Distribution, Biotransformation, Pharmacological Effects, Metabolic Mechanism and Safety Evaluation of Platycodin D: A Comprehensive Review.

Platycodonis Radix (Jiegeng), the dried root of Platycodon grandiflorum, is a traditional herb used as both medicine and food. Its clinical application for the treatment of cough, phlegm, sore throat, pulmonary and respiratory diseases has been thousands of years in China. Platycodin D is the main active ingredient in Platycodonis Radix, which belongs to the family of pentacyclic triterpenoid saponins because it contains an oleanolane type aglycone linked with double sugar chains. Modern pharmacology has demonstrated that Platycodin D displays various biological activities, such as analgesics, expectoration and cough suppression, promoting weight loss, anti-tumor and immune regulation, suggesting that Platycodin D has the potential to be a drug candidate and an interesting target as a natural product for clinical research. In this review, the distribution and biotransformation, pharmacological effects, metabolic mechanism and safety evaluation of Platycodin D are summarized to lay the foundation for further studies.

Mental Health and Self-Determination Profiles of the Diverse Population of Medical Students in Malaysia During the COVID-19 Pandemic (preprint)

Introduction: Medical schools throughout the world were forced to modify their programming during the COVID-19 pandemic. In Malaysia, virtual learning plans were implemented for non-clinical programming, while clinical posting modifications were designed to meet local SOPs. The prolonged enforcement of these modifications to undergraduate medical education will have affected student experiences, including well-being. Since these feelings can relate to perceived relatedness, autonomy, and competence, it is important to identify any potential factors that may lead to reduced intrinsic motivation in students. It is also important to consider how demographic features may contribute to student perspectives, which can be studied using the unique diversity represented by Malaysian students. Methods: A quantitative survey was distributed to Malaysian medical students to assess their overall wellbeing, autonomy in educational decision making, student experiences, and position on changes to graduation timing. Intrinsic components were identified using Principal Component Analysis and were aligned with the three needs for self-determination, namely relatedness, autonomy, and competence. Finally, trends in responses for participants from various sub-populations were assessed using ANOVA testing. Results: Responses were collected from 442 students representing 23 accredited Malaysian medical schools. Upon validation and reliability testing, eight components were identified with themes relating to: mental health, social concerns, communication, timing of modifications, depth of learning, and student-centred learning. Of these, gender was related to mental health, student-centred learning, and delayed graduation, while stage was related to student-centred learning and delayed graduation in addition to concerns about depth of learning and timing of modifications. Interestingly, ethnicity was related to differences in opinions about delayed graduation and income was related to social concerns. Conclusion: The results of this study indicate that, while students were satisfied in general with the content and delivery of their programmes given the circumstances, there is evidence to suggest negative effects on emotional wellbeing, expression of student voice, due to the modifications that were made. Additionally, these feelings related to the three motivational needs, suggesting that students were experiencing a dampened motivational profile during the pandemic. Further, motivational profiles were distinct between student sub-groups, providing insight for developing appropriate and inclusive accommodations moving forward.

Implications of Delay in Compulsory Mask Wearing -- A What-if Analysis (preprint)

We investigate the impact of the delay in compulsory mask wearing on the spread of COVID-19 in the community, set in the Singapore context. By using modified SEIR-based compartmental models, we focus on macroscopic population-level analysis of the relationships between the delay in compulsory mask wearing and the maximum infection, through a series of scenario-based analysis. Our analysis suggests that collective masking can meaningfully reduce the transmission of COVID-19 in the community, but only if implemented within a critical time window of approximately before 80 - 100 days delay after the first infection is detected, coupled with strict enforcement to ensure compliance throughout the duration. We also identify what is called a point of no return, a delay threshold of about 100 days that results in masking enforcement having little significant impact on the Maximum Infected Values.

Bringing Physical Physics Classroom Online -- Challenges of Online Teaching in the New Normal (preprint)

The onset of the COVID-19 pandemic in 2020 has greatly impacted all forms of social activities globally, including traditional classroom activities across all levels of instruction (kindergarten to universities). While many countries have opted for suspension of lessons, this cannot continue indefinitely and alternative means to continue lessons must be developed. While online and blended learning (including MOOCs) have been an active subject of research and discourse during the pre-pandemic days, onset of the pandemic has suddenly created an immediacy to such means of course delivery, better than any administrator or teaching committee could have done. This creates both a gap and tension in terms of successful and engaging content delivery, where traditional modes of synchronous content delivery is now forced to be brought online. Yet, the situation provides educators with an opportunity to explore the merits and weaknesses of online learning. Thus, this article seeks to outline the challenges and paradigm shifts involved in such synchronous online learning as a replacement for traditional classroom learning, following our experience at SUTD of conducting a full 13-week online physics course between May to August 2020. At the same time, we reflect on the merits brought about by the availability of such technologies that can potentially be translated to the physical physics classrooms.