3,462 research outputs found

    Multiscale model for the effects of adaptive immunity suppression on the viral therapy of cancer

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    Oncolytic virotherapy - the use of viruses that specifically kill tumor cells - is an innovative and highly promising route for treating cancer. However, its therapeutic outcomes are mainly impaired by the host immune response to the viral infection. In the present work, we propose a multiscale mathematical model to study how the immune response interferes with the viral oncolytic activity. The model assumes that cytotoxic T cells can induce apoptosis in infected cancer cells and that free viruses can be inactivated by neutralizing antibodies or cleared at a constant rate by the innate immune response. Our simulations suggest that reprogramming the immune microenvironment in tumors could substantially enhance the oncolytic virotherapy in immune-competent hosts. Viable routes to such reprogramming are either in situ virus-mediated impairing of CD8+8^+ T cells motility or blockade of B and T lymphocytes recruitment. Our theoretical results can shed light on the design of viral vectors or new protocols with neat potential impacts on the clinical practice.Comment: 14 pages, 4 figure

    Photoassociative ionization of Na inside a storage ring

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    Motivated by recent interest in low dimensional arrays of atoms, we experimentally investigated the way cold collisional processes are affected by the geometry of the considered atomic sample. More specifically, we studied the case of photoassociative ionization (PAI) both in a storage ring where collision is more unidirectional in character and in a trap with clear undefinition of collision axis. First, creating a ring shaped trap (atomotron) we investigated two-color PAI dependence with intensity and polarization of a probing laser. The intensity dependence of the PAI rate was also measured in a magneto-optical trap presenting equivalent temperature and density conditions. Indeed, the results show that in the ring trap, the value of the PAI rate constant is much lower and does not show evidences of saturation, unlike in the case of the 3D-MOT. Cold atomic collisions in storage ring may represent new possibilities for study.Comment: 5 pages, 5 figures; Accepted by Optics Communicatio

    Variação genética entre procedências de seringueira.

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    Plantas de seringueira (Hevea spp.) com um ano de idade originadas de sementes de seringais nativos dos estados do Acre, Mato Grosso e Rondonia, envolvendo 36 amostras de 14 locais distintos, foram avaliadas para diametro de caule, altura de planta e numero de lancamentos. A incidencia de doencas foi avaliada quando as plantas tinham 17 meses de idade. O delineamento utilizado foi o latice triplo 6 x 6, com 50 plantas por parcela, no espacamento de 4,0 m x 4.0 m. As procedencias RO/CM/10, MT/C/04 e MT/C/06 apresentaram-se como as mais vigorosas, enquanto que AC/S/08 e AC/S/11 demonstraram pobre vigor nessa fase de desenvolvimento. As procedencias de seringais nativos localizadas em areas de varzeas estao apresentando melhor vigor. Em geral, as originadas de Rodonia apresentam-se mais vigorosas que as do Acre e Mato Grosso. As procedencias originadas de Rondonia, Mato Grosso e Acre apresentaram proporcionalmente maior contribuicao sobre a variacao estimada dentro de procedendia em cada Estado para as caracteristicas que determinam vigor de planta. Os parametros utilizados para avaliacao da variabilidade genetica na populacao detectaram alta variabilidade aproveitavel na selecao. Todas as procedencias foram altamente infectadas pelo Microccyclus ulei, ao passo que a incidencia de Thanatephorus cucumeris e Colletotrichum gloeosporioides foi menos intensa e mais variavel

    Modulation of charge-density waves by superlattice structures

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    We discuss the interplay between electronic correlations and an underlying superlattice structure in determining the period of charge density waves (CDW's), by considering a one-dimensional Hubbard model with a repeated (non-random) pattern of repulsive (U>0) and free (U=0) sites. Density matrix renormalization group diagonalization of finite systems (up to 120 sites) is used to calculate the charge-density correlation function and structure factor in the ground state. The modulation period can still be predicted through effective Fermi wavevectors, k_F*, and densities, and we have found that it is much more sensitive to electron (or hole) doping, both because of the narrow range of densities needed to go from q*=0 to \pi, but also due to sharp 2k_F*-4k_F* transitions; these features render CDW's more versatile for actual applications in heterostructures than in homogeneous systems.Comment: 4 pages, 5 figures, to appear in Phys Rev

    The impact of financial restatements on financial markets: A systematic review of the literature

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    Purpose: The purpose of this paper is to discuss the most relevant issues related to the impact of financial restatements in the dynamics of financial markets and identify several research gaps to be investigated in future research. Design/methodology/approach: The methodology is based on a systematic review of the literature described by Tranfield et al. (2003). The final sample includes 47 academic papers published from 1996 to 2019. Findings: Papers in this domain discuss three main topics: how the market prices the announcement of a financial restatement; how financial restatements affect the announcing firm’s cost of capital and how financial restatements affect firms’ reputation. There are several issues to explore in future research, including whether financial restatements affect the dynamics of financial markets in Europe, whether the market fully and promptly assimilates the information content of a restatement, the role of financial analysts’ information disclosures in this process or how regulators may improve the way they provide investors with timely information about firms’ restating problems. Research limitations/implications: There is always some degree of subjectivity in the definition of the keywords, search strings and selection criteria in a systematic review. These are all important aspects, as they delimitate the scope of the study and define the sample of papers to be reviewed. Practical implications: The answers to the research questions identified in this paper may provide regulators with information to improve financial accounting and reporting standards and strengthen investors’ confidence in accounting information and the dynamics of financial markets. Originality/value: This paper systematically reviews the relevant literature exploring the connection between financial restatements and the dynamics of financial markets. It contributes to the academic community by identifying several research questions that may impact the theory and practice related to accounting quality and capital markets.info:eu-repo/semantics/acceptedVersio

    L’utilisation combinée des scores GRACE et CRUSADE pour la stratification du risque d’infarctus du myocarde

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    BACKGROUND: Risk assessment is fundamental in the management of acute coronary syndromes (ACS), enabling estimation of prognosis. AIMS: To evaluate whether the combined use of GRACE and CRUSADE risk stratification schemes in patients with myocardial infarction outperforms each of the scores individually in terms of mortality and haemorrhagic risk prediction. METHODS: Observational retrospective single-centre cohort study including 566 consecutive patients admitted for non-ST-segment elevation myocardial infarction. The CRUSADE model increased GRACE discriminatory performance in predicting all-cause mortality, ascertained by Cox regression, demonstrating CRUSADE independent and additive predictive value, which was sustained throughout follow-up. The cohort was divided into four different subgroups: G1 (GRACE<141; CRUSADE<41); G2 (GRACE<141; CRUSADE≥41); G3 (GRACE≥141; CRUSADE<41); G4 (GRACE≥141; CRUSADE≥41). RESULTS: Outcomes and variables estimating clinical severity, such as admission Killip-Kimbal class and left ventricular systolic dysfunction, deteriorated progressively throughout the subgroups (G1 to G4). Survival analysis differentiated three risk strata (G1, lowest risk; G2 and G3, intermediate risk; G4, highest risk). The GRACE+CRUSADE model revealed higher prognostic performance (area under the curve [AUC] 0.76) than GRACE alone (AUC 0.70) for mortality prediction, further confirmed by the integrated discrimination improvement index. Moreover, GRACE+CRUSADE combined risk assessment seemed to be valuable in delineating bleeding risk in this setting, identifying G4 as a very high-risk subgroup (hazard ratio 3.5; P<0.001). CONCLUSIONS: Combined risk stratification with GRACE and CRUSADE scores can improve the individual discriminatory power of GRACE and CRUSADE models in the prediction of all-cause mortality and bleeding. This combined assessment is a practical approach that is potentially advantageous in treatment decision-making

    Raça Morada Nova: origem, características e perspectivas.

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