HP acquisition methods: pulse sequences, reconstruction, and RF coils

Using electron spins within molecules for quantum information processing (QIP) was first proposed by Leuenberger and Loss (1), who showed how the Grover algorithm could be mapped onto a Mn12 cage (2). Since then several groups have examined two-level (S = ½) molecular spin systems as possible qubits (3-12). There has also been a report of the implementation of the Grover algorithm in a four-level molecular qudit (13). A major challenge is to protect the spin qubit from noise that causes loss of phase information; strategies to minimize the impact of noise on qubits can be categorized as corrective, reductive, or protective. Corrective approaches allow noise and correct for its impact on the qubit using advanced microwave pulse sequences (3). Reductive approaches reduce the noise by minimising the number of nearby nuclear spins (7-11), and increasing the rigidity of molecules to minimise the effect of vibrations (which can cause a fluctuating magnetic field via spin-orbit coupling) (9,11); this is essentially engineering the ligand shell surrounding the electron spin. A protective approach would seek to make the qubit less sensitive to noise: an example of the protective approach is the use of clock transitions to render spin states immune to magnetic fields at first order (12). Here we present a further protective method that would complement reductive and corrective approaches to enhancing quantum coherence in molecular qubits. The target is a molecular spin qubit with an effective 2S ground state: we achieve this with a family of divalent rare-earth molecules that have negligible magnetic anisotropy such that the isotropic nature of the electron spin renders the qubit markedly less sensitive to magnetic noise, allowing coherent spin manipulations even at room temperature. If combined with the other strategies, we believe this could lead to molecular qubits with substantial advantages over competing qubit proposals.<br>

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Optimization of Parameters of RF Pulse Sequences for MRI Investigations in the Presence of Magnetic Nanoparticles

Technical Physics ◽

10.1134/s106378422009008x ◽

2020 ◽

Vol 65 (9) ◽

pp. 1416-1420

Author(s):

Yu. V. Bogachev ◽

A. V. Nikitina ◽

V. V. Frolov ◽

Ya. Yu. Marchenko ◽

B. P. Nikolaev

Keyword(s):

Magnetic Nanoparticles ◽

Pulse Sequences ◽

Optimization Of Parameters ◽

Rf Pulse

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Arbitrarily Accurate Pulse Sequences for Robust Dynamical Decoupling

Physical Review Letters ◽

10.1103/physrevlett.118.133202 ◽

2017 ◽

Vol 118 (13) ◽

Cited By ~ 23

Author(s):

Genko T. Genov ◽

Daniel Schraft ◽

Nikolay V. Vitanov ◽

Thomas Halfmann

Keyword(s):

Pulse Sequences ◽

Dynamical Decoupling

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BIRD-J -resolved HMBC and BIRD-high-resolution HMBC pulse sequences for measuring heteronuclear long-range coupling constants and proton-proton spin coupling constants in complicated spin systems

Magnetic Resonance in Chemistry ◽

10.1002/mrc.2702 ◽

2011 ◽

Vol 49 (2) ◽

pp. 53-58 ◽

Cited By ~ 9

Author(s):

Kazuo Furihata ◽

Mitsuru Tashiro ◽

Haruo Seto

Keyword(s):

High Resolution ◽

Long Range ◽

Pulse Sequences ◽

Spin Systems ◽

Proton Spin ◽

Coupling Constants ◽

Spin Coupling ◽

Proton Proton ◽

Spin Coupling Constants

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Solid State NMR Spectroscopy a Valuable Technique for Structural Insights of Advanced Thin Film Materials: A Review

Nanomaterials ◽

10.3390/nano11061494 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1494

Author(s):

Mustapha El Hariri El Nokab ◽

Khaled O. Sebakhy

Keyword(s):

Thin Film ◽

Thin Films ◽

Solid State ◽

Solid State Nmr ◽

Pulse Sequences ◽

3D Structure ◽

Spectroscopic Techniques ◽

Film Research ◽

Versatile Technique ◽

Work Done

Solid-state NMR has proven to be a versatile technique for studying the chemical structure, 3D structure and dynamics of all sorts of chemical compounds. In nanotechnology and particularly in thin films, the study of chemical modification, molecular packing, end chain motion, distance determination and solvent-matrix interactions is essential for controlling the final product properties and applications. Despite its atomic-level research capabilities and recent technical advancements, solid-state NMR is still lacking behind other spectroscopic techniques in the field of thin films due to the underestimation of NMR capabilities, availability, great variety of nuclei and pulse sequences, lack of sensitivity for quadrupole nuclei and time-consuming experiments. This article will comprehensively and critically review the work done by solid-state NMR on different types of thin films and the most advanced NMR strategies, which are beyond conventional, and the hardware design used to overcome the technical issues in thin-film research.

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Developing a Specific MRI Technology to Identify Complications Caused by Breast Implants

Applied Sciences ◽

10.3390/app11083434 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3434

Author(s):

Ming-Fang Lin ◽

Lu-Han Lai ◽

Wen-Tien Hsiao ◽

Melissa Min-Szu Yao ◽

Wing-P Chan

Keyword(s):

Water Saturation ◽

Spin Echo ◽

Pulse Sequences ◽

Breast Implants ◽

Fast Spin Echo ◽

Silicone Implants ◽

Water Suppression ◽

Dynamic Contrast Enhancement ◽

Produce Water ◽

Fat Saturation

With advancements in aesthetic medicine, breast augmentation has become a popular plastic surgery worldwide, typically performed using either fine-needle injection or silicone implants. Both carry complication risks from rupture over time. In this study, we aimed to reduce misjudgments and increase diagnostic value by developing an MRI technique that can produce water- and silicone-specific images from MRI scans of phantoms (Natrelle® saline-filled breast implants) and human bodies. Pig oil, soybean oil, and normal saline were used to simulate human breast tissue, and two common types of breast implants, saline bags, and silicone bags, were selected as well, resulting in five materials scanned. Six pulse sequences were applied: T1W fast spin echo (FSE), T1W SPGR/60, T2W, T2W fat-saturation, STIR, and STIR water-saturation. Human body scans were additionally investigated using 3D SPGR fat-saturation dynamic contrast enhancement. Results show that the best way to enhance tissue contrast in images of silicone implants is to apply STIR combined with water suppression, and the best way to enhance saline bag implants is to apply T2W fat-saturation combined with fat suppression. Both offered very high sensitivity and specificity, rendering this method especially useful for distinguishing normal mammary glands from siliconoma.

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Comparison of 2D Fat Suppressed Proton Density (FS-PD) and 3D (WATS-c) MRI pulse sequences in evaluation of chondromalacia patellae

Egyptian Journal of Radiology and Nuclear Medicine ◽

10.1186/s43055-019-0102-z ◽

2019 ◽

Vol 50 (1) ◽

Author(s):

Ahmed Ibrahim Tawfik ◽

Wael Hamza Kamr ◽

Saher Ebrahim Taman

Keyword(s):

Diagnostic Performance ◽

False Negative ◽

Pulse Sequences ◽

Proton Density ◽

Grading System ◽

Reference Standard ◽

Mr Images ◽

Arthroscopic Findings ◽

Chondromalacia Patella ◽

Sensitivity Specificity

Abstract Background Comparing the diagnostic performance of widely used 2D FSE technique (fat-suppressed proton density; FS-PD) and the 3D technique (water-selective cartilage scan; WATS-c) in evaluation of the chondromalacia patella by using arthroscopy as reference standard Results Seventy-five adult patients were enrolled in this study. They underwent MRI examinations then arthroscopy done in 2–4 days after it. MRI was done using 2D (FS-PD) and 3D (WATS-c) sequences and MR images were compared by two radiologists separately, then grading of the cartilage lesions was performed according to modified Noyes grading system and comparison between grade 0–1, 2, and 3 lesions was done using arthroscopic findings as a reference. A false-negative result is considered if there was undergrading of chondromalacia and false-positive result if chondromalacia was overgraded. Each sequence sensitivity, specificity, and accuracy was calculated by both readers. For reader 1, the sensitivity is 69% for WATS-c and 80% for FS-PD and the accuracy is 90% for WATS-c and 92% for FS-PD and for reader 2, the sensitivity is 56% for WATS-c and 84% for FS-PD and the accuracy is 88% for WATS-c and 94% for FS-PD. Conclusion 2D FS-PD images showed better diagnostic performance than 3D WATS-c images for evaluating chondromalacia patella.

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