A [2]pseudorotaxane-based mechanised nanoparticle system, which operates within an aqueous acidic environment, has been prepared and characterised; this integrated system affords both water-soluble stalk and ring components in an effort to improve the biocompatibility of these promising new drug delivery vehicles.

Herein, a pH-sensitive probe has been designed based on DNA modified gold nanoparticles (AuNPs) for Raman/fluorescence dual-imaging of the intracellular pH distribution. In the acidic environment of cancer cells, the configuration change of DNA on the probe surface could turn "on" Raman/fluorescence signals simultaneously.

In this communication, we report that ionizable, tertiary amine-based block copolymers can be used as pH-responsive contrast agents for magnetic resonance imaging (MRI) through the chemical exchange saturation transfer (CEST) mechanism. The CEST signal is essentially "off" when the polymers form micelles near physiological pH but is activated to the "on" state when the micelles dissociate in an...

We report that Fe3O4 nanoparticles are able to catalyse lipid peroxidation in liposomes at acidic but not neutral pH. The oxidation is dependent on either pre-existing lipid peroxides or hydrogen peroxide as a substrate. This is the first evidence for metal oxide nanoparticles as peroxidase mimetics oxidising biomolecules in a relevant environment.

Acid/base transporters play a key role in establishing an acidic luminal environment for sperm maturation and storage in the male reproductive tract. Impairment of the acidification capacity of the epididymis, via either genetic mutations or exposure to environmental factors, may have profound consequences on male fertility.

Bauxite formation is usually possible in humid and tropical weather conditions with the enrichment of minerals containing Al2O3 environment. These are found chemical compositions that rich major trace elements, REEs. Karst-type bauxites have different characteristics terms REE elements since they undergo alteration processes. Various correlations can be evaluated using geostatistical methods to...

A self-quenched zinc(II) phthalocyanine dimer linked with an acid-sensitive ketal unit has been prepared, which can be activated in an acidic environment (pH = 5.0-6.5) as a result of the cleavage of the ketal linker and separation of the phthalocyanine units, resulting in enhanced fluorescence emission and singlet oxygen production.

Oxygen reduction reaction (ORR) over a carbonaceous catalyst (1) with a phosphinate (>P(=O)OH) moiety was explored computationally. Under the acidic environment of a fuel cell, 1 could be active for ORR and be converted to 2 with a >P(OH)(2) moiety. An edge phosphinate could be active for both 2- and 4-electron ORR.

The interaction of pertussis toxin (PT) with cells and model membranes was investigated by examining PT-induced intoxication of Chinese hamster ovary cells and by studying the binding of PT and its subunits to phospholipid vesicles. Since certain bacterial toxins require an acidic environment for efficient interaction with membranes and subsequent entry into the cell, the requirement for an aci...