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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 176 for “"chemical shift"”.
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N.M.R. chemical shift imaging
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Medical Engineering and Medical Physics, 1984.
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Simultaneous multislice spiral and EPI chemical shift imaging
The current prominent excitation methods of 3D slabs used for MR Spectroscopy Imaging (MRSI) include long dead times in each TR. This dead time is necessary for magnetization moments' longitudinal relaxation, and so a good SNR efficiency. The fact that SNR is one of the dominant challenges that …
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Dynamic Chemical Shift Imaging For Image-Guided Thermal Therapy
… the water proton resonant frequency (PRF) shift. Calculation of the complex phase difference (CPD) is the method of choice for measuring the PRF indirectly since it facilitates temperature mapping with high spatiotemporal resolution. Chemical shift imaging (CSI) techniques can provide the …
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Quantitative 1H N.M.R. chemical shift imaging of neuronal content
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1994.
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The benefit of precise chemical shift and concentration referencing in NMR applications
… Magnetic Resonance (NMR) spectroscopy, the chemical shift and intensity of NMR signals provide critical information about a sample's molecular structure, reaction conditions, and material properties. For the precise determination of structures and properties, it is critical to know sample or …
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Präoperative Evaluierung von Transplantatnieren: Volumenselektive 31P-Magnet-Resonanz-Spektroskopie mittels Chemical Shift Imaging
… nicht <br>geeignet ist. Das Verfahren des Chemical Shift Imaging (CSI) erlaubt die Aufzeichnung von volumenselektiven 31P -Spektren. Hierbei wird unter Ausschluss des störenden Phosphates der <br>Perfusionslösung die gezielte Beurteilung von 31P –Spektren aus dem Nierengewebe möglich. Die …
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Prediction of proton and carbon-13 NMR chemical shifts using chemical shift prediction programs
… with one another to calculate predicted chemical shifts for a wide range of chemical compounds. 1H-spectra for several flexible and rigid organic compounds were acquired on Oxford-Broker spectrometer and interpreted using two-dimensional NMR techniques. ACD-V 4 and CHARGE-V7 programs were …
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Solid-State Magic-Angle Spinning NMR Methods for Tensor Measurements and Protein Structure Refinement Using Chemical Shift Tensors
… using solution NMR techniques, including chemical shift and dipolar tensors. Chemical shifts are the most fundamental parameters measured in NMR spectroscopy and have been leveraged for macromolecular structure determination, refinement and validation including details of active site …
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Improved magnetic resonance chemical shift imaging at 3 Tesla using a 32-channel integrated RF-shim coil array
In vivo chemical shift imaging is an imaging modality which uses the so-called chemical-shift phenomenon to quantitate brain metabolites spatially, therefore renders the study of brain metabolism and neurodegenerative diseases possible and eases diagnosis of tumors. However, the method is highly …
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Sequence Development and Expansion of Zero J-Modulation Echo-Planar Chemical Shift Imaging in Three Dimensions (3D ZJ-EPSI)
… a huge value. 3D Zero J-modulation Echo Planar Chemical Shift Imaging (3D ZJ-EPSI) is a fast MRS technique that can not only achieve all that was mentioned above, it can also provide additional detailed anatomical/pathological information due to its 3D nature. 3D ZJ-EPSI technique acquires …
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An NMR study of human brain tumours: Phosphorus chemical shift imaging in vivo and high resolution proton spectroscopy of biopsy samples.
… resonance (NMR). The localization technique, chemical shift imaging has been used to obtain phosphorus spectra of tumours in vivo. High resolution proton spectroscopy has been performed on biopsy samples and extracts of human brain tumours. To obtain the localized phosphorus spectra, one …
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The Ab Initio Calculation of the Chemical Shift Tensor and its Application for the Structure Determination in Ordered and Disordered Phases by Means of Solid-State Nuclear Magnetic Resonance
… this included the ab initio calculation of the chemical shift tensor which was taken for the simulation of various solid-state NMR experiments and the comparison to NMR measurements. In this context it was necessary to create a tool which could deal with the analysis of spin systems from …
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Ab initio calculations of NMR chemical shifts for structure determination in biology
… for calculating nuclear Magnetic Resonance chemical shifts to structure determination in Biology. We investigate and summarise the most important structural contributions to the chemical shift. Even though the NMR chemical shift has direct relation to the global structure it is shown that …
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Bioaktyviųjų joninių skysčių aukštosios skyros BMR tyrimas /
… temperature; low vapour pressure and their chemical structure can be altered. b-RTILs are different from the regular IL since b-RTILs are compatible with the human organism. That means, that b-RTIL can be used in medicine by increasing drug solubility in water. NMR spectroscopy is used to …
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Conformational Studies on Alicyclic Alcohols
… dependent. It is also known that the H chemical shift of an hydroxyl proton is dependent upon concentration. H NMR spectroscopy has therefore been used to study hydrogen-bonding in solution.<br/><br/>It was found previously by Becker, Liddel and Shoolery that at very high dilution in CC1 …
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Solid State NMR Relaxation Studies of Triosephosphate Isomerase
… Relaxation studies using the reorientation of a chemical shift tensor are applicable to a broader range of systems. Furthermore, solid state experiments do not require a change in the isotropic chemical shift as is necessary in solution NMR. We combined R1ρ measurements of the model compound …
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Extending the Boundaries of the Usage of NMR Chemical Shifts in Deciphering Biomolecular Structure and Dynamics
NMR chemical shifts have an extremely high information content on the behaviour of macromolecules, owing to their non-trivial dependence on myriads of structural and environmental factors. Although such complex dependence creates an initial barrier for their use for the characterisation of the …
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Structural studies of amyloid fibrils using solid-state NMR
… a new method of selective inversion based on chemical shift anisotropy is presented. An improved method for highly accurate distance measurement across parallel [beta]-sheets in amyloid fibrils has been developed. This method combines the a double quantum filtered version of the dipolar …
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