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Alkaline Phosphatase-Triggered Self-Assembly of Near-Infrared Nanoparticles for Enhanced Photoacoustic Imaging of Tumor
摘要： Photoacoustic (PA) imaging is advantageous for the diagnosis of superficial cancer with high spatial resolution. However, to the best of our knowledge, using an alkaline phosphatase (ALP)-activatable probe for enhanced PA imaging of tumor has not been reported. In this work, we rationally designed a NIR probe IR775-Phe-Phe-Tyr(H2PO3)-OH (1P) for PA imaging ALP activity in vitro and in tumor. Under the catalysis of ALP, 1P was efficiently converted to IR775-Phe-Phe-Tyr-OH (1) which self-assembled into the nanoparticles 1-NPs. Formation of 1-NPs induced a 6.4-fold enhancement of the 795 nm PA signal of 1P. In vivo tumor PA imaging results indicated that, compared with that in the ALP inhibitor-treated control group, PA contrast in the experimental group enhanced 2.3 folds at 4 h post 1P injection. By replacing the Phe-Phe-Tyr(H2PO3)-OH motif in 1P with other enzyme-cleavable ones, we hope more PA probes could be developed for the precise diagnoses of their corresponding cancers in the near future.
关键词： photoacoustic imaging,near-infrared nanoparticle,alkaline phosphatase,self-assembly
更新于2025-09-09 09:28:46
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A Novel Method for Classifying Driver Mental Workload Under Naturalistic Conditions With Information From Near-Infrared Spectroscopy
摘要： Driver cognitive distraction is a critical factor in road safety, and its evaluation, especially under real conditions, presents challenges to researchers and engineers. In this study, we considered mental workload from a secondary task as a potential source of cognitive distraction and aimed to estimate the increased cognitive load on the driver with a four-channel near-infrared spectroscopy (NIRS) device by introducing a machine-learning method for hemodynamic data. To produce added cognitive workload in a driver beyond just driving, two levels of an auditory presentation n-back task were used. A total of 60 experimental data sets from the NIRS device during two driving tasks were obtained and analyzed by machine-learning algorithms. We used two techniques to prevent overfitting of the classification models: (1) k-fold cross-validation and principal-component analysis, and (2) retaining 25% of the data (testing data) for testing of the model after classification. Six types of classifier were trained and tested: decision tree, discriminant analysis, logistic regression, the support vector machine, the nearest neighbor classifier, and the ensemble classifier. Cognitive workload levels were well classified from the NIRS data in the cases of subject-dependent classification (the accuracy of classification increased from 81.30 to 95.40%, and the accuracy of prediction of the testing data was 82.18 to 96.08%), subject-independent classification (the accuracy of classification increased from 84.90 to 89.50%, and the accuracy of prediction of the testing data increased from 84.08 to 89.91%), and channel-independent classification (classification 82.90%, prediction 82.74%). NIRS data in conjunction with an artificial intelligence method can therefore be used to classify mental workload as a source of potential cognitive distraction in real time under naturalistic conditions; this information may be utilized in driver assistance systems to prevent road accidents.
关键词： mental workload,near-infrared spectroscopy,artificial intelligence,driver attention,cognitive distraction,classification
更新于2025-09-09 09:28:46
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Visible-Near-Infrared Spectroscopy Prediction of Soil Characteristics as Affected by Soil-Water Content
摘要： Soil physical characteristics are important drivers for soil functions and productivity. Field applications of near-infrared spectroscopy (NIRS) are already deployed for in situ mapping of soil characteristics and therefore, fast and precise in situ measurements of the basic soil physical characteristics are needed at any given water content. Visible-near-infrared spectroscopy (vis–NIRS) is a fast, low-cost technology for determination of basic soil properties. However, the predictive ability of vis–NIRS may be affected by soil-water content. This study was conducted to quantify the effects of six different soil-water contents (full saturation, pF 1, pF 1.5, pF 2.5, pF 3, and air-dry) on the vis–NIRS predictions of six soil physical properties: clay, silt, sand, water content at pF 3, organic carbon (OC), and the clay/OC ratio. The effect of soil-water content on the vis–NIR spectra was also assessed. Seventy soil samples were collected from five sites in Denmark and Germany with clay and OC contents ranging from 0.116 to 0.459 and 0.009 to 0.024 kg kg-1, respectively. The soil rings were saturated and successively drained/dried to obtain different soil–water potentials at which they were measured with vis–NIRS. Partial least squares regression (PLSR) with leave-one-out cross-validation was used for estimating the soil properties using vis–NIR spectra. Results showed that the effects of water on vis–NIR spectra were dependent on the soil–water retention characteristics. Contents of clay, silt, and sand, and the water content at pF 3 were well predicted at the different soil moisture levels. Predictions of OC and the clay/OC ratio were good at air-dry soil condition, but markedly weaker in wet soils, especially at saturation, at pF 1 and pF 1.5. The results suggest that in situ measurements of spectroscopy are precise when soil-water content is below field capacity.
关键词： Visible-Near-Infrared Spectroscopy,Soil Physical Properties,Soil Characteristics,Soil-Water Content,Partial Least Squares Regression
更新于2025-09-09 09:28:46
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Zebrafish larvae show negative phototaxis to near-infrared light
摘要： Zebrafish larvae (Danio rerio) are among the most used model species to test biological effects of different substances in biomedical research, neuroscience and ecotoxicology. Most tests are based on changes in swimming activity of zebrafish larvae by using commercially available high-throughput screening systems. These systems record and analyse behaviour patterns using visible (VIS) and near-infrared (NIR) light sources, to simulate day (VIS) and night (NIR) phases, which allow continuous recording of the behaviour using a NIR sensitive camera. So far, however, the sensitivity of zebrafish larvae to NIR has never been tested experimentally, although being a critical piece of information for interpreting their behaviour under experimental conditions. Here, we investigated the swimming activity of 96 hpf (hours post fertilization) and 120 hpf zebrafish larvae under light sources of NIR at 860 nm and at 960 nm wavelength and under VIS light. A thermal source was simultaneously presented opposite to one of the light sources as control. We found that zebrafish larvae of both larval stages showed a clear negative phototactic response towards 860 nm NIR light and to VIS light, but not to 960 nm NIR light. Our results demonstrated that zebrafish larvae are able to perceive NIR at 860 nm, which is almost identical to the most commonly used light source in commercial screening systems (NIR at 850 nm) to create a dark environment. These tests, however, are not performed in the dark from the zebrafish′s point of view. We recommend testing sensitivity of the used test organism before assuming no interaction with the applied light source of commonly used biosensor test systems. Previous studies on biological effects of substances to zebrafish larvae should be interpreted with caution.
关键词： Zebrafish larvae,near-infrared light,high-throughput screening systems,negative phototaxis,behavioral response
更新于2025-09-09 09:28:46
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AIP Conference Proceedings [Author(s) GREEN DESIGN AND MANUFACTURE: ADVANCED AND EMERGING APPLICATIONS: Proceedings of the 4th International Conference on Green Design and Manufacture 2018 - Ho Chi Minh, Vietnam (29–30 April 2018)] - Quantification of acidity and total soluble solids in guavas by near infrared hyperspectral imaging
摘要： In order to provide premium quality for marketing of guavas the titratable acidity (TA) and total soluble solids (TSS) levels should be determined. A reflectance near infrared hyperspectral imaging (NIR-HSI) unit in the wavelength range of 936-1696 nm, which is a nondestructive technique, was tested for use in predicting TA and TSS. Samples of 100 guavas were scanned by NIR-HIS as a group for calibration (N=67) and as a group for prediction (N=33). The average spectra from the region of interest ( ROI) of samples were used to establish the calibration models for TA and TSS by using partial least squares regression ( PLSR) to establish calibration models. The calibration model for TA gave a coefficient of determination (R2) of 0.972 and the root mean square error of prediction (RMSEP) of 0.010% and for TSS the R2 was 0.801 and the RMSEP was 0.437oBx. The accuracies of these results indicate that NIR-HSI has potential for use in measuring TA and TSS of guavas.
关键词： calibration,prediction,model,nondestructive,near infrared
更新于2025-09-09 09:28:46
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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Cancellation Method of Signal Fluctuations in Brain Function Measurements Using Near-Infrared Spectroscopy
摘要： To estimate brain activity, it is important to improve the accuracy of brain function measurements by using near-infrared spectroscopy. The detection of signals is vital for correcting any disturbances or changes in the skin blood volume. We developed a cancellation method for brain probes placed on the scalp in the configuration of an equilateral triangle. In this configuration, 12 types of target signals were detected between the vertices, and 6 types of correction signals were detected between the vertices and the center of the triangle. We measured the changes in the blood volume resulting from the specific postural changes of the subject and applied the correction method using three calculation methods. The measured results showed that the correction signals were effective in reducing the disturbances. The correction was based on the cross-correlation coefficient and the amplitude ratio of signals.
关键词： near-infrared spectroscopy,cancellation method,brain function measurements,equilateral triangle configuration,cross-correlation coefficient,amplitude ratio
更新于2025-09-09 09:28:46
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Modeling Light Propagation through the Tissues of the Head Taking Account of Scattering Anisotropy to Optimize the Positioning of Irradiation Detectors and Sources in a Brain–Computer Interface Based on Near Infrared Spectroscopy
摘要： We describe here use of the Monte Carlo modeling method to specify the parameters of near infrared light propagation though the tissues of the head, which is needed for optimizing the operation of brain–computer interfaces. The studies used a four-layer spherical model of the head consisting of skin, bone, gray matter, and white matter. The relationship between the parameters of the radiation recorded and the distance between the source and detector were obtained.
关键词： foci of hemodynamic activity,near infrared spectrometry,brain–computer interface,Monte Carlo modeling
更新于2025-09-09 09:28:46
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Application of Biophotonics with Near Infrared Excitation for Theranostics; 近赤外励起バイオフォトニクスのセラノスティクスへの展開;
摘要： Near infrared wavelength region is known to have the most transparency of live body for electromagnetic wave with wavelength around the visible wavelength. Namely, the near infrared with a wavelength longer than 1000 nm (OTN-NIR) shows more transparency than that with shorter wavelength. The observation depth can be several centimeters with the OTN-NIR fluorescence, while that is limited to be only several millimeters with visible fluorescence. As OTN-NIR fluorescent agents, dyes, quantum dots, carbon nanotubes and rare-earth doped ceramic nanoparticles (RED-CNP) are known. A special feature of the RED-CNP is to show infrared-to-visible upconversion to emit visible light with a near infrared excitation, simultaneously with the OTN-NIR fluorescence. As a theranostic approach, nanomaterials for achieving photodynamic therapy with the near infrared excitation are introduced. Another special feature of the RED-CNP is the potential use for fluorescence nanothermometry. A scheme for ratiometric fluorescence nanothermometry with the OTN-NIR fluorescence is described. By using a RED-CNP with holomium and erbium co-doping, ratiometric fluorescence nanothermometry was successfully demonstrated. As shown with the case of photodynamic therapy with near infrared excitation, by applying an upconversion excitation scheme, visible light emission for photochemical reaction is possible with a near infrared excitation with high transparency in a live body. By constructing these multiple functions on the RED-CNP, various theranostic approach can be achieved. The size and bio distribution controls are important issues for applications of the RED-CNP for medical applications.
关键词： thermometry,near infrared,nanoparticle,rare-earth,PDT
更新于2025-09-09 09:28:46
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“Guide Star” Assisted Noninvasive Photoacoustic Measurement of Glucose
摘要： A novel “guide star” assisted photoacoustic (GSPA) method for noninvasive glucose measurement has been proposed. Instead of receiving PA signals that are directly generated by tissue, a virtual photodiode is employed to amplify the PA signal difference regarding amplitude and peak arrival time caused by glucose concentration variations in an indirect way. Being different from traditional PA spectroscopy, this method can improve sensitivity and accuracy by optimizing optical path lengths (or tissue thickness). On the other hand, being superior to near-infrared (NIR) spectroscopy, it utilizes both optical absorption and acoustic propagation velocity information offered by PA signals. Theoretical analysis and simulation have been done to illustrate how the concentration change affects the PA waveform. In vitro experiments on aqueous glucose solution were conducted with concentrations varying in human physiological range (50~350 mg/dL). Performance of quartz cuvettes with 1-mm and 2-mm optical path lengths were compared in terms of correlation quality (R2), degree of agreement (Bland-Altman plot) and clinical accuracy (Clarke’s Error Grid analysis) to demonstrate the scalability of sensitivity provided by the indirect method. Longer optical length shows better sensitivity and accuracy in this case. Moreover, detection was also done on human blood serum to further prove the potential of the proposed method for clinical application. Our proposed method provides solution to enhance sensitivity, facilitating development of portable and low-cost PA sensors with low power laser diodes for noninvasive glucose monitoring and other applications.
关键词： near-infrared,photoacoustics,virtual photodiode,noninvasive glucose monitoring,Diabetes Mellitus
更新于2025-09-09 09:28:46
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Sr2MgWO6:Cr3+ phosphors with effective near-infrared fluorescence and long-lasting phosphorescence
摘要： Cr3+-doped near-infrared (NIR) long-lasting phosphorescence (LLP) phosphors have drawn great attention for the promising application in unique bio-labels. Most of the studies are focused on gallate materials. Here we report a novel non-gallates NIR LLP phosphor Sr2MgWO6:Cr3+ that exhibit broadband emission at 700–1000 nm. X-ray powder diffraction, photoluminescence spectra, photoluminescence excitation spectra, LLP decay curves and thermoluminescence glow curves were determined to study the NIR LLP property and mechanism of Sr2MgWO6:Cr3+. Although Sr2MgWO6:0.4%Cr3+ gives the strongest NIR emission, the optimum content of Cr3+ in Sr2MgWO6 phosphor for LLP was 0.1%. Trap type and depth in Sr2MgWO6:Cr3+ were also discussed according to the thermoluminescence glow curves. Sr2MgWO6:Cr3+ phosphor is promising in optical information storage, night-vision surveillence, and in vivo bio-imaging.
关键词： long-lasting phosphorescence,Cr3+,Sr2MgWO6,near-infrared
更新于2025-09-09 09:28:46