Abstract: An NMR (nuclear magnetic resonance) probe head has a microwave resonator with at least two elements which are reflective in the microwave range, at least one of which is focusing. The reflective elements at least partly delimit a resonance volume of the microwave resonator. At least one of the reflective elements is a DBR (“Distributed Bragg Reflector”), and the NMR probe head has at least one NMR coil integrated into the DBR. The NMR detection coil can thereby be positioned particularly near to the sample and the distortions of the static field by resonator components are reduced, such that the detection sensitivity and the spectral resolution of the experiment are significantly improved.

Abstract: A method for producing hyperpolarized sample material for use in magnetic resonance investigations involves preparing a target material containing high ? nuclei with a short T1, a polarizing agent with a broad EPR line, and low ? nuclei with a long T1. The polarizing agent in the target material is irradiated with microwave radiation, wherein the target material is at a cryogenic temperature and exposed to a static magnetic field B0?4.0 T, thus polarizing the high ? nuclei by DNP, and the polarization is transferred from the high ? nuclei to the low ? nuclei by Cross Polarization. A dissolved sample material is prepared containing the hyperpolarized low ? nuclei from the target material. Nuclei with a long longitudinal relaxation time T1 can thereby be quickly hyperpolarized to a high polarization level.

Abstract: A method for producing a hyperpolarized sample for use in a magnetic resonance investigation has the following steps: a) providing a solid sample (50), containing long T1 nuclei and short T1 nuclei in the same molecules (51); b) hyperpolarizing the short T1 nuclei in the solid sample (50); c) transforming the solid sample (50) into a liquid sample (52); and d) transferring the polarization of the short T1 nuclei to the long T1 nuclei within the molecules in the liquid sample (52) by Cross Polarization. The method can provide samples with hyperpolarized long T1 nuclei, in particular 13C or 15N, in a simple and efficient way.

Abstract: A method and apparatus for producing a hyperpolarized sample material for use in an NMR investigation provides for a cryogenic region having a target material containing a first hyperpolarizable nuclear species, a second hyperpolarizable nuclear species, and a nuclear spin polarizing agent, wherein the first nuclear species has a higher magnetic moment than the second nuclear species. Microwave energy is used to excite electron spin transitions in the polarizing agent in the presence of a magnetic field. The first hyperpolarizable nuclear species is thereby caused to interact with the electron spin system in the polarizing agent and generate hyperpolarization of at least the first nuclear species of the target material. The target material is then subjected to a lowered magnetic field, wherein the lowered magnetic field facilitates polarization transfer by nuclear thermal mixing between the species to thereby hyperpolarize the second nuclear species.

Abstract: An imaging system and method for imaging an immobilized object. The imaging system includes a support member adapted to receive the object in an immobilized state. The system also includes means for imaging the immobilized object in various imaging modes to capture images of the object. The imaging system further includes a movable phosphor screen. The phosphor screen is adapted to be movable without moving the immobilized object and support member.

Abstract: A calibration method for an MPI (=magnetic particle imaging) apparatus for conducting an MPI experiment, wherein the calibration method comprises m calibration MPI measurements with a calibration test piece and uses these measurements to create an image reconstruction matrix with which the signal contributions of N voxels within an investigation volume of the MPI apparatus are determined, wherein compressed sensing steps are applied in the calibration method with a transformation matrix that sparsifies the image construction matrix, and wherein only a number M<N of calibration MPI measurements for M voxels are carried out, from which the image reconstruction matrix is created and stored. This specifies an efficient method for determination of the system matrix for the MPI imaging method, which does not require much time to determine an MPI system function and nevertheless achieves a high degree of precision.

Abstract: A method for high resolution NMR (=nuclear magnetic resonance) measurements using the application of excitation pulses and the acquisition of data points, whereby a dwell time ?t separates the acquisition of two consecutive data points, which is characterized in that one or more tickling rf (=radio frequency) pulses of duration ?p are applied within each dwell time ?t, and that the average rf field amplitude of each of the tickling rf pulses approximately fulfills the condition ?1=?1?p/?t=?J wherein J is the scalar J-coupling constant and ?1=?B1 with ? being the gyromagnetic ratio and B1 being the strength of the magnetic component of each tickling rf pulse. This method is effective in decoupling homonuclear couplings.

Abstract: An RF resonator has a birdcage resonator with two electrically conducting ring elements (12, 33, 47) and N electrically conducting bars (11). At least one pair of electrically conducting ring segments (32a, 32b, 40, 43) forms an additional electrical connection between precisely two bars (11). The pair of ring segments (32a, 32b, 40, 43) define a current path (41, 42) with these two bars (11) which is capacitively interrupted at at least one point. The ring segments (32a, 32b, 40, 43) and the bars (11) electrically connected to the ring segments (32a, 32b, 40, 43) are disposed symmetrically with respect to the yz-plane. The field homogeneity and efficiency are thereby optimized even with frequencies that are far apart.

Abstract: A device for the high pressure densification of superconducting wire from compacted superconductor material or superconductor precursor powder particles, has four hard metal anvils (5, 6, 7, 8) with a total length (L2) parallel to the superconducting wire, the hard metal anvils borne in external independent pressure blocks (9, 10, 11), which are in turn either fixed or connected to high pressure devices, preferably hydraulic presses. At least one of the hard metal anvils is a free moving anvil (6) having clearances of at least 0.01 mm up to 0.2 mm towards the neighboring hard metal anvils (5, 8), so that no wall friction occurs between the free moving anvil and the neighboring anvils. This allows for high critical current densities Jc at reduced pressure applied to the hard metal anvils.

Abstract: A monitoring cell, used to perform a measurement in an NMR spectrometer of a reaction fluid produced by a reaction vessel, has a body having inlet and outlet transport coaxial capillaries for transporting the reaction fluid between the body and the reaction vessel. Cooling lines are also positioned coaxially with the transport capillaries to transport cooling liquid between the body and the reaction vessel. The cell further has a hollow sample probe for insertion into the NMR spectrometer and a coupler section that removably connects the sample probe to the body so that the inlet transport capillary extends through the body into the interior of the sample probe and the outlet transport capillary is sealed to the sample probe to allow reaction fluid that enters the sample probe via the inlet transport capillary to exit the sample probe via the outlet transport capillary.

Abstract: A torsional support apparatus is disclosed for craniocaudal rotation of test animals to enable multiple-view imaging. The animal is supported in a U-shaped loop of optically transparent material and the loop is moved to apply torsion to the animal to rotate it about its craniocaudal axis. Methods of imaging also are disclosed that use the torsional support technique.

Abstract: A method for determining the spatial distribution of magnetic resonance signals from at least one of N subvolumes predefines a reception encoding scheme and determines unique spatial encoding for at least one of the subvolumes but not for the entire volume under examination (UV). A transmission encoding scheme is also defined, wherein encoding is effected via the amplitude and/or phase of the transverse magnetization. The temporal amplitude and phase profile of the RF pulses is then calculated and each reception encoding step is carried out I times with variations according to the I transmission encoding steps in the transmission encoding scheme. The method makes it possible to largely restrict the spatially resolving MR signal encoding and image reconstruction to subvolumes of the object under examination without the achievable image quality sensitively depending on imperfections in the MR apparatus.

Abstract: An NMR (nuclear magnetic resonance) apparatus has a magnet system disposed in a cryostat (1), the cryostat having at least one nitrogen tank (3b) for receiving liquid nitrogen (5b) and a room temperature bore (7) for receiving an NMR probehead (8), wherein part(s) of the probehead or the overall probehead can be cooled to cryogenic temperatures by supplying liquid nitrogen (5b) via a supply line (14). The nitrogen tank (3b) of the cryostat (1) is connected to the NMR probehead (8) by means of a supply line (14) in such a fashion that liquid nitrogen (5b) is removed from the nitrogen tank (3b) and guided to the NMR probehead (8). The overall apparatus is therefore more compact, the operating comfort of the apparatus is increased, and the costs for acquisition, operation and maintenance are considerably reduced compared to previous comparable devices.

Abstract: A method of providing a material sample in a state favorable to retaining spin polarization includes cooling a material sample from a temperature above a freezing point of the material sample down to a second temperature below the freezing point of the material sample; maintaining the sample at about the second temperature for a period of about several hours; and reducing temperature of the material sample to a third temperature lower than the second temperature to provide the material sample in a state favorable to retaining spin polarization, where the steps of cooling, maintaining and reducing are performed in the absence of an adulterant material. The method of providing a sample of pyruvic acid in a state favorable to retaining spin polarization may include cooling the sample of pyruvic acid in the absence of an adulterant material from a temperature above a freezing point of the sample of pyruvic acid down to less than about 200 Kelvin to provide the sample.

Abstract: A method for performing magnetic resonance spectroscopy on solid samples containing nuclei of interest with spin quantum number I subjects the sample to a static magnetic field. The sample is spun at the magic angle and broad-band excitation of transverse magnetization of the nuclei of interest is effected by applying a first train of rotor-synchronized rf-pulses, having a carrier frequency, to the nuclei of interest with a pulse duration 0.1 ?s<?p<2 ?s, the first train of rf-pulses comprising k·n pulses extending over k rotor periods ?rot with n pulses per rotor period ?rot, wherein n is an integer n>1. Uniform excitation of a great number of spinning sidebands or families of sidebands that arise from large first-order quadrupole or hyperfine interactions is enabled and signal intensity is thereby improved.

Abstract: A sample container (2) for NMR measurements defines a volume (V) of sample substance. The sample container (2) has a first interface (G1) towards an environment (1) and a second interface (G2) towards the sample substance (3). A susceptibility jump at the second interface G2 is sufficiently large that the maximum value of |B?G2/B0| within the volume (V) is at least 0.5 ppm. The geometry of the sample container (2) is selected in such a fashion that, when a homogeneous magnetic field B0 has been applied, a location-dependent relative field change F is present in the volume (V), which is larger than 20 ppb at least at one point in a center partial volume (V1) and a first residual field (R1) in the center partial volume (V1) is smaller than 1.6 ppb. A second residual field (R2a) in the lower partial volume (V2a) is smaller than 30 ppb.

Abstract: The present invention relates to a loaded particle comprising at least one fluorescent dye, and in particular, a fluorescent dye with a large Stokes shift. The invention further relates to a method for producing an loaded latex particle, loaded with a fluorescent dye having a large stokes shift. In addition, the present invention relates to latex particles loaded with fluorescent dyes that are organic solvent soluble and insoluble in water. In a preferred embodiment, when the dyes are loaded into the water soluble latex particle, an increase is observed in quantum yield of fluorescence as compared to the quantum yield of the dye in aqueous solvent.

Abstract: An NMR measuring system with an NMR probehead has at least one cooling device (5a, b) generating a vibration spectrum of individual selective frequencies. The cooling device is mechanically connected to a vibration absorber (9a, 9b) having an oscillating mass element (27), whose resonance frequency is adjusted to the vibration frequency of the cooling device and/or to one of its harmonics. The cooling device has a cooling head which is thermally connected to an NMR resonator of the probehead via a flexible mechanical element. A vacuum housing of the probehead is designed in two parts which are mechanically connected via at least one damping element (30a-d). The lower part and the upper part of the vacuum housing are additionally mechanically flexibly connected to each other in a vacuum-tight fashion via a corrugated bellows (8a, 8b). The system minimizes sidebands in NMR spectra.

Abstract: A method for generating a desired temporal profile of the magnetization state in an object under examination (O) during an experiment involving magnetic resonance is characterized in that at least one spatially dependent change in the magnetization state inside the object under examination (O) is predefined and spatially selective radio-frequency pulses, which allow a simultaneous and independent change in the magnetization state at locations with different stipulations, are irradiated in order to implement the predefined spatially dependent change in the magnetization state. The method permits establishment of the same desired temporal profile of the magnetization state for different regions of the object under examination despite different given experimental parameters or deliberate generation of different desired profiles of the magnetization state at different locations.

Abstract: Temperature control device (20) for an NMR sample tube (22), wherein multiple interleaved, concentric flow channels (28, 31; 40, 41, 42; 50, 51) for temperature control fluid extending coaxially with respect to a cylindrical interior space (21) for holding the NMR sample tube are constituted around said interior space (21), wherein said temperature control device is constituted such that it is closed toward the interior space in an axial end region (26) and, an axial end region (23) at the opposite end thereto, open to the interior space for inserting the NMR sample tube into said interior space (21), wherein, in a counter flow region (GB), adjacent flow channels (28, 31; 40, 41, 42; 51) are interconnected through a fluid passage (34, 43, 44) at one axial end in such a way that the direction of a fluid flow in the flow channels of the counter flow region is reversed with respect to the corresponding adjacent flow channel in the counter flow region, wherein the outermost flow channel (28; 51) of the counter fl