831 research outputs found
User experiences of digital prostheses in daily functioning in people with an amputation of thumb or finger
Study Design
Qualitative research design using interpretative phenomenological analysis (IPA) to interpret usersâ experiences with digital prostheses.
Background
Digital prostheses are rarely used, and little is known about the experiences of traumatic finger amputees with digital prostheses. When advising patients regarding digital prostheses, it is crucial for professionals to understand users experiences of wearing a digital prosthesis and the meaning attached to wearing a digital prosthesis.
Purpose of study
The aim of this study was to explore and understand users experiences of wearing a digital prostheses in daily functioning.
Methods
Individual semi-structured interviews were conducted, recorded, and transcribed. The written interview texts were analysed following Interpretative phenomenological analysis guidelines.
Results
Four participants were interviewed. They experienced the prostheses as valuable additions to their daily functioning. Three different themes relating to wearing and using digital prostheses emerged from in-depth analysis of the data: How the prosthesis supporting them regaining a âgripâ on life, reduced overload on unaffected side and restored body image.
Conclusions
This study provides a deeper understanding of the experiences of people with digital amputations who use prostheses. Most importantly, that a prosthesis is of crucial importance for participants to be able to act independently and autonomously as well as to participate in family, work and social environments. This insight will help practitioners when considering, with clients the most appropriate digital prosthesis to meet their goals
Relativistically rotating dust
Dust configurations play an important role in astrophysics and are the
simplest models for rotating bodies. The physical properties of the
general--relativistic global solution for the rigidly rotating disk of dust,
which has been found recently as the solution of a boundary value problem, are
discussed.Comment: 18 pages, 11 figure
Memantine treatment does not affect compulsive behavior or frontostriatal connectivity in an adolescent rat model for quinpirole-induced compulsive checking behavior
RATIONALE: Compulsivity often develops during childhood and is associated with elevated glutamate levels within the frontostriatal system. This suggests that anti-glutamatergic drugs, like memantine, may be an effective treatment.
OBJECTIVE: Our goal was to characterize the acute and chronic effect of memantine treatment on compulsive behavior and frontostriatal network structure and function in an adolescent rat model of compulsivity.
METHODS: Juvenile Sprague-Dawley rats received repeated quinpirole, resulting in compulsive checking behavior (nâ=â32; compulsive) or saline injections (nâ=â32; control). Eight compulsive and control rats received chronic memantine treatment, and eight compulsive and control rats received saline treatment for seven consecutive days between the 10th and 12th quinpirole/saline injection. Compulsive checking behavior was assessed, and structural and functional brain connectivity was measured with diffusion MRI and resting-state fMRI before and after treatment. The other rats received an acute single memantine (compulsive: nâ=â12; control: nâ=â12) or saline injection (compulsive: nâ=â4; control: nâ=â4) during pharmacological MRI after the 12th quinpirole/saline injection. An additional group of rats received a single memantine injection after a single quinpirole injection (nâ=â8).
RESULTS: Memantine treatment did not affect compulsive checking nor frontostriatal structural and functional connectivity in the quinpirole-induced adolescent rat model. While memantine activated the frontal cortex in control rats, no significant activation responses were measured after single or repeated quinpirole injections.
CONCLUSIONS: The lack of a memantine treatment effect in quinpirole-induced compulsive adolescent rats may be partly explained by the interaction between glutamatergic and dopaminergic receptors in the brain, which can be evaluated with functional MRI
Changes in subcellular doxorubicin distribution and cellular accumulation alone can largely account for doxorubicin resistance in SW-1573 lung cancer and MCF-7 breast cancer multidrug resistant tumour cells.
Doxorubicin accumulation defects in multidrug resistant tumour cells are generally small in comparison to the resistance factors. Therefore additional mechanisms must be operative. In this paper we show by a quantitative approach that doxorubicin resistance in several P-glycoprotein-positive non-small cell lung cancer and breast cancer multidrug resistant cell lines can be explained by a summation of accumulation defect and alterations in the efficacy of the drug once present in the cell. This alteration of efficacy was partly due to changes in intracellular drug localisation, characterised by decreased nuclear/cytoplasmic doxorubicin fluorescence ratios (N/C-ratios). N/C-ratios were 2.8-3.6 in sensitive cells, 0.1-0.4 in cells with high (> 70-fold) levels of doxorubicin resistance and 1.2 and 1.9 in cells with low or intermediate (7.5 and 24-fold, respectively) levels of doxorubicin resistance. The change of drug efficacy was reflected by an increase in the total amount of doxorubicin present in the cell at equitoxic (IC50) concentrations. N/C ratios in highly resistant P-glycoprotein-containing cells could be increased with the resistance modifier verapamil to values of 1.3-2.7, a process that was paralleled by a decrease of the cellular doxorubicin amounts present at IC50. At the low to moderate residual levels of resistance, obtained with different concentrations of verapamil, a linear relationship between IC50 and cellular doxorubicin amounts determined at IC50 was found. This shows that at this stage of residual resistance, extra reversal by verapamil should be explained by further increase of drug efficacy rather than by increase of cellular drug accumulation. A similar relationship was found for P-glycoprotein-negative MDR cells with low levels of resistance. Since in these cells N/C ratios could not be altered, verapamil-induced decrease of IC50 must be due to increased drug efficacy by action on as yet unidentified targets. Although the IC50 of sensitive human cells cannot be reached with resistance modifiers, when using these relationships it can be shown by extrapolation that cellular and nuclear doxorubicin amounts at IC50 at complete reversal of resistance were the same as in sensitive cells. It is concluded that doxorubicin resistance factors for multidrug resistant cells can for a large part, and in the case of P-glycoprotein-containing cells probably fully, be accounted for by decreased amounts of drug at nuclear targets, which in turn is characterised by two processes only: decreased cellular accumulation and a shift in the ratio nuclear drug/cytoplasmic drug
Propofol anesthesia improves stroke outcomes over isoflurane anesthesiaâa longitudinal multiparametric MRI study in a rodent model of transient middle cerebral artery occlusion
General anesthesia is routinely used in endovascular thrombectomy procedures, for which volatile gas and/or intravenous propofol are recommended. Emerging evidence suggests propofol may have superior effects on disability and/or mortality rates, but a mode-of-action underlying these class-specific effects remains unknown. Here, a moderate isoflurane or propofol dosage on experimental stroke outcomes was retrospectively compared using serial multiparametric MRI and behavioral testing. Adult male rats (Nâ=â26) were subjected to 90-min filament-induced transient middle cerebral artery occlusion. Diffusion-, T2- and perfusion-weighted MRI was performed during occlusion, 0.5âh after recanalization, and four days into the subacute phase. Sequels of ischemic damageâbloodâbrain barrier integrity, cerebrovascular reactivity and sensorimotor functioningâwere assessed after four days. While size and severity of ischemia was comparable between groups during occlusion, isoflurane anesthesia was associated with larger lesion sizes and worsened sensorimotor functioning at follow-up. MRI markers indicated that cytotoxic edema persisted locally in the isoflurane group early after recanalization, coinciding with burgeoning vasogenic edema. At follow-up, sequels of ischemia were further aggravated in the post-ischemic lesion, manifesting as increased bloodâbrain barrier leakage, cerebrovascular paralysis and cerebral hyperperfusion. These findings shed new light on how isoflurane, and possibly similar volatile agents, associate with persisting injurious processes after recanalization that contribute to suboptimal treatment outcome
Extracellular matrix defects in aneurysmal Fibulin-4 mice predispose to lung emphysema
Background: In this study we set out to investigate the clinically observed relationship between chronic obstructive pulmonary disease (COPD) and aortic aneurysms. We tested the hypothesis that an
Intracerebroventricular Administration of Neuropeptide Y Induces Hepatic Insulin Resistance via Sympathetic Innervation
OBJECTIVEâWe recently showed that intracerebroventricular infusion of neuropeptide Y (NPY) hampers inhibition of endogenous glucose production (EGP) by insulin in mice. The downstream mechanisms responsible for these effects of NPY remain to be elucidated. Therefore, the aim of this study was to establish whether intracerebroventricular NPY administration modulates the suppressive action of insulin on EGP via hepatic sympathetic or parasympathetic innervation
Reconstruction of the gravitational wave signal during the Virgo science runs and independent validation with a photon calibrator
The Virgo detector is a kilometer-scale interferometer for gravitational wave
detection located near Pisa (Italy). About 13 months of data were accumulated
during four science runs (VSR1, VSR2, VSR3 and VSR4) between May 2007 and
September 2011, with increasing sensitivity.
In this paper, the method used to reconstruct, in the range 10 Hz-10 kHz, the
gravitational wave strain time series from the detector signals is
described. The standard consistency checks of the reconstruction are discussed
and used to estimate the systematic uncertainties of the signal as a
function of frequency. Finally, an independent setup, the photon calibrator, is
described and used to validate the reconstructed signal and the
associated uncertainties.
The uncertainties of the time series are estimated to be 8% in
amplitude. The uncertainty of the phase of is 50 mrad at 10 Hz with a
frequency dependence following a delay of 8 s at high frequency. A bias
lower than and depending on the sky direction of the GW is
also present.Comment: 35 pages, 16 figures. Accepted by CQ
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