N_CityU103/16
3D Design Algorithms and Dexterous Robotic Sewing for Customized Garment Fabrication

Hong Kong Principal Investigator: Dr Pan Jia (City University of Hong Kong)
Mainland Principal Investigator: Dr Zhang Xinyu (East China Normal University)

Long known as the world's factory for the clothing industry, the Pearl River Delta (PRD) has been a major growth engine driving the global economy for the past 30 years. Less well known is the fact that jobs in this sector remain persistently tedious and menial, and that a growing number of factories there are struggling with both rising wages and an acute shortage of workers. This confluence of economic and demographic trends has made manufacturing automation more crucial than ever to the clothing industry's future vitality.

What's more important, the increasing demands for customized garments also adds to the necessity of applying advanced manufacturing automation techniques in the clothing industry. Mass-produced ready-made clothes became popular due to their low price. However, since each person's body dimension usually has a small deviation from standard sizes, there exist many complaints about not being able to find properly fitting clothes. The only solution available nowadays is the bespoke tailoring, which is too expensive for ordinary consumers. However, consumers are becoming more fastidious about the garment's quality in terms of fitness, fashion, and personality. It is widely expected that the consumption of customized clothes would be the future trend in the clothing business.

Customized garment manufacturing presents a very different and more formidable set of technical challenges than, say, automobile manufacturing: deformable cloth pieces of varying shapes must be stitched together into 3D functional structures; zippers, belts, and other accessories must be connected to clothes; parts and assemblies must be continuously inspected via visual and tactile feedback, through multiple stages of stitching process. These tasks require manual dexterity and perception skills that lie beyond the capabilities of today's industrial robots.

This research proposes a solution in which sophisticated robots are augmented by intelligent algorithms and compliant grippers to achieve highly diversified, small-lot and personalized garments fabrication with high efficiency and flexibility. To customize a cloth, a customer will first use computer-aided-design techniques to achieve personalized design, and then preview the dressing effect of the designed garments using virtual-reality and physically-based simulation. Next, the customer sends designs to the personalized manufacturing center, where fabrication steps like pattern making and sewing will be completed by intelligent robots. The ready-to-wear garments will be stored in the automated warehouse, and finally be delivered to end-users via modern logistics networks.

N_CUHK403/16
Quantum Simulation of Dynamical Many-body Physics by Solid-state NMR

Hong Kong Principal Investigator: Prof Liu Renbao (The Chinese University of Hong Kong)
Mainland Principal Investigator: Prof Peng Xinhua (University of Science and Technology of China)

We propose a theoretical and experimental joint project on quantum simulation of dynamical many-body physics of nuclear spins in solids using solid-state NMR.

Quantum dynamics of many-body systems is important for quantum information processing in general and for quantum simulation in particular. In cold atom systems studies on quench dynamics, by abruptly switching the interactions of cold atoms and then monitoring the subsequent quantum evolutions, have revealed many interesting aspects of dynamical many-body physics such as dynamical phase transitions. To explore the physics and applications of dynamical quantum many-body systems to their full potential, it is desirable to have more controllable and measurable systems and toolkits.

A novel, highly flexible method for quantum simulation is solid-state NMR. Liquid-state NMR has been successfully applied to demonstrate quantum information processing and quantum simulation for a few qubits. However, it cannot be scaled up to large numbers of qubits. On the contrary, solid-state NMR involves interactions among many nuclear spins in a lattice. It has been demonstrated that the many-body interactions of nuclear spins in solids can be engineered by dynamical decoupling with a great deal of flexibility. The quantum evolution of interacting nuclear spins in solids can be monitored by quantum interferometry.

Here we will employ solid-state NMR for quantum simulation of dynamical quantum many-body physics. The previous collaboration between the mainland team and Hong Kong team has revealed that the dynamical quantum evolutions of nuclear spin systems are deeply related to thermodynamics in the complex planes (such as Lee-Yang zeros and phase transitions of non-Hermitian Hamiltonians). In this project, we will carry out a systematic study in theories and in experiments on the physical effects in solid-state NMR systems. We will design and implement dynamical decoupling to engineer the effective interactions between nuclear spins in solids to investigate the quantum evolutions of interacting nuclear spins, and establish connections between the nuclear spin dynamics and dynamical phase transitions and thermodynamics in the complex plane of parameters. The theoretical and experimental studies will be carried out in Hong Kong and mainland teams, respectively.

This joint project will contribute to develop a new platform for quantum simulation of quantum and dynamical phase transitions of non-equilibrium systems. It will serve to broaden and deepen the academic connections between mainland China and Hong Kong.

N_CUHK407/16
Investigation of Technology and Mechanism of in/ex Vivo Stem-cell Differentiation by Femtosecond Laser

Hong Kong Principal Investigator: Dr Kong Siu-kai (The Chinese University of Hong Kong)
Mainland Principal Investigator: Dr He Hao (Shanghai Jiao Tong University)

Stem cell therapy (SCT) is of great potential to treat a wide range of diseases. Clinically, a safe, reliable and controlled protocol to induce stem cells to differentiate to replace those lost for disease is a prerequisite for SCT. Although methods through genetic manipulation, biochemical induction and different modes of physical stress and contacts have been developed in research laboratories, these methods for SCT are challenging and may not be effective when applied clinically in human beings. In fact, only a handful of cases have been approved in clinical trials to date. Recently, our work showed that, without the use of biochemical materials or physical contact, expression of key osteogenic regulators and markers for differentiation could be activated solely by a femtosecond laser (fsL) in human mesenchymal stem cells (MSCs) isolated from the cavity of exfoliated deciduous teeth. Based on these observations, we hypothesize in this proposal that multi-photon excitation using fsL is a minimally-invasive and clean (on-and-off mode) method to modulate molecular signaling system in MSCs thereby instructing them to differentiate into osteoblasts (bone formation cells). In this project, we will isolate MSCs first and then employ a fsL to induce them to differentiate into osteoblasts using the standard osteogenic culture medium approach as a reference. Also, we will clarify the underlying mechanism in vitro and investigate the possible applications of this scheme in vivo. Moreover, we will build a droplets-in-oil microfluidics device to stimulate the MSCs by a fsL in a one-cell-in-one-well (droplet) format in a lab-on-a-disc for single cell analysis in a high-throughput manner. The fact that a procedure is experimentally successful at cell level does not automatically mean that it is useful in vivo. Therefore we will test whether the in vitro procedures have the same beneficial effect in vivo using bone and teeth regeneration as models. All experiments will be conducted in agreement with the guidelines for humane treatment of animals in Hong Kong. It is expected that data from our study will demonstrate a safe and feasible tool to induce stem cells to differentiate and our results will provide evidence to augment the rationale for using laser and stem cells in clinical trials to treat bone disorders.

N_CUHK415/16
Epigenetic Mechanism of Mitoflashes Facilitating Early Phase of Reprogramming

Hong Kong Principal Investigator: Prof Chan Wai-yee (The Chinese University of Hong Kong)
Mainland Principal Investigator: Prof Liu Xingguo (Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences)

Recently, it was reported that individual mitochondria undergo spontaneous bursts of superoxide generation with ΔΨm dissipation, called mitoflashes, which occur randomly in space and time and exhibit all-or-none properties. The system of reprogramming gives us a powerful tool to study epigenetics. We found that mitoflash could trigger the demethylation of Nanog promoter through recruiting Tet2 in the early phase of somatic cells reprogramming (Cell Metabolism, 2016). In this project, we would focus on the mechanism that mitoflash regulates epigenetic status in reprogramming. Our research will include three parts: (1) to study how mitoflash affects global DNA methylation pattern during the early phase of reprogramming; (2) to study the molecular mechanisms of mitoflash in regulating the demethylation of DNA; (3) to identify the signaling pathway regulated by DNA demethylation under mitoflash changes during reprogramming. Based on the success of our past collaborations, we believe combining efforts of our two groups would reveal the new mechanisms which mitochondrial signals regulate epigenetics.

N_CUHK416/16
Expression and Functional Characterization of LBX1 in Adolescent Idiopathic Scoliosis

Hong Kong Principal Investigator: Prof Cheng Jack Chun-yiu (The Chinese University of Hong Kong)
Mainland Principal Investigator: Prof Qiu Yong (Drum Tower Hospital of Nanjing University)

Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional spinal deformity with unknown etiology. The prevalence in Hong Kong is 3-4% and occurred predominantly in adolescent girls. If left untreated, the deformity may deteriorate, particularly in patients who are still undergoing skeletal growth, resulting in cardiopulmonary compromise and other complications affecting quality of life. Despite the high prevalence and the associated with morbidities in severe cases, the current main treatment modality with bracing and corrective surgery remain unsatisfactory. Although there have been many different hypotheses proposed, the etiology of AIS remains to be elucidated.

From recent large-scale GWAS study, we and other groups have demonstrated a strong association between AIS and SNPs near the ladybird homeobox 1 (LBX1) locus, a finding that was replicated across different ethnic groups. However, little is known of the biological role of LBX1 except that it may be involved in embryonic muscle cell formation and neural tube development. Our pilot data showed a generalized higher transcriptional level of LBX1 mRNA in the paraspinal muscle with significantly higher expression at the convex side at the apical region of the major curve in AIS patients. Our recent pilot study indicated potential interaction of LBX1 and Wnt/β-catenin signaling on abnormal paraspinal muscle development in AIS. In contrast, LBX1 mRNA was down-regulated in AIS bone biopsies, particularly in patient with systemic low bone mineral density (BMD). Although low BMD is an independent prognostic factor for curve progression in AIS, however, the underlying mechanism and whether opposite LBX1 expression in muscle and bone results in abnormal interaction remains poorly understood.

We hypothesize that LBX1 expression discrepancy between convex and concave side of the apical region of the major curve could affect myogenic proliferation and differentiation via Wnt/β-catenin signaling pathway, resulting in abnormal muscle mass/strength and through its abnormal biochemical interaction with vertebral bones, could contribute either to the curve initiation or progression in AIS. The proposed study aims to characterize the expression profile of LBX1 in bone and muscle tissues in AIS and to conduct biological functional validation with cellular and transgenic mouse models. This will shed light on understanding the biological role of LBX1 and potential interaction between the convex and concave side of the deep paraspinal muscle in affecting the muscle and vertebral bone quality and the development/progression of spinal deformity in AIS that might inform potential future therapeutic strategies targeting at the functional muscle-bone unit locally and systemically. N_HKUST625/15
Functional and in vivo study of the Neuroligin and Itch Interaction

N_CUHK421/16
Comprehending Mechanisms of Refractory Stroke in Symptomatic Intracranial Atherosclerotic Disease: An Interdisciplinary Study by Advanced Neuroimaging and Computational Fluid Dynamics

Hong Kong Principal Investigator: Prof Leung Thomas Wai-hong (The Chinese University of Hong Kong)
Mainland Principal Investigator: Prof Liu Jia (Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences)

Intracranial atherosclerotic disease (ICAD) accounts for 30-50% of ischemic strokes in Chinese, constituting a huge socio-economic burden. Despite contemporary medical treatment, the risk of stroke recurrence in ICAD may reach 23% in the first year. One important reason behind the high treatment failure rate is a poor appreciation of the underlying diverse stroke mechanisms. While neuroimaging and computational techniques now allow in-depth delineation of plaque morphology, composition and cerebral rheology, a better understanding on the interplay between these factors may inform and improve ICAD secondary stroke prevention. Thus, in the current study, we aimed to depict plaque morphology, composition and cerebral hemodynamics in ICAD patients by 3-dimensional rotational angiography (3DRA), high-resolution MR imaging (HR-MRI), transcranial Doppler ultrasound (TCD), and a dynamic computational fluid dynamics (CFD) model; and to understand the governance of plaque vulnerable features and cerebral hemodynamics on the risk and mechanisms of stroke attributed to ICAD.

The proposed project will consist of 2 sub-studies: Study I will be a retrospective case-control study and Study II will be a prospective cohort study. We shall recruit acute ischemic stroke patients due to ICAD. Through 3DRA, HR-MRI, TCD and a CFD model, we shall derive and correlate 3 critical factors of atherosclerotic plaques, namely morphology, composition and rheological parameters at the immediate vicinity of symptomatic ICAD lesions. We shall determine their individual effect and interactions on the risk of stroke relapse and mechanisms of cerebral ischemia in ICAD. While the retrospective data in Study I will demand a static generic CFD model, a dynamic CFD model based on prospective patient-specific imaging and real-time physiological measurements will be employed in Study II.

The proposed project will enhance our understanding of stroke mechanism in ICAD, the most dominant stroke subtype in Chinese. The results may rectify current loopholes and improve secondary stroke prevention by fostering more effective personalized treatment. In a longer term, the improved prognosis of stroke patients may alleviate the substantial socio-economic burden of stroke in China. Furthermore, the cohesive cross-disciplinary hub formed among bioengineers, clinical neurologists, neuro-interventionists, radiologists, mathematicians, and computer scientists through this project also represents an innovative approach to biological research.

N_CUHK430/16
Source Characteristics of Induced Earthquakes Associated with Shale Gas Production in Weiyuan, Sichuan

Hong Kong Principal Investigator: Prof Yang Hongfeng (The Chinese University of Hong Kong)
Mainland Principal Investigator: Prof Chu Risheng (Institute of geodesy and geophysics, Chinese Academy of Science)

Earthquakes can generate strong shaking and cause significant damage and casualty. To reduce the losses from earthquakes demands a better understanding of the physics of this natural hazard. In the past decade, new concerns have been raised regarding assessment of the hazards and risks of earthquakes, as a number of earthquakes have been caused by anthropogenic processes, termed induced earthquakes. Most of these anthropogenic processes are made in developing new energy resources so are inevitable. Therefore, assessment of earthquake hazard associated with these activities is critical. Although induced earthquakes have been extensively found in a variety of geologic settings, many critical questions regarding these intriguing phenomena remain poorly understood, such as whether they had indeed been triggered by human activities and if so, how they had been induced. In this proposal, we plan to tackle these questions by conducting an integrated seismic and geomechanical investigation at the Weiyuan shale gas reservoir (WSGR), Sichuan, China.

Shale gas industry has not been vastly developed in China until 2009, by which 26 Billion RMB have been invested in exploration and evaluation of shale gas resources. The WSGR is one of the major achievements and thus has been established as a national demonstration base to further develop shale gas industry in China. A number of earthquakes have occurred near the reservoir shortly after the production, likely induced by hydraulic fracturing, a technique commonly used in extracting gas from shale. Assessment of the seismic risks is not only critical for production security and local community near Weiyuan, but also plays a significant role in developing shale gas industry in China. This is a proposal to conduct an integrated investigation of seismicity near the WSGR and to advance our understanding of mechanisms and characteristics of induced seismicity, so as to mitigate potential risks associated with the rapid development of shale gas industry.

One of the challenges to investigate induced seismicity is the paucity of seismic network with sufficiently good coverage. We will first deploy a dense seismic network with 80 seismic instruments and then derive precise location, reliable focal mechanisms, and other source parameters of the local earthquakes. Systematic laboratory measurements of poroelastic and seismic properties of core samples representing the reservoir and cap rocks will be conducted. Eventually we will develop a 3D geomechanical model with quantitative constraints from synthesizing the rock physics properties measured in laboratory and field observations of the seismological data.

N_CUHK434/16
Development of Efficient Gene Carriers Based on Self-assembled DNA Nanostructures and Understanding Their Interactions with the Cell

Hong Kong Principal Investigator: Prof Choi Jonathan Chung-hang (The Chinese University of Hong Kong)
Mainland Principal Investigator: Prof Zhang Chuan (Shanghai Jiao Tong University)

Intracellular delivery of nucleic acids is a key prerequisite for realizing the potential of gene therapy, yet conventional delivery approaches such as viral vectors, cationic liposomes and inorganic nanoparticles often suffer from issues related to cellular toxicity, immunogenicity, and lack of biocompatibility. “Self-assembled DNA nanostructures” represent an attractive alternative for overcoming these challenges, owing to their low cytotoxicity, high structural versatility, and natural ability to enter mammalian cells without the aid of transfection agents.

In this proposal, we seek to develop next-generation self-assembled DNA nanostructures that can facilitate the delivery of functional nucleic acids (e.g., DNA, siRNA, miRNA) into the cell. To do so, we will address two key challenges that hamper the performance of DNA nanostructures as gene carriers. On the biology front, our basic understanding in how DNA nanostructures interact with the cell remains incomprehensive, because most previous studies merely focus on one nanostructure type and one cell type. Here, by preparing a series of DNA nanostructures with various sizes and shapes, we will systematically evaluate their transfection efficiency, interrogate their mechanisms for cellular uptake, and monitor their trafficking and degradation events inside the cell as a function of size and shape. On the materials front, most DNA nanostructures often encounter premature degradation by intracellular nucleases upon initial cellular entry, drastically reducing the potency of the nucleic acids to be carried. Here, we will develop two methods of enhancing the intracellular stability of DNA nanostructures, namely capping and polymeric encapsulation. Ultimately, we will evaluate the potential of using our stabilized, size- and shape-optimized DNA nanostructures to deliver functional nucleic acids into the cell for modulating its cellular responses. As a proof-of-concept, we will deliver siRNA into cancer cells for regulating the expression of specific oncogenes as well as miRNA into stem cells for triggering their differentiation into specific cell types.

Our research will inform valuable design rules for DNA nanostructures as delivery carriers for intracellular applications. Our optimized gene delivery platform may open new technological avenues for modulating the responses of cell types with limited transfection efficiency.

N_CUHK437/16
Mathematical and Numerical Study of Non-conforming Finite Element Methods for Maxwell’s Equations in Inhomogeneous Media and Related Inverse Problems

Hong Kong Principal Investigator: Dr Zou Jun (The Chinese University of Hong Kong)
Mainland Principal Investigator: Dr Duan Huoyuan (Wuhan University)

In this project we will propose some new non-conforming finite element methods for solving Maxwell's equations in inhomogeneous media and their related inverse problems, and develop a systematic mathematical theory to help analyse and understand the stability and convergence of these non-conforming methods, especially for the challenging cases with high frequency solutions, non-H2 solutions, or solutions with very low regularities in the entire physical domain. It is known that the solutions to Maxwell's equations are generally not in the H1 space, caused possibly by non-smooth domains, inhomogeneous media, singular source data, singular boundary and interface data, etc. We shall focus on the very general physical situations where the solutions to Maxwell equations are only piecewise smooth, with a local regularity being possibly lower than H2 in each medium subdomain. Non-conforming finite elements have been widely studied and applied for numerical solutions of various partial differential equations. However, they have still not been developed successfully for solving Maxwell's equations in inhomogeneous media and three dimensions, because of the very low global regularities of their solutions. This project shall fill the gap, and make an important contribution to numerical solutions of various Maxwell systems in inhomogeneous media. The non-conforming finite element methods that are developed in this project are efficient and effective not only for Maxwell's equations, but also for many other partial differential equations that can be described by curl and div operators. These new non-conforming finite element methods are also applied for solving the related mathematically ill-posed Maxwell inverse problems, and their stability and convergence shall be established.

N_HKBU202/16
Unraveling the fundamental mechanism of synergistic effect in ternary bulk-heterojunction blends for photovoltaic applications

Hong Kong Principal Investigator: Prof So Shu Kong (Hong Kong Baptist University) Mainland Principal Investigator: Prof Hao Xiaotao (Shandong University)

Organic photovoltaic (OPV) cells based on semiconducting polymers are very appealing because they are light-weight and flexible. For OPV cells using the bulk-heterojunction (BHJ) concept, a semiconducting polymer (electron donor D) is mixed with a fullerene acceptor (A) to form the light-absorbing active layer. In a span of about 7 years, the power conversion efficiencies (PCEs) of BHJs have increased steadily from about 5 to exceeding 11%. To obtain higher PCEs, new approaches are needed. In the ternary approach, besides the donor and acceptor, a third component is added to form a ternary blend layer. Much has been done to develop ternary blends. The third component should be able to enhance at least one of the following: (a) optical absorption, (b) carrier transport, (c) energy transfer, and (d) morphology of the blend films. Simultaneously, the additional component should not generate detrimental side-effects. The ternary blend concept should have the potential of pushing the PCEs further. So far, only limited successes have been achieved with the best PCEs hovering just under 11%. Efforts have been done to clarify how the ternary component enhances the PCEs through factors (a)-(d). But very often, these factors are entangled. The lack of systematic study is hindering the progress. In this proposal, we suggest to use benzodithiophene-based family of polymer donors, and fullerene as acceptors. The photovoltaic properties of their binary blends and ternary blends OPV cells will be investigated. We will identify several model systems and collaboratively study the optoelectronic properties of these ternary systems. The Hong Kong team will focus on the transport and electronic properties. The mainland team will focus on the optical properties. Through these studies, we wish to identify the mechanisms of synergistic effect in ternary bulk-heterojunction blends for photovoltaic applications and establish some guidelines for future device applications. Hole conduction appears to be the bottleneck for many BHJ OPV cells. Therefore, understanding how to improve hole conduction will help to fabricate thick films OPV cells. Finally, a sound understanding of the fundamental mechanisms should allow us to further improve some under-performed polymers that have been developed in the past few years.

N_HKU706/16
Construction and mechanism of supertough/superwetting nanocrystalline interface on flexible polymeric membranes for water/oil separation

HK Principal Investigator: Dr Chuyang Tang (The University of Hong Kong)
Mainland Principal Investigator: Prof Fu Liu (Ningbo Institute of Material Technology and Engineering)

Discharge of oily wastewater from various industries and frequent oil spill accidents have caused tremendous environmental and ecological damages. Thus, separating oil from water is an important research field with both fundamental scientific significance and practical importance. Membrane separation can be a highly cost-effective technology for oil/water separation, where a superwetting membrane surface is designed to preferentially separate water from oil (or oil from water). A critical concern for membrane-based oil/water separation is the long-term membrane stability. In the current project, we aim to develop supertough/superwetting membranes for efficient oil/water separation. The micro- and nano-scale pore structure and morphology will be tuned using appropriate copolymers. Inorganic nanoparticles will be synthesized and functionalized to tune the membrane surface wetting behavior. The stability of the synthesized membranes will be investigated by stressing them under severe chemical and mechanical exposure conditions. Additional filtration experiments will be conducted to verify the long term performance stability and anti-fouling performance. The project addresses pollution prevention, waste minimization, and resource recovery, which are associated with major environmental and socioeconomic benefits.

N_HKU712/16
Ultrafast spectro-temporal measurement based on photonic integration

HK Principal Investigator: Dr Kenneth Kin Yip Wong (The University of Hong Kong)
Mainland Principal Investigator: Prof Xinliang Zhang (Huazhong University of Science and Technology)

Optical spectrum acts as an essential information carrier and spectroscopy is one of the most essential techniques in photonic measurement. Therefore, the ultrafast real-time spectrum acquisition is highly demanded for some process analyses, as well as a critical technology to observe the dynamic evolution of some physical structures. This joint project mainly focuses on the ultrafast spectro-temporal measurement based on the photonic integration technology, which is also known as parametric spectro-temporal analyzer (PASTA). While PASTA was initially proposed and demonstrated by the Hong Kong PI in leveraging the temporal Fourier transform and time-lens phenomena to realize the fastest spectroscopy at 100-MHz frame rate; its preliminary fiber-based implementation was limited in its conversion bandwidth and footprint. The strategic partnership with the Mainland PI’s expertise in the photonic integrations not only overcomes this limitation, but it will also enable the system to achieve larger nonlinear-to-dispersion ratio and observation bandwidth. The synergy will transform various ultrafast applications, including ultrafast spectroscopy/microscopy for capturing dynamic phenomenon and real-time full-field information characterization.

N_HKU725/16
Study of the degradation behaviors and osteogenic effects of Mg-Si based biomaterials

HK Principal Investigator: Prof Kenneth Man Chee Cheung (The University of Hong Kong)
Mainland Principal Investigator: Prof Yufeng Zheng (Peking University)

Patients with bone fracture or deformity are commonly treated by surgical intervention and fixation implants made of titanium alloys and 316L medical grade stainless steel. These implants are no longer useful to the patient following bone healing. If left inside the human body, the implant can potentially increase the stress-shielding effect at the bone-implant interface, eventually resulting in bone loss at the junction and failure of fixation. For this reason, the development of a biodegradable metal for bone fracture fixation is a desirable advance. Among various biodegradable materials, metallic materials such as magnesium alloys remain preferable for orthopaedic implantation, as the mechanical properties of these alloys more closely resemble those of human bone. The major obstacles to clinical use are rapid degradation inside the human body and hydrogen gas release upon degradation, and a range of approaches such as alloying and surface treatment have therefore been adopted to improve degradability and biocompatibility.

Our pilot work has demonstrated that some trace elements (e.g. calcium (Ca), zinc (Zn) and strontium (Sr), as well as silicon (Si) incorporated into magnesium substrate) can enhance implant corrosion resistance, mechanical properties and biocompatibility. The property of enhanced corrosion resistance may be attributed to the formation of a dense oxide layer comprising these additional elements and magnesium matrix, and the reinforcement of mechanical properties to secondary phase precipitation and solid solution strengthening. These bioactive elements are already known to be essential to the osteogenic differentiation and mineralization of bone cells, and to the growth and vascularization of bony tissue. However, little is known about how the combination of these elements into magnesium alloys affects mechanical integrity, cytotoxic effects of released ions, hydrogen gas release under in vivo conditions, biodegradability, in vivo biocompatibility and clinical practicality. Thus, the specific aims of this study include (1) the design and fabrication of a series of magnesium-silicon based binary, ternary, quaternary and quinary (i.e. Mg-Si-(Ca, Sr, Zn)) systems for clinical orthopaedic applications; (2) an investigation of their cold/hot working ability, mechanical and chemical properties; (3) an examination of biodegradation mechanisms and ion release behaviour under simulated conditions; and (4) an evaluation of how biodegradation products (i.e. released ions) influence the viability, adhesion and mineralization behaviour of cells by using in vitro assays and assessment of their effects on new bone formation and resorption, as well as on the biomechanical properties of newly formed bone through in vivo animal testing. If the outcome is favourable, it may revolutionize the future development of orthopaedic implants, benefiting patients worldwide and eliminating the risks of a metallic implant left inside the body or the need to have further surgery to remove it.

N_HKU729/16
Identification of susceptibility genes involved in the pathogenesis and prediction of thyrotoxic periodic paralysis

HK Principal Investigator: Dr Ching Lung Cheung (The University of Hong Kong)
Mainland Principal Investigator: Prof Huai Dong Song (Shanghai Jiao Tong University)

Thyrotoxic periodic paralysis (TPP) is a potential life-threatening complication of thyrotoxicosis. Although all TPP patients were also diagnosed with Graves’ disease (GD) clinically, it is unknown if TPP shares similar pathogenesis to GD. Like GD, genetics is also an established and important factor contributing to the pathogenesis of TPP. However, the genetic variation that identified by us in the previous study only explains only part of the occurrence of TPP. In addition, the pathogenesis of TPP remains largely unknown. In this study, our aims are to: (1) identify susceptibility genes of TPP and to determine whether TPP is a specific subtype of GD; (2) identify the molecular mechanism of TPP; and (3) create an animal model of TPP: a model for studying gene and environmental interaction with TPP. This collaboration with the mainland team is expected to elucidate the pathogenesis of TPP and potentially identify a clinical useful genetic marker to predict incident TPP among GD patients.

N_HKUST603/16
Environmental Behaviors of Arsenic-loaded Zero-Valent Iron Nanoparticles in Subsurface Systems

HK Principal Investigator: Prof Lo Irene Man-Chi (The Hong Kong University of Science and Technology)
Mainland Principal Investigator: Prof Hu Liming (Tsinghua University)

Arsenic is one of the most toxic, naturally occurring groundwater contaminants and long-term exposure/ingestion can cause poisoning and even death. Nanoparticles appear to be a promising pollutant removal material, among which nanoscale zero-valent iron (nZVI) has been extensively studied to remediate arsenic-contaminated groundwater. nZVI removes arsenic through adsorption and/or co-precipitation onto its surface, leading to the formation of arsenic-loaded nZVI (As-loaded nZVI). But that is not the end of the problem—what happens to the As-loaded nZVI? Its transport and fate have become an environmental concern, and it is critical to evaluate the overall efficacy of nZVI-based in-situ groundwater remediation and more importantly to assess the environmental risk of the contaminants (e.g., arsenic) that are associated with nZVI during its transport in subsurface environments. The ultimate objective of the proposed project is to obtain a fundamental understanding of the environmental behaviors of original nZVI and As-loaded nZVI under natural conditions and evaluate the risk associated with the release of arsenic from As-loaded nZVI.

In this project, we will investigate the aggregation and sedimentation characteristics of the original nZVI and As-loaded nZVI to determine the stability under different geochemical conditions. Then the immobilization, transport, and remobilization of the original nZVI and the As-loaded nZVI in the saturated porous media will be evaluated using batch-scale and column tests, and arsenic adsorption by nZVI and desorption from the As-loaded nZVI will be systematically investigated under different geochemical conditions. Besides, large-scale 2D and 3D physical modelling will be conducted to investigate the transport process and fate of the original nZVI and As-loaded nZVI at various subsurface conditions. A mathematical modelling with numerical simulation will be developed to simulate the transport and fate of nZVI, and predict the potential environmental risk of using nZVI for subsurface remediation. The results of this project will advance the current knowledge of the application of nZVI for groundwater remediation and the associated risks in restoring sites contaminated with arsenic, and hence provide the scientific basis for groundwater quality management.

N_HKUST605/16
Hybrid structures of low-dimensional functional oxide thin films and 2D semiconductors: design, fabrication, and interface control

HK Principal Investigator: Prof Wang Jiannong (The Hong Kong University of Science and Technology)
Mainland Principal Investigator: Prof Wang Hong (Xi’an Jiaotong University)

The rapid development of new layered 2D materials has provided us an opportunity to explore their hybrids with conventional functional materials (semiconductors, dielectric materials, ferroelectric materials). The nature of Van de Waals (VdW) bonding between layers in new 2D materials means that such materials can be easily combined with conventional functional thin films by VdW over-growth or mechanical transfer to form so-called hybrid structures. The hybrid structures can enhance performance of hosting materials and generate new functionalities. The project is aim to investigate the design, fabrication and interface control the hybrid structures of low-dimensional functional oxide thin films and 2D semiconductors. We will study the fancy properties in the hybrid structures between ferroelectric, piezoelectric thin films and new 2D materials. For all fabricated hybrid structures we will investigate the influence of interface and defect to understand the origin of the novel properties and to tailor the mechanism of multifunctional properties of the nanocomposites. The results will provide important theoretical and experimental basis for the design and fabrication of new magnetic storage, magnetic detector and spin Hall device, as well as to explore the potential applications of this kind of novel composites in electronic devices.

N_PolyU503/16
Development of Beclin1-Specific Autophagy Modulators to Inhibit Lung Cancer Cell Proliferation

HK Principal Investigator: Dr Zhao Yanxiang (The Hong Kong Polytechnic University)
Mainland Principal Investigator: Prof Wang Renxiao (State Key Laboratory of Bioorganic and Natural Products Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences)

Lung cancer is one of the deadliest cancers in China. Molecular targeted therapies provide effective treatment of late-stage lung cancer patients. However, lung cancer cells are notoriously refractory and quickly develop resistance by activating mutations in oncogenes. Therefore, there is an urgent need for novel anti-lung cancer therapies based on novel molecular targets and mechanisms.

Autophagy plays a multi-faceted role in various types of cancer. Beclin-1 is known as an essential autophagy protein, which mediates autophagy and directly attenuates the oncogenic EGFR signaling and inhibit tumor progression in lung cancers. Beclin1 recruits UVRAG, a critical autophagy enhancer, through its coiled coil domain and forms a UVRAG-containing Beclin1-VPS34 complex to promote autophagy and enhance lysosomal degradation of EGFR. We hypothesize that small-molecule compounds targeting the Beclin1-UVRAG interaction may serve as a novel approach to the regulation of autophagy. To be specific, we propose to develop small-molecule compounds that can bind to the Beclin-1 coiled coil domain to strengthen the Beclin1-UVRAG interaction. Such compounds are expected to promote the Beclin1-mediated autophagy, increase the flux of lysosomal EGFR degradation, attenuate the oncogenic EGFR signaling and consequently suppress the proliferation of lung cancer cells, and therefore may have the potential to be developed into new anti-lung cancer therapies.

The Hong Kong team and the Mainland team, with common research interest and complementary technical expertise, form a synergistic team to tackle this challenging problem. For this project, we aim to integrate the biochemistry and oncology expertise of the Hong Kong team with the molecular modelling and organic synthesis expertise of the Mainland team to carry out structure-based design, chemical synthesis and functional characterization of autophagy modulators targeting Beclin-1. Working together, we hope to identify potent Beclin1-targeting compounds to inhibit lung cancer proliferation.

N_PolyU518/16
Experimental and Numerical Studies on Geomechanics of Methane Hydrate-bearing Sediments in South China Sea During Gas Production

HK Principal Investigator: Dr Leung Yat-fai (The Hong Kong Polytechnic University)
Mainland Principal Investigator: Dr Li Dong-liang (Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences)

Methane hydrates are crystallines formed by intrusion of methane gas into water under high pressure and low temperature conditions, and exist in deep seabed and permafrost regions. They are widely believed to hold the potential to provide energy supplies for future generations, since even conservative estimates on their total volume worldwide are reported to be equivalent to the amount of organic carbon that rivals the summation of world’s oil, natural gas and coal deposits combined. This research investigates the geomechanical properties of hydrate-bearing sediments retrieved from the South China Sea, through comprehensive experimental study to be led by the Guangzhou Institute of Energy Conversion (GIEC), and numerical analyses and interpretation led by The Hong Kong Polytechnic University (PolyU). This project will 1) characterize the petrophysical and geomechanical properties of methane hydrate-bearing sediments in South China Sea; 2) develop an adaptive simulation framework for the prediction of gas production, and the geomechanical response of marine hydrate-bearing sediments during gas production operations; 3) identify key material parameters relevant to the operations through quantitative variance-based sensitivity analyses.

The outcome of this research will be immediately applicable to methane hydrate exploration and gas production in China, meeting the ever-growing energy demands. Meanwhile, the findings will be valuable reference to similar operations around the world.

N_PolyU520/16
Square Concrete-Filled Steel Tubular Columns with Internal High-Strength Steel Confinement

HK Principal Investigator: Prof Teng Jin-Guang (The Hong Kong Polytechnic University)
Mainland Principal Investigator: Prof Feng Peng (Tsinghua University)

In recent years, the need to construct various megastructures such as long-span bridges, super high-rise buildings and large offshore platforms has created ever increasing demands on the load-carrying capacity and ductility of structural members. Concrete-filled steel tubular (CFST) columns, due to their excellent load-carrying capacity, have been widely used in practice. CFST columns may be divided into two types: (1) circular columns, where the concrete is well confined by the steel tube, have an excellent load-carrying capacity and ductility; (2) rectangular columns (including square columns as a special case), where the concrete is less well confined, may not possess sufficient ductility, with the issue of inadequate ductility becoming even more critical if high strength steel and high strength concrete are used to construct the column. The present project aims to develop a novel type of square CFST columns, where high strength steel spirals are used to provide strong confinement to the infilled concrete, so that the ductility and strength of the column are effectively enhanced. The new type of CFST columns maintains the ease for connection to beams but in the meantime is expected to show excellent performance in both load-carrying capacity and ductility; they are especially suitable for use in structures located in seismic regions. In the proposed project, an extensive research programme will be undertaken, involving experimental, numerical and theoretical investigations, with the following objectives: (1) to optimize the combination of the three components (steel tube, concrete and high strength steel spirals); (2) to understand their structural behavior; (3) to establish theoretical strength models; and (4) to develop practical design methods. The outcomes of the project will facilitate the wide practical implementation of this novel type of structural members.

N_PolyU528/16
High-capacitance Wearable Li-ion Batteries using Multi-shelled Metal Oxides and Metallic Textile Electrodes

HK Principal Investigator: Dr Zheng Zijian (The Hong Kong Polytechnic University)
Mainland Principal Investigator: Dr Yang Mei (Institute of Process Engineering, Chinese Academy of Sciences)

To fulfill the requirement of wearable electronics and address current critical challenge in Li-ion batteries, this research project aims to develop high-capacitance flexible Li-ion batteries by combining high-conductive, flexible metallic textiles and multi-shelled metal oxides with high capacitance, and to understand the fundamental materials and device characteristics. Such a materials combination holds great potential for the realization of wearable LIBs with high capacitance, high flexibility, and high durability. Electrochemical activity could be improved by these nanoparticles and the available specific surface, and the volume change and stress during discharge-charge process could be buffered and the transfer rate of electrolyte ions could be accelerated due to the hollow structure. Importantly, the structure could be maintained by the different shells, thereby the stability cycle and life-span could be enhanced. The conductive textiles as current collector could be obtained by solution-based metal deposition on various textiles such as Ni, Cu. The flexible electrodes would be designed to improve the bonding strength between the current collector and active materials. The energy density as well as the power density, conductivity and lifespan would be discussed systematically. The proposed research project is on the basis of the complementary advantages and mutual benefits of both parties. The design and preparation of the flexible composite electrodes will promote the understanding of those fundamental scientific questions in this field. Importantly, a novel, facile, and low-cost method for fabricating flexible textile-based Li-ion batteries will be proposed for the first time, which shall make a significant and immediate impact on the development of energy storage research, smart textiles, flexible/wearable electronics.

N_PolyU531/16
Dynamic Revenue Management and Fleet Management for Stochastic Container Leasing System

HK Principal Investigator: Prof Yan Hong (The Hong Kong Polytechnic University)
Mainland Principal Investigator: Prof Zhang Juliang (Beijing Jiaotong University)

With the substantial upsurge of container traffic, the container leasing company thrives on the financial benefits and operations flexibility of leasing containers requested by shippers. In practice, container lease pricing problem is distinct from a consumer product rental pricing in the light of high value of container, monopolistic supply and oligopolistic demand. Given the characteristics, the leasing company is grappling for the pricing issue.

In the first part, we investigate a monopolist's nonlinear pricing problem in a dynamic environment. In particular, we address finite customer types and analyse the optimal solutions for customers with hire time preference. In addition, we discuss how capacity constraint and dynamic arrivals constrain the optimal solution over time when customers have same/different hire time preference(s).

Advance reservation is one feature for container leasing firm to differentiate customers in the pricing determination process. In the second part, we will consider a dynamic pricing problem with reservations from two aspects—unit demand and multiple-unit demand. The unit demand case corresponds to the master lease in practice. Through modelling as a continuous-time Markov decision process, we will investigate the monotonicity and sensitivity of the optimal allocation and pricing policy. Numerical experiments are conducted to study the effect of reservation on the optimal policy. For the problem with multiple-unit demand, we will employ the concept of multi-modularity to characterize the monotone sensitivity of the optimal policy. Utilizing this property, we will propose a myopic pricing policy to the dynamic pricing problem.

N_PolyU601/16
Preparation of High Performance Cathodes for Li-S Batteries and Their Property and Mechanism Study: Enhancement of Electron and Lithium Ion Transmission and Anchoring of Polysulfides

HK Principal Investigator: Prof Chen Guohua (The Hong Kong Polytechnic University)
Mainland Principal Investigator: Prof Deng Yuanfu (South China University of Technology)

Recently, the development of high energy density secondary battery systems is in urgent need because the existing products cannot meet the high energy requirement of intelligent telecommunication as well as electric vehicles (EV). The secondary battery, Li-S, made of sulfur (S) and lithium metal (Li), has a theoretical energy capacity up to 2600 Wh/kg, with a practical energy density of 400-500 Wh/kg. In addition, sulfur is relatively cheap and environmentally benign. Hence, Li-S can meet the demand from EV, aerospace technologies and large scale energy storage. It has therefore been a hot research focus in the development of high energy capacity secondary batteries. However, lithium polysulfide can easily be dissolved in electrolyte leading to energy capacity degradation and also service life decrease. In order to overcome such a challenge, this project will tackle the following two key problems: (1) anchor the polysulfides by immobilizing them onto activated carbons with micro-meso pores. The carbon framework will be doped with lithium ion conducting materials so as to improve the lithium conductivity. The sulfur loaded activated carbons will then be coated by lithium ion conducting materials to further anchor the lithium polysulfides. Furthermore, lithium sulfides adsorbents will be employed along with the construction of 3-D electric conducting network to realize the optimal immobilization of lithium sulfides, and to balance the electron and ion conductivity. (2) elucidate the synergetic mechanism for composite material, namely lithium ion conducting material coated sulfur-loaded hetero-atom doped carbons - S/HCs@LIC, through theoretical simulation as well as in-situ/ex-situ UV-Vis and other characterization techniques to monitor the physical, chemical and electrochemical behaviors of the system during charge/discharge of the battery. The solution of the two problems can provide theoretical guidance for the making of high capacity sulfur cathode for the Li-S secondary battery.