Background: Epidemiologic evidence suggests that physical activity benefits cognition, but results from randomized trials in sedentary individuals are limited and inconsistent. Objective: To evaluate the effects of physical activity on cognition among sedentary older adults. Objective: A systematic literature search for eligible studies published up to January 1, 2021, was performed on six international (PubMed, Cochrane Library, Web of Science, Sinomed, FMRS, and OVID) and three Chinese databases (Wanfang, China National Knowledge Infrastructure, and VIP). We estimated the effect of physical activity on the cognition of sedentary elderly by standardized mean differences (SMD) and 95% confidence intervals (CI) using a random-effects model. We evaluated publication bias using funnel plots and heterogeneity using I2 statistics. Subgroup analyses were conducted by baseline cognition, intervention duration, activity type, and country. Results: Seven randomized controlled trials (RCTs) comprising 321 (experimental group, 164; control group, 157) sedentary older adults were included in the meta-analysis. Physical activity significantly improved cognition in sedentary elderly adults compared with controls (SMD: 0.50, 95% CI:0.09–0.92). Subgroup analyses showed significant effects of baseline cognition impairment (SMD: 9.80, 95% CI: 5.81–13.80), intervention duration >  12 weeks (SMD: 2.85, 95% CI: 0.73–4.96), aerobic exercise (SMD: 0.74, CI: 0.19–1.29), and countries other than the United States (SMD: 10.50, 95% CI: 7.08–13.92). Conclusion: Physical activity might have a general positive effect on the cognition of sedentary older adults. Intervention >  12 weeks and aerobic exercise can effectively delay their cognitive decline; however, more rigorous RCTs are needed to support our findings.

Aim To investigate the influencing factors in professional identity of undergraduate nursing students after the outbreak of COVID‐19. Design Cross‐sectional study. Methods The study covered 2,999 nursing students in six undergraduate nursing schools. Several self‐report questionnaires were used to collect the general information, psychological stress, coping styles and professional identity of the undergraduate nursing students. Results The overall average score of the professional identity of nursing students (3.67 ± 0.51) has increased significantly after the outbreak of COVID‐19. The professional identity of the undergraduate nursing students was negatively correlated with psychological stress ( r = −0.23, p < .001), expectation ( r = −0.12, p < .001) and avoidance ( r = −0.16, p < .001), but was positively correlated with solving problems ( r = 0.18, p < .001) and seeking support ( r = 0.12, p < .001). Academic performance, positions, grades, reasons for choosing a nursing profession, parents or relatives engaged in nursing work and the risk degree of residence were the factors influencing the professional identity score of undergraduate nursing students' ( p < .001).

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing COVID-19 pandemic, which has resulted in more than two million deaths at 2021 February . There is currently no approved therapeutics for treating COVID-19. The SARS-CoV-2 Spike protein is considered a key therapeutic target by many researchers. Here we describe the identification of several monoclonal antibodies that target SARS-CoV-2 Spike protein. One human antibody, CA521FALA, demonstrated neutralization potential by immunizing human antibody transgenic mice. CA521FALA showed potent SARS-CoV-2-specific neutralization activity against SARS-CoV-2 pseudovirus and authentic SARS-CoV-2 infection in vitro. CA521FALA also demonstrated having a long half-life of 9.5 days in mice and 9.3 days in rhesus monkeys. CA521FALA inhibited SARS-CoV-2 infection in SARS-CoV-2 susceptible mice at a therapeutic setting with virus titer of the lung reduced by 4.5 logs. Structural analysis by cryo-EM revealed that CA521FALA recognizes an epitope overlapping with angiotensin converting enzyme 2 (ACE2)-binding sites in SARS-CoV-2 RBD in the Spike protein. CA521FALA blocks the interaction by binding all three RBDs of one SARS-CoV-2 spike trimer simultaneously. These results demonstrate the importance for antibody-based therapeutic interventions against COVID-19 and identifies CA521FALA a promising antibody that reacts with SARS-CoV-2 Spike protein to strongly neutralize its activity.

A thermal manipulator for use in high temperature environments was designed and constructed based on the coordinate transformation method of transformation thermodynamics. The thermal manipulator has two key functions: (1) Guides the heat flux from one region (the center heat source) and (2) Concentrates the guided heat flux to multiple distributed regions outside. The thermal manipulator uses multiple fan-shaped thermal concentrators around the heat source. The fan-shaped concentrators with highly anisotropic thermal conductivities were made of two isotropic materials, copper and a synthesized silica-alumina fibrous matrix, with a working temperature upper limit of 1000°C. Simulations and experiments show that the copper-based metamaterial thermal manipulators can efficiently guide the heat flux from the central heat source and concentrate the heat flux at multiple distributed regions in a high-temperature environment. The thermal manipulator heat flux concentration efficiency was 55.4% with a region concentration ratio of 2.50 which indicates a very strong heat concentration capability which is more than twice that of traditional isotropic materials. Thus, this research provides an effective thermal manipulating method for high-temperature conditions.

According to the heat conduction theory and effective medium theory, we fabricated a six-layer cylinder heat diffusion cloak by mixing heat conduction materials. We measured the time-dependant heat wave at the iso-temperature lines and the heat flux lines with a self-made heat wave device. The experiment results show that the iso-temperature lines are parallel outside the outer circle, the heat fluxes are parallel and equal outside the outer circle, and the heat fluxes in the inner circle are much smaller than those outside the outer circle, namely, the heat fluxes are guided outside the cloaking region.