Search results for "Down"
showing 10 items of 1658 documents
The nicotinic acetylcholine receptor agonist ABT-594 increases FGF-2 expression in various rat brain regions
2000
The present experiments were designed to extend previous work showing that acute intermittent (-)nicotine treatment upregulates the level of fibroblast growth factor-2 (FGF2) mRNA in several rat brain regions, by the use of the nicotinic acetylcholine receptor (nAChR) agonist ABT-594 with preferential selectivity for the alpha4beta2 nAChR subtype. ABT594 treatment led to a well-defined temporal and regional upregulation of FGF-2 mRNA. A double labelling analysis showed that the up-regulation of FGF-2 mRNA involves both neuronal and non-neuronal cells. The effects of ABT-594 on FGF-2 expression were antagonized by the preferential alpha4beta2 antagonist dihydrobetaerythroidine (DHbetaE), but…
Progesterone increases basal 3',5'-cyclic adenosine monophosphate formation and down-regulates the agonist-induced inositol phosphates generation in …
1992
Whether the placenta is a target tissue for estrogens and progesterone, and their putative mechanism of action, is still a controversial question in the literature. The effect of progesterone and estradiol on 3′,5′-cyclic adenosine monophosphate (cAMP) and inositol phosphates generation in human term placenta was investigated. Placental explants were incubated in vitro for up to 48 h in the absence and in the presence of estradiol, progesterone or both steroids (0.1 μmol/l final concentration in all cases), and were stimulated with terbutaline, a β-adrenergic agonist, (0.1 mmol/l) or angiotensin II(1 μmol/l), The cAMP content was measured by a competitive protein binding assay, and the gene…
Arithmetical Analysis of Biomolecular Finite Automaton
2013
In the paper we present a theoretical analysis of extension of the finite automaton built on DNA (introduced by the Shapiro team) to an arbitrary number of states and symbols. In the implementation we use a new idea of several restriction enzymes instead of one. We give arithmetical conditions for the existence of such extensions in terms of ingredients used in the implementation.
The role of NO in contact hypersensitivity
2001
Contact dermatitis or contact hypersensitivity (CHS) is a common T lymphocyte-mediated allergic disease characterized by local inflammatory skin reactions following contact with small reactive compounds called haptens. In common with other allergic processes, the development of contact dermatitis proceeds in two phases: a sensitization phase which occurs on first exposure to allergen, and an elicitation phase which occurs on subsequent exposure when the clinical manifestations of the disease are observed. This process is hapten-specific. While the pathophysiology of the sensitization phase is well characterized, our understanding of the elicitation phase is still incomplete, including the r…
Properties of native ultrathin aluminium oxide tunnel barriers
2003
We have investigated planar metal–insulator–metal tunnel junctions with aluminium oxide as the dielectricum. These oxide barriers were grown on an aluminium electrode in pure oxygen at room temperature till saturation. By applying the Simmons model we derived discrete widths of the tunnelling barrier, separated by Δs ≈ 0.38 nm. This corresponds to the addition of single layers of oxygen atoms. The minimum thickness of s0 ≈ 0.54 nm is then due to a double layer of oxygen. We found a strong and systematic dependence of the barrier height on the barrier thickness. Breakdown fields up to 5 GV m−1 were reached. They decreased strongly with increasing barrier thickness. Electrical breakdown could…
How self-assembly of amphiphilic molecules can generate complexity in the nanoscale
2015
Abstract Given the importance of nanomaterials and nanostructures in modern technology, in the past decades much effort has been directed to set up efficient bottom up protocols for the piloted self-assembly of molecules. However, molecules are generally disinclined to adopt the desired structural organization because they behave according to their own specific intermolecular interactions. Thus, only some selected classes of chemical compounds are capable to lead to useful self-assembled structures. Amphiphiles, simultaneously possessing polar and apolar moieties within their molecular architecture, can give a wide scenario of possible intermolecular interactions: polar–polar, polar–apolar,…
Cellular Prion Protein Participates in Amyloid-β Transcytosis across the Blood—Brain Barrier
2012
The blood—brain barrier (BBB) facilitates amyloid-β (Aβ) exchange between the blood and the brain. Here, we found that the cellular prion protein (PrPc), a putative receptor implicated in mediating Aβ neurotoxicity in Alzheimer's disease (AD), participates in Aβ transcytosis across the BBB. Using an in vitro BBB model, [125I]-Aβ1–40 transcytosis was reduced by genetic knockout of PrPc or after addition of a competing PrPc-specific antibody. Furthermore, we provide evidence that PrPc is expressed in endothelial cells and, that monomeric Aβ1–40 binds to PrPc. These observations provide new mechanistic insights into the role of PrPc in AD.
Detection of fluorine using laser-induced breakdown spectroscopy and Raman spectroscopy
2017
In general, the detection of F and other halogens is challenging through conventional techniques. In this paper, various approaches for the qualitative and quantitative analysis of F using the laser-induced breakdown spectroscopy (LIBS) technique were demonstrated. In LIBS, fluorine detection can be realized by means of atomic lines and molecular bands. For the purposes of our experiment, two sets of pellets with various contents of CaF2, CaCO3 and cellulose were analyzed using a lab-based LIBS system under a He atmosphere. The fluorine atomic line at 685.60 nm was correlated with CaF signals proving their close relationship. Consequently, the limits of detection were determined for both an…
Inhibition of Histone Deacetylase Activity in Human Endometrial Stromal Cells Promotes Extracellular Matrix Remodelling and Limits Embryo Invasion
2011
Invasion of the trophoblast into the maternal decidua is regulated by both the trophoectoderm and the endometrial stroma, and entails the action of tissue remodeling enzymes. Trophoblast invasion requires the action of metalloproteinases (MMPs) to degrade extracellular matrix (ECM) proteins and in turn, decidual cells express tissue inhibitors of MMPs (TIMPs). The balance between these promoting and restraining factors is a key event for the successful outcome of pregnancy. Gene expression is post-transcriptionally regulated by histone deacetylases (HDACs) that unpacks condensed chromatin activating gene expression. In this study we analyze the effect of histone acetylation on the expressio…
Re-giardinieri e Natura selvaggia. Implicazioni politico-simboliche dello sradicamento, taglio e trasporto in città degli alberi nella Mesopotamia de…
2022
In Sumerian mythological literature, as in coeval Akkadian one, between the end of the 3rd and the beginning of the 2nd millennium, the ruler, foremost among them Gilgameš, on several occasions uproots and/or cuts down trees. These trees should be understood as elements of a wider ‘Wilderness’, with which they share a powerful and ambiguous ontological otherness compared to the city and, more generally, to the land of Sumer. The action of the king on the tree, like that of a farmer or gardener, with the consequent realization of ‘artefacts’, allows, through a cultural organization of the power of the tree, the renewal of the relationship, always subject to crisis, between the human communit…