Purpose Dynamic glucose enhanced (DGE) MRI has shown potential for imaging glucose delivery and blood–brain barrier permeability at fields of 7T and higher. Here, we evaluated issues involved with translating d‐glucose weighted chemical exchange saturation transfer (glucoCEST) experiments to the clinical field strength of 3T. Methods Exchange rates of the different hydroxyl proton pools and the field‐dependent T2 relaxivity of water in d‐glucose solution were used to simulate the water saturation spectra (Z‐spectra) and DGE signal differences as a function of static field strength B0, radiofrequency field strength B1, and saturation time tsat. Multislice DGE experiments were performed at 3T on 5 healthy volunteers and 3 glioma patients. Results Simulations showed that DGE signal decreases with B0, because of decreased contributions of glucoCEST and transverse relaxivity, as well as coalescence of the hydroxyl and water proton signals in the Z‐spectrum. At 3T, because of this coalescence and increased interference of direct water saturation and magnetization transfer contrast, the DGE effect can be assessed over a broad range of saturation frequencies. Multislice DGE experiments were performed in vivo using a B1 of 1.6 µT and a tsat of 1 second, leading to a small glucoCEST DGE effect at an offset frequency of 2 ppm from the water resonance. Motion correction was essential to detect DGE effects reliably. Conclusion Multislice glucoCEST‐based DGE experiments can be performed at 3T with sufficient temporal resolution. However, the effects are small and prone to motion influence. Therefore, motion correction should be used when performing DGE experiments at clinical field strengths.

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Proton magnetic resonance spectroscopy ( 1 H MRS) of biological systems has higher specificity than MRI because resonances of multiple metabolites can be distinguished, reflecting chemistry and physiology in situ. Unfortunately, this approach has very low sensitivity as the metabolites are typically at millimolar concentrations compared to the molar signal strength of water-based MRI. As a consequence, even though 1 H MRS is a powerful and common research tool, its inroad into daily clinical practice has been limited. Until very recently, 1 H MRS applications have focused on the resonances upfield (i.e., at lower frequency) of the water resonance. This article deals with protons that are generally not observed in a typical water-suppressed spectrum, namely, the exchangeable protons found predominantly downfield from water. These can usually be detected by MRS only if the transfer of water proton saturation (established during water suppression) is not a confounding factor, or by using water exchange (WEX) spectroscopy, in which RF labeling of the water protons is transferred to the exchangeable protons and subsequently detected. More importantly, it has recently become clear that the presence of such exchangeable protons on low concentration solute molecules can be detected via the water signal by RF labeling of these protons and subsequent transfer of this label to water protons. This process, leading to saturation of the water signal and enhancement of the effect through repeated exchange, can be used for the imaging of metabolite signals or exchangeable-proton-based contrast agents with enhanced sensitivity. This has given rise to the field of chemical exchange saturation transfer (CEST) MRI, which has greatly increased the potential for translating spectroscopic methods to the clinic. Examples include the measurement of pH, temperature, and enzyme activity as well as detection of cellular metabolites, ions, and proteins and peptides. In addition, bio-organic compounds can now be used for contrast agents, cell and nanoparticle labeling, and reporter genes.

3-OMG shows a CEST contrast enhancement that is approximately twice as much as that of D-glucose for a similar tumor line. In view of its suggested low toxicity and transport properties across the BBB, 3-OMG provides an option to be used as a nonmetallic contrast agent for evaluating brain tumors.

Para-water is an analogue of para-hydrogen, where the two proton spins are in a quantum state that is antisymmetric under permutation, also known as singlet state. The populations of the nuclear spin states in para-water are believed to have long lifetimes just like other Long-Lived States (LLSs). This hypothesis can be verified by measuring the relaxation of an excess or a deficiency of para-water, also known as a "Triplet-Singlet Imbalance" (TSI), i.e., a difference between the average population of the three triplet states T (that are symmetric under permutation) and the population of the singlet state S. In analogy with our recent findings on ethanol and fumarate, we propose to adapt the procedure for Dissolution Dynamic Nuclear Polarization (D-DNP) to prepare such a TSI in frozen water at very low temperatures in the vicinity of 1.2 K. After rapid heating and dissolution using an aprotic solvent, the TSI should be largely preserved. To assess this hypothesis, we studied the lifetime of water as a molecular entity when diluted in various solvents. In neat liquid H2O, proton exchange rates have been characterized by spin-echo experiments on oxygen-17 in natural abundance, with and without proton decoupling. One-dimensional exchange spectroscopy (EXSY) has been used to study proton exchange rates in H2O, HDO and D2O mixtures diluted in various aprotic solvents. In the case of 50 mM H2O in dioxane-d8, the proton exchange lifetime is about 20 s. After dissolving, one can observe this TSI by monitoring intensities in oxygen-17 spectra of H2O (if necessary using isotopically enriched samples) where the AX2 system comprising a "spy" oxygen A and two protons X2 gives rise to binomial multiplets only if the TSI vanishes. Alternatively, fast chemical addition to a suitable substrate (such as an activated aldehyde or ketone) can provide AX2 systems where a carbon-13 acts as a spy nucleus. Proton signals that relax to equilibrium with two distinct time constants can be considered as a hallmark of a TSI. We optimized several experimental procedures designed to preserve and reveal dilute para-water in bulk.

Two-dimensional (2D) Fourier transform ion cyclotron resonance (FT-ICR) offers an approach to mass spectrometry (MS) that pursuits similar objectives as MS/MS experiments. While the latter must focus on one ion species at a time, 2D FT ICR can examine all possible correlations due to ion fragmentation in a single experiment: correlations between precursors, charged and neutral fragments. We revisited the original 2D FT-ICR experiment that has hitherto fallen short of stimulating significant analytical applications, probably because it is technically demanding. These shortcomings can now be overcome by improved FT-ICR instrumentation and computer hard- and software. We seek to achieve a better understanding of the intricacies of the behavior of ions during a basic two-dimensional ICR sequence comprising three simple monochromatic pulses. Through simulations based on Lorentzian equations, we have mapped the ion trajectories for different pulse durations and phases.

Owing to its imidazole side chain, histidine participates in various processes such as enzyme catalysis, pH regulation, metal binding, and phosphorylation. The determination of exchange rates of labile protons for such a system is important for understanding its functions. However, these rates are too fast to be measured directly in an aqueous solution by using NMR spectroscopy. We have obtained the exchange rates of the NH3+ amino protons and the labile NHε2 and NHδ1 protons of the imidazole ring by indirect detection through nitrogen-15 as a function of temperature (272 K

A BSTRACT Introduction: It is likely that a pregnant woman is more motivated and receptive to accepting healthy habits and practices if talked about the benefits to the fetus. When explained about the harmful effects of tobacco on the health of the baby, the mother can be encouraged to modify her tobacco consumption habits and work toward quitting tobacco. Aim: Our aim was to study the effectiveness of brief counseling (5As)—Antenatal Tobacco Cessation Support Program among pregnant women availing antenatal care (ANC). Methodology: A quasi-randomized study design was used to conduct the study. The participants were identified by screening during ANC visits, and women consuming tobacco were subjected to detailed history taking and very brief counseling with the help of 5A’s framework. Results: We found that Mishri was the commonest form of tobacco consumed by these women. Around 93.33% of the women consume Mishri, followed by 6.66% of women consuming chewing tobacco. The method of brief counseling made an impact in the cessation of tobacco consumption in 13.37% of the study subjects. Conclusion: We conclude that the use of brief counseling and motivational interviewing is feasible in most settings without inhibiting the other important aspects of ANC or disrupting the patient flow.