651 research outputs found
Device for producing and enclosing a hot plasma
1391103 High-frequency discharge tubes EUROPEAN ATOMIC ENERGY COM- MUNITY 24 July 1972 [23 July 1971] 34566/72 Heading H1D A device for producing and enclosing a hot plasma comprises a toroidal vessel 1 having means 2 for generating a magnetic field along the azimuthal axis 3 of the torus to induce annular electric currents along said axis, and means 6, 7 for generating an oscillating electric field in the vessel having a component parallel to the magnetic field and a frequency at or near the bounce frequency (i.e. about ten times the collison frequency of ions.) A second toroidal vessel or liner 4 is disposed in the first vessel 1, and the diameter of the plasma is limited by annular discs 5. The electric field is generated by annular electrodes 6 and 7 disposed above and below the axis 3 and connected through insulated ducts 8 to a generator producing oscillations having a fre- quency between 10 and 100 KHz. The electric field may alternatively be produced by an aerial disposed in an aperture in the vessel wall and fed with a signal having a fundamental frequency corresponding to the plasma frequency which is amplitude modulated at the bounce frequency
An estimate of attributable cases of alzheimer disease and vascular dementia due to modifiable risk factors. the impact of primary prevention in europe and in italy
Background:
Up to 53.7% of all cases of dementia are assumed to be due to Alzheimer disease (AD), while 15.8% are considered to be due to vascular dementia (VaD). In Europe, about 3 million cases of AD could be due to 7 potentially modifiable risk factors: diabetes, midlife hypertension and/or obesity, physical inactivity, depression, smoking, and low educational level.
Aims:
To estimate the number of VaD cases in Europe and the number of AD and VaD cases in Italy attributable to these 7 potentially modifiable risk factors.
Methods:
Assuming the nonindependence of the 7 risk factors, the adjusted combined population attributable risk (PAR) was estimated for AD and VaD.
Results:
In Europe, adjusted combined PAR was 31.4% for AD and 37.8% for VaD. The total number of attributable cases was 3,033,000 for AD and 873,000 for VaD. In Italy, assuming a 20% reduction of the prevalence of each risk factor, adjusted combined PAR decreased from 45.2 to 38.9% for AD and from 53.1 to 46.6% for VaD, implying a 6.4 and 6.5% reduction in the prevalence of AD and VaD, respectively.
Conclusion:
A relevant reduction of AD and VaD cases in Europe and Italy could be obtained through primary prevention
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Microfluidic interactions between red blood cells and drug carriers by image analysis techniques
This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Blood is a complex biological fluid composed of deformable cells and platelets suspended in
plasma, a protein-rich liquid. The peculiar nature of blood needs to be considered when designing a drug
delivery strategy based on systemically administered carriers. Here, we report on an in vitro fluid dynamic
investigation of the influence of the microcapillary flow of red blood cells (RBCs) on micron sized carriers
by high speed imaging methods. The experiments were carried out in a 50ÎĽm diameter glass capillary that
mimicked the hydrodynamic conditions of human microcirculation. Spherical ÎĽ particles (ÎĽ-Ps), with sizes
ranging between 0.5 and 3ÎĽm, were tested. Images of the flowing RBCs and ÎĽ-Ps were acquired by a highspeed/ high-magnification microscopy. The transport and distribution of rigid particles in a suspension of
RBCs under shear flow were followed for: i) the migration of RBCs towards the vessel centerline due to
their deformability; ii) the cross-flow migration of ÎĽ-Ps towards the vessel wall due to their hydrodynamic
interactions with RBCs; iii) the radial distribution of ÎĽ-Ps in the presence of RBCs. This study suggests that
the therapeutic efficacy of ÎĽ-Ps could be ultimately affected by their interactions with the flowing RBCs in
the vasculature
PM2.5 Size Distribution and Characterization by Carbon Isotope in Tuscany (Italy)
This study is focused on the numerical distribution and isotopic description of PM2.5 developed within the PATOS II (Particolato Atmosferico TOScana) regional project about the characterization and source apportionment of atmospheric aerosol (PM2.5) in Tuscany. PM isotopic analysis can play an important role in the individuation of primary and secondary sources and also in the determination of the natural/biogenic or anthropogenic/combustion contribution to the measured concentration. In addition, the PM2.5 particle number concentrations and the relative contribution of ultrafine particles are interpreted to identify the emission sources, the main atmospheric processes and the factors related with the dispersion of atmospheric pollutants. The analytical results in term of δ13C parameter show a greater variability in the urban and suburban background sites than in the urban traffic site, where the δ13C parameter does not vary significantly: this could be strictly correlated with traffic emissions and independently from the total particles number. On the contrary, urban and suburban background sites are affected by the meteorology and atmospheric processes. For this reason we can observe a wider variability in the δ13C values due to the contribution of different emissions sources. Despite all, in urban background we can observe lower δ13C values related with high number of total particles; this effect could be related with a traffic emission transport, because the δ13C parameter is similar to the δ13C value of urban traffic site
General quasi-non-spreading linear three-dimensional wave-packets
We introduce a general approach for generation of sets of three-dimensional
quasi-non-spreading wavepackets propagating in linear media, also referred to
as linear light bullets. The spectrum of rigorously non-spreading wavepackets
in media with anomalous group velocity dispersion is localized on the surface
of a sphere, thus drastically restricting the possible wavepacket shapes.
However, broadening slightly the spectrum affords the generation of a large
variety of quasi-non-spreading distributions featuring complex topologies and
shapes in space and time that are of interest in different areas, such as
biophysics or nanosurgery. Here we discuss the method and show several
illustrative examples of its potential.Comment: 3 pages, 4 figures, to appear in Optics Letter
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Fourth Annual Progress Report on the Electrofluid Dynamic Wind Generator: Final Report for the Period 1 April 1979 - 31 August 1980
Conventional wind energy systems are limited in wind turbine diameter by allowable rotor stresses at power levels of several megawatts. In contrast, the Electrofluid Dynamic (EFD) wind driven generator has no fundamental limits on cross sectional area. It is a direct energy conversion device which employs unipolar charged particles transported by the wind against a retarding voltage gradient to a high potential. As no moving parts are exposed to the wind, extremely large power units may be feasible
Efficient magneto-optical trapping of a metastable helium gas
This article presents a new experiment aiming at BEC of metastable helium
atoms. It describes the design of a high flux discharge source of atoms and a
robust laser system using a DBR diode coupled with a high power Yb doped fiber
amplifier for manipulating the beam of metastable atoms. The atoms are trapped
in a small quartz cell in an extreme high vacuum. The trapping design uses an
additional laser (repumper) and allows the capture of a large number of
metastable helium atoms (approximately ) in a geometry favorable for
loading a tight magnetostatic trap.Comment: 12 pages, 7 figures, Late
Expansion of a coherent array of Bose-Einstein condensates
We investigate the properties of a coherent array containing about 200
Bose-Einstein condensates produced in a far detuned 1D optical lattice. The
density profile of the gas, imaged after releasing the trap, provides
information about the coherence of the ground-state wavefunction. The measured
atomic distribution is characterized by interference peaks. The time evolution
of the peaks, their relative population as well as the radial size of the
expanding cloud are in good agreement with the predictions of theory. The 2D
nature of the trapped condensates and the conditions required to observe the
effects of coherence are also discussed.Comment: 4 pages, 3 figure
Plasmas and Controlled Nuclear Fusion
Contains reports on three research projects.U. S. Atomic Energy Commission (Contract AT(11-1)-3070
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