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https://www.readbyqxmd.com/read/28803949/measuring-temporal-summation-in-visual-detection-with-a-single-photon-source
#1
Rebecca Holmes, Michelle Victora, Ranxiao Frances Wang, Paul G Kwiat
Temporal summation is an important feature of the visual system which combines visual signals that arrive at different times. Previous research estimated complete summation to last for 100 ms for stimuli judged "just detectable." We measured the full range of temporal summation for much weaker stimuli using a new paradigm and a novel light source, developed in the field of quantum optics for generating small numbers of photons with precise timing characteristics and reduced variance in photon number. Dark-adapted participants judged whether a light was presented to the left or right of their fixation in each trial...
August 10, 2017: Vision Research
https://www.readbyqxmd.com/read/28803178/treatment-of-unstable-thoracolumbar-fractures-does-fracture-level-fixation-accelerate-the-bone-healing
#2
Zühtü Özbek, Emre Özkara, Hasan Önner, Gültekin Baş, İpek Canan Erman, Hülya Özen, Emre Entok, Ali Arslantaş
OBJECTIVE: This study aimed to investigate the effect of fusion on short segment including fractured level (SSIFL) and long segment (LS) transpedicular fixation after acute thoracolumbar junction (TLJ) burst fractures. The two-year clinical and radiological follow-up results of the two groups were also compared. METHODS: Seventy-four patients were randomized into one of two groups: SSIFL (n: 39) or LS (n: 35). The SSIFL group included one level above and one level below, including the fracture level, while the LS group included two levels above and two levels below, excluding the fracture level, for the transpedicular fixation...
August 9, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28802921/imaging-the-nonmotor-symptoms-in-parkinson-s-disease
#3
Tayyabah Yousaf, Heather Wilson, Marios Politis
Parkinson's disease is acknowledged to be a multisystem syndrome, manifesting as a result of multineuropeptide dysfunction, including dopaminergic, cholinergic, serotonergic, and noradrenergic deficits. This multisystem disorder ultimately leads to the presentation of a range of nonmotor symptoms, now appreciated to be an integral part of the disease-specific spectrum of symptoms, often preceding the diagnosis of motor Parkinson's disease. In this chapter, we review the dopaminergic and nondopaminergic basis of these symptoms by exploring the neuroimaging evidence based on several techniques including positron emission tomography, single-photon emission computed tomography molecular imaging, magnetic resonance imaging, functional magnetic resonance imaging, and diffusion tensor imaging...
2017: International Review of Neurobiology
https://www.readbyqxmd.com/read/28799355/observation-of-propane-cluster-size-distributions-during-nucleation-and-growth-in-a-laval-expansion
#4
Jorge J Ferreiro, Satrajit Chakrabarty, Bernhard Schläppi, Ruth Signorell
We report on molecular-level studies of the condensation of propane gas and propane/ethane gas mixtures in the uniform (constant pressure and temperature) postnozzle flow of Laval expansions using soft single-photon ionization by vacuum ultraviolet light and mass spectrometric detection. The whole process, from the nucleation to the growth to molecular aggregates of sizes of several nanometers (∼5 nm), can be monitored at the molecular level with high time-resolution (∼3 μs) for a broad range of pressures and temperatures...
December 7, 2016: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28798203/peripheral-ventilation-heterogeneity-determines-the-extent-of-bronchoconstriction-in-asthma
#5
Catherine E Farrow, Cheryl M Salome, Benjamin E Harris, Dale L Bailey, Norbert Berend, Gregory G King
In asthma, bronchoconstriction causes topographically heterogeneous airway narrowing, as measured by 3-dimensional ventilation imaging. Computation modelling suggests that peripheral airway dysfunction is a potential determinant of acute airway narrowing measured by imaging. We hypothesised that the development of low ventilation regions measured topographically by 3-dimensional imaging after bronchoconstriction is predicted by peripheral airway function. Fourteen (14) asthmatic subjects underwent ventilation Single Photon Emission Computed Tomography/CT (VSPECT/CT) before and after methacholine challenge...
August 10, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28796522/on-chip-waveguide-coupling-of-a-layered-semiconductor-single-photon-source
#6
Philipp Tonndorf, Osvaldo Del Pozo Zamudio, Nico Gruhler, Johannes Kern, Robert Schmidt, Alexander I Dmitriev, Anatoly P Bakhtinov, Alexander I Tartakovskii, Wolfram Hp Pernice, Steffen Michaelis de Vasconcellos, Rudolf Bratschitsch
Fully integrated quantum technology based on photons is in the focus of current research, because of its immense potential concerning performance and scalability. Ideally, the single-photon sources, the processing units, and the photon detectors are all combined on a single chip. Impressive progress has been made for on-chip quantum circuits and on-chip single-photon detection. In contrast, non-classical light is commonly coupled onto the photonic chip from the outside, because presently only few integrated single-photon sources exist...
August 10, 2017: Nano Letters
https://www.readbyqxmd.com/read/28794138/quantitative-assessment-of-coronary-microvascular-function-dynamic-single-photon-emission-computed-tomography-positron-emission-tomography-ultrasound-computed-tomography-and-magnetic-resonance-imaging
#7
Attila Feher, Albert J Sinusas
A healthy, functional microcirculation in combination with nonobstructed epicardial coronary arteries is the prerequisite of normal myocardial perfusion. Quantitative assessment in myocardial perfusion and determination of absolute myocardial blood flow can be achieved noninvasively using dynamic imaging with multiple imaging modalities. Extensive evidence supports the clinical value of noninvasively assessing indices of coronary flow for diagnosing coronary microvascular dysfunction; in certain diseases, the degree of coronary microvascular impairment carries important prognostic relevance...
August 2017: Circulation. Cardiovascular Imaging
https://www.readbyqxmd.com/read/28792136/impact-of-follow-up-ischemia-on-myocardial-perfusion-single-photon-emission-computed-tomography-in-patients-with-coronary-artery-disease
#8
Se Hun Kang, Hyo In Choi, Young Hak Kim, Eun Young Lee, Jung Min Ahn, Seungbong Han, Pil Hyung Lee, Jae Hyung Roh, Sung Han Yun, Duk Woo Park, Soo Jin Kang, Seung Whan Lee, Cheol Whan Lee, Dae Hyuk Moon, Seong Wook Park, Seung Jung Park
PURPOSE: Few studies have reported on predicting prognosis using myocardial perfusion single-photon emission computed tomography (SPECT) during coronary artery disease (CAD) treatment. Therefore, we aimed to assess the clinical implications of myocardial perfusion SPECT during follow-up for CAD treatment. MATERIALS AND METHODS: We enrolled 1153 patients who had abnormal results at index SPECT and underwent follow-up SPECT at intervals ≥6 months. Major adverse cardiac events (MACE) were compared in overall and 346 patient pairs after propensity-score (PS) matching...
September 2017: Yonsei Medical Journal
https://www.readbyqxmd.com/read/28782410/non-invasive-methods-for-measuring-vascular-changes-in-neurovascular-headaches
#9
Henrik W Schytz, Faisal M Amin, Juliette Selb, David A Boas
Vascular changes during spontaneous headache attacks have been studied over the last 30 years. The interest in cerebral vessels in headache research was initially due to the hypothesis of cerebral vessels as the pain source. Here, we review the knowledge gained by measuring the cerebral vasculature during spontaneous primary headache attacks with the use of single photon emission tomography (SPECT), positron emission tomography (PET), magnetic resonance imaging (MRA) and transcranial Doppler (TCD). Furthermore, the use of near-infrared spectroscopy in headache research is reviewed...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28782032/a-photonic-platform-for-donor-spin-qubits-in-silicon
#10
Kevin J Morse, Rohan J S Abraham, Adam DeAbreu, Camille Bowness, Timothy S Richards, Helge Riemann, Nikolay V Abrosimov, Peter Becker, Hans-Joachim Pohl, Michael L W Thewalt, Stephanie Simmons
Donor spins in silicon are highly competitive qubits for upcoming quantum technologies, offering complementary metal-oxide semiconductor compatibility, coherence (T2) times of minutes to hours, and simultaneous initialization, manipulation, and readout fidelities near ~99.9%. This allows for many quantum error correction protocols, which will be essential for scale-up. However, a proven method of reliably coupling spatially separated donor qubits has yet to be identified. We present a scalable silicon-based platform using the unique optical properties of "deep" chalcogen donors...
July 2017: Science Advances
https://www.readbyqxmd.com/read/28781201/seven-tesla-mri-of-the-substantia-nigra-in-patients-with-rapid-eye-movement-sleep-behavior-disorder
#11
Daniela Frosini, Mirco Cosottini, Graziella Donatelli, Mauro Costagli, Laura Biagi, Claudio Pacchetti, Michele Terzaghi, Pietro Cortelli, Dario Arnaldi, Enrica Bonanni, Michela Tosetti, Ubaldo Bonuccelli, Roberto Ceravolo
INTRODUCTION: Susceptibility-weighted imaging of the substantia nigra (SN) both at 7 and 3 Tesla (T) has shown high accuracy in distinguishing patients with Parkinson's disease (PD) and healthy subjects (HS). Patients with rapid eye movement (REM) behavior disorder (RBD) can develop synucleinopathies, and such risk is higher with dopamine transporter single photon emission tomography (123I-FP-CIT SPECT) evidence of nigro-striatal dysfunction. We aimed at evaluating SN 7T magnetic resonance imaging (7T-MRI) in patients with RBD and determining the agreement between MRI and 123I-FP-CIT SPECT...
August 2, 2017: Parkinsonism & related Disorders
https://www.readbyqxmd.com/read/28780044/from-interventionist-imaging-to-intraoperative-guidance-new-perspectives-by-combining-advanced-tools-and-navigation-with-radio-guided-surgery
#12
S Vidal-Sicart, R Valdés Olmos, O E Nieweg, R Faccini, M R Grootendorst, H J Wester, N Navab, B Vojnovic, H van der Poel, S Martínez-Román, J Klode, F Wawroschek, F W B van Leeuwen
The integration of medical imaging technologies into diagnostic and therapeutic approaches can provide a preoperative insight into both anatomical (e.g. using computed tomography (CT), magnetic resonance (MR) imaging, or ultrasound (US)), as well as functional aspects (e.g. using single photon emission computed tomography (SPECT), positron emission tomography (PET), lymphoscintigraphy, or optical imaging). Moreover, some imaging modalities are also used in an interventional setting (e.g. CT, US, gamma or optical imaging) where they provide the surgeon with real-time information during the procedure...
August 3, 2017: Revista Española de Medicina Nuclear e Imagen Molecular
https://www.readbyqxmd.com/read/28777753/gender-based-cerebral-perfusion-differences-in-46-034-functional-neuroimaging-scans
#13
Daniel G Amen, Manuel Trujillo, David Keator, Derek V Taylor, Kristen Willeumier, Somayeh Meysami, Cyrus A Raji
BACKGROUND: Studies have reported that females have widespread increases in regional cerebral blood flow, but the studies were relatively small and inconsistent. OBJECTIVE: Here we analyzed a healthy and very large psychiatric population to determine the effect of gender, using single photon emission computed tomography (SPECT). METHODS: Whole brain and region of interest (ROI) gender differences were analyzed in a total of 46,034 SPECT scans at baseline and concentration...
August 4, 2017: Journal of Alzheimer's Disease: JAD
https://www.readbyqxmd.com/read/28777590/many-particle-entanglement-criterion-for-superradiantlike-states
#14
Mehmet Emre Tasgin
We derive a many-particle entanglement criterion for mixed states using a relation between single-mode and many-particle nonclassicalities. The criterion relies on the measurement of collective spin observables. It works very well not only in the vicinity of the Dicke states, but also for the superpositions of Dicke states: superradiant ground states of finite or infinite number of particles and time evolution of single-photon superradiance from an extended sample where random phases appear. We also obtain a criterion for ensemble-field entanglement, which is successful for such kinds of states...
July 21, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28775287/non-invasive-in-vivo-determination-of-viable-islet-graft-volume-by-111-in-exendin-3
#15
Wael A Eter, Inge Van der Kroon, Karolina Andralojc, Mijke Buitinga, Stefanie M A Willekens, Cathelijne Frielink, Desiree Bos, Lieke Joosten, Otto C Boerman, Maarten Brom, Martin Gotthardt
Pancreatic islet transplantation is a promising therapy for patients with type 1 diabetes. However, the duration of long-term graft survival is limited due to inflammatory as well as non-inflammatory processes and routine clinical tests are not suitable to monitor islet survival. (111)In-exendin-SPECT (single photon emission computed tomography) is a promising method to non-invasively image islets after transplantation and has the potential to help improve the clinical outcome. Whether (111)In-exendin-SPECT allows detecting small differences in beta-cell mass (BCM) and measuring the actual volume of islets that were successfully engrafted has yet to be demonstrated...
August 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28775200/prognostic-value-of-123-i-betamethyl-p-iodophenyl-pentadecanoic-acid-single-photon-emission-computed-tomography-in-patients-with-non-ischemic-heart-failure-with-preserved-ejection-fraction
#16
Hidenobu Hashimoto, Rine Nakanishi, Sunao Mizumura, Yukiko Hashimoto, Yuriko Okamura, Shunsuke Kiuchi, Junichi Yamazaki, Takanori Ikeda
Myocardial fatty acid metabolism imaging using (123)I-betamethyl-p-iodophenyl-pentadecanoic acid single-photon emission computed tomography (BMIPP-SPECT) is a useful modality for identifying high-risk patients with known ischemic heart disease. However, its utility for patients with non-ischemic heart failure with preserved ejection fraction (NIHFpEF) is not well-known. This study aims to evaluate the prognostic value of BMIPP defect score (BDS) in patients presenting with NIHFpEF. Methods: Of 804 consecutive patients who were admitted to the hospital because of acute HF and underwent BMIPP-SPECT, we identified 133 patients (73±13 years) who had normal coronary artery by invasive coronary angiography and preserved left ventricular ejection fraction (≥50%) by echocardiography...
August 3, 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
https://www.readbyqxmd.com/read/28775077/chronic-rejection-of-cardiac-allografts-is-associated-with-increased-lymphatic-flow-and-cellular-trafficking
#17
Lindsey A Edwards, Anna K Nowocin, Nazila V Jafari, Lucy Meader, Kathryn Brown, Aurélien Sarde, Carolyn Lam, Alex Murray, Wilson Wong
Background -Cardiac transplantation is an excellent treatment for end-stage heart disease. However, rejection of the donor graft, particularly by chronic rejection leading to cardiac allograft vasculopathy, remains a major cause of graft loss. The lymphatic system plays a crucial role in the alloimmune response, facilitating trafficking of antigen presenting cells (APCs) to draining lymph nodes (dLN). The encounter of APCs with T lymphocytes in secondary lymphoid organs is essential for the initiation of alloimmunity...
August 3, 2017: Circulation
https://www.readbyqxmd.com/read/28774469/thalamic-neurometabolic-alterations-in-tremulous-parkinson-s-disease-a-preliminary-proton-mr-spectroscopy-study
#18
Gaetano Barbagallo, Gennarina Arabia, Maurizio Morelli, Rita Nisticò, Fabiana Novellino, Maria Salsone, Federico Rocca, Andrea Quattrone, Manuela Caracciolo, Umberto Sabatini, Andrea Cherubini, Aldo Quattrone
INTRODUCTION: The objective of this study was to investigate the thalamic biochemical changes in tremor-dominant Parkinson's disease (tPD) patients in comparison with essential tremor with resting tremor (rET) patients, by using proton MR spectroscopy ((1)H-MRS). METHODS: Fourteen tPD patients, 12 rET patients and 10 controls participated in this study. All patients underwent dopamine transporter single-photon emission computed tomography (DAT-SPECT) with (123)I-ioflupane, and a short-echo single-voxel (1)H-MRS on a 3T scanner...
July 28, 2017: Parkinsonism & related Disorders
https://www.readbyqxmd.com/read/28770673/physiological-characteristics-of-photoreceptors-in-the-lamprey-lethenteron-japonicum
#19
Keisuke Sakurai
Lampreys are among the most basal vertebrates, and similar to jawed vertebrates, they have two types of photoreceptors: long photoreceptors (LP; putative cones) and short photoreceptors (SP; putative rods). It is intriguing to examine the physiological properties of vision in these animals. Although there is an accumulating body of histological and biochemical studies of photoreceptors of the lamprey Lethenteron japonicum, many physiological characteristics of this species have not been described. In the present study, single-cell recordings of photoreceptors in the upstream migrant lamprey were performed to investigate the physiological properties of SP and LP of the lamprey Lethenteron japonicum...
August 2017: Zoological Science
https://www.readbyqxmd.com/read/28770549/therapy-related-longitudinal-brain-perfusion-changes-in-patients-with-chronic-pelvic-pain-syndrome
#20
Christian Weisstanner, Livio Mordasini, George N Thalmann, Rajeev K Verma, Christian Rummel, Andrea Federspiel, Thomas M Kessler, Roland Wiest
BACKGROUND: The imaging method most frequently employed to identify brain areas involved in neuronal processing of nociception and brain pain perception is blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI). Arterial spin labelling (ASL), in contrast, offers advantages when slow varying changes in brain function are investigated. Chronic pelvic pain syndrome (CPPS) is a disorder of, mostly, young males that leads to altered pain perceptions in structures related to the pelvis...
August 3, 2017: Swiss Medical Weekly
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