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SUMMARY Despite their popularity, the use of bulk-fill composites remains controversial, both in terms of their properties and their in-depth development. The objectives of the present work were (1) to provide a more comprehensive evaluation of the quality of cure in depth of commercially available bulk-fill composites by combining various key mechanical and biological characterization methods, (2) to evaluate the inter-material differences when optimally cured, and (3) to evaluate the efficiency of an antioxidant—N-acetyl-cysteine (NAC)—to restrain the adverse effects of the leached components on cell viability. Nine bulk-fill composites (including flowable and high-viscosity materials) were investigated and compared to two conventional resin-based composites, one flowable and one high-viscosity restorative material. The materials were injected or packed into Teflon molds of various configurations, up to 6 mm material thickness. They were then light-cured from the top for 20 seconds with Bluephase G2 (Ivoclar Vivadent, irradiance = 1050 mW/cm2). The following physico-mechanical properties were measured for the upper (0–2 mm), intermediate (2–4 mm), and lower (4–6 mm) layers: degree of conversion using Raman Spectrometry (DC, in %), microhardness using a Vickers micro-indenter before (VHN dry) and after 24 hours of storage in ethanol (VHN EtOH), and flexural strength (in MPa) and flexural modulus (in GPa) using a three-point bend test. Each composite layer and an uncured layer were also stored for one week in a standard cell growth medium to generate conditioned media. Human dental pulp cells were then cultured for 24 hours with the latter and cell viability was measured using an MTS assay. A similar experiment was repeated with conditioned media produced in contact with uncured composites, with and without the addition of 4 mM NAC. The data were subjected to a Shapiro-Wilk test, then one-way ANOVA or Kruskal-Wallis test, followed either by Tukey’s test (inter-material comparison) or by Dunnett’s or Dunn’s test (comparison between layers relative to the upper one). The level of statistical significance was set at 0.05. Some materials (EverX, X-traF, VenusBF, X-traB) did not show any significant differences (p>0.05) for any of the properties considered between the intermediate layers compared to the upper one (considered as reference). Others displayed significant differences, at least for some properties, highlighting the value of combining various key mechanical and biological characterization methods when investigating the quality of cure in depth. Significant inter-material differences (p

Background Immune checkpoint inhibitors (ICIs) are a novel class of antineoplastic drugs which have dramatically changed the management of non-small cell lung cancer. ICI-associated cardiotoxicity is rare, but potentially fatal, presenting in most of cases as autoimmune acute myocarditis during the first phase of treatment. However, since an extensive cardiac monitoring is not routinely performed in most immunotherapy trials, the true incidence of ICIs related cardiac effects is largely unknown. Aim Aim of our study is to ascertain a possible subclinical cardiac involvement in patients with non-small cell lung cancer treated with ICIs. Methods We prospectively recruited 40 patients (13 males; mean age 64.3 ± 8.3 years) starting immunotherapy with PD-1/PDL-1 inhibitors for non-small lung cancer between January and August 2018. Demographic and clinical data were recorded and all patients underwent a standard 12-lead ECG and a transthoracic echocardiogram with assessment of left ventricular global longitudinal strain (LV GLS). Furthermore, blood samples for pro BNP-nt and high sensitivity Troponin T (hsTnT) measurements were collected. Serial assessments were performed before and 1 and 3 months after initiation of immunotherapy. Results A history of previous coronary artery disease was documented in eight cases (20%). At follow-up no cardiovascular events were recorded. Compared with baseline, echocardiographic parameters of ventricular function did not significantly changed at 1 and 3 months (LVEF 61 ± 6% at baseline, 61 ± 5% at 1 month, 60,2 ± 5% at 3 months, p =0.1; E/E’at baseline 9.2 ± 3, 9.2 ± 2.8 at 1 month, 9.1 ±3,5 at 3 months, p = 0.2;TAPSE 20 ± 3.4 mm at baseline, 21.3 ± 2.8 mm at 1 month, 20 ± 3.8 mm at 3 months, p =0.1; LV GLS -20.3 ± 3.6% at baseline, -20.8 ± 2.3% at 1 month, -20.6 ± 3% at 3 months; p = 0.4). Analogously, no significant increase in circulating levels of cardiac biomarkers was found with hsTnT Conclusions In our study no significant clinical or subclinical evidence of myocardial involvement was detected during treatment with ICIs in patients with non-small cell lung cancer, thus suggesting the potential cardiovascular safety of this promising class of antineoplastic drugs.

Polymer-Dispersed Cholesteric Liquid Crystals(PDCLC)have been obtained using different cholesteric liquid crystals mixtures by the Photopolymerization-Induced Phase Separation method. PDCLC samples of different thickness and different LC concentrations have been studied. The selective reflection spectra for different voltages have shown maximum reflectivity in the infrared region.

The coarsening dynamics of kinks in a one-dimensional conserved order parameter system is investigated experimentally in a nematic liquid crystal of negative dielectric anisotropy under a magnetic field. Without an external electric field, a straight splay-bend wall is formed in the cell perpendicular to the magnetic field. When an electric voltage, higher than a critical value, is applied to the liquid crystal cell, the straight wall spontaneously tilts locally toward the magnetic field direction and forms a zigzag line. Then the zigzag pattern starts to coarse. Considering the vertexes of the zigzag as kinks in a one-dimensional conserved Ising system, the coarsening dynamics is discussed. It is found that, as expected by the theories for one-dimensional kink dynamics, the characteristic length increases logarithmically in time and the dynamical scaling law holds in the coarsening process.

We have investigated the behavior of a cholesteric mixture, consisting of the negative dielectric anisotropy liquid crystal MBBA and a chiral dopant S811(1%b.w.). In the phase diagram a.c. applied voltage versus confinement ratio, in addition to the transition previously observed, before reaching the domain of the transition TIC(Translationnary Invariant Cholesteric)–modulated TIC, we have observed a new stability domain for the topological bubble. These bubbles are now surrounded by the TIC domains and necessarily associated to an hyperbolic − 1 defect of the in plane director component.We have also obtained experimentally topological defect chains, formed by topological dipoles similar to the ones formed in 2 compound materials: liquid crystal/solid spheres or liquid crystal/liquid droplets.

A new instability for a splay-bend Ising wall was found in a 5CB nematic liquid crystal layer. This instability, which occurs in the presence of an external horizontal magnetic field, is driven by the elastic anisotropy of the liquid crystal material. Depending on the homogeneity of the magnetic field, the unstable straight interface evolves towards a new steady state or undergoes a spinodal decomposition into facets. Energy arguments are given in order to explain these physical phenomena.

We study here the behaviour of S=+1 and S=-1 disclinations in SmC films submitted to a rotating electric field. In agreement with Cladis et al. experiments we observe that a S=+1 disclination submitted to large enough torque leaves the centre of the film and is orbiting around a target-like pattern. A single S=-1 disclination submitted to a torque behaves differently: independently of the applied torque, it stays in the centre of the film. We explain this difference as due to the presence (S=+1) and the absence (S=-1) of energy barriers with respect to the phase winding.

We will show here that, in a two-dimensional liquid crystal system where disclinations are present, the elastic torque cannot balance alone an external torque; a hydrodynamic flow must indeed occur so that the system can reach a stationary state. We suggest calling such flows topological flows. We will indicate how they are produced by the Ericksen forces.

We describe the experimental properties of metastable domains associated with the presence of an Inversion Wall (IW) and observed with homeotropically anchored nematic and cholesteric liquid crystals sandwiched between parallel glass plates. Such a distorted situation, stabilized by the application of an electric field parallel to the plates as described in reference [1], can also be obtained transiently either when filling a sample cell by capillarity or in some studies of directional solidification at the N-I interface [2]. The application of an electric field perpendicular to the plates with Delta epsilon 0 materials allows control of the reversal region thickness in the bulk of the sample and its associated birefringence. This IW can be stabilized in the particular case of low lateral extension globules in which the line tension of the looped disclination separating the pi wall regions from the homeotropic regions counterbalances the unfavourable bulk free energy. Particular attention is devoted to th...

A side chain mesomorphic cooligomer presents a large blue phase temperature domain. The cooling down of the sample from BPI allows to quench coloured crystallites below the glass transition of this material. Observations by transmission electron microscopy on microtome cuts of these crystallites reveal the presence of mono- and bi-periodic domains corresponding to the respective quench of cholesteric and BPI phases at room temperature. The use of an atomic force microscopy technique directly on the cuts observed by electron microscopy, and the detection of the same textures by both methods reveal unambiguously that the TEM contrast originates from strong, “cut-induced”, surface relief. The nature of this corrugation is discussed using numerical simulations derived from a Ginzburg-Landau approach.

In recent work, Oswald and collaborators describe the thermodynamical phase diagrams of a large pitch cholesteric, confined between glass plates with homeotropic alignment conditions, in the neighbourhood of the critical confinement and in the presence of an AC electric field. In the case of a negative dielectric anisotropy, and with a low confinement ratio C, they have shown both experimentally and theoretically that the electrical destabilization possesses a second order character, as in the case of the nematic Freedericksz transition. It is consequently possible to describe and to simulate numerically the equilibrium (under an AC field) and dissipative, out of equilibrium (under a DC field) patterns obtained experimentally, by the use of a Ginzburg–Landau model, deduced from symmetry arguments. The order parameter used here is the projection of the director in the mid-plane of the sample. The spiral shaped textures obtained in the out of equilibrium case are probably among the first simple phy...

We report experimental investigation and theoretical interpretation of the formation of sprial waves in a nematic liquid crystal subjected to a rotating magnetic field and a high frequency electrical field.

A side chain mesomorphic co-oligomer possesses a large blue-phase temperature domain. Upon cooling down from blue phase I colored crystallites are quenched below the glass transition of this material. The microtome cut of these crystallities and their observation by transmission electron microsocopy reveal the presence of biperiodic textures different from the cholesteric ones. Image analysis of these textures, associated with an original model of diffraction confirms the presence of the ${\mathit{O}}^{8\mathrm{\ensuremath{-}}}$ symmetry and suggests that the transmission electron microscopy contrast obtained here has to be associated with changes of the molecular orientations in the bulk of the sample.

The blend of an industrial cooligomer side chain cholesteric material with a polar small molecule liquid crystal of reversed chirality induces a low temperature smectic A phase [1]. We present here the change in the textural characteristics at the SA-Ch transition observed by optical microscopy between untreated glass slides: particular fingers, different from those recently described [2], are obtained for a slow increase of temperature, starting from an unperturbed spontaneous homeotropic SA domain. These fingers, coexisting with large SA domains, are understandable as 180° Bloch walls introducing progressively the helicity in the medium. Over a large temperature domain, these chiral fingers coexist in an apparent thermodynamic equilibrium with the normal SA phase, suggesting the occurrence of an analogue [3,4] of the Shubnikov superconducting phase: probably due to the presence of the glass slides, the geometry of the screw dislocations, comparable to the vortex of type 2 superconductors, is di...

Archimedian spiral wave instabilities have been discovered in chemical [1] and biological systems [2]. We present here the first example of such an instability pattern, encountered in a physical medium [3]. This instability is directly observed by polarized optical microscopy, on a positive dielectric anisotropy smectic A sample with homeotropic organization between parallel glass slides. The arm of the spiral is probably constituted of a 180° Bloch wall, separating indistinguishable smectic domains, and incorporating progressively the helicity of the cholesteric phase, excluded from the smectic.

We have shown recently that a side chain chiral industrial co-oligosiloxane exhibits an original blue phase behaviour at the cholesteric-isotropic transition [1–3]. This same material has been studied dissolved in various polar small molecule nematic or cholesteric liquid crystals and it was shown that these associations are responsible for a large induced smectic domain. These systems allow the adjustment of the smectic A-cholesteric transition temperature from 180°C to room temperature, depending on the nature and concentration of the associated small molecule liquid crystal. Moreover the kinetics of this transition is strongly slowed down at high co-oligomer concentrations, suggesting, as confirmed by a preliminary X-ray study on the pure material, that the presumed glass transition allowing for the quenching of the Bragg optical properties at room temperature is in fact strongly associated with strong smectic correlations between the mesogenic parts.

We recently showed that a side-chain industrial co-oligosiloxane presents a quenchable enlarged blue phase behaviour at the cholesteric-isotropic phase transition. In this paper, we present the results of a structural study based on X-ray diffraction, differential scanning calorimetry and optical measurements. In particular, the smectic A organisation is demonstrated in the lower temperature domain, which was hitherto understood as a cholesteric phase. A structural model for this phase is proposed on the basis of the analysis of the anisotropic scattering of stretched fibers. Our results also suggest that the observed glass transition is indeed a rather complex phenomenon, which seems to involve not only the freezing of the main chains, but also smectic correlations at the side-chain level. Moreover, the calorimetric study indicates that, notwithstanding the conservation of the processed film's optical properties, low kinetic reorganisations occur at room temperature.

In the past few years, there have been important developments concerning the role and the use of chirality in liquid crystals. An example which is now relatively well known is the chiral smectic C* low molecular weight liquid crystal (LMWLC) which lowers the response time of displays by a factor between one hundred and one thousand [1-3]. In chiral liquid crystal polymers (cholesteric or twisted nematic and smectic C*), it is necessary to understand the relation between the chemical structure and the properties of mesophases in liquid and solid polymer. Furthermore, chirality is also found in abundance in biopolymers and may be important for life processes. Applications in industry (high modulus fibers, sensors, non linear optics...) have already been realised or are being pursued. The aim of this paper is to emphasize the polymer character of these liquid crystals. What is the influence of the molecular weight, the degree of substitution, the viscoelasticity and the existence of a glass transition? How to use the polymer character to obtain new informations on the liquid crystal state or to make new devices? This rapid overview roughly covers the following parts: (1) Formation and general properties of cholesteric mesophases: we give a rapid discussion of thermotropics and lyotropics, of the influence of degree of polymerisation, degree of substitution, concentration, temperature..., on the cholesteric-isotropic transition and on the order observed by textures or as described more quantitatively by the order parameter. (2) Optical properties: we give a brief presentation of a theoretical work concerning the pitch prediction taking into account the asymmetric term in the interaction potential and the comparison with experimental results. (3) Textures and defects which are mainly observed in these mesophases. (4) Flow properties and rheological behaviour which are fundamental for processing. (5) Blue phases near the isotropic-cholesteric transition which are discussed with emphasis on the specificity of the polymer state. It is usual to distinguish main chain and side chain liquid crystal polymers [4, 5], which may be modelled as indicated in Fig. 1. Cellulosic derivatives are good examples of main chain cholesteric polymers [6]. Cellulose is a very abundant polymer: each year, biosynthesis produces about 1011 tons of cellulose. It readily accepts grafting of substituents, thus producing derivatives like cellulose acetate of hydroxypropylcellulose. Examples of side chain liquid crystal polymers are those obtained with homo- or copolymers of polyacrilate, polymethacrylate or polysiloxane.

A thermally stimulated current investigation has been carried out on a polybutadiene liquid crystal side chain polymer, in order to study the dielectric relaxation of both main and side chains. Two TSC peaks have been found showing the existence of motions of the backbone and reorientations of the mesogenic units.

Although platinum-based two-drug combinations represent the elective therapeutic approach for advanced/metastatic NSCLC, there is still interest in exploring the efficacy and tolerability of platinum-free combinations including third generation agents in selected NSCLC population. Based on the satisfying activity of gemcitabine (G), ifosfamide (I) and paclitaxel (T) as single agents in NSCLC, we have designed a phase II study to explore an alternative approach to platinum-containing regimens using a combination of these three drugs. To investigate the activity/toxicity of T 175 mg/m2 on day 1, I 3 g/m2 on day 1 (with Mesna uroprotection) and G 1,000 mg/m2 on day 1–8, every 3 weeks in the treatment of advanced/metastatic NSCLC, 46 patients (38 male, 8 female) with NSCLC were enrolled: mean age 58 (range 33–70); Stage IIIB/IV = 15/31; ECOG PS 0-1/2 = 31/15; Histology: adenocarcinoma = 20, squamous = 14, large cell = 3, NSCLC = 8, adenosquamous = 1. A total of 221 cycles have been administered (median number 4.8 for patients). In intent-to-treat analysis, partial response was achieved in 17 patients (36.95%), stable disease and progressive disease was detected in 16 (34.78%) and 10 (21.73%) patients, respectively. Time to progression was 30.9 weeks; median survival time was 42.7 weeks; the survival rates at 12 and 18 months were 34.79 and 15.21%, respectively. No toxic deaths occurred. No patients experienced grade 4 neutropenia and thrombocytopenia. Neutropenia grade 3 occurred in 10 patients (21.7%); Anemia grade 3 in 1 (2.1%); Thrombocytopenia grade 2 in two patients (4.3%) and grade 3 in one (2.1%). Peripheral neuropathy grade 1 occurred in ten (21.7%) and grade 2 in two patients (4.3%). Additional non-haematological toxicities were mild nausea, emesis and fatigue. GIT is well tolerated and active regimen in both advanced and metastatic NSCLC. These data suggest future investigations for GIT schedule as a possible alternative to platinum-based regimens in selected advanced/metastatic NSCLC patients where survival, tolerability and quality of life are the primary goals.

The coarsening dynamics of a zigzag wall formed in nematic liquid crystals under external fields is investigated experimentally. The vertexes of zigzag can be considered as kinks in a one‐dimensional order parameter system and the geometrical constrain associated to the necessary equal length sum of zig and zag segments impose a conserved quantity in this Cahn‐Hilliard type problem. We consequently use this experiment to investigate the spinodal decomposition in a one dimentional conserved order parameter system. It is found that, as expected by the theories for one‐dimensional kink dynamics, the characteristic length of the system L(t) increases logarithmically in time and the dynamical scaling law holds in the coarsening process.

We study the zigzag instability coarsening of splay-bend walls formed in a nematic liquid crystal under external fields. The vertexes of zigzag can be considered as kinks in a one-dimensional order parameter system and the geometrical constraints associated with the necessary equal length sum of zig and zag segments impose a conserved quantity in this Cahn-Hilliard-type problem. In the late stage of coarsening, the characteristic length of the system L(t) shows a logarithmic increase in time and the dynamical scaling law holds. We then try to extract the nontrivial asymptotic scaling exponent lambda of the two-time correlation function, defined by lim(phi(0,t)phi(0,t('))approximately [L(t)/L(t('))](-lambda). The scaling exponents with respective time references, t(')=32 and 64 s, after quench are found to be lambda approximately 2 which is larger than the value with respective time reference t(')=0, predicted by numerical simulation.

It was recently shown that weakly connected cellular neural/nonlinear networks (consisting of locally coupled oscillators) represent a suitable architecture for modelling biological neuro-computers. Such networks are described by large systems of nonlinear differential equations and may exhibit a rich dynamics, including chaos and complex bifurcation phenomena. We focus on space invariant cellular nonlinear networks and show that their dynamic behavior can be investigated through a spectral method, based on the application of the describing function technique. For a generic coupling, the spectral approach yields some approximate analytical conditions, that are useful for estimating some important network features and in particular for distinguishing between stationary (stable) and nonstationary behavior. In case of weak coupling the spectral method allows one to estimate the whole set of stable and unstable periodic limit cycles.

The steady-state behavior of distributed networks containing a single switch is studied by means of a spectral technique. As a fundamental result a compact representation of the Fourier transform (FT) of the current flowing through the switch is obtained. Such an FT involves a infinite number of unknowns, that are determined by solving a suitable set of equations, through a regularization procedure.

We have experimentally observed the pattern instabilities of an Ising wall formed in a nematic or cholesteric liquid crystal layer. We have deduced an envelope equation, relevant close to the Freedericksz transition, from which we derived an equation for the dynamics of the interface in the vicinity of its bifurcation. In the case of the zig-zag instability, this model is characterized by a conservative and variational order parameter whose gradient satisfies a Cahn-Hilliard equation. We have also investigated the influence of slightly broken symmetries on the dynamical behaviour of the system. The disappearance of the interface translational invariance or of the reflection symmetry along the wall axis may induce new interfacial patterns which have been both experimentally and theoretically pointed out.

When a homeotropically aligned nematic liquid crystal cell is placed above two permanent magnets forming a magnetic quadrupole, a straight splay-bend wall, or a so-called Ising wall, is formed. With a material of positive dielectric anisotropy, it has been shown that the application of an electric field perpendicular to the plates leads to a zigzag instability of the wall, exclusively related to the elastic anisotropy of the liquid crystal. In this case, the coarsening process of the zigzag is very slow, which in turn leads to experimental difficulties concerning its quantitative investigation. If a material of negative dielectric anisotropy is used under an electric field with low voltage and low frequency, two convective rolls appear along the Ising wall due to the charge focusing effect, which is also responsible, at a higher voltage in the homogenous tilted regions, for the appearance of Williams domains electrohydrodynamic instability. If the voltage is higher than a threshold value, the straight Ising wall spontaneously breaks into a zigzag shape and a fast coarsening of the zigzag proceeds, associated with the annihilation of two neighboring vertices. In the present paper, the coarsening dynamics of this system, which can be considered as a one-dimensional Ising situation, are investigated experimentally. At late times, the average width of the zigzag increases logarithmically with time. This finding is consistent with the theory and also with the numerical simulation of a one-dimensional Cahn-Hilliard situation having a conserved order parameter. The scaling analysis of size distribution of the Ising domain, the shape of the power spectrum, and of the correlation function of the Ising order parameter, as well as the number density correlation functions of kinks also confirms that the dynamical scaling law predicted for one-dimensional conservative systems holds for the coarsening process. As supposed from symmetry arguments, it is confirmed that this experiment constitutes a one-dimensional analog of spinodal decomposition.

Many techniques have been proposed for studying wedge shaped regions: among them it is important to mention the Malyuzhinets (1958) approach, which is based on the Sommerfeld representation. This technique yields an elegant formal procedure for solving difficult problems, like the diffraction by wedges with given surface impedances. However, even if the Sommerfeld integral is a valid ansatz for representing the solutions of the wave equation in angular regions, the Laplace transform appears to be a more valid representation, because of its solid mathematical foundation. Other authors have shown that the Laplace transform technique may be an alternative with respect to the Malyuzhinets approach, even if in some cases it is not so simple and elegant. In this paper we propose a new technique, based on the Laplace representations of the electromagnetic field, for solving isorefractive angular regions excited by an incident E-polarized plane wave in the z-direction.

This work provides an application of the harmonic balance (HE) technique to the stability and bifurcation analysis of limit cycles of dynamical systems amenable to be expressed in Lur'e system form. A numerically efficient spectral approach is exploited to evaluate the system limit cycle with an arbitrary number of harmonic components, which are then explouted to perform a linearized, small-change stability analysis of the limit cycle itself. On the basis of a Mittag-Leffer expansion of the determinant of the infinite matrix representing the linearized system, the limit cycle Floquet multipliers (FM) are evaluated and exploited to perform the bifurcation analysis. As an example of application, parameter space bifurcation conditions for classical Chua's circuit are thoroughly examined.

In this paper we present a new method for approximating the period-doubling locus of a piecewise-linear model of the Colpitts oscillator. This method exploits harmonic balance techniques for solving the variational equation associated with a generic limit cycle. In this way conditions for a period-doubling bifurcation are derived.

The spiral waves observed in a liquid crystal submitted to a vertical electric field and a horizontal rotating magnetic field are explained in the framework of a purely mechanical description of the liquid crystal. The originality of the experiment described in this paper is the presence of the vertical electric field which allows us to analyze the spiral waves in the framework of a weakly nonlinear theory.

A type of excitable medium---an elastic excitable medium---has been created by incorporating the Belousov-Zhabotinsky reaction into a polyacrylamide-silica gel. It permits one to address the problem of how the cardiac muscle contractions affect the dynamics of rotating spiral waves. Investigations of the effects of mechanical deformations on the excitation wave propagation exhibit a resonance dynamics of vortices. For equal frequencies of deformation and of vortex rotation, vortices drift. The drift velocity is about 3% of the excitation wave velocity, for a 50% elongation. The direction of the drift does not coincide with the stretching direction and can be varied by changing the phase shift between deformations and vortex rotation. Numerical calculations suggest that the effects of mechanical deformations on excitation wave propagation are independent of the exact nature of the excitable medium.

In this Rapid Communication we derive a simple dynamical model for the unwinding transition of a cholesteric liquid crystal. Our model describes not only the equilibrium but also the nonequilibrium features of the transition. In particular, our model is in qualitative agreement with the experimental observations of systems containing rotating spiral waves, all of the same handedness.

The functional study of visual pathways by means of pattern reversals VEPs (visual evoked potentials) was used as a noninvasive method in the study of diabetic patients, but the correlations between alterations in VEPs and the involvement of peripheral nervous system were not explored. Among 35 diabetic patients not suffering from retinopathy, we tested early deteriorations in visual pathways by means of pattern reversals VEPs and we considered similarities between these alterations, clinical metabolic parameters of the disease and clinical and paraclinical aspects of polyneuropathy (PNP). Four of these patients were insulin-dependent and 31 non-insulin-dependent, all with normal electroretinography and fluorangiography. Monitoring control of diabetes was performed by measuring hemoglobin HbA1. The control group was composed of 35 healthy subjects with normal neurologic and ophthalmologic examinations and normal visual acuity. In all subjects we tested four peripheral nerve conduction velocities (PNCV) (sensory and motor conduction of median nerve, motor conduction of peroneal nerve, anthidromic sensory conduction of sural nerve) diabetic patients were distributed in two groups according to the presence (group A, 15 patients) or absence (group B, 20 patients) of polyneuropathy. Pattern reversals PEVs were recorded after mono and binocular stimulation; screen was 25 x 18 cm with black and white check board pattern, check size 1.1 cm. Subject-to-stimulus distance was 1 m, corresponded to a visual angle of 38 degrees. Active electrode were located in Oz, O1 and O2, reference electrode in Fz.(ABSTRACT TRUNCATED AT 250 WORDS)

Steady state solutions, suitable for field-reversed configurations (FRCs) sustained by rotating magnetic fields (RMFs) are obtained by properly including three-dimensional effects, in the limit of large FRC elongation, and the radial component of Ohm’s law. The steady electrostatic potential, necessary to satisfy Ohm’s law, is considered to be a surface function. The problem is analyzed at the midplane of the configuration and it is reduced to the solution of two coupled nonlinear differential equations for the real and imaginary parts of the phasor associated to the longitudinal component of the vector potential. Additional constraints are obtained by requesting that the steady radial current density and poloidal magnetic flux vanish at the plasma boundary which is set at the time-averaged separatrix. The results are presented in terms of the degree of synchronism of the electrons with the RMF and compared with those obtained when radial current effects are neglected. Three important differences are observed when compared with the case without radial current density. First, at low penetration of the RMF into the plasma there is a significant increase in the driven azimuthal current. Second, the RMF amplitude necessary to access the high synchronism regime, starting from low synchronism, is larger and the difference appears to increase as the separatrix to classical skin depth ratio increases. Third, the minimum RMF amplitude necessary to sustain almost full synchronism is reduced.