The Size Ellect on the Infrared Spectra of Condensed Media Under Conditions of ID, 2D and 3D Dielectric Confinement

A general expression for the dielectric loss spectrum of an absorbing composite medium was obtained from a Maxwell-Garnett general equation. This expression was simplified for the cases of one, two and three dimensional dielectric confinement in both ordered and disordered thin layers, rods (wires) and spheres of absorbing medium which are considered as mesoparticles or mesoscopic molecules. This theoretical approach was verified experimentally using high purity organic liquids with strong absorption bands in the infrared range. Three organic liquids, namely benzene, chloroform and carbon disulphide, were measured in various dielectric confinement configurations using Fourier Transform Infrared (FTIR) spectroscopy with a Grazing Angle attachment GATRTM. A significant shift of the resonant absorption band of liquid mesoparticles was observed for various dielectric confinement geometries which is in good agreement with theoretical predictions. Possible applications of this work include investigations of industrial smoke, toxic aerosols and liquid droplets

PROGNOSIS, PREVENTION, AND TREATMENT OF DIABETIC CATARACT SURGERY POSTOPERATIVE COMPLICATIONS

Aim. To study immune and antioxidant status of diabetic cataract patients and to assess the efficacy of preoperative preparation for diabetic cataract surgery to prevent intra- and postoperative complications and the efficacy of cataract treatment in metabolic syndrome patients. Patients and methods. 136 cataract patients (272 eyes) were examined (mean age 62±3.2 years). Among these patients, women predominated (n = 74). Control group included 25 healthy volunteers (10 men and 15 women) aged 32‑56 (mean age 44.3±2.4 years) without ocular diseases (50 eyes). Two patient groups were examined. Group 1 included 78 patients (mean age 54±1.5) younger than 60 (52.5 %) with similar lens morphological changes and metabolic disorders who were diagnosed with complicated (diabetic) cataract. Group 2 included 58 patients with age-related cataract. Tear, anterior chamber (AC) humor, and blood tests were performed. Immune status, lipid peroxidation parameters in tear fluid and blood, active peroxiredoxin 6 (PRDX6) and / or its breakdown fragments in tear fluid and AC humor were studied. In group 1 (age-related cataracts), somatic disorders were diagnosed in 4.5 % of cases, in group 2 (complicated cataracts), somatic disorders were diagnosed in 100 % of cases. Expression of protective enzymes against oxidative stress in tear fluid was studied. Activity of tear antioxidant enzymes under oxidative stress conditions in therapy and after cataract surgery was evaluated. Results. Postoperatively, increase in PRDX6 level was revealed in age-related cataract patients. The absence of phaco complications confirms these findings. In complicated (diabetic) cataracts, PRDX6 level was 6‑times less than in age-related cataracts. Conclusions. Prophylaxis of inflammatory complications in age-related cataract patients can be performed using the following schedule: 0.5 % levofloxacin 4 times daily, bromfenac once daily

ROLE OF PURINE METABOLISM ENZYMES IN IMMUNE PATHOGENESIS OF FIBRO-CAVERNOUS PULMONARY TUBERCULOSIS

Emergence and development of pulmonary tuberculosis is often accompanied by the signs of immune system dysfunction. The key enzymes of purine metabolism, e.g., adenosine deaminase (ADA and its isoforms, i.e. ADA1, ADA1 protein complex, and ADA-2), ecto-5’-nucleotidase (5’-NC) controlling adenosine levels, may play an important role in regulation of cell-mediated immunity. We have correlated the parameters of purine metabolism with cytokine production in patients with fibro-cavernous pulmonary tuberculosis (FCT) with a severe specific process. Our studies have revealed an association between cytokine production and purine metabolism indexes, thus reflecting an important role of the latters in immunopathogenesis of the hyperchronic specific disorder. It is mainly referred to adenosine deaminase (ADA1 and ADA2) which are antagonistic in regulation of IL-17 and IL-18. A significantly decreased activity of intracellular ADA1, lowered CD26 concentrations, with lacking intercorrelation, along with increased activity of ecto-ADA-2 is, generally, typical to patients with fibrous-cavernous tuberculosis, thus being a possible marker for prediction of unfavorable hyperchronic specific process, being consistent with functional depletion of immunocompetent cells. Lack of the ADA/ectopeptidase complexes leads to an imbalance between adenosine supply and its deamination. Increased extracellular adenosine concentrations in the patients with severe specific processes may cause metabolic alterations of immunocompetent cells, thus complicating clinical course of the disease, e.g., contributing to enhancement and progression of pulmonary fibrosis

Double Quantum Dot Photoluminescence Mediated by Incoherent Reversible Energy Transport

We present a theoretical study of the stationary photoluminescence of two, direct-gap, semiconductor nanocrystals, taking into account electronic excitation energy-transfer processes due to electrostatic interaction. The results obtained here allow for the incoherent reversible energy transport that occurs when the intraband relaxation rate in a quantum dot acceptor is comparable to, or less than, the energy-transfer rate. We investigate the secondary emission of two different electronic level schemes that can be realized experimentally, obtain analytical expressions for the luminescence differential cross section, and perform an analysis of its spectrum. It is shown that when excitation is not in resonance with the levels involved in energy transfer, the energy transfer is more efficient

Effect of ZnS shell thickness on the phonon spectra in CdSe quantum dots

International audienceThe evolution of the optical phonon spectra of colloidal core/shell CdSe/ZnS quantum dots with an increase of the shell thickness from 0.5 to 3.4 monolayers has been studied by resonant Raman spectroscopy. The results obtained suggest that the ZnS shell changes its structure from amorphous to partly crystalline as the thickness increases. Simultaneously, an increase in Raman scattering by surface (core/shell interface) phonons and the redshift of the corresponding phonon band have been observed and assigned to variations in the shell structure. The disorder present in the shell provides a major contribution to the line shape of the Raman spectra at higher ZnS coverage. A method to control the quality of quantum dots based on Raman spectroscopy is proposed

Ultrasonic and scintigraphic monitoring of thyroid residue after operation of various volume on thyroid gland

The 105 patients were undergone the medical observation after operations of various volume on thyroid gland. The patients were divided into 3 groups — patients without additional changes (n = 74), with nodes in residual tissue (n = 20), patients with glandular tissue after thyreoidectomy (n = 11). The amount of relapses was increasing with prolongation of postoperative period. For specification of relapsing nodules and thyroid residue spreading after thyreoidectomy the complex radiological examination is proposed