Self-Zincophilic Dual Protection Host of 3D ZnO/Zn⊂CF to Enhance Zn Anode Cyclability.

Zn dendrite growth and side reactions restrict the practical use of Zn anode. Herein, the design of a novel 3D hierarchical structure is demonstrated with self-zincophilic dual-protection constructed by ZnO and Zn nanoparticles immobilized on carbon fibers (ZnO/Zn⊂CF) as a versatile host on the Zn surface. The unique 3D frameworks with abundant zinc nucleation storage sites can alleviate the structural stress during the plating/stripping process and overpower Zn dendrite growth by moderating Zn2+ flux. Moreover, given the dual protection design, it can reduce the contact area between active zinc and electrolyte, inhibiting hydrogen evolution reactions. Importantly, density functional theory calculations and experimental results confirm that the introduced O atoms in ZnO/Zn⊂CF enhance the interaction between Zn2+ and the host and reduce Zn nucleation overpotential. As expected, the ZnO/Zn⊂CF-Zn electrode exhibits stable Zn plating/stripping with low polarization for 4200 h at 0.2 mA cm-2 and 0.2 mAh cm-2. Furthermore, the symmetrical cell displays a significantly long cycling life of over 1800 h, even at 30 mA cm-2. The fabricated full cells also show impressive cycling performance when coupled with V2O3 cathodes.

National disease burden of respiratory viruses detected in children by polymerase chain reaction.

BACKGROUND: The epidemiology of community-acquired respiratory viruses at the Children's Hospital of Wisconsin between 1996 and 1998 was examined with molecular [multiplex (M) PCR] and standard virologic methods. METHODS AND RESULTS: A total of 3325 patients with lower respiratory infection (LRI) [bronchiolitis (42%), pneumonia (38%) and croup (12%)] were identified. It is estimated that 545,000 LRI hospitalizations occur each year in the United States in children younger than 18 years old (viral, 428,000; pneumonia, 221,000; bronchiolitis, 222,000; croup, 65,000), including a continued increase in bronchiolitis hospitalizations (47.8/1000; <1 year). The most common viruses detected each year in hospitalized children included respiratory syncytial virus (A and B; 117,000), parainfluenza virus (PIV-1 and -2, 48 000; PIV-3, 18,000) and influenza (A and B, 39,000). With multiplex reverse transcription polymerase chain reaction (MPCR), different patient populations demonstrated different LRI epidemiology in relation to specific syndromes and viral causes. At least 21% of LRI hospitalizations were in children with significant medical problems.PIVs were detected much more frequently in immunocompromised children than in previously healthy children (33% vs. 16%). Similarly 15% of respiratory syncytial virus was detected between May and October, mostly in immunocompromised children. Influenza caused 19% of bronchiolitis in previously healthy children, and no virus could be reliably predicted based on clinical presentation, including wheezing. Of children hospitalized for LRI, 40% tested positive for the seven most common respiratory viruses by MPCR. CONCLUSIONS: Work is under way to expand the number of viruses detected by MPCR and to determine whether newly discovered viruses, such as human metapneumovirus, contribute to the burden of pediatric LRI hospitalizations.