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1.
Nature ; 577(7792): E9, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31925404

RESUMEN

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

2.
Nature ; 568(7752): 382-386, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30962533

RESUMEN

Glaciers distinct from the Greenland and Antarctic ice sheets cover an area of approximately 706,000 square kilometres globally1, with an estimated total volume of 170,000 cubic kilometres, or 0.4 metres of potential sea-level-rise equivalent2. Retreating and thinning glaciers are icons of climate change3 and affect regional runoff4 as well as global sea level5,6. In past reports from the Intergovernmental Panel on Climate Change, estimates of changes in glacier mass were based on the multiplication of averaged or interpolated results from available observations of a few hundred glaciers by defined regional glacier areas7-10. For data-scarce regions, these results had to be complemented with estimates based on satellite altimetry and gravimetry11. These past approaches were challenged by the small number and heterogeneous spatiotemporal distribution of in situ measurement series and their often unknown ability to represent their respective mountain ranges, as well as by the spatial limitations of satellite altimetry (for which only point data are available) and gravimetry (with its coarse resolution). Here we use an extrapolation of glaciological and geodetic observations to show that glaciers contributed 27 ± 22 millimetres to global mean sea-level rise from 1961 to 2016. Regional specific-mass-change rates for 2006-2016 range from -0.1 metres to -1.2 metres of water equivalent per year, resulting in a global sea-level contribution of 335 ± 144 gigatonnes, or 0.92 ± 0.39 millimetres, per year. Although statistical uncertainty ranges overlap, our conclusions suggest that glacier mass loss may be larger than previously reported11. The present glacier mass loss is equivalent to the sea-level contribution of the Greenland Ice Sheet12, clearly exceeds the loss from the Antarctic Ice Sheet13, and accounts for 25 to 30 per cent of the total observed sea-level rise14. Present mass-loss rates indicate that glaciers could almost disappear in some mountain ranges in this century, while heavily glacierized regions will continue to contribute to sea-level rise beyond 2100.

3.
Gen Physiol Biophys ; 16(2): 175-88, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9437258

RESUMEN

Small-angle neutron scattering on large extruded unilamellar dimyristoyl phosphatidylcholine (DMPC) liposomes was used to determine the DMPC bilayer thickness dL and its change in the presence of N-lauryl-N,N-dimethylamine N-oxide (LDAO). At 36 degrees C, the values of dL are dL = 3.44 +/- 0.10 nm and dL = 2.90 +/- 0.10 nm in pure DMPC bilayers and in bilayers at DMPC:LDAO = 2:1 molar ratio, respectively. Using the specific volumes of DMPC and LDAO and supposing that the molecular volumes and surface areas in the bilayer are additive, the surface areas of DMPC (ADMPC) and of LDAO (ALDAO) were found to be at 36 degrees C: ADMPC = 0.644 +/- 0.018 nm2 and ALDAO = 0.25 +/- 0.05 nm2.


Asunto(s)
Dimetilaminas/farmacología , Dimiristoilfosfatidilcolina/química , Membrana Dobles de Lípidos/química , Tensoactivos/farmacología , Liposomas , Lípidos de la Membrana , Neutrones , Radiometría , Dispersión de Radiación , Propiedades de Superficie
4.
Med Tekh ; (2): 11-5, 2003.
Artículo en Ruso | MEDLINE | ID: mdl-12924214

RESUMEN

The "OFEKT-1" emission tomograph, worked out on the basis of gamma camera, is described. The results of technical and medical testing of the tomograph are presented.


Asunto(s)
Tomografía Computarizada de Emisión de Fotón Único/instrumentación , Cámaras gamma , Humanos , Tomografía Computarizada de Emisión de Fotón Único/economía
5.
Phys Chem Chem Phys ; 9(48): 6351-8, 2007 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-18060165

RESUMEN

We investigate the concentration and size dependent self-assembly of cadmium selenide nanoparticles at an oil/water interface. Using a pendant drop tensiometer, we monitor the assembly kinetics and evaluate the effective diffusion coefficients following changes in the interfacial tension for the early and late stages of nanoparticle adsorption. Comparison with the coefficients for free diffusion reveals the energy barrier for particle segregation to the interface. The formation of a nanoparticle monolayer at the oil/water interface is characterised by transmission electron microscopy.


Asunto(s)
Compuestos de Cadmio/química , Nanopartículas/química , Compuestos de Selenio/química , Tolueno/química , Adsorción , Compuestos de Cadmio/síntesis química , Difusión , Cinética , Microscopía Electrónica de Transmisión/métodos , Tamaño de la Partícula , Transición de Fase , Compuestos de Selenio/síntesis química , Tensión Superficial , Agua/química
6.
Med Radiol (Mosk) ; 32(10): 72-3, 1987 Oct.
Artículo en Ruso | MEDLINE | ID: mdl-2821339

RESUMEN

A brief consideration of the hardware and software of the automated control system for proton beam therapy in the clinicophysical complex at the JINR Laboratory of Nuclear Problems is presented.


Asunto(s)
Computadores , Radioterapia de Alta Energía/instrumentación , Humanos , Protones
7.
Med Radiol (Mosk) ; 33(1): 67-70, 1988 Jan.
Artículo en Ruso | MEDLINE | ID: mdl-2828817

RESUMEN

The first results of the formation and transportation of therapeutic proton beams at the JINR phasotron are presented. To ensure flat-top depth-dose distributions with a steep back slope, a method of forming a beam with a necessary energy spectrum from a non-monoenergic beam is employed. Extension of the flat hop of depth-dose distribution is 4.7 g/cm2 for a proton beam with the mean energy of 200 MeV.


Asunto(s)
Aceleradores de Partículas , Protones , Radioterapia de Alta Energía/instrumentación , Tecnología Radiológica
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