External and intrinsic anchoring in nematic liquid crystals: A Monte Carlo study

We present a Monte Carlo study of external surface anchoring in nematic cells with partially disordered solid substrates, as well as of intrinsic anchoring at free nematic interfaces. The simulations are based on the simple hexagonal lattice model with a spatially anisotropic intermolecular potential. We estimate the corresponding extrapolation length $b$ by imposing an elastic deformation in a hybrid cell-like nematic sample. Our estimates for $b$ increase with increasing surface disorder and are essentially temperature--independent. Experimental values of $b$ are approached only when both the coupling of nematic molecules with the substrate and the anisotropy of nematic--nematic interactions are weak.Comment: Revisions primarily in section I

A Note on Non-equilibrium Work Fluctuations and Equilibrium Free Energies

We consider in this paper, a few important issues in non-equilibrium work fluctuations and their relations to equilibrium free energies. First we show that Jarzynski identity can be viewed as a cumulant expansion of work. For a switching process which is nearly quasistatic the work distribution is sharply peaked and Gaussian. We show analytically that dissipation given by average work minus reversible work $W_R$, decreases when the process becomes more and more quasistatic. Eventually, in the quasistatic reversible limit, the dissipation vanishes. However estimate of $p$ - the probability of violation of the second law given by the integral of the tail of the work distribution from $-\infty$ to $W_R$, increases and takes a value of $0.5$ in the quasistatic limit. We show this analytically employing Gaussian integrals given by error functions and Callen-Welton theorem that relates fluctuations to dissipation in process that is nearly quasistatic. Then we carry out Monte Carlo simulation of non-equilibrium processes in a liquid crystal system in the presence of an electric field and present results on reversible work, dissipation, probability of violation of the second law and distribution of workComment: 15 pages, 4 figure

High-Temperature series for the RPn−1RP^{n-1} lattice spin model (generalized Maier-Saupe model of nematic liquid crystals) in two space dimensions and with general spin dimensionality n

High temperature series expansions of the spin-spin correlation functions of the RP^{n-1} spin model on the square lattice are computed through order beta^{8} for general spin dimensionality n. Tables are reported for the expansion coefficients of the energy per site, the susceptibility and the second correlation moment.Comment: 6 pages, revtex, IFUM 419/FT, 2 figures not include

Viscosities of the Gay-Berne nematic liquid crystal

We present molecular dynamics simulation measurements of the viscosities of the Gay-Berne phenomenological model of liquid crystals in the nematic and isotropic phases. The temperature dependence of the rotational and shear viscosities, including the nonmonotonic behavior of one shear viscosity are in good agreement with experimental data. The bulk viscosities are significantly larger than the shear viscosities, again in agreement with experiment.Comment: 11 pages, 4 Postscript figures, Revte

Cancer risk in hospitalised psoriasis patients: a follow-up study in Sweden

We examined overall and specific cancer risks among Swedish subjects who had been hospitalised one or more times for psoriasis. A database was created by identifying such patients from the Swedish Hospital Discharge Register and linking them with the Cancer Registry. Follow-up of patients was carried out from the last hospitalisation through 2004. A total of 15 858 patients were hospitalised for psoriasis during 1965–2004, of whom 1408 developed cancer, giving an overall standardised incidence ratios (SIRs) of 1.33. A significant excess was noted for squamous cell skin cancer, and for cancers of the upper aerodigestive tract, oesophagus, stomach, liver, pancreas, lung, kidney and bladder as well as non-Hodgkin lymphoma. Many of these may reflect the effects of alcohol drinking and tobacco smoking. Patients with multiple hospitalisations showed high risk, particularly for oesophageal (SIR 6.97) and skin (SIR 4.76) cancers

28043 Roflumilast cream significantly improves chronic plaque psoriasis in patients with steroid-sensitive area involvement

Roflumilast cream is a nonsteroidal, selective phosphodiesterase-4 inhibitor in development for plaque psoriasis (PsO). A double-blind, phase 2b trial randomized adults with PsO to once daily roflumilast 0.3%, 0.15%, or vehicle for 12 weeks (NCT03638258).(1) Efficacy was assessed using Investigator Global Assessment (IGA), Worst Itch Numeric Rating Scale (WI–NRS), and Psoriasis Symptom Diary (PSD). This posthoc analysis reports efficacy and safety in patients with steroid-sensitive area involvement (plaques on the face, neck, or in intertriginous areas). Of 331 patients, 160 had steroid-sensitive area involvement. The primary endpoint in the study, IGA status clear/almost clear at Week 6 was met by 27.2% patients with steroid sensitive areas (P =.007 vs vehicle), 22.3% (P =.026), and 6.3% on roflumilast 0.3%, roflumilast 0.15%, and vehicle, respectively; relative to 30.1% (P =.026), 24.1% (P =.098), and 12.0% patients without steroid-sensitive areas. Among patients with baseline WI–NRS score ≥4, 73.5%, 55.6%, and 32.6% of those with steroid-sensitive areas and 45.9%, 72.7%, and 23.7% of those without steroid-sensitive areas achieved a 4-point reduction with roflumilast 0.3%, 0.15%, or vehicle at Week 12. PSD improvement from baseline at Week 12 for patients with steroid-sensitive areas was -48.3 (P ˂.001), -43.1 (P =.012), and -24.9, and for patients without steroid-sensitive areas -35.7 (P =.003), -44.6 (P ˂.001), and -17.1. Most treatment emergent adverse events were mild to moderate and there was no evidence of local irritation. Once-daily roflumilast cream was well tolerated with significant improvements in investigator and patient assessed PsO outcomes in patients with steroid-sensitive area involvement on the face, neck, or intertriginous areas

Long-term safety and efficacy of risankizumab for the treatment of moderate-to-severe plaque psoriasis : Interim analysis of the LIMMitless open-label extension trial up to 5 years of follow-up

Psoriasis is a chronic, inflammatory skin disease often requiring long-term therapy. To evaluate the long-term safety and efficacy of risankizumab in patients with psoriasis. Methods: LIMMitless is an ongoing phase 3, open-label extension study evaluating the long-term safety and efficacy of continuous risankizumab 150 mg every 12 weeks for adults with moderate-to-severe plaque psoriasis following multiple phase 2/3 base studies. This interim analysis assessed safety (ie, monitored treatment-emergent adverse events [TEAEs]) through 304 weeks. Efficacy assessments included determining the proportion of patients who achieved ≥90% or 100% improvement in Psoriasis Area and Severity Index (PASI 90/100), static Physician's Global Assessment of clear/almost clear (sPGA 0/1), and Dermatology Life Quality Index of no effect on patient's life (DLQI 0/1) through 256 weeks. Among 897 patients randomized to risankizumab in the base studies, 706 were still ongoing at data cutoff. Rates of TEAEs, TEAEs leading to discontinuation, and TEAEs of safety interest were low. At week 256, 85.1%/52.3% of patients achieved PASI 90/100, respectively, 85.8% achieved sPGA 0/1, and 76.4% achieved DLQI 0/1. Limitations: Open-label study with no placebo or active-comparator group. Long-term continuous risankizumab treatment for up to 5 years was well tolerated and demonstrated high and durable efficacy

Incommensurate ground state of double-layer quantum Hall systems

Double-layer quantum Hall systems possess interlayer phase coherence at sufficiently small layer separations, even without interlayer tunneling. When interlayer tunneling is present, application of a sufficiently strong in-plane magnetic field $B_\parallel > B_c$ drives a commensurate-incommensurate (CI) transition to an incommensurate soliton-lattice (SL) state. We calculate the Hartree-Fock ground-state energy of the SL state for all values of $B_\parallel$ within a gradient approximation, and use it to obtain the anisotropic SL stiffness, the Kosterlitz-Thouless melting temperature for the SL, and the SL magnetization. The in-plane differential magnetic susceptibility diverges as $(B_\parallel - B_c)^{-1}$ when the CI transition is approached from the SL state.Comment: 12 pages, 7 figures, to be published in Physical Review

Psoriatic Arthritis and Burden of Disease: Patient Perspectives from the Population-Based Multinational Assessment of Psoriasis and Psoriatic Arthritis (MAPP) Survey

Introduction: Psoriatic arthritis (PsA) is underdiagnosed and has a substantial impact on quality of life, disability, and work productivity. The population-based Multinational Assessment of Psoriasis and Psoriatic Arthritis (MAPP) survey examined the impact of PsA on patients’ activities of daily living and unmet treatment needs. Methods: This large-scale, random digit dialing, telephone survey of patients self-reporting a diagnosis of psoriasis and/or PsA was conducted in North America and Europe. Results: In all, 3426 patients participated in the survey, including 712 (21%) who identified themselves as having PsA. Over half of the patients reported severe PsA involving more than four joints. Eighty-three percent of patients with PsA visited a health-care provider within the past 12 months. Approximately one-quarter saw their primary care provider or dermatologist most often for their disease; 37% responded that their rheumatologist was the health-care provider seen most often for PsA. Patients with PsA reported a substantial impact of disease on physical function. One-third of patients with PsA reported missing work because of their disease and PsA impacted their ability to work full time. Over half of the patients with PsA (58%) reported receiving no treatment or topical therapy only, leaving their joint disease untreated. Factors associated with lack of adherence were perceived lack of efficacy and concerns about long-term safety. Conclusions: The MAPP survey confirms that PsA has a significant impact on physical function and activities of daily living. Undertreatment of PsA suggests a need for improved screening and diagnosis as well as education about treatment options and adherence