Novel B and N Sites of One-Dimensional Boron Nitride Fiber: Efficient Performance and Mechanism in the Formaldehyde Capture Process.

Identification of adsorption centers with atomic levels of adsorbents is crucial to study the adsorption of formaldehyde (HCHO), especially for an in-depth understanding of the mechanism of HCHO capture. Herein, we investigate the HCHO adsorption performance of one-dimensional (1D) nanoporous boron nitride (BN) fiber, and explore the adsorption mechanism by density functional theory (DFT) calculations, including adsorption energy change and Bader charge change, and experimental study as well. Research shows that the 1D nanoporous BN fiber possesses a high concentration of Lewis pairs, which act as Lewis acid and Lewis base sites associated with the fiber's electron-deficient and electron-rich features. It is worth noting that the HCHO removal efficiency of a typical sample is as high as 91%. This work may open the door to the field of adsorption of other pollutants by constructing Lewis pairs in the future.

Comparison of Ventilator-Associated Pneumonia and Surgical Site Infection between Two Methods of Tracheostomy.

Objective: To compare the incidence of ventilator-associated pneumonia (VAP) and surgical site infection (SSI) between percutaneous dilatational tracheostomy (PDT) and surgical tracheostomy (ST). Methods: Data on 487 patients undergoing tracheostomy between 1st January 2014 and 30th September 2020 were reviewed. Patients were divided according to the surgical techniques. Clinical characteristics and postoperative care were compared to explore the risk factors for SSI and VAP. All tracheostomies were performed by intensivists who had completed at least ten tracheostomies. ST was performed using standard techniques. PDT was performed according to a modification technique described by Ciaglia. All procedures were performed at the bedside in the ICU. Results: Of all, 344 patients (70.6%) were men and 143 (29.4%) were women, and the mean age was 56 years (standard derivation [SD] 12 years). Two hundred and sixty-six patients (54.6%) received PDT, and 221 (45.4%) received SY. Patients in the PDT group had a significantly lower rate of SSI (3.4% vs. 8.5%, P = 0.01) compared with the ST group. Multivariate analysis revealed that comorbidities (P = 0.003), surgical type (P = 0.01), and cluster nursing (P < 0.001) were independent risk factors for SSI; age (P = 0.005), comorbidities (P < 0.001), smoking (P = 0.008), and cluster nursing (P = 0.01) were independent risk factors for VAP. Conclusion: PDT significantly reduces the risk of SSI. Proper care should be administrated in patients with one or more risk factors of SSI or VAP to prevent the occurrence of complications.