A microfluidic immunosensor for automatic detection of carcinoembryonic antigen based on immunomagnetic separation and droplet arrays.

Diagnosis of cancer by biomarkers plays an important role in human health and life. However, current laboratory techniques for detecting cancer biomarkers still require laborious and time-consuming operation by skilled operators and associated laboratory instruments. This work presents a colorimetric biosensor for the rapid and sensitive detection of carcinoembryonic antigen (CEA) based on an automated immunomagnetic separation platform and a droplet array microfluidic chip with the aid of an image analysis system. Immunomagnetic nanoparticles (MNPs) were used to capture CEA in the samples. CEA-detecting antibodies and horseradish peroxidase (HRP) were modified on polystyrene microspheres (PS), catalysing hydrogen peroxide and 3,3',5,5'-tetramethylbenzidine (TMB) as signal outputs. Color reaction data were analyzed to establish a CEA concentration standard curve. The movement of MNPs between droplets in the microfluidic chip is achieved using an automatically programmable magnetic control system. This colorimetric biosensor has been used for the simultaneous detection of six CEA samples ranging from 100 pg mL-1 to 100 ng mL-1 with a detection limit of 14.347 pg mL-1 in 10 min, following the linear equation: y = -4.773 ln(x) + 156.26 with a correlation of R2 = 0.9924, and the entire workflow can be completed within 80 minutes. The microfluidic immunosensor designed in this paper has the advantages of low cost, automation, low sample consumption, high throughput, and promising applications in biochemistry.

Rapid Detection and Analysis of Raman Spectra of Bacteria in Multiple Fields of View Based on Image Stitching Technique.

BACKGROUND: Due to antibiotic abuse, the problem of bacterial resistance is becoming increasingly serious, and rapid detection of bacterial resistance has become an urgent issue. Because under the action of antibiotics, different active bacteria have different metabolism of heavy water, antibiotic resistance of bacteria can be identified according to the existence of a C-D peak in the 2030-2400 cm-1 range in the Raman spectrum. METHODS: To ensure data veracity, a large number of bacteria need to be detected, however, due to the limitation of the field of view of the high magnification objective, the number of single cells in a single field of view is very small. By combining an image stitching algorithm, image recognition algorithm, and processing of Raman spectrum and peak-seeking algorithm, can identify and locate single cells in multiple fields of view at one time and can discriminate whether they are Antimicrobial-resistant bacteria. RESULTS: In experiments 1 and 2, 2706 bacteria in 9 × 11 fields of view and 2048 bacteria in 11 × 11 fields of view were detected. Results showed that in experiment 1, there are 1137 antibiotic-resistant bacteria, accounting for 42%, and 1569 sensitive bacteria, accounting for 58%. In experiment 2, there are 1087 antibiotic-resistant bacteria, accounting for 53%, and 961 sensitive bacteria, accounting for 47%. It showed excellent performance in terms of speed and recognition accuracy as compared to traditional manual detection approaches. And solves the problems of low accuracy of data, a large number of manual experiments, and low efficiency due to the small number of single cells in the high magnification field of view and different peak-seeking parameters of different Raman spectra. CONCLUSIONS: The detection and analysis method of bacterial Raman spectra based on image stitching can be used for unattended, automatic, rapid and accurate detection of single cells at high magnification with multiple fields of view. With the characteristics of automatic, high-throughput, rapid, and accurate identification, it can be used as an unattended, universal and non-invasive means to measure antibiotic-resistant bacteria to screen for effective antibiotics, which is of great importance for studying the persistence and spread of antibiotics in bacterial pathogens.

Multiscale characterization of seawater pipe erosion of B10 copper-nickel alloy welded joints.

In seawater pipeline, the welding joint is a non-uniform structure composed of welding seam, base metal and heat affected zone. It has inhomogeneity in chemical composition, organizational structure, residual stress, etc. As local defects and high turbulence accelerate corrosion, the welding joint is often the weakest link in pipeline corrosion. Herein, the electrochemical corrosion behavior of B10 alloy welded joint in flowing seawater is studied from macroscopic and submicroscopic viewpoints using AC impedance, linear polarization, array electrode and morphological characterization. The results reveal that the corrosion rate of weld metal (WM), base metal (BM) and heat-affected zone (HAZ) decreased with the increase of time. Combined with SEM and EDS analysis, it can be seen that the increase in time led to the decomposition and accumulation of corrosion products, which gradually enhanced the corrosion resistance of welded joints. At the submicroscopic scale, WM acts as a cathode to mitigate corrosion during the later stages of high flow rate.

Characterization of Corrosion Behavior of TA2 Titanium Alloy Welded Joints in Seawater Environment.

Titanium alloy has been widely used in Marine pipeline system because of its excellent corrosion resistance. However, there are differences in microstructure and electrochemical properties because of the heterogeneous structure of the welded joint, the corrosion behavior is often different. In this paper, the corrosion behavior of TA2 titanium alloy welded joint in seawater at different temperatures was studied by traditional macro electrochemical test analysis combined with microelectrode array test and surface morphology analysis. Conventional macroscopic electrochemical analysis results show that the corrosion resistance of heat-affected zone is always the best, followed by the base metal and the weld. And the higher the temperature, the easier the formation of passivation film. The results of microelectrode array test show that the heat-affected zone is always the cathode region of the whole welded joint, and part of the cathode near the base metal region has the largest current density, which acts as the main cathode to slow down corrosion. At slightly higher temperatures, the polarity deflection will occur in the base metal zone and weld zone due to the different formation speeds of passivation film in early corrosion stage. With the prolongation of corrosion time, the base metal eventually becomes the cathode zone and the weld zone eventually becomes the anode zone.

Immunotherapeutic approaches in EBV-associated nasopharyngeal carcinoma.

Epstein-Barr virus (EBV) was the first tumor virus in humans. Nasopharyngeal carcinoma (NPC) accounts for approximately 60% of the 200,000 new tumor cases caused by EBV infection worldwide each year. NPC has an insidious onset and is highly malignant, with more than 70% of patients having intermediate to advanced disease at the time of initial diagnosis, and is strongly implicated in epithelial cancers as well as malignant lymphoid and natural killer/T cell lymphomas. Over 90% of patients with confirmed undifferentiated NPC are infected with EBV. In recent decades, much progress has been made in understanding the molecular mechanisms of NPC and developing therapeutic approaches. Radiotherapy and chemotherapy are the main treatment options for NPC; however, they have a limited efficacy in patients with locally advanced or distant metastatic tumors. Tumor immunotherapy, including vaccination, adoptive cell therapy, and immune checkpoint blockade, represents a promising therapeutic approach for NPC. Significant breakthroughs have recently been made in the application of immunotherapy for patients with recurrent or metastatic NPC (RM-NPC), indicating a broad prospect for NPC immunotherapy. Here, we review important research findings regarding immunotherapy for NPC patients and provide insights for future research.

In silico characterization of bla NDM-harboring plasmids in Klebsiella pneumoniae.

Klebsiella pneumoniae is a primary culprit of antibiotic-resistant nosocomial infections worldwide, and infections caused by NDM-producing strains are a major threat due to limited therapeutic options. The majority of bla NDM cases occur on plasmids; therefore, we explored the relationships between plasmids and bla NDM genes in K. pneumoniae by analyzing the variants of bla NDM, replicon types, conjugative transfer regions of 171 bla NDM-harboring plasmids from 4,451 K. pneumoniae plasmids. Of the nine identified bla NDM variants, bla NDM-1 (73.68%) and bla NDM-5 (16.37%) were the most dominant. Over half of the bla NDM-harboring plasmids of K. pneumoniae were classified into IncF plasmids. IncX3 single-replicon plasmids (46-57 kb) carried genes encoding relaxases of the MOBP family, T4CP genes of the VirD4/TraG subfamily, and VirB-like T4SS gene clusters, which were mainly geographically distributed in China. We found 10 bla NDM-harboring IncN plasmids (38.38-63.05 kb) carrying the NW-type origin of transfer (oriT) regions, genes coding for relaxases of MOBF family, genes encoding T4CPs of the TrwB/TraD subfamily, and Trw-like T4SS gene clusters, which were also mainly geographically distributed in China. Moreover, we identified 21 IncC plasmids carrying bla NDM-1 (140.1-329.2 kb), containing the A/C-type oriTs, genes encoding relaxases of MOBH family, genes encoding T4CPs belonging to TrwB/TraD subfamily, and Tra_F-like T4SS gene clusters. The bla NDM-harboring IncC plasmids were widely geographically distributed all over the world, mainly in the United States, China and Viet Nam. These findings enhance our understanding of the diversity of bla NDM-harboring plasmids in K. pneumoniae.

[Analysis of related factors between sudden sensorineural hearing loss and serum indices base on artificial intelligence and big data].

Objective:The etiology and pathophysiologic mechanism of sudden sensorineural hearing loss are undefined. We will use artificial intelligence and big data methods to explore the correlation between sudden sensorineural hearing loss and serum indices. Method:A total of 1218 patients with sudden deafness admitted to Sun Yat-sen Memorial Hospital were selected as the experimental group, 95 861 healthy subjects were randomly selected as the control group at the same period. Serum biochemical indexes in two groups were collected and analyzed by TreeNet and CART machine learning algorithms, to screen out highly correlated indicators with sudden sensorineural hearing loss and dig out a set of clinical features for people with high risk of sudden sensorineural hearing loss. Result:It was found that high prevalence rate of sudden sensorineural hearing loss is related to eosinophils, reticulocyte and fibrinogen. The areas under the receiver operator characteristic curves（ROC-AUC） were exploited to evaluate the prediction performance of TreeNet model. Overall the TreeNet model has provided high predictive ability by ROC curve, achieving AUC of 0.99, both recall and accuracy rate of 99.90%. Conclusion:There is significant difference between sudden deadness and normal people in serum biochemical indexes. Eosinophil is the first important indicator to distinguish sudden sensorineural hearing loss. Treenet model has important referenced significance for the screening and diagnosis of sudden sensorineural hearing loss.

[Clinical trial of treatment of laryngeal cancer by recombinant adenovirus p53 combined with chemotherapy].

OBJECTIVE: To evaluate the effectiveness of recombinant adenovirus p53 injection (rAd2p53) combined with cisplatin plus 5-fluorouracil regimen in treating laryngeal carcinoma. METHOD: Tumour animal models were established in the back of mice with Hep-2 cell line. Recombinant adenovirus p53 injection (rAd2p53) were transduced to tumor-bearing mouse by direct intratumoral injection combine with cisplatin plus 5-fluorouracil ivgtt. The control group 1 was given recombinant adenovirus p53 injection (rAd2p53) simplex. The control group 2 was administered with cisplatin plus 5-fluorouracil ivgtt simplex. Then compare the diameters of pro-treatment with that of post-treatment and test group with controls. RESULT: Tumor growth was significantly inhibited following combined rAd2p53 gene therapy with cisplatin plus 5-fluorouracil chemotherapy compared to single rAd2p53 gene therapy and cisplatin plus 5-fluorouracil chemotherapy controls. CONCLUSION: Local injection of rAd2p53 combined with cisplatin plus 5-fluorouracil chemotherapy is a promising treatment to laryngeal cancer.