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Simultaneous acquisition is a construction method that has been proposed in recent years to meet the requirements of ultra-large-scale and high-precision seismic exploration. Such method is highly efficient and can significantly reduce exploration costs by saving manpower and material resources, being extensively used in offshore exploration and several foreign seismic exploration projects. The data deblending step is a significant part of the operation of simultaneous acquisition, which directly affects the acquired data quality, and is a key factor for the success of oil and gas exploration. The simultaneous use of multiple seismic sources can generate blended noise with a random distribution in non-shot-gather datasets. However, the useful signal exhibits strong coherence, making it possible to separate the non-used wavefield from the blended data. Although the blended noise is randomly distributed in non-shot-gather datasets, it also has characteristics that are different from normal ambient noise, and its kinematic and dynamical characteristics are almost similar to the useful signal. As such, traditional filtering methods are not applicable, especially in the case of strong background noise. In the present study, simultaneous acquisition was introduced, the principle of data deblending using CNN was analyzed, and a data deblending method based on an improved version of GoogLeNet was established. The experimental results show that the trained network model could quickly and effectively separate the mixed wavefield from blended data, and achieve the expected useful signal.

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Bloodstream infection (BSI) caused by bacteria is highly pathogenic and lethal, and easily develops whole-body inflammatory state. Immediate identification of disease-causing bacteria can improve patient prognosis. Traditional testing methods are not only time-consuming, but such tests are limited to laboratories. Recombinase polymerase amplification combined with lateral flow dipstick (RPA-LFD) holds great promise for rapid nucleic acid detection, but the uncapping operation after amplification easily contaminates laboratories. Therefore, the establishment of a more effective integrated isothermal amplification system has become an urgent problem to be solved. In this study, we designed and fabricated a hermetically sealed integrated isothermal amplification system. Combining with this system, a set of RPA-LFD assays for detecting S. aureus, K. peneumoniae, P. aeruginosa, and H. influenza in BSI were established and evaluated. The whole process could be completed in less than 15 min and the results can be visualized by the naked eye. The developed RPA-LFD assays displayed a good sensitivity, and no cross-reactivity was observed in seven similar bacterial genera. The results obtained with 60 clinical samples indicated that the developed RPA-LFD assays had high specifcity and sensitivity for identifying S. aureus, K. peneumoniae, P. aeruginosa, and H. influenza in BSI. In conclusion, our results showed that the developed RPA-LFD assay is an alternative to existing PCR-based methods for detection of S. aureus, K. peneumoniae, P. aeruginosa, and H. influenza in BSI in primary hospitals.

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In Open-domain Chinese Knowledge Base Question Answering (ODCKBQA), most common simple questions can be answered by a single relational fact in the knowledge base (KB). The abbreviations, aliases, and nesting of entities in Chinese question sentences, and the gap between them and the structured semantics in the knowledge base, make it difficult for the system to accurately return answers. This study proposes a semantic union model (SUM), which concatenates candidate entities and candidate relationships, using a contrastive learning algorithm to learn the semantic vector representation of question and candidate entity-relation pairs, and perform cosine similarity calculations to simultaneously complete entity disambiguation and relation matching tasks. It can provide information for entity disambiguation through the relationships between entities, avoid error propagation, and improve the system performance. The experimental results show that the system achieves a good average F1 of 85.94% on the dataset provided by the NLPCC-ICCPOL 2016 KBQA task.

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Lung cancer is the second most-frequently occurring cancer and the leading cause of cancer-associated deaths worldwide. Non-small cell lung cancer (NSCLC), the most common type of lung cancer is often diagnosed in middle or advanced stages and have poor prognosis. Diagnosis of disease at an early stage is a key factor for improving prognosis and reducing mortality, whereas, the currently used diagnostic tools are not sufficiently sensitive for early-stage NSCLC. The emergence of liquid biopsy has ushered in a new era of diagnosis and management of cancers, including NSCLC, since analysis of circulating tumor-derived components, such as cell-free DNA (cfDNA), circulating tumor cells (CTCs), cell-free RNAs (cfRNAs), exosomes, tumor-educated platelets (TEPs), proteins, and metabolites in blood or other biofluids can enable early cancer detection, treatment selection, therapy monitoring and prognosis assessment. There have been great advances in liquid biopsy of NSCLC in the past few years. Hence, this chapter introduces the latest advances on the clinical application of cfDNA, CTCs, cfRNAs and exosomes, with a particular focus on their application as early markers in the diagnosis, treatment and prognosis of NSCLC.

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Circulating tumor cells (CTCs) are cells shed from primary or metastatic tumors and spread into the peripheral bloodstream. Mutation detection in CTCs can reveal vital genetic information about the tumors and can be used for "liquid biopsy" to indicate cancer treatment and targeted medication. However, current methods to measure the mutations in CTCs are based on PCR or DNA sequencing which are cumbersome and time-consuming and require sophisticated equipment. These largely limited their applications especially in areas with poor healthcare infrastructure. Here we report a simple, convenient, and rapid method for mutation detection in CTCs, including an example of a deletion at exon 19 (Del19) of the epidermal growth factor receptor (EGFR). CTCs in the peripheral blood of NSCLC patients were first sorted by a double spiral microfluidic chip with high sorting efficiency and purity. The sorted cells were then lysed by proteinase K, and the E19del mutation was detected via real-time recombinase polymerase amplification (RPA). Combining the advantages of microfluidic sorting and real-time RPA, an accurate mutation determination was realized within 2 h without professional operation or complex data interpretation. The method detected as few as 3 cells and 1% target variants under a strongly interfering background, thus, indicating its great potential in the non-invasive diagnosis of E19del mutation for NSCLC patients. The method can be further extended by redesigning the primers and probes to detect other deletion mutations, insertion mutations, and fusion genes. It is expected to be a universal molecular diagnostic tool for real-time assessment of relevant mutations and precise adjustments in the care of oncology patients.

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The COVID-19 pandemic has spread worldwide, and rapid detection of the SARS-CoV-2 virus is crucial for infection surveillance and epidemic control. This study developed a centrifugal microfluidics-based multiplex reverse transcription recombinase polymerase amplification (RT-RPA) assay for endpoint fluorescence detection of the E, N, and ORF1ab genes of SARS-CoV-2. The microscope slide-shaped microfluidic chip could simultaneously accomplish three target genes and one reference human gene (i.e., ACTB) RT-RPA reactions in 30 min, and the sensitivity was 40 RNA copies/reaction for the E gene, 20 RNA copies/reaction for the N gene, and 10 RNA copies/reaction for the ORF1ab gene. The chip demonstrated high specificity, reproducibility, and repeatability. Chip performance was also evaluated using real clinical samples. Thus, this rapid, accurate, on-site, and multiplexed nucleic acid test microfluidic chip would significantly contribute to detecting patients with COVID-19 in low-resource settings and point-of-care testing (POCT) and, in the future, could be used to detect emerging new variants of SARS-CoV-2.

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BACKGROUND: Isothermal exponential amplification reaction (EXPAR) is an emerging amplification technique that is most frequently used to amplify microRNA (miRNA). However, EXPAR also exhibits non-specific background amplification in the absence of the targeted sequence, which limits the attainable assay sensitivity of EXPAR. METHODS AND RESULTS: A novel modified isothermal EXPAR based on circular amplification templates (cEXPAR) was developed in this study. The circular template consists of two same linear fragments that complement the target sequence, and these two linear fragments are separated by two nicking agent recognition sequences (NARS). Compared with the linear structure template, this circular template allows DNA or RNA fragments to be randomly paired with two repeated sequences and can be successfully amplified. This reaction system developed in this study could rapidly synthesize short oligonucleotide fragments (12-22 bp) through simultaneous nicking and displacement reactions. Highly sensitive chain reactions can be specifically triggered by as low as a single copy of target molecule, and non-specific amplification can be effectively eliminated in this optimized system. Moreover, the proposed approach applied to miRNA test can discriminate single-nucleotide variations between miRNAs. CONCLUSION: The newly developed cEXPAR assay provides a useful alternative tool for rapid, sensitive, and highly specific detection of miRNAs.

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Currently, using MATLAB Web App Server to deploy MATLAB Web applications for hosting and sharing interactive Web applications involves the following problems: slow loading of applications, incompatibility with some browser versions, and various shortcomings of deployment tools, such as poor scalability and difficulty in optimizing black boxes. These problems adversely affect the user experience. To address this situation, we propose the use of front-end technology to design application layouts and build an application hosting platform with front-end and back-end separation using Nginx and Python. This method is shown to be simple and efficient, and it can successfully overcome the aforementioned problems while providing new ideas for hosting and sharing.

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Microchips are fundamental tools for single-cell analysis. Although various microfluidic methods have been developed for single-cell trapping and analysis, most microchips cannot trap single cells deterministically for further analysis. In this paper, we describe a novel resistance-based microfluidic chip to implement deterministic single-cell trapping followed by immunofluorescence staining based on the least flow resistance principle. The design of a large circular structure before the constriction and the serpentine structure of the main channel made the flow resistance of the main channel higher than that of the trapping channel. Since cells preferred to follow paths with lower flow resistance, this design directed cells into the capture sites and improved single-cell trapping efficiency. We optimized the geometric parameters using numerical simulations. Experiments using A549 and K562 cell lines demonstrated the capability of our chip with (82.7 ± 2.4)% and (84 ± 3.3)% single-cell trapping efficiency, respectively. In addition, cells were immobilized at capture sites by applying the pulling forces at the outlet, which reduced the cell movement and loss and facilitated tracking of the cell in real time during the multistep immunofluorescence staining procedure. Due to the simple operation, high-efficiency single-cell trapping and lower cell loss, the proposed chip is expected to be a potential analytical platform for single tumor cell heterogeneity studies and clinical diagnosis.

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BACKGROUND: Coronavirus disease 2019 (COVID-19) is a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that brings a significant public health challenge. A rapid and simple method is necessary for testing suspected samples and screening the population. METHODS: To better monitor sample effectiveness, this study described a method to detect nucleocapsid protein gene (N gene) of SARS-CoV-2 and human ACTB gene employing real-time duplex reverse transcription multienzyme isothermal rapid amplification (RT-MIRA) assays. RESULTS: The established real-time duplex RT-MIRA assays showed that no cross-reactions were observed to other pathogens and the detection limit was 100 copies/reaction. Using simulated clinical samples to test established assays further and the amplification process took no more than 20 minutes at 42°C. CONCLUSIONS: RT-MIRA assays are faster and easier than reverse transcription real-time polymerase chain reaction (RT-PCR). It is expected to be further optimized and evaluated in the detection of SARS-CoV-2 confirmed cases.

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Circulating tumor cells (CTCs) play a crucial role in solid tumor metastasis, but obtaining high purity and viability CTCs is a challenging task due to their rarity. Although various works using spiral microchannels to isolate CTCs have been reported, the sorting purity of CTCs has not been significantly improved. Herein, we developed a novel double spiral microchannel for efficient separation and enrichment of intact and high-purity CTCs based on the combined effects of two-stage inertial focusing and particle deflection. Particle deflection relies on the second sheath to produce a deflection of the focused sample flow segment at the end of the first-stage microchannel, allowing larger particles to remain focused and entered the second-stage microchannel while smaller particles moved into the first waste channel. The deflection of the focused sample flow segment was visualized. Testing by a binary mixture of 10.4 and 16.5 µm fluorescent microspheres, it showed 16.5 µm with separation efficiency of 98% and purity of 90% under the second sheath flow rate of 700 µl min-1. In biological experiments, the average purity of spiked CTCs was 74% at a high throughput of 1.5 × 108 cells min-1, and the recovery was more than 91%. Compared to the control group, the viability of separated cells was 99%. Finally, we validated the performance of the double spiral microchannel using clinical cancer blood samples. CTCs with a concentration of 2-28 counts ml-1 were separated from all 12 patients' peripheral blood. Thus, our device could be a robust and label-free liquid biopsy platform in inertial microfluidics for successful application in clinical trials.

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Leukocytes have an essential role in patient clinical trajectories and progression. Traditional methods of leukocyte enrichment have many significant limitations for current applications. It is demonstrated a novel 3D printing leukocyte sorting accumulator that combines with centrifugation to ensure label-free initial leukocyte enrichment based on cell density and size. The internal structure of leukocyte sorting accumulator (revealed here in a new design, leukocyte sorting accumulator-3, upgraded from earlier models), optimizes localization of the buffy coat fraction and the length of the period allocated for a second centrifugation step to deliver a higher recovery of buffy coats than earlier models. Established methodological parameters were evaluated for reliability by calculating leukocyte recovery rates and erythrocyte depletion rates by both pushing and pulling methods of cell displacement. Results indicate that leukocyte sorting accumulator-3 achieves a mean leukocytes recovery fraction of 96.2 ± 2.38% by the pushing method of layer displacement. By the pulling method, the leukocyte sorting accumulator-3 yield a mean leukocytes recovery fraction of 94.4 ± 0.8%. New procedures for preliminary enrichment of leukocytes from peripheral blood that avoid cellular damage, as well as avert metabolic and phase cycle intervention, are required as the first step in many modern clinical and basic research assays.

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This paper describes a novel rotational paper-based analytical device (RPAD) to implement multi-step electrochemiluminescence (ECL) immunoassays. The integrated paper-based rotational valves can be easily controlled by rotating paper discs manually and this advantage makes it user-friendly to untrained users to carry out the multi-step assays. In addition, the rotational valves are reusable and the response time can be shortened to several seconds, which promotes the rotational paper-based device to have great advantages in multi-step operations. Under the control of rotational valves, multi-step ECL immunoassays were conducted on the rotational device for the multiplexed detection of carcinoembryonic antigen (CEA) and prostate specific antigen (PSA). The rotational device exhibited excellent analytical performance for CEA and PSA, and they could be detected in the linear ranges of 0.1-100 ng mL-1 and 0.1-50 ng mL-1 with detection limits down to 0.07 ng mL-1 and 0.03 ng mL-1, respectively, which were within the ranges of clinical concentrations. We hope this technique will open a new avenue for the fabrication of paper-based valves and provide potential application in clinical diagnostics.

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In this work, a novel rotational microfluidic paper-based device was developed to improve the accuracy and performance of the multiplexed colorimetric detection by effectively avoiding the diffusion of colorimetric reagent on the detection zone. The integrated paper-based rotational valves were used to control the connection or disconnection between detection zones and fluid channels. Based on the manipulation of the rotational valves, this rotational paper-based device could prevent the random diffusion of colorimetric reagent and reduce the error of quantitative analysis considerably. The multiplexed colorimetric detection of heavy metals Ni(II), Cu(II) and Cr(VI) were implemented on the rotational device and the detection limits could be found to be 4.8, 1.6, and 0.18mg/L, respectively. The developed rotational device showed the great advantage in improving the detection accuracy and was expected to be a low-cost, portable analytical platform for the on-site detection.

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Objective @# To investigate the changes of α2-macroglobulin in different stages of radiotherapy in patients with nasopharyngeal carcinoma, and to explore its feasibility as a marker of serum markers reflecting radiotherapy injury.@*Methods @#We collected the blood samples of 23 cases of newly diagnosed patients with nasopharyngeal carcinoma before the simple radiotherapy, the 10, 20, 30 and 33 times after simple radiotherapy, detected the α2- macroglobulin levels. The difference among the five stages was analysed by paired t-test using SPSS17.0 software package.@*Results @#The serum level of α2- macroglobulin elevated with the increase of number of radiotherapy. After 10 times’ radiotherapy, the serum α2-MG concentration in patients with nasopharyngeal carcinoma was significantly higher than that before radiotherapy (12.04 ± 5.72 vs. 10.81 ± 5.38 U/L), the difference was statistically significant (t=4.818, P < 0.05). After 20 times’ radiotherapy, the serum α2-MG concentration in patients with nasopharyngeal carcinoma was significantly higher than that before radiotherapy (12.26 ± 5.77 vs. 10.81 ± 5.38 U/L), and the difference was statistically significant (t=5.237, P < 0.001). After 30 times’ radiotherapy, the serum α2-MG concentration in patients with nasopharyngeal carcinoma was significantly higher than that before radiotherapy (12.91 ± 5.55 vs. 10.81 ± 5.38 U/L), the difference was statistically significant (t=6.076, P < 0.05). At the end of radiotherapy, the serum α2-MG concentration in nasopharyngeal carcinoma patients was significantly (13.43 ± 6.05 vs. 10.81 ± 5.38 U/L) higher than that before radiotherapy (t=5.189, P < 0.05).@*Conclusion@#The serum level of α2- macroglobulin changes with the radiotherapy, so it can be a serum marker reflecting the damage of maxilla induced by ionizing radiation.

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A novel electrochemiluminescent (ECL) aptasensor was proposed for the determination of thrombin (TB) using exonuclease-catalyzed target recycling and hybridization chain reaction (HCR) to amplify the signal. The capture probe was immobilized on an Au-GS-modified electrode through a Au-S bond. Subsequently, the hybrid between the capture probe and the complementary thrombin binding aptamer (TBA) was aimed at obtaining double-stranded DNA (dsDNA). The interaction between TB and its aptamer led to the dissociation of dsDNA because TB has a higher affinity to TBA than the complementary strands. In the presence of exonuclease, aptamer was selectively digested and TB could be released for target recycling. Extended dsDNA was formed through HCR of the capture probe and two hairpin DNA strands (NH2-DNA1 and NH2-DNA1). Then, numerous europium multiwalled carbon nanotubes (Eu-MWCNTs) could be introduced through amidation reaction between NH2-terminated DNA strands and carboxyl groups on the Eu-MWCNTs, resulting in an increased ECL signal. The multiple amplification strategies, including the amplification of analyte recycling and HCR, and high ECL efficiency of Eu-MWCNTs lead to a wide linear range (1.0×10(-12)-5.0×10(-9) mol/L) and a low detection limit (0.23 pmol/L). The method was applied to serum sample analysis with satisfactory results.

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