An effective long-wavelength fluorescent sensor for Cu2+ based on dibenzylidenehydrazine-bridged biphenylacrylonitrile.

Although numerous fluorescence sensors for Cu2+ have been presented, a long-wavelength sensor in aqueous media has rarely been reported as expected due to practical application requirements. In this work, a novel AIE molecule (DHBB) containing two biphenylacrylonitrile units bridged by dibenzylidenehydrazine was prepared. It possessed the merits of long-wavelength emission, good emission in aqueous media, and multiple functional groups for binding Cu2+. It exhibited good sensing selectivity for Cu2+ among all kinds of tested metal ions. The detection limit was as low as 1.08 × 10-7 M. The sensing mechanism was clarified as 1:1 stoichiometric ratio based on the binding cooperation of O and N functional groups of DHBB. The selective sensing ability for Cu2+ remained stable at pH = 5-9 and was influenced little by other metal ions. The Cu2+ sensing ability of DHBB was applied in real samples with 96% recovery rate. The bio-imaging experiment of living cells suggested that DHBB possessed not only good bio-imaging performance but also sensing ability for Cu2+ in living environments. This work suggested the good application prospect of DHBB to sense Cu2+ in real samples and living environment.

Comparison of the community-acquired pneumonia and COVID-19 at the early stage: findings from two cohort studies.

BACKGROUND: The current focus is largely on whole course medical management of coronavirus disease-19 (COVID-19) with real-time polymerase chain reaction (RT-PCR) and radiological features, while the mild cases are usually missed. Thus, combination of multiple diagnostic methods is urgent to understand COVID-19 fully and to monitor the progression of COVID-19. METHODS: laboratory variables of 40 mild COVID-19 patients, 30 patients with community-acquired pneumonia (CAP) and 32 healthy individuals were analyzed by principal component analysis (PCA), Kruskal test, Procrustes test, the vegan package in R, CCA package and receiver operating characteristic to investigate the characteristics of the laboratory variables and their relationships in COVID-19. RESULTS: The correlations between the laboratory variables presented a variety of intricate linkages in the COVID-19 group compared with the healthy group and CAP patient group. The prediction probability of the combination of lymphocyte count (LY), eosinophil (EO) and platelets (PLT) was 0.847, 0.854 for the combination of lactate (LDH), creatine kinase isoenzyme (CK-MB), and C-reactive protein (CRP), 0.740 for the combination of EO, white blood cell count (WBC) and neutrophil count (NEUT) and 0.872 for the combination of CK-MB and P. CONCLUSIONS: The correlations between the laboratory variables in the COVID-19 group could be a unique characteristic showing promise as a method for COVID-19 prediction and monitoring progression of COVID-19 infection.

Development and clinical evaluation of a rapid antibody lateral flow assay for the diagnosis of SARS-CoV-2 infection.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has quickly spread worldwide since its outbreak in December 2019. One of the primary measures for controlling the spread of SARS-CoV-2 infection is an accurate assay for its diagnosis. SARS-CoV-2 real-time PCR kits suffer from some limitations, including false-negative results in the clinic. Therefore, there is an urgent need for the development of a rapid antibody test kit for COVID-19 diagnosis. METHODS: The nuclear capsid protein (N) and spike protein 1 (S1) fragments of SARS-CoV-2 were expressed in Escherichia coli, and rapid antibody-based tests for the diagnosis of SARS-CoV-2 infection were developed. To evaluate their clinical applications, the serum from COVID-19 patients, suspected COVID-19 patients, recovering COVID-19 patients, patients with general fever or pulmonary infection, doctors and nurses who worked at the fever clinic, and health professionals was analyzed by the rapid antibody test kits. The serum from patients infected with Mycoplasma pneumoniae and patients with respiratory tract infection was further analyzed to test its cross-reactivity with other respiratory pathogens. RESULTS: A 47 kDa N protein and 67 kDa S1 fragment of SARS-CoV-2 were successfully expressed, purified, and renatured. The rapid antibody test with recombinant N protein showed higher positive rate than the rapid IgM antibody test with recombinant S1 protein. Clinical evaluation showed that the rapid antibody test kit with recombinant N protein had 88.56 % analytical sensitivity and 97.42 % specificity for COVID-19 patients, 53.48 % positive rate for suspected COVID-19 patients, 57.14 % positive rate for recovering COVID-19 patients, and 0.5-0.8 % cross-reactivity with other respiratory pathogens. The analytical sensitivity of the kit did not significantly differ in COVID-19 patients with different disease courses (p < 0.01). CONCLUSIONS: The rapid antibody test kit with recombinant N protein has high specificity and analytical sensitivity, and can be used for the diagnosis of SARS-CoV-2 infection combined with RT-PCR.

A novel risk factor for predicting anti-tuberculosis drug resistance in patients with tuberculosis complicated with type 2 diabetes mellitus.

OBJECTIVES: This study aimed to explore the relationship between glycosylated hemoglobin (HbA1c) and the risk of anti-tuberculosis (TB) drug resistance for TB-type 2 diabetes mellitus (T2DM) patients. METHODS: From March 2014 to June 2019, medical records from multiple centers were searched. Logistic regression analyses were performed. A predictive model for multidrug-resistance (MDR) was developed and validated. Calibration and discrimination of the model were assessed. RESULTS: Inconsistent results were found in the systemic review. A multicenter chart review with 657 records was thus conducted. The HbA1c <7% group and HbA1c ≥7% group had 390 and 267 patients, respectively. The HbA1c<7% group had a lower risk of developing rifampicin resistance, isoniazid resistance and MDR, with odd ratios (ORs) of 1.904 (p=0.001), 2.896 (p<0.001) and 3.228 (p<0.001), respectively. The between-group differences in the risk of anti-TB drug resistance were analyzed based on data from three provinces in China. After adding HbA1c grading, the predictive model for MDR (https://mengyuan.shinyapps.io/Shinyapp/) showed excellent capacity with an AUC of 75.4% in the training set (Sichuan and Gansu) and 73.9% in the internal validation set (Henan). The performances in calibration, prediction probabilities and net clinical benefit were significantly improved by HbA1c grading. CONCLUSIONS: HbA1c grading was an independent risk factor for isoniazid resistance and MDR in TB-T2DM patients.

Experimental Study on Dry Reforming of Biogas for Syngas Production over Ni-Based Catalysts.

Syngas production from dry reforming of biogas (DRB) is studied experimentally in this work. Ni/Al2O3, Pt/Al2O3, and Pt-Ni/Al2O3 are used as catalysts to examine the effect of CO2 content in biogas and H2O addition on DRB performance for reaction temperatures in the 600-800 °C range. It is found that the bimetallic Pt-Ni catalyst exhibits the best activity and thermal stability among the three types of catalysts studied due to better carbon deposition resistance. Because CO2 functions as the oxidant in combustion, CH4 conversion is enhanced when the biogas contains more CO2. One hundred percent CO2 conversion can be reached for biogas containing a less amount of CO2 at high temperatures. With H2O addition in DRB, the steam reforming of methane (SRM) reaction is the dominant reaction, resulting in higher H2 and CO yields with biogas containing lesser amounts of CO2. However, lower CH4 conversion and negative CO2 conversion do result. With higher CO2 content in the biogas, higher CH4 and CO2 conversions can be obtained. Lower yields of H2 and CO are obtained due to less SRM dominance. With H2O addition in biogas, the H2/CO ratio with a value greater than 1 can be obtained from DRB. It is also found that the H2/CO ratio with a value of 2.1 can be obtained for reactant composition with a molar ratio of CH4/CO2/H2O = 1:0.25:1 and reaction temperature of 800 °C.