Water Impalement Resistance and Drag Reduction of the Superhydrophobic Surface with Hydrophilic Strips.

Superhydrophobic surfaces (SHS) offer versatile applications by trapping an air layer within microstructures, while water jet impact can destabilize this air layer and deactivate the functions of the SHS. The current work presents for the first time that introducing parallel hydrophilic strips to SHS (SHS-s) can simultaneously improve both water impalement resistance and drag reduction (DR). Compared with SHS, SHS-s demonstrates a 125% increase in the enduring time against the impact of water jet with velocity of 11.9 m/s and a 97% improvement in DR at a Reynolds number of 1.4 × 104. The key mechanism lies in the enhanced stability of the air layer due to air confinement by the adjacent three-phase contact lines. These lines not only impede air drainage through the surface microstructures during water jet impact, entrapping the air layer to resist water impalement, but also prevent air floating up due to buoyancy in Taylor-Couette flow, ensuring an even spread of the air layer all over the rotor, boosting DR. Moreover, failure modes of SHS under water jet impact are revealed to be related to air layer decay and surface structure destruction. This mass-producible structured surface holds the potential for widespread use in DR for hulls, autonomous underwater vehicles, and submarines.

Head and neck surgical oncology in the time of a pandemic: Subsite-specific triage guidelines during the COVID-19 pandemic.

BACKGROUND: COVID-19 pandemic has strained human and material resources around the world. Practices in surgical oncology had to change in response to these resource limitations, triaging based on acuity, expected oncologic outcomes, availability of supportive resources, and safety of health care personnel. METHODS: The MD Anderson Head and Neck Surgery Treatment Guidelines Consortium devised the following to provide guidance on triaging head and neck cancer (HNC) surgeries based on multidisciplinary consensus. HNC subsites considered included aerodigestive tract mucosa, sinonasal, salivary, endocrine, cutaneous, and ocular. RECOMMENDATIONS: Each subsite is presented separately with disease-specific recommendations. Options for alternative treatment modalities are provided if surgical treatment needs to be deferred. CONCLUSION: These guidelines are intended to help clinicians caring for patients with HNC appropriately allocate resources during a health care crisis, such as the COVID-19 pandemic. We continue to advocate for individual consideration of cases in a multidisciplinary fashion based on individual patient circumstances and resource availability.