Stimulus-Responsive DNA Hydrogel Biosensors for Food Safety Detection.

Food safety has always been a major global challenge to human health and the effective detection of harmful substances in food can reduce the risk to human health. However, the food industry has been plagued by a lack of effective and sensitive safety monitoring methods due to the tension between the cost and effectiveness of monitoring. DNA-based hydrogels combine the advantages of biocompatibility, programmability, the molecular recognition of DNA molecules, and the hydrophilicity of hydrogels, making them a hotspot in the research field of new nanomaterials. The stimulus response property greatly broadens the function and application range of DNA hydrogel. In recent years, DNA hydrogels based on stimulus-responsive mechanisms have been widely applied in the field of biosensing for the detection of a variety of target substances, including various food contaminants. In this review, we describe the recent advances in the preparation of stimuli-responsive DNA hydrogels, highlighting the progress of its application in food safety detection. Finally, we also discuss the challenges and future application of stimulus-responsive DNA hydrogels.

Differences in Clinical and Imaging Features between Asymptomatic and Symptomatic COVID-19 Patients.

Objectives: The clinical and imaging features of asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 and symptomatic COVID-19 patients. Methods: The clinical and chest computed tomography imaging data of 47 asymptomatic carriers and 36 symptomatic COVID-19 patients were derived. All patients underwent 4-6 CT scans over a period of 2-5 days. Results: The bulk of asymptomatic carriers who developed symptoms and most of the COVID-19 patients were older than 18 years of age with a decreased lymphocyte count, abnormal hepatic and renal function, and increased D-dimer and C-reactive protein. In the early stage, the pulmonary lesion involved mostly 1-2 lobes at the peripheral area in asymptomatic carriers but more than three lobes at both the central and peripheral areas in COVID-19 patients. In the progression stage, the lesion of asymptomatic carriers extended from the peripheral to the central area, and no significant difference was found in the lesion range compared with the symptomatic control group. In early improvement stage, the lesion was rapidly absorbed, and lesions were located primarily at the peripheral area in asymptomatic carriers; contrastingly, lesions were primarily located at both the central and peripheral areas in symptomatic patients. Asymptomatic carriers reflected a significantly shorter duration from disease onset to peak progression stage compared with the symptomatic. Conclusions: Asymptomatic carriers are a potential source of transmission and may become symptomatic COVID-19 patients despite indicating less severe pulmonary damage, earlier improvement, and better prognosis. Early isolation and intervention can eliminate such carriers as potential sources of transmission and improve their prognosis.

Effects of progressive muscle relaxation training on negative emotions and sleep quality in COVID-19 patients: A clinical observational study.

This study investigates the effect of progressive muscle relaxation training on negative mood and sleep quality in Coronavirus Pneumonia (COVID-19) patients.COVID-19 is an emerging infectious disease, and there is still uncertainty about when the outbreak will be contained and the effectiveness of treatments. Considering that this disease is highly contagious, patients need to be treated in isolation. This may lead to psychological symptoms such as anxiety and depression, and even sleep problems.This study is a clinical observation study.Participants included 79 COVID-19 patients admitted to a designated hospital for COVID-19 patients in Wuhan from February to March, 2020. Patients were selected and assigned to the control group and the observation group according to their wishes, with 40 and 39 cases in each group, respectively. The control group received routine treatment and nursing, and the observation group received progressive muscle relaxation training, in addition to the routine treatment and nursing. We compared scores of the Pittsburgh Sleep Quality Index Scale (PSQI), the Generalized Anxiety Disorder (GAD-7), and the Patient Health Questionnaire (PHQ-9) before and after the intervention.There was no significant difference in PSQI, GAD-7, and PHQ-9 scores between the control group and the observation group before the intervention (P > .05). After the intervention, the difference in scores of PSQI, GAD-7, and PHQ-9 in the 2 groups were statistically significant (P < .05).Progressive muscle relaxation training can significantly reduce anxiety and depression and improve sleep quality in COVID-19 patients during isolation treatment.Progressive muscle relaxation training was shown to improve the treatment effect of patients and is worthy of clinical promotion.

Prognostic value of serum amyloid A in patients with COVID-19.

OBJECTIVE: To investigate the prognostic value of serum amyloid A (SAA) in the patients with Corona Virus Disease 2019 (COVID-19). METHODS: The medical data of 89 COVID-19 patients admitted to Renmin Hospital of Wuhan University from January 3, 2020 to February 26, 2020 were collected. Eighty-nine cases were divided into survival group (53 cases) and non-survival group (36 cases) according to the results of 28-day follow-up. The SAA levels of all patients were recorded and compared on 1 day after admission (before treatment) and 3 days, 5 days, and 7 days after treatment. The ROC curve was drawn to analyze the prognosis of patients with COVID-19 by SAA. RESULTS: The difference of comparison of SAA between survival group and non-survival group before treatment was not statistically significant, Z1 = - 1.426, P = 0.154. The Z1 values (Z1 is the Z value of the rank sum test) of the two groups of patients at 3 days, 5 days, and 7 days after treatment were - 5.569, - 6.967, and - 7.542, respectively. The P values were all less than 0.001, and the difference was statistically significant. The ROC curve results showed that SAA has higher sensitivity to the prognostic value of 1 day (before treatment), 3 days, 5 days, and 7 days after treatment, with values of 0.806, 0.972, 0.861, and 0.961, respectively. Compared with SAA on the 7th day and C-reactive protein, leukocyte count, neutrophil count, lymphocyte count, and hemoglobin on the 7th day, the sensitivities were: 96.1%, 83.3%, 88.3%, 83.3%, 67.9%, and 83.0%, respectively, of which SAA has the highest sensitivity. CONCLUSION: SAA can be used as a predictor of the prognosis in patients with COVID-19.