نتایج جستجو برای: photon emission

تعداد نتایج: 231968  

Journal: :Journal of biomedical optics 2011
Anshu Rastogi Pavel Pospísil

All living organisms emit spontaneous ultraweak photon emission as a result of cellular metabolic processes. In this study, the involvement of reactive oxygen species (ROS) formed as the byproduct of oxidative metabolic processes in spontaneous ultraweak photon emission was studied in human hand skin. The effect of molecular oxygen and ROS scavengers on spontaneous ultraweak photon emission fro...

Introduction: This paper analyses the ability of single-photon avalanche diodes (SPADs) for neural imaging. The current trend in the production of SPADs moves toward the minimumdark count rate (DCR) and maximum photon detection probability (PDP). Moreover, the jitter response which is the main measurement characteristic for the timing uncertainty is progressing. Methods: The neural imaging pro...

Journal: :archives of cardiovascular imaging 0
arash gholoobi preventive cardiovascular care research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, mashhad, ir iran; preventive cardiovascular care research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, p. o. box: 9137913316, mashhad, ir iran. tel/fax: +98-5138544504

discussion the reason is that we assess the relative and not absolute differences of the tracer uptake in this imaging modality. there may be other findings on mpi images which could help us overcome this pitfall, including detecting wall motion abnormalities, lung uptake of the tracer, or transient ischemic dilation. another important issue is the ecg changes during exercise stress testing, wh...

2007
Michal CIFRA Eduard VAN WIJK Heike KOCH Saskia BOSMAN Roeland VAN WIJK

Ultra-weak photon emission in the visible range was measured on palm and dorsal side of left and right hand by means of a low noise photomultiplier system. To study the dynamics of this photon emission in a 24 h period photon emission was recorded in 2 h intervals in 5 experiments, utilizing strict protocols for dark adaptation and recording of subjects. Fluctuations in photon emission in the c...

Journal: :Neuroscience research 1999
M Kobayashi M Takeda T Sato Y Yamazaki K Kaneko K Ito H Kato H Inaba

Living cells spontaneously emit ultraweak light during the process of metabolic reactions associated with the physiological state. The first demonstration of two-dimensional in vivo imaging of ultraweak photon emission from a rat's brain, using a highly sensitive photon counting apparatus, is reported in this paper. It was found that the emission intensity correlates with the electroencephalogr...

Journal: :Physical review letters 2012
Eden Rephaeli Shanhui Fan

We study stimulated emission from an excited two-level atom coupled to a waveguide containing an incident single-photon pulse. We show that the strong photon correlation, as induced by the atom, plays a very important role in stimulated emission. Additionally, the temporal duration of the incident photon pulse is shown to have a marked effect on stimulated emission and atomic lifetime.

2007
Alex Hayat Pavel Ginzburg Meir Orenstein

We propose a compact high-intensity room-temperature source of entangled photons based on the efficient second-order process of two-photon spontaneous emission from electrically pumped semiconductor quantum wells in a photonic microcavity. Two-photon emission rate in room-temperature semiconductor devices is determined solely by the carrier density, regardless of the residual one-photon emissio...

This mage based series comprises of a quiz pertaining to the identification of salient anatomical structures expected to be seen at a given level on the computed tomography (CT) followed by examples of multiple representative pathologies that can be seen at the same level in a routine clinical setting. It is expected that this will improve confidence of nuclear physicians in interpretation of t...

  Solitary pulmonary nodule (SPN) is a frequent finding on the chest x-ray and computed tomography. Nuclear medicine techniques play an important role in the diagnosis and management of SPN. In the current review, we briefly will explain the different nuclear medicine modalities in this regard including positron emission tomography (PET) using 18-F-FDG, and 11-C-Methionine, and single photon em...

Journal: :Nuclear Physics A 2017

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