VISFATIN LEVEL DISTURBANCES IN PERIPHERAL BLOOD OF PATIENTS WITH DIABETIC NEPHROPATHY

Introduction. Recent studies suggest that visfatin participates in pathogenesis of vascular diabetic complications, in particular diabetic nephropathy (DN). The aim of the present research - definition of visfatin level in peripheral blood of type 2 diabetic patients taking to account renal function disturbances and body mass index (BMI). Materials and methods. 94 type 2 diabetic patients with different stages of DN and 10 healthy subjects (control group) were observed. Visfatin concentration in blood plasma was determined using immunoassay kit. Results. An essential increase of visfatin level in blood plasma took place already in initial stages of the DN. Progressing of the disease was accompanied by more expressed growth of visfatin concentration. In patients with high BMI substantial increase of visfatin level when compared with those with normal IMT was determined. We established strong correlations between visfatin concentrations, urinary albumin levels and blood creatinine concentrations and negative correlations with glomerular filtration rate. Conclusions: Our findings testify that visfatin level displays a functional kidney state and may be used as addition to traditional methods of patients examination

The formation of J-aggregates in solutions of reverse micelles

Features of BIC J-aggregate formation in AOT reverse micelles have been studied using steady-state absorption and luminescence spectroscopy and time-resolved luminescence spectroscopy. BIC J-aggregates reveal spherical structure with diameter ~ 20 nm and significant thermal stability. RM diameter decrease results in strong static disorder increase leading to J-aggregate band (J-band) widening and luminescence quenching. Due to high thermal stability BIC J-aggregates are embedded into RM as a whole at any temperatures of stock water solution. Decrease of stock water solution temperature leads to J-band narrowing and intensity increasing due to static disorder decreasing

Features of J-aggregates formation in pores of nanostructured anodic aluminum oxide

Features of J-aggregates formation in highly structured pores of anodic aluminum oxide (AAO) have been studied using steady-state absorption and luminescence spectroscopy and time-resolved luminescence spectroscopy. J-aggregates with different structures (spherical and thread-like) were chosen for the studying. Spectroscopic investigations show the presence of both types of the J-aggregates in the AAO pores. It leads to a static disorder increasing in the J-aggregates. Besides, in the case of the thread-like J-aggregates changes in the structure have been supposed also

Features of exciton migration in pseudoisocyanine J-aggregates

Exciton migration in pseudoisocyanine (PIC) J-aggregates has been studied via luminescence quenching by an exciton trap. It has been shown that in PIC J-aggregates excitons migrate by coherent mechanism. Exciton diffusion coefficient and diffusion length have been obtained using classical approach developed for molecular crystals. Both of them are much smaller in comparison with exciton diffusion parameters for molecular crystals

Cyanine dye excimer formation in nanoporou SiO₂ matrices

Novel red-shifted band has been observed in luminescence spectra of a cyanine dye embedded into nanoporous SiO₂ matrix. That band is concentration dependent and disappears at cooling to low temperature. It has been associated with the dye excimer formation due to strong interaction with the pores surface

Fluorescence of cyanine dye excimers in nanoporous silica

Adsorption of cyanine dye DiI in a nanopous SiO₂ matrix has been studied. It was shown that the increase of the dye concentration in the SiO₂ matrix provokes the appearance of an additional red-shifted band of excimer nature in the dye fluorescence spectrum without any changes in the absorption one. Static character of the dye excimer formation was revealed. Enhanced dye concentration due to spatial confinement in a nanopore volume has been supposed as a reason of the effective excimer formation

Exciton migration in pseudoisocyanine J-aggregates formed in polymer films

Exciton transport efficiency in pseudoisocyanine (PIC) J-aggregates formed in PVA thin film has been studied using an exciton trap. As a trap, anionic cyanine dye DiD-C3S has been used. Luminescence spectra have been obtained using luminescence microscope that allows us to collect the spectra from very small areas within the film. Heterogeneous dye distribution has been found. Using Stern-Volmer equation for the J-aggregate luminescence quenching by the trap, it has been found that 50 % J-aggregate luminescence is quenched at the ratio PIC/DiD-C3S = 30:1. The obtained value is very small and points to the exciton migration over rather small distances.Вивчено ефективність екситонного транспорту в J-агрегатах псевдоізоціаніну (РІС), сформованих у тонких плівках ПВС, за допомогою екситонної пастки. В якості пастки використано аніонний ціаніновий барвник DiD-C3S. Спектри люмінесценції отримано за допомогою люмінесцентного мікроскопа, що дозволило збирати спектри з дуже маленьких ділянок плівки. Виявлено неоднорідний розподіл барвників у плівці. Використовуючи рівняння Штерна-Фольмера для гасіння люмінесценції J-агрегатів паст-кою, показано, що 50 % люмінесценції J -агрегатів гаситься у співвідношенні PIC/DiD-C3S = 30:1. Отримане значення е дуже малим й указує на міграцію екситонів на невеликі відстані.Изучена эффективность экситонного транспорта в J-агрегатах псевдоизоцианина (PIC), сформированных в тонких пленках ПВС, при помощи экситонной ловушки. В качестве ловушки использован анионный цианиновый краситель DiS—C3S. Спектры люминесценции получены при помощи люминесцентного микроскопа, что позволило собирать спектры с очень маленьких участков пленки. Обнаружено неоднородное распределение красителей в пленке. Используя уравнение Штерна-Фольмера для тушения люминесценции J-агрегатов ловушкой, показано, что 50 % люминесценции J-агрегатов тушится в соотношении PIC/DiD-C3S = 30:1. Полученное значение очень мало и указывает на миграцию экситонов на малые расстояния

Using cyanine dye J-aggregates as luminescence probe for nanostructured media

Due to excitonic nature of electronic excitations in J-aggregates causing the unique spectral properties they successfully applied as luminescent probes in biology. In present report we demonstrate a possibility using J-aggregates as the probe for nanostructured materials basing on BIC J-aggregates. As the probing tool the exciton delocalization length has been used as well as the lifetime. It has been shown direct dependence of the exciton characteristics of the J-aggregates on the specific features of solid matrices such as nanoporous matrix and polymer films

GdVO₄:Eu³⁺ nanoparticles - embedded CaCO₃ microspheres: synthesis and characterization

In present study, we report on synthesis of fluorescent GdVO₄:Eu³⁺ nanoparticle-embedded CaCO₃ microparticles (CaCO₃@GdVO₄:Eu³⁺) and their characterization. Synthesized CaCO₃@GdVO₄:Eu³⁺ microspheres are of vaterite polymorph and about 2 µm diameter with -12.80±0.82 mV zeta potential. The specific surface area of the CaCO₃@GdVO₄:Eu³⁺ microspheres and pore size distribution were analyzed by Brunauer-Emmett-Teller method. The microparticles was classified as macroporous ones with a wide distribution of pore sizes.The specific surface area for CaCO₃@GdVO₄:Eu³⁺ microspheres (Sbet = 25.2 m²/g) is higher than reported for CaCO₃ microparticles obtained without any additives. CaCO₃@GdVO₄:Eu³⁺ microspheres exhibit strong fluorescence both in a water solution and under fluorescent microscopy conditions that makes them attractive for bio-related application