966 research outputs found
Human Extracellular-Matrix Functionalization of 3D hiPSC-Based Cardiac Tissues Improves Cardiomyocyte Maturation
The work here presented was funded by Fundacao para a Ciencia e Tecnologia (FCT) projects NETDIAMOND (SAICTPAC/0047/2015), financially supported by FEEI-Lisboa2020 and FCT/POCI-01-0145-FEDER-016385, and MetaCardio (PTDC/BTM-SAL/32566/2017); iNOVA4-Health -UIDB/04462/2020 and UIDP/04462/2020, a program financially supported by FCT/Ministerio da Ciencia, Tecnologia e Ensino Superior, through national funds is acknowledged; Funding from INTERFACE Programme, through the Innovation, Technology and Circular Economy Fund (FITEC), is gratefully acknowledged; and EU-funded projects BRAV3 (H2020, ID:874827) and ERAatUC (ref. 669088). HVA, AFL, and DS were financed by FCT Grants SFRH/BPD/120595/2016 and PD/BD/139078/2018 and PD/BD/106051/2015, respectively.Human induced pluripotent stem cells (hiPSC) possess significant therapeutic potential due to their high self-renewal capability and potential to differentiate into specialized cells such as cardiomyocytes. However, generated hiPSC-derived cardiomyocytes (hiPSC-CM) are still immature, with phenotypic and functional features resembling the fetal rather than their adult counterparts, which limits their application in cell-based therapies, in vitro cardiac disease modeling, and drug cardiotoxicity screening. Recent discoveries have demonstrated the potential of the extracellular matrix (ECM) as a critical regulator in development, homeostasis, and injury of the cardiac microenvironment. Within this context, this work aimed to assess the impact of human cardiac ECM in the phenotype and maturation features of hiPSC-CM. Human ECM was isolated from myocardium tissue through a physical decellularization approach. The cardiac tissue decellularization process reduced DNA content significantly while maintaining ECM composition in terms of sulfated glycosaminoglycans (s-GAG) and collagen content. These ECM particles were successfully incorporated in three-dimensional (3D) hiPSC-CM aggregates (CM+ECM) with no impact on viability and metabolic activity throughout 20 days in 3D culture conditions. Also, CM+ECM aggregates displayed organized and longer sarcomeres, with improved calcium handling when compared to hiPSC-CM aggregates. This study shows that human cardiac ECM functionalization of hiPSC-based cardiac tissues improves cardiomyocyte maturation. The knowledge generated herein provides essential insights to streamline the application of ECM in the development of hiPSC-based therapies targeting cardiac diseases.publishersversionpublishe
Engineering squeezed states in high-Q cavities
While it has been possible to build fields in high-Q cavities with a high
degree of squeezing for some years, the engineering of arbitrary squeezed
states in these cavities has only recently been addressed [Phys. Rev. A 68,
061801(R) (2003)]. The present work examines the question of how to squeeze any
given cavity-field state and, particularly, how to generate the squeezed
displaced number state and the squeezed macroscopic quantum superposition in a
high-Q cavity
Proposal to produce long-lived mesoscopic superpositions through an atom-driven field interaction
We present a proposal for the production of longer-lived mesoscopic
superpositions which relies on two requirements: parametric amplification and
squeezed vacuum reservoir for cavity-field states. Our proposal involves the
interaction of a two-level atom with a cavity field which is simultaneously
subjected to amplification processes.Comment: 12 pages, title changed, text improved and refences adde
Engineering arbitrary motional ionic state through realistic intensity-fluctuating laser pulses
We present a reliable scheme for engineering arbitrary motional ionic states
through an adaptation of the projection synthesis technique for trapped-ion
phenomena. Starting from a prepared coherent motional state, the Wigner
function of the desired state is thus sculpted from a Gaussian distribution.
The engineering process has also been developed to take into account the errors
arising from intensity fluctuations in the exciting-laser pulses required for
manipulating the electronic and vibrational states of the trapped ion. To this
end, a recently developed phenomenological-operator approach that allows for
the influence of noise will be applied. This approach furnishes a
straightforward technique to estimate the fidelity of the prepared state in the
presence of errors, precluding the usual extensive ab initio calculations. The
results obtained here by the phenomenological approach, to account for the
effects of noise in our engineering scheme, can be directly applied to any
other process involving trapped-ion phenomena.Comment: more information at http://www.df.ufscar.br/~quantum
Preparation and control of a cavity-field state through atom-driven field interaction: towards long-lived mesoscopic states
The preparation of mesoscopic states of the radiation and matter fields
through atom-field interactions has been achieved in recent years and employed
for a range of striking applications in quantum optics. Here we present a
technique for the preparation and control of a cavity mode which, besides
interacting with a two-level atom, is simultaneously submitted to linear and
parametric amplification processes. The role of the amplification-controlling
fields in the achievement of real mesoscopic states, is to produce
highly-squeezed field states and, consequently, to increase both: i) the
distance in phase space between the components of the prepared superpositions
and ii) the mean photon number of such superpositions. When submitting the
squeezed superposition states to the action of similarly squeezed reservoirs,
we demonstrate that under specific conditions the decoherence time of the
states becomes independent of both the distance in phase space between their
components and their mean photon number. An explanation is presented to support
this remarkable result, together with a discussion on the experimental
implementation of our proposal. We also show how to produce number states with
fidelities higher than those derived as circular states
Selection of carbohydrate-active probiotics from the gut of carnivorous fish fed plant-based diets
Abstract The gastrointestinal microbiota plays a critical role on host health and metabolism. This is particularly important in teleost nutrition, because fish do not possess some of the necessary enzymes to cope with the dietary challenges of aquaculture production. A main difficulty within fish nutrition is its dependence on fish meal, an unsustainable commodity and a source of organic pollutants. The most obvious sustainable alternatives to fish meal are plant feedstuffs, but their nutritive value is limited by the presence of high levels of non-starch polysaccharides (NSP), which are not metabolized by fish. The composition of fish-gut microbial communities have been demonstrated to adapt when the host is fed different ingredients. Thus, we hypothesized that a selective pressure of plant-based diets on fish gut microbiota, could be a beneficial strategy for an enrichment of bacteria with a secretome able to mobilize dietary NSP. By targeting bacterial sporulating isolates with diverse carbohydrase activities from the gut of European sea bass, we have obtained isolates with high probiotic potential. By inferring the adaptive fitness to the fish gut and the amenability to industrial processing, we identified the best two candidates to become industrially valuable probiotics. This potential was confirmed in vivo, since one of the select isolates lead to a better growth and feed utilization efficiency in fish fed probiotic-supplemented plant-based diets, thus contributing for sustainable and more cost-effective aquaculture practices
Insights into the Lignocellulose-Degrading Enzyme System of Humicola grisea var. thermoidea Based on Genome and Transcriptome Analysis.
Abstract: Humicola grisea var. thermoidea is a thermophilic ascomycete and important enzyme producer that has an efficient enzymatic system with a broad spectrum of thermostable carbohydrate-active (CAZy) enzymes. These enzymes can be employed in lignocellulose biomass deconstruction and other industrial applications. In this work, the genome of H. grisea var. thermoidea was sequenced. The acquired sequence reads were assembled into a total length of 28.75 Mbp. Genome features correlate with what was expected for thermophilic Sordariomycetes. The transcriptomic data showed that sugar-cane bagasse significantly upregulated genes related to primary metabolism and polysaccharide deconstruction, especially hydrolases, at both pH 5 and pH 8. However, a number of exclusive and shared genes between the pH values were found, especially at pH 8. H. grisea expresses an average of 211 CAZy enzymes (CAZymes), which are capable of acting in different substrates. The top upregulated genes at both pH values represent CAZyme-encoding genes from different classes, including acetylxylan esterase, endo-1,4-b-mannosidase, exoglucanase, and endoglucanase genes. For the first time, the arsenal that the thermophilic fungus H. grisea var. thermoidea possesses to degrade the lignocellulosic biomass is shown. Carbon source and pH are of pivotal importance in regulating gene expression in this organism, and alkaline pH is a key regulatory factor for sugarcane bagasse hydrolysis. This work paves the way for the genetic manipulation and robust biotechnological applications of this fungus
Decoherence in trapped ions due to polarization of the residual background gas
We investigate the mechanism of damping and heating of trapped ions
associated with the polarization of the residual background gas induced by the
oscillating ions themselves. Reasoning by analogy with the physics of surface
electrons in liquid helium, we demonstrate that the decay of Rabi oscillations
observed in experiments on 9Be+ can be attributed to the polarization phenomena
investigated here. The measured sensitivity of the damping of Rabi oscillations
with respect to the vibrational quantum number of a trapped ion is also
predicted in our polarization model.Comment: 26 pdf pages with 5 figures, http://www.df.ufscar.br/~quantum
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