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

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

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

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

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

New insights into the mechanism of ultrasonic atomization for the production of metal powders in additive manufacturing

Ultrasonic atomization is one of the promising technologies for producing metal powders for additive manufacturing, where precise control of particle size and morphology is essential. In this study, we coupled an ultrasonic transducer with a carbon fiber plate and atomized liquid droplets and films under different vibration amplitudes. Water, glycerol, and pure aluminum melt were used to study the atomization mechanism and the resulting droplet/powder characteristics, respectively. High-speed optical and ultrafast synchrotron X-ray imaging were used to study in situ the ultrasonic atomization dynamics, including pulsation and clustering of cavities inside the liquid layer/films, development of capillary waves, and formation of liquid droplets. For the first time, we observed and captured the occurrence of cavitation during the atomization of resting drops, films and impact droplets. The inertial cavitation events interfered with the capillary waves across the interphase boundary, puncturing and breaking the boundary to produce atomized mist. The in situ observation revealed the intricate dynamics of ultrasonic atomization and underscored the pivotal role of cavitation events throughout the entire atomization process. We also conducted experiments on ultrasonic atomization of liquid aluminum, producing particles of perfectly spherical shape. The particle size tended to decrease with reduced vibration amplitude Our work has demonstrated the important processing strategies on how to tailor the particle size while ensuring consistent particle shape and morphology, which is the key processing capability for producing high quality powders for additive manufacturing applications

Role of maternal diet in the risk of childhood acute leukemia: a systematic review and meta-analysis

Many studies have investigated the etiology of acute leukemia, one of the most common types of cancer in children; however, there is a lack of clarity regarding preventable risk factors. This systematic review and meta-analysis aimed to summarize the current evidence regarding the role of maternal dietary factors in the development of childhood leukemia. All epidemiological studies published until July 2022 that evaluated maternal dietary risk factors for childhood acute leukemia were identified in two electronic databases (PubMed and Web of Science) without limits of publication year or language. A total of 38 studies (1 prospective cohort study, 34 case-control studies and 3 studies with pooled analysis) were included. The published risk estimates were combined into a meta-analysis, using the Generic Inverse Variance method. The maternal consumption of fruits (two or more daily servings vs. less) was inversely associated with acute lymphoblastic leukemia (odds ratio = 0.71; 95% CI, 0.59–0.86), whereas maternal coffee intake (higher than two cups per day vs. no consumption) was associated with an increased risk of acute lymphoblastic leukemia (odds ratio = 1.45; 95% CI, 1.12–1.89). Despite these findings, more high-quality research from cohort studies and the identification of causal factors are needed to develop evidence-based and cost-effective prevention strategies applicable at the population level. Review Registration: PROSPERO registration no. CRD42019128937