X-ray Analysis of Structural Changes in Photochromic Salicylideneaniline Crystals. Solid-State Reaction Induced by Two-Photon Excitation

1999 ◽  
Vol 121 (24) ◽  
pp. 5809-5810 ◽  
Author(s):  
Jun Harada ◽  
Hidehiro Uekusa ◽  
Yuji Ohashi
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Structural Changes ◽  
X Ray ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation

Dynamic erectile responses of a novel penile organ model utilizing two photon excitation microscopy (TPEM)†

2021 ◽  
Author(s):  
Daiki Hashimoto ◽  
Tsuyoshi Hirashima ◽  
Hisao Yamamura ◽  
Tomoya Kataoka ◽  
Kota Fujimoto ◽  
...  
Keyword(s):  
Structural Changes ◽  
Corpus Cavernosum ◽  
Oxidative Stress Marker ◽  
Relaxation Processes ◽  
No Donor ◽  
Two Photon ◽  
Photon Excitation ◽  
Sinusoidal Space ◽  
Two Photon Excitation

Abstract Male penis is required to become erect during copulation. In the upper (dorsal) part of penis, the erectile tissue termed corpus cavernosum (CC) plays fundamental roles for erection by regulating the inner blood flow. When blood flows into the CC, the microvascular complex termed sinusoidal space is reported to expand during erection. A novel in vitro explant system to analyze the dynamic erectile responses during contraction/relaxation is established. The current data show regulatory contraction/relaxation processes induced by phenylephrine (PE) and nitric oxide (NO) donor mimicking dynamic erectile responses by in vitro CC explants. Two photon excitation microscopy (TPEM) observation shows the synchronous movement of sinusoidal space and the entire CC. By taking advantages of the CC explant system, tadalafil (cialis) was shown to increase sinusoidal relaxation. Histopathological changes have been generally reported associating with erection in several pathological conditions. Various stressed statuses have been suggested to occur in the erectile responses by previous studies. The current CC explant model enables to analyze such conditions through directly manipulating CC in the repeated contraction/relaxation processes. Expression of oxidative stress marker and contraction related genes, Hif1a, Gpx1, RhoA, Rock was significantly increased in such repeated contraction/relaxation. Altogether, it is suggested that the system is valuable for analyzing structural changes and physiological responses to several regulators in the field of penile medicine.

Solid state red biphotonic excited emission from small dipolar fluorophores

2016 ◽  
Vol 4 (4) ◽  
pp. 766-779 ◽  
Author(s):  
Martin Ipuy ◽  
Yuan-Yuan Liao ◽  
Erwann Jeanneau ◽  
Patrice L. Baldeck ◽  
Yann Bretonnière ◽  
...  
Keyword(s):  
Solid State ◽  
Penetration Depth ◽  
Near Infrared ◽  
Emission Wavelength ◽  
Infrared Range ◽  
Two Photon ◽  
Photon Excitation ◽  
Near Infrared Range ◽  
Two Photon Excitation

Dyes emitting in the solid state in the red or near-infrared range are much sought after for application in bioimaging especially if the long emission wavelength can be combined with two-photon excitation to provide unique contrast and penetration depth.

Two-photon excitation microscopy in cellular biophysics

1995 ◽  
Vol 53 ◽  
pp. 62-63
Author(s):  
David W. Piston ◽  
Brian D. Bennett ◽  
Robert G. Summers
Keyword(s):  
Confocal Microscopy ◽  
Laser Beam ◽  
Duty Cycle ◽  
Excited Electronic State ◽  
Input Power ◽  
Two Photon ◽  
Simultaneous Absorption ◽  
Photon Excitation ◽  
Very High ◽  
Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10-5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

Two-photon excitation fluorescence microscopy in living systems

1993 ◽  
Vol 51 ◽  
pp. 154-155 ◽  
Author(s):  
David W. Piston
Keyword(s):  
Confocal Microscopy ◽  
Fluorescence Microscopy ◽  
Singlet State ◽  
Excited Electronic State ◽  
Input Power ◽  
Two Photon ◽  
Simultaneous Absorption ◽  
Photon Excitation ◽  
Very High ◽  
Two Photon Excitation

Two-photon excitation fluorescence microscopy provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In our fluorescence experiments, the final excited state is the same singlet state that is populated during a conventional fluorescence experiment. Thus, the fluorophore exhibits the same emission properties (e.g. wavelength shifts, environmental sensitivity) used in typical biological microscopy studies. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10−5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

Two‐photon excitation fluorescence microscopy using a semiconductor laser

Bioimaging ◽  
1995 ◽  
Vol 3 (2) ◽  
pp. 70-75 ◽  
Author(s):  
Pekka E Hänninen ◽  
Martin Schrader ◽  
Erkki Soini ◽  
Stefan W Hell
Keyword(s):  
Fluorescence Microscopy ◽  
Semiconductor Laser ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation
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