Ordered Assembly of DNA on Topological Insulator Bi2Se3 and Octadecylamine for a Sensitive Biosensor.

Controlling the assembly of DNA in order on a suitable electrode surface is of great significance for biosensors and disease diagnosis, but it is full of challenges. In this work, we creatively assembled DNA on the surface of octadecylamine (ODA)-modified topological insulator (Tls) Bi2Se3 and developed an electrochemical biosensor to detect biomarker DNA of coronavirus disease 2019 (COVID-19). A high-quality Bi2Se3 sheet was obtained from a single crystal synthesized in our lab. A uniform ODA layer was coated in argon by chemical vapor deposition (CVD). We observed and analyzed the assembly and mechanism of single-strand DNA (ssDNA) and double-strand DNA (dsDNA) on the Bi2Se3 surface through atomic force microscopy (AFM) and molecular dynamics (MD) simulations. The electrochemical signal revealed that the biosensor based on the DNA/ODA/Bi2Se3 electrode has a wide linear detection range from 1.0 × 10-12 to 1.0 × 10-8 M, with the limit of detection as low as 5 × 10-13 M. Bi2Se3 has robust surface states and improves the electrochemical signal-to-noise ratio, while the uniform ODA layer guides high-density ordered DNA, enhancing the sensitivity of the biosensor. Our work demonstrates that the ordered DNA/ODA/Bi2Se3 electrode surface has great application potential in the field of biosensing and disease diagnosis.

Risk of waning humoral responses after inactivated or subunit recombinant SARS-CoV-2 vaccination in patients with chronic diseases: Findings from a prospective observational study in China.

Heterogeneity of antibody responses has been reported in SARS-CoV-2 vaccination recipients with underlying diseases. We investigated the impact of the presence of comorbidities on the humoral response to SARS-CoV-2 vaccination in patients with chronic disease (PWCD) and assessed the effect of the number of comorbidities on the humoral response to vaccination. In this study, neutralizing antibodies (NAbs) and IgG antibodies against the receptor-binding domain (RBD-IgG) were monitored following a full-course vaccination. In total, 1400 PWCD (82.7%, inactivated vaccines; 17.3%, subunit recombinant vaccine) and 245 healthy controls (65.7% inactivated vaccines, 34.3% subunit recombinant vaccine) vaccinated with inactivated or subunit recombinant SARS-CoV-2 vaccines, were included. The seroconversion and antibody levels of the NAbs and RBD-IgG were different in the PWCD group compared with those in the control group. Chronic hepatitis B (odds ratio [OR]: 0.65; 95% confidence interval [CI]: 0.46-0.93), cancer (OR: 0.65; 95% CI: 0.42-0.99), and diabetes (OR: 0.50; 95% CI: 0.28-0.89) were associated with lower seroconversion of NAbs. Chronic kidney disease (OR: 0.29; 95% CI: 0.11-0.76), cancer (OR: 0.38; 95% CI: 0.23-0.62), and diabetes (OR: 0.37; 95% CI: 0.20-0.69) were associated with lower seroconversion of RBD-IgG. Only the presence of autoimmune disease showed significantly lower NAbs and RBD-IgG titers. Patients with most types of chronic diseases showed similar responses to the controls, but humoral responses were still significantly associated with the presence of ≥2 coexisting diseases. Our study suggested that humoral responses following SARS-CoV-2 vaccination are impaired in patients with certain chronic diseases.

Diagnosis of infantile subglottic hemangioma and the effect of oral propranolol.

OBJECTIVES: To investigate the clinical characteristics of infantile subglottic hemangioma (SGH), and to observe the safety and efficacy of propranolol in the treatment of SGH. METHODS: The data of 21 children diagnosed with SGH and treated with propranolol in our hospital from March 2013 to January 2021 were retrospectively analyzed and followed up. RESULTS: Among the 21 cases, there were 7 males and 14 females. SGH was found 11 left-sided, 9 right-sided and 1 bilateral-sided. The clinical manifestations included stridor (13/21), respiratory distress (6/21), barking cough (5/21), feeding difficulty (4/21), three concave sign (4/21), cyanosis (2/21) and hoarseness (1/21). 8 patients had multiple cutaneous hemangiomas. The age of presentation ranged from 1 to 8 months, with a median of 1.1 months. 18 cases (85.7 %) had a history of misdiagnosis, 14 bronchitis/pneumonia, 5 laryngomalacia, 2 laryngeal obstruction and 1 asthma. The median ages at diagnosis were 3 months, with a range of 1.2-28 months. The treatment duration ranged from 6 to 25.6 months, with an average of (14.3 ± 4.9) months. Age at termination of treatment ranged from 9 to 38 months, with a median of 18.6 months, and only 2 cases were beyond 2 years old at that time. No adverse side effects from propranolol therapy occurred and all 21 cases were cured. CONCLUSIONS: We advocate a strong index of suspicion for SGH presenting with respiratory symptoms under 2 years old who has poor effect or repeated condition after routine treatment. Laryngoscopy combined with contrast-enhanced CT can confirm the diagnosis of SGH. Oral propranolol is safe and effective, and that early diagnosis and intervention of propranolol without further delay are crucial to the successful management. We advocate continue propranolol treatment beyond 18 months of age, furthermore, 2 years old may be the best time for therapy termination.

Safety and immunogenicity of inactivated SARS-CoV-2 vaccines in people with gastrointestinal cancer.

OBJECTIVES: This study aimed to evaluate the safety and immunogenicity of inactivated COVID-19 vaccines in patients with gastrointestinal cancer (GI) cancer. The role of memory B cells (MBCs) in the humoral response to COVID-19 vaccination was also investigated. METHODS: In this prospective observational study, GI cancer patients and healthy individuals who had received 2 doses of inactivated COVID-19 vaccines were included. The data regarding adverse effects, serum anti-receptor binding domain (RBD)-IgG, neutralizing antibodies (NAbs), and frequencies of MBCs were collected prospectively. RESULTS: The inactivated COVID-19 vaccines were safe and well tolerated. Serum anti-RBG-IgG and NAbs were lower for cancer patients. Old age, high ASA score, and receiving active chemotherapy were risk factors for lower antibody titers. The frequencies of activated and resting MBCs decreased in (17.45% vs 38.11%, P = 0.002; 16.98% vs 34.13%, P = 0.023), while the frequencies of intermediate and atypical MBCs increased in cancer patients (40.06% vs 19.87%, P = 0.010; 25.47% vs 16.61%, P = 0.025). The serum antibody titer decreased gradually during follow-up but increased when a booster vaccine was given. CONCLUSION: The inactivated COVID-19 vaccines were well tolerated in patients with GI cancer but with lower immunogenicity. The subpopulations of MBCs were disordered in cancer patients, and a booster vaccine may be prioritized for them.

Traveler Pro-social Behaviors at Heritage Tourism Sites.

This study aimed to explain the development of tourists' pro-social intentions during heritage tourism within the pandemic context by combining the norm activation model (NAM) and two significant variables in the theory of planned behavior (TPB). The quantitative data analysis results indicated that the proposed hypotheses have been partially supported, which resonated and enriched the existing studies on COVID-19-related pro-social tourism and tourist behaviors from a theoretical angle. Based on the research outcomes, the corresponding managerial implications for heritage tourism practitioners and meaningful references for future researchers to promote sustainable and pro-social heritage tourism products have been discussed.

CoVac501, a self-adjuvanting peptide vaccine conjugated with TLR7 agonists, against SARS-CoV-2 induces protective immunity.

Safe, effective, and economical vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed to achieve adequate herd immunity and end the pandemic. We constructed a novel SARS-CoV-2 vaccine, CoVac501, which is a self-adjuvanting peptide vaccine conjugated with Toll-like receptor 7 (TLR7) agonists. The vaccine contains immunodominant peptides screened from the receptor-binding domain (RBD) and is fully chemically synthesized. It has been formulated in an optimized nanoemulsion formulation and is stable at 40 °C for 1 month. In non-human primates (NHPs), CoVac501 elicited high and persistent titers of protective neutralizing antibodies against multiple RBD mutations, SARS-CoV-2 original strain, and variants (B.1.1.7 and B.1.617.2). Specific peptides booster immunization against the B.1.351 variant has also been shown to be effective in improving protection against B.1.351. Meanwhile, CoVac501 elicited the increase of memory T cells, antigen-specific CD8+ T-cell responses, and Th1-biased CD4+ T-cell immune responses in NHPs. Notably, at an extremely high SARS-CoV-2 challenge dose of 1 × 107 TCID50, CoVac501 provided near-complete protection for the upper and lower respiratory tracts of cynomolgus macaques.

Liver abscess in the caudate lobe caused by a fishbone and treated by laparoscopy: a case report.

BACKGROUND: Ingestion of fish bones leading to gastric perforation and inducing abscess formation in the caudate lobe of the liver is very rare. CASE PRESENTATION: A 67-year-old man presented to our hospital with a 2-day history of subxiphoid pain. There were no specific symptoms other than pain. Laboratory tests showed only an increase in the number and percentage of neutrophils. Contrast-enhanced Computerized tomography (CT) of the abdomen showed two linear dense opacities in the gastric cardia, one of which penetrated the stomach and was adjacent to the caudate lobe of the liver, with inflammatory changes in the caudate lobe. We finally diagnosed his condition as a caudate lobe abscess secondary to intestinal perforation caused by a fishbone based on the history and imaging findings. The patient underwent 3D laparoscopic partial caudate lobectomy, incision and drainage of the liver abscess, and fishbone removal. The procedure was successful and we removed the fishbone from the liver. The patient was discharged on the 9th postoperative day without other complications. CONCLUSIONS: Liver abscess caused by foreign bodies requires multidisciplinary treatment. Especially when located in the caudate lobe, we must detect and remove the cause of the abscess as early as possible. Foreign bodies that perforate the gastrointestinal tract can penetrate to the liver and cause abscess formation, as in this case. When exploring the etiology of liver abscesses, we should investigate the general condition, including the whole gastrointestinal tract.

Serum amylase elevation is associated with adverse clinical outcomes in patients with coronavirus disease 2019.

OBJECTIVE: Hyperamylasemia was found in a group of patients with COVID-19 during hospitalization. However, the evolution and the clinical significance of hyperamylasemia in COVID-19, is not well characterized. DESIGN: In this retrospective cohort study, the epidemiological, demographic, laboratory, treatment and outcome information of 1,515 COVID-19 patients with available longitudinal amylase records collected from electronic medical system were analyzed to assess the prevalence and clinical significance of hyperamylasemia in this infection. Associated variables with hyperamylasemia in COVID-19 were also analyzed. RESULTS: Of 1,515 patients, 196 (12.9%) developed hyperamylasemia, among whom 19 (1.3%) greater than 3 times upper limit of normal (ULN) and no clinical acute pancreatitis was seen. Multivariable ordered logistic regression implied older age, male, chronic kidney disease, several medications (immunoglobin, systemic corticosteroids, and antifungals), increased creatinine might be associated with hyperamylasemia during hospitalization. Restricted cubic spline analysis indicated hyperamylasemia had a J-shaped association with all-cause mortality and the estimated hazard ratio per standard deviation was 2.85 (2.03-4.00) above ULN. Based on the multivariable mixed-effect cox or logistic regression model taking hospital sites as random effects, elevated serum amylase during hospitalization was identified as an independent risk factor associated with in-hospital death and intensive complications, including sepsis, cardiac injury, acute respiratory distress syndrome, and acute kidney injury. CONCLUSIONS: Elevated serum amylase was independently associated with adverse clinical outcomes in COVID-19 patients. Since early intervention might change the outcome, serum amylase should be monitored dynamically during hospitalization.

Enhancing Traceability of Infectious Diseases: A Blockchain-Based Approach.

The global pandemic of COVID-19 has brought significant attentions to three important features of disease direct reporting systems: traceability, reliability, and effectiveness. A traditional disease direct reporting system has a central node of control, with a hierarchical structure that goes up from locals (cities and counties) to regions and eventually reaches a central data repository. Such systems are often prone to easy data loss, arbitrary or unauthorized data changes, and unreliable traceability to individual nodes. Blockchain, as a new disruptive technology, provides a potential solution. Leveraging blockchain's features of decentralization, unforgeability, whole-process traceability, we develop a method for disease information tracing with key components including infectious disease information collection, information chain-style storage, and information query. Our blockchain-based infectious disease traceability method can promptly collect disease information and form the disease information time series blockchain. We demonstrate that the information chain constructed is authentic and transparent, and it can be queried and maintained at any node in the system. Consequently, the infectious disease information on the blockchain can be monitored and queried any time, thereby greatly facilitating the tracing of the propagation paths of infectious diseases.

Association of liver abnormalities with in-hospital mortality in patients with COVID-19.

BACKGROUND & AIMS: The evolution and clinical significance of abnormal liver chemistries and the impact of hepatitis B infection on outcome in patients with COVID-19 is not well characterized. This study aimed to explore these issues. METHODS: This large retrospective cohort study included 2,073 patients with coronavirus disease 2019 (COVID-19) and definite outcomes in Wuhan, China. Longitudinal liver function tests were conducted, with associated factors and risk of death determined by multivariate regression analyses. A prognostic nomogram was formulated to predict the survival of patients with COVID-19. The characteristics of liver abnormalities and outcomes of patients with COVID-19, with and without hepatitis B, were compared after 1:3 propensity score matching. RESULTS: Of the 2,073 patients, 1,282 (61.8%) had abnormal liver chemistries during hospitalization, and 297 (14.3%) had a liver injury. The mean levels of aspartate aminotransferase (AST) and direct bilirubin (D-Bil) increased early after symptom onset in deceased patients and showed disparity compared to levels in discharged patients throughout the clinical course of the disease. Abnormal AST (adjusted hazard ratio [HR] 1.39; 95% CI 1.04-1.86, p = 0.027) and D-Bil (adjusted HR 1.66; 95% CI 1.22-2.26; p = 0.001) levels at admission were independent risk factors for mortality due to COVID-19. A nomogram was established based on the results of multivariate analysis and showed sufficient discriminatory power and good consistency between the prediction and the observation. HBV infection in patients did not increase the risk of poor COVID-19-associated outcomes. CONCLUSIONS: Abnormal AST and D-Bil levels at admission were independent predictors of COVID-19-related mortality. Therefore, monitoring liver chemistries, especially AST and D-Bil levels, is necessary in hospitalized patients with COVID-19. LAY SUMMARY: Liver test abnormalities (in particular elevations in the levels of aspartate aminotransferase [AST] and direct bilirubin [D-Bil]) were observed after symptom onset in patients who went on to die of coronavirus disease 2019 (COVID-19). Abnormal levels of AST and D-Bil at admission were independent predictors of COVID-19-related mortality. HBV infection in patients did not increase the risk of poor COVID-19-associated outcomes.