3,021 research outputs found
Radioactive Waste Management of Fusion Power Plants
This chapter outlines the attractive environmental features of nuclear fusion, presents an integral scheme to manage fusion activated materials during operation and after decommissioning, compares the volume of fusion and fission waste, covers the recycling, clearance, and disposal concepts and their official radiological limits, and concludes with a section summarizing the newly developed strategy for fusion power plant
Strategies against nonsense: oxadiazoles as translational readthrough-inducing drugs (TRIDs)
This review focuses on the use of oxadiazoles as translational readthrough-inducing drugs (TRIDs) to rescue the functional full-length protein expression in mendelian genetic diseases caused by nonsense mutations. These mutations in specific genes generate premature termination codons (PTCs) responsible for the translation of truncated proteins. After a brief introduction on nonsense mutations and their pathological effects, the features of various classes of TRIDs will be described discussing differences or similarities in their mechanisms of action. Strategies to correct the PTCs will be presented, particularly focusing on a new class of Ataluren-like oxadiazole derivatives in comparison to aminoglycosides. Additionally, recent results on the efficiency of new candidate TRIDs in restoring the production of the cystic fibrosis transmembrane regulator (CFTR) protein will be presented. Finally, a prospectus on complementary strategies to enhance the effect of TRIDs will be illustrated together with a conclusive paragraph about perspectives, opportunities, and caveats in developing small molecules as TRIDs
Holocene slip rate variability along the Pernicana fault system (Mt. Etna, Italy): Evidence from offset lava flows
The eastern flank of the Mount Etna stratovolcano is affected by extension and is slowly sliding eastward into the Ionian Sea. The Pernicana fault system forms the border of the northern part of this sliding area. It consists of three E-W−oriented fault sectors that are seismically active and characterized by earthquakes up to 4.7 in magnitude (M) capable of producing ground rupture and damage located mainly along the western and central sectors, and by continuous creep on the eastern sector. A new topographic study of the central sector of the Pernicana fault system shows an overall bell-shaped profile, with maximum scarp height of 35 m in the center of the sector, and two local minima that are probably due to the complex morphological relation between fault scarp and lava flows. We determined the ages of lava flows cut by the Pernicana fault system at 12 sites using cosmogenic 3He and 40Ar/39Ar techniques in order to determine the recent slip history of the fault. From the displacement-age relations, we estimate an average throw rate of ∼2.5 mm/yr over the last 15 k.y. The slip rate appears to have accelerated during the last 3.5 k.y., with displacement rates of up to ∼15 mm/yr, whereas between 3.5 and 15 ka, the throw rate averaged ∼1 mm/yr. This increase in slip rate resulted in significant changes in seismicity rates, for instance, decreasing the mean recurrence time of M ≥ 4.7 earthquakes from ∼200 to ∼20 yr. Based on empirical relationships, we attribute the variation in seismic activity on the Pernicana fault system to factors intrinsic to the system that are likely related to changes in the volcanic system. These internal factors could be fault interdependencies (such as those across the Taupo Rift, New Zealand) or they could represent interactions among magmatic, tectonic, and gravitational processes (e.g., Kīlauea volcano, Hawaii). Given their effect on earthquake recurrence intervals, these interactions need to be fully assessed in seismic hazard evaluations
Evaluating the effect of information accuracy on travellers' concordance with Advanced Traveller Information Systems
EChO Payload electronics architecture and SW design
EChO is a three-modules (VNIR, SWIR, MWIR), highly integrated spectrometer,
covering the wavelength range from 0.55 m, to 11.0 m. The baseline
design includes the goal wavelength extension to 0.4 m while an optional
LWIR module extends the range to the goal wavelength of 16.0 m.
An Instrument Control Unit (ICU) is foreseen as the main electronic subsystem
interfacing the spacecraft and collecting data from all the payload
spectrometers modules. ICU is in charge of two main tasks: the overall payload
control (Instrument Control Function) and the housekeepings and scientific data
digital processing (Data Processing Function), including the lossless
compression prior to store the science data to the Solid State Mass Memory of
the Spacecraft. These two main tasks are accomplished thanks to the Payload On
Board Software (P-OBSW) running on the ICU CPUs.Comment: Experimental Astronomy - EChO Special Issue 201
E-PTFE (Gore-Tex) implant with or without low-dosage mitomycin-C as an adjuvant in penetrating glaucoma surgery: 2 year randomized clinical trial.
Purpose: To test the expanded polytetrafluoroethylene (ePTFE) as a new adjuvant
in trabeculectomy.
Methods: Consecutive glaucoma surgical inpatients were observed at the Department of Ophthalmology of Palermo University. Sixty patients (60 eyes)were randomly assigned to undergo trabeculectomy (T), trabeculectomy with
mitomycin-C (TMMC), with ePTFE (TG) or with mitomycin-C and ePTFE (TGMMC). Postoperative visits were scheduled at 24 hr, 7 days, 1, 3, 6, 12, 18 and 24 months. Complete success and qualified success were assessed at two target intraocular pressure (IOP) levels – £21 and £17 mmHg – by Kaplan–Meier curves.
Results: The postoperative IOP reduction was significant (P < 0.01) at the endpoint in all groups, with a mean IOP of 16.9 (±2.9), 16.2 (±2.7), 15.3 (±3.4) and 15.2 (±4.3) mmHg in T, TMMC, TG and TGMMC eyes, respectively. No intergroup difference was found at either IOP targets. The Kaplan–Meier curves relating to either the £21 mmHg or the £17 mmHg target
IOP did not show significant intergroup differences for complete and qualified
success rate. When ePTFE was used, a trend favouring the medium-term survival rate was noted. No adverse reaction to the ePTFE was present, and no membrane extrusion or conjuctival erosion were noted in any cases. Hypotony was significantly more frequent (P = 0.035) in groups without ePTFE.
Moreover, the late MMC-related complications were more frequent when MMC was applied.
Conclusion: Expanded polytetrafluoroethylene implant in trabeculectomy is well tolerated and could act as a filtration modulating device. Therefore, it is useful in reducing early hypotony-related complications and contributes to attaining medium-term IOP control that is comparable to the low-dosage MMC
The Visible and Near Infrared module of EChO
The Visible and Near Infrared (VNIR) is one of the modules of EChO, the
Exoplanets Characterization Observatory proposed to ESA for an M-class mission.
EChO is aimed to observe planets while transiting by their suns. Then the
instrument had to be designed to assure a high efficiency over the whole
spectral range. In fact, it has to be able to observe stars with an apparent
magnitude Mv= 9-12 and to see contrasts of the order of 10-4 - 10-5 necessary
to reveal the characteristics of the atmospheres of the exoplanets under
investigation. VNIR is a spectrometer in a cross-dispersed configuration,
covering the 0.4-2.5 micron spectral range with a resolving power of about 330
and a field of view of 2 arcsec. It is functionally split into two channels
respectively working in the 0.4-1 and 1.0-2.5 micron spectral ranges. Such a
solution is imposed by the fact the light at short wavelengths has to be shared
with the EChO Fine Guiding System (FGS) devoted to the pointing of the stars
under observation. The spectrometer makes use of a HgCdTe detector of 512 by
512 pixels, 18 micron pitch and working at a temperature of 45K as the entire
VNIR optical bench. The instrument has been interfaced to the telescope optics
by two optical fibers, one per channel, to assure an easier coupling and an
easier colocation of the instrument inside the EChO optical bench.Comment: 26 page
Cigarette smoke increases BLT2 receptor functions in bronchial epithelial cells: in vitro and ex vivo evidence
Leukotriene B4 (LTB4) is a neutrophil chemotactic molecule with important
involvement in the inflammatory responses of chronic obstructive
pulmonary disease (COPD). Airway epithelium is emerging as a regulator
of innate immune responses to a variety of insults including cigarette
smoke, the major risk factor for COPD. In this study we have explored
whether cigarette smoke extracts (CSE) or soluble mediators present in
distal lung fluid samples (mini-bronchoalveolar lavages) from smokers
alter the expression of the LTB4 receptor 2 (BLT2) and peroxisome proliferator-
activated receptor-a (PPAR-a) in bronchial epithelial cells. We also
evaluated the effects of CSE on the expression of intercellular adhesion
molecule 1 (ICAM-1) and on the binding of signal transducer and activator
of transcription 1 (STAT-1) to ICAM-1 promoter as well as the
adhesiveness of neutrophils to bronchial epithelial cells. CSE and minibronchoalveolar
lavages from smokers increased BLT2 and ICAM-1
expression as well as the adhesiveness of neutrophils to bronchial epithelial
cells and decreased PPAR-a expression. CSE induced the activation of
STAT-1 and its binding to ICAM-1 promoter. These findings suggest that,
in bronchial epithelial cells, CSE promote a prevalent induction of
pro-inflammatory BLT2 receptors and activate mechanisms leading to
increased neutrophil adhesion, a mechanism that contributes to airway
neutrophilia and to tissue damage
A class of pyrrole derivatives endowed with analgesic/anti-inflammatory activity
We report the synthesis and bio-pharmacological evaluation of a class of pyrrole derivatives featuring a small appendage fragment (carbaldehyde, oxime, nitrile) on the central core. Compound 1c proved to be extremely effective in vivo, showing an interesting anti-nociceptic profile that is comparable to reference compounds already marketed, hence representing a great stimulus for a further improvement of this class of molecules
Novel analgesic/anti-inflammatory agents: 1,5-diarylpyrrole nitrooxyalkyl ethers and related compounds as cyclooxygenase-2 inhibiting nitric oxide donors
A series of 3-substituted 1,5-diarylpyrroles bearing a nitrooxyalkyl side chain linked to different spacers were designed. New classes of pyrrole-derived nitrooxyalkyl inverse esters, carbonates, and ethers (7-10) as COX-2 selective inhibitors and NO donors were synthesized and are herein reported. By taking into account the metabolic conversion of nitrooxyalkyl ethers (9, 10) into corresponding alcohols, derivatives 17 and 18 were also studied. Nitrooxy derivatives showed NO-dependent vasorelaxing properties, while most of the compounds proved to be very potent and selective COX-2 inhibitors in in vitro experimental models. Further in vivo studies on compounds 9a,c and 17a highlighted good anti-inflammatory and antinociceptive activities. Compound 9c was able to inhibit glycosaminoglycan (GAG) release induced by interleukin-1β (IL-1β), showing cartilage protective properties. Finally, molecular modeling and (1)H- and (13)C-NMR studies performed on compounds 6c,d, 9c, and 10b allowed the right conformation of nitrooxyalkyl ester and ether side chain of these molecules within the COX-2 active site to be assessed
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