Abstract: Inorganic sheets (10) of at least two surperposed layers are provided with one or more symbols (20) which have a size of between 1 and 10 &mgr;m. The inorganic sheet is made up into pigment flakes (15). The symbols on the pigment flakes (15) allow a tracing of compositions such as printing inks or paintings and of substrates carrying such compositions.

Abstract: The present invention relates to coating compositions, preferably printing inks for security applications comprising at least one organic resin, at least one pigment and optionally at least one organic solvent. Said pigment comprises glass ceramic composite particles, containing at least one crystalline particle embedded in a glass matrix. Said glass ceramic particles have a particle size in the range of between 0.1 &mgr;m to 50 &mgr;m. Preferably active ions selected from the group of the rare-earth elements are incorporated into the crystalline phase of the composite to provide the glass ceramics with luminescent up- and down-converting characteristics. Glass ceramic luminescent have excellent physical and chemical stability. The glass matrix permits as well the stabilization of the photophysically interesting halide host crystals which have low phonon energies. Such materials provide unusual excitation and emission properties.

Abstract: In a method for magnetic resonance imaging, whereby magnetic resonance signals in a region of interest of an examination subject are generated in an examination by applying radio-frequency pulses of a first transmission field strength and the magnetic resonance signals are acquired in a spatially coded manner and allocated to volume elements of the region of interest in order to obtain one or more magnetic resonance images of the region of interest, the sensitivity of each volume element of the region of interest with respect to a modification of the first transmission field strength is determined, deviations of the first transmission field strength from a reference field strength are measured during the examination, and the magnetic resonance signals acquired in the examination are corrected on the basis of the sensitivity determined for each volume element and on the basis of the measured deviations of the first transmission field strength from the reference field strength.

Abstract: In a method for operating a magnetic resonance tomography system having a shim coil arrangement and a gradient coil arrangement, in which, in order to generate an image dataset of a region of an examination subject to be imaged, at least the region that is to be imaged is borne in an imaging volume of the system, an initial shim adjustment procedure is carried out, a change (if it occurs) in the position of the imaged region in relation to the imaging volume is detected, and a current in the shim coil arrangement is modified dependent on the detected position change.

Abstract: An ink composition containing at least two different types of optically variable pigments which produce a film or coating having a viewing angle dependent color shift.

Abstract: In a method for the operation of a magnetic resonance apparatus an anatomical image of a region of an examination subject to be imaged is generated with a prescribable resolution and quality, a functional image of the region to be imaged is generated, the functional image is superimposed on the anatomical image, and at least one area of the region to be imaged wherein the functional image contains unreliable information is identified in the superimposition.

Abstract: In a method for operating a magnetic resonance tomography system having a shim coil arrangement and a gradient coil arrangement, in which, in order to generate an image dataset of a region of an examination subject to be imaged, at least the region that is to be imaged is borne in an imaging volume of the system, an initial shim adjustment procedure is carried out, a change (if it occurs) in the position of the imaged region in relation to the imaging volume is detected, and a current in the shim coil arrangement is modified dependent on the detected position change.

Abstract: In a method for spatially resolved measurement of the electric activity of nerve cells by means of magnetic resonance, and a device for implementation of the method, a series of MR signal sets for the acquisition of spatially resolved MR signals is obtained, the phase shifts of the MR signals are determined, the phase shifts including shifts arising from magnetic field changes that are caused by the electric activity of nerve cells, and the event phase shifts of the MR signals are evaluated by a correlation of the MR signals with events that cause the electric activity.

Abstract: In a method for time-resolved and location-resolved presentation of functional brain activities with magnetic resonance and apparatus for the implementation of the method, the following control sequences are automatically implemented with a control unit on the basis of user inputs: generation of stimulation sequences for an examination subject, control of the data acquisition, post-processing and presentation of the data. A patient under examination can influence the control execution during the control execution.

Abstract: In an active electrical device with an electrical line for operation in the examination volume of a nuclear spin tomography device, a sheath wave trap tuned to the operating frequency of the nuclear spin tomography device is installed in the line.

Abstract: The present invention relates to inorganic particles comprising at least two chemical elements in a predefined and analytically identifiable ratio. These particles are used as a marking means incorporated into or applied onto any desired article. They provide a high security potential against counterfeiting since the analysis depend on a combination of spatial as well as of chemical information. In a first step the information containing particle has to be localized by scanning electron microscopy and in a second step the ratio of elements is analysed using energy—or wavelength—dispersive X-ray analysis (SEM/EDX).

Abstract: A coil arrangement for transcranial magnetic stimulation has several individual coils, each having separate current terminals, connected with a support element. The individual coils are constructed in a unitary structural component with a radio-frequency head antenna.

Abstract: In a method and apparatus for functional imaging an impulse sequence is used in which an examination subject is charged with a readout gradient with sub-pulses of alternating polarity. By means of at least two-dimensional Fourier transformation, an image data matrix having N rows is generated from the raw data thereby acquired. After a stimulation of the subject, a second image data matrix is acquired. The coincidence of opposed signal changes that occur at two pixels disposed from each other by a distance of N/2 rows in the image matrix is checked. Found coincidences are evaluated as functional activity.

Abstract: For shortening the measuring time to obtain an image identifying blood flow in a subject using magnetic resonance imaging, the number of phase-coding steps is reduced compared to a number of steps required for generating a quadratic observation window, given a constant, maximum amplitude of the phase-coding gradient. The reduction is to such an extent that only the blood vessel under observation is essentially acquired in phase-coding direction. Neighboring regions are saturated in order to avoid image artifacts. Given a correspondingly low number of phase-coding steps, a measurement of blood flow is possible in real-time presentation or, given an ECG triggered measuring sequence, a measurement of blood flow is possible in a greatly shortened overall measuring time.

Abstract: A pulse sequence is disclosed for operating a magnetic resonance system wherein a slice of the examination subject disposed perpendicularly to the flow in a vessel under examination is first selectively excited. A nuclear magnetic resonance signal is read out as an echo signal under the influence of a read-gradient disposed perpendicularly to the slice selection gradient. The signals acquired in successive steps are displayed on a time axis. In contrast to a conventional spin warp sequence, the phase coding gradient, and thus a topical resolution in one direction, are foregone, and instead a chronological resolution of the flow is achieved.