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The antibacterial effect of nanoparticles is mainly studied on the ensembles of the bacteria. In contrast, the optical tweezer technique allows the investigation of similar effects on individual bacterium. E. coli is a self-propelled micro-swimmer and ATP-driven active microorganism. In this work, an optical tweezer is employed to examine the mechanical properties of E. coli incubated with ZnO and Ag nanoparticles (NP) in the growth medium. ZnO and Ag NP with a concentration of 10 µg/ml were dispersed in growth medium during active log-growth phase of E. coli. This E. coli-NP incubation is further continued for 12 h. The E. coli after incubation for 2 h, 6 h and 12 h were separately studied by the optical tweezer for their mechanical property. The IR laser (λ = 975 nm; power = 100 mW) was used for trapping the individual cells and estimated trapping force, trapping stiffness and corner frequency. The optical trapping force on E. coli incubated in nanoparticle suspension shows linear decreases with incubation time. This work brings the importance of optical trapping force measurement in probing the antibacterial stress due to nanoparticles on the individual bacterium. [ABSTRACT FROM AUTHOR]

We present a concept of a wettingdefect of continuously variablestrength based on electrowetting, along with a capillary force sensoradapted for the characterization of macroscopically heterogeneoussurfaces. Patterned electrodes submerged under an insulating layerare used to generate potential wells for drops of electrically conductiveliquids on the solid surface, with a well depth that scales with thediameter of the drop and square of the applied alternating (AC) voltage.We characterize the strength of the electrowetting trap and the hystereticmotion of the drop along the surface, using a simple force sensorbased on optical imaging of a thin bendable capillary. A force resolutionof approximately 0.1 ?N is achieved. [ABSTRACT FROM AUTHOR]

Microorganisms produce biosurfactant (BS)/bioemulsifier (BE) with wide structural and functional diversity which consequently results in the adoption of different techniques to investigate these diverse amphiphilic molecules. This review aims to compile information on different microbial screening methods, surface active products extraction procedures, and analytical terminologies used in this field. Different methods for screening microbial culture broth or cell biomass for surface active compounds production are also presented and their possible advantages and disadvantages highlighted. In addition, the most common methods for purification, detection, and structure determination for a wide range of BS and BE are introduced. Simple techniques such as precipitation using acetone, ammonium sulphate, solvent extraction, ultrafiltration, ion exchange, dialysis, ultrafiltration, lyophilization, isoelectric focusing (IEF), and thin layer chromatography (TLC) are described. Other more elaborate techniques including high pressure liquid chromatography (HPLC), infra red (IR), gas chromatography-mass spectroscopy (GC-MS), nuclear magnetic resonance (NMR), and fast atom bombardment mass spectroscopy (FAB-MS), protein digestion and amino acid sequencing are also elucidated. Various experimental strategies including static light scattering and hydrodynamic characterization for micelles have been discussed. A combination of various analytical methods are often essential in this area of research and a numbers of trials and errors to isolate, purify and characterize various surface active agents are required. This review introduces the various methodologies that are indispensable for studying biosurfactants and bioemulsifiers. [ABSTRACT FROM AUTHOR]

The ferroelectric liquid crystals (FLC) composites with improved electro-optic properties, obtained by incorporating CdSe (CS) nanoplatelets (NPLs), are reported. Noticeable improvementin optical contrast, saturation voltage, response time, and brightness of FLC have been found. The improvements of electro-optical properties are the results of enhanced molecular alignment of FLC due to the presence of CS NPLs. Time resolved photoluminescence (TRPL) measurements reveal NPLs surface energy transfer in FLC. Two types of Fӧrster resonant energy transfer (FRET) is observed in CS incorporated FLC. First is homo FRET which is the transfer of exciton within stacked CS NPLs and second is FRET between FLC and CS NPLs. FRET are supporting the CS incorporated FLC to get superior electro-optic properties. These findings may create opportunity of future CS NPLs incorporated FLC based display devices having better electro-optical properties. [ABSTRACT FROM AUTHOR]

KCFLC 7S, a ferroelectric liquid crystal (FLC) shows improved dielectric and electro-optic properties by the incorporation of alloyed quaternary ZnCuGaS2/ZnS core/shell (ZCZ) quantum dots (QDs). Four different Zn alloyed ZCZ QDs (ZCZ-0, ZCZ-0.5, ZCZ-1, and ZCZ-1.5) incorporated in FLC and have been studied with the help of optical, dielectric and ferroelectric characterisations. Substantial changes of optical contrast, molecular ordering, photoluminescence, dielectric constant, dielectric loss factor, response time, and helical pitch of FLC are observed and attributed to varying molecular ordering. The effective confinement of exciton wavefunction in core of QDs results in improved molecular ordering of FLC material. The Zn alloyed ZCZ QDs incorporated FLC may be resulted for future brighter, high contrast, large viewing angle and memory based display device. [ABSTRACT FROM AUTHOR]

The spread of infectious disease, virus epidemic, fashion, religion and rumors is strongly affected by the nearest neighbor hence underlying morphologies of the colonies are crucial. Likewise, the morphology of naturally grown patterns ranges from fractal to compact with lacunarity. We analyze the contact process on the fractal clusters simulated by generalized Diffusion-limited Aggregation (g-DLA) model. In g-DLA model, randomly walking particle is added to the cluster with sticking probability p depending on the local density of occupied sites in the neighborhood of radius r from the center of active site. It takes values 1 , α and α 2 (0 < α ≤ 1) for highly dense, moderately dense and sparsely occupied regions, respectively. The corresponding morphology varies from fractal to compact as α varies from 1 to 0. Interestingly, the contact process on the g-DLA clusters shows clear transition from active phase to absorbing phase and the exponent values fall between 1-d and 2-d in directed percolation (DP) universality class. The local persistence exponents at transition are studied and are found to be much smaller than that for 1-d and 2-d DP cases. We conjecture that infection in the fractal cluster does not easily reach far-flung or remote areas at the periphery of the cluster. [ABSTRACT FROM AUTHOR]

Outdoor electrowetting (EW)-based applications need consistent wetting response in the temperatures ranging from − 40 to 70 °C. Aqueous ethylene glycol is commonly used as thermostable liquid; nevertheless, its EW behaviour over a wide range of temperature is less known. We examine this behaviour for both ac and dc voltages over the temperature range from − 25 to 65 °C. The self-consistent EW responses, i.e. cosine of contact angle versus voltage square, are analysed to illustrate the EW behaviour. There is a systematic increase in EW response with temperature confirmed from the linear dependence of interfacial tension on temperature. Our result corroborates Eötvös phenomenological relation. We suggest the need of correction voltage with changing temperature to maintain uniform EW response over this temperature range. Further with decreasing temperature, the solution viscosity increases more rapidly than the increase in interfacial tension value, and thus the capillary number (C a = μ v / γ) gets partially regulated. This is seen as a marginal variation in the switching time of the EW contact angle during the OFF voltage state to ON state and vice versa. Finally, the working of a prototype liquid lens at − 25 °C, the lowest operating temperature, is demonstrated. [ABSTRACT FROM AUTHOR]

We present a possible link between nonequilibrium phase transition observed in patchy diffusion-limited aggregation (DLA) [M. J. Kartha and A. Sayeed, Phys. Lett. A 380, 2791 (2016)] and directed bond percolation (DP). A system of directed percolation with patchy particles (patchy DP) in which the bond connectivity is established depending on patch size p is analyzed. It is observed that patchy DP starting from a single seed shows a nonequilibrium phase transition. Below a critical value of the patch size pc, the system reaches an absorbing state above which is a fluctuating active state as observed in the DP system. The value of this nonuniversal parameter pc is observed to be slightly higher than the value observed in patchy DLA. Close to the critical value, the order parameter P(∞)∼(p-pc)β where β=0.272±0.010, which is consistent with the directed-percolation universality class. Therefore the intrinsic nature of patchy DP is responsible for the phase transition in patchy DLA. This study reveals that the estimated critical value of patch size pc=0.80625±0.00020 in patchy DP is different from the critical bond probability pc=0.6447 in the DP system. This elucidates that the bond probability in DP is not equivalent to the patch probability of a particular site. Our work also gives an insight into the problem related with formation of an extended network of pentagon subunits in connection with the virus capsid. [ABSTRACT FROM AUTHOR]

The growth of GaN films along nonpolar crystallographic planes, especially s‐plane, on c‐Al2O3 substrate using pulsed laser deposition (PLD) is reported. The role of substrate temperature variation on the structural and morphological properties along this plane is investigated using different techniques. The degree of crystallinity, surface roughness, etc. associated with films are observed to depend strongly on deposition conditions, for example, substrate temperature kept during deposition. Micro‐Raman investigations reveal the presence of an unexpected phonon mode, E1(LO), in the spectra for films deposited at high temperature where prominent crystal growth is observed. The presence of the particular phonon mode observed herewith is due to the nonpolar growth of GaN crystals as well as high density of defects and/or plasmon coupling present in the films. Strong near‐band‐edge emission in the photoluminescence spectra for all specimens shows moderate optical properties of the films. Elemental analysis using X‐ray photoelectron spectra technique confirms the formation of GaN phase for all specimens. [ABSTRACT FROM AUTHOR]

Bacterial infections are major constraints in aquaculture farming. These pathogens often adapt to the biofilm mode of growth and resist antibiotic treatments. We have used a non-toxic glycolipid biosurfactant (BS-SLSZ2) derived from a marine epizootic bacterium Staphylococcus lentus to treat aquaculture associated infections in an eco-friendly manner. We found that BS-SLSZ2 contained threose, a four-carbon sugar as the glycone component, and hexadecanoic and octadecanoic acids as the aglycone components. The critical micelle concentration of the purified glycolipid was 18mgmL-1. This biosurfactant displayed anti-adhesive activity and inhibited biofilm formation by preventing initial attachment of cells onto surfaces. The biosurfactant (at a concentration of 20 µg) was able to inhibit Vibrio harveyi and Pseudomonas aeruginosa biofilms by 80.33 ± 2.16 and 82 ± 2.03%, respectively. At this concentration, it was also able to disrupt mature biofilms of V. harveyi (78.7 ± 1.93%) and P. aeruginosa (81.7 ± 0.59%). The biosurfactant was non-toxic towards Artemia salina. In vivo challenge experiments showed that the glycolipid was effective in protecting A. salina nauplii against V. harveyi and P. aeruginosa infections. This study highlights the significance of marine natural products in providing alternative biofilm controlling agents and decreasing the usage of antibiotics in aquaculture settings. [ABSTRACT FROM AUTHOR]

Electro-optic measurements reveal improved molecular ordering of ferroelectric liquid crystals (FLCs) by the presence of greener ternary CuGaS2/ZnS core/shell (CGZ) quantum dots (QDs). Experimental findings show that ternary CGZ QDs improve the anchoring of FLC which is validated by the increased primary- and secondary-order parameters (θ and Ps, respectively). The improved ordering of host FLCs is attributed to the enhanced localised charges by carrier trapping at intrinsic defect deep states in core assisted by reduced charge leakage probability, due to ZnS shell of CGZ QDs. The ternary CGZ QDs also improve photoluminescence and optical contrast of FLCs due to increase in molecular alignment. Helical nature of FLCs retained with incorporation of CGZ QDs was confirmed by pitch measurements. All these observations pointed out a way for better FLC-based display device. [ABSTRACT FROM AUTHOR]

This paper studies various wetting characteristics on different surfaces of Polydimethylsiloxane (PDMS) polymer. The random roughness of the surface is engineered by using sandpapers to introduce different order of hydrophobic properties to understand the temporal evolution of drying droplets. We develop statistical models to predict temporal evolution of the base diameter, height, surface, and contact angle of drying droplets with varying grit size or surface roughness. Five different robust polynomial regression models have been compared for the prediction of three dependent variables - base diameter, height, and surface of drying droplets for random rough surfaces. In a nutshell, we here identify the best statistical model to capture the dynamics of drying droplets on hydrophobic surfaces of random roughness characteristics. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Quality non-polar GaN films (which itself is believed to be challenging) are deposited on the polar substrates using PLD route. • These non-polar GaN films exposed to 60Co Gamma radiations varying dose values from 40 kGy to maximum value of 260 kGy under atmospheric conditions. • The critical investigations reported on the non-polar GaN films for the first time, clearly demonstrate the resistive nature of the films against expose to energetic gamma rays is highly impressive. • The result reported herewith demonstrate use of non-polar GaN films can be one of the options to fabricate next generation of gamma ray detectors. The GaN films/layers exposed to γ-radiations is known to harvest defects and vacancies in the crystals producing donor, acceptor and recombination centers within the bandgap. Therefore it is important to investigate and study the γ- ray irradiation effects on various physical and chemical properties of a material before any optoelectronic and/or electronic devices are being fabricated. To avoid Stark effect which is observed in most of the optoelectronic devices fabricated using GaN films grew along polar face, use of non-polar GaN films is suggested by researchers. To address such issues the article reports the investigations of physical and chemical properties of non-polar GaN films grown on polar substrate using pulsed laser deposition, which were exposed to the 60Co gamma rays varying dose values. Resistive nature against the impairment of the films caused by γ-rays observed herewith is highly encouraging, suggesting the use of non-polar GaN films as radiations harden material suitable for fabricating new generation γ-ray detectors. To our knowledge very limited information is available that report such investigations. [ABSTRACT FROM AUTHOR]

We present electrowetting (EW) on a Bilayer Dielectric Stack (BDS) made from PMMA polymer and a top layer of fluoropolymer. The effective capacitance of such BDS is inversely proportional to the layer thickness. The EW response was analyzed on distinct BDS surfaces where the PMMA layer thickness was varied from a few nanometers to micrometer, and the top layer thickness was kept fixed at 20 nm. The highest value of the effective capacitance, εeff ~ 3, was recorded on a BDS for PMMA layer thickness dp ~ 0.8 μm with Fluoropel® thickness dF = 20 nm. The BDS surface showed consistent EW response for ac as well as for dc-voltages without any EW hysteresis. As a proof of concept, the BDS was utilized on the conductive electrodes of the liquid lens and successfully achieved the manipulation of the oil-liquid interface leading to the magnification of the object placed at the focal plane. High change in EW contact angle on PMMA /Fluropel bilayer dielectric stack (BDS) The BDS bilayer- PMMA/Fluoropel with thickness 800 nm/20 nm exhibits effective dielectric constant, εeff ≈ 3. Faithful EW response for ac-voltage as well as dc-voltage. The BDS is durable and finds application in large scale EW applications. [ABSTRACT FROM AUTHOR]

Electrowetting (EW) response on a dielectric depends on its permittivity value, Young contact angle and voltage amplitude. We present a large change in EW contact angle, from 163° to 80°, on the bilayer dielectric made up of ferroelectric PVDF-HFP with a thin layer of fluoropolymer. The thickness values of both layers were separately optimized for high effective capacitance essential for the large EW response. It reveals that the bilayer with ~ 500 nm thick PVDF-HFP layer and ~ 50 nm thin layer of Teflon results in the maximum value of effective dielectric constant, ε ≈ 8. Besides this gain, dc-voltage EW response exhibits hysteresis mainly due to polarization in the ferroelectric layer such that, hysteretic offset voltage was found to depend on the applied voltage amplitude and thickness of the dielectrics. Finally, bilayer was subjected to ac-voltage EW in silicone oil for ambient temperature ranging from − 25 to 70 °C. The consistent EW response in this ambient without any degradation/delamination of polymer surface confirmed the durability of the bilayer on the transparent ITO electrodes. [ABSTRACT FROM AUTHOR]

Epistructures of Ga 2 O 3 /ZnO/Ga 2 O 3 were grown on c-Al 2 O 3 substrate using pulsed laser deposition route. Thickness of ZnO layer varied to form these epistructures were investigated structurally, micro-structurally and optically using respective techniques. The modification made with the epistructures are observed to change the peak position of longitudinal optical phonon plasmon (LPP) i.e. A1(LO) mode of the wurtzite ZnO. The specific mode position observed suggests the presence of optical phonon confinement, defects and impurities present at the interface of the layer with others. However the photoluminescence spectra recorded on these epistructures showed quenching of unwanted visible emissions generally observed in device quality of ZnO and gallium oxide films/crystals is interesting. Further the temperature dependent PL investigations performed on selected specimens confirmed that the donor and acceptor excitonic emissions observed are purely governed by either the electron phonon interactions or due to the lattice dilation and the electron phonon interactions both, depending on the thickness of a sandwiched layer i.e. ZnO. The results observed herewith are encouraging considering use epistructures in thin film form to fabricate UV detectors where cost, repeatability and ease of manufacturing are one of the prerequisites. • Epistructures of Ga 2 O 3 /ZnO/Ga 2 O 3 were grown on c-Al 2 O 3 substrate using pulsed laser deposition route. • Peak position of longitudinal optical phonon plasmon (LPP) for wurzite ZnO is observed to change with thickness of w-ZnO. • Unwanted visible emissions (observed even in device quality ZnO and Ga2O3) in PL of these epistructures showed quenching. [ABSTRACT FROM AUTHOR]

Growth of ZnO/Ga 2 O 3 and Ga 2 O 3 /ZnO heterostructures on c-Al 2 O 3 substrate is demonstrated using pulsed laser deposition route. Based on the structural and surface morphological investigations hypothetical model explaining the respective growth is proposed. The template (i.e. Ga 2 O 3 /Al 2 O 3 and ZnO/Al 2 O 3) used to grow the final film are observed to control the overall micro structural, electrical as well as optical properties of these heterostructure. For e.g. broad UV emission is observed for Ga 2 O 3 film deposited on the ZnO/Al 2 O 3 substrate, whereas expected near band-edge emission is reported for ZnO film deposited on Ga 2 O 3 /Al 2 O 3 substrate. Various emission processes involved in harvesting the UV-blue emission especially for Ga 2 O 3 /ZnO/Al 2 O 3 heterostructure is explained by proposing the band diagram schematic. • Epitaxial growth of ZnO/Ga2O3 and Ga2O3/ZnO heterostructures on c-Al2O3 substrate using pulsed laser deposition. • Hypothetical growth model explaining the relationship in between materials to grow respective heterostructures. • Band diagram explaining possible optical emissions responsible for observed UV-Blue emissions. • Substantial increase in the photocurrent recorded for ZnO/Ga2O3/Al2O3 specimen. [ABSTRACT FROM AUTHOR]

Mn 3 O 4 thick film electrodes have been synthesized by spray pyrolysis method. Effect of its two important synthesis parameters viz. solution feed rate and substrate temperature has been studied. Solution feed rate was studied in the range of 150 to 250 cc.min −1 while substrate temperature was varied from 325 to 400 °C. X-ray diffraction studies confirms Hausmannite crystal structure and SEM studies show spherical grains, uniformly distributed porous microstructure obtained for deposited Mn 3 O 4 thick films. The contact angle measurements show these electrodes have very low contact angle in the range of 2−8° and high surface energy. Cyclic voltammetry study showed specific and interfacial capacitance of Mn 3 O 4 electrodes increased with increase in solution feed rate, due to increased thickness of films. On the other hand, substrate temperature shows effect on film morphology, grain size and porosity, however, does not show any explicit effect on specific and interfacial capacitance. Highest values of specific and interfacial capacitance exhibited by Mn 3 O 4 are 187.79 F.g −1 and 0.82 F.cm −2 respectively for sample prepared at 250 cc.min −1 solution feed rate and 325 °C substrate temperature. The calculated energy density and power density for the same sample was 26.08 Wh.kg −1 and 1.01 kW.kg −1 respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Superhydrophobic and icephobic surface. • Hetero-nanostructure ZnO-Cu 2 O. • Teflon-AF top layer coating. • Droplet rebounding for wide velocity range. • Dropwise condensation and Ice-phobicity for freezing rain. We demonstrate hetero-nanostructured rough surface with solution based hydrophobic coating for robust superhydrophobic (SH) properties. The copper foil was anodically etched to generate Cu 2 O micro-needles and then ZnO nanorods were grown on Cu 2 O to create ZnO/Cu 2 O micro-nano hierarchical rough surface. A thin layer of Teflon AF was applied as a low surface energy coating on the top of the hierarchical surface. These surfaces were characterized for their structural phases using the X-ray diffraction technique and multiscale hierarchical surface morphology was confirmed using FESEM and AFM techniques. Wetting properties like static and dynamic water contact angle (CA) were analyzed using the advancing receding contact angle (ARCA) technique. This surface shows superhydrophobic properties with static CA of 157° and a roll-off angle of 3°. The durability of the SH surfaces was examined by water droplet impact for a range of velocities. The droplet rebounding is consistently seen up to Weber number, W e ∼ 220. When the SH surface was cooled to −10 °C, dropwise condensation takes place. In this case, self-propelled jumping of droplets via multiple coalescences of microdroplets was observed. In the freezing rain condition, this surface exhibits poor adhesion to ice formation demonstrating an icephobic property. The surface retains SH properties even to the UVC exposure of about 12 J/cm2. The fabrication of the SH surface involves solution-based processes which are scalable to mass production for applications ranging from enhanced heat conduction to water-repellent coatings. [ABSTRACT FROM AUTHOR]

The perpetual use of antibiotics against pathogens inadvertently altered their genes that have translated into an unprecedented resistance in microorganisms in the twenty-first century. Many researchers have formulated bactericidal and bacteriostatic inorganic nanoparticle-based antiseptics that may be linked to broad-spectrum activity and far lower propensity to induce microbial resistance than organic-based antibiotics. Based on this line, herein, we present observations on microbial abatement using gold-based zinc oxide nanostructures (Au@ZnO) which are synthesized using hydrothermal route. Inhibition of microbial growth and biofilm using Au@ZnO is a unique feature of our study. Furthermore, this study evinces antimicrobial and antibiofilm mechanisms of photo-eradiated Au@ZnO by disruption of cellular functions and biofilms via reactive oxygen species (ROS)-dependent generation of superoxide anion radical. The present study is significant as it introduces novel functionalities to Au@ZnO in the biomedical field which can be extended to other species of microbial pathogens. [ABSTRACT FROM AUTHOR]

Electrowetting (EW) allows an executive control on wetting of liquid in several digital micro-fluidic systems driven by both alternating (AC) and direct current (DC) voltages. The electrolytes are inevitable in all fluidic systems that can produce a huge change in conductivity and change in concentration of ions at solid-liquid interface. We report that for an orders of magnitude increase in concentration of KCl electrolyte in a droplet there is minor reduction in DC voltage EW response. The rescaled EW response validates that the result is due to change in surface tension of solution as a function of the electrolyte concentration. Our study demonstrates the efficacy of DC voltage EW in handling aqueous droplets containing a broad range of electrolyte concentration on both planar as well as interdigitated electrode platforms. [ABSTRACT FROM AUTHOR]

The grieving problem of the 21st century has been the antimicrobial resistance in pathogenic microorganisms to conventional antibiotics. Therefore, developments of novel antibacterial materials which effectively inhibit or kill such resistant microorganisms have become the need of the hour. In the present study, we communicate the synthesis of quantum dots conjugated zinc oxide nanostructures (ZnO/CdTe) as an impeder of microbial growth and biofilm. The as-synthesized nanostructures were characterized by X-ray diffraction, ultraviolet–visible spectroscopy, photoluminescence spectroscopy, field emission scanning electron microscopy and high resolution transmission electron microscopy. The growth impedance property of ZnO and ZnO/CdTe on Gram positive organism, Bacillus subtilis NCIM 2063 and Gram negative, Escherichia coli NCIM 2931 and biofilm impedance activity in Pseudomonas aeruginosa O1 was found to occur due to photocatalytical action on the cell biofilm surfaces. The impedance in microbial growth and biofilm formation was further supported by ruptured appearances of cells and dettrered biofilm under field emission scanning electron and confocal laser scanning microscope. The ZnO/CdTe nanostructures array synthesized by hydrothermal method has an advantage of low growth temperature, and opportunity to fabricate inexpensive material for nano-biotechnological applications. [ABSTRACT FROM AUTHOR]

The resurgence of infectious diseases and associated issues related to antibiotic resistance has raised enormous challenges which may possibly be confronted primarily by nanotechnology routes. One key need of critical significance in this context is the development of an agent capable of inhibiting quorum sensing mediated biofilm formation in pathogenic organisms. In this work we examine the possible use of a nanocomposite, CdTe-TiO2, as an impeder of growth and biofilm. In the presence of CdTe-TiO2, scanning electron microscopy (SEM) analysis shows exposed cells without the surrounding matrix. Confocal laser scanning microscopy shows spatially distributed fluorescence, a typical indication of an impeded biofilm, as opposed to the control which shows matrix-covered cells and continuous fluorescence, typical of biofilm formation. Quantitatively, the inhibition of biofilm was ∼57%. CdTe-TiO2 also exhibits good antibacterial properties against Gram positive and Gram negative organisms by virtue of the generation of reactive oxygen species inside the cells, reflected by a ruptured appearance in the SEM analysis. [ABSTRACT FROM AUTHOR]

The phenomenon of resistive switching (RS) has been demonstrated in several non-magnetic and some magnetic oxide systems, however the 'magnetic' aspect of magnetic oxides has not been emphasized especially in terms of low field tunability. In our work, we examined the CoFe2O4/La0.66Sr0.34MnO3 all-magnetic oxide interface system for RS and discovered a very sharp (bipolar) transition at room temperature that can be gated with high sensitivity by low magnetic fields (∼0-100 mT). By using a number of characterizations, we show that this is an interface effect, which may open up interesting directions for manipulation of the RS phenomenon. [ABSTRACT FROM AUTHOR]

In the present study, we report a quantum dot (QD)-tailored western blot analysis for a sensitive, rapid and flexible detection of the nuclear and cytoplasmic proteins. Highly luminescent CdTe and (CdTe)ZnS QDs are synthesized by aqueous method. High resolution transmission electron microscopy, Raman spectroscopy, fourier transform infrared spectroscopy, fluorescence spectroscopy and X-ray diffraction are used to characterize the properties of the quantum dots. The QDs are functionalized with antibodies of prostate apoptosis response-4 (Par-4), poly(ADP-ribose) polymerases and β actin to specifically bind with the proteins localized in the nucleus and cytoplasm of the cells, respectively. The QD-conjugated antibodies are used to overcome the limitations of conventional western blot technique. The sensitivity and rapidity of protein detection in QD-based approach is very high, with detection limits up to 10 pg of protein. In addition, these labels provide the capability of enhanced identification and localization of marker proteins in intact cells by confocal laser scanning microscopy. [ABSTRACT FROM AUTHOR]

Abstract: Marine biosphere offers wealthy flora and fauna, which represents a vast natural resource of imperative functional commercial grade products. Among the various bioactive compounds, biosurfactant (BS)/bioemulsifiers (BE) are attracting major interest and attention due to their structural and functional diversity. The versatile properties of surface active molecules find numerous applications in various industries. Marine microorganisms such as Acinetobacter, Arthrobacter, Pseudomonas, Halomonas, Myroides, Corynebacteria, Bacillus, Alteromonas sp. have been studied for production of BS/BE and exopolysaccharides (EPS). Due to the enormity of marine biosphere, most of the marine microbial world remains unexplored. The discovery of potent BS/BE producing marine microorganism would enhance the use of environmental biodegradable surface active molecule and hopefully reduce total dependence or number of new application oriented towards the chemical synthetic surfactant industry. Our present review gives comprehensive information on BS/BE which has been reported to be produced by marine microorganisms and their possible potential future applications. [Copyright &y& Elsevier]

• Novel biosurfactant 1-Pentanonacontene and 3-Hydroxy-16-methylheptadecanoic acid from Bacillus sp. SGD-AC-13. • The biosurfactants reduced the surface tension to 31.32 ± 0.926 mN/m. • The biosurfactant showed stability up to 160 °C, pH 6–12, and 50 g/L NaCl conc. • The biosurfactant increased the wettability of 2% Dursban® organophosphate pesticide. • The biosurfactant found efficient to recover 35% Used lubricant oil (ULO) and 12% Heavy weight crude oil (HWCO). In this study, a novel thermo stable biosurfactants, 1-Pentanonacontene (C 95 H 190) a fatty alkene and 3-Hydroxy-16-methylheptadecanoic acid (C 18 H 36 O 3) were isolated from a marine isolate SGD-AC-13. Biosurfactants were produced using 1% yeast extract in tap water as production medium at 24 h in flask and 12 h in bioreactor. Using 16S rRNA gene sequence (1515 bp) and BCL card (bioMérieux VITEK®), strain was identified as Bacillus sp. Crude biosurfactant reduced the surface tension of distilled water to 31.32 ± 0.93 mN/m with CMC value of 0.3 mg/ml. Cell free supernatant showed excellent emulsification and oil displacement activity with stability up to 160 °C, pH 6–12 and 50 g/L NaCl conc. Biosurfactants were characterized using FTIR, TLC, HPLC LC–MS and NMR spectroscopy. Cell free supernatant reduced the contact angle of distilled water droplet from 117° to 52.28° and of 2% pesticide from 78.77° to 73.42° while 750 μg/ml of crude biosurfactant reduced from 66.06° to 56.33° for 2% pesticide and recovered 35% ULO and 12% HWCO from the contaminated sand. To our best of knowledge, this is the first report of thermo stable fatty alkene as a biosurfactant and is structurally different from previously reported, with having potential application in agriculture, oil recovery and bioremediation. [ABSTRACT FROM AUTHOR]

Background: Lactobacillus spp. predominantly shows its presence as a normal mucosal flora of the mouth and intestine. Therefore, the objective of our research is to investigate the in-vitro conditions for the prospective of medically valuable biosurfactants (BSs) derived from Lactobacillus spp. Biosurfactant (BS) obtained from Lactobacillus spp. exhibit antibiofilm and antiadhesive activity against broad range of microbes. In the present study we investigated the production, purification and properties of key components of the cell-associated-biosurfactant (CABS) from Lactobacillus acidophilus NCIM 2903. Results: Extracted, purified, freeze-dried CABS shows reduction in surface tension (SFT) of phosphate buffer saline (PBS @pH 7.0) from 71 to 26 mN/m and had a critical micelle concentration (CMC) of 23.6 mg/mL. The CABS showed reduction in interfacial tension (IFT) against various hydrocarbons and had effective spreading capability as reflected through the decrease in contact angle (CA) on different surfaces (polydimethylsiloxane - PDMS, Teflon tape, glass surface, polystyrene film and OHP sheet). The anionic nature of CABS displayed stability at different pH and temperatures and formed stable emulsions. Thin layer chromatography (TLC) and Fourier transform infrared spectroscopy (FTIR) revealed CABS as glycolipoprotein type. The Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) showed presence of multiple bands in a molecular range of 14.4 to 60 kDa, with prominent bands of 45 kDa. The CABS has significant antiadhesion and antibiofilm activity against tested bacterial strains. Conclusion: The current challenging situation is to develop methods or search for the molecules that will prevent the formations of biofilm on medical bioimplants of PDMS based materials. These findings are supportive for the use of Lactobacilli derived BS as potential antiadhesive agent on various surfaces of biomedical devices. [ABSTRACT FROM AUTHOR]

Abstract: Aligned ZnO films of nanorods arrays were grown on Indium doped Tin oxide (ITO) glass substrate for the Dye Sensitized Solar Cells (DSSCs) applications. Two-step approach was employed for the deposition, which offers advantages such as excellent surface adhesion, large area deposition, high reproducibility and yield. Structural characterization using X-ray diffraction (XRD) shows a preferred c-axis (002) oriented growth. Scanning Electron Microscopy (SEM) images reveals uniformly distributed hexagonal ZnO nanorods with average diameter varying from 80 to 250 nm. Average growth rate of the films was estimated using Surface Profilometer which was found to be ∼1 μm/h. Optical characterizations were carried out using Photo-spectrometer and Raman spectroscopy. The DSSCs using these ZnO films of nanorods array as photo-electrodes show conversion efficiency ranging from 0.24 to −0.71 %, the maximum efficiency was obtained for films deposited for time duration 8 h. [Copyright &y& Elsevier]