Kinematic magnetic resonance imaging study of the brain stem and cervical cord by dynamic neck motion

Background: The aim was to examine the position of the brain stem and cervical cord following the neck flexion and extension. Materials and methods: The serial sagittal T2-weighted magnetic resonance imaging (MRI) sections of the cervical cord and brain stem were made in 6 volunteers. The images were mainly used to measure certain distances and angles of the brain stem and cervical cord in the neutral position, and then following the head and neck flexion and extension. Results: The measurements showed that the pons is slightly closer to the clivus following the neck flexion; the medulla oblongata is somewhat distant to the basion but closer to the odontoid process. At the same time, the spino-medullary angle diminishes in size. On the other hand, the upper cervical cord slightly approaches the posterior wall of the spinal canal, the lower cervical cord is closer to the anterior wall, while the angle between them is significantly larger in size. After the cervical cord extension, the rostral pons is somewhat distant to the clivus, whereas the caudal pons and the medulla are slightly closer to the clivus and the basion. At the same time, the spino-medullary angle diminishes in size. The cervical cord is mainly closer to the posterior wall of the spinal canal, whilst its angle is significantly smaller. Conclusions: The obtained results regarding the brain stem and cervical cord motion can be useful in the kinetic MRI examination of certain congenital disorders, degenerative diseases, and traumatic injuries of the craniovertebral junction and the cervical spine

Desenvolvimento de um nanocompósito de matriz de polietileno (PEAD) com adição de nanocargas com expansão térmica negativa da família A2M3O12

Com a revolução nanotecnológica surgiu a possibilidade de manipulação dos materiais em níveis submicroscópicos. Três áreas da engenharia de materiais foram correlacionadas no presente trabalho: materiais poliméricos, nanomateriais e materiais cerâmicos com expansão térmica negativa, da reunião dessas áreas estão sendo desenvolvidos os nanocompósitos poliméricos para aplicações especiais, tais como na redução da expansão térmica positiva dos polímeros termoplásticos. Neste trabalho foi desenvolvido um novo nanocompósito com matriz de PEAD e nanocargas da família A2M3O12, especificamente o Al2Mo3O12 sintetizado pelo método de co-preciptação, uma rota de baixas energias térmicas. O processamento do nanocompósito foi realizado em uma micro-extrusora de 2 roscas e o material foi injetado em um molde de corpos de prova de ensaios de tração, com percentuais em peso de nanocargas predefinidos em 0,5%, 1%, 2%, 3%, 4% e 5%. Foram realizadas caracterizações térmicas, com microscópio eletrônico e mecânicas dos corpos de prova, obtendo-se detalhamentos micro-nanoestruturais. Sob o aspecto mecânico o principal objetivo foi estudar e evidenciar uma não redução de propriedades mecânicas e investigar possíveis melhorias, que foram obtidas em seus módulos de elasticidade e limite de resistência mecânica. Comparando o módulo de Young e o limite de resistência do PEAD puro de 1,2 GPa e 26 MPa respectivamente, ficou evidente o aumento destas propriedades mecânicas em 27% e 7%, visto que foram alcançados valores de 1,65 GPa e 28 MPa, para a amostra com 2% em peso. Com isso o nanocompósito mostrou-se promissor com possibilidades de aplicações mecânicas substitucionais em relação aos materiais clássicos de componentes e peças atualmente usados

Supplementary data for the article: Mancic, L.; Djukic-Vukovic, A.; Dinic, I.; Nikolic, M. G.; Rabasovic, M. D.; Krmpot, A. J.; Costa, A. M. L. M.; Marinkovic, B. A.; Mojovic, L.; Milosevic, O. One-Step Synthesis of Amino-Functionalized up-Converting NaYF 4 :Yb,Er Nanoparticles for: In Vitro Cell Imaging. RSC Advances 2018, 8 (48), 27429–27437. https://doi.org/10.1039/c8ra04178d

Supplementary material for: [https://doi.org/10.1039/c8ra04178d]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2225

Generalized oscillator strength for Na 3s-3p transition

Generalized oscillator strengths (GOS's) for the Na $3s -3p$ transition have been investigated using the spin-polarized technique of the random phase approximation with exchange (RPAE) and the first Born approximation (FBA), focussing our attention on the position of the minimum. Intershell correlations are found to influence the position of the minimum significantly, but hardly that of the maximum. The RPAE calculation predicts for the first time the positions of the minimum and maximum at momentum transfer, $K$ values of 1.258 a.u. and 1.61 a.u., respectively. The former value is within the range of values extracted from experimental measurements, $K=1.0-1.67$ a.u.. We recommend careful experimental search for the minimum around the predicted value for confirmation.Comment: 11 pages, 2figure

An automatic framework to create patient-specific eye models from 3D magnetic resonance images for treatment selection in patients with uveal melanoma

Purpose: The optimal treatment strategy for uveal melanoma (UM) relies on many factors, the most important being tumor size and location. Building on recent developments in high-resolution 3D ocular magnetic resonance imaging (MRI), we developed an automatic image-processing framework to create patient-specific eye models and to subsequently determine the full 3D tumor shape and size automatically.Methods and Materials: From 15 patients with UM, 3D inversion-recovery gradient-echo (T1-weighted) and 3D fat-suppressed spin-echo (T2-weighted) images were acquired with a 7T MRI scanner. First, the sclera and cornea were segmented from the T2 weighted image by mesh-fitting. The T1-and T2-weighted images were then coregistered. From the registered T1-weighted image, the lens, vitreous body, retinal detachment, and tumor were segmented. Fuzzy C-means clustering was used to differentiate the tumor from retinal detachments. The tumor model was verified and (if needed) edited by an ophthalmic MRI specialist. Subsequently, the prominence and largest basal diameter of the tumor were measured automatically based on the verified contours. These results were compared with manual assessments on the original images and with ultrasound measurements to show the errors in manual analysis.Results: The framework successfully created an eye model fully automatically in 12 cases. In these cases, a Dice similarity coefficient (mean surface distance) of 97.7%+/- 0.84% (0.17 +/- 0.11 mm) was achieved for the sclera, 96.8%+/- 1.05% (0.20 +/- 0.06 mm) for the vitreous body, 91.6%+/- 4.83% (0.15 +/- 0.06 mm) for the lens, and 86.0%+/- 7.4% (0.35 +/- 0.27 mm) for the tumor. The manual assessments deviated, on average, 0.39 +/- 0.31 mm in prominence and 1.7 +/- 1.22 mm in basal diameter from the automatic measurements.Conclusions: The described framework combined information from T1- and T2-weighted images to accurately determine tumor boundaries in 3D. The proposed process may have a direct effect on clinical workflow, as it enables an accurate 3D assessment of tumor dimensions, which directly influences therapy selection. (C) 2021 Published by Elsevier Inc. on behalf of American Society for Radiation Oncology.Biological, physical and clinical aspects of cancer treatment with ionising radiatio

Life cycle greenhouse gas emissions of blended cement concrete including carbonation and durability

The final publication is available at Springer via http://dx.doi.org/10.1007/s11367-013-0614-0Purpose Blended cements use waste products to replace Portland cement, the main contributor to CO2 emissions in concrete manufacture. Using blended cements reduces the embodied greenhouse gas emissions; however, little attention has been paid to the reduction in CO2 capture (carbonation) and durability. The aim of this study is to determine if the reduction in production emissions of blended cements compensates for the reduced durability and CO2 capture. Methods This study evaluates CO2 emissions and CO2 capture for a reinforced concrete column during its service life and after demolition and reuse as gravel filling material. Concrete depletion, due to carbonation and the unavoidable steel embedded corrosion, is studied, as this process consequently ends the concrete service life. Carbonation deepens progressively during service life and captures CO2 even after demolition due to the greater exposed surface area. In this study, results are presented as a function of cement replaced by fly ash (FA) and blast furnace slag (BFS). Results and discussion Concrete made with Portland cement, FA (35%FA), and BFS blended cements (80%BFS) captures 47, 41, and 20 % of CO2 emissions, respectively. The service life of blended cements with high amounts of cement replacement, like CEM III/A (50 % BFS), CEM III/B (80 % BFS), and CEMII/B-V (35%FA), was about 10%shorter, given the higher carbonation rate coefficient. Compared to Portland cement and despite the reduced CO2 capture and service life, CEM III/B emitted 20 % less CO2 per year. Conclusions To obtain reliable results in a life cycle assessment, it is crucial to consider carbonation during use and after demolition. Replacing Portland cement with FA, instead of BFS, leads to a lower material emission factor, since FA needs less processing after being collected, and transport distances are usually shorter. However, greater reductions were achieved using BFS, since a larger amount of cement can be replaced. Blended cements emit less CO2 per year during the life cycle of a structure, although a high cement replacement reduces the service life notably. If the demolished concrete is crushed and recycled as gravel filling material, carbonation can cut CO2 emissions by half. A case study is presented in this paper demonstrating how the results may be utilized.This research was financially supported by the Spanish Ministry of Science and Innovation (research project BIA2011-23602). The authors thank the anonymous reviewers for their constructive comments and useful suggestions. The authors are also grateful for the thorough revision of the manuscript by Dr. Debra Westall.García Segura, T.; Yepes Piqueras, V.; Alcalá González, J. (2014). Life cycle greenhouse gas emissions of blended cement concrete including carbonation and durability. International Journal of Life Cycle Assessment. 19(1):3-12. https://doi.org/10.1007/s11367-013-0614-0S312191Aïtcin PC (2000) Cements of yesterday and today: concrete of tomorrow. Cem Concr Res 30(9):1349–1359Angst U, Elsener B, Larsen C (2009) Critical chloride content in reinforced concrete—a review. Cement Concr Res 39(12):1122–1138Berge B (2000) The ecology of building materials. Architectural Press, OxfordBertolini L, Elsener B, Pedeferri P, Polder R (2004) Corrosion of Steel in Concrete—Prevention Diagnosis. Repair, Wiley-VCH, WeinheimBörjesson P, Gustavsson L (2000) Greenhouse gas balances in building construction: wood versus concrete from life cycle and forest land-use perspectives. Energy Policy 28(9):575–588Camp CV, Huq F (2013) CO2 and cost optimization of reinforced concrete frames using a big bang-crunch algorithm. Eng Struct 48:363–372CEN (2011) EN 197–1: Cement. Part 1: Composition, specifications and conformity criteria for common cements. European Committee for Standardization, BrusselsCIWMB (2000) Designing with vision: a technical manual for materials choices in sustainable construction. California Integrated Waste Management Board, SacramentoCollins F (2010) Inclusion of carbonation during the life cycle of built and recycled concrete: influence on their carbon footprint. Int J Life Cycle Assess 15(6):549–556Database BEDEC (2012) Institute of Construction Technology of Catalonia. Barcelona, SpainDodoo A, Gustavsson L, Sathre R (2009) Carbon implications of end-of-life management of building materials. Resour Conserv Recy 53(5):276–286ECO-SERVE Network Cluster 3 (2004) Baseline Report for the Aggregate and Concrete Industries in Europe. European Commission, Hellerup: http://www.eco-serve.net/uploads/479998_baseline_report_final.pdf , accessed 10 September 2012European Federation of Concrete Admixtures Associations (2006) Environmental Product Declaration (EPD) for Normal Plasticizing admixtures. Environmental Consultant, Sittard: http://www.efca.info/downloads/324%20ETG%20Plasticiser%20EPD.pdf , accessed 13 October 2012Galán I (2011) Carbonatación del hormigón: combinación de CO2. Dissertation, Universidad Complutense de Madrid, SpainGalán I, Andrade C, Mora P, Sanjuan MA (2010) Sequestration of CO2 by concrete carbonation. Environ Sci Technol 44(8):3181–3186Flower DJM, Sanjayan JG (2007) Greenhouse gas emissions due to concrete manufacture. Int J Life Cycle Assess 12(5):282–288Guzmán S, Gálvez JC, Sancho JM (2011) Cover cracking of reinforced concrete due to rebar corrosion induced by chloride penetration. Cement Concr Res 41(8):893–902Houst YF, Wittmann FH (2002) Depth profiles of carbonates formed during natural carbonation. C Cement Concr Res 32(12):1923–1930Institute for Diversification and Energy Saving (2010) Conversion factors of primary energy and CO2 emissions of 2010. M. Industria, Energía y Turismo, Madrid, Spain: http://www.idae.es/index.php/mod.documentos/mem.descarga?file=/documentos_Factores_Conversion_Energia_y_CO2_2010_0a9cb734.pdf , accessed 10 September 2012ISO (2005) ISO/TC 71—Business plan. Concrete, reinforced concrete and prestressed concrete. International Organization for Standardization (ISO), Geneva, SwitzerlandISO (2006) ISO 14040: Environmental management—life-cycle assessment—principles and framework. International Organization for Standardization, Geneva, SwitzerlandJiang L, Lin B, Cai Y (2000) A model for predicting carbonation of high-volume fly ash concrete. Cement Concr Res 30(5):699–702Jönsson A, Björklund T, Tillman AM (1988) LCA of concrete and steel building frames. Int J Life Cycle Assess 3(4):216–224Knoeri C, Sanyé-Mengual E, Althaus HJ (2013) Comparative LCA of recycled and conventional concrete for structural applications. Int J Life Cycle Assess 18(5):909–918Lagerblad B (2005) Carbon dioxide uptake during concrete life-cycle: State of the art. Swedish Cement and Concrete Research Institute, StockholmLeber I, Blakey FA (1956) Some effects of carbon dioxide on mortars and concrete. J Am Concr Inst 53:295–308Fomento M (2008) EHE-08; Code of Structural Concrete. M. Fomento, Madrid, SpainMarinkovic S, Radonjanin V, Malešev M, Ignjatovic I (2010) Comparative environmental assessment of natural and recycled aggregate concrete. Waste Manag 30(11):2255–2264Martinez-Martin FJ, Gonzalez-Vidosa F, Hospitaler A, Yepes V (2012) Multi-objective optimization design of bridge piers with hybrid heuristic algorithms. J Zhejiang Univ-SCI A 13(6):420–432O’Brien KR, Ménaché J, O’Moore LM (2009) Impact of fly ash content and fly ash transportation distance on embodied greenhouse gas emissions and water consumption in concrete. Int J Life-cycle Assess 14(7):621–629Pade C, Guimaraes M (2007) The CO2 uptake of concrete in a 100-year perspective. Cem Concr Res 37(9):1384–1356Papadakis VG, Vayenas CG, Fardis MN (1991) Fundamental modeling and experimental investigation of concrete carbonation. ACI Mater J 88(4):363–373Payá I, Yepes V, González-Vidosa F, Hospitaler A (2008) Multiobjective optimization of reinforced concrete building by simulated annealing. Comput-Aided Civ Inf 23(8):596–610Payá-Zaforteza I, Yepes V, Hospitaler A, González-Vidosa F (2009) CO2-efficient design of reinforced concrete building frames. Eng Struct 31(7):1501–1508Saassouh B, Lounis Z (2012) Probabilistic modeling of chloride-induced corrosion in concrete structures using first- and second-order reliability methods. Cement Concrete Comp 34(9):1082–1093The Concrete Centre (2009) The Concrete Industry Sustainability Performance Report. The Concrete Center, Camberley: http://www.admixtures.org.uk/downloads/Concrete%20Industry%20Sustainable%20Performance%20Report%202009.pdf , accessed 9 September 2012Tuutti K (1982) Corrosion of steel in Concrete. CBI Forskning Research Report, Swedish Cem Concr Res Inst. Stockholm, SwedenWeil M, Jeske U, Schebek L (2006) Closed-loop recycling of construction and demolition waste in Germany in view of stricter environmental threshold values. Waste Manage Res 24(3):197–206World Steel Association (2010) Fact sheet: the three Rs of sustainable Steel. World Steel Association, Brussels: http://www.steel.org/Sustainability/~/media/Files/SMDI/Sustainability/3rs.ashx , accessed 15 September 2012Worrell E, Price L, Martin N, Hendriks C, Meida LO (2001) Carbon dioxide emissions from the global cement industry. Annu Rev Energy Environ 26:303–329Yepes V, González-Vidosa F, Alcalá J, Villalba P (2012) CO2-optimization design of reinforced concrete retaining walls based on a VNS-threshold acceptance strategy. J Comput Civ Eng 26(3):378–386Yiwei T, Qun Z, Jian G (2011) Study on the Life-cycle Carbon Emission and Energy-efficiency Management of the Large-scale Public Buildings in Hangzho. China. International Conference on Computer and Management, Wuhan, pp 546–552Zornoza E, Payá J, Monzó J, Borrachero MV, Garcés P (2009) The carbonation of OPC mortars partially substituted with spent fluid catalytic catalyst (FC3R) and its influence on their mechanical properties. Const Build Mater 23(3):1323–132

Sensitivity of MEG and EEG to Source Orientation

An important difference between magnetoencephalography (MEG) and electroencephalography (EEG) is that MEG is insensitive to radially oriented sources. We quantified computationally the dependency of MEG and EEG on the source orientation using a forward model with realistic tissue boundaries. Similar to the simpler case of a spherical head model, in which MEG cannot see radial sources at all, for most cortical locations there was a source orientation to which MEG was insensitive. The median value for the ratio of the signal magnitude for the source orientation of the lowest and the highest sensitivity was 0.06 for MEG and 0.63 for EEG. The difference in the sensitivity to the source orientation is expected to contribute to systematic differences in the signal-to-noise ratio between MEG and EEG.National Institutes of Health (U.S.) (Grant NS057500)National Institutes of Health (U.S.) (Grant NS037462)National Institutes of Health (U.S.) (Grant HD040712)National Center for Research Resources (U.S.) (P41RR14075)Mind Research Networ

Cell–Matrix De-Adhesion Dynamics Reflect Contractile Mechanics

Measurement of the mechanical properties of single cells is of increasing interest both from a fundamental cell biological perspective and in the context of disease diagnostics. In this study, we show that tracking cell shape dynamics during trypsin-induced de-adhesion can serve as a simple but extremely useful tool for probing the contractility of adherent cells. When treated with trypsin, both SW13−/− epithelial cells and U373 MG glioma cells exhibit a brief lag period followed by a concerted retraction to a rounded shape. The time–response of the normalized cell area can be fit to a sigmoidal curve with two characteristic time constants that rise and fall when cells are treated with blebbistatin and nocodazole, respectively. These differences can be attributed to actomyosin-based cytoskeletal remodeling, as evidenced by the prominent buildup of stress fibers in nocodazole-treated SW13−/− cells, which are also two-fold stiffer than untreated cells. Similar results observed in U373 MG cells highlights the direct association between cell stiffness and the de-adhesion response. Faster de-adhesion is obtained with higher trypsin concentration, with nocodazole treatment further expediting the process and blebbistatin treatment blunting the response. A simple finite element model confirms that faster contraction is achieved with increased stiffness

Supplementary data for the article: Mancic, L.; Djukic-Vukovic, A.; Dinic, I.; Nikolic, M. G.; Rabasovic, M. D.; Krmpot, A. J.; Costa, A. M. L. M.; Marinkovic, B. A.; Mojovic, L.; Milosevic, O. One-Step Synthesis of Amino-Functionalized up-Converting NaYF 4 :Yb,Er Nanoparticles for: In Vitro Cell Imaging. RSC Advances 2018, 8 (48), 27429–27437. https://doi.org/10.1039/c8ra04178d

Supplementary material for: [https://doi.org/10.1039/c8ra04178d]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2225