1,453 research outputs found
Orexin A in cortical cultures: expression and effect on synaptogenesis during development
Orexin-A (OXA) is an excitatory hypothalamic neurotransmitter and ligand for Orexin Receptor-1 (OR1), isolated from a small group of hypothalamic neurons. OXA orchestrates different brain functions, and at the cognitive level some of the effects of insufficiency of OXA are well-known, for example in Parkinsonâs disease. It is widely assumed that deteriorated cognitive processes are related to impaired network connectivity. However, little is known about the effects of OXA in network connectivity and synaptogenesis. Therefore, to obtain insight into this problem we designed experiments with two groups of networks of dissociated cortical neurons: one group incubated in a plain medium and another chronically treated with OXA. After one, two, three or four weeks in vitro we applied immunocytochemistry for detection of OXA, OR1 and synaptic marker synaptophysin. Shortly after plating, 91±8% of the neurons cultivated in a plain medium expressed OXA-immunoreactivity, which does normally not occur in vivo indicating that neurons may change their phenotype under non-natural culture conditions to develop synaptically coupled networks. The fraction of orexinergic neurons decreased to 33±21% after 4 weeks in vitro. OXA expression was highest in the first week of network formation, the period of maximum synaptogenesis, and then decreased and stabilized in the weeks thereafter. Our hypothesis that OXA plays a role in the network development as a synaptogenic factor was supported by higher levels, earlier onset, and sustained increase of synaptophysin-expression in experiments with chronic OXA application to the culture medium
STATUS OF APPLYING OF INTERNATIONAL ENERGY MANAGEMENT STANDARDS IN UKRAINE
National standards harmonized with international, which are fundamental for the creation of efficient energy management systems. However, the requirements of Directive 2012/27 / EU fully expedient is to harmonize all the ISO 50000 series of standards, as well as the related series of standards EN 16247 (energy audits), ISO 11011 (evaluation of the energy efficiency of compressed air systems), ISO / ASME 14414 (evaluation energy pump installations), ISO 80000-1 and IEC 60027 series (scientific and mathematical quantities and their units, letter symbols), ISO / IEC / TS 17022 (requirements and recommendations for the content of the report of the Audit management system, conducted by a third party), ISO / IEC / TS 17023 (installation for determining the duration of the certification audits of management systems), ISO / TR 16344 (terms, definitions and symbols to assess the energy performance and energy certification of buildings), ISO 16818 (the terminology of energy efficiency in the design of engineering systems of buildings) , ISO 17747 (determination of the energy saving potential in organizations), ISO / IEC guide 98-3 (guide to the expression of uncertainty in measurement).National standards harmonized with international, which are fundamental for the creation of efficient energy management systems. However, the requirements of Directive 2012/27 / EU fully expedient is to harmonize all the ISO 50000 series of standards, as well as the related series of standards EN 16247 (energy audits), ISO 11011 (evaluation of the energy efficiency of compressed air systems), ISO / ASME 14414 (evaluation energy pump installations), ISO 80000-1 and IEC 60027 series (scientific and mathematical quantities and their units, letter symbols), ISO / IEC / TS 17022 (requirements and recommendations for the content of the report of the Audit management system, conducted by a third party), ISO / IEC / TS 17023 (installation for determining the duration of the certification audits of management systems), ISO / TR 16344 (terms, definitions and symbols to assess the energy performance and energy certification of buildings), ISO 16818 (the terminology of energy efficiency in the design of engineering systems of buildings) , ISO 17747 (determination of the energy saving potential in organizations), ISO / IEC guide 98-3 (guide to the expression of uncertainty in measurement)
Biochemical, histological and histochemical changes in Aristichthys nobilis Rich. liver exposed to thiamethoxam
Background and purpose: The aim of the present study was to investigate the effects of the insecticide thiamethoxam on some biochemical, histological and histochemical parameters of bighead carp liver (Aristichthys nobilis), which is an economically important fish species for aquaculture.
Materials and methods: Different increasing concentrations of 6.6 mg l-1, 10 mg l-1 and 20 mg l-1 of the test chemical under laboratory conditions were tested for their toxicity on fish for 96. The hepatic activity of the enzymes lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) were measured. In addition, the hepatic histological structure was observed for alterations, as well as the lipid content was observed by histochemical staining.
Results: It was determined that the enzymatic activity of the exposed fish was increased compared to the control group (p<0.05). Furthermore, the enzymatic activity was increased proportionally to the increasing thiamethoxam concentrations. The histological lesions, which were observed in the liver parenchyma, were degenerative and necrotic. The degenerative alterations were as follows: granular, balloon and fatty degeneration. The necrotic alterations in the fish liver were associated with presence of karyopyknosis, karyorrehsis and karyolysis, respectively. The histological alterations in the liver blood vessels were hyperemia and lymphocyte proliferation. Along with the established histological changes in the liver parenchyma, we found presence of fatty degeneration in the hepatocytes using Sudan III staining on cryostat sections.
Conclusions: Our study shows that there is a relation between the concentration of the insecticide and biochemical changes, as well the severity of expression of the histological and histochemical alterations in the bighead carp liver. Overall, such experiments could be successfully applied in research and monitoring programs to study the effects of pesticides on fish
Time-dependent changes in ghrelin-immunoreactivity in dissociated neuronal cultures of the newborn rat neocortex
Ghrelin is a hormone, initially described as a gastric peptide stimulating appetite and growth hormone secretion, which also has an important role in the regulation of many other processes, including higher brain functions. Ghrelin has been described in situ in different parts of the brain, but so far there has been no data about its expression in cell cultures. Therefore, we aimed in this study to investigate the levels of ghrelin in dissociated cortical neurons at various times in culture. We applied the ABC immunocytochemical method for the detection of ghrelin in one-day-, one-week-, and two-week-old cultures. Our results clearly show that at the early stages after plating the cultures 86.2% (± 8.93) of the neurons are ghrelin-positive and their number decreases during the culturing period. As ghrelin is present in the majority of cultured newborn neurons, when the neuronal differentiation and network formation take place, it may also influence the early synaptic formation and cell-to-cell interactions, which are both very important for network functions like learning and memory
Kitaev interactions between j=1/2 moments in honeycomb Na2IrO3 are large and ferromagnetic: insights from ab initio quantum chemistry calculations
NaIrO, a honeycomb 5 oxide, has been recently identified as a
potential realization of the Kitaev spin lattice. The basic feature of this
spin model is that for each of the three metal-metal links emerging out of a
metal site, the Kitaev interaction connects only spin components perpendicular
to the plaquette defined by the magnetic ions and two bridging ligands. The
fact that reciprocally orthogonal spin components are coupled along the three
different links leads to strong frustration effects and nontrivial physics.
While the experiments indicate zigzag antiferromagnetic order in NaIrO,
the signs and relative strengths of the Kitaev and Heisenberg interactions are
still under debate. Herein we report results of ab initio many-body electronic
structure calculations and establish that the nearest-neighbor exchange is
strongly anisotropic with a dominant ferromagnetic Kitaev part, whereas the
Heisenberg contribution is significantly weaker and antiferromagnetic. The
calculations further reveal a strong sensitivity to tiny structural details
such as the bond angles. In addition to the large spin-orbit interactions, this
strong dependence on distortions of the IrO plaquettes singles out the
honeycomb 5 oxides as a new playground for the realization of
unconventional magnetic ground states and excitations in extended systems.Comment: 13 pages, 2 tables, 3 figures, accepted in NJ
Enhanced solubility of rapeseed meal protein isolates prepared by sequential isoelectric precipitation
The solubility of plant protein isolates is a key determinant of their potential application. Two protein isolates (PI) from ethanol-treated industrial rapeseed meal, PI10.5â2.5 and PI2.5â8.5, were prepared by sequential isoelectric precipitation of alkali-extracted proteins (pH 12) starting from pH 10.5 to 2.5 or from pH 2.5 to 8.5, respectively. Biochemical analyses revealed that PI2.5â8.5 contained a higher amount of crude protein (72.84%) than PI10.5â2.5 (68.67%). In the same protein isolate, the level of total phenols (0.71%) was almost two-fold higher than that in PI10.5â2.5 (0.42%). No glucosinolates were established in both protein isolates. SDS-PAGE analysis demonstrated that PI10.5â2.5 contained 10 to 15 kDa protein fractions in a relatively higher amount, while PI2.5â8.5 was enriched in 18 to 29 kDa protein fractions. PI10.5â2.5 exhibited high solubility, varying from 41.74% at pH 4.5 to 65.13% at pH 6.5, while PI2.5â8.5 was almost two-fold less soluble under the same conditions. Up to pH 5.5, the addition of NaCl at 0.03 and 0.25 M diminished the solubility of PI2.5â8.5, while the solubility of PI10.5â2.5 was increased. The supplementation of PI10.5â2.5 with 0.25 M NaCl enhanced the protein solubility to 56.11% at pH 4.5 and 94.26% at pH 6.5. The addition of 0.03 M NaCl also increased the solubility of this protein isolate but to a lower extent. Overall, the approach for sequential
precipitation of proteins influenced the biochemical characteristics, protein fractional profile and
solubility of prepared protein isolates.info:eu-repo/semantics/publishedVersio
Corrosion stability of stainless steel, modified electrochemically with Ce 2 O 3 -CeO 2 films, in 3.5% NaCl media
This work is focused on the study of corrosion-protection ability of the thin ceria film, formed electrochemically on OC404 stainless steel (SS) in non-aqueous electrolytes. The influence of changes in the surface concentration of Ce 2 O 3 -CeO 2 on the corrosion behaviour of OC404 stainless steel in 3.5% NaCl was investigated prior to the thermal treatment as well as after it. A shift of corrosion potential in positive direction was found via polarization curve recording, as well as via decrease in the corrosion current, respectively decrease in the corrosion rate (enhancement of the corrosion protection) in the presence of ceria oxide films. The data, acquired by AFM and XPS, are in a good agreement with these results. On the basis of the obtained results we can conclude that the presence of Ce 2 O 3 -CeO 2 film results in passivation and re-passivation of the steel surface and a slowdown in the pitting corrosion in an aggressive media. These conclusions are explained by the strong polarization influence of the Ce 2 O 3 -CeO 2 layers on the conjugated depolarization cathodic reaction of reduction of the dissolved oxygen
Postnatal cerebellar development in a mouse
The cerebellum is a part of the central nervous system, which plays an important role in cognitive functions, discriminative sensibility, and the coordination of voluntary movements. Its development takes place in two stages: prenatal and postnatal. The cerebellar germ originates from the rhombic lip. There are two major groups of cells: glutamatergic and GABAergic neurons, which are generated at different spatial-temporal intervals. In the postnatal period, Purkinje cells and their synaptic contacts undergo the most significant development. Another key point is the formation of anchoring centers and the foliation of the brain.The cerebellum is a part of the central nervous system, which plays an important role in cognitive functions, discriminative sensibility, and the coordination of voluntary movements. Its development takes place in two stages: prenatal and postnatal. The cerebellar germ originates from the rhombic lip. There are two major groups of cells: glutamatergic and GABAergic neurons, which are generated at different spatial-temporal intervals. In the postnatal period, Purkinje cells and their synaptic contacts undergo the most significant development. Another key point is the formation of anchoring centers and the foliation of the brain
- âŠ