51 research outputs found
When Meta-Surfaces Meet Users: Optimization of Smart Radio Environments in 6G Sub-THz Communications
We consider a smart radio environment where meta-surfaces are employed to
improve the performance of wireless networks working at sub-THz frequencies. To
this end, we propose a comprehensive mathematical channel model, taking into
account both the ability of the meta-surfaces to redirect the impinging signal
towards a desired direction, and the signal reflection due to large objects. We
show how the design of both the meta-surface and the transmitter precoder
influences the network throughput. Furthermore, we compare several algorithms
to optimize the effect of the meta-surfaces in a realistic scenario. As a
result, a simpler algorithm that associates network users and meta-surfaces
provides a performance comparable to more complex numerical optimization
methods. Simulation results suggest how many users are supported in the
designed system
Characterization of novel clonal murine endothelial cell lines with an extended life span
Summary: A murine endothelial cell line was recently established from microvessels that had invaded a subcutaneous sponge implant (Dong, Q. G.; Bernasconi, S.; Lostaglio, S., et al. Arterioscl. Thromb. Vasc. Biol. 17:1599-1604; 1997). From these sponge-induced endothelial (SIE) cells, we have isolated two subpopulations endowed with different phenotypic properties. Clone SIE-F consists of large, highly spread cells that have a relatively slow growth rate, form contact-inhibited monolayers, do not grow under anchorage-independent conditions, express elevated levels of thrombospondin-1 (TSP-1) and are not tumorigenic in vivo. In contrast, clone SIE-S2 consists of small, spindle-shaped cells that have a high proliferation rate, do not show contact-inhibition, grow under anchorage-independent conditions, express very low levels of TSP-1 and are tumorigenic in vivo. Both clones express the endothelial markers vascular endothelial-cadherin and vascular intercellular adhesion molecule-1, but do not express CD31 and E-selectin. In addition, SIE-S2 cells, but not SIE-F cells, express the α-smooth muscle actin isoform. SIE-S2 cells, but not SIE-F cells, are able to form branching tubes in fibrin gels. The SIE-F and SIE-S2 clones, which have properties of nontransformed and transformed cells, respectively, should provide useful tools to investigate physiological and pathological processes involving vascular endotheliu
Pentraxin 3 Plasma Levels and Disease Activity in Systemic Lupus Erythematosus
SLE is an autoimmune disorder that involves polyclonal autoimmunity against multiple autoantigens. PTX3, a marker of the acute-phase inflammatory response, plays an important role in innate immunity and in modulation of the adaptive immune response. Our study tried to resolve some rather controversial aspects of the use of PTX3 as a biomarker of disease activity in SLE patients. We demonstrated that plasma PTX3 concentration of the SLE patients was significantly higher than the healthy control groups and reflected disease activity. ROC curve analysis was used to determine best cut-off point (2.8 ng/mL) with a good sensitivity and specificity. In patients with SLE, PTX3 concentrations were correlated with SLEDAI. Trend to remission (TTR) curve was created by plotting PTX3 levels and SLEDAI and we applied the curve as a model for the analysis of two patients with different follow-up. PTX3 plasma levels declined significantly and this decline occurred parallel to the clinical improvement with a complete remission of disease. In patients who experienced a clinical relapse, an increase in PTX3 levels followed the lupus flare. The proposal of PTX3 cut-off associated with TTR and monitoring of PTX3 plasma levels could be an innovative approach to follow-up of SLE patients
Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study
BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223
A new fast methodology to estimate the density of frozen materials by means of common offset GPR data
We propose a methodology to estimate the density of frozen media (snow, firn and ice) using common offset (CO) GPR data. The technique is based on reflection amplitude analysis to calculate the series of reflection coef- \u2423cients used to estimate the dielectric permittivity of each layer. We determine the vertical density variations for all the GPR traces by applying an empirical equation. We are thus able to infer the nature of frozen materials, from fresh snow to firn and ice. The proposed technique is critically evaluated and validated on synthetic data and further tested on real data of the Glacier of Mt. Canin (South-Eastern Alps). Despite the simplifying hypotheses and the necessary approximations, the average values of density for different levels are calculated with acceptable accuracy. The resulting large-scale density data are fundamental to estimate the water equivalent (WE), which is an essential parameter to determine the actual water mass within a certain frozen volume. Moreover, this analysis can help to find and locate debris or moraines embedded within the ice bodies
TEMPERATURE-PROGRAMMED OXIDATIVE DECOMPOSITION (TPOD) TECHNIQUE FOR THE CHARACTERIZATION OF SUPPORTED METAL-CLUSTERS - A COMPARISON WITH DIFFERENTIAL THERMAL GRAVIMETRY (DTG) TECHNIQUE
TEMPERATURE-PROGRAMMED OXIDATIVE DECOMPOSITION (TPOD) TECHNIQUE FOR THE CHARACTERIZATION OF SUPPORTED METAL-CLUSTERS - A COMPARISON WITH DIFFERENTIAL THERMAL GRAVIMETRY (DTG) TECHNIQUE
The surface chemistry of supported organometallic clusters as precursors of heterogeneous catalysts is investigated by means of DTG (differential thermal gravimetry) and TPOD (temperature-programmed oxidative decomposition) techniques, as unique signatures of the occurrence of chemical interactions between the organometallic cluster and the surface sites of the support
SURFACE ORGANOMETALLIC CHEMISTRY - A MOLECULAR APPROACH TO HETEROGENEOUS CATALYSIS AND A NEW PERSPECTIVE FOR THE SYNTHESIS OF METAL-CARBONYL CLUSTERS
Synthesis and structural characterization of chiral smectic C and smectic A poly(vinyl ether)s
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