Noncontact liquid–solid nanogenerators as self-powered droplet sensors

Liquid–solid triboelectric nanogenerators (L–S TENGs) can generate corresponding electrical signal responses through the contact separation of droplets and dielectrics and have a wide range of applications in energy harvesting and self-powered sensing. However, the contact between the droplet and the electret will cause the contact L–S TENG's performance degradation or even failure. Here we report a noncontact triboelectric nanogenerator (NCLS-TENG) that can effectively sense droplet stimuli without contact with droplets and convert them into electrical energy or corresponding electrical signals. Since there is no contact between the droplet and the dielectric, it can continuously and stably generate a signal output. To verify the feasibility of NCLS-TENG, we demonstrate the modified murphy's dropper as a smart infusion monitoring system. The smart infusion monitoring system can effectively identify information such as the type, concentration, and frequency of droplets. NCLS-TENG show great potential in smart medical, smart wearable and other fields.

Differences in clinical characteristics between younger and older patients with COVID-19 and their relationship with the length of hospital stay.

Background: The coronavirus disease 2019 (COVID-19) pandemic is currently threatening the health of individuals worldwide. We compared the clinical characteristics between younger patients (aged <60 years) and older patients (aged ≥60 years) with COVID-19, detected the risk factors associated with a prolonged hospital stay, and examined the treatments commonly used with a particular focus on antiviral therapies. Methods: This retrospective study was conducted at the West Campus, Union Hospital affiliated to Tongji Medical College of Huazhong University of Science and Technology (Wuhan, China). The sample consisted of 123 patients admitted to the hospital between 9th February, 2020, and 3rd March, 2020. The data related to the demographics, laboratory findings, and treatment were analyzed to identify discrepancies between younger and older patients and those with and without primary diseases. The risk factors that contribute to a prolonged hospital stay were subsequently identified. Results: Patients aged ≥60 years required longer hospital stay than younger patients (P=0.001). The percentage of lymphocytes was significantly lower in older patients and those with primary diseases (P=0.016 and P=0.042, respectively). The findings revealed that the risk factors that contributed to the length of hospital stay were age, the number of days of illness before hospitalization, white blood cell (WBC) count and albumin levels at admission, a neutrophil fraction at discharge, and antibiotic treatment. Analysis using a model that consisted of the above five risk factors for predicting prolonged hospital stay (>14 days) yielded an area under the ROC (AuROC) curve of 0.716. Antiviral and antibiotic treatments were administered to 97.6% and 39.0% of patients, respectively. The antiviral drugs most commonly administered were traditional Chinese medicine (83.7%) and arbidol (75.6%). Conclusions: In this study, older patients and those with primary diseases were at a higher risk of worse clinical manifestations. The physicians who treat the patients should pay close attention to the risk factors that contribute to the length of hospital stay, which could be used for predicting prolonged hospital stay. Traditional Chinese medicine and arbidol were the most frequently used antiviral drugs. Nevertheless, the extent to which these medications can effectively treat COVID-19 warrants further investigation.

Human IRF1 governs macrophagic IFN-γ immunity to mycobacteria.

Inborn errors of human IFN-γ-dependent macrophagic immunity underlie mycobacterial diseases, whereas inborn errors of IFN-α/ß-dependent intrinsic immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria and related intramacrophagic pathogens. These children have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2, which is life-threatening in individuals with impaired IFN-α/ß immunity. In leukocytes or fibroblasts stimulated in vitro, IRF1-dependent responses to IFN-γ are, both quantitatively and qualitatively, much stronger than those to IFN-α/ß. Moreover, IRF1-deficient mononuclear phagocytes do not control mycobacteria and related pathogens normally when stimulated with IFN-γ. By contrast, IFN-α/ß-dependent intrinsic immunity to nine viruses, including SARS-CoV-2, is almost normal in IRF1-deficient fibroblasts. Human IRF1 is essential for IFN-γ-dependent macrophagic immunity to mycobacteria, but largely redundant for IFN-α/ß-dependent antiviral immunity.

Inborn errors of OAS-RNase L in SARS-CoV-2-related multisystem inflammatory syndrome in children.

Multisystem inflammatory syndrome in children (MIS-C) is a rare and severe condition that follows benign COVID-19. We report autosomal recessive deficiencies of OAS1, OAS2, or RNASEL in five unrelated children with MIS-C. The cytosolic double-stranded RNA (dsRNA)-sensing OAS1 and OAS2 generate 2'-5'-linked oligoadenylates (2-5A) that activate the single-stranded RNA-degrading ribonuclease L (RNase L). Monocytic cell lines and primary myeloid cells with OAS1, OAS2, or RNase L deficiencies produce excessive amounts of inflammatory cytokines upon dsRNA or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) stimulation. Exogenous 2-5A suppresses cytokine production in OAS1-deficient but not RNase L-deficient cells. Cytokine production in RNase L-deficient cells is impaired by MDA5 or RIG-I deficiency and abolished by mitochondrial antiviral-signaling protein (MAVS) deficiency. Recessive OAS-RNase L deficiencies in these patients unleash the production of SARS-CoV-2-triggered, MAVS-mediated inflammatory cytokines by mononuclear phagocytes, thereby underlying MIS-C.

Recessive inborn errors of type I IFN immunity in children with COVID-19 pneumonia.

Recessive or dominant inborn errors of type I interferon (IFN) immunity can underlie critical COVID-19 pneumonia in unvaccinated adults. The risk of COVID-19 pneumonia in unvaccinated children, which is much lower than in unvaccinated adults, remains unexplained. In an international cohort of 112 children (<16 yr old) hospitalized for COVID-19 pneumonia, we report 12 children (10.7%) aged 1.5-13 yr with critical (7 children), severe (3), and moderate (2) pneumonia and 4 of the 15 known clinically recessive and biochemically complete inborn errors of type I IFN immunity: X-linked recessive TLR7 deficiency (7 children) and autosomal recessive IFNAR1 (1), STAT2 (1), or TYK2 (3) deficiencies. Fibroblasts deficient for IFNAR1, STAT2, or TYK2 are highly vulnerable to SARS-CoV-2. These 15 deficiencies were not found in 1,224 children and adults with benign SARS-CoV-2 infection without pneumonia (P = 1.2 × 10-11) and with overlapping age, sex, consanguinity, and ethnicity characteristics. Recessive complete deficiencies of type I IFN immunity may underlie ∼10% of hospitalizations for COVID-19 pneumonia in children.

Respiratory viral infections in otherwise healthy humans with inherited IRF7 deficiency.

Autosomal recessive IRF7 deficiency was previously reported in three patients with single critical influenza or COVID-19 pneumonia episodes. The patients' fibroblasts and plasmacytoid dendritic cells produced no detectable type I and III IFNs, except IFN-ß. Having discovered four new patients, we describe the genetic, immunological, and clinical features of seven IRF7-deficient patients from six families and five ancestries. Five were homozygous and two were compound heterozygous for IRF7 variants. Patients typically had one episode of pulmonary viral disease. Age at onset was surprisingly broad, from 6 mo to 50 yr (mean age 29 yr). The respiratory viruses implicated included SARS-CoV-2, influenza virus, respiratory syncytial virus, and adenovirus. Serological analyses indicated previous infections with many common viruses. Cellular analyses revealed strong antiviral immunity and expanded populations of influenza- and SARS-CoV-2-specific memory CD4+ and CD8+ T cells. IRF7-deficient individuals are prone to viral infections of the respiratory tract but are otherwise healthy, potentially due to residual IFN-ß and compensatory adaptive immunity.

Antibody response in COVID-19 patients with and without re-positive RT-PCR results during the convalescent phase.

Nucleic acid testing and antibody testing data from 143 recovered COVID-19 patients during the convalescent phase were retrospectively analyzed. A total of 23 (16.1%) recovered patients re-tested positive for SARS-CoV-2 RNA by RT-PCR. Three months after symptom onset, 100% and 99.3% of the patients remained positive for total and IgG antibodies, and the antibody levels remained high. IgM antibodies declined rapidly, with a median time to seroconversion of 67 (95% CI: 59, 75) days after onset. Approximately 25% of patients were seronegative for IgA antibodies at three months after onset. There was no statistically significant difference in antibody kinetics between patients with and without re-positive RT-PCR results during the convalescent phase.

Nutritional practice in critically ill COVID-19 patients: A multicenter ambidirectional cohort study in Wuhan and Jingzhou.

BACKGROUND AND OBJECTIVES: The novel coronavirus disease (COVID-19) epidemic is spreading all over the world. With the number of cases increasing rapidly, the epidemiological data on the nutritional practice is scarce. In this study, we aim to describe the clinical characteristics and nutritional practice in a cohort of critically ill COVID-19 patients. METHODS AND STUDY DESIGN: This is a multicenter, ambidirectional cohort study conducted at 11 hospitals in Hubei Province, China. All eligible critical COVID-19 patients in the study hospital intensive care units at 00:00, March 6th, 2020, were included. Data collection was performed via written case report forms. RESULTS: A total of 44 patients were identified and enrolled, of whom eight died during the 28-day outcome follow- up period. The median interval between hospital admission and the study day was 24 (interquartile range, 13- 26) days and 52.2% (23 of 44) of patients were on invasive mechanical ventilation. The median nutrition risk in critically ill (mNUTRIC) score was 3 (interquartile range, 2-5) on the study day. During the enrolment day, 68.2% (30 of 44) of patients received enteral nutrition (EN), while 6.8% (3 of 44) received parenteral nutrition (PN) alone. Nausea and aspiration were uncommon, with a prevalence of 11.4% (5 of 44) and 6.8% (3 of 44), respectively. As for energy delivery, 69.7% (23 of 33) of patients receiving EN and/or PN were achieving their prescribed targets. CONCLUSIONS: The study showed that EN was frequently applied in critical COVID-19 patients. Energy delivery may be suboptimal in this study requiring more attention.

Depressive and Anxiety Symptoms of Healthcare Workers in Intensive Care Unit Under the COVID-19 Epidemic: An Online Cross-Sectional Study in China.

Background: Since the coronavirus disease-2019 (COVID-19) outbreak, intensive care unit (ICU) healthcare workers were responsible for the critical infected patients. However, few studies focused on the mental health of ICU healthcare workers. This study aimed to investigate the psychological impact of COVID-19 on ICU healthcare workers in China. Methods: We distributed the nine-item Patient Health Questionnaire (PHQ-9) and seven-item General Anxiety Disorder questionnaire (GAD-7) online to ICU healthcare workers in China. Respondents were divided into frontline and second-line according to whether they have contact with COVID-19 patients. Depressive and anxiety symptoms of all respondents were evaluated based on their questionnaire scores. Results: There were 731 ICU healthcare workers finally enrolled in our study, including 303 (41.5%) male, 383 (52.4%) doctors, and 617 (84.4%) aged 26-45 years. All in all, 482 (65.9%) ICU healthcare workers reported symptoms of depression, while 429 (58.7%) reported anxiety. There was no significant difference between frontline (n = 325) and second-line (n = 406) respondents in depression (P = 0.15) and anxiety severity (P = 0.56). Logistic regression analysis showed that being female, ICU work time >5 years, and night duty number ≥10 were risk factors of developing depressive and anxiety symptoms. Income reduction was separately identified as risk of anxiety. Additionally, ICU work time >5 years was also identified as risk of developing moderate-severe depressive and anxiety symptoms. Conclusions: Frontline ICU work was not associated with higher risk of depressive and anxiety symptoms during COVID-19 pandemic remission period in China. Actions like controlling night duty number, ensuring vacation, and increasing income should be taken to relieve mental health problem. Furthermore, we should pay close attention to those who had worked long years in ICU.

Effects of a Serum Heating Procedure for Inactivating COVID-19 on Common Biochemical Tests.

BACKGROUND: COVID-19 has recently been declared an epidemic by the WHO, and there is an urgent need for affected countries and laboratories to assess and treat people at risk of COVID-19. A heat procedure has been suggested for specimen inactivation. This study was designed to evaluate the effect of serum heating on biochemical indexes, and providing a basis for accurate detection results of the COVID-19 patients. METHODS: We collected 29 normal cases of two tubes of 5 mL whole blood. One tube was analyzed directly, and the other was analyzed after heating at 56°C 30 minutes. RESULTS: A total of 34 serum biochemical index quantitative results were obtained, 28/34 indexes were not significantly affected by the heat inactivation and remained clinically interpretable. As the thermal inactivation for these indexes showed good correlation, ALB (p = 0.04, Pearson R = 0.91, 2.6% mean increase), CysC (p = 0.03, Pearson R = 0.98, 9.9% mean increase), CO2CP (p < 0.001, Pearson R = 0.96, 13% mean decrease), they were still inter-pretable. Four biochemical indexes ALP, CK, CK-MB, and insulin were inactivated and showed significant statistical differences (p < 0.001). CONCLUSIONS: Our study showed CK, CK-MB, ALP, and insulin were sensitive to heat and will be inhibited or degrade after heating, indicating that the rapid decrease of this indexes in the COVID-19 patients may be caused by sample heat inactivation. For safety and diagnostic accuracy, we recommend the use of a point-of-care device for blood gases, electrolytes, troponin, and liver and renal function tests within a ISL 2 or above biosafety cabinet with level 3 or above biosafety laboratory practice.

Improving the subway attraction for the post-COVID-19 era: The role of fare-free public transport policy.

Coronavirus disease 2019 (COVID-19) has had a disruptive impact on transportation. To prevent a return to more widespread personal automobile use due to social distancing requirements, public transport should regain its critical role in carrying a large number of passengers. To this end, three Chinese cities, Hangzhou, Ningbo, and Xiamen, implemented fare-free policies to lure passengers back to public transport. To capture the effect of these policies implementation on the daily subway passenger flow, a synthetic control method is used to construct a counterfactual outcome of interest for these three cities. The results show that the peak-hours free-ride policy in Hangzhou had no significant effect on subway ridership, the "more rides, more discounts" and off-peak-hours free-ride policies in Ningbo increased subway ridership by about 24% in the first month, and a rest day free-ride policy in Xiamen increased subway ridership by 2.3 times over five rest days. Nevertheless, the role of the fare-free policies in helping subway ridership rebound to the historical levels is limited, whether it is during or after policy implementation. Findings of the current study can inform the local authorities and transport operators that the multi-pronged approaches should be implemented in tandem with the fare-free policies for increasing subway attraction during the recovery phase of the COVID-19 pandemic.

Distinct antibody repertoires against endemic human coronaviruses in children and adults.

Four endemic human coronaviruses (HCoVs) are commonly associated with acute respiratory infection in humans. B cell responses to these "common cold" viruses remain incompletely understood. Here we report a comprehensive analysis of CoV-specific antibody repertoires in 231 children and 1168 adults using phage immunoprecipitation sequencing. Seroprevalence of antibodies against endemic HCoVs ranged between approximately 4% and 27% depending on the species and cohort. We identified at least 136 novel linear B cell epitopes. Antibody repertoires against endemic HCoVs were qualitatively different between children and adults in that anti-HCoV IgG specificities more frequently found among children targeted functionally important and structurally conserved regions of the spike, nucleocapsid, and matrix proteins. Moreover, antibody specificities targeting the highly conserved fusion peptide region and S2' cleavage site of the spike protein were broadly cross-reactive with peptides of epidemic human and nonhuman coronaviruses. In contrast, an acidic tandem repeat in the N-terminal region of the Nsp3 subdomain of the HCoV-HKU1 polyprotein was the predominant target of antibody responses in adult donors. Our findings shed light on the dominant species-specific and pan-CoV target sites of human antibody responses to coronavirus infection, thereby providing important insights for the development of prophylactic or therapeutic monoclonal antibodies and vaccine design.

Inborn errors of type I IFN immunity in patients with life-threatening COVID-19.

Clinical outcome upon infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ranges from silent infection to lethal coronavirus disease 2019 (COVID-19). We have found an enrichment in rare variants predicted to be loss-of-function (LOF) at the 13 human loci known to govern Toll-like receptor 3 (TLR3)- and interferon regulatory factor 7 (IRF7)-dependent type I interferon (IFN) immunity to influenza virus in 659 patients with life-threatening COVID-19 pneumonia relative to 534 subjects with asymptomatic or benign infection. By testing these and other rare variants at these 13 loci, we experimentally defined LOF variants underlying autosomal-recessive or autosomal-dominant deficiencies in 23 patients (3.5%) 17 to 77 years of age. We show that human fibroblasts with mutations affecting this circuit are vulnerable to SARS-CoV-2. Inborn errors of TLR3- and IRF7-dependent type I IFN immunity can underlie life-threatening COVID-19 pneumonia in patients with no prior severe infection.

Recurrence of positive SARS-CoV-2 viral RNA in recovered COVID-19 patients during medical isolation observation.

Recently, the recurrence of positive SARS-CoV-2 viral RNA in recovered COVID-19 patients is receiving more attention. Herein we report a cohort study on the follow-up of 182 recovered patients under medical isolation observation. Twenty (10.99%) patients out of the 182 were detected to be SARS-CoV-2 RNA positive (re-positives), although none showed any clinical symptomatic recurrence, indicating that COVID-19 responds well to treatment. Patients aged under 18 years had higher re-positive rates than average, and none of the severely ill patients re-tested positive. There were no significant differences in sex between re-positives and non-re-positives. Notably, most of the re-positives turned negative in the following tests, and all of them carried antibodies against SARS-CoV-2. This indicates that they might not be infectious, although it is still important to perform regular SARS-CoV-2 RNA testing and follow-up for assessment of infectivity. The findings of this study provide information for improving the management of recovered patients, and for differentiating the follow-up of recovered patients with different risk levels.

Correlation between immune response and self-reported depression during convalescence from COVID-19.

Self-reported depression has been observed in coronavirus disease-2019 (COVID-19) patients, infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), during discharge from the hospital. However, the cause of this self-reported depression during the convalescent period remains unclear. Here, we report the mental health status of 96 convalescent COVID-19 patients who were surveyed using an online questionnaire at the Shenzhen Samii Medical Center from March 2 to March 12, 2020 in Shenzhen, China. After obtaining their informed consent, we retrospectively analyzed the clinical characteristics of patients, including routine blood and biochemical data. The results suggested that patients with self-reported depression exhibited increased immune response, as indicated by increased white blood cell and neutrophil counts, as well as neutrophil-to-lymphocyte ratio. However, the mechanism linking self-reported depression to these cellular changes needs further study. In conclusion, self-reported depression occurred at an early stage in convalescent COVID-19 patients, and changes in immune function were apparent during short-term follow-up of these patients after discharge. Appropriate psychological interventions are necessary, and changes in immune function should be emphasized during long-term follow up of these patients.