In this roadmap, two-dimensional materials including graphene, black phosporus, MXenes, covalent organic frameworks, oxides, chalcogenides, and others, are highlighted in energy storage and ...conversion.
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Energy storage and conversion have attained significant interest owing to its important applications that reduce CO2 emission through employing green energy. Some promising technologies are included metal-air batteries, metal-sulfur batteries, metal-ion batteries, electrochemical capacitors, etc. Here, metal elements are involved with lithium, sodium, and magnesium. For these devices, electrode materials are of importance to obtain high performance. Two-dimensional (2D) materials are a large kind of layered structured materials with promising future as energy storage materials, which include graphene, black phosporus, MXenes, covalent organic frameworks (COFs), 2D oxides, 2D chalcogenides, and others. Great progress has been achieved to go ahead for 2D materials in energy storage and conversion. More researchers will join in this research field. Under the background, it has motivated us to contribute with a roadmap on ‘two-dimensional materials for energy storage and conversion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Herein, the nano-sized niobium pentoxide (Nb2O5) with different morphologies and phase structures are synthesized through a very simple thermal treatment method, including the pseudohexagonal Nb2O5 ...nanosheets and pseudohexagonal Nb2O5 nanoparticles, orthorhombic Nb2O5 nanoparticles. The synthesized pseudohexagonal Nb2O5 nanosheets and orthorhombic Nb2O5 nanoparticles exhibit better cycling and rate performance than the pseudohexagonal Nb2O5 nanoparticles due to the different morphologies and phase structures.
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The morphology, size and phase of the material play a crucial role in its electrochemical performance. Herein, the nano-sized niobium pentoxide (Nb2O5) with different morphologies and phase structures are synthesized through a very simple thermal treatment method, including the pseudohexagonal Nb2O5 nanosheets and pseudohexagonal Nb2O5 nanoparticles, orthorhombic Nb2O5 nanoparticles. The synthesized pseudohexagonal Nb2O5 nanosheets and orthorhombic Nb2O5 nanoparticles exhibit better cycling and rate performance than the pseudohexagonal Nb2O5 nanoparticles due to the different morphologies and phase structures. The T-Nb2O5-700 nanoparticles show the higher capacity (175mAh/g) than that of TT-Nb2O5-500 nanosheets (127 mAh/g) and TT-Nb2O5-600 nanoparticles (39 mAh/g) at a current density of 50 mA/g and good rate performance with a capacity of 140 mAh/g at 1.0 A/g. The excellent rate capability and cycling stability of orthorhombic T-Nb2O5 may be ascribed to the dominant contribution of pseudocapacitive effect. This material has the great potential as a practical high-rate anode material for lithium-ion batteries.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Background
COVID-19 pandemic has resulted in significant strain on healthcare resources and this requires diligent resource re-allocation. We aim to describe the incidence and outcomes of in-hospital ...cardiac arrest (IHCA) during this period as compared to non-pandemic period.
Methods
We conducted a retrospective study in a tertiary care hospital in Singapore. The study compared the incidence and outcomes of code blue activations over a 3-month period from March to May 2020 (COVID-19 period) with the same months in 2019 (pre-COVID-19 period). The primary outcome of the study was the rate of survival to hospital discharge for IHCA. The secondary outcomes included incidence of all code blue activation per 1000 hospital admissions, incidence of IHCA per 1000 hospital admissions.
Outcomes
The rate of survival to hospital discharge for IHCA was 5.88% in the COVID-19 period as compared to 10.0% in the pre-COVID-19 period odds ratio (OR), 0.72; 95% confidence interval (CI), 0.26-1.95. Compared to pre-COVID-19 period, there were more IHCA incidences per 1000 hospital admissions in the COVID-19 period (1.86 vs 1.03; OR, 1.81; 95% CI, 0.78-4.41).
Conclusions
The study observed a trend towards higher incidence of IHCA and lower rate of survival to hospital discharge during COVID-19 pandemic compared to pre-COVID-19 period.
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IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, UL, UM, UPUK, VSZLJ
The swelling mechanism is widely used to explain the response of ionic liquids (ILs) or poly(ionic liquid)s (PILs) to moisture. While a fairly broad consensus has been attained, there are still some ...phenomena that are not well explained. As a complement to the swelling mechanism, we systematically studied the free volume theory in the rapid response and recovery of PIL humidity performance. We chose poly(1-ethyl-3-vinylimidazolium bromide) (PIL-Br), poly(1-ethyl-3-vinylimidazolium tetrafluoroborate) (PIL-BF
) and poly(1-ethyl-3-vinylimidazolium bis(trifluoromethane sulfonimide)) (PIL-TFSI) as model materials and investigated the impact of PIL structure including anion type, film thickness and affinity to moisture on performance to obtain the humidity sensing mechanism for PILs based on free volume theory. Hence, we can combine free volume theory with the designed PIL structures and their affinity with moisture to obtain a high concentration of free ions in PIL sensing films. Furthermore, the PIL humidity sensors also show fast, substantial impedance changes with changing humidity for real-time monitoring of the human respiratory rate due to a fast response and recovery performance. Therefore, our findings develop a new perspective to understand the humidity performance of PILs based on free volume theory, resulting in fast response and recovery properties realized by the rational design of PIL sensing films.
Purpose - The purpose of this study was to characterise the physiochemical properties of selected exotic seasonal tropical fruits available in Singapore.Design methodology approach - A total of 11 ...seasonal tropical fruits including cempedak, chiku, custard apple, jackfruit, longkong, mangosteen, red jambu, pearl jambu, rambutan, salak and starfruit were analyzed for their sugars, organic acids and free phenolic acids composition using liquid chromatographic methods. Total phenolic content (free and bound), total soluble solids and pH were determined using Folin-Ciocalteu method, refractometer and pH meter, respectively.Findings - Fructose, glucose and sucrose were the main sugars in all the fruits. Cempedak had the highest sucrose concentration, while custard apple had the highest content of fructose and glucose. Malic and citric acids were the major organic acids in most of the fruits, except for pearl jambu and red jambu where succinic acid was the dominant acid. The total phenolic content varied from 122.94 to 712.20 mg gallic acid equivalent (GAE) kg fresh weight (FW). Ferulic (0.631 mg kg) and sinapic acids (1.506 mg kg) were the predominant free phenolic acids in custard apple, while caffeic acid was the main free phenolic acid in jackfruit, salak and starfruit.Originality value - The paper demonstrates that the physiochemical characteristics of the 11 tropical fruits varied markedly, which is responsible for the differential flavour and stability. The findings are useful for epidemiological research and predicting the degree of ripeness, stability and post-harvest processing required for these fruits.
Aqueous electrolyte‐based batteries have attracted increasing attention because of nonflammability, low cost, high power density, and environmental friendliness. However, the low energy density of ...aqueous lithium‐ion batteries caused by the narrow stable electrochemical window of water and electrode materials with low capacity severely limits their further development. In this regard, the development of metal anodes with high specific capacity shows excellent prospects. For example, metal zinc and aluminum anodes have high theoretical specific capacity, rich resources, and environmental friendliness, and can be used as promising anodes for high‐energy‐density aqueous rechargeable metal batteries. Unfortunately, metal anodes usually face balance issues with regard to stability and activity associated with dendrite growth and undesired side reactions in water‐based electrolytes, which is still a great challenge for aqueous metal batteries. In this review, various aqueous metal batteries including aqueous rechargeable metal batteries and aqueous metal–air batteries are summarized and highlighted. Recent advances in the design of high‐safety aqueous electrolytes and the strategies for metal anode protection are comprehensively reviewed. In addition, emerging challenges and some perspectives on the development of high‐energy‐density aqueous metal batteries are included.
In this review, various aqueous metal batteries including aqueous rechargeable metal batteries and aqueous metal–air batteries are summarized, especially including recent advances in the design of high‐safety aqueous electrolytes and the strategies for metal anode protection. Moreover, emerging challenges and some perspectives on the development of high‐energy‐density aqueous metal batteries are presented.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Introduction: The night float (NF) system has been instituted in some hospitals in Singapore to improve the working hours and wellbeing of junior doctors. There have been concerns of compromised ...learning and patient safety with NF. The objective of this study is to compare clinical competency outcomes, based on existing assessment framework, between post-graduate year 1 (PGY1) doctors working on NF versus traditional call (TC) systems. The secondary aim was to explore patient safety outcomes between these groups of PGY1s.
Methods: Data on the formal assessments of PGY1s using the Entrustable Professional Activities (EPAs) and medical errors were prospectively collected between May 2021 and April 2022 from two hospitals that employed different on-call systems. Data was analysed descriptively. Categorical data was analysed using the Chi-square test or Fisher’s exact test where appropriate.
Results: One hundred and ninety-three PGY1s consented to the study. There was no statistically significant difference in the clinical competency of PGY1s in both groups. The number of PGY1s who had ‘needs improvement’ scores in a detailed EPA was not significantly different (9.0% in the NF group versus vs 3.7% in the TC group (p = 0.14)). They nonetheless passed the overall core EPA and no PGY1 failed their postings. No serious reportable medical errors occurred in either group.
Conclusion: PGY1s who worked on NF are equally competent compared to those who worked on TC based on the EPA assessment matrix. Patient safety is not compromised by PGY1s working on NF.
Keywords: Clinical competence, Float, Junior doctor, Patient safety, Wellbeing
In pursuit of high‐performance cathode materials for lithium‐ion batteries with high energy and power densities, porous LiFe0.4Mn0.6PO4/CNF free‐standing electrodes have been successfully prepared ...through a facile ionic liquid (IL) assisted electrospinning method. Owing to the hierarchical porosity and N‐doped carbon layer derived from the ionic liquid, the resulting electrodes exhibited superior electrochemical performances with an improvement of conductivity and pseudocapacitive contribution, delivering a discharge capability of 162.7, 133.5, 114.5, and 102.6 mAh g−1 at the current rates of 0.1, 1, 5, and 10 C, respectively. It is highly expected that this facile IL‐assisted electrospinning method will lead to further developments for other phosphate‐based free‐standing electrodes, which offers a new route in designing polyanionic cathodes for high‐performance Li‐ion batteries.
Cathode materials: Porous LiFe0.4Mn0.6PO4/CNF free‐standing electrodes have been successfully prepared through a facile ionic liquid assisted electrospinning method. Owing to the hierarchical porosity and N‐doped carbon layer derived from ionic liquid, the resulting electrodes exhibit superior electrochemical performances with the improvement of conductivity and pseudocapacitive contribution (see figure).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
IntroductionThe COVID-19 pandemic has had a significant impact on medical education, with many institutions shifting to online learning to ensure the safety of students and staff. However, there has ...been a decline in in-person attendance at medical schools across the UK and worldwide following the relaxation of social distancing rules and the reinstation of in-person teaching. Importantly, this trend has been observed prior to the pandemic. While reflected within the literature, there is currently no systematic review describing these changes. We aim to find out how medical students’ attendance is changing as documented within the literature and its impact on their educational outcomes.Methods and analysisThis systematic review will follow the guidelines of the Centre of Research and Dissemination, Meta-analyses of Observational Studies in Epidemiology and Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We will search the major databases of Medline via Ovid, Embase via Ovid, Scopus, Web of Science, British Education Index via EBSCOhost and ERIC via EBSCOhost.Two reviewers will independently screen each paper and extract data, with a third reviewer for dispute resolution. All studies reporting on medical students from various universities, both graduate and undergraduate and describing changes in attendance and/or students‘ educational outcomes will be included. Risk of bias in individual studies will be assessed using the Newcastle-Ottawa Scale and confidence in cumulative evidence will be evaluated using the Grading of Recommendations, Assessment, Development and Evaluation-Confidence in the Evidence from Reviews of Qualitative Research approach. A narrative synthesis of the findings from all included studies will be reported.Ethics and disseminationEthical approval is not required for this systematic review of existing publicly available literature. We will subsequently aim to publish the results of this systematic review in a peer-reviewed journal.
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