281 research outputs found
Improved unsupervised physics-informed deep learning for intravoxel incoherent motion modeling and evaluation in pancreatic cancer patients
: Earlier work showed that IVIM-NET, an unsupervised
physics-informed deep neural network, was more accurate than other
state-of-the-art intravoxel-incoherent motion (IVIM) fitting approaches to DWI.
This study presents an improved version: IVIM-NET, and characterizes
its superior performance in pancreatic ductal adenocarcinoma (PDAC) patients.
: In simulations (SNR=20), the accuracy, independence and
consistency of IVIM-NET were evaluated for combinations of hyperparameters (fit
S0, constraints, network architecture, # hidden layers, dropout, batch
normalization, learning rate), by calculating the NRMSE, Spearman's , and
the coefficient of variation (CV), respectively. The best performing
network, IVIM-NET was compared to least squares (LS) and a Bayesian
approach at different SNRs. IVIM-NET's performance was evaluated in
23 PDAC patients. 14 of the patients received no treatment between scan
sessions and 9 received chemoradiotherapy between sessions. Intersession
within-subject standard deviations (wSD) and treatment-induced changes were
assessed. : In simulations, IVIM-NET outperformed
IVIM-NET in accuracy (NRMSE(D)=0.18 vs 0.20; NMRSE(f)=0.22 vs 0.27;
NMRSE(D*)=0.39 vs 0.39), independence ((D*,f)=0.22 vs 0.74) and
consistency (CV (D)=0.01 vs 0.10; CV (f)=0.02 vs 0.05;
CV (D*)=0.04 vs 0.11). IVIM-NET showed superior performance
to the LS and Bayesian approaches at SNRs<50. In vivo, IVIM-NET
sshowed significantly less noisy parameter maps with lower wSD for D and f than
the alternatives. In the treated cohort, IVIM-NET detected the most
individual patients with significant parameter changes compared to day-to-day
variations. : IVIM-NET is recommended for IVIM
fitting to DWI data
Simvastatin improves the sexual health-related quality of life in men aged 40 years and over with erectile dysfunction : Additional data from the Erectile Dysfunction and Statin trial
© 2014 Trivedi et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.Background: Erectile dysfunction is prevalent in men over 40 years, affecting their quality of life and that of their partners. The aims of this study were:a)To evaluate the internal reliability of the male erectile dysfunction specific quality of life (MED-QoL) scale and explore its factor structure.b)To evaluate the effect of simvastatin on subscales of the MED-QoL in men over forty years with erectile dysfunction. Methods: This is a double blind randomised controlled trial of 40 mg simvastatin or placebo given once daily for six months to men over forty years with untreated erectile dysfunction, who were not at high cardiovascular risk and were not on anti-hypertensive or lipid-lowering medication. 173 eligible men were recruited from 10 general practices in East of England. Data were collected at two points over 30 weeks. We report on the factor structure of MED-QoL, the internal reliability of the scale and the derived subscales, and the effect of simvastatin on MED-QoL subscales. Results: An initial analysis of the MED-QoL items suggested that a number of items should be removed (MED-QoL-R). Exploratory factor analysis identified three subscales within the MED-QoL-R which accounted for 96% of the variance, related to feelings of Control, initiating Intimacy, and Emotional response to erectile dysfunction. The alpha value for the revised scale (MED-Qol-R) was >0.95 and exceeded .82 for each subscale. Regression analysis showed that patients in the placebo group experienced a significantly reduced feeling of Control over erectile dysfunction than those in the statin group. Those in the placebo group had significantly lower Emotional response than those in the statin group at the close of trial, but there was no significant treatment effect on Intimacy. Conclusions: Our revised MED-QoL-R identified three subscales. Secondary analysis showed a significant improvement in sexual health related quality of life, specifically in relation to perception of control and emotional health in men with untreated erectile dysfunction given 40 mg simvastatin for six months. Trial registration: Current Controlled Trials ISRCTN66772971.Peer reviewe
Evaluating case studies of community-oriented integrated care.
This paper summarises a ten-year conversation within London Journal of Primary Care about the nature of community-oriented integrated care (COIC) and how to develop and evaluate it. COIC means integration of efforts for combined disease-treatment and health-enhancement at local, community level. COIC is similar to the World Health Organisation concept of a Community-Based Coordinating Hub - both require a local geographic area where different organisations align their activities for whole system integration and develop local communities for health. COIC is a necessary part of an integrated system for health and care because it enables multiple insights into 'wicked problems', and multiple services to integrate their activities for people with complex conditions, at the same time helping everyone to collaborate for the health of the local population. The conversation concludes seven aspects of COIC that warrant further attention
Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches
The LUX-ZEPLIN (LZ) experiment will search for dark matter particle
interactions with a detector containing a total of 10 tonnes of liquid xenon
within a double-vessel cryostat. The large mass and proximity of the cryostat
to the active detector volume demand the use of material with extremely low
intrinsic radioactivity. We report on the radioassay campaign conducted to
identify suitable metals, the determination of factors limiting radiopure
production, and the selection of titanium for construction of the LZ cryostat
and other detector components. This titanium has been measured with activities
of U~1.6~mBq/kg, U~0.09~mBq/kg,
Th~~mBq/kg, Th~~mBq/kg, K~0.54~mBq/kg, and Co~0.02~mBq/kg (68\% CL).
Such low intrinsic activities, which are some of the lowest ever reported for
titanium, enable its use for future dark matter and other rare event searches.
Monte Carlo simulations have been performed to assess the expected background
contribution from the LZ cryostat with this radioactivity. In 1,000 days of
WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute
only a mean background of (stat)(sys) counts.Comment: 13 pages, 3 figures, accepted for publication in Astroparticle
Physic
The Longitudinal Relationship Between Satisfaction with Transitional Care and Social and Emotional Quality of Life Among Chronically Ill Adolescents
This study aimed to identify the relationship between satisfaction with transitional care and quality of life of chronically ill adolescents over time. This longitudinal study included adolescents with type I diabetes, juvenile idiopathic arthritis (JIA), and neuromuscular disorders (NMD). At baseline 138 respondents (response rate 31 %) filled in a questionnaire and 188 about 1 year later (response rate 43 %). Analysis of variance showed that adolescents with diabetes reported the highest physical quality of life, followed in order by those with NMD and JIA (p ≤ 0.01). Adolescents with diabetes reported the highest social quality of life, followed in order by those with JIA and NMD (both at p ≤ 0.001). Univariate analyses showed that satisfaction with transitional care at T0 was significantly related to emotional and physical quality of life at T1 (both at p ≤ 0.05). At T1, satisfaction with transitional care was significantly related to the emotional, physical, and social domains of quality of life (all at p ≤ 0.001). Multiple regression analyses revealed that satisfaction with transitional care at T1 was related to emotional (β -0.20; p ≤ 0.05) and social (β -0.35; p ≤ 0.01) quality of life domains over time. This indicates that lower gap scores, which measured differences between 'best care' and 'current care,' are associated with better social and emotional quality of life in this sample of adolescents. Satisfaction with transitional care and social and emotional quality of life are related over time
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