Comparative study of the antidiabetic potential of Paederia foetida twig extracts and compounds from two different locations in Malaysia

Context: Paederia foetida L. (Rubiaceae) is an edible plant distributed in Asian countries including Malaysia. Fresh leaves have been traditionally used as a remedy for indigestion and diarrhea. Several phytochemical studies of the leaves have been documented, but there are few reports on twigs. Objective: This study investigates the enzyme inhibition of P. foetida twig extracts and compound isolated from them. In addition, in silico molecular docking of scopoletin was investigated. Materials and methods: Plants were obtained from two locations in Malaysia, Johor (PFJ) and Pahang (PFP). Hexane, chloroform and methanol extracts along with isolated compound (scopoletin) were evaluated for their enzyme inhibition activities (10,000-0.000016 µg/mL). The separation and identification of bio-active compounds were carried out using column chromatography and spectroscopic techniques, respectively. In silico molecular docking of scopoletin with receptors (α-amylase and α-glucosidase) was carried out using AutoDock 4.2. Results: The IC50 values of α-amylase and α-glucosidase inhibition activity of PFJ chloroform extract were 9.60 and 245.6 µg/mL, respectively. PFP chloroform extract exhibited α-amylase and α-glucosidase inhibition activity (IC50 = 14.83 and 257.2 µg/mL, respectively). The α-amylase and α-glucosidase inhibitory activity of scopoletin from both locations had IC50 values of 0.052 and 0.057 µM, respectively. Discussion and conclusions: Separation of PFJ chloroform extract afforded scopoletin (1), stigmasterol (2) and γ-sitosterol (3) and the PFP chloroform extract yielded (1), (2), (3) and ergost-5-en-3-ol (4). Scopoletin was isolated from this species for the first time. In silico calculations gave a binding energy between scopoletin and α-amylase of -6.03 kcal/mol

2020 roadmap on two-dimensional materials for energy storage and conversion

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

The LRRK2 Arg1628Pro variant is a risk factor for Parkinson's disease in the Chinese population

The c.G4883C variant in the leucine-rich repeat kinase 2 (LRRK2) gene (protein effect: Arg1628Pro) has been recently proposed as a second risk factor for sporadic Parkinson's disease in the Han Chinese population (after the Gly2385Arg variant). In this paper, we analyze the Arg1628Pro variant and the associated haplotype in a large sample of 1,337 Han subjects (834 patients and 543 controls) ascertained from a single referral center in Taiwan. In our sample, the Arg1628Pro allele was more frequent among patients (3.8%) than among controls (1.8%; p = 0.004, OR 2.13, 95% CI 1.29-3.52). Sixty heterozygous and two homozygous carriers of the Arg1628Pro variant were identified among the patients, of which only one was also a carrier of the LRRK2 Gly2385Arg variant. We also show that carriers of the Arg1628Pro variant share a common, extended haplotype, suggesting a founder effect. Parkinson's disease onset age was similar in patients who carried the Arg1628Pro variant and in those who did not carry it. Our data support the contention that the Arg1628Pro variant is a second risk factor for Parkinson's disease in the Han Chinese population. Adding the estimated effects of Arg1628Pro (population attributable risk [PAR] ∼4%) and Gly2385Arg variants (PAR ∼6%) yields a total PAR of ∼10%

LEAF LITTER DECOMPOSITION IN NEE SOON SWAMP FOREST, SINGAPORE

Bachelor'sBachelor of Environmental Studies (Honours

BREEDING MONSTERS: RESISTANCE WITHIN SINGAPORE'S HETEROTOPIC PUBLIC HOUSING SYSTEM

Master'sMASTER OF ARCHITECTURE (M.ARCH

Advanced materials characterisation for sensor materials

This study is mainly focused on material characterisation for soft robotic sensors which would be launched in the market for commercial usage in the future. The materials which would be used for this project are piezoelectric materials, mainly Zinc Oxide (ZnO) and Molybdenum Sulfide (MoS2) and techniques required for this project includes SEM, XRD, XPS, AFM, PFM and ALD. The objective is to find out the relationship between the morphology, composition, and phase constitution with the piezo properties for the application of robotic sensors and aims to come up with sensors that can bend and stretch for different applications and at the same time, able to detect physical properties of objects, despite its minute size with high sensitivity and spatial resolution. The robotic grip sensors which we fabricate aims to find out the following properties of one’s hair condition such as the suppleness, smoothness, hydrophilicity and stickiness.Bachelor of Engineering (Materials Engineering

Plant ash augmented enzymatic hydrolysis approach for ultrafast conversion of food waste to biofertilizers

This study developed an augmentation approach of the enzymatic hydrolysis of food waste using plant ash with the fungal mash produced in situ from food waste as well. The mixture of food waste, fungal mash and different concentrations of plant ash were prepared for hydrolysis. After the 8-h hydrolysis, the hydrolysate solid and liquid were separated. The results show that the NPK contents in both produced hydrolysate solid and liquid can meet the requirements for biofertilizer. To find out the suitable concentration of plant ash that provides the most favourable results, a field planting trial was carried out using a commonly consumed leafy vegetable, xiao bai cai (Brassica rapa), by the addition of food waste-derived biofertilizers in place of commercial biofertilizers. The results of the field planting trial show that the biofertilizers produced with augmentation of 15% and 30% plant ash (w/w food waste) provided results that are comparable to the growth of xiao bai cai from commercial biofertilizers. As such, it is suggested that hydrolysis of food waste with 15% or 30% plant ash (w/w food waste) and the fungal mash produced in situ from food waste could produce biofertilizers which favour the growth of plants. Hence, this may be another option in food waste management to achieve the ultimate target of zero waste discharge.Bachelor of Engineering (Environmental Engineering

New Insights on the Fast Response of Poly(Ionic Liquid)s to Humidity: The Effect of Free-Ion Concentration

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-BF4) 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

Withdrawn: Optimal cap setting and pricing in supply chains under vertical-horizontal cooperation and cap-and-trade regulation

This article has been withdrawn at the request of the authors, who did not approve the publication in a supplementary issue. The Publisher apologizes for the inconvenience this is causing