528 research outputs found
Spectral triangulation molecular contrast optical coherence tomography with indocyanine green as the contrast agent
We report a new molecular contrast optical coherence tomography (MCOCT) implementation that profiles the contrast agent distribution in a sample by measuring the agent's spectral differential absorption. The method, spectra triangulation MCOCT, can effectively suppress contributions from spectrally dependent scatterings from the sample without a priori knowledge of the scattering properties. We demonstrate molecular imaging with this new MCOCT modality by mapping the distribution of indocyanine green, a FDA-approved infrared red dye, within a stage 54 Xenopus laevis
Protein-based molecular contrast optical coherence tomography with phytochrome as the contrast agent
We report the use of phytochrome A (phyA), a plant protein that can reversibly switch between two states with different absorption maxima (at 660 and 730 nm), as a contrast agent for molecular contrast optical coherence tomography (MCOCT). Our MCOCT scheme builds up a difference image revealing the distribution of phyA within a target sample from pairs of consecutive OCT A-scans acquired at a probe wavelength of 750 nm, both with and without additional illumination of the target sample with 660-nm light. We demonstrate molecular imaging with this new MCOCT modality in a target sample containing a mixture of 0.2% Intralipid and 83 µM of phyA
Protein-based molecular contrast optical coherence tomography
We describe a novel technique for contrast enhancement in optical coherence tomography (OCT) which uses optically switchable protein based chromophores. Photosensitive proteins, such as bacteriorhodopsin and phytochrome, are promising OCT molecular contrast agents by reason of their remarkably low transition activation intensities compatible with in vivo imaging, and their potential for use as genetically expressible markers for molecular imaging. This study details the use of a novel optical switch suppression scheme which uses the absorption change between the two state groups of phytochrome to extract concentration and distribution information of the contrast agent within a target sample
The person-based nature of prejudice: Individual difference predictors of intergroup negativity
Person-based factors influence a range of meaningful life outcomes, including intergroup processes, and have long been implicated in explaining prejudice. In addition to demonstrating significant heritability, person-based factors are evident in expressions of generalised prejudice, a robust finding that some people (relative to others) consistently score higher in prejudice towards multiple outgroups. Our contemporary review includes personality factors, ideological orientations (e.g., authoritarianism), religiosity, anxiety, threat, disgust sensitivity, and cognitive abilities and styles. Meta-analytic syntheses demonstrate that such constructs consistently predict prejudice, often at the upper bounds of effect sizes observed in psychological research. We conclude that prejudice theories need to better integrate person- and situation-based factors, including their interaction, to capture the complexity of prejudice and inform intervention development
The degree of segmental aneuploidy measured by total copy number abnormalities predicts survival and recurrence in superficial gastroesophageal adenocarcinoma
Background: Prognostic biomarkers are needed for superficial gastroesophageal adenocarcinoma (EAC) to predict clinical outcomes and select therapy. Although recurrent mutations have been characterized in EAC, little is known about their clinical and prognostic significance. Aneuploidy is predictive of clinical outcome in many malignancies but has not been evaluated in superficial EAC. Methods: We quantified copy number changes in 41 superficial EAC using Affymetrix SNP 6.0 arrays. We identified recurrent chromosomal gains and losses and calculated the total copy number abnormality (CNA) count for each tumor as a measure of aneuploidy. We correlated CNA count with overall survival and time to first recurrence in univariate and multivariate analyses. Results: Recurrent segmental gains and losses involved multiple genes, including: HER2, EGFR, MET, CDK6, KRAS (recurrent gains); and FHIT, WWOX, CDKN2A/B, SMAD4, RUNX1 (recurrent losses). There was a 40-fold variation in CNA count across all cases. Tumors with the lowest and highest quartile CNA count had significantly better overall survival (p = 0.032) and time to first recurrence (p = 0.010) compared to those with intermediate CNA counts. These associations persisted when controlling for other prognostic variables. Significance: SNP arrays facilitate the assessment of recurrent chromosomal gain and loss and allow high resolution, quantitative assessment of segmental aneuploidy (total CNA count). The non-monotonic association of segmental aneuploidy with survival has been described in other tumors. The degree of aneuploidy is a promising prognostic biomarker in a potentially curable form of EAC. © 2014 Davison et al
Method for Quantitative Study of Airway Functional Microanatomy Using Micro-Optical Coherence Tomography
We demonstrate the use of a high resolution form of optical coherence tomography, termed micro-OCT (μOCT), for investigating the functional microanatomy of airway epithelia. μOCT captures several key parameters governing the function of the airway surface (airway surface liquid depth, periciliary liquid depth, ciliary function including beat frequency, and mucociliary transport rate) from the same series of images and without exogenous particles or labels, enabling non-invasive study of dynamic phenomena. Additionally, the high resolution of μOCT reveals distinguishable phases of the ciliary stroke pattern and glandular extrusion. Images and functional measurements from primary human bronchial epithelial cell cultures and excised tissue are presented and compared with measurements using existing gold standard methods. Active secretion from mucus glands in tissue, a key parameter of epithelial function, was also observed and quantified
Optical coherence tomography—current technology and applications in clinical and biomedical research
Piecing Together the American Voting Puzzle: How Votersâ Personalities and Judgments of Issue Importance Mattered in the 2016 Presidential Election
In the wake of the 2016 election, which surprised pundits and voters on both the left and the right, there has been renewed interest in understanding what predicts American votersâ   choices. In this article, we investigate the roles of personality and issue importance in how people voted in the 2016 U.S. election. In this longitudinal study of 403 MTurk workers who voted in the election, we assessed the relations between personality (openness, social dominance orientation, and national identity importance) and issue importance (group rights and social justice, economic rights, and individual and national rights), and voting for Clinton or Trump. Our results indicate that both individual differences and issue importance as measured in July 2016 predicted votes in November. We also found that the links between personality and voting were mediated by issue importance. Implications for political psychology and the study of personality, campaign issues, and voting behavior are discussed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146841/1/asap12157.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146841/2/asap12157_am.pd
Use of Heart Rate Index to Predict Oxygen Uptake – A Validation Study
International Journal of Exercise Science 13(7): 1705-1717, 2020. An equation that uses heart rate index (HRI) defined as HR/HRrest to predict oxygen uptake (VO2) in METs (e.g., METs = 6 × HRI ‒ 5) has been developed retrospectively from aggregate data of 60 published studies. However, the prediction error of this model as used by an individual has not been established. Therefore, the purpose of this study was to examine the predictive validity of the HRI equation by comparing submaximal and maximal VO2 predicted by the equation (VO2-Pred) with that measured by indirect calorimetry (VO2-Meas). Sixty healthy adults (age 20.5 ± 2.4 yr., body mass 69.4 ± 13.4 kg, height 1.7 ± 0.1 m) underwent a VO2max test and an experimental trial consisting of a 15-min resting measurement and three successive 10-min treadmill exercise bouts performed at 40%, 60% and 80% of VO2max. VO2 and HR were recorded during both the submaximal and maximal exercises and used to obtain VO2-Pred and VO2-Meas for each intensity and for VO2max. Validation was carried out by paired t-test, regression analysis, and Bland-Altman plots. A modest but significant (p \u3c 0.05) correlation was observed between VO2-Meas and VO2-Pred at 40% (r = 0.58), 60% (r = 0.53), and 80% of VO2max (r = 0.56) and at VO2max (r = 0.50). No differences between VO2-Pred and VO2-Meas were found at 40% (5.53 ± 1.21 vs. 5.28 ± 0.98 METs, respectively) of VO2max, but VO2-Pred was higher (p \u3c 0.05) than VO2-Meas at 60% (8.42 ± 1.77 vs. 7.96 ± 1.39 METs, respectively) and 80% (10.79 ± 2.13 vs. 10.29 ± 1.81 METs, respectively) of VO2max. In contrast, VO2-Pred was lower (p \u3c 0.05) than VO2-Meas at VO2max (12.32 ± 2.30 vs. 13.38 ± 2.24 METs, respectively). Standard errors of the estimate were 0.81, 1.20, 1.54, and 1.97 METs at 40%, 60%, 80% of VO2max and at VO2max, respectively. These results suggest that further investigation aimed to establish the accuracy of using HRI to predict VO2 is warranted
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