Combined effect of polystyrene nanoparticles and chlorpyrifos to Daphnia magna.

Microplastics and nanoplastics (MPs/NPs) are emerging contaminants ubiquitous in the environment. These particles can act as carriers of hydrophobic organic compounds (HOCs), such as chlorpyrifos (CPF), an organophosphorus insecticide. This study investigates the acute toxicity of CPF combined with model polystyrene nanoplastics (PS-NPs) using Daphnia magna as a model organism.

Light-Quality-Adapted Carotenoid Photoprotection in the Photosystem of .

The photosystem of filamentous anoxygenic phototroph (.) comprises a light-harvesting (LH) complex encircling a reaction center (RC), which intensely absorbs blue-green light by carotenoid (Car) and near-infrared light by bacteriochlorophyll (BChl). To explore the influence of light quality (color) on the photosynthetic activity, we compared the pigment compositions and triplet excitation dynamics of the LH-RCs from .

Daphnia magna uptake and excretion of luminescence-labelled polystyrene nanoparticle as visualized by high sensitivity real-time optical imaging.

The environmental and ecological consequences of nanoplastics (NPs) draw increasing research interests and social concerns. However, the in situ and real-time detection of NPs from living organisms and transferring media remains as a major technical obstacle for scientific investigation. Herein we report a novel time-gated imaging (TGI) strategy capable of real-time visualizing the intake of NPs by an individual living organism, which is based on the polystyrene NPs labelled with lanthanide up-conversion luminescence.

as a model to study the ecotoxicity of 1-alkyl-3-methylimidazolium bromide.

The purple non-sulfur bacterium was selected as a biological model to investigate its response to the toxicity of 1-alkyl-3-methylimidazolium bromide ([Cmim]Br), a type of ionic liquid (IL), with different alkyl chain lengths ( describes the number of carbon atoms in the alkyl chain). The inhibition of bacterial growth by [Cmim]Br was positively correlated with . Morphological characterization revealed that [Cmim]Br caused cell membrane perforation.

Photoinduced chlorophyll charge transfer state identified in the light-harvesting complex II from a marine green alga .

The light-harvesting complex II of (-LHCII), a green alga, differs from that of spinach (-LHCII) in chlorophyll (Chl) and carotenoid (Car) compositions. We investigated ultrafast excitation dynamics of -LHCII with visible-to-near infrared time-resolved absorption spectroscopy. Absolute fluorescence quantum yield ( ) of LHCII and spectroelectrochemical (SEC) spectra of Chl and were measured to assist the spectral analysis.

A Possible Mechanism for Aggregation-Induced Chlorophyll Fluorescence Quenching in Light-Harvesting Complex II from the Marine Green Alga .

The light-harvesting complex II of a green alga (-LHCII) is peculiar in that it contains siphonein and siphonaxathin as carotenoid (Car). Since the S state of siphonein and siphonaxathin lies substantially higher than the Q state of chlorophyll (Chl ), the Chl (Q)-to-Car(S) excitation energy transfer is unfeasible. To understand the photoprotective mechanism of algal photosynthesis, we investigated the influence of temperature on the excitation dynamics of -LHCII in trimeric and aggregated forms.

Promotion effects of flavonoids on browning induced by enzymatic oxidation of tyrosinase: structure-activity relationship.

Tyrosinase, widely distributed in nature, is a copper-containing polyphenol oxidase involved in the formation of melanin. Flavonoids are most often considered as tyrosinase inhibitors but have also been confirmed to be tyrosinase substrates. Four structure-related flavonoids including flavones (apigenin and luteolin) and flavonols (kaempferol and quercetin) are found to promote not inhibit browning induced by tyrosinase catalyzed oxidation both in model systems and in mushrooms under aerobic conditions.

Spatial effects of photosensitization on morphology of giant unilamellar vesicles.

Singlet oxygen (O) formed through photosensitization may initiate oxidative destruction of biomembranes, however, the influence from the spatial organization of photosensitizers (PS) relative to membranes remains unclear. To clarify this issue, we loaded riboflavin 5'-(dihydrogen phosphate) monosodium (FMN-Na) as a hydrophilic PS into the lumen of halloysite nanotubes (HNTs), and attached the nanoassemblies (FMN-Na@HNTs), via Pickering effects, to the outer surfaces of giant unilamellar vesicles (GUVs) of phospholipids. We also prepared GUVs dopped with lumiflavin (LF) as a lipophilic PS having a O quantum yield comparable to FMN-Na.

Naturally occurring nanotube with surface modification as biocompatible, target-specific nanocarrier for cancer phototherapy.

Phototherapy has drawn increasing attention including the use of nanocarriers with high drug loading capacity and delivery efficacy for target-specific therapy. We have made use of naturally-occurring halloysite nanotubes (HNTs) to build a biomimetic nanocarrier platform for target-specific delivery of phototherapeutic agents. The HNTs were decorated with poly(sodium-p-styrenesulfonate) (PSS) to enhance the biocompatibility, and were further functionalized by lumen loading the type-II photosensitizer indocyanine green (ICG).