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3,086 results on '"Shen, Qian"'

1. Proof of 5D $A_n$ AGT conjecture at $\beta=1$

Author

Shen, Qian, Huang, Zi-Hao, Hu, Shao-Ping, Yuan, Qing-Jie, and Zhang, Kilar

Subjects
High Energy Physics - Theory, Mathematical Physics
Abstract

In this paper, we give a proof of 5D $A_n$ AGT conjecture at $\beta=1$, where the gauge theory side is one dimension higher than the original 4D case, and corresponds to the q-deformation of the 2D conformal field theory side. We define a q-deformed $A_n$ Selberg integral, which generalizes the $A_n$ Selberg integral and the q-deformed $A_1$ Selberg integral in the literature. A q-deformed $A_n$ Selberg average formula with $n+1$ Schur polynomials is proposed and proved to complete the proof., Comment: 19 pages; v2: published version, with the conjecture for the q-deformed $A_n$ Selberg average formula of $n+1$ Schur polynomials proved

Published
2024
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4. IPNA clinical practice recommendations for the diagnosis and management of children with IgA nephropathy and IgA vasculitis nephritis

Author

Vivarelli, Marina, Samuel, Susan, Coppo, Rosanna, Barratt, Jonathan, Bonilla-Felix, Melvin, Haffner, Dieter, Gibson, Keisha, Haas, Mark, Abdel-Hafez, Maher Ahmed, Adragna, Marta, Brogan, Paul, Kim, Siah, Liu, Isaac, Liu, Zhi-Hong, Mantan, Mukta, Shima, Yuko, Shimuzu, Masaki, Shen, Qian, Trimarchi, Hernan, Hahn, Deirdre, Hodson, Elisabeth, Pfister, Ken, Alladin, Areefa, Boyer, Olivia, and Nakanishi, Koichi

Published
2024
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5. A TNIP1-driven systemic autoimmune disorder with elevated IgG4

Author

Medhavy, Arti, Athanasopoulos, Vicki, Bassett, Katharine, He, Yuke, Stanley, Maurice, Enosi Tuipulotu, Daniel, Cappello, Jean, Brown, Grant J., Gonzalez-Figueroa, Paula, Turnbull, Cynthia, Shanmuganandam, Somasundhari, Tummala, Padmaja, Hart, Gemma, Lea-Henry, Tom, Wang, Hao, Nambadan, Sonia, Shen, Qian, Roco, Jonathan A., Burgio, Gaetan, Wu, Phil, Cho, Eun, Andrews, T. Daniel, Field, Matt A., Wu, Xiaoqian, Ding, Huihua, Guo, Qiang, Shen, Nan, Man, Si Ming, Jiang, Simon H., Cook, Matthew C., and Vinuesa, Carola G.

Published
2024
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12. Nicotine use during late adolescence and young adulthood is associated with changes in hippocampal volume and memory performance

Author

Happer, Joseph P, Courtney, Kelly E, Baca, Rachel E, Andrade, Gianna, Thompson, Courtney, Shen, Qian, Liu, Thomas T, and Jacobus, Joanna

Subjects
Biomedical and Clinical Sciences, Biological Psychology, Psychology, Paediatrics, Pharmacology and Pharmaceutical Sciences, Pediatric, Behavioral and Social Science, Brain Disorders, Mental Health, Cannabinoid Research, Neurosciences, Drug Abuse (NIDA only), Basic Behavioral and Social Science, Substance Misuse, Mental health, Neurological, Good Health and Well Being, hippocampus, memory, nicotine, vaping, adolescence, young adult, Cognitive Sciences, Biological psychology
Abstract

BackgroundWith the advent of electronic nicotine delivery systems, the use of nicotine and tobacco products (NTPs) among adolescents and young adults remains high in the US. Use of e-cigarettes additionally elevates the risk of problematic use of other substances like cannabis, which is often co-used with NTPs. However, their effects on brain health, particularly the hippocampus, and cognition during this neurodevelopmental period are poorly understood.MethodsHealthy late adolescents/young adults (N = 223) ages 16-22 completed a structural MRI to examine right and left hippocampal volumes. Memory was assessed with the NIH Toolbox Picture Sequence Memory Test (PSMT) and Rey Auditory Verbal Learning Test (RAVLT). Cumulative 6-month NTP and cannabis episodes were assessed and modeled continuously on hippocampal volumes. Participants were then grouped based on 6-month NTP use to examine relationships with the hippocampus and memory: current users (CU) endorsed weekly or greater use; light/abstinent users (LU) endorsed less than weekly; and never users (NU).ResultsNTP use predicted larger hippocampal volumes bilaterally while cannabis use had no impact nor interacted with NTP use. For memory, larger left hippocampal volumes were positively associated with PSMT performance, RAVLT total learning, short delay and long delay recall for the NU group. In contrast, there was a negative relationship between hippocampal volumes and performances for LU and CU groups. No differences were detected between NTP-using groups.ConclusionThese results suggest that the hippocampus is sensitive to NTP exposure during late adolescence/young adulthood and may alter typical hippocampal morphometry in addition to brain-behavior relationships underlying learning and memory processes.

Published
2024

13. The Combined Effects of Nicotine and Cannabis on Cortical Thickness Estimates in Adolescents and Emerging Adults

Author

Mejia, Margie Hernandez, Courtney, Kelly E, Wade, Natasha E, Wallace, Alexander, Baca, Rachel E, Shen, Qian, Happer, Joseph Patrick, and Jacobus, Joanna

Subjects
Biological Psychology, Pharmacology and Pharmaceutical Sciences, Biomedical and Clinical Sciences, Psychology, Substance Misuse, Drug Abuse (NIDA only), Neurosciences, Clinical Research, Tobacco, Pediatric, Prevention, Behavioral and Social Science, Cannabinoid Research, 2.2 Factors relating to the physical environment, Neurological, Mental health, Good Health and Well Being, adolescence, young adults, nicotine, cannabis, cortical thickness, Cognitive Sciences, Applied and developmental psychology, Biological psychology
Abstract

Early life substance use, including cannabis and nicotine, may result in deleterious effects on the maturation of brain tissue and gray matter cortical development. The current study employed linear regression models to investigate the main and interactive effects of past-year nicotine and cannabis use on gray matter cortical thickness estimates in 11 bilateral independent frontal cortical regions in 223 16-22-year-olds. As the frontal cortex develops throughout late adolescence and young adulthood, this period becomes crucial for studying the impact of substance use on brain structure. The distinct effects of nicotine and cannabis use status on cortical thickness were found bilaterally, as cannabis and nicotine users both had thinner cortices than non-users. Interactions between nicotine and cannabis were also observed, in which cannabis use was associated with thicker cortices for those with a history of nicotine and tobacco product (NTP) use in three left frontal regions. This study sheds light on the intricate relationship between substance use and brain structure, suggesting a potential modulation of cannabis' impact on cortical thickness by nicotine exposure, and emphasizing the need for further longitudinal research to characterize these interactions and their implications for brain health and development.

Published
2024

21. Unidirectional guided-wave-driven metasurfaces for arbitrary wavefront control

Author

Li, Shiqing, Tsakmakidis, Kosmas L., Jiang, Tao, Shen, Qian, Zhang, Hang, Yan, Jinhua, Sun, Shulin, and Shen, Linfang

Subjects
Physics - Optics, Physics - Applied Physics
Abstract

Metasurfaces, composed of subwavelength electromagnetic microstructures, known as meta-atoms, are capable of reshaping the wavefronts of incident beams in desired manners, making them great candidates for revolutionizing conventional optics. However, the requirement for external light excitation and the resonant nature of meta-atoms make it difficult to fully integrate metasurfaces on-chip or to control wavefronts at deep-subwavelength scales. Here, we introduce the concept and design of a new class of metasurfaces, driven by unidirectional guided waves, and being capable of arbitrary wavefront control based on the unique dispersion properties of unidirectional guided waves rather than resonant meta-atoms. Upon experimentally demonstrating the feasibility and practicality of the unidirectional nature of our designs in the microwave regime, we numerically validate this new principle through the design of several microwave meta-devices using metal-air-gyromagnetic unidirectional surface magnetoplamons, agilely converting unidirectional guided modes into the wavefronts of 3D Bessel beams, focused waves, and controllable vortex beams. We also numerically demonstrate sub-diffraction focusing, which is currently beyond the capability of conventional metasurfaces. Furthermore, we directly show how these concepts can be transferred to the terahertz regime, and discuss their feasibility in the optical domain, too. Based on this nonresonant (that is, broadband) mechanism and on standard plasmonic platforms, our metasurfaces can be integrated on-chip, enabling the manipulation of electromagnetic waves on deep subwavelength scales and over wide frequency ranges, thereby opening up new opportunities for applications in communications, remote sensing, displays, and so forth.

Published
2023

23. Realization of a photonic topological insulator in Kagome crystals at terahertz wavelengths

Author

Shen, Yun, Ji, Jie, Zhang, Le, Jepsen, Peter Uhd, Yu, Xin, Yan, Shubin, Li, Huichang, Shen, Qian, Madhi, Daena, Zhou, Binbin, and Deng, Xiaohua

Subjects
Physics - Optics
Abstract

Topological systems are inherently robust to disorder and continuous perturbations, resulting in dissipation-free edge transport of electrons in quantum solids, or reflectionless guiding of photons and phonons in classical wave systems characterized by topological invariants. Despite considerable efforts, direct experimental demonstration of theoretically predicted robust, lossless energy transport in topological insulators operating at terahertz frequencies is needed further investigations to shed affirmative light on the unique properties enabled by topological protection. Here, we introduce Kagome lattice that exhibits a new class of symmetry-protected topological phases with very low Berry curvature but nontrivial bulk polarization, and fabricate an optical topological insulator that provide the valley hall effect. Theoretical analysis show that four type edge states can be obtained. Measurements of THz-TDs with high time-resolution demonstrate that terahertz wave propagating along the straight topological edge and Z-shape edge with sharp turns have almost same high transmission in 0.440 THz to 0.457 THz domain range. Those results quantitatively illustrate the suppression of backscattering due to the non-trivial topology of the structure. The THz-TDs measurement yields amplitude and phase information, showing significant advantage compared to general broadband infrared, single wavelength continuous-wave THz measurements and visible spectroscopy. It allows further exploration of the effective refractive index, group velocity and dispersion relations of edge states. Our work offers possibilities for advanced control of the propagation and manipulation of THz waves, and facilitates the applications including sixth-generation (6G) wireless communication, terahertz integrated circuits, and interconnects for intrachip and interchip communication.

Published
2022

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