Molecular dynamics simulation of oleyl oleate swollen micelles system

Problems with transdermal drug delivery were directly associated with the skin barrier which is the lipid bilayer at the stratum corneum. Chemical penetration enhancers such as swollen micelles that formed from the solubilisation of the surfactants in the nano-emulsion system could provide an effective solution. However, the structural properties of swollen micelles from nano-emulsions of palm-oil esters, whose behaviour is related to colloidal systems, have not been studied in great detail. In this paper, we report on the use of molecular dynamics (MD) simulations to investigate the structural properties of swollen micelles of oleyl oleate (OE). Five series of 10 ns MD simulations were performed at different micelle compositions to determine the structural evolution of OE/Span20 (S20) swollen micelles. We also carried out four MD simulations on the structure of S20, OE/S20, Tween80 (T80) and OE/T80 micelles to study the effect of different surfactants and the addition of OE into the systems. The shapes of the swollen micelles were observed to vary by the difference in the micelle composition, the surfactants used and the addition of OE. The results were correlated with published theory, and consistent with experimental results on the phase behaviour of the nano-emulsion system

Characteristics and Preliminary Study of Ceramic Concretes

One of the most adaptable and frequently used building materials in the world is concrete. It is flexible in terms of size and shape, sturdy, long-lasting, low-maintenance, fireproof, and easy to use. However, further research is needed to increase the durability and sustainability of this material since concrete technology is still in developing industry. Therefore, it's crucial to comprehend how microstructure and characteristics interact in terms of how they affect concrete's strength, dimensional stability, and durability. The findings of this research are crucial in identifying the properties and characteristics of the ceramic concrete used for bridge construction or others. Advanced research to ascertain the hardness and physical qualities and features of ceramic concrete material is required. Thus, it will help to produce a reliable data for engineer to refer for their future works or project. To ascertain its hardness and physical characteristics, research has been conducted on ceramic concrete for several types of grades. In the current study, the ceramic concrete was tested through the physical and Vickers-hardness tests. The X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) on samples were performed to observe the phases and morphology of the ceramic concrete, respectively. For results of physical testing, the density and water absorption correlate to each other by the denser of the sample, the lower of water absorption and the porosity level of the ceramic concrete. Based on the Vickers micro hardness test, it can be seen that longer curing days affected the hardness, where the concretes of grade 30 and 40 at 28 curing days had better hardness value. Next, Scanning Electron Microscopy (SEM) on samples shown almost same microstructure, while the dominant phase of all ceramic concrete grades was SiO2 by the XRD analysis. In summary, better properties of ceramic concretes were indicated at 28 curing days for both grades of ceramic concretes

In-silico identification of potential Protein Arginine Deiminase IV (PAD4) inhibitors

Protein Arginine Deiminase IV (PAD4) is a promising target for treating rheumatoid arthritis. Here, an in-silico screening was performed using PAD4 crystal structure against National Cancer Institute Diversity Set III compounds. Results obtained from the docking studies showed that the compounds have high affinity towards the protein. Visual inspections of the top compounds indicated that they preferred to bind at the front door of the catalytic pocket instead of the back door. The current results from this screening could provide a basis for the development of new PAD4 inhibitors

Protein-solvent interaction and simulation studies of solvent stable and thermostable lipase from Bacillus strain 42 in water-solvent mixtures

A purified solvent stable and thermostable recombinant lipase, Lip 42, isolated from Bacillus sp. strain 42 was previously shown to be stable in polar organic solvents such as dimethyl sulfoxide (DMSO) and methanol. Stabilities in different solvent compositions were studied based on 40˚C pre-incubation in solvent and the purified lipase was shown to retain at least 100% residual activity in up to 45% v/v DMSO and 45% v/v methanol. In 60% v/v DMSO, 68% of residual activity was retained, however, this dramatically reduced to 6.5 % at 65% v/v DMSO. Activity enhancement was recorded at lower solvent composition (less than 45% v/v solvent), whereby, at 30% v/v DMSO, enhancement was recorded to be as much as 35%. Enhancement tends to increase as temperature increases. Based on these solvent stability margin, molecular dynamic simulations were then carried out in the presence of water, 60% v/v DMSO + 40% v/v water and 100% v/v DMSO, by using a structure model predicted from a highly homologous (97%) lipase (PDB:1JI3). Results showed that the Lip 42 structure was retained and the flexibility of polypeptide backbone decreased or increased depending on the location of loop regions. Flexibility changes in the helixloop-helix-motif covering catalytic triad were found to be associated with a hydrophobic cluster region. The presence of 60% v/v DMSO resulted in the disorganization of the cluster, accompanied with non-native H-bonds formations. However, the cluster still presents in 100% v/v DMSO and resembles to that of water simulation. Mutant form of lip 42 V174S contains residue substitution near the cluster and within helix-loop helix motif. At 50˚C pre-incubation, the mutant lost as much of high temperature enhancement commonly observed in low DMSO composition. This indicates the potential role of hydrophobic residues in helix-loophelix motif and the cluster in interfacial activation

Molecular dynamics simulation of palm-based nano-emulsion system

Nano-emulsions of oleyl oleate posses the potential to act as penetration enhancers in pharmaceutical applications. However, information on the phase behavior of oleyl oleate nano-emulsions which obtained through laboratory experiments was insufficient to describe the structural mechanism of the self-assembled system. In this research, the structural and dynamical properties of the palm-based nano-emulsions to act as penetration enhancer were studied by computer simulations. The structural and dynamical information of the nano-emulsions were obtained using molecular dynamics (MD) simulation method. The nano-emulsions system comprised of oleyl oleate (oil) with Span20 and Tween80 as the non-ionic surfactants was simulated in the presence of water molecules (oil-in-water system). The effect of lipid composition in the nano-emulsions system was determined by 5 series of MD simulations up to 2.5 ns. The simulation results showed that different shapes of the nano-emulsions were formed as the composition of oil was increased. The critical micelle concentration was found at 20% – 30% of lipid composition while the higher concentrations lead to the formation of lamellar system. Larger system with random initial configuration was used to simulate the self-assembly characteristics of the nano-emulsions system. The aggregation and disaggregation of the oil and surfactant molecules were observed throughout the simulation

Metabarcoding of Parasitic Wasp, Dolichogenidea metesae(Nixon)(Hymenoptera: Braconidae) That Parasitizing Bagworm, Metisa plana Walker (Lepidoptera: Psychidae)

Microbiome studies of the parasitoid wasp, Dolichogenidea metesae (Nixon) (Hymenoptera, Braconidae) are important because D. metesae has potential as a biological control agent to suppress the pest, Metisa plana Walker (Lepidoptera, Psychidae). Three field populations of parasitic wasps with different Integrated Pest Management (IPM) practices to control M. plana collected from Perak state (Tapah) and Johor state (Yong Peng and Batu Pahat districts) in Peninsular Malaysia were studied. Bacterial community composition and structure were analysed using α and β diversity metrics. Proteobacteria (83.31%) and Bacteroidetes (6.80%) were the most dominant phyla, whereas unknown family from order Rhizobiales was the most abundant family found in all populations followed by Pseudomonadaceae. Family Micrococcaceae was absent in Tapah. Rhizobiales gen. sp. and Pseudomonas sp. were abundant in all populations. Pearson’s correlation analysis showed the strongest correlation between individuals of Batu Pahat and Yong Peng (r = 0.89827, p < 0.05), followed by Tapah and Yong Peng with r = 0.75358, p < 0.05 and Batu Pahat and Tapah (r = 0.69552, p < 0.05). We hypothesise that low diversity and richness in Tapah might be due to direct and indirect effect of insecticides application. This preliminary data was the first study to do inventory of the microbiomes in the gut of the D. metesae

Assessing methodological variability in gut microbiome studies: lessons from Southeast Asian for effective conservation strategies.

Gut microbiome studies have gained significant attention in recent years due to their potential in unveiling the role of microbial communities in animals’ health and ecological processes. However, the lack of standardized protocols in sample handling and processing across studies introduces variability, impeding the comparability of findings. This study addresses this issue by examining methodological variations in gut microbiome research on wildlife and domesticated animals in Southeast Asia. A comprehensive search of 91 relevant studies on the SCOPUS database yielded 54 suitable publications for review, encompassing diverse taxa such as invertebrates (20), fishes (7), reptiles (3), birds (5), and mammals (19). Notably, various methodological approaches were employed to characterize microbial communities, including the source of isolation, various culture-based approaches, sequencing methods, and the targeted markers. Based on the information provided in this study, future studies should strive to develop guidelines and best practices specific to gut microbiome studies. This would enhance comparability and facilitate the integration of findings. Such efforts will also advance our understanding of the microbial diversity associated with wildlife, and its potential implications for their health and conservation

National guidelines for the diagnosis and treatment of hilar cholangiocarcinoma

©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.Peer reviewe

Isoprene hotspots at the Western Coast of Antarctic Peninsula during MASEC′16

Isoprene (C5H8) plays an important role in the formation of surface ozone (O3) and the secondary organic aerosol (SOA) which contributed to the climate change. This study aims to determine hourly distribution of tropospheric isoprene over the Western Coast of Antarctic Peninsula (WCAP) during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC′16). In-situ measurements of isoprene were taken using a custom-built gas chromatography with photoionization detector, known as iDirac. Biological parameters such as chlorophyll a (chl-a) and particulate organic carbon (POC) were compared to the in-situ isoprene measurements. Significant positive correlation was observed between isoprene and POC concentrations (r2 = 0.67, p < 0.001), but not between isoprene and chl-a. The hotspots of isoprene over maritime Antarctic were then were investigated using NAME dispersion model reanalysis. Measurements showed that isoprene mixing ratio were the highest over region of King George Island, Deception Island and Booth Island with values of ∼5.0, ∼0.9 and ∼5.2 ppb, respectively. Backward trajectory analysis showed that air masses may have lifted the isoprene emitted by marine algae. We believe our findings provide valuable data set of isoprene estimation over the under sampled WCAP