scholarly journals Photothermal Polymer Nanocomposites of Tungsten Bronze Nanorods with Enhanced Tensile Elongation at Low Filler Contents

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1740 ◽  
Author(s):  
Byoungyun Jeon ◽  
Taehyung Kim ◽  
Dabin Lee ◽  
Tae Joo Shin ◽  
Kyung Wha Oh ◽  
...  
Keyword(s):  
Polymer Nanocomposites ◽  
Near Infrared ◽  
Tensile Elongation ◽  
Tungsten Bronze ◽  
Heat Emission ◽  
Cold Weather ◽  
Infrared Light ◽  
Droplet Transport ◽  
Wide Range ◽  
Weather Resistance

We present polymer nanocomposites of tungsten bronze nanorods (TBNRs) and ethylene propylene diene monomers (EPDM). The combination of these components allows the simultaneous enhancement in the mechanical and photothermal properties of the composites at low filler contents. The as-synthesized TBNRs had lengths and diameters of 14.0 ± 2.4 nm and 2.5 ± 0.5 nm, respectively, and were capped with oleylamine, which has a chemical structure similar to EPDM, making the TBNRs compatible with the bulk EPDM matrix. The TBNRs absorb a wide range of near-infrared light because of the sub-band transitions induced by alkali metal doping. Thus, the nanocomposites of TBNRs in EPDM showed enhanced photothermal properties owing to the light absorption and subsequent heat emission by the TBNRs. Noticeably, the nanocomposite with only 3 wt% TBNRs presented significantly enhanced tensile strain at break, in comparison with those of pristine EPDM, nanocomposites with 1 and 2 wt % TBNRs, and those with tungsten bronze nanoparticles, because of the alignment of the nanorods during tensile elongation. The photothermal and mechanical properties of these nanocomposites make them promising materials for various applications such as in fibers, foams, clothes with cold weather resistance, patches or mask-like films for efficient transdermal delivery upon heat generation, and photoresponsive surfaces for droplet transport by the thermocapillary effect in microfluidic devices and microengines.

scholarly journals In Situ Ultraviolet Polymerization Using Upconversion Nanoparticles: Nanocomposite Structures Patterned by Near Infrared Light

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2054
Author(s):  
Hongsub Jee ◽  
Guanying Chen ◽  
Paras N. Prasad ◽  
Tymish Y. Ohulchanskyy ◽  
Jaehyeong Lee
Keyword(s):  
Polymer Nanocomposites ◽  
Near Infrared ◽  
Infrared Light ◽  
Upconversion Nanoparticles ◽  
Nanocomposite Structure ◽  
Shell Design ◽  
Uv Visible ◽  
Harsh Conditions ◽  
Nanocomposite Structures

In this paper, we report an approach to polymerization of a nanocomposite containing UV-polymerizable organic material and inorganic, NaYbF4:Tm3+ core-based nanoparticles (NPs), which are optimized for upconversion of near infrared (NIR) to ultraviolet (UV) and blue light. Our approach is compatible with numerous existing UV-polymerizable compositions and the NaYF4: Yb, Tm3+ core-based NPs are much more stable against harsh conditions than NIR organic photo-initiators proposed earlier. The use of a core-shell design for the NPs can provide a suitable method for binding with organic constituents of the nanocomposite, while maintaining efficient NIR-to-UV/blue conversion in the NaYbF4 core. The prepared photopolymerized transparent polymer nanocomposites display upconversion photoluminescence in UV, visible and NIR ranges. We also demonstrate a successful fabrication of polymerized nanocomposite structure with millimeter/submillimeter size uniformly patterned by 980 nm irradiation of inexpensive laser diode through a photomask.

Absorption and Scatter Corrections for Transflectance Measurements in Nonhomogeneous Fiber Samples

1998 ◽  
Vol 6 (A) ◽  
pp. A35-A44 ◽  
Author(s):  
R.A. Taylor
Keyword(s):  
High Speed ◽  
Near Infrared ◽  
Light Transmission ◽  
Accurate Determination ◽  
Fiber Optic Sensor ◽  
Infrared Light ◽  
Specimen Preparation ◽  
Absorption Bands ◽  
Speed Sensor ◽  
Wide Range

A new fiber optic sensor was developed to measure the mass of optically thin cotton samples by integrating light transmission and reflectance signals. High speed measurements of cotton strength requires an accurate determination of the specimen mass without use of laborious cut-and-weigh methods. A previous high speed sensor measured changes in visible light transmission which required secondary measurements of fiber fineness to adjust the data for light scattering. Fiber orientation also affected scattering which required a precise control on specimen preparation. The new sensor measures fiber specimen transflectance using near infrared light. Because cellulose (the basic compound in cotton) exhibits strong absorption bands, its concentration can be accurately measured using near infrared absorbance. In this report we show that an integratinq sensor gave the best measurement of cotton fiber mass. Additionally, we demonstrated its accuracy over a wide range of fiber orientations using a novel fiber specimen tension experiment.

scholarly journals Age-related changes in diffuse optical tomography sensitivity profiles in infancy

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252036
Author(s):  
Xiaoxue Fu ◽  
John E. Richards
Keyword(s):  
Near Infrared ◽  
Optical Tomography ◽  
Diffuse Optical Tomography ◽  
Hemoglobin Concentration ◽  
Separation Distance ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Photon Propagation ◽  
Age Related ◽  
Wide Range

Diffuse optical tomography uses near-infrared light spectroscopy to measure changes in cerebral hemoglobin concentration. Anatomical interpretations of the location that generates the hemodynamic signal requires accurate descriptions of diffuse optical tomography sensitivity to the underlying cortical structures. Such information is limited for pediatric populations because they undergo rapid head and brain development. The present study used photon propagation simulation methods to examine diffuse optical tomography sensitivity profiles in realistic head models among infants ranging from 2 weeks to 24 months with narrow age bins, children (4 and 12 years) and adults (20 to 24 years). The sensitivity profiles changed systematically with the source-detector separation distance. The peak of the sensitivity function in the head was largest at the smallest separation distance and decreased as separation distance increased. The fluence value dissipated more quickly with sampling depth at the shorter source-detector separations than the longer separation distances. There were age-related differences in the shape and variance of sensitivity profiles across a wide range of source-detector separation distances. Our findings have important implications in the design of sensor placement and diffuse optical tomography image reconstruction in (functional) near-infrared light spectroscopy research. Age-appropriate realistic head models should be used to provide anatomical guidance for standalone near-infrared light spectroscopy data in infants.

scholarly journals Biomedical optical properties of color light and near-infrared fluorescence separated-merged imager

2019 ◽  
Vol 12 (06) ◽  
pp. 1940001
Author(s):  
Rui Zhang ◽  
Ya-Zhou Xue ◽  
Xiao-Feng Yang
Keyword(s):  
Optical Properties ◽  
Near Infrared ◽  
Perioperative Period ◽  
Infrared Light ◽  
Agarose Gel ◽  
Near Infrared Fluorescence ◽  
Imaging Characteristics ◽  
Reflected Light ◽  
Wide Range

Objective: We study the biomedical optical properties of the color light and near-infrared fluorescence separated-merged imager. Materials and Methods: The color light and near-infrared fluorescence separated-merged imager can illuminate the visible light and the near-infrared light of [Formula: see text][Formula: see text]nm, receiving the reflected light and [Formula: see text][Formula: see text]nm near-infrared fluorescence, and display the color, fluorescence and merge image. ICG solution of different concentration, including standing time, was allocated to study the best imaging condition in vitro, and the depth of fluorescence penetration was studied with 5% agarose gel; the imaging characteristics of the imager was studied using SD rat; and then the SLNs tracing in 4 cases of penile carcinoma was performed. Results: When the concentration of ICG is 13.11[Formula: see text][Formula: see text]mol/L, the fluorescence intensity and the merge image are the best. The maximum depth of fluorescence imaging is 9[Formula: see text]mm in 5% agarose gel, while the bone has the greatest influence on it. The SLNs tracing shows that the imager can locate the SLNs in vitro, to achieve perioperative navigation during biopsy. Conclusion: There are many factors that affect the imaging effect, but the imaging effect of the imager meets the requirement of vision in a wide range, and can effectively trace the SLNs in perioperative period.

scholarly journals Lipophilicity of Bacteriochlorin-Based Photosensitizers as a Determinant for PDT Optimization through the Modulation of the Inflammatory Mediators

2019 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Barbara Pucelik ◽  
Luis G. Arnaut ◽  
Janusz M. Dąbrowski
Keyword(s):  
Immune Response ◽  
Molecular Mechanisms ◽  
Near Infrared ◽  
Antitumor Immune Response ◽  
Infrared Light ◽  
Gm Csf ◽  
Hydrophobic Compound ◽  
Tnf Α ◽  
Wide Range

Photodynamic therapy (PDT) augments the host antitumor immune response, but the role of the PDT effect on the tumor microenvironment in dependence on the type of photosensitizer and/or therapeutic protocols has not been clearly elucidated. We employed three bacteriochlorins (F2BOH, F2BMet and Cl2BHep) of different polarity that absorb near-infrared light (NIR) and generated a large amount of reactive oxygen species (ROS) to compare the PDT efficacy after various drug-to-light intervals: 15 min. (V-PDT), 3h (E-PDT) and 72h (C-PDT). We also performed the analysis of the molecular mechanisms of PDT crucial for the generation of the long-lasting antitumor immune response. PDT-induced damage affected the integrity of the host tissue and developed acute (protocol-dependent) local inflammation, which in turn led to the infiltration of neutrophils and macrophages. In order to further confirm this hypothesis, a number of proteins in the plasma of PDT-treated mice were identified. Among a wide range of cytokines (IL-6, IL-10, IL-13, IL-15, TNF-α, GM-CSF), chemokines (KC, MCP-1, MIP1α, MIP1β, MIP2) and growth factors (VEGF) released after PDT, an important role was assigned to IL-6. PDT protocols optimized for studied bacteriochlorins led to a significant increase in the survival rate of BALB/c mice bearing CT26 tumors, but each photosensitizer (PS) was more or less potent, depending on the applied DLI (15 min, 3 h or 72 h). Hydrophilic (F2BOH) and amphiphilic (F2BMet) PSs were equally effective in V-PDT (>80 cure rate). F2BMet was the most efficient in E-PDT (DLI = 3h), leading to a cure of 65 % of the animals. Finally, the most powerful PS in the C-PDT (DLI = 72 h) regimen turned out to be the most hydrophobic compound (Cl2BHep), allowing 100 % of treated animals to be cured at a light dose of only 45 J/cm2.

Solvothermal Fabrication of Rubidium Tungsten Bronze for the Absorption of Near Infrared Light

2013 ◽  
Vol 13 (5) ◽  
pp. 3236-3239 ◽  
Author(s):  
Chongshen Guo ◽  
Shu Yin ◽  
Qiang Dong ◽  
Takeshi Kimura ◽  
Miyuki Tanaka ◽  
...  
Keyword(s):  
Near Infrared ◽  
Tungsten Bronze ◽  
Infrared Light ◽  
Near Infrared Light

The potential of transcranial photobiomodulation therapy for treatment of major depressive disorder

2017 ◽  
Vol 28 (4) ◽  
pp. 441-453 ◽  
Author(s):  
Farzad Salehpour ◽  
Seyed Hossein Rasta
Keyword(s):  
Major Depressive Disorder ◽  
Depressive Disorder ◽  
Near Infrared ◽  
Treatment Protocol ◽  
Photobiomodulation Therapy ◽  
Infrared Light ◽  
Major Depressive ◽  
Atp Production ◽  
Beneficial Effects ◽  
Wide Range

AbstractMajor depressive disorder is a common debilitating mood disorder that affects quality of life. Prefrontal cortex abnormalities, an imbalance in neurotransmitters, neuroinflammation, and mitochondrial dysfunction are the major factors in the etiology of major depressive disorder. Despite the efficacy of pharmacotherapy in the treatment of major depressive disorder, 30%–40% of patients do not respond to antidepressants. Given this, exploring the alternative therapies for treatment or prevention of major depressive disorder has aroused interest among scientists. Transcranial photobiomodulation therapy is the use of low-power lasers and light-emitting diodes in the far-red to near-infrared optical region for stimulation of neuronal activities. This non-invasive modality improves the metabolic capacity of neurons due to more oxygen consumption and ATP production. Beneficial effects of transcranial photobiomodulation therapy in the wide range of neurological and psychological disorders have been already shown. In this review, we focus on some issue relating to the application of photobiomodulation therapy for major depressive disorder. There is some evidence that transcranial photobiomodulation therapy using near-infrared light on 10-Hz pulsed mode appears to be a hopeful technique for treatment of major depressive disorder. However, further studies are necessary to find the safety of this method and to determine its effective treatment protocol.

scholarly journals Photobiomodulation and the brain – has the light dawned?

2016 ◽  
Vol 38 (6) ◽  
pp. 24-28 ◽  
Author(s):  
Michael R. Hamblin
Keyword(s):  
Traumatic Brain Injury ◽  
Clinical Trials ◽  
Brain Injury ◽  
Near Infrared ◽  
Infrared Light ◽  
Great Promise ◽  
Brain Cells ◽  
Brain Disorders ◽  
Wide Range ◽  
The Brain

Evidence is mounting that photobiomodulation therapy (shining near-infrared light) can benefit a wide range of brain disorders. The photons can penetrate into the brain where they stimulate production of energy in brain cells, and trigger numerous signaling pathways. Acute ischaemic stroke was the first indication that progressed to human clinical trials. Acute and chronic stages of traumatic brain injury were then investigated. Currently, psychiatric disorders such as depression, and neurodegenerative diseases such as Alzheimer's and Parkinson's are under investigation. Although showing great promise, more trials are clearly needed before the therapy will be accepted.

Photobiomodulation Therapy for Dementia: A Systematic Review of Pre-Clinical and Clinical Studies

2021 ◽  
pp. 1-22
Author(s):  
Farzad Salehpour ◽  
Mahsa Khademi ◽  
Michael R. Hamblin
Keyword(s):  
Systematic Review ◽  
Clinical Studies ◽  
Near Infrared ◽  
Irradiation Time ◽  
Ease Of Use ◽  
Infrared Light ◽  
Medical Disorders ◽  
Number Of Patients ◽  
Wide Range

Background: Photobiomodulation (PBM) involves the use of red and/or near-infrared light from lasers or LEDs to improve a wide range of medical disorders. Transcranial PBM, sometimes accompanied by intranasal PBM, has been tested to improve many brain disorders, including dementia. Objective: To conduct a systematic review according to PRISMA guidelines of pre-clinical and clinical studies reporting the use of PBM, which were considered relevant to dementia. Methods: Literature was searched between 1967 and 2020 using a range of keywords relevant to PBM and dementia. The light source and wavelength(s), output power, irradiance, irradiation time, fluence or total energy (dose), operation mode (continuous or pulsed) irradiation, approach and site, number of treatment sessions, as well as study outcome(s) were extracted. Results: Out of 10,473 initial articles, 36 studies met the inclusion criteria. Nine articles reported in vitro studies, 17 articles reported studies in animal models of dementia, and 10 studies were conducted in dementia patients. All of the included studies reported positive results. The clinical studies were limited by the small number of patients, lack of placebo controls in some instances, and only a few used objective neuroimaging methods. Conclusion: The preliminary evidence of clinical benefit, the lack of any adverse effects, and the remarkable ease of use, suggest larger clinical trials should be conducted as soon as possible.

The Value of Photo Biological Regulation Based on Nano Semiconductor Laser Technology in the Treatment of Hypertension Fundus Disease

2021 ◽  
Vol 21 (2) ◽  
pp. 1323-1330
Author(s):  
Xingui Hu ◽  
Linan Zhou ◽  
Huifeng Wang ◽  
Yuanpeng Gao ◽  
Yan Gao
Keyword(s):  
Semiconductor Laser ◽  
Near Infrared ◽  
Theoretical Data ◽  
Low Energy ◽  
Infrared Light ◽  
Tissue Blood Flow ◽  
Near Infrared Light ◽  
Biological Regulation ◽  
Laser Technology ◽  
Wide Range

With the development of nanometer semiconductor laser technology, due to the wide range of photobiological regulation and non-invasive advantages, it is widely used in clinical research, including reducing pain, accelerating wound healing, nerve injury repair and regeneration. Increase tissue blood flow, improve anxiety and depression, and treat Parkinson’s and retinal diseases. However, in many studies, the role of photobiological regulation is still controversial. There are two main problems, one is that the mechanism of photo biological regulation is not fully understood, and the other is that the specific parameters are not uniform in different treatments, such as wavelength density, power density, pulse, treatment timing, and number of treatments. In this paper, through the second question, the parameters of low-energy near-infrared light (810 nm semiconductor laser) in the treatment of fundus diseases are the main research objects. Based on understanding the parameters of low-energy lasers, cyan blue is irradiated with different energy near-infrared light. Data analysis of the actual energy obtained after the retina of the rabbit and observation and research on the cell morphology of each layer of the retina, to obtain relatively safe treatment parameters for the retina, provide theoretical data for near-infrared light in the treatment of clinical fundus disease, and make it safer to use in clinical treatment.

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