Purcell effect in active diamond nanoantennas.

We suggest a novel class of active nanoantennas based on diamond nanoparticles with embedded nitrogen-vacancy centres coupled to Mie resonances of nanoparticles. We theoretically study the optical properties of such nanoantennas including the field enhancement and Purcell effect, and experimentally demonstrate the enhancement of the fluorescence rate of the emitters due to particle resonances, as compared to a nonresonant regime. Our results pave the way towards active dielectric nanophotonics for quantum light sources, bioimaging, and quantum information processing.

Nanoscale Generation of White Light for Ultrabroadband Nanospectroscopy.

Achieving efficient localization of white light at the nanoscale is a major challenge due to the diffraction limit, and nanoscale emitters generating light with a broadband spectrum require complicated engineering. Here we suggest a simple, yet highly efficient, nanoscale white-light source based on a hybrid Si/Au nanoparticle with ultrabroadband (1.3-3.4 eV) spectral characteristics. We incorporate this novel source into a scanning-probe microscope and observe broadband spectrum of photoluminescence that allows fast mapping of local optical response of advanced nanophotonic structures with submicron resolution, thus realizing ultrabroadband near-field nanospectroscopy.

Resonant silicon nanoparticles for enhancement of light absorption and photoluminescence from hybrid perovskite films and metasurfaces.

Recently, hybrid halide perovskites have emerged as one of the most promising types of materials for thin-film photovoltaic and light-emitting devices because of their low-cost and potential for high efficiency. Further boosting their performance without detrimentally increasing the complexity of the architecture is critically important for commercialization. Despite a number of plasmonic nanoparticle based designs having been proposed for solar cell improvement, inherent optical losses of the nanoparticles reduce photoluminescence from perovskites. Here we use low-loss high-refractive-index dielectric (silicon) nanoparticles for improving the optical properties of organo-metallic perovskite (MAPbI3) films and metasurfaces to achieve strong enhancement of photoluminescence as well as useful light absorption. As a result, we observed experimentally a 50% enhancement of photoluminescence intensity from a perovskite layer with silicon nanoparticles and 200% enhancement for a nanoimprinted metasurface with silicon nanoparticles on top. Strong increase in light absorption is also demonstrated and described by theoretical calculations. Since both silicon nanoparticle fabrication/deposition and metasurface nanoimprinting techniques are low-cost, we believe that the developed all-dielectric approach paves the way to novel scalable and highly effective designs of perovskite based metadevices.

Note: Near infrared spectral and transient measurements of PbS quantum dots luminescence.

We describe an experimental setup for the characterization of luminescence from nanostructures. The setup is intended for steady-state and time-resolved luminescence measurements in the near-infrared region. The setup allows us to study spectral luminescence properties in the spectral range of 0.8-2.0 µm with high spectral resolution and kinetic luminescence properties between 0.8 and 1.7 µm with a time resolution of 3 ns. The capabilities of the system are illustrated by taking luminescence measurements from PbS quantum dots. We established the size dependencies of the optical properties of the PbS quantum dots over a wide spectral range. Finally, the energy transfer process was studied with a high temporal and spectral resolution.

[Functional changes in the organ of vision and locomotor apparatus in adolescents from the Central Administrative District of Moscow].

The Russian Federation and Moscow also show a global tendency for dysfunctions of the locomotor apparatus (LMA) and the organ of vision (OV) to increase. Eight hundred and two adolescents from the Central Administrative District of Moscow were found to have involvements of LMA (35.4%) and OV (22.5%). There were more common abnormal posture (12.9%), spinal axis changes (11.7%), talpes (12.5%), and myopia (17.8%). The follow-ups made from 1997 to 2002 revealed an increase in the number of adolescents with functional changes (D2) with a decrease in that of apparently healthy adolescents (D1). The changes were prevalent in children born in 1986 onward. Examination of the interaction of LMA and OV as the uniform visual motor system revealed sexual dimorphism suggesting that the girls were more susceptible to these changes, which should be considered while developing a adifferential approach to teaching schoolchildren during pubertal period. Schoolchildren's health status should be systematically considered by a wide circle of specialists to estimate the maximum number of parameters in order to determine the reasons resulting in a steady-state tendency for ODA and OV dysfunctions to progress.

[The health status of 15-18-year-old schoolchildren in Moscow].

Analysis of the health status of about 3 thousand 15-year-old schoolchildren from the Central Administrative District of Moscow, made during annual prophylactic medical examinations during 1994 to 2003, revealed a clear tendency for diminished functional capacities in schoolchildren. There was a less than 30% reduction in the number of apparently healthy adolescents with a rise in the proportion of persons with dysfunctions of the locomotor apparatus (LMA) (24.7%), organ of vision (OV) (21.9%), and gastrointestinal tract (19.2%). Over time there was an increase in the frequency of changes in LMA, OV, and immune system. The revealed correlation and the similarity of the time course of changes during different years of observation between LMA and OV lesions in the examined schoolchildren assume the etiopathogenetic and embryogenetic commonness of their involvement due to the structural and functional unity with connective tissue elements. A functional relationship was assumed to be between OV and LMA, which was due to the visual motor functional system. In-depth studies are required to elucidate reasons for the revealed tendencies.

[Lysozyme of the mollusk Unio pictorum and the sensitivity of alkanotrophic rhodococci to its effect]. / Lizotsim molliuska Unio pictorum i chuvstvitel'nost' k nemu alkanotrofnykh rodokokkov.

A preparation of lysozyme from a freshwater bivalve, Unio pictorum, has been isolated by sorption to chitin, and its physicochemical properties have been studied. An assessment of the sensitivity of 48 strains of rhodococci, belonging to the species Rhodococcus rubber, R. luteus, and R. erythropolis (Specialized Collection of Alkanotrophic Microorganisms of the Institute of Ecology and Genetics of Microorganisms, Ural Division of the Russian Academy of Sciences), which were isolated from diverse natural waters, to lysozyme of the mollusk Unio pictorum demonstrated that the three species differ in their sensitivity to its effects. The high resistance of rhodococci to lysozyme is indicative of their considerable permanence in hydrobiocenoses (and, therefore, ability to maintain self-purification of microbiocenoses from hydrocarbons).

[Conditions for the development of myopia in schoolchildren]. / Ob usloviiakh formirovaniia shkol'noi blizorukosti.

School myopia is a most common health problem in schoolchildren, in adolescents in particular. School myopia resulted from connective tissue failure of the whole organism. Some data, such as the association of school myopia with the HLA system confirm this idea. New investigations in this direction will assist in concretizing the real cause of this type of myopia. The interaction between the lighting conditions and the development of refraction is also of interest.

[Lysozyme of hydrobionts and its role in self-purification of water reservoirs]. / Lizotsim gidrobiontov i ego rol' v protsessakh samoochishcheniia vodoemov.

Model experiments were carried out to study the effects of hydrobiont lysozyme on self-purifying processes of water reservoirs through its participation in the formation of a community of destructive microorganisms. Lysozyme-resistant forms have been found to lie at basis of bacterial cenosis of the Urals, among which there are lysozyme-active and anti-lysozyme-active ones, their population shows an inverse relationship. The exogenous lysozyme that enters the water reservoir in the period when there is a change in the dominant forms of hydrobionts affects the composition of bacterial cenosis by preserving anti-lysozyme-activity with a high activity (6-8 (g/ml), which causes a change in the microbial community of water reservoir, thus affecting the processes of its self-purification. The bacteria having ALA, which do maintain the capacity of a water reservoir for self-clearance from organic substance, persist under the action of endogenous lysozyme of phyto- and zooplankton among saprophytic microorganisms that are destructive agents in the biocenosis.

[Levels of complement components in plasma of onco-hematologic patients with defective hemopoiesis]. / Soderzhanie komponentov komplementa v plazme onkogematologicheskikh bol'nykh pri nedostatochnosti gemopoéza.

Immunochemical assay using monoclonal antibodies was carried out to determine levels of a number of complement components (C3 and its derivatives-C4 and C5) and immunoglobulins (lg) in plasma of patients with onco-hematological diseases involving defective hemopoiesis: leukemia, myelodysplastic syndrome (clonal diseases) or aplastic anemia (delayed clonal disease). The most significant disorders were registered in the concentrations of component C3 and its derivatives. In acute leukemia, the nature and extent of C3 splitting was found to depend on disease while Ig level-on stage. Myelodisplasia usually involved a 2-3-fold decrease in C3 level matched by a rise in the concentrations of its derivatives-C3-like form and C3a fragment. Reduced C3 levels matched by increased ones of Ig were observed in some cases of aplastic anemia. It is suggested that disturbances in complement component level may cause changes in cascade reactions of the complement in onco-hematological patients and thus indirectly influence immune response regulation processes.

[Results of the study of the activity of bone marrow nucleolar organizers in patients with multiple myeloma]. / Rezul'taty izucheniia aktivnosti iadryshkovykh organizatorov kletok kostnogo mozga bol'nykh mnozhestvennoi mielomoi.

Data obtained from karyotyping and estimation of nucleolar organizer (NO) activity in bone marrow cells from 9 patients with multiple myeloma (MM) and from 8 donors are presented. Chromosomes of the 14th and 1st pairs in patients with MM are confirmed to be more frequently involved in rearrangements. It is proved that activity of NO in myeloma cells is rather high as compared to that of erythroid and granulocyte cells, that is associated with their participation in paraprotein synthesis.

[Metabolism of nucleotides and RNA in leukocytes in chronic myeloleukosis]. / Obmen nukleotidov i RNK v leikotsitakh pri khronicheskom mieloleikoze.

Biosynthesis of purine and pyrimidine nucleotides was distinctly increased in leukocytes of patients with chronic myeloid leukosis, involving mainly the reutilization of preformed nitrogenous bases and nucleosides. An increase in the rate of 14C-orotate and 3H-uridine incorporation into the pyrimidine pool of myeloid leukosis cells correlated with stimulation of uridine kinase and orotidine monophosphate pyrophosphorylase, catalyzing biosynthesis of pyrimidine nucleotides in the reutilization pathway and de novo, respectively. The system of adenosine deaminase, providing the high rate of adenosine incorporation into the nucleotide pool, was apparently responsible mainly for the rate of reutilization synthesis of purine nucleotides in normal and leukemic leukocytes. Synthesis of RNA in leukocytes of patients with chronic myeloleukemia was increased mainly due to consumption of nucleotides formed via the reutilization pathway.