Fresnel incoherent correlation holography(FINCH) is a unique three-dimensional(3D) imaging technique which has the advantages of scanning-free,high resolution,and easy matching with existing mature optical systems.In ...Fresnel incoherent correlation holography(FINCH) is a unique three-dimensional(3D) imaging technique which has the advantages of scanning-free,high resolution,and easy matching with existing mature optical systems.In this article,an incoherent digital holographic spectral imaging method with high accuracy of spectral reconstruction based on liquid crystal tunable filter(LCTF) and FINCH is proposed.Using the programmable characteristics of spatial light modulator(SLM),a series of phase masks,none of whose focal lengths changes with wavelength,is designed and made.For each wavelength of LCTF output,SLM calls three phase masks with different phase constants at the corresponding wavelength,and CCD records three holograms.The spectral images obtained by this method have a constant magnification,which can achieve pixel-level image registration,restrain image registration errors,and improve spectral reconstruction accuracy.The results show that this method can not only obtain the 3D spatial information and spectral information of the object simultaneously,but also have high accuracy of spectral reconstruction and excellent color reproducibility.展开更多
Traditional Chinese medicine(TCM)is a treasure of the Chinese nation,providing effective solutions to current medical requisites.Various spectral techniques are undergoing continuous development and provide new and re...Traditional Chinese medicine(TCM)is a treasure of the Chinese nation,providing effective solutions to current medical requisites.Various spectral techniques are undergoing continuous development and provide new and reliable means for evaluating the efficacy and quality of TCM.Because spectral techniques are noninvasive,convenient,and sensitive,they have been widely applied to in vitro and in vivo TCM evaluation systems.In this paper,previous achievements and current progress in the research on spectral technologies(including fluorescence spectroscopy,photoacoustic imaging,infrared thermal imaging,laser-induced breakdown spectroscopy,hyperspectral imaging,and surface enhanced Raman spectroscopy)are discussed.The advantages and disadvantages of each technology are also presented.Moreover,the future applications of spectral imaging to identify the origins,components,and pesticide residues of TCM in vitro are elucidated.Subsequently,the evaluation of the efficacy of TCM in vivo is presented.Identifying future applications of spectral imaging is anticipated to promote medical research as well as scientific and technological explorations.展开更多
Multi-channel polarization optical technology is increasingly used for prompt monitoring of water systems.Optical devices during the assessment of water quality determine the intensity of light through the studied aqu...Multi-channel polarization optical technology is increasingly used for prompt monitoring of water systems.Optical devices during the assessment of water quality determine the intensity of light through the studied aquatic environment.Spectrophotometric devices measure the spectrum of weakening of light through the aquatic environment.Spectroellipsometric devices receive spectra in vertical and horizontal polarizations.The presented article develops an adaptive optical hardware and image system for monitoring water bodies.The system is combined.It consists of 2 parts:1)automated spectrophotometer-refractometer,and 2)adaptive spectroellipsometer.The system is equipped with a corresponding algorithmic and software,including algorithms for identifying spectral curves,databases and knowledge of spectral curves algorithms for solving reverse problems.The presented system is original since it differs from modern foreign systems by a new method of spectrophotometric and spectroellipsometric measurements,an original elemental base of polarization optics and a comprehensive mathematical approach to assessing the quality of a water body.There are no rotating polarization elements in the system.Therefore,this makes it possible to increase the signal-to-noise ratio and,as a result,improve measurement stability and simplify multichannel spectrophotometers and spectroellipsometers.The proposed system can be used in various water systems where it is necessary to assess water quality or identify the presence of a certain set of chemical elements.展开更多
Authentication of pasta is currently determined using molecular biology-based techniques focusing on DNA as the target analyte. Whilst proven to be effective, these approaches can be criticised as being destructive, t...Authentication of pasta is currently determined using molecular biology-based techniques focusing on DNA as the target analyte. Whilst proven to be effective, these approaches can be criticised as being destructive, time consuming, and requiring specialist instrument training. Advances in the field of multispectral imaging (MSI) and hyperspectral imaging (HSI) have facilitated the development of compact imaging platforms with the capability to rapidly differentiate a range of materials (inclusive of grains and seeds) based on surface colour, texture and chemical composition. This preliminary investigation evaluated the applicability of spectral imaging for identification and quantitation of durum wheat grain samples in relation to pasta authenticity. MSI and HSI were capable of rapidly distinguishing between durum wheat and adulterant common wheat cultivars and assigning percentage adulteration levels characterised by low biases and good repeatability estimates. The results demonstrated the potential for spectral imaging based seed/grain adulteration testing to augment existing standard molecular approaches for food authenticity testing.展开更多
The problem of in vrivo photoluminescence diagnostics of the tissues acessible by endoscopes is discussed.The spectral imaging module attachable to conventional rigid and flexible medical endoscopes is developed and d...The problem of in vrivo photoluminescence diagnostics of the tissues acessible by endoscopes is discussed.The spectral imaging module attachable to conventional rigid and flexible medical endoscopes is developed and described.It is based on a double acousto-optical tunable filter(AOTF)and a specialized optical coupling system.The module provides wide field of view(FOV),absence of image distortions,random spectral access,fast spectral image acquisition at any wavelength in the visible range and accurate measurement of reflectance spectrum in each pixel of the image.Images of typical biomedical samples are presented and discussed.Their spectra are compared to the reference data.展开更多
The application to detect ilally added drugs in dietary supplerments by near-infrared spectral imaging was studied with the focus on nifedipine,diclofenac and metformin.The method is based on near-infrared spectral im...The application to detect ilally added drugs in dietary supplerments by near-infrared spectral imaging was studied with the focus on nifedipine,diclofenac and metformin.The method is based on near-infrared spectral images correlation cofficient to detect ilally added drugs.The results comply 100%with HPLC methods test results with no false positive results.展开更多
An introduction to the basics of spectral imaging as applied to biological tissues is presented.An example of a spectral image of a face is used to demonstrate the data and spectral analysis that specify the melanin c...An introduction to the basics of spectral imaging as applied to biological tissues is presented.An example of a spectral image of a face is used to demonstrate the data and spectral analysis that specify the melanin content(M),blood content(B),tissue oxygen saturation(S),water content(W),fraction of scattering due to Rayleigh scattering(f)and due to Mie scattering(1−f),and the reduced scattering coefficient at 500-nm wavelength(µs 500 nm).The sensitivity of reflectance spectra to variation in the various parameters is illustrated.展开更多
We have examined ten human subjects with a previously developed instrument for near-infrared diffuse spectral imaging of the female breast.The instrument is based on a tandem,planar scan of two collinear optical fiber...We have examined ten human subjects with a previously developed instrument for near-infrared diffuse spectral imaging of the female breast.The instrument is based on a tandem,planar scan of two collinear optical fibers(one for illumination and one for collection)to image a gently compressed breast in a transmission geometry.The optical data collection features a spatial sampling of 25 points/cm2 over the whole breast,and a spectral sampling of 2 points/nm in the 650-900nm wavelength range.Of the ten human subjects examined,eight are healthy subjects and two are cancer patients with unilateral invasive ductal carcinoma and ductal carcinoma in situ,respectively.For each subject,we generate second-derivative images that identify a network of highly absorbing structures in the breast that we assign to blood vessels.A previously developed paired-wavelength spectral method assigns oxygenation values to the absorbing structures displayed in the second-derivative images.The resulting oxygenation images feature average values over the whole breast that are significantly lower in cancerous breasts(69±14%,n=2)than in healthy breasts(85±7%,n=18)(p<0.01).Furthermore,in the two patients with breast cancer,the average oxygenation values in the cancerous regions are also significantly lower than in the remainder of the breast(invasive ductal carcinoma:49±11%vs 61±16%,p<0.01;ductal carcinoma in situ:58±8%vs 77±11%,p<0.001).展开更多
The content of berberine hydrochloride(BH)in compound berberine tablets(CBTs)is subject to strict requirements.Its content is usually measured based on chemical analysis.In this paper,the fluorescence spectral imaging...The content of berberine hydrochloride(BH)in compound berberine tablets(CBTs)is subject to strict requirements.Its content is usually measured based on chemical analysis.In this paper,the fluorescence spectral imaging method was used to study the relative content of BH from a physics perspective.By comparing the relative fluorescence intensity of self-made CBTs with di®erent mass percentages of BH,a linear positive relationship was observed between the BH content and the relative fluorescence intensity,and accordingly the quality of CBTs of different brands was evaluated.The results indicate that the fluorescence spectral imaging method can be a simple,fast and nondestructive semi-quantitative analysis method to determine the content of BH in CBTs,and this method has great potential in the quality control of CBTs.展开更多
Skin scar is unique to humans,the major significant negative outcome sustained after thermal injuries,traumatic injuries,and surgical procedures.Hypertrophic scar in human skin is investigated using non-linear spectra...Skin scar is unique to humans,the major significant negative outcome sustained after thermal injuries,traumatic injuries,and surgical procedures.Hypertrophic scar in human skin is investigated using non-linear spectral imaging microscopy.The high contrast images and spectroscopic intensities of collagen and elastic fibers extracted from the spectral imaging of normal skin tissue,and the normal skin near and far away from the hypertrophic scar tissues in a 10-year-old patient case are obtained.The results show that there are apparent differences in the morphological structure and spectral characteristics of collagen and elastic fibers when comparing the normal skin with the hypertrophic scar tissue.These differences can be good indicators to differentiate the normal skin and hypertrophic scar tissue and demonstrate that non-linear spectral imaging microscopy has potential to noninvasively investigate the pathophysiology of human hypertrophic scar.展开更多
Neural network analysis based on Growing Hierarchical Self-Organizing Map (GHSOM) is used to examine Spatial-Temporal characteristics in Aerosol Optical Depth (AOD), Ångström Exponent (ÅE)...Neural network analysis based on Growing Hierarchical Self-Organizing Map (GHSOM) is used to examine Spatial-Temporal characteristics in Aerosol Optical Depth (AOD), Ångström Exponent (ÅE) and Precipitation Rate (PR) over selected East African sites from 2000 to 2014. The selected sites of study are Nairobi (1°S, 36°E), Mbita (0°S, 34°E), Mau Forest (0.0° - 0.6°S;35.1°E - 35.7°E), Malindi (2°S, 40°E), Mount Kilimanjaro (3°S, 37°E) and Kampala (0°N, 32.1°E). GHSOM analysis reveals a marked spatial variability in AOD and ÅE that is associated to changing PR, urban heat islands, diffusion, direct emission, hygroscopic growth and their scavenging from the atmosphere specific to each site. Furthermore, spatial variability in AOD, ÅE and PR is distinct since each variable corresponds to a unique level of classification. On the other hand, GHSOM algorithm efficiently discriminated by means of clustering between AOD, ÅE and PR during Long and Short rain spells and dry spell over each variable emphasizing their temporal evolution. The utilization of GHSOM therefore confirms the fact that regional aerosol characteristics are highly variable be it spatially or temporally and as well modulated by PR received over each variable.展开更多
Beneting from the developments of advanced optical microscopy techniques,the mysteries of biological functions at the cellular and subcellular levels have been continuously revealed.Stimulated Raman scattering(SRS)mic...Beneting from the developments of advanced optical microscopy techniques,the mysteries of biological functions at the cellular and subcellular levels have been continuously revealed.Stimulated Raman scattering(SRS)microscopy is a rapidly growing technique that has attracted broad attentions and become a powerful tool for biology and biomedicine,largely thanks to its chemical specicity,high sensitivity and fast image speed.This review paper introduces the principles of SRS,discusses the technical developments and implementations of SRS microscopy,then highlights and summarizes its applications on biological cellular machinery andnally shares our visions of potential breakthroughs in the future.展开更多
Sustainable forest management is essential to confront the detrimental impacts of diseases on forest ecosystems.This review highlights the potential of vegetation spectroscopy in improving the feasibility of assessing...Sustainable forest management is essential to confront the detrimental impacts of diseases on forest ecosystems.This review highlights the potential of vegetation spectroscopy in improving the feasibility of assessing forest disturbances induced by diseases in a timely and cost-effective manner.The basic concepts of vegetation spectroscopy and its application in phytopathology are first outlined then the literature on the topic is discussed.Using several optical sensors from leaf to landscape-level,a number of forest diseases characterized by variable pathogenic processes have been detected,identified and quantified in many country sites worldwide.Overall,these reviewed studies have pointed out the green and red regions of the visible spectrum,the red-edge and the early near-infrared as the spectral regions most sensitive to the disease development as they are mostly related to chlorophyll changes and symptom development.Late disease conditions particularly affect the shortwave-infrared region,mostly related to water content.This review also highlights some major issues to be addressed such as the need to explore other major forest diseases and geographic areas,to further develop hyperspectral sensors for early detection and discrimination of forest disturbances,to improve devices for remote sensing,to implement longterm monitoring,and to advance algorithms for exploitation of spectral data.Achieving of these goals will enhance the capability of vegetation spectroscopy in early detection of forest stress and in managing forest diseases.展开更多
Spectral imaging extends the concept of traditional color cameras to capture images across multiple spectral channels and has broad ap-plication prospects.Conventional spectral cameras based on scanning methods suffer...Spectral imaging extends the concept of traditional color cameras to capture images across multiple spectral channels and has broad ap-plication prospects.Conventional spectral cameras based on scanning methods suffer from the drawbacks of low acquisition speed and large volume.On-chip computational spectral imaging based on metasur-face filters provides a promising scheme for portable applications,but endures long computation time due to point-by-point iterative spec-tral reconstruction and mosaic effect in the reconstructed spectral im-ages.In this study,on-chip rapid spectral imaging was demonstrated,which eliminated the mosaic effect in the spectral image by deep-learning-based spectral data cube reconstruction.The experimental results show that 4 orders of magnitude faster than the iterative spec-tral reconstruction were achieved,and the fidelity of the spectral re-construction for the standard color plate was over 99%for a standard color board.In particular,video-rate spectral imaging was demon-strated for moving objects and outdoor driving scenes with good per-formance for recognizing metamerism,where the concolorous sky and white cars can be distinguished via their spectra,showing great po-tential for autonomous driving and other practical applications in the field of intelligent perception.展开更多
AIM: To evaluate whether virtual chromoendoscopy can improve the delineation of small bowel lesions previously detected by conventional white light small bowel capsule endoscopy(SBCE). METHODS: Retrospective single ce...AIM: To evaluate whether virtual chromoendoscopy can improve the delineation of small bowel lesions previously detected by conventional white light small bowel capsule endoscopy(SBCE). METHODS: Retrospective single center study. One hundred lesions selected from forty-nine consecutive conventional white light SBCE(SBCE-WL) examinations were included. Lesions were reviewed at three Flexible Spectral Imaging Color Enhancement(FICE) settings and Blue Filter(BF) by two gastroenterologists with ex-perience in SBCE, blinded to each other's findings, whoranked the quality of delineation as better, equivalent or worse than conventional SBCE-WL. Inter-observer percentage of agreement was determined and analyzed with Fleiss Kappa(k) coefficient. Lesions selected for the study included angioectasias(n = 39), ulcers/ero-sions(n = 49) and villous edema/atrophy(n = 12). RESULTS: Overall, the delineation of lesions was im-proved in 77% of cases with FICE 1, 74% with FICE 2, 41% with FICE 3 and 39% with the BF, with a percent-age of agreement between investigators of 89%(k = 0.833), 85%(k = 0.764), 66%(k = 0.486) and 79%(k = 0.593), respectively. FICE 1 improved the delineation of 97.4% of angioectasias, 63.3% of ulcers/erosions and 66.7% of villous edema/atrophy with a percentage of agreement of 97.4%(k = 0.910), 81.6%(k = 0.714) and 91.7%(k = 0.815), respectively. FICE 2 improved the delineation of 97.4% of angioectasias, 57.1% of ulcers/erosions and 66.7% of villous edema/atrophy, with a percentage of agreement of 89.7%(k = 0.802), 79,6%(k = 0.703) and 91.7%(k = 0.815), respectively. FICE 3 improved the delineation of 46.2% of angioecta-sias, 24.5% of ulcers/erosions and none of the cases of villous edema/atrophy, with a percentage of agreement of 53.8% [k = not available(NA)], 75.5%(k = NA) and 66.7%(k = 0.304), respectively. The BF improved the delineation of 15.4% of angioectasias, 61.2% of ulcers/erosions and 25% of villous edema/atrophy, with a per-centage of agreement of 76.9%(k = 0.558), 81.6%(k = 0.570) and 25.0%(k = NA), respectively.CONCLUSION: Virtual chromoendoscopy can improve the delineation of angioectasias, ulcers/erosions and villous edema/atrophy detected by SBCE, with almost perfect interobserver agreement for FICE 1.展开更多
The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River,which are undergoing invasion by Spartina alterniflora,were assessed to determine the potential utility of remotely sensed dat...The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River,which are undergoing invasion by Spartina alterniflora,were assessed to determine the potential utility of remotely sensed data in assessing future invasion and changes in species composition.Following a review of published research on remote sensing of salt marshes,53 locations along three transects were sampled for paired data on plant species composition and spectral reflectance using a FieldSpecTM Pro JR Field Portable Spectroradiometer.Spectral data were processed concerning reflectance,and the averaged reflectance values for each sample were reanalysed to correspond to a 12-waveband bandset of the Compact Airborne Spectral Imager.The spectral data were summarised using principal components analysis(PCA)and the relationships between the vegetation composition,and the PCA axes of spectral data were examined.The first PCA axis of the reflectance data showed a strong correlation with variability in near infrared reflectance and‘brightness’,while the second axis was correlated with visible reflectance and‘greenness’.Total vegetation cover,vegetation height,and mudflat cover were all significantly related to the first axis.The implications of this in terms of the ability of remote sensing to distinguish the various salt marsh species and in particular the invasive species S.alterniflora were discussed.Major differences in species with various physiognomies could be recognised but problems occurred in separating early colonising S.alterniflora from other species at that stage.Further work using multi-seasonal hyperspectral data might assist in solving these problems.展开更多
Background and Aims:Hepatocellular carcinoma(HCC)is the most common primary hepatic malignancy.This study was designed to investigate the value of computed tomography(CT)spectral imaging in differentiating HCC from he...Background and Aims:Hepatocellular carcinoma(HCC)is the most common primary hepatic malignancy.This study was designed to investigate the value of computed tomography(CT)spectral imaging in differentiating HCC from hepatic hemangioma(HH)and focal nodular hyperplasia(FNH).Methods:This was a retrospective study of 51 patients who underwent spectral multiple-phase CT at 40–140 keV during the arterial phase(AP)and portal venous phase(PP).Slopes of the spectral curves,iodine density,water density derived from iodine-and water-based material decomposition images,iodine uptake ratio(IUR),normalized iodine concentration,and the ratio of iodine concentration in liver lesions between AP and PP were measured or calculated.Results:As energy level decreased,the CT values of HCC(n=31),HH(n=17),and FNH(n=7)increased in both AP and PP.There were significant differences in IUR in the AP,IUR in the PP,normalized iodine concentration in the AP,slope in the AP,and slope in the PP among HCC,HH,and FNH.The CT values in AP,IUR in the AP and PP,normalized iodine concentration in the AP,slope in the AP and PP had high sensitivity and specificity in differentiating HH and HCC from FNH.Quantitative CT spectral data had higher sensitivity and specificity than conventional qualitative CT image analysis during the combined phases.Conclusions:Mean CT values at low energy(40–90 keV)and quantitative analysis of CT spectral data(IUR in the AP)could be helpful in the differentiation of HCC,HH,and FNH.展开更多
Amyloid deposits are one of the hallmark pathological lesions of Alzheimer's disease(AD). They can be visualized by thioflavin-S, silver impregnation,Congo red staining, and immunohistochemical reactions.However, ...Amyloid deposits are one of the hallmark pathological lesions of Alzheimer's disease(AD). They can be visualized by thioflavin-S, silver impregnation,Congo red staining, and immunohistochemical reactions.However, that amyloid deposits generate blue autofluorescence(auto-F) has been ignored. Here, we report that visible light-induced auto-F of senile plaques(SPs) was detected and validated with conventional methods. Brain slices from APP/PS1(amyloid precursor protein/presenilin1) transgenic mice were mounted on slides, rinsed,coverslipped and observed for details of the imaging and spectral characteristics of the auto-F of SPs. Then the slices were treated with the above classic methods for comparative validation. We found that the SP auto-F was greatest under blue-violet excitation with a specific emission spectrum, and was much easier, more sensitive, and reliable than the classic methods. Because it does not damage slices, observation of auto-F can be combined with all post-staining techniques in slices and for brain-wide imaging in AD.展开更多
It is difficult to differentiate small,but harmful,shell fragments of Chinese hickory nuts from their kernels since they are very similar in color.Including shell fragments of Chinese hickory nuts by mistake may creat...It is difficult to differentiate small,but harmful,shell fragments of Chinese hickory nuts from their kernels since they are very similar in color.Including shell fragments of Chinese hickory nuts by mistake may create safety hazards for consumers.Therefore,there is a need to develop an effective method to differentiate the shells from the kernels of Chinese hickory nuts.In this study,a deep learning approach based on a two-dimensional convolutional neural network(2D CNN)and long short-term memory(LSTM)integrated with hyperspectral imaging for distinguishing the shells and kernels of Chinese hickory nuts at the pixel level was proposed.Two classical classification methods,principal component analysis-K-nearest neighbors(PCA-KNN)and the support vector machine(SVM),were employed to establish identification models for comparison.The results showed that the 2D CNN-LSTM model achieved the best performance with an overall classification accuracy of 99.0%.Moreover,the shells in mixtures of shells and kernels were detected based on the proposed deep learning method and visualized for subsequent operations for the removal of foreign bodies.展开更多
Snapshot spectral ghost imaging,which can acquire dynamic spectral imaging information in the field of view,has attracted increasing attention in recent years.Studies have shown that optimizing the fluctuation of ligh...Snapshot spectral ghost imaging,which can acquire dynamic spectral imaging information in the field of view,has attracted increasing attention in recent years.Studies have shown that optimizing the fluctuation of light fields is essential for improving the sampling efficiency and reconstruction quality of ghost imaging.However,the optimization of broadband light fields in snapshot spectral ghost imaging is challenging because of the dispersion of the modulation device.In this study,by judiciously introducing a hybrid refraction/diffraction structure into the light-field modulation,snapshot spectral ghost imaging with broadband super-Rayleigh speckles was demonstrated.The simulation and experiment results verified that the contrast of speckles in a broad range of wavelengths was significantly improved,and the imaging system had superior noise immunity.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61505178,61307019,and 11504333)the Natural Science Foundation of Henan Province,China(Grant Nos.18A140032,15A140038,and 16A140035)。
文摘Fresnel incoherent correlation holography(FINCH) is a unique three-dimensional(3D) imaging technique which has the advantages of scanning-free,high resolution,and easy matching with existing mature optical systems.In this article,an incoherent digital holographic spectral imaging method with high accuracy of spectral reconstruction based on liquid crystal tunable filter(LCTF) and FINCH is proposed.Using the programmable characteristics of spatial light modulator(SLM),a series of phase masks,none of whose focal lengths changes with wavelength,is designed and made.For each wavelength of LCTF output,SLM calls three phase masks with different phase constants at the corresponding wavelength,and CCD records three holograms.The spectral images obtained by this method have a constant magnification,which can achieve pixel-level image registration,restrain image registration errors,and improve spectral reconstruction accuracy.The results show that this method can not only obtain the 3D spatial information and spectral information of the object simultaneously,but also have high accuracy of spectral reconstruction and excellent color reproducibility.
基金supported by the National Key R&D Program of China(Grant No.:2017YFC1702003)the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(Grant No.:2019e12M-5-078).
文摘Traditional Chinese medicine(TCM)is a treasure of the Chinese nation,providing effective solutions to current medical requisites.Various spectral techniques are undergoing continuous development and provide new and reliable means for evaluating the efficacy and quality of TCM.Because spectral techniques are noninvasive,convenient,and sensitive,they have been widely applied to in vitro and in vivo TCM evaluation systems.In this paper,previous achievements and current progress in the research on spectral technologies(including fluorescence spectroscopy,photoacoustic imaging,infrared thermal imaging,laser-induced breakdown spectroscopy,hyperspectral imaging,and surface enhanced Raman spectroscopy)are discussed.The advantages and disadvantages of each technology are also presented.Moreover,the future applications of spectral imaging to identify the origins,components,and pesticide residues of TCM in vitro are elucidated.Subsequently,the evaluation of the efficacy of TCM in vivo is presented.Identifying future applications of spectral imaging is anticipated to promote medical research as well as scientific and technological explorations.
基金Supported By The Russian Science Foundation Grant No.23-21-00115,https://rscf.ru/en/project/23-21-00115/.
文摘Multi-channel polarization optical technology is increasingly used for prompt monitoring of water systems.Optical devices during the assessment of water quality determine the intensity of light through the studied aquatic environment.Spectrophotometric devices measure the spectrum of weakening of light through the aquatic environment.Spectroellipsometric devices receive spectra in vertical and horizontal polarizations.The presented article develops an adaptive optical hardware and image system for monitoring water bodies.The system is combined.It consists of 2 parts:1)automated spectrophotometer-refractometer,and 2)adaptive spectroellipsometer.The system is equipped with a corresponding algorithmic and software,including algorithms for identifying spectral curves,databases and knowledge of spectral curves algorithms for solving reverse problems.The presented system is original since it differs from modern foreign systems by a new method of spectrophotometric and spectroellipsometric measurements,an original elemental base of polarization optics and a comprehensive mathematical approach to assessing the quality of a water body.There are no rotating polarization elements in the system.Therefore,this makes it possible to increase the signal-to-noise ratio and,as a result,improve measurement stability and simplify multichannel spectrophotometers and spectroellipsometers.The proposed system can be used in various water systems where it is necessary to assess water quality or identify the presence of a certain set of chemical elements.
文摘Authentication of pasta is currently determined using molecular biology-based techniques focusing on DNA as the target analyte. Whilst proven to be effective, these approaches can be criticised as being destructive, time consuming, and requiring specialist instrument training. Advances in the field of multispectral imaging (MSI) and hyperspectral imaging (HSI) have facilitated the development of compact imaging platforms with the capability to rapidly differentiate a range of materials (inclusive of grains and seeds) based on surface colour, texture and chemical composition. This preliminary investigation evaluated the applicability of spectral imaging for identification and quantitation of durum wheat grain samples in relation to pasta authenticity. MSI and HSI were capable of rapidly distinguishing between durum wheat and adulterant common wheat cultivars and assigning percentage adulteration levels characterised by low biases and good repeatability estimates. The results demonstrated the potential for spectral imaging based seed/grain adulteration testing to augment existing standard molecular approaches for food authenticity testing.
基金supported by Grant Nos.13-02-12210 and 14-00-10420 of Russian Foundation of Basic Research.
文摘The problem of in vrivo photoluminescence diagnostics of the tissues acessible by endoscopes is discussed.The spectral imaging module attachable to conventional rigid and flexible medical endoscopes is developed and described.It is based on a double acousto-optical tunable filter(AOTF)and a specialized optical coupling system.The module provides wide field of view(FOV),absence of image distortions,random spectral access,fast spectral image acquisition at any wavelength in the visible range and accurate measurement of reflectance spectrum in each pixel of the image.Images of typical biomedical samples are presented and discussed.Their spectra are compared to the reference data.
基金support of National Science and Technology Support Program (2012BAK08B02)Beijing Institute for Drug Control and Jiangsu Institute for Food and Drug Control for their generous providing of dietary supplements samples.
文摘The application to detect ilally added drugs in dietary supplerments by near-infrared spectral imaging was studied with the focus on nifedipine,diclofenac and metformin.The method is based on near-infrared spectral images correlation cofficient to detect ilally added drugs.The results comply 100%with HPLC methods test results with no false positive results.
基金the National Institutes of Health(RO1-HL084013).
文摘An introduction to the basics of spectral imaging as applied to biological tissues is presented.An example of a spectral image of a face is used to demonstrate the data and spectral analysis that specify the melanin content(M),blood content(B),tissue oxygen saturation(S),water content(W),fraction of scattering due to Rayleigh scattering(f)and due to Mie scattering(1−f),and the reduced scattering coefficient at 500-nm wavelength(µs 500 nm).The sensitivity of reflectance spectra to variation in the various parameters is illustrated.
基金supported by the National Institutes of Health,Grant CA95885.
文摘We have examined ten human subjects with a previously developed instrument for near-infrared diffuse spectral imaging of the female breast.The instrument is based on a tandem,planar scan of two collinear optical fibers(one for illumination and one for collection)to image a gently compressed breast in a transmission geometry.The optical data collection features a spatial sampling of 25 points/cm2 over the whole breast,and a spectral sampling of 2 points/nm in the 650-900nm wavelength range.Of the ten human subjects examined,eight are healthy subjects and two are cancer patients with unilateral invasive ductal carcinoma and ductal carcinoma in situ,respectively.For each subject,we generate second-derivative images that identify a network of highly absorbing structures in the breast that we assign to blood vessels.A previously developed paired-wavelength spectral method assigns oxygenation values to the absorbing structures displayed in the second-derivative images.The resulting oxygenation images feature average values over the whole breast that are significantly lower in cancerous breasts(69±14%,n=2)than in healthy breasts(85±7%,n=18)(p<0.01).Furthermore,in the two patients with breast cancer,the average oxygenation values in the cancerous regions are also significantly lower than in the remainder of the breast(invasive ductal carcinoma:49±11%vs 61±16%,p<0.01;ductal carcinoma in situ:58±8%vs 77±11%,p<0.001).
基金The authors would like to acknowledge the support of the Ph.D.research startup foundation of Guangdong Medical University (2XB14006).
文摘The content of berberine hydrochloride(BH)in compound berberine tablets(CBTs)is subject to strict requirements.Its content is usually measured based on chemical analysis.In this paper,the fluorescence spectral imaging method was used to study the relative content of BH from a physics perspective.By comparing the relative fluorescence intensity of self-made CBTs with di®erent mass percentages of BH,a linear positive relationship was observed between the BH content and the relative fluorescence intensity,and accordingly the quality of CBTs of different brands was evaluated.The results indicate that the fluorescence spectral imaging method can be a simple,fast and nondestructive semi-quantitative analysis method to determine the content of BH in CBTs,and this method has great potential in the quality control of CBTs.
基金supported by the National Natural Science Foundation of China(No.60508017)the Natural Science Foundation of Fujian Province of China(2007J0007,C0720001)+1 种基金the Science and Technology Planning Key Program of Fujian Province(2008Y0037)the Program for New Century Excellent Talents in University(NCET-07-0191).
文摘Skin scar is unique to humans,the major significant negative outcome sustained after thermal injuries,traumatic injuries,and surgical procedures.Hypertrophic scar in human skin is investigated using non-linear spectral imaging microscopy.The high contrast images and spectroscopic intensities of collagen and elastic fibers extracted from the spectral imaging of normal skin tissue,and the normal skin near and far away from the hypertrophic scar tissues in a 10-year-old patient case are obtained.The results show that there are apparent differences in the morphological structure and spectral characteristics of collagen and elastic fibers when comparing the normal skin with the hypertrophic scar tissue.These differences can be good indicators to differentiate the normal skin and hypertrophic scar tissue and demonstrate that non-linear spectral imaging microscopy has potential to noninvasively investigate the pathophysiology of human hypertrophic scar.
基金This work was supported by the National Council for Science and Technology Grant funded by the Government of Kenya(NCST/ST&I/RCD/4TH call PhD/201).
文摘Neural network analysis based on Growing Hierarchical Self-Organizing Map (GHSOM) is used to examine Spatial-Temporal characteristics in Aerosol Optical Depth (AOD), Ångström Exponent (ÅE) and Precipitation Rate (PR) over selected East African sites from 2000 to 2014. The selected sites of study are Nairobi (1°S, 36°E), Mbita (0°S, 34°E), Mau Forest (0.0° - 0.6°S;35.1°E - 35.7°E), Malindi (2°S, 40°E), Mount Kilimanjaro (3°S, 37°E) and Kampala (0°N, 32.1°E). GHSOM analysis reveals a marked spatial variability in AOD and ÅE that is associated to changing PR, urban heat islands, diffusion, direct emission, hygroscopic growth and their scavenging from the atmosphere specific to each site. Furthermore, spatial variability in AOD, ÅE and PR is distinct since each variable corresponds to a unique level of classification. On the other hand, GHSOM algorithm efficiently discriminated by means of clustering between AOD, ÅE and PR during Long and Short rain spells and dry spell over each variable emphasizing their temporal evolution. The utilization of GHSOM therefore confirms the fact that regional aerosol characteristics are highly variable be it spatially or temporally and as well modulated by PR received over each variable.
基金We acknowledge the financial supports from the National Key R&D Program of China(2021YFF0502900)the National Natural Science Foundation of China(61975033)Shanghai Municipal Science and Technology Major Project No.2018SHZDZX01 and ZJLab.
文摘Beneting from the developments of advanced optical microscopy techniques,the mysteries of biological functions at the cellular and subcellular levels have been continuously revealed.Stimulated Raman scattering(SRS)microscopy is a rapidly growing technique that has attracted broad attentions and become a powerful tool for biology and biomedicine,largely thanks to its chemical specicity,high sensitivity and fast image speed.This review paper introduces the principles of SRS,discusses the technical developments and implementations of SRS microscopy,then highlights and summarizes its applications on biological cellular machinery andnally shares our visions of potential breakthroughs in the future.
基金funding provided by Universitàdi Pisa within the CRUI-CARE Agreement。
文摘Sustainable forest management is essential to confront the detrimental impacts of diseases on forest ecosystems.This review highlights the potential of vegetation spectroscopy in improving the feasibility of assessing forest disturbances induced by diseases in a timely and cost-effective manner.The basic concepts of vegetation spectroscopy and its application in phytopathology are first outlined then the literature on the topic is discussed.Using several optical sensors from leaf to landscape-level,a number of forest diseases characterized by variable pathogenic processes have been detected,identified and quantified in many country sites worldwide.Overall,these reviewed studies have pointed out the green and red regions of the visible spectrum,the red-edge and the early near-infrared as the spectral regions most sensitive to the disease development as they are mostly related to chlorophyll changes and symptom development.Late disease conditions particularly affect the shortwave-infrared region,mostly related to water content.This review also highlights some major issues to be addressed such as the need to explore other major forest diseases and geographic areas,to further develop hyperspectral sensors for early detection and discrimination of forest disturbances,to improve devices for remote sensing,to implement longterm monitoring,and to advance algorithms for exploitation of spectral data.Achieving of these goals will enhance the capability of vegetation spectroscopy in early detection of forest stress and in managing forest diseases.
基金The National Natural Science Foundation of China(Grant No.U22A6004)The National Key Research and Development Program of China(2022YFF1501600).
文摘Spectral imaging extends the concept of traditional color cameras to capture images across multiple spectral channels and has broad ap-plication prospects.Conventional spectral cameras based on scanning methods suffer from the drawbacks of low acquisition speed and large volume.On-chip computational spectral imaging based on metasur-face filters provides a promising scheme for portable applications,but endures long computation time due to point-by-point iterative spec-tral reconstruction and mosaic effect in the reconstructed spectral im-ages.In this study,on-chip rapid spectral imaging was demonstrated,which eliminated the mosaic effect in the spectral image by deep-learning-based spectral data cube reconstruction.The experimental results show that 4 orders of magnitude faster than the iterative spec-tral reconstruction were achieved,and the fidelity of the spectral re-construction for the standard color plate was over 99%for a standard color board.In particular,video-rate spectral imaging was demon-strated for moving objects and outdoor driving scenes with good per-formance for recognizing metamerism,where the concolorous sky and white cars can be distinguished via their spectra,showing great po-tential for autonomous driving and other practical applications in the field of intelligent perception.
文摘AIM: To evaluate whether virtual chromoendoscopy can improve the delineation of small bowel lesions previously detected by conventional white light small bowel capsule endoscopy(SBCE). METHODS: Retrospective single center study. One hundred lesions selected from forty-nine consecutive conventional white light SBCE(SBCE-WL) examinations were included. Lesions were reviewed at three Flexible Spectral Imaging Color Enhancement(FICE) settings and Blue Filter(BF) by two gastroenterologists with ex-perience in SBCE, blinded to each other's findings, whoranked the quality of delineation as better, equivalent or worse than conventional SBCE-WL. Inter-observer percentage of agreement was determined and analyzed with Fleiss Kappa(k) coefficient. Lesions selected for the study included angioectasias(n = 39), ulcers/ero-sions(n = 49) and villous edema/atrophy(n = 12). RESULTS: Overall, the delineation of lesions was im-proved in 77% of cases with FICE 1, 74% with FICE 2, 41% with FICE 3 and 39% with the BF, with a percent-age of agreement between investigators of 89%(k = 0.833), 85%(k = 0.764), 66%(k = 0.486) and 79%(k = 0.593), respectively. FICE 1 improved the delineation of 97.4% of angioectasias, 63.3% of ulcers/erosions and 66.7% of villous edema/atrophy with a percentage of agreement of 97.4%(k = 0.910), 81.6%(k = 0.714) and 91.7%(k = 0.815), respectively. FICE 2 improved the delineation of 97.4% of angioectasias, 57.1% of ulcers/erosions and 66.7% of villous edema/atrophy, with a percentage of agreement of 89.7%(k = 0.802), 79,6%(k = 0.703) and 91.7%(k = 0.815), respectively. FICE 3 improved the delineation of 46.2% of angioecta-sias, 24.5% of ulcers/erosions and none of the cases of villous edema/atrophy, with a percentage of agreement of 53.8% [k = not available(NA)], 75.5%(k = NA) and 66.7%(k = 0.304), respectively. The BF improved the delineation of 15.4% of angioectasias, 61.2% of ulcers/erosions and 25% of villous edema/atrophy, with a per-centage of agreement of 76.9%(k = 0.558), 81.6%(k = 0.570) and 25.0%(k = NA), respectively.CONCLUSION: Virtual chromoendoscopy can improve the delineation of angioectasias, ulcers/erosions and villous edema/atrophy detected by SBCE, with almost perfect interobserver agreement for FICE 1.
基金This research was funded by the Key Project of the Shanghai Science and Technology Committee(Grant No.06DZ12302)National Basic Research Program of China(Grant No.2004CB720505).
文摘The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River,which are undergoing invasion by Spartina alterniflora,were assessed to determine the potential utility of remotely sensed data in assessing future invasion and changes in species composition.Following a review of published research on remote sensing of salt marshes,53 locations along three transects were sampled for paired data on plant species composition and spectral reflectance using a FieldSpecTM Pro JR Field Portable Spectroradiometer.Spectral data were processed concerning reflectance,and the averaged reflectance values for each sample were reanalysed to correspond to a 12-waveband bandset of the Compact Airborne Spectral Imager.The spectral data were summarised using principal components analysis(PCA)and the relationships between the vegetation composition,and the PCA axes of spectral data were examined.The first PCA axis of the reflectance data showed a strong correlation with variability in near infrared reflectance and‘brightness’,while the second axis was correlated with visible reflectance and‘greenness’.Total vegetation cover,vegetation height,and mudflat cover were all significantly related to the first axis.The implications of this in terms of the ability of remote sensing to distinguish the various salt marsh species and in particular the invasive species S.alterniflora were discussed.Major differences in species with various physiognomies could be recognised but problems occurred in separating early colonising S.alterniflora from other species at that stage.Further work using multi-seasonal hyperspectral data might assist in solving these problems.
基金This work was supported by the National Natural Science Foundation of China(Grant number 81401406)the Innovative Research Team of High-Level Local Universities in Shanghai.
文摘Background and Aims:Hepatocellular carcinoma(HCC)is the most common primary hepatic malignancy.This study was designed to investigate the value of computed tomography(CT)spectral imaging in differentiating HCC from hepatic hemangioma(HH)and focal nodular hyperplasia(FNH).Methods:This was a retrospective study of 51 patients who underwent spectral multiple-phase CT at 40–140 keV during the arterial phase(AP)and portal venous phase(PP).Slopes of the spectral curves,iodine density,water density derived from iodine-and water-based material decomposition images,iodine uptake ratio(IUR),normalized iodine concentration,and the ratio of iodine concentration in liver lesions between AP and PP were measured or calculated.Results:As energy level decreased,the CT values of HCC(n=31),HH(n=17),and FNH(n=7)increased in both AP and PP.There were significant differences in IUR in the AP,IUR in the PP,normalized iodine concentration in the AP,slope in the AP,and slope in the PP among HCC,HH,and FNH.The CT values in AP,IUR in the AP and PP,normalized iodine concentration in the AP,slope in the AP and PP had high sensitivity and specificity in differentiating HH and HCC from FNH.Quantitative CT spectral data had higher sensitivity and specificity than conventional qualitative CT image analysis during the combined phases.Conclusions:Mean CT values at low energy(40–90 keV)and quantitative analysis of CT spectral data(IUR in the AP)could be helpful in the differentiation of HCC,HH,and FNH.
基金supported by the National Natural Science Foundation of China (31771156 and 31400945)
文摘Amyloid deposits are one of the hallmark pathological lesions of Alzheimer's disease(AD). They can be visualized by thioflavin-S, silver impregnation,Congo red staining, and immunohistochemical reactions.However, that amyloid deposits generate blue autofluorescence(auto-F) has been ignored. Here, we report that visible light-induced auto-F of senile plaques(SPs) was detected and validated with conventional methods. Brain slices from APP/PS1(amyloid precursor protein/presenilin1) transgenic mice were mounted on slides, rinsed,coverslipped and observed for details of the imaging and spectral characteristics of the auto-F of SPs. Then the slices were treated with the above classic methods for comparative validation. We found that the SP auto-F was greatest under blue-violet excitation with a specific emission spectrum, and was much easier, more sensitive, and reliable than the classic methods. Because it does not damage slices, observation of auto-F can be combined with all post-staining techniques in slices and for brain-wide imaging in AD.
基金The authors gratefully acknowledge the financial support of the National Key Research and Development Program of China(Grant No.2017YFC1600805)the help of Jie Yang in studying convolution neural networks.Trade and manufacturer names are necessary to report factually on the available data。
文摘It is difficult to differentiate small,but harmful,shell fragments of Chinese hickory nuts from their kernels since they are very similar in color.Including shell fragments of Chinese hickory nuts by mistake may create safety hazards for consumers.Therefore,there is a need to develop an effective method to differentiate the shells from the kernels of Chinese hickory nuts.In this study,a deep learning approach based on a two-dimensional convolutional neural network(2D CNN)and long short-term memory(LSTM)integrated with hyperspectral imaging for distinguishing the shells and kernels of Chinese hickory nuts at the pixel level was proposed.Two classical classification methods,principal component analysis-K-nearest neighbors(PCA-KNN)and the support vector machine(SVM),were employed to establish identification models for comparison.The results showed that the 2D CNN-LSTM model achieved the best performance with an overall classification accuracy of 99.0%.Moreover,the shells in mixtures of shells and kernels were detected based on the proposed deep learning method and visualized for subsequent operations for the removal of foreign bodies.
文摘Snapshot spectral ghost imaging,which can acquire dynamic spectral imaging information in the field of view,has attracted increasing attention in recent years.Studies have shown that optimizing the fluctuation of light fields is essential for improving the sampling efficiency and reconstruction quality of ghost imaging.However,the optimization of broadband light fields in snapshot spectral ghost imaging is challenging because of the dispersion of the modulation device.In this study,by judiciously introducing a hybrid refraction/diffraction structure into the light-field modulation,snapshot spectral ghost imaging with broadband super-Rayleigh speckles was demonstrated.The simulation and experiment results verified that the contrast of speckles in a broad range of wavelengths was significantly improved,and the imaging system had superior noise immunity.