49 research outputs found

    Neutron scattering experiments and simulations near the magnetic percolation threshold of Fe_x Zn_{1-x} F_2

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    The low temperature excitations in the anisotropic antiferromagnetic Fe_{1-x} Zn_x F_2 for x=0.25 and 0.31, at and just above the magnetic percolation threshold concentration x_p=0.25, were measured using inelastic neutron scattering. The excitations were simulated for x=0.31 using a localized, classical excitation model, which accounts well for the energies and relative intensities of the excitations observed in the scattering experiments.Comment: 6 pages, 6 figure

    Gene expression analyses determine two different subpopulations in KIT-negative GIST-like (KNGL) patients

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    Introduction: There are limited findings available on KIT-negative GIST-like (KNGL) population. Also, KIT expression may be post-transcriptionally regulated by miRNA221 and miRNA222. Hence, the aim of this study is to characterize KNGL population, by differential gene expression, and to analyze miRNA221/222 expression and their prognostic value in KNGL patients. Methods: KIT, PDGFRA, DOG1, IGF1R, MIR221 and MIR222 expression levels were determined by qRT-PCR. We also analyzed KIT and PDGFRA mutations, DOG1 expression, by immunohistochemistry, along with clinical and pathological data. Disease-free survival (DFS) and overall survival (OS) differences were calculated using Log-rank test. Results: Hierarchical cluster analyses from gene expression data identified two groups: group I had KIT, DOG1 and PDGFRA overexpression and IGF1R underexpression and group II had overexpression of IGF1R and low expression of KIT, DOG1 and PDGFRA. Group II had a significant worse OS (p = 0.013) in all the series, and showed a tendency for worse OS (p = 0.11), when analyzed only the localized cases. MiRNA222 expression was significantly lower in a control subset of KIT-positive GIST (p < 0.001). OS was significantly worse in KNGL cases with higher expression of MIR221 (p = 0.028) or MIR222 (p = 0.014). Conclusions: We identified two distinct KNGL subsets, with a different prognostic value. Increased levels of miRNA221/222, which are associated with worse OS, could explain the absence of KIT protein expression of most KNGL tumors

    Nonlinear smith-predictor based control strategy for a unicycle mobile robot subject to transport delay

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    This paper consider the remote control of an unicycle mobile robot subject to transport delay. The communication delay effects are considered by means of a discrete time approach that allows to solve the path tracking problem in terms of the delayed input. The causality problem involved in the proposed solution is carried out by considering an extension to the nonlinear case of the well known Smith predictor compensator that allows the implementation of the noncausal feedback. The performance of the tracking strategy is evaluated by means of numerical simulations. ©2008 IEEE

    Acceso por intra-internet a grandes repositorios de imágenes de satélite, aplicación a ortoimágenes de la cuenca del Ebro

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    En este trabajo se aborda el problema de visualizar grandes repositorios de imágenes de satélite a través de una red, ya sea una intranet o Internet. Los problemas vienen dados por las limitaciones a la velocidad de transferencia de datos impuestas por la red, lo que conlleva importantes limitaciones al tamaño de la información a transmitir. Este artículo presenta una aproximación (asequible tecnológicamente y libre formatos propietarios y licencias) desarrollada en Java y basada en estándares que hace viable el acceso interactivo, con las herramientas básicas de un sistema de visualización de información geográfica, a este tipo de grandes repositorios así como la integración de coberturas vectoriales con éstas. La viabilidad de la aproximación propuesta queda demostrada con un ejemplo de implantación en la Confederación Hidrográfica del Ebro para el acceso a las ortoimágenes de la cuenca del Ebr

    SEOM Clinical Guideline of management of soft-tissue sarcoma (2016).

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    Soft-tissue sarcomas are uncommon and heterogeneous tumors of mesenchymal origin. A soft-tissue mass that is increasing in size, greater than 5 cm, or located under deep fascia are criteria for suspicion of sarcoma. Diagnosis, treatment, and management should preferably be performed by a multidisciplinary team in reference centers. MRI and lung CT scan are mandatory for local and distant assessment. A biopsy indicating histological type and grade is needed previous to the treatment. Wide surgical resection with tumor-free tissue margin is the primary treatment for localized disease. Radiotherapy is indicated in large, deep, high-grade tumors, or after marginal resection not likely of being improved with reexcision. Neoadjuvant and adjuvant chemotherapy improve survival in selected cases, usually in high-grade sarcomas of the extremities. In the case of metastatic disease, patients with exclusive lung metastasis could be considered for surgery. First-line treatment with anthracyclines (or in combination with ifosfamide) is the treatment of choice. New drugs have shown activity in second-line therapy and in specific histological subtypes

    Malignant bone tumors (other than Ewing's) : clinical practice guidelines for diagnosis, treatment and follow-up by Spanish Group for Research on Sarcomas (GEIS)

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    Primary malignant bone tumors are uncommon and heterogeneous malignancies. This document is a guideline developed by the Spanish Group for Research on Sarcoma with the participation of different specialists involved in the diagnosis and treatment of bone sarcomas. The aim is to provide practical recommendations with the intention of helping in the clinical decision-making process. The diagnosis and treatment of bone tumors requires a multidisciplinary approach, involving as a minimum pathologists, radiologists, surgeons, and radiation and medical oncologists. Early referral to a specialist center could improve patients' survival. The multidisciplinary management of osteosarcoma, chondrosarcoma, chordoma, giant cell tumor of bone and other rare bone tumors is reviewed in this guideline. Ewing's sarcoma will be the focus of a separate guideline because of its specific biological, clinical and therapeutic features. Each statement has been accompanied by the level of evidence and grade of recommendation on the basis of the available data. Surgical excision is the mainstay of treatment of a localized bone tumor, with various techniques available depending on the histologic type, grade and location of the tumor. Chemotherapy plays an important role in some chemosensitive subtypes (such as high-grade osteosarcoma). In other subtypes, historically considered chemoresistant (such as chordoma or giant cell tumor of bone), new targeted therapies have emerged recently, with a very significant efficacy in the case of denosumab. Radiation therapy is usually necessary in the treatment of chordoma and sometimes of other bone tumors

    NKG2D Polymorphism in Melanoma Patients from Southeastern Spain

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    Background: Natural killer (NK) and CD8+ T cells are involved in the immune response against melanoma. C-Type lectin-like NK cell receptors are located in the Natural Killer Complex (NKC) region 12p13.2-p12.3 and play a critical role in regulating the activity of NK and CD8+ T cells. An association between polymorphisms in the NKC region, including the NKG2D gene and NKG2A promoter, and the risk of cancer has been previously described. The aim of this study was to analyze the association of polymorphisms in the NKC region with cutaneous melanoma in patients from southeastern Spain. Methods: Seven single-nucleotide polymorphisms (SNPs) in the NKG2D gene (NKC3,4,7,9,10,11,12), and one SNP in the NKG2A promoter (NKC17) were genotyped by a TaqMan 5' Nuclease Assay in 233 melanoma patients and 200 matched healthy controls. Results: A linkage disequilibrium analysis of the SNPs performed in the NKC region revealed two blocks of haplotypes (Hb-1 and Hb-2) with 14 and seven different haplotype subtypes, respectively. The third most frequent haplotype from the block Hb-2-NK3 (CAT haplotype)-was significantly more frequent on melanoma patients than on healthy controls (p = 0.00009, Pc = 0.0006). No further associations were found when NKC SNPs were considered independently. Conclusions: Our results suggest an association between NKG2D polymorphisms and the risk of cutaneous malignant melanoma. Keywords: Melanoma; NK cell; NKG2A; NKG2D; gene polymorphism
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