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The collaboration of Yale, the University of California, Davis, and United Imaging Healthcare has successfully developed the NeuroEXPLORER, a dedicated human brain PET imager with high spatial resolution, high sensitivity, and a built-in 3-dimensional camera for markerless continuous motion tracking. It has high depth-of-interaction and time-of-flight resolutions, along with a 52.4-cm transverse field of view (FOV) and an extended axial FOV (49.5 cm) to enhance sensitivity. Here, we present the physical characterization, performance evaluation, and first human images of the NeuroEXPLORER. Methods: Measurements of spatial resolution, sensitivity, count rate performance, energy and timing resolution, and image quality were performed adhering to the National Electrical Manufacturers Association (NEMA) NU 2-2018 standard. The systems performance was demonstrated through imaging studies of the Hoffman 3-dimensional brain phantom and the mini-Derenzo phantom. Initial 18F-FDG images from a healthy volunteer are presented. Results: With filtered backprojection reconstruction, the radial and tangential spatial resolutions (full width at half maximum) averaged 1.64, 2.06, and 2.51 mm, with axial resolutions of 2.73, 2.89, and 2.93 mm for radial offsets of 1, 10, and 20 cm, respectively. The average time-of-flight resolution was 236 ps, and the energy resolution was 10.5%. NEMA sensitivities were 46.0 and 47.6 kcps/MBq at the center and 10-cm offset, respectively. A sensitivity of 11.8% was achieved at the FOV center. The peak noise-equivalent count rate was 1.31 Mcps at 58.0 kBq/mL, and the scatter fraction at 5.3 kBq/mL was 36.5%. The maximum count rate error at the peak noise-equivalent count rate was less than 5%. At 3 iterations, the NEMA image-quality contrast recovery coefficients varied from 74.5% (10-mm sphere) to 92.6% (37-mm sphere), and background variability ranged from 3.1% to 1.4% at a contrast of 4.0:1. An example human brain 18F-FDG image exhibited very high resolution, capturing intricate details in the cortex and subcortical structures. Conclusion: The NeuroEXPLORER offers high sensitivity and high spatial resolution. With its long axial length, it also enables high-quality spinal cord imaging and image-derived input functions from the carotid arteries. These performance enhancements will substantially broaden the range of human brain PET paradigms, protocols, and thereby clinical research applications.

Abstract Background The application of semi-conductor detectors such as cadmium–zinc–telluride (CZT) in nuclear medicine improves extrinsic energy resolution and count sensitivity due to the direct conversion of gamma photons into electric signals. A 3D-ring pixelated CZT system named StarGuide was recently developed and implemented by GE HealthCare for SPECT acquisition. The system consists of 12 detector columns with seven modules of 16 × 16 CZT pixelated crystals, each with an integrated parallel-hole tungsten collimator. The axial coverage is 27.5 cm. The detector thickness is 7.25 mm, which allows acquisitions in the energy range [40–279] keV. Since there is currently no performance characterization specific to 3D-ring CZT SPECT systems, the National Electrical Manufacturers Association (NEMA) NU 1-2018 clinical standard can be tailored to these cameras. The aim of this study was to evaluate the performance of the SPECT/CT StarGuide system according to the NEMA NU 1-2018 clinical standard specifically adapted to characterize the new 3D-ring CZT. Results Due to the integrated collimator, the system geometry and the pixelated nature of the detector, some NEMA tests have been adapted to the features of the system. The extrinsic measured energy resolution was about 5–6% for the tested isotopes (99mTc, 123I and 57Co); the maximum count rate was 760 kcps and the observed count rate at 20% loss was 917 kcps. The system spatial resolution in air extrapolated at 10 cm with 99mTc was 7.2 mm, while the SPECT spatial resolutions with scatter were 4.2, 3.7 and 3.6 mm in a central, radial and tangential direction respectively. Single head sensitivity value for 99mTc was 97 cps/MBq; with 12 detector columns, the system volumetric sensitivity reached 520 kcps MBq−1 cc−1. Conclusions The performance tests of the StarGuide can be performed according to the NEMA NU 1-2018 standard with some adaptations. The system has shown promising results, particularly in terms of energy resolution, spatial resolution and volumetric sensitivity, potentially leading to higher quality clinical images.

Background: The application of semi-conductor detectors such as cadmium–zinc–telluride (CZT) in nuclear medicine improves extrinsic energy resolution and count sensitivity due to the direct conversion of gamma photons into electric signals. A 3D-ring pixelated CZT system named StarGuide was recently developed and implemented by GE HealthCare for SPECT acquisition. The system consists of 12 detector columns with seven modules of 16 × 16 CZT pixelated crystals, each with an integrated parallel-hole tungsten collimator. The axial coverage is 27.5 cm. The detector thickness is 7.25 mm, which allows acquisitions in the energy range [40–279] keV. Since there is currently no performance characterization specific to 3D-ring CZT SPECT systems, the National Electrical Manufacturers Association (NEMA) NU 1-2018 clinical standard can be tailored to these cameras. The aim of this study was to evaluate the performance of the SPECT/CT StarGuide system according to the NEMA NU 1-2018 clinical standard specifically adapted to characterize the new 3D-ring CZT. Results: Due to the integrated collimator, the system geometry and the pixelated nature of the detector, some NEMA tests have been adapted to the features of the system. The extrinsic measured energy resolution was about 5–6% for the tested isotopes (99mTc, 123I and 57Co); the maximum count rate was 760 kcps and the observed count rate at 20% loss was 917 kcps. The system spatial resolution in air extrapolated at 10 cm with 99mTc was 7.2 mm, while the SPECT spatial resolutions with scatter were 4.2, 3.7 and 3.6 mm in a central, radial and tangential direction respectively. Single head sensitivity value for 99mTc was 97 cps/MBq; with 12 detector columns, the system volumetric sensitivity reached 520 kcps MBq−1 cc−1. Conclusions: The performance tests of the StarGuide can be performed according to the NEMA NU 1-2018 standard with some adaptations. The system has shown promising results, particularly in terms of energy resolution, spatial resolution and volumetric sensitivity, potentially leading to higher quality clinical images. [ABSTRACT FROM AUTHOR]

In positron emission tomography (PET), the scattered photons represent a major image degrading factor. The scatter fraction (SF) of PET scanners is experimentally determined following the National Electrical Manufacturers Association (NEMA) NU 2 protocol, using a polyethylene phantom with a line source inserted at 45 mm radial offset from the phantom's center. In this work, we aim to investigate the optimal radial offset of the line source, that represents the SF of a uniformly activated phantom, for the lutetium yttrium orthosilicate (LYSO)-based uEXPLORER total body PET scanner. Additionally, we propose to study the impact of several factors (axial field-of-view (AFOV), crystal material and heterogeneities) on this optimal offset, in an effort to provide recommendations for a wide range of PET scanner configurations. We performed Monte Carlo (MC) simulations of the uEXPLORER scanner along with five phantoms of different diameters, using the Geant4 Application for Tomographic Emission (GATE) code. We performed supplemental MC simulations in which we varied the crystal material, the AFOV and we introduced bone and lung heterogeneities in the phantoms to assess their impact on the optimal offset findings. Our results demonstrated that the 45 mm offset overestimates the SF of the uniform 20 cm diameter phantom by 24.3 . Instead, an offset of 87 mm was reproducing this SF. For the phantoms having diameters in the range of 10–50 cm, an offset of 90.7 of the phantom's radius was shown to be optimal (best fit). No AFOV-related impact has been observed on this optimal offset. The influence of the heterogeneities was also small with less than 1.1 absolute deviation in the SF. This offset could then be used for all AFOV lengths PET scanners using LYSO crystal. The impact of the crystal material was shown to be minimal and an offset of 91.5 of the phantom's radius is consequently recommended as an average for other PET scanners. [ABSTRACT FROM AUTHOR]

Introduction: PET/CT and PET/MRI are valuable multimodality imaging techniques for visualizing both functional and anatomical information. The most used PET reconstruction algorithm is Ordered Subset Expectation Maximization (OSEM). In OSEM, the image noise increases with increased number of iterations, and the reconstruction needs to be stopped before complete convergence. The Bayesian penalized likelihood (BPL) algorithm, recently introduced, uses a noise penalty factor (β) to achieve full convergence while controlling noise. This study aims to evaluate how reconstruction algorithms and lesion radioactivity levels affect PET image quality and quantitative accuracy across three different PET systems. Materials and Methods: A NEMA phantom was filled with 18F and scanned by one PET/MRI and two PET/CT systems with sphere-to-background concentration ratio (SBR) of 2:1, 4:1, or 10:1. PET images were reconstructed with OSEM or BPL with TOF. The number of iterations and β-values were varied, while the matrix size, number of subsets, and filter size remained constant. Contrast recovery (CR) and background variability (BV) were measured in images. Results: CR increased with increased sphere size and SBR. CR and BV decreased with increased β for the 10mm sphere. Increased number of iterations in OSEM showed increased BV with limited variation in CR. BPL gave higher CR and lower BV values than OSEM. The optimal reconstruction was BPL with β between 150 and 350, where BPL was available, and OSEM with two iterations and 21 subsets for the PET/CT without BPL. Conclusion: BPL outperforms OSEM, and SBR significantly influences tracer uptake quantification in small lesions. Future studies should explore the clinical implications of these findings on diagnosis, staging, prognosis, and treatment follow-up.

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Abstract Background We propose a comprehensive evaluation of a Discovery MI 4-ring (DMI) model, using a Monte Carlo simulator (GATE) and a clinical reconstruction software package (PET toolbox). The following performance characteristics were compared with actual measurements according to NEMA NU 2-2018 guidelines: system sensitivity, count losses and scatter fraction (SF), coincidence time resolution (CTR), spatial resolution (SR), and image quality (IQ). For SR and IQ tests, reconstruction of time-of-flight (TOF) simulated data was performed using the manufacturer’s reconstruction software. Results Simulated prompt, random, true, scatter and noise equivalent count rates closely matched the experimental rates with maximum relative differences of 1.6%, 5.3%, 7.8%, 6.6%, and 16.5%, respectively, in a clinical range of less than 10 kBq/mL. A 3.6% maximum relative difference was found between experimental and simulated sensitivities. The simulated spatial resolution was better than the experimental one. Simulated image quality metrics were relatively close to the experimental results. Conclusions The current model is able to reproduce the behaviour of the DMI count rates in the clinical range and generate clinical-like images with a reasonable match in terms of contrast and noise.

Aim The objective of this study includes the NEMA (National Electrical Manufacturer Association) NU2–2018 performance evaluation of the uMIvista PET-CT (positron emission tomography-computed tomography) system. Methods The latest NEMA NU2–2018 guidelines have been followed for the evaluation of performance parameters of this PET-CT scanner: axial, tangential, and radial spatial resolution, sensitivity, counting losses, scatter, randomness, random and counting loss correction, image quality, time and energy resolution, image uniformity, and image registration alignment post installation of country first uMIvista PET-CT. Results The measured NEMA sensitivity of the uMIvista PET scanner was 12.053 cps/kBq. The spatial resolutions of the PET were measured as tangential, radial, and transaxial spatial resolutions at 10 mm, with 3.01 mm, 2.95 mm, and 2.93 mm, respectively; at 100 mm, with 3.17 mm, 3.42 mm, and 3.05 mm, respectively; and at 200 mm, with 3.65 mm, 4.54 mm, and 3.17 mm, respectively, at full-width half-maximum (FWHM); while at full-width tenths-maximum (FWTM), the values at 10 mm were 5.79 mm, 5.57 mm, and 5.69 mm, respectively, and at 100 mm were 5.59 mm, 5.96 mm, and 5.91 mm, respectively. The measured time-of-flight (TOF) timing resolution was 302.294 ps and the measured energy resolution was 11.76% with FWHM and FWTM. Conclusion The NEMA NU2–2018 performances of this TOF-integrated digital PET-CT system are extremely good in all parameters. [ABSTRACT FROM AUTHOR]

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Laskarev’s seminal contribution to the recognition and elucidation of the Paratethys Sea within geological discourse stands as one of the pivotal milestones in our understanding of Neogene European paleogeography. Although the Neogene marine deposits of central and southeastern Europe were known before him, he greatly facilitated discourse and communication about them by giving them a paleogeographical name. By officially introducing the term Paratethys and meticulously delineating its geographic extent and history, Laskarev unveiled profound insights into past climates, environments, and biotic evolution across Central and Eastern Europe. His work provided a solid foundation for subsequent investigations of the Paratethys region. Moreover, beyond its scientific intrigue, the Paratethys Sea holds considerable economic importance due to its rich geo logical endowment. This reservoir of resources includes hydrocarbon reserves, mineral deposits, and a burgeoning potential for geotourism. While substantial strides have been made in unraveling its mysteries, the Paratethys Sea still beckons further exploration, promising untapped realms of knowledge and economic opportunity.

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Background: The limited axial field‐of‐view (FOV) of conventional clinical positron emission tomography (PET) scanners (∼15 to 26 cm) allows detecting only 1% of all coincidence photons, hence limiting significantly their sensitivity. To overcome this limitation, the EXPLORER consortium developed the world's first total‐body PET/CT scanner that significantly increased the sensitivity, thus enabling to decrease the scan duration or injected dose. Purpose: The purpose of this study is to perform and validate Monte Carlo simulations of the uEXPLORER PET scanner, which can be used to devise novel conceptual designs and geometrical configurations through obtaining features that are difficult to obtain experimentally. Methods: The total‐body uEXPLORER PET scanner was modeled using GATE Monte Carlo (MC) platform. The model was validated through comparison with experimental measurements of various performance parameters, including spatial resolution, sensitivity, count rate performance, and image quality, according to NEMA‐NU2 2018 standards. Furthermore, the effects of the time coincidence window and maximum ring difference on the count rate and noise equivalent count rate (NECR) were evaluated. Results: Overall, the validation study showed that there was a good agreement between the simulation and experimental results. The differences between the simulated and experimental total sensitivity for the NEMA and extended phantoms at the center of the FOV were 2.3% and 0.0%, respectively. The difference in peak NECR was 9.9% for the NEMA phantom and 1.0% for the extended phantom. The average bias between the simulated and experimental results of the full‐width‐at‐half maximum (FWHM) for six different positions and three directions was 0.12 mm. The simulations showed that using a variable coincidence time window based on the maximum ring difference can reduce the effect of random coincidences and improve the NECR compared to a constant time coincidence window. The NECR corresponding to 252‐ring difference was 2.11 Mcps, which is larger than the NECR corresponding to 336‐ring difference (2.04 Mcps). Conclusion: The developed MC model of the uEXPLORER PET scanner was validated against experimental measurements and can be used for further assessment and design optimization of the scanner. [ABSTRACT FROM AUTHOR]

This corrects the article “Computer-aided approach for the identification of lead molecules as the inhibitors of cholinesterase’s and monoamine oxidases: Novel target for the treatment of Alzheimer disease” published in volume 89, number 2, page 177 (https://doi.org/10.2298/JSC230307050E). CONTENT OF THE CORRECTION For author Ammara Fayyaz, additional affiliation is added. Previous article affiliation was: 1Department of Pharmaceutical Chemistry, Faculty of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan, 2Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia and 3Department of Biochemistry, College of Science, King Saud University, P.O. Box 22452, Riyadh 11451, Saudi Arabia Corrected affiliation is: 1Department of Pharmaceutical Chemistry, Faculty of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan, 2Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud Univeristy, P.O. Box 2457, Riyadh 11451, Saudi Arabia, 3Department of Biochemistry, College of Science, King Saud Univeristy, P.O. Box 22452, Riyadh 11451, Saudi Arabia and 4School of Pharmaceutical Science and Technology, Tianjin University, 30072, Tianjin, China In Acknowledgement, the supporting project number is changed. Previous acknowledgement was: Acknowledgement. The authors extend their appreciation to researchers supporting project number RSP-2023/357, King Saud University, Riyadh, Saudi Arabia, for funding this research. Correct acknowledgement is: Acknowledgement. The authors extend their appreciation to researchers supporting project number RSP2024R357, King Saud University, Riyadh, Saudi Arabia, for funding this research. Link to the corrected article 10.2298/JSC230307050E

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Motivation: There is scant information on support systems for internally displaced persons in Nigeria, and none on internally displaced women in the New Kuchingoro camp. This limits the operations of aid agencies and other stakeholders, preventing them from providing targeted assistance. Purpose: First, it examined the support provided by two government agencies: the National Commission for Refugees, Migrants and Internally Displaced Persons (NCFRMI) and the National Emergency Management Agency (NEMA). Second, it investigated and examined the support given by non‐governmental organizations, religious organizations, and philanthropists. Third, it analysed the challenges facing these bodies, drew conclusions about the policy implications of the situation in New Kuchingoro, and made recommendations for changes that would improve the lives of internally displaced women in the camp. Methods and approach: Using qualitative research methods, the study investigated and evaluated the various support systems provided by NCFRMI and NEMA to internally displaced women in the New Kuchingoro camp in Abuja, along with some NGOs, religious groups, and philanthropists. Findings: The study revealed the inadequacy of co‐ordination between government agencies and NGOs in the provision of humanitarian assistance to the New Kuchingoro camp. While these NGOs were willing to provide humanitarian assistance to the women, the lack of administrative support from NCFRMI and NEMA frustrated this objective. Policy implications: The government needs to clarify the respective roles of NCFRMI and NEMA with regard to IDPs and relationships with non‐government aid providers, ensure adequate funding for IDPs, stamp out corruption, respect the humanitarian principles of impartiality and neutrality, and ultimately address the underlying causes of displacement. [ABSTRACT FROM AUTHOR]

The aim of this study was to conduct a technical and clinical evaluation of a Silicon Photomultiplier (SiPM) integrated digital Positron Emission Tomography – Computed Tomography (PETCT) Scanner using National Electrical Manufacturers Association (NEMA) NU 2- 2018 standards. System sensitivity was measured by using a NEMA sensitivity phantom. Scatter fraction, count-rate performance, accuracy of count loss, and timing resolution were all computed. Clinical images were acquired and image quality was assessed and compared with published studies. At 1 cm, tangential, radial, and axial spatial resolutions were 3.02 mm, 3.02 mm, and 2.73 mm at full width half maximum (FWHM), respectively. Sensitivity at centre and 10 cm was 10.359 cps/kBq and 9.741 cps/kBq, respectively. The timing resolution was measured at 372 ps. The digital PETCT exhibits a high-spatial resolution and a superior timing resolution, which advances the diagnostic ability to detect small lesions and boosts the diagnostic confidence. Increases clinical relevance by improving the ability to detect and differentiate tiny or low-contrast lesions without compromising radiopharmaceutical dose or overall scan time. [ABSTRACT FROM AUTHOR]

This article strives for a combined approach consisting of historical geography and art and church history in the research of Duklja and Raška in the times of Stefan Nemanja. The article’s first part addresses the circumstances of the birth of Stefan Nemanja and the question of Nemanja’s two baptisms. Moreover, data on the churches and monasteries, their patrocinia and the stećci (funeral monuments) in the area of research has been gathered and then analysed with digital tools to offer a map-based reconstruction of the “Sacred Landscape”.

In this study, the development of non-homogeneous color changes in oak timber during conventional drying and their relationship with the moisture gradient across the wood thickness were analyzed. The research was conducted on radial and tangential boards with a thickness of 38 mm, cut from two oak logs, one of sessile oak (Quercus petraea L.) and one of pedunculate oak (Quercus robur L.). A conventional drying schedule commonly used in enterprises was applied, and at specified time intervals samples were taken to determine the moisture content profile and monitor color changes on the cross sections of the samples. The findings reveal a complex relationship between the wood moisture content, the moisture content profile across the thickness, and the occurrence of color changes. Additionally, it was found that the wood of sessile oak dries slower and with less intense color changes compared to the wood of pedunculate oak. It was demonstrated that quarter-sawn boards dry slower compared to flat-sawn boards for both wood species. No differences in the appearance of non-homogeneous color between quarter-sawn and flat-sawn boards were identified.

The Central Balkan region offers particular insights into the very last episodes of the life of oceanic domains that existed between Adria and Europe. This special issue highlights some of the latest developments in the geological research of this important area with a rather small but eclectic selection of papers aimed at better understanding of the geodynamics of the long-lasting Adria - Europe convergence. The road ahead involves more detailed investigations and key studies, including sedimentology, geochronology, provenance and microtectonics, to further enhance our knowledge about the issues that are opened or discussed in this volume.

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Abstract Background This study evaluated the physical performance of a positron emission tomography (PET) system dedicated to the head and breast according to the National Electrical Manufacturers Association (NEMA) NU2-2012 standard. Methods The spatial resolution, sensitivity, scatter fraction, count rate characteristics, corrections for count losses and randoms, and image quality of the system were determined. All measurements were performed according to the NEMA NU2-2012 acquisition protocols, but image quality was assessed using a brain-sized phantom. Furthermore, scans of the three-dimensional (3D) Hoffmann brain phantom and mini-Derenzo phantom were acquired to allow visual evaluation of the imaging performance for small structures. Results The tangential, radial, and axial full width at half maximum (FWHM) at a 10-mm offset in half the axial field of view were measured as 2.3, 2.5, and 2.9 mm, respectively. The average system sensitivity at the center of the field of view and at a 10-cm radial offset was 7.18 and 8.65 cps/kBq, respectively. The peak noise-equivalent counting rate was 35.2 kcps at 4.8 kBq/ml. The corresponding scatter fraction at the peak noise-equivalent counting rate was 46.8%. The peak true rate and scatter fraction at 8.6 kBq/ml were 127.8 kcps and 54.3%, respectively. The percent contrast value for a 10-mm sphere was approximately 50%. On the 3D Hoffman brain phantom image, the structures of the thin layers composing the phantom were visualized on the sagittal and coronal images. On the mini-Derenzo phantom, each of the 1.6-mm rods was clearly visualized. Conclusion Taken together, these results indicate that the head- and breast-dedicated PET system has high resolution and is well suited for clinical PET imaging.

CORRECTION TO THE PAPER GASIMLI, V., HUSEYN, R, & HUSEYNOV, R. (2024) Some terminological inaccuracies have been identified in the article “Economywide and environmental benefits of green energy development in oil-rich countries: Evidence from Azerbaijan’ published Economic Annals, 2024 69(241):41-64. https://doi.org/10.2298/EKA2441041G. The sentence on page 42 “It is attempting to implement a mega project that involves laying a pipeline under the Black Sea to export renewable energy to Europe after using it for oil and natural gas” corrected as below: “It is attempting to implement a mega project that involves laying a cable under the Black Sea to export renewable energy to Europe”. Link to the corrected article 10.2298/EKA2441041G

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Purpose: The image quality characteristics of two NEMA phantoms with yttrium-90 (90Y) were evaluated on a long axial field-of-view (AFOV) PET/CT. The purpose was to identify the optimized reconstruction setup for the imaging of patients with hepatocellular carcinoma after 90Y radioembolization. Methods: Two NEMA phantoms were used, where one had a 1:10 sphere to background activity concentration ratio and the second had cold background. Reconstruction parameters used are as follows: iterations 2 to 8, Gaussian filter 2- to 6-mm full-width-at-half-maximum, reconstruction matrices 440 × 440 and 220 × 220, high sensitivity (HS), and ultra-high sensitivity (UHS) modes. 50-, 40-, 30-, 20-, 10-, and 5-min acquisitions were reconstructed. The measurements included recovery coefficients (RC), signal-to-noise ratio (SNR), background variability, and lung error which measures the residual error in the corrections. Patient data were reconstructed with 20-, 10-, 5-, and 1-min time frames and evaluated in terms of SNR. Results: The RC for the hot phantom was 0.36, 0.45, 0.53, 0.63, 0.68, and 0.84 for the spheres with diameters of 10, 13, 17, 22, 28, and 37 mm, respectively, for UHS 2 iterations, a 220 × 220 matrix, and 50-min acquisition. The RC values did not differ with acquisition times down to 20 min. The SNR was the highest for 2 iterations, measured 11.7, 16.6, 17.6, 19.4, 21.9, and 27.7 while the background variability was the lowest (27.59, 27.08, 27.36, 26.44, 30.11, and 33.51%). The lung error was 18%. For the patient dataset, the SNR was 19%, 20%, 24%, and 31% higher for 2 iterations compared to 4 iterations for 20-, 10-, 5-, and 1-min time frames, respectively. Conclusions: This study evaluates the NEMA image quality of a long AFOV PET/CT scanner with 90Y. It provides high RC for the smallest sphere compared to other standard AFOV scanners at shorter scan times. The maximum patient SNR was for 2 iterations, 20 min, while 5 min delivers images with acceptable SNR. [ABSTRACT FROM AUTHOR]

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The blood-brain barrier (BBB) is formed by continuous, closely connected endothelial cells, enveloped in the basal lamina, pericytes, and foot extensions of astrocytes. BBB has a vital role in brain metabolism and protects the brain parenchyma from harmful agents present in the systemic circulation. Damage to the BBB and an increase in its permeability have an important role in many neurodegenerative diseases. This paper aims to review the literature on the impact of the BBB damage on psychiatric illness, a largely neglected and under researched area. Links between BBB impairment and specific neuropsychiatric disorders are described including schizophrenia, affective disorders, dementias with behavioral disorders, and alcohol use disorder, with comparison to typical hereditary small vessel diseases affecting the BBB such as cerebral autosomal dominant arteriopathy with subcortical infarction and leukoencephalopathy (CADASIL) and mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS). The authors critically summarize possible pathogenic mechanisms linking BBB damage and these common disorders.

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As a result of advances in science and technology, the importance of metal matrix composite materials is increasing gradually today. However, in many studies, composite production is carried out with monotype ceramic particle reinforcement. In this study, the production, microstructure-hardness, and wear performance of composite-hybrid materials that had AA 7075 aluminum powder metal matrix and were reinforced by SiC and Al2O3 ceramic particles at different ratios were examined. The prepared Matrix and reinforcement powder mixtures were mixed for half an hour in the three-axis Turbula T2F type mixer and then, pressed unidirectionally and cylindrically under the pressure of 700 MPa. The pressed samples were sintered for 1 h at a temperature of 600oC in the argon atmosphere. Microstructure examinations were carried out using SEM (Scanning Electron Microscope) and optical microscope devices, while hardness measurements were obtained as a result of Brinell measurement. Wear performance of the test samples were tested in the Pin-on-disk type device at 10 N load and 500 rpm rotation speed by depending on the wear distances at 1000, 1500 and 2000 m. It was observed that hardness increased as the amount of ceramic particle in composite-hybrid samples increased. As a result of wear tests, in hybrid composites, compared to single-phase ceramic particle reinforced composites, weight losses increased depending on the increase in the reinforcement amount.

The author of the article "Optimality Conditions and Duality for Multiobjective Semi-Infinite Programming with Data Uncertainity via Mordukhovich Subdifferential", Thanh-Hung Pham has informed the Editor about necessary corrections of the paper. Link to the corrected article 10.2298/YJOR201017013P

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Background: This study evaluated the physical performance of a positron emission tomography (PET) system dedicated to the head and breast according to the National Electrical Manufacturers Association (NEMA) NU2-2012 standard. Methods: The spatial resolution, sensitivity, scatter fraction, count rate characteristics, corrections for count losses and randoms, and image quality of the system were determined. All measurements were performed according to the NEMA NU2-2012 acquisition protocols, but image quality was assessed using a brain-sized phantom. Furthermore, scans of the three-dimensional (3D) Hoffmann brain phantom and mini-Derenzo phantom were acquired to allow visual evaluation of the imaging performance for small structures. Results: The tangential, radial, and axial full width at half maximum (FWHM) at a 10-mm offset in half the axial field of view were measured as 2.3, 2.5, and 2.9 mm, respectively. The average system sensitivity at the center of the field of view and at a 10-cm radial offset was 7.18 and 8.65 cps/kBq, respectively. The peak noise-equivalent counting rate was 35.2 kcps at 4.8 kBq/ml. The corresponding scatter fraction at the peak noise-equivalent counting rate was 46.8%. The peak true rate and scatter fraction at 8.6 kBq/ml were 127.8 kcps and 54.3%, respectively. The percent contrast value for a 10-mm sphere was approximately 50%. On the 3D Hoffman brain phantom image, the structures of the thin layers composing the phantom were visualized on the sagittal and coronal images. On the mini-Derenzo phantom, each of the 1.6-mm rods was clearly visualized. Conclusion: Taken together, these results indicate that the head- and breast-dedicated PET system has high resolution and is well suited for clinical PET imaging. [ABSTRACT FROM AUTHOR]

The uMI Panorama GS PET/CT system is a new long-axial-field-of-view scanner featuring high sensitivity, time-of-flight (TOF) resolution, spatial resolution, and count rate performance. The aim of this study is to assess the PET system on the basis of the National Electrical Manufacturers Association (NEMA) NU 2-2018 and European Association of Nuclear Medicine Research Limited (EARL) standards. Methods: Spatial resolution, count rate performance, sensitivity, accuracy, image quality, TOF resolution, and coregistration accuracy were evaluated following the NEMA NU 2-2018 standard. Additional experiments included energy resolution, 200-cm-long line sources for sensitivity, a 175-cm-long scatter phantom for count rate and TOF resolution, as well as the compliance with the EARL guideline. Moreover, an 18 F-FDG PET patient study was reconstructed with various frame durations. Results: The PET system achieved sub-3-mm transaxial and axial spatial resolutions at a 1-cm radial offset. The sensitivities with the 70-cm-long and 200-cm-long line sources were observed to be 176.3 and 90.8 kcps/MBq, respectively, at the center of the field of view. The noise-equivalent count rates (NECRs) of the 70-cm-long and 175-cm-long scatter phantoms were measured to be 3.35 Mcps at 57.57 kBq/mL and 2.24 Mcps at 33.27 kBq/mL, respectively. The TOF resolutions for both phantoms were approximately 189 ps at 5.3 kBq/mL and lower than 200 ps below the NECR peaks. The absolute count rate errors of all 34 acquisitions were less than 3% below the NECR peak for the 70-cm-long scatter phantom. With the standard NEMA image quality phantom experiment, the contrast recovery coefficient varied from 68.17% to 94.20% and the background variabilities were all below 2%. The maximum PET/CT coregistration error was 1.33 mm. Regarding EARL compliance, the gaussian filter of 5-mm full width at half maximum could produce acceptable images. The patient data demonstrate visually satisfactory image quality with short frames (less than 1 min). Conclusion: The uMI Panorama GS exhibits spatial resolution and TOF resolution similar to those of the uMI Panorama system (35-cm axial field of view), despite the extended axial field of view. The 148-cm axial coverage, sub-200-ps TOF resolution, high sensitivity, and count rate performances are expected to yield superior image quality and offer new opportunities for various clinical applications., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

Abstract Background This study aimed to evaluate the performance of a preclinical PET insert in three configurations: as a stand-alone unit outside the MRI bore, inside the bore of a cryogen-free 3T MRI and, finally, while performing simultaneous PET/MRI studies. Methods The PET insert consists of two rings of six detectors, each detector comprising 8 × 12 SiPMs reading out dual offset layers of pixelated LYSO crystals with a 1.4-mm pitch. The inner diameter is 60 mm, transaxial field of view (FoV) 40 mm and axial FoV 98 mm. Evaluation was based on NEMA NU 4-2008 guidelines with appropriate modifications. Spatial resolution and sensitivity were measured inside and outside the MR bore. Image quality, count rate and quantitative performance were measured in all three configurations. The effect of temperature stability on PET sensitivity during fast spin echo sequences was also evaluated. B0 field homogeneity and T1 and T2 relaxation times were measured using a water-filled phantom, with and without simultaneous PET operation. Finally, PET and MRI scans of a mouse injected with 10 MBq [18F]NaF and a mouse injected with 16 MBq [18F]FDG were performed in sequential and simultaneous modes. Results Peak absolute sensitivity was 10.15% with an energy window of 250–750 keV. Absolute sensitivity values outside and inside the MR bore with MR idle agreed to within 0.1%. Outside the MR bore, spatial resolution was 1.21/1.59 mm FWHM (radial/tangential) 5 mm from the centre of the FoV which compared well with 1.19/1.26 mm FWHM inside the MR bore. There were no substantial differences between all three scan configurations in terms of peak NEC rate (175 kcps at 17 MBq), scatter or random fractions. Uniformity and recovery coefficients were also consistent between scanning modes. B0 field homogeneity and T1 and T2 relaxation times were unaltered by the presence of the PET insert. No significant differences were observed between sequential and simultaneous scans of the animals. Conclusions We conclude that the performance of the PET insert and MRI system is not significantly affected by the scanning mode.

In a breakthrough, Hastings showed that there exist quantum channels whose classical Holevo capacity is superadditive i.e. more classical information can be transmitted by quantum encoding strategies entangled across multiple channel uses as compared to unentangled quantum encoding strategies. Hastings’ proof used Haar random unitaries to exhibit superadditivity. In this paper we show that a unitary chosen uniformly at random from an approximate $n^{2/3}$ -design gives rise to a quantum channel with superadditive classical Holevo capacity, where $n$ is the dimension of the unitary exhibiting the Stinespring dilation of the channel superoperator. We follow the geometric functional analytic approach of Aubrun, Szarek and Werner in order to prove our result. More precisely we prove a sharp Dvoretzky-like theorem stating that, with high probability under the choice of a unitary from an approximate $t$ -design, random subspaces of large dimension make a Lipschitz function take almost constant value. Such theorems were known earlier only for Haar random unitaries. We obtain our result by appealing to Low’s technique for proving concentration of measure for an approximate $t$ -design, combined with a stratified analysis of the variational behaviour of Lipschitz functions on the unit sphere in high dimension. The stratified analysis is the main technical advance of this work. Haar random unitaries require at least $\Omega (n^{2})$ random bits in order to describe them with good precision. In contrast, there exist exact $n^{2/3}$ -designs using only $O(n^{2/3} \log n)$ random bits. Thus, our work can be viewed as a partial derandomisation of Hastings’ result, and a step towards the quest of finding an explicit quantum channel with superadditive classical Holevo capacity. Finally we also show that for any $p > 1$ , approximate unitary $n^{1.7}$ -designs give rise to channels violating subadditivity of Rényi $p$ -entropy. In addition to stratified analysis, the proof of this result uses a new technique of approximating a monotonic differentiable function defined on a closed bounded interval and its derivative by moderate degree polynomials which should be of independent interest. [ABSTRACT FROM AUTHOR]

One of the applications of Sparse Linear Wireless Sensor Networks is environmental monitoring. In these networks, sensors are deployed in sensitive and strategic areas, such as highways and streets, to collect environmental data. Due to the long-term monitoring of the environment by the sensors and the lack of replacement of the energy source of the sensors, network lifetime is significantly reduced. Therefore, this paper presents the New Environment Monitoring Approach using Sparse Linear Wireless Sensor Networks (NEMA) for monitoring the environment using Dual Sinks. In the proposed NEMA method, static sensor nodes are scattered and equidistant from each other and monitor the environment. Due to being less, the number of sensor nodes relative to the area covered, data communication, and correlation are reduced. Therefore, the sensor nodes send the received packets to the destination without performing any data aggregation process. The proposed method was simulated in Simulator version 2 (NS-2). According to the criteria of average energy consumption, maximum waiting time, probability of sending data packets to the mobile sink node, average data packet delivery delay and network lifetime, the proposed method was compared with Classical approach 1 and Classical approach 2. The results obtained from the simulation data show the superiority of the proposed method over previous methods. [ABSTRACT FROM AUTHOR]

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IEEE recently introduced new revisions to the medium- and high-voltage circuit breaker standards. The revised standards provide for new ratings and capabilities; expand choices for users by making it easier to certify and accept under IEEE/ANSI standards equipment originally destined for the IEC market; and clarify the scope and limitations of various ratings of importance to the industrial user. This article presents some of the more pertinent changes and how these changes affect the application of circuit breakers in the petroleum and chemical industries. [ABSTRACT FROM AUTHOR]