We show that the organic salt 4-N,N-dimethylamino-4′-N′-methyl-stilbazolium tosylate (DAST) is a very interesting material for electro-optic applications in the near infrared. The electro-optic coefficients, namely r111, r221, r331, r113, r223, and r333, were determined in the spectral range of 700 up to 1535 nm using optical samples cut from large high quality bulk crystals. DAST combines large electro-optic coefficients, e.g., r111=77±8 pm/V at λ=800 nm and r111=47±8 pm/V at λ=1535 nm, with low dielectric constants, e.g., ε1=5.2±0.4. This combination leads to large polarization-optical coefficients.

Compared to 2-pill therapy, a FDC resulted in important increases in patient adherence. Economic analyses are warranted to determine whether the clinical benefits attributable to the adherence gains are worth the incremental cost of a FDC.

Organic materials with large second-order nonlinear optical (NLO) susceptibilities are of interest because of their potential applications in optical signal processing and frequency conversion.['-31 Much work has therefore been devoted to the search for optimal molecular crystalline materials composed of stable chromophoric molecules with large molecular hyperpolarizabilities with an optimized orientation for large macroscopic NLO effects.Crystal growth research is of basic importance for the application of organic crystals in NLO and electro-optical devices.I4] Bulk crystalline samples of reasonable size and good quality are also essential for the accurate measurement of electro-optical and NLO coefficients in order to evaluate the potential for future applications. In addition, it has been found that, particularly in organic materials, the linear electro-optical responses are strongly dependent on the crystal quality.[" Furthermore, growth of bulk crystals of organic salts with large chromophoric cations has hardly been reported in the literature. In this work, we describe the growth of the organic salt crystal 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium tosylate (DAST), and the main results of the linear, nonlinear, and electro-optical characterization.In this crystal, the stilbazolium, one of the most efficient NLO chromophores, is the nonlinear optically active part.[61 The anion (tosylate) induces the non-centrosymmetric macroscopic crystal packing (see Fig. 2, bottom). DAST crystals have already been reported to have very large nonlinear optical su~ceptibilities.[~-~~~ The lack of reasonably large and optically homogeneous DAST crystals has hindered the accurate linear, nonlinear, and electro-optical characterization in earlier investigations of DAST.[*-'O1 DAST was synthesized by the condensation of 4-methyl-N-methyl pyridinium tosylate, which was prepared from 4-picoline and methyl toluenesulphonate, and 4-N,N-dimethylamino-benzaldehyde in the presence of pipendine (Scheme 1).DAST was then purified ( > 99.8 %) by recrystallization from water and methanol. Orange co-crystals, DAST . H20, in space group Pi (point group i, z = 2)[l2]were obtained from water or a methanol-water mixture. DAST can hardly be dissolved in non-polar and most polar solvents. Alcohol, however, is a reasonably good solvent for DAST and we found that methanol was the most suitable solvent for the growth of high-quality DAST crystals. The solubility curve for DAST in a methanol solution (see Fig. 1) was defined by saturating solutions at a high temperature and slowly cooling the solution in the presence of a precipitated solid to maintain equilibrium and analyzing the solution at defined temperatures.DAST single crystals were grown from a seeded saturated methanol solution (between 40 and 50°C with concentrations of about 4-5.5 g(DAST)/IOO g(so1vent)) by a 8 . 0 ) . I . , . , . , . , . , .

We report the use of the organic crystal DAST as a freely propagating electromagnetic-wave sensor at terahertz (THz) frequency. We also report the result of using a DAST crystal as a mid-IR THz emitter. Compared with the optical rectification from our best ZnTe emitter, that obtained by use of DAST demonstrates a sixfold enhancement of radiation at 7-20 THz.

We show that the organic salt 4-N,N-dimethylamino-4Ј-NЈ-methyl-stilbazolium tosylate, originally developed for electro-optic applications, is also a very interesting material for phase-matched parametric interactions such as frequency-doubling and optic parametric oscillation in the near infrared. These favorable properties are due to the large off-diagonal element d 26 which gives measured effective phase-matchable nonlinear optical coefficients of d eff ϭ31Ϯ5 and 15Ϯ3 pm/V at the telecommunication wavelengths of ϭ1313 and 1535 nm, respectively.

ObjectiveTo assess the cost-effectiveness of dabigatran etexilate, a new oral anticoagulant, versus warfarin and other alternatives for the prevention of stroke and systemic embolism in UK patients with atrial fibrillation (AF).MethodsA Markov model estimated the cost-effectiveness of dabigatran etexilate versus warfarin, aspirin or no therapy. Two patient cohorts with AF (starting age of <80 and ≥80 years) were considered separately, in line with the UK labelled indication. Modelled outcomes over a lifetime horizon included clinical events, quality-adjusted life years (QALYs), total costs and incremental cost-effectiveness ratios (ICERs).ResultsPatients treated with dabigatran etexilate experienced fewer ischaemic strokes (3.74 dabigatran etexilate vs 3.97 warfarin) and fewer combined intracranial haemorrhages and haemorrhagic strokes (0.43 dabigatran etexilate vs 0.99 warfarin) per 100 patient-years. Larger differences were observed comparing dabigatran etexilate with aspirin or no therapy. For patients initiating treatment at ages <80 and ≥80 years, the ICERs for dabigatran etexilate were £4831 and £7090/QALY gained versus warfarin with a probability of cost-effectiveness at £20 000/QALY gained of 98% and 63%, respectively. For the patient cohort starting treatment at ages <80 years, the ICER versus aspirin was £3457/QALY gained and dabigatran etexilate was dominant (ie, was less costly and more effective) compared with no therapy. These results were robust in sensitivity analyses.ConclusionsThis economic evaluation suggests that the use of dabigatran etexilate as a first-line treatment for the prevention of stroke and systemic embolism is likely to be cost-effective in eligible UK patients with AF.

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Optoelectronic components require materials with large second‐order nonlinearities. Recently, various types of non‐classical chromophores have been developed, in the hope that they have improved physical properties for materials formation. The main research directions and latest developments reviewed here include multi‐dipolar chromophoric assemblies, multiple donor and acceptor chromophores, non‐rod‐shaped dipolar chromophores, and non‐conjugated donor‐acceptor chromophores, in which the charge transfer process is through space instead of the π‐conjugated bridge.