Resistive-Pulse Sensing Coupled with Fluorescence Lifetime Imaging Microscopy for Differentiation of Individual Liposomes.

Characterization of individual biological nanoparticles can be significantly improved by coupling complementary analytical methods. Here, we combine resistive-pulse sensing (RPS) with fluorescence lifetime imaging microscopy (FLIM) to differentiate liposomes at the single-particle level. RPS measures the particle volume, shape, and surface-charge density, and FLIM determines the fluorescence lifetime of the fluorophore associated with the lipid membrane.

Advancements and Applications of Conjugated Polyelectrolytes and Conjugated Oligoelectrolytes in Bioanalytical and Electrochemical Contexts.

In the past decade, conjugated oligoelectrolytes (COEs) and conjugated polyelectrolytes (CPEs) have emerged at the forefront of active materials in bioanalytical and electrochemical settings due to their unique electronic and ionic properties. These materials possess π-conjugated backbones with ionic functionalities at the ends of their side chains, granting them water solubility and facilitating their processability, exploration, and applications in aqueous environments. In this perspective, the basis for evaluating their figures of merit in selected bioanalytical and electrochemical contexts will be provided and contextualized.

Evolving Synergy Between Synthetic and Biotic Elements in Conjugated Polyelectrolyte/Bacteria Composite Improves Charge Transport and Mechanical Properties.

gLiving materials can achieve unprecedented function by combining synthetic materials with the wide range of cellular functions. Of interest are situations where the critical properties of individual abiotic and biotic elements improve via their combination. For example, integrating electroactive bacteria into conjugated polyelectrolyte (CPE) hydrogels increases biocurrent production.

Sensing cholesterol-induced rigidity in model membranes with time-resolved fluorescence spectroscopy and microscopy.

Here, we report the characterization of cholesterol levels on membrane fluidity with a twisted intramolecular charge transfer (TICT) membrane dye, namely DI-8-ANEPPS, using fluorescence lifetime techniques such as time-correlated single photon counting (TCSPC) and fluorescence lifetime imaging microscopy (FLIM). The characterized liposomes comprised a 3 : 1 ratio of POPC and POPG, respectively, 1% DI-8-ANEPPS, and increasing cholesterol levels from 0% to 50%. Fluorescence lifetime characterization revealed that increasing the cholesterol levels from 0% to 50% increases the fluorescence lifetime of DI-8-ANEPPS from 2.

Recyclable Conjugated Polyelectrolyte Hydrogels for Pseudocapacitor Fabrication.

In alignment with widespread interest in carbon neutralization and sustainable practices, we disclose that conjugated polyelectrolyte (CPE) hydrogels are a type of recyclable, electrochemically stable, and environmentally friendly pseudocapacitive material for energy storage applications. By leveraging ionic-electronic coupling in a relatively fluid medium, one finds that hydrogels prepared using a fresh batch of an anionic CPE, namely, Pris-CPE-K, exhibit a specific capacitance of 32.6 ± 6.

An n-Type Conjugated Oligoelectrolyte Mimics Transmembrane Electron Transport Proteins for Enhanced Microbial Electrosynthesis.

Interfacing bacteria as biocatalysts with an electrode provides the basis for emerging bioelectrochemical systems that enable sustainable energy interconversion between electrical and chemical energy. Electron transfer rates at the abiotic-biotic interface are, however, often limited by poor electrical contacts and the intrinsically insulating cell membranes. Herein, we report the first example of an n-type redox-active conjugated oligoelectrolyte, namely COE-NDI, which spontaneously intercalates into cell membranes and mimics the function of endogenous transmembrane electron transport proteins.

Hybrid Organic-Inorganic Perovskite Superstructures for Ultrapure Green Emissions.

All inorganic CsPbBr superstructures (SSs) have attracted much research interest due to their unique photophysical properties, such as their large emission red-shifts and super-radiant burst emissions. These properties are of particular interest in displays, lasers and photodetectors. Currently, the best-performing perovskite optoelectronic devices incorporate organic cations (methylammonium (MA), formamidinium (FA)), however, hybrid organic-inorganic perovskite SSs have not yet been investigated.

Water-soluble extracellular vesicle probes based on conjugated oligoelectrolytes.

We developed a series of transmembrane conjugated oligoelectrolytes (COEs) with tunable optical emissions from the UV to the near IR to address the false-positive problem when detecting nanometer-sized extracellular vesicles (EVs) by flow cytometry. The amphiphilic molecular framework of COEs is defined by a linear conjugated structure and cationic charged groups at each terminal site. Consequently, COEs have excellent water solubility and the absence of nanoaggregates at concentrations up to 50 μM, and unbound COE dyes can be readily removed through ultrafiltration.

Enabling Electron Injection for Microbial Electrosynthesis with n-Type Conjugated Polyelectrolytes.

Microbial electrosynthesis-using renewable electricity to stimulate microbial metabolism-holds the promise of sustainable chemical production. A key limitation hindering performance is slow electron-transfer rates at biotic-abiotic interfaces. Here a new n-type conjugated polyelectrolyte is rationally designed and synthesized and its use is demonstrated as a soft conductive material to encapsulate electroactive bacteria Shewanella oneidensis MR-1.

Conjugated Oligoelectrolytes for Long-Term Tumor Tracking with Incremental NIR-II Emission.

The design and synthesis of the near-infrared (NIR)-II emissive conjugated oligoelectrolyte COE-BBT are reported. COE-BBT has a solubility in aqueous media greater than 50 mg mL , low toxicity, and a propensity to intercalate lipid bilayers, wherein it exhibits a higher emission quantum yield relative to aqueous media. Addition of COE-BBT to cells provides two emission channels, at ≈500 and ≈1020 nm, depending on the excitation wavelength, which facilitates in vitro confocal microscopy and in vivo animal imaging.

Conjugated Polyelectrolyte/Bacteria Living Composites in Carbon Paper for Biocurrent Generation.

Successful practical implementation of bioelectrochemical systems (BES) requires developing affordable electrode structures that promote efficient electrical communication with microbes. Recent efforts have centered on immobilizing bacteria with organic semiconducting polymers on electrodes via electrochemical methods. This approach creates a fixed biocomposite that takes advantage of the increased electrode's electroactive surface area (EASA).

New Direct Approach for Determining the Reverse Intersystem Crossing Rate in Organic Thermally Activated Delayed Fluorescent (TADF) Emitters.

We developed a new optical method to determine the rate of reverse intersystem crossing () in thermally activated delayed fluorescent (TADF) organic chromophores using time-resolved transient absorption spectroscopy. We successfully correlated the of the TADF-chromophores with device performance. Specifically, we focused on the external quantum efficiency (η) and the stability of the device at high brightness levels.

Comparative Quantification of Trail-Following Behavior in Pest Ants.

A comparison of trail-following movement parameters of six major urban pest ants, (Forel) (Hymenoptera: Formicidae), , (Mayr), Buren, (Forel), and (Smith) demonstrated several differences in velocity of movement, amplitude of the deviations from a marked trail, percent fidelity to the trail, number of curves per unit of trail, and trail-following accuracy. and had the largest deviations from the marked trails and moved three times faster (25-30 mm/s) along the trail than the slowest ant, (< 10 mm/s), with other ants following between these extremes. Species differences in relation to going toward or returning from food were observed in a few cases, especially with for which velocity, amplitude, and trail fidelity differed between the foraging and return trails.

Enacting Two-Electron Transfer from a Double-Triplet State of Intramolecular Singlet Fission.

A simulation-led strategy enacts two-electron transfer between an intramolecular singlet fission chromophore (tetracyanomethylene quinoidal bithiopehene with β,β'-solubilizing groups) and multielectron acceptor (anthraquinone). The thermodynamic plausibility of multielectron transfer from a double-triplet state and the absorption spectra of electron transfer (ET) products were predicted using quantum chemical simulations. These predictions are consistent with experimental observations of reduced lifetimes in time-resolved fluorescence spectroscopy, changes in transmission profile, and appearance of new absorption bands in transient absorption spectroscopy, all of which support multi-ET in the QOT2/AQ mixture.

[Aortic root homograft in the surgical treatment of aortic valve disease with dilated ascending aorta].

Introduction And Objectives: Patients with aortic valve disease and a dilated ascending aorta are usually treated with a composite graft comprising a valve and conduit. We review here the results of treatment with an aortic root homograft as a valid alternative.

Patients And Method: Twenty-two consecutive patients with a mean age of 64.