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Deep learning-based automatic volumetric damage quantification using depth camera
摘要： A depth camera or 3-dimensional scanner was used as a sensor for traditional methods to quantify the identified concrete spalling damage in terms of volume. However, to quantify the concrete spalling damage automatically, the first step is to detect (i.e., identify) the concrete spalling. The multiple spots of spalling can be possible within a single structural element or in multiple structural elements. However, there is, as of yet, no method to detect concrete spalling automatically using deep learning methods. Therefore, in this paper, a faster region-based convolutional neural network (Faster R-CNN)-based concrete spalling damage detection method is proposed with an inexpensive depth sensor to quantify multiple instances of spalling simultaneously in the same surface separately and consider multiple surfaces in structural elements. A database composed of 1091 images (with 853 × 1440 pixels) labeled for volumetric damage is developed, and the deep learning network is then modified, trained, and validated using the proposed database. The damage quantification is automatically performed by processing the depth data, identifying surfaces, and isolating the damage after merging the output from the Faster R-CNN with the depth stream of the sensor. The trained Faster R-CNN presented an average precision (AP) of 90.79%. Volume quantifications show a mean precision error (MPE) of 9.45% when considering distances from 100 cm to 250 cm between the element and the sensor. Also, an MPE of 3.24% was obtained for maximum damage depth measurements across the same distance range.
关键词： Convolutional neural network,Deep learning,Concrete spalling,Depth sensor,Volume quantification
更新于2025-09-04 15:30:14
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Synthesis, Characterization and Gas-Sensing Properties of Pristine and SnS2 Functionalized TeO2 Nanowires
摘要： We report the gas-sensing properties of pristine and SnS2 functionalized TeO2 nanowires (NWs). TeO2 NWs were synthesized by a vapor–liquid–solid growth method, and SnS2 functionalization was performed using an atomic layer deposition technique followed by thermal treatment. Structural and morphological analyses verified the formation of pristine and SnS2 functionalized TeO2 NWs with desired composition, phase, and morphology. Interestingly, sensing results showed that the pristine TeO2 NW gas sensor had better sensing properties relative to the SnS2 functionalized TeO2 NW gas sensor. An underlying sensing mechanism is explained in detail, and reasons for the decrease of sensing performance with the SnS2 functionalized TeO2 NW sensor was attributed to the coverage of TeO2 surface by the SnS2 nanoparticles.
关键词： Gas sensor,SnS2,NO2 gas,TeO2,Sensing mechanism
更新于2025-09-04 15:30:14
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Four new luminescent-organic frameworks exhibiting highly sensing of nitroaromatics: an experimental and computational insight
摘要： Four new metal–organic frameworks (MOFs) namely {[Cd(L)(bpp)]·H2O}n (1), {[Zn(L)(bpp)]·H2O}n (2), {[Cd(L)(bpz)]·H2O}n (3), [Zn(L)(bib)(H2O)]n (4), (H2L = 1,4-bis(4-carboxylbenzyl)piperazine acid; bpp =1,3-bis(4-pyridyl)propane; bpz = 3,3′,5,5′-tetramethyl-4,4′-bipyrazole, bib = 1,4-bis(imidazol-1-yl)butane)) have been designed, synthesized and characterized. The MOFs 1 and 2 are isostructural and possess 4-connected dia topology with rare 8-fold interpenetrating network. In 3, the dianionic ligand L and bpz ligands link binuclear Cd(II) centres to generate a 2D layer framework with a double stranded chain. While in 4, the Zn(II) centres are bridged by L and bib ligands to furnish a 2D framework, which further generates a 3D supramolecular structure through the hydrogen bonding interactions formed between coordinated water molecules and carboxylate groups. The MOF 1 have been utilized as a possible luminescent sensor to detect nitroaromatic compounds (NACs). The results indicates that 1 showed good sensitivity towards p-nitrophenol (PNP) in comparison to other NACs by the decline in its luminescent intensity. The detection limit for PNP was found to be extremely low(1.27 ppm in solution) which represents one of the most efficient MOF-based sensors for PNP. The most plausible mechanism associated with sensing have been explained with the aid of theoretical calculations which indicated that a simultaneous electron/energy transfer phenomenon operating between 1 and NACs contributes toward the decline in the luminescence intensity
关键词： Nitroaromatic,Luminescence sensor,MOFs,Theoretical calculation
更新于2025-09-04 15:30:14
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A simple and rapid fluorescent approach for flavonoids sensor based on gold nanoclusters
摘要： The development of simple, easy-to-operate and real-time detection methods for the active ingredients in herbal medicines has aroused growing interest owing to their pivotal health benefits. In this study, a qualitative and quantitative detection method for the flavonoids was developed based on the specific interaction between flavonoids and bovine serum albumin (BSA). A fluorescent gold nanocluster was imbedded into the cavity enclosed in the tertiary structure of BSA, the fluorescence of which can be quenched by the flavonoids with fast response (< 5 s). This decrease in fluorescence intensity of BSA-AuNCs as output signal enables the real-time visual inspection of flavonoids. We demonstrated that the present approach was capable of detecting quercetin in serum, plasma, and monitoring the content of flavonoids in proprietary Chinese medicine Rutin Tablets. BSA-AuNCs was the first fluorescent probe for the specific determination of active ingredients in herbal medicines. Hence the reported protein-AuNCs sensing platform can serve as a convenient detection strategy in pharmaceutical analysis.
关键词： sensor,fluorescence probe,Gold nanoclusters,flavonoids
更新于2025-09-04 15:30:14
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Polymeric Micelles Encapsulating a Small Molecule SO <sub/>2</sub> Fluorescent Probe Exhibiting Novel Analytical Performance and Enhanced Cellular Imaging Ability
摘要： Because of the limited knowledge on the relationship between molecular structure and analytical performance, developing a small molecule fluorescent probe with desirable response properties is usually a laborious work. On the other hand, the application of small molecule fluorescent probe in biological samples is always limited due to the unwanted interaction between dyes and biomacromolecules. Polymer micelles, thanks to its unique core?shell structure, may have the potential to improve these situations. However, utilization of polymer micelles to improve these situations is rarely explored. Herein, we engineered the first micellar SO2 nanoprobe Nano-Cz by self-assembly of a carbazole-based SO2 small molecule probe and an amphiphilic copolymer (DSPE-mPEG2000). The optical and cell imaging experiments revealed that Nano-Cz can work in 100% aqueous environment and act as an effective mitochondrial-targeting ratio SO2 nanoprobe. Compared with the single small molecule probe, Nano-Cz showed extraordinary large dynamic response range (0?0.7 mM vs 0?50 μM), eliminated signal interference from DNA and superior cellular imaging performance. These results clearly show the ability of polymer micelles in modulating sensors’ analytical performance and reducing the signal interference from the unwanted interaction between small molecule probe and biomacromolecule, indicating that polymer micelles encapsulating single small molecule probe can provide us an alternative strategy to explore sensors with various performance and promote the biological application of fluorescent sensors. In addition, we hope that more and more polymer micelles would be used to construct biosensors in the future.
关键词： sensing performance,biological application,sulfur dioxide,polymer micelles,fluorescent sensor
更新于2025-09-04 15:30:14
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An Electrogenerated Chemiluminescence Biosensor using a tripod probe for the Highly Sensitive Detection of MicroRNA
摘要： A novel probe for highly sensitive detection of microRNA, that enhanced the helix accessibility and yielded good assembling without backfilling, was developed using a tripod structure fabricated by triplex DNA. A layer of triplex DNA assembled on electrodeposited reduced graphene oxide was used as the capture probe and a subsequent hybridization chain reaction that promoted the efficient intercalation of the electrogenerated chemiluminescence(ECL) emitter [Ru(bpy)2(dppz)]2+ (bpy = 2,2′-bipyridine, dppz = dipyrido[3,2-a: 2′,3′-c]phenazine) was used an analytical signal amplifier. The fabricated biosensor was examined with an anodic ECL mode using tri-n-propyl amine as the coreactant. The construction of the biosensor was systematically characterized with various techniques including atomic force microscopy, gel electrophoresis, cyclic voltammetry, and electrochemical impedance spectroscopy, and its performance was optimized under a variety of experimental conditions especially the concentration of each reagent as well as its incubation time. Under the optimal experimental conditions, the reported biosensor showed a very low limit of detection of 0.10 fM (S/N = 3) and a wide linear dynamic range covering from 0.50 fM to 100 pM towards microRNA-155, with excellent specificity, stability, and reproducibility. Finally, the biosensor was successfully applied to detect the amount of microRNA-155 extracted from the colon cancer cell line DLD1, demonstrating its potential applications in sensitive detection of biological samples in early diagnosis of diseases.
关键词： Triplex DNA,HCR,ECL sensor,MicroRNA
更新于2025-09-04 15:30:14
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Improved ATR-FTIR detection of hydrocarbons in water with semi-crystalline polyolefin coatings on ATR elements
摘要： In situ measurement of hydrocarbons in water is critical for assuring the safety and quality of drinking water and in environmental remediation activities such as the cleanup of oil spills. Thus, effective detection methods of hydrocarbons in aqueous environments are important and several methods have been used for this type of sensing, including spectroscopic techniques, fiber optic sensors, and chromatography. However, under aqueous conditions, small amounts of hydrocarbons are difficult to detect due to their low concentration in water and robust sensing of these types of compounds in an aqueous environment remains a challenging analytical task. Hydrophobic polymer coatings have been widely used to concentrate hydrocarbons for attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) detection at the surface of an ATR crystal by preventing water molecules from penetrating into the polymer coating while absorbing hydrocarbons. However, in typical coating designs only thin films (<5 μm) can be applied onto the ATR sensor due to the decrease in detection limit and sensitivity to hydrocarbons with increasing film thickness. This paper demonstrates that a semi-crystalline linear low-density polyethylene (LLDPE) polymer coating with thicker thickness (40 μm) can be applied effectively for in situ ATR-FTIR detection of hydrocarbons in aqueous solution. The ATR signal is enhanced by the polymer coating which swells in response to the hydrocarbons and prevents water accumulation at the IR detection interface. Coating the ATR element with a LLDPE film (crystallinity = 12%) reduced the detection time for various hydrocarbons, including toluene, benzene and chloroform. The detection limits and kinetics of the ATR-FTIR detection were not significantly altered when the thickness of the LLDPE coating was increased to improve its mechanical properties which represents a significant improvement from coatings published in the literature. The LLDPE coating described in this research has the potential to be applied as a sensor coating for rapid detection of hydrocarbon-based substances or non-polar biomolecules in aqueous environments.
关键词： LLDPE,water,hydrocarbons,ATR-FTIR,sensor
更新于2025-09-04 15:30:14
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Characterisation of sensor kinase by CD spectroscopy: golden rules and tips
摘要： This is a review that describes the golden rules and tips on how to characterise the molecular interactions of membrane sensor kinase proteins with ligands using mainly circular dichroism (CD) spectroscopy. CD spectroscopy is essential for this task as any conformational change observed in the far-UV (secondary structures (α-helix, β-strands, poly-proline of type II, β-turns, irregular and folding) and near-UV regions [local environment of the aromatic side-chains of amino acid residues (Phe, Tyr and Trp) and ligands (drugs) and prosthetic groups ( porphyrins, cofactors and coenzymes (FMN, FAD, NAD))] upon ligand addition to the protein can be used to determine qualitatively and quantitatively ligand-binding interactions. Advantages of using CD versus other techniques will be discussed. The difference CD spectra of the protein–ligand mixtures calculated subtracting the spectra of the ligand at various molar ratios can be used to determine the type of conformational changes induced by the ligand in terms of the estimated content of the various elements of protein secondary structure. The highly collimated microbeam and high photon flux of Diamond Light Source B23 beamline for synchrotron radiation circular dichroism (SRCD) enable the use of minimal amount of membrane proteins (7.5 mg for a 0.5 mg/ml solution) for high-throughput screening. Several examples of CD titrations of membrane proteins with a variety of ligands are described herein including the protocol tips that would guide the choice of the appropriate parameters to conduct these titrations by CD/SRCD in the best possible way.
关键词： high-throughput screening,circular dichroism,synchrotron radiation circular dichroism,membrane sensor kinase,ligand-binding interactions
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE 18th International Conference on Bioinformatics and Bioengineering (BIBE) - Taichung, Taiwan (2018.10.29-2018.10.31)] 2018 IEEE 18th International Conference on Bioinformatics and Bioengineering (BIBE) - Nonlinear CMOS Image Sensor with SOC Integrated Local Contrast Stretch for Bio-Microfluidic Imaging
摘要： a nonlinear single-slope ADC with SOC integrated local contrast stretch using a configurable multi-frequency counter for bio-microfluidic imaging is presented in this paper. Compared with the conventional off-chip global contrast stretching algorithm, this method does not degrade image quality at the interested light intensity range (cell) at the cost of unconsidered range (sheath fluid) and can be integrated into CMOS image sensor directly. Meanwhile, this method provides higher precision of cell image for the later super-resolution reconstruction. The simulation results indicate that more details of cell image can be obtained in this method.
关键词： contrast stretch,CMOS image sensor,point-of-care (POC) diagnosis,bio-microfluidic imaging
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE International Conference on Mechatronics and Automation (ICMA) - Changchun (2018.8.5-2018.8.8)] 2018 IEEE International Conference on Mechatronics and Automation (ICMA) - Status and Trends of the Large Aperture Space Optical Remote Sensor
摘要： Aiming at catching up with the leading countries, this paper gives the right development direction of large aperture optical remote sensor in China. Firstly, we introduced the current situation of large aperture remote sensors using traditional and new imaging systems. Then we summarized the monolithic and deployable remote sensors with full range spectra and high spectrum resolution are the future main development trends. Furthermore, we discussed the key technologies include large aperture lightweight monolithic reflective mirror, active support, precise deployment, co-phasing in orbit, fabrication of large aperture membrane diffractive optics element (DOE) and high performance imaging processing technology of interferometric imaging system. Finally, we conclude China should give more attention to the large aperture monolithic and deployable optical remote sensors, and tackle the key technology in 1.5m~3m aperture monolithic remote sensors at first step and 4m aperture monolithic and the deployable remote sensors next.
关键词： large aperture space optical remote sensor,interference imaging,optical synthetic aperture diffraction imaging,imaging,space deployable segmented imaging
更新于2025-09-04 15:30:14