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How qualitative spectral information can improve soil profile classification?
摘要： Soil classification is important to organize the knowledge of soil characteristics. Spectroscopy has increased in the last years as a technique for descriptive and quantitative evaluation of soils. Thus, our objective was to assess qualitative and quantitative methods on soil classification, based on model profiles. Soils in different environments in the Roraima state, Brazil, were evaluated and represented by 16 profiles, providing 109 soil samples, which were analyzed for particle size distribution, chemical attributes and spectral measurement. Visible-near infrared spectra (350–2500 nm) of soil samples were interpreted in terms of intensity, shape and features. The soil color obtained using a spectroradiometer and a colorimeter, and by a soil expert was compared. Descriptive and qualitative analyses were performed for all spectra of the soil profile samples. The descriptive evaluations of the spectral curves from all horizons of the same profile were used to identify the diagnostic attributes and assign a profile to a taxonomic class. This was possible because spectra of samples had specific shapes, features and intensities that combined to present a specific signature. The Outil Statistique d’Aide à la Cartogénèse Automatique and cluster quantitative analyses could not correctly group similar soil classes and they still need to be improved in order to extract all the variability of the spectral data to discriminate soil classes. Soil color quantification by the Munsell system using both equipments showed greater R2 and lower error than that achieved by a soil expert, due to influences of subjectivity inherent in human assessments. Based on this specific case, it was clear that the automatic system may be more consistent than the pedologist’s visual method. Future studies should focus on the development of an online tool that integrates a descriptive approach and spectral information of a given soil profile to determine its probable taxonomic class.
关键词： Munsell color system,soil classification,expert,NIR,colorimeter,spectroradiometer
更新于2025-09-23 15:22:29
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A Novel Multimodal NIR-II Nanoprobe for the Detection of Metastatic Lymph Nodes and Targeting Chemo-Photothermal Therapy in Oral Squamous Cell Carcinoma
摘要： Current surgical treatment for oral squamous cell carcinoma (OSCC) must be as precise as possible to fully resect tumors and preserve functional tissues. Thus, it is urgent to develop efficient fluorescent probes to clearly identify tumor delineation, as well as metastatic lymph nodes. Chemo-photothermal therapy combination attracted a growing attention to increase anti-tumor effect in various types of cancer, including OSCC. In the present study, we designed a multimodal NIR-II probe that involves combining photothermal therapy with chemotherapy, imaging OSCC tumors and detecting metastatic lymph nodes. Methods: In this study, we synthesized a novel near infrared (NIR)-II probe named TQTPA [4,4'-((6,7-bis(4-(hexyloxy)phenyl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl)bis(thiophene-5,2-diyl))bis(N,N-diphenylaniline)] via the Suzuki reaction and prepared multimodal nanoparticles (NPs) loading TQTPA and cis-dichlorodiammine platinum (CDDP) (HT@CDDP) by hyaluronic acid. The characteristics of the NPs, including their photothermal and imaging capabilities were investigated in vitro and in vivo. Their anti-tumor efficacy was evaluated using orthotopic, tongue tumor-bearing, nude mice. Results: The NPs possessed good stability and water solubility and were pH/hyaluronidase sensitive. The good tissue penetration quality and active targeting ability enabled the NPs to draw the outline of orthotopic tongue tumors and metastatic lymph nodes as small as 1 mm in nude mice by IR-808 under NIR exposure. In vitro and in vivo experiments validated the biocompatibility and low systematic toxicity of the NPs. At the same time, the NPs acted as multimodal therapy agents, combining photothermal therapy with chemotherapy. Conclusion: With a good imaging capability and anti-tumor efficacy, our NPs successfully outlined orthotopic tongue tumors and metastatic lymph nodes as well as enabled chemo-photothermal therapy combination. Our study established a solid foundation for the application of new clinical diagnosis and treatment patterns in the future.
关键词： NIR-II imaging,metastatic lymph node detection,chemo-photothermal therapy,active targeting
更新于2025-09-23 15:22:29
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A New Generation of NIR-II Probes: Lanthanide-Based Nanocrystals for Bioimaging and Biosensing
摘要： Fluorescence-based imaging in the second near infrared window (NIR-II, 1000–1700 nm) is extensively used in both fundamental scientific research and clinical practice, owing to its advances of high sensitivity and high spatiotemporal resolution with increasing tissue penetration depths. Among several NIR-II fluorophores, recent accomplishments in biocompatible lanthanide-based luminescent nanomaterials have aroused great interest of researchers. This progress report summarizes recent progress in controlled synthesis of lanthanide-based NIR-II nanomaterials and their state-of-the-art in NIR-II biomedical imaging and biosensing applications. In addition, challenges and opportunities for this kind of novel NIR-II nanoprobes are also discussed.
关键词： lanthanides,bioimaging,NIR-II,near infrared imaging,fluorescence,nanoparticles
更新于2025-09-23 15:22:29
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NIR Emission Nanoparticles Based on FRET Composed of AIE Luminogens and NIR Dyes for Two-photon Fluorescence Imaging
摘要： Near-infrared (NIR) nanoparticles (NPs) based on fluorescence resonance energy transfer (FRET) were prepared by co-encapsulation of a red aggregation-induced emission (AIE) molecule, 2-(4-bromophenyl)-3-(4-(4-(diphenylamino)styryl)phenyl)fumaronitrile (TB), and a commercial NIR fluorescence dye, silicon 2,3-naphthalocyanine bis(trihexylsilyloxide) (NIR775) with an amphiphilic polymer poly(styrene-co-maleic anhydride) (PSMA). The surface of the NPs, PSMA@TB/NIR775, was modified with poly(ethylene glycol) (PEG) to increase the in vivo biocompatibility of the NPs. The PSMA@TB/NIR775 NPs showed a strong NIR (780 nm) narrow emission and excellent two-photon absorption property. Moreover, the NPs exhibited good monodispersity, stability, and low cytotoxicity. Under the excitation of a 1040 nm femtosecond (fs) laser, the emission peaks at 680 nm of TB and 780 nm of NIR775 excited by FRET were obtained. We utilized PSMA@TB/NIR775 NPs as fluorescent contrast agents for two-photon excited NIR microscopic imaging, and good NIR imaging effect of mouse brain vasculature was obtained with the imaging depth of about 150 μm. The FRET strategy by co-encapsulating AIE molecule and NIR dye will be helpful in preparing more narrow emission NIR probes for deep-tissue biological imaging.
关键词： Two-photon imaging,FRET,NIR emission,AIE,Amphiphilic polymer
更新于2025-09-23 15:22:29
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Rapid screening of ochratoxin A in wheat by infrared spectroscopy
摘要： The use of infrared spectroscopy for the screening of 229 unprocessed durum wheat samples naturally contaminated with OTA has been investigated. Samples were analysed by both Fourier Transform near- and mid-infrared spectroscopy (FT-NIR, FT-MIR). Partial-Least Squares-Discriminant Analysis (PLS-DA) and Principal Component-Linear Discriminant Analysis (PC-LDA) classification models were used to differentiate highly contaminated durum wheat samples from low contaminated ones and the performances of the resulting models were compared. The overall discrimination rates were higher than 94% for both FT-NIR and FT-MIR range by using a cut-off limit set at 2 μg/kg OTA, independently from the classification model used thus confirming the reliability of the two statistical approaches used. False compliant rates of 6% were obtained for both spectral ranges and both classification models. These findings indicate that FT-NIR, as well as FT-MIR analysis, might be a promising, inexpensive and easy-to-use screening tool to rapidly discriminate unprocessed wheat samples for OTA content.
关键词： Principal component analysis,Screening method,Ochratoxin A,Unprocessed wheat,FT-NIR/MIR spectroscopy,Linear discriminant analysis
更新于2025-09-23 15:22:29
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A novel NIR-emissive probe with large Stokes shift for hypochlorite detection and imaging in living cells
摘要： Due to the importance of hypochlorite (ClO-) in the process of life, a near-infrared region (NIR) emissive probe (DCPO-DMTC) with large Stokes shift was synthesized for the selective detection of hypochlorite. This probe detects exogenous and endogenous hypochlorite via "oxidative deprotection" of dimethylthiocarbamate-protected phenolic hydroxyl groups. The response was monitored by time-course UV–Vis and fluorescent spectroscopy. The emission response of the probe to ClO? presented a good linear relationship in the 0–100 μM concentration range, and the LOD of this probe was 164 nM. The probe was used to successfully visualize endogenous ClO- generation in RAW 246.7 cells under external stimulation.
关键词： NIR-emissive,Large Stokes-shift,Hypochlorite,Bioimaging
更新于2025-09-23 15:22:29
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Ultrathin Tellurium Oxide/Ammonium Tungsten Bronze Nanoribbon for Multi-Modality Imaging and Second Near-Infrared Region Photothermal Therapy
摘要： Developing nano-photothermal agents (PTAs) with satisfied photothermal conversion efficiency (PTCE) in the second NIR window (1000-1350 nm, NIR II) holds great promise for enhanced photothermal therapy (PTT) effect. Herein, we develop a NIR-II PTA with advanced PTCE, based on a new two-dimensional (2D) ultrathin tellurium oxide/ammonium tungsten bronze (TeO2/(NH4)xWO3) nanoribbons (TONW NRs). The doped ammonia ions mediated-free electrons injection into the LUMO band of WO3 combined with the electronic transitions between W6+ ions and the lone pair of electrons in Te atoms achieve excellent NIR absorption of TONW NRs resulted from localized surface plasmon resonance (LSPR). The polyethylene glycol functionalized TONW NRs (PEG-TONW NRs) exhibit good stability and biocompatibility, displaying a PTCE high to 43.6%, surpassing many previous nano-PTAs active in the NIR II region, leading to remarkable tumor ablation ability both in vitro and in vivo. Meanwhile, advanced X-ray computed tomography (CT) and photoacoustic (PA) imaging capability of PEG-TONW NRs were also realized. Given the admirable photothermal effect in NIR II region, good biocompatibility and advanced CT/PA imaging diagnosis capability, the novel PEG-TONW NRs is promising in future personalized medicine application.
关键词： photothermal therapy,multimodal imaging,tellurium oxide,two-dimensional nanomaterials,ammonium tungsten bronze,the second NIR window
更新于2025-09-23 15:22:29
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Near-Infrared Light Triggered Sulfur Dioxide Gas Therapy of Cancer
摘要： The exploitation of gas therapy platforms holds great promise as a 'green' approach for selective cancer therapy, however, it is often associated with some challenges, such as uncontrolled or insufficient gas generation and unclear therapeutic mechanisms. In this work, a gas therapy approach based on near-infrared (NIR) light triggered sulfur dioxide (SO2) generation was developed, and the therapeutic mechanism as well as in vivo anti-tumor therapeutic efficacy was demonstrated. A SO2 prodrug-loaded rattle-structured upconversion@silica nanoparticles (RUCSNs) was constructed to enable high loading capacity without obvious leakage, and to convert NIR light into ultraviolet (UV) light so as to activate the prodrug for SO2 generation. In addition, SO2 prodrug-loaded RUCSNs showed high cell uptake, good biocompatibility, intracellular tracking ability, and high NIR light triggered cytotoxicity. Furthermore, the cytotoxic SO2 was found to induce cell apoptosis accompanied with the increase of intracellular reactive oxygen species (ROS) levels and the damage of nuclear DNA. Moreover, efficient inhibition of tumor growth was achieved, associated with significantly prolonged survival of mice. Such NIR light-triggered SO2 therapy may provide an effective strategy to stimulate further development of synergistic cancer therapy platforms.
关键词： upconversion nanoparticles (UCNPs),gas therapy,cancer therapy,near-infrared (NIR),sulfur dioxide (SO2)
更新于2025-09-23 15:22:29
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Comparison of Different Types of Near Infrared (NIR) Instruments in Ability to Measure Alkaloids in Capsule of Poppy (P. somniferum)
摘要： The poppy capsule is one of the most important raw materials for the pharmaceuticals industry containing in about 25 different alkaloids. Among these there are important substances, such as morphine, with analgesic and anaesthetic properties, anti-tussive codeine, and noscapine with anti-tumor activity. My first objective was comparing dispersive and Fourier transformed (FT) near-infrared (NIR) instruments in order to measure alkaloids using the same sample population via mathematical pre-treatments (i.e. gap-segment derivatives) of the spectra and partial least squares (PLS) calibrations. The best PLS calibration using cross validation (CV) was for morphine based on derivative spectra of dispersive NIR with R-square (R2) 0.924 and root mean square error (RMSE) 1.198 mg (g dry matter)–1 in 1.24–20.44 mg (g dry matter)–1 range. Comparison of the changes in the output of the PLS parameter for the two instruments revealed a variance depending on the derivative and the segment size.
关键词： NIR,alkaloids,poppy capsule,PCA
更新于2025-09-23 15:22:29
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Counter Anion Effect on the Photophysical Properties of Emissive Indolizine-Cyanine Dyes in Solution and Solid State
摘要： Near-infrared emissive materials with tunable Stokes shifts and solid-state emissions are needed for several active research areas and applications. To aid in addressing this need, a series of indolizine-cyanine compounds varying only the anions based on size, dipole, and hydrophilicity were prepared. The effect of the non-covalently bound anions on the absorption and emission properties of identical π-system indolizine-cyanine compounds were measured in solution and as thin films. Interestingly, the anion choice has a significant influence on the Stokes shift and molar absorptivities of the dyes in solution. In the solid-state, the anion choice was found to have an effect on the formation of aggregate states with higher energy absorptions than the parent monomer compound. The dyes were found to be emissive in the NIR region, with emissions peaking at near 900 nm for specific solvent and anion selections.
关键词： solid-state emission,optical materials,NIR emissive materials,indolizine cyanine,stokes shift
更新于2025-09-23 15:22:29