High-efficiency Electroreduction of O2 into H2 O2 over ZnCo Bimetallic Triazole Frameworks Promoted by Ligand Activation.

Co-based metal-organic frameworks (MOFs) as electrocatalysts for two-electron oxygen reduction reaction (2e- ORR) are highly promising for H2 O2 production, but suffer from the intrinsic activity-selectivity trade-off. Herein, we report a ZnCo bimetal-triazole framework (ZnCo-MTF) as high-efficiency 2e- ORR electrocatalysts. The experimental and theoretical results demonstrate that the coordination between 1,2,3-triazole and Co increases the antibonding-orbital occupancy on the Co-N bond, promoting the activation of Co center. Besides, the adjacent Zn-Co sites on 1,2,3-triazole enable an asymmetric "side-on" adsorption mode of O2 , favoring the reduction of O2 molecules and desorption of OOH* intermediate. By virtue of the unique ligand effect, the ZnCo-MTF exhibits a 2e- ORR selectivity of ≈100 %, onset potential of 0.614 V and H2 O2 production rate of 5.55 mol gcat -1 h-1 , superior to the state-of-the-art zeolite imidazole frameworks. Our work paves the way for the design of 2e- ORR electrocatalysts with desirable coordination and electronic structure.

Application of vacuum assisted venous drainage in heart surgeries for newborns.

OBJECTIVE: To explore the role of cardiopulmonary bypass (CPB) with vacuum assisted venous drainage(VAVD)in the management of newborns with congenital heart diseases. METHODS: Total 15 newborns with congenital heart diseases (11 males and 4 females)underwent heart operations. Their age ranged from 2 days to 28 days [mean:(15.67 ± 2.22)days], and their body weight from 2.3 kg to 4.8 kg [mean: (3.75 ± 0.19)kg]. Sternal median incision was made to establish CPB,during which VAVD was applied for all the newborns. RESULTS: In these 15 newborns,the mean CPB time was from 50 minutes to 343 minutes [mean:(170.3 ± 26.6)minutes], and the mean aortic clamping time ranged from 20 minutes to 172 minutes [mean:(85.8 ± 14.6)minutes]. No macroscopic hematuria, inadequate drainage, or cannulation vena cava difficulty was observed during the procedures. All the newborns were successfully weaned from the machine. No neurological complication due to micro air embolus caused by negative pressure was noted. No vena cava infarction, thrombosis, or other complication was reported after the surgery, although one patient died after the surgery and another patient was discharged upon its family's own decision. CONCLUSIONS: VAVD is a safe, simple, and cost-effective technique. Appropriate negative pressure can the resistance during thinner venous intubation and thus speed up blood drainage,provide adequate perfusion flow,and reduce the pre-filling volume.

Bioengineered materials with selective antimicrobial toxicity in biomedicine.

Fungi and bacteria afflict humans with innumerous pathogen-related infections and ailments. Most of the commonly employed microbicidal agents target commensal and pathogenic microorganisms without discrimination. To distinguish and fight the pathogenic species out of the microflora, novel antimicrobials have been developed that selectively target specific bacteria and fungi. The cell wall features and antimicrobial mechanisms that these microorganisms involved in are highlighted in the present review. This is followed by reviewing the design of antimicrobials that selectively combat a specific community of microbes including Gram-positive and Gram-negative bacterial strains as well as fungi. Finally, recent advances in the antimicrobial immunomodulation strategy that enables treating microorganism infections with high specificity are reviewed. These basic tenets will enable the avid reader to design novel approaches and compounds for antibacterial and antifungal applications.

Periodic mesoporous organosilicas with controlled pore symmetries for peptides enrichment.

Periodic mesoporous organosilicas (PMOs) with controlled structures have been synthesized by using cetyltrimethylammonium bromide (CTAB) and sodium perfluorooctanoate (PFONa) as co-templates, 1,2-bis (triethoxysilyl)ethane (BTEE) as an organosilica precursor. By increasing the weight ratio of PFONa/CTAB, a structure transformation from a cubic (Pm-3n) to a two-dimensional hexagonal (p6m) mesostructure and then to multilamellar vesicles can be observed. The cubic and hexagonal samples have similar particle size (200-750 nm), pore size (2.6 and 2.8 nm, respectively), total pore volume (approximately 0.7 cm3/g), and surface area (approximately 900 m2/g), providing ideal candidates to study the peptide enrichment performance influenced simply by pore symmetries. Matrix-assisted laser desorption ionization time-of-flight mass spectroscopy (MALDI-TOF MS) analysis indicates that PMO with a cubic (Pm-3n) structure is more effective in small molecular weight peptides enrichment compared with PMO with a hexagonal structure, showing the importance of mesostructural control for targeted applications. The phenomena can be attributed to the cage-type structure of the Pm-3n symmetry, which possesses cages with a relatively larger pore size and connectivity with a relatively smaller size. It is suggested that the pore entrances with small size are responsible for entrapping small molecular weight peptides. Our study may shed light on the designed synthesis of functional porous materials with controlled structures and enhanced performance in peptides enrichment.