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Sharaf, M. A.; Sharaf, Amr A.

doi:10.1023/a:1008223105130

Cited by 12 publications

(6 citation statements)

References 3 publications

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“…), is a probe virtually devoid of complications from background signal, and can be readily incorporated into proteins. [4][5][6][7] Fluorine-containing functional groups are ubiquitous in manmade organic molecules in diverse contexts: for example, 20-30 % of all pharmaceuticals currently on the market contain one or more fluorine atoms. 8 All these factors have contributed to the rapid growth of 19 F solid-state NMR applications, 3,[9][10][11][12][13][14] aided by the development of modern hardware and, most importantly, probes capable of delivering high MAS frequencies of 40 kHz and above.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Accurate Interfluorine Distances in Crystalline Organic Solids: A High-Frequency Magic Angle Spinning NMR Approach

et al. 2019

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Long-range interatomic distance restraints are critical for the determination of molecular structures by NMR spectroscopy, both in solution and in the solid state. Fluorine is a powerful NMR probe in a wide variety of contexts, owing to its favorable magnetic properties, ease of incorporation into biological molecules, and ubiquitous use in synthetic organic molecules designed for diverse applications. Due to the large gyromagnetic ratio of the 100% naturally abundant 19 F isotope, interfluorine distances as long as 20 Å are accessible in magic angle spinning (MAS) dipolar recoupling experiments. Herein, we present an approach for the determination of accurate interfluorine distances in multi-spin systems, using the finite pulse RFDR (fpRFDR) at high MAS frequencies of 40-60 kHz. We use a series of crystalline "molecular ruler" solids, difluorobenzoic acids and 7F-L-tryptophan, for which the intra-and intermolecular interfluorine distances are known. We describe the optimal experimental conditions for accurate distance determinations, including the choice of a phase cycle, the relative advantages of selective inversion 1D vs. 2D correlation experiments, and the appropriate numerical simulation protocols. A best strategy for the analysis of RFDR exchange curves in organic solids with extended spin interaction networks is presented, which, even in the absence of crystal structures, can be potentially incorporated into NMR structure determination.

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Section: Introductionmentioning

confidence: 99%

Measurement of Accurate Interfluorine Distances in Crystalline Organic Solids: A High-Frequency Magic Angle Spinning NMR Approach

et al. 2019

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“…This 1 H- 19 F distance technique is complementary to the recently introduced 13 C- 13 C resolved 13 C- 19 F distance experiment 22 , and yields more distance restraints than 19 F- 19 F 2D experiments [20][21] . Aromatic residues in proteins, particularly the sparse tryptophan (Trp) residues, can be fluorinated during protein expression without perturbing the structure [31][32] . Lipid-exposed Trp residues on the surfaces of membrane proteins can allow the investigation of ligand binding 33 and intermolecular assembly [34][35] , whereas Trp residues in the core of globular proteins can provide crucial constraints for the three-dimensional structure.…”

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confidence: 99%

High-Sensitivity Detection of Nanometer ¹H–¹⁹F Distances for Protein Structure Determination by ¹H-Detected Fast MAS NMR

2019

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Protein structure determination by solid-state NMR requires the measurement of many interatomic distances through dipole-dipole couplings. To obtain multiple long-range distance restraints rapidly and with high sensitivity, here we demonstrate a new 1 H-detected fast magicangle-spinning (MAS) NMR technique that yields many long distances in a 2D-resolved fashion. The distances are measured up to ~15 Å, with an accuracy of better than 10%, between 1 H and 19 F, two nuclear spins that have the highest gyromagnetic ratios. Exogenous fluorines are sparsely introduced into the aromatic residues of the protein, which is perdeuterated and back-exchanged to give amide protons. This 1 H-19 F distance experiment, termed 2D HSQC-REDOR, is demonstrated on the singly fluorinated model protein, GB1. We extracted 33 distances between 5-19 F-Trp43 and backbone amide protons, using 2D spectral series that were measured in less than 3 days. Combining these 1 H-19 F distance restraints with 13 C-19 F distances and chemical shifts, we calculated a GB1 structure with a backbone RMSD of 1.73 Å from the high-resolution structure. This 1 H-detected 1 H-19 F distance technique promises to provide a highly efficient tool for constraining the three-dimensional structures of proteins and protein-ligand complexes, with not only precise and fast measurements, but also access to truly long-range distances.

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“…18 Additionally, Fuks et al findings that the aesthetic pre-veneered crowns caused poor gingival health and ascribed these findings to the bulk of the veneer on the aesthetic crown, resulting in a thicker margin, complement these findings. 19 Similarly Sharaf A. et al 20 concluded that stainless steel crowns had no harmful effect on gingival health provided that good oral hygiene level was maintained.…”

Section: Gingival Indexmentioning

confidence: 99%

Clinical Evaluation of Zirconia and Stainless-Steel crowns in Primary Molars - A Randomized Control Trial

Nikhil

Krishnamoorthy

Sathyaprasad

et al. 2022

IJPedoR

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Background and Aim: Aesthetic alternatives to stainless steel crown for restoring primary molars attain a growing interest. The aim of the study was clinical evaluation and comparison of zirconia and stainless steel crown in primary molars (clinical and radiograph) Methods: A randomized controlled study was conducted on children of age group of 5 to 8 years of age visiting, KVG Dental College and Hospital, Sullia and who were meet the inclusion criteria of the study. The study population was randomly divided into two groups of 24 each. Group I: stainless steel crown, Group II: zirconia crown. Post endodontic tooth preparation was done and selected stainless steel and zirconia crowns followed by cemented using type 1 glass ionomer cement. The subjects was be recalled after 3, 6 and 9 months to check gingival index, oral hygiene index and bone health of the tooth using intraoral periapical radiograph. Results: There was significant increase in score of gingival index and OHI score for both SSC and zirconia crowns after 3 month followed by reduction in score at 6 and 9 months. There was no statistically significant difference in alveolar bone height in both groups (zirconia and SSCs) for 6 months. Conclusion: Zirconia crowns presented to be an excellent choice for primary posterior teeth full coverage restorations. Zirconia crowns performed better than SSCs in the aspect of gingival response and prevention of plaque adhesion. Keywords: zirconia crowns, stainless steel crown, primary molars, esthetics, dental caries.

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Cited by 12 publications

References 3 publications

Measurement of Accurate Interfluorine Distances in Crystalline Organic Solids: A High-Frequency Magic Angle Spinning NMR Approach

Measurement of Accurate Interfluorine Distances in Crystalline Organic Solids: A High-Frequency Magic Angle Spinning NMR Approach

High-Sensitivity Detection of Nanometer ¹H–¹⁹F Distances for Protein Structure Determination by ¹H-Detected Fast MAS NMR

Clinical Evaluation of Zirconia and Stainless-Steel crowns in Primary Molars - A Randomized Control Trial

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Untitled

Cited by 12 publications

References 3 publications

Measurement of Accurate Interfluorine Distances in Crystalline Organic Solids: A High-Frequency Magic Angle Spinning NMR Approach

Measurement of Accurate Interfluorine Distances in Crystalline Organic Solids: A High-Frequency Magic Angle Spinning NMR Approach

High-Sensitivity Detection of Nanometer 1H–19F Distances for Protein Structure Determination by 1H-Detected Fast MAS NMR

Clinical Evaluation of Zirconia and Stainless-Steel crowns in Primary Molars - A Randomized Control Trial

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High-Sensitivity Detection of Nanometer ¹H–¹⁹F Distances for Protein Structure Determination by ¹H-Detected Fast MAS NMR