国际突发公共卫生事件研究发展现状及演进路径：基于文献计量的综述与建议

利用CiteSpace软件分析该领域的研究现状与热点,对Web of Science数据库中2010-2019年突发公共卫生事件领域共5412篇相关文献进行核心国家分析、期刊共被引分析、文献共被引分析、关键词共现分析和关键词突发性检测.研究发现,突发公共卫生事件研究热点领域为传染病学、急诊医学、应急管理和空气污染,其中有关引发重大传染病疫情的病毒研究一直是研究的热点.     

Evaluation of sevafilachek immunoassays and rapid ICT-filariasis test for detection of bancroftian filariasis

A comparative analysis was made on the utility of SEVAFILACHEK-stick based immunoassays and commercially available ICT-filariasis test to detect active infection in different groups of bancroftian filariasis. The SEVAFILACHEK immunoassays were found to be useful to detect filarial infection in microfilaraemia and in a significant number of clinical filarial cases with acute, chronic and occult clinical manifestations. In the clinical cases, microfilariae are not usually detected in peripheral circulation. Employing SEVAFILACHEK assays 6 and 5 of the 7 samples of patients with chronic filarial disease, and 6 and 5 of 6 microfilaraemic cases gave positivity for filarial IgG antibodies and antigen respectively. Four of the 6 occult filarial samples were positive for antibodies and antigen. Filarial antigen was detected by ICT-filariasis test in blood samples of all the 6 microfilariaemic cases, 1 chronic filarial and 2 occult filarial samples. The main advantage of ICT assay is its rapid format and convenience for field use.     

On-chip antibody immobilization for on-demand and rapid immunoassay on a microfluidic chip

Immunoassay is one of the important applications of microfluidic chips and many methodologies were reported for decreasing sample∕reagent volume, shortening assay time, and so on. Micro-enzyme-linked immunosorbent assay (micro-ELISA) is our method that utilizes packed microbeads in the microfluidic channel and the immunoreactions are induced on the beads surface. Due to the large surface-to-volume ratio and small analytical volume, excellent performances have been verified in assay time and sample∕reagent volume. In order to realize the micro-ELISA, one of the important processes is the immobilization of antibody on the beads surface. Previously, the immobilization process was performed in a macroscale tube by physisorption of antibody, and long time (2 h) and large amount of antibody (or high concentration) were required for the immobilization. In addition, the processes including the reaction and washing were laborious, and changing the analyte was not easy. In this research, we integrated the immobilization process into a microfluidic chip by applying the avidin-biotin surface chemistry. The integration enabled very fast (1 min) immobilization with very small amount of precious antibody consumption (100 ng) for one assay. Because the laborious immobilization process can be automatically performed on the microfluidic chip, ELISA method became very easy. On-demand immunoassay was also possible just by changing the antibodies without using large amount of precious antibodies. Finally, the analytical performance was investigated by measuring C-reactive protein and good performance (limit of detection <20 ng∕ml) was verified.     

New age adjuvants and delivery systems for subunit vaccines

The dramatic advancements in the field of vaccinology has led to the formulation of chemically well defined vaccines composed of synthetic peptides and recombinant proteins derived from the immunologically dominant regions of the pathogens. Though these subunit vaccines are safer compared to the traditional vaccines they are known to be poorly immunogenic. This necessitates the use of adjuvants to enhance the immunogenicity of these vaccine formulations. The most common adjuvant for human use is alum. Research in the past has focused on the development of systemic immunity using conventional immunization protocols. In the present are, the emphasis is on the development and formulation of alternative adjuvants and delivery systems in generating systemic as well as mucosal immunity. This review mainly focuses on a variety of adjuvants (particulate as well as non-particulate) used with protective antigens of HIV, malaria, plague, leprosy using modified delivery vehicles. The experience of our laboratory and other researchers in this field clearly proves that these new age adjuvants and delivery systems undoubtedly generate enhanced immune response-both humoral and cell mediated. The choice of antigens, the nature of adjuvant used and the mode of delivery employed have a profound effect on the type of immune response generated. Besides the quantity, the quality of the antibodies generated also play a vital role in protection against these diseases. Some of the adjuvants and delivery systems used promoted high titre and affinity antibodies, which were shown to be cytophilic in nature, an important criteria in providing protection to the host. Thus the studies on these adjuvants/delivery systems with respect to various infectious diseases indicate their active role in efficient modulation of immune response along with safety and permissibility.     

Pushbutton-activated microfluidic cartridge as a user-friendly sample preparation tool for diagnostics

Microfluidic technologies have several advantages in sample preparation for diagnostics but suffer from the need for an external operation system that hampers user-friendliness. To overcome this limitation in microfluidic technologies, a number of user-friendly methods utilizing capillary force, degassed poly(dimethylsiloxane), pushbutton-driven pressure, a syringe, or a pipette have been reported. Among these methods, the pushbutton-driven, pressure-based method has a great potential to be widely used as a user-friendly sample preparation tool for point-of-care testing or portable diagnostics. In this Perspective, we focus on the pushbutton-activated microfluidic technologies toward a user-friendly sample preparation tool. The working principle and recent advances in pushbutton-activated microfluidic technologies are briefly reviewed, and future perspectives for wide application are discussed in terms of integration with the signal analysis system, user-dependent variation, and universal and facile use.     

A nanoporous optofluidic microsystem for highly sensitive and repeatable surface enhanced Raman spectroscopy detection

We report the demonstration of an optofluidic surface enhanced Raman spectroscopy (SERS) device that leverages a nanoporous microfluidic matrix to improve the SERS detection performance by more than two orders of magnitude as compared to a typical open microfluidic channel. Although it is a growing trend to integrate optical biosensors into microfluidic channels, this basic combination has been detrimental to the sensing performance when applied to SERS. Recently, however, synergistic combinations between microfluidic functions and photonics (i.e., optofluidics) have been implemented that improve the detection performance of SERS. Conceptually, the simplest optofluidic SERS techniques reported to date utilize a single nanofluidic channel to trap nanoparticle-analyte conjugates as a method of preconcentration before detection. In this work, we leverage this paradigm while improving upon the simplicity by forming a 3D nanofluidic network with packed nanoporous silica microspheres in a microfluidic channel; this creates a concentration matrix that traps silver nanoclusters and adsorbed analytes into the SERS detection volume. With this approach, we are able to achieve a detection limit of 400 attomoles of Rhodamine 6G after only 2 min of sample loading with high chip-to-chip repeatability. Due to the high number of fluidic paths in the nanoporous channel, this approach is less prone to clogging than single nanofluidic inlets, and the loading time is decreased compared to previous reports. In addition, fabrication of this microsystem is quite simple, as nanoscale fabrication is not necessary. Finally, integrated multimode fiber optic cables eliminate the need for optical alignment, and thus the device is relevant for portable and automated applications in the field, including point-of-sample and point-of-care detection. To illustrate a relevant field-based application, we demonstrate the detection of 12 ppb of the organophosphate malathion in water using the nanofluidic SERS microsystem.     

Electrochemiluminescence—Improving the performance of immunossays

Conclusion  The novel combination of an electrochemiluminescent label used in a magnetic microparticle-based immunoassay format defines a significantly improved level of immunodiagnostic performance. The main advantages of electrochemiluminescent immunoassays are high sensitivity, extended linearity of signal response together with speed of signal generation and measurement. These attributes in conjunction with fully automated random access analyser lead to superior level of user convenience and clinical application. Electrochmemiluminescence has been applied today to a wide range of analytes of biological interest including thyroid and fertility hormones, infectious desease, as well as various markers of cardiac, malignant and auto immune disease. However, the spectrum of applications is far from being exhausted. The capacity of this technology goes beyond current requirements for diagnostic laboratory tests.     

Integration of programmable microfluidics and on-chip fluorescence detection for biosensing applications

We describe the integration of an actively controlled programmable microfluidic sample processor with on-chip optical fluorescence detection to create a single, hybrid sensor system. An array of lifting gate microvalves (automaton) is fabricated with soft lithography, which is reconfigurably joined to a liquid-core, anti-resonant reflecting optical waveguide (ARROW) silicon chip fabricated with conventional microfabrication. In the automaton, various sample handling steps such as mixing, transporting, splitting, isolating, and storing are achieved rapidly and precisely to detect viral nucleic acid targets, while the optofluidic chip provides single particle detection sensitivity using integrated optics. Specifically, an assay for detection of viral nucleic acid targets is implemented. Labeled target nucleic acids are first captured and isolated on magnetic microbeads in the automaton, followed by optical detection of single beads on the ARROW chip. The combination of automated microfluidic sample preparation and highly sensitive optical detection opens possibilities for portable instruments for point-of-use analysis of minute, low concentration biological samples.     

Microfluidic platform for isolating nucleic acid targets using sequence specific hybridization

The separation of target nucleic acid sequences from biological samples has emerged as a significant process in today''s diagnostics and detection strategies. In addition to the possible clinical applications, the fundamental understanding of target and sequence specific hybridization on surface modified magnetic beads is of high value. In this paper, we describe a novel microfluidic platform that utilizes a mobile magnetic field in static microfluidic channels, where single stranded DNA (ssDNA) molecules are isolated via nucleic acid hybridization. We first established efficient isolation of biotinylated capture probe (BP) using streptavidin-coated magnetic beads. Subsequently, we investigated the hybridization of target ssDNA with BP bound to beads and explained these hybridization kinetics using a dual-species kinetic model. The number of hybridized target ssDNA molecules was determined to be about 6.5 times less than that of BP on the bead surface, due to steric hindrance effects. The hybridization of target ssDNA with non-complementary BP bound to bead was also examined, and non-specific hybridization was found to be insignificant. Finally, we demonstrated highly efficient capture and isolation of target ssDNA in the presence of non-target ssDNA, where as low as 1% target ssDNA can be detected from mixture. The microfluidic method described in this paper is significantly relevant and is broadly applicable, especially towards point-of-care biological diagnostic platforms that require binding and separation of known target biomolecules, such as RNA, ssDNA, or protein.     

Microfluidic sample preparation for respiratory virus detection: A review

Techniques used to prepare clinical samples have been perfected for use in diagnostic testing in a variety of clinical situations, e.g., to extract, concentrate, and purify respiratory virus particles. These techniques offer a high level of purity and concentration of target samples but require significant equipment and highly trained personnel to conduct, which is difficult to achieve in resource-limited environments where rapid testing and diagnostics are crucial for proper handling of respiratory viruses. Microfluidics has popularly been utilized toward rapid virus detection in resource-limited environments, where most devices focused on detection rather than sample preparation. Initial microfluidic prototypes have been hindered by their reliance on several off-chip preprocessing steps and external laboratory equipment. Recently, sample preparation methods have also been incorporated into microfluidics to conduct the virus detection in an all-in-one, automated manner. Extraction, concentration, and purification of viruses have been demonstrated in smaller volumes of samples and reagents, with no need for specialized training or complex machinery. Recent devices show the ability to function independently and efficiently to provide rapid, automated sample preparation as well as the detection of viral samples with high efficiency. In this review, methods of microfluidic sample preparation for the isolation and purification of viral samples are discussed, limitations of current systems are summarized, and potential advances are identified.     

Rapid microfluidic immunoassay for surveillance and diagnosis of Cryptosporidium infection in human immunodeficiency virus-infected patients

Cryptosporidiosis has been reported to be associated with HIV/acquired immune deficiency syndrome, which greatly reduces the quality of life and shortens the life expectancy of HIV-infected patients. In order to properly treat the infected patients, accurate and automatic diagnostic tools need to be developed. In this study, a novel microfluidic immunochip system was presented for the surveillance and the rapid detection of Cryptosporidium infection in 190 HIV-infected patients from Guangxi, China, using the P23 antigen of Cryptosporidium. The procedure of detection can be completed within 10 min with 2 μl sample consumption. The system also was evaluated using the standard ELISA method. Among 190 HIV-infected individuals, the rate of P23 positivity was 13.7%. Seropositivity in HIV-infected individuals was higher in female patients. The seropositivity to P23 was higher in HIV-infected individuals with high viral load, although the difference was statistically insignificant. Significantly higher Cryptosporidium seropositivity was observed in HIV-infected individuals with a CD4⁺ T-cell count of <200 cells/μl than in those with ≥200 cells/μl. Our results also demonstrate that a lower CD4⁺ T-cell count may reflect an increased accumulated risk for cryptosporidiosis. The detection system was further validated using the standard ELISA method and good correlation between the two methods was found (r = 0.80). Under the same sensitivity, this new microfluidic chip device had a specificity of 98.2%. This developed system may provide a powerful platform for the fast screening of Cryptospordium infection in HIV-infected patients.     

加强我国新发突发传染病中医药应急防控体系建设的战略思考

在全球新冠肺炎疫情肆虐之际,中国疫情防控取得重大战略成果。中国不仅及时控制了疫情的扩散,国内生产生活也已逐步恢复正常。在疫情阻击战的"中国答卷"中,中医药全面、全程参与疫情防控成为此次抗疫的亮点与特色。但面对新发突发传染病,中医药参与防控的储备和应急能力均存在不足,尤其是在中医药快速应急响应机制、应急救治制度、专业人才培养、应急科研体系与平台建设、应急战略资源储备等方面显得更为突出。加强我国新发突发传染病的中医药应急防控体系建设,不仅能提升我国重大突发公共卫生事件的应急防控能力,也是保障人民群众的人身安全与生命健康的必然需求。文章结合中医药在此次新冠肺炎疫情防治中的实践经验及历代抗疫智慧,分析其中亟待解决或完善的薄弱环节,就如何加强我国新发突发传染病中医药应急防控体系提出建议。     

多元协同视角下应急科研协同创新机制与动态评价——以重大疫情为例

针对重大疫情应急科研的紧迫性、重要性、时效性和协作性的特点,将协同主体、协同任务、协同要素、协同机制、协同绩效和支撑要素等多元协同维度纳入统一的分析框架和逻辑体系,构建多元协同的应急科研协同创新机制;然后将DEMATEL法和网络层次分析(ANP)法进行融合,建立基于DEMATEL-ANP模型的模糊综合评价模型,对重大疫情环境下的应急科研协同活动进行动态评价;并以新型冠状病毒(2019-nCoV)抗体检测试剂盒研发项目为实践案例,对其应急科研协同程度进行测度和评价。研究结果表明,基于DEMATEL-ANP模型的模糊综合评价模型科学有效,能够对重大疫情应急科研协同程度进行精准和动态评价。     

多元协同视角下应急科研协同的创新机制与动态评价——以重大疫情为例

针对重大传染病疫情应急科研的紧迫性、重要性、时效性和协作性的特点,将协同主体、协同任务、协同要素、协同机制、协同绩效和支撑要素等多元协同维度纳入统一的分析框架和逻辑体系,构建多元协同的应急科研协同创新机制;然后将DEMATEL法和网络层次分析(ANP)法进行融合,建立基于DEMATEL-ANP模型的模糊综合评价模型,对重大传染病疫情环境下的应急科研协同活动进行动态评价;并以新型冠状病毒（2019-nCoV）抗体检测试剂盒研发为实践案例,对其应急科研协同程度进行测度和评价。研究结果表明,基于DEMATEL-ANP模型的模糊综合评价模型科学有效,能够对重大传染病疫情应急科研协同程度进行精准和动态评价。     

Microfluidic enrichment of small proteins from complex biological mixture on nanoporous silica chip

The growing field of miniaturized diagnostics is hindered by a lack of pre-analysis treatments that are capable of processing small sample volumes for the detection of low concentration analytes in a high-throughput manner. This letter presents a novel, highly efficient method for the extraction of low-molecular weight (LMW) proteins from biological fluids, represented by a mixture of standard proteins, using integrated microfluidic systems. We bound a polydimethylsiloxane layer patterned with a microfluidic channel onto a well-defined nanoporous silica substrate. Using rapid, pressure-driven fractionation steps, this system utilizes the size-exclusion properties of the silica nanopores to remove high molecular weight proteins while simultaneously isolating and enriching LMW proteins present in the biological sample. The introduction of the microfluidic component offers important advantages such as high reproducibility, a simple user interface, controlled environment, the ability to process small sample volumes, and precise quantification. This solution streamlines high-throughput proteomics research on many fronts and may find broad acceptance and application in clinical diagnostics and point of care detection.     

Biosensors for immune cell analysis-A perspective

Massively parallel analysis of single immune cells or small immune cell colonies for disease detection, drug screening, and antibody production represents a "killer app" for the rapidly maturing microfabrication and microfluidic technologies. In our view, microfabricated solid-phase and flow cytometry platforms of the future will be complete with biosensors and electrical/mechanical/optical actuators and will enable multi-parametric analysis of cell function, real-time detection of secreted signals, and facile retrieval of cells deemed interesting.     

The mechanical properties of stored red blood cells measured by a convenient microfluidic approach combining with mathematic model

The mechanical properties of red blood cells (RBCs) are critical to the rheological and hemodynamic behavior of blood. Although measurements of the mechanical properties of RBCs have been studied for many years, the existing methods, such as ektacytometry, micropipette aspiration, and microfluidic approaches, still have limitations. Mechanical changes to RBCs during storage play an important role in transfusions, and so need to be evaluated pre-transfusion, which demands a convenient and rapid detection method. We present a microfluidic approach that focuses on the mechanical properties of single cell under physiological shear flow and does not require any high-end equipment, like a high-speed camera. Using this method, the images of stretched RBCs under physical shear can be obtained. The subsequent analysis, combined with mathematic models, gives the deformability distribution, the morphology distribution, the normalized curvature, and the Young''s modulus (E) of the stored RBCs. The deformability index and the morphology distribution show that the deformability of RBCs decreases significantly with storage time. The normalized curvature, which is defined as the curvature of the cell tail during stretching in flow, suggests that the surface charge of the stored RBCs decreases significantly. According to the mathematic model, which derives from the relation between shear stress and the adherent cells'' extension ratio, the Young''s moduli of the stored RBCs are also calculated and show significant increase with storage. Therefore, the present method is capable of representing the mechanical properties and can distinguish the mechanical changes of the RBCs during storage. The advantages of this method are the small sample needed, high-throughput, and easy-use, which make it promising for the quality monitoring of RBCs.     

Two dimensional barcode-inspired automatic analysis for arrayed microfluidic immunoassays

The usability of many high-throughput lab-on-a-chip devices in point-of-care applications is currently limited by the manual data acquisition and analysis process, which are labor intensive and time consuming. Based on our original design in the biochemical reactions, we proposed here a universal approach to perform automatic, fast, and robust analysis for high-throughput array-based microfluidic immunoassays. Inspired by two-dimensional (2D) barcodes, we incorporated asymmetric function patterns into a microfluidic array. These function patterns provide quantitative information on the characteristic dimensions of the microfluidic array, as well as mark its orientation and origin of coordinates. We used a computer program to perform automatic analysis for a high-throughput antigen/antibody interaction experiment in 10 s, which was more than 500 times faster than conventional manual processing. Our method is broadly applicable to many other microchannel-based immunoassays.     

Microfluidic model of monocyte extravasation reveals the role of hemodynamics and subendothelial matrix mechanics in regulating endothelial integrity

Extravasation of circulating cells is an essential process that governs tissue inflammation and the body''s response to pathogenic infection. To initiate anti-inflammatory and phagocytic functions within tissues, immune cells must cross the vascular endothelial barrier from the vessel lumen to the subluminal extracellular matrix. In this work, we present a microfluidic approach that enables the recreation of a three-dimensional, perfused endothelial vessel formed by human endothelial cells embedded within a collagen-rich matrix. Monocytes are introduced into the vessel perfusate, and we investigate the role of luminal flow and collagen concentration on extravasation. In vessels conditioned with the flow, increased monocyte adhesion to the vascular wall was observed, though fewer monocytes extravasated to the collagen hydrogel. Our results suggest that the lower rates of extravasation are due to the increased vessel integrity and reduced permeability of the endothelial monolayer. We further demonstrate that vascular permeability is a function of collagen hydrogel mass concentration, with increased collagen concentrations leading to elevated vascular permeability and increased extravasation. Collectively, our results demonstrate that extravasation of monocytes is highly regulated by the structural integrity of the endothelial monolayer. The microfluidic approach developed here allows for the dissection of the relative contributions of these cues to further understand the key governing processes that regulate circulating cell extravasation and inflammation.