czas-i-pomiary: Nuclear magnetic resonance

Evidence: 77 • authority: 72

The Stark effect is the shifting and splitting of spectral lines of atoms and molecules due to the presence of an external electric field. It is the electric-field analogue of the Zeeman effect, where a spectral line is split into several components due to the presence of the magnetic field. Although initially coined for the static case, it is also used in the wider context to describe the effect of time-dependent electric fields. In particular, the Stark effect is responsible for the pressure broadening (Stark broadening) of spectral lines by charged particles in plasmas. For most spectral lines, the Stark effect is either linear (proportional to the applied electric field) or quadratic wi…

Evidence: 77 • authority: 72

Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are disturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a frequency characteristic of the magnetic field at the nucleus. This process occurs near resonance, when the oscillation frequency matches the intrinsic frequency of the nuclei, which depends on the strength of the static magnetic field, the chemical environment, and the magnetic properties of the isotope involved; in practical applications with static magnetic fields up to ca. 20 tesla, the frequency is similar to VHF and UHF television broadcasts (60–1000…

Evidence: 69 • authority: 88

Effect of the static magnetic field strength on parahydrogen induced polarization NMR spectra. Spin polarization transfer from parahydrogen (p-H2) to another molecular entity is generally thought to be mediated by longitudinal spin order (represented by the operator product IzAIzB, A and B being the two hydrogen nuclei which originate from p-H2 after a hydrogenation reaction). The longitudinal spin order leads to antiphase patterns in the proton NMR spectrum. In addition to these antiphase patterns, in-phase patterns, arising from polarization differences (represented by (IzA−IzB)), have been experimentally observed. A complete theory, based on a density operator treatment, has been worked…

Evidence: 52 • authority: 80

Peer Review Report For: Towards recognizing the mechanisms of effects evoked in living organisms by static magnetic field. Numerically simulated effects of the static magnetic field upon simple inorganic molecules. [version 1; peer review: 1 approved with res…

Evidence: 52 • authority: 80

4644473 Correction circuit for a static magnetic field of an NMR apparatus and NMR apparatus for utilizing the same

Evidence: 52 • authority: 92

Excitation of delocalized long-lived states of aliphatic protons at low and high magnetic fields.. Long-lived states (LLSs) can be excited in geminal protons of aliphatic chains by mono- or poly-chromatic spin-lock-induced crossings (SLICs), i.e., by application of one or more selective radio frequency (RF) fields, to create delocalized population imbalances between states belonging to different symmetry under spin permutations. At low fields (in this work at 1.4 T or 60 MHz for proton NMR), these experiments are challenging due to the proximity of the chemical shifts and the need to consider the full untruncated J -coupling Hamiltonian. Five molecules were studied in this work: ethanolamin…

Evidence: 52 • authority: 72

Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to form images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from computed tomography (CT) and positron emission tomography (PET) scans. MRI is a medical application of nuclear magnetic resonance (NMR), which can also be used for imaging in other NMR applications, such as NMR spectroscopy. MRI is widely used in hospitals and clinics for medical diagnosis, staging and follow-up of…

Evidence: 43 • authority: 80

4684893 Field gradient correction apparatus for compensating static field inhomogeneities in NMR imaging system

Evidence: 43 • authority: 80

Computational 59Co NMR Spectroscopy: Beyond Static Molecules

Evidence: 43 • authority: 92

Optimal control of spin systems.. Quantum optimal control has become a central tool for designing high-performance pulse sequences in magnetic resonance and quantum technologies. Early developments in NMR relied on heuristic composite and shaped pulses or analytical approaches such as average Hamiltonian theory. The introduction of modern optimal control algorithms enabled the systematic optimization of thousands of control parameters, greatly expanding the achievable performance and scope of pulse engineering. This review summarizes key developments in optimal control of spin and pseudo-spin systems and highlights major applications in magnetic resonance, in quantum technologies, and in th…

Evidence: 43 • authority: 92

Preparation and Evaluation of Docetaxel-Loaded Targeted Poly (β‑amino Ester) - Magnetic Nanoparticles for Chemo‑Magnetodynamic Therapy Under Low‑Frequency Magnetic Fields.. Background Magnetodynamic therapy (MDT), which utilizes the mechanical motion of magnetic nanoparticles (MNPs) under low-frequency magnetic fields (LFMFs), has emerged as a promising approach to overcome the major limitations of traditional chemotherapy. This study aims to evaluate an integrated therapeutic strategy, termed chemo-MDT, under in vitro conditions. Methods In this study, MNPs were modified with poly (β-amino ester) (PBAE) and functionalized with a CD44 aptamer for targeted delivery of docetaxel (DTX). The dr…

Evidence: 43 • authority: 92

High-frequency dynamic nuclear polarization in rotating solids.. Nuclear magnetic resonance (NMR) spectroscopy is among the most powerful tools for determining molecular structure, yet its intrinsic sensitivity has long constrained what can be studied. Dynamic nuclear polarization (DNP) addresses this fundamental limitation by transferring the much larger polarization of electron spins to nearby nuclei, amplifying NMR signals by several orders of magnitude. When combined with magic angle spinning (MAS), a technique that averages anisotropic interactions in solid samples to yield high-resolution spectra, DNP transforms solid-state NMR into a practical tool for investigating complex biologica…