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Periodontal diseases ranges from simple gum inflammation to serious disease that consists in major damage to the soft tissue and bone teeth support. Periodontal diseases affects the marginal and apical periodontium and results from the interaction between bacterial biofilm and the host response. To determine the concentrations of MMP-8, as a disease marker, in saliva in prosthetic and nonprosthetic, aggressive (AP) and chronic (CP) periodontitis, doxycycline treated patients. 40 patients were distributed into 3 groups: 12 diagnosed with aggressive (AgP), 18 with chronic (CP) periodontitis. Each of these groups was subdivided into 2 subgroups with and without fixed prosthesis. 10 patients were in the normal group. Matrix metalloproteinase 8 (MMP-8) was evaluated before and after systemic doxycycline (Dox) treatment. mean MMP-8 value into the control group was 0.57 ng/mL with a standard deviation (STD) of 0,094 ng/mL. Highest MMP-8 value was established for the nonprosthesis AgP subgroup, before Dox treatment. The highest reduction in MMP-8 levels (40.8%) was between nonprosthesis AgP before Dox treatment and the same group after Doxycycline treamtent. MMP-8 saliva levels are lower than GCF levels, mostly through a dilution mechanism as previous studies had shown. Our study revealed that saliva MMP-8 level is relible marker for AgP but not for CP. Doxycycline treatment, in terms of lowering MMP-8 levels is most effective in patients that have AP and are also wearing fixed.

The objective of this work was to study the behavior of the azeotropic points of the methanol + DMC system under elevated pressures. We obtained isothermal vapor–liquid equilibria (VLE) data for this system at 383.15, 403.15, and 413.15 K by a static method. The azeotropic points were determined from the experimental VLE data. The temperature and pressure dependencies of the determined azeotropic points are discussed and compared with ones measured at reduced pressure. The experimental VLE data were represented by two activity coefficient models (non-random two-liquid and Wilson models). We also tested the modified UNIFAC (Dortmund) model for prediction of the VLE and azeotropic points. The azeotropic points of this system could be obtained over the pressure range from reduced pressures to elevated ones.

The coexistence of stable limit cycles and chaotic attractors has already been observed in some 3D dynamical systems. In this paper we show, using the T-system, that unstable limit cycles and chaotic attractors can also coexist. Moreover, by completing the characterization of the existence of invariant algebraic surfaces and their associated global dynamics, we give a better understanding on the disappearance of the strange attractor and the limit cycles of the studied system.

In this paper we analyze the motion of charged particles in a non-standard magnetic field that is of a Clebsch type representation where a magnetic perturbation is considered. The safety factor of ASDEX-Upgrade is used. Some aspects of the solutions of the guiding center system of equations are featured.

The classical bifurcations that occur in the SIR system were already studied in many papers. Our attention is focused on the singular bifurcations, when the system has in infinite number of periodic points at the bifurcation limit. The dynamics of the system is analyzed and the results are interpreted from a practical point of view.

Isothermal P–x vapor–liquid equilibrium and excess enthalpy (HE) data were experimentally determined for the 10 binary systems hexane, heptane, 1-octene, benzene, toluene, ethanol, methanol, ethyl acetate, dibutyl ether, and dichloromethane with N,N- dimethylacetamide using the static synthetic method and isothermal flow calorimetry, respectively. The experimental data from this work together with data taken from literature were used for the extension of the group contribution method Modified UNIFAC (Dortmund).

The aim of the paper is to study systems with one-and-a-half degrees of freedom generated by a Hamiltonian with a quartic unperturbed part and broad perturbation spectrum. To this end, an approximate interpolating Hamiltonian system is firstly studied. Behaviour of the Poincare–Birkhoff or dimerised chains in their routes to reconnection when the perturbation parameter varies is particularly presented. In the second step, a discrete system associated to the full Hamiltonian system is constructed and studied. We point out interesting properties of the dynamics of the Poincare–Birkhoff or dimerised chains, such as pairs of homoclinic orbits to the same equilibrium point (sandglass) and triple reconnection. Then we use the scenario of reconnections to explain the destruction of transport barriers in the non-autonomous system.

For process development and simulation, the group contribution concept can be successfully applied for the estimation of the missing pure component and mixture properties. This concept has the great advantage that only a limited number of group interaction parameters is required. With the support of a company consortium founded 1996 at the University of Oldenburg, the group contribution model modified UNIFAC (Dortmund) for the prediction of phase equilibria and excess properties has been continuously revised and extended. Within the consortium the number of available group interaction parameters has been doubled. At the same time, the reliability of the results was greatly improved, and the range of applicability was extended to ionic liquids, polyethers, and so forth, and systems for which no experimental data are available, e.g., reactive systems. In this paper the group interaction parameters for the sulfur groups sulfones, sulfides, and disulfides are given. Furthermore, the current status of the cons...

Limit cycle bifurcations for a class of perturbed planar piecewise smooth systems with 4 switching lines are investigated. The expressions of the first order Melnikov function are established when the unperturbed system has a compound global center, a compound homoclinic loop, a compound 2-polycycle, a compound 3-polycycle or a compound 4-polycycle, respectively. Using Melnikov’s method, we obtain lower bounds of the maximal number of limit cycles for the above five different cases. Further, we derive upper bounds of the number of limit cycles for the later four different cases. Finally, we give a numerical example to verify the theory results.

In our model the diffusion produced by a two-dimensional electrostatic stochastic field combined with a sheared magnetic field is analyzed numerically. We assumed, as in a lot of other papers, an isotropic spectrum of electrostatic fluctuations as a combination of a Gaussian one (for small wave-vectors) and a power-law k-3 (for large wave-vectors). The running and asymptotic diffusion coefficients of electrons are obtained for physically relevant parameter values.

This paper reviews some results from the theory of two-time scale dynamical systems (also called fast-slow systems) and presents the detailed analysis of some systems of interest in electrical engineering and fusion plasma physics. The aim of this work is to introduce engineers to singular perturbation methods as a tool for providing additional insights in modeling and understanding systems whose components evolve on different time scales.

The development and design of chemical processes are carried out by solving the balance equations of a mathematical model for sections of or the whole chemical plant with the help of process simulators. For process simulation, besides kinetic data for the chemical reaction, various pure component and mixture properties are required. Because of the great importance of separation processes for a chemical plant in particular, a reliable knowledge of the phase equilibrium behavior is required. The phase equilibrium behavior can be calculated with the help of modern equations of state or gE–models using only binary parameters. But unfortunately, only a very small part of the experimental data for fitting the required binary model parameters is available, so very often these models cannot be applied directly. To solve this problem, powerful predictive thermodynamic models have been developed. Group contribution methods allow the prediction of the required phase equilibrium data using only a limited number of group interaction parameters. A prerequisite for fitting the required group interaction parameters is a comprehensive database. That is why for the development of powerful group contribution methods almost all published pure component properties, phase equilibrium data, excess properties, etc., were stored in computerized form in the Dortmund Data Bank. In this review, the present status, weaknesses, advantages and disadvantages, possible applications, and typical results of the different group contribution methods for the calculation of phase equilibria are presented.

We analyze statistically the energization of particles in a large scale environment of strong turbulence that is fragmented into a large number of distributed current filaments. The turbulent environment is generated through strongly perturbed, 3D, resistive MHD simulations, and it emerges naturally from the nonlinear evolution, without a specific reconnection geometry being set up. Based on test-particle simulations, we estimate the transport coefficients in energy space for use in the classical Fokker-Planck (FP) equation, and we show that the latter fails to reproduce the simulation results. The reason is that transport in energy space is highly anomalous (strange), the particles perform Levy flights, and the energy distributions show extended power-law tails. Newly then, we motivate the use and derive the specific form of a fractional transport equation (FTE), we determine its parameters and the order of the fractional derivatives from the simulation data, and we show that the FTE is able to reproduce the high energy part of the simulation data very well. The procedure for determining the FTE parameters also makes clear that it is the analysis of the simulation data that allows to make the decision whether a classical FP or a FTE is appropriate., in press at Physical Review Letters, 2017 (6 pages, 7 figures)

Liquid–liquid equilibria (LLE) of water + acetic acid + dimethyl carbonate were experimentally specified at (298.2, 308.2, and 318.2) K. Each diagram was obtained through specifying binodal curves and tie-lines. The reliability of the experimental tie-line data was calculated by the Othmer–Tobias correlation. The nonrandom two-liquid (NRTL) and unified quasichemical activity coefficient (UNIQUAC) models were used to obtain the binary interaction parameters of the experimental tie-line data. However, universal functional (UNIFAC) and modified UNIFAC methods were used as well to predict the phase equilibrium in the system specified from experimental data using the interaction parameters between CH3, OCOO, COOH, and H2O functional groups. Distribution coefficients and separation factors were assessed for the immiscibility region.

The objective of this study is the selection of a suitable entrainer for the separation of the binary azeotropic mixture, namely methanol + dimethyl carbonate (DMC) by extractive distillation. In this study, 2-ethoxyethanol and 4-methyl-2-pentanone were considered as entrainer candidates for the separation of methanol and DMC. Isobaric vapor–liquid equilibria (VLE) were measured for the ternary mixtures methanol + DMC + 2-ethoxyethanol and methanol + DMC + 4-methyl-2-pentanone, and for their constituent binary mixtures, under reduced pressures of 66.66 kPa and 93.32 kPa. Experimental VLE data for the constituent binary mixtures were represented by the Wilson and the NRTL model. The VLE predictions for two ternary mixtures were compared with the experimental VLE data on the basis of the Wilson or NRTL parameters obtained from the constituent binary VLE data. The modified UNIFAC (Dortmund) model was also used for the prediction of the binary and ternary mixtures. The solvent effects of the two entrainer candidates investigated are discussed using the predicted results for the ternary mixtures and both 2-ethoxyethanol and 4-methyl-2-pentanone were found to be suitable entrainers for the separation of methanol and DMC. When the selectivity of 2-ethoxyethanol and 4-methyl-2-pentanone are compared, it could be concluded from the separation factors that 4-methyl-2-pentanone shows a higher selectivity.

The solubilities of NaCl, KCl, LiCl, and LiBr in pure methanol, ethanol, and acetone were measured over a temperature range from 293.15 to 333.15 K. Furthermore salt solubilities in the mixed solvents (water + methanol, water + ethanol, water + acetone, methanol + ethanol, methanol + acetone, ethanol + acetone) were determined at 313.15 K. For a few systems solubility data are reported for the first time. In a few cases a comparison with published data stored in the Dortmund Data Bank (DDB)(1) showed disagreement. The LIQUAC model was used to correlate the experimental data. The calculated salt solubilities are in good agreement with the experimental results for the systems NaCl + water + methanol and KCl + water + methanol.

The present work is devoted to investigate the existence of heteroclinic orbits in two three-dimensional autonomous systems, more exactly in the Lu and the T systems. The two systems belong to the class of Lorenz systems, having the nonlinear terms of order two. We prove that, under some constraints for the parameters, the both systems have exactly two heteroclinic orbits which are symmetrical with respect to the z -axis. We register also results on closed and homoclinic orbits for the Lu system.

This article presents a comparative study about the predictive capability of COSMO-SAC and COSMO-RS(Ol) models with respect to excess enthalpies of various binary systems. Results of the group cont...

This research has been focused on viscosities, vapor−liquid equilibria (VLE), and heat of mixing measurements for water with the following choline-based ionic liquids: choline lactate, choline glycolate, and choline methanesulfonate. Isothermal vapor−liquid equilibria were measured by means of a static VLE apparatus at (303.15, 313.15, and 323.15) K. The experimental VLE data were correlated using the NRTL and UNIQUAC models, and the root-mean-square deviations (rmsd's) are given. Furthermore, the molar excess enthalpies of water + choline glycolate and water + choline lactate ionic liquid systems have been performed at T = (303.15, 315.15, and 323.15) K using a differential scanning calorimeter. The results were fitted to a Redlich−Kister equation to determine the fitting parameters and the mean relative deviations. Viscosities of the binary aqueous systems with choline glycolate and choline lactate have been measured at 293.15 K.

The formation of internal transport barriers (ITB) in tokamaks has been experimentally associated with the region of low magnetic shear and the presence of main rational magnetic surfaces. We study the ITB from a mathematical point of view in a Hamiltonian model (the rev-tokamap model) that describes the magnetic field lines dynamics in reversed shear tokamaks. The non-twist properties of the map that generates the system are exploited in order to explain analytically the existence of ITB surrounding the shearless curve (in the low magnetic shear zone) and the robustness of invariant circles (corresponding to closed magnetic surfaces) situated in its proximity. We describe the location of the ITB for various q-profiles and perturbations of the (ideal) integrable system. We use an analytical method to estimate the maximum radius of magnetic field lines confinement, hence the position of the barrier, and we explain the destruction of invariant circles when the amplitude of the perturbation increases. The reconnection phenomena are also related with ITB and an explanation for the (experimentally observed) enlargement of ITB when the minimal value of the q-profile becomes close but less than a main rational is obtained.

Magnetic field lines behaviour in a reversed shear tokamak can be described by a one and a half degree of freedom Hamiltonian system. In order to get insights into its dynamics we study numerically a global model for a Poincare map associated to such a system. Mainly we investigate the scenario of reconnection of the invariant manifolds of two hyperbolic orbits of the same type n/m and show that it is a generic one. When the two Poincare–Birkhoff chains involved in this process are aligned in phase, i.e. they are in a nongeneric position, a sequence of two saddle–center bifurcations occur in one of the chains, interfering with the former elliptic orbit of that chain, such that at the reconnection threshold the two chains are in a generic position. Dynamics around the new created configuration at the reconnection appears to vary from a regular motion to a chaotic one. In connection with the study of this global bifurcation we give the first example of region of instability in the dynamics of a nontwist map.

Vapour–liquid equilibrium (VLE) data for the binary systems ethanol+methyl propanoate and ethanol+methyl butanoate at 326.30 and 346.30 K and vapour pressures (VPs) for both esters were measured by a circulation method. The two systems exhibit azeotropic behaviour. The VLE data were correlated using the Redlich–Kister, Wilson and NRTL equations. Molar excess volumes for the binary systems at 298.15 K were determined and correlated.

In hot laboratory plasmas, internal transport barriers (ITBs) have recently been observed, localized in the radial profile `around' rational values of the winding number ω(r) = 1/q(r). Such barriers are obviously related to the perturbed magnetic structure, described by a 1+1/2 Hamiltonian in presence of a perturbation. From the point of view of non-linear Hamiltonian dynamical systems [1], this experimental result appears highly paradoxical since rational q-values generally correspond to the less robust tori. We have studied the appearance of chaos of toroidal magnetic lines by a discrete area-preserving map named `tokamap' [2]. By increasing the perturbation, we have observed in a wide chaotic sea the destruction of the last confining Kolmogorov–Arnold–Moser surfaces, broken and transformed into permeable Cantor sets (Cantori). The flux across a Cantorus has been computed by using refined mathematical techniques due to MacKay, Mather and Aubry. We have proved that the ITB observed in the tokamap is actually composed [3] of two permeable Cantori with `noble' values of ω (in the definition of Percival), each Cantorus forming a partial (permeable) barrier inhibiting the magnetic line motion. More generally, between the dominant chains of rational islands q = m/(m−1), the most resistant barriers between q = (m+2)/(m+1) and (m+1)/m have been checked (Greene, MacKay and Stark) to be localized on the `most irrational' numbers in these Farey intervals, i.e. on the noble numbers N(1,m)≡1+[1/(m+1/G)] (where G is the Golden number), defined by their continuous fraction expansion N(i,m) = [i,m,(1)∞]. In conclusion, the study of the tokamap mapping allowed us to predict on mathematical basis that ITB can occur in tokamak plasmas not only `around' rational magnetic surfaces but more precisely on noble q−values of irrational surfaces, and to localize them by the Fibonacci series of their convergents.

Reliable azeotropic data have been measured for the binary systems ethanol+diethoxymethane, diethoxymethane+1-propanol, diethoxymethane+heptane, and cyclohexane+diethoxymethane with the help of a wire band column. Additionally molar excess enthalpies (HE) for the binary mixtures of diethoxymethane with hexane, 1-octene, methanol and ethanol at 363.15 K have been determined with an isothermal flow calorimeter. The experimental data were compared with the results using the available “ether” main group of the group contribution method Modified UNIFAC (Dortmund), which is a well-known model for the prediction of phase equilibria and excess properties. For the description of the HE data a Redlich–Kister polynomial was also used. The aim of this work is to supplement the available data base for acetal systems required for the introduction of a new “acetal” group in the Modified UNIFAC (Dortmund) model.

Solid−liquid equilibria (SLE) for the following seven systems have been measured by the visual technique: benzene, toluene, cyclohexane, 1-propanol, methanol, water, and 2-pentanone with e-caprolactone. For the description of the SLE data the NRTL model and the group contribution method Modified UNIFAC (Dortmund) were used.

International audience; The existence of transport barriers in 3/2 degrees of freedom degenerate Hamiltonian systems is studied using the associated stroboscopic maps. For small enough amplitudes of the perturbations, a transport barrier (formed by infinitely many invariant rotational circles) is proven to exist and to form in the degenerate annulus. These results are applied to Hamiltonian models which describe some magnetic configurations in tokamak plasmas. Read More: http://www.worldscientific.com/doi/abs/10.1142/S021812741350034X

Gyrotrons are microwave sources whose operation is based on the stimulated cyclotron radiation of electrons oscillating in a static magnetic field. This process is described by the system of two complex differential equations: nonlinear first order ordinary differential equation with parameter (averaged equation of electron motion) and second order partial differential equation for high frequency field (RF field) in resonator (Schrödinger type equation for the wave amplitude). The stationary problem of the single mode gyrotron equation in short time interval with real initial conditions was numerically examined in our earlier work. In this paper we consider the stationary and nonstationary problems in large time interval with complex oscillating initial conditions. We use the implicit finite difference schemes and the method of lines realized with MATLAB. Two versions of gyrotron equation are investigated. We consider different methods for modelling new and old versions of the gyrotron equations. The main physical result is the possibility to determine the maximal value of the wave amplitude and the electron efficiency coefficient.

Carotid intima-media thickness (CIMT) can be reliably determined in vivo by carotidian ultrasound and is an accessible and reliable method to assess subclinical atherosclerosis. Available epidemiological data showed that CIMT is significantly correlated with future cardiovascular events. However it has limited value to help risk stratification on top of standard risk-derived functions such as Framingham risk score. It is particularly useful in individuals classified as being at intermediate or high risk by the presence of multiple conventional risk factors.CIMT HAS A CLASS IIA (LOE: B) reccommendation for cardiovascular risk assessment according to the practice guidelines published in 2010, emphasizing the presence of high risk if the common carotid artery intima-media thickness is above the 75(th) percentile. There is no indication to measure IMT in patients with full-blown atherosclerotic carotid disease, although carotidian ultrasound still remains a very useful tool to assess the severity of disease even in these subjects.Progression of CIMT (also associated with increasing age) can be delayed by some drugs (statins, colestipol and niacin) and by risk factors modification. However, there is no consistent data demonstrating a link between progression of CIMT and coronary and cerebral events. Subsequently, studies using CIMT progression as primary outcome to indicate the influence of a certain therapy on cardiovascular risk are inherently misleading as suggested in the recently published ACC/AHA Guidelines.

Atherosclerosis is a chronic inflammatory disease started by endothelial injury and defined by arterial wall load with free and esterified cholesterol, followed by subintimal focal recruitment of circulating monocytes and T-lymphocytes that heals by fibrosis and calcification. Inflammation plays a crucial role in atherogenesis either by local cellular mechanisms or humoral consequences easily measurable in plasma. In most cases inflammation and endothelial dysfunction are triggered by cardiovascular risk factors: hypercholesterolemia, hypertension, smoking or diabetes. In other cases inflammation precedes atherosclerotic changes that occur in autoimmune diseases, as systemic lupus erythematosus and rheumatoid arthritis. In these diseases atherogenesis is mostly independent from conventional risk factors. Irrespective of its cause systemic inflammation is correlated with cardiovascular events, but currently there are controversial results regarding inflammatory markers and early atherosclerotic process. We designed a study to identify if the amplitude of inflammation expressed by multiple serum markers is correlated with the severity of the atherosclerotic process measured by coronary atheroma volume and carotid intima-media thickness. The selected inflammatory markers are associated with different pathogenic steps in atherogenesis: acute phase reactants (C-reactive protein); pro-inflammatory cytokines (TNF-alpha, interleukin-6 and -18); endothelium activation markers (soluble VCAM-1, ICAM-1); and specific factors (anticardiolipinic antibodies). We aim to enrol the two different patient subsets with early atherosclerosis: one with conventional risk factors and one with autoimmune diseases without traditional risk factors, in whom inflammation is part of the systemic disease progression.

International audience; The issue of magnetic confinement in magnetic fusion devices is addressed within a purely magnetic approach. Using some Hamiltonian models for the magnetic field lines, the dual impact of low magnetic shear is shown in a unified way. Away from resonances, it induces a drastic enhancement of magnetic confinement that favors robust internal transport barriers (ITBs) and stochastic transport reduction. When low-shear occurs for values of the winding of the magnetic field lines close to low-order rationals, the amplitude thresholds of the resonant modes that break internal transport barriers by allowing a radial stochastic transport of the magnetic field lines may be quite low. The approach can be applied to assess the robustness versus magnetic perturbations of general (almost) integrable magnetic steady states, including non-axisymmetric ones such as the important single helicity steady states. This analysis puts a constraint on the tolerable mode amplitudes compatible with ITBs and may be proposed as a possible explanation of diverse experimental and numerical signatures of their collapses.

Purpose Right ventricular (RV) apex pacing is associated with LV dyssynchrony. Alternate RV pacing sites (mid RV septum; the RV outflow tract (RVOT)) were considered, with no clear benefit. The aim of this study is to find a reliable method of septal lead placement ant to identify those pacing sites which provide a better LV electrical activation. Methods 50 consecutive patients reffered for pacemaker implants due to AV block were included. Patients with history of heart failure or LVEF Results 92%(46) of the patients had the RV lead in septal position (32 in mid RV and 14 in RVOT) while 8% (4 pts) had the RV lead on the RVOT free wall as shown by echo. An anteriorly oriented lead in the left anterior oblique fluoroscopic projection was specific for free wall position while a positive QRS in DI in RVOT position was suggestive for free wall position on the ECG. No correlation was made between paced QRS axis and LV dyssinchron. A QRS duration of>160 ms was associated with significant LV dyssinchrony (SPWMD>130 ms and septal to lateral t>70 ms). Conclusions RV lead placement on the RV septum can be reliably achieved using a specialy shaped stilet and LAO projection for confirmation. A wide paced QRS is correlated with significant intra LV dyssinchrony and therefore the pacing site with the narrowest QRS should be sought.

The dynamics of magnetic field lines and of charged particles in toroidal chambers are commonly analysed by numerically solving the dynamical equations. They may also be analysed using deterministic reduced models, i.e. low-dimensional discrete time approximations (maps) of the Hamiltonian continuous time models. We report on the accuracy of the latter method by considering the mapping technique derived from the Hamilton–Jacobi equation. The optimum time stepping in some models for the study of the magnetic field in tokamaks is determined by using local criteria. Special attention is given to the analysis of stochasticity produced by time discretization.

Background The purpose of this study was to report initial results of a phase I study using single-fraction stereotactic radiotherapy (RT) in patients with inoperable lung tumors. Methods Eligible patients included those with inoperable T1-2N0 non-small cell lung cancer (NSCLC) or solitary lung metastases. Treatments were delivered by means of the CyberKnife. All patients underwent computed tomography-guided metallic fiducial placement in the tumor for image-guided targeting. Nine to 20 patients were treated per dose cohort starting at 15 Gy/fraction followed by dose escalation of 5 to 10 Gy to a maximal dose of 30 Gy/fraction. A minimal 3-month period was required between each dose level to monitor toxicity. Results Thirty-two patients (21 NSCLC and 11 metastatic tumors) were enrolled. At 25 Gy, pulmonary toxicity was noted in patients with prior pulmonary RT and treatment volumes greater than 50 cc; therefore, dose escalation to 30 Gy was applied only to unirradiated patients and treatment volume less than 50 cc. Ten patients received doses less than 20 Gy, 20 received 25 Gy, and two received 30 Gy. RT-related complications were noted for doses greater than 25 Gy and included four cases of grade 2 to 3 pneumonitis, one pleural effusion, and three possible treatment-related deaths. The 1-year freedom from local progression was 91% for dose greater than 20 Gy and 54% for dose less than 20 Gy in NSCLC (p = 0.03). NSCLC patients had significantly better freedom from relapse (p = 0.003) and borderline higher survival than those with metastatic tumors (p = 0.07). Conclusions Single-fraction stereotactic RT is feasible for selected patients with lung tumors. For those with prior thoracic RT, 25 Gy may be too toxic. Higher dose was associated with improved local control. Longer follow-up is necessary to determine the treatment efficacy and toxicity.

Predictions of vapor–liquid equilibria at high temperatures and pressures were obtained by applying a modified procedure using the Huron–Vidal mixing rule based on available activity coefficients at infinite dilution and low pressures. These activity coefficients were calculated with so-called conductor-like screening model for real solvents (COSMO-RS) and with a variation of this model, known as segment activity coefficient (COSMO-SAC) model. In this work, the performances of the mixing rule (HVID model) coupled with the SRK equation of state and a reduced UNIQUAC model are presented for six binary systems and a ternary system, whose VLE data are available over a large temperature and pressure range.

We present the case of a 53 years-old woman presenting with congestive heart failure and pleural and pericardial effusions, in whom transthoracic and transesophageal echocardiography revealed multilocular cardiac tumor involving the left atrium wall, extending into the pericardium. Tumor was excised surgically and proved to be a malignant fibrous histiocytoma, primarily confined to the heart. Despite surgery followed by chemotherapy, the patient died a few months later. This is the 47th case of primary cardiac fibrous malignant histiocytoma reported in the literature. The pericardial involvement has been only rarely reported. Echocardiography was the method of diagnosis before rapid referral to surgery.

Despite the abundance of reports concerning the increased frequency of diabetes and impaired glucose tolerance in chronic liver diseases, the mechanisms underlying this phenomenon have not been resolved. 30 patients with hepatitis C virus (HCV) infection and 17 with hepatitis B virus (HBV) infection who showed an altered responds to a standard oral glucose tolerance test were investigated in order to evaluate their pancreatic-endocrine features. We have also evaluated 40 patients (20 with HCV infection and 20 with HCB infection) who developed diabetes after diagnosis of liver disease. Patients with HBV infection showed signs of enhanced insulin resistance but overt diabetes develops in those who, in addition to insulin insensitivity, have a relative defect of insulin secretion. In patients with HCV infection the significantly lower plasma insulin and C-peptide levels suggest that impairment of insulin secretion is the main mechanism leading to both glucose intolerance and overt diabetes.

Single trajectories of magnetic line motion indicate the persistence of a central protected plasma core, surrounded by a chaotic shell enclosed in a double-sided transport barrier : the latter is identified as being composed of two Cantori located on two successive "most-noble" numbers values of the perturbed safety factor, and forming an internal transport barrier (ITB). Magnetic lines which succeed to escape across this barrier begin to wander in a wide chaotic sea extending up to a very robust barrier (as long as L, TEX file, 84 pages including 32 color figures. Higher quality figures can be seen on the PDF file at http://membres.lycos.fr/fusionbfr/JHM/Tokamap/JSP.pdf

The main goal of this work is the implementation of some mathematical notions like attractors, orbits, sensitivedependence and chaos in the study of the multiple reflection of a light beam. We shall analyse some concrete situations ofreflection on a circle, on a rectangle and the general case of a conic, all this cases with direct application to the optical resonant cavities oflasers. Using some general results concerning the dynamical systems, we shall point out the conditionsthat the multiple reflection must satisfy in order to obtain a periodic reflection or chaotic behaviour. 1. INTRODUCTION Despite the fact that only the wave theory offers a good explanation of the nature of the light and can be applied without any limitations, the geometrical approximation of the light rays travelling in straight lines turns out to be equally useful inthe study of optical instruments. This is the case for example with the resonant cavities of the lasers, where a whole set of theoretical problems can be successfully studied in the context of the geometrical optics.One of this problems concerns the stability and the periodicity of a light ray during the multiple reflection in a resonator.The apparent simple problem of the multiple reflection of a light beam could appear like an interesting example of a discrete

Using Hamiltonian models for the magnetic field lines, we propose a methodology to improve their confinement through the creation of transport barriers. A local modification of the safety profile creating a low-shear zone is shown to be sufficient to locally enhance drastically the regularity of the magnetic field lines without requesting a reversed shear. The optimal benefits of low-shear are obtained when the value q 0 of the safety profile in the low-shear zone is sufficiently far from the main resonance values m/n with low m and n, in the case of large enough values of those (m, n) mode amplitudes. A practical implementation in tokamak plasmas should involve electron cyclotron current drive to locally modify the magnetic shear.

Larger scale plasma instabilities not leading to an immediate termination of a discharge often result in periodic nonlinear perturbations of the plasma. A minimal possible model is formulated for description of the system with drive and relaxation processes which have different time scales. The model is based on two equations: the first being responsible for the relaxation dynamics and the second for the drive. The model can be generalized to describe the pellet injection.

The construction of explicit near-symplectic mappings for generic Hamiltonian systems with the utilization of Lie transforms is presented. The method is mathematically rigorous and systematically extended to high order with respect to a perturbation parameter. The explicit mappings are compared to their implicit counterparts, which use mixed-variable generating functions, in terms of conservation of invariant quantities, calculation speed and accurate construction of Poincare surfaces of sections. The comparative study considers a wide range of parameters and initial conditions for which different time scales are involved due to large differences between internal and external frequencies of the system.