Bioactivity-Guided Isolation of Anticancer Agents from Bauhinia Kockiana Korth.

Background: Flowers of Bauhinia kockiana were investigated for their anticancer properties.Methods: Gallic acid (1), and methyl gallate (2), were isolated via bioassay-directed isolation, and they exhibited anticancer properties towards several cancer cell lines, examined using MTT cell viability assay. Pyrogallol (3) was examined against the same cancer cell lines to deduce the bioactive functional group of the phenolic compounds.Results: The results showed that the phenolic compounds could exhibit moderate to weak cytotoxicity towards certain cell lines (GI50 30 - 86 μM), but were inactive towards DU145 prostate cancer cell (GI50 > 100 μM).Conclusion: It was observed that pyrogallol moiety was one of the essential functional structures of the phenolic compounds in exhibiting anticancer activity. Also, the carboxyl group of compound 1 was also important in anticancer activity. Examination of the PC-3 cells treated with compound 1 using fluorescence microscopy showed that PC-3 cells were killed by apoptosis.Key words: Gallic acid; Bauhinia kockiana; pyrogallol; anticancer; apoptosis

Burnout and work-related stressors in gastroenterology: a protocol for a multinational observational study in the ASEAN region.

BACKGROUND: Clinician burnout is an important occupational hazard that may be exacerbated by the novel COVID-19 pandemic. Within Southeast Asia, burnout in gastroenterology is understudied. The primary objective of this study is to estimate the prevalence of burnout symptoms within gastroenterology, in member states of the Associations of Southeast Asian Nations (ASEAN), during and after the COVID-19 pandemic. The secondary objective is to identify work-related stressors that contribute to burnout in ASEAN gastroenterologists. METHODS AND ANALYSIS: This is an observational study that will use anonymised online surveys to estimate the prevalence of burnout symptoms at two time points: during the COVID-19 pandemic in 2020 and in 2022 (assumed to be after the pandemic). Gastroenterologists from Singapore, Malaysia, Thailand, Indonesia, Philippines and Brunei will be invited to participate in the online survey through their national gastroenterology and endoscopy societies. Burnout will be assessed using the Maslach Burnout Inventory-Human Services Survey tool. Supplementary questions will collect demographic and qualitative data. Associations between demographic characteristics and burnout will be tested by multiple regression. RESULTS: The prevalence of burnout symptoms in gastroenterology during the COVID-19 pandemic, and the baseline prevalence after COVID-19, will be established in the above-mentioned countries. Work-related stressors commonly associated with burnout will be identified, allowing the introduction of preventative measures to reduce burnout in the future. ETHICS AND DISSEMINATION: Ethical approval was granted by the Singhealth Centralised Institutional Review Board (2020/2709). Results will be submitted for publication

Linear Segmented Arc-Shaped Piezoelectric Branch Beam Energy Harvester for Ultra-Low Frequency Vibrations

Data Availability Statement: Data could be provided upon request to the corresponding author.Piezoelectric energy harvesting systems have been drawing the attention of the research community over recent years due to their potential for recharging/replacing batteries embedded in low-power-consuming smart electronic devices and wireless sensor networks. However, conventional linear piezoelectric energy harvesters (PEH) are often not a viable solution in such advanced practices, as they suffer from a narrow operating bandwidth, having a single resonance peak present in the frequency spectrum and very low voltage generation, which limits their ability to function as a standalone energy harvester. Generally, the most common PEH is the conventional cantilever beam harvester (CBH) attached with a piezoelectric patch and a proof mass. This study investigated a novel multimode harvester design named the arc-shaped branch beam harvester (ASBBH), which combined the concepts of the curved beam and branch beam to improve the energy-harvesting capability of PEH in ultra-low-frequency applications, in particular, human motion. The key objectives of the study were to broaden the operating bandwidth and enhance the harvester’s effectiveness in terms of voltage and power generation. The ASBBH was first studied using the finite element method (FEM) to understand the operating bandwidth of the harvester. Then, the ASBBH was experimentally assessed using a mechanical shaker and real-life human motion as excitation sources. It was found that ASBBH achieved six natural frequencies within the ultra-low frequency range (<10 Hz), in comparison with only one natural frequency achieved by CBH within the same frequency range. The proposed design significantly broadened the operating bandwidth, favouring ultra-low-frequency-based human motion applications. In addition, the proposed harvester achieved an average output power of 427 μW at its first resonance frequency under 0.5 g acceleration. The overall results of the study demonstrated that the ASBBH design can achieve a broader operating bandwidth and significantly higher effectiveness, in comparison with CBH.Southern Cross University, Australia

Potassium channel dysfunction in human neuronal models of Angelman syndrome

Disruptions in the ubiquitin protein ligase E3A (UBE3A) gene cause Angelman syndrome (AS). Whereas AS model mice have associated synaptic dysfunction and altered plasticity with abnormal behavior, whether similar or other mechanisms contribute to network hyperactivity and epilepsy susceptibility in AS patients remains unclear. Using human neurons and brain organoids, we demonstrate that UBE3A suppresses neuronal hyperexcitability via ubiquitin-mediated degradation of calcium- and voltage-dependent big potassium (BK) channels. We provide evidence that augmented BK channel activity manifests as increased intrinsic excitability in individual neurons and subsequent network synchronization. BK antagonists normalized neuronal excitability in both human and mouse neurons and ameliorated seizure susceptibility in an AS mouse model. Our findings suggest that BK channelopathy underlies epilepsy in AS and support the use of human cells to model human developmental diseases

Biofilter aquaponic system for nutrients removal from fresh market wastewater

Aquaponics is a significant wastewater treatment system which refers to the combination of conventional aquaculture (raising aquatic organism) with hydroponics (cultivating plants in water) in a symbiotic environment. This system has a high ability in removing nutrients compared to conventional methods because it is a natural and environmentally friendly system (aquaponics). The current chapter aimed to review the possible application of aquaponics system to treat fresh market wastewater with the intention to highlight the mechanism of phytoremediation occurs in aquaponic system. The literature revealed that aquaponic system was able to remove nutrients in terms of nitrogen and phosphorus

The prevalence of burnout, risk factors, and job-related stressors in gastroenterologists: A systematic review.

Funder: Journal of Gastroenterology & Hepatology Foundation (Australia); Id: http://dx.doi.org/10.13039/501100001352Funder: National University of Singapore; Id: http://dx.doi.org/10.13039/501100001352Funder: British Society of GastroenterologyBACKGROUND AND AIMS: Burnout is an important occupational hazard, and the scale of the problem within gastroenterology remains poorly understood. The primary objective of this study was to understand the prevalence of burnout in gastroenterology and ascertain if there was a common prevalence within the field. The secondary objective was to identify factors and job-related stressors that commonly contribute to burnout in gastroenterologists. METHODS: Systematic searches were conducted in PubMed, Scopus, Cochrane, and PsycINFO by two reviewers independently for articles published to 1 September 2020. The primary outcome measure was the reported prevalence of burnout in gastroenterologists. The secondary outcome measures were (i) the prevalence of non-somatic burnout symptoms (emotional exhaustion, depersonalization, and low personal accomplishment) and (ii) the frequency of risk factors and stressors reported in studies. Data were presented, and limited meta-analyses discussed. RESULTS: Data were extracted from 11 studies. 54.5% (6/11) of these studies reported the prevalence of burnout in gastroenterologists; this ranged from 18.3% to 64.4%. Similar to burnout prevalence, burnout symptoms showed geographical variation and were common in gastroenterologists (up to 63.9%). Factors associated with work volume, age, and female gender were the three most frequently reported risk factors for increased levels of stress and burnout in 72.7% (8/11), 54.5% (6/11), and 45.5% (5/11) of studies, respectively. Significant methodological and clinical heterogeneity was observed. CONCLUSIONS: Burnout and its non-somatic symptoms are common in gastroenterologists, but the syndrome is understudied within the field. Further research and good quality data are needed to help address the problem

The impact of the coronavirus disease 2019 pandemic on gastroenterologists in Southeast Asia: A mixed-methods study.

Funder: National University of Singapore; Id: http://dx.doi.org/10.13039/501100001352Funder: University of Cambridge; Id: http://dx.doi.org/10.13039/501100000735Funder: JGH FoundationBACKGROUND AND AIM: The coronavirus disease 2019 pandemic has impacted gastroenterology practices worldwide; however, its protracted effects within Southeast Asia were unknown. The primary aim of the study was to determine the impact of the pandemic on clinical demands including burnout among gastroenterologists within the region. The secondary aim was to identify risk factors for burnout and determine regional stressors. METHODS: This was a mixed-methods study. Gastroenterologists were surveyed electronically between September 1 and December 7, 2020, via gastroenterology and endoscopy societies of Brunei, Indonesia, Malaysia, Philippines, Singapore, and Thailand. Quantitative and qualitative data were collected. The 22-item Maslach Burnout Inventory-Human Services Survey (MBI-HSS) was used to detect burnout. Quantitative data were non-parametric; non-parametric methods were used for statistical comparisons. Logistic regression was used to determine risk factors for burnout. Content analysis method was used to analyze qualitative data. Ethical approval was obtained. RESULTS: A total of 73.0% reported that they were still significantly affected by the pandemic. Of these, 40.5% reported increased workload and 59.5% decreased workload. Statistically significant differences in weekly working hours, endoscopy, and inpatient volumes were present. No differences were observed in outpatient volumes, likely because of telemedicine. Burnout was common; however, 50.1% of gastroenterologists were unaware of or did not have access to mental health support. This, as well as depression, being a trainee, and public sector work, increased burnout risk significantly. CONCLUSION: The effects of the pandemic are multifaceted, and burnout is common among Southeast Asian gastroenterologists. Safeguards for mental health are suboptimal, and improvements are urgently needed

Role of cardiac mitofusins in cardiac conduction following simulated ischemia–reperfusion

Mitochondrial dysfunction induced by acute cardiac ischemia–reperfusion (IR), may increase susceptibility to arrhythmias by perturbing energetics, oxidative stress production and calcium homeostasis. Although changes in mitochondrial morphology are known to impact on mitochondrial function, their role in cardiac arrhythmogenesis is not known. To assess action potential duration (APD) in cardiomyocytes from the Mitofusins-1/2 (Mfn1/Mfn2)-double-knockout (Mfn-DKO) compared to wild-type (WT) mice, optical-electrophysiology was conducted. To measure conduction velocity (CV) in atrial and ventricular tissue from the Mfn-DKO and WT mice, at both baseline and following simulated acute IR, multi-electrode array (MEA) was employed. Intracellular localization of connexin-43 (Cx43) at baseline was evaluated by immunohistochemistry, while Cx-43 phosphorylation was assessed by Western-blotting. Mfn-DKO cardiomyocytes demonstrated an increased APD. At baseline, CV was significantly lower in the left ventricle of the Mfn-DKO mice. CV decreased with simulated-ischemia and returned to baseline levels during simulated-reperfusion in WT but not in atria of Mfn-DKO mice. Mfn-DKO hearts displayed increased Cx43 lateralization, although phosphorylation of Cx43 at Ser-368 did not differ. In summary, Mfn-DKO mice have increased APD and reduced CV at baseline and impaired alterations in CV following cardiac IR. These findings were associated with increased Cx43 lateralization, suggesting that the mitofusins may impact on post-MI cardiac-arrhythmogenesis