Anisotropic tapered polarization-maintaining large mode area optical fibers.

We demonstrate a novel type of tapered large mode area polarization-maintaining fiber. These birefringent fibers have an elliptical inner cladding and a core diameter that increases adiabatically from 8 µm to 70 µm. The polarization maintaining ability of the fiber samples was investigated by measuring the spatial distribution of polarization beat length by using optical frequency-domain reflectometry. The measurements show a clear correlation between the birefringence and the fiber core size, resulting in a modest 10-15% variation in polarization beat length along the fiber. There is no significant coupling of polarization modes or transverse modes in the tested fibers and, therefore, the linear polarization state of propagating light is preserved.

A high frequency resonance gravity gradiometer.

A new setup OGRAN--the large scale opto-acoustical gravitational detector is described. As distinguished from known gravitational bar detectors it uses the optical interferometrical readout for registering weak variations of gravity gradient at the kilohetz frequency region. At room temperature, its sensitivity is limited only by the bar Brownian noise at the bandwidth close to 100 Hz. It is destined for a search for rare events--gravitational pulses coincident with signals of neutrino scintillator (BUST) in the deep underground of Baksan Neutrino Observatory of INR RAS.

[Ultrastructural analysis of the role of microtubules in the transport and exocytosis of protein secretion in secretory cells of mouse mammary glands]. / Ul'trastrukturnyi analiz roli mikrotrubochek v transporte i ékzotsitoze belkovogo sekreta v sekretornykh kletkakh molochnoi zhelezy myshi.

Morphometrical analysis of microtubules (MT) and coated vesicles (CV) was done on electron micrographs of the murine mammary gland sections at the final stages of functional maturation of secretory cells (SC), as well as at different stages of the cell secretory cycle (CSC). The results obtained allow to make the following conclusions: 1) dynamics of changes in the MT count in different subplasmalemmal cell compartments is similar, being directly associated with heterochronical character of CSC processes; 2) the maximum MT count in SC was seen during formation of the secretion product, this increase occurring at the expense of short MT, which are disassembled before and during exocytosis of secretory vesicle (SV) contents; 3) changes in the number of MT and CV are of similar character, which was revealed by morphometrical analysis of SC in the course of maturation. The number of MT and CV in SC increased rapidly and significantly on the 1st and 2nd days after parturition, compared to that observed 1-2 days before parturition. However, the number of MT and CV decreased by the 10th day of lactation, when the mammary secretory activity reached its maximum. Both correlation and regression statistical analyses made during the CSC development point to a linear relation between MT (x) and CV (y) numbers. Regression of y on x is: y = -0.89 + 12.43x. A hypothesis about the possibility of MT participation in CV and SV transport and in the formation of a barrier on the path leading to exocytosis of SV contents is suggested.

[The neuroendocrine aspects of the participation of the epiphysis in the regulation of lactation]. / Neiroéndokrinnye aspekty uchastiia épifiza v reguliatsii laktatsii.

Pinealectomy was shown to suppress the milk ejection reflex and increase the luteinizing hormone secretion in lactating rats. Suckling caused the same type changes of prolactin though at a lower level, in these rats. The data obtained suggest that the pineal gland together with the oxytocinergic system are involved in complex mechanisms of neurohumoral regulation of the lactogenic and gonadotropic hormones secretion during lactation.

[Bioelectrical reactions on the surface of the mamma in the goat]. / Bioélektricheskie reaktsii na poverkhnosti molochnoi zhelezy kozy.

Spontaneous and evoked biopotentials were recorded on the mammary gland surface in goats. The biopotentials appear in the course of secretion during milk ejection as well as under electrical, mechanical and hormonal actions. They might be considered as adequate indices of secretion and ejection processes in the mammary gland.

[The reaction of mammary tissue basophils to oxytocin]. / Reaktsiia tkanevykh bazofilov molochnoi zhelezy na oksitotsin.

By means of staining with base brown and toluidin blue mast cells were revealed in paraffine sections of the lactating albino mouse mammalian gland. The character of mast cells distribution in the gland tissue was studied, the distribution density was assessed and the complex morphometric analysis of the mast cells population in normal and 20 min, after administration of oxytocin, stimulating the milk elimination from the alveoli and the following secrete forming in the gland cells was performed. Under initial conditions of the experiment at the inhibition of the secretory process the mast cells degranulation index made 30% while after the administration of oxytocin in increased up to 52%. Correlation between the mast cells groups with the diverse extent of granule content in cytoplasm was changing. Thus, oxytocine effect appears to be the factor, influencing the mast cells population functional activity.

[Study of axodendritic synapses of the hippocampal CA3 field in experimental uremia and administration of exogenous parathyroid hormone]. / Issledovanie aksoshipikovykh sinapsov polia CA3 gippokampa pri éksperimental'noi uremii i vvedenii ékzogennogo paratireoidnogo gormona.

The effect of parathyroid hormone intraperitoneal injection at different stages of experimental uremia induced by subtotal nephrectomy on ultrastructural morphofunctional characteristics of hippocampus Ca3 field axospinal synapses was studied. A conclusion is made that the decrease of synaptic activity in the hippocampus field due to redistribution of calcium ions between spine cytoplasm and spine apparatus may take place after PTH injection and during uremia development.

[The structural organization of the cytoskeleton of the mammary secretory cells]. / Organizatsiia struktur tsitoskeleta sekretornykh kletok molochnoi zhelezy.

A study was made of the arrangement and specialties of distribution in the mammary secretory cells of albino mice of the following cytoskeleton ultrastructures: microtubules (MT), organization centres (MTOC), microfilaments (MF) and intermediate filaments (IF). During the last period of pregnancy and at different stages of lactation, for the alveolar epithelium the presence of a single material centrioles (CN) was shown in the region of the apical surface near dense intercellular contact. During pregnancy and especially at the beginning of lactation (1-2 days) the relatively large density of the MT was observed in both the cytoplasm of the secretory cells and the region near the CN. On the most hard days of lactation (10 day) the lowering of the number of all the observed structures was held in the majority of the cells. The MT was not observed near the CN. It appeared that the elimination of the MTOC activity during the most hard time of lactation is related to the decrease in the numbers of MT, MF and IF. The pattern of cytoskeleton reorganization, associated with the development of the functional activity of the observed cells, enables us to suggest a cooperative contribution of its base components in the formation of the secretory surface and in the carrying out of exocytosis.

[The influence of oxytocin on the membrane potentials of mammary gland secretory cells]. / O vliianii oksitotsina na membrannyi potentsial sekretornykh kletok molochnoi zhelezy

The effect of oxytocine and its combinations with the acetylcholine, adrenaline, atropin, and prozerin on the level of membrane potential of mammary secretory cells was studied. Short oxytocine application (5-10(-4) ME/ml) evoked hyperpolarization of the contraluminal membrane (12+/-1 mV for 54+/-5 sec). Their response was increased by joint application of acetylcholine or proserine and decreased by preliminary application of atropin. Adrenaline increased or decreased the amplitude of the membrane potential's changes and considerably reduced the duration of the oxytocine reaction. Existence of oxytocine receptors was supposed on the membrane of secretory cells, as well as the possibility of acetylcholine and adrenaline effects on the structure of oxytocine receptors or the interaction of adreno--and cholinergic receptors with the oxytocine those.