Studies relating to trends of vegetation, snowfall and temperature in the north-western Himalayan region of India are generally focused on specific areas. Therefore, a proper understanding of regional changes in climate parameters over large time periods is generally absent, which increases the complexity of making appropriate conclusions related to climate change-induced effects in the Himalayan region. This study provides a broad overview of changes in patterns of vegetation, snow covers and temperature in Uttarakhand state of India through bulk processing of remotely sensed Moderate Resolution Imaging Spectroradiometer (MODIS) data, meteorological records and simulated global climate data. Additionally, regression using machine learning algorithms such as Support Vectors and Long Short-term Memory (LSTM) network is carried out to check the possibility of predicting these environmental variables. Results from 17 years of data show an increasing trend of snow-covered areas during pre-monsoon and decreasing vegetation covers during monsoon since 2001. Solar radiation and cloud cover largely control the lapse rate variations. Mean MODIS-derived land surface temperature (LST) observations are in close agreement with global climate data. Future studies focused on climate trends and environmental parameters in Uttarakhand could fairly rely upon the remotely sensed measurements and simulated climate data for the region.
Here, we report the extracellular biosynthesis of silver nanoparticles (AgNPs) and determination of their antibacterial and anticancer properties. We also explore the efficacy of bioAgNPs incorporated in cellulose nanocrystals (CNCs) and alginate (Alg) for the formation of an antibacterial hydrogel film. Streptomyces sp. PBD-311B was used for the biosynthesis of AgNPs. The synthesized bioAgNPs were characterized using UV-Vis spectroscopy, TEM, XRD, and FTIR analysis. Then, the bioAgNPs' antibacterial and anticancer properties were determined using TEMA and cytotoxicity analysis. To form the antibacterial hydrogel film, bioAgNPs were mixed with a CNC and Alg solution and further characterized using FTIR analysis and a disc diffusion test. The average size of the synthesized bioAgNPs is around 69 ± 2 nm with a spherical shape. XRD analysis confirmed the formation of silver nanocrystals. FTIR analysis showed the presence of protein capping at the bioAgNP surface and could be attributed to the extracellular protein binding to bioAgNPs. The MIC value of bioAgNPs against P. aeruginosa USM-AR2 and MRSA was 6.25 mg/mL and 3.13 mg/mL, respectively. In addition, the bioAgNPs displayed cytotoxicity effects against cancer cells (DBTRG-0.5MG and MCF-7) and showed minimal effects against normal cells (SVG-p12 and MCF-10A), conferring selective toxicity. Interestingly, the bioAgNPs still exhibited inhibition activity when incorporated into CNC/Alg, which implies that the hydrogel film has antibacterial properties. It was also found that bioAgNP-CNC/Alg displayed a minimal or slow release of bioAgNPs owing to the intermolecular interaction and the hydrogel's properties. Overall, bioAgNP-CNC/Alg is a promising antibacterial hydrogel film that showed inhibition against the pathogenic bacteria P. aeruginosa and MRSA and its application can be further evaluated for the inhibition of cancer cells. It showed benefits for surgical resection of a tumor to avoid post-operative wound infection and tumor recurrence at the surgical site.
Graphene as a material for optoelectronic design applications has been significantly restricted owing to zero bandgap and non-compatible handling procedures compared with regular microelectronic ones. In this work, nitrogen-doped reduced graphene oxide (N-rGO) with tunable optical bandgap and enhanced electrical conductivity was synthesized via a microwave-assisted hydrothermal method. The properties of the synthesized N-rGO were determined using XPS, FTIR and Raman spectroscopy, UV/vis, as well as FESEM techniques. The UV/vis spectroscopic analysis confirmed the narrowness of the optical bandgap from 3.4 to 3.1, 2.5, and 2.2 eV in N-rGO samples, where N-rGO samples were synthesized with a nitrogen doping concentration of 2.80, 4.53, and 5.51 at.%. Besides, an enhanced n-type electrical conductivity in N-rGO was observed in Hall effect measurement. The observed tunable optoelectrical characteristics of N-rGO make it a suitable material for developing future optoelectronic devices at the nanoscale.
Chrysin, a herbal bioactive molecule, exerts a plethora of pharmacological effects, including anti-oxidant, anti-inflammatory, neuroprotective, and anti-cancer. A growing body of evidence has highlighted the emerging role of chrysin in a variety of neurological disorders, including Alzheimer's and Parkinson's disease, epilepsy, multiple sclerosis, ischemic stroke, traumatic brain injury, and brain tumors. Based on the results of recent pre-clinical studies and evidence from studies in humans, this review is focused on the molecular mechanisms underlying the neuroprotective effects of chrysin in different neurological diseases. In addition, the potential challenges, and opportunities of chrysin's inclusion in the neurotherapeutics repertoire are critically discussed.
Haematococcus pluvialis, a green microalga, appears to be a rich source of valuable bioactive compounds, such as astaxanthin, carotenoids, proteins, lutein, and fatty acids (FAs). Astaxanthin has a variety of health benefits and is used in the nutraceutical and pharmaceutical industries. Astaxanthin, for example, preserves the redox state and functional integrity of mitochondria and shows advantages despite a low dietary intake. Because of its antioxidant capacity, astaxanthin has recently piqued the interest of researchers due to its potential pharmacological effects, which include anti-diabetic, anti-inflammatory, and antioxidant activities, as well as neuro-, cardiovascular-, ocular, and skin-protective properties. Astaxanthin is a popular nutritional ingredient and a significant component in animal and aquaculture feed. Extensive studies over the last two decades have established the mechanism by which persistent oxidative stress leads to chronic inflammation, which then mediates the majority of serious diseases. This mini-review provides an overview of contemporary research that makes use of the astaxanthin pigment. This mini-review provides insight into the potential of H. pluvialis as a potent antioxidant in the industry, as well as the broad range of applications for astaxanthin molecules as a potent antioxidant in the industrial sector.
Surface plasmon (SP)-induced spectral hole burning (SHB) at the silver-dielectric interface is investigated theoretically. We notice a typical lamb dip at a selective frequency, which abruptly reduces the absorption spectrum of the surface plasmons polaritons (SPP). Introducing the spontaneous generated coherence (SGC) in the atomic medium, the slope of dispersion becomes normal. Additionally, slow SPP propagation is also noticed at the interface. The spectral hole burning dip is enhanced with the SGC effect and can be modified and controlled with the frequency and intensity of the driving fields. The SPP propagation length at the hole-burning region is greatly enhanced under the effect of SGC. A propagation length of the order of 600 µm is achieved for the modes, which is a remarkable result. The enhancement of plasmon hole burning under SGC will find significant applications in sensing technology, optical communication, optical tweezers and nano-photonics.
Electrochemical devices, especially energy storage, have been around for many decades. Liquid electrolytes (LEs), which are known for their volatility and flammability, are mostly used in the fabrication of the devices. Dye-sensitized solar cells (DSSCs) and quantum dot sensitized solar cells (QDSSCs) are also using electrochemical reaction to operate. Following the demand for green and safer energy sources to replace fossil energy, this has raised the research interest in solid-state electrochemical devices. Solid polymer electrolytes (SPEs) are among the candidates to replace the LEs. Hence, understanding the mechanism of ions' transport in SPEs is crucial to achieve similar, if not better, performance to that of LEs. In this paper, the development of SPE from basic construction to electrolyte optimization, which includes polymer blending and adding various types of additives, such as plasticizers and fillers, is discussed.
Chicken is known to be the most common meat type involved in food mislabeling and adulteration. Establishing a method to authenticate chicken content precisely and identifying chicken breeds as declared in processed food is crucial for protecting consumers' rights. Categorizing the authentication method into their respective omics disciplines, such as genomics, transcriptomics, proteomics, lipidomics, metabolomics, and glycomics, and the implementation of bioinformatics or chemometrics in data analysis can assist the researcher in improving the currently available techniques. Designing a vast range of instruments and analytical methods at the molecular level is vital for overcoming the technical drawback in discriminating chicken from other species and even within its breed. This review aims to provide insight and highlight previous and current approaches suitable for countering different circumstances in chicken authentication.
Enterovirus 71 (EV-A71) is one of the predominant etiological agents of hand, foot and mouth disease (HMFD), which can cause severe central nervous system infections in young children. There is no clinically approved vaccine or antiviral agent against HFMD. The SP40 peptide, derived from the VP1 capsid of EV-A71, was reported to be a promising antiviral peptide that targeted the host receptor(s) involved in viral attachment or entry. So far, the mechanism of action of SP40 peptide is unknown. In this study, interactions between ten reported cell receptors of EV-A71 and the antiviral SP40 peptide were evaluated through molecular docking simulations, followed by in vitro receptor blocking with specific antibodies. The preferable binding region of each receptor to SP40 was predicted by global docking using HPEPDOCK and the cell receptor-SP40 peptide complexes were refined using FlexPepDock. Local molecular docking using GOLD (Genetic Optimization for Ligand Docking) showed that the SP40 peptide had the highest binding score to nucleolin followed by annexin A2, SCARB2 and human tryptophanyl-tRNA synthetase. The average GoldScore for 5 top-scoring models of human cyclophilin, fibronectin, human galectin, DC-SIGN and vimentin were almost similar. Analysis of the nucleolin-SP40 peptide complex showed that SP40 peptide binds to the RNA binding domains (RBDs) of nucleolin. Furthermore, receptor blocking by specific monoclonal antibody was performed for seven cell receptors of EV-A71 and the results showed that the blocking of nucleolin by anti-nucleolin alone conferred a 93% reduction in viral infectivity. Maximum viral inhibition (99.5%) occurred when SCARB2 was concurrently blocked with anti-SCARB2 and the SP40 peptide. This is the first report to reveal the mechanism of action of SP40 peptide in silico through molecular docking analysis. This study provides information on the possible binding site of SP40 peptide to EV-A71 cellular receptors. Such information could be useful to further validate the interaction of the SP40 peptide with nucleolin by site-directed mutagenesis of the nucleolin binding site.
Gas chromatography with flame ionization detection (GC-FID) has often been used to quantify fatty acids in fish. This study validated the common method for determining omega-3 fatty acids (DHA and EPA) in the raw and cooked warm-water fish, selayang, using GC-FID for subsequent evaluation on EPA and DHA retention using the Weibull model. The EPA and DHA were separated using a high-polarity capillary GC HP-88 column (60 m length, 0.25 mm ID, 0.2 μm DF) with a total run time of 45.87 min. The method was validated in linearity, precision, accuracy, specificity and sensitivity based on ICH requirements. In addition, it was found that the method had a high recovery rate (>95%) and good precision (RSD ≤ 2%) with overall RSDs ranging below 0.001% for both omega-3 PUFA. In conclusion, this method identified and quantified fatty acids and omega-3 accurately and precisely and can be used effectively for routine FAME analysis in fish samples.
This study's objective was to examine L-arginine (L-arg) supplementation's effect on mono-species biofilm (Streptococcus mutans/Streptococcus sanguinis) growth and underlying enamel substrates. The experimental groups were 1%, 2%, and 4% arg, and 0.9% NaCl was used as the vehicle control. Sterilised enamel blocks were subjected to 7-day treatment with test solutions and S. mutans/S. sanguinis inoculum in BHI. Post-treatment, the treated biofilms stained for live/dead bacterial cells were analysed using confocal microscopy. The enamel specimens were analysed using X-ray diffraction crystallography (XRD), Raman spectroscopy (RS), and transmission electron microscopy (TEM). The molecular interactions between arg and MMP-2/MMP-9 were determined by computational molecular docking and MMP assays. With increasing arg concentrations, bacterial survival significantly decreased (p < 0.05). The XRD peak intensity with 1%/2% arg was significantly higher than with 4% arg and the control (p < 0.05). The bands associated with the mineral phase by RS were significantly accentuated in the 1%/2% arg specimens compared to in other groups (p < 0.05). The TEM analysis revealed that 4% arg exhibited an ill-defined shape of enamel crystals. Docking of arg molecules to MMPs appears feasible, with arg inhibiting MMP-2/MMP-9 (p < 0.05). L-arginine supplementation has an antimicrobial effect on mono-species biofilm. L-arginine treatment at lower (1%/2%) concentrations exhibits enamel hydroxyapatite stability, while the molecule has the potential to inhibit MMP-2/MMP-9.
Plasmodium lactate dehydrogenase (pLH) is one of the enzymes in glycolysis with potential target for chemotherapy. This study aimed to clone, overexpress and characterize soluble recombinant lactate dehydrogenase from Plasmodium knowlesi in a bacterial system. Synthetic P. knowlesi lactate dehydrogenase (Pk-LDH) gene was cloned into pET21a expression vector, transformed into Escherichia coli strain BL21 (DE3) expression system and then incubated for 18 h, 20 °C with the presence of 0.5 mM isopropyl β-d-thiogalactoside in Terrific broth supplemented with Magnesium sulfate, followed by protein purifications using Immobilized Metal Ion Affinity Chromatography and size exclusion chromatography (SEC). Enzymatic assay was conducted to determine the activity of the enzyme. SDS-PAGE analysis revealed that protein of 34 kDa size was present in the soluble fraction. In SEC, a single peak corresponding to the size of Pk-LDH protein was observed, indicating that the protein has been successfully purified. From MALDI-TOF analysis findings, a peptide score of 282 was established, which is significant for lactate dehydrogenase from P. knowlesi revealed via MASCOT analysis. Secondary structure analysis of CD spectra indicated 79.4% α helix and 1.37% β strand structure. Specific activity of recombinant Pk-LDH was found to be 475.6 U/mg, confirming the presence of active protein. Soluble Pk-LDH that is biologically active was produced, which can be used further in other malaria studies.
Traditional drug development is a slow and costly process that leads to the production of new drugs. Virtual screening (VS) is a computational procedure that measures the similarity of molecules as one of its primary tasks. Many techniques for capturing the biological similarity between a test compound and a known target ligand have been established in ligand-based virtual screens (LBVSs). However, despite the good performances of the above methods compared to their predecessors, especially when dealing with molecules that have structurally homogenous active elements, they are not satisfied when dealing with molecules that are structurally heterogeneous. The main aim of this study is to improve the performance of similarity searching, especially with molecules that are structurally heterogeneous. The Siamese network will be used due to its capability to deal with complicated data samples in many fields. The Siamese multi-layer perceptron architecture will be enhanced by using two similarity distance layers with one fused layer, then multiple layers will be added after the fusion layer, and then the nodes of the model that contribute less or nothing during inference according to their signal-to-noise ratio values will be pruned. Several benchmark datasets will be used, which are: the MDL Drug Data Report (MDDR-DS1, MDDR-DS2, and MDDR-DS3), the Maximum Unbiased Validation (MUV), and the Directory of Useful Decoys (DUD). The results show the outperformance of the proposed method on standard Tanimoto coefficient (TAN) and other methods. Additionally, it is possible to reduce the number of nodes in the Siamese multilayer perceptron model while still keeping the effectiveness of recall on the same level.
MeSH terms: Algorithms*; Drug Evaluation, Preclinical
The normal function of the airway epithelium is vital for the host's well-being. Conditions that might compromise the structure and functionality of the airway epithelium include congenital tracheal anomalies, infection, trauma and post-intubation injuries. Recently, the onset of COVID-19 and its complications in managing respiratory failure further intensified the need for tracheal tissue replacement. Thus far, plenty of naturally derived, synthetic or allogeneic materials have been studied for their applicability in tracheal tissue replacement. However, a reliable tracheal replacement material is missing. Therefore, this study used a tissue engineering approach for constructing tracheal tissue. Human respiratory epithelial cells (RECs) were isolated from nasal turbinate, and the cells were incorporated into a calcium chloride-polymerized human blood plasma to form a human tissue respiratory epithelial construct (HTREC). The quality of HTREC in vitro, focusing on the cellular proliferation, differentiation and distribution of the RECs, was examined using histological, gene expression and immunocytochemical analysis. Histological analysis showed a homogenous distribution of RECs within the HTREC, with increased proliferation of the residing RECs within 4 days of investigation. Gene expression analysis revealed a significant increase (p < 0.05) in gene expression level of proliferative and respiratory epithelial-specific markers Ki67 and MUC5B, respectively, within 4 days of investigation. Immunohistochemical analysis also confirmed the expression of Ki67 and MUC5AC markers in residing RECs within the HTREC. The findings show that calcium chloride-polymerized human blood plasma is a suitable material, which supports viability, proliferation and mucin secreting phenotype of RECs, and this suggests that HTREC can be a potential candidate for respiratory epithelial tissue reconstruction.
Several significant advancements in the field of bone regenerative medicine have been made in recent years. However, therapeutic options, such as bone grafts, have several drawbacks. There is a need to develop an adequate bone substitute. As a result, significant bone defects/injuries pose a severe challenge for orthopaedic and reconstructive bone tissue. We synthesized polymeric composite material from arabinoxylan (ARX), β-glucan (BG), nano-hydroxyapatite (nHAp), graphene oxide (GO), acrylic acid (AAc) through free radical polymerization and porous scaffold fabricated using the freeze-drying technique. These fabricated porous scaffolds were then coated with chitosan solution to enhance their biological activities. The complex structure of BG, nHAp, GO was studied through various characterization and biological assays. The structural, morphological, wetting and mechanical analyses were determined using FT-IR, XRD, XPS, SEM/EXD, water contact angle and UTM. The swelling (aqueous and PBS media) and degradation (PBS media) observed their behavior in contact with body fluid. The biological activities were conducted against mouse pre-osteoblast cell lines. The result found that BGH3 has desirable morphological, structural with optimum swelling, degradation, and mechanical behavior. It was also found to be cytocompatible against MC3T3-E1 cell lines. The obtained results confirmed that the fabricated polymeric scaffolds would be a potential bone substitute to regenerate defective bone with different loading bearing applications for bone tissue engineering.
The solution cast process is used to set up chitosan: dextran-based plasticized solid polymer electrolyte with high specific capacitance (228.62 F/g) at the 1st cycle. Fourier-transform infrared spectroscopy (FTIR) pattern revealed the interaction between polymers and electrolyte components. At ambient temperature, the highest conductive plasticized system (CDLG-3) achieves a maximum conductivity of 4.16 × 10-4 S cm-1. Using both FTIR and electrical impedance spectroscopy (EIS) methods, the mobility, number density, and diffusion coefficient of ions are measured, and they are found to rise as the amount of glycerol increases. Ions are the primary charge carriers, according to transference number measurement (TNM). According to linear sweep voltammetry (LSV), the CDLG-3 system's electrochemical stability window is 2.2 V. In the preparation of electrical double layer capacitor devices, the CDLG-3 system was used. There are no Faradaic peaks on the cyclic voltammetry (CV) curve, which is virtually rectangular. Beyond the 20th cycle, the power density, energy density, and specific capacitance values from the galvanostatic charge-discharge are practically constant at 480 W/Kg, 8 Wh/Kg, and 60 F g-1, for 180 cycles.
This research was performed to evaluate the physical, mechanical, and morphological properties of treated sugar palm fiber (SPF)/glass fiber (GF) reinforced poly(lactic acid) (PLA) hybrid composites. Morphological investigations of tensile and flexural fractured samples of composites were conducted with the help of scanning electron microscopy (SEM). Alkaline and benzoyl chloride (BC) treatments of SPFs were performed. A constant weight fraction of 30% total fiber loading and 70% poly(lactic acid) were considered. The composites were initially prepared by a Brabender Plastograph, followed by a hot-pressing machine. The results reported that the best tensile and flexural strengths of 26.3 MPa and 27.3 MPa were recorded after alkaline treatment of SPF, while the highest values of tensile and flexural moduli of 607 MPa and 1847 MPa were recorded after BC treatment of SPF for SPF/GF/PLA hybrid composites. The novel SPF/GF/PLA hybrid composites could be suitable for fabricating automotive components.
Biocomposite materials create a huge opportunity for a healthy and safe environment by replacing artificial plastic and materials with natural ingredients in a variety of applications. Furniture, construction materials, insulation, and packaging, as well as medical devices, can all benefit from biocomposite materials. Wheat is one of the world's most widely cultivated crops. Due to its mechanical and physical properties, wheat starch, gluten, and fiber are vital in the biopolymer industry. Glycerol as a plasticizer considerably increased the elongation and water vapor permeability of wheat films. Wheat fiber developed mechanical and thermal properties as a result of various matrices; wheat gluten is water insoluble, elastic, non-toxic, and biodegradable, making it useful in biocomposite materials. This study looked at the feasibility of using wheat plant components such as wheat, gluten, and fiber in the biocomposite material industry.
As a light structure, composite sandwich panels are distinguished by their significant bending stiffness that is rapidly used in the manufacture of aircraft bodies. This study focuses on the mechanical behaviour of through-thickness polymer, pin-reinforced foam core sandwich panels subjected to indentation and low impact loading. Experimental and computational approaches are used to study the global and internal behaviour of the sandwich panel. The samples for experimental testing were made from glass/polyester laminates as the face sheets and polyurethane foam as the foam core. To further reinforce the samples against bending, different sizes of polymeric pins were implemented on the sandwich panels. The sandwich panel was fabricated using the vacuum infusion process. Using the experimental data, a finite element model of the sample was generated in LS-DYNA software, and the effect of pin size and loading rate were examined. Results of the simulation were validated through a proper prediction compared to the test data. The results of the study show that using polymeric pins, the flexural strength of the panel significantly increased under impact loading. In addition, the impact resistance of the pin-reinforced foam core panel increased up to 20%. Moreover, the size of pins has a significant influence on the flexural behaviour while the sample was under a moderate strain rate. To design an optimum pin-reinforced sandwich panel a "design of experiment model" was generated to predict energy absorption and the maximum peak load of proposed sandwich panels. The best design of the panel is recommended with 1.8 mm face sheet thickness and 5 mm pins diameter.
Monolith is an emerging technology applicable for separation, filtration, and chromatography due to its interconnected pore structure. However, the current templates used to form monolith pores are associated with poor heat dissipation, uneven pore size distribution, and relatively low mechanical strength during monolith scale-up. Templates made from polymeric microsphere particles were synthesized via a solvent evaporation technique using different types of polymer (polystyrene, polycaprolactone, polypropylene, polyethylene, and poly (vinyl-alcohol) at varied polymer (10-40 wt%) and surfactant (5-10%) concentrations. The resulting microsphere particles were tested as a monolith template for the formation of homogenous pores. Among the tested polymers, polystyrene at 10 wt% concentration demonstrated good particle morphology determined to around 1.94-3.45 µm. The addition of surfactant at a concentration of 7-10 wt% during microsphere synthesis resulted in the formation of well-shaped and non-aggregating microsphere particles. In addition, the template has contributed to the production of porous monoliths with enhanced thermal stability. The thermogravimetric analysis (TGA) indicated monolith degradation between 230 °C and 450 °C, implying the material excellent mechanical strength. The findings of the study provide insightful knowledge on the feasibility of polymeric microsphere particles as a pore-directing template to fabricate monoliths with desired pore structures.