189 research outputs found

    A recursive coupling-decoupling approach to improve experimental frequency based substructuring results

    Get PDF
    Substructure decoupling techniques allow identifying the dynamic behavior of a substructure starting from the dynamic behavior or the assembled system and a residual subsystem. Standard approaches rely on the knowledge of all FRFs at the interface DOFs between the two substructures. However, as these typically include also rotational DOFs which are extremely difficult and most of the time impossible to measure, several techniques have been investigated to overcome these limitations. A very attractive solution consists in defining mixed or pseudo interfaces, that allow to substitute unmeasurable coupling DOFs with internal DOFs on the residual substructure. Additionally, smoothing/denoising techniques have been proposed to reduce the detrimental effect of FRF noise and inconsistencies on the decoupling results. Starting from these results, some recent analysis on the possibility of combining coupling and decoupling FBS to validate the results and compensate for inconsistencies will be presented in this paper. The proposed method relies on errors introduced in the substructuring process when assuming that the interface behaves rigidly, while it is generally known that this assumption is seldom verified. Consequently, a recursive coupling-decoupling approach will be used to improve the estimation of the dynamic response of either the residual structure (for decoupling) or the assembly (for coupling). The method, validated on analytical data, will be here analyzed on a numerical example inspired by an experimental campaign used to validate the finite element models and on which standard substructuring techniques showed some limitations. The results discussed in this paper will be then used as guidelines to apply the proposed methodologies on experimental data in the future

    What are Students Learning?: Assessing Service Learning and the Curriculum

    Get PDF
    Service learning, a method of learning and teaching, has the potential to move our educational system into the 21st century by providing a vehicle for integrating the needs of schools and communities while reflecting current reform agendas and providing meaningful learning experiences for students. In order for service learning to play a role in the transformation of our schools, however, educators must become successful at linking service to learning- making connections between service experiences and academic learning explicit. This paper explores the meaning of learning in service learning by explicating: a) how service learning links to current standards based reform agendas and; b) how the academic learning associated with service learning can be assessed by teachers, professors, and community agency personnel

    Can the new and old drugs exert an immunomodulatory effect in acute myeloid leukemia?

    Get PDF
    Acute myeloid leukemia (AML) is considered an immune-suppressive neoplasm capable of evading immune surveillance through cellular and environmental players. Increasing knowledge of the immune system (IS) status at diagnosis seems to suggest ever more attention of the crosstalk between the leukemic clone and its immunologic counterpart. During the last years, the advent of novel immunotherapeutic strategies has revealed the importance of immune dysregulation and suppression for leukemia fitness. Considering all these premises, we reviewed the “off-target” effects on the IS of different drugs used in the treatment of AML, focusing on the main advantages of this interaction. The data reported support the idea that a successful therapeutic strategy should consider tailored approaches for performing leukemia eradication by both direct blasts killing and the engagement of the IS

    Inside the biology of early T-cell precursor acute lymphoblastic leukemia: the perfect trick

    Get PDF
    Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a rare, distinct subtype of T-ALL characterized by genomic instability, a dismal prognosis and refractoriness to standard chemotherapy. Since its first description in 2009, the expanding knowledge of its intricate biology has led to the definition of a stem cell leukemia with a combined lymphoid-myeloid potential: the perfect trick. Several studies in the last decade aimed to better characterize this new disease, but it was recognized as a distinct entity only in 2016. We review current insights into the biology of ETP-ALL and discuss the pathogenesis, genomic features and their impact on the clinical course in the precision medicine era today

    Nanopore Sequencing in Blood Diseases: A Wide Range of Opportunities

    Get PDF
    The molecular pathogenesis of hematological diseases is often driven by genetic and epigenetic alterations. Next-generation sequencing has considerably increased our genomic knowledge of these disorders becoming ever more widespread in clinical practice. In 2012 Oxford Nanopore Technologies (ONT) released the MinION, the first long-read nanopore-based sequencer, overcoming the main limits of short-reads sequences generation. In the last years, several nanopore sequencing approaches have been performed in various “-omic” sciences; this review focuses on the challenge to introduce ONT devices in the hematological field, showing advantages, disadvantages and future perspectives of this technology in the precision medicine era

    FLT3 mutational analysis in acute myeloid leukemia: Advantages and pitfalls with different approaches

    Get PDF
    FMS-like tyrosine kinase 3 (FLT3) is one of the most closely studied genes in blood diseases. Numerous methods have been adopted for analyses, mainly in acute myeloid leukemia (AML) diagnostic work-up. According to international recommendations, the current gold standard approach allows FLT3 canonical mutations to be investigated, providing the main information for risk assessment and treatment choice. However, the technological improvements of the last decade have permitted “black side” gene exploration, revealing numerous hidden aspects of its role in leukemogenesis. The advent of the next-generation sequencing era emphasizes lights and shadows of FLT3 conventional mutational analysis, highlighting the need for a more comprehensive study of the gene. However, more extensive analysis is opening new, unexplored questions whose impact on clinical outcomes is still unknown. The present work is focused on the main topics regarding FLT3 mutational analysis in AML, debating the strengths and weaknesses of the current gold standard approach. The rights and wrongs of NGS introduction in clinical practice will be discussed, showing that a more extensive knowledge of FLT3 mutational status could lead to reconsidering its role in AML management

    IN VIVO EVALUATION OF PERIODONTAL MICROCIRCULATORY CHANGES ASSOCIATED WITH ENDODONTIC TREATMENT

    Get PDF
    The purpose of this study was to investigate in vivo the gingival microcirculatory changes associated with endodontic treatment using the continuous wave of condensation technique. MATERIALS AND METHODS: Twenty necrotic one canal roots of 20 cooperative patients of both sexes, aged between 20 and 43 years, were selected. All patients were examined by capillaroscopy before, immediately after endodontic treatment, and after 7 days. The last examination was carried out by the same operator, and repeated twice for each examined area: masticatory, buccal and labial mucosa corresponding to the endodontically treated root. All canals were prepared using a simultaneous technique with Ni-Ti files (MTwo files). RESULTS: The images of the masticatory mucosa after root canal obturation showed evident micro-areas of extravasation, with significant bleeding and angio-morphological alterations due to heat. One hour after the endodontic treatment evident extravasation was observed, but a decrease of all altered parameters, was present. After seven days from treatment, in the periodontal tissues, a complete healing was observed. The in vivo evaluation of the vascular pattern during root canal obturation with System B showed that the high temperature in the canal determines visible effects on the vasculature of adjacent sites. It was found that microangiotectonic alterations decrease up to a complete healing after 7 days from treatment. CONCLUSION: All the changes in microcirculation, due to thermal shock of periodontal tissues, are reversible

    ACTH-secreting neuroendocrine pancreatic tumor: a case report.

    Get PDF
    AbstractIntroductionIncidence of neuroendocrine tumor (NET) is increased in the last thirty years from 1.1 to 5.2 cases per 100,000 people in the United States. They can originate from the pancreatic gland and for the majority of cases are not functioning (80%). A small percentage of functioning may produce adrenocorticotropic hormone (ACTH) and lead to ectopic ACTH Syndrome (EAS), responsible of Cushing-Syndrome.ResultsWe present a case of a 30 year-old woman suffering from EAS due to a neoformation of the pancreatic tail of the maximum diameter of 4 cm. The lesion was resectable at preoperatory imaging. The patient was subjected to distal splenopancreasectomy. Histological examination showed a well-differentiated neuroendocrine carcinoma pT3N0. The postoperative course was regular. At two years of follow-up patient is almost completely asymptomatic for Cushing's but she has developed multiple liver metastases, for which she began chemotherapy.Discussionp-NET responsible for EAS is usually malignant and the radical treatment of excision of the lesion is not possible because they occur at the time of diagnosis with liver metastases or unresectable. Our patient had a mass at the time of diagnosis resectable but despite radical surgery, she has developed multiple liver metastases at two years and she was undergoing chemotherapy.ConclusionsIn agreement with previous literature we confirm the aggressive nature of pancreatic tumors secreting ACTH, despite radical surgery. Conversely, surgical treatment is effective on the resolution of clinical symptoms

    Trace elements in stomach oil of Scopoli's shearwater (Calonectris diomedea) from Linosa's colony

    Get PDF
    Calonectris diomedea is a colonial Procellariiform breeding on Mediterranean islands. The stomach oil produced during chick rearing is a peculiar trait of this species. The composition of the stomach oil is likely to reflect the composition of the prey ingested and might reveal the contaminants uptake with prey becoming a possible tool for the marine pollution monitoring. We examined the concentration of 15 trace elements by ICP-MS and direct mercury analyser. The principal component analysis revealed a heterogeneous pattern of metal concentration, showing a significant separation between samples collected 20 and 70 days after hatching. The data obtained in this work give preliminary information on the feeding habits and breeding ecology of Linosa's colony of Scopoli's shearwater. The trace metals variability found suggest that the stomach oil may have a role as trophic markers to understand predator-prey relationships and to have evidence on the accumulation of pollutants in the latter
    • …
    corecore