Synthesis of organic phenothiazine-based molecular glasses and effect of racemic/homochiral aliphatic chain on near-infrared photorefractive property

2012 ◽  
Vol 73 (9) ◽  
pp. 1136-1145 ◽  
Author(s):  
Yingliang Liu ◽  
Ryushi Fujimura ◽  
Kazuki Ishida ◽  
Nobuhiro Oya ◽  
Naoko Yoshie ◽  
...  
Keyword(s):  
Near Infrared ◽  
Aliphatic Chain ◽  
Molecular Glasses ◽  
Photorefractive Property

Quantum mechanically calculated NIR spectra of fatty acids

NIR news ◽  
2017 ◽  
Vol 28 (8) ◽  
pp. 11-16 ◽  
Author(s):  
Justyna Grabska
Keyword(s):  
Fatty Acids ◽  
Near Infrared ◽  
Unsaturated Fatty Acids ◽  
Theoretical Study ◽  
Calculated Data ◽  
Nir Spectroscopy ◽  
Theoretical Modelling ◽  
Aliphatic Chain ◽  
Computing Power ◽  
Technical Article

The advances in theory as well as steady development of the computing power have made quantum mechanical simulation of NIR spectra feasible. Recently, we have demonstrated the ability to accurately reproduce in theory the NIR spectra of several complex biomolecules, including fatty acids. In the present technical article, some of these achievements are overviewed. Examples of theoretical modelling of NIR spectra of short- (aliphatic chain up to four carbon atoms) and medium-chain (aliphatic chain counting six carbon atoms) fatty acids are presented and discussed. The calculated data are used directly for explaining the experimental NIR spectra of these systems. Spectral features distinctive to saturated vs. unsaturated fatty acids are essential in various types of samples typically treated by NIR spectroscopy; i.e. food, tissue, biomaterial, etc. Therefore, the theoretical study offers considerable support for basic and applied NIRS. An example of possible practical application of the results of theoretical study for biochemical studies is provided. The topic discussed here has been presented during the 18th International Conference on Near Infrared Spectroscopy (ICNIRS-2017) in Copenhagen, June 2017.

Construction of a near-infrared responsive upconversion nanoplatform against hypoxic tumors via NO-enhanced photodynamic therapy

Nanoscale ◽  
2020 ◽  
Vol 12 (14) ◽  
pp. 7875-7887 ◽  
Author(s):  
Ying Lan ◽  
Xiaohui Zhu ◽  
Ming Tang ◽  
Yihan Wu ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Near Infrared ◽  
Upconversion Nanoparticles

A near-infrared (NIR) activated theranostic nanoplatform based on upconversion nanoparticles (UCNPs) is developed in order to overcome the hypoxia-associated resistance in photodynamic therapy by photo-release of NO upon NIR illumination.

A nitroreductase-activatable near-infrared theranostic photosensitizer for photodynamic therapy under mild hypoxia

2020 ◽  
Vol 56 (43) ◽  
pp. 5819-5822
Author(s):  
Jing Zheng ◽  
Yongzhuo Liu ◽  
Fengling Song ◽  
Long Jiao ◽  
Yingnan Wu ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Triplet State ◽  
Near Infrared ◽  
Mild Hypoxia

In this study, a near-infrared (NIR) theranostic photosensitizer was developed based on a heptamethine aminocyanine dye with a long-lived triplet state.

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.

A New Method for the Synthesis of Heptamethine Cyanine Dyes:  Synthesis of New Near Infrared Fluorescent Labels

1997 ◽  
Vol 62 (26) ◽  
pp. 9387-9387 ◽  
Author(s):  
Narasimhachari Narayanan ◽  
Lucjan Strekowski ◽  
Malgorzata Lipowska ◽  
Gabor Patonay
Keyword(s):  
Near Infrared ◽  
Cyanine Dyes ◽  
New Method ◽  
Fluorescent Labels

Psychophysiological Responses to Stress Related to Anxiety in Healthy Aging

2019 ◽  
Vol 33 (3) ◽  
pp. 188-197 ◽  
Author(s):  
Roberta Adorni ◽  
Agostino Brugnera ◽  
Alessia Gatti ◽  
Giorgio A. Tasca ◽  
Kaoru Sakatani ◽  
...  
Keyword(s):  
Healthy Aging ◽  
Near Infrared ◽  
Response Times ◽  
Cognitive Resources ◽  
Stressful Condition ◽  
Healthy Elderly ◽  
Situational Stress ◽  
Anxiety Response ◽  
Nirs Signal ◽  
Psychophysiological Correlates

Abstract. The aim of the study was to explore the effects of situational stress and anxiety in a group of healthy elderly, both in terms of psychophysiological correlates and cognitive performance. Eighteen participants ( Mage = 70 ± 6.3; range 60–85) were assessed for anxiety and were instructed to perform a computerized math task, under both a stressful and a control condition, while near-infrared spectroscopy (NIRS) signal and electrocardiography (ECG) were recorded. NIRS results evidenced an increased activation of right PFC during the entire procedure, even if effect sizes between left and right channels were larger during the experimental condition. The amount of right activation during the stressful condition was positively correlated with anxiety. Response times (RTs) were slower in more anxious than in less anxious individuals, both during the control and stressful conditions. Accuracy was lower in more anxious than in less anxious individuals, only during the stressful condition. Moreover, heart rate (HR) was not modulated by situational stress, nor by anxiety. Overall, the present study suggests that in healthy elderly, anxiety level has a significant impact on cerebral responses, and both on the amount of cognitive resources and the quality of performance in stressful situations.

Sign in / Sign up

Export Citation Format

Share Document