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605 results on '"Wen, Yongqiang"'

1. Portable diamond maser with reduced magnetic field through orientation

Author

Ng, Wern, Wen, Yongqiang, Alford, Neil, and Arroo, Daan M.

Subjects
Quantum Physics, Condensed Matter - Materials Science, Physics - Applied Physics, Physics - Instrumentation and Detectors
Abstract

Masers have the potential to transform medical sensing and boost qubit readout detection due to their superb low-noise amplification. The negatively-charged nitrogen vacancy (NV-) diamond maser is the only continuous-wave solid-state maser discovered at room temperature, however it suffers from requiring large and bulky magnets which prevent its more widespread use. We present a significant reduction in size of the entire diamond maser using a much lighter and small-footprint electromagnet, reducing the weight from an immovable 2000 kilograms to a portable 30 kilograms. We achieve a maximum maser output power near -80 dBm, ten times higher than the first implementation, and have discovered techniques to reduce the magnetic field strength required for masing by precise manipulation of the spin orientation. With the diamond maser now shrunk to a size that can fit on a lab benchtop, we have brought continuous-wave room temperature masers away from the confines of research laboratories and closer to transforming readouts in quantum computing, frequency standards and quantum-limited medical sensing., Comment: 8 pages, 3 figures

Published
2024

2. `Maser-in-a-Shoebox': a portable plug-and-play maser device at room-temperature and zero magnetic-field

Author

Ng, Wern, Wen, Yongqiang, Attwood, Max, Jones, Daniel C, Oxborrow, Mark, Alford, Neil McN., and Arroo, Daan M.

Subjects
Quantum Physics, Condensed Matter - Materials Science, Physics - Applied Physics, Physics - Instrumentation and Detectors, Physics - Optics
Abstract

Masers, the microwave analogues of lasers, have seen a renaissance owing to the discovery of gain media that mase at room-temperature and zero-applied magnetic field. However, despite the ease with which the devices can be demonstrated under ambient conditions, achieving the ubiquity and portability which lasers enjoy has to date remained challenging. We present a maser device with a miniaturized maser cavity, gain material and laser pump source that fits within the size of a shoebox. The gain medium used is pentacene-doped in para-terphenyl and it is shown to give a strong masing signal with a peak power of -5 dBm even within a smaller form factor. The device is also shown to mase at different frequencies within a small range of 1.5 MHz away from the resonant frequency. The portability and simplicity of the device, which weighs under 5 kg, paves the way for demonstrators particularly in the areas of low-noise amplifiers, quantum sensors, cavity quantum electrodynamics and long-range communications.

Published
2023
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4. Exploring the Spin Dynamics of a Room-Temperature Diamond Maser using an Extended rate Equation Model

Author

Wen, Yongqiang, Diggle, Philip L., Alford, Neil McN., and Arroo, Daan M.

Subjects
Condensed Matter - Materials Science, Physics - Applied Physics, Physics - Instrumentation and Detectors
Abstract

Masers - the microwave analogue of lasers - are coherent microwave sources that can act as oscillators or quantum-limited amplifiers. Masers have historically required high vacuum and cryogenic temperatures to operate, but recently masers based on diamond have been demonstrated to operate at room temperature and pressure, opening a route to new applications as ultra-low noise microwave amplifiers. For these new applications to become feasible at a mass scale, it is important to optimise diamond masers by minimising their size and maximising their gain, as well as the maximum input power of signals that can be amplified. Here, we develop and numerically solve an extended rate equation model to present a detailed phenomenology of masing dynamics and determine the optimal properties required for the cavity, resonator and gain medium in order to develop portable maser devices. We conclude by suggesting how the material parameters of the diamond gain media and dielectric resonators used in diamond masers can be optimised and how rate equation models could be further developed to incorporate the effects of temperature and nitrogen concentration on spin lifetimes., Comment: 23 pages, 8 figures

Published
2023
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38. CRISPR/Cas13a-Responsive and RNA-Bridged DNA Hydrogel Capillary Sensor for Point-of-Care Detection of RNA

Author

Wang, Hui, Wang, Honghong, Pian, Hongru, Su, Fengxia, Tang, Fu, Chen, Desheng, Chen, Junjie, Wen, Yongqiang, Le, X. Chris, and Li, Zhengping

Abstract

Disease diagnostics and surveillance increasingly highlight the importance of portable, cost-effective, and sensitive point-of-care (POC) detection of nucleic acids. Here, we report a CRISPR/Cas13a-responsive and RNA-bridged DNA hydrogel capillary sensor for the direct and visual detection of specific RNA with high sensitivity. The capillary sensor was simply prepared by loading RNA-cross-linking DNA hydrogel film (∼0.2 mm ± 0.02 mm) at the end of a capillary. When CRISPR/Cas13a specifically recognizes the target RNA, the RNA bridge in the hydrogel film is cleaved by the trans-cleavage activity of CRISPR/Cas13a, increasing the permeability of the hydrogel film. Different concentrations of target RNA activate different amounts of Cas13a, cleaving different amounts of the RNA bridge in the hydrogel and causing corresponding changes in the permeability of the hydrogel. Therefore, samples containing different amounts of the target RNA travel to different distances in the capillary. Visual reading of the distance provides quantitative detection of the RNA target without the need for any nucleic acid amplification or auxiliary equipment. The technique was successfully used for the determination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in clinical nasopharyngeal (NP) swab and saliva samples. Easily quantifiable distance using a ruler eliminates the need for any optical or electrochemical detection equipment, making this assay potentially useful for POC and on-site applications.

Published
2024
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43. Double Bionic Deformable DNA Hydrogel Microneedles Loaded with Extracellular Vesicles to Guide Tissue Regeneration of Diabetes Ulcer Wound.

Author

Zhou, Liping, Zeng, Zehua, Liu, Jingchong, Zhang, Fengshi, Bian, Xiaochun, Luo, Zhiwei, Du, Hongwu, Zhang, Peixun, and Wen, Yongqiang

Subjects
EXTRACELLULAR vesicles, BIONICS, TISSUE adhesions, REGENERATION (Biology), DNA, POLYPEPTIDES, BLOOD sugar
Abstract

Due to the high blood glucose and low oxygen environment in diabetes wounds, complex pathological problems arise, such as failure to upregulate healing factors, biological barriers generation, microvascular lesions, and skin neuropathy. Inspired by nature and traditional Chinese paper‐cutting technology, polypeptide deoxyribonucleic acid (DNA) hydrogel microneedles (MNs) (P‐DNA gel MNs) are prepared. The obtained P‐DNA gel MNs possess optimized structure and large deformability, providing excellent clamping, stability, skin penetration, large deformation, tissue adhesion, and antibacterial properties. By incorporating extracellular vesicles (EVs) extracted under hypoxia (H‐EVs‐hypoxia), P‐DNA gel MNs can regulate tissue microenvironment, scavenge free radicals, and reduce inflammation. Notably, P‐DNA gel MNs integration system activates immune regulation and beneficial pathways, promoting neurogenesis and angiogenesis, reducing pathological pain, and achieving high‐quality healing. Overall, P‐DNA gel MNs system presents a fundamental mechanism for clinical transformation in treating diabetes wounds. [ABSTRACT FROM AUTHOR]

Published
2024
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