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1.
Phys Rev Lett ; 123(23): 231101, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31868456

RESUMO

We present the first determination of the Hubble constant H_{0} from strong lensing time delay data and type Ia supernova luminosity distances that is independent of the cosmological model. We also determine the spatial curvature model independently. We assume that light propagation over long distances is described by the Friedmann-Lemaître-Robertson-Walker (FLRW) metric and geometrical optics holds, but make no assumption about the contents of the Universe or the theory of gravity on cosmological scales. We find H_{0}=75.7_{-4.4}^{+4.5} km/s/Mpc and Ω_{K0}=0.12_{-0.25}^{+0.27}. This is a 6% determination of H_{0}. A weak prior from the cosmic microwave background on the distance to the last scattering surface improves this to H_{0}=76.8_{-3.8}^{+4.2} km/s/Mpc and Ω_{K0}=0.18_{-0.18}^{+0.25}. Assuming a zero spatial curvature, we get H_{0}=74.2_{-2.9}^{+3.0} km/s/Mpc, a precision of 4%. The measurements also provide a consistency test of the FLRW metric: we find no evidence against it.

2.
Living Rev Relativ ; 21(1): 2, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29674941

RESUMO

Euclid is a European Space Agency medium-class mission selected for launch in 2020 within the cosmic vision 2015-2025 program. The main goal of Euclid is to understand the origin of the accelerated expansion of the universe. Euclid will explore the expansion history of the universe and the evolution of cosmic structures by measuring shapes and red-shifts of galaxies as well as the distribution of clusters of galaxies over a large fraction of the sky. Although the main driver for Euclid is the nature of dark energy, Euclid science covers a vast range of topics, from cosmology to galaxy evolution to planetary research. In this review we focus on cosmology and fundamental physics, with a strong emphasis on science beyond the current standard models. We discuss five broad topics: dark energy and modified gravity, dark matter, initial conditions, basic assumptions and questions of methodology in the data analysis. This review has been planned and carried out within Euclid's Theory Working Group and is meant to provide a guide to the scientific themes that will underlie the activity of the group during the preparation of the Euclid mission.

4.
PLoS One ; 18(6): e0287123, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37307276

RESUMO

The effects of postural training on postural stability and vestibulospinal reflexes (VSRs) were investigated in normal subjects. A period (23 minutes) of repeated episodes (n = 10, 50 seconds) of unipedal stance elicited a progressive reduction of the area covered by centre of pressure (CoP) displacement, of average CoP displacement along the X and Y axes and of CoP velocity observed in this challenging postural task. All these changes were correlated to each other with the only exception of those in X and Y CoP displacement. Moreover, they were larger in the subjects showing higher initial instability in unipedal stance, suggesting that they were triggered by the modulation of sensory afferents signalling body sway. No changes in bipedal stance occurred soon and 1 hour after this period of postural training, while a reduction of CoP displacement was apparent after 24 hours, possibly due to a beneficial effect of overnight sleep on postural learning. The same period of postural training also reduced the CoP displacement elicited by electrical vestibular stimulation (EVS) along the X axis up to 24 hours following the training end. No significant changes in postural parameters of bipedal stance and VSRs could be observed in control experiments where subjects were tested at identical time points without performing the postural training. Therefore, postural training led to a stricter control of CoP displacement, possibly acting through the cerebellum by enhancing feedforward mechanisms of postural stability and by depressing the VSR, the most important reflex mechanism involved in balance maintenance under challenging conditions.


Assuntos
Terapia de Aceitação e Compromisso , Reflexo , Humanos , Aprendizagem , Cerebelo , Grupos Controle
5.
Rev Recent Clin Trials ; 13(3): 226-237, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29623850

RESUMO

INTRODUCTION: To compare the efficacy of abiraterone acetate, enzalutamide, cabazitaxel and Radium-223 in the treatment of castration-resistant, docetaxel-resistant metastatic prostate cancer. METHODS: An indirect comparison of Overall Survival (OS) and time to PSA progression among abiraterone acetate, enzalutamide, cabazitaxel and Radium-223 was performed with a network metaanalysis. OS in the entire population of patients was the primary endpoint. OS in ECOG 0-1/2, BPISF≤ 4/>4, pretreated with 1 or 2 courses of chemotherapy, age≤65/>65 patients, patients with only bone metastases or bone and visceral metastases, and time to PSA progression were the secondary endpoints. An indirect comparison of the Hazard Ratio and the 95% Confidence Interval was performed, assuming an alpha error of 5% as an index of statistical significance. The among-the-trial heterogeneity was assessed using a qualitative methodological and clinical analysis. RESULTS: Four trials were selected. In three trials, the comparator was placebo, in one trial it was mitoxantrone, the effect of which in improving survival was considered negligible. No significant difference in OS among abiraterone acetate, enzalutamide, cabazitaxel and radium 223 was observed in neither the entire population nor all the subgroups of patients. Enzalutamide resulted significantly better than abiraterone acetate, cabazitaxel or radium-223 in time to PSA progression. CONCLUSION: Since no significant difference in efficacy seems to exist between the four therapeutic options in the treatment of castration-resistant, docetaxel-resistant, metastatic prostate cancer, the safety of the treatment, patient's compliance and costs should represent the criteria to guide clinicians' choice in clinical practice.


Assuntos
Acetato de Abiraterona/uso terapêutico , Antineoplásicos/uso terapêutico , Feniltioidantoína/análogos & derivados , Neoplasias da Próstata/terapia , Rádio (Elemento)/uso terapêutico , Taxoides/uso terapêutico , Benzamidas , Braquiterapia , Docetaxel/uso terapêutico , Humanos , Masculino , Metanálise em Rede , Nitrilas , Orquiectomia , Feniltioidantoína/uso terapêutico , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
6.
J Pain Symptom Manage ; 32(4): 372-7, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17000354

RESUMO

The neuropeptide nociceptin/orphanin FQ (N/OFQ) is the endogenous ligand for the opioid-like receptor ORL-1 and is thought to be involved in pain transmission and modulation. Human studies have not yet defined its role in pain patients. The aims of this study were 1) to verify the presence of N/OFQ in the cerebrospinal fluid (CSF) of human controls and patients with chronic noncancer pain, including those treated with intrathecally administered morphine, and 2) to determine whether pain or treatment with long-term intrathecal morphine influences its levels. The CSF of 27 patients (nine controls and 18 with chronic noncancer pain, of whom 12 were treated chronically with intrathecally administered morphine and six were opioid naïve) was analyzed, blindly, with radioimmunoassay methods. N/OFQ was detected in all patients. Mean CSF concentrations were lowest in the morphine-treated group and highest in the untreated chronic pain patients (12.06+/-1.19 and 57.41+/-10.06 fmol/ml, respectively), and the difference between the morphine-treated group and controls was statistically significant (44.72+/-13.56 fmol/ml, P<0.05). The presence of N/OFQ peptide in human CSF may correlate with biological activities that are influenced by different pain states and long-term intrathecal-morphine treatment. Further studies should verify whether the determination of this peptide CSF level may provide information on opioid treatment efficacy and on the presence of opioid tolerance.


Assuntos
Morfina/administração & dosagem , Peptídeos Opioides/líquido cefalorraquidiano , Medição da Dor/efeitos dos fármacos , Dor/líquido cefalorraquidiano , Dor/tratamento farmacológico , Idoso , Analgésicos Opioides/administração & dosagem , Biomarcadores/líquido cefalorraquidiano , Doença Crônica , Feminino , Humanos , Injeções Espinhais , Masculino , Pessoa de Meia-Idade , Dor/diagnóstico , Medição da Dor/métodos , Nociceptina
7.
Rev Recent Clin Trials ; 11(4): 317-323, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27448518

RESUMO

BACKGROUND: To assess the role of docetaxel plus androgen deprivation in metastatic, hormone- sensitive prostate cancer. METHODS: A qualitative systematic review of literature was performed. All the randomized phase III trials comparing docetaxel plus androgen deprivation with androgen deprivation alone in patients with metastatic, hormone-sensitive prostate cancer were considered eligible and included into the analysis. RESULTS: Six papers (3 randomized clinical trials, and 3 systematic reviews with meta-analysis) were considered eligible and included into the analysis. A significant improvement in time to progression and OS in the entire population treated with docetaxel plus androgen deprivation was reported in all the trials and meta-analyses, and in two trials and all meta-analyses, respectively. One trial reported improvement of OS only in patients with high volume disease, and the meta-analysis that also analyzed the subgroups of patients with high or low volume disease reported a benefit of docetaxel plus androgen deprivation for either the entire population or the two subgroups of patients. CONCLUSION: The early use of docetaxel combined with androgen deprivation improves the main outcomes in the treatment of metastatic, hormone-sensitive prostate cancer. The available data suggest that docetaxel plus androgen deprivation could be considered the novel standard for fit patients with metastatic, hormone-sensitive prostate cancer.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Taxoides/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica , Docetaxel , Humanos , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto
8.
Phys Med Biol ; 49(9): 1739-54, 2004 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-15152928

RESUMO

A system for in vivo breast imaging with monochromatic x-rays has been designed and built at the synchrotron radiation facility Elettra in Trieste (Italy) and will be operational in 2004. The system design involves the possibility of performing both planar mammography and breast tomography. In the present work, the first results obtained with a test set-up for breast tomography are shown and discussed. Tomographic images of in vitro breasts were acquired using monochromatic x-ray beams in the energy range 20-28 keV and a linear array silicon pixel detector. Tomograms were reconstructed using standard filtered backprojection algorithms; the effect of different filters was evaluated. The attenuation coefficients of fibroglandular and adipose tissue were measured, and a quantitative comparison of images acquired at different energies was performed by calculating the differential signal-to-noise ratio of fibroglandular details in adipose tissue. All images required a dose comparable to the dose delivered in clinical, conventional mammography and showed a high resolution of the breast structures without the overlapping effects that limit the visibility of the structures in 2D mammography. A quantitative evaluation of the images proves that the image quality at a given dose increases in the considered energy range and for the considered breast sizes.


Assuntos
Mama/patologia , Síncrotrons , Tomografia Computadorizada por Raios X/métodos , Tecido Adiposo/diagnóstico por imagem , Tecido Adiposo/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Tecido Conjuntivo/diagnóstico por imagem , Tecido Conjuntivo/patologia , Humanos , Aumento da Imagem , Itália , Mamografia/instrumentação , Mamografia/métodos , Radiação , Doses de Radiação , Silício , Tomografia Computadorizada por Raios X/instrumentação
9.
Acta Crystallogr A ; 60(Pt 1): 40-50, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14691326

RESUMO

A new formalism is presented concerning the dynamics of X-rays in crystals. It is based on Takagi's equations and Fourier optics; it also offers an alternative to the usual Ewald-von Laue approach. The article does not give new results but shows a new way to formulate the dynamical theory of X-ray diffraction. In addition, it proposes a novel description of X-ray propagation based on the analogy between the dynamics of X-rays in crystals and that of two-level quantum systems.

10.
J Synchrotron Radiat ; 11(Pt 3): 248-53, 2004 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-15103111

RESUMO

This report discusses the optimization strategy, the theoretical background and first experimental data of a new refractive lens for focusing X-rays. In order to reduce the absorption of X-rays in this transmission lens, optically passive material was removed from the necessarily concave lens shape in a highly regular pattern. The feature dimensions require lens production and replication by deep X-ray lithography, which allows shaping in only one dimension. Consequently such a lens can focus in one direction only, so a crossed lens pair is needed for two-dimensional focusing. The single lens is composed of two large prisms of millimetre size, which touch each other at one of the tips, like an old sand clock. Each large prism contains a highly regular structure of essentially identical prism-like smaller segments. The first lens prototypes focused an X-ray beam with a vertical size of 500 microm and a photon energy of 8 keV to a line with a width of only 2.8 microm. This is only slightly worse than the line width of 1.73 microm expected for its focal length of f = 2.18 m. The photon density enhancement in the focus was 25, but could have been larger as the lens can intercept a beam height of 2.6 mm.

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