589 research outputs found

    On a conjecture of Bennewitz, and the behaviour of the Titchmarsh-Weyl matrix near a pole

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    For any real limit-nn 2n2nth-order selfadjoint linear differential expression on [0,∞)[0,\infty), Titchmarsh- Weyl matrices M(λ)M(\lambda) can be defined. Two matrices of particu lar interest are the matrices MD(λ)M_D(\lambda) and MN(λ)M_N(\lambda) assoc iated respectively with Dirichlet and Neumann boundary conditions at x=0x=0. These satisfy MD(λ)=−MN(λ)−1M_D(\lambda) = -M_{N}(\lambda)^{-1}. It is known that when these matrices have poles (which can only lie on the real axis) the existence of valid HELP inequalities depends on their behaviour in the neighbourhood of these poles. We prove a conjecture of Bennewitz and use it, together with a new algorithm for computing the Laurent expansion of a Titchmarsh-Weyl matrix in the neighbourhood of a pole, to investigate the existence of HELP inequalities for a number of differential equations which have so far proved awkward to analys

    Thermal inertia of heavyweight traditional buildings: Experimental measurements and simulated scenarios

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    Abstract This paper discusses the results of an experimental campaign aimed to describe the thermal performance of a traditional building located in Catania, Southern Italy. The building was built in the early 1900s with traditional techniques and local materials, namely basalt stones, and is currently used for residential purposes. The results of the experimental campaign are exploited to calibrate a model for the dynamic simulation of the building with DesignBuilder. The calibrated model is then used to simulate how the same building would behave with a modern envelope made of a double leaf of bricks; other simulations take into account possible retrofit solutions, such as the installation of an insulating material either on the inner or the outer side of the walls, as well as the role of nighttime natural ventilation

    Clonal Chromosome Anomalies Affecting Fli1 Mimic Inherited Thrombocytopenia Of The Paris-Trousseau Type

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    Introduction: The thrombocytopenia of the Paris-Trousseau (TCPT) type is a contiguous gene syndrome characterized by mild bleeding tendency, variable thrombocytopenia (THC), abnormal giant alpha-granules in platelets and dysmegakaryopoiesis: it derives from a constitutional deletion of chromosome 11 leading to the loss of FLI1, a transcription factor involved in megakaryocyte differentiation and maturation. Case report: A women with an acquired, isolated THC developing over 10 yr showed morphological features typical of TCPT in platelets and bone marrow (BM). Twenty years after the onset of THC, the other hematological parameters are still normal and the patient is well. Results: Clonal hemopoiesis was shown and chromosome analyses performed on BM revealed a clone with 45 chromosomes and a complex unbalanced translocation involving chromosomes 2, 3, and 11. The anomaly was present in the majority of bone marrow cells but only in a few peripheral blood elements. A microarray-based comparative genomic hybridization defined the deleted region of chromosome 11 including the FLI1 locus that was missing. Conclusion: Although our patient presented with nearly all the characteristics of TCPT, her illness was acquired instead of being inherited and the most appropriate diagnosis is that of the unilineage dysplasia 'refractory THC.' This observation suggests that appropriate cytogenetic investigations should be always considered in patients with acquired THC of unknown origin

    Practical Approach to the Diagnosis of the Vulvo-Vaginal Stromal Tumors: An Overview

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    Background: The category of the "stromal tumors of the lower female genital tract" encompasses a wide spectrum of lesions with variable heterogeneity, which can be nosologically classified on the basis of their morphologic and immunohistochemical profiles as deep (aggressive) angiomyxoma (DAM), cellular angiofibroma (CAF), angiomyofibroblastoma (AMFB) or myofibroblastoma (MFB). Despite the differential diagnosis between these entities being usually straightforward, their increasingly recognized unusual morphological variants, along with the overlapping morphological and immunohistochemical features among these tumours, may raise serious differential diagnostic problems. Methods and Results: The data presented in the present paper have been retrieved from the entire published literature on the PubMed website about DAM, CAF, AFMB and MFB from 1984 to 2021. The selected articles are mainly represented by small-series, and, more rarely, single-case reports with unusual clinicopathologic features. The present review focuses on the diagnostic clues of the stromal tumours of the lower female genital tract to achieve a correct classification. The main clinicopathologic features of each single entity, emphasizing their differential diagnostic clues, are discussed and summarized in tables. Representative illustrations, including the unusual morphological variants, of each single tumour are also provided. Conclusion: Awareness by pathologists of the wide morphological and immunohistochemical spectrum exhibited by these tumours is crucial to achieve correct diagnoses and to avoid confusion with reactive conditions or other benign or malignant entities

    The safety of care focused on patient identity: an observational study

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    BACKGROUND AND AIM: Healthcare organizations, in order to reduce errors and extend the number of safe practices, are looking for possible solutions to enhance the clients' health quality care and trying to spread the culture of safety healthcare. Although in the literature the field of research "patient safety" is very debated, there are few empirical studies that investigate about the strategies undertaken by nursing students for the patients identification process during their care pathway. The aim of this study is to investigate the knowledge of the Ministerial Recommendation No. 3/2008 among nursing students, a specific Italian directive that aims to guarantee the safety of cares. METHODS: A four-weeks single-center observational study was conducted, involving a convenient sample of 112 students of the 2nd and 3rd  year of the Nursing Course Degree of the University of Parma. The survey was conducted using an ad-hoc questionnaire. RESULTS: The use of the identification wristband is considered one of the most important strategy to make sure the patient identification; unfortunately it is in practice used just in few occasions and only when performed specific procedures; it is furthermore noted that patients are not enough informed about the use and finalities of the identification wristband. CONCLUSIONS: Considering the importance of the patient identification process to guarantee the  safety of cares, the results produced, suggest that this investigation field deserves further insights in order to collect more substantial data and expand knowledge on the specific subject, so as to fill  knowledge gaps and sensitize nursing students to the correct use of the identification wristband

    Preventing corona effects: multi-phosphonic acid poly(ethylene glycol) copolymers for stable stealth iron oxide nanoparticles

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    When disperse in biological fluids, engineered nanoparticles are selectively coated with proteins, resulting in the formation of a protein corona. It is suggested that the protein corona is critical in regulating the conditions of entry into the cytoplasm of living cells. Recent reports describe this phenomenon as ubiquitous and independent of the nature of the particle. For nanomedicine applications however, there is a need to design advanced and cost-effective coatings that are resistant to protein adsorption and that increase the biodistribution in vivo. In this study, phosphonic acid poly(ethylene glycol) copolymers were synthesized and used to coat iron oxide particles. The copolymer composition was optimized to provide simple and scalable protocols as well as long-term stability in culture media. It is shown that polymers with multiple phosphonic acid functionalities and PEG chains outperform other types of coating, including ligands, polyelectrolytes and carboxylic acid functionalized PEG. PEGylated particles exhibit moreover exceptional low cellular uptake, of the order of 100 femtograms of iron per cell. The present approach demonstrates that the surface chemistry of engineered particles is a key parameter in the interactions with cells. It also opens up new avenues for the efficient functionalization of inorganic surfaces.Comment: 21 page, 7 figures,Biomacromolecules 201
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