3,931 research outputs found
Use of Coulter counter for counting ascospores of Neurospora
Use of Coulter counter for counting ascospore
Suppression of pyr-3 mutants of Neurospora
Suppression of pyr-3 mutants of Neurospor
Suppression of pyr-3 mutants by arg-12 mutants
Suppression of pyr-3 mutants by arg-12 mutant
Observations of perpetual hyphal propagation in Neurospora crassa
Observations of perpetual hyphal propagation in Neurospora crass
Receptor tyrosine kinase inhibitors negatively impact on pro-reparative characteristics of human cardiac progenitor cells
Receptor tyrosine kinase inhibitors improve cancer survival but their cardiotoxicity requires investigation. We investigated these inhibitors' effects on human cardiac progenitor cells in vitro and rat heart in vivo. We applied imatinib, sunitinib or sorafenib to human cardiac progenitor cells, assessing cell viability, proliferation, stemness, differentiation, growth factor production and second messengers. Alongside, sunitinib effects were assessed in vivo. Inhibitors decreased (\u1d631 < 0.05) cell viability, at levels equivalent to 'peak' (24 h; imatinib: 91.5 ± 0.9%; sunitinib: 83.9 ± 1.8%; sorafenib: 75.0 ± 1.6%) and 'trough' (7 days; imatinib: 62.3 ± 6.2%; sunitinib: 86.2 ± 3.5%) clinical plasma levels, compared to control (100% viability). Reduced (\u1d631 < 0.05) cell cycle activity was seen with imatinib (29.3 ± 4.3% cells in S/G2/M-phases; 50.3 ± 5.1% in control). Expression of PECAM-1, Nkx2.5, Wnt2, linked with cell differentiation, were decreased (\u1d631 < 0.05) 2, 2 and 6-fold, respectively. Expression of HGF, p38 and Akt1 in cells was reduced (\u1d631 < 0.05) by sunitinib. Second messenger (p38 and Akt1) blockade affected progenitor cell phenotype, reducing c-kit and growth factor (HGF, EGF) expression. Sunitinib for 9 days (40 mg/kg, i.p.) in adult rats reduced (\u1d631 < 0.05) cardiac ejection fraction (68 ± 2% \u1d637\u1d634. baseline (83 ± 1%) and control (84 ± 4%)) and reduced progenitor cell numbers. Receptor tyrosine kinase inhibitors reduce cardiac progenitor cell survival, proliferation, differentiation and reparative growth factor expression
Designing informative warning signals: Effects of indicator type, modality, and task demand on recognition speed and accuracy
An experiment investigated the assumption that natural indicators which exploit
existing learned associations between a signal and an event make more effective
warnings than previously unlearned symbolic indicators. Signal modality (visual,
auditory) and task demand (low, high) were also manipulated. Warning
effectiveness was indexed by accuracy and reaction time (RT) recorded during
training and dual task test phases. Thirty-six participants were trained to
recognize 4 natural and 4 symbolic indicators, either visual or auditory, paired
with critical incidents from an aviation context. As hypothesized, accuracy was
greater and RT was faster in response to natural indicators during the training
phase. This pattern of responding was upheld in test phase conditions with
respect to accuracy but observed in RT only in test phase conditions involving
high demand and the auditory modality. Using the experiment as a specific
example, we argue for the importance of considering the cognitive contribution
of the user (viz., prior learned associations) in the warning design process.
Drawing on semiotics and cognitive psychology, we highlight the indexical nature
of so-called auditory icons or natural
indicators and argue that the cogniser is an indispensable element
in the tripartite nature of signification
The impact of complications and errors on surgeons
All surgical procedures carry with them the potential for adverse events. Dealing with the sequelae of the complications and errors that arise in the course of normal practice is therefore part and parcel of a surgeon’s working life. The challenges and stresses that this creates are now well recognised although surgical training has, until recently, done little to help surgeons prepare for such events and on-going professional and personal support is limited. This review shows that much of the research examining the impact of adverse events has been concentrated in healthcare systems outside of the UK, often markedly different to our own. With notable exceptions, sample sizes are often small and studies are often qualitative. While the latter provide rich and fascinating data, they may not always be representative, particularly if the focus is on serious errors where there is a risk of litigation. Despite the preponderance of complications, which are an acknowledged risk of surgical procedures, there is no research to date which has examined whether or not there are differences in the impact of complications versus errors on surgeons’ professional and personal lives. A national survey is currently planned to provide detailed information about the impact of adverse events – both complications and errors – which will map the way for better targeted support for surgeons to help them use their experiences to enhance their wellbeing and improve their practice
Many-body Effects in Angle-resolved Photoemission: Quasiparticle Energy and Lifetime of a Mo(110) Surface State
In a high-resolution photoemission study of a Mo(110) surface state various
contributions to the measured width and energy of the quasiparticle peak are
investigated. Electron-phonon coupling, electron-electron interactions and
scattering from defects are all identified mechanisms responsible for the
finite lifetime of a valence photo-hole. The electron-phonon induced mass
enhancement and rapid change of the photo-hole lifetime near the Fermi level
are observed for the first time.Comment: RevTEX, 4 pages, 4 figures, to be published in PR
Influence of Phytohormones on Monosaccharide Composition of Polysaccharides from Wheat Suspension Culture
Plant polysaccharides with technical and physiologic traits attract researchers by their high physiological activity in regulation of the growth, development and protective reactions. Cell cultures allow to regulate chemical composition of synthesized substances by changing media composition and are widely used to enhance or change the biosynthesis of metabolites. The aim of this study was to investigate the influence of phytohormones 2,4-dichlorphenoxyacetic acid (2,4 –D) and abscisic acid (ABA) of culture medium on chemical composition of polysaccharides (PS), extracted from cells and extracellular liquid of wheat suspension culture. It was shown for the medium with ABA that monosaccharide composition of extracellular PS mainly represented by glucose (87%), whereas PS isolated from cells were rich for xylose and glucuronic acid. Monosaccharide composition of extracellular PS from media with 2,4-D showed 6-fold increase of arabinose, 8-fold ‒ of galactose, 5-fold ‒ of xylose and glucuronic acid, compared to extracellular PS from ABA medium. Composition of cellular PS from media with 2,4-D were mainly similar to ABA and differed by the increased amount of mannose (3-fold), and galacturonic acid (2,5-fold). Thus, regulative effect of the use of two different types of phytohormones was demonstrated on the biosynthesis of variously composed polysaccharides
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