Improvement of effect of water-in-oil microemulsion as an oral delivery system for fexofenadine: in vitro and in vivo studies

Fexofenadine (FEX) has high solubility and low permeability (BCS, Class III). In this work, novel FEX loaded water in oil microemulsion (w/o) was designed to improve bioavailability and compared with Fexofen® syrup in in vitro and in vivo studies. In addition, pharmacokinetic parameters in permeability studies were estimated by using WinNonLin software program. w/o microemulsion system was optimized using a pseudoternary phase diagram, composed of span 80/lutrol F 68 (9.5:0.5 w/w), oleic acide, isopropyl alcohol and water as surfactant mixture; oil and cosurfactant was developed for oral drug delivery. w/o microemulsion systems were characterized by phase behavior, particle size, viscosity and solubilization capacity. In vitro studies were studied using Caco-2 cell monolayer. Pharmacokinetic parameters of w/o microemulsion were investigated in rabbits and compared to Fexofen® syrup. Fexofen® syrup and microemulsion were administered by oral gavage at 6 mg/kg of the same concentration. The experimental results indicated that microemulsion (HLB = 5.53) formed nanometer sized droplets (33.29 ± 1.76) and had good physical stability. This microemulsion increased the oral bioavailability of FEX which was highly water-soluble but fairly impermeable. The relative bioavailability of FEX microemulsion was about 376.76% compared with commercial syrup in rabbits. In vitro experiments were further employed for the enhanced effect of the microemulsion for FEX. These results suggest that novel w/o microemulsion plays an important role in enhancing oral bioavailability of low permeability drugs

Seasonal cycle of precipitation variability in South America on intraseasonal timescales

The seasonal cycle of the intraseasonal (IS) variability of precipitation in South America is described through the analysis of bandpass filtered outgoing longwave radiation (OLR) anomalies. The analysis is discriminated between short (10--30 days) and long (30--90 days) intraseasonal timescales. The seasonal cycle of the 30--90-day IS variability can be well described by the activity of first leading pattern (EOF1) computed separately for the wet season (October--April) and the dry season (May--September). In agreement with previous works, the EOF1 spatial distribution during the wet season is that of a dipole with centers of actions in the South Atlantic Convergence Zone (SACZ) and southeastern South America (SESA), while during the dry season, only the last center is discernible. In both seasons, the pattern is highly influenced by the activity of the Madden--Julian Oscillation (MJO). Moreover, EOF1 is related with a tropical zonal-wavenumber-1 structure superposed with coherent wave trains extended along the South Pacific during the wet season, while during the dry season the wavenumber-1 structure is not observed. The 10--30-day IS variability of OLR in South America can be well represented by the activity of the EOF1 computed through considering all seasons together, a dipole but with the stronger center located over SESA. While the convection activity at the tropical band does not seem to influence its activity, there are evidences that the atmospheric variability at subtropical-extratropical regions might have a role. Subpolar wavetrains are observed in the Pacific throughout the year and less intense during DJF, while a path of wave energy dispersion along a subtropical wavetrain also characterizes the other seasons. Further work is needed to identify the sources of the 10--30-day-IS variability in South America

Mid-infrared imaging- and spectro-polarimetric subarcsecond observations of NGC 1068

We present sub-arcsecond 7.5$-$13 $\mu$m imaging- and spectro-polarimetric observations of NGC 1068 using CanariCam on the 10.4-m Gran Telescopio CANARIAS. At all wavelengths, we find: (1) A 90 $\times$ 60 pc extended polarized feature in the northern ionization cone, with a uniform $\sim$44$^{\circ}$ polarization angle. Its polarization arises from dust and gas emission in the ionization cone, heated by the active nucleus and jet, and further extinguished by aligned dust grains in the host galaxy. The polarization spectrum of the jet-molecular cloud interaction at $\sim$24 pc from the core is highly polarized, and does not show a silicate feature, suggesting that the dust grains are different from those in the interstellar medium. (2) A southern polarized feature at $\sim$9.6 pc from the core. Its polarization arises from a dust emission component extinguished by a large concentration of dust in the galaxy disc. We cannot distinguish between dust emission from magnetically aligned dust grains directly heated by the jet close to the core, and aligned dust grains in the dusty obscuring material surrounding the central engine. Silicate-like grains reproduce the polarized dust emission in this feature, suggesting different dust compositions in both ionization cones. (3) An upper limit of polarization degree of 0.3 per cent in the core. Based on our polarization model, the expected polarization of the obscuring dusty material is $\lesssim$0.1 per cent in the 8$-$13 $\mu$m wavelength range. This low polarization may be arising from the passage of radiation through aligned dust grains in the shielded edges of the clumps.Comment: 17 pages, 10 figures, accepted for publication at MNRA

High Resolution Spectroscopy of the high galactic latitude RV Tauri star CE Virginis

Analysis of the surface composition of the suspected cool RV Tauri star CE Vir shows no systematic trend in depletions of elements with respect to condensation temperature. However, there is a significant depletion of the elements with respect to the first ionization potential of the element. The derived Li abundance of log $\epsilon$ (Li) = 1.5$\pm$0.2 indicates production of Li in the star. Near infrared colours indicate sporadic dust formation close to the photosphere.Comment: 12 pages, including 8 pages: Accepted for publication in MNRA

Aging-associated symptoms in the physician-patient dialogue in a group of long-term diagnosed HIV-infected individuals

Background: The significant decrease in mortality has resulted in a large number of individuals aged over 50 living with HIV infection. Additionally, the coexistence of certain pathologies suggests premature aging. In this scenario, the presence of aging-associated symptoms in the physician-patient dialogue is yet to be explored. Methods: Cross-sectional observational study to evaluate the presence of aging-associated symptoms in the physician-patient dialogue and to explore the possible differences between genders in a sample of 100 HIV-1 infected subjects diagnosed at least 15 years ago. The survey assessed questions/comments made by the patient, questions/comments made by the physician and patients’ interest in obtaining more information than was provided. Number of patients and percentages were given and compared using the w2 or Fisher exact test (as appropriate). Results: Participants were 60 men and 40 women, diagnosed with HIV infection a median (IQ) of 18 (15.7–21) years ago, who had a nadir CD4 and CD4 cell count at the study entry of 172 (95–272) and 543 (403–677), respectively. Eighty percent of the subjects had VL <25 copies and 42% were HCV/HIV co-infected (31 subjects with low fibrosis stage). The infection route had been mainly intravenous drug use (37%) and MSM (32%). Men and women had similar demographic and clinical characteristics. Sixty-two percent of the participants acknowledged asking their physicians about aging-associated symptoms (58% men vs 66% women; p=0.50), 48% reported that their physicians had provided information without having been asked (48% men vs 55% women; p=0.51) and 75% confirmed that they would like to have more information about aging-associated symptoms (22% men vs 80% women; p<0.001). Conclusions: Around half of the men and women interviewed had discussed aging-associated symptoms with their physician. However, this seemed insufficient for four-fifths of the women, who would have liked to have obtained more information about aging

Prospects for observations of high-energy cosmic tau neutrinos

We study prospects for the observations of high-energy cosmic tau neutrinos (E \geq 10^6 GeV) originating from proton acceleration in the cores of active galactic nuclei. We consider the possibility that vacuum flavor neutrino oscillations induce a tau to muon neutrino flux ratio greatly exceeding the rather small value expected from intrinsic production. The criterias and event rates for under water/ice light Cerenkov neutrino telescopes are given by considering the possible detection of downgoing high-energy cosmic tau neutrinos through characteristic double shower events.Comment: 10 pages, Revtex, 3 figures included with eps

Key paramaters in the design of HiPER reaction chamber

The future chamber reactor of HiPER will have to withstand short energy pulses (3 μs long) of up to 5 MJ of charged particles and X-rays with different repetition rates. Nowadays, tungsten has been selected as first wall material for a 5m radius reaction chamber. From the thermo-mechanical point of view, experiments have demonstrated that tungsten can withstand heat flux parameters up to 28 MJm-2 s -1/2 without roughening and 40 MJm-2 s -1/2 without undergoing melting. From the atomic point of view, He retention and bubble formation represents the biggest threat to its survivability, being doses of ~10 17 He/cm2 the upper limit for safe operation. Comparison of these limiting values with those proposed for a 48 MJ shock ignition target in HiPER reveals that, under a reasonable plan of 1000 fusion shots during the chamber lifetime, tungsten should guarantee a proper performance of the first wall