767 research outputs found
Effect of sodium hyluronate added to topical corticosteroids in chronic rhinosinusitis with nasal polyposis
Available medical treatments for chronic rhinosinusitis (CRS) with nasal polyposis (CRSwNP) comprise systemic and topical therapies. Although topical corticosteroids are effective in the treatment of CRS, they are not completely devoid of adverse effects. Thus, care has to be taken when long-term treatments are prescribed. There is recent evidence that sodium hyaluronate (SH), the major component of many extracellular matrices, promotes tissue healing, including activation and moderation of the inflammatory responses, cell proliferation, migration, and angiogenesis
INQUADRAMENTO CLINICO E MANAGEMENT DELLO SCHWANNOMA ESCLUSIVAMENTE INTRALABIRINTICO
Lo schwannoma intralabirintico (SIL) è un raro tumore benigno (prevalenza 0.1-0.4%) che origina dalle cellule di Schwann situate a ridosso della giunzione cito-neurale dell’VIII n.c. I sintomi clinici includono ipoacusia neurosensoriale monolaterale progressiva (95%), acufeni (51%), disequilibrio (35%), vertigine (22%), fullness (2%). Alla risonanza magnetica (RM) il tumore si presenta come una massa circoscritta, iperintensa in T1, ipointensa in T2 e con enhancement dopo gadolinio nelle immagini T1-pesate. Il management prevede in prima istanza osservazioni seriali con RM “wait and scan approach”. La chirurgia, considerando le complicanze descritte quali anacusia (100%), paralisi VII n.c. (4%), fistola liquorale (5.4%), meningite (1.8%), è riservata a casi limitati e dipende da: età, condizioni generali del paziente, sede e dimensioni del tumore ed è consigliabile in caso di un pattern di crescita invasivo e presenza di sintomi vertiginosi non responsivi al trattamento medico
Cholesteatoma vs granulation tissue: a differential diagnosis by DWI-MRI apparent diffusion coefficient
To diagnose cholesteatoma when it is not visible through tympanic perforation, imaging techniques are necessary. Recently, the combination of computed tomography and magnetic resonance imaging has proven effective to diagnose middle ear cholesteatoma. In particular, diffusion weighted images have integrated the conventional imaging for the qualitative assessment of cholesteatoma. Accordingly, the aim of this study was to obtain a quantitative analysis of cholesteatoma calculating the apparent diffusion coefficient value. So, we investigated whether it could differentiate cholesteatoma from other inflammatory tissues both in a preoperative and in a postoperative study
Mathematical model for preoperative identification of obstructed nasal subsites
The planning of experimental studies for evaluation of nasal airflow is particularly challenging given the difficulty in obtaining objective measurements in vivo. Although standard rhinomanometry and acoustic rhinometry are the most widely used diagnostic tools for evaluation of nasal airflow, they provide only a global measurement of nasal dynamics, without temporal or spatial details. Furthermore, the numerical simulation of nasal airflow as computational fluid dynamics technology is not validated. Unfortunately, to date, there are no available diagnostic tools to objectively evaluate the geometry of the nasal cavities and to measure nasal resistance and the degree of nasal obstruction, which is of utmost importance for surgical planning. To overcame these limitations, we developed a mathematical model based on Bernoulli's equation, which allows clinicians to obtain, with the use of a particular direct digital manometry, pressure measurements over time to identify which nasal subsite is obstructed. To the best of our knowledge, this is the first study to identify two limiting curves, one below and one above an average representative curve, describing the time dependence of the gauge pressure inside a single nostril. These upper and lower curves enclosed an area into which the airflow pattern of healthy individuals falls. In our opinion, this model may be useful to study each nasal subsite and to objectively evaluate the geometry and resistances of the nasal cavities, particularly in preoperative planning and follow-up
A Brief History of Singlefold Diophantine Definitions
Consider an (m + 1)-ary relation R over the set N of natural numbers. Does there exist an arithmetical formula ZΘ(a0, . . . , am, x1, . . . , xK), not involving universal quantifiers, negation, or implication, such that the representation and univocity conditions, viz., (Formula Presented) are met by each tuple (Formula Presented). A priori, the answer may depend on the richness of the language of arithmetic: Even if solely addition and multiplication operators (along with the equality relator and with positive integer constants) are adopted as primitive symbols of the arithmetical signature, the graph R of any primitive recursive function is representable; but can representability be reconciled with univocity without calling into play one extra operator designating either the dyadic operation [b, n]↠ b n or just the monadic function n ↠ b n associated with a fixed integer b > 1? As a preparatory step toward a hoped-for positive answer to this question, one may consider replacing the exponentiation operator by a dyadic relator designating an exponential-growth relation (a notion made explicit by Julia Bowman Robinson in 1952). We will discuss the said univocity, aka ‘single-fold-ness’, issue-first raised by Yuri V. Matiyasevich in 1974-, framing it in historical context. © 2023 Copyright for this paper by its authors
The Automation of Syllogistic II. Optimization and Complexity Issues
In the first paper of this series it was shown that any unquantified formula p in the collection MLSSF (multilevel syllogistic extended with the singleton operator and the predicate Finite) can be decomposed as a disjunction of set-theoretic formulae called syllogistic schemes. The syllogistic schemes are satisfiable and no two of them have a model in common, therefore the previous result already implied the decidability of the class MLSSF by simply checking if the set of syllogistic schemes associated with the given formula is empty. In the first section of this paper a new and improved searching algorithm for syllogistic schemes is introduced, based on a proof of existence of a 'minimum effort' scheme for any given satisfiable formula in MLSF. The algorithm addressed above can be piloted quite effectively even though it involves backtracking. In the second part of the paper, complexity issues are studied by showing that the class of ( 00)o1-simple prenex formulae (an extension of MLS) has a decision problem which is NP-complete. The decision algorithm that proves the membership of this decision problem to NP can be seen as a different decision algorithm for ML
Changing a semantics: opportunism or courage?
The generalized models for higher-order logics introduced by Leon Henkin, and
their multiple offspring over the years, have become a standard tool in many
areas of logic. Even so, discussion has persisted about their technical status,
and perhaps even their conceptual legitimacy. This paper gives a systematic
view of generalized model techniques, discusses what they mean in mathematical
and philosophical terms, and presents a few technical themes and results about
their role in algebraic representation, calibrating provability, lowering
complexity, understanding fixed-point logics, and achieving set-theoretic
absoluteness. We also show how thinking about Henkin's approach to semantics of
logical systems in this generality can yield new results, dispelling the
impression of adhocness. This paper is dedicated to Leon Henkin, a deep
logician who has changed the way we all work, while also being an always open,
modest, and encouraging colleague and friend.Comment: 27 pages. To appear in: The life and work of Leon Henkin: Essays on
his contributions (Studies in Universal Logic) eds: Manzano, M., Sain, I. and
Alonso, E., 201
Continued Hereditarily Finite Set-Approximations
We study an encoding RA that assigns a real number to each hereditarily finite set, in a broad sense. In particular, we investigate whether the map RA can be used to produce codes that approximate any positive real number to arbitrary precision, in a way that is related to continued fractions. This is an interesting question because it connects the theory of hereditarily finite sets to the theory of real numbers and continued fractions, which have important applications in number theory, analysis, and other fields
Defending the genome from the enemy within:mechanisms of retrotransposon suppression in the mouse germline
The viability of any species requires that the genome is kept stable as it is transmitted from generation to generation by the germ cells. One of the challenges to transgenerational genome stability is the potential mutagenic activity of transposable genetic elements, particularly retrotransposons. There are many different types of retrotransposon in mammalian genomes, and these target different points in germline development to amplify and integrate into new genomic locations. Germ cells, and their pluripotent developmental precursors, have evolved a variety of genome defence mechanisms that suppress retrotransposon activity and maintain genome stability across the generations. Here, we review recent advances in understanding how retrotransposon activity is suppressed in the mammalian germline, how genes involved in germline genome defence mechanisms are regulated, and the consequences of mutating these genome defence genes for the developing germline
Some decidability issues concerning C^n real functions
This paper adapts preexisting decision algorithms to a family RDF = {RDFn | n ∈ N} of languages regarding one-argument real functions; each RDFn is a quantifier-free theory about the differentiability class C^n, embodying a fragment of Tarskian elementary algebra. The limits of decidability are also highlighted, by pointing out that certain extensions of RDFn are undecidable. The possibility of extending RDFn into a language RDF∞ regarding the class C^∞, without disrupting decidability, is briefly discussed.
Two sorts of individual variables, namely real variables and function variables, are available in each RDFn. The former are used to construct terms and formulas that involve basic arithmetic operations and comparison relators between real terms, respectively. In contrast, terms designating functions involve function variables, constructs for addition of functions and scalar multiplication, and—outermost—i-th order differentiation D^i[ ] with i ⩽ n. An array of predicate symbols designate various relationships between functions, as well as function properties, that may hold over intervals of the real line; those are: function comparisons, strict and non-strict monotonicity / convexity / concavity, comparisons between a function (or one of its derivatives) and a real term.
The decidability of RDFn relies, on the one hand, on Tarski’s celebrated decision algorithm for the algebra of real numbers, and, on the other hand, on reduction and interpolation techniques. An interpolation method, specifically designed for the case n = 1, has been previously presented; another method, due to Carla Manni, can be used when n = 2. For larger values of n, further research on interpolation is envisaged
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