185 research outputs found

    Quadratic Algebra associated with Rational Calogero-Moser Models

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    Classical Calogero-Moser models with rational potential are known to be superintegrable. That is, on top of the r involutive conserved quantities necessary for the integrability of a system with r degrees of freedom, they possess an additional set of r-1 algebraically and functionally independent globally defined conserved quantities. At the quantum level, Kuznetsov uncovered the existence of a quadratic algebra structure as an underlying key for superintegrability for the models based on A type root systems. Here we demonstrate in a universal way the quadratic algebra structure for quantum rational Calogero-Moser models based on any root systems.Comment: 19 pages, LaTeX2e, no figure

    Efficacy and safety of percutaneous radiofrequency thermal ablation in the treatment of lung cancer lesions.

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    INTRODUCTION: In this study, we reviewed a clinical series composed by all malignant lung lesions submitted to computed tomography-guided percutaneous thermal radiofrequency ablation, in our hospital, a rather recent technique that has been gaining scientific recognition. MATERIAL AND METHODS: For data purposes, all radiofrequency ablation and corresponding clinical records were retrospectively analysed. A computed tomography scan was performed before and after each procedure to evaluate the tumour's features, and at a second step to assess results and complications. The frequency of local recurrence and disease progression were determined based on imaging follow-up. Kaplan-Meier analysis was used to estimate survival. Univariate analysis recognized clinical and pathological factors affecting survival. These were also tested by multivariate analysis. RESULTS: A total of 28 malignant lung lesions, 20 primary and 8 metastatic, from 28 patients (78.6% male; mean age 62 ± 17 years old), were submitted to computed tomography-guided radiofrequency ablation between January 2004 and July 2010. Total necrosis was achieved in 74.1% of the lesions. Immediate radiofrequency ablation-related complications were observed in half of the procedures. Among major complications, death occurred in one patient only. Median overall survival was 43.0 months for a mean 2-years follow-up.Median progression-free survival was 31.6 months. Lesion's size smaller than 35 mm, stage III disease by the TNM classification and previous treatment attempts were significantly associated with better outcomes. Disease-related mortality was 46.4%. DISCUSSION: This procedure proved to be efficient to treat lung cancerous lesions, with a low-rate of major complications. CONCLUSIONS: Computed tomography-guided percutaneous radiofrequency ablation is a minimally invasive procedure that appears to be valuable in the treatment of lung cancer lesions

    Observations of the post shock break-out emission of SN 2011dh with XMM-Newton

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    After the occurrence of the type cIIb SN 2011dh in the nearby spiral galaxy M 51 numerous observations were performed with different telescopes in various bands ranging from radio to gamma-rays. We analysed the XMM-Newton and Swift observations taken 3 to 30 days after the SN explosion to study the X-ray spectrum of SN 2011dh. We extracted spectra from the XMM-Newton observations, which took place ~7 and 11 days after the SN. In addition, we created integrated Swift/XRT spectra of 3 to 10 days and 11 to 30 days. The spectra are well fitted with a power-law spectrum absorbed with Galactic foreground absorption. In addition, we find a harder spectral component in the first XMM-Newton spectrum taken at t ~ 7 d. This component is also detected in the first Swift spectrum of t = 3 - 10 d. While the persistent power-law component can be explained as inverse Compton emission from radio synchrotron emitting electrons, the harder component is most likely bremsstrahlung emission from the shocked stellar wind. Therefore, the harder X-ray emission that fades away after t ~ 10 d can be interpreted as emission from the shocked circumstellar wind of SN 2011dh.Comment: Accepted for publication as a Research Note in Astronomy and Astrophysic

    Modular classes of Poisson-Nijenhuis Lie algebroids

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    The modular vector field of a Poisson-Nijenhuis Lie algebroid AA is defined and we prove that, in case of non-degeneracy, this vector field defines a hierarchy of bi-Hamiltonian AA-vector fields. This hierarchy covers an integrable hierarchy on the base manifold, which may not have a Poisson-Nijenhuis structure.Comment: To appear in Letters in Mathematical Physic

    Human umbilical cord blood plasma as an alternative to animal sera for mesenchymal stromal cells in vitro expansion – A multicomponent metabolomic analysis

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    Mesenchymal Stromal cells (MSCs) have a potential role in cell-based therapies. Foetal bovine serum (FBS) is used to supplement the basal cell culture medium but presents several disadvantages and risks. Other alternatives have been studied, including human umbilical cord blood plasma (hUCBP), aiming at the development of xeno-free culturing protocols. A comparative characterization of multicomponent metabolic composition of hUCBP and commercial FBS based on Nuclear Magnetic Resonance (NMR) spectroscopy and multivariate statistical analysis was performed. The analysis of 1H-NMR spectra revealed both similarities and differences between the two proposed supplements. Similar metabolites (amino acids, glucose, lipids and nucleotides) were found in the hUCBP and FBS NMR spectra. The results show that the major difference between the metabolic profiles of the two proposed supplements are due to the significantly higher levels of glucose and lower levels of lactate, glutamate, alanine and branched chain amino acids in hUCBP. Similar or slightly different levels of important proteinogenic amino acids, as well as of nucleotides, lipids were found in the hUCBP and FBS. In order to validate it’s suitability for cell culture, umbilical cord-MSCs (UC-MSCs) and dental pulp stem cells (DPSCs) were expanded using hUCBP. In both hMSCs, in vitro culture with hUCBP supplementation presented similar to improved metabolic performances when compared to FBS. The two cell types tested expressed different optimum hUCBP percentage content. For DPSCs, the optimum hUCBP content was 6% and for UC-MSCs, 4%. Cultured hMSCs displayed no changes in senescence indicators, as well as maintained characteristic surface marker’s expression. FBS substitution was associated with an increase in early apoptosis events, in a dose dependent manner, as well as to slight up- and down-regulation of targeted gene’s expression. Tri-lineage differentiation capacity was also influenced by the substitution of FBS by hUCBP.info:eu-repo/semantics/publishedVersio

    Algebraic Linearization of Dynamics of Calogero Type for any Coxeter Group

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    Calogero-Moser systems can be generalized for any root system (including the non-crystallographic cases). The algebraic linearization of the generalized Calogero-Moser systems and of their quadratic (resp. quartic) perturbations are discussed.Comment: LaTeX2e, 13 pages, no figure

    A novel approach in glioblastoma multiforme drug discovery: Perturbation studies in vitro

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    Despite impressive advances in drug discovery methods, predicting cellular response to anticancer drugs remains challenging. In glioblastoma multiforme, this fact is even marked as many promising drugs were followed by disappointment. As a result, the aim of this study is to clarify the effects of inhibition of 3-phosphoinositide-dependent protein kinase-1 (PDK1) in glioblastoma multiforme, while exploring how the focus on potency might ignore the potential impact of variation in other pharmacological parameters. The evaluation of the induced drug perturbation in glioblastoma cancer cells and a multiparametric characterization dose-response of two PDK1 inhibitors were performed. Singular analysis of potency would lead to the conclusion that FC100 compound would be the most promising to treat glioblastoma multiforme. However, exploring other pharmacological parameters shows the opposite giving more information about the cell response. The study shows that potency should not be the critical factor in developing new drugs as our most potent compound lacks growth inhibition effect. So, the evaluation of promising drugs during the drug discovery phase needs to be re-evaluated and multiparametric dose-response analysis might be a useful approach to compare drugs and potentially better characterization of both drug and disease profiles

    Dental pulp stem cells and Bonelike® for bone regeneration in ovine model

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    Development of synthetic bone substitutes has arisen as a major research interest in the need to find an alternative to autologous bone grafts. Using an ovine model, the present pre-clinical study presents a synthetic bone graft (Bonelike®) in combination with a cellular system as an alternative for the regeneration of non-critical defects. The association of biomaterials and cell-based therapies is a promising strategy for bone tissue engineering. Mesenchymal stem cells (MSCs) from human dental pulp have demonstrated both in vitro and in vivo to interact with diverse biomaterial systems and promote mineral deposition, aiming at the reconstruction of osseous defects. Moreover, these cells can be found and isolated from many species. Non-critical bone defects were treated with Bonelike® with or without MSCs obtained from the human dental pulp. Results showed that Bonelike® and MSCs treated defects showed improved bone regeneration compared with the defects treated with Bonelike® alone. Also, it was observed that the biomaterial matrix was reabsorbed and gradually replaced by new bone during the healing process. We therefore propose this combination as an efficient binomial strategy that promotes bone growth and vascularization in non-critical bone defects.This research was supported by Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER with the project ‘iBone Therapies: Terapias inovadoras para a regeneração óssea’, ref. NORTE-01-0247-FEDER-003262, and by the programme COMPETE – Programa Operacional Factores de Competitividade, Projects PEst-OE/AGR/UI0211/2011 and PEst-C/EME/UI0285/2013 funding from FCT. This research was also supported by Programa Operacional Competitividade e Internacionalizac¸~ao (P2020), Fundos Europeus Estruturais e de Investimento (FEEI) and FCT with the project ‘BioMate—A novel bio-manufacturing system to produce bioactive scaffolds for tissue engineering’ with reference PTDC/EMS-SIS/7032/2014 and by COMPETE 2020, from ANI—Projectos ID&T Empresas em Copromoção Programas Operacionais POCI, by the project ‘insitu.Biomas - Reinvent biomanufacturing systems by using an usability approach for in situ clinic temporary implants fabrication’ with the reference POCI-01-0247-FEDER-017771. The research was also supported by the research project ‘BEPIM III –Microdispositivos me´dicos com capacidades osteintegradoras por micoPIM’, with the reference POCI-01-0247-FEDER-017935, from Fundo Europeu de Desenvolvimento Regional (FEDER), by the Programa Operacional da Competitividade & Internacionalização. Ana Rita Caseiro (SFRH/BD/101174/2014) acknowledges FCT, for financial support

    Ecografia de Nervos Periféricos – Um Tutorial Guiado por Imagem para Iniciante

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    Avanços técnicos na ecografia facilitou de forma fiável a avaliação de pequenas estruturas.Atualmente, a avaliação de nervos periféricos depende ainda de dados clínicos suplementados por estudos eletrofisiológicos.A ultrassonografia pode ser aplicada na avaliação de patologia de nervos periféricos, contribuindo para o diagnóstico diferencial de patologias músculo-esqueléticas. O crescimento exponencial de publicações sobre esta temática nos últimos 10 anos foi fortemente fomentado pelo desenvolvimento de intervenção guiada por imagem, frequentemente utilizada em procedimentos analgésicos e anestésicos, tais como bloqueios nervosos. A Medicina da Dor é outro campo para a ecografia de nervos periféricos, onde a intervenção pode ser usada como forma de tratamento ou diagnóstico.A ecografia é uma técnica segura, embora fortemente dependente do utilizador, implicando firmes conhecimentos de anatomia.Elaborou-se uma revisão pictórica, assim como dos parâmetros e peculiaridades técnicas utilizadas para otimizar a imagem obtida. Serão demonstrados os marcos anatómicos mais frequentes e reconhecíveis no pescoço, membro superior, virilha, membro inferior, assim como a forma de colocação da sonda.Será efetuada uma breve revisão dos achados descritos em casos patológicos.Um firme conhecimento da ecografia dos nervos periféricos é um pré-requisito para os interessados na avaliação destes. O papel da intervenção guiada por ecografia tem evoluído no campo da anestesia e no campo da medicina da dor. Os radiologistas estão em excelente posição para relacionar a adequada técnica e o conhecimento anatómico, permitindo expandir o papel dos procedimentos guiados por imagem

    Rat olfactory mucosa mesenchymal stem/stromal cells (om-mscs): a characterization study

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    Stem/stromal cell-based therapies are a branch of regenerative medicine and stand as an attractive option to promote the repair of damaged or dysfunctional tissues and organs. Olfactory mucosa mesenchymal stem/stromal cells have been regarded as a promising tool in regenerative therapies because of their several favorable properties such as multipotency, high proliferation rate, helpful location, and few associated ethical issues. These cells are easily accessible in the nasal cavity of most mammals, including the rat, can be easily applied in autologous treatments, and do not cope with most of the obstacles associated with the use of other stem cells. Despite this, its application in preclinical trials and in both human and animal patients is still limited because of the small number of studies performed so far and to the nonexistence of a standard and unambiguous protocol for collection, isolation, and therapeutic application. In the present work a validation of a protocol for isolation, culture, expansion, freezing, and thawing of olfactory mucosa mesenchymal stem/stromal cells was performed, applied to the rat model, as well as a biological characterization of these cells. To investigate the therapeutic potential of OM-MSCs and their eventual safe application in preclinical trials, the main characteristics of OMSC stemness were addressed.info:eu-repo/semantics/publishedVersio
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