Lagenaria siceraria – synthesised ZnO NPs – a valuable green route to control the malaria vector Anopheles stephensi

Malaria is a dangerous disease affecting humans and animals in tropical and subtropical areas worldwide. According to recent estimates, 3.2 billion people are at risk of malaria. Many drugs are in practices to control this disease and their vectors. Eco‐friendly control tools are needed to fight vectors of this important disease. Nanotechnology is playing a key role in the fight against many public health emergencies. In the present study, Lagenaria siceraria aqueous peel extract was used to prepare zinc oxide nanoparticles (ZnO NPs), then tested on Anopheles stephensi eggs, larvae and pupae. The L. siceraria ‐synthesised ZnO NPs were characterized additionally by FTIR, AFM, XRD, UV‐Vis spectroscopy, EDX, and SEM spectroscopy The ovicidal, larvicidal, pupicidal and repellent activities of L. siceraria and green‐synthesised ZnO NPs were analysed on A. stephensi. The potential mechanism of action of ZnO NPs was studied investigating the changes in various enzyme activities in A. stephensi IV instar larvae. Furthermore, the smoke toxicity of L. siceraria ‐based cones against A. stephensi evoked higher mortality if compared with the control. Overall, the present study concluded that L. siceraria peel extract and its mediated green synthesised ZnO NPs represent a valuable green option to manage against malaria vectors.Inspec keywords: X‐ray diffraction, Fourier transform spectra, nanomedicine, silver, enzymes, zinc compounds, nanotechnology, nanoparticles, diseases, pest control, transmission electron microscopy, pharmaceutical technology, health hazardsOther keywords: ZnO, nanotechnology, drugs, diseases, siceraria peel, scanning electron microscope spectroscopy, Fourier‐transform infrared spectroscopy, anopheles stephensi, malaria vector, lagenaria siceraria     

In vitro evaluation of antimicrobial and antibiofilm potentials of silver nanoparticles biosynthesised by Streptomyces griseorubens

This study was performed to determine the antimicrobial and antibiofilm activities of silver nanoparticles (AgNPs) biosynthesised using Streptomyces griseorubens AU2 isolated from soil. The antimicrobial activity of the AgNPs was determined by agar well diffusion, disc diffusion and broth microdilution methods. Diameters of the zone of inhibition results clearly displayed that the microbially biosynthesised AgNPs have potent antimicrobial activity against Candida albicans, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) of the nanoparticles that had been determined by broth microdilution method were found to be 20 and 50 µg/ml for C. albicans, B. subtilis and S. aureus; 10 and 20 µg/ml for E. coli and P. aeruginosa, respectively. For determining the effect of AgNPs on biofilm formation under in vitro conditions, MIC and subMICs were studied on P. aeruginosa and S. aureus biofilms by using microplate biofilm assay. Treatment of the AgNPs resulted in a decrease in the biofilm formation of S. aureus and P. aeruginosa as 26.52 and 25.50%, respectively. As a result of this study, it can be suggested that actinobacterially synthesised AgNPs have an effective potential to be used for pharmaceutical applications against multi‐resistant microorganisms.Inspec keywords: silver, nanoparticles, nanomedicine, antibacterial activity, biomedical materials, microorganismsOther keywords: antimicrobial potentials, antibiofilm potentials, silver nanoparticles, antimicrobial activity, antibiofilm activity, Streptomyces griseorubens AU2, disc diffusion, microdilution method, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, nanoparticle minimum inhibitory concentration, nanoparticle minimum lethal concentration, biofilm formation, in vitro conditions, microplate biofilm assay, pharmaceutical applications, multiresistant microorganisms, Ag     

Assessment of cytotoxicity and immune compatibility of phytochemicals‐mediated biosynthesised silver nanoparticles using Cynara scolymus

The study was focused on the phytochemicals‐mediated biosynthesis of silver nanoparticles using leaf extracts and infusions from Cynara scolymus. To identify the antioxidant activity and total phenolic content, the 1,1‐diphenyl‐1‐picrylhydrazyl and Folin–Ciocalteau methods were applied, respectively. The formation and stability of the reduced silver ions were monitored by UV–vis spectrophotometer. The particle sizes of the silver nanoparticles were characterised using the dynamic light scattering technique and scanning electron microscope. The phase composition of the obtained silver nanoparticles was characterised by X‐ray diffraction. The silver nanoparticles suspension, artichoke infusion, and silver ions were separately tested towards potential cytotoxicity and pro‐inflammatory effect using mouse fibroblasts and human monocytes cell line, respectively. The total phenolic content and antioxidant activity of ethanol extract and infusion were found significantly higher as compared to aqueous extract and infusion. The UV–visible spectrophotometric analysis revealed the presence of the characteristic absorption band of the Ag nanoparticles. Moreover, it was found that with the increasing volume of plant extract, the average size of particles was increased. Biocompatibility results evidently showed that silver nanoparticles do not induce monocyte activation, however in order to avoid their cytotoxicity suspension at a concentration <2 ppm should be applied.Inspec keywords: pharmaceuticals, health and safety, renewable materials, toxicology, organic compounds, antibacterial activity, X‐ray diffraction, nanomedicine, nanoparticles, nanofabrication, suspensions, ultraviolet spectra, visible spectra, scanning electron microscopy, silver, particle sizeOther keywords: phytochemicals‐mediated biosynthesis, antioxidant activity, total phenolic content, dynamic light scattering technique, silver nanoparticles suspension, scanning electron microscopy, Cynara scolymus, 1,1 diphenyl‐1‐picrylhydrazyl method, cytotoxicity, immune compatibility, leaf extracts, UV‐vis spectrophotometry, particle size, Folin‐Ciocalteau methods, phase composition, X‐ray diffraction, artichoke infusion, pro‐inflammatory effect, mouse fibroblasts, human monocytes cell line, Ag     

Enhanced wound healing activity of Ag–ZnO composite NPs in Wistar Albino rats

In the present study, silver (Ag) and Ag–zinc oxide (ZnO) composite nanoparticles (NPs) were synthesised and studied their wound‐healing efficacy on rat model. Ultraviolet–visible spectroscopy of AgNPs displayed an intense surface plasmon (SP) resonance absorption at 450 nm. After the addition of aqueous Zn acetate solution, SP resonance band has shown at 413.2 nm indicating a distinct blue shift of about 37 nm. X‐ray diffraction analysis Ag–ZnO composite NPs displayed existence of two mixed sets of diffraction peaks, i.e. both Ag and ZnO, whereas AgNPs exhibited face‐centred cubic structures of metallic Ag. Scanning electron microscope (EM) and transmission EM analyses of Ag–ZnO composite NPs revealed the morphology to be monodispersed hexagonal and quasi‐hexagonal NPs with distribution of particle size of 20–40 nm. Furthermore, the authors investigated the wound‐healing properties of Ag–ZnO composite NPs in an animal model and found that rapid healing within 10 days when compared with pure AgNPs and standard drug dermazin.Inspec keywords: wounds, tissue engineering, biomedical materials, nanocomposites, nanofabrication, nanomedicine, silver, zinc compounds, II‐VI semiconductors, wide band gap semiconductors, ultraviolet spectra, visible spectra, nanoparticles, particle size, surface plasmon resonance, spectral line shift, X‐ray diffraction, scanning electron microscopy, transmission electron microscopyOther keywords: enhanced wound healing activity, Ag‐ZnO composite nanoparticles, Wistar Albino rats, wound‐healing efficacy, ultraviolet‐visible spectroscopy, intense surface plasmon resonance absorption, aqueous Zn acetate solution, SP resonance band, blue shift, X‐ray diffraction analysis, diffraction peaks, face‐centred cubic structures, scanning electron microscope, SEM, transmission electron microscope, TEM, monodispersed hexagonal nanoparticles, quasihexagonal nanoparticles, particle size, animal model, time 10 d, size 20 nm to 40 nm, Ag‐ZnO     

Diospyros assimilis root extract assisted biosynthesised silver nanoparticles and their evaluation of antimicrobial activity

The current research study focuses on biosynthesis of silver nanoparticles (Ag NPs) for the first time from silver acetate employing methanolic root extract of Diospyros assimilis. The UV–Vis absorption spectrum of biologically synthesised nanoparticles displayed a surface plasmon peak at 428 nm indicating the formation of Ag NPs. The influence of metal ion concentration, reaction time and amount of root extract in forming Ag NPs by microscopic and spectral analysis was thoroughly investigated. Structural analysis from transmission electron microscopy confirmed the nature of metallic silver as face‐centered cubic (FCC) crystalline with an average diameter of 17 nm, which correlates with an average crystallite size (19 nm) calculated from X‐ray diffraction analysis. Further, the work was extended for the preliminary examination of antimicrobial activity of biologically synthesised Ag NPs that displayed promising activity against all the tested pathogenic strains.Inspec keywords: antibacterial activity, nanoparticles, silver, particle size, nanofabrication, nanomedicine, biomedical materials, ultraviolet spectra, visible spectra, optical microscopy, surface plasmon resonance, transmission electron microscopy, crystallites, X‐ray diffraction, microorganismsOther keywords: Diospyros assimilis root extract assisted biosynthesised silver nanoparticles, antimicrobial activity, silver acetate, methanolic root extract, UV‐visible absorption spectrum, biologically synthesised nanoparticles, surface plasmon peak, Ag NPs formation, metal ion concentration, reaction time, microscopic analysis, spectral analysis, structural analysis, transmission electron microscopy, metallic silver, FCC crystalline phase, average crystallite size, X‐ray diffraction analysis, pathogenic strains, Ag     

Cytotoxicity,leishmanicidal, and antioxidant activity of biosynthesised zinc sulphide nanoparticles using Phoenix dactylifera

The synthesis of zinc sulphide nanoparticles (ZnS NPs) using a green approach was explored. The resulting nanoparticles (NPs) were characterised by UV–vis spectroscopy, scanning and transmission electron microscopy, X‐ray diffraction and Fourier transform infrared spectroscopy. The leishmanicidal, cytotoxic and antioxidant activity of the resulting synthesised ZnS NPs (<70 nm) were evaluated against Leishmania major (L. major) promastigotes and amastigotes by MTT assay and using a macrophage model. The ZnS NPs were able to counteract the effects of oxidative metabolites as demonstrated by the oxidant activity. The IC₅₀ value of butylated hydroxyanisole was 26.04 µg/ml as compared with the IC₅₀ for ZnS NPs (90.95 µg/ml). The NPs displayed no cytotoxicity for the murine macrophaghes as the selectivity index (SI) fell into the safety range (SI ≥ 10). These nanomaterials exhibited good antileishmanial activity against the L. major stages that were comparable to that of Glucantime, the drug of choice. The IC₅₀ values of ZnS NPs and Glucantime against amastigotes were 11.59 ± 2.51 and 4.95 ± 2.51 μg/ml, respectively. The IC₅₀ values for ZnS NPs and Glucantime versus promastigote were 29.81 ± 3.15 and 14.75 ± 4.05 μg/ml, respectively. Further investigation is essential to explore the biological effects of ZnS NPs on animal and/or clinical models.Inspec keywords: nanoparticles, nanofabrication, microorganisms, antibacterial activity, ultraviolet spectra, visible spectra, nanobiotechnology, X‐ray diffraction, Fourier transform infrared spectra, zinc compoundsOther keywords: cytotoxicity, leishmanicidal activity, antioxidant activity, biosynthesised zinc sulphide nanoparticles, Phoenix dactylifera, green approach, UV–vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, Leishmania major promastigotes, Leishmania major amastigotes, MTT assay, macrophage model, oxidative metabolites, butylated hydroxyanisole, murine macrophaghes, selectivity index, glucantime, ZnS     

In vitro germination and biochemical profiling of Brassica napus in response to biosynthesised zinc nanoparticles

With the progression of nanotechnology, the use of nanoparticles (NPs) in consumer products has increased dramatically and green synthesis is one of the cheapest and eco‐friendly methods to obtain non‐hazardous NPs. In the current research zinc (Zn) NPs synthesis was carried out by using the fresh and healthy leaves of Mentha arvensis L. followed by characterisation through ultraviolet (UV)–visible spectroscopy, X‐ray diffraction (XRD) and scanning electron microscopy (SEM). UV–visible spectroscopy confirmed the green synthesis of ZnNPs, while XRD confirmed the size of NPs, which was 30–70 nm. SEM shows that the shape of ZnNPs was irregular. The effects of green synthesised NPs on two different varieties of Brassica napus were evaluated. Exposure to ZnNPs (5, 15, and 25 mg/l⁻¹) caused a significant increase in root and shoot length of B. napus. The application of NPs significantly improved plant germination and triggered the production of secondary metabolite and antioxidant enzymes. ZnNPs showed a significant increase in chlorophyll, superoxide dismutase, total flavonoid content (TFC) and antioxidant enzymes while total phenolic content was decreased when TFC increased. Thus, it has been concluded from the current study that ZnNPs may possibly trigger the production of antioxidant enzymes and various biochemical compounds.Inspec keywords: zinc, nanoparticles, nanofabrication, ultraviolet spectra, visible spectra, X‐ray diffraction, scanning electron microscopy, particle size, enzymes, molecular biophysics, biochemistry, nanobiotechnology, botanyOther keywords: biochemical profiling, Brassica napus, biosynthesised zinc nanoparticles, nanotechnology, Mentha arvensis L, ultraviolet‐visible spectroscopy, X‐ray diffraction, Zn, biochemical compounds, total phenolic content, total flavonoid content, superoxide dismutase, chlorophyll, antioxidant enzymes, secondary metabolite, plant germination, green synthesis, SEM, scanning electron microscopy, XRD     

Influence of Mn impurity on formation of secondary phases and optical properties of ZnO NPs

ZnO:Mn nanoparticles with various Mn concentrations (1–7%) were synthesized by a simple chemical method at low temperature. Structural and optical properties of as synthesized samples were investigated by X-ray diffraction (XRD), UV–vis absorbance, and photoluminescence (PL) spectrophotometers, respectively. XRD patterns of the ZnO:Mn nanocrystals indicate that in low Mn concentrations (1 and 3%), the ZnMn₂O₄ nanoparticles are formed, whereas in high Mn concentrations (5 and 7%), more Mn atoms replace Zn atoms in crystalline lattice, so that Mn₃O₄ is formed. It is also found that the size of the ZnO:Mn nanocrystals increases from 7.82 to 76.07?nm with increasing Mn concentration from 1 to 7%. Band gap energy of the samples, calculated by extrapolation of (αhν)² versus hν curves, shows a decrease in band gap with increasing the Mn concentration from 1 to 7%. The size of nanoparticles calculated by effective mass approximation model is nearly in accordance with the one calculated by Scherrer formula. The PL spectra of low Mn concentration ZnO:Mn nanoparticles indicate a weak green emission which vanishes in highly Mn concentrated ZnO:Mn samples.     

Facile synthesis and characterization of ZnO NPs,ZnO/CdO and ZnO/SnO2 nanocomposites for photocatalytic degradation of Eosin Yellow and Direct Blue 15 under UV light irradiation

Journal of Materials Science: Materials in Electronics - In the present report, the synthesis of ZnO NPs, ZnO/CdO NCs, and ZnO/SnO2 NCs was successfully achieved by co-precipitation technique. The...     

Analytical study of biosynthesised silver nanoparticles against multi‐drug resistant biofilm‐forming pathogens

The emergence of the huge number of multi‐drug resistant (MDR) bacteria requires an alternative to the drugs. Silver nanoparticles (AgNPs) are a strong candidate for this due to their bactericidal properties, which can be better concluded by understanding their morphology and chemistry. The study hypothesised that AgNPs synthesised using leaves of Syzygium cumini can be used to treat locally emerging MDRs forming biofilms on indwelling medical devices. Synthesised particles were characterised by methods like UV–visible spectroscopy, X‐ray powder diffraction, scanning electron microscopy, transmission electron microscopy, and Zetasizer. Fourier transform infrared spectroscopy, and high‐performance liquid chromatography were used to predict phytochemicals present in the leaves. The shape of particles is revealed to be relatively spherical, with average size to be around 10–100 nm. Phenolic compounds are attributed to the formation of nanoparticles, stability analysis shows particles to be stable, and zeta potential determined the surface charge to be −20.1 mV. Biosynthesised particles are found to possess efficient antibacterial activity MDR bacteria developing biofilms in medical devices; hence, it is concluded that S. cumini based NPs can be used to develop a layer on implant‐related medical devices. Toxicity evaluation against A594 cancer cells portrays AgNPs to be potential tumour reduction agents in a concentration‐dependent manner.Inspec keywords: silver, visible spectra, X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, chromatography, electrokinetic effects, cancer, biomedical materials, reduction (chemical), cellular biophysics, nanofabrication, nanoparticles, antibacterial activity, particle size, drugs, toxicology, nanomedicine, ultraviolet spectra, microorganisms, tumours, Fourier transform infrared spectraOther keywords: Syzygium cumini, biofilms, indwelling medical devices, UV‐visible spectroscopy, X‐ray powder diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, high‐performance liquid chromatography, biosynthesised particles, implant‐related medical devices, biosynthesised silver nanoparticles, multidrug resistant biofilm‐forming pathogens, multidrug resistant bacteria, MDR, bactericidal properties, morphology, scanning electron microscopy, s. cumini based NP, A594 cancer cells, tumour reduction, Ag     

5 Fluorouracil‐loaded biosynthesised gold nanoparticles for the in vitro treatment of human pancreatic cancer cell

In this study, green synthesis of gold nanoparticles (AuNPs) was performed by a sunlight irradiation method using the Borassus flabellifer fruit extract as a reducing agent. 5‐Fluorouracil (5‐FU)‐loaded GG capped AuNPs (5FU‐G‐AuNPs) was prepared. The nanoparticles was further characterised by UV‐visible spectra, particle size analysis, zeta potential, SAED, HRTEM, and XRD. The MTT assay results showed the suitability 5‐FU‐G‐AuNPs. In this study, 5‐FU‐G‐AuNPs exhibited potential cytotoxic and apoptotic effects on (MiaPaCa‐2) cell line.Inspec keywords: gold, biochemistry, X‐ray diffraction, nanofabrication, biomedical materials, transmission electron microscopy, toxicology, electrokinetic effects, particle size, nanoparticles, cancer, visible spectra, cellular biophysics, ultraviolet spectra, nanomedicine, patient treatment, organic compoundsOther keywords: 5FU‐G‐AuNPs, suitability 5‐FU‐G‐AuNPs, human pancreatic cancer cell, green synthesis, sunlight irradiation method, 5‐Fluorouracil‐loaded GG, in vitro treatment, 5 fluorouracil‐loaded biosynthesised gold nanoparticles, borassus flabellifer fruit extract, reducing agent, UV‐visible spectra, particle size analysis, zeta potential, SAED, HRTEM, XRD, MTT assay, apoptotic effects, cytotoxic effects, MiaPaCa‐2 cell line, Au     

Assessment of acaricidal activity of nanoscale ZnO encapsulated piperine formulation against Rhipicephalus microplus

This study aims to synthesise and evaluate the acaricidal activity of nanoscale zinc oxide piperine formulation (NZPF) against Rhipicephalus microplus ticks. NZPF was prepared by using zinc oxide nanoparticles (ZnONPs) and piperine by employing encapsulation technique; characterised by UV spectroscopy, Fourier transformed infrared analysis, X‐ray diffraction, dynamic light scattering, zetapotential and scanning electron microscopy. Acaricidal activity of the NZPF on R. microplus was evaluated using larval packet test (LPT) and adult immersion test (AIT). LPT against R. microplus larvae showed an LC₅₀ at 1 mg/l for NZPF followed by 2 and 3 mg/l for ZnONPs and piperine, respectively. AIT against R. microplus showed an LC₅₀ at concentration of 3 mg/l for NZPF followed by 6 mg/l for ZnONPs and 7 mg/l for piperine. In both LPT and AIT, LC₅₀ values of ZnONPs and NZPF were significantly lower compared to deltamethrin. NZPF showed significant ovulation inhibitory activity with lower IC₅₀ and IC₉₉ values compared to ZnONPs and piperine. NZPF has been proved to be the better alternative to routine chemical acaricides for control of tick infestation of cattle in the wake of acaricidal resistance, but safety issues need to be addressed before clinical application.Inspec keywords: molecular biophysics, pest control, ultraviolet spectra, X‐ray diffraction, zinc compounds, scanning electron microscopy, nanomedicine, agricultural engineering, agricultural safety, nanoparticles, light scattering, electrokinetic effects, encapsulation, Fourier transform infrared spectra, biotechnologyOther keywords: acaricidal activity, nanoscale zinc oxide piperine formulation, NZPF, Rhipicephalus microplus ticks, zinc oxide nanoparticles, ZnONP, LPT, adult immersion test, AIT, larval packet test, acaricidal resistance, UV spectroscopy, Fourier transformed infrared analysis, X‐ray diffraction, dynamic light scattering, zetapotential, scanning electron microscopy, ZnO     

In situ detection of the Zn2+ release process of ZnO NPs in tumour cells by confocal laser scanning fluorescence microscopy

The use of zinc oxide (ZnO) nanoparticles (NPs) for cancer is not yet clear for human clinical applications, which is primarily due to the lack of a better understanding of the action mechanisms and cellular consequences of the direct exposure of cells to these NPs. In this work, the authors have selected zinquin ethyl ester, a Zn²⁺ ‐specific fluorescent molecular probe, to efficiently differentiate ZnO NPs and Zn²⁺, and combined with confocal laser scanning microscopy (CLSM) to in situ study the Zn²⁺ release process of ZnO NPs in cancer cell system through detecting the change of Zn²⁺ level over time. During the experiments, the authors have designed the test group ZnO‐2 in addition to assess the influence of a long‐term storage on the characteristics of ZnO NPs in aqueous solution, and the Zn²⁺ release process of ZnO NPs in cancer cell system. After three‐month storage at room temperature, the release process became earlier and faster, which was consistent with previous results of transmission electron microscope, UV‐Vis and PL spectra. It is a good detection method that combination of Zn²⁺ ‐specific fluorescent molecular probe and CLSM, which will be helpful for ZnO NPs using in clinical research.Inspec keywords: cancer, cellular biophysics, fluorescence, laser applications in medicine, molecular biophysics, nanomedicine, nanoparticles, optical microscopy, positive ions, tumours, zinc, zinc compoundsOther keywords: zinc oxide nanoparticles, tumour cells, confocal laser scanning fluorescence microscopy, zinquin ethyl ester, zinc‐specific fluorescent molecular probe, cancer cell system, aqueous solution, room temperature, transmission electron microscope, ultraviolet‐visible spectra, photoluminescence spectra, time 3 month, temperature 293 K to 298 K, ZnO, Zn²⁺      

Nitrobacter sp. extract mediated biosynthesis of Ag2 O NPs with excellent antioxidant and antibacterial potential for biomedical application

In this study, extracellular extract of plant growth promoting bacterium, Nitrobacter sp. is used for the bioconversion of AgNO₃ (silver nitrate) into Ag₂ O (silver oxide nanoparticles). It is an easy, ecofriendly and single step method for Ag₂ O NPs synthesis. The bio‐synthesized nanoparticles were characterized using different techniques. UV‐Vis results showed the maximum absorbance around 450 nm. XRD result shows the particles to have faced centered cubic (fcc) crystalline nature. FTIR analysis reveals the functional groups that are involved in bioconversion such as C–N, N–H and C=O. Energy‐dispersive X‐ray spectroscopy (EDAX) spectrum confirms that the prepared nanoparticle is Ag₂ O NPs. Particle size distribution result reveals that the average particle size is around 40 nm. The synthesized Ag₂ O NPs found to be almost spherical in shape. Biosynthesized Ag₂ O NPs possess good antibacterial activity against selected Gram positive and Gram negative bacterial strains namely Salmonella typhimurium, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae when compared to standard antibiotic. In addition, Ag₂ O NPs exhibits excellent free radical scavenging activity with respect to dosage. Thus, this study is a new approach to use soil bacterial extract for the production of Ag₂ O NPs for biomedical application.Inspec keywords: nanomedicine, nanoparticles, silver compounds, antibacterial activity, ultraviolet spectra, visible spectra, X‐ray diffraction, Fourier transform infrared spectra, X‐ray chemical analysis, particle size, free radicalsOther keywords: free radical scavenging activity, Ag₂ O, AgNO₃ , Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Gram negative bacterial strains, Gram positive bacterial strains, particle size distribution, energy‐dispersive X‐ray spectroscopy spectrum, functional groups, Fourier transform infrared analysis, faced centred cubic crystalline nature, XRD, UV‐Vis results, bio‐synthesised nanoparticles, silver oxide nanoparticles, silver nitrate bioconversion, plant growth promoting bacterium, extracellular extract, biomedical application, antibacterial potential, antioxidant potential, Ag₂ O NPs, extract mediated biosynthesis, Nitrobacter sp     

Petri Net modelling approach for analysing the behaviour of Wnt/ β ‐catenin and Wnt/ Ca2+ signalling pathways in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disease that may result in arrhythmia, heart failure and sudden death. The hallmark pathological findings are progressive myocyte loss and fibro fatty replacement, with a predilection for the right ventricle. This study focuses on the adipose tissue formation in cardiomyocyte by considering the signal transduction pathways including Wnt/ β ‐catenin and Wnt/Ca²⁺ regulation system. These pathways are modelled and analysed using stochastic petri nets (SPN) in order to increase our comprehension of ARVC and in turn its treatment regimen. The Wnt/ β ‐catenin model predicts that the dysregulation or absence of Wnt signalling, inhibition of dishevelled and elevation of glycogen synthase kinase 3 along with casein kinase I are key cytotoxic events resulting in apoptosis. Moreover, the Wnt/Ca²⁺ SPN model demonstrates that the Bcl2 gene inhibited by c‐Jun N‐terminal kinase protein in the event of endoplasmic reticulum stress due to action potential and increased amount of intracellular Ca²⁺ which recovers the Ca²⁺ homeostasis by phospholipase C, this event positively regulates the Bcl2 to suppress the mitochondrial apoptosis which causes ARVC.Inspec keywords: molecular biophysics, enzymes, cancer, muscle, Petri nets, cellular biophysics, bioelectric potentials, biomembranes, tumours, cardiology, genetics, biochemistry, calciumOther keywords: heart failure, sudden death, hallmark pathological findings, progressive myocyte loss, fibro fatty replacement, adipose tissue formation, signal transduction pathways, Ca²⁺ regulation system, stochastic petri nets, ARVC, $β‐catenin model, Wnt signalling, glycogen synthase kinase 3, Bcl2 gene, c‐Jun N‐terminal kinase protein, petri Net modelling approach, Ca²⁺ signalling pathways, arrhythmogenic right ventricular cardiomyopathy, inherited heart muscle disease, Ca²⁺ SPN model, Ca     

Calibration of ultrahigh vacuum gauge from 10 Pa to 10 Pa by the two-stage flow-dividing system

A new two-stage flow-dividing system has been developed for the calibration of ultrahigh vacuum gauges from 10⁻⁹ Pa to 10⁻⁵ Pa for N₂, Ar, and H₂. This system is designed based on the techniques for our previously developed calibration system in the range from 10⁻⁷ Pa to 10⁻² Pa. Three modifications were performed to extend the calibration pressure to a lower range. The relative standard uncertainty of the generated pressure (k = 1) is in the range from 2.3% to 2.6%, from 10⁻⁹ Pa to 10⁻⁵ Pa. The characteristics of ultrahigh vacuum gauges were also examined by using this system. The stabilities of the pressure reading, the linearity, the temperature dependence, and the long-term stability were examined. These results show that the calibration of ultrahigh vacuum gauges is possible in the range from 10⁻⁹ Pa to 10⁻⁵ Pa for N₂, Ar, and H₂ with the uncertainty of about 6.0% (k = 2) by this new system.     

Biofabrication of nanogold from the flower extracts of Lantana camara

The present investigation was done to explore the potential of Lantana camara (L. camara) flower in the fabrication of gold nanoparticles (AuNPs). The shape and size of AuNPs have been successfully controlled by introducing small amounts of L. camara flower extract. It produced spherical nanogold of average size 10.6 ± 2.9 nm without any aggregation and showed significant photocatalytic degradation activity of the methylene blue (>62%, 10 mg/L) in the presence of solar light. In addition, the experimental approach is inexpensive, rapid and eco‐friendly for industrial scale production of nanoparticles.Inspec keywords: nanoparticles, gold, nanofabrication, botany, catalysis, photochemistry, organic compoundsOther keywords: biofabrication, Lantana camara flower extract, gold nanoparticles fabrication, spherical nanogold, photocatalytic degradation activity, methylene blue, solar light, size 10.6 nm to 2.9 nm, Au