995 resultados para Watts, Isaac, 1674-1748


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We determine the structure of neutron stars within a Brueckner-Hartree-Fock approach based on realistic nucleon-nucleon, nucleon-hyperon, and hyperon-hyperon interactions. Our results indicate rather low maximum masses below 1.4 solar masses. This feature is insensitive to the nucleonic part of the EOS due to a strong compensation mechanism caused by the appearance of hyperons and represents thus strong evidence for the presence of nonbaryonic "quark" matter in the interior of heavy stars.

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The interaction of the low-lying pseudoscalar mesons with the ground-state baryons in the charm sector is studied within a coupled-channel approach using a t-channel vector-exchange driving force. The amplitudes describing the scattering of the pseudoscalar mesons off the ground-state baryons are obtained by solving the Lippmann-Schwinger equation. We analyze in detail the effects of going beyond the t=0 approximation. Our model predicts the dynamical generation of several open-charm baryon resonances in different isospin and strangeness channels, some of which can be clearly identified with recently observed states.

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Substantial collective flow is observed in collisions between lead nuclei at Large Hadron Collider (LHC) as evidenced by the azimuthal correlations in the transverse momentum distributions of the produced particles. Our calculations indicate that the global v1-flow, which at RHIC peaked at negative rapidities (named third flow component or antiflow), now at LHC is going to turn toward forward rapidities (to the same side and direction as the projectile residue). Potentially this can provide a sensitive barometer to estimate the pressure and transport properties of the quark-gluon plasma. Our calculations also take into account the initial state center-of-mass rapidity fluctuations, and demonstrate that these are crucial for v1 simulations. In order to better study the transverse momentum flow dependence we suggest a new "symmetrized" v1S(pt) function, and we also propose a new method to disentangle global v1 flow from the contribution generated by the random fluctuations in the initial state. This will enhance the possibilities of studying the collective Global v1 flow both at the STAR Beam Energy Scan program and at LHC.

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Comprend : [Tome I. Bandeau à la Dédicace : lion et licorne entourant les armoiries et la devise du Duc de Glocester.] Honi soit qui mal y pense. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome I. Pl. en reg. folio B : la Thébaïde ou les frères ennemis. Tragédie.] Thébaïde. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome I. Pl. en reg. du titre de la tragédie Alexandre le grand :] Alexandre. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome I. Pl. en reg. du titre de la tragédie Andromaque :] Andromaque. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome I. Pl. en reg. du titre de la tragédie Britannicus :] Britannicus. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome I. Pl. en reg. du titre de la tragédie Berenice :] Berenice. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome I. Pl. en reg. du titre de la comédie Les Plaideurs :] Les Plaideurs. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome II. Frontispice :] [Cote : Yf 404-405/Microfilm R 122414] ; [Tome II. Pl. en reg. du titre de la tragédie Bajazet :] Bajazet. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome II. Pl. en reg. du titre de la tragédie Mithridate :] Mithridate. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome II. Pl. en reg. du titre de la tragédie Iphigénie :] Iphigénie. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome II. Pl. en reg. du titre de la tragédie Phèdre :] Phèdre. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome II. Pl. en reg. du titre de la tragédie Esther :] Esther. [Cote : Yf 404-405/Microfilm R 122414] ; [Tome II. Pl. en reg. du titre de la tragédie Athalie :] Athalie. [Cote : Yf 404-405/Microfilm R 122414]

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BACKGROUND: Whole pelvis intensity modulated radiotherapy (IMRT) is increasingly being used to treat cervical cancer aiming to reduce side effects. Encouraged by this, some groups have proposed the use of simultaneous integrated boost (SIB) to target the tumor, either to get a higher tumoricidal effect or to replace brachytherapy. Nevertheless, physiological organ movement and rapid tumor regression throughout treatment might substantially reduce any benefit of this approach. PURPOSE: To evaluate the clinical target volume - simultaneous integrated boost (CTV-SIB) regression and motion during chemo-radiotherapy (CRT) for cervical cancer, and to monitor treatment progress dosimetrically and volumetrically to ensure treatment goals are met. METHODS AND MATERIALS: Ten patients treated with standard doses of CRT and brachytherapy were retrospectively re-planned using a helical Tomotherapy - SIB technique for the hypothetical scenario of this feasibility study. Target and organs at risk (OAR) were contoured on deformable fused planning-computed tomography and megavoltage computed tomography images. The CTV-SIB volume regression was determined. The center of mass (CM) was used to evaluate the degree of motion. The Dice's similarity coefficient (DSC) was used to assess the spatial overlap of CTV-SIBs between scans. A cumulative dose-volume histogram modeled estimated delivered doses. RESULTS: The CTV-SIB relative reduction was between 31 and 70%. The mean maximum CM change was 12.5, 9, and 3 mm in the superior-inferior, antero-posterior, and right-left dimensions, respectively. The CTV-SIB-DSC approached 1 in the first week of treatment, indicating almost perfect overlap. CTV-SIB-DSC regressed linearly during therapy, and by the end of treatment was 0.5, indicating 50% discordance. Two patients received less than 95% of the prescribed dose. Much higher doses to the OAR were observed. A multiple regression analysis showed a significant interaction between CTV-SIB reduction and OAR dose increase. CONCLUSIONS: The CTV-SIB had important regression and motion during CRT, receiving lower therapeutic doses than expected. The OAR had unpredictable shifts and received higher doses. The use of SIB without frequent adaptation of the treatment plan exposes cervical cancer patients to an unpredictable risk of under-dosing the target and/or overdosing adjacent critical structures. In that scenario, brachytherapy continues to be the gold standard approach.

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This article reviews nanoparticulate-chemotherapeutic systems that have been developed for human therapy, considering the components of the nanoparticles, the therapeutic agents associated with the nanoparticles and the clinical indications these therapeutic nanoparticles have been developed for. In this evaluation we have put into perspective the types of nanomaterials and their therapeutic indications. We have reviewed the nanoparticulate-chemotherapeutic systems that have been published, approved and marketed and that are currently in clinical use. We have also analyzed the nanoparticulate-chemotherapeutic systems that are in clinical trials and under preclinical development.

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Research on regulation has crossed paths with the literature on policy instruments, showing that regulatory policy instruments contain cognitive and normative beliefs about policy. Thus, their usage stacks the deck in favor of one type of actor or one type of regulatory solution. In this article, we challenge the assumption that there is a predetermined relationship between ideas, regulatory policy instruments, and outcomes. We argue that different combinations of conditions lead to different outcomes, depending on how actors use the instrument. Empirically, we analyze 31 EU and UK case studies of regulatory impact assessment (RIA) - a regulatory policy instrument that has been pivotal in the so-called better regulation movement. We distinguish four main usages of RIA, that is, political, instrumental, communicative, and perfunctory. We find that in our sample instrumental usage is not so rare and that the contrast between communicative and political usages is less stark than is commonly thought. In terms of policy recommendations, our analysis suggests that there may be different paths to desirable outcomes. Policymakers should therefore explore different combinations of conditions leading to the usages they deem desirable rather than arguing for a fixed menu of variables.

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Performing a post-mortem multidetector CT (MDCT) scan has already become routine in some institutes of forensic medicine. To better visualize the vascular system, different techniques of post-mortem CT-angiography have been explored, which can essentially be divided into partial- and whole-body angiography techniques. Probably the most frequently applied technique today is the so-called multiphase post-mortem CT-angiography (MPMCTA) a standardized method for investigating the vessels of the head, thorax and abdomen. Different studies exist, describing its use for medicolegal investigations, and its advantages as well as its artefacts and pitfalls. With the aim to investigate the performance of PMCTA and to develop and validate techniques, an international working group was created in 2012 called the "Technical Working Group Post-mortem Angiography Methods" (TWGPAM). Beyond its primary perspective, the goals of this group include creating recommendations for the indication of the investigation and for the interpretation of the images and to distribute knowledge about PMCTA. This article provides an overview about the different approaches that have been developed and tested in recent years and an update about ongoing research in this field. It will explain the technique of MPMCTA in detail and give an outline of its indications, application, advantages and limitations.