Introduction. Chronic inflammatory demyelinating polyneuropathy (CIDP) is characterized by long-term progressive or relapsing course, neurological deficit, and disability of varied severity. The course of CIDP after specific therapy and, if necessary, long-term maintenance treatment are to be studied. Objective: To evaluate CIDP clinical and history characteristics over the long-term follow-up ( 5 years), to compare long-term CIDP course in a number of clinical variants and onset types, and to determine clinical predictors of unfavorable CIDP course. Materials and methods. The study included 45 patients diagnosed with CIDP based on EAN/PNS 2021 criteria lasting for 5 or more years. Retrospective collection and analysis of medical records and clinical history were performed. Internationally accepted scales were used to assess neurological deficit (NIS, MRCss), disability (INCAT), and disease activity status (CDAS). The criteria of unfavorable course were developed to evaluate factors affecting CIDP course. Results. Among the patients with CIDP history of 5 years, each third (34%) had no neurological deficit and remained in long-term clinical remission (CDAS 1). The vast majority (90%) responded to first-line therapy in early disease, while only 53% of patients required maintenance treatment in 5 or more years of the onset. With the developed criteria (poor response to glucocorticosteroids (GCS), need for maintenance therapy, and CDAS 3–5), unfavourable CIDP course was detected in 24 (53.3%) participants. Its probability increased in later onset (47 [30; 50] years), the chronic type of onset, and delayed specific therapy. The most significant predictors included low total NIS score at onset (60 points) and multifocal CIDP. Conclusions. The course of typical CIDP is relatively favorable if timely diagnosed, and pathogenetic treatment initiated. Patients with acute and subacute onset demonstrate the best long-term status. The predictors of unfavourable disease course include mild neurological deficit at onset (NIS total score 60 points) and multifocal CIDP.

The third-order susceptibility of vinylidene fluoride-trifluoroethylene (VDF-TrFE) copolymer are analyzed by using the z-scan technique with a nanosecond laser as an excitation source. It is established that optical transmittance of the VDF-TrFE samples decreases after their polarization in an electric field.

The photovoltaic properties and the bulk photovoltaic effect have been studied in a polyvinylidene difluoride–trifluoroethylene polymeric ferroelectric doped by single-walled nanotubes and a ruthenium-based dye. The dopants serve as spectral sensibilizers that improve sensitivity to 532-nm laser radiation.

Composites with photoelectrical, nonlinear optical, and photorefractive properties have been prepared. The composites consist of polyvinyl alcohol, single-wall carbon nanotubes, and fullerene C-60. Addition of C-60 with a long wavelength boundary near 630 nm resulted in an eight- to tenfold increase in both the quantum efficiency of generation of mobile hole charges and the photorefractive two beam gain coefficient measured at wavelengths exceeding 1000 nm (over an area of optical absorption of nanotubes). This is attributed to electron trapping by acceptor fullerene, which limits the regeneration of photogenerated charges and provides an increase in mobile hole charges.

AbstractThe photoconductive, photorefractive and nonlinear optical properties of composites from polyvinylcarbazole or aromatic polyimide containing supramolecular ensembles of (tetra-15-crown-5) - phthalocyaninato gallium, indium, - phthalocyaninateacetato yttrium, - phthalocyaninato ruthenium with axially coordinated pyrazine molecules were investigated at 633, 1030 and 1064nmusing continuous and pulsed lasers. Supramolecular ensembles (SE) were prepared through dissolution of molecular metallophthalocyanines in tetrachloroethane (TCE) and subsequent treatment via three cycles of heating to 90∘C and slow cooling to room temperature. The zscan method in femtosecond and nanosecond regimeswas used for measuring nonlinear optical properties phthalocyaninato indium and yttrium in TCE solutions and polymer films. It was established that effect of heavy metallic atom is basic factor which determines the quantum yield, photorefractive amplification of laser object beam, dielectric susceptibility of third order and nonlinear optical properties of metallophthalocyanines.

Measurement of the photoelectric and photorefractive characteristics of 2,3,9,10,16,17,23,24-tetra(15-crown-5)phthalocyaninatoacetatoyttrium(III) [(15C5)4Pc]Y(OAc) has made it possible to reliably establish the features of decrease in the quantum yield of generation of charge carriers φ0 and photorefractive two-beam coupling gain Γ with an increase in the atomic weight of the central metal in a series of related gallium(III), yttrium(III), ruthenium(II), and indium (III) phthalocyaninates. These features can be due to an increase in the spin-orbit interaction constant with increasing atomic weight of the central metal, a change that leads to an increase in both the contribution of triplet excited associates to the formation of mobile charge carriers and the rate of the reverse reaction T 1 → S 0, which effectively inhibits the formation of charge carriers through the excited triplet state. The measurement of photoelectric and photorefractive characteristics at 1064 nm has shown that the quantum yield of electron-hole pairs in the composite polyvinylcarbazole/supramolecular assemblies of yttrium complex is φ0 = 0.6 and the two-beam coupling gain coefficient Γ is about 35 cm−1 at E 0 = 120 V/μm. The dielectric susceptibility measured by the z-scan technique in a solution of the yttrium complex in tetrachloroethane (1 mg in 1 mL) is χ(3) = 4.2 × 10−10 esu.

The photorefractive effect is demonstrated for the first time for the composite consisting of a ferroelectric material (polyvinylidenefluoride-trifluoroethylene) and single-walled carbon nanotubes that serve as nonlinear optical chromophores and, simultaneously, spectral sensitizers for the laser radiation with a wavelength of 1064 nm. It is demonstrated that the internal field in the ferroelectric material makes it possible to measure the photorefractive effect in the absence of the external field.

Photoelectric, nonlinear optical, and photorefractive properties of hybrid composite materials based on polyvinylcarbazole (PVK) and indium(III) 2,3,9,10,16,17,23,24-tetra(15-crown-5)phthalocyaninate [(15C5)4Pc]In(OH) are studied in detail. Field dependence of the quantum efficiency in a 7.8 μm-thick layer containing 5 at % [(15C5)4Pc]In(OH) is measured. The best approximation of the quantum efficiency with Onsager’s equation corresponds to a quantum yield of thermalized electron-hole pairs φ0 = 0.01 at initial separation r 0 = 9.8 Å. Z-scan measurements in a nanosecond range showed that the electric susceptibility of [(15C5)4Pc]In(OH) solution in tetrachloroethane (TCE) with a concentration of 7 × 10−4 mol/L is χ(3) = 1.34 × 10−9 esu. The maximum coupling gain coefficient found for the material composed of PVK and 5 wt % [(15C5)4Pc]In(OH) at an electric-field intensity of 200 V/μm is Γ = 80 cm−1, and the difference between the coupling gain and absorption coefficients is Γ − α = 70 cm−1. The dependence of the coupling gain coefficient on the intensity ratio of interfering beams 1 and 2 (β = I 1(0)/I 2(0)) in a composite containing 3 wt % [(15C5)4Pc]In(OH) is measured. An increase in β was attained by decreasing intensity of the signal beam I 2(0) at constant intensity of the pump beam I 1(0) = 0.15 W/cm2 and E 0 = 214 V/μm. Within the initial segment of the curve, the coupling gain coefficient increases from 30 to 60 cm−1; then, the coefficient drops almost to the initial value. The data obtained show that the composite materials studied can be used in practice for correcting faded images. The combined analysis of the results obtained and similar data for gallium and ruthenium tetra-15-crown-5-phthalocyaninate complexes revealed the regularities in the change of the quantum yield of thermalized electron-hole pairs and the photorefractive coupling gain coefficient in a series of complexing metals: gallium(III), ruthenium(II), and indium(III). An increase in the molecular weight of the central metal atom is found to result in a substantial decrease in Γ and φ0 due to the increase in the spin-orbit coupling constant.

The photoelectric and photorefractive characteristics of polyvinylcarbazole (PVK) composites with 0.15 wt % graphene at a wavelength of 532 nm have been measured. The dependence of the quantum efficiency of generation of mobile charge carriers as determined from the photocurrent is well approximated by the Onsager equation calculated accurate to E 0 3 for the quantum yield of thermalized electron-hole pairs of φ 0 = 1 and their initial separation radius of r 0 = 10.9 Å. The long-wavelength edge of optical absorption for PVK lies at 365 nm. Thus, the photogeneration of mobile carriers during illumination of the composite at 532 nm is due to photoexcitation of graphene. The measurement of the photorefractive properties has revealed that the two-beam coupling gain coefficient is Γ = 50 cm −1 at E 0 = 150 V/μm and equal intensities of incident beams. It has been found that at E 0 = 83.3 V/μm, the two-beam coupling gain coefficient increases from 8 to 14 cm −1 as the ratio of incident beam intensities I 1 (0)/ I 2 (0) increases from 1 to 2.4.

В работе рассматриваются подходы к формированию полимерных нанокомпозитов на основе тетрапиррольных соединений с фотоэлектрическими, нелинейно-оптическими и фоторефрактивными свойствами. Показано образование супрамолекулярных ансамблей комплексов Ru(II) и Ga(III) с тетра-15-краун-5-фталоцианином при формировании тонких пленок из тетрахлорэтановых растворов, которые подвергались нескольким циклам процессов нагревания и последующего медленного охлаждения. Формирование супрамолекулярных ансамблей на поверхности изучено методом атомной силовой микроскопии. Установлено, что образование ансамблей обуславливает появление фотоэлектрической и фоторефрактивной чувствительности в ближней ИК области (измерения проведены при 1064 нм и 1550 нм). В композитах из ПВК и ансамблей комплексов Ga(III) измеренный при 1064 нм квантовый выход термализованных электрон-дырочных пар в 20 раз превышает значения, полученные в композитах на основе комплексов Ru(II). Максимальный коэффициент двулучевого усиления при 1064 нм ( = 120 см-1 при поле Е0 = 120 В/мкм) также получен в композите на основе комплексов Ga(III). Диэлектрическая молекулярная восприимчивость третьего порядка, измеренная в растворе комплексов в ТХЭ, слабо зависит от природы центрального атома и от аксиального окружения и лежит в пределах = 4 5.2 ? 10-32 esu.

Techniques of the production of polymer nanocomposites based on tetrapyrrole compounds with photoelectric, nonlinear optical, and photorefractive properties are considered. Supramolecular ensembles of Ru(II) and Ga(III) complexes with tetra-15-crown-5-phthalocyanine are found to form upon the deposition of thin films from tetrachloroethane solutions that have undergone several cycles of heating followed by slow cooling. The surface formation of supramolecular ensembles is studied with the use of atomic force microscopy. The assemblage is found to give rise to photoelectric and photorefractive sensitivity in the near-infrared range (measurements were carried out at 1064 and 1550 nm). The quantum yield of thermalized electron-hole pairs at 1064 nm in composites of polyvinyl carbazole and assembled Ga(III) complexes is 20 times as high as that in composites based on Ru(II) complexes. The largest two-beam coupling gain coefficient at 1064 nm (Γ = 120 cm−1 at E 0 = 120 V/μm) was also observed for the Ga(III)-complex-containing composite. The third-order dielectric molecular susceptibility measured in tetrachloroethane solutions of the complexes weakly depends on the nature of the central atom and its axial neighborhood and falls in a range of γ = 4−5.2 × 10−32 esu.

The photoelectric and photorefractive characteristics of composites based on poly(vinylcarbazole) containing crown-substituted ruthenium phthalocyanine with axially coordinated pyrazine molecules, (R4Pc)Ru(pyz)2 (where R4Pc−2 is [4,5,4′,5′,4″,5″,4″′,5″′-tetrakis-(1,4,7,10,13-pentaoxatridecamethylene)phthalocyanine ion], pyz is pyrazine), have been studied. Supramolecular ensembles of these complexes are responsible for optical absorption and photoelectric and photorefractive sensitivity in the near IR region. It has been found that under the action of a 1064-nm laser, the quantum efficiency of formation of mobile charge carriers, estimated from the photocurrent, corresponds to the Onsager equation when the quantum yield of formation of thermalized electron-hole pairs φ0 = 0.35 and the separation distance is 9.8 Å, irrespective of the (R4Pc)Ru(pyz)2 content. The kinetic curves of amplification of the information laser beam are bellshaped. This suggests that the photorefractive characteristics are underestimated owing to lowering to zero of the field E 0 inside the layer as a result of buildup of space charge in the near-electrode space upon passing the dark current. The two-beam gain coefficient at an (R4Pc)Ru(pyz)2 content of 7 wt % is Γ = 62 cm−1 as estimated from the maximum of the bell-shaped curve.