Extracellular vesicles (EVs) play important roles in
cell-to-cell
communications and carry high potential as markers targeted in disease
diagnosis, prognosis, and therapeutic development. The main obstacles
to EV study are their high heterogeneity; low amounts present in samples;
and physical similarity to the abundant, interfering matrix components.
Multiple rounds of separation and purification are often needed prior
to EV characterization and function assessment. Herein, we report
the offline coupling of asymmetrical flow field-flow fractionation
(AF4) and capillary electrophoresis (CE) for EV analysis. While AF4
provides gentle and fast EV separation by size, CE resolves EVs from
contaminants with similar sizes but different surface charges. Employing
Western Blotting, ELISA, and SEM, we confirmed that intact EVs were
eluted within a stable time window under the optimal AF4 and CE conditions.
We also proved that EVs could be resolved from free proteins and high-density
lipoproteins by AF4 and be further separated from the low-density
lipoproteins co-eluted in AF4. The effectiveness of the coupled AF4-CE
system in EV analysis was demonstrated by monitoring the changes in
EV secretion from cells and by direct injection of human serum and
detection of serum EVs. We believe that coupling AF4 and CE can provide
rapid EV quantification in biological samples with much reduced matrix
interference and be valuable for the study of total EVs and EV subpopulations
produced by cells or present in clinical samples.
Readers of The Book of Mormon have long identified Christopher Columbus as the “man among the Gentiles” whose divinely prompted journey to the Americas is foretold therein; Columbus thus became a model for the prophetic leadership of Joseph Smith. But if Columbus was inspired to discover the New World, that inspiration was imprecise, as the admiral sailed for China, suggesting that revelation is necessarily an ambiguous, messy process whose conclusions are uncertain and provisional, subject to correction or revision. Because his arrival in the Americas precipitated the genocide of Native peoples, identifying Columbus as a prophetic figure has forced faithful readers of The Book of Mormon to grapple with the question of theodicy. Some, like the novelist Orson Scott Card, have suggested that the Amerindian genocide is compatible with the justice of a loving God, while others have argued that The Book of Mormon celebrates prophetic weakness and promotes hermeneutic humility.
This essay considers the various ways in which writers and visual artists deployed the rattlesnake to advance and, later, destabilize nationalist agendas between the French and Indian War and the Civil War. During the intervening century the rattlesnake, with its powers of fascination, evolved into a multifaceted symbol used to represent a wide range of ideas: British colonial unity; American national identity; white fears of interracial conflict and miscegenation; and the lingering belief that original sin represented a serious threat to a secular republic whose well-being could be ensured only by the virtuous behavior of its citizens. Between 1751 and 1861 visual artists like Benjamin Franklin and Charles Gadsden, together with writers such as J. Hector St. John de Crèvecoeur and Oliver Wendell Holmes, made the rattlesnake a symbol of the national transition from imported art to endogenous culture, from indigenous inhabitants to European emigrants, from innocence to experience.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.