1,200 research outputs found

    In vivo laser Doppler holography of the human retina

    Full text link
    The eye offers a unique opportunity for non-invasive exploration of cardiovascular diseases. Optical angiography in the retina requires sensitive measurements, which hinders conventional full-field laser Doppler imaging schemes. To overcome this limitation, we used digital holography to perform laser Doppler perfusion imaging of the human retina in vivo with near-infrared light. Wideband measurements of the beat frequency spectrum of optical interferograms recorded with a 39 kHz CMOS camera are analyzed by short-time Fourier transformation. Power Doppler images and movies drawn from the zeroth moment of the power spectrum density reveal blood flows in retinal and choroidal vessels over 512 ×\times 512 pixels covering 2.4 ×\times 2.4 mm2^2 on the retina with a 13 ms temporal resolution.Comment: 5 pages, 5 figure

    New Kids on the Blogs

    Full text link
    The article deals with of the phenomenon of Comic BlogsEtude du phénomène des blogs en bande dessinéePeer reviewe

    A Generalized Primitive Element Theorem

    Get PDF
    We deal with the following variant of the primitive element theorem: any commutative strongly separable extension of a commutative ring can be embedded in another one having primitive element. This statement holds for connected strongly separable extension of commutative rings which are either local or connected semilocal. We show that it holds for a more general family of rings, that is, for connected commutative rings whose quotient ring by the corresponding Jacobson radical is von Neumann regular and locally uniform. Some properties of the (connected) separable closure of such rings are also given as an application of this result.</p
    corecore