Search results for "barrier"
showing 10 items of 678 documents
Impact of polymer-modified gold nanoparticles on brain endothelial cells: exclusion of endoplasmic reticulum stress as a potential risk factor
2016
A library of polymer-coated gold nanoparticles (AuNPs) differing in size and surface modifications was examined for uptake and induction of cellular stress responses in the endoplasmic reticulum (ER stress) in human brain endothelial cells (hCMEC/D3). ER stress is known to affect the physiology of endothelial cells (ECs) and may lead to inflammation or apoptosis. Thus, even if applied at non-cytotoxic concentrations ER stress caused by nanoparticles should be prevented to reduce the risk of vascular diseases and negative effects on the integrity of barriers (e.g. blood-brain barrier). We exposed hCMEC/D3 to twelve different AuNPs (three sizes: 18, 35, and 65 nm, each with four surface-modif…
Neuronal Activity Drives Localized Blood-Brain-Barrier Transport of Serum Insulin-like Growth Factor-I into the CNS
2010
Upon entry into the central nervous system (CNS), serum insulin-like growth factor-1 (IGF-I) modulates neuronal growth, survival, and excitability. Yet mechanisms that trigger IGF-I entry across the blood-brain barrier remain unclear. We show that neuronal activity elicited by electrical, sensory, or behavioral stimulation increases IGF-I input in activated regions. Entrance of serum IGF-I is triggered by diffusible messengers (i.e., ATP, arachidonic acid derivatives) released during neurovascular coupling. These messengers stimulate matrix metalloproteinase-9, leading to cleavage of the IGF binding protein-3 (IGFBP-3). Cleavage of IGFBP-3 allows the passage of serum IGF-I into the CNS thro…
Oppimisen teknologiat osana oppimisen esteitä kohtaavien peruskoululaisten elämää
2017
Tieto- ja viestintäteknologia on merkittävä osa jokapäiväistä elämäämme. Nämä teknologiat ovat löytäneet tiensä kouluihin myös Suomessa, ja erilaisia oppimisen teknologioita onkin otettu ahkerasti käyttöön ympäri maata. Teknologian integroiminen osaksi opetusta ei kuitenkaan aina suju täysin ongelmitta. Laitteiden käytössä saattaa ilmetä ongelmia, ja vaikka infrastruktuuri teknologian käytölle olisikin olemassa, ovat verkkoyhteydet paikoitellen epävakaita. Näiden ongelmien kanssa painivat sekä opettajat että oppilaat. Tämän tutkielman tarkoituksena on tutkia oppimisen teknologioiden vaikutuksia erityisesti oppimisen esteitä kohtaavien oppilaiden oppimiseen. Oppimisen esteitä, kuten erilaisi…
Protease‐activated receptor signaling in intestinal permeability regulation
2019
Protease-activated receptors (PARs) are a unique class of G-protein-coupled transmembrane receptors, which revolutionized the perception of proteases from degradative enzymes to context-specific signaling factors. Although PARs are traditionally known to affect several vascular responses, recent investigations have started to pinpoint the functional role of PAR signaling in the gastrointestinal (GI) tract. This organ is exposed to the highest number of proteases, either from the gut lumen or from the mucosa. Luminal proteases include the host's digestive enzymes and the proteases released by the commensal microbiota, while mucosal proteases entail extravascular clotting factors and the enzy…
Validation of Doloplus-2 among nonverbal nursing home patients : an evaluation of Doloplus-2 in a clinical setting
2010
Published version of an article from the journal: BMC Geriatrics. Also available from the publisher: http://dx.doi.org/10.1186/1471-2318-10-9 BACKGROUND:Pain measurement in nonverbal older adults is best based on behavioural observation, e.g. using an observational measurement tool such as Doloplus-2. The purposes of this study were to examine the use of Doloplus-2 in a nonverbal nursing home population, and to evaluate its reliability and validity by comparing registered nurses' estimation of pain with Doloplus-2 scores.METHOD:In this cross-sectional study, Doloplus-2 was used to observe the pain behaviour of patients aged above 65 years who were unable to self-report their pain. Nurses al…
Nanoscale inhomogeneity of the Schottky barrier and resistivity inMoS2multilayers
2015
Conductive atomic force microscopy (CAFM) is employed to investigate the current injection from a nanometric contact (a Pt coated tip) to the surface of ${\text{MoS}}_{2}$ thin films. The analysis of local current-voltage characteristics on a large array of tip positions provides high spatial resolution information on the lateral homogeneity of the $\mathrm{tip}/{\text{MoS}}_{2}$ Schottky barrier ${\mathrm{\ensuremath{\Phi}}}_{B}$ and ideality factor $n$, and on the local resistivity ${\ensuremath{\rho}}_{\text{loc}}$ of the ${\text{MoS}}_{2}$ region under the tip. Here, ${\mathrm{\ensuremath{\Phi}}}_{B}=300\ifmmode\pm\else\textpm\fi{}24\phantom{\rule{0.28em}{0ex}}\text{meV}, n=1.60\ifmmode…
Oxidative stress in Alzheimer’s Disease: Implications for Prevention and Therapy
2006
Oxidative stress is a marker of neurodegeneration and has been recently shown to be also involved in the early stages of the pathogenesis of various neurodegenerative disorders. In general, all biomolecules of the cell can be oxidized and thereby damaged. Consequently, the concept of neuroprotection by antioxidants has been developed. In many cases the direct scavanging of free radicals have been used as a strategy to prevent oxidative stress damage and a variety of physiological and synthetic antioxidant molecules have been identified and synthesized including the female sex homone estrogen. In Alzheimer’s Disease amyloid-β protein on its way to brain deposition can also induce oxidative c…
Measurement of Evaporation Residue and Fission Cross Sections of the Reaction 30Si + 238U at Subbarrier Energies
2007
Effects of the prolate deformation of 238 U on fusion were studied in the reaction 30 Si + 238 U at bombarding energies close to the Coulomb barrier. The fission (capture) cross sections were measured at the JAEA tandem accelerator to see the enhancement of the cross sections in the subbarrier energy due to the lower Coulomb barrier in the collisions of projectile at the polar sides of 238 U. In order to obtain the direct evidence for complete fusion, evaporation residue cross sections were measured at UNILAC of GSI. At the subbarrier energy of Ec.m. = 133.0 MeV, where only polar collisions to 238 U occur, we measured three spontaneously fissioning nuclei which we assigned to the isotope 26…
Applicability of the dielectric barrier discharge for helium ash measurements in the divertor region
2016
Abstract Controlled fusion based on the magnetic confinement of the plasma is one of the main aims of the Euro-fusion programme. In the fusion device, the hydrogen isotopes, in nuclear reactions, will produce helium nuclei. The products, as the ash, will be removed from the plasma in the region of the so-called divertor. Controlling the helium to hydrogen ratio in this ‘exhaust gas’ will provide information about the efficiency of the fusion process as well as of the efficiency of the helium removal system. One of the methods to perform this task is to study the properties of the discharge conducted in such exhaust gas. In this paper, the applicability of the dielectric barrier discharge (D…
Clients’ Experiences With Internet-Based Psychological Treatments for Mental Disorders: Protocol for a Metasynthesis of Qualitative Studies
2018
Background: Given the rise of internet-based treatments as an effective therapeutic tool for psychological disorders, it is necessary to carry out research that examines clients’ experiences with this type of intervention. The qualitative methodology has been found to be useful for analyzing clients’ perceptions in terms of facilitators and barriers, acceptability, and negative effects of internet-based treatments. However, a lack of integration of these primary studies has prevented their findings from being applied to new research and in clinical practice. Objective: The objective of this paper is to describe the protocol for a metasynthesis of qualitative studies exploring the experience…