The Role of Inflammatory Markers in Predicting Resectability of Pancreatic Ductal Adenocarcinoma.

Background: Pancreatic adenocarcinoma is still considered as one of the most aggressive cancers with low percentages of respectability, despite recent advances in diagnosis. Assessment of preoperative inflammatory markers can increase the rates of resectability. Methods: Patients with potentially resectable pancreatic adenoinvesticarcinoma in a single pancreatic unit were included. Ninety-six patient during a one year period were eligible for analysis. Results: CRP, d-dimers, and fibrinogen levels were similar between the two groups. On the contrary, there were statistically significant differences regarding the prognostic nutritional index (PNI) and neutrophil-to-lymphocyte ratio (NLR). Conclusions: inflammatory markers can act as an additional tool in predicting resectability in patients with pancreatic adenocarcinoma.

Review of management options for pancreatic pseudocysts.

Pancreatic pseudocysts (PPs) present a challenging problem for physicians dealing with pancreatic disorders. Their management demands the co-operation of surgeons, radiologists and gastroenterologists. Historically, they have been treated either conservatively or surgically, with acceptable rates of complications and recurrence. However, recent advances in radiology and endoscopy, have leaded physicians to implement percutaneous and endoscopic drainage (ED) into their treatment algorithms. Moreover, laparoscopic surgery, with its advantages, has become an attractive alternative choice when surgical drainage (SD) is required. The aim of this review is to summarize the main diagnostic and therapeutic tools in the management of pseudocysts and to present the main studies that compare the three different types of pseudocyst drainage.

Measure of orbital stickiness and chaos strength.

Patterns can be used effectively to characterize dynamical orbits as regular or chaotic. The proposed method focuses on local, epochal characterization of orbits as opposed to global characterization usually employed by most established measures. The "patterns method" provides essentially a measure of chaos strength for every extremum of a signal. For this reason, it provides information about sticky epochs of chaotic orbits, as well as time-dependent orbits. This way it can be used to give extremely detailed pictures of the phase space of a system, as well as to provide characterizations early in the evolution of orbits. Moreover, the method applies generally; all that is required is a signal, of which an orbit is merely an example.

Chaotic collisionless evolution in galaxies and charged-particle beams.

Both galaxies and charged particle beams can exhibit collisionless evolution on surprisingly short time scales. This can be attributed to the dynamics of chaotic orbits. The chaos is often triggered by resonance caused by time dependence in the bulk potential, which acts almost identically for attractive gravitational forces and repulsive electrostatic forces. The similarity suggests that many physical processes at work in galaxies, although inaccessible to direct controlled experiments, can be tested indirectly via controlled experiments with charged particle beams, such as those envisioned for the University of Maryland electron ring currently nearing completion.

Characterization of chaos: a new, fast, and effective measure.

A new technique for characterization of the regular or chaotic nature of dynamical orbits has been discovered. It takes advantage of morphological and dynamical properties of orbits, and is very effective, at least for time-independent systems with two degrees of freedom. The new technique was initially designed with time-dependent and N-body systems in mind. For this reason one of its main goals is to provide straightforward information about the transient chaos associated with such regimes. Equally important is the distinction it can provide between sticky and wildly chaotic epochs during the evolution of chaotic orbits. The most important advantage over the existing methods is that it can characterize an orbit using a very small number of orbital periods. For these reasons the new method is extremely promising to be useful and effective in a broad spectrum of disciplines.

Fluctuations do matter: large noise-enhanced halos in charged-particle beams.

The formation of beam halos has customarily been described in terms of a particle-core model in which the space-charge field of the oscillating core drives particles to large amplitudes. This model involves parametric resonance and predicts a hard upper bound to the orbital amplitude of the halo particles. We show that the presence of colored noise due to space-charge fluctuations and/or machine imperfections can eject particles to much larger amplitudes than would be inferred from parametric resonance alone.

Chaos and the continuum limit in the gravitational N-body problem. II. Nonintegrable potentials.

This paper continues a numerical investigation of the statistical properties of "frozen-N orbits," i.e., orbits evolved in frozen, time-independent N-body realizations of smooth density distributions rho corresponding to both integrable and nonintegrable potentials, allowing for 10(2.5)10(3)-10(4), clear distinctions exist between the phase mixing of initially localized ensembles, which, in the continuum limit, exhibit regular versus chaotic behavior. Regular ensembles evolved in a frozen-N density distribution diverge as a power law in time, albeit more rapidly than ensembles evolved in the smooth distribution. Chaotic ensembles diverge in a fashion that is roughly exponential, albeit at a larger rate than that associated with the exponential divergence of the same ensemble evolved in smooth rho. For both regular and chaotic ensembles, finite-N effects are well mimicked, both qualitatively and quantitatively, by energy-conserving white noise with amplitude eta proportional, variant 1/N. This suggests strongly that earlier investigations of the effects of low amplitude noise on phase space transport in smooth potentials are directly relevant to real physical systems.

Chaos, ergodicity, and the thermodynamics of lower-dimensional time-independent Hamiltonian systems.

This paper uses the assumptions of ergodicity and a microcanonical distribution to compute estimates of the largest Lyapunov exponents in lower-dimensional Hamiltonian systems. That the resulting estimates are in reasonable agreement with the actual values computed numerically corroborates the intuition that chaos in such systems can be understood as arising generically from a parametric instability and that this instability may be modeled by a stochastic-oscillator equation [cf. Casetti, Clementi, and Pettini, Phys. Rev. E 54, 5969 (1996)], linearized perturbations of a chaotic orbit satisfying a harmonic-oscillator equation with a randomly varying frequency.