Experimental studies of charmonia in two-photon collisions at Belle

2006 ◽  
Vol 162 ◽  
pp. 299-304 ◽  
Author(s):  
S. Uehara
Keyword(s):  
Experimental Studies ◽  
Two Photon

scholarly journals Photoselection of Luminescent Molecules in Anisotropic Media in the Case of Two-Photon Excitation. Part II. Experimental Studies of Hoechst 33342 in Stretched Polyvinyl alcohol) Films

1996 ◽  
Vol 51 (9) ◽  
pp. 1037-1041 ◽  
Author(s):  
A. Kawski ◽  
Z. Gryczyński ◽  
I. Gryczyński ◽  
J. R. Lakowicz ◽  
G. Piszczek
Keyword(s):  
Polyvinyl Alcohol ◽  
Vinyl Alcohol ◽  
Experimental Studies ◽  
Poly Vinyl Alcohol ◽  
Hoechst 33342 ◽  
Emission Anisotropy ◽  
Two Photon ◽  
Photon Excitation ◽  
Polyvinyl Alcohol Films ◽  
Two Photon Excitation

Abstract It was found by investigating dichroism and emission anisotropy in the case of one-and two-photon excitation of Hoechst 33342 [bis-benzimide,2,5'-bi-1H-benzimidazole, 2'-(4-ethoxyphenyl)-5-5(4-methyl-1-piperazinyl)] in stretched poly(vinyl alcohol) (PVA) films, that the absorption and fluorescence transition moments lie along the long molecular axis of the molecule studied. The slight deviation of the transition moment direction in fluorescence (about 8°) from that in absorption can be due to the incomplete linearity of the Hoechst molecule.

scholarly journals Prolonged anesthesia alters brain synaptic architecture

2019 ◽  
Author(s):  
Michael Wenzel ◽  
Alexander Leunig ◽  
Shuting Han ◽  
Darcy S. Peterka ◽  
Rafael Yuste
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Function ◽  
Side Effects ◽  
Synapse Formation ◽  
Experimental Studies ◽  
Synaptic Loss ◽  
Two Photon ◽  
Brain Mechanism ◽  
Cortical Synapses ◽  
Behavioral Object

SUMMARYProlonged medically-induced coma (pMIC), a procedure performed in millions of patients worldwide, leads to cognitive impairment, yet the underlying brain mechanism remains unknown. No experimental studies of medically-induced coma (MIC) exceeding ~6 hours exist. For MIC of less than 6 hours, studies in developing rodents have documented transient changes of cortical synapse formation. However, in adulthood, cortical synapses are thought to become stabilized. Here, we establish pMIC (up to 24 hrs) in adolescent and mature mice, and combine repeated behavioral object recognition assessments with longitudinal two-photon imaging of cortical synapses. We find that pMIC affects cognitive function, and is associated with enhanced synaptic turnover, generated by enhanced synapse formation during pMIC, while the post-anesthetic period is dominated by synaptic loss. These results carry profound implications for intensive medical care, as they point out at significant structural side effects of pMIC on cortical brain synaptic architecture across age levels.

scholarly journals Two-Photon Interferences of Weak Coherent Lights

2021 ◽  
Author(s):  
Heonoh Kim ◽  
Osung Kwon ◽  
Han Seb Moon
Keyword(s):  
Quantum Communication ◽  
Information Science ◽  
Single Photon ◽  
Experimental Studies ◽  
Light Sources ◽  
Long Distance ◽  
Coincidence Counting ◽  
Two Photon ◽  
Potential Applications ◽  
Photon States

Abstract Multiphoton interference is an important phenomenon in modern quantum mechanics and experimental quantum optics, and it is fundamental for the development of quantum information science and technologies. Over the last three decades, several theoretical and experimental studies have been performed to understand the essential principles underlying such interference and to explore potential applications. Recently, the two-photon interference (TPI) of phase-randomized weak coherent states has played a key role in the realization of long-distance quantum communication based on the use of classical light sources. In this context, we investigated TPI experiments with weak coherent pulses and quantitatively analyzed the results in terms of the single- and coincidence-counting rates and one- and two-photon interference-fringe shapes. We experimentally examined the Hong-Ou-Mandel-type TPI of phase-randomized weak coherent pulses to compare the TPI effect at the single-photon level with that of correlated photons. Further experiments were also performed with two temporally- and spatially separated weak coherent pulses. Although the observed interference results, including the results of visibility and fringe shape, can be suitably explained by classical intensity correlation, the physics underlying the TPI effect needs to be interpreted as the interference between the two-photon states at the single-photon level within the utilized interferometer. The results of this study can provide a more comprehensive understanding of the TPI of coherent light at the single-photon level.

scholarly journals E/Z Molecular Photoswitches Activated by Two-Photon Absorption: Comparison between Different Families

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7379
Author(s):  
Marco Marazzi ◽  
Cristina García-Iriepa ◽  
Carlos Benitez-Martin ◽  
Francisco Najera ◽  
Antonio Monari ◽  
...  
Keyword(s):  
Excited States ◽  
Cross Sections ◽  
Experimental Studies ◽  
Substitution Effect ◽  
Photon Absorption ◽  
Spatial Control ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Absorption Energy ◽  
Donor Acceptor

Nonlinear optical techniques as two-photon absorption (TPA) have raised relevant interest within the last years due to the capability to excite chromophores with photons of wavelength equal to only half of the corresponding one-photon absorption energy. At the same time, its probability being proportional to the square of the light source intensity, it allows a better spatial control of the light-induced phenomenon. Although a consistent number of experimental studies focus on increasing the TPA cross section, very few of them are devoted to the study of photochemical phenomena induced by TPA. Here, we show a design strategy to find suitable E/Z photoswitches that can be activated by TPA. A theoretical approach is followed to predict the TPA cross sections related to different excited states of various photoswitches’ families, finally concluding that protonated Schiff-bases (retinal)-like photoswitches outperform compared to the others. The donor-acceptor substitution effect is therefore rationalized for the successful TPA activatable photoswitch, in order to maximize its properties, finally also forecasting a possible application in optogenetics. Some experimental measurements are also carried out to support our conclusions.

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