Inhibition Effect of Okanin Toward Human Cytochrome P450 3A4 and 2D6 with Multi-spectroscopic Studies and Molecular Docking.

Okanin, a major flavonoid of a popular herb tea, Coreopsis tinctoria Nutt., showed strong inhibition on CYP3A4 and CYP2D6. The strong interaction between okanin and CYPs were determined by enzyme kinetics, multispectral technique and molecular docking. The inhibition type of two enzymes, CYP3A4 and CYP2D6, by okanin are mixed and non-competitive inhibition type, respectively. The IC50 values and the binding constant of okanin to CYP3A4 can be deduced that the interaction was stronger than that of CYP2D6. The Conformations of CYP3A4 and CYP2D6 were changed by okanin. The evidence from fluorescence measurement along with molecular docking verified that these two CYPs were bound with okanin by hydrogen bonds and hydrophobic forces. Our investigation suggested that okanin may lead to interactions between herb and drug by inhibiting CYP3A4 and CYP2D6 activities, thus its consumption should be taken with caution.

Effect of Chloramphenicol as Antibiotic on the Structure and Function of Pepsin and Its Mechanism of Action.

The interaction between chloramphenicol (CHL) and pepsin (PEP), as well as the impact of CHL on PEP conformation, were investigated using spectroscopic techniques and molecular docking simulations in this study. The experimental results demonstrate that CHL exhibits a static quenching effect on PEP. The thermodynamic parameters indicate that the reaction between CHL and PEP is spontaneous, primarily driven by hydrogen bonding and van der Waals forces. Moreover, the binding distance of r<7 nm suggests the occurrence of Förster's non-radiative energy transfer between these two molecules. In the synchronous fluorescence spectrum, the maximum fluorescence intensity of PEP produced a redshift phenomenon, indicating that CHL was bound to tryptophan residues of PEP. The addition of CHL induces changes in the secondary structure of PEP, as confirmed by the observed alterations in peak values in three-dimensional fluorescence spectra. The UV spectra reveal a redshift of 3 nm in the maximum absorption peak, indicating a conformational change in the secondary structure of PEP upon addition of CHL. Circular dichroism analysis demonstrates significant alterations in the α-helix, ß-sheet, ß-turn, and random coil contents of PEP before and after CHL incorporation, further confirming its ability to modulate the secondary structure of PEP.

Characterization of the interactions between Fulvic acid and Trypsin with Spectroscopic and Molecular Docking technology.

The interaction mechanism between trypsin and fulvic acid was analyzed by multispectral method and molecular docking simulation. The fluorescence spectra showed that fulvic acid induced static quenching of trypsin. The validity of this conclusion was further substantiated through the computation of the binding constants. The thermodynamic parameters show that the reaction is mainly controlled by van der Waals force and hydrogen bond force, and the reaction is spontaneous. In addition, based on the obtained binding distance, there may be a non-radiative energy transfer between the two. The ultraviolet spectrum showed that fulvic acid could shift the absorption peak of trypsin, indicating that fulvic acid had an effect on the secondary structure of trypsin. According to the synchronous fluorescence spectrum results, fulvic acid primarily interacts with tryptophan residues in trypsin and induces alterations in their microenvironment. Three-dimensional fluorescence spectrum and circular dichroism further proves this conclusion. The molecular docking simulation reveals that the interaction between the two groups primarily arises from hydrogen bonding and van der Waals forces. The findings suggest that FA has the ability to induce conformational changes in trypsin's secondary structure.

Multi-Wavelength Raman Differentiation of Malignant Skin Neoplasms.

Raman microspectroscopy has become an effective method for analyzing the molecular appearance of biomarkers in skin tissue. For the first time, we acquired in vitro Raman spectra of healthy and malignant skin tissues, including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), at 532 and 785 nm laser excitation wavelengths in the wavenumber ranges of 900-1800 cm-1 and 2800-3100 cm-1 and analyzed them to find spectral features for differentiation between the three classes of the samples. The intensity ratios of the bands at 1268, 1336, and 1445 cm-1 appeared to be the most reliable criteria for the three-class differentiation at 532 nm excitation, whereas the bands from the higher wavenumber region (2850, 2880, and 2930 cm-1) were a robust measure of the increased protein/lipid ratio in the tumors at both excitation wavelengths. Selecting ratios of the three bands from the merged (532 + 785) dataset made it possible to increase the accuracy to 87% for the three classes and reach the specificities for BCC + SCC equal to 87% and 81% for the sensitivities of 95% and 99%, respectively. Development of multi-wavelength excitation Raman spectroscopic techniques provides a versatile non-invasive tool for research of the processes in malignant skin tumors, as well as other forms of cancer.

Characterization of the Interactions between Minocycline Hydrochloride and Trypsin with Spectroscopic and Molecular Docking Technology.

In the current study, the interaction of minocycline hydrochloride (MC) and trypsin (TRP) was studied using fluorescence spectroscopy, synchronous fluorescence spectroscopy, three-dimensional fluorescence spectroscopy, UV-Vis spectroscopy, and molecular docking simulation techniques. The results show that the fluorescence quenching of trypsin at different degrees can be caused by minocycline hydrochloride at different temperatures. According to the Stern-Volmer equation, the fluorescence quenching type was static quenching. By calculating critical distance, we concluded that there is a possibility of non-radiative energy transfer between minocycline hydrochloride and trypsin. The effect of minocycline hydrochloride on the secondary structure of trypsin was demonstrated using ultraviolet spectroscopy. Synchronous fluorescence spectroscopy showed that minocycline hydrochloride could bind to tryptophan residues in trypsin, resulting in corresponding changes in the secondary structure of trypsin. Three-dimensional fluorescence spectroscopy showed that minocycline hydrochloride had a particular effect on the microenvironment of trypsin that led to changes in the secondary structure of trypsin. The molecular docking technique demonstrated that the binding of minocycline hydrochloride and trypsin was stable. Circular dichroism showed that the secondary structure of trypsin could be changed by minocycline hydrochloride.

Fusion of Different Image Sources for Improved Monitoring of Agricultural Plots.

In the Valencian Community, the applications of precision agriculture in multiannual woody crops with high added value (fruit trees, olive trees, almond trees, vineyards, etc.) are of priority interest. In these plots, canopies do not fully cover the soil and the planting frames are incompatible with the Resolution of Sentinel 2. The present work proposes a procedure for the fusion of images with different temporal and spatial resolutions and with different degrees of spectral quality. It uses images from the Sentinel 2 mission (low resolution, high spectral quality, high temporal resolution), orthophotos (high resolution, low temporal resolution) and images obtained with drones (very high spatial resolution, low temporal resolution). The procedure is applied to generate time series of synthetic RGI images (red, green, infrared) with the same high resolution of orthophotos and drone images, in which gray levels are reassigned from the combination of their own RGI bands and the values of the B3, B4 and B8 bands of Sentinel 2. Two practical examples of application are also described. The first shows the NDVI images that can be generated after the process of merging two RGI Sentinel 2 images obtained on two specific dates. It is observed how, after the merging, different NDVI values can be assigned to the soil and vegetation, which allows them to be distinguished (contrary to the original Sentinel 2 images). The second example shows how graphs can be generated to describe the evolution throughout the vegetative cycle of the estimated values of three spectral indices (NDVI, GNDVI, GCI) on a point in the image corresponding to soil and on another assigned to vegetation. The robustness of the proposed algorithm has been validated by using image similarity metrics.

[Capabilities of using a multifunctional led device in the study of objects of forensic examination]. / Vozmozhnosti ispol'zovaniya mnogofunktsional'nogo svetodiodnogo pribora v issledovanii ob"ektov sudebnykh ekspertiz.

The purpose of the work is to determine the capabilities of the modern multifunctional device «Photobox 3138¼ with LED illuminators with a high color rendering index for photofixation, colorimetric, spectrozonal and multispectral analyzes of forensic objects. The competencies of the «Photobox 3138¼ device were experimentally revealed in terms of visualization and photofixation of both traces of biological origin (blood, sweat fat, saliva, etc.) and traces of traditional examinations, including shot products, oil products. The design of the device with a working field of 300×300 mm provides for the optimal arrangement of LED illuminators, including white light with a high color rendering index; spectrum-zonal illuminator with 4 types of LEDs with narrow non-intersecting spectral lines (458.1; 523.1; 594.1 and 630.6 nm) in the visible range of the spectrum; UV- (370 nm) and IR- (850 nm) illuminators. The fundamental possibility of using the resulting digital images of forensic objects for subsequent mathematical processing is experimentally shown. Images taken in different spectral ranges help to detect traces and damage. It was found that «Photobox 3138¼ allows you to solve a variety of diagnostic tasks related to the search, visualization, fixation and analysis of trace information.

Machine Learning Approach for Determining the Formation of ß-Lactam Antibiotic Complexes with Cyclodextrins Using Multispectral Analysis.

The problem of determining the formation of complexes of ß-lactam antibiotics with cyclodextrins (CDs) and the interactions involved in this process were addressed by machine learning on multispectral images. Complexes of ß-lactam antibiotics, including cefuroxime axetil, cefetamet pivoxil, and pivampicillin, as well as CDs, including αCD, ßCD, γCD, hydroxypropyl-αCD, methyl-ßCD, hydroxypropyl-ßCD, and hydroxypropyl-γCD, were prepared in all combinations. Thermograms confirming the formation of cyclodextrin complexes were obtained using differential scanning calorimetry. Transmission Fourier-transform infrared (tFTIR) and complementary attenuated total reflectance FTIR (ATR) coupled with machine learning were techniques chosen as a nondestructive alternative. The machine learning algorithm was used to determine the formation of complexes in samples using solely their tFTIR and ATR spectra at the prediction stage. Parameterized method 7 (PM7) was used to support the analysis by molecular modeling of the complexes. The model developed through machine learning properly distinguished samples with formed complexes form noncomplexed samples with a cross-validation accuracy of 90.4%. Analysis of the contribution of spectral bands to the model indicated interactions of ester groups of ß-lactam antibiotics with CDs, as well as some interactions of cephem ring in cefetamet pivoxil and penam moiety in pivampicillin. Molecular modeling with PM7 helped to explain experimental results and allowed to propose possible binding modes.

Insight into the binding mechanisms of fluorinated 2-aminothiazole sulfonamide and human serum albumin: Spectroscopic and in silico approaches.

4-Fluoro-N-(thiazol-2-yl)benzenesulfonamide (3) is a novel fluorinated compound, containing various biological activities. Therefore, absorption spectroscopy, fluorescence quenching, molecular docking, and molecular simulation were employed to investigate the interaction between 3 and human serum albumin (HSA). Firstly, compound 3 meets all criteria for drug-likeness prediction. UV absorption spectra revealed the interaction of 3 with HSA altered the microenvironment of protein, as well as circular dichroism spectroscopic analysis indicated slightly conformational changes and a reduction in α-helical content. The binding parameters of the HSA-3 complex suggested that fluorescence quenching is driven by combined static and dynamic processes. Additionally, the stability of the complex is attributed to conventional hydrogen and hydrophobic bonding interactions. Furthermore, esterase-like activity indicated that the binding of 3 might disrupt HSA's bond networks, leading to structural alterations. Consequently, the strong binding constant (Ka ≈ 1.204 × 106 M-1) aligns with the predicted unbound fraction (0.28) in serum, indicating that thiazole 3 has good bioavailability in plasma and can be effectively transported to target sites, thereby exerting its pharmaceutical effects. However, careful dosage management is essential to prevent potential adverse effects. Overall, these findings highlight the potential of 3 as a therapeutic agent, emphasizing the need for further research to optimize its uses.

Near-infrared multispectral photoacoustic analysis of lipids and intraplaque hemorrhage in human carotid artery atherosclerosis.

Spectral photoacoustic imaging in combination with unmixing techniques may be applied to retrieve information about high-risk features present in atherosclerotic plaques, possibly providing prognostic insights into future stroke events. We present the photoacoustic spectral contrast found in 12 systematically scanned advanced atherosclerotic plaques in the near-infrared wavelength range (850-1250 nm). The main absorbers are lipid, water, and hemoglobin, with the highest photoacoustic intensities at the lipid's second overtone at 1190 and 1210 nm. Linear unmixing resulted in visualizing regions with high lipid and hemoglobin absorption, corresponding to the histological presence of lipid and intraplaque hemorrhage. A non-negative matrix factorization approach reveals differences in lipid spectral contrast, providing potential insights into the vulnerability of atherosclerotic plaque. These results provide a reference for future, more complex, in vivo photoacoustic imaging of carotid artery atherosclerosis, potentially contributing to assessing the risk of future events and treatment decision.

The molecular mechanisms of TRß receptor interaction with polychlorinated biphenyls: A multispectral and computational exploration.

The thyroid hormone (TH) system is susceptible to the toxic effects of polychlorinated biphenyls (PCBs). Pollutants may disrupt the TH system by binding to serum TH transport proteins or interacting with thyroid hormone receptors (TRs) in target cells. However, the molecular mechanism of interaction with the Thyroid Hormone Receptor Beta (TRß) is not fully understood. This study employed fluorescence, UV-visible absorption, three-dimensional fluorescence, and Fourier-transform infrared spectroscopy, along with molecular docking and molecular dynamics simulations, to investigate the interaction between TRß and PCBs. Moreover, molecular docking and fluorescence resonance energy transfer (FRET) findings suggest that TRß and PCBs underwent resonance energy transfer consistent with Förster's theory. The root mean square deviation (RMSD) and docking outcomes indicate that the TRß-PCB29 complex exhibited optimal structural stability. Thus, the study concludes that integrating spectroscopic data with molecular docking is essential for a comprehensive analysis. Further analysis of intermolecular interactions using quantum chemistry and reduced density gradient analysis (RDG) analysis revealed that van der Waals forces are the primary drivers of PCBs to TRß.

Contrasting water-use strategies revealed by species-specific transpiration dynamics in the Caatinga dry forest.

In forest ecosystems, transpiration (T) patterns are important for quantifying water and carbon fluxes and are major factors in predicting ecosystem change. Seasonal changes in rainfall and soil water content can alter the sensitivity of sap flux density to daily variations in vapor pressure deficit (VPD). This sensitivity is species-specific and is thought to be related to hydraulic strategies. The aim of this work is to better understand how the sap flux density of species with low versus high wood density differ in their sensitivity to VPD and soil water content and how potentially opposing water-use strategies influence T dynamics, and ultimately, correlations to evapotranspiration (ET). We use hysteresis area analysis to quantify the sensitivity of species-specific sap flux density to changes in the VPD, breakpoint-based models to determine the soil water content threshold instigating a T response and multiscalar wavelet coherency to correlate T to ET. We found that low wood density Commiphora leptophloeos (Mart.) Gillett had a more dynamic T pattern, a greater sensitivity to VPD at high soil water content, required a higher soil water content threshold for this sensitivity to be apparent, and had a significant coherency correlation with ET at daily to monthly timescales. This behavior is consistent with a drought avoidance strategy. High wood density Cenostigma pyramidale  (Tul.)  E. Gagnon & G. P. Lewis, conversely, had a more stable T pattern, responded to VPD across a range of soil water content, tolerated a lower soil water content threshold to T, and had a significant coherency correlation with ET at weekly timescales. This behavior is consistent with a drought-tolerant strategy. We build on previous research to show that these species have contrasting water-use strategies that should be considered in large-scale modeling efforts.

Hydroxyl group-induced enhancement of antioxidant activity of resveratrol over pterostilbene by binding to lactoferrin.

The reduced antioxidant capacity of trans-resveratrol (Res) than the second generation of Res, namely pterostilbene (Pte), severely prohibits its in-depth intriguing radical-scavenging applications in food formulations. Herein, a unique chemical structure-dependent strategy was proposed to specifically enhance the radical scavenging activity of Res over Pte, relying on the two more hydroxyl groups on the A-benzene ring of Res, thus facilitating its binding with lactoferrin (LF) to form stable complexes through more hydrogen bonds. We prepared LF-Res and LF-Pte complexes, revealed their binding mechanisms by multispectral analysis and molecular docking/dynamics simulations, further evaluated their antioxidant properties via ABTS and DPPH assays and a model of inhibiting apple browning, eventually elucidated their structure-binding-property relationships. This contribution offers a new approach to restore the antioxidant capability of Res, also paves the way to precisely regulate the fascinating bioactivities of hydrophobic compounds by protein-binding in a chemical structure-, especially hydroxyl group-dependent manner.

[Diagnostic Study of Multi-spectral Intelligent Analyzer in Diagnosis of 
the Infiltration Degree of Lung Adenocarcinoma].

BACKGROUND: Lung cancer is one of the most common malignant tumors in the world. The accuracy of intraoperative frozen section (FS) in the diagnosis of lung adenocarcinoma infiltration cannot fully meet the clinical needs. The aim of this study is to explore the possibility of improving the diagnostic efficiency of FS in lung adenocarcinoma by using the original multi-spectral intelligent analyzer. METHODS: Patients with pulmonary nodules who underwent surgery in the Department of Thoracic Surgery, Beijing Friendship Hospital, Capital Medical University from January 2021 to December 2022 were included in the study. The multispectral information of pulmonary nodule tissues and surrounding normal tissues were collected. A neural network model was established and the accuracy of the neural network diagnostic model was verified clinically. RESULTS: A total of 223 samples were collected in this study, 156 samples of primary lung adenocarcinoma were finally included, and a total of 1,560 sets of multispectral data were collected. The area under the curve (AUC) of spectral diagnosis in the test set (10% of the first 116 cases) of the neural network model was 0.955 (95%CI: 0.909-1.000, P<0.05), and the diagnostic accuracy was 95.69%. In the clinical validation group (the last 40 cases), the accuracy of spectral diagnosis and FS diagnosis were both 67.50% (27/40), and the AUC of the combination of the two was 0.949 (95%CI: 0.878-1.000, P<0.05), and the accuracy was 95.00% (38/40). CONCLUSIONS: The accuracy of the original multi-spectral intelligent analyzer in the diagnosis of lung invasive adenocarcinoma and non-invasive adenocarcinoma is equivalent to that of FS. The application of the original multi-spectral intelligent analyzer in the diagnosis of FS can improve the diagnostic accuracy and reduce the complexity of intraoperative lung cancer surgery plan.
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Genetic Dissection of Seasonal Changes in a Greening Plant Based on Time-Series Multispectral Imaging.

Good appearance throughout the year is important for perennial ornamental plants used for rooftop greenery. However, the methods for evaluating appearance throughout the year, such as plant color and growth activity, are not well understood. In this study, evergreen and winter-dormant parents of Phedimus takesimensis and 94 F1 plants were used for multispectral imaging. We took 16 multispectral image measurements from March 2019 to April 2020 and used them to calculate 15 vegetation indices and the area of plant cover. QTL analysis was also performed. Traits such as the area of plant cover and vegetation indices related to biomass were high during spring and summer (growth period), whereas vegetation indices related to anthocyanins were high in winter (dormancy period). According to the PCA, changes in the intensity of light reflected from the plants at different wavelengths over the course of a year were consistent with the changes in plant color and growth activity. Seven QTLs were found to be associated with major seasonal growth changes. This approach, which monitors not only at a single point in time but also over time, can reveal morphological changes during growth, senescence, and dormancy throughout the year.

Extensive assessment of climate change impacts on coastal zone paddy growth using multispectral analysis and hydrodynamic modeling.

Global warming has led to sea levels raise (SLRs) and Malaysia is no exception to this problem. Especially for low-lying coastal areas including the Kuala Kedah area which is active in agricultural and fisheries activities. Farmers have had to bear up to 75 % of yield losses due to seawater breaches since 2016. Therefore, this study is designed to assess the impact of seawater encroachment on water quality through spatial technology approaches and hydrodynamic modeling related to the growth of paddy trees. The study was conducted during two different paddy cultivation seasons namely Season 1-2019 and Season 2-2019 which take place in the southwest and northeast monsoon in Kuala Kedah, Malaysia. The study involved three phases, which are the assessment of salinity and pH concentration levels, the assessment of the health of paddy crops through multispectral image analysis involving three plant indices (VI), namely Normalized Difference Vegetation Index (NDVI), Blue Normalized Difference Vegetation Index (BNDVI) and Normalized Difference Red Edge (NDRE), and finally, the assessment of the impact of SLR through the numerical method in MIKE 21 for hydrodynamic modeling considering two conditions that are without mitigation factor (K1) and with existing mitigating factor (K2). According to the findings, the salinity concentration trend is decreasing across the growth stage during Season 1-2019, whereas it is the contrary during Season 2-2019. It was discovered that during the study period for both tidal events, 73 % of the 44 sampling points in Season 1-2019, as opposed to just 3 % in Season 2-2019, were categorized as Class 4 and Class 5. Even though there were fluctuations throughout the observation, the pH reading is still within the allowed range of 6.5 to 9.0 for the estuary area. Following that, the ANOVA analysis proved that salinity concentration a statistically significant difference with tidal variations and pH levels. Moreover, the multispectral image analysis findings revealed that the VI value was correlated with both the yield and the health of the rice crop, with R-square values of 0.842 compared to 0.706 and 0.575 for NDVI and BNDVI values, respectively. It confirmed that NDRE granted a more accurate and reliable measurements. Additionally, the hydrodynamic simulation results demonstrated that, if the mitigation factors were considered in the modeling, overflow seawater to the mainland could be reduced by up to 20 %, reducing the impact of coastal flooding on the local area as well as the nearby rice cultivation area. Ultimately, these three elements-water quality, vegetation index, and hydrodynamic modeling-can assist in identifying the underlying cause of the problem and develop short and long-term solutions.

Inhibition effect of 1-acetoxy-6α-(2-methylbutyryl)eriolanolide toward soluble epoxide hydrolase: Multispectral analysis, molecular dynamics simulation, biochemical, and in vitro cell-based studies.

Soluble epoxide hydrolase (sEH) serves as a potential target in inflammation-related diseases. Based on the bioactivity-guided separation, a new sesquiterpenoid inulajaponoid A (1) was isolated from Inula japonica with a sEH inhibitory effect, together with five known compounds, such as 1-O-acetyl-6-O-isobutyrylbritannilactone (2), 6ß-hydroxytomentosin (3), 1ß,8ß-dihydroxyeudesma-4(15),11(13)-dien-12,6α-olide (4), (4S,6S,7S,8R)-1-O-acetyl-6-O-(3-methylvaleryloxy)-britannilactone (5), and 1-acetoxy-6α-(2-methylbutyryl)eriolanolide (6). Among them, compounds 1 and 6 were assigned as mixed and uncompetitive inhibitors, respectively. The result of immunoprecipitation (IP)-MS demonstrated the specific binding of compound 6 to sEH in the complex system, which was further confirmed by the fluorescence-based binding assay showing its equilibrium dissociation constant (Kd = 2.43 µM). The detail molecular stimulation revealed the mechanism of action of compound 6 with sEH through the hydrogen bond of amino acid residue Gln384. Furthermore, this natural sEH inhibitor (6) could suppress the MAPK/NF-κB activation to regulate inflammatory mediators, such as NO, TNF-α, and IL-6, which confirmed the anti-inflammatory effect of inhibition of sEH by 6. These findings provided a useful insight to develop sEH inhibitors upon the sesquiterpenoids.

Analysis of relative error in perturbation Monte Carlo simulations of radiative transport.

Significance: Perturbation and differential Monte Carlo (pMC/dMC) methods, used in conjunction with nonlinear optimization methods, have been successfully applied to solve inverse problems in diffuse optics. Application of pMC to systems over a large range of optical properties requires optimal "placement" of baseline conventional Monte Carlo (cMC) simulations to minimize the pMC variance. The inability to predict the growth in pMC solution uncertainty with perturbation size limits the application of pMC, especially for multispectral datasets where the variation of optical properties can be substantial. Aim: We aim to predict the variation of pMC variance with perturbation size without explicit computation of perturbed photon weights. Our proposed method can be used to determine the range of optical properties over which pMC predictions provide sufficient accuracy. This method can be used to specify the optical properties for the reference cMC simulations that pMC utilizes to provide accurate predictions over a desired optical property range. Approach: We utilize a conventional error propagation methodology to calculate changes in pMC relative error for Monte Carlo simulations. We demonstrate this methodology for spatially resolved diffuse reflectance measurements with ±20% scattering perturbations. We examine the performance of our method for reference simulations spanning a broad range of optical properties relevant for diffuse optical imaging of biological tissues. Our predictions are computed using the variance, covariance, and skewness of the photon weight, path length, and collision distributions generated by the reference simulation. Results: We find that our methodology performs best when used in conjunction with reference cMC simulations that utilize Russian Roulette (RR) method. Specifically, we demonstrate that for a proximal detector placed immediately adjacent to the source, we can estimate the pMC relative error within 5% of the true value for scattering perturbations in the range of [-15%,+20%]. For a distal detector placed at ∼3 transport mean free paths relative to the source, our method provides relative error estimates within 20% for scattering perturbations in the range of [-8%,+15%]. Moreover, reference simulations performed at lower (µs'/µa) values showed better performance for both proximal and distal detectors. Conclusions: These findings indicate that reference simulations utilizing continuous absorption weighting (CAW) with the Russian Roulette method and executed using optical properties with a low (µs'/µa) ratio spanning the desired range of µs values, are highly advantageous for the deployment of pMC to obtain radiative transport estimates over a wide range of optical properties.

Classification of Dichotomous Emotional States Using Electrodermal Activity Signals and Multispectral Analysis.

In this work, an analysis based on complex demodulation is proposed to classify dichotomous emotional states using Electrodermal activity (EDA) signals. For this, annotated happy and sad EDA is obtained from an online public database. The sympathetic activity indices, namely Time-varying (TVSymp) and Modified TVSymp, are computed from the reconstructed EDA signal. Further, the derivative of phasic EDA is calculated from the phasic component obtained using the convex optimization (cvxEDA) based EDA decomposition method. Five statistical features are computed from each index and used for the classification. The results of the classification indicate that these features are capable of differentiating happy and sad emotional states with 75% accuracy. This technique could be effective in the identification of clinical disorders associated with happy and sad emotional states.

Review on Multispectral Photoacoustic Analysis of Cancer: Thyroid and Breast.

In recent decades, photoacoustic imaging has been used widely in biomedical research, providing molecular and functional information from biological tissues in vivo. In addition to being used for research in small animals, photoacoustic imaging has also been utilized for in vivo human studies, achieving a multispectral photoacoustic response in deep tissue. There have been several clinical trials for screening cancer patients by analyzing multispectral responses, which in turn provide metabolomic information about the underlying biological tissues. This review summarizes the methods and results of clinical photoacoustic trials available in the literature to date to classify cancerous tissues, specifically of the thyroid and breast. From the review, we can conclude that a great potential exists for photoacoustic imaging to be used as a complementary modality to improve diagnostic accuracy for suspicious tumors, thus significantly benefitting patients' healthcare.