Fusion of secretory vesicles isolated from rat liver

Secretory vesicles isolated from rat liver were found to fuse after exposure to Ca2+. Vescle fusion is characterized by the occurrence of twinned vesicles with a continuous cleavage plane between two vesicles in freeze-fracture electron microscopy. The number of fused vesicles increases with increasing Ca2+-concentrations and is half maximal around 10–6 m. Other divalent cations (Ba2+, Sr2+, and Mg2+) were ineffective. Mg2+ inhibits Ca2+-induced fusion. Therefore, the fusion of secretory vesiclesin vitro is Ca2+ specific and exhibits properties similar to the exocytotic process of various secretory cells. Various substances affecting secretionin vivo (microtubular inhibitors, local anethetics, ionophores) were tested for their effect on membrane fusion in our system. The fusion of isolated secretory vesicles from liver was found to differ from that of pure phospholipid membranes in its temperature dependence, in its much lower requirement for Ca2+, and in its Ca2+-specificity. Chemical and enzymatic modifications of the vesicle membrane indicate that glycoproteins may account for these differences

Analysis of mode distribution for PMMA Whispering gallery mode resonators

Polimetilmetakrilāta (PMMA) čukstošo galeriju modu (ČGM) mikro sfēru rezonatori ir komerciāli pieejami ar tipiskajiem labuma (Q) faktoriem 10^3-10^4. Izmantojot attēlu apstrādes tehniku ar augstu izšķirtspēju (1.9µm/px), ir iespējams monitorēt absorbcijas spektru. Šajā darbā tika izstrādāta jauna veida attēlu apstrādes metode priekš ČGM mikro rezonatoriem, lai analizētu intensitātes sadalījumu atsevišķos (40-70µm) PMMA ČGM mikro rezonatoru reģionos mainot ārējos fizikālos apstākļus. Intensitātes izmaiņas var tikt izmantotas lai raksturotu augstāku kārtu modu mijiedarbību un integrētu sensoru sistēmā.Poly methyl methacrylate acrylic (PMMA) whispering gallery mode (WGM) micro sphere resonators are commercially available with typical optical quality factor of 10^3-10^4. Using image processing techniques, with (1.9µm/px) high resolution, the absorption spectrum could be monitored. In the present work a new type of image processing for WGM micro-resonators was developed, to analyze intensity distribution in separate regions for PMMA WGM micro-resonators (40-70 µm) by changing the external physical properties such as temperature and wavelength. The intensity changes can be used as a representation of higher order spacial mode groups and integrated into optical sensors

The Qualitative and Quantitative Models for Performance Measurement Systems: The Agile Service Development

new service development, performance measurement, agile, fuzzy sets,