285 research outputs found

    Deep CNN for IIF Images Classification in Autoimmune Diagnostics

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    The diagnosis and monitoring of autoimmune diseases are very important problem in medicine. The most used test for this purpose is the antinuclear antibody (ANA) test. An indirect immunofluorescence (IIF) test performed by Human Epithelial type 2 (HEp-2) cells as substrate antigen is the most common methods to determine ANA. In this paper we present an automatic HEp-2 specimen system based on a convolutional neural network method able to classify IIF images. The system consists of a module for features extraction based on a pre-trained AlexNet network and a classification phase for the cell-pattern association using six support vector machines and a k-nearest neighbors classifier. The classification at the image-level was obtained by analyzing the pattern prevalence at cell-level. The layers of the pre-trained network and various system parameters were evaluated in order to optimize the process. This system has been developed and tested on the HEp-2 images indirect immunofluorescence images analysis (I3A) public database. To test the generalisation performance of the method, the leave-one-specimen-out procedure was used in this work. The performance analysis showed an accuracy of 96.4% and a mean class accuracy equal to 93.8%. The results have been evaluated comparing them with some of the most representative works using the same database

    Sedimentation of halloysite nanotubes from different deposits in aqueous media at variable ionic strengths

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    Halloysite clay is a natural nanomaterial that is attracting a growing interest in colloidal science. The halloysite aqueous dispersion stability is a key aspect for the configuration of a purification protocol as well as to establish the durability of a formulation. A physico-chemical study demonstrated the role of ionic strength and nanotube characteristic sizes on the sedimentation behavior. We highlighted the importance of the electrostatic repulsions exercised between the particles in the settling process. A protocol for image analysis has been proposed to provide robust information from time resolved optical images on the suspensions. In conclusion, we managed to correlate microscopic aspect to the peculiar sedimentation process of halloysite nanotubes

    Superconformal Algebras and Mock Theta Functions

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    It is known that characters of BPS representations of extended superconformal algebras do not have good modular properties due to extra singular vectors coming from the BPS condition. In order to improve their modular properties we apply the method of Zwegers which has recently been developed to analyze modular properties of mock theta functions. We consider the case of N=4 superconformal algebra at general levels and obtain the decomposition of characters of BPS representations into a sum of simple Jacobi forms and an infinite series of non-BPS representations. We apply our method to study elliptic genera of hyper-Kahler manifolds in higher dimensions. In particular we determine the elliptic genera in the case of complex 4 dimensions of the Hilbert scheme of points on K3 surfaces K^{[2]} and complex tori A^{[[3]]}.Comment: 28 page

    Mitochondrion at the Crossroad Between Nutrients and Epigenome.

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    Epigenetic profile is the link between the regulation of nuclear gene expression and the environment. The most important factors capable of significantly affecting the cellular environment are the amount and quality of nutrients available. Mitochondria are both involved in the production of some of the molecules capable of directly affecting the epigenome and have a critical role in the conversion of nutrients into usable energy. Carbohydrate and fats are converted into ATP, acetyl-CoA, SAM, and NADH. These high-energy substrates are, in turn, capable of driving the epigenetic profile. We describe substances capable of affecting this mechanism. On the other hand, nutritional interventions capable of reducing calories or significantly impairing the normal Acetyl-CoA production or the SAM-SAH ratio also impact chromatin methylation and histone modification, suggesting a critical role of mitochondria on nutrient-dependent epigenetic profile

    Phenotypic Spectrum and Molecular Findings in 17 ATR-X Syndrome Italian Patients: Some New Insights

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    ATR-X syndrome is a rare X-linked congenital disorder caused by hypomorphic mutations in the ATRX gene. A typical phenotype is well defined, with cognitive impairment, characteristic facial dysmorphism, hypotonia, gastrointestinal, skeletal, urogenital, and hematological anomalies as characteristic features. With a few notable exceptions, general phenotypic differences related to specific ATRX protein domains are not well established and should not be used, at least at the present time, for prognostic purposes. The phenotypic spectrum and genotypic correlations are gradually broadening, mainly due to rapidly increasing accessibility to NGS. In this scenario, it is important to continue describing new patients, illustrating the mode and age of onset of the typical and non-typical features, the classical ones and those tentatively added more recently. This report of well-characterized and mostly unreported patients expands the ATR-X clinical spectrum and emphasizes the importance of better clinical delineation of the condition. We compare our findings to those of the largest ATR-X series reported so far, discussing possible explanations for the different drawn conclusions

    Longevity: Lesson from model organisms

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    Research on longevity and healthy aging promises to increase our lifespan and decrease the burden of degenerative diseases with important social and economic effects. Many aging theories have been proposed, and important aging pathways have been discovered. Model organisms have had a crucial role in this process because of their short lifespan, cheap maintenance, and manipulation possibilities. Yeasts, worms, fruit flies, or mammalian models such as mice, monkeys, and recently, dogs, have helped shed light on aging processes. Genes and molecular mechanisms that were found to be critical in simple eukaryotic cells and species have been confirmed in humans mainly by the functional analysis of mammalian orthologues. Here, we review conserved aging mechanisms discovered in different model systems that are implicated in human longevity as well and that could be the target of anti-aging interventions in human

    The accuracy of sentinel lymph-node biopsy in breast cancer after previous excisional biopsy

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    Scopo: La biopsia del linfonodo sentinella (BLS) nel carcinoma della mammella con linfonodi ascellari clinicamente negativi \ue8 considerato la migliore scelta per stadiare il cavo ascellare. Inizialmente una precedente biopsia escissionale del carcinoma era considerata una controindicazione. Esaminiamo il tasso di successo della BLS e la incidenza della recidiva a livello ascellare in pazienti con carcinoma della mammella precedentemente sottoposti a biopsia escissionale del tumore. Pazienti e metodi: 858 pazienti con carcinoma della mammella sono stati sottoposti a BLS e i pazienti con linfonodi sentinella metastatici a svuotamento del cavo ascellare; 82 pazienti erano stati sottoposti precedentemente a biopsia escissionale del tumore. Risultati: Il linfonodo sentinella \ue8 stato identificato nel 100% dei casi, \ue8 risultato indenne nel 74,4% e metastatico nel 23,1%. La dissezione del cavo ascellare \ue8 stata effettuata in tutti i casi con linfonodi sentinella metastatici e nel 74% dei casi non si sono ritrovati altri linfonodi ascellari metastatici. Il follow-up mediano \ue8 stato di 63,5 mesi e non si sono osservate recidive ascellari. Conclusioni: L\u2019accuratezza del BLS in pazienti con carcinoma della mammella sottoposte precedentemente a biopsia escissionale \ue8 uguale a quella dei pazienti non sottoposti a biopsia.Aim: Sentinel node biopsy (SLNB) is considered to be the standard of care for staging the axilla in clinically node-negative women with breast cancer. A previous breast excisional biopsy has been considered a contraindication to the use of SLNB.We examined the success rate of SLN localization and then the evaluation of the incidence of axillary relapse in patients with breast cancer undergoing excisional biopsy. Patients and Methods: 858 patients with breast carcinoma underwent a SLNB and only positive sentinel nodes were submitted to axillary dissection; 82 patients had undergone an excisional biopsy before. Results: The sentinel node was identified in 100% of cases, it was negative in 74.4% and positive in 23.1%. Complete axillary dissection was performed in all positive cases, and in 74% of cases no other positive nodes were found. The follow-up median was 63.5 months and no axillary recurrence was observed. Conclusions: SLNB accuracy in breast cancer patients who have previously undergone excisional biopsy is comparable with that in patients undergoing no excisional biopsy, so that it may be considered a standard procedure
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