Article
Oncology
Danielle E. Desa, Wencheng Wu, Robert M. Brown, Edward B. Brown, Robert L. Hill, Bradley M. Turner, Edward B. Brownn
Summary: This study assessed the impact of neoadjuvant chemotherapy on tumor collagen in breast cancer patients. The results showed that chemotherapy affects tumor extracellular collagen in a subtype-specific manner and alters some prognostic signatures. This may have implications for the clinical utility of these signatures.
Article
Dermatology
Mercedes Sendin-Martin, Jasmine Posner, Ucalene Harris, Matthew Moronta, Julian Conejo-Mir Sanchez, Sushmita Mukherjee, Milind Rajadhyaksha, Kivanc Kose, Manu Jain
Summary: Basal cell carcinoma (BCC) is the most common skin cancer, and non-invasive in vivo technologies such as multiphoton microscopy (MPM) can aid in diagnosing and prognosticating these tumors. This study explored the potential of MPM to differentiate collagen changes associated with different BCC subtypes compared to normal skin structures and benign lesions. The results showed that collagen distribution is more aligned surrounding BCCs nests compared to normal structures and benign lesions, and collagen is orientated more parallelly surrounding indolent BCC subtypes versus those with aggressive behavior.
EXPERIMENTAL DERMATOLOGY
(2023)
Article
Biochemical Research Methods
Radu Hristu, Stefan G. Stanciu, Adrian Dumitru, Bogdan Paun, Iustin Floroiu, Mariana Costache, George A. Stanciu
Summary: Second harmonic generation (SHG) microscopy is a powerful tool for tissue characterization and diagnostics in medicine, particularly for mapping collagen structure for diagnosis. The study found that H&E staining affects the extraction and use of image parameters specific to polarization-resolved SHG microscopy, potentially leading to different analysis results and impacting diagnostic accuracy.
BIOMEDICAL OPTICS EXPRESS
(2021)
Article
Orthopedics
A. N. Jambor, E. M. Shelton, R. Kijowski, C. R. Henak, P. J. Campagnola
Summary: The study effectively demonstrated the disorganized collagen structure resulting from trypsin and collagenase degradation in cartilage, with collagenase showing the most significant effect. Application of a LD model successfully classified control and degraded tissues, indicating distinct activity of these enzymes on collagen assembly. Results from human cartilage suggested that collagenase effects were more representative of in vivo degeneration, emphasizing the potential of using high-resolution SHG and optical scattering as an earlier diagnostic tool for OA.
OSTEOARTHRITIS AND CARTILAGE
(2021)
Article
Optics
Alexander W. A. Murphy, Zichen Liu, Andrey V. Gorbach, Adelina Ilie, Ventsislav K. Valev
Summary: The study presents the first hyperspectral multiphoton analysis of densely-packed stacks of twisted and/or fused WS2 nanosheets, known as nanomesh, which exhibits scalable, efficient, and broadband optical properties due to double resonances induced by internal defects. This makes the nanomesh a prime candidate for integration into quantum optical technologies.
LASER & PHOTONICS REVIEWS
(2021)
Article
Biophysics
Mehdi Alizadeh, Serguei Krouglov, Virginijus Barzda
Summary: This study aims to elucidate the factors affecting the intensity of second-harmonic generation (SHG) in biological tissues and the ratios of achiral (R) and chiral (C) nonlinear susceptibility tensor components. The results show a strong dependence of SHG intensity on the organization of parallel/anti-parallel fibers, as well as the fiber chirality, tilting, and crossing. The computational modeling provides a basis for interpreting polarimetric SHG microscopy images.
BIOPHYSICAL JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Wentao Wu, Shuo Tang
Summary: This study presents theoretical analyses of harmonic generation with a focused Gaussian beam. Analytical solutions are obtained for the integral of the phase-matching factor which can be applied to various focusing and sample conditions. The study shows that reasonable SHG and THG efficiency can be excited near interfaces or for thin samples with normal dispersion. An optimization process of the confocal parameter is proposed based on the properties of the sample. Multimodal label-free imaging combining SHG, THG, and two-photon excitation fluorescence is demonstrated on biological samples for acquiring complementary information about tissues.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2023)
Review
Engineering, Multidisciplinary
Thomas Ebbinghaus, Gregor Lang, Thomas Scheibel
Summary: Biomimicry applies principles of natural materials, processes, and structures to technology. This review discusses the two strategies of biomimicry: bottom-up and top-down approaches, using biomimetic polymer fibers and spinning techniques as examples. Bottom-up biomimicry helps gain fundamental knowledge on biological systems for technological advancements, while top-down biomimicry seeks solutions from natural role models. Examples like silk and collagen fibers, spider webs, animal hair, and tissue structures are presented. The review also provides an overview of biomimetic filter technologies, textiles, and tissue engineering.
BIOINSPIRATION & BIOMIMETICS
(2023)
Article
Physics, Applied
Xiyuan Lu, Kartik Srinivasan
Summary: This paper reconsiders the mechanism of photoinduced SHG and proposes a new hypothesis that photoinduced SHG is a FWM-mediated dc Kerr optical parametric oscillation or amplification process. This hypothesis can explain the threshold behavior observed in experiments and predicts unconventional light amplification. Experiments in silicon nitride microresonators verify this hypothesis, and the physical implications of this work are discussed for various platforms and future directions.
PHYSICAL REVIEW APPLIED
(2021)
Article
Materials Science, Multidisciplinary
Christian Jonin, Estelle Salmon, Zacharie Behel, Faheem Ahmed, Mohammed Benali Kanoun, Chawki Awada, Pierre-Francois Brevet
Summary: In this study, second harmonic generation (SHG) and multiphoton excited photoluminescence (MEPL) were observed in retro-reflection mode from a 22 nm diameter anatase TiO2 nanoparticle powder. The relative contribution of SHG and MEPL depends on the conditions of photo-excitation, particularly the fundamental wavelength and the focal point depth location. Depth intensity profiles of SHG and MEPL differ significantly, with SHG profiles being narrower than that of MEPL.
Article
Optics
M. B. Hild, M. Safaeisadegh, A. Lindinger
Summary: Spatial and temporal laser pulse shaping was used for measuring two-photon excited fluorescence of dyes with tailored pulses in two adjacent ranges of the laser spectrum. Selective phase shaping of the pulses led to increased fluorescence contrasts between different dyes and spatially localized fluorescence in the overlap region. The developed method can be applied for more complex two-photon excited fluorescence structures with valuable perspectives for optical and biophotonic applications.
Article
Chemistry, Physical
Ting-Yu Yen, Meng-Ting Shih, Long-Fu Song, Kung-Ming Hung, Kuang-Yao Lo
Summary: The evaluation of dopant concentration is crucial in advanced field-effect transistor fabrication. This study utilizes the unique characteristics of boron traps in in-situ boron doped Si ultrathin film (DSUTF) to examine the evolution of electric field using time-dependent second harmonic generation (TD-SHG). The presence of oxygen molecules weakens the electric field, leading to a reduction in SHG intensity. Furthermore, there is a strong monotonic correlation between the boron induced electric field and the dopant concentration.
SURFACES AND INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Fan Yang, Cristian Ciraci
Summary: We present a theoretical study on second-harmonic generation from a singular metasurface, which strongly interacts with incident light and generates intense surface polarization, resulting in the generation of second-harmonic field. By using transformation optics, the calculation of nonlinear optical response is simplified, and the dependence on the incident angle is weak, making it potentially useful for all-angle harmonic generation. Furthermore, we investigate the symmetry dependence of second-harmonic generation in the far field and demonstrate an enhanced conversion efficiency under normal incidence by breaking the surface inversion symmetry.
Article
Biochemical Research Methods
Alan E. Woessner, Kyle P. Quinn
Summary: Collagen fibers play a vital role in various tissues, but accurate segmentation is challenging due to variable imaging depths. This study employed a U-Net convolutional neural network for precise segmentation of collagen fibers and demonstrated superior performance compared to other thresholding techniques, particularly at deeper imaging depths.
JOURNAL OF BIOPHOTONICS
(2022)
Article
Optics
Artemii Tishchenko, Thomas Geernaert, Nathalie Vermeulen, Francis Berghmans, Tigran Baghdasaryan
Summary: This study demonstrates for the first time the possibility of achieving simultaneous modal phase and group velocity matching in silica microstructured optical fibers, utilizing the LP01(omega) and LP02(2 omega) modes, which can be used for waveguide-based SHG generation with ultrashort pulses.