Depolarization of few-layer III-V and II-VI materials through symmetric rumpling.

It is generally believed that few-layer films of wurtzite materials remove the destabilizing dipole by converting to a flat hexagonal structure. However, using first-principles calculations, we demonstrate that contrary to the existing consensus these few-layer hexagonal films exhibit a small symmetric rumpling and are not perfectly flat. We then perform a systematic study of the rumpling behavior of a range of few-layer III-V and II-VI films.

Facile surface functional polyetheretherketone with antibacterial and immunoregulatory activities for enhanced regeneration toward bacterium-infected bone destruction.

Existing biologically inert or unmodified implants to treat infectious bone defects or osteomyelitis still cannot effectively solve bacterial infection and osseointegration. In this work, a simple co-deposition strategy was developed to modify porous polyetheretherketone (PEEK) with improved antibacterial activity and controllable immunoregulatory ability. After PEEK was treated by HSO to obtain porous PEEK (SPEEK), the self-polymerization of dopamine was operated on SPEEK in the solution of dopamine and gentamicin sulfate (GS) to prepare polydopamine (pDA) and GS layer-modified SPEEK (labeled as SPEEK-pDA-GS).

Antibacterial activity of positively charged carbon quantum dots without detectable resistance for wound healing with mixed bacteria infection.

Widespread bacterial infection and the spread of antibiotic resistance exhibit increasing threat to the public and thus require new antibacterial strategies. Carbon quantum dots (CQDs) have been extensively investigated to play fluorescent, catalytic roles and even potential biomedical functions containing sterilization. However, synthetic understanding of the interaction of CQDs and bacteria, the exhibition of antibacterial ability, and the risk of resistance evolution remain lacking.

Rapid construction of polyetheretherketone (PEEK) biological implants incorporated with brushite (CaHPO·2HO) and antibiotics for anti-infection and enhanced osseointegration.

Polyetheretherketone (PEEK) is an ideal implant material for orthopedic and dental application due to its high biocompatibility and mechanical property. However, biological inertness of PEEK hinders the effective clinical applications in treating bone defect, especially in the situation accompanied by bacterial infection. In this study, a layer-by-layer (LBL) deposition method with controlled cycles was developed to rapidly construct brushite (CaHPO·2HO) (CaP) layers containing gentamicin sulfate (GS) on PEEK to obtain CaP-and-GS modified PEEK, named as PEEK/CaP-GS.

Peculiar bond characters of fivefold coordinated octet compound crystals.

The present work exemplifies complementary perspectives offered by the band and bond pictures of solids, with an emphasis on the chemical intuition pertaining to the latter, especially in the presence of interfaces. The modern computational method of constructing a unique set of maximally localized Wannier functions from delocalized band states imparts new interpretations to the familiar concept of chemical bonds in the context of crystalline solids. By bridging the band and bond pictures using advanced computational tools, we reveal for the first time the unusual bond characters of a long-predicted fivefold coordinated structure of binary octet compounds A B consisting of AA' stacked planar AB honeycombs.