Visual Real-time Monitoring Research Articles

A novel and facile oxygen-activated time-temperature indicator with wide temperature monitoring range and good stability based on the laccase-like nanozyme

BackgroundTime-Temperature Indicator (TTI) is an indicator device for real-time monitoring of the thermal history of the product. Due to the enzymatic reactions are affected by both time and temperature, enzymatic TTIs have been extensively studied and developed in recent years. However, enzymatic TTIs contain biologically active molecules (enzymes), which require high storage and use conditions. Most of them are designed to mix the system species together and irreversible reaction is undertaken. Nanozymes are the synthetic nanomaterials with similar biocatalytic functions as natural enzymes, which have extensive applications in analytical chemistry, biosensing, and environmental protection due to their facile synthesis, low cost, high stability and durability. ResultsThis work proposed to replace the natural laccase to laccase-like nanozyme, designed a novel and facile O2-activated time-temperature indicator for the first time. Nanozyme had excellent thermal and storage stability, which could maintain fabulous catalytic activity in the wide temperature range of 10–80 °C and after a long-term storage. Based on the O2 was required to participate in the oxidation of laccase-catalyzed substrates, a squeeze-type O2-activated TTI was designed by controlling O2 in the TTI system. The TTI was activated through extruding the O2-coated airbag ruptured and producing an irreversible color reaction. Combined with a smartphone to extract the chromaticity for portable visual real-time monitoring. Five sets of TTIs were prepared based on the concentration of nanozyme, and the activation energies (Ea) ranging from 28.45 to 72.85 kJ mol−1, which were able to be fitted to products with Ea ranging from 3.45 to 97.8 kJ mol−1 and the monitoring-time of less than 7 days. SignificanceCompared to the traditional enzymatic TTI, the TTIs designed based on nanozyme has the advantages of controlled activation, wider temperature monitor range and good stability. Providing a new approach to the development of real-time monitoring of smart devices.

Nanoengineered Nonenzymatic Paper-Based Fluorescent Platform for Pre-Dilution-Free and Visual Real-Time Home Monitoring of Urea for Early Warning of Abnormal Nitrogen-Based Unhealthy Issues.

Distorted urea levels indicate several liver, kidney, or metabolic diseases; however, traditional clinical urea detection relies on urease-based methods enslaved to well-known limitations of high-price, unstable properties, complicated sample pretreatment and analysis procedures, and difficult visual real-time monitoring. Herein, nonenzymatic paper-based fluorescent materials (UFP-BP) are strategically integrated with an on-demand fluorescent-sensor (UFP) self-aggregated nanoparticle on commercial filter paper for pre-dilution-free and visual real-time urea monitoring. The UFP is synthesized and self-aggregated into the fluorescent nanoparticles for selective urea recognition. Then, the nanoparticles are interstitially loaded on filter paper to nanoengineer the UFP-BP, achieving selective quantitative urea detection in the normal concentration range (10-1000mm). UFP and UFP-BP can successfully monitor urea levels in real rat urine, artificial simulants, and milk. The proposed sensing platform, integrated with smartphones, offers accurate, quantitative, nonenzymatic, noninvasive, pre-dilution-free, on-site, rapid, low-cost, easy-to-operate, real-time visual urea detection in food samples and human body fluids. The designed sensing system can provide early warnings of abnormal nitrogen-based health issues.

The full utilization of bagasse via deep eutectic solvent pretreatment for low-condensed lignin and cellulose smart indicator film

Full utilization of biomass after fractionation of its components is an effective way to maximize the value of biomass. Herein, in this study, a new acetal-mediated deep eutectic solvent (DES) was explored and its excellent performance in separating lignin from biomass as well as retarding lignin condensation has been observed. Subsequently, the separated lignin and cellulose-rich residue were used to prepare sunscreen and transparent food indicator films, respectively. The results showed that the acetal-mediated DES pretreatment can reduce the recalcitrance of bagasse, stabilize lignin (β-O-4 content of 68.6% in the lignin), and retain most of the cellulose (ie. 83.43%). Besides, the pretreatment enhanced the subsequent hydrogenolysis of lignin, and the higher β-O-4 content of the lignin contributed to the high yield of aromatic monomers (40.94%). In addition, regenerated lignin was attractive for sunscreen applications due to its lighter color and excellent UV-blocking properties. Furthermore, cellulose smart indicator film was highly sensitive, biodegradable, has excellent physical properties, and allows visual real-time monitoring of seafood spoilage using smartphones. Meanwhile, the yield of the removed hemicellulose converted to xylose in the pretreatment process reached 99.24%. In general, this work proposed a sustainable bio-refinery approach for the full upgrading of biomass.

Packaged europium/fluorescein-based hydrogen bond organic framework as ratiometric fluorescent probe for visual real-time monitoring of seafood freshness

The freshness of sea food has always been the focus of attention from consumers, and food-safety issues are in urgent need of efficient approaches. A HOF-based ratiometric fluorescence probe (HOF-FITC/Eu) featuring superior amine-response, offers the real-time and visual detection of seafood freshness. Via intermolecular hydrogen bond interaction to form hydrogen-bonded organic frameworks (HOFs), which serve as a structural basis for the conjugate loading of pH-sensitive fluorescein (5-FITC) and coordination doping of lanthanide Eu3+. Amine vapors stimulate the dual-wavelength (525 nm and 616 nm) characteristic fluorescence of HOF-FITC/Eu with an inverse trend, resulting in an increase of the ratio of I525 to I616 accompanied by a distinct color transition from red to green. Prepared HOF-FITC/Eu featuring sensitive red-green color change characteristics of amine response are readily dripped into composite films of filter paper through integrated smartphone and 254 nm UV lamp as mobile observation devices to on-site monitor the freshness of raw fish and shrimp samples. The intelligent food probe HOF-FITC/Eu opens a novel material assembly type for fluorescence sensing and a potential pathway for other functional materials in the field of investigational food.

A paper-based ratiometric fluorescent sensor for NH3 detection in gaseous phase: Real-time monitoring of chilled chicken freshness

A ratiometric fluorescence sensor platform with easy-to-use and accurate is nanoengineered for NH3 quantitative detection and visual real-time monitoring of chicken freshness using smartphones. The ratiometric fluorescent probe formed by combining the zinc ion complex and carbon dots has a double-emitted fluorescence peak. The fluorescence intensity of the complex changed can be clearly observed with the increase of the concentration of ammonia solution under 365 nm wavelength excitation. In order to detect NH3 concentration in gaseous phase, a portable paper-based sensor was designed. The sensor had a good linear relationship with NH3 concentration ranging from 10.0 to 90.0 μmol/L and the LOD value was 288 nM. This fluorescent paper-based sensor was used to check the freshness of chicken breast refrigerated at 4 °C, revealed observable shifts from blue to green. The fluorescent paper-based sensor can detect NH3 concentration in real time and simplify the monitoring process of meat freshness while ensuring accuracy and stability.

Diagnosis of cryptocaryoniasis in large yellow croaker (Larimichthys crocea) by real-time object detection based on YOLOv3

With the introduction and deepening of the concept of sustainable aquaculture, the traditional aquaculture practices are gradually being supplemented and even replaced by advanced systems based on new technology. We here present an automated diagnostic method for diagnosis of cryptocaryoniasis in industrial marine aquaculture. It is based on computer image recognition technology targeting the typical clinical disease sign, white skin spots. A total of 800 images of healthy (400) and Cryptocaryon irritans infected (400) large yellow croaker (Larimichthys crocea) were obtained by cameras, and each type of image was enhanced to 1000. Based on the algorithm YOLOv3, the weights of the trained model yolov3.pt. were used to perform transfer learning on the enhanced image data set to establish the diagnosis model YOLOv3 of cryptocaryoniasis of L. crocea. Then, a visual real-time monitoring system for cryptocaryoniasis was developed. The results show that transfer learning could be well-applied to the training of the cryptocaryoniasis detection model. The accuracy of the final model was about 2% higher than that of the source model (average accuracy of YOLOv3 was 92%, recognition speed 36 frames/s). The algorithm YOLOv3 allows effective discrimination and recognition of cryptocaryoniasis in large yellow croaker. The visual real-time monitoring system allows the automatic and accurate diagnosis of cryptocaryoniasis in L. crocea aquaculture. The results illustrate the applicability of artificial intelligence for reduction of manpower expenditure in diagnostic work, shortening of detection time and elevation of accuracy and timeliness of problem recognition.

Biphenyl-based AIE-active turn-on fluorescent probes for simultaneous sensing of biothiols and amine vapors and visual real-time monitoring of seafood spoilage

Abnormal level of biothiols content in living organisms and volatile vapor amines could cause severe injury to human health, development of convenient and portable detecting devices for the biothiols and amines recognition is bound to scientific significance as well as practical application. Up to now, mainly confined by aggregation caused quenching (ACQ) effect, the potential application of traditional fluorescent sensing were extremely restricted. In this contribution, two biphenyl-based “turn-on” type fluorescent probes FCH-NBSC and FCH-AC were designed and constructed for biothiols and vapor amines quantitative detection respectively, which were consisted of a common fluorophore FCH–OH with AIE properties and two sensitive recognition segments nitrobenzene sulfonyl chloride (NBSC) and acetyl (AC). Date from experiments demonstrated that probe FCH-NBSC and FCH-AC exhibited excellent linearity and low detection limits for detection of biothiols (Cys, 0.228 μM, GSH, 0.212 μM, Hcy, 0.315 μM, vapor amine, 7.6 ppm), respectively. Sensing mechanism demonstrated that this fluorescent characteristics variation could be ascribed to biothiols and vapor amines caused cleavage of NBSC segment of FCH-NBSC and AC group of FCH-AC respectively to form a common ESIPT compound FCH–OH, which opened aggregation induced emission (AIE) property promoted by intra/intermolecular H-bonds. Furthermore, FCH-NBSC can successfully achieve rapid biothiols recognition inside biological cells via difference in fluorescent signals due to its low toxicity and high sensitivity. Meanwhile, probe FCH-AC have been applied in visual real-time monitoring of seafood spoilage field due to its unique recognition effect for amine vapor.

Paper-based fluorescent materials containing on-demand nanostructured brain-cells-inspired AIE self-assembles for real-time visual monitoring of seafood spoilage

Biogenic amines containing NH3 are important indicators for conducting full-scale appraisal of food spoilage and disease diagnosis. However, the currently-used detection methods of NH3 have several limitations such as time-consuming high cost, and inability to provide visual real-time monitoring. Therefore, researchers have attempted to explore strategies for quantitative real-time monitoring of NH3 for food spoilage has attracted widespread attentions. Herein, we developed sustainable, fast response, hypersensitized, user-friendly and molecular-level light-emitting biomass-based materials (AFP-FP) containing on-demand nanostructured brain-cells-inspired aggregation-induced-emission (AIE) self-assembles for real-time visual monitoring of seafood spoilage. The 2-hydroxy-5-methyl-isophthalaldehyde-based AIE probe (AFP) was synthesized using a simple “one-step” route. AFP-FP exhibited high selectivity, sensitivity, repeatable and quantitative recognition (y = 7.292×103x + 7.621×104, R = 0.990) of NH3 with a low detection limit (246 ppb) and fast response (<1 s). Furthermore, we integrated AFP-FP into a user-friendly smartphone color recognition app, enabling its practical application in visual, real-time daylight monitoring of food spoilage.

Feasibility Study of Early Pressure Ulcer Detection Using Electrical Impedance Tomography

Pressure ulcers are chronic skin wounds with a particularly high morbidity and a relatively low recovery rate. At present, there is still a lack of a portable and visual real-time monitoring system for early pressure ulcers. Electrical impedance tomography (EIT) is a kind of functional imaging technique that can diagnose the healthy condition in the measured tissues by visualizing the distribution of bioelectrical impedance parameters. According to the principle of electrical characteristic of pressure ulcers, i.e., changes in physiological and pathological information of tissues caused by pressure lead to changes in electrical impedance of tissues, a non-invasive imaging system of pressure ulcers based on EIT with novel flexible electrode array is proposed. Two kinds of 3D finite element simulation models are constructed to discuss the measurement effects of the flexible array on simulated pressure ulcers at different locations, depths, and with different sizes. The effects of different imaging algorithms on imaging results are also compared and analyzed. Physical phantom model experiments and preliminary experiments on human skin are conducted. Both simulations and physical experiments indicate that EIT technique is excepted to realize a safer, portable, low-cost and visual real-time monitoring system for early pressure ulcers.

A benzothiazole-based fluorescent probe for sensing Zn2+ and its application

A novel probe L based on benzothiazole was synthesized and characterized. The sensing performance was investigated by fluorescence spectrometry. The results showed that probe L had a single selective recognition towards Zn2+ with a low detection limit (0.678 μM) in DMSO/Tris-HCl buffer solution. The binding ratios between L and Zn2+ were 1: 1. The pH test showed that L had a wide detection range of 7–10 for Zn2+. Probe L responds very fast to Zn2+ about 30 s. The recognition mechanism was studied by 1H NMR, mass spectrum analysis and theoretical calculations. The test strips and fluorescence film experiments of the probe show that probe L can detect liquid and solid zinc salts, revealing that the probe is expected to be used for portable visual real-time monitoring of liquid and solid zinc salts. Notably, probe L was successfully applied in different water samples and living Hela cells for the determination and imaging of Zn2+ respectively.

Fly-antennae-inspired biomass-based fluorescent platform for NH3 quantitative detection and visual real-time monitoring of seafood spoilage

Traditional strategies for quantitative detection of NH3 and monitoring of seafood spoilage still have some pervasive issues of cumbersome operation, time-consuming, high-cost, and inefficient real-time monitoring, and visualization. Integration of biomass-based materials and aggregation-induced emission (AIE) fluorescence probes exhibit conceivable potential in seafood detection and environmental monitoring. Herein, a fly-antennae-inspired biomass-based solid-state fluorescent platform (PAA-FP) with effective, easy-to-use, reusable, low-cost and highly sensitive characteristics is nanoengineered for NH3 quantitative detection (detection limit = 0.5 ppm) and visual real-time monitoring of seafood spoilage using smartphones. The PAA-FP possesses an anticipative “fly-antennae-like” microstructure and offers selective recognition of NH3 by naked eyes in daylight with excellent solid-state fluorescence properties. Moreover, PAA-FP is simply reused at least 5 times after AcOH fumigation. Comprehensive application experiments substantiate that PAA-FP successfully achieves quantitative detection of NH3 and realizes the visual real-time daylight monitoring of food spoilage using a simple color recognizing smartphone software. The present study demonstrates an effective fabrication strategy to explore various multifunctional biomass-based materials for sensing hazardous and noxious substances.

Development of a self-calibration method for real-time monitoring of SO2 ship emissions with UV cameras.

Self-calibration of UV cameras was demonstrated for the first time. This novel method has the capability of real-time continuous calibration by using the raw images at 310 nm and 330 nm without changing the viewing direction or adding any additional equipment. The methodology was verified through simulations and experiments and demonstrated to be of greatly improved effectiveness and accuracy. The errors of self-calibration mothed are estimated by comparison with the differential optical absorption spectroscopy (DOAS) approach, and it can be reduced to 1.8% after filter transmittance corrections. The results show that the self-calibration method appears to have great potential as a future technique for quantitative and visual real-time monitoring of SO2 emissions from ships and other point sources (such as oil refineries, power plants, or more broadly, any industrial stack) when the field of view (FOV) of the system is not completely covered by the SO2 plumes.

A body-weight-supported visual feedback system for gait recovering in stroke patients: A randomized controlled study

ObjectiveThe aim of this study was to determine the effectiveness of a novel body-weight-supported (BWS) gait training system with visual feedback, called Copernicus® (Rehalife, Italy). This computerized device provides comfortable, regular and repeatable locomotion in hemiplegic patients. Through visual real-time monitoring of gait parameters, patients are trained to transfer weight loading alternately on both feet. DesignA single-blind, randomized controlled study. A single center used a computer-generated randomization code to allocate treatments. SettingIntensive rehabilitation unit (IRU) at the Institute S. Anna (Italy). Participants63 first-ever stroke patients (39 men, age: 66.1 ± 9.6 years; 61.6 % with left-sided lesion) randomly distributed into three demographically/clinically matched groups. TreatmentsAll groups were treated five times a week for 2 -h sessions for six consecutive weeks. The first group (“control”) underwent a conventional physical therapy; the second group performed advanced BWS gait training sessions without visual feedback (Experimental VF- group); whereas the third group used BWS with visual feedback stimulation (Experimental VF+ group). Main Outcome MeasuresAbsolute changes were recorded using conventional clinical scales and kinematic measurement of static gait balance from baseline to follow-up. ResultsSignificant interaction Group*Time effects scales (F2,126 = 5.1, p-level = 0.005, η²p = 0.25; F2,126 = 4.7, p-level = 0.007, η²p = 0.19; respectively) were detected in the Functional Independence Measure and Tinetti-Balance scales. Post hoc analysis demonstrated that the recovery of motor functioning was greater for the VF + group with respect to other groups (all p’s ≤ 0.001). A similar pattern of findings was also obtained with a stabilometric analysis, demonstrating a better clinical improvement in static balance after VF + treatment. ConclusionThe proposed advanced rehabilitation system with visual feedback was more effective in improving gait recovery with respect to conventional and high-tech therapies without a sensor feedback.

A machine for real-time estimation of the tribological characteristics of materials

A reciprocating friction machine Tribal-T intended for automated quality control of the rubbing surfaces of tribopairs is described. The distinctive feature of the machine consists in implementation of the forced relative motion due to the frictional interaction of the rubbing surfaces fixed on the drive and conjugate platforms. Continuous processing of the signals from displacement sensors is carried out under conditions of continuous recording of mutual displacements of loaded tribopairs using classical approaches of the theory of automatic control to identify the tribological characteristics. The machine provides consistent visual real time monitoring of the parameters. The MATLAB based computer technologies are actively used in data processing. The calculated tribological characteristics of materials, i.e., the dynamic friction coefficient, damping coefficient and measure of the surface roughness, are presented. The tests revealed that a Tribal-T reciprocating friction machine is effective for real-time study of the aforementioned tribological characteristics of materials and can be used for monitoring of the condition of tribo-nodes of machines and mechanisms.

ScatterBlogs2: Real-Time Monitoring of Microblog Messages through User-Guided Filtering

The number of microblog posts published daily has reached a level that hampers the effective retrieval of relevant messages, and the amount of information conveyed through services such as Twitter is still increasing. Analysts require new methods for monitoring their topic of interest, dealing with the data volume and its dynamic nature. It is of particular importance to provide situational awareness for decision making in time-critical tasks. Current tools for monitoring microblogs typically filter messages based on user-defined keyword queries and metadata restrictions. Used on their own, such methods can have drawbacks with respect to filter accuracy and adaptability to changes in trends and topic structure. We suggest ScatterBlogs2, a new approach to let analysts build task-tailored message filters in an interactive and visual manner based on recorded messages of well-understood previous events. These message filters include supervised classification and query creation backed by the statistical distribution of terms and their co-occurrences. The created filter methods can be orchestrated and adapted afterwards for interactive, visual real-time monitoring and analysis of microblog feeds. We demonstrate the feasibility of our approach for analyzing the Twitter stream in emergency management scenarios.

Supervisory Control of Silicon Steel Plant Dust Removal System Based on Configuration Technology

This paper introduces the real-time monitoring provided by the function of PLC control system based on the configuration control technology in silicon steel plant. Visual real-time monitoring of silicon steel flue gas dust removal system, the main parameters includes: working condition of the two temperature sensor in flue pipe, air conditioning butterfly valve, bag type dust trap system, high pressure fan, dust conveying system, dust unloading system and cleaning system, etc. Moreover, monitoring and give an alarm in case the failure of dust removal system appears appears in the course of their work. This paper also introduces the hardware components and software components of the visual real-time monitoring of silicon steel flue gas dust removal system, and their applications. And discuss how to use configuration technology develop and design real-time monitoring system.

A novel RO ex situ scale observation detector (EXSOD) for mineral scale characterization and early detection

A novel RO ex situ scale observation detector (EXSOD) was developed for direct visual real-time monitoring of mineral surface scaling on RO membranes. This system consists of a plate-and-frame RO cell with an optical window capable of withstanding pressures in excess of 2.4 MPa. Membrane surface imaging under RO operation is accomplished by high resolution digital photography using an optical microscope with lighting arrangement to enhance the boundaries of semi-transparent crystals. The utility of the direct membrane surface observation cell was demonstrated in a series of experiments conducted with a commercial brackish water RO membrane and with gypsum selected as the model scalant. The present study demonstrated, for the first time, a capability for early detection of mineral salt scaling at very early stages of formation, in advance of any measurable flux decline. The approach also illustrates that surface crystal development on RO membranes can be quantified with respect to both single crystal growth and the evolution of crystal number surface density. For the growth of gypsum, crystal surface number density evolved according to a sigmoidal growth curve, with crystal growth diminishing as gypsum rosette needles began to overlap. Dissolution of surface crystals occurred once solution at the membrane surface was undersaturated with respect to gypsum. It is suggested that the EXSOD system can be used for on-line monitoring of scaling and fouling in RO plants, evaluation of the impact of colloidal and biofouling as well as the effectiveness of antiscalants and membrane cleaning strategies.