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3,887 results on '"Lam, Jacky"'

1. Artificially built Kondo chains with organic radicals on metallic surfaces: new model system of heavy fermion quantum criticality

Author

Li, En, Danu, Bimla, Liu, Yufeng, Xie, Huilin, Lam, Jacky Wing Yip, Tang, Ben Zhong, Wang, Shiyong, Assaad, Fakher F., and Lin, Nian

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
Abstract

Heavy fermion quantum criticality is an extremely rich domain of research which represents a framework to understand strange metals as a consequence of a Kondo breakdown transition. Here we provide an experimental realization of such systems in terms of organic radicals on a metallic surface. The ground state of organic radicals is a Kramer's doublet that can be modeled by a spin 1/2 degree of freedom. Using on-surface synthesis and scanning tunneling microscopy (STM) tip manipulation, one can controllably engineer and characterize chains of organic radicals on a Au(111) surface. The spatial-resolved differential conductance reveals site-dependent low-energy excitations, which support the picture of emergent many-body Kondo physics. Using quantum Monte Carlo simulations, we show that a Kondo lattice model of spin chains on a metallic surface reproduces accurately the experimental results. This allows us to interpret the experimental results in terms of a heavy fermion metal, below the coherence temperature. We foresee that the tunability of these systems will pave the way to realize quantum simulators of heavy fermion criticality.

Published
2024

5. Aggregation-Induced Emission (AIE), Life and Health.

Author

Wang, Haoran, Li, Qiyao, Alam, Parvej, Bai, Haotian, Bhalla, Vandana, Bryce, Martin, Cao, Mingyue, Chen, Chao, Chen, Sijie, Chen, Xirui, Chen, Yuncong, Chen, Zhijun, Dang, Dongfeng, Ding, Dan, Ding, Siyang, Duo, Yanhong, Gao, Meng, He, Wei, He, Xuewen, Hong, Xuechuan, Hong, Yuning, Hu, Jing-Jing, Hu, Rong, Huang, Xiaolin, James, Tony, Jiang, Xingyu, Konishi, Gen-Ichi, Kwok, Ryan, Lam, Jacky, Li, Chunbin, Li, Haidong, Li, Kai, Li, Nan, Li, Wei-Jian, Li, Ying, Liang, Xing-Jie, Liang, Yongye, Liu, Guozhen, Liu, Xingang, Lou, Xiaoding, Lou, Xin-Yue, Luo, Liang, McGonigal, Paul, Mao, Zong-Wan, Niu, Guangle, Owyong, Tze, Pucci, Andrea, Qian, Jun, Qin, Anjun, Qiu, Zijie, Rogach, Andrey, Situ, Bo, Tanaka, Kazuo, Tang, Youhong, Wang, Bingnan, Wang, Dong, Wang, Jianguo, Wang, Wei, Wang, Wen-Xiong, Wang, Wen-Jin, Wang, Xinyuan, Wang, Yi-Feng, Wu, Shuizhu, Wu, Yifan, Xiong, Yonghua, Xu, Ruohan, Yan, Chenxu, Yan, Saisai, Yang, Hai-Bo, Yang, Lin-Lin, Yang, Mingwang, Yang, Ying-Wei, Yoon, Juyoung, Zang, Shuang-Quan, Zhang, Jiangjiang, Zhang, Pengfei, Zhang, Tianfu, Zhang, Xin, Zhao, Na, Zhao, Zheng, Zheng, Jie, Zheng, Lei, Zheng, Zheng, Zhu, Ming-Qiang, Zhu, Wei-Hong, Zou, Hang, Tang, Ben, and Liu, Bin

Subjects
aggregation-induced emission, bioimaging, biomedical application, combined therapy, detection, luminescent material, monitoring, phototheranostics, precision medicine, Fluorescent Dyes, Luminescent Agents, Luminescence, Diagnostic Imaging, Delivery of Health Care
Abstract

Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health.

Published
2023

28. BOIMPY Scaffold: Accessing Ultrahigh Molar Extinction Coefficient AIEgen for SWIR Imaging‐Guided Photothermal Cancer Ablation.

Author

Yang, Mingwang, Ou, Xinwen, Zhang, Jianyu, Sun, Jianwei, Kwok, Ryan T. K., Lam, Jacky W. Y., Fan, Jiangli, and Tang, Ben Zhong

Subjects
BRIDGING ligands, FLUORESCENCE, ABSORPTION, CEILINGS, PHOTOTHERMAL effect, INFRARED absorption
Abstract

Despite the extensive reporting of versatile aggregation‐induced emission luminogens (AIEgens), boosting their molar extinction coefficient (MEC, ε ≈ 103–104 M−1cm−1) remains a formidable challenge, which poses a significant obstacle to achieving the ceiling of their output performance. In this work, an "aggrandizing absorption reservoir" approach is proposed to designing AIEgens with remarkable photons‐harvesting ability, ultimately enlarging its output performance in terms of short‐wave infrared (SWIR, 900–1700 nm) emission and photothermal effect. For the first time, the (bis‐(borondifluoride)‐8‐imidazodipyrromethene) (BOIMPY) unit, which provides sufficient rigidity and strong electron‐withdrawing ability by employing benzimidazole as a bridging ligand binding two BF2 units, is utilized to fabricate novel AIEgen (TPEB) that exhibits an ultrahigh MEC up to 1.29 × 105 M−1 cm−1 at 828 nm. To the best of knowledge, this is the highest MEC reported among AIEgens with near‐infrared absorption. Thanks to its remarkable photon‐harvesting ability, TPEB exhibits strong fluorescence in the SWIR region and a good photothermal effect. The as‐prepared TPEB NPs are successfully applied for SWIR imaging‐guided photothermal antitumor therapy. The proposed "aggrandizing absorption reservoir" approach provides a novel guideline for designing versatile AIEgens for biomedical applications. [ABSTRACT FROM AUTHOR]

Published
2025
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29. Two‐Photon Clusteroluminescence Enabled by Through‐Space Conjugation for In Vivo Bioimaging.

Author

Zhang, Jianyu, Shen, Hanchen, Xiong, Zuping, Du, Lidong, Li, Moxin, Ou, Xinwen, Zhu, Xinyan, Lam, Jacky W. Y., Liu, Tzu‐Ming, Xu, Changhuo, Zhang, Haoke, and Zhong Tang, Ben

Subjects
ELECTRON delocalization, OPTICAL properties, BLOOD vessels, LUMINESCENCE, BIOCOMPATIBILITY
Abstract

Clusteroluminescence (CL) materials without largely conjugated structures have gained significant attention due to their unique photophysical properties and potential in bioimaging. However, low luminescence efficiency and short emission wavelength limit their development. This work designs three luminogens with CL properties (CLgens) by introducing n‐electron‐involved through‐space conjugation (TSC) into diarylmethane. Apart from single‐photon excited long‐wavelength (686 nm) and high‐efficiency (29 %) CL, two‐photon clusteroluminescence (TPCL) is successfully achieved in such small luminogens with only two isolated heteroatomic units. TSC stabilized in the aggregate state has been proven to realize efficient spatial electron delocalization similar to conventionally conjugated compounds. Encouraged by the excellent TPCL properties, two‐photon imaging of blood vessels in vivo and biocompatibility verification utilizing CLgens are also achieved. This work illustrates the essential role of TSC in promoting nonlinear optical properties of CLgens and may facilitate further design and development of the next generation of bioprobes with excellent biocompatibility. [ABSTRACT FROM AUTHOR]

Published
2025
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30. Development of Controllable Hetero‐Pauson‐Khand Polymerization to Functional Stimuli‐Responsive Poly(γ‐lactam)s.

Author

Du, Wutong, Liu, Xinyue, Sun, Feiyi, Lam, Jacky W. Y., Yang, Jinglei, and Tang, Ben Zhong

Subjects
REACTIVE oxygen species, BIOLOGICAL systems, POLYMER structure, MOLECULAR weights, BIOMIMETICS
Abstract

Polymers containing lactam structures play a crucial role in both natural biological systems and human life, and their synthesis, functions and applications are of utmost importance for biomimetics and the creation of new materials. In this study, we developed an efficient heterogeneous Pauson–Khand polymerization (h‐PKP) method for the controlled synthesis of main‐chain poly(γ‐lactam)s containing α, β‐unsaturated γ‐lactam functionalities using readily available internal alkynes and imines. The molecular weights of the resulting poly(N−Ts/γ‐lactam)s can be precisely controlled by adjusting the ratio of phenyl formate and nickel. These polymers exhibit high solid‐state luminescence and demonstrate rapid and sensitive dual responsiveness to light and acid stimuli. They further demonstrate strong reactive oxygen species (ROS) generation capability. The unique dual‐emission peaks observed in poly(N−H/γ‐lactam)s obtained through post‐treatment under acidic conditions demonstrate a mechanism of aggregation‐induced intermolecular excited‐state proton transfer specific to lactam structures. The efficient one‐pot synthetic method for poly(γ‐lactam) provides a novel strategy for constructing polymers with γ‐lactam structures in the main chain and the simple and efficient post‐modification method offer a versatile toolbox for functionalizing poly(γ‐lactam)s to expand their potential applications. [ABSTRACT FROM AUTHOR]

Published
2025
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32. Two‐Photon‐Activated Heavy‐Atom Free AIEgen for Highly Efficient Type I Photodynamic Therapy.

Author

Liu, Ji, Ou, Xinwen, Wang, Kaizhen, Wang, Ke, Gui, Lijuan, Song, Fengyan, Chen, Chao, Lam, Jacky W. Y., Yuan, Zhenwei, and Tang, Ben Zhong

Subjects
PHOTODYNAMIC therapy, CANCER cell growth, TREATMENT effectiveness, REACTIVE oxygen species, PHOTOSENSITIZERS
Abstract

The therapeutic efficacy of photosensitizers in photodynamic therapy (PDT) largely depends on the reactive oxygen species production, types, and tissue penetration depth. Particularly in malignant tumors, hypoxia is widely recognized as a major obstacle for PDT. Herein, a two‐photon‐excitable heavy‐atom free photosensitizer PNF is designed. PNF can be used as a type‑I photosensitizer to overcome the limitations of PDT in treating hypoxic tumors. The photosensitizer PNF exhibits distinct aggregation‐induced emission characteristics and can generate O2•− and OH• through type I photochemical processes upon 808 nm laser irradiation. The two‐photon‐activated PDT induced by PNF disrupts cellular redox homeostasis, and increases levels of lipid peroxidation, leading to apoptosis, as well as ferroptosis. In vitro and in vivo experiments demonstrate the effectiveness of this synergistic treatment strategy in inhibiting the growth of hypoxic cancer cells and tumors. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Visualizing Triplet Energy Transfer in Organic Near‐Infrared Phosphorescent Host‐Guest Materials.

Author

Deng, Zihao, Kong, Fan‐Cheng, Deng, Ziqi, Zhou, Jiaming, Yang, Shengyi, He, Shan, Zhang, Jianyu, Zuo, Yunfei, Wang, Jin, Chen, Xinmeng, Kwok, Ryan T. K., Jia, Guocheng, Chow, Philip C. Y., Phillips, David Lee, Alam, Parvej, Lam, Jacky W. Y., and Zhong Tang, Ben

Subjects
HYBRID materials, BAND gaps, ENERGY transfer, LIBRARY design & construction, EXCITON theory, PHOSPHORESCENCE, PHOSPHORESCENCE spectroscopy
Abstract

Limited by the energy gap law, purely organic materials with efficient near‐infrared room temperature phosphorescence are rare and difficult to achieve. Additionally, the exciton transition process among different emitting species in host–guest phosphorescent materials remains elusive, presenting a significant academic challenge. Herein, using a modular nonbonding orbital‐π bridge‐nonbonding orbital (n‐π‐n) molecular design strategy, we develop a series of heavy atom‐free phosphors. Systematic modification of the π‐conjugated cores enables the construction of a library with tunable near‐infrared phosphorescence from 655 to 710 nm. These phosphors exhibit excellent performance under ambient conditions when dispersed into a 4‐bromobenzophenone host matrix, achieving an extended lifetime of 11.25 ms and a maximum phosphorescence efficiency of 4.2 %. Notably, by eliminating the interference from host phosphorescence, the exciton transition process in hybrid materials can be visualized under various excitation conditions. Spectroscopic analysis reveals that the improved phosphorescent performance of the guest originates from the triplet‐triplet energy transfer of abundant triplet excitons generated independently by the host, rather than from enhanced intersystem crossing efficiency between the guest singlet state and the host triplet state. The findings provide in‐depth insights into constructing novel near‐infrared phosphors and exploring emission mechanisms of host–guest materials. [ABSTRACT FROM AUTHOR]

Published
2024
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44. Chiral Nanostructures from Artificial Helical Polymers: Recent Advances in Synthesis, Regulation, and Functions

Author

Qiu, Yuan, Wei, Xilong, Lam, Jacky W. Y., Qiu, Zijie, and Tang, Ben Zhong

Abstract

Helical structures such as right-handed double helix for DNA and left-handed α-helix for proteins in biological systems are inherently chiral. Importantly, chirality at the nanoscopic level plays a vital role in their macroscopic chiral functionalities. In order to mimic the structures and functions of natural chiral nanoarchitectures, a variety of chiral nanostructures obtained from artificial helical polymers are prepared, which can be directly observed by atomic force microscopy (AFM), scanning tunneling microscopy (STM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). This review mainly focuses on the formation of chiral nanostructures and the morphology regulation triggered by polymer chain length, concentration, solvent, temperature, photoirradiation, and chemical additives. In addition, the distinct chiral functions including chiral recognition, circularly polarized luminescence, drug release, cell imaging, and antibiosis are also discussed.

Published
2025
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45. Intramolecular Repulsive Interactions Enable High Efficiency of NIR-II Aggregation-Induced Emission Luminogens for High-Contrast Glioblastoma Imaging

Author

Ma, Fulong, Gao, Zhiyuan, Jia, Qian, Yang, Ying, Wang, Bingzhe, Zhang, Jianyu, Deng, Ziwei, Mo, Rufan, Ding, Zeyang, Xing, Guichuan, Liu, Yong, Wang, Zhongliang, Wang, Kaikai, Lam, Jacky W. Y., Ding, Dan, Zhao, Zheng, and Tang, Ben Zhong

Abstract

Strategies to acquire high-efficiency luminogens that emit in the second near-infrared (NIR-II, 1000–1700 nm) range are still rare due to the impediment of the energy gap law. Herein, a feasible strategy is pioneered by installing large-volume encumbrances in a confined space to intensify the repulsive interactions arising from overlapping electron densities. The experimental results, including smaller coordinate displacement, reduced reorganization energy, and suppressed internal conversion, demonstrate that the repulsive interactions assist in the inhibition of radiationless deactivation. Meanwhile, the configuration and hybridization form of the donor units are transformed along with the repulsive interactions, bringing about improved oscillator strength. A 3.8-fold higher luminescence efficiency is realized via the synergistic effect. Furthermore, the repulsive interactions endow the NIR-II fluorophores with a highly twisted conformation, superior AIE activity, and cascaded improvement of fluorescence emission from isolated molecules to aggregates. By utilizing a brain-targeting peptide to functionalize the NIR-II nanoparticles, accurate detection and high-contrast imaging of orthotopic glioblastoma are realized. This work not only explores a fundamental principle to handle the intractable energy gap law but also provides potential applications of NIR-II luminogens in high-contrast bioimaging and glioblastoma detection.

Published
2025
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46. Recent Progress in Nanomedicine for the Diagnosis and Treatment of Alzheimer’s Diseases

Author

Yang, Han, Tan, Haozhe, Wen, Haifei, Xin, Peikun, Liu, Yanling, Deng, Ziwei, Xu, Yanning, Gao, Feng, Zhang, Liping, Ye, Ziyue, Zhang, Zicong, Chen, Yunhao, Wang, Yueze, Sun, Jianwei, Lam, Jacky W. Y., Zhao, Zheng, Kwok, Ryan T. K., Qiu, Zijie, and Tang, Ben Zhong

Abstract

Alzheimer’s disease (AD) is a neurodegenerative disease that causes memory loss and progressive and permanent deterioration of cognitive function. The most challenging issue in combating AD is its complicated pathogenesis, which includes the deposition of amyloid β (Aβ) plaques, intracellular hyperphosphorylated tau protein, neurofibrillary tangles (NFT), etc. Despite rapid advancements in mechanistic research and drug development for AD, the currently developed drugs only improve cognitive ability and temporarily relieve symptoms but cannot prevent the development of AD. Moreover, the blood–brain barrier (BBB) creates a huge barrier to drug delivery in the brain. Therefore, effective diagnostic tools and treatments are urgently needed. In recent years, nanomedicine has provided opportunities to overcome the challenges and limitations associated with traditional diagnostics or treatments. Various types of nanoparticles (NPs) play an essential role in nanomedicine for the diagnosis and treatment of AD, acting as drug carriers to improve targeting and bioavailability across/bypass the BBB or acting as drugs directly on AD lesions. This review categorizes different types of NPs and summarizes their applications in nanomedicine for the diagnosis and treatment of AD. It also discusses the challenges associated with clinical applications and explores the latest developments and prospects of nanomedicine for AD.

Published
2024
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