Visualization of upconverting nanoparticles in strongly scattering media.

Optical visualization systems are needed in medical applications for determining the localization of deep-seated luminescent markers in biotissues. The spatial resolution of such systems is limited by the scattering of the tissues. We present a novel epi-luminescent technique, which allows a 1.8-fold increase in the lateral spatial resolution in determining the localization of markers lying deep in a scattering medium compared to the traditional visualization techniques. This goal is attained by using NaYF4:Yb(3+)Tm(3+)@NaYF4 core/shell nanoparticles and special optical fiber probe with combined channels for the excitation and detection of anti-Stokes luminescence signals.

Stimulated Raman amplification and high-order Raman sideband generation in a polymer waveguide on a printed circuit.

The ultrafast Raman response of C-H vibrations in polymer waveguides on a printed circuit is shown to enable a high-gain amplification and high-order stimulated Raman transformation of ultrashort laser pulses. The pump and Stokes fields coupled by the C-H vibration mode with a vibration cycle of 11 fs give rise to multiple Raman sidebands, suggesting the way toward ultrafast optical data processing and few-cycle optical waveform synthesis on a printed-circuit polymer waveguide platform.

[Red king crab (Paralithodes camtschaticus) in the Barents Sea: a comparative study of introduced and native populations].

Red king crab (Paralithodes camtschaticus) was introduced into the Barents Sea in the 1960-1970s. Its present habitation area spans on the coastal zone from Hammerfest (Northern Norway) to the Barents Sea Funnel in the north-east of the Kola Peninsula. We studied the polymorphism of a mitochondrial gene encoding cytochrome oxidase (COI) and five nuclear microsatellite loci in four samples from the Barents Sea and two donor populations from the Western Kamchatka and Primorye. No decrease in the genetic diversity of the introduced populations was detected. Microsatellite assay demonstrated that the sample from Varrangerfjord was distinct from the rest five populations. However, no significant differences between the rest samples were found. Possible reasons underlying this phenomenon are discussed.

[The histogenesis of interrenal primordium of the adrenal gland in pig (Sus domestica)].

Using light, electron microscopy and cytochemistry, the early (embryonic week 4-8) stages of adrenal gland (AG) development were studied in domestic pig. The interrelations between the cells of the fetal cortex (FC) and chromaffin cells (CC) were traced. At week 5, AG primordium is represented by FC, which consists of the epithelioid cells, with the ingrowing neural cords containing CC islets. Starting at the early embryonic period and up to fetal period, CC and interrenal cells of FC are closely interrelated with each other and sinusoidal capillaries. Both cellular types are at different stages of differentiation, including the functionally active elements. At weeks 7-8, FC cells undergo involution, while those ones, left at periphery, form definitive cortex. CC are located in the central part of the organ and form suprarenal tissue. Authors hypothesize, that CC, migrating into AG primordium, initially induce the development of interrenal primordium, and later cause the involution of FC. This, possibly, may be explained by the fact that further antenatal and postnatal development of the organism requires more corticosteroids than the amount produced by FC.

Temperature dependences of relaxation time, adiabatic and isothermal elastic moduli in ZnSe:Ni and ZnSe:Cr crystals obtained in an ultrasonic experiment.

Theory of ultrasonic absorption and dispersion, based on the Zener equation, was used for constructing the equations, those made it possible to restore the temperature dependences of relaxation time, adiabatic and isothermal elastic moduli on the basis of experimental data on the temperature dependences of ultrasound absorption and phase velocity. This method was used for processing the experimental results obtained in single crystals of ZnSe:Ni and ZnSe:Cr.

[Development of adrenal chromaffin tissue]. / Razvitie khromaffinnoi tkani nadpochechnika.

The purpose of the present investigation was to study the morphological peculiarities of chromaffinoblasts and to determine their interrelations with the surrounding cellular elements of the fetal cortex at the early stages (embryonic weeks 4-7) of their migration into the developing adrenal gland of a pig. At week 5 neuro-cellular cords, consisting of so-called "naked" axons, neuroblasts, lemmoblasts, undifferentiated cells, chromaffinoblast clusters and chromaffinocytes, grow into the fetal cortex from side of abdominal aorta. In fetal cortex parenchyma chromaffin elements form cords, lobes, "medullary globes", which are enveloped by a basal membrane, which is a derivative of satellitocytes. Chromaffinocytes are stained with Wood's stain, potassium bichromate and, judging by the presence of secretory granules in their cytoplasm, are capable to synthesize summary catecholamines and to release them into the blood at the early stages of development. "Medullary globes" are the centers of proliferation and differentiation of the chromaffin cells in the adrenal medulla. The problem of chromaffin tissue stem cells is discussed.

Postural reactions of circulation and its regulation during simulated weightlessness.

The extention and intensification of space exploration the influence of weightlessness on human organism and the formation of a new level of adaptation. The studies of blood circulation is very important because of frequent occurrence of cardiovascular disorders in the middle age subjects. In connection with extension and intensification of space exploration the influence of weightlessness on human organism and the formation of a new level of adaptation mechanisms acquires a special significance. The data obtained in recently undertaken model experiments and also during space flights indicate that weightlessness in many ways affects various physiological systems of organism, and first of all cardiovascular system with the development of reflex, humeral and metabolic reactions. It also indicates, that the changes in functioning of cardiovascular system brings about the disruption of its regular responses, which is foremost expressed in decreased antigravitational response, which manifests itself in lowered orthostatic stability. It is worth mentioning, that the changes during previous investigations of haemodynamics were mainly carried out with the subjects under forty, therefore age related specific features of blood circulation system response are described in a few articles. The studies of the kind are especially important because of frequent occurrence of cardiovascular disorders such as heart and brain vessels atherosclerosis, hypertension in the middle age, which can to a great extent complicate and affect the "acute" period of adaptation to weightlessness and readaptation process.

[Characteristics of the functional state of the nervous system of middle-aged persons during anti-orthostatic hypokinesia]. / Osobennosti funktsional'nogo sostoianiia nervnoi sistemy lits starshego vozrasta v usloviialkh antiortostaticheskoi gipokinezii.

The functional state of the nervous system and its autonomic compartment was investigated in 15 men, aged 40-52 years, during their 30-day exposure to head-down tilt (-8 degrees). Group 1 consisted of 9 subjects with early manifestations of cerebral atherosclerosis and Group 2 included 6 subjects with cerebral atherosclerosis and arterial hypertension. The control group incorporated 9 healthy volunteers, aged 25-39 years. During adaptation to head-down tilt, middle-aged and young subjects showed consistent changes in the nervous system. In response to perturbation effects, autonomic reactions were inert and autonomic support was excessive. However delayed onset of responses, duration and slow recovery of the parameters examined indicated that mechanisms of autonomic regulation were inadequate. These changes were most distinct in middle-aged subjects, particularly in Group 2 subjects: recovery of the functional state of the nervous system was completed by day 20 in middle-aged subjects and by day 9 in young subjects. The observations have demonstrated that the nervous system of most middle-aged subjects (taking into consideration age-related and atherosclerotic changes) has a sufficiently high level of functional capabilities during medium-duration head-down tilt studies.

[Reaction of blood circulation to antiorthostatic hypokinesia in men aged 45-52]. / Reaktsii krovoobrashcheniia na antiortostaticheskuiu gipokinesiiu u muzhin 45-52 let.

Regional and central circulation reactions to 30-day antiorthostatic hypokinesia were investigated in 15 men, aged 45 to 52 years, with early signs of cerebrovascular and aortic atherosclerosis, neurocirculatory dystonia of the hypertensive type, and hypertensive disease of stage I. Regional and central hemodynamics of the subjects of the three groups during and immediately after exposure developed in a different manner.