571 research outputs found
Is nebulized saline a placebo in COPD?
BACKGROUND: Many trials of nebulized therapy have used nebulized saline as a "placebo". However, nebulized isotonic saline is sometimes used to assist sputum expectoration and relieve breathlessness in COPD patients. We designed this study to establish if nebulized saline had a placebo effect or a clinical effect. METHODS: 40 patients were studied following hospital admission for exacerbated COPD (mean FEV1 30% predicted). Patients were randomised to single-blind administration of either 4 mls of nebulized isotonic saline using an efficient nebulizer (active group n = 20) or an inefficient nebulizer (placebo group n = 20). Spirometry and subjective breathlessness scores (Modified Likert Scale) were measured before nebulized treatment and 10 minutes after treatment. RESULTS: There was no significant change in FEV1 after active or placebo nebulized saline treatment. Patients reported a 4% improvement in mean breathlessness score following placebo (Wilcoxon test; p = 0.37) compared with 23% improvement following active nebulized saline (p = 0.0001). 65% of patients given active nebulized saline but only 5% of the placebo group reported that mucus expectoration was easier after the treatment. CONCLUSIONS: This study lends support to the current use of nebulized saline to relieve breathlessness (possibly by facilitating sputum clearance) in COPD patients. Lung function was not affected. Nebulized saline can therefore be used as a placebo in bronchodilator studies involving COPD patients but it cannot be used as a placebo in trials assessing symptom relief
Selected reactive oxygen species and antioxidant enzymes in common bean after Pseudomonas syringae pv. phaseolicola and Botrytis cinerea infection
Phaseolus vulgaris cv. Korona plants were
inoculated with the bacteria Pseudomonas syringae pv.
phaseolicola (Psp), necrotrophic fungus Botrytis cinerea
(Bc) or with both pathogens sequentially. The aim of the
experiment was to determine how plants cope with multiple
infection with pathogens having different attack strategy.
Possible suppression of the non-specific infection with
the necrotrophic fungus Bc by earlier Psp inoculation was
examined. Concentration of reactive oxygen species
(ROS), such as superoxide anion (O2
-) and H2O2 and
activities of antioxidant enzymes such as superoxide dismutase
(SOD), catalase (CAT) and peroxidase (POD) were
determined 6, 12, 24 and 48 h after inoculation. The
measurements were done for ROS cytosolic fraction and
enzymatic cytosolic or apoplastic fraction. Infection with
Psp caused significant increase in ROS levels since the
beginning of experiment. Activity of the apoplastic
enzymes also increased remarkably at the beginning of
experiment in contrast to the cytosolic ones. Cytosolic
SOD and guaiacol peroxidase (GPOD) activities achieved
the maximum values 48 h after treatment. Additional forms
of the examined enzymes after specific Psp infection were
identified; however, they were not present after single Bc
inoculation. Subsequent Bc infection resulted only in
changes of H2O2 and SOD that occurred to be especially
important during plant–pathogen interaction. Cultivar Korona
of common bean is considered to be resistant to Psp and mobilises its system upon infection with these bacteria.
We put forward a hypothesis that the extent of defence
reaction was so great that subsequent infection did not
trigger significant additional response
Wheat-barley hybridization – the last forty years
Abstract Several useful alien gene transfers have
been reported from related species into wheat (Triticum
aestivum), but very few publications have dealt
with the development of wheat/barley (Hordeum
vulgare) introgression lines. An overview is given
here of wheat 9 barley hybridization over the last
forty years, including the development of
wheat 9 barley hybrids, and of addition and translocation
lines with various barley cultivars. A short
summary is also given of the wheat 9 barley hybrids
produced with other Hordeum species. The meiotic
pairing behaviour of wheat 9 barley hybrids is presented,
with special regard to the detection of wheat–
barley homoeologous pairing using the molecular
cytogenetic technique GISH. The effect of in vitro
multiplication on the genome composition of intergeneric
hybrids is discussed, and the production and
characterization of the latest wheat/barley translocation
lines are presented. An overview of the agronomical
traits (b-glucan content, earliness, salt tolerance,
sprouting resistance, etc.) of the newly developed
introgression lines is given. The exploitation and
possible use of wheat/barley introgression lines for
the most up-to-date molecular genetic studies
(transcriptome analysis, sequencing of flow-sorted
chromosomes) are also discussed
Regional variations in and correlates of disability-free life expectancy among older adults in China
<p>Abstract</p> <p>Background</p> <p>Considerable socioeconomic and health inequalities have been reported in China. However, because of a lack of appropriate data, limited research has been conducted on variations in disability-free life expectancy (DFLE) among older adults. This study aimed to use the most up-to-date disability survey data to explore geographical variations in DFLE at age 60 in China and to identify the socioeconomic and health care factors that partially account for these variations.</p> <p>Methods</p> <p>This study used 2006 mortality data extrapolated from the 1990 and 2000 Census and disability data from a national disability survey conducted in 2006. Disability was performance based and was diagnosed by trained physicians. DFLE was calculated by region using the Sullivan method. Multiple linear regression models by gender were conducted to explore correlates of DFLE.</p> <p>Results</p> <p>DFLE at age 60 varied widely by region, from 11.2 to 20.8 years in 2006. Per capita gross domestic product, proportion of urban residents, and access to health care were the primary factors associated with geographical variations in DFLE.</p> <p>Conclusion</p> <p>The pattern of differences in DFLE by region mirrors the pattern of regional economic development in China. Countermeasures to decrease regional differences in DFLE include accelerating regional economic development and improving health care distribution.</p
Combining specificity determining and conserved residues improves functional site prediction
<p>Abstract</p> <p>Background</p> <p>Predicting the location of functionally important sites from protein sequence and/or structure is a long-standing problem in computational biology. Most current approaches make use of sequence conservation, assuming that amino acid residues conserved within a protein family are most likely to be functionally important. Most often these approaches do not consider many residues that act to define specific sub-functions within a family, or they make no distinction between residues important for function and those more relevant for maintaining structure (e.g. in the hydrophobic core). Many protein families bind and/or act on a variety of ligands, meaning that conserved residues often only bind a common ligand sub-structure or perform general catalytic activities.</p> <p>Results</p> <p>Here we present a novel method for functional site prediction based on identification of conserved positions, as well as those responsible for determining ligand specificity. We define Specificity-Determining Positions (SDPs), as those occupied by conserved residues within sub-groups of proteins in a family having a common specificity, but differ between groups, and are thus likely to account for specific recognition events. We benchmark the approach on enzyme families of known 3D structure with bound substrates, and find that in nearly all families residues predicted by SDPsite are in contact with the bound substrate, and that the addition of SDPs significantly improves functional site prediction accuracy. We apply SDPsite to various families of proteins containing known three-dimensional structures, but lacking clear functional annotations, and discusse several illustrative examples.</p> <p>Conclusion</p> <p>The results suggest a better means to predict functional details for the thousands of protein structures determined prior to a clear understanding of molecular function.</p
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Does the Angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism modify the response to ACE inhibitor therapy? – A systematic review
BACKGROUND: Pharmacogenetic testing to individualize ACE inhibitor therapy remains controversial. We conducted a systematic review to assess the effect modification of the insertion/deletion (I/D) polymorphism of the ACE gene on any outcome in patients treated with ACE inhibitors for cardiovascular and/or renal disease. METHODS: Our systematic review involved searching six electronic databases, then contacting the investigators (and pharmaceutical industry representatives) responsible for the creation of these databases. Two reviewers independently selected relevant randomized, placebo-controlled trials and abstracted from each study details on characteristics and quality. RESULTS: Eleven studies met our inclusion criteria. Despite repeated efforts to contact authors, only four of the eleven studies provided sufficient data to quantify the effect modification by genotypes. We observed a trend towards better response to ACE inhibitors in Caucasian DD carriers compared to II carriers, in terms of blood pressure, proteinuria, glomerular filtration rate, ACE activity and progression to end-stage renal failure. Pooling of the results was inappropriate, due to heterogeneity in ethnicity, clinical domains and outcomes. CONCLUSION: Lack of sufficient genetic data from the reviewed studies precluded drawing any convincing conclusions. Better reporting of genetic data are needed to confirm our preliminary observations concerning better response to ACE inhibitors among Caucasian DD carriers as compared to II carriers
Transparency and Trust in Human-AI-Interaction: The Role of Model-Agnostic Explanations in Computer Vision-Based Decision Support
Computer Vision, and hence Artificial Intelligence-based extraction of
information from images, has increasingly received attention over the last
years, for instance in medical diagnostics. While the algorithms' complexity is
a reason for their increased performance, it also leads to the "black box"
problem, consequently decreasing trust towards AI. In this regard, "Explainable
Artificial Intelligence" (XAI) allows to open that black box and to improve the
degree of AI transparency. In this paper, we first discuss the theoretical
impact of explainability on trust towards AI, followed by showcasing how the
usage of XAI in a health-related setting can look like. More specifically, we
show how XAI can be applied to understand why Computer Vision, based on deep
learning, did or did not detect a disease (malaria) on image data (thin blood
smear slide images). Furthermore, we investigate, how XAI can be used to
compare the detection strategy of two different deep learning models often used
for Computer Vision: Convolutional Neural Network and Multi-Layer Perceptron.
Our empirical results show that i) the AI sometimes used questionable or
irrelevant data features of an image to detect malaria (even if correctly
predicted), and ii) that there may be significant discrepancies in how
different deep learning models explain the same prediction. Our theoretical
discussion highlights that XAI can support trust in Computer Vision systems,
and AI systems in general, especially through an increased understandability
and predictability
Soft network composite materials with deterministic and bio-inspired designs
Hard and soft structural composites found in biology provide inspiration for the design of advanced synthetic materials. Many examples of bio-inspired hard materials can be found in the literature; far less attention has been devoted to soft systems. Here we introduce deterministic routes to low-modulus thin film materials with stress/strain responses that can be tailored precisely to match the non-linear properties of biological tissues, with application opportunities that range from soft biomedical devices to constructs for tissue engineering. The approach combines a low-modulus matrix with an open, stretchable network as a structural reinforcement that can yield classes of composites with a wide range of desired mechanical responses, including anisotropic, spatially heterogeneous, hierarchical and self-similar designs. Demonstrative application examples in thin, skin-mounted electrophysiological sensors with mechanics precisely matched to the human epidermis and in soft, hydrogel-based vehicles for triggered drug release suggest their broad potential uses in biomedical devices. &#169; 2015 Macmillan Publishers Limited. All rights reservedopen7
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