Search

Abstract Background The in vitro stability assessment is essential for investigating the diagnostic accuracy of pleural biomarkers. This study aimed to investigate the long‐term stability of pleural fluid carcinoembryonic antigen (CEA) at −80°C to −70°C. In addition, we analyzed the effects of frozen storage on the diagnostic accuracy of CEA for malignant pleural effusion (MPE). Methods Pleural fluid CEA of participants in two prospective cohorts were stored at −80°C to −70°C for 1–3 years. The CEA level in the stored specimen was measured with an immunoassay, and its level in the fresh specimen was extracted from medical records. The Bland–Altman method, Passing‐Bablok regression, and Deming regression were used to analyze the agreement of CEA between the fresh and frozen pleural fluid. In addition, we used receiver operating characteristic (ROC) curves to evaluate the diagnostic accuracy of CEA in the fresh and frozen specimens for MPE. Results A total of 210 participants were enrolled. The median CEA levels in frozen and fresh pleural fluid specimens were similar (frozen, 2.32 ng/mL; fresh, 2.59 ng/mL; p 0.05 for all). No significant difference was observed between the area under the ROC curves of CEA in the fresh and frozen specimens (p > 0.05 for all). Conclusion Pleural fluid CEA is seemingly stable when stored at –80°C to −70°C for 1–3 years. Frozen storage does not significantly affect the diagnostic accuracy of CEA for MPE.

As one of the biomarkers of coagulation system-related diseases, the detection of thrombin is of practical importance. Thus, this study developed a portable biosensor based on a personal glucometer for rapid detection of thrombin activity. Fibrinogen was used for the detection of thrombin, and the assay principle was inspired by the blood coagulation process, where thrombin hydrolyzes fibrinogen to produce a fibrin hydrogel, and the amount of invertase encapsulated in the fibrin hydrogel fluctuates in accordance with the activity of thrombin in the sample solution. The quantitative assay is conducted by measuring the amount of unencapsulated invertase available to hydrolyze the substrate sucrose, and the signal readout is recorded using a personal glucometer. A linear detection range of 0–0.8 U/mL of thrombin with a limit of detection of 0.04 U/mL was obtained based on the personal glucometer sensing platform. The results of the selectivity and interference experiments showed that the developed personal glucometer sensing platform is highly selective and accurate for thrombin activity. Finally, the reliability of the portable glucometer method for rapid thrombin detection in serum samples was investigated by measuring the recovery rate, which ranged from 92.8% to 107.7%. In summary, the fibrin hydrogel sensing platform proposed in this study offers a portable and versatile means for detecting thrombin using a personal glucometer. This approach not only simplifies the detection process, but also eliminates the need for large instruments and skilled operators, and substantially reduces detection costs.

Background: Lung cancer is the most common cause of malignant pleural effusion (MPE). Serum human epididymis secretory protein 4 (HE4) is a useful diagnostic marker for lung cancer. Objective: This study aimed to evaluate the diagnostic accuracy of pleural fluid HE4 for MPE. Design: A prospective, double-blind diagnostic test accuracy study. Methods: Patients with undiagnosed pleural effusion were enrolled in two cohorts (Hohhot and Changshu). Electrochemiluminescence immunoassay was used to detect pleural fluid HE4. The diagnostic accuracy of HE4 was evaluated by a receiver operating characteristic (ROC) curve, and the net benefit of HE4 was assessed by a decision curve analysis (DCA). Results: A total of 66 MPEs and 86 benign pleural effusions (BPEs) were enrolled in the Hohhot cohort. In the Changshu cohort, 26 MPEs and 32 BPEs were enrolled. In both cohorts, MPEs had significantly higher pleural fluid HE4 than BPEs. The area under the ROC curve (AUC) of HE4 was 0.73 (95% CI: 0.64–0.81) in the Hohhot cohort and 0.79 (95% CI: 0.67–0.91) in the Changshu cohort. At a threshold of 1300 pmol/L, HE4 had sensitivities of 0.44 (95% CI: 0.33–0.56) in the Hohhot cohort and 0.54 (95% CI: 0.35–0.73) in the Changshu cohort. The corresponding specificities were 0.90 (95% CI: 0.83–0.95) in the Hohhot cohort and 0.94 (95% CI: 0.84–1.00) in the Changshu cohort. In subgroup analyses, HE4 had an AUC (95% CI) of 0.78 (0.71–0.85) in exudates and an AUC of 0.69 (0.57–0.81) in patients with negative effusion cytology. The DCA revealed that HE4 determination had a net benefit in both cohorts. Conclusion: Pleural fluid HE4 has moderate diagnostic accuracy for MPE and has net benefit in pleural effusion patients with unknown etiology.

This study was aimed to investigate the effect of vitamin E (Vit E) supplementation on endometrial thickness and pregnancy outcomes in infertile women. The literature was screened by two researchers and the data was extracted by searching published literature from 1999 to 2020 in the Cochrane library, PubMed, and Embase database. Seven clinical trials were included, with a total of 652 subjects. Here we found the mean endometrium was thicker in Vit E treatment group than that in the control group [SMD = 0.57, 95% CI (0.26, 0.87), P = 0.0002]. Subgroup analysis showed that no significant effect between administration of 400 IU (267 mg) or 100 mg Vit E per day. There was no significant difference between with or without Vit E on ongoing pregnancy rate [OR = 1.08, 95% CI (0.72, 1.62), P = 0.70]. The current evidence demonstrates that Vit E supplementation may increase endometrial thickness in women of reproductive age.

In this study, a copper hexacyanoferrate nanoparticle with excellent oxidase-mimetic behaviour has been synthesized through a simple precipitation method. The synthesized copper hexacyanoferrate nanoparticle has intrinsic oxidase-like activity, which can catalyze the chromogenic reaction of 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) through an O2•− reactive oxygen-species-participated process. On the other hand, K3[Fe(CN)6] can be reduced by ascorbic acid (AA) to produce K4[Fe(CN)6], thereby inhibiting the formation of the copper hexacyanoferrate nanoparticles. Furthermore, ascorbate oxidase (AAO) can catalyze the oxidation of AA to produce dehydroascorbic acid, which cannot reduce K3[Fe(CN)6]. Thus, a system for an AAO-regulated in situ formation of copper hexacyanoferrate nanoparticles was constructed by coupling a prepared copper hexacyanoferrate nanozyme with AA for the detection of AAO activity. This colorimetric sensing assay shows high sensitivity and selectivity for the detection of AAO activity (the limit of detection is 0.52 U/L) with a linear range of 1.1–35.7 U/L. Finally, the developed method was applied to detect the activity of AAO in normal human serum with a satisfactory sample spiked recovery (87.4–108.8%). In short, this study provides a good strategy for the construction of nanozyme-based multi-enzyme cascade-signal amplification assay.

Trend prediction based on sensor data in a multi-sensor system is an important topic. As the number of sensors increases, we can measure and store more and more data. However, the increase in data has not effectively improved prediction performance. This paper focuses on this problem and presents a distributed predictor that can overcome unrelated data and sensor noise: First, we define the causality entropy to calculate the measurement’s causality. Then, the series causality coefficient (SCC) is proposed to select the high causal measurement as the input data. To overcome the traditional deep learning network’s over-fitting to the sensor noise, the Bayesian method is used to obtain the weight distribution characteristics of the sub-predictor network. A multi-layer perceptron (MLP) is constructed as the fusion layer to fuse the results from different sub-predictors. The experiments were implemented to verify the effectiveness of the proposed method by meteorological data from Beijing. The results show that the proposed predictor can effectively model the multi-sensor system’s big measurement data to improve prediction performance.

1-butyl-3-methylimidazolium chloride ([Bmim]Cl) was synthesized by ultrasonic heating circumfluence method and used as the intermediate for preparing Fe-based ionic liquids (Fe-ILs). By introducing the ultrasonic oscillation, the structure of [Bmim]Cl was unaffected but the reaction was shortened, achieving a good yield. The prepared [Bmim]Cl was mixed with FeCl3·6H2O at different mole ratios to synthesize Fe-ILs. The characteristic results showed that Fe-ILs have excellent thermal stability and FeCl4 - is the principal anion in Fe-ILs. A ternary desulfurization solution consisted of prepared Fe-ILs, water, and ethanol was applied for the flue gas desulfurization. Different compositions of desulfurization solution have great effects on the desulfurization efficiency and water is an indispensable component for SO2 removal. Fe-ILs with different mole ratios of [Bmim]Cl to FeCl3·6H2O exhibit different SO2 removal activities. When the mass ratio of Fe-ILs, water, and ethanol is at 1:2:4, Fe-IL1 has the highest SO2 adsorption capacity of 69.35 mg/g while Fe-IL3 has the maximum SO4 2- conversion rate of 42.3%, indicating that the prepared Fe-ILs have dual functions of adsorbent and catalyst and are able to catalytically oxidize SO2 to form H2SO4 in the presence of O2 and H2O. [ABSTRACT FROM AUTHOR]