Ultrafast carrier phonon dynamics in NaOH-reacted graphite oxide film

NaOH-reacted graphite oxide film was prepared by decomposing epoxy groups in graphite oxide into hydroxyl and -ONa groups with NaOH solution. Ultrafast carrier dynamics of the sample were studied by time-resolved transient differential reflection (\DeltaR/R). The data show two exponential relaxation processes. The slow relaxation process (\sim2ps) is ascribed to low energy acoustic phonon mediated scattering. The electron-phonon coupling and first-principles calculation results demonstrate that - OH and -ONa groups in the sample are strongly coupled. Thus, we attribute the fast relaxation process (\sim0.17ps) to the coupling of hydroxyl and -ONa groups in the sample

Machine learning classifies predictive kinematic features in a mouse model of neurodegeneration

Motor deficits are observed in Alzheimer’s disease (AD) prior to the appearance of cognitive symptoms. To investigate the role of amyloid proteins in gait disturbances, we characterized locomotion in APP-overexpressing transgenic J20 mice. We used three-dimensional motion capture to characterize quadrupedal locomotion on a treadmill in J20 and wild-type mice. Sixteen J20 mice and fifteen wild-type mice were studied at two ages (4- and 13-month). A random forest (RF) classification algorithm discriminated between the genotypes within each age group using a leave-one-out cross-validation. The balanced accuracy of the RF classification was 92.3 ± 5.2% and 93.3 ± 4.5% as well as False Negative Rate (FNR) of 0.0 ± 0.0% and 0.0 ± 0.0% for the 4-month and 13-month groups, respectively. Feature ranking algorithms identified kinematic features that when considered simultaneously, achieved high genotype classification accuracy. The identified features demonstrated an age-specific kinematic profile of the impact of APP-overexpression. Trunk tilt and unstable hip movement patterns were important in classifying the 4-month J20 mice, whereas patterns of shoulder and iliac crest movement were critical for classifying 13-month J20 mice. Examining multiple kinematic features of gait simultaneously could also be developed to classify motor disorders in humans

Socioeconomic deprivation and mortality in people after ischemic stroke: The China National Stroke Registry

Background: Previous findings of the association between socioeconomic deprivation (SED) and mortality after ischemic stroke are inconsistent. There is a lack of data on the association with combined low education, occupational class and income. We assessed the associations of three indicators with mortality. Methods: We examined data from the China National Stroke Registry, recording all stroke patients occurred between September 2007 and August 2008. Baseline SED was measured using low levels of education at <6 years, occupation as manual laboring and average family income per capita at ≤¥1,000 per month. 12,246 patients with ischemic stroke were analyzed. Results: In a 12-month follow-up 1640 patients died. After adjustment for age, sex, cardiovascular risk factors, severity of stroke and pre-hospital medications, odds ratio (OR) for mortality in patients with low education was 1.25(95%CI 1.05-1.48), manual laboring 1.37(1.09-1.72) and low income 1.19(1.03-1.37). Further adjustment for acute care and medications in and after hospital made no substantial changes in these ORs, except a marginal significant OR for low income (1.15, 0.99-1.33). The OR for low income was 1.27(1.01-1.60) within patients with high education. Compared with no SED, the OR in patients with SED determined by any 1 indicator was 1.33(1.11-1.59), by any 2 indicators 1.36(1.10-1.69) and by all 3 indicators 1.56(1.23- 1.97). Conclusions: There are significant inequalities in survival after ischemic stroke in China in terms of social and material forms of deprivation. General socioeconomic improvement, targeting groups at high risk of mortality is likely to reduce inequality in survival after stroke.The Ministry of Science and Technology of the People’s Republic of China (2006BAI01A11, 2011BAI08B01, 2011BAI08B02, 2012ZX09303-005-001, and 2013BAI09B03), The Beijing Biobank of Cerebral Vascular Disease (D131100005313003), Beijing Institute for Brain Disorders (BIBD-PXM2013_014226_07_000084

Web-based tool for dynamic functional outcome after acute ischemic stroke and comparison with existing models

BACKGROUND: Acute ischemic stroke (AIS) is one of the leading causes of death and adult disability worldwide. In the present study, we aimed to develop a web-based risk model for predicting dynamic functional status at discharge, 3-month, 6-month, and 1-year after acute ischemic stroke (Dynamic Functional Status after Acute Ischemic Stroke, DFS-AIS). METHODS: The DFS-AIS was developed based on the China National Stroke Registry (CNSR), in which eligible patients were randomly divided into derivation (60%) and validation (40%) cohorts. Good functional outcome was defined as modified Rankin Scale (mRS) score ≤ 2 at discharge, 3-month, 6-month, and 1-year after AIS, respectively. Independent predictors of each outcome measure were obtained using multivariable logistic regression. The area under the receiver operating characteristic curve (AUROC) and plot of observed and predicted risk were used to assess model discrimination and calibration. RESULTS: A total of 12,026 patients were included and the median age was 67 (interquartile range: 57–75). The proportion of patients with good functional outcome at discharge, 3-month, 6-month, and 1-year after AIS was 67.9%, 66.5%, 66.9% and 66.9%, respectively. Age, gender, medical history of diabetes mellitus, stroke or transient ischemic attack, current smoking and atrial fibrillation, pre-stroke dependence, pre-stroke statins using, admission National Institutes of Health Stroke Scale score, admission blood glucose were identified as independent predictors of functional outcome at different time points after AIS. The DFS-AIS was developed from sets of predictors of mRS ≤ 2 at different time points following AIS. The DFS-AIS demonstrated good discrimination in the derivation and validation cohorts (AUROC range: 0.837-0.845). Plots of observed versus predicted likelihood showed excellent calibration in the derivation and validation cohorts (all r = 0.99, P < 0.001). When compared to 8 existing models, the DFS-AIS showed significantly better discrimination for good functional outcome and mortality at discharge, 3-month, 6-month, and 1-year after AIS (all P < 0.0001). CONCLUSION: The DFS-AIS is a valid risk model to predict functional outcome at discharge, 3-month, 6-month, and 1-year after AIS. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12883-014-0214-z) contains supplementary material, which is available to authorized users

Abstract Simulation of faceted film growth in three dimensions: microstructure, morphology and texture

We present the results of a series of simulations of the growth of polycrystalline, faceted films in three spatial dimensions. The simulations are based upon the assumptions of the well known van der Drift model in which the growth rate of each surface is fixed only by its crystallographic orientation. The simulation method is based upon the level-set formalism and the only input are the relative velocities of the different facets. We focus specifically on cubic crystals that expose only {111} and {001} facets, such as diamond. Results are presented for the temporal evolution of the surface morphology, microstructure, mean grain size, grain size distribution, and crystallographic texture. The mean grain size and surface roughness increase with film thickness h as h 2/5, in agreement with theoretical results. The grain size distribution is self-similar. The films all exhibit a columnar microstructure and a fiber texture that sharpens as the film grows. The orientation of the texture is determined by the facet growth velocity ratio. The new simulation method is equally applicable to any type of faceted film growth

Discovery of New Inhibitors of Hepatitis C Virus NS3/4A Protease and Its D168A Mutant.

Hepatitis C virus (HCV) is a human pathogen with high morbidity. The HCV NS3/4A protease is essential for viral replication and is one of the top three drug targets. Several drugs targeting the protease have been developed, but drug-resistant mutant strains emerged. Here, we screened a library and synthesized a novel class of small molecules based on a tryptophan derivative scaffold identified as HCV NS3/4A protease inhibitors that are active against both wild type and mutant form of the protease. Only the compounds with predicted binding poses not affected by the most frequent mutations in the active site were selected for experimental validation. The antiviral activities were evaluated by replicon and enzymatic assays. Twenty-two compounds were found to inhibit HCV with EC50 values ranging between 0.64 and 63 μM with compound 22 being the most active. In protease assays, 22 had a comparable inhibition profile for the common mutant HCV GT1b D168A and the wild-type enzyme. However, in the same assay, the potency of the approved drug, simeprevir, decreased 5.7-fold for the mutant enzyme relative to the wild type. The top three inhibitors were also tested against four human serine proteases and were shown to be specific to the viral protease. The fluorescence-based cell viability assay demonstrated a sufficient therapeutic range for the top three candidates

The digital advertising conceptual flow : a literature review

This paper presents a systematic review of the literature of 22 research articles, which used a visualization of the digital advertising conceptual flow with a focus on programmatic advertising. This review aims to address a gap in the literature by identifying a standardization of digital advertising conceptual flow visualization and explanation. Achieving our aims will bring together fragmented literature to serve as a foundation for research into digital advertising conceptual flows and other related research. In our literature review, we have found discrepancies, which imply different understandings of how the advertising exchange between a publisher and an advertiser works. Our work should minimize the risk of wrong conclusions in literature as well as in practice. We therefore recommend a visualization in the field of digital advertising, which should be challenged in future research