Article
Optics
Victor Colas, Walter Blondel, Gregoire Khairallah, Christian Daul, Marine Amouroux
Summary: This study analyzed the depth distribution of photons detected by SR-DR in skin to understand how they contribute to local physiological and morphological information in acquired spectra. Numerical evidence linking the penetration depth of detected photons to their wavelengths and source-sensor distances was provided, allowing for the decomposition of DR signals related to skin layer contributions.
Article
Optics
Youssef El Hajji, El Houssaine El Rhaleb
Summary: This study investigates the effect of melanin on light propagation inside different types of tissue. Phantoms approximating real tissue and mimicking its reaction to light were constructed. A Monte Carlo simulation was developed to study the intensity distribution of a light beam inside tissues. The study includes different Fitzpatrick skin types and provides intensity distribution and penetration depth in the 200-1000 nm wavelength range.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2023)
Article
Chemistry, Multidisciplinary
Qi Zhou, Brendan M. Wirtz, Tracy H. Schloemer, Michael C. Burroughs, Manchen Hu, Pournima Narayanan, Junrui Lyu, Arynn O. Gallegos, Colette Layton, Danielle J. Mai, Daniel N. Congreve
Summary: UV light is widely used in photochemical reactions, but delivering high-energy photons beyond the surface is challenging. Triplet-triplet annihilation upconversion (TTA-UC) offers a promising solution. In this study, water-compatible UC micelles are fabricated using a nanoencapsulation method, allowing UV photon generation deep into materials. Additionally, this encapsulation method is applicable to a range of UV-emitting UC systems, enabling precise photochemistry at depth.
ADVANCED MATERIALS
(2023)
Article
Optics
L. Di Sieno, E. Ferocino, E. Conca, V Sesta, M. Buttafava, F. Villa, F. Zappa, D. Contini, A. Torricelli, P. Taroni, A. Tosi, A. Pifferi, A. Dalla Mora
Summary: This study demonstrates the performance of a fast-gated digital silicon photomultiplier (SiPM) with an overall active area of 8.6 mm(2), which overcomes the photon collection limitations of established time-gated single-pixel detectors by orders of magnitude, enabling deep investigations within scattering media and high signal-to-noise ratios at late photon arrival times.
Article
Biochemical Research Methods
Sergey M. Zaytsev, Marine Amouroux, Gregoire Khairallah, Alexey N. Bashkatov, Valery V. Tuchin, Walter Blondel, Elina A. Genina
Summary: The study investigated the effect of optical clearing agents on a hybrid model and found an increase in fluorescence reflected intensity, with OCA 2 showing stronger impact possibly due to its effect on the stratum corneum keratin conformation. Additionally, increased light transmittance through the skin was observed, indicating improvement in depth sensitivity of spectroscopy not only due to optical clearing, but also mechanical compression caused by the spectroscopic probe.
JOURNAL OF BIOPHOTONICS
(2022)
Article
Food Science & Technology
Tongtong Zhou, Dong Hu, Dekai Qiu, Shengqi Yu, Yuping Huang, Zhizhong Sun, Xiaolin Sun, Guoquan Zhou, Tong Sun, Hehuan Peng
Summary: This paper presents theoretical and experimental analyses to determine the light penetration depth in apple tissues under spatially modulated illumination. Simulation and practical experiments were carried out to explore the maximum light penetration depths in 'Golden Delicious' apples. The results showed that the simulations produced comparable or slightly larger light penetration depth in apple tissues than the practical experiment.
Article
Optics
Danni Sun, Xin Wang, Min Huang, Qibing Zhu, Jianwei Qin
Summary: In this study, a novel data-driven model based on a long short-term memory network and attention mechanism (LSTM-attention network) combined with spatially resolved diffuse reflectance (SRDR) was proposed for accurately estimating the optical properties of turbid media. Experimental results showed that the proposed LSTM-attention model achieved better estimation accuracy compared to three comparative models, demonstrating the effectiveness of the SRDR combined with the LSTM-attention model in improving the estimation accuracy of the optical properties of turbid media.
Article
Optics
Daria Kurakina, Valeriya Perekatova, Ekaterina Sergeeva, Alexey Kostyuk, Ilya Turchin, Mikhail Kirillin
Summary: This study analyzed the spectral dependence of diffuse reflectance spectroscopy (DRS) probing depth in relation to different source-detector separations (SDSs) and skin parameters. The study found that the probing depth varied between 1-4 mm and different spectral ranges affected the accuracy of oxygen saturation (StO(2)) reconstruction.
LASER PHYSICS LETTERS
(2022)
Article
Optics
Chanjun Sun, Ben Aernouts, Wouter Saeys
Summary: This research investigates the mismatches between measurements and simulations by studying the influences from light source and the incident and detection angle on diffuse reflectance profiles. After reducing the mismatches caused by these factors, metamodels linking optical properties with diffuse reflectance profiles were built based on measured and simulated data, both achieving high prediction performance with R-2 values above 0.96, allowing for the creation of simulation-based metamodel applicable to different measurement configurations.
Article
Engineering, Biomedical
Vysakh Vasudevan, Sujatha Narayanan Unni
Summary: Spatially resolved diffuse reflectance spectroscopy (SRDRS) is a non-invasive optical technique that aids in clinical diagnosis by collecting backscattered light from multi-layered tissue. This study utilizes finite element models to study light tissue interactions and extract tissue optical parameters, showing agreement with the expected tissue parameters through inverse modeling.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING
(2022)
Article
Physics, Multidisciplinary
Aaram J. Kim, Katharina Lenk, Jiajun Li, Philipp Werner, Martin Eckstein
Summary: We propose a diagrammatic Monte Carlo approach for quantum impurity models, which is a generalization of the strong-coupling expansion for fermionic impurity models. The algorithm is based on a self-consistently computed three-point vertex and a stochastically sampled four-point vertex and provides numerically exact results in a wide parameter regime. The performance of the algorithm is demonstrated with applications to a spin-boson model representing an emitter in a waveguide. The spatial distribution of the photon density around the emitter is also discussed.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Maarten Van Damme, Laurens Vanderstraeten
Summary: In this study, we introduce a method based on matrix product states (MPS) to compute spectral functions of (quasi-) one-dimensional spin chains directly in momentum space. By simulating the time evolution and working with the momentum superposition of a window MPS, we can achieve accurate spectral functions with smaller entanglement growth and relatively small bond dimension. The method is applied to compute spectral lineshapes of the gapless XXZ chain and the square-lattice J1 ??? J2 Heisenberg model on a six-leg cylinder.
Article
Computer Science, Software Engineering
Rohan Sawhney, Dario Seyb, Wojciech Jarosz, Keenan Crane
Summary: This paper introduces a method for solving partial differential equations with spatially varying coefficients. By extending the walk on spheres algorithm from volumetric rendering to variable-coefficient problems, the exact solution for problems with detailed geometry and intricate coefficients can be obtained. This method does not require discretization of the problem and offers advantages such as unbiased Monte Carlo estimators and the ability to evaluate the solution at any point without solving a global system of equations.
ACM TRANSACTIONS ON GRAPHICS
(2022)
Article
Chemistry, Multidisciplinary
Jacob Pettine, Paolo Maioli, Fabrice Vallee, Natalia Del Fatti, David J. Nesbitt
Summary: We investigated the effects of nanoscale structure on the femtosecond dynamics of gold nanoparticles using time-, angle-, and energy-resolved photoemission spectroscopy. We found that nanoparticles as small as 10 nm serve as excellent platforms for studying intrinsic metal dynamics.
Article
Multidisciplinary Sciences
Te Ma, Tetsuya Inagaki, Satoru Tsuchikawa
Summary: This study developed a time-resolved transmittance spectroscopic method to validate the light scattering changing characteristics in kiwifruit during shelf-life and in cold storage conditions, and successfully formulated a mathematical model to classify the stages of kiwifruit softening.
SCIENTIFIC REPORTS
(2023)
Article
Biochemical Research Methods
Dieter Oelkrug, Barbara Boldrini, Karsten Rebner
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2017)
Article
Instruments & Instrumentation
Dieter Oelkrug, Manfred Brun, Peter Hubner, Karsten Rebner, Barbara Boldrini, Rudolf Kessler
APPLIED SPECTROSCOPY
(2013)
Article
Engineering, Chemical
Phillip Trefz, Barbara Boldrini, Rudolf W. Kessler, Stefan Loebbecke
CHEMIE INGENIEUR TECHNIK
(2010)
Article
Chemistry, Applied
Andrey Bogomolov, Stefan Dietrich, Barbara Boldrini, Rudolf W. Kessler
Article
Instruments & Instrumentation
Simo Huotari, Barbara Boldrini, Veijo Honkimaeki, Pekka Suortti, Wolf Weyrich
JOURNAL OF SYNCHROTRON RADIATION
(2009)
Article
Optics
Karsten Rebner, Michael Schmitz, Barbara Boldrini, Alwin Kienle, Dieter Oelkrug, R. W. Kessler
Article
Biochemical Research Methods
Tobias Drieschner, Edwin Ostertag, Barbara Boldrini, Anita Lorenz, Marc Brecht, Karsten Rebner
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2020)
Article
Biochemical Research Methods
Mona Stefanakis, Anita Lorenz, Joerg W. Bartsch, Miriam C. Bassler, Alexandra Wagner, Marc Brecht, Axel Pagenstecher, Jens Schittenhelm, Barbara Boldrini, Sabrina Hakelberg, Susan Noell, Christopher Nimsky, Marcos Tatagiba, Rainer Ritz, Karsten Rebner, Edwin Ostertag
Summary: Characterization of brain tumors through multimodal optical spectroscopy can provide valuable chemical and morphological information for neuropathological diagnosis. Formalin fixation affects tissue stability and slightly improves classification models based on optical spectroscopy data of brain tumors. These spectroscopic methods are appropriate additional contrasts in neuropathological diagnosis and can be integrated into clinical workflows even after formalin fixation.
JOURNAL OF SPECTROSCOPY
(2021)
Article
Chemistry, Analytical
Mohammad Al Ktash, Mona Stefanakis, Barbara Boldrini, Edwin Ostertag, Marc Brecht
Summary: A laboratory prototype for hyperspectral imaging in the UV region was developed to characterize active pharmaceutical ingredients in tablets. The prototype successfully differentiated drug samples using principal component analysis, showing potential for large-scale application. The rugged design of the prototype opens new possibilities for further development of the technique.
Article
Biochemical Research Methods
Barbara Boldrini, Edwin Ostertag, Karsten Rebner, Dieter Oelkrug
Summary: The article investigates the influence of microscope parameters on pinhole-assisted Raman depth profiles in different refractive media. Low magnification, low aperture, and small pinholes result in easily interpretable results while high magnification paired with high aperture is necessary for sub-micrometer resolution. Signal intensities and shapes vary with position relative to the sample surface in refractive media.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2021)
Review
Chemistry, Applied
Barbara Boldrini, Waltraud Kessler, Karsten Rebner, Rudolf W. Kessler
JOURNAL OF NEAR INFRARED SPECTROSCOPY
(2012)
Proceedings Paper
Engineering, Biomedical
Edwin Ostertag, Barbara Boldrini, Sabrina Luckow, Rudolf W. Kessler
BIOPHOTONICS: PHOTONIC SOLUTIONS FOR BETTER HEALTH CARE III
(2012)
Article
Chemistry, Physical
B Boldrini, E Cavalli, A Painelli, F Terenziani
JOURNAL OF PHYSICAL CHEMISTRY A
(2002)