At present, PCR-based nucleic acid detection cannot meet the demands for coronavirus infectious disease (COVID-19) diagnosis. Two hundred fourteen confirmed COVID-19 patients who were hospitalized in ...the General Hospital of Central Theater Command of the People's Liberation Army between 18 January and 26 February 2020 were recruited. Two enzyme-linked immunosorbent assay (ELISA) kits based on recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, and their diagnostic feasibility was evaluated. Among the 214 patients, 146 (68.2%) and 150 (70.1%) were successfully diagnosed with the rN-based IgM and IgG ELISAs, respectively; 165 (77.1%) and 159 (74.3%) were successfully diagnosed with the rS-based IgM and IgG ELISAs, respectively. The positive rates of the rN-based and rS-based ELISAs for antibody (IgM and/or IgG) detection were 80.4% and 82.2%, respectively. The sensitivity of the rS-based ELISA for IgM detection was significantly higher than that of the rN-based ELISA. We observed an increase in the positive rate for IgM and IgG with an increasing number of days post-disease onset (d.p.o.), but the positive rate of IgM dropped after 35 d.p.o. The positive rate of rN-based and rS-based IgM and IgG ELISAs was less than 60% during the early stage of the illness, 0 to 10 d.p.o., and that of IgM and IgG was obviously increased after 10 d.p.o. ELISA has a high sensitivity, especially for the detection of serum samples from patients after 10 d.p.o., so it could be an important supplementary method for COVID-19 diagnosis.
Intelligent microfluidics is an emerging cross-discipline research area formed by combining microfluidics with machine learning. It uses the advantages of microfluidics, such as high throughput and ...controllability, and the powerful data processing capabilities of machine learning, resulting in improved systems in biotechnology and chemistry. Compared to traditional microfluidics using manual analysis methods, intelligent microfluidics needs less human intervention, and results in a more user-friendly experience with faster processing. There is a paucity of literature reviewing this burgeoning and highly promising cross-discipline. Therefore, we herein comprehensively and systematically summarize several aspects of microfluidic applications enabled by machine learning. We list the types of microfluidics used in intelligent microfluidic applications over the last five years, as well as the machine learning algorithms and the hardware used for training. We also present the most recent advances in key technologies, developments, challenges, and the emerging opportunities created by intelligent microfluidics.
Liquid metal co‐injected with electrolyte through a microfluidic flow‐focusing orifice forms droplets with diameters and production frequencies controlled in real time by voltage. Applying voltage to ...the liquid metal controls the interfacial tension via a combination of electrochemistry and electrocapillarity. This simple and effective method can instantaneously tune the size of the microdroplets, which has applications in composites, catalysts, and microsystems.
Microalgae not only play a vital role in the ecosystem but also hold promising commercial applications. Conventional methods of detecting and monitoring microalgae rely on field sampling followed by ...transportation to the laboratory for manual analysis, which is both time-consuming and laborious. Although machine learning (ML) algorithms have been introduced for microalgae detection in the laboratory, no integrated platform approach has yet emerged to enable real-time, on-site sampling and analysing. To solve this problem, here, we develop an automated and intelligent microfluidic platform (AIMP) that can offer automated system control, intelligent data analysis, and user interaction, providing an economical and portable solution to alleviate the drawbacks of conventional methods for microalgae detection and monitoring. We demonstrate the feasibility of the AIMP by detecting and classifying four microalgal species (
,
,
, and
) that exhibit varying sizes (from a few to hundreds of microns) and morphologies. The trained microalgae species detection network (MSDN, based on YOLOv5 architecture) achieves a high overall mean average precision at 0.5 intersection-over-union (mAP@0.5) of 92.8%. Furthermore, the versatility of the AIMP is demonstrated by long-term monitoring of astaxanthin production from
over a period of 30 days. The AIMP achieved 97.5% accuracy in the detection of
and 96.3% in further classification based on astaxanthin accumulation. This study opens up a new path towards microalgae detection and monitoring using portable intelligent devices, providing new ideas to accelerate progress in the ecological studies and commercial exploitation of microalgae.
Micro‐ to nanosized droplets of liquid metals, such as eutectic gallium indium (EGaIn) and Galinstan, have been used for developing a variety of applications in flexible electronics, sensors, ...catalysts, and drug delivery systems. Currently used methods for producing micro‐ to nanosized droplets of such liquid metals possess one or several drawbacks, including the lack in ability to control the size of the produced droplets, mass produce droplets, produce smaller droplet sizes, and miniaturize the system. Here, a novel method is introduced using acoustic wave‐induced forces for on‐chip production of EGaIn liquid‐metal microdroplets with controllable size. The size distribution of liquid metal microdroplets is tuned by controlling the interfacial tension of the metal using either electrochemistry or electrocapillarity in the acoustic field. The developed platform is then used for heavy metal ion detection utilizing the produced liquid metal microdroplets as the working electrode. It is also demonstrated that a significant enhancement of the sensing performance is achieved by introducing acoustic streaming during the electrochemical experiments. The demonstrated technique can be used for developing liquid‐metal‐based systems for a wide range of applications.
A miniaturized system for on‐chip mass production of EGaIn liquid metal microdroplets with controllable size using acoustic waves is developed. On the same platform, the produced liquid metal microdroplets are used as an electrochemical sensor for Pb2+ ion detection with an enhanced sensing performance. This technique can enable the development of liquid metal systems for a wide range of applications.
Abstract Active droplets play important roles in microfluidics, robotics, and micro‐electromechanical systems. As a special class of active droplets that are conductive, reactive, and of high surface ...tension, liquid metal droplets (LMDs) can be driven by electric‐field‐induced surface (Marangoni) flows to function as reconfigurable components in actuators, sensors, catalytic reactors, and antennas. Stimulating LMDs using an electric field induces concurrent electro‐hydrodynamic flows and electrochemical surface oxidation (passivation). It is however difficult to decouple these two effects which brings complexity in controlling LMD motions. To address this challenge, pulse time modulation (PTM) signals are used. PTM enables controlled LMD displacement by propelling the droplets forward during the voltage‐on phases and facilitating surface recovery from oxidation during the voltage‐off phases. Counterintuitively, by taking such intermittent “rests”, the LMDs effectively inhibit the unfavorable impact of oxidation, granting high motion controllability. Combining high‐speed imaging, motion tracking, machine learning, and electrochemical analysis, the study reveals how electro‐hydrodynamic flows and surface oxide formation/dissolution interplay to generate well‐defined motion regimes. The study further develops a quasi‐analytical model to describe droplet motions and designs a rotary LMD motor to showcase the versatility of the approach. This work provides the fundamental framework and viable strategy for designing innovative liquid metal‐based systems.
Patterning customized arrays of microscale Galinstan or EGaIn liquid metals enables the creation of a variety of microfabricated systems. Current techniques for creating microsized 3D structures of ...liquid metals are limited by the large dimension or low aspect ratio of such structures, and time‐consuming processes. Here, a novel technique for creating 3D microstructures of Galinstan using dielectrophoresis is introduced. The presented technique enables the rapid creation of Galinstan microstructures with various dimensions and aspect ratios. Two series of proof‐of‐concept experiments are conducted to demonstrate the capabilities of this technique. First, the 3D Galinstan microstructures are utilized as 3D microelectrodes to enhance the trapping of tungsten trioxide (WO3) nanoparticles flowing through a microfluidic channel. Second, the patterned Galinstan microstructures are utilized as microfins to improve the dissipation of heat within a microfluidic channel that is located onto a hot spot. The presented technique can be readily used for creating customized arrays of 3D Galinstan microstructures for a wide range of applications.
This work introduces a novel technique for creating 3D microstructures of Galinstan using dielectrophoresis. It enables the rapid formation of multiple microstructures with controllable diameters and aspect ratios. Proof‐of‐concept experiments are conducted by utilizing the patterned microstructures as 3D microelectrodes for enhancing the trapping of suspended nanoparticles, and as microfins to improve the convective heat transfer within a microfluidic channel.
We aimed to clarify comprehensively the safety profiles of anti-IL-5 drugs and pinpoint potential safety concerns that may arise in their post-marketing phase.
Two researchers conducted comprehensive ...searches of PubMed, EMBASE, Web of Science, and the Cochrane Library from inception to September 2022. Additionally, we investigated the FDA AE Reporting System for post-marketing adverse event (AE) reports related to anti-IL-5 drugs. The outcomes fulfilled the proportional reporting rate criteria and the Bayesian confidence propagation neural network.
We included 24 published studies in our analysis. The anti-IL-5 treatment group showed an incidence of AEs comparable to the placebo group, and it exhibited a significantly lower frequency of serious AEs. Common AEs were asthma, nasopharyngitis, headache, upper respiratory tract infection (URTI), and bronchitis. The post-marketing data included 28,478 case reports associated with the suspect drugs and 75 suspect safety observations affecting 16 system organ classes. New suspect observations included incomplete therapeutic product effect, URTIs, and pulmonary mass in reports related to mepolizumab. Reports associated with mepolizumab and benralizumab also indicated issues with incorrect technique in device usage and product issues.
Individual anti-IL-5 drugs' safety profiles largely matched their product inserts. We identified issues like improper device usage, product issue, and URTIs as potential concerns for mepolizumab and benralizumab. Additionally, all anti-IL-5 drugs showed signs of incomplete therapeutic effects.
Droplet‐based microfluidics represents a disruptive technology in the field of chemistry and biology through the generation and manipulation of sub‐microlitre droplets. To avoid droplet coalescence, ...fluoropolymer‐based surfactants are commonly used to reduce the interfacial tension between two immiscible phases to stabilize droplet interfaces. However, the conventional preparation of fluorosurfactants involves multiple steps of conjugation reactions between fluorinated and hydrophilic segments to form multiple‐block copolymers. In addition, synthesis of customized surfactants with tailored properties is challenging due to the complex synthesis process. Here, we report a highly efficient synthetic method that utilizes living radical polymerization (LRP) to produce fluorosurfactants with tailored functionalities. Compared to the commercialized surfactant, our surfactants outperform in thermal cycling for polymerase chain reaction (PCR) testing, and exhibit exceptional biocompatibility for cell and yeast culturing in a double‐emulsion system. This breakthrough synthetic approach has the potential to revolutionize the field of droplet‐based microfluidics by enabling the development of novel designs that generate droplets with superior stability and functionality for a wide range of applications.
Droplet‐based microfluidics reimagined using LRP‐synthesized fluorosurfactants. Improved stability, biocompatibility, and promising applications.
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