1,613 research outputs found
Effects of atmospheric pressure plasma on dye uptake by the surface of wool
A woven pure wool fabric has been exposed to atmospheric pressure plasma for 30 seconds using a pilot-scale. commercial machine. X-ray photoelectron spectral data revealed large increases in oxygen and nitrogen. and a large reduction in carbon. on the surfaces of the plasma-treated fibres. A CIN ratio of 3.55 for plasma-treated wool was consistent with removal of the covalently-bound fatty acids from the surface of the cuticle cells. resulting in exposure of the proteinaceous epicuticle. Dye staining experiments revealed that the back of the fabric had received the same, uniform level of treatment as the face, despite the fact that only the face had been directly exposed to the plasma. Dyes (1 % oww) were applied to fabric at 50°C (liquor ratio =40: 1) and pH values from 3 to 6. The relatively low temperature of 50°C was selected in order to accentuate the effects of plasma on the rate of dye uptake. Under these conditions, dye was adsOibed onto the fibre surfaces, with very little penetration into the fibres. Effects of the plasma treatment on the rate of dyes adsorption were dyespecific. No significant effects of plasma on the rate of dye uptake were observed with relatively hydrophobic dyes, but hydrophilic dyes were adsorbed more rapidly by the plasmatreated fabric. It would appear that for more hydrophobic dyes, hydrophobic effects are more important for the adsorption of dyes by the plasma-treated fibres, even though these fibres were quite hydrophilic. On the other hand. it is concluded that for more hydrophilic dyes, electrostatic effects are more important for adsorption by the plasma-treated fibre.<br /
Solvent Mediated Assembly of Nanoparticles Confined in Mesoporous Alumina
The controlled self-assembly of thiol stabilized gold nanocrystals in a
mediating solvent and confined within mesoporous alumina was probed in situ
with small angle x-ray scattering. The evolution of the self-assembly process
was controlled reversibly via regulated changes in the amount of solvent
condensed from an undersaturated vapor. Analysis indicated that the
nanoparticles self-assembled into cylindrical monolayers within the porous
template. Nanoparticle nearest-neighbor separation within the monolayer
increased and the ordering decreased with the controlled addition of solvent.
The process was reversible with the removal of solvent. Isotropic clusters of
nanoparticles were also observed to form temporarily during desorption of the
liquid solvent and disappeared upon complete removal of liquid. Measurements of
the absorption and desorption of the solvent showed strong hysteresis upon
thermal cycling. In addition, the capillary filling transition for the solvent
in the nanoparticle-doped pores was shifted to larger chemical potential,
relative to the liquid/vapor coexistence, by a factor of 4 as compared to the
expected value for the same system without nanoparticles.Comment: 9 pages, 9 figures, appeared in Phys. Rev.
A behavioural change package to prevent hand dermatitis in nurses working in the national health service (the SCIN trial): study protocol for a cluster randomised controlled trial
BACKGROUND: Hand dermatitis can be a serious health problem in healthcare workers. While a range of skin care strategies and policy directives have been developed in recent years to minimise the risk, their effectiveness and cost-effectiveness remain unclear. Evidence now suggests that psychological theory can facilitate behaviour change with respect to improved hand care practices. Therefore, we will test the hypothesis that a behavioural change intervention to improve hand care, based on the Theory of Planned Behaviour and implementation intentions, coupled with provision of hand moisturisers, can produce a clinically useful reduction in the occurrence of hand dermatitis, when compared to standard care, among nurses working in the UK National Health Service (NHS) who are particularly at risk. Secondary aims will be to assess impacts on participants’ beliefs and behaviour regarding hand care. In addition, we will assess the cost-effectiveness of the intervention in comparison with normal care. METHODS/DESIGN: We will conduct a cluster randomised controlled trial at 35 NHS hospital trusts/health boards/universities, focussing on student nurses with a previous history of atopic disease or hand eczema and on nurses in intensive care units. Nurses at ‘intervention-light’ sites will be managed according to what would currently be regarded as best practice, with provision of an advice leaflet about optimal hand care to prevent hand dermatitis and encouragement to contact their occupational health (OH) department early if hand dermatitis occurs. Nurses at ‘intervention-plus’ sites will additionally receive a behavioural change programme (BCP) with on-going active reinforcement of its messages, and enhanced provision of moisturising cream. The impact of the interventions will be compared using information collected by questionnaires and through standardised photographs of the hands and wrists, collected at baseline and after 12 months follow-up. In addition, we will assemble relevant economic data for an analysis of costs and benefits, and collect information from various sources to evaluate processes. Statistical analysis will be by multi-level regression modelling to allow for clustering by site, and will compare the prevalence of outcome measures at follow-up after adjustment for values at baseline. The principal outcome measure will be the prevalence of visible hand dermatitis as assessed by the study dermatologists. In addition, several secondary outcome measures will be assessed. DISCUSSION: This trial will assess the clinical and cost effectiveness of an intervention to prevent hand dermatitis in nurses in the United Kigdom. TRIAL REGISTRATION: ISRCTN53303171: date of registration, 21 June 2013
A behaviour change package to prevent hand dermatitis in nurses working in health care: the SCIN cluster RCT
BACKGROUND: Although strategies have been developed to minimise the risk of occupational hand dermatitis in nurses, their clinical effectiveness and cost-effectiveness remain unclear. OBJECTIVES: The Skin Care Intervention in Nurses trial tested the hypothesis that a behaviour change package intervention, coupled with provision of hand moisturisers, could reduce the point prevalence of hand dermatitis when compared with standard care among nurses working in the NHS. The secondary aim was to assess the impact of the intervention on participants' beliefs and behaviour regarding hand care, and the cost-effectiveness of the intervention in comparison with normal care. DESIGN: Cluster randomised controlled trial. SETTING: Thirty-five NHS hospital trusts/health boards/universities. PARTICIPANTS: First-year student nurses with a history of atopic tendency, and full-time intensive care unit nurses. INTERVENTION: Sites were randomly allocated to be 'intervention plus' or 'intervention light'. Participants at 'intervention plus' sites received access to a bespoke online behaviour change package intervention, coupled with personal supplies of moisturising cream (student nurses) and optimal availability of moisturising cream (intensive care unit nurses). Nurses at 'intervention light' sites received usual care, including a dermatitis prevention leaflet. MAIN OUTCOME MEASURE: The difference between intervention plus and intervention light sites in the change of point prevalence of visible hand dermatitis was measured from images taken at baseline and at follow-up. RANDOMISATION: Fourteen sites were randomised to the intervention plus arm, and 21 sites were randomised to the intervention light arm. BLINDING: The participants, trial statistician, methodologist and the dermatologists interpreting the hand photographs were blinded to intervention assignment. NUMBERS ANALYSED: An intention-to-treat analysis was conducted on data from 845 student nurses and 1111 intensive care unit nurses. RESULTS: The intention-to-treat analysis showed no evidence that the risk of developing dermatitis was greater in the intervention light group than in the intervention plus group (student nurses: odds ratio 1.25, 95% confidence interval 0.59 to 2.69; intensive care unit nurses: odds ratio 1.41, 95% confidence interval 0.81 to 2.44). Both groups had high levels of baseline beliefs about the benefits of using hand moisturisers before, during and after work. The frequency of use of hand moisturisers before, during and after shifts was significantly higher in the intensive care unit nurses in the intervention plus arm at follow-up than in the comparator group nurses. For student nurses, the intervention plus group mean costs were £2 lower than those for the comparator and 0.00002 more quality-adjusted life-years were gained. For intensive care unit nurses, costs were £4 higher and 0.0016 fewer quality-adjusted life-years were gained. HARMS: No adverse events were reported. LIMITATIONS: Only 44.5% of participants in the intervention plus arm accessed the behaviour change package. CONCLUSION: The intervention did not result in a statistically significant decrease in the prevalence of hand dermatitis in the intervention plus group. FUTURE WORK: Participants had a high level of baseline beliefs about the importance of using hand moisturisers before, during and after work. Future research should focus on how workplace culture can be changed in order for that knowledge to be actioned. TRIAL REGISTRATION: Current Controlled Trials ISRCTN53303171. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 58. See the NIHR Journals Library website for further project information
Androgen receptor phosphorylation at serine 515 by Cdk1 predicts biochemical relapse in prostate cancer patients
<br>Background:Prostate cancer cell growth is dependent upon androgen receptor (AR) activation, which is regulated by specific kinases. The aim of the current study is to establish if AR phosphorylation by Cdk1 or ERK1/2 is of prognostic significance.</br> <br>Methods: Scansite 2.0 was utilised to predict which AR sites are phosphorylated by Cdk1 and ERK1/2. Immunohistochemistry for these sites was then performed on 90 hormone-naive prostate cancer specimens. The interaction between Cdk1/ERK1/2 and AR phosphorylation was investigated in vitro using LNCaP cells.</br><br>Results:Phosphorylation of AR at serine 515 (pAR(S515)) and PSA at diagnosis were independently associated with decreased time to biochemical relapse. Cdk1 and pCdk1(161), but not ERK1/2, correlated with pAR(S515). High expression of pAR(S515) in patients with a PSA at diagnosis of ≤20 ng ml(-1) was associated with shorter time to biochemical relapse (P=0.019). This translated into a reduction in disease-specific survival (10-year survival, 38.1% vs 100%, P<0.001). In vitro studies demonstrated that treatment with Roscovitine (a Cdk inhibitor) caused a reduction in pCdk1(161) expression, pAR(S515)expression and cellular proliferation.</br> <br>Conclusion: In prostate cancer patients with PSA at diagnosis of ≤20 ng ml(-1), phosphorylation of AR at serine 515 by Cdk1 may be an independent prognostic marker.</br>
PAK6 Phosphorylates 14-3-3 gamma to Regulate Steady State Phosphorylation of LRRK2
Mutations in Leucine-rich repeat kinase 2 (LRRK2) are associated with Parkinson’s
disease (PD) and, as such, LRRK2 is considered a promising therapeutic target for
age-related neurodegeneration. Although the cellular functions of LRRK2 in health and
disease are incompletely understood, robust evidence indicates that PD-associated
mutations alter LRRK2 kinase and GTPase activities with consequent deregulation of
the downstream signaling pathways. We have previously demonstrated that one LRRK2
binding partner is P21 (RAC1) Activated Kinase 6 (PAK6). Here, we interrogate the
PAK6 interactome and find that PAK6 binds a subset of 14-3-3 proteins in a kinase
dependent manner. Furthermore, PAK6 efficiently phosphorylates 14-3-3γ at Ser59 and
this phosphorylation serves as a switch to dissociate the chaperone from client proteins
including LRRK2, a well-established 14-3-3 binding partner. We found that 14-3-3γ
phosphorylated by PAK6 is no longer competent to bind LRRK2 at phospho-Ser935,
causing LRRK2 dephosphorylation. To address whether these interactions are relevant in
a neuronal context, we demonstrate that a constitutively active form of PAK6 rescues the
G2019S LRRK2-associated neurite shortening through phosphorylation of 14-3-3γ. Our
results identify PAK6 as the kinase for 14-3-3γ and reveal a novel regulatory mechanism
of 14-3-3/LRRK2 complex in the brain
Robustness of circadian clocks to daylight fluctuations: hints from the picoeucaryote Ostreococcus tauri
The development of systemic approaches in biology has put emphasis on
identifying genetic modules whose behavior can be modeled accurately so as to
gain insight into their structure and function. However most gene circuits in a
cell are under control of external signals and thus quantitative agreement
between experimental data and a mathematical model is difficult. Circadian
biology has been one notable exception: quantitative models of the internal
clock that orchestrates biological processes over the 24-hour diurnal cycle
have been constructed for a few organisms, from cyanobacteria to plants and
mammals. In most cases, a complex architecture with interlocked feedback loops
has been evidenced. Here we present first modeling results for the circadian
clock of the green unicellular alga Ostreococcus tauri. Two plant-like clock
genes have been shown to play a central role in Ostreococcus clock. We find
that their expression time profiles can be accurately reproduced by a minimal
model of a two-gene transcriptional feedback loop. Remarkably, best adjustment
of data recorded under light/dark alternation is obtained when assuming that
the oscillator is not coupled to the diurnal cycle. This suggests that coupling
to light is confined to specific time intervals and has no dynamical effect
when the oscillator is entrained by the diurnal cycle. This intringuing
property may reflect a strategy to minimize the impact of fluctuations in
daylight intensity on the core circadian oscillator, a type of perturbation
that has been rarely considered when assessing the robustness of circadian
clocks
Differential cargo mobilisation within Weibel-Palade bodies after transient fusion with the plasma membrane.
Inflammatory chemokines can be selectively released from Weibel-Palade bodies (WPBs) during kiss-and-run exocytosis. Such selectivity may arise from molecular size filtering by the fusion pore, however differential intra-WPB cargo re-mobilisation following fusion-induced structural changes within the WPB may also contribute to this process. To determine whether WPB cargo molecules are differentially re-mobilised, we applied FRAP to residual post-fusion WPB structures formed after transient exocytosis in which some or all of the fluorescent cargo was retained. Transient fusion resulted in WPB collapse from a rod to a spheroid shape accompanied by substantial swelling (>2 times by surface area) and membrane mixing between the WPB and plasma membranes. Post-fusion WPBs supported cumulative WPB exocytosis. To quantify diffusion inside rounded organelles we developed a method of FRAP analysis based on image moments. FRAP analysis showed that von Willebrand factor-EGFP (VWF-EGFP) and the VWF-propolypeptide-EGFP (Pro-EGFP) were immobile in post-fusion WPBs. Because Eotaxin-3-EGFP and ssEGFP (small soluble cargo proteins) were largely depleted from post-fusion WPBs, we studied these molecules in cells preincubated in the weak base NH4Cl which caused WPB alkalinisation and rounding similar to that produced by plasma membrane fusion. In these cells we found a dramatic increase in mobilities of Eotaxin-3-EGFP and ssEGFP that exceeded the resolution of our method (∼ 2.4 µm2/s mean). In contrast, the membrane mobilities of EGFP-CD63 and EGFP-Rab27A in post-fusion WPBs were unchanged, while P-selectin-EGFP acquired mobility. Our data suggest that selective re-mobilisation of chemokines during transient fusion contributes to selective chemokine secretion during transient WPB exocytosis. Selective secretion provides a mechanism to regulate intravascular inflammatory processes with reduced risk of thrombosis
- …