A High-Sensitivity Gravimetric Biosensor Based on S1 Mode Lamb Wave Resonator.

The development of MEMS acoustic resonators meets the increasing demand for in situ detection with a higher performance and smaller size. In this paper, a lithium niobate film-based S1 mode Lamb wave resonator (HF-LWR) for high-sensitivity gravimetric biosensing is proposed. The fabricated resonators, based on a 400-nm X-cut lithium niobate film, showed a resonance frequency over 8 GHz. Moreover, a PMMA layer was used as the mass-sensing layer, to study the performance of the biosensors based on HF-LWRs. Through optimizing the thickness of the lithium niobate film and the electrode configuration, the mass sensitivity of the biosensor could reach up to 74,000 Hz/(ng/cm2), and the maximum value of figure of merit (FOM) was 5.52 × 107, which shows great potential for pushing the performance boundaries of gravimetric-sensitive acoustic biosensors.

Mental status of patients with chronic insomnia in China during COVID-19 epidemic.

AIM: To study the sleep and mental health of chronic insomnia patients in China during coronavirus disease in 2019 (COVID-19) epidemic. METHODS: A total of 764 patients with chronic insomnia were included in this study. From 17 January 2020 to 24 January 2020, insomnia, anxiety and physical symptoms were evaluated online, and they were followed up for 4 and 8 weeks. Main outcomes and indicators were assessed using the Pittsburgh Sleep Quality Index (PSQI) and each factor score, the General Anxiety Disorder-7 (GAD-7) and the Patient Health Questionnaire-15 (PHQ-15), respectively. In addition, insomnia, anxiety and physical symptoms were assessed at baseline and at the end of fourth and eighth weeks. Wilcoxon signed rank test was used to compare the changes in patients' scale scores at different time points. RESULTS: Among the 764 participants, there were 755 and 738 evaluators who completed the fourth and eighth weeks, respectively, and the questionnaire completion rates were 98.82% and 96.60%, respectively. Among them, there are 459 (60.0%) aged 41-60 years old, 546 (71.5%) women, 218 (28.5%) men and 313 (41%) college degrees. After 8 weeks of follow-up, the differences in sleep status, anxiety symptoms and physical symptoms were statistically significant. Among the factors of PSQI, there were differences in subjective sleep quality, sleep latency, sleep duration, sleep disturbance (disorder), sleep efficiency and daytime function. At 4 weeks of follow-up, there was a statistically significant difference in the use of hypnotic drugs; at 8 weeks of follow-up, there was no statistically significant difference in the use of hypnotic drugs. CONCLUSION: Under the influence of the COVID-19, the sleep status and anxiety of patients with chronic insomnia are affected by the epidemic.

Development of a rapid and sensitive quantum dot nanobead-based double-antigen sandwich lateral flow immunoassay and its clinical performance for the detection of SARS-CoV-2 total antibodies.

Owing to the over-increasing demands in resisting and managing the coronavirus disease 2019 (COVID-19) pandemic, development of rapid, highly sensitive, accurate, and versatile tools for monitoring total antibody concentrations at the population level has been evolved as an urgent challenge on measuring the fatality rate, tracking the changes in incidence and prevalence, comprehending medical sequelae after recovery, as well as characterizing seroprevalence and vaccine coverage. To this end, herein we prepared highly luminescent quantum dot nanobeads (QBs) by embedding numerous quantum dots into polymer matrix, and then applied it as a signal-amplification label in lateral flow immunoassay (LFIA). After covalently linkage with the expressed recombinant SARS-CoV-2 spike protein (RSSP), the synthesized QBs were used to determine the total antibody levels in sera by virtue of a double-antigen sandwich immunoassay. Under the developed condition, the QB-LFIA can allow the rapid detection of SARS-CoV-2 total antibodies within 15 min with about one order of magnitude improvement in analytical sensitivity compared to conventional gold nanoparticle-based LFIA. In addition, the developed QB-LFIA performed well in clinical study in dynamic monitoring of serum antibody levels in the whole course of SARS-CoV-2 infection. In conclusion, we successfully developed a promising fluorescent immunological sensing tool for characterizing the host immune response to SARS-CoV-2 infection and confirming the acquired immunity to COVID-19 by evaluating the SRAS-CoV-2 total antibody level in the crowd.

[Diagnosis and treatment of community-acquired pneumonia in elderly patients combined with coronavirus disease 2019: analysis of 1 case].

OBJECTIVE: To explore the pathological characteristics and outcomes of elderly patients with community acquired pneumonia (CAP) accompanied by coronavirus disease 2019 (COVID-19). METHODS: The diagnosis and treatment process of one elderly patient with CAP accompanied by COVID-19 who was admitted to COVID-19 Treatment Center of Liaoning Province on February 7, 2020 were reviewed. The experience of treatment by analyzing the characteristics of such type of patients during diagnosis and treatment were summarized. RESULTS: A female patient, aged 79 years ald, was admitted to the Center with following features: fever, dry cough, fatigue with dyspnea, scattered moist rales in both lungs, oxygenation index (PaCO2/FiO2) of 95 mmHg (1 mmHg = 0.133 kPa), and diffuse interstitial pneumonia in both lungs indicated by chest CT, of which the majority were ground glass-like and fibrous lesions. It was confirmed to be consistent with the feature of severe COVID-19 cases. The patient was successfully cured one month later following anti-inflammatory, anti-viral and high-flow oxygen therapies, homeostasis maintenance of the body, psychological counseling, etc. Accordingly, the treatment experience in CAP combined with COVID-19 in the elderly patients was summarized as follows. In respiratory system, the timing of high-flow oxygen therapy and mechanical ventilation should be seized. As for anti-inflammatory and antiviral therapy, attention should be paid to the treatment of CAP as well as antiviral therapy and symptomatic and supportive therapy. With the progression of the disease, the production of drug-resistant bacteria and the possibility of fungal infection should be paid attention to. For the circulatory system, we should pay attention to the stability of fluid volume and internal environment, and strengthen hemodynamic monitoring and bedside ultrasound to evaluate the cardiovascular capacity-load. In the aspect of the immune system, the selection of the application time of immune-enhancers and glucocorticoids should be paid attention to. In terms of enteral nutrition, early low-fat and high-protein diet is conducive to the recovery of intestinal function and the prevention of bacterial translocation. In addition to the protection of the function of important organs, therapies such as reasonable sedation and psychological intervention should also be used. CONCLUSIONS: Elderly patients with CAP accompanied by COVID-19 have complicated conditions and high degree of difficulty in treatment. Comprehensive evaluation of the disease as well as synthetic and effective intervention are the key factors of successful treatment of such patients.