754 research outputs found
INTERVENTI COMBINATI "COMPLETAMENTE ROBOTICI" CON IL SISTEMA DA VINCI XI: RESEZIONI COLO-RETTALI ASSOCIATE AD ALTRI INTERVENTI DI CHIRURGIA ADDOMINALE MAGGIORE: ASPETTI TECNICI E OUTCOME POST-OPERATORIO
No full textOBIETTIVI
La nuova piattaforma rilasciata dalla Intuitive, il Da Vinci Xi®, è stata sviluppata con l'intento di superare alcune limitazioni della precedente versione e in particolare facilitare il flusso di lavoro durante interventi multiquadrante. Nel presente studio vengono valutati gli aspetti tecnici e i risultati iniziali di resezioni colo-rettali combinate con altre procedure di chirurgia addominale maggiore eseguite con tecnica "completamente robotica" mediante l’ausilio del Da Vinci Xi.
MATERIALI E METODI
Dal Gennaio 2015 all’Ottobre 2015,10 pazienti sono stati sottoposti a chirurgia robotica colo-rettale combinata con altri interventi chirurgici intra-addominali presso il nostro centro. Le variabili esaminate sono state: caratteristiche demografiche, dati peri-operatori come disposizione dei trocar, aspetti tecnici, tempo operatorio e di docking ed aspetti di outcome precoci quali degenza media e complicanze chirurgiche post-operatorie. Le resezioni colo-rettali sono state cinque emicolectomie destre e cinque resezioni anteriori del retto associate a una sigmoidectomia, una nefrectomia destra, una isterectomia, tre resezioni epatiche, due enucleazioni di lesioni caudali del pancreas e una resezione ileo-colica. In tre casi è stato utilizzato il TruSystem 7000dV,specifico tavolo operatorio connesso al carrello paziente del Da Vinci Xi mediante tecnologia wireless che permette movimenti del paziente senza dover effettuare l'undocking o rimuovere gli strumenti robotici.
RISULTATI
Tutti gli interventi combinati sono stati eseguiti con tecnica “completamente robotica”, in assenza di conversione laparoscopica o laparotomica, necessità di approccio ibrido o di spostare il carrello paziente. La disposizione dei trocar rispecchia quella delle linee guida rilasciate direttamente dalla Intuitive per i quadranti addominali inferiori di sinistra. Per interventi simultanei nello stesso quadrante o per il quadrante di sinistra e la pelvi non è stato necessario nessun re-docking mentre per interventi su target chirurgici localizzati in emiaddomi opposti o per il quadrante di destra e la pelvi è stato necessario un doppio docking e re-targeting. Non sono stati registrati eventi di collisione esterna o problemi legati alla disposizione dei trocar. Il tempo operatorio medio è stato di 360 min (± 128 min) e la degenza media è stata di 6 giorni (± 3 giorni). Nel post-operatorio non sono state osservate complicanze chirurgiche o mediche.
CONCLUSIONI
La nostra iniziale esperienza suggerisce un alta percentuale di successo e fattibilità di interventi colo-rettali combinati con altri interventi per neoplasie sincrone eseguiti con approccio robotico. Il basso tasso di conversione, la manovrabilità sperimentata nel cambiare diversi target chirurgici conferma il vantaggio del nuovo prodotto Da Vinci Xi nella chirurgia multiquadrante. Ulteriori facilitazioni possono derivare dall' ingresso in commercio del nuovo tavolo operatorio integrato che permette i movimenti dello stesso senza la necessità di disconnettere il bracci robotici
Critical assessment of mean field models based on effective interactions
No full textMean field schemes, from simple Hartree–Fock plus random phase approximation calculations
of the ground and excited states to more sophisticated approaches which include pairing as well, have been
popular for quite a long time. In these models, the input is an effective interaction. We still lack a precise
link between this interaction and a more fundamental theory; however, there have been various new recent
attempts to correlate empirical pieces of evidence about nuclear (and neutron) matter, or experimental
results, with the properties of the effective interactions. In this contribution, we claim that, while we have
indeed made some progress in our understanding of certain features of the interactions, we are still missing
a clue about its proper density dependence and about its isovector properties
Nuclear density functional theory
No full textThe goal of nuclear structure physics is to provide a complete understanding of the static properties of atomic nuclei, their excitation spectra, their response to external fields and their decays. While it is hard to achieve these goals within a single framework, so that there is no nuclear 'standard model', it is clear that nuclear Density Functional Theory (DFT) has probably the widest range of applicability so far. In this paper, we try to put DFT in a broader context, with frequent comparisons to electronic DFT. We also include a discussion of the relationships with ab initio methods and Effective Field Theories (EFTs) in general, as well as a short survey of the quite large number of applications. Although written with a personal and possibly biased perspective, the paper aims at fostering cross-fertilizations with other domains of science
Heavy nuclei : Introduction to density functional theory and variations on the theme⋆
No full textDensity Functional Theory (DFT) is based on the rigorous Hohenberg-Kohn (HK) theorem, that has been first introduced for electronic systems but holds for all fermionic systems including atomic nuclei. Currently, DFT has reached a high level of sophistication, and represents a suitable tool for a self-consistent, quantitative description of bulk nuclear properties (like masses, radii and deformations) of all nuclei except, perhaps, the lightest ones. Furthermore, time-dependent calculations within the same framework account for the observed properties of several different types of nuclear collective motion. In this paper, we introduce these topics by assuming only a previous knowledge of general quantum mechanics and of basic nuclear phenomenology (we actually review some parts of it)
Constraints, limits and extensions for nuclear energy density functionals
No full textIn the present contribution, we discuss the behavior of Skyrme forces when they are employed to study both neutron stars and giant resonance states in 208Pb within the fully self-consistent Random Phase Approximation (RPA). We point out that clear correlations exist between the results for the isoscalar monopole and isovector dipole resonances (ISGMR and IVGDR), and definite quantities which characterize the equation of state (EOS) of uniform matter. We propose that the RPA results or, to some extent, the mentioned EOS parameters, are used as constraints when a force is fitted. This suggestion can be valid also when the fit of a more general energy density functional is envisaged. We use our considerations to select a limited number of Skyrme forces (10) out of a large sample of 78 interactions
Docking of Hydroxamic Acids into HDAC1 and HDAC8: A Rationalization of Activity Trends and Selectivities
No full textSynthesis, characterization and evaluation of thiolated quaternary ammonium-chitosan conjugates for enhanced intestinal drug permeation
No full textn a previous report quaternary ammonium-chitosan conjugates (N+-Chs) endowed with intestinal drug permeability-enhancing properties were described. They are characterized by short pendant chains of n adjacent diethyl-dimethylene-ammonium groups substituted onto the primary amino group of the chitosan (Ch) repeating units. In the present work two N+-Chs, one having DS (degree of substitution) = 59.2 ± 4.5%, n = 1.7 ± 0.1 (N+(60)-Ch), the other one having DS = 40.6 ± 1.3%, n = 3.0 ± 0.2 (N+(40)-Ch) were used to synthesize novel multifunctional non-cytotoxic Ch derivatives, each carrying thiol along with quaternary ammonium groups (N+-Ch-SH), with increased potential to enhance transepithelial drug transport. They have been obtained by transforming the residual free amino groups of N+(60)-Ch and N+(40)-Ch into 3-mercaptopropionamide moieties. The former yielded 4.5 ± 0.7% thiol-bearing groups, the latter, 5.2 ± 1.1% of such groups, on a Ch repeating unit basis. The multifunctional derivatives have improved the ability of the parent N+-Chs to enhance the permeability of the water-soluble macromolecular fluorescein isothiocyanate dextran, MW 4400 Da (FD4) and that of the lipophilic dexamethasone (DMS) across the excised rat intestinal mucosa and Caco-2 cell monolayer, respectively. The data from the present work altogether point to a synergism of quaternary ammonium and thiol groups to improve the intestinal drug absorption enhancing properties of the multifunctional Ch derivatives
Gel-forming mucoadhesive erodible ocular inserts for transcorneal controlled delivery of oflxacin
No full textThe compression modes in atomic nuclei and their relevance for the nuclear equation of state
No full textAccurate assessment of the value of the incompressibility coefficient, K-infinity of symmetric nuclear matter, which is directly related to the curvature of the equation of state (EOS), is needed to extend our knowledge of the EOS in the vicinity of the saturation point. We review the current status of K-infinity as determined from experimental data on isoscalar giant monopole and dipole resonances (compression modes) in nuclei by employing the microscopic theory based on the Random Phase Approximation (RPA). The importance of full self-consistent calculations is emphasized. In recent years, a comparision between RPA calculations based on either non-relativistic effective interactions or relativistic Lagrangians has been pursued in great detail. It has been pointed out that these two types of models embed different ansatz for the density dependence of the symmetry energy. This fact has consequences on the extraction of the nuclear incompressibility, as it is discussed. The comparison with other ways of extracting K-infinity from experimental data is highlighted
The symmetry energy and other open questions concerning effective functionals
No full textThe nuclear structure community is striving to determine a nuclear energy functional which is as universal and as accurate as possible. When a functional is determined by fitting free parameters, the constraints on these parameters coming from excited states (like the well-known giant resonances) are not, as a rule, imposed. This work shows that at least three constraints could be imposed on Skyrme functionals, by explaining the physical background and discussing their relevance
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