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1
Berkovits, R., and M. Kaveh. "Weak localisation of photons in a disordered two-dimensional medium." Journal of Physics C: Solid State Physics 20, no. 11 (April 20, 1987): L181—L185. http://dx.doi.org/10.1088/0022-3719/20/11/001.
2
Makshantsev, B. I., and V. B. Makshantsev. "Scattering of an ensemble of photons taking their space — time localisation into account." Quantum Electronics 31, no. 9 (September 30, 2001): 760–65. http://dx.doi.org/10.1070/qe2001v031n09abeh002040.
3
Burdyko, A., M. Caccia, A. Giaz, R. Santoro, and G. Tomaciello. "Design and commissioning of a Silicon Photomultiplier-based dosimeter for Low Dose Rate (LDR) oncological brachytherapy." Journal of Instrumentation 19, no. 03 (March 1, 2024): C03025. http://dx.doi.org/10.1088/1748-0221/19/03/c03025.
Анотація:
Abstract Brachytherapy is a radiotherapy procedure performed with radioactive sources implanted into the patient's body, close to the area affected by cancer. This is a reference procedure for the treatment of prostate and gynecologic cancer due to the reduction of the dose released close to organs at risk (e.g., rectum, bladder, colon). For this reason, real-time dose verification and source localisation are essential for an optimal treatment plan. The ORIGIN collaboration aims to achieve this goal through a 16-fibre sensor system, designed to house a small volume of scintillating material in a transparent fibre tip to enable point-like measurements. The selected scintillating materials feature a decay time of about 500 μs and the signal associated with the primary γ-ray interaction results in the emission of a sequence of single photons distributed over time. Therefore, the dosimeter requires a detector with single-photon sensitivity and a system designed to provide dose measurements by photon counting. Uniformity of fibre response, system stability and reproducibility of measurements are key features of the dosimeter. The characterisation of the 16-channel dosimeter system equipped with thermo-electrically cooled Silicon Photomultipliers, carried out in the laboratory using an X-ray cabinet, is discussed and the results are compared with an earlier version equipped with SiPMs operated at room temperature.
4
Jumpee, Chayanit, Chanakarn Onnomdee, Putthiporn Charoenphun, Phiphat Phruksarojanakun, and Krisanat Chuamsaamarkkee. "Radiation safety aspects of 90Y bremsstrahlung radiation produced from radiation shielding apparatus using the Monte Carlo simulation." Nuclear Technology and Radiation Protection 36, no. 3 (2021): 255–60. http://dx.doi.org/10.2298/ntrp2103255j.
Анотація:
Selective internal radiation therapy using an 90Y labelled microsphere is increasingly used to treat hepatocellular carcinoma. Based on its properties, 90Y can produce bremsstrahlung radiation which is essential for post-treatment localisation and dosimetry. However, bremsstrahlung radiation could lead to an increase of radiation exposure of radiation workers. The aim of this work was to determine the 90Y bremsstrahlung radiation produced from the polymethyl methacrylate radiation shielding apparatus using the Monte Carlo simulation. A scintillation detector with a 137Cs standard source was used to validate the Monte Carlo simulation. After validation, the 90Y bremsstrahlung photons spectrum produced from the radiation shielding apparatus was simulated. The radiation equivalent dose rates to the head, neck, body, lower extremities at a distance of 30 centimeters, and finger (contact with the knob) were estimated to be 4.9 ? 0.6, 6.2 ? 0.1, 18.9 ? 0.4, 13.1 ? 0.6, and 3900 ? 50 ?Svh?1, respectively. The corresponding annual doses exceeded the limit when radiation workers performed 2631, 1563, 769, and 515 cases per year with contact the knob 3, 5, 10, and 15 minutes per case, respectively. The simulation result showed that radiation exposure of radiation workers and the number of selective internal radiation therapy procedures performed should be considered.
5
Illand, Abigail, Pierre Jouchet, Emmanuel Fort, and Sandrine Lévêque-Fort. "Localisation nanométrique de molécules uniques par modulation du signal de fluorescence." Photoniques, no. 114 (2022): 30–35. http://dx.doi.org/10.1051/photon/202111430.
Анотація:
La microscopie de localisation de molécules individuelles permet de dépasser la limite de diffraction, révélant ainsi l’organisation cellulaire à l’échelle nanométrique. Cette méthode reposant sur l’analyse spatiale du signal émis par les molécules, reste souvent limitée à l’observation d’objets biologiques à de faibles profondeurs, ou très peu aberrants. Nous montrons ici que l’introduction d’un paramètre temporel dans le processus de localisation via l’introduction d’une excitation modulée permet d’adresser ces limitations.
6
Skipetrov, Sergey. "Localisation d’Anderson de la lumière." Photoniques, no. 108 (May 2021): 24–27. http://dx.doi.org/10.1051/photon/202110824.
Анотація:
Un tas de poussière capable de capturer la lumière plus efficacement qu’une cavité Fabry-Perot finement réglée ? Un laser qui n’a pas besoin de réglage et dont la structure est aléatoire ? Tout cela peut devenir possible grâce au phénomène découvert par Philip Anderson il y a plus de 60 ans. Les idées apparues en physique du solide sont aujourd’hui exploitées par les opticiens qui essayent de tirer profit de la nature aléatoire de nombreux matériaux.
7
Grojo, David. "L’émergence de procédés d’écriture laser 3D dans les technologies silicium." Photoniques, no. 112 (2022): 37–42. http://dx.doi.org/10.1051/photon/202211237.
Анотація:
Les lasers femtosecondes sont à la base des technologies d’écriture 3D permettant l'intégration de nombreuses fonctionnalités micro-optiques, fluidiques et mécaniques à l'intérieur des matériaux diélectriques transparents. Cependant, des défis importants restent à relever pour transposer ces technologies dans le silicium et les semiconducteurs avec les nouvelles sources infrarouges intenses. La forte non-linéarité de propagation inhérente aux semi-conducteurs limite intrinsèquement la localisation de l'énergie lumineuse à un niveau en dessous des régimes d’écriture dans les configurations conventionnelles. L’émergence récente de solutions à ce problème ouvre de nouveaux champs d’applications notamment dans la photonique sur silicium.
8
Pike, E. R., and S. Sarkar. "Photon localisation in parametric down-conversion." Quantum Optics: Journal of the European Optical Society Part B 1, no. 1 (September 1989): 61–73. http://dx.doi.org/10.1088/0954-8998/1/1/007.
9
See, Tian Feng. "Few-photon transport in strongly interacting light-matter systems: A scattering approach." International Journal of Quantum Information 17, no. 06 (September 2019): 1950050. http://dx.doi.org/10.1142/s0219749919500503.
Анотація:
Engineering strong photon–photon interactions at the quantum level have been crucial in various areas of research, notably in quantum information processing and quantum simulation. It is often done by coupling matter strongly to light. A promising way to achieve this is via waveguide quantum electrodynamics (QED). Motivated by these advancements, we study few-photon transport in waveguide QED setups. First, we present a diagrammatic technique to systematically study multiphoton scattering based on the scattering formalism and Green’s function approach. We demonstrate our proposal through physically relevant examples involving scattering of few-photon states from two-level emitters as well as from arrays of correlated Kerr nonlinear resonators described by the Bose–Hubbard model. In the second part, we apply the diagrammatic technique that was developed to perform a comprehensive study on a Bose–Hubbard lattice with a quasi-periodic potential. This model exhibits many-body localisation. We compute the two-photon transmission probability and show that it carries signatures of the underlying localisation transition with close agreement to the participation ratio of the eigenstates. The systematic scattering approach provided in this paper provides a foundation for future works at the interface between quantum optics and condensed matter.
10
Maćkiewicz, Jarosław J., and Olsza Borys. "First record of invasive slug Krynickillus melanocephalus Kaleniczenko, 1851 (Gastropoda: Eupulmonata: Agriolimacidae) in Poland." Folia Malacologica 31, no. 4 (December 11, 2023): 229–35. http://dx.doi.org/10.12657/folmal.031.024.
Анотація:
During amateur nature observations in Kabaty Woods Nature Reserve in Warsaw, a slug of family Agriolimacidae was sighted. Photos with localisation tags have been submitted to iNaturalist website, where the algorithm suggested an identification of Krynickillus melanocephalus Kaleniczenko, 1851. Following specialists’ interests, three specimens were collected from the original location. Anatomical examination confirmed their identification. It is therefore the first documented record of K. melanocephalus in Poland.
11
Pati, Arun Kumar. "Photon localisation, the Pryce operator and the Aharonov-Bohm effect." Physics Letters A 218, no. 1-2 (July 1996): 5–10. http://dx.doi.org/10.1016/0375-9601(96)00349-0.
12
White, Samuel R., Kieran T. Wood, Peter G. Martin, Dean T. Connor, Thomas B. Scott, and David A. Megson-Smith. "Radioactive Source Localisation via Projective Linear Reconstruction." Sensors 21, no. 3 (January 26, 2021): 807. http://dx.doi.org/10.3390/s21030807.
Анотація:
Radiation mapping, through the detection of ionising gamma-ray emissions, is an important technique used across the nuclear industry to characterise environments over a range of length scales. In complex scenarios, the precise localisation and activity of radiological sources becomes difficult to determine due to the inability to directly image gamma photon emissions. This is a result of the potentially unknown number of sources combined with uncertainties associated with the source-detector separation—causing an apparent ‘blurring’ of the as-detected radiation field relative to the true distribution. Accurate delimitation of distinct sources is important for decommissioning, waste processing, and homeland security. Therefore, methods for estimating the precise, ‘true’ solution from radiation mapping measurements are required. Herein is presented a computational method of enhanced radiological source localisation from scanning survey measurements conducted with a robotic arm. The procedure uses an experimentally derived Detector Response Function (DRF) to perform a randomised-Kaczmarz deconvolution from robotically acquired radiation field measurements. The performance of the process is assessed on radiation maps obtained from a series of emulated waste processing scenarios. The results demonstrate a Projective Linear Reconstruction (PLR) algorithm can successfully locate a series of point sources to within 2 cm of the true locations, corresponding to resolution enhancements of between 5× and 10×.
13
ISHIDA, Akito. "Localisation of Photon Energy on Nano-Structured Gold Surface and the Photochemical Application." Review of Laser Engineering 29, no. 11 (2001): 739–43. http://dx.doi.org/10.2184/lsj.29.739.
14
Pelletier, Isabelle, Hannelore C. Sauerwein, Franco Lepore, Dave Saint‐Amour, and Maryse Lassonde. "Non‐invasive alternatives to the Wada test in the presurgical evaluation of language and memory functions in epilepsy patients." Epileptic Disorders 9, no. 2 (June 2007): 111–26. http://dx.doi.org/10.1684/epd.2007.0109.
Анотація:
ABSTRACT The cognitive outcome of the surgical removal of an epileptic focus depends on the assessment of the localisation and functional capacity of language and memory areas which need to be spared by the neurosurgeon. Traditionally, presurgical evaluation of epileptic patients has been achieved by means of the intracarotid amobarbital test assisted by neuropsychological measures. However, the advent of neuroimaging techniques has provided new ways of assessing these functions by means of non‐invasive or minimally invasive methods, such as anatomical and functional magnetic resonance imaging, positron emission tomography, single‐photon emission computed tomography, transcranial magnetic stimulation, functional transcranial Doppler monitoring, magnetoencephalography and near infrared spectroscopy. This paper aims at comparing and evaluating the traditional and recent preoperative approaches from a neuropsychological perspective.
15
Petlušová, Viera, Peter Petluš, Erika Tobiašová, and Juraj Hreško. "Using the Methodological Procedures for Water Erosion Risk Areas Identification for Sustainable Land Use." Ekológia (Bratislava) 39, no. 2 (June 1, 2020): 145–58. http://dx.doi.org/10.2478/eko-2020-0011.
Анотація:
AbstractThe countries of the European Union have joined, inter alia, soil protection in the Common Agricultural Policy (hereinafter referred to as CAP). Accelerated soil erosion is a problem resulting from inappropriate land management, which affects both the presence of organic matter and the soil structure. The tool for elimination of negative impacts on soil can be its sustainable use. This requires the use of an accurate system to improve its condition. The first step should be problem identification and localisation. The research is aimed at the identification of water erosion risk areas by using selected methodological procedures. The research area was located at the intensively used hilly land of the Southwestern Slovakia. The digitisation of the manual interpretation of erosion risk areas with the use of aerial photos, erosion modelling, chemical analysis of soil organic matter (SOM) and analysis of soil structure were used. Verification was implemented via the field research with the use of the soil probes. Methods affirmed significant presence of the water erosion in the area. Efficient identification of erosional processes is possible via combination of presented methods by taking into consideration geological, geomorphological, pedological and geographical conditions and the use of the area over a longer period of time. The results of using methods that ensure accurate and effective localisation of erosion surfaces can be used for sustainable land use and its conservation.
16
Knapp, F. F., J. Nitsch, J. Kropp, K. Reichmann, C. Winkler, and S. N. Reske. "Ergebnisse der Fettsäure-SPECT des Myokards bei der koronaren Herzerkrankung." Nuklearmedizin 25, no. 03 (1986): 90–98. http://dx.doi.org/10.1055/s-0038-1624324.
Анотація:
New developments in radiopharmacology of 123l-labeled metabolic tracers and single-photon emission computerized tomography (SPECT) allow now-a-days the assessment of parameters of cardiac energy metabolism in well-defined areas of the heart muscle. This article will present a brief outline of the basic pathophysiological principles used in the application of 123l-labeled phenyl fatty acids for the evaluation of CAD. First clinical results suggest an important application of cardiac fatty acid metabolic imaging to the detection, localisation and conceivable quantitation of myocardial ischemia, myocardial infarction and assessment of tissue viability. In addition to the diagnostic applications in CAD, cardiac fatty acid metabolic imaging may provide new perspectives to pathophysiological investigations of the coupling of local flow and substrate utilisation in vivo and the effect of therapeutic interventions.
17
Bayer, Rolf M., and Kaerl-Heinz Lotze. "Bremsstrahlung and Pair Creation by a Photon in the Spacetime of a Cosmic String." International Journal of Modern Physics D 06, no. 06 (December 1997): 693–715. http://dx.doi.org/10.1142/s021827189700042x.
Анотація:
We consider two tree-graph processes in the spacetime of an infinite, straight and static cosmic string, namely Bremsstrahlung and electron–positron pair production. Results based on a simplified model with scalar fields which were obtained by other authors are extended to the more realistic QED case. In empty Minkowski spacetime, energy and momentum conservation preclude these processes. In spite of the local flatness of the metric, it is a topological defect that gives rise to non-conservation of momentum in the plane perpendicular to the string. Analytic expressions for the total transition probabilities and, in the case of Bremsstrahlung, the total radiation energy are found and compared with the results for the scalar field model. In a sense, the cylindrical mode solutions of the Dirac equation allow a spatial localisation of the decay processes relative to the string axis.
18
Hirvonen, Liisa M., Matthew J. Barber, and Klaus Suhling. "Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 820 (June 2016): 121–25. http://dx.doi.org/10.1016/j.nima.2016.03.024.
19
Xu, Ming G., Blessing Crimeen, Mandy J. Ludford-Menting, Xiaosong Gan, Sarah M. Russell, and Min Gu. "Three-dimensional localisation of fluorescence resonance energy transfer in living cells under two-photon excitation." Scanning 23, no. 1 (January 2001): 9–13. http://dx.doi.org/10.1002/sca.4950230102.
20
Eberhardt, W., EW Plummer, CT Chen, and WK Ford. "Deexcitation Electron Spectroscopy: A Probe for the Localisation of Valence Wavefunctions in Free and Adsorbed Molecules." Australian Journal of Physics 39, no. 5 (1986): 853. http://dx.doi.org/10.1071/ph860853.
Анотація:
Deexcitation electron spectroscopy (DES) is the measurement of the kinetic energy distribution of electrons emitted in the decay of highly excited states of molecules formed by core to bound resonant photon absorption. This spectroscopy has the potential of becoming a new probe of the localised properties of the valence electronic states in molecules as well as furnishing new insights into the dynamics of the electronic decay and screening processes. This paper describes the basic principles of DES by following the evolution of the DES spectra in CO, from the isolated CO molecule in the gas phase, through the transition metal carbonyls, to CO adsorbed on a surface. In all three cases the energetics, intensities and dynamics of DES will be compared with photoelectron spectroscopy (PES) and Auger electron spectroscopy (AES).
21
Hussar, Piret, Cristin Allmang, Florina Popovska-Percinic, Tõnu Järveots, and Ilmārs Dūrītis. "Comparative Study of Sodium-Dependent Glucose Co-Transporters in Kidneys of Ostrich Chickens." Scientific Horizons 25, no. 4 (2022): 30–35. http://dx.doi.org/10.48077/scihor.25(4).2022.30-35.
Анотація:
In the changing internal and external conditions, maintenance of a constant internal environment – homeostasis – plays a significant role in the proper functioning of the organism. Kidneys play a key role in the homeostasis of glucose, in which the sodium-dependent glucose co-transporters contribute to renal glucose reabsorption. Although the localisation of Na+-glucose co-transporters has been extensively covered in animals’ kidneys, the localisation of the transporters in birds’ kidneys is still understudied. The purpose of this study was to immunolocalise the sodium-dependent co-transporters SGLT1 and SGLT2 in kidneys of ostrich chickens of different ages. In the study, kidney material derived from fifteen ostriches was divided equally into three age groups – 1-, 7-, and 14-days-old ostrich chickens. The polyclonal antibodies Rabbit antiSGLT1 and Rabbit anti-SGLT2 (Abcam, UK) served as primary antibodies and were used together with the IHC kit (Abcam, UK). With the AxioCam HRc camera (Germany) connected to the microscope Zeiss Axioplan-2 Imaging (Germany), the photos were taken and saved to the computer. As the result of the study on ostrich chickens of different ages, SGLT1 was noted to be localised in the renal straight proximal tubules and SGLT2 in the proximal convoluted tubules of nephron. The immunohistochemical locations of sodium-dependent glucose co-transporters revealed to be similar in ostriches’ kidneys of all age groups. The staining for SGLT2 was noted to be more intensive compared to the staining for SGLT1. As avian kidneys have unique morphological and functional features compared to animals, it is recommended that further studies would be performed on the renal tissue of different avian species
22
Herfurth, N., C. Wu, A. Beyreuther, T. Nakamura, I. De Wolf, M. Simon-Najasek, F. Altmann, K. Croes, and C. Boit. "Non-invasive soft breakdown localisation in low k dielectrics using photon emission microscopy and thermal laser stimulation." Microelectronics Reliability 92 (January 2019): 73–78. http://dx.doi.org/10.1016/j.microrel.2018.11.009.
23
Christakis, I., S. Khan, GP Sadler, FV Gleeson, KM Bradley, and R. Mihai. "18Fluorocholine PET/CT scanning with arterial phase-enhanced CT is useful for persistent/recurrent primary hyperparathyroidism: first UK case series results." Annals of The Royal College of Surgeons of England 101, no. 7 (September 2019): 501–7. http://dx.doi.org/10.1308/rcsann.2019.0059.
Анотація:
Introduction Redo parathyroidectomy for persistent/recurrent primary hyperparathyroidism is associated with a higher risk of complications and should be planned only with convincing localisation. We assessed whether 18fluorocholine positron emission tomography/computed tomography could identify parathyroid adenoma(s) in patients with persistent/recurrent primary hyperparathyroidism and negative conventional scans. Materials and methods A departmental database was used to identify patients with failed localisation attempts (sestamibi single photon emission computed tomography/computed tomography and/or computed tomography/magnetic resonance imaging and/or selective parathyroid hormone sampling) after previous unsuccessful surgery for primary hyperparathyroidism. 18Fluorocholine positron emission tomography was performed in all patients and redo surgery offered to those with positive findings. Results 18Fluorocholine positron emission tomography incorporating arterial and portal phase enhanced computed tomography was performed in 12 patients with persistent/recurrent primary hyperparathyroidism (four men and eight women). Seven patients (58%) were cured after excision of adenomas located in ectopic positions (n = 3) or in anatomical position (n = 4). Five patients (42%) had persistent hypercalcaemia and repeat 18fluorocholine scan confirmed that the area highlighted on preoperative scans was excised. The arterial phase enhancement of the computed tomography was significantly different between cured and not-cured patients (P = 0.007). All seven cured patients had either a strong or weak enhancing pattern on computed tomography. Standardised uptake value at 60 minutes in patients with successful surgery (range 2.7–15.7, median 4.05) was higher than in patients with failed surgery (range 1.8–5.8, median 3.2) but was not statistically significant (P = 0.300). Discussion 18fluorocholine scanning can identify elusive parathyroid adenomas, including those that are ectopic, and is useful in the management of patients with persistent/recurrent primary hyperparathyroidism when first-line scans are negative. The grading of the arterial phase of computed tomography can help to differentiate between true adenomas and false positive targets (lymph nodes).
24
Park, Ariel, Alicia Martin, Ramos Carlos, and Vladimir Neychev. "Primary versus secondary nature of mesenteric neuroendocrine tumours." BMJ Case Reports 14, no. 2 (February 2021): e239217. http://dx.doi.org/10.1136/bcr-2020-239217.
Анотація:
Neuroendocrine tumours (NETs) are rare group of malignancy that originate from neuroendocrine cells present throughout the body. Most patients with NET first present with symptoms associated with metastasis, and up to 20% of patients have unknown primary site of tumour. Most common metastatic sites for small intestine NETs (SI-NETs) are the locoregional lymph nodes and liver. Although mesenteric metastasis through direct extension or lymphatic spread from SI-NETs is common, mesenteric extranodal involvement is extremely rare, and its biology and primary versus secondary nature are not well understood. Due to their small size and location, SI-NETs are frequently undetected on anatomical imaging or indium-111-pentetreotide single-photon emission computed tomography/CT (Octreoscan) and are difficult to be found via endoscopy. Gallium-68-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-octreotate positron emission tomography (68Ga-DOTATATE PET)/CT has been increasingly used for accurate staging, unknown primary tumour site localisation and appropriate management planning. We present a case of an incidentally found mesenteric NET with occult SI-NETs localised preoperatively by 68Ga-DOTATATE PET/CT.
25
de Herder, Wouter W. "GEP-NETs update: Functional localisation and scintigraphy in neuroendocrine tumours of the gastrointestinal tract and pancreas (GEP-NETs)." European Journal of Endocrinology 170, no. 5 (May 2014): R173—R183. http://dx.doi.org/10.1530/eje-14-0077.
Анотація:
For patients with neuroendocrine tumours (NETs) of the gastrointestinal tract and pancreas (GEP) (GEP-NETs), excellent care should ideally be provided by a multidisciplinary team of skilled health care professionals. In these patients, a combination of nuclear medicine imaging and conventional radiological imaging techniques is usually mandatory for primary tumour visualisation, tumour staging and evaluation of treatment. In specific cases, as in patients with occult insulinomas, sampling procedures can provide a clue as to where to localise the insulin-hypersecreting pancreatic NETs. Recent developments in these fields have led to an increase in the detection rate of primary GEP-NETs and their metastatic deposits. Radiopharmaceuticals targeted at specific tumour cell properties and processes can be used to provide sensitive and specific whole-body imaging. Functional imaging also allows for patient selection for receptor-based therapies and prediction of the efficacy of such therapies. Positron emission tomography/computed tomography (CT) and single-photon emission CT/CT are used to map functional images with anatomical localisations. As a result, tumour imaging and tumour follow-up strategies can be optimised for every individual GEP-NET patient. In some cases, functional imaging might give indications with regard to future tumour behaviour and prognosis.
26
Civan, Osman, Özgün Barış Güntürk, Kemal Özaksar, Ali Cavit, and Haluk Özcanli. "Glomus tumors of the nail bed: topographic anatomy and an algorithmic approach based on the topography." Handchirurgie · Mikrochirurgie · Plastische Chirurgie 52, no. 03 (June 2020): 202–6. http://dx.doi.org/10.1055/a-1170-6209.
Анотація:
Abstract Purpose Glomus tumors are rare vascular pathologies characterized by a triad of symptoms: tenderness, pain and cold intolerance. In the hand they are highly concentrated under the nail bed. In this retrospective study, we aimed to present a topographic map of the location of glomus tumors in the nail bed and a map-based surgical approach algorithm to the subungual glomus tumors. Methods We prepared a nail bed map with 6 zones and named these zones as ulnar distal, ulnar proximal, central distal, central proximal, radial distal and radial proximal. With respect to the tumor location and the used surgical approach we retrospectively evaluated the intraoperative photos and the hospital records of patients who were operated between 2008–2019 and had the pathological diagnosis of glomus tumor. The examination records of the postoperative first year were evaluated for each patient retrospectively. A descriptive statistical analysis was performed. In addition we analyzed the described surgical approaches to excise a glomus tumor in the nail bed. The described approaches and the approaches used by us were matched with the localisation of the tumors in this study developing an algorithm for the surgical approach depending on the localisation of the nail bed glomus tumor. Results Finally 44 patients had inclusion criteria. The distribution of the glomus tumor was as follows: 2 were on ulnar distal (4.5 %), 9 on ulnar proximal (20.5 %), 1 on central distal (2.3 %), 18 on central proximal (40.9 %), 4 on radial distal (9.1 %) and 10 were on the radial proximal zones (22.7 %). 4 lateral approaches, 1 nail sparing and 39 transungual approaches were performed. We had one recurrence in a male patient operated by transungual approach. Conclusion Glomus tumors are mostly located on the central proximal part of the nail bed. Our glomus map and the algorithm we described might be helpful for the selection of the surgical approach for the glomus tumor.
27
Al-lami, Ali, Malcolm A. Buchanan, and Andrew G. Pfleiderer. "ASIT-AOT prize winner: How useful is single-photon emission computed tomography (SPECT) in predicting localisation of parathyroid adenomas?" International Journal of Surgery 11, no. 8 (October 2013): 639. http://dx.doi.org/10.1016/j.ijsu.2013.06.283.
28
Castro-Balado, Ana, Cristina Mondelo-García, Miguel González-Barcia, Irene Zarra-Ferro, Francisco J. Otero-Espinar, Álvaro Ruibal-Morell, Pablo Aguiar, and Anxo Fernández-Ferreiro. "Ocular Biodistribution Studies Using Molecular Imaging." Pharmaceutics 11, no. 5 (May 16, 2019): 237. http://dx.doi.org/10.3390/pharmaceutics11050237.
Анотація:
Classical methodologies used in ocular pharmacokinetics studies have difficulties to obtain information about topical and intraocular distribution and clearance of drugs and formulations. This is associated with multiple factors related to ophthalmic physiology, as well as the complexity and invasiveness intrinsic to the sampling. Molecular imaging is a new diagnostic discipline for in vivo imaging, which is emerging and spreading rapidly. Recent developments in molecular imaging techniques, such as positron emission tomography (PET), single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI), allow obtaining reliable pharmacokinetic data, which can be translated into improving the permanence of the ophthalmic drugs in its action site, leading to dosage optimisation. They can be used to study either topical or intraocular administration. With these techniques it is possible to obtain real-time visualisation, localisation, characterisation and quantification of the compounds after their administration, all in a reliable, safe and non-invasive way. None of these novel techniques presents simultaneously high sensitivity and specificity, but it is possible to study biological procedures with the information provided when the techniques are combined. With the results obtained, it is possible to assume that molecular imaging techniques are postulated as a resource with great potential for the research and development of new drugs and ophthalmic delivery systems.
29
Maitra, C., J. Ballet, P. Esposito, F. Haberl, A. Tiengo, M. D. Filipović, and F. Acero. "Probing the nature of AX J0043−737: Not an 87 ms pulsar in the Small Magellanic Cloud." Astronomy & Astrophysics 612 (April 2018): A87. http://dx.doi.org/10.1051/0004-6361/201732239.
Анотація:
Aims. AX J0043−737 is a source in the ASCA catalogue whose nature is uncertain. It is most commonly classified as a Crab-like pulsar in the Small Magellanic Cloud (SMC) following apparent detection of pulsations at ~87 ms from a single ASCA observation. A follow-up ASCA observation was not able to confirm this, and the X-ray detection of the source has not been reported since. Methods. We studied the nature of the source with a dedicated XMM-Newton observation. We ascertained the source position, searched for the most probable counterpart, and studied the X-ray spectrum. We also analysed other archival observations with the source in the field of view to study its long-term variability. Results. With the good position localisation capability of XMM-Newton, we identify the counterpart of the source as MQS J004241.66–734041.3, an active galactic nucleus (AGN) behind the SMC at a redshift of 0.95. The X-ray spectrum can be fitted with an absorbed power law with a photon-index of Γ = 1.7, which is consistent with that expected from AGNs. By comparing the current XMM-Newton observation with an archival XMM-Newton and two other ASCA observations of the source, we find signatures of long-term variability, another common phenomenon in AGNs. All of the above are consistent with AX J0043−737 being an AGN behind the SMC.
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Balukova, Andrea, Kalliopi Bokea, Paul R. Barber, Simon M. Ameer-Beg, Alexander J. MacRobert, and Elnaz Yaghini. "Cellular Imaging and Time-Domain FLIM Studies of Meso-Tetraphenylporphine Disulfonate as a Photosensitising Agent in 2D and 3D Models." International Journal of Molecular Sciences 25, no. 8 (April 11, 2024): 4222. http://dx.doi.org/10.3390/ijms25084222.
Анотація:
Fluorescence lifetime imaging (FLIM) and confocal fluorescence studies of a porphyrin-based photosensitiser (meso-tetraphenylporphine disulfonate: TPPS2a) were evaluated in 2D monolayer cultures and 3D compressed collagen constructs of a human ovarian cancer cell line (HEY). TPPS2a is known to be an effective model photosensitiser for both Photodynamic Therapy (PDT) and Photochemical Internalisation (PCI). This microspectrofluorimetric study aimed firstly to investigate the uptake and subcellular localisation of TPPS2a, and evaluate the photo-oxidative mechanism using reactive oxygen species (ROS) and lipid peroxidation probes combined with appropriate ROS scavengers. Light-induced intracellular redistribution of TPPS2a was observed, consistent with rupture of endolysosomes where the porphyrin localises. Using the same range of light doses, time-lapse confocal imaging permitted observation of PDT-induced generation of ROS in both 2D and 3D cancer models using fluorescence-based ROS together with specific ROS inhibitors. In addition, the use of red light excitation of the photosensitiser to minimise auto-oxidation of the probes was investigated. In the second part of the study, the photophysical properties of TPPS2a in cells were studied using a time-domain FLIM system with time-correlated single photon counting detection. Owing to the high sensitivity and spatial resolution of this system, we acquired FLIM images that enabled the fluorescence lifetime determination of the porphyrin within the endolysosomal vesicles. Changes in the lifetime dynamics upon prolonged illumination were revealed as the vesicles degraded within the cells.
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Townsend, DW. "Physical Principles and Technology of Clinical PET Imaging." Annals of the Academy of Medicine, Singapore 33, no. 2 (March 15, 2004): 133–45. http://dx.doi.org/10.47102/annals-acadmedsg.v33n2p133.
Анотація:
Molecular imaging with positron-emitting radionuclides is playing an increasingly important role in the diagnosis and staging of malignant disease and in monitoring response to therapy. To meet this challenge, significant improvements in the performance of the imaging technology have been achieved in recent years. Such developments are subject to the constraints imposed by the physics of positron emission tomography (PET) and the main objectives in designing or improving PET scanners are to achieve high spatial resolution and sensitivity while maximising the true coincidence count rate relative to contributions from noise processes. Noise contributions in PET include not only statistical effects associated with photon counting but also background processes such as scatter and random coincidences. The recent developments of new, faster scintillators and electronics for PET detectors, as well as statistically-based algorithms that reconstruct fully three-dimensional (3D) PET images in minutes, have dramatically reduced clinical imaging times while improving image quality. A recent advance, the combination of functional imaging and computed tomography (CT) in the PET/CT scanner has further reduced the study duration by eliminating the lengthy PET transmission scan and providing accurate anatomical localisation of functional abnormalities. PET imaging technology has now improved to where a combined anatomical and functional clinical study can be completed in less than 10 minutes – although taking advantage of such high throughput potential will challenge patient management in diagnostic imaging departments. This paper reviews the physical principles underlying PET and summarises the recent developments in PET scanner technology, from the introduction of new PET detectors to the development of the combined PET/CT scanner.
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Duncan, Roderick. "SPECT in Focal Epilepsies." Behavioural Neurology 12, no. 1-2 (2000): 69–75. http://dx.doi.org/10.1155/2000/904719.
Анотація:
Brain perfusion changes during seizures were first observed in the 1930s. Single Photon Emission Computed Tomography (SPECT) was developed in the 1970s, and tracers suitable for the imaging of regional cerebral perfusion (rCP) became available in the 1980s. The method was first used to study rCP in the interictal phase, and this showed areas of low perfusion in a proportion of cases, mainly in patients with temporal lobe epilepsies. However, the trapping paradigm of tracers such as hexamethyl propyleneamine oxime (HMPAO) provided a practicable method of studying changes in rCP during seizures, and a literature was established in the late 1980s and early 1990s showing a typical sequence of changes during and after seizures of mesial temporal lobe origin; the ictal phase was associated with large increases in perfusion throughout the temporal lobe, with first the lateral, then the mesial temporal lobe becoming hypoperfused in the postictal phase. Activation and inhibition of other structures, such as the basal ganglia and frontal cortex, were also seen. Studies of seizures originating elsewhere in the brain have shown a variety of patterns of change, according to the structures involved. These changes have been used practically to aid the process of localisation of the epileptogenic zone so that epilepsy surgery can be planned.Some neuroreceptors (e.g. benzodiazepine receptors) can be studied using SPECT, and have shown localised abnormalities. SPECT has also been used to study brain function during the intracarotid amytal test. SPECT images of all kinds can be analysed using numerical techniques such as statistical parametric mapping, and such techniques promise to improve the yield of information from ictal studies.
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Prat, Lionel, Cheryl Baker, and Nhien An Le-Khac. "MapExif." International Journal of Digital Crime and Forensics 7, no. 2 (April 2015): 53–78. http://dx.doi.org/10.4018/ijdcf.2015040104.
Анотація:
Recently, the integration of geographical coordinates into a picture has become more and more popular. Indeed almost all smartphones and many cameras today have a built-in GPS receiver that stores the location information in the Exif header when a picture is taken. Although the automatic embedding of geotags in pictures is often ignored by smart phone users as it can lead to endless discussions about privacy implications, these geotags could be really useful for investigators in analysing criminal activity. Currently, there are many free tools as well as commercial tools available in the market that can help computer forensics investigators to cover a wide range of geographic information related to criminal scenes or activities. However, there are not specific forensic tools available to deal with the geolocation of pictures taken by smart phones or cameras. In this paper, an image scanning and mapping tool for investigators is proposed and developed. This tool scans all the files in a given directory and then displays particular photos based on optional filters (date/time/device/localisation…) on Google Map. The file scanning process is not based on the file extension but its header. This tool can also show efficiently to users if there is more than one image on the map with the same GPS coordinates, or even if there are images with no GPS coordinates taken by the same device in the same timeline. Moreover, this new tool is portable; investigators can run it on any operating system without any installation. Another useful feature is to be able to work in a read-only environment, so that forensic results will not be modified. This tool's real-world application is also presented and evaluated in this paper.
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Pountos, Ippokratis, Christel Charpail, and Nazzar Tellisi. "Evaluation of the Diagnostic Value of SPECT/CT in Defining Foot and Ankle Pathologies." Foot & Ankle Orthopaedics 4, no. 4 (October 1, 2019): 2473011419S0006. http://dx.doi.org/10.1177/2473011419s00062.
Анотація:
Category: Ankle Arthritis, Hindfoot, Midfoot/Forefoot Introduction/Purpose: The precise localisation of degenerative or inflammatory pathologies in foot and ankle can be difficult due to the complex anatomy of the joints. MRI plays a vital diagnostic role in these scenarios aiding the diagnosis and preoperative planning. Single-photon emission computed tomography combined with computed tomography (SPECT/CT) is a relatively new imaging technology that combines the sensitivity of nuclear medicine examinations with the anatomical detail of CT. The aim of this study is to analyse the diagnostic effectiveness of SPECT/CT in evaluating foot and ankle pathologies. Methods: The authors retrospectively reviewed the medical records of all patients with a foot and/or ankle -related complaint that received SPECT/CT. Exclusion criteria included patients with inadequate follow-up and those that were not initially assessed by a senior foot and ankle surgeon. Collected data included demographic information, results from imaging, clinical progress and outcomes. Results: 272 included in the study comprised of 156 females and 116 males with a mean age of 52,8 years (range 17-92 years). The acquisition of a SPECT/CT changed the initial diagnosis (from either clinical or radiographs or MRI) in 55% of the cases. SPECT/CT finding correlated with MRI only in 34% of the cases. From the remaining cases SPECT/CT partially correlated with MRI in 26% of cases no correlation was noted in 40%. In regards to patients that undergone a USS or CT guided injection following the finding of a SPECT/CT, 86% reported a transient or long-term improvement in the pain. Overall, the SPECT/CT added confidence to the clinical diagnosis in 89% of the cases while reduced the need of further investigations in 93%. Conclusion: SPECT/CT is a valuable tool in depicting foot and ankle pathologies. It was able to provide additional diagnostic value by demonstrating co-existing pathologies as a potential cause of pain. SPECT/CT and MRI exhibit different diagnostic specificity and the limitations of each scan should be taken into consideration. This study strongly supports the use of SPECT/CT as a complementary imaging method to MRI for enhancing diagnostic specificity and outcomes.
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Weismuller, P., M. Clausen, R. Weller, P. Richter, J. Steinmann, E. Henze, I. Dormehl, M. Kochs, W. E. Adam, and V. Hombach. "Non-invasive three-dimensional localisation of arrhythmogenic foci in Wolff-Parkinson-White syndrome and in ventricular tachycardia by radionuclide ventriculography: phase analysis of double-angulated integrated single photon emission computed tomography (SPECT)." Heart 69, no. 3 (March 1, 1993): 201–10. http://dx.doi.org/10.1136/hrt.69.3.201.
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Rix, Larissa, Samuel Tushingham, Karina Wright, and Martyn Snow. "EVALUATING THE UTILITY OF SPECT/CT FOR THE IDENTIFICATION OF CARTILAGE LESIONS: A SYSTEMATIC REVIEW." Orthopaedic Proceedings 105-B, SUPP_16 (November 17, 2023): 45. http://dx.doi.org/10.1302/1358-992x.2023.16.045.
Анотація:
AbstractObjectiveA common orthopaedic pain found in a wide spectrum of individuals, from young and active to the elderly is anterior knee pain (AKP). It is a multifactorial disorder which is thought to occur through muscular imbalance, overuse, trauma, and structural malalignment. Over time, this can result in cartilage damage and subsequent chondral lesions. Whilst the current gold standard for chondral lesion detection is MRI, it is not a highly sensitive tool, with around 20% of lesions thought to be mis-diagnosed by MRI. Single-photon emission computerised tomography with conventional computer tomography (SPECT/CT) is an emerging technology, which may hold clinical value for the detection of chondral lesions. SPECT/CT may provide valuable diagnostic information for AKP patients who demonstrate absence of structural change on other imaging modalities. This review systematically assessed the value of SPECT/CT as an imaging modality for knee pain, and its ability to diagnose chondral lesions for patients who present with knee pain.MethodsUsing PRISMA guidelines, a systematic search was carried out in PubMed, Science Direct, and Web of Knowledge, CINAHL, AMED, Ovid Emcare and Embase. Inclusion criteria consisted of any English language article focusing on the diagnostic value of SPECT/CT for knee chondral lesions and knee pain. Furthermore, animal or cadaver studies, comparator technique other than SPECT/CT or patients with a pathology other than knee chondral lesions were excluded from the study. Relevant articles underwent QUADAS-2 bias assessment.Results11,982 manuscripts were identified, and the titles were screened for relevance. Seven studies were selected as being appropriate and were subjected to QUADAS-2 assessment. All 7 articles scored low for bias. Two papers deemed that the ICRS score of chondral lesions at intraoperative assessment correlated with SPECT/CT tracer uptake. Two studies concluded that MRI significantly correlated with SPECT/CT tracer uptake, with some instances whereby SPECT/CT identified more chondral lesions than MRI. Two papers compared bone scintigraphy (BS) to SPECT/CT and concluded that SPECT/CT was not only able to identify more chondral lesions than BS, but also localise and characterise the lesions.ConclusionEvidence implies that SPECT/CT may be a useful imaging modality for the detection and localisation of cartilage lesions, particularly in discrepant cases whereby there is an absence of lesions on other imaging modalities, or a lack of correspondence with patients’ symptoms. More studies would be of value to confirm the conclusions of this review.Declaration of Interest(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
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Qudrat, Fatiha, and Sunil Patil. "Enhanced Adaptive Over-Segmentation Technique for Image Forgery Detection under Noise Attacks." International Journal of Computer Science and Mobile Computing 12, no. 10 (October 30, 2023): 34–44. http://dx.doi.org/10.47760/ijcsmc.2023.v12i10.004.
Анотація:
The problem of picture fraud has become more pervasive in the current digital era as a direct result of the ease with which complex image manipulation programs can be accessed. This research study provides a comprehensive analysis of several methodologies and approaches that are used to detect and localize cases of picture fraud. The primary objective is to provide a clear understanding of the most cutting-edge methods that are now being utilized, as well as the problems and opportunities that lie ahead. In the field of picture forensics, the focus of this article is on several distinct types of image fraud, such as copy-move, splicing, retouching, and inpainting forgeries. We study the underlying principles that lie behind frequently used detection methods, such as block matching, feature-based analysis, and approaches that are anchored in deep learning. In addition, we go over the benefits and drawbacks of each strategy, focusing on how they apply to a variety of settings. In addition, this article takes a look at the datasets that are typically utilized for the training and evaluation of forgery detection algorithms, highlighting both the benefits and the limitations of those datasets. In addition to this, we examine the numerous assessment metrics that are utilized in order to evaluate the performance of the various methods, with a particular focus on the requirement for standardized benchmark datasets and evaluation methodologies. In addition, we discuss the obstacles that are presented when attempting to identify picture fraud in the real world. These issues include the need to deal with photos that have been compressed, images that have varying resolutions, and the existence of post-processing effects. In this article, we will discuss the significance of multi-modal analysis and the fusion of information obtained from a variety of sources in order to improve the reliability of counterfeit detection systems. The approaches that are used to detect picture counterfeiting are the topic of the next section of this review. We look at several techniques, such as those based on segmentation, texture analysis, and deep neural networks, in order to determine the precise position of forged sections inside a picture. We go through their precision, the amount of computing complexity they have, and the possible uses they have. In conclusion, we discuss the potential of the future. In order to identify and localize forged images, it is necessary to keep up with the latest innovations in image editing software and build forgery detection systems that are more technologically advanced and effective. This is because picture editing techniques are always being refined and improved. We offer prospective research avenues, such as Explainable AI, Generative Adversarial Networks (GANs) for forgeries production, and hybrid techniques to combine the strengths of various detection methods. Specifically, we focus on hybrid approaches to combine the strengths of diverse detection methods. In conclusion, the purpose of this study is to offer academics and industry professionals in This article provides a comprehensive review of the present state of identifying and localizing picture forgeries, which falls under the umbrella of image forensics as a discipline. It encompasses the most recent developments in forgery detection and localisation, making it possible to gain an in-depth comprehension of the subject matter. It is possible to pave the way for more effective and reliable forgery detection systems to protect the integrity of digital pictures in a variety of applications if we grasp the existing approaches as well as the obstacles that they provide.
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Stokes, Adam, Hannah Riley, and Ahsan Nazir. "The Gauge-Relativity of Quantum Light, Matter, and Information." Open Systems & Information Dynamics 30, no. 03 (September 2023). http://dx.doi.org/10.1142/s1230161223500166.
Анотація:
We describe the physical relativity of light and matter quantum subsystems, their correlations, and energy exchanges. We examine the most commonly adopted definitions of atoms and photons, noting the significant difference in their localisation properties when expressed in terms of primitive manifestly gauge-invariant and local fields. As a result, different behaviours for entanglement generation and energy exchange occur for different definitions. We explore such differences in detail using toy models of a single photonic mode interacting with one and two dipoles.
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Burderi, L., A. Sanna, T. Di Salvo, L. Amati, G. Amelino-Camelia, M. Branchesi, S. Capozziello, et al. "GrailQuest: hunting for atoms of space and time hidden in the wrinkle of Space-Time." Experimental Astronomy, August 3, 2021. http://dx.doi.org/10.1007/s10686-021-09745-5.
Анотація:
AbstractGrailQuest (Gamma Ray Astronomy International Laboratory for QUantum Exploration of Space-Time) is a mission concept based on a constellation (hundreds/thousands) of nano/micro/small-satellites in low (or near) Earth orbits. Each satellite hosts a non-collimated array of scintillator crystals coupled with Silicon Drift Detectors with broad energy band coverage (keV-MeV range) and excellent temporal resolution (≤ 100 nanoseconds) each with effective area $\sim 100 \text {cm}^{2}$ ∼ 100 cm 2 . This simple and robust design allows for mass-production of the satellites of the fleet. This revolutionary approach implies a huge reduction of costs, flexibility in the segmented launching strategy, and an incremental long-term plan to increase the number of detectors and their performance; this will result in a living observatory for next-generation, space-based astronomical facilities. GrailQuest is conceived as an all-sky monitor for fast localisation of high signal-to-noise ratio transients in the X-/gamma-ray band, e.g. the elusive electromagnetic counterparts of gravitational wave events. Robust temporal triangulation techniques will allow unprecedented localisation capabilities, in the keV-MeV band, of a few arcseconds or below, depending on the temporal structure of the transient event. The ambitious ultimate goal of this mission is to perform the first experiment, in quantum gravity, to directly probe space-time structure down to the minuscule Planck scale, by constraining or measuring a first-order dispersion relation for light in vacuo. This is obtained by detecting delays between photons of different energies in the prompt emission of Gamma-Ray Bursts.
40
Li, Shuo, Wenchao Li, Qiang Sun, Bill Moran, Timothy C. Brown, Brant Gibson, and Andrew D. Greentree. "Localising two sub-diffraction emitters in 3D using quantum correlation microscopy." New Journal of Physics, March 8, 2024. http://dx.doi.org/10.1088/1367-2630/ad31d4.
Анотація:
Abstract The localisation of fluorophores is an important aspect of determining the biological function of cellular systems. Quantum correlation microscopy (QCM) is a promising technique for providing diffraction unlimited emitter localisation that can be used with either confocal or widefield modalities. However, so far, QCM has not been applied to three dimensional localisation problems. Here we show that quantum correlation microscopy provides diffraction-unlimited three-dimensional localisation for two emitters within a single diffraction-limited spot. By introducing a two-stage maximum likelihood estimator, our modelling shows that the localisation precision scales as 1/√t where t is the total detection time. Diffraction unlimited localisation is achieved using both intensity and photon correlation from Hanbury Brown and Twiss measurements at as few as four measurement locations. We also compare the results of (MC) simulations with the Cramer-Rao Lower Bound.
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Bebbington, Natalie A., Bryan T. Haddock, Henrik Bertilsson, Eero Hippeläinen, Ellen M. Husby, Virpi I. Tunninen, and Marcus Söderberg. "A Nordic survey of CT doses in hybrid PET/CT and SPECT/CT examinations." EJNMMI Physics 6, no. 1 (December 2019). http://dx.doi.org/10.1186/s40658-019-0266-7.
Анотація:
Abstract Background Computed tomography (CT) scans are routinely performed in positron emission tomography (PET) and single photon emission computed tomography (SPECT) examinations globally, yet few surveys have been conducted to gather national diagnostic reference level (NDRL) data for CT radiation doses in positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography/computed tomography (SPECT/CT). In this first Nordic-wide study of CT doses in hybrid imaging, Nordic NDRL CT doses are suggested for PET/CT and SPECT/CT examinations specific to the clinical purpose of CT, and the scope for optimisation is evaluated. Data on hybrid imaging CT exposures and clinical purpose of CT were gathered for 5 PET/CT and 8 SPECT/CT examinations via designed booklet. For each included dataset for a given facility and scanner type, the computed tomography dose index by volume (CTDIvol) and dose length product (DLP) was interpolated for a 75-kg person (referred to as CTDIvol,75kg and DLP75kg). Suggested NDRL (75th percentile) and achievable doses (50th percentile) were determined for CTDIvol,75kg and DLP75kg according to clinical purpose of CT. Differences in maximum and minimum doses (derived for a 75-kg patient) between facilities were also calculated for each examination and clinical purpose. Results Data were processed from 83 scanners from 43 facilities. Data were sufficient to suggest Nordic NDRL CT doses for the following: PET/CT oncology (localisation/characterisation, 15 systems); infection/inflammation (localisation/characterisation, 13 systems); brain (attenuation correction (AC) only, 11 systems); cardiac PET/CT and SPECT/CT (AC only, 30 systems); SPECT/CT lung (localisation/characterisation, 12 systems); bone (localisation/characterisation, 30 systems); and parathyroid (localisation/characterisation, 13 systems). Great variations in dose were seen for all aforementioned examinations. Greatest differences in DLP75kg for each examination, specific to clinical purpose, were as follows: SPECT/CT lung AC only (27.4); PET/CT and SPECT/CT cardiac AC only (19.6); infection/inflammation AC only (18.1); PET/CT brain localisation/characterisation (16.8); SPECT/CT bone localisation/characterisation (10.0); PET/CT oncology AC only (9.0); and SPECT/CT parathyroid localisation/characterisation (7.8). Conclusions Suggested Nordic NDRL CT doses are presented according to clinical purpose of CT for PET/CT oncology, infection/inflammation, brain, PET/CT and SPECT/CT cardiac, and SPECT/CT lung, bone, and parathyroid. The large variation in doses suggests great scope for optimisation in all 8 examinations.
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Bajoni, Daniele, Oreste Nicrosini, Alberto Rimini, and Simone Rodini. "Collapse dynamics and Hilbert-space stochastic processes." Scientific Reports 11, no. 1 (November 12, 2021). http://dx.doi.org/10.1038/s41598-021-00737-1.
Анотація:
AbstractSpontaneous collapse models of state vector reduction represent a possible solution to the quantum measurement problem. In the present paper we focus our attention on the Ghirardi–Rimini–Weber (GRW) theory and the corresponding continuous localisation models in the form of a Brownian-driven motion in Hilbert space. We consider experimental setups in which a single photon hits a beam splitter and is subsequently detected by photon detector(s), generating a superposition of photon-detector quantum states. Through a numerical approach we study the dependence of collapse times on the physical features of the superposition generated, including also the effect of a finite reaction time of the measuring apparatus. We find that collapse dynamics is sensitive to the number of detectors and the physical properties of the photon-detector quantum states superposition.
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Vasquez-Lozano, Jaret Jason, Shuo Li, and Andrew D. Greentree. "Scanning quantum correlation microscopy with few emitters." New Journal of Physics, March 8, 2024. http://dx.doi.org/10.1088/1367-2630/ad31d5.
Анотація:
Abstract Optical superresolution microscopy is an important field, where nonlinear optical processes or prior information is used to defeat the classical diffraction limit of light. Quantum correlation microscopy uses photon arrival statistics from single photon emitters to aid in the determination of properties including the number of emitters and their relative brightness. Here we model quantum correlation microscopy in the few emitter regime, i.e. around four single photon emitters below the diffraction limit. We use the Akaike Information Criterion to determine the number of emitters and we vary the relative contributions of intensity to quantum correlation information to determine contribution that provides optimal imaging. Our results show diffraction unlimited performance and a change in localisation scaling behaviour dependent on emitter closeness.
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Yunusa, Garba H., and Anita Brink. "Assessment of the impact of application of singlephoton emission computed tomography and SPECT-CT on lesion categorisation in bone scintigraphy." South African Journal of Radiology 20, no. 1 (June 29, 2016). http://dx.doi.org/10.4102/sajr.v20i1.990.
Анотація:
Objectives: To assess initial experience with the use of a new single-photon emission computed tomography-computed tomography (SPECT-CT) in the evaluation of lesions.Methods: The folder number, radiopharmaceutical used and type of scan of patients examined with a new Siemens T6 SPECT-CT between 02 April 2016 and 31 December 2013 were retrieved. The number of 99mTc-MDP bone scans was sufficient for a detailed analysis. The scans were re-processed and reported by the observer before he was given any clinical information. Whole body planar, whole body planar plus SPECT and whole body planar plus SPECT-CT images were assessed successively in three separate sessions at least 2 weeks apart. At each session, the certainties of detection, localisation and categorisation of each lesion were recorded.Results: A total of 539 lesions were seen on the whole body, SPECT and computed tomography (CT) images in 133 patients. The whole body images showed no lesions in 3 patients and 378 lesions in 130 patients. SPECT detected 122 additional lesions in 79 patients. Thirty-nine (12.2%) lesions were seen only on CT in 32 (24.1%) patients. For the 261 lesions seen on the planar images in the SPECT field of view, lesion detection was definite in 233 (89.3%), localisation definite in 151 (57.9%) and categorisation definite in 123 (47.1%) lesions. On the SPECT, definite lesion detection, localisation and categorisation were recorded, respectively, for 259 (99.2%), 228 (87.4%) and 176 (67.4%) of the 261 lesions. Lesion detection, localisation and categorisation certainties were definite for 100%, 99.1% and 94.7% of the SPECT-CT lesions, respectively.Conclusion: SPECT markedly improves lesion detection and localisation, and CT enhances lesion categorisation.
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Razi, Mairah, Humayun Bashir, Saima Riaz, and Zia S. Faruqui. "INTRAOSSEOUS HAEMANGIOMAS ON HYBRID IMAGING: A PICTORIAL REVIEW." Journal of Cancer & Allied Specialties 2, no. 2 (August 31, 2016). http://dx.doi.org/10.37029/jcas.v2i2.69.
Анотація:
Osseous haemangiomas are benign skeletal tumours, usually identi ed as incidental ndings on different imaging modalities. Bone scan is the most frequent radionuclide procedure performed as metastatic workup in patients with various malignancies. Not every hotspot on a staging bone scan is malignant. Haemangiomas with variable degree of radiotracer uptake on technetium-99m (Tc-99m) bone scintigraphy may be falsely labelled as metastases in background of known malignancy. The addition of single-photon emission computed tomography computed tomography (SPECT-CT) enhances the specificity of bone scan which allows accurate detection and anatomical localisation of scintigraphic findings. We present a case series as pictorial review of osseous haemangiomas identi ed on Tc-99m methylene diphosphonate SPECT CT at our department. Key words: Haemangioma, methylene diphosphonate, bone scan, single-photon emission computed tomography- computed tomography
46
Barone, Giulio, Gianniantonio Domina, and Emilio Di Gristina. "Comparison of different methods to assess the distribution of alien plants along the road network and use of Google Street View panoramas interpretation in Sicily (Italy) as a case study." Biodiversity Data Journal 9 (May 27, 2021). http://dx.doi.org/10.3897/bdj.9.e66013.
Анотація:
The survey by foot in the field is compared to the survey from a car, the photo-interpretation of Google Street View (GSV) panoramas continuously and at intervals of 1.5 km and the photo-interpretation of Google Earth aerial images on a 10 km stretch of road in Sicily. The survey by foot was used as reference for the other methods. The interpretation of continuous GSV panoramas gave similar results as the assessment by car in terms of the number of species identified and their location, but with lower cost. The interpretation online of aerial photos allowed the identification of a limited number of taxa, but gave a good localisation for them. Interpretation of GSV panoramas, each of 1.5 km, allowed the recognition of twice as many taxa as the interpretation of aerial photos and taking half the time, but did not allow a complete localisation. None of these methods alone seems sufficient to carry out a complete survey. A mixture of different techniques, which may vary according to the available resources and the goal to be achieved, seems to be the best compromise. To further test the capabilities of the survey using the interpretation of GSV panoramas every 1.5 km along the roads, we proceeded to study the alien plants along 3500 km of the road network on the island of Sicily. This survey identified only 10% of the known species for the region, but allowed us to trace the distribution of invasive species whose distribution is currently poorly recorded.
47
Ho, Joon, Donggyu Kim, Ji-Eun Lee, Namki Hong, Byung Moon Kim, Dong Joon Kim, Jinkyong Kim, et al. "Parathyroid venous sampling for the preoperative localisation of parathyroid adenoma in patients with primary hyperparathyroidism." Scientific Reports 12, no. 1 (April 29, 2022). http://dx.doi.org/10.1038/s41598-022-11238-0.
Анотація:
AbstractPreoperative localisation studies are essential for parathyroidectomy in patients with primary hyperparathyroidism. If the location of abnormal parathyroid glands cannot be identified through non-invasive studies, parathyroid venous sampling (PVS) may be employed. In this study, we evaluated the utility of preoperative PVS in parathyroid surgery. Patients with primary hyperparathyroidism who underwent preoperative PVS at Severance Hospital between January 2015 and June 2020 were identified. Patients for whom the results of non-invasive imaging studies were inconsistent or negative underwent PVS. The results of PVS were compared with operative findings and pathologic results. For 14 patients, the results of preoperative ultrasonography and 99mTc-sestamibi single-photon emission computed tomography (SPECT) were negative; for 20 patients, either the result of only one test was positive, or the results of the two tests were inconsistent. With respect to the lateralisation of diseased adenoma, the results of PVS and pathological examination were inconsistent only for one patient in either group (total: 2/34 patients). This study showed that PVS could be used effectively for preoperative localisation in patients with primary hyperparathyroidism in whom the location of diseased parathyroid glands cannot be determined through non-invasive image studies.
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Dávila, M. E., J. Ávila, I. R. Colambo, D. B. Putungan, D. P. Woodruff, and M. C. Asensio. "New insight on the role of localisation in the electronic structure of the Si(111)(7 × 7) surfaces." Scientific Reports 11, no. 1 (July 22, 2021). http://dx.doi.org/10.1038/s41598-021-94664-w.
Анотація:
AbstractNew angle-resolved photoelectron spectroscopy (ARPES) data, recorded at several different photon energies from the Si(111)(7 × 7) surface, show that the well-known S1 and S2 surface states that lie in the bulk band gap are localised at specific (adatom and rest atom) sites on the reconstructed surface. The variations in the photoemission intensity from these states as a function of polar and azimuthal emission angle, and incident photon energy, are not consistent with Fermi surface mapping but are well-described by calculations of the multiple elastic scattering in the final state. This localisation of the most shallowly bound S1 state is consistent with the lack of significant dispersion, with no evidence of Fermi surface crossing, implying that the surface is not, as has been previously proposed, metallic in character. Our findings highlight the importance of final state scattering in interpreting ARPES data, an aspect that is routinely ignored and can lead to misleading conclusions.
49
Weinberg, Phillip, and Marin Bukov. "QuSpin: a Python package for dynamics and exact diagonalisation of quantum many body systems part I: spin chains." SciPost Physics 2, no. 1 (February 13, 2017). http://dx.doi.org/10.21468/scipostphys.2.1.003.
Анотація:
We present a new open-source Python package for exact diagonalisation and quantum dynamics of spin(-photon) chains, called QuSpin, supporting the use of various symmetries in 1-dimension and (imaginary) time evolution for chains up to 32 sites in length. The package is well-suited to study, among others, quantum quenches at finite and infinite times, the Eigenstate Thermalisation hypothesis, many-body localisation and other dynamical phase transitions, periodically-driven (Floquet) systems, adiabatic and counter-diabatic ramps, and spin-photon interactions. Moreover, QuSpin's user-friendly interface can easily be used in combination with other Python packages which makes it amenable to a high-level customisation. We explain how to use QuSpin using four detailed examples: (i) Standard exact diagonalisation of XXZ chain (ii) adiabatic ramping of parameters in the many-body localised XXZ model, (iii) heating in the periodically-driven transverse-field Ising model in a parallel field, and (iv) quantised light-atom interactions: recovering the periodically-driven atom in the semi-classical limit of a static Hamiltonian.
50
Kessler, Laurell F., Ashwin Balakrishnan, Nina S. Deußner‐Helfmann, Yunqing Li, Maximilian Mantel, Marius Glogger, Hans‐Dieter Barth, Marina S. Dietz, and Mike Heilemann. "Self‐quenched Fluorophore Dimers for DNA‐PAINT and STED Microscopy." Angewandte Chemie International Edition, August 23, 2023. http://dx.doi.org/10.1002/anie.202307538.
Анотація:
AbstractSuper‐resolution techniques like single‐molecule localisation microscopy (SMLM) and stimulated emission depletion (STED) microscopy have been extended by the use of non‐covalent, weak affinity‐based transient labelling systems. DNA‐based hybrid systems are a prominent example among these transient labelling systems, offering excellent opportunities for multi‐target fluorescence imaging. However, these techniques suffer from higher background relative to covalently bound fluorophores, originating from unbound fluorophore‐labelled single‐stranded oligonucleotides. Here, we introduce short‐distance self‐quenching in fluorophore dimers as an efficient mechanism to reduce background fluorescence signal, while at the same time increasing the photon budget in the bound state by almost 2‐fold. We characterise the optical and thermodynamic properties of fluorophore‐dimer single‐stranded DNA, and show super‐resolution imaging applications with STED and SMLM with increased spatial resolution and reduced background.