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Publication Senior activity centres : challenges and possibilities(Centre for Ageing Research and Education (CARE), 2019-10) June Lee May Ling; Normala Manap; Angelique Chan; Balambigai Balakrishnan; Normala Manap; DUKE-NUS MEDICAL SCHOOLPublication Liver-Derived Cell Transfection Model Efficacy for HBV Genotype B Replication/Transcription Is Determined by Complex Host Transcription Factor Network(MDPI, 2021-03-01) Chong, Roxanne Hui-Heng; Khakpoor, Atefeh; Tan, Theresa May-Chin; Lim, Seng-Gee; Lee, Guan-Huei; Dr Atefeh Khakpoor; MEDICINE; DUKE-NUS MEDICAL SCHOOL; BIOCHEMISTRYBackground: Interaction between host transcription factors (TFs) and the viral genome is fundamental for hepatitis B virus (HBV) gene expression regulation. Additionally, the distinct interaction of the TFs’ network with the HBV genome determines the regulatory effect outcome. Hence, different HBV genotypes and their variants may display different viral replication/transcription reg-ulation. Due to the lack of an efficient infection model suitable for all HBV genotypes, the hepatoma cell transfection model is primarily used in studies involving non-D HBV genotypes and variants. Methods: We explored the transcriptome profile of host TFs with a regulatory effect on HBV in eight liver-derived cell lines in comparison with primary human hepatocytes (PHH). We further analyzed the suitability of these models in supporting HBV genotype B replication/transcription. Results: Among studied models, HC-04, as a result of the close similarity of TFs transcriptome profile to PHH and the interaction of specific TFs including HNF4α and PPARα, showed the highest efficiency in regard to viral replication and antigen production. The absence of TFs expression in L02 transfection model resulted in its inefficiency in HBV replication/transcription. Conclusion: These observations help to better design studies on regulatory mechanisms involving non-D HBV genotypes and variants’ gene expression and the development of more efficient therapeutical approaches.Publication Consistency of eating rate, oral processing behaviours and energy intake across meals(2017) McCrickerd, K; Forde, C.G; PHYSIOLOGYFaster eating has been identified as a risk factor for obesity and the current study tested whether eating rate is consistent within an individual and linked to energy intake across multiple meals. Measures of ad libitum intake, eating rate, and oral processing at the same or similar test meal were recorded on four non-consecutive days for 146 participants (117 male, 29 female) recruited across four separate studies. All the meals were video recorded, and oral processing behaviours were derived through behavioural coding. Eating behaviours showed good to excellent consistency across the meals (intra-class correlation coefficients > 0.76, p < 0.001) and participants who ate faster took larger bites (? ? 0.39, p < 0.001) and consistently consumed more energy, independent of meal palatability, sex, body composition and reported appetite (? ? 0.17, p ? 0.025). Importantly, eating faster at one meal predicted faster eating and increased energy intake at subsequent meals (? > 0.20, p < 0.05). Faster eating is relatively consistent within individuals and is predictive of faster eating and increased energy intake at subsequent similar meals consumed in a laboratory context, independent of individual differences in body composition. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.Publication Solid State Transformers (SSTs): A Potential Game Changer for Future Power Distribution Grids(2022-12-14) Jaydeep Saha; NAGA BRAHMENDRA YADAV GORLA; Sanjib K Panda; ELECTRICAL AND COMPUTER ENGINEERINGThe power distribution system is going through a brisk transformation with a higher penetration of renewable energy sources, battery energy storage and DC loads like electric vehicles and data-centres. This has necessitated increasing power electronics based control of power flow within the distribution grid. Solid-state transformer (SST) is an emerging power electronic technology, also referred to as power electronic transformers, energy routers, etc., which is a cascaded combination of power converter cells with medium-frequency isolation. SSTs are used to interface a medium-voltage (MV) network (e.g. the utility distribution grid) with a low-voltage (LV) network (e.g. a microgrid). It has been shown in recent literature that for MVAC-LVDC applications (e.g. where solar energy or battery integration is required), SSTs have proven to be a competitive technology, in terms of efficiency, power-density and cost, compared to the on-load tap-changer (OLTC) transformers. This tutorial will discuss various aspects of control, reliable operation, practical implementation and optimal design of SSTs. It will start off with a brief introduction of the SST technology and its potential in future smart-grid paradigm, as well as provide a succinct overview of the various SST topologies. Secondly, the discussion will shift to a particular topology called Cascaded Modular SST (CMSST), where modelling and control aspects will be discussed in detail. One of the key challenges in adapting power electronic transformers is its reliability. Therefore, special attention is given to fault diagnosis and fault tolerant control schemes for SSTs. Thirdly, the practical implementation aspect of the SST based on industrial design and product requirements will be discussed in some detail. The critical aspects of design layouts, design margins, costing analysis on long run, component choices will be dealt with. Some critical components such as high frequency transformer mandate custom design and development due to insulation requirements. The need for development of custom tools for design is also discussed here based on the design of a 6.6 kV SST’s hardware implementation. Subsequently, a multi-objective optimal design strategy for the grid-connected SST technology will be discussed. Here, a hybrid (analytical+numerical) model based local optimization strategy, followed by a global optimization strategy using limited number of optimal datasets fed to low data-hungry machine-learning algorithms will be explained which aim to reduce the overall computational burden. Apart from design optimization results for a realistic 22 kV, 1 MVA SST, scaled-down experimental measurements and subsequent validation for a 1.5 kV, 15 kVA SST’s design showing the merits of the discussed strategy. Finally, the tutorial will conclude with the main takeaway message from this tutorial and the potential areas/ applications where SST technology has the capability to dominate in the near future.Publication National and International Postgraduate Study guidelines(Prime Medical College, Rangpur, Bangladesh, 2018-01-27) Sazzad, Md Faizus; Dr Md Faizus Sazzad; SURGERYPublication Moving Boundary Simulation of Iron-Zinc Sacrificial Corrosion under Dynamic Electrolyte Thickness Based on Real-Time Monitoring Data(ELECTROCHEMICAL SOCIETY, 2020-02-17) SAEEDIKHANIGERAEI, MOHSEN; VAN DEN STEEN, NILS; T. L. SUDESH L. WIJESINGHE; VAFAKHAH, SAREH; TERRYN, HERMAN; BLACKWOOD,DANIEL J; MATERIALS SCIENCE AND ENGINEERINGThe electrolyte film thickness condensation and evaporation is an important parameter for complexity of atmospheric corrosion. Atmospheric corrosion rate of zinc at the west coast of Singapore was measured for one year using an electrical resistance monitoring system. The analysis of the data reveals that significant corrosion rates only occur at specific hours on dry days. The beginning of this period corresponds to falling temperature and rising relative humidity resulting in the formation of a film of moisture on the zinc surface and the end corresponds to a point that this film dries as the temperature increases. This finding allowed the drying rate of the moisture film to be estimated for input into a moving boundary simulation model of the galvanic corrosion in scratched and zinc coating samples. The simulation results showed that the maximum corrosion rate occurs at electrolyte thickness of about 8 μm. Moreover, the simulation suggested that cut-edge is a more harmful defect than scratch, which was confirmed by the appearance of iron corrosion products on atmospheric exposed cut-edge samples whereas scratched samples were not corroded after one week of exposure. Finally, moving boundary simulation allowed to predict the changes to the geometry of the corroding electrodes.Publication FIBER REINFORCED COMPOSITE AND METHODS OF FORMING THE SAME(2005-11-02) GOPAL, RENUGA; FUJIHARA, KAZUTOSHI; RAMAKRISHNA, SEERAM; CHEW, CHONG-LIN; GANESH, VIJAY KUMAR; LOH, POEY LING; FOONG, WENG CHIONG KELVIN; PREVENTIVE DENTISTRY; RESTORATIVE DENTISTRY; MECHANICAL ENGINEERING; DIVISION OF BIOENGINEERINGA fiber reinforced composite is formed using a shrinkable die. A composite of fiber and resin is placed in the die and is compressed by shrinking the die to form a desired transverse cross-section. Optionally, the die is bent along its lengthwise extent to shape the composite in the die. After shrinking and optional shaping, the composite is cured to form the fiber reinforced composite.Publication Complexity of Daily Physical Activity Is More Sensitive Than Conventional Metrics to Assess Functional Change in Younger Older Adults(MDPI, 2018-07-01) Zhang, Wei; Schwenk, Michael; Mellone, Sabato; Paraschiv-Ionescu, Anisoara; Vereijken, Beatrix; Pijnappels, Mirjam; Mikolaizak, A Stefanie; Boulton, Elisabeth; Jonkman, Nini H; Maier, Andrea B; Klenk, Jochen; Helbostad, Jorunn; Taraldsen, Kristin; Aminian, Kamiar; Prof Andrea Britta Maier; MEDICINEThe emerging mHealth applications, incorporating wearable sensors, enables continuous monitoring of physical activity (PA). This study aimed at analyzing the relevance of a multivariate complexity metric in assessment of functional change in younger older adults. Thirty individuals (60–70 years old) participated in a 4-week home-based exercise intervention. The Community Balance and Mobility Scale (CBMS) was used for clinical assessment of the participants’ functional balance and mobility performance pre-and post-intervention. Accelerometers worn on the low back were used to register PA of one week before and in the third week of the intervention. Changes in conventional univariate PA metrics (percentage of walking and sedentary time, step counts, mean cadence) and complexity were compared to the change as measured by the CBMS. Statistical analyses (21 participants) showed significant rank correlation between the change as measured by complexity and CBMS (ρ = 0.47, p = 0.03). Smoothing the activity output improved the correlation (ρ = 0.58, p = 0.01). In contrast, change in univariate PA metrics did not show correlations. These findings demonstrate the high potential of the complexity metric being useful and more sensitive than conventional PA metrics for assessing functional changes in younger older adults.Publication Phase 2 study of anti-human cytomegalovirus monoclonal antibodies for prophylaxis in hematopoietic cell transplantation(American Society for Microbiology, 2020-01-01) Maertens, J; Logan, AC; Jang, J; Long, G; Tang, JL; Hwang, WYK; Koh, LP; Chemaly, R; Gerbitz, A; Winkler, J; Yeh, SP; Hiemenz, J; Christoph, S; Lee, DG; Wang, PN; Holler, E; Mielke, S; Akard, L; Yeo, A; Ramachandra, S; Smith, K; Pertel, P; Segal, F; Assoc Prof Liang Piu Koh; MEDICINE; DUKE-NUS MEDICAL SCHOOLHuman cytomegalovirus (HCMV) can cause significant disease in immunocompromised patients, and treatment options are limited by toxicities. CSJ148 is a combination of two anti-HCMV human monoclonal antibodies (LJP538 and LJP539) that bind to and inhibit the functions of viral HCMV glycoprotein B (gB) and the pentameric complex, consisting of glycoproteins gH, gL, UL128, UL130, and UL131. In this phase 2, randomized, placebo-controlled trial, we evaluated the safety and efficacy of CSJ148 for prophylaxis of HCMV in patients undergoing allogeneic hematopoietic stem cell transplantation. As would be expected in the study population, all the patients (100%) reported at least one treatment-emergent adverse event. There were 22 deaths during this study, and over 80% of the patients receiving placebo or CSJ148 developed at least one adverse event of grade 3 or higher severity. No subject who received antibody developed a hypersensitivity- or infusion-related reaction. CSJ148-treated patients showed trends toward decreased viral load, shorter median duration of preemptive therapy, and fewer courses of preemptive therapy. However, the estimated probability that CSJ148 decreases the need for preemptive therapy compared to placebo was 69%, with a risk ratio of 0.89 and a 90% credible interval of 0.61 to 1.31. The primary efficacy endpoint was therefore not met, indicating that CSJ148 did not prevent clinically significant HCMV reactivation in recipients of allogeneic hematopoietic cell transplants.Publication Two kinds of embryo research: four case examples(BMJ PUBLISHING GROUP, 2022-05-09) Savulescu, Julian; Labude, Markus; Barcellona, Capucine; Huang, Zhongwei; Leverentz, Michael Karl; Xafis, Vicki; Lysaght, Tamra; Dr Zhongwei Huang; DEAN'S OFFICE (MEDICINE); MECHANOBIOLOGY INSTITUTE; OBSTETRICS & GYNAECOLOGYThere are ethical obligations to conduct research that contributes to generalisable knowledge and improves reproductive health, and this should include embryo research in jurisdictions where it is permitted. Often, the controversial nature of embryo research can alarm ethics committee members, which can unnecessarily delay important research that can potentially improve fertility for patients and society. Such delay is ethically unjustified. Moreover, countries such as the UK, Australia and Singapore have legislation which unnecessarily captures low-risk research, such as observational research, in an often cumbersome and protracted review process. Such countries should revise such legislation to better facilitate low-risk embryo research. We introduce a philosophical distinction to help decision-makers more efficiently identify higher risk embryo research from that which presents no more risks to persons than other types of tissue research. That distinction is between future person embryo research and non-future person embryo research. We apply this distinction to four examples of embryo research that might be presented to ethics committees. Embryo research is most controversial and deserving of detailed scrutiny when it potentially affects a future person. Where it does not, it should generally require less ethical scrutiny. We explore a variety of ways in which research can affect a future person, including by deriving information about that person, and manipulating eggs or sperm before an embryo is created.