3,032 research outputs found
Assessment of CF lung disease using motion corrected PROPELLER MRI: a comparison with CT
No full textTo date, PROPELLER MRI, a breathing-motion-insensitive technique, has not been assessed for cystic fibrosis (CF) lung disease. We compared this technique to CT for assessing CF lung disease in children and adults. Thirty-eight stable CF patients (median 21 years, range 6-51 years, 22 female) underwent MRI and CT on the same day. Study protocol included respiratory-triggered PROPELLER MRI and volumetric CT end-inspiratory and -expiratory acquisitions. Two observers scored the images using the CF-MRI and CF-CT systems. Scores were compared with intra-class correlation coefficient (ICC) and Bland-Altman plots. The sensitivity and specificity of MRI versus CT were calculated. MRI sensitivity for detecting severe CF bronchiectasis was 0.33 (CI 0.09-0.57), while specificity was 100 % (CI 0.88-1). ICCs for bronchiectasis and trapped air were as follows: MRI-bronchiectasis (0.79); CT-bronchiectasis (0.85); MRI-trapped air (0.51); CT-trapped air (0.87). Bland-Altman plots showed an MRI tendency to overestimate the severity of bronchiectasis in mild CF disease and underestimate bronchiectasis in severe disease. Motion correction in PROPELLER MRI does not improve assessment of CF lung disease compared to CT. However, the good inter- and intra-observer agreement and the high specificity suggest that MRI might play a role in the short-term follow-up of CF lung disease (i.e. pulmonary exacerbations). aEuro cent PROPELLER MRI does not match CT sensitivity to assess CF lung disease. aEuro cent PROPELLER MRI has lower sensitivity than CT to detect severe bronchiectasis. aEuro cent PROPELLER MRI has good to very good intra- and inter-observer variability. aEuro cent PROPELLER MRI can be used for short-term follow-up studies in CF
Receiver Windowing Design for Narrowband Interference Mitigation in MB-OFDM UWB System
No full textIn 2005, the WiMedia Alliance working with the European Computer Manufacturers Association (ECMA) announced the establishment of the WiMedia MB-OFDM (Multiband Orthogonal Frequency Division Multiplexing) UWB radio platform as their global UWB standard. It was also chosen as the physical layer (PHY) of high data rate wireless specifications for high speed Wireless USB (W-USB), Bluetooth 3.0 and Wireless High-Definition Media Interface (HDMI). However, due to the low power and wide bandwidth nature of UWB systems, in-band narrowband interference (NBI) may hinder the receiver performance. This thesis presents an analysis of NBI impact on the MB-OFDM system for UWB communication. The intent of our analysis is to provide practical solutions for interference mitigation under different NBI models. In our work, a new receiver windowing for zero padding (ZP) OFDM system is proposed to reduce NBI spreading in the MB-OFDM UWB system. Simulations demonstrate the effectiveness of windowing under different NBI models.Microelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc
Altered immunolocalization of FGF23 in murine femora metastasized with human breast carcinoma MDA-MB-231 cells
No full textIntroduction After the onset of bone metastasis, tumor cells appear to modify surrounding microenvironments for their benefit, and particularly, the levels of circulating fibroblast growth factor (FGF) 23 in patients with tumors have been highlighted. Materials and methods We have attempted to verify if human breast carcinoma MDA-MB-231 cells metastasized in the long bone of nu/nu mice would synthesize FGF23. Serum concentrations of calcium, phosphate (Pi) and FGF23 were measured in control nu/nu mice, bone-metastasized mice, and mice with mammary gland injected with MDA-MB-231 cells mimicking primary mammary tumors. Results and conclusions MDA-MB-231 cells revealed intense FGF23 reactivity in metastasized lesions, whereas MDA-MB-231 cells cultured in vitro or when injected into the mammary glands (without bone metastasis) showed weak FGF23 immunoreactivity. Although the bone-metastasized MDA-MB-231 cells abundantly synthesized FGF23, osteocytes adjacent to the FGF23-immunopositive tumors, unlike intact osteocytes, showed no FGF23. Despite significantly elevated serum FGF23 levels in bone-metastasized mice, there was no significant decrease in the serum Pi concentration when compared with the intact mice and mice with a mass of MDA-MB-231 cells in mammary glands. The metastasized femora showed increased expression and FGFR1 immunoreactivity in fibroblastic stromal cells, whereas femora of control mice showed no obvious FGFR1 immunoreactivity. Taken together, it seems likely that MDA-MB-231 cells synthesize FGF23 when metastasized to a bone, and thus affect FGFR1-positive stromal cells in the metastasized tumor nest in a paracrine manner
Artrite reumatóide: diagnóstico e tratamento
No full textDESCRIÇÃO DO MÉTODO DE COLETA DE EVIDÊNCIAS: Reunião consensual e multidisciplinar com a participação de médicos reumatologistas, fisiatra e ortopedista para elaboração do texto final. O texto inicial tomou por base o documento do Colégio Americano de Reumatologia "Guidelines for the management of rheumatoid arthritis" e também o texto das "Diretrizes do Ministério da Saúde para o Diagnóstico e Tratamento da Artrite Reumatóide", acrescido da experiência de reumatologistas, e complementado por extensa revisão bibliográfica, com prioridade para meta-análises. Os participantes, divididos em três grupos, produziram o texto básico, cujas recomendações foram submetidas à revisão e à aprovação pelo conjunto dos participantes. Depois, disponibilizados na internet, foi objeto de novas sugestões por parte de outros especialistas, até alcançar a forma final. GRAU DE RECOMENDAÇÃO E FORÇA DE EVIDÊNCIA: A: Estudos experimentais e observacionais de melhor consistência. B: Estudos experimentais e observacionais de menor consistência. C: Relatos de casos (estudos não controlados). D: Opinião desprovida de avaliação crítica, baseada em consensos, estudos fisiológicos ou modelos animais. OBJETIVOS: Estabelecer diretrizes claras e sucintas para o diagnóstico e tratamento da artrite reumatóide. CONFLITO DE INTERESSE: Os autores Laurindo IMM, Ximenes AC, Lima FAC, Pinheiro GRC, Bertolo MB, Xavier RM, Ciconelli RM e Radominski SC declararam vínculo com a Indústria Farmacêutica
ASIC FFT processor for MB-OFDM UWB system
No full textThe physical layer (PHY) standard of Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM) Ultra Wideband (UWB) system was defined by ECMA International. In this standard, the data sampling rate from the analog-to-digital converter to the physical layer is up to 528 Msample/s. Therefore, it is a challenge to realize the physical layer of the UWB system-especially the components with high computational complexity in Very Large Scale Integration (VLSI) implementation. Fast Fourier Transform (FFT) block is one of these components. FFT plays an important role in Multi-band OFDM UWB system, which is the demodulation block of OFDM signals. The purpose of this project is to design an Application Specific Integrated Circuit (ASIC) FFT solution for this system. The specification is defined from the system analysis and literature research. All the design choices and considerations are concluded and explained.Based on the algorithm and architecture analysis, a novel Radix22Parallel processor is proposed, which is a small-area and low-power-consumption solution for MB-OFDM UWB system. Both Field Programmable Gate Array (FPGA) and ASIC targeted synthesis results of this architecture are presented.Electrical Engineering, Mathematics and Computer Scienc
Characterization of the tertiary structure of the de novo designed protein MB-1
No full textMilk Bundle-1 (MB-1) is a de novo designed protein with 100 amino acids, having a molecular weight of 11.4 kilodaltons. MB-1 is enriched with 57% of selected essential amino acids (methionine, threonine, lysine and leucine), which are known to be limiting in dairy cattle. Recently, on the basis of a digestibility study, MB-1 was predicted to be unstable in rumen conditions.Characterization of the protein's structure was achieved using fluorescence spectroscopy (steady state measurements). MB-1 contains one tyrosine at position 62, expected to be in position "d" of helix III, in the hydrophobic core. Data obtained using fluorescence quenching indicates that the tyrosine is protected from the solvent in the putative hydrophobic core, as per design.Once it was established that MB-1 was not misfolded, further experiments were done to assess the fluidity of its hydrophobic core. For this, the amphiphillic dye ANSA was used. Results obtained for MB-1 compare favourably to those of many natural proteins, suggesting that MB-1 has achieved some degree of nativeness. Interestingly, MB-1 was found to exclude ANSA from its hydrophobic core more efficiently than all other de novo designed proteins reported to date.Finally, an analysis of folding thermodynamics of MB-1 was attempted. It was found that the fluorescence intensity of tyrosine was not sensitive to unfolding, making thermodynamic data impossible to obtain.Analysis of the data on MB-1 as compared to other natural proteins indicates that MB-1 is folded and compact. The lack of resistance to proteases must be caused by other factors other than the lack of compactness or misfolding. (Abstract shortened by UMI.).Source: Masters Abstracts International, Volume: 36-06, page: 1623.Adviser: Marc Beauregard
Stochastic Lie bracket (derivation, derivation) in MB-algebras
No full textBy a stochastic controller, we make stable the pseudo stochastic Lie bracket (derivation, derivation) in complex MB-algebras. Next, we get an approximation by a stochastic Lie bracket (derivation, derivation) and calculate the maximum error of the estimate. © 2020, The Author(s)
Weerkat: An extensible semantic Wiki
No full textWikis are Web applications that blur the boundaries between readers and authors, allowing non-technical people to author hypertexts through a web interface. A Semantic Wiki is a Wiki that attempts the same thing with the Semantic Web, allowing non-technical users to create semantic resources and/or ontologies. In this paper we characterise the different ways in which a Wiki might support the Semantic Web and present Weerkat, a modular and extensible Wiki that has ontological hypertext support. Key to this has been the design and development of a highly flexible Wiki architecture which allows easy modification and augmentation of functionality
Analysis of Safe and Effective Next-Generation Rail Signalling Systems using a FTA-SAN Approach
No full textMoving Block (MB) and Virtual Coupling (VC) rail signalling will change current train operation paradigm by migrating vital equipment from trackside to onboard to reduce train separation and maintenance costs. Their actual deployment is however constrained by the industry’s need to identify configurations of MB and VC signalling equipment which can effectively guarantee safe train movements even under degraded operational conditions involving component faults. In this paper, we analyse the effectivity of MB and VC in safely supervising train separation under nominal and degraded conditions by using an innovative approach which combines Fault Tree Analysis (FTA) and Stochastic Activity Network (SAN). A FTA model of unsafe train movement is defined for both MB and VC capturing functional interactions and cause effect relations among the different signalling components. The FTA is then used as a basis to apportion signalling component failure rates needed to feed the SAN model. Effective MB and VC train supervision is analysed by means of SAN-based simulations in the specific scenario of an error in the Train Position Reporting (TPR) for five rail market segments featuring different traffic characteristics, namely high-speed, mainline, regional, urban and freight. Results show that the overall approach can support infrastructure managers, railway undertakings, and rail system suppliers in investigating effectiveness of MB and VC in safely supervising train movements in scenarios involving different types of degraded conditions and failure events. The proposed method can hence support the railway industry in identifying effective and safe design configurations of next-generation rail signalling systems.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Transport and Plannin
LA-MB-FTMW STUDIES OF SUGARS
No full textAuthor Institution: Grupo de Espectroscopia Molecular (GEM). Edificio Quifima. Laboratorios de Espectroscopia y Bioespectroscopia. Parque Cientifico. Universidad de Valladolid, 47011 Valladolid. (Spain)Recently, rotational studies of biomolecules have entered in a new stage with the LA-MB-FTMW experiment. \textbf{11},617-627 (2009)and references therein} It combines laser ablation with Fourier transform microwave spectroscopy in supersonic jets overcoming the problems of thermal decomposition associated with conventional heating methods. This technique has been successfully applied to the study of monosaccarides. Three conformers of the prototype -D-glucose and other three for -D-glucose have been characterized for the first time in the gas phase
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