THE DISTRIBUTION OF THE ENDOPLASMIC RETICULUM IN LIVING PANCREATIC ACINAR CELLS.

Studies on pancreatic acinar cells provided the original evidence for the Ca(2+) releasing action of inositol 1,4,5-trisphosphate (IP(3)). Ironically, this system has presented problems for the general theory that IP(3) acts primarily on the endoplasmic reticulum (ER), because the IP(3)-elicited Ca(2+) release occurs in the apical pole, which is dominated by zymogen granules (ZGs) and apparently contains very little ER. Using confocal and two-photon microscopy and a number of different ER-specific fluorescent probes, we have now investigated in detail the distribution of the ER in living pancreatic acinar cells. It turns out that although the bulk of the ER, as expected, is clearly located in the baso-lateral part of the cell, there is significant invasion of ER into the granular pole and each ZG is in fact surrounded by strands of ER. This structural evidence from living cells, in conjunction with recent functional studies demonstrating the high Ca(2+) mobility in the ER lumen, provides the framework for a coherent and internally consistent theory for cytosolic Ca(2+) signal generation in the apical secretory pole, in which the primary Ca(2+) release occurs from ER extensions in the granular pole supplied with Ca(2+) from the main store at the base of the cell by the tunnel function of the ER

CLINICAL SIGNS AND PATHOMORPHOLOGICAL PICTURE OF HYPOXIC INTRAVENTRICULAR HEMORRHAGE IN NEWBORNS

(Voprosy sovremennoi pediatrii — Current Pediatrics. 2009;8(2):124-125)<br /

SrAl2Si2O8 ceramic matrices for 90Sr immobilization obtained via spark plasma sintering-reactive synthesis

In the present study, an original spark plasma sintering-reactive synthesis (SPS-RS) method for mineral-like ceramic materials based on SrAl2Si2O8 feldspar-like skeleton structure was used for the first time, promising solid-state matrices for reliable immobilization of high-energy 90Sr. The method is based on the “in-situ” reaction of a mixture of SrO, Al2O3 and SiO2 oxides when heated by a unipolar pulsed current under compacting pressure. The phase and elemental composition structure were studied. The dynamics of the consolidation of the reaction mixture of oxides was studied in the range of 900–1200 °C. The study found the temperature of the high-speed (minutes) SPS-RS formation of single-phase SrAl2Si2O8 composition ceramic in the absence of intermediate reaction products with a relative density of up to 99.2% and compressive strength up to 145 MPa and a strontium leaching rate of 10−4g/cm2·day

EFFECT OF COMPOSITION AND STRUCTURE ON TRANSPORT PROPERTIES OF CHALCOGENIDE GLASSES

The effect of preparation regime and molecular composition on dispersive transport properties of amorphous chalcogenide films of As-Se, As2S3-Sb2S3 and As2S3 : Sn has been investigated by time-of-flight method. Hole transit time (corresponding to drift mobility) in the system As-Se was found to be dependent on preparation regime, this dependence being mostly exhibited in non-stoichiometric films. In As2S3-Sb2S3 system the transit time and its activation energy are gradually decreased with increasing of Sb2S3 content. The transit time of As2S3 films doped with Sn up to 0.3 at.% is decreased by as much as 3 to 4 orders of magnitude at room temperature and in the interval from 295 to 360 K increases with temperature. The results are discussed in frames of a model for anomalous charge carrier drift controlled by capture in a system of energy distributed traps