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The investigation delves into the functionality exhibited by ferroelectric BiFe0.95Mn0.05O3 (BFM) nanoparticles (NPs) concerning the hydrogen evolution reaction (HER). The electrocatalytic activity of BFM NPs undergoes a transformative shift as a consequence of mono‐, di‐, and tri‐valent cation substitution. Notably, the strategic engineering of doping at the Bi site within BFM NPs yields a remarkable outcome, namely the conspicuous reduction of the kinetic overpotential prerequisite for HER. This diminished overpotential in doped BFM NPs arises from the confluence of multifarious factors: diminished charge transfer resistance, augmented specific surface area, a discernible distribution of pore sizes ranging from narrow to broad, particles endowed with a shape boasting abundant active facets, and the integration of dopants as novel active sites on the surface. Furthermore, the presence of surface defects, oxygen vacancies, and amplified microstrain within doped BFM NPs contributes to the reduction in overpotential. [ABSTRACT FROM AUTHOR]

2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a is a second‐generation, lipophilic, chlorin‐based photosensitizer currently used for various types of solid cancer including breast, esophageal, neck, and head cancer, etc. The aim of the present work was to develop a sensitive and robust reversed‐phase–high‐performance liquid chromatography–ultraviolet detection method for the determination of 2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a to explore in vitro‐based applications including encapsulation, loading, drug release, and stability studies, and also could be utilized for the selective analysis of 2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a from developed lipid polymer hybrid nanoparticle. The developed reversed‐phase–high‐performance liquid chromatography–ultraviolet detection method was validated in terms of linearity, accuracy, precision, stability, and robustness as per standard guidelines. The developed method exhibited linearity ranging from 50 to 2000 ng/ml with an R2 value of 0.999. The limit of detection and limit of quantitation value of the developed method was found to be 14.03 and 42.80 ng/ml, respectively. Also, degradation studies revealed that 2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a degraded quickly under basic conditions compared to other stability conditions (i.e., acidic, oxidative, temperature, etc.). Furthermore, the developed drug‐loaded lipid polymer hybrid nanoparticle showed an average size of 123.03 nm (polydispersity index = 0.253) with an encapsulation efficiency of 70.23%. Cell cytotoxicity assay of lipid polymer hybrid nanoparticle showed significant cancer cell death equivalent to 2‐fold higher than the free drug. In conclusion, the developed reversed‐phase–high‐performance liquid chromatography–ultraviolet detection analytical method was found to be sensitive and reliable for the determination of free 2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a and 2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a content in loaded lipid polymer hybrid nanoparticle. Thereby, opening the avenues for future research to explore the detailed physiochemical and formulation designing for the 2‐[1‐hexyloxyethyl]‐2‐devinyl pyropheophorbide‐a. [ABSTRACT FROM AUTHOR]

The ferroelectricity of multivalent codoped Bismuth ferrite (BiFeO3; BFO) nanoparticles (NPs) is revealed and utilized for photocatalysis, exploiting their narrow electronic bandgap. The photocatalytic activity of ferroelectric photocatalysts BiFe0.95Mn0.05O3 (BFM) NPs and mono‐, di‐, or tri‐valent cations (Ag+, Ca2+, Dy3+; MDT) coincorporated BFM NPs are studied under ultrasonication and in acidic conditions. It is found that such doping enhances the photocatalytic activity of the ferroelectric NPs approximately three times. The correlation of the photocatalytic activity with structural, optical, and electrical properties of the doped NPs is established. The increase of spontaneous polarization by the mono‐ and tri‐valent doping is one of the major factors in enhancing the photocatalytic performance along with other factors such as stronger light absorption in the visible range, low recombination rate of charge carriers, and larger surface area of NPs. A‐site doping of BFO NPs by divalent elements suppresses the polarization, whereas trivalent (Dy3+) and monovalent (Ag+) cations provide an increase of polarization. The depolarization field in these single domain NPs acts as a driving force to mitigate recombination of the photoinduced charge carriers. [ABSTRACT FROM AUTHOR]

Mesoporous nanoparticles have a larger surface area and therefore, suitable for dye‐sensitised solar cells and photocatalytic applications. This Letter presents the analysis of solvothermal derived as‐prepared TiO2 and doped TiO2 nanocrystals by utilising acetone as the solvent. The as‐prepared and doped TiO2 nanoparticles endorsed the presence of anatase phase along with the slightly deviated diffraction peaks with the reduced crystallite size as a result of doping. Surface morphology analyses evidenced the mesoporous microspheres of nanoparticles, whereas the stoichiometry study exhibited the elementary peaks in the as‐prepared and doped samples. The estimated optical bandgaps are found to be 2.68, 2.92, 2.48 and 2.88 eV in accordance with the doped TiO2 with copper, tin, barium and zinc–magnesium as compared to 3.16 eV of TiO2. Doped samples evidenced the enhanced scattering capability, whereas tin and zinc–magnesium co‐doped samples demonstrated the highest diffuse reflectance in a broad wavelength range from 550 to 800 nm. [ABSTRACT FROM AUTHOR]

This Letter reports the synthesis of nanoceramic composite ZnAl2O4TiO2 by using a cost‐effective and straight forward sol–gel route. X‐ray diffraction (XRD) showed the ZnAl2O4 cubic structure along with the mixed anatase‐ and rutile‐phases of TiO2. Rietveld refinement is performed using XRD pattern to study the structural parameters. Raman investigation endorsed the corresponding vibration peaks of TiO2 and ZnO. Field‐emission scanning electron microscopy evidenced the agglomerated spherical nanoparticles. Energy‐dispersive spectroscopy analysis demonstrated the elementary peaks of Zn, Al, and Ti at 4.5, 1.5, and 1 eV, respectively. LCR measurement revealed the decreased dielectric permittivity with the rise in frequency and temperature. This dielectric characteristic is attributed to the dipole movement of the charge carriers. Furthermore, the authors present the investigation of the conductivity and impedance of the prepared dielectric ceramic material. [ABSTRACT FROM AUTHOR]

Biomass burning (BB) is an important global source of aerosol and trace gases that degrade air quality, decrease visibility, and impact climate and human health. Refractory black carbon (rBC), brown carbon (BrC), and organic aerosol are major components of BB emissions. BB aerosol composition is highly variable at the source and depends on fuel composition and combustion phase. Atmospheric aging alters fresh BB aerosol through processes that are complex and dynamic. To better understand the variability in optical properties, we report fresh aerosol laboratory measurements from burning southwestern U.S. fuels and compare them to aged ambient BB aerosol from wildfires over a range of atmospheric time scales. Our BB aerosol analysis uses the relationship between the absorption Ångström exponent and single‐scattering albedo (SSA) to identify rBC, BrC, and organic aerosol‐dominated regimes that are defined using Mie theory. This model framework is used to interpret the large variability in optical properties measured in laboratory burns. In contrast, we find the observed absorption Ångström exponent‐SSA relationship for ambient BB aerosol to be less variable and more clustered together with increased atmospheric aging. This transition from fresh to aged behavior is attributed to the homogenization of the BB aerosol from mixing and aging over several hours. Finally, BB aerosol in ambient fire plumes that have aged for several hours exhibits larger SSAs than laboratory flaming burns. We conclude that BrC/OC mixtures play a larger role than rBC in the positive climate forcing of BB aerosol than what would be projected from laboratory results. Key Points: A semiempirical Mie theory framework can be used to classify the chemical composition of biomass burning aerosol by optical propertiesSmoke optical properties in aged ambient fire plumes are more clustered and less variable than fresh laboratory burns due to mixing and agingAerosols from ambient fires are shifted toward the brown carbon and organic carbon mixing regime relative to those from laboratory fires [ABSTRACT FROM AUTHOR]

Abstract: Nanoparticles (NPs) of PTFE (polytetrafluoroethylene) in suspension form were reported as very efficient extreme pressure (EP) additive in 150 N API Group II oil in our earlier work. The less stability of a nanosuspension due to agglomeration of NPs beyond 3 wt%, however, was a major issue, which needed to be addressed for its possible industrial exploitation in lubricants. Using another additive, eg polyisobutylene succinimide (PIBSI), as a dispersant appeared to be a plausible solution. Its inclusion (1 wt%) increased the stability of the oil by a factor of 4. It was necessary to investigate, however, whether it influenced other properties synergistically or antagonistically. The present paper highlights the positive and negative aspects of inclusion of PIBSI on the tribo‐performance (EP and anti‐wear) of the nano‐PTFE‐based oils. A series of nano‐PTFE oils (1%‐6%) stabilised with PIBSI (1%) were developed and evaluated for EP and anti‐wear performance. The PIBSI‐PTFE combination clearly showed antagonistic behaviour due to competition for film formation on the surfaces. However, with an increase in concentration of NPs, the film formation mechanism was dominated by them. Scanning electron microscopy, atomic force microscopy, and X‐ray photoelectron spectroscopy were used for the examination of the topography and surface chemistry of the protective films formed on the steel specimens. [ABSTRACT FROM AUTHOR]

Abstract: Betulinic acid (BA), a naturally occurring plant‐derived pentacyclic triterpenoid, has gained attention in recent years owing to its broad‐spectrum biological and medicinal properties. Despite the pharmacological activity of BA, it has been associated with some drawbacks, such as poor aqueous solubility and short half‐life in vivo, which limit therapeutic application. To solve these problems, much work in recent years has focused on enhancing BA's aqueous solubility, half‐life, and efficacy by using nanoscale drug delivery systems. Several different kinds of nanoscale delivery systems—including polymeric nanoparticles, magnetic nanoparticles, liposomes, polymeric conjugates, nanoemulsions, cyclodextrin complexes, and carbon nanotubes—have been developed for the delivery of BA. Here, we focus on the recent developments of novel nanoformulations used to deliver BA in order to improve its efficacy. [ABSTRACT FROM AUTHOR]

BACKGROUND: As a result of evolution of multiple drug resistance in human pathogens (bacteria) there is increasing demand for novel antibacterial agents, and recently, due to their high antibacterial and catalytic activities, metal nanoparticles have attracted the attention of researchers and medical microbiologists worldwide. RESULTS: Ni-, Ce- and Ag-doped MnO2 nanoparticles were synthesized by a co-precipitation method. Antibacterial activity of these synthesized nanoparticles on methicillin-resistant Staphylococcus aureus and lead-resistant Pseudomonas aeruginosa strain 4EA was investigated using a disc diffusion method. Only Ag-doped MnO2 nanoparticles showed an antibacterial property against methicillin-resistant Staphylococcus aureus and lead-resistant Pseudomonas aeruginosa strain 4EA at low levels of 60 µg/disc and 85 µg/disc, respectively. Scanning electron microscopy and transmission electron microscopy (SEM-TEM) coupled with energy dispersive X-ray (EDX) analysis revealed the nano-size and composition of these synthesized nanoparticles. CONCLUSION: It was confirmed through a disc diffusion method that chemically synthesized silver doped MnO2 nanoparticles have antibacterial activity against multidrug-resistant Staphylococcus aureus and lead-resistant Pseudomonas aeruginosa strain 4EA at low levels therefore these nanoparticles can be employed to fight and prevent infections caused by multidrug-resistant bacterial pathogens. © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this work, the cubic spinel manganese‐zinc ferrite nanoparticle is synthesized by the sol–gel auto combustion method. It is the simple chemical route and low‐cost method for the formation of manganese zinc ferrite nanoparticles. Structural and morphological studies of the synthesized manganese‐zinc ferrite nanoparticles are done by X‐ray diffraction, Fourier transform infrared spectroscopy (FTIR), and scanning electron microsccopy (SEM). The X‐ray diffraction results indicate that the ferrite sample has a cubic spinel type structure with Fd3m space group. The average crystallite size of the synthesized manganese zinc ferrite nanoparticles is found to be 34 nm as determined by Debye–Scherrer equation. Two well‐known absorption bands at 467 and 558 cm−1, in FTIR spectroscopy data also confirm the cubic spinel structure in the prepared samples. Morphological studies by SEM exposed formation of largely agglomerated and well‐defined nanoparticles of the sample. From the magnetization data, parameters like magnetization, coercivity, remanance magnetization, and squareness ratio are calculated. [ABSTRACT FROM AUTHOR]