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Genomics-driven derivatization of the bioactive fungal sesterterpenoid variecolin:Creation of an unnatural analogue with improved anticancer properties

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Acta Pharmaceutica Sinica B 2024年第1期14卷 421-432页

作者： Dexiu Yan Jemma Arakelyan Teng Wan Ritvik Raina Tsz Ki Chan Dohyun Ahn Vladimir Kushnarev Tsz Kiu Cheung Ho Ching Chan Inseo Choi Pui Yi Ho Feijun Hu Yujeong Kim Hill Lam Lau Ying Lo Law Chi Seng Leung Chun Yin Tong Kai Kap Wong Wing Lam Yim Nikolay S.Karnaukhov Richard Y.C.kong Maria V.Babak Yudai Matsuda Department of Chemistry City University of Hong KongHong Kong SARChina iGEM Team“VarieCure” City University of Hong KongHong Kong SARChina Department of Biomedical Engineering City University of Hong KongHong Kong SARChina Moscow Clinical Research Center Named After A.S.Loginov Moscow 111123Russian Federation

A biosynthetic gene cluster for the bioactive fungal sesterterpenoids variecolin(1)and variecolactone(2)was identified in Aspergillus aculeatus ATCC 16872.Heterologous production of 1 and 2 was achieved in Aspergillus oryzae by expressing the sesterterpene synthase VrcA and the cytochrome P450 VrcB.Intriguingly,the replacement of VrcB with homologous P450s from other fungal terpenoid pathways yielded three new variecolin analogues(5-7).Analysis of the compounds’anticancer activity in vitro and in vivo revealed that although 5 and 1 had comparable activities,5 was associated with significantly reduced toxic side effects in cancer-bearing mice,indicating its potentially broader therapeutic window.Our study describes the first tests of variecolin and its analogues in animals and demonstrates the utility of synthetic biology for creating molecules with improved biological activities.

关键词： Animal studies Anticancer properties Biosynthesis Natural products Sesterterpenoids Synthetic biology Terpene synthases Variecolin

The blueprint for service transformation at the city university of hong kong Library:The project for RFID applications as the starting point

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Journal of Library Science in China 2009年 22-36页

作者： Hsianghoo Steve CHING Alice TAI Mengxin CAI Michael CHENG Run Run Shaw Library City University of Hong Kong

With the rapid development of information and communication technologies,it is now time for libraries to re-position their service norms.From a traditional service mode that is manual-based,libraries should now become functionally more versatile through the provision of multifaceted services via different channels and modes such as self-services,digital libraries,and value-added services.The Run Run Shaw Library at the city university of hong kong,through strategic space planning between campuses,e-resources collection development,space re-organization,staff deployment,and innovative new services,has formulated a blueprint for its service transformation.Radio Frequency Identification(RFID) technology,offering opportunities for the Library to improve its service quality,has become a core element of the blueprint.Two pilot projects focusing on the application of Ultra High Frequency RFID and High Frequency RFID technologies respectively in the library environment have been initiated.To achieve the best results,the Library has taken into consideration different factors,such as time,space,budget,manpower,and organizational structure.Careful coordination of these different factors has generated the greatest synergy.

关键词： The blueprint service transformation hong kong Library

Quantization and Event-Triggered Policy Design for Encrypted Networked Control

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 946-955页

作者： Yongxia Shi Ehsan Nekouei the Department of Electrical Engineering City University of Hong KongHong KongChina

This paper proposes a novel event-driven encrypted control framework for linear networked control systems(NCSs),which relies on two modified uniform quantization policies,the Paillier cryptosystem,and an event-triggered strategy.Due to the fact that only integers can work in the Pailler cryptosystem,both the real-valued control gain and system state need to be first quantized before encryption.This is dramatically different from the existing quantized control methods,where only the quantization of a single value,e.g.,the control input or the system state,is considered.To handle this issue,static and dynamic quantization policies are presented,which achieve the desired integer conversions and guarantee asymptotic convergence of the quantized system state to the equilibrium.Then,the quantized system state is encrypted and sent to the controller when the triggering condition,specified by a state-based event-triggered strategy,is satisfied.By doing so,not only the security and confidentiality of data transmitted over the communication network are protected,but also the ciphertext expansion phenomenon can be relieved.Additionally,by tactfully designing the quantization sensitivities and triggering error,the proposed event-driven encrypted control framework ensures the asymptotic stability of the overall closedloop system.Finally,a simulation example of the secure motion control for an inverted pendulum cart system is presented to evaluate the effectiveness of the theoretical results.

关键词： Cyber-security encrypted control event-triggered control(ETC) networked control systems(NCSs) semi-homomorphic encryption

Nanoimprint-induced strain engineering of two-dimensional materials

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Microsystems & Nanoengineering 2024年第2期10卷 323-332页

作者： Chuying Sun Jianwen Zhong Zhuofei Gan Liyang Chen Chuwei Liang hongtao Feng Zhao Sun Zijie Jiang Wen-Di Li The university of hong kong Hong KongChina

The high stretchability of two-dimensional(2D)materials has facilitated the possibility of using external strain to manipulate their properties.Hence,strain engineering has emerged as a promising technique for tailoring the performance of 2D materials by controlling the applied elastic strain field.Although various types of strain engineering methods have been proposed,deterministic and controllable generation of the strain in 2D materials remains a challenging task.Here,we report a nanoimprint-induced strain engineering(NISE)strategy for introducing controllable periodic strain profiles on 2D materials.A three-dimensional(3D)tunable strain is generated in a molybdenum disulfide(MoS_(2))sheet by pressing and conforming to the topography of an imprint mold.Different strain profiles generated in MoS_(2)are demonstrated and verified by Raman and photoluminescence(PL)spectroscopy.The strain modulation capability of NISE is investigated by changing the imprint pressure and the patterns of the imprint molds,which enables precise control of the strain magnitudes and distributions in MoS_(2).Furthermore,a finite element model is developed to simulate the NISE process and reveal the straining behavior of MoS_(2).This deterministic and effective strain engineering technique can be easily extended to other materials and is also compatible with common semiconductor fabrication processes;therefore,it provides prospects for advances in broad nanoelectronic and optoelectronic devices.

关键词： strain dimensional molybdenum

Metal/covalent organic frameworks for aqueous rechargeable zinc-ion batteries

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Science China Chemistry 2024年第1期67卷 247-259页

作者： Hu hong Xun Guo Jiaxiong Zhu Zhuoxi Wu Qing Li Chunyi Zhi Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China

Lithium-ion batteries(LIBs)have become one of the most successful energy storage systems due to their high operating voltage,high energy density,and long cycle life.However,with the widespread use of LIBs in recent decades,lithium resources are at risk of being exhausted.Therefore,it is necessary to find a substitute for LIBs to meet the needs of future large-scale energy storage systems.Because of their competitiveness,low cost,and high safety,aqueous rechargeable zinc-ion batteries(ARZIBs)are regarded as promising components in the post-lithium-ion-battery era.Given the tunable composition,ordered porous channels,and controllable structure of metal-organic frameworks(MOFs)and covalent organic frameworks(COFs),these frameworks are viewed as potential materials for developing high-performance ARZIBs.In this review,we focus on the recent developments in the applications of MOF-/COF-based materials in ARZIBs,including in electrode materials,anode modifications,separators,and solid electrolytes.We then focus on the critical factors and optimization techniques of MOF-/COF-based materials that affect the performance of ARZIBs.Finally,we conclude with some projections for the expansion of ARZIBs containing MOF-/COF-based materials.

关键词： metal/covalent organic frameworks aqueous zinc-ion batteries electrode materials anode modifications separators electrolytes

Does astrocytic L-lactate enhance cognition through myelination?

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Neural Regeneration Research 2024年第6期19卷 1167-1168页

作者： Mastura Akter Ying Li Department of Neuroscience City University of Hong Kong Department of Biomedical Sciences City Universit of Hong Kong Centre for Regenerative Medicine and Health Hong Kong Institute of Science & Innovation Chinese Academy of Sciences Centre for Biosystems Neuroscience and Nanotechnology City University of Hong Kong

Introduction: Astrocytes, the predominant glial cell in the brain, play a vital role in a plethora of central ner vous system functions. They are the major storage site of glycogen in the central nervous system. They produce L-lactate by glycogenolysis and glycolysis which is then transported to neurons(Magistreti and Allaman,

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Hierarchical crystalline-amorphous nanocomposites with high strength and large deformability enabled by elemental diffusion

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Journal of Materials Science & Technology 2024年第4期171卷 150-161页

作者： Liqiang Wang Heyi Wang Xin Zhou Huangliu Fu James Utama Surjadi Shuo Qu Xu Song Rong Fan Yang Lu Department of Mechanical Engineering City University of Hong KongHong KongChina Nano-Manufacturing Laboratory(NML) Shenzhen Research Institute of City University of Hong KongShenzhen 518057China Chengdu Research Institute City University of Hong KongChengdu 610200China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina Department of Mechanical Engineering The University of Hong KongHong KongChina

Amorphous/nanocrystalline dual-phase structures have recently emerged as an effective way for over-coming the strength-ductility trade-offand breaking the limitation of the reverse Hall-Petch effect.Here,we proposed a new strategy to develop a hierarchical and interconnected amorphous-crystalline nanocomposite arising from the nanoscale elemental interdiffusion and oxygen adsorption behavior dur-ing thermal treatment processes.The nanocomposite consisted of a three-dimensional(3D)hierarchical network structure where the crystalline phase(Cr-Co-Ni-Al)was embedded into the Al-O-based amor-phous phase network with critical feature sizes encompassing three orders of magnitude(from microm-eter to nanometer scale).It can achieve ultrahigh compression yield strength of-3.6 GPa with large homogeneous deformation of over 50%strain.The massive interstitial atoms induced lattice distortion and hierarchical amorphous phase boundary contributed to the strength improvement.in situ Uniaxial compression inside a transmission electron microscope(TEM)revealed that the exceptional deformability of the nanocomposites resulted from the homogenous plastic flow of nano-sized amorphous phase and the plastic co-deformation behavior restricted by the nano-architected dual-phase interface.The proposed dual-phase synthesis approach can outperform conventional nanolaminates design strategies in terms of the mechanical properties achievable while providing a pathway to easily tune the microstructure of these nanolaminates.

关键词： Nanolaminates Dual-phase nanocomposites In situ transmission electron microscopy Multi-component alloy

Characterization of a smog chamber for studying formation of gas-phase products and secondary organic aerosol

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Journal of Environmental Sciences 2024年第2期136卷 570-582页

作者： Qi Yuan Zhuozhi Zhang Meng Wang Kin Fai Ho Tao Wang Shuncheng Lee Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina School of Public Health and Primary Care The Chinese University of Hong KongShatinHong KongChina

Smog chambers provide a potent approach to explore the secondary organic aerosol formation under varied conditions.This study describes the construction and characterization of a new smog chamber facility for studying the formation mechanisms of gas-phase products and secondary organic aerosol from the photooxidation of volatile organic compounds.The chamber is a 5.4 m^(3) Fluorinated Ethylene Propylene(FEP)Teflon reactor with the potential to perform photooxidation experiments at controlled temperature and relative humidity.Detailed characterizations were conducted for evaluation of stability of environmental parameters,mixing time,background contamination,light intensity,and wall losses of gases and particles.The photolysis rate of NO_(2)(J_(NO2))ranged from(1.02-3.32)×10^(-3)sec^(-1),comparable to the average J_(NO2)in ambient environment.The wall loss rates for NO,NO_(2),and O_(3)were 0.47×10^(-4),0.37×10^(-4),and 1.17×10^(-4)min^(-1),while wall loss of toluene was obsoletely found in a 6 hr test.The particle number wall loss rates are(0.01-2.46)×10^(-3)min^(-1)for 40-350 nm with an average lifetime of more than one day.A series of toluene photooxidation experiments were carried out in absence of NO_xunder dry conditions.The results of the simulation experiments demonstrated that the chamber is well designed to simulate photolysis progress in the atmosphere.

关键词： Smog chamber Gas-phase oxidation Chamber characterization Chemical mechanism

Quantitative and qualitative subgenomic RNA profiles of SARS-CoV-2 in respiratory samples: A comparison between Omicron BA.2 and non-VOC-D614G

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Virologica Sinica 2024年第2期39卷 218-227页

作者： Zigui Chen Rita Way Yin Ng Grace Lui Lowell Ling Agnes S.Y.Leung Chit Chow Siaw Shi Boon Wendy C.S.Ho Maggie Haitian Wang Renee Wan Yi Chan Albert Martin Li David Shu Cheong Hui Paul Kay Sheung Chan Department of Microbiology Faculty of MedicineThe Chinese University of Hong KongHong KongChina Department of Medicine and Therapeutics Faculty of MedicineThe Chinese University of Hong KongHong KongChina Department of Anaesthesia and Intensive Care Faculty of MedicineThe Chinese University of Hong KongHong KongChina Department of Paediatrics Faculty of MedicineThe Chinese University of Hong KongHong KongChina Department of Anatomical and Cellular Pathology Faculty of MedicineThe Chinese University of Hong KongHong KongChina Jockey Club School of Public Health and Primary Care Faculty of MedicineThe Chinese University of Hong KongHong KongChina Stanley Ho Centre for Emerging Infectious Diseases Faculty of MedicineThe Chinese University of Hong KongHong KongChina

The SARS-CoV-2 Omicron variants are notorious for their transmissibility,but little is known about their subgenomic RNA(sgRNA)expression.This study applied RNA-seq to delineate the quantitative and qualitative profiles of canonical sgRNA of 118 respiratory samples collected from patients infected with Omicron BA.2 and compared with 338 patients infected with non-variant of concern(non-VOC)-D614G.A unique characteristic profile depicted by the relative abundance of 9 canonical sgRNAs was reproduced by both BA.2 and non-VOCD614G regardless of host gender,age and presence of pneumonia.Remarkably,such profile was lost in samples with low viral load,suggesting a potential application of sgRNA pattern to indicate viral activity of individual patient at a specific time point.A characteristic qualitative profile of canonical sgRNAs was also reproduced by both BA.2 and non-VOC-D614G.The presence of a full set of canonical sgRNAs carried a coherent correlation with crude viral load(AUC¼0.91,95%CI 0.88–0.94),and sgRNA ORF7b was identified to be the best surrogate marker allowing feasible routine application in characterizing the infection status of individual patient.Further potentials in using sgRNA as a target for vaccine and antiviral development are worth pursuing.

关键词： Coronavirus SARS-CoV-2 Omicron BA.2 Non-VOC-D614G RNA-seq Subgenomic RNA(sgRNA)