33 research outputs found
Postoperative bleeding risk of direct oral anticoagulants after oral surgery procedures: a systematic review and meta-analysis
No full textDirect oral anticoagulants (dabigatran, rivaroxaban, apixaban and edoxaban; DOACs) have been introduced to improve safety and superior therapeutic value compared to their predecessors such as warfarin or enoxaparin. The aim of this systematic review and meta-analysis was to assess the postoperative bleeding risk of DOACs during oral surgery procedures. Systematic searches were performed in electronic databases including PubMed, Scopus, Web of Science and Cochrane Library. Thirteen studies were included in the qualitative synthesis: two retrospective case–control studies, five prospective case–control studies, three cross-sectional studies, two case series and a case report; while only six studies were statistically analysed. The risk ratio of postoperative bleeding in DOACs patients was significantly greater than in healthy patients (3.04; 95% confidence interval (CI) = 1.31–7.04). This is especially true for rivaroxaban (4.13; 95% CI = 1.25–13.69), and less so for dabigatran which presented a risk ratio similar to that of healthy patients (1.00; 95% CI = 0.21–4.82). However, further research is required to support these results. Both apixaban and edoxaban were excluded from statistical analysis due to the lack of clinical studies
On the utility and protection of optimization with differential privacy and classic regularization techniques
No full textNowadays, owners and developers of deep learning models must consider stringent privacy-preservation rules of their training data, usually crowd-sourced and retaining sensitive information. The most widely adopted method to enforce privacy guarantees of a deep learning model nowadays relies on optimization techniques enforcing differential privacy. According to the literature, this approach has proven to be a successful defence against several models’ privacy attacks, but its downside is a substantial degradation of the models’ performance. In this work, we compare the effectiveness of the differentially-private stochastic gradient descent (DP-SGD) algorithm against standard optimization practices with regularization techniques. We analyze the resulting models’ utility, training performance, and the effectiveness of membership inference and model inversion attacks against the learned models. Finally, we discuss differential privacy’s flaws and limits and empirically demonstrate the often superior privacy-preserving properties of dropout and l2-regularization
Quantum Bisimilarity via Barbs and Contexts: Curbing the Power of Non-deterministic Observers
No full textPast years have seen the development of a few proposals for quantum extensions of process calculi. The rationale is clear: with the development of quantum communication protocols, there is a need to abstract and focus on the basic features of quantum concurrent systems, like CCS and CSP have done for their classical counterparts. So far, though, no accepted standard has emerged, neither for the syntax nor for the behavioural semantics. Indeed, the various proposals do not agree on what should be the observational properties of quantum values, and as a matter of fact, the soundness of such properties has never been validated against the prescriptions of quantum theory. To this aim, we introduce a new calculus, Linear Quantum CCS (lqCCS), and investigate the features of behavioural equivalences based on barbs and contexts. Our calculus can be thought of as an asynchronous, linear version of qCCS, which is in turn based on value-passing CCS. The combination of linearity and asynchronous communication fits well with the properties of quantum systems (e.g. the no-cloning theorem), since it ensures that each qubit is sent exactly once, precisely specifying which qubits of a process interact with the context. We exploit contexts to examine how bisimilarities relate to quantum theory. We show that the observational power of general contexts is incompatible with quantum theory: roughly, they can perform non-deterministic moves depending on quantum values without measuring (hence perturbing) them. Therefore, we refine the operational semantics in order to prevent contexts from performing unfeasible non-deterministic choices. This induces a coarser bisimilarity that better fits the quantum setting: (i) it lifts the indistinguishability of quantum states to the distributions of processes and, despite the additional constraints, (ii) it preserves the expressiveness of non-deterministic choices based on classical information. To the best of our knowledge, our semantics is the first one that satisfies the two properties above
Systematic review of the literature on dental caries and periodontal disease in socio-economically disadvantaged individuals
No full textDental caries and periodontal disease represent a health problem and a social cost for the entire population, and in particular for socio-economically disadvantaged individuals who are less resistant to disease. The aim of this review is to estimate the prevalence and severity of the two dental pathologies, caries and periodontal disease, in the different classes of socio-economically disadvantaged subjects and to understand which of them are most affected. A systematic search of the literature was performed in MEDLINE (via PubMed), EMBASE and Web of Science after establishing a suitable search strategy for each database, using keywords related to socio-economically vulnerable classes and health outcomes. Socio-economically disadvantaged individuals are more susceptible to tooth decay and periodontal disease (with relative tooth loss) than non-vulnerable people. Additionally, when multiple vulnerabilities are combined in the same subject, these oral diseases worsen. There is no type of vulnerability more affected by caries and periodontitis than others, since overall they all have severe disease indices. The data from this systematic literature review might be useful for health policy makers looking to allocate more resources and services to socially disadvantaged individuals, resulting in making them more resilient to oral disease due to their social marginalization
Efficacia di un flow nel gradino cervicale delle II Classi. Analisi sperimentale Effects of a flowable composite on the cervical margin in class II restorations. Experimental analysis
No full textObiettivi. Lo scopo di questo lavoro è stato valutare l’effetto dell’utilizzo, a livello del gradino cervicale smalteo delle cavità di II Classe, i compositi fluidi (tecnica “open sandwich”) rispetto al più tradizionale uso dei soli compositi microibridi, in modo da verificare sperimentalmente se esistano differenze che possano indurre gli operatori a preferire una delle due tecniche.
Materiali e metodi. Sono stati selezionati 15 elementi posteriori estratti, in cui sono state preparate cavità mesio-occluso-distali (MOD), con gradino cervicale tenuto sempre nello smalto, applicando poi mordenzante e adesivo sui tessuti dentali. Polimerizzato lo strato unico di primer-bonding e inserita la matrice, è stato applicato il flow (1 mm) su 15 dei 30 gradini; tutte le cavità sono state poi riempite con un composito tradizionale mediante tecnica incrementale e ogni strato è stato adeguatamente polimerizzato. I campioni così ottenuti sono stati in seguito termociclati in bagni alternati a 5 °C e 55 °C per 1.000 cicli, sezionati in senso assiale, osservati al microscopio elettronico a scansione (SEM) per individuare la presenza di gap a livello del margine cervicale.
Risultati. I risultati ottenuti consistono in una serie di 150 foto al SEM che hanno permesso la valutazione comparativa dell’integrità marginale, a livello dei gradini cervicali, del composito e del flow. Appare non esistere una differenza, dal punto di vista dell’utilizzo clinico, tra l’uso diretto di composito tradizionale e l’uso di composito flow in associazione al composito tradizionale, a livello del gradino cervicale di II Classe tagliato in smalto, poiché le 15 coppie di campioni non hanno presentato, in alcun caso, gap tra smalto e ricostruzione.
Conclusioni. La presente ricerca depone per la completa intercambiabilità nell’utilizzo clinico dei compositi fluidi (tecnica open sandwich) o dei compositi tradizionali a livello del gradino cervicale smalteo delle II Classi
Testing Quantum Processes
No full textThe recent development of quantum communication protocols calls for adequate modelling and verification techniques, which requires abstracting and focusing on the basic features of quantum concurrent systems. Several quantum process calculi and behavioural equivalences have been proposed to address this problem, but they are often incompatible with the prescriptions of quantum theory, as they implicitly define omniscient observers that are capable of exactly discriminating the state of a physical system, therefore contradicting the uncertainty principle. In this paper, we directly model these observational limitations by resorting to testing equivalence for a quantum capable version of CCS, building on the concrete actions and experiments that a real tester can perform. Thus, we obtain an equivalence notion pairing processes that cannot be distinguished by any physically implementable observer
Aspetti microstrutturali della dentina nella fluorosi grave
No full textObjectives. Although fluoride is important for the healthy development of enamel tissue, its excess may produce dental fluorosis through still unknown mechanisms. Biochemical evidence suggests the participation of the underlying dentin to enamel fluorosis: in this paper, we examine the micromorphology of fluorotic dental tissues by Scanning Electronic Microscopy (SEM). The aim of the work is the identification of dentinal alterations corresponding to fluorotic plaques. Materials and Methods. Six teeth affected by fluorosis (scored “severe” according to 1942 the Dean’s classification) are fractures and their microstructures observed by Scanning Electronic Microscopy (SEM). Results. The microscopic images of enamel corresponding to fluorotic plates show important underlying dentinal modifications, consisting of marked tubular obliteration. On the contrary, the dentin lying beneath the “apparently normal” enamel does not show micromorphological alterations. Conclusions. Our data agree with recently reported findings on dentinal alterations in severe fluorosis and show that the tubular obliteration occurs only in the dentin underneath clinically altered enamel. The mechanism responsible for the dentinal sclerosis and the characters of this micromorphological fluorotic sclerosis need, however, for further investigation because the prevailing literature (although more dated) is inclined to the presence of dentinal hipomineralization (and not of ipermineralization) in cases of fluorosis
[Tests on ionic release from glass-ionomer cements].
No full textBACKGROUND:
Dissolution process in oral liquids by the presence of glass-ionomer systems (due to surface corrosion, to diffusion through solutions and through mass) make an ionic release (particularly F, Al, Pb, As) which is a non secondary problem, due to the usual utilization of these materials in pedodontic and restorative dentistry.
METHODS:
In this work, considering the high toxicity of low quantity of Arsenic ion, a comparative research has been made in order to determine, by using high level liquid Cromatography (HPCL), the quantity in ppm of As hydro- and acid soluble given by five ionomeric products, in water and in nitric acid concentrated solution.
RESULTS AND CONCLUSIONS:
The results show that in some products arsenical concentrations are higher then the quantity accepted by ISO-FDI; therefore, a better control in the production of these products is needed as well as a limited use in dentistry. It is suggested to use glass-ionomer systems in patients with dental dike and varnish on the surfaces that are in contact with oral liquids action
Two Steps Forward and One Behind: Rethinking Time Series Forecasting with Deep Learning
No full textThe Transformer is a highly successful deep learning model that has revolutionised the world of artificial neural networks, first in natural language processing and later in computer vision. This model is based on the attention mechanism and is able to capture complex semantic relationships between a variety of patterns present in the input data. Precisely because of these characteristics, the Transformer has recently been exploited for time series forecasting problems, assuming a natural adaptability to the domain of continuous numerical series. Despite the acclaimed results in the literature, some works have raised doubts about the robustness and effectiveness of this approach. In this paper, we further investigate the effectiveness of Transformer-based models applied to the domain of time series forecasting, demonstrate their limitations, and propose a set of alternative models that are better performing and significantly less complex. In particular, we empirically show how simplifying Transformer-based forecasting models almost always leads to an improvement, reaching state of the art performance. We also propose shallow models without the attention mechanism, which compete with the overall state of the art in long time series forecasting, and demonstrate their ability to accurately predict time series over extremely long windows. From a methodological perspective, we show how it is always necessary to use a simple baseline to verify the effectiveness of proposed models, and finally, we conclude the paper with a reflection on recent research paths and the opportunity to follow trends and hypes even where it may not be necessary
Autism spectrum disorder and paediatric dentistry: A narrative overview of intervention strategy and introduction of an innovative technological intervention method
No full textAim When treating patients with Autism Spectrum Disorder (ASD) the doctor-patient relationship can be very challenging. The dentist is often forced to work under general anaesthesia or conscious sedation. Children with ASD are patients with an increased risk of caries due to poor oral hygiene, a cariogenic diet and the use of xerostomal drugs. In this work therapeutic strategies used to treat this kind of patients are evaluated and a new method to treat children with ASD is presented in order to increase awareness about this condition in the dental field. Methods The Atlas Center (a non-profit organisation in Peurgia, Italy) has developed a software, called paINTeraction, that allows these special children to immerse themselves in a virtual reality with the help of an operator. Through this system the child can explore the dental office (and all its sounds and noises) before the real dental visit, thus connecting to the dental professional, achieving greater compliance and reducing anxiety. Results The literature shows that performing treatments on ASD patients is complex due to their insufficient cooperation, communication and behavioural difficulties, and hypersensitivity to sensory stimuli. Conclusions paINTeraction, with the use of digital technology tools, may be particularly well suited to introduce patients to the therapeutic environment, particularly in the dental setting
