10,740 research outputs found
Synthesis of titanium-containing ZSM-48
Titanium-containing ZSM-48 is synthesized with silicon to titanium ratios of 26 or larger; changes in unit cell volume and IR data show that titanium is incorporated into framework positions
Empty nose syndrome
SummaryEmpty nose syndrome (ENS) is a clinical entity without consensual definition; it is a rare complication of nose or sinus surgery, and of inferior turbinectomy in particular. Physiopathology remains unclear, but probably involves disorder caused by excessive nasal permeability affecting neurosensitive receptors and inhaled air humidification and conditioning functions. Neuropsychological involvement is suspected. Symptomatology is variable and changeable, the most common sign being paradoxical nasal obstruction. Diagnosis is founded on: (1) a range of symptoms that need to be precisely collated; (2) broad post-surgical nasal permeability. Management is problematic, deploying the full range of simple nasal cavity hygiene and humidification techniques, with surgery reserved for the most severe cases; whatever the technique, surgery aims at partial filling of the nasal airway. Prevention is the most important strategy, and seeks (1) to check, before any surgery is envisaged, the reality of nasal dyspermeability resistant to medical treatment; and (2) to prefer the most conservative surgical techniques
Replicase mediated resistance against Potato Leafroll Virus in potato Desirée plants.
Potato leafroll virus (PLRV) is a major menace for the potato production all over the world. PLRV is transmitted by aphids, and until now, the only strategy available to control this pest has been to use large amounts of insecticides. Transgenic approaches involving the expression of viral replicases are being developed to provide protection for plants against viral diseases. The purpose of this study was to compare the protection afforded by the differential expression of PLRV replicase transgene in potato plants cv. Desirée. Plants were genetically modified to express the complete sense PLRV replicase gene. Two constructions were used, one containing the constitutive 35SCaMV promoter and the other the phloem-specific RolA promoter from Agrobacterium rhizogenes. Transgenic plants were infected with PLRV in vitro, using infested aphids. In plants in which 35SCaMV controlled the expression of the PLRV replicase gene, signs of infection were initially detected, although most plants later developed a recovery phenotype showing undetectable virus levels 40 days after infection. In turn, those plants with the RolA promoter displayed an initial resistance that was later overcome. Different molecular mechanisms are likely to participate in the response to PLRV infection of these two types of transgenic plants
Fluctuating hydrodynamic modelling of fluids at the nanoscale
A good representation of mesoscopic fluids is required to combine with
molecular simulations at larger length and time scales (De Fabritiis {\it et.
al}, Phys. Rev. Lett. 97, 134501 (2006)). However, accurate computational
models of the hydrodynamics of nanoscale molecular assemblies are lacking, at
least in part because of the stochastic character of the underlying fluctuating
hydrodynamic equations. Here we derive a finite volume discretization of the
compressible isothermal fluctuating hydrodynamic equations over a regular grid
in the Eulerian reference system. We apply it to fluids such as argon at
arbitrary densities and water under ambient conditions. To that end, molecular
dynamics simulations are used to derive the required fluid properties. The
equilibrium state of the model is shown to be thermodynamically consistent and
correctly reproduces linear hydrodynamics including relaxation of sound and
shear modes. We also consider non-equilibrium states involving diffusion and
convection in cavities with no-slip boundary conditions
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