Radioisotopic purity and imaging properties of cyclotron-produced 99mTc using direct 100Mo(p,2n) reaction

Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. Within 15-20 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotrons already available in the nuclear medicine departments of hospitals. The main motivation for such a study is in the framework of the research activities at the international level that have been conducted over the last few years to develop alternative production routes for the most widespread radioisotope used in medical imaging. The analysis of technetium isotopes and isomeric states (9xTc) present in the pertechnetate saline Na99mTcO4 solutions, obtained after the extraction/purification procedure, reveals radionuclidic purity levels basically in compliance with the limits recently issued by European Pharmacopoeia 9.3 (2018 Sodium pertechnetate (99mTc) injection 4801-3). Moreover, the impact of 9xTc contaminant nuclides on the final image quality is thoroughly evaluated, analyzing the emitted high-energy gamma rays and their influence on the image quality. The spatial resolution of images from cyclotron-produced 99mTc acquired with a mini-gamma camera was determined and compared with that obtained using technetium-99m solutions eluted from standard 99Mo/99mTc generators. The effect of the increased image background contribution due to Compton-scattered higher-energy gamma rays (Eγ > 200 keV), which could cause image-contrast deterioration, was also studied. It is concluded that, due to the high radionuclidic purity of cyclotron-produced 99mTc using 100Mo(p,2n)99mTc reaction at a proton beam energy in the range 15.7-19.4 MeV, the resulting image properties are well comparable with those from the generator-eluted 99mTc

SILENT KIDNEY AND TUMOURS OF THE UROGENITAL SYSTEM

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Quantum Critical Point of the XY Model and Condensation of Field-Induced Quasiparticles in Dimer Compounds

The quantum critical point of the three-dimensional XY model in a symmetry-preserving field is investigated. The results of Monte Carlo simulations with the directed-loop algorithm show that the quantum critical behavior is characterized by the mean-field values of critical exponents. The system-size dependence of various quantities is compared to a simple field-theoretical argument that supports the mean-field scaling

Radioisotopic purity and imaging properties of cyclotron-produced 99mTc using direct 100Mo(p,2n) reaction

Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. within 15\u201320 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotrons already available in the nuclear medicine departments of hospitals. The main motivation for such a study is in the framework of the research activities at the international level that have been conducted over the last few years to develop alternative production routes for the most widespread radioisotope used in medical imaging. The analysis of technetium isotopes and isomeric states (9xTc) present in the pertechnetate saline Na99mTcO4 solutions, obtained after the extraction/purification procedure, reveals radionuclidic purity levels basically in compliance with the limits recently issued by European Pharmacopoeia 9.3 (2018 Sodium pertechnetate (99mTc) injection 4801\u20133). Moreover, the impact of 9xTc contaminant nuclides on the final image quality is thoroughly evaluated, analyzing the emitted high-energy gamma rays and their influence on the image quality. The spatial resolution of images from cyclotron-produced 99mTc acquired with a mini-gamma camera was determined and compared with that obtained using technetium-99m solutions eluted from standard 99Mo/99mTc generators. The effect of the increased image background contribution due to Compton-scattered higher-energy gamma rays (E \u3b3 \u2009\u2009>\u2009\u2009200\u2009keV), which could cause image-contrast deterioration, was also studied. It is concluded that, due to the high radionuclidic purity of cyclotron-produced 99mTc using 100Mo(p,2n)99mTc reaction at a proton beam energy in the range 15.7\u201319.4 MeV, the resulting image properties are well comparable with those from the generator-eluted 99mTc

Effective spatial dimension of extremal non-dilatonic black p-branes and the description of entropy on the world volume

By investigating the critical behavior appearing at the extremal limit of the non-dilatonic, black p-branes in (d+p) dimensions, we find that some critical exponents related to the critical point obey the scaling laws. From the scaling laws we obtain that the effective spatial dimension of the non-dilatonic black holes and black strings is one, and is p for the non-dilatonic black p-branes. For the dilatonic black holes and black p-branes, the effective dimension will depend on the parameters in theories. Thus, we give an interpretation why the Bekenstein-Hawking entropy may be given a simple world volume interpretation only for the non-dilatonic black p-branes.Comment: 4 pages, RevTex, no figures, to appear in Phys. Rev. Let

Mechanical properties of materials for 3D printed orthodontic retainers

Aim: The purpose of this study was to compare the mechanical properties of materials used for orthodontic retainers made by direct 3D printing and thermoforming. Materials and methods: Twenty-one specimens (n=7) from 3 different materials (Formlabs Dental LT Clear V2 - Formlabs Inc., Somerville, Massachusetts, USA; NextDent Ortho Flex - Vertex-Dental B.V., Soesterberg, The Netherlands, and Erkodent Erkodur - ERKODENT, Germany) were manufactured and their mechanical properties were evaluated. Two of the specimen groups were 3D printed and the other one was fabricated using a material for thermoforming. The statistical methods we applied were descriptive statistics, the Kruskal-Wallis and Dunn’s post-hoc tests. Results: With respect to Young’s modulus (E), the Kruskal-Wallis test (df=2, χ2=17.121, p=0.0002) showed a significant difference between the materials for direct 3D printing of orthodontic retainers (E=2762.4 MPa±115.16 MPa for group 1 and 2393.05 MPa±158.13 MPa for group 2) and thermoforming foils (group 3, E=1939.4 MPa±74.18 MPa). Statistically significant differences were also found between the flexural strength (FS) (Kruskal-Wallis test, df=2, χ2=17.818, p=0.0001) and F(max) (Kruskal-Wallis test, df=2, χ2=17.818, p=0.0001). Conclusions: The materials tested in the current study showed statistically significant differences in their Young’s modulus, flexural strength, and F(max)

Critical Properties of Condensation of Field-Induced Triplet Quasiparticles

A review on the field-induced magnetic ordering is given, together with some results of a quantum Monte Carlo simulation focused on the critical behevior near the quantum critical point.Comment: Proceedings of SPQS, Sendai, 200

Critical behavior in 2+1 dimensional black holes

The critical behavior and phase transition in the 2+1 dimensional Ba\~nados, Teitelboim, and Zanelli (BTZ) black holes are discussed. By calculating the equilibrium thermodynamic fluctuations in the microcanonical ensemble, canonical ensemble, and grand canonical ensemble, respectively, we find that the extremal spinning BTZ black hole is a critical point, some critical exponents satisfy the scaling laws of the ``first kind'', and the scaling laws related to the correlation length suggest that the effective spatial dimension of extremal black holes is one, which is in agreement with the argument that the extremal black holes are the Bogomol'nyi saturated string states. In addition, we find that the massless BTZ black hole is a critical point of spinless BTZ black holes.Comment: RevTex, 9 pages, nofigur

INDCOR white paper on the Design of Complexity IDNs

This white paper was written by the members of the Work Group focusing on design practices of the COST Action 18230 - Interactive Narrative Design for Complexity Representation (INDCOR, WG1). It presents an overview of Interactive Digital Narratives (IDNs) design for complexity representations through IDN workflows and methodologies, IDN authoring tools and applications. It provides definitions of the central elements of the IDN alongside its best practices, designs and methods. Finally, it describes complexity as a feature of IDN, with related examples. In summary, this white paper serves as an orienting map for the field of IDN design, understanding where we are in the contemporary panorama while charting the grounds of their promising futures