It is known that bulk ZnO is a nonmagnetic material. However, the electronic band structure of ZnO is severely distorted when the ZnO is in the shape of a very thin plate with its dimension along the c-axis reduced to a few nanometers while keeping the bulk scale sizes in the other two dimensions. We found that the chemically synthesized ZnO nanoplates exhibit magnetism even at room temperature. First-principles calculations show a growing asymmetry in the spin distribution within the distorted bands formed from Zn (3d) and O (2p) orbitals with the reduction of thickness of the ZnO nanoplates, which is suggested to be responsible for the observed magnetism. In contrast, reducing the dimension along the a-or b-axes of a ZnO crystal does not yield any magnetism for ZnO nanowires that grow along c-axis, suggesting that the internal electric field produced by the large {0001} polar surfaces of the nanoplates may be responsible for the distorted electronic band structures of thin ZnO nanoplates.

γ-Aminobutyric acid-enriched sea tangle extract was obtained from the fermentation of Lactobacillus brevis BJ-20. The fermented sea tangle extract (FST) was separated into three fractions by molecular weight: FST I (greater than 10 kDa), FST II (1-10 kDa), and FST III (less than 1 kDa). The anti-inflammatory characteristics of the FST fractions were investigated by measuring the production of nitric oxide (NO) and the expression levels of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)induced mouse macrophage (RAW 264.7) cells. Both NO production and iNOS expression levels were significantly inhibited by FST treatments in a dose-dependent manner. FST III was the most effective inhibitor of processes. This demonstrates that the effect of FST on LPS-induced inflammation might be closely correlated with the inhibition of inflammatory cytokine expression.

Over the past several decades, the design of highly active and cost-effective catalysts and electrocatalyst has been the subject of intense research efforts.to However, there has been significantly less deliberate emphasis on rationally designing a catalyst system with a prolonged stability. A major obstacle comes from the ambiguity behind how catalyst degrades. Several degradation mechanisms have been proposed in literature, such as catalyst particles detachment of the substrate, metal atom dissolution, agglomeration, Ostwald ripening, or corrosion of the carbon support, but with a lack of systematic studies, the causal relations between degradation and these proposed mechanisms remain ambiguous. Here, we report a systematic study of a catalyst system comprising of small particles and single atoms of Pt sandwiched between graphene layers, GR/Pt/GR where Pt-specific catalysis occurs through “chemically transparent” outer Gr layer(s). Experimental and computational analyses unravel the degradation mechanism of the studied electrocatalyst architecture for oxygen reduction reaction in acidic medium. Catalyst suffers from atomic dissolution under ORR harsh acidic and oxidizing operation voltages. Single atoms trapped in point defects within the top graphene layer on their way hopping through towards the surface of GR/Pt/GR architecture. Trapping mechanism renders individual Pt atoms as single atom catalyst sites catalyzing ORR for thousands of cycles before washed away in the electrolyte. The GR/Pt/GR catalysts also compare favorably to state-of-the-art commercial Pt/C catalysts and demonstrates a rational design of a hybrid nanoarchitecture with a prolonged stability for thousands of operation cycles. The proposed Gr/metal/Gr architecture is not only applicable to other electrocatalytic reactions but can have several applications in sensors and biomedical fields.