Photon Emission Research Articles

Asymptomatic multifocal avascular necrosis, a commonly overlooked finding in patients with systemic lupus erythematosus

BackgroundIn patients with Systemic lupus erythematosus (SLE), osteonecrosis of various joints is a debilitating complication associated with the disease and its treatment, in which a considerable proportion of osteonecrosis may be asymptomatic. Recognizing the crucial role of early and timely detection, as well as appropriate management of asymptomatic osteonecrosis, in preventing joint destruction, we conducted a study to evaluate the prevalence of asymptomatic osteonecrosis in SLE patients who have already been diagnosed with symptomatic osteonecrosis. Additionally, we aimed to examine the relationship between proposed risk factors of osteonecrosis and the development of asymptomatic osteonecrosis.MethodsIn this cross-sectional study, Patients with recently diagnosed symptomatic osteonecrosis of at least one joint were selected by reviewing data from the digital medical record system of the Rheumatology Research Center. The patients underwent three-phase Single Photon Emission Computed Tomography (SPECT) bone scintigraphy to screen for other asymptomatic osteonecrotic joints. MRI was subsequently performed on the asymptomatic osteonecrotic sites for further diagnostic confirmation. The study evaluated the prevalence of asymptomatic osteonecrosis, the extent of joint involvement, the specific locations of osteonecrosis, the most commonly affected joints, and the risk factors for asymptomatic osteonecrosis.ResultsEight out of the 17 patients (47%) who participated in our research were found to have asymptomatic osteonecrosis. The most commonly affected joint without symptoms was the left knee (25%), while the most frequently affected joint with symptoms was the left hip (23.07%). The only statistically significant difference observed between patients with and without asymptomatic osteonecrosis in this study was the age at which the disease first appeared (p = 0.046) and this age was higher among patients with asymptomatic osteonecrosis.ConclusionsOur research provides further evidence of the high incidence of asymptomatic osteonecrosis in individuals with SLE due to the nature of the disease and the frequent use of high-dose corticosteroids. It underscores the importance of early detection through whole-body SPECT bone scintigraphy and MRI, as well as prompt intervention in order to avert the incapacitating effects of osteonecrosis.

AI‐powered automated analysis of bone scans: A survey

AbstractAs one of the key techniques of artificial intelligence, deep learning has emerged as an effective approach for analysing medical images. Various imaging techniques including the planar bone scintigraphy, single photon emission computed tomography and PET can be used to evaluate, in vivo, bone conditions. The introduction of deep learning techniques especially the convolutional neural networks can significantly improve diagnosis accuracy and efficiency of nuclear medicine physicians. Focusing on bone scans acquired by various nuclear medicine imaging techniques, his paper reviews existing work on deep learning‐based classification, segmentation and object detection of bone scans. Specifically, an overview of existing work about research objective is presented, deep learning models are adopted, and main results are achieved. Research challenges and directions for developing automated analysis of bone scans with deep learning techniques are then discussed.

Spontaneous photon emission by shaped quantum electron wavepackets and the QED origin of bunched electron beam superradiance

It has been shown that the spontaneous emission rate of photons by free electrons, unlike stimulated emission, is independent of the shape or modulation of the quantum electron wavefunction (QEW). Nevertheless, here we show that the quantum state of the emitted photons is non-classical and does depend on the QEW shape. This non-classicality originates from the shape dependent off-diagonal terms of the photon density matrix. This is manifested in the Wigner distribution function and would be observable experimentally through homodyne detection techniques as a squeezing effect. Considering a scheme of electrons interaction with a single microcavity mode, we present a QED formulation of spontaneous emission by multiple modulated QEWs through a build-up process. Our findings indicate that in the case of a density modulated QEWs beam, the phase of the off-diagonal terms of the photon state emitted by the modulated QEWs is the harbinger of bunched beam superradiance, where the spontaneous emission is proportional toNe2. This observation offers a potential for enhancement of other quantum electron interactions with quantum systems by a modulated QEWs beam carrying coherence and quantum properties of the modulation.

Quantum Wire Coupled to Light

Experimental advances in cavity QED are raising the prospect of using light to probe quantum materials beyond the linear response regime. The capability to access quantum coherent phenomena would significantly advance the field. However, theoretical work on many-body systems coupled to light in the quantum coherent regime has been select. Here, we investigate the radiative properties of a finite-sized quantum wire in a microwave cavity. Examples of quantum wires include single-walled carbon nanotubes, a key experimental system in the field of nano-optics and plasmonics. We find that, for a variety of excited states, the repeated emission of photons results in the generation of many-body quantum entanglement. This leads to an increase in the rate at which subsequent photons are emitted, an example of Dicke superradiance. On the other hand, Pauli blocking tends to reduce this effect. Bosonization, the description of the excitations of a one-dimensional electron system as a gas of bosons, is found to be a powerful theoretical tool in this context. Its application means that many of our results generalize to wires with strong electron-electron interactions. The quantum wire thus represents a new platform to realize Dicke-model physics that does not rely on the various fine tunings necessary in traditional realizations involving many spatially isolated emitters. More broadly, this work demonstrates how quantum entanglement can be generated and measured in a many-body system. Published by the American Physical Society 2024

Circularly polarized photon emission from magnetized chiral plasmas

Circularly polarized photon emission from magnetized chiral plasmas

Comparison of 2D and 3D lung lobe quantification with Ventilation/Perfusion Ratio.

In this study, standard 2D lung lobe quantification is compared with two 3D lung lobe quantification software tools to investigate the clinical benefit of a 3D approach. The accuracy of 2D versus 3D lung lobe quantification is evaluated based on the calculated numerical ventilation-perfusion ratio (VQR) using a receiver operating curve (ROC) analysis.A study group of 50 consecutive patients underwent a planar lung scintigraphy (anterior/posterior) as well as ventilation/perfusion single photon emission computed tomography (SPECT/CT) to exclude acute pulmonary embolism. All data were acquired with SPECT OPTIMA NM/CT 640 (GE Healthcare). 2D analysis was performed for all ventilation/perfusion scans using a lung analysis tool (Syngo Workstation, Siemens Healthineers). 3D quantification analysis was performed using QLUNG (Q. Lung, Xeleris 4.0, GE Healthcare) and LLQ (Hermes Hybrid 3D Lung Lobar Quantification, Hermes Medical Solutions). The area under the ROC curve (AUC) served as a decision criterion to find the best agreement between clinical PE findings and calculated PE candidates of the 2D and 3D methods. The significance of the ROC curves was evaluated using the DeLong comparison.A significant difference between 2D/3D could be determined. Both 3D approaches showed robust and comparable results. The AUC range of [0.10, 0.67] was given for 2D lobar analysis, QLUNG AUC range revealed in [0.39,0.74] and LLQ AUC range was [0.42,0.72]. Averaged over all lung lobes an AUC=0.39 was given for 2D analysis and AUC=0.58 was given for LLQ/QLUNG.We could demonstrate the better performance of 3D analysis compared to 2D analysis. Consequently, is recommended to use a 3D approach in clinical practice.

Dark matter-electron scattering search using cryogenic light detectors

The cryogenic scintillating calorimeter technology devoted to rare event searches is reaching the sensitivity level required for the hunt of dark matter-electron scatterings. Dark matter-electron interactions in scintillating targets are expected to stimulate the emission of single photons, each of energy equal to the target electronic band gap. The electronic band gap in scintillators like NaI/GaAs is of O(eV). The search for this signal can be done by an array of cryogenic light detectors with eV/sub−eV energy resolution. In this work, we describe the detection principle, the detector response, and the envisioned detector design to search for dark matter interacting with electrons via the measurement of the scintillation light at millikelvin. First sensitivity projections are provided, which show the potential of this research. Published by the American Physical Society 2024

Ansatz about a Zero Momentum Mode in QCD and the Forward Slope in pp Elastic Scattering

We recall a resummation procedure in QED to extract the zero momentum mode in soft photon emission and present an ansatz about a possible mechanism for the forward peak characterizing elastic proton proton scattering.

Investigating photon emissions from homeopathic potencies

Studies using solvatochromic dyes appear to show that potencies have a polarising and structuring effect in solution. Taking these results further it can be predicted that on dissolution of solution structures, both heat and light should be emitted. It has been shown that a weak electric current passed through solutions of Antimonium crudum destroys the potency, as judged by its effect on the solvatochromic dye ET33. To see if potencies emit light on application of an electric current concomitant with this destruction of activity, a specially adapted ultra-sensitive luminometer has been employed which allows currents of pre-determined voltage to be passed through both control solutions and potency solutions in situ. Preliminary results indicate that photons are emitted from potency solutions beyond those of control solutions. What is particularly interesting is that photon emission does not occur immediately on application of an electric current but a significant delay occurs before emissions are seen. In addition, emissions appear to show evidence of oscillations over time before finally dying out. Results will be discussed in relation to previous studies on the physical chemistry of potencies and what these results might be telling us about the fundamental nature of potencies.

Dual–resonance enhancement and polarization control of upconversion luminescence of NaYF4:Yb,Er nanoparticles on 2D metal gratings

In this work, we report enhancement and polarization control of multi–color (green/red) upconversion luminescence (UCL) of lanthanide–doped (NaYF4:Yb,Er) nanoparticles by dual–resonance modes of surface plasmons (SP) on two–dimensional (2D) metal gratings in orthogonal directions. Investigations are performed for the SP resonance modes to be tuned, by adjusting the grating periods, to match any one or two of the green–UCL, red–UCL and excitation wavelengths. It is shown that, for the upconversion nanoparticles (UCNPs) on the 2D gratings with both of the dual resonance modes matching the green–/red–UCL or excitation wavelength, enhancements of the UCLs are roughly doubled, compared with their one–dimensional (1D) counterparts. And when the dual resonance modes match the green– or red–UCL and the excitation wavelength, enhancements of the UCLs are further greatly improved, in spite that the resonance modes for the excitation and emission light are in orthogonal directions. As the emitted UCL photons are largely coupled with the dual SP resonance modes, the radiated green– and red–UCL light can be distinguished by their linear polarization states in orthogonal directions. It is also indicated that polarization of the excitation light can influence the polarization of the UCL light when coupled with the SP resonance modes.

Abnormal magnetic field topology in the beam-plasma instability driven by ion dynamics

We report on abnormal topological structures in the particles and electromagnetic field distributions induced by current filamentation instability, with emphasis on the effects of plasma ions. In the plasma filament (PF) situation, the transverse magnetic field reaches its maximum at the edge of the plasma filaments, in contrast to the case of beam filament (BF, i.e., the magnetic field reaches the maximum at the edge of the beam filaments). An analytical model is proposed to estimate the response time of the beam electrons and plasma ions, which is essential to determine the criterion of PF occurrence. With increase in beam energy and density, and decrease in plasma ion mass, the transition from BF to PF can be observed. The results are also confirmed by detailed electromagnetic particle-in-cell simulations. Moreover, the influence of PF on the synchrotron photon emission power is also discussed.

Exercise electrocardiogram combined with CZT cardiac-dedicated SPECT predicts coronary artery disease

BackgroundCoronary artery disease (CAD) is a primary cause of mortality, prompting ongoing research into noninvasive diagnostic modalities. This study aimed to evaluate the diagnostic efficacy of exercise electrocardiography testing (EET) combined with cadmium zinc tellurium cardiac-dedicated single photon emission computed tomography (CZT-SPECT) imaging for CAD. MethodsCZT-SPECT and EET were examined in 124 patients aged 20–85 years, followed by coronary angiography to evaluate the sensitivity, specificity, positive predictive value, and negative predictive value of EET/CZT-SPECT alone and in combination. CAD was defined as the presence of > 50% stenosis at the time of coronary angiography. ResultsThe sensitivity of the EET test alone was 31.58%, the specificity was 80%, the positive predictive value (PPV) was 22.22%, and the negative predictive value (NPV) was 86.6%. The corresponding values of CZT-SPECT alone were 36.07%, 92.06%, 81.48% and 59.79%, respectively. The combined results showed that the sensitivity, specificity, PPV, and NPV were 60.00%, 90.57%, 54.55%, and 92.31%, respectively. In this study, the positive likelihood ratio (PLR) diagnosed with EET alone was 1.58, the PLR diagnosed with CZT-SPECT alone was 4.54, and the PLR diagnosed with combination was 6.36. ConclusionsThe combination of CZT-SPECT and EET showed significantly improved CAD diagnostic accuracy compared with either approach alone.

Temporal Pound–Rebka experiment as gravitational Aharonov–Bohm effect

One of the classical tests of general relativity is the precision measurements by Pound and Rebka of red-shift/blue-shift of photons in a gravitational field. In this essay, we lay out a temporal version of the Pound–Rebka experiment. The emission and absorption of photons occurs at different times, rather than at different spatial locations as in the original Pound–Rebka experiment. This temporal Pound–Rebka experiment is equivalent to a gravitational Aharonov–Bohm Effect and is testable via current or near future satellite experiments.

On the randomness of time ordered quantum measurements

A new method for efficient, high-quality randomness extraction is presented. The method relies on quantum processes such as the emission of single photons and their subsequent detection, where each detection event has an associated detection time. By establishing a list of time differences between a fixed number of events, a unique order can be established.We note that, by utilising the number of ways to order the resulting list of time differences between the quantum events, the efficiency can be increased many-fold compared to current methods. The method delivers fundamentally uniform randomness and therefore, in principle, does not need debiasing.

Resonant structure for improved directionality and extraction of single photons

Abstract Fluorescent atomic defects, particularly in dielectric materials such as diamond, are promising for several emerging quantum applications. However, efficient light extraction, directional emission, and narrow spectral emission are key challenges. We have designed a dielectric metasurface exploiting Mie-resonance and Kerker conditions to address these issues. Our designed diamond metasurface, tailored for nitrogen-vacancy (NV) defect centers in diamond, predicts up to 500x improvement in the collection of 637 nm (zero phonon line) photons over that from the bare diamond. Our design achieves highly directional emission, predominantly emitting in a 20° lobe in the forward direction. This makes the light collection more efficient, including fiber-based collection. The predicted results are stable against the position of the emitter placed in the metaelement, thus alleviating the challenging fabrication requirement of precise positioning of the defect center. Equally importantly, our design approach can be applied to enhance single photon emission also from other defects such as SiV, other materials such as hBN, and other sources such as quantum dots.

Ultra-weak photon emission from DNA

It is conventionally believed that macromolecules found in living cells, including DNA, RNA, and proteins, do not exhibit inherent light emission. However, recent studies have challenged this concept by demonstrating spontaneous light emission from nucleic acids under certain conditions and physiological temperatures. By noninvasive monitoring of barley genomic DNA and advanced statistical physics analyses, temperature-induced dynamic entropy fluctuations and fractal dimension oscillations were identified at a key organizational threshold. The study revealed evidence for non-equilibrium phase transitions, a noticeable photovoltaic current jump at zero bias voltage, and a proportional increase (scaling) of the photoinduced current corresponding to increasing amounts of DNA. In addition, we estimated DNA’s energy production rate at criticality and introduced an interferometer using coherent light emissions from the DNA-water interface. These findings suggest that DNA is a major source of ultraweak photon emission in biological systems.

Quantum Pair Generation in Nonlinear Metasurfaces with Mixed and Pure Photon Polarizations.

Metasurfaces are highly effective at manipulating classical light in the linear regime; however, effectively controlling the polarization of nonclassical light generated from nonlinear resonant metasurfaces remains a challenge. Here, we present a solution by achieving polarization engineering of frequency-nondegenerate biphotons emitted via spontaneous parametric down-conversion in GaAs metasurfaces, utilizing quasi-bound states in the continuum (qBIC) resonances to enhance biphoton generation. Through comprehensive polarization tomography, we demonstrate that the emitted photons' polarization directly reflects the qBIC mode's far-field properties. Furthermore, we show that both the type of qBIC mode and the symmetry of the meta-atoms can be tailored to control each single-photon polarization state, and that the subsequent two-photon polarization states are nearly separable, offering potential applications in the heralded generation of single photons with adjustable polarization. This work provides a significant step toward utilizing metasurfaces to generate quantum light and engineer their polarization, a critical aspect for future quantum technologies.

The eagle-wing finding in FP-CIT SPECT, as a characteristic finding in patients with DESH- type iNPH.

Although dopamine transporter (DAT) imaging has been reported to be useful for differentiating idiopathic Normal Pressure Hydrocephalus (iNPH) from its mimics, the radiological findings of DAT imaging in iNPH have not been established. We investigated [123I] N-ω-fluoropropyl-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane (FP-CIT) single photon emission computed tomography (SPECT) images from patients with disproportionately enlarged subarachnoid-space hydrocephalus (DESH)-type iNPH to understand the characteristics of DAT images of iNPH. We retrospectively collected 11 DESH-type iNPH patients without comorbidities who underwent FP-CIT SPECT imaging. The patients' FP-CIT SPECT were examined using both visual and quantitative evaluations. Visual assessment used Kahraman et al.'s five-step grading, and quantitative assessment used DaTView and MIM software to calculate specific binding ratios (SBRs) for four volumes of interest (VOIs): the entire striatum, caudate nucleus, anterior putamen, and posterior putamen. Intergroup comparisons were made between the DESH group and a normal control (NC) group adjusted for age and sex. The visual assessment classified 91% of DESH patients as showing grade 4 'eagle-wing' on FP-CIT SPECT, with a Kappa coefficient of 0.601. The median SBR was lower in the DESH group than in the NC group for all four VOIs, and significantly lower in the anterior and posterior putamen (p < 0.05). In DESH-type iNPH, FP-CIT SPECT imaging typically shows the 'eagle-wing' finding due to decreased DAT concentration in the putamen. Our results enhance the utility of FP-CIT SPECT in diagnosing iNPH and distinguishing it from mimics.

TIME REFRACTION and SPACETIME OPTICS

A review of recent advances in spacetime optics is given, with special emphasis on time refraction. This is a basic optical process, occurring at a temporal discontinuity or temporal boundary, which is able to produce various different effects, such as frequency shifts, energy amplification, time reflection, and photon emission. If, instead of a single discontinuity, we have two reverse temporal boundaries, we can form a temporal beam splitter, where temporal interferences can occur. It will also be shown that, in the presence of an axis of symmetry, such as a magnetic field, the temporal beam splitter can induce a rotation of the initial polarization state, similar to a Faraday rotation. Recent work on time crystals, superluminal fronts, and superfluid light will be reviewed. Time gates based on spacetime optical effects will be discussed. We also mention recent work on optical metamaterials. Finally, the quantum properties of time refraction, which imply the emission of photon from vacuum, are considered, while similar problems in high-energy QED associated with electron–positron pairs are briefly mentioned.

Development of a novel radioiodinated compound for amyloid and tau deposition imaging in Alzheimer's disease and tauopathy mouse models

Non-invasive determination of amyloid-β peptide (Aβ) and tau deposition are important for early diagnosis and therapeutic intervention for Alzheimer's disease (AD) and non-AD tauopathies. In the present study, we investigated the capacity of a novel radioiodinated compound AD-DRK (123/125I-AD-DRK) with 50% inhibitory concentrations of 11 nM and 2 nM for Aβ and tau aggregates, respectively, as a single photon emission computed tomography (SPECT) ligand in living brains. In vitro and ex vivo autoradiography with 125I-AD-DRK was performed in postmortem human and two transgenic (Tg) mice lines with either fibrillar Aβ or tau accumulation, APP23 and rTg4510 mice. SPECT imaging of 123I-AD-DRK was performed in APP23 mice to investigate the ability of AD-DRK to visualize fibrillar protein deposition in the living brain. In-vitro autoradiogram of 125I-AD-DRK showed high specific radioactivity accumulation in the temporal cortex and hippocampus of AD patients and the motor cortex of progressive supranuclear palsy (PSP) patients enriched by Aβ and/or tau aggregates. Ex-vivo autoradiographic images also demonstrated a significant increase in 125I-AD-DRK binding in the forebrain of both APP23 and rTg450 mice compared to their corresponding non-Tg littermates. SPECT imaging successfully captured Aβ deposition in the living brain of aged APP23 mice. The present study developed a novel high-contrast SPECT agent for assisting the diagnosis of AD and non-AD tauopathies, likely benefiting from its affinity for both fibrillar Aβ and tau.