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Universal existence of fluorescent carbon dots in beer and assessment of their potential toxicity
摘要： Nanosized materials may produce adverse physiological effects or potential health risks due to their unique physical and chemical properties. Herein, the universal presence of fluorescent carbon dots (CDs) in commercial beers was confirmed through a systematic survey. The beer CDs were roughly spherically shaped in appearance and emitted bright blue fluorescence under ultraviolet light with quantum yields (QYs) ranging from 1.42% to 3.92%. Furthermore, digestion, biodistribution, and cytotoxicity assessments of CDs from Snow beer were conducted as an example. The CDs were significantly quenched during in vitro digestion. The dynamic distribution of CDs in mice showed that they easily accumulated in the intestine and liver, and more importantly, the beer CDs were found in the brain, which indicated that they were able to cross the blood–brain barrier. Acute toxicity of the beer CDs was evaluated using BALB/c mice, and the results revealed that the biochemical parameters of mice after administration of a single dose of 2 g kg?1 body weight were almost same as those of the control groups. Histological analysis showed no obvious organ damage in the tested mice. The in vitro results indicated that CDs dispersed onto both the cell membrane and the cytoplasm of MC3T3-E1 cells, alter the cell cycle progression, and caused cell apoptosis at high doses. This work reports the potential risk of CDs in beer and provides valuable information regarding CDs in food.
关键词： beer,cytotoxicity,biodistribution,Carbon dots,digestion
更新于2025-09-23 15:23:52
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Evanescent field ratio enhancement of a modified ridge waveguide structure for methane gas sensing application
摘要： We presented a significant improvement of the evanescent field ratio in a ridge waveguide modified into a dual hybrid plasmonic waveguide by tapering the middle section of the waveguide and placing a gold layer on both sides with a sub-wavelength gap. The waveguide geometry is optimized at 3.392 μm which is an absorption line of methane gas. The proposed waveguide scheme provides a large waveguide cross-section which facilitates a light with an enhanced evanescent field in the middle. To validate the study, the evanescent field ratio, propagation loss, confinement factor and electric field distribution of the waveguide is studied via the finite element method. Additionally, the device is also proposed. An elevated evanescent field ratio of 0.74 is obtained with a propagation loss of ~0.7 dB/μm. The sensitivity of 0.0715 (mW/gas conc.) is obtained for the proposed waveguide scheme by calculating the decay in transmission power due to absorption by the gas in the medium.
关键词： Evanescent field absorption gas sensor,3.392 μm,methane,mid-infrared,Lambert-Beer law
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Analytical Assessment of the Modulation Depth of Photoplethysmographic Signal Based on the Modified Beer-Lambert Law
摘要： The model for estimation of the amplitude modulation depth of photoplethysmographic (PPG) signal based on the modified Beer-Lambert law was developed. It was analytically confirmed that the modulation depth of PPG signal depends on the wavelength and illumination geometry. The modulation depth is directly proportional to the distance between the light source and the detector. The sensitivity of green light (525 nm) to blood volume changes is approximately 6-9 times greater than that for red (640 nm) and IR (805 nm) light. It was found that in case of green light, the main contribution to the modulation of PPG signal is made by absorption coefficient changes while in case of red and IR light, the modulation is mainly caused by scattering coefficient changes.
关键词： blood volume,modulation depth,photoplethysmography,amplitude modulation,modified Beer-Lambert law
更新于2025-09-23 15:19:57
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[IEEE 2019 3rd International Conference on Imaging, Signal Processing and Communication (ICISPC) - Singapore (2019.7.27-2019.7.29)] 2019 3rd International Conference on Imaging, Signal Processing and Communication (ICISPC) - A High-Efficiency Diver-to-Diver Optical Communication System
摘要： Even seemingly simple systems can produce complex dynamics, which leads management professionals to develop tools for training, monitoring, and improving performance. Management simulators provide useful insights about human behavior and interactions, while computational and informational decision support tools offer opportunities to reduce inconsistencies, errors, and non-optimal human choices, particularly for complex systems that involve multiple decision makers, uncertainty, variability, and time. We use the context of a popular management simulator that teaches students about the bullwhip effect (i.e., the beer distribution game) to explore an integrated decision analytic, control theory, and system dynamics approach to the game that recognizes the value of available (imperfect) information and considers the value of perfect information to provide the optimal strategy. Using a discrete event simulation, we characterize optimal decisions and overall team scores for the situation of actual available information and perfect information. We describe our implementation of the strategy in the ?eld to win the 2007 beer game world championship played at the 25th conference of the International System Dynamics Society. This paper seeks to demonstrate that better understanding of the system and use of available information leads to signi?cantly lower expected costs than identi?ed in prior studies. Understanding complex systems and using information optimally may increase system stability and signi?cantly improve performance, in some cases even without better information than already available.
关键词： system dynamics,Value of information,beer distribution game,decision analysis,control theory
更新于2025-09-23 15:19:57
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[IEEE 2019 International Topical Meeting on Microwave Photonics (MWP) - Ottawa, ON, Canada (2019.10.7-2019.10.10)] 2019 International Topical Meeting on Microwave Photonics (MWP) - Simultaneous Measurement of Doppler-Frequency-Shift and Angle-of-Arrival of Microwave Signals for Automotive Radars
摘要： Even seemingly simple systems can produce complex dynamics, which leads management professionals to develop tools for training, monitoring, and improving performance. Management simulators provide useful insights about human behavior and interactions, while computational and informational decision support tools offer opportunities to reduce inconsistencies, errors, and non-optimal human choices, particularly for complex systems that involve multiple decision makers, uncertainty, variability, and time. We use the context of a popular management simulator that teaches students about the bullwhip effect (i.e., the beer distribution game) to explore an integrated decision analytic, control theory, and system dynamics approach to the game that recognizes the value of available (imperfect) information and considers the value of perfect information to provide the optimal strategy. Using a discrete event simulation, we characterize optimal decisions and overall team scores for the situation of actual available information and perfect information. We describe our implementation of the strategy in the ?eld to win the 2007 beer game world championship played at the 25th conference of the International System Dynamics Society. This paper seeks to demonstrate that better understanding of the system and use of available information leads to signi?cantly lower expected costs than identi?ed in prior studies. Understanding complex systems and using information optimally may increase system stability and signi?cantly improve performance, in some cases even without better information than already available.
关键词： system dynamics,decision analysis,beer distribution game,Value of information,control theory
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Quantum Sensing of Absorbance and the Beer-Lambert Law
摘要： Optical quantum sensing strategies that utilise features of quantum states of light have implications for precision measurement in areas as wide ranging as such as gravitational wave sensing and biological imaging. Optical absorption estimation is the task of estimating the transmission parameter η which is defined by the ratio of input, (cid:1835)(cid:3036)(cid:3041), to output, (cid:1835)(cid:3042)(cid:3048)(cid:3047), intensity of light from a sample of interest ((cid:1835)(cid:3042)(cid:3048)(cid:3047) = (cid:2015)(cid:1835)(cid:3036)(cid:3041)). The optimal quantum strategy provides a quantum advantage (per incident photon) of 1/(1-η) over the best classical strategy. This technique has been demonstrated experimentally in single parameter estimation and imaging scenarios. Here, we expand on recent theoretical and experimental results and investigate the quantum advantage available for absorbance estimation, where the parameter of interest, α, is the loss per unit length parameter used in the Beer-Lambert law: (cid:1835)(cid:3042)(cid:3048)(cid:3047) = exp(?α (cid:1838))(cid:1835)(cid:3036)(cid:3041), where (cid:1838) is the length of the sample. We further show that the tunability of (cid:1838) allows for maximisation of the Fisher information. Furthermore, we show that the optimal length, (cid:1838)(cid:3042)(cid:3043)(cid:3047), that provides the largest Fisher information is a function of the photon number statistics of the input optical state, and as such is different for optimal quantum and classical schemes. When both strategies are operating at (cid:1838)(cid:3042)(cid:3043)(cid:3047), the quantum advantage is limited to a fixed value of 1.2 for all α, contrary to absorption estimation where the quantum advantage can be arbitrarily large. This demonstrates that an improvement in the precision of the sensor can be performed by classical means, drastically reducing the advantage offered by quantum strategies. We find the impact of (cid:1838)(cid:3042)(cid:3043)(cid:3047) is analogous to previous work looking at multipass strategies for phase estimation. Using the setup depicted in Figure 1, we experimentally show that for single photon Fock states, optimising over (cid:1838) does indeed yield higher precision estimates of absorbance. This work has implications for a range of experiments employing the Beer-Lambert law, and can be expanded to include other experimental parameters such as loss, dark counts, and noisy laser sources.
关键词： Absorbance,Quantum Advantage,Fisher Information,Beer-Lambert Law,Quantum Sensing
更新于2025-09-11 14:15:04
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MULTISPECTRAL IMAGING SYSTEM FOR QUANTITATIVE ASSESSMENT OF TRANSCUTANEOUS BLOOD OXYGEN SATURATION
摘要： This paper presents the use of Extended Modified Lambert Beer (EMLB) model for quantification of transcutaneous blood oxygen saturation (StO2) via a noninvasive approach. Continuous wave (CW) reflectance spectroscopy system is employed for measurement of intensity reflected from left index finger of an Asian nonsmoking volunteer at resting condition. Multispectral images captured in the wavelength range of 520 ? 600 nm at an interval of 10 nm are mathematically analyzed and fitted using the developed fitting algorithm to give the best estimation of StO2. The result from this preliminary study revealed a mean StO2 value of 75 ± 5% for the participating individual, which value agreed considerably well with that presented in previous works. This work concluded that the developed spectroscopy system and quantification technique can potentially be used as an alternative means to clinical assessment of wound healing progress.
关键词： Transcutaneous blood oxygen saturation,reflectance spectroscopy,Extended Modified Lambert Beer model,skin oximetry
更新于2025-09-11 14:15:04
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Symmetric and asymmetric discrimination of bosonic loss: Toy applications to biological samples and photodegradable materials
摘要： We consider quantum discrimination of bosonic loss based on both symmetric and asymmetric hypothesis testing. In both approaches, an entangled resource is able to outperform any classical strategy based on coherent-state transmitters in the regime of low photon numbers. In the symmetric case, we then consider the low-energy detection of bacterial growth in culture media. Assuming an exponential growth law for the bacterial concentration and the Beer-Lambert law for the optical transmissivity of the sample, we find that the use of entanglement allows one to achieve a much faster detection of growth with respect to the use of coherent states. This performance is also studied by assuming an exponential photo degradable model, where the concentration is reduced by increasing the number of photons irradiated over the sample. This investigation is then extended to the readout of classical information from suitably designed photodegradable optical memories.
关键词： coherent-state transmitters,optical memories,bacterial growth,entangled resource,quantum discrimination,bosonic loss,Beer-Lambert law,photodegradable model,optical transmissivity,symmetric and asymmetric hypothesis testing
更新于2025-09-10 09:29:36
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Application of the Beer-Lambert Model to Attenuation of Photosynthetically Active Radiation in a Shallow, Eutrophic Lake
摘要： Models of primary production in aquatic systems must include a means to estimate subsurface light. Such models often use the Beer–Lambert law, assuming exponential attenuation of light with depth. It is further assumed that the diffuse attenuation coef?cient may be estimated as a summation of scattering/absorbing constituent concentrations multiplied by their respective speci?c attenuation coef?cients. While theoretical deviations from these assumptions have been documented, it is useful to consider the empirical performance of this common approach. Photosynthetically active radiation (PAR) levels and water quality conditions were recorded weekly from six to eight monitoring stations in western Lake Erie between 2012 and 2016. Exponential PAR extinction models yielded a mean attenuation coef?cient of 1.55 m (interquartile range = 0.74–1.90 m). While more complex light attenuation models are available, analysis of residuals indicated that the simple Beer–Lambert model is adequate for shallow, eutrophic waters similar to western Lake Erie (R2 > 0.9 for 96% of samples). Three groups of water quality variables were predictive of PAR attenuation: total and nonvolatile suspended particles, dissolved organic substances (dissolved organic carbon and chromophoric dissolved organic matter), and organic solids (volatile suspended solids and chlorophyll). Multiple regression models using these variables predicted 3–90% of the variability in PAR attenuation, with a median adjusted R2 = 0.86. Explanatory variables within these groups may substitute for each other while maintaining similar model performance, indicating that various combinations of water quality variables may be useful to predict PAR attenuation, depending on availability within a model framework or monitoring program.
关键词： water quality,Lake Erie,PAR attenuation,photosynthetically active radiation,Beer–Lambert law
更新于2025-09-09 09:28:46
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Beer’s law - why absorbance depends (almost) linearly on concentration
摘要： Beer’s law assumes a strictly linear dependence of the absorbance from concentration. Usually, chemical interactions and instrumental imperfection are made responsible for experimental deviations from this linearity. In this contribution we show that even in the absence of such interactions and instrumental errors, absorbance should be only approximately proportional to concentration. This can be derived from the quadratic dependence of the complex refractive index, and, by that, of the molar attenuation coefficient, from the dielectric constant and its frequency dispersion. Following dispersion theory, it is the variation of the real and the imaginary part of the dielectric function that depends linearly on concentration in the absence of interactions between the oscillators. We show that this linear correlation translates into a linear dependence of the absorbance for low concentrations or molar oscillator strengths based on an approximation provided by Lorentz in 1906. Accordingly, Beer’s law can be derived from dispersion theory.
关键词： Dispersion,Absorbance,Beer’s law
更新于2025-09-04 15:30:14