A stellar occultation by Neptune's main satellite, Triton, was observed on 5 October 2017 from Europe, North Africa, and the USA. We derived 90 light curves from this event, 42 of which yielded a ...central flash detection. We aimed at constraining Triton's atmospheric structure and the seasonal variations of its atmospheric pressure since the Voyager 2 epoch (1989). We also derived the shape of the lower atmosphere from central flash analysis. We used Abel inversions and direct ray-tracing code to provide the density, pressure, and temperature profiles in the altitude range \(\sim\)8 km to \(\sim\)190 km, corresponding to pressure levels from 9 {\mu}bar down to a few nanobars. Results. (i) A pressure of 1.18\(\pm\)0.03 {\mu}bar is found at a reference radius of 1400 km (47 km altitude). (ii) A new analysis of the Voyager 2 radio science occultation shows that this is consistent with an extrapolation of pressure down to the surface pressure obtained in 1989. (iii) A survey of occultations obtained between 1989 and 2017 suggests that an enhancement in surface pressure as reported during the 1990s might be real, but debatable, due to very few high S/N light curves and data accessible for reanalysis. The volatile transport model analysed supports a moderate increase in surface pressure, with a maximum value around 2005-2015 no higher than 23 {\mu}bar. The pressures observed in 1995-1997 and 2017 appear mutually inconsistent with the volatile transport model presented here. (iv) The central flash structure does not show evidence of an atmospheric distortion. We find an upper limit of 0.0011 for the apparent oblateness of the atmosphere near the 8 km altitude.
LDPE/montmorillonite and LDPE/kaolinite compounds were prepared by twin-screw extrusion using two screw profiles. The microstructure of the samples was determined by a combination of techniques: wide ...angle X-ray scattering (WAXS), optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and small amplitude rheometry. This work presents also a new technique as a macroscopic measurement of the morphology of bulk filled polymers: in-line monitoring of low energy ultrasound waves during melt extrusion. Transit time, signal loss and peak height of ultrasound waves transmitted through the melt polymer were measured for all the samples. These parameters appeared to provide significant information of dispersion levels or aggregate size, and maintained a good correlation with the microscopic studies and the rheological data.
Abstract Introduction Psoriasis is a chronic inflammatory disease associated with an increased risk of ischemic coronary artery disease (CAD) in some populations. We aimed to determine the ...association between these 2 diseases in our geographic area. Material and method We performed a cross-sectional study of patient records between 2005 and 2012 in the database (Abucacis, Datamart) that contains all medical case histories in the province of Castellón, Spain. Patients diagnosed with psoriasis were compared with a control group of patients diagnosed with melanocytic nevus. The prevalence of CAD and the presence or absence of the main cardiovascular risk factors were analyzed in each group. Results A total of 9181 patients with psoriasis and 21925 with melanocytic nevus were studied. Univariate logistic regression analysis showed that CAD was significantly associated with psoriasis, age (in years), sex, hypertension, diabetes mellitus, dyslipidemia, and obesity ( P < .05). On adjustment for age, sex, and the other cardiovascular risk factors, multivariate regression analysis established that psoriasis was independently associated with CAD ( P < .029). Conclusion Our findings in a large sample of patients in a Mediterranean area support the hypothesis that patients in this population have an increased risk of ischemic CAD.
A new case of pneumococcal meningitis in a child successfully treated with imipenem-cilastatin after failure of standard antibiotics is presented. Seizures, as the major adverse effect, were easily ...treated and no sequelae were later observed. The difficulty in distinguishing between seizures due to meningitis and those due to imipenem is discussed. We conclude that imipenem-cilastatin is a good alternative therapy in children's meningitis caused by pneumococcus resistant to standard antibiotics.
A series of tetrahydroisoquinolines functionalized with carbamates is reported here as highly selective ligands on the dopamine D2 receptor. These compounds were selected by means of a molecular ...modeling study. The studies were carried out in three stages: first an exploratory study was carried out using combined docking techniques and molecular dynamics simulations. According to these results, the bioassays were performed; these experimental studies corroborated the results obtained by molecular modeling. In the last stage of our study, a QTAIM analysis was performed in order to determine the main molecular interactions that stabilize the different ligand-receptor complexes. Our results show that the adequate use of combined simple techniques is a very useful tool to predict the potential affinity of new ligands at dopamine D1 and D2 receptors. In turn the QTAIM studies show that they are very useful to evaluate in detail the molecular interactions that stabilize the different ligand-receptor complexes; such information is crucial for the design of new ligands.
A simultaneous analysis of the transport properties of water through extruded food packaging films made of ethylene–vinyl alcohol copolymers (EVOH) with various ethylene contents, i.e. ranging from ...26 to 48
mol% of ethylene, and of water polymer interactions have been carried out using fourier transform infrared spectroscopy (FT-IR). This study is part of a more extensive project, the overall aim of which is to demonstrate the capabilities of the FT-IR technique to test transport properties in high barrier plastic films of interest in food packaging applications. A characterization of solvent uptake (water sorption isotherms), diffusion and permeability coefficients as a function of ethylene content and relative humidity has been carried out across the above composition regime. From the results, an unreported Langmuir contribution was found at low relative humidity conditions for the copolymers, which could be responsible for the unusual trend in oxygen permeability reported earlier for these materials. Furthermore, a distribution of water molecules with different hydrogen bonding strengths and different diffusion rates was encountered, which suggests that the interaction and transport properties of moisture in these polymers is far from being a simple and homogeneous process.
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