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Abstract Introduction Noninvasive ventilation (NIV) is widely used for sequential extubation in patients with chronic obstructive pulmonary disease (COPD). However, NIV may cause many adverse events such as claustrophobia, facial skin compression, air leakage, bloating, and even reflux aspiration, resulting in poor patient compliance/tolerance and high failure rate, especially for older adults who are at high risk of communication difficulties and consciousness disorder. High-flow nasal cannula (HFNC) oxygen therapy is a new alternative support to NIV, but whether it can effectively reduce the rate of re-intubation after extubation in elderly patients with COPD remains controversial. The purpose of this study is to explore the safety and efficacy of HFNC versus NIV for elderly COPD patients after extubation. Methods and analysis This study is an investigator-initiated, single-center, prospective, non-inferior, randomized controlled trial. Elderly patients (age > 65 years) who have received invasive ventilation and was diagnosed with COPD will be randomly assigned to HFNC group or NIV group immediately after extubation with a planned enrollment of 168 patients. The primary outcomes will be reintubation rates at 72 h and 7 days after extubation. Secondary outcomes will include treatment failure, post-extubation vital signs and arterial blood gases, the scores of compliance and comfort of patients, duration of respiratory support after extubation, respiratory support related adverse events, sleep quality scores, usage of sedative and analgesic drugs after extubation, and the incidence of delirium. Additionally, clinical outcomes such as ventilator-free days at 28 days post-randomization, tracheotomy rate, duration of intensive care unit (ICU) and hospital stay, ICU and hospital mortality will be evaluated. Ethics and dissemination This study has been approved by the Ethics Committee of West China Hospital of Sichuan University (2023–2284). Informed consent is required. It is expected that a follow-up randomized controlled trial will be conducted. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences. Trial registration The study was retrospectively registered at ClinicalTrials.gov (ChiCTR2400087312).

WVTaTiCrx (x = 0, 0.25, 0.5, 0.75, 1) refractory high-entropy alloy coatings were prepared on a 42-CrMo steel plate using laser cladding. The purpose of this work is to investigate the effect of the Cr content on the microstructure and properties of the WVTaTiCrx coating. The morphologies and phase compositions of five coatings with different Cr contents were comparatively observed. In addition, the hardness and high-temperature oxidation resistance of the coatings were also analyzed. As a result, with the increase in Cr, the coating grains were more refined. All the coating is mainly composed of the BCC solid-solution phase, which promotes the precipitation of the Laves phase with the increase in Cr. The addition of Cr greatly improves the hardness, high-temperature oxidation resistance and corrosion resistance of the coating. The WVTaTiCr (Cr1) exhibited superior mechanical properties, especially in terms of its exceptional hardness, high-temperature oxidation resistance and outstanding corrosion resistance. The average hardness of the WVTaTiCr alloy coating reaches 627.36 HV. After 50 h of high-temperature oxidation, the oxide weight of WVTaTiCr increases by 5.12 mg/cm2, and the oxidation rate is 0.1 mg/(cm2·h). In 3.5 wt% NaCl solution, the corrosion potential of WVTaTiCr is −0.3198 V, and the corrosion rate is 0.161 mm/a.

Enzymes provide attractive targets for drug development. Quantitative analysis of enzyme reactions can lead to rational drug discovery. For undergraduates majoring in biochemistry or pharmacy and engaged in drug discovery-related work, it is essential to acquire a comprehensive understanding of enzyme kinetics, including experimental methods and the fundamental principles of drug screening. Being overexpressed in cancer, MTHFD2 is an emerging anticancer drug target. Herein, we used MTHFD2 to develop a high-throughput drug screening laboratory course based on enzyme kinetics for upper-division undergraduate students. The learning activities that were designed for students included "Escherichia coli"-based protein expression, protein purification, enzyme activity assay, setting up a high-throughput drug screening assay, and data analysis. The main purpose of this one-week laboratory education course is to provide students with a better understanding of enzyme kinetics, high-throughput drug screening and to help them grasp the relationship between enzyme kinetics and drug discovery. This hands-on course provides students an opportunity to learn how theoretical knowledge is applied in real practice.