In vitro modelling of simultaneous interactions of Listeria monocytogenes,Lactobacillus sakei,and Staphylococcus carnosus

Food Science and Biotechnology - The Jameson effect model describes suppression of microorganism growth as being dependent on non-specific competition. This model was developed for simultaneous...     

Biowaste-Derived,Self-Organized Arrays of High-Performance 2D Carbon Emitters for Organic Light-Emitting Diodes

Low-cost flexible organic light-emitting diodes (OLEDs) with nanoemitter material from waste open up new opportunities for sustainable technology. The common emitter materials generated from waste are carbon dots (CDs). However, these have poor luminescent properties. Further solid-state emission quenching makes application in display devices challenging. Here, flexible and rigid OLED devices are demonstrated using self-assembled 2D arrays of CDs derived from waste material, viz., human hair. High-performance CDs with a quantum yield (QY) of 87%, self-assembled into 2D arrays, are achieved by improving the crystallinity and decreasing the CDs' size distribution. The CD island array exhibits ultrahigh hole mobility (≈10⁻¹ cm² V⁻¹ s⁻¹) and significant reduction in solid-state emission quenching compared to pristine CDs; hence, it is used here as an emitting layer in both indium tin oxide (ITO)-coated glass and ITO-coated flexible poly(ethylene terephthalate) (PET) substrate OLED devices, without any hole-injection layer. The flexible OLED device exhibits a stable, voltage-independent blue/cyan emission with a record maximum luminescence of 350 cd m⁻², whereas the OLED device based on the rigid glass substrate shows a maximum luminescence of 700 cd m⁻². This work sets up a platform to develop next-generation OLED displays using CD emitters derived from the biowaste material.     

Developments of Diketopyrrolopyrrole-Dye-Based Organic Semiconductors for a Wide Range of Applications in Electronics

In recent times, fused aromatic diketopyrrolopyrrole (DPP)-based functional semiconductors have attracted considerable attention in the developing field of organic electronics. Over the past few years, DPP-based semiconductors have demonstrated remarkable improvements in the performance of both organic field-effect transistor (OFET) and organic photovoltaic (OPV) devices due to the favorable features of the DPP unit, such as excellent planarity and better electron-withdrawing ability. Driven by this success, DPP-based materials are now being exploited in various other electronic devices including complementary circuits, memory devices, chemical sensors, photodetectors, perovskite solar cells, organic light-emitting diodes, and more. Recent developments in the use of DPP-based materials for a wide range of electronic devices are summarized, focusing on OFET, OPV, and newly developed devices with a discussion of device performance in terms of molecular engineering. Useful guidance for the design of future DPP-based materials and the exploration of more advanced applications is provided.     

Advanced Materials for Use in Soft Self‐Healing Devices

Devices integrated with self‐healing ability can benefit from long‐term use as well as enhanced reliability, maintenance and durability. This progress report reviews the developments in the field of self‐healing polymers/composites and wearable devices thereof. One part of the progress report presents and discusses several aspects of the self‐healing materials chemistry (from non‐covalent to reversible covalent‐based mechanisms), as well as the required main approaches used for functionalizing the composites to enhance their electrical conductivity, magnetic, dielectric, electroactive and/or photoactive properties. The second and complementary part of the progress report links the self‐healing materials with partially or fully self‐healing device technologies, including wearable sensors, supercapacitors, solar cells and fabrics. Some of the strong and weak points in the development of each self‐healing device are clearly highlighted and criticized, respectively. Several ideas regarding further improvement of soft self‐healing devices are proposed.     

Catalytic reduction in 4‐nitrophenol using Actinodaphne madraspatana Bedd leaves‐mediated palladium nanoparticles

There is a growing demand for the development of non‐toxic, cost‐effective, and environmentally benign green synthetic strategy for the production of metal nanoparticles. Herein, the authors have reported Actinodaphne madraspatana Bedd (AMB) leaves as the bioreducing agent for the synthesis of palladium nanoparticles (PdNPs) and its catalytic activity was evaluated for the reduction of 4‐nitrophenol (4‐NP) to 4‐aminophenol with undisruptive effect on human health and environment. The broad and continuous absorbance spectrum obtained in the UV–visible region indicated the formation of PdNPs. The synthesized PdNPs were found to be crystalline, spherical, and quasi‐spherical in shape with an average particle size of 13 nm was confirmed by X‐ray diffractometer and transmission electron microscope. Fourier transform infrared spectra revealed the active photo constituents present in the aqueous extract of AMB involved in the bioreduction of palladium ions to PdNPs. The catalytic activity of biosynthesized PdNPs was demonstrated for the reduction of 4‐NP via electron‐relay process. Also, the influential parameters such as catalyst dosage, concentration of 4‐NP, and sodium borohydride were studied in detail. From the present study, PdNPs were found to be a potential nanocatalyst for nitro compound reduction and also for environmental remediation of wastewater effluents from industries.Inspec keywords: palladium, nanoparticles, particle size, nanofabrication, catalysis, catalysts, reduction (chemical), organic compounds, ultraviolet spectra, visible spectra, X‐ray diffraction, transmission electron microscopy, Fourier transform infrared spectraOther keywords: nitro compound reduction, environmental remediation, wastewater effluents, Pd, nanocatalyst, sodium borohydride, 4‐NP concentration, catalyst dosage, electron‐relay process, bioreduction, aqueous extract, Fourier transform infrared spectra, transmission electron microscopy, X‐ray diffractometry, particle size, quasispherical shape, spherical shape, crystalline shape, UV‐visible abosprtion spectra, human environment, human health, 4‐aminophenol, catalytic activity, bioreducing agent, metal nanoparticles, Actinodaphne madraspatana Bedd leaves‐mediated palladium nanoparticles, 4‐nitrophenol, catalytic reduction     

Effect of refining of crude rice bran oil on the retention of oryzanol in the refined oil

The effect of different processing steps of refining on retention or the availability of oryzanol in refined oil and the oryzanol composition of Indian paddy cultivars and commercial products of the rice bran oil (RBO) industry were investigated. Degumming and dewaxing of crude RBO removed only 1.1 and 5.9% of oryzanol while the alkali treatment removed 93.0 to 94.6% of oryzanol from the original crude oil. Irrespective of the strength of alkali (12 to 20° Be studied), retention of oryzanol in the refined RBO was only 5.4–17.2% for crude oil, 5.9–15.0% for degummed oil, and 7.0 to 9.7% for degummed and dewaxed oil. The oryzanol content of oil extracted from the bran of 18 Indian paddy cultivars ranged from 1.63 to 2.72%, which is the first report of its kind in the literature on oryzanol content. The oryzanol content ranged from 1.1 to 1.74% for physically refined RBO while for alkali-refined oil it was 0.19–0.20%. The oil subjected to physical refining (commercial sample) retained the original amount of oryzanol after refining (1.60 and 1.74%), whereas the chemically refined oil showed a considerably lower amount (0.19%). Thus, the oryzanol, which is lost during the chemical refining process, has been carried into the soapstock. The content of oryzanol of the commercial RBO, soapstock, acid oil, and deodorizer distillate were in the range: 1.7–2.1, 6.3–6.9, 3.3–7.4, and 0.79%, respectively. These results showed that the processing steps—viz., degumming (1.1%), dewaxing (5.9%), physical refining (0%), bleaching and deodorization of the oil—did not affect the content of oryzanol appreciably, while 83–95% of it was lost during alkali refining. The oryzanol composition of crude oil and soapstock as determined by high-performance liquid chromatography indicated 24-methylene cycloartanyl ferulate (30–38%) and campesteryl ferulate (24.4–26.9%) as the major ferulates. The results presented here are probably the first systematic report on oryzanol availability in differently processed RBO, soapstocks, acid oils, and for oils of Indian paddy cultivars.     

Thermal denaturation of recombinant human lysozyme from rice: effect of pH and comparison with human milk lysozyme

Thermal denaturation of recombinant human lysozyme from rice has been studied by differential scanning calorimetry at acidic (4.2), neutral (7.2) and basic (9.2) pH levels at various heating rates, and it has been compared with thermal denaturation of human lysozyme isolated from milk at the same pH levels at a heating rate of 10 °C/min. Data obtained from heat-induced unfolding and subsequent refolding after heating indicate that thermal denaturation of both lysozymes undergoes a two-state process. The maximum temperature of the endothermic peaks and the enthalpy change of denaturation indicate that recombinant and milk lysozymes possess similar thermostability, which is higher at acidic than at neutral pH. On the other hand, both proteins are more thermolabile at basic pH. Lysozyme from human milk shows a higher tendency to aggregate than recombinant human lysozyme from rice during the thermal denaturation process.     

Calibration of phoswich-based lung counting system using realistic chest phantom

A phoswich detector, housed inside a low background steel room, coupled with a state-of-art pulse shape discrimination (PSD) electronics is recently established at Radiological Safety Division of IGCAR for in vivo monitoring of actinides. The various parameters of PSD electronics were optimised to achieve efficient background reduction in low-energy regions. The PSD with optimised parameters has reduced steel room background from 9.5 to 0.28 cps in the 17 keV region and 5.8 to 0.3 cps in the 60 keV region. The Figure of Merit for the timing spectrum of the system is 3.0. The true signal loss due to PSD was found to be less than 2 %. The phoswich system was calibrated with Lawrence Livermore National Laboratory realistic chest phantom loaded with (241)Am activity tagged lung set. Calibration factors for varying chest wall composition and chest wall thickness in terms of muscle equivalent chest wall thickness were established. (241)Am activity in the JAERI phantom which was received as a part of IAEA inter-comparison exercise was estimated. This paper presents the optimisation of PSD electronics and the salient results of the calibration.     

Synthesis and characterization of poly[methyl methacrylate‐co‐2‐ethylhexyl acrylate‐co‐poly(propylene glycol diacrylate)] latices

The emulsion polymerization of the monomers methyl methacrylate (MMA) and 2‐ethylhexyl acrylate (EHA) was studied to investigate the effect of the crosslinkable monomer poly(propylene glycol diacrylate) (PPGDA). IR spectroscopy, NMR, differential scanning calorimetry, gel permeation chromatography, and scanning electron microscopy were used to characterize the synthesized polymers. These polymers were coated on glass panels and cured at appropriate temperatures to study the physical properties, swelling behavior, surface tension, and contact angle of these polymer latices. The results show that as the concentration of EHA monomer increased, the surface tension of the latices decreased. The copolymers were characterized by ¹H‐NMR spectroscopy to ensure the absence of unreacted monomer, and the results confirm the incorporation of EHA units in the copolymer. The contact angle of the latices on the glass substrate was smaller than that on the metal. The swelling mechanism of the film showed that the Fickian diffusion coefficient with 10 wt % PPGDA was at a minimum value and was the most highly crosslinked polymer among the samples. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011