Silver-Nanoparticle-Embedded Short Amphiphilic Peptide Nanostructures and Their Plausible Application to Reduce Bacterial Infections

The microbiota-gut-brain axis (GBA) plays a critical role in the development of neurodegenerative diseases. Dysbiosis of the intestinal microbiome causes a significant alteration in the gut microbiota of Alzheimer's disease (AD) patients, followed by neuroinflammatory processes. Thus, AD beginning in the gut is closely related to an imbalance in gut microbiota, and hence a multidomain approach to reduce this imbalance by exerting positive effects on the gut microbiota is needed. In one example, a tyrosine-based short peptide amphiphile (sPA) was used to synthesize antibacterial AgNPs−sPA nanostructures. Such nanostructures showed high biocompatibility and low cytotoxicity, and therefore work as model drug delivery agents for addressing local bacterial infections. These may have therapeutic value for the treatment of microbiota-triggered progression of neurodegenerative diseases.     

Catalytic-assisted synthesis, characterization and low frequency AC conduction of nanostructured conducting polyaniline

Polymerizations of aniline at the reaction temperatures of 25 and 50 °C have been performed in the presence of iron catalyst. The prepared conducting polyaniline at different reaction periods was investigated for physicochemical and electrical properties, through X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR) and frequency-dependent electrical conductivity measurements, respectively. XRD studies established the improved nanostructured crystalline nature for the polymer prepared at 50 °C. Size of the particles ranging from 10 to 20 nm was calculated for the prepared polyaniline. SEM analysis shows the cauliflower-like morphology for optimized reaction temperature. The study further establishes the attainment of uniform distribution of polyaniline at the reaction temperature of 50 °C. The charge transitions between benzenoid (B-band) and quinonoid (Q-band) bands were witnessed by UV–Vis spectrum analysis. The band gap analysis revealed the narrow band gap direct transition semiconducting nature of the conducting polymer. Quinonoid and phenylene rings were identified through vibrational bands between 1570 and 827 cm^?1 via FTIR spectroscopy analysis. The AC conductivity of the sample synthesized at 50 °C showed 1.50 × 10^?1 S cm^?1. Enhancement in conductivity with increasing temperature represented the improved crystalline nature of the polyaniline prepared at 50 °C.     

Temperature Dependence of Ionic Conductivity of Ceria Electrolyte at Concentrated Range of Multiple Doping

We study ionic conductivity of heavily doped ceria, doping level close to 50 mol% with multiple lanthanides in the temperature range of 200°C–500°C. The doped ceria is found to be single fluorite phase, where unit cell is dilated to 0.5527 nm, compared with pure ceria (0.5422 nm). Electrical characterization by impedance spectroscopy reveals that sample sintered at lower temperature (1400°C) has consistently higher bulk conductivity compared to sample sintered at higher (1600°C) temperature, throughout the temperature range studied. Activation energy for oxygen vacancy diffusion is close to 1 eV, indicating lesser association of defects with the dopants compared with other heavily doped ceria reported in literature (activation energy ~1.4 eV). The best ionic conductivity is found to be 1.58 × 10^?3 S/cm at 500°C, which is much higher compared with heavily doped ceria reported in literature.     

IONIC MASS TRANSFER IN THREE-PHASE FLUIDIZED BEDS IN THE PRESENCE OF DISC PROMOTERS

Three-phase fluidized beds have wide applications in process industries. The present investigation is carried out to identify the enhancement of ionic mass transfer coefficients due to the presence of a disc promoter in a three-phase fluidized bed. A diffusion-controlled electrode reaction—reduction of ferricyanide ion—was employed to obtain mass transfer coefficient data. The mass transfer coefficient data were obtained by varying the geometric variables of the disc promoter (disc diameter, disc spacing) and dynamic variables (superficial liquid velocity, superficial gas velocity). The effect of particle diameter was also investigated. The investigations revealed that the mass transfer coefficients were enhanced with decreased disc spacing, increased disc diameter, increased superficial gas velocity, increased superficial liquid velocity, and increased particle diameter.     

SELECTIVE OXIDATION OF ALCOHOLS BY REDOX MOLECULAR SIEVES

High-throughput synthesis and screening of libraries consisting of redox zeolites and molecular sieves have been developed for the selective oxidation of 2-butyl-5-hydroxymethyl-imidazole to the corresponding aldehyde in the liquid phase. Libraries consisting of 96 catalysts were prepared and screened for catalytic activity using high-throughput software, robotics, reactor, and screening technologies. The integrated synthesis and screening workflow allowed ∼5000 samples to be screened in less than one month. Promising hits identified in the high-throughput primary screens were successfully scaled up and optimized in conventional laboratory test units. Best results have been obtained with doubly or triply doped mesoporous sieves containing both an impregnated and framework-substituted metal. PtBi-doped framework-substituted V-MCM-41 redox mesoporous sieves were found to be efficient catalysts for aerobic oxidation under relatively mild reaction conditions (100-150°C, 15-400 psi air, 4-10 h reaction time). MIBK/H₂O/t-BuOH mixtures were identified as efficient solvent systems for this reaction. Isolated yields confirm high selectivities of more than 90% with quantitative conversions. Spent catalysts were shown to be fully regenerable by high temperature calcination in air.     

Powdered activated carbon coated hollow fiber membrane: Preliminary studies on its ability to limit membrane fouling and to remove organic materials

A new approach to a membrane hybrid system by pre-coating the hollow fiber membrane with powdered activated carbons (PAC) was evaluated for its ability to minimize the fouling of the membrane and to remove organic material from wastewater. This preliminary study evaluates the performance of a microfiltration membrane coated with three kinds of PACs: wood based (WB), charcoal based (CB) and coconut based (HA). Broadly, two scenarios were evaluated: one with low amounts of PAC coated on the membrane and another at higher amounts of PAC coating. The results indicate that the pre-coated membrane can effectively arrest the fouling agents in the wastewater in reaching the membrane pores and thereby limit membrane fouling. Interestingly, it was also found that, without any pre-treatment or addition of PAC in the tank, the pre-coated membrane also had the ability to retain organic materials. For the hollow fiber microfilter membrane used in the study having surface area of 2.58×10^-03 m² surface area, pre-coating the membrane individually with 458 mg of HA-PAC, 497 mg of WB-PAC and 906 mg CB-PAC, the reduction in permeate flux was as little as 14–20% after 8 hours of each operation and the maximum organic removals was about 76%, for all the three kinds of PAC coatings. The type of PAC coated on the membrane and the amount coated could be the key factors in deciding the performance of the system. Although further studies are required, it is evident that the PAC pre-coated membrane system has great potential in successfully reducing membrane fouling, which could improve membrane life, enhance process performance and reduce membrane cleaning time.     

Computer vision based interface level control in separation cells

The major impediment in controlling the interface between Bitumen-froth and Middlings in separation cells is the lack of safe and reliable sensors for interface level detection. This work describes a novel sensor for this problem using computer vision techniques on video frames captured from a sight glass camera. A simple edge detection method combined with state-space model based particle filtering is used to estimate the interface level and its quality. Industrial results show that the algorithm is robust to lighting changes and process abnormalities. Highly improved control performance results when the sensor estimates are used for feedback control.     

The electrical,magnetic and 57Fe Mössbauer studies of Al doped PrFeO3 polycrystalline materials

The structural, electrical, magnetic and ⁵⁷Fe Mössbauer studies of sol-gel synthesized polycrystalline Pr_1-xAl_xFeO₃ (x?=?0, 0.1, 0.2, 0.3, 0.4 and 0.5) samples are reported in this paper and the phase purity of the materials was confirmed from Rietveld refinement of XRD pattern. From the magnetization studies it is observed that the Al doping at Pr site changed the magnetic ordering of the system at both room and low temperatures. The observed isomer-shift values from room temperature Mössbauer spectroscopy confirmed the charge state of the Fe ions and magnetic ordering in the compounds. Leakage current is observed to decrease with Al doping in the present work. From the leakage current density (J-E) measurements, it is observed that the space charge limited conduction (SCLC) dominates the conduction in lower and higher field regions for all the samples.     

Sulfosuccination of Methyl Ricinoleate and Methyl 12-Hydroxy Stearate Derived from Renewable Castor Oil and Evaluation of Their Surface Properties

Sulfosuccination of castor oil-derived methyl ricinoleate and methyl 12-hydroxy stearate have been carried out in the present work. Synthesis involves malenization of secondary alcohol of methyl ricinoleate/methyl 12-hydroxy stearate followed by sulfonation of maleic monoester to generate double-headed dianionic surfactant with carboxylate and sulfosuccinate functionalities in the head group region. Various reaction conditions were optimized for maximum production of these two sulfosuccinates. Both compounds were evaluated for surface and detergency properties. The surface tension study indicated that the critical micelle concentration of sulfosuccinated methyl ricinoleate and methyl 12-hydroxy stearate is 0.26 and 0.11 mM, respectively. The detergency property of these two surfactants indicated that they were excellent in wetting time emulsification and Ca-tolerance. However, these two surfactants exhibited very poor foam height and foam stability.     

Amelioration of electrochemical and photovoltaic performances on P(VP‐co‐VAc) based gel polymer electrolyte by incorporating double salt for dye‐sensitized solar cells

Dye‐sensitized solar cell (DSSC) is an alternative photovoltaic application used to replace the liquid electrolyte dependent conventional photovoltaic cell. In this research, gel polymer electrolyte (GPE) was used to replace the unstable liquid electrolyte. This GPE consists of poly[1‐vinylpyrrolidone‐co‐vinyl acetate] (P[VP‐co‐VAc]), tetrabutylammonium iodide (TBAI), sodium iodide (NaI), iodine (I₂), ethylene carbonate (EC), and propylene carbonate (PC). The GPE was tested for its ionic conductivity and an optimum level was reached at sample with 30% TBAI and 6% NaI at 1.17 × 10^?3 S cm^?1. The DSSC was then fabricated with all GPEs and a photovoltaic performance study was conducted. As a result, the highest photovoltaic conversion efficiency (PCE), η for a single salt was 3.04% for 40% TBAI. When a second salt is added, the system showed improvement in efficiency, η to 4.54% with short circuit current density, J_sc of 11.02 mA cm^?2 and open circuit voltage, V_oc of 0.67 V and FF of 61%. The other changes after the addition of TBAI and NaI salts have been observed through X‐ray diffraction, Fourier transformation and thermal analysis studies. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43805.