News

PolyU research reveals major healthcare and communication challenges for migrant domestic workers in Hong Kong

Migrant domestic workers support many Hong Kong working families in childcare and household duties but their own personal needs seldom receive significant attention. The Department of English and Communication at The Hong Kong Polytechnic University (PolyU) has conducted research into the health and other structural issues faced by migrant domestic workers in Hong Kong, especially during the COVID-19 pandemic. Findings reveal that health literacy and access to information and facilities are crucial to their well-being. The researchers have interviewed more than 700 Filipino and Indonesian migrant domestic workers and surveyed more than 400 to investigate their life stories and well-being in Hong Kong, covering topics from narratives about their (traumatic) experiences, health literacy and healthcare needs to their communication networks. In view of the increasing number of workers driven by growing demand for domestic elderly care in Hong Kong, these studies aimed to highlight the significance of cultivating favourable conditions for workers. Prof. Hans LADEGAARD, Professor of the Department of English and Communication at PolyU, said, “Our research shows that Indonesian workers, in particular, face marginalisation and isolation due to language and communication problems and a lack of awareness of their rights. Many took only a three-week Cantonese course before arrival, which clearly does not guarantee their Cantonese proficiency, while most of them are also unable to speak English. Many workers even do not know it is illegal to be paid under the minimum wage or that they are entitled to have 24 hours off once a week. Therefore, it is crucial to prioritise efforts to provide language learning support and to educate these workers about their rights.” Inadequate access to health facilities and information is one major challenge facing these workers. According to Prof. Ladegaard’s research, when the COVID-19 pandemic-induced loneliness, isolation and homesickness put them at higher risk of experiencing depression and anxiety, they only had limited access to support. To address the issue, the team advised that health campaigns be conducted in a language that the workers can understand and that accessible channels such as social media are mobilised for promotion. The research also indicated utilising cartoons and storytelling to be more effective in communicating with migrant populations. Another research study, led by Dr Jeffry OKTAVIANUS, Assistant Professor of the Department of English and Communication, found that community storytelling networks, including interpersonal relationships, community organisations and media outlets, played an essential role in supporting the migrant domestic workers in coping during the pandemic. His research has been published in the journal Health Communication. The study revealed that many workers could not obtain knowledge about effective preventive measures during the pandemic, due to the absence of reliable and accurate information in their native language. Interaction with workers’ communities on social media thus became their major source of informational and emotional support. However, workers were also exposed to fake news through interpersonal networks, which led to adverse effects, such as having a negative psychological impact. Dr Oktavianus remarked, “These networks provide crucial support, but also spread misinformation, creating both opportunities and challenges for empowering marginalised communities.” The research further highlighted the potential of community organisations in debunking hoaxes by disseminating credible news, thereby eliminating uncertainty, refuting misinformation and aiding in understanding the chaotic situation. In this regard, health campaigns are encouraged to utilise community-based storytellers, such as Indonesian organisations or ethnic media, to communicate public health information. Meanwhile, improving digital literacy is also important for helping foreign workers distinguish fake news from real. While the Philippines now has one of the highest breast cancer diagnosis rates in Asia, there is also an increasing number of Filipino workers diagnosed with breast cancer in Hong Kong. Dr Margo TURNBULL, Assistant Professor of the Department of English and Communication, led a research team focusing on the health literacy needs of migrant domestic workers. Published in the journal Quality Health Research, the research study provides a critical examination of how breast cancer and migration impact the lives of these workers. This study again emphasised the importance of health campaigns in workers’ native language and of their access to health facilities, particularly on Sundays, enabling them to receive timely diagnoses and assistance. Dr Turnbull added, “Improving language and communication skills can also increase workers’ effective utilisation of medical resources, alleviate the psychological impacts of having cancer and enhance their confidence in advocating for their healthcare needs.” Currently, Dr Turnbull is working with a cancer support group to co-develop multilingual communication resources that can be used by migrant domestic workers to share information about their diagnosis and care needs with their employers, families and doctors. In light of the structural issues uncovered by the studies, a symposium, “Migrant Worker Lives Matter”, organised by the Department of English and Communication in collaboration with two local migrant worker NGOs, PathFinders and Mission for Migrant Workers, will be held at the PolyU campus on 24 May. The event aims to address the challenges faced by migrant domestic workers and explore ways for Hong Kong to become a more inclusive society.

PolyU-nurtured startup takes lead in implementing territory-wide large-scale liver disease screening programme ; As the first participating institution, PolyU drives translation of research into real-world applications

According to the “2024 Global Hepatitis Report” by the World Health Organization, the number of lives lost due to viral hepatitis is increasing year by year, leading to 1.3 million deaths in 2022, claiming 3,500 lives each day in average, and resulting in it constituting the second leading cause of infectious disease deaths worldwide 1. In response to this global public health issue, Eieling Technology Limited (Eieling Technology), an academic-led startup nurtured and supported by The Hong Kong Polytechnic University (PolyU), has announced its leadership in implementation of the five-year “LiverCare – Hong Kong 10 Million Liver Scans Program” (the Programme), to improve public awareness of liver disease prevention, and promote early detection and treatment to reduce the impact of liver disease. Prof. Christopher CHAO, Vice President (Research and Innovation) of PolyU and Prof. ZHENG Yongping, Henry G. Leong Professor in Biomedical Engineering, Chair Professor of Biomedical Engineering and Director of the Research Institute of Smart Ageing of PolyU, joined by Mr Patrick LAU, Deputy Executive Director of the Hong Kong Trade Development Council; Prof. Walter SETO, Clinical Professor in Gastroenterology and Hepatology of the University of Hong Kong; Dr Grace LAU, Head of the Institute for Translational Research of the Hong Kong Science and Technology Parks Corporation (HKSTP); Mr Xiaojia JIA, Chief Executive Officer of Eieling Technology Limited; and Ms Mildred LAW of the Hong Kong Liver Foundation officiated at the Programme launch ceremony yesterday (16 May). PolyU has long been committed to translating its technologies into real-world applications. The University will support the Programme and become the first institution to conduct the Programme. Starting from July this year, PolyU will conduct liver fibrosis and fatty liver screening for full-time university staff using Liverscan®, a palm-size wireless ultrasound imaging device. Participants are also encouraged to join a two-year follow-up study. From the data collected, the research team will study the importance of a balanced diet and daily exercise, as well as regular liver disease screening for monitoring the progression of liver disease. PolyU believes that the programme can not only improve public awareness of liver disease prevention and promote early detection and treatment, but also help reduce the threat of liver disease to human health. Prof. Chao said, “As a PolyU-nurtured start-up, Eieling Technology actively commercialises the University’s patents. With the support from investors and industries through the innovation and entrepreneurship ecosystem of PolyU, the company is able to translate its technologies into products with a positive impact on society. The launch of the programme marks a milestone for PolyU in contributing to the global public health, reflecting the University's commitment to social responsibility and the translation of scientific research outcomes. In recent years, PolyU has strategically established technology innovation institutes in several cities in the Mainland China, aiming to combine PolyU's unique advantages in basic research and innovation with the robust industrial bases and characteristics of various regions in the Mainland. This initiative promotes research and transformation of core technologies, cultivates innovative talents with knowledge in technology and global vision, and provides a more optimised application platform and scenarios for enterprises. Through these measures, PolyU will continuously strengthen its cooperation with cities in Mainland China, promote regional economic development, and also provide a favorable environment for university researchers to apply theory to practice and commercialise research findings." Eieling Technology, co-founded by Prof. Zheng and his research team in 2018, is a technology development company specialising in advanced medical ultrasound imaging devices designed to screen for liver diseases. Prof. Zheng and his PolyU research team combined transient elastography diagnostic technology with a real-time ultrasound image guided system to develop a solution called Liverscan® for liver fibrosis assessment. Liverscan® is an innovative medical device which, since it is palm-sized, wireless, lightweight and portable, easy to control and economical, allows medical staff to perform liver checkups on patients anytime, anywhere. Prof. Zheng said, “Liver fibrosis can be caused by long-term inflammation of liver tissue, excessive alcohol intake or long-term fatty liver, and may develop into cirrhosis, liver dysfunction, or even liver cancer. We hope that through the ultrasound device Liverscan®, which can lower costs, shorten examination time, facilitate operation and improve measurement accuracy, liver disease assessment and screening will be widely available to people in the community, thereby reducing the number patients with severe liver disease in the coming years significantly.” Eieling Technology has been supported by the PolyU Tech Launchpad Fund and the Incu-Bio Programme of HKSTP, as well as by secured funding from several industrial partners and private investors. Liverscan® has obtained registration approval from the US Food and Drug Administration (FDA510K) and is being used in many well-known hospitals and clinics in Hong Kong, Macau and other places. Eieling Technology is also carrying out clinical research and cooperation with several hospitals in Mainland China. Liverscan® is expected to enter the market in Mainland China after receiving registration approval from the National Medical Products Administration in Q3 this year, and to be launched globally in 2025. 1World Health Organization- “Global hepatitis report 2024”  

PolyU and Huizhou Daya Bay sign a cooperation agreement to establish joint technology and innovation research institute

The Hong Kong Polytechnic University (PolyU) has signed an agreement with the People's Government of Huizhou City and Huizhou Daya Bay Economic and Technological Development Zone for the establishment of PolyU-Daya Bay Technology and Innovation Research Institute. PolyU and Huizhou will unleash their own advantages to jointly translate scientific research outcomes into the core technologies of the local industries in Huizhou.

PolyU study reveals effectiveness of GBGI infrastructure in mitigating urban heat, proposing nine-stage framework for development of a sustainable city

Primarily due to the impact of urbanisation and global warming, urban heatwaves have become a challenging issue worldwide, with Hong Kong persistently experiencing record-breaking high-temperature days. Mitigating urban heat through green and blue infrastructures is essential for creating a sustainable environment. Prof. Hai GUO, Professor of the Department of Civil and Environmental Engineering at The Hong Kong Polytechnic University (PolyU) and global researchers have conducted a first-of-its-kind study on the effectiveness of green interventions in cooling urban heat across various regions that can assist policymakers in prioritising effective interventions to develop sustainable cities. The study findings have been published in the international interdisciplinary journal The Innovation. Globally, the most efficient air cooling was observed in botanical gardens, wetlands, green walls, street trees and vegetated balconies. In light of this, the research team conducted a global review of the effectiveness of green-blue-grey infrastructure (GBGI) in air cooling. GBGI refers to green infrastructures that encompass naturally vegetation-based elements like trees, grass and hedges; blue infrastructures are related to water-based features like pools, lakes and rivers; and grey infrastructures comprise engineered structures including green walls, green facades and roofs. The Study revealed regional and city-specific variations in the effectiveness of GBGI for mitigating urban heat. In Europe, Asia, North America and Australia, the overall cooling effect of GBGI is up to 18.9°C, 17.7°C, 12°C and 9.63°C respectively. In addition, the implementation of green and blue infrastructures has proven to be highly effective in lowering air temperatures globally. While green infrastructures can regulate urban heat through evaporation, transpiration, shading and thermal insulation, blue infrastructures absorb heat and cool the surrounding area through evaporation. In Asian cities, constructed grey infrastructures, especially roof gardens and pergolas, are found to be the most effective for urban cooling. Roof gardens in Singapore achieved the most significant temperature reduction of 17.7°C. Pergolas and green roofs in Japan and South Korea also had substantial impact, resulting in cooling temperatures by 16.2°C and 10.8°C, respectively. Linearly planted hedges and street trees contributed to lowering temperatures by up to 10.8°C. Authorities are advised to plant more street trees, not only for their impressive cooling efficiency but also for their substantial potential to create other positive environmental impacts. The Study also showed notable effects of various GBGI features in mitigating urban heat in Mainland China cities. The most effective means include botanical gardens, wetlands, green walls and attenuation ponds which exhibited temperature reductions of up to 10°C, 9.27°C, 8°C and 7°C respectively. Although the cooling effect ranges are generally similar in the north and south of China, there is variability within the same region. For example, in Beijing, botanical garden could result in up to 10°C temperature decrease while that in Shaanxi province only contributed to 2.7°C. In Hong Kong, parks, green roofs and golf courses were found to play substantial roles in cooling urban heat, resulting in temperature reductions of 4.9°C, 4.9°C and 4.2°C respectively. A “Shining City Project” was proposed by the Hong Kong government in last year’s Policy Address to enhance urban green space. This initiative includes the greening of riverbanks to turn them into flower viewing points and the extensive planting of trees in government venues and at roundabouts on major roads. Prof. Guo said, “With their distinctive location and natural environment, the types of GBGI in Hong Kong are unique. The city features a network of oceans, rivers, wetlands and reservoirs, with remarkable vegetation cover, encompassing approximately 70% of its land area of which country parks occupy around 40%, and possesses a precious natural asset in the Victoria Harbour. Meanwhile, the Government actively promotes GBGI in new development areas and the adoption of green building design in new government projects. These forward-looking initiatives highlight Hong Kong’s dedication to sustainable and resilient urban development.” Globally, the types of GBGI vary significantly across continents due to diverse regional contexts, climate conditions and urban planning priorities. The Study’s GBGI heat mitigation inventory can assist policymakers and urban planners in prioritising effective interventions to reduce the risk of urban overheating and promote community resilience. At this point, the research team has introduced a nine-stage framework to facilitate the implementation of GBGI that outlines stages of stakeholder engagement, feasibility studies, design, policy development, implementation, monitoring, evaluation, and eventual upscaling and replication. Prof. Guo emphasised, “This framework serves as a strategic roadmap, optimising GBGI implementation to maximise benefits. Policymakers should conduct thorough investigation and planning tailored to the specific context and needs of their cities. In Asia, the extensive development of GBGI is a response to challenges posed by rapid urbanisation and cultural preferences that prioritise green areas for community activities, together with environmental goals focused on biodiversity conservation, improved air quality and mitigation of the urban heat island effect. It is crucial for future GBGI implementation to adopt a holistic approach, optimising their multifunctional benefits to effectively address sustainability goals.”

Media Interview: Prof. Wu Bo shares on PolyU’s deep space research

Prof. WU Bo, Fiona Cheung Professor in Spatial Science, Associate Head (Research) of the Department of Land Surveying and Geo-Informatics, and Associate Director of Research Centre for Deep Space Explorations of PolyU shared the University’s deep space exploration research and Hong Kong’s atmosphere of scientific research in a recent interview.  Prof. WU has dedicated himself to photogrammetry, planetary mapping and planetary science research for many years. Regarding the Nation’s  lunar exploration missions, including Chang'e-3, Chang'e-4, Chang'e-5 and Chang'e-6, as well as the Mars exploration project, Prof. WU and his team made use of advanced topographic mapping technologies to evaluate and identify the best landing sites for spacecraft. In addition, PolyU launched the Space Resources Laboratory to properly store and analyse lunar soil, and to conduct biological and material science research. 《Nanfang Daily》Full Interview :  https://polyu.me/3QGEJf7 For more︰https://polyu.hk/qIxgV  

Visit by Delegation of Member of the Standing Committee of the Fujian Provincial People's Congress

A delegation led by Mr LI Jianhui, Member of the Standing Committee of the Fujian Provincial People's Congress and Mr Wang Mingyuan, Mayor of Jinjiang Municipal People’s Government, visited the Hong Kong Polytechnic University (PolyU) on 6 May to exchange views on strengthening cooperation in technology and innovation between Fujian and Hong Kong. The delegation was warmly welcomed by Dr LAM Tai-fai, Council Chairman of PolyU; Prof. Jin-Guang TENG, President of PolyU; Prof. Wing-tak WONG, Deputy President and Provost of PolyU; Prof. Christopher CHAO, Vice President (Research and Innovation) of PolyU, and other representatives from PolyU. Dr LAM stated that as a world-class research-oriented university, PolyU maintains its dedication to focusing on technological innovation and nurturing scientific research talent. He expressed his hope to strengthen collaboration with Quanzhou City, aiming to introduce more globally-renowned technological achievements to be implemented and transformed in the region. This initiative will significantly enhance industrial development and provide innovative drive for the economic and social development of Quanzhou City. Mr LI stated that the PolyU-Jinjiang Technology and Innovation Research Institute (Research Institute) is an important initiative in Fujian Province. The Government is committed to supporting and facilitating the transformation and implementation of the research outcomes. Since the establishment of the Research Institute, both parties have demonstrated strong commitment and exceptional efficiency. Moving forward, PolyU hopes to cooperate with Quanzhou City to jointly establish a comprehensive ecosystem involving with the government, industry, academia, and research institutions, aligning with the major strategic development of Quanzhou City, Fujian Province, and even the nation as a whole.  

PolyU researchers create 2D all-organic perovskites and demonstrate potential use in 2D electronics

Perovskites are among the most researched topics in materials science. Recently, a research team led by Prof. LOH Kian Ping, Chair Professor of Materials Physics and Chemistry and Global STEM Professor of the Department of Applied Physics of The Hong Kong Polytechnic University (PolyU), Dr Kathy LENG, Assistant Professor of the same department, together with Dr Hwa Seob CHOI, Postdoctoral Research Fellow and the first author of the research paper, has solved an age-old challenge to synthesise all-organic two-dimensional perovskites, extending the field into the exciting realm of 2D materials. This breakthrough opens up a new field of 2D all-organic perovskites, which holds promise for both fundamental science and potential applications. This research titled “Molecularly thin, two-dimensional all-organic perovskites” was recently published in the prestigious journal Science. Perovskites are named after their structural resemblance to the mineral calcium titanate perovskite, and are well known for their fascinating properties that can be applied in wide-ranging fields such as solar cells, lighting and catalysis. With a fundamental chemical formula of ABX3, perovskites possess the ability to be finely tuned by adjusting the A and B cations as well as the X anion, paving the way for the development of high-performance materials. While perovskite was first discovered as an inorganic compound, Prof. Loh’s team has focused their attention on the emerging class of all-organic perovskites. In this new family, A, B, and X constituents are organic molecules rather than individual atoms like metals or oxygen. The design principles for creating three-dimensional (3D) perovskites using organic components have only recently been established. Significantly, all-organic perovskites offer distinct advantages over their all-inorganic counterparts, as they are solution-processible and flexible, enabling cost-effective fabrication. Moreover, by manipulating the chemical composition of the crystal, valuable electromagnetic properties such as dielectric properties, which finds applications in electronics and capacitors, can be precisely engineered. Traditionally, researchers face challenges in the synthesis of all-organic 3D perovskites due to the restricted selection of organic molecules that can fit with the crystal structure. Recognising this limitation, Prof. Loh and his team proposed an innovative approach: synthesising all-organic perovskites in the form of 2D layers instead of 3D crystals. This strategy aimed to overcome the constraints imposed by bulky molecules and facilitate the incorporation of a broader range of organic ions. The anticipated outcome was the emergence of novel and extraordinary properties in these materials. Validating their prediction, the team developed a new general class of layered organic perovskites. Following the convention for naming perovskites, they called it the “Choi-Loh-v phase” (CL-v) after Dr Choi and Prof. Loh. These perovskites comprise molecularly thin layers held together by forces that hold graphite layers together, the so-called van der Waals forces – hence the “v” in CL-v. Compared with the previously studied hybrid 2D perovskites, the CL-v phase is stabilised by the addition of another B cation into the unit cell and has the general formula A2B2X4. Using solution-phase chemistry, the research team prepared a CL-v material known as CMD-N-P2, in which the A, B and X sites are occupied by CMD (a chlorinated cyclic organic molecule), ammonium and PF6− ions, respectively. The expected crystal structure was confirmed by high-resolution electron microscopy carried out at cryogenic temperature. These molecularly thin 2D organic perovskites are fundamentally different from traditional 3D minerals, they are single crystalline in two dimensions and can be exfoliated as hexagonal flakes just a few nanometres thick – 20,000 times thinner than a human hair. The solution-processibility of 2D organic perovskites presents exciting opportunities for their application in 2D electronics. The Poly U team conducted measurements on the dielectric constants of the CL-v phase, yielding values ranging from 4.8 to 5.5. These values surpass those of commonly used materials such as silicon dioxide and hexagonal boron nitride. This discovery establishes a promising avenue for incorporating CL-v phase as a dielectric layer in 2D electronic devices, as these devices often necessitate 2D dielectric layers with high dielectric constants, which are typically scarce. Team member Dr Leng successfully addressed the challenge of integrating 2D organic perovskites with 2D electronics. In their approach, the CL-v phase was employed as the top gate dielectric layer, while the channel material consisted of atomically thin Molybdenum Sulfide. By utilising the CL-v phase, the transistor achieved superior control over the current flow between the source and drain terminals, surpassing the capabilities of conventional silicon oxide dielectric layers. Prof. Loh’s research not only establishes an entirely new class of all-organic perovskites but also demonstrates how they can be solution-processed in conjunction with advanced fabrication technique to enhance the performance of 2D electronic devices. These developments open up new possibilities for the creation of more efficient and versatile electronic systems.

PolyU research advocates for privacy protection for Central Bank Digital Currency Development

Privacy protection is pivotal in the development of Central Bank Digital Currency (CBDC). Computing scientists at The Hong Kong Polytechnic University (PolyU) are conducting research to investigate the applications of privacy-enhancing technologies (PETs) to ensure the confidentially and integrity of CBDC transactions.  Prof. Allen Man Ho AU, Professor of the Department of Computing of PolyU, is undertaking research for a white paper by the CBDC Expert Group on privacy protection in CBDC development to enhance confidence among the public and industry. “It is crucial to have CBDC with PET included by design, and we should be transparent for the system design for public inspection,” said Prof. AU.  The research primarily investigates technologies such as pseudonyms, zero-knowledge proofs, ring signatures, and secure multiparty computation. Each of these technologies offers distinct advantages in safeguarding transactional privacy. For instance, zero-knowledge proofs enable transaction verification without disclosing any transactional or personal details, thereby maintaining transactional unlinkability and user anonymity.  Zero-knowledge proofs, also known zero-knowledge cryptography, allows a “prover” to convince a person of the validity of a computation without leaking any information; it is hence referred to as zero-knowledge cryptography. It is seen as a breakthrough technology impacting Web3, a decentralised online ecosystem based on blockchain, because it enables data privacy protection, efficiency improvement and scalability of transparent systems such as blockchain.  Prof. AU, said, “To enhance public and industry confidence in the privacy of CBDCs, we advocate for a comprehensive strategy. First, it is crucial to integrate advanced PETs such as zero-knowledge proofs and secure multiparty computation. These technologies enable transactions while safeguarding user identities and details.”  The research also delves into the challenges of integrating these technologies into CBDC systems, considering different architectural designs—whether public or permissioned blockchains—and whether they employ a UTXO (unspent transaction outputs) or an account-based data model. The analysis addresses critical factors such as scalability, risk, auditability, and, importantly, regulatory compliance. By publishing white papers and actively engaging in public dialogue, the promotion of transparency can help to demystify CBDC technologies and effectively address any concerns within the community. Prof. AU added, “Regular audits and compliance checks conducted by third parties will further validate the integrity of privacy protections.” CBDC is expected to undergo significant advancement in the next five years. More countries will launch pilot programmes to text various use cases, encompassing both retail to wholesale applications. This will include a combination of advanced economies and emerging markets, each delving into CBDCs customised to suit their specific economic and social needs.  In order to sustain its leading position in the CBDC field, Prof. AU said “Hong Kong should continue investing in research and development while promoting innovation through collaborations among the government, industry and academia. The focus is on pioneering new CBDC technologies and use cases that can serve as benchmarks globally.”  Recently, HKMA has commenced Project Ensemble, a new wholesale CBDC project to support the development of the tokenization market in Hong Kong. Since the establishment of the CBDC Expert Group,  PolyU researchers and Prof. AU along with other members have been closely collaborating with HKMA to examine various aspects of CBDCs and related digital currencies. 

Visit by China University of Petroleum

A delegation from the China University of Petroleum, Beijing, visited PolyU for an exchange meeting and laboratories visit on 30 April. Prof. DONG Cheng, Associate Vice President (Mainland Research Advancement) of PolyU, welcomed the delegation and provided an overview of PolyU's latest research developments. During the meeting, PolyU and the delegation  explored opportunities for joint research projects, co-authoring academic publications, and organizing international conferences. At the same time, both parties also shared possible teacher-student exchange activities, such as scholars’ interview, summer programmes and joint student mentoring. The delegation also toured Rock Mechanics Laboratory, Smart Geotechnology Laboratory and Space Resources Laboratory. During the field visits, the guests gained a deeper understanding of PolyU's construction and environmental excellence and scientific development.  

Media interview: PolyU research helps enhance children’s safety awareness in online world

A study led by Dr Jessica LI Chi-mei, Associate Professor of the Department of Applied Social Sciences of PolyU has found that the increase in the usage of electronic devices fuels the opportunity of online child sexual abuse.  Dr. Li and her research team have incorporated the principles of reality therapy to develop 16 sets of educational materials. These resources are designed to assist teachers and social workers in promoting children's awareness of online safety. Full interview:  https://polyu.me/4a1AO2Z https://polyu.me/3UAQfe0 https://polyu.me/4bwwaLV