Immunofluorescent Evidence for Nuclear Localization of Aromatase in Astrocytes in the Rat Central Nervous System

Estrogens regulate a variety of neuroendocrine, reproductive and also non-reproductive brain functions. Estradiol biosynthesis in the central nervous system (CNS) is catalyzed by the enzyme aromatase, which is expressed in several brain regions by neurons, astrocytes and microglia. In this study, we performed a complex fluorescent immunocytochemical analysis which revealed that aromatase is colocalized with the nuclear stain in glial fibrillary acidic protein (GFAP) positive astrocytes in cell cultures. Confocal immunofluorescent Z-stack scanning analysis confirmed the colocalization of aromatase with the nuclear DAPI signal. Nuclear aromatase was also detectable in the S100β positive astrocyte subpopulation. When the nuclear aromatase signal was present, estrogen receptor alpha was also abundant in the nucleus. Immunostaining of frozen brain tissue sections showed that the nuclear colocalization of the enzyme in GFAP-positive astrocytes is also detectable in the adult rat brain. CD11b/c labelled microglial cells express aromatase, but the immunopositive signal was distributed only in the cytoplasm both in the ramified and amoeboid microglial forms. Immunostaining of rat ovarian tissue sections and human granulosa cells revealed that aromatase was present only in the cytoplasm. This novel observation suggests a new unique mechanism in astrocytes that may regulate certain CNS functions via estradiol production.     

Conformance testing of VMEbus and Multibus II products

A system for testing VMEbus and Multibus II products is described. The system is mainly automated to reduce costs and ensure impartiality. A test campaign is explained in the sense of a walk through the test system, in the way of a customer-such as a manufacturer, reseller, or original equipment manufacturer-would see it. The focus is on testing bus interfaces because it is more complex than testing backplanes     

Hole transport in selenium-based amorphous xerographic photoreceptors

Xerographic time of flight (XTOF) and conventional time of flight (TOF) experiments were used to determine the response of various selenium-based amorphous monolayer photoreceptors to short light pulses. From the observed flight time, the hole drift mobility, _h, of charge carriers was deduced.For pure and lightly doped a-selenium, transient photocurrent signals at low field in both experiments exhibit a decay during the time prior to transit time. This has been attributed to the loss of charge carriers from the propagation photoinjected charge packet and the time constant of the decay, _h, has been taken as the hole lifetime. Detailed analysis was carried out on transient signals obtained from both experiments to examine this interpretation. For a given composition, sample thickness, light intensity, substrate material and top contacts (in TOF only) were varied to ensure that the observed decay time constant _h is a meaningful bulk parameter. Hole transport measurements support the assignment of _h as hole lifetime. _h and _h were measured as a function of composition and applied field. Experimental data suggest that the hole transport mechanism is shallow trap controlled. Light doping of selenium with arsenic creates shallow traps and hence causes hole transport to deteriorate. Addition of chlorine promotes hole transport by increasing the lifetime but the hole drift mobility is reduced. Addition of tellurium in the range 0–7 wt% progressively decreases hole drift mobility, due to an increase in the density of the shallow traps. When chlorine is added to Se-Te alloys, it improves the hole transport by increasing _h but the hole mobility falls. Hole drift mobility in all systems except for hole response in pure selenium is field dependent of the form _h ^– E ⁿ where E is the applied field and n is a constant less than unity.     

Hydrolysis of fatty acid esters in subcritical water

Hydrolysis of esters of higher fatty acids by subcritical water, performed in a flow‐through tubular reactor, was investigated at temperatures from 280 up to 340 °C and pressures exceeding 12 MPa, using an ester/water ratio of 1 : 2 or 1 : 4 (vol/vol). The kinetics of the hydrolysis of both the triacylglycerols and the methyl esters obeyed the rate equation valid for first‐order reactions. Conversion of the esters to free fatty acids exceeding 95% was reached at the temperature of 340 °C during 12 min. IR spectroscopy revealed structural changes in the chains of the unsaturated fatty acids and their partial polymerization during the hydrolysis.     

Shelf life of packaged sliced dry fermented sausage under different temperature

The aim of this study was to investigate the shelf-life of commercial sliced dry fermented sausage during storage at different temperatures. Different laminate composition was used for vacuum and nitrogen (100% N₂) packaging. The microbiological, physico-chemical and sensory parameters were analysed during 120 days storage at 4, 22 and 37 °C. Packaging materials were analysed for their barrier characteristic (oxygen permeability).     

The Rheology of Stabilised Lanthanum Strontium Cobaltite Ferrite Nanopowders in Organic Medium Applicable as Screen Printed SOFC Cathode Layers

The production and optimisation of screen printing (SP) pastes containing La_0.58Sr_0.42Co_0.21Fe_0.79O_{3 – δ} and La_0.61Sr_0.41Co_0.19Fe_0.79O_{3 – δ} (LSCF) were investigated. The application of these nanopowders is supposed to improve the cathode's microstructure and increase its mechanical strength. Thirty seven pastes containing LSCF were carried out with variation in binders, dispersants and different particle size distribution. The rheological behaviour of these pastes was investigated. It was found that commercially available dispersant Solsperse 3000 resulted in the best suspension stability, achieving almost 55 times lower viscosity value for pastes containing 20 vol.‐%, than pastes without any dispersants. The shear thinning behaviour was found to be favourable for the LSCF cathode deposition. A cathode made from the mixture of nano and submicron powder exhibits a polarisation resistance as low as 0.76 Ω cm² at 592 °C.     

Functionality of chitosan-halloysite nanocomposite films for sustained delivery of antibiotics: The effect of chitosan molar mass

This study was designed to investigate functionality of tetracycline-loaded chitosan-halloysite nanocomposite films, with focus on evaluating the influence of chitosan molar mass on films applicability for sustained local antibiotic delivery. The films were prepared by casting and solvent evaporation using low, medium, and high molar mass chitosan. SEM analysis revealed compact, nonporous and rough surface of the nanocomposite films due to the presence of halloysite agglomerates and tetracycline crystals. Increasing chitosan molar mass led to higher values of elongation at break (from 21.65 ± 2.65 to 34.48 ± 2.34%), tensile strength (from 134.8 ± 13.21 to 246.36 ± 14.69 MPa), and elastic modulus (from 633.79 ± 128.37 to 716.55 ± 60.76 MPa) of the nanocomposite films. FT-IR, XRPD, and thermal analyses confirmed molar mass dependent chitosan-halloysite interactions and improved thermal stability of the nanocomposite films in comparison with chitosan films. The nanocomposite films released tetracycline in a sustained manner, with the slowest release achieved from the films consisting of low molar mass chitosan. Chitosan molar mass was confirmed to be a functionality-related characteristic of chitosan-halloysite nanocomposite films as potential sustained-release carriers for topical delivery of antibiotics. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48406.     

Laser-induced optical breakdown on hard and soft tissues and itsdependence on the pulse duration: experiment and model

Threshold values of laser-induced optical breakdown (LIOB) on the surface of human corneal tissues, human enamel, and bovine brain tissues are presented. The data are obtained by using a regeneratively amplified Nd:YLF laser and a multistage dye laser system, respectively. The measured decrease in threshold fluence at shorter pulse durations is in good agreement with the authors' theoretical model