675 research outputs found
Evaluation and Validation of clinical 4.23 T sodium MRI in animals and human: Application of oblique multi-slice spin-echo pulse sequence
Objective: Application of high-field 4.23 T MRI clinical imager was demonstrated for sodium-magnetic resonance imaging (MRI) data acquisition. Primary hypothesis: Sodium [Na] in brain is MR visible. Secondary hypothesis was, if, application of multislice spin echo (MSSE) pulse sequence at selected scan parameters can sufficiently visualize the total sodium signal as indicator of sub-clinical activity. Material and Methods: MSSE pulse sequence technique was used to simulate sodium images of human brain. For validation purpose, inversion recovery pulse sequence was validated by optimization of scan inversion time (TI). Phantom of sodium and rat brain were imaged. Sodium images were validated and compared with proton MRI images. Results: MSSE pulse technique enabled to visualize the sodium signal at optimized scan parameters. Specifically, MSSE pulse technique enabled the identification of different sodium rich areas due to their subphysiological activity in the brain, comparable with proton MRI images. Reconstruction images of brain further enhanced the power to classify the brain tissue. Intracellular sodium images of agarose-saline solution filled-tube phantom were generated by use of inversion recovery pulse sequence. Conclusion: Using MSSE pulse sequence at 4.23 T, in vivo sodium images can be generated within acceptable scan time for routine clinical brain examination for achieving better sub-physiological information as obtained from proton MRI
Type Ia Supernovae with Bi-Modal Explosions Are Common -- Possible Smoking Gun for Direct Collisions of White-Dwarfs
We discover clear doubly-peaked line profiles in 3 out of ~20 type Ia
supernovae (SNe Ia) with high-quality nebular-phase spectra. The profiles are
consistently present in three well-separated Co/Fe emission features. The two
peaks are respectively blue-shifted and red-shifted relative to the host
galaxies and are separated by ~5000 km/s. The doubly-peaked profiles directly
reflect a bi-modal velocity distribution of the radioactive Ni56 in the ejecta
that powers the emission of these SNe. Due to their random orientations, only a
fraction of SNe with intrinsically bi-modal velocity distributions will appear
as doubly-peaked spectra. Therefore SNe with intrinsic bi-modality are likely
common, especially among the SNe in the low-luminosity part on the Philips
relation (\Delta m15(B) >~ 1.3; ~40% of all SNe Ia). Such bi-modality is
naturally expected from direct collisions of white dwarfs (WDs) due to the
detonation of both WDs and is demonstrated in a 3D 0.64 M_Sun-0.64 M_Sun WD
collision simulation. In the future, with a large sample of nebular spectra and
a comprehensive set of numerical simulations, the collision model can be
unambiguously tested as the primary channel for type Ia SNe, and the
distribution of nebular line profiles will either be a smoking gun or rule it
out.Comment: To be published by MNRAS Letters. Minor changes of the main text, an
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Rapid in vivo Taxotere quantitative chemosensitivity response by 4.23 Tesla sodium MRI and histo-immunostaining features in N-Methyl-N-Nitrosourea induced breast tumors in rats
BACKGROUND: Sodium weighted images can indicate sodium signal intensities from different features in the tumor before and 24 hours following administration of Taxotere. AIM: To evaluate the association of in vivo intracellular sodium magnetic resonance image intensities with immuno-biomarkers and histopathological features to monitor the early tumor response to Taxotere chemotherapy in Methyl-Nitroso-Urea induced rat xenograft breast tumors. METHODS AND MATERIALS: Methyl-Nitroso-Urea (MNU) induced rat xenograft breast tumors were imaged for sodium MRI and compared with tumor histology, immunostaining after 24 hours chemotherapy. RESULTS: Sodium MRI signal intensities represented sodium concentrations. Excised tumor histological sections showed different in vitro histological end points i.e. single strand DNA content of cell nuclei during cell cycle (G1/S-G2/M), distinct S or M histograms (Feulgen labeling to nuclear DNA content by CAS 200), mitotic figures and apoptosis at different locations of breast tumors. Necrosis and cystic fluid appeared gray on intracellular (IC) sodium images while apoptosis rich regions appeared brighter on IC sodium images. After 24 hours Taxotere-treated tumors showed lower 'IC/EC ratio' of viable cells (65–76%) with higher mitotic index; apoptotic tumor cells at high risk due to cytotoxicity (>70% with high apoptotic index); reduced proliferation index (270 vs 120 per high power field) associated with enhanced IC sodium in vivo MR image intensities and decreased tumor size (3%; p < 0.001; n = 16) than that of pre-treated tumors. IC-Na MR signal intensities possibly indicated Taxotere chemosensitivity response in vivo associated with apoptosis and different pre-malignant features within 24 hours of exposure of cancer cells to anti-neoplastic Taxotere drug. CONCLUSION: Sodium MRI imaging may be used as in vivo rapid drug monitoring method to evaluate Taxotere chemosensitivity response associated with neoplasia, apoptosis and tumor histology features
Wireless Sensor Network-Based Service Provisioning by a Brokering Platform
[EN] This paper proposes a business model for providing services based on the Internet of Things through a platform that intermediates between human users and Wireless Sensor Networks (WSNs). The platform seeks to maximize its profit through posting both the price charged to each user and the price paid to each WSN. A complete analysis of the profit maximization problem is performed in this paper. We show that the service provider maximizes its profit by incentivizing all users and all Wireless Sensor Infrastructure Providers (WSIPs) to join the platform. This is true not only when the number of users is high, but also when it is moderate, provided that the costs that the users bear do not trespass a cost ceiling. This cost ceiling depends on the number of WSIPs, on the value of the intrinsic value of the service and on the externality that the WSIP has on the user utility.This work has been supported by the Spanish Ministry of Economy and Competitiveness through Project TIN2013-47272-C2-1-R.Guijarro, L.; Pla, V.; Vidal Catalá, JR.; Naldi, M.; Mahmoodi, T. (2017). Wireless Sensor Network-Based Service Provisioning by a Brokering Platform. Sensors. 17(5):1-25. https://doi.org/10.3390/s17051115S12517
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Disease-modifying therapies alter gut microbial composition in MS.
Objective:To determine the effects of the disease-modifying therapies, glatiramer acetate (GA) and dimethyl fumarate (DMF), on the gut microbiota in patients with MS. Methods:Participants with relapsing MS who were either treatment-naive or treated with GA or DMF were recruited. Peripheral blood mononuclear cells were immunophenotyped. Bacterial DNA was extracted from stool, and amplicons targeting the V4 region of the bacterial/archaeal 16S rRNA gene were sequenced (Illumina MiSeq). Raw reads were clustered into Operational Taxonomic Units using the GreenGenes database. Differential abundance analysis was performed using linear discriminant analysis effect size. Phylogenetic investigation of communities by reconstruction of unobserved states was used to investigate changes to functional pathways resulting from differential taxon abundance. Results:One hundred sixty-eight participants were included (treatment-naive n = 75, DMF n = 33, and GA n = 60). Disease-modifying therapies were associated with changes in the fecal microbiota composition. Both therapies were associated with decreased relative abundance of the Lachnospiraceae and Veillonellaceae families. In addition, DMF was associated with decreased relative abundance of the phyla Firmicutes and Fusobacteria and the order Clostridiales and an increase in the phylum Bacteroidetes. Despite the different changes in bacterial taxa, there was an overlap between functional pathways affected by both therapies. Interpretation:Administration of GA or DMF is associated with differences in gut microbial composition in patients with MS. Because those changes affect critical metabolic pathways, we hypothesize that our findings may highlight mechanisms of pathophysiology and potential therapeutic intervention requiring further investigation
The Diboson Excess: Experimental Situation and Classification of Explanations; A Les Houches Pre-Proceeding
We examine the `diboson' excess at TeV seen by the LHC experiments
in various channels. We provide a comparison of the excess significances as a
function of the mass of the tentative resonance and give the signal cross
sections needed to explain the excesses. We also present a survey of available
theoretical explanations of the resonance, classified in three main approaches.
Beyond that, we discuss methods to verify the anomaly, determining the major
properties of the various surpluses and exploring how different models can be
discriminated. Finally, we give a tabular summary of the numerous explanations,
presenting their main phenomenological features.Comment: 37 pages, 9 Figures, 1 Tabl
David Maldavsky e psicossomática
As anyone who wants to advance a subject, David Maldavsky´s career in the field of psychosomatics began in the development of other authors, particularly Freud, Liberman, Marty & M'Uzan, Lacan, Tustin, Winnicott, Bion and Green. With regard to Freud, it draws attention to its ability to perceive, develop and deepen topics of great clinical and theoretical importance barely hinted at by the father of psychoanalysis, revealing a born researcher, tireless, demanding and of rare sensitivity. Undoubtedly, the originality, depth and creativity with which his work is coated, make Maldavsky among the most outstanding contemporary theorists of psychoanalysis.Como le cabe a quien quiera avanzar en una materia, la trayectoria de David Maldavsky en el campo de la psicosomática tuvo inicio en el desarrollo de otros autores, particularmente Freud, Liberman, Marty & M 'Uzan, Lacan, Tustin, Winnicott, Bion y Green. Con relación a Freud, llama la atención su capacidad de percibir, desarrollar y profundizar temas de gran importancia clínica y teórica apenas insinuados por el padre del psicoanálisis, revelándose un investigador nato, incansable, exigente y de rara sensibilidad. Sin lugar a duda, la originalidad, la profundidad y la creatividad con las cuales se reviste su obra, ponen a Maldavsky entre los teóricos contemporáneos más destacados del psicoanálisis.xx
Prospective unmasked randomized evaluation of the iStent inject (®) versus two ocular hypotensive agents in patients with primary open-angle glaucoma.
PURPOSE: The purpose of this study was to compare outcomes of subjects with open-angle glaucoma (OAG) not controlled on one medication who underwent either implantation of two iStent inject (®) trabecular micro-bypass devices or received medical therapy consisting of a fixed combination of latanoprost/timolol.
PATIENTS AND METHODS: Of 192 subjects who qualified for the study and were enrolled, 94 were randomized to surgery with implantation of two iStent inject(®) devices in the treated eye and 98 to receive medical therapy.
RESULTS: At the month 12 visit, 94.7% of eyes (89/94) in the stent group reported an unmedicated intraocular pressure (IOP) reduction of ≥20% versus baseline unmedicated IOP, and 91.8% of eyes (88/98) in the medical therapy group reported an IOP reduction ≥20% versus baseline unmedicated IOP. A 17.5% between-group treatment difference in favor of the iStent inject group was statistically significant (P=0.02) at the ≥50% level of IOP reduction. An IOP ≤18 mmHg was reported in 92.6% of eyes (87/94) in the iStent inject group and 89.8% of eyes (88/98) in the medical therapy group. Mean (standard deviation) IOP decreases from screening of 8.1 (2.6) mmHg and 7.3 (2.2) mmHg were reported in the iStent inject and medical therapy groups, respectively. A high safety profile was also noted in this study in both the iStent inject and medical therapy groups, as measured by stable best corrected visual acuity, cup-to-disc ratio, and adverse events.
CONCLUSION: These data show that the use of iStent inject is at least as effective as two medications, with the clinical benefit of reducing medication burden and assuring continuous treatment with full compliance to implant therapy as well as having a highly favorable safety profile
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