LitCovid-sentences  

PMC:7594251 / 17379-18844 JSONTXT 5 Projects

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Id Subject Object Predicate Lexical cue
T121 0-6 Sentence denotes 2.1.3.
T122 7-17 Sentence denotes 1D 15N-NMR
T123 18-137 Sentence denotes In comparison to the previous example, 15N has a lower shift dispersion (~100ppm) than 13C, but higher than that of 1H.
T124 138-290 Sentence denotes Here, the situation is unfortunately severely limited due to an even lower natural abundance (0.37%) and a gyromagnetic ratio ~10 times smaller than 1H.
T125 291-372 Sentence denotes This means that 15N’s combined sensitivity is around 260,000 times lower than 1H.
T126 373-539 Sentence denotes As a result, isotopic enrichment of 15N combined with 1H-mediated enhancement via indirect detection is often needed in order to obtain a satisfactory 1D 15N spectra.
T127 540-617 Sentence denotes Similar to 13C, a few methods are available to overcome such low sensitivity.
T128 618-792 Sentence denotes One of them focuses on tagging molecules with carboxyl groups using 15N-ethanolamine and later detecting the signal using a 2D heteronuclear correlation NMR experiment [113].
T129 793-880 Sentence denotes Currently, novel approaches such as “smart isotope labeling” have been developed [114].
T130 881-1140 Sentence denotes Also, the SOFAST (Band-Selective Optimized Flip Angle Short Transient) technique can help but results in substantial hardware considerations/drawbacks and often increased concentrations, and/or dramatically longer experiments are still required [115,116,117].
T131 1141-1178 Sentence denotes Promising methods are on the horizon.
T132 1179-1465 Sentence denotes These methods include 15N heteronuclear signal enhancement via Signal Amplification by Reversible Exchange in SHield Enables Alignment Transfer to Heteronuclei (SABRE-SHEATH); however, more work and research are required before such methods can be applied for biomedical purposes [118].