Chinese university students showed less disordered eating during the COVID-19 campus lockdown.

OBJECTIVE: The rapid spread of the Omicron variant of COVID-19 in China had resulted in campus lockdown in many universities since February 2022, profoundly affecting students' daily lives. Campus lockdown conditions differ considerably from home quarantine, so that the eating patterns of university students may be different. Thus, the current study aimed to: (1) investigate university students' eating patterns during campus lockdown; (2) identify factors associated with their disordered eating. METHOD: An online survey about recent life changes, disordered eating, stress, depression, and anxiety was carried out from April 8th to May 16th, 2022. A total of 2541 responses from 29 provinces/cities of China were received. RESULTS: 2213 participants were included in the main analysis, and other 86 participants were analyzed separately as a subgroup due to their diagnosis of eating disorder. Participants who were undergoing campus lockdown (the lockdown group) showed less disordered eating than those who had never been in campus lockdown (the never-lockdown group), as well as those who had experienced campus lockdown before (the once-lockdown group). However, they perceived more stress and felt more depressed. Being female, higher BMI, gaining weight, increasing exercise, spending more time on social media, higher level of depression and anxiety were all related to disordered eating in the lockdown group. CONCLUSIONS: Disordered eating among Chinese university students was less prevalent during campus lockdown due to the strict and regular diet. However, there is a potential risk of "revenge eating" after campus lockdown ends. Thus, there should be further tracking and related prevention. LEVEL OF EVIDENCE: IV, uncontrolled trials without any interventions.

A Four-Channel Surface Plasmon Resonance Sensor Functionalized Online for Simultaneous Detections of Anti-SARS-CoV-2 Antibody, Free Viral Particles, and Neutralized Viral Particles.

Current tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detect either the constituent nucleic acids/proteins of the viral particles or antibodies specific to the virus, but cannot provide information about viral neutralization by an antibody and the efficacy of an antibody. Such information is important about individuals' vulnerability to severe symptoms or their likelihood of showing no symptoms. We immobilized online SARS-CoV-2 spike (S1) protein and angiotensin-converting enzyme 2 (ACE2) into separate surface plasmon resonance (SPR) channels of a tris-nitrilotriacetic acid (tris-NTA) chip to simultaneously detect the anti-S1 antibody and viral particles in serum samples. In addition, with a high-molecular-weight-cutoff filter, we separated the neutralized viral particles from the free antibody molecules and used a sensing channel immobilized with Protein G to determine antibody-neutralized viral particles. The optimal density of probe molecules in each fluidic channel can be precisely controlled through the closure and opening of the specific ports. By utilizing the high surface density of ACE2, multiple assays can be carried out without regenerations. These three species can be determined with a short analysis time (<12 min per assay) and excellent sensor-to-sensor/cycle-to-cycle reproducibility (RSD < 5%). When coupled with an autosampler, continuous assays can be performed in an unattended manner at a single chip for up to 6 days. Such a sensor capable of assaying serum samples containing the three species at different levels provides additional insights into the disease status and immunity of persons being tested, which should be helpful for containing the SARS-CoV-2 spread during the era of incessant viral mutations.

Regenerable and high-throughput surface plasmon resonance assay for rapid screening of anti-SARS-CoV-2 antibody in serum samples.

Current serological antibody tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) require enzyme or fluorescent labels, and the titer well plates cannot be reused. By immobilizing histidine (His)-tagged SARS-CoV-2 spike (S1) protein onto tris‒nitrilotriacetic acid (tris-NTA) sensor and using the early association phase for mass-transfer-controlled concentration determination, we developed a rapid and regenerable surface plasmon resonance (SPR) method for quantifying anti-SARS-CoV-2 antibody. On a five-channel SPR instrument and with optimized S1 protein immobilization density, each of the four analytical channels is sequentially used for multiple measurements, and all four channels can be simultaneously regenerated once they have reached a threshold value. Coupled with a programmable autosampler, each sensor can be regenerated at least 20 times, enabling uninterrupted assays of more than 800 serum samples. The accuracy and speed of our method compare well with those of the enzyme-linked immunosorbent assay (ELISA), and the detection limit (0.057 µg mL-1) can easily meet the requirement for screening low antibody levels such as those in convalescent patients. In addition, our method exhibits excellent channel-to-channel (RSD = 1.9%) and sensor-to-sensor (RSD = 2.1%) reproducibility. Obviation of an enzyme label drastically reduced the assay cost, rending our method (<60 cents) much more cost effective than those of commercial ELISA kits ($4.4-11.4). Therefore, our method offers a cost-effective and high-throughput alternative to the existing methods for serological measurements of anti-SARS-CoV-2 antibody levels, holding great promise for rapid screening of clinical samples without elaborate sample pretreatments and special reagents.