Photostability enhancement of InP/ZnSe/ZnSeS/ZnS quantum dots by plasmonic nanostructures.

The effect of gold and silver plasmonic films on the photoluminescence and photostability of InP/ZnSe/ZnSeS/ZnS nanocrystals (quantum dots) is reported. Colloidal gold films promote the photostability enhancement of InP/ZnSe/ZnSeS/ZnS quantum dots (more durable emission properties in the presence of metal nanostructures) through reducing exciton lifetime. In contrast, silver decreases the photostability of InP/ZnSe/ZnSeS/ZnS quantum dots without changing the photoluminescence intensity and kinetics. By adjusting the excitation wavelength closer to the extinction band of gold nanoparticles a 1.8-fold enhancement of luminescence intensity has been obtained using a polyelectrolyte spacer between the metal and InP/ZnSe/ZnSeS/ZnS nanoparticles. Thus, plasmonics offers essential practical improvement of light emitters in terms of their durable luminescent properties upon prolonged optical excitation without losses in luminescence efficiency or even along with increased efficiency.

[COMPLEX IMMUNOGLOBULIN PREPARATION FOR THERAPY OF PERTUSSIS IN YOUNG CHILDREN].

AIM: Study the possibility of inclusion of complex immunoglobulin preparation (CIP) pos- sessing specific activity against pertussis exotoxins into complex therapy of pertussis infection in young children. MATERIALS AND METHODS: -2 groups of children with.pertussis younger than 3 years were examined. The main group (50 individuals) received CIPper os - 1 dose 1 - 2 times per day for 5 days, comparison group (34 children) received only basic therapy. Evaluation of clinical effectiveness of CIP was carried out, the content of anti-pertussis class G antibodies and total IgE in patients were studied. RESULTS: A good clinical effectiveness of the preparation was shown, as well as immune modulating activity against humoral immune response to pertussis infection. CONCLUSION: The detected positive effect of CIP on pertussis -course in children has indicated a principally novel use of this per oral drug form.

Interfacial properties of cetyltrimethylammonium-coated SiO(2) nanoparticles in aqueous media as studied by using different indicator dyes.

In this paper, we compare the properties of SiO(2)/water interface modified by cetyltrimethylammonium bromide (CTAB) with those of CTAB spherical micelles. The suspension of uniform silica nanoparticles coated with CTAB adlayer was investigated by using a set of acid-base indicators. The study of the colloidal system has been provided using electron microscopy and dynamic light scattering methods; the diameter of the initial SiO(2) particles in dried state was ca. 40 nm. The increase in the zeta-potential value of nanoparticles from -34 to +(37-54) mV on going from pure silica suspension to the CTAB-containing system points on the silica surface recharging and formation of surfactant bilayer (or multilayer) on the silica/water interface. To obtain further information about the interfacial surfactant adlayer, the behavior of different indicator dyes has been studied in CTAB-modified SiO(2) suspension. Comparison of the indices of apparent ionization constants, i.e., pK(a)(a) values of phenol red, bromothymol blue, and fluorescein with those determined in CTAB micellar solutions have confirmed the supposition about certain similarity between CTAB-covered silica nanoparticles and common spherical surfactant micelles. However, the experiments on kinetics of bromophenol blue fading, as well as the spectral properties of methyl orange and solvatochromic Reichardt's indicator and some other data revealed the specificity of surfactant-coated silica nanoparticles, presumably, originating from their surface morphology.

Isolation of the C3 complement component and its C3d subunit from IY-1 fraction of Cohn's fractionation of human plasma.

C3 complement component and its C3d subunit were isolated from the IY-1 Cohn's fraction, which is the waste of industrially produced albumin and immunoglobulins. The first step was the fractionation of precipitate IY-1 by polyethylene glycol (PEG) 4000 to a final concentration of 16% PEG. The precipitate formed was separated by centrifugation. The supernatant contained the C3d subunit of C3, and the redissolved 16% PEG precipitate contained the C3 component. Then the supernatant and the dissolved precipitate were subjected to anion-exchange chromatography on DEAE-Toyopearl 650 M. In the last step fractions containing C3 and C3d concentrated by ultrafiltration were chromatographed on Sephacryl S-200.