Phytosynthesis of zinc oxide nanoparticles for enhanced antioxidant, antibacterial, and photocatalytic properties: A greener approach to environmental sustainability.

Multifunctional nanoparticles (NPs) production from phytochemicals is a sustainable process and an eco-friendly method, and this technique has a variety of uses. To accomplish this, we developed zinc oxide nanoparticles (ZnONPs) using the medicinal plant Tinospora cordifolia (TC). Instruments such as UV-Vis, XRD, FTIR, FE-SEM with EDX, and high-resolution TEM were applied to characterize the biosynthesized TC-ZnONPs. According to the UV-vis spectra, the synthesized TC-ZnONPs absorb at a wavelength centered at 374 nm, which corresponds to a 3.2 eV band gap. HRTEM was used to observe the morphology of the particle surface and the actual size of the nanostructures. TC-ZnONPs mostly exhibit the shapes of rectangles and triangles with a median size of 21 nm. The XRD data of the synthesized ZnONPs exhibited a number of peaks in the 2θ range, implying their crystalline nature. TC-ZnONPs proved remarkable free radical scavenging capacity on DPPH (2,2-Diphenyl-1-picrylhydrazyl), ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), and NO (Nitric Oxide). TC-ZnONPs exhibited dynamic anti-bacterial activity through the formation of inhibition zones against Pseudomonas aeruginosa (18 ± 1.5 mm), Escherichia coli (18 ± 1.0 mm), Bacillus cereus (19 ± 0.5 mm), and Staphylococcus aureus (13 ± 1.1 mm). Additionally, when exposed to sunlight, TC-ZnONPs show excellent photocatalytic ability towards the degradation of methylene blue (MB) dye. These findings suggest that TC-ZnONPs are potential antioxidant, antibacterial, and photocatalytic agents.

Definitions of sex and intimacy among gender and sexual minoritised groups in urban India.

Understandings of sex and intimacy carry important implications for individuals' behaviours and health. In many research studies, sex is narrowly defined as penile-vaginal intercourse, which may exclude the experiences of sexual and gender minoritised individuals. Likewise, sexual intimacy, or intimacy related to sexual experience between two or more people, is under-researched. Even less is known about how sexual and gender minoritised individuals in countries such as India understand these concepts. This qualitative study included focus group discussions and interviews conducted in three urban areas in India - Chennai, Bangalore and Kolkata. Data were analysed thematically. Participants described sex as a context-dependent experience, acknowledging that their definitions might not capture others' characterisations. Participants reported numerous barriers to intimacy, especially for transgender and other gender minority individuals. We discuss the implications of simplistic definitions related to gender and sexuality for future sexuality research and public health in settings such as those discussed here.

Diffusive and non-diffusive photo-induced proton coupled electron transfer from hydrogen bonded phenols to meso-tetrakis-5,10,15,20-pentafluorophenyl porphyrin.

Enhanced reductive fluorescence quenching of meso-tetrakis-5,10,15,20-pentafluorophenyl porphyrin (H2F20TPP) by two different phenols, 4-methoxy phenol (4-MeOPhOH) and 2,6-dimethoxy phenol (2,6-DiMeOPhOH) in the presence of various pyridine bases in dichloromethane solution is studied using steady state and time resolved fluorescence spectroscopic methods by employing time correlated single photon counting (TCSPC) and fluorescence up-conversion techniques. An enhanced quenching behaviour of H2F20TPP is observed when phenols are hydrogen bonded to various pyridine bases. Quenching observed in the steady state and time resolved studies in the nanosecond time domain follows second order kinetics and generates quenching rate constants and hydrogen bond equilibrium constants, the latter of which agree quite closely with those obtained from independent spectroscopic measurements. A significant kinetic deuterium isotope effect is observed, indicating the importance of proton movement in the quenching processes. This quenching effect is attributed to be due to a tri-molecular transition state involving H2F20TPP and a hydrogen bonded phenol complex, in which electron transfer from phenol to excited H2F20TPP is concerted with proton movement from the phenol to hydrogen bonded base. Observed quenching behaviours are rationalized by invoking diffusion controlled proton coupled electron transfer. Fluorescence up-conversion studies in the 100 ps time domain confirm ultrafast PCET for 4-MeOPhOH and base pairs which fall in a non-diffusive regime.

Synthesis, relaxometric and photophysical properties of a new pH-responsive MRI contrast agent: the effect of other ligating groups on dissociation of a p-nitrophenolic pendant arm.

Two gadolinium(III) chelates, GdNP-DO3A (1-methlyene-(p-NitroPhenol)-1,4,7,10-tetraazacycloDOdecane-4,7,10-triAcetate) and GdNP-DO3AM (1-methlyene(p-NitroPhenol)-1,4,7,10-tetraazacycloDOdecane-4,7,10-triacetAMide), containing a single nitrophenolic pendant arm plus either three acetate or three amide pendant arms were synthesized and characterized. The properties of the gadolinium, terbium, and dysprosium complexes of these ligands were examined as a function of pH. The extent and mechanism of the changes in water relaxivity with pH of each gadolinium complex was found to differ substantially for the two complexes. The water relaxivity of Gd(NP-DO3A) increases from 4.1 mM(-1) s(-1) at pH 9 to 7.0 mM(-1) s(-1) at pH 5 as a result of acid-catalyzed dissociation of the nitrophenol from the lanthanide. The nitrophenol group in Gd(NP-DO3AM) does not dissociate from the metal center even at pH 5; therefore, the very modest increase in relaxivity in this complex must be ascribed to an increase in prototropic exchange rate of the bound water and/or phenolic protons.