Pathogenic Surveillance of Foodborne Illness-Related Diarrhea - Beijing Municipality, China, 2013-2023.

What is already known about this topic?: Foodborne diseases present a significant public health concern, particularly in China, where they represent a significant food safety challenge. Currently, there is a need for a thorough and systematic analysis of the extended epidemiological patterns of foodborne diseases in Beijing Municipality. What is added by this report?: Monitoring results show that Norovirus and diarrheagenic Escherichia coli (DEC) are the most commonly identified foodborne diarrheal pathogens. Individuals aged 19-30 are at a higher risk of foodborne diarrhea in Beijing, with Salmonella infection being associated with fever symptoms. What are the implications for public health practice?: This study analyzes 11 years of consecutive monitoring data to enhance understanding of the epidemiological and clinical features of foodborne diarrhea in Beijing. It aims to identify high-risk populations, assist in clinical pathogen identification and treatment, and support the development of tailored preventive strategies.

Rapid and sensitive electrochemiluminescence detection using easily fabricated sensor with an integrated two-electrode system.

The electrochemiluminescence (ECL) behavior of a tri(2,2'-bipyridyl)ruthenium(ii) (Ru(bpy)32+)/tripropylamine (TPrA) system was investigated in sensor chips with two kinds of integrated two-electrode systems, which included screen-printed electrodes (SPE) and physical vapor deposition (PVD) electrodes. Firstly, under excitation with an optimal transient potential (TP) within 100 ms, the ECL assay could be carried out on the microchips using an Au & Au electrode system, emitting strong and stable light signal. Secondly, on the PVD chip, the ECL intensity initiated by optimal TP was eight times stronger than the peak light signal emitted by the linear sweep voltammetry model. Finally, the logarithmic ECL intensities exhibited a linear increase with the logarithmic concentrations of Ru(bpy)32+ in both the SPE and PVD chips without any reference electrode (RE). Typically, the integration of an interdigital two-electrode system in the microchip significantly enhanced the ECL sensitivity of Ru(bpy)32+ because the large relative area between the working electrode (WE) and counter electrode (CE) achieved a highly efficient mass transfer. This improvement enabled the establishment of a reliable linear relationship across a wide concentration range, spanning from 1 pM to 1 µM (R2 = 0.998). Therefore, the exceptional ECL response of the Ru(bpy)32+/TPrA system on microfluidic chips using a two-electrode system and the TP excitation model has been demonstrated. This suggests that ECL chips without a RE have broad potential for the rapid and sensitive detection of multiple targets.

Faraday cage-type ECL biosensor for the detection of circulating tumor cell MCF-7.

Herein, a Faraday cage-type electrochemiluminescence biosensor was designed for the detection of human breast cancer cell MCF-7. Two kinds of nanomaterials, Fe3O4-APTs and GO@PTCA-APTs, were synthesized as capture unit and signal unit, respectively. In presence of the target MCF-7, the Faraday cage-type electrochemiluminescence biosensor was constructed by forming a complex "capture unit-MCF-7-signal unit". In this case, lots of electrochemiluminescence signal probes were assembled and could participate in the electrode reaction, achieving a significant increase in sensitivity. In addition, the double aptamer recognition strategy was adopted to improve the capture, enrichment efficiency and detection reliability. Under optimal experimental conditions, the limit of detection was 3 cells/mL. And, the sensor could afford the detection of actual human blood samples, which is the first report on the detection of intact circulating tumor cells by the Faraday cage-type electrochemiluminescence biosensor.

Prevalence and distribution of acute gastrointestinal illness in the community of China: a population-based face-to-face survey, 2014-2015.

BACKGROUND: The true incidence of acute gastrointestinal illness in China is underrecognized by surveillance systems. The aims of this study were to estimate the incidence and prevalence of self-reported AGI in the community of China, and to investigate sociodemographic and epidemiological determinants of AGI. METHODS: We conducted a 12-months cross-sectional population-based survey in eight provinces of China during 2014-2015. The survey determined the prevalence and incidence of acute gastrointestinal illness (AGI) in the total permanent resident population in China according to the census of the population in 2010. The random multilevel population sample was stratified by geographic, population, and socioeconomic status. We used a recommended case definition of AGI, with diarrhea (three loose or watery stools) and/or any vomiting in a four-week recall. A face-to-face survey was conducted by selecting the member in the household with the most recent birthday. RESULTS: Among 56,704 sampled individuals, 948 (1,134 person-time) fulfilled the case definition; 98.5% reported diarrhea. This corresponds to 2.3% (95% CI:1.9%-2.8%) of an overall standardized four-week prevalence and 0.3 (95% CI: 0.23-0.34) episodes per person-year of annual adjusted incidence rate. There was no significant difference between males and females. The incidence rates were higher among urban residents, and in the spring and summer. In the whole study period, 50% of the cases sought medical care, of which 3.9% were hospitalized and 14.3% provided a biological sample for laboratory identification of the causative agent. Children aged 0-4 and young adults aged 15-24, people living in rural areas and people who traveled frequently had higher prevalence of AGI. CONCLUSION: Results showed that AGI represents a substantial burden in China, and will contribute to the estimation of the global burden of AGI. Complemented with data on the etiologies of AGI, these estimates will form the basis to estimate the burden of foodborne diseases in China.

Electrochemical sensor for single-cell determination of bacteria based on target-triggered click chemistry and fast scan voltammetry.

Herein, an electrochemical sensor for single-cell determination of bacteria was developed based on target-triggered click chemistry and fast scan voltammetry (FSV). In it, bacteria not only are the detection target, but also can use their own metabolism to achieve first-level signal amplification. More electrochemical labels were immobilized on functionalized 2D nanomaterials to achieve second-level signal amplification. At 400 V/s, FSV can achieve third-level signal amplification. The linear range and limit of quantification (LOQ) are 1 âˆ¼ 108 CFU/mL and 1 CFU/mL, respectively. When the reaction time of E. coli-instructed Cu2+ reduction is extended to 120 min, PCR-free single-cell determination of E. coli was achieved by electrochemical method first time. The feasibility of the sensor was verified by analysis of E. coli in seawater and milk samples with recoveries ranging from 94% to 110%. This detection principle is widely applicable, providing a new path for the establishment of single-cell detection strategy for bacteria.

Cluster-bomb type magnetic biosensor for ultrasensitive detection of Vibrio parahaemolyticus based on low field nuclear magnetic resonance.

Herein, a novel cluster-bomb type signal sensing and amplification strategy in low field nuclear magnetic resonance was proposed, and a magnetic biosensor for ultrasensitive homogeneous immunoassay of Vibrio parahaemolyticus (VP) was developed. The capture unit MGO@Ab was magnetic graphene oxide (MGO) immobilized by VP antibody (Ab) to capture VP. And, the signal unit PS@Gd-CQDs@Ab was polystyrene (PS) pellets covered by Ab to recognize VP and Gd-CQDs i.e. carbon quantum dots (CQDs) containing lots of magnetic signal labels Gd3+. In presence of VP, the immunocomplex signal unit-VP-capture unit could be formed and separated by magnetic force conveniently from the sample matrix. With the successive introduction of disulfide threitol and hydrochloric acid, signal units were cleaved and disintegrated, resulting in a homogeneous dispersion of Gd3+. Thus, cluster-bomb type dual signal amplification was achieved through increasing the amount and the dispersity of signal labels simultaneously. Under optimal experimental conditions, VP could be detected in the concentration range of 5-1.0 × 106 CFU/mL, with a limit of quantitation (LOQ) 4 CFU/mL. In addition, satisfactory selectivity, stability and reliability could be obtained. Therefore, this cluster-bomb type signal sensing and amplification strategy is powerful in designing magnetic biosensor and detecting pathogenic bacteria.

Low-cost portable bioluminescence detector based on silicon photomultiplier for on-site colony detection.

A low-cost, portable bioluminescence detector based on a silicon photomultiplier (SiPM) was developed for on-site colony detection, the main components of which are a low-noise photoelectric signal detection and processing circuit, power management module, and high-performance embedded microcontroller subsystem with peripheral circuits. Balanced chopper modulation and lock-in amplification techniques were adopted to improve the signal-to-noise ratio, and a zero-adjustment technique was used to eliminate the dark current of the SiPM to expand the dynamic range. Using this bioluminescence detector, adenosine triphosphate could be determined in the range of 3.6 × 10-6 to 3.6 × 10-11 mol/L, and bacterial colonies could be determined in the range of 1.0 × 103 to 1.0 × 109 CFU/mL, with a limit of quantitation of 1.0 × 103 CFU/mL. Satisfactory recoveries and precision were obtained. Actual samples were accurately tested and the data were verified by comparison with those from the national standard method. The manufacturing cost of the bioluminescence detector was only $30, which is only approximately 1% of the price of current commercial instruments. This study provides a tool for rapid on-site detection of bacterial colonies, as well as a new concept for the development of low-cost portable detection equipment.

A CRISPR/Cas12a-Mediated Dual-Mode Electrochemical Biosensor for Polymerase Chain Reaction-Free Detection of Genetically Modified Soybean.

A clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a-mediated dual-mode electrochemical biosensor without polymerase chain reaction (PCR) amplification was designed for sensitive and reliable detection of genetically modified soybean SHZD32-1. A functionalized composite bionanomaterial Fe3O4@AuNPs/DNA-Fc&Ru was synthesized as the signal unit, while a characteristic gene fragment of SHZD32-1 was chosen as the target DNA (tDNA). When Cas12a, crRNA, and tDNA were present simultaneously, a ternary complex Cas12a-crRNA-tDNA was formed, and the nonspecific cleavage ability of the CRISPR/Cas12a system toward single-stranded DNA was activated. Thus, the single-stranded DNA-Fc in the signal unit was cleaved, resulting in the decrease in the fast scan voltammetric (FSV) signal from ferrocene (Fc) and the increase in the electrochemiluminescence (ECL) signal from ruthenium complex (Ru) inhibited by Fc. The linear range was 1-107 fmol/L for ECL and 10-108 fmol/L for FSV, and the limit of detection (LOD) was 0.3 fmol/L for ECL and 3 fmol/L for FSV. Accuracy, precision, stability, selectivity, and reliability were all satisfied. In addition, PCR-free detection could be completed in an hour at room temperature without requiring complicated operation and sample processing, showing great potential in the field detection of genetically modified crops.

A fast scan cyclic voltammetric digital circuit with precise ohmic drop compensation by online measuring solution resistance and its biosensing application.

In this work, a novel fast scan digital circuit for voltammetric analysis with precious ohmic drop compensation is developed, which is achieved through online measuring solution resistance first and then proportionally feedbacking the output signal to potentiostat's in-phase input through a potentiometer. It mainly consists of a solution resistance measurement module based on AD5933 chip, an ohmic drop automatic compensation module and a STM32F103ZET6 microcontroller. The performance of the circuit is checked successively using pure resistances, RC dummy cells, RC dummy cells incorporating a pseudo-faradaic component, and the ferrocene redox system. Results show that, precise ohmic drop compensation can be realized online and automatically, affording fast scan cyclic voltammetric (FSCV) analysis for theoretical electrochemical cells at 2000 V/s and that for practical electrochemical system using conventional electrodes at 1600 V/s. Based on this circuit, a very simple DNA biosensor for ultrasensitive detection of mercuric ions was explored. Benefitting from the high sensitivity brought by the high scan rate, the limit of quantitation (LOQ) can reach 1 pmol/L, demonstrating the application potential of FSCV in the field of ultrasensitive electrochemical detection.

Suspended germanium waveguides with subwavelength-grating metamaterial cladding for the mid-infrared band.

In recent years, sensing and communication applications have fueled important developments of group-IV photonics in the mid-infrared band. In the long-wave range, most platforms are based on germanium, which is transparent up to ∼15-µm wavelength. However, those platforms are limited by the intrinsic losses of complementary materials or require complex fabrication processes. To overcome these limitations, we propose suspended germanium waveguides with a subwavelength metamaterial lateral cladding that simultaneously provides optical confinement and allows structural suspension. These all-germanium waveguides can be fabricated in one dry and one wet etch step. A propagation loss of 5.3 dB/cm is measured at a wavelength of 7.7 µm. These results open the door for the development of integrated devices that can be fabricated in a simple manner and can potentially cover the mid-infrared band up to ∼15 µm.

Management of Locally Excited States for Purine-based TADF Emitters: A Method to Reduce Device Efficiency Roll-Off.

The programmed arylation of purine has been developed to construct a series of efficient thermally activated delayed fluorescent (TADF) materials. The corresponding organic light-emitting diodes (OLEDs) exhibit external quantum efficiency as high as 16.0% alongside small efficiency roll-off. Intriguingly, this work proves that the good management of localized states is an efficient way to reduce device efficiency roll-off and is crucial for the future design of high-performance OLEDs.

Nanometallic antenna-assisted amorphous silicon waveguide integrated bolometer for mid-infrared.

Bolometers are thermal detectors widely applied in the mid-infrared (MIR) wavelength range. In an integrated sensing system on chip, a broadband scalable bolometer absorbing the light over the whole MIR wavelength range could play an important role. In this work, we have developed a waveguide-based bolometer operating in the wavelength range of 3.72-3.88 µm on the amorphous silicon (a-Si) platform. Significant improvements in the bolometer design result in a 20× improved responsivity compared to earlier work on silicon-on-insulator (SOI). The bolometer offers 24.62% change in resistance per milliwatt of input power at 3.8 µm wavelength. The thermal conductance of the bolometer is 3.86×10-5W/K, and an improvement as large as 3 orders magnitude may be possible in the future through redesign of the device geometry.

One-step electrochemical sensor based on an integrated probe toward sub-ppt level Pb2+ detection by fast scan voltammetry.

Herein, a one-step electrochemical sensor for selective and sensitive detection of lead ion Pb2+ was developed based on an integrated probe meso-tetra(4-carboxyphenyl) porphine (TCPP)-multi-walled carbon nanotubes (MWCNTs)@Fe3O4, which is TCPP-modified magnetic multi-walled carbon nanotubes. In the integrated probe, TCPP is a porphyrin with a specific cavity structure which could selectively chelate with Pb2+, MWCNTs with good electric conductivity provide a place to load TCPP and form a specific adsorption state of Pb2+ on the electrode surface, and Fe3O4 enables the rapid separation and one-step fabrication of the electrochemical sensor. Based on it, the sample pre-enrichment, separation and determination can be integrated, making the whole process very fast and simple. In addition, fast scan voltammetry (FSV) with a scan rate up to 200 V/s could be used to improve the detection sensitivity greatly, benefitting from the specific adsorption state formed. Under the optimal conditions obtained through orthogonal experiments including adsorption time, integrated probe dosage and solution pH, there was a good linear relationship between the peak current and Pb2+ concentration ranging from 2.0 × 10-4 µg L-1 to 2.0 × 10-3 µg L-1, with the limit of detection (LOD) being 6.7 × 10-5 µg L-1 (S/N = 3) i.e. 0.067 ppt. Analysis of actual water samples was successful. Therefore, being simple, fast, selective and sensitive, the one-step electrochemical sensor proposed has a good potential in practical applications.

Fast scan voltammetry-derived ultrasensitive Faraday cage-type electrochemical immunoassay for large-size targets.

Electrochemical immunoassay (ECIA) is an important method for rapid, on-site detection of various analytes. However, its detection sensitivity is greatly limited by the traditional sandwich-type sensor construction mode, especially in the case of large-size targets such as pathogenic bacteria with micron size. Herein, we developed a Faraday cage-type sensing mode to build an electrochemical immunosensor based on a functionalized two-dimensional conductive nanomaterial, which could provide a platform to assemble a large number of electrochemical signal labels and a good support for the expansion of electrode surface. Electrons could flow between the electrode and the conductive nanomaterial and then exchange with all signal labels immobilized without the hindrance of non-conductive large-size targets, resulting in a significant signal amplification. In addition, first time integration with fast scan anodic stripping voltammetry (FSASV) allowed for further enhanced ECIA signal. Benefitting from both the Faraday cage-type sensing mode and the high scan rate 100 V s-1 of FSASV, electrochemical signal was effectively amplified several hundred times with a limit of quantitation (LOQ) of 1 CFU mL-1 for micron-sized pathogenic bacteria Vibrio parahemolyticus (VP). This work sheds lights on advancing the design of next-generation ECIA or other redox-related immunoassays with ultrahigh sensitivity, especially for large-size targets.

[Preliminary estimating the burden of foodborne acute gastrointestinal illness in Beijing City].

OBJECTIVE: To estimate the burden of foodborne acute gastrointestinal illness(AGI) in community residents, and to provide the basis for prevention and control of foodborne diseases. METHODS: Muli-stage stratified random cluster sampling was used to select samples in community population. A retrospective cross-sectional face-to-face household interviews were conducted over a 12-month period. Respondents were asked questions about vomiting and diarrhea within the 28 days prior to the interviews, healthcare seeking behavior and the related cost due to AGI. RESULTS: There were 0. 15(95%CI 0. 13-0. 16)AGI episodes per person-year, foodboren infection resulted in 911975 AGI cases. About 290 190 cases sought healthcare, resulting in 9120 hospitallizations. The overall economic burden of foodborne AGI was 147 million Yuan per year, accounting for 0. 07᾿of the GDP. The direct cost of medical care was 107 million Yuan(medical costs and non-medical cost were 9. 4 million and 1. 2 million), and the direct cost was 4 million Yuan. CONCLUSION: The burden of foodborne AGI in Beijing should not be ignored. It is necessary to improve the foodborne disease surveillance system to more accurately assess the impact of foodborne disease on society and health.

Silicon ring resonator-coupled Mach-Zehnder interferometers for the Fano resonance in the mid-IR.

We present ring resonator (RR)-coupled Mach-Zehnder interferometers (MZIs) based on silicon-on-insulator rib waveguides, operating around the mid-IR wavelength of 3.8 µm. A number of different photonic integrated devices have been designed and fabricated experimentally to obtain the asymmetric Fano resonances in the mid-IR. We have investigated the influence of the coupling efficiency between the RR and the MZI as well as the phase shift between the two arms of the MZI on the Fano-type resonance spectral features, in agreement with theoretical predictions. Finally, wavelength-dependent Fano transmittances have been successfully measured with insertion losses up to ∼1 dB and extinction ratios of ∼20 dB. A slope of sharp Fano resonances as high as -574.6/µm has been achieved and estimated to be 35.5% higher than the slope of single RR Lorentzian-type resonances.