A dual-RPA based lateral flow strip for sensitive,on-site detection of CP4-EPSPS and Cry1Ab/Ac genes in genetically modified crops

Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.

Cheesy material on macroscopic on-site evaluation after endoscopic ultrasound-guided fine-needle biopsy:Don't miss the tuberculosis

Endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)is an excellent investigation to diagnose pancreatic lesions and has shown high accuracy for its use in pathologic diagnosis.Recently,macroscopic on-site evaluation(MOSE)performed by an endoscopist was introduced as an alternative to rapid on-site cytologic evaluation to increase the diagnostic yield of EUS-FNB.The MOSE of the biopsy can estimate the adequacy of the sample directly by the macroscopic evaluation of the core tissue obtained from EUS-FNB.Isolated pancreatic tuberculosis is extremely rare and difficult to diagnose because of its non-specific signs and symptoms.Therefore,this challenging diagnosis is based on endoscopy,imaging,and the bacteriological and histological examination of tissue biopsies.This uncommon presentation of tuberculosis can be revealed as pancreatic mass mimicking cancer.EUS-FNB can be very useful in providing a valuable histopathological diagnosis.A calcified lesion with a cheesy core in MOSE must be suggestive of tuberculosis,leading to the request of the GeneXpert,which can detect Mycobacterium tuberculosis deoxyribonucleic acid and resistance to rifampicin.A decent diagnostic strategy is crucial to prevent unnecessary surgical resection and to supply conservative management with antitubercular therapy.

Improved edge lightweight YOLOv4 and its application in on-site power system work

A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithms for on-site risk assessment and alert.Owing to its lightweight and fast speed,YOLOv4-Tiny is often deployed on edge computing equipment for real-time video stream detection;however,its accuracy is relatively low.This study proposes an improved YOLOv4-Tiny algorithm based on attention mechanism and optimized training methods,achieving higher accuracy without compromising the speed.Specifically,a convolution block attention module branch is added to the backbone network to enhance the feature extraction capability and an efficient channel attention mechanism is added in the neck network to improve feature utilization.Moreover,three optimized training methods:transfer learning,mosaic data augmentation,and label smoothing are used to improve the training effect of this improved algorithm.Finally,an edge computing equipment experimental platform equipped with an NVIDIA Jetson Xavier NX chip is established and the newly developed algorithm is tested on it.According to the results,the speed of the improved YOLOv4-Tiny algorithm in detecting on-site dress code compliance datasets is 17.25 FPS,and the mean average precision(mAP)is increased from 70.89%to 85.03%.

Random Forests Algorithm Based Duplicate Detection in On-Site Programming Big Data Environment

On-site programming big data refers to the massive data generated in the process of software development with the characteristics of real-time,complexity and high-difficulty for processing.Therefore,data cleaning is essential for on-site programming big data.Duplicate data detection is an important step in data cleaning,which can save storage resources and enhance data consistency.Due to the insufficiency in traditional Sorted Neighborhood Method(SNM)and the difficulty of high-dimensional data detection,an optimized algorithm based on random forests with the dynamic and adaptive window size is proposed.The efficiency of the algorithm can be elevated by improving the method of the key-selection,reducing dimension of data set and using an adaptive variable size sliding window.Experimental results show that the improved SNM algorithm exhibits better performance and achieve higher accuracy.

Dynamical energy equipartition of the Toda model with additional on-site potentials

We study the dynamical energy equipartition properties in the integrable Toda model with additional uniform or disordered on-site energies by extensive numerical simulations. The total energy is initially equidistributed among some of the lowest frequency linear modes. For the Toda model with uniform on-site potentials, the energy spectrum keeps its profile nearly unchanged in a relatively short time scale. On a much longer time scale, the energies of tail modes increase slowly with time. Energy equipartition is far away from being attached in our studied time scale. For the Toda model with disordered on-site potentials, the energy transfers continuously to the high frequency modes and eventually towards energy equipartition. We further perform a systematic study of the equipartition time teq depending on the energy density ε and the nonlinear parameter α in the thermodynamic limit for the Toda model with disordered on-site potentials. We find teq∝ （1/ε）^a（1/α）^b, where b≈ 2a. The values of a and b are increased when increasing the strengths of disordered on-site potentials or decreasing the number of initially excited modes.

New Explorations of Laboratory and On-site Testing of Broadband Seismographs in China

According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's key parameters and other concerning technical specifications are well described in guide documents(China Earthquake Administration, 2017). This includes seismometer sensitivity, linearity and clip levels based on the shake table test, as well as the seismometer natural period, damping constant based on electrical calibration(Wang Guangfu,1986; Ple?inger A.,1993) and instrumental self-noise collocation estimation(Holcomb L.G., 1989; Sleeman R. et al., 2006). However, with the development of seismic observation technology, many new requirements for the performance evaluation of seismographs have been put forward, and new testing items and methods have emerged.

Increased Effluent Dosage Effects on On-Site Wastewater Treatment Systems of Differing Architecture Type

Approximately 20% of homes nationwide use an on-site treatment system as a form of household wastewater management. However, approximately 10% to 20% of on-site treatment systems malfunction each year, many of which have either failed or exceeded the soil’s long-term acceptance rate (LTAR), causing environmental and human health risks. The objective of this field study was to evaluate the effects of soil condition (e.g., wet and dry) and product architecture type [i.e., chamber, gravel-less-pipe (GLP), polystyrene-aggregate, and pipe-and-aggregate] on in-product solution storage and biomat thickness in a profile-limited soil in northwest Arkansas under increased loading rates and to estimate the LTAR for each product. During Phase I of this study (March 13 to October 4, 2013), effluent loading rates were approximately doubled, while rates were approximately quadrupled during Phase II (October 8, 2013 to May 29, 2014), from the maximum allowable loading rate for each product. The pipe-and-tire-chip, 46-cm-wide trench pipe-and-gravel, and the 25-cm diameter GLP products had the greatest (p < 0.001), while the 31-cm-width and the 5.4-m-long chambers had the lowest (p < 0.001) in-product solution storage during wet-soil conditions of Phase I monitoring. The 25-cm diameter GLP product had the greatest (p < 0.001), while the 61-cm-width, 5.4-m-long chamber had the lowest (p < 0.001) in-product solution storage during Phase II. Results of this study indicate that some alternative products may be able to effectively handle effluent loading rates in excess of those currently allowed by the State of Arkansas. Further research will be required to confirm these interpretations.

On-Site Calibration Method of Dosimeter Based on X-Ray Source

The real-time monitoring of environmental radiation dose for nuclear fa-cilities is an important part of safety, in order to guarantee the accuracy of the monitoring results regular calibration is necessary. Around nuclear facilities there are so many environmental dosimeters installed dispers-edly, because of its huge quantity, widely distributed, and in real-time monitoring state;it will cost lots of manpower and finance if it were tak-en to calibrate on standard laboratory;what’s more it will make the en-vironment out of control. To solve the problem of the measurement ac-curacy of the stationary gamma radiation dosimeter, an on-site calibra-tion method is proposed. The radioactive source is X-ray spectrum, and the dose reference instrument which has been calibrated by the national standard laboratory is a high pressure ionization. On-site calibration is divided into two parts;firstly the energy response experiment of dosim-eter for high and low energy is done in the laboratory, and the energy response curve is obtained combining with Monte Carlo simulation;sec-ondly experiment is carried out in the field of the measuring dosimeter, and the substitution method to calibrate the dosimeter is used;finally the calibration coefficient is gotten through energy curve correction. In order to verify the accuracy of on-site calibration method, the calibrated dosimeter is test in the standard laboratory and the error is 3.4%. The re-sult shows that the on-site calibration method using X-ray is feasible, and it can improves the accuracy of the measurement results of the stationary &gamma;-ray instrument;what’s more important is that it has great reference value for the radiation safety management and radiation environment evaluation.

Simulation of fire emergency evacuation in a large-passenger-flow subway station based on the on-site measured data of Shenzhen Metro

Because of its large capacity,high efficiency and energy savings,the subway has gradually become the primary mode of transportation for citizens.A high density of passengers exists within a large-passenger-flow subway station,and the number of casualties and injuries during a fire emergency is substantial.In this paper,Pathfinder software and on-site measured data of Pingzhou station in Shenzhen(China)were utilized to simulate a fire emergency evacuation in a large-passenger-flow subway station.The Required Safe Egress Time(RSET),number of passengers and flow rates of stairs and escalators were analysed for three fire evacuation scenarios:train fire,platform fire and hall fire.The evacuation time of the train fire,which was 1173 s,was the longest,and 3621 occupants needed to evacuate when the train was fully loaded.Occupants could not complete the evacuation within 6 mins in all three fire evacuation scenarios,which does not meet the current standard requirements and codes.By changing the number of passengers and the number of stairs for evacuation,the flow rate capacity and evacuation time were explored,which have reference values for safety management and emergency evacuation plan optimization during peak hours of subway operation.

A critical review of on-site inorganic arsenic screening methods

Approximately 94 to 220 million people worldwide are at risk of drinking well water containing arsenic > 10 μg/L, the WHO guideline value. To identify non-compliant domestic wells, assess health risks and reduce exposure, accurate and rapid on-site inorganic arsenic screening methods are desirable because all domestic wells worldwide need to be tested.Here, the principles, advantages and limitations of commonly used colorimetry, electrochemistry, and biosensing methods are critically reviewed, with the performance compared with laboratory-based benchmark methods. Most commercial kits are based on the classic Gutzeit reaction. Despite being semi-quantitative, the more recent and more expensive products display improved and acceptable accuracy and shorter testing time (~10 min). Carried out by trained professionals, electrochemical methods are also feasible for on-site analysis, although miniaturization is desirable yet challenging. Biosensing using whole bacterial cells or bio-engineered materials such as aptamers is promising, if incorporated with function specific nanomaterials and biomaterials. Since arsenic is frequently found as arsenite in reducing groundwater and subject to oxidation during sampling, transportation and storage, on-site separation and sample preservation are feasible but the specific methods should be chosen based on sample matrix and tested before use. To eliminate arsenic exposure among hundreds of millions of mostly rural residents worldwide, we call for concerted efforts in research community and regulatory authority to develop accurate, rapid, and affordable tests for on-site screening and monitoring of arsenic in drinking water. Access to affordable testing will benefit people who are socioeconomically disadvantaged.

A positively charged silver nanowire membrane for rapid on-site swabbing extraction and detection of trace inorganic explosives using a portable Raman spectrometer

The sensitive and on-site detection of inorganic explosives has raised serious concerns regarding public safety. However, high stability and non-volatility features currently limit their rapid on-site detection. Surface-enhanced Raman spectroscopy （SERS） is emerging as a powerful technique for the trace-level detection of different molecules. Plasmonic Ag nanowires were produced by a hydrothermal synthesis method using polyvinylpyrrolidone （PVP） as a negatively charged stabilizer. Here, we report a rapid detection method for inorganic explosives based on a simple surface swab with a positively charged diethyldithiocarbamate-modified Ag nanowire membrane coupled with SERS. This membrane, serving as an excellent SERS substrate with high uniformity, stability, and reusability, can capture both typical oxidizers in inorganic explosives and organic nitro-explosives, via electrostatic interaction. The detection level of perchlorates （ClO4-）, chlorates （ClO3-）, nitrates （NO3）-, picric acid, and 2,4- dinitrophenol is as high as 2.0, 1.7, 0.1, 45.8, and 36.6 ng, respectively. In addition, simulated typical inorganic explosives such as black powders, firecrackers, and match heads could also be detected. We believe that this membrane represents an attractive alternative for rapid on-site detection of inorganic explosives with high efficiency.

Novel method for improving iron recovery from electric arc furnace slag: on-site hot modification

The iron element in electric arc furnace(EAF)slag is extremely difficult to recycle due to the low specific magnetic susceptibility of the RO phase(a solid solution of FeO,MgO,CaO,and MnO).Landfilling EAF slag is strictly forbidden for environmental consideration because of poisonous Cr^(6+) leaching.The original RO phase could be transformed to a spinel structure,whose specific magnetic susceptibility is much higher than that of other minerals,through hot modification,resulting in significantly increased iron recovery by magnetic separation.Precipitation of spinel crystals encloses chromium,such that iron and chromium could be recovered simultaneously.The chromium in obtained iron concentrates is considerably useful for stainless steel making rather than polluting the environment.As a result,recovering iron and chromium is truly beneficial for cleaner production.Hot modification of EAF slag should be conducted at 1500-1600ºC for at least 60 min to guarantee homogeneous liquid slag.The liquid slag was poured onto an iron mold to obtain modified slag(MS)through air quenching.MS was characterized by thermodynamic analysis,X-ray diffraction,and scanning electron microscopy combined with energy-dispersive spectroscopy to correlate the relationship between mineral structures and iron recovery.The iron recovery rate of MS first increased and then decreased with increasing modifier.It was less than 10%when the modifier addition amount was below 12 wt.%,but it increased rapidly as the modifier addition amount increased from 16 to 24 wt.%,mainly due to spinel formation.The highest iron recovery rate was 81.9%when the modifier amount reached 20 wt.%.Meanwhile,Cr^(6+) was enriched in the spinel phase but was not observed in other minerals.Industrial tests were performed on-site with the modifier ranging from 12 to 18 wt.%because additional heat was not provided during the tests.Results showed that MS with 18 wt.%modifier addition exhibited an iron recovery rate of 61.0%,much higher than that(34.6%)of the original slag.

Performance evaluation on the pollution control against wet weather overflow based on on-site coagulation/flocculation in terminal drainage pipes

The pollution caused by wet weather overflow in urban drainage systems is a main factor causing blackening an odorization of urban rivers.The conventional overflow treatment based on coagulation/flocculation in terminal drainage systems requires relatively large space and long retention time demand that makes it not applicable in crowded urban drainage systems or under heavy rains.On-site coagulation/flocculation in terminal drainage pipes was proposed in this study which was aimed to transfer the coagulation/flocculation process to the inside of pipes at the terminal drainage system to save space and reduce the retention time of the coagulation/flocculation process.The optimized dose of chemicals was studied first which was 80 mg/L of coagulant and 0.8 mg/L of flocculant.Settling for only 5 min can remove most of the pollutants at 406.5 m of transmission distance.In addition,the relation of wet weather overflow rate and concentration of pollution load on the on-site coagulation/flocculation process was investigated,which indicated that high removal of pollutant was gained at a large range of flow velocity and pollutant concentration.Finally,the study confirmed electric neutralization,bridging,and net capture as the major mechanisms in this process,and further optimization was proposed.The proposed process can reduce much turbidity,chemical oxygen demand,and total phosphorous,but hardly remove soluble ammonia and organics.This work provides scientific guidance to address wet weather overflow in terminal drainage pipes.

Rapid dissociation and on-site saturation evaluation of methane hydrate sediment samples for natural gas hydrate exploitation

Natural gas hydrate is a kind of clean energy with huge reserves,and the saturation(volume percentage of hydrate in pore space of sediments)is the key parameter for determining whether the reservoir is worthy of exploitation.In this work,rapid hydrate dissociation by the combination of heat injection and NaCl inhibitor addition was studied,and an on-site evaluation method for hydrate saturation in sediment samples was proposed by using a core sampler to transfer hydrate samples under pressure.The results showed that the average gas production rate per unit volume was increased significantly to reach 7.22 L/Lr$min-1 by the injection of NaCl aqueous solution with 50.9C,which was attributed to the increase of the chemical potential to further accelerate the rate of hydrate dissociation in the presence of NaCl.Furthermore,for the measurement of methane hydrate samples saturation with a volume of 673 cm3(which contained 1.4 mol hydrates with the saturation of 58%),hydrate saturation could be accurately achieved within 30 min with a relative error lower than 11.7%This work may provide new thoughts for on-site saturation evaluation and rapid dissociation of hydrate samples during natural gas hydrate exploitation.

Cost-effective method for degradability identification of MSW using convolutional neural network for on-site composting

Automatically identifying the degradability of municipal solid waste(MSW)is one of the key prerequisites for on-site composting to prevent contaminations from undegradable wastes.In this study,a cost-effective method was proposed for the degradability identification of MSW.Firstly,the trainable images in the datasets were increased by performing four different sizes of cropping operations on the original images captured on-site.Secondly,a lite convolutional neural network(CNN)model was built with only 3.37 million parameters,and then a total of eight models were trained on these datasets with and without the image augmentation operations,respectively.Finally,a degradability identification system was built for on-site composting,where the images were cut to different sizes of small squares for prediction,and the experiments were conducted to find the best combinations of the trained models and the cutting size.The results showed that the validation accuracies of the models trained with the augmentation operations were 0.91-2.07 percentage points higher,and in the evaluation of the degradability identification system the best result was achieved by the combination of W8A dataset and cutting size of 1/14 reached an accuracy of 91.58%,which indicated the capability of this cost-effective method to identify the degradability of MSW.

The On-site Verification of Key Technologies for Kunbei-Liuzhou-Longmen Hybrid Multi-terminal Ultra HVDC Project

Hybrid high voltage direct current transmission(Hybrid HVDC)is a new type of HVDC technology developed in recent years.It combines the characteristics of large-capacity and low cost of the line commutated converters(LCC)and non-commutation failure and dynamic reactive power support of voltage sourced converters(VSCs)in one HVDC system.It has technical advantages in the fields of unidirectional power transmission and in the application of improving the stability of multi-infeed HVDCs,giving it broad application prospects.The Kunbei-Liuzhou-Longmen(KBL)project is the first hybrid ultra HVDC project.It was put into service on Dec.27th,2020.This paper introduces the KBL project,analyzes the operation characteristics of hybrid HVDC system,and provides on-site verification of KBL project,including operation of LCC-VSC hybrid system,ultra-high voltage VSC technology using the series of two valve groups,the DC fault ride-though of hybrid VSC without using DC breaker,the connection and disconnection of a third station,and etc.

On-site identification of Ophiocordyceps sinensis using multispectral imaging and chemometrics

For the reasonable and effective collection of Ophiocordyceps sinensis,a new method of on-site identification was attempted using a portable multispectral imaging(MSI)technique.Three dimensional(3D)data-cubes of representative Ophiocordyceps sinensis and weeds samples were acquired and pre-processed with standard normal variate transformation(SNV).Principal component analysis(PCA)and simulated annealing particle swarm optimisation(SAPSO)algorithms were used to extract characteristic images and develop the support vector classification(SVC)models.Results show that the fused feature model of SAPSO-SVC has the best performance,resulting in a recognition accuracy of the prediction set of 96.30%.Moreover,on-site distribution map of Ophiocordyceps sinensis and weeds was created using the spectral feature model of SAPSO-SVC,and the target could be easily identified from the distribution map.This work demonstrates the potential for on-site identification of Ophiocordyceps sinensis in the Qinghai-Tibet Plateau using a portable MSI technique combined with the SAPSO-SVC algorithm.

Rapid method for on-site determination of phenolic contaminants in water using a disposable biosensor

A disposable biosensor was fabricated using single-walled carbon nanotubes, gold nanoparticles and tyrosinase （SWCNTs-AuNPs-Tyr） modified screen-printed electrodes. The prepared biosensor was applied to the rapid determination of phenolic contaminants within 15 minutes. The SWCNTs-AuNPs-Tyr bionanocomposite sensing layer was characterized with scanning electron micro- scopy, electrochemical impedance spectroscopy and cyclic voltammetry methods. The characterization results revealed that SWCNTs could lead to a high loading of tyrosinase （Tyr） with the large surface area and the porous morphology, while AuNPs could retain the bioactivity of Tyr and enhance the sensitivity. The detection conditions, including working potential, pH of supporting electrolyte and the amount of Tyr were optimumed. As an example, the biosensor for catechol determination displayed a linear range of 8.0 × 10^-8 to 2.0 × 10^- 5 mol.L-1 with a detection limit of 4.5 × 10^-8 mol.L-1 （S/N= 3）. This method has a rapid response time within 10 s, and shows excellent repeatability and stability. Moreover, the resulting biosen- sor could be disposable, low-cost, reliable and easy to carry. This kind of new Tyr biosensor provides great potential for rapid, on-site and cost-effective analysis of phenolic contaminants in environmental water samples.

Mobile augmented reality visualization and collaboration techniques for on-site finite element structural analysis

In this paper,a mobile augmented reality(AR)framework for on-site finite element analysis(FEA)is proposed.The proposed framework is achieved using a client–server architecture.The performance of FEA relies on several important components,namely,computational power,visualization technique,and numerical analysis.AR renders intuitive computer-generated contents directly on a user’s surroundings.Integrating FEA with AR helps users through enhancing their perception and interaction with the engineering problems.Correct and effective visualization of these data using an AR platform can reduce the misinterpretation in spatial and logical aspects.Over the past decade,AR has undergone a transition from desktop to phablet computing.Mobile platforms enable user exploration of FEA results in situ.The client side uses a hybrid method to visualize FEA results in the mobile AR environment.In addition,a user can collaborate with other users by using the result sharing function.A prototype with basic functions has been built and a case study has been implemented to demonstrate the visualization method and evaluate the overall performance.

Development of RPA-Cas12a-fluorescence assay for rapid and reliable detection of human bocavirus 1

Human bocavirus(HBoV)1 is considered an important pathogen that mainly affects infants aged 6–24 months,but preventing viral transmission in resource-limited regions through rapid and affordable on-site diagnosis of individuals with early infection of HBoV1 remains somewhat challenging.Herein,we present a novel faster,lower cost,reliable method for the detection of HBoV1,which integrates a recombinase polymerase amplification(RPA)assay with the CRISPR/Cas12a system,designated the RPA-Cas12a-fluorescence assay.The RPA-Cas12a-fluorescence system can specifically detect target gene levels as low as 0.5 copies of HBoV1 plasmid DNA per microliter within 40 min at 37℃without the need for sophisticated instruments.The method also demonstrates excellent specificity without cross-reactivity to non-target pathogens.Furthermore,the method was appraised using 28 clinical samples,and displayed high accuracy with positive and negative predictive agreement of 90.9%and 100%,respectively.Therefore,our proposed rapid and sensitive HBoV1 detection method,the RPA-Cas12a-fluorescence assay,shows promising potential for early on-site diagnosis of HBoV1 infection in the fields of public health and health care.The established RPA-Cas12a-fluorescence assay is rapid and reliable method for human bocavirus 1 detection.The RPA-Cas12a-fluorescence assay can be completed within 40 min with robust specificity and sensitivity of 0.5 copies/μl.