Periodic travelling waves in cyclic populations: field studies and reaction–diffusion models

Periodic travelling waves have been reported in a number of recent spatio-temporal field studies of populations undergoing multi-year cycles. Mathematical modelling has a major role to play in understanding these results and informing future empirical studies. We review the relevant field data and summarize the statistical methods used to detect periodic waves. We then discuss the mathematical theory of periodic travelling waves in oscillatory reaction-diffusion equations. We describe the notion of a wave family, and various ecologically relevant scenarios in which periodic travelling waves occur. We also discuss wave stability, including recent computational developments. Although we focus on oscillatory reaction-diffusion equations, a brief discussion of other types of model in which periodic travelling waves have been demonstrated is also included. We end by proposing 10 research challenges in this area, five mathematical and five empirical.     

Incorporating domain growth into hybrid methods for reaction–diffusion systems

Reaction–diffusion mechanisms are a robust paradigm that can be used to represent many biological and physical phenomena over multiple spatial scales. Applications include intracellular dynamics, the migration of cells and the patterns formed by vegetation in semi-arid landscapes. Moreover, domain growth is an important process for embryonic growth and wound healing. There are many numerical modelling frameworks capable of simulating such systems on growing domains; however, each of these may be well suited to different spatial scales and particle numbers. Recently, spatially extended hybrid methods on static domains have been produced to bridge the gap between these different modelling paradigms in order to represent multi-scale phenomena. However, such methods have not been developed with domain growth in mind. In this paper, we develop three hybrid methods on growing domains, extending three of the prominent static-domain hybrid methods. We also provide detailed algorithms to allow others to employ them. We demonstrate that the methods are able to accurately model three representative reaction–diffusion systems accurately and without bias.     

Patient mood flux on‐ and off‐hemodialysis

Mood in hemodialysis patients is most often evaluated off‐dialysis, possibly underestimating mood during dialysis. We compared mood in patients on‐ and off‐dialysis using the Positive and Negative Affect Schedule for 6 consecutive days. Initially, scores are normal, but subsequently positive affect falls below, and negative affect increases above, off‐dialysis values, suggesting increasing depression and anxiety, particularly in women. Quality‐of‐life questions confirm the effects of the dialysis session on mood. Prevalence and severity of depression evaluated off‐dialysis, or once only, may be underestimated, especially in women, because hemodialysis patients undergo mood swings centering on the dialysis session. Focusing insight on the dialysis session could improve coping among patients and caretakers.     

Analysis of healthy and tumour DNA methylation distributions in kidney‐renal‐clear‐cell‐carcinoma using Kullback–Leibler and Jensen–Shannon distance measures

DNA methylation is an epigenetic phenomenon in which methyl groups get bonded to the cytosines of the DNA molecule altering the expression of the associated genes. Cancer is linked with hypo or hyper‐methylation of specific genes as well as global changes in DNA methylation. In this study, the authors study the probability density function distribution of DNA methylation in various significant genes and across the genome in healthy and tumour samples. They propose a unique ‘average healthy methylation distribution’ based on the methylation values of several healthy samples. They then obtain the Kullback–Leibler and Jensen–Shannon distances between methylation distributions of the healthy and tumour samples and the average healthy methylation distribution. The distance measures of the healthy and tumour samples from the average healthy methylation distribution are compared and the differences in the distances are analysed as possible parameters for cancer. A classifier trained on these values was found to provide high values of sensitivity and specificity. They consider this to be a computationally efficient approach to predict tumour samples based on DNA methylation data. This technique can also be improvised to consider other differentially methylated genes significant in cancer or other epigenetic diseases.Inspec keywords: cancer, tumours, DNA, genetics, molecular biophysicsOther keywords: tumour DNA methylation distributions, kidney‐renal‐clear‐cell‐carcinoma, Kullback–Leibler distance measure, Jensen–Shannon distance measure, epigenetic phenomenon, methyl groups, cytosines, hyper‐methylation, probability density function distribution, average healthy methylation distribution     

Synthesis and studies of bay‐substituted perylene diimide‐based D–A–D‐type SM acceptors for OSC and antimicrobial applications

In this study, the synthesis of a series of bay‐substituted donor–acceptor–donor (D–A–D) type perylene diimide derivatives (3a–3d) has been reported as an acceptor for the small‐molecule‐based organic solar cells (SM‐OSCs) by the Suzuki coupling method. It has been evaluated for the antimicrobial activity against some of the bacteria and fungi. The synthesised SMs were confirmed by Fourier transform‐infrared spectroscopy, nuclear magnetic resonance (NMR), and high resolution mass spectroscopy (HR‐MS). The SMs showed absorption up to 750 nm, which eventually reduced the optical band gap Egopt to  < 2 eV. SMs showed thermal stability up to 400 °C. In the SM‐OSC, the SMs showed a power conversion efficiency of  < 1% with the P3HT donor in bulk hetero‐junction device structure. Additionally, the new SMs showed antimicrobial activity against Gram‐negative bacteria such as Escherichia coli Gram‐positive bacteria such as Bacillus subtilis and antifungal activity against the Candida albicans, and Aspergillus niger. Cytotoxicity studies were carried out against the breast cancer cell lines MCF‐7 using MTT assay method. The results revealed that the SMs was able to inhibit the cancer cells. LD₅₀ s calculated for the SMs 3a–3d were between 200 and 400 µg/ml.Inspec keywords: antibacterial activity, solar cells, microorganisms, Fourier transform spectra, infrared spectra, nuclear magnetic resonance, photonic band gap, thermal stability, cellular biophysics, toxicology, cancer, nanomedicine, organic semiconductors, mass spectroscopy, biomedical materialsOther keywords: bay‐substituted perylene diimide‐based D‐A‐D‐type SM acceptors, donor‐acceptor‐donor type perylene diimide derivatives, small‐molecule‐based organic solar cells, SM‐OSC, Suzuki coupling method, antimicrobial activity, bacteria, fungi, Fourier transform infrared spectroscopy, NMR, HR‐MS, optical band gap, P3HT donor, bulk hetero‐junction device structure, Gram‐negative bacteria, Escherichia coli Gram‐positive bacteria, Bacillus subtilis, antifungal activity, Candida albicans, Aspergillus niger, cytotoxicity, breast cancer cell lines MCF‐7, MTT assay method, cancer cells, wavelength 750 nm, temperature 400 degC     

Anti‐biofilm and anti‐virulence effects of silica oxide nanoparticle–conjugation of lectin purified from Pseudomonas aeruginosa

Pseudomonas aeruginosa lectin is purified and nanoparticle‐conjugated in an attempt to inhibit biofilm formation. Thirteen (23.6%) P. aeruginosa isolates are obtained from chicken meat samples, of which 30.8% are biofilm producers and 69.2% are lectin producers. Lectin is purified 36.8‐fold to final specific activity of 506.9 U/mg. Four nanoparticle types are prepared via laser ablation: platinum (Pt), gold (Au), silica oxide (SiO₂), and tin oxide (SnO₂). The four types are characterised, and pulse feeding is used to conjugate the lectin and nanoparticles. Pt, Au, SiO_2, and SnO₂ nanoparticles inhibit biofilm formation, especially SiO₂ nanoparticles, which have higher effectiveness when conjugated with purified lectin. SiO₂‐conjugated lectin significantly (p < 0.05) inhibits biofilm formation more effectively than control and other nanoparticle‐conjugated lectins. Au‐, Pt nanoparticle‐, and SnO₂‐conjugated lectins inhibit biofilm significantly compared with control (p < 0.05), and rhlR gene expression is decreased in the presence of SiO₂‐conjugated lectin. Furthermore, lectin and Pt, Au, SiO₂ and SnO₂ nanoparticles separately, and their conjugated lectins, are effective biofilm inhibitors. Of these, SiO₂‐conjugated lectin was most significant as an anti‐biofilm. Moreover, virulence factors regulon and RhlR were reduced by SiO₂‐conjugated lectin, indicating that this conjugation may also decrease the virulence of P. aeruginosa.     

N ‐acetylcysteine–PLGA nano‐conjugate: effects on cellular toxicity and uptake of gadopentate dimeglumine

Gadolinium as a contrast agent in MRI technique combined with DTPA causes contrast induced nephropathy (CIN) and nephrogenic systemic fibrosis (NSF) which can reduce by usage of antioxidants such as N‐acetyl cysteine by increasing the membrane''s permeability leads to lower cytotoxicity. In this study, N ‐acetyl cysteine‐PLGA Nano‐conjugate was synthesized according to stoichiometric rules of molar ratios andafter assessment by FTIR, NMR spectroscopy and Atomic Force Microscopy (AFM) imaging was combined with Magnevist® (gadopentetate dimeglumine) and its effects on the renal cells were evaluated. MTT [3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐Diphenyltetrazolium Bromide] and cellular uptake assays have indicated relatively significant toxicity of magnevist (P  < 0.05) on three cell lines including HEK293, MCF7 and L929 compared to other synthesized ligands that shown no toxicity. Moreover, systemic evaluation has shown no notable changes of blood urea nitrogen (BUN) and creatinine in kidney of mice. In consequence, antioxidant effect was increased as well as the renal toxicity of the contrast agent reduced at the cell level. As a result, PLGA‐NAC nano‐conjugate can be a promising choice for decreasing the magnevist toxicity for treatment and prevention of CIN and will be able to open a new horizon to research on reduction of toxicity of contrast agents by using nanoparticles.Inspec keywords: blood, toxicology, nanofabrication, cellular biophysics, biomedical materials, nanoparticles, chromatography, cancer, biodegradable materials, biomedical MRI, kidney, pH, nanomedicine, patient treatment, diseases, atomic force microscopy, Fourier transform infrared spectraOther keywords: cellular toxicity, gadopentate dimeglumine, contrast agent, magnetic resonance imaging technique, diethylenetriamine pentaacetate, contrast‐induced nephropathy, nephrogenic systemic fibrosis, stoichiometric rules, molar ratios, dimethyl sulphoxide solution, chromatography techniques, nuclear magnetic resonance spectroscopy, atomic force microscopy imaging, Magnevist®, gadopentetate dimeglumine, renal cells, MTT cytotoxicity, human embryonic kidney‐293, L929 cell lines, in vitro conditions, cellular uptake assays, Magnevist uptake, antioxidant effect, renal toxicity, cell level, PLGA nanocarrier, acetylcysteine nanoconjugate, Magnevist toxicity, N‐acetylcysteine–PLGA nano‐conjugate, N‐acetyl cysteine‐poly‐lactic‐co‐glycolic acid nanoconjugate     

Co–Sn–Cu oxides/graphene nanocomposites as green catalysts for preparing 1,8‐dioxo‐octahydroxanthenes and apoptosis‐inducing agents in MCF‐7 human breast cancer cells

In this work, Co–Sn–Cu oxides/graphene nanocomposite, 30–40 ± 0.5 nm in size, was synthesized by solid‐state microwave irradiation. This method presents several advantages such as operational simplicity, fast, low cost, safe and energy efficient, and suitability for production of high purity of nanoparticles. Other advantages of this method are there is no need for the use of solvent, fuel, and surfactant. Co–Sn–Cu oxides/graphene nanocomposites have been characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometer, energy‐dispersive X–ray spectroscopy, and UV–Vis spectroscopy. The synthesized nanocomposites were used as novel highly efficient catalysts for the synthesis of 1,8‐dioxo‐octahydroxanthenes at room temperature. The catalysts are recoverable and can be reused for six runs without loss of their activity. Also, the obtained nanocomposites exhibited significant anticancer activity against breast cancer cells and they could induce apoptosis in cancer cells.     

Period–amplitude co‐variation in biomolecular oscillators

The period and amplitude of biomolecular oscillators are functionally important properties in multiple contexts. For a biomolecular oscillator, the overall constraints in how tuning of amplitude affects period, and vice versa, are generally unclear. Here, the authors investigate this co‐variation of the period and amplitude in mathematical models of biomolecular oscillators using both simulations and analytical approximations. The authors computed the amplitude–period co‐variation of 11 benchmark biomolecular oscillators as their parameters were individually varied around a nominal value, classifying the various co‐variation patterns such as a simultaneous increase/decrease in period and amplitude. Next, the authors repeated the classification using a power norm‐based amplitude metric, to account for the amplitudes of the many biomolecular species that may be part of the oscillations, finding largely similar trends. Finally, the authors calculate ‘scaling laws’ of period–amplitude co‐variation for a subset of these benchmark oscillators finding that as the approximated period increases, the upper bound of the amplitude increases, or reaches a constant value. Based on these results, the authors discuss the effect of different parameters on the type of period–amplitude co‐variation as well as the difficulty in achieving an oscillation with large amplitude and small period.Inspec keywords: molecular biophysics, oscillations, biology computing, circadian rhythmsOther keywords: period‐amplitude co‐variation, biomolecular oscillators, mathematical models, analytical approximations, co‐variation patterns, power norm‐based amplitude metric, scaling laws     

TiO2 /chondroitin‐4‐sulphate nanocomposite coating on Ti–6Al–4V for implants and prostheses applications

Nano‐titania, chondroitin‐4‐sulphate, and titania/chondroitin‐4‐sulphate nanocomposite were separately deposited on Ti–6Al–4V alloys by repetitive spin coating. Surface characterisation techniques were used to find out the crystalline nature, chemical bonding, surface homogeneity, and elemental composition. Biological studies of nanocomposite‐coated alloys revealed the formation of stable hydroxyapatite (Ca/P = 1.678), superior corrosion resistance, and ∼12 mm zone of inhibition against Staphylococcus sp. However, the cell line studies revealed the better response on polymer‐coated alloy than the uncoated and composite‐coated alloy. It has been found that the nanocomposite coating can synergistically increase the thickness of the pre‐existing passive layer and thereby improve the corrosion resistance of Ti–6Al–4V implant in simulated body fluid. The nanocomposite coatings improved the corrosion resistance of the bare Ti–6Al–4V implant specimens by decreasing the i _corr. The formation of hydroxyapatite on nanocomposite‐coated alloy may have ability to inhibit the release of toxic substance to the adjacent tissues. In addition, the in vitro cell line study confers that the nanocomposite‐coated Ti–6Al–4V induces cell attachment and proliferation, and it eventually help to new bone cell formation than the uncoated one. Overall, this nanocomposite coating can be applied in orthopedic applications for effective biomimic bone regeneration.Inspec keywords: titanium compounds, nanocomposites, titanium alloys, aluminium alloys, vanadium alloys, nanomedicine, biomedical materials, prosthetics, X‐ray diffraction, Fourier transform spectra, infrared spectra, scanning electron microscopy, fluorescence, corrosion resistance, polymer films, calcium compounds, cellular biophysics, boneOther keywords: chondroitin‐4‐sulphate nanocomposite coating, implants, prostheses, nano‐titania, repetitive spin coating, surface characterisation, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray fluorescence, TiAlV, TiO₂ , effective biomimic bone regeneration, orthopaedic applications, bone cell formation, osteoblast cells, cell proliferation, cell attachment, simulated body fluid solution, composite‐coated alloy, polymer‐coated alloy, Staphylococcus sp, corrosion resistance, hydroxyapatite, elemental composition, surface homogeneity, chemical bonding, crystalline nature     

In‐situ fabrication of zirconium–titanium nano‐composite and its coating on Ti‐6Al‐4V for biomedical applications

In this study, nanocomposite powder consisting of zirconia and titania (Zr–Ti) have been synthesised by sol–gel method, with the aim of protecting Ti‐6Al‐4V surface. A simple and low cost electrophoretic deposition (EPD) technique has been employed for coating the nanocomposite material on Ti‐6Al‐4V. The prepared nanocomposite powder was characterised for its functional groups, phase purity, surface topography by Fourier transform infrared spectroscopy, powder X‐ray diffraction and scanning electron microscopy. Further, the biocompatibility nature of the composite powder was studied by [3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide] colorimetric assay and fluorescence analysis with MG63 osteoblast cell lines. The electrochemical behaviour of composite coating was investigated by potentiodynamic polarization and electrochemical impedance method. The results obtained from the electrochemical techniques indicate more corrosion resistance behaviour with increase of R _ct value with the corresponding decrease in R _dl values. From the above findings, the composite coating acts as a barrier layer against corrosion by preventing the leaching of metal ions from a dense and defect free coating. A scratch test analyser was used to assess the integrity of the coating; the lower traction force value of composite coating with increase in load has confirmed the presence of thick adherent layer on the substrate.Inspec keywords: zirconium compounds, titanium compounds, titanium alloys, aluminium alloys, vanadium alloys, nanofabrication, nanocomposites, nanoparticles, sol‐gel processing, electrophoretic coating techniques, surface topography, Fourier transform infrared spectra, X‐ray diffraction, scanning electron microscopy, X‐ray chemical analysis, fluorescence, cellular biophysics, biomedical materials, electrochemical impedance spectroscopy, corrosion resistance, corrosion protection, corrosion protective coatings, adhesionOther keywords: in‐situ fabrication, zirconium‐titanium nanocomposite powder, biomedical applications, zirconia, titania, sol‐gel method, electrophoretic deposition, EPD, functional groups, phase purity, surface topography, Fourier transform infrared spectroscopy, powder X‐ray diffraction, scanning electron microscopy, energy dispersive X‐ray analysis, biocompatibility, 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide colorimetric assay, acridine range fluorescence analysis, MG63 osteoblast cell lines, electrochemical behaviour, composite coating, potentiodynamic polarization, electrochemical impedance spectroscopy, corrosion resistance, barrier layer, leaching, defect free coating layer, scratch test analysis, adherent layer, TiAlV‐ZrO₂ ‐TiO₂      

Biogenic synthesis of biopolymer‐based Ag–Au bimetallic nanoparticle constructs and their anti‐proliferative assessment

This study reports an eco‐friendly‐based method for the preparation of biopolymer Ag–Au nanoparticles (NPs) by using gum kondagogu (GK; Cochlospermum gossypium), as both reducing and protecting agent. The formation of GK‐(Ag–Au) NPs was confirmed by UV‐absorption, fourier transformed infrared (FTIR), atomic force microscopy (AFM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The GK‐(Ag–Au) NPs were of 1–12 nm in size. The anti‐proliferative activity of nanoparticle constructs was assessed by MTT assay, confocal microscopy, flow cytometry and quantitative real‐time polymerase chain reaction (PCR) techniques. Expression studies revealed up‐regulation of p53, caspase‐3, caspase‐9, peroxisome proliferator‐activated receptors (PPAR) PPARa and PPARb, genes and down‐regulation of Bcl‐2 and Bcl‐x(K) genes, in B16F10 cells treated with GK‐(Ag–Au) NPs confirming the anti‐proliferative properties of the nanoparticles.Inspec keywords: nanomedicine, transmission electron microscopy, genetics, cellular biophysics, molecular biophysics, enzymes, nanofabrication, gold, silver, scanning electron microscopy, nanoparticles, Fourier transform infrared spectra, atomic force microscopy, biomedical materialsOther keywords: size 1.0 nm to 12.0 nm, Ag‐Au, anti‐proliferative assessment, eco‐friendly‐based method, anti‐proliferative activity, anti‐proliferative properties, biopolymer‐based Ag–Au bimetallic nanoparticle, Cochlospermum gossypium, gum kondagogu, biopolymer preparation, biogenic synthesis, UV‐absorption, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, MTT assay, confocal microscopy, flow cytometry, caspase‐3, caspase‐9, peroxisome proliferator‐activated receptors, Bcl‐2 gene, Bcl‐x(K) gene, B16F10 cells     

Antibacterial,anti‐inflammatory and antioxidant effects of acetyl‐11‐α‐keto‐β‐boswellic acid mediated silver nanoparticles in experimental murine mastitis

Mastitis is an important economic disease causing production losses in dairy industry. Antibiotics are becoming ineffective in controlling mastitis due to the emergence of resistant strains requiring the development of novel therapeutic agents. In this study, the authors present the phytochemical synthesis of silver nanoparticles (AgNPs) with acetyl‐11‐α‐keto‐β‐boswellic acid and evaluation of their activity in Staphylococcus aureus induced murine mastitis. Boswellic acid mediated AgNP (BANS) were oval, polydispersed (99.8 nm) with an minimum inhibitory concentration of 0.033 µg ml⁻¹ against S. aureus, inhibitory concentration (IC₅₀) of 30.04 µg ml⁻¹ on mouse splenocytes and safe at an in vivo acute oral dose of 3.5 mg kg⁻¹ in mice. Mastitis was induced in lactating mice by inoculating S. aureus (log₁₀ 5.60 cfu) and treated 6 h post‐inoculation with BANS (0.12 mg kg⁻¹, intramammary and intraperitoneal), and cefepime (1 mg kg⁻¹, intraperitoneal). S. aureus inoculated mice showed increased bacterial load, neutrophil infiltration in mammary glands and elevated C‐reactive protein (CRP) in serum. Oxidative stress was also observed with elevated malondialdehyde level, superoxide dismutase (SOD) and catalase (CAT) activities. BANS treatment significantly (P  < 0.05) reduced bacterial load, CRP, SOD, CAT activities and neutrophil infiltration in affected mammary glands. BANS could be a potential therapeutic agent for managing bovine mastitis.Inspec keywords: nanomedicine, nanoparticles, silver, antibacterial activity, drugs, diseases, enzymesOther keywords: antibacterial effects, antiinflammatory effects, antioxidant effects, acetyl‐11‐α‐keto‐β‐boswellic acid, mediated silver nanoparticles, experimental murine mastitis, economic disease, dairy industry, resistant strains, phytochemical synthesis, Staphylococcus aureus, minimum inhibitory concentration, inoculating S. aureus, neutrophil infiltration, mammary glands, elevated C‐reactive protein, superoxide dismutase, catalase, bovine mastitis, Ag     

Synthesis,characterisation and potential biomedical applications of magnetic core–shell structures: carbon‐, dextran‐, SiO2 ‐ and ZnO‐coated Fe3 O4 nanoparticles

Due to the strong effect of nanoparticles'' size and surface properties on cellular uptake and bio‐distribution, the selection of coating material for magnetic core–shell nanoparticles (CSNPs) is very important. In this study, the effects of four different biocompatible coating materials on the physical properties of Fe₃ O₄ (magnetite) nanoparticles (NPs) for different biomedical applications are investigated and compared. In this regard, magnetite NPs are prepared by a simple co‐precipitation method. Then, CSNPs including Fe₃ O₄ as a core and carbon, dextran, ZnO (zincite) and SiO₂ (silica) as different shells are synthesised using simple one‐ or two‐step methods. A comprehensive study is carried out on the prepared samples using X‐ray diffraction, vibrating sample magnetometry, transmission electron microscopy and Fourier transform infrared spectroscopy analyses. According to the authors'' findings, it is suggested that carbon‐ and dextran‐coated magnetite NPs with high M _s have great potential in the application of magnetic resonance imaging contrast agents. Moreover, silica‐coated magnetite NPs with high coercivity are potentially suitable candidates for hyperthermia and ZnO‐coated Fe₃ O₄ is potentially suitable for photothermal therapy.Inspec keywords: iron compounds, carbon, silicon compounds, zinc compounds, nanomedicine, biomedical materials, nanofabrication, nanoparticles, magnetic particles, coatings, X‐ray diffraction, magnetometry, transmission electron microscopy, Fourier transform spectra, infrared spectra, biomedical MRI, hyperthermia, radiation therapyOther keywords: biomedical applications, magnetic core‐shell nanoparticles, CSNP, cellular uptake, biodistribution, coating material, biocompatible coating materials, co‐precipitation, dextran, zincite, silica, X‐ray diffraction, vibrating sample magnetometry, transmission electron microscopy, Fourier transform infrared spectroscopy, magnetic resonance imaging contrast agents, hyperthermia, photothermal therapy, SiO₂ ‐Fe₃ O₄ , ZnO‐Fe₃ O₄      

Solving linear and non‐linear space–time fractional reaction–diffusion equations by the Adomian decomposition method

In this paper, we consider linear and non‐linear space–time fractional reaction–diffusion equations (STFRDE) on a finite domain. The equations are obtained from standard reaction–diffusion equations by replacing a second‐order space derivative by a fractional derivative of order β∈(1, 2], and a first‐order time derivative by a fractional derivative of order α∈(0, 1]. We use the Adomian decomposition method to construct explicit solutions of the linear and non‐linear STFRDE. Finally, some examples are given. Copyright © 2007 John Wiley & Sons, Ltd.     

Effect of GNP functionalisation and multiple N ‐methylation of β ‐amyloid residue (32–37) on Gram‐positive bacterium

In the previous report, the authors showed the gold nanoparticle (GNP) functionalised multiple N ‐methylated fragments of the residue (32–37) of beta (β)‐amyloid protein (1–42), CGGIGLMVG and CGGGGGIGLMVG toward disruption of β ‐amyloid (1–42), the predominant component of senile plaques. Herein the in vitro antimicrobial activities of both normal and multiple N ‐methylated sequences of CGGIGLMVG and CGGGGGIGLMVG were screened and it was found that all the eight sequences including four (non‐functionalised with GNP) to possess activity against both Gram‐positive [Staphylococcus aureus (ATCC 43300) and Enterococcus faecalis (ATCC 5129)] and Gram‐negative [Escherichia coli (ATCC 35218), Pseudomonas aeruginosa (ATCC 27853) and Klebsiella pneumoniae (ATCC 700603)] bacteria. Among them, N ‐methylated sequences CGGIGLMVG and CGGGGGIGLMVG shown remarkable activity against Gram‐positive bacteria.Inspec keywords: microorganisms, gold, nanoparticles, nanomedicineOther keywords: GNP functionalisation, N‐methylation, β‐amyloid residue, Gram‐positive bacterium, gold nanoparticle functionalised multiple N‐methylated fragments, beta β‐amyloid protein, CGGGGGIGLMVG, Staphylococcus aureus, ATCC 43300, Enterococcus faecalis, ATCC 5129, Escherichia coli, ATCC 35218, Pseudomonas aeruginosa, ATCC 27853, Klebsiella pneumoniae, ATCC 700603, Au     

Green synthesised iron and iron‐based nanoparticle in environmental and biomedical application: – a review

Owing to the development of nanotechnology and its influence in various fields, the development of efficient and environmental friendly technique for the synthesis of nanomaterials is important. Among the various traditional and conventional methods available for the synthesis, plant‐mediated synthesis seems to be a very attractive and environmental friendly method, attributing to its simple methodology and eco‐friendly approach. The synthesis rate and stability of the nanoparticle synthesised are good when compared to the other methods of synthesis and it is proved to be efficient in various fields of application. Hence, the present review article deals with furnishing information about the plant sources used so far and details about the environmental and biomedical applications of the synthesised nanoparticles.Inspec keywords: nanoparticles, reviews, nanomedicine, nanofabrication, antibacterial activity, ironOther keywords: environmental application, biomedical application, iron‐based nanoparticle, environmental friendly technique, traditional methods, plant‐mediated synthesis, environmental friendly method, simple methodology, eco‐friendly approach, synthesis rate, nanoparticle stability, green synthesis, nanotechnology, nanomaterials, conventional methods, Fe     

Accuracy of the Maxwell–Wagner and the Bruggeman–Hanai mixture models for single cell dielectric spectroscopy

Dielectric spectroscopy (DS) is a non‐invasive, label‐free, and promising technique for measuring dielectric properties of biological cells. Recent developments in microfabrication techniques made it possible to perform DS measurements with minute volume of cell suspensions. However, when the cell size approaches the size of the measurement chamber, especially, for single cell measurements, the analytical models [Maxwell–Wagner and Bruggeman–Hanai (BH) mixture models] to extract cell parameters lose their accuracy. Moreover, variations in the cell position relative to the measurement electrodes decrease the accuracy of the analytical solutions. Impedance spectrum of a typical eukaryotic mammalian cell is generated for different geometrical configurations using finite element. The generated data are fitted to the analytical models and extracted cell parameters are compared with the original values. The results show that BH model works more effectively when chamber to cell radius ratio is <3.5 and chamber height to cell radius ratio is <3. Moreover, it is observed that analytical models estimate cell parameters with major errors when the cells are in the vicinity of the electrodes. However, for high‐volume fraction simulations, the BH model was able to predict cell parameters better even in the vicinity of the electrodes.Inspec keywords: cellular biophysics, bioelectric phenomena, dielectric properties, finite element analysis, biomedical measurement, biomedical electrodesOther keywords: Maxwell‐Wagner mixture model, Bruggeman‐Hanai mixture model, single cell dielectric spectroscopy, noninvasive label‐free technique, dielectric properties, biological cells, microfabrication techniques, cell suspensions, cell size, single cell measurements, cell position, measurement electrodes, impedance spectrum, eukaryotic mammalian cell, geometrical configurations, finite element, cell parameters, high‐volume fraction simulations, electrodes     

RYR2 mutation in non‐small cell lung cancer prolongs survival via down‐regulation of DKK1 and up‐regulation of GS1‐115G20.1: A weighted gene Co‐expression network analysis and risk prognostic models

RYR2 mutation is clinically frequent in non‐small cell lung cancer (NSCLC) with its function being elusive. We downloaded lung squamous cell carcinoma and lung adenocarcinoma samples from the TCGA database, split the samples into RYR2 mutant group (n = 337) and RYR2 wild group (n = 634), and established Kaplan‐Meier curves. The results showed that RYR2 mutant group lived longer than the wild group (p = 0.027). Weighted gene co‐expression network analysis (WGCNA) of differentially expressed genes (DEGs) yielded prognosis‐related genes. Five mRNAs and 10 lncRNAs were selected to build survival prognostic models with other clinical features. The AUCs of 2 models are 0.622 and 0.565 for predicting survival at 3 years. Among these genes, the AUCs of DKK1 and GS1‐115G20.1 expression levels were 0.607 and 0.560, respectively, which predicted the 3‐year survival rate of NSCLC sufferers. GSEA identified an association of high DKK1 expression with TP53, MTOR, and VEGF expression. Several target miRNAs interacting with GS1‐115G20.1 were observed to show the relationship with the phenotype, treatment, and survival of NSCLC. NSCLC patients with RYR2 mutation may obtain better prognosis by down‐regulating DKK1 and up‐regulating GS1‐115G20.1.