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Serum Amyloid A in Stable COPD Patients is Associated with the Frequent Exacerbator Phenotype
Background: We sought to determine whether circulating inflammatory biomarkers were associated with the frequent exacerbator phenotype in stable COPD patients ie, those with two or more exacerbations in the previous year.
Methods: Eighty-eight stable, severe, COPD patients (4 females) were assessed for exacerbation frequency, pulmonary function, fraction of expired nitric oxide (FENO); inflammatory variables were measured in venous blood. Logistic regression assessed associations between the frequent exacerbator phenotype and systemic inflammation.
Results: Compared with infrequent exacerbators, frequent exacerbators (n=10; 11.4%) had greater serum concentration (median (25th-75th quartile)) of serum amyloid A (SAA; 134 (84– 178) vs 71 (38– 116) ng/mL; P=0.024), surfactant protein D (SP-D; 15.6 (9.0– 19.3) vs 8.5 (3.6– 14.9) ng/mL; P=0.049) and interleukin-4 (IL-4; 0.12 (0.08– 1.44) vs 0.03 (0.01– 0.10) pg/mL; P=0.001). SAA, SP-D and IL-4 were not significantly correlated with FEV1%predicted or FVC %predicted. After adjusting for sex, age, BMI, FEV1/FVC and smoking pack-years, only SAA remained independently associated with the frequent exacerbator phenotype (OR 1.49[1.09– 2.04]; P=0.012). The odds of being a frequent exacerbator was 18-times greater in the highest SAA quartile (≥ 124.1 ng/mL) than the lowest SAA quartile (≤ 44.1 ng/mL) (OR 18.34[1.30– 258.81]; P=0.031), and there was a significant positive trend of increasing OR with increasing SAA quartile (P=0.008). For SAA, the area under the receiver operating characteristic curve was 0.721 for identification of frequent exacerbators; an SAA cut-off of 87.0 ng/mL yielded an 80% sensitivity and 61.5% specificity.
Conclusion: In stable COPD patients, SAA was independently associated with the frequent exacerbator phenotype, suggesting that SAA may be a useful serum biomarker to inform progression or management in COPD
Computational Model for Urban Growth Using Socioeconomic Latent Parameters
Land use land cover changes (LULCC) are generally modeled using multi-scale
spatio-temporal variables. Recently, Markov Chain (MC) has been used to model
LULCC. However, the model is derived from the proportion of LULCC observed over
a given period and it does not account for temporal factors such as
macro-economic, socio-economic, etc. In this paper, we present a richer model
based on Hidden Markov Model (HMM), grounded in the common knowledge that
economic, social and LULCC processes are tightly coupled. We propose a HMM
where LULCC classes represent hidden states and temporal fac-tors represent
emissions that are conditioned on the hidden states. To our knowledge, HMM has
not been used in LULCC models in the past. We further demonstrate its
integration with other spatio-temporal models such as Logistic Regression. The
integrated model is applied on the LULCC data of Pune district in the state of
Maharashtra (India) to predict and visualize urban LULCC over the past 14
years. We observe that the HMM integrated model has improved prediction
accuracy as compared to the corresponding MC integrated modelComment: 12 page
Oxidation resistance of graphene-coated Cu and Cu/Ni alloy
The ability to protect refined metals from reactive environments is vital to
many industrial and academic applications. Current solutions, however,
typically introduce several negative effects, including increased thickness and
changes in the metal physical properties. In this paper, we demonstrate for the
first time the ability of graphene films grown by chemical vapor deposition to
protect the surface of the metallic growth substrates of Cu and Cu/Ni alloy
from air oxidation. SEM, Raman spectroscopy, and XPS studies show that the
metal surface is well protected from oxidation even after heating at 200
\degree C in air for up to 4 hours. Our work further shows that graphene
provides effective resistance against hydrogen peroxide. This protection method
offers significant advantages and can be used on any metal that catalyzes
graphene growth
Velocity tuning of friction with two trapped atoms
Our ability to control friction remains modest, as our understanding of the underlying microscopic processes is incomplete. Atomic force experiments have provided a wealth of results on the dependence of nanofriction on structure velocity and temperature but limitations in the dynamic range, time resolution, and control at the single-atom level have hampered a description from first principles. Here, using an ion-crystal system with single-atom, single-substrate-site spatial and single-slip temporal resolution we measure the friction force over nearly five orders of magnitude in velocity, and contiguously observe four distinct regimes, while controlling temperature and dissipation. We elucidate the interplay between thermal and structural lubricity for two coupled atoms, and provide a simple explanation in terms of the Peierls–Nabarro potential. This extensive control at the atomic scale enables fundamental studies of the interaction of many-atom surfaces, possibly into the quantum regime
Nanocomposite ZnO–SnO2 Nanofibers Synthesized by Electrospinning Method
We report the characterization of mixed oxides nanocomposite nanofibers of (1 − x) ZnO-(x)SnO2 (x ≤ 0.45) synthesized by electrospinning technique. The diameter of calcined nanofibers depends on Sn content. Other phases like SnO, ZnSnO3, and Zn2SnO4 were absent. Photoluminescence studies show that there is a change in the blue/violet luminescence confirming the presence of Sn in Zn-rich composition. Present study shows that the crystalline nanocomposite nanofibers with stoichiometry of (1 − x)ZnO-(x)SnO2 (x ≤ 0.45) stabilize after the calcination and possess some morphological and optical properties that strongly depend on Sn content
Search for New Hadronic Decays of and Observation of
Ten hadronic final states of the decays are investigated via the
process , using a data sample of events collected with the BESIII detector. The
decay channel is observed for
the first time with a significance of . The corresponding branching
fraction is determined to be (the
first uncertainty is statistical and the second systematical). Evidence for the
decays and is found with a significance of and , respectively. The corresponding branching fractions
(and upper limits) are obtained to be and
. Upper limits on the branching fractions for the final
states , ,
, ,
, , and
are determined at a confidence level of 90\%.Comment: 10 pages, 2 figure
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