Safety and potential efficacy of cyclooxygenase-2 inhibitors in coronavirus disease 2019

Objectives While the safety of non‐steroidal anti‐inflammatory drugs in COVID‐19 has been questioned, they may be beneficial given the hyper‐inflammatory immune response associated with severe disease. We aimed to assess the safety and potential efficacy of cyclooxygenase‐2 (COX‐2) selective inhibitors in high‐risk patients. Methods Retrospective study of patients with COVID‐19 pneumonia and aged ≥ 50 years who were admitted to hospital. Adverse outcomes analysed included supplemental oxygen use, intensive care unit admission, mechanical ventilation and mortality, with the primary endpoint a composite of any of these. Plasma levels of inflammatory cytokines and chemokines were measured in a subset. Results Twenty‐two of 168 (13.1%) in the cohort received COX‐2 inhibitors [median duration 3 days, interquartile range (IQR) 3–4.25]. Median age was 61 (IQR 55–67.75), 44.6% were female, and 72.6% had at least one comorbidity. A lower proportion of patients receiving COX‐2 inhibitors met the primary endpoint: 4 (18.2%) versus 57 (39.0%), P = 0.062. This difference was less pronounced after adjusting for baseline difference in age, gender and comorbidities in a multivariate logistic regression model [adjusted odds ratio (AOR) 0.45, 95% CI 0.14–1.46]. The level of interleukin‐6 declined after treatment in five of six (83.3%) treatment group patients [compared to 15 of 28 (53.6%) in the control group] with a greater reduction in absolute IL‐6 levels (P‐value = 0.025). Conclusion Treatment with COX‐2 inhibitors was not associated with an increase in adverse outcomes. Its potential for therapeutic use as an immune modulator warrants further evaluation in a large randomised controlled trial

Development of collagen scaffold with internal channels via indirect rapid prototyping

202 p.The author would like to take this opportunity to acknowledge the contribution of anumber of people for this project. The realization of the project would not have beenpossible without the advice and assistance from them.The author wishes to express her sincere gratitude and appreciation to A/P Chua CheeKai, A/P Leong Kah Fai and Dr. Margam Chandrasekaran, for their invaluable adviceand motivation throughout the project. Appreciation is also extended to As/P AlastairCampbell Ritchie from the School of Mechanical and Aerospace Engineering, NTU,and Mr Timothy Tan and Dr Peter Lee from DNA Center, NIE, for their guidance inthe project. Heartfelt thanks to Ms Hu Quijun, from SIMTech for her guidance andsupport.DOCTOR OF PHILOSOPHY (MAE

Additive manufacturing

Additive manufacturing (AM), or commonly known as 3D printing, gained prominence as part of a suite of technologies that is expected to bring about the Fourth Industrial Revolution, or Industry 4.0. This technology primer aims to showcase the capabilities across the Schools and Research Centres under CoE. While introducing AM, the primer also elucidates the market growth of AM, the exciting new directions undertaken in research development for AM and the current challenges that AM is facing. Applications of AM can be multidisciplinary and span across many fields of study. The research projects featured in this primer are categorised into seven research areas: (1) Aerospace & Defence (2) Biomedical & Food Printing (3) Building & Construction (4) Marine & Offshore (5) AI in Part Design & Manufacturing (6) Novel Materials & 3D Microstructure Engineering (7) Beyond 3D Printing. It is certain that AM will have an important part to play in our journey towards Industry 4.0. There is more to explore with this emerging technology as new players enter the field, bringing new AM methods, materials, and challenges for vastly different applications. Through this primer, we hope to provide a deeper understanding of AM and encourage partnerships between academia and industry to fully unleash the exciting potential of AM and transform the industry through digitalisation of manufacturing

Shape recovery effect of 3D printed polymeric honeycomb : this paper studies the elastic behaviour of different honeycomb structures produced by PolyJet technology

Polymeric honeycombs, with their lightweight, high stiffness-to-weight ratio, and well-developed energy absorption characteristics, have been widely used in engineering applications. In this work, we report the shape recovery effect in a 3D-inkjet-printed honeycomb core. Shape recovery effect, in which the honeycomb slowly recovers back to near its original shape, was observed after the release of compressive loading. Cyclic compression tests were carried out to study the shape recovery characteristics and factors affecting strain recovery in the 3D printed honeycombs. The factors such as honeycomb design shape, loading rate, and number of compressions were investigated. Flatwise compression tests were carried out on three different honeycomb shapes, namely hexagon, triangle, and circular, at three different loading rates. Three stages of shape recovery were identified and general conclusions on the factors affecting the shape recovery were proposed.Agency for Science, Technology and Research (A*STAR)Accepted versionThis work was supported under the A*STARTSRP – Industrial Additive Manufacturing Programme by the A*STAR Science & Engineering Research Council (SERC) [grant number 1325504105]

Lifestyle Product Via 3D Printing: Wearable Fashion

Lifestyle products reflect individuals’ way of life and resonate with personal identity. Some of the examples of lifestyle products are home décor, sports equipment, music instruments and fashion. With up-and-coming companies offering 3D modeling and printing services, consumers can easily access 3D printers to incorporate creativity and personalize touches into individual lifestyles. The use of AM has also helped to create a new platform for customization, direct customer review as well as rapid prototyping of the design concept. In this paper, the feasibility of using 3D printing for lifestyle products, particularly wearable fashion products, will be discussed in terms of the aspects of design processes as well as fabrication processes for the wearable fashion application.Published versio

Laser re-scanning strategy in selective laser melting for part quality enhancement : a review

The selective laser melting (SLM) process is a powder bed fusion additive manufacturing process that can produce near full-density parts for many high value applications in research and industry. Due to the use of laser, the laser re-scanning strategy (LRS) can be employed in SLM. LRS can be defined as the scanning strategy when any one of the part’s layer have more than one passes of laser scan (instead of just one pass under normal scanning circumstances). The laser re-scan can be of any extent, e.g. point, contour, or area. This comprehensive review covers the applications of LRS to enhance bulk properties, improve surface quality, relieve residual stresses, minimize defects and improve part’s accuracy. The challenges and future trends for LRS are also discussed.NRF (Natl Research Foundation, S’pore)Published versio

3D Printed Electronic Tracks for Bio-integrated Free-form Devices

Free-form electronics is driving the bio-medical industry with specifications such as user customization, cost-effectiveness and short response time. Unification of bio- and electronic materials will open doors for wider applications. Integration of electronic materials for bio-sensing is one such field and had garnered much interest. The paper briefly discusses bio-sensors from materials perspective by throwing light on different types of materials and their morphologies for bio-sensors. The advent of 3D-printing, making the fabrication cost effective and easy, has further fueled interest in this field. The paper highlights the work in putting down inkjet printer circuits on biomaterials for various applications.Published versio

Effect of heat treatment on cobalt-chromium-molybdenum alloy fabricated by selective laser melting

Cobalt-chromium-molybdenum (CoCrMo) alloys have excellent corrosion resistance, biocompatibility and strength. As such, they have been widely used in dental applications, such as removable partial dentures, metal frames, customized abutments, crowns and bridges in the anterior and posterior regions. The capability of selective laser melting (SLM), a powder bed fusion additive manufacturing process, to produce customizable products have led to extensive research of using this process for applications in the biomedical field. Several works have been reported on the production of CoCrMo alloys using SLM for various implants. However, there is still limited information on the effect of post process heat treatment on SLM CoCrMo alloys. In this paper, ASTM F75 CoCrMo alloy is fabricated using SLM and underwent heat treatment originally designed for casted ASTM F75 CoCrMo alloy. The mechanical properties of heat treated SLM produced CoCrMo parts are reported and benchmarked against their casted counterparts.NRF (Natl Research Foundation, S’pore)Published versio

The future of skin toxicology testing – three-dimensional bioprinting meets microfluidics

Over the years, the field of toxicology testing has evolved tremendously from the use of animal models to the adaptation of in vitro testing models. In this perspective article, we aim to bridge the gap between the regulatory authorities who performed the testing and approval of new chemicals and the scientists who designed and fabricated these in vitro testing models. An in-depth discussion of existing toxicology testing guidelines for skin tissue models (definition, testing models, principle, and limitations) is first presented to have a good understanding of the stringent requirements that are necessary during the testing process. Next, the ideal requirements of toxicology testing platform (in terms of fabrication, testing, and screening process) are then discussed. We envisioned that the integration of three-dimensional bioprinting within miniaturized microfluidics platform would bring about a paradigm shift in the field of toxicology testing; providing standardization in the fabrication process, accurate, and rapid deposition of test chemicals, real-time monitoring, and high throughput screening for more efficient skin toxicology testing.NRF (Natl Research Foundation, S’pore)Published versio

3D printing of carbon fiber composite : the future of composite industry?

Fabricating composite parts with high fiber loading and design flexibility has always been a challenge. In the recent issue of Matter, Shi and co-workers showed that high fiber loading can be achieved using localized in-plane thermal assisted (LITA) 3D printing. Coupled with robotic arm, it provides a promising way to fabricate lightweight and high-performance continuous fiber reinforced thermoset composites with great design flexibility. Is 3D Printing of carbon fiber composite the inevitable revolution for the composite industry? We discuss the challenges and potentials briefly here toward the future of composite manufacturing