8 research outputs found
Quantitative Determination of the Band Gap of WS<sub>2</sub> with Ambipolar Ionic Liquid-Gated Transistors
We realized ambipolar field-effect transistors by coupling
exfoliated
thin flakes of tungsten disulfide (WS<sub>2</sub>) with an ionic liquid
dielectric. The devices show ideal electrical characteristics, including
very steep subthreshold slopes for both electrons and holes and extremely
low OFF-state currents. Thanks to these ideal characteristics, we
determine with high precision the size of the band gap of WS<sub>2</sub> directly from the gate-voltage dependence of the source-drain current.
Our results demonstrate how a careful use of ionic liquid dielectrics
offers a powerful strategy to study quantitatively the electronic
properties of nanoscale materials
Solid-Phase Flexibility in Ag<sub>2</sub>Se Semiconductor Nanocrystals
Nanocrystals
are known to alter the relative stability of bulk
solid phases. Here we test the limits of this effect on Ag<sub>2</sub>Se nanocrystals, a promising new electronic and infrared material.
In the bulk, Ag<sub>2</sub>Se exhibits a solid–solid phase
transition to a superionic conducting phase at moderate temperatures.
We map this phase transition as a function of size, temperature, and
surface treatment in Ag<sub>2</sub>Se core-only and core–shell
nanocrystals. We show that the transition can be tuned not just below
but also above the bulk phase-transition temperature. This phase flexibility
has implications for applications in optoelectronic and phase-memory
devices
Aerosol-Jet-Printed, 1 Volt H‑Bridge Drive Circuit on Plastic with Integrated Electrochromic Pixel
In this report, we
demonstrate a printed, flexible, and low-voltage
circuit that successfully drives a polymer electrochromic (EC) pixel
as large as 4 mm<sup>2</sup> that is printed on the same substrate.
All of the key components of the drive circuitry, namely, resistors,
capacitors, and transistors, were aerosol-jet-printed onto a plastic
foil; metallic electrodes and interconnects were the only components
prepatterned on the plastic by conventional photolithography. The
large milliampere drive currents necessary to switch a 4 mm<sup>2</sup> EC pixel were controlled by printed electrolyte-gated transistors
(EGTs) that incorporate printable ion gels for the gate insulator
layers and poly(3-hexylthiophene) for the semiconductor channels.
Upon application of a 1 V input pulse, the circuit switches the printed
EC pixel ON (red) and OFF (blue) two times in approximately 4 s. The
performance of the circuit and the behavior of the individual resistors,
capacitors, EGTs, and the EC pixel are analyzed as functions of the
printing parameters and operating conditions
Image_3_Lactobacillus paracasei CNCM I-5220-derived postbiotic protects from the leaky-gut.TIF
The maintenance of intestinal barrier function is essential for preventing different pathologies, such as the leaky gut syndrome (LGS), which is characterized by the passage of harmful agents, like bacteria, toxins, and viruses, into the bloodstream. Intestinal barrier integrity is controlled by several players, including the gut microbiota. Various molecules, called postbiotics, are released during the natural metabolic activity of the microbiota. Postbiotics can regulate host–microbe interactions, epithelial homeostasis, and have overall benefits for our health. In this work, we used in vitro and in vivo systems to demonstrate the role of Lactobacillus paracasei CNCM I-5220-derived postbiotic (LP-PBF) in preserving intestinal barrier integrity. We demonstrated in vitro that LP-PBF restored the morphology of tight junctions (TJs) that were altered upon Salmonella typhimurium exposure. In vivo, LP-PBF protected the gut vascular barrier and blocked S. typhimurium dissemination into the bloodstream. Interestingly, we found that LP-PBF interacts not only with the host cells, but also directly with S. typhimurium blocking its biofilm formation, partially due to the presence of biosurfactants. This study highlights that LP-PBF is beneficial in maintaining gut homeostasis due to the synergistic effect of its different components. These results suggest that LP-PBF could be utilized in managing several pathologies displaying an impaired intestinal barrier function.</p
Image_1_Lactobacillus paracasei CNCM I-5220-derived postbiotic protects from the leaky-gut.TIF
The maintenance of intestinal barrier function is essential for preventing different pathologies, such as the leaky gut syndrome (LGS), which is characterized by the passage of harmful agents, like bacteria, toxins, and viruses, into the bloodstream. Intestinal barrier integrity is controlled by several players, including the gut microbiota. Various molecules, called postbiotics, are released during the natural metabolic activity of the microbiota. Postbiotics can regulate host–microbe interactions, epithelial homeostasis, and have overall benefits for our health. In this work, we used in vitro and in vivo systems to demonstrate the role of Lactobacillus paracasei CNCM I-5220-derived postbiotic (LP-PBF) in preserving intestinal barrier integrity. We demonstrated in vitro that LP-PBF restored the morphology of tight junctions (TJs) that were altered upon Salmonella typhimurium exposure. In vivo, LP-PBF protected the gut vascular barrier and blocked S. typhimurium dissemination into the bloodstream. Interestingly, we found that LP-PBF interacts not only with the host cells, but also directly with S. typhimurium blocking its biofilm formation, partially due to the presence of biosurfactants. This study highlights that LP-PBF is beneficial in maintaining gut homeostasis due to the synergistic effect of its different components. These results suggest that LP-PBF could be utilized in managing several pathologies displaying an impaired intestinal barrier function.</p
Image_4_Lactobacillus paracasei CNCM I-5220-derived postbiotic protects from the leaky-gut.TIF
The maintenance of intestinal barrier function is essential for preventing different pathologies, such as the leaky gut syndrome (LGS), which is characterized by the passage of harmful agents, like bacteria, toxins, and viruses, into the bloodstream. Intestinal barrier integrity is controlled by several players, including the gut microbiota. Various molecules, called postbiotics, are released during the natural metabolic activity of the microbiota. Postbiotics can regulate host–microbe interactions, epithelial homeostasis, and have overall benefits for our health. In this work, we used in vitro and in vivo systems to demonstrate the role of Lactobacillus paracasei CNCM I-5220-derived postbiotic (LP-PBF) in preserving intestinal barrier integrity. We demonstrated in vitro that LP-PBF restored the morphology of tight junctions (TJs) that were altered upon Salmonella typhimurium exposure. In vivo, LP-PBF protected the gut vascular barrier and blocked S. typhimurium dissemination into the bloodstream. Interestingly, we found that LP-PBF interacts not only with the host cells, but also directly with S. typhimurium blocking its biofilm formation, partially due to the presence of biosurfactants. This study highlights that LP-PBF is beneficial in maintaining gut homeostasis due to the synergistic effect of its different components. These results suggest that LP-PBF could be utilized in managing several pathologies displaying an impaired intestinal barrier function.</p
Image_2_Lactobacillus paracasei CNCM I-5220-derived postbiotic protects from the leaky-gut.TIF
The maintenance of intestinal barrier function is essential for preventing different pathologies, such as the leaky gut syndrome (LGS), which is characterized by the passage of harmful agents, like bacteria, toxins, and viruses, into the bloodstream. Intestinal barrier integrity is controlled by several players, including the gut microbiota. Various molecules, called postbiotics, are released during the natural metabolic activity of the microbiota. Postbiotics can regulate host–microbe interactions, epithelial homeostasis, and have overall benefits for our health. In this work, we used in vitro and in vivo systems to demonstrate the role of Lactobacillus paracasei CNCM I-5220-derived postbiotic (LP-PBF) in preserving intestinal barrier integrity. We demonstrated in vitro that LP-PBF restored the morphology of tight junctions (TJs) that were altered upon Salmonella typhimurium exposure. In vivo, LP-PBF protected the gut vascular barrier and blocked S. typhimurium dissemination into the bloodstream. Interestingly, we found that LP-PBF interacts not only with the host cells, but also directly with S. typhimurium blocking its biofilm formation, partially due to the presence of biosurfactants. This study highlights that LP-PBF is beneficial in maintaining gut homeostasis due to the synergistic effect of its different components. These results suggest that LP-PBF could be utilized in managing several pathologies displaying an impaired intestinal barrier function.</p
Photocatalytic Water-Splitting Enhancement by Sub-Bandgap Photon Harvesting
Upconversion
is a photon-management process especially suited to water-splitting
cells that exploit wide-bandgap photocatalysts. Currently, such catalysts
cannot utilize 95% of the available solar photons. We demonstrate
here that the energy-conversion yield for a standard photocatalytic
water-splitting device can be enhanced under solar irradiance by using
a low-power upconversion system that recovers part of the unutilized
incident sub-bandgap photons. The upconverter is based on a sensitized
triplet–triplet annihilation mechanism (sTTA-UC) obtained in
a dye-doped elastomer and boosted by a fluorescent nanocrystal/polymer
composite that allows for broadband light harvesting. The complementary
and tailored optical properties of these materials enable efficient
upconversion at subsolar irradiance, allowing the realization of the
first prototype water-splitting cell assisted by solid-state upconversion.
In our proof-of concept device the increase of the performance is
3.5%, which grows to 6.3% if concentrated sunlight (10 sun) is used.
Our experiments show how the sTTA-UC materials can be successfully
implemented in technologically relevant devices while matching the
strict requirements of clean-energy production