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Spectral Imaging Technology - A Review on Skin and Endoscopy Applications
摘要： Spectral imaging technology is an emerging modality that combines the advantages of both imaging and spectroscopy (high spatial and spectral resolution) in one device. The technology has potential in numerous medical imaging and diagnostic applications. In this review, we describe the techniques used to acquire spectral images and the methods used for analyzing spectral images. We then provide detailed review about the progress of the spectral imaging technology in skin and endoscopy applications. This review also covers the recent patents on spectral imaging devices, methods, and data analysis algorithms.
关键词： optical scattering,spectroscopy,Endoscopy,spectral imaging,tissue reflectance,skin diagnosis,medical diagnosis,optical absorption
更新于2025-09-10 09:29:36
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Analysis of nervous fiber, muscle, and blood vessels using their ulraviolet near infrared reflectance characteristics
摘要： Injury to the nervous system can lead to irreversible problems as nervous tissues have limited regenerative capability. Therefore it is imperative to find an objective, reliable, cheap, and easy-to-apply method that separates nervous fibers from muscles and blood vessels. The aim of this study is to determine structural differences that can aid in easy and reliable identification of nervous fibers. We analyzed light reflectance from these tissues from 230 nm to 1000 nm and found that in the range of 400 nm-600 nm nervous fibers have higher reflectance in comparison to others. Therefore, we generated distinct features in this range and utilized support vector machine to automatically classify samples. Classification performance demonstrated that light reflectance is a good candidate feature that can help to classify nervous tissue.
关键词： surgery,support vector machines,light reflectance,Nervous tissue
更新于2025-09-10 09:29:36
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Reflectance confocal microscopy features of labial melanotic macule: Report of three cases
摘要： The term labial melanotic macule of the lips (MML) is used to describe a flat-pigmented lesion on the vermilion border, with an estimated prevalence of up to 3% of the population. Most MMLs are located on the lower lip and are more common in female patients. MMLs are mostly associated with hyperpigmentation of the basal keratinocytes with normal to a slightly increased density of melanocytes; an infiltrate of melanophages in the superficial dermis can also contribute to the pigmented appearance of MMLs. These benign lesions may raise concern for melanoma or may be confused with other labial pigmentary disorders. Dermoscopy is widely used for the diagnosis of pigmented and nonpigmented lesions on the skin. Reflectance confocal microscopy (RCM) is an in vivo, noninvasive imaging technique that allows horizontal optical sectioning of skin at cellular-level resolution, from the surface to a depth of about 200 μm. Although the lips are amenable for hand-held RCM examination, publications about the RCM findings in MMLs are limited. To improve the recognition of MML under RCM, we report on 3 cases of biopsy-proven MMLs.
关键词： dermoscopy,labial melanotic macule,reflectance confocal microscopy
更新于2025-09-10 09:29:36
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Optical and Electrical Characterization of Pure PMMA for Terahertz Wide-band Metamaterial Absorbers
摘要： The characteristics of relative permittivity and reflectance for poly (methyl methacrylate) (PMMA) films prepared by spin-coating were investigated and an excellent wideband terahertz (THz) metamaterial absorber (MA) had been fabricated by employing PMMA film as the dielectric layer. XRD and AFM indicated that all the PMMA films with thicknesses from 11 to 17 μm were amorphous and extremely smooth with roughness about 0.203 nm. Raman results demonstrated that vibration strength of the same covalent bonds tends to be consistent with an increase in film thickness. The dual beam laser interferometer (DBLI) was employed to study the influence of applied frequency and thickness on the relative permittivity, and the results exhibited dielectric constants increased from 2.88 to 4.04 with the thickness increasing from 9 to 14 μm. And the dielectric constants for PMMA films with a certain thickness (8 μm) gradually declined when the applied frequency increased from 100 to 105 Hz; besides, the dielectric constant in THz band was forecasted approximately 2.5. The terahertz time domain spectrometer (THz-TDS) results revealed that the THz reflectance was of gradual degradation from 80 to 58% at 3.2 THz, as the thickness increased from 11 to 17 μm. In addition, the UV-VIS spectrum showed that thickness had little effect on reflectance and transmittance in visible region, leading to the almost same Eg (energy gap) about 3.7 eV. At last, by employing PMMA film as the dielectric layer, a highly wideband metamaterial absorber with absorption > 80% from 4.1 to 7.4 THz was fabricated.
关键词： Terahertz,Metamaterial absorber,PMMA,Reflectance,Permittivity
更新于2025-09-10 09:29:36
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Rapid and sensitive label-free determination of aflatoxin M1 levels in milk through a White Light Reflectance Spectroscopy immunosensor
摘要： Α miniaturized optical immunosensor based on White Light Reflectance Spectroscopy (WLRS) for the rapid and label-free detection of aflatoxin M1 (AFM1) in milk samples has been developed. WLRS sensing system consists of the measurement set-up and the biochip. The first encompasses the reflection probe, the light source and the spectrometer, while the latter is a Si chip with a SiO2 layer on top where an AFM1-bovine serum albumin conjugate has been immobilized. The assay was performed by running mixtures of rabbit polyclonal anti-AFM1 antibody with the calibrators or the samples, followed by reaction with biotinylated anti-rabbit IgG antibody and streptavidin. The assay cycle was completed in 25 min, the limit of detection was 6 pg/mL, and the linear working range extended from 0.012 to 2.0 ng/mL. The assay was repeatable (intra-and inter-assay coefficients of variation ranged from 2.1 to 6.3% and 3.5 to 8.2%, respectively) and accurate (percent recovery values ranged from 92.5 to 110%). AFM1 could be detected with the immunosensor developed in both processed and unprocessed milk of different animal species without any dilution. The excellent analytical characteristics and the small instrument size make the proposed sensor suitable for accurate low-cost AFM1 determination in milk samples at the point-of-need.
关键词： Aflatoxin M1,Immunosensor,Milk,White Light Reflectance Spectroscopy
更新于2025-09-10 09:29:36
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Application of visible-near infrared spectroscopy to evaluate the quality of button mushrooms
摘要： The Agaricus bisporus mushroom is one of the most cultivated and consumed mushrooms in the world, thanks to its delicacy, nutritional value and flavour. The quality evaluation of the A. bisporus during the harvest is generally established by a visual check by trained operators. This method complies with the request of the Distribution Channel (DC) to retailers and guarantees very low physical damage to the mushrooms; nevertheless, it is subjective and it does not guarantee the highest quality standard for the consumer. The aim of this study was to test the use of visible/near infrared (vis/NIR) reflectance spectroscopy (400–1000 nm) to objectively evaluate the quality parameters of A. bisporus mushrooms. A total of 167 samples of A. bisporus mushrooms were harvested according to the main DC purchasing standards. The vis/NIR analyses were performed the day of sampling just before the physico-chemical analyses (sizes, firmness, soluble solids content and moisture content) used as reference quality parameters. The vis/NIR spectra were correlated to reference measures in order to build predictive models using the partial least squares regression method. Calculated models gave positive results regarding the prediction of the moisture content (r2 (pred) ? 0.78) and firmness (r2 (pred) ? 0.78). Results of this explorative study could be considered encouraging and demonstrate the applicability of vis/NIR spectroscopy on A. bisporus as a rapid technique (i) to monitor the productive process directly at the company, (ii) to standardize the harvest moment, and (iii) to support DC’s buyers’ choices, nowadays exclusively based on product external characteristics.
关键词： quality,vis/NIR spectroscopy,harvest,reflectance,mushrooms,distribution channel
更新于2025-09-10 09:29:36
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Reflectance spectra characteristics from an SPR grating fabricated by nano-imprint lithography technique for biochemical nanosensor applications
摘要： In this paper, we report our research work on developing a Surface Plasmon Resonance (SPR) element with sub-micron (hundreds of nanometers) periodicity grating structure. This grating structure was fabricated by using a simple nano-imprint lithography technique from an organically siloxane polymers, which was then covered by nanometer thin gold layer. The formed grating structure was a very well defined square-shaped periodic structure. The measured reflectance spectra indicate the SPR wave excitation on this grating structure. For comparison, the simulations of reflectance spectra have been also carried out by using Rigorous Coupled-Wave Analysis (RCWA) method. The experimental results are in very good agreement with the simulation results.
关键词： biochemical nanosensor,SPR,grating,nano-imprint lithography,reflectance spectra
更新于2025-09-10 09:29:36
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Rock-salt CdZnO as a transparent conductive oxide
摘要： Transparent conducting oxides (TCOs) are widely used in applications from solar cells to light emitting diodes. Here, we show that the metal organic chemical vapor deposition (MOCVD)-grown, rock-salt CdZnO ternary, has excellent potential as a TCO. To assess this compound, we use a combination of infrared reflectance and ultraviolet-visible absorption spectroscopies, together with Hall effect, to determine its optical and electrical transport characteristics. It is found that the incorporation of Zn produces an increment of the electron concentration and mobility, yielding lower resistivities than those of CdO, with a minimum of 1:96 (cid:2) 10(cid:3)4 X (cid:4) cm for a Zn content of 10%. Moreover, due to a combination of increasing bandgap energy and band filling, the absorption band-edge energy increases from 2.58 eV in CdO up to 2.89 eV for 15% Zn, yielding a largely enhanced transparency in the visible. The low required growth temperatures, together with the scalability of CVD deposition, provide an excellent ground for the integration of this TCO ternary alloy on foreign devices.
关键词： Hall effect,ultraviolet-visible absorption,MOCVD,infrared reflectance,CdZnO,Transparent conducting oxides
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Radiometric Performance of Multispectral Camera Applied to Operational Precision Agriculture
摘要： The use of multispectral sensors onboard of unmanned vehicles is nowadays a common practice in precision agriculture. Their radiometric behavior is an important issue to ensure comparable information along space and time. A calibration of a Sequoia? camera is conducted in terms of reflectance and NDVI, taking benefit from a wheat cover field work. The output reflectance values in the green and red channel show linear behavior in the range of 0.00 to 0.45, with a saturation over this value. The red edge and NIR channels show linear behavior in the whole reflectance range, with better performance in the NIR than in the red-edge channel. The NDVI has a good agreement with field measurements, near the 1:1 line, showing the highest variability for the lower values due to heterogeneity of soil brightness linked to variations in soil moisture.
关键词： NDVI,Reflectance,Multispectral Camera,Radiometric Calibration
更新于2025-09-09 09:28:46
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Comprehensive Remote Sensing || Forest Background
摘要： Forest background (understory) is an important component of forest ecosystems typically supporting the majority of total ecosystem floristic diversity (Gilliam and Roberts, 2003; D’Amato et al., 2009). Forest background plays a central role in the dynamics and functioning of forest ecosystems by (i) influencing long-term successional patterns (Hart and Chen, 2006; Nyland et al., 2006); (ii) facilitating nutrient cycling and energy flow as ecosystem drivers (Chapin, 1983; Chastain et al., 2006); (iii) providing sources of food and habitat for wildlife species/animals (Tuanmu et al., 2010); and (iv) affecting forest fire danger and fire behavior in the event of fire occurrences (Pereira et al., 2004; Soares-Filho et al., 2012). Understanding forest understory vegetation ecology has important implications for both conservation and production-oriented forest management. Overall evidence is emerging that the type of forest background/understory vegetation present has important economic implications (Nilsson and Wardle, 2005).
关键词： phenology,reflectance,understory,LiDAR,remote sensing,Forest background
更新于2025-09-09 09:28:46