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Acoustofluidic localization of sparse particles on a piezoelectric resonant sensor for nanogram-scale mass measurements

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Microsystems & Nanoengineering 2021年第4期7卷 117-125页

作者： Jingui Qian Habiba Begum Joshua E.-Y.Lee Department of Electrical Engineering City University of Hong KongKowloonHong Kong SARChina State Key laboratory of Terahertz and Millimeter Waves City University of Hong KongKowloonHong Kong SARChina

The ability to weigh microsubstances present in low concentrations is an important tool for environmental monitoring and chemical *** instance,developing a rapid analysis platform that identifies the material type of microplastics in seawater would help evaluate the potential toxicity to marine *** this study,we demonstrate the integration of two different techniques that bring together the functions of sparse particle localization and miniaturized mass sensing on a microelectromechanical system(MEMS)chip for enhanced detection and minimization of negative *** droplet sample for analysis is loaded onto the MEMS chip containing a resonant mass *** the coupling of a surface acoustic wave(SAW)from a SAW transducer into the chip,the initially dispersed microparticles in the droplet are localized over the detection area of the MEMS sensor,which is only 200 pm *** accreted mass of the particles is then calibrated against the resulting shift in resonant frequency of the *** SAW device and MEMS chip are detachable after use,allowing the reuse of the SAW device part of the setup instead of the disposal of both *** platform maintains the strengths of noncontact and label-free dual-chip acoustofluidic devices,demonstrating for the first time an integrated microparticle manipulation and real-time mass measurement platform useful for the analysis of sparse microsubstances.

关键词： resonant sparse mass

Has LIGO detected primordial black hole dark matter?——tidal disruption in binary black hole formation

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Research in Astronomy and Astrophysics 2020年第11期20卷 303-311页

作者： Yuan Gao Xiao-Jia Zhang Meng Su Department of Physics The University of Hong KongHong Kong SARChina Department of Earth Sciences The University of Hong KongHong Kong SARChina Department of Physics and laboratory for Space Research The University of Hong KongHong Kong SARChina

The frequent detection of binary mergers of^30 M⊙black holes(BHs)by the Laser Interferometer Gravitational-Wave Observatory(LIGO)rekindled researchers’interest in primordial BHs(PBHs)being dark matter(DM).In this work,we investigated PBHs distributed as DM with a monochromatic mass of 30 M⊙and examined the encounter-capture scenario of binary formation,where the densest central region of DM halo ***,we paid special attention to the tidal effect by the supermassive black hole(SMBH)*** doing so,we discovered a necessary tool called loss zone that complements the usage of loss *** found that the tidal effect is not prominent in affecting binary formation,which also turned out to be insufficient in explaining the totality of LIGO’s event rate estimation,especially due to a microlensing event constraining the DM fraction in PBH at the mass of interest from near unity to an order ***,an early-universe binary formation scenario proves so prevailing that the LIGO signal in turn constrains the PBH fraction below one ***,people should put more faith in alternative PBH windows and other DM candidates.

关键词： black hole physics dark matter gravitational waves quasars supermassive black holes

On-demand light-driven release of droplets stabilized via a photoresponsive fluorosurfactant

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Microsystems & Nanoengineering 2023年第4期9卷 223-231页

作者： Guangyao Cheng Qinru Xiao Chit Yau Kuan Yi-Ping Ho Department of Biomedical Engineering The Chinese University of Hong KongHong Kong SARChina Centre for Novel Biomaterials The Chinese University of Hong KongHong Kong SARChina hong kong Branch of CAS Center for Excellence in Animal Evolution and Genetics The Chinese University of Hong KongHong Kong SAR 999077China The Ministry of Education Key laboratory of Regeneration Medicine The Chinese University of Hong KongHong Kong SARChina

Water-in-oil droplets have emerged as promising microreactors for high-throughput biochemical analysis due to their features of reduced sample consumption and automated *** a typical screening application,droplets are often trapped for continuous monitoring of the reaction over an extended period,followed by the selective retrieval of targeted droplets based on the after-effect of biochemical *** techniques for droplet trapping are well developed,retrieval of targeted droplets mainly demands complicated device fabrication or sophisticated ***,facile and rapid selective droplet release is achieved by utilizing a new class of photoresponsive fluorosurfactant based on plasmonic *** intense photothermal response provided by this novel photoresponsive fluorosurfactant is capable of vaporizing the fluorocarbon oil at the droplet interface under laser illumination,resulting in a bubble releasing a trapped droplet on demand.A fully automated fluorescence-activated droplet release platform has also been developed to demonstrate its potential for droplet-based large-scale screening applications.

关键词： surfactant release stabilized

Salt Tolerance in Soybean

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Journal of Integrative Plant Biology 2008年第10期50卷 1196-1212页

作者： Tsui-Hung Phang Hon-Ming Lam Department of Biology The Chinese University of Hong KongShatinHong Kong China State Key laboratory for Agrobiotechnology The Chinese University of Hong KongShatinHong Kong China

Soybean is an important cash crop and its productivity is significantly hampered by salt stress. High salt imposes negative impacts on growth, nodulation, agronomy traits, seed quality and quantity, and thus reduces the yield of soybean. To cope with salt stress, soybean has developed several tolerance mechanisms, including：（i） maintenance of ion homeostasis; （ii） adjustment in response to osmotic stress; （iii） restoration of osmotic balance; and （iv） other metabolic and structural adaptations. The regulatory network for abiotic stress responses in higher plants has been studied extensively in model plants such as Arabidopsis thaliana. Some homologous components involved in salt stress responses have been identified in soybean. In this review, we tried to integrate the relevant works on soybean and proposes a working model to describe its salt stress responses at the molecular level.

关键词： abiotic stress Glycine max ion homeostasis osmotic adjustment reactive oxygen species scavenging salt tolerance soybean.

Leptotrichia hongkongensis ***.,a novel Leptotrichia species with the oral cavity as its natural reservoir

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2010年第6期11卷 391-401页

作者： Patrick C. Y. WOO Samson S. Y. WONG Jade L. L. TENG Kit-Wah LEUNG Antonio H. Y. NGAN Dong-qing ZHAO Herman TSE Susanna K. P. LAU Kwok-Yung YUEN State Key laboratory of Emerging Infectious Diseases The University of Hong Kong Hong Kong China Research Centre of Infection and Immunology The University of Hong Kong Hong Kong China Department of Microbiology The University of Hong Kong Hong Kong China Carol Yu Centre for Infection The University of Hong Kong Hong Kong China

A straight, non-sporulating, Gram-variable bacillus (HKU24T) was recovered from the blood culture of a patient with metastatic breast carcinoma. After repeated subculturing in BACTEC Plus Anaerobic/F blood culture broth, HKU24T grew on brucella agar as non-hemolytic, pinpoint colonies after 96 h of incubation at 37 °C in an anaerobic environment and aerobic environment with 5% CO2. Growth was enhanced with a streak of Staphylococcus aureus. HKU24T was non-motile and catalase-negative, but positive for alkaline phosphatase, β-glucosidase, and α-glucosidase. It hydrolyzed phenylphosphonate and reduced resazurin. 16S rRNA, groEL, gyrB, recA, and rpoB sequencing showed that HKU24T occupies a distinct phylogenetic position among the Leptotrichia species, being most closely related to Leptotrichia trevisanii. Using HKU24T groEL, gyrB, recA, and rpoB gene-specific primers, fragments of these genes were amplified from one of 20 oral specimens. Based on phenotypic and genotypic characteristics, we propose a new species, Leptotrichia hongkongensis sp. nov., to describe this bacterium.

关键词： Leptotrichia hongkongensis Bacterium Blood culture Anaerobic bacteria Novel species

Romance of the three domains:how cladistics transformed the classifi cation of cellular organisms

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Protein & Cell 2013年第9期4卷 664-676页

作者： Chi-Chun Ho Susanna K.P.Lau Patrick C.Y.Woo Department of Microbiology The University of Hong KongHong KongChina State Key laboratory of Emerging Infectious Diseases The University of Hong KongHong KongChina Research Centre of Infection and Immunology The University of Hong KongHong KongChina Carol Yu Centre of Infection The University of Hong KongHong KongChina

Cladistics is a biological philosophy that uses genealogi-cal relationship among species and an inferred sequence of divergence as the basis of classifi *** review critically surveys the chronological development of bio-logical classification from Aristotle through our post-genomic era with a central focus on *** 1957,Julian Huxley coined cladogenesis to denote splitting from *** 1960,the English translation of Willi Hennig’s 1950 work,Systematic Phylogenetics,was published,which received strong opposition from phenet-icists,such as numerical taxonomists Peter Sneath and Robert Sokal,and evolutionary taxonomist,Ernst Mayr,and sparked acrimonious debates in *** 1977-1990,Carl Woese pioneered in using small subunit rRNA gene sequences to delimitate the three domains of cellu-lar life and established major prokaryotic *** has since dominated *** being compatible with modern microbiological observations,*** with unusual phenotypes,restricted expression of charac-teristics and occasionally being uncultivable,increasing recognition of pervasiveness and abundance of horizon-tal gene transfer has challenged relevance and validity of *** mosaic nature of eukaryotic and prokary-otic genomes was also gradually *** the mid-2000s,high-throughput and whole-genome sequencing became routine and complex geneologies of organisms have led to the proposal of a reticulated web of *** genomics only indirectly leads to understanding of func-tional adaptations to ecological niches,computational modeling of entire organisms is underway and the gap between genomics and phenetics may soon be *** are not expected to settle as taxonomic classifi cations shall remain subjective to serve the human scientist,not the classifi ed.

关键词： cladistics phenetics phylogeny classifi ca-tion evolution

quantum self-attention neural networks for text classification

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Science China(Information Sciences) 2024年第4期67卷 301-313页

作者： Guangxi LI Xuanqiang ZHAO Xin WANG Institute for quantum Computing Baidu Research Centre for quantum Software and Information University of Technology Sydney QICI quantum Information and Computation Initiative Department of Computer ScienceThe University of Hong Kong Thrust of Artificial Intelligence Information HubHong Kong University of Science and Technology(Guangzhou)

An emerging direction of quantum computing is to establish meaningful quantum applications in various fields of artificial intelligence, including natural language processing(NLP). Although some efforts based on syntactic analysis have opened the door to research in quantum NLP(QNLP), limitations such as heavy syntactic preprocessing and syntax-dependent network architecture make them impracticable on larger and real-world data sets. In this paper, we propose a new simple network architecture, called the quantum selfattention neural network(QSANN), which can compensate for these limitations. Specifically, we introduce the self-attention mechanism into quantum neural networks and then utilize a Gaussian projected quantum self-attention serving as a sensible quantum version of self-attention. As a result, QSANN is effective and scalable on larger data sets and has the desirable property of being implementable on near-term quantum devices. In particular, our QSANN outperforms the best existing QNLP model based on syntactic analysis as well as a simple classical self-attention neural network in numerical experiments of text classification tasks on public data sets. We further show that our method exhibits robustness to low-level quantum noises and showcases resilience to quantum neural network architectures.

关键词： quantum neural networks self-attention natural language processing text classification parameterized quantum circuits

Giant nonlinear Hall effect in twisted bilayer WSe2

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National Science Review 2023年第4期10卷 97-104页

作者： Meizhen Huang Zefei Wu Jinxin Hu Xiangbin Cai En Li Liheng An Xuemeng Feng Ziqing Ye Nian Lin Kam Tuen Law Ning Wang Department of Physics and Center for quantum Materials The Hong Kong University of Science and Technology William Mong Institute of Nano Science and Technology The Hong Kong University of Science and Technology

The recently discovered nonlinear Hall effect(NHE) in a few non-interacting systems provides a novel mechanism for generating second-harmonic electrical Hall signals under time-reversal-symmetric conditions. Here, we introduce a new approach to engineering an NHE by using twisted moiré *** found that the twisted WSe2bilayer exhibited an NHE when the Fermi level was tuned to the moiré flat bands. When the first moiré band was half-filled, the nonlinear Hall signal exhibited a sharp peak with a generation efficiency that was at least two orders of magnitude greater than those obtained in previous experiments. We discuss the possible origins of the diverging generation efficiency in twisted WSe2based on resistivity measurements, such as moiré-interface-induced correlation effects and mass-diverging-type continuous Mot transition. This study demonstrates not only how interaction effects can combine with Berry curvature dipoles to produce novel quantum phenomena, but also the potential of NHE measurements as a new tool for studying quantum criticality.

关键词： nonlinear Hall effect moiré superlattice twisted bilayer WSe2 continuous Mott transition electron-electron correlation effect

Unidirectionally aligned bright quantum rods films,using T-shape ligands,for LCD application

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Nano Research 2022年第6期15卷 5392-5401页

作者： Maksym F.Prodanov Chengbin Kang Swadesh K.Gupta Valerii V.Vashchenko Yuhao Li Minchao Qin Xinhui Lu Abhishek K.Srivastava State Key laboratory of Advanced Displays and Optoelectronics Technologies and Centre for Display Research Department of Electronics and Computer EngineeringThe Hong Kong University of Science and TechnologyClear Water BayHong Kong 999077Hong KongChina Department of Physics The Chinese University of Hong KongShatinHong Kong 999077Hong KongChina

Unidirectionally aligned nanorods(NRs)are of great importance for different applications,including displays,lighting,and ***,many alignment techniques were studied to align quantum rods(QRs).However,the brightness of these films,due to the limited concentration of aligned quantum rods in the film,is not enough for their implementation as brightness enhancement films(BEFs)in *** can be ascribed to the poor miscibility of quantum rods in polymer and strong concentration dependence of the polarized *** ligands of NR are very important for the alignment and *** this article,we proposed a ligand combination comprising T-shape promesogenic phosphonic acid,which on being photoaligned provides mutually parallel alignment of the quantum *** T-shape ligands enable the fabrication of hybrid films with a QRs concentration as high as 10 wt.%–20 wt.%retaining high brightness and luminescence polarization ***,we used these films in the in-plane switching(IPS)display backlight that shows the color gamut up to 121%of national television system committee(NTSC)(CIE1931),liquid-crystal display(LCD)efficiency up to 7.9%,power efficacy 103±2 nits/W,and the high brightness of~550±10 ***,the proposed ligands can be used for the alignment of a variety of nanorods.

关键词： quantum rods(QRs) ligands alignment display luminous efficiency