Biomimetic synthesis of AgNPs from Penicillium chrysogenum strain FGCC/BLS1 by optimising physico‐cultural conditions and assessment of their antimicrobial potential

Biomimetic synthesis of metal nanoparticles (NPs) is safe and eco‐friendly; therefore, find diverse applications. Considering this, the soil fungi Penicillium chrysogenum strain Fungal germplasm collection centre/ BLS1 was isolated, characterized and explored to synthesize extracellular silver NPs (AgNPs) under optimised conditions. The synthesis of AgNPs was investigated using ultraviolet (UV)–visible spectroscopy, Fourier‐transform infra‐red spectroscopy (FTIR), transmission electron microscope (TEM) and dynamic light scattering (DLS) analysis. Process optimisation exhibited AgNPs synthesis within 8 h using 2 mM AgNO3 at pH 11 and temperature 70°C. TEM analysis revealed polydispersed ellipsoidal shaped AgNPs with average particle size 96.8 nm as measured by DLS. AgNPs showed negative zeta potential that confers surface stability in solution. FTIR spectra confirmed the presence of protein bound to AgNPs. Antibacterial activity against Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus by the AgNPs (100 ppm) was demonstrated by counting colony forming unit, disc diffusion, and growth kinetics assay. Additionally radial assay revealed antifungal activity of AgNPs (100 ppm) against phytopathogenic fungi Sclerotinia sclerotiorum Microbial type culture collection 8785. Furthermore, AgNPs (100 ppm) did not show any cytotoxic effects on human Red blood cells. Therefore, this novel fungal strain can be utilised for biofabrication of AgNPs under optimised conditions and have shown strong antimicrobial property.Inspec keywords: biomimetics, silver, nanoparticles, particle size, nanofabrication, nanomedicine, microorganisms, biomedical materials, antibacterial activity, light scattering, cellular biophysics, ultraviolet spectra, visible spectra, Fourier transform infrared spectra, transmission electron microscopy, pH, electrokinetic effects, proteins, molecular biophysics, biochemistry, reduction (chemical), biodiffusion, reaction kinetics, bloodOther keywords: biomimetic synthesis, physicocultural conditions, antimicrobial potential assessment, metal nanoparticles, soil fungi Penicillium chrysogenum strain FGCC/BLS1, extracellular silver NPs, ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy, FTIR, transmission electron microscope, TEM, dynamic light scattering, process optimisation, Ag nitrate, pH, absorbance, polydispersed ellipsoidal shaped AgNPs, particle size, DLS, mycosynthesised AgNPs, negative zeta potential, surface stability, protein component, reducing agent, antibacterial activity, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, disc diffusion, colony forming unit counting, growth kinetics assay, radial assay, antifungal activity, phytopathogenic fungi Sclerotinia sclerotiorum MTCC 8785, RBC haemolysis assay, temperature 70 degC, Ag     

Smart object recommendation (SORec) architecture using representation learning in Smart objects-Based Social Network (SBSN)

The Journal of Supercomputing - With the popularization of Internet of Things (IoT) and Social Internet of Things (SIoT), innumerable smart objects are allowed to establish associations among each...     

A system dynamics framework for integrated reverse supply chain with three way recovery and product exchange policy

With the technological advancements and rapid changes in demand pattern, diverse ranges of products are entering into the market with reduced lifecycle which leads to the environmental disasters. The awareness of product take-back and recovery has been increasing in various supply chains not only due to the obligation imposed by legislation but also competitive economics worldwide. In this paper, we develop a system dynamics framework for a closed-loop supply chain network with product exchange and three way recovery policy, namely; product remanufacturing, component reuse and remanufacturing, and raw material recovery. In the simulation study, we investigate the significance of various factors including product exchange, collection and remanufacturing; their interactions and the type of their impact on bullwhip and profitability through sensitivity and statistical analysis. Our results suggest that the inclusion of three way recovery in reverse channel and product exchange policy in the forward channel reduce the order variation and bullwhip effect at both retailer and distributor level and increases the profitability of RL operations. In addition, we redefine the reverse logistics framework with “open-loop” in which the remanufactured products are redistributed only in the secondary market and compare the performance of open-loop model with that of closed-loop. Extended numerical investigation provides insights to the decision makers regarding the actions which can lead to better performance of the system.     

Perturbed Sierpinski carpet resonator and its usage in compact dual and triple band bandpass filters

In this paper, perturbed Sierpinski carpet fractal shaped resonator is characterized and applied in the design of multiband band pass filters (BPFs). The route to achieving compact multimode resonators starting from the Sierpinski carpet fractal shaped resonator is detailed. The proposed resonators are used to demonstrate two topologies of dual band bandpass filters with passband center frequencies at 3.5 GHz as well as 5.5 GHz, respectively. Both the designs exhibit nearly identical passband bandwidth. In the second design, it is observed that the second passband gets slightly shifted towards 5.85 GHz. However, with edge loading this shift is nullified. A scaled down version of the same resonator is designed and three such resonators are interdigitally coupled in conjunction with complementary split ring resonators to exhibit a novel technique of achieving compact triband bandpass filter. All designs have acceptable passband insertion loss in the respective bands. Accessories are used to improve passband selectivity in all designs and also a wide stop band till 10 GHz is obtained. Fabrication prototypes for all the variants are realized with simulated and measured results in good agreement. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:418–425, 2016.     

Guarding a Terrain by Two Watchtowers

Given a polyhedral terrain T with n vertices, the two-watchtower problem for T asks to find two vertical segments, called watchtowers, of smallest common height, whose bottom endpoints (bases) lie on T, and whose top endpoints guard T, in the sense that each point on T is visible from at least one of them. There are three versions of the problem, discrete, semi-continuous, and continuous, depending on whether two, one, or none of the two bases are restricted to be among the vertices of T, respectively.     

On the design and optimization of diffusion-controlled,planar delivery devices

Planar delivery devices are defined as multi-layer assemblies of paints, coatings or films designed to deliver chemicals into an environment at a predetermined rate. A readily manufacturable design that consists of two or three layers having different initial loadings of the chemical is described and optimized. Release of a chemical from the device is modeled as one-dimensional Fickian diffusion. A variety of release profiles, i.e. flux versus time, can be achieved by manipulating device parameters such as the thicknesses and initial chemical loadings of the different layers. The usual objective function is to maximize the utilization of the chemical over the design life of the device. Constraints on this optimization include the minimum effective delivery rate, the time required to achieve the minimum delivery rate, and the maximum allowable delivery rate. An important result is that an approximately constant delivery rate of a chemical into a zero-concentration environment is possible using a nearly universal design. The universal design has two chemical containing layers, each having a scaled thickness of 0.5, and one layer, initially devoid of chemical, with a scaled thickness of 0.14. The scaled initial concentrations in the layers, beginning with the layer farthest from the environment are 1.6, 0.4, and 0. Desired average delivery rates and device lifetimes are achieved by a single, typically empirical step in which the diffusivity is fixed to give an optimized utilization of the chemical over the life of the device. Adjustment of the design parameters, including the use of more than three layers, provides little benefit. The same general design, with adjusted parameters, gives good results when the desired profile includes a controlled initial burst or when the delivery rate is a linearly decreasing or increasing function of time.     

Spray evaporation of liquid foods

‘Spray evaporation’ based on the principle of adiabatic humidification was examined as an evaporation technique for the concentration of two types of representative liquid foods, namely, fruit juice and milk. The concentration of apple juice could be increased from 10.0 to 13.0 °Brix by this technique without application of heat utilizing the humidity potential to an extent of 89%. Employing heated process air during processing increased the amount of water evaporation owing to increased saturation humidity level, enabling higher concentrations to be achieved in apple juice (48 °Brix), reconstituted milk (29 °Brix) and single toned milk (22 °Brix). Feed flow rate had an inverse effect on the final concentration under otherwise similar conditions. Evaporative cooling associated with spray evaporation actually delivered the concentrate at a relatively lower temperature. By manipulating the operating conditions, humidity potential could be utilized to the extent of 55% with heated process air. The spray evaporation technique seemed to have a good potential for the concentration of liquid foods.     

Impact of Reactive Oxygen and Nitrogen Species Produced by Plasma on Mdm2–p53 Complex

The study of protein–protein interactions is of great interest. Several early studies focused on the murine double minute 2 (Mdm2)–tumor suppressor protein p53 interactions. However, the effect of plasma treatment on Mdm2 and p53 is still absent from the literature. This study investigated the structural changes in Mdm2, p53, and the Mdm2–p53 complex before and after possible plasma oxidation through molecular dynamic (MD) simulations. MD calculation revealed that the oxidized Mdm2 bounded or unbounded showed high flexibility that might increase the availability of tumor suppressor protein p53 in plasma-treated cells. This study provides insight into Mdm2 and p53 for a better understanding of plasma oncology.     

Influence of reactive compatibilizers on the rheometrical and mechanical properties of PA6/LDPE and PA6/HDPE blends

In this work, the influence of reactive compatibilizers on the rheometrical and mechanical properties of polyamide 6/low density polyethylene (PA6/LDPE) and polyamide 6/high density polyethylene (PA6/HDPE) blends was investigated. Polyethylene grafted with maleic anhydride (PEgMA), polyethylene grafted with acrylic acid (PEgAA), and ethylene-methyl acrylate-glycidyl methacrylate (EMA-GMA) were used as compatibilizers. The blends were characterized by torque rheometry, mechanical properties, and morphology. Rheometrical properties results show that PEgMA and PEgAA compatibilizers are more reactive with PA6 than EMA-GMA. Mechanical properties and scanning electron microscopy analysis results show that EMA-GMA compatibilizer is as effective as PEgMA and PEgAA for PA6/LDPE blend. For PA6/HDPE blend, PEgAA and EMA-GMA compatibilizers proved to be as effective as PEgMA. For PA6/HDPE blend compatibilized with PEgAA, an intriguing “web” or “bridge” like structure was observed.     

Organo-functionalized mesoporous supports for Jacobsen-type catalyst: Laponite versus MCM-41

In order to exploit the different textural properties of Laponite and MCM-41, specifically in terms of their external versus internal surface areas, in the covalent anchoring of a chiral Mn(III) salen complex, these materials were functionalized with 3-aminopropyltriethoxysilane (APTES), subsequently activated with sodium ethoxide, and finally used to anchor the Jacobsen catalyst derivative C1. All the materials were characterized by nitrogen elemental analysis, XPS, PXRD, nitrogen adsorption at −196 °C, FTIR and for those with the immobilized complex, they were additionally characterized by Mn AAS. The APTES anchored at the edges of the Laponite single crystals and inside the MCM-41 pores. Moreover, under the same preparative conditions, higher amount of APTES was anchored onto MCM-41 than onto Laponite, which is due to the higher surface area of MCM-41 compared to Laponite, as well as to its more exposed SiO₄ tetrahedra. Activation of the two organo-functionalized materials with sodium ethoxide originated anionic nitrogen groups as deduced by the increase of surface sodium content of these materials and N1s binding energy changes, but led to a small decrease in N bulk content as a result of some APTES leaching. Moreover, for MCM-41 some disruption of the silica framework occurred as a consequence of the basic treatment, as suggested by XPS, PXRD, and nitrogen adsorption study. The APTES functionalized Laponite and MCM-41 materials, as well as the activated analogs, were able to anchor C1 through axial coordination of the metal centre to the grafted surface nitrogen atoms. APTES functionalized MCM-41 presented similar complex content to Laponite analog, what points out for the fact that, at least for the bulky complex used in this work, there was no clear benefit in using a material of high internal area; for the ethoxide activated analogs, Laponite showed the highest complex content of all materials, but MCM-41 was able to anchor the lowest complex quantity, probably as a consequence of damaging effect caused by the basic treatment within its porous structure. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.