Kiwifruit Firmness by near Infrared Light Scattering

1997 ◽  
Vol 5 (2) ◽  
pp. 83-89 ◽  
Author(s):  
V.A. McGlone ◽  
H. Abe ◽  
S. Kawano
Keyword(s):  
Near Infrared ◽  
Laser Light ◽  
Scattered Light ◽  
Incident Beam ◽  
Infrared Light ◽  
Power Coefficient ◽  
Fruit Firmness ◽  
Rupture Force ◽  
Inverse Power Law ◽  
Intensity Changes

Kiwifruit firmness was estimated by scattering 864 nm laser light through the fruit to exiting angles at 20 to 55° around the circumference of the fruit from the incident beam. The intensity of scattered light emitted from the fruit increased with decreasing firmness, especially at larger angles. The intensity changes were modelled using an inverse power law relationship between the intensity and a distance factor D = sin(θ / 2), where θ is the exiting angle. With increasing firmness the proportionality constant S increases and the power coefficient of D, – n, decreases. The logarithm of S gave the best linear regression results against stiffness and rupture force; two standard measures of fruit firmness, with R2 values of 83% and 79%, respectively.

Heat Generation in Laser Irradiated Tissue

1989 ◽  
Vol 111 (1) ◽  
pp. 62-68 ◽  
Author(s):  
A. J. Welch ◽  
J. A. Pearce ◽  
K. R. Diller ◽  
G. Yoon ◽  
W. F. Cheong
Keyword(s):  
Heat Source ◽  
Heat Generation ◽  
Near Infrared ◽  
Scattered Light ◽  
Incident Beam ◽  
Accurate Estimation ◽  
Optical Parameters ◽  
Infrared Wavelengths ◽  
Improved Model

Many medical applications involving lasers rely upon the generation of heat within the tissue for the desired therapeutic effect. Determination of the absorbed light energy in tissue is difficult in many cases. Although UV wavelengths of the excimer laser and 10.6 μm wavelength of the CO2 laser are absorbed within the first 20 μm of soft tissue, visible and near infrared wavelengths are scattered as well as absorbed. Typically, multiple scattering is a significant factor in the distribution of light in tissue and the resulting heat source term. An improved model is presented for estimating heat generation due to the absorption of a collimated (axisymmetric) laser beam and scattered light at each point r and z in tissue. Heat generated within tissue is a function of the laser power, the shape and size of the incident beam and the optical properties of the tissue at the irradiation wavelength. Key to the calculation of heat source strength is accurate estimation of the light distribution. Methods for experimentally determining the optical parameters of tissue are discussed in the context of the improved model.

scholarly journals Near infrared light fluorescence imaging-guided biomimetic nanoparticles of extracellular vesicles deliver indocyanine green and paclitaxel for hyperthermia combined with chemotherapy against glioma

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Meng Wang ◽  
Chen-Yan Lv ◽  
Shu-Ang Li ◽  
Jun-Kuan Wang ◽  
Wen-Zheng Luo ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Indocyanine Green ◽  
Extracellular Vesicles ◽  
Near Infrared ◽  
Laser Light ◽  
Cell Counting ◽  
Infrared Light ◽  
Acetoxymethyl Ester ◽  
Nude Mouse Model ◽  
U251 Cells

Abstract Background We investigated the therapeutic effect of targeting extracellular vesicles (EVs) loaded with indocyanine green (ICG) and paclitaxel (PTX) on glioma. Methods Raw264.7 cells were harvested to extract EVs for the preparation of ICG/PTX@RGE-EV by electroporation and click chemistry. We evaluated the success of modifying Neuropilin-1 targeting peptide (RGE) on the EV membrane of ICG/PTX@RGE-EV using super-resolution fluorescence microscopy and flow cytometry. Spectrophotometry and high performance liquid chromatography (HPLC) were implemented for qualitative and quantitative analysis of the ICG and PTX loaded in EVs. Photothermal properties of the vesicles were evaluated by exposing to 808-nm laser light. Western blot analysis, cell counting kit 8 (CCK-8), Calcein Acetoxymethyl Ester/propidium iodide (Calcein-AM/PI) staining, and flow cytometry were utilized for assessing effects of vesicle treatment on cellular behaviors. A nude mouse model bearing glioma was established to test the targeting ability and anti-tumor action of ICG/PTX@RGE-EV in vivo. Results Under exposure to 808-nm laser light, ICG/PTX@RGE-EV showed good photothermal properties and promotion of PTX release from EVs. ICG/PTX@RGE-EV effectively targeted U251 cells, with activation of the Caspase-3 pathway and elevated apoptosis in U251 cells through chemotherapy combined with hyperthermia. The anti-tumor function of ICG/PTX@RGE-EV was confirmed in the glioma mice via increased accumulation of PTX in the ICG/PTX@RGE-EV group and an increased median survival of 48 days in the ICG/PTX@RGE-EV group as compared to 25 days in the PBS group. Conclusion ICG/PTX@RGE-EV might actively target glioma to repress tumor growth by accelerating glioma cell apoptosis through combined chemotherapy-hyperthermia. Graphic Abstract

Fluorescent proteins for in vivo imaging, where's the biliverdin?

2020 ◽  
Vol 48 (6) ◽  
pp. 2657-2667
Author(s):  
Felipe Montecinos-Franjola ◽  
John Y. Lin ◽  
Erik A. Rodriguez
Keyword(s):  
Hydrogen Peroxide ◽  
In Vivo Imaging ◽  
Near Infrared ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Fluorescent Imaging ◽  
Infrared Light ◽  
Red Fluorescent Protein ◽  
Color Palette

Noninvasive fluorescent imaging requires far-red and near-infrared fluorescent proteins for deeper imaging. Near-infrared light penetrates biological tissue with blood vessels due to low absorbance, scattering, and reflection of light and has a greater signal-to-noise due to less autofluorescence. Far-red and near-infrared fluorescent proteins absorb light >600 nm to expand the color palette for imaging multiple biosensors and noninvasive in vivo imaging. The ideal fluorescent proteins are bright, photobleach minimally, express well in the desired cells, do not oligomerize, and generate or incorporate exogenous fluorophores efficiently. Coral-derived red fluorescent proteins require oxygen for fluorophore formation and release two hydrogen peroxide molecules. New fluorescent proteins based on phytochrome and phycobiliproteins use biliverdin IXα as fluorophores, do not require oxygen for maturation to image anaerobic organisms and tumor core, and do not generate hydrogen peroxide. The small Ultra-Red Fluorescent Protein (smURFP) was evolved from a cyanobacterial phycobiliprotein to covalently attach biliverdin as an exogenous fluorophore. The small Ultra-Red Fluorescent Protein is biophysically as bright as the enhanced green fluorescent protein, is exceptionally photostable, used for biosensor development, and visible in living mice. Novel applications of smURFP include in vitro protein diagnostics with attomolar (10−18 M) sensitivity, encapsulation in viral particles, and fluorescent protein nanoparticles. However, the availability of biliverdin limits the fluorescence of biliverdin-attaching fluorescent proteins; hence, extra biliverdin is needed to enhance brightness. New methods for improved biliverdin bioavailability are necessary to develop improved bright far-red and near-infrared fluorescent proteins for noninvasive imaging in vivo.

Catalyst Halogenation Enables Rapid and Efficient Polymerizations with Visible to Near-Infrared Light

2020 ◽  
Author(s):  
Alex Stafford ◽  
Dowon Ahn ◽  
Emily Raulerson ◽  
Kun-You Chung ◽  
Kaihong Sun ◽  
...  
Keyword(s):  
Near Infrared ◽  
Transient Absorption ◽  
Reaction Times ◽  
Infrared Light ◽  
Structure Property ◽  
Light Emitting ◽  
Structure Property Relationships ◽  
Nir Light ◽  
Light Intensities ◽  
Emission Quenching

Driving rapid polymerizations with visible to near-infrared (NIR) light will enable nascent technologies in the emerging fields of bio- and composite-printing. However, current photopolymerization strategies are limited by long reaction times, high light intensities, and/or large catalyst loadings. Improving efficiency remains elusive without a comprehensive, mechanistic evaluation of photocatalysis to better understand how composition relates to polymerization metrics. With this objective in mind, a series of methine- and aza-bridged boron dipyrromethene (BODIPY) derivatives were synthesized and systematically characterized to elucidate key structure-property relationships that facilitate efficient photopolymerization driven by visible to NIR light. For both BODIPY scaffolds, halogenation was shown as a general method to increase polymerization rate, quantitatively characterized using a custom real-time infrared spectroscopy setup. Furthermore, a combination of steady-state emission quenching experiments, electronic structure calculations, and ultrafast transient absorption revealed that efficient intersystem crossing to the lowest excited triplet state upon halogenation was a key mechanistic step to achieving rapid photopolymerization reactions. Unprecedented polymerization rates were achieved with extremely low light intensities (< 1 mW/cm<sup>2</sup>) and catalyst loadings (< 50 μM), exemplified by reaction completion within 60 seconds of irradiation using green, red, and NIR light-emitting diodes.

An ordered copper nanowell-array film with near-perfect broadband absorption from ultraviolet to near-infrared light

2020 ◽  
Vol 59 (11) ◽  
pp. 110906
Author(s):  
Juan Shen ◽  
Yong Ren ◽  
Xinxin Zhu ◽  
Min Mao ◽  
Quan Zhou ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Broadband Absorption

scholarly journals Recent Near-Infrared Light-Activated Nanomedicine toward Precision Cancer Therapy

2021 ◽  
Author(s):  
Xiaowei Luan ◽  
Yongchun Pan ◽  
Yanfeng Gao ◽  
Yujun Song
Keyword(s):  
Cancer Therapy ◽  
Near Infrared ◽  
Infrared Light ◽  
Human Society ◽  
Near Infrared Light ◽  
History Of ◽  
The Universe

Light has witnessed the history of mankind and even the universe. It is of great significances to the life of human society, contributing to energy, agriculture, communication, and much more....

scholarly journals Discovery of Infrared Stars in Globular Clusters in the Magellanic Clouds and Their Light Variations

1998 ◽  
Vol 11 (1) ◽  
pp. 395-395
Author(s):  
S. Nishida ◽  
T. Tanabé ◽  
S. Matsumoto ◽  
T. Onaka ◽  
Y. Nakada ◽  
...  
Keyword(s):  
Mass Loss ◽  
Globular Clusters ◽  
Main Sequence ◽  
Near Infrared ◽  
Magellanic Clouds ◽  
Infrared Light ◽  
Agb Stars ◽  
Dust Shells ◽  
Infrared Stars ◽  
Infrared Survey

A systematic near-infrared survey was made for globular clusters in the Magellanic Clouds. Two infrared stars were discovered in NGC419 (SMC) and NGC1783 (LMC). NGC419 and NGC1783 are well-studied rich globular clusters whose turn-off masses and ages are estimated MTO ~ 2.0 Mʘ and т ~1.2 Gyr for NGC419, and MT0 ~ 2.0 Mʘ and т ʘ 0.9 Gyr for NGC1783, respectively. The periods of the infrared light variations were determined to be 540 dfor NGC419IR1 and to be 480 d for NGC1783IR1, respectively. Comparison of the measurements with the period—if magnitude relation for carbon Miras in the LMC by Groenewegen and Whitelock(1996) revealed that the Kmagnitudes of the infrared stars were fainter by about 0.3 — 0.8 magnitude than those predicted by the P — K relation. This deviation can be explained if the infrared stars are surrounded by thick dust shells and are obscured even in the K band. The positions of NGC419IR1and NGC1783IR1 on the P — K diagram suggest that AGB stars with the main sequence masses of about 2 Mʘ start their heavy mass-loss when P ʘ 500 d.

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