Arabinoxylan (AX) is a natural biological macromolecule with several potential biomedical applications. In this research, AX, nano-hydroxyapatite (n-HAp) and titanium dioxide (TiO2) based polymeric nanocomposite scaffolds were fabricated by the freeze-drying method. The physicochemical characterizations of these polymeric nanocomposite scaffolds were performed for surface morphology, porosity, swelling, biodegradability, mechanical, and biological properties. The scaffolds exhibited good porosity and rough surface morphology, which were efficiently controlled by TiO2 concentrations. MC3T3-E1 cells were employed to conduct the biocompatibility of these scaffolds. Scaffolds showed unique biocompatibility in vitro and was favorable for cell attachment and growth. PNS3 proved more biocompatible, showed interconnected porosity and substantial mechanical strength compared to PNS1, PNS2 and PNS4. Furthermore, it has also showed more affinity to cells and cell growth. The results illustrated that the bioactive nanocomposite scaffold has the potential to find applications in the tissue engineering field.
Areca cattechu Linn is commonly known as areca nut or betel nut. It is a very widely cultivated plant in eastern countries like India, Bangladesh, Ceylon, Malaya, the Philippines and Japan. The importance of this nut is due to its use for chewing purposes. It had an important place as a pharmaceutical in Ayurveda--the ancient Indian system of medicine--also in the Chinese medicinal practices. The pharmaceutical importance of areca nut is due to the presence of an alkaloid, arecoline. Synthetic arecoline hydrobromide is also shown to possess numerous pharmacological properties. Chewing of "betel quid" or areca nut is a typical oriental habit. Betel quid comprises betel leaf, areca nut, catechu, lime and sometimes also tobacco. It is shown that there exists a correlationship between betel quid or areca nut chewing habit and oral cancer. A number of investigators have been able to produce cellular changes such as leukoplakia by application of betel quid or areca nut extract to the buccal mucosa of different animal.
A feasible production of poly (methyl methacrylate)@alloy (gold-silver) core shell has
been presented as candidate in enhanced detection of surface enhanced Raman scattering
(SERS). Free emulsifier- emulsion synthesised PMMA sphere with average size of 419 nm in
diameter were used as core material for incorporation of alloy nanoparticles (6 nm) resulting
a core-shell structure. The fabrication of PMMA@alloy SERS substrate was successfully
done via self-assembly thus the produced SERS substrate that comprise of unique optical
properties combination arising from periodic core arrangement and plasmonic activity of
alloy nanoparticles. Alloy is bimetallic nanoparticles in which the combination of silver
(Ag) and gold (Au) present an absolutely improved light resistance as compared to single
metal alone with great surface plasmon resonance. Morphology and elemental analysis was
performed through scanning electron microscope (SEM) and the analysis showing species of
both Au and Ag in single alloy nanoparticles. The alloy nanoparticles were also observed to
homogenously coating the PMMA sphere. Surface plasmon resonance activity was maximum
at 476 nm obtained from UV-Visible spectroscopy. High surface production was observed
to have periodically arranged PMMA@alloy core -shell and potentially to be used as SERS
substrate.
Aloe vera (AV) and tetracycline hydrochloride (TCH) exhibit significant properties such as anti-inflammatory, antioxidant and anti-bacterial activities to facilitate skin tissue engineering. The present study aims to develop poly-ε-caprolactone (PCL)/ AV containing curcumin (CUR), and TCH loaded hybrid nanofibrous scaffolds to validate the synergistic effect on the fibroblast proliferation and antimicrobial activity against Gram-positive and Gram-negative bacteria for wound healing. PCL/AV, PCL/CUR, PCL/AV/CUR and PCL/AV/TCH hybrid nanofibrous mats were fabricated using an electrospinning technique and were characterized for surface morphology, the successful incorporation of active compounds, hydrophilicity and the mechanical property of nanofibers. SEM revealed that there was a decrease in the fiber diameter (ranging from 360 to 770 nm) upon the addition of AV, CUR and TCH in PCL nanofibers, which were randomly oriented with bead free morphology. FTIR spectra of various electrospun samples confirmed the successful incorporation of AV, CUR and TCH into the PCL nanofibers. The fabricated nanofibrous scaffolds possessed mechanical properties within the range of human skin. The biocompatibility of electrospun nanofibrous scaffolds were evaluated on primary human dermal fibroblasts (hDF) by MTS assay, CMFDA, Sirius red and F-actin stainings. The results showed that the fabricated PCL/AV/CUR and PCL/AV/TCH nanofibrous scaffolds were non-toxic and had the potential for wound healing applications. The disc diffusion assay confirmed that the electrospun nanofibrous scaffolds possessed antibacterial activity and provided an effective wound dressing for skin tissue engineering.
A series of heteroatom-containing porous carbons with high surface area and hierarchical porosity were successfully prepared by hydrothermal, chemical activation, and carbonization processes from soybean residues. The initial concentration of soybean residues has a significant impact on the textural and surface functional properties of the obtained biomass-derived porous carbons (BDPCs). SRAC5 sample with a BET surface area of 1945 m2 g-1 and a wide micro/mesopore size distribution, nitrogen content of 3.8 at %, and oxygen content of 15.8 at % presents the best electrochemical performance, reaching 489 F g-1 at 1 A g-1 in 6 M LiNO3 aqueous solution. A solid-state symmetric supercapacitor (SSC) device delivers a specific capacitance of 123 F g-1 at 1 A g-1 and a high energy density of 68.2 Wh kg-1 at a power density of 1 kW kg-1 with a wide voltage window of 2.0 V and maintains good cycling stability of 89.9% capacitance retention at 2A g-1 (over 5000 cycles). The outstanding electrochemical performances are ascribed to the synergistic effects of the high specific surface area, appropriate pore distribution, favorable heteroatom functional groups, and suitable electrolyte, which facilitates electrical double-layer and pseudocapacitive mechanisms for power and energy storage, respectively.
Spectroscopic and calorimetric methods were employed to assess the stability and the folding aspect of a novel recombinant alkaline-stable lipase KV1 from Acinetobacter haemolyticus under varying pH and temperature. Data on far ultraviolet-circular dichroism of recombinant lipase KV1 under two alkaline conditions (pH 8.0 and 12.0) at 40 °C reveal strong negative ellipticities at 208, 217, 222 nm, implying its secondary structure belonging to a α + β class with 47.3 and 39.0% ellipticity, respectively. Results demonstrate that lipase KV1 adopts its most stable conformation at pH 8.0 and 40 °C. Conversely, the protein assumes a random coil structure at pH 4.0 and 80 °C, evident from a strong negative peak at ∼ 200 nm. This blue shift suggests a general decline in enzyme activity in conjunction with the partially or fully unfolded state that invariably exposed more hydrophobic surfaces of the lipase protein. The maximum emission at ∼335 nm for pH 8.0 and 40 °C indicates the adoption of a favorable protein conformation with a high number of buried tryptophan residues, reducing solvent exposure. Appearance of an intense Amide I absorption band at pH 8.0 corroborates an intact secondary structure. A lower enthalpy value for pH 4.0 over pH 8.0 and 12.0 in the differential scanning calorimetric data corroborates the stability of the lipase at alkaline conditions, while a low Km (0.68 ± 0.03 mM) for tributyrin verifies the high affinity of lipase KV1 for the substrate. The data, herein offer useful insights into future structure-based tunable catalytic activity of lipase KV1.
Cardiovascular disease is a major global health issue. In particular, acute myocardial infarction (AMI) requires urgent attention and early diagnosis. The use of point-of-care diagnostics has resulted in the improved management of cardiovascular disease, but a major drawback is that the performance of POC devices does not rival that of central laboratory tests. Recently, many studies and advances have been made in the field of surface-enhanced Raman scattering (SERS), including the development of POC biosensors that utilize this detection method. Here, we present a review of the strengths and limitations of these emerging SERS-based biosensors for AMI diagnosis. The ability of SERS to multiplex sensing against existing POC detection methods are compared and discussed. Furthermore, SERS calibration-free methods that have recently been explored to minimize the inconvenience and eliminate the limitations caused by the limited linear range and interassay differences found in the calibration curves are outlined. In addition, the incorporation of artificial intelligence (AI) in SERS techniques to promote multivariate analysis and enhance diagnostic accuracy are discussed. The future prospects for SERS-based POC devices that include wearable POC SERS devices toward predictive, personalized medicine following the Fourth Industrial Revolution are proposed.
Anatase titanium dioxide nanoparticles (TiO2-NPs) were synthesized by sol-gel method using rice straw as a soft biotemplate. Rice straw, as a lignocellulosic waste material, is a biomass feedstock which is globally produced in high rate and could be utilized in an innovative approach to manufacture a value-added product. Rice straw as a reliable biotemplate has been used in the sol-gel method to synthesize ultrasmall sizes of TiO2-NPs with high potential application in photocatalysis. The physicochemical properties of titanium dioxide nanoparticles were investigated by a number of techniques such as X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis (TGA), ultraviolet visible spectra (UV-Vis), and surface area and pore size analysis. All results consensually confirmed that particle sizes of synthesized titanium dioxide were template-dependent, representing decrease in the nanoparticles sizes with increase of biotemplate concentration. Titanium dioxide nanoparticles as small as 13.0 ± 3.3 nm were obtained under our experimental conditions. Additionally, surface area and porosity of synthesized TiO2-NPs have been enhanced by increasing rice straw amount which results in surface modification of nanoparticles and potential application in photocatalysis.
A crosslinked chitosan-glyoxal/TiO2 nanocomposite (CCG/TNC) was synthesized by loading different ratios of TiO2 nanoparticles into polymeric matrix of crosslinked chitosan-glyoxal (CCG) to be a promising biosorbent for methyl orange (MO). Box-Behnken design (BBD) in response surface methodology (RSM) was applied to optimize various process parameters, viz., loading of TiO2 nanoparticles into CCG polymeric matrix (A: 0%-50%), adsorbent dose (B: 0.04-0.14 g/50 mL), solution pH (C: 4-10), and temperature (D: 30-50 °C). The highest MO removal efficiency of 75.9% was observed by simultaneous interactions between AB, AC, and BC. The optimum TiO2 loading, adsorbent dosage, solution pH, and temperature were (50% TiO2: 50% chitosan labeled as CCG/TNC-50), 0.09 g/50 mL, 4.0, and 40 °C. The adsorption of MO from aqueous solution by using CCG/TNC-50 in batch mode was evaluated. The kinetic results were well described by the pseudo-first order kinetic, and the equilibrium data were in agreement with Langmuir isotherm model with maximum adsorption capacity of 416.1 mg/g. The adsorption mechanism included electrostatic attractions, n-π stacking interactions, dipole-dipole hydrogen bonding interactions, and Yoshida H-bonding.
Introduction: Intracranial brain tumour like meningiomas and glioblastomas are most prevalent tumour. The metas- tasis to the brain is one of the major issues in the tumours of the central nervous system. The diagnosis of metastatic and primary brain tumour is incomprehensible with standard magnetic resonance imaging (MRI). The magnetic res- onance spectroscopy (MRS) is basically performed in standard clinical setting for diagnosing and tracking the brain tumour. Method: It is a retrospective study containing 53 patients with MRS. The patients with metastatic tumour (n=10), glioblastomas (n=8) and meningiomas (n=20) are included in the study. Single voxel technique is applied in the tumour core to determine the metabolites. The tumour N-acetyl aspartate (NAA), Choline (Cho), Creatine (Cr), Lactate, Alanine and lipids were analysed. The ratios of NAA/Cr, Cho/NAA and Cho/Cr were recorded and com- pared between the three tumours. The metabolites were detected between short echo time (TE) to long echo time (TE) during MRS. Results: There is a sharp fall of NAA peak in metastatic tumour. The resonance of creatine, lactate and alanine is higher in glioblastomas. A high lipid mean value of 3.13(0.17) is seen in metastatic tumour. The ROC curve shows a low NAA/Cr specificity of 46.7%, high sensitivity of 83.3% in Cho/NAA and Cho/Cr ratio. Conclusion: The metabolic profiles of metastatic brain tumour, glioblastomas and meningioma illustrate a divergence in their description that will assist in planning therapeutic and surgical intervention of these tumours.
A photoelectrochemical (PEC) sensor with excellent sensitivity and detection toward copper (II) ions (Cu2+) was developed using a cadmium sulphide-reduced graphene oxide (CdS-rGO) nanocomposite on an indium tin oxide (ITO) surface, with triethanolamine (TEA) used as the sacrificial electron donor. The CdS nanoparticles were initially synthesized via the aerosol-assisted chemical vapor deposition (AACVD) method using cadmium acetate and thiourea as the precursors to Cd2+ and S2-, respectively. Graphene oxide (GO) was then dip-coated onto the CdS electrode and sintered under an argon gas flow (50 mL/min) for the reduction process. The nanostructured CdS was adhered securely to the ITO by a continuous network of rGO that also acted as an avenue to intensify the transfer of electrons from the conduction band of CdS. The photoelectrochemical results indicated that the ITO/CdS-rGO photoelectrode could facilitate broad UV-visible light absorption, which would lead to a higher and steady-state photocurrent response in the presence of TEA in 0.1 M KCl. The photocurrent decreased with an increase in the concentration of Cu2+ ions. The photoelectrode response for Cu2+ ion detection had a linear range of 0.5-120 μM, with a limit of detection (LoD) of 16 nM. The proposed PEC sensor displayed ultra-sensitivity and good selectivity toward Cu2+ ion detection.
Various classification methods have been applied for low resolution of the entire Earth's surface from recorded satellite images, but insufficient study has determined which method, for which satellite data, is economically viable for tropical forest land use mapping. This study employed Iterative Self Organizing Data Analysis Techniques (ISODATA) and K-Means classification techniques to classified Moderate Resolution Imaging Spectroradiometer (MODIS) Surface Reflectance satellite image into forests, oil palm groves, rubber plantations, mixed horticulture, mixed oil palm and rubber and mixed forest and rubber. Even though frequent cloud cover has been a challenge for mapping tropical forests, our MODIS land use classification map found that 2008 ISODATA-1 performed well with overall accuracy of 94%, with the highest Producer's Accuracy of Forest with 86%, and were consistent with MODIS Land Cover 2008 (MOD12Q1), respectively. The MODIS land use classification was able to distinguish young oil palm groves from open areas, rubber and mature oil palm plantations, on the Advanced Land Observing Satellite (ALOS) map, whereas rubber was more easily distinguished from an open area than from mixed rubber and forest. This study provides insight on the potential for integrating regional databases and temporal MODIS data, in order to map land use in tropical forest regions.
Carbon nanotube-quicklime nanocomposites (CQNs) have been synthesized via the chemical vapor deposition (CVD) of n-hexane using a nickel metal catalyst supported on calcined carbonate stones at temperatures of 600-900 °C. The use of a Ni/CaO(10 wt%) catalyst required temperatures of at least 700 °C to obtain XRD peaks attributable to carbon nanotubes (CNTs). The CQNs prepared using a Ni/CaO catalyst of various Ni contents showed varying diameters and the remaining catalyst metal particles could still be observed in the samples. Thermogravimetric analysis of the CQNs showed that there were two major weight losses due to the amorphous carbon decomposition (300-400 °C) and oxidation of CNTs (400-600 °C). Raman spectroscopy results showed that the CQNs with the highest graphitization were synthesized using Ni/CaO (10 wt%) at 800 °C with an IG/ID ratio of 1.30. The cyclic voltammetry (CV) of screen-printed carbon electrodes (SPCEs) modified with the CQNs showed that the performance of nanocomposite-modified SPCEs were better than bare SPCEs. When compared to carboxylated multi-walled carbon nanotubes or MWNT-COOH-modified SPCEs, the CQNs synthesized using Ni/CaO (10 wt%) at 800 °C gave higher CV peak currents and comparable electron transfer, making it a good alternative for screen-printed electrode modification.
In seabed logging the magnitude of electromagnetic (EM) waves for the detection of a hydrocarbon reservoir in the marine environment is very important. Having a strong EM source for exploration target 4000 m below the sea floor is a very challenging task. A new carbon nanotubes (CNT) fibres/aluminium based EM transmitter is developed and NiZn ferrite as magnetic feeders was used in a scaled tank to evaluate the presence of oil. Resistive scaled tank experiments with a scale factor of 2000 were carried out. X-ray Diffraction (XRD), Raman Spectroscopy and Field Emission Scanning Electron Microscope (FESEM) were done to characterize the synthesized magnetic feeders. Single phase Ni0.76Mg0.04Zn0.2Fe2O4, obtained by the sol-gel method and sintered at 700 degrees C in air, has a [311] major peak. FESEM results show nanoparticles with average diameters of 17-45 nm. Samples which have a high Q-factor (approximately 50) was used as magnetic feeders for the EM transmitter. The magnitude of the EM waves of this new EM transmitter increases up to 400%. A curve fitting method using MATLAB software was done to evaluate the performance of the new EM transmitter. The correlation value with CNT fibres/aluminium-NiZnFe2O4 base transmitter shows a 152.5% increase of the magnetic field strength in the presence of oil. Modelling of the scale tank which replicates the marine environment was done using the Finite Element Method (FEM). In conclusion, FEM was able to delineate the presence of oil with greater magnitude of E-field (16.89%) and the B field (4.20%) due to the new EM transmitter.
The present work describesthe development of highly potent mushroom tyrosinase inhibitor better than the standard kojic acid. Carvacrol derivatives 4a-f and 6a-d having substituted benzoic acid and cinnamic acidresidues were synthesized with the aim to possess potent tyrosinase inhibitory activity.The structures of the synthesized compounds were ascertained by their spectroscopic data (FTIR, 1HNMR, 13CNMR and Mass Spectroscopy).Mushroom tyrosinase inhibitory activity of synthesized compounds was determined and it was found that one of the derivative 6c possess higher activity (IC50 0.0167μM) than standard kojic acid (IC50 16.69μM). The derivatives 4c and 6b also showed good tyrosinase inhibitory activity with (IC50 16.69μM) and (IC50 16.69μM) respectively.Lineweaver-Burk and Dixon plots were used for the determination of kinetic mechanism of the compounds 4c and 6b and 6c. The kinetic analysis revealed that compounds 4c and 6b showed mixed-type inhibition while 6c is a non-competitive inhibitor having Ki values19 μM, 10 μM, and 0.05 μMrespectively. The enzyme inhibitory kinetics further showed thatcompounds 6b and 6c formed irreversible enzyme inhibitor complex while 4c bind reversibly with mushroom tyrosinase.The docking studies showed that compound 6c have maximum binding affinity against mushroom tyrosinase (PDBID: 2Y9X) with binding energy value (-7.90 kcal/mol) as compared to others.The 2-hydroxy group in compound 6c interacts with amino acid HIS85 which is present in active binding site. The wet lab results are in good agreement with the dry lab findings.Based upon our investigation we may propose that the compound 6c is promising candidate for the development of safe cosmetic agent.
Immobilisation of aptameric ligands on solid stationary supports for effective binding of target molecules requires understanding of the relationship between aptamer-polymer interactions and the conditions governing the mass transfer of the binding process. Herein, key process parameters affecting the molecular anchoring of a thrombin-binding aptamer (TBA) onto polymethacrylate monolith pore surface, and the binding characteristics of the resulting macroporous aptasensor were investigated. Molecular dynamics (MD) simulations of the TBA-thrombin binding indicated enhanced Guanine 4 (G4) structural stability of TBA upon interaction with thrombin in an ionic environment. Fourier-transform infrared spectroscopy and thermogravimetric analyses were used to characterise the available functional groups and thermo-molecular stability of the immobilised polymer generated with Schiff-base activation and immobilisation scheme. The initial degradation temperature of the polymethacrylate stationary support increased with each step of the Schiff-base process: poly(Ethylene glycol Dimethacrylate-co-Glycidyl methacrylate) or poly(EDMA-co-GMA) [196.0 °C (±1.8)]; poly(EDMA-co-GMA)-Ethylenediamine [235.9 °C (±6.1)]; poly(EDMA-co-GMA)-Ethylenediamine-Glutaraldehyde [255.4 °C (±2.7)]; and aptamer-modified monolith [273.7 °C (±2.5)]. These initial temperature increments reflected in the associated endothermic energies were determined with differential scanning calorimetry. The aptameric ligand density obtained after immobilisation was 480 pmol/μL. Increase in pH and ionic concentration affected the surface charge distribution and the binding characteristics of the aptamer-modified disk-monoliths, resulting in the optimum binding pH and ionic concentration of 8.0 and 5 mM Mg2+, respectively. These results are critical in understanding and setting parametric constraints indispensable to develop and enhance the performance of aptasensors.
Proton Transfer Reaction - Mass Spectrometry (PTR-MS) is a sensitive, soft ionisation method suitable for qualitative and quantitative analysis of volatile and semi-volatile organic vapours. PTR-MS is used for various environmental applications including monitoring of volatile organic compounds (VOCs) emitted from natural and anthropogenic sources, chemical composition measurements of aerosols, etc. Here we apply thermal desorption PTR-MS for the first time to characterise the chemical composition of dissolved organic matter (DOM). We developed a clean, low-pressure evaporation/sublimation system to remove water from samples and coupled it to a custom-made thermal desorption unit to introduce the samples to the PTR-MS. Using this system, we analysed waters from intact and degraded peat swamp forest of Kalimantan, Indonesian Borneo, and an oil palm plantation and natural forest in Sarawak, Malaysian Borneo. We detected more than 200 organic ions from these samples and principal component analysis allowed clear separation of the different sample origins based on the composition of organic compounds. The method is sensitive, reproducible, and provides a new and comparatively cheap tool for a rapid characterisation of water and soil DOM.
Novel polyethersulfone (PES) membranes blended with 0.1-3.0 wt. % of Acacia gum (AG) as a pore-former and antifouling agent were fabricated using phase inversion technique. The effect of AG on the pore-size, porosity, surface morphology, surface charge, hydrophilicity, and mechanical properties of PES/AG membranes was studied by scanning electron microscopy (SEM), Raman spectroscopy, contact angle and zeta potential measurements. The antifouling -properties of PES/AG membranes were evaluated using Escherichia coli bacteria and bovine serum albumine (BSA). The use of AG as an additive to PES membranes was found to increase the surface charge, hydrophilicity (by 20%), porosity (by 77%) and permeate flux (by about 130%). Moreover, PES/AG membranes demonstrated higher antifouling and tensile stress (by 31%) when compared to pure PES membranes. It was shown that the prepared PES/AG membranes efficiently removed lead ions from aqueous solutions. Both the sieving mechanism of the membrane and chelation of lead with AG macromolecules incorporated in the membrane matrix contributed to lead removal. The obtained results indicated that AG can be used as a novel pore-former, hydrophilizing and antifouling agent, as well as an enhancer to the mechanical and rejection properties of the PES membranes.
Oil palm empty fruit bunch graft poly (acrylic acid-co-acrylamide) superabsorbent composite (OPEFB-g-(PAA-co-PAM) SAPC) was synthesized by graft copolymerization of the acrylic acid (AA) and acrylamide (AM) comonomer onto OPEFB fibre using ammonium persulfate (APS) and N,N-methylene bisacarylamide (MBA) as an initiator and crosslinker, respectively. The absorbency in various chloride salt solutions indicated that the absorbency decreased with increasing ionic strength of the salt solutions. Moreover, the absorbency under load (AUL) of SAPC was investigated at various applied loading and results show that, AUL decreased with increasing applied loading. Infrared Spectroscopy (IR) and Thermogravimetric Analysis (TGA) were carried out to confirm the chemical structure and thermal properties of the synthesized superabsorbent, respectively.
A novel DNA biosensing platform was designed by the functionalization of iron oxide (Fe3O4)
with the carboxylic group via capping agent, mercaptopropionic acid (MPA) and conjugated
with nanocellulose crystalline (NCC) surface modified with surfactant cetyltrimethylammonium
bromide (CTAB) to assist in the DNA sensing capability. The product of nanocomposites
compound was drop-casted on screen printed carbon electrode (SPCE). Characterization by field
emission scanning electron microscope (FESEM) and energy dispersive X-Ray (EDX)
spectroscopy showing that carboxyl functionalized iron oxide (COOH-Fe3O4) can be hybridized
with NCC-CTA+ via electrostatic interaction.