of SHSDACD was
fivefold higher and the energy consumption 10 times lower than the SHSD. The rosemary SHSD
and SHSDACD VOs chemical composition were similar and dominated by 1,8-cineole (50% and
48%, respectively), and camphor (15% and 12%, respectively). However, the lavender and oregano
SHSDACD VOs were richer in linalyl acetate and carvacrol, respectively, than the SHSD VOs. The
SHSDACD VOs generally showed better capacity for scavenging the nitric oxide and superoxide
anions free radicals as well as for inhibiting α-glucosidase, acetylcholinesterase, and lipoxygenase.info:eu-repo/semantics/publishedVersio
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